Sepsis represents a deranged and exaggerated systemic inflammatory response to infection and is associated with vascular and metabolic abnormalities that trigger systemic organic dysfunction.Mitochondrial function has...Sepsis represents a deranged and exaggerated systemic inflammatory response to infection and is associated with vascular and metabolic abnormalities that trigger systemic organic dysfunction.Mitochondrial function has been shown to be severely impaired during the early phase of critical illness,with a reduction in biogenesis,increased generation of reactive oxygen species and a decrease in adenosine triphosphate synthesis of up to 50%.Mitochondrial dysfunction can be assessed using mitochondrial DNA concentration and respirometry assays,particularly in peripheral mononuclear cells.Isolation of monocytes and lymphocytes seems to be the most promising strategy for measuring mitochondrial activity in clinical settings because of the ease of collection,sample processing,and clinical relevance of the association between metabolic alterations and deficient immune responses in mononuclear cells.Studies have reported alterations in these variables in patients with sepsis compared with healthy controls and non-septic patients.However,few studies have explored the association between mitochondrial dysfunction in immune mononuclear cells and unfavorable clinical outcomes.An improvement in mitochondrial parameters in sepsis could theoretically serve as a biomarker of clinical recovery and response to oxygen and vasopressor therapies as well as reveal unexplored pathophysiological mechanistic targets.These features highlight the need for further studies on mitochondrial metabolism in immune cells as a feasible tool to evaluate patients in intensive care settings.The evaluation of mitochondrial metabolism is a promising tool for the evaluation and management of critically ill patients,especially those with sepsis.In this article,we explore the pathophysiological aspects,main methods of measurement,and the main studies in this field.展开更多
Oxygen uptake under starvation and short periods of sudden temperature change was measured forlarval herring （Clupea harengus L.） reared at average temperature of 7.3, 11 and 12.9℃. Larval stagesbetween first feedi...Oxygen uptake under starvation and short periods of sudden temperature change was measured forlarval herring （Clupea harengus L.） reared at average temperature of 7.3, 11 and 12.9℃. Larval stagesbetween first feeding and premetamorphosis were used. For comparison, the routine oxygen uptake（ROU） was also investigated and followed the relationship Q=0.974+0. 174 tW<sup>0.210</sup>, where Q is in μg/（mg·h）, W is dry body weight in mg and t is temperature in ℃. The oxygen uptake under starvation（SOU, deprived of food for 24 h） was different from the routine when the larval dry weightwas less than 0.6-0.8 mg, it increased with temperature and body weight giving the reationship Q=1.568+0.110 tW<sup>0.380</sup>, if the larval dry weight mp more than 0.6-0.8 mg, it reverted to the norm(Q=1.704+0.078 tW<sup>-0.349</sup>). The oxygen uptake was tested in short periods （3 h） of sudden temperaturechanges in six groups: 7.3 to 11, 7.3 to 12.9, 11 to 7.3. 11 to 12.9, 12.9 to 7.3 and 1.29 to11℃. The oxygen uptake in the 7.3 to 12.9 and展开更多
Oxygen consumption is a fundamental component of metabolic networks, mitochondrial function, and global carbon cycling. To date there is no method available that allows for replicate measurements on attached and unatt...Oxygen consumption is a fundamental component of metabolic networks, mitochondrial function, and global carbon cycling. To date there is no method available that allows for replicate measurements on attached and unattached biological samples without compensation for extraneous oxygen leaking into the system. Here we present the Respiratory Detection System, which is compatible with virtually any biological sample. The RDS can be used to measure oxygen uptake in microliter-scale volumes with a reversibly sealed sample chamber, which contains a porphyrin-based oxygen sensor. With the RDS, one can maintain a diffusional seal for up to three hours, allowing for the direct measurement of respiratory function of samples with fast or slow metabolic rates. The ability to easily measure oxygen uptake in small volumes with small populations or dilute samples has implications in cell biology, environmental biology, and clinical diagnostics.展开更多
Present drilling fluids for deep water wells have severe degenerative effect on the environment with high operational and disposal costs.Thus,making them less desirable in recent times.Ester synthetic drilling fluid p...Present drilling fluids for deep water wells have severe degenerative effect on the environment with high operational and disposal costs.Thus,making them less desirable in recent times.Ester synthetic drilling fluid provides a novel environmentally friendly alternative but conventional ester-based drilling fluids exhibit high viscosities in deep-water wells causing excessive equivalent circulating density(ECD)and increased risk of lost circulation owing to narrow mud density window.This study experimentally investigates the critical fluid properties and aerobic biodegradability potentials of two newly developed deep-water synthetic ester drilling fluids namely:iso-propyl caprylate(COIPE)and iso-propyl linolenate(LOIPE)synthetic fluids and their comparison with synthetic-paraffin(SP-SBF)and isomerized-olefin(IOSBF)synthetic hydrocarbon fluids.The esters of iso-propyl caprylate and iso-propyl linolenate were produced from the isolation of ester mixtures that were obtained from the homogeneous catalytic transesterification of coconut and linseed plant oil biomass respectively.The COIPE was isolated from the coconut oil iso-propyl ester mixture by low-pressure fractional distillation technique.While fractional distillation and crystallization were used to isolate the LOIPE ester from the linseed oil iso-propyl ester mixture.Meanwhile,the aerobic biodegradation investigation was conducted by a modified oxygen consumption respirometry technique.The GC-MS analysis of the COIPE and LOIPE showed that the former contains essentially of lower saturated carbon compounds(C8).Whereas the latter contains higher molecular weight and unsaturated carbon compounds(C18+).The COIPE and LOIPE kinematic viscosity values are in good agreement with that of the reference synthetic hydrocarbon fluid samples(SP-SBF and IO-SBF).Although,the COIPE synthetic ester has lower viscosity value owing to the presence of shorter chain and saturated carbon atoms(C8 esters).Similarly,the linolenic oil iso-propyl ester has excellent cold flow characteristics for deep-water well drilling owing to lower values of cloud and pour points as a result of higher concentration of poly-unsaturated linolenic esters.The iso-propyl caprylate and the iso-propyl linolenate ester synthetic fluids are readily biodegradable in the sea water inoculum under aerobic condition.However,the iso-propyl caprylate is inherently biodegradable because its degradation level and that of the reference chemical sample were already above 60%during the 10-day window period.The SP-SBF and the IO-SBF synthetic fluids have lower aerobic biodegradation values because they contain little quantity of poly aromatic hydrocarbons as evident in their GC-MS profiles.Finally,esters and unsaturated synthetic-based fluid are more rapidly biodegradable than paraffinic synthetic fluids and the rate of biodegradation of organic compounds decreases as molecular weight increases.展开更多
基金the Fundação de Amparo a Pesquisa do Estado do Rio Grande do Sul,No.1010267.
文摘Sepsis represents a deranged and exaggerated systemic inflammatory response to infection and is associated with vascular and metabolic abnormalities that trigger systemic organic dysfunction.Mitochondrial function has been shown to be severely impaired during the early phase of critical illness,with a reduction in biogenesis,increased generation of reactive oxygen species and a decrease in adenosine triphosphate synthesis of up to 50%.Mitochondrial dysfunction can be assessed using mitochondrial DNA concentration and respirometry assays,particularly in peripheral mononuclear cells.Isolation of monocytes and lymphocytes seems to be the most promising strategy for measuring mitochondrial activity in clinical settings because of the ease of collection,sample processing,and clinical relevance of the association between metabolic alterations and deficient immune responses in mononuclear cells.Studies have reported alterations in these variables in patients with sepsis compared with healthy controls and non-septic patients.However,few studies have explored the association between mitochondrial dysfunction in immune mononuclear cells and unfavorable clinical outcomes.An improvement in mitochondrial parameters in sepsis could theoretically serve as a biomarker of clinical recovery and response to oxygen and vasopressor therapies as well as reveal unexplored pathophysiological mechanistic targets.These features highlight the need for further studies on mitochondrial metabolism in immune cells as a feasible tool to evaluate patients in intensive care settings.The evaluation of mitochondrial metabolism is a promising tool for the evaluation and management of critically ill patients,especially those with sepsis.In this article,we explore the pathophysiological aspects,main methods of measurement,and the main studies in this field.
文摘Oxygen uptake under starvation and short periods of sudden temperature change was measured forlarval herring （Clupea harengus L.） reared at average temperature of 7.3, 11 and 12.9℃. Larval stagesbetween first feeding and premetamorphosis were used. For comparison, the routine oxygen uptake（ROU） was also investigated and followed the relationship Q=0.974+0. 174 tW<sup>0.210</sup>, where Q is in μg/（mg·h）, W is dry body weight in mg and t is temperature in ℃. The oxygen uptake under starvation（SOU, deprived of food for 24 h） was different from the routine when the larval dry weightwas less than 0.6-0.8 mg, it increased with temperature and body weight giving the reationship Q=1.568+0.110 tW<sup>0.380</sup>, if the larval dry weight mp more than 0.6-0.8 mg, it reverted to the norm(Q=1.704+0.078 tW<sup>-0.349</sup>). The oxygen uptake was tested in short periods （3 h） of sudden temperaturechanges in six groups: 7.3 to 11, 7.3 to 12.9, 11 to 7.3. 11 to 12.9, 12.9 to 7.3 and 1.29 to11℃. The oxygen uptake in the 7.3 to 12.9 and
文摘Oxygen consumption is a fundamental component of metabolic networks, mitochondrial function, and global carbon cycling. To date there is no method available that allows for replicate measurements on attached and unattached biological samples without compensation for extraneous oxygen leaking into the system. Here we present the Respiratory Detection System, which is compatible with virtually any biological sample. The RDS can be used to measure oxygen uptake in microliter-scale volumes with a reversibly sealed sample chamber, which contains a porphyrin-based oxygen sensor. With the RDS, one can maintain a diffusional seal for up to three hours, allowing for the direct measurement of respiratory function of samples with fast or slow metabolic rates. The ability to easily measure oxygen uptake in small volumes with small populations or dilute samples has implications in cell biology, environmental biology, and clinical diagnostics.
文摘Present drilling fluids for deep water wells have severe degenerative effect on the environment with high operational and disposal costs.Thus,making them less desirable in recent times.Ester synthetic drilling fluid provides a novel environmentally friendly alternative but conventional ester-based drilling fluids exhibit high viscosities in deep-water wells causing excessive equivalent circulating density(ECD)and increased risk of lost circulation owing to narrow mud density window.This study experimentally investigates the critical fluid properties and aerobic biodegradability potentials of two newly developed deep-water synthetic ester drilling fluids namely:iso-propyl caprylate(COIPE)and iso-propyl linolenate(LOIPE)synthetic fluids and their comparison with synthetic-paraffin(SP-SBF)and isomerized-olefin(IOSBF)synthetic hydrocarbon fluids.The esters of iso-propyl caprylate and iso-propyl linolenate were produced from the isolation of ester mixtures that were obtained from the homogeneous catalytic transesterification of coconut and linseed plant oil biomass respectively.The COIPE was isolated from the coconut oil iso-propyl ester mixture by low-pressure fractional distillation technique.While fractional distillation and crystallization were used to isolate the LOIPE ester from the linseed oil iso-propyl ester mixture.Meanwhile,the aerobic biodegradation investigation was conducted by a modified oxygen consumption respirometry technique.The GC-MS analysis of the COIPE and LOIPE showed that the former contains essentially of lower saturated carbon compounds(C8).Whereas the latter contains higher molecular weight and unsaturated carbon compounds(C18+).The COIPE and LOIPE kinematic viscosity values are in good agreement with that of the reference synthetic hydrocarbon fluid samples(SP-SBF and IO-SBF).Although,the COIPE synthetic ester has lower viscosity value owing to the presence of shorter chain and saturated carbon atoms(C8 esters).Similarly,the linolenic oil iso-propyl ester has excellent cold flow characteristics for deep-water well drilling owing to lower values of cloud and pour points as a result of higher concentration of poly-unsaturated linolenic esters.The iso-propyl caprylate and the iso-propyl linolenate ester synthetic fluids are readily biodegradable in the sea water inoculum under aerobic condition.However,the iso-propyl caprylate is inherently biodegradable because its degradation level and that of the reference chemical sample were already above 60%during the 10-day window period.The SP-SBF and the IO-SBF synthetic fluids have lower aerobic biodegradation values because they contain little quantity of poly aromatic hydrocarbons as evident in their GC-MS profiles.Finally,esters and unsaturated synthetic-based fluid are more rapidly biodegradable than paraffinic synthetic fluids and the rate of biodegradation of organic compounds decreases as molecular weight increases.
