scholarly journals Effects of Flow Rate on Mesenchymal Stem Cell Oxygen Consumption Rates in 3D Bone-Tissue-Engineered Constructs Cultured in Perfusion Bioreactor Systems

Fluids ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 30 ◽  
Author(s):  
Michael L. Felder ◽  
Aaron D. Simmons ◽  
Robert L. Shambaugh ◽  
Vassilios I. Sikavitsas
Keyword(s):  
Stem Cells ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Bone Tissue ◽  
Residence Time ◽  
Flow Rate ◽  
Perfusion Bioreactor ◽  
Flow Rates ◽  
Uptake Rates ◽  
Consumption Rates

Bone grafts represent a multibillion-dollar industry, with over a million grafts occurring each year. Common graft types are associated with issues such as donor site morbidity in autologous grafts and immunological response in allogenic grafts. Bone-tissue-engineered constructs are a logical approach to combat the issues commonly encountered with these bone grafting techniques. When creating bone-tissue-engineered constructs, monitoring systems are required to determine construct characteristics, such as cellularity and cell type. This study aims to expand on the current predictive metrics for these characteristics, specifically analyzing the effects of media flow rate on oxygen uptake rates (OURs) of mesenchymal stem cells seeded on poly(L-lactic acid) (PLLA) scaffolds cultured in a flow perfusion bioreactor. To do this, oxygen consumption rates were measured for cell/scaffold constructs at varying flow rates ranging from 150 to 750 microliters per minute. Residence time analyses were performed for this bioreactor at these flow rates. Average observed oxygen uptake rates of stem cells in perfusion bioreactors were shown to increase with increased oxygen availability at higher flow rates. The residence time analysis helped identify potential pitfalls in current bioreactor designs, such as the presence of channeling. Furthermore, this analysis shows that oxygen uptake rates have a strong linear correlation with residence times of media in the bioreactor setup, where cells were seen to exhibit a maximum oxygen uptake rate of 3 picomoles O2/hr/cell.

Oxygen consumption by eggs of the grubby, Myoxocephalus aenaeus, and the longhorn sculpin, Myoxocephalus octodecemspinosus

1989 ◽  
Vol 67 (7) ◽  
pp. 1613-1619 ◽  
Author(s):  
William A. Walsh ◽  
William A. Lund Jr.
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Temperature Increase ◽  
Abiotic Factors ◽  
Regression Analyses ◽  
Salinity Changes ◽  
Respiration Rates ◽  
Uptake Rates ◽  
Consumption Rates ◽  
Longhorn Sculpin

Oxygen consumption rates of individual eggs of the grubby, Myoxocephalus aenaeus, and the longhorn sculpin, Myoxocephalus octodecemspinosus, were determined by microrespirometry. Eggs of both species were incubated in temperature – salinity combinations (grubby: in 2, 5, 8 °C at 10, 12.5, 15, 20, 25, 30, 35 parts per thousand (ppt); longhorn sculpin: in 2, 5, 8 °C at 15, 17.5, 20, 25, 30, 35 ppt) to determine the effects of these abiotic factors and development on oxygen consumption rates. Respiration rates of eggs of both species were not affected significantly by constant salinities. Multiple regression analyses demonstrated that the natural logarithms of oxygen uptake rates increased linearly with the temperature – age (in hours after fertilization) interaction and parabolically with age in both species. Oxygen consumption rates increased at hatching. Acute salinity changes did not affect embryonic oxygen consumption by either species. An acute temperature increase, however, elicited increased oxygen uptake by longhorn sculpin embryos (Q10 = 2.56).

scholarly journals The SCOC database, a large, open, and global database with sediment community oxygen consumption rates

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Tanja Stratmann ◽  
Karline Soetaert ◽  
Chih-Lin Wei ◽  
Yu-Shih Lin ◽  
Dick van Oevelen
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Selection Procedure ◽  
Ex Situ ◽  
Global Database ◽  
Data Record ◽  
Consumption Rates ◽  
Meta Analyses

Abstract Sediment community oxygen consumption (SCOC) rates provide important information about biogeochemical processes in marine sediments and the activity of benthic microorganisms and fauna. Therefore, several databases of SCOC data have been compiled since the mid-1990s. However, these earlier databases contained much less data records and were not freely available. Additionally, the databases were not transparent in their selection procedure, so that other researchers could not assess the quality of the data. Here, we present the largest, best documented, and freely available database of SCOC data compiled to date. The database is comprised of 3,540 georeferenced SCOC records from 230 studies that were selected following the procedure for systematic reviews and meta-analyses. Each data record states whether the oxygen consumption was measured ex situ or in situ, as total oxygen uptake, diffusive or advective oxygen uptake, and which measurement device was used. The database will be curated and updated annually to secure and maintain an up-to-date global database of SCOC data.

Effect of hemorrhagic hypotension on oxygen consumption of dogs

1964 ◽  
Vol 207 (3) ◽  
pp. 647-649 ◽  
Author(s):  
Elvin E. Smith ◽  
Jack W. Crowell
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Arterial Pressure ◽  
Flow Rate ◽  
Blood Oxygen ◽  
Oxygen Utilization ◽  
Epinephrine Administration ◽  
Utilization Coefficient ◽  
Subsequent Rise

The effects of hematocrit, Dibenzyline, and epinephrine on oxygen consumption were studied in 220 dogs whose arterial pressure was lowered to and maintained at 30 mm Hg. Oxygen consumption was recorded previous to and during the period of hypotension. The average oxygen consumption was 7.20 ml/kg min prior to hemorrhage. Ten minutes after hemorrhage the oxygen consumption was 3.58 ml/kg min (50% of control). After 30 min of hypotension the oxygen consumption was 4.70 ml/kg min (65% of control), and the oxygen consumption increased to 5.33 ml/kg min (74% of control) after 1 hr. Pretreatment with Dibenzyline increased the oxygen consumption during the early stages of hypotension but had little effect in the latter stages. Epinephrine administration decreased the oxygen consumption during the entire hypotensive period. Previous studies have shown that the oxygen utilization coefficient approaches its maximal value during the hypotensive period; therefore, oxygen uptake becomes limited by the blood flow and the changes in oxygen consumption indicate changes in flow rate to active tissue. Simultaneous studies showed that the hematocrit influenced oxygen transport by effects on both the blood oxygen content and the blood flow. The results illustrate that animals with hematocrits of 35–39 are able to transport more oxygen than animals with other hematocrits. Evidence is presented to show that the initial fall and the subsequent rise in oxygen consumption during hypotension may be a local autoregulation of blood flow.

scholarly journals Real-time monitoring of specific oxygen uptake rates of embryonic stem cells in a microfluidic cell culture device

2016 ◽  
Vol 11 (9) ◽  
pp. 1179-1189 ◽  
Author(s):  
Alexandre Super ◽  
Nicolas Jaccard ◽  
Marco Paulo Cardoso Marques ◽  
Rhys Jarred Macown ◽  
Lewis Donald Griffin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Culture ◽  
Embryonic Stem Cells ◽  
Oxygen Uptake ◽  
Real Time ◽  
Embryonic Stem ◽  
Real Time Monitoring ◽  
Uptake Rates ◽  
Microfluidic Cell Culture

Perfusion-independent oxygen extraction in myoglobin-rich hearts

1988 ◽  
Vol 135 (1) ◽  
pp. 301-315
Author(s):  
J. R. Bailey ◽  
W. R. Driedzic
Keyword(s):  
Oxygen Consumption ◽  
Flow Rate ◽  
Oxygen Demand ◽  
High Oxygen ◽  
Oxygen Extraction ◽  
Oxidizing Agent ◽  
Flow Rates ◽  
Sea Raven ◽  
High Oxygen Demand

Cardiac myoglobin plays a role in oxygen consumption and has a protective effect during periods of hypoxia, but little is known about the role of myoglobin during periods of ischaemia. Myoglobin-rich sea raven hearts and myoglobin-poor ocean pout hearts were isolated and perfused at varying flow rates and under conditions of low and high oxygen demand to assess the role of myoglobin in oxygen extraction. In the myoglobin-rich hearts, oxygen extraction remained constant over the flow range. In the myoglobin-poor hearts, oxygen extraction was significantly elevated, relative to controls, at the lower flow rates but decreased as the flow rate increased. In hearts where myoglobin was inactivated by an oxidizing agent, oxygen extraction was similar to that observed in myoglobin-poor hearts. Under conditions of high oxygen demand, myoglobin-rich hearts again showed a constant oxygen extraction over the flow range. Myoglobin-inactivated hearts had a significantly elevated oxygen extraction at low flows, and this decreased as flow rate increased. These data suggest that myoglobin renders oxygen extraction by fish hearts independent of the rate of perfusion.

scholarly journals The effect of reduction of perfusion rate on lactate and oxygen uptake, glucose output and energy supply in the isolated perfused liver of starved rats

1979 ◽  
Vol 184 (3) ◽  
pp. 635-642 ◽  
Author(s):  
R A Iles ◽  
P G Baron ◽  
R D Cohen
Keyword(s):  
Oxygen Uptake ◽  
Flow Rate ◽  
Mean Value ◽  
Normal Flow ◽  
Perfusion Rate ◽  
Flow Rates ◽  
Perfusate Flow ◽  
Intrinsic Capacity ◽  
Lactate Uptake ◽  
Glucose Output

1. Lactate and O2 uptake and glucose output were studied in isolated livers from starved rats at perfusate flow rates varying from 100 to 7% of “normal” (11.25-0.75 ml/min per 100 g body wt.). 2. With moderate diminution of flow rate, lactate and oxygen uptake fell more slowly than would be expected if uptake purely depended on substrate supply. 3. Use of a mathematical model suggests that the intrinsic capacity of the liver for lactate uptake is unaffected until the flow rate falls below 25% of “normal”. 4. Some lactate uptake was always observed even at 7% of the “normal” flow rate. 5. At flow rates below 33% of the “normal”, lactate was increasingly metabolized by pathways other than gluconeogenesis, which became a progressively less important consumer of available O2. 6. ATP content decreased with diminution of flow rate, but substantially less markedly than did lactate uptake and glucose output. 7. Intracellular pH fell from a mean value of 7.25 at “normal” flow rate to 7.03 at 7% of the “normal” flow rate.

Respiration of Artemia franciscana cultured under different salinities

2011 ◽  
Vol 61 (4) ◽  
pp. 413-425 ◽  
Author(s):  
Mona M. El-Gamal
Keyword(s):  
Oxygen Consumption ◽  
Brine Shrimp ◽  
Developmental Stages ◽  
External Medium ◽  
Artemia Franciscana ◽  
Uptake Rates ◽  
Wide Range ◽  
Brine Shrimps ◽  
Consumption Rates ◽  
Oxygen Tensions

AbstractThe available studies on oxygen consumption by Artemia related to different salinities reported contradictory results. However, most of these studies have been obtained only for newly hatched nauplii or adults, and have neglected the gradual accommodation that gives a picture about what really happens in nature. In order to face the problems noted above individuals of Artemia franciscana were acclimated to four different salinities (25 g/L, 35 g/L, 70 g/L and 120 g/L) under laboratory conditions. The oxygen consumption under declining oxygen tensions (Po 2) for each of the 19 stages in Artemia life metamorphic developments was examined. The brine shrimp under different salinities is a respiratory regulator over a wide range of Po 2's. Oxygen consumption rates varied across the salinities with a general inverse relationship in uptake rates versus salinity. The brine shrimps' individual weight significantly decreased with increasing salt concentration of the external medium. Generally, regulation of oxygen consumption improved with development. Specimens cultured under high salinities (70 g/L and 120 g/L) started the regulation earlier than low salinities, even before heart and gill formation (in stage 2) and high salinities also accelerated the development of the heart and the gut earlier than those cultured under lower salinities (stage 3 instead of 6). Later developmental stages did not perform osmotical work in the same manner as nauplii did (0-6) and oxygen consumption did not drive the ionic regulation of Artemia franciscana specimens cultured under different salinities.

scholarly journals EFFECT OF NAOH CONCENTRATION AND RESIDENCE TIME ON THE CONVERSION OF REMOVAL OF Ca2+ AND Mg2+ IN SEAWATER CONTINUOUSLY USING AN BAFFLED REACTOR

Konversi ◽  
2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Dita Nurmala Tristanti ◽  
Harishul Ulum ◽  
Soemargono Soemargono ◽  
Nove Kartika Erliyanti
Keyword(s):  
Residence Time ◽  
Flow Rate ◽  
Gas Flow ◽  
Air Flow ◽  
Gas Flow Rate ◽  
Flow Rates ◽  
Naoh Solution

The aims of this study were to determine the effect NaOH concentration and residence time on the conversion of calcium (Ca2+) and magnesium (Mg2+) removal as impurities. The concentration of NaOH used in this study were 0.05N, 0,1N, 0.15N, and 0,2N. The reactor used in this study is an baffled reactor equipped with air as a stirrer with air flow rates of 10000, 15000, 20000, 25000, and 30000 ml/minute. The ratio between the flow rate of seawater toward the flow rate of NaOH solution in this study was 85ml/minute : 25ml/minute.The results showed that the NaOH concentration and residence time had a significant effect on the conversion of removal of (Ca2+) and magnesium (Mg2+) impurities. The best results were obtained at 0.25N NaOH concentration, residence time of 13,08 minute, and gas flow rate of 30000ml/minute with removal conversion of calcium (Ca2+) of 73.083% and magnesium (Mg2+) of 89.621%.

Quantifying Compound Aging Resistance at Service (Ambient) Temperatures

2009 ◽  
Vol 82 (1) ◽  
pp. 121-130
Author(s):  
Edward R. Terrill ◽  
James T. Lewis
Keyword(s):  
Oxygen Consumption ◽  
Service Life ◽  
Oxygen Uptake ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Tensile Elongation ◽  
Ambient Temperatures ◽  
Rubber Compounds ◽  
Consumption Rates ◽  
The Stability

Abstract Oxygen consumption rates were measured on natural rubber compounds with varying levels of a standard antioxidant package. The oxygen consumption rate measurements were performed at temperatures between 20 °C and 80 °C. The results elucidated the mechanism of antioxidants, including their pro-oxidant effects. The pro-oxidant effect dwindled with time. Integrated oxygen uptake results were calculated from repetitive oxygen consumption rate measurements. Integrated oxygen uptake time temperature master curves with empirical shift factors were combined with elongation-tobreak data to monitor the extent of aging. The stability of the compounds at service life temperatures could be quantified by combining the integrated oxygen uptake shift factors with the tensile elongation-to-break data; thereby to produce an elongation-to-break master curve at service life temperatures.

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