Mulberry is a fundamental component of the global sericulture industry,and its positive impact on our health and the environment cannot be overstated.However,the mulberry reference genomes reported previously remained...Mulberry is a fundamental component of the global sericulture industry,and its positive impact on our health and the environment cannot be overstated.However,the mulberry reference genomes reported previously remained unassembled or unplaced sequences.Here,we report the assembly and analysis of the telomere-to-telomere gap-free reference genome of the mulberry species,Morus notabilis,which has emerged as an important reference in mulberry gene function research and genetic improvement.The mulberry gap-free reference genome produced here provides an unprecedented opportunity for us to study the structure and function of centromeres.Our results revealed that all mulberry centromeric regions share conserved centromeric satellite repeats with different copies.Strikingly,we found that M.notabilis is a species with polycentric chromosomes and the only reported polycentric chromosome species up to now.We propose a compelling model that explains the formation mechanism of new centromeres and addresses the unsolved scientific question of the chromosome fusion-fission cycle in mulberry species.Our study sheds light on the functional genomics,chromosome evolution,and genetic improvement of mulberry species.展开更多
A full-length cDNA of dehydrin BcDh2 from Boea crassifolia and its antisense nucleotidesequence have been transferred into tobacco (Nicotiana tabacum) NC89 under the controlof a caulifower mosaic virus 35S promoter. U...A full-length cDNA of dehydrin BcDh2 from Boea crassifolia and its antisense nucleotidesequence have been transferred into tobacco (Nicotiana tabacum) NC89 under the controlof a caulifower mosaic virus 35S promoter. Under a progressive water stress, photosyntheticrate, transpiration rate and stomatal conductance of the sense and antisense plantsreduced, and those of the control reduced much more. Photosynthetic rate, transpirationrate and stomatal conductance of all plants tested increased significantly 24 hourslater after recoveried water supply, and those of the sense and antisense plants werehigher than control. These indicated that overexpression of a dehydrin gene in tobaccomay improve tolerance to water stress for plants, however, antisense BcDh2 gene intransgenic plant did not influence physiological conditions. The results of germinationexperiment of the transgenic seeds showed that on MS medium with different concentrationPEG (8000), sense seed could more endure drought than control, while antisense seed wassensitive to drought. The results suggested that the overexpression of a dehydrin genein tobacco might improve the tolerance to water stress for plants.展开更多
For real-time classification of rock-masses in hard-rock tunnels,quick determination of the rock lithology on the tunnel face during construction is essential.Motivated by current breakthroughs in artificial intellige...For real-time classification of rock-masses in hard-rock tunnels,quick determination of the rock lithology on the tunnel face during construction is essential.Motivated by current breakthroughs in artificial intelligence technology in machine vision,a new automatic detection approach for classifying tunnel lithology based on tunnel face images was developed.The method benefits from residual learning for training a deep convolutional neural network(DCNN),and a multi-scale dilated convolutional attention block is proposed.The block with different dilation rates can provide various receptive fields,and thus it can extract multi-scale features.Moreover,the attention mechanism is utilized to select the salient features adaptively and further improve the performance of the model.In this study,an initial image data set made up of photographs of tunnel faces consisting of basalt,granite,siltstone,and tuff was first collected.After classifying and enhancing the training,validation,and testing data sets,a new image data set was generated.A comparison of the experimental findings demonstrated that the suggested approach outperforms previous classifiers in terms of various indicators,including accuracy,precision,recall,F1-score,and computing time.Finally,a visualization analysis was performed to explain the process of the network in the classification of tunnel lithology through feature extraction.Overall,this study demonstrates the potential of using artificial intelligence methods for in situ rock lithology classification utilizing geological images of the tunnel face.展开更多
Background： Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2（TLR2） is important for host recognition of invad...Background： Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2（TLR2） is important for host recognition of invading Grampositive microbes. Over-expression of TLR2 in transgenic dairy goats is a useful model for studying various aspects of infection with Gram-positive bacteria, in vivo.Methods： We over-expressed TLR2 in transgenic dairy goats. Pam3CSK4, a component of Gram-positive bacteria,triggered the TLR2 signal pathway by stimulating the monocytes-macrophages from the TLR2-positive transgenic goats, and induced over-expression of activator protein-1（AP-1）, phosphatidylinositol 3-kinase（PI3K） and transcription factor nuclear factor kappa B（NF-κB） and inflammation factors downstream of the signal pathway.Results： Compared with wild-type controls, measurements of various oxidative stress-related molecules showed that TLR2, when over-expressed in transgenic goat monocytes-macrophages, resulted in weak lipid damage, high level expression of anti-oxidative stress proteins, and significantly increased m RNA levels of transcription factor NF-E2-related factor-2（Nrf2） and the downstream gene, heme oxygenase-1（HO-1）. When Pam3CSK4 was used to stimulate ear tissue in vivo the HO-1 protein of the transgenic goats had a relatively high expression level.Conclusions： The results indicate that the oxidative injury in goats over-expressing TLR2 was reduced following Pam3CSK4 stimulation. The underlying mechanism for this reduction was increased expression of the anti-oxidation gene HO-1 by activation of the Nrf2 signal pathway.展开更多
For most triboelectric nanogenerators（TENGs）,the electric output should be a short AC pulse,which has the common characteristic of high voltage but low current.Thus it is necessary to convert the AC to DC and store ...For most triboelectric nanogenerators（TENGs）,the electric output should be a short AC pulse,which has the common characteristic of high voltage but low current.Thus it is necessary to convert the AC to DC and store the electric energy before driving conventional electronics.The traditional AC voltage regulator circuit which commonly consists of transformer,rectifier bridge,filter capacitor,and voltage regulator diode is not suitable for the TENG because the transformer＇s consumption of power is appreciable if the TENG output is small.This article describes an innovative design of an interface circuit for a triboelectric nanogenerator that is transformerless and easily integrated.The circuit consists of large-capacity electrolytic capacitors that can realize to intermittently charge lithium-ion batteries and the control section contains the charging chip,the rectifying circuit,a comparator chip and switch chip.More important,the whole interface circuit is completely self-powered and self-controlled.Meanwhile,the chip is widely used in the circuit,so it is convenient to integrate into PCB.In short,this work presents a novel interface circuit for TENGs and makes progress to the practical application and industrialization of nanogenerators.展开更多
The production of sewage sludge in China has been increasing sharply in order to treat 40% of the municipal sewage in 2005 as planned by central government. The main sludge disposal method is landfill owing to heavy m...The production of sewage sludge in China has been increasing sharply in order to treat 40% of the municipal sewage in 2005 as planned by central government. The main sludge disposal method is landfill owing to heavy metal contamination, but it presents an attractive potential for agricultural land application. Experiments were carried out to study the simultaneous metal removal and sludge stabilization by plants. The sludge samples were collected from Datansha Wastewater Treatment Plant of Guangzhou, it contained excessive Cu and Zn compared with the Chinese National Standard for Agricultural Use of Sewage Sludge. Plants growing on sludge beds were investigated to follow their growth and metal uptake. 30 sludge plants were identified during 1 year's observation. A Zn high accumulating and high growth rate plant (Alocasia macrorrhiza) was selected and grown on sludge beds in plots. The water, organic matter, heavy metals and nutrients contents, the E. coli number and the cress seed germination index were monitored for the sludge samples collected monthly. The plant growth parameters and its heavy metals contents were also determined. The sewage sludge treated by plants could be stabilized at about 5 months, the E. coli number was significantly decreased and the cress seed germination index attained 100%. Crop on sludge could ameliorate the sludge drying. The experiments are continuing to find out the appropriate plant combination for simultaneous sludge stabilization and metal removal for an acceptable period. Comparisons between the proposed processes and other methods for treating produced sludge such as composting, chemical and bacterial leaching were discussed.展开更多
基金This project was supported by the National Natural Science Foundation of China(32101544)the Chongqing Research Program of Basic Research and Frontier Technology(cstc2021yszxjcyj0004).
文摘Mulberry is a fundamental component of the global sericulture industry,and its positive impact on our health and the environment cannot be overstated.However,the mulberry reference genomes reported previously remained unassembled or unplaced sequences.Here,we report the assembly and analysis of the telomere-to-telomere gap-free reference genome of the mulberry species,Morus notabilis,which has emerged as an important reference in mulberry gene function research and genetic improvement.The mulberry gap-free reference genome produced here provides an unprecedented opportunity for us to study the structure and function of centromeres.Our results revealed that all mulberry centromeric regions share conserved centromeric satellite repeats with different copies.Strikingly,we found that M.notabilis is a species with polycentric chromosomes and the only reported polycentric chromosome species up to now.We propose a compelling model that explains the formation mechanism of new centromeres and addresses the unsolved scientific question of the chromosome fusion-fission cycle in mulberry species.Our study sheds light on the functional genomics,chromosome evolution,and genetic improvement of mulberry species.
基金supported by the National High Technology Research and Development Program of China(2001AA212161,2002AA224011)the National Natural Science Foundation of China(30170747).
文摘A full-length cDNA of dehydrin BcDh2 from Boea crassifolia and its antisense nucleotidesequence have been transferred into tobacco (Nicotiana tabacum) NC89 under the controlof a caulifower mosaic virus 35S promoter. Under a progressive water stress, photosyntheticrate, transpiration rate and stomatal conductance of the sense and antisense plantsreduced, and those of the control reduced much more. Photosynthetic rate, transpirationrate and stomatal conductance of all plants tested increased significantly 24 hourslater after recoveried water supply, and those of the sense and antisense plants werehigher than control. These indicated that overexpression of a dehydrin gene in tobaccomay improve tolerance to water stress for plants, however, antisense BcDh2 gene intransgenic plant did not influence physiological conditions. The results of germinationexperiment of the transgenic seeds showed that on MS medium with different concentrationPEG (8000), sense seed could more endure drought than control, while antisense seed wassensitive to drought. The results suggested that the overexpression of a dehydrin genein tobacco might improve the tolerance to water stress for plants.
基金funded by the National Natural Science Foundation of China(Grant No.51978460)the Open Fund of State Key Laboratory of Shield Machine and Boring Technology(No.SKLST-2019-K08).
文摘For real-time classification of rock-masses in hard-rock tunnels,quick determination of the rock lithology on the tunnel face during construction is essential.Motivated by current breakthroughs in artificial intelligence technology in machine vision,a new automatic detection approach for classifying tunnel lithology based on tunnel face images was developed.The method benefits from residual learning for training a deep convolutional neural network(DCNN),and a multi-scale dilated convolutional attention block is proposed.The block with different dilation rates can provide various receptive fields,and thus it can extract multi-scale features.Moreover,the attention mechanism is utilized to select the salient features adaptively and further improve the performance of the model.In this study,an initial image data set made up of photographs of tunnel faces consisting of basalt,granite,siltstone,and tuff was first collected.After classifying and enhancing the training,validation,and testing data sets,a new image data set was generated.A comparison of the experimental findings demonstrated that the suggested approach outperforms previous classifiers in terms of various indicators,including accuracy,precision,recall,F1-score,and computing time.Finally,a visualization analysis was performed to explain the process of the network in the classification of tunnel lithology through feature extraction.Overall,this study demonstrates the potential of using artificial intelligence methods for in situ rock lithology classification utilizing geological images of the tunnel face.
基金supported by grants from National Transgenic Creature Breeding Grand Project(2014ZX08008-005)Chinese Universities Scientific Fund(2014BH032)Natural Science Foundation of China(31501953, 31471352, 31471400 and 31171380)
文摘Background： Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2（TLR2） is important for host recognition of invading Grampositive microbes. Over-expression of TLR2 in transgenic dairy goats is a useful model for studying various aspects of infection with Gram-positive bacteria, in vivo.Methods： We over-expressed TLR2 in transgenic dairy goats. Pam3CSK4, a component of Gram-positive bacteria,triggered the TLR2 signal pathway by stimulating the monocytes-macrophages from the TLR2-positive transgenic goats, and induced over-expression of activator protein-1（AP-1）, phosphatidylinositol 3-kinase（PI3K） and transcription factor nuclear factor kappa B（NF-κB） and inflammation factors downstream of the signal pathway.Results： Compared with wild-type controls, measurements of various oxidative stress-related molecules showed that TLR2, when over-expressed in transgenic goat monocytes-macrophages, resulted in weak lipid damage, high level expression of anti-oxidative stress proteins, and significantly increased m RNA levels of transcription factor NF-E2-related factor-2（Nrf2） and the downstream gene, heme oxygenase-1（HO-1）. When Pam3CSK4 was used to stimulate ear tissue in vivo the HO-1 protein of the transgenic goats had a relatively high expression level.Conclusions： The results indicate that the oxidative injury in goats over-expressing TLR2 was reduced following Pam3CSK4 stimulation. The underlying mechanism for this reduction was increased expression of the anti-oxidation gene HO-1 by activation of the Nrf2 signal pathway.
基金supported by the National Natural Science Foundation of China(No.61434001)the 'Thousands Talents' Program for Pioneer Researchers and Its Innovation Team,China
文摘For most triboelectric nanogenerators（TENGs）,the electric output should be a short AC pulse,which has the common characteristic of high voltage but low current.Thus it is necessary to convert the AC to DC and store the electric energy before driving conventional electronics.The traditional AC voltage regulator circuit which commonly consists of transformer,rectifier bridge,filter capacitor,and voltage regulator diode is not suitable for the TENG because the transformer＇s consumption of power is appreciable if the TENG output is small.This article describes an innovative design of an interface circuit for a triboelectric nanogenerator that is transformerless and easily integrated.The circuit consists of large-capacity electrolytic capacitors that can realize to intermittently charge lithium-ion batteries and the control section contains the charging chip,the rectifying circuit,a comparator chip and switch chip.More important,the whole interface circuit is completely self-powered and self-controlled.Meanwhile,the chip is widely used in the circuit,so it is convenient to integrate into PCB.In short,this work presents a novel interface circuit for TENGs and makes progress to the practical application and industrialization of nanogenerators.
文摘The production of sewage sludge in China has been increasing sharply in order to treat 40% of the municipal sewage in 2005 as planned by central government. The main sludge disposal method is landfill owing to heavy metal contamination, but it presents an attractive potential for agricultural land application. Experiments were carried out to study the simultaneous metal removal and sludge stabilization by plants. The sludge samples were collected from Datansha Wastewater Treatment Plant of Guangzhou, it contained excessive Cu and Zn compared with the Chinese National Standard for Agricultural Use of Sewage Sludge. Plants growing on sludge beds were investigated to follow their growth and metal uptake. 30 sludge plants were identified during 1 year's observation. A Zn high accumulating and high growth rate plant (Alocasia macrorrhiza) was selected and grown on sludge beds in plots. The water, organic matter, heavy metals and nutrients contents, the E. coli number and the cress seed germination index were monitored for the sludge samples collected monthly. The plant growth parameters and its heavy metals contents were also determined. The sewage sludge treated by plants could be stabilized at about 5 months, the E. coli number was significantly decreased and the cress seed germination index attained 100%. Crop on sludge could ameliorate the sludge drying. The experiments are continuing to find out the appropriate plant combination for simultaneous sludge stabilization and metal removal for an acceptable period. Comparisons between the proposed processes and other methods for treating produced sludge such as composting, chemical and bacterial leaching were discussed.
