The traditional Chinese medicine Buyang Huanwu Decoction has been shown to improve the neu- rological function of patients with stroke. However, the precise mechanisms underlying its effect remain poorly understood. I...The traditional Chinese medicine Buyang Huanwu Decoction has been shown to improve the neu- rological function of patients with stroke. However, the precise mechanisms underlying its effect remain poorly understood. In this study, we established a rat model of cerebral ischemia by middle cerebral artery occlusion and intragastrically administered 5 g/kg Buyang Huanwu Decoction, once per day, for 1, 7, 14 and 28 days after cerebral ischemia. Immunohistochemical staining revealed a number of cells positive for the neural stem cell marker nestin in the cerebral cortex, the subven- tricular zone and the ipsilateral hippocampal dentate gyrus in rat models of cerebral ischemia. Buyang Huanwu Decoction significantly increased the number of cells positive for 5-bromodeoxyuridine (BrdU), a cell proliferation-related marker, microtubule-associated protein-2, a marker of neuronal differentiation, and growth-associated protein 43, a marker of synaptic plasticity in the ischemic rat cerebral regions. The number of positive cells peaked at 14 and 28 days after intragastric administration of Buyang Huanwu Decoction. These findings suggest that Buyang Huanwu Decoction can promote the proliferation and differentiation of neural stem cells and en- hance synaptic plasticity in ischemic rat brain tissue.展开更多
In Northeast China, permafrost advanced and retreated several times under the influences of fluctuating paleo-climatesand paleo-environments since the Late Pleistocene. During the last 60 years, many new data were obt...In Northeast China, permafrost advanced and retreated several times under the influences of fluctuating paleo-climatesand paleo-environments since the Late Pleistocene. During the last 60 years, many new data were obtained and studies wereconducted on the evolution of permafrost in Northeast China, but so far no systematic summary and review have been made.Based on sedimentary sequences, remains of past permafrost, paleo-flora and -fauna records, and dating data, permafrostevolution since the Late Pleistocene has been analyzed and reconstructed in this paper. Paleo-temperatures reconstructedfrom the remains of past permafrost and those from paleo-flora and -fauna are compared, and thus the southern limitof permafrost (SLP) in each climate period is inferred by the relationship of the permafrost distribution and the meanannual air/ground temperatures (MAAT/MAGT). Thus, the evolutionary history of permafrost is here divided into fivestages: (1) the Late Pleistocene (Last Glaciation, or LG) (65 to 10–8.5 ka), the Last Glaciation Maximum (LGM, 21–13 ka)in particular, the coldest period in the latest history with a cooling of about 6~10 °C, characterized by extensive occurrencesof glaciation, flourishing Mammathas-Coelodonta Faunal Complex (MCFC), widespread aeolian deposits, and significantsea level lowering, and permafrost greatly expanded southwards almost to the coastal plains (37°N–41°N); (2) the HoloceneMegathermal Period (HMP, 8.5–7.0 to 4.0–3.0 ka), 3~5 °C warmer than today, permafrost retreated to about 52°N; (3) theLate Holocene Cold Period (Neoglaciation) (4.0–3.0 to 1.0–0.5 ka), a cooling of 1~3 °C, some earlier thawed permafrost wasrefrozen or attached, and the SLP invaded southwards to 46°N; (4) the Little Ice Age (LIA, 500 to 100–150 a), the latestcold period with significant permafrost expansion; and (5) climate warming since the last century, during which NortheastChina has undergone extensive permafrost degradation. The frequent and substantial expansions and retreats of permafrosthave greatly impacted cold-region environments in Northeast China. North of the SLP during the HMP, or in the presentcontinuous permafrost zone, the existing permafrost was largely formed during the LG and was later overlapped by thepermafrost formed in the Neoglaciation. To the south, it was formed in the Neoglaciation. However, many aspects ofpermafrost evolution still await further investigations, such as data integration, numerical reconstruction, and merging ofChinese permafrost history with those of bordering regions as well as collaboration with related disciplines. Of these, studies on the evolution and degradation of permafrost during the past 150 years and its hydrological, ecological, and environmentalimpacts should be prioritized.展开更多
The constitutive promoter of cauliflower mosaic virus 35S (CaMV 35S) is a polar unidirectional promoter and is widely used in plant genetic engineering. In the present study, the unidirectional CaMV 35S promoter has...The constitutive promoter of cauliflower mosaic virus 35S (CaMV 35S) is a polar unidirectional promoter and is widely used in plant genetic engineering. In the present study, the unidirectional CaMV 35S promoter has been modified to a bi-directional promoter by fusing its minimal promoter element to the 5' end of CaMV 35S promoter in the opposite orientation. To qualitatively and quantitatively estimate its bi-directional transcriptional function and activity, two visible reporter genes, gusA (13-glucuronidase, GUS) and gfp (green fluorescent protein, GFP), were fused to the two ends of the promoter in bi-orientations ending with NOS terminator sequences, respectively. Stable expression of gusA and gfp genes in transgenic tobacco (Nicotiana tabacum L.) was visulized by histochemically staining for GUS and fluorescence microscopic observation under UV for GFP in transgenic plants. The expression of two reporter genes showed that the constructed bi-directional promoter did have the bi-directional transcriptional function in both expected orientations. The quantitative estimation of GUS and GFP were determined on a HITACHI F1000 Fluorescence Spectrophotometer with various wavelengths of excitation and emission. The GUS activity varied from g to 250 pmol 4-MU/min/mg protein and the GFP content varied from 0.9 to 1.8 μg/ mg protein in various lines of transgenic tobacco plants. Higher GUS activity generally coupled with lower GFP content, and vice versa.展开更多
As an important component of tokamaks,the divertor is mainly responsible for extracting heat and helium ash,and the targets of the divertor need to withstand high heat flux of 10 MW m-2 for steady-state operation.In t...As an important component of tokamaks,the divertor is mainly responsible for extracting heat and helium ash,and the targets of the divertor need to withstand high heat flux of 10 MW m-2 for steady-state operation.In this study,we proposed a new strategy,using microchannel cooling technology to remove high heat load on the targets of the divertor.The results demonstrated that the microchannel-based W/Cu flat-type mock-up successfully withstood the thermal fatigue test of 1000 cycles at 10 MW m^(-2)with cooling water of 26 l min^(-1),30°C(inlet),0.8 MPa(inlet),15 s power on and 15 s dwell time;the maximum temperature on the heat-loaded surface(W surface)of the mock-up was 493°C,which is much lower than the recrystallization temperature of W(1200°C).Moreover,no occurrence of macrocrack and‘hot spot’at the W surface,as well as no detachment of W/Cu tiles were observed during the thermal fatigue testing.These results indicate that microchannel cooling technology is an efflcient method for removing the heat load of the divertor at a low flow rate.The present study offers a promising solution to replace the monoblock design for the EAST divertor.展开更多
Behavioral decision-making at urban intersections is one of the primary difficulties currently impeding the development of intelligent vehicle technology.The problem is that existing decision-making algorithms cannot ...Behavioral decision-making at urban intersections is one of the primary difficulties currently impeding the development of intelligent vehicle technology.The problem is that existing decision-making algorithms cannot effectively deal with complex random scenarios at urban intersections.To deal with this,a deep deterministic policy gradient(DDPG)decision-making algorithm(T-DDPG)based on a time-series Markov decision process(T-MDP)was developed,where the state was extended to collect observations from several consecutive frames.Experiments found that T-DDPG performed better in terms of convergence and generalizability in complex intersection scenarios than a traditional DDPG algorithm.Furthermore,model-agnostic meta-learning(MAML)was incorporated into the T-DDPG algorithm to improve the training method,leading to a decision algorithm(T-MAML-DDPG)based on a secondary gradient.Simulation experiments of intersection scenarios were carried out on the Gym-Carla platform to verify and compare the decision models.The results showed that T-MAML-DDPG was able to easily deal with the random states of complex intersection scenarios,which could improve traffic safety and efficiency.The above decision-making models based on meta-reinforcement learning are significant for enhancing the decision-making ability of intelligent vehicles at urban intersections.展开更多
In this study,the resource distribution,morphological characteristics,artificial cultivation and market circulation of Paris Polyphylla var.yunnanensis and its polygerm varieties in Yunnan were investigated by referri...In this study,the resource distribution,morphological characteristics,artificial cultivation and market circulation of Paris Polyphylla var.yunnanensis and its polygerm varieties in Yunnan were investigated by referring to the research literature,field investigation and our planting experience.It is found that P.polyphylla var.yunnanensis is widely distributed in Yunnan Province,realizing large-scale artificial cultivation,while the wild resources of polygerm varieties are almost on the verge of extinction and are in urgent need of protection.展开更多
In order to respond to the national policy of energy saving and consumption reduction, the temperature drop formula of annular pipeline should be established to optimize the water mixing temperature and water mixing f...In order to respond to the national policy of energy saving and consumption reduction, the temperature drop formula of annular pipeline should be established to optimize the water mixing temperature and water mixing flow. The traditional temperature drop formula applies the high water cut actual situation to 13.7%. On the basis of the traditional Schulhof temperature drop formula, the influence of hydraulic friction on the oil flow temperature is calculated by the calculus idea. The heat transfer coefficient of the pipeline under the complex condition is obtained by the inverse algorithm, and the water mixing flow and water temperature are simulated with MATLAB. The function surface diagram of the degree and the back station temperature. The actual error can be reduced to 4.8%, and the return station temperature can be optimized by 7 degrees.展开更多
To the Editor:Allergic bronchopulmonary aspergillosis(ABPA)is an allergic lung disease caused by hypersensitivity to antigens from Aspergillus,and it most commonly occurs in patients with asthma or cysticbrosis.[1]The...To the Editor:Allergic bronchopulmonary aspergillosis(ABPA)is an allergic lung disease caused by hypersensitivity to antigens from Aspergillus,and it most commonly occurs in patients with asthma or cysticbrosis.[1]The main clinical characteristics of the disease are those related to elevated serum immunoglubulin(Ig)E level,positive Aspergillus fumigatus(A.fumigatus)specic IgE/IgG,repeated pulmonary inltration,and bronchiectasis.However,due to the lack of unied diagnostic criteria and screening methods,ABPA is always underdiagnosed.In 2021,new diagnostic criteria were proposed for allergic bronchopulmonary mycosis(ABPM)in the Japanese population.展开更多
Dear Editor,The process of anther development is generally conserved across plant species(Ma,2005).Many protein-coding genes and noncoding RNAs have been identified to participate in early anther development in Arabid...Dear Editor,The process of anther development is generally conserved across plant species(Ma,2005).Many protein-coding genes and noncoding RNAs have been identified to participate in early anther development in Arabidopsis(Walbot and Egger,2016).mi R319 is one of the most ancient and conserved mi RNA families in land plants(Chávez Montes et al.,2014).展开更多
Background:Since RNA sequencing has shown that induced pluripotent stem cells(iPSCs)share a common antigen profile with tumor cells,cancer vaccines that focus on iPSCs have made promising progress in recent years.Prev...Background:Since RNA sequencing has shown that induced pluripotent stem cells(iPSCs)share a common antigen profile with tumor cells,cancer vaccines that focus on iPSCs have made promising progress in recent years.Previously,we showed that iPSCs derived from leukemic cells of patients with primary T cell acute lymphoblastic leukemia(T-ALL)have a gene expression profile similar to that of T-ALL cell lines.Methods:Mice with T-ALL were treated with dendritic and T(DC-T)cells loaded with intact and complete antigens from T-ALL-derived iPSCs(T-ALL-iPSCs).We evaluated the safety and antitumor efficiency of autologous tumor-derived iPSC antigens by flow cytometry,cytokine release assay,acute toxicity experiments,long-term toxicity experiments,and other methods.Results:Our results indicate that complete tumor antigens from T-ALL-iPSCs could inhibit the growth of inoculated tumors in immunocompromised mice without causing acute and long-term toxicity.Conclusion:T-ALL-iPSC-based treatment is safe and can be used as a potential strategy for leukemia immunotherapy.展开更多
MicroRNAs(miRNAs)are short endogenous non-coding RNAs that regulate gene expression at the posttranscriptional level in a broad range of eukaryotic species.In animals,it is estimated that more than 60%of mammalian gen...MicroRNAs(miRNAs)are short endogenous non-coding RNAs that regulate gene expression at the posttranscriptional level in a broad range of eukaryotic species.In animals,it is estimated that more than 60%of mammalian genes are targets of miRNAs,with miRNAs regulating cellular processes such as differentiation and proliferation.In plants,miRNAs regulate gene expression and play essential roles in diverse biological processes,including growth,development,and stress responses.Arabidopsis mutants with defective miRNA biogenesis are embryo lethal,and abnormal expression of miRNAs can cause severe developmental phenotypes.It is therefore crucial that the homeostasis of miRNAs is tightly regulated.In this review,we summarize the key mechanisms of plant miRNA biogenesis and stabilization.We provide an update on nuclear proteins with functions in miRNA biogenesis and proteins linking miRNA biogenesis to environmental triggers.展开更多
microRNAs (miRNAs)are endogenous small non-coding RNAs that bind to mRNAs and target them for cleavage and/or translational repression,leading to gene silencing.We previously developed short tandem target mimic (STTM)...microRNAs (miRNAs)are endogenous small non-coding RNAs that bind to mRNAs and target them for cleavage and/or translational repression,leading to gene silencing.We previously developed short tandem target mimic (STTM)technology to deactivate endogenous miRNAs in Arabidopsis.Here,we created hundreds of STTMs that target both conserved and species-specific miRNAs in Arabidopsis,tomato,rice,and maize,providing a resource for the functional interrogation of miRNAs.We not only revealed the functions of several miRNAs in plant development,but also demonstrated that tissue-specific inactivation of a few miRNAs in rice leads to an increase in grain size without adversely affecting overall plant growth and development.RNA-seq and small RNAseq analyses of STTM156/157 and STTM165/166 transgenic plants revealed the roles of these miRNAs in plant hormone biosynthesis and activation,secondary metabolism,and ion-channel activity-associated electrophysiology,demonstrating that STTM technology is an effective approach for studying miRNA functions.To facilitate the study and application of STTM transgenic plants and to provide a useful platform for storing and sharing of information about miRNA-regulated gene networks,we have established an online Genome Browser (https://blossom.ffr.mtu.edu/designindex2.php) to display the transcriptomic and miRNAomic changes in STTMinduced miRNA knockdown plants.展开更多
Pressing need goes ahead for accessing freshwater in insufficient supply countries and regions,which will become a restrictive factor for human development and production.In recent years,solar-driven water evaporation...Pressing need goes ahead for accessing freshwater in insufficient supply countries and regions,which will become a restrictive factor for human development and production.In recent years,solar-driven water evaporation(SDWE)systems have attracted increasing attention for their specialty in no consume conventional energy,pollution-free,and the high purity of fresh water.In particular,carbon-based photothermal conversion materials are preferred light-absorbing material for SDWE systems because of their wide range of spectrum absorption and high photothermal conversion efficiency based on superconjugate effect.Until now,many carbon-based SDWE systems have been reported,and various structures emerged and were designed to enhance light absorption,optimize heat management,and improve the efficient water transport path.In this review,we attempt to give a comprehensive summary and discussions of structure progress of the carbon-based SDWE systems and their working mechanisms,including carbon nanoparticles systems,single-layer photothermal membrane systems,bi-layer structural photothermal systems,porous carbon-based materials systems,and three dimensional(3D)systems.In these systems,the latest 3D systems can expand the light path by allowing light to be reflected multiple times in the microcavity to increase the light absorption rate,and its large heat exchange area can prompt more water to evaporate,which makes them the promising application foreground.We hope our review can spark the probing of underlying principles and inspiring design strategies of these carbonbased SDWE systems,and further guide device optimizations,eventually promoting in extensive practical applications in the future.展开更多
Learning from nature has traditionally and continuously provided important insights to drive a paradigm shift in technology.In particular,recent studies show that many biological organisms exhibit spectacular surface ...Learning from nature has traditionally and continuously provided important insights to drive a paradigm shift in technology.In particular,recent studies show that many biological organisms exhibit spectacular surface topography such as shape,size,spatial organization,periodicity,interconnectivity,and hierarchy to endow them with the capability to adapt dynamically and responsively to a wide range of environments.More excitingly,in a broader perspective,these normally neglected topological features have the potential to fundamentally change the way of how engineering surface works,such as how fluid flows,how heat is transported,and how energy is generated,saved,and converted,to name a few.Thus,the design of nature-inspired surface topography for unique functions will spur new thinking and provide paradigm shift in the development of the new engineering surfaces.In this review,we first present a brief introduction to some insights extracted from nature.Then,we highlight recent progress in designing new surface topographies and demonstrate their applications in emerging areas including thermal-fluid transport,anti-icing,water harvesting,power generation,adhesive control,and soft robotics.Finally,we offer our perspectives on this emerging field,with the aim to stimulate new thinking on the development of next-generation of new materials and devices,and dramatically extend the boundaries of traditional engineering.展开更多
基金supported by grants from the National Nature Science Foundation of China,No.30873355,81072939,81273989,81202694the Foundation of Educational Commission of Hunan Province in China,No.11C0954
文摘The traditional Chinese medicine Buyang Huanwu Decoction has been shown to improve the neu- rological function of patients with stroke. However, the precise mechanisms underlying its effect remain poorly understood. In this study, we established a rat model of cerebral ischemia by middle cerebral artery occlusion and intragastrically administered 5 g/kg Buyang Huanwu Decoction, once per day, for 1, 7, 14 and 28 days after cerebral ischemia. Immunohistochemical staining revealed a number of cells positive for the neural stem cell marker nestin in the cerebral cortex, the subven- tricular zone and the ipsilateral hippocampal dentate gyrus in rat models of cerebral ischemia. Buyang Huanwu Decoction significantly increased the number of cells positive for 5-bromodeoxyuridine (BrdU), a cell proliferation-related marker, microtubule-associated protein-2, a marker of neuronal differentiation, and growth-associated protein 43, a marker of synaptic plasticity in the ischemic rat cerebral regions. The number of positive cells peaked at 14 and 28 days after intragastric administration of Buyang Huanwu Decoction. These findings suggest that Buyang Huanwu Decoction can promote the proliferation and differentiation of neural stem cells and en- hance synaptic plasticity in ischemic rat brain tissue.
基金supported by the Subproject No. XDA05120302 (Permafrost Extent in China during the Last Glaciation Maximum and Megathermal)Strategic Pilot Science and Technology Program of the Chinese Academy of Sciences (Identification of Carbon Budgets for Adaptation to Changing Climate and the Associated Issues) (Grant No. XDA05000000)the auspices of the International Permafrost Association (IPA) Action Group on "Last Permafrost Maximum and Minimum (LPMM) on the Eurasian Continent"
文摘In Northeast China, permafrost advanced and retreated several times under the influences of fluctuating paleo-climatesand paleo-environments since the Late Pleistocene. During the last 60 years, many new data were obtained and studies wereconducted on the evolution of permafrost in Northeast China, but so far no systematic summary and review have been made.Based on sedimentary sequences, remains of past permafrost, paleo-flora and -fauna records, and dating data, permafrostevolution since the Late Pleistocene has been analyzed and reconstructed in this paper. Paleo-temperatures reconstructedfrom the remains of past permafrost and those from paleo-flora and -fauna are compared, and thus the southern limitof permafrost (SLP) in each climate period is inferred by the relationship of the permafrost distribution and the meanannual air/ground temperatures (MAAT/MAGT). Thus, the evolutionary history of permafrost is here divided into fivestages: (1) the Late Pleistocene (Last Glaciation, or LG) (65 to 10–8.5 ka), the Last Glaciation Maximum (LGM, 21–13 ka)in particular, the coldest period in the latest history with a cooling of about 6~10 °C, characterized by extensive occurrencesof glaciation, flourishing Mammathas-Coelodonta Faunal Complex (MCFC), widespread aeolian deposits, and significantsea level lowering, and permafrost greatly expanded southwards almost to the coastal plains (37°N–41°N); (2) the HoloceneMegathermal Period (HMP, 8.5–7.0 to 4.0–3.0 ka), 3~5 °C warmer than today, permafrost retreated to about 52°N; (3) theLate Holocene Cold Period (Neoglaciation) (4.0–3.0 to 1.0–0.5 ka), a cooling of 1~3 °C, some earlier thawed permafrost wasrefrozen or attached, and the SLP invaded southwards to 46°N; (4) the Little Ice Age (LIA, 500 to 100–150 a), the latestcold period with significant permafrost expansion; and (5) climate warming since the last century, during which NortheastChina has undergone extensive permafrost degradation. The frequent and substantial expansions and retreats of permafrosthave greatly impacted cold-region environments in Northeast China. North of the SLP during the HMP, or in the presentcontinuous permafrost zone, the existing permafrost was largely formed during the LG and was later overlapped by thepermafrost formed in the Neoglaciation. To the south, it was formed in the Neoglaciation. However, many aspects ofpermafrost evolution still await further investigations, such as data integration, numerical reconstruction, and merging ofChinese permafrost history with those of bordering regions as well as collaboration with related disciplines. Of these, studies on the evolution and degradation of permafrost during the past 150 years and its hydrological, ecological, and environmentalimpacts should be prioritized.
文摘The constitutive promoter of cauliflower mosaic virus 35S (CaMV 35S) is a polar unidirectional promoter and is widely used in plant genetic engineering. In the present study, the unidirectional CaMV 35S promoter has been modified to a bi-directional promoter by fusing its minimal promoter element to the 5' end of CaMV 35S promoter in the opposite orientation. To qualitatively and quantitatively estimate its bi-directional transcriptional function and activity, two visible reporter genes, gusA (13-glucuronidase, GUS) and gfp (green fluorescent protein, GFP), were fused to the two ends of the promoter in bi-orientations ending with NOS terminator sequences, respectively. Stable expression of gusA and gfp genes in transgenic tobacco (Nicotiana tabacum L.) was visulized by histochemically staining for GUS and fluorescence microscopic observation under UV for GFP in transgenic plants. The expression of two reporter genes showed that the constructed bi-directional promoter did have the bi-directional transcriptional function in both expected orientations. The quantitative estimation of GUS and GFP were determined on a HITACHI F1000 Fluorescence Spectrophotometer with various wavelengths of excitation and emission. The GUS activity varied from g to 250 pmol 4-MU/min/mg protein and the GFP content varied from 0.9 to 1.8 μg/ mg protein in various lines of transgenic tobacco plants. Higher GUS activity generally coupled with lower GFP content, and vice versa.
基金financial support from the National MCF Energy R&D Program(No.2018YFE0312300)National Natural Science Foundation of China(No.51706100)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20180477)Fundamental Research Funds for the Central Universities(No.30918011205)。
文摘As an important component of tokamaks,the divertor is mainly responsible for extracting heat and helium ash,and the targets of the divertor need to withstand high heat flux of 10 MW m-2 for steady-state operation.In this study,we proposed a new strategy,using microchannel cooling technology to remove high heat load on the targets of the divertor.The results demonstrated that the microchannel-based W/Cu flat-type mock-up successfully withstood the thermal fatigue test of 1000 cycles at 10 MW m^(-2)with cooling water of 26 l min^(-1),30°C(inlet),0.8 MPa(inlet),15 s power on and 15 s dwell time;the maximum temperature on the heat-loaded surface(W surface)of the mock-up was 493°C,which is much lower than the recrystallization temperature of W(1200°C).Moreover,no occurrence of macrocrack and‘hot spot’at the W surface,as well as no detachment of W/Cu tiles were observed during the thermal fatigue testing.These results indicate that microchannel cooling technology is an efflcient method for removing the heat load of the divertor at a low flow rate.The present study offers a promising solution to replace the monoblock design for the EAST divertor.
基金supported in part by the Beijing Municipal Science and Technology Project(No.Z191100007419010)Automobile Industry Joint Fund(No.U1764261)of the National Natural Science Foundation of China+1 种基金Shandong Key R&D Program(No.2020CXGC010118)Key Laboratory for New Technology Application of Road Conveyance of Jiangsu Province(No.BM20082061706)。
文摘Behavioral decision-making at urban intersections is one of the primary difficulties currently impeding the development of intelligent vehicle technology.The problem is that existing decision-making algorithms cannot effectively deal with complex random scenarios at urban intersections.To deal with this,a deep deterministic policy gradient(DDPG)decision-making algorithm(T-DDPG)based on a time-series Markov decision process(T-MDP)was developed,where the state was extended to collect observations from several consecutive frames.Experiments found that T-DDPG performed better in terms of convergence and generalizability in complex intersection scenarios than a traditional DDPG algorithm.Furthermore,model-agnostic meta-learning(MAML)was incorporated into the T-DDPG algorithm to improve the training method,leading to a decision algorithm(T-MAML-DDPG)based on a secondary gradient.Simulation experiments of intersection scenarios were carried out on the Gym-Carla platform to verify and compare the decision models.The results showed that T-MAML-DDPG was able to easily deal with the random states of complex intersection scenarios,which could improve traffic safety and efficiency.The above decision-making models based on meta-reinforcement learning are significant for enhancing the decision-making ability of intelligent vehicles at urban intersections.
基金Sichuan Provincial Department of Science and Technology(2017SZYZF0004).
文摘In this study,the resource distribution,morphological characteristics,artificial cultivation and market circulation of Paris Polyphylla var.yunnanensis and its polygerm varieties in Yunnan were investigated by referring to the research literature,field investigation and our planting experience.It is found that P.polyphylla var.yunnanensis is widely distributed in Yunnan Province,realizing large-scale artificial cultivation,while the wild resources of polygerm varieties are almost on the verge of extinction and are in urgent need of protection.
文摘In order to respond to the national policy of energy saving and consumption reduction, the temperature drop formula of annular pipeline should be established to optimize the water mixing temperature and water mixing flow. The traditional temperature drop formula applies the high water cut actual situation to 13.7%. On the basis of the traditional Schulhof temperature drop formula, the influence of hydraulic friction on the oil flow temperature is calculated by the calculus idea. The heat transfer coefficient of the pipeline under the complex condition is obtained by the inverse algorithm, and the water mixing flow and water temperature are simulated with MATLAB. The function surface diagram of the degree and the back station temperature. The actual error can be reduced to 4.8%, and the return station temperature can be optimized by 7 degrees.
基金funded by the National Natural Science Foundation of China(Nos.82270033 and 81873407)the Natural Science Foundation of Hunan province(No.2022JJ30924)
文摘To the Editor:Allergic bronchopulmonary aspergillosis(ABPA)is an allergic lung disease caused by hypersensitivity to antigens from Aspergillus,and it most commonly occurs in patients with asthma or cysticbrosis.[1]The main clinical characteristics of the disease are those related to elevated serum immunoglubulin(Ig)E level,positive Aspergillus fumigatus(A.fumigatus)specic IgE/IgG,repeated pulmonary inltration,and bronchiectasis.However,due to the lack of unied diagnostic criteria and screening methods,ABPA is always underdiagnosed.In 2021,new diagnostic criteria were proposed for allergic bronchopulmonary mycosis(ABPM)in the Japanese population.
基金supported by the National Natural Science Foundation of China(32070614)the National Key Research and Development Program of China(2019YFA0903900)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2023A1515010441)Guangdong Innovation Team Project(2014ZT05S078)。
文摘Dear Editor,The process of anther development is generally conserved across plant species(Ma,2005).Many protein-coding genes and noncoding RNAs have been identified to participate in early anther development in Arabidopsis(Walbot and Egger,2016).mi R319 is one of the most ancient and conserved mi RNA families in land plants(Chávez Montes et al.,2014).
基金Science,Technology and Innovation Commission of Shenzhen Municipality,Grant/Award Number:CYJ20170412155231633Health Commission of Shenzhen Municipality,Grant/Award Number:SZXK062。
文摘Background:Since RNA sequencing has shown that induced pluripotent stem cells(iPSCs)share a common antigen profile with tumor cells,cancer vaccines that focus on iPSCs have made promising progress in recent years.Previously,we showed that iPSCs derived from leukemic cells of patients with primary T cell acute lymphoblastic leukemia(T-ALL)have a gene expression profile similar to that of T-ALL cell lines.Methods:Mice with T-ALL were treated with dendritic and T(DC-T)cells loaded with intact and complete antigens from T-ALL-derived iPSCs(T-ALL-iPSCs).We evaluated the safety and antitumor efficiency of autologous tumor-derived iPSC antigens by flow cytometry,cytokine release assay,acute toxicity experiments,long-term toxicity experiments,and other methods.Results:Our results indicate that complete tumor antigens from T-ALL-iPSCs could inhibit the growth of inoculated tumors in immunocompromised mice without causing acute and long-term toxicity.Conclusion:T-ALL-iPSC-based treatment is safe and can be used as a potential strategy for leukemia immunotherapy.
基金Research in the Chen laboratory on small RNAs and RNA modifications is supported by grants from National Institutes of Health(R01GM061146 and R01GM129373).
文摘MicroRNAs(miRNAs)are short endogenous non-coding RNAs that regulate gene expression at the posttranscriptional level in a broad range of eukaryotic species.In animals,it is estimated that more than 60%of mammalian genes are targets of miRNAs,with miRNAs regulating cellular processes such as differentiation and proliferation.In plants,miRNAs regulate gene expression and play essential roles in diverse biological processes,including growth,development,and stress responses.Arabidopsis mutants with defective miRNA biogenesis are embryo lethal,and abnormal expression of miRNAs can cause severe developmental phenotypes.It is therefore crucial that the homeostasis of miRNAs is tightly regulated.In this review,we summarize the key mechanisms of plant miRNA biogenesis and stabilization.We provide an update on nuclear proteins with functions in miRNA biogenesis and proteins linking miRNA biogenesis to environmental triggers.
基金the National Science Foundation,USA (IOS-1048216 and IOS-1340001)the National Natural Science Foundation of China (31571679,31501292,31871554)+1 种基金the Major Science and Technology Project of Henan Province (141100110600)the Support Plan of Science and Technology Innovation Team in Universities of Henan Province (171RTSTHN015),and the Key Scientific Research Project in Universities of Henan Province (16A210009).G.T.is also supported by the Guangdong Innovation Research Team Fund (2014ZT058078)and the 111 Project (D16014)to Henan University.S.T.was supported by a post-doctoral fellowship from Henan Agricultural University.F.M.was a visiting scholar supported by the China Scholarship Council (CSC).T.P.,Z.Z.,L.S.,and L.T.were visiting PhD students supported by scholarships from Henan Agricultural University.
文摘microRNAs (miRNAs)are endogenous small non-coding RNAs that bind to mRNAs and target them for cleavage and/or translational repression,leading to gene silencing.We previously developed short tandem target mimic (STTM)technology to deactivate endogenous miRNAs in Arabidopsis.Here,we created hundreds of STTMs that target both conserved and species-specific miRNAs in Arabidopsis,tomato,rice,and maize,providing a resource for the functional interrogation of miRNAs.We not only revealed the functions of several miRNAs in plant development,but also demonstrated that tissue-specific inactivation of a few miRNAs in rice leads to an increase in grain size without adversely affecting overall plant growth and development.RNA-seq and small RNAseq analyses of STTM156/157 and STTM165/166 transgenic plants revealed the roles of these miRNAs in plant hormone biosynthesis and activation,secondary metabolism,and ion-channel activity-associated electrophysiology,demonstrating that STTM technology is an effective approach for studying miRNA functions.To facilitate the study and application of STTM transgenic plants and to provide a useful platform for storing and sharing of information about miRNA-regulated gene networks,we have established an online Genome Browser (https://blossom.ffr.mtu.edu/designindex2.php) to display the transcriptomic and miRNAomic changes in STTMinduced miRNA knockdown plants.
基金the National Key R&D Program of China(2018YFA0209500)the National Natural Science Foundation of China(21621091 and 21975209)the Fundamental Research Funds for the Central Universities(20720190037)。
文摘Pressing need goes ahead for accessing freshwater in insufficient supply countries and regions,which will become a restrictive factor for human development and production.In recent years,solar-driven water evaporation(SDWE)systems have attracted increasing attention for their specialty in no consume conventional energy,pollution-free,and the high purity of fresh water.In particular,carbon-based photothermal conversion materials are preferred light-absorbing material for SDWE systems because of their wide range of spectrum absorption and high photothermal conversion efficiency based on superconjugate effect.Until now,many carbon-based SDWE systems have been reported,and various structures emerged and were designed to enhance light absorption,optimize heat management,and improve the efficient water transport path.In this review,we attempt to give a comprehensive summary and discussions of structure progress of the carbon-based SDWE systems and their working mechanisms,including carbon nanoparticles systems,single-layer photothermal membrane systems,bi-layer structural photothermal systems,porous carbon-based materials systems,and three dimensional(3D)systems.In these systems,the latest 3D systems can expand the light path by allowing light to be reflected multiple times in the microcavity to increase the light absorption rate,and its large heat exchange area can prompt more water to evaporate,which makes them the promising application foreground.We hope our review can spark the probing of underlying principles and inspiring design strategies of these carbonbased SDWE systems,and further guide device optimizations,eventually promoting in extensive practical applications in the future.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFA0209500)the Research Council of Hong Kong(Grant Nos.C1018-17G,and 11275216)+3 种基金the Shenzhen Science and Technology Innovation Council(Grant No.JCYJ20170413141208098)the National Natural Science Foundation of China(Grant No.51706100)the Natural Science Foundation of Jiangsu Province(Grant No.BK20180477)the City University of Hong Kong(Grant No.9360140)
文摘Learning from nature has traditionally and continuously provided important insights to drive a paradigm shift in technology.In particular,recent studies show that many biological organisms exhibit spectacular surface topography such as shape,size,spatial organization,periodicity,interconnectivity,and hierarchy to endow them with the capability to adapt dynamically and responsively to a wide range of environments.More excitingly,in a broader perspective,these normally neglected topological features have the potential to fundamentally change the way of how engineering surface works,such as how fluid flows,how heat is transported,and how energy is generated,saved,and converted,to name a few.Thus,the design of nature-inspired surface topography for unique functions will spur new thinking and provide paradigm shift in the development of the new engineering surfaces.In this review,we first present a brief introduction to some insights extracted from nature.Then,we highlight recent progress in designing new surface topographies and demonstrate their applications in emerging areas including thermal-fluid transport,anti-icing,water harvesting,power generation,adhesive control,and soft robotics.Finally,we offer our perspectives on this emerging field,with the aim to stimulate new thinking on the development of next-generation of new materials and devices,and dramatically extend the boundaries of traditional engineering.