The China comprehensive inspection train(CIT)is designed for evaluating railway infrastructure to ensure safe railway operations.The CIT integrates an array of inspection devices,capable of simultaneously assessing ra...The China comprehensive inspection train(CIT)is designed for evaluating railway infrastructure to ensure safe railway operations.The CIT integrates an array of inspection devices,capable of simultaneously assessing railway health condition parameters.The CIT450,representing the second generation,can reach a top speed of 450 km/h with inspection on the infrastructure.This paper begins by outlining the global evolution of inspection trains.It then focuses on the critical technologies underlying the CIT450,which include:(1)real-time inspection data acquisition with spatial and temporal synchronization;(2)intelligent fusion and centralized management of multi-source inspection data,enabling remote supervision of the inspection process;(3)technologies in inspecting track,train–track interaction,catenary,signalling systems,and train operating environment;and(4)AI-driven analysis and correlation of inspection data.The future developmental directions for comprehensive inspection trains are discussed finally.The CIT450’s approach to real-time railway health monitoring can enrich traditional inspection means,operational,and maintenance methods by enhancing inspection efficiency and automating railway maintenance.展开更多
Practical activities are an indispensable piece of science education.As such,assessment of these practical activities is vital for continually enhancing the quality of science instruction.This article presents a tenta...Practical activities are an indispensable piece of science education.As such,assessment of these practical activities is vital for continually enhancing the quality of science instruction.This article presents a tentative framework structured for assessing practical activities in science education.The proposed framework is built upon seven components:engagement and participation,relational thinking,stepwise mastery,contextualization,multidimensional integration,empowerment,and scientific articulacy.The framework might provide science educators with an alternative lens through which to enhance the effectiveness of practical activities,promote student engagement,and better prepare learners for the future.This framework is designed to be additive and complementary to existing assessment approaches and can be adapted and customized to suit specific local contexts and varying grade levels by science educators in the pursuit of excellence in an ever-evolving science education landscape.展开更多
To develop new environmentally friendly fungicides,we designed and synthesized a novel series of D/Lconfigured camphor oxime ester derivatives based on the natural product camphor as a lead compound.We investigated th...To develop new environmentally friendly fungicides,we designed and synthesized a novel series of D/Lconfigured camphor oxime ester derivatives based on the natural product camphor as a lead compound.We investigated the in vitro antifungal activity of these compounds against six common plant pathogenic fungi.Among them,compounds B1-6,B1-17 and B2-6 displayed great in vitro activity against Rhizoctonia solani with EC50 values of 7.28,4.64,and 7.62μg/mL.The HOMO and LUMO calculations indicated that strong electronwithdrawing halogen elements exhibit better activity compared to electron-donating alkyl groups.Preliminary mechanistic studies,using SEM and TEM,indicated that compound B1-17 induced disordered entanglement of hyphae,shrinkage of hyphal surfaces,and vacuole swelling and rupture,which disrupted normal hyphal growth.Additionally,compound B1-17 induced the production and accumulation of ROS,disrupted MMP,and effectively inhibited the germination and formation of sclerotia in Rhizoctonia solani.These compounds hold potential as new antifungal agents for further research.展开更多
Dynamic tidal power is a new way of capturing tidal energy by building a water head using a dike perpendicular to the coast. This study explored the hydrodynamic mechanism of the water head across an intended dynamic ...Dynamic tidal power is a new way of capturing tidal energy by building a water head using a dike perpendicular to the coast. This study explored the hydrodynamic mechanism of the water head across an intended dynamic tidal power dike system using the Delft3 D-FLOW software module. The propagating wave was simulated in a rectangular domain with a horizontal sea bottom at a 30-m depth. A significant water head was created across the dike by blocking the water. The water head increased with increasing dike length and increasing undisturbed tidal current acceleration. The maximum water head for the dike with a length of 50 km, located 900 km from the western boundary, was 2.15 m,which exceeded the undisturbed tidal range. The time series of the water head behaved in a manner identical to the undisturbed tidal current acceleration. The distribution of the water head over the dike assumed an elliptical shape. A parasitic wave was generated at the attachment and scattered outward. The phase lag across the dike did not behave as a linear function of the detour distance.展开更多
Well-crystalline CeO_2 nanowires were prepared via a surfactant-assisted hydrothermal process.Reaction temperature and reaction time were changed for the determination of optimal synthesis parameters.The as-obtained p...Well-crystalline CeO_2 nanowires were prepared via a surfactant-assisted hydrothermal process.Reaction temperature and reaction time were changed for the determination of optimal synthesis parameters.The as-obtained products were characterized by X-ray diffraction （XRD）,high-resolution transmission electron microscopy（HRTEM）,and field emission scanning electron microscopy（FESEM）.The results show that single crystal CeO_2 nanowires with high yield and good uniformity can be obtained hydrothermally at 180℃for 12 h with the aid of 2.0 g surfactant（polyvinyl pyrrolidone,PVP）.The role of PVP was then discussed and a possible growth mechanism was proposed. Moreover,room temperature photoluminescence（PL） spectra were obtained for these CeO2 nanowires,which are believed to be related to the abundant defects in these nanostructures.展开更多
During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella caus...During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella cause a male infertility syndrome,multiple morphological abnormalities of the flagella(MMAF),while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential.However,evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited.Here,we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38(Ccdc38)via inducing a nonsense mutation and find that the males are infertile.The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes.We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm.Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3,a protein associated with acrosome biogenesis,in testes and an aberrant distribution of TEKT3 in sperm.We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility.Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.展开更多
Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1%of azoospermia or severe oligospermia.However,the underlying mechanisms of pathogenesis and...Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1%of azoospermia or severe oligospermia.However,the underlying mechanisms of pathogenesis and etiologies are still largely unknown.Herein,we investigated apparently balanced interchromosomal structural rearrangements in six cases with azoospermia/severe oligospermia to comprehensively identify and delineate cryptic structural rearrangements and the related copy number variants.In addition,high read-depth genome sequencing(GS)(30-fold)was performed to investigate point mutations causative of male infertility.Mate-pair GS(4-fold)revealed additional structural rearrangements and/or copy number changes in 5 of 6 cases and detected a total of 48 rearrangements.Overall,the breakpoints caused truncations of 30 RefSeq genes,five of which were associated with spermatogenesis.Furthermore,the breakpoints disrupted 43 topological-associated domains.Direct disruptions or potential dysregulations of genes,which play potential roles in male germ cell development,apoptosis,and spermatogenesis,were found in all cases(n=6).In addition,high read-depth GS detected dual molecular findings in case MI6,involving a complex rearrangement and two point mutations in the gene DNAH1.Overall,our study provided the molecular characteristics of apparently balanced interchromosomal structural rearrangements in patients with male infertility.We demonstrated the complexity of chromosomal structural rearrangements,potential gene disruptions/dysregulation and single-gene mutations could be the contributing mechanisms underlie male infertility.展开更多
The cyanine dyes represented by IR780 can achieve synergistic photodynamic therapy(PDT)and photothermal therapy(PTT)under the stimulation of near-infrared(NIR)light(commonly 808 nm).Unfortunately,the stability of NIR-...The cyanine dyes represented by IR780 can achieve synergistic photodynamic therapy(PDT)and photothermal therapy(PTT)under the stimulation of near-infrared(NIR)light(commonly 808 nm).Unfortunately,the stability of NIR-excited cyanine dyes is not satisfactory.These cyanine dyes can be attacked by self-generated reactive oxygen species(ROS)during PDT processes,resulting in structural damage and rapid degradation,which is fatal for phototherapy.To address this issue,a novel non-cyanine dye(IR890)was elaborately designed and synthesized by our team.The maximum absorption wavelength of IR890 was located in the deep NIR region(ca.890 nm),which was beneficial for further improving tissue penetration depth.Importantly,IR890 exhibited good stability when continuously illuminated by deep NIR light.To improve the hydrophilicity and biocompatibility,the hydrophobic IR890 dye was grafted onto the side chain of hydrophilic polymer(POEGMA-b-PGMA-g-C≡CH)via click chemistry.Then,the synthesized POEGMA-b-PGMA-g-IR890 amphiphilic polymerwas utilized to prepare P-IR890 nano-photosensitizer via self-assembly method.Under irradiation with deep NIR light(850 nm,0.5 W/cm^(2),10 min),the dye degradation rate of P-IR890 was less than 5%.However,IR780 was almost completely degraded with the same light output power density and irradiation duration.In addition,P-IR890 could stably generate a large number of ROS and heat at the same time.It was rarely reported that the stable synergistic combination therapy of PDT and PTT could be efficiently performed by a single photosensitizer via irradiation with deep NIR light.P-IR890 exhibited favorable anti-tumor outcomes through apoptosis pathway.Therefore,the P-IR890 could provide a new insight into the design of photosensitizers and new opportunities for synergistic combination therapy of PDT and PTT.展开更多
A simple synthetic approach for the transformation of （S）-Ugi＇s amine, another configuration of （R）-Ugi＇s amine, one of the most widely used intermediate in the preparation of chiral ferrocene-based ligands, has...A simple synthetic approach for the transformation of （S）-Ugi＇s amine, another configuration of （R）-Ugi＇s amine, one of the most widely used intermediate in the preparation of chiral ferrocene-based ligands, has been developed via esterification using anhydride, alkaline hydrolysis and active manganese dioxide oxidation, and the corresponding ferrocenyl ketone was afforded in good yields.展开更多
A three-dimensional Direct numerical simulation(DNS)with complex chemistry was employed to examine the statistical behavior of turbulent kinetic energy(TKE)and enstrophy transport equations in hydrogen(Lewis number(Le...A three-dimensional Direct numerical simulation(DNS)with complex chemistry was employed to examine the statistical behavior of turbulent kinetic energy(TKE)and enstrophy transport equations in hydrogen(Lewis number(Le)≈0.4)and dodecane(Le≈4.2)flames.The Karlovitz(Ka)numbers ranged from 4 to 150,involving both the thin and broken reaction zones.Budget analyses of TKE and enstrophy transport equations are performed,and scaling terms in the literature are re-examined.Similar to thin reaction zone flames,viscous dissipation term appears to be the most important term in the TKE balance,while viscous dissipation and vortex-stretching terms are the dominant terms in the enstrophy transport equation at high Ka number.The velocity-pressure gradient and the mean velocity dilatation in the TKE transport equation and the dilatation term in enstrophy budget are found to be affected by the Le.Modified scaling estimations for those terms affected by Le are proposed in this work to account for the Le effects spanning different combustion regimes.This work confirmed that Kolmogorov’s first hypothesis is not valid for low Ka number flames investigated in this study,where the vortex stretching and viscous dissipation terms cannot be scaled with local dissipation and viscosity.At sufficiently high Ka number flames,the vorticity can be scaled with the Kolmogorov time scale,and the mean enstrophy value approaches homogeneous,isotropic,non-reacting turbulence flow,but lower Le fuels require much higher Ka number to achieve that.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52272427)the Technology Research and Development Program of China National Railway Group(Grant No.K2021T015)Development Plan of China Academy of Railway Sciences Corporation Ltd.(Grant No.2022YJ256)。
文摘The China comprehensive inspection train(CIT)is designed for evaluating railway infrastructure to ensure safe railway operations.The CIT integrates an array of inspection devices,capable of simultaneously assessing railway health condition parameters.The CIT450,representing the second generation,can reach a top speed of 450 km/h with inspection on the infrastructure.This paper begins by outlining the global evolution of inspection trains.It then focuses on the critical technologies underlying the CIT450,which include:(1)real-time inspection data acquisition with spatial and temporal synchronization;(2)intelligent fusion and centralized management of multi-source inspection data,enabling remote supervision of the inspection process;(3)technologies in inspecting track,train–track interaction,catenary,signalling systems,and train operating environment;and(4)AI-driven analysis and correlation of inspection data.The future developmental directions for comprehensive inspection trains are discussed finally.The CIT450’s approach to real-time railway health monitoring can enrich traditional inspection means,operational,and maintenance methods by enhancing inspection efficiency and automating railway maintenance.
基金supported by the Scientific Research Program of Hefei Normal University(2024KY71)the Partnership Program of Hefei Normal University(HXXM2022094).
文摘Practical activities are an indispensable piece of science education.As such,assessment of these practical activities is vital for continually enhancing the quality of science instruction.This article presents a tentative framework structured for assessing practical activities in science education.The proposed framework is built upon seven components:engagement and participation,relational thinking,stepwise mastery,contextualization,multidimensional integration,empowerment,and scientific articulacy.The framework might provide science educators with an alternative lens through which to enhance the effectiveness of practical activities,promote student engagement,and better prepare learners for the future.This framework is designed to be additive and complementary to existing assessment approaches and can be adapted and customized to suit specific local contexts and varying grade levels by science educators in the pursuit of excellence in an ever-evolving science education landscape.
基金the Fundamental Research Funds for the Central Universities(KYCYXT2022011,KJYQ2024014)the National Key Research and Development Program of China(2021YFD1700102)for the generous financial support for our programs.
文摘To develop new environmentally friendly fungicides,we designed and synthesized a novel series of D/Lconfigured camphor oxime ester derivatives based on the natural product camphor as a lead compound.We investigated the in vitro antifungal activity of these compounds against six common plant pathogenic fungi.Among them,compounds B1-6,B1-17 and B2-6 displayed great in vitro activity against Rhizoctonia solani with EC50 values of 7.28,4.64,and 7.62μg/mL.The HOMO and LUMO calculations indicated that strong electronwithdrawing halogen elements exhibit better activity compared to electron-donating alkyl groups.Preliminary mechanistic studies,using SEM and TEM,indicated that compound B1-17 induced disordered entanglement of hyphae,shrinkage of hyphal surfaces,and vacuole swelling and rupture,which disrupted normal hyphal growth.Additionally,compound B1-17 induced the production and accumulation of ROS,disrupted MMP,and effectively inhibited the germination and formation of sclerotia in Rhizoctonia solani.These compounds hold potential as new antifungal agents for further research.
基金supported by the National Key R&D Program of China(Grant No.2017YFC1404200)the National Natural Science Foundation of China(Grants No.51520105014 and 51509168)the National Special Funds for Basic Scientific Research for Research Institutes(Grant No.Y218008)
文摘Dynamic tidal power is a new way of capturing tidal energy by building a water head using a dike perpendicular to the coast. This study explored the hydrodynamic mechanism of the water head across an intended dynamic tidal power dike system using the Delft3 D-FLOW software module. The propagating wave was simulated in a rectangular domain with a horizontal sea bottom at a 30-m depth. A significant water head was created across the dike by blocking the water. The water head increased with increasing dike length and increasing undisturbed tidal current acceleration. The maximum water head for the dike with a length of 50 km, located 900 km from the western boundary, was 2.15 m,which exceeded the undisturbed tidal range. The time series of the water head behaved in a manner identical to the undisturbed tidal current acceleration. The distribution of the water head over the dike assumed an elliptical shape. A parasitic wave was generated at the attachment and scattered outward. The phase lag across the dike did not behave as a linear function of the detour distance.
基金supported by the National Natural Science Foundation of China(Nos.50901074 and 50672001)the Young Teacher Natural Science Fund of Anhui Province,China(No.2008jq1002).
文摘Well-crystalline CeO_2 nanowires were prepared via a surfactant-assisted hydrothermal process.Reaction temperature and reaction time were changed for the determination of optimal synthesis parameters.The as-obtained products were characterized by X-ray diffraction （XRD）,high-resolution transmission electron microscopy（HRTEM）,and field emission scanning electron microscopy（FESEM）.The results show that single crystal CeO_2 nanowires with high yield and good uniformity can be obtained hydrothermally at 180℃for 12 h with the aid of 2.0 g surfactant（polyvinyl pyrrolidone,PVP）.The role of PVP was then discussed and a possible growth mechanism was proposed. Moreover,room temperature photoluminescence（PL） spectra were obtained for these CeO2 nanowires,which are believed to be related to the abundant defects in these nanostructures.
基金supported by the National Key Research and Development Program of China(2021YFC2701400)in part by the National Natural Science Foundation of China(32000393 and 32288101).
文摘During spermiogenesis,haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes,which are required for successful fertilization.Severe deformities in flagella cause a male infertility syndrome,multiple morphological abnormalities of the flagella(MMAF),while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential.However,evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited.Here,we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38(Ccdc38)via inducing a nonsense mutation and find that the males are infertile.The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes.We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm.Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3,a protein associated with acrosome biogenesis,in testes and an aberrant distribution of TEKT3 in sperm.We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility.Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.
基金supported by the National Natural Science Foundation of China(No.31801042)the Health and Medical Research Fund(No.04152666 and No.07180576)General Research Fund(No.14115418),and Direct Grant(No.2020.052).
文摘Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1%of azoospermia or severe oligospermia.However,the underlying mechanisms of pathogenesis and etiologies are still largely unknown.Herein,we investigated apparently balanced interchromosomal structural rearrangements in six cases with azoospermia/severe oligospermia to comprehensively identify and delineate cryptic structural rearrangements and the related copy number variants.In addition,high read-depth genome sequencing(GS)(30-fold)was performed to investigate point mutations causative of male infertility.Mate-pair GS(4-fold)revealed additional structural rearrangements and/or copy number changes in 5 of 6 cases and detected a total of 48 rearrangements.Overall,the breakpoints caused truncations of 30 RefSeq genes,five of which were associated with spermatogenesis.Furthermore,the breakpoints disrupted 43 topological-associated domains.Direct disruptions or potential dysregulations of genes,which play potential roles in male germ cell development,apoptosis,and spermatogenesis,were found in all cases(n=6).In addition,high read-depth GS detected dual molecular findings in case MI6,involving a complex rearrangement and two point mutations in the gene DNAH1.Overall,our study provided the molecular characteristics of apparently balanced interchromosomal structural rearrangements in patients with male infertility.We demonstrated the complexity of chromosomal structural rearrangements,potential gene disruptions/dysregulation and single-gene mutations could be the contributing mechanisms underlie male infertility.
基金This project was supported by National Natural Science Foundation of China(Grant No.82271629 and 82301790)Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(Grant No.2023R01002)Ningbo Natural Science Foundation(Grant No.2023J054).
文摘The cyanine dyes represented by IR780 can achieve synergistic photodynamic therapy(PDT)and photothermal therapy(PTT)under the stimulation of near-infrared(NIR)light(commonly 808 nm).Unfortunately,the stability of NIR-excited cyanine dyes is not satisfactory.These cyanine dyes can be attacked by self-generated reactive oxygen species(ROS)during PDT processes,resulting in structural damage and rapid degradation,which is fatal for phototherapy.To address this issue,a novel non-cyanine dye(IR890)was elaborately designed and synthesized by our team.The maximum absorption wavelength of IR890 was located in the deep NIR region(ca.890 nm),which was beneficial for further improving tissue penetration depth.Importantly,IR890 exhibited good stability when continuously illuminated by deep NIR light.To improve the hydrophilicity and biocompatibility,the hydrophobic IR890 dye was grafted onto the side chain of hydrophilic polymer(POEGMA-b-PGMA-g-C≡CH)via click chemistry.Then,the synthesized POEGMA-b-PGMA-g-IR890 amphiphilic polymerwas utilized to prepare P-IR890 nano-photosensitizer via self-assembly method.Under irradiation with deep NIR light(850 nm,0.5 W/cm^(2),10 min),the dye degradation rate of P-IR890 was less than 5%.However,IR780 was almost completely degraded with the same light output power density and irradiation duration.In addition,P-IR890 could stably generate a large number of ROS and heat at the same time.It was rarely reported that the stable synergistic combination therapy of PDT and PTT could be efficiently performed by a single photosensitizer via irradiation with deep NIR light.P-IR890 exhibited favorable anti-tumor outcomes through apoptosis pathway.Therefore,the P-IR890 could provide a new insight into the design of photosensitizers and new opportunities for synergistic combination therapy of PDT and PTT.
基金financial support from the National Natural Science Foundation of China (No.20972123)Wuhan Science and Technology Bureau
文摘A simple synthetic approach for the transformation of （S）-Ugi＇s amine, another configuration of （R）-Ugi＇s amine, one of the most widely used intermediate in the preparation of chiral ferrocene-based ligands, has been developed via esterification using anhydride, alkaline hydrolysis and active manganese dioxide oxidation, and the corresponding ferrocenyl ketone was afforded in good yields.
基金supported by the National Natural Science Foundation of China(Grant Nos.91752201 and 11672123)Shenzhen Science and Technology Program(Grant Nos.JCYJ20170412151759222,JCYJ20180302173952945,and KQTD20180411143441009)+1 种基金Department of Science and Technology of Guangdong Province(Grant No.2019B21203001)Project No.LCH-2019011 under the Joint Program of Shenzhen Clean Energy Research Institute and SUSTech through contract CERI-KY-2019-003.
文摘A three-dimensional Direct numerical simulation(DNS)with complex chemistry was employed to examine the statistical behavior of turbulent kinetic energy(TKE)and enstrophy transport equations in hydrogen(Lewis number(Le)≈0.4)and dodecane(Le≈4.2)flames.The Karlovitz(Ka)numbers ranged from 4 to 150,involving both the thin and broken reaction zones.Budget analyses of TKE and enstrophy transport equations are performed,and scaling terms in the literature are re-examined.Similar to thin reaction zone flames,viscous dissipation term appears to be the most important term in the TKE balance,while viscous dissipation and vortex-stretching terms are the dominant terms in the enstrophy transport equation at high Ka number.The velocity-pressure gradient and the mean velocity dilatation in the TKE transport equation and the dilatation term in enstrophy budget are found to be affected by the Le.Modified scaling estimations for those terms affected by Le are proposed in this work to account for the Le effects spanning different combustion regimes.This work confirmed that Kolmogorov’s first hypothesis is not valid for low Ka number flames investigated in this study,where the vortex stretching and viscous dissipation terms cannot be scaled with local dissipation and viscosity.At sufficiently high Ka number flames,the vorticity can be scaled with the Kolmogorov time scale,and the mean enstrophy value approaches homogeneous,isotropic,non-reacting turbulence flow,but lower Le fuels require much higher Ka number to achieve that.
