Understanding the differences in mechanical properties and damage characteristics of granitoid under high temperatures is crucial for exploring deep geothermal resources.This study analyzes the evolution of the acoust...Understanding the differences in mechanical properties and damage characteristics of granitoid under high temperatures is crucial for exploring deep geothermal resources.This study analyzes the evolution of the acoustic emission(AE)characteristics and mechanical parameters of granodiorite and granite after heating and water cooling by uniaxial compression and variable-angle shear tests under different temperature gradients.We identify their changes in mesostructure and mineral composition with electron probe microanalysis and scanning electron microscopy.Results show that these two hot dry rocks have similar diagenetic minerals and microstructure,but show significantly different mechanical and acoustic characteristics,and even opposing evolution trends in a certain temperature range.At the temperatures ranging from 100℃to 500℃,the compressive and shear mechanical properties of granodiorite switch repeatedly between weakening and strengthening,and those of granite show a continuous weakening trend.At 600℃,both rocks exhibit a deterioration of mechanical properties.The damage mode of granite is characterized by initiating at low stress,exponential evolutionary activity,and intensified energy release.In contrast,granodiorite exhibits the characteristics of initiating at high stress,volatile evolutionary activity,and intermittent energy release,due to its more stable microstructure and fewer thermal defects compared to granite.As the temperature increases,the initiation and propagation of secondary cracks in granodiorite are suppressed to a certain extent,and the seismicity and brittleness are enhanced.The subtle differences in grain size,microscopic heterogeneity,and mineral composition of the two hot dry rocks determine the different acoustic-mechanical characteristics under heating and cooling,and the evolution trends with temperature.These findings are of great significance for the scientific and efficient construction of rock mass engineering by rationally utilizing different rock strata properties.展开更多
The rock fracture characteristics and principal stress directions are crucial for prevention of geological disasters.In this study,we carried out biaxial compression tests on cubic granite samples of 100 mm in side le...The rock fracture characteristics and principal stress directions are crucial for prevention of geological disasters.In this study,we carried out biaxial compression tests on cubic granite samples of 100 mm in side length with different intermediate principal stress gradients in combination with acoustic emission(AE)technique.Results show that the fracture characteristics of granite samples change from‘sudden and aggregated’to‘continuous and dispersed’with the increase of the intermediate principal stress.The effect of increasing intermediate principal stress on AE amplitude is not significant,but it increases the proportions of high-frequency AE signals and shear cracks,which in turn increases the possibility of unstable rock failure.The difference of stress in different directions causes the anisotropy of rock fracture and thus leads to the obvious anisotropic characteristics of wave velocity variations.The anisotropy of wave velocity variations with stress difference is probable to identify the principal stress directions.The AE characteristics and the anisotropy of wave velocity variations of granite under two-dimensional stress are not only beneficial complements for rock fracture characteristic and principal stress direction identification,but also can provide a new analysis method for stability monitoring in practical rock engineering.展开更多
原发灶不明肿瘤(cancer of unknown primary,CUP)是一种细胞异质性显著并且具有高度恶性表型的转移性疾病,并且很难通过常规的检查手段被检测出其原发灶。一些新的检测手段,如基因表达谱检测、肿瘤表观遗传学检测、液体活检等手段逐渐...原发灶不明肿瘤(cancer of unknown primary,CUP)是一种细胞异质性显著并且具有高度恶性表型的转移性疾病,并且很难通过常规的检查手段被检测出其原发灶。一些新的检测手段,如基因表达谱检测、肿瘤表观遗传学检测、液体活检等手段逐渐应用于CUP原发灶的确定上,基于此出现的器官特异性治疗、靶向治疗、免疫治疗等也均有较大的应用前景,其有望提高CUP患者诊断的精确性和特异性,延长患者生存时间,改善患者生存质量。本文针对CUP的前沿诊断技术和治疗选择及其进展进行综述。展开更多
Dear Editor Legumes,the second-largest family of crops,contribute over one-third of human dietary proteins.Soybean(Glycine max L.),common bean(Phaseolus vulgaris L.),pea(Pisum sativum L.),and cowpea(Vigna unguiculata ...Dear Editor Legumes,the second-largest family of crops,contribute over one-third of human dietary proteins.Soybean(Glycine max L.),common bean(Phaseolus vulgaris L.),pea(Pisum sativum L.),and cowpea(Vigna unguiculata L.)are among the most widely culti-vated crop legumes for grain and vegetable and are essential for food security globally.展开更多
The characteristics of rock instability precursors and the principal stress direction are very crucial for the prevention of geological disasters.This study investigated the qualitative relationship between rock insta...The characteristics of rock instability precursors and the principal stress direction are very crucial for the prevention of geological disasters.This study investigated the qualitative relationship between rock instability precursors and principal stress direction through wave velocity in rock acoustic emission(AE)experiments.Results show that the wave velocity variation exhibits obvious anisotropic characteristics in 0%–20%and 60%–90%of peak strength due to the differences of stress-induced microcrack types.The amplitude of wave velocity variation is related to the azimuth and position of wave propagation path,which indicates that the principal stress direction can be identified by the anisotropic characteristics of wave velocity variations.Furthermore,the experiments also demonstrate that the AE event rate and wave velocity show quiet and stable variations in the elastic stage of rock samples,while they present a trend of active and unstable variations in the plastic stage.It implies that both the AE event rate and wave velocity are effective monitoring parameters for rock instability.The anisotropic characteristics of the wave velocity variation and AE event rate are beneficial complements for identifying the rock instability precursors and determining the principal stress direction,which provides a new analysis method for stability monitoring in practical rock engineering.展开更多
The bHLH transcription factors play pivotal roles in plant growth and development,production of secondary metabolites and responses to various environmental stresses.Although the bHLH genes have been well studied in m...The bHLH transcription factors play pivotal roles in plant growth and development,production of secondary metabolites and responses to various environmental stresses.Although the bHLH genes have been well studied in model plant species,a comprehensive investigation of the bHLH genes is required for tobacco with newly obtained high-quality genome.In the present study,a total of 309 NtbHLH genes were identified and can be divided into 23 subfamilies.The conserved amino acids which are essential for their function were predicted for the NtbHLH proteins.Moreover,the NtbHLH genes were conserved during evolution through analyzing the gene structures and conserved motifs.A total of 265 NtbHLH genes were localized in the 24 tobacco chromosomes while the remained 44 NtbHLH genes were mapped to the scaffolds due to the complexity of tobacco genome.Moreover,transcripts of NtbHLH genes were obviously tissue-specific expressed from the gene-chip data from 23 tobacco tissues,and expressions of 20 random selected NtbHLH genes were further confirmed by quantitative real-time PCR,indicating their potential functions in the plant growth and development.Importantly,overexpressed NtbHLH86 gene confers improve drought tolerance in tobacco indicating that it might be involved in the regulation of drought stress.Therefore,our findings here provide a valuable information on the characterization of NtbHLH genes and further investigation of their functions in tobacco.展开更多
Purpose: This study intends to examine the factors that influence Chinese college students' use of the Internet for acquiring information. Design/methodology/approach: This paper developed the research model by us...Purpose: This study intends to examine the factors that influence Chinese college students' use of the Internet for acquiring information. Design/methodology/approach: This paper developed the research model by using the technology acceptance model(TAM) and information system success model as the theoretical foundation. The proposed model was empirically tested with the structural equation modeling technique based on data collected from a survey of 357 college students.Findings: The results show that 1) perceived ease of use, perceived usefulness and perceived playfulness all have a positive impact on the intention to use the Internet for acquiring information, 2) use context and system quality significantly influence perceived usefulness and perceived ease of use, and 3) service quality has a positive impact on perceived ease of use but not on perceived usefulness. Likewise information quality has no positive effect on perceived usefulness.Research limitations: The survey respondents were mainly from college students in Nanjing. We need to recruit college students in the western or other developing areas in China to further validate our findings.Practical implications: This study puts forward some feasible suggestions for university libraries to improve information organization and the use of digital library resources to better meet the needs of library users.Originality/value: This study provides insights into the understanding of the factors affecting college students' online information acquisition from multiple perspectives.展开更多
The basic education in the new period has changed quickly, and all kinds of education departments have strengthened safety education by various approaches;however, the students' safety accidents across the country...The basic education in the new period has changed quickly, and all kinds of education departments have strengthened safety education by various approaches;however, the students' safety accidents across the country have still happened frequently, so the people have spontaneously paid attention to and reflected on the students' safety education issue, especially the safety education in the elementary schools where the students are younger. In this paper, the village elementary schools in the counties have been taken as the research object, and the research methods such as documentary method and interview method have been adopted to analyze the current situation of safety education in the village elementary schools in Nanxian County from the aspects such as safety education management, safety education content, safety education awareness, safety education effect and safety education approach.展开更多
Incorporation of siloxane-functionalized units into polymers backbone has proven to be an efficient strategy to improve photovoltaic performance. In this work, a low-cost siloxane-containing unit was developed to cons...Incorporation of siloxane-functionalized units into polymers backbone has proven to be an efficient strategy to improve photovoltaic performance. In this work, a low-cost siloxane-containing unit was developed to construct a series of terpolymers, and the effects of siloxane on the polymer performance were systematically studied. Different contents of thiophene containing siloxane-functionalized side chain were introduced into PM6 to obtain a series of polymers(PM6, PM6-SiO-10, PM6-SiO-20 and PM6-SiO-30). The siloxane-functionalized side chains in polymers have only a slight effect on the absorption behavior and frontier molecular orbitals. However, when the siloxane content increased, the terpolymers' aggregation property decreased and the temperature-dependency increased, leading to improved donor-acceptor compatibility. The power conversion efficiency(PCE) based on PM6:Y6, PM6-SiO-20:Y6 and PM6-SiO-30:Y6 devices was 15.64%, 16.03% and 15.82%, respectively. In comparison, the active layer based on PM6-SiO-10:Y6 exhibits the most appropriate phase separation morphology, resulting in effective exciton dissociation, more balanced hole-electron transport and less recombination. Consequently, the highest PCE of 16.69% with an outstanding shortcircuit current density of 26.96 mA·cm^(-2) was obtained, which are one of the highest values for siloxane-functionalized polymer-based devices.This work demonstrates that finely controlling the content of siloxane-functionalized thiophene is beneficial for obtaining high-performance terpolymer donors and provides a novel and low-cost method to improve photovoltaic performance.展开更多
The development of n-type semiconductor is still far behind that of p-type semiconductor on account of the challenges in enhancing carrier mobility and environmental stability.Herein,by blending with the polymers,n-ty...The development of n-type semiconductor is still far behind that of p-type semiconductor on account of the challenges in enhancing carrier mobility and environmental stability.Herein,by blending with the polymers,n-type ultrathin crystalline thin film was successfully prepared by the method of meniscus-guided coating.Remarkably,the n-type crystalline films exhibit ultrathin thickness as low as 5 nm and excellent mobility of 1.58 cm^(2) V^(-1) s^(-1),which is outstanding in currently reported organic n-type transistors.Moreover,the PS layer provides a high-quality interface with ultralow defect which has strong resistance to external interference with excellent long-term stability,paving the way for the application of n-type transistors in logic circuits.展开更多
Flow field data generated by ocean models are important for simulating ocean currents and circulation patterns,which are essential components in digital Earth construction.To evaluate the accuracy of model-simulatedfl...Flow field data generated by ocean models are important for simulating ocean currents and circulation patterns,which are essential components in digital Earth construction.To evaluate the accuracy of model-simulatedflow felds,Array for Real-timeGeostrophic Oceanography(Argo)float observations can be considered benchmarks.In this study,a novel method for comparing Argo profiles with 3-dimensional trajectories obtained by simulating Argo floats in Hybrid Coordinate Ocean Model(HYCOM)-provided flow fields was proposed.Surface and subsurface trajectories were calculated,and their spatial matching characteristics were analyzed.The results demonstrated that(1)the HYCOM surface and subsurface flow felds generally conform to the basic characteristics and trends of ocean currents;(2)the HYCOM sea surface current field error pattern exhibits a symmetrical distribution centered on the equator in the Northern and Southern Hemispheres and increases with increasing latitude;and(3)the HYCOM subsurface flow field exhibits regional differences,with the largest differences in the Gulf Stream,North Atlantic Warm Current,and Westerly Wind Drift region.Through analysis of the disparities between HYCOM and Argo data,the effectiveness of using model simulation data can be enhanced,and the accuracy and dependability of ocean models can be improved.展开更多
Although VEGF-B was discovered as a VEGF-A homolog a long time ago,the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups.Notwithstanding,drugs that inhibit V...Although VEGF-B was discovered as a VEGF-A homolog a long time ago,the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups.Notwithstanding,drugs that inhibit VEGF-B together with other VEGF family members are being used to treat patients with various neovascular diseases.It is therefore critical to have a better understanding of the angiogenic effect of VEGF-B and the underlying mechanisms.Using comprehensive in vitro and in vivo methods and models,we reveal here for the first time an unexpected and surprising function of VEGF-B as an endogenous inhibitor of angiogenesis by inhibiting the FGF2/FGFR1 pathway when the latter is abundantly expressed.Mechanistically,we unveil that VEGF-B binds to FGFR1,induces FGFR1/VEGFR1 complex formation,and suppresses FGF2-induced Erk activation,and inhibits FGF2-driven angiogenesis and tumor growth.Our work uncovers a previously unrecognized novel function of VEGF-B in tethering the FGF2/FGFR1 pathway.Given the anti-angiogenic nature of VEGF-B under conditions of high FGF2/FGFR1 levels,caution is warranted when modulating VEGF-B activity to treat neovascular diseases.展开更多
Semiconducting two-dimensional conjugated polymers(2DCPs)with strong fluorescence emission have great potential for various optoelectronic applications.However,it is enormously challenging to achieve this goal due to ...Semiconducting two-dimensional conjugated polymers(2DCPs)with strong fluorescence emission have great potential for various optoelectronic applications.However,it is enormously challenging to achieve this goal due to the significant compact interlayerπ-πstacking-induced quenching effect in these systems.In this work,we found that highly fluorescent semiconducting 2DCPs can be prepared through an effective side-chain engineering approach in which interlayer spacers are introduced to reduce the fluorescence quenching effect.The obtained two truxene-based 2DCP films that,along with-C6H13 and-C_(12)H_(25)alkyl side chains as interlayer spacers both demonstrate superior fluorescence properties with a high photoluminescence quantum yield of 5.6%and 14.6%,respectively.These are among the highest values currently reported for 2DCP films.Moreover,an ultralong isotropic quasi-twodimensional exciton diffusion length constrained in the plane with its highest value approaching 110 nm was revealed by the transient photoluminescence microscopy technique,suggesting that theπ-conjugated structure in these truxene-based 2DCP films has effectively been extended.This work can enable a broad exploration of highly fluorescent semiconducting 2DCP films for more deeply fundamental properties and optoelectronic device applications.展开更多
Zircon U-Pb ages, Hf isotope data and whole-rock major and trace element data for the Middle to Late Ordovician gabbros and granites in the Erguna Massif, NE China were presented in this paper. The petrogenesis of the...Zircon U-Pb ages, Hf isotope data and whole-rock major and trace element data for the Middle to Late Ordovician gabbros and granites in the Erguna Massif, NE China were presented in this paper. The petrogenesis of these rocks and the Early Paleozoic tectonic evolution of the massif were discussed. Zircons from the granites and gabbros are of magmatic origin based on their cathodoluminescence(CL) images. The 206Pb/238 U ages obtained from 20 spots on zircons from the granites range from 446±9 to 464±10 Ma, yielding a weighted mean age of 455±10 Ma; and 16 spots on zircons from the gabbros range from 465±10 to 466±7 Ma, yielding a weighted mean age of 465±2 Ma. Chemically, the Late Ordovician granites in the Erguna Massif are weakly peraluminous and similar to A-type granites. The granites and gabbros are all enriched in light rare earth elements and large ion lithophile elements(e.g., Rb, K), and depleted in heavy rare earth elements and high field strength elements(e.g., Nb, Ta, and Ti); they all exhibit marked negative Eu anomalies. Their zircon εHf(t) values range mainly from +1.86 to +6.21(for the granites) and +1.39 to +3.89(for the gabbros), except for one spot with a value of-0.27(for a gabbro). The TDM1 ages for the gabbros and TDM2 ages for the granites vary from 928 to 1 091 Ma and from 1 287 to 1 675 Ma, respectively. It is concluded that the primary magma of the granites could have been derived by partial melting of Mesoproterozoic newly accreted crustal material, whereas the primary magma of the gabbros originated by partial melting of a depleted mantle wedge that had been metasomatized by fluids derived from a subducted slab. These Middle–Late Ordovician granites and gabbros constitute a typical bimodal igneous rock association, implying an extensional environment that was probably related to the post-collisional development of the Erguna and Xing'an massifs in the early Early Paleozoic.展开更多
Urban expansion is a hot topic in land use/land cover change(LUCC)researches.In this paper,maximum entropy model and cellular automata(CA)model are coupled into a new CA model(Maxent-CA)for urban expansion.This model ...Urban expansion is a hot topic in land use/land cover change(LUCC)researches.In this paper,maximum entropy model and cellular automata(CA)model are coupled into a new CA model(Maxent-CA)for urban expansion.This model can help to obtain transition rules from single-period dataset.Moreover,it can be constructed and calibrated easily with several steps.Firstly,Maxent-CA model was built by using remote sensing data of China in 2000(basic data)and spatial variables(such as population density and Euclidean distance to cities).Secondly,the proposed model was calibrated by analyzing training samples,neighborhood structure and spatial scale.Finally,this model was verified by comparing logistic regression CA model and their simulation results.Experiments showed that suitable sampling ratio(sampling ratio equals the proportion of urban land in the whole region)and von Neumann neighborhood structure will help to yield better results.Spatial structure of simulation results becomes simple as spatial resolution decreases.Besides,simulation accuracy is significantly affected by spatial resolution.Compared to simulation results of logistic regression CA model,Maxent-CA model can avoid clusters phenomenon and obtain better results matching actual situation.It is found that the proposed model performs well in simulating urban expansion of China.It will be helpful for simulating even larger study area in the background of global environment changes.展开更多
Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid ...Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid growth in the material demand for fibers,and the development of green and high-performance biomass-based fibers has become an important research topic to reduce the dependence on synthetic fiber materials and the harm to the environment.Here,chitosan is first prepared from the waste material by chemical methods.Then the chitosan-based self-powered induction fibers are prepared by electrospinning core wire technique.Chitosan-based self-powered sensing fiber is ultra-light and flexible,which can achieve about 2500 collisions without damaging the surface.Chitosan-based self-powered sensing fiber can also be used in smart home sensing applications to control home appliance switches with a light touch,which has a great application prospect in smart home and wearable fields.展开更多
Background:Liver cancer as the main leading cancer has caused heavy burdens globally.The prognosis of liver cancer is closely related with postoperative nutrition support.Corn oligopeptides(COPs)are protein hydrolysat...Background:Liver cancer as the main leading cancer has caused heavy burdens globally.The prognosis of liver cancer is closely related with postoperative nutrition support.Corn oligopeptides(COPs)are protein hydrolysates produced by enzymatic treatments,which have shown potential bioactivities,such as inhibiting angiotensin I-converting enzyme,resisting lipid peroxidation and anti-oxidant.However,the correlation between COPs and liver cancer patients is still unknown and the potential mechanism of COPs on liver cancer is unclear as well.The aim of this study was to assess effects of 7-day intervention of COPs after surgery on liver function and serum metabolic profiles of liver cancer patients.Methods:Patients were assigned into COPs intervention group(n=50)and control group(n=91)for 7 days.Investigations were scheduled at 1st day and 7th day after liver resection surgery respectively,mainly including anthropometric,biochemical indexes and liquid chromatography-mass spectrometry(LC/MS)analysis.Results:Seven-day supplementation of COPs on early post-surgery liver cancer patients down-regulated levels of alanine aminotransferase,aspartate aminotransferase,total bilirubin,direct bilirubin and up-regulated prothrombin time activity and prealbumin levels.LC/MS analysis revealed metabolic signatures including regulation of 16 metabolites,which was closely related with two metabolic pathways(nicotinate and nicotinamide metabolism,fatty acid metabolism).Conclusions:COPs supplementation has displayed the potentials on alleviating the injury of liver function and it may be due to regulation of fatty acid metabolism,nicotinate and nicotinamide metabolism,lipid peroxidation and anti-inflammatory action.More researches are warranted in future to confirm the exact mechanisms.展开更多
基金The authors would like to acknowledge the financial support from the National Natural Science Foundation of China(Grant No.52104112)the Research Foundation of the Department of Natural Resources of Hunan Province,China(Grant No.20230101DZ)the Natural Science Foundation of Hunan Province,China(Grant No.2023JJ20062).
文摘Understanding the differences in mechanical properties and damage characteristics of granitoid under high temperatures is crucial for exploring deep geothermal resources.This study analyzes the evolution of the acoustic emission(AE)characteristics and mechanical parameters of granodiorite and granite after heating and water cooling by uniaxial compression and variable-angle shear tests under different temperature gradients.We identify their changes in mesostructure and mineral composition with electron probe microanalysis and scanning electron microscopy.Results show that these two hot dry rocks have similar diagenetic minerals and microstructure,but show significantly different mechanical and acoustic characteristics,and even opposing evolution trends in a certain temperature range.At the temperatures ranging from 100℃to 500℃,the compressive and shear mechanical properties of granodiorite switch repeatedly between weakening and strengthening,and those of granite show a continuous weakening trend.At 600℃,both rocks exhibit a deterioration of mechanical properties.The damage mode of granite is characterized by initiating at low stress,exponential evolutionary activity,and intensified energy release.In contrast,granodiorite exhibits the characteristics of initiating at high stress,volatile evolutionary activity,and intermittent energy release,due to its more stable microstructure and fewer thermal defects compared to granite.As the temperature increases,the initiation and propagation of secondary cracks in granodiorite are suppressed to a certain extent,and the seismicity and brittleness are enhanced.The subtle differences in grain size,microscopic heterogeneity,and mineral composition of the two hot dry rocks determine the different acoustic-mechanical characteristics under heating and cooling,and the evolution trends with temperature.These findings are of great significance for the scientific and efficient construction of rock mass engineering by rationally utilizing different rock strata properties.
基金the financial support from National Key Research and Development Program of China(2021YFC2900500)Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(52161135301).
基金This work was financially supported by the National Key Research and Development Program of China(Grant No.2021YFC2900500)the International(Regional)Cooperation and Exchange Program of National Natural Science Foundation of China(Grant No.52161135301)the Special Fund for Basic Scientific Research Operations in Universities(Grant No.2282020cxqd055).
文摘The rock fracture characteristics and principal stress directions are crucial for prevention of geological disasters.In this study,we carried out biaxial compression tests on cubic granite samples of 100 mm in side length with different intermediate principal stress gradients in combination with acoustic emission(AE)technique.Results show that the fracture characteristics of granite samples change from‘sudden and aggregated’to‘continuous and dispersed’with the increase of the intermediate principal stress.The effect of increasing intermediate principal stress on AE amplitude is not significant,but it increases the proportions of high-frequency AE signals and shear cracks,which in turn increases the possibility of unstable rock failure.The difference of stress in different directions causes the anisotropy of rock fracture and thus leads to the obvious anisotropic characteristics of wave velocity variations.The anisotropy of wave velocity variations with stress difference is probable to identify the principal stress directions.The AE characteristics and the anisotropy of wave velocity variations of granite under two-dimensional stress are not only beneficial complements for rock fracture characteristic and principal stress direction identification,but also can provide a new analysis method for stability monitoring in practical rock engineering.
文摘原发灶不明肿瘤(cancer of unknown primary,CUP)是一种细胞异质性显著并且具有高度恶性表型的转移性疾病,并且很难通过常规的检查手段被检测出其原发灶。一些新的检测手段,如基因表达谱检测、肿瘤表观遗传学检测、液体活检等手段逐渐应用于CUP原发灶的确定上,基于此出现的器官特异性治疗、靶向治疗、免疫治疗等也均有较大的应用前景,其有望提高CUP患者诊断的精确性和特异性,延长患者生存时间,改善患者生存质量。本文针对CUP的前沿诊断技术和治疗选择及其进展进行综述。
基金This work was supported by the National Key Research&Development Program of China(2022YFE0198000)the National Nature Science Foundation of China(32202470,32202521)+1 种基金the State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products(2021 DC700024-KF202217)the Natural Science Foundation of Zhejiang Province(LQ21C150004).
文摘Dear Editor Legumes,the second-largest family of crops,contribute over one-third of human dietary proteins.Soybean(Glycine max L.),common bean(Phaseolus vulgaris L.),pea(Pisum sativum L.),and cowpea(Vigna unguiculata L.)are among the most widely culti-vated crop legumes for grain and vegetable and are essential for food security globally.
基金the financial support from the Fundamental Research Funds for the Central Universities(No.2282020cxqd055)the National Science Foundation for Excellent Young Scholars of China(No.51822407)+1 种基金the Natural Science Foundation of China(Nos.51774327 and 51504288)the Fundamental Research Funds for the Central Universities of Central South University(No.2021zzts0862)。
文摘The characteristics of rock instability precursors and the principal stress direction are very crucial for the prevention of geological disasters.This study investigated the qualitative relationship between rock instability precursors and principal stress direction through wave velocity in rock acoustic emission(AE)experiments.Results show that the wave velocity variation exhibits obvious anisotropic characteristics in 0%–20%and 60%–90%of peak strength due to the differences of stress-induced microcrack types.The amplitude of wave velocity variation is related to the azimuth and position of wave propagation path,which indicates that the principal stress direction can be identified by the anisotropic characteristics of wave velocity variations.Furthermore,the experiments also demonstrate that the AE event rate and wave velocity show quiet and stable variations in the elastic stage of rock samples,while they present a trend of active and unstable variations in the plastic stage.It implies that both the AE event rate and wave velocity are effective monitoring parameters for rock instability.The anisotropic characteristics of the wave velocity variation and AE event rate are beneficial complements for identifying the rock instability precursors and determining the principal stress direction,which provides a new analysis method for stability monitoring in practical rock engineering.
基金funded by the National Natural Science Foundation of China(grant number 31760072 to G.Bai,and grant number 31860413 to H.Xie)Yunnan Applied Basic Research Project(grant number 202001AT070010 to G.Bai)the Yunnan Academy of Tobacco Agricultural Sciences(grant numbers YNTC-2016YN22 and CNTC-110202001025(JY08)to H.Xie,YNTC-2016YN24,YNTC-2015YN02,YNTC-2018530000241002,and YNTC-2019530000241003 to D.-H.Yang).
文摘The bHLH transcription factors play pivotal roles in plant growth and development,production of secondary metabolites and responses to various environmental stresses.Although the bHLH genes have been well studied in model plant species,a comprehensive investigation of the bHLH genes is required for tobacco with newly obtained high-quality genome.In the present study,a total of 309 NtbHLH genes were identified and can be divided into 23 subfamilies.The conserved amino acids which are essential for their function were predicted for the NtbHLH proteins.Moreover,the NtbHLH genes were conserved during evolution through analyzing the gene structures and conserved motifs.A total of 265 NtbHLH genes were localized in the 24 tobacco chromosomes while the remained 44 NtbHLH genes were mapped to the scaffolds due to the complexity of tobacco genome.Moreover,transcripts of NtbHLH genes were obviously tissue-specific expressed from the gene-chip data from 23 tobacco tissues,and expressions of 20 random selected NtbHLH genes were further confirmed by quantitative real-time PCR,indicating their potential functions in the plant growth and development.Importantly,overexpressed NtbHLH86 gene confers improve drought tolerance in tobacco indicating that it might be involved in the regulation of drought stress.Therefore,our findings here provide a valuable information on the characterization of NtbHLH genes and further investigation of their functions in tobacco.
基金supported by the Special Fund for Fast Sharing of Science Paper in Net Era by the Chinese Ministry of Education, Science and Technology Development Center (Grant No.: FSSP2013044001)the Doctoral Fund of the Chinese Ministry of Education (Grant No.: 20130091110061)
文摘Purpose: This study intends to examine the factors that influence Chinese college students' use of the Internet for acquiring information. Design/methodology/approach: This paper developed the research model by using the technology acceptance model(TAM) and information system success model as the theoretical foundation. The proposed model was empirically tested with the structural equation modeling technique based on data collected from a survey of 357 college students.Findings: The results show that 1) perceived ease of use, perceived usefulness and perceived playfulness all have a positive impact on the intention to use the Internet for acquiring information, 2) use context and system quality significantly influence perceived usefulness and perceived ease of use, and 3) service quality has a positive impact on perceived ease of use but not on perceived usefulness. Likewise information quality has no positive effect on perceived usefulness.Research limitations: The survey respondents were mainly from college students in Nanjing. We need to recruit college students in the western or other developing areas in China to further validate our findings.Practical implications: This study puts forward some feasible suggestions for university libraries to improve information organization and the use of digital library resources to better meet the needs of library users.Originality/value: This study provides insights into the understanding of the factors affecting college students' online information acquisition from multiple perspectives.
文摘The basic education in the new period has changed quickly, and all kinds of education departments have strengthened safety education by various approaches;however, the students' safety accidents across the country have still happened frequently, so the people have spontaneously paid attention to and reflected on the students' safety education issue, especially the safety education in the elementary schools where the students are younger. In this paper, the village elementary schools in the counties have been taken as the research object, and the research methods such as documentary method and interview method have been adopted to analyze the current situation of safety education in the village elementary schools in Nanxian County from the aspects such as safety education management, safety education content, safety education awareness, safety education effect and safety education approach.
基金financially supported by the National Natural Science Foundation of China (NSFC) (Nos.51973032,21905043,51833004 and 52333006)the Jiangxi Provincial Natural Science Foundation (Nos.20212ACB203005,20224ACB214002,20212BAB213018 and 20224BAB203015)+2 种基金the Thousand Talents Plan of Jiangxi Province (No.jxsq2019101051)the Innovation Foundation for graduate students of Jiangxi Normal University (No.YJS2021018)the financial support from Research Grants Council (RGC) of Hong Kong (General Research Fund No.14303519)。
文摘Incorporation of siloxane-functionalized units into polymers backbone has proven to be an efficient strategy to improve photovoltaic performance. In this work, a low-cost siloxane-containing unit was developed to construct a series of terpolymers, and the effects of siloxane on the polymer performance were systematically studied. Different contents of thiophene containing siloxane-functionalized side chain were introduced into PM6 to obtain a series of polymers(PM6, PM6-SiO-10, PM6-SiO-20 and PM6-SiO-30). The siloxane-functionalized side chains in polymers have only a slight effect on the absorption behavior and frontier molecular orbitals. However, when the siloxane content increased, the terpolymers' aggregation property decreased and the temperature-dependency increased, leading to improved donor-acceptor compatibility. The power conversion efficiency(PCE) based on PM6:Y6, PM6-SiO-20:Y6 and PM6-SiO-30:Y6 devices was 15.64%, 16.03% and 15.82%, respectively. In comparison, the active layer based on PM6-SiO-10:Y6 exhibits the most appropriate phase separation morphology, resulting in effective exciton dissociation, more balanced hole-electron transport and less recombination. Consequently, the highest PCE of 16.69% with an outstanding shortcircuit current density of 26.96 mA·cm^(-2) was obtained, which are one of the highest values for siloxane-functionalized polymer-based devices.This work demonstrates that finely controlling the content of siloxane-functionalized thiophene is beneficial for obtaining high-performance terpolymer donors and provides a novel and low-cost method to improve photovoltaic performance.
基金the financial support of the National Key Research and Development Program(No.2022YFF1202700)National Natural Science Foundation of China(No.52121002)the Haihe Laboratory of Sustainable Chemical Transformations.
文摘The development of n-type semiconductor is still far behind that of p-type semiconductor on account of the challenges in enhancing carrier mobility and environmental stability.Herein,by blending with the polymers,n-type ultrathin crystalline thin film was successfully prepared by the method of meniscus-guided coating.Remarkably,the n-type crystalline films exhibit ultrathin thickness as low as 5 nm and excellent mobility of 1.58 cm^(2) V^(-1) s^(-1),which is outstanding in currently reported organic n-type transistors.Moreover,the PS layer provides a high-quality interface with ultralow defect which has strong resistance to external interference with excellent long-term stability,paving the way for the application of n-type transistors in logic circuits.
基金supported by National Natural Science Foundation of China[grant nos:41930648,42171406 and 42171465]National Key Research and Development Program of China[grant no:2021YFB3900901].
文摘Flow field data generated by ocean models are important for simulating ocean currents and circulation patterns,which are essential components in digital Earth construction.To evaluate the accuracy of model-simulatedflow felds,Array for Real-timeGeostrophic Oceanography(Argo)float observations can be considered benchmarks.In this study,a novel method for comparing Argo profiles with 3-dimensional trajectories obtained by simulating Argo floats in Hybrid Coordinate Ocean Model(HYCOM)-provided flow fields was proposed.Surface and subsurface trajectories were calculated,and their spatial matching characteristics were analyzed.The results demonstrated that(1)the HYCOM surface and subsurface flow felds generally conform to the basic characteristics and trends of ocean currents;(2)the HYCOM sea surface current field error pattern exhibits a symmetrical distribution centered on the equator in the Northern and Southern Hemispheres and increases with increasing latitude;and(3)the HYCOM subsurface flow field exhibits regional differences,with the largest differences in the Gulf Stream,North Atlantic Warm Current,and Westerly Wind Drift region.Through analysis of the disparities between HYCOM and Argo data,the effectiveness of using model simulation data can be enhanced,and the accuracy and dependability of ocean models can be improved.
基金This study is supported by the State Key Laboratory of Ophthalmology,Zhongshan Ophthalmic Center,Sun Yat-sen University,and Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science,Guangzhou 510060,P.R.Chinathe National Natural Science Foundation of China(82150710555 and 82220108016 to X.Li,81970823 to Jin Yao and 81830013 to J.O.)+4 种基金a Key Research and Development Plan of Shandong Province(2016GSF201100)the Fundamental Research Funds for the Central Universities(19ykpy151)the long-term structural Methusalem funding by the Flemish Government,Belgiumthe Deutsche Forschungsge-meinschaft(Project No.:394046768-SFB1366)the DZHK partner site Mannheim/Heidelberg to H.F.L.,an ERA PerMed 2020 JTC grant“PROGRESS”.
文摘Although VEGF-B was discovered as a VEGF-A homolog a long time ago,the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups.Notwithstanding,drugs that inhibit VEGF-B together with other VEGF family members are being used to treat patients with various neovascular diseases.It is therefore critical to have a better understanding of the angiogenic effect of VEGF-B and the underlying mechanisms.Using comprehensive in vitro and in vivo methods and models,we reveal here for the first time an unexpected and surprising function of VEGF-B as an endogenous inhibitor of angiogenesis by inhibiting the FGF2/FGFR1 pathway when the latter is abundantly expressed.Mechanistically,we unveil that VEGF-B binds to FGFR1,induces FGFR1/VEGFR1 complex formation,and suppresses FGF2-induced Erk activation,and inhibits FGF2-driven angiogenesis and tumor growth.Our work uncovers a previously unrecognized novel function of VEGF-B in tethering the FGF2/FGFR1 pathway.Given the anti-angiogenic nature of VEGF-B under conditions of high FGF2/FGFR1 levels,caution is warranted when modulating VEGF-B activity to treat neovascular diseases.
基金supported by the Ministry of Science and Technology of China(grant nos.2018YFA0703200 and 2022YFB3603800)the Natural Science Foundation of China(grant nos.21875259,52233010,51725304,61890943,and 22021002)+3 种基金the CAS Project for Young Scientists in Basic Research(grant no.YSBR-053)the Youth Innovation Promotion Association of the Chinese Academy of Sciences,the National Program for Support of Top-notch Young Professionals,the Beijing National Laboratory for Molecular Sciences(grant no.BNLMS-CXXM-202012)the Key Research Program of the Chinese Academy of Sciences(grant no.XDPB13)K.C.Wong Education Foundation(grant no.GJTD-2020-02).
文摘Semiconducting two-dimensional conjugated polymers(2DCPs)with strong fluorescence emission have great potential for various optoelectronic applications.However,it is enormously challenging to achieve this goal due to the significant compact interlayerπ-πstacking-induced quenching effect in these systems.In this work,we found that highly fluorescent semiconducting 2DCPs can be prepared through an effective side-chain engineering approach in which interlayer spacers are introduced to reduce the fluorescence quenching effect.The obtained two truxene-based 2DCP films that,along with-C6H13 and-C_(12)H_(25)alkyl side chains as interlayer spacers both demonstrate superior fluorescence properties with a high photoluminescence quantum yield of 5.6%and 14.6%,respectively.These are among the highest values currently reported for 2DCP films.Moreover,an ultralong isotropic quasi-twodimensional exciton diffusion length constrained in the plane with its highest value approaching 110 nm was revealed by the transient photoluminescence microscopy technique,suggesting that theπ-conjugated structure in these truxene-based 2DCP films has effectively been extended.This work can enable a broad exploration of highly fluorescent semiconducting 2DCP films for more deeply fundamental properties and optoelectronic device applications.
基金financially supported by the National Key Basic Research Program of China (Nos. 2013CB429802 and 2013CB429803)the National Natural Science Foundation of China (No. 41272077)by the Opening Foundation of the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan (No. GPMR201104)
文摘Zircon U-Pb ages, Hf isotope data and whole-rock major and trace element data for the Middle to Late Ordovician gabbros and granites in the Erguna Massif, NE China were presented in this paper. The petrogenesis of these rocks and the Early Paleozoic tectonic evolution of the massif were discussed. Zircons from the granites and gabbros are of magmatic origin based on their cathodoluminescence(CL) images. The 206Pb/238 U ages obtained from 20 spots on zircons from the granites range from 446±9 to 464±10 Ma, yielding a weighted mean age of 455±10 Ma; and 16 spots on zircons from the gabbros range from 465±10 to 466±7 Ma, yielding a weighted mean age of 465±2 Ma. Chemically, the Late Ordovician granites in the Erguna Massif are weakly peraluminous and similar to A-type granites. The granites and gabbros are all enriched in light rare earth elements and large ion lithophile elements(e.g., Rb, K), and depleted in heavy rare earth elements and high field strength elements(e.g., Nb, Ta, and Ti); they all exhibit marked negative Eu anomalies. Their zircon εHf(t) values range mainly from +1.86 to +6.21(for the granites) and +1.39 to +3.89(for the gabbros), except for one spot with a value of-0.27(for a gabbro). The TDM1 ages for the gabbros and TDM2 ages for the granites vary from 928 to 1 091 Ma and from 1 287 to 1 675 Ma, respectively. It is concluded that the primary magma of the granites could have been derived by partial melting of Mesoproterozoic newly accreted crustal material, whereas the primary magma of the gabbros originated by partial melting of a depleted mantle wedge that had been metasomatized by fluids derived from a subducted slab. These Middle–Late Ordovician granites and gabbros constitute a typical bimodal igneous rock association, implying an extensional environment that was probably related to the post-collisional development of the Erguna and Xing'an massifs in the early Early Paleozoic.
基金supported by the National Key R&D Program of China(Grant No.2017YFA0604404)the National Natural Science Foundation of China(Grant Nos.41801304&41871306)Educational Commission of Guangdong Province of China(Grant No.2016KTSCX045).
文摘Urban expansion is a hot topic in land use/land cover change(LUCC)researches.In this paper,maximum entropy model and cellular automata(CA)model are coupled into a new CA model(Maxent-CA)for urban expansion.This model can help to obtain transition rules from single-period dataset.Moreover,it can be constructed and calibrated easily with several steps.Firstly,Maxent-CA model was built by using remote sensing data of China in 2000(basic data)and spatial variables(such as population density and Euclidean distance to cities).Secondly,the proposed model was calibrated by analyzing training samples,neighborhood structure and spatial scale.Finally,this model was verified by comparing logistic regression CA model and their simulation results.Experiments showed that suitable sampling ratio(sampling ratio equals the proportion of urban land in the whole region)and von Neumann neighborhood structure will help to yield better results.Spatial structure of simulation results becomes simple as spatial resolution decreases.Besides,simulation accuracy is significantly affected by spatial resolution.Compared to simulation results of logistic regression CA model,Maxent-CA model can avoid clusters phenomenon and obtain better results matching actual situation.It is found that the proposed model performs well in simulating urban expansion of China.It will be helpful for simulating even larger study area in the background of global environment changes.
基金The authors are grateful for the support received from National Natural Science Foundation of China(Grant No.22109012)Natural Science Foundation of the Beijing Municipality(Grant No.2212052)the Fundamental Research Funds for the Central Universities(Grant No.E1E46805).
文摘Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid growth in the material demand for fibers,and the development of green and high-performance biomass-based fibers has become an important research topic to reduce the dependence on synthetic fiber materials and the harm to the environment.Here,chitosan is first prepared from the waste material by chemical methods.Then the chitosan-based self-powered induction fibers are prepared by electrospinning core wire technique.Chitosan-based self-powered sensing fiber is ultra-light and flexible,which can achieve about 2500 collisions without damaging the surface.Chitosan-based self-powered sensing fiber can also be used in smart home sensing applications to control home appliance switches with a light touch,which has a great application prospect in smart home and wearable fields.
基金We sincerely thank all support from National Key Research and Development Program of China(No.2016YFD0400604).
文摘Background:Liver cancer as the main leading cancer has caused heavy burdens globally.The prognosis of liver cancer is closely related with postoperative nutrition support.Corn oligopeptides(COPs)are protein hydrolysates produced by enzymatic treatments,which have shown potential bioactivities,such as inhibiting angiotensin I-converting enzyme,resisting lipid peroxidation and anti-oxidant.However,the correlation between COPs and liver cancer patients is still unknown and the potential mechanism of COPs on liver cancer is unclear as well.The aim of this study was to assess effects of 7-day intervention of COPs after surgery on liver function and serum metabolic profiles of liver cancer patients.Methods:Patients were assigned into COPs intervention group(n=50)and control group(n=91)for 7 days.Investigations were scheduled at 1st day and 7th day after liver resection surgery respectively,mainly including anthropometric,biochemical indexes and liquid chromatography-mass spectrometry(LC/MS)analysis.Results:Seven-day supplementation of COPs on early post-surgery liver cancer patients down-regulated levels of alanine aminotransferase,aspartate aminotransferase,total bilirubin,direct bilirubin and up-regulated prothrombin time activity and prealbumin levels.LC/MS analysis revealed metabolic signatures including regulation of 16 metabolites,which was closely related with two metabolic pathways(nicotinate and nicotinamide metabolism,fatty acid metabolism).Conclusions:COPs supplementation has displayed the potentials on alleviating the injury of liver function and it may be due to regulation of fatty acid metabolism,nicotinate and nicotinamide metabolism,lipid peroxidation and anti-inflammatory action.More researches are warranted in future to confirm the exact mechanisms.
