WorldWideScience

Sample records for cerebral oxygen demand

  1. Cerebral oxygenation after birth

    DEFF Research Database (Denmark)

    Hessel, Trine W; Hyttel-Sorensen, Simon; Greisen, Gorm

    2014-01-01

    AIM: To compare absolute values of regional cerebral tissue oxygenation (cStO2 ) during haemodynamic transition after birth and repeatability during steady state for two commercial near-infrared spectroscopy (NIRS) devices. METHODS: In a prospective observational study, the INVOS 5100C and FORE......: The INVOS and FORE-SIGHT cStO2 estimates showed oxygenation-level-dependent difference during birth transition. The better repeatability of FORE-SIGHT could be due to the lower response to change in saturation....

  2. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    Anthony Richard Bain

    2014-03-01

    Full Text Available Hyperthermia is associated with marked reductions in cerebral blood flow (CBF. Increased distribution of cardiac output to the periphery, increases in alveolar ventilation and resultant hypocapnia each contribute to the fall in CBF during passive hyperthermia; however, their relative contribution remains a point of contention, and probably depends on the experimental condition (e.g. posture and degree of hyperthermia. The hyperthermia-induced hyperventilatory response reduces arterial CO2 pressure (PaCO2 causing cerebral vasoconstriction and subsequent reductions in flow. During supine passive hyperthermia, the majority of recent data indicate that reductions in PaCO2 may be the primary, if not sole, culprit for reduced CBF. On the other hand, during more dynamic conditions (e.g. hemorrhage or orthostatic challenges, an inability to appropriately decrease peripheral vascular conductance presents a condition whereby adequate cerebral perfusion pressure may be compromised secondary to reductions in systemic blood pressure. Although studies have reported maintenance of pre-frontal cortex oxygenation (assessed by near-infrared spectroscopy during exercise and severe heat stress, the influence of cutaneous blood flow is known to contaminate this measure. This review discusses the governing mechanisms associated with changes in CBF and oxygenation during moderate to severe (i.e. 1.0°C to 2.0°C increase in body core temperature levels of hyperthermia. Future research directions are provided.

  3. Monitoring Cerebral Oxygenation in Neonates: An Update

    Science.gov (United States)

    Dix, Laura Marie Louise; van Bel, Frank; Lemmers, Petra Maria Anna

    2017-01-01

    Cerebral oxygenation is not always reflected by systemic arterial oxygenation. Therefore, regional cerebral oxygen saturation (rScO2) monitoring with near-infrared spectroscopy (NIRS) is of added value in neonatal intensive care. rScO2 represents oxygen supply to the brain, while cerebral fractional tissue oxygen extraction, which is the ratio between rScO2 and systemic arterial oxygen saturation, reflects cerebral oxygen utilization. The balance between oxygen supply and utilization provides insight in neonatal cerebral (patho-)physiology. This review highlights the potential and limitations of cerebral oxygenation monitoring with NIRS in the neonatal intensive care unit. PMID:28352624

  4. Effects of Milrinone continuous intravenous infusion on global cerebral oxygenation and cerebral vasospasm after cerebral aneurysm surgical clipping

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ghanem

    2014-01-01

    Conclusions: Milrinone improved significantly the global cerebral oxygenation and reduced the incidence of cerebral vasospasm during the dangerous period of cerebral spasm after cerebral aneurysm clipping.

  5. 通气程度对颅脑损伤患者脑氧供需平衡的影响%Effect of hyperventilation on cerebral oxygen supply-demand balance in patients with traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    程明华; 许映娜

    2005-01-01

    BACKGROUND: Inadequate hyperventilation may trigger cerebrovascular contraction and lead to lowered cerebral perfusion and oxygen supply-demand imbalance.OBJECTIVE: To investigate the influence of hyperventilation on oxygen saturation in the internal jugular vein, difference in oxygen and lactic acid contents between the cerebral arteries and veins in patients with serious traumatic brain injury.DESIGN: Case analysis.SETTING: Department of Anesthesiology, First Hospital Affiliated to Shantou University.PARTICIPANTS: Sixteen patients who received emergency operations in the First Hospital Affiliated to Shantou University between January and July 2002.METHODS: Patients with traumatic brain injury underwent operation under general anesthesia, and the PaCO2 was maintained at 30 mm Hg for 15 minutes by regulating the respiration rate, followed by decrease to 25 mm Hg, maintained for 15 minutes before restoration to 30 mm Hg for 15 minutes. The fractional concentration of inspired oxygen was adjusted to maintain blood PaO2 at around 100-150 mm Hg, and the blood sample was collected from the artery and internal jugular vein 15 minutes after adjustment of PaCO2 for blood gas analysis. The PaO2 was then increased to 200-250 mm Hg by increasing the fractional concentration of inspired oxygen, and the PaCO2 was adjusted from 30 to 25 and then back to 30 mm Hg in the described manner, and the oxygen saturation in the internal jugular vein, difference in oxygen and lactic acid contents between the arteries and the veins were measured.MAIN OUTCOME MEASURES: Influence of blood PaO2 and PaCO2 on oxygen saturation in the internal jugular vein, difference in oxygen and lactic acid contents between the arteries and the veins.RESULTS: Sixteen patients met the diagnostic criteria and completed data collection. The arterial PaCO2 decreased from 30 to 25 mm Hg when arterial blood oxygen pressure increased from 100-150 to 200-250 mm Hg, which leads to obvious decrease of oxygen saturation

  6. Cerebral Tissue Oxygenation during Immediate Neonatal Transition and Resuscitation

    Science.gov (United States)

    Pichler, Gerhard; Schmölzer, Georg M.; Urlesberger, Berndt

    2017-01-01

    This article provides a review of cerebral tissue oxygenation during immediate transition after birth in human neonates. Recommended routine monitoring, especially if resuscitation is needed, during this period includes arterial oxygen saturation and heart rate measured by pulse oximetry and electrocardiogram. However, there is increasing interest to monitor in addition with near-infrared spectroscopy (NIRS) the oxygenation of the brain. There is a different pattern of increase between cerebral tissue oxygenation and arterial oxygen saturation during the immediate transition, with cerebral tissue oxygenation reaching a plateau faster than arterial oxygen saturation. Differences can be explained, since cerebral tissue oxygenation is not only affected by arterial oxygen saturation but also by cerebral blood flow, hemoglobin content, and cerebral oxygen consumption. Normal values have already been established for different devices, gestational ages, and modes of delivery in neonates without any medical support. Cerebral hypoxia during immediate transition might cause brain damage. In preterm neonates with cerebral hemorrhage evolving in the first week after birth, the cerebral tissue oxygenation is already lower in the first minutes after birth compared to preterm neonates without cerebral hemorrhage. Using cerebral NIRS in combination with intervention guidelines has been shown to reduce the burden of cerebral hypoxia in preterm neonates. Cerebral tissue oxygenation during immediate transition seems to have an impact on outcome, whereby NIRS monitoring is feasible and has the advantage of continuous, non-invasive recording. The impact of NIRS monitoring and interventions on short- and long-term outcomes still need to be evaluated. PMID:28280719

  7. Transcranial laser stimulation improves human cerebral oxygenation

    OpenAIRE

    2016-01-01

    Background and Objective Transcranial laser stimulation of the brain with near‐infrared light is a novel form of non‐invasive photobiomodulation or low‐level laser therapy (LLLT) that has shown therapeutic potential in a variety of neurological and psychological conditions. Understanding of its neurophysiological effects is essential for mechanistic study and treatment evaluation. This study investigated how transcranial laser stimulation influences cerebral hemodynamics and oxygenation in th...

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

    Directory of Open Access Journals (Sweden)

    A. I. Lenkin

    2012-01-01

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

  9. Inadequate cerebral oxygen delivery and central fatigue during strenuous exercise

    DEFF Research Database (Denmark)

    Nybo, Lars; Rasmussen, Peter

    2007-01-01

    Under resting conditions, the brain is protected against hypoxia because cerebral blood flow increases when the arterial oxygen tension becomes low. However, during strenuous exercise, hyperventilation lowers the arterial carbon dioxide tension and blunts the increase in cerebral blood flow, which...... can lead to an inadequate oxygen delivery to the brain and contribute to the development of fatigue....

  10. Increased intrathoracic pressure affects cerebral oxygenation following cardiac surgery

    DEFF Research Database (Denmark)

    Pedersen, Lars M; Nielsen, Jonas; Østergaard, Morten

    2012-01-01

    Cerebral oximetry reflects circulatory stability during surgery. We evaluated whether frontal lobe oxygenation is influenced by a transient increase in intrathoracic pressure as induced by a lung recruitment manoeuvre.......Cerebral oximetry reflects circulatory stability during surgery. We evaluated whether frontal lobe oxygenation is influenced by a transient increase in intrathoracic pressure as induced by a lung recruitment manoeuvre....

  11. Optoacoustic mapping of cerebral blood oxygenation in humans

    Science.gov (United States)

    Petrov, Yuriy; Prough, Donald S.; Petrov, Irene Y.; Richardson, C. Joan; Fonseca, Rafael A.; Robertson, Claudia S.; Esenaliev, Rinat O.

    2017-03-01

    Noninvasive, transcranial mapping, monitoring, and imaging are highly important for detection and management of cerebral abnormalities and neuroscience research. Mapping, imaging, and monitoring of cerebral blood oxygenation are necessary for diagnostics and management of patients with traumatic brain injury, stroke, and other neurological conditions. We proposed to use optoacoustic technology for noninvasive, transcranial monitoring and imaging. In this work, we developed optoacoustic systems for mapping of cerebral blood oxygenation in humans and tested them in adults and neonates. The systems provide noninvasive, transcranial optoacoustic measurements in the transmission (forward) and reflection (backward) modes in the near infrared spectral range. Novel, ultra-sensitive probes were built for detection of optoacoustic signals and measurement of blood oxygenation in neonates and adults. Cerebral oxygenation was measured at different lateral sites from the superior sagittal sinus (SSS), a large central cerebral vein, located immediately beneath the midline of the human skull. In neonates, cerebral oxygenation was measured through open anterior and posterior fontanelles. Optoacoustic signal detection at different locations allowed for mapping of cerebral blood oxygenation. Our future studies will be focused on 3D mapping of cerebral blood oxygenation.

  12. Lipopolysaccharide infusion enhances dynamic cerebral autoregulation without affecting cerebral oxygen vasoreactivity in healthy volunteers

    DEFF Research Database (Denmark)

    Berg, Ronan Mg; Plovsing, Ronni R; Evans, Kevin A;

    2013-01-01

    Sepsis may be associated with disturbances in cerebral oxygen transport and cerebral haemodynamic function, thus rendering the brain particularly susceptible to hypoxia. The purpose of this study was to assess the impact of isocapnic hypoxia and hyperoxia on dynamic cerebral autoregulation...... in a human-experimental model of the systemic inflammatory response during the early stages of sepsis....

  13. 七氟醚-瑞芬太尼麻醉对缺血型烟雾病脑血管重建术患者脑氧供需平衡的影响%Effects of sevoflurane-remifentanil anesthesia on the balance between cerebral oxygen supply and demand during cerebral revascularization for ischemic moyamoya disease

    Institute of Scientific and Technical Information of China (English)

    梁发; 崔伟华; 何颖; 焦希平; 王嵘; 张东; 韩如泉

    2013-01-01

    目的 评价七氟醚-瑞芬太尼麻醉对缺血型烟雾病脑血管重建术患者脑氧供需平衡的影响.方法 择期行颞浅动脉-大脑中动脉分支吻合术的缺血型烟雾病患者40例,性别不限,年龄19~ 59岁,BMI 19~ 25 kg/m2,ASA分级Ⅰ或Ⅱ级,Suzuki分期≥3.采用随机数字表法,将患者随机分为2组(n=20):异丙酚-瑞芬太尼组(PR组)和七氟醚-瑞芬太尼组(SR组).麻醉诱导:靶控输注异丙酚,血浆靶浓度5 μg/ml,静脉注射芬太尼3 μg/kg和罗库溴铵0.6 mg/kg.气管插管后行机械通气,麻醉维持:SR组吸入七氟醚(呼气末浓度1.0% ~ 1.7%),PR组TCI异丙酚,血浆靶浓度3~4 μg/ml,2组均TCI瑞芬太尼,血浆靶浓度3.5 ng/ml,维持BIS值40 ~ 60,间断静脉注射罗库溴铵0.3 mg/kg.分别于麻醉诱导前(T0)、血管阻断前10 min (T1)、血管阻断后10 min (T2)、血管吻合-开放后10 min (T3)时记录局部脑氧饱和度(rSO2).结果 与T0时比较,PR组T3时术侧rSO2升高,SR组T1-3时术侧和非术侧rSO2升高(P<0.05或0.01);与PR组比较,SR组T1时术侧rSO2升高(P<0.05),非术侧rSO2差异无统计学意义(P>0.05).结论 对于缺血型烟雾病脑血管重建术患者,七氟醚复合瑞芬太尼麻醉可维持良好的脑氧供需平衡状态,且与异丙酚复合瑞芬太尼麻醉的效果相似.%Objective To evaluate the effects of sevoflurane-remifentanil anesthesia on the balance between cerebral oxygen supply and demand during cerebral revascularization for ischemic moyamoya disease by monitoring regional cerebral O2 saturation (rSO2) with near infrared spectroscopy.Methods Forty patients of both sexes aged 19-59 yr with a body mass index of 19-25 kg/m2 undergoing superficial temporal artery-middle cerebral artery anastomosis were randomly allocated into 2 groups (n =20 each):propofol-remifentanil group (group PR) and sevoflurane-remifentanil group (group SR).Radial artery was cannulated for direct BP monitoring and blood sampling

  14. Acetazolamide improves cerebral oxygenation during exercise at high altitude

    NARCIS (Netherlands)

    Vuyk, J.; Bos, J. van den; Terhell, K.; Bos, R. de; Vletter, A.; Valk, P.; Beuzekom, M. van; Kleef, J. van; Dahan, A.

    2006-01-01

    Acute mountain sickness is thought to be triggered by cerebral hypoxemia and be prevented by acetazolamide (Actz). The effect of Actz on cerebral oxygenation at altitude remains unknown. In 16 members of the 2005 Dutch Cho Oyu (8201 m, Tibet) expedition, the influence of Actz and exercise (750 mg PO

  15. Cerebral aspects of neonatal extracorporeal membrane oxygenation: a review.

    NARCIS (Netherlands)

    Mol, A.C. de; Liem, K.D.; Heijst, A.F.J. van

    2013-01-01

    Background: Neonatal extracorporeal membrane oxygenation (ECMO) is a lifesaving therapeutic approach in newborns suffering from severe, but potentially reversible, respiratory insufficiency, mostly complicated by neonatal persistent pulmonary hypertension. However, cerebral damage, intracerebral hem

  16. Cerebral oxygen delivery and consumption during evoked neural activity

    Directory of Open Access Journals (Sweden)

    Alberto L Vazquez

    2010-06-01

    Full Text Available Increases in neural activity evoke increases in the delivery and consumption of oxygen. Beyond observations of cerebral tissue and blood oxygen, the role and properties of cerebral oxygen delivery and consumption during changes in brain function are not well understood. This work overviews the current knowledge of functional oxygen delivery and consumption and introduces recent and preliminary findings to explore the mechanisms by which oxygen is delivered to tissue as well as the temporal dynamics of oxygen metabolism. Vascular oxygen tension measurements have shown that a relatively large amount of oxygen exits pial arterioles prior to capillaries. Additionally, increases in cerebral blood flow (CBF induced by evoked neural activation are accompanied by arterial vasodilation and also by increases in arteriolar oxygenation. This increase contributes not only to the down-stream delivery of oxygen to tissue, but also to delivery of additional oxygen to extra-vascular spaces surrounding the arterioles. On the other hand, the changes in tissue oxygen tension due to functional increases in oxygen consumption have been investigated using a method to suppress the evoked CBF response. The functional decreases in tissue oxygen tension induced by increases in oxygen consumption are slow to evoked changes in CBF under control conditions. Preliminary findings obtained using flavoprotein autofluorescence imaging suggest cellular oxidative metabolism changes at a faster rate than the average changes in tissue oxygen. These issues are important in the determination of the dynamic changes in tissue oxygen metabolism from hemoglobin-based imaging techniques such as blood oxygenation-level dependent functional magnetic resonance imaging (fMRI.

  17. Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S

    1991-01-01

    We measured cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during light sleep (stage 2) in 8 young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness and light sleep as verified by standard...

  18. Prenatal tobacco exposure influences cerebral oxygenation in preterm infants

    NARCIS (Netherlands)

    Verhagen, Elise A.; ter Horst, Hendrik J.; Kooi, Elisabeth M. W.; Keating, Paul; van den Berg, Paul P.; Bos, Arend F.

    2011-01-01

    Aim: Our aim was to determine the influence of prenatal tobacco exposure on regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) in preterm infants. We hypothesized that as a result of vasoconstriction caused by prenatal tobacco exposure r(c)SO(2) wou

  19. Cerebral blood oxygenation measurements in neonates with optoacoustic technique

    Science.gov (United States)

    Herrmann, Stephen; Petrov, Irene Y.; Petrov, Yuriy; Richardson, C. Joan; Fonseca, Rafael A.; Prough, Donald S.; Esenaliev, Rinat O.

    2017-03-01

    Cerebral hypoxia is a major contributor to neonatal/infant mortality and morbidity including severe neurological complications such as mental retardation, cerebral palsy, motor impairment, and epilepsy. Currently, no technology is capable of accurate monitoring of neonatal cerebral oxygenation. We proposed to use optoacoustics for this application by probing the superior sagittal sinus (SSS), a large central cerebral vein. We developed and built a multi-wavelength, optical parametric oscillator (OPO) and laser diode optoacoustic systems for measurement of SSS blood oxygenation in the reflection mode through open anterior or posterior fontanelles and in the transmission mode through the skull in the occipital area. In this paper we present results of initial tests of the laser diode system for neonatal cerebral oxygenation measurements. First, the system was tested in phantoms simulating neonatal SSS. Then, using the data obtained in the phantoms, we optimized the system's hardware and software and tested it in neonates admitted in the Neonatal Intensive Care Unit. The laser diode system was capable of detecting SSS signals in the reflection mode through the open anterior and posterior fontanelles as well as in the transmission mode through the skull with high signal-to-noise ratio. Using the signals measured at different wavelengths and algorithms developed for oxygenation measurements, the laser diode system provided real-time, continuous oxygenation monitoring with high precision at all these locations.

  20. Modelling Dissolved Oxygen/Sediment Oxygen Demand under Ice in a Shallow Eutrophic Prairie Reservoir

    Directory of Open Access Journals (Sweden)

    Julie A. Terry

    2017-02-01

    Full Text Available Dissolved oxygen is an influential factor of aquatic ecosystem health. Future predictions of oxygen deficits are paramount for maintaining water quality. Oxygen demands depend greatly on a waterbody’s attributes. A large sediment–water interface relative to volume means sediment oxygen demand has greater influence in shallow systems. In shallow, ice-covered waterbodies the potential for winter anoxia is high. Water quality models offer two options for modelling sediment oxygen demand: a zero-order constant rate, or a sediment diagenesis model. The constant rate is unrepresentative of a real system, yet a diagenesis model is difficult to parameterise and calibrate without data. We use the water quality model CE-QUAL-W2 to increase the complexity of a zero-order sediment compartment with limited data. We model summer and winter conditions individually to capture decay rates under-ice. Using a semi-automated calibration method, we find an annual pattern in sediment oxygen demand that follows the trend of chlorophyll-a concentrations in a shallow, eutrophic Prairie reservoir. We use chlorophyll-a as a proxy for estimation of summer oxygen demand and winter decay. We show that winter sediment oxygen demand is dependent on the previous summer’s maximum chlorophyll-a concentrations.

  1. Cutaneous vasoconstriction affects near-infrared spectroscopy determined cerebral oxygen saturation during administration of norepinephrine

    DEFF Research Database (Denmark)

    Sørensen, Niels Henrik Breiner; Secher, Niels H; Siebenmann, Christoph

    2012-01-01

    Perioperative optimization of spatially resolved near-infrared spectroscopy determined cerebral frontal lobe oxygenation (scO2) may reduce postoperative morbidity. Norepinephrine is routinely administered to maintain cerebral perfusion pressure and, thereby, cerebral blood flow, but norepinephrine...

  2. Correlating Biochemical and Chemical Oxygen Demand of Effluents

    African Journals Online (AJOL)

    F. K. Attiogbe1, Mary Glover-Amengor2 and K. T. Nyadziehe3

    oxygen demand (COD) of effluents from selected industries in the Kumasi Metropolis to ... comprehensiveness of the approach to solve the problem of wastewater disposal. .... GGL where higher BOD5 values were registered when spent yeast was .... Wastewater Engineering: Treatment, disposal and reuse, 3rd edn.

  3. Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S

    1991-01-01

    We measured cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during light sleep (stage 2) in 8 young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness and light sleep as verified by standard...... polysomnography. Unlike our previous study in man showing a highly significant 25% decrease in CMRO2 during deep sleep (stage 3-4) we found a modest but statistically significant decrease of 5% in CMRO2 during stage 2 sleep. Deep and light sleep are both characterized by an almost complete lack of mental activity....... They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness rather than...

  4. Growth restriction and gender influence cerebral oxygenation in preterm neonates

    NARCIS (Netherlands)

    Cohen, Emily; Baerts, Willem; Alderliesten, Thomas; Derks, Jan; Lemmers, Petra; van Bel, Frank

    2016-01-01

    OBJECTIVE: To investigate the effect of fetal growth restriction and gender on cerebral oxygenation in preterm neonates during the first 3 days of life. DESIGN: Case-control study. SETTING: Neonatal Intensive Care Unit of the Wilhelmina Children's Hospital, The Netherlands. PATIENTS: 68 (41 males)

  5. Cerebral oxygen metabolism in patients with early Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, Per; Cumming, Paul; Østergaard, Karen;

    2012-01-01

    AIM: Decreased activity of the mitochondrial electron transport chain (ETC) has been implicated in the pathogenesis of Parkinson's disease (PD). This model would most likely predict a decrease in the rate of cerebral oxygen consumption (CMRO(2)). To test this hypothesis, we compared CMRO(2...

  6. Sediment oxygen demand in eastern Kansas streams, 2014 and 2015

    Science.gov (United States)

    Foster, Guy M.; King, Lindsey R.; Graham, Jennifer L.

    2016-08-29

    Dissolved oxygen concentrations in streams are affected by physical, chemical, and biological factors in the water column and streambed, and are an important factor for the survival of aquatic organisms. Sediment oxygen demand (SOD) rates in Kansas streams are not well understood. During 2014 and 2015, the U.S. Geological Survey, in cooperation with the Kansas Department of Health and Environment, measured SOD at eight stream sites in eastern Kansas to quantify SOD rates and variability with respect to season, land use, and bottom-sediment characteristics. Sediment oxygen demand rates (SODT) ranged from 0.01 to 3.15 grams per square meter per day at the ambient temperature of the measurements. The summer mean SOD rate was 3.0-times larger than the late fall mean rate, likely because of increased biological activity at warm water temperatures. Given the substantial amount of variability in SOD rates possible within sites, heterogeneity of substrate type is an important consideration when designing SOD studies and interpreting the results. Sediment oxygen demand in eastern Kansas streams was correlated with land use and streambed-sediment characteristics, though the strength of relations varied seasonally. The small number of study sites precluded a more detailed analysis. The effect of basin land use and streambed sediment characteristics on SOD is currently (2016) not well understood, and there may be many contributing factors including basin influences on water quality that affect biogeochemical cycles and the biological communities supported by the stream.

  7. Effects of propofol versus sevoflurane on cerebral oxygenation and cognitive outcome in patients with impaired cerebral oxygenation

    Directory of Open Access Journals (Sweden)

    Guo JY

    2016-01-01

    Full Text Available Jun-ying Guo,1,* Jie-yu Fang,1,* San-rong Xu,2 Ming Wei,1 Wen-qi Huang1 1Department of Anesthesia, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 2Department of Anesthesia, Zhangzhou Municipal Hospital of Fujian Province, Zhangzhou, Fujian, People’s Republic of China *These authors contributed equally to this work Background: Postoperative neurocognitive dysfunction induced by anesthetics, particularly in elderly patients with impaired oxygenation, is a common complication of surgery and is eliciting increased interest in clinical practice. To investigate the effects of anesthetics on neurocognition, we compared the effects of propofol versus sevoflurane on cerebral oxygenation and cognitive outcome in patients with impaired cerebral oxygenation undergoing general anesthesia. Methods: Sixty-three patients with impaired cerebral oxygenation (jugular venous bulb oxygen saturation [SjvO2] <50% or cerebral blood flow/cerebral metabolic rate of oxygen ([CBF/CMRO2] ≤15% undergoing elective abdominal surgery were randomly allocated into propofol group (group P or sevoflurane group (group S. The clinical parameters and jugular venous bulb blood gas analysis were monitored throughout the surgical procedure. Cognitive function was assessed with the mini-mental state examination and Montreal Cognitive Assessment at day 1 and day 7 following surgery. S100β protein in plasma was measured using enzyme-linked immunosorbent assay. Results: The SjvO2 increased during anesthesia induction and surgery when compared to baseline but had no significant difference between group P and group S. When compared to baseline, the CBF/CMRO2 was increased only at the end of surgery and extubation in group P; however, the CBF/CMRO2 in group S was increased during anesthesia induction at 1 hour, 2 hours, end of surgery, and extubation. Furthermore, the CBF/CMRO2 in group S was significantly higher than that in group P during anesthesia

  8. Cerebral oxygen extraction, oxygen consumption, and regional cerebral blood flow during the aura phase of migraine

    DEFF Research Database (Denmark)

    Friberg, L; Olesen, Jes; Lassen, N A

    1994-01-01

    The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism.......The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism....

  9. Cerebral blood flow and oxygen metabolism in the Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Hideto; Fueki, Noboru; Suzuki, Hisaharu; Sakuragawa, Norio; Iio, Masaaki (National Central Hospital for Mental, Nervous and Muscular Disorders, Tokyo (Japan))

    1992-05-01

    Positron emission tomography (PET) was performed on six patients with the Rett syndrome and the results were compared with the concurrent clinical status of the patients. The cerebral metabolic rate of oxygen (CMRO{sub 2}) was low in five patients, and oxygen extraction fraction (OEF) was low in four patients; both had a tendency to decline with advancing age. Although the cause is unknown, it is suggested that impaired oxidative metabolism exists in the Rett syndrome. An analysis of the distribution among brain regions showed that the ratios of values for the frontal cortex to those for the temporal cortex for both the cerebral blood flow (CBF) and CMRO{sub 2} were lower than those for the controls, which may indicate the loss of of hyperfrontality in the Rett syndrome. Distribution of brain metabolism may be immature in the Rett syndrome. (author).

  10. Effects of rapamycin on cerebral oxygen supply and consumption during reperfusion after cerebral ischemia.

    Science.gov (United States)

    Chi, O Z; Barsoum, S; Vega-Cotto, N M; Jacinto, E; Liu, X; Mellender, S J; Weiss, H R

    2016-03-01

    Activation of the mammalian target of rapamycin (mTOR) leads to cell growth and survival. We tested the hypothesis that inhibition of mTOR would increase infarct size and decrease microregional O2 supply/consumption balance after cerebral ischemia-reperfusion. This was tested in isoflurane-anesthetized rats with middle cerebral artery blockade for 1h and reperfusion for 2h with and without rapamycin (20mg/kg once daily for two days prior to ischemia). Regional cerebral blood flow was determined using a C(14)-iodoantipyrine autoradiographic technique. Regional small-vessel arterial and venous oxygen saturations were determined microspectrophotometrically. The control ischemic-reperfused cortex had a similar blood flow and O2 consumption to the contralateral cortex. However, microregional O2 supply/consumption balance was significantly reduced in the ischemic-reperfused cortex. Rapamycin significantly increased cerebral O2 consumption and further reduced O2 supply/consumption balance in the reperfused area. This was associated with an increased cortical infarct size (13.5±0.8% control vs. 21.5±0.9% rapamycin). We also found that ischemia-reperfusion increased AKT and S6K1 phosphorylation, while rapamycin decreased this phosphorylation in both the control and ischemic-reperfused cortex. This suggests that mTOR is important for not only cell survival, but also for the control of oxygen balance after cerebral ischemia-reperfusion.

  11. Activated oxygen alters cerebral microvascular responses in newborn pigs

    Energy Technology Data Exchange (ETDEWEB)

    Leffler, C.W.; Busiia, D.W.; Armstead, W.M.; Mirro, R.; Thelin, O. (Univ. of Tennessee, Memphis (United States))

    1990-02-26

    In piglets, cerebral ischemia/reperfusion blocks prostanoid dependent cerebral vasodilation to hypercapnia (CO{sub 2}) and hypotension but not prostanoid independent dilation to isoproterenol (Isu) or constriction to norepinephrine (NE). Ischemia/reperfusion increases activated-O{sub 2} production by piglet brains. Using cranial windows in piglets, the authors investigated the hypothesis that activated oxygen can block prostanoid dependent cerebral vasodilator responses to CO{sub 2} and hypotension without altering responses to Isu and NE. Exposure to an activated oxygen generating system of xanthine oxidase, hypoxanthine, and Fe that made about 3 times the activated-O{sub 2} on the brain surface as ischemia/reperfusion caused reversible pial arteriolar dilation. After exposure, pial arteriolar dilation was reduced to CO{sub 2} and hypotension but not to Isu. NE constrictor responses were also unaltered. H{sub 2}O{sub 2} or H{sub 2}O{sub 2} + Fe caused constriction followed by reversible dilation. After exposure, pial arteriolar dilation in response to CO{sub 2} and hypotension was not altered. However, addition of xanthine oxidase and hypoxanthine with H{sub 2}O{sub 2} and Fe totally eliminated pial arteriolar dilator responses to CO{sub 2} and hypotension but did not decrease dilation caused by Isu or constriction caused by NE. The authors conclude that activated oxygen could produce the altered prostanoid dependent pial arteriolar responses observed following ischemia in piglets.

  12. Influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease

    Institute of Scientific and Technical Information of China (English)

    Hui Lu; Ning-Ning Cui; Bin-Cheng Wang

    2016-01-01

    Objective:To study the influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease. Methods:A total of 58 patients with ischemic cerebrovascular disease in our hospital from April 2015 to January 2016 were selected as the study object, and 58 patients were randomly divided into two groups, 29 patients in control group were treated with routine treatment, 29 patients in observation group were treated with remote ischemic preconditioning on the basic treatment of control group, then the cerebral oxygen metabolism and cerebral blood flow indexes of two groups before the treatment and at first, third and sixth month after the treatment were respectively detected and compared.Results:The cerebral oxygen metabolism and cerebral blood flow indexes of two groups before the treatment all showed no significant differences (allP>0.05), while the cerebral oxygen metabolism and cerebral blood flow indexes of observation group at first, third and sixth month after the treatment were all significantly better than those before the treatment, and the results were all significantly better than those of control group at the same time too (allP>0.05).Conclusions: The influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease are better, and its application value for the patients with ischemic cerebrovascular disease is higher.

  13. Comparison of Cerebral Oxygen Saturation and Cerebral Perfusion Computed Tomography in Cerebral Blood Flow in Patients with Brain Injury.

    Science.gov (United States)

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Grigoryeva, Vera

    2016-01-01

    The purpose of this study was to determine the relationship between cerebral tissue oxygen saturation and cerebral blood volume in patients with traumatic brain injury. Perfusion computed tomography of the brain was performed in 25 patients with traumatic brain injury together with simultaneous SctO2 level measurement using cerebral near-infrared oxymetry. The mean age of the injured persons was 34.5±15.6 years (range 15-65); 14 men, 11 women. The Injury Severity Score (ISS) values were 44.4±9.7 (range 25-81). The Glasgow Coma Score (GCS) mean value before the study was 10.6±2.1 (range 5-13). SctO2 ranged from 51 to 89%, mean 62±8.2%. Cerebral blood volume (CBV) values were 2.1±0.67 ml/100 g (min 1.1; max 4.3 ml/100 g). Cerebral blood flow (CBF) was 31.99±13.6 ml/100 g×min. Mean transit time (MTT) values were 5.7±4.5 s (min 2.8; max 34.3 s). The time to peak (TTP) was 22.2±3.1 s. A statistically significant correlation was found between SctO2 level and cerebral blood volume (CBV) level (R=0.9; pperfusion.

  14. The importance of bilateral monitoring of cerebral oxygenation (NIRS): Clinical case of asymmetry during cardiopulmonary bypass secondary to previous cerebral infarction.

    Science.gov (United States)

    Matcan, S; Sanabria Carretero, P; Gómez Rojo, M; Castro Parga, L; Reinoso-Barbero, F

    2017-09-25

    Cerebral oximetry based on near infrared spectroscopy (NIRS) technology is used to determine cerebral tissue oxygenation. We hereby present the clinical case of a 12-month old child with right hemiparesis secondary to prior left middle cerebral artery stroke 8 months ago. The child underwent surgical enlargement of the right ventricular outflow tract (RVOT) with cardiopulmonary bypass. During cardiopulmonary bypass, asymmetric NIRS results were detected between both hemispheres. The utilization of multimodal neuromonitoring (NIRS-BIS) allowed acting on both perfusion pressure and anesthetic depth to balance out the supply and demand of cerebral oxygen consumption. No new neurological sequelae were observed postoperatively. We consider bilateral NIRS monitoring necessary in order to detect asymmetries between cerebral hemispheres. Although asymmetries were not present at baseline, they can arise intraoperatively and its monitoring thus allows the detection and treatment of cerebral ischemia-hypoxia in the healthy hemisphere, which if undetected and untreated would lead to additional neurological damage. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Comparative study between the effects of dexmedetomidine and propofol on cerebral oxygenation during sedation at pediatric cardiac catheterization.

    Science.gov (United States)

    Cetin, Murat; Birbicer, Handan; Hallioglu, Olgu; Orekeci, Gulhan

    2016-01-01

    Nowadays, assessment of brain oxygen saturation, which is simply appliable and noninvasive method, can provide the anesthesia plans to be optimized according to the needs of the brain, which is the main target organ. Brain may be exposed to hypoxia due to supply-demand imbalance of oxygen not only in general anesthesia procedures but also in sedation practices. The aim of the study is to compare the effects of dexmedetomidine and propofol which are widely used agents for pediatric catheterization procedures on brain oxygen saturation using Fore-Sight. A total of 44 patients undergoing diagnostic cardiac catheterization between 1 and 18 years old were included in the study. All patients, who were randomly divided into two groups, had ASA physical status I-II. In Group Propofol (Group P, n = 22),induction of sedation was made by midazolam (0.5 mg,iv) + propofol (1m/kg,iv), and in Group Dexmedetomidine (Group D, n = 22), induction of sedation was made by midazolam (0.5 mg,iv) +dexmedetomidine (1mcg/kg, iv). Throughout the sedation, cerebral tissue oxygen saturation (SctO 2 ) was recorded by Fore-Sight in addition to routine monitoring. There were no statistically significant differences between the groups in terms of demographic data, hemodynamic data and sedation scores. On other hand, statistically significant decreases in cerebral tissue oxygen saturation were detected especially at 5th and 10th minutes, in Group D, while cerebral oxygenation level did not decrease in Group P. Though, statistically significant difference was determined between two groups in terms of cerebral oxygen saturation, the obtained data was not interpreted as cerebral desaturation. As a conclusion, there was a statistically significant but clinically insignificant decrease in cerebral tissue oxygen saturation in dexmedetomidine group compared to propofol group. Although it does not seem to be important in hemodynamic stabilization, we assume that may cause problems for clinically unstable

  16. Comparative study between the effects of dexmedetomidine and propofol on cerebral oxygenation during sedation at pediatric cardiac catheterization

    Directory of Open Access Journals (Sweden)

    Murat Cetin

    2016-01-01

    Full Text Available Introduction: Nowadays, assessment of brain oxygen saturation, which is simply appliable and noninvasive method, can provide the anesthesia plans to be optimized according to the needs of the brain, which is the main target organ. Brain may be exposed to hypoxia due to supply-demand imbalance of oxygen not only in general anesthesia procedures but also in sedation practices. The aim of the study is to compare the effects of dexmedetomidine and propofol which are widely used agents for pediatric catheterization procedures on brain oxygen saturation using Fore-Sight. Material and Methods: A total of 44 patients undergoing diagnostic cardiac catheterization between 1 and 18 years old were included in the study. All patients, who were randomly divided into two groups, had ASA physical status I-II. In Group Propofol (Group P, n = 22,induction of sedation was made by midazolam (0.5 mg,iv + propofol (1m/kg,iv, and in Group Dexmedetomidine (Group D, n = 22, induction of sedation was made by midazolam (0.5 mg,iv +dexmedetomidine (1mcg/kg, iv. Throughout the sedation, cerebral tissue oxygen saturation (SctO 2 was recorded by Fore-Sight in addition to routine monitoring. Results: There were no statistically significant differences between the groups in terms of demographic data, hemodynamic data and sedation scores. On other hand, statistically significant decreases in cerebral tissue oxygen saturation were detected especially at 5th and 10th minutes, in Group D, while cerebral oxygenation level did not decrease in Group P. Though, statistically significant difference was determined between two groups in terms of cerebral oxygen saturation, the obtained data was not interpreted as cerebral desaturation. Conclusion: As a conclusion, there was a statistically significant but clinically insignificant decrease in cerebral tissue oxygen saturation in dexmedetomidine group compared to propofol group. Although it does not seem to be important in hemodynamic

  17. Neonatal cerebral oxygenation is not linked to foetal vasculitis and predicts intraventricular haemorrhage in preterm infants

    DEFF Research Database (Denmark)

    Sorensen, Line C; Maroun, Lisa L; Borch, Klaus;

    2008-01-01

    Aim: The aim of the study was to compare the cerebral tissue oxygenation index (c-TOI) measured by near infrared spectroscopy (NIRS) in infants with and without foetal vasculitis. Methods: Twenty-four infants with placental signs of a foetal inflammatory response (FIR), foetal vasculitis, were.......002). Conclusion: Cerebral oxygenation was not affected in the first day of life in preterm infants born with foetal vasculitis, while cerebral oxygenation in infants that later developed intraventricular haemorrhage was impaired....

  18. Neonatal cerebral oxygenation is not linked to foetal vasculitis and predicts intraventricular haemorrhage in preterm infants

    DEFF Research Database (Denmark)

    Sørensen, Line Carøe; Maroun, Lisa Leth; Borch, K.;

    2008-01-01

    AIM: The aim of the study was to compare the cerebral tissue oxygenation index (c-TOI) measured by near infrared spectroscopy (NIRS) in infants with and without foetal vasculitis. METHODS: Twenty-four infants with placental signs of a foetal inflammatory response (FIR), foetal vasculitis, were.......002). CONCLUSION: Cerebral oxygenation was not affected in the first day of life in preterm infants born with foetal vasculitis, while cerebral oxygenation in infants that later developed intraventricular haemorrhage was impaired Udgivelsesdato: 2008/11...

  19. Methods for assessing biochemical oxygen demand (BOD): a review.

    Science.gov (United States)

    Jouanneau, S; Recoules, L; Durand, M J; Boukabache, A; Picot, V; Primault, Y; Lakel, A; Sengelin, M; Barillon, B; Thouand, G

    2014-02-01

    The Biochemical Oxygen Demand (BOD) is one of the most widely used criteria for water quality assessment. It provides information about the ready biodegradable fraction of the organic load in water. However, this analytical method is time-consuming (generally 5 days, BOD5), and the results may vary according to the laboratory (20%), primarily due to fluctuations in the microbial diversity of the inoculum used. Work performed during the two last decades has resulted in several technologies that are less time-consuming and more reliable. This review is devoted to the analysis of the technical features of the principal methods described in the literature in order to compare their performances (measuring window, reliability, robustness) and to identify the pros and the cons of each method.

  20. Activation-induced resetting of cerebral oxygen and glucose uptake in the rat

    DEFF Research Database (Denmark)

    Madsen, P L; Linde, R; Hasselbalch, S G

    1998-01-01

    In the clinical setting it has been shown that activation will increase cerebral glucose uptake in excess of cerebral oxygen uptake. To study this phenomenon further, this study presents an experimental setup that enables precise determination of the ratio between cerebral uptake of glucose...... and oxygen in the awake rat. Global CBF was measured by the Kety-Schmidt technique, and the ratio between cerebral uptake rates for oxygen, glucose, and lactate was calculated from cerebral arterial-venous differences. During baseline conditions, rats were kept in a closed box designed to minimize...... interference. During baseline conditions CBF was 1.08 +/- 0.25 mL x g(-1) x minute(-1), and the cerebral oxygen to glucose uptake ratio was 5.5. Activation was induced by opening the sheltering box for 6 minutes. Activation increased CBF to 1.81 mL x g(-1) x minute(-1). During activation cerebral glucose...

  1. Simple exercises that significantly increase cerebral blood flow and cerebral oxygenation

    CERN Document Server

    Gersten, Alexander; Raz, Amir; Fried, Robert

    2011-01-01

    We tested the hypothesis that simple exercises may significantly increase cerebral blood flow (CBF) and/or cerebral oxygenation. Eighteen subjects ranging in age from nineteen to thirty nine participated in a four-stage study during which measurements of end tidal CO_2 (EtCO2 - by capnometer) and local brain oxygenation (by near-infrared spectroscopy (NIRS) sensor) were taken. The four stages were 1) baseline, 2) breathing exercises, 3) solving an arithmetic problem, and 4) biofeedback. During the breathing exercises there was a significant increase in EtCO2 indicating a significant increase in global CBF. The increase in global CBF was estimated on the basis of a theoretical model. During the arithmetic and biofeedback tasks there was a significant increase in the local (Fp1) oxygenation, but it varied between the different participants. The results may lead to new clinical applications of CBF and brain oxygenation monitoring and behavioral control. We foresee future more detailed investigations in the contr...

  2. Correlation between cerebral oxygen metabolism and cerebral blood flow simultaneously measured before and after acetazolamide administration

    Science.gov (United States)

    Yamaguchi, Hiroichiro; Yamauchi, Hideto; Hazama, Shiro; Hamamoto, Hirotsugu; Inoue, Nobuhiro

    1999-10-01

    The cerebral circulation and metabolism of ten preoperative cardiac surgery patients were assessed. Alterations in regional cerebral blood flow (rCBF), measured by 123I-N- isopropyl-p-iodo-amphetamine single-photon emission computed tomography, and in cerebral oxygen metabolism, simultaneously detected by near-infrared spectroscopy (NIRS) before and after acetazolamide administration, were investigated. The rCBF (ml/min/100 g) increased significantly from 40.21 +/- 7.65 to 56.24 +/- 13.69 (p equals 0.001), and a significant increase in oxyhemoglobin (Oxy-Hb) of 13.9% (p equals 0.0022) and total hemoglobin (Total-Hb) of 5.7% (0.0047) along with a significant decrease in deoxyhemoglobin (Deoxy-Hb) of 8.9% (p equals 0.0414) were observed concomitantly. Thus, the Oxy-Hb/Total- Hb ratio (%Oxy-Hb) rose significantly from 67.26 +/- 9.82% to 72.98 +/- 8.09% (p equals 0.0022). Examination of the relationships between individual parameters showed that the percentage changes in rCBF and Oxy-Hb were significantly correlated (r equals 0.758, p equals 0.011). The percentage changes in rCBF and %Oxy-Hb were also correlated significantly (r equals 0.740, p equals 0.014). In conclusion, this evidence suggested that NIRS is able to detect relative changes in cerebral hemodynamics and reflect luxury perfusion induced by acetazolamide.

  3. Cerebral oxygenation decreases during exercise in humans with beta-adrenergic blockade

    DEFF Research Database (Denmark)

    Seifert, T.; Rasmussen, P.; Secher, Niels H.

    2009-01-01

    AIM: Beta-blockers reduce exercise capacity by attenuated increase in cardiac output, but it remains unknown whether performance also relates to attenuated cerebral oxygenation. METHODS: Acting as their own controls, eight healthy subjects performed a continuous incremental cycle test to exhaustion...... with or without administration of the non-selective beta-blocker propranolol. Changes in cerebral blood flow velocity were measured with transcranial Doppler ultrasound and those in cerebral oxygenation were evaluated using near-infrared spectroscopy and the calculated cerebral mitochondrial oxygen tension...

  4. The effects of sevoflurane and propofol anesthesia on cerebral oxygenation in gynecological laparoscopic surgery

    OpenAIRE

    Kim, Sung-Jin; Kwon, Jae Young; Cho, Ah-Reum; Kim, Hae Kyu; Kim, Tae Kyun

    2011-01-01

    Background Both the Trendelenburg position and pneumoperitoneum with carbon dioxide have been reported to increase intracranial pressure (ICP) and to alter cerebral blood flow or cerebral blood volume. Also anesthetic agents have variable effects on cerebral hemodynamics and ICP. The present study was conducted to determine whether regional cerebral oxygen saturation (rSO2) values differ between propofol and sevoflurane anesthesia during laparoscopic surgery in the Trendelenburg position. Met...

  5. Optimization of the determination of chemical oxygen demand in wastewaters.

    Science.gov (United States)

    Silva, Alexandra M E Viana da; Silva, Ricardo J N Bettencourt da; Camões, M Filomena G F C

    2011-08-12

    Chemical oxygen demand (COD) is one of the most relevant chemical parameters for the management of wastewater treatment facilities including the control of the quality of an effluent. The adequacy of decisions based on COD values relies on the quality of the measurements. Cost effective management of the minor sources of uncertainty can be applied to the analytical procedure without affecting measurement quality. This work presents a detailed assessment of the determination of COD values in wastewaters, according to ISO6060:1989 standard, which can support reduction of both measurement uncertainty and cost of analysis. This assessment includes the definition of the measurement traceability chain and the validation of the measurement procedure supported on sound and objective criteria. Detailed models of the measurement performance, including uncertainty, developed from the Differential Approach, were successfully validated by proficiency tests. The assumption of the measurement function linearity of the uncertainty propagation law was tested through the comparison with the numerical Kragten method. The gathered information supported the definition of strategies for measurement uncertainty or cost reduction. The developed models are available as electronic supplementary material, in an MS-Excel file, to be updated with the user's data.

  6. Chitosan on Reducing Chemical Oxygen Demands in Laundry Waste Water

    Directory of Open Access Journals (Sweden)

    Tri Joko

    2016-09-01

    Full Text Available Laundry liquid waste contains several chemical substances in detergent raw materials such as phosphate, surfactants, ammonia, and total suspended solids. The existence of detergent in high concentrations and exceeds the quality standards that have been estabilished in a body of water can lead to cases of enviromental pollution in the form of increased turbidity an Chemical Oxygen Demands (COD levels. Therefore in order to maintain and to ensure the availabillity of water in terms of quality, it requires coagulation-flocculation process to laundry liquid waste before discharging into water bodies. This study aims to determine the decrease of COD levels and turbidity level in laundry liquid waste using chitosan coagulant in “X” laundry, Tembalang District, Semarang. The research is a quasi experimental study with pretest-posttest with control group research design with 6 times replication. The total samples are 60 in wich 24 tested for the levels of turbidity and 6 controls. The test results of Kruskal-Wallis with significance p-value < 0,05 indicates that dosage variation (p=0,000 gives different levels of COD and dosage variation (p=0,000 provide 755,97 mg/l and the advantage levels of turbidity before treatment was 516,20 NTU. The optimum dosage of chitosan coagulant is on the dose of 200 mg/l with the effectiveness decrease of COD levels and turbidity levels on 72,67% an 98,67% respectively.

  7. Correlation between Biochemical Oxygen Demand and Chemical Oxygen Demand for Various Wastewater Treatment Plants in Egypt to Obtain the Biodegradability Indices

    OpenAIRE

    Khaled Zaher Abdallah; Gina Hammam

    2014-01-01

    Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) are the most commonly used parameters for the characterization of wastewaters. Both of these parameters have advantages and disadvantages, and the choice usually depends on many factors such as the time period required to determine each one of them. It is essential to obtain a correlation between BOD5 and COD for various wastewater treatment plants, to help in the design and operation of these plants. In this paper, the biodegr...

  8. Prognostic value of cerebral tissue oxygen saturation during neonatal extracorporeal membrane oxygenation

    Science.gov (United States)

    Clair, Marie-Philippine; Rambaud, Jérôme; Flahault, Adrien; Guedj, Romain; Guilbert, Julia; Guellec, Isabelle; Durandy, Amélie; Demoulin, Maryne; Jean, Sandrine; Mitanchez, Delphine; Chalard, François; Sileo, Chiara; Carbajal, Ricardo; Renolleau, Sylvain

    2017-01-01

    Objectives Extracorporeal membrane oxygenation support is indicated in severe and refractory respiratory or circulatory failures. Neurological complications are typically represented by acute ischemic or hemorrhagic lesions, which induce higher morbidity and mortality. The primary goal of this study was to assess the prognostic value of cerebral tissue oxygen saturation (StcO2) on mortality in neonates and young infants treated with ECMO. A secondary objective was to evaluate the association between StcO2 and the occurrence of cerebral lesions. Study design This was a prospective study in infants < 3 months of age admitted to a pediatric intensive care unit and requiring ECMO support. Measurements The assessment of cerebral perfusion was made by continuous StcO2 monitoring using near-infrared spectroscopy (NIRS) sensors placed on the two temporo-parietal regions. Neurological lesions were identified by MRI or transfontanellar echography. Results Thirty-four infants <3 months of age were included in the study over a period of 18 months. The ECMO duration was 10±7 days. The survival rate was 50% (17/34 patients), and the proportion of brain injuries was 20% (7/34 patients). The mean StcO2 during ECMO in the non-survivors was reduced in both hemispheres (p = 0.0008 right, p = 0.03 left) compared to the survivors. StcO2 was also reduced in deceased or brain-injured patients compared to the survivors without brain injury (p = 0.002). Conclusion StcO2 appears to be a strong prognostic factor of survival and of the presence of cerebral lesions in young infants during ECMO. PMID:28278259

  9. Cold-water immersion decreases cerebral oxygenation but improves recovery after intermittent-sprint exercise in the heat.

    Science.gov (United States)

    Minett, G M; Duffield, R; Billaut, F; Cannon, J; Portus, M R; Marino, F E

    2014-08-01

    This study examined the effects of post-exercise cooling on recovery of neuromuscular, physiological, and cerebral hemodynamic responses after intermittent-sprint exercise in the heat. Nine participants underwent three post-exercise recovery trials, including a control (CONT), mixed-method cooling (MIX), and cold-water immersion (10 °C; CWI). Voluntary force and activation were assessed simultaneously with cerebral oxygenation (near-infrared spectroscopy) pre- and post-exercise, post-intervention, and 1-h and 24-h post-exercise. Measures of heart rate, core temperature, skin temperature, muscle damage, and inflammation were also collected. Both cooling interventions reduced heart rate, core, and skin temperature post-intervention (P  0.05). CWI reduced cerebral oxygenation compared to MIX and CONT post-intervention (P < 0.01). Furthermore, cooling interventions reduced cortisol 1-h post-exercise (P < 0.01), although only CWI blunted creatine kinase 24-h post-exercise compared to CONT (P < 0.05). Accordingly, improvements in neuromuscular recovery after post-exercise cooling appear to be disassociated with cerebral oxygenation, rather reflecting reductions in thermoregulatory demands to sustain force production. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Impaired cerebral blood flow and oxygenation during exercise in type 2 diabetic patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Seifert, Thomas; Brassard, Patrice

    2015-01-01

    cerebral artery blood flow velocity. Cerebral oxygenation and metabolism were evaluated from the arterial-to-venous differences for oxygen, glucose, and lactate. Blood pressure was comparable during exercise between the two groups. However, the partial pressure of arterial carbon dioxide was lower......Endothelial vascular function and capacity to increase cardiac output during exercise are impaired in patients with type 2 diabetes (T2DM). We tested the hypothesis that the increase in cerebral blood flow (CBF) during exercise is also blunted and, therefore, that cerebral oxygenation becomes...... at higher workloads in T2DM patients and their work capacity and increase in cardiac output were only ~80% of that established in the control subjects. CBF and cerebral oxygenation were reduced during exercise in T2DM patients (P

  11. Oxygen saturations of medical inpatients in a Malawian hospital: cross-sectional study of oxygen supply and demand

    Directory of Open Access Journals (Sweden)

    Hywel-Gethin Tudur Evans

    2012-05-01

    Full Text Available Normal 0 false false false EN-GB JA X-NONE Oxygen is a World Health Organisation listed essential drug yet provision of oxygen in developing countries often fails to meet demand.  The aim of this study was to evaluate the need for supplementary oxygen against oxygen delivery capacity at a large teaching hospital in Malawi.  A cross‐sectional study of all adult medical inpatients and assessment of oxygen provision over a 24‐hour period was conducted.    144 patients were included in the study, 14 of whom met local and international criteria for oxygen therapy (oxygen saturations of <90%.  Four were receiving oxygen.  Of the 8 oxygen concentrators available, only 4 were functional.  In conclusion, we identified a need for oxygen that was greater than the supply.

  12. Cerebral blood oxygenation changes induced by visual stimulation in humans

    Science.gov (United States)

    Wenzel, Rudiger; Obrig, Hellmuth; Ruben, Jan; Villringer, Kersten; Thiel, Andreas; Bernarding, Johannes; Dirnagl, Ulrich; Villringer, Arno

    1996-10-01

    We examined local changes of cerebral oxygenation in response to visual stimuli by means of near infrared spectroscopy. A sharply outlined colored moving stimulus which is expected to evoke a broad activation of the striate and prestriate cortex was presented to sixteen healthy subjects. Six of these subjects were also exposed to a colored stationary and a gray stationary stimulus. In two subjects the colored moving stimulus was tested against the colored stationary with an optode position presumably over area V5/MT. As a control condition, subjects performed a simple finger opposition task. Since the calcarine fissure varies greatly with respect to bony landmarks, optodes were positioned individually according to 3D reconstructed magnetic resonance imaging (MRI). Concentration changes in oxyhemoglobin (oxy-Hb) and deoxyhemoglobin (deoxy-Hb) were continuously monitored with a temporal resolution of 1 s, using an NIRO 500. In response to the visual stimulus, the grand average across all sixteen subjects resulted in a significant increase in oxy-Hb of 0.33 +/- 0.09 arbitrary units mirrored by a significant decrease in deoxy-Hb of -0.18 +/- 0.02 arbitrary units, while the motor control condition elicited no significant changes in any parameters. When the near infrared spectroscopy probes were positioned over area V5/MT, the drop of deoxy-Hb associated with the moving stimulus was significantly more pronounced than with the stationary stimulus in both subjects examined. No significant differences between the visual stimuli were observed at the optode position close to the calcarine fissure. The oxygenation changes observed in this study are consistent with the pattern we have reported for motor activation. They are in line with physiological considerations and functional MRI studies relying on blood oxygenation level-dependent contrast.

  13. Cerebral oxygen saturation: graded response to carbon dioxide with isoxia and graded response to oxygen with isocapnia.

    Directory of Open Access Journals (Sweden)

    W Alan C Mutch

    Full Text Available BACKGROUND: Monitoring cerebral saturation is increasingly seen as an aid to management of patients in the operating room and in neurocritical care. How best to manipulate cerebral saturation is not fully known. We examined cerebral saturation with graded changes in carbon dioxide tension while isoxic and with graded changes in oxygen tension while isocapnic. METHODOLOGY/PRINCIPAL FINDINGS: The study was approved by the Research Ethics Board of the University Health Network at the University of Toronto. Thirteen studies were undertaken in healthy adults with cerebral oximetry by near infrared spectroscopy. End-tidal gas concentrations were manipulated using a model-based prospective end-tidal targeting device. End-tidal carbon dioxide was altered ±15 mmHg from baseline in 5 mmHg increments with isoxia (clamped at 110±4 mmHg. End-tidal oxygen was changed to 300, 400, 500, 80, 60 and 50 mmHg under isocapnia (37±2 mmHg. Twelve studies were completed. The end-tidal carbon dioxide versus cerebral saturation fit a linear relationship (R(2 = 0.92±0.06. The end-tidal oxygen versus cerebral saturation followed log-linear behaviour and best fit a hyperbolic relationship (R(2 = 0.85±0.10. Cerebral saturation was maximized in isoxia at end-tidal carbon dioxide of baseline +15 mmHg (77±3 percent. Cerebral saturation was minimal in isocapnia at an end-tidal oxygen tension of 50 mmHg (61±3 percent. The cerebral saturation during normoxic hypocapnia was equivalent to normocapnic hypoxia of 60 mmHg. CONCLUSIONS/SIGNIFICANCE: Hypocapnia reduces cerebral saturation to an extent equivalent to moderate hypoxia.

  14. Is cerebral oxygenation negatively affected by infusion of norepinephrine in healthy subjects?

    DEFF Research Database (Denmark)

    Brassard, P.; Seifert, T.; Secher, Niels H.

    2009-01-01

    )) and internal jugular venous oxygen saturation (Sjv(O2)), middle cerebral artery mean flow velocity (MCA Vmean), cardiac output (CO), and arterial partial pressure for carbon dioxide (Pa(CO2)) were evaluated. RESULTS: MAP increased from 88 (79-101) [median (range)] to 115 (98-128) mm Hg with increasing doses......BACKGROUND: Vasopressor agents are commonly used to increase mean arterial pressure (MAP) in order to secure a pressure gradient to perfuse vital organs. The influence of norepinephrine on cerebral oxygenation is not clear. The aim of this study was to evaluate the impact of the infusion...... of norepinephrine on cerebral oxygenation in healthy subjects. METHODS: Three doses of norepinephrine (0.05, 0.1, and 0.15 microg kg(-1) min(-1) for 20 min each) were infused in nine healthy subjects [six males; 26 (6) yr, mean (SD)]. MAP, cerebral oxygenation characterized by frontal lobe oxygenation (Sc(O2...

  15. Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion

    Directory of Open Access Journals (Sweden)

    Tomoyasu Takahiro

    2008-10-01

    Full Text Available Abstract Objective We examined the hypothesis that higher cerebral oxygen saturation (rSO2 during RCP is correlated with urinary output. Methods Between December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 ≦ 75% and Group B (rSO2 Results Seven and 5 patients were assigned to Group A and Group B, respectively. Group A was characterized by mean radial arterial pressure (37.9 ± 9.6 vs 45.8 ± 7.8 mmHg; P = 0.14 and femoral arterial pressure (6.7 ± 6.1 vs 20.8 ± 14.6 mmHg; P = 0.09 compared to Group B. However, higher urinary output during CPB (1.03 ± 1.18 vs 0.10 ± 0.15 ml·kg-1·h-1; P = 0.03. Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 ± 1.4 vs 1.7 ± 1.0 mg/kg; P = 0.03. Conclusion Higher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation.

  16. Extra-cerebral oxygenation influence on near-infrared-spectroscopy-determined frontal lobe oxygenation in healthy volunteers

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Rasmussen, Peter; Siebenmann, Christoph

    2015-01-01

    regression analysis estimated the influence of extra-cerebral oxygenation as exemplified by skin oxygenation (Sskin O2 ) on Sc O2 in 21 healthy subjects exposed to whole-body exercise in hypoxia (Fi O2 = 12%; n = 10) and normoxia (n = 12), whole-body heating, hyperventilation (n = 21), administration...

  17. Oxygenation and hemodynamics in left and right cerebral hemispheres during induction of veno-arterial extracorporeal membrane oxygenation.

    NARCIS (Netherlands)

    Heijst, A.F.J. van; Liem, D.; Hopman, J.C.W.; Staak, F.H.J.M. van der; Sengers, R.C.A.

    2004-01-01

    OBJECTIVE: Oxygenation and hemodynamics in the left and right cerebral hemispheres were measured during induction of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). STUDY DESIGN: Using near infrared spectrophotometry, effects of right common carotid artery (RCCA) and right internal

  18. Ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation: effects on cerebral oxygenation and hemodynamics.

    NARCIS (Netherlands)

    Heyst, A.F.J. van; Staak, F.H.J.M. van der; Hopman, J.C.W.; Tanke, R.B.; Sengers, R.C.A.; Liem, K.D.

    2003-01-01

    OBJECTIVE: To investigate the effect on cerebral oxygenation and hemodynamics of a patent ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation in a lamb model. DESIGN: Prospective intervention study in animals. SETTING: Animal research laboratory of a

  19. Healthy aging, memory subsystems and regional cerebral oxygen consumption.

    Science.gov (United States)

    Eustache, F; Rioux, P; Desgranges, B; Marchal, G; Petit-Taboué, M C; Dary, M; Lechevalier, B; Baron, J C

    1995-07-01

    The present study was designed to search for concomitant age-related changes in memory subsystems, defined according to current structural theories, and resting oxygen consumption in selected brain regions. We have investigated a sample of subjects between 20 and 68 years of age and strictly screened for their good health. We applied in the same subjects a battery of neuropsychological tests selected to investigate several memory subsystems, and high-resolution positron imaging with stereotaxic localization to study a purposely limited number of cerebral structures, selected on a priori hypotheses to match the different memory subsystems. Our results showed significant age-related changes in performance on some tests, consistent with the literature, including an increase in semantic memory and a decrease in both working memory (central executive system) and verbal episodic and explicit memory. There was also an age-related linear decrease in global brain oxygen consumption which regionally reached statistical significance for the neocortical areas and the left thalamus. There was a limited number of significant, age-independent correlations between the raw psychometric test scores and resting regional oxidative metabolism. Consistent with our present understanding of the functional anatomy of memory, the Associate Learning scores (verbal episodic and explicit memory) were positively correlated with left hippocampal and thalamic metabolism. The positive relationships found between right hippocampal metabolism and performance in the Associate Learning and the Brown-Peterson tests were less expected but would be consistent with findings from recent PET activation studies. The results from this investigation are discussed in the light of current knowledge concerning the neuropsychology and the neurobiology of both aging and memory.

  20. Improved Quantification of Cerebral Vein Oxygenation Using Partial Volume Correction.

    Science.gov (United States)

    Ward, Phillip G D; Fan, Audrey P; Raniga, Parnesh; Barnes, David G; Dowe, David L; Ng, Amanda C L; Egan, Gary F

    2017-01-01

    Purpose: Quantitative susceptibility mapping (QSM) enables cerebral venous characterization and physiological measurements, such as oxygen extraction fraction (OEF). The exquisite sensitivity of QSM to deoxygenated blood makes it possible to image small veins; however partial volume effects must be addressed for accurate quantification. We present a new method, Iterative Cylindrical Fitting (ICF), to estimate voxel-based partial volume effects for susceptibility maps and use it to improve OEF quantification of small veins with diameters between 1.5 and 4 voxels. Materials and Methods: Simulated QSM maps were generated to assess the performance of the ICF method over a range of vein geometries with varying echo times and noise levels. The ICF method was also applied to in vivo human brain data to assess the feasibility and behavior of OEF measurements compared to the maximum intensity voxel (MIV) method. Results: Improved quantification of OEF measurements was achieved for vessels with contrast to noise greater than 3.0 and vein radii greater than 0.75 voxels. The ICF method produced improved quantitative accuracy of OEF measurement compared to the MIV approach (mean OEF error 7.7 vs. 12.4%). The ICF method provided estimates of vein radius (mean error partial volume maps (root mean-squared error partial volume estimates from the ICF method.

  1. Cerebral oxygenation and metabolism during exercise following three months of endurance training in healthy overweight males

    DEFF Research Database (Denmark)

    Seifert, T; Rasmussen, P; Brassard, P

    2009-01-01

    Endurance training improves muscular and cardiovascular fitness, but the effect on cerebral oxygenation and metabolism remains unknown. We hypothesized that 3 mo of endurance training would reduce cerebral carbohydrate uptake with maintained cerebral oxygenation during submaximal exercise. Healthy...... overweight males were included in a randomized, controlled study (training: n = 10; control: n = 7). Arterial and internal jugular venous catheterization was used to determine concentration differences for oxygen, glucose, and lactate across the brain and the oxygen-carbohydrate index [molar uptake of oxygen...... with a lower plasma epinephrine concentration (P exercising at 70% of maximal oxygen uptake (approximately 211 W). Before training, both OCI (3.9 +/- 0.9) and DeltaP(Mito)O(2) (-22 mmHg) decreased (P

  2. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward;

    2016-01-01

    The objective of this review is to evaluate the existing literature with regard to the influence of propofol and remifentanil total intravenous anaesthesia (TIVA) on cerebral perfusion and oxygenation in healthy pigs. Anaesthesia has influence on cerebral haemodynamics and it is important not onl...

  3. Persistent resetting of the cerebral oxygen/glucose uptake ratio by brain activation

    DEFF Research Database (Denmark)

    Madsen, P L; Hasselbalch, S G; Hagemann, L P;

    1995-01-01

    fraction of the activation-induced excess glucose uptake. These data confirm earlier reports that brain activation can induce resetting of the cerebral oxygen/glucose consumption ratio, and indicate that the resetting persists for a long period after cerebral activation has been terminated and physiologic...

  4. Modeling of cerebral oxygen transport based on in vivo microscopic imaging of microvascular network structure, blood flow and oxygenation

    Directory of Open Access Journals (Sweden)

    Louis Gagnon

    2016-08-01

    Full Text Available Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1 interpretation of functional Magnetic Resonance Imaging (fMRI signals, and (2 investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These bottom-up models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.

  5. Novel optoacoustic system for noninvasive continuous monitoring of cerebral venous blood oxygenation

    Science.gov (United States)

    Petrov, Yuriy; Petrov, Irene Y.; Prough, Donald S.; Esenaliev, Rinat O.

    2012-02-01

    Traumatic brain injury (TBI) and spinal cord injury are a major cause of death for individuals under 50 years of age. In the USA alone, 150,000 patients per year suffer moderate or severe TBI. Moreover, TBI is a major cause of combatrelated death. Monitoring of cerebral venous blood oxygenation is critically important for management of TBI patients because cerebral venous blood oxygenation below 50% results in death or severe neurologic complications. At present, there is no technique for noninvasive, accurate monitoring of this clinically important variable. We proposed to use optoacoustic technique for noninvasive monitoring of cerebral venous blood oxygenation by probing cerebral veins such as the superior sagittal sinus (SSS) and validated it in animal studies. In this work, we developed a novel, medical grade optoacoustic system for continuous, real-time cerebral venous blood oxygenation monitoring and tested it in human subjects at normal conditions and during hyperventilation to simulate changes that may occur in patients with TBI. We designed and built a highly-sensitive optoacoustic probe for SSS signal detection. Continuous measurements were performed in the near infrared spectral range and the SSS oxygenation absolute values were automatically calculated in real time using a special algorithm developed by our group. Continuous measurements performed at normal conditions and during hyperventilation demonstrated that hyperventilation resulted in approximately 12% decrease of cerebral venous blood oxygenation.

  6. Effects of arteriovenous fistulas on cardiac oxygen supply and demand

    NARCIS (Netherlands)

    Bos, W.J.W.; Zietse, R.; Wesseling, K.H.; Westerhof, N.

    1999-01-01

    Background. Arteriovenous (AV) fistulas used for hemodialysis access may affect cardiac load by increasing the preload while decreasing the afterload. In dogs, AV fistulas have also been shown to affect coronary perfusion negatively. We investigated the net effect of AV fistulas on cardiac oxygen su

  7. COMPARISON OF METHODS TO DETERMINE OXYGEN DEMAND FOR BIOREMEDIATION OF A FUEL CONTAMINATED AQUIFER

    Science.gov (United States)

    Four analytical methods were compared for estimating concentrations of fuel contaminants in subsurface core samples. The methods were total organic carbon, chemical oxygen demand, oil and grease, and a solvent extraction of fuel hydrocarbons combined with a gas chromatographic te...

  8. Cerebral tissue oxygen saturation and extraction in preterm infants before and after blood transfusion

    NARCIS (Netherlands)

    van Hoften, Jacorina C. R.; Verhagen, Elise A.; Keating, Paul; ter Horst, Hendrik J.; Bos, Arend F.

    2010-01-01

    Objective Preterm infants often need red blood cell (RBC) transfusions. The aim of this study was to determine whether haemoglobin levels before transfusion were associated with regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) and whether RBC tran

  9. Sediment oxygen demand in upper Klamath and Agency lakes, Oregon, 1999

    Science.gov (United States)

    Wood, T.M.

    2001-06-28

    Sediment oxygen demand (SOD) was measured in two shallow, interconnected lakes in southern Oregon, Upper Klamath Lake and Agency Lake, in spring and late summer of 1999. Upper Klamath Lake contains populations of two endangered fishes, the shortnose sucker and the Lost River sucker, and low dissolved oxygen concentrations in summer are thought to be one factor affecting sucker populations.

  10. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    Science.gov (United States)

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  11. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    Science.gov (United States)

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  12. [Evaluation of cerebral oxygenation in newborns with prematurity apnea: new frequency domain NIR oximeter].

    Science.gov (United States)

    Pratesi, S; Donzelli, G

    2000-01-01

    Near infrared spectroscopy (NIRS) is a non invasive, portable, safe technique for monitoring cerebral oxygenation and haemodynamics. A new frequency-domain tissue oximeter based on a multi-distance measurement protocol is presented. The effects of apneic episodes on cerebral and peripheral arterial oxygen saturation (SatO2) in preterm newborns, as monitored by NIRS and by pulse oximetry, are reported. The study population consist of 5 preterms (26 to 30 weeks of gestational age), in the second week of postnatal age, affected by apnea of prematurity. NIRS and pulse oximetric measurements were made contemporarily for a 40-minutes period for each infant. All monitorized apneic events were associated with bradicardia, and resolved spontaneously or after tactile stimulation. As results: a) there was always cerebral deoxygenation in association with apneic events, b) the mean SatO2 as measured by NIRS was slightly lower than the pulse oximeter readings, c) cerebral SatO2 decreased faster and the absolute value of the cerebral SaO2 decrease was greater than that measured peripherally (mean value of 27 versus 13%), d) increases of cerebral deoxyhemoglobin and total hemoglobin and a decrease of oxyhemoglobin were also observed. These preliminary results show that peripheral oxygen saturation measurements as measured by pulse oximetry could not always reflect brain oxygenation.

  13. The effect of mayfly (Hexagenia spp.) burrowing activity on sediment oxygen demand in western Lake Erie

    Science.gov (United States)

    Edwards, William J.; Soster, Frederick M.; Matisoff, Gerald; Schloesser, Donald W.

    2009-01-01

    Previous studies support the hypothesis that large numbers of infaunal burrow-irrigating organisms in the western basin of Lake Erie may increase significantly the sediment oxygen demand, thus enhancing the rate of hypolimnetic oxygen depletion. We conducted laboratory experiments to quantify burrow oxygen dynamics and increased oxygen demand resulting from burrow irrigation using two different year classes of Hexagenia spp. nymphs from western Lake Erie during summer, 2006. Using oxygen microelectrodes and hot film anemometry, we simultaneously determined oxygen concentrations and burrow water flow velocities. Burrow oxygen depletion rates ranged from 21.7 mg/nymph/mo for 15 mm nymphs at 23 °C to 240.7 mg/nymph/mo for 23 mm nymphs at 13 °C. Sealed microcosm experiments demonstrated that mayflies increase the rate of oxygen depletion by 2-5 times that of controls, depending on size of nymph and water temperature, with colder waters having greater impact. At natural population densities, nymph pumping activity increased total sediment oxygen demand 0.3-2.5 times compared to sediments with no mayflies and accounted for 22-71% of the total sediment oxygen demand. Extrapolating laboratory results to the natural system suggest that Hexagenia spp. populations may exert a significant control on oxygen depletion during intermittent stratification. This finding may help explain some of the fluctuations in Hexagenia spp. population densities in western Lake Erie and suggests that mayflies, by causing their own population collapse irrespective of other environmental conditions, may need longer term averages when used as a bio-indicator of the success of pollution-abatement programs in western Lake Erie and possibly throughout the Great Lakes.

  14. Oxygen, a key factor regulating cell behaviour during neurogenesis and cerebral diseases

    Directory of Open Access Journals (Sweden)

    Kuan eZhang

    2011-04-01

    Full Text Available Oxygen is vital to maintain the normal functions of alomost all the organs, especially for brain which is one of the heaviest oxygen consumers in the body. The important roles of oxygen on the brain are not only reflected in the development, but also showed in the pathological processes of many cerebral diseases. In the current review, we summarized the oxygen levels in brain tissues tested by real-time measurements during the embryonic and adult neurogenesis, the cerebral diseases or in the hyperbaric/hypobaric oxygen environment. Oxygen concentration is low in fetal brain (0.01%- 1% and in adult brain (1.5%-7%, decreased during stroke, and increased in hyperbaric oxygen environment. In addition, we reviewed the effects of oxygen tensions on the behaviors of neural stem cells (NSCs in vitro cultures at different oxygen concentration (2%-20% and in vivo niche during different pathological states and in hyperbaric/hypobaric oxygen environment. Moderate hypoxia (3%-10% is known can promote the proliferation of NSCs and enhance the differentiation of NSCs into the TH-positive neurons. Next, we briefly presented the oxygen-sensitive molecular mechanisms regulating NSCs proliferation and differentiation recently found including the Notch, BMP and Wnt pathways. Finally, the future perspectives about the roles of oxygen on brain and NSCs were given.

  15. Application of Ozone and Oxygen to Reduce Chemical Oxygen Demand and Hydrogen Sulfide from a Recovered Paper Processing Plant

    Directory of Open Access Journals (Sweden)

    Patricia A. Terry

    2010-01-01

    Full Text Available A pilot study was performed at the Fox River Fiber recovered paper processing company in DePere, Wisconsin, to determine the extent to which injection of oxygen and ozone could reduce the high chemical oxygen demand, COD, in the effluent and the effectiveness of the ozone/oxygen stream in suppressing production of hydrogen sulfide gas in downstream sewage lines. Adaptive Ozone Solutions, LLC, supplied the oxygen/ozone generation and injection system. Samples were analyzed both before and after oxygen/ozone injection. Hydrogen sulfide gas was continuously monitored at sewer stations downstream of Fox River Fiber. Results showed that with a very short contact time, effluent COD was reduced by over 15%. A simple kinetic model predicts that a contact time of fewer than 30 minutes could reduce COD by as much as 60%. In addition, downstream hydrogen sulfide gas production in the sewage mains was also better controlled, such that costly Bioxide applications could be reduced.

  16. Time-dependent changes in cerebral blood flow after acetazolamide loading into patients with hemodynamic cerebral ischemia. Relationship to cerebral oxygen metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Masakazu [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2001-10-01

    The aim of this study was to clarify the relationship between time-dependent changes in cerebral blood flow (CBF) after acetazolamide loading and cerebral oxygen metabolism (CMRO{sub 2}). The subjects consisted of 30 patients with severe stenosis or occlusion of either internal carotid, middle cerebral, or vertebro-basilar artery. Regional CBF was measured at the resting state and 6, 16 and 30 minutes after intravenous administration of 1 gram of acetazolamide using the positron emission tomography in combination with the [{sup 15}O] H{sub 2}O bolus-injection method. Prior to CBF study, regional cerebral oxygen extraction fraction (OEF) was measured using the [{sup 15}O] O{sub 2} inhalation method. Regional CMRO{sub 2} was calculated based on CBF and OEF. According to the time-dependent changes in CBF responses to acetazolamide loading, the CBF responses are classified into good response type, paradoxical response type, and poor response type. Good response type (CBF increase rate more than 20% 6 minutes after acetazolamide loading), paradoxical response type (decrease of CBF 6 minutes after acetazolamide loading) and poor response type (CBF increase rate less than 20% 6 minutes after acetazolamide loading) were identified in 39, 11 and 10 areas, respectively. Brain areas with good response type showed normal OEF and normal CMRO{sub 2}. Brain areas with paradoxical response type showed increased OEF and normal CMRO{sub 2}. Brain areas with poor response type showed normal OEF and decreased CMRO{sub 2}. In view of these findings, the writer concludes that sequential measurement of cerebral blood flow (CBF) after acetazolamide loading enables one to know the regional cerebral oxygen metabolic state in patients with hemodynamic ischemia, and CBF should be measured at an early stage after the administration of acetazolamide to accurately detect misery perfusion. (author)

  17. Cerebral perfusion, oxygenation and metabolism during exercise in young and elderly individuals

    Science.gov (United States)

    Fisher, James P; Hartwich, Doreen; Seifert, Thomas; Olesen, Niels D; McNulty, Clare L; Nielsen, Henning B; van Lieshout, Johannes J; Secher, Niels H

    2013-01-01

    We evaluated cerebral perfusion, oxygenation and metabolism in 11 young (22 ± 1 years) and nine older (66 ± 2 years) individuals at rest and during cycling exercise at low (25%Wmax), moderate (50%Wmax), high (75%Wmax) and exhaustive (100%Wmax) workloads. Mean middle cerebral artery blood velocity (MCA Vmean), mean arterial pressure (MAP), cardiac output (CO) and partial pressure of arterial carbon dioxide () were measured. Blood samples were obtained from the right internal jugular vein and brachial artery to determine concentration differences for oxygen (O2), glucose and lactate across the brain. The molar ratio between cerebral uptake of O2 versus carbohydrate (O2–carbohydrate index; O2/[glucose +1/2 lactate]; OCI), the cerebral metabolic rate of O2 (CMRO2) and changes in mitochondrial O2 tension () were calculated. 100%Wmax was ∼33% lower in the older group. Exercise increased MAP and CO in both groups (P exercise intensity (P exercise at ≥75%Wmax. Thus, despite the older group having reduced cerebral perfusion and maximal exercise capacity, cerebral oxygenation and uptake of lactate and glucose are similar during exercise in young and older individuals. PMID:23230234

  18. [Regional cerebral oxygen saturation as a marker of hemodynamic state following cardiac surgery].

    Science.gov (United States)

    García-Hernández, J A; Aldemira-Liz, A; Martínez-López, A I; Cayuela, A; Charlo-Molina, M T; Cano-Franco, J; Loscertales-Abril, M

    2013-10-01

    Regional cerebral oxygen saturation (rSO₂) is a measure of the general state of perfusion and oxygenation. We aim to analyze the relationship between this and various hemodynamic and respiratory parameters. Forty-three patients, operated on between October 2011 and July 2012, were included in this prospective observational descriptive study. The following parameters were measured: mean arterial pressure, both arterial and central venous oxygen saturation and partial pressures of oxygen and carbon dioxide, and lactate levels. From these parameters, the oxygenation index and the oxygen extraction ratio were calculated. These measurements were studied to evaluate whether rSO₂ correlated significantly with the other parameters. The average age and weight of the patients were 27.3 months and 9.2 kg, respectively. The rSO₂ correlated positively with both central venous oxygen saturation (r=0.73, P 0.4) between the rSO₂ and central venous oxygen saturation, and between the rSO₂ and oxygen extraction ratio. Regional cerebral oxygen saturation correlates well with hemodynamic parameters - mean arterial pressure, venous saturation, and the tissue oxygen extraction. However, it does not correlate with respiratory parameters. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  19. Calibrated histochemistry applied to oxygen supply and demand in hypertrophied rat myocardium.

    Science.gov (United States)

    Des Tombe, A L; Van Beek-Harmsen, B J; Lee-De Groot, M B E; Van Der Laarse, W J

    2002-09-01

    Oxygen supply and demand of individual cardiomyocytes during the development of myocardial hypertrophy is studied using calibrated histochemical methods. An oxygen diffusion model is used to calculate the critical extracellular oxygen tension (PO(2,crit)) required by cardiomyocytes to prevent hypoxia during hypertrophic growth, and determinants of PO(2,crit) are estimated using calibrated histochemical methods for succinate dehydrogenase activity, cardiomyocyte cross-sectional area, and myoglobin concentration. The model calculation demonstrates that it is essential to calibrate the histochemical methods, so that absolute values for the relevant parameters are obtained. The succinate dehydrogenase activity, which is proportional to the maximum rate of oxygen consumption, and the myoglobin concentration hardly change while the cardiomyocytes grow. The cross-sectional area of the cardiomyocytes, which increases up to threefold in the right ventricular wall due to pulmonary hypertension in monocrotaline-treated rats, is the most important determinant of PO(2,crit) in this model of myocardial hypertrophy. The relationship between oxygen supply and demand at the level of the cardiomyocyte can be investigated using paired determinations of spatially integrated succinate dehydrogenase activity and capillary density. Hypoxia-inducible factor 1alpha can be demonstrated by immunohistochemistry in cardiomyocytes with high PO(2,crit) and increased spatially integrated succinate dehydrogenase activity, indicating that limited oxygen supply affects gene expression in these cells. We conclude that a mismatch of oxygen supply and demand may develop during hypertrophic growth, which can play a role in the transition from myocardial hypertrophy to heart failure. Copyright 2002 Wiley-Liss, Inc.

  20. Exploring the oxygen supply and demand framework as a learning tool in undergraduate nursing education.

    Science.gov (United States)

    Gillespie, Mary; Shackell, Eileen

    2017-09-06

    In nursing education, physiological concepts are typically presented within a body 'systems' framework yet learners are often challenged to apply this knowledge in the holistic and functional manner needed for effective clinical decision-making and safe patient care. A nursing faculty addressed this learning challenge by developing an advanced organizer as a conceptual and integrative learning tool to support learners in diverse learning environments and practice settings. A mixed methods research study was conducted that explored the effectiveness of the Oxygen Supply and Demand Framework as a learning tool in undergraduate nursing education. A pretest/post-test assessment and reflective journal were used to gather data. Findings indicated the Oxygen Supply and Demand Framework guided the development of pattern recognition and thinking processes and supported knowledge development, knowledge application and clinical decision-making. The Oxygen Supply and Demand Framework supports undergraduate students learning to provide safe and effective nursing care. Copyright © 2017. Published by Elsevier Ltd.

  1. Prone position is associated with mild cerebral oxygen desaturation in elderly surgical patients.

    Directory of Open Access Journals (Sweden)

    Stacie Deiner

    Full Text Available PURPOSE: A variety of hemodynamic and respiratory alterations accompany patients in the prone position; however the effect of the prone position on intraoperative cerebral saturation has not been studied. We sought to examine whether the incidence of cerebral oxygen desaturation in elderly patients (≥68 years of age undergoing spine surgery in the prone position was more common than patients undergoing major surgery in the supine position. METHODS: We performed a retrospective cohort study of 205 patients; 63 patients underwent surgery in the prone position and 142 in the supine position. Patients were evaluated for cerebral desaturation with bilateral cerebral oximetry. The primary predictor was position, secondary were: length of the surgery, incidence and duration of cerebral desaturation episodes at several thresholds, average time of Bispectral index below threshold of 45 in minutes, average electroencephalogram suppression ratio >0, amount of blood transfused, and the incidence of hypotension and hypertension. RESULTS: Elderly spine surgery patients in the prone position were more than twice as likely to experience mild cerebral desaturation as patients in the supine position. Patients in the prone position had longer surgeries; however cerebral desaturation in the prone position was significantly more common even when adjusted for surgery time and the occurrence of intraoperative hypotension. CONCLUSION: Cerebral desaturation is related to the prone position in elderly surgery patients. Future studies are necessary to determine whether this translates to a higher incidence of postoperative cognitive dysfunction and delirium.

  2. EEG maturation and stability of cerebral oxygen extraction in very low birth weight infants.

    Science.gov (United States)

    El-Dib, M; Govindan, R; Aly, S; Mohamed, M; du Plessis, A; Aly, H

    2016-04-01

    Fractional cerebral tissue oxygen extraction (FTOE) can be continuously monitored by simultaneous near-infrared spectroscopy (NIRS) and pulse oximetry. The objective of this study is to test the hypothesis that in very low birth weight (VLBW) infants, the more mature EEG activity is, the less variable FTOE is. A prospective study was conducted on VLBW infants (transcutaneous carbon dioxide tension. Increased maturation of EEG activity is associated with decreased variability in cerebral oxygen extraction. The implications of increased variability in FTOE on brain injury in premature infants need further exploration.

  3. Cerebral perfusion, oxygenation and metabolism during exercise in young and elderly individuals

    DEFF Research Database (Denmark)

    Fisher, James P; Hartwich, Doreen; Seifert, Thomas

    2013-01-01

    artery blood velocity (MCA V(mean)), mean arterial pressure (MAP), cardiac output (CO) and the partial pressure of arterial carbon dioxide (PaCO(2)) were measured. Blood samples were obtained from the right internal jugular vein and brachial artery to determine concentration differences for oxygen (O(2......We evaluated cerebral perfusion, oxygenation, and metabolism in eleven young (age 22 ± 1 years) and nine older (age 66 ± 2 years) individuals at rest and during cycling exercise at low (25% W(max)), moderate (50% W(max)), high (75% W(ma)) and exhaustive (100% W(max)) workloads. Mean middle cerebral...

  4. Cerebral oxygen saturation and cardiac output during anaesthesia in sitting position for neurosurgical procedures: a prospective observational study.

    Science.gov (United States)

    Schramm, P; Tzanova, I; Hagen, F; Berres, M; Closhen, D; Pestel, G; Engelhard, K

    2016-10-01

    Neurosurgical operations in the dorsal cranium often require the patient to be positioned in a sitting position. This can be associated with decreased cardiac output and cerebral hypoperfusion, and possibly, inadequate cerebral oxygenation. In the present study, cerebral oxygen saturation was measured during neurosurgery in the sitting position and correlated with cardiac output. Perioperative cerebral oxygen saturation was measured continuously with two different monitors, INVOS(®) and FORE-SIGHT(®). Cardiac output was measured at eight predefined time points using transoesophageal echocardiography. Forty patients were enrolled, but only 35 (20 female) were eventually operated on in the sitting position. At the first time point, the regional cerebral oxygen saturation measured with INVOS(®) was 70 (sd 9)%; thereafter, it increased by 0.0187% min(-1) (P<0.01). The cerebral tissue oxygen saturation measured with FORE-SIGHT(®) started at 68 (sd 13)% and increased by 0.0142% min(-1) (P<0.01). The mean arterial blood pressure did not change. Cardiac output was between 6.3 (sd 1.3) and 7.2 (1.8) litre min(-1) at the predefined time points. Cardiac output, but not mean arterial blood pressure, showed a positive and significant correlation with cerebral oxygen saturation. During neurosurgery in the sitting position, the cerebral oxygen saturation slowly increases and, therefore, this position seems to be safe with regard to cerebral oxygen saturation. Cerebral oxygen saturation is stable because of constant CO and MAP, while the influence of CO on cerebral oxygen saturation seems to be more relevant. NCT01275898. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Aerobic fitness influences cerebral oxygenation response to maximal exercise in healthy subjects.

    Science.gov (United States)

    Oussaidene, Kahina; Prieur, Fabrice; Tagougui, Semah; Abaidia, Abdelbasset; Matran, Regis; Mucci, Patrick

    2015-01-01

    The study examined whether the aerobic fitness level modifies the cerebral oxygenation response to incremental ramp exercise, and more specifically the decline in cerebral oxygenation from heavy exercise up to maximal intensities. 11 untrained (VO2max 47.3±4.0 mL min(-1) kg(-1)) and 13 endurance-trained (VO2max 61.2±8.0 mL min(-1) kg(-1)) healthy men performed a maximal ramp cycle exercise. Left prefrontal cortex oxygenation (ΔHbO2) was monitored by near-infrared spectroscopy. A cerebral oxygenation threshold decline (ThCOx) during exercise was determined. ThCox occurred in all subjects but for higher VO2 (mL min(-1) kg(-1)) in endurance-trained than in untrained subjects (Pexercise intensity corresponding to ThCOx, ΔHbO2 was higher in endurance-trained than in untrained subjects (Pexercise intensities in endurance-trained in relation with their higher VO2max than untrained men. These results demonstrated that aerobic fitness influences cerebral oxygenation during exercise.

  6. Cerebral oxygenation and haemodynamic effects induced by nimodipine in healthy subjects.

    Science.gov (United States)

    Canova, Daniela; Roatta, Silvestro; Micieli, Giuseppe; Bosone, Daniele

    2012-01-01

    The cerebrovascular effects of nimodipine are still poorly understood even in the healthy condition; in particular, its effects on tissue oxygenation have never been investigated. The aim of the present study was to investigate changes in cerebral oxygenation and blood volume upon oral administration of nimodipine (90 mg) in the healthy condition. In eight subjects, changes in cerebral tissue oxygenation and blood volume were determined simultaneously with changes in blood velocity of the middle cerebral artery (VMCA) by using, respectively, near infrared spectroscopy (NIRS) and transcranial Doppler ultrasonography (TCD). The subjects also underwent noninvasive assessment of arterial blood pressure (ABP) and end-tidal CO2. TCD and NIRS CO2 reactivity indices were al-so extracted. Nimodipine significantly reduced ABP (11±13%) and increased heart rate, as well as NIRS oxygenation(6.0±4.8%) and blood volume indices (9.4±10.1%), while V(MCA) was not significantly decreased (2.0±3.5%). Nimodipine slightly but significantly reduced the V(MCA) response to changes in pCO2 whereas the CO2 reactivity of NIRS parameters was improved. The observed changes in cerebral tissue oxygenation and blood volume indicate nimodipine-induced cerebrovascular dilation and increased perfusion, while the effect on V(MCA)possibly results from dilation of the insonated artery. The present results cast doubt on the putative nimodipine-induced impairment of CO2 reactivity.

  7. Photoacoustic microscopy of cerebral hemodynamic and oxygen-metabolic responses to anesthetics

    Science.gov (United States)

    Cao, Rui; Li, Jun; Ning, Bo; Sun, Naidi; Wang, Tianxiong; Zuo, Zhiyi; Hu, Song

    2017-02-01

    General anesthetics are known to have profound effects on cerebral hemodynamics and neuronal activities. However, it remains a challenge to directly assess anesthetics-induced hemodynamic and oxygen-metabolic changes from the true baseline under wakefulness at the microscopic level, due to the lack of an enabling technology for high-resolution functional imaging of the awake mouse brain. To address this challenge, we have developed head-restrained photoacoustic microscopy (PAM), which enables simultaneous imaging of the cerebrovascular anatomy, total concentration and oxygen saturation of hemoglobin (CHb and sO2), and blood flow in awake mice. From these hemodynamic measurements, two important metabolic parameters, oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO2), can be derived. Side-by-side comparison of the mouse brain under wakefulness and anesthesia revealed multifaceted cerebral responses to isoflurane, a volatile anesthetic widely used in preclinical research and clinical practice. Key observations include elevated cerebral blood flow (CBF) and reduced oxygen extraction and metabolism.

  8. Physiological meaning of cerebral oxygen saturation for piglet with hypoxia-ischemia

    Science.gov (United States)

    Ding, Haishu; Huang, Lan; Jen, Chungchien; Hwang, Betau; Lee, Zhiguang; Teng, Yichao; Zheng, Meizhi

    2005-01-01

    The physiological meaning of cerebral oxygen saturation absolute values and the oxygen metabolism of piglet with hypoxia-ischemia (HIE) were researched. The subjects were two piglets. During the total experiment of hypoxia then recovery, the regional cerebral tissue oxygen (rScO2), pulse oxygen saturation (SpO2) were detected non-invasively and the jugular oxygen saturation (SjO2), arterial oxygen saturation (SaO2) were given invasively. The results show that because SjO2 was equal to or larger than rScO2 and SaO2 > ScO2, rScO2 cannot be determined by the weighted sum of SjO2 and SaO2 which had been presented in some papers. According to above-mentioned analysis, the ecchymoma and pathological changes of the vessels due to HIE may be another contribution of rScO2. SjO2 was correlated with SaO2 (R=0.996 and 0.962 for two piglets) and the values of (SaO2-SjO2) are close to constants (29.3+/-8% and 30.3+/-8%).It means that because the subjects were under anesthesia, the oxygen consumption of cerebral tissue kept constants.

  9. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

    Directory of Open Access Journals (Sweden)

    AK Gregg

    2013-07-01

    Full Text Available Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD optodes were used to quantify the change in oxygen concentrations of microbial communities following exposure to exudates generated by turf algae and crustose coralline algae (CCA. BOD optodes were embedded with microbial communities cultured from Montastraea annularis and Mussismilia hispida, and respiration was measured during exposure to turf and CCA exudates. The oxygen concentrations along the optodes were visualized with a low-cost Submersible Oxygen Optode Recorder (SOOpR system. With this system we observed that exposure to exudates derived from turf algae stimulated higher oxygen drawdown by the coral-associated bacteria than CCA exudates or seawater controls. Furthermore, in both turf and CCA exudate treatments, all microbial communities (coral-, algae-associated and pelagic contributed significantly to the observed oxygen drawdown. This suggests that the driving factor for elevated oxygen consumption rates is the source of exudates rather than the initially introduced microbial community. Our results demonstrate that exudates from turf algae may contribute to hypoxia-induced coral stress in two different coral genera as a result of increased biological oxygen demand of the local microbial community. Additionally, the SOOpR system developed here can be applied to measure the BOD of any culturable microbe or microbial community.

  10. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates.

    Science.gov (United States)

    Gregg, Ak; Hatay, M; Haas, Af; Robinett, Nl; Barott, K; Vermeij, Mja; Marhaver, Kl; Meirelles, P; Thompson, F; Rohwer, F

    2013-01-01

    Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD) optodes were used to quantify the change in oxygen concentrations of microbial communities following exposure to exudates generated by turf algae and crustose coralline algae (CCA). BOD optodes were embedded with microbial communities cultured from Montastraea annularis and Mussismilia hispida, and respiration was measured during exposure to turf and CCA exudates. The oxygen concentrations along the optodes were visualized with a low-cost Submersible Oxygen Optode Recorder (SOOpR) system. With this system we observed that exposure to exudates derived from turf algae stimulated higher oxygen drawdown by the coral-associated bacteria than CCA exudates or seawater controls. Furthermore, in both turf and CCA exudate treatments, all microbial communities (coral-, algae-associated and pelagic) contributed significantly to the observed oxygen drawdown. This suggests that the driving factor for elevated oxygen consumption rates is the source of exudates rather than the initially introduced microbial community. Our results demonstrate that exudates from turf algae may contribute to hypoxia-induced coral stress in two different coral genera as a result of increased biological oxygen demand of the local microbial community. Additionally, the SOOpR system developed here can be applied to measure the BOD of any culturable microbe or microbial community.

  11. The evaluation of cerebral oxygenation by oximetry in patients with ischaemic stroke.

    Directory of Open Access Journals (Sweden)

    Demet G

    2000-04-01

    Full Text Available AIMS: To evaluate the clinical significance of estimation of the regional cerebral oxygen saturation (rSO2 in the patients with ischaemic stroke by the cerebral oximetry during acute, sub-acute and chronic phases. SUBJECTS AND METHODS: In this prospective study, 24 patients with ischaemic stroke in the middle cerebral artery territory were included. A detailed clinical examination and appropriate laboratory investigations were carried out. The rSO2 was determined by oximetery (INVOS 3100-SD bilaterally on the first, third, seventh, and fifteenth days. The blood pressure, the peripheral capillary oxygen saturation and the arterial blood gas values were noted too. the changes were evaluated along with Glasgow coma scale (GCS using unpaired student t-test and one way ANOVA test. RESULTS: There were significant differences between the rSO2 values in acute, subacute and chronic phases on the side of the lesion (p value < 0.05. The values of oxygen saturation gradually increased throughout the chronic phase. These values showed a positive correlation with GCS, but the results were not significant statistically. The rSO2 values were also significantly higher on the non-lesional side than those on the lesion side in the acute phase (p= 0.0034, the discrepancy disappeared during the sub-acute and chronic phases. CONCLUSION: Cerebral oximetry can be used as a measure to evaluate the cerebral oxygenation during the various phases of ischaemic stroke. It has a potential to serve as a useful marker for detection of cerebral oxygenation imbalances, to judge the effectiveness of the management and for the follow-up of patients with ischaemic stroke.

  12. Reduction in Cerebral Oxygenation due to Patent Ductus Arteriosus Is Pronounced in Small-for-Gestational-Age Neonates

    NARCIS (Netherlands)

    Cohen, Emily; Dix, Laura; Baerts, Willem; Alderliesten, Thomas; Lemmers, Petra; van Bel, Frank

    2016-01-01

    BACKGROUND: A haemodynamically significant patent ductus arteriosus (hsPDA) reduces cerebral oxygenation in appropriate-for-gestational-age (AGA) preterm neonates. Reduced cerebral oxygenation has been associated with brain injury. Preterm small-for-gestational-age (SGA) neonates show higher cerebra

  13. T2’-Imaging to Assess Cerebral Oxygen Extraction Fraction in Carotid Occlusive Disease: Influence of Cerebral Autoregulation and Cerebral Blood Volume

    Science.gov (United States)

    Deichmann, Ralf; Pfeilschifter, Waltraud; Hattingen, Elke; Singer, Oliver C.; Wagner, Marlies

    2016-01-01

    Purpose Quantitative T2'-mapping detects regional changes of the relation of oxygenated and deoxygenated hemoglobin (Hb) by using their different magnetic properties in gradient echo imaging and might therefore be a surrogate marker of increased oxygen extraction fraction (OEF) in cerebral hypoperfusion. Since elevations of cerebral blood volume (CBV) with consecutive accumulation of Hb might also increase the fraction of deoxygenated Hb and, through this, decrease the T2’-values in these patients we evaluated the relationship between T2’-values and CBV in patients with unilateral high-grade large-artery stenosis. Materials and Methods Data from 16 patients (13 male, 3 female; mean age 53 years) with unilateral symptomatic or asymptomatic high-grade internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis/occlusion were analyzed. MRI included perfusion-weighted imaging and high-resolution T2’-mapping. Representative relative (r)CBV-values were analyzed in areas of decreased T2’ with different degrees of perfusion delay and compared to corresponding contralateral areas. Results No significant elevations in cerebral rCBV were detected within areas with significantly decreased T2’-values. In contrast, rCBV was significantly decreased (pperfusion delay and decreased T2’. Furthermore, no significant correlation between T2’- and rCBV-values was found. Conclusions rCBV is not significantly increased in areas of decreased T2’ and in areas of restricted perfusion in patients with unilateral high-grade stenosis. Therefore, T2’ should only be influenced by changes of oxygen metabolism, regarding our patient collective especially by an increase of the OEF. T2’-mapping is suitable to detect altered oxygen consumption in chronic cerebrovascular disease. PMID:27560515

  14. Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Makoto; Ichiya, Yuici; Kuwabara, Yasuo (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine) (and others)

    1989-11-01

    Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometablolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP. (author).

  15. Effects of midazolam and morphine on cerebral oxygenation and hemodynamics in ventilated premature infants.

    NARCIS (Netherlands)

    Velden, A.A.E.M. van der; Hopman, J.C.W.; Klaessens, J.H.G.M.; Feuth, A.B.; Sengers, R.C.A.; Liem, K.D.

    2006-01-01

    BACKGROUND: Midazolam sedation and morphine analgesia are commonly used in ventilated premature infants. OBJECTIVES: To evaluate the effects of midazolam versus morphine infusion on cerebral oxygenation and hemodynamics in ventilated premature infants. METHODS: 11 patients (GA 26.6-33.0 weeks, BW 78

  16. Precision of measurement of cerebral tissue oxygenation index using near-infrared spectroscopy in preterm neonates

    DEFF Research Database (Denmark)

    Sorensen, Line C; Greisen, Gorm

    2006-01-01

    The use of cerebral tissue oxygenation index (c-TOI) in a clinical setting is limited by doubts concerning the accuracy of the measurements. Since there is no gold standard, validation is difficult. Our modest aim was to quantify the precision of c-TOI doing repeated measurements by reapplying th...

  17. Systematic review of near-infrared spectroscopy determined cerebral oxygenation during non-cardiac surgery

    DEFF Research Database (Denmark)

    Nielsen, Henning B

    2014-01-01

    Near-infrared spectroscopy (NIRS) is used to monitor regional cerebral oxygenation (rScO2) during cardiac surgery but is less established during non-cardiac surgery. This systematic review aimed (i) to determine the non-cardiac surgical procedures that provoke a reduction in rScO2 and (ii...

  18. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

    NARCIS (Netherlands)

    Gregg, A.K.; Hatay, M.; Haas, A.F.; Robinett, N.L.; Barott, K.; Vermeij, M.J.A.; Marhaver, K.; Thompson, F.; Meirelles, P.; Rohwer, F.

    2013-01-01

    Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD) optodes were used to quantify the change

  19. Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates

    NARCIS (Netherlands)

    Gregg, A.K.; Hatay, M.; Haas, A.F.; Robinett, N.L.; Barott, K.; Vermeij, M.J.A.; Marhaver, K.; Thompson, F.; Meirelles, P.; Rohwer, F.

    2013-01-01

    Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen demand (BOD) optodes were used to quantify the change i

  20. Ultimate biochemical oxygen demand in semi-intensively managed shrimp pond waters

    Science.gov (United States)

    Three independent studies were conducted to quantified ultimate biochemical oxygen demand (UBOD) and the corresponding decomposition rate constant for production pond (average 21.5 ha each) waters and effluents on six semi-intensively managed marine shrimp (Litopenaeus vannamei) farms in Honduras. S...

  1. Transcranial regional cerebral oxygen desaturation predicts delayed cerebral ischaemia and poor outcomes after subarachnoid haemorrhage: a correlational study.

    Science.gov (United States)

    Yousef, Khalil M; Balzer, Jeffrey R; Crago, Elizabeth A; Poloyac, Samuel M; Sherwood, Paula R

    2014-12-01

    To examine the relationship between regional cerebral oxygen saturation (rSO2), delayed cerebral ischaemia (DCI), and outcomes after aneurysmal subarachnoid haemorrhage (aSAH). Subjects (n = 163) with aSAH, age 21-75 years, and Fisher grade >1 were included in the study. Continuous rSO2 monitoring was performed for 5-10 days after injury using near-infrared spectroscopy with sensors over the frontal/temporal cortex. rSO250 (OR 3.25, 95%CI 1.58-6.69), positive predictive value (PPV) = 70%. Subjects with rSO2 50 (OR 2.7, 95%CI 1.1-7.2), PPV = 70%. These results suggest that NIRS has the potential for detecting DCI after aSAH. This potential needs to be further explored in a larger prospective study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Acute cocoa flavanol improves cerebral oxygenation without enhancing executive function at rest or after exercise.

    Science.gov (United States)

    Decroix, Lieselot; Tonoli, Cajsa; Soares, Danusa D; Tagougui, Semah; Heyman, Elsa; Meeusen, Romain

    2016-12-01

    Acute exercise-induced improvements in cognitive function are accompanied by increased (cerebral) blood flow and increased brain-derived neurotrophic factor (BDNF) levels. Acute cocoa flavanol (CF) intake may improve cognitive function, cerebral blood flow (in humans), and BNDF levels (in animals). This study investigated (i) the effect of CF intake in combination with exercise on cognitive function and (ii) cerebral hemodynamics and BDNF in response to CF intake and exercise. Twelve healthy men participated in this randomized, double-blind, crossover study. Participants performed a cognitive task (CT) at 100 min after acute 903-mg CF or placebo (PL) intake, followed by a 30-min time-trial. Immediately after this exercise, the same CT was performed. Prefrontal near-infrared spectroscopy was applied during CT and exercise to measure changes in oxygenated (ΔHbO2), deoxygenated (ΔHHb), and total haemoglobin (ΔHbtot) and blood samples were drawn and analyzed for BDNF. Reaction time was faster postexercise, but was not influenced by CF. ΔHbO2 during the resting CT was increased by CF, compared with PL. ΔHbO2, ΔHHb, and ΔHbtot increased in response to exercise without any effect of CF. During the postexercise cognitive task, there were no hemodynamic differences between CF or PL. Serum BDNF was increased by exercise, but was not influenced by CF. In conclusion, at rest, CF intake increased cerebral oxygenation, but not BDNF concentrations, and no impact on executive function was detected. This beneficial effect of CF on cerebral oxygenation at rest was overruled by the strong exercise-induced increases in cerebral perfusion and oxygenation.

  3. Phenobarbital and neonatal seizures affect cerebral oxygen metabolism: a near-infrared spectroscopy study.

    Science.gov (United States)

    Sokoloff, Max D; Plegue, Melissa A; Chervin, Ronald D; Barks, John D E; Shellhaas, Renée A

    2015-07-01

    Near-infrared spectroscopy (NIRS) measures oxygen metabolism and is increasingly used for monitoring critically ill neonates. The implications of NIRS-recorded data in this population are poorly understood. We evaluated NIRS monitoring for neonates with seizures. In neonates monitored with video-electroencephalography, NIRS-measured cerebral regional oxygen saturation (rSO2) and systemic O2 saturation were recorded every 5 s. Mean rSO2 was extracted for 1-h blocks before, during, and after phenobarbital doses. For each electrographic seizure, mean rSO2 was extracted for a period of three times the duration of the seizure before and after the ictal pattern, as well as during the seizure. Linear mixed models were developed to assess the impact of phenobarbital administration and of seizures on rSO2 and fractional tissue oxygen extraction. For 20 neonates (estimated gestational age: 39.6 ± 1.5 wk), 61 phenobarbital doses and 40 seizures were analyzed. Cerebral rSO2 rose (P = 0.005), and fractional tissue oxygen extraction declined (P = 0.018) with increasing phenobarbital doses. rSO2 declined during seizures, compared with baseline and postictal phases (baseline 81.2 vs. ictal 77.7 vs. postictal 79.4; P = 0.004). Fractional tissue oxygen extraction was highest during seizures (P = 0.002). Cerebral oxygen metabolism decreases after phenobarbital administration and increases during seizures. These small, but clear, changes in cerebral oxygen metabolism merit assessment for potential clinical impact.

  4. Hepatic encephalopathy is associated with decreased cerebral oxygen metabolism and blood flow, not increased ammonia uptake

    DEFF Research Database (Denmark)

    Dam, Gitte; Keiding, Susanne; Munk, Ole L

    2013-01-01

    Studies have shown decreased cerebral oxygen metabolism (CMRO(2)) and blood flow (CBF) in patients with cirrhosis with hepatic encephalopathy (HE). It remains unclear, however, whether these disturbances are associated with HE or with cirrhosis itself and how they may relate to arterial blood...... ammonia concentration and cerebral metabolic rate of blood ammonia (CMRA). We addressed these questions in a paired study design by investigating patients with cirrhosis during and after recovery from an acute episode of HE type C. CMRO(2), CBF, and CMRA were measured by dynamic positron emission...

  5. Influence of intranasal and carotid cooling on cerebral temperature balance and oxygenation

    Directory of Open Access Journals (Sweden)

    Lars eNybo

    2014-02-01

    Full Text Available The present study evaluated the influence of intranasal cooling with balloon catheters, increased nasal ventilation, or percutaneous cooling of the carotid arteries on cerebral temperature balance and oxygenation in six healthy male subjects. Aortic arch and internal jugular venous blood temperatures were measured to assess the cerebral heat balance and corresponding paired blood samples were obtained to evaluate cerebral metabolism and oxygenation at rest, following 60 min of intranasal cooling, 5 min of nasal ventilation, and 15 min with carotid cooling. Intranasal cooling induced a parallel drop in jugular venous and arterial blood temperatures by 0.30 ± 0.08 ºC (mean ± SD, whereas nasal ventilation and carotid cooling failed to lower the jugular venous blood temperature. The magnitude of the arterio-venous temperature difference across the brain remained unchanged at - 0.33 ± 0.05 ºC following intranasal and carotid cooling, but increased to - 0.44 ± 0.11 ºC (P< 0.05 following nasal ventilation. Calculated cerebral capillary oxygen tension was 43 ± 3 mmHg at rest and remained unchanged during intranasal and carotid cooling, but decreased to 38 ± 2 mmHg (P< 0.05 following increased nasal ventilation. In conclusion, percutaneous cooling of the carotid arteries and intranasal cooling with balloon catheters are insufficient to influence cerebral oxygenation in normothermic subjects as the cooling rate is only 0.3 ºC per hour and neither intranasal nor carotid cooling is capable of inducing selective brain cooling.

  6. Cerebral oxygenation is reduced during hyperthermic exercise in humans

    DEFF Research Database (Denmark)

    Rasmussen, P.; Nybo, Lars; Volianitis, Stefanos

    2010-01-01

    was reduced by 15 +/- 13% (P stress, RPE increased to 19 (19-20; P correlated inversely with P(mito)O(2) (r(2) = 0.42, P ... (CBF). Heat stress challenges exercise capacity as expressed by increased rating of perceived exertion (RPE). Methods: This study evaluated the effect of heat stress during exercise on P(mito)O(2) calculated based on a Kety-Schmidt-determined CBF and the arterial-to-jugular venous oxygen differences...

  7. Breakpoints in Ventilation, Cerebral and Muscle Oxygenation, and Muscle Activity During an Incremental Cycling Exercise

    Directory of Open Access Journals (Sweden)

    Sebastien eRacinais

    2014-04-01

    Full Text Available The aim of this study was to locate the breakpoints of cerebral and muscle oxygenation and muscle electrical activity during a ramp exercise in reference to the first and second ventilatory thresholds. Twenty-five cyclists completed a maximal ramp test on an electromagnetically braked cycle-ergometer with a rate of increment of 25W/min. Expired gazes (breath-by-breath, prefrontal cortex and vastus lateralis (VL oxygenation (Near-infrared spectroscopy together with electromyographic Root Mean Square activity for the VL, rectus femoris (RF and biceps femoris (BF muscles were continuously assessed. There was a non-linear increase in both cerebral deoxyhemoglobin (at 56±13% of the exercise and oxyhemoglobin (56±8% of exercise concomitantly to the first ventilatory threshold (57±6% of exercise, p>0.86, Cohen’s d0.8. We identified one threshold only for muscle parameters with a non-linear decrease in muscle oxyhemoglobin (78±9% of exercise, attenuation in muscle deoxyhemoglobin (80±8% of exercise, and increase in electromyographic activity of VL (89±5 % of exercise, RF (82±14 % of exercise and BF (85±9 % of exercise. While the thresholds in muscle oxygenation and RF electromyographic activity were contemporary to V-T2 (d0.6. Our results suggest that the metabolic and ventilatory events characterizing this latter cardiopulmonary threshold may affect both cerebral and muscle oxygenation levels, and in turn, muscle recruitment responses.

  8. Noninvasive cerebral blood oxygenation monitoring: clinical test of multiwavelength optoacoustic system

    Science.gov (United States)

    Petrov, Y. Y.; Prough, D. S.; Petrova, I.; Patrikeev, I. A.; Cicenaite, I.; Esenaliev, R. O.

    2007-02-01

    Continuous monitoring of cerebral blood oxygenation is critically important for treatment of patients with life-threatening conditions like severe brain injury or during cardiac surgery. We designed and built a novel multiwavelength optoacoustic system for noninvasive, continuous, and accurate monitoring of cerebral blood oxygenation. We use an Optical Parametric Oscillator as a light source. We successfully tested the system in vitro as well as in vivo in large animals (sheep) through thick tissues overlying blood vessels which drain venous blood out of the brain (e.g., superior sagittal sinus or jugular vein). Here we present the results of clinical tests of the system for continuous noninvasive cerebral blood oxygenation monitoring in the internal jugular vein of healthy volunteers. We applied our custom-built optoacoustic probe (which incorporated a wide-band acoustic transducer and an optical fiber) to the neck area overlying the internal jugular vein. We performed measurements with volunteers at 18 wavelengths in the near-infrared spectral range. Despite a thick layer of overlying connective tissue and low energy used in the experiments, we recorded signals with high signal-to-noise ratios for all volunteers. We found that the temporal (independent of signal amplitude) parameters of recorded profiles for different levels of blood oxygenation correlated well with the spectrum of effective attenuation coefficients of blood.

  9. The role of blood flow distribution in the regulation of cerebral oxygen availability in fetal growth restriction.

    Science.gov (United States)

    Luria, Oded; Bar, Jacob; Kovo, Michal; Malinger, Gustavo; Golan, Abraham; Barnea, Ofer

    2012-04-01

    Fetal growth restriction (FGR) elicits hemodynamic compensatory mechanisms in the fetal circulation. These mechanisms are complex and their effect on the cerebral oxygen availability is not fully understood. To quantify the contribution of each compensatory mechanism to the fetal cerebral oxygen availability, a mathematical model of the fetal circulation was developed. The model was based on cardiac-output distribution in the fetal circulation. The compensatory mechanisms of FGR were simulated and their effects on cerebral oxygen availability were analyzed. The mathematical analysis included the effects of cerebral vasodilation, placental resistance to blood flow, degree of blood shunting by the ductus venosus and the effect of maternal-originated placental insufficiency. The model indicated a unimodal dependency between placental blood flow and cerebral oxygen availability. Optimal cerebral oxygen availability was achieved when the placental blood flow was mildly reduced compared to the normal flow. This optimal ratio was found to increase as the hypoxic state of FGR worsens. The model indicated that cerebral oxygen availability is increasingly dependent on the cardiac output distribution as the fetus gains weight. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

  10. Correlation of brain tissue oxygen tension with cerebral near-infrared spectroscopy and mixed venous oxygen saturation during extracorporeal membrane oxygenation.

    Science.gov (United States)

    Tyree, Kreangkai; Tyree, Melissa; DiGeronimo, Robert

    2009-09-01

    The aim of this prospective, animal study was to compare brain tissue oxygen tension (PbtO(2)) with cerebral near infrared spectroscopy (NIRS) and mixed venous oxygen saturation (SVO(2)) during venoarterial extracorporeal membrane oxygenation (VA ECMO) in a porcine model. This was accomplished using twelve immature piglets with surgically implanted catheters placed in the superficial cerebral cortex to measure brain PbtO(2) and microdialysis metabolites. The NIRS sensor was placed overlying the forehead to measure cerebral regional saturation index (rSO(2)i) while SVO(2) was measured directly from the ECMO circuit. Animals were placed on VA ECMO followed by an initial period of stabilization, after which they were subjected to graded hypoxia and recovery. Our results revealed that rSO(2)i and SVO(2) correlated only marginally with PbtO(2) (R(2)=0.32 and R(2)=0.26, respectively) while the correlation between rSO(2)i and SVO( 2) was significantly stronger (R(2)=0.59). Cerebral metabolites and rSO(2)i were significantly altered during attenuation of PbtO( 2), p<0.05). A subset of animals, following exposure to hypoxia, experienced markedly delayed recovery of both rSO(2)i and PbtO( 2) despite rapid normalization of SVO(2). Upon further analysis, these animals had significantly lower blood pressure (p=0.001), lower serum pH (p=0.01), and higher serum lactate (p=0.02). Additionally, in this subgroup, rSO(2)i correlated better with PbtO(2) (R(2)=0.76). These findings suggest that, in our ECMO model, rSO(2)i and SVO( 2) correlate reasonably well with each other, but not necessarily with brain PbtO(2) and that NIRS-derived rSO(2)i may more accurately reflect cerebral tissue hypoxia in sicker animals.

  11. Formulations for aircraft and airfield deicing and anti-icing: aquatic toxicity and biochemical oxygen demand

    Science.gov (United States)

    Ferguson, Lee; Corsi, Steven R.; Geis, Steven W.; Anderson, Graham; Joback, Kevin; Gold, Harris; Mericas, Dean; Cancilla, Devon A.

    2008-01-01

    The Airport Cooperative Research Program (ACRP) has sponsored research on environmental characteristics of aircraft and pavement deicers and anti-icers focusing primarily on biochemical oxygen demand (BOD) and aquatic toxicity of formulated products and individual chemical components of formulations. This report presents a background of issues leading to this research, objectives of this document, and a description of the efforts and findings of this research.

  12. Systematic review of near-infrared spectroscopy determined cerebral oxygenation during non-cardiac surgery

    Directory of Open Access Journals (Sweden)

    Henning Bay Nielsen

    2014-03-01

    Full Text Available Near-infrared spectroscopy (NIRS is used to monitor regional cerebral oxygenation (rScO2 during cardiac surgery but is less established during non-cardiac surgery. This systematic review aimed i to determine the non-cardiac surgical procedures that provoke a reduction in rScO2 and ii to evaluate whether an intraoperative reduction in rScO2 influences postoperative outcome. The PubMed and Embase database were searched from inception until April 30, 2013 and inclusion criteria were intraoperative NIRS determined rScO2 in adult patients undergoing non-cardiac surgery. The type of surgery and number of patients included were recorded. There was included 113 articles and evidence suggests that rScO2 is reduced during thoracic surgery involving single lung ventilation, major abdominal surgery, hip surgery, and laparascopic surgery with the patient placed in anti-Tredelenburg’s position. Shoulder arthroscopy in the beach chair and carotid endarterectomy with clamped internal carotid artery also cause pronounced cerebral desaturation. A >20% reduction in rScO2 coincides with indices of regional and global cerebral ischemia during carotid endarterectomy. Following thoracic surgery, major orthopedic and abdominal surgery the occurrence of postoperative cognitive dysfunction might be related to intraoperative cerebral desaturation. In conclusion, certain non-cardiac surgical procedures is associated with an increased risk for the occurrence of regional cerebral oxygenation. Evidence for an association between cerebral desaturation and postoperative outcome parameters other than cognitive dysfunction needs to be established.

  13. New Molecular Knowledge Towards the Trigemino-Cardiac Reflex as a Cerebral Oxygen-Conserving Reflex

    Directory of Open Access Journals (Sweden)

    N. Sandu

    2010-01-01

    Full Text Available The trigemino-cardiac reflex (TCR represents the most powerful of the autonomous reflexes and is a subphenomenon in the group of the so-called “oxygen-conserving reflexes”. Within seconds after the initiation of such a reflex, there is a powerful and differentiated activation of the sympathetic system with subsequent elevation in regional cerebral blood flow (CBF, with no changes in the cerebral metabolic rate of oxygen (CMRO2 or in the cerebral metabolic rate of glucose (CMRglc. Such an increase in regional CBF without a change of CMRO2 or CMRglc provides the brain with oxygen rapidly and efficiently. Features of the reflex have been discovered during skull base surgery, mediating reflex protection projects via currently undefined pathways from the rostral ventrolateral medulla oblongata to the upper brainstem and/or thalamus, which finally engage a small population of neurons in the cortex. This cortical center appears to be dedicated to transduce a neuronal signal reflexively into cerebral vasodilatation and synchronization of electrocortical activity; a fact that seems to be unique among autonomous reflexes. Sympathetic excitation is mediated by cortical-spinal projection to spinal preganglionic sympathetic neurons, whereas bradycardia is mediated via projections to cardiovagal motor medullary neurons. The integrated reflex response serves to redistribute blood from viscera to the brain in response to a challenge to cerebral metabolism, but seems also to initiate a preconditioning mechanism. Previous studies showed a great variability in the human TCR response, in special to external stimuli and individual factors. The TCR gives, therefore, not only new insights into novel therapeutic options for a range of disorders characterized by neuronal death, but also into the cortical and molecular organization of the brain.

  14. New molecular knowledge towards the trigemino-cardiac reflex as a cerebral oxygen-conserving reflex.

    Science.gov (United States)

    Sandu, N; Spiriev, T; Lemaitre, F; Filis, A; Schaller, B

    2010-05-04

    The trigemino-cardiac reflex (TCR) represents the most powerful of the autonomous reflexes and is a subphenomenon in the group of the so-called "oxygen-conserving reflexes". Within seconds after the initiation of such a reflex, there is a powerful and differentiated activation of the sympathetic system with subsequent elevation in regional cerebral blood flow (CBF), with no changes in the cerebral metabolic rate of oxygen (CMRO2) or in the cerebral metabolic rate of glucose (CMRglc). Such an increase in regional CBF without a change of CMRO2 or CMRglc provides the brain with oxygen rapidly and efficiently. Features of the reflex have been discovered during skull base surgery, mediating reflex protection projects via currently undefined pathways from the rostral ventrolateral medulla oblongata to the upper brainstem and/or thalamus, which finally engage a small population of neurons in the cortex. This cortical center appears to be dedicated to transduce a neuronal signal reflexively into cerebral vasodilatation and synchronization of electrocortical activity; a fact that seems to be unique among autonomous reflexes. Sympathetic excitation is mediated by cortical-spinal projection to spinal preganglionic sympathetic neurons, whereas bradycardia is mediated via projections to cardiovagal motor medullary neurons. The integrated reflex response serves to redistribute blood from viscera to the brain in response to a challenge to cerebral metabolism, but seems also to initiate a preconditioning mechanism. Previous studies showed a great variability in the human TCR response, in special to external stimuli and individual factors. The TCR gives, therefore, not only new insights into novel therapeutic options for a range of disorders characterized by neuronal death, but also into the cortical and molecular organization of the brain.

  15. PET imaging of cerebral perfusion and oxygen metabolism in stroke

    Energy Technology Data Exchange (ETDEWEB)

    Pointon, O.; Yasaka, M.; Berlangieri, S.U.; Newton, M.R.; Thomas, D.L.; Chan, C.G.; Egan, G.F.; Tochon-Danguy, H.J.; O``Keefe, G.; Donnan, G.A.; McKay, W.J. [Austin Hospital, Melbourne, VIC (Australia). Centre for PET and Depts of Nuclear Medicine and Neurology

    1998-03-01

    Full text: Stroke remains a devastating clinical event with few therapeutic options. In patients with acute stroke, we studied the cerebral perfusion and metabolic patterns with {sup 15}O-CO{sub 2} or H{sub 2}O and {sup 15}O-O{sub 2} positron emission tomography and correlated these findings to the clinical background. Forty three patients underwent 45 studies 0-23 days post-stroke (mean 7 days). Fifteen patients showed luxury perfusion (Group A), 10 had matched low perfusion and metabolism (B) and 3 showed mixed pattern including an area of misery perfusion (C). Seventeen showed no relevant abnormality (D) and there were no examples of isolated misery perfusion. Twelve of the 15 in Group A had either haemorrhagic transformation on CT, re-opening on angiography, or a cardioembolic mechanism. In contrast only 5/10 in Group B, 0/3 in Group C and 2/17 in Group D had these features. Although 7/10 in group B had moderate or large size infarcts on CT the incidence of haemorrhagic transformation was low (2/10) and significant carotid stenoses were more common in those studied (5/8) compared with the other groups. Misery perfusion was not seen beyond five days. Thus, luxury perfusion seems to be related to a cardio-embolic mechanism or reperfusion. Matched low perfusion and metabolism was associated with a low rate of haemorrhagic transformation despite a high incidence of moderate to large size infarcts. Misery perfusion is an early phenomenon in the evolution of ischaemic stroke.

  16. Cerebral regional oxygen saturation monitoring in pediatric malfunctioning shunt patients☆,☆☆,★

    Science.gov (United States)

    Abramo, Thomas J.; Zhou, Chuan; Estrada, Cristina; Drayna, Patrick C.; Locklair, Matthew R.; Miller, Renee; Pearson, Matthew; Tulipan, Noel; Arnold, Donald H.

    2014-01-01

    Background Shunt malfunction produces increased intracranial pressure causing decreased cerebral regional perfusion and tissue O2sat. Cerebral regional oxygen saturation (rSO2) by near-infrared spectroscopy represents tissue perfusion and oxygen saturation. Cerebral rSO2 is used to detect cerebral ischemia in pediatric clinical settings. Objective The objective of the study was to determine the reliability of cerebral rSO2 in pediatric malfunctioning shunt. Methods A prospective observational study of pediatric patients presented to the pediatric emergency department was conducted. Confirmed malfunctioning shunt subjects had cerebral rSO2 monitoring. Results A total of 131 malfunctioning shunt subjects had cerebral rSO2 monitoring. Patient's central trend and intrasubject variability of cerebral rSO2 readings for left and right probe and malfunction sites (n = 131) are as follows: VariableOverall, mean SO2Distal, mean SO2Proximal, mean rSO2PLeft cerebral rSO2 trend69.1 (10.7)67.7 (9.81)70.0 (11.17).23Right cerebral rSO2 trend71.3 (9.6)70.5 (8.13)71.8 (10.40).42Left cerebral rSO2 variability3.57 (2.04)4.72 (2.55)2.88 (1.24)<.001Right cerebral rSO2 variability3.46 (1.95)3.77 (2.20)3.28 (1.77).19 Intrasubject left and right rSO2 Pearson correlation was −0.46 to 0.98 (mean ± SD, 0.35 ± 0.34; median, 0.34; interquartile range, 0.06–0.61). The correlation coefficients of 99 subjects between left and right rSO2 was significantly different (P < .001), suggesting that intrasubjects' left and right rSO2 are highly correlated. Sample mean difference between left and right rSO2 were −1.7% (95% confidence interval [CI], −1.8 to −1.6; P < .001) supporting overall left lower than right. Intraclass correlation for left rSO2 was 87.4% (95% CI, 87.2%−87.6%), and that for right rSO2 was 83.8% (95% CI, 83.8%−84%), showing intersubject differences accounting for the variation, and relative to intersubject variation, intrasubjects readings are consistent. Intrasubjects

  17. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping) improves systemic and cerebral oxygenation in preterm lambs.

    Science.gov (United States)

    Polglase, Graeme R; Dawson, Jennifer A; Kluckow, Martin; Gill, Andrew W; Davis, Peter G; Te Pas, Arjan B; Crossley, Kelly J; McDougall, Annie; Wallace, Euan M; Hooper, Stuart B

    2015-01-01

    As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  18. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

    Directory of Open Access Journals (Sweden)

    Graeme R Polglase

    Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  19. Changes in cerebral blood oxygenation induced by active standing test in children with POTS and NMS.

    Science.gov (United States)

    Endo, Ayumi; Fujita, Yukihiko; Fuchigami, Tatsuo; Takahashi, Shori; Mugishima, Hideo; Skatani, Kaoru

    2014-01-01

    Orthostatic dysregulation (OD) has been classified into subtypes by heart rate and blood pressure; however, the hemodynamics of brains have not yet been revealed. Therefore, we investigated changes in cerebral blood flow and oxygenation during an active standing test to clarify the pathophysiology of two subtypes: postural tachycardia syndrome (POTS) and neurally mediated syncope (NMS). We studied 31 children (15 boys, 16 girls; mean age, 14.0 ± 1.7 years) who presented with OD at the Department of Pediatrics and Child Health, Nihon University School of Medicine between 2009 and 2011. OD was diagnosed using the Japanese clinical guidelines for juvenile orthostatic dysregulation. After a 10-min resting period in the supine position, patients were asked to quickly stand up and keep upright for 10 min. Cerebral blood flow and cerebral oxygenation were measured using transcranial Doppler sonography and near-infrared spectroscopy. POTS showed a significant decrease of oxy-Hb and resistance index (RI), suggesting transient ischemia with maintainable cerebral autoregulation. NMS showed a decrease of oxy-Hb and an increase of RI, suggesting ischemia and impairment of autoregulation.

  20. Effects of autoregulation and CO2 reactivity on cerebral oxygen transport.

    Science.gov (United States)

    Payne, S J; Selb, J; Boas, D A

    2009-11-01

    Both autoregulation and CO(2) reactivity are known to have significant effects on cerebral blood flow and thus on the transport of oxygen through the vasculature. In this paper, a previous model of the autoregulation of blood flow in the cerebral vasculature is expanded to include the dynamic behavior of oxygen transport through binding with hemoglobin. The model is used to predict the transfer functions for both oxyhemoglobin and deoxyhemoglobin in response to fluctuations in arterial blood pressure and arterial CO(2) concentration. It is shown that only six additional nondimensional groups are required in addition to the five that were previously found to characterize the cerebral blood flow response. A resonant frequency in the pressure-oxyhemoglobin transfer function is found to occur in the region of 0.1 Hz, which is a frequency of considerable physiological interest. The model predictions are compared with results from the published literature of phase angle at this frequency, showing that the effects of changes in breathing rate can significantly alter the inferred phase dynamics between blood pressure and hemoglobin. The question of whether dynamic cerebral autoregulation is affected under conditions of stenosis or stroke is then examined.

  1. Closed versus open endotracheal suctioning in preterm infants: effects on cerebral oxygenation and blood volume.

    Science.gov (United States)

    Mosca, F A; Colnaghi, M; Lattanzio, M; Bray, M; Pugliese, S; Fumagalli, M

    1997-01-01

    The aim of our study was to compare, using near-infrared spectroscopy (NIRS), the effects on cerebral intracellular oxygenation and cerebral blood volume (CBV) of closed endotracheal suctioning (CS), which permits continuous ventilation of the patient, with open endotracheal suctioning (OS), which requires disconnection from the ventilator. Eleven preterm infants were studied. Each patient underwent one CS, followed, after 60 min, by one OS, or vice versa, three times during the same day. Modifications in CBV and oxidized cytochrome oxidase (CytO2) were continuously detected by NIRS; arterial oxygen saturation (SaO2) heart rate (HR), transcutaneous carbon dioxide tension and mean arterial blood pressure were simultaneously recorded. Significant reductions in HR and SaO2 were observed following OS; the magnitude and duration of these negative effects of suctioning were significantly reduced with CS. In addition, the decrease in CBV was more pronounced than following CS. No changes in CytO2 concentration were seen.

  2. Transient hyperoxia does not affect regional cerebral tissue oxygen saturation in moderately preterm or term newborns

    DEFF Research Database (Denmark)

    Thing, Mira; Sørensen, Line Carøe; Pryds, Ole

    2015-01-01

    oxygen saturation (rStO2 ) and to evaluate whether any observed prolonged cerebral vasoconstriction was related to maturity. METHODS: The study included 30 infants with a postmenstrual age of more than 32 weeks, who were treated with nasal continuous positive airway pressure and a fraction of inspired......, with a mean difference of 1.37% (95% CI 0.15, 2.6). After the second oxygen exposure, rStO2 remained unchanged with a mean difference of -0.4% (95% CI -1.6, 0.78). Differences in rStO2 were not related to gestational age in either of the two hyperoxic episodes. CONCLUSION: We found no evidence to support...... the theory that transient hyperoxia induces prolonged cerebral vasoconstriction in infants with a postmenstrual age above 32 weeks....

  3. Maternal antihypertensive drugs may influence cerebral oxygen extraction in preterm infants during the first days after birth

    NARCIS (Netherlands)

    Verhagen, Elise A.; Kooi, Elisabeth M. W.; van den Berg, Paul P.; Bos, Arend F.

    2013-01-01

    Objective: To determine whether maternal antihypertensive drugs influenced cerebral oxygenation in preterm infants during the first days after birth. Methods: We included 49 preterm infants (median gestational age 30.3 weeks, (range 26.0-31.9), birth weight 1250 g (560-2250)). Regional cerebral oxyg

  4. Cerebral regional oxygen fluctuations and decline during clinically silent focal electroencephalographic seizures in a neonate.

    Science.gov (United States)

    Shuhaiber, Hans; Bolton, Scott; Alfonso, Israel; Dunoyer, Catalina; Yaylali, Ilker

    2004-07-01

    We describe a neonate with tuberous sclerosis complex and right frontal cortical dysplasia who underwent simultaneous near-infrared spectroscopy and electroencephalography (EEG) during repetitive clinically silent right frontal EEG seizures. The seizures produced a progressive decline in regional oxygen saturation index and wider regional oxygen saturation index fluctuations in the right hemisphere than in the left hemisphere. We conclude that recurrent clinically silent focal EEG seizures in this neonate were associated with lateralizing near-infrared spectroscopy changes suggestive of relative cerebral hypoxia.

  5. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward

    2016-01-01

    -remifentanil anaesthesia, and addition of a single remifentanil bolus did not affect regional cerebral oxygen saturation (rSO2). Even though the pool of evidence suggests that propofol and remifentanil alone or in combination have limited effects on CPO in healthy pigs, confirmative evidence is lacking....... and oxygenation (CPO). The evidence evaluated in this systematic review is limited, not focused on propofol and remifentanil and possibly influenced by factors of potential importance for CPO assessment. In one study of healthy pigs, CPO measures were within normal ranges following propofol...

  6. Lung vital capacity and oxygen saturation in adults with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Lampe R

    2014-12-01

    Full Text Available Renée Lampe,1,2 Tobias Blumenstein,2 Varvara Turova,2 Ana Alves-Pinto2 1Markus Würth Stiftungsprofessur, Technical University of Munich, Munich, Germany; 2Research Unit for Cerebral Palsy and Children Neuroorthopaedics of the Buhl-Strohmaier Foundation, Orthopedic Department of the Clinic “rechts der Isar” of the Technical University of Munich, Munich, Germany Background: Individuals with infantile cerebral palsy have multiple disabilities. The most conspicuous syndrome being investigated from many aspects is motor movement disorder with a spastic gait pattern. The lung function of adults with spasticity attracts less attention in the literature. This is surprising because decreased thoracic mobility and longstanding scoliosis should have an impact on lung function. With increasing age and the level of disability, individuals become susceptible to lung infections and reflux illness, and these are accompanied by increased aspiration risk. This study examined, with different methods, to what extent adults with congenital cerebral palsy and acquired spastic paresis – following traumatic brain injury – showed restriction of lung function. It also assessed the contribution of disability level on this restriction.Methods: The oxygen saturation of 46 adults with a diagnosis of cerebral palsy was measured with an oximeter. Lung vital capacity was measured with a mobile spirometer and excursion of the thorax was clinically registered. The gross motor function levels and the presence or absence of scoliosis were determined.Results: A significantly positive correlation between lung vital capacity and chest expansion was established. Both the lung vital capacity and the thorax excursion decreased with increases in gross motor function level. Oxygen saturation remained within the normal range in all persons, in spite of reduced values of the measured lung parameters. No statistically significant dependency between lung vital capacity and oxygen

  7. Cerebral oxygenation during postasphyxial seizures in near-term fetal sheep.

    Science.gov (United States)

    Gonzalez, Hernan; Hunter, Christian J; Bennet, Laura; Power, Gordon G; Gunn, Alistair J

    2005-07-01

    After exposure to asphyxia, infants may develop both prolonged, clinically evident seizures and shorter, clinically silent seizures; however, their effect on cerebral tissue oxygenation is unclear. We therefore examined the hypothesis that the increase in oxygen delivery during postasphyxial seizures might be insufficient to meet the needs of increased metabolism, thus causing a fall in tissue oxygenation, in unanesthetized near-term fetal sheep in utero (gestational age 125+/-1 days). Fetuses were administered an infusion of the specific adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine, followed by 10 mins of asphyxia induced by complete umbilical cord occlusion. The fetuses then recovered for 3 days. Sixty-one episodes of electrophysiologically defined seizures were identified in five fetuses. Tissue PO(2) (tPO(2)) did not change significantly during short seizures (seizures lasting more than 3.5 mins (Pseizures, cortical blood flow did not begin to increase until tPO(2) had begun to fall, and then rose more slowly than the increase in metabolism, with a widening of the brain to blood temperature gradient. In conclusion, in the immature brain, during prolonged, but not short seizures, there is a transient mismatch between cerebral blood flow and metabolism leading to significant cerebral deoxygenation.

  8. Hyperbaric oxygen combined with drug therapy in the treatment of acute cerebral infarction clinical analysis

    Institute of Scientific and Technical Information of China (English)

    Wen-Cui Lin; Kang Lin; Jing Wang; Shuai Li

    2015-01-01

    Objective:To explore the effects of hyperbaric oxygen combined with edaravone, salviae miltiorrhizae and ligustrazine and sodium ozagrel in the treatment of acute cerebral infarction clinical analysis.Methods: A total of 200 cases of acute cerebral infraction patients were randomly divided into observation group and control group. The control group was treated with edaravone, salvia miltiorrhizae and ligustrazine and sodium ozagrel; on the basis of treatment in control group, the observation group was combined with hyperbaric oxygen therapy. The neurological deficit scores were observed before and after treatment in patients of two groups, meanwhile the activities of daily living (ADL) and clinical effects were compared.Results: The total effective rate in observation group (92%) was significantly higher than control group (79%), the differences were statistically significant; the score of ADL in observation group after treatment was obviously higher than control group [(79.91±5.16)vs (61.62±5.60)], and the differences were statistically significant. The neurological deficit scores after treatment were obviously lower than the control group [(9.55±4.13)vs (15.46±4.92)], the differences were statistically significant.Conclusion: Hyperbaric oxygen combined with edaravone, salvia miltiorrhizae and ligustrazine and sodium ozagrel in the treatment of acute cerebral infarction can improve the symptoms of microcirculation and neurologic impairment, and improve the patient s quality of life.

  9. Cerebral arterial gas embolism following diagnostic bronchoscopy: delayed treatment with hyperbaric oxygen.

    Science.gov (United States)

    Wherrett, Chris G; Mehran, Reza J; Beaulieu, Marc-Andre

    2002-01-01

    To describe a clinical scenario consistent with the diagnosis of cerebral arterial gas embolism (CAGE) acquired during an outpatient bronchoscopy. Our discussion explores the mechanisms and diagnosis of CAGE and the role of hyperbaric oxygen therapy. A diagnostic bronchoscopy was performed on a 70-yr-old man who had had a lobectomy for bronchogenic carcinoma three months earlier. During the direct insufflation of oxygen into the right middle lobe bronchus, the patient became unresponsive and developed subcutaneous emphysema. Immediately, an endotracheal tube and bilateral chest tubes were placed with resultant improvement in his oxygen saturation. However, he remained unresponsive with extensor and flexor responses to pain. Later, in the intensive care unit, he exhibited seizure activity requiring anticonvulsant therapy. Sedation was utilized only briefly to facilitate controlled ventilation. Investigations revealed a negative computerized tomography (CT) scan of the head, a normal cerebral spinal fluid examination, a CT chest that showed evidence of barotrauma, and an abnormal electroencephalogram. Fifty-two hours after the event, he was treated for presumed CAGE with hyperbaric oxygen using a modified United States Navy Table 6. Twelve hours later he had regained consciousness and was extubated. He underwent two more hyperbaric treatments and was discharged from hospital one week after the event, fully recovered. A patient with presumed CAGE made a complete recovery following treatment with hyperbaric oxygen therapy even though it was initiated after a significant time delay.

  10. Positron emission tomography in cerebrovascular disease: The relationship between regional cerebral blood flow, blood volume and oxygen metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Herold, S.

    1985-03-01

    Positron emission tomography in cerebrovascular disease has demonstrated the importance of the relationship between regional cerebral blood flow and the cerebral metabolic activity. In acute stroke it has been found that within the first hours after the onset of symptoms cerebral blood flow in the affected area is more depressed than cerebral oxygen utilisation. This relative preservation of oxygen utilisation results from an increase in the oxygen extraction ratio far above its normal value. However, the oxygen extraction fraction subsequently falls in the following days indicating the transition from a situation of possibly reversible ischaemia to irreversible infarction. In patients with carotid occlusive disease an increase in the oxygen extraction ratio has been observed only in very few cases. It has been shown, however, that at an earlier stage the relationship between CBF and CBV (as CBF/CBV-ratio) provides a sensitive measure of diminished perfusion pressure which could be helpful for the selection of patients for EC-IC bypass surgery. In patients with sickle cell anaemia it has been found that oxygen delivery to the brain is maintained by an increase in cerebral blood flow, whereas the oxygen extraction ratio is not increased despite the presence of a low oxygen affinity haemoglobin. Preliminary observations in classical migraine suggest an ischaemic situation during the attack.

  11. Cerebral Oxygenation and Oxygen Extraction in the Preterm Infant during Desaturation : Effects of Increasing FiO(2) to Assist Recovery

    NARCIS (Netherlands)

    Baerts, Willem; Lemmers, Petra M. A.; van Bel, Frank

    2011-01-01

    Background: In the clinical setting, episodes of desaturation in newborn infants are often treated by increasing the fraction of inspired oxygen (FiO(2)). Objectives: To study the effect of an increase in FiO(2) on cerebral oxygenation during recovery from desaturation, as measured by near-infrared

  12. Simulation of Temperature, Nutrients, Biochemical Oxygen Demand, and Dissolved Oxygen in the Catawba River, South Carolina, 1996-97

    Science.gov (United States)

    Feaster, Toby D.; Conrads, Paul A.; Guimaraes, Wladmir B.; Sanders, Curtis L.; Bales, Jerad D.

    2003-01-01

    Time-series plots of dissolved-oxygen concentrations were determined for various simulated hydrologic and point-source loading conditions along a free-flowing section of the Catawba River from Lake Wylie Dam to the headwaters of Fishing Creek Reservoir in South Carolina. The U.S. Geological Survey one-dimensional dynamic-flow model, BRANCH, was used to simulate hydrodynamic data for the Branched Lagrangian Transport Model. Waterquality data were used to calibrate the Branched Lagrangian Transport Model and included concentrations of nutrients, chlorophyll a, and biochemical oxygen demand in water samples collected during two synoptic sampling surveys at 10 sites along the main stem of the Catawba River and at 3 tributaries; and continuous water temperature and dissolved-oxygen concentrations measured at 5 locations along the main stem of the Catawba River. A sensitivity analysis of the simulated dissolved-oxygen concentrations to model coefficients and data inputs indicated that the simulated dissolved-oxygen concentrations were most sensitive to watertemperature boundary data due to the effect of temperature on reaction kinetics and the solubility of dissolved oxygen. Of the model coefficients, the simulated dissolved-oxygen concentration was most sensitive to the biological oxidation rate of nitrite to nitrate. To demonstrate the utility of the Branched Lagrangian Transport Model for the Catawba River, the model was used to simulate several water-quality scenarios to evaluate the effect on the 24-hour mean dissolved-oxygen concentrations at selected sites for August 24, 1996, as simulated during the model calibration period of August 23 27, 1996. The first scenario included three loading conditions of the major effluent discharges along the main stem of the Catawba River (1) current load (as sampled in August 1996); (2) no load (all point-source loads were removed from the main stem of the Catawba River; loads from the main tributaries were not removed); and (3

  13. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

    Directory of Open Access Journals (Sweden)

    Aminath eAzhan

    2012-12-01

    Full Text Available Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenalin, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their -adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF. Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in

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

    Institute of Scientific and Technical Information of China (English)

    Bao-chun Zhou; Li-jun Liu; Bing Liu

    2016-01-01

    Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO2) and oxygen partial pressure (PaO2). To test this idea, we compared two groups:a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO2 were measured. The controls were also examined for rSO2 and PaO2, but received no treatment. rSO2 levels in the patients did not differ signiifcantly after treatment, but levels before and after treatment were signiifcantly lower than those in the control group. PaO2 levels were signiifcantly decreased after the 30-minute HBO treatment. Our ifndings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

  15. Non-steady response of BOD biosensor for the determination of biochemical oxygen demand in wastewater.

    Science.gov (United States)

    Velling, Siiri; Mashirin, Alexey; Hellat, Karin; Tenno, Toomas

    2011-01-01

    A biochemical oxygen demand (BOD) biosensor for effective and expeditious BOD(7) estimations was constructed and the non-steady phase of the output signal was extensively studied. The modelling approach introduced allows response curve reconstruction and a curve fitting procedure of good quality, resulting in parameters indicating the relationship between response and organic substrate concentration and stability properties of the BOD biosensor. Also, the immobilization matrixes of different thicknesses were characterized to determine their suitability for bio-sensing measurements in non-stationary conditions, as well as for the determination of the mechanical durability of the BOD biosensor in time. The non-steady response of the experimental output of the BOD biosensor was fitted according to the developed model that enables to determine the stability of the biosensor output and dependency on biodegradable organic substrate concentration. The calibration range of the studied BOD biosensor in OECD synthetic wastewater was 15-110 mg O(2) L(-1). Repeatability tests showed relative standard deviation (RSD) values of 2.8% and 5.8% for the parameter τ(d), characterizing the transient output of the amperometric oxygen sensor in time, and τ(s), describing the dependency of the transient response of the BOD biosensor on organic substrate concentration, respectively. BOD biosensor experiments for the evaluation of the biochemical oxygen demand of easily degradable and refractory municipal wastewater showed good concurrence with traditional BOD(7) analysis.

  16. Monitorization of the effects of spinal anaesthesia on cerebral oxygen saturation in elder patients using near-infrared spectroscopy.

    Science.gov (United States)

    Kusku, Aysegul; Demir, Guray; Cukurova, Zafer; Eren, Gulay; Hergunsel, Oya

    2014-01-01

    Central blockage provided by spinal anaesthesia enables realization of many surgical procedures, whereas hemodynamic and respiratory changes influence systemic oxygen delivery leading to the potential development of series of problems such as cerebral ischemia, myocardial infarction and acute renal failure. This study was intended to detect potentially adverse effects of hemodynamic and respiratory changes on systemic oxygen delivery using cerebral oxymetric methods in patients who underwent spinal anaesthesia. Twenty-five ASA I-II Group patients aged 65-80 years scheduled for unilateral inguinal hernia repair under spinal anaesthesia were included in the study. Following standard monitorization baseline cerebral oxygen levels were measured using cerebral oximetric methods. Standardized Mini Mental Test (SMMT) was applied before and after the operation so as to determine the level of cognitive functioning of the cases. Using a standard technique and equal amounts of a local anaesthetic drug (15mg bupivacaine 5%) intratechal blockade was performed. Mean blood pressure (MBP), maximum heart rate (MHR), peripheral oxygen saturation (SpO2) and cerebral oxygen levels (rSO2) were preoperatively monitored for 60min. Pre- and postoperative haemoglobin levels were measured. The variations in data obtained and their correlations with the cerebral oxygen levels were investigated. Significant changes in pre- and postoperative measurements of haemoglobin levels and SMMT scores and intraoperative SpO2 levels were not observed. However, significant variations were observed in intraoperative MBP, MHR and rSO2 levels. Besides, a correlation between variations in rSO2, MBP and MHR was determined. Evaluation of the data obtained in the study demonstrated that post-spinal decline in blood pressure and also heart rate decreases systemic oxygen delivery and adversely effects cerebral oxygen levels. However, this downward change did not result in deterioration of cognitive functioning

  17. [Monitorization of the effects of spinal anaesthesia on cerebral oxygen saturation in elder patients using near-infrared spectroscopy].

    Science.gov (United States)

    Kusku, Aysegul; Demir, Guray; Cukurova, Zafer; Eren, Gulay; Hergunsel, Oya

    2014-01-01

    Central blockage provided by spinal anaesthesia enables realization of many surgical procedures, whereas hemodynamic and respiratory changes influence systemic oxygen delivery leading to the potential development of series of problems such as cerebral ischemia, myocardial infarction and acute renal failure. This study was intended to detect potentially adverse effects of hemodynamic and respiratory changes on systemic oxygen delivery using cerebral oxymetric methods in patients who underwent spinal anaesthesia. Twenty-five ASA I-II Group patients aged 65-80 years scheduled for unilateral inguinal hernia repair under spinal anaesthesia were included in the study. Following standard monitorization baseline cerebral oxygen levels were measured using cerebral oximetric methods. Standardized Mini Mental Test (SMMT) was applied before and after the operation so as to determine the level of cognitive functioning of the cases. Using a standard technique and equal amounts of a local anaesthetic drug (15mg bupivacaine 5%) intratechal blockade was performed. Mean blood pressure (MBP), maximum heart rate (MHR), peripheral oxygen saturation (SpO2) and cerebral oxygen levels (rSO2) were preoperatively monitored for 60min. Pre- and postoperative haemoglobin levels were measured. The variations in data obtained and their correlations with the cerebral oxygen levels were investigated. Significant changes in pre- and postoperative measurements of haemoglobin levels and SMMT scores and intraoperative SpO2 levels were not observed. However, significant variations were observed in intraoperative MBP, MHR and rSO2 levels. Besides, a correlation between variations in rSO2, MBP and MHR was determined. Evaluation of the data obtained in the study demonstrated that post-spinal decline in blood pressure and also heart rate decreases systemic oxygen delivery and adversely effects cerebral oxygen levels. However, this downward change did not result in deterioration of cognitive functioning

  18. Monitorization of the effects of spinal anaesthesia on cerebral oxygen saturation in elder patients using near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Aysegul Kusku

    2014-07-01

    Full Text Available OBJECTIVE: Central blockage provided by spinal anaesthesia enables realization of many surgical procedures, whereas hemodynamic and respiratory changes influence systemic oxygen delivery leading to the potential development of series of problems such as cerebral ischemia, myocardial infarction and acute renal failure. This study was intended to detect potentially adverse effects of hemodynamic and respiratory changes on systemic oxygen delivery using cerebral oxymetric methods in patients who underwent spinal anaesthesia. METHODS: Twenty-five ASA I-II Group patients aged 65-80 years scheduled for unilateral inguinal hernia repair under spinal anaesthesia were included in the study. Following standard monitorization baseline cerebral oxygen levels were measured using cerebral oximetric methods. Standardized Mini Mental Test (SMMT was applied before and after the operation so as to determine the level of cognitive functioning of the cases. Using a standard technique and equal amounts of a local anaesthetic drug (15 mg bupivacaine 5% intratechal blockade was performed. Mean blood pressure (MBP, maximum heart rate (MHR, peripheral oxygen saturation (SpO2 and cerebral oxygen levels (rSO2 were preoperatively monitored for 60 min. Pre- and postoperative haemoglobin levels were measured. The variations in data obtained and their correlations with the cerebral oxygen levels were investigated. RESULTS: Significant changes in pre- and postoperative measurements of haemoglobin levels and SMMT scores and intraoperative SpO2 levels were not observed. However, significant variations were observed in intraoperative MBP, MHR and rSO2 levels. Besides, a correlation between variations in rSO2, MBP and MHR was determined. CONCLUSION: Evaluation of the data obtained in the study demonstrated that post-spinal decline in blood pressure and also heart rate decreases systemic oxygen delivery and adversely effects cerebral oxygen levels. However, this downward change did

  19. Monitoring cerebral tissue oxygen saturation at frontal and parietal regions during carotid artery stenting.

    Science.gov (United States)

    Meng, Lingzhong; Hall, Melanie; Settecase, Fabio; Higashida, Randall T; Gelb, Adrian W

    2016-04-01

    Cerebral oximetry is normally placed on the upper forehead to monitor the frontal lobe cerebral tissue oxygen saturation (SctO2). We present a case in which the SctO2 was simultaneously monitored at both frontal and parietal regions during internal carotid artery (ICA) stenting. Our case involves a 79-year-old man who presented after a sudden fall and was later diagnosed with a watershed ischemic stroke in the distal fields perfused by the left middle cerebral artery. He had diffuse atherosclerotic occlusive lesions in the carotid and cerebral arterial systems including an 85 % stenotic lesion in the left distal cervical ICA. The brain territory perfused by the left ICA was devoid of collateral flow from anterior and posterior communicating arteries due to an abnormal circle of Willis. During stenting, the SctO2 monitored at both frontal and parietal regions tracked the procedure-induced acute flow change. However, the baseline SctO2 values of frontal and parietal regions differed. The SctO2-MAP correlation was more consistent on the stroked hemisphere than the non-stroked hemisphere. This case showed that SctO2 can be reliably monitored at the parietal region, which is primarily perfused by the ICA. SctO2 of the stroked brain is more pressure dependent than the non-stroked brain.

  20. Explorations on Temperature, Oxygen, Nutrients and Habitat Demands of Fish Species Found in River Coruh

    Directory of Open Access Journals (Sweden)

    Bilal Akbulut

    2009-04-01

    Full Text Available For the protection of our natural resources, fish species being economic and ecological richness of the natural in the basin of the Çoruh to know their request is extremely a vital important issue. In this study, temperature and oxygen demand, food and habitat of 18 fish species in six families found in river Çoruh assessed and discussed with the literature and database. Limiting the impact of water temperature on the reproductive, growth and nutrition emphasized. The fish species in the basin spawn at temperatures between 14-30°C according to database. Three species belonging to a family feed with animal food floating in the water. The species belonging to the other families more feed mixed with plant and animal foods diet in the floor or near the ground. Importance of their environmental demands has clarified for conservation and sustainable use of these fish species inhabiting in Çoruh River.

  1. A MEMS approach to determine the biochemical oxygen demand (BOD) of wastewaters

    Science.gov (United States)

    Recoules, L.; Migaou, A.; Dollat, X.; Thouand, G.; Gue, A. M.; Boukabache, A.

    2017-07-01

    A MEMS approach to obtain an efficient tool for the evaluation of the biochemical oxygen demand (BOD) of wastewaters is introduced. Its operating principle is based on the measurement of oxygen concentration in water samples containing organic pollutants and specific bacteria. The microsystem has been designed to perform multiple and parallel measurements in a poly-wells microfluidic device. The monitoring of the bacterial activity is ensured by optical sensors incorporated in each well of the fluidic network. By using an optode sensor, it is hereby demonstrated that this approach is efficient to measure organic pollutants by testing different Luria Bertani buffer dilutions. These results also show that it is possible to reduce the duration of measurements from 5 d (BOD5) of the standard approach to few hours, typically 3 h-5 h.

  2. Sediment Oxygen Demand in Cochin backwaters, a tropical estuarine system in the south-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Abhilash, K.R.; Raveendran, T.V.; LimnaMol, V.P.; Deepak, M.P.

    Eutrophication has often been one of the major problems encountered in estuaries and coastal waters. The oxic/anoxic status of an estuary can be effectively determined by measurement of the Sediment Oxygen Demand (SOD). An attempt is made...

  3. Water oxygen demand no. 2, study number 21: report of a study conducted by the Analytical Reference Service Training Program

    National Research Council Canada - National Science Library

    1968-01-01

    This study consisted of four samples which 74 participating laboratories were instructed to dilute to a specified volume and analyze by both the Standard Method for Chemical Oxygen Demand and by the...

  4. Reduced cerebral oxygen-carbohydrate index during endotracheal intubation in vascular surgical patients.

    Science.gov (United States)

    Fabricius-Bjerre, Andreas; Overgaard, Anders; Winther-Olesen, Marie; Lönn, Lars; Secher, Niels H; Nielsen, Henning B

    2015-09-01

    Brain activation reduces balance between cerebral consumption of oxygen versus carbohydrate as expressed by the so-called cerebral oxygen-carbohydrate-index (OCI). We evaluated whether preparation for surgery, anaesthesia including tracheal intubation and surgery affect OCI. In patients undergoing aortic surgery, arterial to internal jugular venous (a-v) concentration differences for oxygen versus lactate and glucose were determined from before anaesthesia to when the patient left the recovery room. Intravenous anaesthesia was supplemented with thoracic epidural anaesthesia for open aortic surgery (n = 5) and infiltration with bupivacaine for endovascular procedures (n = 14). The a-v difference for O2 decreased throughout anaesthesia and in the recovery room (1.6 ± 1.9 versus 3.2 ± 0.8 mmol l(-1), mean ± SD), and while a-v glucose decreased during surgery and into the recovery (0.4 ± 0.2 versus 0.7 ± 0.2 mmol l(-1) , Pintubation (Pintubation decrease OCI that recovers during surgery under the influence of sensory blockade. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  5. Cerebral blood flow and oxygen metabolism in dementia with Lewy bodies

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yoshitomo; Takahashi, Satoshi; Yonezawa, Hisashi [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2000-06-01

    Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO{sub 2}) and the oxygen extraction fraction (rOEF) were measured using the steady-state {sup 15}O technique and positron emission tomography (PET) in six patients with dementia with Lewy bodies (DLB), and compared with ten patients with Alzheimer disease (AD) and six normal controls. In the AD patients, rCBF and rCMRO{sub 2} were significantly decreased in the frontal, parietal, and temporal cortices compared with controls. In DLB patients, rCBF and rCMRO{sub 2} were decreased in the frontal, parietal, temporal, and occipital cortices compared with controls, and were decreased more diffusely than in AD patients. rCBF and rCMRO{sub 2} were significantly decreased in occipital cortex compared with AD patients. rOEF was significantly increased in the parieto-temporal cortex in AD patients compared with controls. In DLB patients, rOEF was significantly increased not only in the parieto-temporal cortex but also in the occipital and frontal cortices compared with controls, and was significantly increased in the occipital cortex compared with AD patients. The diffuse reduction of cerebral blood flow and oxygen metabolism including the occipital cortex may be related to visual hallucination and other visuospatial deficits frequently seen in DLB patients. The increase in rOEF may be mainly due to the reduction in the vascular bed associated with decreased activity in the vasodilatory cholinergic system. (author)

  6. Low Cerebral Oxygen Consumption and Blood Flow in Patients With Cirrhosis and an Acute Episode of Hepatic Encephalopathy

    DEFF Research Database (Denmark)

    Iversen, Peter; Bak, Lasse Kristoffer; Waagepetersen, Helle Sønderby

    2009-01-01

    BACKGROUND & AIMS: It is unclear whether patients with hepatic encephalopathy (HE) have disturbed brain oxygen metabolism and blood flow. METHODS: We measured cerebral oxygen metabolism rate (CMRO(2)) by using (15)O-oxygen positron emission tomography (PET), and cerebral blood flow (CBF) by using....../min in patients with HE, 0.47 +/- 0.02 in patients without HE, and 0.49 +/- 0.03 in healthy subjects. CMRO(2) and CBF were correlated, and both variables correlated negatively with arterial ammonia concentration. Analysis of regional values, using individual magnetic resonance co-registrations, showed...... that the reductions in CMRO(2) and CBF in patients with HE were essentially generalized throughout the brain. CONCLUSIONS: The observations imply that reduced cerebral oxygen consumption and blood flow in cirrhotic patients with an acute episode of overt HE are associated with HE and not cirrhosis as such...

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

    Science.gov (United States)

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

    2015-08-01

    Plateau waves in intracranial pressure (ICP) are frequently recorded in neuro intensive care and are not yet fully understood. To further investigate this phenomenon, we analyzed partial pressure of cerebral oxygen (pbtO2) and a moving correlation coefficient between ICP and mean arterial blood pressure (ABP), called PRx, along with the cerebral oxygen reactivity index (ORx), which is a moving correlation coefficient between cerebral perfusion pressure (CPP) and pbtO2 in an observational study. We analyzed 55 plateau waves in 20 patients after severe traumatic brain injury. We calculated ABP, ABP pulse amplitude (ampABP), ICP, CPP, pbtO2, heart rate (HR), ICP pulse amplitude (ampICP), PRx, and ORx, before, during, and after each plateau wave. The analysis of variance with Bonferroni post hoc test was used to compare the differences in the variables before, during, and after the plateau wave. We considered all plateau waves, even in the same patient, independent because they are separated by long intervals. We found increases for ICP and ampICP according to our operational definitions for plateau waves. PRx increased significantly (p = 0.00026), CPP (p waves. ABP, ampABP, and HR remained unchanged. PRx during the plateau was higher than before the onset of wave in 40 cases (73 %) with no differences in baseline parameters for those with negative and positive ΔPRx (difference during and after). ORx showed an increase during and a decrease after the plateau waves, however, not statistically significant. PbtO2 overshoot after the wave occurred in 35 times (64 %), the mean difference was 4.9 ± 4.6 Hg (mean ± SD), and we found no difference in baseline parameters between those who overshoot and those who did not overshoot. Arterial blood pressure remains stable in ICP plateau waves, while cerebral autoregulatory indices show distinct changes, which indicate cerebrovascular reactivity impairment at the top of the wave. PbtO2 decreases during the waves and may

  8. Influence of moderate hypothermia on cerebral oxygenation in pigs with intracranial hypertension

    Institute of Scientific and Technical Information of China (English)

    Yinghui Bao; Yumin Liang; Jiyao Jiang; Qizhong Luo; Yicheng Lu

    2007-01-01

    BACKGROUND: Moderate hypothermia is one of the effective therapeutic methods for head injury in recent years, there are many mechanisms of moderate hypothermia for brain protection, and its influence on cerebral oxygenation is also one of them.OBJECTIVE: To observe the influence of moderate hypothermia on cerebral oxygenation of animals with acute intracranial hypertension, and further investigate the protective mechanism of moderate hypothermia. DESIGN: A randomized controlled trial.SETTING: Department of Neurosurgery, Renji Hospital affiliated to the Medical College of Shanghai Jiao Tong University.MATERIALS: Twenty healthy little pigs, either male or female, weighing 4.5 - 5.5 kg, were used. Neurotrend-typed multiparameter monitoring system (Diametrics Company, British); CMA/100micro-injection pump (Carnegie Company, Sweden).METHODS: The experiment was conducted in the Changzheng Hospital affiliated to the Second Military Medical University of Chinese PLA in November, 2001. The pigs were randomized into two groups: the normothermia group (control group, n =10) and moderate hypothermia group (n =10). ①Bilateral femoral arteries were separated, one was connected to pressometer for monitoring mean arterial pressure (MEP), and the other for analysis of blood gases [including peripheral blood Ph value, arterial partial pressure of carbon dioxide (PaCCh), arterial partial pressure of carbon dioxide (PaCO2), HCO3-].②Rectal temperature was monitored with mercurial thermometer.③Intracranial pressure was monitored using Camino optic ICP probe placed in the subdural space. ④Neurotrend multiparameter monitoring sensor was inserted into the white matter for about 4 cm to determine cerebral perfusion pressure (CPP, CPP=MAP(ICP), brain tissue partial oxygen pressure (PO2), partial pressure of carbon dioxide (PCCh), HCO3- and brain temperature. The rectal temperature of animals in the moderate hypothermia group was lowered to 34℃ using ice bags, and the body

  9. Performance of an electrochemical COD (chemical oxygen demand) sensor with an electrode-surface grinding unit.

    Science.gov (United States)

    Geun Jeong, Bong; Min Yoon, Seok; Ho Choi, Chang; Koang Kwon, Kil; Sik Hyun, Moon; Heui Yi, Dong; Soo Park, Hyung; Kim, Mia; Joo Kim, Hyung

    2007-12-01

    An electrochemical COD (chemical oxygen demand) sensor using an electrode-surface grinding unit was investigated. The electrolyzing (oxidizing) action of copper on an organic species was used as the basis of the COD measuring sensor. Using a simple three-electrode cell and a surface grinding unit, the organic species is activated by the catalytic action of copper and oxidized at a working electrode, poised at a positive potential. When synthetic wastewater was fed into the system, the measured Coulombic yields were found to be dependent on the COD of the synthetic wastewater. A linear correlation between the Coulombic yields and the COD of the synthetic wastewater was established (10-1000 mg L(-1)) when the electrode-surface grinding procedure was activated briefly at 8 h intervals. When various kinds of wastewater samples obtained from various sewage treatment plants were measured, linear correlations (r(2)> or = 0.92) between the measured EOD (electrochemical oxygen demand) value and COD of the samples were observed. At a practical wastewater treatment plant, the measurement system was successfully operated with high accuracy and good stability over 3 months. These experimental results show that the application of the measurement system would be a rapid and practical method for the determination of COD in water industries.

  10. Renal Doppler Resistive Index as a Marker of Oxygen Supply and Demand Mismatch in Postoperative Cardiac Surgery Patients

    National Research Council Canada - National Science Library

    Corradi, Francesco; Brusasco, Claudia; Paparo, Francesco; Manca, Tullio; Santori, Gregorio; Benassi, Filippo; Molardi, Alberto; Gallingani, Alan; Ramelli, Andrea; Gherli, Tiziano; Vezzani, Antonella

    2015-01-01

    ... response to oxygen supply and demand mismatch. In two previous studies, RDRI has been shown to be able to detect tissue hypoperfusion and oxygenation due to occult hemorrhagic shock in hemodynamically stable polytrauma patients [4] and to correlate with levels of arterial standard base excess and expression of tissue hypoxia [5]. Mor...

  11. Ethanol Demand in United States Production of Oxygenate-limited Gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.

    2000-08-16

    Ethanol competes with methyl tertiary butyl ether (MTBE) to satisfy oxygen, octane, and volume requirements of certain gasolines. However, MTBE has water quality problems that may create significant market opportunities for ethanol. Oak Ridge National Laboratory (ORNL) has used its Refinery Yield Model to estimate ethanol demand in gasolines with restricted use of MTBE. Reduction of the use of MTBE would increase the costs of gasoline production and possibly reduce the gasoline output of U.S. refineries. The potential gasoline supply problems of an MTBE ban could be mitigated by allowing a modest 3 vol percent MTBE in all gasoline. In the U.S. East and Gulf Coast gasoline producing regions, the 3 vol percent MTBE option results in costs that are 40 percent less than an MTBE ban. In the U.S. Midwest gasoline producing region, with already high use of ethanol, an MTBE ban has minimal effect on ethanol demand unless gasoline producers in other regions bid away the local supply of ethanol. The ethanol/MTBE issue gained momentum in March 2000 when the Clinton Administration announced that it would ask Congress to amend the Clean Air Act to provide the authority to significantly reduce or eliminate the use of MTBE; to ensure that air quality gains are not diminished as MTBE use is reduced; and to replace the existing oxygenate requirement in the Clean Air Act with a renewable fuel standard for all gasoline. Premises for the ORNL study are consistent with the Administration announcement, and the ethanol demand curve estimates of this study can be used to evaluate the impact of the Administration principles and related policy initiatives.

  12. Monitoring Cerebral and Renal Oxygenation Status during Neonatal Digestive Surgeries Using Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Jonathan Beck

    2017-06-01

    Full Text Available BackgroundDepending on the initial pathology, hypovolemia, intra-abdominal hypertension, and sepsis are often encountered in neonatal digestive surgery. Accurate newborn monitoring during and after surgery is essential to adapt resuscitation protocols. Near infrared spectroscopy (NIRS is non-invasive and can detect hypoperfusion which indicates a low circulatory blood flow, regardless of the cause.ObjectiveEvaluating changes in cerebral and renal regional oxygen saturation during neonatal digestive surgeries, conducted according to normal practices, with commonly used monitoring parameters. Analyzing retrospectively the inter-relationships between NIRS values and mean arterial pressure (MAP values as well as pre-ductal SpO2.MethodsProspective, descriptive, monocentric study. All neonates referred for surgery were included. NIRS allows the measurement of cerebral and renal oxygenation fluctuations, as well as calculating difference in intraoperative and postoperative values.ResultsNineteen patients were included. Cerebral regional oxygen saturation (C rSO2 values were stable while renal regional oxygen saturation (R rSO2 values tended to decrease with time during surgery. Indeed, 72% of rSO2 decline episodes occurred after the first 30 min of surgery, without any significant statistical differences for the next 90 min of surgery. After surgery, the lowest average C and R rSO2 values were evidenced during the first 6 h, with 60% of C rSO2 and R rSO2 anomalies occurring in that time frame. There was no significant statistical difference observed in the following 18 h. There was a significant correlation between R rSO2 and SpO2 values (p < 0.01, but not with C rSO2 values. There was no correlation with the MAP either for the C rSO2 values or R rSO2 ones.ConclusionNIRS is a promising non-invasive bedside tool to monitor cerebral and tissue perfusion, analyzing tissue microcirculation. NIRS has its interest to guide neonatal digestive

  13. Effects of aging on cerebral blood flow, oxygen metabolism, and blood oxygenation level dependent responses to visual stimulation.

    Science.gov (United States)

    Ances, Beau M; Liang, Christine L; Leontiev, Oleg; Perthen, Joanna E; Fleisher, Adam S; Lansing, Amy E; Buxton, Richard B

    2009-04-01

    Calibrated functional magnetic resonance imaging (fMRI) provides a noninvasive technique to assess functional metabolic changes associated with normal aging. We simultaneously measured both the magnitude of the blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) responses in the visual cortex for separate conditions of mild hypercapnia (5% CO(2)) and a simple checkerboard stimulus in healthy younger (n = 10, mean: 28-years-old) and older (n = 10, mean: 53-years-old) adults. From these data we derived baseline CBF, the BOLD scaling parameter M, the fractional change in the cerebral metabolic rate of oxygen consumption (CMRO(2)) with activation, and the coupling ratio n of the fractional changes in CBF and CMRO(2). For the functional activation paradigm, the magnitude of the BOLD response was significantly lower for the older group (0.57 +/- 0.07%) compared to the younger group (0.95 +/- 0.14%), despite the finding that the fractional CBF and CMRO(2) changes were similar for both groups. The weaker BOLD response for the older group was due to a reduction in the parameter M, which was significantly lower for older (4.6 +/- 0.4%) than younger subjects (6.5 +/- 0.8%), most likely reflecting a reduction in baseline CBF for older (41.7 +/- 4.8 mL/100 mL/min) compared to younger (59.6 +/- 9.1 mL/100 mL/min) subjects. In addition to these primary responses, for both groups the BOLD response exhibited a post-stimulus undershoot with no significant difference in this magnitude. However, the post-undershoot period of the CBF response was significantly greater for older compared to younger subjects. We conclude that when comparing two populations, the BOLD response can provide misleading reflections of underlying physiological changes. A calibrated approach provides a more quantitative reflection of underlying metabolic changes than the BOLD response alone.

  14. Effects of incremental exercise on cerebral oxygenation measured by near-infrared spectroscopy: a systematic review.

    Science.gov (United States)

    Rooks, Cherie R; Thom, Nathaniel J; McCully, Kevin K; Dishman, Rod K

    2010-10-01

    We conducted a systematic review and meta-regression analysis to quantify effects of exercise on brain hemodynamics measured by near-infrared spectroscopy (NIRS). The results indicate that acute incremental exercise (categorized relative to aerobic capacity (VO(2)peak) as low - <30% VO(2)peak; moderate - ≥30% VO(2)peak to <60% VO(2)peak; hard - ≥60% VO(2)peak to oxygenated hemoglobin (O(2)Hb) or other measures of oxygen level (O(2)Hbdiff) or saturation (SCO(2)) (0.92±0.67, 1.17), deoxygenated hemoglobin (dHb) (0.87±0.56, 1.19), and blood volume estimated by total hemoglobin (tHb) (1.21±0.84, 1.59). After peaking at hard intensities, cerebral oxygen levels dropped during very hard intensities. People who were aerobically trained attained higher levels of cortical oxygen, dHb, and tHb than untrained people during very hard intensities. Among untrained people, a marked drop in oxygen levels and a small increase in dHb at very hard intensities accompanied declines in tHb, implying reduced blood flow. In 6 studies of 222 patients with heart or lung conditions, oxygenation and dHb were lowered or unchanged during exercise compared to baseline. In conclusion, prefrontal oxygenation measured with NIRS in healthy people showed a quadratic response to incremental exercise, rising between moderate and hard intensities, then falling at very hard intensities. Training status influenced the responses. While methodological improvements in measures of brain oxygen are forthcoming, these results extend the evidence relevant to existing models of central limitations to maximal exercise.

  15. Sedimentary microbial oxygen demand for laminar flow over a sediment bed of finite length.

    Science.gov (United States)

    Higashino, Makoto; Stefan, Heinz G

    2005-09-01

    Dead organic material accumulated on the bed of a lake, reservoir or wetland often provides the substrate for substantial microbial activity as well as chemical processes that withdraw dissolved oxygen (DO) from the water column. A model to estimate the actual DO profile and the "sedimentary oxygen demand (SOD)" must specify the rate of microbial or chemical activity in the sediment as well as the diffusive supply of DO from the water column through the diffusive boundary layer into the sediment. Most previous experimental and field studies have considered this problem with the assumptions that the diffusive boundary layer is (a) turbulent and (b) fully developed. These assumptions require that (a) the flow velocity above the sediment bed is fast enough to produce turbulent mixing in the boundary layer, and (b) the sediment bed is long. In this paper a model for laminar flow and SOD over a sediment bed of finite length is presented and the results are compared with those for turbulent flow. Laminar flow near a sediment bed is encountered in quiescent water bodies such as lakes, reservoirs, river backwaters, wetlands and ponds under calm wind conditions. The diffusive oxygen transfer through the laminar diffusive boundary layer above the sediment surface can restrict the microbial or chemical oxygen uptake inside the sediment significantly. The developing laminar diffusive boundary layer above the sediment/water interface is modeled based on the analogy with heat transfer, and DO uptake inside the sediment is modeled by Michaelis-Menten microbial growth kinetics. The model predicts that the rate of SOD at the beginning of the reactive sediment bed is solely dependent on microbial density in the sediment regardless of flow velocity and type. The rate of SOD, and the DO penetration depth into the sediment decrease in stream-wise direction over the length of the sediment bed, as the diffusive boundary layer above the sediment/water interface thickens. With increasing

  16. Demonstration study of biofilm reactor based rapid biochemical oxygen demand determination of surface water

    Directory of Open Access Journals (Sweden)

    Changyu Liu

    2016-05-01

    Full Text Available Application investigations of rapid biochemical oxygen demand (BOD online analyzer for surface water in Wuxi, China were carried out since 2013. The analyzer adopted a novel working principle, that is, the oxygen concentration of the sample to be tested was regarded as a reference, and the oxygen consumption by the biofilm reactor (BFR was calculated according to the difference between the reference and sample effluent from BFR. The BFR was fabricated via a cultivation process using naturally occurring microbial seeds from in site surface water. This analytical principle was first presented and clearly clarified, and the impact of microbial endogenous respiration to the measured values was also proposed and analyzed. The improved analyzers were equipped in three application sites with significant differences in BOD concentration, for the purpose of evaluating the feasibility and applicability of the proposed method. This study revealed that the online analyzer could continually operate over 30 days without human intervention and additional chemical reagent consumption. The obtained rapid BOD trend line showed that this analyzer could track the fluctuation of the biodegradable organic compound level timely and accurately. The innovative analytical method, as well as the outstanding adaptation and well accuracy rating, provided the highlights for wide applications in the future.

  17. Analysis of nitrogenous and algal oxygen demand in effluent from a system of aerated lagoons followed by polishing pond.

    Science.gov (United States)

    Khorsandi, Hassan; Alizadeh, Rahimeh; Tosinejad, Horiyeh; Porghaffar, Hadi

    2014-01-01

    In this descriptive-analytical study, nitrogenous and algal oxygen demand were assessed for effluent from a system of facultative partially mixed lagoons followed by the polishing pond using 120 grab samples over 1 year. Filtered and non-filtered samples of polishing pond effluent were tested in the presence and absence of a nitrification inhibitor. Effective factors, including 5-day biochemical and chemical oxygen demand (BOD and COD), total suspended solids (TSS), dissolved oxygen, chlorophyll A, and temperature, were measured using standard methods for water and wastewater tests. The results were analyzed using repeated measures analysis of variance with SPSS version 16. Findings show that the annual mean of the total 5-day BOD in the effluent from the polishing pond consisted of 44.92% as the algal carbonaceous biochemical oxygen demand (CBOD), 43.61% as the nitrogenous biochemical oxygen demand (NBOD), and 11.47% as the soluble CBOD. According to this study, the annual mean ratios of algal COD and 5-day algal CBOD to TSS were 0.8 and 0.37, respectively. As the results demonstrate, undertaking quality evaluation of the final effluent from the lagoons without considering nitrogenous and algal oxygen demand would undermine effluent quality assessment and interpretation of the performance of the wastewater treatment plant.

  18. Role of cerebral oxygenation for prediction of hypotension after spinal anesthesia for caesarean section.

    Science.gov (United States)

    Sun, Shen; Liu, Nai-He; Huang, Shao-Qiang

    2016-08-01

    To investigate the role of cerebral oxygen saturation (ScO2) for prediction of hypotension after spinal anesthesia for caesarean section. Forty-five parturients undergoing elective caesarean section under spinal anesthesia were selected. Blood pressure, heart rate and pulse oxygen saturation before and after anesthesia were recorded, and the association between changes in ScO2 before and after anesthesia with hypotension after spinal anesthesia was explored. Hypotension occurred in 32 parturients after spinal anesthesia. The decrease in ScO2 after spinal anesthesia in parturients with hypotension was larger than in parturients without hypotension (P spinal anesthesia is associated with hypotension after spinal anesthesia for cesarean section, and may be a clinically useful predictor.

  19. Effects of diving and oxygen on autonomic nervous system and cerebral blood flow.

    Science.gov (United States)

    Winklewski, Pawel J; Kot, Jacek; Frydrychowski, Andrzej F; Nuckowska, Magdalena K; Tkachenko, Yurii

    2013-09-01

    Recreational scuba diving is a popular leisure activity with the number of divers reaching several millions worldwide. Scuba diving represents a huge challenge for integrative physiology. In mammalian evolution, physiological reflexes developed to deal with lack of oxygen, rather than with an excess, which makes adaptations to scuba diving more difficult to describe and understand than those associated with breath-hold diving. The underwater environment significantly limits the use of equipment to register the organism's functions, so, in most instances, scientific theories are built on experiments that model real diving to some extent, like hyperbaric exposures, dive reflexes or water immersion. The aim of this review is to summarise the current knowledge related to the influence exerted by physiological conditions specific to diving on the autonomic nervous system and cerebral blood flow. The main factors regulating cerebral blood flow during scuba diving are discussed as follows: 1) increased oxygen partial pressure; 2) immersion-related trigemino-cardiac reflexes and 3) exposure to cold, exercise and stress. Also discussed are the potential mechanisms associated with immersion pulmonary oedema.

  20. Cerebral oxygenation monitoring in patients with bilateral carotid stenosis undergoing urgent cardiac surgery: Observational case series

    Directory of Open Access Journals (Sweden)

    Dincer Aktuerk

    2016-01-01

    Full Text Available Background: Patients with significant bilateral carotid artery stenosis requiring urgent cardiac surgery have an increased risk of stroke and death. The optimal management strategy remains inconclusive, and the available evidence does not support the superiority of one strategy over another. Materials and Methods: A number of noninvasive strategies have been developed for minimizing perioperative stroke including continuous real-time monitoring of cerebral oxygenation with near-infrared spectroscopy (NIRS. The number of patients presenting with this combination (bilateral significant carotid stenosis requiring urgent cardiac surgery in any single institution will be small and hence there is a lack of large randomized studies. Results: This case series describes our early experience with NIRS in a select group of patients with significant bilateral carotid stenosis undergoing urgent cardiac surgery (n = 8. In contrast to other studies, this series is a single surgeon, single center study, where the entire surgery (both distal ends and proximal ends was performed during single aortic clamp technique, which effectively removes several confounding variables. NIRS monitoring led to the early recognition of decreased cerebral oxygenation, and corrective steps (increased cardiopulmonary bypass flow, increased pCO 2 , etc., were taken. Conclusion: The study shows good clinical outcome with the use of NIRS. This is our "work in progress," and we aim to conduct a larger study.

  1. Novel Local Calibration Method for Chemical Oxygen Demand Measurements by Using UV-Vis Spectrometry

    Science.gov (United States)

    Yingtian, Hu; Chao, Liu; Xiaoping, Wang

    2017-05-01

    In recent years, ultraviolet-visible spectroscopy has been widely used for chemical oxygen demand (COD) measurements of water. However, chemical compositions of substance in different water samples can cause measurement deviations, so a local calibration is needed. In this study, a novel local calibration method is proposed. The absorption spectra of COD standard solutions and wastewater samples taken from four factories were collected. We analyzed the impact of chemical compositions of substance in different water samples and extracted the morphology features of their absorptive spectra for recognition models. Furthermore, we calculated the local calibration parameters of the four categories of real water samples by specific modification based on the ability of light absorption in various water environments. After the process of local calibration, the root mean square errors (RMSEs) of the predictions were very small, which highlights the potential of this method for improving the accuracy and adaptability of COD measurements based on ultraviolet-visible spectrum.

  2. Soft Measurement Modeling Based on Chaos Theory for Biochemical Oxygen Demand (BOD

    Directory of Open Access Journals (Sweden)

    Junfei Qiao

    2016-12-01

    Full Text Available The precision of soft measurement for biochemical oxygen demand (BOD is always restricted due to various factors in the wastewater treatment plant (WWTP. To solve this problem, a new soft measurement modeling method based on chaos theory is proposed and is applied to BOD measurement in this paper. Phase space reconstruction (PSR based on Takens embedding theorem is used to extract more information from the limited datasets of the chaotic system. The WWTP is first testified as a chaotic system by the correlation dimension (D, the largest Lyapunov exponents (λ1, the Kolmogorov entropy (K of the BOD and other water quality parameters time series. Multivariate chaotic time series modeling method with principal component analysis (PCA and artificial neural network (ANN is then adopted to estimate the value of the effluent BOD. Simulation results show that the proposed approach has higher accuracy and better prediction ability than the corresponding modeling approaches not based on chaos theory.

  3. A modified method for estimation of chemical oxygen demand for samples having high suspended solids.

    Science.gov (United States)

    Yadvika; Yadav, Asheesh Kumar; Sreekrishnan, T R; Satya, Santosh; Kohli, Sangeeta

    2006-03-01

    Determination of chemical oxygen demand (COD) of samples having high suspended solids concentration such as cattle dung slurry with open reflux method of APHA-AWWA-WPCF did not give consistent results. This study presents a modification of the open reflux method (APHA-AWWA-WPCF) to make it suitable for samples with high percentage of suspended solids. The new method is based on a different technique of sample preparation, modified quantities of reagents and higher reflux time as compared to the existing open reflux method. For samples having solids contents of 14.0 g/l or higher, the modified method was found to give higher value of COD with much higher consistency and accuracy as compared to the existing open reflux method.

  4. Study on Determination of Chemical Oxygen Demand in Water with Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong-Hai; DING Hong-Chun; FANG Yan-Ju; XIAN Yue-Zhong; JIN Li-Tong

    2007-01-01

    A new method for determining chemical oxygen demand (COD) value in water using ion chromatography coupled with nano TiO2-K2S2O8 co-existing system was described. The photocatalytic oxidation system and nano TiO2-K2S2O8 co-existing system could degrade the organic compounds in water. All sulfur-containing species in the reactive solution were eventually transformed to sulfate which could be determined by conductivity detector in ion chromatography. The change of conductivity of sulfate was proportional to COD value. The optimal experimental conditions and the mechanism of the detection were discussed. The application range was 10.0-300.0 mg·L -1 and the lowest limit of detection was 3.5 mg·L -1. It was considered that the value obtained could be reliably correlated with the COD value obtained using the conventional methods.

  5. Chemical Oxygen Demand of Seawater Determined with a Microwave Heating Method

    Institute of Scientific and Technical Information of China (English)

    LIU Li; JI Hongwei; LIU Ying; XIN Huizhen

    2005-01-01

    This paper investigates a microwave heating method for the determination of chemical oxygen demand (COD) in seawater. The influences of microwave-power, heating time and standard substances on the results are studied. Using the proposed method, we analyzed the glucose standard solution, the coefficient of variation being less than 2%. Compared with the traditional electric stove heating method, the results of F-test and T-test showed that there was no significant difference between the two methods, but the microwave method had slightly higher precision and reproducibility than the electric stove method. With the microwave heating method, several seawater samples from Jiaozhou Bay and the South Yellow Sea were also analyzed. The recovery was between 97.5% and 104.3%. This new method has the advantages of shortening the heating time, improving the working efficiency and having simple operation and therefore can be used to analyze the COD in seawater.

  6. Improvement of the analysis of the biochemical oxygen demand (BOD) of Mediterranean seawater by seeding control.

    Science.gov (United States)

    Simon, F Xavier; Penru, Ywann; Guastalli, Andrea R; Llorens, Joan; Baig, Sylvie

    2011-07-15

    Biochemical oxygen demand (BOD) is a useful parameter for assessing the biodegradability of dissolved organic matter in water. At the same time, this parameter is used to evaluate the efficiency with which certain processes remove biodegradable natural organic matter (NOM). However, the values of BOD in seawater are very low (around 2 mgO(2)L(-1)) and the methods used for its analysis are poorly developed. The increasing attention given to seawater desalination in the Mediterranean environment, and related phenomena such as reverse osmosis membrane biofouling, have stimulated interest in seawater BOD close to the Spanish coast. In this study the BOD analysis protocol was refined by introduction of a new step in which a critical quantity of autochthonous microorganisms, measured as adenosine triphosphate, is added. For the samples analyzed, this improvement allowed us to obtain reliable and replicable BOD measurements, standardized with solutions of glucose-glutamic acid and acetate. After 7 days of analysis duration, more than 80% of ultimate BOD is achieved, which in the case of easily biodegradable compounds represents nearly a 60% of the theoretical oxygen demand. BOD(7) obtained from the Mediterranean Sea found to be 2.0±0.3 mgO(2)L(-1) but this value decreased with seawater storage time due to the rapid consumption of labile compounds. No significant differences were found between two samples points located on the Spanish coast, since their organic matter content was similar. Finally, the determination of seawater BOD without the use of inoculum may lead to an underestimation of BOD.

  7. Oxygen demand of aircraft and airfield pavement deicers and alternative freezing point depressants

    Science.gov (United States)

    Corsi, Steven R.; Mericas, Dean; Bowman, George

    2012-01-01

    Aircraft and pavement deicing formulations and other potential freezing point depressants were tested for biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Propylene glycol-based aircraft deicers exhibited greater BOD5 than ethylene glycol-based aircraft deicers, and ethylene glycol-based products had lower degradation rates than propylene glycol-based products. Sodium formate pavement deicers had lower COD than acetate-based pavement deicers. The BOD and COD results for acetate-based pavement deicers (PDMs) were consistently lower than those for aircraft deicers, but degradation rates were greater in the acetate-based PDM than in aircraft deicers. In a 40-day testing of aircraft and pavement deicers, BOD results at 20°C (standard) were consistently greater than the results from 5°C (low) tests. The degree of difference between standard and low temperature BOD results varied among tested products. Freshwater BOD test results were not substantially different from marine water tests at 20°C, but glycols degraded slower in marine water than in fresh water for low temperature tests. Acetate-based products had greater percentage degradation than glycols at both temperatures. An additive component of the sodium formate pavement deicer exhibited toxicity to the microorganisms, so BOD testing did not work properly for this formulation. BOD testing of alternative freezing point depressants worked well for some, there was little response for some, and for others there was a lag in response while microorganisms acclimated to the freezing point depressant as a food source. Where the traditional BOD5 test performed adequately, values ranged from 251 to 1,580 g/kg. Where the modified test performed adequately, values of BOD28 ranged from 242 to 1,540 g/kg.

  8. Monitoring cerebral oxygen saturation during cardiopulmonary bypass using near-infrared spectroscopy: the relationships with body temperature and perfusion rate

    Science.gov (United States)

    Teng, Yichao; Ding, HaiShu; Gong, Qingcheng; Jia, Zaishen; Huang, Lan

    2006-03-01

    During cardiopulmonary bypass (CPB) because of weak arterial pulsation, near-IR spectroscopy (NIRS) is almost the only available method to monitor cerebral oxygenation noninvasively. Our group develops a NIRS oximeter to monitor regional cerebral oxygenation especially its oxygen saturation (rScO2). To achieve optimal coupling between the sensor and human brain, the distances between the light source and the detectors on it are properly chosen. The oximeter is calibrated by blood gas analysis, and the results indicate that its algorithm is little influenced by either background absorption or overlying tissue. We used it to measure the rScO2 of 15 patients during CPB. It is shown that rScO2 is negatively correlated with body temperature and positively with perfusion rate. There are two critical stages during CPB when rScO2 might be relatively low: one is the low-perfusion-rate stage, the other is the early rewarming stage. During cooling, the changes of total hemoglobin concentration (CtHb) compared with its original value is also monitored. It is shown that CtHb decreases to a small extent, which may mainly reflect cerebral vasoconstriction induced by cooling. All these results indicate that NIRS can be used to monitor cerebral oxygenation to protect cerebral tissue during CPB.

  9. Cerebral blood flow response to functional activation

    DEFF Research Database (Denmark)

    Paulson, Olaf B; Hasselbalch, Steen G; Rostrup, Egill

    2010-01-01

    Cerebral blood flow (CBF) and cerebral metabolic rate are normally coupled, that is an increase in metabolic demand will lead to an increase in flow. However, during functional activation, CBF and glucose metabolism remain coupled as they increase in proportion, whereas oxygen metabolism only...

  10. Peroxone mineralization of chemical oxygen demand for direct potable water reuse: Kinetics and process control.

    Science.gov (United States)

    Wu, Tingting; Englehardt, James D

    2015-04-15

    Mineralization of organics in secondary effluent by the peroxone process was studied at a direct potable water reuse research treatment system serving an occupied four-bedroom, four bath university residence hall apartment. Organic concentrations were measured as chemical oxygen demand (COD) and kinetic runs were monitored at varying O3/H2O2 dosages and ratios. COD degradation could be accurately described as the parallel pseudo-1st order decay of rapidly and slowly-oxidizable fractions, and effluent COD was reduced to below the detection limit (water, and a relationship is proposed and demonstrated to estimate the pseudo-first order rate constant for design purposes. At this O3/H2O2 mass ratio, ORP and dissolved ozone were found to be useful process control indicators for monitoring COD mineralization in secondary effluent. Moreover, an average second order rate constant for OH oxidation of secondary effluent organics (measured as MCOD) was found to be 1.24 × 10(7) ± 0.64 × 10(7) M(-1) S(-1). The electric energy demand of the peroxone process is estimated at 1.73-2.49 kW h electric energy for removal of one log COD in 1 m(3) secondary effluent, comparable to the energy required for desalination of medium strength seawater. Advantages/disadvantages of the two processes for municipal wastewater reuse are discussed.

  11. Protozoan biomass relation to nutrient and chemical oxygen demand removal in activated sludge mixed liquor.

    Science.gov (United States)

    Akpor, Oghenerobor B; Momba, Maggy N B; Okonkwo, Jonathan O

    2008-08-01

    The relationship between biomass concentration to nutrient and chemical oxygen demand (COD) removal in mixed liquor supplemented with sodium acetate was investigated, using three protozoan isolates and three different initial biomass concentrations (10(1), 10(2) and 10(3) cells/mL). The study was carried out in a shaking flask environment at a shaking speed of 100 rpm for 96 h at 25 degrees C. Aliquot samples were taken periodically for the determination of phosphate, nitrate, COD and dissolved oxygen, using standard methods. The results revealed remarkable phosphate removal of 82-95% at biomass concentration of 10(3)cells/mL. A high nitrate removal of over 87% was observed at all initial biomass concentration in mixed liquor. There was an observed COD increase of over 50% in mixed liquor in at the end of 96-h incubation and this was irrespective of initial biomass concentration used for inoculation. The study shows the trend in nutrient and COD removal at different biomass concentrations of the test isolates in mixed liquor.

  12. Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

    2004-05-01

    Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

  13. Effects of transection of cervical sympathetic trunk on cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Liangzhi Xiong; Yongxia Shi; Feng Xiao; Qingxiu Wang

    2008-01-01

    BACKGROUND: Stellate ganglion block (SGB) plays a protective role on the brain, but the precise mechanism of action is not clear.OBJECTIVE: To simulate SGB by transection of the cervical sympathetic trunk (TCST) and to investigate the TCST effects on changes in cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury.DESIGN, TIME AND SETTING: A complete randomized control animal experiment was performed at the Institute of Neurological Diseases of Taihe Hospital, Yunyang Medical College from February to December 2005.MATERIALS: A total of 101 healthy Wistar rats, weighing 280-320g, of both genders, aged 17-18 weeks, were used in this study. 2,3,5-triphenyltetrazolium chloride (TTC) was purchased from Changsha Hongyuan Biological Company. Superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO) assay kits were provided by Nanjing Jiancheng Bioengineering Institute.METHODS: Rats were randomly divided into a TCST group, a model group and a sham operation group. Successful models were included in the final analysis, with at least 20 rats in each group. After TCST, rat models of focal cerebral ischemia/reperfusion injury were established in the TCST group by receiving middle cerebral artery occlusion (MCAO) by the intraluminal suture method for 2 hours, followed by 24 hours of reperfusion. Rat models of focal cerebral ischemia/reperfusion injury were made in the model group. Rats in the sham operation group underwent experimental procedures as for the model group, threading depth of 10mm, and middle cerebral artery was not ligated.MAIN OUTCOME MEASURES: Brain tissue sections of ten rats from each group were used to measure cerebral infarct volume by TTC staining. Brain tissue homogenate of another ten rats from each group was used to detect SOD activities, MDA contents and NO levels. Rat neurological function was assessed by neurobehavioral measures.RESULTS: Cerebral infarct volume was bigger in the

  14. Sediment oxygen demand in the Tualatin River basin, Oregon, 1992-96

    Science.gov (United States)

    Rounds, Stewart; Doyle, M.C.

    1997-01-01

    Sediment oxygen demand (SOD) rates were measured by U.S. Geological Survey (USGS) personnel at 20 stream sites in the Tualatin River Basin from 1992 through 1996 as part of an investigation into the sources and sinks of dissolved oxygen in the Tualatin River. During the low-flow summer periods of 1992 through 1994, 97 measurements were collected at 9 sites on the main stem of the river between river miles (RMs) 5.5 and 43.2. During the low-flow summer periods of 1995 and 1996, 28 measurements of SOD were collected at 11 sites on 8 tributaries of the Tualatin River. All SOD rates were measured with in-situ benthic chambers designed to monitor the loss of dissolved oxygen in a known volume of water circulating above a known area of minimally disturbed stream sediment. For main-stem Tualatin River sites, the observed SOD rate ranged from 0.6 to 4.4 grams of oxygen per square meter per day (g/m 2 d) with a median of 2.3 g/m 2 d. In the tributaries, the measured SOD rate ranged from 0.2 to 10.9 with a median of 3.6 g/m 2 d. These rates are in the range of those reported for other sites in Oregon and across the United States. Most of the variation in the measured SOD rates was likely due to heterogeneities in the bed sediment. Statistical comparisons show that the rates measured at the tributary sites are significantly larger than those measured in the main stem. Within the main stem, the rates measured at sites in the meander reach of the river were not significantly different from those measured in the reservoir reach. Similarly, no difference was found when the sites affected by the cycle of phytoplankton bloom and die-off were compared to those unaffected by phytoplankton. Only one site on the main stem, RM 5.5, was found to have an SOD rate that was significantly higher than that found at the other main-stem sites. Algal detritus may contribute to the elevated rate at that site, but other factors such as the rate of sediment accumulation could also account for the

  15. Liposome-encapsulated hemoglobin reduces the size of cerebral infarction in rats: effect of oxygen affinity.

    Science.gov (United States)

    Fukumoto, Dai; Kawaguchi, Akira T; Haida, Munetaka; Yamano, Mariko; Ogata, Yoshitaka; Tsukada, Hideo

    2009-02-01

    Liposome-encapsulated hemoglobin (LEH) with a low oxygen affinity (l-LEH, P(50) = 45 mm Hg) was found to be protective in the rodent and primate models of ischemic stroke. This study investigated the role of LEH with a high O(2) affinity (h-LEH, P(50) = 10 mm Hg) in its protective effect on brain ischemia. The extent of cerebral infarction was determined 24 h after photochemically induced thrombosis of the middle cerebral artery from the integrated area of infarction detected by triphenyltetrazolium chloride staining in rats receiving various doses of h-LEH as well as l-LEH. Both h-LEH and l-LEH significantly reduced the extent of cortical infarction. h-LEH remained protective at a lower concentration (minimal effective dose [MED]: 0.08 mL/kg) than l-LEH (MED: 2 mL/kg) in the cortex. h-LEH reduced the infarction extent in basal ganglia as well (MED: 0.4 mL/kg), whereas l-LEH provided no significant protection. h-LEH provided better protection than l-LEH. The protective effect of both high- and low-affinity LEH may suggest the importance of its small particle size (230 nm) as compared to red blood cells. The superiority of h-LEH over l-LEH supports an optimal O(2) delivery to the ischemic penumbra as the mechanism of action in protecting against brain ischemia and reperfusion.

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

    Science.gov (United States)

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

    2017-08-01

    To evaluate the effects of acute arterial carbon dioxide partial pressure changes on cerebral oxygenation and electrical activity in infants born preterm. This retrospective observational study included ventilated infants born preterm with acute fluctuations of continuous end-tidal CO2 (etCO2) as a surrogate marker for arterial carbon dioxide partial pressure, during the first 72 hours of life. Regional cerebral oxygen saturation and fractional tissue oxygen extraction were monitored with near-infrared spectroscopy. Brain activity was monitored with 2-channel electroencephalography. Spontaneous activity transients (SATs) rate (SATs/minute) and interval between SATs (in seconds) were calculated. Ten-minute periods were selected for analysis: before, during, and after etCO2 fluctuations of ≥5  mm Hg. Thirty-eight patients (mean ± SD gestational age of 29 ± 1.8 weeks) were included, with 60 episodes of etCO2 increase and 70 episodes of etCO2 decrease. During etCO2 increases, brain oxygenation increased (regional cerebral oxygen saturation increased, fractional tissue oxygen extraction decreased; P carbon dioxide partial pressure that may be harmful to the neonatal brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Smoking normalizes cerebral blood flow and oxygen consumption after 12-hour abstention

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Gjedde, Albert; Imamirad, Nasrin

    2015-01-01

    measurements of cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) in 12 smokers who had refrained from smoking overnight, and in a historical group of nonsmokers, testing the prediction that overnight abstinence results in widespread, coupled reductions of CBF and CMRO2. At the end......Acute nicotine administration stimulates [14C]deoxyglucose trapping in thalamus and other regions of rat brain, but acute effects of nicotine and smoking on energy metabolism have rarely been investigated in human brain by positron emission tomography (PET). We obtained quantitative PET...... of the abstention period, global grey-matter CBF and CMRO2 were both reduced by 17% relative to nonsmokers. At 15 minutes after renewed smoking, global CBF had increased insignificantly, while global CMRO2 had increased by 11%. Regional analysis showed that CMRO2 had increased in the left putamen and thalamus...

  18. Optical measurement of cerebral hemodynamics and oxygen metabolism in neonates with congenital heart defects

    Science.gov (United States)

    Durduran, Turgut; Zhou, Chao; Buckley, Erin M.; Kim, Meeri N.; Yu, Guoqiang; Choe, Regine; Gaynor, J. William; Spray, Thomas L.; Durning, Suzanne M.; Mason, Stefanie E.; Montenegro, Lisa M.; Nicolson, Susan C.; Zimmerman, Robert A.; Putt, Mary E.; Wang, Jiongjiong; Greenberg, Joel H.; Detre, John A.; Yodh, Arjun G.; Licht, Daniel J.

    2010-05-01

    We employ a hybrid diffuse correlation spectroscopy (DCS) and near-infrared spectroscopy (NIRS) monitor for neonates with congenital heart disease (n=33). The NIRS-DCS device measured changes during hypercapnia of oxyhemoglobin, deoxyhemoglobin, and total hemoglobin concentrations; cerebral blood flow (rCBFDCS); and oxygen metabolism (rCMRO2). Concurrent measurements with arterial spin-labeled magnetic resonance imaging (rCBFASL-MRI, n=12) cross-validate rCBFDCS against rCBFASL-MRI, showing good agreement (R=0.7, p=0.01). The study demonstrates use of NIRS-DCS on a critically ill neonatal population, and the results indicate that the optical technology is a promising clinical method for monitoring this population.

  19. ADRB2 gly16gly Genotype, Cardiac Output, and Cerebral Oxygenation in Patients Undergoing Anesthesia for Abdominal Aortic Aneurysm Surgery

    DEFF Research Database (Denmark)

    Staalso, Jonatan Myrup; Rokamp, Kim Zillo; Olesen, Niels D.

    2016-01-01

    BACKGROUND: Gly16arg polymorphism of the adrenergic [beta]2-receptor is associated with the elevated cardiac output (Q) in healthy gly16-homozygotic subjects. We questioned whether this polymorphism also affects Q and regional cerebral oxygen saturation (SCO2) during anesthesia in vascular surgic...

  20. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  1. Hyperbaric oxygen therapy for cerebral blood flow and electroencephalogram in patients with acute cerebral infarction Choice for therapeutic occasion

    Institute of Scientific and Technical Information of China (English)

    Lei Chen; Fei Li; Dexiang Gu

    2007-01-01

    BACKGROUND: Hyperbaric oxygen (HBO) therapy increases blood oxygen content, changes cerebral blood flow (CBF) and cerebral metabolism. Its therapeutic effects on cerebrovascular disease have been fully confirmed, but the occasion for HBO therapy is still unclear.OBJECTIVE: To observe the therapeutic effects of HBO therapy at different time on CBF and electroencephalogram (EEG) in patients with acute cerebral infarction (CI).DESIGN: Randomized controlled trial.SETTING: Department of Neurology, Shidong Hospital, Yangpu District of Shanghai.PARTICIPANTS: Ninety-six inpatients with acute CI, admitted to Department of Neurology, Shidong Hospital, Yangpu District of Shanghai from January 2001 to December 2006, were involved in this experiment. The involved participants met the diagnosis criteria of acute CI and confirmed by skull CT or MRI. They all were patients with moderate CI (16- 30 points) according to neurologic deficit score formulated by Chinese Medical Association. Informed consents of detected items and therapeutic regimen were obtained from all the involved participants. They were randomized into two groups with 48 in each:early-stage treatment group and advanced-stage treatment group. Among the 48 patients in the early-stage treatment group, 21 male and 27 female, aged 53 -68 years, 22 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 16 with multiple infarction, 27 accompanied with hypertension and 2 accompanied with diabetes mellitus. Among the 48 patients in the advanced-stage treatment group, 23 male and 25 female, aged 52 - 71 years, 25 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 12 with multiple infarction, 1 with brain stem infarction, 28 accompanied with hypertension and 1 accompanied with diabetes mellitus.METHODS: After admission, patients of two groups received routine drug treatment. ① Patients in the early-stage treatment group and advanced-stage treatment group began to

  2. A comparison of pulse oximetry and cerebral oxygenation in children with severe sleep apnea-hypopnea syndrome: a pilot study.

    Science.gov (United States)

    Olmo Arroyo, Jorge; Khirani, Sonia; Amaddeo, Alessandro; Griffon, Lucie; De Sanctis, Livio; Pouard, Philippe; Fauroux, Brigitte

    2017-05-31

    Near infrared spectroscopy (NIRS) has been used to assess the impact of obstructive sleep apnea-hypopnea syndrome (OSAHS) on cerebral oxygenation. However, the relationship between the variations in the cerebral tissue oxygen saturation (ΔTOI) and pulse oximetry (ΔSpO2 ) has not been assessed in children with OSAHS. Consecutive clinically stable children with severe OSAHS [apnea-hypopnea index (AHI) >15 events h(-1) ] diagnosed during a night-time polygraphy with simultaneous recording of cerebral oxygenation with NIRS (NIRO-200NX, Hamamatsu Photonics KK) were included between September 2015 and June 2016. Maximal ΔSpO2 (SpO2 drop from the value preceding desaturation to nadir) and concomitant variations in transcutaneous carbon dioxide (ΔPtcCO2 ), maximal ΔTOI and maximal variations in cerebral oxygenated (O2 Hb) and deoxygenated (HHb) haemoglobin were reported. The relationships between ΔSpO2 , ΔPtcCO2 and ΔTOI, ΔO2 Hb and ΔHHb were investigated. The data from five children (three boys, aged 9.6 ± 6.7 years, AHI 16-91 events h(-1) ) were analysed. Strong correlations were found between ΔSpO2 and ΔTOI (r = 0.887, P < 0.001), but also with ΔO2 Hb and ΔHHb with a particular pattern in the youngest child with a dark skin pigmentation. Mean ΔSpO2 was 20 ± 17% and mean ΔTOI was 8 ± 7%. Maximal ΔSpO2 of approximately 70% were coupled with ΔTOI of no more than 35%. ΔPtcCO2 correlated only weakly with the cerebral oxygenation indexes. This pilot study shows a strong relationship between pulse oximetry and cerebral oxygenation in children with OSAHS, with lower changes in TOI compared to SpO2 . Future studies should address the clinical impact of respiratory events on cerebral oxygenation and its consequences. © 2017 European Sleep Research Society.

  3. Cerebral oxygenation and processed EEG response to clamping and shunting during carotid endarterectomy under general anesthesia.

    Science.gov (United States)

    Perez, William; Dukatz, Christopher; El-Dalati, Sami; Duncan, James; Abdel-Rasoul, Mahmoud; Springer, Andrew; Go, Michael R; Dzwonczyk, Roger

    2015-12-01

    Clamping and shunting during carotid endarterectomy (CEA) surgery causes changes in cerebral blood flow. The purpose of this study was to assess and compare, side by side, the cerebral oxygenation (rSO2) and processed electroencephalogram (EEG) response bilaterally to carotid artery clamping and shunting in patients undergoing CEA under general anesthesia. With institutional approval and written informed consent, patients undergoing CEA under general anesthesia and routine carotid artery shunting were recorded bilaterally, simultaneously and continuously with an rSO2 and processed EEG monitor. The response of the monitors during carotid artery clamping and shunting were assessed and compared between monitors and bilaterally within each monitor. Sixty-nine patients were included in the study. At clamping the surgical-side and contralateral-side rSO2 dropped significantly below the baseline incision value (-17.6 and -9.4% respectively). After shunting, the contralateral-side rSO2 returned to baseline while the surgical-side rSO2 remained significantly below baseline (-9.0%) until the shunt was removed following surgery. At clamping the surgical-side and contralateral-side processed EEG also dropped below baseline (-19.9 and -20.6% respectively). However, following shunt activation, the processed EEG returned bilaterally to baseline. During the course of this research, we found the rSO2 monitor to be clinically more robust (4.4% failure rate) than the processed EEG monitor (20.0% failure rate). There was no correlation between the rSO2 or processed EEG changes that occurred immediately after clamping and the degree of surgical side stenosis measured pre-operatively. Both rSO2 and processed EEG respond to clamping and shunting during CEA. Cerebral oximetry discriminates between the surgical and contralateral side during surgery. The rSO2 monitor is more reliable in the real-world clinical setting. Future studies should focus on developing algorithms based on these

  4. Depressed cerebral oxygen metabolism in patients with chronic renal failure. A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Hirakata, Hideki; Kanai, Hidetoshi; Nakane, Hiroshi; Fujii, Ken-ichiro; Hirakata, Eriko; Ibayashi, Setsuro; Kuwabara, Yasuo; Deenitchna, S.S.; Fujishima, Masatoshi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences

    2001-07-01

    In order to elucidate brain oxygen metabolism in uremic patients, the regional cerebral blood flow (rCBF), oxygen extraction (rOEF) and oxygen metabolism (rCMRO{sub 2}) were measured by positron emission tomography (PET) in both 10 hemodialysis patients (HD: male [m]/female [f]=2/8, age of 49{+-}3 [SEM] years old, HD duration of 113{+-}26 months) and 13 pre-dialysis renal failure patients (CRF: m/f=10/3, age of 61{+-}2 years old, serum creatinine (SCr) of 6.3{+-}1.0 mg/dl). Data were compared with 20 non-uremic subjects (Control: m/f=7/13, age of 62{+-}2 years old, SCr of 0.9{+-}0.1 mg/dl). They had no neurological abnormalities, congestive heart failure, history of cerebrovascular accident, diabetes mellitus, or symptomatic brain lesion on magnetic resonance imaging. The age of HD was significantly younger than the other groups (p<0.02) and the hemoglobin (Hb) levels in both HD (10.5{+-}0.5 g/dl) and CRF (9.8{+-}0.9) were significantly lower than that in Control (13.3{+-}0.3) (p<0.02). In the hemisphere, rCMRO{sub 2} in both HD (1.82{+-}0.10 ml/min/100 g) and CRF (1.95{+-}0.09) showed significantly lower values as compared to Control (2.23{+-}0.05) (p<0.01, respectively). Hemispheric rCBF in HD (35.6{+-}2.1 ml/100 g/min) and in CRF (36.1{+-}2.1) were not different from that in Control (31.8{+-}1.4). Hemispheric rOEF in CRF (45.7{+-}1.6%) was significantly higher than that in Control (40.5{+-}1.2%) (p<0.02), but that in HD (43.7{+-}1.9%) did not increase significantly. These tendencies were similar in all regions of interest, especially in the cerebral cortices, but not in the cerebellum. All PET parameters in the frontal cortices tended to show the lowest value in renal failure patients. For all HD patients, rCBF in both the frontal cortex and the white matter correlated inversely with HD duration (frontal cortex: r=-0.649, p<0.05; white matter: r=-0.706, p<0.02). Based on these data, it is concluded that brain oxygen metabolism is depressed in renal failure

  5. Estimation of Biochemical Oxygen Demand Based on Dissolved Organic Carbon, UV Absorption, and Fluorescence Measurements

    Directory of Open Access Journals (Sweden)

    Jihyun Kwak

    2013-01-01

    Full Text Available Determination of 5-d biochemical oxygen demand (BOD5 is the most commonly practiced test to assess the water quality of surface waters and the waste loading. However, BOD5 is not a good parameter for the control of water or wastewater treatment processes because of its long test period. It is very difficult to produce consistent and reliable BOD5 results without using careful laboratory quality control practices. This study was performed to develop software sensors to predict the BOD5 of river water and wastewater. The software sensors were based on the multiple regression analysis using the dissolved organic carbon (DOC concentration, UV light absorbance at 254 nm, and synchronous fluorescence spectra. River water samples and wastewater treatment plant (WWTP effluents were collected at 1-hour interval to evaluate the feasibility of the software sensors. In short, the software sensors developed in this study could well predict the BOD5 of river water (r=0.78 and for the WWTP effluent (r=0.90.

  6. Removal of chemical oxygen demand from textile wastewater using a natural coagulant

    Energy Technology Data Exchange (ETDEWEB)

    Ramavandi, Bahman [Bushehr University of Medical Sciences, Bushehr (Iran, Islamic Republic of); Farjadfard, Sima [Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2014-01-15

    A biomaterial was successfully synthesized from Plantago ovata by using an FeCl{sub 3}-induced crude extract (FCE). The potential of FCE to act as a natural coagulant was tested for the pretreatment of real textile wastewater. Tests were performed to evaluate the effects of FCE quantity, salt concentration, and wastewater pH on chemical oxygen demand (COD) reduction during a coagulation/flocculation process. Experimental results indicated that the wastewater could be effectively treated by using a coagulation/flocculation process, where the BOD{sub 5}/COD ratio of the effluent was improved to 0.48. A low coagulant dose, 1.5mg/L, achieved a high COD removal percentage, 89%, at operational conditions of neutral pH and room temperature. The experimental data revealed that the maximum COD removal occurred at water pH<8. Increasing the salt promoted the COD removal. The settling and filterability characteristics of the sludge were also studied. Scanning electron microscopy and energy dispersive spectroscopy studies were conducted to determine the sludge structure and composition, respectively. Overall, FCE as an eco-friendly biomaterial was revealed to be a very efficient coagulant and a promising option for the removal of COD from wastewaters.

  7. Influence of Chemical Oxygen Demand Concentrations on Anaerobi Ammonium Oxidation by Granular Sludge From EGSB Reactor

    Institute of Scientific and Technical Information of China (English)

    JING KANG; JIAN-LONG WANG

    2006-01-01

    Objective To investigate the effect of chemical oxygen demand (COD) concentrations on the anaerobic ammonium oxidation (ANAMMOX). Methods An Expanded Granular Sludge Bed (EGSB) reactor was used to cultivate the granular sludge and to perform the ANAMMOX reaction in the bench scale experiment. NH4+-N and NO2--N were measured by usingcolorimetric method. NO3--N was analyzed by using the UV spectrophotometric method. COD measurement was based on digestion with potassium dichromate in concentrated sulphuric acid. Results When the COD concentrations in the reactors were 0 mg/L, 200 mg/L, 350 mg/L, and 550 mg/L, respectively, the NH4+-N removal efficiency was 12.5%, 14.2%, 14.3%, and 23.7%; the removal amount of NO2--N was almost the same; the nitrate removal efficiency was 16.8%, 94.5%, 86.6%, and 84.2% and TN removal efficiency was 16.3%, 50.7%, 46.9%, and 50.4%, moreover, the COD removal efficiency concentrations have a significant influence on anaerobic ammonium oxidation by granular sludge.

  8. A portable photoelectrochemical probe for rapid determination of chemical oxygen demand in wastewaters.

    Science.gov (United States)

    Zhang, Shanqing; Li, Lihong; Zhao, Huijun

    2009-10-15

    A photoelectrochemical probe for rapid determination of chemical oxygen demand (COD) is developed using a nanostructured mixed-phase TiO2 photoanode, namely PeCOD probe. A UV-LED light source and a USB mircroelectrochemical station are powered and controlled by a laptop computer, which makes the probe portable for onsite COD analyses. The photoelectrochemical measurement of COD was optimized in terms of light intensity, applied bias, and pH. Under the optimized conditions, the net steady state currents originated from the oxidation of organic compounds were found to be directly proportional to COD concentrations. A practical detection limit of 0.2 ppm COD and a linear range of 0-120 ppm COD were achieved. The analytical method using the portable PeCOD probe has the advantages of being rapid, low cost, robust, user-friendly, and environmental friendly. It has been successfully applied to determine the COD values of the synthetic samples consisting of potassium hydrogen phthalate, D-glucose, glutamic acid, glutaric acid, succinic acid, and malonic acid, and real samples from various industries, such as bakery, oil and grease manufacturer, poultry, hotel, fine food factory, and fresh food producer, commercial bread manufacturer. Excellent agreement between the proposed method and the conventional COD method (dichromate) was achieved.

  9. A Novel Biosensor for the Rapid Determination of Biochemical Oxygen Demand

    Institute of Scientific and Technical Information of China (English)

    JIN-SONG CHEN; LI-SHENG ZHANG; JIAN-LONG WANG

    2007-01-01

    Objective To investigate the function of a novel biosensor used for the rapid determination of biochemical oxygen demand (BOD) which is developed by our research group based on suspended immobilized microbial cell system in a completely mixed determining chamber as a substitute of the traditional membrane system. Methods Activated sludge was immobilized by PVA gel and used as a bio-sensing element. The novel biosensor was used to measure the short time BOD value and the conventional cultivation method was used for BOD5 measurement. Results A linear relationship was observed for the difference between the current and the concentration of glucose-glutamic acid (GGA) solution below 200mg/L with a correlation coefficient of 0.995. The optimal response of the sensor was obtained at pH 7.0 and 30℃. The sensor response was within 15 min and was reproducible within ±5% of the mean in a series of eight samples containing 75 mg/L BOD using standard GGA solution. The novel sensor response was found to be fairly constant over a period of 0days, with ±5% fluctuations. Conclusion A relatively good agreement is found between BOD estimated by the novel BOD biosensor and that determined by the conventional 5-day BOD method. This novel BOD biosensor has good sensitivity, stability and reproducibility.

  10. Environmental capacity of chemical oxygen demand in the Bohai Sea: modeling and calculation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xixi; WANG Xiulin; SHI Xiaoyong; LI Keqiang; DING Dongsheng

    2011-01-01

    A three-dimensional advection-diffusion model coupled with the degradation process is established for describing the transport of chemical oxygen demand (COD). Comparison of the simulated distribution of COD at the surface in the Bohai Sea in August, 2001 with field observations, shows that the model simulates the dataset reasonably well. The Laizhou Bay, Bohai Bay, and Liaodong Bay were contaminated heavily near shore. Based on the optimal discharge flux method, the Environmental Capacity (EC) and allocated capacities of COD in the Bohai Sea are calculated. For seawater of Grades I to IV of the Chinese National Standard, the ECs of COD in the Bohai Sea were 77×104t/a, 116×l04t/a, 154×l04t/a and 193×104t/a, respectively. The Huanghe (Yellow) River pollutant discharge accounted for the largest percentage of COD at 14.3%, followed by that of from the Liugu River (11.5%), and other nine local rivers below 10%. The COD level in 2005 was worse than that of Grade II seawater and was beyond the environmental capacity. In average, 35% COD reduction is called to meet the standard of Grade I seawater.

  11. Development and characterization of microbial biosensors for evaluating low biochemical oxygen demand in rivers.

    Science.gov (United States)

    Chee, Gab-Joo

    2013-12-15

    Five microorganisms were used to construct a biosensor for the evaluation of low biochemical oxygen demand (BOD) in rivers. Characterization and comparison of BOD biosensors were performed using two standard solutions: glucose and glutamic acid (GGA) and artificial wastewater (AWW). Pseudomonas putida SG10 demonstrated the best response when using AWW. Trichosporon cutaneum IFO10466, however, had an extremely poor response. When evaluating the biosensor response to each component of AWW, all of the microorganisms except T. cutaneum displayed the highest response to tannic acid. In a comparison of the two standard solutions for all the microorganisms, the biosensor responses of GGA were approximately three times higher than those of AWW were. In the BOD determination of environmental samples, the biosensor BOD values evaluated using AWW were slightly lower or equivalent to BOD5 values, whereas the biosensor BOD values evaluated using GGA were considerably lower. These results suggest that GGA is suitable for the detection of high BOD in industrial wastewaters and factory effluents, while AWW is suitable for the detection of low BOD in rivers.

  12. Chemometrics-assisted spectrophotometry method for the determination of chemical oxygen demand in pulping effluent.

    Science.gov (United States)

    Chen, Honglei; Chen, Yuancai; Zhan, Huaiyu; Fu, Shiyu

    2011-04-01

    A new method has been developed for the determination of chemical oxygen demand (COD) in pulping effluent using chemometrics-assisted spectrophotometry. Two calibration models were established by inducing UV-visible spectroscopy (model 1) and derivative spectroscopy (model 2), combined with the chemometrics software Smica-P. Correlation coefficients of the two models are 0.9954 (model 1) and 0.9963 (model 2) when COD of samples is in the range of 0 to 405 mg/L. Sensitivities of the two models are 0.0061 (model 1) and 0.0056 (model 2) and method detection limits are 2.02-2.45 mg/L (model 1) and 2.13-2.51 mg/L (model 2). Validation experiment showed that the average standard deviation of model 2 was 1.11 and that of model 1 was 1.54. Similarly, average relative error of model 2 (4.25%) was lower than model 1 (5.00%), which indicated that the predictability of model 2 was better than that of model 1. Chemometrics-assisted spectrophotometry method did not need chemical reagents and digestion which were required in the conventional methods, and the testing time of the new method was significantly shorter than the conventional ones. The proposed method can be used to measure COD in pulping effluent as an environmentally friendly approach with satisfactory results.

  13. Electrochemical treatment of rice grain-based distillery effluent: chemical oxygen demand and colour removal.

    Science.gov (United States)

    Prajapati, Abhinesh Kumar; Chaudhari, Parmesh Kumar

    2014-01-01

    The electrochemical (EC) treatment of rice grain-based distillery wastewater was carried out in a 1.5 dm3 electrolytic batch reactor using aluminium plate electrodes. With the four-plate configurations, a current density (j) of 89.3 A/m2 and pH 8 was found to be optimal, obtaining a maximum chemical oxygen demand (COD) and colour removal of 93% and 87%, respectively. The chemical dissolution of aluminium was strongly influenced by initial pH (pHi). At higher pHi (pH 9.5) anode consumption decreased while energy consumption increased. At the optimal current density 89.3 A/m2, the aluminium electrode consumption was 16.855 g/dm3 wastewater and energy consumption was 31.4 Wh/dm3 achieving a maximum COD removal of 87%. The settling and filterability characteristics ofelectrochemically treated sludge were also analysed at different pH. It was noted that treated slurry at pHi 9.5 gave best settling characteristic, which decreased with increase in pH. EC-treated effluent at pHi 8 had provided best filterability. Characteristics of scum and residues are also analysed at different pH.

  14. Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes

    Institute of Scientific and Technical Information of China (English)

    ZAYAS Pérez Teresa; GEISSLER Gunther; HERNANDEZ Fernando

    2007-01-01

    The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculatio and advanced oxidation processes(AOP)had been studied.The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H202,UVO3 and UV/H-H202/O3 processes was determined under acidic conditions.For each of these processes,different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater.Coffee wastewater is characterized by a high chemical oxygen demand(COD)and low total suspended solids.The outcomes of coffee wastewater reeatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD,color,and turbidity.It was found that a reductiOn in COD of 67%could be realized when the coffee wastewater was treated by chemical coagulation-flocculatlon witll lime and coagulant T-1.When coffee wastewater was treated by coagulation-flocculation in combination with UV/H202,a COD reduction of 86%was achieved,although only after prolonged UV irradiation.Of the three advanced oxidation processes considered,UV/H202,uv/03 and UV/H202/03,we found that the treatment with UV/H2O2/O3 was the most effective,with an efficiency of color,turbidity and further COD removal of 87%,when applied to the flocculated coffee wastewater.

  15. Using gas flux to estimate biological and chemical sediment oxygen demand in oil sands-affected wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Gardner Costa, J.; Slama, C.; Ciborowski, J. [Windsor Univ., ON (Canada)

    2010-07-01

    The constituents of oil sands process-affected (OSPM) wetlands include high salinity, conductivity and naphthenic acid concentrations. These constituents are expected to strain microbial communities and change methane and carbon dioxide flux rates as well as sediment oxygen consumption compared to fresher, reference wetland sites. Four OSPM and 4 reference wetlands were examined during the summers of 2009 and 2010 to determine if carbon loss in the form of sediment-associated microbial respiration differs between OSPM and reference wetlands. The study showed that OSPM wetlands release about 10 times less methane than reference wetlands. Sediment oxygen demand (SOD) was measured in 2009 and gas flux estimates of carbon dioxide were used to estimate biological sediment oxygen consumption (BSOC). Chemical sediment oxygen demand (CSOD) was estimated by subtracting BSOC from total SOD. SOD rates were found to be two times higher in OSPM wetlands than reference. CSOD was higher than biologically consumed oxygen for both wetland classes. Although microbial activity in OSPM wetlands may be lower, more oxygen is consumed in OSPM than in reference wetlands. The reclamation of boreal wetlands in the Alberta Athabasca region requires carbon accrual. Less microbial activity may promote carbon accumulation within OSPM wetlands. However, the wetland's sediment layer may have less organic input as a result of high chemical oxygen consumption because it limits benthos respiration.

  16. Initial clinical experience with near-infrared spectroscopy in assessing cerebral tissue oxygen saturation in cerebral vasospasm before and after intra-arterial verapamil injection.

    Science.gov (United States)

    Meng, Lingzhong; Settecase, Fabio; Xiao, Jifang; Yu, Zhaoxia; Flexman, Alana M; Higashida, Randall T

    2016-04-01

    Cerebral vasospasm is a devastating complication after subarachnoid hemorrhage. The use of cerebral tissue oxygen saturation (SctO2) to non-invasively assess changes in cerebral tissue perfusion induced by intra-arterial (IA) verapamil treatment has not been described to our knowledge. A total of 21 consecutive post-craniotomy patients scheduled for possible IA verapamil treatment of cerebral vasospasm were recruited. The effect of IA verapamil injection on SctO2 being continuously monitored on both the left and right forehead was investigated. Comparisons between changes in SctO2 monitored on the ipsilateral and contralateral forehead in relationship to the side of internal carotid artery (ICA) injection were performed. A total of 47 IA verapamil injections (15 left ICA, 18 right ICA, and 14 vertebral artery injections) during 18 neurointerventional procedures in 13 patients were analyzed. IA verapamil administration led to both increases and decreases in SctO2. Changes in SctO2 ipsilateral to the ICA injection side were more pronounced (p=0.02 and 0.07 for left and right ICA injections, respectively) and favored compared to contralateral SctO2 changes. We were unable to obtain reliable measurements on the side ipsilateral to the craniotomy during four procedures in three patients, presumably secondary to pneumocephalus. The local cerebral vasodilating effect of IA verapamil injection is suggested by the differential changes in SctO2 ipsilateral and contralateral to the ICA injection side. The inconsistent changes in SctO2 and the limitations of applying cerebral oximetry in this patient population needs to be recognized.

  17. Determination of Sediment Oxygen Demand in the Ziya River Watershed, China: Based on Laboratory Core Incubation and Microelectrode Measurements.

    Science.gov (United States)

    Rong, Nan; Shan, Baoqing; Wang, Chao

    2016-02-19

    A study coupling sedimentcore incubation and microelectrode measurement was performed to explore the sediment oxygen demand (SOD) at 16 stations in the Ziya River Watershed, a severely polluted and anoxic river system in the north of China. Total oxygen flux values in the range 0.19-1.41 g/(m²·d) with an average of 0.62 g/(m²·d) were obtained by core incubations, and diffusive oxygen flux values in the range 0.15-1.38 g/(m²·d) with an average of 0.51 g/(m²·d) were determined by microelectrodes. Total oxygen flux obviously correlated with diffusive oxygen flux (R² = 0.842). The microelectrode method produced smaller results than the incubation method in 15 of 16 sites, and the diffusive oxygen flux was smaller than the total oxygen flux. Although the two sets of SOD values had significant difference accepted by the two methods via the Wilcoxon signed-rank test (p Watershed when the dissolved oxygen (DO) recovered in the overlying water.

  18. [Effects of carbon dioxide insufflation on regional cerebral oxygenation during laparoscopic surgery in children: a prospective study].

    Science.gov (United States)

    Tuna, Ayca Tas; Akkoyun, Ibrahim; Darcin, Sevtap; Palabiyik, Onur

    2016-01-01

    Laparoscopic surgery has become a popular surgical tool when compared to traditional open surgery. There are limited data on pediatric patients regarding whether pneumoperitoneum affects cerebral oxygenation although end-tidal CO2 concentration remains normal. Therefore, this study was designed to evaluate the changes of cerebral oxygen saturation using near-infrared spectroscope during laparoscopic surgery in children. The study comprised forty children who were scheduled for laparoscopic (Group L, n=20) or open (Group O, n=20) appendectomy. Hemodynamic variables, right and left regional cerebral oxygen saturation (RrSO2 and LrSO2), fraction of inspired oxygen, end-tidal carbon dioxide pressure (PETCO2), peak inspiratory pressure (Ppeak), respiratory minute volume, inspiratory and end-tidal concentrations of sevoflurane and body temperature were recorded. All parameters were recorded after anesthesia induction and before start of surgery (T0, baseline), 15min after start of surgery (T1), 30min after start of surgery (T2), 45min after start of surgery (T3), 60min after start of surgery (T4) and end of the surgery (T5). There were progressive decreases in both RrSO2 and LrSO2 levels in both groups, which were not statistically significant at T1, T2, T3, T4. The RrSO2 levels of Group L at T5 were significantly lower than that of Group O. One patient in Group L had an rSO2 value <80% of the baseline value. Carbon dioxide insufflation during pneumoperitoneum in pediatric patients may not affect cerebral oxygenation under laparoscopic surgery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  19. Effects of carbon dioxide insufflation on regional cerebral oxygenation during laparoscopic surgery in children: a prospective study.

    Science.gov (United States)

    Tuna, Ayca Tas; Akkoyun, Ibrahim; Darcin, Sevtap; Palabiyik, Onur

    2016-01-01

    Laparoscopic surgery has become a popular surgical tool when compared to traditional open surgery. There are limited data on pediatric patients regarding whether pneumoperitoneum affects cerebral oxygenation although end-tidal CO2 concentration remains normal. Therefore, this study was designed to evaluate the changes of cerebral oxygen saturation using near-infrared spectroscope during laparoscopic surgery in children. The study comprised forty children who were scheduled for laparoscopic (Group L, n=20) or open (Group O, n=20) appendectomy. Hemodynamic variables, right and left regional cerebral oxygen saturation (RrSO2 and LrSO2), fraction of inspired oxygen, end-tidal carbon dioxide pressure (PETCO2), peak inspiratory pressure (Ppeak), respiratory minute volume, inspiratory and end-tidal concentrations of sevoflurane and body temperature were recorded. All parameters were recorded after anesthesia induction and before start of surgery (T0, baseline), 15min after start of surgery (T1), 30min after start of surgery (T2), 45min after start of surgery (T3), 60min after start of surgery (T4) and end of the surgery (T5). There were progressive decreases in both RrSO2 and LrSO2 levels in both groups, which were not statistically significant at T1, T2, T3, T4. The RrSO2 levels of Group L at T5 were significantly lower than that of Group O. One patient in Group L had an rSO2 value <80% of the baseline value. Carbon dioxide insufflation during pneumoperitoneum in pediatric patients may not affect cerebral oxygenation under laparoscopic surgery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  20. The cerebral metabolic ratio is not affected by oxygen availability during maximal exercise in humans

    DEFF Research Database (Denmark)

    Volianitis, S.; Fabricius-Bjerre, A.; Overgaard, A.;

    2008-01-01

    .2% during exercise with an inspired O(2) fraction of 0.17 and 0.30, respectively. Whilst the increase in a-v lactate difference was attenuated by manipulation of cerebral O(2) availability, the cerebral metabolic ratio was not affected significantly. During maximal rowing, the cerebral metabolic ratio...

  1. Optically based quantification of absolute cerebral metabolic rate of oxygen (CMRO2) with high spatial resolution in rodents

    Science.gov (United States)

    Yaseen, Mohammad A.; Srinivasan, Vivek J.; Sakadžić, Sava; Vinogradov, Sergei A.; Boas, David A.

    2010-02-01

    Measuring oxygen delivery in brain tissue is important for identifying the pathophysiological changes associated with brain injury and various diseases such as cancer, stroke, and Alzheimer's disease. We have developed a multi-modal imaging system for minimally invasive measurement of cerebral oxygenation and blood flow in small animals with high spatial resolution. The system allows for simultaneous measurement of blood flow using Fourier-domain optical coherence tomography, and oxygen partial pressure (pO2) using either confocal or multiphoton phosphorescence lifetime imaging with exogenous porphyrin-based dyes sensitive to dissolved oxygen. Here we present the changes in pO2 and blood flow in superficial cortical vessels of Sprague Dawley rats in response to conditions such as hypoxia, hyperoxia, and functional stimulation. pO2 measurements display considerable heterogeneity over distances that cannot be resolved with more widely used oxygen-monitoring techniques such as BOLD-fMRI. Large increases in blood flow are observed in response to functional stimulation and hypoxia. Our system allows for quantification of cerebral metabolic rate of oxygen (CMRO2) with high spatial resolution, providing a better understanding of metabolic dynamics during functional stimulation and under various neuropathologies. Ultimately, better insight into the underlying mechanisms of neuropathologies will facilitate the development of improved therapeutic strategies to minimize damage to brain tissue.

  2. Effects of race and sex on cerebral hemodynamics, oxygen delivery and blood flow distribution in response to high altitude

    Science.gov (United States)

    Liu, Jie; Liu, Yang; Ren, Li-Hua; Li, Li; Wang, Zhen; Liu, Shan-Shan; Li, Su-Zhi; Cao, Tie-Sheng

    2016-08-01

    To assess racial, sexual, and regional differences in cerebral hemodynamic response to high altitude (HA, 3658 m). We performed cross-sectional comparisons on total cerebral blood flow (TCBF = sum of bilateral internal carotid and vertebral arterial blood flows = QICA + QVA), total cerebrovascular resistance (TCVR), total cerebral oxygen delivery (TCOD) and QVA/TCBF (%), among six groups of young healthy subjects: Tibetans (2-year staying) and Han (Han Chinese) at sea level, Han (2-day, 1-year and 5-year) and Tibetans at HA. Bilateral ICA and VA diameters and flow velocities were derived from duplex ultrasonography; and simultaneous measurements of arterial pressure, oxygen saturation, and hemoglobin concentration were conducted. Neither acute (2-day) nor chronic (>1 year) responses showed sex differences in Han, except that women showed lower TCOD compared with men. Tibetans and Han exhibited different chronic responses (percentage alteration relative to the sea-level counterpart value) in TCBF (‑17% vs. 0%), TCVR (22% vs. 12%), TCOD (0% vs. 10%) and QVA/TCBF (0% vs. 2.4%, absolute increase), with lower resting TCOD found in SL- and HA-Tibetans. Our findings indicate racial but not sex differences in cerebral hemodynamic adaptations to HA, with Tibetans (but not Han) demonstrating an altitude-related change of CBF distribution.

  3. Reduced cerebral blood flow and oxygen metabolism in extremely preterm neonates with low-grade germinal matrix- intraventricular hemorrhage

    Science.gov (United States)

    Lin, Pei-Yi; Hagan, Katherine; Fenoglio, Angela; Grant, P. Ellen; Franceschini, Maria Angela

    2016-05-01

    Low-grade germinal matrix-intraventricular hemorrhage (GM-IVH) is the most common complication in extremely premature neonates. The occurrence of GM-IVH is highly associated with hemodynamic instability in the premature brain, yet the long-term impact of low-grade GM-IVH on cerebral blood flow and neuronal health have not been fully investigated. We used an innovative combination of frequency-domain near infrared spectroscopy and diffuse correlation spectroscopy (FDNIRS-DCS) to measure cerebral oxygen saturation (SO2) and an index of cerebral blood flow (CBFi) at the infant’s bedside and compute an index of cerebral oxygen metabolism (CMRO2i). We enrolled twenty extremely low gestational age (ELGA) neonates (seven with low-grade GM-IVH) and monitored them weekly until they reached full-term equivalent age. During their hospital stay, we observed consistently lower CBFi and CMRO2i in ELGA neonates with low-grade GM-IVH compared to neonates without hemorrhages. Furthermore, lower CBFi and CMRO2i in the former group persists even after the resolution of the hemorrhage. In contrast, SO2 does not differ between groups. Thus, CBFi and CMRO2i may have better sensitivity than SO2 in detecting GM-IVH-related effects on infant brain development. FDNIRS-DCS methods may have clinical benefit for monitoring the evolution of GM-IVH, evaluating treatment response, and potentially predicting neurodevelopmental outcome.

  4. Quantitative measurement of cerebral oxygen extraction fraction using MRI in patients with MELAS.

    Directory of Open Access Journals (Sweden)

    Lei Yu

    Full Text Available OBJECTIVE: To quantify the cerebral OEF at different phases of stroke-like episodes in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS by using MRI. METHODS: We recruited 32 patients with MELAS confirmed by gene analysis. Conventional MRI scanning, as well as functional MRI including arterial spin labeling and oxygen extraction fraction imaging, was undertaken to obtain the pathological and metabolic information of the brains at different stages of stroke-like episodes in patients. A total of 16 MRI examinations at the acute and subacute phase and 19 examinations at the interictal phase were performed. In addition, 24 healthy volunteers were recruited for control subjects. Six regions of interest were placed in the anterior, middle, and posterior parts of the bilateral hemispheres to measure the OEF of the brain or the lesions. RESULTS: OEF was reduced significantly in brains of patients at both the acute and subacute phase (0.266 ± 0.026 and at the interictal phase (0.295 ± 0.009, compared with normal controls (0.316 ± 0.025. In the brains at the acute and subacute phase of the episode, 13 ROIs were prescribed on the stroke-like lesions, which showed decreased OEF compared with the contralateral spared brain regions. Increased blood flow was revealed in the stroke-like lesions at the acute and subacute phase, which was confined to the lesions. CONCLUSION: MRI can quantitatively show changes in OEF at different phases of stroke-like episodes. The utilization of oxygen in the brain seems to be reduced more severely after the onset of episodes in MELAS, especially for those brain tissues involved in the episodes.

  5. Brazilein inhibits neuronal inflammation induced by cerebral ischemia and oxygen-glucose deprivation through targeting NOD2 expression.

    Science.gov (United States)

    Yan, Xiao-Jin; Chai, Yu-Shuang; Yuan, Zhi-Yi; Wang, Xin-Pei; Jiang, Jing-Fei; Lei, Fan; Xing, Dong-Ming; DU, Li-Jun

    2016-05-01

    Brazilein is reported to have immunosuppressive effect on cardiovascular and cerebral-vascular diseases. The essential roles of innate immunity in cerebral ischemia are increasingly identified, but no studies concerning the influence of brazilein on the innate immunity receptors have been reported. The present study was designed to investigate the regulation of NOD2 (Nucleotide-binding oligomerization domain-containing protein 2) by brazilein for its protection of neuron in cerebral ischemia in vivo and oxygen-glucose deprivation in vitro. The results showed that brazilein could reverse the elevated expression of NOD2 and TNFα (tumor necrosis factor alpha) elicited by cerebral ischemia and reperfusion. This reduction could also be detected in normal mice and C17.2 cells, indicating that this suppressive effect of brazilein was correlated with NOD2. The results from GFP reporter plasmid assay suggested brazilein inhibited NOD2 gene transcription. In conclusion, brazilein could attenuate NOD2 and TNFα expression in cerebral ischemia and NOD2 may be one possible target of brazilein for its immune suppressive effect in neuro-inflammation.

  6. Retrospective Analysis of Transcranial Doppler Patterns in Veno-Arterial Extracorporeal Membrane Oxygenation Patients: Feasibility of Cerebral Circulatory Arrest Diagnosis.

    Science.gov (United States)

    Marinoni, Marinella; Cianchi, Giovanni; Trapani, Sara; Migliaccio, Maria L; Bonizzoli, Manuela; Gucci, Letizia; Cramaro, Antonella; Gallerini, Andrea; Picciafuochi, Fabio; Valente, Serafina; Peris, Adriano

    2017-08-01

    Transcranial Doppler (TCD) is able to detect cerebral hemodynamic changes in real-time. Impairment of cerebral blood flow during veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) treatment is referred to in the literature. Several cerebrovascular complications can affect VA ECMO patients, eventually leading to brain death (BD). Transcranial Doppler is a worldwide accepted technique for cerebral circulatory arrest (CCA) diagnosis for BD confirmation, and in Italy, it is mandatory in certain clinical conditions. Nowadays, no data have been published on the use of TCD as a confirmation test in VA ECMO patients evolved to BD. The aim of our study was to investigate the feasibility of TCD in CCA diagnosis during VA ECMO treatment. Thirty-two TCD examinations, performed in 25 patients on VA ECMO, were retrospectively analyzed, and factors that could be responsible for TCD waveforms abnormalities were reviewed. Differences in TCD patterns were detected depending on values of left ventricular ejection fraction and the absence or presence of intraaortic balloon pump (IABP). Four categories of different TCD patterns were then identified. In five BD patients, diagnostic CCA patterns in all cerebral arteries were identified by TCD. Our data suggest that cerebral hemodynamic changes due to both residual cardiac function and the effects of IABP can be detected by transcranial Doppler (TCD) in VA ECMO patients. In the case of BD, TCD seems to be a reliable instrumental test for CCA diagnosis in patients on VA ECMO when a pulsatile flow is maintained (native or IABP support).

  7. Effect of head rotation during surgery in the prone position on regional cerebral oxygen saturation

    DEFF Research Database (Denmark)

    Andersen, Johnny Dohn Holmgren; Baake, Gerben; Wiis, Julie Therese;

    2014-01-01

    BACKGROUND: Near-infrared spectroscopy (NIRS) has been used to study regional cerebral blood oxygen saturation (rScO2) in patients in the prone position. OBJECTIVES: We aimed to test the hypothesis that head rotation more than 45° would affect the rScO2. DESIGN: A prospective, controlled, single......-state anaesthesia with the head in the neutral position, rotated left, rotated right and returned to the neutral position. Each series consisted of three measurements: resting on the head support, during head lift (to relieve pressure on the tissue at the sensors) and returned to rest on the head support. MAIN...... OUTCOME MEASURES: The differences in rScO2 between the neutral and the turned head positions. RESULTS: For both left and right sensors, the median differences in rScO2 between neutral and left or right positions were between 0 and -1 with the head up (P = 0.14 to 0.84). The median differences...

  8. Wavelet analysis of cerebral oxygenation oscillations in the screening of Moyamoya disease.

    Science.gov (United States)

    He, Ying; Jiang, Pengjun; Han, Shanshan; Wang, Rong; Li, Yue; Teng, Yichao; Gao, Tianxin

    2014-01-01

    Near-infrared spectroscopy (NIRS) was used to investigate the cerebral oxygenation of Moyamoya and healthy subjects. Continuous recordings of NIRS signals for 20 min (20 min signals) were obtained from 17 healthy subjects (age: 37.4 ± 11.3) and 17 Moyamoya subjects (age: 40.1 ± 11.2). Spectral analysis based on wavelet transformation identified five frequency intervals (I, 0.0095 Hz to 0.02 Hz; II, 0.02 Hz to 0.06 Hz; III, 0.06 Hz to 0.15 Hz; IV, 0.15 Hz to 0.40 Hz; and V, 0.40 Hz to 2.00 Hz) in the 20 min signals and three frequency intervals (III, 0.06 Hz to 0.15 Hz; IV, 0.15 Hz to 0.40 Hz; and V, 0.40 Hz to 2.00 Hz) in the 3 min signals (the first 3 min signals were continuously extracted from the 20 min signals). Significant differences (p Moyamoya disease. As a potential screening method for Moyamoya disease, the simple threshold method exhibited 73.5% accuracy.

  9. Neurotrophin-3 promotes cell death induced in cerebral ischemia, oxygen-glucose deprivation, and oxidative stress: possible involvement of oxygen free radicals.

    Science.gov (United States)

    Bates, Brian; Hirt, Lorenz; Thomas, Sunu S; Akbarian, Schahram; Le, Dean; Amin-Hanjani, Sepideh; Whalen, Michael; Jaenisch, Rudolf; Moskowitz, Michael A

    2002-02-01

    To explore the role of neurotrophin-3 (NT-3) during cerebral ischemia, NT-3-deficient brains were subjected to transient focal ischemia. Conditional mutant brains produced undetectable amounts of NT-3 mRNA, whereas the expression of the neurotrophin, BDNF, the NT-3 receptor, TrkC, and the nonselective, low-affinity neurotrophin receptor p75NTR, were comparable to wild-type. Baseline absolute blood flow, vascular and neuroanatomical features, as well as physiological measurements were also indistinguishable from wild-type. Interestingly, the absence of NT-3 led to a significantly decreased infarct volume 23 h after middle cerebral artery occlusion. Consistent with this, the addition of NT-3 to primary cortical cell cultures exacerbated neuronal death caused by oxygen-glucose deprivation. Coincubation with the oxygen free radical chelator, trolox, diminished potentiation of neuronal death. NT-3 also enhanced neuronal cell death and the production of reactive oxygen species caused by oxidative damage inducing agents. We conclude that endogenous NT-3 enhanced neuronal injury during acute stroke, possible by increasing oxygen-radical mediated cell death.

  10. 高压氧治疗脑梗死疗效观察%Observation of therapeutic effect of hyperbaric oxygen on cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    马维艳; 杨丽

    2002-01-01

    Background:Hypoxia and ischemia resulting from cerebral infarction can further cause a series of pathological changes such as hydrocephallus.Drug therapy can improve cerebral blood circulation and enhance flow volume and decrease infarction area.If hyperbaric oxygen is added,pathophysiological changes such as ischemia and hypoxia can be improved and normal metabolism of brain cells be restored.

  11. Quantifying the cerebral metabolic rate of oxygen by combining diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy.

    Science.gov (United States)

    Verdecchia, Kyle; Diop, Mamadou; Lee, Ting-Yim; St Lawrence, Keith

    2013-02-01

    Preterm infants are highly susceptible to ischemic brain injury; consequently, continuous bedside monitoring to detect ischemia before irreversible damage occurs would improve patient outcome. In addition to monitoring cerebral blood flow (CBF), assessing the cerebral metabolic rate of oxygen (CMRO2) would be beneficial considering that metabolic thresholds can be used to evaluate tissue viability. The purpose of this study was to demonstrate that changes in absolute CMRO2 could be measured by combining diffuse correlation spectroscopy (DCS) with time-resolved near-infrared spectroscopy (TR-NIRS). Absolute CBF was determined using bolus-tracking TR-NIRS to calibrate the DCS measurements. Cerebral venous blood oxygenation (SvO2) was determined by multiwavelength TR-NIRS measurements, the accuracy of which was assessed by directly measuring the oxygenation of sagittal sinus blood. In eight newborn piglets, CMRO2 was manipulated by varying the anesthetics and by injecting sodium cyanide. No significant differences were found between the two sets of SvO2 measurements obtained by TR-NIRS or sagittal sinus blood samples and the corresponding CMRO2 measurements. Bland-Altman analysis showed a mean CMRO2 difference of 0.0268 ± 0.8340 mLO2/100 g/min between the two techniques over a range from 0.3 to 4 mL O2/100 g/min.

  12. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor.

    Science.gov (United States)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha

    2014-03-25

    The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion(®). The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion(®), resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  13. Stackable Miniature Fuel Cells with On-Demand Fuel and Oxygen Supply

    OpenAIRE

    Hur, Janet

    2013-01-01

    This dissertation summarizes our progress towards miniature fuel cells that could replace and outperform small batteries to meet various power demands. With increasing need of power being critical for portable electronics, the demand for better batteries continues to grow. Lithium-ion batteries dominate the market at the moment, but the current capacities on the order of 200 Wh/kg are approaching their inherent limits. Many researchers have being pursuing alternative power sources, forming a ...

  14. A New Approach for On-Demand Generation of Various Oxygen Tensions for In Vitro Hypoxia Models.

    Directory of Open Access Journals (Sweden)

    Chunyan Li

    Full Text Available The development of in vitro disease models closely mimicking the functions of human disease has captured increasing attention in recent years. Oxygen tensions and gradients play essential roles in modulating biological systems in both physiologic and pathologic events. Thus, controlling oxygen tension is critical for mimicking physiologically relevant in vivo environments for cell, tissue and organ research. We present a new approach for on-demand generation of various oxygen tensions for in vitro hypoxia models. Proof-of-concept prototypes have been developed for conventional cell culture microplate by immobilizing a novel oxygen-consuming biomaterial on the 3D-printed insert. For the first time, rapid (~3.8 minutes to reach 0.5% O2 from 20.9% O2 and precisely controlled oxygen tensions/gradients (2.68 mmHg per 50 μm distance were generated by exposing the biocompatible biomaterial to the different depth of cell culture media. In addition, changing the position of 3D-printed inserts with immobilized biomaterials relative to the cultured cells resulted in controllable and rapid changes in oxygen tensions (<130 seconds. Compared to the current technologies, our approach allows enhanced spatiotemporal resolution and accuracy of the oxygen tensions. Additionally, it does not interfere with the testing environment while maintaining ease of use. The elegance of oxygen tension manipulation introduced by our new approach will drastically improve control and lower the technological barrier of entry for hypoxia studies. Since the biomaterials can be immobilized in any devices, including microfluidic devices and 3D-printed tissues or organs, it will serve as the basis for a new generation of experimental models previously impossible or very difficult to implement.

  15. Characterization of water quality and simulation of temperature, nutrients, biochemical oxygen demand, and dissolved oxygen in the Wateree River, South Carolina, 1996-98

    Science.gov (United States)

    Feaster, Toby D.; Conrads, Paul A.

    2000-01-01

    In May 1996, the U.S. Geological Survey entered into a cooperative agreement with the Kershaw County Water and Sewer Authority to characterize and simulate the water quality in the Wateree River, South Carolina. Longitudinal profiling of dissolved-oxygen concentrations during the spring and summer of 1996 revealed dissolved-oxygen minimums occurring upstream from the point-source discharges. The mean dissolved-oxygen decrease upstream from the effluent discharges was 2.0 milligrams per liter, and the decrease downstream from the effluent discharges was 0.2 milligram per liter. Several theories were investigated to obtain an improved understanding of the dissolved-oxygen dynamics in the upper Wateree River. Data suggest that the dissolved-oxygen concentration decrease is associated with elevated levels of oxygen-consuming nutrients and metals that are flowing into the Wateree River from Lake Wateree. Analysis of long-term streamflow and water-quality data collected at two U.S. Geological Survey gaging stations suggests that no strong correlation exists between streamflow and dissolved-oxygen concentrations in the Wateree River. However, a strong negative correlation does exist between dissolved-oxygen concentrations and water temperature. Analysis of data from six South Carolina Department of Health and Environmental Control monitoring stations for 1980.95 revealed decreasing trends in ammonia nitrogen at all stations where data were available and decreasing trends in 5-day biochemical oxygen demand at three river stations. The influence of various hydrologic and point-source loading conditions on dissolved-oxygen concentrations in the Wateree River were determined by using results from water-quality simulations by the Branched Lagrangian Transport Model. The effects of five tributaries and four point-source discharges were included in the model. Data collected during two synoptic water-quality samplings on June 23.25 and August 11.13, 1997, were used to calibrate

  16. Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

    Science.gov (United States)

    Boas, D. A.; Strangman, G.; Culver, J. P.; Hoge, R. D.; Jasdzewski, G.; Poldrack, R. A.; Rosen, B. R.; Mandeville, J. B.

    2003-08-01

    We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO2) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on a Windkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO2 change. An absolute estimate is also confounded by uncertainty in the flow-volume relationship. However, the ratio of the flow change to the CMRO2 change is relatively insensitive to these uncertainties. For the finger tapping task, we estimate a most probable flow-consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow-consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI.

  17. Blood flow and oxygenation changes due to low-frequency repetitive transcranial magnetic stimulation of the cerebral cortex

    Science.gov (United States)

    Mesquita, Rickson C.; Faseyitan, Olufunsho K.; Turkeltaub, Peter E.; Buckley, Erin M.; Thomas, Amy; Kim, Meeri N.; Durduran, Turgut; Greenberg, Joel H.; Detre, John A.; Yodh, Arjun G.; Hamilton, Roy H.

    2013-06-01

    Transcranial magnetic stimulation (TMS) modulates processing in the human brain and is therefore of interest as a treatment modality for neurologic conditions. During TMS administration, an electric current passing through a coil on the scalp creates a rapidly varying magnetic field that induces currents in the cerebral cortex. The effects of low-frequency (1 Hz), repetitive TMS (rTMS) on motor cortex cerebral blood flow (CBF) and tissue oxygenation in seven healthy adults, during/after 20 min stimulation, is reported. Noninvasive optical methods are employed: diffuse correlation spectroscopy (DCS) for blood flow and diffuse optical spectroscopy (DOS) for hemoglobin concentrations. A significant increase in median CBF (33%) on the side ipsilateral to stimulation was observed during rTMS and persisted after discontinuation. The measured hemodynamic parameter variations enabled computation of relative changes in cerebral metabolic rate of oxygen consumption during rTMS, which increased significantly (28%) in the stimulated hemisphere. By contrast, hemodynamic changes from baseline were not observed contralateral to rTMS administration (all parameters, p>0.29). In total, these findings provide new information about hemodynamic/metabolic responses to low-frequency rTMS and, importantly, demonstrate the feasibility of DCS/DOS for noninvasive monitoring of TMS-induced physiologic effects.

  18. Influence of biological oxygen demand degradation patterns on water-quality modeling for rivers running through urban areas.

    Science.gov (United States)

    Fan, Chihhao; Wang, Wei-Shen

    2008-10-01

    Water-quality modeling has been used as a support tool for water-resources management. The Streeter-Phelps (SP) equation is one often-used algorithm in river water-quality simulation because of its simplicity and ease in use. To characterize the river dissolved oxygen (DO) sag profile, it only considers that the first-order biological oxygen demand (BOD) degradation and atmospheric reaeration are the sink and source in a river, respectively. In the river water-quality calculation, the assumption may not always provide satisfactory simulation due to an inappropriate description of BOD degradation. In the study, various patterns of BOD degradation were combined with the oxygen reaeration to simulate the DO sag profile in a river. Different BOD degradation patterns used include the first-order decay, mixed second-order decay, and oxygen-inhibition decay. The results shows that the oxygen-inhibition SP equation calculates higher BOD and DO concentration, while the mixed second SP equation calculates the least among the three tested models. In river-water calculation of Keelung River, the SP and oxygen-inhibition SP equations calculate similar BOD and DO concentrations, and the mixed second SP equation calculates the least BOD and DO concentration. The pollution loading of BOD and atmospheric reaeration constant are the two important factors that have significant impacts on aqueous DO concentration. In the field application, it is suggested that the mixed second SP equation be employed in water-quality simulation when the monitoring data exhibits a faster trend in BOD decay. The oxygen-inhibition SP equation may calculate the water quality more accurately when BOD decay is slower.

  19. Simulated impacts of ankle foot orthoses on muscle demand and recruitment in typically-developing children and children with cerebral palsy and crouch gait.

    Science.gov (United States)

    Rosenberg, Michael; Steele, Katherine M

    2017-01-01

    Passive ankle foot orthoses (AFOs) are often prescribed for children with cerebral palsy (CP) to assist locomotion, but predicting how specific device designs will impact energetic demand during gait remains challenging. Powered AFOs have been shown to reduce energy costs of walking in unimpaired adults more than passive AFOs, but have not been tested in children with CP. The goal of this study was to investigate the potential impact of powered and passive AFOs on muscle demand and recruitment in children with CP and crouch gait. We simulated gait for nine children with crouch gait and three typically-developing children with powered and passive AFOs. For each AFO design, we computed reductions in muscle demand compared to unassisted gait. Powered AFOs reduced muscle demand 15-44% compared to unassisted walking, 1-14% more than passive AFOs. A slower walking speed was associated with smaller reductions in absolute muscle demand for all AFOs (r2 = 0.60-0.70). However, reductions in muscle demand were only moderately correlated with crouch severity (r2 = 0.40-0.43). The ankle plantarflexor muscles were most heavily impacted by the AFOs, with gastrocnemius recruitment decreasing 13-73% and correlating with increasing knee flexor moments (r2 = 0.29-0.91). These findings support the potential use of powered AFOs for children with crouch gait, and highlight how subject-specific kinematics and kinetics may influence muscle demand and recruitment to inform AFO design.

  20. Control of voluntary feed intake in fish: a role for dietary oxygen demand in Nile tilapia (Oreochromis niloticus) fed diets with different macronutrient profiles.

    Science.gov (United States)

    Saravanan, S; Geurden, I; Figueiredo-Silva, A C; Kaushik, S J; Haidar, M N; Verreth, J A J; Schrama, J W

    2012-10-28

    It has been hypothesised that, at non-limiting water oxygen conditions, voluntary feed intake (FI) in fish is limited by the maximal physiological capacity of oxygen use (i.e. an 'oxystatic control of FI in fish'). This implies that fish will adjust FI when fed diets differing in oxygen demand, resulting in identical oxygen consumption. Therefore, FI, digestible energy (DE) intake, energy balance and oxygen consumption were monitored at non-limiting water oxygen conditions in Nile tilapia fed diets with contrasting macronutrient composition. Diets were formulated in a 2 × 2 factorial design in order to create contrasts in oxygen demand: two ratios of digestible protein (DP):DE ('high' v. 'low'); and a contrast in the type of non-protein energy source ('starch' v. 'fat'). Triplicate groups of tilapia were fed each diet twice daily to satiation for 48 d. FI (g DM/kg(0·8) per d) was significantly lower (9·5%) in tilapia fed the starch diets relative to the fat diets. The DP:DE ratio affected DE intakes (P demand of these diets. Indeed, DE intakes of fish showed an inverse linear relationship with dietary oxygen demand (DOD; R 2 0·81, P theory), oxygen consumption of fish was identical among three out of the four diets. Altogether, these results demonstrate the involvement of metabolic oxygen use and DOD in the control of FI in tilapia.

  1. Comparison of cerebral oxygen saturation in premature infants by near-infrared spatially resolved spectroscopy: observations on probe-dependent bias

    DEFF Research Database (Denmark)

    Sorensen, Line C; Leung, Terence S; Greisen, Gorm

    2008-01-01

    Spatially resolved spectroscopy (SRS) allows the estimation of absolute tissue oxygen saturation, the ratio of oxygenated to total hemoglobin concentration, which may facilitate the comparison of results among patients. Eighty-two premature infants were included over two years. The cerebral tissue...

  2. The SafeBoosC Phase II Randomised Clinical Trial : A Treatment Guideline for Targeted Near-Infrared-Derived Cerebral Tissue Oxygenation versus Standard Treatment in Extremely Preterm Infants

    NARCIS (Netherlands)

    Pellicer, Adelina; Greisen, Gorm; Benders, Manon; Claris, Olivier; Dempsey, Eugene; Fumagalli, Monica; Gluud, Christian; Hagmann, Cornelia; Hellstroem-Westas, Lena; Hyttel-Sorensen, Simon; Lemmers, Petra; Naulaers, Gunnar; Pichler, Gerhard; Roll, Claudia; van Bel, Frank; van Oeveren, Wim; Skoog, Maria; Wolf, Martin; Austin, Topun

    2013-01-01

    Near-infrared spectroscopy-derived regional tissue oxygen saturation of haemoglobin (rSto(2)) reflects venous oxygen saturation. If cerebral metabolism is stable, rSto(2) can be used as an estimate of cerebral oxygen delivery. The SafeBoosC phase II randomised clinical trial hypothesises that the bu

  3. The SafeBoosC Phase II Randomised Clinical Trial : A Treatment Guideline for Targeted Near-Infrared-Derived Cerebral Tissue Oxygenation versus Standard Treatment in Extremely Preterm Infants

    NARCIS (Netherlands)

    Pellicer, Adelina; Greisen, Gorm; Benders, Manon; Claris, Olivier; Dempsey, Eugene; Fumagalli, Monica; Gluud, Christian; Hagmann, Cornelia; Hellstroem-Westas, Lena; Hyttel-Sorensen, Simon; Lemmers, Petra; Naulaers, Gunnar; Pichler, Gerhard; Roll, Claudia; van Bel, Frank; van Oeveren, Wim; Skoog, Maria; Wolf, Martin; Austin, Topun

    2013-01-01

    Near-infrared spectroscopy-derived regional tissue oxygen saturation of haemoglobin (rSto(2)) reflects venous oxygen saturation. If cerebral metabolism is stable, rSto(2) can be used as an estimate of cerebral oxygen delivery. The SafeBoosC phase II randomised clinical trial hypothesises that the bu

  4. Reduced Cerebral Oxygen Content in the DG and SVZ In Situ Promotes Neurogenesis in the Adult Rat Brain In Vivo.

    Directory of Open Access Journals (Sweden)

    Kuan Zhang

    Full Text Available Neurogenesis in the adult brain occurs mainly within two neurogenic structures, the dentate gyrus (DG of the hippocampus and the sub-ventricular zone (SVZ of the forebrain. It has been reported that mild hypoxia promoted the proliferation of Neural Stem Cells (NSCsin vitro. Our previous study further demonstrated that an external hypoxic environment stimulated neurogenesis in the adult rat brain in vivo. However, it remains unknown how external hypoxic environments affect the oxygen content in the brain and result in neurogenesis. Here we use an optical fiber luminescent oxygen sensor to detect the oxygen content in the adult rat brain in situ under normoxia and hypoxia. We found that the distribution of oxygen in cerebral regions is spatiotemporally heterogeneous. The Po2 values in the ventricles (45∼50 Torr and DG (approximately 10 Torr were much higher than those of other parts of the brain, such as the cortex and thalamus (approximately 2 Torr. Interestingly, our in vivo studies showed that an external hypoxic environment could change the intrinsic oxygen content in brain tissues, notably reducing oxygen levels in both the DG and SVZ, the major sites of adult neurogenesis. Furthermore, the hypoxic environment also increased the expression of HIF-1α and VEGF, two factors that have been reported to regulate neurogenesis, within the DG and SVZ. Thus, we have demonstrated that reducing the oxygen content of the external environment decreased Po2 levels in the DG and SVZ. This reduced oxygen level in the DG and SVZ might be the main mechanism triggering neurogenesis in the adult brain. More importantly, we speculate that varying oxygen levels may be the physiological basis of the regionally restricted neurogenesis in the adult brain.

  5. Reduced Cerebral Oxygen Content in the DG and SVZ In Situ Promotes Neurogenesis in the Adult Rat Brain In Vivo.

    Science.gov (United States)

    Zhang, Kuan; Zhou, Yanzhao; Zhao, Tong; Wu, Liying; Huang, Xin; Wu, Kuiwu; Xu, Lun; Li, Dahu; Liu, Shuhong; Zhao, Yongqi; Fan, Ming; Zhu, Lingling

    2015-01-01

    Neurogenesis in the adult brain occurs mainly within two neurogenic structures, the dentate gyrus (DG) of the hippocampus and the sub-ventricular zone (SVZ) of the forebrain. It has been reported that mild hypoxia promoted the proliferation of Neural Stem Cells (NSCs)in vitro. Our previous study further demonstrated that an external hypoxic environment stimulated neurogenesis in the adult rat brain in vivo. However, it remains unknown how external hypoxic environments affect the oxygen content in the brain and result in neurogenesis. Here we use an optical fiber luminescent oxygen sensor to detect the oxygen content in the adult rat brain in situ under normoxia and hypoxia. We found that the distribution of oxygen in cerebral regions is spatiotemporally heterogeneous. The Po2 values in the ventricles (45∼50 Torr) and DG (approximately 10 Torr) were much higher than those of other parts of the brain, such as the cortex and thalamus (approximately 2 Torr). Interestingly, our in vivo studies showed that an external hypoxic environment could change the intrinsic oxygen content in brain tissues, notably reducing oxygen levels in both the DG and SVZ, the major sites of adult neurogenesis. Furthermore, the hypoxic environment also increased the expression of HIF-1α and VEGF, two factors that have been reported to regulate neurogenesis, within the DG and SVZ. Thus, we have demonstrated that reducing the oxygen content of the external environment decreased Po2 levels in the DG and SVZ. This reduced oxygen level in the DG and SVZ might be the main mechanism triggering neurogenesis in the adult brain. More importantly, we speculate that varying oxygen levels may be the physiological basis of the regionally restricted neurogenesis in the adult brain.

  6. The effect of sand-bed filtration on the oxygen demand ...

    African Journals Online (AJOL)

    SERVER

    2007-09-19

    Sep 19, 2007 ... microbial population present in the system at that time. (Tchobanoglous, 1979 ... dissolved oxygen concentration of 5 – 7 mg/l (Henry and. Heinke, 1989). A well balance warm water where fish can thrive for example requires a ...

  7. Seasonal contribution of terrestrial organic matter and biological oxygen demand to the Baltic Sea from three contrasting river catchments

    DEFF Research Database (Denmark)

    Reader, H. E.; Stedmon, C. A.; Kritzberg, E. S.

    2014-01-01

    To examine the potential influence of terrestrially derived DOM on the Baltic Sea, a year-long study of dissolved organic matter (DOM) was performed in three river catchments in Sweden. One catchment drains into the Bothnian Sea, while two southern catchments drain into the Baltic proper. Dissolved...... on the same order of magnitude for all three catchments. Biological oxygen demand (BOD) was used as a proxy for the lability of carbon in the system. The range of BOD values was similar for all three catchments, however, the ratio of BOD to DOC (an indication of the labile fraction) in Ume river was four...

  8. The Effect of Equal Ratio Ventilation on Oxygenation, Respiratory Mechanics, and Cerebral Perfusion Pressure During Laparoscopy in the Trendelenburg Position.

    Science.gov (United States)

    Jo, Youn Yi; Kim, Ji Young; Chang, Young Jin; Lee, Sehwan; Kwak, Hyun Jeong

    2016-06-01

    The aim of this study was to investigate the effects of equal ratio ventilation (ERV) on oxygenation, respiratory mechanics, and the cerebral perfusion pressure during pneumoperitoneum in the Trendelenburg position. Thirty patients undergoing laparoscopic low anterior resection (25 to 65 y) were enrolled. Mechanical ventilator was set to volume-controlled mode at an inspiratory to expiratory (I:E) ratio of 1:2 with a tidal volume of 8 mL/kg of ideal body weight with a 5 cm H2O positive end-expiratory pressure. Twenty minutes after pneumoperitoneum in the Trendelenburg position, the I:E ratio was changed to 1:1 for 20 minutes and then restored to 1:2. No significant changes in arterial oxygen tension and respiratory compliance after adopting ERV. Mean arterial pressure and cerebral perfusion pressure decreased significantly over time after adopting the Trendelenburg position during pneumoperitoneum (P=0.014 and 0.005, respectively). In conclusion, there was no improvement in oxygenation or respiratory mechanics with ERV.

  9. Coupling of cerebral blood flow and oxygen metabolism is conserved for chromatic and luminance stimuli in human visual cortex.

    Science.gov (United States)

    Leontiev, Oleg; Buracas, Giedrius T; Liang, Christine; Ances, Beau M; Perthen, Joanna E; Shmuel, Amir; Buxton, Richard B

    2013-03-01

    The ratio of the changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO(2)) during brain activation is a critical determinant of the magnitude of the blood oxygenation level dependent (BOLD) response measured with functional magnetic resonance imaging (fMRI). Cytochrome oxidase (CO), a key component of oxidative metabolism in the mitochondria, is non-uniformly distributed in visual area V1 in distinct blob and interblob regions, suggesting significant spatial variation in the capacity for oxygen metabolism. The goal of this study was to test whether CBF/CMRO(2) coupling differed when these subpopulations of neurons were preferentially stimulated, using chromatic and luminance stimuli to preferentially stimulate either the blob or interblob regions. A dual-echo spiral arterial spin labeling (ASL) technique was used to measure CBF and BOLD responses simultaneously in 7 healthy human subjects. When the stimulus contrast levels were adjusted to evoke similar CBF responses (mean 65.4% ± 19.0% and 64.6% ± 19.9%, respectively for chromatic and luminance contrast), the BOLD responses were remarkably similar (1.57% ± 0.39% and 1.59% ± 0.35%) for both types of stimuli. We conclude that CBF-CMRO(2) coupling is conserved for the chromatic and luminance stimuli used, suggesting a consistent coupling for blob and inter-blob neuronal populations despite the difference in CO concentration.

  10. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha, E-mail: sangeetha@annauniv.edu

    2014-03-01

    Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion{sup ®}. • SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}. • Nafion{sup ®} shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion{sup ®}. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  11. Discriminating between west-side sources of nutrients and organiccarbon contributing to algal growth and oxygen demand in the San JoaquinRiver

    Energy Technology Data Exchange (ETDEWEB)

    Wstringfellow@lbl.gov

    2002-07-24

    The purpose of this study was to investigate the Salt and Mud Slough tributaries as sources of oxygen demanding materials entering the San Joaquin River (SJR). Mud Slough and Salt Slough are the main drainage arteries of the Grasslands Watershed, a 370,000-acre area west of the SJR, covering portions of Merced and Fresno Counties. Although these tributaries of the SJR are typically classified as agricultural, they are also heavily influenced by Federal, State and private wetlands. The majority of the surface water used for both irrigation and wetland management in the Grassland Watershed is imported from the Sacramento-San Joaquin Delta through the Delta-Mendota Canal. In this study, they measured algal biomass (as chlorophyll a), organic carbon, ammonia, biochemical oxygen demand (BOD), and other measures of water quality in drainage from both agricultural and wetland sources at key points in the Salt Slough and Mud Slough tributaries. This report includes the data collected between June 16th and October 4th, 2001. The objective of the study was to compare agricultural and wetland drainage in the Grasslands Watershed and to determine the relative importance of each return flow source to the concentration and mass loading of oxygen demanding materials entering the SJR. Additionally, they compared the quality of water exiting our study area to water entering our study area. This study has demonstrated that Salt and Mud Sloughs both contribute significant amounts of oxygen demand to the SJR. Together, these tributaries could account for 35% of the oxygen demand observed below their confluence with the SJR. This study has characterized the sources of oxygen demanding materials entering Mud Slough and evaluated the oxygen demand conditions in Salt Slough. Salt Slough was found to be the dominant source of oxygen demand load in the study area, because of the higher flows in this tributary. The origins of oxygen demand in Salt Slough still remain largely uninvestigated

  12. Cerebral oxygenation in patients undergoing shoulder surgery in beach chair position: comparing general to regional anesthesia and the impact on neurobehavioral outcome.

    Science.gov (United States)

    Aguirre, J; Borgeat, A; Trachsel, T; Cobo Del Prado, I; De Andrés, J; Bühler, P

    2014-02-01

    Ischemic brain damage has been reported in healthy patients after beach chair position for surgery due to cerebral hypoperfusion. Near-infrared spectroscopy has been described as a non-invasive, continuous method to monitor cerebral oxygen saturation. However, its impact on neurobehavioral outcome comparing different anesthesia regimens has been poorly described. In this prospective, assessor-blinded study, 90 patients undergoing shoulder surgery in beach chair position following general (G-group, n=45) or regional anesthesia (R-group; n=45) were enrolled to assess the prevalence of cerebral desaturation events comparing anesthesia regimens and their impact on neurobehavioral and neurological outcome. Anesthesiologists were blinded to regional cerebral oxygen saturation values. Baseline data assessed the day before surgery included neurological and neurobehavioral tests, which were repeated the day after surgery. The baseline data for regional cerebral oxygen saturation/bispectral index and invasive blood pressure both at heart and auditory meatus levels were taken prior to anesthesia, 5 min after induction of anesthesia, 5 min after beach chair positioning, after skin incision and thereafter all 20 min until discharge. Patients in the R-group showed significantly less cerebral desaturation events (p<0.001), drops in regional cerebral oxygen saturation values (p<0.001), significantly better neurobehavioral test results the day after surgery (p<0.001) and showed a greater hemodynamic stability in the beach chair position compared to patients in the G-group. The incidence of regional cerebral oxygen desaturations seems to influence the neurobehavioral outcome. Regional anesthesia offers more stable cardiovascular conditions for shoulder surgery in beach chair position influencing neurobehavioral test results at 24h. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  13. Cerebral tissue oxygenation index and superior vena cava blood flow in the very low birth weight infant.

    LENUS (Irish Health Repository)

    Moran, M

    2012-02-01

    BACKGROUND: Superior vena cava (SVC) flow assesses blood flow from the upper body, including the brain. Near infrared spectroscopy (NIRS) provides information on brain perfusion and oxygenation. AIM: To assess the relationship between cerebral tissue oxygenation index (cTOI) and cardiac output measures in the very low birth weight (VLBW) infant in the first day of life. METHODS: A prospective observational cohort study. Neonates with birth weight less than 1500 g (VLBW) were eligible for enrollment. Newborns with congenital heart disease, major congenital malformations and greater than Papile grade1 Intraventricular Haemorrhage on day 1 of life were excluded. Echocardiographic evaluation of SVC flow was performed in the first 24 h of life. Low SVC flow states were defined as a flow less than 40 mL\\/kg\\/min. cTOI was measured using NIRO 200 Hamamatsu. RESULTS: Twenty-seven VLBW neonates had both echocardiography and NIRS performed. The median (range) gestation was 29\\/40 (25 + 3 to 31 + 5 weeks) and median birth weight was 1.2 kg (0.57-1.48 kg). The mean (SD) TOI was 68.1 (7.9)%. The mean (SD) SVC flow was 70.36(39.5) mLs\\/kg\\/min. The correlation coefficient of cerebral tissue oxygenation and SVC flow was r = 0.53, p-value 0.005. There was a poor correlation between right and left ventricular output and cTOI which is not surprising considering the influence of intra- and extracardiac shunts. CONCLUSION: There is a positive relationship between cerebral TOI values and SVC flow in the very low birth infant on day one of life.

  14. Effect of sevoflurane and propofol on cerebral oxygen metabolism in cardiopulmonary bypass and postoperative neurological function injury

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhu; Wei-Wei Li

    2016-01-01

    Objective:To study the effect of sevoflurane and propofol on cerebral oxygen metabolism in cardiopulmonary bypass (CPB) and postoperative neurological function injury.Methods:A total of 48 cases of patients who received mitral valve replacement under CPB in our hospital were selected and randomly divided into sevoflurane group (S group) and propofol group (P group) who received sevoflurane-based intravenous inhalational anesthesia and propofol-based total intravenous anesthesia respectively, cerebral oxygen metabolism indexes were determined before CPB started (T0), when nasopharyngeal temperature fell to a constant low temperature (T1), when CPB ended (T2) and 1 h after CPB ended (T3) respectively during operation, and serum neurological function, cardiac function and liver function injury molecules were determined after operation.Results: Intraoperative SjvO2, AVDO2, O2ER and rSO2 were not significantly different between two groups, SjvO2 at T1 significantly increased, AVDO2 and O2ER significantly decreased and rSO2 didn’t change significantly, SjvO2 at T2 significantly decreased, AVDO2 and O2ER significantly increased and rSO2 didn’t change significantly; postoperative serum NSE, S100β, Aβ, Glu, Asp and Gly levels of S group were significantly lower than those of P group, and CK-MB, LDH, cTnI, ALT and AST levels were not significantly different from those of P group.Conclusion:Both sevoflurane and propofol can maintain the balance of cerebral oxygen metabolism in mitral valve replacement under CPB and protect the cardiac function and liver function, but sevoflurane has more ideal protective effect on postoperative neurological function.

  15. PENGGUNAAN LUMPUR AKTIF UNTUK MENURUNKAN KADAR Biological Oxygen Demand (BOD, Chemical Oxygen Demand (COD, dan LOGAM BERAT JENIS TIMBAL (Pb dan CADM IUM (Cd PADA LIMBAH CAIR PENCELUPAN INDUSTRI BATIK

    Directory of Open Access Journals (Sweden)

    RAFICHA RACHMA

    2015-06-01

    Full Text Available In the production process, batik dyeing industry use a lot of water and chemicals in the coloring or dyeing fabric dyeing wastewater batik. Batik dyeing waste industry typically have concentrations of chemical oxygen demand (COD and biological oxygen demand (BOD and heavy metals that exceed quality standards set by the government. In an effort to overcome the problems posed by wastewater, the wastewater treatment process must be done before the waste is discharged into aquatic environment. One of the biological wastewater treatment system that is able to reduce levels of contamination are industrial wastewater is activated sludge system. This research was conducted to determine the optimal time and time effectiveness of treatment with activated sludge to reduce levels of COD, BOD, and Pb in the batik industry wastewater. In this research using activated sludge by taking a fixed volume on sampling from hour o to hour 24 so as to produce organic compounds that remain much lower concentrations can result in COD, BOD, and Pb. This is because the longer the settling time of the volume of waste activated sludge with variable sampling and at the same time a decrease in the percentage levels of COD, BOD, and Pb greater. The results of this research found that activated sludge best influence in lowering the levels of COD, BOD, and Pb. This is due to the activity of microorganisms that have given nutrient and insufficient oxygen in aeration process with the longest time that the ability of the microbes in the sludge to oxidize organic materials with the highest effectiveness in the waste. After going through treatment with activated sludge showed that the optimal time of activated sludge treatment to decrease the levels of COD in wastewater dyeing batik industry is 12 hours, the reduced levels of BOD is 12 hours, and to decrease levels of Pb is 8 hours.

  16. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Gersing, Alexandra S.; Schwaiger, Benedikt J. [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ankenbrank, Monika; Toth, Vivien; Bauer, Jan S.; Zimmer, Claus [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Janssen, Insa [Technical University Munich, Department of Neurosurgery, Munich (Germany); Kooijman, Hendrik [Philips Healthcare, Hamburg (Germany); Wunderlich, Silke [Technical University Munich, Department of Neurology, Munich (Germany); Preibisch, Christine [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Technical University Munich, Department of Neurology, Munich (Germany)

    2015-12-15

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO{sub 2}) has been suggested to be analogous to PET-derived CMRO{sub 2} and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO{sub 2} mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO{sub 2} (rCMRO{sub 2}) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO{sub 2} maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO{sub 2} values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO{sub 2} values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO{sub 2} values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO{sub 2} in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO{sub 2} was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  17. [Research on chemical oxygen demand optical detection method based on the combination of multi-source spectral characteristics].

    Science.gov (United States)

    Wu, Guo-Qing; Bi, Wei-Hong

    2014-11-01

    A novel method based on multi-source spectral characteristics of the combination is proposed for chemical oxygen demand detection. First, the ultraviolet and near infrared spectrum of the actual water samples are collected respectively. After pretreatment of the spectrum data, the features of the spectrum are extracted by the nonnegative matrix factorization algorithm for training after normalization. Particle swarm and least squares support vector machines algorithm are applied to predicting chemical oxygen demand of the validation set of water samples. The effect of spectrum's base number on the predicted results is discussed. The experimental results show that the best base number of the ultraviolet spectrum is 5, the best base number of the near infrared spectrum is 2; The validation set correlation coefficient of the prediction model is 0.999 8, and the root mean square error of prediction is 3.26 mg x L(-1). Experimental results demonstrate that the nonnegative matrix factorization algorithm is more suitable for feature extraction of spectral data, and the least squares support vector machines algorithm as a quantitative model correction method of the actual water samples can get good prediction accuracy with different feature extraction methods (principal component analysis, independent component analysis), spectroscopic methods (ultraviolet spectrum method, near infrared spectrum method) and different combination pattern (data direct combination, combining data first, then feature extraction) respectively.

  18. Quantum dots assisted photocatalysis for the chemiluminometric determination of chemical oxygen demand using a single interface flow system

    Energy Technology Data Exchange (ETDEWEB)

    Silvestre, Cristina I.C.; Frigerio, Christian [Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Rua Anibal Cunha 164, 4099-030, Porto (Portugal); Santos, Joao L.M., E-mail: joaolms@ff.up.pt [Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Rua Anibal Cunha 164, 4099-030, Porto (Portugal); Lima, Jose L.F.C. [Requimte, Department of Chemistry, Faculty of Pharmacy, Porto University, Rua Anibal Cunha 164, 4099-030, Porto (Portugal)

    2011-08-12

    Highlights: {yields} A novel flow method for the determination of chemical oxygen demand is proposed. {yields} CdTe nanocrystals are irradiated with UV light to generate strong oxidizing species. {yields} Reactive species promote a fast catalytic degradation of organic matter. {yields} Luminol is used as a chemiluminescence probe for indirect COD assessment. {yields} A single interface flow system was implemented to automate the assays. - Abstract: A novel flow method for the determination of chemical oxygen demand (COD) is proposed in this work. It relies on the combination of a fully automated single interface flow system, an on-line UV photocatalytic unit and quantum dot (QD) nanotechnology. The developed approach takes advantage of CdTe nanocrystals capacity to generate strong oxidizing species upon irradiation with UV light, which fostered a fast catalytic degradation of the organic compounds. Luminol was used as a chemiluminescence (CL) probe for indirect COD assessment, since it is easily oxidized by the QD generated species yielding a strong CL emission that is quenched in the presence of the organic matter. The proposed methodology allowed the determination of COD concentrations between 1 and 35 mg L{sup -1}, with good precision (R.S.D. < 1.1%, n = 3) and a sampling frequency of about 33 h{sup -1}. The procedure was applied to the determination of COD in wastewater certified reference materials and the obtained results showed an excellent agreement with the certified values.

  19. High removal of chemical and biochemical oxygen demand from tequila vinasses by using physicochemical and biological methods.

    Science.gov (United States)

    Retes-Pruneda, Jose Luis; Davila-Vazquez, Gustavo; Medina-Ramírez, Iliana; Chavez-Vela, Norma Angelica; Lozano-Alvarez, Juan Antonio; Alatriste-Mondragon, Felipe; Jauregui-Rincon, Juan

    2014-08-01

    The goal of this research is to find a more effective treatment for tequila vinasses (TVs) with potential industrial application in order to comply with the Mexican environmental regulations. TVs are characterized by their high content of solids, high values of biochemical oxygen demand (BODs), chemical oxygen demand (COD), low pH and intense colour; thus, disposal of untreated TVs severely impacts the environment. Physicochemical and biological treatments, and a combination of both, were probed on the remediation of TVs. The use of alginate for the physicochemical treatment of TVs reduced BOD5 and COD values by 70.6% and 14.2%, respectively. Twenty white-rot fungi (WRF) strains were tested in TV-based solid media. Pleurotus ostreatus 7992 and Trametes trogii 8154 were selected due to their ability to grow on TV-based solid media. Ligninolytic enzymes' production was observed in liquid cultures of both fungi. Using the selected WRF for TVs' bioremediation, both COD and BOD5 were reduced by 88.7% and 89.7%, respectively. Applying sequential physicochemical and biological treatments, BOD5 and COD were reduced by 91.6% and 93.1%, respectively. Results showed that alginate and selected WRF have potential for the industrial treatment of TVs.

  20. Oxygen supply to the fetal cerebral circulation in hypoplastic left heart syndrome: a simulation study based on the theoretical models of fetal circulation.

    Science.gov (United States)

    Sakazaki, Sayaka; Masutani, Satoshi; Sugimoto, Masaya; Tamura, Masanori; Kuwata, Seiko; Kurishima, Clara; Saiki, Hirofumi; Iwamoto, Yoichi; Ishido, Hirotaka; Senzaki, Hideaki

    2015-03-01

    Hypoxia due to congenital heart diseases (CHDs) adversely affects brain development during the fetal period. Head circumference at birth is closely associated with neuropsychiatric development, and it is considerably smaller in newborns with hypoplastic left heart syndrome (HLHS) than in normal newborns. We performed simulation studies on newborns with CHD to evaluate the cerebral circulation during the fetal period. The oxygen saturation of cerebral blood flow in newborns with CHD was simulated according to a model for normal fetal circulation in late pregnancy. We compared the oxygen saturation of cerebral blood flow between newborns with tricuspid atresia (TA; a disease showing univentricular circulation and hypoplasia of the right ventricle), those with transposition of the great arteries (TGA; a disease showing abnormal mixing of arterial and venous blood), and those with HLHS. The oxygen saturation of cerebral blood flow in newborns with normal circulation was 75.7 %, whereas it was low (49.5 %) in both newborns with HLHS and those with TA. Although the oxygen level is affected by the blood flow through the foramen ovale, the oxygen saturation in newborns with TGA was even lower (43.2 %). These data, together with previous reports, suggest that the cerebral blood flow rate is decreased in newborns with HLHS, and the main cause was strongly suspected to be retrograde cerebral perfusion through a patent ductus arteriosus. This study provides important information about the neurodevelopmental prognosis of newborns with HLHS and suggests the need to identify strategies to resolve this unfavorable cerebral circulatory state in utero.

  1. Restoration of Normal Cerebral Oxygen Consumption with Rapamycin Treatment in a Rat Model of Autism-Tuberous Sclerosis.

    Science.gov (United States)

    Chi, Oak Z; Wu, Chang-Chih; Liu, Xia; Rah, Kang H; Jacinto, Estela; Weiss, Harvey R

    2015-09-01

    Tuberous sclerosis (TSC) is associated with autism spectrum disorders and has been linked to metabolic dysfunction and unrestrained signaling of the mammalian target of rapamycin (mTOR). Inhibition of mTOR by rapamycin can mitigate some of the phenotypic abnormalities associated with TSC and autism, but whether this is due to the mTOR-related function in energy metabolism remains to be elucidated. In young Eker rats, an animal model of TSC and autism, which harbors a germ line heterozygous Tsc2 mutation, we previously reported that cerebral oxygen consumption was pronouncedly elevated. Young (4 weeks) male control Long-Evans and Eker rats were divided into control and rapamycin-treated (20 mg/kg once daily for 2 days) animals. Cerebral regional blood flow ((14)C-iodoantipyrine) and O2 consumption (cryomicrospectrophotometry) were determined in isoflurane-anesthetized rats. We found significantly increased basal O2 consumption in the cortex (8.7 ± 1.5 ml O2/min/100 g Eker vs. 2.7 ± 0.2 control), hippocampus, pons and cerebellum. Regional cerebral blood flow and cerebral O2 extractions were also elevated in all brain regions. Rapamycin had no significant effect on O2 consumption in any brain region of the control rats, but significantly reduced consumption in the cortex (4.1 ± 0.3) and all other examined regions of the Eker rats. Phosphorylation of mTOR and S6K1 was similar in the two groups and equally reduced by rapamycin. Thus, a rapamycin-sensitive, mTOR-dependent but S6K1-independent, signal led to enhanced oxidative metabolism in the Eker brain. We found decreased Akt phosphorylation in Eker but not Long-Evans rat brains, suggesting that this may be related to the increased cerebral O2 consumption in the Eker rat. Our findings suggest that rapamycin targeting of Akt to restore normal cerebral metabolism could have therapeutic potential in tuberous sclerosis and autism.

  2. The preliminary study of Ultraviolet-Irradiated and Oxygenated Blood Transfusion Therapy(UOBT) for Experimental Cerebral Infarction of Animal Brain Model

    Institute of Scientific and Technical Information of China (English)

    Su Xiu-Chu; Feng You-Qi; Zhou gang; Wu jun-yi

    2000-01-01

    In this presented study, we have developed a photochemical model of cerebral in farction in rabbit with stable and reproducible infarct size and extent. This model is similar to the pathological changes in human cerebral infarction. Using this model, therapeutic effects and mechanisms of UOBT on brain ischemic injury were invetigated in rabbits following the photochemical infarcnon The results showed that UOBT could significantly reduce the mtarcted size, and improve the cerebral blood flow compared with the control animals treated with non-u-radiated ad non-oxygenated blood transfusion. These data suggest that the UOBT may have a therapeutic potential for clinical rehabilitation effect in stroke treatment

  3. Examiner's finger-mounted near-infrared spectroscopy is feasible to analyze cerebral and skeletal muscle oxygenation in conscious Chihuahuas

    Science.gov (United States)

    Hiwatashi, Keisuke; Doi, Kimiaki; Mizuno, Risuke; Yokosuka, Makoto

    2017-02-01

    To measure regional saturation of oxygen (rSO2) of hemoglobin and total hemoglobin index (HbI) in the brain (through the molera of the head) and skeletal muscle (musculus gracilis) of conscious Chihuahua dogs using an examiner's finger-mounted near-infrared spectroscopy (NIRS) device, Toccare, we investigated brain and skeletal muscle NIRS in 48 Chihuahuas without severe disease. To measure rSO2 and total HbI, a Toccare probe was placed on the molera of the head and musculus gracilis of each dog for real-time recording. Stable NIRS values were obtained within 10 s. We also examined the effect of anesthesia on rSO2 and total HbI of a Chihuahua. Cerebral rSO2 values (59%±7%) were significantly lower than those obtained at femoral regions (67%±6%), whereas total HbI values in the brain (0.38±0.09) were significantly higher than those of the musculus gracilis (0.20±0.05). Sedation with a combination of medetomidine and ketamine decreased cerebral rSO2 along with a corresponding reduction in heart rate. Sevoflurane anesthesia with 100% O2 maintained rSO2 in the brain with an even lower heart rate. In conclusions, we measured brain and skeletal muscle rSO2 of hemoglobin in conscious Chihuahuas using a newly developed NIRS device, Toccare, and found that changes in cerebral oxygenation levels were associated with administration of anesthetics.

  4. Effect of hypertensive reperfusion on the changes between cerebral oxygen delivery and uptake after cardiac arrest and resuscitation in dogs

    Institute of Scientific and Technical Information of China (English)

    杜权; 马永达; 葛衡江; 刘怀琼; 李阳

    2004-01-01

    Objective: To study the changes between cerebral oxygen (O2) delivery and uptake in dogs resuscitated under normotension or hypertension for 4 h. Methods: The model of ventricular fibrillation of 8 min in 12 dogs was made,followed by open cardiopulmonary resuscitation, reperfnsion with normal or high mean arterial pressure (MAP), and controlled ventilation to 4 h. Animals were randomly assigned into Group NT (normotensive reperfusion, n = 6) and Group HT(hypertensive reperfusion, n = 6). Cerebral arteriovenous (sagittal sinus) O2 content difference (Ca-ssO2) and venous(sagittal sinus) PO2(PssO2) were determined before cardiac arrest (CA) and 30, 60, 120, and 240 min after CA. Results: In Group NT, Ca-ssO2 was lower at 30 min ( P < 0.05) but higher at 240 min ( P < 0.01 ) after CA than that before CA. In Group HT, Ca-ssO2 was not significantly different from that in Group NT before CA but was lower than that in Group NT at 30 min after CA ( P < 0.01 ). Ca-ssO2 was not significantly different in Group NT and HT thereafter. In both groups,PssO2 was both higher at 30 min after reperfnsion ( P < 0.01 ) and at 240 min after reperfnsion lower ( P < 0.05) than those before CA .At 30 min after reperfusion, PssO2 was higher (P<0.01) in Group HT than that in Group NT, with insignificant difference between two groups. Conclusion: Cerebral O2 delivery and uptake are mismatched after CA and resuscitation. Hypertensive reperfusion improves oxygen delivery to the brain early after CA.

  5. 高压氧对急性脑梗死临床应用分析%CLINICAL APPLICATION OF HYPERBARIC OXYGENATION TO ACUTE CEREBRAL INFARCTION

    Institute of Scientific and Technical Information of China (English)

    邵伟波

    2002-01-01

    Objective:To determine the effect of hyperbaric oxygenation(HBO) on treating acute cerebral infarction(ACI). Methods: We randomly divided 60 patients with acute cerebral infarction into the treatment group and the control group. Hyperbaric oxygenation treatment was applied in the treatment group as routine drug therapy was used. The neurological function, living ability, clinical therapeutic effectiveness and hemorrheology changes of pa tients in the two groups before and after treatment were observed and evaluated. Results: The indexes of treatment were obviously improved one month after treatment (P < 0.05 ). Clinical effective rate was 93.3 % in this group,which was obviously higher than that of the control group(P < 0.05). Conclusion: Hyperbaric oxygenation can accelerate the recovery of neurological function of patients with acute cerebral infarction.

  6. Effects of Acute Bleeding Followed by Hydroxyethyl Starch 130/0.4 or a Crystalloid on Propofol Concentrations, Cerebral Oxygenation, and Electroencephalographic and Haemodynamic Variables in Pigs

    Directory of Open Access Journals (Sweden)

    Aura Silva

    2014-01-01

    Full Text Available Bleeding changes the haemodynamics, compromising organ perfusion. In this study, the effects of bleeding followed by replacement with hydroxyethyl starch 130/0.4 (HES or lactated Ringer’s (LR on cerebral oxygenation and electroencephalogram-derived parameters were investigated. Twelve young pigs under propofol-remifentanil anaesthesia were bled 30 mL/kg and, after a 20-minute waiting period, volume replacement was performed with HES (GHES; N=6 or LR (GRL; N=6. Bleeding caused a decrease of more than 50% in mean arterial pressure (P<0.01 and a decrease in cerebral oximetry (P=0.039, bispectral index, and electroencephalogram total power (P=0.04 and P<0.01, resp., while propofol plasma concentrations increased (P<0.01. Both solutions restored the haemodynamics and cerebral oxygenation similarly and were accompanied by an increase in electroencephalogram total power. No differences between groups were found. However, one hour after the end of the volume replacement, the cardiac output (P=0.03 and the cerebral oxygenation (P=0.008 decreased in the GLR and were significantly lower than in GHES (P=0.02. Volume replacement with HES 130/0.4 was capable of maintaining the cardiac output and cerebral oxygenation during a longer period than LR and caused a decrease in the propofol plasma concentrations.

  7. Effects of Acute Bleeding Followed by Hydroxyethyl Starch 130/0.4 or a Crystalloid on Propofol Concentrations, Cerebral Oxygenation, and Electroencephalographic and Haemodynamic Variables in Pigs

    Science.gov (United States)

    Venâncio, Carlos; Souza, Almir P.; Ferreira, Luísa Maria; Branco, Paula Sério; de Pinho, Paula Guedes; Amorim, Pedro; Ferreira, David A.

    2014-01-01

    Bleeding changes the haemodynamics, compromising organ perfusion. In this study, the effects of bleeding followed by replacement with hydroxyethyl starch 130/0.4 (HES) or lactated Ringer's (LR) on cerebral oxygenation and electroencephalogram-derived parameters were investigated. Twelve young pigs under propofol-remifentanil anaesthesia were bled 30 mL/kg and, after a 20-minute waiting period, volume replacement was performed with HES (GHES; N = 6) or LR (GRL; N = 6). Bleeding caused a decrease of more than 50% in mean arterial pressure (P < 0.01) and a decrease in cerebral oximetry (P = 0.039), bispectral index, and electroencephalogram total power (P = 0.04 and P < 0.01, resp.), while propofol plasma concentrations increased (P < 0.01). Both solutions restored the haemodynamics and cerebral oxygenation similarly and were accompanied by an increase in electroencephalogram total power. No differences between groups were found. However, one hour after the end of the volume replacement, the cardiac output (P = 0.03) and the cerebral oxygenation (P = 0.008) decreased in the GLR and were significantly lower than in GHES (P = 0.02). Volume replacement with HES 130/0.4 was capable of maintaining the cardiac output and cerebral oxygenation during a longer period than LR and caused a decrease in the propofol plasma concentrations. PMID:24971192

  8. Hyperbaric oxygen in the treatment of hypertension- induced cerebral hemorrhage on 34 cases%高血压脑出血术后高压氧治疗34例

    Institute of Scientific and Technical Information of China (English)

    程晋成; 沈月萍; 王水平; 吴杨

    2003-01-01

    @@ INTRODUCTION In this study,we investigated effect of hyperbaric oxygen(HBO) on the hypertension- induced basio- cerebral hemorrhage.The affected patients often showed signs of cerebral circulation disorder,spasm of vessels,insufficiency of cerebral blood supply and intracranial hypertension.

  9. Cerebral blood flow and oxygenation in infants after birth asphyxia. Clinically useful information?

    DEFF Research Database (Denmark)

    Greisen, Gorm

    2014-01-01

    perfusion and lack of normal cerebral blood flow regulation are also typically present, but whether the perfusion abnormalities at this secondary stage are detrimental, beneficial, or a mere epiphenomenon remains elusive. In contrast, incomplete reoxygenation of the brain during and following resuscitation...

  10. Near-infrared spectroscopy determined cerebral oxygenation with eliminated skin blood flow in young males

    DEFF Research Database (Denmark)

    Hirasawa, Ai; Kaneko, Takahito; Tanaka, Naoki;

    2016-01-01

    was applied to the temporal artery, estimated O2Hb was not affected by elimination of SkBF during handgrip exercise (P = 0.666) or the cognitive task (P = 0.105). These findings suggest that the algorithm with the individual correction factor allows for evaluation of changes in an accurate cerebral...

  11. Heart rate and oxygen demand of powered exoskeleton–assisted walking in persons with paraplegia

    Directory of Open Access Journals (Sweden)

    Pierre Asselin, MS

    2015-06-01

    Full Text Available Historically, persons with paralysis have limited options for overground ambulation. Recently, powered exoskeletons, which are systems that translate the user’s body movements to activate motors that move the lower limbs through a predetermined gait pattern, have become available. As part of an ongoing clinical study (NCT01454570, eight nonambulatory persons with paraplegia were trained to ambulate with a powered exoskeleton. Measurements of oxygen uptake (VO2 and heart rate (HR were recorded for 6 min each during each maneuver while sitting, standing, and walking. The average value of VO2 during walking (11.2 +/– 1.7 mL/kg/min was significantly higher than for sitting and standing (3.5 +/– 0.4 and 4.3 +/– 0.9 mL/kg/min, respectively; p < 0.001. The HR response during walking was significantly greater than that of either sitting or standing (118 +/– 21 vs 70 +/– 10 and 81 +/– 12 beats per minute, respectively; p < 0.001. Persons with paraplegia were able to ambulate efficiently using the powered exoskeleton for overground ambulation, providing the potential for functional gain and improved fitness.

  12. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Gang; Lou, Yaxian; Pan, Zhiying; Liu, Ya [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Nanjing University of Aeronautics and Astronautics, College of Aivil Aviation, Nanjing, Jiangsu (China); Wen, Jiqiu; Li, Xue; Zhang, Zhe [Medical School of Nanjing University, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing, Jiangsu (China); Lu, Hanzhang [University of Texas Southwestern Medical Center, Advanced Imaging Research Center, Dallas, TX (United States); Liu, Wei [Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong (China); Liu, Hui [Siemens MR NEA Collaboration, Siemens Ltd., Shanghai (China); Chen, Huijuan; Kong, Xiang; Luo, Song; Jiang, Xiaolu; Zhang, Zongjun; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China)

    2016-06-15

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO{sub 2} was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min{sup -1} 100 g{sup -1}, P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO{sub 2} (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O{sub 2} min{sup -1} 100 g{sup -1}, P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO{sub 2}. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO{sub 2}. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO{sub 2}. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  13. Chromium (VI) biosorption and removal of chemical oxygen demand by Spirulina platensis from wastewater-supplemented culture medium.

    Science.gov (United States)

    Magro, Clinei D; Deon, Maitê C; De Rossi, Andreia; Reinehr, Christian O; Hemkemeier, Marcelo; Colla, Luciane M

    2012-01-01

    The inappropriate discharge of wastewater containing high concentrations of toxic metals is a serious threat to the environment. Given that the microalga Spirulina platensis has demonstrated a capacity for chromium VI (Cr (VI) biosorption, we assessed the ideal concentration of chromium-containing wastewater required for maximum removal of Cr (VI) and chemical oxygen demand (COD) from the environment by using this microalga. The Paracas and Leb-52 strains of S. platensis, with initial wastewater concentrations of 0%, 12.5%, 25%, and 50%, were cultured in Zarrouk medium diluted to 50% under controlled air, temperature, and lighting conditions. The cultures were maintained for 28 days, and pH, biomass growth, COD, and Cr (VI) were assessed. The wastewater concentration influenced microalgal growth, especially at high concentrations. Removal of 82.19% COD and 60.92% Cr (VI) was obtained, but the COD removal was greater than the Cr (VI) removal in both strains of S. platensis.

  14. Converting Chemical Oxygen Demand (COD) of Cellulosic Ethanol Fermentation Wastewater into Microbial Lipid by Oleaginous Yeast Trichosporon cutaneum.

    Science.gov (United States)

    Wang, Juan; Hu, Mingshan; Zhang, Huizhan; Bao, Jie

    2017-01-27

    Cellulosic ethanol fermentation wastewater is the stillage stream of distillation column of cellulosic ethanol fermentation broth with high chemical oxygen demand (COD). The COD is required to reduce before the wastewater is released or recycled. Without any pretreatment nor external nutrients, the cellulosic ethanol fermentation wastewater bioconversion by Trichosporon cutaneum ACCC 20271 was carried out for the first time. The major components of the wastewater including glucose, xylose, acetic acid, ethanol, and partial of phenolic compounds could be utilized by T. cutaneum ACCC 20271. In a 3-L bioreactor, 2.16 g/L of microbial lipid accumulated with 55.05% of COD reduced after a 5-day culture of T. cutaneum ACCC 20271 in the wastewater. The fatty acid composition of the derived microbial lipid was similar with vegetable oil, in which it could be used as biodiesel production feedstock. This study will both solve the environmental problem and offer low-cost lipid feedstock for biodiesel production.

  15. Efficiency of some soil bacteria for chemical oxygen demand reduction of synthetic chlorsulfuron solutions under agiated culture conditions.

    Science.gov (United States)

    Erguven, G O; Yildirim, N

    2016-05-30

    This study searches the efficiency of certain soil bacteria on chemical oxygen demand (COD) reduction of synthetic chlorsulfuron solutions under agitated culture conditions. It also aims to determine the turbidity of liquid culture medium with chlorsulfuron during bacterial incubation for 120 hours. As a result the highest and lowest COD removal efficiency of bacteria was determined for Bacillus simplex as 94% and for Micrococcus luteus as 70%, respectively at the end of the 96th hour. It was found that COD removal efficiency showed certain differences depend on the bacterial species. It was also observed that B. simplex had the highest COD removal efficiency and it was a suitable bacterium species for bioremediation of a chlorsulfuron contaminated soils.

  16. Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

    Institute of Scientific and Technical Information of China (English)

    XU Qiu-jin; NIAN Yue-gang; JIN Xiang-can; YAN Chang-zhou; LIU Jin; Jiang Gao-ming

    2007-01-01

    Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.

  17. Oxygen demand for the stabilization of the organic fraction of municipal solid waste in passively aerated bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Kasinski, Slawomir, E-mail: slawomir.kasinski@uwm.edu.pl; Wojnowska-Baryla, Irena

    2014-02-15

    Highlights: • The use of an passively aerated reactor enables effective stabilization of OFMSW. • Convective air flow does not inhibit the aerobic stabilization of waste. • The use of an passively aerated reactor reduces the heat loss due to convection. • The volume of supplied air exceeds 1.7–2.88 times the microorganisms demand. - Abstract: Conventional aerobic waste treatment technologies require the use of aeration devices that actively transport air through the stabilized waste mass, which greatly increases operating costs. In addition, improperly operated active aeration systems, may have the adverse effect of cooling the stabilized biomass. Because active aeration can be a limiting factor for the stabilization process, passive aeration can be equally effective and less expensive. Unfortunately, there are few reports documenting the use of passive aeration systems in municipal waste stabilization. There have been doubts raised as to whether a passive aeration system provides enough oxygen to the organic matter mineralization processes. In this paper, the effectiveness of aeration during aerobic stabilization of four different organic fractions of municipal waste in a reactor with an integrated passive ventilation system and leachate recirculation was analyzed. For the study, four fractions separated by a rotary screen were chosen. Despite the high temperatures in the reactor, the air flow rate was below 0.016 m{sup 3}/h. Using Darcy’s equation, theoretical values of the air flow rate were estimated, depending on the intensity of microbial metabolism and the amount of oxygen required for the oxidation of organic compounds. Calculations showed that the volume of supplied air exceeded the microorganisms demand for oxidation and endogenous activity by 1.7–2.88-fold.

  18. Effects of acetazolamide on cerebral blood flow and brain tissue oxygenation

    DEFF Research Database (Denmark)

    Lassen, N A; Friberg, L; Kastrup, J

    1987-01-01

    decreased gradually to 70% of the control value, indicating hyperventilation. At sea level hyperventilation will not increase brain oxygenation significantly in normal man, as the arterial oxygen content only increases minimally, while CBF is unchanged. At high altitude the beneficial effects...... of acetazolamide on the symptoms of acute mountain sickness may well be due to an improved oxygen supply to the brain, as hyperventilation will, at the low ambient PO2, cause a significant increase of the arterial oxygen content, while CBF presumably is unaffected by the drug. During hypoxia at high altitude...

  19. The effects of graded changes in oxygen and carbon dioxide tension on coronary blood velocity independent of myocardial energy demand.

    Science.gov (United States)

    Boulet, Lindsey M; Stembridge, Mike; Tymko, Michael M; Tremblay, Joshua C; Foster, Glen E

    2016-08-01

    In humans, coronary blood flow is tightly regulated by microvessels within the myocardium to match myocardial energy demand. However, evidence regarding inherent sensitivity of the microvessels to changes in arterial partial pressure of carbon dioxide and oxygen is conflicting because of the accompanied changes in myocardial energy requirements. This study aimed to investigate the changes in coronary blood velocity while manipulating partial pressures of end-tidal CO2 (Petco2) and O2 (Peto2). It was hypothesized that an increase in Petco2 (hypercapnia) or decrease in Peto2 (hypoxia) would result in a significant increase in mean blood velocity in the left anterior descending artery (LADVmean) due to an increase in both blood gases and energy demand associated with the concomitant cardiovascular response. Cardiac energy demand was assessed through noninvasive measurement of the total left ventricular mechanical energy. Healthy subjects (n = 13) underwent a euoxic CO2 test (Petco2 = -8, -4, 0, +4, and +8 mmHg from baseline) and an isocapnic hypoxia test (Peto2 = 64, 52, and 45 mmHg). LADVmean was assessed using transthoracic Doppler echocardiography. Hypercapnia evoked a 34.6 ± 8.5% (mean ± SE; P < 0.01) increase in mean LADVmean, whereas hypoxia increased LADVmean by 51.4 ± 8.8% (P < 0.05). Multiple stepwise regressions revealed that both mechanical energy and changes in arterial blood gases are important contributors to the observed changes in LADVmean (P < 0.01). In summary, regulation of the coronary vasculature in humans is mediated by metabolic changes within the heart and an inherent sensitivity to arterial blood gases.

  20. Real-time changes in brain tissue oxygen during endovascular treatment of cerebral vasospasm

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Bache, Søren; Stavngaard, Trine

    2015-01-01

    minute-by-minute changes in brain tissue oxygen during balloon angioplasty and intraarterial administration of vasodilators in three patients.Our results confirm that endovascular intervention is capable of not only resolving angiographic vasospasm, but also of normalizing values of brain tissue oxygen...

  1. Increase in water column denitrification during the deglaciation controlled by oxygen demand in the eastern equatorial Pacific

    Directory of Open Access Journals (Sweden)

    P. Martinez

    2009-05-01

    Full Text Available Here we present organic export production and isotopic nitrogen results over the last 30 000 years from one core localized off Costa Rica (ODP Site 1242 on the leading edge of the oxygen minimum zone of the Eastern Tropical North Pacific. Marine export production reveals glacial-interglacial variations with low organic matter (total organic carbon and total nitrogen contents during warm intervals, twice more during cold episodes and double peaked maximum during the deglaciation, between ~15.5–18.5 and 11–13 ka BP. When this new export production record is compared with four nearby cores localized within the Eastern Pacific along the Equatorial divergence, a good agreement between all the cores is observed, with the major feature being a maximum of export during the early deglaciation. As for export production, water-column denitrification represented by sedimentary δ15N records along the Eastern tropical North and South Pacific between 15° N and 36° S is coherent as well over the last deglaciation period. The whole isotopic nitrogen profiles indicate that denitrification increased abruptly at 19 ka BP to a maximum during the early deglaciation, confirming a typical Antarctic timing. It is proposed that the increase in export production and then in subsurface oxygen demand lead to an intensification of water-column denitrification within the oxygen minimum zones in the easternmost Pacific at the time of the last deglaciation. The triggering mechanism would have been primarily linked to an increase in preformed nutrients contents feeding the Equatorial Undercurrent driven by the resumption of overturning in the Southern Ocean and the return of nutrients from the deep ocean to the sea-surface. An increase in equatorial wind-driven upwelling of sub-surface nutrient-rich waters could have played the role of an amplifier.

  2. In-situ sediment oxygen demand rates in Hammonton Creek, Hammonton, New Jersey, and Crosswicks Creek, near New Egypt, New Jersey, August-October 2009

    Science.gov (United States)

    Wilson, Timothy P.

    2014-01-01

    Sediment oxygen demand rates were measured in Hammonton Creek, Hammonton, New Jersey, and Crosswicks Creek, near New Egypt, New Jersey, during August through October 2009. These rates were measured as part of an ongoing water-quality monitoring program being conducted in cooperation with the New Jersey Department of Environmental Protection. Oxygen depletion rates were measured using in-situ test chambers and a non-consumptive optical electrode sensing technique for measuring dissolved oxygen concentrations. Sediment oxygen demand rates were calculated on the basis of these field measured oxygen depletion rates and the temperature of the stream water at each site. Hammonton Creek originates at an impoundment, then flows through pine forest and agricultural fields, and receives discharge from a sewage-treatment plant. The streambed is predominantly sand and fine gravel with isolated pockets of organic-rich detritus. Sediment oxygen demand rates were calculated at four sites on Hammonton Creek and were found to range from -0.3 to -5.1 grams per square meter per day (g/m2/d), adjusted to 20 degrees Celsius. When deployed in pairs, the chambers produced similar values, indicating that the method was working as expected and yielding reproducible results. At one site where the chamber was deployed for more than 12 hours, dissolved oxygen was consumed linearly over the entire test period. Crosswicks Creek originates in a marshy woodland area and then flows through woodlots and pastures. The streambed is predominantly silt and clay with some bedrock exposures. Oxygen depletion rates were measured at three sites within the main channel of the creek, and the calculated sediment oxygen demand rates ranged from -0.33 to -2.5 g/m2/d, adjusted to 20 degrees Celsius. At one of these sites sediment oxygen demand was measured in both a center channel flowing area of a pond in the stream and in a stagnant non-flowing area along the shore of the pond where organic-rich bottom

  3. Effects of various anesthetic techniques and PaCO2 levels on cerebral oxygen balance in neurosurgical patients

    Institute of Scientific and Technical Information of China (English)

    陈绍洋; 王强; 熊利泽; 胡胜; 曾祥龙

    2003-01-01

    Objective: To assess the effects of various anesthetic techniques and PaCO2 levels on cerebral oxygen supply/consumption balance during craniotomy for removal of tumors, and to explore an anesthetic technique for neurosurgery and an appropriate degree of PaCO2 during neuroanesthesia. Methods: One hundred and fourteen patients with supratentorial tumors for elective craniotomy, ASA grade Ⅰ-Ⅱ, were randomly allocated to six groups. Patients were anesthetized with continuous intravenous infusion of 2% procaine 1.0 mg*kg-1*min-1 in Group Ⅰ, inhalation of 1.0%-1.5% isoflurane in Group Ⅱ, and infusion of 2% procaine 0.5 mg*kg-1*min-1 combined with inhalation of 0.5%-0.7% isoflurane in Group Ⅲ during the period of study. The end-tidal pressure of CO2 (PET CO2 )was maintained at 4.0 kPa in these 3 groups. In Group Ⅳ, Ⅴ and Ⅵ, the anesthetic technique was the same as that in Group Ⅰ but the PETCO2 was adjusted to 3.5, 4.0 and 4.5 kPa respectively for 60 min during which the study was performed. The radial arterial and retrograde jugular venous blood samples were obtained at the onset and the end of this study for determining jugular venous bulb oxygen saturation (SjvO2), arteriovenous oxygen content difference (AVDO2) and cerebral extraction of oxygen (CEO2). Results: In Group Ⅰ and Ⅲ SjvO2, AVDO2 and CEO2 remained stable. Although SjvO2 kept constant, AVDO2 and CEO2 decreased significantly (P<0.05) in Group Ⅱ. Moreover, AVDO2 and CEO2 in Group Ⅱ were significantly lower than those of Group Ⅲ (P<0.05). In Group Ⅳ, 60 min after hyperventilation, SjvO2 and jugular venous oxygen content(CjvO2) decreased markedly (P<0.01) while CEO2 increased significantly (P<0.01). In addition, SjvO2, CjvO2 and CEO2 in Group Ⅳ were significantly different from the corresponding parameters in Group Ⅴ and Group Ⅵ (P<0.05). In view of sustained excessive hyperventilation, SjvO2 was less than 50% in 37.5% patients of Group Ⅳ. Conclusion: Anesthesia with

  4. Effects of Cortical Spreading Depression on Synaptic Activity, Blood Flow and Oxygen Consumption in Rat Cerebral Cortex

    DEFF Research Database (Denmark)

    Hansen, Henning Piilgaard

    2010-01-01

    As the title of this thesis indicates I have during my PhD studied the effects of cortical spreading depression (CSD) on synaptic activity, blood flow and oxygen consumption in rat cerebral cortex. This was performed in vivo using an open cranial window approach in anesthetized rats. I applied...... two different sets of interneurons. Our data imply that for a given cortical area the amplitude of vascular signals will depend critically on the type of input and hence on the type of neurons activated. In the second study I investigated the effect of cortical spreading depression (CSD) on the evoked...... of neurovascular coupling after topical pretreatment with either inhibitor of CaN pathway (FK506), inhibitor of mPTP formation (NIM811) and combined inhibition of both pathways (FK506+NIM811 or cyclosporin A). A result indicating a potential new treatment aspect for disease states where CSD is known to be involved...

  5. How to Get Hyperbaric Oxygen Therapy for Children with Cerebral Palsy or Brain Injury: Navigating Insurance Denials, Red Tape, and Other Challenges

    Science.gov (United States)

    Console, Richard P., Jr.

    2010-01-01

    Medical professionals who use hyperbaric oxygen therapy (HBOT) say that recent studies, as well as anecdotal evidence, indicate that this treatment significantly improves the lives of many children with cerebral palsy and other types of chronic brain injury. So why do many children with these diagnoses not have access to this treatment? Simply…

  6. In vivo imaging of hemodynamics and oxygen metabolism in acute focal cerebral ischemic rats with laser speckle imaging and functional photoacoustic microscopy

    Science.gov (United States)

    Deng, Zilin; Wang, Zhen; Yang, Xiaoquan; Luo, Qingming; Gong, Hui

    2012-08-01

    Stroke is a devastating disease. The changes in cerebral hemodynamics and oxygen metabolism associated with stroke play an important role in pathophysiology study. But the changes were difficult to describe with a single imaging modality. Here the changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and oxygen saturation (SO2) were yielded with laser speckle imaging (LSI) and photoacoustic microscopy (PAM) during and after 3-h acute focal ischemic rats. These hemodynamic measures were further synthesized to deduce the changes in oxygen extraction fraction (OEF). The results indicate that all the hemodynamics except CBV had rapid declines within 40-min occlusion of middle cerebral artery (MCAO). CBV in arteries and veins first increased to the maximum value of 112.42±36.69% and 130.58±31.01% by 15 min MCAO; then all the hemodynamics had a persistent reduction with small fluctuations during the ischemic. When ischemia lasted for 3 h, CBF in arteries, veins decreased to 17±14.65%, 24.52±20.66%, respectively, CBV dropped to 62±18.56% and 59±18.48%. And the absolute SO2 decreased by 40.52±22.42% and 54.24±11.77%. After 180-min MCAO, the changes in hemodynamics and oxygen metabolism were also quantified. The study suggested that combining LSI and PAM provides an attractive approach for stroke detection in small animal studies.

  7. Changes in cerebral haemodynamics, regional oxygen saturation and amplitude-integrated continuous EEG during hypoxia-ischaemia and reperfusion in newborn piglets

    NARCIS (Netherlands)

    Ioroi, T; Peeters-Scholte, C; Post, [No Value; Groenendaal, F; van Bel, F

    2002-01-01

    Perinatal asphyxia models are necessary to obtain knowledge of the pathophysiology of hypoxia-ischaemia (HI) and to test potential neuroprotective strategies. The present study was performed in newborn piglets to obtain information about simultaneous changes in cerebral oxygenation and haemodynamics

  8. The effect of Sub-maximal exercise-rehabilitation program on cardio-respiratory endurance indexes and oxygen pulse in patients with spastic cerebral palsy

    Directory of Open Access Journals (Sweden)

    M Izadi

    2006-05-01

    Full Text Available Background: Physical or cardio-respiratory fitness are of the best important physiological variables in children with cerebral palsy (CP, but the researches on exercise response of individuals with CP are limited. Our aim was to determine the effect of sub-maximal rehabilitation program (aerobic exercise on maximal oxygen uptake, oxygen pulse and cardio- respiratory physiological variables of children with moderate to severe spastic cerebral palsy diplegia and compare with able-bodied children. Methods: In a controlled clinical trial study, 15 children with diplegia spastic cerebral palsy, were recruited on a voluntarily basis (experimental group and 18 subjects without neurological impairments selected as control group. In CP group, aerobic exercise program performed on the average of exercise intensity (144 beat per minute of heart rate, 3 times a week for 3 months. The time of each exercise session was 20-25 minutes. Dependent variables were measured in before (pretest and after (post test of rehabilitation program through Mac Master Protocol on Tantories cycle ergometer in CP group and compared with the control group. Results: The oxygen pulse (VO2/HR during ergometery protocol was significantly lower in CP group than normal group (P<0.05. No significant statistical difference in maximal oxygen uptake (VO2 max was found between groups. The rehabilitation program leads to little increase of this variable in CP group. After sub-maximal exercise in pretest and post test, the heart rate of patient group was greater than control group, and aerobic exercise leads to significant decrease in heart rate in CP patients(P<0.05. Conclusion: The patients with spastic cerebral palsy, because of high muscle tone, severe spasticity and involuntarily movements have higher energy cost and lower aerobic fitness than normal people. The rehabilitation exercise program can improve physiological function of muscle and cardio-respiratory endurance in these

  9. The Effect of Patient-Specific Cerebral Oxygenation Monitoring on Postoperative Cognitive Function: A Multicenter Randomized Controlled Trial

    Science.gov (United States)

    Ellis, Lucy; Murphy, Gavin J; Culliford, Lucy; Dreyer, Lucy; Clayton, Gemma; Downes, Richard; Nicholson, Eamonn; Stoica, Serban; Reeves, Barnaby C

    2015-01-01

    Background Indices of global tissue oxygen delivery and utilization such as mixed venous oxygen saturation, serum lactate concentration, and arterial hematocrit are commonly used to determine the adequacy of tissue oxygenation during cardiopulmonary bypass (CPB). However, these global measures may not accurately reflect regional tissue oxygenation and ischemic organ injury remains a common and serious complication of CPB. Near-infrared spectroscopy (NIRS) is a noninvasive technology that measures regional tissue oxygenation. NIRS may be used alongside global measures to optimize regional perfusion and reduce organ injury. It may also be used as an indicator of the need for red blood cell transfusion in the presence of anemia and tissue hypoxia. However, the clinical benefits of using NIRS remain unclear and there is a lack of high-quality evidence demonstrating its efficacy and cost effectiveness. Objective The aim of the patient-specific cerebral oxygenation monitoring as part of an algorithm to reduce transfusion during heart valve surgery (PASPORT) trial is to determine whether the addition of NIRS to CPB management algorithms can prevent cognitive decline, postoperative organ injury, unnecessary transfusion, and reduce health care costs. Methods Adults aged 16 years or older undergoing valve or combined coronary artery bypass graft and valve surgery at one of three UK cardiac centers (Bristol, Hull, or Leicester) are randomly allocated in a 1:1 ratio to either a standard algorithm for optimizing tissue oxygenation during CPB that includes a fixed transfusion threshold, or a patient-specific algorithm that incorporates cerebral NIRS monitoring and a restrictive red blood cell transfusion threshold. Allocation concealment, Internet-based randomization stratified by operation type and recruiting center, and blinding of patients, ICU and ward care staff, and outcome assessors reduce the risk of bias. The primary outcomes are cognitive function 3 months after

  10. Optimal concentration and time window for proliferation and differentiation of neural stem cells from embryonic cerebral cortex:5% oxygen preconditioning for 72 hours

    Institute of Scientific and Technical Information of China (English)

    Li-li Yuan; Ying-jun Guan; Deng-dian Ma; Hong-mei Du

    2015-01-01

    Hypoxia promotes proliferation and differentiation of neural stem cells from embryonic day 12 rat brain tissue, but the concentration and time of hypoxic preconditioning are controversial. To address this, we cultured neural stem cells isolated from embryonic day 14 rat cerebral cortex in 5% and 10% oxygenin vitro. MTT assay, neurosphere number, and immunolfuorescent staining found that 5% or 10% oxygen preconditioning for 72 hours improved neural stem cell viability and proliferation. With prolonged hypoxic duration (120 hours), the proportion of apoptotic cells increased. Thus, 5% oxygen preconditioning for 72 hours promotes neural stem cell prolif-eration and neuronal differentiation. Our ifndings indicate that the optimal concentration and duration of hypoxic preconditioning for promoting proliferation and differentiation of neural stem cells from the cerebral cortex are 5% oxygen for 72 hours.

  11. Episodes of apnea and bradycardia in the preterm newborn: impact on cerebral oxygenation measured by near-infrared spectrophotometry

    Science.gov (United States)

    Van Huffel, Sabine; Craemers, Johan; Lenaerts, Bart; Daniels, Hans; Naulaers, Gunnar; Casaer, Paul

    1998-12-01

    The objective of this study is to evaluate the effect of episodes of apneas and/or mild bradycardia (heart rate decreases of 10 to 20% or more) on cerebral oxyhemoglobin (HbO2) and reduced hemoglobin (Hb) concentration as measured by Near Infrared Spectrophotometry (NIRS). Measurements were carried out on 7 preterm infants who experienced apneic and bradycardiac events. It is shown how to characterize these events using time-frequency analysis. In addition to NIRS (performed with a NIRO-500 from Hamamatsu, Japan), the heart rate, ECG, peripheral arterial oxygen saturation (measured at the foot) and respiration (abdominal and thoracic pressure, and nasal airflow) were continuously recorded. The impact of apneic events and periodic breathing on these measurements reveals the clinical relevance of NIRS. In particular, we investigate whether these changes in heart rate and respiration also influence HbO2 and reduced Hb concentration in neonatal brain. These changes are characterized, as well as their relationships with the other simultaneously recorded signals such as peripheral arterial oxygen saturation.

  12. Comparable cerebral oxygenation patterns in younger and older adults during dual-task walking with increasing load

    Directory of Open Access Journals (Sweden)

    Sarah A. Fraser

    2016-10-01

    Full Text Available The neuroimaging literature on dual-task gait clearly demonstrates increased prefrontal cortex (PFC involvement when performing a cognitive task while walking. However, findings from direct comparisons of the cerebral oxygenation patterns of younger (YA and older (OA adults during dual-task walking are mixed and it is unclear how YA and OA respond to increasing cognitive load (difficulty while walking. This functional near infra-red (fNIRS study examined cerebral oxygenation of YA and OA during self-paced dual-task treadmill walking at two different levels of cognitive load (auditory n-back. Changes in accuracy (% as well as oxygenated (HbO and deoxygenated (HbR hemoglobin were examined. For the HbO and HbR measures, eight regions of interest (ROIs were assessed: the anterior and posterior dorsolateral and ventrolateral PFC (aDLPFC, pDLPFC, aVLPFC, pVLPFC in each hemisphere. Nineteen YA (M = 21.83 yrs and 14 OA (M = 66.85 yrs walked at a self-selected pace while performing auditory 1-back and 2-back tasks. Walking alone (single motor: SM and performing the cognitive tasks alone (single cognitive: SC were compared to dual-task walking (DT = SM + SC. In the behavioural data, participants were more accurate in the lowest level of load (1-back compared to the highest (2-back; p ˂ .001. YA were more accurate than OA overall (p = .009, and particularly in the 2-back task (p = .048. In the fNIRS data, both younger and older adults had task effects (SM < DT in specific ROIs for ∆HbO (3 YA, 1 OA and ∆HbR (7 YA, 8 OA. After controlling for walk speed differences, direct comparisons between YA and OA did not reveal significant age differences, but did reveal a difficulty effect in HbO in the left aDLPFC (p = .028 and significant task effects (SM < DT in HbR for 6 of the 8 ROIs. Findings suggest that YA and OA respond similarly to manipulations of cognitive load when walking on a treadmill at a self-selected pace.

  13. Efficiency of horizontal roughing filter in removing nitrate, phosphate and chemical oxygen demand from effluent of waste stabilization pond

    Directory of Open Access Journals (Sweden)

    Seyed Mostafa Khezri

    2015-06-01

    Full Text Available Background: The effective size of the end grain of horizontal roughing filters (HRFs is larger than 2 mm. This study aimed to examine the efficiency of HRFs in removing nitrate, phosphate, and chemical oxygen demand (COD from effluent of a wastewater stabilization pond. Methods: This experimental study was conducted in 2013. The pilot project was transferred to the Karaj wastewater treatment plant (stabilization pond, and the installation, equipping, and start-up of the system began using an effluent treatment plant. Sampling was done from March to August in 3 rates, 0.5, 1 and 1.5 m/h, and included simultaneous sampling from inlet and outlet filtering to determine the concentrations of nitrate, phosphate, and COD. Results: At filtration rates of 0.5, 1, and 1.5 m/h, the average nitrate removal equaled 25%, 32%, and 34%, respectively, average phosphate removal equaled 29%, 26%, and 28%, respectively, and the average COD removal at filtration rates of 0.5, 1, and 1.5 m/h equaled 62%, 66%, and 68%, respectively. Outlet values of phosphate and nitrate were lower than the standards set by the Environmental Standards Organization (ESO (P < 0.05. Conclusion: According to the results of this study, the HRF function was approximately adequate in COD removal, but its efficiency in nitrate and phosphate removal was lower.

  14. Removal of chemical oxygen demand and dissolved nutrients by a sunken lawn infiltration system during intermittent storm events.

    Science.gov (United States)

    Hou, Lizhu; Yang, Huan; Li, Ming

    2014-01-01

    Urban surface water runoff typically contains high but varying amounts of organic matter and nutrients that require removal before reuse. Infiltration systems such as sunken lawns can improve water quality. However, there is currently insufficient information describing the treatment efficiency of lawn-based infiltration systems. In this study, novel sunken lawn infiltration systems (SLISs) were designed and their pollutant removal effectiveness was assessed. The results revealed that SLISs with Poa pratensis and Lolium perenne effectively removed most chemical oxygen demand (CODCr) and dissolved nutrients. Average CODCr, total nitrogen (TN), ammonium-nitrogen (NH4(+)-N) and total phosphorus (TP) concentrations were reduced by 78.93, 66.64, 71.86 and 75.83%, respectively, and the corresponding effluent concentrations met the standard for urban miscellaneous water consumption in China. The NH4(+)-N in the synthetic runoff was shown to be removed by adsorption during the stormwater dosing and nitrification during subsequent dry days, as well as through uptake by plants. Phosphorus was mainly removed by adsorption and chemical precipitation. The NH4(+)-N and phosphorus Langmuir isotherm model fitted the clay loam soil adsorption process better than the Freundlich model. Overall, these results indicate that an SLIS provides an alternative means of removing runoff pollutants owing to its efficiency, easy operation and maintenance.

  15. Statistical Analysis of Reducing Biochemical Oxygen Demand (BOD) on Industrial Rubber Wastewater using Dielectric Barrier Discharge Plasma

    Science.gov (United States)

    Syakur, Abdul; Zaman, Badrus; Yunita Nurmaliakasih, Dias

    2017-04-01

    Dielectric Barrier Discharge plasma (DBD) is one of type non-thermal plasma (non-equilibrium plasma) or can be referred to as cold plasma. In this research, DBD plasma be utilized to reduce organic compounds like Biochemichal oxygen demand in the wastewater rubber processing. In the environment field DBD plasma has been used as a treatment for reducing air pollutants such as gas COx, NOx and HC. In addition DBD plasma have been developed to processed wastewater as an alternative technology in wastewater treatment. DBD plasma appears when the electrode is given a high voltage so that, it will form electric field in the area of the electrodes which allows the ionization and the presence of high-energy electrons in the area. The presence of these electrons will ionize molecules of H2O into active species such as OH•, H• and H2O2. The active species that can oxidize into CO2 and H2O so, BOD that can be degraded. In this research for wastewater treatment used high voltage are 10kV, 11kV, 12kV and 13kV and variations of processing time for 5, 10, 15, 20, and 25 (minutes). By increasing the voltage and extend the contact time then the speed variation of electrons to ionize the greater and more active species to be formed to degrade the pollutants to the maximum. This research used quantitative analysis with statistical analysis using SPSS software.

  16. An integrated mathematical model for chemical oxygen demand (COD) removal in moving bed biofilm reactors (MBBR) including predation and hydrolysis.

    Science.gov (United States)

    Revilla, Marta; Galán, Berta; Viguri, Javier R

    2016-07-01

    An integrated mathematical model is proposed for modelling a moving bed biofilm reactor (MBBR) for removal of chemical oxygen demand (COD) under aerobic conditions. The composite model combines the following: (i) a one-dimensional biofilm model, (ii) a bulk liquid model, and (iii) biological processes in the bulk liquid and biofilm considering the interactions among autotrophic, heterotrophic and predator microorganisms. Depending on the values for the soluble biodegradable COD loading rate (SCLR), the model takes into account a) the hydrolysis of slowly biodegradable compounds in the bulk liquid, and b) the growth of predator microorganisms in the bulk liquid and in the biofilm. The integration of the model and the SCLR allows a general description of the behaviour of COD removal by the MBBR under various conditions. The model is applied for two in-series MBBR wastewater plant from an integrated cellulose and viscose production and accurately describes the experimental concentrations of COD, total suspended solids (TSS), nitrogen and phosphorous obtained during 14 months working at different SCLRs and nutrient dosages. The representation of the microorganism group distribution in the biofilm and in the bulk liquid allow for verification of the presence of predator microorganisms in the second reactor under some operational conditions.

  17. Myocardial oxygen supply/demand ratio in aortic stenosis: hemodynamic and echocardiographic evaluation of patients with and without angina pectoris.

    Science.gov (United States)

    Nadell, R; DePace, N L; Ren, J F; Hakki, A H; Iskandrian, A S; Morganroth, J

    1983-08-01

    Angina pectoris is a common symptom in patients with aortic stenosis without coronary artery disease. To investigate the correlates of angina pectoris, echocardiographic and hemodynamic data from 44 patients with aortic stenosis and no coronary artery disease (mean age 56 +/- 10 years) were analyzed. Twenty-three patients had no angina pectoris and 21 patients had angina pectoris. The ratio of the diastolic pressure-time index (area between the aortic and left ventricular pressure curves during diastole) to the systolic pressure-time index (area under the left ventricular pressure curve during systole), an index of the oxygen supply/demand ratio, was not different in patients with or without angina pectoris. There were no differences between patients with and without angina pectoris in echocardiographically determined wall thickness, chamber size, systolic and diastolic wall stress and left ventricular mass; in electrocardiographically defined voltage; and in hemodynamically defined aortic valve area, transaortic gradient and stroke work index. Thus, echocardiographic and hemodynamic measurements at rest are not significantly different in the presence or absence of angina pectoris in patients with aortic stenosis. Dynamic data appear to be essential for evaluation of the mechanisms of angina pectoris in patients with aortic stenosis.

  18. Semi-specific Microbacterium phyllosphaerae-based microbial sensor for biochemical oxygen demand measurements in dairy wastewater.

    Science.gov (United States)

    Kibena, Elo; Raud, Merlin; Jõgi, Eerik; Kikas, Timo

    2013-04-01

    Although the long incubation time of biochemical oxygen demand (BOD7) measurements has been addressed by the use of microbial biosensors, the resulting sensor-BOD values gained from the measurements with specific industrial wastewaters still underestimates the BOD value of such samples. This research aims to provide fast and more accurate BOD measurements in the dairy wastewater samples. Unlike municipal wastewater, wastewater from the dairy industry contains many substrates that are not easily accessible to a majority of microorganisms. Therefore, a bacterial culture, Microbacterium phyllosphaerae, isolated from dairy wastewater was used to construct a semi-specific microbial biosensor. A universal microbial biosensor based on Pseudomonas fluorescens, which has a wide substrate spectrum but is nonspecific to dairy wastewater, was used as a comparison. BOD biosensors were calibrated with OECD synthetic wastewater, and experiments with different synthetic and actual wastewater samples were carried out. Results show that the semi-specific M. phyllosphaerae-based microbial biosensor is more sensitive towards wastewaters that contain milk derivates and butter whey than the P. fluorescens-based biosensor. Although the M. phyllosphaerae biosensor underestimates the BOD7 value of actual dairy wastewaters by 25-32%, this bacterial culture is more suitable for BOD monitoring in dairy wastewater than P. fluorescens, which underestimated the same samples by 46-61%.

  19. A sensitive ferricyanide-mediated biochemical oxygen demand assay for analysis of wastewater treatment plant influents and treated effluents.

    Science.gov (United States)

    Jordan, Mark A; Welsh, David T; John, Richard; Catterall, Kylie; Teasdale, Peter R

    2013-02-01

    Representative and fast monitoring of wastewater influent and effluent biochemical oxygen demand (BOD) is an elusive goal for the wastewater industry and regulatory bodies alike. The present study describes a suitable assay, which incorporates activated sludge as the biocatalyst and ferricyanide as the terminal electron acceptor for respiration. A number of different sludges and sludge treatments were investigated, primarily to improve the sensitivity of the assay. A limit of detection (LOD) (2.1 mg BOD₅ L⁻¹) very similar to that of the standard 5-day BOD₅ method was achieved in 4 h using raw influent sludge that had been cultured overnight as the biocatalyst. Reducing the microbial concentration was the most effective means to improve sensitivity and reduce the contribution of the sludge's endogenous respiration to total ferricyanide-mediated (FM) respiration. A strong and highly significant relationship was found (n = 33; R = 0.96; p BOD₅ and FM-BOD equivalent values for a diverse range of samples including wastewater treatment plant (WWTP) influent and treated effluent, as well as several grey water samples. The activated sludge FM-BOD assay presented here is an exceptional surrogate method to the standard BOD₅ assay, providing representative, same-day BOD analysis of WWTP samples with a comparable detection limit, a 4-fold greater analytical range and much faster analysis time. The industry appeal of such an assay is tremendous given that ~90% of all BOD₅ analysis is dedicated to measurement of WWTP samples, for which this assay is specifically designed.

  20. Constructed Wetlands Systems Batch: removal of Biochemical Oxygen Demand and pH regulation for treatment dairy effluent

    Directory of Open Access Journals (Sweden)

    Henrique Vieira de Mendonça

    2015-04-01

    Full Text Available This work assessed the effectiveness of using constructed wetlands (CW's to treat dairy effluent. The purpose of the research was to evaluate the influence of substrates and cultivated plants on the efficiency of Biochemical Oxygen Demand (BOD removal and pH regulation in six experimental units operating at pilot scale. Six CW's for dairy sewage treatment were constructed in 100-liter High-Density Polyethylene Ethylene (HDPE tanks. Three constructed wetlands containing fine gravel (0 mm and another three with a mix of 20% sand and 80% fine gravel (0 mm were used in the filtering stage. Four experimental units were planted with the macrophytes Typha dominguensis (cattail and Hedychium coronarium (pond lily, the selected plants for this study, and two others were maintained as control units. A minimum average of 77.8% and a maximum of 95.2% BOD efficiency removal were achieved and a pH range of 5 to 9 was maintained as required by the Brazilian Resolution CONAMA N. 430 /2011 in order to release the effluent into a waterway. The six treatments showed similar removal of biodegradable carbonaceous compounds with no significant differences between the treatments at a 95% confidence level. This work showed that CW’s operating in batch can be used to treat dairy raw water for BOD removal and pH regulation.

  1. A miniature photoelectrochemical sensor based on organic electrochemical transistor for sensitive determination of chemical oxygen demand in wastewaters.

    Science.gov (United States)

    Liao, Jianjun; Lin, Shiwei; Zeng, Min; Yang, Yue

    2016-05-01

    A three-electrode configuration is often required in the conventional photoelectrochemical measurements. Nevertheless, one common drawback is the reference electrode and the counter electrode used in the measurements, which has been proved to be an impediment for the miniaturization. In this study, a simple, cost-effective and miniature photoelectrochemical sensor based on high sensitive organic electrochemical transistor (OECT) is developed and used for the determination of chemical oxygen demand (COD) in wastewaters. The devices show detection limit down to 0.01 mg/L COD, which is two orders of magnitude better than that of the conventional photoelectrochemical method. The excellent sensing performance can be contributed to the novel sensing mechanism of OECT devices. That is, the devices are sensitive to the potential changes induced by the photoelectrochemical reaction on TiO2 nanotube arrays gate electrodes. Real sample analyses are also carried out. The results demonstrate that the measured COD values using the OECT devices and the standard dichromate methods are in a good agreement. Since the proposed sensor is constructed on a miniature transistor, it is expected that the device shows a promising application on the integrated COD monitoring platform.

  2. Immobilizing of catalyst using Bayah's natural zeolite to reduce the chemical oxygen demand (COD) and total organic carbon (TOC)

    Science.gov (United States)

    Jayanudin, Kustiningsih, Indar; Sari, Denni Kartika

    2017-05-01

    Indonesia is rich of natural minerals, many of which had not been widely used. One potential natural mineral is zeolite from Bayah Banten that can be used to support catalyst in the process of waste degradation. The purpose of this research is to characterize the Bayah's zeolite and to figure out the effectiveness of the zeolite as supporting agent to the Fe catalyst in the process of phenol degradation, with the main purposes are to reduce the Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC). This research consists of three steps, activation of natural zeolite using 1M, 2M, and 3M NaOH solution, impregnation process with 0.025M, 0.05 M and 0.075M Fe(NO3)3.9H2O solution, and calcination at 500°C. Bayah's natural zeolite was characterize using Brauner-Emmet-Teller (BET) for its pore area, X-ray Fluorescence (XRF) for analyzing zeolite's component before and after activation process and after impregnation process, and Scanning Electron Microscope (SEM) for analyzing zeolite's morphology. The result showed that the highest pore area was 9Å, Fe metal from Fe(NO3)3.9H2O 0,075 M solution remained in zeolite pore was 7,73%, the reduction of COD and TOC was yielded at H2O2: phenol ratio of 1 : 6.

  3. Inspired Carbon Dioxide During Hypoxia: Effects on Task Performance and Cerebral Oxygen Saturation

    NARCIS (Netherlands)

    Dorp, E. van; Los, M.; Dirven, P.; Sarton, E.; Valk, P.; Teppema, L.; Stienstra, R.; Dahan, A.

    2007-01-01

    Introduction: Exposure to a hypoxic environment has a deleterious effect on physiological and mental functions. We studied the effect of added inspired CO2 during artificially induced hypoxic normobaric hypoxia (oxygen saturation ∼80%) on complex task performance. Methods: In random order, 22 health

  4. Combined administration of hyperbaric oxygen and hydroxocobalamin improves cerebral metabolism after acute cyanide poisoning in rats

    DEFF Research Database (Denmark)

    Hansen, M B; Olsen, Niels Vidiendal; Hyldegaard, O

    2013-01-01

    Hyperbaric oxygen therapy (HBOT) or intravenous hydroxocobalamin (OHCob) both abolish cyanide (CN)-induced surges in interstitial brain lactate and glucose concentrations. HBOT has been shown to induce a delayed increase in whole blood CN concentrations, whereas OHCob may act as an intravascular CN...

  5. Increased cerebral oxygen extraction capacity in patients with Alzheimer’s disease

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Gyldensted, Louise; Nagenthiraja, Kartheeban

    the metabolic requirements of the brain tissues. In this study we investigated the brain oxygen extraction capacity (OEFmax) in AD patients and controls using dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI). Increased OEFmax was detected in the temporal, parietal and frontal lobes of AD...

  6. Analytical determination of Chemical Oxygen Demand in samples considered to be difficult to analyse: solid substrates and liquid samples with high suspended solid concentrations

    DEFF Research Database (Denmark)

    Raposo, Francisco; Fernández-Cegrí, V.; De la Rubia, M.A.

    Chemical oxygen demand (COD) is a critical analytical parameter in the field of waste and wastewater treatment processes, and more specifically in anaerobic digestion processes. However, little is known about the COD measurement quality of anaerobic digestion samples. Taking into account the lack...

  7. Quality improvement in determination of chemical oxygen demand in samples considered difficult to analyze, through participation in proficiency-testing schemes

    DEFF Research Database (Denmark)

    Raposo, Francisco; Fernández-Cegrí, V.; De la Rubia, M.A.

    2010-01-01

    Chemical oxygen demand (COD) is a critical analytical parameter in waste and wastewater treatment, more specifically in anaerobic digestion, although little is known about the quality of measuring COD of anaerobic digestion samples. Proficiency testing (PT) is a powerful tool that can be used...

  8. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Science.gov (United States)

    Simon, Aaron B; Griffeth, Valerie E M; Wong, Eric C; Buxton, Richard B

    2013-01-01

    Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL) and Blood Oxygenation Level Dependent (BOLD) imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO(2)) that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP) estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

  9. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Directory of Open Access Journals (Sweden)

    Aaron B Simon

    Full Text Available Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL and Blood Oxygenation Level Dependent (BOLD imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF and cerebral oxygen metabolism (CMRO(2 that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

  10. Near-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair

    DEFF Research Database (Denmark)

    Sørensen, H.; Nielsen, Henning Morris Bay; Secher, N H

    2016-01-01

    intend to adjust ventilation according end-tidal CO2 tension (EtCO2) and here evaluated to what extent that strategy maintains frontal lobe oxygenation (ScO2) as determined by near infrared spectroscopy. For 44 patients [5 women, aged 70 (48-83) years] ScO2, mean arterial pressure (MAP), EtCO2...... not prevent an increase in ScO2 by 2 % (-1 to 4; P noted in three patients...

  11. [Inhibitor development after early high exposure and cerebral haemorrhage. Costs and factor demand for a successful immunotolerance induction therapy].

    Science.gov (United States)

    Haubold, K; Moorthi, C; Bade, A; Niekrens, C; Auerswald, G

    2010-11-01

    Severe haemophilia A was diagnosed postpartum in a newborn. The mother was known as a conductor (intron 22 inversion) and an uncle had a persistently high titer inhibitor after failed ITI. Due to a cephalhaematoma, a high-dose pdFVIII substitution was given within the first days after birth. At the age of six month a severe cerebral haemorrhage occurred, making a high-dose pdFVIII substitution and neurosurgical intervention necessary. Several days later a porth-a-cath-system was implanted. The development of a high titer inhibitor occured six days later, an ITI was started according to the Bonn Protocol. Initially rFVIIa was given in addition to the pdFVIII substitution. Seven days after the beginning of treatment the inhibitor was no longer detectable. At monthly intervals the FVIII dosage was reduced until the dosage complied with a prophylaxis in severe haemophilia A. The duration of the ITI was nine months. A total of 30 mg rFVIIa and 276000 IU pdFVIII were used; costs in total: 280173.60 Euro.

  12. Reduced blood flow response to acetazolamide reflects pre-existing vasodilation and decreased oxygen metabolism in major cerebral arterial occlusive disease

    Energy Technology Data Exchange (ETDEWEB)

    Yamauchi, Hiroshi; Okazawa, Hidehiko; Kishibe, Yoshihiko; Sugimoto, Kanji; Takahashi, Masaaki [Research Institute, Shiga Medical Center, 5-4-30 Moriyama, Moriyama-city, Shiga 524-8524 (Japan)

    2002-10-01

    A decrease in the cerebral blood flow (CBF) response to acetazolamide may indicate an increase in cerebral blood volume (CBV) caused by reduced perfusion pressure in patients with major cerebral artery steno-occlusive lesions. However, a decrease in cerebral metabolic rate of oxygen (CMRO{sub 2}) caused by ischemic changes may also decrease the CBF response to acetazolamide by decreasing the production of carbon dioxide. The purpose of this study was to determine whether the values of CBV and CMRO{sub 2} are independent predictors of the CBF response to acetazolamide in major cerebral arterial occlusive disease. We used positron emission tomography to study 30 patients with major cerebral artery steno-occlusive lesions. The CBF response to acetazolamide was assessed by measuring baseline CBF and CBF 10 min after an intravenous injection of 1 g of acetazolamide. Multivariate analysis was used to test the independent predictive value of the CBV and CMRO{sub 2} at baseline with respect to the percent change in CBF during acetazolamide administration. Both increased CBV and decreased CMRO{sub 2} were significant and independent predictors of the reduced CBF response to acetazolamide. CBV accounted for 25% of the variance in the absolute change in CBF during acetazolamide administration and 42% of the variance in the percent change in CBF, whereas CMRO{sub 2} accounted for 19% and 4% of the variance, respectively. In patients with major cerebral arterial occlusive disease, a decrease in CMRO{sub 2} may contribute to the reduced CBF response to acetazolamide, although an increase in CBV appears to be the major contributing factor. (orig.)

  13. The effect of chamber mixing velocity on bias in measurement of sediment oxygen demand rates in the Tualatin River basin, Oregon

    Science.gov (United States)

    Doyle, Micelis C.; Rounds, Stewart

    2003-01-01

    Three sediment oxygen demand (SOD) measurement chambers were deployed in the Tualatin River near Tigard, Oregon, at river mile 10 in August 2000. SOD rates were calculated for three different circulation velocities during each chamber deployment. The SOD rate at each velocity was calculated from a graph of dissolved oxygen concentration versus elapsed time. An acoustic doppler current profiler (ADCP) was used to measure stream discharge and near-bottom water velocities in the Tualatin at river mile 10 and at two upstream locations. Measured river and chamber velocities were similar, indicating that results from the chambers were representative of instream effects.

  14. Performance of on-site pilot static granular bed reactor (SGBR) for treating dairy processing wastewater and chemical oxygen demand balance modeling under different operational conditions.

    Science.gov (United States)

    Oh, Jin Hwan; Park, Jaeyoung; Ellis, Timothy G

    2015-02-01

    The performance and operational stability of a pilot-scale static granular bed reactor (SGBR) for the treatment of dairy processing wastewater were investigated under a wide range of organic and hydraulic loading rates and temperature conditions. The SGBR achieved average chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS)-removal efficiencies higher than 90% even at high loading rates up to 7.3 kg COD/m(3)/day, with an hydraulic retention time (HRT) of 9 h, and at low temperatures of 11 °C. The average methane yield of 0.26 L CH4/g COD(removed) was possibly affected by a high fraction of particulate COD and operation at low temperatures. The COD mass balance indicated that soluble COD was responsible for most of the methane production. The reactor showed the capacity of the methanogens to maintain their activity and withstand organic and hydraulic shock loads.

  15. Replacement of chemical oxygen demand (COD) with total organic carbon (TOC) for monitoring wastewater treatment performance to minimize disposal of toxic analytical waste.

    Science.gov (United States)

    Dubber, Donata; Gray, Nicholas F

    2010-10-01

    Chemical oxygen demand (COD) is widely used for wastewater monitoring, design, modeling and plant operational analysis. However this method results in the production of hazardous wastes including mercury and hexavalent chromium. The study examined the replacement of COD with total organic carbon (TOC) for general performance monitoring by comparing their relationship with influent and effluent samples from 11 wastewater treatment plants. Biochemical oxygen demand (BOD5) was also included in the comparison as a control. The results show significant linear relationships between TOC, COD and BOD5 in settled (influent) domestic and municipal wastewaters, but only between COD and TOC in treated effluents. The study concludes that TOC can be reliably used for the generic replacement of both COD (COD=49.2+3.00*TOC) and BOD5 (BOD5=23.7+1.68*TOC) in influent wastewaters but only for COD (COD=7.25+2.99*TOC) in final effluents.

  16. Effects of Repetitive Hyperbaric Oxygen Treatment in Patients with Acute Cerebral Infarction: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Cheng-Hsin Chen

    2012-01-01

    Full Text Available The role of hyperbaric oxygen therapy (HBOT in the treatment of acute ischemic stroke is controversial. This prospective study assessed the efficacy and safety of HBOT as adjuvant treatment on 46 acute ischemic stroke in patients who did not receive thrombolytic therapy. The HBOT group (n=16 received conventional medical treatment with 10 sessions of adjunctive HBOT within 3–5 days after stroke onset, while the control group (n=30 received the same treatment but without HBOT. Early (around two weeks after onset and late (one month after onset outcomes (National Institutes of Health Stroke Scale, NIHSS scores and efficacy (changes of NIHSS scores of HBOT were evaluated. The baseline clinical characteristics were similar in both groups. Both early and late outcomes of the HBOT group showed significant difference (P≤0.001. In the control group, there was only significant difference in early outcome (P=0.004. For early efficacy, there was no difference when comparing changes of NIHSS scores between the two groups (P=0.140 but there was statistically significant difference when comparing changes of NIHSS scores at one month (P≤0.001. The HBOT used in this study may be effective for patients with acute ischemic stroke and is a safe and harmless adjunctive treatment.

  17. Ability of the aquatic fern Azolla to remove chemical oxygen demand and polyphenols from olive mill wastewater

    Directory of Open Access Journals (Sweden)

    Sacchi, Angelo

    2007-03-01

    Full Text Available We investigated the biofiltration ability of the aquatic fern Azolla to remove polyphenols and chemical oxygen demand (COD from olive mill wastewater (OMWw collected from the traditional (TS and continuous (CS extraction systems. Azolla biomass was packed into five sequential Imhoff cones and five sequential columns. In both experiments, the filtrates collected from the 5th biofilter showed a decrease in polyphenol contents: from 7650 mg l–1 to 3610 mg l–1 in TS OMWw and from 3852 mg l–1 to 1351 mg l–1 in CS OMWw. The COD contents decreased from 110200 mg L–1 to 52400 mg L–1 in TS OMWw and from 41600 mg L–1 to 2300 mg L–1 in CS OMWw. A 5:1 OMWw to Azolla-fresh-weight ratio was optimal for both polyphenol and COD removal. The biofiltration ability of alfalfa was compared with that of Azolla, but the treatment with alfalfa did not result in the reduction of COD or polyphenols.La eficacia del helecho de agua azolla para eliminar polifenoles y reducir la demanda química de oxígeno (DQO de los alpechines obtenidos en el proceso de obtención tradicional y continuo del aceite de oliva, fue investigado mediante ensayos de filtración. Cinco conos secuenciales de Imhoff y cinco columnas secuenciales se rellenaron de biomasa de Azolla. En ambos experimentos, el filtrado procedente de la quinta extracción mostró una disminución en el contenido de polifenoles de 7650 mg L–1 a 3610 mg L–1en el alpechín obtenido mediante el sistema tradicional y de 3852 mg L–1 a 1351 mg L–1en el alpechín del sistema continuo. La demanda química de oxígeno del alpechín del sistema tradicional disminuyó de 110200 mg L–1 a 52400 mg L–1 en y de 41600 mg L–1a 2300 mg L–1en el procedente del sistema continuo. Una proporción en peso 5:1 de alpechín: Azolla fue la óptima tanto para la reducción de los polifenoles como para la de la DQO. La eficiencia del tratamiento biológico con alfalfa se comparó con la obtenida con Azolla. Los

  18. Gadd45b prevents autophagy and apoptosis against rat cerebral neuron oxygen-glucose deprivation/reperfusion injury.

    Science.gov (United States)

    He, Guoqian; Xu, Wenming; Tong, Linyan; Li, Shuaishuai; Su, Shiceng; Tan, Xiaodan; Li, Changqing

    2016-04-01

    Autophagic (type II) cell death has been suggested to play pathogenetic roles in cerebral ischemia. Growth arrest and DNA damage response 45b (Gadd45b) has been shown to protect against rat brain ischemia injury through inhibiting apoptosis. However, the relationship between Gadd45b and autophagy in cerebral ischemia/reperfusion (I/R) injury remains uncertain. The aim of this study is to investigate the effect of Gadd45b on autophagy. We adopt the oxygen-glucose deprivation and reperfusion (OGD/R) model of rat primary cortex neurons, and lentivirus interference used to silence Gadd45b expression. Cell viability and injury assay were performed using CCK-8 and LDH kit. Autophagy activation was monitored by expression of ATG5, LC3, Beclin-1, ATG7 and ATG3. Neuron apoptosis was monitored by expression of Bcl-2, Bax, cleaved caspase3, p53 and TUNEL assay. Neuron neurites were assayed by double immunofluorescent labeling with Tuj1 and LC3B. Here, we demonstrated that the expression of Gadd45b was strongly up-regulated at 24 h after 3 h OGD treatment. ShRNA-Gadd45b increased the expression of autophagy related proteins, aggravated OGD/R-induced neuron cell apoptosis and neurites injury. ShRNA-Gadd45b co-treatment with autophagy inhibitor 3-methyladenine (3-MA) or Wortmannin partly inhibited the ratio of LC3II/LC3I, and slightly ameliorated neuron cell apoptosis under OGD/R. Furthermore, shRNA-Gadd45b inhibited the p-p38 level involved in autophagy, but increased the p-JNK level involved in apoptosis. ShRNA-Gadd45b co-treatment with p38 inhibitor obviously induced autophagy. ShRNA-Gadd45b co-treatment with JNK inhibitor alleviated neuron cell apoptosis. In conclusion, our data suggested that Gadd45b inhibited autophagy and apoptosis under OGD/R. Gadd45b may be a common regulatory protein to control autophagy and apoptosis.

  19. Analytical determination of Chemical Oxygen Demand in samples considered to be difficult to analyse: solid substrates and liquid samples with high suspended solid concentrations

    DEFF Research Database (Denmark)

    Raposo, Francisco; Fernández-Cegrí, V.; De la Rubia, M.A.

    Chemical oxygen demand (COD) is a critical analytical parameter in the field of waste and wastewater treatment processes, and more specifically in anaerobic digestion processes. However, little is known about the COD measurement quality of anaerobic digestion samples. Taking into account the lack...... PTs related with COD determination have been organised, and the results reported have been compared; showing the importance of continuous participation in proficiency testing (PT) schemes in order to improve the results obtained....

  20. Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi.

    Science.gov (United States)

    Kahraman, S; Yeşilada, O

    1999-01-01

    Wastewater from olive oil mill was decolorized (and its chemical oxygen demand reduced in static cultivation) using the fungi Coriolus versicolor, Funalia trogii, Phanerochaete chrysosporium and Pleurotus sajor-caju. The effect of cotton stalk on decolorizing and COD removing capability was demonstrated. P. chrysosporium (in 20% medium with cotton stalk) reduced the COD by 48% and color by 58%, F. trogii (in 30% medium with cotton stalk)) by 51 and 55%, respectively.

  1. Cerebral microemboli detected by transcranial doppler in patients treated with extracorporeal membrane oxygenation.

    Science.gov (United States)

    Marinoni, M; Migliaccio, M L; Trapani, S; Bonizzoli, M; Gucci, L; Cianchi, G; Gallerini, A; Tadini Buoninsegni, L; Cramaro, A; Valente, S; Chiostri, M; Peris, A

    2016-08-01

    Cerebrovascular complications rate in patients treated with extracorporeal membrane oxygenation (ECMO) is about 7%. Ischemic stroke may be caused by solid or gaseous microemboli due to thrombosis within the circuit or cannula. Transcranial Doppler (TCD) is the only method able to detect microembolic signals (MES) in real time. The objective of this study was to detect possible MES by TCD in patients treated with veno-venous (VV) and veno-arterial (VA) ECMO and to test for a relation between the number of MES and the 6-month clinical outcome of these patients. This is a monocentric observational prospective study in patients consecutively admitted and treated with ECMO at our regional ECMO referral center in 18 months. TCD detection of MES was performed in patients upon initiation of treatment and then repeated during treatment. Two hundred and forty-eight TCD monitoring were performed in 42 VV and 11 VA ECMO patients. MES were detected in 26.2% of VV ECMO patients and in 81.8% of VA ECMO patients (P < 0.001). In both subgroups of patients, no correlation was found between MES detection and extracorporeal flow velocities or aPTT values. In VA ECMO patients, an inverse correlation between left ventricular ejection fraction and MES grading was found (P = 0.037). In both groups, no clinical neurological impairments correlated to MES detection were found at 6 months follow-up. MES were found in both ECMO configurations; independently from their pathophysiology, MES do not seem to influence clinical outcome. Multicenter studies are still required with more extensive cases to confirm these results. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  2. Reverse engineering of oxygen transport in the lung: adaptation to changing demands and resources through space-filling networks.

    Directory of Open Access Journals (Sweden)

    Chen Hou

    Full Text Available The space-filling fractal network in the human lung creates a remarkable distribution system for gas exchange. Landmark studies have illuminated how the fractal network guarantees minimum energy dissipation, slows air down with minimum hardware, maximizes the gas- exchange surface area, and creates respiratory flexibility between rest and exercise. In this paper, we investigate how the fractal architecture affects oxygen transport and exchange under varying physiological conditions, with respect to performance metrics not previously studied.We present a renormalization treatment of the diffusion-reaction equation which describes how oxygen concentrations drop in the airways as oxygen crosses the alveolar membrane system. The treatment predicts oxygen currents across the lung at different levels of exercise which agree with measured values within a few percent. The results exhibit wide-ranging adaptation to changing process parameters, including maximum oxygen uptake rate at minimum alveolar membrane permeability, the ability to rapidly switch from a low oxygen uptake rate at rest to high rates at exercise, and the ability to maintain a constant oxygen uptake rate in the event of a change in permeability or surface area. We show that alternative, less than space-filling architectures perform sub-optimally and that optimal performance of the space-filling architecture results from a competition between underexploration and overexploration of the surface by oxygen molecules.

  3. Reverse Engineering of Oxygen Transport in the Lung: Adaptation to Changing Demands and Resources through Space-Filling Networks

    Science.gov (United States)

    Hou, Chen; Gheorghiu, Stefan; Huxley, Virginia H.; Pfeifer, Peter

    2010-01-01

    The space-filling fractal network in the human lung creates a remarkable distribution system for gas exchange. Landmark studies have illuminated how the fractal network guarantees minimum energy dissipation, slows air down with minimum hardware, maximizes the gas- exchange surface area, and creates respiratory flexibility between rest and exercise. In this paper, we investigate how the fractal architecture affects oxygen transport and exchange under varying physiological conditions, with respect to performance metrics not previously studied. We present a renormalization treatment of the diffusion-reaction equation which describes how oxygen concentrations drop in the airways as oxygen crosses the alveolar membrane system. The treatment predicts oxygen currents across the lung at different levels of exercise which agree with measured values within a few percent. The results exhibit wide-ranging adaptation to changing process parameters, including maximum oxygen uptake rate at minimum alveolar membrane permeability, the ability to rapidly switch from a low oxygen uptake rate at rest to high rates at exercise, and the ability to maintain a constant oxygen uptake rate in the event of a change in permeability or surface area. We show that alternative, less than space-filling architectures perform sub-optimally and that optimal performance of the space-filling architecture results from a competition between underexploration and overexploration of the surface by oxygen molecules. PMID:20865052

  4. Reverse engineering of oxygen transport in the lung: adaptation to changing demands and resources through space-filling networks.

    Science.gov (United States)

    Hou, Chen; Gheorghiu, Stefan; Huxley, Virginia H; Pfeifer, Peter

    2010-08-26

    The space-filling fractal network in the human lung creates a remarkable distribution system for gas exchange. Landmark studies have illuminated how the fractal network guarantees minimum energy dissipation, slows air down with minimum hardware, maximizes the gas- exchange surface area, and creates respiratory flexibility between rest and exercise. In this paper, we investigate how the fractal architecture affects oxygen transport and exchange under varying physiological conditions, with respect to performance metrics not previously studied.We present a renormalization treatment of the diffusion-reaction equation which describes how oxygen concentrations drop in the airways as oxygen crosses the alveolar membrane system. The treatment predicts oxygen currents across the lung at different levels of exercise which agree with measured values within a few percent. The results exhibit wide-ranging adaptation to changing process parameters, including maximum oxygen uptake rate at minimum alveolar membrane permeability, the ability to rapidly switch from a low oxygen uptake rate at rest to high rates at exercise, and the ability to maintain a constant oxygen uptake rate in the event of a change in permeability or surface area. We show that alternative, less than space-filling architectures perform sub-optimally and that optimal performance of the space-filling architecture results from a competition between underexploration and overexploration of the surface by oxygen molecules.

  5. The effects of different ventilator modes on cerebral tissue oxygen saturation in patients with bidirectional superior cavopulmonary connection

    Directory of Open Access Journals (Sweden)

    Ayda Türköz

    2014-01-01

    Full Text Available Aims and Objectives: We used near-infrared spectroscopy to document changes in cerebral tissue oxygen saturation (SctO 2 in response to ventilation mode alterations after bidirectional Glenn (BDG; superior cavopulmonary connection procedure. We also determined whether spontaneous ventilation have a beneficial effect on hemodynamic status, lactate and SctO 2 when compared with other ventilation modes. Materials and Methods: 20 consecutive patients undergoing BDG were included. We measured SctO 2 during three ventilator modes (intermittent positive-pressure ventilation [IPPV]; synchronized intermittent mandatory ventilation [SIMV]; and continuous positive airway pressure + pressure support ventilation [CPAP + PSV]. We, also, measured mean airway pressure (AWP, arterial blood gases, lactate and systolic arterial pressures (SAP. Results: There was no change in SctO 2 in IPPV and SIMV modes; the SctO 2 measured during CPAP + PSV and after extubation increased significantly (60.5 ± 11, 61 ± 10, 65 ± 10, 66 ± 11 respectively ( P < 0.05. The differences in the SAP measured during IPPV and SIMV modes was insignificant; the SAP increased significantly during CPAP + PSV mode and after extubation compared with IPPV and SIMV (109 ± 11, 110 ± 12, 95 ± 17, 99 ± 13 mmHg, respectively ( P < 0.05. Mean AWP did not change during IPPV and SIMV modes, mean AWP decreased significantly during CPAP + PSV mode (14 ± 4, 14 ± 3, 10 ± 1 mmHg, respectively ( P < 0.01. Conclusions: The SctO 2 was higher during CPAP + PSV ventilation and after extubation compared to IPPV and SIMV modes of ventilation. The mean AWP was lower during CPAP + PSV ventilation compared to IPPV and SIMV modes of ventilation.

  6. Effects of oxygen and glucose deprivation on the expression and distribution of neuronal and inducible nitric oxide synthases and on protein nitration in rat cerebral cortex.

    Science.gov (United States)

    Alonso, David; Serrano, Julia; Rodríguez, Ignacio; Ruíz-Cabello, Jesús; Fernández, Ana Patricia; Encinas, Juan Manuel; Castro-Blanco, Susana; Bentura, María Luisa; Santacana, María; Richart, Ana; Fernández-Vizarra, Paula; Uttenthal, Lars Otto; Rodrigo, José

    2002-02-04

    Changes in the nitric oxide (NO) system of the rat cerebral cortex were investigated by immunohistochemistry, immunoblotting, NO synthase (NOS) activity assay, and magnetic resonance imaging (MRI) in an experimental model of global cerebral ischemia and reperfusion. Brains were perfused transcardially with an oxygenated plasma substitute and subjected to 30 minutes of oxygen and glucose deprivation, followed by reperfusion for up to 12 hours with oxygenated medium containing glucose. A sham group was perfused without oxygen or glucose deprivation, and a further group was treated with the NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) before and during perfusion. Global ischemia led to cerebrocortical injury as shown by diffusion MRI. This was accompanied by increasing morphologic changes in the large type I interneurons expressing neuronal NOS (nNOS) and the appearance of nNOS immunoreactivity in small type II neurons. The nNOS-immunoreactive band and calcium-dependent NOS activity showed an initial increase, followed by a fall after 6 hours of reperfusion. Inducible NOS immunoreactivity appeared in neurons, especially pyramidal cells of layers IV-V, after 4 hours of reperfusion, with corresponding changes on immunoblotting and in calcium-independent NOS activity. Immunoreactive protein nitrotyrosine, present in the nuclear area of neurons in nonperfused controls and sham-perfused animals, showed changes in intensity and distribution, appearing in the neuronal processes during the reperfusion period. Prior and concurrent L-NAME administration blocked the changes on diffusion MRI and attenuated the morphologic changes, suggesting that NO and consequent peroxynitrite formation during ischemia-reperfusion contributes to cerebral injury.

  7. Neuroprotective effects of the AMPA antagonist PNQX in oxygen-glucose deprivation in mouse hippocampal slice cultures and global cerebral ischemia in gerbils

    DEFF Research Database (Denmark)

    Montero, Maria; Nielsen, Marianne; Rønn, Lars Christian B;

    2007-01-01

    PNQX (9-methyl-amino-6-nitro-hexahydro-benzo(F)quinoxalinedione) is a selective AMPA antagonist with demonstrated neuroprotective effects in focal ischemia in rats. Here we report corresponding effects in mouse hippocampal slice cultures subjected to oxygen and glucose deprivation (OGD......) and in transient global cerebral ischemia in gerbils. For in vitro studies, hippocampal slice cultures derived from 7-day-old mice and grown for 14 days, were submersed in oxygen-glucose deprived medium for 30 min and exposed to PNQX for 24 h, starting together with OGD, immediately after OGD, or 2 h after OGD...... ischemia in gerbils in vivo and oxygen-glucose deprivation in mouse hippocampal slice cultures....

  8. Multichannel near infrared spectroscopy indicates regional variations in cerebral autoregulation in infants supported on extracorporeal membrane oxygenation

    Science.gov (United States)

    Papademetriou, Maria D.; Tachtsidis, Ilias; Elliot, Martin J.; Hoskote, Aparna; Elwell, Clare E.

    2012-06-01

    Assessing noninvasively cerebral autoregulation, the protective mechanism of the brain to maintain constant cerebral blood flow despite changes in blood pressure, is challenging. Infants on life support system (ECMO) for cardiorespiratory failure are at risk of cerebral autoregulation impairment and consequent neurological problems. We measured oxyhaemoglobin concentration (HbO2) by multichannel (12 channels) near-infrared spectroscopy (NIRS) in six infants during sequential changes in ECMO flow. Wavelet cross-correlation (WCC) between mean arterial pressure (MAP) and HbO2 was used to construct a time-frequency representation of the concordance between the two signals to assess the nonstationary aspect of cerebral autoregulation and investigate regional variations. Group data showed that WCC increases with decreasing ECMO flow indicating higher concordance between MAP and HbO2 and demonstrating loss of cerebral autoregulation at low ECMO flows. Statistically significant differences in WCC were observed between channels placed on the right and left scalp with channels on the right exhibiting higher values of WCC suggesting that the right hemisphere was more susceptible to disruption of cerebral autoregulation. Multichannel NIRS in conjunction with wavelet analysis methods can be used to assess regional variations in dynamic cerebral autoregulation with important clinical application in the management of critically ill children on life support systems.

  9. Effects of pH management during deep hypothermic bypass on cerebral oxygenation:alpha-stat versus pH-stat

    Institute of Scientific and Technical Information of China (English)

    郦志军; 尹小妹; 叶箭

    2004-01-01

    Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study examined cortical blood flow (CBF), cerebral oxygenation, and brain oxygen consumption in relation to deep hypothermic CPB with alpha-stat or pH-stat management. Methods: Twenty-two pigs were cooled with alpha-stat or pH-stat during CPB to 15℃ esophageal temperature. CBF and cerebral oxygenation were measured continuously with a laser flowmeter and near-infrared spectroscopy, respectively. Brain oxygen consumption was measured with standard laboratory techniques. Results: During CPB cooling, CBF was significantly decreased, about 52.2%±6.3% (P<0.01 vs 92.6%±6.5% of pH-stat) at 15℃ in alpha-stat,whereas there were no significant changes in CBF in pH-stat. While cooling down, brain oxygen extraction (OER) progressively decreased, about 9.5%±0.9% and 10.9%±1.5% at 15 ℃ in alpha-stat and pH-stat, respectively. At 31℃ the decreased value in pH-stat was lower than in alpha-stat (29.9%±2.7% vs 22.5%±1.9%; P<0.05). The ratio of CBF/OER were 2.0±0.3 in alpha-stat and pH-stat, respectively; it was kept in constant level in alpha-stat, and significantly increased by 19℃ to 15℃ in pH-stat (4.9±0.9 vs 2.3±0.4; P<0.01). In mild hypothermia, cerebral oxyhemoglobin and oxygen saturation in alpha-stat were greater than that in pH-stat (102.5%±1.4% vs 99.1%±0.7%; P<0.05). In deep hypothermia, brain oxygen saturation in pH-stat was greater than that in alpha-stat (99.2%±1.0% vs 93.8%±1.0%; P<0.01), and deoxyhemoglobin in pH-stat decreased more greatly than that in alpha-stat (28.7%±6.8% vs 54.1%±4.7%; P<0.05). Conclusions: In mild hypothermic CPB, brain tissue oxygen saturation was greater in alpha-stat than in pH-stat. However, cerebral oxygenation and brain tissue oxygen saturation were better in pH-stat than in alpha-stat during

  10. Atrial supply-demand balance in healthy adult pigs: coronary blood flow, oxygen extraction, and lactate production during acute atrial fibrillation.

    Science.gov (United States)

    van Bragt, Kelly A; Nasrallah, Hussein M; Kuiper, Marion; Luiken, Joost J; Schotten, Ulrich; Verheule, Sander

    2014-01-01

    Little is known about how atrial oxygen supply responds to increased demand, and under which conditions it falls short (supply-demand mismatch). Here, we have investigated the vasodilator response, oxygen extraction, and lactate production of the left atrium (LA) and left ventricle (LV) in response to atrial pacing and atrial fibrillation (AF). Series A (n = 9 Dutch landrace pigs) was instrumented to measure LA and LV vascular conductance in branches of the circumflex artery. Coronary conductance reserve (CCR) was calculated as the ratio between conductance during adenosine infusion and baseline. Series B (n = 7) was instrumented with sampling catheters in LA and LV veins for determination of blood gases and lactate levels. LA CCR (1.76 ± 0.14) was significantly lower than LV CCR (3.16 ± 0.27, P = 0.002). However, basal oxygen extraction was lower in LA (27 ± 3%) than that in the LV (58 ± 6%, P = 0.0006), indicating a larger extraction reserve in the LA than that in the LV (4.68 ± 0.84 vs. 1.88 ± 0.26, P = 0.01). Atrial pacing caused an increase in LA conductance (Series A) and oxygen extraction (Series B). AF increased LA vascular conductance to 177 ± 14% at 1 min, 168 ± 14 at 5 min, and 164 ± 31% at 10 min of AF (P < 0.05 vs. baseline). Atrial oxygen extraction also increased from 26 ± 3% at baseline to 63 ± 5% (P < 0.01) at 5 min and 60 ± 11% (P < 0.01) at 10 min of AF. Arterio-venous lactate difference increased significantly (P = 0.02) during AF. In healthy pigs, the LA has a lower CCR, but a higher extraction reserve compared with the LV. Although both reserves were recruited during AF, atrial lactate production increased significantly.

  11. Effects of the Oxygen-Carrying Solution OxyVita C on the Cerebral Microcirculation and Systemic Blood Pressures in Healthy Rats

    Directory of Open Access Journals (Sweden)

    Rania Abutarboush

    2014-11-01

    Full Text Available The use of hemoglobin-based oxygen carriers (HBOC as oxygen delivering therapies during hypoxic states has been hindered by vasoconstrictive side effects caused by depletion of nitric oxide (NO. OxyVita C is a promising oxygen-carrying solution that consists of a zero-linked hemoglobin polymer with a high molecular weight (~17 MDa. The large molecular weight is believed to prevent extravasation and limit NO scavenging and vasoconstriction. The aim of this study was to assess vasoactive effects of OxyVita C on systemic blood pressures and cerebral pial arteriole diameters. Anesthetized healthy rats received four intravenous (IV infusions of an increasing dose of OxyVita C (2, 25, 50, 100 mg/kg and hemodynamic parameters and pial arteriolar diameters were measured pre- and post-infusion. Normal saline was used as a volume-matched control. Systemic blood pressures increased (P ≤ 0.05 with increasing doses of OxyVita C, but not with saline. There was no vasoconstriction in small (<50 µm and medium-sized (50–100 µm pial arterioles in the OxyVita C group. In contrast, small and medium-sized pial arterioles vasoconstricted in the control group. Compared to saline, OxyVita C showed no cerebral vasoconstriction after any of the four doses evaluated in this rat model despite increases in blood pressure.

  12. Feasibility of mapping the tissue mass corrected bioscale of cerebral metabolic rate of oxygen consumption using 17-oxygen and 23-sodium MR imaging in a human brain at 9.4 T.

    Science.gov (United States)

    Atkinson, Ian C; Thulborn, Keith R

    2010-06-01

    The reduction of molecular oxygen to water is the final step of oxidative phosphorylation that couples adenosine triphosphate production to the reoxidation of reducing equivalents formed during the oxidation of glucose to carbon dioxide. This coupling makes the cerebral metabolic rate of oxygen consumption (CMRO(2)) an excellent reflection of the metabolic health of the brain. A multi-nuclear magnetic resonance (MR) imaging based method for CMRO(2) mapping is proposed. Oxygen consumption is determined by applying a new three-phase metabolic model for water generation and clearance to the changing 17-oxygen ((17)O) labeled water MR signal measured using quantitative (17)O MR imaging during inhalation of (17)O-enriched oxygen gas. These CMRO(2) data are corrected for the regional brain tissue mass computed from quantitative 23-sodium MR imaging of endogenous tissue sodium ions to derive quantitative results of oxygen consumption in micromoles O(2)/g tissue/minute that agree with literature results reported from positron emission tomography. The proposed technique is demonstrated in the human brain using a 9.4 T MR scanner optimized for human brain imaging.

  13. Use of a Short-Acting β1 Blocker During Endotoxemia May Reduce Cerebral Tissue Oxygenation if Hemodynamics are Depressed by a Decrease in Heart Rate.

    Science.gov (United States)

    Kurita, Tadayoshi; Kawashima, Shingo; Morita, Koji; Nakajima, Yoshiki

    2017-06-01

    A decrease in heart rate (HR) using a short-acting β blocker has potential benefits in sepsis; however, depression of hemodynamics and reduction of cerebral oxygenation may also occur in endotoxemia. Seventeen swine were allocated to landiolol or control groups. In the landiolol group, the dose was sequentially changed from 0 to 40 to 200 μg kg min, and stopped. Hemodynamics, blood variables, and the cerebral tissue oxygenation index (TOI) were recorded by near infrared spectroscopy at each dose. Lipopolysaccharide (LPS) was then administered continuously at 1 μg kg h after a 100 μg bolus administration. After 30 and 150 min, as two severity stages of endotoxemia (endotoxemia 1 and 2), landiolol was administered as above and measurements were made. In the control group, landiolol was not administered, but measurements were made. LPS increased HR and landiolol decreased HR, with similar effects in each endotoxemia stage. In endotoxemia 1, LPS decreased stroke volume (SV), but landiolol restored SV to a value similar to that before endotoxemia, and did not decrease cardiac output (CO), even at 200 μg kg min. In contrast, landiolol did not restore SV in endotoxemia 2, resulting in a decrease in CO and mean arterial pressure, accompanied with a dose-dependent decrease in TOI. A short-acting β blocker has various hemodynamic effects in endotoxemia. Use of a short-acting β blocker during endotoxemia may reduce cerebral tissue oxygenation if hemodynamics are depressed by a decrease in HR.

  14. Use of a Short-Acting β1 Blocker During Endotoxemia May Reduce Cerebral Tissue Oxygenation if Haemodynamics are Depressed by a Decrease in Heart Rate.

    Science.gov (United States)

    Kurita, Tadayoshi; Kawashima, Shingo; Morita, Koji; Nakajima, Yoshiki

    2016-11-15

    A decrease in heart rate (HR) using a short-acting β blocker has potential benefits in sepsis; however, depression of haemodynamics and reduction of cerebral oxygenation may also occur in endotoxemia. Seventeen swine were allocated to landiolol or control groups. In the landiolol group, the dose was sequentially changed from 0 to 40 to 200 μg kg min, and stopped. Haemodynamics, blood variables and the cerebral tissue oxygenation index (TOI) were recorded by near infrared spectroscopy at each dose. Lipopolysaccharide (LPS) was then administered continuously at 1 μg kg h after a 100 μg bolus administration. After 30 and 150 min, as two severity stages of endotoxemia (endotoxemia 1 and 2), landiolol was administered as above and measurements were made. In the control group, landiolol was not administered, but measurements were made. LPS increased HR and landiolol decreased HR, with similar effects in each endotoxemia stage. In endotoxemia 1, LPS decreased stroke volume (SV), but landiolol restored SV to a value similar to that before endotoxemia, and did not decrease cardiac output (CO), even at 200 μg kg min. In contrast, landiolol did not restore SV in endotoxemia 2, resulting in a decrease in CO and mean arterial pressure (MAP), accompanied with a dose-dependent decrease in TOI. A short-acting β blocker has various haemodynamic effects in endotoxemia. Use of a short-acting β blocker during endotoxemia may reduce cerebral tissue oxygenation if haemodynamics are depressed by a decrease in HR.

  15. Renal Doppler Resistive Index as a Marker of Oxygen Supply and Demand Mismatch in Postoperative Cardiac Surgery Patients

    Directory of Open Access Journals (Sweden)

    Francesco Corradi

    2015-01-01

    Full Text Available Background and Objective. Renal Doppler resistive index (RDRI is a noninvasive index considered to reflect renal vascular perfusion. The aim of this study was to identify the independent hemodynamic determinants of RDRI in mechanically ventilated patients after cardiac surgery. Methods. RDRI was determined in 61 patients by color and pulse Doppler ultrasonography of the interlobar renal arteries. Intermittent thermodilution cardiac output measurements were obtained and blood samples taken from the tip of pulmonary artery catheter to measure hemodynamics and mixed venous oxygen saturation (SvO2. Results. By univariate analysis, RDRI was significantly correlated with SvO2, oxygen extraction ratio, left ventricular stroke work index, and cardiac index, but not heart rate, central venous pressure, mean artery pressure, pulmonary capillary wedge pressure, systemic vascular resistance index, oxygen delivery index, oxygen consumption index, arterial lactate concentration, and age. However, by multivariate analysis RDRI was significantly correlated with SvO2 only. Conclusions. The present data suggests that, in mechanically ventilated patients after cardiac surgery, RDRI increases proportionally to the decrease in SvO2, thus reflecting an early vascular response to tissue hypoxia.

  16. Renal Doppler Resistive Index as a Marker of Oxygen Supply and Demand Mismatch in Postoperative Cardiac Surgery Patients.

    Science.gov (United States)

    Corradi, Francesco; Brusasco, Claudia; Paparo, Francesco; Manca, Tullio; Santori, Gregorio; Benassi, Filippo; Molardi, Alberto; Gallingani, Alan; Ramelli, Andrea; Gherli, Tiziano; Vezzani, Antonella

    2015-01-01

    Renal Doppler resistive index (RDRI) is a noninvasive index considered to reflect renal vascular perfusion. The aim of this study was to identify the independent hemodynamic determinants of RDRI in mechanically ventilated patients after cardiac surgery. RDRI was determined in 61 patients by color and pulse Doppler ultrasonography of the interlobar renal arteries. Intermittent thermodilution cardiac output measurements were obtained and blood samples taken from the tip of pulmonary artery catheter to measure hemodynamics and mixed venous oxygen saturation (SvO2). By univariate analysis, RDRI was significantly correlated with SvO2, oxygen extraction ratio, left ventricular stroke work index, and cardiac index, but not heart rate, central venous pressure, mean artery pressure, pulmonary capillary wedge pressure, systemic vascular resistance index, oxygen delivery index, oxygen consumption index, arterial lactate concentration, and age. However, by multivariate analysis RDRI was significantly correlated with SvO2 only. The present data suggests that, in mechanically ventilated patients after cardiac surgery, RDRI increases proportionally to the decrease in SvO2, thus reflecting an early vascular response to tissue hypoxia.

  17. Improving the simultaneous removal of chemical oxygen demand and terephthalic acid in a cross-flow aerobic sludge reactor by using response surface methodology.

    Science.gov (United States)

    Hu, Dong-Xue; Tian, Yu; Chen, Zhao-Bo; Ge, Hui; Cui, Yu-Bo; Ran, Chun-Qiu

    2015-01-01

    Central composite design and response surface methodology (RSM) were implemented to optimize the operational parameters for a cross-flow aerobic sludge reactor (CFASR) in remedying mixed printing and dyeing wastewater (MPDW). The individual and interactive effects of three variables, hydraulic retention time (HRT), pH and sludge loading rate (SLR), on chemical oxygen demand (COD) and terephthalic acid (TA) removal rates were evaluated. For HRT of 15.3-19.8 hours, pH of 7.2-8.1 and SLR of 0.4-0.6 kg chemical oxygen demand (COD) per kg mixed liquor suspended solids per day, COD and TA removal rates of the CFASR exceeded 85% and 90%, respectively. The check experiment revealed that the effluent from the optimized CFASR was stable below the limitation of 100 mg COD/L and the TA concentration decreased by 6.0% compared to the usual CFASR. The results verified that the RSM was useful for optimizing the operation parameters of the CFASR in remedying MPDW.

  18. Cerebral blood flow and oxygen metabolism in patients with dementia of the Alzheimer's type by position emission tomography using 0-15 steady state technique

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Shizuki; Kitamura, Shin; Ujike, Takashi; Terashi, Akiro; Iio, Masaaki.

    1988-07-01

    In 12 patients with dementia of the Alzheimer's type (DAT) and 5 age-matched healthy subjects, regional cerebral blood flow (rCBF), oxygen extraction fraction (rOEF), and cerebral oxygen consumption (rCMRO/sub 2/) were determined using positron emission tomography (PET) with 0-15 labeled CO/sub 2/ and O/sub 2/ inhalation method. There was a significant reduction in CMRO/sub 2/ of the temporal cortex in the group of mild DAT compared with the control group. In the group of moderate DAT, CBF of the temporal cortex and CMRO/sub 2/ of the temporal and parietal cortices were significantly reduced. The group of severe DAT showed a significantly reduced CBF and CMRO/sub 2/ in the frontal cortex, and a relatively spared occipital cortex in all stages. The results indicated that metabolic reduction in the temporal cortex first occurs, and that metabolic dysfunction in the parietal and frontal cortices results in blood flow reduction and deterioration of DAT. Right/left metabolic asymmetry in the temporal and parietal cortices was correlated with language and visuospatial functions. (Namekawa, K).

  19. Regional differences in the coupling of cerebral blood flow and oxygen metabolism changes in response to activation: implications for BOLD-fMRI.

    Science.gov (United States)

    Ances, Beau M; Leontiev, Oleg; Perthen, Joanna E; Liang, Christine; Lansing, Amy E; Buxton, Richard B

    2008-02-15

    Functional magnetic resonance imaging (fMRI) based on blood oxygenation level dependent (BOLD) signal changes is a sensitive tool for mapping brain activation, but quantitative interpretation of the BOLD response is problematic. The BOLD response is primarily driven by cerebral blood flow (CBF) changes, but is moderated by M, a scaling parameter reflecting baseline deoxyhemoglobin, and n, the ratio of fractional changes in CBF to cerebral metabolic rate of oxygen consumption (CMRO(2)). We compared M and n between cortical (visual cortex, VC) and subcortical (lentiform nuclei, LN) regions using a quantitative approach based on calibrating the BOLD response with a hypercapnia experiment. Although M was similar in both regions (~5.8%), differences in n (2.21+/-0.03 in VC and 1.58+/-0.03 in LN; Cohen d=1.71) produced substantially weaker (~3.7x) subcortical than cortical BOLD responses relative to CMRO(2) changes. Because of this strong sensitivity to n, BOLD response amplitudes cannot be interpreted as a quantitative reflection of underlying metabolic changes, particularly when comparing cortical and subcortical regions.

  20. Improved light collection and wavelet de-noising enable quantification of cerebral blood flow and oxygen metabolism by a low-cost, off-the-shelf spectrometer

    Science.gov (United States)

    Diop, Mamadou; Wright, Eric; Toronov, Vladislav; Lee, Ting-Yim; St. Lawrence, Keith

    2014-05-01

    Broadband continuous-wave near-infrared spectroscopy (CW-NIRS) is an attractive alternative to time-resolved and frequency-domain techniques for quantifying cerebral blood flow (CBF) and oxygen metabolism in newborns. However, efficient light collection is critical to broadband CW-NIRS since only a small fraction of the injected light emerges from any given area of the scalp. Light collection is typically improved by optimizing the contact area between the detection system and the skin by means of light guides with large detection surface. Since the form-factor of these light guides do not match the entrance of commercial spectrometers, which are usually equipped with a narrow slit to improve their spectral resolution, broadband NIRS spectrometers are typically custom-built. Nonetheless, off-the-shelf spectrometers have attractive advantages compared to custom-made units, such as low cost, small footprint, and wide availability. We demonstrate that off-the-shelf spectrometers can be easily converted into suitable instruments for deep tissue spectroscopy by improving light collection, while maintaining good spectral resolution, and reducing measurement noise. The ability of this approach to provide reliable cerebral hemodynamics was illustrated in a piglet by measuring CBF and oxygen metabolism under different anesthetic regimens.

  1. Repetitive Transcranial Magnetic Stimulation Changes Cerebral Oxygenation on the Left Dorsolateral Prefrontal Cortex in Bulimia Nervosa: A Near-Infrared Spectroscopy Pilot Study.

    Science.gov (United States)

    Sutoh, Chihiro; Koga, Yasuko; Kimura, Hiroshi; Kanahara, Nobuhisa; Numata, Noriko; Hirano, Yoshiyuki; Matsuzawa, Daisuke; Iyo, Masaomi; Nakazato, Michiko; Shimizu, Eiji

    2016-01-01

    Previous studies showed that food craving in eating disorders can be weakened with high-frequency repetitive transcranial magnetic stimulation (rTMS) on the left dorsolateral prefrontal cortex (DLPFC). The aims of this study were to assess cerebral oxygenation change induced with rTMS and to assess the short-term impact of rTMS on food craving and other bulimic symptoms in patients with bulimia nervosa (BN). Eight women diagnosed with BN according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria participated in this study. We measured haemoglobin concentration changes in the DLPFC with near-infrared spectroscopy during cognitive tasks measuring self-regulatory control in response to food photo stimuli, both at baseline and after a single session of rTMS. Subjective ratings for food cravings demonstrated significant reduction. A significant decrease in cerebral oxygenation of the left DLPFC was also observed after a single session of rTMS. Measurement with NIRS after rTMS intervention may be applicable for discussing the mechanisms underlying rTMS modulation in patients with BN. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

  2. Long-lasting neuronal loss following experimental focal cerebral ischemia is not affected by combined administration of tissue plasminogen activator and hyperbaric oxygen.

    Science.gov (United States)

    Hobohm, Carsten; Laignel, Félix; Kacza, Johannes; Küppers-Tiedt, Lea; Heindl, Marita; Schneider, Dietmar; Grosche, Jens; Härtig, Wolfgang; Michalski, Dominik

    2011-10-12

    Acute focal cerebral ischemia and consecutive energy failure are accompanied by neuronal death in regions with impaired cerebral blood flow. Several translational attempts of potential neuroprotective agents have failed, hence extended perspectives are required regarding the regional differences of neuronal impairment and glial involvement by using clinically relevant stroke models. This study aimed on neuronal loss following experimental focal cerebral ischemia, considering tissue plasminogen activator (tPA) as established treatment in stroke and hyperbaric oxygenation (HBO) as potential neuroprotective co-treatment. Wistar rats were subjected to embolic middle cerebral artery occlusion and underwent either treatment with tPA only, combined tPA+HBO, or no treatment. Neuronal impairment was assessed by Neuronal Nuclei (NeuN) staining in 4 ischemia-related areas and at 4 different time points after stroke induction (24hours, 7, 14 and 28 days). Additionally, spatial relationships between neuronal loss and gliosis were revealed by triple fluorescence staining of neurons, astrocytes and microglia, comparing the ipsi- and contra-lesional hemisphere. Analyzing the ischemic injury in general, a shell-like distribution of neuronal damage was observed, starting in the ischemic core and diminishing over the general ischemic area to the ischemic border zone and the primary non-affected area. This pattern remained detectable up to 4weeks after ischemia induction. Surprisingly, tPA and tPA+HBO did not markedly affect the post-ischemic course of neuronal impairment. Further studies are needed to investigate the effects of treatment with tPA or potential neuroprotective agents on neuronal integrity, with emphasis on the separation of intact neurons from those undergoing apoptosis or necrosis. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Characterization of a novel micro-pressure swirl reactor for removal of chemical oxygen demand and total nitrogen from domestic wastewater at low temperature.

    Science.gov (United States)

    Ren, Qingkai; Yu, Yang; Zhu, Suiyi; Bian, Dejun; Huo, Mingxin; Zhou, Dandan; Huo, Hongliang

    2017-02-06

     A novel micro-pressure swirl reactor (MPSR) was designed and applied to treat domestic wastewater at low temperature by acclimating microbial biomass with steadily decreasing temperature from 15 to 3 °C. Chemical oxygen demand (COD) was constantly removed by 85% and maintained below 50 mg L(-1) in the effluent during the process. When the air flow was controlled at 0.2 m(3) h(-1), a swirl circulation was formed in the reactor, which created a dissolved oxygen (DO) gradient with a low DO zone in the center and a high DO zone in the periphery for denitrification and nitrification. 81% of total nitrogen was removed by this reactor, in which ammonium was reduced by over 90%. However, denitrification was less effective because of the presence of low levels of oxygen. The progressively decreasing temperature favored acclimation of psychrophilic bacteria in the reactor, which replaced mesophilic bacteria in the process of treatment.

  4. Maternal hypoxia decreases capillary supply and increases metabolic inefficiency leading to divergence in myocardial oxygen supply and demand.

    Science.gov (United States)

    Hauton, David; Al-Shammari, Abdullah; Gaffney, Eamonn A; Egginton, Stuart

    2015-01-01

    Maternal hypoxia is associated with a decrease in left ventricular capillary density while cardiac performance is preserved, implying a mismatch between metabolism and diffusive exchange. We hypothesised this requires a switch in substrate metabolism to maximise efficiency of ATP production from limited oxygen availability. Rat pups from pregnant females exposed to hypoxia (FIO2=0.12) at days 10-20 of pregnancy were grown to adulthood and working hearts perfused ex vivo. 14C-labelled glucose and 3H-palmitate were provided as substrates and metabolism quantified from recovery of 14CO2 and 3H2O, respectively. Hearts of male offspring subjected to Maternal Hypoxia showed a 20% decrease in cardiac output (P<0.05), despite recording a 2-fold increase in glucose oxidation (P<0.01) and 2.5-fold increase (P<0.01) in palmitate oxidation. Addition of insulin to Maternal Hypoxic hearts, further increased glucose oxidation (P<0.01) and suppressed palmitate oxidation (P<0.05), suggesting preservation in insulin signalling in the heart. In vitro enzyme activity measurements showed that Maternal Hypoxia increased both total and the active component of cardiac pyruvate dehydrogenase (both P<0.01), although pyruvate dehydrogenase sensitivity to insulin was lost (NS), while citrate synthase activity declined by 30% (P<0.001) and acetyl-CoA carboxylase activity was unchanged by Maternal Hypoxia, indicating realignment of the metabolic machinery to optimise oxygen utilisation. Capillary density was quantified and oxygen diffusion characteristics examined, with calculated capillary domain area increased by 30% (P<0.001). Calculated metabolic efficiency decreased 4-fold (P<0.01) for Maternal Hypoxia hearts. Paradoxically, the decline in citrate synthase activity and increased metabolism suggest that the scope of individual mitochondria had declined, rendering the myocardium potentially more sensitive to metabolic stress. However, decreasing citrate synthase may be essential to preserve

  5. Maternal hypoxia decreases capillary supply and increases metabolic inefficiency leading to divergence in myocardial oxygen supply and demand.

    Directory of Open Access Journals (Sweden)

    David Hauton

    Full Text Available Maternal hypoxia is associated with a decrease in left ventricular capillary density while cardiac performance is preserved, implying a mismatch between metabolism and diffusive exchange. We hypothesised this requires a switch in substrate metabolism to maximise efficiency of ATP production from limited oxygen availability. Rat pups from pregnant females exposed to hypoxia (FIO2=0.12 at days 10-20 of pregnancy were grown to adulthood and working hearts perfused ex vivo. 14C-labelled glucose and 3H-palmitate were provided as substrates and metabolism quantified from recovery of 14CO2 and 3H2O, respectively. Hearts of male offspring subjected to Maternal Hypoxia showed a 20% decrease in cardiac output (P<0.05, despite recording a 2-fold increase in glucose oxidation (P<0.01 and 2.5-fold increase (P<0.01 in palmitate oxidation. Addition of insulin to Maternal Hypoxic hearts, further increased glucose oxidation (P<0.01 and suppressed palmitate oxidation (P<0.05, suggesting preservation in insulin signalling in the heart. In vitro enzyme activity measurements showed that Maternal Hypoxia increased both total and the active component of cardiac pyruvate dehydrogenase (both P<0.01, although pyruvate dehydrogenase sensitivity to insulin was lost (NS, while citrate synthase activity declined by 30% (P<0.001 and acetyl-CoA carboxylase activity was unchanged by Maternal Hypoxia, indicating realignment of the metabolic machinery to optimise oxygen utilisation. Capillary density was quantified and oxygen diffusion characteristics examined, with calculated capillary domain area increased by 30% (P<0.001. Calculated metabolic efficiency decreased 4-fold (P<0.01 for Maternal Hypoxia hearts. Paradoxically, the decline in citrate synthase activity and increased metabolism suggest that the scope of individual mitochondria had declined, rendering the myocardium potentially more sensitive to metabolic stress. However, decreasing citrate synthase may be essential to

  6. Gill morphometrics of the thresher sharks (Genus Alopias): Correlation of gill dimensions with aerobic demand and environmental oxygen.

    Science.gov (United States)

    Wootton, Thomas P; Sepulveda, Chugey A; Wegner, Nicholas C

    2015-05-01

    Gill morphometrics of the three thresher shark species (genus Alopias) were determined to examine how metabolism and habitat correlate with respiratory specialization for increased gas exchange. Thresher sharks have large gill surface areas, short water-blood barrier distances, and thin lamellae. Their large gill areas are derived from long total filament lengths and large lamellae, a morphometric configuration documented for other active elasmobranchs (i.e., lamnid sharks, Lamnidae) that augments respiratory surface area while limiting increases in branchial resistance to ventilatory flow. The bigeye thresher, Alopias superciliosus, which can experience prolonged exposure to hypoxia during diel vertical migrations, has the largest gill surface area documented for any elasmobranch species studied to date. The pelagic thresher shark, A. pelagicus, a warm-water epi-pelagic species, has a gill surface area comparable to that of the common thresher shark, A. vulpinus, despite the latter's expected higher aerobic requirements associated with regional endothermy. In addition, A. vulpinus has a significantly longer water-blood barrier distance than A. pelagicus and A. superciliosus, which likely reflects its cold, well-oxygenated habitat relative to the two other Alopias species. In fast-swimming fishes (such as A. vulpinus and A. pelagicus) cranial streamlining may impose morphological constraints on gill size. However, such constraints may be relaxed in hypoxia-dwelling species (such as A. superciliosus) that are likely less dependent on streamlining and can therefore accommodate larger branchial chambers and gills.

  7. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G

    2014-01-01

    cerebral artery velocity (MCA Vmean), arterial-venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38......Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle...... venous noradrenaline, and falling arterial carbon dioxide tension (P aCO 2) (R(2) ≥ 0.41, P ≤ 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing P aCO 2 and enhancing vasoconstrictor activity. However...

  8. The Metropolis-Hastings algorithm, a handy tool for the practice of environmental model estimation : illustration with biochemical oxygen demand data

    Directory of Open Access Journals (Sweden)

    Franck Torre

    2001-02-01

    Full Text Available Environmental scientists often face situations where: (i stimulus-response relationships are non-linear; (ii data are rare or imprecise; (iii facts are uncertain and stimulus-responses relationships are questionable. In this paper, we focus on the first two points. A powerful and easy-to-use statistical method, the Metropolis-Hastings algorithm, allows the quantification of the uncertainty attached to any model response. This stochastic simulation technique is able to reproduce the statistical joint distribution of the whole parameter set of any model. The Metropolis-Hastings algorithm is described and illustrated on a typical environmental model: the biochemical oxygen demand (BOD. The aim is to provide a helpful guideline for further, and ultimately more complex, models. As a first illustration, the MH-method is also applied to a simple regression example to demonstrate to the practitioner the ability of the algorithm to produce valid results.

  9. Removal of color and chemical oxygen demand using a coupled coagulation-electrocoagulation-ozone treatment of industrial wastewater that contains offset printing dyes

    Energy Technology Data Exchange (ETDEWEB)

    Roa M, G.; Barrera D, C.; Balderas H, P.; Zaldumbide O, F. [Centro Conjunto de Investigacion en Quimica Sustentable UAEM-UNAM, Km 14.5 Carretera Toluca-Atlacomulco, 50200 San Cayetano-Toluca, Estado de Mexico (Mexico); Reyes P, H. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon y Paseo Tollocan s/n, 50120 Toluca, Estado de Mexico (Mexico); Bilyeu, B., E-mail: groam@uaemex.mx [Xavier University of Louisiana, Department of Chemistry, 1 Drexel Drive, New Orleans, LA 70125 (United States)

    2014-07-01

    Industrial offset printing processes generate wastewater with highly colored obtaining values of 5 x 10{sup 6}Pt-Co units and great values of chemical oxygen demand (COD) 5.3 x 10{sup -5} mg L{sup -1}. Thus, conventional technologies such as biologicals treatment fail in reaching the discharge limits. In this research, a sequential treatment was applied: coagulation with aluminum hydroxychloride (AHC), electrocoagulation with Al anodes and finally ozonation. Optimal conditions are found when adding 20 mg L{sup -1} AHC, followed by electrocoagulation at 4 A for 50 min, and finally alkaline ozonation for 15 min, resulting in an overall color removal of 99.99% color and 99.35 COD. The sludge generated by the coagulation process was analyzed by scanning electron microscopy and energy dispersive X-ray (EDX) microanalysis. (Author)

  10. Chemical oxygen demand removal efficiency and limited factors study of aminosilicone polymers in a water emulsion by iron-carbon micro-electrolysis.

    Science.gov (United States)

    Yang, Shangyuan; Liang, Zhiwei; Yu, Huadong; Wang, Yunlong; Chen, Yingxu

    2014-02-01

    Micro-electrolysis was applied in the present study to investigate the effect of pH, iron-carbon mass ratio, contact time, and treatment batch on the removal efficiency of chemical oxygen demand (COD) within an aminosilicone emulsion. The results exhibited that the removal efficiency of COD decreased linearly with the batch increase, and this tendency was consistent under the various conditions. The adsorption of activated carbons contributes a large portion to the elimination of COD within the aminosilicone emulsion. The oxidation action of iron-carbon micro-electrolysis was proven and the aminosilicone emulsion's COD removal contribution was approximately 16%. Aminosilicone polymers were adsorbed on the surface of activated carbons and iron chips, which contributes to the decline of COD removal efficiency and limits the contribution of oxidation action.

  11. Combined coagulation-flocculation and sequencing batch reactor with phosphorus adjustment for the treatment of high-strength landfill leachate: experimental kinetics and chemical oxygen demand fractionation.

    Science.gov (United States)

    El-Fadel, M; Matar, F; Hashisho, J

    2013-05-01

    The treatability of high-strength landfill leachate is challenging and relatively limited. This study examines the feasibility of treating high-strength landfill leachate (chemical oxygen demand [COD]: 7,760-11,770 mg/L, biochemical oxygen demand [BOD5]: 2,760-3,569 mg/L, total nitrogen [TN] = 980-1,160 mg/L) using a sequencing batch reactor (SBR) preceded by a coagulation-flocculation process with phosphorus nutritional balance under various mixing and aeration patterns. Simulations were also conducted to define kinetic parameters and COD fractionation. Removal efficiencies reached 89% for BOD5, 60% for COD, and 72% for TN, similar to and better than reported studies, albeit with a relatively lower hydraulic retention time (HRT) and solid retention time (SRT). The coupled experimental and simulation results contribute in filling a gap toward managing high-strength landfill leachate and providing guidelines for corresponding SBR applications. The treatability of high-strength landfill leachate, which is challenging and relatively limited, was demonstrated using a combined coagulation-flocculation with SBR technology and nutrient balance adjustment. The most suitable coagulant, kinetic design parameters, and COD fractionation were defined using coupled experimental and simulation results contributing in filling a gap toward managing high-strength leachate by providing guidelines for corresponding SBR applications and anticipating potential constraints related to the non-biodegradable COD fraction. In this context, while the combined coagulation-flocculation and SBR process improved removal efficiencies, posttreatment may be required for high-strength leachate, depending on discharge standards and ultimate usage of the treated leachate.

  12. The effects of anticholinergic drugs on regional cerebral blood flow, and oxygen metabolism in previously untreated patients with Parkinson`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Satoko; Takahashi, Satoshi; Yonezawa, Hisashi; Sato, Yoshitomo [Iwate Medical Univ., Morioka (Japan). School of Medicine

    1998-12-01

    Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO{sub 2}) were measured using the steady-state {sup 15}O technique and positron emission tomography (PET) in six previously untreated patients with Parkinson`s disease before and after trihexyphenidyl (THP) treatment. The patients comprised of 4 men and 2 women with Hoehn-Yahr stage II-III. Their ages at the onset of the study ranged from 46 to 57 years (mean{+-}SD, 51.8{+-}3.7) and the duration of the illness ranged from 10 to 48 months (mean{+-}SD, 28.8{+-}15.5). The PET study, assessments of the disability and cognitive function were undergone twice. The first time assessments were done was when the patients were not receiving any drugs, and the second time was one to three months after administration of 6 mg THP. All patients showed clinical improvement after THP treatment. The mean disability score of Unified Parkinson`s Disease Rating Scale decreased from 35.1 (SD{+-}11.3) to 25.7 (SD{+-}11.6). The cognitive function assessed by Hasegawa`s dementia rating scale-revised, Mini-Mental State Examination, Wechsler Adult Intelligence Scale-Revised, and Wechsler Memory Scale-Revised, were not significantly different before and after the THP treatment. After the THP treatment, rCBF and rCMRO{sub 2} decreased significantly in the striatum (about 15%) and all cerebral cortices (about 10%) on both sides contralateral and ipsilateral to the predominantly symptomatic limbs. We conclude that an anticholinergic THP decreases the rCBF and rCMRO{sub 2} significantly in the cerebral cortices without cognitive impairment in early untreated patients with Parkinson`s disease. (author)

  13. Effects of chemical oxygen demand (COD)/N ratios on pollutants removal in the subsurface wastewater infiltration systems with/without intermittent aeration.

    Science.gov (United States)

    Song, Siyu; Pan, Jing; Wu, Shiwei; Guo, Yijing; Yu, Jingxiao; Shan, Qingchi

    2016-01-01

    The matrix oxidation reduction potential level, organic pollutants and nitrogen removal performances of eight subsurface wastewater infiltration systems (SWISs) (four with intermittent aeration, four without intermittent aeration) fed with influent chemical oxygen demand (COD)/N ratio of 3, 6, 12 and 18 were investigated. Nitrification of non-aerated SWISs was poor due to oxygen deficiency while higher COD/N ratios further led to lower COD and nitrogen removal rate. Intermittent aeration achieved almost complete nitrification, which successfully created aerobic conditions in the depth of 50 cm and did not change anoxic or anaerobic conditions in the depth of 80 and 110 cm. The sufficient carbon source in high COD/N ratio influent greatly promoted denitrification in SWISs with intermittent aeration. High average removal rates of COD (95.68%), ammonia nitrogen (NH4(+)-N) (99.32%) and total nitrogen (TN) (89.65%) were obtained with influent COD/N ratio of 12 in aerated SWISs. The results suggest that intermittent aeration was a reliable option to achieve high nitrogen removal in SWISs, especially with high COD/N ratio wastewater.

  14. Improvement of oxygen supply by an artificial carrier in combination with normobaric oxygenation decreases the volume of tissue hypoxia and tissue damage from transient focal cerebral ischemia

    NARCIS (Netherlands)

    Seiffge, David J.; Lapina, Natalia E.; Tsagogiorgas, Charalambos; Theisinger, Bastian; Henning, Robert H.; Schilling, Lothar

    2012-01-01

    Tissue hypoxia may play an important role in the development of ischemic brain damage. In the present study we investigated in a rat model of transient focal brain ischemia the neuroprotective effects of increasing the blood oxygen transport capacity by applying a semifluorinated alkane (SFA)-contai

  15. Near-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair: relation to end-tidal CO2 tension.

    Science.gov (United States)

    Sørensen, H; Nielsen, H B; Secher, N H

    2016-08-01

    During open abdominal aortic aneurism (AAA) repair cerebral blood flow is challenged. Clamping of the aorta may lead to unintended hyperventilation as metabolism is reduced by perfusion of a smaller part of the body and reperfusion of the aorta releases vasodilatory substances including CO2. We intend to adjust ventilation according end-tidal CO2 tension (EtCO2) and here evaluated to what extent that strategy maintains frontal lobe oxygenation (ScO2) as determined by near infrared spectroscopy. For 44 patients [5 women, aged 70 (48-83) years] ScO2, mean arterial pressure (MAP), EtCO2, and ventilation were obtained retrospectively from the anesthetic charts. By clamping the aorta, ScO2 and EtCO2 were kept stable by reducing ventilation (median, -0.8 l min(-1); interquartile range, -1.1 to -0.4; P body is reperfused.

  16. The significance of changes in cerebral oxygen and glucose metabolism in patients with cerebral hemorrhage caused by acute hypertension%急性高血压脑出血患者脑糖氧代谢变化及意义

    Institute of Scientific and Technical Information of China (English)

    马骏; 陈锷峰; 屠传建; 钱辉; 骆明; 顾志伟; 张建民

    2014-01-01

    Objective To study the clinical significance of early changes in cerebral oxygen and glucose metabolism in patients with cerebral hemorrhage and with Glasgow coma score (GCS) of 5-8 caused by acute hypertension in order to find relationship between those changes and prognosis.Methods From January 1,2011 to June 30,2012,a cohort of 43 patients with cerebral hemorrhage caused by acute hypertension were enrolled for retrospective study.Radial artery and internal jugular vein were separately cannulated retrogradely for collecting blood for blood gas analysis and blood glucose tests carried out 24 hours after the onset of the cerebral hemorrhage and then every 6-8 hours and as any major changes in physical signs of patients occurred.And this monitoring kept for consecutive 3 days.The data of these laboratory findings were analyzed and calculated to determine internal jugular vein oxygen saturation (SjVO2),cerebral oxygen utilization rate (CEO2),cerebral arterio-venous oxygen difference (AVDO2),arterio-venous blood glucose difference (V-Aglu),arterio-venous lactic acid difference (V-Alac) and absolute value of carbon dioxide pressure difference between jugular vein and artery (V-APCO2).All patients met the diagnostic criteria of hypertensive cerebral hemorrhage revised by the 4th National Academic Conference on cerebrovascular disease in 1995 requiring diagnosis confirmed by brain CT,admitted within 24 hours of onset,Glasgow coma score (GCS) 5-8 and a history of hypertension.Exclusion criteria were:cerebral hemorrhage caused by traumatic intracranial hematoma,spontaneous subarachnoid hemorrhage,arteriovenous malformation and Moyamoya disease,intracranial tumor apoplexy,cerebral bleeding derived from the disturbance of blood coagulation system,and cerebral hemorrhagic infarction.According to the short-term prognosis,the patients were divided into the death group and the survival group.Then the differences in biomarkers mentioned above between two groups were compared to

  17. High glucose-induced mitochondrial respiration and reactive oxygen species in mouse cerebral pericytes is reversed by pharmacological inhibition of mitochondrial carbonic anhydrases: Implications for cerebral microvascular disease in diabetes.

    Science.gov (United States)

    Shah, Gul N; Morofuji, Yoichi; Banks, William A; Price, Tulin O

    2013-10-18

    Hyperglycemia-induced oxidative stress leads to diabetes-associated damage to the microvasculature of the brain. Pericytes in close proximity to endothelial cells in the brain microvessels are vital to the integrity of the blood-brain barrier and are especially susceptible to oxidative stress. According to our recently published results, streptozotocin-diabetic mouse brain exhibits oxidative stress and loose pericytes by twelve weeks of diabetes, and cerebral pericytes cultured in high glucose media suffer intracellular oxidative stress and apoptosis. Oxidative stress in diabetes is hypothesized to be caused by reactive oxygen species (ROS) produced during hyperglycemia-induced enhanced oxidative metabolism of glucose (respiration). To test this hypothesis, we investigated the effect of high glucose on respiration rate and ROS production in mouse cerebral pericytes. Previously, we showed that pharmacological inhibition of mitochondrial carbonic anhydrases protects the brain from oxidative stress and pericyte loss. The high glucose-induced intracellular oxidative stress and apoptosis of pericytes in culture were also reversed by inhibition of mitochondrial carbonic anhydrases. Therefore, we extended our current study to determine the effect of these inhibitors on high glucose-induced increases in pericyte respiration and ROS. We now report that both the respiration and ROS are significantly increased in pericytes challenged with high glucose. Furthermore, inhibition of mitochondrial carbonic anhydrases significantly slowed down both the rate of respiration and ROS production. These data provide new evidence that pharmacological inhibitors of mitochondrial carbonic anhydrases, already in clinical use, may prove beneficial in protecting the brain from oxidative stress caused by ROS produced as a consequence of hyperglycemia-induced enhanced respiration. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Downstream signaling of reactive oxygen species, protein kinase C epsilon translocation and delayed neuroprotection in sevoflurane preconditioned rats following cerebral ischemia/reperfusion

    Institute of Scientific and Technical Information of China (English)

    Zhi Ye; Qulian Guo; E Wang; Yundan Pan; Qing Li; Honghao Zhou

    2009-01-01

    BACKGROUND: Brief exposure to the anesthetic sevoflurane results in delayed neuroprotection.However, few studies have addressed delayed neuroprotection after preconditioning with a single administration of sevoflurane.OBJECTIVE: To explore the relationship between a single preconditioning administration of sevoflurane and reactive oxygen species production and protein kinase C-epsilon (PKC- ε ) translocation.DESIGN, TIME, AND SETTING: The randomized, controlled, animal experiment was conducted at the Central Laboratory, Xiangya Hospital, Central South University, China from November 2007 to April 2008.MATERIALS: A total of 120 healthy, male, Sprague Dawley rats were equally and randomly assigned into five groups: sham operation, ischemia/reperfusion, sevoflurane, 2-mercaptopropionylglycine (2-MPG, a selective reactive oxygen species scavenger) + sevoflurane (MPG + sevoflurane), and MPG. Sevoflurane (Baxter, USA) and MPG (Sigma, USA) were used in this study.METHODS: Intervention consisted of three procedures. (1) MPG injection: a selective reactive oxygen species scavenger, MPG (20 mg/kg), was infused into the rat caudal vein in the MPG and MPG + sevoflurane groups. (2) Sevoflurane preconditioning: 30 minutes following MPG injection,rats in the sevoflurane and MPG + sevoflurane groups breathed a mixed gas of 2.4% sevoflurane and 97.6% oxygen for 60 minutes. Rats in the sham operation, ischemia/reperfusion, and MPG groups breathed 100% pure oxygen for 60 minutes. (3) Ischemia/reperfusion: 24 hours after sevoflurane or pure oxygen preconditioning, middle cerebral artery occlusion models were established in the ischemia/reperfusion, sevoflurane, MPG + sevoflurane, and MPG groups.Following 2 hours ischemia/6 hours and 24 hours reperfusion, the carotid artery was separated, but the middle cerebral artery was not occluded, in the sham operation group.MAIN OUTCOME MEASURES: In the ischemic hemisphere, PKC-ε translocation in the rat parietal cortex was measured by Western

  19. Achieving low effluent NO3-N and TN concentrations in low influent chemical oxygen demand (COD) to total Kjeldahl nitrogen (TKN) ratio without using external carbon source

    Science.gov (United States)

    Cao, Jiashun; Oleyiblo, Oloche James; Xue, Zhaoxia; Otache, Y. Martins; Feng, Qian

    2015-07-01

    Two mathematical models were used to optimize the performance of a full-scale biological nutrient removal (BNR) activated treatment plant, a plug-flow bioreactors operated in a 3-stage phoredox process configuration, anaerobic anoxic oxic (A2/O). The ASM2d implemented on the platform of WEST2011 software and the BioWin activated sludge/anaerobic digestion (AS/AD) models were used in this study with the aim of consistently achieving the designed effluent criteria at a low operational cost. Four ASM2d parameters (the reduction factor for denitrification , the maximum growth rate of heterotrophs (µH), the rate constant for stored polyphosphates in PAOs ( q pp), and the hydrolysis rate constant ( k h)) were adjusted. Whereas three BioWin parameters (aerobic decay rate ( b H), heterotrophic dissolved oxygen (DO) half saturation ( K OA), and Y P/acetic) were adjusted. Calibration of the two models was successful; both models have average relative deviations (ARD) less than 10% for all the output variables. Low effluent concentrations of nitrate nitrogen (N-NO3), total nitrogen (TN), and total phosphorus (TP) were achieved in a full-scale BNR treatment plant having low influent chemical oxygen demand (COD) to total Kjeldahl nitrogen (TKN) ratio (COD/TKN). The effluent total nitrogen and nitrate nitrogen concentrations were improved by 50% and energy consumption was reduced by approximately 25%, which was accomplished by converting the two-pass aerobic compartment of the plug-flow bioreactor to anoxic reactors and being operated in an alternating mode. Findings in this work are helpful in improving the operation of wastewater treatment plant while eliminating the cost of external carbon source and reducing energy consumption.

  20. Cortical spreading depression impairs oxygen delivery and metabolism in mice.

    Science.gov (United States)

    Yuzawa, Izumi; Sakadžić, Sava; Srinivasan, Vivek J; Shin, Hwa Kyoung; Eikermann-Haerter, Katharina; Boas, David A; Ayata, Cenk

    2012-02-01

    Cortical spreading depression (CSD) is associated with severe hypoperfusion in mice. Using minimally invasive multimodal optical imaging, we show that severe flow reductions during and after spreading depression are associated with a steep decline in cerebral metabolic rate of oxygen. Concurrent severe hemoglobin desaturation suggests that the oxygen metabolism becomes at least in part supply limited, and the decrease in cortical blood volume implicates vasoconstriction as the mechanism. In support of oxygen supply-demand mismatch, cortical nicotinamide adenine dinucleotide (NADH) fluorescence increases during spreading depression for at least 5 minutes, particularly away from parenchymal arterioles. However, modeling of tissue oxygen delivery shows that cerebral metabolic rate of oxygen drops more than predicted by a purely supply-limited model, raising the possibility of a concurrent reduction in oxygen demand during spreading depression. Importantly, a subsequent spreading depression triggered within 15 minutes evokes a monophasic flow increase superimposed on the oligemic baseline, which markedly differs from the response to the preceding spreading depression triggered in naive cortex. Altogether, these data suggest that CSD is associated with long-lasting oxygen supply-demand mismatch linked to severe vasoconstriction in mice.

  1. Development of A Novel Methode for COD (Chemical Oxygen Demand Measurement based onPhotoelectrochemical Cell: Characterization of TiO2/ITO Film Working Electrode

    Directory of Open Access Journals (Sweden)

    Y.K. Krisnandi

    2009-04-01

    Full Text Available Nanosize TiO2 film,immobilized on an ITO (Indium Tin Oxide glass, was successfully fabricated. The film was prepared by a dip coatingtechnique in a hydrothermal sol-gel system and subjected to a heat treatment at 100°C up to 450°C. Characterization ofthe film by XRD, AFM, BET methods revealed the occurrence of anatase form and 9.64 nm in crystallite size; havingthree dimensional profile and roughness with height of typically 9.8 nm; and surface area of 58.21 m2/g. The film thenwas employed as a working electrode in a photo electrochemical system (PES. This PES generated a photocurrent thatproportional to the organic chemical concentration in the water sample. Integration of the photocurrent versus timegives a charge (Q that represent the event of complete mineralization of organic chemical in the TiO2 surface and canbe correlated to the Chemical Oxygen Demand (COD of measured water. This system has a potential to be developedfor a novel COD sensor.

  2. Chemical oxygen demand, total organic carbon and colour reduction in slaughterhouse wastewater by unmodified and iron-modified clinoptilolite-rich tuff.

    Science.gov (United States)

    Torres-Pérez, J; Solache-Ríos, M; Martínez-Miranda, V

    2014-01-01

    In this study, reduction of chemical oxygen demand (COD), colour, and total organic carbon in effluents from a slaughterhouse in central Mexico was performed using clinoptilolite-rich tuff. The experimental parameters considered were initial concentration of the adsorbate, pH, adsorbent dosage, and contact time. Surface morphology of the materials was tested by using scanning electron microscopy. Specific surface area was analysed by using Brunauer-Emmett-Teller (BET) and phase composition was analysed by using X-ray diffraction. The experimental adsorption data were fitted to the first- and pseudo-second-order kinetic models. The highest COD removal was observed in slightly acidic pH conditions. The maximum reduction efficiency of COD was accomplished with unmodified clinoptilolite-rich tuff at a contact time of 1440 min. In these conditions, the adsorbent was efficient for treating wastewater from a slaughterhouse. Moreover, after several regeneration cycles with Fenton reagent or hydrogen peroxide, the regenerated zeolite with H2O2 (3%) showed the best reduction efficiencies.

  3. Simultaneous efficient removal of high-strength ammonia nitrogen and chemical oxygen demand from landfill leachate by using an extremely high ammonia nitrogen-resistant strain.

    Science.gov (United States)

    Yu, Dahai; Yang, Jiyu; Fang, Xuexun; Ren, Hejun

    2015-01-01

    Bioaugmentation is a promising technology for pollutant elimination from stressed environments, and it would provide an efficient way to solve challenges in traditional biotreatment of wastewater with high strength of ammonia nitrogen (NH4(+)-N). A high NH4(+)-N-resistant bacteria strain, identified as Bacillus cereus (Jlu BC), was domesticated and isolated from the bacteria consortium in landfill leachate. Jlu BC could survive in 100 g/L NH4(+)-N environment, which indicated its extremely high NH4(+)-N tolerance than the stains found before. Jlu BC was employed in the bioaugmented system to remove high strength of NH4(+)-N from landfill leachate, and to increase the removal efficiency, response surface methodology (RSM) was used for optimizing bioaugmentation degradation conditions. At the optimum condition (initial pH 7.33, 4.14 days, initial chemical oxygen demand [COD] concentration [18,000 mg/L], 3.5 mL inoculated domesticated bacteria strain, 0.3 mg/mL phosphorus supplement, 30 °C, and 170 rpm), 94.74 ± 3.8% removal rate of NH4(+)-N was obtained, and the experiment data corresponded well with the predicted removal rate of the RSM models (95.50%). Furthermore, COD removal rate of 81.94 ± 1.4% was obtained simultaneously. The results presented are promising, and the screened strain would be of great practical importance in mature landfill leachate and other NH4(+)-N enrichment wastewater pollution control.

  4. Enhanced removal of chemical oxygen demand, nitrogen and phosphorus using the ameliorative anoxic/anaerobic/oxic process and micro-electrolysis.

    Science.gov (United States)

    Bao, K Q; Gao, J Q; Wang, Z B; Zhang, R Q; Zhang, Z Y; Sugiura, N

    2012-01-01

    Synthetic wastewater was treated using a novel system integrating the reversed anoxic/anaerobic/oxic (RAAO) process, a micro-electrolysis (ME) bed and complex biological media. The system showed superior chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) removal rates. Performance of the system was optimised by considering the influences of three major controlling factors, namely, hydraulic retention time (HRT), organic loading rate (OLR) and mixed liquor recirculation (MLR). TP removal efficiencies were 69, 87, 87 and 83% under the HRTs of 4, 8, 12 and 16 h. In contrast, HRT had negligible effects on the COD and TN removal efficiencies. COD, TN and TP removal efficiencies from synthetic wastewater were 95, 63 and 87%, respectively, at an OLR of 1.9 g/(L·d). The concentrations of COD, TN and TP in the effluent were less than 50, 15 and 1 mg/L, respectively, at the controlled MLR range of 75-100%. In this system, organics, TN and TP were primarily removed from anoxic tank regardless of the operational conditions.

  5. Accuracy of different sensors for the estimation of pollutant concentrations (total suspended solids, total and dissolved chemical oxygen demand) in wastewater and stormwater.

    Science.gov (United States)

    Lepot, Mathieu; Aubin, Jean-Baptiste; Bertrand-Krajewski, Jean-Luc

    2013-01-01

    Many field investigations have used continuous sensors (turbidimeters and/or ultraviolet (UV)-visible spectrophotometers) to estimate with a short time step pollutant concentrations in sewer systems. Few, if any, publications compare the performance of various sensors for the same set of samples. Different surrogate sensors (turbidity sensors, UV-visible spectrophotometer, pH meter, conductivity meter and microwave sensor) were tested to link concentrations of total suspended solids (TSS), total and dissolved chemical oxygen demand (COD), and sensors' outputs. In the combined sewer at the inlet of a wastewater treatment plant, 94 samples were collected during dry weather, 44 samples were collected during wet weather, and 165 samples were collected under both dry and wet weather conditions. From these samples, triplicate standard laboratory analyses were performed and corresponding sensors outputs were recorded. Two outlier detection methods were developed, based, respectively, on the Mahalanobis and Euclidean distances. Several hundred regression models were tested, and the best ones (according to the root mean square error criterion) are presented in order of decreasing performance. No sensor appears as the best one for all three investigated pollutants.

  6. Performance of a stratified sand filter in removal of chemical oxygen demand, total suspended solids and ammonia nitrogen from high-strength wastewaters.

    Science.gov (United States)

    Healy, M G; Rodgers, M; Mulqueen, J

    2007-06-01

    A stratified sand filter column, operated in recirculation mode and treating synthetic effluent resembling high-strength dairy wastewaters was studied over a 342-d duration. The aim of this paper was to examine the organic, total suspended solids (TSS) and nutrient removal rates of the sand filter, operated in recirculation mode, under incrementally increasing hydraulic and organic loading rates and to propose a field filter-sizing criterion. Best performance was obtained at a system hydraulic loading rate of 10 L m(-2) d(-1); a higher system hydraulic loading rate (of 13.4 L m(-2) d(-1)) caused surface ponding. The system hydraulic loading rate of 10 L m(-2) d(-1) gave a filter chemical oxygen demand (COD), TSS, and total kjeldahl nitrogen (TKN) loading rate of 14, 3.7, and 2.1 g m(-2) d(-1), respectively, and produced consistent COD and TSS removals of greater than 99%, and an effluent NO(3)-N concentration of 42 mg L(-1) (accounting for an 86% reduction in total nitrogen (Tot-N)). As the proportional surface area requirement for the sand filter described in this study is less than the recommended surface area requirement of a free-water surface (FWS) wetland treating an effluent of similar quality, it could provide an economic and sustainable alternative to conventional wetland treatment.

  7. Assessment of a modified and optimised method for determining chemical oxygen demand of solid substrates and solutions with high suspended solid content.

    Science.gov (United States)

    Raposo, F; de la Rubia, M A; Borja, R; Alaiz, M

    2008-07-15

    A modified approach to determine the chemical oxygen demand (COD) of solid substrates based on the DIN 38414-S9 standard method is proposed. The adapted procedure is assessed and compared with standard methods widely used for water and wastewater such as the American Public Health Association-American Water Works Association-Water Pollution Control Federation (APHA-AWWA-WPCF) standard methods 5220 B-open reflux (SM-OR) and 5220 D-closed reflux colorimetric (SM-CR). Solutions with high suspended concentration of solids, as well as digestates from an anaerobic reactor, were used during the comparative test. For solid substrates, the COD recovery was about 100% when the proposed method was used. For solutions with solid content higher than 20 g TS L(-1), the recovery was only completed when the proposed method was used, showing that the methods traditionally employed are not very appropriate for samples with the described characteristics. For instance, percentages of COD recovery in the ranges of 77.3-87.1% and 89.4-94.1% were achieved when the SM-OR and SM-CR methods were used, respectively.

  8. Blood-Oxygenation-Level-Dependent-(BOLD- Based R2′ MRI Study in Monkey Model of Reversible Middle Cerebral Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2011-01-01

    Full Text Available Objective. To investigate the value of BOLD-based reversible transverse relaxation rate (R2′ MRI in detecting ischemic penumbra (IP in a monkey model of reversible middle cerebral artery occlusion (MCAO and time evolution of relative R2′ (rR2′ in infarcted core, IP, and oligemia. Materials and Methods. 6 monkeys were used to make MCAO by the microcatheter method. MR scans were performed at 0 h (1 h after MCAO, 1 h, 3 h, 6 h, 12 h, 24 h, and 48 h after reperfusion. R2′ was calculated using quantitative T2 and T2∗ maps. Ischemic area was subdivided into infracted core, IP and oligemia. rR2′ was calculated respectively. Results. Reversible MCAO model for 4/6 monkeys was made successfully. rR2′ values were significantly different at each time point, being highest in oligemia followed by IP and infarcted core (<.05. With reperfusion time evolution, rR2′ in infarcted core showed a decreased trend: sharply decreased within 6 hours and maintained at 0 during 6–48 hours (<.05. rR2′ values in IP and oligemia showed similar increased trend: sharply increased within 6 hours, maintained a plateau during 6–24 hours, and slightly increased until 48 hours. Conclusion. BOLD-based R2′ MRI can be used to describe changes of cerebral oxygen extract in acute ischemic stroke, and it can provide additional information in detecting IP. The time evolution rR2′ in infarcted core, IP, and oligemia is in accordance with the underlying pathophysiology.

  9. Changes in serum cellular adhesion molecule and matrix metalloproteinase-9 levels in patients with cerebral infarction following hyperbaric oxygen therapy A case and intergroup control study

    Institute of Scientific and Technical Information of China (English)

    Renliang Zhao; Chunxia Wang; Yongjun Wang

    2008-01-01

    BACKGROUND: Animal studies have confirmed that hyperbaric oxygen (HBO) therapy can reduce matrix metalloproteinase activity and blood brain barrier permeability, thereby exhibiting neuroprotective effects. However, at present, consensus does not exist in terms of its clinical efficacy. OBJECTIVE: To validate the significance of changes in serum cellular adhesion molecule and MMP-9 levels in patients with cerebral infarction following HBO therapy. DESIGN, TIME AND SETTING: This randomized, controlled, neurobiochemical study was performed at the Department of Neurology, Affiliated Hospital of Qingdao University Medical College between December 2002 and March 2006. PARTICIPANTS: A total of 112 patients with acute cerebral infarction of internal carotid artery, comprising 64 males and 48 females, averaging (67 ± 11) years, were recruited and randomized to a HBO group (n = 50) and a routine treatment group (n = 62). An additional 30 gender- and age-matched normal subjects, consisting of 17 males and 13 females, averaging (63 ± 9) years, were enrolled as control subjects. METHODS: The routine treatment group received routine drug treatment and rehabilitation exercise. HBO treatment was additionally performed in the HBO group, once a day, for a total of 10 days. MAIN OUTCOME MEASURES: Serum levels of soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, soluble E-selectin, and matrix metalloproteinase-9 were detected by enzyme linked immunosorbent assay. RESULTS: Upon admission, serum levels of soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, soluble E-selectin, and matrix metalloproteinase-9 were significantly increased in patients with cerebral infarction, compared with control subjects (P < 0.01). Following HBO and routine treatments, serum levels of the above-mentioned indices were significantly reduced in the HBO and routine treatment groups (P < 0.01). Moreover, greater efficacy was observed in the HBO

  10. Variations of brain edema and neurological function of rat models of cerebral infarction after hyperbaric oxygen therapy%高压氧干预脑梗死模型大鼠脑水肿及神经功能变化

    Institute of Scientific and Technical Information of China (English)

    田烜

    2015-01-01

    sweling in rats after middle cerebral artery occlusion, and discuss the possible mechanism of action underlying the neuroprotective effects of hyperbaric oxygen therapy in rats with cerebral infraction. METHODS:Sixty adult female rat models of cerebral infarction were successfuly established by middle cerebral artery occlusion using suture method and then randomly divided into the sham, cerebral infarction and hyperbaric oxygen therapy groups (n=20 rats/group). At 3 days after middle cerebral artery occlusion, apoptosis of nerve cels in the infract area of rats in each group was detected by TUNEL method. At 72 hours after middle cerebral artery occlusion, the gene transcription and protein expression of aquaporin 4/9 and matrix metaloproteinases 9/2 in the peri-infarct area were detected by RT-PCR and western blot analysis. The pathomorphological change in the infract area was observed by hematoxylin-eosin staining. The expression level of glial fibrilary acidic protein was detected by immunohistochemistry. At 24 hours and 3 days after hyperbaric oxygen therapy and at 1 and 2 weeks after middle cerebral artery occlusion, neurological behaviors were evaluated using Longa behavioral scores. RESULTS AND CONCLUSION:After 1, 2 days of hyperbaric oxygen therapy, Longa behavioral scores in the hyperbaric oxygen therapy group were significantly lower than those in the cerebral infarction group (P < 0.05). At 3 days after middle cerebral artery occlusion, cel apoptosis index in the hyperbaric oxygen therapy group was significantly lower than that in the cerebral infarction group (P < 0.05). At 72 hours after middle cerebral artery occlusion, the aquaporin 4/9, matrix metaloproteinases 9/2 gene and protein expression in the hyperbaric oxygen group were significantly lower than those in the cerebral infarction group (P < 0.05). These results suggest that hyperbaric oxygen therapy can play its protective role by decreasing apoptosis of nerve cels in the infarct area and lessening

  11. Rate of change in cerebral oxygenation and blood pressure in response to passive changes in posture: a comparison between pure autonomic failure patients and controls.

    Science.gov (United States)

    Tachtsidis, Ilias; Elwell, Clare E; Leung, Terence S; Bleasdale-Barr, Katharine; Hunt, Katharine; Toms, Nathan; Smith, Martin; Mathias, Christopher J; Delpy, David T

    2005-01-01

    The cardiovascular and cerebrovascular responses to head-up postural change are compromised in pure autonomic failure (PAF) patients because of sympathetic denervation. The aim of this study was to characterize the rate of change of systemic mean blood pressure (MBP) and cerebral haemodynamics in response to passive posture changes. Nine PAF patients and 9 age-matched controls took part in this study. MBP and oxy- (O2Hb), deoxy-haemoglobin (HHb), and tissue oxygenation index (TOI) on the forehead were continuously monitored non-invasively using the Portapres and near-infrared spectroscopy (NIRS), respectively. From visual inspection of the haemoglobin difference signal (Hb(diff) = O2Hb-HHb), seven distinct phases were marked (1: supine, 2: start passive tilt, 3: head up to 60 degrees degrees, 4: end of tilt, 5: tilt reversal, 6: return to supine, 7: rest); the same time points were used for all of the other signals. For each phase, the slope was calculated using a linear regression algorithm. Significant differences were found between PAF patients and controls in the Hb(diff) slope magnitudes for phases 3 (P rate of change suggest differences in blood vessel resistance related to sympathetic activation.

  12. Development and characterization of a novel immobilized microbial membrane for rapid determination of biochemical oxygen demand load in industrial waste-waters.

    Science.gov (United States)

    Rastogi, Shikha; Kumar, Anil; Mehra, N K; Makhijani, S D; Manoharan, A; Gangal, V; Kumar, Rita

    2003-01-01

    The rapid determination of waste-water quality of waste-water treatment plants in terms of pollutional strength, i.e. biochemical oxygen demand (BOD) is difficult or even impossible using the chemical determination method. The present study reports the determination of BOD within minutes using microbial BOD sensors, as compared to the 5-day determination using the conventional method. Multiple criteria establish the basis for the development of a BOD biosensor useful for rapid and reliable BOD estimation in industrial waste-waters. Of these, preparation of a suitable novel immobilized microbial membrane used in conjunction with an apt transducer is discussed. As a result, a microbial biosensor based on a formulated, synergistic, pre-tested microbial consortium has been developed for the measurement of BOD load of various industrial waste-waters. The sensor showed maximum response in terms of current difference, when a cell concentration of 2.25 x 10(10) CFU, harvested in their log phase of growth were utilized for microbial membrane construction. The sensor showed a stability of 180 days when the prepared membranes were stored at a temperature of 4 degrees C in 50 mM phosphate buffer of pH 6.8. The reusability of the immobilized membranes was up to 200 cycles without appreciable loss of their response characteristics. A linear relationship between the current change and a glucose-glutamic acid (GAA) concentration up to 60 mg l(-1) was observed (r=0.999). The lower detection limit was 1.0 mg l(-1) BOD. The sensor response was reproducible within +/-5% of the mean in a series of ten samples having 44 mg l(-1) BOD using standard a GGA solution. When used for the BOD estimation of industrial waste-waters, a relatively good agreement was found between the two methods, i.e. 5-day BOD and that measured by the developed microbial sensor.

  13. Long-term effects of antibiotics on the elimination of chemical oxygen demand, nitrification, and viable bacteria in laboratory-scale wastewater treatment plants.

    Science.gov (United States)

    Schmidt, Susan; Winter, Josef; Gallert, Claudia

    2012-10-01

    Antibiotics and other pharmaceuticals are contaminants of the environment because of their widespread use and incomplete removal by microorganisms during wastewater treatment. The influence of a mixture of ciprofloxacin (CIP), gentamicin (GM), sulfamethoxazole (SMZ)/trimethoprim (TMP), and vancomycin (VA), up to a final concentration of 40 mg/L, on the elimination of chemical oxygen demand (COD), nitrification, and survival of bacteria, as well as the elimination of the antibiotics, was assessed in a long-term study in laboratory treatment plants (LTPs). In the presence of 30 mg/L antibiotics, nitrification of artificial sewage by activated sludge ended at nitrite. Nitrate formation was almost completely inhibited. No nitrification at all was possible in the presence of 40 mg/L antibiotics. The nitrifiers were more sensitive to antibiotics than heterotrophic bacteria. COD elimination in antibiotic-stressed LTPs was not influenced by ≤20 mg/L antibiotics. Addition of 30 mg/L antibiotic mixture decreased COD removal efficiency for a period, but the LTPs recovered. Similar results were obtained with 40 mg/L antibiotic mixture. The total viable count of bacteria was not affected negatively by the antibiotics. It ranged from 2.2 × 10(6) to 8.2 × 10(6) colony-forming units per milliliter (CFU/mL) compared with the control at 1.4 × 10(6)-6.3 × 10(6) CFU/mL. Elimination of the four antibiotics during phases of 2.4-30 mg/L from the liquid was high for GM (70-90 %), much lower for VA, TMP, and CIP (0-50 %), and highly fluctuating for SMZ (0-95 %). The antibiotics were mainly adsorbed to the sludge and not biodegraded.

  14. Comparison of Poly Aluminum Chloride and Chlorinated Cuprous for Chemical Oxygen Demand and Color Removal from Kashan Textile Industries Company Wastewater

    Directory of Open Access Journals (Sweden)

    Hoseindoost Gh.1 MSPH,

    2016-08-01

    Full Text Available Aims Textile wastewaters are the most important health and environmental problems in Kashan. This research was aimed to compare the poly aluminum chloride and chlorinated cuprous efficiency for removal of Chemical Oxygen Demand (COD and color from Kashan Textile Industries Company wastewater. Materials & Methods This experimental bench scale study in a batch system was conducted on 20 composed wastewater samples collected from Kashan Textile Industries Company raw wastewater. During 5 months, in the beginning of every week a day was selected randomly and in the day a composed sample was taken and studied. PAC at the doses of 10, 20, 30, 40 and 50mg.l-1 and chlorinated cuprous at the doses of 100, 200, 300, 400 and 500mg.l-1 were applied. The optimum pH also optimum concentration of PAC and chlorinated cuprous were determined using Jar test. The data was analyzed by SPSS 16 using descriptive statistics and Fisher Exact test. Findings The average concentration of COD in the raw textile wastewater was 2801.56±1398.29mg.l-1. The average COD concentration has been decreased to 1125.47±797.55mg.l-1. There was a significant difference between the effects of these two coagulants efficiency (p<0.05. The average COD removal efficiency for chlorinated cuprous and PAC was 58.52% and 72.56%, respectively. Also, the average color removal efficiency by chlorinated cuprous and PAC were 17.23 and 64.45%, respectively. Conclusion PAC is more efficient than chlorinated cuprous for both COD and color removal from KTIC wastewater.

  15. 海水化学需氧量烘箱加热测定方法的研究%Determination of seawater chemical oxygen demand by oven heating

    Institute of Scientific and Technical Information of China (English)

    沈加正; 侯沙沙; 刘鹰; 罗荣强

    2011-01-01

    A method for the determination of seawater chemical oxygen demand (COD), using oven instead of electric furnace to heat samples, was proposed. In this study, standard samples were heated under different conditions of temperature and time to obtain optimum heating conditions. The concentration range of the method was then assessed under the optimum operation conditions. In the end the method was applied to analyze seawater samples in comparison with the electric furnace method. All these results showed a good accuracy and precision of the oven heating method with less time and energy consumed, expecially when a large number of samples were ana- lyzed simultaneously.%在海水化学需氧量(COD)测定中,利用烘箱代替海洋监测规范中的电炉对样品进行加热;探讨了烘箱加热测定法所需的加热条件及其测定范围,并通过实际水样测定了解此法的精确度和准确度。结果表明,烘箱加热测定法具有与海洋监测规范方法同等水平的精确度和准确度,并且在大批量样品测定中具有省时、省电、省力的优点,具有较好的应用价值。

  16. Co-Digestion of Palm Oil Mill Effluent and Refined Glycerin Wash Water for Chemical Oxygen Demand Removal and Methane Production

    Directory of Open Access Journals (Sweden)

    A. Sulaiman

    2009-01-01

    Full Text Available Problem statement: Refined Glycerin Wash Water (RGWW from the oleochemical industry contains high Chemical Oxygen Demand (COD and requires proper treatment before disposal. Unfortunately the wash water also contains high concentration of sodium chloride (NaCl that could cause inhibition to the normal biological treatment process. However, there is feasibility of co-digesting the RGWW and Palm Oil Mill Effluent (POME for its treatment and methane recovery. Approach: A large 500 m3 semi-commercial closed digester tank was used to study the effect of co-digesting POME and RGWW under mesophilic condition at different RGWW percentage. The digester performance in terms of COD removal efficiency and methane production rate and stability based on total Volatile Fatty Acids (VFA accumulation, Mixed Liquor Volatile Suspended Solid (MLVSS and pH were evaluated. Results: At 1.0% of RGWW co-digested, both COD removal efficiency and methane production rate showed satisfactory results with higher than 90% and 505 m3 day-1, respectively. However, once the percentage was increased to a maximum of 5.25%, COD removal efficiency remains high but the methane production rate reduced significantly down to 307 m3 day-1. At this stage, the digester was already unstable with high total VFA recorded of 913 mg L-1 and low cells concentration of 8.58 g L-1. This was probably due to the effect of plasmolysis on the methanogens at high concentration of NaCl in the digester of nearly 4000 mg L-1. Conclusion: Co-digesting of RGWW with high NaCl content and POME is satisfactory for COD removal but not for increasing the methane production.

  17. Development of variable pathlength UV-vis spectroscopy combined with partial-least-squares regression for wastewater chemical oxygen demand (COD) monitoring.

    Science.gov (United States)

    Chen, Baisheng; Wu, Huanan; Li, Sam Fong Yau

    2014-03-01

    To overcome the challenging task to select an appropriate pathlength for wastewater chemical oxygen demand (COD) monitoring with high accuracy by UV-vis spectroscopy in wastewater treatment process, a variable pathlength approach combined with partial-least squares regression (PLSR) was developed in this study. Two new strategies were proposed to extract relevant information of UV-vis spectral data from variable pathlength measurements. The first strategy was by data fusion with two data fusion levels: low-level data fusion (LLDF) and mid-level data fusion (MLDF). Predictive accuracy was found to improve, indicated by the lower root-mean-square errors of prediction (RMSEP) compared with those obtained for single pathlength measurements. Both fusion levels were found to deliver very robust PLSR models with residual predictive deviations (RPD) greater than 3 (i.e. 3.22 and 3.29, respectively). The second strategy involved calculating the slopes of absorbance against pathlength at each wavelength to generate slope-derived spectra. Without the requirement to select the optimal pathlength, the predictive accuracy (RMSEP) was improved by 20-43% as compared to single pathlength spectroscopy. Comparing to nine-factor models from fusion strategy, the PLSR model from slope-derived spectroscopy was found to be more parsimonious with only five factors and more robust with residual predictive deviation (RPD) of 3.72. It also offered excellent correlation of predicted and measured COD values with R(2) of 0.936. In sum, variable pathlength spectroscopy with the two proposed data analysis strategies proved to be successful in enhancing prediction performance of COD in wastewater and showed high potential to be applied in on-line water quality monitoring.

  18. Cerebral blood oxygenation changes during neuronal activation in stroke patients measured by near infrared spectroscopy and BOLD-functional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Yoshihiro; Fukaya, Chikashi; Sakatani, Kaoru; Katayama, Yoichi [Nihon Univ., Tokyo (Japan). School of Medicine

    2002-03-01

    Blood Oxygenation Level Dependent (BOLD)-fMRI images areas of activation by detecting a reduced concentration of deoxyhemoglobin during neuronal activity, which is caused by a larger increase in O{sub 2} delivery as compared to O{sub 2} consumption in normal adults. In the present study, near infrared spectroscopy demonstrated an increase of deoxyhemoglobin associated with increases of oxyhemoglobin and total hemoglobin in activation areas of stroke patients, whereas BOLD-fMRI failed to image such activation areas. The findings obtained have serious implications for the application of BOLD-fMRI to patients with brain disorders, since BOLD-fMRI may overlook neuronal activities in these patients. (author)

  19. GABAA Receptor-Mediated Bidirectional Control of Synaptic Activity, Intracellular Ca2+, Cerebral Blood Flow, and Oxygen Consumption in Mouse Somatosensory Cortex In Vivo

    DEFF Research Database (Denmark)

    Jessen, Sanne Barsballe; Brazhe, Alexey; Lind, Barbara Lykke

    2015-01-01

    Neural activity regulates local increases in cerebral blood flow (ΔCBF) and the cortical metabolic rate of oxygen (ΔCMRO2) that constitutes the basis of BOLD functional neuroimaging signals. Glutamate signaling plays a key role in brain vascular and metabolic control; however, the modulatory effe...... selectively gate and amplify transient low-frequency somatosensory inputs, filter out high-frequency inputs, and enhance vascular and metabolic responses that are likely to be reflected in BOLD functional neuroimaging signals....

  20. Cerebral Oximetry in Ugandan Children With Severe Anemia: Clinical Categories and Response to Transfusion.

    Science.gov (United States)

    Dhabangi, Aggrey; Ainomugisha, Brenda; Cserti-Gazdewich, Christine; Ddungu, Henry; Kyeyune, Dorothy; Musisi, Ezra; Opoka, Robert; Stowell, Christopher P; Dzik, Walter H

    2016-10-01

    Severe anemia, defined as a hemoglobin level of less than 5.0 g/dL, affects millions of children worldwide. The brain has a high basal demand for oxygen and is especially vulnerable to hypoxemia. Previous studies have documented neurocognitive impairment in children with severe anemia. Data on cerebral tissue oxygenation in children with severe anemia and their response to blood transfusion are limited. To measure hemoglobin saturation in cerebral tissue (cerebral tissue oxygen saturation [tSo2]) before, during, and after blood transfusion in a cohort of children presenting to hospital with severe anemia. This was a prospective, observational cohort study conducted from February 2013 through May 2015 and analyzed in July 2015 at a university hospital pediatric acute care facility in Kampala, Uganda, of 128 children, ages 6 to 60 months who were enrolled in a larger clinical trial, with a presenting hemoglobin level of less than 5.0 g/dL and a blood lactate level greater than 5mM. Most children had either malaria or sickle cell disease. Red blood cell (RBC) transfusion given as 10 mL/kg over 120 minutes. Clinical and laboratory characteristics of children with pretransfusion cerebral tSo2 levels less than 65%, 65% to 75%, and greater than 75%. Change in cerebral tSo2 as a result of transfusion. Of 128 children included in the study, oximetry results in 8 cases were excluded owing to motion artifacts; thus, 120 were included in this analysis. Cerebral tSo2 values prior to transfusion ranged from 34% to 87% (median, 72%; interquartile range [IQR], 65%-76%). Eighty-one children (67%) demonstrated an initial cerebral tSo2 level (≤75%) corresponding to an oxygen extraction ratio greater than 0.36. Patients with sickle cell disease (n = 17) and malaria (n = 15) contributed in nearly equal numbers to the subgroup with an initial cerebral tSo2 (children failed to achieve a tSo2 level greater than 75%. Severe anemia in children is frequently associated with low

  1. Effect of ultraviolet blood irradiation and oxygenation on nerve function and function of the red blood cell membrane pump in patients with acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Jiaquan Wang; Chun Mao; Kaifu Ma; Shiqing Wang

    2006-01-01

    BACKGROUND: Ultraviolet blood irradiation and oxygenation (UBIO) has obtained better clinical effect in treating acute cerebral infarction, but the mechanism underlying this effect remains unclear.OBJECTIVE: To observe the effect of UBIO on the nerve function and activities of K+-Na+-ATPase and Ca2+-Mg2+-ATPase activities on the red blood cell (RBC) membrane of patients with acute cerebral infarction.DESIGN: A randomized and controlled study.SETTING: Department of Neurology, Xiangfan Central Hospital.PARTICIPANTS: From January 2000 to December 2001, excluding those above 70 years old, 58 cases of 700 patients with acute cerebral infarction admitted in the Department of Neurology, Xiangfan Central Hospital, were recruited and divided into two groups according to the random number table: UBIO treated group (n=28), including 17 males and 11 females, aged 40-68 years; and control group (n=30), including 20males and 10 females, aged 44-69 years. All the patients agreed to participate in the therapeutic program and detected items. The general informations were comparable without obvious differences between the two groups (P > 0.05).METHODS: ① The patients in both groups received routine treatments, besides, those in the UBIO treated group were given UBIO treatment by using the XL-200 type therapeutic apparatus produced in Shijiazhuang, whose ultraviolet wave was set at 253.7 nm with the energy density of 0.568 J/m2 per second, UBIO treatment started from the second day after admission, once every other day, with a single course consisting of 5-7 treatments. ② In the UBIO treated group, the venous blood was sampled before and after the first, third and the completion of the treatment course respectively, the venous blood was taken at each corresponding time point in the control group. After centrifugation of the blood at 10 000 rounds per minute,the RBC membrane was separated and then the activities of K+-Na+-ATPase and Ca2+-Mg2+-ATPase were detected by means of

  2. Improved cerebral oxygenation response and executive performance as a function of cardiorespiratory fitness in older women: a fNIRS study

    Directory of Open Access Journals (Sweden)

    Cédric T Albinet

    2014-10-01

    Full Text Available Cardiorespiratory fitness has been shown to protect and enhance cognitive and brain functions, but little is known about the cortical mechanisms that underlie these changes in older adults. In this study, functional NIRS was used to investigate variations in oxyhemoglobin ([HbO2] and in deoxyhemoglobin ([HHb] in the dorsolateral prefrontal cortex (DLPFC during the performance of an executive control task in older women with different levels of cardiorespiratory fitness (VO2max. Thirty-four women aged 60-77 years were classified as high-fit and low-fit based on VO2max measures. They all performed a control counting task and the Random Number Generation (RNG task at two different paces (1 number / 1 s and 1 number / 1.5 s, allowing to manipulate task difficulty, while hemodynamic responses in the bilateral DLPFCs were recorded using continuous-wave NIRS. The behavioral data revealed that the high-fit women showed significantly better performance on the RNG tasks compared with the low-fit women. The high-fit women showed significant increases in [HbO2] responses in both left and right DLPFCs during the RNG task, while the low-fit women showed significantly less activation in the right DLPFC compared with the right DLPFC of the high-fit women and compared with their own left DLPFC. At the level of the whole sample, increases in the [HbO2] responses in the right DLPFC were found to mediate in part the relationship between VO2max level and executive performance during the RNG task at 1.5 s but not at 1 s. These results provide support for the cardiorespiratory fitness hypothesis and suggest that higher levels of aerobic fitness in older women are related to increased cerebral oxygen supply to the DLPFC, sustaining better cognitive performance.

  3. Clinical study of early hyperbaric oxygen therapy for cerebral resuscitation%早期应用高压氧进行脑复苏的临床研究

    Institute of Scientific and Technical Information of China (English)

    潘树义; 孟祥恩; 李铭鑫; 张禹; 吕艳; 杨晨; 张良; 刘文成

    2011-01-01

    Objective To observe the effect of early hyperbaric oxygen (HBO) therapy on cerebral resuscitation and to provide good evidence and method for the treatment of cerebral resuscitation.Methods The patients responded to cardiac pulmonary resuscitation (CPR) were divided into 2 groups,the early HBO group( within one week of onset) and the delayed HBO group (after 1 week of onset).All the patients were given routine medicinal treatment coupled with HBO therapy.The exposure pressure of HBO and the course of treatment were all the same,only the time point of HBO intervention was different.Evaluation was made by using "the Revised 2001 PVS Criteria for Diagnosis and Treatment" ( the Nanjing Criteria).Consciousness of the patients was evaluated both before HBO therapy and 6 months after onset.Results Of the 18 patients who received early HBO therapy,4 patients recovered and returned to normal life (effective),5 patients became fully conscious,but with minor disability (effective),and 9 patients became vegetable (ineffective),with a total effective rate of 50.0%.Of the 53 patients with delayed HBO therapy,9 patients recovered and returned to normal life (effective),15 patients became fully conscious,but with minor disability (effective),and 29 patients became vegetable (ineffective),with a total effective rate of 45.3%.No significant differences could be seen in effective rates between the 2 groups (P >0.05).However,statistical significance could be noted,when effective rates of the 2 groups were compared with those presented in domestic and international reports (2%-10% ) ( P < 0.05 ).Conclusions In-time HBO therapy could improve prognosis of some patients following cardiac resuscitation,protect neural cells,and improve the intelligence of patients,however,early and ultra-early HBO therapy could not increase the effective rate of cerebral resuscitation.%目的 观察早期高压氧( hyperbaric oxygen,HBO)治疗对脑复苏成功率的影响,为临床脑复苏

  4. Comparison of cerebral tissue oxygenation values in full term and preterm newborns by the simultaneous use of two near-infrared spectroscopy devices: an absolute and a relative trending oximeter

    Science.gov (United States)

    Szczapa, Tomasz; Karpiński, Łukasz; Moczko, Jerzy; Weindling, Michael; Kornacka, Alicja; Wróblewska, Katarzyna; Adamczak, Aleksandra; Jopek, Aleksandra; Chojnacka, Karolina; Gadzinowski, Janusz

    2013-08-01

    The aim of this study is to compare a two-wavelength light emitting diode-based tissue oximeter (INVOS), which is designed to show trends in tissue oxygenation, with a four-wavelength laser-based oximeter (FORE-SIGHT), designed to deliver absolute values of tissue oxygenation. Simultaneous values of cerebral tissue oxygenation (StO2) are measured using both devices in 15 term and 15 preterm clinically stable newborns on the first and third day of life. Values are recorded simultaneously in two periods between which oximeter sensor positions are switched to the contralateral side. Agreement between StO2 values before and after the change of sensor position is analyzed. We find that mean cerebral StO2 values are similar between devices for term and preterm babies, but INVOS shows StO2 values spread over a wider range, with wider standard deviations than shown by the FORE-SIGHT. There is relatively good agreement with a bias up to 3.5% and limits of agreement up to 11.8%. Measurements from each side of the forehead show better repeatability for the FORE-SIGHT monitor. We conclude that performance of the two devices is probably acceptable for clinical purposes. Both performed sufficiently well, but the use of FORE-SIGHT may be associated with tighter range and better repeatability of data.

  5. Crew Cerebral Oxygen Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase II SBIR proposal is aimed at developing a non-invasive, optical method for monitoring crew member state of awareness in operational environments. All...

  6. Crew Cerebral Oxygen Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR proposal is aimed at developing a non-invasive, optical method for monitoring the state of consciousness of crew members in operational...

  7. Prediction of Outcome in Neonates with Hypoxic-Ischemic Encephalopathy II: Role of Amplitude-Integrated Electroencephalography and Cerebral Oxygen Saturation Measured by Near-Infrared Spectroscopy.

    Science.gov (United States)

    Goeral, Katharina; Urlesberger, Berndt; Giordano, Vito; Kasprian, Gregor; Wagner, Michael; Schmidt, Lisa; Berger, Angelika; Klebermass-Schrehof, Katrin; Olischar, Monika

    2017-07-14

    Few data have been published on the combined use of amplitude-integrated electroencephalography (aEEG) and near-infrared spectroscopy (NIRS) for outcome prediction in neonates cooled for hypoxic-ischemic encephalopathy (HIE). Our aim was to evaluate the predictive values and the most powerful predictive combinations of single aEEG and NIRS parameters and the respective cut-off values with regard to short-term outcomes in HIE II. aEEG and NIRS were prospectively studied at the Medical University of Vienna in the first 102 h of life with regard to magnetic resonance imaging (MRI). Thirty-two neonates diagnosed with HIE II treated with hypothermia were investigated. The measurement period was divided into 6-h epochs. According to MRI, 2 outcome groups were defined and predictive values of aEEG parameters, regional cerebral oxygen saturation (rScO2), and the additional value of both methods combined were studied. Receiver operating curves (ROC) were obtained and area under the curve (AUC) values were calculated. ROC were then used to detect the optimal cut-off points, sensitivity, specificity, positive predictive values, and negative predictive values. At all time epochs, combined parameter scores were more predictive than single parameter scores. The highest AUC were observed between 18 and 60 h of cooling for the aEEG summation score (0.72-0.84) and for (background pattern + seizures) × rScO2 (0.79-0.85). At 42-60 h sensitivity was similar between those 2 scores (87.5-90.0%), but the addition of NIRS to aEEG led to an increase in specificity (from 52.4-59.1% to 72.7-90.5%). In HIE II, aEEG and NIRS are important predictors of short-term outcome. The combination of both methods improves prognostication. The highest predictive abilities were observed between 18 and 60 h of cooling. © 2017 S. Karger AG, Basel.

  8. Energy Demand

    NARCIS (Netherlands)

    Stehfest, E. et al.

    2014-01-01

    Key policy issues – How will energy demand evolve particularly in emerging and medium- and low- income economies? – What is the mix of end-use energy carriers to meet future energy demand? – How can energy efficiency contribute to reducing the growth rate of energy demand and mitigate pressures on t

  9. Malaria cerebral Cerebral malaria

    OpenAIRE

    Carlos Hugo Zapata Zapata; Silvia Blair Trujillo

    2003-01-01

    La malaria Cerebral (MC) es la complicación más frecuente de la malaria por P. falciparum; aproximadamente el 90% de las personas que la han padecido se recuperan completamente sin secuelas neurológicas. Aún no se conoce con claridad su patogénesis pero se han postulado cuatro hipótesis o mecanismos posibles: 1) citoadherencia y secuestro de glóbulos rojos parasitados en la microvasculatura cerebral; 2) formación de rosetas y aglutinación de glóbulos rojos parasitados; 3) producción de citoqu...

  10. Clinical value and influencing factors of intraoperative monitoring of jugular venous oxygen saturation

    Directory of Open Access Journals (Sweden)

    Jie SONG

    2016-10-01

    Full Text Available Intraoperative jugular venous oxygen saturation (SjvO2 monitoring has been widely used in clinic, which can monitor cerebral blood flow (CBF and oxygen metabolism. Reverse puncture and catheterization through jugular vein for monitoring SjvO2 is easy to operate and can collect blood samples repeatedly. It is an effective method for real-time dynamic evaluation of cerebral oxygen supply-demand and neurological function. This article reviews the clinical significance and influencing factors of SjvO2 monitoring during operation. It notes in particular that SjvO2 can not be used as the only way to monitor CBF and oxygen metabolism, and a comprehensive evaluation should be done combining with the change of other parameters. DOI: 10.3969/j.issn.1672-6731.2016.10.014

  11. The imbalance between oxygen demand and supply as a potential mechanism in the pathophysiology of heart failure : The role of microvascular growth and abnormalities

    NARCIS (Netherlands)

    De Boer, RA; Pinto, YM; van Veldhuisen, DJ

    2003-01-01

    In heart failure., a deficient oxygen supply often is a primary cause for myocardial dysfunction. The reverse however, may also be true; the changes that occur in the failing heart may predispose for the existence of tissue hypoxia, which further affects the function of the heart. Specifically, myoc

  12. Ataque cerebral

    OpenAIRE

    Takeuchi Tan, Yuri; Fundación Valle de Lili

    1998-01-01

    ¿Qué es un ataque cerebral?/¿Qué tipos de ataque cerebral existen?/¿Cuáles son los síntomas de un ataque cerebral?/Factores de riesgo para un ataque cerebral/Tratamiento médico del ataque cerebral/¿por qué es importante acudir temprano cuando se presentan las señales de alarma?/ Manejo preventivo del ataque cerebral isquémico/Tratamiento quirúrgico del ataque cerebral/Enfermedad vascular cerebral hemorrágica/¿Cómo está constituido el grupo de ataque cerebral de la fundación Clínica Valle d...

  13. Ataque cerebral

    OpenAIRE

    Takeuchi Tan, Yuri; Fundación Valle de Lili

    1998-01-01

    ¿Qué es un ataque cerebral?/¿Qué tipos de ataque cerebral existen?/¿Cuáles son los síntomas de un ataque cerebral?/Factores de riesgo para un ataque cerebral/Tratamiento médico del ataque cerebral/¿por qué es importante acudir temprano cuando se presentan las señales de alarma?/ Manejo preventivo del ataque cerebral isquémico/Tratamiento quirúrgico del ataque cerebral/Enfermedad vascular cerebral hemorrágica/¿Cómo está constituido el grupo de ataque cerebral de la fundación Clínica Valle d...

  14. Cerebral Palsy. Fact Sheet = La Paralisis Cerebral. Hojas Informativas Sobre Discapacidades.

    Science.gov (United States)

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet on cerebral palsy is written in both English and Spanish. First, it provides a definition of cerebral palsy and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy:…

  15. Cytochrome c oxidase response to changes in cerebral oxygen delivery in the adult brain shows higher brain-specificity than haemoglobin ☆

    OpenAIRE

    Kolyva, Christina; Ghosh, Arnab; Tachtsidis, Ilias; Highton, David; Chris E Cooper; Smith, Martin; Elwell, Clare E.

    2014-01-01

    The redox state of cerebral mitochondrial cytochrome c oxidase monitored with near-infrared spectroscopy (Δ[oxCCO]) is a signal with strong potential as a non-invasive, bedside biomarker of cerebral metabolic status. We hypothesised that the higher mitochondrial density of brain compared to skin and skull would lead to evidence of brain-specificity of the Δ[oxCCO] signal when measured with a multi-distance near-infrared spectroscopy (NIRS) system. Measurements of Δ[oxCCO] as well as of concen...

  16. Effect on nickel loading on hydrogen production and chemical oxygen demand (COD) destruction from glucose oxidation and gasification in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, E.A.; Chowdhury, M.B.I.; Nakhla, G.; Charpentier, P. [Western Ontario University, London, ON (Canada). Dept. of Biochemical and Chemical Engineering

    2009-07-01

    Hydrogen produced from biomass is considered to be an excellent alternative to the use of fossil fuels. Gasification and partial oxidation of glucose was performed in the presence of different metallic nickel (Ni) loadings on different catalyst supports in supercritical water at three temperature levels. For comparison, some experiments were conducted using high loading commercial catalyst Ni on silica-alumina. Hydrogen peroxide was used as a source of oxygen in the partial oxidation experiments. Oxygen to carbon stoichiometric ratios of 0.5 to 0.9 were examined to increase the hydrogen production via carbon monoxide production. The paper described the experimental and methods as well as results and discussion. Results showed that in the absence of catalyst, the optimum stoichiometric ratio was 0.8 of the amount of oxygen required for complete oxidation of glucose. It was concluded that enhancing hydrogen yield and selectivity from glucose by obtaining the desired catalytic property and the optimum process conditions and parameters would be an invaluable addition to the supercritical water oxidation technology. 24 refs., 2 tabs., 5 figs.

  17. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas

    2015-01-01

    OBJECTIVE: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. DESIGN: Phase II randomised, single blinded, parallel clinical trial. SETTING: Eight tertiary neonatal intensive care units...

  18. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas;

    2015-01-01

    OBJECTIVE: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. DESIGN: Phase II randomised, single blinded, parallel clinical trial. SETTING: Eight tertiary neonatal intensive care units...

  19. Role of H2O2 in the fluctuating patterns of COD (chemical oxygen demand) during the treatment of palm oil mill effluent (POME) using pilot scale triple frequency ultrasound cavitation reactor.

    Science.gov (United States)

    Manickam, Sivakumar; Abidin, Norhaida binti Zainal; Parthasarathy, Shridharan; Alzorqi, Ibrahim; Ng, Ern Huay; Tiong, Timm Joyce; Gomes, Rachel L; Ali, Asgar

    2014-07-01

    Palm oil mill effluent (POME) is a highly contaminating wastewater due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Conventional treatment methods require longer residence time (10-15 days) and higher operating cost. Owing to this, finding a suitable and efficient method for the treatment of POME is crucial. In this investigation, ultrasound cavitation technology has been used as an alternative technique to treat POME. Cavitation is the phenomenon of formation, growth and collapse of bubbles in a liquid. The end process of collapse leads to intense conditions of temperature and pressure and shock waves which assist various physical and chemical transformations. Two different ultrasound systems i.e. ultrasonic bath (37 kHz) and a hexagonal triple frequency ultrasonic reactor (28, 40 and 70 kHz) of 15 L have been used. The results showed a fluctuating COD pattern (in between 45,000 and 60,000 mg/L) while using ultrasound bath alone, whereas a non-fluctuating COD pattern with a final COD of 27,000 mg/L was achieved when hydrogen peroxide was introduced. Similarly for the triple frequency ultrasound reactor, coupling all the three frequencies resulted into a final COD of 41,300 mg/L compared to any other individual or combination of two frequencies. With the possibility of larger and continuous ultrasonic cavitational reactors, it is believed that this could be a promising and a fruitful green process engineering technique for the treatment of POME.

  20. Cerebral Palsy

    Science.gov (United States)

    Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

  1. Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen saturation in old and young adults with near-infrared spectroscopy

    Science.gov (United States)

    We present near-infrared spectroscopy measurement of absolute cerebral hemoglobin concentration and saturation in a large sample of 36 healthy elderly (mean age, 85 ± 6 years) and 19 young adults (mean age, 28 ± 4 years). Non-invasive measurements were obtained on the forehead using a commercially a...

  2. Cerebral malaria Malaria cerebral

    OpenAIRE

    Silvia Blair Trujillo; Carlos Hugo Zapata Zapata

    2003-01-01

    Is the most common complication of P. falciparum malaria; nearly 90% of people who have suffered CM can recover without neurological problems. Currently there are four hypotheses that explain pathogenesis of CM: cytoadherence and sequestering of parasitized red blood cells to cerebral capillaries; rosette formation and parasitized red blood cells agglutination; production of cytokines and activation of second messengers and opening of the blood-brain barrier. However the main question remains...

  3. Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Fisher, James P; Young, Colin N

    2010-01-01

    Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebral...... abolished by glycopyrrolate (P perfusion without affecting the cerebral metabolic rate for oxygen....

  4. Cerebral malaria Malaria cerebral

    Directory of Open Access Journals (Sweden)

    Silvia Blair Trujillo

    2003-03-01

    Full Text Available Is the most common complication of P. falciparum malaria; nearly 90% of people who have suffered CM can recover without neurological problems. Currently there are four hypotheses that explain pathogenesis of CM: cytoadherence and sequestering of parasitized red blood cells to cerebral capillaries; rosette formation and parasitized red blood cells agglutination; production of cytokines and activation of second messengers and opening of the blood-brain barrier. However the main question remains to be answered; how the host-parasite interaction in the vascular space interferes transiently with cerebral function? Recently, the beta amyloid precursor peptide has been employed as marker of neural injury in CM. It is expected that the beta amyloid precursor peptide will help to understand the pathogenesis of CM in complicated patients of endemic areas of Colombia. La malaria Cerebral (MC es la complicación más frecuente de la malaria por P. falciparum; aproximadamente el 90% de las personas que la han padecido se recuperan completamente sin secuelas neurológicas. Aún no se conoce con claridad su patogénesis pero se han postulado cuatro hipótesis o mecanismos posibles: 1 citoadherencia y secuestro de glóbulos rojos parasitados en la microvasculatura cerebral; 2 formación de rosetas y aglutinación de glóbulos rojos parasitados; 3 producción de citoquinas y activación de segundos mensajeros y, 4 apertura de la barrera hematoencefálica. Sin embargo, queda un interrogante sin resolver aún: ¿qué proceso se lleva a cabo para que el parásito, desde el espacio microvascular, pueda interferir transitoriamente con la función cerebral? Recientemente se ha utilizado el precursor de la proteína b-Amiloide como un marcador de daño neuronal en MC; este precursor será de gran ayuda en futuras investigaciones realizadas en nuestro medio que aporten información para comprender la patogénesis de la MC.

  5. Demand Uncertainty

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen

    This paper presents a model of trade that explains why firms wait to export and why many exporters fail. Firms face uncertain demands that are only realized after the firm enters the destination. The model retools the timing of uncertainty resolution found in productivity heterogeneity models...... in untested destinations. The option to forecast demands causes firms to delay exporting in order to gather more information about foreign demand. Third, since uncertainty is resolved after entry, many firms enter a destination and then exit after learning that they cannot profit. This prediction reconciles...

  6. Demand forecasting

    OpenAIRE

    Gregor, Belčec

    2011-01-01

    Companies operate in an increasingly challenging environment that requires them to continuously improve all areas of the business process. Demand forecasting is one area in manufacturing companies where we can hope to gain great advantages. Improvements in forecasting can result in cost savings throughout the supply chain, improve the reliability of information and the quality of the service for our customers. In the company Danfoss Trata, d. o. o. we did not have a system for demand forecast...

  7. 早期脓毒症大鼠脑氧代谢与乳酸的变化%Preliminary study of cerebral oxygen metabolism and change of blood lactate in early stage of sepsis in rats

    Institute of Scientific and Technical Information of China (English)

    钱欣; 郑峥; 汤罗嘉; 陈锋

    2011-01-01

    Objective To observe the change of cerebral oxygen metablism and the level of blood lactate in early stage of sepsis in rats.Method Sixty-four SD rats were randomly(random number)divided into septic group and control group.The sepsis model of rat was made by lipopolysaccharide (LPS,10 mg/kg)injected intra-abdominally,and rats of control group were treated with the same amount of physiological saline instead.And each group was further divided into 4 sub-groups of4 h,6 h,12 h and 24 h after treatment.At each interval,blood samples were obtained via jugular vein for detecting blood oxygen saturation (Sjv02)and blood lactate(LA).The blood oxygen saturation(Sa02)of ventral aorta was also measured.Arteriovenous oxygen content difference (AVD02) and oxygen extraction fraction (OEF) were studied.These four variables were analyzed and compared between two groups.Results The AVD02 and OEF in sepsis group were higher than those in control groups of 3 h,6 h and 12 h (P0.05).LA in sepsis group was higher than that in control group in each interval (P0.05).脓毒症组各时间点LA含量与对照组相比均有不同程度升高,差异具有统计学意义(P<0.05).结论 脓毒症早期可出现脑贯注及脑氧摄取的增强;Sjv02,AVDO2,OEF结合LA水平的监测,能更准确的评估脓毒症早期脑供氧、耗氧和脑贯注状态.

  8. Research on the effect of remifentanil on cerebral oxygen metabolism and cerebral blood flow of patients with severe brain injury%瑞芬太尼对重型颅脑损伤患者脑氧代谢及脑血流的影响

    Institute of Scientific and Technical Information of China (English)

    王言武

    2014-01-01

    Objective To investigate the effect of remifentanil on cerebral oxygen metabolism and cerebral blood flow of patients with severe brain injury.Methods Retrospective analysis of the clinical data of the 64 cases with severe head injury ad-mitted to our hospital was processed. According to the anesthetic drugs ,64 cases were divided into treatment group and control group ,the control group was treated with fentanyl for anesthesia ,the treatment group was treated with remifentanil for anes-thesia. Cerebral oxygen metabolism and hemodynamic indexes of the two groups before anesthesia and after anesthesia for 10min were compared.Results Before anesthesia ,brain oxygen metabolism and hemodynamic parameters of the two groups were not significantly different ,P>0.05 ;10 min after anesthesia ,CERO2 of the treatment group was significantly higher than that of the control group ,CjvO2 ,Da-jvO2 are significantly lower than that of the control group ,P<0.05;Qmean ,Wv of the treatment group were significantly higher than those of the control group ;DR was significantly lower than that of the control group ,P<0.05.Conclusion Remifentanil anesthesia for patients with severe head injury surgery can improve cerebral oxygen metabolism and cerebral blood flow ,has high security.%目的:探讨瑞芬太尼对重型颅脑损伤患者脑氧代谢的影响。方法回顾性分析我院收治的64例重型颅脑损伤患者的临床资料,根据麻醉药物不同分为治疗组和对照组,对照组采用芬太尼麻醉,治疗组采用瑞芬太尼麻醉,比较2组患者麻醉前、麻醉后10 min时脑氧代谢指标和血流动力学指标。结果麻醉前2组患者的脑氧代谢指标和血流动力学指标比较均无显著性差异(P>0.05);麻醉后10 min治疗组CERO2显著高于对照组,CjvO2、Da-jvO2均显著低于对照组(P<0.05);治疗组Qmean、Wv显著高于对照组,DR显著低于对照组(P<0.05)。结论瑞芬太尼在重型颅脑损

  9. Neuroprotective effect of high-dose hyperbaric oxygenation on rats with acute cerebral infarction in super-early stage Curative comparison between 9-hour and 18-hour therapeutic protocols

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Previously, only single short-time low-dose hyperbaric oxygenation (HBO) protocol was administrated to treat acute ischemic stroke in early stage and the conflicting results were obtained. There are few studies to report the outcome of administering long-time (can cover all the natural pathologic progression period) high-dose HBO to treat the disease.OBJECTIVE: To evaluate the therapeutic effect between two kinds of high-dose hyperbaric oxygenation on super-early stage of acute permanent middle cerebral artery occlusion (MCAO) in rats.DESIGN: A randomized controlled experimental study.SETTING: Beijing Tiantan Hospital, Capital Medical University; Beijing Research Institute of Neurosurgery.MATERIALS: Seventy-four male SD rats, aged 2.5 months old, weighing (280±20) g, were provided by the Animal Institute, Chinese Academy of Medical Sciences. Hyperbaric oxygenation device was hyperbaric air cabin in which there was a self-made pure oxygen animal experimental cabin (made in China).METHODS: This experiment was carried out in the municipal laboratory of Beijing Tiantan Hospital affiliated to Capital Medical University and Beijing Research Institute of Neurosurgery. ① Experimental intervention: All the rats were developed into models of permanent MCAO by suture embolism. Then, they were randomly divided into two HBO groups (9hours and 18 hours) and control group, with 24 rats in each as well as 3-hour ultrastructure control group, with 2 rats. After being modeled for 3 hours, rats in the two HBO groups stayed in the hyperbaric cabin for 9 hours and 18 hours,separately. Rats in the 9-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7 and 9, and hyperbaric air at hours 2, 4, 6 and 8. Rats in the 18-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7, 9, 11, 13, 15 and 17, and hyperbaric air at hours 2, 4, 6, 8, 10 12, 14, 16 and 18. After being created into models, rats in the control group and 3-hour ultrastructure control group breathed room air.

  10. Demanding Satisfaction

    Science.gov (United States)

    Oguntoyinbo, Lekan

    2010-01-01

    It was the kind of crisis most universities dread. In November 2006, a group of minority student leaders at Indiana University-Purdue University Indianapolis (IUPUI) threatened to sue the university if administrators did not heed demands that included providing more funding for multicultural student groups. This article discusses how this threat…

  11. Cerebral energy metabolism during induced mitochondrial dysfunction

    DEFF Research Database (Denmark)

    Nielsen, T H; Bindslev, TT; Pedersen, S M

    2013-01-01

    In patients with traumatic brain injury as well as stroke, impaired cerebral oxidative energy metabolism may be an important factor contributing to the ultimate degree of tissue damage. We hypothesize that mitochondrial dysfunction can be diagnosed bedside by comparing the simultaneous changes in...... in brain tissue oxygen tension (PbtO(2)) and cerebral cytoplasmatic redox state. The study describes cerebral energy metabolism during mitochondrial dysfunction induced by sevoflurane in piglets....

  12. Head position change is not associated with acute changes in bilateral cerebral oxygenation in stable preterm infants during the first three days of life

    Science.gov (United States)

    Liao, Steve Ming-Che; Rao, Rakesh; Mathur, Amit M.

    2015-01-01

    Objective Several recent intraventricular hemorrhage prevention bundles include midline head positioning to prevent potential disturbances in cerebral hemodynamics. We aimed to study the impact of head position change on regional cerebral saturations (SctO2) in preterm infants (< 30 weeks GA) during the first three days of life. Study Design Bilateral SctO2 was measured by near infrared spectroscopy. The infant's head was turned sequentially to each side from midline (baseline) in thirty-minute intervals while keeping the body supine. Bilateral SctO2 before and after each position change were compared using paired t-test. Results In relatively stable preterm infants (gestational age 26.5±1.7 weeks, birth weight 930±220g; n=20), bilateral SctO2 remained within normal range (71.1% - 75.3%) when the head was turned from midline position to either side. Conclusion Stable preterm infants tolerated brief changes in head position from midline without significant alternation in bilateral SctO2; the impact on critically ill infants needs further evaluation. PMID:25282608

  13. 复杂水体中五日生化需氧量测定的硝化抑制%Inhibition to Nitriifcstion in Determination of Biochemical Oxygen Demand After Five Days in Complex Water

    Institute of Scientific and Technical Information of China (English)

    吴丽娟; 胡晓乐; 陆喜红

    2016-01-01

    Nitration reaction was inhibited by allyl thiourea. Biochemical oxygen demand after five days is oxygen amount consumed by the decomposition of organic pollutants in biochemistry process. Nitration reaction caused the estimated value significantly increased and even caused chemical oxygen demand more than biochemical oxygen demand. Through adding 0.1% allyl thiourea into dilution water, the method made B/C value of water sample come back to the normal value between 0.2 and 0.7. The results of the blank sample and the standard sample met the requirement of the national standard method. This method was effectively eliminating interference, simple operation, and reducing the risk of the test to select dilution ratio. It has no significant effects on water without interference, and also can simplify the determining procedure of large batches of compositional complicated water samples.%利用丙烯基硫脲对有机污染物硝化过程进行抑制。五日生化需氧量反映的是有机污染物生物氧化过程中碳化阶段的耗氧量,而硝化阶段会导致测定结果显著偏高。未知水样基体复杂,很难判断是否存在会引起硝化作用的硝化细菌,往往导致测定结果偏高甚至出现生化需氧量大于化学需氧量(即B/C值大于1)的不合理现象。向每升稀释水中加入0.1%的丙烯基硫脲硝化抑制剂,对基体复杂样品进行稀释后测定,使得样品的B/C值回到理论正常值(0.2~0.7)的范围内,对空白样品和标准样品的实验结果均满足国标方法的质控保证及要求。生化需氧量测定时间长而难以进行复测,该方法有效地排除了干扰,操作简便,降低了生化需氧量测定过程中稀释倍数选择不合适的风险,减小了工作量,提高了准确度。该方法对正常水样的测定结果不产生显著影响,适用于大批量复杂水体样品的测定。

  14. Monitoring of cerebral haemodynamics in newborn infants

    DEFF Research Database (Denmark)

    Liem, K Djien; Greisen, Gorm

    2010-01-01

    The most important cerebrovascular injuries in newborn infants, particularly in preterm infants, are cerebral haemorrhage and ischemic injury. The typical cerebral vascular anatomy and the disturbance of cerebral haemodynamics play important roles in the pathophysiology. The term 'cerebral...... haemodynamics' includes cerebral blood flow (CBF), cerebral blood flow velocity, and cerebral blood volume (CBV). Therapy aimed at changing vascular anatomy is not available. Therefore, prevention of disturbances in CBF and CBV is pivotal. However, continuous monitoring of CBF and CBV is still unavailable...... for clinical use. Tissue oxygenation may be used as a surrogate for CBF, although precision is still questionable. General knowledge of the regulation of CBF and CBV is important. Although this knowledge is still incomplete, especially regarding autoregulation and the exact role of CBV, it is still useful...

  15. Severe cerebral desaturation during shoulder arthroscopy in the beach-chair position

    DEFF Research Database (Denmark)

    Dippmann, Christian; Winge, Søren; Nielsen, Henning Bay

    2010-01-01

    During shoulder arthroscopy in the beach-chair position, cerebral ischemia may be a serious complication because prolonged hypotension may affect regional cerebral oxygen supply. We present the cases of 2 patients in whom a reduction in mean arterial pressure after anesthesia provoked a decrease...... cerebral oxygenation. During surgery in the beach-chair position, hypotension must be avoided, and in all patients regional, cerebral oxygenation should be monitored and optimized....

  16. Unchanged cerebral blood flow and oxidative metabolism after acclimatization to high altitude

    DEFF Research Database (Denmark)

    Møller, Kirsten; Paulson, Olaf B; Hornbein, Thomas F.

    2002-01-01

    . At high altitude at rest, arterial carbon dioxide tension, oxygen saturation, and oxygen tension were significantly reduced, and arterial oxygen content was increased because of an increase in hemoglobin concentration. Global cerebral blood flow was similar in the four conditions. Cerebral oxygen delivery...

  17. Medida da diferença artério-venosa de oxigênio na monitorização de pacientes com hemorragia subaracnóidea por aneurisma cerebral Measurement of arteriovenous oxygen difference in the monitoring of patients with subarachnoid haemorrhage due to cerebral aneurysm

    Directory of Open Access Journals (Sweden)

    Ronaldo Sérgio Santana Pereira

    1997-01-01

    Full Text Available A diferença artério-venosa de oxigênio (DAVO2, pelo fato de estar relacionada com o metabolismo cerebral, reflete alterações que ocorrem em determinadas situações patológicas, entre elas as causadas pela hemorragia subaracnóidea espontânea (HSAE. Com a finalidade de avaliar a relação entre alterações na DAVO2 com o quadro clínico e a evolução de pacientes com HSAE, devido à ruptura de aneurisma cerebral, este método foi utilizado em 30 pacientes portadores desta patologia, admitidos na Unidade de Neurocirurgia do HBDF. A HSAE foi confirmada por CT de crânio em 17 pacientes e por punção lombar em 13. Dezoito pacientes foram admitidos com Hunt & Hess (H&H I ou II, sete com H&H III e cinco com H&H IV ou V. A medida da DAVO2 baseou-se na equação de Fick e os resultados clínicos foram avaliados pela escala de seqüelas de Glasgow. Dezenove pacientes apresentaram DAVO2 normais (inicialmente e durante a evolução, sendo que três faleceram; cinco tiveram valores de DAVO2 sempre baixos e três faleceram; os restantes seis pacientes tiveram valores da DAVO2 sempre elevados e dois faleceram. Os pacientes com DAVO2 normais tiveram melhor evolução clínica e índice de mortalidade menor, quando comparados com os pacientes com valores anormais da DAVO2 (pThe arterious venous oxygen difference (AVDO2 due to the close relationship with cerebral metabolic rate of oxygen and cerebral blood flow shows metabolic alterations that occur in some pathological situations in the brain including subarachnoid haemorrhage. The AVDO2 was calculated by the Fick equation and the results evaluated by the Glasgow outcome scale. Measurements of arteriojugular oxygen difference were carried out in 30 patients with subarachnoid haemorrhage due to rupture of intracranial aneurysms, as an attempt to monitor the relationship between changes in AVDO2, clinical picture, and evolution of the patients. The subarachnoid haemorrhage was diagnosed by CT scan in

  18. Demand Uncertainty

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen

    This paper presents a model of trade that explains why firms wait to export and why many exporters fail. Firms face uncertain demands that are only realized after the firm enters the destination. The model retools the timing of uncertainty resolution found in productivity heterogeneity models...... the high rate of exit seen in the first years of exporting. Finally, when faced with multiple countries in which to export, some firms will choose to sequentially export in order to slowly learn more about its chances for success in untested markets....

  19. CEREBRAL PALSY AND MUSIC ACHIEVEMENT

    Directory of Open Access Journals (Sweden)

    Miodrag L. STOSHLJEVIKJ

    2008-12-01

    Full Text Available Pupils with cerebral palsy attend elementary education accordind to a regular and special teaching plan and program. Regular school curriculum was reformed in 1992, while special plan and program has not been changed and adapted according to pupil’s needs and capacities. Music is one of the best means of expressing oneself and plays a very important role in the development of every child, the child with cerebral palsy in particular.In order to test the possibility of pupils with cerebral palsy, with and without mental retardation, to apprehend the actual program content, we have conducted research on musical achievement of children with cerebral palsy. During 2007 a research was carried out, on the sample of 27 pupils with cerebral palsy and mild mental retardation who attended classes in the school “Miodrag Matikj”, and a sample of16 students with cerebral palsy without mental retardation who attended the school “Dr. Dragan Hercog” in Belgrade.Results of the research, as well as analysis of music curriculum content, indicated that the capacities of students with cerebral palsy to carry out the curriculum tasks require special approach and methodology. Therefore, we introduced some proposals to overcome the difficulties in fulfilling music curriculum demands of those pupils. We made special emphasis on the use of computer based Assistive technology which facilitates the whole process to a large extent.

  20. Observation of postoperative rehabilitation efficacy of hyperbaric oxygen on brain tumors, cerebral aneurysms%高压氧对脑肿瘤、脑动脉瘤术后康复疗效的观察

    Institute of Scientific and Technical Information of China (English)

    江坤

    2014-01-01

    Objective To investigate the clinical effect of hyperbaric oxygen (HBO) in the treatment of brain tumors and cerebral aneurysms. Methods 200 patients with brain tumors or cerebral aneurysms in our hospital from 2009 December to 2013 December were selected, they were divided into two groups according to the different treatments. 100 cases with brain tumors or cerebral aneurysms were as the observation group that treated by HBO. 100 cases with similar disease were as the control group that treated without HBO. The two groups were both given conventional drug treatment .Checked cerebral vasospasm (CVS) by head color Doppler ultrasound, evaluated clinical recovery by neurological function and activities of daily living assessment, the clinical efficacy were compared and analyzed. Results The NF score and Barthel score of the two groups had no significant difference before the treatment (P>0.05);the NF score and Barthel score of the two groups had significant difference after the treatment (P 0.05), Middle cerebral artery flow velocity and CVS of the two groups had significant difference after the treatment(P<0.05). Conclusion HBO comprehensive treatment effect is remarkable, it can reduce neurological deficits, improve the quality of patients' life, it should be introduced.%目的:探讨高压氧(HBO)治疗脑肿瘤、脑动脉瘤术后康复的临床疗效。方法选取我院2009年12月~2013年12月收治的脑肿瘤、脑动脉瘤术后患者200例,根据治疗方法不同分为两组,将100例HBO治疗的脑肿瘤、脑动脉瘤术后患者设为观察组,将病情相似未作HBO治疗的100例患者设为对照组,两组均常规药物治疗。采用头颅彩色多普勒超声检查患者脑血管痉挛(CVS)情况,并采用神经功能缺损评分和日常生活活动能力评定评判患者临床恢复情况,并对临床疗效进行对比分析。结果两组患者治疗前NF评分和Barthel评分比较差异无统计学意义(P>0.05

  1. 高压氧辅助药物治疗动脉粥样硬化脑血管痉挛随机对照研究%Effect of hyperbaric oxygen combined with drug on patients with atherosclerotic cerebral vasospasm

    Institute of Scientific and Technical Information of China (English)

    辜忠灵

    2014-01-01

    目的:分析高压氧辅助药物治疗动脉粥样硬化脑血管痉挛的效果。方法选择在本院接受住院治疗的动脉粥样硬化脑血管痉挛患者作为研究对象,分别给予单纯药物治疗及高压氧辅助药物治疗,比较有效率、血液学指标、基底动脉管径及NO、NOS、Ca2+含量等。结果观察组有效率(97.06%)、基底动脉管径[(4.98±1.35)mm]、NO [(59.43±11.48)μmol/L]、NOS[(98.43±14.38)kU/L]均明显高于对照组;胆固醇[(3.12±0.72)mmol/L]、甘油三酯[(1.27±0.41)mmol/L]、血小板计数[(112.74±13.36)×109/L]、血黏度[(1.21±0.37) mPa · s]、[Ca2+(17.07±1.65)g/μmol]明显低于对照组( P<0.05)。结论高压氧辅助药物可有效提高动脉粥样硬化脑血管痉挛患者的临床疗效,优化血液学指标,升高基底动脉管径、NO及NOS ,减少Ca2+含量,具有积极的临床意义。%Objective To analyze the efficacy of hyperbaric oxygen combined with drug on patients with atherosclerotic cerebral vasospasm. Methods Patients with atherosclerotic cerebral vasospasm admitted to our hospital were chosen as re-search subjects ,and divided into observation group and control group. The control group was given drug therapy alone and the observation group was given hyperbaric oxygen combined with drug therapy. The efficiency of treatment ,hematological index , and basilar artery diameter ,NO ,NOS ,Ca2+ level of the two groups were compared. Results The efficacy rate (97.06% ) ,bas-al artery diameter(4.98 ± 4.98) mm ,NO(59.43 ± 11.48)μmol/L ,NO (98.43 ± 14.38) kU/L of observation group were sig-nificantly higher than those of the control group ;Cholesterol(3.12 ± 0.72) mmol/L ,triglycerides(1.27 ± 0.41) mmol/L , platelet count(112.74 ± 13.36)109/L ,blood viscosity(1.21 ± 0.37 )mPa · s ,Ca2+ (17.07 ± 1.65) g/μmol were significantly lower than those of the control group(P<0.05).Conclusion Hyperbaric oxygen

  2. Oxygen consumption and blood flow coupling in human motor cortex during intense finger tapping

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Vang, Kim; Bergersen, Linda H

    2012-01-01

    Rates of cerebral blood flow (CBF) and glucose consumption (CMR(glc)) rise in cerebral cortex during continuous stimulation, while the oxygen-glucose index (OGI) declines as an index of mismatched coupling of oxygen consumption (cerebral metabolic rate of oxygen-CMRO(2)) to CBF and CMR...

  3. Vasoespasmo cerebral

    Directory of Open Access Journals (Sweden)

    Antonio A. F. de Salles

    1987-09-01

    Full Text Available Vasoespasmo cerebral ocorre em patologias como enxaqueca, hemorragia subaracnóidea, trauma de crânio, após isquemia e/ou hipoxia. A fisiopatologia do vasoespasmo cerebral nestas patologias não está completamente desvendada. Neste artigo são analisados os fatores neuroquímicos e morfológicos responsáveis pelo controle circulatório cerebral. As alterações circulatórias que seguem a hemorragia subaracnóidea são utilizadas como exemplo. Conclui-se que fatores bioquímicos, fisiológicos e morfológicos são responsáveis pelas manifestações vasculares que ocorrem após a hemorragia subaracnóidea. Alternativas de tratamento do vasoespasmo cerebral são discutidas.

  4. A comparative study of technologies for the continuous measurements of the biochemical demand for oxygen and toxicity of water; Estudio comparativo de tecnologias de medicion en continuo de la demanda bioquimica de oxigeno y de la toxicidad en aguas

    Energy Technology Data Exchange (ETDEWEB)

    Diez-Caballero Arnau, T.; Rodriguez Albalat, G.; Rosa de la Garcia, S.; Jimenez Bono, M.; Millan Navarro, C.; prats, R.; Serramia, A.; Miguel, S. de

    2002-07-01

    The Prevention and Integrated Control of Contamination Act (Ley de Prevencion y control Integrado de la Contaminacion) was passed by the Spanish parliament on 13 June. the basic purpose of this law is to prevent, reduce and control contamination of the atmosphere, water and soil caused by the most contaminating industrial activities. Public sector bodies and private companies in Spanish have been invited by the European Union to adopt new technologies in their production processes with a view to cutting down emissions, minimising or re-using waste, and pre-treating or purifying effluents. I t is therefore extremely appropriate to make available information on new tools of analysis that allow users to take preventive measures to reduce the impact their activity may have on the environment. A fundamental parameter in monitoring water is the Biological Demand for Oxygen (BOD). Various different chemical, physical and biological techniques have been developed to solve the problem of continuously monitoring the BOD and toxicity of water. This study carried out a comparative analysis of these techniques, describing the advantages and disadvantages of applying them to water quality control. At the present time it can be said that the BOD microbiosensor. Multisens 304 is the best available technology for monitoring this parameter. The articles tells us why. (Author) 8 refs.

  5. Cerebral Paragonimiasis.

    Science.gov (United States)

    Miyazaki, I

    1975-01-01

    The first case of cerebral paragonimiasis was reported by Otani in Japan in 1887. This was nine years after Kerbert's discovery of the fluke in the lungs of Bengal tigers and seven years after a human pulmonary infection by the fluke was demonstrated by Baelz and Manson. The first case was a 26-year-old man who had been suffering from cough and hemosputum for one year. The patient developed convulsive seizures with subsequent coma and died. The postmortem examination showed cystic lesions in the right frontal and occipital lobes. An adult fluke was found in the occipital lesion and another was seen in a gross specimen of normal brain tissue around the affected occipital lobe. Two years after Otani's discovery, at autopsy a 29-year-old man with a history of Jacksonian seizure was reported as having cerebral paragonimiasis. Some time later, however, it was confirmed that the case was actually cerebral schistosomiasis japonica. Subsequently, cases of cerebral paragonimiasis were reported. However, the majority of these cases were not confirmed histologically. It was pointed out that some of these early cases were probably not Paragonimus infection. After World War II, reviews as well as case reports were published. Recently, investigations have been reported from Korea, with a clinicla study on 62 cases of cerebral paragonimiasis seen at the Neurology Department of the National Medical Center, Seoul, between 1958 and 1964. In 1971 Higashi described a statistical study on 105 cases of cerebral paragonimiasis that had been treated surgically in Japan.

  6. The coupling of cerebral blood flow and oxygen metabolism with brain activation is similar for simple and complex stimuli in human primary visual cortex.

    Science.gov (United States)

    Griffeth, Valerie E M; Simon, Aaron B; Buxton, Richard B

    2015-01-01

    Quantitative functional MRI (fMRI) experiments to measure blood flow and oxygen metabolism coupling in the brain typically rely on simple repetitive stimuli. Here we compared such stimuli with a more naturalistic stimulus. Previous work on the primary visual cortex showed that direct attentional modulation evokes a blood flow (CBF) response with a relatively large oxygen metabolism (CMRO2) response in comparison to an unattended stimulus, which evokes a much smaller metabolic response relative to the flow response. We hypothesized that a similar effect would be associated with a more engaging stimulus, and tested this by measuring the primary human visual cortex response to two contrast levels of a radial flickering checkerboard in comparison to the response to free viewing of brief movie clips. We did not find a significant difference in the blood flow-metabolism coupling (n=%ΔCBF/%ΔCMRO2) between the movie stimulus and the flickering checkerboards employing two different analysis methods: a standard analysis using the Davis model and a new analysis using a heuristic model dependent only on measured quantities. This finding suggests that in the primary visual cortex a naturalistic stimulus (in comparison to a simple repetitive stimulus) is either not sufficient to provoke a change in flow-metabolism coupling by attentional modulation as hypothesized, that the experimental design disrupted the cognitive processes underlying the response to a more natural stimulus, or that the technique used is not sensitive enough to detect a small difference. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. A Bovine Hemoglobin-Based Oxygen Carrier as Pump Prime for Cardiopulmonary Bypass: Reduced Systemic Lactic Acidosis and Improved Cerebral Oxygen Metabolism During Low-flow in a Porcine Model

    Science.gov (United States)

    2010-11-10

    TNF-α changed significantly from baseline to completion. Mean creatine kinase was elevated at baseline due to the sample being collected after...NS NS CK, creatine kinase ; CKMB, creatine kinase MB; AST, aspartate aminotransferase; BUN, blood urea nitrogen; IL-6, interleukin 6; TNF-α, tumor...diffusion resistance , and facilitates oxygen delivery to tissue beds (1,2). HBOC-201 is a “high P50” HBOC: the P50 of HBOC-201 is 38 mm Hg compared to 27

  8. Cerebral Palsy (For Teens)

    Science.gov (United States)

    ... Right Sport for You Healthy School Lunch Planner Cerebral Palsy KidsHealth > For Teens > Cerebral Palsy Print A A ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

  9. 早期高压氧治疗对急性颅脑外伤患者失语症的疗效观察%Effects of early hyperbaric oxygen therapy on alogia in acute cerebral injury

    Institute of Scientific and Technical Information of China (English)

    林瑛; 李泉清; 刘代娣; 杨静; 张其清

    2009-01-01

    目的 研究早期高压氧(HBO)治疗对急性颅脑外伤患者失语症的疗效.方法 将2004年1月至2007年8月在我院住院的62例急性颅脑外伤患者分为HBO治疔组和常规治疗组,常规治疗组采用临床常规治疗,HBO治疗组在常规治疗的基础上,实施24~48次HBO治疗,并且在治疗结束后1年内每3个月进行1次随访.在治疗前、后分别采用西方失语成套测试法(western aphasia,WAB)检测并进行CT检查,对他们的语言功能和恢复情况进行评价和比较.结果 HBO治疗组显效率(83.8%)显著高于常规治疗组(54.8%),经x2检验P<0.05;CT检查证实患者病变部位阻塞的血管已经恢复冉通或已获得重建.结论 早期HBO治疗有利于促进或恢复患者的语言功能.%Objective To investigate the effects of early hyperbaric oxygen therapy on aphasia in acute cerebral injury. Methods Sixty-two patients with acute cerebral injury were admitted into the hospital from January 2004 to August 2007. They were randomly divided into the hyperbaric oxygen (HBO) group and the control group. The control group was administered with routine treatment other than HBO, while the HBO group was given 24-48 sessions of HBO treatment in addition to routine treatment. To know how they recovered, clinical follow-ups were made every 3 months, one year after the patients terminated treatment. The linguistic function of the patients was evaluated and compared by using Western Aphasia Battery (WAB) and CT before and after HBO therapy. Results Results showed that the HBO exposure group had obviously better results when it was compared with the control group ( 83. 8% : 54. 8% ). And test showed that P < 0, 05. CT examination demonstrated that the blocked vessels in the affected area were either recovered or repaired. Conclusions Early HBO therapy will help to improve or recover the linguistic function of patients with acute cerebral injury.

  10. Wearable wireless cerebral oximeter (Conference Presentation)

    Science.gov (United States)

    Zhang, Xin; Jiang, Tianzi

    2016-03-01

    Cerebral oximeters measure continuous cerebral oxygen saturation using near-infrared spectroscopy (NIRS) technology noninvasively. It has been involved into operating room setting to monitor oxygenation within patient's brain when surgeons are concerned that a patient's levels might drop. Recently, cerebral oxygen saturation has also been related with chronic cerebral vascular insufficiency (CCVI). Patients with CCVI would be benefited if there would be a wearable system to measure their cerebral oxygen saturation in need. However, there has yet to be a wearable wireless cerebral oximeter to measure the saturation in 24 hours. So we proposed to develop the wearable wireless cerebral oximeter. The mechanism of the system follows the NIRS technology. Emitted light at wavelengths of 740nm and 860nm are sent from the light source penetrating the skull and cerebrum, and the light detector(s) receives the light not absorbed during the light pathway through the skull and cerebrum. The amount of oxygen absorbed within the brain is the difference between the amount of light sent out and received by the probe, which can be used to calculate the percentage of oxygen saturation. In the system, it has one source and four detectors. The source, located in the middle of forehead, can emit two near infrared light, 740nm and 860nm. Two detectors are arranged in one side in 2 centimeters and 3 centimeters from the source. Their measurements are used to calculate the saturation in the cerebral cortex. The system has included the rechargeable lithium battery and Bluetooth smart wireless micro-computer unit.

  11. Effects of Yunnan Baiyao through inner layer of cerebral dura mater on cerebral perfusion and oxygen metabolism in rabbits with severe traumatic brain injury%硬脑膜夹层导入云南白药对兔重型颅脑创伤后脑灌注和氧代谢的影响

    Institute of Scientific and Technical Information of China (English)

    徐震; 吕晓皑; 尹利明; 竺国充; 张昕; 李徐; 陈祖鹏

    2012-01-01

    Objective: To explore the effects of Yunnan Baiyao through inner layer of cerebral dura mater on cerebral perfusion and oxygen metabolism in rabbits with severe traumatic brain injury. Methods: 40 New Zealand white rabbits were divided into cerebral dura mater Yunnan Baiyao group(A group), intravenous Mannitol group(B group), oral Yunnan Baiyao group (C group) and control group(D group). Record ICP, CPP and MABP. TCD measured cerebral blood flow volume. Monitor blood gas analysis in femora) artery and internal jugular venous bulb, accounting the CEO2 and D-values of glucose and lactic acid between artery and venous bulb. Results: From 12 to 36 hour after therapy: the ICP of A was highter than B, the CPP and CBFV were lower than B (P<0.05). At 48 hour: the ICP of A was highter than B and lower than C and D, the CPP was lower than B and highter than Cand D, while the CBFV of A was highter than C and D(P<0.05). From 60 to 96 hour: the ICP of A was lower than C and D, the CPP of A was highter than C and D, the CBFV of A was highter than B, C and D(P<0.05). From 36 to 96: The Glua-jv and CEO2 of A were highter than B, C and D, while the Lacjv-a was lower than B, C and D(P<0.05). Conclusion: Yunnan Baiyao through cerebral dura mater can reach effective treatment concentration in brain. By increasing the efficiency of oxygen metabolism of brain it can ameliorate brain cell hypoxia and energy metabolism handicap, adjust cerebral microcirculation, thus improves cytotoxic brain edema, decreases cerebral blood flow resistance, reduces ICP and increase the CPP and CBFV.%目的:探讨硬脑膜夹层应用云南白药对兔重型颅脑创伤后颅内压、脑血流量和脑代谢的影响.方法:将40只雄性新西兰大白兔分为硬脑膜夹层云南白药组(A组)、静脉甘露醇组(B组)、口服云南白药组(C组)和空白组(D组),制作重型颅脑创伤模型,行颅内压(ICP)监测,记录平均动脉压(MABP),计算脑灌注压(CPP),经颅多普勒(TCD)测定脑

  12. Effects of reactive oxygen species on metabolism monitored by longitudinal {sup 1}H single voxel MRS follow-up in patients with mitochondrial disease or cerebral tumors

    Energy Technology Data Exchange (ETDEWEB)

    Constans, J M; Collet, S; Hossu, G; Courtheoux, P [MRI Unit, Caen University Hospital, Caen, Normandy (France); Guillamo, J S; Lechapt-Zalcman, E; Valable, S [CERVOxy Group, CI-NAPS, UMR 6232 CI-NAPS, Cyceron, Caen, Normandy (France); Lacombe, S; Houee Levin, C [Paris-Sud 11 University-CNRS, Orsay (France); Gauduel, Y A [LOA, Ecole Polytechnique - ENSTA ParisTech, Palaiseau (France); Dou, W [Tsinghua University, Beijing (China); Ruan, S [CReSTIC EA 3804, IUT Troyes, Troyes (France); Barre, L [GDMTEP, Group CI-NAPS, UMR 6232 CI-NAPS, Cyceron, Caen (France); Rioult, F [CNRS UMR 6072, GREYC, Caen, Normandy (France); Derlon, J M [Neurosurgery and Neurology, Caen University Hospital, Caen, Normandy (France); Chapon, F [Pathology, Caen University Hospital, Caen, Normandy (France); Fong, V [Caen University (France); Kauffmann, F, E-mail: constans-jm@chu-caen.fr [Mathematics LMNO CNRS UMR 6139, Caen University, Caen, Normandy (France)

    2011-01-01

    Free radicals, or Reactive Oxygen Species (ROS), have an effect on energy and glycolytic metabolism, mitochondrial function, lipid metabolism, necrosis and apoptosis, cell proliferation, and infiltration. These changes could be monitored longitudinally (every 4 months over 6 years) in humans with glial brain tumors (low and high grade) after therapy, using conventional magnetic resonance imaging (MRI) and spectroscopy (MRS) and MR perfusion. Some examples of early clinical data from longitudinal follow-up monitoring in humans of energy and glycolytic metabolism, lipid metabolism, necrosis, proliferation, and infiltration measured by conventional MRI, MRS and perfusion, and positron emission tomography (PET) are shown in glial brain tumors after therapy. Despite the difficulty, the variability and unknown factors, these repeated measurements give us a better insight into the nature of the different processes, tumor progression and therapeutic response.

  13. Effects of sedation induced with dexmedetomidine versus propofol on intracranial pressure and cerebral oxygen metabolism in patients with permissive hypercapnia%右美托咪啶与异丙酚镇静下允许性高碳酸血症患者颅内压及脑氧代谢的比较

    Institute of Scientific and Technical Information of China (English)

    王丽萍; 陈国忠

    2011-01-01

    Objective To compare the effects of sedation induced with dexmedetomidine and propofol on intracranial pressure and cerebral oxygen metabolism in patients with permissive hypercapnia. Methods Twentyfour patients with acute respiratory distress syndrome (ARDS) were randomly divided into 2 groups ( n = 12 each) :dexmedetomidine group (group D) and propofol group (group P) . Their APACHE Ⅱ scores were 11-18. The patients were mechanically ventilated (VT 5-7 ml/kg, RR 12-17 bpm, PEEP 6-10 cm H2O, FiO2 40-60%). PaCO2 was maintained at 50-65 mm Hg. Radial artery was cannulated for direct BP monitoring and blood sampling. Right internal jugular vein was cannulated and the catheter was advanced cephalad until jugular bulb. Continuous infusion of dexmedetomidine was started at 0.5 μg· kg-1· h-1 and TCI of propofol was started at target plasma concentration (Cp) of 0.4 μg/ml. The infusion of both drugs was gradually increased until Ramsay score (1= fully awake, 6 =asleep, unresponsive to loud verbal stimulus) reached 3,4,5. Transcranial Doppler monitoring was used to determine cerebral blood flow velocity (CBFV), pulsatility index (PI) and resistance index (RI) before administration of dexmedetomidine and propofol (T0 ) and at 30 min after the 3 levels of sedation were reached (T1-3) . Meanwhile blood samples were taken from radial artery and jugular bulb for blood gas analyses. Cerebral O2 metabolic rate (CMRO2), cerebral A-V O2 content differences (Da-jvO2) and cerebral O2 extraction rate (CERO2) were calculated .ResultsCBFV, PI, RI and CMRO2 were significantly decreased at T1-3 as compared with the baseline values at T0 in both groups. CBFV was positively correlated with CMRO2 in both group D (r = 0.80) and group P ( r = 0.76) . CBFV, PI and RI were significantly lower at T1-3 in group D than in group P. There was no significant change in Da-jvO2 and CERO2 at T1-3 as compared with the baseline values at T0 in both groups. Conclusion At different sedation levels

  14. Application of extracorporeal membrane oxygenation to cardiopulmonary cerebral resuscitation%体外膜肺氧合在心肺脑复苏中的应用

    Institute of Scientific and Technical Information of China (English)

    蒋崇慧; 黄子通; 谢钢; 李斌飞; 宁晔; 吴美英; 郑伟华; 尹刚; 赵双彪

    2008-01-01

    Objective To investigate the effects and values of extracorporeal membrane oxygenation (EC-MO) used in patients after cardiac arrest. Method During five years period from June 2002 to June 2007,fifteen cases taken for cardiopulmonary resuscitation were treated by using ECMO in the emergency department and ICU. All the measures for disgnosis and treatment were observed to the guidelines for cardiopulmonary resuscitation and emergency cardiovasculat care set by the American Heart Association in 2005, and ECMO was applied in addition. The study was a self-comparison trial. The biomarkers including heart rate (HR), mean arterial pressure (MAP), central venous pressure( CVP) , arterial partial oxygen pressure (PaO2), arterial partial pressure of carbon dioxide ( PCQ2), oxygen saturation (SaO2), hydrogen power (PH), and concentration of lactic acid were taken and assayed before and 10 min, 1 h,6 h, 12 h, and 24 h after treatment. Differences between the results of measurements were analysed by t -test for matched pairs using SPSS version 10.0 software package. Neurological sequelae was also observed and described. Results Ten minutes after ECMO treatment, MAP rose dramatically (P 的标准诊治方案进行救治,同时行体外膜肺氧合(ECMO)治疗.采用治疗前后自身对照的方法,监测ECMO治疗前、ECMO治疗后10 min、1 h、6 h、12 h、24 h,患者的心率、平均动脉压、中心静脉压(eve);并抽取桡动脉血检测动脉血氧分压、二氧化碳分压、血氧饱和度、酸碱度、动脉血乳酸含量等指标;统计数据以((x)±s)表示,采用SPSS 10.0统计软件包进行t检验,以P<0.05为差异具有统计学意义;同时就患者的神经性后遗症进行了观察和描述.结果 平均动脉压在ECMO治疗后10min比ECMO治疗前明显升高(P<0.01),ECMO治疗后1 h比ECMO治疗后10 min有所升高(P<0.05);CVP在ECMO治疗后10 min比ECMO治疗前,ECMO治疗后1 h比ECMO治疗后10 min有所降低(P<0.05);经ECMO治疗后10

  15. Vasoespasmo cerebral

    OpenAIRE

    1987-01-01

    Vasoespasmo cerebral ocorre em patologias como enxaqueca, hemorragia subaracnóidea, trauma de crânio, após isquemia e/ou hipoxia. A fisiopatologia do vasoespasmo cerebral nestas patologias não está completamente desvendada. Neste artigo são analisados os fatores neuroquímicos e morfológicos responsáveis pelo controle circulatório cerebral. As alterações circulatórias que seguem a hemorragia subaracnóidea são utilizadas como exemplo. Conclui-se que fatores bioquímicos, fisiológicos e morfológi...

  16. Study on visible spectrophotometer and chemical oxygen demand detection system%可见分光光度计及化学需氧量检测系统的研究

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    阐述了可见分光光度计在化学需氧量(COD)检测方向的研究方案,给出了可见分光光度计光路和电路两部分的研究方法。仪器光路采用了对称切尔尼特纳分光结构,并采用全息平面衍射闪耀光栅作为分光元件,使得检测光在光谱能量和光谱分辨率上都得到了提高。电路方面采用高速度高精度对数放大器 log114,使得电路检测精度和响应速度得到了提高。通过对COD标准液的标定测量,并与 HACH-DR61000紫外可见分光光度计进行对比,证明仪器在COD检测方面的系统性能和准确性稳定可靠。%This article expounds the research of the spectrophotometer used in determined the chemical oxygen demand (COD),discusses the research method of the optical system and electronic system.Optical system using symmetrical Czerny Turner system,and use the holographic plane diffraction grating as light splitting element,which improves the spectral energy and spectral resolution.Electronic systems using the high speed high accuracy logarithmic amplifier log114,improves the detecting precision and response speed.Use the COD standard solution calibration Instrument, Compared with HACH-DR6000,that proved the COD detection system’s performance and accuracy are stable and reliable.

  17. Changes of regional cerebral blood oxygenation in recognizing Chinese characters in children with Chinese dyslexia%汉语阅读障碍儿童汉字识别过程中脑血氧的变化

    Institute of Scientific and Technical Information of China (English)

    宋然然; 吴汉荣

    2006-01-01

    化量明显高于对照组(0.073 0,-0.072 1,F=15.59,P<0.01).结论:汉字认知过程阅读障碍儿童左前额叶皮层虽然激活,但相对正常儿童,激活的程度和激活模式均有差异,提示特定脑区功能异常可能是阅读障碍发生的生物学基础.%BACKGROUND: Dyslexia is the most common in the study of learning disabilities, it can affect various aspects of children, including behaviors,cognition, emotion, social adaptation, etc., and seriously block their obtaining of knowledge and improvement of ability in children.OBJECTIVE: To study the changing law of regional cerebral blood oxygenation in children with Chinese dyslexia in the process of recognizing Chinese characters, and investigate the neurophysiological basis of dyslexia in children.DESIGN: A case-control study.SETTING: Department of Child and Adolescent Health and Maternal Care, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology.PARTICIPANTS: The study was carried out in Huazhong University of Science and Technology from June to September in 2003. Forty-five primary students of 8 to 12 years old, who were grade 3 to 5 in Wuhan city,were enrolled in this study, including 26 dyslexic children (dyslexia group)and 19 normal readers (control group). All the enrolled children were righthanded. Informed consents were obtained from all the participants and their parents (guardians) after explanation of aims and steps of this study.METHODS: The functional near-infrared imager (fNIRI) was applied to detect the changes of cerebral blood oxygenation in left prefrontal lobe of dyslexic children and normal children in the primary processing (viewing passively, reading aloud, producing an action word) and secondary processing of Chinese characters (outputting task, action words association) of Chinese characters.MAIN OUTCOME MEASURES: The changes of cerebral blood oxygenation in the primary processing and secondary processing of Chinese characters were observed in both

  18. Propofol prevents autophagic cell death following oxygen and glucose deprivation in PC12 cells and cerebral ischemia-reperfusion injury in rats.

    Directory of Open Access Journals (Sweden)

    Derong Cui

    Full Text Available BACKGROUND: Propofol exerts protective effects on neuronal cells, in part through the inhibition of programmed cell death. Autophagic cell death is a type of programmed cell death that plays elusive roles in controlling neuronal damage and metabolic homeostasis. We therefore studied whether propofol could attenuate the formation of autophagosomes, and if so, whether the inhibition of autophagic cell death mediates the neuroprotective effects observed with propofol. METHODOLOGY/PRINCIPAL FINDINGS: The cell model was established by depriving the cells of oxygen and glucose (OGD for 6 hours, and the rat model of ischemia was introduced by a transient two-vessel occlusion for 10 minutes. Transmission electron microscopy (TEM revealed that the formation of autophagosomes and autolysosomes in both neuronal PC12 cells and pyramidal rat hippocampal neurons after respective OGD and ischemia/reperfusion (I/R insults. A western blot analysis revealed that the autophagy-related proteins, such as microtubule-associated protein 1 light chain 3 (LC3-II, Beclin-1 and class III PI3K, were also increased accordingly, but cytoprotective Bcl-2 protein was decreased. The negative effects of OGD and I/R, including the formation of autophagosomes and autolysosomes, the increase in LC3-II, Beclin-1 and class III PI3K expression and the decline in Bcl-2 production were all inhibited by propofol and specific inhibitors of autophagy, such as 3-methyladenine (3-MA, LY294002 and Bafilomycin A1 (Baf,. Furthermore, in vitro OGD cultures and in vivo I/R rats showed an increase in cell survival following the administration of propofol, as assessed by an MTT assay or histochemical analyses. CONCLUSIONS/SIGNIFICANCE: Our data suggest that propofol can markedly attenuate autophagic processes via the decreased expression of autophagy-related proteins in vitro and in vivo. This inhibition improves cell survival, which provides a novel explanation for the pleiotropic effects of

  19. Cerebral hemodynamic changes of mild traumatic brain injury at the acute stage.

    Directory of Open Access Journals (Sweden)

    Hardik Doshi

    Full Text Available Mild traumatic brain injury (mTBI is a significant public health care burden in the United States. However, we lack a detailed understanding of the pathophysiology following mTBI and its relation to symptoms and recovery. With advanced magnetic resonance imaging (MRI, we can investigate brain perfusion and oxygenation in regions known to be implicated in symptoms, including cortical gray matter and subcortical structures. In this study, we assessed 14 mTBI patients and 18 controls with susceptibility weighted imaging and mapping (SWIM for blood oxygenation quantification. In addition to SWIM, 7 patients and 12 controls had cerebral perfusion measured with arterial spin labeling (ASL. We found increases in regional cerebral blood flow (CBF in the left striatum, and in frontal and occipital lobes in patients as compared to controls (p = 0.01, 0.03, 0.03 respectively. We also found decreases in venous susceptibility, indicating increases in venous oxygenation, in the left thalamostriate vein and right basal vein of Rosenthal (p = 0.04 in both. mTBI patients had significantly lower delayed recall scores on the standardized assessment of concussion, but neither susceptibility nor CBF measures were found to correlate with symptoms as assessed by neuropsychological testing. The increased CBF combined with increased venous oxygenation suggests an increase in cerebral blood flow that exceeds the oxygen demand of the tissue, in contrast to the regional hypoxia seen in more severe TBI. This may represent a neuroprotective response following mTBI, which warrants further investigation.

  20. Deletion of TRPC6 Attenuates NMDA Receptor-Mediated Ca2+ Entry and Ca2+-Induced Neurotoxicity Following Cerebral Ischemia and Oxygen-Glucose Deprivation

    Science.gov (United States)

    Chen, Jin; Li, Zhaozhong; Hatcher, Jeffery T.; Chen, Qing-Hui; Chen, Li; Wurster, Robert D.; Chan, Sic L.; Cheng, Zixi

    2017-01-01

    Transient receptor potential canonical 6 (TRPC6) channels are permeable to Na+ and Ca2+ and are widely expressed in the brain. In this study, the role of TRPC6 was investigated following ischemia/reperfusion (I/R) and oxygen-glucose deprivation (OGD). We found that TRPC6 expression was increased in wild-type (WT) mice cortical neurons following I/R and in primary neurons with OGD, and that deletion of TRPC6 reduced the I/R-induced brain infarct in mice and the OGD- /neurotoxin-induced neuronal death. Using live-cell imaging to examine intracellular Ca2+ levels ([Ca2+]i), we found that OGD induced a significant higher increase in glutamate-evoked Ca2+ influx compared to untreated control and such an increase was reduced by TRPC6 deletion. Enhancement of TRPC6 expression using AdCMV-TRPC6-GFP infection in WT neurons increased [Ca2+]i in response to glutamate application compared to AdCMV-GFP control. Inhibition of N-methyl-d-aspartic acid receptor (NMDAR) with MK801 decreased TRPC6-dependent increase of [Ca2+]i in TRPC6 infected cells, indicating that such a Ca2+ influx was NMDAR dependent. Furthermore, TRPC6-dependent Ca2+ influx was blunted by blockade of Na+ entry in TRPC6 infected cells. Finally, OGD-enhanced Ca2+ influx was reduced, but not completely blocked, in the presence of voltage-dependent Na+ channel blocker tetrodotoxin (TTX) and dl-α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) blocker CNQX. Altogether, we concluded that I/R-induced brain damage was, in part, due to upregulation of TRPC6 in cortical neurons. We postulate that overexpression of TRPC6 following I/R may induce neuronal death partially through TRPC6-dependent Na+ entry which activated NMDAR, thus leading to a damaging Ca2+ overload. These findings may provide a potential target for future intervention in stroke-induced brain damage.

  1. Cerebral hemodynamics: concepts of clinical importance

    Directory of Open Access Journals (Sweden)

    Edson Bor-Seng-Shu

    2012-05-01

    Full Text Available Cerebral hemodynamics and metabolism are frequently impaired in a wide range of neurological diseases, including traumatic brain injury and stroke, with several pathophysiological mechanisms of injury. The resultant uncoupling of cerebral blood flow and metabolism can trigger secondary brain lesions, particularly in early phases, consequently worsening the patient's outcome. Cerebral blood flow regulation is influenced by blood gas content, blood viscosity, body temperature, cardiac output, altitude, cerebrovascular autoregulation, and neurovascular coupling, mediated by chemical agents such as nitric oxide (NO, carbon monoxide (CO, eicosanoid products, oxygen-derived free radicals, endothelins, K+, H+, and adenosine. A better understanding of these factors is valuable for the management of neurocritical care patients. The assessment of both cerebral hemodynamics and metabolism in the acute phase of neurocritical care conditions may contribute to a more effective planning of therapeutic strategies for reducing secondary brain lesions. In this review, the authors have discussed concepts of cerebral hemodynamics, considering aspects of clinical importance.

  2. Rapid Determination of Biochemical Oxygen Demand(BOD) in Wastewater with Ferrocene (Fc) Grafted Mediator Microbial Sensor%接枝二茂铁介体微生物传感器对污水BOD的快速测定

    Institute of Scientific and Technical Information of China (English)

    胡磊; 李轶

    2012-01-01

    采用接枝二茂铁为介体的微生物传感器测量污水的BOD.将二茂铁(ferrocene,Fc)通过缩合反应接枝到大分子介孔材料SBA-15的表面用作微生物生化反应传递电子的介体,与活性污泥提取的微生物混合,并用聚乙烯醇(PVA)进行固定化,以此制备成微生物敏感膜,并与玻碳电极耦合,构建三电极传感系统,用于快速测量污水水样的BOD.结果表明,传感器的线性范围为2~300 mg/L,连续测量20个样品的精密度为4.2%,能连续工作35 d.并讨论了pH,温度和重金属对传感器响应的影响.通过对实际水样的测试表明,测得的BOD与BOD5的具有良好的相关性.%A novel biochemical oxygen demand(BOD) detecting method employing a ferrocene(Fc) grafted SBA-1S mediator immobilized in PVA matrix was developed. Fc was combined with SBA-15 via ion-association and the product was labeled as SBA-15-Fc, which was employed for a modified glassy carbon electrode. In a three-electrode system, a linear relationship between the anodic current responses and glucose/glutamate(GGA) concentration was 2~300 mg/L. Single sensor (measuring 20 samples) reproducibility were less than 4.2 %, and the sensor can works for 35 days continuously. The effects of pH, temperature and heavy metal on the BOD responses were studied. Comparaiion of detecting the BOD and BOD; of real samples showed a good correlation

  3. Microbial sensor for measurement of biochemical oxygen demand based on ferrocene-grafted mediator%基于接枝二茂铁介体的BOD微生物传感器

    Institute of Scientific and Technical Information of China (English)

    胡磊; 李轶

    2012-01-01

    开发出以接枝二茂铁为介体的微生物传感器测量BOD,将二茂铁(ferrocene,Fc)通过缩合反应接枝到大分子介孔材料SBA-15的表面,作为微生物生化反应传递电子的介体,与活性污泥微生物 混合固定化于聚乙烯醇(PVA)里,制备成微生物敏感膜,并与玻碳电极耦合,构建三电极传感系统,用于快速测量水样的BOD质量浓度.结果表明,传感器测量的质量浓度线性范围为2~ 300 mg/L,连续测量20个样品的精密度为4.2%,能连续工作35 d.讨论pH、温度和重金属对传感器响应的影响.实际水样的测试结果表明,由微生物传感器测得的BOD与BOD5的具有良好的相关度.%A novel microbial sensor using a ferrocene (Fc)-grafted SBA-15 mediator immobilized in a PVA matrix was developed for measurement of the biochemical oxygen demand (BOD). Fc was grafted onto the SBA-15 surface via ion-association and the product was labeled as SBA-15-Fc, and applied to a modified glassy carbon electrode for measuring BOD rapidly in the three-electrode system. The results showed a linear relationship between the anodic current responses and glucose/glutamate (GGA) concentration ranging from 2 mg/L to 300 mg/L. The reproducibility of a single sensor measuring 20 samples was less than 4.2%, and the sensor could continuously work for 35 days. The effects of pH, temperature, and heavy metal on the BOD response were studied. The detection results of real samples show that the BOD measured by the microbial sensor was in good correlation with that obtained with the BOD5 method.

  4. The energy demand of fast neuronal network oscillations: insights from brain slice preparations

    Directory of Open Access Journals (Sweden)

    Oliver eKann

    2012-01-01

    Full Text Available Fast neuronal network oscillations in the gamma range (30-100 Hz in the cerebral cortex have been implicated in higher cognitive functions such as sensual perception, working memory, and, perhaps, consciousness. However, little is known about the energy demand of gamma oscillations. This is mainly caused by technical limitations that are associated with simultaneous recordings of neuronal activity and energy metabolism in small neuronal networks and at the level of mitochondria in vivo. Thus recent studies have focused on brain slice preparations to address the energy demand of gamma oscillations in vitro. Here, reports will be summarized and discussed that combined electrophysiological recordings, oxygen sensor microelectrodes and live-cell fluorescence imaging in acutely prepared slices and organotypic slice cultures of the hippocampus from both, mouse and rat. These reports consistently show that gamma oscillations can be reliably induced in hippocampal slice preparations by different pharmacological tools. They suggest that gamma oscillations are associated with high energy demand, requiring both rapid adaptation of oxidative energy metabolism and sufficient supply with oxygen and nutrients. These findings might help to explain the exceptional vulnerability of higher cognitive functions during pathological processes of the brain, such as circulatory disturbances, genetic mitochondrial diseases, and neurodegeneration.

  5. Pulmonary hematological parameters, energetic flight demands and their correlation with oxygen diffusion capacity in the lungs Parámetros hematológicos pulmonares, demandas energéticas del vuelo y su correlación la capacidad de difusión de oxígeno en los pulmones

    OpenAIRE

    2007-01-01

    Hematological parameters of birds and mammals seem to respond to environmental requirements, such as hypoxia at high altitude and the energetic demands of locomotion and flight. In this work we hypothesize that lung capillary hematocrit and red blood size may be influenced by the energetic requirements of flight. Also, we propose that hematological parameters should vary together with the morphological parameters that determine oxygen diffusion capacity. We analyzed the red blood cell size an...

  6. Predictors of cerebral blood flow in patients with and without anemia.

    Science.gov (United States)

    Borzage, Matthew T; Bush, Adam M; Choi, Soyoung; Nederveen, Aart J; Václavů, Lena; Coates, Thomas D; Wood, John C

    2016-04-15

    Sickle cell disease (SCD) is the most common cause of stroke in childhood and results primarily from a mismatch of cerebral oxygen supply and demand rather than arterial obstruction. However, resting cerebral blood flow (CBF) has not been examined in the general African American population, in whom obesity, hypertension, cerebrovascular disease, and diminished cerebrovascular reserve capacity are common. To better understand the underlying physiological substrate upon which SCD is superimposed, we measured CBF in 32 young (age 28 ± 10 yr), asymptomatic African American subjects with and without sickle cell trait (n= 14). To characterize the effects of chronic anemia, in isolation of sickle hemoglobin we also studied a cohort of 13 subjects with thalassemia major (n= 10), dyserythropoetic anemia (n= 1), or spherocytosis (n= 2). Blood was analyzed for complete blood count, hemoglobin electrophoresis, cell free hemoglobin, and lactate dehydrogenase. Multivariate regression analysis showed that oxygen content was the strongest predictor of CBF (r(2)= 0.33,Psupply and demand. Copyright © 2016 the American Physiological Society.

  7. Aerobic training in children with cerebral palsy.

    Science.gov (United States)

    Nsenga, A L; Shephard, R J; Ahmaidi, S; Ahmadi, S

    2013-06-01

    Rehabilitation is a major goal for children with cerebral palsy, although the potential to enhance cardio-respiratory fitness in such individuals remains unclear. This study thus compared current cardio-respiratory status between children with cerebral palsy and able-bodied children, and examined the ability to enhance the cardio-respiratory fitness of children with cerebral palsy by cycle ergometer training. 10 children with cerebral palsy (Gross Motor Function Classification System levels I and II) participated in thrice-weekly 30 min cycle ergometer training sessions for 8 weeks (mean age: 14.2±1.9 yrs). 10 additional subjects with cerebral palsy (mean age: 14.2±1.8 yrs) and 10 able-bodied subjects (mean age: 14.1±2.1 yrs) served as controls, undertaking no training. All subjects undertook a progressive cycle ergometer test of cardio-respiratory fitness at the beginning and end of the 8-week period. Cardio-respiratory parameters [oxygen intake V˙O2), ventilation V ˙ E) and heart rate (HR)] during testing were measured by Cosmed K4 b gas analyzer. The children with cerebral palsy who engaged in aerobic training improved their peak oxygen consumption, heart rate and ventilation significantly (pchildren with cerebral palsy can benefit significantly from cardio-respiratory training, and such training should be included in rehabilitation programs.

  8. Cerebral blood flow in the neonate.

    Science.gov (United States)

    Vutskits, Laszlo

    2014-01-01

    Ensuring adequate oxygenation of the developing brain is the cornerstone of neonatal critical care. Despite decades of clinical research dedicated to this issue of paramount importance, our knowledge and understanding regarding the physiology and pathophysiology of neonatal cerebral blood flow are still rudimentary. This review primarily focuses on currently available human clinical and experimental data on cerebral blood flow and autoregulation in the preterm and term infant. Limitations of systemic blood pressure values as surrogates for monitoring adequate cerebral oxygen delivery are discussed. Particular emphasis is placed on the high interindividual variability in cerebral blood flow values, vasoreactivity, and autoregulatory thresholds making the applications of normative values highly questionable. Technical and ethical difficulties to conduct such trials leave us with a near complete lack of knowledge on how pharmacological and surgical interventions impact on cerebral autoregulation. The ensemble of these works argues for the necessity of highly individualized care by taking advantage of continuous bedside monitoring of cerebral circulation. They also point to the urgent need for further studies addressing the exciting but difficult issue of cerebral blood flow autoregulation in the neonate.

  9. [Should cerebral autoregulation be reassessed?

    DEFF Research Database (Denmark)

    Secher, Niels H.

    2009-01-01

    Maintained cardiac output (CO) and cerebral oxygenation (ScO2) are of importance for a reduction in perioperative complications. Normovolaemia is defined as a central blood volume that does not limit CO for the supine patient and is maintained by individualized goal directed fluid therapy. Thereb......, ScO2 is maintained even when the mean arterial pressure is pressure and it is recommended that ScO2 be monitored Udgivelsesdato: 2009/8/10...

  10. In vivo determination of cerebral hemodynamics and bioenergetics using spin-echo magnetic resonance imaging

    Science.gov (United States)

    Oja, Joni Marcus Eric

    1999-08-01

    It is well known that the transverse relaxation time, T 2, is dependent on the oxygenation state of blood. Two biophysical mechanisms have been proposed to explain this interdependency. In the diffusion model, oxygenation effects are accounted for by water diffusion through field gradients inside and outside, of the erythrocytes, whereas in the exchange model, the oxygenation effect is thought to be due to the exchange of water between erythrocytes and plasma. Careful in vitro studies with blood have shown that the exchange model fits best to the obtained data in preference to the diffusion model. During brain activation, local increases in blood flow exceed the oxygen demand, resulting in less deoxygenated blood in the capillary and venous compartments. Due to this, blood is less paramagnetic in these activated brain regions, lengthening T2, which in turn increases the signal intensities of the corresponding voxels in the MR image. Thus the measured blood-oxygen-level-dependent (BOLD) image contrast is a complex function of many physiological parameters, such as tissue morphometry, blood volume, blood flow, oxygenation and oxygen metabolism. All of these parameters contribute to the tissue magnetization influencing the transverse relaxation rate. Until now, no exact equations have been available which would relate these hemodynamic variables to a single MRI observable parameter, namely T 2, in a manner in which absolute units can be used. A fundamental theory was developed to explain measured spin-echo BOLD effects, and it was tested in animals and humans. In animal studies, blood oxygenation was altered by regulating arterial oxygen or carbon dioxide tension. This resulted in changes in blood volume, flow and blood magnetization, which in turn was reflected in T2. Using analytical expressions derived from the theory, the transverse relaxation rate was related to the oxygen saturation and extraction and quantification of microvascular cerebral blood volume was

  11. Cerebral oximetry in cardiac anesthesia

    Science.gov (United States)

    Vretzakis, George; Georgopoulou, Stauroula; Stamoulis, Konstantinos; Stamatiou, Georgia; Tsakiridis, Kosmas; Katsikogianis, Nikolaos; Kougioumtzi, Ioanna; Machairiotis, Nikolaos; Tsiouda, Theodora; Mpakas, Andreas; Beleveslis, Thomas; Koletas, Alexander; Siminelakis, Stavros N.; Zarogoulidis, Konstantinos

    2014-01-01

    Cerebral oximetry based on near-infrared spectroscopy (NIRS) is increasingly used during the perioperative period of cardiovascular operations. It is a noninvasive technology that can monitor the regional oxygen saturation of the frontal cortex. Current literature indicates that it can stratify patients preoperatively according their risk. Intraoperatively, it provides continuous information about brain oxygenation and allows the use of brain as sentinel organ indexing overall organ perfusion and injury. This review focuses on the clinical validity and applicability of this monitor for cardiac surgical patients. PMID:24672700

  12. Employees with Cerebral Palsy

    Science.gov (United States)

    ... Resources Home | Accommodation and Compliance Series: Employees with Cerebral Palsy (CP) By Eddie Whidden, MA Preface Introduction Information ... SOAR) at http://AskJAN.org/soar. Information about Cerebral Palsy (CP) What is CP? Cerebral palsy is a ...

  13. Cerebral blood flow and metabolism during isoflurane-induced hypotension in patients subjected to surgery for cerebral aneurysms

    DEFF Research Database (Denmark)

    Madsen, J B; Cold, G E; Hansen, E S;

    1987-01-01

    Cerebral blood flow and cerebral metabolic rate for oxygen were measured during isoflurane-induced hypotension in 10 patients subjected to craniotomy for clipping of a cerebral aneurysm. Flow and metabolism were measured 5-13 days after the subarachnoid haemorrhage by a modification of the classi......Cerebral blood flow and cerebral metabolic rate for oxygen were measured during isoflurane-induced hypotension in 10 patients subjected to craniotomy for clipping of a cerebral aneurysm. Flow and metabolism were measured 5-13 days after the subarachnoid haemorrhage by a modification......). Controlled hypotension to an average MAP of 50-55 mm Hg was induced by increasing the dose of isoflurane, and maintained at an inspired concentration of 2.2 +/- 0.2%. This resulted in a significant decrease in CMRO2 (to 1.73 +/- 0.16 ml/100 g min-1), while CBF was unchanged. After the clipping...

  14. 不同麻醉方法对重症颅脑损伤患者脑氧代谢的影响%Effect of different anesthesia methods on cerebral oxygen metabolism in patients with severe traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    邹斌

    2013-01-01

    Objective To investigate the effects of different anesthesia methods on cerebral oxygen metabolism in patients with severe traumatic brain injury.Methods Forty-five patients with severe traumatic brain injury from March 2011 to March 2013 were divided into propofol intravenous anesthesia group(group A),sevoflurane inhalation anesthesia group(group B) and intravenous inhalational anesthesia group (group C) by random digits table method with 15 cases each.The mean artery pressure (MAP),heart rate (HR) before anesthesia,immediately after tracheal intubation,2 minutes after intubation,10 min and 30 min after operation set and operation end were observed.The oxygen content of jugular venous (SjvO2),jugular bulb venous oxygen content (Da-jvO2) and cerebral metabolic rate for oxygen (CERO2) before anesthesia induction,immediately finish anesthesia induction,30 min and 1 h after operation set and operatin end were calculated.Results The SjvO2 values in three groups were at 30 min,1 h after operation set and operation end was higher than that before anesthesia induction (group A:0.662 ±0.077,0.689 ±0.067,0.685 ±0.066 vs.0.623 ±0.083; group B:0.661 ±0.074,0.681 ±0.072,0.661 ±0.069 vs.0.598 ±0.092; group C:0.715 ± 0.072,0.743 ± 0.070,0.713 ± 0.075 vs.0.631 ± 0.078),and there was significant difference (P < 0.05).The Da-jvO2 values,CERO2 at 30 min,1 h after operation set and operation end was lower than that before anesthesia induction in three groups [group A:Da-jvO2:(41.2 ± 6.3),(41.6 ± 8.1),(44.2 ± 6.3) ml/L vs.(49.2 ± 9.2) ml/L,CERO2:(33.0 ± 1.9)%,(32.7 ± 2.0)%,(32.3 ± 1.9)% vs.(36.0 ±2.3)%; group B:Da-jvO2:(41.8 ± 5.6),(40.2 ± 6.9),(41.8 ± 5.6) ml/L vs.(51.3 ± 8.6) ml/L,CERO2:(33.2 ±2.1)%,(33.0 ±2.6)%,(32.8 ±2.1)% vs.(34.7 ±3.1)% ; group C:Da-jvO2:(39.5 ±6.8),(38.7 ±7.0),(40.2 ±6.8) ml/L vs.(48.8 ±9.7) ml/L,CERO2:(31.8 ±2.9)%,(31.5 ±3.1)%,(32.9 ±2.3)% vs.(35.1 ± 2.9)%],and there was significant difference (P

  15. Effects of fluid restriction in combination with small dose of norepinephrine on cerebral oxygen metabolism in elderly patients undergoing gastrointestinal surgery%限制性输液复合小剂量去甲肾上腺素对胃肠道手术老年患者脑氧代谢的影响

    Institute of Scientific and Technical Information of China (English)

    邱晓东; 居斌华; 叶卉; 陆新健; 景亮; 汤文浩

    2015-01-01

    Objective To evaluate the effects of fluid restriction in combination with small dose of norepinephrine on cerebral oxygen metabolism in elderly patients undergoing gastrointestinal surgery.Methods Forty elderly patients of both sexes,aged 65-80 yr,with body mass index of 18-24 kg/m2,of ASA physical status Ⅰ or Ⅱ (NYHA Ⅰ or Ⅱ),with left ventricular ejection fraction≥50%,undergoing elective gastrointestinal surgery,were randomly divided into 2 groups (n =20 each) using a random number table:routine fluid administration group (group S) and restricted fluid administration + small dose of norepinephrine group (group RN).In group S,lactated Ringer's solution was given routinely,ephedrine 5 mg (per time) was injected intravenously,and MAP was maintained ≥ 65 mmHg during operation.In group RN,lactated Ringer's solution was infused intravenously at 5 ml · kg-1 · h-1 starting from 30 min before anesthesia,norepinephrine was infused intravenously at 0.01-0.03 μg · kg-1 · min-1 after induction of anesthesia,and MAP was maintained ≥ 65 mmHg.Intraoperative blood loss was replaced with the equal volume of 6% hydroxyethyl starch 130/0.4 sodium chloride injection in both groups.At 5 min before skin incision,1 and 2 h after skin incision and postanesthesia care unit discharge time,arterial and jugular bulb venous blood samples were obtained for blood gas analysis,and arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,cerebral oxygen extraction rate,and the ratio of cerebral blood flow to cerebral oxygen metabolic rate were calculated.Results There were no significant differences between the two groups in arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,cerebral oxygen extraction rate,and the ratio of cerebral blood flow to cerebral oxygen metabolic rate.Conclusion Fluid restriction combined with small dose of norepinephrine produces no effects on cerebral oxygen

  16. The effects of hyperventilation on the balance of cerebral oxygen supply and demand in patients with diabetes mellitus under general anesthesia%过度通气对糖尿病病人脑氧供需平衡的影响

    Institute of Scientific and Technical Information of China (English)

    林成新; 蒋宗滨; 何文政; 王喜军; 李英英; 胡振快

    2005-01-01

    目的研究过度通气对手术中糖尿病病人脑氧供需平衡的影响.方法择期全麻下行腹部手术病人30例,2型糖尿病组15例(DM组),非糖尿病组15例(对照组,C组),所有病人术中均随机分别进行三种不同模式机械通气:正常通气量通气[模式Ⅰ,动脉血二氧化碳分压(PaCO2)维持在35~40 mmHg]、轻度过度通气(模式Ⅱ,PaCO2维持在30~35 mmHg)、中度过度通气(模式Ⅲ,PaCO2维持在25~30 mmHg),检测两组病人在三种不同通气模式下动脉血氧饱和度(SaO2)、动脉血氧分压(PaO2)、动脉血乳酸盐浓度(ABL)、颈内静脉血氧饱和度(SjvO2)、颈内静脉血氧分压(PjvO2)和颈内静脉血乳酸盐浓度(JVBL),并计算病人在不同通气模式下动脉血氧含量(CaO2)、颈内静脉血氧含量(CjvO2)、氧摄取率(CERO2)和颈内静脉与桡动脉血乳酸差(DLA-V).结果两组病人CjvO2和SjvO2在以模式Ⅲ通气时均明显低于以模式Ⅰ通气,CERO2在模式Ⅲ通气时明显高于以模式Ⅰ通气.DM组病人JVBL和DLA-V在模式Ⅲ通气时均明显高于以模式Ⅰ通气.中度过度通气时,DM组病人DLA-V高于C组.结论中度过度通气可影响2型糖尿病病人脑氧供需平衡,导致大脑组织乏氧代谢增加.

  17. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sørensen, Simon; Pellicer, Adelina; Alderliesten, Thomas

    2015-01-01

    in eight European countries. PARTICIPANTS: 166 extremely preterm infants born before 28 weeks of gestation: 86 were randomised to cerebral NIRS monitoring and 80 to blinded NIRS monitoring. The only exclusion criterion was a decision not to provide life support. INTERVENTIONS: Monitoring of cerebral...... oxygenation using NIRS in combination with a dedicated treatment guideline during the first 72 hours of life (experimental) compared with blinded NIRS oxygenation monitoring with standard care (control). MAIN OUTCOME MEASURES: The primary outcome measure was the time spent outside the target range of 55......-85% for cerebral oxygenation multiplied by the mean absolute deviation, expressed in %hours (burden of hypoxia and hyperoxia). One hour with an oxygenation of 50% gives 5%hours of hypoxia. Secondary outcomes were all cause mortality at term equivalent age and a brain injury score assessed by cerebral...

  18. Cerebral autoregulation in the preterm newborn using near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Eriksen, Vibeke R; Hahn, Gitte H; Greisen, Gorm

    2015-01-01

    The aim was to compare two conventional methods used to describe cerebral autoregulation (CA): frequency-domain analysis and time-domain analysis. We measured cerebral oxygenation (as a surrogate for cerebral blood flow) and mean arterial blood pressure (MAP) in 60 preterm infants. In the frequency...

  19. Cerebral Palsy: General Information. Fact Sheet Number 2 = La Paralisis Cerebral: Informacion General. Fact Sheet Number 18.

    Science.gov (United States)

    Interstate Research Associates, McLean, VA.

    This fact sheet on cerebral palsy is offered in both English and Spanish. First, it provides a definition and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy: spastic, athetoid,…

  20. Cerebral Palsy: General Information. Fact Sheet Number 2 = La Paralisis Cerebral: Informacion General. Fact Sheet Number 18.

    Science.gov (United States)

    Interstate Research Associates, McLean, VA.

    This fact sheet on cerebral palsy is offered in both English and Spanish. First, it provides a definition and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy: spastic, athetoid,…

  1. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF......, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non...

  2. Demand Forecasting Errors

    OpenAIRE

    Mackie, Peter; Nellthorp, John; Laird, James

    2005-01-01

    Demand forecasts form a key input to the economic appraisal. As such any errors present within the demand forecasts will undermine the reliability of the economic appraisal. The minimization of demand forecasting errors is therefore important in the delivery of a robust appraisal. This issue is addressed in this note by introducing the key issues, and error types present within demand fore...

  3. Distraction decreases prefrontal oxygenation: A NIRS study.

    Science.gov (United States)

    Ozawa, Sachiyo; Hiraki, Kazuo

    2017-04-01

    When near-infrared spectroscopy (NIRS) is used to measure emotion-related cerebral blood flow (CBF) changes in the prefrontal cortex regions, the functional distinction of CBF changes is often difficult because NIRS is unable to measure neural activity in deeper brain regions that play major roles in emotional processing. The CBF changes could represent cognitive control of emotion and emotional responses to emotional materials. Supposing that emotion-related CBF changes in the prefrontal cortex regions during distraction are emotional responses, we examined whether oxygenated hemoglobin (oxyHb) decreases. Attention-demanding tasks cause blood flow decreases, and we thus compared the effects of visually paced tapping with different tempos, on distraction. The results showed that the oxyHb level induced by emotional stimulation decreased with fast-tempo tapping significantly more than slow-tempo tapping in ventral medial prefrontal cortex regions. Moreover, a Global-Local task following tapping showed significantly greater local-minus-global response time (RT) difference scores in the fast- and mid-tempo condition compared with those in the slow-tempo, suggesting an increased attentional focus, and decreased negative emotion. The overall findings indicate that oxyHb changes in a relatively long distraction task, as measured by NIRS, are associated with emotional responses, and oxyHb can be decreased by successfully performing attention-demanding distraction tasks.

  4. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb oxygen from the air you breathe. But some conditions ...

  5. Mitochondrial Targeted Antioxidant in Cerebral Ischemia.

    Science.gov (United States)

    Ahmed, Ejaz; Donovan, Tucker; Yujiao, Lu; Zhang, Quanguang

    There has been much evidence suggesting that reactive oxygen species (ROS) generated in mitochondria during cerebral ischemia play a major role in programming the senescence of organism. Antioxidants dealing with mitochondria slow down the appearance and progression of symptoms in cerebral ischemia and increase the life span of organisms. The mechanisms of mitochondrial targeted antioxidants, such as SKQ1, Coenzyme Q10, MitoQ, and Methylene blue, include increasing adenosine triphosphate (ATP) production, decreasing production of ROS and increasing antioxidant defenses, providing benefits in neuroprotection following cerebral ischemia. A number of studies have shown the neuroprotective role of these mitochondrial targeted antioxidants in cerebral ischemia. Here in this short review we have compiled the literature supporting consequences of mitochondrial dysfunction, and the protective role of mitochondrial targeted antioxidants.

  6. Brain oxygen saturation assessment in neonates using T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy.

    Science.gov (United States)

    Alderliesten, Thomas; De Vis, Jill B; Lemmers, Petra Ma; Hendrikse, Jeroen; Groenendaal, Floris; van Bel, Frank; Benders, Manon Jnl; Petersen, Esben T

    2017-03-01

    Although near-infrared spectroscopy is increasingly being used to monitor cerebral oxygenation in neonates, it has a limited penetration depth. The T2-prepared Blood Imaging of Oxygen Saturation (T2-BIOS) magnetic resonance sequence provides an oxygen saturation estimate on a voxel-by-voxel basis, without needing a respiratory calibration experiment. In 15 neonates, oxygen saturation measured by T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy were compared. In addition, these measures were compared to cerebral blood flow and venous oxygen saturation in the sagittal sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy ( R(2 )= 0.64, p infrared spectroscopy oxygen saturation, and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus ( R(2 )= 0.71, 0.50, 0.65; p infrared spectroscopy and T2-prepared blood imaging of oxygen saturation, confirming the validity of using of these techniques for determining cerebral oxygenation.

  7. Changes in cerebral oxidative metabolism during neonatal seizures following hypoxic ischemic brain injury

    Directory of Open Access Journals (Sweden)

    Subhabrata Mitra

    2016-08-01

    Full Text Available Seizures are common following hypoxic ischemic brain injury in newborn infants. Prolonged or recurrent seizures have been shown to exacerbate neuronal damage in the developing brain, however the precise mechanism is not fully understood. Cytochrome-c-oxidase is responsible for more than 90% of ATP production inside mitochondria. Using a novel broadband near-infrared spectroscopy system we measured the concentration changes in the oxidation state of cerebral cytochrome-c-oxidase (Δ[oxCCO] and hemodynamics during recurrent neonatal seizures following hypoxic ischemic encephalopathy in a newborn infant. A rapid increase in Δ[oxCCO] was noted at the onset of seizures along with a rise in the baseline of amplitude integrated electro-encephalogram (aEEG. Cerebral oxygenation and cerebral blood volume fell just prior to the seizure onset but recovered rapidly during seizures. Δ[oxCCO] during seizures correlated with changes in mean EEG voltage indicating an increase in neuronal activation and energy demand. The progressive decline in the Δ[oxCCO] baseline during seizures suggests a progressive decrease of mitochondrial oxidative metabolism.

  8. The Clinical Study on Relation between Regional Cerebral Oxygen Saturation and Postoperative Delirium in Patients during Cardiopulmonary Bypass%体外循环术中局部脑氧饱和度与术后谵妄的关系

    Institute of Scientific and Technical Information of China (English)

    刘威; 齐娟; 于荣国; 姚祖武; 龚书榕; 顾恩郁

    2011-01-01

    Objective To study the relation between regional cerebral oxygen saturation (rScO2)and postoperative delirium in patients underwent cardiopulmonary bypass (CPB) of cardiac surgery.Methods Twenty-eight patients underwent elective cardiac surgery were enrolled in the study. Postoperative delirium was assessed by the CAM-ICU everyday during 7 days after operation. All of the patients were divided into two groups (delirium group and non-delirium group) based on the postoperative delirium. The rScO2 of all patients was monitored during operation. The value of the mean rScO2 in the 7 periods (preoperatiion, preinducement, from inducement to the beginning of CPB, from the beginning of CPB to the end of nose temperature cooling, from the end of nose temperature cooling to the beginning of warming, from the beginning of warming to the end of CPB, the 30 minutes after CPB) during the operation period were calculated. The area under the curve of the rScO2 was calculated. Results The AUC-rScO2 of the patients in delirium group was significantly larger than the non-delirium group (P<0.05).Conclusions The low rScO2 increases the postoperative delirium in patients who underwent cardiopulmonary bypass of cardiac surgery. Hence we should monitor the rScO2 during operation.%目的 探讨体外循环(CPB)心血管外科手术期间患者脑氧代谢与术后谵妄的关系.方法 收集择期行CPB下心内直视手术患者28例,术后7 d内,每日以ICU精神错乱评估量表(CAM-ICU)评估患者的精神状态,以是否发生谵妄分为谵妄组和非谵妄组.2组术中均以近红外光谱仪动态监测监测局部脑氧饱和度(rScO2),计算围手术期中7个时段(术前、诱导前、诱导至CPB前、CPB开始至鼻咽温降温末、鼻咽温降温末至复温初、复温初至CPB结束、CPB结束后30 min)rScO2均值;计算rScO2曲线下面积(AUC-rScO2).结果 谵妄组AUC-rScO2较非谵妄组增大(P<0.05).结论 心血管外科手术CPB期间患者出现低rScO2

  9. Physical demands during folk dancing.

    Science.gov (United States)

    Wigaeus, E; Kilbom, A

    1980-01-01

    This investigation was undertaken to evaluate the aerobic demands during one of the most popular and demanding Swedish folk dances the "hambo". Six men and six women, ranging in age from 22 to 32, participated. Their physical work capacity was investigated on a bicycle ergometer and a treadmill, using two to three submaximal and one maximal loads. All subjects were moderately well-trained and their average maximal oxygen uptake on the treadmill were 2.5 and 3.7 l/min (42.8 and 53.2 ml/kg . min-1) for women and men, respectively. When dancing the "hambo" the heart rate was telemetered, and the Douglas bag technique was used for measurements of pulmonary ventilation and oxygen uptake. The physical demand during "hambo" dancing was high in all subjects. Oxygen uptake was 38.5 and 37.3 ml/kg . min-1 and heart rate 179 and 172 in women and men, respectively. Women used 90% and men 70% of their maximal aerobic power obtained on the treadmill. The pulmonary ventilation and respiratory quotient of the female subjects were lower when dancing as compared to running, possibly because of voluntary restriction of the movements of the thoracic cage. Some popular Scandinavian folk dances are performed at a speed and with an activity pattern resembling the "hambo", while others are performed at a slower pace. The exercise intensity used in "hambo" is more than sufficient to induce training effects in the average individual provided that the dancing is performed at the frequency and for length of time usually recommended for physical training. For older or less fit people dances with a slow pace can be used for training purposes.

  10. Modelación numérica de la hidrodinámica, del oxígeno disuelto y la demanda bioquímica de oxígeno en sistemas con vegetación Numerical modeling of hydrodynamics, dissolved oxygen and biochemical oxygen demand in systems with vegetation

    Directory of Open Access Journals (Sweden)

    Ricardo González-López

    2011-08-01

    Full Text Available El presente trabajo trata sobre la implementación de un modelo numérico para simular la hidrodinámica y el transporte de contaminantes en sistemas donde existe vegetación, tanto sumergida como emergente. Dicho modelo se basa en las ecuaciones de aguas someras para el cálculo de las velocidades del flujo, haciendo énfasis en la evaluación del esfuerzo cortante de arrastre de las plantas y en la turbulencia; así como en la ecuación de advección-difusión-reacción para la simulación del transporte de sustancias disueltas. En este trabajo se presenta el cálculo del transporte de la Demanda Bioquímica de Oxígeno y del Oxígeno Disuelto. El objetivo principal es reproducir las funciones de filtrado de contaminación y reaereación que cumplen las plantas en cuerpos de agua, como los humedales. En los resultados obtenidos del campo de velocidades se aprecia el cambio de comportamiento por la restricción al flujo que impone la vegetación. Las concentraciones de DBO y OD varían debido al tiempo de residencia y a la reaereación producida por el intercambio atmosférico y la respiración de las plantas. Se concluye que el modelo representa de manera óptima el comportamiento del transporte de sustancias disueltas en flujos con presencia de vegetación y que se puede aplicar a la gran variedad de ecosistemas, siendo capaz de predecir la ruta y destino de la contaminación.This work deals with the implementation of a numerical model to simulate hydrodynamics and transport of pollutants in flows where submerged vegetation is present. The model is based on the Shallow-Water Equations to calculate the mean velocities, emphasizing calculations of the shear stress produced by both the vegetation and turbulence. The Advection-Diffusion-Reaction Equation is used to calculate the transport of the Biochemical Oxygen Demand and the Dissolved Oxygen. The main objective is to simulate the transport of these substances and the pollution filtering and

  11. Advanced cerebral monitoring in neurocritical care

    Directory of Open Access Journals (Sweden)

    Barazangi Nobl

    2008-01-01

    Full Text Available New cerebral monitoring techniques allow direct measurement of brain oxygenation and metabolism. Investigation using these new tools has provided additional insight into the understanding of the pathophysiology of acute brain injury and suggested new ways to guide management of secondary brain injury. Studies of focal brain tissue oxygen monitoring have suggested ischemic thresholds in focal regions of brain injury and demonstrated the interrelationship between brain tissue oxygen tension (P bt O 2 and other cerebral physiologic and metabolic parameters. Jugular venous oxygen saturation (SjVO 2 monitoring may evaluate global brain oxygen delivery and consumption, providing thresholds for detecting brain hypoperfusion and hyperperfusion. Furthermore, critically low values of P bt O 2 and SjVO 2 have also been predictive of mortality and worsened functional outcome, especially after head trauma. Cerebral microdialysis measures the concentrations of extracellular metabolites which may be relevant to cerebral metabolism or ischemia in focal areas of injury. Cerebral blood flow may be measured in the neurointensive care unit using continuous methods such as thermal diffusion and laser Doppler flowmetry. Initial studies have also attempted to correlate findings from advanced neuromonitoring with neuroimaging using dynamic perfusion computed tomography, positron emission tomography, and Xenon computed tomography. Additionally, new methods of data acquisition, storage, and analysis are being developed to address the increasing burden of patient data from neuromonitoring. Advanced informatics techniques such as hierarchical data clustering, generalized linear models, and heat map dendrograms are now being applied to multivariable patient data in order to better develop physiologic patient profiles to improve diagnosis and treatment.

  12. United Cerebral Palsy

    Science.gov (United States)

    ... be sure to follow us on Twitter . United Cerebral Palsy UCP educates, advocates and provides support services to ... Partners Merz Logo Sprint Relay Copyright © 2015 United Cerebral Palsy 1825 K Street NW Suite 600 Washington, DC ...

  13. Employees with Cerebral Palsy

    Science.gov (United States)

    ... problems in the muscles or nerves. Instead, faulty development or damage to motor areas in the brain disrupt the brain's ability to adequately control movement and posture (United Cerebral Palsy, 2010). "Cerebral" refers to the ...

  14. Blood oxygenation level dependent effect of cerebral ischemic penumbra in monkey reversible middle cerebral artery occlusion model%猴可复性大脑中动脉闭塞模型脑缺血半暗带的血氧水平依赖效应

    Institute of Scientific and Technical Information of China (English)

    张敬; 陈英敏; 张云亭

    2010-01-01

    Objective To investigate the value of blood oxygenation level dependent (BOLD) MRI in detecting monkey cerebral ischemic penumbra (IP). Methods Six monkeys were used to make reversible middle cerebral artery occlusion (MCAO) model by an interventional microcatheter method. MR DWI, PWI mean transit time (MTT), T_2WI and quantitative T_2 map, T_2~* map were performed at MCAO (0 h) and 1,3,6,12,24,48 h after reperfusion. Reversible transverse relaxation rate (R_2') BOLD imaging was calculated using quantitative T_2 and T_2~* maps. Lesion volume percentage (lesion volume/bilateral hemispheres volume) were measured on 0 h DWI,48 h T_2WI and TTC staining. Ischemic area was subdivided into infracted core (high signal area on both 0 h DWI and 48 h T_2 WI), IP (high signal on 0 h DWI, iso on 48 h T_2 WI) and oligemia (0 h delayed MTT, iso signal on both 0 h DWI and 48 h T_2 WI). Relative R_2' (rR_2') was calculated to get ratio between the lesion and mirror area in contralateral healthyhemisphere. Paired t test and correlation analysis were used for comparison of lesion volume percentage. rR_2' values at each time point were compared by ANOVA. Results Reversible MCAO models were made successfully in 4 of 6 monkeys. Lesion volume porcentage on 48 h T_2 WI was reduced compared to that on Oh DWI [ (8.16±0.55)% vs (11.37±1.41)% ,t=6.472,P0.05], which showed significant positive correlation (r=0.98, P0.05),两者呈明显正相关(r=0.98,P<0.05).梗死核心、IP、低灌注区rR_2'在各时间点差异均有统计学意义,梗死核心低于IP,IP低于低灌注区(P<0.05),三者rR_2'值:0 h时分别为1.129±0.108、1.329±0.081、1.584±0.103(F=36.19,P<0.05).1 h分别为0.668±0.082、1.237±0.072、1.435±0.066(F=134.09,P<0.05).3 h分别为0.536±0.075、1.453±0.081、1.770±0.141(F=256.30,P<0.05).6 h分别为0.259±0.050、2.435±0.131、2.957±0.177(F=803.25,P<0.05).12 h分别为0.385±0.054、2.447±0.148、3.254±0.184(F=743.74,P<0.05).24 h分别为0.083±0.026、1

  15. Effect of hyperbaric oxygen preconditioning on expression of neuroplasticity after acute global cerebral ischemia-reperfusion in aged rats%高压氧预处理对老龄大鼠全脑缺血再灌注损伤后神经可塑性的影响

    Institute of Scientific and Technical Information of China (English)

    邹磊; 刘丹彦; 殷薇; 宋云

    2014-01-01

    Objective To investigate the effect of hyperbaric oxygen preconditioning (HOP)on expression of Nogo mRNA,No-go-A and Ng R protein in the cerebral cortex after acute global cerebral ischemia-reperfusion (I/R)in aged rats and to study its mechanism affecting neuroplasticity.Methods Forty-two aged male SD rats were randomly divided into 4 groups:control group (C group,n=6),hyperbaric oxygen group (H group,n=12),cerebral I/R injury group (I/R group,n=12)and HOP group (n=12). The H group and the HOP group were placed in the hyperbaric oxygen cabin for 1 h per day with a oxygen pressure of 0.2 Mpa for successive 5 d,at 24 h after last time of hyperbaric oxygen preconditioning the I/R group and the HOP group adopted the modified Pulsinelli vessel occlusion method for preparing the rat I/R injury model,with global cerebral ischemia for 10 min and reperfusion for 24 h,each 6 rats were randomly taken from the the H group,I/R group and HOP group and their heads were cut off for taking the brain and isolating the cerebral cortex.The real time fluorescence quantification PCR was adopted to detect the expression level of Nogo mRNA and the Nogo-A protein level was detected by Western blot.The rats in various groups were performed the T1 WI and T2WI scanning in the transection position and the coronal positions.Results There were no obvious ischemic brain infarction in the normal control group and the H group,the arc-shaped bilateral cortex ischemic infarct area was clearly seen in the ischemic group,the ischemic infarct area was also seen in the HOP ischemia group,but its area was smaller than which in the ischemic group.Compared with the C group,the expression of Nogo mRNA and the Nogo-A protein in the HOP group was up-regulated(P<0.05);compared with the I/R group,the expression of Nogo mRNA and the Nogo-A protein was down-regulated(P<0.05). Conclusion HOP increases the neuroplasticity and can reduce the cerebral ischemic infarction area in the exceed acute stage of rat acute

  16. RELATIONS OF THE CEREBRAL OXYGEN METABOLISM AND THE COGNITIVE FUNCTION AFTER COMBINED DEXMEDETOMIDINE ANESTHESIA OPERATION IN ELDERLY PATIENTS%右美托咪定联合全麻下老年患者术后认知功能与脑氧代谢的关系

    Institute of Scientific and Technical Information of China (English)

    吕安庆; 陈文迪

    2012-01-01

    目的 探讨右美托咪定联合全麻下老年患者术后认知功能与脑氧代谢的关系.方法 选取2009年12月-2011年6月期间在全身麻醉下行手术的老年患者100例,美国麻醉医师协会分级Ⅰ~Ⅲ级.随机分为2组,治疗组和对照组,各50例,采用简易智力状态检查表(mini-mental state examination,MMSE)对比评估2组患者术后6h,1、3d的认知功能.2组于麻醉诱导后即刻(T0 )、麻醉后60min(T1) 和麻醉恢复时(T2) 同步采集桡动脉和颈内静脉球部血样行血气分析,根据血红蛋白(hemoglobin,Hb)、动脉血氧饱和度(arterial oxygen saturation,SaO2)、颈内静脉血氧饱和度(jugular venous oxygen saturation,SjvO2)、动脉血氧分压(arterial partial prussure of oxygen,PaO2) 和颈内静脉血氧分压(jugular venous oxygen partial pressure,PjvO2),计算脑血流量/脑氧代谢率比值(cerebral blood flow to cerebral metabolic rate for oxygen,CBF/CMRO2).结果 手术后6h、1d各组MMSE评分均有不同程度的降低(P<0.05);手术后6h、1d A组MMSE评分明显低于B组(P<0.05);A组T0和T1时,CBF/CMR02异常发生率明显降低,差异有统计学意义(P<0.05); Logistic逐步回归分析显示T1时CBF/CMRO2异常与老年患者术后认知功能障碍的发生有关(β=3.413,P<0.05).结论 全麻下老年患者脑氧代谢异常可能是认知功能障碍的诱导原因之一,右美托咪定可能通过调节脑氧代谢功能来改善术后认知功能.%Objective To investigate the relations of the cerebral oxygen metabolism and the cognitive function after combined dexmedetomidine anesthesia operation in elderly patients. Methods One hundred patients aged over 60 years old were randomly divided into two groups: treatment group ( n = 50 ) and control group ( n = 50 ). A battery of mini - mental state examination ( MMSE ) and neuropsychological tests were administered 6 hours, 1 day and 7 days after surgery. Blood samples were taken from artery and internal jugular

  17. Cerebral Palsy (For Kids)

    Science.gov (United States)

    ... CPR: A Real Lifesaver Kids Talk About: Coaches Cerebral Palsy KidsHealth > For Kids > Cerebral Palsy Print A A A What's in this article? ... the first word you spoke? For kids with cerebral palsy, called CP for short, taking a first step ...

  18. Cerebral microcirculation during experimental normovolaemic anaemia

    Directory of Open Access Journals (Sweden)

    Judith eBellapart

    2016-02-01

    Full Text Available Anaemia is accepted amongst critically ill patients as an alternative to elective blood transfusion. This practice has been extrapolated to head injury patients with only one study comparing the effects of mild anaemia on neurological outcome. There are no studies quantifying microcirculation during anaemia. Experimental studies suggest that anaemia leads to cerebral hypoxia and increased rates of infarction, but the lack of clinical equipoise when testing the cerebral effects of transfusion amongst critically injured patients, supports the need of experimental studies. The aim of this study was to quantify cerebral microcirculation and the potential presence of axonal damage in an experimental model exposed to normovolaemic anaemia, with the intention of describing possible limitations within management practices in critically ill patients. Under non-recovered anaesthesia, six Merino sheep were instrumented using an intracardiac transeptal catheter to inject coded microspheres into the left atrium to ensure systemic and non-chaotic distribution. Cytometric analyses quantified cerebral microcirculation at specific regions of the brain. Amyloid precursor protein staining was used as an indicator of axonal damage. Animals were exposed to normovolaemic anaemia by blood extractions from the indwelling arterial catheter with simultaneous fluid replacement through a venous central catheter. Simultaneous data recording from cerebral tissue oxygenation, intracranial pressure and cardiac output was monitored. A regression model was used to examine the effects of anaemia on microcirculation with a mixed model to control for repeated measures. Homogeneous and normal cerebral microcirculation with no evidence of axonal damage was present in all cerebral regions, with no temporal variability, concluding that acute normovolaemic anaemia does not result in short term effects on cerebral microcirculation in the ovine brain.

  19. Ethanol Demand in United States Gasoline Production

    Energy Technology Data Exchange (ETDEWEB)

    Hadder, G.R.

    1998-11-24

    The Oak Ridge National Laboratory (OWL) Refinery Yield Model (RYM) has been used to estimate the demand for ethanol in U.S. gasoline production in year 2010. Study cases examine ethanol demand with variations in world oil price, cost of competing oxygenate, ethanol value, and gasoline specifications. For combined-regions outside California summer ethanol demand is dominated by conventional gasoline (CG) because the premised share of reformulated gasoline (RFG) production is relatively low and because CG offers greater flexibility for blending high vapor pressure components like ethanol. Vapor pressure advantages disappear for winter CG, but total ethanol used in winter RFG remains low because of the low RFG production share. In California, relatively less ethanol is used in CG because the RFG production share is very high. During the winter in California, there is a significant increase in use of ethanol in RFG, as ethanol displaces lower-vapor-pressure ethers. Estimated U.S. ethanol demand is a function of the refiner value of ethanol. For example, ethanol demand for reference conditions in year 2010 is 2 billion gallons per year (BGY) at a refiner value of $1.00 per gallon (1996 dollars), and 9 BGY at a refiner value of $0.60 per gallon. Ethanol demand could be increased with higher oil prices, or by changes in gasoline specifications for oxygen content, sulfur content, emissions of volatile organic compounds (VOCS), and octane numbers.

  20. Monitoring the oxygenation of the preterm brain : What is there to gain?

    NARCIS (Netherlands)

    Alderliesten, T.

    2016-01-01

    Despite advances in perinatal care, preterm birth is still associated with adverse neurodevelopmental outcome, often caused by cerebral injury. The most common forms of cerebral injury are all associated with disturbances in cerebral oxygen and blood supply. Traditionally, infant wellbeing is evalua

  1. Innovation and Demand

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2007-01-01

    the demand-side of markets in the simplest possible way. This strategy has allowed a gradual increase in the sophistication of supply-side aspects of economic evolution, but the one-sided focus on supply is facing diminishing returns. Therefore, demand-side aspects of economic evolution have in recent years...... received increased attention. The present paper argues that the new emphasis on demand-side factors is quite crucial for a deepened understanding of economic evolution. The major reasons are the following: First, demand represents the core force of selection that gives direction to the evolutionary process....... Second, firms' innovative activities relate, directly or indirectly, to the structure of expected and actual demand. Third, the demand side represents the most obvious way of turning to the much-needed analysis of macro-evolutionary change of the economic system....

  2. Cerebral microangiopathies; Zerebrale Mikroangiopathien

    Energy Technology Data Exchange (ETDEWEB)

    Linn, Jennifer [Klinikum der Universitaet Muenchen (Germany). Abt. fuer Neuroradiologie

    2011-03-15

    Cerebral microangiopathies are a very heterogenous group of diseases characterized by pathological changes of the small cerebral vessels. They account for 20 - 30 % of all ischemic strokes. Degenerative microangiopathy and sporadic cerebral amyloid angiography represent the typical acquired cerebral microangiopathies, which are found in over 90 % of cases. Besides, a wide variety of rare, hereditary microangiopathy exists, as e.g. CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), Fabrys disease and MELAS syndrome (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes). (orig.)

  3. Assessment of the hand in cerebral palsy

    Directory of Open Access Journals (Sweden)

    Praveen Bhardwaj

    2011-01-01

    Full Text Available Cerebral palsy is the musculoskeletal manifestation of a nonprogressive central nervous system lesion that usually occurs due to a perinatal insult to the brain. Though the cerebral insult is static the musculoskeletal pathology is progressive. Some patients with cerebral palsy whose hands are affected can be made better by surgery. The surgical procedures as such are not very technically demanding but the assessment, decision-making, and selecting the procedures for the given patient make this field challenging. When done well, the results are rewarding not only in terms of improvement in hand function but also in appearance and personal hygiene, which leads to better self-image and permits better acceptance in the society. This article focuses on the clinical examination, patient selection, and decision-making while managing these patients.

  4. Clinical review : use of venous oxygen saturations as a goal - a yet unfinished puzzle

    NARCIS (Netherlands)

    van Beest, Paul; Wietasch, Gotz; Scheeren, Thomas; Spronk, Peter; Kuiper, Michael

    2011-01-01

    Shock is defined as global tissue hypoxia secondary to an imbalance between systemic oxygen delivery and oxygen demand. Venous oxygen saturations represent this relationship between oxygen delivery and oxygen demand and can therefore be used as an additional parameter to detect an impaired

  5. PERFECT DEMAND ILLUSION

    Directory of Open Access Journals (Sweden)

    Alexander Yu. Sulimov

    2015-01-01

    Full Text Available The article is devoted to technique «Perfect demand illusion», which allows to strengthen the competitive advantageof retailers. Also in the paper spells out the golden rules of visual merchandising.The definition of the method «Demand illusion», formulated the conditions of its functioning, and is determined by the mainhypothesis of the existence of this method.Furthermore, given the definition of the «Perfect demand illusion», and describes its additional conditions. Also spells out the advantages of the «Perfect demandillusion», before the «Demand illusion».

  6. Divers of Passenger Demand

    OpenAIRE

    Wittmer, Andreas

    2011-01-01

    -Overview drivers of passenger demand -Driver 1: Economic growth in developing countries -Driver 2: International business travel in developed countries -Driver 3: International leisure travel in developed countries

  7. Optical measures of changes in cerebral vascular tone during voluntary breath holding and a Sternberg memory task.

    Science.gov (United States)

    Tan, Chin Hong; Low, Kathy A; Schneider-Garces, Nils; Zimmerman, Benjamin; Fletcher, Mark A; Maclin, Edward L; Chiarelli, Antonio M; Gratton, Gabriele; Fabiani, Monica

    2016-07-01

    The human cerebral vasculature responds to changes in blood pressure and demands for oxygenation via cerebral autoregulation. Changes in cerebrovascular tone (vasoconstriction and vasodilation) also mediate the changes in blood flow measured by the BOLD fMRI signal. This cerebrovascular reactivity is known to vary with age. In two experiments, we demonstrate that cerebral pulse parameters measured using optical imaging can quantify changes in cerebral vascular tone, both globally and locally. In experiment 1, 51 older adults (age range=55-87) performed a voluntary breath-holding task while cerebral pulse amplitude measures were taken. We found significant pulse amplitude variations across breath-holding periods, indicating vasodilation during, and vasoconstriction after breath holding. The breath-holding index (BHI), a measure of cerebrovascular reactivity (CVR) was derived and found to correlate with age. BHI was also correlated with performance in the Modified Mini-Mental Status Examination, even after controlling for age and education. In experiment 2, the same participants performed a Sternberg task, and changes in regional pulse amplitude between high (set-size 6) and low (set-size 2) task loads were compared. Only task-related areas in the fronto-parietal network (FPN) showed significant reduction in pulse amplitude, indicating vasodilation. Non-task-related areas such as the somatosensory and auditory cortices did not show such reductions. Taken together, these experiments suggest that optical pulse parameters can index changes in brain vascular tone both globally and locally, using both physiological and cognitive load manipulations. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Paramedic Physical Demands Analysis

    Science.gov (United States)

    2014-07-01

    medical bags, cardiac monitor, stretcher, stair chair, etc.) were not standardized across services. As a result the total amount of equipment weight ...report describes the pushing/pulling, walking, and stair climbing demands as observed during the observation periods. Walking demands varied between the...standard deviation about the mean. .................................................................. 25 Figure 7 - The maximum weight (heaviest patient

  9. Wood supply and demand

    Science.gov (United States)

    Peter J. Ince; David B. McKeever

    2011-01-01

    At times in history, there have been concerns that demand for wood (timber) would be greater than the ability to supply it, but that concern has recently dissipated. The wood supply and demand situation has changed because of market transitions, economic downturns, and continued forest growth. This article provides a concise overview of this change as it relates to the...

  10. Causality in demand

    DEFF Research Database (Denmark)

    Nielsen, Max; Jensen, Frank; Setälä, Jari;

    2011-01-01

    This article focuses on causality in demand. A methodology where causality is imposed and tested within an empirical co-integrated demand model, not prespecified, is suggested. The methodology allows different causality of different products within the same demand system. The methodology is applied...... to fish demand. On the German market for farmed trout and substitutes, it is found that supply sources, i.e. aquaculture and fishery, are not the only determinant of causality. Storing, tightness of management and aggregation level of integrated markets might also be important. The methodological...... implication is that more explicit focus on causality in demand analyses provides improved information. The results suggest that frozen trout forms part of a large European whitefish market, where prices of fresh trout are formed on a relatively separate market. Redfish is a substitute on both markets...

  11. Advances in the Management of Cerebral Vascular Disease

    Directory of Open Access Journals (Sweden)

    Muhammad Imran Qadir

    2015-06-01

    Full Text Available A cerebral vascular disease occurred with the arteries of brain due to the less supply of blood.  Stroke is mostly caused by cerebral vascular disease and it is also a common cause of vascular dementia due to reduced oxygen supply and blood flow to the brain. In industrialized countries, neurologic disability is most frequently caused by cerebeovascular disease. Individuals with cardiovascular disease, diabetes and high blood pressure etc are at higher possibility for cerebral vascular disease. After malignancy and heart disease, cerebral vascular disease is the third leading of death and estimated that an average 500,000 new stroke occurred in each year. Advance techniques such as Carotid Endarterectomy, Magnetic resonance imaging, Angiography and Single photon emission computed tomography etc are used for management of cerebral vascular disease.

  12. Frontal lobe oxygenation is maintained during hypotension following propofol-fentanyl anesthesia

    NARCIS (Netherlands)

    P. Nissen; J.J. van Lieshout; H.B. Nielsen; N.H. Secher

    2009-01-01

    Near-infrared spectroscopy (NIRS) assesses cerebral oxygen saturation (Sco2) as a balance between cerebral oxygen delivery and consumption. In 71 patients, we evaluated whether marked reduction in mean arterial pressure (MAP) during propofol-fentanyl anesthesia induction affects frontal lobe Sco2. T

  13. Using oxygen at home

    Science.gov (United States)

    Oxygen - home use; COPD - home oxygen; Chronic obstructive airways disease - home oxygen; Chronic obstructive lung disease - home oxygen; Chronic bronchitis - home oxygen; Emphysema - home oxygen; Chronic respiratory ...

  14. Cerebral oximetry and cerebral blood flow monitoring in 2 pediatric survivors with out-of-hospital cardiac arrest.

    Science.gov (United States)

    Abramo, Thomas; Aggarwal, Nitin; Kane, Ian; Crossman, Kristen; Meredith, Mark

    2014-04-01

    In pediatric out-of-hospital cardiac arrest (POHCA), cardiovascular monitoring tools have improved resuscitative endeavors and cardiovascular outcomes but with still poor neurologic outcomes. Regarding cardiac arrest in patients with congenital heart disease during surgery, the application of cerebral oximetry with blood volume index (BVI) during the resuscitation has shown significant results and prognostic significance. We present 2 POHCA patients who had cerebral oximetry with BVI monitoring during their arrest and postarrest phase in the emergency department and its potential prognostic aspect.Basic procedures include left and right cerebral oximetry with BVI monitoring at every 5-second interval during cardiac arrest, resuscitation, and postarrest in 2 POHCA patients in the pediatric emergency department.Regional cerebral tissue oxygen saturation (rSo2) with BVI readings in these 2 POHCA survivors demonstrated interesting cerebral physiology, blood flow, and potential prognostic outcome. In 1 patient, the reference range of cerebral rSo2 with positive blood flow during arrest and postarrest phases consistently occurred. This neurologic monitoring had its significance when the resuscitation effectiveness was used and end-tidal CO2 changes were lost. The other patient's cerebral rSo2 with simultaneous BVI readings and trending showed the effectiveness of the emergency medical services (EMS) resuscitation.Cerebral oximetry with cerebral blood flow index monitoring in these POHCA survivors demonstrates compelling periarrest and postarrest cerebral physiology information and prognostication. Cerebral oximetry with cerebral BVI monitoring during these arrest phases has potential as a neurologic monitor for the resuscitative intervention's effectiveness and its possible neurologic prognostic application in the pediatric OCHA patients.

  15. 非心脏大手术老年患者术后认知功能障碍与术中脑氧代谢的关系%Relationship between postoperative cognitive dysfunction after major non-cardiac surgery and intraoperative cerebral oxygen metabolism in elder patients

    Institute of Scientific and Technical Information of China (English)

    蔡一榕; 薛张纲; 朱彪

    2008-01-01

    Objective To investigate the changes of cognitive function after major non-cardiac surgery and the relationship between the postoperative cognitive dysfunction(POCD)and the intraoperative cerebral oxygen metabolism in the elderly.Methods Sixty-four patients(49 male,12 female)aged 65-85 yr undergoing elective major non-cardiac surgery were enrolled in this study.A battery of four neuropsycbological tests was administered 2-3 days before and 7 days after surgery by an experienced psychometrician.A postoperative deficit in any test was defined as a cognitive decline by more than or equal to the preoperative standard deviation of that test in all patients.As long aft any patient showed cognitive decline in two or more tests.this situation was defined as POCD.Blood samples were taken from radial artery and internal jugIIlar vein simultaneously for blood gas analysis immediately (T1) and 2 h (T2) after induction of anesthesia,and just before leaving postanesthesia care unit (T3).The ratio of cerebral blood flow to cerebral oxygen metabolic rate(CBF.CMR02)was calculated.Results Sixty-one patients completed postoperative neuropsychological tests and 10 cases(16.4%)had POCD.Logistic regression analysis showed that the abnormality of CBF/CMR02 during operation was associated with the occurrence of POCD.Conclusion The occurrence of POCD after major non-cardiac surgery is related to the abnormality of cerebral oxygen metabolism during operation.%目的 探讨非心脏大手术老年患者术后认知功能的改变及与术中脑氧代谢的关系.方法 择期非心脏大手术老年患者64例,年龄65~85岁,于术前2~3 d和术后第7天时,分别由心理医师进行一次神经心理测验.在单项测验中术前与术后分值之差≥1个术前分值标准差定为认知功能受损,一个患者在2项或2项以上测验中出现认知功能受损则定为认知功能障碍.于麻醉诱导后即刻、2 h、离开麻醉恢复室时分别同步采集桡动脉和颈

  16. Smerter hos børn og unge med cerebral parese

    DEFF Research Database (Denmark)

    Rastoder, Ema; Brown, Annemette; Reinhardt Pedersen, Charlotte

    2016-01-01

    Although children diagnosed with cerebral palsy have a number of pain triggers (directly from the cerebral palsy, from sequelae and iatrogenic), pain is underdiagnosed. The gap between research and clinical practice is well-known as this group of patients demand special knowledge regarding monito...... monitoring of pain. This article presents various pain-monitoring methods. Combining different methods may improve pain assessment and thereby improve quality of life for children with cerebral palsy....

  17. Cerebral Air Embolism from Angioinvasive Cavitary Aspergillosis

    Directory of Open Access Journals (Sweden)

    Chen Lin

    2014-01-01

    Full Text Available Background. Nontraumatic cerebral air embolism cases are rare. We report a case of an air embolism resulting in cerebral infarction related to angioinvasive cavitary aspergillosis. To our knowledge, there have been no previous reports associating these two conditions together. Case Presentation. A 32-year-old female was admitted for treatment of acute lymphoblastic leukemia (ALL. Her hospital course was complicated by pulmonary aspergillosis. On hospital day 55, she acutely developed severe global aphasia with right hemiplegia. A CT and CT-angiogram of her head and neck were obtained demonstrating intravascular air emboli within the left middle cerebral artery (MCA branches. She was emergently taken for hyperbaric oxygen therapy (HBOT. Evaluation for origin of the air embolus revealed an air focus along the left lower pulmonary vein. Over the course of 48 hours, her symptoms significantly improved. Conclusion. This unique case details an immunocompromised patient with pulmonary aspergillosis cavitary lesions that invaded into a pulmonary vein and caused a cerebral air embolism. With cerebral air embolisms, the acute treatment option differs from the typical ischemic stroke pathway and the provider should consider emergent HBOT. This case highlights the importance of considering atypical causes of acute ischemic stroke.

  18. Impact of Intraoperative Events on Cerebral Tissue Oximetry in Patients Undergoing Cardiopulmonary Bypass.

    Science.gov (United States)

    Ševerdija, Ervin E; Vranken, Nousjka P A; Teerenstra, Steven; Ganushchak, Yuri M; Weerwind, Patrick W

    2015-03-01

    Previous studies showed that decreased cerebral saturation during cardiac surgery is related to adverse postoperative outcome. Therefore, we investigated the influence of intraoperative events on cerebral tissue saturation in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). A total of 52 adult patients who underwent cardiac surgery using pulsatile CPB were included in this prospective explorative study. Cerebral tissue oxygen saturation (SctO2) was measured in both the left and right cerebral hemisphere. Intraoperative events, involving interventions performed by anesthesiologist, surgeon, and clinical perfusionist, were documented. Simultaneously, in-line hemodynamic parameters (partial oxygen pressure, partial carbon dioxide pressure, hematocrit, arterial blood pressure, and CPB flow rates) were recorded. Cerebral tissue saturation was affected by anesthetic induction (p retractor (p cardiac surgery. Future studies are needed to identify methods of mitigating periods of reduced cerebral saturation.

  19. Domestic Demand Will Work

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China can invigorate its economy by expanding domestic demand and boosting consumption chinese bankers are preparing to set up finance companies that provide consumer loans in major cities like Beijing and Shanghai.

  20. Intelligent energy demand forecasting

    CERN Document Server

    Hong, Wei-Chiang

    2013-01-01

    This book offers approaches and methods to calculate optimal electric energy allocation, using evolutionary algorithms and intelligent analytical tools to improve the accuracy of demand forecasting. Focuses on improving the drawbacks of existing algorithms.

  1. Household fuel demand analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cohn, S.; Hirst, E.; Jackson, J.

    1976-01-01

    This study develops econometric models of residential demands for electricity, natural gas, and petroleum products. Fuel demands per household are estimated as functions of fuel prices, per capita income, heating degree days, and mean July temperature. Cross-sectional models are developed using a large data base containing observations for each state and year from 1951 through 1974. Long-run own-price elasticities for all three fuels are greater than unity with natural gas showing the greatest sensitivity to own-price changes. Cross-price elasticities are all less than unity except for the elasticity of demand for oil with respect to the price of gas (which is even larger than the own-price elasticity of demand for oil). The models show considerable stabiity with respect to own-price elasticities but much instability with respect to the cross-price and income elasticities.

  2. Impact of Energy Demands

    Science.gov (United States)

    Cambel, Ali B.

    1970-01-01

    The types of pollutants associated with the process of power production are identified. A nine-point proposal is presented on the ways the increase in power demands might be achieved with the minimum threat to the environment. (PR)

  3. Neuroprotection via matrix-trophic coupling between cerebral endothelial cells and neurons

    OpenAIRE

    Guo, Shuzhen; Kim, Woo Jean; Lok, Josephine; Lee, Sun-Ryung; Besancon, Elaine; Luo, Bing-Hao; Stins, Monique F.; Wang, Xiaoying; Dedhar, Shoukat; Lo, Eng H.

    2008-01-01

    The neurovascular unit is an emerging concept that emphasizes homeostatic interactions between endothelium and cerebral parenchyma. Here, we show that cerebral endothelium are not just inert tubes for delivering blood, but they also secrete trophic factors that can be directly neuroprotective. Conditioned media from cerebral endothelial cells broadly protects neurons against oxygen-glucose deprivation, oxidative damage, endoplasmic reticulum stress, hypoxia, and amyloid neurotoxicity. This ph...

  4. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic

    OpenAIRE

    Powers, William. J.; Videen, Tom O.; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S.

    2011-01-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO2) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO2, CMRglc, and other covariates as predictors of resting ...