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Sample records for pressure-controlled ventilation pcv

  1. Liver dysfunction after lung recruitment manoeuvres during pressure-controlled ventilation in experimental acute respiratory distress

    PubMed Central

    Kredel, Markus; Muellenbach, Ralf M; Brock, Robert W; Wilckens, Hans-Hinrich; Brederlau, Joerg; Roewer, Norbert; Wunder, Christian

    2007-01-01

    Introduction Consequences of lung recruitment with prolonged high positive end-expiratory pressure (PEEP) ventilation for liver function are unclear. We therefore investigated liver dysfunction during two different ventilation treatment regimens of experimental acute respiratory distress syndrome. Methods Sixteen anaesthetised juvenile pietrain pigs were ventilated in the pressure-controlled mode (PCV) with an inspiratory fraction of oxygen (FiO2) of 1.0, a respiratory frequency of 30 per minute, a tidal volume of 6 ml/kg, and a PEEP of 5 cm H2O. After lung injury was induced by repeated pulmonary lavage with normal saline, animals were randomly assigned into two groups (n = 8 each) for a 24-hour trial: PCV (unchanged ventilation) and PCV with recruitment (PCV+R) (starting with a sustained inflation of 50 cm H2O for 1 minute, the ventilation was continued while increasing PEEP in increments of 3 cm H2O every 15 minutes as long as arterial oxygen tension [PaO2] improved). After recruitment, FiO2 was reduced to 0.4 and the PEEP was lowered every 15 minutes until PaO2 decreased to 12.0 to 14.7 kPa (90 to 110 torr). Serum levels of hyaluronic acid (HA), routine liver serum markers, and plasma disappearance rate of indocyanine green (ICG) were tested before and after lung injury, and 6 and 18 hours after randomisation. Liver serum markers were also tested at 24 hours. Paraffin sections of liver tissue stained by haematoxylin and eosin were made after euthanisation. Results The PCV+R group exhibited more polymorphonuclear neutrophils and lymphocytes in the liver sinusoids: median score (interquartile range) of 1.5 (1.4 to 1.5) compared to 0.9 (0.7 to 1.1) (p = 0.01). Elevation of bilirubin, aspartate aminotransferase, and lactate dehydrogenase was more prominent in the PCV+R group. Plasma disappearance rate of ICG indicated no liver dysfunction. HA levels in the PCV+R group gradually increased and were significantly higher (p < 0.001) at 6 and 18 hours with 59 (57 to 64) and 75 (66 to 84) ng/ml, respectively, than in the PCV group with 34 (32 to 48) and 41 (38 to 42) ng/ml, respectively. Conclusion The PCV+R group showed a more prominent inflammatory reaction in their liver sinusoids accompanied by increased serum levels of liver enzymes and HA. Therefore, recruitment with higher PEEP levels for treatment of respiratory failure might lead to liver dysfunction. PMID:17261192

  2. Assisted pressure control ventilation via a mini-tracheostomy tube for postoperative respiratory management of lung cancer patients.

    PubMed

    Nomori, H; Horio, H; Suemasu, K

    2000-03-01

    Assisted pressure control ventilation (PCV) via a min-tracheostomy tube (MTT) was conducted to improve gas exchange and reduce the work of breathing of lung cancer patients after surgery. Thirty-two patients with lung cancer underwent lobectomy and were managed postoperatively by assisted PCV via an MTT. On the basis of a simulation study using a lung model for clinical use, we set the inspiratory pressure to 20 cmH2O and inspiratory time to 1.0 sec to produce a 450-ml supported volume via the MTT per breath. The blood gases and respiratory rate of each patient were measured under three sets of conditions: PCV via an MTT transtracheal oxygenation (TTO) via an MTT and a Venturi face mask with the same FiO2. After PCV via an MTT overnight, the blood gases in the room air were measured 2.5 h after withdrawing PCV. In order to determine the effect of PCV via an MTT on gas exchange after PCV withdrawal, 32 other age and sex-matched lung cancer patients, who had undergone lobectomy and oxygenation via a face mask alone after surgery, were used as historical controls. The simulation study showed that the ventilated volume provided by assisted PCV via an MTT was about half that provided via a conventional endotracheal tube, even in the presence of air leakage. The clinical application showed that the ventilated volume obtained with the PCV via an MTT was significantly higher than that with spontaneous breathing (P<0.001). PCV via an MTT increased the PaO2 and reduced both the PaCO2 and respiratory rate significantly in comparison with TTO via an MTT and a face mask (P<0.001). After PCV withdrawal the morning after surgery, the PaO2 of the PCV group was significantly higher than that of the historical controls (P<0.001). No postoperative pulmonary complications were observed in either the PCV or the control groups, however. In addition, no complications or morbidity were seen related to either MTT insertion or PCV via an MTT. Assisted PVC via an MTT increased the tidal volume, improved the gas exchange, reduced the respiratory rate by providing adequate ventilatory support and increased the PaO2, even after withdrawal following lung surgery. Even though we did not observe any benefit of clinical outcome with PCV via an MTT in the present study, this procedure appears to be a potentially useful respiratory management modality for patients with high risk of postoperative pulmonary complications. PMID:10783931

  3. Ventilation during laparoscopic-assisted bariatric surgery: volume-controlled, pressure-controlled or volume-guaranteed pressure-regulated modes

    PubMed Central

    Dion, Joanna M; McKee, Chris; Tobias, Joseph D; Sohner, Paul; Herz, Daniel; Teich, Steven; Rice, Julie; Barry, N’ diris; Michalsky, Marc

    2014-01-01

    Introduction: Managing ventilation and oxygenation during laparoscopic procedures in severely obese patients undergoing weight loss surgery presents many challenges. Pressure-controlled ventilation, volume-guaranteed (PCV-VG) is a dual-control mode of ventilation and an alternative to pressure (PC) or volume (VC) controlled ventilation. PCV-VG features a user-selected tidal volume target, that is auto-regulated and pressure controlled. We hypothesized that PCV-VG ventilation would provide improved oxygenation and ventilation during laparoscopic bariatric surgery with a lower peak inflating pressure (PIP) than either PC or VC ventilation. Methods: This was a prospective cross-over cohort trial (n = 20). In random sequence each patient received the three modes of ventilation for 20 minutes during the laparoscopic portion of the procedure. For all modes of ventilation the goal tidal volume was 6-8 mL/kg, and the respiratory rate was adjusted to achieve normocarbia. The PIP, exhaled tidal volume, respiratory rate, and oxygen saturation were recorded every five minutes. At the end of 20 minutes, an arterial blood gas was obtained. Data were analyzed using a paired t-test. Results: PCV-VG and PC ventilation both resulted in significantly lower PIP (cmH2O) than VC ventilation (30.5 ± 3.0, 31.6 ± 4.9, and 36.3 ± 3.4 mmHg respectively; p < 0.01 for PCV-VG vs. VC and PC vs. VC). There was no difference in oxygenation (PaO2), ventilation (PaCO2) or hemodynamic variables between the three ventilation modes. Conclusions: In adolescents and young adults undergoing laparoscopic bariatric surgery, PCV-VG and PC were superior to VC ventilation in their ability to provide ventilation with the lowest PIP. PMID:25232415

  4. Pressure Controlled Ventilation to Induce Acute Lung Injury in Mice

    PubMed Central

    Koeppen, Michael; Eckle, Tobias; Eltzschig, Holger K.

    2011-01-01

    Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged mechanical ventilation, contributes to morbidity and mortality of critical illness, and studies on novel genetic or pharmacological targets are areas of intense investigation (1-3, 5, 8, 26, 30, 33-36). ALI is defined by the acute onset of the disease, which leads to non-cardiac pulmonary edema and subsequent impairment of pulmonary gas exchange (36). We have developed a murine model of ALI by using a pressure-controlled ventilation to induce ventilator-induced lung injury (2). For this purpose, C57BL/6 mice are anesthetized and a tracheotomy is performed followed by induction of ALI via mechanical ventilation. Mice are ventilated in a pressure-controlled setting with an inspiratory peak pressure of 45 mbar over 1 - 3 hours. As outcome parameters, pulmonary edema (wet-to-dry ratio), bronchoalveolar fluid albumin content, bronchoalveolar fluid and pulmonary tissue myeloperoxidase content and pulmonary gas exchange are assessed (2). Using this technique we could show that it sufficiently induces acute lung inflammation and can distinguish between different treatment groups or genotypes (1-3, 5). Therefore this technique may be helpful for researchers who pursue molecular mechanisms involved in ALI using a genetic approach in mice with gene-targeted deletion. PMID:21587159

  5. Advanced pressure control modes of ventilation in cardiac surgery: Scanty evidence or unexplored terrain?

    PubMed Central

    Parida, Satyen; Bidkar, Prasanna Udupi

    2016-01-01

    Lung atelectasis resulting after cardiopulmonary bypass (CPB) can result in increased intrapulmonary shunting and consequent hypoxemia. Advanced pressure control modes of ventilation might have at least a theoretical advantage over conventional modes by assuring a minimum target tidal volume delivery at reasonable pressures, thus having potential advantages while ventilating patients with pulmonary atelectasis postcardiac surgery. However, the utility of these modes in the post-CPB setting have not been widely investigated, and their role in cardiac intensive care, therefore, remains quite limited. PMID:27076729

  6. Comparison of three ventilatory modes during one-lung ventilation in elderly patients

    PubMed Central

    Lin, Fei; Pan, Linghui; Qian, Wei; Ge, Wanyun; Dai, Huijun; Liang, Yubing

    2015-01-01

    Objective: The purpose of this study was to explore the effects of three different ventilatory modes: volume controlled ventilation (VCV), pressure controlled ventilation (PCV) and pressure controlled ventilation-volume guaranteed (PCV-VG) on arterial oxygenation and airway pressure during one-lung ventilation (OLV) in elderly patients. Methods: We enrolled 66 patients who underwent thoracic surgery requiring at least 1 hour of OLV and aged above 65 years into the study. Patients were classified into VCV, PCV and PCV-VG groups according to a controlled, randomized design. Patients were ventilated to obtain a tidal volume (TV) of 8 mL/kg with three different ventilatory modes during OLV. The Hemodynamic and respiratory data had been recorded during intraoperation and arterial blood gases were obtained at baseline, 20, 40, 60 minutes after OLV, end of surgery. Results: Compared with VCV group, Ppeak was significantly lower in PCV and PCV-VG group (P<0.05), and the difference was not found between the PCV and PCV-VG group. PaO2 in PCV and PCV-VG group were higher than VCV group after the point of OLV+40 (P<0.05). Comparison of PCV group, PaO2 in PCV-VG group was higher, but did not show a significantly improved during OLV (P>0.05). Conclusions: Compared with VCV, the use of PCV and PCV-VG have a significant advantage in intraoperative oxygenation and airway pressure for eldly patients undergoing OLV. PMID:26309682

  7. Continuous endotracheal tube cuff pressure control system protects against ventilator-associated pneumonia

    PubMed Central

    2014-01-01

    Introduction The use of a system for continuous control of endotracheal tube cuff pressure reduced the incidence of ventilator-associated pneumonia (VAP) in one randomized controlled trial (RCT) with 112 patients but not in another RCT with 142 patients. In several guidelines on the prevention of VAP, the use of a system for continuous or intermittent control of endotracheal cuff pressure is not reviewed. The objective of this study was to compare the incidence of VAP in a large sample of patients (n = 284) treated with either continuous or intermittent control of endotracheal tube cuff pressure. Methods We performed a prospective observational study of patients undergoing mechanical ventilation during more than 48 hours in an intensive care unit (ICU) using either continuous or intermittent endotracheal tube cuff pressure control. Multivariate logistic regression analysis (MLRA) and Cox proportional hazard regression analysis were used to predict VAP. The magnitude of the effect was expressed as odds ratio (OR) or hazard ratio (HR), respectively, and 95% confidence interval (CI). Results We found a lower incidence of VAP with the continuous (n = 150) than with the intermittent (n = 134) pressure control system (22.0% versus 11.2%; p = 0.02). MLRA showed that the continuous pressure control system (OR = 0.45; 95% CI = 0.22-0.89; p = 0.02) and the use of an endotracheal tube incorporating a lumen for subglottic secretion drainage (SSD) (OR = 0.39; 95% CI = 0.19-0.84; p = 0.02) were protective factors against VAP. Cox regression analysis showed that the continuous pressure control system (HR = 0.45; 95% CI = 0.24-0.84; p = 0.01) and the use of an endotracheal tube incorporating a lumen for SSD (HR = 0.29; 95% CI = 0.15-0.56; p < 0.001) were protective factors against VAP. However, the interaction between type of endotracheal cuff pressure control system (continuous or intermittent) and endotracheal tube (with or without SSD) was not statistically significant in MLRA (OR = 0.41; 95% CI = 0.07-2.37; p = 0.32) or in Cox analysis (HR = 0.35; 95% CI = 0.06-1.84; p = 0.21). Conclusions The use of a continuous endotracheal cuff pressure control system and/or an endotracheal tube with a lumen for SSD could help to prevent VAP in patients requiring more than 48 hours of mechanical ventilation. PMID:24751286

  8. Effects of assisted ventilation on the work of breathing: volume-controlled versus pressure-controlled ventilation.

    PubMed

    Cinnella, G; Conti, G; Lofaso, F; Lorino, H; Harf, A; Lemaire, F; Brochard, L

    1996-03-01

    During assisted ventilation, the same tidal volume can be delivered in different ways, with the possibility for the physician to vary the ventilatory target (pressure or volume) and the peak flow setting. We compared the effects on the respiratory work rate of assisted ventilation, delivered either with a square wave flow pattern (assist control ventilation [ACV]) or with a decelerating flow pattern and a constant pressure (assisted pressure-control ventilation [APCV]). In the first part of the study where seven patients were studied, inspiratory time and tidal volume were similar in the two modes of ventilation. High and moderate levels of tidal volume (VT) were studied (12 ml/kg and 8 ml/kg, respectively). To obtain moderate VT, inspiratory time was kept constant and, therefore, mean inspiratory flow was reduced. At high VT, no difference between ACV and APCV was noted for breathing pattern, respiratory drive indexes, respiratory muscle work, or arterial blood gases. All patients exhibited respiratory alkalosis. At moderate VT, normal pH was achieved. In this situation significantly lower levels were observed during APCV than during ACV for the power of breathing (10 +/- 2 versus 19 +/- 5 J/min, p<0.05), transdiaphragmatic pressure swing (7 +/- 1 versus 11 +/- 2 cm H2O, p<0.05), and pressure-time index (252 +/- 43 versus 484 +/- 114 cm H2O.s, p<0.05), even though breathing pattern and gas exchange were similar. In the second part of the study where six additional patients were studied, tidal volume was kept constant at a moderate level (8 ml/kg), and we studied the effect of shortening inspiratory time and increasing mean inspiratory flow. At moderate VT and high inspiratory flow, no significant differences could be found between ACV and APCV, and although pressure-time index tended to be lower during APCV, absolute levels of effort were of small magnitude (56 +/- 55 versus 76 +/- 55 cm H2O.s). We conclude that at moderate VT and low flow rates only, inspiratory assistance delivered at a constant pressure reduces the respiratory work rate more effectively than assist control ventilation. PMID:8630541

  9. Adaptive control of a pressure-controlled artificial ventilator: a simulator-based evaluation using real COPD patient data.

    PubMed

    De Keyser, Robin; Ionescu, Clara

    2011-12-01

    The paper discusses the application of a direct adaptive controller to a pressure controlled artificial ventilation problem. In pressure controlled ventilators, the manipulated variable is the maximum flow applied to the patient during the active phase (inspiration), and the regulated variable is the peak pressure at end-inspiration. This simulation case study focuses on patients diagnosed with Chronic Obstructive Pulmonary Disease (COPD), which require artificial/mechanical ventilation. An adaptive PID controller ensures peak pressures below critical values, by manipulating the flow delivered by the ventilator. The simulation study is performed on fractional-order models of the respiratory impedance identified from lung function data obtained from 21 COPD patients. Additional simulation studies show the robustness of the controller in presence of varying model parameters from the respiratory impedance of the patient. Possibilities to implement the control strategy as an online adaptive algorithm are also explored. The results show that the design of the control is suitable for this kind of application and provides useful insight on realistic scenarios. PMID:21458877

  10. Pressure Dynamic Characteristics of Pressure Controlled Ventilation System of a Lung Simulator

    PubMed Central

    Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

    2014-01-01

    Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems. PMID:25197318

  11. A new design for high stability pressure-controlled ventilation for small animal lung imaging

    NASA Astrophysics Data System (ADS)

    Kitchen, M. J.; Habib, A.; Fouras, A.; Dubsky, S.; Lewis, R. A.; Wallace, M. J.; Hooper, S. B.

    2010-02-01

    We have developed a custom-designed ventilator to deliver a stable pressure to the lungs of small animals for use in imaging experiments. Our ventilator was designed with independent pressure vessels to separately control the Peak Inspiratory Pressure (PIP) and Positive End Expiratory Pressure (PEEP) to minimise pressure fluctuations during the ventilation process. The ventilator was computer controlled through a LabVIEW interface, enabling experimental manipulations to be performed remotely whilst simultaneously imaging the lungs in situ. Mechanical ventilation was successfully performed on newborn rabbit pups to assess the most effective ventilation strategies for aerating the lungs at birth. Highly stable pressures enabled reliable respiratory gated acquisition of projection radiographs and a stable prolonged (15 minute) breath-hold for high-resolution computed tomography of deceased rabbit pups at different lung volumes.

  12. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation.

    PubMed

    Liu, Xiao-Wei; Jin, Yan; Ma, Tao; Qu, Bo; Liu, Zhi

    2015-01-01

    This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (V T ), ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (C rs) decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP) were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2% at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV. PMID:25954759

  13. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation

    PubMed Central

    Liu, Xiao-Wei; Jin, Yan; Ma, Tao; Qu, Bo; Liu, Zhi

    2015-01-01

    This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT), ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (Crs) decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP) were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2 % at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV. PMID:25954759

  14. Randomized clinical trial of pressure-controlled inverse ratio ventilation and extracorporeal CO2 removal for adult respiratory distress syndrome.

    PubMed

    Morris, A H; Wallace, C J; Menlove, R L; Clemmer, T P; Orme, J F; Weaver, L K; Dean, N C; Thomas, F; East, T D; Pace, N L; Suchyta, M R; Beck, E; Bombino, M; Sittig, D F; Böhm, S; Hoffmann, B; Becks, H; Butler, S; Pearl, J; Rasmusson, B

    1994-02-01

    The impact of a new therapy that includes pressure-controlled inverse ratio ventilation followed by extracorporeal CO2 removal on the survival of patients with severe ARDS was evaluated in a randomized controlled clinical trial. Computerized protocols generated around-the-clock instructions for management of arterial oxygenation to assure equivalent intensity of care for patients randomized to the new therapy limb and those randomized to the control, mechanical ventilation limb. We randomized 40 patients with severe ARDS who met the ECMO entry criteria. The main outcome measure was survival at 30 days after randomization. Survival was not significantly different in the 19 mechanical ventilation (42%) and 21 new therapy (extracorporeal) (33%) patients (p = 0.8). All deaths occurred within 30 days of randomization. Overall patient survival was 38% (15 of 40) and was about four times that expected from historical data (p = 0.0002). Extracorporeal treatment group survival was not significantly different from other published survival rates after extracorporeal CO2 removal. Mechanical ventilation patient group survival was significantly higher than the 12% derived from published data (p = 0.0001). Protocols controlled care 86% of the time. Average PaO2 was 59 mm Hg in both treatment groups. Intensity of care required to maintain arterial oxygenation was similar in both groups (2.6 and 2.6 PEEP changes/day; 4.3 and 5.0 FIO2 changes/day). We conclude that there was no significant difference in survival between the mechanical ventilation and the extracorporeal CO2 removal groups. We do not recommend extracorporeal support as a therapy for ARDS. Extracorporeal support for ARDS should be restricted to controlled clinical trials. PMID:8306022

  15. Prone position and pressure control inverse ratio ventilation in H1N1 patients with severe acute respiratory distress syndrome

    PubMed Central

    Venkategowda, Pradeep M.; Rao, S. Manimala; Harde, Yogesh R.; Raut, Mithilesh K.; Mutkule, Dnyaneshwar P.; Munta, Kartik; Rao, Mallela V.

    2016-01-01

    Aim: To observe the 28 and 90 days mortality associated with prone position and assist control-pressure control (with inverse ratio) ventilation (ACPC-IRV). Materials and Methods: All patients who were admitted to our medical Intensive Care Unit (ICU) who are positive for H1N1 viral infection with severe acute respiratory distress syndrome (ARDS) and requiring invasive mechanical ventilation in prone position were included in our prospective observational study. Six patients who are positive for H1N1 required invasive ventilation in prone position. These patients were planned to ventilate in prone for 16 h and in supine for 8 h daily until P/F ratio >150 with FiO2 of 0.6 or less and positive end-expiratory pressure <10 cm of H2 O. Results: At admission, among these six patients the mean tidal volume generated was about 376.6 ml which was in the range of 6–8 ml/kg predicted body weight. The mean lung injury score was 3.79, mean PaO2 /FiO2 ratio was 52.66 and mean oxygenation index was 29.83. The mean duration of ventilation was 9.4 days (225.6 h). The ICU length of stay was 11.16 days. There was no mortality at 28 and 90 days. Conclusion: Early prone combined with ACPC-IRV in H1N1 patients having severe ARDS can be used as a rescue therapy and it should be confirmed by large observational studies. PMID:26955217

  16. Pneumococcal Vaccines (PCV, PPSV)

    MedlinePlus

    ... antineumocócicas (PCV y PPSV) The pneumococcal conjugate vaccine (PCV13) and the pneumococcal polysaccharide vaccine (PPSV23) protect against ... infections as pneumonia , blood infections, and bacterial meningitis . PCV13 protects against 13 types of pneumococcal bacteria (the ...

  17. FISH in polycythemia vera (PCV)

    SciTech Connect

    Amiel, A.; Gaber, E.; Manor, Y.

    1994-09-01

    Trisomies 8 and 9 are the most common numerical abnormalities in polycythemia vera (PCV). However, their role in the pathogenesis of the disease is unclear as is their diagnostic or prognostic value. We evaluated the role of fluorescent in-situ hybridization (FISH) as compared to chromosome analysis in the detection of trisomies 8 or 9 in peripheral blood cells of 14 PCV and 5 secondary PCV patients. Using FISH, we found trisomies 8 and 9 in 10 PCV patients above the cutoff levels of 5%. However, no patient with the secondary PCV reached the cutoff level. Out of 10 PCV patients in whom the trisomy was detected by FISH, only in 3 was this trisomy also detected by routine cytogenetics. The incidence of the finding of trisomy 9 correlates with the duration of the disease, suggesting that this is not the primary event in PCV. FISH is a sensitive, convenient and rapid method for diagnosis and follow-up of chromosome aberrations in PCV patients. Application of FISH to larger cohort of patients may provide valuable information regarding their role in initiation and progession of the disease.

  18. Tracheostomy and mechanical ventilation weaning in children affected by respiratory virus according to a weaning protocol in a pediatric intensive care unit in Argentina: an observational restrospective trial

    PubMed Central

    2011-01-01

    We describe difficult weaning after prolonged mechanical ventilation in three tracheostomized children affected by respiratory virus infection. Although the spontaneous breathing trials were successful, the patients failed all extubations. Therefore a tracheostomy was performed and the weaning plan was begun. The strategy for weaning was the decrease of ventilation support combining pressure control ventilation (PCV) with increasing periods of continuous positive airway pressure + pressure support ventilation (CPAP + PSV) and then CPAP + PSV with increasing intervals of T-piece. They presented acute respiratory distress syndrome on admission with high requirements of mechanical ventilation (MV). Intervening factors in the capabilities and loads of the respiratory system were considered and optimized. The average MV time was 69 days and weaning time 31 days. We report satisfactory results within the context of a directed weaning protocol. PMID:21244710

  19. Impact of Ventilatory Modes on the Breathing Variability in Mechanically Ventilated Infants

    PubMed Central

    Baudin, Florent; Wu, Hau-Tieng; Bordessoule, Alice; Beck, Jennifer; Jouvet, Philippe; Frasch, Martin G.; Emeriaud, Guillaume

    2014-01-01

    Objectives: Reduction of breathing variability is associated with adverse outcome. During mechanical ventilation, the variability of ventilatory pressure is dependent on the ventilatory mode. During neurally adjusted ventilatory assist (NAVA), the support is proportional to electrical activity of the diaphragm (EAdi), which reflects the respiratory center output. The variability of EAdi is, therefore, translated into a similar variability in pressures. Contrastingly, conventional ventilatory modes deliver less variable pressures. The impact of the mode on the patient’s own respiratory drive is less clear. This study aims to compare the impact of NAVA, pressure-controlled ventilation (PCV), and pressure support ventilation (PSV) on the respiratory drive patterns in infants. We hypothesized that on NAVA, EAdi variability resembles most of the endogenous respiratory drive pattern seen in a control group. Methods: Electrical activity of the diaphragm was continuously recorded in 10 infants ventilated successively on NAVA (5 h), PCV (30 min), and PSV (30 min). During the last 10 min of each period, the EAdi variability pattern was assessed using non-rhythmic to rhythmic (NRR) index. These variability profiles were compared to the pattern of a control group of 11 spontaneously breathing and non-intubated infants. Results: In control infants, NRR was higher as compared to mechanically ventilated infants (p < 0.001), and NRR pattern was relatively stable over time. While the temporal stability of NRR was similar in NAVA and controls, the NRR profile was less stable during PCV. PSV exhibited an intermediary pattern. Perspectives: Mechanical ventilation impacts the breathing variability in infants. NAVA produces EAdi pattern resembling most that of control infants. NRR can be used to characterize respiratory variability in infants. Larger prospective studies are necessary to understand the differential impact of the ventilatory modes on the cardio-respiratory variability and to study their impact on clinical outcomes. PMID:25505779

  20. Pathogenesis of PCV2a and PCV2b virus in germ-free pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic analysis of porcine circovirus type 2 (PCV2) reveals 2 subgroups that will be referred to as PCV2a and PCV2b representing the North American and European prototypes respectfully. This paper summarizes 3 studies comparing the pathogenesis of 2a and 2b viruses in germ-free pigs. In this PCV2...

  1. High frequency oscillatory ventilation and prone positioning in a porcine model of lavage-induced acute lung injury

    PubMed Central

    Brederlau, Joerg; Muellenbach, Ralf; Kredel, Markus; Greim, Clemens; Roewer, Norbert

    2006-01-01

    Background This animal study was conducted to assess the combined effects of high frequency oscillatory ventilation (HFOV) and prone positioning on pulmonary gas exchange and hemodynamics. Methods Saline lung lavage was performed in 14 healthy pigs (54 ± 3.1 kg, mean ± SD) until the arterial oxygen partial pressure (PaO2) decreased to 55 ± 7 mmHg. The animals were ventilated in the pressure controlled mode (PCV) with a positive endexpiratory pressure (PEEP) of 5 cmH2O and a tidal volume (VT) of 6 ml/kg body weight. After a stabilisation period of 60 minutes, the animals were randomly assigned to 2 groups. Group 1: HFOV in supine position; group 2: HFOV in prone position. After evaluation of prone positioning in group 2, the mean airway pressure (Pmean) was increased by 3 cmH2O from 16 to 34 cmH2O every 20 minutes in both groups accompanied by measurements of respiratory and hemodynamic variables. Finally all animals were ventilated supine with PCV, PEEP = 5 cm H2O, VT = 6 ml/kg. Results Combination of HFOV with prone positioning improves oxygenation and results in normalisation of cardiac output and considerable reduction of pulmonary shunt fraction at a significant (p < 0.05) lower Pmean than HFOV and supine positioning. Conclusion If ventilator induced lung injury is ameliorated by a lower Pmean, a combined treatment approach using HFOV and prone positioning might result in further lung protection. PMID:16584548

  2. Blood Pressure Control

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Engineering Development Laboratory developed a system for the cardiovascular study of weightless astronauts. This was designed to aid people with congestive heart failure and diabetes. While in space, astronauts' blood pressure rises, heart rate becomes unstable, and there are sometimes postflight lightheadedness or blackouts. The Baro-Cuff studies the resetting of blood pressure. When a silicone rubber chamber is strapped to the neck, the Baro-Cuff stimulates the carotid arteries by electronically controlled pressure application. Blood pressure controls in patients may be studied.

  3. Effects of PCV7 and PCV13 on invasive pneumococcal disease and carriage in Stockholm, Sweden.

    PubMed

    Galanis, Ilias; Lindstrand, Ann; Darenberg, Jessica; Browall, Sarah; Nannapaneni, Priyanka; Sjöström, Karin; Morfeldt, Eva; Naucler, Pontus; Blennow, Margareta; Örtqvist, Åke; Henriques-Normark, Birgitta

    2016-04-01

    The effects of pneumococcal conjugated vaccines (PCVs) need to be investigated. In Stockholm County, Sweden, PCV7 was introduced in the childhood immunisation programme in 2007 and changed to PCV13 in 2010.Over 90% of all invasive isolates during 2005-2014 (n=2336) and carriage isolates, 260 before and 647 after vaccine introduction, were characterised by serotyping, molecular typing and antibiotic susceptibility, and serotype diversity was calculated. Clinical information was collected for children and adults with invasive pneumococcal disease (IPD).The IPD incidence decreased post-PCV7, but not post-PCV13, in vaccinated children. Beneficial herd effects were seen in older children and adults, but not in the elderly. The herd protection was more pronounced post-PCV7 than post-PCV13. PCV7 serotypes decreased. IPD caused by PCV13 serotypes 3 and 19A increased post-PCV7. Post-PCV13, serotypes 6A and 19A, but not serotype 3, decreased. The serotype distribution changed in carriage and IPD to nonvaccine types, also in nonvaccinated populations. Expansion of non-PCV13 serotypes was largest following PCV13 introduction. Serotype diversity increased and nonvaccine clones emerged, such as CC433 (serotype 22F) in IPD and CC62 (serotype 11A) in carriage. In young children, meningitis, septicaemia and severe rhinosinusitis, but not bacteraemic pneumonia, decreased.Pneumococcal vaccination leads to expansion of new or minor serotypes/clones, also in nonvaccinated populations. PMID:26797033

  4. Effects of PCV7 and PCV13 on invasive pneumococcal disease and carriage in Stockholm, Sweden

    PubMed Central

    Galanis, Ilias; Lindstrand, Ann; Darenberg, Jessica; Browall, Sarah; Nannapaneni, Priyanka; Sjöström, Karin; Morfeldt, Eva; Naucler, Pontus; Blennow, Margareta; Örtqvist, Åke

    2016-01-01

    The effects of pneumococcal conjugated vaccines (PCVs) need to be investigated. In Stockholm County, Sweden, PCV7 was introduced in the childhood immunisation programme in 2007 and changed to PCV13 in 2010. Over 90% of all invasive isolates during 2005–2014 (n=2336) and carriage isolates, 260 before and 647 after vaccine introduction, were characterised by serotyping, molecular typing and antibiotic susceptibility, and serotype diversity was calculated. Clinical information was collected for children and adults with invasive pneumococcal disease (IPD). The IPD incidence decreased post-PCV7, but not post-PCV13, in vaccinated children. Beneficial herd effects were seen in older children and adults, but not in the elderly. The herd protection was more pronounced post-PCV7 than post-PCV13. PCV7 serotypes decreased. IPD caused by PCV13 serotypes 3 and 19A increased post-PCV7. Post-PCV13, serotypes 6A and 19A, but not serotype 3, decreased. The serotype distribution changed in carriage and IPD to nonvaccine types, also in nonvaccinated populations. Expansion of non-PCV13 serotypes was largest following PCV13 introduction. Serotype diversity increased and nonvaccine clones emerged, such as CC433 (serotype 22F) in IPD and CC62 (serotype 11A) in carriage. In young children, meningitis, septicaemia and severe rhinosinusitis, but not bacteraemic pneumonia, decreased. Pneumococcal vaccination leads to expansion of new or minor serotypes/clones, also in nonvaccinated populations. PMID:26797033

  5. Pneumococcal conjugate vaccine (PCV13) - What you need to know

    MedlinePlus

    ... www.cdc.gov/vaccines/hcp/vis/vis-statements/pcv13.html CDC review information for Pneumococcal Conjugate VIS: ... the disease, through vaccination, even more important. 2. PCV13 vaccine Pneumococcal conjugate vaccine (called PCV13) protects against ...

  6. Porcine circovirus type 2 (PCV2) vaccination is effective in reducing disease and PCV2 shedding in semen of boars concurrently infected with PCV2 and Mycoplasma hyopneumoniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to determine if the amount of porcine circovirus type 2 (PCV2) shed in semen will be increased in boars experimentally coinfected with Mycoplasma hyopneumoniae (MHYO) and if PCV2 vaccination of the boars prior to PCV2 exposure will result in reduced PCV2 viremia and...

  7. A Chimeric Porcine Circovirus (PCV) with the Immunogenic Capsid Gene of the Pathogenic PCV Type 2 (PCV2) Cloned into the Genomic Backbone of the Nonpathogenic PCV1 Induces Protective Immunity against PCV2 Infection in Pigs

    PubMed Central

    Fenaux, M.; Opriessnig, T.; Halbur, P. G.; Elvinger, F.; Meng, X. J.

    2004-01-01

    Porcine circovirus type 2 (PCV2) is associated with postweaning multisystemic wasting syndrome in pigs, whereas PCV1 is nonpathogenic. We previously demonstrated that a chimeric PCV1-2 virus (with the immunogenic capsid gene of PCV2 cloned into the backbone of PCV1) induces an antibody response to the PCV2 capsid protein and is attenuated in pigs. Here, we report that the attenuated chimeric PCV1-2 induces protective immunity to wild-type PCV2 challenge in pigs. A total of 48 specific-pathogen-free piglets were randomly and equally assigned to four groups of 12 pigs each. Pigs in group 1 were vaccinated by intramuscular injection with 200 μg of the chimeric PCV1-2 infectious DNA clone. Pigs in group 2 were vaccinated by intralymphoid injection with 200 μg of a chimeric PCV1-2 infectious DNA clone. Pigs in group 3 were vaccinated by intramuscular injection with 103.5 50% tissue culture infective doses (TCID50) of the chimeric PCV1-2 live virus. Pigs in group 4 were not vaccinated and served as controls. By 42 days postvaccination (DPV), the majority of pigs had seroconverted to PCV2 capsid antibody. At 42 DPV, all pigs were challenged intranasally and intramuscularly with 2 × 104.5 TCID50 of a wild-type pathogenic PCV2 virus. By 21 days postchallenge (DPC), 9 out of the 12 group 4 pigs were viremic for PCV2. Vaccinated animals in groups 1 to 3 had no detectable PCV2 viremia after challenge. At 21 DPC the lymph nodes in the nonvaccinated pigs were larger (P < 0.05) than those of vaccinated pigs. The PCV2 genomic copy loads in lymph nodes were reduced (P < 0.0001) in vaccinated pigs. Moderate amounts of PCV2 antigen were detected in most lymphoid tissues of nonvaccinated pigs but in only 1 of 36 vaccinated pigs. Mild-to-severe lymphoid depletion and histiocytic replacement were detected in lymphoid tissues in the majority of nonvaccinated group 4 pigs but in only a few vaccinated group 1 to 3 pigs. The data from this study indicated that when given intramuscularly in pigs, the attenuated chimeric PCV1-2 live virus, as well as the chimeric PCV1-2 infectious DNA clone, induces protective immunity against PCV2 infection and could potentially serve as an effective vaccine. PMID:15163723

  8. Tank Pressure Control Experiment (TPCE)

    NASA Technical Reports Server (NTRS)

    Bentz, Mike

    1992-01-01

    The Tank Pressure Control Experiment (TPCE) is a small self-contained STS payload designed to test a jet mixer for cryogenic fluid pressure control. Viewgraphs are presented that describe project organization, experiment objectives and approach, risk management, payload concept and mission plan, and initial test data.

  9. Singular PCV2a or PCV2b infection results in apoptosis of hepatocytes in clinically affected gnotobiotic pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine circovirus type 2 (PCV2) which can be further subdivide into two main genotypes, PCV2a and PCV2b, is often clinically associated with respiratory signs, failure-to-thrive, and diarrhea. The precise pathogenesis of PCV2, and in particular its involvement in apoptosis, is controversial. The ob...

  10. Singular PCV2a or PCV2b Infection Results in Apoptosis of Hepatocytes in Clinically Affected Gnotobiotic Pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Systemic infection with porcine circovirus type 2 (PCV2) is often clinically associated with respiratory signs, failure to thrive and diarrhea [1]. Currently, PCV2 can be further subdivided into two main genotypes, PCV2a and PCV2b which under experimental conditions result in very simi...

  11. Identification of natural recombinants derived from PCV2a and PCV2b.

    PubMed

    Hu, J; Zhai, S L; Zeng, S Y; Sun, B B; Deng, S F; Chen, H L; Zheng, Y; Wang, H X; Li, X P; Liu, J K; Cheng, S; Zhou, X; Zhai, J Q; Luo, M L

    2015-01-01

    Porcine circovirus type 2 (PCV2) is considered to be the main pathogen in PC-associated diseases, and significantly affects the global pig-producing industry. PCV2 continuously evolves by point mutations and genome recombinations. In the present study, we aimed to further identify recombinant PCV2 strains. We used polymerase chain reaction to detect PCV2 in the carcasses of pigs with suspected infections from different regions of Guangdong Province in China. DNA was extracted from samples with confirmed infection and full- genome amplification, sequencing, phylogenetic tree construction, gene recombination detection, and sequence alignment were performed in gene recombination analysis. Our results show that recombination occurred between the strains SHC (DQ104421) and ZhuJi2003 (AY579893). The recombination resulted in three recombinants: GD003 (KM503044), GD005 (KM487708), and GD008 (KM487709). Further analyses revealed that these novel recombinants appeared to result from recombination between the PCV2a and PCV2b strains, with crossover regions located in ORF2. This study was a comprehensive analysis that used several different methods, which demonstrated that a cluster of PCV2 strains resulted from the same type of inter-genotypic recombination pattern, with a breakpoint in the structural protein coding region. The results of our study provide both information on the recombination mechanism and disease pathogenesis and useful data for the prevention of PCV2 in the swine industry. PMID:26436503

  12. Origin of porcine circovirus type 2 (PCV2) from swine affected by PCV2-associated diseases in Croatia.

    PubMed

    Novosel, D; Tuboly, T; Csagola, A; Lorincz, M; Cubric-Curik, V; Jungic, A; Curik, I; Segalés, J; Cortey, M; Lipej, Z

    2014-04-26

    Porcine circovirus type 2 (PCV2) causes some of the most significant economic losses in pig production. Several multisystemic syndromes have been attributed to PCV2 infection, which are known as PCV2-associated diseases (PCVDs). This study investigated the origin and evolution of PCV2 sequences in domestic pigs and wild boars affected by PCVDs in Croatia. Viral sequences were recovered from three wild boars diagnosed with PCV2-systemic disease (PCV2-SD), 63 fetuses positive for PCV2 DNA as determined by PCR, 14 domestic pigs affected with PCV2-SD (displaying severe interstitial nephritis) and five domestic pigs with proliferative and necrotising pneumonia. Seventeen complete PCV2 genomes were recovered. Phylogenetic and evolutionary analyses based on median-joining phylogenetic networks, amino acid alignments and principal coordinate analysis were performed using complete genomes, as well as complete and partial ORF sequences for ORF1 and ORF2. Two of the 17 PCV2 sequences belonged to PCV2a, 14 to PCV2b and one was unclustered. PCV2b was the predominant genotype in Croatia and has been linked to international trade as a route of introduction. Correlation between particular viral strains with PCVDs is lacking. PMID:24591478

  13. Phylogenetic analysis of porcine circovirus type 2 (PCV2) isolates from China with high homology to PCV2c.

    PubMed

    Liu, Xing; Wang, Feng-Xue; Zhu, Hong-Wei; Sun, Na; Wu, Hua

    2016-06-01

    Porcine circovirus type 2 (PCV2) is an important emerging pathogen that has been causatively associated with multifactorial disease syndromes in pigs and other species. It has a worldwide distribution and causes significant economic losses in the swine industry. Its genome is dynamically evolving through recombination and mutation, and the circulating genotypes of PCV2 strains in Asia are PCV2a, PCV2b and PCV2d. In this study, 12 PCV isolates were evaluated and identified by amplification, sequencing, and phylogenetic analysis, and the results revealed a new monophyletic group of PCV in China. More importantly, three of these isolates shared high homology within the ORF1 region with a strain of genotype PCV2c that was detected only in Denmark. Phylogeographic analysis of these isolates suggested that the isolates may have arisen in Denmark and that they were then transported to China. PMID:27016927

  14. [Porcine circovirus type 2 and PCV2-systemic disease--a review].

    PubMed

    Gu, Jinyan; Xing, Gang; Lei, Jing; Liu, Fei; Zhou, Jiyong

    2015-06-01

    Porcine circovirus type 2 (PCV2) can cause immunosuppression on herds. PCV2, as an essential pathogen of PCV2-systemic disease (PCV2-SD), has caused considerable economic losses in pig industry worldwide. Here we review and address the evolution, viral protein and immunolesion of PCV2 and preventive techniques of PCV2-SD. PMID:26672364

  15. Ventilation and ventilators.

    PubMed

    Hayes, B

    1982-01-01

    The history of ventilation is reviewed briefly and recent developments in techniques of ventilation are discussed. Operating features of ventilators have changed in the past few years, partly as the result of clinical progress; yet, technology appears to have outstripped the clinician's ability to harness it most effectively. Clinical discipline and training of medical staff in the use of ventilators could be improved. The future is promising if clinician and designer can work together closely. Ergonomics of ventilators and their controls and the provision of alarms need special attention. Microprocessors are likely to feature prominently in the next generation of designs. PMID:6754938

  16. Global molecular genetic analysis of porcine circovirus type 2 (PCV2) sequences confirms the presence of four main PCV2 genotypes and reveals a rapid increase of PCV2d.

    PubMed

    Xiao, Chao-Ting; Halbur, Patrick G; Opriessnig, Tanja

    2015-07-01

    The oldest porcine circovirus type 2 (PCV2) sequence dates back to 1962 and is among several hundreds of publicly available PCV2 sequences. Despite this resource, few studies have investigated the global genetic diversity of PCV2. To evaluate the phylogenetic relationship of PCV2 strains, 1680 PCV2 open reading frame 2 (ORF2) sequences were compared and analysed by methods of neighbour-joining, maximum-likelihood, Bayesian inference and network analysis. Four distinct clades were consistently identified and included PCV2a, PCV2b, PCV2c and PCV2d; the p-distance between PCV2d and PCV2b was 0.055±0.008, larger than the PCV2 genotype-definition cut-off of 0.035, supporting PCV2d as an independent genotype. Among the 1680 sequences, 278-285 (16.5-17 %) were classified as PCV2a, 1007-1058 (59.9-63 %) as PCV2b, three (0.2 %) as PCV2c and 322-323 (19.2 %) as PCV2d, with the remaining 12-78 sequences (0.7-4.6 %) classified as intermediate clades or strains by the various methods. Classification of strains to genotypes differed based on the number of sequences used for the analysis, indicating that sample size is important when determining classification and assessing PCV2 trends and shifts. PCV2d was initially identified in 1999 in samples collected in Switzerland, now appears to be widespread in China and has been present in North America since 2012. During 2012-2013, 37 % of all investigated PCV2 sequences from US pigs were classified as PCV2d and overall data analysis suggests an ongoing genotype shift from PCV2b towards PCV2d. The present analyses indicate that PCV2d emerged approximately 20 years ago. PMID:25711965

  17. Susceptibility of calves to porcine circovirus-2 (PCV2).

    PubMed

    Halami, Mohammad Y; Freick, Markus; Shehata, Awad A; Müller, Hermann; Vahlenkamp, Thomas W

    2014-09-17

    Circoviruses are known to infect pigs and birds and cause severe diseases with various clinical signs. Porcine circovirus-2 (PCV2), associated with severe economic losses, was detected in rodents, mosquitoes, cattle, and in calves affected with bovine neonatal pancytopenia (BNP). However, molecular and serological investigations on circovirus infections in cattle revealed inconsistent results. The aim of the study was to investigate the susceptibility and immune response of calves to experimental PCV2 inoculation. Animals were either intravenously inoculated with tissue-culture grown PCV2, with bone marrow from PCV2 positive and negative calves or immunized with a commercial inactivated PCV2 vaccine. The results showed that the animals inoculated with tissue-culture grown PCV2 and with PCV2 positive bone marrow displayed clinical signs including lymph node swelling, reddening of oral and ocular mucosa, and diarrhoea 7-18 days post inoculation (p.i.). PCV2-specific antibodies were detected in the tissue-culture grown PCV2-infected animals and in the PCV2-immunized animals from day 11 and 7 p.i. onwards, respectively, but were absent in both bone marrow inoculated groups. PCV2 was detected by real-time quantitative PCR only in blood samples of the tissue-culture grown PCV2-infected animals and in various tissues (e.g. spleen, lymph nodes, thymus), with high copy numbers in blood between day 4 (5.16log10 genomic copy number/ml) and 46 (5.33log10 genomic copy number/ml) p.i. In conclusion, the seroconversion and the detection of PCV2 in lymphoid tissues for more than five weeks p.i. revealed that host susceptibility of PCV2 is not solely restricted to pigs. PMID:25085519

  18. Intensive care ventilators.

    PubMed

    1998-01-01

    Intensive care ventilators are used to provide ventilatory support for patients who cannot breathe on their own or who require assistance to maintain adequate ventilation. Patients ventilated by these devices can range in age from neonates to adults and can vary in condition from very critical, unstable patients to relatively stable postoperative patients. While intensive care ventilators are typically used in critical care areas of the hospital, they may be used in other care areas as well. In this study, we evaluated seven ventilators specified for intensive care applications. Four of the evaluated models offer the full variety of features needed to make a unit appropriate for a broad range of intensive care applications--for example, they offer both volume- and pressure-controlled modes of ventilation. We labeled these models comprehensive-capability units. The remaining three units lacked certain features, such as a pressure-controlled mode of ventilation, that limited their suitability for some applications. We labeled these models limited-capability units and rated them separately from the comprehensive-capability units. Although some users may find that a limited-capability unit can meet their needs, we believe that most facilities will want to select a ventilator from the more comprehensive category. We used the same ratings rationale for both categories of units, focusing largely on performance (e.g., accuracy, functionality) and safety considerations for adult and pediatric intensive care applications. We also considered ease of use, quality of construction, and reliability. For several of the evaluated units, we identified significant safety shortcomings that prevented us from rating the units Acceptable. In each of the two categories, we rated one unit Conditionally Acceptable and one unit Conditionally Acceptable--Not Recommended. PMID:9809256

  19. PCV2 Vaccination Prevented Clinical PCVAD and Reduced PCV2 Viremia and Semen Shedding in Boars Concurrently Infected with PCV2b and Mycoplasma hyopneumoiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. It has been determined that porcine circovirus type 2 (PCV2) DNA is shed in semen of naturally and experimentally infected boars (1). Recently, it also has been shown that PCV2 DNA present in semen is infectious in a swine bioassay model (2). However, under experimental conditions the ...

  20. Comparison of three commercial one-dose porcine circovirus type 2 (PCV2) vaccines in a herd with concurrent circulation of PCV2b and mutant PCV2b.

    PubMed

    Jeong, Jiwoon; Park, Changhoon; Choi, Kyuhyung; Chae, Chanhee

    2015-05-15

    Porcine circovirus associated disease (PCVAD) occurred in a farm where pigs had been routinely vaccinated with a commercial PCV2a vaccine. A mutant PCV2b (mPCV2b) was isolated from pigs with PCVAD, perhaps implying a perceived vaccine failure. The objective of this study was to determine and compare the efficacy of 3 one-dose PCV2a vaccines of varying antigen type and dose in the same pig farm with concurrent PCV2b and mPCV2b infection based on clinical (average daily weight gain; ADWG), virological (evidence of viremia), immunological (presence of PCV2-specific neutralizing antibody; NA and interferon-γ secreting cells; IFN-γ-SC), and pathological (lymphoid lesion and PCV2 antigen score within lesion) evaluation. Regardless of which commercial PCV2a vaccine was used, vaccinated animals improved ADWG, and reduced the amount of PCV2b and mPCV2b load in the blood compared to unvaccinated animals. The vaccination of piglets at 3 weeks of age effectively induced higher levels of PCV2b- and mPCV2b-specific NA and IFN-γ-SC compared to unvaccinated animals. A reduction in mPCV2b load in the blood coincided with the appearance of both mPCV2b-specific NA and IFN-γ-SC in the vaccinated animals. The microscopic lymphoid lesions and PCV2-antigen scores within the lymph nodes were significantly lower in vaccinated animals. The perceived vaccine failure could not be explained by incomplete protection of the commercial PCV2a vaccine against mPCV2b. The results of the present study demonstrated that currently available commercial PCV2a vaccines are protective against concurrent PCV2b and mPCV2b infection based on clinical, virological, immunological, and pathological evaluations under field conditions. PMID:25790733

  1. Porcine Circovirus (PCV) Removal by Q Sepharose Fast Flow Chromatography

    PubMed Central

    Yang, Bin; Wang, Hua; Ho, Cintia; Lester, Philip; Chen, Qi; Neske, Florian; Baylis, Sally A; Blümel, Johannes

    2013-01-01

    The recently discovered contamination of oral rotavirus vaccines led to exposure of millions of infants to porcine circovirus (PCV). PCV was not detected by conventional virus screening tests. Regulatory agencies expect exclusion of adventitious viruses from biological products. Therefore, methods for inactivation/removal of viruses have to be implemented as an additional safety barrier whenever feasible. However, inactivation or removal of PCV is difficult. PCV is highly resistant to widely used physicochemical inactivation procedures. Circoviruses such as PCV are the smallest viruses known and are not expected to be effectively removed by currently-used virus filters due to the small size of the circovirus particles. Anion exchange chromatography such as Q Sepharose® Fast Flow (QSFF) has been shown to effectively remove a range of viruses including parvoviruses. In this study, we investigated PCV1 removal by virus filtration and by QSFF chromatography. As expected, PCV1 could not be effectively removed by virus filtration. However, PCV1 could be effectively removed by QSFF as used during the purification of monoclonal antibodies (mAbs) and a log10 reduction value (LRV) of 4.12 was obtained. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1464–1471, 2013 PMID:24039195

  2. Solenoid operated pressure control valve

    SciTech Connect

    McAuliffe, L. Jr.

    1991-03-12

    This patent describes a solenoid actuated fluid pressure control valve. It includes a housing having a central passage extending vertically downwardly from a first port adapted to be connected to a fluid sump and located at the upper end of the housing to a second port adapted to be connected to a source of fluid pressure and located adjacent the lower end of the housing, a solenoid coil mounted within the housing intermediate the upper and lower ends thereof in coaxial relationship with the central passage, an elongate tubular valve body sealingly seated in the central passage with the upper end of the valve body projecting above the lower end of the coil and the lower end of the body located above the second port, a flow passage extending through the valve body from a lower downwardly facing frusto conical valve seat opening into the central passage at the lower end of the body to an upper upwardly facing valve seat at the upper end of the body opening into the central passage at the upper end of the body, means defining a third port in the housing in constant fluid communication with the flow passage at a location between the upper valve seat and the lower valve seat, a ball located in the flow passage between and the lower valve seat and the second port operable when seated against the lower valve seat to block fluid communication between the second port and that portion of the flow passage above the lower valve seat, a solenoid armature received in the central passage between the upper valve seat and the first port and having means at its lower end operable when engaged with the upper valve seat to block fluid communication between the flow passage and that portion of the central passage above the upper valve seat.

  3. Assisted Ventilation.

    PubMed

    Dries, David J

    2016-01-01

    Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear. PMID:25501776

  4. Building pressurization control with rooftop air conditioners

    SciTech Connect

    Winter, S.

    1982-10-01

    The modulated exhaust fan appears to be the most cost effective positive means to maintain close building pressure control with rooftop air conditioning, but because building construction and applications vary, every building's pressure control needs must be analyzed. Requirements will vary from no relief to barometric dampers to return fans to modulated exhaust fans. As heating and cooling costs continue to rise and tighter building codes prevail, proper selection of building pressure control is one area that must be monitored more carefully by the HVAC system designer.

  5. Controller modeling and evaluation for PCV electro-mechanical actuator

    NASA Technical Reports Server (NTRS)

    Parker, Joey K.

    1993-01-01

    Hydraulic actuators are currently used to operate the propellant control valves (PCV) for the space shuttle main engine (SSME) and other rocket engines. These actuators are characterized by large power to weight ratios, large force capabilities, and rapid accelerations, which favor their use in control valve applications. However, hydraulic systems are also characterized by susceptibility to contamination, which leads to frequent maintenance requirements. The Control Mechanisms Branch (EP34) of the Component Development Division of the Propulsion Laboratory at the Marshall Space Flight Center (MSFC) has been investigating the application of electromechanical actuators as replacements for the hydraulic units in PCV's over the last few years. This report deals with some testing and analysis of a PCV electromechanical actuator (EMA) designed and fabricated by HR Textron, Inc. This prototype actuator has undergone extensive testing by EP34 personnel since early 1993. At this time, the performance of the HR Textron PCV EMA does not meet requirements for position tracking.

  6. Genetic characterisation and phylogenetic analysis of PCV2 isolates from India: indications for emergence of natural inter-genotypic recombinants.

    PubMed

    Anoopraj, R; Rajkhowa, Tridib K; Cherian, Susan; Arya, Rahul S; Tomar, Neelam; Gupta, Ashish; Ray, Pradeep K; Somvanshi, R; Saikumar, G

    2015-04-01

    Porcine circovirus type 2 (PCV2), the necessary agent in pathogenesis of porcine circovirus diseases (PCVDs), has a worldwide distribution and is considered as one of the most important emerging viral pathogens of economic importance. PCV2 has been divided into four major genotypes namely PCV2a with five clusters or subtypes (2A-2E), PCV2b with three clusters (1A-1C), PCV2c and PCV2d, based on capsid (cap) gene analysis. PCV2 genome is rapidly evolving through events of recombination and mutation. Though, PCV2a was the predominant genotype initially, PCV2b shared majority of PCV2 sequences submitted to GenBank since 2003. In India, data regarding molecular characterisation of PCV2 is scant or absent. In the present study, we thoroughly analysed genetic heterogeneity of PCV2 strains circulating in Indian pig population. The results revealed that pigs in this region harboured PCV2 viruses of different genotypes including PCV2a-2D, PCV2b-1C and PCV2d. More interestingly, two isolates (PCV2Izn-89-13 and PCV2Izn-218-13) were classified as recombinant strains. Further detailed analysis suggested that these strains evolved from inter-genotypic recombination between PCV2a-2C and PCV2b-1C genotypes within cap gene. This study reports for the first time, the emergence of recombinant PCV2 strains in the Indian pig population. PMID:25592870

  7. EFFECT OF PORCINE CIRCOVIRUS TYPE 2 (PCV2) VACCINATION ON PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS (PRRSV) AND PCV2 COINFECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were (1) to determine if PCV2 vaccination is effective in reducing disease and lesions associated with PRRSV and PCV2 coinfection and (2) to determine if there is a difference between intradermal (ID) and intramuscular (IM) route of PCV2 vaccination. Seventy-four, 21 day...

  8. A commercial PCV2a-based vaccine is effective in protection from experimental challenge of PCV2 mutant with two amino acids elongation in capsid protein.

    PubMed

    Guo, Long-Jun; Fu, Yu-Jie; Huang, Li-Ping; Wang, Yi-Ping; Wei, Yan-Wu; Wu, Hong-Li; Liu, Chang-Ming

    2015-07-17

    Current commercial PCV2 vaccines are almost based on PCV2a and have been shown to be effective in reducing PCV2a and PCV2b viremia and PCV2-associated lesions and diseases. The recent emergence of novel mutant PCV2 (mPCV2) strains and linkage of mPCV2 with cases of porcine circovirus associated disease (PCVAD) in pig herds have raised concerns over emergence of vaccine-escape mutants and reduced efficacy of PCV2a-based vaccines. The aim of this study was to determine the ability of a commercial PCV2a-based vaccine developed by our laboratory to protect conventional pigs against experimental challenge with mPCV2 at 9 weeks of age. Twenty 4-week-old pigs free of PCV2 infection were randomly divided into four treatment groups with 5 pigs each. Two groups were unvaccinated as positive and negative controls. Another two groups were vaccinated with the commercial PCV2a-based vaccine (PCV2-LG strain, China) at 4 weeks of age and identical booster immunization was conducted 3 weeks post primary immunization. At 9 weeks of age, all pigs except the negative control were challenged with a mutant PCV2b/YJ (mPCV2b/YJ) with two amino acids elongation in capsid protein. The experiment was terminated 28 days after challenge. Under the conditions of this study, vaccinated pigs were protected against PCV2 viremia and lesions whereas unvaccinated pigs were not. Moreover, mPCV2b/YJ infection was demonstrated in positive control and almost all had macroscopic or microscopic lesions consistent with PCVAD while negative control did not develop PCVAD. This study indicates that mPCV2b/YJ infection alone can trigger PCVAD development and that the commercial vaccine (PCV2-LG) is still effective in protecting conventional pigs against the emerging mPCV2b/YJ strain in China. PMID:26051516

  9. Industrial ventilation

    NASA Astrophysics Data System (ADS)

    Goodfellow, H. D.

    Industrial ventilation design methodology, using computers and using fluid dynamic models, is considered. It is noted that the design of a ventilation system must be incorporated into the plant design and layout at the earliest conceptual stage of the project. A checklist of activities concerning the methodology for the design of a ventilation system for a new facility is given. A flow diagram of the computer ventilation model shows a typical input, the initialization and iteration loop, and the output. The application of the fluid dynamic modeling techniques include external and internal flow fields, and individual sources of heat and contaminants. Major activities for a ventilation field test program are also addressed.

  10. Genetic characterisation of Porcine circovirus type 2 (PCV2) strains from feral pigs in the Brazilian Pantanal: An opportunity to reconstruct the history of PCV2 evolution.

    PubMed

    Franzo, Giovanni; Cortey, Martí; de Castro, Alessandra Marnie Martins Gomes; Piovezan, Ubiratan; Szabo, Matias Pablo Juan; Drigo, Michele; Segalés, Joaquim; Richtzenhain, Leonardo José

    2015-07-01

    Since its discovery, Porcine circovirus type 2 has emerged as one of the most relevant swine infectious diseases, causing relevant economic losses for the pig industry. While four genotypes were identified, only three (PCV2a, PCV2b and PCV2d) are currently circulating and display a worldwide distribution. Another genotype, PCV2c, has been described only once in Danish archive samples collected between 1980 and 1990. In addition to commercial pigs, PCV2 has been demonstrated to infect wild boars and other wild species, which can potentially serve as a reservoir for domestic populations. In this study, eight sequences obtained from feral pigs in the Pantanal region (Mato Grosso do Sul State, Brazil) were compared with reference sequences and other Brazilian sequences, and the results revealed remarkable genetic diversity, with all four genotypes currently recognised being detected (PCV2a, PCV2b, PCV2c and PCV2d). This finding represents a remarkable discovery, as it is the first detection of PCV2c since 1990 and the first-ever detection of PCV2c in live animals. The peculiar population history and ecological scenario of feral pigs in the Pantanal coupled with the complex, and still only partially known relationship of feral pigs with other PCV2 susceptible species (i.e., domestic pigs, wild boars and peccaries), open exciting questions concerning PCV2 origin and evolution. Overall, the results of the present study led us to form the following hypothesis: the PCV2 strains found in feral pigs may be the last descent of the strains that circulated among European pigs in the past, or they may have infected these feral pigs more recently through a bridge species. PMID:25975522

  11. Five winters of pneumococcal serotype replacement in UK carriage following PCV introduction

    PubMed Central

    Gladstone, Rebecca A.; Jefferies, Johanna M.; Tocheva, Anna S.; Beard, Kate R.; Garley, David; Chong, Wei Wei; Bentley, Stephen D.; Faust, Saul N.; Clarke, Stuart C.

    2015-01-01

    The seven-valent pneumococcal conjugate vaccine (PCV7) was added to the UK national immunisation programme in September 2006. PCV13 replaced PCV7 in April 2010. As carriage precedes disease cases this study collected carried pneumococci from children each winter from 2006/7 to 2010/11 over PCV introduction. Conventional microbiology and whole genome sequencing were utilised to characterise pneumococcal strains. Overall prevalence of pneumococcal carriage remained stable. Vaccine serotypes (VT) decreased (p < 0.0001) with concomitant increases in non-vaccine serotypes (NVT). In winter 2010/11 only one isolate of PCV7 VT was observed (6B). PCV13 unique VTs decreased between winters immediately preceding and following PCV13 introduction (p = 0.04). Significant decreases for VTs 6B, 19F, 23F (PCV7) and 6A (PCV13) and increases for NVT 21, 23B, 33F and 35F were detected. The serotype replacement was accompanied by parallel changes in genotype prevalence for associated sequence types with clonal expansion contributing to replacement. By winter 2010/11, serotype coverage of PCV7 and PCV13 was 1% and 11% respectively. VT replacement was observed for PCV7 and PCV13 serotypes. Conjugate vaccine design and use requires continuous monitoring and revision. PMID:25776920

  12. Five winters of pneumococcal serotype replacement in UK carriage following PCV introduction.

    PubMed

    Gladstone, Rebecca A; Jefferies, Johanna M; Tocheva, Anna S; Beard, Kate R; Garley, David; Chong, Wei Wei; Bentley, Stephen D; Faust, Saul N; Clarke, Stuart C

    2015-04-21

    The seven-valent pneumococcal conjugate vaccine (PCV7) was added to the UK national immunisation programme in September 2006. PCV13 replaced PCV7 in April 2010. As carriage precedes disease cases this study collected carried pneumococci from children each winter from 2006/7 to 2010/11 over PCV introduction. Conventional microbiology and whole genome sequencing were utilised to characterise pneumococcal strains. Overall prevalence of pneumococcal carriage remained stable. Vaccine serotypes (VT) decreased (p<0.0001) with concomitant increases in non-vaccine serotypes (NVT). In winter 2010/11 only one isolate of PCV7 VT was observed (6B). PCV13 unique VTs decreased between winters immediately preceding and following PCV13 introduction (p=0.04). Significant decreases for VTs 6B, 19F, 23F (PCV7) and 6A (PCV13) and increases for NVT 21, 23B, 33F and 35F were detected. The serotype replacement was accompanied by parallel changes in genotype prevalence for associated sequence types with clonal expansion contributing to replacement. By winter 2010/11, serotype coverage of PCV7 and PCV13 was 1% and 11% respectively. VT replacement was observed for PCV7 and PCV13 serotypes. Conjugate vaccine design and use requires continuous monitoring and revision. PMID:25776920

  13. [Collateral ventilation].

    PubMed

    Voshaar, Th H

    2008-06-01

    The phenomenon of collateral ventilation is defined as ventilation of alveolar structures through passages or channels that bypass the normal airways. Such bypassing structures can be interalveolar, bronchiole-alveolar, interbronchiole, and interlobar. Collateral ventilation structures seem to be prominent in human lungs with trapped air and emphysema. In healthy human lungs normally no relevant collateral ventilation can be detected. In emphysematic lungs the ventilation through collateral channels can probably improve gas exchange mechanisms. The phenomenon of collateral ventilation explains several clinical observations in human lungs such as the absence of atalectasis following complete bronchial obstruction, e. g. after foreign body aspiration or tumour. The various results after bronchoscopic implantation of one-way endobronchial valves as a new technique for treating emphysema can also be explained by collateral ventilation. Understanding collateral ventilation is of high importance for clinicians, those working in the field of physiology of emphysema in human lungs and may be central to planning new bronchoscopic techniques for treating emphysema. The paper offers an overview of history, physiology and the relevance for lung volume reduction methods. Moreover, a new imaging technique to demonstrate collateral ventilation in vivo is described. PMID:18535980

  14. Protective effect of the maternally derived porcine circovirus type 2 (PCV2)-specific cellular immune response in piglets by dam vaccination against PCV2 challenge.

    PubMed

    Oh, Yeonsu; Seo, Hwi Won; Han, Kiwon; Park, Changhoon; Chae, Chanhee

    2012-07-01

    The objective of the present study was to evaluate (i) the passive transfer of maternally derived functional porcine circovirus type 2 (PCV2)-specific lymphocytes of seronegative sows immunized with the PCV2 vaccine to newborn piglets and (ii) the functional role of the maternally derived PCV2-specific cellular immune response in protecting newborn piglets from challenge with PCV2. After ingesting colostrums, piglets from vaccinated sows (PT01 and PT02) have significantly higher numbers of PCV2-specific gamma interferon-secreting cells, an increased PCV2-specific delayed type hypersensitivity response, and a stronger proliferative response of peripheral blood mononuclear cells compared with piglets from non-vaccinated seronegative sows (PT03 and PT04). In the PCV2 challenge study, the number of serum genomic PCV2 copies was significantly less in piglets from vaccinated sows (PT02) compared with piglets from non-vaccinated sows (PT04) at 7-28 days post-inoculation (P<0.05 and P<0.001). The histopathological lesions and immunohistochemical scores were significantly lower in piglets of vaccinated sows compared with those of non-vaccinated sows. To our knowledge, this is the first report of transferring a maternally derived PCV2-specific cellular immune response from vaccinated dams to their offspring. Maternally derived adaptive cellular immune responses play a critical role in protecting newborn piglets challenged with PCV2 at 3 weeks of age. PMID:22495234

  15. Ventilation Model

    SciTech Connect

    H. Yang

    1999-11-04

    The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future.

  16. Ventilation Model

    SciTech Connect

    V. Chipman

    2002-10-05

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. The purposes of Revision 01 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to initialize post-closure thermal models (Section 6.6). (3) To satisfy the remainder of KTI agreement TEF 2.07 (Reamer and Williams 2001b). Specifically to provide the results of post-test ANSYS modeling of the Atlas Facility forced convection tests (Section 7.1.2). This portion of the model report also serves as a validation exercise per AP-SIII.10Q, Models, for the ANSYS ventilation model. (4) To further satisfy KTI agreements RDTME 3.01 and 3.14 (Reamer and Williams 2001a) by providing the source documentation referred to in the KTI Letter Report, ''Effect of Forced Ventilation on Thermal-Hydrologic Conditions in the Engineered Barrier System and Near Field Environment'' (Williams 2002). Specifically to provide the results of the MULTIFLUX model which simulates the coupled processes of heat and mass transfer in and around waste emplacement drifts during periods of forced ventilation. This portion of the model report is presented as an Alternative Conceptual Model with a numerical application, and also provides corroborative results used for model validation purposes (Section 6.3 and 6.4).

  17. Liquid ventilation.

    PubMed

    Sehgal, Arvind; Guaran, Robert

    2005-01-01

    Respiratory diseases are the commonest cause of morbidity and mortality in newborn babies. During the past few years several new modalities of treatment like surfactant have been introduced. One of them, and probably the most fascinating, is of liquid ventilation. Partial liquid ventilation, on which much of the existing research has concentrated, requires partial filling of lungs with perfluorocarbons (PFC's) and ventilation with gas tidal volumes using a conventional mechanical ventilators. Various physico-chemical properties of PFC's make them the ideal media. It results in a dramatic improvement in lung compliance and oxygenation and decline in mean airway pressure and oxygen requirements. It shows further promise for lung lavaging procedures, pulmonary image enhancement, pulmonary administration of drugs and as a technique to increase functional residual capacity in lung hypoplasia syndromes. There are no long-term side effect reported. PMID:16022146

  18. Detection of PCV-2 DNA in stool samples from infants vaccinated with RotaTeq

    PubMed Central

    Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Yen, Catherine; Parashar, Umesh D; Gentsch, Jon R; Bowen, Michael D; LaRussa, Philip

    2014-01-01

    Rotarix and RotaTeq vaccines have led to a dramatic reduction in rotavirus disease worldwide. However, the detection of porcine circovirus type 1 (PCV-1) and 2 (PCV-2) DNA in these vaccines raised some safety concerns. Studies examining shedding of rotavirus in stool from rotavirus vaccine recipients have been performed but no published data exist regarding the shedding of PCV virus in stools of vaccinees. The goal of this study was to determine if PCV-1 and/or PCV-2 is shed in the feces of infants vaccinated with RotaTeq. Using multiple PCR assays for detection of PCV DNA, we tested for PCV-1 and PCV-2 in 826 stool swab samples collected serially during the first 9 d after vaccination from 102 children vaccinated with RotaTeq. Since the vaccine is recommended and uptake is high, we did not have samples from unvaccinated infants. A total of 235 (28.5%) samples from 59 vaccine recipients were positive for PCV-2 DNA by one or more assays used in this study. PCV-1 DNA was not detected in RotaTeq or any of the stool swab extracts. Twenty-two of the 102 vaccine recipients (21.6%) shed RotaTeq vaccine strain and 10 of these vaccinees (9.8%) were shedding both PCV DNA and rotavirus vaccine RNA. PCV DNA was detected up to 9 d post vaccination and was most frequently detected in the first 5 d after vaccination. This study demonstrated shedding of PCV-2 DNA by RotaTeq vaccinees but we did not find evidence that this DNA was associated with viable PCV. Findings from this study support the continued use of current rotavirus vaccines. PMID:24104203

  19. Pneumococcal nasopharyngeal carriage in children <5  years of age visiting the pediatric emergency room in relation to PCV7 and PCV13 introduction in southern Israel.

    PubMed

    Ben-Shimol, Shalom; Givon-Lavi, Noga; Greenberg, David; Dagan, Ron

    2016-02-01

    The 7-valent and the 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13, respectively) were introduced to the Israeli National Immunization plan in July 2009 and November 2010, respectively. Our aim was to assess pneumococcal conjugate vaccines (PCVs) uptake and dynamics in serotype-specific pneumococcal nasopharyngeal (NP) carriage in children <5  years old in southern Israel, during the immediate 5 y following PCV introduction. This was an ongoing, prospective, population-based, active surveillance, from July 2009 through December 2014. PCVs uptake and NP cultures were obtained daily from children seen at the Pediatric Emergency Room for any reason. Overall, 10,702 vaccine status and 7,610 NP swabs were obtained. Both PCV7 and PCV13 uptake were high, reaching ˜90% by July 2012 and December 2013, respectively. All-pneumococcal carriage rates significantly declined by 10%, from 54.3% in the early-PCV7 period, to 49.1% in the PCV13 impact period. The respective declines for PCV7, 6A and additional PCV13 serotypes carriage rates were 76%, 90% and 66%. In contrast, non-PCV13 serotypes carriage rates increased significantly throughout the study by 71%. All-pneumococcal carriage rates in children <12  months old decreased significantly by 15%, with similar trends observed in other age groups. Initially, all-pneumococcal carriage rates were 45.7%, and 61.9% in Jewish and Bedouin children, respectively (P < 0.001), with a significant 17% reduction throughout the study observed only in Bedouins. While early carriage rates were higher in unvaccinated children compared to vaccinated children, PCV impact on carriage were similar in both groups. In conclusion, a relatively moderate decline in pneumococcal carriage rates, facilitated by a substantial decrease of vaccine-serotypes and increase of non-vaccine serotypes was observed in the immediate period following PCVs introduction in southern Israel. PMID:26430921

  20. Air Pressure Controlled Mass Measurement System

    NASA Astrophysics Data System (ADS)

    Zhong, Ruilin; Wang, Jian; Cai, Changqing; Yao, Hong; Ding, Jin'an; Zhang, Yue; Wang, Xiaolei

    Mass measurement is influenced by air pressure, temperature, humidity and other facts. In order to reduce the influence, mass laboratory of National Institute of Metrology, China has developed an air pressure controlled mass measurement system. In this system, an automatic mass comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the air pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the display and control part of the mass comparator are moved outside the chamber, and connected to the mass comparator by feed-throughs. Also a lifting device is designed for this system which can easily lift up the upper part of the chamber, thus weights can be easily put inside the mass comparator. The whole system is put on a marble platform, and the temperature and humidity of the laboratory is very stable. The temperature, humidity, and carbon dioxide content inside the chamber are measured in real time and can be used to get air density. Mass measurement cycle from 1100 hPa to 200 hPa and back to 1100 hPa shows the effective of the system.

  1. Expression of PCV2 antigen in the ovarian tissues of gilts

    PubMed Central

    TUMMARUK, Padet; PEARODWONG, Pachara

    2015-01-01

    The present study was performed to determine the expression of porcine circovirus type 2 (PCV2) antigen in the ovarian tissue of naturally infected gilts. Ovarian tissues were obtained from 11 culled gilts. The ovarian tissues sections were divided into two groups according to PCV2 DNA detection using PCR. PCV2 antigen was assessed in the paraffin embedded ovarian tissue sections by immunohistochemistry. A total of 2,131 ovarian follicles (i.e., 1,437 primordial, 133 primary, 353 secondary and 208 antral follicles), 66 atretic follicles and 131 corpora lutea were evaluated. It was found that PCV2 antigen was detected in 280 ovarian follicles (i.e., 239 primordial follicles, 12 primary follicles, 10 secondary follicles and 19 antral follicles), 1 atretic follicles and 3 corpora lutea (P<0.05). PCV2 antigen was detected in primordial follicles more often than in secondary follicles, atretic follicles and corpora lutea (P<0.05). The detection of PCV2 antigen was found mainly in oocytes. PCV2 antigen was found in both PCV2 DNA positive and negative ovarian tissues. It can be concluded that PCV2 antigen is expressed in all types of the ovarian follicles and corpora lutea. Further studies should be carried out to determine the influence of PCV2 on porcine ovarian function and oocyte quality. PMID:26522687

  2. Liquid ventilation.

    PubMed

    Sarkar, Suman; Paswan, Anil; Prakas, S

    2014-01-01

    Human have lungs to breathe air and they have no gills to breath liquids like fish. When the surface tension at the air-liquid interface of the lung increases as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen as the inert carrier of oxygen and carbon dioxide offers a number of advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. It is well-known that respiratory diseases are one of the most common causes of morbidity and mortality in intensive care unit. During the past few years several new modalities of treatment have been introduced. One of them and probably the most fascinating, is of LV. Partial LV, on which much of the existing research has concentrated, requires partial filling of lungs with perfluorocarbons (PFC's) and ventilation with gas tidal volumes using conventional mechanical ventilators. Various physico-chemical properties of PFC's make them the ideal media. It results in a dramatic improvement in lung compliance and oxygenation and decline in mean airway pressure and oxygen requirements. No long-term side-effect reported. PMID:25886321

  3. Effect of porcine circovirus type 2 (PCV2) infection on reproduction: disease, vertical transmission, diagnostics and vaccination.

    PubMed

    Madson, D M; Opriessnig, T

    2011-06-01

    Porcine circovirus type 2 (PCV2) causes great economic losses in growing pigs and there are several reviews on disease manifestations and lesions associated with PCV2 in growing pigs. Reproductive failure in breeding herds, predominately associated with increased numbers of mummies and non-viable piglets at parturition, is one of the disease manifestations of PCV2 infection. Boars shed low amounts of infectious PCV2 in semen for extended time periods, and vertical transmission of PCV2 to fetuses during PCV2 viremia of the dam has been experimentally confirmed. However, intrauterine-infected piglets often are clinically normal. Nevertheless, pigs infected with PCV2 by the intrauterine route can be born viremic, possibly contributing to horizontal spread of PCV2 within the breeding herd and into the nursery. Shedding of PCV2 in semen and prevalence of intrauterine-infected piglets can both be greatly reduced by PCV2 vaccination well ahead of expected PCV2 exposure. This review is a discussion on current knowledge on the effects of PCV2 infection in the dam and in in utero fetuses, including clinical signs, lesions, diagnosis and prevention through vaccination. Infection of boars with PCV2, the potential for PCV2 transmission via semen and prevention of PCV2 shedding are also discussed. PMID:21676340

  4. Blood pressure control for diabetic retinopathy

    PubMed Central

    Do, Diana V; Wang, Xue; Vedula, Satyanarayana S; Marrone, Michael; Sleilati, Gina; Hawkins, Barbara S; Frank, Robert N

    2015-01-01

    Background Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Simultaneous blood pressure control has been advocated for the same purpose, but findings reported from individual studies have supported varying conclusions regarding the ocular benefit of interventions on blood pressure. Objectives The primary aim of this review was to summarize the existing evidence regarding the effect of interventions to control or reduce blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs. A secondary aim was to compare classes of anti-hypertensive medications with respect to the same outcomes. Search methods We searched a number of electronic databases including CENTRAL as well as ongoing trial registries. We last searched the electronic databases on 25 April 2014. We also reviewed reference lists of review articles and trial reports selected for inclusion. In addition, we contacted investigators of trials with potentially pertinent data. Selection criteria We included in this review randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to intense versus less intense blood pressure control, to blood pressure control versus usual care or no intervention on blood pressure, or to different classes of anti-hypertensive agents versus placebo. Data collection and analysis Pairs of review authors independently reviewed titles and abstracts from electronic and manual searches and the full text of any document that appeared to be relevant. We assessed included trials independently for risk of bias with respect to outcomes reported in this review. We extracted data regarding trial characteristics, incidence and progression of retinopathy, visual acuity, quality of life, and cost-effectiveness at annual intervals after study entry whenever provided in published reports and other documents available from included trials. Main results We included 15 RCTs, conducted primarily in North America and Europe, that had enrolled 4157 type 1 and 9512 type 2 diabetic participants, ranging from 16 to 2130 participants in individual trials. In 10 of the 15 RCTs, one group of participants was assigned to one or more anti-hypertensive agents and the control group received placebo. In three trials, intense blood pressure control was compared to less intense blood pressure control. In the remaining two trials, blood pressure control was compared with usual care. Five of the 15 trials enrolled type 1 diabetics, and 10 trials enrolled type 2 diabetics. Six trials were sponsored entirely by pharmaceutical companies, seven trials received partial support from pharmaceutical companies, and two studies received support from government-sponsored grants and institutional support. Study designs, populations, interventions, and lengths of follow-up (range one to nine years) varied among the included trials. Overall, the quality of the evidence for individual outcomes was low to moderate. For the primary outcomes, incidence and progression of retinopathy, the quality of evidence was downgraded due to inconsistency and imprecision of estimates from individual studies and differing characteristics of participants. For primary outcomes among type 1 diabetics, one of the five trials reported incidence of retinopathy and one trial reported progression of retinopathy after 4 to 5 years of treatment and follow-up; four of the five trials reported a combined outcome of incidence and progression over the same time interval. Among type 2 diabetics, 5 of the 10 trials reported incidence of diabetic retinopathy and 3 trials reported progression of retinopathy; one of the 10 trials reported a combined outcome of incidence and progression during a 4-to 5-year follow-up period. One trial in which type 2 diabetics participated had reported no primary (or secondary) outcome targeted for this review. The evidence from these trials supported a benefit of more intensive blood pressure control intervention with respect to 4- to 5-year incidence of diabetic retinopathy (estimated risk ratio (RR) 0.80; 95% confidence interval (CI) 0.71 to 0.92) and the combined outcome of incidence and progression (estimated RR 0.78; 95% CI 0.63 to 0.97). The available evidence provided less support for a benefit with respect to 4- to 5-year progression of diabetic retinopathy (point estimate was closer to 1 than point estimates for incidence and combined incidence and progression, and the CI overlapped 1; estimated RR 0.88; 95% CI 0.73 to 1.05). The available evidence regarding progression to proliferative diabetic retinopathy or clinically significant macular edema or moderate to severe loss of best-corrected visual acuity did not support a benefit of intervention on blood pressure: estimated RRs and 95% CIs 0.95 (0.83 to 1.09) and 1.06 (0.85 to 1.33), respectively, after 4 to 5 years of follow-up. Findings within subgroups of trial participants (type 1 and type 2 diabetics; participants with normal blood pressure levels at baseline and those with elevated levels) were similar to overall findings. The adverse event reported most often (7 of 15 trials) was death, yielding an estimated RR 0.86 (95% CI 0.64 to 1.14). Hypotension was reported from three trials; the estimated RR was 2.08 (95% CI 1.68 to 2.57). Other adverse ocular events were reported from single trials. Authors’ conclusions Hypertension is a well-known risk factor for several chronic conditions in which lowering blood pressure has proven to be beneficial. The available evidence supports a beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to 4 to 5 years. However, the lack of evidence to support such intervention to slow progression of diabetic retinopathy or to prevent other outcomes considered in this review, along with the relatively modest support for the beneficial effect on incidence, weakens the conclusion regarding an overall benefit of intervening on blood pressure solely to prevent diabetic retinopathy. PMID:25637717

  5. Genetic and phylogenetic analysis of a new porcine circovirus type 2 (PCV2) strain in China.

    PubMed

    Zhang, Dan; He, Kongwang; Wen, Libin; Fan, Hongjie

    2015-12-01

    Porcine circovirus type 2 (PCV2) is the etiological agent associated with several pig diseases that are collectively referred to as porcine circovirus-associated disease (PCVAD). Unfortunately, PCV2 has had a serious economic impact on the swine industry. In this study, we report the genome sequence of a novel PCV2 isolate (JS2015) identified in pigs in Jiang Su, China. The complete DNA sequence was 1766 nucleotides long with an A+T content of 52.7%. It lacked a guanine (G) at nucleotide position 1045 compared to other reference PCV2 strains with a sequence length of 1766 nucleotides. Genetic characterization and phylogenetic analysis showed that the isolate JS2015 was most closely related to members of the PCV2d (AY181946) lineage. Our data provide insight into the epidemiology of porcine circovirus and may facilitate further study of the origin and evolution of PCV2. PMID:26395090

  6. Underwater space suit pressure control regulator

    NASA Technical Reports Server (NTRS)

    Aldrich, B. R.; Cooper, C. R.; Rasquin, J. R. (Inventor)

    1973-01-01

    A device is reported for regulating the pneumatic pressure in a ventilated space suit relative to the pressure imposed on the suit when being worn by a person underwater to simulate space environment for testing and experimentation. A box unit located on the chest area of the suit comprises connections for suit air supply and return lines and carries a regulator valve that stabilizes the air pressure differential between the inside and outside of the suit. The valve and suit pressure is controlled by the suit occupant and the valve includes a mechanism for quickly dumping the suit pressure in case of emergency. Pressure monitoring and relief devices are also included in the box unit.

  7. Ventless pressure control of cryogenic storage tanks

    NASA Astrophysics Data System (ADS)

    Barsi, Stephen

    Future operations in space exploration will require the ability to store cryogenic liquids for long durations. During storage, the tanks may self-pressurize due to heat leaks from the ambient environment. When heat leaks into the tank, the cryogenic liquid vaporizes causing the ullage pressure to rise. Being able to effectively control tank pressure will make these long duration storage concepts feasible. One way to control tank pressure involves the use of a subcooled axial liquid jet to both thermally destratify the bulk liquid and remove energy from the tank. In this dissertation, the effectiveness of using subcooled jet mixing as a pressure control scheme is analyzed by performing a small-scale experiment in a normal gravity environment with a refrigerant. Following a period of self-pressurization, the jet's speed and degree of subcooling are parametrically varied so that relevant trends can be identified. Experimental results show that mixing the bulk liquid is not sufficient to control pressure. To sustain any pressure reduction, subcooling the mixing jet is necessary. The rate of pressure reduction is greater for increased jet speeds and subcooling. Analytical and computational models were developed in order to predict the pressurization behavior. Model comparisons reveal that generally a thermodynamic model underpredicts the self-pressurization and depressurization rates. The lack of agreement is primarily attributed to the homogeneity assumption inherent in the model. To improve model predictions, a zonal model is developed which relaxes the global homogeneity assumption. Comparisons between the experimental data and the zonal model predictions are excellent for moderate to high jet flow rates. For slower jet speeds, buoyant flow in the bulk liquid adversely affects the effectiveness of a subcooled mixing jet and a more detailed computational model is required to capture this intraphase phenomena.

  8. Porcine circovirus type 2 (PCV2) enteric disease: an independent condition or part of the systemic disease?

    PubMed

    Baró, J; Segalés, J; Martínez, J

    2015-03-23

    Intestinal disorders in growing and finishing pigs have been associated with several infectious agents, including Porcine circovirus type 2 (PCV2). This virus has been mainly related with PCV2-systemic disease (PCV2-SD); nevertheless, some authors have suggested a possible restricted intestinal infection of this virus associated with enteric clinical signs. This condition has been referred as PCV2-enteric disease (PCV2-ED). The present study analysed retrospectively, from a pathological point of view, the relation between intestinal disorders and PCV2 infection in nursery and growing-finishing pigs. Among the 96 selected pigs suffering from enteric disease and submitted for necropsy between 1998 and 2011, the most prevalent enteric lesions were catarrhal enteritis/colitis (77.1%), followed by fibrinous lesions (11.5%), granulomatous inflammation (4.2%) and other lesions such as haemorrhages or ulceration (4.2%). Seventy-two pigs (75%) were positive for PCV2 by in situ hybridization (ISH). Among positive pigs for PCV2 ISH, 39 animals suffered from PCV2-SD and 33 had no lymphoid lesions but low amount of viral nucleic acid in several lymphoid tissues, therefore, these animals did not qualify for PCVD-ED. In conclusion, all animals with enteric disorders that were positive to PCV2 by ISH had evidence of viral systemic infection. These results suggest that PCV2-ED is probably a negligible condition and PCV2 mainly contributes to enteric clinical disorders in relation to PCV2-SD occurrence. PMID:25631251

  9. Ventilator-driven xenon ventilation studies

    SciTech Connect

    Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

    1984-07-01

    A modification of a common commerical Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilator rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration.

  10. Quantification of PCV2 capsid transcript in peripheral blood mononuclear cells (PBMCs) in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of PCV2 DNA or spliced capsid mRNA (Cap mRNA) for viral replication was assessed following addition of PCV2 to resting or concanavalin A (ConA) stimulated peripheral blood mononuclear cells (PBMCs). Real-time PCR or real-time RT-PCR assays were used to measure viral DNA or Cap mRNA, res...

  11. Characterization of the leukogram in PCV2 infected germ-free pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine Circovirus (PCV) is a non-enveloped, single stranded DNA virus of the Circoviridae family containing a circular genome of approximately 1.76 kb. The first isolate was recovered as a contaminant of a porcine kidney cell line in1974. This isolate, known as PCV type 1, is considered non-patho...

  12. COMPARISON OF CYTOKINE PROFILES IN PIGS SINGULARLY OR COINFECTED WITH PCV2, OR MYCOPLASMA HYOPNEUMONIAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to determine immune gene expression profiles in tracheobronchial lymph nodes (TBLN) following experimental infection with Porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae, and PCV2/M. hyopneumoniae coinfection and compare the profiles to those of uninfecte...

  13. Expression, purification and antibody preparation of PCV2 Rep and ORF3 proteins.

    PubMed

    Peng, Zhiyuan; Ma, Teng; Pang, Daxin; Su, Dan; Chen, Fuwang; Chen, Xinrong; Guo, Ning; Ouyang, Ting; Ouyang, Hongsheng; Ren, Linzhu

    2016-05-01

    Rep and ORF3 proteins are important functional proteins of porcine circovirus 2 (PCV2). Here, Rep and ORF3 genes were cloned, expressed and used to raise polyclonal antibodies. The result showed the recombinant plasmids of Rep and ORF3 genes constructed in this study were expressed efficiently in the prokaryotic system, and the recombinant proteins had antigenicity and immunogenicity. Furthermore, reactivity and specificity of the antiserums were characterized by western blot and indirect immunofluorescent assays. The results elucidated that polyclonal antiserum prepared with Rep or ORF3 had good reactivity and specificity against PCV2, or the Rep and ORF3 expressed in PK-15 cells, respectively. The Rep protein is promising for PCV2 antibody and vaccine development. These results will be helpful for further studies focusing on pathogenesis of PCV2 and serology diagnostic test or vaccine development against PCV2. PMID:26812108

  14. Oral application of freeze-dried yeast particles expressing the PCV2b Cap protein on their surface induce protection to subsequent PCV2b challenge in vivo.

    PubMed

    Patterson, Robert; Eley, Thomas; Browne, Christopher; Martineau, Henny M; Werling, Dirk

    2015-11-17

    Porcine circovirus type 2 (PCV2) is now endemic in every major pig producing country, causing PCV-associated disease (PCVAD), linked with large scale economic losses. Current vaccination strategies are based on the capsid protein of the virus and are reasonably successful in preventing PCVAD but fail to induce sterile immunity. Additionally, vaccinating whole herds is expensive and time consuming. In the present study a "proof of concept" vaccine trial was employed to test the effectiveness of powdered freeze-dried recombinant Saccharomyces cerevisiae yeast stably expressing the capsid protein of PCV2b on its surface as an orally applied vaccine. PCV2-free pigs were given 3 doses of vaccine or left un-vaccinated before challenge with a defined PCV2b strain. Rectal temperatures were measured and serum and faeces samples were collected weekly. At the end of the study, pigs were euthanized, tissue samples taken and tested for PCV2b load by qPCR and immunohistochemistry. The peak of viraemia in sera and faeces of unvaccinated pigs was higher than that of vaccinated pigs. Additionally more sIgA was found in faeces of vaccinated pigs than unvaccinated. Vaccination was associated with lower serum concentrations of TNFα and IL-1β but higher concentrations of IFNα and IFNγ in comparison to the unvaccinated animals. At the end of the trial, a higher viral load was found in several lymphatic tissues and the ileum of unvaccinated pigs in comparison to vaccinated pigs. The difference between groups was especially apparent in the ileum. The results presented here demonstrate a possible use for recombinant S. cerevisiae expressing viral proteins as an oral vaccine against PCV2. A powdered freeze-dried recombinant S. cerevisiae used as an oral vaccine could be mixed with feed and may offer a cheap and less labour intensive alternative to inoculation with the additional advantage that no cooling chain would be required for vaccine transport and storage. PMID:26476879

  15. Oral application of freeze-dried yeast particles expressing the PCV2b Cap protein on their surface induce protection to subsequent PCV2b challenge in vivo

    PubMed Central

    Patterson, Robert; Eley, Thomas; Browne, Christopher; Martineau, Henny M.; Werling, Dirk

    2015-01-01

    Porcine circovirus type 2 (PCV2) is now endemic in every major pig producing country, causing PCV-associated disease (PCVAD), linked with large scale economic losses. Current vaccination strategies are based on the capsid protein of the virus and are reasonably successful in preventing PCVAD but fail to induce sterile immunity. Additionally, vaccinating whole herds is expensive and time consuming. In the present study a “proof of concept” vaccine trial was employed to test the effectiveness of powdered freeze-dried recombinant Saccharomyces cerevisiae yeast stably expressing the capsid protein of PCV2b on its surface as an orally applied vaccine. PCV2-free pigs were given 3 doses of vaccine or left un-vaccinated before challenge with a defined PCV2b strain. Rectal temperatures were measured and serum and faeces samples were collected weekly. At the end of the study, pigs were euthanized, tissue samples taken and tested for PCV2b load by qPCR and immunohistochemistry. The peak of viraemia in sera and faeces of unvaccinated pigs was higher than that of vaccinated pigs. Additionally more sIgA was found in faeces of vaccinated pigs than unvaccinated. Vaccination was associated with lower serum concentrations of TNFα and IL-1β but higher concentrations of IFNα and IFNγ in comparison to the unvaccinated animals. At the end of the trial, a higher viral load was found in several lymphatic tissues and the ileum of unvaccinated pigs in comparison to vaccinated pigs. The difference between groups was especially apparent in the ileum. The results presented here demonstrate a possible use for recombinant S. cerevisiae expressing viral proteins as an oral vaccine against PCV2. A powdered freeze-dried recombinant S. cerevisiae used as an oral vaccine could be mixed with feed and may offer a cheap and less labour intensive alternative to inoculation with the additional advantage that no cooling chain would be required for vaccine transport and storage. PMID:26476879

  16. Quantification of PCV2 capsid transcript in peripheral blood mononuclear cells (PBMCs) in vitro.

    PubMed

    Yu, S; Vincent, A; Opriessnig, T; Carpenter, S; Kitikoon, P; Halbur, P G; Thacker, E

    2007-07-20

    The presence of PCV2 DNA or spliced capsid mRNA (Cap mRNA) for viral replication was assessed following addition of PCV2 to resting or concanavalin A (ConA) stimulated peripheral blood mononuclear cells (PBMCs). Real-time PCR or real-time RT-PCR assays were used to measure viral DNA or Cap mRNA, respectively. The study demonstrated that PCV2 replication increased in infected PBMCs over time. Replication within infected PBMCs was significantly (P<0.05) increased when PBMCs were stimulated with ConA, compared to unstimulated PBMCs. The data showed a strong correlation between the level of PCV2 Cap mRNA and the level of viral DNA in the ConA stimulated PBMCs. Replication of PCV2 was also assessed in T lymphocyte- and monocyte/macrophage-enriched or monocyte/macrophage-depleted PBMC populations which had been stimulated with ConA for 3 days. It was demonstrated that the enriched T lymphocytes and the monocyte/macrophage-depleted PBMCs had significantly higher Cap mRNA and viral DNA levels (P<0.05) compared to the monocyte/macrophage-enriched population, indicating that in addition to monocytes/macrophages, PCV2 replicates in lymphocytes, particularly T lymphocytes following stimulation. These results suggest that the presence of activated T lymphocytes may play an important role in PCV2 replication and potentially the development of clinical disease. PMID:17418508

  17. Ventilator-driven xenon ventilation studies

    SciTech Connect

    Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

    1984-07-01

    A modification of a common commercial Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilatory rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration.

  18. Pressure versus volume controlled modes in invasive mechanical ventilation.

    PubMed

    Garnero, A J; Abbona, H; Gordo-Vidal, F; Hermosa-Gelbard, C

    2013-05-01

    The first generation of mechanical ventilators were controlled and cycled by pressure. Unfortunately, they did not allow control of the delivered tidal volume under changes in the dynamics of the respiratory system. This led to a second generation of ventilators that allowed volume control, hence favoring the ventilatory strategy based on normalization of the arterial gases. Studies conducted in the 1980s which related lung injury to the high ventilator pressures utilized while treating acute respiratory distress syndrome patients renewed interest in pressure-controlled mechanical ventilation. In addition, new evidence became available, leading to the development of pulmonary protective strategies aiming at preventing the progression of ventilator-induced lung injury. This review provides a detailed description of the control of pressure or volume using certain ventilatory modes, and offers a general view of their advantages and disadvantages, based on the latest available evidence. PMID:23260264

  19. Glutamine starvation enhances PCV2 replication via the phosphorylation of p38 MAPK, as promoted by reducing glutathione levels.

    PubMed

    Chen, Xingxiang; Shi, Xiuli; Gan, Fang; Huang, Da; Huang, Kehe

    2015-01-01

    Glutamine has a positive effect on ameliorating reproductive failure caused by porcine circovirus type 2 (PCV2). However, the mechanism by which glutamine affects PCV2 replication remains unclear. This study was conducted to investigate the effects of glutamine on PCV2 replication and its underlying mechanisms in vitro. The results show that glutamine promoted PK-15 cell viability. Surprisingly, glutamine starvation significantly increased PCV2 replication. The promotion of PCV2 replication by glutamine starvation disappeared after fresh media with 4 mM glutamine was added. Likewise, promotion of PCV2 was observed after adding buthionine sulfoximine (BSO). Glutamine starvation or BSO treatment increased the level of p38 MAPK phosphorylation and PCV2 replication in PK-15 cells. Meanwhile, p38 MAPK phosphorylation and PCV2 replication significantly decreased in p38-knockdown PK-15 cells. Promotion of PCV2 replication caused by glutamine starvation could be blocked in p38-knockdown PK-15 cells. Therefore, glutamine starvation increased PCV2 replication by promoting p38 MAPK activation, which was associated with the down regulation of intracellular glutathione levels. Our findings may contribute toward interpreting the possible pathogenic mechanism of PCV2 and provide a theoretical reference for application of glutamine in controlling porcine circovirus-associated diseases. PMID:25879878

  20. 112. REFRIGERANT CONDENSER TANKS AND PRESSURE CONTROLS IN NORTHEAST CORNER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    112. REFRIGERANT CONDENSER TANKS AND PRESSURE CONTROLS IN NORTHEAST CORNER OF MECHANICAL EQUIPMENT ROOM (201), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  1. Immunogenicity of bacteriophage lambda particles displaying porcine Circovirus 2 (PCV2) capsid protein epitopes.

    PubMed

    Gamage, Lakshman N A; Ellis, John; Hayes, Sidney

    2009-11-01

    Phage lambda particles displaying four immunodominant regions of porcine Circovirus 2 (PCV2) capsid protein (LDP-D-CAP) was shown to be immunogenic in pigs. The immunodominant regions were fused to the carboxyl-terminal of lambda head protein D. Expression of D-CAP on lambda display particles was demonstrated by ELISA and Western blots. Pigs receiving LDP-D-CAP, without incorporating adjuvant, showed significant anti-PCV2 immune response following the primary vaccination. The LDP-D-CAP preparation induced PCV2 neutralizing antibodies. Delayed type hypersensitivity (DTH) reaction scores revealed that the immunized pigs were hypersensitive to both lambda phage and PCV2 antigens. The LDP-D-CAP elicited both cellular and humoral immune responses. Neither LDP-D-CAP nor the lambda control elicited any untoward local or systemic reactions following immunization. These studies produced the first potential phage vaccine to porcine Circovirus 2. PMID:19712770

  2. VENTILATION NEEDS DURING CONSTRUCTION

    SciTech Connect

    C.R. Gorrell

    1998-07-23

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options.

  3. The growing role of noninvasive ventilation in patients requiring prolonged mechanical ventilation.

    PubMed

    Hess, Dean R

    2012-06-01

    For many patients with chronic respiratory failure requiring ventilator support, noninvasive ventilation (NIV) is preferable to invasive support by tracheostomy. Currently available evidence does not support the use of nocturnal NIV in unselected patients with stable COPD. Several European studies have reported benefit for high intensity NIV, in which setting of inspiratory pressure and respiratory rate are selected to achieve normocapnia. There have also been studies reporting benefit for the use of NIV as an adjunct to exercise training. NIV may be useful as an adjunct to airway clearance techniques in patients with cystic fibrosis. Accumulating evidence supports the use of NIV in patients with obesity hypoventilation syndrome. There is considerable observational evidence supporting the use of NIV in patients with chronic respiratory failure related to neuromuscular disease, and one randomized controlled trial reported that the use of NIV was life-prolonging in patients with amyotrophic lateral sclerosis. A variety of interfaces can be used to provide NIV in patients with stable chronic respiratory failure. The mouthpiece is an interface that is unique in this patient population, and has been used with success in patients with neuromuscular disease. Bi-level pressure ventilators are commonly used for NIV, although there are now a new generation of intermediate ventilators that are portable, have a long battery life, and can be used for NIV and invasive applications. Pressure support ventilation, pressure controlled ventilation, and volume controlled ventilation have been used successfully for chronic applications of NIV. New modes have recently become available, but their benefits await evidence to support their widespread use. The success of NIV in a given patient population depends on selection of an appropriate patient, selection of an appropriate interface, selection of an appropriate ventilator and ventilator settings, the skills of the clinician, the motivation of the patient, and the support of the family. PMID:22663966

  4. A system for high-frequency oscillatory ventilation and intermittent mandatory ventilation in neonates.

    PubMed

    Kopotic, R J; Mannino, F L; Boynton, B R

    1986-07-01

    We combined high-frequency oscillatory ventilation and intermittent mandatory ventilation, using a system composed of an Emerson airway vibrator, a Babybird 1 ventilator, and rate/pressure monitors. The Emerson device, a modified air compressor with rate controller, oscillated a small volume of gas at the airway. This device was coupled to the bird unit through a circuit of our design. Humidified fresh gas and pressure-relief valves were provided by the bird ventilator, and mean airway pressure was adjusted by its expiratory-limb venturi device or by the end-expiratory pressure control. The volume of gas delivered by the oscillator to various sites was measured with a plethysmograph tuned to high frequencies. At frequencies of 20 to 30 Hz, a 27-ml volume from the oscillator decreased to between 7 and 14 ml at the proximal airway, and to between 0.1 and 2.3 ml at the distal tip of the endotracheal tube. The magnitude of this decrease depended on the size of the endotracheal tube, the circuit resistance of the ventilator, oscillation frequency, and the position of the oscillator's expansion-chamber valve. We have used this system for over 3 yr to ventilate sick neonates safely and effectively. PMID:3459633

  5. International trades, local spread and viral evolution: the case of porcine circovirus type 2 (PCV2) strains heterogeneity in Italy.

    PubMed

    Franzo, Giovanni; Tucciarone, Claudia M; Dotto, Giorgia; Gigli, Alessandra; Ceglie, Letizia; Drigo, Michele

    2015-06-01

    Porcine circovirus type 2 is one of the most widespread and economically relevant infections of swine. Four genotypes have been recognized, but currently, only three (PCV2a, PCV2b and PCV2d) are effectively circulating. The widespread livestock trade and rapid viral evolution have contributed to determining the high heterogeneity of PCV2 and the dispersal of potentially more virulent strains. Italian swine farming and the related processing industry are relevant in the national economy. Despite the noteworthy losses associated with direct and control measure costs, no data are currently available on the molecular epidemiology of PCV2 in Italy. Our study, which was intended to fill this gap, considered 75 completed genome PCV2 sequences, which were obtained from samples collected from the highly densely populated area of Northern Italy between 2007 and 2014. Phylogenetic analysis and comparison with reference sequences demonstrated the co-circulation, with different prevalences, of PCV2a, PCV2b and PCV2d within the national borders, with PCV2b being the most prevalent. Recombination between different genotypes was also proven to be frequent. Phylogeographic analysis demonstrated that the marked variability of Italian PCV2 strains can be attributable to multiple introduction events. The comparison of the phylogenetic analysis results, the location of different haplotypes and the international commercial routs of live pigs allow the speculation of several links as well as the role of Italy as both an importer and exporter of PCV2 haplotypes, mainly from and to European and Asian countries. A similarly intricate contact network was demonstrated within national borders, with different haplotypes being detected in the same province and different provinces harbouring the same haplotype. Overall, this paper represents the first description of PCV2 in Italy and demonstrates that the high variability of circulating Italian strains is due to multiple introduction events, wide circulation within national boundaries and rapid viral evolution. PMID:25858118

  6. Identification of microRNAs in PCV2 subclinically infected pigs by high throughput sequencing.

    PubMed

    Núñez-Hernández, Fernando; Pérez, Lester J; Muñoz, Marta; Vera, Gonzalo; Tomás, Anna; Egea, Raquel; Córdoba, Sarai; Segalés, Joaquim; Sánchez, Armand; Núñez, José I

    2015-01-01

    Porcine circovirus type 2 (PCV2) is the essential etiological infectious agent of PCV2-systemic disease and has been associated with other swine diseases, all of them collectively known as porcine circovirus diseases. MicroRNAs (miRNAs) are a new class of small non-coding RNAs that regulate gene expression post-transcriptionally. miRNAs play an increasing role in many biological processes. The study of miRNA-mediated host-pathogen interactions has emerged in the last decade due to the important role that miRNAs play in antiviral defense. The objective of this study was to identify the miRNA expression pattern in PCV2 subclinically infected and non-infected pigs. For this purpose an experimental PCV2 infection was carried out and small-RNA libraries were constructed from tonsil and mediastinal lymph node (MLN) of infected and non-infected pigs. High throughput sequencing determined differences in miRNA expression in MLN between infected and non-infected while, in tonsil, a very conserved pattern was observed. In MLN, miRNA 126-3p, miRNA 126-5p, let-7d-3p, mir-129a and mir-let-7b-3p were up-regulated whereas mir-193a-5p, mir-574-5p and mir-34a down-regulated. Prediction of functional analysis showed that these miRNAs can be involved in pathways related to immune system and in processes related to the pathogenesis of PCV2, although functional assays are needed to support these predictions. This is the first study on miRNA gene expression in pigs infected with PCV2 using a high throughput sequencing approach in which several host miRNAs were differentially expressed in response to PCV2 infection. PMID:25879589

  7. Emerging non-PCV13 serotypes of noninvasive Streptococcus pneumoniae with macrolide resistance genes in northern Japan

    PubMed Central

    Kawaguchiya, M.; Urushibara, N.; Aung, M.S.; Morimoto, S.; Ito, M.; Kudo, K.; Sumi, A.; Kobayashi, N.

    2015-01-01

    In Japan, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced to the nation's routine immunization program in April 2013 and was replaced by the 13-valent pneumococcal conjugate vaccine (PCV13) in November 2013. Distribution of serotypes and macrolide resistance genotypes was investigated for a total of 1097 (975 children, 122 adults) and 960 (873 children, 87 adults) clinical isolates of Streptococcus pneumoniae from noninvasive infections in Hokkaido (northern main island of Japan) in the routine immunization periods for PCV7 and PCV13 (April–October 2013 and November 2013–November 2014, respectively). Serotype was determined by sequential multiplex PCR and additional genetic analyses. Macrolide resistance genes erm(B) and mef(A/E) were detected by multiplex PCR. Although the most prevalent serotypes in children were 23A and 6C in the PCV7 period, after replacement with PCV13, 19A became the most common, followed by 6C, 15A and 23A. Among adults, serotype 3 was consistently the most frequent throughout the study periods. Compared with values from the pre-PCV7 routine immunization period, PCV7 serotypes decreased from 48.3 to 3.3% in the PCV13 period among children, while the rates of non-PCV13 serotypes (particularly 15A, 23A, 11A, 10A and 35B) increased from 39.7 to 75.1% (p < 0.001). In the PCV13 period, erm(B), mef(A/E) and both of these genes were detected in 75.8, 31.6 and 11.3% of all isolates, respectively. Serotype 19A accounted for 76.9% of the isolates with both the macrolide resistance genes, and emerging non-PCV13 serotypes 15A, 15C and 23A mostly harboured erm(B). PMID:26909157

  8. Emerging non-PCV13 serotypes of noninvasive Streptococcus pneumoniae with macrolide resistance genes in northern Japan.

    PubMed

    Kawaguchiya, M; Urushibara, N; Aung, M S; Morimoto, S; Ito, M; Kudo, K; Sumi, A; Kobayashi, N

    2016-01-01

    In Japan, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced to the nation's routine immunization program in April 2013 and was replaced by the 13-valent pneumococcal conjugate vaccine (PCV13) in November 2013. Distribution of serotypes and macrolide resistance genotypes was investigated for a total of 1097 (975 children, 122 adults) and 960 (873 children, 87 adults) clinical isolates of Streptococcus pneumoniae from noninvasive infections in Hokkaido (northern main island of Japan) in the routine immunization periods for PCV7 and PCV13 (April-October 2013 and November 2013-November 2014, respectively). Serotype was determined by sequential multiplex PCR and additional genetic analyses. Macrolide resistance genes erm(B) and mef(A/E) were detected by multiplex PCR. Although the most prevalent serotypes in children were 23A and 6C in the PCV7 period, after replacement with PCV13, 19A became the most common, followed by 6C, 15A and 23A. Among adults, serotype 3 was consistently the most frequent throughout the study periods. Compared with values from the pre-PCV7 routine immunization period, PCV7 serotypes decreased from 48.3 to 3.3% in the PCV13 period among children, while the rates of non-PCV13 serotypes (particularly 15A, 23A, 11A, 10A and 35B) increased from 39.7 to 75.1% (p < 0.001). In the PCV13 period, erm(B), mef(A/E) and both of these genes were detected in 75.8, 31.6 and 11.3% of all isolates, respectively. Serotype 19A accounted for 76.9% of the isolates with both the macrolide resistance genes, and emerging non-PCV13 serotypes 15A, 15C and 23A mostly harboured erm(B). PMID:26909157

  9. Genetic variability of porcine circovirus 2 (PCV2) field isolates from vaccinated and non-vaccinated pig herds in Germany.

    PubMed

    Reiner, Gerald; Hofmeister, Regina; Willems, Hermann

    2015-10-22

    Porcine circovirus 2 (PCV2) is responsible for a wide range of associated diseases (PCVD) affecting swine production worldwide. Highly efficient commercial vaccines induce protective immunity, but PCV2 is still circulating in vaccinated farms. Thus, and because of the viruś high mutation rate, recent findings provide concerns about PCV2 strains capable to escape vaccination. Based on 2156 samples from individual pigs of 315 herds from Germany we describe a high effectivity of vaccination between 2008 and the third quarter of 2011. In this period, virus load dropped continuously and at the end of this period it hardly reached the limit of quantification. Thereafter, virus loads re-increased, although most of the herds were still vaccinated. Sixty-two randomly selected samples from vaccinated (n=28) and non-vaccinated (n=26) herds between 2008 and 2012 were completely sequenced. As compared to the PCV2b reference sequence 259 polymorphisms were detected. Polymorhisms were analysed for associations to vaccination status, genotype (PCV2a/PCV2b), and virus load. PCV2a sequences were significantly repelled by PCV2b. One SNP at position 1182 (g.1182G>T), involved in capsid epitope formation, was significantly associated with the PCV2 genotype (2a/2b). Moreover, this SNP was affected by vaccination, with effects on allele frequencies and viral load, independent from the PCV2 genotype (2a/2b). We conclude that there is indeed evidence for a selectional impact of vaccination on the PCV2 sequence, especially on nucleotides involved in epitope formation. Such variation might be responsible for the observed re-increase of PCV2-loads in samples from the end of 2011 in Germany. PMID:26275852

  10. Home Ventilator Guide

    MedlinePlus

    ... to have a backup battery or even a generator readily available in case of power outages or ... ventilation, in which case a backup ventilator and generator are prudent. Practicing regular safety drills helps prepare ...

  11. VENTILATION MODEL REPORT

    SciTech Connect

    V. Chipman

    2002-10-31

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses.

  12. 142. STANDBY PRESSURE CONTROL UNIT FOR FUEL AND LIQUID OXYGEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    142. STANDBY PRESSURE CONTROL UNIT FOR FUEL AND LIQUID OXYGEN IN SOUTHWEST PORTION OF CONTROL ROOM (214), LSB (BLDG. 751), FACING WEST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  13. VENTILATION TECHNOLOGY SYSTEMS ANALYSIS

    EPA Science Inventory

    The report gives results of a project to develop a systems analysis of ventilation technology and provide a state-of-the-art assessment of ventilation and indoor air quality (IAQ) research needs. (NOTE: Ventilation technology is defined as the hardware necessary to bring outdoor ...

  14. Neurally adjusted ventilator assist in very low birth weight infants: Current status.

    PubMed

    Narchi, Hassib; Chedid, Fares

    2015-06-26

    Continuous improvements in perinatal care have resulted in increased survival of premature infants. Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease (CLD) or bronchopulmonary dysplasia. Strategies to minimize the risk of lung injury have been developed and include improved antenatal management (education, regionalization, steroids, and antibiotics), exogenous surfactant administration and reduction of barotrauma by using exclusive or early noninvasive ventilatory support. The most frequently used mode of assisted ventilation is pressure support ventilation that may lead to patient-ventilator asynchrony that is associated with poor outcome. Ventilator-induced diaphragmatic dysfunction or disuse atrophy of diaphragm fibers may also occur. This has led to the development of new ventilation modes including neurally adjusted ventilatory assist (NAVA). This ventilation mode is controlled by electrodes embedded within a nasogastric catheter which detect the electrical diaphragmatic activity (Edi) and transmit it to trigger the ventilator in synchrony with the patient's own respiratory efforts. This permits the patient to control peak inspiratory pressure, mean airway pressure and tidal volume. Back up pressure control (PC) is provided when there is no Edi signal and no pneumatic trigger. Compared with standard conventional ventilation, NAVA improves blood gas regulation with lower peak inspiratory pressure and oxygen requirements in preterm infants. NAVA is safe mode of ventilation. The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage, pneumothorax, or necrotizing enterocolitis when compared to conventional ventilation. Future large size randomized controlled trials should be established to compare NAVA with volume targeted and pressure controlled ventilation in newborns with mature respiratory drive. Most previous studies and trials were not sufficiently large and did not include long-term patient oriented outcomes. Multicenter, randomized, outcome trials are needed to determine whether NAVA is effective in avoiding intubation, facilitating extubation, decreasing time of ventilation, reducing the incidence of CLD, decreasing length of stay, and improving long-term outcomes such as the duration of ventilation, length of hospital stay, rate of pneumothorax, CLD and other major complications of prematurity. In order to prevent barotrauma, next generations of NAVA equipment for neonatal use should enable automatic setting of ventilator parameters in the backup PC mode based on the values generated by NAVA. They should also include an upper limit to the inspiratory time as in conventional ventilation. The manufacturers of Edi catheters should produce smaller sizes available for extreme low birth weight infants. Newly developed ventilators should also include leak compensation and high frequency ventilation. A peripheral flow sensor is also essential to the proper delivery of all modes of conventional ventilation as well as NAVA. PMID:26140273

  15. Neurally adjusted ventilator assist in very low birth weight infants: Current status

    PubMed Central

    Narchi, Hassib; Chedid, Fares

    2015-01-01

    Continuous improvements in perinatal care have resulted in increased survival of premature infants. Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease (CLD) or bronchopulmonary dysplasia. Strategies to minimize the risk of lung injury have been developed and include improved antenatal management (education, regionalization, steroids, and antibiotics), exogenous surfactant administration and reduction of barotrauma by using exclusive or early noninvasive ventilatory support. The most frequently used mode of assisted ventilation is pressure support ventilation that may lead to patient-ventilator asynchrony that is associated with poor outcome. Ventilator-induced diaphragmatic dysfunction or disuse atrophy of diaphragm fibers may also occur. This has led to the development of new ventilation modes including neurally adjusted ventilatory assist (NAVA). This ventilation mode is controlled by electrodes embedded within a nasogastric catheter which detect the electrical diaphragmatic activity (Edi) and transmit it to trigger the ventilator in synchrony with the patient’s own respiratory efforts. This permits the patient to control peak inspiratory pressure, mean airway pressure and tidal volume. Back up pressure control (PC) is provided when there is no Edi signal and no pneumatic trigger. Compared with standard conventional ventilation, NAVA improves blood gas regulation with lower peak inspiratory pressure and oxygen requirements in preterm infants. NAVA is safe mode of ventilation. The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage, pneumothorax, or necrotizing enterocolitis when compared to conventional ventilation. Future large size randomized controlled trials should be established to compare NAVA with volume targeted and pressure controlled ventilation in newborns with mature respiratory drive. Most previous studies and trials were not sufficiently large and did not include long-term patient oriented outcomes. Multicenter, randomized, outcome trials are needed to determine whether NAVA is effective in avoiding intubation, facilitating extubation, decreasing time of ventilation, reducing the incidence of CLD, decreasing length of stay, and improving long-term outcomes such as the duration of ventilation, length of hospital stay, rate of pneumothorax, CLD and other major complications of prematurity. In order to prevent barotrauma, next generations of NAVA equipment for neonatal use should enable automatic setting of ventilator parameters in the backup PC mode based on the values generated by NAVA. They should also include an upper limit to the inspiratory time as in conventional ventilation. The manufacturers of Edi catheters should produce smaller sizes available for extreme low birth weight infants. Newly developed ventilators should also include leak compensation and high frequency ventilation. A peripheral flow sensor is also essential to the proper delivery of all modes of conventional ventilation as well as NAVA. PMID:26140273

  16. The enhanced immune response of PCV-2 vaccine using Rehmannia glutinosa polysaccharide liposome as an adjuvant.

    PubMed

    Huang, Yee; Liu, Zhenguang; Bo, Ruonan; Xing, Jie; Luo, Li; Zhen, Sisi; Niu, Yale; Hu, Yuanliang; Liu, Jiaguo; Wu, Yi; Wang, Deyun

    2016-05-01

    Liposomes, one kind of vaccine adjuvants, have been demonstrated as effective adjuvants and vaccine delivery system. Immunization against PCV-2 has been studied intensely and found to be the most effective strategy for protecting pigs against PCV-2 infection. Inactivated vaccines represent a complex mixture of viral antigens closely resembling the native virion. In the present study, PCV-2 attenuated antigen was encapsulated within Rehmannia glutinosa polysaccharide liposome, instead of oil adjuvant which is the mainstream adjuvant. Our results showed that RGPL could elicit a strong IgG response and significantly increased the production of Th1 and Th2 associated IgG subtypes and cytokines. R. glutinosa polysaccharide liposome showed excellent particle stability. In vitro, R. glutinosa polysaccharide liposome could also significantly promote phagocytic activity of macrophage and the levels of cytokines it produced. Overall, the results demonstrated that R. glutinosa polysaccharide liposome has the potential to be developed into a more effective and safer vaccine adjuvant. PMID:26851361

  17. DEMAND CONTROLLED VENTILATION AND CLASSROOM VENTILATION

    SciTech Connect

    Fisk, William J.; Mendell, Mark J.; Davies, Molly; Eliseeva, Ekaterina; Faulkner, David; Hong, Tienzen; Sullivan, Douglas P.

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling. Major findings included: ? The single-location carbon dioxide sensors widely used for demand controlled ventilation frequently have large errors and will fail to effectively control ventilation rates (VRs).? Multi-location carbon dioxide measurement systems with more expensive sensors connected to multi-location sampling systems may measure carbon dioxide more accurately.? Currently-available optical people counting systems work well much of the time but have large counting errors in some situations. ? In meeting rooms, measurements of carbon dioxide at return-air grilles appear to be a better choice than wall-mounted sensors.? In California, demand controlled ventilation in general office spaces is projected to save significant energy and be cost effective only if typical VRs without demand controlled ventilation are very high relative to VRs in codes. Based on the research, several recommendations were developed for demand controlled ventilation specifications in the California Title 24 Building Energy Efficiency Standards.The research on classroom ventilation collected data over two years on California elementary school classrooms to investigate associations between VRs and student illness absence (IA). Major findings included: ? Median classroom VRs in all studied climate zones were below the California guideline, and 40percent lower in portable than permanent buildings.? Overall, one additional L/s per person of VR was associated with 1.6percent less IA. ? Increasing average VRs in California K-12 classrooms from the current average to the required level is estimated to decrease IA by 3.4percent, increasing State attendance-based funding to school districts by $33M, with $6.2 M in increased energy costs. Further VR increases would provide additional benefits.? Confirming these findings in intervention studies is recommended. ? Energy costs of heating/cooling unoccupied classrooms statewide are modest, but a large portion occurs in relatively few classrooms.

  18. Tank Pressure Control Experiment - A low-g mixing investigation

    NASA Technical Reports Server (NTRS)

    Bentz, M. D.; Meserole, J. S.; Knoll, R. L.

    1990-01-01

    The Tank Pressure Control Experiment (TPCE) was conceived to meet the need for an aspect of cryogenic fluid management technology that is critical to several future national space missions: control of cryogenic storage tank pressures by active mixing. In-space testing is the only means of obtaining the fluid dynamic data necessary to develop and test predictive models of mixing. These models, when validated, will allow future cryogenic systems to be designed with more efficient and reliable pressure control systems. The objectives of the TPCE project are to characterize the fluid dynamics of jet-induced mixing in low gravity, evaluate the validity of empirical models and correlations, and provide data for use in developing and validating computational fluid dynamic models. This paper discusses prior studies of low-g mixing, the objectives and benefits of TPCE, the design and status of the payload, and preliminary results obtained from low-g aircraft testing.

  19. Tank Pressure Control Experiment/thermal Phenomena (TPCE/TP)

    NASA Technical Reports Server (NTRS)

    Hasan, M. M.; Knoll, R. H.

    1992-01-01

    The 'Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP)' is a reflight of the tank pressure control experiment (TPCE), flown on STS-43 in a standard Get-Away Special (GAS) container in August 1991. The TPCE obtained extensive video and digital data of the jet induced mixing process in a partially filled tank in low gravity environments. It also provided limited data on the thermal processes involved. The primary objective of the reflight of TPCE is to investigate experimentally the phenomena of liquid superheating and pool nucleate boiling at very low heat fluxes in a long duration low gravity environment. The findings of this experiment will be of direct relevance to space based subcritical cryogenic fluid system design and operation. Experiment hardware and results from the first TPCE are described in outline and graphic form.

  20. Investigation and validation of the role of a QTL on SSC12 in PCV2b viremia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine circovirus type 2 (PCV2) is known to modulate immune response leading to a susceptibility to Porcine Circovirus Associated Diseases (PCVAD) with an impact on growth and mortality. Our previous GWAS of PCV2b experimentally infected pigs uncovered two QTL that explain 14% of the genetic variat...

  1. Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks

    NASA Technical Reports Server (NTRS)

    Lopez, Alfredo; Grayson, Gary D.; Chandler, Frank O.; Hastings, Leon J.; Heyadat, Ali

    2007-01-01

    A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in normal gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-31) software. Quantitative model validation is ,provided by engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage_ Technology Demonstrator (STUSTD) program. The engineering checkout tests provide cryogenic tank self-pressurization test data at various heat leaks and tank fill levels. The predicted self-pressurization rates, ullage and liquid temperatures at discrete locations within the STUSTD tank are in good agreement with test data. The work presented here advances current CFD modeling capabilities for cryogenic pressure control and helps develop a low cost CFD-based design process for space hardware.

  2. A noninvasive high frequency oscillation ventilator: Achieved by utilizing a blower and a valve

    NASA Astrophysics Data System (ADS)

    Yuan, YueYang; Sun, JianGuo; Wang, Baicun; Feng, Pei; Yang, ChongChang

    2016-02-01

    After the High Frequency Oscillatory Ventilation (HFOV) has been applied in the invasive ventilator, the new technique of noninvasive High Frequency Oscillatory Ventilation (nHFOV) which does not require opening the patient's airway has attracted much attention from the field. This paper proposes the design of an experimental positive pressure-controlled nHFOV ventilator which utilizes a blower and a special valve and has three ventilation modes: spontaneous controlled ventilation combining HFOV, time-cycled ventilation combining HFOV (T-HFOV), and continuous positive airway pressure ventilation combining HFOV. Experiments on respiratory model are conducted and demonstrated the feasibility of using nHFOV through the control of fan and valve. The experimental ventilator is able to produce an air flow with small tidal volume (VT) and a large minute ventilation volume (MV) using regular breath tubes and nasal mask (e.g., under T-HFOV mode, with a maximum tidal volume of 100 ml, the minute ventilation volume reached 14 400 ml). In the process of transmission, there is only a minor loss of oscillation pressure. (Under experimental condition and with an oscillation frequency of 2-10 Hz, peak pressure loss was around 0%-50% when it reaches the mask.)

  3. Ventilation Model Report

    SciTech Connect

    V. Chipman; J. Case

    2002-12-20

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. Revision 01 ICN 01 included the results of the unqualified software code MULTIFLUX to assess the influence of moisture on the ventilation efficiency. The purposes of Revision 02 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to initialize post-closure thermal models (Section 6.6). (3) To satisfy the remainder of KTI agreement TEF 2.07 (Reamer and Williams 2001b). Specifically to provide the results of post-test ANSYS modeling of the Atlas Facility forced convection tests (Section 7.1.2). This portion of the model report also serves as a validation exercise per AP-SIII.10Q, Models, for the ANSYS ventilation model. (4) To asses the impacts of moisture on the ventilation efficiency.

  4. Mortality in pigs given PCV2 virus derived from DNA clones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The clinical presentation following infection with porcine circovirus type 2 (PCV2) ranges from sub-clinical to one of several disease states known collectively as porcine circovirus diseases (PCVD). In 2005 a disease spread rapidly through finishing barns in the U. S. that was recognized as an acut...

  5. Optimization on Preparation Conditions of Salidroside Liposome and Its Immunological Activity on PCV-2 in Mice

    PubMed Central

    Feng, Yibo; Zhao, Xiaojuan; Lv, Fang; Zhang, Jinqiu; Deng, Bihua; Zhao, Yanhong; Hu, Yuanliang; Wang, Deyun; Liu, Jiaguo; Lu, Yu; Bo, Ruonan; Liu, Zhenguang

    2015-01-01

    The aim of this study was to optimize the preparation conditions of salidroside liposome with high encapsulation efficiency (EE) and to study the immunological enhancement activity of salidroside liposome as porcine circovirus type 2 virus (PCV-2) vaccine adjuvant. Response surface methodology (RSM) was selected to optimize the conditions for the preparation of salidroside liposome using Design-Expert V8.0.6 software. Three kinds of salidroside liposome adjuvants were prepared to study their adjuvant activity. BALB/c mice were immunized with PCV-2 encapsulated in different kinds of salidroside liposome adjuvants. The PCV-2-specific IgG in immunized mice serum was determined with ELISA. The results showed that when the concentration of ammonium sulfate was 0.26 mol·L−1, ethanol volume 6.5 mL, temperature 43°C, ethanol injection rate 3 mL·min−1, and salidroside liposome could be prepared with high encapsulation efficiency of 94.527%. Salidroside liposome as adjuvant could rapidly induce the production of PCV-2-specific IgG and salidroside liposome I adjuvant proved to provide the best effect among the three kinds of salidroside liposome adjuvants. PMID:25878712

  6. Protective garment ventilation system

    NASA Technical Reports Server (NTRS)

    Lang, R. (Inventor)

    1970-01-01

    A method and apparatus for ventilating a protective garment, space suit system, and/or pressure suits to maintain a comfortable and nontoxic atmosphere within is described. The direction of flow of a ventilating and purging gas in portions of the garment may be reversed in order to compensate for changes in environment and activity of the wearer. The entire flow of the ventilating gas can also be directed first to the helmet associated with the garment.

  7. Differential recognition of the ORF2 region in a complete genome sequence of porcine circovirus type 2 (PCV2) isolated from boar bone marrow in Korea.

    PubMed

    Kweon, Chang-Hee; Nguyen, Lien Thi Kim; Yoo, Mi-Sun; Kang, Seung-Won

    2015-09-15

    Porcine circovirus type 2 (PCV2) is the causative agent of post-weaning multisystemic wasting syndrome (PMWS) in swine. Here, a phylogenetic tree was constructed using PCV2 nucleotide sequences derived from the bone marrow of Korean boar and previously reported PCV2 sequences isolated from various countries. PCV2 from Korean boar bone marrow (KC188796) was classified into the group containing PCV2a-Canada and other PCV2 strain from Korea. While the ORF1 region of the PCV2 genome was highly conserved, ORF2 (the capsid protein coding region) was relatively variable. The nucleotide sequences for bone marrow-derived PCV2 were 93.4-99.0% homologous to the other reference sequences. The deduced amino acid sequences for the ORF1 and ORF2 coding regions were 97.4-99.3% and 84.5-97.4% homologous with the other reference strains, respectively, indicating that KC188796 did not differ markedly from the other PCV2 strains. Phylogenetic analysis demonstrated that bone marrow-derived PCV2 was highly similar to PCV2a from Canada and may be related to persistent PCV2 infections in swine. PMID:25917618

  8. Effect of Dietary Selenium Yeast Supplementation on Porcine Circovirus Type 2 (PCV2) Infections in Mice

    PubMed Central

    Liu, Gang; Yang, Guan; Guan, Guiping; Zhang, Yuzhe; Ren, Wenkai; Yin, Jie; Aguilar, Yordan Martínez; Luo, Wei; Fang, Jun; Yu, Xinglong; Li, Tiejun; Yin, Yulong

    2015-01-01

    The present study was performed to determine the protective role of dietary selenium (Se) yeast supplementation in porcine circovirus type 2 (PCV2) infected mice. Forty-eight Kun Ming female mice were randomly assigned to Se yeast group (0.3%Se +basal diet, n = 24) and control group (basal diet, n = 24). After 3 days of adaptive feeding and 15 days treatment with the experimental feed, mice were challenged by intraperitioneal injection of PCV2 at the dosage of 2000 TCID50 (50% tissue culture infection dose, TCID50). Serum total superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) and interleukin-1 beta (IL-1β) levels were measured at 5, 10, 15, 20 days post infection (dpi). The PCV2 virus load in the liver, spleen and lung, and the microscopic lesions in the liver, spleen and lung also were determined on 5, 10, 15, and 20 dpi. Dietary Se yeast supplementation decreased (Pμ0.05) the serum levels of TNF-α, but had no significant effect on the activity of SOD and the levels of MDA, CRP and IL-1β between experimental and control groups. Dietary Se yeast supplementation had little effect on the PCV2 virus load in the liver, spleen and lung. However, mice in the selenium yeast group showed a significant decrease in microscopic lesion scores in the lung and spleen compared with those in the control group (Pμ0.05). These data indicate Se yeast attenuated the PCV2 infection through altering the systemic inflammation and maintaining the normal organ morphology. PMID:25723390

  9. Intensive Blood-Pressure Control in Hypertensive Chronic Kidney Disease

    PubMed Central

    Appel, Lawrence J.; Wright, Jackson T.; Greene, Tom; Agodoa, Lawrence Y.; Astor, Brad C.; Bakris, George L.; Cleveland, William H.; Charleston, Jeanne; Contreras, Gabriel; Faulkner, Marquetta L.; Gabbai, Francis B.; Gassman, Jennifer J.; Hebert, Lee A.; Jamerson, Kenneth A.; Kopple, Joel D.; Kusek, John W.; Lash, James P.; Lea, Janice P.; Lewis, Julia B.; Lipkowitz, Michael S.; Massry, Shaul G.; Miller, Edgar R.; Norris, Keith; Phillips, Robert A.; Pogue, Velvie A.; Randall, Otelio S.; Rostand, Stephen G.; Smogorzewski, Miroslaw J.; Toto, Robert D.; Wang, Xuelei

    2013-01-01

    BACKGROUND In observational studies, the relationship between blood pressure and end-stage renal disease (ESRD) is direct and progressive. The burden of hypertension-related chronic kidney disease and ESRD is especially high among black patients. Yet few trials have tested whether intensive blood-pressure control retards the progression of chronic kidney disease among black patients. METHODS We randomly assigned 1094 black patients with hypertensive chronic kidney disease to receive either intensive or standard blood-pressure control. After completing the trial phase, patients were invited to enroll in a cohort phase in which the blood-pressure target was less than 130/80 mm Hg. The primary clinical outcome in the cohort phase was the progression of chronic kidney disease, which was defined as a doubling of the serum creatinine level, a diagnosis of ESRD, or death. Follow-up ranged from 8.8 to 12.2 years. RESULTS During the trial phase, the mean blood pressure was 130/78 mm Hg in the intensive-control group and 141/86 mm Hg in the standard-control group. During the cohort phase, corresponding mean blood pressures were 131/78 mm Hg and 134/78 mm Hg. In both phases, there was no significant between-group difference in the risk of the primary outcome (hazard ratio in the intensive-control group, 0.91; P = 0.27). However, the effects differed according to the baseline level of proteinuria (P = 0.02 for interaction), with a potential benefit in patients with a protein-to-creatinine ratio of more than 0.22 (hazard ratio, 0.73; P = 0.01). CONCLUSIONS In overall analyses, intensive blood-pressure control had no effect on kidney disease progression. However, there may be differential effects of intensive blood-pressure control in patients with and those without baseline proteinuria. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Center on Minority Health and Health Disparities, and others.) PMID:20818902

  10. PCV2 vaccination induces IFN-γ/TNF-α co-producing T cells with a potential role in protection.

    PubMed

    Koinig, Hanna C; Talker, Stephanie C; Stadler, Maria; Ladinig, Andrea; Graage, Robert; Ritzmann, Mathias; Hennig-Pauka, Isabel; Gerner, Wilhelm; Saalmüller, Armin

    2015-01-01

    Porcine circovirus type 2 (PCV2) is one of the economically most important pathogens for swine production worldwide. Vaccination is a powerful tool to control porcine circovirus diseases (PCVD). However, it is not fully understood how PCV2 vaccination interacts with the porcine immune system. Especially knowledge on the cellular immune response against PCV2 is sparse. In this study we analysed antigen-specific T cell responses against PCV2 in a controlled vaccination and infection experiment. We focused on the ability of CD4(+) T cells to produce cytokines using multicolour flow cytometry (FCM). Vaccination with a PCV2 subunit vaccine (Ingelvac CircoFLEX®) induced PCV2-specific antibodies only in five out of 12 animals. Conversely, vaccine-antigen specific CD4(+) T cells which simultaneously produced IFN-γ and TNF-α and had a phenotype of central and effector memory T cells were detected in all vaccinated piglets. After challenge, seroconversion occurred earlier in vaccinated and infected pigs compared to the non-vaccinated, infected group. Vaccinated pigs were fully protected against viremia after subsequent challenge. Therefore, our data suggests that the induction of IFN-γ/TNF-α co-producing T cells by PCV2 vaccination may serve as a potential correlate of protection for this type of vaccine. PMID:25888899

  11. Efficacy of a new bivalent vaccine of porcine circovirus type 2 and Mycoplasma hyopneumoniae (Fostera™ PCV MH) under experimental conditions.

    PubMed

    Park, Changhoon; Jeong, Jiwoon; Choi, Kyuhyung; Chae, Chanhee

    2016-01-01

    The objective of this study was to evaluate the efficacy of a new bivalent vaccine (Fostera™ PCV MH, Zoetis) of porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae in growing pigs under experimental conditions. A total of 80 pigs were randomly divided into 8 groups (10 pigs per group). The pigs were administered the bivalent vaccine intramuscularly as a 2.0 mL dose at 21 days of age based on the manufacturer's instructions. Three weeks after vaccination, the pigs were inoculated with either PCV2 (intranasal route) or M. hyopneumoniae (intratracheal route) or both. Regardless of the type of inoculation, vaccinated pigs after challenge exhibited effective reduction of clinical signs, PCV2 viremia levels and mycoplasma nasal shedding, and lung and lymphoid lesion when compared to unvaccinated challenged pigs. Vaccinated challenged pigs had significantly higher (P<0.05) levels of PCV2-specific neutralizing antibodies, and numbers of PCV2-and M. hyopneumoniae-specific interferon-γ secreting cells compared to unvaccinated challenged pigs. This study demonstrates that the bivalent vaccine is able to protect pigs against either PCV2 or M. hyopneumoniae infection or both based on clinical, microbiological, immunological, and pathological evaluation. PMID:26626212

  12. Review of Residential Ventilation Technologies

    SciTech Connect

    Armin Rudd

    2005-08-30

    This paper reviews current and potential ventilation technologies for residential buildings, including a variety of mechanical systems, natural ventilation, and passive ventilation. with particular emphasis on North American climates and construction.

  13. Effective Ventilation Strategies for Obese Patients Undergoing Bariatric Surgery: A Literature Review.

    PubMed

    Hu, Xin Yan

    2016-02-01

    Obesity causes major alterations in pulmonary mechanics. Obese patients undergoing bariatric surgery present mechanical ventilation-related challenges that may lead to perioperative complications. Databases were systematically searched for clinical trials of ventilation maneuvers for obese patients and bariatric surgery. Thirteen randomized controlled trials were selected. The quality of the studies was evaluated with the Critical Appraisal Skills Programme tool, and a matrix was developed to present the essential components of the studies. Eight strategies of ventilation maneuvers were identified. Recruitment maneuvers followed by positive end-expiratory pressure (PEEP) consistently demonstrated effectiveness in obese patients undergoing bariatric surgery. Pressure-controlled ventilation and volume-controlled ventilation did not differ significantly in their efficacy. Noninvasive positive pressure ventilation (NIPPV) during induction was effective in preventing atelectasis and increasing the duration of safe apnea. Equal ratio ventilation can be a useful ventilation strategy. Recruitment maneuvers followed by PEEP are effective ventilation strategies for obese patients undergoing bariatric surgery. During induction, NIPPV provides further benefit. Future studies are needed to examine the postoperative effects of recruitment maneuvers with PEEP as well as the efficacy and safety of equal ratio ventilation. PMID:26939387

  14. The comparison of manual and LabVIEW-based fuzzy control on mechanical ventilation.

    PubMed

    Guler, Hasan; Ata, Fikret

    2014-09-01

    The aim of this article is to develop a knowledge-based therapy for management of rats with respiratory distress. A mechanical ventilator was designed to achieve this aim. The designed ventilator is called an intelligent mechanical ventilator since fuzzy logic was used to control the pneumatic equipment according to the rat's status. LabVIEW software was used to control all equipments in the ventilator prototype and to monitor respiratory variables in the experiment. The designed ventilator can be controlled both manually and by fuzzy logic. Eight female Wistar-Albino rats were used to test the designed ventilator and to show the effectiveness of fuzzy control over manual control on pressure control ventilation mode. The anesthetized rats were first ventilated for 20 min manually. After that time, they were ventilated for 20 min by fuzzy logic. Student's t-test for p < 0.05 was applied to the measured minimum, maximum and mean peak inspiration pressures to analyze the obtained results. The results show that there is no statistical difference in the rat's lung parameters before and after the experiments. It can be said that the designed ventilator and developed knowledge-based therapy support artificial respiration of living things successfully. PMID:25205667

  15. Guide to Home Ventilation

    SciTech Connect

    2010-10-01

    A fact sheet from the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy: Ventilation refers to the exchange of indoor and outdoor air. Without proper ventilation, an otherwise insulated and airtight house will seal in harmful pollutants, such as carbon monoxide, and moisture that can damage a house.

  16. Multifamily Ventilation Retrofit Strategies

    SciTech Connect

    Ueno, K.; Lstiburek, J.; Bergey, D.

    2012-12-01

    In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

  17. Tank pressure control experiment on the space shuttle

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The tank pressure control experiment is a demonstration of NASA intent to develop new technology for low-gravity management of the cryogenic fluids that will be required for future space systems. The experiment will use freon as the test fluid to measure the effects of jet-induced fluid mixing on storage tank pressure and will produce data on low-gravity mixing processes critical to the design of on-orbit cryogenic storage and resupply systems. Basic data on fluid motion and thermodynamics in low gravity is limited, but such data is critical to the development of space transfer vehicles and spacecraft resupply facilities. An in-space experiment is needed to obtain reliable data on fluid mixing and pressure control because none of the available microgravity test facilities provide a low enough gravity level for a sufficient duration to duplicate in-space flow patterns and thermal processes. Normal gravity tests do not represent the fluid behavior properly; drop-tower tests are limited in length of time available; aircraft low-gravity tests cannot provide the steady near-zero gravity level and long duration needed to study the subtle processes expected in space.

  18. Hydraulic pressure control apparatus for a continuously variable transmission

    SciTech Connect

    Shigematsu, T.; Watanabe, T.

    1986-10-28

    This patent describes a hydraulic pressure control apparatus for a continuously variable transmission. The transmission includes a driving pulley having a fixed member and a movable member. The movable member is actuated by a hydraulic cylinder to form a V-shaped opening between the movable member and the fixed member. A driven pulley has another fixed member and another movable member. The another movable member is similarly actuated by another hydraulic cylinder to form a similar V-shaped opening between the another movable member and the another fixed member. A belt member spans the driving and driven pulleys such that an effective diameter of the driving and driven pulleys can be varied with respect to each other to obtain different speed ratios. The hydraulic pressure control apparatus comprises: a first presssure detecting means in communication with the hydraulic cylinder of the driving pulley for detecting a pressure of the hydraulic cylinder of the driving pulleys, the first pressure detecting means outputting a first pressure signal having a first value; and a second pressure detecting means in communication with another hydraulic cylinder of the driven pulley for detecting the pressure of the another hydraulic cylinder of the driven pulley, the second pressure detecting means outputting a second pressure signal having a second value.

  19. Realtime mine ventilation simulation

    SciTech Connect

    McDaniel, K.H.; Wallace, K.G. Jr.

    1997-04-01

    This paper describes the development of a Windows based, interactive mine ventilation simulation software program at the Waste Isolation Pilot Plant (WIPP). To enhance the operation of the underground ventilation system, Westinghouse Electric Corporation developed the program called WIPPVENT. While WIPPVENT includes most of the functions of the commercially available simulation program VNETPC and uses the same subroutine to calculate airflow distributions, the user interface has been completely rewritten as a Windows application with screen graphics. WIPPVENT is designed to interact with WIPP ventilation monitoring systems through the sitewise Central monitoring System. Data can be continuously collected from the Underground Ventilation Remote Monitoring and Control System (e.g., air quantity and differential pressure) and the Mine Weather Stations (psychrometric data). Furthermore, WIPPVENT incorporates regulator characteristic curves specific to the site. The program utilizes this data to create and continuously update a REAL-TIME ventilation model. This paper discusses the design, key features, and interactive capabilities of WIPPVENT.

  20. Immunogenicity and immunoprotection of porcine circovirus type 2 (PCV2) Cap protein displayed by Lactococcus lactis.

    PubMed

    Li, Peng-cheng; Qiao, Xu-wen; Zheng, Qi-sheng; Hou, Ji-bo

    2016-01-27

    The capsid (Cap) protein, an important immunoprotective protein of porcine circovirus type 2 (PCV2), was expressed on the cell surface of the Gram-positive food-grade bacterium, Lactococcus lactis. Cap protein was fused to the peptidoglycan binding domain (known as the protein anchor domain, PA) of the lactococcal AcmA cell-wall hydrolase. The Cap protein fusion was non-covalently rebound to the surface of non-genetically modified, non-living high-binder L. lactis cells (designated Gram-positive enhancer matrix (GEM) particles). Expression of the recombinant GEM-displaying capsid protein (GEM-PA-Cap) was verified by Western blotting and immunofluorescence and transmission electron microscopy assays. To evaluate the immunogenicity of the recombinant Cap protein (rCap), 20 PCV2-seronegative piglets were immunized with the GEM-PA-Cap subunit vaccine, GEM alone, or phosphate-buffered saline (PBS, challenge control and empty control). Each group consisted of five piglets. The results showed that the level of PCV2-specific antibodies in piglets immunized with the GEM-PA-Cap subunit vaccine was significantly higher than that of the piglets immunized with GEM alone or the control group at all the time points post-vaccination (P<0.01). After challenge with the PCV2 wild-type strain, piglets that received the GEM-PA-Cap subunit vaccine showed significantly higher average daily weight gain (DWG) and shorter fever duration than the other two groups (P<0.001). Furthermore, a significant reduction in the gross lung lesion scores and lymph node lesion scores was noted in the GEM-PA-Cap-immunized group compared with the scores of the GEM or PBS-treated group (P<0.01). The results suggest that recombinant rCap displayed by L. lactis GEM particles provided the piglets with significant immunoprotection from PCV2-associated disease. Thus, the novel GEM-PA-Cap subunit vaccine has potential to be considered an effective and safe candidate vaccine against PCV2 infection in piglets. PMID:26372858

  1. Approaches to manual ventilation.

    PubMed

    Davies, John D; Costa, Brian K; Asciutto, Anthony J

    2014-06-01

    Manual ventilation is a basic skill that involves airway assessment, maneuvers to open the airway, and application of simple and complex airway support devices and effective positive-pressure ventilation using a bag and mask. An important part of manual ventilation is recognizing its success and when it is difficult or impossible and a higher level of support is necessary to sustain life. Careful airway assessment will help clinicians identify what and when the next step needs to be taken. Often simple airway maneuvers such as the head tilt/chin lift and jaw thrust can achieve a patent airway. Appropriate use of airway adjuncts can further aid the clinician in situations in which airway maneuvers may not be sufficient. Bag-mask ventilation (BMV) plays a vital role in effective manual ventilation, improving both oxygenation and ventilation as well as buying time while preparations are made for endotracheal intubation. There are, however, situations in which BMV may be difficult or impossible. Anticipation and early recognition of these situations allows clinicians to quickly make adjustments to the method of BMV or to employ a more advanced intervention to avoid delays in establishing adequate oxygenation and ventilation. PMID:24891193

  2. The Relationship of Diet to Blood Pressure Control

    PubMed Central

    Jones, Walretta O.; Brown, Jay

    1979-01-01

    Sodium restriction has become an integral part of the medical management of hypertension. In general the degree of sodium restriction recommended by physicians depends upon the severity of the disease. The commonly prescribed sodium restricted diets are classified as mild and moderate. Mild sodium restriction refers to a diet in which 3.0-4.0 gm of sodium are allowed per day. Moderate sodium restriction is indicated when hypertension is more severe; 1-2 gm of sodium are allowed daily. Sodium added in the processing of foods contributes significantly to the sodium content of the diet. “Convenience” and “fast” foods are high in sodium and are not allowed the hypertensive patients. Significant advances have occurred in the past decade in the medical management of hypertension. The sodium-restricted diet remains the cornerstone of effective blood pressure control. Therefore, nutrition must become an integral part of the hypertensive treatment program. PMID:529319

  3. Ventilator-patient dyssynchrony induced by change in ventilation mode.

    PubMed

    Lydon, A M; Doyle, M; Donnelly, M B

    2001-06-01

    Patient-ventilator interactions may be coordinated (synchronous) or uncoordinated (dyssynchronous). Ventilator-patient dyssynchrony increases the work of breathing by imposing a respiratory muscle workload. Respiratory centre output responds to feedback from respiratory muscle loading. Mismatching of respiratory centre output and mechanical assistance results in dyssynchrony. We describe a case of severe patient-ventilator dyssynchrony and hypothesize that dyssynchrony was induced by a change in mode of ventilation from pressure-cycled to volume-cycled ventilation, due to both ventilator settings and by the patient's own respiratory centre adaptation to mechanical ventilation. The causes, management and clinical implications of dyssynchrony are discussed. PMID:11439799

  4. Ventilating Air-Conditioner

    NASA Technical Reports Server (NTRS)

    Dinh, Khanh

    1994-01-01

    Air-conditioner provides ventilation designed to be used alone or incorporated into cooling or heating system operates efficiently only by recirculating stale air within building. Energy needed to operate overall ventilating cooling or heating system slightly greater than operating nonventilating cooling or heating system. Helps to preserve energy efficiency while satisfying need for increased forced ventilation to prevent accumulation of undesired gases like radon and formaldehyde. Provides fresh treated air to variety of confined spaces: hospital surgeries, laboratories, clean rooms, and printing shops and other places where solvents used. In mobile homes and portable classrooms, eliminates irritant chemicals exuded by carpets, panels, and other materials, ensuring healthy indoor environment for occupants.

  5. Body ventilators. Equipment and techniques.

    PubMed

    Gilmartin, M E

    1996-06-01

    Body ventilators have been used since the late 1800s and are still used today. This article reviews all of the body ventilators available today including tanks, cuirasses, wraps, rocking beds, and intermittent abdominal pressure ventilators. Diaphragm pacers and glossopharyngeal breathing also are reviewed. Clinical application of the ventilators, initiation, patient monitoring, and follow-up are reviewed. PMID:9390879

  6. Why We Ventilate

    SciTech Connect

    Logue, Jennifer M.; Sherman, Max H.; Price, Phil N.; Singer, Brett C.

    2011-09-01

    It is widely accepted that ventilation is critical for providing good indoor air quality (IAQ) in homes. However, the definition of"good" IAQ, and the most effective, energy efficient methods for delivering it are still matters of research and debate. This paper presents the results of work done at the Lawrence Berkeley National Lab to identify the air pollutants that drive the need for ventilation as part of a larger effort to develop a health-based ventilation standard. First, we present results of a hazard analysis that identified the pollutants that most commonly reach concentrations in homes that exceed health-based standards or guidelines for chronic or acute exposures. Second, we present results of an impact assessment that identified the air pollutants that cause the most harm to the U.S. population from chronic inhalation in residences. Lastly, we describe the implications of our findings for developing effective ventilation standards.

  7. Learning about ventilators

    MedlinePlus

    ... knobs and buttons that are controlled by a respiratory therapist, nurse, or doctor. Has tubes that connect to ... by health care providers including doctors, nurses, and respiratory therapists. Patients who need ventilators for long periods may ...

  8. Postweaning multisystemic wasting syndrome (PMWS) in pigs in Croatia: detection and characterisation of porcine circovirus type 2 (PCV2).

    PubMed

    Lipej, Z; Segalés, J; Toplak, I; Sostarić, B; Roić, Besi; Lojkić, M; Hostnik, P; Grom, J; Barlic-Maganja, Darja; Zarković, Kamelija; Oraić, D

    2005-01-01

    The objective of this study was to characterise porcine circovirus type 2 (PCV2) from pigs with naturally occurring postweaning multisystemic wasting syndrome (PMWS) in Croatia, and to determine the epizootiological, clinical and pathomorphological features of the disease. During a systematic health monitoring programme conducted in the period from January 2002 to June 2003, PMWS was suspected on eight different pig-producing farms in Croatia. The diagnosis of PMWS met all three key criteria: the presence of compatible clinical signs, the presence of the characteristic microscopic lymphoid lesions, and the detection of PCV2 within the lesions by polymerase chain reaction (PCR) and by in situ hybridisation (ISH). Moreover, PCV2 DNA from swine tissues was extracted and sequenced. The phylogenetic analysis of 4 Croatian PCV2 strains showed close relationship to PCV2 strains isolated in Slovenia, France, the Netherlands, the United Kingdom, China and Hungary. PCV2 was also demonstrated by electron microscopy in the lymph node of an affected animal. This is the first demonstration of PMWS in Croatia based on all scientifically accepted diagnostic criteria. PMID:16156133

  9. A live-attenuated chimeric PCV2 vaccine based on subtype 2b is transmitted to contact pigs but is not upregulated by concurrent infection with PPV and PRRSV and is efficacious in a triple challenge co-infection model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine the safety and efficacy of a new live-attenuated chimeric PCV1/2b vaccine. Forty-six, 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups (Negative controls, positive controls, Vac-0, Vac-0-PCV2, Contact-PCV2, Vac-28-PCV2). All pigs we...

  10. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity

    NASA Technical Reports Server (NTRS)

    Hasan, Mohammad M.; Lin, Chin S.; Knoll, Richard H.; Bentz, Michael D.

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83% by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/sq m). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 C, respectively. The boiling process during the entire heating period, as well as the jet-induced mixing process for the first 2 min of the mixing period, was also recorded on video. The unique features of the experimental results are the sustainability of high liquid superheats for long periods and the occurrence of explosive boiling at low heat fluxes (0.86 to 1.1 kW/sq m). For a heat flux of 0.97 kW/sq m, a wall superheat of 17.9 C was attained in 10 min of heating. This superheat was followed by an explosive boiling accompanied by a pressure spike of about 38% of the tank pressure at the inception of boiling. However, at this heat flux the vapor blanketing the heating surface could not be sustained. Steady nucleate boiling continued after the explosive boiling. The jet-induced fluid mixing results were obtained for jet Reynolds numbers of 1900 to 8000 and Weber numbers of 0.2 to 6.5. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number.

  11. Solar Thermal Upper Stage Liquid Hydrogen Pressure Control Testing

    NASA Technical Reports Server (NTRS)

    Moore, J. D.; Otto, J. M.; Cody, J. C.; Hastings, L. J.; Bryant, C. B.; Gautney, T. T.

    2015-01-01

    High-energy cryogenic propellant is an essential element in future space exploration programs. Therefore, NASA and its industrial partners are committed to an advanced development/technology program that will broaden the experience base for the entire cryogenic fluid management community. Furthermore, the high cost of microgravity experiments has motivated NASA to establish government/aerospace industry teams to aggressively explore combinations of ground testing and analytical modeling to the greatest extent possible, thereby benefitting both industry and government entities. One such team consisting of ManTech SRS, Inc., Edwards Air Force Base, and Marshall Space Flight Center (MSFC) was formed to pursue a technology project designed to demonstrate technology readiness for an SRS liquid hydrogen (LH2) in-space propellant management concept. The subject testing was cooperatively performed June 21-30, 2000, through a partially reimbursable Space Act Agreement between SRS, MSFC, and the Air Force Research Laboratory. The joint statement of work used to guide the technical activity is presented in appendix A. The key elements of the SRS concept consisted of an LH2 storage and supply system that used all of the vented H2 for solar engine thrusting, accommodated pressure control without a thermodynamic vent system (TVS), and minimized or eliminated the need for a capillary liquid acquisition device (LAD). The strategy was to balance the LH2 storage tank pressure control requirements with the engine thrusting requirements to selectively provide either liquid or vapor H2 at a controlled rate to a solar thermal engine in the low-gravity environment of space operations. The overall test objective was to verify that the proposed concept could enable simultaneous control of LH2 tank pressure and feed system flow to the thruster without necessitating a TVS and a capillary LAD. The primary program objectives were designed to demonstrate technology readiness of the SRS concept at a system level as a first step toward actual flight vehicle demonstrations. More specific objectives included testing the pressure and feed control system concept hardware for functionality, operability, and performance. Valuable LH2 thermodynamic and fluid dynamics data were obtained for application to both the SRS concept and to future missions requiring space-based cryogen propellant management.

  12. Indications for mechanical ventilation.

    PubMed

    Tung, A

    1997-01-01

    Indications for mechanical ventilation have evolved substantially since widespread use of ventilatory support began in the early 1960s. While the metabolic and blood-gas alterations that mandate institution of ventilatory support have remained unaltered, new noninvasive modes of ventilation have widened the therapeutic options available to patients in acute respiratory failure. An understanding of the effect of mechanical ventilation on other organ systems has clarified the role of mechanical ventilation in the treatment of conditions other than respiratory failure such as stroke or head injury. Studies in patients recovering from major surgery have better defined the benefits and risks of postoperative mechanical ventilation. Finally, a better understanding of disease processes has led to more prognostic information that can help physicians, patients, and families decide on limits to compassionate care. The proper use of mechanical ventilation in disease states that do not involve respiratory failure as their primary manifestation is also important in light of the risks of respiratory support. In patients with CNS injury, the role of hyperventilation is limited to acute control of dangerous elevations of intracranial pressure. Although hypocarbia has been proposed to improve regional cerebral blood flow, studies have not demonstrated an improvement in outcome, suggesting that the risks of intubation, tracheal stimulation, sedation, and inability to examine the mental status outweigh any benefit. Some evidence suggests a detrimental effect from prolonged hyperventilation. The use of mechanical ventilation in postoperative care is another area that requires scrutiny. Numerous studies have shown that with coordination of care between surgeons, anesthesiologists, and nurses, many patients can be extubated significantly sooner than in the past. As techniques for administering anesthesia, performing surgery, and managing pain and mild respiratory insufficiency improve, knowledge in this area will continue to develop. Finally, the relation between mechanical ventilation, quality of life, and patient autonomy has come to play a greater role as the population ages. In many situations, respiratory failure represents the end stage of an irreversible disease. Whereas respiratory failure secondary to pulmonary contusion in young patients does not indicate a poor outcome, progressive respiratory failure in cystic fibrosis or following bone marrow transplantation usually represents a preterminal event. Understanding the epidemiology of respiratory failure in different disease categories is important to physicians, patients, and families in making informed decisions about their care. Mechanical ventilation represents a vital, fundamental form of life support. As the diseases, tools, and treatments change in anesthesia and critical care, careful definition of the role of mechanical ventilation in specific diseases, the route by which it is delivered, and the ability of such a form of life support to affect outcome will continue to be necessary. PMID:9113518

  13. Evaluating the impact of PCV-10 on invasive pneumococcal disease in Brazil: A time-series analysis.

    PubMed

    Andrade, Ana Lucia; Minamisava, Ruth; Policena, Gabriela; Cristo, Elier B; Domingues, Carla Magda S; de Cunto Brandileone, Maria Cristina; Almeida, Samanta Cristine Grassi; Toscano, Cristiana Maria; Bierrenbach, Ana Luiza

    2016-02-01

    Routine infant immunization with 10-valent pneumococcal conjugate vaccine (PCV-10) began in Brazil in 2010. The impact of the PCV-10 on rates of invasive pneumococcal disease (IPD) at the population level was not yet evaluated. Serotype-specific IPD changes after PCV-10 introduction is still to be determined. Data from national surveillance system for notifiable diseases (SINAN) and national reference laboratory for S. pneumoniae in Brazil (IAL) were linked to enhance case ascertainment of IPD. An interrupted time-series analysis was conducted to predict trends in the postvaccination IPD rates in the absence of PCV-10 vaccination, taking into consideration seasonality and secular trends. PCVs serotype-specific distribution were assessed before (2008-2009) and after (2011-2013) the introduction of PCV-10 in the immunization program. A total of 9,827 IPD cases were identified from 2008-2013 when combining SINAN and IAL databases. Overall, PCV-10 types decreased by 41.3% after PCV-10 vaccination period, mostly in children aged 2-23 months, while additional PCV-13 serotypes increased by 62.8% mainly in children under 5-year of age. For children aged 2-23 months, targeted by the immunization program, we observed a 44.2% (95%CI, 15.8-72.5%) reduction in IPD rates. In contrast, significant increase in IPD rates were observed for adults aged 18-39 y (18.9%, 95%CI 1.1-36.7%), 40-64 y (52.5%, 95%CI 24.8-80.3%), and elderly ≥ 65 y (79.3%, 95%CI 62.1-96.5%). This is the first report of a time-series analysis for PCV impact in IPD conducted at national level data in a developing country. We were able to show significant impact of PCV-10 on IPD for age groups targeted by vaccination in Brazil, 3 y after its introduction. No impact on other age groups was demonstrated. PMID:26905679

  14. Perinatal taurine exposure affects adult arterial pressure control

    PubMed Central

    Roysommuti, Sanya; Wyss, J. Michael

    2012-01-01

    Taurine is an abundant free amino acid found in mammalian cells that contributes to many physiologic functions from that of a simple cell osmolyte to a programmer of adult health and disease. Taurine’s contribution extends from conception throughout life, but its most critical exposure period is during perinatal life. In adults, taurine supplementation prevents or alleviates cardiovascular disease and related complications. In contrast, low taurine consumption coincides with increased risk of cardiovascular disease, obesity and type II diabetes. This review focuses on the effects that altered perinatal taurine exposure has on long-term mechanisms that control adult arterial blood pressure and could thereby contribute to arterial hypertension through its ability to program these cardiovascular regulatory mechanisms very early in life. The modifications of these mechanisms can last a lifetime and transfer to the next generation, suggesting that epigenetic mechanisms underlie the changes. The ability of perinatal taurine exposure to influence arterial pressure control mechanisms and hypertension in adult life appears to involve the regulation of growth and development, the central and autonomic nervous system, the renin-angiotensin system, glucose-insulin interaction and changes to heart, blood vessels and kidney function. PMID:23070226

  15. Piezoelectric MEMS array package for distributed CMP pressure control

    NASA Astrophysics Data System (ADS)

    Mayyas, Mohammad

    2015-06-01

    In this paper we develop an array of pressure control units that locally and selectively pressurizes the wafer for better uniformity of thickness removal during the chemical mechanical planarization (CMP) process. A real-time metrology measurement determines where on the wafer the microactuator array should be activated in order to improve the overall uniformity of the wafer surface. We developed a new micro surface actuation mechanism comprising an array of piezoelectric bending discs sandwiched in a single multi-layer package. We obtained scalable manufacturing and packaging methods that do not only reduce the mechanical misalignment tolerances of such arrays, but also improve their electrical interconnect reliability under harsh environments. The finite element models showed that an individual disc in the array can generate local contact pressure. CMP experiments showed that such locality controlled the material removal rate on silicon wafer. A microactuator unit in an array delivered precise displacement and large pressure outputs measured for a wide range of input voltages. The static and dynamic responses of the microactuator were linear, and had a fast response to voltage input, making it suitable for high speed distributed pressure compensation during the CMP process.

  16. Understanding Contributors to Racial Disparities in Blood Pressure Control

    PubMed Central

    Kressin, Nancy R.; Orner, Michelle B.; Manze, Meredith; Glickman, Mark E.; Berlowitz, Dan

    2010-01-01

    Background Racial disparities in blood pressure (BP) control are well documented but poorly understood; prior studies have only included a limited range of potential explanatory factors. We examined a comprehensive set of putative factors related to blood pressure control, including patients clinical and sociodemographic characteristics, beliefs about BP and BP medications, medication adherence, and experiences of discrimination, to determine if the impact of race on BP control remains after accounting for such factors. Methods & Results We recruited 806 White and Black patients with hypertension from an urban safety-net hospital. From a questionnaire administered to patients after their clinic visits, electronic medical record and BP data, we assessed an array of patient factors. We then examined the association of patient factors with BP control by modeling it as a function of the covariates using random effects logistic regression. Blacks indicated worse medication adherence, more discrimination, and more concerns about high BP and BP medications, compared to Whites. After accounting for all factors, race was no longer a significant predictor of BP control. Conclusions Results suggest that equalizing patients health beliefs, medication adherence, and experiences with care could ameliorate disparities in BP control. Additional attention must focus on the factors associated with race to identify, and ultimately intervene on, the causes of racial disparities in BP outcomes. PMID:20233981

  17. [Blood pressure control in the area of surgical interventions].

    PubMed

    Simanski, Olaf; Janda, Matthias; Bajorat, Jrn; Nguyen, Ngon C; Hofmockel, Rainer; Lampe, Bernhard P

    2009-10-01

    For specific surgical interventions, such as aortic stent implantation, it might be temporarily necessary to decrease mean arterial pressure to rather low levels (around 40 mm Hg). Such hypotensive pressure levels are necessary to avoid intra- and postoperative intricacies. Traditionally, the drug Nitroprussidnatrium is used for this task. To adjust the correct amount of drug to reach the target pressure as fast as possible and without overshoot, the anaesthetists typically use empirical knowledge and might need several minutes until the target point is reached. In our research group, an adaptive control system was developed for this task which is able to compute and set the transient drug release automatically. For the design and testing of the adaptive control strategy, the well known Guyton model was implemented into the MATLAB/Simulink development environment. This paper describes the implementation and adaption of the Guyton model to hypotensive pressure control and provides some algorithmic details of the adaptive control strategy for automatic drug delivery in deep hypotension. The designed control system was successfully validated in animal trials (25 trials on 7 pigs). Following this, an additional controller component for increase of blood pressure with the help of the drug Noradrenalin was implemented. It is now possible to increase blood pressure to a specific value to save defined cerebral perfusion pressure for patients with craniocerebral injury. In a second pilot trial, this controller extension was tested in 10 pigs. PMID:19807293

  18. Tank pressure control in low gravity by jet mixing

    NASA Technical Reports Server (NTRS)

    Bentz, Michael D.

    1993-01-01

    The Tank Pressure Control Experiment (TPCE) is a space experiment developed to help meet the need for a critical aspect of cryogenic fluid management technology: control of storage tank pressures in the absence of gravity by forced convective mixing. The experiment used a 13.7-liter tank filled to a constant 83 percent level with refrigerant 113 at near saturation conditions to simulate the fluid dynamics and thermodynamics of cryogenic fluids in space applications. The objectives of TPCE were to characterize the fluid dynamics of axial jet-induced mixing in low gravity, to evaluate the validity of empirical mixing models, and to provide data for use in developing and validating computational fluid dynamic models of mixing processes. TPCE accomplished all of its objectives in flight on Space Shuttle Mission STS-3 in August of 1991. The range of flow patterns photographed generally confirmed a prior correlation based on drop tower tests. A closed-form equation derived from a simple thermodynamic model was found to provide a first-order prediction of the pressure reduction time as a function of mixer parameters, tank size, and fluid thermophysical properties. Low energy mixing jets were found to be effective and reliable at reducing thermal non-uniformities, promoting heat and mass transfer between the phases, and reducing tank pressure.

  19. Perinatal taurine exposure affects adult arterial pressure control.

    PubMed

    Roysommuti, Sanya; Wyss, J Michael

    2014-01-01

    Taurine is an abundant, free amino acid found in mammalian cells that contributes to many physiologic functions from that of a simple cell osmolyte to a programmer of adult health and disease. Taurine's contribution extends from conception throughout life, but its most critical exposure period is during perinatal life. In adults, taurine supplementation prevents or alleviates cardiovascular disease and related complications. In contrast, low taurine consumption coincides with increased risk of cardiovascular disease, obesity and type II diabetes. This review focuses on the effects that altered perinatal taurine exposure has on long-term mechanisms that control adult arterial blood pressure and could thereby contribute to arterial hypertension through its ability to program these cardiovascular regulatory mechanisms very early in life. The modifications of these mechanisms can last a lifetime and transfer to the next generation, suggesting that epigenetic mechanisms underlie the changes. The ability of perinatal taurine exposure to influence arterial pressure control mechanisms and hypertension in adult life appears to involve the regulation of growth and development, the central and autonomic nervous system, the renin-angiotensin system, glucose-insulin interaction and changes to heart, blood vessels and kidney function. PMID:23070226

  20. Pressure Controlled Heat Pipe for Precise Temperature Control

    NASA Astrophysics Data System (ADS)

    Sarraf, David B.; Tamanna, Sanjida; Dussinger, Peter M.

    2008-01-01

    This paper discusses the design and test of a pressure controlled heat pipe (PCHP) for spacecraft thermal management. The PCHP combines a conventional grooved aluminum-ammonia heat pipe with a variable-volume non-condensable gas reservoir to create a heat pipe whose conductance can be precisely controlled. Testing showed that a prototype PCHP was capable of maintaining a stable evaporator temperature within 0.1 K despite wide swings in heat load and heat sink temperature. A similarly-sized variable-conductance heat pipe (VCHP) yielded temperature swings of over 3.5 K for the same variation of heat load and sink temperature. Using a non-optimized control system, the PCHP was capable of maintaining evaporator temperature within 0.05 K over time. The PCHP had a much faster transient response than other devices such as heated-reservoir VCHPs, as well as providing a means for changing the set point temperature after assembly. The PCHP is a significant advance over other means of temperature control, even in its current non-optimized state.

  1. Evaluation of the capability of the PCV2 genome to encode miRNAs: lack of viral miRNA expression in an experimental infection.

    PubMed

    Núñez-Hernández, Fernando; Pérez, Lester J; Vera, Gonzalo; Córdoba, Sarai; Segalés, Joaquim; Sánchez, Armand; Núñez, José I

    2015-01-01

    Porcine circovirus type 2 (PCV2) is a ssDNA virus causing PCV2-systemic disease (PCV2-SD), one of the most important diseases in swine. MicroRNAs (miRNAs) are a new class of small non-coding RNAs that regulate gene expression post-transcriptionally. Viral miRNAs have recently been described and the number of viral miRNAs has been increasing in the past few years. In this study, small RNA libraries were constructed from two tissues of subclinically PCV2 infected pigs to explore if PCV2 can encode viral miRNAs. The deep sequencing data revealed that PCV2 does not express miRNAs in an in vivo subclinical infection. PMID:25934266

  2. A Pressure Control Method for Emulsion Pump Station Based on Elman Neural Network

    PubMed Central

    Tan, Chao; Qi, Nan; Yao, Xingang; Wang, Zhongbin; Si, Lei

    2015-01-01

    In order to realize pressure control of emulsion pump station which is key equipment of coal mine in the safety production, the control requirements were analyzed and a pressure control method based on Elman neural network was proposed. The key techniques such as system framework, pressure prediction model, pressure control model, and the flowchart of proposed approach were presented. Finally, a simulation example was carried out and comparison results indicated that the proposed approach was feasible and efficient and outperformed others. PMID:25861253

  3. Blood pressure control to prevent decline in cognition after stroke

    PubMed Central

    Ihle-Hansen, Hege; Thommessen, Bente; Fagerland, Morten W; Øksengård, Anne R; Wyller, Torgeir B; Engedal, Knut; Fure, Brynjar

    2015-01-01

    Background Treatment of hypertension post-stroke preserves cognition through prevention of recurrent stroke, but it is not clear whether it prevents cognitive decline through other mechanisms. We aimed to describe changes in blood pressure from baseline to 1 year post-stroke and to evaluate the association between achieved blood pressure targets and cognitive function, mild cognitive impairment (MCI), and dementia. Methods We included patients with first-ever stroke, and defined achieved blood pressure goals as systolic blood pressure (SBP) in the categories ≤125 mmHg, ≤140 mmHg, and ≤160 mmHg, SBP reduction of ≥10 mmHg, and diastolic blood pressure (DBP) reduction of ≥5 mmHg. The main outcome variables were cognitive assessments 1 year post stroke. Secondary outcomes were diagnoses of MCI or dementia. Results Forty-one of 166 patients (25%) reached SBP ≤125 mmHg after 1 year, 92/166 (55%) reached SBP ≤140 mmHg, and 150/166 (90%) reached SBP ≤160 mmHg. SBP was reduced by ≥10 mmHg in 44/150 (29%) and DBP by ≥5 mmHg in 57/150 (38%). We did not find any statistically significant associations between cognitive test performances and different blood pressure goals (P=0.070–1.0). Nor was there any significant association between achieved goal blood pressure or blood pressure reduction after 1 year and the diagnoses of MCI or dementia (P=0.32–0.56). Conclusion Treatment of hypertension is important for primary and secondary prevention of stroke. Showing a potential beneficial effect of blood pressure control on cognitive function, however, probably needs longer follow-up. PMID:26089677

  4. Ventilation technologies scoping study

    SciTech Connect

    Walker, Iain S.; Sherman, Max H.

    2003-09-30

    This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the needs of California, determining residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and level of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

  5. Ventilation flow: Submerged

    NASA Technical Reports Server (NTRS)

    Hutchinson, D.

    1985-01-01

    The ventilation system on a submarine is discussed. When the submarine is submerged. The ventilation system provides a conditioned atmosphere in the ship with complete isolation from the outside. A conditioned atmosphere includes not only filtration and temperature and humidity control, but also air purification (removal of potentially harmful quantities of impurities and comtaminants) and revitalization (addition of vital life support oxygen). Carbon dioxide removal, the oxygen system, air conditioning, carbon monoxide removal, hydrogen removal, and atmosphere monitoring systems are among the topics discussed.

  6. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.

    2011-04-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

  7. Central Fan Integrated Ventilation Systems

    SciTech Connect

    2009-05-12

    This information sheet describes one example of a ventilation system design, a central fan integrated supply (CFIS) system, a mechanical ventilation and pollutant source control to ensure that there is reasonable indoor air quality inside the house.

  8. Invasive ventilation modes in children: a systematic review and meta-analysis

    PubMed Central

    2011-01-01

    Introduction The purpose of the present study was to critically review the existing body of evidence on ventilation modes for infants and children up to the age of 18 years. Methods The PubMed and EMBASE databases were searched using the search terms 'artificial respiration', 'instrumentation', 'device', 'devices', 'mode', and 'modes'. The review included only studies comparing two ventilation modes in a randomized controlled study and reporting one of the following outcome measures: length of ventilation (LOV), oxygenation, mortality, chronic lung disease and weaning. We quantitatively pooled the results of trials where suitable. Results Five trials met the inclusion criteria. They addressed six different ventilation modes in 421 children: high-frequency oscillation (HFO), pressure control (PC), pressure support (PS), volume support (VS), volume diffusive respirator (VDR) and biphasic positive airway pressure. Overall there were no significant differences in LOV and mortality or survival rate associated with the different ventilation modes. Two trials compared HFO versus conventional ventilation. In the pooled analysis, the mortality rate did not differ between these modes (odds ratio = 0.83, 95% confidence interval = 0.30 to 1.91). High-frequency ventilation (HFO and VDR) was associated with a better oxygenation after 72 hours than was conventional ventilation. One study found a significantly higher PaO2/FiO2 ratio with the use of VDR versus PC ventilation in children with burns. Weaning was studied in 182 children assigned to either a PS protocol, a VS protocol or no protocol. Most children could be weaned within 2 days and the weaning time did not significantly differ between the groups. Conclusions The literature provides scarce data for the best ventilation mode in critically ill children beyond the newborn period. There is no evidence, however, that high-frequency ventilation reduced mortality and LOV. Longer-term outcome measures such as pulmonary function, neurocognitive development, and cost-effectiveness should be considered in future studies. PMID:21241490

  9. Pressure Control System Design for a Closed Crop Growth Chamber

    NASA Technical Reports Server (NTRS)

    Tsai, K.; Blackwell, C.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    The Controlled Ecological Life Support System (CELSS) is an area of active research at NASA. CELSS is a plant-based bioregenerative life support system for long term manned space flights where resupply is costly or impractical. The plants in a CELSS will function to convert the carbon dioxide (exhaled by the crew) into oxygen, purify non-potable water into potable quality water, and provide food for the crew. Prior to implementing a CELSS life support system, one must have knowledge on growing plants in a closed chamber under low gravity. This information will come from research to be conducted on the CELSS Test Facility that will operate on the Space Station Freedom. Currently a ground-based CELSS Test Facility is being built at NASA Ames Research Center. It is called the EDU (Engineering Development Unit). This system will allow researchers to identify issues that may cause difficulties in the development of the CELSS Test Facility and aid in the development of new needed technologies. The EDU consists of a 1 m2 crop growth chamber that is surrounded by a containment enclosure. The containment enclosure isolates the system so there is very little mass and thermal exchange with the ambient. The leakage rate is on the order of 1 % of the enclosure's volume per day (with 0.2S psi pressure difference). The thermal leakage is less than 0.5% of the electrical power supplied to the system per degree Celsius difference from the surrounding. The pressure in the containment enclosure is regulated at 62.5 Pa below the ambient by an active controller. The goal is to maintain this set point for a variety of conditions, such as a range of operating temperatures, heat load variations that occur when the lights are turned on and off, and fluctuations in ambient pressure. In addition certain transition tracking performance is required. This paper illustrates the application of some advanced systems control methods to the task of synthesizing the EDU's pressure control system.

  10. Measure Guideline: Ventilation Cooling

    SciTech Connect

    Springer, D.; Dakin, B.; German, A.

    2012-04-01

    The purpose of this measure guideline on ventilation cooling is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

  11. Laboratory Ventilation and Safety.

    ERIC Educational Resources Information Center

    Steere, Norman V.

    1965-01-01

    In order to meet the needs of both safety and economy, laboratory ventilation systems must effectively remove air-borne toxic and flammable materials and at the same time exhaust a minimum volume of air. Laboratory hoods are the most commonly used means of removing gases, dusts, mists, vapors, and fumed from laboratory operations. To be effective,…

  12. RESIDENTIAL VENTILATION STUDY

    EPA Science Inventory

    This project evaluated the effectiveness, first costs and operational costs of various types of residential ventilation systems in three different climates in the U.S. The Agency, through its Energy Star Program, recommends that builders construct homes that are energy efficient ...

  13. Laboratory Ventilation and Safety.

    ERIC Educational Resources Information Center

    Steere, Norman V.

    1965-01-01

    In order to meet the needs of both safety and economy, laboratory ventilation systems must effectively remove air-borne toxic and flammable materials and at the same time exhaust a minimum volume of air. Laboratory hoods are the most commonly used means of removing gases, dusts, mists, vapors, and fumed from laboratory operations. To be effective,

  14. Space station ventilation study

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Allen, G. E.

    1972-01-01

    A ventilation system design and selection method which is applicable to any manned vehicle were developed. The method was used to generate design options for the NASA 33-foot diameter space station, all of which meet the ventilation system design requirements. System characteristics such as weight, volume, and power were normalized to dollar costs for each option. Total system costs for the various options ranged from a worst case $8 million to a group of four which were all approximately $2 million. A system design was then chosen from the $2 million group and is presented in detail. A ventilation system layout was designed for the MSFC space station mockup which provided comfortable, efficient ventilation of the mockup. A conditioned air distribution system design for the 14-foot diameter modular space station, using the same techniques, is also presented. The tradeoff study resulted in the selection of a system which costs $1.9 million, as compared to the alternate configuration which would have cost $2.6 million.

  15. What Is a Ventilator?

    MedlinePlus

    ... rest of their lives. In these cases, the machines can be used outside of the hospitalin long-term care facilities or at home. A ventilator ... National Institutes of Health Department of Health and Human Services USA.gov

  16. How to Plan Ventilation Systems.

    ERIC Educational Resources Information Center

    Clarke, John H.

    1963-01-01

    Ventilation systems for factory safety demand careful planning. The increased heat loads and new processes of industry have introduced complex ventilation problems in--(1) ventilation supply, (2) duct work design, (3) space requirements, (4) hood face velocities, (5) discharge stacks, and (6) building eddies. This article describes and diagrams…

  17. Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain.

    PubMed

    Del Amo, Eva; Esteva, Cristina; Hernandez-Bou, Susanna; Galles, Carmen; Navarro, Marian; Sauca, Goretti; Diaz, Alvaro; Gassiot, Paula; Marti, Carmina; Larrosa, Nieves; Ciruela, Pilar; Jane, Mireia; Sá-Leão, Raquel; Muñoz-Almagro, Carmen

    2016-01-01

    The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types-defined by MLST-were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination. PMID:26953887

  18. Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain

    PubMed Central

    del Amo, Eva; Esteva, Cristina; Hernandez-Bou, Susanna; Galles, Carmen; Navarro, Marian; Sauca, Goretti; Diaz, Alvaro; Gassiot, Paula; Marti, Carmina; Larrosa, Nieves; Ciruela, Pilar; Jane, Mireia; Sá-Leão, Raquel; Muñoz-Almagro, Carmen

    2016-01-01

    The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types—defined by MLST—were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination. PMID:26953887

  19. Safety and Immunogenicity of Cuban Antipneumococcal Conjugate Vaccine PCV7-TT in Healthy Adults.

    PubMed

    González, Nadezhda; Paredes, Beatriz; Pérez, Sonia; Mirabal, Mayelín; Rivero, Ivonne; González, Carlos A; Díaz, Alina; García, Dagmar; Rodríguez, Laura; Pérez, Amarilis; Soroa, Yamilka; Santana, Darielis; Alvarez, Alina; Valdés, Yury; Vérez, Vicente

    2015-10-01

    INTRODUCTION Pneumococcal infections are a major cause of morbidity and mortality and are associated with considerable economic burden on health systems. To prevent pneumococcal infections, 7-valent conjugate vaccines have been available for over a decade; more recently, 10- and 13-valent conjugate vaccines have been formulated, which are more immunogenic than vaccines with capsular polysaccharides only. In Cuba, a new vaccine candidate has been developed, PCV7-TT, a conjugate of tetanus toxoid with antigens of seven of the serotypes of Streptococcus pneumoniae with highest circulation in Cuba and in the world: 1, 5, 6B, 14, 18C, 19F and 23F. OBJECTIVE Assess the safety of the vaccine candidate PCV7-TT in healthy adults and conduct a preliminary assessment of its immunogenicity. METHODS A phase I, double-blind clinical trial was performed at the National Toxicology Center in Havana, Cuba. Healthy male volunteers aged 18-35 years were randomly assigned to two groups: 20 received the vaccine candidate PCV7-TT and 20 the polyvalent antipneumococcal vaccine PNEUMO-23 used as control, each in a single intramuscular dose. To assess safety, the occurrence of adverse events was monitored for 30 days following inoculation. To explore immunogenicity, concentrations of serotype-specific antibodies was quantified before and 30 days after inoculation, as well titers of opsonophagocytic antibodies. (National Clinical Trial Registry RPCEC00000133) RESULTS Local adverse events were pain, redness, induration, increased sensitivity to touch, and warmth in the injection area. Pain was registered in 70% of individuals who received PCV7-TT and in 75% of those vaccinated with PNEUMO-23. Reported systemic adverse events were general malaise, headache and drowsiness. All adverse events appeared in the first 72 hours post inoculation and lasted no longer than 3 days. One event was reported that was classified as severe in intensity and serious in consequences, but it was unrelated to vaccination appendicitis in one individual inoculated with the control vaccine. Before vaccination, all participants but one had antibody concentrations =0.20 µg/ml against the vaccine strains; after vaccination 100% of individuals were positive and the concentrations of antibodies increased in previously positive volunteers. Some individuals had opsonophagocytic antibodies against serotypes 1, 14, 19F and 23F before vaccination, with highest concentrations against serotypes 14 and 19F. After vaccination, the percent of individuals with opsonophagocytic titers >1:8 for all serotypes in the vaccine was >50% in both groups. CONCLUSIONS A single dose of candidate vaccine PCV7-TT was safe when used in healthy adults. Preliminary results showed that it was able to activate an immune response against the serotypes of Streptococcus pneumoniae used. KEYWORDS Invasive pneumococcal diseases, pneumococcal vaccines, conjugate vaccines, immunization, randomized clinical trial, safety, Cuba. PMID:26947279

  20. ASHRAE and residential ventilation

    SciTech Connect

    Sherman, Max H.

    2003-10-01

    In the last quarter of a century, the western world has become increasingly aware of environmental threats to health and safety. During this period, people psychologically retreated away from outdoors hazards such as pesticides, smog, lead, oil spills, and dioxin to the seeming security of their homes. However, the indoor environment may not be healthier than the outdoor environment, as has become more apparent over the past few years with issues such as mold, formaldehyde, and sick-building syndrome. While the built human environment has changed substantially over the past 10,000 years, human biology has not; poor indoor air quality creates health risks and can be uncomfortable. The human race has found, over time, that it is essential to manage the indoor environments of their homes. ASHRAE has long been in the business of ventilation, but most of the focus of that effort has been in the area of commercial and institutional buildings. Residential ventilation was traditionally not a major concern because it was felt that, between operable windows and envelope leakage, people were getting enough outside air in their homes. In the quarter of a century since the first oil shock, houses have gotten much more energy efficient. At the same time, the kinds of materials and functions in houses changed in character in response to people's needs. People became more environmentally conscious and aware not only about the resources they were consuming but about the environment in which they lived. All of these factors contributed to an increasing level of public concern about residential indoor air quality and ventilation. Where once there was an easy feeling about the residential indoor environment, there is now a desire to define levels of acceptability and performance. Many institutions--both public and private--have interests in Indoor Air Quality (IAQ), but ASHRAE, as the professional society that has had ventilation as part of its mission for over 100 years, is the logical place to provide leadership. This leadership has been demonstrated most recently by the publication of the first nationally recognized standard on ventilation in homes, ASHRAE Standard 62.2-2003, which builds on work that has been part of ASHRAE for many years and will presumably continue. Homeowners and occupants, which includes virtually all of us, will benefit from the application of Standard 62.2 and use of the top ten list. This activity is exactly the kind of benefit to society that the founders of ASHRAE envisioned and is consistent with ASHRAE's mission and vision. ASHRAE members should be proud of their Society for taking leadership in residential ventilation.

  1. Harnessing natural ventilation benefits.

    PubMed

    O'Leary, John

    2013-04-01

    Making sure that a healthcare establishment has a good supply of clean fresh air is an important factor in keeping patients, staff, and visitors, free from the negative effects of CO2 and other contaminants. John O'Leary of Trend Controls, a major international supplier of building energy management solutions (BEMS), examines the growing use of natural ventilation, and the health, energy-saving, and financial benefits, that it offers. PMID:23678661

  2. Purge ventilation operability

    SciTech Connect

    Marella, J.R.

    1995-04-10

    A determination of minimum requirements for purge exhaust ventilation system operability has been performed. HLWE and HLW Regulatory Program personnel have evaluated the various scenarios of equipment conditions and HLWE has developed the requirements for purge exhaust systems. This report is provided to document operability requirements to assist Tank Farm personnel to determine whether a system is operable/inoperable and to define required compensatory actions.

  3. Surfactant and noninvasive ventilation.

    PubMed

    Blennow, Mats; Bohlin, Kajsa

    2015-01-01

    There is mounting evidence that early continuous positive airway pressure (CPAP) from birth is feasible and safe even in very preterm infants. However, many infants will develop respiratory distress syndrome (RDS) and require surfactant treatment. Combining a noninvasive ventilation approach with a strategy for surfactant administration is important to ensure optimal outcome, but questions remain about the optimal timing, mode of delivery and value of predictive tests for surfactant deficiency. Key findings in this review include the following: (1) a noninvasive ventilation strategy with CPAP from birth has a similar outcome to routine intubation in the delivery room; (2) prophylactic surfactant treatment has no advantage over early CPAP with selective surfactant administration; (3) surfactant during CPAP can be safely administered by rapid intubation-extubation (the INSURE method or via tracheal placement of a thin catheter), and (4) predictive tests for surfactant deficiency are being developed and might in future aid in directing surfactant treatment to infants at risk of developing severe RDS. A strategy for surfactant administration should be part of a noninvasive ventilation approach for preterm infants at risk of developing significant RDS. The different methods for surfactant administration during CPAP are reviewed here. PMID:26044100

  4. Home Mechanical Ventilation in Children.

    PubMed

    Preutthipan, Aroonwan

    2015-09-01

    The number of children dependent on home mechanical ventilation has been reported to be increasing in many countries around the world. Home mechanical ventilation has been well accepted as a standard treatment of children with chronic respiratory failure. Some children may need mechanical ventilation as a lifelong therapy. To send mechanically ventilated children back home may be more difficult than adults. However, relatively better outcomes have been demonstrated in children. Children could be safely ventilated at home if they are selected and managed properly. Conditions requiring home ventilation include increased respiratory load from airway or lung pathologies, ventilatory muscle weakness and failure of neurologic control of ventilation. Home mechanical ventilation should be considered when the patient develops progressive respiratory failure or intractable failure to wean mechanical ventilation. Polysomnography or overnight pulse oximetry plus capnometry are used to detect nocturnal hypoventilation in early stage of respiratory failure. Ventilator strategy including non-invasive and invasive approach should be individualized for each patient. The author strongly believes that parents and family members are able to take care of their child at home if they are trained and educated effectively. A good team work with dedicated members is the key factor of success. PMID:26223874

  5. Prospective Evaluation of Subretinal Vessel Location in Polypoidal Choroidal Vasculopathy (PCV) and Response of Hemorrhagic and Exudative PCV to High-Dose Antiangiogenic Therapy (An American Ophthalmological Society Thesis)

    PubMed Central

    Kokame, Gregg T.

    2014-01-01

    Purpose: The purpose of this study was to determine the following: (1) Is polypoidal choroidal vasculopathy (PCV) a subretinal neovascular process, rather than a choroidal vascular anomaly? and (2) Is a higher dose of ranibizumab (2.0 mg/0.05 mL) more effective in treating PCV than the current dose (0.5 mg/0.05 mL) approved for treatment of age-related macular degeneration? Methods: Retrospective evaluation of PCV in 104 eyes of 86 patients was accomplished with use of indocyanine green angiography plus optical coherence tomography to localize the branching vascular network and the polyps. Nineteen eyes of 19 patients with active leaking and exudation underwent a prospective open-label trial of monthly high-dose intravitreal ranibizumab (2.0 mg/0.05 mL). The primary outcome was prevention of major vision loss (≤15 ETDRS letters). Secondary outcomes included adverse events, improved vision, and changes in subretinal hemorrhage, subretinal fluid, macular edema, and polypoidal complexes at 6 months. Results: The PCV vessels were localized beneath the retinal pigment epithelium (RPE) and above Bruch’s membrane in 103 (99%) of 104 eyes. In the high-dose ranibizumab trial at 6 months, none of the patients lost ≥15 letters in visual acuity, and 5 (26%) of 19 gained ≥15 letters. Decreases were noted in subretinal fluid in 14 (82%) of 17 eyes, subretinal hemorrhage in 12 (100%) of 12, RPE detachment in 14 (88%) of 16, macular edema in 11 (92%) of 12, and polyps in 15 (79%) of 19 eyes. Conclusions: PCV vessels are a subtype of subretinal neovascularization located above Bruch’s membrane and below RPE. High-dose ranibizumab (2.0 mg/0.05 mL) decreased exudation and hemorrhage and resulted in significant polyp regression, although branching vascular networks persisted. PMID:25646029

  6. DIFFERENCE IN SEVERITY OF PORCINE CIRCOVIRUS TYPE 2 (PCV2)-INDUCED PATHOLOGICAL LESIONS AND DISEASE BETWEEN LANDRACE AND PIETRAIN PIGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anecdotal information from pig producers and veterinarians in the field suggests that there are genetic differences in susceptibility to porcine circovirus type 2 (PCV2) associated disease (PCVAD) among Landrace and Pietrain breeds. The objective of this study was to determine if a difference exist...

  7. CD40 Ligand and GMCSF Coexpression Enhance the Immune Responses and Protective Efficacy of PCV2 Adenovirus Vaccine.

    PubMed

    Li, Delong; Huang, Yong; Du, Qian; Wang, Zhenyu; Chang, Lingling; Zhao, Xiaomin; Tong, Dewen

    2016-04-01

    Porcine circovirus 2 (PCV2) capsid protein (Cap) is the major structural protein that is responsible for neutralizing antibodies development and protective immunity, thus it is usually used to develop vaccines against porcine circovirus-associated disease (PCVAD). Porcine CD40 ligand (CD40L) and granulocyte-macrophage colony-stimulating factor (GMCSF) have positive immunostimulatory effects on immunocytes and have been applied in vaccine efficacy improvement as attractive adjuvant cytokines, respectively. However, whether these two cytokines can produce synergistic effect in vaccines still need to be further studied. In this study, porcine CD40L and GMCSF were inserted into recombinant adenoviruses to test the immunogenicity of PCV2 adenovirus vaccine in mice. Western blot and indirect immunofluorescence assay showed that Ad-Cap, Ad-CD40L-Cap, Ad-Cap-GMCSF, and Ad-CD40L-Cap-GMCSF were successfully constructed. Indirect ELISA and virus neutralizing assay showed that CD40L and GMCSF could enhance humoral immune responses, and PCV2 Cap-specific antibody titer and neutralizing activities were significantly higher in Ad-CD40L-Cap-GMCSF group than that in the other groups that just inserted either porcine CD40L or GMCSF in recombinant adenoviruses. Moreover, lymphocyte proliferation assay and cytokine release assay showed that CD40L and GMCSF enhanced the cellular immune responses of Ad-Cap, and had synergistic effects in lymphocyte proliferative activities and Th1-type cytokine production. Following PCV2 challenge, the viral loads in lungs of Ad-CD40L-Cap-GMCSF group were significantly lower compared with Ad-Cap, Ad-CD40L-Cap, and Ad-Cap-GMCSF group. Taken together, the results of this study demonstrated that CD40L and GMCSF could synergistically enhance the protective immune responses of PCV2 adenovirus vaccine, which would be used as a potent vaccine for the prevention and control of PCVAD. PMID:26982652

  8. Nursing Education in High Blood Pressure Control. Report of the Task Force on the Role of Nursing in High Blood Pressure Control.

    ERIC Educational Resources Information Center

    National Institutes of Health (DHEW), Bethesda, MD. High Blood Pressure Information Center.

    This curriculum guide on high blood pressure (hypertension) for nursing educators has five sections: (1) Introduction and Objectives provides information regarding the establishment and objectives of the National Task Force on the Role of Nursing in High Blood Pressure Control and briefly discusses nursing's role in hypertension control; (2) Goals

  9. Field measurement of ventilation rates.

    PubMed

    Persily, A K

    2016-02-01

    Ventilation rates have significant impacts on building energy use and indoor contaminant concentrations, making them key parameters in building performance. Ventilation rates have been measured in buildings for many decades, and there are mature measurement approaches available to researchers and others who need to know actual ventilation rates in buildings. Despite the fact that ventilation rates are critical in interpreting indoor concentration measurements, it is disconcerting how few Indoor Air Quality field studies measure ventilation rates or otherwise characterize the ventilation design of the study building(s). This paper summarizes parameters of interest in characterizing building ventilation, available methods for quantifying these parameters, and challenges in applying these methods to different types of buildings and ventilation systems. These parameters include whole-building air change rates, system outdoor air intake rates, and building infiltration rates. Tracer gas methods are reviewed as well as system airflow rate measurements using, for example, duct traverses. Several field studies of ventilation rates conducted over the past 75 years are described to highlight the approaches employed and the findings obtained. PMID:25689218

  10. Laboratory and Industrial Ventilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This handbook supplements the Facilities Engineering Handbook (NHB 7320.1) and provides additional policies and criteria for uniform application to ventilation systems. It expands basic requirements, provides additional design and construction guidance, and places emphasis on those design considerations which will provide for greater effectiveness in the use of these systems. The provisions of this handbook are applicable to all NASA field installations and the Jet Propulsion Laboratory. Since supply of this handbook is limited, abstracts of the portion or portions applicable to a given requirement will be made for the individual specific needs encountered rather than supplying copies of the handbook as has been past practice.

  11. Ventilation in chest trauma

    PubMed Central

    Richter, Torsten; Ragaller, Maximilian

    2011-01-01

    Chest trauma is one important factor for total morbidity and mortality in traumatized emergency patients. The complexity of injury in trauma patients makes it challenging to provide an optimal oxygenation while protecting the lung from further ventilator-induced injury to it. On the other hand, lung trauma needs to be treated on an individual basis, depending on the magnitude, location and type of lung or chest injury. Several aspects of ventilatory management in emergency patients are summarized herein and may give the clinician an overview of the treatment possibilities for chest trauma victims. PMID:21769213

  12. Exposure to environmental stressors result in increased viral load and further reduction of production parameters in pigs experimentally infected with PCV2b.

    PubMed

    Patterson, Robert; Nevel, Amanda; Diaz, Adriana V; Martineau, Henny M; Demmers, Theo; Browne, Christopher; Mavrommatis, Bettina; Werling, Dirk

    2015-06-12

    Porcine circovirus type 2 (PCV2) has been identified as the essential, but not sole, underlying infectious component for PCV-associated diseases (PCVAD). Several co-factors have been suggested to convert an infection with PCV2 into the clinical signs of PCVAD, including co-infection with a secondary pathogen and the genetic background of the pig. In the present study, we investigated the role of environmental stressors in the form of changes in environmental temperature and increased stocking-density on viral load in serum and tissue, average daily weight gain (ADG) and food conversion rate (FCR) of pigs experimentally infected with a defined PCV2b strain over an eight week period. These stressors were identified recently as risk factors leading to the occurrence of severe PCVAD on a farm level. In the current study, PCV2-free pigs were housed in separate, environmentally controlled rooms, and the experiment was performed in a 2×2 factorial design. In general, PCV2b infection reduced ADG and increased FCR, and these were further impacted on by the environmental stressors. Furthermore, all stressors led to an increased viral load in serum and tissue as assessed by qPCR, although levels did not reach statistical significance. Our data suggest that there is no need for an additional pathogen to develop PCVAD in conventional status pigs, and growth retardation and clinical signs can be induced in PCV2 infected pigs that are exposed to environmental stressors alone. PMID:25866129

  13. Exposure to environmental stressors result in increased viral load and further reduction of production parameters in pigs experimentally infected with PCV2b

    PubMed Central

    Patterson, Robert; Nevel, Amanda; Diaz, Adriana V.; Martineau, Henny M.; Demmers, Theo; Browne, Christopher; Mavrommatis, Bettina; Werling, Dirk

    2015-01-01

    Porcine circovirus type 2 (PCV2) has been identified as the essential, but not sole, underlying infectious component for PCV-associated diseases (PCVAD). Several co-factors have been suggested to convert an infection with PCV2 into the clinical signs of PCVAD, including co-infection with a secondary pathogen and the genetic background of the pig. In the present study, we investigated the role of environmental stressors in the form of changes in environmental temperature and increased stocking-density on viral load in serum and tissue, average daily weight gain (ADG) and food conversion rate (FCR) of pigs experimentally infected with a defined PCV2b strain over an eight week period. These stressors were identified recently as risk factors leading to the occurrence of severe PCVAD on a farm level. In the current study, PCV2-free pigs were housed in separate, environmentally controlled rooms, and the experiment was performed in a 2 × 2 factorial design. In general, PCV2b infection reduced ADG and increased FCR, and these were further impacted on by the environmental stressors. Furthermore, all stressors led to an increased viral load in serum and tissue as assessed by qPCR, although levels did not reach statistical significance. Our data suggest that there is no need for an additional pathogen to develop PCVAD in conventional status pigs, and growth retardation and clinical signs can be induced in PCV2 infected pigs that are exposed to environmental stressors alone. PMID:25866129

  14. A novel subunit vaccine co-expressing GM-CSF and PCV2b Cap protein enhances protective immunity against porcine circovirus type 2 in piglets.

    PubMed

    Zhang, Huawei; Qian, Ping; Peng, Bo; Shi, Lin; Chen, Huanchun; Li, Xiangmin

    2015-05-15

    Porcine circovirus type 2 (PCV2) causes porcine circovirus-associated disease. Capsid (Cap) protein of PCV2 is the principal immunogenic protein that induces neutralizing antibodies and protective immunity. GM-CSF is an immune adjuvant that enhances responses to vaccines. In this study, recombinant baculoviruses Ac-Cap and Ac-Cap-GM-CSF expressing the Cap protein alone and co-expressing the Cap protein and porcine GM-CSF, respectively, were constructed successfully. The target proteins were analyzed by western blotting and IFA. Further, these proteins were confirmed by electron microscopy, which showed that Cap proteins could self-assemble into virus-like particles having diameters of 17-25nm. Animal experiments showed that pigs immunized with Cap-GM-CSF subunit vaccine showed significantly higher levels of PCV2-specific antibodies and neutralizing antibodies than pigs immunized with the Cap subunit vaccine and a commercial vaccine (Ingelvac CircoFLEX; P<0.05). After PCV2 wild strain challenged, Pigs receiving the Cap-GM-CSF subunit vaccine showed significantly higher average daily weight gain after wild-type PCV2 challenge than pigs receiving the other three vaccines (P<0.05). None of PCV2 DNA was detected in all immunized animals, except control animals immunized with phosphate-buffered saline. These results indicated that GM-CSF was a powerful immunoadjuvant for PCV2 subunit vaccines because it enhanced humoral immune response and improved immune protection against PCV2 infection in pigs. Thus, the novel Cap-GM-CSF subunit vaccine has the potential to be used as an effective and safe vaccine candidate against PCV2 infection. PMID:25863115

  15. Construction of a novel porcine circovirus type 2 infectious clone as a basis for the development of a PCV2 iDNA vaccine.

    PubMed

    Wang, Wei-Cheng; Zeng, Zhi-Yong; Tang, De-Yuan; Liang, Hai-Ying; Liu, Zhao; Dai, Zhen-Jiang

    2015-08-01

    Porcine circovirus-associated disease is a highly contagious disease that has significant economic consequences. The disease is prevalent in many countries and regions. To generate a genetic marker strain of PCV2, a Sal I restriction enzyme site was inserted into the PCV2 clone as a genetic marker by applying iDNA infectious clone technology. The iDNA represents plasmids that encode the full-length DNA genome of PCV2 assembled in a pcDNA3.1-based vectors. The mutant PCV2 was rescued by transfecting an infectious clone into PK-15 cells and was characterised by an immunoperoxidase monolayer assay (IPMA). The viral genome could be differentiated from the wild-type parent by PCR and restriction fragment length polymorphism (PCR-RFLP). Kunming mice were inoculated with the PCV2 infectious clone or rescued virus via intranasal and intraperitoneal routes. Seroconversion to PCV2-specific antibody appeared in the majority of mice from the two inoculated groups at 7 days postinoculation (DPI), and the specific antibody level was steady for at least 42 days. Viraemia, beginning at 7 DPI and lasting 4 weeks, was detected in the majority of the pigs from the two inoculated groups. The animal experiments revealed that the PCV2 infectious clone and rescued virus both could replicate in mice and induce mice to generate anti-PCV2 antibodies. The infectious clones of PCV2 will be useful for further research investigating a potential tractable iDNA vaccine by reverse genetics technology for attenuated virulance. PMID:25882478

  16. Improved Performance With Ventilation

    NASA Astrophysics Data System (ADS)

    Kawakami, Ellison; Lee, Seung Jae; Karn, Ashish; Hong, Jiarong; Arndt, Roger

    2013-11-01

    Drag reduction and/or speed augmentation of marine vehicles by means of supercavitation is a topic of great interest. During the initial launch of a supercavitating vehicle, ventilation is required to supply an artificial cavity until conditions at which a natural supercavity can be sustained are reached. Various aspects of the flow physics of a supercavitating vehicle have been under investigation for several years at Saint Anthony Falls Laboratory. Both steady flow and simulated flow below a wave train have been studied. Using a high speed camera and the proper software, it is possible to synchronize cavity dimensions with pressure measurements taken inside the cavity to permit an in-depth study of unsteadiness. It was found that flow unsteadiness caused a decrease in the overall length of the supercavity while having only a minimal effect on the maximum diameter. Results regarding supercavity shape, ventilation demand, cavitation parameters and closure methods are reviewed in light of new studies that focused on various closure mechanisms. Sponsored by ONR.

  17. Emplacement Ventilation System

    SciTech Connect

    Vance, Robert W.

    2000-04-05

    The purpose of this analysis is to identify conceptual design options for the emplacement ventilation system, specifically within the emplacement drifts. The designs are based on the Enhanced Design Alternative (EDA) II concept developed during the license application design selection exercise as described in the ''License Application Design Selection Report'' (CRWMS M&O 1999a) and in the emplacement drift ''Ventilation Model'' (CRWMS M&O 2000c). The scope of this analysis, as outlined in the development plan (CRWMS M&O 2000a), includes the following tasks: (1) Description of the air flow path in the emplacement drifts. (2) Examination of the exhaust options for air exiting the emplacement drifts. (3) Examination of the air control options in the emplacement drifts. (4) Discussion of following system components and structures: emplacement isolation doors, portable shadow shield and exhaust main partition. The objective of this analysis is to support site recommendation through input to the system description documents. Off-normal conditions are not discussed in this analysis.

  18. New ventilated isolation cage.

    PubMed

    Cook, R O

    1968-05-01

    A multifunction lid has been developed for a commercially available transparent animal cage which permits feeding, watering, viewing, long-term holding, and local transport of laboratory rodents on experiment while isolating the surrounding environment. The cage is airtight except for its inlet and exhaust high-efficiency particulate air filters, and it is completely steam-sterilizable. Opening of the cage's feed and water ports causes an inrush of high velocity air which prevents back-migration of aerosols and permits feeding and watering while eliminating need for chemical vapor decontamination. Ventilation system design permits the holding in adjacent cages of animals infected with different organisms without danger of cross-contamination; leaves the animal room odor-free; reduces required bedding changes to twice a month or less, and provides investigators with capability to control precisely individual cage ventilation rates. Forty-eight cages can be conveniently placed on a standard NIH "shoebox" cage rack (60 inches wide x 28 inches deep x 74 inches high) fitted with a simple manifold exhaust system. The entire system is mobile, requiring only an electrical power outlet. Principal application of the caging system is in the area of preventing exposure of animal caretakers to pathogenic substances associated with the animal host, and in reducing handling of animals and their exposure to extraneous contamination. PMID:5659368

  19. The KUJ 2000 ventilation system

    SciTech Connect

    Mukka, L.

    1995-12-31

    LKAB has been mining iron ore in northern Sweden for about 100 years and now enters the next century with a major new investment in Kiruna. The underground projects involve construction of a new main haulage level, a new mining system and a new ventilation system. This paper describes the Ventilation Project from the investigation stage through to construction.

  20. Transpired Air Collectors - Ventilation Preheating

    SciTech Connect

    Christensen, C.

    2006-06-22

    Many commercial and industrial buildings have high ventilation rates. Although all that fresh air is great for indoor air quality, heating it can be very expensive. This short (2-page) fact sheet describes a technology available to use solar energy to preheat ventilation air and dramatically reduce utility bills.

  1. Reverse ventilation--perfusion mismatch

    SciTech Connect

    Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

    1984-01-01

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients.

  2. Inhalation therapy in mechanical ventilation

    PubMed Central

    Maccari, Juçara Gasparetto; Teixeira, Cassiano; Gazzana, Marcelo Basso; Savi, Augusto; Dexheimer-Neto, Felippe Leopoldo; Knorst, Marli Maria

    2015-01-01

    Patients with obstructive lung disease often require ventilatory support via invasive or noninvasive mechanical ventilation, depending on the severity of the exacerbation. The use of inhaled bronchodilators can significantly reduce airway resistance, contributing to the improvement of respiratory mechanics and patient-ventilator synchrony. Although various studies have been published on this topic, little is known about the effectiveness of the bronchodilators routinely prescribed for patients on mechanical ventilation or about the deposition of those drugs throughout the lungs. The inhaled bronchodilators most commonly used in ICUs are beta adrenergic agonists and anticholinergics. Various factors might influence the effect of bronchodilators, including ventilation mode, position of the spacer in the circuit, tube size, formulation, drug dose, severity of the disease, and patient-ventilator synchrony. Knowledge of the pharmacological properties of bronchodilators and the appropriate techniques for their administration is fundamental to optimizing the treatment of these patients. PMID:26578139

  3. Ventilation of an hydrofoil wake

    NASA Astrophysics Data System (ADS)

    Arndt, Roger; Lee, Seung Jae; Monson, Garrett

    2013-11-01

    Ventilation physics plays a role in a variety of important engineering applications. For example, hydroturbine ventilation is used for control of vibration and cavitation erosion and more recently for improving the dissolved oxygen content of the flow through the turbine. The latter technology has been the focus of an ongoing study involving the ventilation of an hydrofoil wake to determine the velocity and size distribution of bubbles in a bubbly wake. This was carried out by utilizing particle shadow velocimetry (PSV). This technique is a non-scattering approach that relies on direct in-line volume illumination by a pulsed source such as a light-emitting diode (LED). The data are compared with previous studies of ventilated flow. The theoretical results of Hinze suggest that a scaling relationship is possible that can lead to developing appropriate design parameters for a ventilation system. Sponsored by ONR and DOE.

  4. Evaluation of building ventilation systems

    SciTech Connect

    Hughes, R.T.; O'Brien, D.M.

    1986-04-01

    Over the past several years, NIOSH has responded to health hazard evaluation requests from workers in dozens of office environments. Typically, the employees have complained of headache, eye and upper respiratory tract irritation, dizziness, lethargy and the inability to concentrate. Most often inadequate ventilation has been blamed for these complaints. Of paramount importance in the evaluation and correction of these problems is an effective evaluation of the building's ventilation system. Heating, ventilating and air-conditioning conditions that can cause worker stresses include: migration of odors or chemical hazards between building areas; reentrainment of exhaust from building fume hoods or through heat wheels; buildup of microorganisms in the HVAC system components; and poor odor or environmental control due to insufficient fresh outdoor air or system heating or cooling malfunction. The purpose of this paper is to provide an overview of building ventilation systems, the ventilation problems associated with poorly designed or operating systems, and the methodology for effectively evaluating system performance.

  5. 46 CFR 45.131 - Ventilators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....131 Ventilators. (a) Ventilators passing through superstructures other than enclosed superstructures... enclosed superstructures or trunks must have coamings of steel permanently connected to the deck and...

  6. 46 CFR 45.131 - Ventilators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....131 Ventilators. (a) Ventilators passing through superstructures other than enclosed superstructures... enclosed superstructures or trunks must have coamings of steel permanently connected to the deck and...

  7. 46 CFR 45.131 - Ventilators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....131 Ventilators. (a) Ventilators passing through superstructures other than enclosed superstructures... enclosed superstructures or trunks must have coamings of steel permanently connected to the deck and...

  8. 46 CFR 45.131 - Ventilators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....131 Ventilators. (a) Ventilators passing through superstructures other than enclosed superstructures... enclosed superstructures or trunks must have coamings of steel permanently connected to the deck and...

  9. 46 CFR 45.131 - Ventilators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....131 Ventilators. (a) Ventilators passing through superstructures other than enclosed superstructures... enclosed superstructures or trunks must have coamings of steel permanently connected to the deck and...

  10. Vaccination with a Porcine Reproductive and Respiratory Syndrome (PRRS) Modified Live Virus Vaccine Followed by Challenge with PRRS Virus and Porcine Circovirus Type 2 (PCV2) Protects against PRRS but Enhances PCV2 Replication and Pathogenesis Compared to Results for Nonvaccinated Cochallenged Controls.

    PubMed

    Niederwerder, Megan C; Bawa, Bhupinder; Serão, Nick V L; Trible, Benjamin R; Kerrigan, Maureen A; Lunney, Joan K; Dekkers, Jack C M; Rowland, Raymond R R

    2015-12-01

    Coinfections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) contribute to a group of disease syndromes known as porcine circovirus-associated disease (PCVAD). Presumably, PRRSV infection enhances PCV2 replication as a result of modulation of host immunity. The purpose of this study was to evaluate PCV2 replication and pathogenesis in pigs vaccinated with a PRRS modified live virus (MLV) vaccine and subsequently challenged with a combination of PRRSV and PCV2. During the early postchallenge period, the number of pigs with PRRSV-associated clinical signs was decreased, and average daily gain (ADG) was increased, in the vaccinated group, demonstrating the protective effect of PRRS vaccination. However, during the later postchallenge period, more pigs in the vaccinated group showed increased PCV2 viremia, decreased ADG, increased PCVAD clinical signs, and increased mortality. In this disease model, the early benefits of PRRSV vaccination were outweighed by the later amplification of PCVAD. PMID:26446422

  11. Cardiac gated ventilation

    NASA Astrophysics Data System (ADS)

    Hanson, C. William, III; Hoffman, Eric A.

    1995-05-01

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. We evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50msec scan aperture. Multislice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. We observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a nonfailing model of the heart.

  12. Estimation of Lung Ventilation

    NASA Astrophysics Data System (ADS)

    Ding, Kai; Cao, Kunlin; Du, Kaifang; Amelon, Ryan; Christensen, Gary E.; Raghavan, Madhavan; Reinhardt, Joseph M.

    Since the primary function of the lung is gas exchange, ventilation can be interpreted as an index of lung function in addition to perfusion. Injury and disease processes can alter lung function on a global and/or a local level. MDCT can be used to acquire multiple static breath-hold CT images of the lung taken at different lung volumes, or with proper respiratory control, 4DCT images of the lung reconstructed at different respiratory phases. Image registration can be applied to this data to estimate a deformation field that transforms the lung from one volume configuration to the other. This deformation field can be analyzed to estimate local lung tissue expansion, calculate voxel-by-voxel intensity change, and make biomechanical measurements. The physiologic significance of the registration-based measures of respiratory function can be established by comparing to more conventional measurements, such as nuclear medicine or contrast wash-in/wash-out studies with CT or MR. An important emerging application of these methods is the detection of pulmonary function change in subjects undergoing radiation therapy (RT) for lung cancer. During RT, treatment is commonly limited to sub-therapeutic doses due to unintended toxicity to normal lung tissue. Measurement of pulmonary function may be useful as a planning tool during RT planning, may be useful for tracking the progression of toxicity to nearby normal tissue during RT, and can be used to evaluate the effectiveness of a treatment post-therapy. This chapter reviews the basic measures to estimate regional ventilation from image registration of CT images, the comparison of them to the existing golden standard and the application in radiation therapy.

  13. Exercise Oscillatory Ventilation*

    PubMed Central

    Olson, Lyle J.; Arruda-Olson, Adelaide M.; Somers, Virend K.; Scott, Christopher G.; Johnson, Bruce D.

    2009-01-01

    Background Instability of breathing control due to heart failure (HF) manifests as exercise oscillatory ventilation (EOV). Prior descriptions of patients with EOV have not been controlled and have been limited to subjects with left ventricular ejection fraction (LVEF) of ≤ 0.40. The aim of this study was to compare clinical characteristics including ventilatory responses of subjects with EOV to those of control subjects with HF matched for LVEF. Methods Subjects (n = 47) were retrospectively identified from 1,340 consecutive patients referred for cardiopulmonary exercise testing. Study inclusion required EOV without consideration of LVEF while control subjects (n = 47) were composed of HF patients with no EOV matched for LVEF. Characteristics for each group were summarized and compared. Results For EOV subjects, the mean LVEF was 0.37 (range, 0.11 to 0.70), and 19 subjects (41%) had an LVEF of ≥ 0.40. Compared to control subjects, EOV subjects had increased left atrial dimension, mitral E-wave velocity, and right heart pressures as well as decreased exercise tidal volume response, functional capacity, rest and exercise end-tidal carbon dioxide, and increased ventilatory equivalent for carbon dioxide and dead space ventilation (all p < 0.05). Multivariate analysis demonstrated atrial fibrillation (odds ratio, 6.7; p = 0.006), digitalis therapy (odds ratio, 0.27; p = 0.02), New York Heart Association class (odds ratio, 3.5; p = 0.0006), rest end-tidal carbon dioxide (odds ratio, 0.87; p = 0.005), and peak heart rate (odds ratio, 0.98; p = 0.02) were independently associated with EOV. Conclusions Patients with EOV have clinical characteristics and exercise ventilatory responses consistent with more advanced HF than patients with comparable LV systolic function; EOV may occur in HF patients with an LVEF of ≥ 0.40. PMID:18071013

  14. Dual expression system for assembling phage lambda display particle (LDP) vaccine to porcine Circovirus 2 (PCV2).

    PubMed

    Hayes, Sidney; Gamage, Lakshman N A; Hayes, Connie

    2010-09-24

    The bacteriophage lambda small capsid protein D forms trimers on the phage head. D-fusion polypeptides can be expressed from plasmids in E. coli and remain soluble without aggregation. We report a dual expression system for the display of four immunodominant regions of porcine Circovirus 2 (PCV2) capsid protein (CAP) as D-CAP fusions on lambda display particles (LDP). The LDP-D-CAP preparation proved an effective vaccine in pigs, eliciting both cellular and humoral immune responses and PCV2 neutralizing antibodies. In our dual system wild type D expression was encoded by a heteroimmune infecting phage. The D-fusion protein expression in the infected cells was from an inducible plasmid, enabling the deferral of D-fusion expression until needed. The effective vaccine preparation depended upon the gradient purification of very high concentration, essentially tail-less display particles, not previously described. PMID:20674873

  15. The immunological activity of Lycium barbarum polysaccharides liposome in vitro and adjuvanticity against PCV2 in vivo.

    PubMed

    Bo, Ruonan; Zheng, Sisi; Xing, Jie; Luo, Li; Niu, Yale; Huang, Yee; Liu, Zhenguang; Hu, Yuanliang; Liu, Jiaguo; Wu, Yi; Wang, Deyun

    2016-04-01

    In previous researches, the results showed that Lycium barbarum polysaccharides (LBP) encapsulated with liposome could enhance the immune activity of LBP. Therefore, the present study was designed to investigate the effects of LBPL on spleen lymphocytes and macrophages of mice in vitro and evaluate the immunological adjuvant activity of PCV2 vaccine in vivo. The results showed that LBPL could significantly promote splenocyte proliferation synergistically with PHA or LPS, increase the ratio of CD4(+) to CD8(+) T cells and promote the cytokine secretion of macrophages; enhance PCV2-specific IgG antibody responses, promote Th1 cytokines (IFN-? and TNF-a) and Th2 cytokine (IL-4) secretion. The histomorphological observation of spleen demonstrated that LBPL as a vaccine adjuvant also has good improvement and stimulating effect on the immune organ. PMID:26763175

  16. Epidemiological analysis of pneumococcal serotype 19A in healthy children following PCV7 vaccination.

    PubMed

    Tóthpál, A; Laub, K; Kardos, S; Tirczka, T; Kocsis, A; VAN DER Linden, M; Dobay, O

    2016-05-01

    After the introduction of conjugate vaccines, a strong rearrangement of pneumococcal serotypes was observed globally. Probably most concerning was the emergence of serotype 19A, which has not only high invasive disease potential, but also high antibiotic resistance. In the current study we focused on the increased prevalence of serotype 19A after the PCV vaccination rate became widely used in Hungary. A total of 2262 children aged 3-6 years were screened for pneumococcus carriage using nasal swabs. Children were divided into two groups according to the vaccination rates, low level (group 1) vs. high level (group 2). While the carriage rate did not change over time (average 32·9%), the serotype distribution differed greatly in the two groups. The prevalence of serotype 19A increased >eightfold. Almost all 19A isolates had high-level macrolide resistance and elevated penicillin minimum inhibitory concentrations. Genotyping methods revealed that these new 19A isolates are different from the previously frequent Hungary19A-6 PMEN clone. Both the carriage rate and the overall penicillin and macrolide resistance remained stable over time, but while several serotypes were represented in group 1, serotype 19A alone was clearly dominant in group 2. PMID:26548594

  17. Tubeless translaryngeal superimposed jet ventilation.

    PubMed

    Aloy, A; Schachner, M; Cancura, W

    1991-01-01

    Microsurgical endoscopic interventions of the larynx offer an optimal approach to the surgeon by providing an unrestricted operative field. During such operations, ventilating the patient should in no way be impaired. For this reason we have developed a new type of tubeless jet ventilation which consists of both low-frequency and superimposed high-frequency jet ventilation. In addition, we have integrated two specifically sized jets into a Kleinsasser laryngoscope, placing them at different sites. This technique guarantees adequate ventilation with an oxygen-air blend. Due to the Venturi effect, air and tidal volumes are also enhanced when passing through the external open end of the laryngoscope. This type of tubeless jet ventilation was applied to more than 60 patients, using a prototype jet. Anesthesia consisted of a continuous intravenous administration of propofol, with sufentanil and vecuronium given as needed. Clinical results revealed optimal ventilation of all patients without hypercapnia or other complications. Operative conditions for the surgeon were also very satisfactory. Findings demonstrated that this type of tubeless jet ventilation is also particularly suited for laryngeal laser surgery, thus avoiding flammable tubes and noxious anesthetics. PMID:1768410

  18. Particle Size Concentration Distribution and Influences on Exhaled Breath Particles in Mechanically Ventilated Patients

    PubMed Central

    Chen, Yi-Fang; Huang, Sheng-Hsiu; Wang, Yu-Ling; Chen, Chun-Wan

    2014-01-01

    Humans produce exhaled breath particles (EBPs) during various breath activities, such as normal breathing, coughing, talking, and sneezing. Airborne transmission risk exists when EBPs have attached pathogens. Until recently, few investigations had evaluated the size and concentration distributions of EBPs from mechanically ventilated patients with different ventilation mode settings. This study thus broke new ground by not only evaluating the size concentration distributions of EBPs in mechanically ventilated patients, but also investigating the relationship between EBP level and positive expiratory end airway pressure (PEEP), tidal volume, and pneumonia. This investigation recruited mechanically ventilated patients, with and without pneumonia, aged 20 years old and above, from the respiratory intensive care unit of a medical center. Concentration distributions of EBPs from mechanically ventilated patients were analyzed with an optical particle analyzer. This study finds that EBP concentrations from mechanically ventilated patients during normal breathing were in the range 0.47–2,554.04 particles/breath (0.001–4.644 particles/mL). EBP concentrations did not differ significantly between the volume control and pressure control modes of the ventilation settings in the mechanically ventilated patients. The patient EBPs were sized below 5 µm, and 80% of them ranged from 0.3 to 1.0 µm. The EBPs concentrations in patients with high PEEP (> 5 cmH2O) clearly exceeded those in patients with low PEEP (≤ 5 cmH2O). Additionally, a significant negative association existed between pneumonia duration and EBPs concentration. However, tidal volume was not related to EBPs concentration. PMID:24475230

  19. [Variability of ventilation parameters of home ventilation equipment].

    PubMed

    Fuchs, M; Bickhardt, J; Morgenstern, U

    2002-01-01

    The performance of pressure- and volume controlled ventilators used for invasive and non-invasive ventilation in the home were tested on a patient lung model. In order to determine the influence of tidal volume preset, breathing rate, resistance, compliance and leakage to the variability of delivered tidal volume and peak airway pressure a factorial plan with adapted analysis of variance was used. The influence of tidal volume preset, compliance and leakage to the delivered tidal volume is significant. The peak airway pressure depends hardly on the influence factors. All tested ventilators meet the legal demands. But in some clinical situations there are considerable deviations of the breathing parameters depending on the brand. In conclusion ventilators of different brands are not interchangeable. PMID:12465320

  20. Potential effect of PCV13 introduction on Emergency Department accesses for lower respiratory tract infections in elderly and at risk adults.

    PubMed

    Ansaldi, Filippo; Orsi, Andrea; Trucchi, Cecilia; De Florentiis, Daniela; Ceravolo, Antonella; Coppelli, Martina; Schiaffino, Sergio; Turello, Valter; Rosselli, Roberto; Carloni, Roberto; Icardi, Giancarlo; Study Group, Ligurian Pneumococcal; Canepa, Paola; Sticchi, Laura; Zanetti, Roberta; Cremonesi, Ilaria; Brasesco, PierClaudio; Moscatelli, Paolo

    2015-01-01

    Liguria, an administrative region in northern Italy characterized by a decade of high PCV coverage in paediatric age group, has issued new PCV13 recommendations for free active immunization in adults with risk factors and subjects aged ≥ 70 years old. Main aims of this study are: (1) a descriptive epidemiology of the clinical burden of lower respiratory tract infections (LRTI) in adults ≥18 years of age; and (2) a crossover evaluation of the effect of introduction of PCV13 vaccination in adults aged ≥70 years old, in terms of ED accesses for LRTI, obtained by a Syndrome Surveillance System (SSS). The ED access, chief complaint based SSS will allow an active surveillance of a population cohort of >430 000 individuals resident in Genoa metropolitan area, aged ≥18 years old, for a period of 60 months. During pre-PCV period, annual cumulative incidence of ED accesses for LRTI was equal to 7/1000 and 2% in ≥65 and ≥85 year adults, respectively. In ≥65 years adults, more than 70% of subjects identified by the SSS has at least one risk condition, with a peak of 87% in ≥85 year cohort. New Ligurian PCV13 recommendations can potentially reach more than 75% of ED accesses for LRTI. Data highlights the heavy impact of LRTI in terms of ED accesses, especially in the elderly and subjects with chronic conditions and the usefulness of SSS tool for monitoring PCV vaccination effect. PMID:25483530

  1. Potential effect of PCV13 introduction on Emergency Department accesses for lower respiratory tract infections in elderly and at risk adults.

    PubMed

    Ansaldi, Filippo; Orsi, Andrea; Trucchi, Cecilia; De Florentiis, Daniela; Ceravolo, Antonella; Coppelli, Martina; Schiaffino, Sergio; Turello, Valter; Rosselli, Roberto; Carloni, Roberto; Icardi, Giancarlo; Study Group, Ligurian Pneumococcal; Canepa, Paola; Sticchi, Laura; Zanetti, Roberta; Cremonesi, Ilaria; Brasesco, PierClaudio; Moscatelli, Paolo

    2014-08-19

    Liguria, an administrative region in northern Italy characterized by a decade of high PCV coverage in paediatric age group, has issued new PCV13 recommendations for free active immunization in adults with risk factors and subjects aged ≥ 70 years old. Main aims of this study are: (1) a descriptive epidemiology of the clinical burden of lower respiratory tract infections (LRTI) in adults ≥18 years of age; and (2) a crossover evaluation of the effect of introduction of PCV13 vaccination in adults aged ≥70 years old, in terms of ED accesses for LRTI, obtained by a Syndrome Surveillance System (SSS). The ED access, chief complaint based SSS will allow an active surveillance of a population cohort of>430 000 individuals resident in Genoa metropolitan area, aged ≥18 years old, for a period of 60 months. During pre-PCV period, annual cumulative incidence of ED accesses for LRTI was equal to 7/1000 and 2% in ≥65 and ≥85 year adults, respectively. In ≥65 years adults, more than 70% of subjects identified by the SSS has at least one risk condition, with a peak of 87% in ≥85 year cohort. New Ligurian PCV13 recommendations can potentially reach more than 75% of ED accesses for LRTI. Data highlights the heavy impact of LRTI in terms of ED accesses, especially in the elderly and subjects with chronic conditions and the usefulness of SSS tool for monitoring PCV vaccination effect. PMID:25181315

  2. Potential effect of PCV13 introduction on Emergency Department accesses for lower respiratory tract infections in elderly and at risk adults

    PubMed Central

    Ansaldi, Filippo; Orsi, Andrea; Trucchi, Cecilia; De Florentiis, Daniela; Ceravolo, Antonella; Coppelli, Martina; Schiaffino, Sergio; Turello, Valter; Rosselli, Roberto; Carloni, Roberto; Icardi, Giancarlo; Study Group, Ligurian Pneumococcal; Canepa, Paola; Sticchi, Laura; Zanetti, Roberta; Cremonesi, Ilaria; Brasesco, PierClaudio; Moscatelli, Paolo

    2014-01-01

    Liguria, an administrative region in northern Italy characterized by a decade of high PCV coverage in paediatric age group, has issued new PCV13 recommendations for free active immunization in adults with risk factors and subjects aged ≥ 70 years old. Main aims of this study are: (1) a descriptive epidemiology of the clinical burden of lower respiratory tract infections (LRTI) in adults ≥18 years of age; and (2) a crossover evaluation of the effect of introduction of PCV13 vaccination in adults aged ≥70 years old, in terms of ED accesses for LRTI, obtained by a Syndrome Surveillance System (SSS). The ED access, chief complaint based SSS will allow an active surveillance of a population cohort of >430 000 individuals resident in Genoa metropolitan area, aged ≥18 years old, for a period of 60 months. During pre-PCV period, annual cumulative incidence of ED accesses for LRTI was equal to 7/1000 and 2% in ≥65 and ≥85 year adults, respectively. In ≥65 years adults, more than 70% of subjects identified by the SSS has at least one risk condition, with a peak of 87% in ≥85 year cohort. New Ligurian PCV13 recommendations can potentially reach more than 75% of ED accesses for LRTI. Data highlights the heavy impact of LRTI in terms of ED accesses, especially in the elderly and subjects with chronic conditions and the usefulness of SSS tool for monitoring PCV vaccination effect. PMID:25483530

  3. Determinants of effective ventilation during nasal intermittent positive pressure ventilation.

    PubMed

    Parreira, V F; Jounieaux, V; Delguste, P; Aubert, G; Dury, M; Rodenstein, D O

    1997-09-01

    Our aim was to verify in healthy subjects submitted to nasal intermittent positive pressure ventilation (nIPPV) with a volumetric ventilator on controlled mode, whether changes in ventilator settings (delivered tidal volume (VT), respiratory frequency (fR) and inspiratory flow (V'I) could influence effective minute ventilation (V'E), thus allowing identification of the settings resulting in the highest V'E during nIPPV. We then compared these experimentally obtained "best" settings to those obtained retrospectively in a group of patients submitted to long-term nIPPV for clinical reasons. We studied 10 healthy subjects awake and asleep, and 33 patients with restrictive ventilatory disorders. Changes in delivered V'I (for a constant delivered VT and fR) led to significant changes in V'E. V'E was significantly higher when a given delivered V'E was obtained using higher fR and lower VT than when it was obtained using lower delivered fR and higher VT. Increases in fR generally resulted in increases in V'E. The "best" settings derived from these results were: VT: 13 mL.kg-1 of body weight; fR: 20 breaths.min-1 and V'I: 0.56-0.85 L.s-1. The corresponding average values found in the patient group were: delivered VT: 14 mL.kg-1; fR: 23 breaths.min-1 and delivered V'I: 0.51 L.s-1. Changes in minute ventilation resulting from modifications in ventilator settings can be attributed to the glottic response to mechanical influences. This leads to "ideal" settings quite different from the standard ones in intubated patients. Values derived from nasal intermittent positive pressure ventilation in healthy subjects seem to apply to patients submitted to long-term nasal intermittent positive pressure ventilation. PMID:9311488

  4. 6. VIEW LOOKING SOUTHEAST AT VENTILATION EQUIPMENT IN SOUTH VENTILATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW LOOKING SOUTHEAST AT VENTILATION EQUIPMENT IN SOUTH VENTILATION HOUSE. THIS AIR CONDITIONING SYSTEM WAS INSTALLED BY PARKS-CRAMER COMPANY OF FITCHBURG, MASSACHUSETTS WHEN THE MILL WAS CONSTRUCTED IN 1923-24. ONE AIR WASHER AND FAN ROOM EXTERIOR IS VISIBLE ON THE RIGHT. THE DUCTS FROM BOTH FAN ROOMS (CURVED METAL STRUCTURES AT CENTER AND LEFT OF PHOTO) ARE CONNECTED TO A COMMON AIR SHAFT. - Stark Mill, 117 Corinth Road, Hogansville, Troup County, GA

  5. Simulation and experiment research on the proportional pressure control of water-assisted injection molding

    NASA Astrophysics Data System (ADS)

    Zhou, Hua; Chen, Yinglong; Zhang, Zengmeng; Yang, Huayong

    2012-05-01

    Water-assisted injection molding (WAIM), a newly developed fluid-assisted injection molding technology has drawn more and more attentions for the energy saving, short cooling circle time and high quality of products. Existing research for the process of WAIM has shown that the pressure control of the injecting water is mostly important for the WAIM. However, the proportional pressure control for the WAIM system is quite complex due to the existence of nonlinearities in the water hydraulic system. In order to achieve better pressure control performance of the injecting water to meet the requirements of the WAIM, the proportional pressure control of the WAIM system is investigated both numerically and experimentally. A newly designed water hydraulic system for WAIM is first modeled in AMEsim environment, the load characteristics and the nonlinearities of water hydraulic system are both considered, then the main factors affecting the injecting pressure and load flow rate are extensively studied. Meanwhile, an open-loop model-based compensation control strategy is employed to regulate the water injection pressure and a feedback proportional integrator controller is further adopted to achieve better control performance. In order to verify the AMEsim simulation results WAIM experiment for particular Acrylonitrile Butadiene Styrene (ABS) parts is implemented and the measured experimental data including injecting pressure and flow rate results are compared with the simulation. The good coincidence between experiment and simulation shows that the AMEsim model is accurate, and the tracking performance of the load pressure indicates that the proposed control strategy is effective for the proportional pressure control of the nonlinear WAIM system. The proposed proportional pressure control strategy and the conclusions drawn from simulation and experiment contribute to the application of water hydraulic proportional control and WAIM technology.

  6. Nozzle for discharging ventilation air from a ventilation system

    SciTech Connect

    Elfverson, S.E.

    1986-09-30

    This patent describes a nozzle for discharging ventilation air from a ventilation system, preferably arranged in a vehicle, including at least one outlet housing with a through-flow duct for ventilation air, a fixed plate transverse to the flow duct and rigidly attached to the outlet housing, and a plurality of plates parallel to the fixed plate. These plates are mutually displaceable in a direction transverse to the flow duct under the action of a control lever passing through the plates, the plates being formed with perforation patterns, which in coaction form ventilation ducts through which the ventilation air can flow and in response to the setting of the control lever cause deviation of the flow direction of the ventilation air. Each displaceable plate is formed with a grid cross comprising at least two intersecting bars, of which one bar has a substantially circular cross section, while the other bar has a substantially elliptical cross section and wherein the control lever is adapted to grip round a grid cross, the control lever having two pairs of longitudinal slots. One pair of the slots is adapted to grip without play one of the intersecting bars in each respective grid cross. The other pair of slots comprises a first slot adapted to grip without play the other of the intersecting bars, and a second slot formed with a width disabling engagement with the other of the intersecting bars.

  7. 46 CFR 111.105-21 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation. 111.105-21 Section 111.105-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-21 Ventilation. A ventilation duct which ventilates a...

  8. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 194.20-5 Section 194.20-5 Shipping COAST... Ventilation. (a) Chemical storerooms shall be equipped with a power ventilation system of exhaust type. The... based upon the volume of the compartment. (1) Power ventilation units shall have nonsparking...

  9. 24 CFR 3285.505 - Crawlspace ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Crawlspace ventilation. 3285.505... ventilation. (a) A crawlspace with skirting must be provided with ventilation openings. The minimum net area of ventilation openings must not be less than one square foot (ft.2) for every 150 square feet...

  10. 33 CFR 175.201 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... unless it is equipped with an operable ventilation system that meets the requirements of 33 CFR 183.610... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ventilation. 175.201 Section 175... SAFETY EQUIPMENT REQUIREMENTS Ventilation § 175.201 Ventilation. No person may operate a boat built...

  11. Preoperational test report, vent building ventilation system

    SciTech Connect

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  12. Newer nonconventional modes of mechanical ventilation.

    PubMed

    Singh, Preet Mohinder; Borle, Anuradha; Trikha, Anjan

    2014-07-01

    The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient's demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. Various intensive care units over the world have found these modes to improve patient ventilator synchrony, decrease ventilator days and improve patient safety. The various modes discusses in this review are: Dual control modes (volume assured pressure support, volume support), Adaptive support ventilation, proportional assist ventilation, mandatory minute ventilation, Bi-level airway pressure release ventilation, (BiPAP), neurally adjusted ventilatory assist and NeoGanesh. Their working principles with their advantages and clinical limitations are discussed in brief. PMID:25114434

  13. Equivalence in Ventilation and Indoor Air Quality

    SciTech Connect

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  14. Mechanical ventilation in rural ICUs

    PubMed Central

    Fieselmann, John F; Bock, M Jeanne; Hendryx, Michael S; Wakefield, Douglas; Helms, Charles M; Bentler, Suzanne E

    1999-01-01

    Background: In recent years, rural hospitals have expanded their scope of specialized services, which has led to the development and staffing of rural intensive care units (ICUs). There is little information about the breadth, quality or outcomes of these services. This is particularly true for specialized ICU services such as mechanical ventilation, where little, if any, information exists specifically for rural hospitals. The long-term objectives of this project were to evaluate the quality of medical care provided to mechanically ventilated patients in rural ICUs and to improve patient care through an educational intervention. This paper reports baseline data on patient and hospital characteristics for both rural and rural referral hospitals. Results: Twenty Iowa hospitals were evaluated. Data collected on 224 patients demonstrated a mean age of 70 years and a mean ICU admission Acute Physiology and Chronic Health Evaluation (APACHE) II score of 22, with an associated 36% mortality. Mean length of ICU stay was 10 days, with 7.7 ventilated days. Significant differences were found in both institutional and patient variables between rural referral hospitals and rural hospitals with more limited resources. A subgroup of patients with diagnoses associated with complex ventilation had higher mortality rates than patients without these conditions. Patients who developed nosocomial events had longer mean ventilator and ICU days than patients without nosocomial events. This study also found ICU practices that frequently fell outside the guidelines recommended by a task force describing minimum standards of care for critically ill patients with acute respiratory failure on mechanical ventilation. Conclusions: Despite distinct differences in the available resources between rural referral and rural hospitals, overall mortality rates of ventilated patients are similar. Considering the higher mortality rates observed in patients with complicated medical conditions requiring complex ventilation management, the data may suggest that this subgroup could benefit from treatment at a tertiary center with greater resources and technology. PMID:11056720

  15. Lung ventilation strategies for acute respiratory distress syndrome: a systematic review and network meta-analysis

    PubMed Central

    Wang, Changsong; Wang, Xiaoyang; Chi, Chunjie; Guo, Libo; Guo, Lei; Zhao, Nana; Wang, Weiwei; Pi, Xin; Sun, Bo; Lian, Ailing; Shi, Jinghui; Li, Enyou

    2016-01-01

    To identify the best lung ventilation strategy for acute respiratory distress syndrome (ARDS), we performed a network meta-analysis. The Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, CINAHL, and the Web of Science were searched, and 36 eligible articles were included. Compared with higher tidal volumes with FiO2-guided lower positive end-expiratory pressure [PEEP], the hazard ratios (HRs) for mortality were 0.624 (95% confidence interval (CI) 0.419–0.98) for lower tidal volumes with FiO2-guided lower PEEP and prone positioning and 0.572 (0.34–0.968) for pressure-controlled ventilation with FiO2-guided lower PEEP. Lower tidal volumes with FiO2-guided higher PEEP and prone positioning had the greatest potential to reduce mortality, and the possibility of receiving the first ranking was 61.6%. Permissive hypercapnia, recruitment maneuver, and low airway pressures were most likely to be the worst in terms of all-cause mortality. Compared with higher tidal volumes with FiO2-guided lower PEEP, pressure-controlled ventilation with FiO2-guided lower PEEP and lower tidal volumes with FiO2-guided lower PEEP and prone positioning ventilation are associated with lower mortality in ARDS patients. Lower tidal volumes with FiO2-guided higher PEEP and prone positioning ventilation and lower tidal volumes with pressure-volume (P–V) static curve-guided individual PEEP are potential optimal strategies for ARDS patients. PMID:26955891

  16. Lung ventilation strategies for acute respiratory distress syndrome: a systematic review and network meta-analysis.

    PubMed

    Wang, Changsong; Wang, Xiaoyang; Chi, Chunjie; Guo, Libo; Guo, Lei; Zhao, Nana; Wang, Weiwei; Pi, Xin; Sun, Bo; Lian, Ailing; Shi, Jinghui; Li, Enyou

    2016-01-01

    To identify the best lung ventilation strategy for acute respiratory distress syndrome (ARDS), we performed a network meta-analysis. The Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, CINAHL, and the Web of Science were searched, and 36 eligible articles were included. Compared with higher tidal volumes with FiO2-guided lower positive end-expiratory pressure [PEEP], the hazard ratios (HRs) for mortality were 0.624 (95% confidence interval (CI) 0.419-0.98) for lower tidal volumes with FiO2-guided lower PEEP and prone positioning and 0.572 (0.34-0.968) for pressure-controlled ventilation with FiO2-guided lower PEEP. Lower tidal volumes with FiO2-guided higher PEEP and prone positioning had the greatest potential to reduce mortality, and the possibility of receiving the first ranking was 61.6%. Permissive hypercapnia, recruitment maneuver, and low airway pressures were most likely to be the worst in terms of all-cause mortality. Compared with higher tidal volumes with FiO2-guided lower PEEP, pressure-controlled ventilation with FiO2-guided lower PEEP and lower tidal volumes with FiO2-guided lower PEEP and prone positioning ventilation are associated with lower mortality in ARDS patients. Lower tidal volumes with FiO2-guided higher PEEP and prone positioning ventilation and lower tidal volumes with pressure-volume (P-V) static curve-guided individual PEEP are potential optimal strategies for ARDS patients. PMID:26955891

  17. Ventilation Model and Analysis Report

    SciTech Connect

    V. Chipman

    2003-07-18

    This model and analysis report develops, validates, and implements a conceptual model for heat transfer in and around a ventilated emplacement drift. This conceptual model includes thermal radiation between the waste package and the drift wall, convection from the waste package and drift wall surfaces into the flowing air, and conduction in the surrounding host rock. These heat transfer processes are coupled and vary both temporally and spatially, so numerical and analytical methods are used to implement the mathematical equations which describe the conceptual model. These numerical and analytical methods predict the transient response of the system, at the drift scale, in terms of spatially varying temperatures and ventilation efficiencies. The ventilation efficiency describes the effectiveness of the ventilation process in removing radionuclide decay heat from the drift environment. An alternative conceptual model is also developed which evaluates the influence of water and water vapor mass transport on the ventilation efficiency. These effects are described using analytical methods which bound the contribution of latent heat to the system, quantify the effects of varying degrees of host rock saturation (and hence host rock thermal conductivity) on the ventilation efficiency, and evaluate the effects of vapor and enhanced vapor diffusion on the host rock thermal conductivity.

  18. NINTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    SciTech Connect

    Daugherty, W.

    2014-08-06

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperatures. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The earliest 300 °F GLT O-ring fixture failure was observed at 34 months. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 72 - 96 months, which bounds O-ring temperatures anticipated during storage in K-Area Complex (KAC). Based on expectations that the 200 ºF fixtures will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures, thus providing additional time to failure data. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 54 - 57 months. No additional O-ring failures have been observed since the last interim report was issued. Aging and periodic leak testing will continue for the remaining PCV fixtures. Additional irradiation of several fixtures is recommended to maintain a balance between thermal and radiation exposures similar to that experienced in storage, and to show the degree of consistency of radiation response between GLT and GLT-S O-rings.

  19. Role of Chinese herbal medicinal ingredients in secretion of cytokines by PCV2-induced endothelial cells.

    PubMed

    Hu, Yiyi; He, Kongwang; Wang, Xiaomin

    2016-03-01

    While T-lymphocytes are the major cell type responsible for host responses to a virus (including induction of inflammatory responses to aid in ultimate removal of virus), other cells, including macrophages, epithelial and dendritic cells also have key roles. Endothelial cells also play important roles in physiologic/pathologic processes, like inflammation, during viral infections. As endothelial cells can be activated to release various endogenous compounds, including some cytokines, ex vivo measures of cytokine formation by the cells can be used to indirectly assess any potential endothelial dysfunction in situ. The research presented here sought to investigate potential immunolomodulatory effects of five saponins on endothelial cells: Saikosaponins A (SSA) and D (SSD), Panax Notoginseng Saponin (PNS) and Notoginsenoside R1 (SR1) and Anemoside B4 (AB4). For this, cells (porcine iliac artery endothelial line) were challenged with a virus isolate PCV2-AH for 24 h and then treated with the test saponin (at 1, 5 or 10 μg/ml) for an additional 24 h at 37 °C. The culture supernatants were then collected and analyzed for interleukin (IL)-2, -4 and -10, as well as interferon (IFN)-γ by ELISA. The results revealed that PNS and SR1 inhibited the production of IL-4; PNS, SR1 and AB4 inhibited the secretion of IL-10; SSA, SSD and PNS up-regulated IL-2 expression; SSA and SSD increased the level of IFNγ. All these changes were significant. Taken together, the data suggested these saponins might potentially have a capacity to regulate immune responses in vivo via changes in production of these select cytokines by infected endothelial cells. Nevertheless, the impact of these agents on other key cell types involved in anti-viral responses, including T-lymphocytes, remains to be determined. PMID:25721049

  20. Space Station Environment Control and Life Support System Pressure Control Pump Assembly Modeling and Analysis

    NASA Technical Reports Server (NTRS)

    Schunk, R. Gregory

    2002-01-01

    This paper presents the Modeling and Analysis of the Space Station Environment Control and Life Support System Pressure Control Pump Assembly (PCPA). The contents include: 1) Integrated PCPA/Manifold Analyses; 2) Manifold Performance Analysis; 3) PCPA Motor Heat Leak Study; and 4) Future Plans. This paper is presented in viewgraph form.

  1. Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks in Reduced Gravity

    NASA Technical Reports Server (NTRS)

    Hedayat, Ali; Lopez, Alfredo; Grayson, Gary D.; Chandler, Frank O.; Hastings, Leon J.

    2008-01-01

    A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in low gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-3D software and simulates low gravity extrapolations of engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage Technology Demonstrator (STUSTD) program. Model results illustrate that stable low gravity liquid-gas interfaces are maintained during all phases of the pressure control cycle. Steady and relatively smooth ullage pressurization rates are predicted. This work advances current low gravity CFD modeling capabilities for cryogenic pressure control and aids the development of a low cost CFD-based design process for space hardware.

  2. Improving Urban African Americans’ Blood Pressure Control through Multi-level Interventions in the Achieving Blood Pressure Control Together (ACT) Study: A Randomized Clinical Trial

    PubMed Central

    Ephraim, Patti L.; Hill-Briggs, Felicia; Roter, Debra; Bone, Lee; Wolff, Jennifer; Lewis-Boyer, LaPricia; Levine, David; Aboumatar, Hanan; Cooper, Lisa A; Fitzpatrick, Stephanie; Gudzune, Kimberly; Albert, Michael; Monroe, Dwyan; Simmons, Michelle; Hickman, Debra; Purnell, Leon; Fisher, Annette; Matens, Richard; Noronha, Gary; Fagan, Peter; Ramamurthi, Hema; Ameling, Jessica; Charlston, Jeanne; Sam, Tanyka; Carson, Kathryn A.; Wang, Nae-Yuh; Crews, Deidra; Greer, Raquel; Sneed, Valerie; Flynn, Sarah J.; DePasquale, Nicole; Boulware, L. Ebony

    2014-01-01

    Background Given their high rates of uncontrolled blood pressure, urban African Americans comprise a particularly vulnerable subgroup of persons with hypertension. Substantial evidence has demonstrated the important role of family and community support in improving patients’ management of a variety of chronic illnesses. However, studies of multilevel interventions designed specifically to improve urban African American patients’ blood pressure self-management by simultaneously leveraging patient, family, and community strengths are lacking. Methods/Design We report the protocol of the Achieving Blood Pressure Control Together (ACT) study, a randomized controlled trial designed to study the effectiveness of interventions that engage patient, family, and community-level resources to facilitate urban African American hypertensive patients’ improved hypertension self-management and subsequent hypertension control. African American patients with uncontrolled hypertension receiving health care in an urban primary care clinic will be randomly assigned to receive 1) an educational intervention led by a community health worker alone, 2) the community health worker intervention plus a patient and family communication activation intervention, or 3) the community health worker intervention plus a problem-solving intervention. All participants enrolled in the study will receive and be trained to use a digital home blood pressure machine. The primary outcome of the randomized controlled trial will be patients’ blood pressure control at 12 months. Discussion Results from the ACT study will provide needed evidence on the effectiveness of comprehensive multi-level interventions to improve urban African American patients’ hypertension control. PMID:24956323

  3. Residential ventilation standards scoping study

    SciTech Connect

    McKone, Thomas E.; Sherman, Max H.

    2003-10-01

    The goals of this scoping study are to identify research needed to develop improved ventilation standards for California's Title 24 Building Energy Efficiency Standards. The 2008 Title 24 Standards are the primary target for the outcome of this research, but this scoping study is not limited to that timeframe. We prepared this scoping study to provide the California Energy Commission with broad and flexible options for developing a research plan to advance the standards. This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the ventilation needs of California residences, determining the bases for setting residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and corresponding levels of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

  4. A knowledge- and model-based system for automated weaning from mechanical ventilation: technical description and first clinical application.

    PubMed

    Schädler, Dirk; Mersmann, Stefan; Frerichs, Inéz; Elke, Gunnar; Semmel-Griebeler, Thomas; Noll, Oliver; Pulletz, Sven; Zick, Günther; David, Matthias; Heinrichs, Wolfgang; Scholz, Jens; Weiler, Norbert

    2014-10-01

    To describe the principles and the first clinical application of a novel prototype automated weaning system called Evita Weaning System (EWS). EWS allows an automated control of all ventilator settings in pressure controlled and pressure support mode with the aim of decreasing the respiratory load of mechanical ventilation. Respiratory load takes inspired fraction of oxygen, positive end-expiratory pressure, pressure amplitude and spontaneous breathing activity into account. Spontaneous breathing activity is assessed by the number of controlled breaths needed to maintain a predefined respiratory rate. EWS was implemented as a knowledge- and model-based system that autonomously and remotely controlled a mechanical ventilator (Evita 4, Dräger Medical, Lübeck, Germany). In a selected case study (n = 19 patients), ventilator settings chosen by the responsible physician were compared with the settings 10 min after the start of EWS and at the end of the study session. Neither unsafe ventilator settings nor failure of the system occurred. All patients were successfully transferred from controlled ventilation to assisted spontaneous breathing in a mean time of 37 ± 17 min (± SD). Early settings applied by the EWS did not significantly differ from the initial settings, except for the fraction of oxygen in inspired gas. During the later course, EWS significantly modified most of the ventilator settings and reduced the imposed respiratory load. A novel prototype automated weaning system was successfully developed. The first clinical application of EWS revealed that its operation was stable, safe ventilator settings were defined and the respiratory load of mechanical ventilation was decreased. PMID:23892513

  5. Nasopharyngeal carriage of Streptococcus pneumoniae among children in an urban setting in Brazil prior to PCV10 introduction.

    PubMed

    Menezes, Ana Paula de O; Azevedo, Jailton; Leite, Mariela C; Campos, Leila C; Cunha, Marcelo; Carvalho, Maria da Gloria S; Reis, Mitermayer G; Ko, Albert I; Weinberger, Daniel M; Ribeiro, Guilherme; Reis, Joice N

    2016-02-01

    Information on pneumococcal carriage in the pre-vaccine period is essential to predict and assess the impact of PCV in settings where disease surveillance is particularly difficult. Therefore, we present data on pneumococcal carriage before the introduction of the 10-valent-pneumococcal conjugate vaccine (PCV10) in Brazil. We conducted a prospective study on a cohort of 203 children aged <5 years old, randomly selected in an urban community located in the periphery of the city of Salvador, Brazil and followed them from January/2008 to January/2009. Nasopharyngeal swabs were collected from each child at four times. In total, 721 swabs were collected, yielding a pneumococcal carriage prevalence of 55% (n=398). In multivariate analyses, the variables associated with carriage were having contact with three or more children <2 years old (OR, 2.00; 95% CI 1.33-2.89) and living in a house with an average of 3 residents per room (OR, 1.77; 95% CI 1.05-3.10). Also, white participants were more likely to be protected from colonization (OR, 0.52; 95% CI 0.29-0.93), and prevalence of carriage varied over time, with lower prevalence occurring from February to June (OR, 0.53; 95% CI 0.37-0.78) compared to July to January. Contact with children under 2 years of age and living in crowded housing also were associated with colonization by highly invasive serotypes, although this relationship was not significant. The most prevalent vaccine serotypes were 6A/B (25.4%), 19F (10.1%) and 14 (9.0%), while the most prevalent non-vaccine serotypes were 16F (4.8%), 15B/C (4.5%) and 6C/D (3.5%). Overall, 38.4% (153/398) of the isolates were non-susceptible to penicillin, and of those, 73.8% (113/153) were non-susceptible to trimethoprim/sulfamethoxazole. Colonization rate by PCV10 serotypes was 52.2%. Routine PCV10 vaccination can lead to significant changes in pneumococcal serotypes found in NP colonization, indicating a need for continued monitoring, especially in crowded settings, as occurs in Brazil's slums. PMID:26742946

  6. First description of postweaning multisystemic wasting syndrome (PMWS) in wild boar (Sus scrofa) in Croatia and phylogenetic analysis of partial PCV2 sequences.

    PubMed

    Lipej, Z; Segalés, J; Jemersić, Lorena; Olvera, A; Roić, Besi; Novosel, D; Mihaljević, Z; Manojlović, L

    2007-09-01

    This report describes the first case of postweaning multisystemic wasting syndrome (PMWS) in wild boar in Croatia. During the winter season of 2004, eight wild young piglets (of approximately 2 to 5 months of age) were found dead in a fenced hunting area. Polymerase chain reaction (PCR) was carried out on mesenteric lymph nodes and all animals yielded positive results. In one of these animals diagnosis of PMWS was established based on the three key diagnostic criteria including the clinical manifestation, moderate lymphoid lesions consisting of lymphocyte depletion and granulomatous inflammation, and detection of the presence of PCV2 genome within the lymphoid lesions by in situ hybridisation (ISH). Three additional wild piglets had also mild PMWS-like lesions and a low amount of PCV2 was also found. No PMWS-like lesions or PCV2 genome were detected in the rest of the wild piglets studied. Three PCR-positive isolates were partially sequenced, which confirmed the diagnosis of PCV2 and demonstrated that the three sequences were genetically identical. The phylogenetic analysis of a representative PCV2 isolate indicated that its sequence (DQ875444) is grouped in a separate branch with Hungarian isolate (AY256460) and differs from any of the annotated sequences. PMID:17867466

  7. Cultivation of PCV2 in swine testicle cells using the shell vial technique and monitoring of viral replication by qPCR and RT-qPCR.

    PubMed

    Cruz, Taís F; Araujo, João P

    2014-02-01

    Porcine circovirus type 2 (PCV2) is difficult to isolate. Currently, no published articles have used the shell vial technique to isolate PCV2. In addition, the action of d-glucosamine on swine testicle cells (ST) has not been evaluated properly. Thus, the aim of this study was to determine an optimal concentration of d-glucosamine and to test the shell vial technique for PCV2 propagation in ST cells. The optimal concentration of d-glucosamine was determined to be 100mM. Because PCV2 is noncytopathic, the traditional adsorption was compared to the shell vial technique for 15 passages by qPCR, and RT-qPCR for passages 12 through 15. The quantities of viral DNA (P=0.013) and ORF1-mRNA detected with the shell vial technique were two-fold higher than the obtained with traditional adsorption. The levels of ORF2-mRNA were similar for both methods; however, by passage 15, a six-fold increase in levels was observed with the shell vial technique. Therefore, the shell vial technique was more efficient for the cultivation of PCV2, and qPCR/RT-qPCR can be used to monitor viral replication. In addition, a high viral load (>2.7×10(10) DNA copies/ml) and high levels of viral mRNA expression indicated that the ST cells were persistently infected. PMID:24183921

  8. EIGHTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    SciTech Connect

    Daugherty, W. L.

    2013-09-03

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 61 - 85 months, which is still bounding to O-ring temperatures during storage in KArea Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leaktight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 41 - 45 months. Aging and periodic leak testing will continue for the remaining PCV fixtures.

  9. Acculturation, Medication Adherence, Lifestyle Behaviors, and Blood Pressure Control Among Arab Americans

    PubMed Central

    Tailakh, Ayman K.; Evangelista, Lorraine S.; Morisky, Donald E.; Mentes, Janet C.; Pike, Nancy A.; Phillips, Linda R.

    2015-01-01

    Purpose The aim of this study was to examine the relationship between acculturation, medication adherence, lifestyle behaviors (e.g., physical activity, nutrition, weight control), and blood pressure control among hypertensive Arab Americans. Design The study utilized a cross-sectional descriptive design. A convenience sample of 126 participants completed questionnaires and had measures of blood pressure, weight, and height. Forty-six participants were hypertensive and were included in the analysis. Results Only 29.2% of participants reported high medication adherence. High medication adherence was associated with lower diastolic blood pressure, eating a healthy diet, and following lifestyle modifications. Acculturation was significantly associated with physical activity and body mass index. Conclusion Our study found that acculturated participants were more adherent to medications and physical activity and had better blood pressure control. Further studies are needed to explore how acculturation improves adherence and what factors contribute to better adherence in order to design culturally sensitive interventions. PMID:24848347

  10. Low-g fluid mixing - Further results from the Tank Pressure Control Experiment

    NASA Technical Reports Server (NTRS)

    Bentz, M. D.; Knoll, R. H.; Hasan, M. M.; Lin, C. S.

    1993-01-01

    The Tank Pressure Control Experiment (TPCE) made its first space flight on STS-43 in 1991. Its objective was to test the effectiveness of low-energy axial jet mixing at controlling pressures in low gravity. The experiment used refrigerant 113 at near-saturation conditions, at an 83 percent fill level, to simulate the fluid dynamics and thermodynamics of cryogenic fluids in future space applications. Results from this flight were reported previously. TPCE was again flown in space on STS-52 in 1992, this time primarily to study boiling and related thermal phenomena which will be reported elsewhere. However additional mixing and pressure control data were obtained from the reflight that supplement the data from the first flight.

  11. [Pressure control system for the hermetically sealed cabin of the recoverable satellite].

    PubMed

    Sun, J; Yao, S; Zhang, X; Zhang, F; Zheng, C; Fu, L

    1998-06-01

    There are many precision instruments and equipment for scientific researches and experiments in the hermetically sealed cabin of satellite. Appropriate pressure must be controlled in the cabin in order to ensure the instruments and equipment from the adverse space environment. This paper describes a pressure control system for the hermetically sealed cabin in the recoverable scientific detect and experimental satellite. The cabin pressure is regulated automatically into the specific levels by venting or supplying the air from or to the cabin during launch, on orbit and before reentry of the satellite. The system has low mass, low power consumption and high reliability. It was used successfully in the recoverable satellite first in September 1987 and had been used many times since then. It is the first active pressure control system for the hermetically sealed cabin of the satellite in China. PMID:11541420

  12. Design of industrial ventilation systems

    SciTech Connect

    Alden, J.L.; Kane, J.M.

    1982-01-01

    This latest edition has a title change to reflect an expansion to cover the interrelated areas of general exhaust ventilation and makeup air supply. More coverage is also given the need for energy conservation and for the physical isolation of the workspace from major contaminant generation zones. Excellent and generous illustrative matter is included. Contents, abridged are as follows: flow of fluids; air flow through hoods; pipe resistance; piping design; centrifugal exhaust fans; axial-flow fans; monitoring industrial ventilization systems; isolation; and energy conservation.

  13. Fracture ventilation by surface winds

    NASA Astrophysics Data System (ADS)

    Nachshon, U.; Dragila, M. I.; Weisbrod, N.

    2011-12-01

    Gas exchange between the Earth subsurface and the atmosphere is an important mechanism, affecting hydrological, agricultural and environmental processes. From a hydrological aspect, water vapor transport is the most important process related to Earth-atmosphere gas exchange. In respect to agriculture, gas transport in the upper soil profile is important for soil aeration. From an environmental aspect, emission of volatile radionuclides, such as 3H, 14C and Rd from radioactive waste disposal facilities; volatile organic components from industrial sources and Rn from natural sources, all found in the upper vadose zone, can greatly affect public health when emissions occur in populated areas. Thus, it is vital to better understand gas exchange processes between the Earth's upper crust and atmosphere. Four major mechanisms are known to transfer gases between ground surface and atmosphere: (1) Diffusion; (2) Pressure gradients between ground pores and atmosphere due to changes in barometric pressure; (3) Density-driven gas flow in respond to thermal gradients in the ground; and (4) Winds above the ground surface. Herein, the wind ventilation mechanism is studied. Whereas the wind's impact on ground ventilation was explored in several studies, the physical mechanisms governing this process were hardly quantified or characterized. In this work the physical properties of fracture ventilation due to wind blowing along land surface were explored and quantified. Both field measurements and Hele-Shaw experiments under controlled conditions in the laboratory were used to study this process. It was found that winds in the range of 0.3 m/s result in fracture ventilation down to a depth of 0.2 m. As wind velocity increases, the depth of the ventilation inside the fracture increases respectively, in a linear manner. In addition, the fracture aperture also affects the depth of ventilation, which grows as fracture aperture increases. For the maximal examined aperture of 2 cm and wind velocity of 1.25 m/s, fracture ventilation was deeper than 0.45 m. This study sheds new light on fracture ventilation, showing that moderate winds may increase evaporation and gas exchange between fractured media and the atmosphere. Even though wind impact is limited to the top 0.5 m below the ground surface, it is an important process as most of the biological activities, as well as important hydrological processes occur in this region. Wind effect should be considered when modeling mass and energy balances between the Earth upper crust and atmosphere.

  14. Speech for People with Tracheostomies or Ventilators

    MedlinePlus

    ... ventilator users may sound different. Because of the design of the ventilator, speech occurs when air is ... pathologists (SLPs) The SLP will evaluate the person's thinking and language skills, oral-motor and swallowing functioning, ...

  15. Assessment of ventilation-perfusion mismatching in mechanically ventilated patients.

    PubMed

    Ferrer, M; Zavala, E; Díaz, O; Roca, J; Wagner, P D; Rodriguez-Roisin, R

    1998-11-01

    The multiple inert gas elimination technique (MIGET) is a robust tool to assess both ventilation-perfusion (V'A/Q') distributions and the role of extrapulmonary factors determining arterial oxygenation during spontaneous breathing and in mechanically ventilated patients. Mixed expired gas sampling used in the MIGET is most often obtained from a 10-L mixing box (10L-MB) placed in the expiratory side of the ventilator circuit. Consequently, a considerable increase in the compression volume (Vc) would be expected which, in turn, can give rise to potential errors in the estimation of the effective tidal volume delivered to the patient. The effects of the 10L-MB on the Vc were compared with those produced by a newly designed 1-L, mixing box (IL-MB). At a given peak pressure (Ppeak) within the ventilator circuit, the Vc generated by the 10L-MB was about six-times higher than that produced by the 1L-MB. At a Ppeak =50 cmH2O, the Vc were 377 mL (10L-MB) and 67 mL (1L-MB) (p<0.001). In six patients, the mixed expired partial pressures of the six inert gases simultaneously collected from the two mixing boxes fell on the identity line. V'A/Q' distributions recovered using each of the two mixing boxes were equivalent. With the IL-MB, the effects of different positive end-expiratory pressure levels (0, 6 and 12 cmH2O) on Vc and arterial carbon dioxide tension were negligible. In conclusion, the new 1-L mixing box provides efficient gas mixing and substantially decreases the compression volume. It is, therefore, recommended when studies requiring mixed expired gas are performed in ventilated patients. PMID:9864016

  16. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-1 Power ventilation systems except machinery space ventilation systems. Each power ventilation system must... with the controls for every power ventilation system to which this section is applicable; and (b)...

  17. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-1 Power ventilation systems except machinery space ventilation systems. Each power ventilation system must... with the controls for every power ventilation system to which this section is applicable; and (b)...

  18. Production of inflammatory cytokines in response to diphtheria-pertussis-tetanus (DPT), haemophilus influenzae type b (Hib), and 7-valent pneumococcal (PCV7) vaccines

    PubMed Central

    Kashiwagi, Yasuyo; Miyata, Akiko; Kumagai, Takuji; Maehara, Kouji; Suzuki, Eitarou; Nagai, Takao; Ozaki, Takao; Nishimura, Naoko; Okada, Kenji; Kawashima, Hisashi; Nakayama, Tetsuo

    2014-01-01

    Haemophilus influenzae type b (Hib) and 7-valent pneumococcal (PCV7) vaccines both became recommended in Japan in 2010. In this study, cytokine production was investigated in peripheral blood mononuclear cells (PBMCs) cultures stimulated with diphtheria and tetanus toxoids combined with acellular pertussis vaccine (DPT), Hib, and PCV7 separately or concurrent different combinations, all as final off-the-shelf vaccines without the individual vaccine components as controls. Higher IL-1β levels were produced when cultures were stimulated with PCV than with DPT or Hib, and the concurrent stimulation including PCV7 enhanced the production of IL-1β. Although Hib induced higher levels of IL-6, no significant difference was observed in IL-6 production with the concurrent stimulation. The concurrent stimulation with Hib/PCV7 and DPT/Hib/PCV7 produced higher levels of TNF-α and human G-CSF. Cytokine profiles were examined in serum samples obtained from 61 vaccine recipients with febrile reactions and 18 recipients without febrile illness within 24 h of vaccination. No significant difference was observed in cytokine levels of IL-1β, IL-4, IL-6, IL-10, IL-12, IFN-γ, MIP-1, TNF-α, and prostaglandin E2 (PGE2) in sera between the two groups. However, significantly higher levels of human G-CSF were observed in recipients with febrile illness than in those without febrile reactions. Further investigations of the significance of elevated serum G-CSF levels are required in vaccine recipients with febrile illness. PMID:24589970

  19. Ventilation first for Melbourne hospital.

    PubMed

    2010-11-01

    Infection control is a paramount concern for hospitals worldwide. AECOM engineers in Australia designed the first ever displacement ventilation solution for a Melbourne hospital, researching how materials and systems can assist management of, and reduce, infection transmission within healthcare environments. PMID:21141233

  20. Preventing Ventilation On Sailboard Skegs

    NASA Technical Reports Server (NTRS)

    Caldwell, Richard A.

    1990-01-01

    Design effort undertaken to solve spinout problem plaguing high-performance sailboards. Proposed skeg section designed by use of computer model of pressure field and boundary layer. Prevents ventilation by maintaining attached boundary-layer flow throughout operating environment. Cavitation also avoided by preventing valleys in pressure distribution while skeg operated throughout its range.

  1. Fire Service Training. Ventilation. (Revised).

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Community Colleges, Raleigh.

    One of a set of fourteen outlines for use in a course to train novice firemen, this guide covers ventilation practices and principles. As background, subjects such as heat transmission and building construction are included. The three objectives of this part of the course are to enable the fireman to (1) rescue trapped victims, (2) locate fires as…

  2. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-10 Ventilation. (a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent... with the battery charger so that the battery cannot be charged without ventilation. (c) Large...

  3. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-10 Ventilation. (a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent... with the battery charger so that the battery cannot be charged without ventilation. (c) Large...

  4. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully functioning. Fully functioning for this purpose means operating...

  5. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully functioning. Fully functioning for this purpose means operating...

  6. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Ventilation. 72.05-50 Section 72.05-50 Shipping COAST... Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is used in this section, it shall include trunks, plenums, and any other type of ventilation piping, chambers, or duct work. (b)...

  7. 9 CFR 91.21 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Ventilation. 91.21 Section 91.21... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.21 Ventilation. Each underdeck... mechanical ventilation that will furnish a complete change of air in each compartment every 2 minutes...

  8. 30 CFR 75.333 - Ventilation controls.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Ventilation controls. 75.333 Section 75.333 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.333 Ventilation controls. (a) For purposes of this section, “doors” include...

  9. 14 CFR 125.117 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Ventilation. 125.117 Section 125.117 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....117 Ventilation. Each passenger or crew compartment must be suitably ventilated. Carbon...

  10. 14 CFR 125.117 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Ventilation. 125.117 Section 125.117 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....117 Ventilation. Each passenger or crew compartment must be suitably ventilated. Carbon...

  11. 14 CFR 27.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ventilation. 27.831 Section 27.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 27.831 Ventilation. (a) The ventilating system...

  12. 14 CFR 125.117 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Ventilation. 125.117 Section 125.117 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....117 Ventilation. Each passenger or crew compartment must be suitably ventilated. Carbon...

  13. 14 CFR 125.117 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ventilation. 125.117 Section 125.117 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....117 Ventilation. Each passenger or crew compartment must be suitably ventilated. Carbon...

  14. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ventilation. 25.831 Section 25.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation. (a) Under normal operating conditions...

  15. 14 CFR 125.117 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Ventilation. 125.117 Section 125.117 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....117 Ventilation. Each passenger or crew compartment must be suitably ventilated. Carbon...

  16. 14 CFR 27.831 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ventilation. 27.831 Section 27.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 27.831 Ventilation. (a) The ventilating system...

  17. 21 CFR 868.5895 - Continuous ventilator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Continuous ventilator. 868.5895 Section 868.5895...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5895 Continuous ventilator. (a) Identification. A continuous ventilator (respirator) is a device intended to mechanically control or...

  18. 21 CFR 868.5895 - Continuous ventilator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Continuous ventilator. 868.5895 Section 868.5895...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5895 Continuous ventilator. (a) Identification. A continuous ventilator (respirator) is a device intended to mechanically control or...

  19. HIV Infection and the Epidemiology of Invasive Pneumococcal Disease (IPD) in South African Adults and Older Children Prior to the Introduction of a Pneumococcal Conjugate Vaccine (PCV)

    PubMed Central

    Meiring, Susan; Cohen, Cheryl; Quan, Vanessa; de Gouveia, Linda; Feldman, Charles; Karstaedt, Alan; Klugman, Keith P.; Madhi, Shabir A.; Rabie, Helene; Sriruttan, Charlotte; von Gottberg, Anne

    2016-01-01

    Introduction Streptococcus pneumoniae is the commonest cause of bacteremic pneumonia among HIV-infected persons. As more countries with high HIV prevalence are implementing infant pneumococcal conjugate vaccine (PCV) programs, we aimed to describe the baseline clinical characteristics of adult invasive pneumococcal disease (IPD) in the pre-PCV era in South Africa in order to interpret potential indirect effects following vaccine use. Methods National, active, laboratory-based surveillance for IPD was conducted in South Africa from 1 January 2003 through 31 December 2008. At 25 enhanced surveillance (ES) hospital sites, clinical data, including HIV serostatus, were collected from IPD patients ≥ 5 years of age. We compared the clinical characteristics of individuals with IPD in those HIV-infected and -uninfected using multivariable analysis. PCV was introduced into the routine South African Expanded Program on Immunization (EPI) in 2009. Results In South Africa, from 2003–2008, 17 604 cases of IPD occurred amongst persons ≥ 5 years of age, with an average incidence of 7 cases per 100 000 person-years. Against a national HIV-prevalence of 18%, 89% (4190/4734) of IPD patients from ES sites were HIV-infected. IPD incidence in HIV-infected individuals is 43 times higher than in HIV-uninfected persons (52 per 100 000 vs. 1.2 per 100 000), with a peak in the HIV-infected elderly population of 237 per 100 000 persons. Most HIV-infected individuals presented with bacteremia (74%, 3 091/4 190). HIV-uninfected individuals were older; and had more chronic conditions (excluding HIV) than HIV-infected persons (39% (210/544) vs. 19% (790/4190), p<0.001). During the pre-PCV immunization era in South Africa, 71% of serotypes amongst HIV-infected persons were covered by PCV13 vs. 73% amongst HIV-uninfected persons, p = 0.4, OR 0.9 (CI 0.7–1.1). Conclusion Seventy to eighty-five percent of adult IPD in the pre-PCV era were vaccine serotypes and 93% of cases had recognized risk factors (including HIV-infection) for pneumococcal vaccination. These data describe the epidemiology of IPD amongst HIV-infected and -uninfected adults during the pre-PCV era and provide a robust baseline to calculate the indirect effect of PCV in future studies. PMID:26863135

  20. SEVENTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    SciTech Connect

    Daugherty, W.

    2012-08-30

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 54-72 months, which is still bounding to O-ring temperatures during storage in K-Area Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 30 - 36 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the O-rings displayed a compression set ranging from 51 – 96%. This is greater than seen to date for any packages inspected during KAC field surveillance (24% average). For GLT O-rings, separate service life estimates have been made based on the O-ring fixture leak test data and based on compression stress relaxation (CSR) data. These two predictive models show reasonable agreement at higher temperatures (350 – 400 ºF). However, at 300 ºF, the room temperature leak test failures to date experienced longer aging times than predicted by the CSRbased model. This suggests that extrapolations of the CSR model predictions to temperatures below 300 ºF will provide a conservative prediction of service life relative to the leak rate criterion. Leak test failure data at lower temperatures are needed to verify this apparent trend. Insufficient failure data exist currently to perform a similar comparison for GLT-S O-rings. Aging and periodic leak testing will continue for the remaining PCV O-ring fixtures.

  1. The basis and basics of mechanical ventilation.

    PubMed

    Bone, R C; Eubanks, D H

    1991-06-01

    The development of mechanical ventilators and the procedures for their application began with the simple foot pump developed by Fell O'Dwyer in 1888. Ventilators have progressed through three generations, beginning with intermittent positive pressure breathing units such as the Bird and Bennett device in the 1960s. These were followed by second-generation units--represented by the Bennett MA-2 ventilator--in the 1970s, and the third-generation microprocessor-controlled units of today. During this evolutionary process clinicians recognized Types I and II respiratory failure as being indicators for mechanical ventilatory support. More recently investigators have expanded, clarified, and clinically applied the physiology of the work of breathing (described by Julius Comroe and other pioneers) to muscle fatigue, requiring ventilatory support. A ventilator classification system can help the clinician understand how ventilators function and under what conditions they may fail to operate as desired. Pressure-support ventilation is an example of how industry has responded to a clinical need--that is, to unload the work of breathing. All positive pressure ventilators generate tidal volumes by using power sources such as medical gas cylinders, air compressors, electrically driven turbines, or piston driven motors. Positive end-expiratory pressures, synchronized intermittent mandatory ventilation, pressure support ventilation, pressure release ventilation, and mandatory minute ventilation, are examples of the special functions available on modern ventilators. Modern third-generation ventilators use microprocessors to control operational functions and monitors. Because these units have incorporated the experience learned from earlier ventilators, it is imperative that clinicians understand basic ventilator operation and application in order to most effectively prescribe and assess their use. PMID:2036934

  2. Chronic ventilator dependence in elderly patients.

    PubMed

    Kleinhenz, M E; Lewis, C Y

    2000-11-01

    Long-term ventilator dependence is the need for mechanical ventilation for more than 6 h/d for more than 21 days. Long-term ventilator dependence complicates 9% to 20% of the episodes of mechanical ventilation treated in the intensive care units of acute care hospitals; it is associated with an average mortality rate of 40%. Unlike acute respiratory failure, the risk for which does not increase with age, long-term ventilator dependence falls disproportionately to patients aged 70 years or older. During the past 2 decades, a profusion of care sites for patients with long-term ventilator dependence has evolved, largely as the product of the prospective payment system for health services introduced by the Health Care Financing Administration in 1983. The outcome of long-term ventilator dependence in elderly patients across this health care continuum is addressed. PMID:10984753

  3. Blood Pressure Control in Hypertensive Patients in the "Hiperdia Program": A Territory-Based Study

    PubMed Central

    de Souza, Clarita Silva; Stein, Airton Tetelbom; Bastos, Gisele Alsina Nader; Pellanda, Lucia Campos

    2014-01-01

    Background Systemic hypertension is highly prevalent and an important risk factor for cardiovascular events. Blood pressure control in hypertensive patients enrolled in the Hiperdia Program, a program of the Single Health System for the follow-up and monitoring of hypertensive patients, is still far below the desired level. Objective To describe the epidemiological profile and to assess blood pressure control of patients enrolled in Hiperdia, in the city of Novo Hamburgo (State of Rio Grande do Sul, Brazil). Methods Cross-sectional study with a stratified cluster random sample, including 383 adults enrolled in the Hiperdia Program of the 15 Basic Health Units of the city of Porto Alegre, conducted between 2010 and 2011. Controlled blood pressure was defined as ≤140 mmHg × 90 mmHg. The hypertensive patients were interviewed and their blood pressure was measured using a calibrated aneroid device. Prevalence ratios (PR) with 95% confidence interval, Wald's χ2 test, and simple and multiple Poisson regression were used in the statistical analysis. Results The mean age was 63 ± 10 years, and most of the patients were females belonging to social class C, with a low level of education, a sedentary lifestyle, and family history positive for systemic hypertension. Diabetes mellitus (DM) was observed in 31%; adherence to the antihypertensive treatment in 54.3%; and 33.7% had their blood pressure controlled. DM was strongly associated with inadequate BP control, with only 15.7% of the diabetics showing BP considered as controlled. Conclusion Even for hypertensive patients enrolled in the Hiperdia Program, BP control is not satisfactorily reached or sustained. Diabetic hypertensive patients show the most inappropriate BP control. PMID:25004419

  4. Speed and pressure control system design and simulation for a compression press

    SciTech Connect

    Floersch, R.H.

    1981-04-01

    A new system design using closed loop control on the hydraulic system on compression transfer presses used to make filled elastomer parts will improve accuracy and repeatability of speed and pressure control during critical pre-cure forming stages. The present open loop system does not provide the control necessary to mold repeatably the filled elastomer products. These products form with great difficulty because of high loading levels of filler materials. The new system will mean improved wall thickness control of loaded elastomer parts, thus reducing the amount of scrap caused by wall thickness variations.

  5. Insole with pressure control and tissue neoformation induction systems for diabetic foot.

    PubMed

    do Carmo Dos Reis, Maria; Soares, Fabiano A; da Rocha, Adson F; Carvalho, Joao L A; Rodrigues, Suélia S R

    2010-01-01

    This article presents the development of a prototype insole derived from natural rubber from Hevea brasiliensis, equipped with pressure control and capable of neoformation of tissue for people who have diabetic foot. The active element of this insole is the electronic circuit that monitors the plantar pressure. In addition, on the present stage of the research, a signal irradiating cell is used based on the principle of tissue regeneration using laser. This project proposes a "smart" insole prototype with a pressure monitoring system and an electronic system for tissue regeneration, which will open a new approach in an attempt to solve the problem of diabetic foot. PMID:21097333

  6. Performance Improvement of Scroll Compressors for Air Conditioners Using a Back-Pressure Control System

    NASA Astrophysics Data System (ADS)

    Tsubono, Isamu; Hayase, Isao; Takebayashi, Masahiro; Inaba, Koichi; Sekiguchi, Koichi; Shimada, Atsushi

    The performance of scroll compressors using the new back-pressure control system is much better than that of conventional compressors, especially under the cooling half-load condition at a higher suction pressure and a lower discharge pressure. Optimum performance is obtained under all operating conditions by varying the backpr-pessure at a level that is a constant amount above the suction pressure. This reduces friction at the thrust bearing between the orbiting and fixed scrolls. In this paper, we discuss the theoretical analysis of backpressure control method.

  7. Summary of human responses to ventilation

    SciTech Connect

    Seppanen, Olli A.; Fisk, William J.

    2004-06-01

    The effects of ventilation on indoor air quality and health is a complex issue. It is known that ventilation is necessary to remove indoor generated pollutants from indoor air or dilute their concentration to acceptable levels. But, as the limit values of all pollutants are not known, the exact determination of required ventilation rates based on pollutant concentrations and associated risks is seldom possible. The selection of ventilation rates has to be based also on epidemiological research (e.g. Seppanen et al., 1999), laboratory and field experiments (e.g. CEN 1996, Wargocki et al., 2002a) and experience (e.g. ECA 2003). Ventilation may also have harmful effects on indoor air quality and climate if not properly designed, installed, maintained and operated as summarized by Seppdnen (2003). Ventilation may bring indoors harmful substances that deteriorate the indoor environment. Ventilation also affects air and moisture flow through the building envelope and may lead to moisture problems that deteriorate the structures of the building. Ventilation changes the pressure differences over the structures of building and may cause or prevent the infiltration of pollutants from structures or adjacent spaces. Ventilation is also in many cases used to control the thermal environment or humidity in buildings. Ventilation can be implemented with various methods which may also affect health (e.g. Seppdnen and Fisk, 2002, Wargocki et al., 2002a). In non residential buildings and hot climates, ventilation is often integrated with air-conditioning which makes the operation of ventilation system more complex. As ventilation is used for many purposes its health effects are also various and complex. This paper summarizes the current knowledge on positive and negative effects of ventilation on health and other human responses. The focus of the paper is on office-type working environment and residential buildings. In the industrial premises the problems of air quality are usually more complex and case specific. They are subject to occupational safety legislation and not discussed here.

  8. Flow transport and gas mixing during invasive high frequency oscillatory ventilation.

    PubMed

    Alzahrany, Mohammed; Banerjee, Arindam; Salzman, Gary

    2014-06-01

    A large Eddy simulation (LES) based computational fluid dynamics study was performed to investigate gas transport and mixing in patient specific human lung models during high frequency oscillatory ventilation. Different pressure-controlled waveforms (sinusoidal, exponential and square) and ventilator frequencies (15, 10 and 6Hz) were used (tidal volume=50mL). The waveforms were created by solving the equation of motion subjected to constant lung wall compliance and flow resistance. Simulations were conducted with and without endotracheal tube to understand the effect of invasive management device. Variation of pressure-controlled waveform and frequency exhibits significant differences on counter flow pattern, which could lead to a significant impact on the gas mixing efficiency. Pendelluft-like flow was present for the sinusoidal waveform at all frequencies but occurred only at early inspiration for the square waveform at highest frequency. The square waveform was most efficient for gas mixing, resulting in the least wall shear stress on the lung epithelium layer thereby reducing the risk of barotrauma to both airways and the alveoli for patients undergoing therapy. PMID:24656889

  9. A brief review: liquid ventilation.

    PubMed

    Shaffer, T H

    1987-03-01

    The liquid-filled lung preparation has provided physiologists with a unique technique for varying the physical properties of respiratory media and studying their effect on basic pulmonary processes. More recently, liquid breathing, ventilation of the lungs with an oxygenated fluid, has extended the applicability of the liquid-filled lung to include a wide variety of environmental and clinical research areas. This article is an account of the history of liquid breathing based on a review of 60 publications dating back to 1920. The physiologic status of this experimental preparation has continuously advanced due to technical changes in experimental approach and improved understanding of the implications of fluid breathing on overall systemic physiology. In this regard, the evolution of the liquid breathing concept from the saline-filled lung to ventilation with inert liquids is presented. Emphasis is placed on how liquid breathing can be used as an effective research tool for expanding our understanding of normal respiratory physiology and how this technique may be of benefit to other areas of science. Finally, like most techniques in biological investigations, liquid ventilation has certain limitations. Therefore, this review summarizes the rationale behind various experimental approaches, the nature and tractability of limitations, and the results which can be safely drawn from experimental studies to date. PMID:3554691

  10. [Economic impact of Circovac® - vaccination in a PCV2 subclinically infected farm in Switzerland on performance parameters].

    PubMed

    Sidler, X; Kurmann, J; Brugnera, E; Sydler, T

    2012-10-01

    Vaccination of dams in a PCV2 subclinically infected farm 2 and 4 weeks before insemination, with a booster at 12 weeks of gestation did not influence fertility parameters of the dams. However, growth parameters of offspring of vaccinated sows improved significantly (+ 51 g/d), resulting in a shorter growing period of 9 days and a massively improved economy. Mortality of weaners and fattening pigs was not significantly influenced by dam vaccination. Nevertheless, compared to a period of 6 months before vaccination, the mortality rate declined in the weaning period by 0,3 % and in the fattening period by 5,5 %. The Return on Investment (ROI) was calculated with 1:9.5. Even, the historically low pork prices in 2011 led to a ROI of 1:7. PMID:23027512

  11. ALTERNATIVE PROCESSING TECHNOLOGIES TO REDUCE TRANS ACID CONTENTS OF FOOD OILS: INTERESTERIFICATION, PLANT BREEDING, AND PRESSURE CONTROLLED HYDROGENATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternative processing strategies to reduce trans acid contents of food oils include interesterification, genetic and plant breeding for triglyceride and fatty acid composition and pressure controlled hydrogenation. This paper will review research in these areas. Random interesterification of liqu...

  12. Baculovirus expression of the N-terminus of porcine heat shock protein Gp96 improves the immunogenicity of recombinant PCV2 capsid protein.

    PubMed

    Zhu, Xuejiao; Liu, Jie; Bai, Juan; Liu, Panrao; Zhang, Tingjie; Jiang, Ping; Wang, Xianwei

    2016-04-01

    Porcine circovirus type 2 (PCV2) causes significant economic losses to the swine industry worldwide. Heat shock proteins (Hsps) can be used as modulators to enhance both innate and adaptive immune responses. In the present study, recombinant baculoviruses expressing the PCV2Cap protein and the N-terminal 22-370 amino acids of porcine Gp96 (Gp96N), Hsp90, and Hsp70 (rBac-cap/Gp96N, rBac-cap/Hsp90 and rBac-cap/Hsp70, respectively) were constructed and the immune responses were examined in mice and piglets. The mouse experiments showed that rBac-cap/Gp96N increased the titers of specific anti-PCV2 neutralizing antibodies, proliferative responses of peripheral blood mononuclear cells (PBMCs) and IFN-γ levels compared to rBac-cap/Hsp90, rBac-cap/Hsp70, or rBac-cap. The pig experiments showed that the levels of anti-PCV2 antibody, proliferative responses of PBMCs, and IFN-γ in the rBac-cap/Gp96N groups were increased compared to those in rBac-cap group. There were no clear clinical signs of infection following PCV2 challenge in pigs inoculated with recombinant rBac-cap/Gp96N and rBac-cap, and the relative daily weight gains were higher than those in the challenge control (CC) group. The pathological lesions, extent of viremia, and viral loads of the vaccinated groups were milder than those in the CC group. Meanwhile, the extent of viremia and viral load present in the rBac-cap/Gp96N group were significantly lower than those in the rBac-cap group. These results indicated that porcine Gp96N effectively increased the humoral and cell-mediated immune responses of PCV2Cap. Gp96N presents an attractive adjuvant or immunotargeting strategy to enhance the protective efficacy of PCV2 subunit vaccines in swine. PMID:26826323

  13. Distance to health services affects local-level vaccine efficacy for pneumococcal conjugate vaccine (PCV) among rural Filipino children

    PubMed Central

    Root, Elisabeth Dowling; Lucero, Marilla; Nohynek, Hanna; Anthamatten, Peter; Thomas, Deborah S. K.; Tallo, Veronica; Tanskanen, Antti; Quiambao, Beatriz P.; Puumalainen, Taneli; Lupisan, Socorro P.; Ruutu, Petri; Ladesma, Erma; Williams, Gail M.; Riley, Ian; Simões, Eric A. F.

    2014-01-01

    Pneumococcal conjugate vaccines (PCVs) have demonstrated efficacy against childhood pneumococcal disease in several regions globally. We demonstrate how spatial epidemiological analysis of a PCV trial can assist in developing vaccination strategies that target specific geographic subpopulations at greater risk for pneumococcal pneumonia. We conducted a secondary analysis of a randomized, placebo-controlled, double-blind vaccine trial that examined the efficacy of an 11-valent PCV among children less than 2 y of age in Bohol, Philippines. Trial data were linked to the residential location of each participant using a geographic information system. We use spatial interpolation methods to create smoothed surface maps of vaccination rates and local-level vaccine efficacy across the study area. We then measure the relationship between distance to the main study hospital and local-level vaccine efficacy, controlling for ecological factors, using spatial autoregressive models with spatial autoregressive disturbances. We find a significant amount of spatial variation in vaccination rates across the study area. For the primary study endpoint vaccine efficacy increased with distance from the main study hospital from −14% for children living less than 1.5 km from Bohol Regional Hospital (BRH) to 55% for children living greater than 8.5 km from BRH. Spatial regression models indicated that after adjustment for ecological factors, distance to the main study hospital was positively related to vaccine efficacy, increasing at a rate of 4.5% per kilometer distance. Because areas with poor access to care have significantly higher VE, targeted vaccination of children in these areas might allow for a more effective implementation of global programs. PMID:24550454

  14. Five-year blood pressure control and mortality following health education for hypertensive patients.

    PubMed Central

    Morisky, D E; Levine, D M; Green, L W; Shapiro, S; Russell, R P; Smith, C R

    1983-01-01

    Three health education interventions for urban poor hypertensive patients were introduced sequentially in a randomized factorial design: 1) an exit interview to increase understanding of and compliance with the prescribed regimen; 2) a home visit to encourage a family member to provide support for the patient's regimen; and 3) invitations to small group sessions to increase the patient's confidence and ability to manage his/her problem. Previous evaluation of the initial two-year experience demonstrated a positive effect of the educational program on compliance with the medical treatment and blood pressure control. Data accumulated over an additional three years, including mortality analysis, are now presented. The study group consisted of the same cohort of 400 ambulatory hypertensive outpatients in the eight experimental and control groups. The five-year analysis shows a continuing positive effect on appointment keeping, weight control, and blood pressure control. All-cause life table mortality rate was 57.3 per cent less for the experimental group compared to the control group (12.9/100 vs 30.2/100, p less than .05), while the hypertension-related mortality rate was 53.2 per cent less (8.9/100 vs 19.0/100, p less than .01). The results from this longitudinal study provide evidence to encourage health practitioners to utilize such educational programs in the long-term management and control of high blood pressure. PMID:6849473

  15. Endothelin, sex, and pregnancy: unique considerations for blood pressure control in females.

    PubMed

    Gillis, Ellen E; Sasser, Jennifer M; Sullivan, Jennifer C

    2016-04-15

    Endothelin-1 (ET-1) is a potent vasoconstrictor, and dysregulation of the endothelin (ET) system has been implicated in the development of hypertension. Sex differences in the ET system have been identified in ET receptor expression and activation, levels of ET-1, and downstream mediators of the ET system. More specifically, males have greater ET-1/ETAreceptor activation, whereas females exhibit greater ETBreceptor activation. These differences have been suggested to contribute to the sex differences observed in blood pressure control, with greater ETBreceptor activation in females potentially acting as an important pathway contributing to the lower prevalence of hypertension in young females compared with age-matched males. This hypothesis is further supported by studies in pregnancy; the role of the ET system is enhanced during pregnancy, with dysregulation of the ET system resulting in preeclampsia. Further research is necessary to elucidate the relative roles of the ET system in blood pressure control in both sexes and to further explore the potential benefits of pharmacological ET blockade in women. PMID:26936781

  16. Development of a Residential Integrated Ventilation Controller

    SciTech Connect

    Staff Scientist; Walker, Iain; Sherman, Max; Dickerhoff, Darryl

    2011-12-01

    The goal of this study was to develop a Residential Integrated Ventilation Controller (RIVEC) to reduce the energy impact of required mechanical ventilation by 20percent, maintain or improve indoor air quality and provide demand response benefits. This represents potential energy savings of about 140 GWh of electricity and 83 million therms of natural gas as well as proportional peak savings in California. The RIVEC controller is intended to meet the 2008 Title 24 requirements for residential ventilation as well as taking into account the issues of outdoor conditions, other ventilation devices (including economizers), peak demand concerns and occupant preferences. The controller is designed to manage all the residential ventilation systems that are currently available. A key innovation in this controller is the ability to implement the concept of efficacy and intermittent ventilation which allows time shifting of ventilation. Using this approach ventilation can be shifted away from times of high cost or high outdoor pollution towards times when it is cheaper and more effective. Simulations, based on the ones used to develop the new residential ventilation requirements for the California Buildings Energy code, were used to further define the specific criteria and strategies needed for the controller. These simulations provide estimates of the energy, peak power and contaminant improvement possible for different California climates for the various ventilation systems. Results from a field test of the prototype controller corroborate the predicted performance.

  17. Passive ventilation for residential air quality control

    SciTech Connect

    Axley, J.

    1999-07-01

    Infiltration has long served the residential ventilation needs in North America. In Northern Europe it has been augmented by purpose-provided natural ventilation systems--so-called passive ventilation systems--to better control moisture problems in dwellings smaller than their North American counterparts and in a generally wetter climate. The growing concern for energy consumption, and the environmental impacts associated with it, has however led to tighter residential construction standards on both continents and as a result problems associated with insufficient background ventilation have surfaced. Can European passive ventilation systems be adapted for use in North American dwellings to provide general background ventilation for air quality control? This paper attempts to answer this question. The configuration, specifications and performance of the preferred European passive ventilation system--the passive stack ventilation (PSV) system--will be reviewed; innovative components and system design strategies recently developed to improve the traditional PSV system performance will be outlined; and alternative system configurations will be presented that may better serve the climatic extremes and more urban contexts of North America. While these innovative and alternative passive ventilation systems hold great promise for the future, a rational method to size the components of these systems to achieve the control and precision needed to meet the conflicting constraints of new ventilation and air tightness standards has not been forthcoming. Such a method will be introduced in this paper and an application of this method will be presented.

  18. Particle deposition in ventilation ducts

    SciTech Connect

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.

  19. Phylogenetic comparison of porcine circovirus type 2 (PCV2) and porcine reproductive respiratory syndrome virus (PRRSV) strains detected in domestic pigs until 2008 and in 2012 in Croatia

    PubMed Central

    2014-01-01

    Background Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) have been present for the last 2 decades in Croatia, causing large economical losses in the pig production. The clinical features of the infections are mostly manifested by the development of respiratory problems, weight loss and poor growth performance, as well as reproductive failure in pregnant sows. Even though the infections are continuously recognized in some regions in Croatia, the heterogeneity of the detected viral strains from 2012 has not yet been investigated. The objective of this study was to compare virus strains of PCV2 and PRRSV detected until 2008 in Croatia with strains isolated in 2012 to gain a better epidemiological understanding of these two infections. Results PCV2 and PRRSV strains detected in 2012 in fattening pigs from regions where these two diseases have been previously described were compared to strains that have been detected in the same regions within the past two decades. The phylogenetic analysis revealed that the circulating PCV2 and PRRSV strains are distantly related to the previously described Croatian viral strains. However, when compared to known isolates from the GenBank a high genetic identity of PRRSV isolates with isolates from Hungary, Denmark and the Netherlands was found. Conclusion The results of this study reveal that even though PCV2 and PRRSV are constantly present in the investigated regions in Croatia, the viral strains found in 2012 genetically differ from those detected in earlier years. This indicates that new entries into the pig population appeared with regard to both infections, probably as a result of pig trade. PMID:24839544

  20. Oral vaccination with attenuated Salmonella enterica serovar Typhimurium expressing Cap protein of PCV2 and its immunogenicity in mouse and swine models.

    PubMed

    Xu, Xin-Gang; Zhao, Hong-Ni; Zhang, Qi; Ding, Li; Li, Zhao-Cai; Li, Wei; Wu, Hung-Yi; Chuang, Kuo-Pin; Tong, De-Wen; Liu, Hung-Jen

    2012-06-15

    Attenuated Salmonella enterica serovar Typhimurium (S. typhimurium) was selected as a transgenic vehicle for the development of oral vaccines against Porcine circovirus type 2 (PCV2). The Cap-encoding gene of PCV2 was amplified by PCR and cloned into expression vector pYA3341. The recombinant plasmid pYA3341-Cap was transformed into attenuated S. typhimurium X4550. BALB/c mice were inoculated orally with various doses of attenuated S. typhimurium X4550/pYA3341-Cap. The bacterium was safe to mice at dose of 2×10(9)cfu and eventually eliminated in the spleen and mesenteric lymph nodes at 4 weeks post-immunization. The flow cytometry analysis showed that the percentage of CD4(+) T cells and CD4(+)/CD8(+) ratio were increased significantly in mice immunized with attenuated S. typhimurium X4550/pYA3341-Cap. Vaccine tests in swine showed that the oral immunization with attenuated S. typhimurium X4550/pYA3341-Cap could elicit significantly higher Cap antibody titers in the treated swine than the control groups. Virus neutralization test showed that serum from the swine treated with attenuated S. typhimurium X4550/pYA3341-Cap had significant levels of neutralization activities. The swine lymphocyte proliferative responses indicated that attenuated S. typhimurium X4550/pYA3341-Cap could induce obvious cellular immune response. An in vivo challenge study showed the swine treated with attenuated S. typhimurium X4550/pYA3341-Cap had significantly lower PCV2-associated lesions and PCV2 viremia than the control groups. The results indicated that attenuated S. typhimurium X4550/pYA3341-Cap can be a potential vaccine against PCV2 infections. PMID:22326539

  1. The effects of the semirecumbent position on hemodynamic status in patients on invasive mechanical ventilation: prospective randomized multivariable analysis

    PubMed Central

    2013-01-01

    Introduction Adopting the 45° semirecumbent position in mechanically ventilated critically ill patients is recommended, as it has been shown to reduce the incidence of ventilator-associated pneumonia. Although the benefits to the respiratory system are clear, it is not known whether elevating the head of the bed results in hemodynamic instability. We examined the effect of head of bed elevation (HBE) on hemodynamic status and investigated the factors that influence mean arterial pressure (MAP) and central venous oxygen saturation (ScvO2) when patients were positioned at 0°, 30°, and 45°. Methods Two hundred hemodynamically stable adults on invasive mechanical ventilation admitted to a multidisciplinary surgical intensive care unit were recruited. Patients' characteristics included catecholamine and sedative doses, the original angle of head of bed elevation (HBE), the level of positive end expiratory pressure (PEEP), duration and mode of mechanical ventilation. A sequence of HBE positions (0°, 30°, and 45°) was adopted in random order, and MAP and ScvO2 were measured at each position. Patients acted as their own controls. The influence of degree of HBE and of the covariables on MAP and ScvO2 was analyzed by using liner mixed models. Additionally, uni- and multivariable logistic regression models were used to indentify risk factors for hypotension during HBE, defined as MAP <65 mmHg. Results Changing HBE from supine to 45° caused significant reductions in MAP (from 83.8 mmHg to 71.1 mmHg, P < 0.001) and ScvO2 (76.1% to 74.3%, P < 0.001). Multivariable modeling revealed that mode and duration of mechanical ventilation, the norepinephrine dose, and HBE had statistically significant influences. Pressure-controlled ventilation was the most influential risk factor for hypotension when HBE was 45° (odds ratio (OR) 2.33, 95% confidence interval (CI), 1.23 to 4.76, P = 0.017). Conclusions HBE to the 45° position is associated with significant decreases in MAP and ScvO2 in mechanically ventilated patients. Pressure-controlled ventilation, higher simplified acute physiology (SAPS II) score, sedation, high catecholamine, and PEEP requirements were identified as independent risk factors for hypotension after backrest elevation. Patients at risk may need positioning at 20° to 30° to overcome the negative effects of HBE, especially in the early phase of intensive care unit admission. PMID:23622019

  2. CFD applications in tunnel ventilation analysis

    SciTech Connect

    Ray, R.E. Jr.; Zigh, A.

    1999-07-01

    Longitudinal ventilation systems in transit and rail tunnels are typically analyzed by one dimensional ventilation network simulation models, such as the Subway Environment Simulation (SES) program. However, in recent years computational fluid dynamics (CFD) modeling has been utilized in conjunction with one-dimensional ventilation network programs to study ventilation systems for large volume spaces such as transit stations and rail overbuilds, as well as for vehicular tunnels. CFD uses numerical methods to simulate complex fluid flow phenomena in three dimensions to predict the distribution of velocity, pressure, temperature, concentration, and other relevant variables throughout the volume. This paper presents an overview of CFD study results from emergency ventilation analysis for a transit station and both emergency ventilation and diesel emissions analysis for a rail overbuild.

  3. Efficacy of stepwise sodium profile versus individualized dialysate sodium in blood pressure control among hemodialysis patients

    PubMed Central

    Shahgholian, Nahid; Hashemi, Maryam Sadat; Shahidi, Shahrzade

    2015-01-01

    Background: Hypertension is very common in patients with end-stage renal disease and accelerates cardiovascular morbidity and mortality. The most important factor in achieving normal blood pressure in these patients is reaching dry weight. Sodium and extracellular fluid balance play a vital role in this regard. Considering the lack of consensus about the efficacy of stepwise sodium profile and individualized dialysate sodium, this study aimed to determine the superior method for blood pressure control in hemodialysis patients. Materials and Methods: In a quasi-experimental study, patients satisfying the inclusion criteria were enrolled through convenience sampling. The patients were randomly assigned to two groups of stepwise sodium profile and individualized dialysate sodium. Information record form was used for data collection. Data were analyzed with paired and independent t-test and descriptive statistics using SPSS for Windows 20.0. Results: Patients in the two groups were similar in qualitative and quantitative background variables. While systolic blood pressure significantly decreased following hemodialysis with individualized dialysate sodium (P < 0.001), there was no significant difference between pre- and post-dialysis systolic blood pressure values using stepwise sodium profile (P = 0.060). Individualized dialysate sodium caused greater change in the mean systolic blood pressure than stepwise sodium profile did (P = 0.040). Pre- and post-dialysis diastolic blood pressure values showed significant differences in both groups (P < 0.001 using individualized dialysate sodium and P = 0.009 using stepwise sodium profile). However, the mean changes in diastolic blood pressure of the two groups were not significantly different (P = 0.295). Conclusions: We found no significant difference in interdialytic weight gain and blood pressure control by the two methods. The change in systolic blood pressure was lower in the stepwise profile method than in the individualized dialysate sodium method, and this method did not cause interdialytic hypertension. So, by adjusting the dialysis solution with regard to plasma sodium levels, lead to more blood pressure control. Meanwhile, the two groups were not significantly different in the mean changes of diastolic blood pressure. PMID:25709685

  4. A current and historical perspective on disparities in US childhood pneumococcal conjugate vaccine adherence and in rates of invasive pneumococcal disease: Considerations for the routinely-recommended, pediatric PCV dosing schedule in the United States.

    PubMed

    McLaughlin, John M; Utt, Eric A; Hill, Nina M; Welch, Verna L; Power, Edward; Sylvester, Gregg C

    2016-01-01

    Previous research has suggested that reducing the US 4-dose PCV13 schedule to a 3-dose schedule may provide cost savings, despite more childhood pneumococcal disease. The study also stressed that dose reduction should be coupled with improved PCV adherence, however, US PCV uptake has leveled-off since 2008. An estimated 24-36% of US children aged 5-19 months are already receiving a reduced PCV schedule (i.e., missing ≥1 dose). This raises a practical concern that, under a reduced, 3-dose schedule, a similar proportion of children may receive ≤2 doses. It is also unknown if a reduced, 3-dose PCV schedule in the United States will afford the same disease protection as 3-dose schedules used elsewhere, given lower US PCV adherence. Finally, more assurance is needed that, under a reduced schedule, racial, socioeconomic, and geographic disparities in PCV adherence will not correspond with disproportionately higher rates of pneumococcal disease among poor or minority children. PMID:26376039

  5. Echocardiography in a Patient on Mechanical Ventilation.

    PubMed

    Sachdeva, Ankush

    2015-07-01

    Cardiopulmonary interactions or effects of spontaneous and mechanical ventilation (MV) were first documented in the year 1733. Stephen Hales showed that the blood pressure of healthy individual fell during spontaneous inspiration and he later went on to discover the ventilator. A year later Kussmaul described pulsus paradoxus (inspiratory absence of radial pulse) in patients with tubercular pericarditis. Echocardiography can help to diagnose a wide variety of cardiovascular diseases and can guide therapeutic decisions in patients on mechanical ventilation. PMID:26731826

  6. 30 CFR 57.8532 - Opening and closing ventilation doors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Opening and closing ventilation doors. 57.8532... Ventilation Underground Only § 57.8532 Opening and closing ventilation doors. When ventilation control doors...-establish normal ventilation to working places....

  7. Neurally adjusted ventilatory assist: a ventilation tool or a ventilation toy?

    PubMed

    Verbrugghe, Walter; Jorens, Philippe G

    2011-03-01

    Mechanical ventilation has, since its introduction into clinical practice, undergone a major evolution from controlled ventilation to various modes of assisted ventilation. Neurally adjusted ventilatory assist (NAVA) is the newest development. The implementation of NAVA requires the introduction of a catheter to measure the electrical activity of the diaphragm (EA(di)). NAVA relies, opposite to conventional assisted ventilation modes, on the EA(di) to trigger the ventilator breath and to adjust the ventilatory assist to the neural drive. The amplitude of the ventilator assist is determined by the instantaneous EA(di) and the NAVA level set by the clinician. The NAVA level amplifies the EA(di) signal and determines instantaneous ventilator assist on a breath-to-breath basis. Experimental and clinical data suggest superior patient-ventilator synchrony with NAVA. Patient-ventilator asynchrony is present in 25% of mechanically ventilated patients in the intensive care unit and may contribute to patient discomfort, sleep fragmentation, higher use of sedation, development of delirium, ventilator-induced lung injury, prolonged mechanical ventilation, and ultimately mortality. With NAVA, the reliance on the EA(di) signal, together with an intact ventilatory drive and intact breathing reflexes, allows integration of the ventilator in the neuro-ventilatory coupling on a higher level than conventional ventilation modes. The simple monitoring of the EA(di) signal alone may provide the clinician with important information to guide ventilator management, especially during the weaning process. Although, until now, little evidence proves the superiority of NAVA on clinically relevant end points, it seems evident that patient populations (eg, COPD and small children) with major patient-ventilator asynchrony may benefit from this new ventilatory tool. PMID:21255496

  8. Jet mixing in low gravity - Results of the Tank Pressure Control Experiment

    NASA Technical Reports Server (NTRS)

    Bentz, M. D.; Meserole, J. S.; Knoll, R. H.

    1992-01-01

    The Tank Pressure Control Experiment (TPCE) is discussed with attention given to the results for controlling storage-tank pressures by forced-convective mixing in microgravitational environments. The fluid dynamics of cryogenic fluids in space is simulated with freon-113 during axial-jet-induced mixing. The experimental flow-pattern data are found to confirm previous data as well as existing mixing correlations. Thermal nonuniformities and tank pressure can be reduced by employing low-energy mixing jets which are useful for enhancing heat/mass transfer between phases. It is found that space cryogenic systems based on the principle of active mixing can be more reliable and predictable than other methods, and continuous or periodic mixing can be accomplished with only minor energy addition to the fluid.

  9. A Thermocouple Homogeneity Scanner Based on an Open Pressure-Controlled Water Heatpipe

    NASA Astrophysics Data System (ADS)

    White, D. R.; Mason, R. S.

    2010-09-01

    This paper demonstrates a low-cost, high-performance thermocouple homogeneity scanner based on a pressure-controlled water heatpipe that is open to the atmosphere. With this arrangement, very much like a steam-point apparatus, the atmosphere provides the controlled pressure and the buffer gas for the heatpipe, and the isothermal zone is close to 100 °C. The thermocouple is inserted into the steam within the heatpipe through a plastic membrane so that the gradient is imposed over a spatial region determined primarily by heat flow within the thermocouple body, and can be as small as a few millimeters. The paper explains the construction of the scanner, and presents results of example scans demonstrating the uniformity and resolution of the scanner.

  10. Independent Orbiter Assessment (IOA): Assessment of the atmospheric revitalization pressure control subsystem FMEA/CIL

    NASA Technical Reports Server (NTRS)

    Saiidi, M. J.

    1988-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the atmospheric Revitalization Pressure Control Subsystem (ARPCS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL proposed Post 51-L updates based upon the CCB/PRCB presentations and an informal criticality summary listing. A discussion of each discrepancy from the comparison is provided through additional analysis as required. These discrepancies were flagged as issues, and recommendations were made based on the FMEA data available at the time. This report documents the results of that comparison for the Orbiter ARPCS hardware.

  11. Development of an expert system for analysis of Shuttle atmospheric revitalization and pressure control subsystem anomalies

    NASA Technical Reports Server (NTRS)

    Lafuse, Sharon A.

    1991-01-01

    The paper describes the Shuttle Leak Management Expert System (SLMES), a preprototype expert system developed to enable the ECLSS subsystem manager to analyze subsystem anomalies and to formulate flight procedures based on flight data. The SLMES combines the rule-based expert system technology with the traditional FORTRAN-based software into an integrated system. SLMES analyzes the data using rules, and, when it detects a problem that requires simulation, it sets up the input for the FORTRAN-based simulation program ARPCS2AT2, which predicts the cabin total pressure and composition as a function of time. The program simulates the pressure control system, the crew oxygen masks, the airlock repress/depress valves, and the leakage. When the simulation has completed, other SLMES rules are triggered to examine the results of simulation contrary to flight data and to suggest methods for correcting the problem. Results are then presented in form of graphs and tables.

  12. A comparison of fuzzy logic-PID control strategies for PWR pressurizer control

    SciTech Connect

    Kavaklioglu, K.; Ikonomopoulos, A. )

    1993-01-01

    This paper describes the results obtained from a comparison performed between classical proportional-integral-derivative (PID) and fuzzy logic (FL) controlling the pressure in a pressurized water reactor (PWR). The two methodologies have been tested under various transient scenarios, and their performances are evaluated with respect to robustness and on-time response to external stimuli. One of the main concerns in the safe operation of PWR is the pressure control in the primary side of the system. In order to maintain the pressure in a PWR at the desired level, the pressurizer component equipped with sprayers, heaters, and safety relief valves is used. The control strategy in a Westinghouse PWR is implemented with a PID controller that initiates either the electric heaters or the sprayers, depending on the direction of the coolant pressure deviation from the setpoint.

  13. The role of Ca(2+) activated Cl(-) channels in blood pressure control.

    PubMed

    Matchkov, Vladimir V; Boedtkjer, Donna M; Aalkjaer, Christian

    2015-04-01

    Ca(2+)-activated Cl(-) channels (CaCCs) have numerous functions in the body and are potential players in the control of blood pressure. The CaCCs represent a heterologous group including at least two protein families; TMEM16 and bestrophins. CaCCs expression has been shown in the kidney, the heart and blood vessels. Agonist-stimulated Ca(2+)-activated Cl(-) current is important for secretion in kidney epithelia, generation of a repolarizing current in the heart and amplification of excitation-contraction coupling in vascular smooth muscle cells. Changes in CaCC expression are shown in association with hypertension, kidney cysts, sudden cardiac death and arrhythmias. This review discusses recent advances in studies concerning the role of CaCC for blood pressure control with focus on the kidney, the heart and blood vessels. PMID:25727479

  14. Sex differences in blood pressure control during 6° head-down tilt bed rest.

    PubMed

    Arzeno, Natalia M; Stenger, Michael B; Lee, Stuart M C; Ploutz-Snyder, Robert; Platts, Steven H

    2013-04-15

    Spaceflight-induced orthostatic intolerance has been studied for decades. Although ∼22% of the astronaut corps are women, most mechanistic studies use mostly male subjects, despite known sex differences in autonomic control and postflight orthostatic intolerance. We studied adrenergic, baroreflex, and autonomic indexes during continuous infusions of vasoactive drugs in men and women during a 60-day head-down bed rest. Volunteers were tested before bed rest (20 men and 10 women) and around day 30 (20 men and 10 women) and day 60 (16 men and 8 women) of bed rest. Three increasing doses of phenylephrine (PE) and sodium nitroprusside were infused for 10 min after an infusion of normal saline. A 20-min rest period separated the phenylephrine and sodium nitroprusside infusions. Autonomic activity was approximated by spectral indexes of heart rate and blood pressure variability, and baroreflex sensitivity was measured by the spontaneous baroreflex slope. Parasympathetic modulation and baroreflex sensitivity decreased with bed rest, with women experiencing a larger decrease in baroreflex sensitivity by day 30 than men. The sympathetic activation of men and parasympathetic responsiveness of women in blood pressure control during physiological stress were preserved throughout bed rest. During PE infusions, women experienced saturation of the R-R interval at high frequency, whereas men did not, revealing a sex difference in the parabolic relationship between high-frequency R-R interval, a measurement of respiratory sinus arrhythmia, and R-R interval. These sex differences in blood pressure control during simulated microgravity reveal the need to study sex differences in long-duration spaceflight to ensure the health and safety of the entire astronaut corps. PMID:23396455

  15. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 4 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 4 of 4.

  16. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 3 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 3 of 4.

  17. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 2 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 2 of 4.

  18. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 1 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 1 of 4.

  19. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-1 Power ventilation systems except...

  20. Measurement of fractional order model parameters of respiratory mechanical impedance in total liquid ventilation.

    PubMed

    Beaulieu, Alexandre; Boss, Dominick; Micheau, Philippe; Avoine, Olivier; Praud, Jean-Paul; Walti, Herv

    2012-02-01

    This study presents a methodology for applying the forced-oscillation technique in total liquid ventilation. It mainly consists of applying sinusoidal volumetric excitation to the respiratory system, and determining the transfer function between the delivered flow rate and resulting airway pressure. The investigated frequency range was f ? [0.05, 4] Hz at a constant flow amplitude of 7.5 mL/s. The five parameters of a fractional order lung model, the existing "5-parameter constant-phase model," were identified based on measured impedance spectra. The identification method was validated in silico on computer-generated datasets and the overall process was validated in vitro on a simplified single-compartment mechanical lung model. In vivo data on ten newborn lambs suggested the appropriateness of a fractional-order compliance term to the mechanical impedance to describe the low-frequency behavior of the lung, but did not demonstrate the relevance of a fractional-order inertance term. Typical respiratory system frequency response is presented together with statistical data of the measured in vivo impedance model parameters. This information will be useful for both the design of a robust pressure controller for total liquid ventilators and the monitoring of the patient's respiratory parameters during total liquid ventilation treatment. PMID:21947517

  1. An adaptive controller for the administration of closed-circuit anesthesia during spontaneous and assisted ventilation.

    PubMed

    Sharma, A; Griffith, R L; Roy, R J

    1993-01-01

    Although reduced waste of expensive anesthetic gases is a strong incentive to use closed-circuit anesthesia, manual methods of performing closed-circuit anesthesia are labor intensive and thus not widely used. Automation of closed-circuit anesthesia delivery may reduce the work. A pressure-based adaptive controller was designed and tested on mongrel dogs to evaluate the feasibility of automating closed-circuit anesthesia using an accessory to an existing clinical anesthesia machine and a gas analyzer. The controller was found stable and responsive with good control of oxygen concentration and acceptable control of halothane end-tidal concentration. The response time for oxygen was 5.23 +/- 1.26 minutes, and that for halothane was 2.67 +/- 1.83 minutes. The average peak overshoot for halothane at the start of the experiment was 26.9%. This pressure controller differs from previously published closed-circuit anesthesia controllers that measure gas volume changes within a mechanical ventilator. A pressure-based controller is easily attached to a standard anesthesia machine and is compatible with modes of ventilation other than controlled mechanical ventilation. The controller used in this study is not designed for clinical use, but was developed to investigate the feasibility of pressure as a basis for gas volume control in closed-circuit anesthesia administration. PMID:8463802

  2. Improved OCT imaging of lung tissue using a prototype for total liquid ventilation

    NASA Astrophysics Data System (ADS)

    Schnabel, Christian; Meissner, Sven; Koch, Edmund

    2011-06-01

    Optical coherence tomography (OCT) is used for imaging subpleural alveoli in animal models to gain information about dynamic and morphological changes of lung tissue during mechanical ventilation. The quality of OCT images can be increased if the refraction index inside the alveoli is matched to the one of tissue via liquid-filling. Thereby, scattering loss can be decreased and higher penetration depth and tissue contrast can be achieved. Until now, images of liquid-filled lungs were acquired in isolated and fixated lungs only, so that an in vivo measurement situation is not present. To use the advantages of liquid-filling for in vivo imaging of small rodent lungs, it was necessary to develop a liquid ventilator. Perfluorodecalin, a perfluorocarbon, was selected as breathing fluid because of its refraction index being similar to the one of water and the high transport capacity for carbon dioxide and oxygen. The setup is characterized by two independent syringe pumps to insert and withdraw the fluid into and from the lung and a custom-made control program for volume- or pressure-controlled ventilation modes. The presented results demonstrate the liquid-filling verified by optical coherence tomography and intravital microscopy (IVM) and the advantages of liquid-filling to OCT imaging of subpleural alveoli.

  3. Dynamic Behaviour of Ventilated Hydrofoils.

    NASA Astrophysics Data System (ADS)

    Kjeldsen, Morten; Arndt, Roger; Wosnik, Martin

    2006-11-01

    In certain types of pumping applications oscillations are induced by operation with liquids containing a free gas load. In order to understand the physics of this process, a series of tests with a ventilated A 2D NACA 0015 hydrofoil were performed in the water tunnel at the St. Anthony Falls Laboratory of the University of Minnesota. The special bubble removal feature of the water tunnel allowed continuous ventilation without experiencing visible bubbles upstream the hydrofoil. These studies build on previous work on cavitation-induced oscillations. Gas injection studies were made over a range of gas flow rates and test section pressure. The results clearly show that lift oscillations increase in intensity when the gas load is increased. The point of maximum unsteadiness is also associated the rapid decline of the foil performance as measured as average lift. Further increase of the gas injection load gives a steady behaviour with almost no lift. These experiments are compared with traditional cavitation experiments. The similarities between gas injection- and cavitation induced unsteadiness on the hydrofoil are many, but the amplitude of lift oscillations found on the foil with gas injection corresponds to about 50% of that found for cavitating hydrofoils. The fact that the oscillations are periodic leads to the consideration of both passive and active control.

  4. Effect of Residual Noncondensables on Pressurization and Pressure Control of a Zero-Boil-Off Tank in Microgravity

    NASA Technical Reports Server (NTRS)

    Kassemi, Mohammad; Hylton, Sonya; Kartizova, Olga

    2013-01-01

    The Zero-Boil-Off Tank (ZBOT) Experiment is a small-scale experiment that uses a transparent ventless Dewar and a transparent simulant phase-change fluid to study sealed tank pressurization and pressure control with applications to on-surface and in-orbit storage of propellant cryogens. The experiment will be carried out under microgravity conditions aboard the International Space Station in the 2014 timeframe. This paper presents preliminary results from ZBOT's ground-based research that focuses on the effects of residual noncondensable gases in the ullage on both pressurization and pressure reduction trends in the sealed Dewar. Tank pressurization is accomplished through heating of the test cell wall in the wetted and un-wetted regions simultaneously or separately. Pressure control is established through mixing and destratification of the bulk liquid using a temperature controlled forced jet flow with different degrees of liquid jet subcooling. A Two-Dimensional axisymmetric two-phase CFD model for tank pressurization and pressure control is also presented. Numerical prediction of the model are compared to experimental 1g results to both validate the model and also indicate the effect of the noncondensable gas on evolution of pressure and temperature distributions in the ullage during pressurization and pressure control. Microgravity simulations case studies are also performed using the validated model to underscore and delineate the profound effect of the noncondensables on condensation rates and interfacial temperature distributions with serious implications for tank pressure control in reduced gravity.

  5. History of Mechanical Ventilation. From Vesalius to Ventilator-induced Lung Injury.

    PubMed

    Slutsky, Arthur S

    2015-05-15

    Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced back about five centuries to the seminal work of Andreas Vesalius. This article is a short history of mechanical ventilation, tracing its origins over the centuries to the present day. One of the great advances in ventilatory support over the past few decades has been the development of lung-protective ventilatory strategies, based on our understanding of the iatrogenic consequences of mechanical ventilation such as ventilator-induced lung injury. These strategies have markedly improved clinical outcomes in patients with respiratory failure. PMID:25844759

  6. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  7. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  8. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ventilation plan or revisions thereto shall be submitted to the District Manager for review and comments upon... greater than five hundred feet to the inch, showing: (1) Direction and quantity of principal air flows; (2.... (5) Locations of air regulators and stoppings and ventilation doors not shown in paragraph (d)...

  9. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ventilation plan or revisions thereto shall be submitted to the District Manager for review and comments upon... greater than five hundred feet to the inch, showing: (1) Direction and quantity of principal air flows; (2.... (5) Locations of air regulators and stoppings and ventilation doors not shown in paragraph (d)...

  10. Commissioning Ventilated Containment Systems in the Laboratory

    SciTech Connect

    Not Available

    2008-08-01

    This Best Practices Guide focuses on the specialized approaches required for ventilated containment systems, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. Geared toward architects, engineers, and facility managers, this guide provides information about technologies and practices to use in designing, constructing, and operating operating safe, sustainable, high-performance laboratories.

  11. New modes of assisted mechanical ventilation.

    PubMed

    Suarez-Sipmann, F

    2014-05-01

    Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes. PMID:24507472

  12. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  13. Preoperational test report, primary ventilation system

    SciTech Connect

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  14. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and shall serve no other space. Weather cowls shall be provided with a double layer of wire screen of... temperature below 100 °F. with 88 °F. weather air. Mechanical cooling may be used where ventilation... 130 °F. with an assumed outside temperature of 115 °F. (2) Ventilation supply weather openings...

  15. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... and shall serve no other space. Weather cowls shall be provided with a double layer of wire screen of... temperature below 100 °F. with 88 °F. weather air. Mechanical cooling may be used where ventilation... 130 °F. with an assumed outside temperature of 115 °F. (2) Ventilation supply weather openings...

  16. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... and shall serve no other space. Weather cowls shall be provided with a double layer of wire screen of... temperature below 100 °F. with 88 °F. weather air. Mechanical cooling may be used where ventilation... 130 °F. with an assumed outside temperature of 115 °F. (2) Ventilation supply weather openings...

  17. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... and shall serve no other space. Weather cowls shall be provided with a double layer of wire screen of... temperature below 100 °F. with 88 °F. weather air. Mechanical cooling may be used where ventilation... 130 °F. with an assumed outside temperature of 115 °F. (2) Ventilation supply weather openings...

  18. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... and shall serve no other space. Weather cowls shall be provided with a double layer of wire screen of... temperature below 100 °F. with 88 °F. weather air. Mechanical cooling may be used where ventilation... 130 °F. with an assumed outside temperature of 115 °F. (2) Ventilation supply weather openings...

  19. Infiltration in ASHRAE's Residential Ventilation Standards

    SciTech Connect

    Sherman, Max

    2008-10-01

    The purpose of ventilation is to dilute or remove indoor contaminants that an occupant could be exposed to. It can be provided by mechanical or natural means. ASHRAE Standards including standards 62, 119, and 136 have all considered the contribution of infiltration in various ways, using methods and data from 20 years ago. The vast majority of homes in the United States and indeed the world are ventilated through natural means such as infiltration caused by air leakage. Newer homes in the western world are tight and require mechanical ventilation. As we seek to provide acceptable indoor air quality at minimum energy cost, it is important to neither over-ventilate norunder-ventilate. Thus, it becomes critically important to correctly evaluate the contribution infiltration makes to both energy consumption and equivalent ventilation. ASHRAE Standard 62.2 specifies how much mechanical ventilation is considered necessary to provide acceptable indoor air quality, but that standard is weak on how infiltration can contribute towards meeting the total requirement. In the past ASHRAE Standard 136 was used to do this, but new theoretical approaches and expanded weather data have made that standard out of date. This article will describe how to properly treat infiltration as an equivalent ventilation approach and then use new data and these new approaches to demonstrate how these calculations might be done both in general and to update Standard 136.

  20. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ventilation plan or revisions thereto shall be submitted to the District Manager for review and comments upon... and booster fans including manufacturer's name, type, size, fan speed, blade setting, approximate... sketches showing how ventilation is accomplished in each typical type of working place including...

  1. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ventilation plan or revisions thereto shall be submitted to the District Manager for review and comments upon... and booster fans including manufacturer's name, type, size, fan speed, blade setting, approximate... sketches showing how ventilation is accomplished in each typical type of working place including...

  2. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ventilation plan or revisions thereto shall be submitted to the District Manager for review and comments upon... and booster fans including manufacturer's name, type, size, fan speed, blade setting, approximate... sketches showing how ventilation is accomplished in each typical type of working place including...

  3. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... ventilated. Carbon monoxide concentration may not exceed one part in 20,000 parts of air. (b) For...

  4. 14 CFR 29.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ventilation. 29.831 Section 29.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 29.831 Ventilation. (a) Each passenger and...

  5. 14 CFR 121.219 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Ventilation. 121.219 Section 121.219 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS... passenger or crew compartment must be suitably ventilated. Carbon monoxide concentration may not be...

  6. 14 CFR 121.219 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Ventilation. 121.219 Section 121.219 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS... passenger or crew compartment must be suitably ventilated. Carbon monoxide concentration may not be...

  7. 14 CFR 29.831 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ventilation. 29.831 Section 29.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 29.831 Ventilation. (a) Each passenger and...

  8. 14 CFR 121.219 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Ventilation. 121.219 Section 121.219 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS... passenger or crew compartment must be suitably ventilated. Carbon monoxide concentration may not be...

  9. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... ventilated. Carbon monoxide concentration may not exceed one part in 20,000 parts of air. (b) For...

  10. 14 CFR 121.219 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Ventilation. 121.219 Section 121.219 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS... passenger or crew compartment must be suitably ventilated. Carbon monoxide concentration may not be...

  11. 14 CFR 121.219 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ventilation. 121.219 Section 121.219 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS... passenger or crew compartment must be suitably ventilated. Carbon monoxide concentration may not be...

  12. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... ventilated. Carbon monoxide concentration may not exceed one part in 20,000 parts of air. (b) For...

  13. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194.15-5 Ventilation. (a) Operations, reactions...

  14. Healthcare Technology Management (HTM) of mechanical ventilators by clinical engineers.

    PubMed

    Yoshioka, Jun; Nakane, Masaki; Kawamae, Kaneyuki

    2014-01-01

    Mechanical ventilator failures expose patients to unacceptable risks, and maintaining mechanical ventilator safety is an important issue. We examined the usefulness of maintaining mechanical ventilators by clinical engineers (CEs) using a specialized calibrator. These evaluations and the ability to make in-house repairs proved useful for obviating the need to rent ventilators which, in turn, might prove faulty themselves. The CEs' involvement in maintaining mechanical ventilators is desirable, ensures prompt service, and, most importantly, enhances safe management of mechanical ventilators. PMID:25520839

  15. The new generation of mechanical ventilators.

    PubMed

    Kacmarek, R M; Meklaus, G J

    1990-07-01

    The newest generation of mechanical ventilators has allowed increased flexibility and enhanced mechanical performance. Primary advantages of these units are improved interfacing during spontaneous breathing, improved monitoring capabilities, and increased safety by the addition of apnea/back-up ventilation during all spontaneous breathing modes. The major drawbacks of these units are their operational complexity and the inclusion of a large number of highly sensitive alarms. Finally, in spite of the scope and capabilities of these ventilators, the vast majority of patients can be very capably managed with the "mid-range" ventilators discussed as well as the majority of well maintained older generation ventilators. All the bells and whistles available on top-of-the-line units do not necessarily constitute an improvement in patient care. PMID:2198996

  16. An intelligent control system for ventilators.

    PubMed

    Wang, C S; Shaw, D; Jih, K S

    1998-10-01

    This study reports on a ventilator system that consists of several intelligent modules for controlling ventilator operation. These modules are software programs in two controllers. One controller is a personal computer used for diagnoses, determining settings and checking the effects of settings. The other controller is a single-chip microprocessor in a ventilator that controls the ventilator's settings in accordance with the computer settings. After setting up the system, an artificial lung model simulating a patient's lung is used to test the system. The result of test run indicated that it always responds to a patient's lung condition in a stable manner. Thus, the proposed system with its intelligent modules may assist clinicians in caring for patients and managing ventilator operation. PMID:9832029

  17. Mechanical Ventilation in the Respiratory Distress Syndrome

    PubMed Central

    Murdock, A. I.; Linsao, L.; Reid, M. McC.; Sutton, M. D.; Tilak, K. S.; Ulan, O. A.; Swyer, P. R.

    1970-01-01

    A controlled study of mechanical ventilation has been performed in infants with respiratory distress syndrome. 168 infants in respiratory failure were ventilated and 53 similar infants were not. Artificial mechanical ventilation improved survival in infants weighing more than 2000 g. from 15% to 43% (4/27 vs. 29/67, p < 0·025). Infants who weighed more than 1500 g. and developed respiratory failure at less than 38 hours of age had an improved survival (16/31) on ventilatory treatment, as compared with infants more than 1500 g. ventilated at more than 38 hours of age (24/78) (p < 0·05). Artificial ventilation improved Pao2, Paco2, and [H+]a within one hour, but it was only the change in [H+]a in infants more than 2000 g. which was of prognostic significance. Survival rates were similar for each of the three types of respirator used. PMID:4920541

  18. Risk factors for nasopharyngeal carriage of Streptococcus pneumoniae in healthy Turkish children after the addition of heptavalent pneumococcal conjugate vaccine (PCV7) to the national vaccine schedule.

    PubMed

    Özdemir, Halil; Çiftçi, Ergin; Durmaz, Rıza; Güriz, Haluk; Aysev, Ahmet Derya; Karbuz, Adem; Gökdemir, Refik; Acar, Bülent; Nar-Ötgün, Selin; Ertek, Mustafa; Köse, Serdal Kenan; İnce, Erdal

    2013-01-01

    The purpose of this study was to investigate the effects of pneumococcal conjugate vaccine (PCV7) on nasopharyngeal (NP) carriage rates of Streptococcus pneumoniae in healthy Turkish children. The study was conducted on 1101 healthy Turkish children between 1 month and 18 years of age. The median and mean ages of the children were 25 months (1 month-18 years) and 45.7±49.6 months, respectively. S. pneumoniae was isolated in 241/1101 (21.9%) children included in the study. According to multivariate analysis, being <5 years of age, presence of a child attending a daycare center, recovery from respiratory infection within the last month, low income level of the family, and presence of more children in the family were found to be the risk factors for the NP pneumococcal carriage. The carriage rate of NP pneumococci in healthy children was not influenced by PCV7 in Turkey. PMID:24577974

  19. Constant pressure-controlled extrusion method for the preparation of Nano-sized lipid vesicles.

    PubMed

    Morton, Leslie A; Saludes, Jonel P; Yin, Hang

    2012-01-01

    Liposomes are artificially prepared vesicles consisting of natural and synthetic phospholipids that are widely used as a cell membrane mimicking platform to study protein-protein and protein-lipid interactions, monitor drug delivery, and encapsulation. Phospholipids naturally create curved lipid bilayers, distinguishing itself from a micelle. Liposomes are traditionally classified by size and number of bilayers, i.e. large unilamellar vesicles (LUVs), small unilamellar vesicles (SUVs) and multilamellar vesicles (MLVs). In particular, the preparation of homogeneous liposomes of various sizes is important for studying membrane curvature that plays a vital role in cell signaling, endo- and exocytosis, membrane fusion, and protein trafficking. Several groups analyze how proteins are used to modulate processes that involve membrane curvature and thus prepare liposomes of diameters <100 - 400 nm to study their behavior on cell functions. Others focus on liposome-drug encapsulation, studying liposomes as vehicles to carry and deliver a drug of interest. Drug encapsulation can be achieved as reported during liposome formation. Our extrusion step should not affect the encapsulated drug for two reasons, i.e. (1) drug encapsulation should be achieved prior to this step and liposomes should retain their natural biophysical stability, securely carrying the drug in the aqueous core. These research goals further suggest the need for an optimized method to design stable sub-micron lipid vesicles. Nonetheless, the current liposome preparation technologies (sonication, freeze-and-thaw, sedimentation) do not allow preparation of liposomes with highly curved surface (i.e. diameter <100 nm) with high consistency and efficiency, which limits the biophysical studies of an emerging field of membrane curvature sensing. Herein, we present a robust preparation method for a variety of biologically relevant liposomes. Manual extrusion using gas-tight syringes and polycarbonate membranes, is a common practice but heterogeneity is often observed when using pore sizes <100 nm due to due to variability of manual pressure applied. We employed a constant pressure-controlled extrusion apparatus to prepare synthetic liposomes whose diameters range between 30 and 400 nm. Dynamic light scattering (DLS), electron microscopy and nanoparticle tracking analysis (NTA) were used to quantify the liposome sizes as described in our protocol, with commercial polystyrene (PS) beads used as a calibration standard. A near linear correlation was observed between the employed pore sizes and the experimentally determined liposomes, indicating high fidelity of our pressure-controlled liposome preparation method. Further, we have shown that this lipid vesicle preparation method is generally applicable, independent of various liposome sizes. Lastly, we have also demonstrated in a time course study that these prepared liposomes were stable for up to 16 hours. A representative nano-sized liposome preparation protocol is demonstrated below. PMID:22760481

  20. Co-expression of Ubiquitin gene and capsid protein gene enhances the potency of DNA immunization of PCV2 in mice

    PubMed Central

    2011-01-01

    A recombinant plasmid that co-expressed ubiquitin and porcine circovirus type 2 (PCV2) virus capsid protein (Cap), denoted as pc-Ub-Cap, and a plasmid encoding PCV2 virus Cap alone, denoted as pc-Cap, were transfected into 293T cells. Indirect immunofluorescence (IIF) and confocal microscopy were performed to measure the cellular expression of Cap. Three groups of mice were then vaccinated once every three weeks for a total of three doses with pc-Ub-Cap, pc-Cap or the empty vector pCAGGS, followed by challenging all mice intraperitoneally with 0.5 mL 106.5 TCID50/mL PCV2. To characterize the protective immune response against PCV2 infection in mice, assays of antibody titer (including different IgG isotypes), flow cytometric analysis (FCM), lymphocyte proliferation, cytokine production and viremia were evaluated. The results showed that pc-Ub-Cap and pc-Cap were efficiently expressed in 293T cells. However, pc-Ub-Cap-vaccinated animals had a significantly higher level of Cap-specific antibody and induced a stronger Th1 type cellular immune response than did pc-Cap-vaccinated animals, suggesting that ubiquitin conjugation improved both the cellular and humoral immune responses. Additionally, viral replication in blood was lower in the pc-Ub-Cap-vaccinated group than in the pc-Cap and empty vector groups, suggesting that the protective immunity induced by pc-Ub-Cap is superior to that induced by pc-Cap. PMID:21624113

  1. A meta-analysis comparing the effect of PCV2 vaccines on average daily weight gain and mortality rate in pigs from weaning to slaughter.

    PubMed

    Kristensen, Charlotte Sonne; Baadsgaard, Niels Peter; Toft, Nils

    2011-03-01

    The aim of this investigation was, through a meta-analysis, to review the published literature concerning the effect of PCV2 vaccination on the average daily weight gain (ADG) and on the mortality rate in pigs from weaning to slaughter. The review was restricted to studies investigating the effect of vaccines against PCV2 published from 2006 to 2008, identified using computerised literature databases. Only studies that met the following criteria were included: commercial vaccines were used, pigs or pens were assigned randomly to vaccination versus control groups in herds naturally infected with PCV2, and vaccinated and non-vaccinated pigs were housed together. Furthermore, it was a requirement that sample size, age at vaccination, and production period were stated. The levels of ADG and mortality rate had to be comparable to those seen in modern intensive swine production. In total, 107 studies were identified; 70 were excluded because they did not fulfil the inclusion criteria and 13 were identical to results published elsewhere. A significant effect of PCV2 vaccination on ADG was found for pigs in all production phases. The largest increase in ADG was found for finishing pigs (41.5g) and nursery-finishing pigs (33.6g) with only 10.6g increase in the nursery pigs. Mortality rate was significantly reduced for finishing pigs (4.4%) and nursery-finishing pigs (5.4%), but not for nursery pigs (0.25%). Herds negative for PRRS had a significantly larger increase in ADG compared to herds positive for PRRS. The PRRS status had no effect on mortality rate. PMID:21239076

  2. Effectiveness of the 10-Valent Pneumococcal Conjugate Vaccine (PCV-10) in Children in Chile: A Nested Case-Control Study Using Nationwide Pneumonia Morbidity and Mortality Surveillance Data

    PubMed Central

    Toscano, Cristiana M.; Alencar, Gizelton P.; Alvarez, Andrés; Valenzuela, Maria T.; Andrus, Jon; del Aguila, Roberto; Hormazábal, Juan C.; Araya, Pamela; Pidal, Paola; Matus, Cuauhtemoc R.; de Oliveira, Lucia H.

    2016-01-01

    Background The ten-valent pneumococcal conjugate vaccine (PCV10) was introduced into the Chilean National Immunization Program (NIP) in January 2011 with a 3+1 schedule (2, 4, 6 and 12 months) without catch-up vaccination. We evaluated the effectiveness of PCV10 on pneumonia morbidity and mortality among infants during the first two years after vaccine introduction. Methods This is a population-based nested case-control study using four merged nationwide case-based electronic health data registries: live birth, vaccination, hospitalization and mortality. Children born in 2010 and 2011 were followed from two moths of age for a period of two years. Using four different case definitions of pneumonia hospitalization and/or mortality (all-cause and pneumonia related deaths), all cases and four randomly selected matched controls per case were selected. Controls were matched to cases on analysis time. Vaccination status was then assessed. Vaccine effectiveness (VE) was estimated using conditional logistic regression. Results There were a total of 497,996 children in the 2010 and 2011 Chilean live-birth cohorts. PCV10 VE was 11.2% (95%CI 8.5–13.6) when all pneumonia hospitalizations and deaths were used to define cases. VE increased to 20.7 (95%CI 17.3–23.8) when ICD10 codes used to denote viral pneumonia were excluded from the case definition. VE estimates on pneumonia deaths and all-cause deaths were 71.5 (95%CI 9.0–91.8) and 34.8 (95% CI 23.7–44.4), respectively. Conclusion PCV10 vaccination substantially reduced the number of hospitalizations due to pneumonia and deaths due to pneumonia and to all-causes over this study period. Our findings also reinforce the importance of having quality health information systems for measuring VE. PMID:27058873

  3. Decrease in Hospitalizations for Pneumonia in Children under Five Years of Age in an Indian Reservation in Panama after the Introduction of the Heptavalent Pneumococcal Conjugate Vaccine (PCV7)

    PubMed Central

    Nieto Guevara, Javier; Daza, Carlos

    2013-01-01

    This study quantifies the impact of Heptavalent-Pneumococcal Conjugate Vaccine (PCV7) in Panama on indigenous children younger than 5 years old, based on clinical pneumonia cases. This study demonstrates a significant 41.2% reduction in hospitalizations and 38.6% reduction in referrals for pneumonia following the introduction of PCV7. Burden of disease from pneumonia appears reduced in the ≤12-month- and 13-to-24-month-old groups. PMID:23762081

  4. Emerging, Non-PCV13 Serotypes 11A and 35B of Streptococcus pneumoniae Show High Potential for Biofilm Formation In Vitro

    PubMed Central

    Ardanuy, Carmen; Liñares, Josefina; Fenoll, Asunción; García, Ernesto

    2015-01-01

    Background Since the use of pneumococcal conjugate vaccines PCV7 and PCV13 in children became widespread, invasive pneumococcal disease (IPD) has dramatically decreased. Nevertheless, there has been a rise in incidence of Streptococcus pneumoniae non-vaccine serotypes (NVT) colonising the human nasopharynx. Nasopharyngeal colonisation, an essential step in the development of S. pneumoniae-induced IPD, is associated with biofilm formation. Although the capsule is the main pneumococcal virulence factor, the formation of pneumococcal biofilms might, in fact, be limited by the presence of capsular polysaccharide (CPS). Methodology/Principal Findings We used clinical isolates of 16 emerging, non-PCV13 serotypes as well as isogenic transformants of the same serotypes. The biofilm formation capacity of isogenic transformants expressing CPSs from NVT was evaluated in vitro to ascertain whether this trait can be used to predict the emergence of NVT. Fourteen out of 16 NVT analysed were not good biofilm formers, presumably because of the presence of CPS. In contrast, serotypes 11A and 35B formed ≥45% of the biofilm produced by the non-encapsulated M11 strain. Conclusions/Significance This study suggest that emerging, NVT serotypes 11A and 35B deserve a close surveillance. PMID:25927917

  5. [The applied value of BiPAP mechanical ventilation via facial of nasal mask before or after ordinary mechanical ventilation].

    PubMed

    Chen, P

    1998-01-01

    To expore the applied value of BiPAP ventilator before or after regular ventilation, 44 patients who had indicators of regular mechanical ventilation and 4 patients who had difficulty of getting free from endotracheal intubation mechanical ventilation were ventilated with BiPAP ventilator via facial or nasal mask. The results showed that 13/44 patients had good responses and avoided receiving regular mechanical ventilation with endotracheal intubation or incision. BiPAP ventilation was also effective in patients who were dependent on regular mechanical ventilatin. PMID:10682574

  6. Closed circuit MR compatible pulsatile pump system using a ventricular assist device and pressure control unit.

    PubMed

    Lorenz, R; Benk, C; Bock, J; Stalder, A F; Korvink, J G; Hennig, J; Markl, M

    2012-01-01

    The aim of this study was to evaluate the performance of a closed circuit MR compatible pneumatically driven pump system using a ventricular assist device as pulsatile flow pump for in vitro 3D flow simulation. Additionally, a pressure control unit was integrated into the flow circuit. The performance of the pump system and its test-retest reliability was evaluated using a stenosis phantom (60% lumen narrowing). Bland-Altman analysis revealed a good test-retest reliability (mean differences = -0.016 m/s, limits of agreement = 0.047 m/s) for in vitro flow measurements. Furthermore, a rapid prototyping in vitro model of a normal thoracic aorta was integrated into the flow circuit for a direct comparison of flow characteristics with in vivo data in the same subject. The pneumatically driven ventricular assist device was attached to the ascending aorta of the in vitro model to simulate the beating left ventricle. In the descending part of the healthy aorta a flexible stenosis was integrated to model an aortic coarctation. In vivo and in vitro comparison showed significant (P = 0.002) correlations (r = 0.9) of mean velocities. The simulation of increasing coarctation grade led to expected changes in the flow patterns such as jet flow in the post-stenotic region and increased velocities. PMID:21630351

  7. Independent Orbiter Assessment (IOA): Analysis of the atmospheric revitalization pressure control subsystem

    NASA Technical Reports Server (NTRS)

    Saiidi, M. J.; Duffy, R. E.; Mclaughlin, T. D.

    1986-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results corresponding to the Orbiter Atmospheric Revitalization and Pressure Control Subsystem (ARPCS) are documented. The ARPCS hardware was categorized into the following subdivisions: (1) Atmospheric Make-up and Control (including the Auxiliary Oxygen Assembly, Oxygen Assembly, and Nitrogen Assembly); and (2) Atmospheric Vent and Control (including the Positive Relief Vent Assembly, Negative Relief Vent Assembly, and Cabin Vent Assembly). The IOA analysis process utilized available ARPCS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

  8. Multi-bottle, no compressor, mean pressure control system for a Stirling engine

    DOEpatents

    Corey, John A.

    1990-01-01

    The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

  9. Ventless pressure control of two-phase propellant tanks in microgravity.

    PubMed

    Kassemi, Mohammad; Panzarella, Charles H

    2004-11-01

    This work studies pressurization and pressure control of a large liquid hydrogen storage tank. A finite element model is developed that couples a lumped thermodynamic formulation for the vapor region with a complete solution of the Navier-Stokes and energy equations for the flow and temperature fields in the liquid. Numerical results show that buoyancy effects are strong, even in microgravity, and can reposition a vapor bubble that is initially at the center of the tank to a region near the tank wall in a relatively short time. Long-term tank pressurization with the vapor bubble at the tank wall shows that after an initial transient lasting about a week, the final rate of pressure increase agrees with a purely thermodynamic analysis of the entire tank. However, the final pressure levels are quite different from thermodynamic predictions. Numerical results also show that there is significant thermal stratification in the liquid due to the effects of natural convection. A subcooled jet is used to provide simultaneous cooling and mixing in order to bring the tank pressure back down to its initial value. Three different jet speeds are examined. Although the lowest jet speed is ineffective at controlling the pressure because of insufficient penetration into the liquid region, the highest jet speed is shown to be quite effective at disrupting thermal stratification and reducing the tank pressure in reasonable time. PMID:15644378

  10. Ventless pressure control of two-phase propellant tanks in microgravity

    NASA Technical Reports Server (NTRS)

    Kassemi, Mohammad; Panzarella, Charles H.

    2004-01-01

    This work studies pressurization and pressure control of a large liquid hydrogen storage tank. A finite element model is developed that couples a lumped thermodynamic formulation for the vapor region with a complete solution of the Navier-Stokes and energy equations for the flow and temperature fields in the liquid. Numerical results show that buoyancy effects are strong, even in microgravity, and can reposition a vapor bubble that is initially at the center of the tank to a region near the tank wall in a relatively short time. Long-term tank pressurization with the vapor bubble at the tank wall shows that after an initial transient lasting about a week, the final rate of pressure increase agrees with a purely thermodynamic analysis of the entire tank. However, the final pressure levels are quite different from thermodynamic predictions. Numerical results also show that there is significant thermal stratification in the liquid due to the effects of natural convection. A subcooled jet is used to provide simultaneous cooling and mixing in order to bring the tank pressure back down to its initial value. Three different jet speeds are examined. Although the lowest jet speed is ineffective at controlling the pressure because of insufficient penetration into the liquid region, the highest jet speed is shown to be quite effective at disrupting thermal stratification and reducing the tank pressure in reasonable time.

  11. Evaluating the Inhomogeneity of Thermocouples Using a Pressure-Controlled Water Heat Pipe

    NASA Astrophysics Data System (ADS)

    Tamba, J.; Yamazawa, K.; Masuyama, S.; Ogura, H.; Izuchi, M.

    2011-12-01

    There exists various research reports concerning the evaluation methods for the measurement uncertainty due to inhomogeneity of thermocouples; however, the universal method is still waiting to be established. This article considers the evaluation methods for the measurement uncertainty due to inhomogeneity of thermocouples based on comparison between results of two measurement methods. The first method is to estimate the uncertainty from the immersion characteristics of a thermocouple within a fixed-point furnace during its realization. The second method is to estimate the uncertainty from the immersion characteristics of a thermocouple within a heat-pipe furnace with a long uniform region. A pressure-controlled water heat-pipe furnace with an immersion depth of 1000 mm is developed to enable this work. It overcomes the technical difficulties that existed in applying conventional sealed heat pipes to such applications. From the immersion characteristics of a thermocouple measured by the above two methods, we have introduced three measurement parameters. Estimating the measurement uncertainty due to the inhomogeneity from our measurement results as examples is discussed.

  12. Managing blood pressure control in Asian patients: safety and efficacy of losartan.

    PubMed

    Cheung, Tommy Tsang; Cheung, Bernard Man Yung

    2014-01-01

    Hypertension is common in Asian populations and is a major cause of cardiovascular diseases. The prevalence of hypertension is increasing in many Asian countries. The overall prevalence of hypertension in India and the People's Republic of China has been estimated to be 20.6% in men and 22.6% in women. However, the rates of detection, treatment, and control of hypertension remain low in Asia. This reflects a low level of literacy and education, as well as a low level of access to medical care. To overcome these obstacles, strategies targeted at education, promotion, and optimization of medical care, are crucial to achieve target blood pressure control. Angiotensin receptor blockers are one of the first-line treatments for essential hypertension because they confer better cardiovascular outcomes. Losartan has been widely evaluated for the management of hypertension. Although some studies suggested that the blood pressure-lowering effect of losartan is perhaps lower than for other angiotensin receptor blockers, losartan has been demonstrated to be beneficial in terms of renal protection in patients with diabetes, heart failure resulting from either systolic or diastolic dysfunction, and diuretic-induced hyperuricemia. However, most of these data were obtained from Caucasian populations. The efficacy and safety of losartan in Asian populations may be different because of genetic and ethnic variations. Therefore, the efficacy and safety of losartan in Asian patients with hypertension warrant further study. PMID:24672231

  13. Managing blood pressure control in Asian patients: safety and efficacy of losartan

    PubMed Central

    Cheung, Tommy Tsang; Cheung, Bernard Man Yung

    2014-01-01

    Hypertension is common in Asian populations and is a major cause of cardiovascular diseases. The prevalence of hypertension is increasing in many Asian countries. The overall prevalence of hypertension in India and the People’s Republic of China has been estimated to be 20.6% in men and 22.6% in women. However, the rates of detection, treatment, and control of hypertension remain low in Asia. This reflects a low level of literacy and education, as well as a low level of access to medical care. To overcome these obstacles, strategies targeted at education, promotion, and optimization of medical care, are crucial to achieve target blood pressure control. Angiotensin receptor blockers are one of the first-line treatments for essential hypertension because they confer better cardiovascular outcomes. Losartan has been widely evaluated for the management of hypertension. Although some studies suggested that the blood pressure-lowering effect of losartan is perhaps lower than for other angiotensin receptor blockers, losartan has been demonstrated to be beneficial in terms of renal protection in patients with diabetes, heart failure resulting from either systolic or diastolic dysfunction, and diuretic-induced hyperuricemia. However, most of these data were obtained from Caucasian populations. The efficacy and safety of losartan in Asian populations may be different because of genetic and ethnic variations. Therefore, the efficacy and safety of losartan in Asian patients with hypertension warrant further study. PMID:24672231

  14. Sensitivity of rapidly acting arterial pressure control system in conscious adult rabbits at different ages.

    PubMed

    Hosomi, H; Katsuda, S; Motochigawa, H; Morita, H; Hayashida, Y

    1984-01-01

    Changes in sensitivity of the rapidly acting arterial pressure control (AP) system with aging were investigated. Two catheters, one for pressure measurement and the other for inducing hemorrhage from the aorta, were chronically implanted in 25 rabbits from the same colony (aged 6 to 30 months). A few days after the operations, each animal was quickly bled (2 ml/kg body weight) while it was conscious. The hemorrhage experiment was repeated 16 times and the mean arterial pressure responses were sampled with an A/D-converter and stored in a digital computer, the 16 strings of data being pooled for each animal. The overall open-loop gain (G) of the AP-system was estimated from the individually pooled responses. In the present study, aging exerted no significant effect on the value of G (7.1) as evaluated by Kruskal-Wallis' non-parametric one criterion variance analysis (p greater than 0.05). The reflex sensitivity of the AP-system over the pressure ranges used in this experiment thus appears to be unaffected by aging over the range from 6 to 30 months. PMID:6533380

  15. [Invasive ventilation. Classification, technique and clinical experiences with BiPAP/APRV (Biphasic Positive Airway Pressure/Airway Pressure Release Ventilation)].

    PubMed

    Antonsen, K; Jacobsen, E; Pedersen, J E; Porsborg, P A; Bonde, J

    1996-01-22

    BiPAP (bilevel or biphasic positive airway pressure) and APRV (airway pressure release ventilation) are new, and from a technical viewpoint closely related techniques recently introduced to the field of invasive ventilatory support. BiPAP/APRV can be described as a pressure controlled continuous high flow positive airway pressure system with a time-cycled change between a high inspiratory pressure level and a lower expiratory pressure level. Due to highly sensitive valves placed in the inspiratory and expiratory part of the system, unrestricted spontaneous breathing is possible at any moment of the mechanically supported ventilatory cycle. During invasive ventilation BiPAP offers potential advantages by allowing unrestricted spontaneous breathing thus reducing the need for sedation and facilitating weaning. APRV has primarily been investigated in conditions of moderate to severe acute lung injury and it seems that APRV is associated with less detrimental effects on the cardiopulmonary system compared to conventional ventilatory strategies. Apart from a review of the literature the article gives a classification and a technical description of the systems and focuses on the practical approach to BiPAP/APRV, e.g. the initiation and adjustment of respiratory support and the weaning from ventilatory support when applying these techniques. PMID:8638300

  16. Gastric rupture after bag-mask-ventilation

    PubMed Central

    Bednarz, Stephan; Filipovic, Miodrag; Schoch, Otto; Mauermann, Eckhard

    2015-01-01

    A 42 year old woman underwent bronchoscopy with procedural propofol sedation. During the procedure, the patient suffered respiratory arrest, and bag-mask ventilation was initiated. During forced mask ventilation, abdominal distention occurred. Even after correct placement of an endotracheal and a nasogastric tube, high inspiratory pressures persisted. The abdominal CT scan revealed a high amount of intraperitoneal free air. An emergent laparotomy confirmed a stomach rupture. Immediately after opening of the peritoneal cavity, peak ventilatory pressures decreased. In this case forceful bag-mask ventilation led to air insufflation into the stomach, increasing gastric pressure, and consecutive stomach rupture. PMID:26744639

  17. Implementation of a Hybrid Controller for Ventilation Control Using Soft Computing

    SciTech Connect

    Craig G. Rieger; D. Subbaram Naidu

    2005-06-01

    Many industrial facilities utilize pressure control gradients to prevent migration of hazardous species from containment areas to occupied zones, often using Proportional-Integral-Derivative (PID) control systems. When operators rebalance the facility, variation from the desired gradients can occur and the operating conditions can change enough that the PID parameters are no longer adequate to maintain a stable system. As the goal of the ventilation control system is to optimize the pressure gradients and associated flows for the facility, Linear Quadratic Tracking (LQT) is a method that provides a time-based approach to guiding facility interactions. However, LQT methods are susceptible to modeling and measurement errors, and therefore the additional use of Soft Computing methods are proposed for implementation to account for these errors and nonlinearities.

  18. A Multifunctional Frontloading Approach for Repeated Recycling of a Pressure-Controlled AFM Micropipette

    PubMed Central

    Roder, Phillip; Hille, Carsten

    2015-01-01

    Fluid force microscopy combines the positional accuracy and force sensitivity of an atomic force microscope (AFM) with nanofluidics via a microchanneled cantilever. However, adequate loading and cleaning procedures for such AFM micropipettes are required for various application situations. Here, a new frontloading procedure is described for an AFM micropipette functioning as a force- and pressure-controlled microscale liquid dispenser. This frontloading procedure seems especially attractive when using target substances featuring high costs or low available amounts. Here, the AFM micropipette could be filled from the tip side with liquid from a previously applied droplet with a volume of only a few μL using a short low-pressure pulse. The liquid-loaded AFM micropipettes could be then applied for experiments in air or liquid environments. AFM micropipette frontloading was evaluated with the well-known organic fluorescent dye rhodamine 6G and the AlexaFluor647-labeled antibody goat anti-rat IgG as an example of a larger biological compound. After micropipette usage, specific cleaning procedures were tested. Furthermore, a storage method is described, at which the AFM micropipettes could be stored for a few hours up to several days without drying out or clogging of the microchannel. In summary, the rapid, versatile and cost-efficient frontloading and cleaning procedure for the repeated usage of a single AFM micropipette is beneficial for various application situations from specific surface modifications through to local manipulation of living cells, and provides a simplified and faster handling for already known experiments with fluid force microscopy. PMID:26636981

  19. ORION Environmental Control and Life Support Systems Suit Loop and Pressure Control Analysis

    NASA Technical Reports Server (NTRS)

    Eckhardt, Brad; Conger, Bruce; Stambaugh, Imelda C.

    2015-01-01

    Under NASA's ORION Multi-Purpose Crew Vehicle (MPCV) Environmental Control and Life Support System (ECLSS) Project at Johnson Space Center's (JSC), the Crew and Thermal Systems Division has developed performance models of the air system using Thermal Desktop/FloCAD. The Thermal Desktop model includes an Air Revitalization System (ARS Loop), a Suit Loop, a Cabin Loop, and Pressure Control System (PCS) for supplying make-up gas (N2 and O2) to the Cabin and Suit Loop. The ARS and PCS are designed to maintain air quality at acceptable O2, CO2 and humidity levels as well as internal pressures in the vehicle Cabin and during suited operations. This effort required development of a suite of Thermal Desktop Orion ECLSS models to address the need for various simulation capabilities regarding ECLSS performance. An initial highly detailed model of the ARS Loop was developed in order to simulate rapid pressure transients (water hammer effects) within the ARS Loop caused by events such as cycling of the Pressurized Swing Adsorption (PSA) Beds and required high temporal resolution (small time steps) in the model during simulation. A second ECLSS model was developed to simulate events which occur over longer periods of time (over 30 minutes) where O2, CO2 and humidity levels, as well as internal pressures needed to be monitored in the cabin and for suited operations. Stand-alone models of the PCS and the Negative Pressure relief Valve (NPRV) were developed to study thermal effects within the PCS during emergency scenarios (Cabin Leak) and cabin pressurization during vehicle re-entry into Earth's atmosphere. Results from the Orion ECLSS models were used during Orion Delta-PDR (July, 2014) to address Key Design Requirements (KDR's) for Suit Loop operations for multiple mission scenarios.

  20. A Multifunctional Frontloading Approach for Repeated Recycling of a Pressure-Controlled AFM Micropipette.

    PubMed

    Roder, Phillip; Hille, Carsten

    2015-01-01

    Fluid force microscopy combines the positional accuracy and force sensitivity of an atomic force microscope (AFM) with nanofluidics via a microchanneled cantilever. However, adequate loading and cleaning procedures for such AFM micropipettes are required for various application situations. Here, a new frontloading procedure is described for an AFM micropipette functioning as a force- and pressure-controlled microscale liquid dispenser. This frontloading procedure seems especially attractive when using target substances featuring high costs or low available amounts. Here, the AFM micropipette could be filled from the tip side with liquid from a previously applied droplet with a volume of only a few μL using a short low-pressure pulse. The liquid-loaded AFM micropipettes could be then applied for experiments in air or liquid environments. AFM micropipette frontloading was evaluated with the well-known organic fluorescent dye rhodamine 6G and the AlexaFluor647-labeled antibody goat anti-rat IgG as an example of a larger biological compound. After micropipette usage, specific cleaning procedures were tested. Furthermore, a storage method is described, at which the AFM micropipettes could be stored for a few hours up to several days without drying out or clogging of the microchannel. In summary, the rapid, versatile and cost-efficient frontloading and cleaning procedure for the repeated usage of a single AFM micropipette is beneficial for various application situations from specific surface modifications through to local manipulation of living cells, and provides a simplified and faster handling for already known experiments with fluid force microscopy. PMID:26636981

  1. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) The power ventilation units shall not produce a source of vapor ignition in either the compartment or...(f). (d) Power ventilation shall be provided for each auxiliary machinery or working space located on... Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for...

  2. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) The power ventilation units shall not produce a source of vapor ignition in either the compartment or...(f). (d) Power ventilation shall be provided for each auxiliary machinery or working space located on... Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for...

  3. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  4. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  5. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  6. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  7. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  8. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  9. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  10. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  11. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  12. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (b) Whole-house ventilation. Each manufactured home must be provided with whole-house ventilation... combination passive and mechanical system. The ventilation system or provisions for ventilation must not... Zone 1. Mechanical systems must be balanced. Combination passive and mechanical systems must...

  13. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... (b) Whole-house ventilation. Each manufactured home must be provided with whole-house ventilation... combination passive and mechanical system. The ventilation system or provisions for ventilation must not... Zone 1. Mechanical systems must be balanced. Combination passive and mechanical systems must...

  14. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (b) Whole-house ventilation. Each manufactured home must be provided with whole-house ventilation... combination passive and mechanical system. The ventilation system or provisions for ventilation must not... Zone 1. Mechanical systems must be balanced. Combination passive and mechanical systems must...

  15. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  16. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  17. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  18. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  19. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  20. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts...

  1. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Ventilation-T/ALL. 38.20-10 Section 38.20-10 Shipping... Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for compartments... equipped with power ventilation of the exhaust type having capacity sufficient to effect a complete...

  2. 46 CFR 108.185 - Ventilation for enclosed classified locations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation for enclosed classified locations. 108.185... DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Ventilation § 108.185 Ventilation for enclosed classified locations. (a) The ventilation system for each enclosed classified location must...

  3. 30 CFR 77.1911 - Ventilation of slopes and shafts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation of slopes and shafts. 77.1911... COAL MINES Slope and Shaft Sinking § 77.1911 Ventilation of slopes and shafts. (a) All slopes and shafts shall be ventilated by mechanical ventilation equipment during development. Such equipment...

  4. 33 CFR 183.620 - Natural ventilation system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Natural ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.620 Natural ventilation system. (a) Except for compartments open to the atmosphere, a natural ventilation system that meets...

  5. 33 CFR 183.620 - Natural ventilation system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Natural ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.620 Natural ventilation system. (a) Except for compartments open to the atmosphere, a natural ventilation system that meets...

  6. 33 CFR 183.620 - Natural ventilation system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Natural ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.620 Natural ventilation system. (a) Except for compartments open to the atmosphere, a natural ventilation system that meets...

  7. 33 CFR 183.620 - Natural ventilation system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Natural ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.620 Natural ventilation system. (a) Except for compartments open to the atmosphere, a natural ventilation system that meets...

  8. 33 CFR 183.620 - Natural ventilation system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Natural ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.620 Natural ventilation system. (a) Except for compartments open to the atmosphere, a natural ventilation system that meets...

  9. 46 CFR 153.316 - Special cargo pumproom ventilation rate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Equipment Cargo Handling Space Ventilation § 153.316 Special cargo pumproom ventilation rate. When Table 1 refers to this section, the cargo pumproom ventilation system must change the air in the cargo pumproom... 46 Shipping 5 2010-10-01 2010-10-01 false Special cargo pumproom ventilation rate. 153.316...

  10. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b)...

  11. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... need be applied to the damper blade. (c) Where ventilation ducts are required to meet bulkhead.... The indicator may be connected to the manual operating device rather than the damper blade so that...

  12. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... need be applied to the damper blade. (c) Where ventilation ducts are required to meet bulkhead.... The indicator may be connected to the manual operating device rather than the damper blade so that...

  13. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... need be applied to the damper blade. (c) Where ventilation ducts are required to meet bulkhead.... The indicator may be connected to the manual operating device rather than the damper blade so that...

  14. Exercise oscillatory ventilation in heart failure.

    PubMed

    Corrà, Ugo

    2016-03-01

    Ventilation inefficiency has become a matter of interest for heart failure (HF) specialists, the most remarkable being exertional oscillatory ventilation (EOV). EOV is an abnormal ventilatory phenomenon, originally described as anecdotal, but now considered a marker of disease severity and worst prognosis in HF. EOV is a cyclic fluctuation of minute ventilation (VE) and expired gas kinetics occurring during exercise: it is a slow, prominent, consistent rather than random, fluctuation in VE that may be evanescent or transient and can follow several distinct patterns. In contrast to the periodic breathing observed in Cheyne-Stokes respiration and central sleep apnea, the gradual increase and decrease in minute ventilation (VE) are not spaced by periods of apnea. This review will discuss EOV in HF and the overlap with Cheyne-Stokes respiration. PMID:26935880

  15. [Mechanical ventilation at home: facts and questions].

    PubMed

    Fitting, J W

    1993-06-15

    Treatment of respiratory insufficiency with retention of CO2 by mechanic ventilation has come into use over the last decade, favored by use of non-invasive methods like nasal ventilation. Best results have been observed in hypercapnic respiratory insufficiency caused by neuromuscular disease or restrictive pathologic changes of the lung. Nocturnal use of nasal ventilation alone is often sufficient to correct also the daily CO2-values. Mechanisms explaining this beneficial effect are not yet known-The respiratory CNS-centers, respiratory muscles or thoracopulmonary mechanics may play etiologically an important role. Medical indications for nasal ventilation in chronic obstructive pulmonary disease are not clear, since results from several studies are controversial. Also in severe or progressive neurologic diseases a critical evaluation is mandatory for assessment of benefits including improvement of quality of life. PMID:8327808

  16. Mechanical ventilation and mobilization: comparison between genders

    PubMed Central

    Daniel, Christiane Riedi; Alessandra de Matos, Carla; Barbosa de Meneses, Jessica; Bucoski, Suzane Chaves Machado; Fréz, Andersom Ricardo; Mora, Cintia Teixeira Rossato; Ruaro, João Afonso

    2015-01-01

    [Purpose] To investigate the impact of gender on mobilization and mechanical ventilation in hospitalized patients in an intensive care unit. [Subjects and Methods] A retrospective cross-sectional study was conducted of the medical records of 105 patients admitted to a general intensive care unit. The length of mechanical ventilation, length of intensive care unit stay, weaning, time to sitting out of bed, time to performing active exercises, and withdrawal of sedation exercises were evaluated in addition to the characteristics of individuals, reasons for admission and risk scores. [Results] Women had significantly lower values APACHE II scores, duration of mechanical ventilation, time to withdrawal of sedation and time to onset of active exercises. [Conclusion] Women have a better functional response when admitted to the intensive care unit, spending less time ventilated and performing active exercises earlier. PMID:25995558

  17. Innovative ventilation system for animal anatomy laboratory

    SciTech Connect

    Lacey, D.R.; Smith, D.C.

    1997-04-01

    A unique ventilation system was designed and built to reduce formaldehyde fumes in the large animal anatomy lab at the Vet Medical Center at Cornell University. The laboratory includes four rooms totaling 5,500 ft{sup 2}. The main room has 2,300 ft{sup 2} and houses the laboratory where up to 60 students dissect as many as 12 horses at a time. Other rooms are a cold storage locker, an animal preparation room and a smaller lab for specialized instruction. The large animal anatomy laboratory has a history of air quality complaints despite a fairly high ventilation rate of over 10 air changes/hour. The horses are embalmed, creating a voluminous source of formaldehyde and phenol vapors. Budget constraints and increasingly stringent exposure limits for formaldehyde presented a great challenge to design a ventilation system that yields acceptable air quality. The design solution included two innovative elements: air-to-air heat recovery, and focused ventilation.

  18. 'Elective' ventilation: an unethical and harmful misnomer?

    PubMed

    Stammers, Trevor

    2013-01-01

    The demand for organs prompted the first use of elective ventilation in the UK in the 1990s. Recently the shortfall in supply of organs has once again prompted calls for elective ventilation to be instituted even in patients who are not brain dead. This paper proposes that the term 'elective' ventilation is a misnomer and the term non-therapeutic ventilation (NTV) should be used instead. It is further argued that the practice of NTV in cases of severe stroke is unethical and has the potential of causing a variety of harms to the patient, their relatives, and the healthcare professionals working in transplant teams and this may result in a backlash of reductions in the number of organ donations. PMID:25109129

  19. EVALUATION OF VENTILATION PERFORMANCE FOR INDOOR SPACE

    EPA Science Inventory

    The paper discusses a personal-computer-based application of computational fluid dynamics that can be used to determine the turbulent flow field and time-dependent/steady-state contaminant concentration distributions within isothermal indoor space. (NOTE: Ventilation performance ...

  20. Using a Ventilation Controller to Optimize Residential Passive Ventilation For Energy and Indoor Air Quality

    SciTech Connect

    Turner, William; Walker, Iain

    2014-08-01

    One way to reduce the energy impact of providing residential ventilation is to use passive and hybrid systems. However, these passive and hybrid (sometimes called mixed-mode) systems must still meet chronic and acute health standards for ventilation. This study uses a computer simulation approach to examine the energy and indoor air quality (IAQ) implications of passive and hybrid ventilation systems, in 16 California climate zones. Both uncontrolled and flow controlled passive stacks are assessed. A new hybrid ventilation system is outlined that uses an intelligent ventilation controller to minimise energy use, while ensuring chronic and acute IAQ standards are met. ASHRAE Standard 62.2-2010 – the United States standard for residential ventilation - is used as the chronic standard, and exposure limits for PM2.5, formaldehyde and NO2 are used as the acute standards.The results show that controlled passive ventilation and hybrid ventilation can be used in homes to provide equivalent IAQ to continuous mechanical ventilation, for less use of energy.

  1. Sensor-based demand controlled ventilation

    SciTech Connect

    De Almeida, A.T.; Fisk, W.J.

    1997-07-01

    In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

  2. Humidification of inspired gases during mechanical ventilation.

    PubMed

    Gross, J L; Park, G R

    2012-04-01

    Humidification of inspired gas is mandatory for all mechanically ventilated patients to prevent secretion retention, tracheal tube blockage and adverse changes occurring to the respiratory tract epithelium. However, the debate over "ideal" humidification continues. Several devices are available that include active and passive heat and moisture exchangers and hot water humidifiers Each have their advantages and disadvantages in mechanically ventilated patients. This review explores each device in turn and defines their role in clinical practice. PMID:22269929

  3. Evaluating Ventilation Systems for Existing Homes

    SciTech Connect

    Aldrich, Robb; Arena, Lois

    2013-02-01

    In an effort to improve housing options near Las Vegas, Nevada, the Clark County Community Resources Division (CCCRD) performs substantial renovations to foreclosed homes. After dramatic energy, aesthetic, and health and safety improvements are made, homes are rented or sold to qualified residents. This report describes the evaluation and selection of ventilation systems for these homes, including key considerations when selecting an ideal system. The report then describes CCCRD’s decision process with respect to ventilation.

  4. Ventilation criteria for IDMS facility

    SciTech Connect

    Lambert, D.P.

    1996-07-03

    Both Facility Evaluation Board (FEB) reviews of the Integrated DWPF Melter System (IDMS) have identified the inconsistency of the current IDMS Process Hazards Review (PHR) versus actual IDMS practice as regards the criteria to contain air borne pollutants that may be present in the Process Room (e.g. benzene and mercury). The PHR states that a 1.0 in. wc pressure differential be maintained between the IDMS Process Room and Building 672-T. In addition, the PHR further specifies that the linear velocity through openings into the Process Room (e.g. open doors) be equal to or greater than 150 fpm. Finally, the PHR recommended that mercury vapor and benzene monitors be installed in the Process Room ventilation exhaust to alert personnel to the presence of vapors of benzene and/or mercury before entering the Process Room. This report summarizes the results of reassessment of these criteria and the specific recommendation for permanent installation of mercury and benzene vapor monitors in the vapor exhaust of the Process Room.

  5. Pretest Predictions for Phase II Ventilation Tests

    SciTech Connect

    Yiming Sun

    2001-09-19

    The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, and concrete pipe walls that will be developed during the Phase II ventilation tests involving various test conditions. The results will be used as inputs to validating numerical approach for modeling continuous ventilation, and be used to support the repository subsurface design. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the Phase II ventilation tests, and describe numerical methods that are used to calculate the effects of continuous ventilation. The calculation is limited to thermal effect only. This engineering work activity is conducted in accordance with the ''Technical Work Plan for: Subsurface Performance Testing for License Application (LA) for Fiscal Year 2001'' (CRWMS M&O 2000d). This technical work plan (TWP) includes an AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', activity evaluation (CRWMS M&O 2000d, Addendum A) that has determined this activity is subject to the YMP quality assurance (QA) program. The calculation is developed in accordance with the AP-3.12Q procedure, ''Calculations''. Additional background information regarding this activity is contained in the ''Development Plan for Ventilation Pretest Predictive Calculation'' (DP) (CRWMS M&O 2000a).

  6. The impact of private use of PCV7 in 2009 and 2010 on serotypes and antimicrobial resistance of Streptococcus pneumoniae carried by young children in Portugal: Comparison with data obtained since 1996 generating a 15-year study prior to PCV13 introduction.

    PubMed

    Nunes, Sónia; Félix, Sofia; Valente, Carina; Simões, Alexandra S; Tavares, Débora A; Almeida, Sónia T; Paulo, Ana C; Brito-Avô, António; de Lencastre, Hermínia; Sá-Leão, Raquel

    2016-03-29

    In Portugal, the 7-valent pneumococcal conjugate vaccine (PCV7) was not introduced in the national immunization plan but was commercially available between 2001 and 2010. We studied serotype distribution and antibiotic susceptibility of Streptococcus pneumoniae carried by children in 2009 and 2010. Vaccination with PCV7 was extracted from children's immunization bulletins and information on recent antimicrobial consumption was obtained through a questionnaire. For comparison, we included data from previous studies conducted since 1996: 1996-1999, 2001-2003, 2006-2007. Pneumococci were isolated from nasopharyngeal samples of 1092 children up to six years old attending day-care in an urban area. Among these, 76% (819/1070) were vaccinated and 62% (677/1092) carried pneumococci. In 2009-2010, serotype replacement was extensive. Carriage of PCV7 serotypes was 4.9% and 5.8%, in 2009 and 2010, respectively, with the majority being of serotype 19F (carried by 4.3% and 4.6% of all participants, respectively). Colonization by serotype 19F was associated with vaccine status (7.7% (19/248) of non-vaccinees vs. 3.5% (29/818) of PCV7-vaccinees, p=0.010). Carriage of serotype 19A was high in 2009 and 2010 (8.6% of all participants) consistent with values already observed in 2007; carriage of serotype 6A was <1% (10/1092), indicating a major decline after 2007 (5.8% or 31/538, p<0.001). Non-vaccine serotypes increased and serotype 6C became the most frequently carried serotype in 2010 (11.2% (54/481)). High-level resistance to penicillin (MIC ≥2mg/L) showed a decreasing trend (p<0.001), whereas resistance to both penicillin and erythromycin increased (p<0.001) and was detected in 15-20% of all isolates in 2009-2010, most of which were non-vaccine serotypes. Antimicrobial use decreased over time (p<0.001). In conclusion, widespread private use of PCV7 has impacted on colonization leading to near elimination of all PCV7 serotypes except for serotype 19F. Antimicrobial consumption declined but it may be too soon to observe generalized changes in antimicrobial resistance rates. PMID:26920470

  7. Observational Modeling of Strict vs. Conventional Blood Pressure Control in Patients with Chronic Kidney Disease

    PubMed Central

    Kovesdy, Csaba P.; Lu, Jun L.; Molnar, Miklos Z.; Ma, Jennie Z.; Canada, Robert B.; Streja, Elani; Kalantar-Zader, Kamyar; Bleyer, Anthony J.

    2014-01-01

    Importance The effect of strict blood pressure control on clinical outcomes in patients with chronic kidney disease (CKD) is unclear. Objective To examine the association of a treated systolic blood pressure (SBP) of <120 mmHg with the currently recommended SBP of <140 mmHg in a national CKD database of United States veterans. Design Historical cohort. Setting All US Department of Veterans Affairs healthcare facilities. Participants Using a database of 651,749 CKD patients, we identified 77,765 individuals with estimated GFR<60 ml/min/1.73m2 and uncontrolled hypertension, who then had administration of one or more additional blood pressure medications with evidence of a decrease in systolic blood pressure. 5,760 patients experienced follow-up treated blood pressure of <120 mmHg and 72,005 patients had SBP 120–139 mmHg. Propensity scores were calculated to reflect each individual’s probability for future SBP<120 vs. 120–139 mmHg. Main outcome measures The effect of SBP on all-cause mortality was evaluated by the log-rank test, and in Cox models adjusted for propensity scores. Results A total of 19,517 patients died during a median follow-up of 6.0 years, with 2,380 deaths in the SBP <120 mmHg group (death rate, 95%CI: 80.9/1000 patient-years, 77.7–84.2) and 17,137 deaths in the SBP 120–<140 mmHg group (41.8/1000 patient-years, 41.2–42.4), p< 0.001. The mortality hazard ratio (95%CI) associated with follow-up SBP<120 vs. 120–139 mmHg was 1.70 (95%CI: 1.63–1.78) after adjustment for propensity scores. Conclusion and Relevance Our results suggest that stricter SBP control is associated with higher all-cause mortality in CKD patients. Confirmation of these findings by ongoing clinical trials would suggest that modeling of therapeutic interventions in observational cohorts may offer useful guidance for the treatment of conditions which lack clinical trial data. PMID:25089540

  8. Intraocular Pressure Control after Trabeculectomy, Phacotrabeculectomy and Phacoemulsification in a Hispanic Population

    PubMed Central

    L Jung, Jennifer; Isida-Llerandi, Cristina G; Lazcano-Gomez, Gabriel; SooHoo, Jeffrey R

    2014-01-01

    ABSTRACT Purpose: To compare the efficacy of different surgical strategies for intraocular pressure (IOP) control in Hispanic glaucoma patients with and without visually significant cataracts. Design: Comparative retrospective consecutive case series. Methods: The charts of 153 consecutive patients with primary open angle glaucoma who underwent either trabeculectomy alone (n = 51), phacotrabeculectomy (n = 51), or phacoemulsification alone (n = 51) were reviewed to compare IOP control, the number of glaucoma medications required postoperatively, and the inci dence of surgical complications. Results: Preoperative IOP was 17.5 ± 5.2 mm Hg in the trabe-culectomy group, 15.4 ± 4.5 mm Hg in the phacotrabeculectomy group and 13.9 ± 2.9 mm Hg in the phacoemulsification group (p < 0.001 for all comparisons). Mean IOP reduction from baseline was 4.2 ± 6.9 (24.6%) for the trabeculectomy group, 2.9 ± 5.0 (20.8%) for the phacotrabeculectomy group, and 0.9 ± 3.4 (6.5%) for the phacoemulsification group (p = 0.009). The number of IOP-lowering medications required postoperatively decreased significantly in all three groups (p = 0.001). The rate of early and late postoperative complications was similar between the trabeculectomy and phacotrabeculectomy groups and less for the phacoemulsification group. Conclusion: Trabeculectomy and phacotrabeculectomy are both viable surgical options for managing open angle glau coma. Both resulted in similar rates of success, IOP reduction, decrease in use of IOP-lowering medications and post operative complication rates. Phacoemulsification alone had a lower success rate and greater need for postoperative IOP-lowering medications compared to trabeculectomy alone or phacotrabeculectomy. Phacoemulsification alone may be a reasonable option for patients with visually significant cataract and lower baseline IOP. How to cite this article: Jung JL, Isida-Llerandi CG, Lazcano-Gomez G, SooHoo JR, Kahook MY. Intraocular Pressure Control after Trabeculectomy, Phacotrabeculectomy and Phaco-emulsification in a Hispanic Population. J Curr Glaucoma Pract 2014;8(2):67-74.

  9. Comparison of prophylactic effects of polyurethane cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes on ventilator-associated pneumonia.

    PubMed

    Mahmoodpoor, Ata; Peyrovi-far, Ali; Hamishehkar, Hadi; Bakhtyiari, Zhaleh; Mirinezhad, Mir Mousa; Hamidi, Masoud; Golzari, Samad Eslam Jamal

    2013-01-01

    Because microaspiration of contaminated supraglottic secretions past the endotracheal tube cuff is considered to be central in the pathogenesis of pneumonia, improved design of tracheal tubes with new cuff material and shape have reduced the size and number of folds, which together with the addition of suction ports above the cuff to drain pooled subglottic secretions leads to reduced aspiration of oropharyngeal secretions. So we conducted a study to compare the prophylactic effects of polyurethane-cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes (ETT) on ventilator-associated pneumonia. This randomized clinical trial was carried out in a 12 bed surgical intensive care unit. 96 patients expected to require mechanical ventilation more than 96 hours were randomly allocated to one of three following groups: Polyvinyl chloride cuff (PCV) ETT, Polyurethane (PU) cylindrical Sealguard ETT and PU Taperguard ETT. Cuff pressure monitored every three hours 3 days in all patients. Mean cuff pressure didn't have significant difference between three groups during 72 hours. Pneumonia was seen in 11 patients (34%) in group PVC, 8 (25%) in Sealguard and 7 (21%) in Taperguard group. Changes in mean cuff pressure between Sealguard and PVC tubes and also between Taperguard and PVC tubes did not show any significant difference. There was no significant difference in overinflation between three groups. The use of ETT with PU material results in reducing ventilator-associated pneumonia compared to ETT with PVC cuff. In PU tubes Taperguard has less incidence of ventilator-associated pneumonia compared to Sealguard tubes. PMID:23945890

  10. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam M.

    2011-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications, including the treatment of medical conditions. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy available in the developing world for the treatment of a variety of medical conditions. Specifically, hyperbaric oxygen therapy is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. Hyperbaric oxygen therapy is simply too expensive and too dangerous to implement in the developing world using standard equipment. The hydrostatic hyperbaric chamber technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system that will provide controlled pressurization of the system, and provide adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware, supports sustainability.

  11. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware, supports sustainability.

  12. Carbon-dioxide-controlled ventilation study

    SciTech Connect

    McMordie, K.L.; Carroll, D.M.

    1994-05-01

    The In-House Energy Management (IHEM) Program has been established by the U.S. Department of Energy to provide funds to federal laboratories to conduct research on energy-efficient technology. The Energy Sciences Department of Pacific Northwest Laboratory (PNL) was tasked by IHEM to research the energy savings potential associated with reducing outdoor-air ventilation of buildings. By monitoring carbon dioxide (CO{sub 2}) levels in a building, outdoor air provided by the heating, ventilating, and air-conditioning (HVAC) system can be reduced to the percentage required to maintain satisfactory CO{sub 2} levels rather than ventilating with a higher outdoor-air percentage based on an arbitrary minimum outdoor-air setting. During summer months, warm outdoor air brought into a building for ventilation must be cooled to meet the appropriate cooling supply-air temperature, and during winter months, cold outdoor air must be heated. By minimizing the amount of hot or cold outdoor air brought into the HVAC system, the supply air requires less cooling or heating, saving energy and money. Additionally, the CO{sub 2} levels in a building can be monitored to ensure that adequate outdoor air is supplied to a building to maintain air quality levels. The two main considerations prior to implementing CO{sub 2}-based ventilation control are its impact on energy consumption and the adequacy of indoor air quality (IAQ) and occupant comfort. To address these considerations, six portable CO{sub 2} monitors were placed in several Hanford Site buildings to estimate the adequacy of office/workspace ventilation. The monitors assessed the potential for reducing the flow of outdoor-air to the buildings. A candidate building was also identified to monitor various ventilation control strategies for use in developing a plan for implementing and assessing energy savings.

  13. [Tube-free translaryngeal superposed jet ventilation].

    PubMed

    Aloy, A; Schachner, M; Spiss, C K; Cancura, W

    1990-10-01

    Microsurgical operations on the larynx require sufficient space for the surgeon in order to achieve the best surgical result. After preliminary experimental studies we integrated two jets of a specific size into the Kleinsasser tube. Simultaneously, we developed a "superimposed jet-ventilation system", which consists of a low-frequency jet ventilation and superimposed high-frequency jet ventilation. Respiration was maintained with a mixture of oxygen and air, whereby an additional increase in air and volume via the Kleinsasser tube, which is open on the outside, can be sustained on account of the Venturi effect. We tested this tubeless translaryngeal superimposed jet-ventilation system in 48 patients. Anesthesia was carried out by continuous intravenous administration of Propofol and intermittent doses of Sufentanil and Vecuronium as required. The clinical results showed optimal ventilation without hypercapnia. The arterial pC0(2) levels were below 42 mmHg. The arterial p0(2) levels were above 120 mmHg with a FIO2 of 40%. No complications were observed with regard to respiration during any of the operations. The surgeon had optimal conditions to carry out the operation. Because of the absence of a plastic tube, inhalation anesthetics and nitrous oxide, laryngeal laser surgery is another field of application for which this form of tubeless jet ventilation is excellently suited. We tested it with 12 patients, and no complications due to laser anesthesia were observed. We consider this form of a tubeless superimposed translaryngeal jet ventilation to be a great improvement in microlaryngeal surgery. PMID:2278368

  14. Regenerative Blower for EVA Suit Ventilation Fan

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  15. Population Structure of Streptococcus pneumoniae Causing Invasive Disease in Adults in Portugal before PCV13 Availability for Adults: 2008-2011.

    PubMed

    Horácio, Andreia N; Silva-Costa, Catarina; Diamantino-Miranda, Jorge; Lopes, Joana P; Ramirez, Mario; Melo-Cristino, José

    2016-01-01

    Among the 1660 isolates recovered from invasive pneumococcal disease (IPD) in adults (> = 18 yrs) in 2008-2011, a random sample of ≥50% of each serotype (n = 871) was chosen for MLST analysis and evaluation for the presence and type of pilus islands (PIs). The genetic diversity was high with 206 different sequence types (STs) detected, but it varied significantly between serotypes. The different STs represented 80 clonal complexes (CCs) according to goeBURST with the six more frequent accounting for more than half (50.6%) of the isolates-CC156 (serotypes 14, 9V and 23F), CC191 (serotype 7F), CC180 (serotype 3), CC306 (serotype 1), CC62 (serotypes 8 and 11A) and CC230 (serotype 19A). Most of the isolates (n = 587, 67.3%) were related to 29 Pneumococcal Molecular Epidemiology Network recognized clones. The overall proportion of isolates positive for any of the PIs was small (31.9%) and declined gradually during the study period (26.6% in 2011), mostly due to the significant decline of serotype 1 which is associated with PI-2. The changes in serotypes that occurred in adult IPD after the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) for children were mostly due to the expansion of previously circulating clones, while capsular switching was infrequent and not related to vaccine use. The reduction of IPD caused by PCV7 serotypes in the years following PCV7 implementation did not result in a decline of antimicrobial resistance in part due to the selection of resistant genotypes among serotypes 14 and 19A. PMID:27168156

  16. Predictors to parental knowledge about childhood immunisation/EPI vaccines in two health districts in Cameroon prior to the introduction of 13-valent Pneumococcal Conjugate Vaccines (PCV-13)

    PubMed Central

    Libwea, John Njuma; Kobela, Marie; Ollgren, Jukka; Emah, Irene; Tchio, Robert; Nohynek, Hanna

    2014-01-01

    Introduction Pneumonia is vaccine-preventable, but the increasing death toll resulting from the disease in Sub-Saharan Africa is alarming. Several factors account for vaccine failing to reach every child, besides incomplete vaccine coverage. Most of these include the perceptions of parents/guardians and healthcare providers. Previous studies on the introduction of new vaccines have focused on experimental trials, coverage figures and vaccine efficacy in developed countries. Little is known on the factors which may hinder the implementation process despite the huge challenges this may encounter in developing countries. This study described the knowledge, attitude and practices (KAP) of parents/guardians on pneumonia and immunisations/EPI vaccines; identify predictive parental socio-economic/demographic characteristics that of good knowledge on pneumonia infections, routine EPI vaccines and the PCV-13. Finally, the study described health center personnel perceptions about immunisations. Methods The WHO's immunisation coverage cluster survey design was used, involving parents/guardians (n = 205) of children aged 0-59 months and health centre personnel (n = 13) directly concerned with vaccination activities between July-September 2010 in two health districts in Yaounde, Cameroon. Descriptive statistics and multivariate logistic models were used to analyse the parental/guardian data while the health personnel data was only analysed descriptively using SPSS version 17.0. Results Only 19% of the parents/guardians were aware of the availability of the PCV-13. Logistic modelling identified important associations between parental socio-economic/demographic factors and good knowledge on pneumonia disease burden and prevention. Conclusion According to parents/guardians a short and clear message on the dangers of pneumonia and the need for prevention provided to parents/guardians during sensitisation/out-reach campaigns and use of social network avenues would be primordial, if the PCV-13 is to reach every child. PMID:25396013

  17. Population Structure of Streptococcus pneumoniae Causing Invasive Disease in Adults in Portugal before PCV13 Availability for Adults: 2008-2011

    PubMed Central

    Horácio, Andreia N.; Silva-Costa, Catarina; Diamantino-Miranda, Jorge; Lopes, Joana P.; Ramirez, Mario; Melo-Cristino, José

    2016-01-01

    Among the 1660 isolates recovered from invasive pneumococcal disease (IPD) in adults (> = 18 yrs) in 2008–2011, a random sample of ≥50% of each serotype (n = 871) was chosen for MLST analysis and evaluation for the presence and type of pilus islands (PIs). The genetic diversity was high with 206 different sequence types (STs) detected, but it varied significantly between serotypes. The different STs represented 80 clonal complexes (CCs) according to goeBURST with the six more frequent accounting for more than half (50.6%) of the isolates—CC156 (serotypes 14, 9V and 23F), CC191 (serotype 7F), CC180 (serotype 3), CC306 (serotype 1), CC62 (serotypes 8 and 11A) and CC230 (serotype 19A). Most of the isolates (n = 587, 67.3%) were related to 29 Pneumococcal Molecular Epidemiology Network recognized clones. The overall proportion of isolates positive for any of the PIs was small (31.9%) and declined gradually during the study period (26.6% in 2011), mostly due to the significant decline of serotype 1 which is associated with PI-2. The changes in serotypes that occurred in adult IPD after the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) for children were mostly due to the expansion of previously circulating clones, while capsular switching was infrequent and not related to vaccine use. The reduction of IPD caused by PCV7 serotypes in the years following PCV7 implementation did not result in a decline of antimicrobial resistance in part due to the selection of resistant genotypes among serotypes 14 and 19A. PMID:27168156

  18. Ventilation efficiencies of a desk-edge-mounted task ventilation system

    SciTech Connect

    Faulkner, David; Fisk, William J.; Sullivan, Douglas P.; Lee, Seung Min

    2002-03-01

    In chamber experiments, we investigated the effectiveness of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air toward a heated mannequin seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15{sup o} to 45{sup o} from horizontal), and the supply flow rate of (3.5 to 6.5 L s{sup -1}). Using the tracer gas step-up and step-down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air at the mannequin's face) ranged from 1.4 to 2.7, which is higher than typically reported for commercially available task ventilation or displacement ventilation systems.

  19. Evaluation of anticipatory signal to steam generator pressure control program for 700 MWe Indian pressurized heavy water reactor

    SciTech Connect

    Pahari, S.; Hajela, S.; Rammohan, H. P.; Malhotra, P. K.; Ghadge, S. G.

    2012-07-01

    700 MWe Indian Pressurized Heavy Water Reactor (IPHWR) is horizontal channel type reactor with partial boiling at channel outlet. Due to boiling, it has a large volume of vapor present in the primary loops. It has two primary loops connected with the help of pressurizer surge line. The pressurizer has a large capacity and is partly filled by liquid and partly by vapor. Large vapor volume improves compressibility of the system. During turbine trip or load rejection, pressure builds up in Steam Generator (SG). This leads to pressurization of Primary Heat Transport System (PHTS). To control pressurization of SG and PHTS, around 70% of the steam generated in SG is dumped into the condenser by opening Condenser Steam Dump Valves (CSDVs) and rest of the steam is released to the atmosphere by opening Atmospheric Steam Discharge Valves (ASDVs) immediately after sensing the event. This is accomplished by adding anticipatory signal to the output of SG pressure controller. Anticipatory signal is proportional to the thermal power of reactor and the proportionality constant is set so that SG pressure controller's output jacks up to ASDV opening range when operating at 100% FP. To simulate this behavior for 700 MWe IPHWR, Primary and secondary heat transport system is modeled. SG pressure control and other process control program have also been modeled to capture overall plant dynamics. Analysis has been carried out with 3-D neutron kinetics coupled thermal hydraulic computer code ATMIKA.T to evaluate the effect of the anticipatory signal on PHT pressure and over all plant dynamics during turbine trip in 700 MWe IPHWR. This paper brings out the results of the analysis with and without considering anticipatory signal in SG pressure control program during turbine trip. (authors)

  20. Increasing the Time Interval between PCV Chemotherapy Cycles as a Strategy to Improve Duration of Response in Low-Grade Gliomas: Results from a Model-Based Clinical Trial Simulation

    PubMed Central

    Mazzocco, Pauline; Honnorat, Jrme; Ducray, Franois; Ribba, Benjamin

    2015-01-01

    Background. We previously developed a mathematical model capturing tumor size dynamics of adult low-grade gliomas (LGGs) before and after treatment either with PCV (Procarbazine, CCNU, and Vincristine) chemotherapy alone or with radiotherapy (RT) alone. Objective. The aim of the present study was to present how the model could be used as a simulation tool to suggest more effective therapeutic strategies in LGGs. Simulations were performed to identify schedule modifications that might improve PCV chemotherapy efficacy. Methods. Virtual populations of LGG patients were generated on the basis of previously evaluated parameter distributions. Monte Carlo simulations were performed to compare treatment efficacy across in silico clinical trials. Results. Simulations predicted that RT plus PCV would be more effective in terms of duration of response than RT alone. Additional simulations suggested that, in patients treated with PCV chemotherapy, increasing the interval between treatment cycles up to 6 months from the standard 6 weeks can increase treatment efficacy. The predicted median duration of response was 4.3 years in LGGs treated with PCV cycles given every 6 months versus 3.1 years in patients treated with the classical regimen. Conclusion. The present study suggests that, in LGGs, mathematical modeling could facilitate clinical research by helping to identify, in silico, potentially more effective therapeutic strategies. PMID:26788118

  1. Anesthesia and critical care ventilator modes: past, present, and future.

    PubMed

    Bristle, Timothy J; Collins, Shawn; Hewer, Ian; Hollifield, Kevin

    2014-10-01

    Mechanical ventilators have evolved from basic machines to complicated, electronic, microprocessing engines. Over the last 2 decades, ventilator capabilities and options for critical care and anesthesia ventilators have rapidly advanced. These advances in ventilator modalities--in conjunction with a better understanding of patient physiology and the effects of positive pressure ventilation on the body--have revolutionized the mechanical ventilation process. Clinicians today have a vast array of mechanical ventilator mode options designed to match the pulmonary needs of the critically ill and anesthetized patient. Modes of mechanical ventilation continue to be based on 1 of 2 variances: volume-based or pressure-based. The wording describing the standard ventilatory modes on select present-day ventilators has changed, yet the basic principles of operation have not changed compared with older ventilators. Anesthesia providers need to understand these ventilator modes to best care for patients. This literature review encompasses a brief history of mechanical ventilation and current modes available for anesthesia and critical care ventilators, including definitions of each mode, definitions of the various descriptive labels given each mode, and techniques for optimizing and meeting the ventilator needs of the patient while avoiding complications in the surgical and critical care patient. PMID:25842654

  2. A Porcine Model for Initial Surge Mechanical Ventilator Assessment and Evaluation of Two Limited Function Ventilators

    PubMed Central

    Dickson, Robert P; Hotchkin, David L; Lamm, Wayne JE; Hinkson, Carl; Pierson, David J; Glenny, Robb W; Rubinson, Lewis

    2013-01-01

    Objective To adapt an animal model of acute lung injury for use as a standard protocol for a screening, initial evaluation of limited function, or “surge,” ventilators for use in mass casualty scenarios. Design Prospective, experimental animal study. Setting University research laboratory. Subjects 12 adult pigs. Interventions 12 spontaneously breathing pigs (6 in each group) were subjected to acute lung injury/acute respiratory distress syndrome (ALI/ARDS) via pulmonary artery infusion of oleic acid. Following development of respiratory failure, animals were mechanically ventilated with a limited function ventilator (Simplified Automatic Ventilator [SAVe] I or II; Automedx) for one hour or until the ventilator could not support the animal. The limited function ventilator was then exchanged for a full function ventilator (Servo 900C; Siemens). Measurements and Main Results Reliable and reproducible levels of ALI/ARDS were induced. The SAVe I was unable to adequately oxygenate 5 animals, with PaO2 (52.0 ± 11.1 torr) compared to the Servo (106.0 ± 25.6 torr; p=0.002). The SAVe II was able to oxygenate and ventilate all 6 animals for one hour with no difference in PaO2 (141.8 ± 169.3 torr) compared to the Servo (158.3 ± 167.7 torr). Conclusions We describe a novel in vivo model of ALI/ARDS that can be used to initially screen limited function ventilators considered for mass respiratory failure stockpiles, and is intended to be combined with additional studies to defintively assess appropriateness for mass respiratory failure. Specifically, during this study we demonstrate that the SAVe I ventilator is unable to provide sufficient gas exchange, while the SAVe II, with several more functions, was able to support the same level of hypoxemic respiratory failure secondary to ALI/ARDS for one hour. PMID:21187747

  3. WASTE HANDLING BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    P.A. Kumar

    2000-06-21

    The Waste Handling Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Handling Building (WHB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for equipment operation and personnel comfort, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WHB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement areas ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination within the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WHB. The Waste Handling Building Ventilation System is designed to perform its safety functions under accident conditions and other Design Basis Events (DBEs) (such as earthquakes, tornadoes, fires, and loss of the primary electric power). Additional system design features (such as compartmentalization with independent subsystems) limit the potential for cross-contamination within the WHB. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Handling Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits. The system design, operations, and maintenance activities incorporate ALARA (as low as is reasonably achievable) principles to maintain personnel radiation doses to all occupational workers below regulatory limits and as low as is reasonably achievable. The Waste Handling Building Ventilation System interfaces with the Waste Handling Building System by being located within the WHB and by maintaining specific pressures, temperatures, and humidity within the building. The system also depends on the WHB for water supply. The system interfaces with the Site Radiological Monitoring System for continuous monitoring of the exhaust air; the Waste Handling Building Fire Protection System for detection of fire and smoke; the Waste Handling Building Electrical System for normal, emergency, and standby power; and the Monitored Geologic Repository Operations Monitoring and Control System for monitoring and control of the system.

  4. WASTE TREATMENT BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    P.A. Kumar

    2000-06-22

    The Waste Treatment Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Treatment Building (WTB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for personnel comfort and equipment operation, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WTB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement area ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination with the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WTB. The Waste Treatment Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits, The system design, operations, and maintenance activities incorporate ALARA (as low as is reasonably achievable) principles to maintain personnel radiation doses to all occupational workers below regulatory limits and as low as is reasonably achievable. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Treatment Building Ventilation System interfaces with the Waste Treatment Building System by being located in the WTB, and by maintaining specific pressure, temperature, and humidity environments within the building. The system also depends on the WTB for normal electric power supply and the required supply of water for heating, cooling, and humidification. Interface with the Waste Treatment Building System includes the WTB fire protection subsystem for detection of fire and smoke. The Waste Treatment Building Ventilation System interfaces with the Site Radiological Monitoring System for continuous monitoring of the exhaust air and key areas within the WTB, the Monitored Geologic Repository Operations Monitoring and Control System for monitoring and control of system operations, and the Site Generated Radiological Waste Handling System and Site Generated Hazardous, Non-Hazardous & Sanitary Waste Disposal System for routing of pretreated toxic, corrosive, and radiologically contaminated effluent from process equipment to the HEPA filter exhaust ductwork and air-cleaning unit.

  5. A miniature mechanical ventilator for newborn mice.

    PubMed

    Kolandaivelu, K; Poon, C S

    1998-02-01

    Transgenic/knockout mice with pre-defined mutations have become increasingly popular in biomedical research as models of human diseases. In some instances, the resulting mutation may cause cardiorespiratory distress in the neonatal or adult animals and may necessitate resuscitation. Here we describe the design and testing of a miniature and versatile ventilator that can deliver varying ventilatory support modes, including conventional mechanical ventilation and high-frequency ventilation, to animals as small as the newborn mouse. With a double-piston body chamber design, the device circumvents the problem of air leakage and obviates the need for invasive procedures such as endotracheal intubation, which are particularly important in ventilating small animals. Preliminary tests on newborn mice as early as postnatal day O demonstrated satisfactory restoration of pulmonary ventilation and the prevention of respiratory failure in mutant mice that are prone to respiratory depression. This device may prove useful in the postnatal management of transgenic/knockout mice with genetically inflicted respiratory disorders. PMID:9475887

  6. Tunnel Ventilation Control Using Reinforcement Learning Methodology

    NASA Astrophysics Data System (ADS)

    Chu, Baeksuk; Kim, Dongnam; Hong, Daehie; Park, Jooyoung; Chung, Jin Taek; Kim, Tae-Hyung

    The main purpose of tunnel ventilation system is to maintain CO pollutant concentration and VI (visibility index) under an adequate level to provide drivers with comfortable and safe driving environment. Moreover, it is necessary to minimize power consumption used to operate ventilation system. To achieve the objectives, the control algorithm used in this research is reinforcement learning (RL) method. RL is a goal-directed learning of a mapping from situations to actions without relying on exemplary supervision or complete models of the environment. The goal of RL is to maximize a reward which is an evaluative feedback from the environment. In the process of constructing the reward of the tunnel ventilation system, two objectives listed above are included, that is, maintaining an adequate level of pollutants and minimizing power consumption. RL algorithm based on actor-critic architecture and gradient-following algorithm is adopted to the tunnel ventilation system. The simulations results performed with real data collected from existing tunnel ventilation system and real experimental verification are provided in this paper. It is confirmed that with the suggested controller, the pollutant level inside the tunnel was well maintained under allowable limit and the performance of energy consumption was improved compared to conventional control scheme.

  7. Computational fluid dynamics in ventilation: Practical approach

    NASA Astrophysics Data System (ADS)

    Fontaine, J. R.

    The potential of computation fluid dynamics (CFD) for conceiving ventilation systems is shown through the simulation of five practical cases. The following examples are considered: capture of pollutants on a surface treating tank equipped with a unilateral suction slot in the presence of a disturbing air draft opposed to suction; dispersion of solid aerosols inside fume cupboards; performances comparison of two general ventilation systems in a silkscreen printing workshop; ventilation of a large open painting area; and oil fog removal inside a mechanical engineering workshop. Whereas the two first problems are analyzed through two dimensional numerical simulations, the three other cases require three dimensional modeling. For the surface treating tank case, numerical results are compared to laboratory experiment data. All simulations are carried out using EOL, a CFD software specially devised to deal with air quality problems in industrial ventilated premises. It contains many analysis tools to interpret the results in terms familiar to the industrial hygienist. Much experimental work has been engaged to validate the predictions of EOL for ventilation flows.

  8. Blood pressure control and antihypertensive pharmacotherapy patterns in a hypertensive population of Eastern Central Region of Portugal

    PubMed Central

    2010-01-01

    Background Interventions to improve blood pressure control in hypertension have had limited success in clinical practice despite evidence of cardiovascular disease prevention in randomised controlled trials. The objectives of this study were to evaluate blood pressure control and antihypertensive pharmacotherapy patterns in a population of Eastern Central Region of Portugal, attending a hospital outpatient clinic (ambulatory setting) for routine follow-up. Methods Medical data of all patients that attended at least two medical appointments of hypertension/dyslipidemia in a university hospital over a one and a half year period (from January 2008 to June 2009) were retrospectively analysed. Demographic variables, clinical data and blood pressure values of hypertensive patients included in the study, as well as prescribing metrics were examined on a descriptive basis and expressed as the mean ± SD, frequency and percentages. Student's test and Mann-Whitney rank sum test were used to compare continuous variables and χ2 test and Fisher exact probability test were used to test for differences between categorical variables. Results In all, 37% of hypertensive patients (n = 76) had their blood pressure controlled according to international guidelines. About 45.5% of patients with a target blood pressure <140/90 mmHg (n = 156) were controlled, whereas in patients with diabetes or chronic kidney disease (n = 49) the corresponding figure was only 10.2% (P < 0.001). Among patients initiating hypertension/dyslipidemia consultation within the study period 32.1% had stage 2 hypertension in the first appointment, but this figure decreased to 3.6% in the last consultation (P = 0.012). Thiazide-type diuretics were the most prescribed antihypertensive drugs (67%) followed by angiotensin receptor blockers (60%) and beta-blockers (43%). About 95.9% patients with comorbid diabetes were treated with an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Conclusions Clinically important blood pressure decreases can be achieved soon after hypertension medical appointment initiation. However, many hypertensive patients prescribed with antihypertensive therapy fail to achieve blood pressure control in clinical practice, this control being worse among patients with diabetes or chronic kidney disease. As pharmacotherapy patterns seem to coincide with international guidelines, further research is needed to identify the causes of poor blood pressure control. PMID:21192829

  9. Engineering work plan and design basis for 241-SY ventilation improvements

    SciTech Connect

    Andersen, J.A.

    1997-05-19

    There are three tanks in the 241-SY tank farm. Tank 241-SY101 and 241-SY-103 are flammable gas watch list tanks. Tank 241-SY-102 is included in the ventilation improvement process in an effort to further control air flow in the tank farm. This tank farm has only one outlet ventilation port for all three tanks. Flammable gas is released (may be steady and/or periodic) from the waste in the primary tank vapor space. The gas is removed from the tank by an active ventilation system. However, maintaining consistent measurable flow through the tank can be problematic due to the poor control capabilities of existing equipment. Low flow through the tank could allow flammable gas to build up in the tank and possibly exceed the lower flammability limit (LFL), prevent the most rapid removal of flammable gas from the tank after a sudden gas release, and/or cause high vacuum alarms to sound. Using the inlet and outlet down stream butterfly valves performs the current method of controlling flow in tank farm 241-SY. A filter station is installed on the inlet of each tank, but controlling air flow with its 12 inch butterfly valve is difficult. There is also in-leakage through pump and valve pits. Butterfly valves on the downstream side of each tank could also be used to control air flow. However, their large size and the relatively low air velocity make this control method also ineffective. The proposed method of optimizing tank air flow and pressure control capability is to install an air flow controller on the inlet of each existing filter station in SY farm, and seal as best as practical all other air leakage paths. Such air flow controllers have been installed on 241-AN and 241-AW tanks (see drawing H-2-85647).

  10. MODELING VENTILATION SYSTEM RESPONSE TO FIRE

    SciTech Connect

    Coutts, D

    2007-04-17

    Fires in facilities containing nuclear material have the potential to transport radioactive contamination throughout buildings and may lead to widespread downwind dispersal threatening both worker and public safety. Development and implementation of control strategies capable of providing adequate protection from fire requires realistic characterization of ventilation system response which, in turn, depends on an understanding of fire development timing and suppression system response. This paper discusses work in which published HEPA filter data was combined with CFAST fire modeling predictions to evaluate protective control strategies for a hypothetical DOE non-reactor nuclear facility. The purpose of this effort was to evaluate when safety significant active ventilation coupled with safety class passive ventilation might be a viable control strategy.

  11. Pulmonary rehabilitation for mechanically ventilated patients.

    PubMed

    Jackson, N C

    1991-12-01

    Pulmonary rehabilitation for the mechanically ventilated patient is a complex process requiring the teamwork of many disciplines. The physician, pulmonary CNS, respiratory therapist, physical therapist, occupational therapist, dietician, speech pathologist, social worker, and chaplain all work together in a coordinated effort. Daily assessment of patient changes and tolerance to therapy is necessary to progress the patient to a relatively independent state. When communication among the team members is effective, few problems go unnoticed. The primary goal of pulmonary rehabilitation is to return patients to their highest functional capacity to enhance their independence and personal ego strength, whether on or off a ventilator, part or all of the time. If chronic mechanical ventilation is the reality, pulmonary rehabilitation must promote a quality lifestyle of independence and autonomy. PMID:1777195

  12. Building ventilation and indoor air quality

    SciTech Connect

    Hollowell, C.D.; Berk, J.V.; Boegel, M.L.; Miksch, R.R.; Nazaroff, W.W.; Traynor, G.W.

    1980-01-01

    Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced infiltration and ventilation in buildings may significantly increase exposure to indoor contaminants and perhaps have adverse effects on occupant health and comfort. Four indoor air contaminants - carbon monoxide and nitrogen dioxide from gas appliances; formaldehyde from particleboard, plywood, urea-formaldehyde foam insulation, and gas appliances; and radon from building materials, soil, and ground water - are currently receiving considerable attention in the context of potential health risks associated with reduced infiltration and ventilation rates. These air contaminants in conventional and energy efficient buildings were measured and analyzed with a view to assessing their potential health risks and various control strategies capable of lowering pollutant concentrations. Preliminary findings suggest that further intensive studies are needed in order to develop criteria for maintaining acceptable indoor air quality without compromising energy efficiency.

  13. Flow measurement in mechanical ventilation: a review.

    PubMed

    Schena, Emiliano; Massaroni, Carlo; Saccomandi, Paola; Cecchini, Stefano

    2015-03-01

    Accurate monitoring of flow rate and volume exchanges is essential to minimize ventilator-induced lung injury. Mechanical ventilators employ flowmeters to estimate the amount of gases delivered to patients and use the flow signal as a feedback to adjust the desired amount of gas to be delivered. Since flowmeters play a crucial role in this field, they are required to fulfill strict criteria in terms of dynamic and static characteristics. Therefore, mechanical ventilators are equipped with only the following kinds of flowmeters: linear pneumotachographs, fixed and variable orifice meters, hot wire anemometers, and ultrasonic flowmeters. This paper provides an overview of these sensors. Their working principles are described together with their relevant advantages and disadvantages. Furthermore, the most promising emerging approaches for flowmeters design (i.e., fiber optic technology and three dimensional micro-fabrication) are briefly reviewed showing their potential for this application. PMID:25659299

  14. Nitrogen-13 and xenon-133 ventilation studies

    SciTech Connect

    van der Mark, T.W.; Rookmaker, A.E.C.; Kiers, A.; Peset, R.; Vaalburg, W.; Paans, A.M.J.; Woldring, M.G.

    1984-11-01

    Due to the solubility of xenon-133 in blood and tissues, errors are introduced in the determination of regional pulmonary ventilation. The authors investigated these errors by comparing the results from ventilation measurements with Xe-133 and N-13 in five normal subjects (both at rest and during exercise) and in seven patients after a pneumonectomy. In the normal subjects at rest, the upper lung fields showed no significant difference in the uptake rates of the two gases. In the middle and lower lung fields, however, the uptake rate for Xe-133 was higher than for N-13. During exercise a significant increase of the specific ventilation was found in the upper lung fields for N-13 compared with Xe-133. In the pneumonectomy patients the overall uptake rate for Xe-133 in the intact hemithorax was 25% larger than for N-13.

  15. AutoCAD based mine ventilation analysis

    SciTech Connect

    Sartain, T.; Scheck, D.

    1999-07-01

    MineVent is a mine ventilation analysis system which runs inside AutoCAD and uses the Penn State and other ventilation simulators. Working from AutoCAD as-mined and projected mine maps, the user picks the node locations and connects them with branches that correspond to the airway paths. Where survey data are not available, the system uses formulas to compute resistances. The system prompts the user for necessary parameters but the branch lengths are automatically computed. Powerful editing features reduce the time to modify existing schematics and try alternative ventilation options. The system also includes a survey data reduction module which outputs pressure drops and quantities values to feed the branch resistance calculator. Output includes color coded schematics with pressures and quantities shown. If the fan curve data have been digitized, the fan operating points are shown on the curves. Tabular output is also available.

  16. Thermoregulation and ventilation of termite mounds

    NASA Astrophysics Data System (ADS)

    Korb, Judith

    2003-05-01

    Some of the most sophisticated of all animal-built structures are the mounds of African termites of the subfamily Macrotermitinae, the fungus-growing termites. They have long been studied as fascinating textbook examples of thermoregulation or ventilation of animal buildings. However, little research has been designed to provide critical tests of these paradigms, derived from a very small number of original papers. Here I review results from recent studies on Macrotermes bellicosus that considered the interdependence of ambient temperature, thermoregulation, ventilation and mound architecture, and that question some of the fundamental paradigms of termite mounds. M. bellicosus achieves thermal homeostasis within the mound, but ambient temperature has an influence too. In colonies in comparably cool habitats, mound architecture is adapted to reduce the loss of metabolically produced heat to the environment. While this has no negative consequences in small colonies, it produces a trade-off with gas exchange in large colonies, resulting in suboptimally low nest temperatures and increased CO2 concentrations. Along with the alteration in mound architecture, the gas exchange/ventilation mechanism also changes. While mounds in the thermally appropriate savannah have a very efficient circular ventilation during the day, the ventilation in the cooler forest is a less efficient upward movement of air, with gas exchange restricted by reduced surface exchange area. These results, together with other recent findings, question entrenched ideas such as the thermosiphon-ventilation mechanism or the assumption that mounds function to dissipate internally produced heat. Models trying to explain the proximate mechanisms of mound building, or building elements, are discussed.

  17. Regenerative Blower for EVA Suit Ventilation Fan

    NASA Technical Reports Server (NTRS)

    Paul, Heather; Izenson, Mike; Chen, Weibo

    2008-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at low pressures that simulate a PLSS environment. We obtained head/flow performance curves over a range of operating speeds, identified the maximum efficiency point for the blower, and used these results to specify the design and operating conditions for the ventilation fan. We designed a compact motor that can drive the blower under all anticipated operating requirements and operate with high efficiency during normal operation. We identified materials for the blower that will enhance safety for operation in a lunar environment. We produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSS ventilation subsystem while running at 5400 rpm and consuming only 9 W of electric power and using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power blower can meet the performance requirements for future PLSSs.

  18. Open circuit mouthpiece ventilation: Concise clinical review.

    PubMed

    Garuti, G; Nicolini, A; Grecchi, B; Lusuardi, M; Winck, J C; Bach, J R

    2014-01-01

    In 2013 new "mouthpiece ventilation" modes are being introduced to commercially available portable ventilators. Despite this, there is little knowledge of how to use noninvasive intermittent positive pressure ventilation (NIV) as opposed to bi-level positive airway pressure (PAP) and both have almost exclusively been reported to have been used via nasal or oro-nasal interfaces rather than via a simple mouthpiece. Non-invasive ventilation is often reported as failing because of airway secretion encumbrance, because of hypercapnia due to inadequate bi-level PAP settings, or poor interface tolerance. The latter can be caused by factors such as excessive pressure on the face from poor fit, excessive oral air leak, anxiety, claustrophobia, and patient-ventilator dys-synchrony. Thus, the interface plays a crucial role in tolerance and effectiveness. Interfaces that cover the nose and/or nose and mouth (oro-nasal) are the most commonly used but are more likely to cause skin breakdown and claustrophobia. Most associated drawbacks can be avoided by using mouthpiece NIV. Open-circuit mouthpiece NIV is being used by large populations in some centers for daytime ventilatory support and complements nocturnal NIV via "mask" interfaces for nocturnal ventilatory support. Mouthpiece NIV is also being used for sleep with the mouthpiece fixed in place by a lip-covering flange. Small 15 and 22mm angled mouthpieces and straw-type mouthpieces are the most commonly used. NIV via mouthpiece is being used as an effective alternative to ventilatory support via tracheostomy tube (TMV) and is associated with a reduced risk of pneumonias and other respiratory complications. Its use facilitates "air-stacking" to improve cough, speech, and pulmonary compliance, all of which better maintain quality of life for patients with neuromuscular diseases (NMDs) than the invasive alternatives. Considering these benefits and the new availability of mouthpiece ventilator modes, wider knowledge of this technique is now warranted. This review highlights the indications, techniques, advantages and disadvantages of mouthpiece NIV. PMID:24841239

  19. Dehumidification and cooling loads from ventilation air

    SciTech Connect

    Harriman, L.G. III; Plager, D.; Kosar, D.

    1997-11-01

    The importance of controlling humidity in buildings is cause for concern, in part, because of indoor air quality problems associated with excess moisture in air-conditioning systems. But more universally, the need for ventilation air has forced HVAC equipment (originally optimized for high efficiency in removing sensible heat loads) to remove high moisture loads. To assist cooling equipment and meet the challenge of larger ventilation loads, several technologies have succeeded in commercial buildings. Newer technologies such as subcool/reheat and heat pipe reheat show promise. These increase latent capacity of cooling-based systems by reducing their sensible capacity. Also, desiccant wheels have traditionally provided deeper-drying capacity by using thermal energy in place of electrical power to remove the latent load. Regardless of what mix of technologies is best for a particular application, there is a need for a more effective way of thinking about the cooling loads created by ventilation air. It is clear from the literature that all-too-frequently, HVAC systems do not perform well unless the ventilation air loads have been effectively addressed at the original design stage. This article proposes an engineering shorthand, an annual load index for ventilation air. This index will aid in the complex process of improving the ability of HVAC systems to deal efficiently with the amount of fresh air the industry has deemed useful for maintaining comfort in buildings. Examination of typical behavior of weather shows that latent loads usually exceed sensible loads in ventilation air by at least 3:1 and often as much as 8:1. A designer can use the engineering shorthand indexes presented to quickly assess the importance of this fact for a given system design. To size those components after they are selected, the designer can refer to Chapter 24 of the 1997 ASHRAE Handbook--Fundamentals, which includes separate values for peak moisture and peak temperature.

  20. Efficacy of intermittent ventilation for providing acceptable indoor air quality

    SciTech Connect

    Sherman, M.H.

    2004-10-01

    Ventilation standards and guidelines typically treat ventilation as a constant and specify its value. In many circumstances a designer wishes to use intermittent ventilation, rather than constant ventilation, but there are no easy equivalencies available. This report develops a model of efficacy that allows one to calculate how much intermittent ventilation one needs to get the same indoor air quality as a the continuous value specified. We have found that there is a simple relationship between three dimensionless quantities: the temporal ventilation effectiveness (which we call the efficacy), the nominal turn-over and the under-ventilation fraction. This relationship allows the calculation of intermittent ventilation for a wide variety of parameters and conditions. We can use the relationship to define a critical time that separates the regime in which ventilation variations can be averaged over from the regime in which variable ventilation is of low effectiveness. We have found that ventilation load-shifting, temporary protection against poor outdoor air quality and dynamic ventilation strategies can be quite effective in low-density buildings such as single-family houses or office spaces. The results of this work enable ventilation standards and guidelines to allow this extra flexibility and still provide acceptable indoor air quality.

  1. Alternative ventilation strategies in cardiopulmonary resuscitation.

    PubMed

    Gabrielli, Andrea; Layon, A Joseph; Wenzel, Volker; Dorges, Volker; Idris, Ahamed H

    2002-06-01

    The introduction of the 2000 Guidelines for Cardiopulmonary Resuscitation emphasizes a new, evidence-based approach to the science of ventilation during cardiopulmonary resuscitation (CPR). New laboratory and clinical science underemphasizes the role of ventilation immediately after a dysrhythmic cardiac arrest (arrest primarily resulting from a cardiovascular event, such as ventricular defibrillation or asystole). However, the classic airway patency, breathing, and circulation (ABC) CPR sequence remains a fundamental factor for the immediate survival and neurologic outcome of patients after asphyxial cardiac arrest (cardiac arrest primarily resulting from respiratory arrest). The hidden danger of ventilation of the unprotected airway during cardiac arrest either by mouth-to-mouth or by mask can be minimized by applying ventilation techniques that decrease stomach gas insufflation. This goal can be achieved by decreasing peak inspiratory flow rate, increasing inspiratory time, and decreasing tidal volume to approximately 5 to 7 mL/kg, if oxygen is available. Laboratory and clinical evidence recently supported the important role of alternative airway devices to mask ventilation and endotracheal intubation in the chain of survival. In particular, the laryngeal mask airway and esophageal Combitube proved to be effective alternatives in providing oxygenation and ventilation to the patient in cardiac arrest in the prehospital arena in North America. Prompt recognition of supraglottic obstruction of the airway is fundamental for the management of patients in cardiac arrest when ventilation and oxygenation cannot be provided by conventional methods. "Minimally invasive" cricothyroidotomy devices are now available for the professional health care provider who is not proficient or comfortable with performing an emergency surgical tracheotomy or cricothyroidotomy. Finally, a recent device that affects the relative influence of positive pressure ventilation on the hemodynamics during cardiac arrest has been introduced, the inspiratory impedance threshold valve, with the goal of maximizing coronary and cerebral perfusion while performing CPR. Although the role of this alternative ventilatory methodology in CPR is rapidly being established, we cannot overemphasize the need for proper training to minimize complications and maximize the efficacy of these new devices. PMID:12386498

  2. Prolonged propofol infusion for mechanically ventilated children.

    PubMed

    Sasabuchi, Y; Yasunaga, H; Matsui, H; Lefor, A K; Fushimi, K

    2016-04-01

    We retrospectively analysed 30-day mortality and duration of intubation for 8016 children ventilated for three or more days, sedated with midazolam (n = 7716) or propofol (n = 300). We matched the propensity scores of 263 pairs of children. The propensity-matched 30-day mortality (95% CI) was similar: 17/263 (6.5%) with midazolam vs. 24/263 (9.1%) with propofol, p = 0.26. Weaning from mechanical ventilation of children sedated with midazolam was slower than weaning of children sedated with propofol, subhazard ratio (95% CI) 1.43 (1.18-1.73), p < 0.001. PMID:26874247

  3. Preoperational test report, recirculation ventilation systems

    SciTech Connect

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  4. Intermodule ventilation studies for the Space Station

    NASA Technical Reports Server (NTRS)

    Davis, Roy G.; Reuter, James L.

    1987-01-01

    This paper examines the ability of the Space Station intermodule ventilation system to maintain centralized control of CO2 removal and O2 supply. The resulting concentration gradients that will arise are calculated by assuming steady state, ideal gas, isothermal conditions, and perfect mixing of air within and between the pressurized elements. In order to estimate the degree of mixing actually obtained for a given ventilation scheme, a program has been developed based on a potential flow solution technique. Preliminary results from this study indicate that substantial short circuiting and recirculation air flow patterns could arise if a simple duct and diffuser air exchange method at the docking port interface were employed.

  5. Noninvasive Ventilation for the Emergency Physician.

    PubMed

    Allison, Michael G; Winters, Michael E

    2016-02-01

    Noninvasive ventilation (NIV) improves oxygenation and ventilation, prevents endotracheal intubation, and decreases the mortality rate in select patients with acute respiratory failure. Although NIV is used commonly for acute exacerbations of chronic obstructive pulmonary disease and acute cardiogenic pulmonary edema, there are emerging indications for its use in the emergency department. Emergency physicians must be knowledgeable regarding the indications and contraindications for NIV in emergency department patients with acute respiratory failure as well as the means of initiating it and monitoring patients who are receiving it. PMID:26614241

  6. USE OF NATURAL VENTILATION TO CONTROL RADON IN SINGLE FAMILYDWELLINGS

    EPA Science Inventory

    The paper discusses an examination of a fundamental assumption inradon mitigation work, that natural ventilation is not veryeffective in lowering indoor radon levels in buildings. Themechanism by which ventilation acted to reduce radon levels wasconsidered to be simple dilution; ...

  7. 14 CFR 27.1187 - Ventilation and drainage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Fire Protection § 27.1187 Ventilation... cause an additional fire hazard. ... for ventilation and drainage of flammable fluids. The drainage means must be— (a) Effective...

  8. 14 CFR 27.1187 - Ventilation and drainage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Fire Protection § 27.1187 Ventilation... cause an additional fire hazard. ... for ventilation and drainage of flammable fluids. The drainage means must be— (a) Effective...

  9. Indoor Air Quality: Is Increased Ventilation the Answer?

    ERIC Educational Resources Information Center

    Hansen, Shirley

    1989-01-01

    Explains how indoor air quality is affected by pollutants in the air and also by temperature, humidity, and ventilation. Increased ventilation alone seldom solves the "sick building syndrome." Lists ways to improve indoor air quality and optimize energy efficiency. (MLF)

  10. Ways of improving economy and reliability of mine ventilation

    SciTech Connect

    N.N. Petrov; N.A. Popov

    2004-09-01

    It is established that mine ventilation by main fans operating at maximum capacity results in higher power consumption. The ways are proposed for reduction in the effective power consumption by ventilation and improvement of mining operation safety.

  11. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the purpose of the space. (b) A means must be provided to close off all vents and ventilators. (c... provide adequate ventilation in all ordinary weather conditions. Provided that paragraph (a) of...

  12. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the purpose of the space. (b) A means must be provided to close off all vents and ventilators. (c... provide adequate ventilation in all ordinary weather conditions. Provided that paragraph (a) of...

  13. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the purpose of the space. (b) A means must be provided to close off all vents and ventilators. (c... provide adequate ventilation in all ordinary weather conditions. Provided that paragraph (a) of...

  14. VENTILATION RESEARCH: A REVIEW OF RECENT INDOOR AIR QUALITY LITERATURE

    EPA Science Inventory

    The report gives results of a literature review, conducted to survey and summarize recent and ongoing engineering research into building ventilation, air exchange rate, pollutant distribution and dispersion, and other effects of heating, ventilation, and air-conditioning (HVAC) s...

  15. 13. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING ACROSS HUDSON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING ACROSS HUDSON RIVER IN BACKGROUND, WITH SOUTH WALL OF NEW JERSEY SIDE OF VENTILATION BUILDING IN FOREGROUND - Holland Tunnel, Beneath Hudson River between New York & Jersey City, New York County, NY

  16. 12. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING IN FOREGROUND; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING IN FOREGROUND; NEW JERSEY SIDE, HUDSON RIVEN VENTILATION BUILDING IN BACKGROUND - Holland Tunnel, Beneath Hudson River between New York & Jersey City, New York County, NY

  17. 2. BRICK END ELEVATION WITH X VENTILATORS, REDPAINTED GABLE WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. BRICK END ELEVATION WITH X VENTILATORS, RED-PAINTED GABLE WITH WHITE STARS AND A DOORWAY HOOD. ALSO SHOWS PORTION OF REAR ELEVATION WITH X VENTILATORS - Decorated Red Barn (1852), State Route 100 vicinity, Pottstown, Montgomery County, PA

  18. Post-Polio Health International including International Ventilator Users Network

    MedlinePlus

    ... post-polio.org. Check out International Ventilator Users Network Post-Polio Health International's mission is to enhance ... Polio Health International (PHI) Including International Ventilator Users Network 4207 Lindell Blvd., #110, Saint Louis, MO 63108- ...

  19. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  20. Does Mixing Make Residential Ventilation More Effective?

    SciTech Connect

    Sherman, Max; Walker, Iain

    2010-08-16

    Ventilation dilutes or removes indoor contaminants to reduce occupant exposure. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. The total ventilation rate is the most important factor in determining the exposure of occupants to given sources, but the zone- specific distribution of exhaust and supply air, and the mixing of ventilation air can have significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage through the building envelope, air distribution systems and the location of sources and occupants. This paper reports recent results of investigations to determine the impact that air mixing has on exposures of residential occupants to prototypical contaminants of concern. Evaluations of existing field measurements and simulations reported in the literature are combined with new analyses to provide an integrated overview of the topic. The results show that for extreme cases additional mixing can be a significant factor but for typical homes looking at average exposures mixing is not helpful and can even make exposures worse.

  1. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory §...

  2. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory §...

  3. Teaching Alveolar Ventilation with Simple, Inexpensive Models

    ERIC Educational Resources Information Center

    DiCarlo, Stephen E.

    2008-01-01

    When teaching and learning about alveolar ventilation with our class of 300 first-year medical students, we use four simple, inexpensive "models." The models, which encourage research-oriented learning and help our students to understand complex ideas, are distributed to the students before class. The students anticipate something new every day,…

  4. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is used in this section, it shall... automatic fire dampers are required, they shall be designed to operate at approximately 165 degrees F. for..., automatic fire dampers shall be fitted adjacent to the bulkhead. The duct between the bulkhead and...

  5. Project Design Concept Primary Ventilation System

    SciTech Connect

    MCGREW, D.L.

    2000-10-02

    Tank Farm Restoration and Safe Operation (TFRSO), Project W-3 14 was established to provide upgrades that would improve the reliability and extend the system life of portions of the waste transfer, electrical, ventilation, instrumentation and control systems for the Hanford Site Tank Farms. An assessment of the tank farm system was conducted and the results are documented in system assessment reports. Based on the deficiencies identified in the tank farm system assessment reports, and additional requirements analysis performed in support of the River Protection Project (RPP), an approved scope for the TFRSO effort was developed and documented in the Upgrade Scope Summary Report (USSR), WHC-SD-W314-RPT-003, Rev. 4. The USSR establishes the need for the upgrades and identifies the specific equipment to be addressed by this project. This Project Design Concept (PDC) is in support of the Phase 2 upgrades and provides an overall description of the operations concept for the W-314 Primary Ventilation Systems. Actual specifications, test requirements, and procedures are not included in this PDC. The PDC is a ''living'' document, which will be updated throughout the design development process to provide a progressively more detailed description of the W-314 Primary Ventilation Systems design. The Phase 2 upgrades to the Primary Ventilation Systems shall ensure that the applicable current requirements are met for: Regulatory Compliance; Safety; Mission Requirements; Reliability; and Operational Requirements.

  6. 24 CFR 3285.505 - Crawlspace ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Crawlspace ventilation. 3285.505 Section 3285.505 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT MODEL MANUFACTURED...

  7. Ventilators in ICU: A boon or burden

    PubMed Central

    Mehndiratta, Man Mohan; Nayak, Rajeev; Ali, Sana; Sharma, Ajay; Gulati, Natasha Singh

    2016-01-01

    Background and Aims: Ventilator-associated pneumonia (VAP) is a major challenge in intensive care units (ICUs). This challenge is even more discernible in a neurological setting owing to the predispositions of patients. Data on VAP in the neurology and neurosurgery ICUs (NNICUs) are scanty in developing countries. This study was conducted to find out the occurrence of VAP, its risk factors, microbiological profile, and antibiotic resistance in patients admitted to the NNICU of a tertiary care institute in India. Materials and Methods: Endotracheal aspirate and blood samples were collected from 100 patients admitted to the NNICU. Complete blood count, microscopic examination, culture and sensitivity testing of aspirate were done. Chest x-ray was also performed to aid in the diagnosis of VAP. Results: Incidence rate of VAP was found to be 24%. Acinetobacter baumannii was the most common pathogen (24.3%) isolated from patients with VAP, and all of these isolates were sensitive to meropenem. Duration of mechanical ventilation (P < 0.0001) and associated comorbid illness (P = 0.005) were found to be significantly associated with VAP, and the duration of mechanical ventilation was found to be the only independent risk factor (P < 0.0001). Conclusions: This study highlights the risks and microbiological perspective of ventilator use among neurology patients so that adequate preventive strategies can be adopted on time. PMID:27011632

  8. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  9. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  10. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  11. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  12. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  13. Tunnel ventilation system design and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Properly designed and functioning tunnel ventilation systems in broiler houses are essential for maintaining productivity of broilers in warm weather. Convective heat loss from high air velocity provides cooling which improves performance; however, high air velocities require larger fans and increa...

  14. [Pediatric home ventilation--practical approach].

    PubMed

    Rath-Wacenovsky, Regina

    2015-09-01

    Out-of-hospital ventilation represents only a marginal area of paediatric therapeutic concepts. In Austria, the proportion of children to be supplied with invasive and non-invasive ventilation increases significantly, together with the challenges of caring for their long-term demands. Neuromuscular diseases accounted for almost the sole indication group. Premature and newborn infants with persistent respiratory failures are an increasing group, needing more extensive care due to additional comorbidities. Children with congenital disorder have often been tracheotomised in order to secure their airway, and non-invasive ventilation as a bridge- or long-term therapy gains in importance more and more. Usually, infants with primary or secondary CNS disorders suffer from respiratory complications and eventually from chronic respiratory insufficiencies during adolescence or young adulthood. Here, invasive or non-invasive ventilation can contribute both to a significant stabilisation of health status and also quality of life. Spirit of research, experience, appropriate support structures, and appropriate networking constitute the most relevant quality- and success criteria for home care. PMID:26511038

  15. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS... fresh air equal to at least 10 times the volume of the room each hour....

  16. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS... fresh air equal to at least 10 times the volume of the room each hour....

  17. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS... fresh air equal to at least 10 times the volume of the room each hour....

  18. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS... fresh air equal to at least 10 times the volume of the room each hour....

  19. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS... fresh air equal to at least 10 times the volume of the room each hour....

  20. Anxiety and Agitation in Mechanically Ventilated Patients

    PubMed Central

    Tate, Judith Ann; Dabbs, Annette Devito; Hoffman, Leslie; Milbrandt, Eric; Happ, Mary Beth

    2013-01-01

    During an ethnography conducted in an intensive care unit (ICU), we found that anxiety and agitation occurred frequently, and were important considerations in the care of 30 patients weaning from prolonged mechanical ventilation. We conducted a secondary analysis to (a) describe characteristics of anxiety and agitation experienced by mechanically ventilated patients; (b) explore how clinicians recognize and interpret anxiety and agitation and (c) describe strategies and interventions used to manage anxiety and agitation with mechanically ventilated patients. We constructed the Anxiety-Agitation in Mechanical Ventilation Model to illustrate the multidimensional features of symptom recognition and management. Patients’ ability to interact with the environment served as a basis for identification and management of anxiety or agitation. Clinicians’ attributions about anxiety or agitation and “knowing the patient” contributed to their assessment of patient responses. Clinicians chose strategies to overcome either the stimulus or patient’s appraisal of risk of the stimulus. This article contributes to the body of knowledge about symptom recognition and management in the ICU by providing a comprehensive model to guide future research and practice. PMID:21908706

  1. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Electric motors must be outside the duct and compartment and: (i) Have an explosion-proof motor for a Class... 46 Shipping 4 2014-10-01 2014-10-01 false Ventilation. 111.15-10 Section 111.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC...

  2. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Electric motors must be outside the duct and compartment and: (i) Have an explosion-proof motor for a Class... 46 Shipping 4 2013-10-01 2013-10-01 false Ventilation. 111.15-10 Section 111.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC...

  3. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Electric motors must be outside the duct and compartment and: (i) Have an explosion-proof motor for a Class... 46 Shipping 4 2012-10-01 2012-10-01 false Ventilation. 111.15-10 Section 111.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC...

  4. Modeling particle loss in ventilation ducts

    SciTech Connect

    Sippola, Mark R.; Nazaroff, William W.

    2003-04-01

    Empirical equations were developed and applied to predict losses of 0.01-100 {micro}m airborne particles making a single pass through 120 different ventilation duct runs typical of those found in mid-sized office buildings. For all duct runs, losses were negligible for submicron particles and nearly complete for particles larger than 50 {micro}m. The 50th percentile cut-point diameters were 15 {micro}m in supply runs and 25 {micro}m in return runs. Losses in supply duct runs were higher than in return duct runs, mostly because internal insulation was present in portions of supply duct runs, but absent from return duct runs. Single-pass equations for particle loss in duct runs were combined with models for predicting ventilation system filtration efficiency and particle deposition to indoor surfaces to evaluate the fates of particles of indoor and outdoor origin in an archetypal mechanically ventilated building. Results suggest that duct losses are a minor influence for determining indoor concentrations for most particle sizes. Losses in ducts were of a comparable magnitude to indoor surface losses for most particle sizes. For outdoor air drawn into an unfiltered ventilation system, most particles smaller than 1 {micro}m are exhausted from the building. Large particles deposit within the building, mostly in supply ducts or on indoor surfaces. When filters are present, most particles are either filtered or exhausted. The fates of particles generated indoors follow similar trends as outdoor particles drawn into the building.

  5. [Percutaneous tracheostomy in the ventilated patient].

    PubMed

    Añón, J M; Araujo, J B; Escuela, M P; González-Higueras, E

    2014-04-01

    The medical indications of tracheostomy comprise the alleviation of upper airway obstruction; the prevention of laryngeal and upper airway damage due to prolonged translaryngeal intubation in patients subjected to prolonged mechanical ventilation; and the facilitation of airway access for the removal of secretions. Since 1985, percutaneous tracheostomy (PT) has gained widespread acceptance as a method for creating a surgical airway in patients requiring long-term mechanical ventilation. Since then, several comparative trials of PT and surgical tracheostomy have been conducted, and new techniques for PT have been developed. The use of percutaneous dilatation techniques under bronchoscopic control are now increasingly popular throughout the world. Tracheostomy should be performed as soon as the need for prolonged intubation is identified. However a validated model for the prediction of prolonged mechanical ventilation is not available, and the timing of tracheostomy should be individualized. The present review analyzes the state of the art of PT in mechanically ventilated patients--this being regarded by many as the technique of choice in performing tracheostomy in critically ill patients. PMID:23347906

  6. 14 CFR 29.831 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ventilation. 29.831 Section 29.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... from harmful or hazardous concentrations of gases or vapors. (c) The concentration of carbon...

  7. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ventilation. 25.831 Section 25.831...: (1) Carbon monoxide concentrations in excess of 1 part in 20,000 parts of air are considered hazardous. For test purposes, any acceptable carbon monoxide detection method may be used. (2)...

  8. 14 CFR 27.831 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ventilation. 27.831 Section 27.831... the presence of excessive quantities of fuel fumes and carbon monoxide. (b) The concentration of carbon monoxide may not exceed one part in 20,000 parts of air during forward flight or hovering in...

  9. 14 CFR 29.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ventilation. 29.831 Section 29.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... from harmful or hazardous concentrations of gases or vapors. (c) The concentration of carbon...

  10. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Personnel and Cargo Accommodations § 23.831...

  11. 14 CFR 29.831 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ventilation. 29.831 Section 29.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... from harmful or hazardous concentrations of gases or vapors. (c) The concentration of carbon...

  12. 14 CFR 27.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ventilation. 27.831 Section 27.831... the presence of excessive quantities of fuel fumes and carbon monoxide. (b) The concentration of carbon monoxide may not exceed one part in 20,000 parts of air during forward flight or hovering in...

  13. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ventilation. 25.831 Section 25.831...: (1) Carbon monoxide concentrations in excess of 1 part in 20,000 parts of air are considered hazardous. For test purposes, any acceptable carbon monoxide detection method may be used. (2)...

  14. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Personnel and Cargo Accommodations § 23.831...

  15. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ventilation. 25.831 Section 25.831...: (1) Carbon monoxide concentrations in excess of 1 part in 20,000 parts of air are considered hazardous. For test purposes, any acceptable carbon monoxide detection method may be used. (2)...

  16. A database of PFT ventilation measurements

    SciTech Connect

    D'Ottavio, T.W.; Goodrich, R.W.; Spandau, D.J.; Dietz, R.N.

    1988-08-01

    About five years ago, a method for measuring the ventilation flows of a building was developed at Brookhaven National Laboratory (BNL). This method is based on the use of a family of compounds known as perfluorocarbon tracers or PFTs. Since 1982, BNL has measured ventilation in more than 4000 homes, comprising about 100 separate research projects throughout the world. This measurement set is unique in that it is the only set of ventilation measurements that acknowledge and measure the multizone characteristics of residences. Other large measurement sets assume that a home can be treated as a single well-mixed zone. This report describes the creation of a database of approximately half of the PFT ventilation measurements made by BNL over the last five years. The PFT database is currently available for use on any IBM PC or Apple Macintosh based personal computer system. In addition to its utility in modeling indoor pollutant dispersion, this database may also be useful to those people studying energy conservation, thermal comfort and heating system design in residential buildings. 2 refs.

  17. A Medical Student Workshop in Mechanical Ventilation.

    ERIC Educational Resources Information Center

    And Others; Kushins, Lawrence G.

    1980-01-01

    In order to teach applied respiratory physiology to medical students, the anesthesiology faculty at the University of Florida College of Medicine has designed and implemented a course that includes a laboratory workshop in mechanical ventilation of an animal model that allows students to apply and expand their knowledge. (JMD)

  18. Closed loop control of oxgenation and ventilation.

    PubMed

    Johannigman, Jay; Branson, Richard D; Muskat, Peter; Barnes, Stephen L; Beck, George

    2007-07-01

    Closed loop control of oxygenation and ventilation during mechanical ventilatory support is essential for remote medical care in an austere environment. Closed loop control allows for expert systems to provide the current standard of care in the absence of on-site expertise. Ventilation may be controlled by simple systems incorporating patient height or by advanced systems incorporating measurements of end-tidal carbon dioxide (ETCO2) and pulmonary impedance. Oxygenation may be controlled by adjustments of inspired oxygen concentrations (FIO2) and positive end-expiratory pressure (PEEP) using pulse oximetry (SpO2) as the input. Control of oxygenation can prevent hypoxemia and has the potential to reduce oxygen requirements. A double closed loop system of oxygenation control including control of FIO2 via SpO2 and control of oxygen generation by a portable oxygen generator (POG) based on FIO2 and minute ventilation (VE) promises safety and efficiency. Remote control of ventilation and oxygenation is possible using existing technology. PMID:18372690

  19. Modeling ventilation time in forage tower silos.

    PubMed

    Bahloul, A; Chavez, M; Reggio, M; Roberge, B; Goyer, N

    2012-10-01

    The fermentation process in forage tower silos produces a significant amount of gases, which can easily reach dangerous concentrations and constitute a hazard for silo operators. To maintain a non-toxic environment, silo ventilation is applied. Literature reviews show that the fermentation gases reach high concentrations in the headspace of a silo and flow down the silo from the chute door to the feed room. In this article, a detailed parametric analysis of forced ventilation scenarios built via numerical simulation was performed. The methodology is based on the solution of the Navier-Stokes equations, coupled with transport equations for the gas concentrations. Validation was achieved by comparing the numerical results with experimental data obtained from a scale model silo using the tracer gas testing method for O2 and CO2 concentrations. Good agreement was found between the experimental and numerical results. The set of numerical simulations made it possible to establish a simple analytical model to predict the minimum time required to ventilate a silo to make it safe to enter. This ventilation time takes into account the headspace above the forage, the airflow rate, and the initial concentrations of O2 and CO2. The final analytical model was validated with available results from the literature. PMID:23189513

  20. Teaching Alveolar Ventilation with Simple, Inexpensive Models

    ERIC Educational Resources Information Center

    DiCarlo, Stephen E.

    2008-01-01

    When teaching and learning about alveolar ventilation with our class of 300 first-year medical students, we use four simple, inexpensive "models." The models, which encourage research-oriented learning and help our students to understand complex ideas, are distributed to the students before class. The students anticipate something new every day,