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Tidal model

Gisele de A Padilha, Lucas F B Horta, Lillian Moraes, Cassia L Braga, Milena V Oliveira, Cíntia L Santos, Isalira P Ramos, Marcelo M Morales, Vera Luiza Capelozzi, Regina C S Goldenberg, Marcelo Gama de Abreu, Paolo Pelosi, Pedro L Silva, Patricia R M Rocco
BACKGROUND: In patients with emphysema, invasive mechanical ventilation settings should be adjusted to minimize hyperinflation while reducing respiratory effort and providing adequate gas exchange. We evaluated the impact of pressure-controlled ventilation (PCV) and pressure support ventilation (PSV) on pulmonary and diaphragmatic damage, as well as cardiac function, in experimental emphysema. METHODS: Emphysema was induced by intratracheal instillation of porcine pancreatic elastase in Wistar rats, once weekly for 4 weeks...
December 2016: Intensive Care Medicine Experimental
Thomas Breuer, Nima Hatam, Benjamin Grabiger, Gernot Marx, Bradley J Behnke, Joachim Weis, Ruedger Kopp, Ghislaine Gayan-Ramirez, Norbert Zoremba, Christian S Bruells
Perioperative necessity of deep sedation is inevitably associated with diaphragmatic inactivation. This study investigated 1) the feasibility of a new phrenic nerve stimulation method allowing early diaphragmatic activation even in deep sedation and, 2) metabolic changes within the diaphragm during mechanical ventilation compared to artificial activity. 12 piglets were separated into 2 groups. One group was mechanically ventilated for 12 hrs (CMV) and in the second group both phrenic nerves were stimulated via pacer wires inserted near the phrenic nerves to mimic spontaneous breathing (STIM)...
October 19, 2016: Scientific Reports
Fei Yu, Hui Zeng, Ming Lei, De-Ming Xiao, Wei Li, Hao Yuan, Jian-Jing Lin
This study investigated the effects of SIRT1 gene knock-out on osteoarthritis in mice, and the possible roles of SREBP2 protein and the PI3K/AKT signaling pathway in the effects. Mice were randomly divided into a normal group and a SIRT1 gene knock-out group (6 mice in each group). In these groups, one side of the knee anterior cruciate ligament was traversed, and the ipsilateral medial meniscus was cut to establish an osteoarthritis model of knee joint. The countralateral synovial bursa was cut out, serving as controls...
October 2016: Journal of Huazhong University of Science and Technology. Medical Sciences
Julia Scheiermann, Dennis M Klinman
BACKGROUND: Mechanical ventilation (MV) is commonly used to improve blood oxygenation in critically ill patients and for general anesthesia. Yet the cyclic mechanical stress induced at even moderate ventilation volume settings [tidal volume (Vt) <10 mL/kg] can injure the lungs and induce an inflammatory response. This work explores the effect of treatment with suppressive oligonucleotides (Sup ODN) in a mouse model of ventilator-induced lung injury (VILI). METHODS: Balb/cJ mice were mechanically ventilated for 4 h using clinically relevant Vt and a positive end-expiratory pressure of 3 cmH2O under 2-3% isoflurane anesthesia...
September 2016: Journal of Thoracic Disease
Amy Yuan, Jie Wei, Carl P Gaebler, Hailiang Huang, Devin Olek, Guang Li
PURPOSE: To develop a physical, adaptive motion perturbation model to predict tumor motion using feedback from dynamic measurement of breathing conditions to compensate for breathing irregularities. METHODS AND MATERIALS: A novel respiratory motion perturbation (RMP) model was developed to predict tumor motion variations caused by breathing irregularities. This model contained 2 terms: the initial tumor motion trajectory, measured from 4-dimensional computed tomography (4DCT) images, and motion perturbation, calculated from breathing variations in tidal volume (TV) and breathing pattern (BP)...
September 3, 2016: International Journal of Radiation Oncology, Biology, Physics
Tatiana F Maria, Jan Vanaverbeke, Ann Vanreusel, André M Esteves
In this review, we summarize existing knowledge of the ecology of sandy-beach nematodes, in relation to spatial distribution, food webs, pollution and climate change. We attempt to discuss spatial scale patterns (macro-, meso- and microscale) according to their degree of importance in structuring sandy-beach nematode assemblages. This review will provide a substantial background on current knowledge of sandy-beach nematodes, and can be used as a starting point to delineate further investigations in this field...
October 10, 2016: Anais da Academia Brasileira de Ciências
Vinícius Carvalho Fonseca, Edilson Paes Saraiva, Alex Sandro Campos Maia, Carolina Cardoso Nagib Nascimento, Josinaldo Araújo da Silva, Walter Esfraim Pereira, Edgard Cavalcanti Pimenta Filho, Maria Elivânia Vieira Almeida
The aim of this study was to build a prediction model both sensible and latent heat transfer by respiratory tract for Morada Nova sheep under field conditions in a semiarid tropical environment, using easily measured physiological and environmental parameters. Twelve dry Morada Nova ewes with an average of 3 ± 1.2 years old and average body weight of 32.76 ± 3.72 kg were used in a Latin square design 12 × 12 (12 days of records and 12 schedules). Tidal volume, respiratory rate, expired air temperature, and partial vapor pressure of the expired air were obtained from the respiratory facial mask and using a physiological measurement system...
October 10, 2016: International Journal of Biometeorology
Karline Soetaert, Christian Mohn, Anna Rengstorf, Anthony Grehan, Dick van Oevelen
Cold-water corals (CWCs) form large mounds on the seafloor that are hotspots of biodiversity in the deep sea, but it remains enigmatic how CWCs can thrive in this food-limited environment. Here, we infer from model simulations that the interaction between tidal currents and CWC-formed mounds induces downwelling events of surface water that brings organic matter to 600-m deep CWCs. This positive feedback between CWC growth on carbonate mounds and enhanced food supply is essential for their sustenance in the deep sea and represents an example of ecosystem engineering of unparalleled magnitude...
October 11, 2016: Scientific Reports
Glauco A Westphal, Elisabeth Coll, Rafael L de Souza, Silvana Wagner, Artur Montemezzo, Fernanda Carolina Cani de Souza, Gabriel Torres, Stefan Halla, Tiago C Carnin, Míriam C Machado, Eduardo Berbigier, Fernando Busetto, Ivonei Bittencourt, Karine Gerent, Bruno S de Souza, Manoel Tassinari, Joel de Andrade
BACKGROUND: The disproportion between the large organ demand and the low number of transplantations performed represents a serious public health problem worldwide. Reducing the loss of transplantable organs from deceased potential donors as a function of cardiac arrest (CA) may contribute to an increase in organ donations. Our purpose was to test the hypothesis that a goal-directed protocol to guide the management of deceased donors may reduce the losses of potential brain-dead donors (PBDDs) due to CA...
October 11, 2016: Critical Care: the Official Journal of the Critical Care Forum
Melvin E Stone, Stanley Kalata, Anna Liveris, Zachary Adorno, Shira Yellin, Edward Chao, Srinivas H Reddy, Michael Jones, Carlos Vargas, Sheldon Teperman
BACKGROUND: Critical administration threshold (≥3 units of packed red blood cells/h or CAT+) has been proposed as a new definition for massive transfusion (MT) that includes volume and rate of blood transfusion. CAT+ has been shown to eliminate survivor bias and be a better predictor of mortality than the traditional MT (>10 units/24h). End-tidal CO2 (ET CO2) negatively correlates with lactate and is an early predictor of shock in trauma patients. We conducted a pilot study to test the hypothesis that low ET CO2 on admission predicts CAT+...
July 5, 2016: Injury
Camilla R S Silva, Lívia B Andrade, Danielle A S X Maux, Andreza L Bezerra, Maria C M B Duarte
Objective: To evaluate the effectiveness of prophylactic, non-invasive ventilation (NIV) on respiratory function in seven- to 16-year-old children in the post-operative phase of cardiac surgery. Method: A randomized, controlled trial with 50 children who had undergone cardiac surgery with median sternotomy. After extubation, patients were randomly assigned to one of two groups: control group (n=26), which received instructions regarding posture, early ambulation, and cough stimulation, and CPAP group (continuous positive airway pressure; n=24), which received the same instructions as the control group and CPAP=10 cmH20 twice daily for 30 minutes from the 1st to the 5th post-operative day (POD)...
September 29, 2016: Brazilian Journal of Physical Therapy
Alexander V Grayver, Neesha R Schnepf, Alexey V Kuvshinov, Terence J Sabaka, Chandrasekharan Manoj, Nils Olsen
The tidal flow of electrically conductive oceans through the geomagnetic field results in the generation of secondary magnetic signals, which provide information on the subsurface structure. Data from the new generation of satellites were shown to contain magnetic signals due to tidal flow; however, there are no reports that these signals have been used to infer subsurface structure. We use satellite-detected tidal magnetic fields to image the global electrical structure of the oceanic lithosphere and upper mantle down to a depth of about 250 km...
September 2016: Science Advances
Maria Skytioti, Signe Søvik, Maja Elstad
Intact cerebral blood flow (CBF) is essential for cerebral metabolism and function, whereas hypoperfusion in relation to hypovolemia and hypocapnia can lead to severe cerebral damage. This study was designed to assess internal carotid artery blood flow (ICA-BF) during simulated hypovolemia and noninvasive positive pressure ventilation (PPV) in young healthy humans. Beat-by-beat blood velocity (ICA and aorta) were measured by Doppler ultrasound during normovolemia and simulated hypovolemia (lower body negative pressure), with or without PPV in 15 awake subjects...
October 2016: Physiological Reports
Andrew C Muller, Diana L Muller, Arianna Muller
The nature of emerging patterns concerning water quality stressors and the evolution of hypoxia within sub-estuaries of the Chesapeake Bay has been an important unresolved question among the Chesapeake Bay community. Elucidation of the nature of hypoxia in the tributaries of the Chesapeake Bay has important ramifications to the successful restoration of the Bay, since much of Bay states population lives within the watersheds of the tributaries. Very little to date, is known about the small sub-estuaries of the Chesapeake Bay due to limited resources and the difficulties in resolving both space and time dimensions on scales that are adequate to resolve this question...
September 2016: Heliyon
Stephanie Lovinsky-Desir, Kyung Hwa Jung, Andrew G Rundle, Lori A Hoepner, Joshua B Bautista, Frederica P Perera, Steven N Chillrud, Matthew S Perzanowski, Rachel L Miller
OBJECTIVE: Regular physical activity can improve cardiopulmonary health; however, increased respiratory rates and tidal volumes during activity may increase the effective internal dose of air pollution exposure. Our objective was to investigate the impact of black carbon (BC) measured by personal sampler on the relationship between physical activity and fractional exhaled nitric oxide (FeNO), a marker of airway inflammation. We hypothesized that higher personal BC would attenuate the protective effect of physical activity on airway inflammation...
September 29, 2016: Environmental Research
Rinu K Rana, Rakesh K Patel
BACKGROUND: The involvement of debilitating side effects of allopathic antiasthmatic drugs provides a strong impetus for the development of new herbal therapeutics. Myrica nagi Thunb. (Syn. Kaiphal) of Myricaceae family is a known drug of the Ayurveda system used for the treatment of several diseases including asthma. METHODS: The present study deals with the preparation and phytochemical screening of polar, non-polar and methanolic extracts of Myrica nagi bark followed by the evaluation of their antiasthmatic activity using four different animal experimental models: acetylcholine induced bronchospasm in conscious guinea pigs, acetylcholine induced contraction on isolated guinea pig tracheal chain preparation, compound 48/80 induced mast cell degranulation using rat, and trypsin and egg albumin induced bronchospasm in conscious rat...
September 23, 2016: Anti-inflammatory & Anti-allergy Agents in Medicinal Chemistry
Wei Gao, Ying-Nan Ju
BACKGROUND AND AIMS: Patients with acute respiratory distress syndrome (ARDS) are particularly susceptible to ventilator-induced lung injury (VILI). This study investigated the effect of budesonide on VILI in a rat model of inflammatory ARDS. METHODS: Forty eight rats were randomized into three groups (n = 16 each): sham group (S), endotoxin/ventilation group (LV), endotoxin/ventilation/budesonide group (LVB). Rats in the S group received anesthesia only. Rats in the LV and LVB groups received endotoxin to simulate ARDS and were mechanically ventilated for 4 h (tidal volume 30 mL/kg)...
May 2016: Archives of Medical Research
Isabelle Lajoie, Felipe B Tancredi, Richard D Hoge
The current generation of calibrated MRI methods goes beyond simple localization of task-related responses to allow the mapping of resting-state cerebral metabolic rate of oxygen (CMRO2) in micromolar units and estimation of oxygen extraction fraction (OEF). Prior to the adoption of such techniques in neuroscience research applications, knowledge about the precision and accuracy of absolute estimates of CMRO2 and OEF is crucial and remains unexplored to this day. In this study, we addressed the question of methodological precision by assessing the regional inter-subject variance and intra-subject reproducibility of the BOLD calibration parameter M, OEF, O2 delivery and absolute CMRO2 estimates derived from a state-of-the-art calibrated BOLD technique, the QUantitative O2 (QUO2) approach...
2016: PloS One
Per Persson, Stefan Lundin, Ola Stenqvist
BACKGROUND: We have shown in acute lung injury patients that lung elastance can be determined by a positive end-expiratory pressure (PEEP) step procedure and proposed that this is explained by the spring-out force of the rib cage off-loading the chest wall from the lung at end-expiration. The aim of this study was to investigate the effect of the expanding chest wall on pleural pressure during PEEP inflation by building a model with an elastic recoiling lung and an expanding chest wall complex...
December 2016: Intensive Care Medicine Experimental
Aina G Gómez, Bárbara Ondiviela, María Fernández, José A Juanes
An atlas of susceptibility to pollution of 320 Spanish marinas is provided. Susceptibility is assessed through a simple, fast and low cost empirical method estimating the flushing capacity of marinas. The Complexity Tidal Range Index (CTRI) was selected among eleven empirical methods. The CTRI method was selected by means of statistical analyses because: it contributes to explain the system's variance; it is highly correlated to numerical model results; and, it is sensitive to marinas' location and typology...
September 15, 2016: Marine Pollution Bulletin
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