Edge caching has emerged as a promising application paradigm in 5G networks,and by building edge networks to cache content,it can alleviate the traffic load brought about by the rapid growth of Internet of Things(IoT)...Edge caching has emerged as a promising application paradigm in 5G networks,and by building edge networks to cache content,it can alleviate the traffic load brought about by the rapid growth of Internet of Things(IoT)services and applications.Due to the limitations of Edge Servers(ESs)and a large number of user demands,how to make the decision and utilize the resources of ESs are significant.In this paper,we aim to minimize the total system energy consumption in a heterogeneous network and formulate the content caching optimization problem as a Mixed Integer Non-Linear Programming(MINLP).To address the optimization problem,a Deep Q-Network(DQN)-based method is proposed to improve the overall performance of the system and reduce the backhaul traffic load.In addition,the DQN-based method can effectively solve the limitation of traditional reinforcement learning(RL)in complex scenarios.Simulation results show that the proposed DQN-based method can greatly outperform other benchmark methods,and significantly improve the cache hit rate and reduce the total system energy consumption in different scenarios.展开更多
Gas explosions are one of the most lethal types of coal mine safety accidents.The powerful shock waves these explosions produce can cause damage to the lung tissue of nearby individuals,resulting in symptoms including...Gas explosions are one of the most lethal types of coal mine safety accidents.The powerful shock waves these explosions produce can cause damage to the lung tissue of nearby individuals,resulting in symptoms including pulmonary hemorrhage and pulmonary edema[1].At present,there is no effective treatment for gas explosion-induced lung injuries;therefore,there is an urgent need to identify new therapeutic means to improve the clinical management of the system of treatment for lung injury caused by gas explosions.Mesenchymal stem cells(MSCs)are adult stem cells with self-renewal ability and multilineage differentiation potential that exert their therapeutic potential through various mechanisms,including the regulation of inflammation and immune responses[2].Reports on the therapeutic role of MSCs in blast lung injury remain scarce.展开更多
Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of appl...Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass （BG） before, after, and during 35% hydrogen peroxide （HP） bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups： distilled deionized water （DDW）, BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order： group HP〉 BG before HP, BG after HP〉 BG during HP〉DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.展开更多
Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathoge...Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathogen races. In this study, a new resistance gene against Pst race CYR34 was identified and predicted using the descendants of a cross between AS1676, a highly resistant Chinese landrace, and Avocet S, a susceptible cultivar. From a heterozygous plant from a F7recombinant inbred line(RIL) population lacking the Yr18 gene, a near-isogenic line(NIL) population was developed to map the resistance gene. An allstage resistance gene, YrAS1676, was identified on chromosome arm 1AL via bulked-segregant exomecapture sequencing. By analyzing a large NIL population consisting of 6537 plants, the gene was further mapped to the marker interval between KA1A_485.36 and KA1A_490.13, spanning 485.36–490.13 Mb on1AL. A total of 66 annotated genes have been reported in this region. To characterize and predict the candidate gene(s), an RNA-seq was performed using NIL-R and NIL-S seedlings 3 days after CYR34 inoculation. Compared to NIL-S plants, NIL-R plants showed stronger immune reaction and higher expression levels of genes encoding pathogenesis-associated proteins. These differences may help to explain why NIL-R plants were more resistant to Pst race CYR34 than NIL-S plants. By combining fine-mapping and transcriptome sequencing, a calcium-dependent protein kinase gene was finally predicted as the potential candidate gene of YrAS1676. This gene contained a single-nucleotide polymorphism. The candidate gene was more highly expressed in NIL-R than in NIL-S plants. In field experiments with Pst challenge,the YrAS1676 genotype showed mitigation of disease damage and yield loss without adverse effects on tested agronomic traits. These results suggest that YrAS1676 has potential use in wheat stripe rust resistance breeding.展开更多
In the current study,we sought to investigate whether T-type Ca^(2+)channels(TCCs)in the brain are involved in generating post-anesthetic hyperexcitatory behaviors(PAHBs).We found that younger rat pups(postnatal days ...In the current study,we sought to investigate whether T-type Ca^(2+)channels(TCCs)in the brain are involved in generating post-anesthetic hyperexcitatory behaviors(PAHBs).We found that younger rat pups(postnatal days 9-11)had a higher incidence of PAHBs and higher PAHB scores than older pups(postnatal days16-18)during emergence from sevoflurane anesthesia.The power spectrum of the theta oscillations(4 Hz-8 Hz)in the prefrontal cortex was significantly enhanced in younger pups when PAHBs occurred,while there were no significant changes in older pups.Both the power of theta oscillations and the level of PAHBs were significantly reduced by the administration of TCC inhibitors.Moreover,the sensitivity of TCCs in the medial dorsal thalamic nucleus to sevoflurane was found to increase with age by investigating the kinetic properties of TCCs in vitro.TCCs were activated by potentiated GABAergic depolarization with a sub-anesthetic dose of sevoflurane(1%).These data suggest that(1)TCCs in the brain contribute to the generation of PAHBs and the concomitant electroencephalographic changes;(2)the stronger inhibitory effect of sevoflurane contributes to the lack of PAHBs in older rats;and(3)the contribution of TCCs to PAHBs is not mediated by a direct effect of sevoflurane on TCCs.展开更多
Multiple growth factors（e.g., BMP2, TGF-b1, FGF2） and isolated genes have been shown to improve osteoblastic proliferation and mineralization, advancing bone tissue engineering. Among these factors, both polydopamin...Multiple growth factors（e.g., BMP2, TGF-b1, FGF2） and isolated genes have been shown to improve osteoblastic proliferation and mineralization, advancing bone tissue engineering. Among these factors, both polydopamine（PDA） and dopamine（DA） monomer have recently been reported to increase osteoblast proliferation and mineralization in vitro. Although a well-characterized neurotransmitter, DA＇s role in the bone is unknown. We hypothesize that DA can directly act on osteoblasts, and examined whether osteoblasts express DA receptors that respond to exogenous DA. m RNAs and protein cell lysates were obtained from MC3T3-E1 cells during osteogenic differentiation phase. Reverse transcription polymerase chain reaction and western blot analysis were used to examine the expression of DA receptors, D1–D5. Dose-response effect and time course of DA treatment on cell proliferation, mineralization, and osteogenic differentiation were investigated at pre-determined days. Real-time PCR was performed to investigate whether DA affects osteogenic gene expression（ALP, BSP, OC, OSX, RUNX2, and Collagen1a2） with or without receptor antagonists（SCH233390 and GR103691）. Two-way ANOVA was used for statistical analysis. All five DA receptors（D1, D2, D3, D4, and D5） m RNAs and proteins were expressed in MC3T3-E1 cells. DA treatment increased cell proliferation for up to 7 days（P, 0.05）. Osteogenic mineralization was significantly greater in the DA-treated group than control group（P, 0.05）. Finally, expression of all the osteogenic genes was inhibited by DA receptor antagonists for D1, D3, and D5. Our findings suggest that MC3T3-E1 osteoblasts express functional DA receptors that enhance proliferation and mineralization. PDA is not biologically inert and has important implications in orthopedic applications. Furthermore, osteoblast differentiation might be regulated by the nervous system, presumably during bone development, remodeling, or repair.展开更多
Plants have evolved a sophisticated chemical defense network to counteract pathogens,with phenolamides and salicylic acid(SA)playing pivotal roles in the immune response.However,the synergistic regulatory mechanisms o...Plants have evolved a sophisticated chemical defense network to counteract pathogens,with phenolamides and salicylic acid(SA)playing pivotal roles in the immune response.However,the synergistic regulatory mechanisms of their biosynthesis remain to be explored.Here,we identified a biosynthetic gene cluster on chromosome 2(BGC2)associated with the biosynthesis of phenolamide and SA,wherein the key component SlEPS1 exhibits dual catalytic functions for the synthesis of phenolamides and SA.Overexpression of the key component SlEPS1 of BGC2 in tomato enhanced resistance to the bacterial pathogen Pst DC3000,whereas knockout plants were more susceptible.Exogenous applications of SA and phenolamides revealed that these two compounds act synergistically to enhance plant resistance.Notably,during tomato domestication,a disease-resistant allele of SlEPS1,SlEPS1HapB,was subject to negative selection,leading to a reduction in phenolamide and SA levels and compromised disease resistance in modern varieties.Moreover,the SlMYB78 directly regulates the BGC2 gene cluster to enhance phenolamide and SA biosynthesis,modulating resistance to Pst DC3000.Our study employed multi-omics approaches to describe the synergistic regulation of phenolamide and SA biosynthesis,offering new insights into the complexity of plant immune-related metabolism.展开更多
Among plant metabolites,phenolamides,which are conjugates of hydroxycinnamic acid derivatives and polyamines,play important roles in plant adaptation to abiotic and biotic stresses.However,the molecular mechanisms und...Among plant metabolites,phenolamides,which are conjugates of hydroxycinnamic acid derivatives and polyamines,play important roles in plant adaptation to abiotic and biotic stresses.However,the molecular mechanisms underlying phenolamide metabolism and regulation as well as the effects of domestication and breeding on phenolamide diversity in tomato remain largely unclear.In this study,we performed a metabolite-based genome-wide association study and identified two biosynthetic gene clusters(BGC7 and BGC11)containing 12 genes involved in phenolamide metabolism,including four biosynthesis genes(two 4CL genes,one C3H gene,and one CPA gene),seven decoration genes(five AT genes and two UGT genes),and one transport protein gene(DTX29).Using gene co-expression network analysis we further discovered that SlMYB13 positively regulates the expression of two gene clusters,thereby promoting phenolamide accumulation.Genetic and physiological analyses showed that BGC7,BGC11 and SlMYB13 enhance drought tolerance by enhancing scavenging of reactive oxygen species and increasing abscisic acid content in tomato.Natural variation analysis suggested that BGC7,BGC11 and SlMYB13 were negatively selected during tomato domestication and improvement,leading to reduced phenolamide content and drought tolerance of cultivated tomato.Collectively,our study discovers a key mechanism of phenolamide biosynthesis and regulation in tomato and reveals that crop domestication and improvement shapes metabolic diversity to affect plant environmental adaptation.展开更多
This manuscript focuses on bone repair/regeneration using tissue engineering strategies, and highlights nanobiotechnology developments leading to novel nanocomposite systems. About 6.5 million fractures occur annually...This manuscript focuses on bone repair/regeneration using tissue engineering strategies, and highlights nanobiotechnology developments leading to novel nanocomposite systems. About 6.5 million fractures occur annually in USA, and about 550,000 of these individual cases required the application of a bone graft. Autogenous and allogenous bone have been most widely used for bone graft based therapies; however, there are significant problems such as donor shortage and risk of infection. Alternatives using synthetic and natural biomaterials have been developed, and some are commercially available for clinical applications requiring bone grafts. However, it remains a great challenge to design an ideal synthetic graft that very closely mimics the bone tissue structurally, and can modulate the desired function in osteoblast and progenitor cell populations. Nanobiomaterials, specifically nanocomposites composed of hydroxyapatite （HA） and/or collagen are extremely promising graft substitutes. The biocomposites can be fabricated to mimic the material composition of native bone tissue, and additionally, when using nano-HA （reduced grain size）, one mimics the structural arrangement of native bone. A good understanding of bone biology and structure is critical to development of bone mimicking graft substitutes. HA and collagen exhibit excellent osteoconductive properties which can further modulate the regenerative/ healing process following fracture injury. Combining with other polymeric biomaterials will reinforce the mechanical properties thus making the novel nano-HA based composites comparable to human bone. We report on recent studies using nanocomposites that have been fabricated as particles and nanofibers for regeneration of segmental bone defects. The research in nanocomposites, highlight a pivotal role in the future development of an ideal orthopaedic implant device, however further significant advancements are necessary to achieve clinical use.展开更多
Graphene resting on a silicon-on-insulator platform offers great potential for optoelectronic devices.In the paper,we demonstrate all-optical modulation on the graphene-silicon hybrid waveguides(GSHWs)with tens of mic...Graphene resting on a silicon-on-insulator platform offers great potential for optoelectronic devices.In the paper,we demonstrate all-optical modulation on the graphene-silicon hybrid waveguides(GSHWs)with tens of micrometers in length.Owing to strong interaction between graphene and silicon strip waveguides with compact light confinement,the modulation depth reaches 22.7%with a saturation threshold down to 1.38 pJ per pulse and a 30-μm-long graphene pad.A response time of 1.65 ps is verified by a pump-probe measurement with an energy consumption of 2.1 pJ.The complementary metal-oxide semiconductor compatible GSHWs with the strip configuration exhibit great potential for ultrafast and broadband all-optical modulation,indicating that employing two-dimensional materials has become a complementary technology to promote the silicon photonic platform.展开更多
Volumetric muscle loss(VML)injuries characterized by critical loss of skeletal muscle tissues result in severe functional impairment.Current treatments involving use of muscle grafts are limited by tissue availability...Volumetric muscle loss(VML)injuries characterized by critical loss of skeletal muscle tissues result in severe functional impairment.Current treatments involving use of muscle grafts are limited by tissue availability and donor site morbidity.In this study,we designed and synthesized an implantable glycosaminoglycan-based hydrogel system consisting of thiolated hyaluronic acid(HA)and thiolated chondroitin sulfate(CS)cross-linked with poly(ethylene glycol)diacrylate to promote skeletal muscle regeneration of VML injuries in mice.The HA-CS hydrogels were optimized with suitable biophysical properties by fine-tuning degree of thiol group substitution to support C2C12 myoblast proliferation,myogenic differentiation and expression of myogenic markers MyoD,MyoG and MYH8.Furthermore,in vivo studies using a murine quadriceps VML model demonstrated that the HA-CS hydrogels supported integration of implants with the surrounding host tissue and facilitated migration of Pax7+satellite cells,de novo myofiber formation,angiogenesis,and innervation with minimized scar tissue formation during 4-week implantation.The hydrogel-treated and autograft-treated mice showed similar functional improvements in treadmill performance as early as 1-week post-implantation compared to the untreated groups.Taken together,our results demonstrate the promise of HA-CS hydrogels as regenerative engineering matrices to accelerate healing of skeletal muscle injuries.展开更多
Plant interphase cortical microtubules(cMTs)mediate anisotropic cell expansion in response to environmental and developmental cues.In Arabidopsis thaliana,KATANIN 1(KTN1),the p60 catalytic subunit of the conserved MT-...Plant interphase cortical microtubules(cMTs)mediate anisotropic cell expansion in response to environmental and developmental cues.In Arabidopsis thaliana,KATANIN 1(KTN1),the p60 catalytic subunit of the conserved MT-severing enzyme katanin,is essential for cMT ordering and anisotropic cell expansion.However,the regulation of KTN1-mediated cMT severing and ordering remains unclear.In this work,we report that the Arabidopsis IQ67 DOMAIN(IQD)family gene ABNORMAL SHOOT 6(ABS6)encodes a MT-associated protein.Overexpression of ABS6 leads to elongated cotyledons,directional pavement cell expansion,and highly ordered transverse cMT arrays.Genetic suppressor analysis revealed that ABS6-mediated cMT ordering is dependent on KTN1 and SHADE AVOIDANCE 4(SAV4).Live imaging of cMT dynamics showed that both ABS6 and SAV4 function as positive regulators of cMT severing.Furthermore,ABS6 directly interacts with KTN1 and SAV4 and promotes their recruitment to the cMTs.Finally,analysis of loss-of-function mutant combinations showed that ABS6,SAV4,and KTN1 work together to ensure the robust ethylene response in the apical hook of dark-grown seedlings.Together,our findings establish ABS6 and SAV4 as positive regulators of cMT severing and ordering,and highlight the role of cMT dynamics in fine-tuning differential growth in plants.展开更多
Formic acid oxidation(FAO)is a typical anode reaction in fuel cells that can be facilitated by modulating its direct and indirect reaction pathways.Herein,PtAu bimetallic nanoparticles loaded onto Co and N co-doping c...Formic acid oxidation(FAO)is a typical anode reaction in fuel cells that can be facilitated by modulating its direct and indirect reaction pathways.Herein,PtAu bimetallic nanoparticles loaded onto Co and N co-doping carbon nanoframes(CoNC NFs)were designed to improve the selectivity of the direct reaction pathway for efficient FAO.Based on these subtle nanomaterials,the influences of elemental composition and carbon-support materials on the two pathways of FAO were investigated in detail.The results of fuel cell tests verified that the appropriate amount of Au in PtAu/CoNC can promote a direct reaction pathway for FAO,which is crucial for enhancing the oxidation efficiency of formic acid.In particular,the obtained PtAu/CoNC with an optimal Pt/Au atomic ratio of 1:1(PtAu/CoNC-3)manifests the best catalytic performance among the analogous obtained Pt-based electrocatalysts.The FAO mass activity of the PtAu/CoNC-3 sample reached 0.88 A·mg_(Pt)^(-1),which is 26.0 times higher than that of Pt/C.The results of first-principles calculation and CO stripping jointly demonstrate that the CO adsorption of PtAu/CoNC is considerably lower than that of Pt/CoNC and PtAu/C,which indicates that the synergistic effect of Pt,Au,and CoNC NFs is critical for the resistance of Pt to CO poisoning.This work is of great significance for a deeper understanding of the oxidation mechanism of formic acid and provides a feasible and promising strategy for enhancing the catalytic performance of the catalyst by improving the direct reaction pathway for FAO.展开更多
On-chip ultrafast mode-locking lasers are basic building blocks for the realization of a chip-based optical frequency comb.In this paper,an ultrafast saturable absorber made up of a graphene pad on top of a silicon wa...On-chip ultrafast mode-locking lasers are basic building blocks for the realization of a chip-based optical frequency comb.In this paper,an ultrafast saturable absorber made up of a graphene pad on top of a silicon waveguide is applied to implement an ultrafast pulse laser.Benefiting from the small mode area of the graphene/silicon hybrid waveguide,the saturable pulse energy is reduced by two orders of magnitude compared with the fiber.A mode-locked pulse with a duration of 542 fs and a repetition rate of 54.37 MHz is realized.Pump–probe measurement shows that the carrier relaxation process of free carrier recombination with atomic-thin graphene/silicon junctions is three orders of magnitude faster than silicon,which plays a fundamental role in pulse narrowing.The chip-scale silicon ultrafast laser lays a foundation for a new class of nonlinear devices,in which a combination with multiple functional silicon photonic circuits enables efficient nonlinear interaction at the micrometer scale and less than 1 W of power consumption.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant 62172255in part by the Outstanding Youth Program of Hubei Natural Science Foundation under Grant 2022CFA080the Wuhan AI Innovation Program(2022010702040056)。
文摘Edge caching has emerged as a promising application paradigm in 5G networks,and by building edge networks to cache content,it can alleviate the traffic load brought about by the rapid growth of Internet of Things(IoT)services and applications.Due to the limitations of Edge Servers(ESs)and a large number of user demands,how to make the decision and utilize the resources of ESs are significant.In this paper,we aim to minimize the total system energy consumption in a heterogeneous network and formulate the content caching optimization problem as a Mixed Integer Non-Linear Programming(MINLP).To address the optimization problem,a Deep Q-Network(DQN)-based method is proposed to improve the overall performance of the system and reduce the backhaul traffic load.In addition,the DQN-based method can effectively solve the limitation of traditional reinforcement learning(RL)in complex scenarios.Simulation results show that the proposed DQN-based method can greatly outperform other benchmark methods,and significantly improve the cache hit rate and reduce the total system energy consumption in different scenarios.
基金supported by the National Natural Science Foundation of China(grant no.U190420094).
文摘Gas explosions are one of the most lethal types of coal mine safety accidents.The powerful shock waves these explosions produce can cause damage to the lung tissue of nearby individuals,resulting in symptoms including pulmonary hemorrhage and pulmonary edema[1].At present,there is no effective treatment for gas explosion-induced lung injuries;therefore,there is an urgent need to identify new therapeutic means to improve the clinical management of the system of treatment for lung injury caused by gas explosions.Mesenchymal stem cells(MSCs)are adult stem cells with self-renewal ability and multilineage differentiation potential that exert their therapeutic potential through various mechanisms,including the regulation of inflammation and immune responses[2].Reports on the therapeutic role of MSCs in blast lung injury remain scarce.
基金supported by the Research Fund from Science and Technology Department of Sichuan Province (No. 2009FZ0065)Key Project of the Science and Technology Department of Sichuan Province (No. 2011SZ0101)+1 种基金Doctoral Fund of Ministry of Education of China (No. 20120181120002)supported by Open Fund of State Key Laboratory of Oral Diseases, Sichuan University
文摘Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass （BG） before, after, and during 35% hydrogen peroxide （HP） bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups： distilled deionized water （DDW）, BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order： group HP〉 BG before HP, BG after HP〉 BG during HP〉DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.
基金supported by the Major Program of National Agricultural Science and Technology of China (NK20220607)the National Natural Science Foundation of China (32272059 and31971883)the Science and Technology Department of Sichuan Province (2022ZDZX0014, 2021YFYZ0002, 2021YJ0297, and23NSFTD0045)。
文摘Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathogen races. In this study, a new resistance gene against Pst race CYR34 was identified and predicted using the descendants of a cross between AS1676, a highly resistant Chinese landrace, and Avocet S, a susceptible cultivar. From a heterozygous plant from a F7recombinant inbred line(RIL) population lacking the Yr18 gene, a near-isogenic line(NIL) population was developed to map the resistance gene. An allstage resistance gene, YrAS1676, was identified on chromosome arm 1AL via bulked-segregant exomecapture sequencing. By analyzing a large NIL population consisting of 6537 plants, the gene was further mapped to the marker interval between KA1A_485.36 and KA1A_490.13, spanning 485.36–490.13 Mb on1AL. A total of 66 annotated genes have been reported in this region. To characterize and predict the candidate gene(s), an RNA-seq was performed using NIL-R and NIL-S seedlings 3 days after CYR34 inoculation. Compared to NIL-S plants, NIL-R plants showed stronger immune reaction and higher expression levels of genes encoding pathogenesis-associated proteins. These differences may help to explain why NIL-R plants were more resistant to Pst race CYR34 than NIL-S plants. By combining fine-mapping and transcriptome sequencing, a calcium-dependent protein kinase gene was finally predicted as the potential candidate gene of YrAS1676. This gene contained a single-nucleotide polymorphism. The candidate gene was more highly expressed in NIL-R than in NIL-S plants. In field experiments with Pst challenge,the YrAS1676 genotype showed mitigation of disease damage and yield loss without adverse effects on tested agronomic traits. These results suggest that YrAS1676 has potential use in wheat stripe rust resistance breeding.
基金supported by the National Natural Science Foundation,Beijing,People’s Republic of China(81671058 and 81730031 to YW and 81401089 to MD)the National Research Foundation of Korea grants funded by the Republic of Korea(2019R1I1A1A01057744 to YK)the Foundation of Shanghai Municipal Science and Technology Commission(19ZR1407500 to FS)。
文摘In the current study,we sought to investigate whether T-type Ca^(2+)channels(TCCs)in the brain are involved in generating post-anesthetic hyperexcitatory behaviors(PAHBs).We found that younger rat pups(postnatal days 9-11)had a higher incidence of PAHBs and higher PAHB scores than older pups(postnatal days16-18)during emergence from sevoflurane anesthesia.The power spectrum of the theta oscillations(4 Hz-8 Hz)in the prefrontal cortex was significantly enhanced in younger pups when PAHBs occurred,while there were no significant changes in older pups.Both the power of theta oscillations and the level of PAHBs were significantly reduced by the administration of TCC inhibitors.Moreover,the sensitivity of TCCs in the medial dorsal thalamic nucleus to sevoflurane was found to increase with age by investigating the kinetic properties of TCCs in vitro.TCCs were activated by potentiated GABAergic depolarization with a sub-anesthetic dose of sevoflurane(1%).These data suggest that(1)TCCs in the brain contribute to the generation of PAHBs and the concomitant electroencephalographic changes;(2)the stronger inhibitory effect of sevoflurane contributes to the lack of PAHBs in older rats;and(3)the contribution of TCCs to PAHBs is not mediated by a direct effect of sevoflurane on TCCs.
基金supported in part by NIH/NIDCR K08DE018695, K12-EY016333/ K08-EY021520 (HCT), and R01DE022816
文摘Multiple growth factors（e.g., BMP2, TGF-b1, FGF2） and isolated genes have been shown to improve osteoblastic proliferation and mineralization, advancing bone tissue engineering. Among these factors, both polydopamine（PDA） and dopamine（DA） monomer have recently been reported to increase osteoblast proliferation and mineralization in vitro. Although a well-characterized neurotransmitter, DA＇s role in the bone is unknown. We hypothesize that DA can directly act on osteoblasts, and examined whether osteoblasts express DA receptors that respond to exogenous DA. m RNAs and protein cell lysates were obtained from MC3T3-E1 cells during osteogenic differentiation phase. Reverse transcription polymerase chain reaction and western blot analysis were used to examine the expression of DA receptors, D1–D5. Dose-response effect and time course of DA treatment on cell proliferation, mineralization, and osteogenic differentiation were investigated at pre-determined days. Real-time PCR was performed to investigate whether DA affects osteogenic gene expression（ALP, BSP, OC, OSX, RUNX2, and Collagen1a2） with or without receptor antagonists（SCH233390 and GR103691）. Two-way ANOVA was used for statistical analysis. All five DA receptors（D1, D2, D3, D4, and D5） m RNAs and proteins were expressed in MC3T3-E1 cells. DA treatment increased cell proliferation for up to 7 days（P, 0.05）. Osteogenic mineralization was significantly greater in the DA-treated group than control group（P, 0.05）. Finally, expression of all the osteogenic genes was inhibited by DA receptor antagonists for D1, D3, and D5. Our findings suggest that MC3T3-E1 osteoblasts express functional DA receptors that enhance proliferation and mineralization. PDA is not biologically inert and has important implications in orthopedic applications. Furthermore, osteoblast differentiation might be regulated by the nervous system, presumably during bone development, remodeling, or repair.
基金supported by grants from the National Key Research and Development Program of China(2022YFF1001900)the Hainan Province Science and Technology Special Fund(No.ZDYF2022XDNY144)+2 种基金the Hainan Provincial Academician Innovation Platform Project(No.HDYSZX-202004)the Hainan University Startup Fund(No.KYQD(ZR)21025)the Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture,Hainan University(No.XTCX2022NYB06)。
文摘Plants have evolved a sophisticated chemical defense network to counteract pathogens,with phenolamides and salicylic acid(SA)playing pivotal roles in the immune response.However,the synergistic regulatory mechanisms of their biosynthesis remain to be explored.Here,we identified a biosynthetic gene cluster on chromosome 2(BGC2)associated with the biosynthesis of phenolamide and SA,wherein the key component SlEPS1 exhibits dual catalytic functions for the synthesis of phenolamides and SA.Overexpression of the key component SlEPS1 of BGC2 in tomato enhanced resistance to the bacterial pathogen Pst DC3000,whereas knockout plants were more susceptible.Exogenous applications of SA and phenolamides revealed that these two compounds act synergistically to enhance plant resistance.Notably,during tomato domestication,a disease-resistant allele of SlEPS1,SlEPS1HapB,was subject to negative selection,leading to a reduction in phenolamide and SA levels and compromised disease resistance in modern varieties.Moreover,the SlMYB78 directly regulates the BGC2 gene cluster to enhance phenolamide and SA biosynthesis,modulating resistance to Pst DC3000.Our study employed multi-omics approaches to describe the synergistic regulation of phenolamide and SA biosynthesis,offering new insights into the complexity of plant immune-related metabolism.
基金supported by grants from the National Key Research and Development Program of China(2022YFF1001900)the Hainan Province Science and Technology Special Fund(no.ZDYF2022XDNY144)+4 种基金the Hainan Provincial Academician Innovation Platform Project(no.HD-YSZX-202004)the Young Elite Scientists Sponsorship Program by CAST(no.2019QNRC001)the Hainan University Startup Fund(no.KYQD(ZR)21025)the Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture,Hainan University(no.XTCX2022NYB06)the Innovation Project of Postgraduates of Hainan Province(no.Qhyb2022-56).
文摘Among plant metabolites,phenolamides,which are conjugates of hydroxycinnamic acid derivatives and polyamines,play important roles in plant adaptation to abiotic and biotic stresses.However,the molecular mechanisms underlying phenolamide metabolism and regulation as well as the effects of domestication and breeding on phenolamide diversity in tomato remain largely unclear.In this study,we performed a metabolite-based genome-wide association study and identified two biosynthetic gene clusters(BGC7 and BGC11)containing 12 genes involved in phenolamide metabolism,including four biosynthesis genes(two 4CL genes,one C3H gene,and one CPA gene),seven decoration genes(five AT genes and two UGT genes),and one transport protein gene(DTX29).Using gene co-expression network analysis we further discovered that SlMYB13 positively regulates the expression of two gene clusters,thereby promoting phenolamide accumulation.Genetic and physiological analyses showed that BGC7,BGC11 and SlMYB13 enhance drought tolerance by enhancing scavenging of reactive oxygen species and increasing abscisic acid content in tomato.Natural variation analysis suggested that BGC7,BGC11 and SlMYB13 were negatively selected during tomato domestication and improvement,leading to reduced phenolamide content and drought tolerance of cultivated tomato.Collectively,our study discovers a key mechanism of phenolamide biosynthesis and regulation in tomato and reveals that crop domestication and improvement shapes metabolic diversity to affect plant environmental adaptation.
文摘This manuscript focuses on bone repair/regeneration using tissue engineering strategies, and highlights nanobiotechnology developments leading to novel nanocomposite systems. About 6.5 million fractures occur annually in USA, and about 550,000 of these individual cases required the application of a bone graft. Autogenous and allogenous bone have been most widely used for bone graft based therapies; however, there are significant problems such as donor shortage and risk of infection. Alternatives using synthetic and natural biomaterials have been developed, and some are commercially available for clinical applications requiring bone grafts. However, it remains a great challenge to design an ideal synthetic graft that very closely mimics the bone tissue structurally, and can modulate the desired function in osteoblast and progenitor cell populations. Nanobiomaterials, specifically nanocomposites composed of hydroxyapatite （HA） and/or collagen are extremely promising graft substitutes. The biocomposites can be fabricated to mimic the material composition of native bone tissue, and additionally, when using nano-HA （reduced grain size）, one mimics the structural arrangement of native bone. A good understanding of bone biology and structure is critical to development of bone mimicking graft substitutes. HA and collagen exhibit excellent osteoconductive properties which can further modulate the regenerative/ healing process following fracture injury. Combining with other polymeric biomaterials will reinforce the mechanical properties thus making the novel nano-HA based composites comparable to human bone. We report on recent studies using nanocomposites that have been fabricated as particles and nanofibers for regeneration of segmental bone defects. The research in nanocomposites, highlight a pivotal role in the future development of an ideal orthopaedic implant device, however further significant advancements are necessary to achieve clinical use.
基金National Natural Science Foundation of China(61775075)State Key Laboratory of Advanced Optical Communication Systems and Networks,Shanghai Jiao Tong University,China(2019GZKF03005)。
文摘Graphene resting on a silicon-on-insulator platform offers great potential for optoelectronic devices.In the paper,we demonstrate all-optical modulation on the graphene-silicon hybrid waveguides(GSHWs)with tens of micrometers in length.Owing to strong interaction between graphene and silicon strip waveguides with compact light confinement,the modulation depth reaches 22.7%with a saturation threshold down to 1.38 pJ per pulse and a 30-μm-long graphene pad.A response time of 1.65 ps is verified by a pump-probe measurement with an energy consumption of 2.1 pJ.The complementary metal-oxide semiconductor compatible GSHWs with the strip configuration exhibit great potential for ultrafast and broadband all-optical modulation,indicating that employing two-dimensional materials has become a complementary technology to promote the silicon photonic platform.
基金NIH R03AR068108,NIH R01AR071649 and Purdue Start-up Package is greatly appreciated.The authors acknowledge the use of Purdue Life Science Microscopy Facility,Purdue Histology Core Facility.The authors also acknowledge the use of facilities of the Bindley Bioscience Center,a core facility of the NIH-funded Indiana Clinical and Translational Sciences Institute.
文摘Volumetric muscle loss(VML)injuries characterized by critical loss of skeletal muscle tissues result in severe functional impairment.Current treatments involving use of muscle grafts are limited by tissue availability and donor site morbidity.In this study,we designed and synthesized an implantable glycosaminoglycan-based hydrogel system consisting of thiolated hyaluronic acid(HA)and thiolated chondroitin sulfate(CS)cross-linked with poly(ethylene glycol)diacrylate to promote skeletal muscle regeneration of VML injuries in mice.The HA-CS hydrogels were optimized with suitable biophysical properties by fine-tuning degree of thiol group substitution to support C2C12 myoblast proliferation,myogenic differentiation and expression of myogenic markers MyoD,MyoG and MYH8.Furthermore,in vivo studies using a murine quadriceps VML model demonstrated that the HA-CS hydrogels supported integration of implants with the surrounding host tissue and facilitated migration of Pax7+satellite cells,de novo myofiber formation,angiogenesis,and innervation with minimized scar tissue formation during 4-week implantation.The hydrogel-treated and autograft-treated mice showed similar functional improvements in treadmill performance as early as 1-week post-implantation compared to the untreated groups.Taken together,our results demonstrate the promise of HA-CS hydrogels as regenerative engineering matrices to accelerate healing of skeletal muscle injuries.
基金the Teaching and Research Core Facility at the College of Life Sciences,NWAFU for support in this worksupported by grants from the National Natural Science Foundation of China(31770205 and 31970186 to X.L.,31870268 to F.Y.)。
文摘Plant interphase cortical microtubules(cMTs)mediate anisotropic cell expansion in response to environmental and developmental cues.In Arabidopsis thaliana,KATANIN 1(KTN1),the p60 catalytic subunit of the conserved MT-severing enzyme katanin,is essential for cMT ordering and anisotropic cell expansion.However,the regulation of KTN1-mediated cMT severing and ordering remains unclear.In this work,we report that the Arabidopsis IQ67 DOMAIN(IQD)family gene ABNORMAL SHOOT 6(ABS6)encodes a MT-associated protein.Overexpression of ABS6 leads to elongated cotyledons,directional pavement cell expansion,and highly ordered transverse cMT arrays.Genetic suppressor analysis revealed that ABS6-mediated cMT ordering is dependent on KTN1 and SHADE AVOIDANCE 4(SAV4).Live imaging of cMT dynamics showed that both ABS6 and SAV4 function as positive regulators of cMT severing.Furthermore,ABS6 directly interacts with KTN1 and SAV4 and promotes their recruitment to the cMTs.Finally,analysis of loss-of-function mutant combinations showed that ABS6,SAV4,and KTN1 work together to ensure the robust ethylene response in the apical hook of dark-grown seedlings.Together,our findings establish ABS6 and SAV4 as positive regulators of cMT severing and ordering,and highlight the role of cMT dynamics in fine-tuning differential growth in plants.
基金support from the National Natural Science Foundation of China(Nos.51801188,12034002,and 51971025)the China Postdoctoral Science Foundation(No.2018M632792)+3 种基金program for the Innovation Team of Science and Technology in University of Henan(No.20IRTSTHN014)Excellent Youth Foundation of Henan Scientific Committee(No.202300410356)the CAS Interdisciplinary Innovation Team(No.JCTD-2019-01)Beijing Natural Science Foundation(No.2204085)。
文摘Formic acid oxidation(FAO)is a typical anode reaction in fuel cells that can be facilitated by modulating its direct and indirect reaction pathways.Herein,PtAu bimetallic nanoparticles loaded onto Co and N co-doping carbon nanoframes(CoNC NFs)were designed to improve the selectivity of the direct reaction pathway for efficient FAO.Based on these subtle nanomaterials,the influences of elemental composition and carbon-support materials on the two pathways of FAO were investigated in detail.The results of fuel cell tests verified that the appropriate amount of Au in PtAu/CoNC can promote a direct reaction pathway for FAO,which is crucial for enhancing the oxidation efficiency of formic acid.In particular,the obtained PtAu/CoNC with an optimal Pt/Au atomic ratio of 1:1(PtAu/CoNC-3)manifests the best catalytic performance among the analogous obtained Pt-based electrocatalysts.The FAO mass activity of the PtAu/CoNC-3 sample reached 0.88 A·mg_(Pt)^(-1),which is 26.0 times higher than that of Pt/C.The results of first-principles calculation and CO stripping jointly demonstrate that the CO adsorption of PtAu/CoNC is considerably lower than that of Pt/CoNC and PtAu/C,which indicates that the synergistic effect of Pt,Au,and CoNC NFs is critical for the resistance of Pt to CO poisoning.This work is of great significance for a deeper understanding of the oxidation mechanism of formic acid and provides a feasible and promising strategy for enhancing the catalytic performance of the catalyst by improving the direct reaction pathway for FAO.
基金National Natural Science Foundation of China(61775075).
文摘On-chip ultrafast mode-locking lasers are basic building blocks for the realization of a chip-based optical frequency comb.In this paper,an ultrafast saturable absorber made up of a graphene pad on top of a silicon waveguide is applied to implement an ultrafast pulse laser.Benefiting from the small mode area of the graphene/silicon hybrid waveguide,the saturable pulse energy is reduced by two orders of magnitude compared with the fiber.A mode-locked pulse with a duration of 542 fs and a repetition rate of 54.37 MHz is realized.Pump–probe measurement shows that the carrier relaxation process of free carrier recombination with atomic-thin graphene/silicon junctions is three orders of magnitude faster than silicon,which plays a fundamental role in pulse narrowing.The chip-scale silicon ultrafast laser lays a foundation for a new class of nonlinear devices,in which a combination with multiple functional silicon photonic circuits enables efficient nonlinear interaction at the micrometer scale and less than 1 W of power consumption.
