Harvesting energy from environmental sources such as solar and wind can mitigate or solve the limited-energy problem in wireless sensor networks. In this paper, we propose an energy-harvest-aware route-selection metho...Harvesting energy from environmental sources such as solar and wind can mitigate or solve the limited-energy problem in wireless sensor networks. In this paper, we propose an energy-harvest-aware route-selection method that incorporates harvest availability properties and energy storage capacity limits into the routing decisions. The harvest-aware routing problem is formulated as a lin- ear program with a utility-based objective function that balances the two conflicting routing objectives of maximum total and maxi- mum minimum residual network energy. The simulation results show that doing so achieves a longer network lifetime, defined as the time-to-first-node-death in the network. Additionally, most existing energy-harvesting routing algorithms route each traffic flow independently from each other. The LP formulation allows for a joint optimization of multiple trafic flows. Better residual energy statistics are also achieved by such joint consideration compared to independent optimization of each commodity.展开更多
Upset condition encountered by an aircraft in flight could pose great threat to flight safety, which is of chief importance in civil aviation. The causal factors have the nonlinear and multiple characteristics, and as...Upset condition encountered by an aircraft in flight could pose great threat to flight safety, which is of chief importance in civil aviation. The causal factors have the nonlinear and multiple characteristics, and as a result the conventional envelope protection system cannot successfully do with the condition. So dynamic envelope based on differential manifold theory, which can take more coupling factors into account, is proposed as a basis to design a novel envelope protection system. Then the relationship between the dynamic envelope and the control coefficient or pilot command is obtained, and the result shows that the dynamic envelope can be enlarged with the change of control coefficient. Furthermore, quantification of flight security is realized via defining relative distance between flight state and dynamic envelope, which can detect whether there is a risk for an aircraft in flight. Finally, an envelope protection system based on dynamic envelope enlargement is proposed on the basis. NASA＇s Generic Transport Model encountering hazard gust wind in climbing phase is taken as an example to verify the system＇s feasibility. The result shows that the system can give a better operation encountering upset condition and to a certain extent reduce the number of accidents or incidents.展开更多
Flexible and lightweight thermal insulation materials with hierarchical microstructures are ubiquitous in thermal management and protection systems.Ceramic aerogels promise high-temperature thermal insulation but lack...Flexible and lightweight thermal insulation materials with hierarchical microstructures are ubiquitous in thermal management and protection systems.Ceramic aerogels promise high-temperature thermal insulation but lack mechanical robustness,while the fibrous materials with excellent mechanical elasticity display modest thermal insulation.Here we describe flexible hierarchical superhydrophobic ceramic insulation nanocomposites through the densified architectured hierarchical nanostructures,radiative insulation coating,and interfacial cross-linking among composites.The lightweight flexible ceramic nanocomposites exhibit a density of 0.13 g/cm^(3),high-temperature fire resistance with thermal conductivity of 0.024 W/(m·K),and super-hydrophobicity with the water contact angle of 152°.The mechanical robustness and high-temperature thermal insulation of ceramic nanocomposites,together with its soundproof performance,shed light on the low-cost flexible insulation materials manufacturing with scalability for high-temperature thermal insulation applications under high mechanical loading conditions.展开更多
Next-generation sequencing has allowed identification of millions of somatic mutations in human cancer cells.A key challenge in interpreting cancer genomes is to distinguish drivers of cancer development among availab...Next-generation sequencing has allowed identification of millions of somatic mutations in human cancer cells.A key challenge in interpreting cancer genomes is to distinguish drivers of cancer development among available genetic mutations.To address this issue,we present the first webbased application,consensus cancer driver gene caller(C^3),to identify the consensus driver genes using six different complementary strategies,i.e.,frequency-based,machine learning-based,functional bias-based,clustering-based,statistics model-based,and network-based strategies.This application allows users to specify customized operations when calling driver genes,and provides solid statistical evaluations and interpretable visualizations on the integration results.C^3 is implemented in Python and is freely available for public use at http://drivergene.rwebox.com/c3.展开更多
Loss of control(LOC) is considered one of the leading causes of fatal aircraft accidents worldwide. Reducing LOC is critical to improve flight safety. Although it is still vaguely defined, LOC is generally associated ...Loss of control(LOC) is considered one of the leading causes of fatal aircraft accidents worldwide. Reducing LOC is critical to improve flight safety. Although it is still vaguely defined, LOC is generally associated with a flight state that is outside the safety envelope, with nonlinear influences of aircraft dynamics and incorrect handling by the flight crew. We have studied how nonlinear factors and pilot operations contribute to LOC. In this study, the stall point and bifurcation point are confirmed using the bifurcation analysis, and the results show that the aircraft will stall when excessive elevator movement is commanded. Moreover, even though there may be an equilibrium state in one of the elevator deflections, the flight state may still be outside the flight safety envelope. When the flight state is near the edge of the flight safety envelope, the strategy to regulate the elevator deflection is super-sensitive, and a slight change in the elevator deflection may contribute to a flight state outside the safety envelope. To solve this issue, the differential manifold theory is introduced to determine the safety envelope. Examples are provided using NASA's generic transport model.展开更多
Main observation and conclusion Using in situ atomic force microscopy,we visualized the oxidation dynamic process of toroidal lithium peroxide(Li_(2)O_(2))in a working Li-O2 battery and clarified the correlation betwe...Main observation and conclusion Using in situ atomic force microscopy,we visualized the oxidation dynamic process of toroidal lithium peroxide(Li_(2)O_(2))in a working Li-O2 battery and clarified the correlation between the decomposition behavior and the charging rate.It was found that at a low charge rate,the decomposition could occur at the Li_(2)O_(2)/electrolyte interface,providing strong evidence that a tiny current is allowed to pass through the bulk phase of toroidal Li_(2)O_(2).Further,the evolution of the periphery thickness,diameter and center thickness of the toroid as a function of charge capacity was quantitatively analyzed.In the early stage of charging,the diameter of the toroid radially shrinks and the shrinking rate slows down in the later stage.Besides,the periphery thickness of the toroid decreases at a faster and uniform rate,while the center thickness decreases obviously in the later stage of charging.Increasing the charging rate promotes the decomposition occurring at the Li_(2)O_(2)/electrode interface,causing direct desorption of the Li_(2)O_(2)from the electrode and irreversible capacity degradation.展开更多
Recent convergence of information communications technology and sensing equipment is creating new de- mands and opportunities for wireless sensor networks without technological restrictions, such as cyber- physical sy...Recent convergence of information communications technology and sensing equipment is creating new de- mands and opportunities for wireless sensor networks without technological restrictions, such as cyber- physical systems and internet of things. The fast-growing number of wireless sensor networks, the variety of sensors, the different granularity of time control in cyber-physical systems,展开更多
Oncogenic KRAS has been previously identified to act in a cell-intrinsic manner to modulate multiple biological functions of colorectal cancer(CRC).Here,we demonstrate a cell-extrinsic role of KRAS,where KRAS engages ...Oncogenic KRAS has been previously identified to act in a cell-intrinsic manner to modulate multiple biological functions of colorectal cancer(CRC).Here,we demonstrate a cell-extrinsic role of KRAS,where KRAS engages with the tumor microenvironment by functional reprogramming of tumor-associated macrophages(TAMs).In human CRC specimens,mutant KRAS positively correlates with the presence of TAMs.Mutationally activated KRAS in tumor cells reprograms macrophages to a TAM-like phenotype via a combination effect of tumor-derived CSF2 and lactate.In turn,KRAS-reprogrammed macrophages were shown to not only promote tumor progression but also induce the resistance of tumor cells to cetuximab therapy.Mechanistically,KRAS drives the production of CSF2 and lactate in tumor cells by stabilizing hypoxia-inducible factor-la(HIF-1a),a transcription factor that controls the expression of CSF2 and glycolytic genes.Mutant KRAS increased the production of reactive oxygen species,an inhibitor of prolyl hydroxylase activity which decreases HIF-1a hydroxylation,leading to enhanced HIF-1a stabilization.This cell-extrinsic mechanism awards KRAS a critical role in engineering a permissive microenvironment to promote tumor malignancy,and may present new insights on potential therapeutic defense strategies against mutant KRAS tumors.展开更多
Background:Patients with Crohn’s disease(CD)are often reported to be at a high risk for incisional surgical site infection(SSI).The aim of this study was to identify the risk factors associated with post-operative in...Background:Patients with Crohn’s disease(CD)are often reported to be at a high risk for incisional surgical site infection(SSI).The aim of this study was to identify the risk factors associated with post-operative incisional SSI in CD patients after bowel resection.Method:CD patients undergoing bowel resection between 2007 and 2015 were enrolled.Demographic and clinical features related to post-operative incisional SSI were analysed using both univariate and multivariate logistical analyses.Results:Of all eligible patients(n=159),123(77.4%)were male,with a mean age at surgery of 33.4611.8 years.A total of 35(22.0%)CD patients developed post-operative incisional SSI.Post-operative incisional SSI was more likely to happen in patients who had penetrating type of disease(P=0.018),underwent bowel resection for the indication of chronic fistula(P=0.005)and had an intra-operative finding of fistula(P=0.001).A greater proportion of patients with post-operative incisional SSI were found to have anemia(P=0.019)but elevated levels of white blood cells(P=0.027),neutrophils(P=0.006)as well as an elevated percentage of neutrophils(P=0.005).Multivariate logistic regression analysis showed that anemia(odds ratio[OR]:3.31,95%confidence interval[CI]:1.05-10.46,P=0.041),an elevated percentage of neutrophils(OR:2.85,95%CI:1.23-6.59,P=0.014)and an intra-operative finding of fistula(OR:3.76,95%CI:1.53-9.21,P=0.004)were significantly associated with the risk for post-operative incisional SSI.Conclusions:Anemia,elevated percentage of neutrophils and intra-operative finding of fistula are predictors for the development of post-operative incisional SSI in CD patients undergoing bowel resection.Favorable pre-operative nutrition status and low inflammatory status may lessen the incidence of post-operative incisional SSI.展开更多
文摘Harvesting energy from environmental sources such as solar and wind can mitigate or solve the limited-energy problem in wireless sensor networks. In this paper, we propose an energy-harvest-aware route-selection method that incorporates harvest availability properties and energy storage capacity limits into the routing decisions. The harvest-aware routing problem is formulated as a lin- ear program with a utility-based objective function that balances the two conflicting routing objectives of maximum total and maxi- mum minimum residual network energy. The simulation results show that doing so achieves a longer network lifetime, defined as the time-to-first-node-death in the network. Additionally, most existing energy-harvesting routing algorithms route each traffic flow independently from each other. The LP formulation allows for a joint optimization of multiple trafic flows. Better residual energy statistics are also achieved by such joint consideration compared to independent optimization of each commodity.
基金This work is supported by grants from the National Key Clinical Discipline,National Natural Science Foundation of China(No.81300367 and No.81400604)Guangdong Natural Science Foundation(No.2015A030313108)Science and Technology Planning Project of Guangdong Province(No.2015B020229001).
基金supported by National Natural Science Foundation of China(No.81400603)Guangdong Natural Science Foundation(No.2015A030310190)Science and Technology Planning Project of Guangdong Province(No.2015B020229001).
基金supported by the National Key Basic Research Program of China (No.2015CB755805)
文摘Upset condition encountered by an aircraft in flight could pose great threat to flight safety, which is of chief importance in civil aviation. The causal factors have the nonlinear and multiple characteristics, and as a result the conventional envelope protection system cannot successfully do with the condition. So dynamic envelope based on differential manifold theory, which can take more coupling factors into account, is proposed as a basis to design a novel envelope protection system. Then the relationship between the dynamic envelope and the control coefficient or pilot command is obtained, and the result shows that the dynamic envelope can be enlarged with the change of control coefficient. Furthermore, quantification of flight security is realized via defining relative distance between flight state and dynamic envelope, which can detect whether there is a risk for an aircraft in flight. Finally, an envelope protection system based on dynamic envelope enlargement is proposed on the basis. NASA＇s Generic Transport Model encountering hazard gust wind in climbing phase is taken as an example to verify the system＇s feasibility. The result shows that the system can give a better operation encountering upset condition and to a certain extent reduce the number of accidents or incidents.
基金We gratefully acknowledge support from the U.S.Department of Energy(DOE),Office of Energy Efficiency and Renewable Energy(EERE)under the Building Technology Office(BTO)Award(No.DE-EE0008675).
文摘Flexible and lightweight thermal insulation materials with hierarchical microstructures are ubiquitous in thermal management and protection systems.Ceramic aerogels promise high-temperature thermal insulation but lack mechanical robustness,while the fibrous materials with excellent mechanical elasticity display modest thermal insulation.Here we describe flexible hierarchical superhydrophobic ceramic insulation nanocomposites through the densified architectured hierarchical nanostructures,radiative insulation coating,and interfacial cross-linking among composites.The lightweight flexible ceramic nanocomposites exhibit a density of 0.13 g/cm^(3),high-temperature fire resistance with thermal conductivity of 0.024 W/(m·K),and super-hydrophobicity with the water contact angle of 152°.The mechanical robustness and high-temperature thermal insulation of ceramic nanocomposites,together with its soundproof performance,shed light on the low-cost flexible insulation materials manufacturing with scalability for high-temperature thermal insulation applications under high mechanical loading conditions.
基金This work was supported by the National Natural Science Foundation of China(No.81400603)Guangdong Natural Science Foundation(No.2015A030310190)the Science and Technology Planning Project of Guangdong Province(No.2015B020229001).
基金supported by the National Major Research and Innovation Program of China(Grant Nos.2017YFC0908500and 2016YFC1303205)National Natural Science Foundation of China(Grant No.61572361)+2 种基金Shanghai Rising-Star Program(Grant No.16QA1403900)Shanghai Natural Science Foundation Program(Grant No.17ZR1449400)Fundamental Research Funds for the Central Universities(Grant No.1501219106),China
文摘Next-generation sequencing has allowed identification of millions of somatic mutations in human cancer cells.A key challenge in interpreting cancer genomes is to distinguish drivers of cancer development among available genetic mutations.To address this issue,we present the first webbased application,consensus cancer driver gene caller(C^3),to identify the consensus driver genes using six different complementary strategies,i.e.,frequency-based,machine learning-based,functional bias-based,clustering-based,statistics model-based,and network-based strategies.This application allows users to specify customized operations when calling driver genes,and provides solid statistical evaluations and interpretable visualizations on the integration results.C^3 is implemented in Python and is freely available for public use at http://drivergene.rwebox.com/c3.
基金Project supported by the National Basic Research Program(973)of China(No.2015CB755805)the National Natural Science Foundation of China(No.61374145)
文摘Loss of control(LOC) is considered one of the leading causes of fatal aircraft accidents worldwide. Reducing LOC is critical to improve flight safety. Although it is still vaguely defined, LOC is generally associated with a flight state that is outside the safety envelope, with nonlinear influences of aircraft dynamics and incorrect handling by the flight crew. We have studied how nonlinear factors and pilot operations contribute to LOC. In this study, the stall point and bifurcation point are confirmed using the bifurcation analysis, and the results show that the aircraft will stall when excessive elevator movement is commanded. Moreover, even though there may be an equilibrium state in one of the elevator deflections, the flight state may still be outside the flight safety envelope. When the flight state is near the edge of the flight safety envelope, the strategy to regulate the elevator deflection is super-sensitive, and a slight change in the elevator deflection may contribute to a flight state outside the safety envelope. To solve this issue, the differential manifold theory is introduced to determine the safety envelope. Examples are provided using NASA's generic transport model.
基金support from the National Key R&D Program of China(Grant Nos.2016YFA0202500 and 2016YFB0100100)the National Nature Science Fund for Excellent Young Scholars(Grant No.21722508).
文摘Main observation and conclusion Using in situ atomic force microscopy,we visualized the oxidation dynamic process of toroidal lithium peroxide(Li_(2)O_(2))in a working Li-O2 battery and clarified the correlation between the decomposition behavior and the charging rate.It was found that at a low charge rate,the decomposition could occur at the Li_(2)O_(2)/electrolyte interface,providing strong evidence that a tiny current is allowed to pass through the bulk phase of toroidal Li_(2)O_(2).Further,the evolution of the periphery thickness,diameter and center thickness of the toroid as a function of charge capacity was quantitatively analyzed.In the early stage of charging,the diameter of the toroid radially shrinks and the shrinking rate slows down in the later stage.Besides,the periphery thickness of the toroid decreases at a faster and uniform rate,while the center thickness decreases obviously in the later stage of charging.Increasing the charging rate promotes the decomposition occurring at the Li_(2)O_(2)/electrode interface,causing direct desorption of the Li_(2)O_(2)from the electrode and irreversible capacity degradation.
文摘Recent convergence of information communications technology and sensing equipment is creating new de- mands and opportunities for wireless sensor networks without technological restrictions, such as cyber- physical systems and internet of things. The fast-growing number of wireless sensor networks, the variety of sensors, the different granularity of time control in cyber-physical systems,
基金This work was supported by the National Natural Science Foundation of China(81870383)Clinical Innovation Research Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2018GZR0201005)+1 种基金Science and Technology Planning Project of Guangzhou City(201804010014)the National Key R&D Program of China(2017YFC1308800).
文摘Oncogenic KRAS has been previously identified to act in a cell-intrinsic manner to modulate multiple biological functions of colorectal cancer(CRC).Here,we demonstrate a cell-extrinsic role of KRAS,where KRAS engages with the tumor microenvironment by functional reprogramming of tumor-associated macrophages(TAMs).In human CRC specimens,mutant KRAS positively correlates with the presence of TAMs.Mutationally activated KRAS in tumor cells reprograms macrophages to a TAM-like phenotype via a combination effect of tumor-derived CSF2 and lactate.In turn,KRAS-reprogrammed macrophages were shown to not only promote tumor progression but also induce the resistance of tumor cells to cetuximab therapy.Mechanistically,KRAS drives the production of CSF2 and lactate in tumor cells by stabilizing hypoxia-inducible factor-la(HIF-1a),a transcription factor that controls the expression of CSF2 and glycolytic genes.Mutant KRAS increased the production of reactive oxygen species,an inhibitor of prolyl hydroxylase activity which decreases HIF-1a hydroxylation,leading to enhanced HIF-1a stabilization.This cell-extrinsic mechanism awards KRAS a critical role in engineering a permissive microenvironment to promote tumor malignancy,and may present new insights on potential therapeutic defense strategies against mutant KRAS tumors.
基金supported by the National Natural Science Foundation of China(No.81400603)the Guangdong Natural Science Foundation(No.2015A030310190)the Science and Technology Planning Project of Guangdong Province(No.2015B020229001).
文摘Background:Patients with Crohn’s disease(CD)are often reported to be at a high risk for incisional surgical site infection(SSI).The aim of this study was to identify the risk factors associated with post-operative incisional SSI in CD patients after bowel resection.Method:CD patients undergoing bowel resection between 2007 and 2015 were enrolled.Demographic and clinical features related to post-operative incisional SSI were analysed using both univariate and multivariate logistical analyses.Results:Of all eligible patients(n=159),123(77.4%)were male,with a mean age at surgery of 33.4611.8 years.A total of 35(22.0%)CD patients developed post-operative incisional SSI.Post-operative incisional SSI was more likely to happen in patients who had penetrating type of disease(P=0.018),underwent bowel resection for the indication of chronic fistula(P=0.005)and had an intra-operative finding of fistula(P=0.001).A greater proportion of patients with post-operative incisional SSI were found to have anemia(P=0.019)but elevated levels of white blood cells(P=0.027),neutrophils(P=0.006)as well as an elevated percentage of neutrophils(P=0.005).Multivariate logistic regression analysis showed that anemia(odds ratio[OR]:3.31,95%confidence interval[CI]:1.05-10.46,P=0.041),an elevated percentage of neutrophils(OR:2.85,95%CI:1.23-6.59,P=0.014)and an intra-operative finding of fistula(OR:3.76,95%CI:1.53-9.21,P=0.004)were significantly associated with the risk for post-operative incisional SSI.Conclusions:Anemia,elevated percentage of neutrophils and intra-operative finding of fistula are predictors for the development of post-operative incisional SSI in CD patients undergoing bowel resection.Favorable pre-operative nutrition status and low inflammatory status may lessen the incidence of post-operative incisional SSI.
