In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical s...In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating points.With a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.展开更多
Bear bile has been a valuable and effective medicinal material in traditional Chinese medicine(TCM)for over 13 centuries.However,the current practice of obtaining it through bear farming is under scrutiny for its adve...Bear bile has been a valuable and effective medicinal material in traditional Chinese medicine(TCM)for over 13 centuries.However,the current practice of obtaining it through bear farming is under scrutiny for its adverse impact on bear welfare.Here,we present a new approach for creating artificial bear bile(ABB)as a high-quality and sustainable alternative to natural bear bile.This study addresses the scientific challenges of creating bear bile alternatives through interdisciplinary collaborations across various fields,including resources,chemistry,biology,medicine,pharmacology,and TCM.A comprehensive efficacy assessment system that bridges the gap between TCM and modern medical terminology has been established,allowing for the systematic screening of therapeutic constituents.Through the utilization of chemical synthesis and enzyme engineering technologies,our research has achieved the environmentally friendly,large-scale production of bear bile therapeutic compounds,as well as the optimization and recomposition of ABB formulations.The resulting ABB not only closely resembles natural bear bile in its composition but also offers advantages such as consistent product quality,availability of raw materials,and independence from threatened or wild resources.Comprehensive preclinical efficacy evaluations have demonstrated the equivalence of the therapeutic effects from ABB and those from commercially available drained bear bile(DBB).Furthermore,preclinical toxicological assessment and phase I clinical trials show that the safety of ABB is on par with that of the currently used DBB.This innovative strategy can serve as a new research paradigm for developing alternatives for other endangered TCMs,thereby strengthening the integrity and sustainability of TCM.展开更多
To accommodate the diversified emerging use cases in 5G,radio access networks(RAN)is required to be more flexible,open,and versatile.It is evolving towards cloudification,intelligence and openness.By embedding computi...To accommodate the diversified emerging use cases in 5G,radio access networks(RAN)is required to be more flexible,open,and versatile.It is evolving towards cloudification,intelligence and openness.By embedding computing capabilities within RAN,it helps to transform RAN into a natural cost effective radio edge computing platform,offering great opportunity to further enhance RAN agility for diversified services and improve users’quality of experience(Qo E).In this article,a logical architecture enabling deep convergence of communication and computing in RAN is proposed based on O-RAN.The scenarios and potential benefits of sharing RAN computing resources are first analyzed.Then,the requirements,design principles and logical architecture are introduced.Involved key technologies are also discussed,including heterogeneous computing infrastructure,unified computing and communication task modeling,joint communication and computing orchestration and RAN computing data routing.Followed by that,a VR use case is studied to illustrate the superiority of the joint communication and computing optimization.Finally,challenges and future trends are highlighted to provide some insights on the potential future work for researchers in this field.展开更多
[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation techno...[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation technology,and the volatile components of different components of molecular distillation were analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)technology.Human liver carcinoma cells(HepG2),human breast cancer cells(MCF-7),and human cervical cancer cells(Hela)were selected as the tumor cell lines to be tested,and the cell viability was detected by the MTT assay.[Results]Molecular distillation effectively reduced small molecular substances produced by oil oxidation in G.lucidum spore oil,such as heptanal,octanal,linalool,hexanal,E-2-octanal,3-ethylpyridine,etc.Among the heavy components,the content of esters was relatively high,mainly including ethyl levulinate,ethyl crotonate,and amyl butyrate.The MTT cytotoxicity test indicated that G.lucidum spore oil and its molecular distillation components had certain inhibitory effects on the growth of three tumor cells,and G.lucidum spore oil crude oil had the most significant antitumor activity.G.lucidum spore oil crude oil,heavy component,and light component had the most significant antitumor activity on HepG2 cells,followed by MCF-7 cells,and the weakest antitumor activity on Hela cells.The quality of G.lucidum spore oil became higher after molecular distillation,and the rancid smell was reduced,and molecular distillation had little effect on the antitumor activity of G.lucidum spores.[Conclusions]Molecular distillation technology can be applied to the refining of G.lucidum spore oil to improve product quality.展开更多
With the 5th Generation(5G)Mobile network being rolled out gradually in 2019,the research for the next generation mobile network has been started and targeted for 2030.To pave the way for the development of the 6th Ge...With the 5th Generation(5G)Mobile network being rolled out gradually in 2019,the research for the next generation mobile network has been started and targeted for 2030.To pave the way for the development of the 6th Generation(6G)mobile network,the vision and requirements should be identified first for the potential key technology identification and comprehensive system design.This article first identifies the vision of the society development towards 2030 and the new application scenarios for mobile communication,and then the key performance requirements are derived from the service and application perspective.Taken into account the convergence of information technology,communication technology and big data technology,a logical mobile network architecture is proposed to resolve the lessons from 5G network design.To compromise among the cost,capability and flexibility of the network,the features of the 6G mobile network are proposed based on the latest progress and applications of the relevant fields,namely,on-demand fulfillment,lite network,soft network,native AI and native security.Ultimately,the intent of this article is to serve as a basis for stimulating more promising research on 6G.展开更多
With the large-scale commercial launch of fifth generation(5G)mobile network,the development of new services and applications catering to the year 2030,along with the deep convergence of information,communication,and ...With the large-scale commercial launch of fifth generation(5G)mobile network,the development of new services and applications catering to the year 2030,along with the deep convergence of information,communication,and data technologies(ICDT),and the lessons and experiences from 5G practice will drive the evolution of the next generation of mobile networks.This article surveys the history and driving forces of the evolution of the mobile network architecture and proposes a logical function architecture for sixth generation(6G)mobile network.The proposed 6G network architecture is termed SOLIDS(related to the following basic features:soft,on-demand fulfillment,lite,native intelligence,digital twin,and native security),which can support self-generation,self-healing,self-evolution,and self-immunity without human involvement and address the primary issues in the legacy 5G network(e.g.,high cost,high power consumption,and highly complicated operation and maintenance),significantly well.展开更多
The sixth generation(6G)mobile network is envisaged to be commercially deployed around 2030,which will profoundly change people's lifestyles and accelerate the digitalization of society.To ensure that the requirem...The sixth generation(6G)mobile network is envisaged to be commercially deployed around 2030,which will profoundly change people's lifestyles and accelerate the digitalization of society.To ensure that the requirements of 6G can be achieved,it is essential to establish a set of key performance indicators(KPIs).This paper comprehensively assesses the KPIs not only from the service requirements but also from the technical feasibility points of view.Specifically,theoretical derivations of KPIs have been clarified,and numerical evaluations have been conducted with reasonable technical assumptions.Evaluation results show that some KPIs defined from the service requirements can be improved through advanced technologies while some are still challenging for practical implementations,such as Tbps-level peak data rate and 0.1 ms user plane latency.In addition,it is also necessary to comply with multiple KPIs for some cases.Furthermore,based on the technical analysis,the potential enabling technologies are outlined and foreseeable implementation challenges as well as possible solutions are presented,which promotes a more reasonable design for 6G mobile network.展开更多
The Fe-based ionic liquid doped g-C_3N_4(Fee CN) photocatalyst was firstly prepared base on ultrathin g-C_3N_4 obtained by multiple calcination method with a metal-based reactive ionic liquid [Omim]FeCl_4 for the degr...The Fe-based ionic liquid doped g-C_3N_4(Fee CN) photocatalyst was firstly prepared base on ultrathin g-C_3N_4 obtained by multiple calcination method with a metal-based reactive ionic liquid [Omim]FeCl_4 for the degradation of Rhodamine B(RhB). Experimental results revealed that Fe3+species were doped into the framework of g-C_3N_4. The effect of the amount of Fe-doping on the catalytic activity was performed. The result showed that the Fee CN could effectively degrade RhB under the condition of visible light irradiation. The photocurrent analysis showed that the incorporation of Fe^(3+)into g-C_3N_4 material could accelerate the separation of the photogenerated carriers significantly.At the same time, the reactive species generated during the photodegradation process were tested by radicals trapping experiments and electron spin resonance(ESR). It was proposed that the synergistic effect of■ and ·OH contributed to degrade RhB efficiently.展开更多
Visible light communications(VLC)is considered as an effective supplement technology for next-generation(6G)communications due to its abundant spectrum,high power efficiency and easy deployment.Optical orthogonal freq...Visible light communications(VLC)is considered as an effective supplement technology for next-generation(6G)communications due to its abundant spectrum,high power efficiency and easy deployment.Optical orthogonal frequency division multiplexing(O-OFDM)is a common technology to obtain further promotion.In this paper,two typical O-OFDM schemes direct current biased O-OFDM(DCO-OFDM)and asymmetrically clipped O-OFDM(ACO-OFDM)are analyzed in terms of signal clipping at both transmitter and receiver under the constraints of maximum optical power and non-negative optical power.And effective electrical SNR models after signal clipping are proposed and verified by link simulation.Then a noise cancellation scheme is proposed based on received signal clipping and is proved to bring a significant gain for ACO-OFDM.By system simulation,we find that under a certain optical power limitation,most users can achieve above 4 Gbps in indoor scenario when modulation bandwidth of the light emit diode(LED)or laser diode(LD)is 1 GHz.Therefore,it can be expected that the throughput could reach tens Gbps when the LED/LD modulation bandwidth is increased and multiple LEDs/LDs are deployed.展开更多
The fast deployment and penetration of 4G has cultivated human behaviors on mobile data consumption, leading to explosive growth in mobile traffic and stimulating new requirements on the capabilities of mobile network...The fast deployment and penetration of 4G has cultivated human behaviors on mobile data consumption, leading to explosive growth in mobile traffic and stimulating new requirements on the capabilities of mobile networks. To meet the requirements of mobile networks toward year 2020, the next genera- tion of mobile networks (termed as IMT-2020, or 5G) is designed to support 100 Mbps-1 Gbps user-experienced data rate, 1 ms radio transmission latency, and 1 million connec- tions per square kilometer. Recalling the vision and requirements of 5G targeting for commer- cial launch in 2020, this article overviews the key features of 5G and compares with those of 4G, and reports the world first field trials conducted to validate the key performance of 5G radio interface in 3.SGHz band. The trial results show that a 1 ms transmission latency and 1 Gbps data rate are achievable.展开更多
The aim of this study was to analyze the combination of three kinds of in-house IFN-γ ELISPOT using peptide A53 and peptide mixtures (E6 + E7 and E6 + E7 + C14) with tuberculin skin test (TST) to detect latent TB inf...The aim of this study was to analyze the combination of three kinds of in-house IFN-γ ELISPOT using peptide A53 and peptide mixtures (E6 + E7 and E6 + E7 + C14) with tuberculin skin test (TST) to detect latent TB infection (LTBI) in China. A total of 788 healthy people were recruited and analyzed by three kinds of IFN-g ELISPOT, 581 of them had TST results, of which 147 samples were also compared with the T- SPOT.TB test. The positive detection rates for T- SPOT.TB and three kinds of IFN-γ ELISPOT with A53, E6 + E7 and E6 + E7 + C14 were 14.28% (21/147), 29.43% (171/581), 23.24% (135/581) and 28.40% (165/581), respectively. These results were significantly lower than the positive TST results, which were positive in 82.99% (122/147) and 75.73% (440/ 581), respectively. The positive detection rates of three kinds of IFN-γ ELISPOT (31.60%, 26.65% and 32.11% in 788 cases, respectively) could better reflect over 40.00% of Mycobacterium tuberculosis (MTB) infection rate in China. Detection rates between contacts and non-contacts by three kinds of IFN-γ ELIS-POT were not significantly different (p > 0.05). It can be seen that the three kinds of in-house IFN-γ ELIS- POT might be used as a complementary tool of T- SPOT.TB for detecting LTBI in the healthy population of China.展开更多
Centromeres play a vital role in cellular division by facilitating kinetochore assembly and spindle attachments.Despite their conserved functionality,centromeric DNA sequences exhibit rapid evolution,presenting divers...Centromeres play a vital role in cellular division by facilitating kinetochore assembly and spindle attachments.Despite their conserved functionality,centromeric DNA sequences exhibit rapid evolution,presenting diverse sizes and compositions across species.The functional significance of rye centromeric DNA sequences,particularly in centromere identity,remains unclear.In this study,we comprehensively characterized the sequence composition and organization of rye centromeres.Our findings revealed that these centromeres are primarily composed of long terminal repeat retrotransposons(LTR-RTs)and interspersed minisatellites.We systematically classified LTR-RTs into five categories,highlighting the prevalence of younger CRS1,CRS2,and CRS3 of CRSs(centromeric retrotransposons of Secale cereale)were primarily located in the core centromeres and exhibited a higher association with CENH3 nucleosomes.The minisatellites,mainly derived from retrotransposons,along with CRSs,played a pivotal role in establishing functional centromeres in rye.Additionally,we observed the formation of R-loops at specific regions of CRS1,CRS2,and CRS3,with both rye pericentromeres and centromeres exhibiting enrichment in R-loops.Notably,these R-loops selectively formed at binding regions of the CENH3 nucleosome in rye centromeres,suggesting a potential role in mediating the precise loading of CENH3 to centromeres and contributing to centromere specification.Our work provides insights into the DNA sequence composition,distribution,and potential function of R-loops in rye centromeres.This knowledge contributes valuable information to understanding the genetics and epigenetics of rye centromeres,offering implications for the development of synthetic centromeres in future plant modifications and beyond.展开更多
Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat...Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains elusive.Here,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid wheat.We found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome.To investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors.We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat.Furthermore,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger LTR.Collectively,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.展开更多
The Triticum-Aegilops complex groups demonstrated high cross-affinity with each other to overcome the barriers of distant hybridization(Loureiro et al.,2023).Distant hybridization involves two distinct yet closely rel...The Triticum-Aegilops complex groups demonstrated high cross-affinity with each other to overcome the barriers of distant hybridization(Loureiro et al.,2023).Distant hybridization involves two distinct yet closely related events:hybridization and genome doubling.Previous studies have indicated that bursts of transposable elements(TEs)can occur as a consequence or concomitant to hybridization or genome duplication(Parisod et al.,2010).This raises an important scientific question regarding how the TEs-rich centromere region copes with genomic shock(McClintock,1984).The Triticum-Aegilops species complexes,particularly in the F1,So,and subsequent early generations resulting from successive selfcrossing,offer an opportunity to investigate whether the centromere environment undergoes reconstruction and the associated mechanisms that maintain genomic stability.展开更多
Cadaverine is the key monomer for the synthesis of nylon 5X.Efficient and alkaline stable lysine decarboxylases are highly desirable for cadaverine production as the reaction pH increasing from 6.3 to 8.5.However,the ...Cadaverine is the key monomer for the synthesis of nylon 5X.Efficient and alkaline stable lysine decarboxylases are highly desirable for cadaverine production as the reaction pH increasing from 6.3 to 8.5.However,the most studied lysine decarboxylase CadA(E.coli)lost almost all activity at pH 8.0,which is the foremost challenge for the industrial-cadaverine production.In this study,we first found that the Na^(+)-microenvironment significantly improved the alkaline stability of the disulfide engineered lysine decarboxylaseΔLdcEt3(P233C/L628C)(half-life 362 h),compared to the conventional buffer(half-life 0.66 h)at pH 8.0.Meanwhile,the whole-cell conversion efficiency of the industrial-grade L-lysine withΔLdcEt3 could reach up to 99%in 2 h in the fermenter.Experi-mental investigation and molecular dynamics confirmed that Na^(+)-microenvironment could improve active-aggregation state and affect secondary structure ofΔLdcEt3.Therefore,Na^(+)-microenvironment stabilizesΔLdcEt3 providing a great potential industrial application for high-level cadaverine production.展开更多
文摘In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating points.With a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.
基金supported by the Major Program of National Natural Science Foundation of China(T2192970-T2192974)the CAMS Innovation Fund for Medical Sciences(CIFMS,2021-I2M-1-027).
文摘Bear bile has been a valuable and effective medicinal material in traditional Chinese medicine(TCM)for over 13 centuries.However,the current practice of obtaining it through bear farming is under scrutiny for its adverse impact on bear welfare.Here,we present a new approach for creating artificial bear bile(ABB)as a high-quality and sustainable alternative to natural bear bile.This study addresses the scientific challenges of creating bear bile alternatives through interdisciplinary collaborations across various fields,including resources,chemistry,biology,medicine,pharmacology,and TCM.A comprehensive efficacy assessment system that bridges the gap between TCM and modern medical terminology has been established,allowing for the systematic screening of therapeutic constituents.Through the utilization of chemical synthesis and enzyme engineering technologies,our research has achieved the environmentally friendly,large-scale production of bear bile therapeutic compounds,as well as the optimization and recomposition of ABB formulations.The resulting ABB not only closely resembles natural bear bile in its composition but also offers advantages such as consistent product quality,availability of raw materials,and independence from threatened or wild resources.Comprehensive preclinical efficacy evaluations have demonstrated the equivalence of the therapeutic effects from ABB and those from commercially available drained bear bile(DBB).Furthermore,preclinical toxicological assessment and phase I clinical trials show that the safety of ABB is on par with that of the currently used DBB.This innovative strategy can serve as a new research paradigm for developing alternatives for other endangered TCMs,thereby strengthening the integrity and sustainability of TCM.
基金supported by the National Natural Science Foundation of China(81303182,81173523)the National Major Scientific and Technological Special Project for“Significant New Drugs Development”(2018ZX09734-002).
基金jointly supported by the Beijing University of Posts and Telecommunications-China Mobile Research Institute Joint Innovation Centerthe National Key Research and Development Program of China under Grant 2021YFB2900200the National Natural Science Foundation of China under Grant 62201073 and 61925101。
文摘To accommodate the diversified emerging use cases in 5G,radio access networks(RAN)is required to be more flexible,open,and versatile.It is evolving towards cloudification,intelligence and openness.By embedding computing capabilities within RAN,it helps to transform RAN into a natural cost effective radio edge computing platform,offering great opportunity to further enhance RAN agility for diversified services and improve users’quality of experience(Qo E).In this article,a logical architecture enabling deep convergence of communication and computing in RAN is proposed based on O-RAN.The scenarios and potential benefits of sharing RAN computing resources are first analyzed.Then,the requirements,design principles and logical architecture are introduced.Involved key technologies are also discussed,including heterogeneous computing infrastructure,unified computing and communication task modeling,joint communication and computing orchestration and RAN computing data routing.Followed by that,a VR use case is studied to illustrate the superiority of the joint communication and computing optimization.Finally,challenges and future trends are highlighted to provide some insights on the potential future work for researchers in this field.
基金Supported by Taishan Industrial Leading Talent Project(Efficient Ecological Agriculture Innovation)(LJNY202105)。
文摘[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation technology,and the volatile components of different components of molecular distillation were analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)technology.Human liver carcinoma cells(HepG2),human breast cancer cells(MCF-7),and human cervical cancer cells(Hela)were selected as the tumor cell lines to be tested,and the cell viability was detected by the MTT assay.[Results]Molecular distillation effectively reduced small molecular substances produced by oil oxidation in G.lucidum spore oil,such as heptanal,octanal,linalool,hexanal,E-2-octanal,3-ethylpyridine,etc.Among the heavy components,the content of esters was relatively high,mainly including ethyl levulinate,ethyl crotonate,and amyl butyrate.The MTT cytotoxicity test indicated that G.lucidum spore oil and its molecular distillation components had certain inhibitory effects on the growth of three tumor cells,and G.lucidum spore oil crude oil had the most significant antitumor activity.G.lucidum spore oil crude oil,heavy component,and light component had the most significant antitumor activity on HepG2 cells,followed by MCF-7 cells,and the weakest antitumor activity on Hela cells.The quality of G.lucidum spore oil became higher after molecular distillation,and the rancid smell was reduced,and molecular distillation had little effect on the antitumor activity of G.lucidum spores.[Conclusions]Molecular distillation technology can be applied to the refining of G.lucidum spore oil to improve product quality.
文摘With the 5th Generation(5G)Mobile network being rolled out gradually in 2019,the research for the next generation mobile network has been started and targeted for 2030.To pave the way for the development of the 6th Generation(6G)mobile network,the vision and requirements should be identified first for the potential key technology identification and comprehensive system design.This article first identifies the vision of the society development towards 2030 and the new application scenarios for mobile communication,and then the key performance requirements are derived from the service and application perspective.Taken into account the convergence of information technology,communication technology and big data technology,a logical mobile network architecture is proposed to resolve the lessons from 5G network design.To compromise among the cost,capability and flexibility of the network,the features of the 6G mobile network are proposed based on the latest progress and applications of the relevant fields,namely,on-demand fulfillment,lite network,soft network,native AI and native security.Ultimately,the intent of this article is to serve as a basis for stimulating more promising research on 6G.
基金the National Key Research and Development Program of China(2020YFB1806800).
文摘With the large-scale commercial launch of fifth generation(5G)mobile network,the development of new services and applications catering to the year 2030,along with the deep convergence of information,communication,and data technologies(ICDT),and the lessons and experiences from 5G practice will drive the evolution of the next generation of mobile networks.This article surveys the history and driving forces of the evolution of the mobile network architecture and proposes a logical function architecture for sixth generation(6G)mobile network.The proposed 6G network architecture is termed SOLIDS(related to the following basic features:soft,on-demand fulfillment,lite,native intelligence,digital twin,and native security),which can support self-generation,self-healing,self-evolution,and self-immunity without human involvement and address the primary issues in the legacy 5G network(e.g.,high cost,high power consumption,and highly complicated operation and maintenance),significantly well.
文摘The sixth generation(6G)mobile network is envisaged to be commercially deployed around 2030,which will profoundly change people's lifestyles and accelerate the digitalization of society.To ensure that the requirements of 6G can be achieved,it is essential to establish a set of key performance indicators(KPIs).This paper comprehensively assesses the KPIs not only from the service requirements but also from the technical feasibility points of view.Specifically,theoretical derivations of KPIs have been clarified,and numerical evaluations have been conducted with reasonable technical assumptions.Evaluation results show that some KPIs defined from the service requirements can be improved through advanced technologies while some are still challenging for practical implementations,such as Tbps-level peak data rate and 0.1 ms user plane latency.In addition,it is also necessary to comply with multiple KPIs for some cases.Furthermore,based on the technical analysis,the potential enabling technologies are outlined and foreseeable implementation challenges as well as possible solutions are presented,which promotes a more reasonable design for 6G mobile network.
基金the financial support from the National Natural Science Foundation of China(No.21722604,21576122)Chinese Postdoctoral Science Foundation(No.2017M611726)
文摘The Fe-based ionic liquid doped g-C_3N_4(Fee CN) photocatalyst was firstly prepared base on ultrathin g-C_3N_4 obtained by multiple calcination method with a metal-based reactive ionic liquid [Omim]FeCl_4 for the degradation of Rhodamine B(RhB). Experimental results revealed that Fe3+species were doped into the framework of g-C_3N_4. The effect of the amount of Fe-doping on the catalytic activity was performed. The result showed that the Fee CN could effectively degrade RhB under the condition of visible light irradiation. The photocurrent analysis showed that the incorporation of Fe^(3+)into g-C_3N_4 material could accelerate the separation of the photogenerated carriers significantly.At the same time, the reactive species generated during the photodegradation process were tested by radicals trapping experiments and electron spin resonance(ESR). It was proposed that the synergistic effect of■ and ·OH contributed to degrade RhB efficiently.
文摘Visible light communications(VLC)is considered as an effective supplement technology for next-generation(6G)communications due to its abundant spectrum,high power efficiency and easy deployment.Optical orthogonal frequency division multiplexing(O-OFDM)is a common technology to obtain further promotion.In this paper,two typical O-OFDM schemes direct current biased O-OFDM(DCO-OFDM)and asymmetrically clipped O-OFDM(ACO-OFDM)are analyzed in terms of signal clipping at both transmitter and receiver under the constraints of maximum optical power and non-negative optical power.And effective electrical SNR models after signal clipping are proposed and verified by link simulation.Then a noise cancellation scheme is proposed based on received signal clipping and is proved to bring a significant gain for ACO-OFDM.By system simulation,we find that under a certain optical power limitation,most users can achieve above 4 Gbps in indoor scenario when modulation bandwidth of the light emit diode(LED)or laser diode(LD)is 1 GHz.Therefore,it can be expected that the throughput could reach tens Gbps when the LED/LD modulation bandwidth is increased and multiple LEDs/LDs are deployed.
基金supported in part by national Key Project (2016ZX03001021)
文摘The fast deployment and penetration of 4G has cultivated human behaviors on mobile data consumption, leading to explosive growth in mobile traffic and stimulating new requirements on the capabilities of mobile networks. To meet the requirements of mobile networks toward year 2020, the next genera- tion of mobile networks (termed as IMT-2020, or 5G) is designed to support 100 Mbps-1 Gbps user-experienced data rate, 1 ms radio transmission latency, and 1 million connec- tions per square kilometer. Recalling the vision and requirements of 5G targeting for commer- cial launch in 2020, this article overviews the key features of 5G and compares with those of 4G, and reports the world first field trials conducted to validate the key performance of 5G radio interface in 3.SGHz band. The trial results show that a 1 ms transmission latency and 1 Gbps data rate are achievable.
文摘The aim of this study was to analyze the combination of three kinds of in-house IFN-γ ELISPOT using peptide A53 and peptide mixtures (E6 + E7 and E6 + E7 + C14) with tuberculin skin test (TST) to detect latent TB infection (LTBI) in China. A total of 788 healthy people were recruited and analyzed by three kinds of IFN-g ELISPOT, 581 of them had TST results, of which 147 samples were also compared with the T- SPOT.TB test. The positive detection rates for T- SPOT.TB and three kinds of IFN-γ ELISPOT with A53, E6 + E7 and E6 + E7 + C14 were 14.28% (21/147), 29.43% (171/581), 23.24% (135/581) and 28.40% (165/581), respectively. These results were significantly lower than the positive TST results, which were positive in 82.99% (122/147) and 75.73% (440/ 581), respectively. The positive detection rates of three kinds of IFN-γ ELISPOT (31.60%, 26.65% and 32.11% in 788 cases, respectively) could better reflect over 40.00% of Mycobacterium tuberculosis (MTB) infection rate in China. Detection rates between contacts and non-contacts by three kinds of IFN-γ ELIS-POT were not significantly different (p > 0.05). It can be seen that the three kinds of in-house IFN-γ ELIS- POT might be used as a complementary tool of T- SPOT.TB for detecting LTBI in the healthy population of China.
基金supported by the National Natural Science Foundation of China(31991212,31920103006)。
文摘Centromeres play a vital role in cellular division by facilitating kinetochore assembly and spindle attachments.Despite their conserved functionality,centromeric DNA sequences exhibit rapid evolution,presenting diverse sizes and compositions across species.The functional significance of rye centromeric DNA sequences,particularly in centromere identity,remains unclear.In this study,we comprehensively characterized the sequence composition and organization of rye centromeres.Our findings revealed that these centromeres are primarily composed of long terminal repeat retrotransposons(LTR-RTs)and interspersed minisatellites.We systematically classified LTR-RTs into five categories,highlighting the prevalence of younger CRS1,CRS2,and CRS3 of CRSs(centromeric retrotransposons of Secale cereale)were primarily located in the core centromeres and exhibited a higher association with CENH3 nucleosomes.The minisatellites,mainly derived from retrotransposons,along with CRSs,played a pivotal role in establishing functional centromeres in rye.Additionally,we observed the formation of R-loops at specific regions of CRS1,CRS2,and CRS3,with both rye pericentromeres and centromeres exhibiting enrichment in R-loops.Notably,these R-loops selectively formed at binding regions of the CENH3 nucleosome in rye centromeres,suggesting a potential role in mediating the precise loading of CENH3 to centromeres and contributing to centromere specification.Our work provides insights into the DNA sequence composition,distribution,and potential function of R-loops in rye centromeres.This knowledge contributes valuable information to understanding the genetics and epigenetics of rye centromeres,offering implications for the development of synthetic centromeres in future plant modifications and beyond.
基金supported by the National Natural Science Foundation of China(31991212)the National Key Research and Development Program of China(2022YFF1003303)。
文摘Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains elusive.Here,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid wheat.We found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome.To investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors.We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat.Furthermore,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger LTR.Collectively,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.
基金the National Natural Science Foundation of China(31991212)the National Key Research and Development Program of China(2022YFF1003303).
文摘The Triticum-Aegilops complex groups demonstrated high cross-affinity with each other to overcome the barriers of distant hybridization(Loureiro et al.,2023).Distant hybridization involves two distinct yet closely related events:hybridization and genome doubling.Previous studies have indicated that bursts of transposable elements(TEs)can occur as a consequence or concomitant to hybridization or genome duplication(Parisod et al.,2010).This raises an important scientific question regarding how the TEs-rich centromere region copes with genomic shock(McClintock,1984).The Triticum-Aegilops species complexes,particularly in the F1,So,and subsequent early generations resulting from successive selfcrossing,offer an opportunity to investigate whether the centromere environment undergoes reconstruction and the associated mechanisms that maintain genomic stability.
基金supported by the National Natural Science Foundation of China (grant number 22078346)Beijing Nova Program of Science and Technology (Z201100006820141)+4 种基金Innovation Academy for Green Manufacture, CAS (IAGM2020C19)Natural Science Foundation of Beijing (2204097)Henan Key Research and Development Project (202102210046)Hebei Provincial Natural Science Foundation (B2020103010)the CAS Pioneer Hundred Program。
文摘Cadaverine is the key monomer for the synthesis of nylon 5X.Efficient and alkaline stable lysine decarboxylases are highly desirable for cadaverine production as the reaction pH increasing from 6.3 to 8.5.However,the most studied lysine decarboxylase CadA(E.coli)lost almost all activity at pH 8.0,which is the foremost challenge for the industrial-cadaverine production.In this study,we first found that the Na^(+)-microenvironment significantly improved the alkaline stability of the disulfide engineered lysine decarboxylaseΔLdcEt3(P233C/L628C)(half-life 362 h),compared to the conventional buffer(half-life 0.66 h)at pH 8.0.Meanwhile,the whole-cell conversion efficiency of the industrial-grade L-lysine withΔLdcEt3 could reach up to 99%in 2 h in the fermenter.Experi-mental investigation and molecular dynamics confirmed that Na^(+)-microenvironment could improve active-aggregation state and affect secondary structure ofΔLdcEt3.Therefore,Na^(+)-microenvironment stabilizesΔLdcEt3 providing a great potential industrial application for high-level cadaverine production.