The Experts below are selected from a list of 11673 Experts worldwide ranked by ideXlab platform

Frank A Dinenno - One of the best experts on this subject based on the ideXlab platform.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk of ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining the skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk for ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential. # Novelty and Significance {#article-title-41}

Brett S Kirby - One of the best experts on this subject based on the ideXlab platform.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk of ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining the skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk for ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential. # Novelty and Significance {#article-title-41}

Seok Won Hong - One of the best experts on this subject based on the ideXlab platform.

  • water Deoxygenation using a hollow fiber membrane contactor to prevent pipe corrosion for sustainable management of district heating systems a pilot scale study
    Journal of Cleaner Production, 2020
    Co-Authors: Jiho Lee, Soomin Baek, Chanhee Boo, Aseom Son, Hoseok Jung, Sung Soo Park, Seok Won Hong
    Abstract:

    Abstract Dissolved oxygen (DO) is a key factor affecting pipe corrosion in district heating systems (DHS). This study demonstrated effective Deoxygenation of water in a DHS using a hollow fiber membrane contactor (HFMC) via systematic investigation from lab-to pilot-scale. First, Deoxygenation efficiency was evaluated in a lab-scale HFMC with varying operating parameters including an effective membrane area, flow rate and feedwater temperature. Based on the results from the lab-scale investigation, a pilot HFMC system was designed with capacity of 1 m3 per day. To achieve a permeate DO concentration below 10 μg L−1 at feedwater temperatures of 20–60 °C, the vacuum degree needed to be lower than the saturated water vapor pressure of 10–120 Torr. In addition, the primary foulant for membrane fouling was organic matter in the make-up and district heating (DH) return water. A significant change in corrosion response was observed for pipe steel in the DHS after Deoxygenation. Immersion tests for 14 days indicated that weight loss values had greatly reduced by the Deoxygenation process from 39.3 to 1.3 mg cm−2 and from 21.9 to 2.1 mg cm−2 for steel pipe samples immersed in the make-up water and the DH return water of the DHS, respectively. This improved corrosion resistance from Deoxygenation was interpreted by electrochemical analysis. As such, this study offers a pilot-scale demonstration of the feasibility of a hollow fiber membrane-based Deoxygenation process as an effective tool to prevent the corrosion of steel pipes.

Wyatt F Voyles - One of the best experts on this subject based on the ideXlab platform.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk of ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining the skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk for ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential. # Novelty and Significance {#article-title-41}

Anne R Crecelius - One of the best experts on this subject based on the ideXlab platform.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk of ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential.

  • impaired skeletal muscle blood flow control with advancing age in humans attenuated atp release and local vasodilation during erythrocyte Deoxygenation
    Circulation Research, 2012
    Co-Authors: Brett S Kirby, Wyatt F Voyles, Anne R Crecelius, Frank A Dinenno
    Abstract:

    Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during Deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte Deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte Deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, both hypoxia and exercise significantly increased venous [ATP] and ATP effluent (forearm blood flow×[ATP]) draining the skeletal muscle. In contrast, hypoxia and exercise did not increase venous [ATP] in older adults, and both venous [ATP] and ATP effluent were substantially reduced compared with young people despite similar levels of Deoxygenation. Next, we demonstrated that this could not be explained by augmented extracellular ATP hydrolysis in whole blood with age. Finally, we found that Deoxygenation-mediated ATP release from isolated erythrocytes was essentially nonexistent in older adults. Conclusions: Skeletal muscle blood flow during conditions of erythrocyte Deoxygenation was markedly reduced in aging humans, and reductions in plasma ATP and erythrocyte-mediated ATP release may be a novel mechanism underlying impaired vasodilation and oxygen delivery during hypoxemia with advancing age. Because aging is associated with elevated risk for ischemic cardiovascular disease and exercise intolerance, interventions that target erythrocyte-mediated ATP release may offer therapeutic potential. # Novelty and Significance {#article-title-41}