Magnesium(Mg)alloys are popular biodegradable metals studied for orthopedic and cardiovascular applications,mainly because Mg ions are essential trace elements known to promote angiogenesis and osteogenesis.However,Mg...Magnesium(Mg)alloys are popular biodegradable metals studied for orthopedic and cardiovascular applications,mainly because Mg ions are essential trace elements known to promote angiogenesis and osteogenesis.However,Mg corrosion consists of oxidation and reduction reactions that produce by-products,such as hydrogen gas,reactive oxygen species,and hydroxides.It is still unclear how all these by-products and Mg ions concomitantly alter the microenvironment and cell behaviors spatially and temporally.This study shows that Mg corrosion can enhance cell proliferation by reducing intracellular ROS.However,Mg cannot decrease ROS and promote cell proliferation in simulated inflammatory conditions,meaning the microenvironment is critical.Furthermore,cells may respond to Mg ions differently in chronic or acute alkaline pH or oxidative stress.Depending on the corrosion rate,Mg modulates HIF1αand many signaling pathways like PI3K/AKT/mTOR,mitophagy,cell cycle,and oxidative phosphorylation.Therefore,this study provides a fundamental insight into the importance of reduction reactions in Mg alloys.展开更多
Air-side economizers are increasingly used to take advantage of“free-cooling”in data centers with the intent of reducing the carbon footprint of buildings.However,they can introduce outdoor pollutants to indoor envi...Air-side economizers are increasingly used to take advantage of“free-cooling”in data centers with the intent of reducing the carbon footprint of buildings.However,they can introduce outdoor pollutants to indoor environment of data centers and cause corrosion damage to the information technology equipment.To evaluate the reliability of information technology equipment under various thermal and air-pollution conditions,a mechanistic model based on multi-ion transport and chemical reactions was developed.The model was used to predict Cu corrosion caused by Cl_(2)-containing pollutant mixtures.It also accounted for the effects of temperature(25℃and 28℃),relative humidity(50%,75%,and 95%),and synergism.It also identified higher air temperature as a corrosion barrier and higher relative humidity as a corrosion accelerator,which agreed well with the experimental results.The average root mean square error of the prediction was 13.7Å.The model can be used to evaluate the thermal guideline for data centers design and operation when Cl_(2)is present based on pre-established acceptable risk of corrosion in data centers’environment.展开更多
基金supported by the National Key R&D Program of China(2021YFC2400500)Guangdong Marine Economic Development Pro-gram(GDNRC[2023]35)+3 种基金National Natural Science Foundation of China(U2001221,32161160327,and 52250410340)NSFC-RGC Joint Research Scheme(N_HKU753121)the Shenzhen Science and Technology Program(JSGGKQTD20210831174330015,JCYJ20220531095811027)Shenzhen Medical Research Fund(B2302031).
文摘Magnesium(Mg)alloys are popular biodegradable metals studied for orthopedic and cardiovascular applications,mainly because Mg ions are essential trace elements known to promote angiogenesis and osteogenesis.However,Mg corrosion consists of oxidation and reduction reactions that produce by-products,such as hydrogen gas,reactive oxygen species,and hydroxides.It is still unclear how all these by-products and Mg ions concomitantly alter the microenvironment and cell behaviors spatially and temporally.This study shows that Mg corrosion can enhance cell proliferation by reducing intracellular ROS.However,Mg cannot decrease ROS and promote cell proliferation in simulated inflammatory conditions,meaning the microenvironment is critical.Furthermore,cells may respond to Mg ions differently in chronic or acute alkaline pH or oxidative stress.Depending on the corrosion rate,Mg modulates HIF1αand many signaling pathways like PI3K/AKT/mTOR,mitophagy,cell cycle,and oxidative phosphorylation.Therefore,this study provides a fundamental insight into the importance of reduction reactions in Mg alloys.
基金This work was supported by American Society of Heating,Refrigerating and Air-conditioning Engineers and Syracuse University.The authors appreciate the writing support from the US Department of Energy’s Oak Ridge National Laboratory.
文摘Air-side economizers are increasingly used to take advantage of“free-cooling”in data centers with the intent of reducing the carbon footprint of buildings.However,they can introduce outdoor pollutants to indoor environment of data centers and cause corrosion damage to the information technology equipment.To evaluate the reliability of information technology equipment under various thermal and air-pollution conditions,a mechanistic model based on multi-ion transport and chemical reactions was developed.The model was used to predict Cu corrosion caused by Cl_(2)-containing pollutant mixtures.It also accounted for the effects of temperature(25℃and 28℃),relative humidity(50%,75%,and 95%),and synergism.It also identified higher air temperature as a corrosion barrier and higher relative humidity as a corrosion accelerator,which agreed well with the experimental results.The average root mean square error of the prediction was 13.7Å.The model can be used to evaluate the thermal guideline for data centers design and operation when Cl_(2)is present based on pre-established acceptable risk of corrosion in data centers’environment.
