Extensive research attentions have been devoted to studying cooperative cognitive radio networks(CCRNs),where secondary users(SU)providing cooperative transmissions can be permitted by primary users(PU)to use spectrum...Extensive research attentions have been devoted to studying cooperative cognitive radio networks(CCRNs),where secondary users(SU)providing cooperative transmissions can be permitted by primary users(PU)to use spectrum.In order to maximize SU’s utility,SU may transmit its own information during the period of cooperative transmission,which stimulates the use of covert transmission against PU’s monitoring.For this sake,this article reviews the motivations of studying covert communications in CCRN.In particular,three intelligent covert transmission approaches are developed for maximizing SU’s utility in CCRNs,namely,intelligent parasitic covert transmission(IPCT),intelligent jammer aided covert transmission(IJCT)and intelligent reflecting surface assisted covert transmission(IRSC).Further,some raw performance evaluations are discussed,and a range of potential research directions are also provided.展开更多
Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury,but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression i...Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury,but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression in cardiomyocytes(CMs) for driving the differentiation of cardiac stem cells(CSCs).Forced hypoxia-inducible factor 1α(HIF-1α) expression and physical hypoxia(5% O_2) treatment could induce Jagged1 expression in neonatal rat CMs. Pharmacological inhibition of HIF-1α by YC-1 attenuated hypoxia-promoted Jagged1 expression in CMs. An ERK inhibitor(PD98059), but not inhibitors of JNK(SP600125), Notch(DAPT), NF-κB(PTDC), JAK(AG490), or STAT3(Stattic) suppressed hypoxiainduced Jagged1 protein expression in CMs. c-Kit^+ CSCs isolated from neonatal rat hearts using a magnetic-activated cell sorting method expressed GATA4, SM22α or vWF, but not Nkx2.5 and cTnI.Moreover, 87.3% of freshly isolated CSCs displayed Notch1 receptor expression. Direct co-culture of CMs with BrdU-labeled CSCs enhanced CSCs differentiation, as evidenced by an increased number of BrdU^+/Nkx2.5^+ cells, while intermittent hypoxia for 21 days promoted co-culture-triggered differentiation of CSCs into CM-like cells. Notably, YC-1 and DAPT attenuated hypoxia-induced differentiation.Our results suggest that hypoxia induces Jagged1 expression in CMs primarily through ERK signaling,and facilitates early cardiac lineage differentiation of CSCs in CM/CSC co-cultures via HIF-1α/Jagged1/Notch signaling.展开更多
Antibiotics have received increasing attention due to their potential adverse effects on aquatic life and human health.How to efficiently degrade them into harmless substances is a challenging subject.Ferroelectric ma...Antibiotics have received increasing attention due to their potential adverse effects on aquatic life and human health.How to efficiently degrade them into harmless substances is a challenging subject.Ferroelectric materials with a built-in electric field can offer a strong separation ability for the photoinducedcharge pairs and are now found to be used as photocatalysts.Herein,a series of different morphologies of SrBi_(2)Ta_(2)O_(9)ferroelectric photocatalysts with high antibiotic degradation efficiency have been successfully synthesized through a molten salt method.With the addition of KCl,SrBi_(2)Ta_(2)O_(9)(SBTO 3)with exposed(001)facets shows the most excellent photocatalytic activity for decomposing tetracycline(TC)and ciprofloxacin(CIP)under visible light illumination(λ>420 nm).The rate constants of SBTO 3 for TC and CIP degradation are 1.38×10^(–1)and 4.54×10^(–2)min^(–1),which are 18 and 138 times that of the unmodified sample,respectively.The enhancement of photocatalytic performance is mainly attributed to the spontaneous polarization electric field along the[001]direction which provides a strong driven force for the separation of photoinduced charges.The KPFM results also confirm that the superior photocatalytic activity is consistent with the big large surface potential changes before and after light irradiation.The possible degradation pathways and intermediates of TC and CIP were well analyzed by DFT calculation and LC-MS.The results highlight that morphology control of the ferroelectric materials exhibits enhanced photocatalytic performance for the degradation of the antibiotic.展开更多
基金supported by the National Natural Science Foundation of China under Grant 61825104, in part by the National Natural Science Foundation of China under Grants 61801518, 62201582in part by the National Key R&D Program of China under Grant 2022YFC3301300+3 种基金in part by the Key Research and Development Program of Shaanxi under Grant 2022KW-03in part by the Young Talent fund of University Association for Science and Technology in Shaanxi under Grant 20210111in part by the Natural Science Basic Research Program of Shaanxi under Grant 2022JQ-632in part by Innovative Cultivation Project of School of Information and Communication of National University of Defense Technology under Grant YJKT-ZD-2202
文摘Extensive research attentions have been devoted to studying cooperative cognitive radio networks(CCRNs),where secondary users(SU)providing cooperative transmissions can be permitted by primary users(PU)to use spectrum.In order to maximize SU’s utility,SU may transmit its own information during the period of cooperative transmission,which stimulates the use of covert transmission against PU’s monitoring.For this sake,this article reviews the motivations of studying covert communications in CCRN.In particular,three intelligent covert transmission approaches are developed for maximizing SU’s utility in CCRNs,namely,intelligent parasitic covert transmission(IPCT),intelligent jammer aided covert transmission(IJCT)and intelligent reflecting surface assisted covert transmission(IRSC).Further,some raw performance evaluations are discussed,and a range of potential research directions are also provided.
基金supported by grants from the National Natural Science Foundation of China (Grant Nos.81170121,81460042,81541004 and 81670254)Science and Technology Project of Guangdong Province (2016A020214016)+1 种基金YangFan Plan of Guangdong Province (4YF16007G)Excellent Graduate Student Training Program of Guangdong Medical University (YS2014013)
文摘Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury,but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression in cardiomyocytes(CMs) for driving the differentiation of cardiac stem cells(CSCs).Forced hypoxia-inducible factor 1α(HIF-1α) expression and physical hypoxia(5% O_2) treatment could induce Jagged1 expression in neonatal rat CMs. Pharmacological inhibition of HIF-1α by YC-1 attenuated hypoxia-promoted Jagged1 expression in CMs. An ERK inhibitor(PD98059), but not inhibitors of JNK(SP600125), Notch(DAPT), NF-κB(PTDC), JAK(AG490), or STAT3(Stattic) suppressed hypoxiainduced Jagged1 protein expression in CMs. c-Kit^+ CSCs isolated from neonatal rat hearts using a magnetic-activated cell sorting method expressed GATA4, SM22α or vWF, but not Nkx2.5 and cTnI.Moreover, 87.3% of freshly isolated CSCs displayed Notch1 receptor expression. Direct co-culture of CMs with BrdU-labeled CSCs enhanced CSCs differentiation, as evidenced by an increased number of BrdU^+/Nkx2.5^+ cells, while intermittent hypoxia for 21 days promoted co-culture-triggered differentiation of CSCs into CM-like cells. Notably, YC-1 and DAPT attenuated hypoxia-induced differentiation.Our results suggest that hypoxia induces Jagged1 expression in CMs primarily through ERK signaling,and facilitates early cardiac lineage differentiation of CSCs in CM/CSC co-cultures via HIF-1α/Jagged1/Notch signaling.
基金financially supported by the National Key Research and Development Project of China(No.2019YFC1803404)the National Natural Science Foundation of China(No.51772325)+3 种基金the Natural Science Foundation of Guangdong Province(Nos.2021A1515010375,2021A1515010390)the Excellent Young Talents Discipline Construction Project of Jinan University(No.2019QNGG19)the Fundamental Research Funds for the Central Universities(No.21621401)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(No.2020B121201005)。
文摘Antibiotics have received increasing attention due to their potential adverse effects on aquatic life and human health.How to efficiently degrade them into harmless substances is a challenging subject.Ferroelectric materials with a built-in electric field can offer a strong separation ability for the photoinducedcharge pairs and are now found to be used as photocatalysts.Herein,a series of different morphologies of SrBi_(2)Ta_(2)O_(9)ferroelectric photocatalysts with high antibiotic degradation efficiency have been successfully synthesized through a molten salt method.With the addition of KCl,SrBi_(2)Ta_(2)O_(9)(SBTO 3)with exposed(001)facets shows the most excellent photocatalytic activity for decomposing tetracycline(TC)and ciprofloxacin(CIP)under visible light illumination(λ>420 nm).The rate constants of SBTO 3 for TC and CIP degradation are 1.38×10^(–1)and 4.54×10^(–2)min^(–1),which are 18 and 138 times that of the unmodified sample,respectively.The enhancement of photocatalytic performance is mainly attributed to the spontaneous polarization electric field along the[001]direction which provides a strong driven force for the separation of photoinduced charges.The KPFM results also confirm that the superior photocatalytic activity is consistent with the big large surface potential changes before and after light irradiation.The possible degradation pathways and intermediates of TC and CIP were well analyzed by DFT calculation and LC-MS.The results highlight that morphology control of the ferroelectric materials exhibits enhanced photocatalytic performance for the degradation of the antibiotic.
