In recent years,the global surge of High-speed Railway(HSR)revolutionized ground transportation,providing secure,comfortable,and punctual services.The next-gen HSR,fueled by emerging services like video surveillance,e...In recent years,the global surge of High-speed Railway(HSR)revolutionized ground transportation,providing secure,comfortable,and punctual services.The next-gen HSR,fueled by emerging services like video surveillance,emergency communication,and real-time scheduling,demands advanced capabilities in real-time perception,automated driving,and digitized services,which accelerate the integration and application of Artificial Intelligence(AI)in the HSR system.This paper first provides a brief overview of AI,covering its origin,evolution,and breakthrough applications.A comprehensive review is then given regarding the most advanced AI technologies and applications in three macro application domains of the HSR system:mechanical manufacturing and electrical control,communication and signal control,and transportation management.The literature is categorized and compared across nine application directions labeled as intelligent manufacturing of trains and key components,forecast of railroad maintenance,optimization of energy consumption in railroads and trains,communication security,communication dependability,channel modeling and estimation,passenger scheduling,traffic flow forecasting,high-speed railway smart platform.Finally,challenges associated with the application of AI are discussed,offering insights for future research directions.展开更多
This study investigates mental health literacy among young and middle-aged urban and rural residents and the differences in mental health literacy,perceived social support and subjective well-being.From January to Feb...This study investigates mental health literacy among young and middle-aged urban and rural residents and the differences in mental health literacy,perceived social support and subjective well-being.From January to February 2022,620 participants(320 rural and 300 urban residents)from three provinces of China were selected by con-venience sampling.A general data questionnaire,mental health literacy scale,perceived social support scale and subjective well-being scale were administered.The mental health literacy scores of urban residents were 3.34±0.57 and those of rural residents were 2.73±0.79.The results of multiple regression analysis showed that the mental health literacy scores of rural residents were more significant than those of urban residents in terms of sex and age,while urban residents’mental health literacy scores were more significant than those of rural resi-dents in terms of monthly income.Mental health literacy,perceived social support and subjective well-being of young and middle-aged urban and rural residents were all positively correlated(P<0.01).While the level of mental health literacy is better among urban residents than rural residents,perceived social support plays a partial mediating role between mental health literacy and subjective well-being of both urban and rural residents,and should be the focus of researchers seeking to improve the level of well-being of residents.展开更多
Nonpolar(1120)plane In_(x)Ga_(1-x)N epilayers comprising the entire In content(x)range were successfully grown on nanoscale Ga N islands by metal-organic chemical vapor deposition.The structural and optical properties...Nonpolar(1120)plane In_(x)Ga_(1-x)N epilayers comprising the entire In content(x)range were successfully grown on nanoscale Ga N islands by metal-organic chemical vapor deposition.The structural and optical properties were studied intensively.It was found that the surface morphology was gradually smoothed when x increased from 0.06 to 0.33,even though the crystalline quality was gradually declined,which was accompanied by the appearance of phase separation in the In_(x)Ga_(1-x)N layer.Photoluminescence wavelengths of 478 and 674 nm for blue and red light were achieved for x varied from 0.06 to 0.33.Furthermore,the corresponding average lifetime(τ_(1/e))of carriers for the nonpolar In Ga N film was decreased from 406 ps to 267 ps,indicating that a high-speed modulation bandwidth can be expected for nonpolar In Ga N-based light-emitting diodes.Moreover,the bowing coefficient(b)of the(1120)plane In Ga N was determined to be 1.91 e V for the bandgap energy as a function of x.展开更多
The tomato(Solanum lycopersicum)male sterile 32(ms32)mutant has been used in hybrid seed breeding programs largely because it produces no pollen and has exserted stigmas.In this study,histological examination of anthe...The tomato(Solanum lycopersicum)male sterile 32(ms32)mutant has been used in hybrid seed breeding programs largely because it produces no pollen and has exserted stigmas.In this study,histological examination of anthers revealed dysfunctional pollen and tapetum development in the ms32 mutant.The ms32 locus was fine mapped to a 28.5 kb interval that encoded four putative genes.Solyc01g081100,a homolog of Arabidopsis bHLH10/89/90 and rice EAT1,was proposed to be the candidate gene of MS32 because it contained a single nucleotide polymorphism(SNP)that led to the formation of a premature stop codon.A codominant derived cleaved amplified polymorphic sequence(dCAPS)marker,MS32D,was developed based on the SNP.Real-time quantitative reverse-transcription PCR showed that most of the genes,which were proposed to be involved in pollen and tapetum development in tomato,were downregulated in the ms32 mutant.These findings may aid in marker-assisted selection of ms32 in hybrid breeding programs and facilitate studies on the regulatory mechanisms of pollen and tapetum development in tomato.展开更多
Leaf veins play an important role in plant growth and development,and the bundle sheath(BS)is believed to greatly improve the photosynthetic efficiency of C_(4) plants.The OBV mutation in tomato(Solanum lycopersicum)r...Leaf veins play an important role in plant growth and development,and the bundle sheath(BS)is believed to greatly improve the photosynthetic efficiency of C_(4) plants.The OBV mutation in tomato(Solanum lycopersicum)results in dark veins and has been used widely in processing tomato varieties.However,physiological performance has difficulty explaining fitness in production.In this study,we confirmed that this mutation was caused by both the increased chlorophyll content and the absence of bundle sheath extension(BSE)in the veins.Using genome-wide association analysis and map-based cloning,we revealed that OBV encoded a C_(2)H_(2) L domain class transcription factor.It was localized in the nucleus and presented cell type-specific gene expression in the leaf veins.Furthermore,we verified the gene function by generating CRISPR/Cas9 knockout and overexpression mutants of the tomato gene.RNA sequencing analysis revealed that OBV was involved in regulating chloroplast development and photosynthesis,which greatly supported the change in chlorophyll content by mutation.Taken together,these findings demonstrated that OBV affected the growth and development of tomato by regulating chloroplast development in leaf veins.This study also provides a solid foundation to further decipher the mechanism of BSEs and to understand the evolution of photosynthesis in land plants.展开更多
Recently,we have shown that FOXP3,a critical transcription factor in regulatory T cells(Tregs),is expressed in pancreatic epithelial cells,and restrain the activity of CD8+T cells by upregulating PD-L1,which in turn r...Recently,we have shown that FOXP3,a critical transcription factor in regulatory T cells(Tregs),is expressed in pancreatic epithelial cells,and restrain the activity of CD8+T cells by upregulating PD-L1,which in turn regulates immune escape in pancreatic ductal adenocarcinoma(PDAC)^(1).On the basis of a series of studies of our laboratory,we hypothesize that a subset of pancreatic epithelial cells mimics the phenotype and function of Tregs(named quasi-Tregs or qTregs);this concept has been supported by a peer-reviewed commentary^(2).Moreover,evidence suggests that tumor epithelial cells can mimic other types of immune cells and participate in the formation of a tumor immunosuppressive microenvironment(TIM).展开更多
Bladder cancer (BC) is one of the most common malignant tumors in the urinary system.Due to the poor prognosis and high mortality rate of the disease,it is urgent to develop new drugs with high efficacy and low toxici...Bladder cancer (BC) is one of the most common malignant tumors in the urinary system.Due to the poor prognosis and high mortality rate of the disease,it is urgent to develop new drugs with high efficacy and low toxicity to treat BC.Echinatin (Ecn) is a bioactive natural flavonoid oflicorice that has attracted special attention for its promising anti-tumor potential.Herein,we explored the inhibitory effects of Echinatin on BC cells and probed the possible molecular mechanism.We found that Ecnin vitro inhibited the proliferation,migration,and invasion,arrested the cell cycle at the G2/M phase,and promoted apoptosis in BC cells.Besides,Ecn had no notable cytotoxicity towards human normal cells.We subsequently confirmed that Ecn restrained xenograft tumor growth and metastasis of BC cells in vivo .Mechanistically,Ecn activated the p38 signaling pathway but inactivated the Wnt/β-catenin signaling pathway,while over-expression of β-catenin and the p38 inhibitor both attenuated the inhibitory effects of Ecn on BC cells.Remarkably,Ecn combined with cisplatin (DDP) or gemcitabine (Gem) had synergistic inhibitory effects on BC cells.In summary,our results validate that Ecn inhibits the tumor growth of human BC cells via p38 and Wnt/β-catenin signaling pathways.More meaningfully,our results suggest a potential strategy to enhance DDP- or Gem-induced inhibitory effects on BC cells by combining with Ecn.展开更多
The long-term impact of fulvic acid(FA)on partial nitritation(PN)systemwas initially examined in this study.The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulatio...The long-term impact of fulvic acid(FA)on partial nitritation(PN)systemwas initially examined in this study.The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate(NAR nearly 100%)and ammonium removal rate(ARR 56.85%),while FA over 50 mg/L decreased ARR from 56.85%to 0.7%.Sludge characteristics analysis found that appropriate FA(<50 mg/L)exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi.The analysis of metagenomics suggested that the presence of limited FA(0-50 mg/L)stimulated the generation of NADH,which favors the denitrification and nitrite reduction.The negative impact of FA on the PN system could be divided into two stages.Initially,limited FA(50-120 mg/L)was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria(Thauera).Increasing heterotrophs competed with AOB(Nitrosomonas)for dissolved oxygen,causing AOB to be eliminated and ARR to declined.Subsequently,when FA dosage was over 120 mg/L,Anaerolineae were inhibited and heterotrophic bacteria reduced,resulting in the abundance of AOB recovered.Nevertheless,the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced,leading to the deterioration of reactor performance.Overall,these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.展开更多
van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic devices.Herein,a WS_(2)/InSe vdWH pho...van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic devices.Herein,a WS_(2)/InSe vdWH photodiode is proposed and fabricated by precisely stacking InSe and WS_(2)flakes through an all-dry transfer method.The WS_(2)/InSe vdWH forms an n–n heterojunction with strong built-in electric field due to their intrinsic n-type semiconductor characteristics and energy-band alignments with a large Fermi level offset between WS_(2)and InSe.As a result,the device displays excellent photovoltaic behavior with a large open voltage of 0.47 V and a short-circuit current of 11.7 nA under 520 nm light illumination.Significantly,a fast rising/decay time of 63/76μs,a large light on/off ratio of 105,a responsivity of 61 mA/W,a high detectivity of 2.5×10^(11) Jones,and a broadband photoresponse ranging from ultraviolet to near-infrared(325–980 nm)are achieved at zero bias.This study provides a strategy for developing high-performance self-powered broadband photodetectors based on 2D materials.展开更多
Metal-organic frameworks are recognized as promising multifunctional materials,especially metal-organic framework-based photocatalysts,which are considered to be ideal photocatalytic materials.Herein,a new type of UiO...Metal-organic frameworks are recognized as promising multifunctional materials,especially metal-organic framework-based photocatalysts,which are considered to be ideal photocatalytic materials.Herein,a new type of UiO-66/MoSe_(2) composite was prepared using the solvothermal method.The optimum composite was selected by adjusting the mass ratio of UiO-66 and MoSe_(2).X-ray diffraction analysis showed that the mass ratio influenced the crystal plane exposure rate of the composite,which may have affected its photocatalytic performance.The composite is composed of ultra-thin flower-like MoSe_(2) that wrapped around cubic UiO-66,a structure that increases the abundance of active sites for reactions and is more conducive to the separation of carriers.The photocatalytic properties of the composite were evaluated by measuring the degradation rate of Rhodamine B and the catalyst’s ability to reduce Cr(VI)-containing wastewater under visible light irradiation.Rhodamine B was decolorized completely in 120 min,and most of the Cr(VI)was reduced within 150 min.The photochemical mechanism of the complex was studied in detail.The existence of Mo^(6+)and oxygen vacancies,in addition to the Z-type heterojunction promote the separation of electrons and holes,which enhances the photocatalytic effect.展开更多
There are significant differences in the extent of impurity incorporation on different crystallographic directions of GaN microstructures,and the impurity-related deep energy level behavior will have a significant imp...There are significant differences in the extent of impurity incorporation on different crystallographic directions of GaN microstructures,and the impurity-related deep energy level behavior will have a significant impact on device performance.However,a comprehensive understanding of the effect of lateral growth on device performance has not been achieved due to the lack of comprehensive spatial distribution characterization of the optical behavior and impurity incorporation in GaN microstructures.We present a comprehensive study of the optical behavior and growth mechanism of self-assembled GaN microdisks using nanoscale spatially resolved cathodoluminescence(CL)mapping.We have found a clear growth orientation-dependent optical behavior of the lateral and vertical growth sectors of self-assembled GaN microcrystals.The lateral growth sector,i.e.,the{101¯1}-growth sector,forms six side facets of the microdisk and shows significant near-bandgap emission(NBE)and weak deep energy level luminescence.Cavity effect enhanced emission was found for the first time in such a truncated hexagonal Na-flux GaN microdisk system with an ultra-smooth surface(Ra<0.7 nm)and low stress.The self-assembled microdisk shows significant ultraviolet(UV)lasing action(main lasing peak wavelength 370.9 nm,quality factor 1278,threshold 6×10^(4)μJ/cm^(2))under pulsed optical pumping.We believe that the appearance of UV lasing action may be related to the light limitation on the six side facets of the lateral growth of the GaN microdisk,the high structural quality,the low content of deep energy level defects,the low surface roughness,and the low stress.展开更多
In Xinjiang,in the process of whole stalk harvesting of cotton stalks,there is a problem that the cotton stalks are easily pulled off,and there is an urgent need to develop flexible stalk-pulling machines.Through lite...In Xinjiang,in the process of whole stalk harvesting of cotton stalks,there is a problem that the cotton stalks are easily pulled off,and there is an urgent need to develop flexible stalk-pulling machines.Through literature,patent summary,and field research,it is found that domestic researchers have designed many kinds of machines for the problem of easy breaking of cotton stalks,but there is no flexible cotton stalk-pulling machine for the time being.In this study,two flexible cotton stalk-pulling machines were intended to address the problem of easy breakage of cotton stalks.On the basis of the first-generation machine,the design of the second-generation machine was improved.In order to further improve the operational performance of the flexible cotton stalks pulling tools,the operational mechanism of the core working parts of the tools was analyzed and a comparative test was done in a large field.Analysis and the comparative tests proved that improving the clamping working stroke s of the stalk-pulling components can effectively reduce the cotton stalks leakage rate.By using a flexible clamping process,a part of the deformation of cotton stalks can be transferred to the flexible material.To a certain extent,the deformation length L of the contact surface between the cotton stalk and the stalk pulling part is reduced,and the deformation displacementΔy is correspondingly lower.The toughness of the cotton stalk is not significantly decreased and the cotton stalk does not break easily.The improved second-generation machine has a 3.67% to 3.79% lower cotton stalks leakage rate and a 5.65% to 6.30% lower cotton stalks breakage rate than the first-generation machine.As the land in Xinjiang is clay soil,soil bonding to cotton stalks pulling force F2 is larger,resulting in cotton stalks being more difficult to be pulled out of the machine at once.The test proved that the improved second-generation implements had a significant improvement in the cotton stalk-pulling effect because of the subsequent pulling interval CD.The test results verify the analysis results and the research results can provide a theoretical basis for the subsequent structural improvement and performance enhancement of the flexible cotton stalk-pulling machine,which is of reference significance for solving the problem that the cotton stalks are easily pulled and broken in Xinjiang,China.展开更多
Late blight is the most devastating potato disease and it also causes serious yield loss in tomato.Several disease resistance genes (R genes) to late blight have been cloned from potato in the past decade.However,the ...Late blight is the most devastating potato disease and it also causes serious yield loss in tomato.Several disease resistance genes (R genes) to late blight have been cloned from potato in the past decade.However,the resistance mechanisms remain elusive.Tomato and potato belong to the botanical family Solanaceace and share remarkably conserved genome structure.Since tomato is a model system in genetic and plant pathology research,we used tomato to develop a powerful mutant screening system that will greatly facilitate the analysis of the signaling pathway of resistance to Phytophthora infestans.First we proved that the R3a transgenic tomatoes developed specific hypersensitive cell death response (HR) to P.infestans strains carrying the corresponding avirulence gene Avr3a,indicating that the signaling pathway from the R3a-Avr3a recognition to HR is conserved between potato and tomato.Second,we generated transgenic tomatoes carrying both R3a and Avr3a genes,with the latter under the control of a glucocorticiod-inducible promoter.Dexamethasone induced expression of Avr3a and resulted in localized HR.This versatile system can be used to construct a mutant library to screen surviving mutants whose resistance signal transduction was interrupted,providing the basis to identify key genes involved in the resistance to late blight in Solanaceae.展开更多
The leaf area index(LAI)is an important agroecological physiological parameter affecting vegetation growth.To apply the genetic algorithms neural network model(GANNM)to the remote sensing inversion of winter wheat LAI...The leaf area index(LAI)is an important agroecological physiological parameter affecting vegetation growth.To apply the genetic algorithms neural network model(GANNM)to the remote sensing inversion of winter wheat LAI throughout the growth cycle and based on GaoFen-3 Synthetic aperture radar(GF-3 SAR)images and GaoFen-1 Wide Field of View(GF-1 WFV)images,the Xiangfu District in the east of Kaifeng City,Henan Province,was selected as the testing region.Winter wheat LAI data from five growth stages were combined,and optical and microwave polarization decomposition vegetation index models were used.The backscattering coefficient was extracted by modified water cloud model(MWCM),and the LAI was obtained by MWCM inversion as input factors to construct GANNM to invert LAI.The root mean square error(RMSE)and determination coefficient(R2)were used as evaluation indicators of the model.The fitting accuracy of winter wheat LAI in five growth stages by GANNM inversion was better than that of the BP neural network model;the R2 was higher than 0.8,and RMSE was lower than 0.3,indicating that the model could accurately invert the growth status of winter wheat in five growth stages.展开更多
Background: The transcription factor Homeobox C8 (HOXC8) is overexpressed and regulates many important genes involved in the proliferation and invasion of many malignant tumors. However, the function of HOXC8 in gliom...Background: The transcription factor Homeobox C8 (HOXC8) is overexpressed and regulates many important genes involved in the proliferation and invasion of many malignant tumors. However, the function of HOXC8 in gliomas remains unclear. Method: Based on the Chinese Glioma Genome Atlas (CGGA) set, HOXC8 expression is negatively correlated with overall survival (OS). Small interfering RNA (si-HOXC8) was used to downregulate the mRNA and protein expression levels of HOXC8 to assess glioma cell proliferation, migration and invasion. Results: Patients with higher HOXC8 levels showed poorer prognosis. DAVID analysis results indicated that HOXC8 was related to cell cycle, cell adhesion and immune response. In U251 and LN229 glioma cells treated with small interfering RNA for HOXC8 (si-HOXC8) for gene knockdown, significantly lower cell capacity of growth, migration and invasion was observed. Moreover, HOXC8 knockdown could reduce the protein expression of classical epithelial mesenchymal transition (EMT) related markers. Conclusion: HOXC8 may play an important role in glioma proliferation, migration and invasion. These findings indicated that HOXC8 may constitute a novel target for glioma treatment.展开更多
Surface-enhanced Raman spectroscopy(SERS)has been successfully applied to detect various biomolecules,but it is still in challenge to assay living cells or bacteria sensitively,selectively and quantitatively in comple...Surface-enhanced Raman spectroscopy(SERS)has been successfully applied to detect various biomolecules,but it is still in challenge to assay living cells or bacteria sensitively,selectively and quantitatively in complex environments.In this paper,4-ATP and DTNB are assembled on Ag nanoparticle(NP)-decorated poly(styrene-co-acrylic acid)(PSA)nanospheres and then sealed by silica shells to form sensitive SERS labels based on the localized surface plasmon resonance of Ag NPs and large light scattering cross-sections of PSA nanospheres.They are further developed as encoding tags for dual detection of S.aureus and E.coli after assembling corresponding aptamers,which demonstrate ultralow detection limits of 8 cell L-1 for S.aureus and 2 cell L-1 for E.coli.Such a bioassay indicates a point-of-care strategy of ultrasensitively biomedical detections by encoding specific SERS tags.展开更多
Super-pixel algorithms based on convolutional neural networks with fuzzy C-means clustering are widely used for high-spatial-resolution remote sensing images segmentation.However,this model requires the number of clus...Super-pixel algorithms based on convolutional neural networks with fuzzy C-means clustering are widely used for high-spatial-resolution remote sensing images segmentation.However,this model requires the number of clusters to be set manually,resulting in a low automation degree due to the complexity of the iterative clustering process.To address this problem,a segmentation method based on a self-learning super-pixel network(SLSP-Net)and modified automatic fuzzy clustering(MAFC)is proposed.SLSP-Net performs feature extraction,non-iterative clustering,and gradient reconstruction.A lightweight feature embedder is adopted for feature extraction,thus expanding the receiving range and generating multi-scale features.Automatic matching is used for non-iterative clustering,and the overfitting of the network model is overcome by adaptively adjusting the gradient weight parameters,providing a better irregular super-pixel neighborhood structure.An optimized density peak algorithm is adopted for MAFC.Based on the obtained super-pixel image,this maximizes the robust decision-making interval,which enhances the automation of regional clustering.Finally,prior entropy fuzzy C-means clustering is applied to optimize the robust decision-making and obtain the final segmentation result.Experimental results show that the proposed model offers reduced experimental complexity and achieves good performance,realizing not only automatic image segmentation,but also good segmentation results.展开更多
基金supported by the National Natural Science Foundation of China(62172033).
文摘In recent years,the global surge of High-speed Railway(HSR)revolutionized ground transportation,providing secure,comfortable,and punctual services.The next-gen HSR,fueled by emerging services like video surveillance,emergency communication,and real-time scheduling,demands advanced capabilities in real-time perception,automated driving,and digitized services,which accelerate the integration and application of Artificial Intelligence(AI)in the HSR system.This paper first provides a brief overview of AI,covering its origin,evolution,and breakthrough applications.A comprehensive review is then given regarding the most advanced AI technologies and applications in three macro application domains of the HSR system:mechanical manufacturing and electrical control,communication and signal control,and transportation management.The literature is categorized and compared across nine application directions labeled as intelligent manufacturing of trains and key components,forecast of railroad maintenance,optimization of energy consumption in railroads and trains,communication security,communication dependability,channel modeling and estimation,passenger scheduling,traffic flow forecasting,high-speed railway smart platform.Finally,challenges associated with the application of AI are discussed,offering insights for future research directions.
基金supported by the Philosophy and Social Science Planning Project of Henan Province(2020BSH015).
文摘This study investigates mental health literacy among young and middle-aged urban and rural residents and the differences in mental health literacy,perceived social support and subjective well-being.From January to February 2022,620 participants(320 rural and 300 urban residents)from three provinces of China were selected by con-venience sampling.A general data questionnaire,mental health literacy scale,perceived social support scale and subjective well-being scale were administered.The mental health literacy scores of urban residents were 3.34±0.57 and those of rural residents were 2.73±0.79.The results of multiple regression analysis showed that the mental health literacy scores of rural residents were more significant than those of urban residents in terms of sex and age,while urban residents’mental health literacy scores were more significant than those of rural resi-dents in terms of monthly income.Mental health literacy,perceived social support and subjective well-being of young and middle-aged urban and rural residents were all positively correlated(P<0.01).While the level of mental health literacy is better among urban residents than rural residents,perceived social support plays a partial mediating role between mental health literacy and subjective well-being of both urban and rural residents,and should be the focus of researchers seeking to improve the level of well-being of residents.
基金supported by the National Natural Science Foundation of China(Grant Nos.62074077,61921005,61974062,and 61904082)the China Postdoctoral Science Foundation(Grant No.2020M671441)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant Nos.19KJB510006 and 19KJB510039)the Natural Science Foundation of Jiangsu Province(Grant No.BK20190765)。
文摘Nonpolar(1120)plane In_(x)Ga_(1-x)N epilayers comprising the entire In content(x)range were successfully grown on nanoscale Ga N islands by metal-organic chemical vapor deposition.The structural and optical properties were studied intensively.It was found that the surface morphology was gradually smoothed when x increased from 0.06 to 0.33,even though the crystalline quality was gradually declined,which was accompanied by the appearance of phase separation in the In_(x)Ga_(1-x)N layer.Photoluminescence wavelengths of 478 and 674 nm for blue and red light were achieved for x varied from 0.06 to 0.33.Furthermore,the corresponding average lifetime(τ_(1/e))of carriers for the nonpolar In Ga N film was decreased from 406 ps to 267 ps,indicating that a high-speed modulation bandwidth can be expected for nonpolar In Ga N-based light-emitting diodes.Moreover,the bowing coefficient(b)of the(1120)plane In Ga N was determined to be 1.91 e V for the bandgap energy as a function of x.
基金supported by the National Natural Science Foundation of China(No.31471889)the National Key Research and Development Program of China(No.2016YFD0101703)+1 种基金the Central Publicinterest Scientific Institution Basal Research Fund(No.Y2017PT52)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(No.CAAS-ASTIP-IVFCAAS).
文摘The tomato(Solanum lycopersicum)male sterile 32(ms32)mutant has been used in hybrid seed breeding programs largely because it produces no pollen and has exserted stigmas.In this study,histological examination of anthers revealed dysfunctional pollen and tapetum development in the ms32 mutant.The ms32 locus was fine mapped to a 28.5 kb interval that encoded four putative genes.Solyc01g081100,a homolog of Arabidopsis bHLH10/89/90 and rice EAT1,was proposed to be the candidate gene of MS32 because it contained a single nucleotide polymorphism(SNP)that led to the formation of a premature stop codon.A codominant derived cleaved amplified polymorphic sequence(dCAPS)marker,MS32D,was developed based on the SNP.Real-time quantitative reverse-transcription PCR showed that most of the genes,which were proposed to be involved in pollen and tapetum development in tomato,were downregulated in the ms32 mutant.These findings may aid in marker-assisted selection of ms32 in hybrid breeding programs and facilitate studies on the regulatory mechanisms of pollen and tapetum development in tomato.
基金This research was supported by The National Key Research and Development Program of China(Grant No.2019YFD1000301)the Fundamental Research Funds for Central Nonprofit Scientific Institution(Grant No.IVF-BRF2018006)+1 种基金the Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,Ministry of Agriculture,Chinathe Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(Grant No.CAAS-ASTIP-IVFCAAS).
文摘Leaf veins play an important role in plant growth and development,and the bundle sheath(BS)is believed to greatly improve the photosynthetic efficiency of C_(4) plants.The OBV mutation in tomato(Solanum lycopersicum)results in dark veins and has been used widely in processing tomato varieties.However,physiological performance has difficulty explaining fitness in production.In this study,we confirmed that this mutation was caused by both the increased chlorophyll content and the absence of bundle sheath extension(BSE)in the veins.Using genome-wide association analysis and map-based cloning,we revealed that OBV encoded a C_(2)H_(2) L domain class transcription factor.It was localized in the nucleus and presented cell type-specific gene expression in the leaf veins.Furthermore,we verified the gene function by generating CRISPR/Cas9 knockout and overexpression mutants of the tomato gene.RNA sequencing analysis revealed that OBV was involved in regulating chloroplast development and photosynthesis,which greatly supported the change in chlorophyll content by mutation.Taken together,these findings demonstrated that OBV affected the growth and development of tomato by regulating chloroplast development in leaf veins.This study also provides a solid foundation to further decipher the mechanism of BSEs and to understand the evolution of photosynthesis in land plants.
基金This work was funded by the National Natural Science Foundation of China(Grant No.81772633)the Taishan Researchers Program of Shandong Province,and the Major State Basic Research Development Program of Natural Science Foundation of Shandong Province in China(Grant No.ZR2020ZD11).
文摘Recently,we have shown that FOXP3,a critical transcription factor in regulatory T cells(Tregs),is expressed in pancreatic epithelial cells,and restrain the activity of CD8+T cells by upregulating PD-L1,which in turn regulates immune escape in pancreatic ductal adenocarcinoma(PDAC)^(1).On the basis of a series of studies of our laboratory,we hypothesize that a subset of pancreatic epithelial cells mimics the phenotype and function of Tregs(named quasi-Tregs or qTregs);this concept has been supported by a peer-reviewed commentary^(2).Moreover,evidence suggests that tumor epithelial cells can mimic other types of immune cells and participate in the formation of a tumor immunosuppressive microenvironment(TIM).
基金supported by the National Natural Science Foundation of China(No.81874001)the Program for Youth Innovation in Future Medicine of Chongqing Medical University(China)(No.W0086).
文摘Bladder cancer (BC) is one of the most common malignant tumors in the urinary system.Due to the poor prognosis and high mortality rate of the disease,it is urgent to develop new drugs with high efficacy and low toxicity to treat BC.Echinatin (Ecn) is a bioactive natural flavonoid oflicorice that has attracted special attention for its promising anti-tumor potential.Herein,we explored the inhibitory effects of Echinatin on BC cells and probed the possible molecular mechanism.We found that Ecnin vitro inhibited the proliferation,migration,and invasion,arrested the cell cycle at the G2/M phase,and promoted apoptosis in BC cells.Besides,Ecn had no notable cytotoxicity towards human normal cells.We subsequently confirmed that Ecn restrained xenograft tumor growth and metastasis of BC cells in vivo .Mechanistically,Ecn activated the p38 signaling pathway but inactivated the Wnt/β-catenin signaling pathway,while over-expression of β-catenin and the p38 inhibitor both attenuated the inhibitory effects of Ecn on BC cells.Remarkably,Ecn combined with cisplatin (DDP) or gemcitabine (Gem) had synergistic inhibitory effects on BC cells.In summary,our results validate that Ecn inhibits the tumor growth of human BC cells via p38 and Wnt/β-catenin signaling pathways.More meaningfully,our results suggest a potential strategy to enhance DDP- or Gem-induced inhibitory effects on BC cells by combining with Ecn.
基金supported by the Key Research&Developmental Program of Shandong Province(Nos.2021CXGC011202,2020CXGC011404)the Beijing Natural Science Foundation(No.8192004)the Beijing Major Science and Technology Projects(No.Z181100005318001)
文摘The long-term impact of fulvic acid(FA)on partial nitritation(PN)systemwas initially examined in this study.The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate(NAR nearly 100%)and ammonium removal rate(ARR 56.85%),while FA over 50 mg/L decreased ARR from 56.85%to 0.7%.Sludge characteristics analysis found that appropriate FA(<50 mg/L)exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi.The analysis of metagenomics suggested that the presence of limited FA(0-50 mg/L)stimulated the generation of NADH,which favors the denitrification and nitrite reduction.The negative impact of FA on the PN system could be divided into two stages.Initially,limited FA(50-120 mg/L)was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria(Thauera).Increasing heterotrophs competed with AOB(Nitrosomonas)for dissolved oxygen,causing AOB to be eliminated and ARR to declined.Subsequently,when FA dosage was over 120 mg/L,Anaerolineae were inhibited and heterotrophic bacteria reduced,resulting in the abundance of AOB recovered.Nevertheless,the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced,leading to the deterioration of reactor performance.Overall,these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.
基金the National Natural Science Foundation of China(Nos.11734005,61821002,62075041,12004069,and 62204157)the National Key Research and Development Program of China(Nos.2018YFA0209101 and 2017YFA0700500)the Fundamental Research Funds for the Central Universities(No.2242021k10009).
文摘van der Waals heterostructures(vdWHs)based on two-dimensional(2D)materials without the crystal lattice matching constraint have great potential for high-performance optoelectronic devices.Herein,a WS_(2)/InSe vdWH photodiode is proposed and fabricated by precisely stacking InSe and WS_(2)flakes through an all-dry transfer method.The WS_(2)/InSe vdWH forms an n–n heterojunction with strong built-in electric field due to their intrinsic n-type semiconductor characteristics and energy-band alignments with a large Fermi level offset between WS_(2)and InSe.As a result,the device displays excellent photovoltaic behavior with a large open voltage of 0.47 V and a short-circuit current of 11.7 nA under 520 nm light illumination.Significantly,a fast rising/decay time of 63/76μs,a large light on/off ratio of 105,a responsivity of 61 mA/W,a high detectivity of 2.5×10^(11) Jones,and a broadband photoresponse ranging from ultraviolet to near-infrared(325–980 nm)are achieved at zero bias.This study provides a strategy for developing high-performance self-powered broadband photodetectors based on 2D materials.
基金supported by the National Natural Science Foundation of China (Grants Nos.22076039,and 22176051)Natural Science Foundation of Henan Province (Grant No.222300420054)excellent Science and Technology Innovation Team of Henan Normal University (Grant No.2021TD03).
文摘Metal-organic frameworks are recognized as promising multifunctional materials,especially metal-organic framework-based photocatalysts,which are considered to be ideal photocatalytic materials.Herein,a new type of UiO-66/MoSe_(2) composite was prepared using the solvothermal method.The optimum composite was selected by adjusting the mass ratio of UiO-66 and MoSe_(2).X-ray diffraction analysis showed that the mass ratio influenced the crystal plane exposure rate of the composite,which may have affected its photocatalytic performance.The composite is composed of ultra-thin flower-like MoSe_(2) that wrapped around cubic UiO-66,a structure that increases the abundance of active sites for reactions and is more conducive to the separation of carriers.The photocatalytic properties of the composite were evaluated by measuring the degradation rate of Rhodamine B and the catalyst’s ability to reduce Cr(VI)-containing wastewater under visible light irradiation.Rhodamine B was decolorized completely in 120 min,and most of the Cr(VI)was reduced within 150 min.The photochemical mechanism of the complex was studied in detail.The existence of Mo^(6+)and oxygen vacancies,in addition to the Z-type heterojunction promote the separation of electrons and holes,which enhances the photocatalytic effect.
基金This work was supported by the National Key R&D Program of China(No.2021YFB3602000)the Fundamental Research Funds for the Central Universities(No.WK5290000003).
文摘There are significant differences in the extent of impurity incorporation on different crystallographic directions of GaN microstructures,and the impurity-related deep energy level behavior will have a significant impact on device performance.However,a comprehensive understanding of the effect of lateral growth on device performance has not been achieved due to the lack of comprehensive spatial distribution characterization of the optical behavior and impurity incorporation in GaN microstructures.We present a comprehensive study of the optical behavior and growth mechanism of self-assembled GaN microdisks using nanoscale spatially resolved cathodoluminescence(CL)mapping.We have found a clear growth orientation-dependent optical behavior of the lateral and vertical growth sectors of self-assembled GaN microcrystals.The lateral growth sector,i.e.,the{101¯1}-growth sector,forms six side facets of the microdisk and shows significant near-bandgap emission(NBE)and weak deep energy level luminescence.Cavity effect enhanced emission was found for the first time in such a truncated hexagonal Na-flux GaN microdisk system with an ultra-smooth surface(Ra<0.7 nm)and low stress.The self-assembled microdisk shows significant ultraviolet(UV)lasing action(main lasing peak wavelength 370.9 nm,quality factor 1278,threshold 6×10^(4)μJ/cm^(2))under pulsed optical pumping.We believe that the appearance of UV lasing action may be related to the light limitation on the six side facets of the lateral growth of the GaN microdisk,the high structural quality,the low content of deep energy level defects,the low surface roughness,and the low stress.
基金This work was supported by the Key R&D Project of Xinjiang Uygur Autonomous Region(Grant No.2022B02022-2)the Key R&D Project of Xinjiang Uygur Autonomous Region(Grant No.2022B02023-3)+3 种基金the Agricultural Science and Technology Promotion and Service Project of Xinjiang Uygur Autonomous Region(Grant No.NTFW-2022-17)the Tianshan Innovation Team Project of Xinjiang Uygur Autonomous Region(Grant No.2020D14037)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2019D01A45)the National Natural Science Foundation of China(Grant No.51865058).
文摘In Xinjiang,in the process of whole stalk harvesting of cotton stalks,there is a problem that the cotton stalks are easily pulled off,and there is an urgent need to develop flexible stalk-pulling machines.Through literature,patent summary,and field research,it is found that domestic researchers have designed many kinds of machines for the problem of easy breaking of cotton stalks,but there is no flexible cotton stalk-pulling machine for the time being.In this study,two flexible cotton stalk-pulling machines were intended to address the problem of easy breakage of cotton stalks.On the basis of the first-generation machine,the design of the second-generation machine was improved.In order to further improve the operational performance of the flexible cotton stalks pulling tools,the operational mechanism of the core working parts of the tools was analyzed and a comparative test was done in a large field.Analysis and the comparative tests proved that improving the clamping working stroke s of the stalk-pulling components can effectively reduce the cotton stalks leakage rate.By using a flexible clamping process,a part of the deformation of cotton stalks can be transferred to the flexible material.To a certain extent,the deformation length L of the contact surface between the cotton stalk and the stalk pulling part is reduced,and the deformation displacementΔy is correspondingly lower.The toughness of the cotton stalk is not significantly decreased and the cotton stalk does not break easily.The improved second-generation machine has a 3.67% to 3.79% lower cotton stalks leakage rate and a 5.65% to 6.30% lower cotton stalks breakage rate than the first-generation machine.As the land in Xinjiang is clay soil,soil bonding to cotton stalks pulling force F2 is larger,resulting in cotton stalks being more difficult to be pulled out of the machine at once.The test proved that the improved second-generation implements had a significant improvement in the cotton stalk-pulling effect because of the subsequent pulling interval CD.The test results verify the analysis results and the research results can provide a theoretical basis for the subsequent structural improvement and performance enhancement of the flexible cotton stalk-pulling machine,which is of reference significance for solving the problem that the cotton stalks are easily pulled and broken in Xinjiang,China.
基金Dr Sophien Kaumoun from The Sainsbury Laboratory for providing pGR106:Avr3a23-147Dr Chua Nam-Hai at Rockefeller University for providing vector pTA7002Supported by the National Natural Science Foundation of China(30671319)
文摘Late blight is the most devastating potato disease and it also causes serious yield loss in tomato.Several disease resistance genes (R genes) to late blight have been cloned from potato in the past decade.However,the resistance mechanisms remain elusive.Tomato and potato belong to the botanical family Solanaceace and share remarkably conserved genome structure.Since tomato is a model system in genetic and plant pathology research,we used tomato to develop a powerful mutant screening system that will greatly facilitate the analysis of the signaling pathway of resistance to Phytophthora infestans.First we proved that the R3a transgenic tomatoes developed specific hypersensitive cell death response (HR) to P.infestans strains carrying the corresponding avirulence gene Avr3a,indicating that the signaling pathway from the R3a-Avr3a recognition to HR is conserved between potato and tomato.Second,we generated transgenic tomatoes carrying both R3a and Avr3a genes,with the latter under the control of a glucocorticiod-inducible promoter.Dexamethasone induced expression of Avr3a and resulted in localized HR.This versatile system can be used to construct a mutant library to screen surviving mutants whose resistance signal transduction was interrupted,providing the basis to identify key genes involved in the resistance to late blight in Solanaceae.
基金funded by 2016 National Key Research and Development Plan(grant number 2016YFC0803103)Research on Key Technology of Agricultural Remote Sensing Monitoring(grant number 12210243)and Henan Provincial University Innovation Team Support Plan(grant number 14IRTSTHN026).
文摘The leaf area index(LAI)is an important agroecological physiological parameter affecting vegetation growth.To apply the genetic algorithms neural network model(GANNM)to the remote sensing inversion of winter wheat LAI throughout the growth cycle and based on GaoFen-3 Synthetic aperture radar(GF-3 SAR)images and GaoFen-1 Wide Field of View(GF-1 WFV)images,the Xiangfu District in the east of Kaifeng City,Henan Province,was selected as the testing region.Winter wheat LAI data from five growth stages were combined,and optical and microwave polarization decomposition vegetation index models were used.The backscattering coefficient was extracted by modified water cloud model(MWCM),and the LAI was obtained by MWCM inversion as input factors to construct GANNM to invert LAI.The root mean square error(RMSE)and determination coefficient(R2)were used as evaluation indicators of the model.The fitting accuracy of winter wheat LAI in five growth stages by GANNM inversion was better than that of the BP neural network model;the R2 was higher than 0.8,and RMSE was lower than 0.3,indicating that the model could accurately invert the growth status of winter wheat in five growth stages.
文摘Background: The transcription factor Homeobox C8 (HOXC8) is overexpressed and regulates many important genes involved in the proliferation and invasion of many malignant tumors. However, the function of HOXC8 in gliomas remains unclear. Method: Based on the Chinese Glioma Genome Atlas (CGGA) set, HOXC8 expression is negatively correlated with overall survival (OS). Small interfering RNA (si-HOXC8) was used to downregulate the mRNA and protein expression levels of HOXC8 to assess glioma cell proliferation, migration and invasion. Results: Patients with higher HOXC8 levels showed poorer prognosis. DAVID analysis results indicated that HOXC8 was related to cell cycle, cell adhesion and immune response. In U251 and LN229 glioma cells treated with small interfering RNA for HOXC8 (si-HOXC8) for gene knockdown, significantly lower cell capacity of growth, migration and invasion was observed. Moreover, HOXC8 knockdown could reduce the protein expression of classical epithelial mesenchymal transition (EMT) related markers. Conclusion: HOXC8 may play an important role in glioma proliferation, migration and invasion. These findings indicated that HOXC8 may constitute a novel target for glioma treatment.
基金supported financially by the National Key Research and Development Program of China(Nos.2018YFA0209101 and 2017YFA0700503)the National Natural Science Foundation of China(Nos.11734005 and 61704024)+3 种基金the Science&Technology Project of Jiangsu Province(Nos.BE2016177 and BK20170696)the Fundamental Research Funds for the Central UniversitiesZhishan Young Scholar Fundthe Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Surface-enhanced Raman spectroscopy(SERS)has been successfully applied to detect various biomolecules,but it is still in challenge to assay living cells or bacteria sensitively,selectively and quantitatively in complex environments.In this paper,4-ATP and DTNB are assembled on Ag nanoparticle(NP)-decorated poly(styrene-co-acrylic acid)(PSA)nanospheres and then sealed by silica shells to form sensitive SERS labels based on the localized surface plasmon resonance of Ag NPs and large light scattering cross-sections of PSA nanospheres.They are further developed as encoding tags for dual detection of S.aureus and E.coli after assembling corresponding aptamers,which demonstrate ultralow detection limits of 8 cell L-1 for S.aureus and 2 cell L-1 for E.coli.Such a bioassay indicates a point-of-care strategy of ultrasensitively biomedical detections by encoding specific SERS tags.
基金funded by Scientific and Technological Innovation Team of Universities in Henan Province,grant number 22IRTSTHN008Innovative Research Team(in Philosophy and Social Science)in University of Henan Province grant number 2022-CXTD-02the National Natural Science Foundation of China,grant number 41371524.
文摘Super-pixel algorithms based on convolutional neural networks with fuzzy C-means clustering are widely used for high-spatial-resolution remote sensing images segmentation.However,this model requires the number of clusters to be set manually,resulting in a low automation degree due to the complexity of the iterative clustering process.To address this problem,a segmentation method based on a self-learning super-pixel network(SLSP-Net)and modified automatic fuzzy clustering(MAFC)is proposed.SLSP-Net performs feature extraction,non-iterative clustering,and gradient reconstruction.A lightweight feature embedder is adopted for feature extraction,thus expanding the receiving range and generating multi-scale features.Automatic matching is used for non-iterative clustering,and the overfitting of the network model is overcome by adaptively adjusting the gradient weight parameters,providing a better irregular super-pixel neighborhood structure.An optimized density peak algorithm is adopted for MAFC.Based on the obtained super-pixel image,this maximizes the robust decision-making interval,which enhances the automation of regional clustering.Finally,prior entropy fuzzy C-means clustering is applied to optimize the robust decision-making and obtain the final segmentation result.Experimental results show that the proposed model offers reduced experimental complexity and achieves good performance,realizing not only automatic image segmentation,but also good segmentation results.
