The T2/RNase gene family is widespread in eukaryotes,and particular members of this family play critical roles in the gametophytic self-incompatibility(GSI) system in plants.Wild diploid strawberry(Fragaria)species ha...The T2/RNase gene family is widespread in eukaryotes,and particular members of this family play critical roles in the gametophytic self-incompatibility(GSI) system in plants.Wild diploid strawberry(Fragaria)species have diversified their sexual systems via self-incompatible and self-compatible traits,yet how these traits evolved in Fragaria remains elusive.By integrating the published and de novo assembled genomes and the newly generated RNA-seq data,members of the RNase T2 gene family were systematically identified in six Fragaria species,including three self-incompatible species(Fragaria nipponica,Fragaria nubicola,and Fragaria viridis) and three self-compatible species(Fragaria nilgerrensis,Fragaria vesca,and Fragaria iinumae).In total,115 RNase T2 genes were identified in the six Fragaria genomes and can be classified into three classes(Ⅰ-Ⅲ) according to phylogenetic analysis.The identified RNase T2 genes could be divided into 22 homologous gene sets according to amino acid sequence similarity and phylogenetic and syntenic relationships.We found that extensive gene loss and pseudogenization coupled with small-scale duplications mainly accounted for variations in the RNase T2 gene numbers in Fragaria.Multiple copies of homologous genes were mainly generated from tandem and segmental duplication events.Furthermore,we newly identified five S-RNase genes in three self-incompatible Fragaria genomes,including two in F.nipponica,two in F.viridis,and one in F.nubicola,which fit for typical features of a pistil determinant,including highly pistil-specific expression,highly polymorphic proteins and alkaline isoelectric point(pI),while no S-RNase genes were found in all three selfcompatible Fragaria species.Surprisingly,these T2/S-RNase genes contain at least one large intron(>10 kb).This study revealed that the rapid evolution of T2/S-RNase genes within the Fragaria genus could be associated with its sexual mode,and repeated evolution of the self-compatible traits in Fragaria was convergent via losses of S-RNase.展开更多
In this paper,three kinds of materials including graphite,titanium(Ti)and molybdenum(Mo)are used as anodes to figure out the influence factors of anode material on the characteristics of the intense electron beam diod...In this paper,three kinds of materials including graphite,titanium(Ti)and molybdenum(Mo)are used as anodes to figure out the influence factors of anode material on the characteristics of the intense electron beam diode.The results show that the characteristics of diode are mainly determined by the cathode plasma motion under a 15 mm diode gap,in which the typical electron beam parameters are 280 kV,3.5 kA.When the diode gap is reduced to 5 mm,the voltage of the electron beam reduces to about 200 kV,and its current increases to more than 8.2 kA.It is calculated that the surface temperatures of Ti and Mo anodes are higher than their melting points.The diode plasma luminescence images show that Ti and Mo anodes produce plasmas soon after the bombardment of electron beams.Ti and Mo lines are respectively found in the plasma composition of Ti and Mo anode diodes.Surface melting traces are also observed on Ti and Mo anodes by comparing the micromorphologies before and after bombardment of the electron beam.These results suggest that the time of anode plasma generation is closely related to the anode material.Compared with graphite,metal Ti and Mo anodes are more likely to produce large amounts of plasma due to their more significant temperature rise effect.According to the moment that anode plasma begins to generate,the average expansion velocities of cathode and anode plasma are estimated by fitting the improved space-charge limited flow model.This reveals that generation and motion of the anode plasma significantly affect the characteristics of intense electron beam diode.展开更多
To the editor:The impact of the coronavirus disease 2019(COVID-19)pandemic in 2020 on mental health was substantialin Chinai2and various other countries.34 Beyond the direct consequences of COVID-19,the pandemic creat...To the editor:The impact of the coronavirus disease 2019(COVID-19)pandemic in 2020 on mental health was substantialin Chinai2and various other countries.34 Beyond the direct consequences of COVID-19,the pandemic created an environment in which many determinants of mental health were affected.Issues associated with the pandemic,such as loss of livelihood,limited access to medical services,reduced social interactions,and economic downturn,could potentially have adverse effects on the population's mental well-being.5 In November 2021,the World Health Organization(WHO)designated the new variant of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),variant B.1.1.529,as a variant of concern and named it Omicron;its rapid mutation and spread raised a new global health concern.展开更多
China is now beginning its 13th five-year guideline. As the top CO2 emitter, China has recently submitted the intended nationally determined contributions and made the commitment to start reducing its total carbon emi...China is now beginning its 13th five-year guideline. As the top CO2 emitter, China has recently submitted the intended nationally determined contributions and made the commitment to start reducing its total carbon emissions in or before 2030. In this study, a bottom-up energy system model is built and applied to analyze the energy （mainly coal, oil, and gas） consumption and carbon emissions in China up to 2030. The results show that, the total energy consumption will reach a peak of 58.1 billion tonnes of standard coal and the CO2 emissions will get to 105.8 billion tonnes. Moreover, in the mitigation scenario, proportion of natural gas consumption will increase by 7 % in 2020 and 10 % in 2030, respectively. In the trans- portation sector, gasoline and diesel consumption will gradually decrease, while the consumption of natural gas in 2030 will increase by 2.7 times compared to the reference scenario. Moreover, with the promotion of electric cars, the transport electricity consumption will increase 3.1 times in 2030 compared to the reference scenario. In order to fulfill the emission peaking target, efforts should be made from both the final demand sectors and oil and gas production industries, to help adjust the energy structure and ensure the oil and gas supply in future.展开更多
Objective To analyze the upstream region of radiation-induced junB gene. Methods Four plasmids containing 250 bp, 590 bp, 900 bp and 1650 bp, and CAT reporter gene were constructed separately and introduced to L8704 c...Objective To analyze the upstream region of radiation-induced junB gene. Methods Four plasmids containing 250 bp, 590 bp, 900 bp and 1650 bp, and CAT reporter gene were constructed separately and introduced to L8704 cells. The cells were irradiated with 2 Gy X-rays and incubated at different intervals. Total RNA was extracted from the cells and fluctuation of the CAT mRNA level was assessed by the RNA ratio of CAT/β-actin measured by quantitative Northern blot hybridization. Results CAT mRNA expression containing 900 bp and 1560 bpjunB promoter remarkably and rapidly increased, and reached its peak 30min after 2 Gy X-my irradiation. Conclusions 590-900 bp fragments located in the upstream region of junB gene play an important role in the early process of cells against radiation.展开更多
Animal models of cerebral palsy established by simple infection or the hypoxia/ischemia method cannot effectively simulate the brain injury of a premature infant. Healthy 17-day-pregnant Wistar rats were intraperitone...Animal models of cerebral palsy established by simple infection or the hypoxia/ischemia method cannot effectively simulate the brain injury of a premature infant. Healthy 17-day-pregnant Wistar rats were intraperitoneally injected with lipopolysaccharide then subjected to hypoxia. The pups were used for this study at 4 weeks of age. Simultaneously, a hypoxia/ischemia group and a control group were used for comparison. The results of the footprint test, the balance beam test, the water maze test, neuroelectrophysiological examination and neuropathological examination demonstrated that, at 4 weeks after birth, footprint repeat space became larger between the forelimbs and hindlimbs of the rats, the latency period on the balance beam and in the Morris water maze was longer, place navigation and ability were poorer, and the stimulus intensity that induced the maximal wave amplitude of the compound muscle action potential was greater in the lipopolysaccharide/hypoxia and hypoxia/ischemia groups than in the control group. We observed irregular cells around the periventricular area, periventricular leukomalacia and breakage of the nuclear membrane in the lipopolysacchadde/hypexia and hypoxia/ischemia groups. These results indicate that we successfully established a Wistar rat pup model of cerebral palsy by intraperitoneal injection of lipopolysaccharide and hypoxia.展开更多
The Yes-associated protein(YAP)is a downstream effector of the Hippo pathway and acts as a key transcription co-factor to regulate cell migration,proliferation,and survival.The Hippo pathway is evolutionarily conserve...The Yes-associated protein(YAP)is a downstream effector of the Hippo pathway and acts as a key transcription co-factor to regulate cell migration,proliferation,and survival.The Hippo pathway is evolutionarily conserved and controls tissue growth and organ size.Dysregulation and heterogeneity of this pathway are found in cancers,including oral squamous cell carcinoma(OSCC),leading to overexpression of YAP and its regulated proliferation machinery.The activity of YAP is associated with its nuclear expression and is negatively regulated by the Hippo kinase-mediated phosphorylation resulting in an induction of its cytoplasmic translocation.This review focuses on the role of YAP in OSCC in the context of cancer metastatic potential and highlights the latestfindings about the heterogeneity of YAP expression and its nuclear transcription activity in oral cancer cell lines.The review also discusses the potential target of YAP in oral cancer therapy and the recentfinding of the unprecedented role of the desmosomal cadherin desmoglein-3(DSG3)in regulating Hippo-YAP signaling.展开更多
In this work,the influence of the electrode surface roughness on the self-breakdown gas switch is investigated by physical analysis,computer simulation and experiment.Cu-W electrodes of different surface roughness wer...In this work,the influence of the electrode surface roughness on the self-breakdown gas switch is investigated by physical analysis,computer simulation and experiment.Cu-W electrodes of different surface roughness were tested under the conditions of a pulse repetitive frequency of50 Hz,self-breakdown voltage of~30 kV,and peak current of~2 k A for~93000 shots(the total charge transferred was~15 C).The coefficients of variation of the self-breakdown voltage of Cu-W 0.8,Cu-W 3.2 and Cu-W 12.5 electrodes were~2.95%,~1.62%and~1.16%,respectively.With the increase of electrode roughness,the erosion area decreased continuously,indicating that the breakdown positions were more stable and the coefficient of variation of breakdown voltage decreased.The method showed that decreasing the coefficient of variation of the self-breakdown voltage by increasing the surface roughness of electrode greatly improves the stability of the self-breakdown switch,which is significant for their application in compact highpower pulse power devices over a long time with stable operation.展开更多
Background:Intensive phototherapy(IPT)and exchange transfusion(ET)are the main treatments for extreme hyperbilirubinemia.However,there is no reliable evidence on determining the thresholds for these treatments.This mu...Background:Intensive phototherapy(IPT)and exchange transfusion(ET)are the main treatments for extreme hyperbilirubinemia.However,there is no reliable evidence on determining the thresholds for these treatments.This multicenter study compared the effectiveness and complications of IPT and ET in the treatment of extreme hyperbilirubinemia.Methods:This retrospective cohort study was conducted in seven centers from January 2015 to January 2018.Patients with extreme hyperbilirubinemia that met the criteria of ET were included.Patients were divided into three subgroups(low-,medium-,and high-risk)according to gestational week and risk factors.Propensity score matching(PSM)was performed to balance the data before treatment.Study outcomes included the development of bilirubin encephalopathy,duration of hospitalization,expenses,and complications.Mortality,auditory complications,seizures,enamel dysplasia,ocular motility disorders,athetosis,motor,and language development were evaluated during follow-up at age of 3 years.Results:A total of 1164 patients were included in this study.After PSM,296 patients in the IPT only group and 296 patients in the IPT plus ET group were further divided into the low-,medium-,and high-risk subgroups with 188,364,and 40 matched patients,respectively.No significant differences were found between the IPT only and IPT plus ET groups in terms of morbidity,complications,and sequelae.Hospitalization duration and expenses were lower in the low-and medium-risk subgroups in the IPT only group.Conclusions:In this study,our results suggest that IPT is a safe and effective treatment for extreme hyperbilirubinemia.The indication of ET for patients with hyperbilirubinemia could be stricter.However,it is necessary to have a contingency plan for emergency ET as soon as IPT is commenced especially for infants with risk factors.If IPT can be guaranteed and proved to be therapeutic,ET should be avoided as much as possible.展开更多
The state-of-the-art triboelectric nanogenerators(TENGs)are constructed with synthetic polymers,curtailing their application prospects and relevance in sustainable technologies.The economically viable transformation a...The state-of-the-art triboelectric nanogenerators(TENGs)are constructed with synthetic polymers,curtailing their application prospects and relevance in sustainable technologies.The economically viable transformation and engineering of naturally abundant materials into efficient TENGs for mechanical energy harvesting is meaningful not only for fundamental scientific exploration,but also for addressing societal needs.Being an abundant natural biopolymer,chitosan enables exciting opportunity for low-cost,biodegradable TENG applications.However,the electrical outputs of chitosan-based TENGs are low compared with the devices built with synthetic polymers.Here,we explore the facile molecular surface engineering in chitosan to significantly boost the performance of chitosan-based TENG for enabling the practical applications,for example,self-powered car speed sensor.The molecular surface engineering offers a potentially promising scheme for designing and implementing high-performance biopolymer-based TENGs for selfpowered nanosystems in sustainable technologies.We further explore for the first time the feasibility of data mining approaches to analyze and learn the acquired triboelectric signals from the car speed sensors and predict the relationship between the triboelectric signals and car speed values.展开更多
基金financially supported by the National Key Research and Development Program of China (2018YFD1000107)the open research project of the "Cross-Cooperative Team" of the Germplasm Bank of Wild Species to A.Z.
文摘The T2/RNase gene family is widespread in eukaryotes,and particular members of this family play critical roles in the gametophytic self-incompatibility(GSI) system in plants.Wild diploid strawberry(Fragaria)species have diversified their sexual systems via self-incompatible and self-compatible traits,yet how these traits evolved in Fragaria remains elusive.By integrating the published and de novo assembled genomes and the newly generated RNA-seq data,members of the RNase T2 gene family were systematically identified in six Fragaria species,including three self-incompatible species(Fragaria nipponica,Fragaria nubicola,and Fragaria viridis) and three self-compatible species(Fragaria nilgerrensis,Fragaria vesca,and Fragaria iinumae).In total,115 RNase T2 genes were identified in the six Fragaria genomes and can be classified into three classes(Ⅰ-Ⅲ) according to phylogenetic analysis.The identified RNase T2 genes could be divided into 22 homologous gene sets according to amino acid sequence similarity and phylogenetic and syntenic relationships.We found that extensive gene loss and pseudogenization coupled with small-scale duplications mainly accounted for variations in the RNase T2 gene numbers in Fragaria.Multiple copies of homologous genes were mainly generated from tandem and segmental duplication events.Furthermore,we newly identified five S-RNase genes in three self-incompatible Fragaria genomes,including two in F.nipponica,two in F.viridis,and one in F.nubicola,which fit for typical features of a pistil determinant,including highly pistil-specific expression,highly polymorphic proteins and alkaline isoelectric point(pI),while no S-RNase genes were found in all three selfcompatible Fragaria species.Surprisingly,these T2/S-RNase genes contain at least one large intron(>10 kb).This study revealed that the rapid evolution of T2/S-RNase genes within the Fragaria genus could be associated with its sexual mode,and repeated evolution of the self-compatible traits in Fragaria was convergent via losses of S-RNase.
文摘In this paper,three kinds of materials including graphite,titanium(Ti)and molybdenum(Mo)are used as anodes to figure out the influence factors of anode material on the characteristics of the intense electron beam diode.The results show that the characteristics of diode are mainly determined by the cathode plasma motion under a 15 mm diode gap,in which the typical electron beam parameters are 280 kV,3.5 kA.When the diode gap is reduced to 5 mm,the voltage of the electron beam reduces to about 200 kV,and its current increases to more than 8.2 kA.It is calculated that the surface temperatures of Ti and Mo anodes are higher than their melting points.The diode plasma luminescence images show that Ti and Mo anodes produce plasmas soon after the bombardment of electron beams.Ti and Mo lines are respectively found in the plasma composition of Ti and Mo anode diodes.Surface melting traces are also observed on Ti and Mo anodes by comparing the micromorphologies before and after bombardment of the electron beam.These results suggest that the time of anode plasma generation is closely related to the anode material.Compared with graphite,metal Ti and Mo anodes are more likely to produce large amounts of plasma due to their more significant temperature rise effect.According to the moment that anode plasma begins to generate,the average expansion velocities of cathode and anode plasma are estimated by fitting the improved space-charge limited flow model.This reveals that generation and motion of the anode plasma significantly affect the characteristics of intense electron beam diode.
基金supported by the National Key Research and Development Programme of China(2020YFC2006000).
文摘To the editor:The impact of the coronavirus disease 2019(COVID-19)pandemic in 2020 on mental health was substantialin Chinai2and various other countries.34 Beyond the direct consequences of COVID-19,the pandemic created an environment in which many determinants of mental health were affected.Issues associated with the pandemic,such as loss of livelihood,limited access to medical services,reduced social interactions,and economic downturn,could potentially have adverse effects on the population's mental well-being.5 In November 2021,the World Health Organization(WHO)designated the new variant of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),variant B.1.1.529,as a variant of concern and named it Omicron;its rapid mutation and spread raised a new global health concern.
基金funded by the Project supported by China National Petroleum Corporation(Project Name:The development trend of oil and gas industry till 2030Project Number:20150114)
文摘China is now beginning its 13th five-year guideline. As the top CO2 emitter, China has recently submitted the intended nationally determined contributions and made the commitment to start reducing its total carbon emissions in or before 2030. In this study, a bottom-up energy system model is built and applied to analyze the energy （mainly coal, oil, and gas） consumption and carbon emissions in China up to 2030. The results show that, the total energy consumption will reach a peak of 58.1 billion tonnes of standard coal and the CO2 emissions will get to 105.8 billion tonnes. Moreover, in the mitigation scenario, proportion of natural gas consumption will increase by 7 % in 2020 and 10 % in 2030, respectively. In the trans- portation sector, gasoline and diesel consumption will gradually decrease, while the consumption of natural gas in 2030 will increase by 2.7 times compared to the reference scenario. Moreover, with the promotion of electric cars, the transport electricity consumption will increase 3.1 times in 2030 compared to the reference scenario. In order to fulfill the emission peaking target, efforts should be made from both the final demand sectors and oil and gas production industries, to help adjust the energy structure and ensure the oil and gas supply in future.
基金This project was supported by Japanese Research Development Corporation (JRDC).
文摘Objective To analyze the upstream region of radiation-induced junB gene. Methods Four plasmids containing 250 bp, 590 bp, 900 bp and 1650 bp, and CAT reporter gene were constructed separately and introduced to L8704 cells. The cells were irradiated with 2 Gy X-rays and incubated at different intervals. Total RNA was extracted from the cells and fluctuation of the CAT mRNA level was assessed by the RNA ratio of CAT/β-actin measured by quantitative Northern blot hybridization. Results CAT mRNA expression containing 900 bp and 1560 bpjunB promoter remarkably and rapidly increased, and reached its peak 30min after 2 Gy X-my irradiation. Conclusions 590-900 bp fragments located in the upstream region of junB gene play an important role in the early process of cells against radiation.
基金funded by the National Natural Science Foundation of China,No.30960393the Key Foundation in Science and Technology of Xinjiang Uygur Autonomous Region,No.200633128(2)+1 种基金the Youth Science and Technology Foundation of Health Department of Xinjiang Uygur Autonomous Region,No.2007Y26the Science and Technology Foundation of Health Bureau of Wuxi,No.ML201211
文摘Animal models of cerebral palsy established by simple infection or the hypoxia/ischemia method cannot effectively simulate the brain injury of a premature infant. Healthy 17-day-pregnant Wistar rats were intraperitoneally injected with lipopolysaccharide then subjected to hypoxia. The pups were used for this study at 4 weeks of age. Simultaneously, a hypoxia/ischemia group and a control group were used for comparison. The results of the footprint test, the balance beam test, the water maze test, neuroelectrophysiological examination and neuropathological examination demonstrated that, at 4 weeks after birth, footprint repeat space became larger between the forelimbs and hindlimbs of the rats, the latency period on the balance beam and in the Morris water maze was longer, place navigation and ability were poorer, and the stimulus intensity that induced the maximal wave amplitude of the compound muscle action potential was greater in the lipopolysaccharide/hypoxia and hypoxia/ischemia groups than in the control group. We observed irregular cells around the periventricular area, periventricular leukomalacia and breakage of the nuclear membrane in the lipopolysacchadde/hypexia and hypoxia/ischemia groups. These results indicate that we successfully established a Wistar rat pup model of cerebral palsy by intraperitoneal injection of lipopolysaccharide and hypoxia.
基金founded by Elfarouq Foundation(a small charity).
文摘The Yes-associated protein(YAP)is a downstream effector of the Hippo pathway and acts as a key transcription co-factor to regulate cell migration,proliferation,and survival.The Hippo pathway is evolutionarily conserved and controls tissue growth and organ size.Dysregulation and heterogeneity of this pathway are found in cancers,including oral squamous cell carcinoma(OSCC),leading to overexpression of YAP and its regulated proliferation machinery.The activity of YAP is associated with its nuclear expression and is negatively regulated by the Hippo kinase-mediated phosphorylation resulting in an induction of its cytoplasmic translocation.This review focuses on the role of YAP in OSCC in the context of cancer metastatic potential and highlights the latestfindings about the heterogeneity of YAP expression and its nuclear transcription activity in oral cancer cell lines.The review also discusses the potential target of YAP in oral cancer therapy and the recentfinding of the unprecedented role of the desmosomal cadherin desmoglein-3(DSG3)in regulating Hippo-YAP signaling.
基金Huxiang Youth Talent Support Program(No.2020RC3030)State Key Laboratory of Pulsed Power Laser Technology(No.SK2021ZR02)。
文摘In this work,the influence of the electrode surface roughness on the self-breakdown gas switch is investigated by physical analysis,computer simulation and experiment.Cu-W electrodes of different surface roughness were tested under the conditions of a pulse repetitive frequency of50 Hz,self-breakdown voltage of~30 kV,and peak current of~2 k A for~93000 shots(the total charge transferred was~15 C).The coefficients of variation of the self-breakdown voltage of Cu-W 0.8,Cu-W 3.2 and Cu-W 12.5 electrodes were~2.95%,~1.62%and~1.16%,respectively.With the increase of electrode roughness,the erosion area decreased continuously,indicating that the breakdown positions were more stable and the coefficient of variation of breakdown voltage decreased.The method showed that decreasing the coefficient of variation of the self-breakdown voltage by increasing the surface roughness of electrode greatly improves the stability of the self-breakdown switch,which is significant for their application in compact highpower pulse power devices over a long time with stable operation.
基金This work was supported by the National Science Foundation of China(Nos.81630038,81971433,81971428)the grants from the Science and Technology Bureau of Sichuan Province(Nos.2020YJ0236,2020YFS0041)+1 种基金the grant from the Ministry of Education of China(No.IRT0935)the grant of clinical discipline program(Neonatology)from the Ministry of Health of China(No.1311200003303).
文摘Background:Intensive phototherapy(IPT)and exchange transfusion(ET)are the main treatments for extreme hyperbilirubinemia.However,there is no reliable evidence on determining the thresholds for these treatments.This multicenter study compared the effectiveness and complications of IPT and ET in the treatment of extreme hyperbilirubinemia.Methods:This retrospective cohort study was conducted in seven centers from January 2015 to January 2018.Patients with extreme hyperbilirubinemia that met the criteria of ET were included.Patients were divided into three subgroups(low-,medium-,and high-risk)according to gestational week and risk factors.Propensity score matching(PSM)was performed to balance the data before treatment.Study outcomes included the development of bilirubin encephalopathy,duration of hospitalization,expenses,and complications.Mortality,auditory complications,seizures,enamel dysplasia,ocular motility disorders,athetosis,motor,and language development were evaluated during follow-up at age of 3 years.Results:A total of 1164 patients were included in this study.After PSM,296 patients in the IPT only group and 296 patients in the IPT plus ET group were further divided into the low-,medium-,and high-risk subgroups with 188,364,and 40 matched patients,respectively.No significant differences were found between the IPT only and IPT plus ET groups in terms of morbidity,complications,and sequelae.Hospitalization duration and expenses were lower in the low-and medium-risk subgroups in the IPT only group.Conclusions:In this study,our results suggest that IPT is a safe and effective treatment for extreme hyperbilirubinemia.The indication of ET for patients with hyperbilirubinemia could be stricter.However,it is necessary to have a contingency plan for emergency ET as soon as IPT is commenced especially for infants with risk factors.If IPT can be guaranteed and proved to be therapeutic,ET should be avoided as much as possible.
基金Project supported by the Key Research and Development of Science and Technology Projects of Luzhou(Special Project Fund for Emergency Research),China。
基金W.Z.W.acknowledge the College of Engineering and School of Industrial Engineering at Purdue University for the startup support and the Ravi and Eleanor Talwar Rising Star Assistant Professorship.The support provided by the China Scholarship Council(CSC)during a visit of Chenxiang Ma to Purdue University is acknowledged.
文摘The state-of-the-art triboelectric nanogenerators(TENGs)are constructed with synthetic polymers,curtailing their application prospects and relevance in sustainable technologies.The economically viable transformation and engineering of naturally abundant materials into efficient TENGs for mechanical energy harvesting is meaningful not only for fundamental scientific exploration,but also for addressing societal needs.Being an abundant natural biopolymer,chitosan enables exciting opportunity for low-cost,biodegradable TENG applications.However,the electrical outputs of chitosan-based TENGs are low compared with the devices built with synthetic polymers.Here,we explore the facile molecular surface engineering in chitosan to significantly boost the performance of chitosan-based TENG for enabling the practical applications,for example,self-powered car speed sensor.The molecular surface engineering offers a potentially promising scheme for designing and implementing high-performance biopolymer-based TENGs for selfpowered nanosystems in sustainable technologies.We further explore for the first time the feasibility of data mining approaches to analyze and learn the acquired triboelectric signals from the car speed sensors and predict the relationship between the triboelectric signals and car speed values.
