The retina of Wistar rats within 1-3 days of birth were dissociated into a retinal ceil suspension using 0.05% trypsin digestion. The cell suspension was incubated in Dulbecco＇s modified Eagle＇s medium for 24 hours,...The retina of Wistar rats within 1-3 days of birth were dissociated into a retinal ceil suspension using 0.05% trypsin digestion. The cell suspension was incubated in Dulbecco＇s modified Eagle＇s medium for 24 hours, followed by neurobasal medium for 5-7 days. Nissl staining showed that 79.86% of primary cultured retinal cells were positive and immunocytochemical staining showed that the purity of anti-neurofilament heavy chain antibody-positive cells was 71.53%, indicating that the primary culture system of rat retinal neurons was a reliable and stable cell system with neurons as the predominant cell type. The primary cultured retinal neurons were further treated with 0, 5.5, 15, 25, and 35 mM glucose for 24, 48, and 72 hours. The thiazolyl blue tetrazolium bromide test and flow cytometry showed that with increasing glucose concentration and treatment duration, the viability of retinal neurons was reduced, and apoptosis increased. In particular, 35 mM glucose exhibited the most significant effect at 72 hours. Thus, rat retinal neurons treated with 35 mM glucose for 72 hours can be used to simulate a neuronal model of diabetic retinopathy.展开更多
Pigment intensity and patterns are important factors that determine the nutritional and market values of tomato fruits.The acropetal manner of light-dependent anthocyanin accumulation with the highest levels at the st...Pigment intensity and patterns are important factors that determine the nutritional and market values of tomato fruits.The acropetal manner of light-dependent anthocyanin accumulation with the highest levels at the stem end of the fruit makes Pro35S:BrTT8 tomato plants an ideal system for investigating the effects of light intensity on anthocyanin biosynthesis.Extensive transcript analyses indicate that anthocyanin pigmentation in Pro35S:BrTT8 plants under high light might be coordinately regulated by the exogenous protein BrTT8 and endogenous proteins SlAN2 and SlMYBL2.Furthermore,yeast two-hybrid assays showed that BrTT8 could interact efficiently with SlAN2,SlMYBL2,and SlAN11.Moreover,the physical interaction between BrTT8 and SlAN2 was validated by FRET.Simultaneous overexpression of SlAN2 and BrTT8 activated significant anthocyanin biosynthesis in infiltrated tobacco leaves.In addition,the ability of SlMYBL2 to suppress anthocyanin accumulation was also demonstrated in infiltrated tobacco leaves.Altogether,these results prove that tissue-specific assemblage of the heterogeneous MYB-bHLH-WD40 complex consisting of SlAN2,BrTT8 and SlAN11 triggers nonuniform anthocyanin accumulation in tomato fruit under high light.Additionally,it is proposed that a negative-feedback loop fulfilled by SlMYBL2 also participates in the regulation of anthocyanin production.展开更多
This paper focuses on aeroelastic prediction and analysis for a transonic fan rotor with only its“hot”(running)blade shape available,which is often the case in practical engineering such as in the design stage.Based...This paper focuses on aeroelastic prediction and analysis for a transonic fan rotor with only its“hot”(running)blade shape available,which is often the case in practical engineering such as in the design stage.Based on an in-house and well-validated CFD solver and a hybrid structural finite element modeling/modal approach,three main aspects are considered with special emphasis on dealing with the“hot”blade shape.First,static aeroelastic analysis is presented for shape transformation between“cold”(manufacturing)and“hot”blades,and influence of the dynamic variation of“hot”shape on evaluated aerodynamic performance is investigated.Second,implementation of the energy method for flutter prediction is given and both a regularly used fixed“hot”shape and a variable“hot”shape are considered.Through comparison,influence of the dynamic variation of“hot”shape on evaluated aeroelastic stability is also investigated.Third,another common way to predict flutter,time-domain method,is used for the same concerned case,from which the predicted flutter characteristics are compared with those from the energy method.A well-publicized axial-flow transonic fan rotor,Rotor 67,is selected as a typical example,and the corresponding numerical results and discussions are presented in detail.展开更多
This paper presents a review of the various methods for the stationary non-Gaussian random vibration control.Random vibration tests can be divided,according to the number of exciters,in single-shaker tests and multipl...This paper presents a review of the various methods for the stationary non-Gaussian random vibration control.Random vibration tests can be divided,according to the number of exciters,in single-shaker tests and multiple-shaker tests.In the stationary non-Gaussian random vibration test,the time and frequency domain characteristics of the responses should be controlled independently and simultaneously.Skewness and kurtosis are usually selected as the nonGaussian time control references(targets)while power spectral density is the frequency domain control procedure before it recalls the concepts of non-Gaussianity.Then,the generation of a one frame stationary non-Gaussian random signal for both the single and multiple shakers are reviewed.The commonly used methods for the single non-Gaussian random signal generation in the random vibration test are memoryless nonlinear transformation,phase modification and Filtered Poisson process.For the multiple-shaker case,the sequential phase modification and memoryless nonlinear transformation are used to generate one frame coupled multi-channel non-Gaussian random signal.In order to obtain a stationary and consecutive dynamic input,the time domain randomization procedure is introduced with high computational efficiency and its influences on the skewness and kurtosis are analyzed.Finally,two existing problems in the non-Gaussian random vibration control are addressed.展开更多
Background:Larch(Larix Mill.)forests are widely distributed in the upper parts of mountainous areas in China,playing vital roles in constructing mountain landscapes and maintaining mountain environments.Despite their ...Background:Larch(Larix Mill.)forests are widely distributed in the upper parts of mountainous areas in China,playing vital roles in constructing mountain landscapes and maintaining mountain environments.Despite their importance,our knowledges on the large-scale patterns of structure characteristics and the relationships between different structure variables are unclear.In this paper,we investigated 155 plots from 11 natural larch forest types across the country to explore the biogeographic patterns of the structure characteristics and the allometric relationships between different structure variables for Chinese larch forests.Results:The structure characteristics were significantly different among larch forest types.For different larch forest types,the power function fits the relationships between tree height and diameter at breast height(DBH),average DBH and stem density,and taper and stem density well,but with different exponents among larch forest types.The power exponents of the allometric relationships between tree height and DBH for different larch forest types varied from 0.61 to 0.93(mean=0.86)by standard major axis regression(SMA),and from 0.51 to 0.78(mean=0.56)by ordinary least square regression(OLS).The 50%,75%and 95%quantile regression(QR)and OLS indicated that the average DBH and taper of the L.gmelinii forests,L.gmelinii var.principis-rupprechtii forests,and L.sibirica forests were significantly correlated with stem density.Conclusions:The relationship between tree height and DBH showed a power function relationship for all larch forest types in China,but with different exponents.Overall,stem density was negatively correlated with average DBH and taper.The Sect.Larix forests exhibited stand density effect.Our findings provide an important basis for recognizing the biogeographic patterns of structure factors and for the management of larch forests in China.展开更多
The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape.There are 31 OFP members in the tomato genome.However,their roles in tomato growth and reproductive development are largel...The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape.There are 31 OFP members in the tomato genome.However,their roles in tomato growth and reproductive development are largely unknown.Here,we cloned the OFP transcription factor SlOFP20.Tomato plants overexpressing SlOFP20 displayed several phenotypic defects,including an altered floral architecture and fruit shape and reduced male fertility.SlOFP20 overexpression altered the expression levels of some brassinosteroid(BR)-associated genes,implying that SlOFP20 may play a negative role in the BR response,similar to its ortholog OsOFP19 in rice.Moreover,the transcript accumulation of gibberellin(GA)-related genes was significantly affected in the transgenic lines.SlOFP20 may play an important role in the crosstalk between BR and GA.The pollen germination assay suggested that the pollen germination rate of SlOFP20-OE plants was distinctly lower than that of WT plants.In addition,the tomato pollen-associated genes SlCRK1,SlPMEI,LePRK3,SlPRALF,and LAT52 were all suppressed in the transgenic lines.Our data imply that SlOFP20 may affect floral organ and pollen development by modulating BR and GA signaling in tomato.展开更多
Differentiation of human bone marrow-derived mesenchymal stem cells(hMSCs)is regulated by a variety of cues of their surrounding microenvironments.In particular,mechanical properties of cell culture matrices have been...Differentiation of human bone marrow-derived mesenchymal stem cells(hMSCs)is regulated by a variety of cues of their surrounding microenvironments.In particular,mechanical properties of cell culture matrices have been recently disclosed to play a pivotal role in stem cell differentiation.However,it remains elusive how viscosity affects the chondrogenic differentiation of hMSCs during three-dimensional(3 D)culture.In this study,a 3 D culture system that was established by embedding viscous gelatin solution in chemically cross-linked gelatin hydrogels was used for 3 D culture of hMSCs in gelatin solutions with different viscosities.The influence of solution viscosity on chondrogenic differentiation of hMSCs was investigated.Viscous gelatin solutions promoted cell proliferation in the order of low,middle and high viscosity while elastic hydrogels restricted cell proliferation.High viscosity gelatin solution led to increased production of the cartilaginous matrix.Under the synergistic stimulation of chondrogenic induction factors,high viscosity was beneficial for the chondrogenic differentiation of hMSCs.The results suggested the role of viscosity should be considered as one of the dominant mechanical cues affecting stem cell differentiation.展开更多
The use of clean electricity to replace fossil energy burning for heating is an important emission reduction way to achieve carbon neutrality.Without a good business model,it is very difficult to promote electric heat...The use of clean electricity to replace fossil energy burning for heating is an important emission reduction way to achieve carbon neutrality.Without a good business model,it is very difficult to promote electric heating as a replacement for coal-fired systems in some areas with abundant coal resources.This study proposed a new business model for electric heating with stakeholders that included the government,the power grid company,and heat users.Based on this model,a specific tri-objective optimization model was proposed with the electric heating promotion power,heating electricity price,and government subsidy as variables to characterize the game relationship of the stakeholders,and the components of the stakeholder benefit function were analyzed in detail.A classical multi-objective genetic algorithm was used to solve the model.Finally,an"electrical heating"project for a typical area in China was analyzed,and four promotion cases were examined.The results showed that the power grid company and users had an antagonistic relationship in relation to the electricity price,but the best solution was found for all three stakeholders due to the high financial subsidies provided by the government.展开更多
Homeodomain-leucine zipper(HD-Zip)transcription factors are only present in higher plants and are involved in plant development and stress responses.However,our understanding of their participation in the fruit ripeni...Homeodomain-leucine zipper(HD-Zip)transcription factors are only present in higher plants and are involved in plant development and stress responses.However,our understanding of their participation in the fruit ripening of economical plants,such as tomato(Solanum lycopersicum),remains largely unclear.Here,we report that VAHOX1,a member of the tomato HD-Zip I subfamily,was expressed in all tissues,was highly expressed in breaker+4 fruits,and could be induced by ethylene.RNAi repression of VAHOX1(VAHOX1-RNAi)resulted in accelerated fruit ripening,enhanced sensitivity to ethylene,and increased total carotenoid content and ethylene production.Conversely,VAHOX1 overexpression(VAHOX1-OE)in tomato had the opposite effect.RNA-Seq results showed that altering VAHOX1 expression affected the transcript accumulation of a series of genes involved in ethylene biosynthesis and signal transduction and cell wall modification.Additionally,a dual-luciferase reporter assay,histochemical analysis of GUS activity and a yeast one-hybrid(Y1H)assay revealed that VAHOX1 could activate the expression of AP2a.Our findings may expand our knowledge about the physiological functions of HD-Zip transcription factors in tomato and highlight the diversities of transcriptional regulation during the fruit ripening process.展开更多
Acute limb ischemia is a urgent condition which occurs when there is an abrupt interruption of blood flow into an extremity usually because of either embolic or thrombotic vascular occlusion. Restoration of perfusion ...Acute limb ischemia is a urgent condition which occurs when there is an abrupt interruption of blood flow into an extremity usually because of either embolic or thrombotic vascular occlusion. Restoration of perfusion through early intervention can decrease amputation and mortality. Contemporary treatment includes both surgery and endovascular techniques. There is a rapid progress in endovascular intervention therapy. This article aims to make a comprehensive review of the endovascular intervention options of acute limb ischemia.展开更多
The principles and methods of regional land consolidation in Yunnan Province are expounded. On the basis of differences in topography, climate, soil, hydrology and other natural conditions and the characteristics of s...The principles and methods of regional land consolidation in Yunnan Province are expounded. On the basis of differences in topography, climate, soil, hydrology and other natural conditions and the characteristics of spatial layout of land use, agricultural zoning, cropping system and land consolidation measures, the land consolidation zoning indicator system composed of five indicators covering ecological environment, socio-economy, land use, land consolidation and land quality is established by using the GIS spatial analysis and mathematical analysis. Against this backdrop, the Yunnan Province is divided into five first-level land consolidation zones, including the middle-mountain lake basin plateau consolidation zone in central Yunnan, the middle and low mountain wide valley basin consolidation zone in southwest Yunnan, the karst middle and low mountains consolidation zone in southeast Yunnan, the high-mountain and highlands consolidation zone in northeast Yunnan, the middle -mountain and mountain plateau consolidation zone in northeast Yunnan.展开更多
Interactions between the light-harvesting subunits and the non-covalently bound photopigments attribute considerably to the spectral properties of photosynthetic bacteria light-harvesting complexes. In our previous st...Interactions between the light-harvesting subunits and the non-covalently bound photopigments attribute considerably to the spectral properties of photosynthetic bacteria light-harvesting complexes. In our previous studies, we have constructed a novel Rhodobacter sphaeroides expression system. In the present study, we focus on the spectral properties of LH2 when heterologously express LH2 with β-subunit- GFP fusion protein in Rb. sphaeroides. Near infra-red spectrum of LH2 remained nearly unchanged as measured by spectroscopy. Fluorescence spectrum suggested that the LH2 with β-subunit-GFP fusion protein complexes still possessed normal activity in energy transfer. However, photopigments contents were significantly decreased to a very low level in the LH2 with β-subunit-GFP fusion protein complexes compared to that of LH2. FT-IR spectra indicated that interactions between photopigments and LH2 α/β- subunits appeared not to be changed. It was concluded that the LH2 spectral properties exhibited very similar even when heterologously expressed LH2 b-subunit fusion protein in Rb. sphaeroides. Our present study may supply a new insight into better understand the interactions between light-harvesting subunits and photopigments and bacterial photosynthesis and promote the development of the novel Rb. sphaeroides expression system.展开更多
Quality is the life of architecture.Without quality there is nothing.Engineering projects have the characteristics of large investment and long construction period,so the quality of construction projects must be stric...Quality is the life of architecture.Without quality there is nothing.Engineering projects have the characteristics of large investment and long construction period,so the quality of construction projects must be strictly controlled.The control of construction quality of engineering projects is the quality control of the whole process and the participation of all employees.It is the implementation of construction engineering quality regulations and mandatory standards,the correct configuration of construction production management elements and the use of scientific management methods to achieve the expected use function of engineering projects And quality standards,deliver the owner a satisfactory quality project.Most of the quality problems of construction projects appear in the construction stage.Therefore,we must strictly control the quality in project construction,strengthen the whole process management from the organization and management,find a project quality management system suitable for China’s national conditions,and be able to eliminate the hidden quality hazards in the project in time to ensure the project The construction project can meet the target requirements,and the project quality can be effectively controlled.This article mainly analyzes the current problems affecting the construction quality,combined with the actual analysis,and then find some countermeasures to solve the problem.展开更多
Soil is the largest carbon(C)reservoir in terrestrial ecosystems and plays a crucial role in regulating the global C cycle and climate change.Increasing nitrogen(N)deposition has been widely considered as a critical f...Soil is the largest carbon(C)reservoir in terrestrial ecosystems and plays a crucial role in regulating the global C cycle and climate change.Increasing nitrogen(N)deposition has been widely considered as a critical factor affecting soil organic carbon(SOC)storage,but its effect on SOC components with different stability remains unclear.Here,we analyzed extensive empirical data from 304 sites worldwide to investigate how SOC and its components respond to N addition.Our analysis showed that N addition led to a significant increase in bulk SOC(6.7%),with greater increases in croplands(10.6%)and forests(6.0%)compared to grasslands(2.1%).Regarding SOC components,N addition promoted the accumulation of plant-derived C(9.7%–28.5%)over microbial-derived C(0.2%),as well as labile(5.7%)over recalcitrant components(–1.2%),resulting in a shift towards increased accumulation of plant-derived labile C.Consistently,N addition led to a greater increase in particulate organic C(11.9%)than mineral-associated organic C(3.6%),suggesting that N addition promotes C accumulation across all pools,with more increase in unstable than stable pools.The responses of SOC and its components were best predicted by the N addition rate and net primary productivity.Overall,our findings suggest that N enrichment could promote the accumulation of plant-derived and non-mineral associated C and a subsequent decrease in the overall stability of soil C pool,which underscores the importance of considering the effects of N enrichment on SOC components for a better understanding of C dynamics in soils.展开更多
Combining hyperthermia and chemotherapy for maximum anticancer efficacy remains a challenge because drugtolerant cancer cells often evade this synergistic treatment due to drug resistance and asynchronous drug release...Combining hyperthermia and chemotherapy for maximum anticancer efficacy remains a challenge because drugtolerant cancer cells often evade this synergistic treatment due to drug resistance and asynchronous drug release.In this study,multifunctional scaffolds were designed to efficiently treat drug-tolerant breast cancer by improving the sensitization of breast cancer cells and synchronizing anticancer drug release with magnetic hyperthermia.The scaffolds contained microRNA-encapsulated matrix metalloproteinase-cleavable liposomes,doxorubicin-encapsulated thermoresponsive liposomes and Fe_(3)O_(4)nanoparticles.The scaffolds could release microRNA specifically to improve the sensitization of breast cancer cells to anticancer drugs.The scaffolds also showed excellent hyperthermia effects under alternating magnetic field irradiation.Moreover,doxorubicin release was synchronized with magnetic hyperthermia.In vitro and in vivo studies demonstrated that the scaffolds effectively reduced drug resistance and eliminated doxorubicin-tolerant MDA-MB-231 cells through the syner-gistic effect of magnetic hyperthermia and sensitizing chemotherapy.Additionally,the scaffolds could support the proliferation and adipogenic differentiation of stem cells for adipose tissue regeneration after killing cancer cells at a late therapeutic stage.These composite scaffolds offer an innovative strategy for treating breast cancer,with synergistic anticancer effects and regenerative functions.展开更多
Immunohistochemistry(IHC)is a vital technique for detecting specific proteins and antigens in tissue sections using antibodies,aiding in the analysis of tumor growth and metastasis.However,IHC is costly and time-consu...Immunohistochemistry(IHC)is a vital technique for detecting specific proteins and antigens in tissue sections using antibodies,aiding in the analysis of tumor growth and metastasis.However,IHC is costly and time-consuming,making it challenging to implement on a large scale.To address this issue,we introduce a method that enables virtual IHC staining directly on Hematoxylin and Eosin(H&E)images.Firstly,we have developed a novel registration technique,called Bi-stage Registration based on density Clustering(BiReC),to enhance the registration efficiency between H&E and IHC images.This method involves automatically generating numerous Regions Of Interest(ROI)labels on the H&E image for model training,with the labels being determined by the intensity of IHC staining.Secondly,we propose a novel two-branch network architecture,called SeaConvNeXt,which integrates a lightweight Squeeze-Enhanced Axial(SEA)attention mechanism to efficiently extract and fuse multi-level local and global features from H&E images for direct prediction of specific proteins and antigens.The SeaConvNeXt consists of a ConvNeXt branch and a global fusion branch.The ConvNeXt branch extracts multi-level local features at four stages,while the global fusion branch,including an SEA Transformer module and three global blocks,is designed for global feature extraction and multiple feature fusion.Our experiments demonstrate that SeaConvNeXt outperforms current state-of-the-art methods on two public datasets with corresponding IHC and H&E images,achieving an AUC of 90.7%on the HER2SC dataset and 82.5%on the CRC dataset.These results suggest that SeaConvNeXt has great potential for predicting virtual IHC staining on H&E images.展开更多
Strong DC coupling with weak AC and large-scale renewable energy integration are the two significant characteristics of ultra-high-voltage AC/DC(UHVAC/DC)hybrid power grids in China.Strong coupling between AC and DC g...Strong DC coupling with weak AC and large-scale renewable energy integration are the two significant characteristics of ultra-high-voltage AC/DC(UHVAC/DC)hybrid power grids in China.Strong coupling between AC and DC grids and the different integration performance of renewable energy sources have profoundly changed the stability characteristics of the power system.The traditional stability control system is inadequate for the stability control of UHVAC/DC power grids.This paper analyzes the requirements for constructing an integrated defense system in a UHVAC/DC hybrid power grid(i.e.power system protection).The definition,connotation,and designing principles of power system protection are put forward.The relationship between the power system protection and the traditional three-defense lines is investigated.The design principles,general hardware structure and main functions of a power system protection are presented.Key problems and technologies are specified in the construction of the power system protection.展开更多
Extracellular matrix （ECM） plays a very important role in regulating cell function and fate. It is highly desirable to fabricate biomimetic models to investigate the role of ECM in stem cell differentiation. In this...Extracellular matrix （ECM） plays a very important role in regulating cell function and fate. It is highly desirable to fabricate biomimetic models to investigate the role of ECM in stem cell differentiation. In this study, arginine- glycine--aspartate （RGD）-modified gold nanoparticles （Au NPs） with tunable surface ligand density were prepared to mimic the ECM microenvironment. Their effect on osteogenic and adipogenic differentiation of human mesenchymal stem cells （MSCs） was investigated. The biomimetic Au NPs were taken up by MSCs in a ligand density-dependent manner. The biomimetic NPs with a high RGD density had an inhibitive effect on the alkaline phosphatase （ALP） activity, calcium deposition, and osteogenic marker gene expression of MSCs. Their effect on oil droplet formation and adipogenic marker gene expression was negative when RGD density was low, while their effect was promotive when RGD density was high. The biomimetic Au NPs regulated the osteogenic and adipogenic differentiation of MSCs mainly through affecting the focal adhesion and cytoskeleton. This study highlights the roles of biomimetic NPs on stem cell differentiation that could provide a meaningful strategy in fabricating functional biomaterials for tissue engineering and biomedical applications.展开更多
Aims Alien plant invasion has become a major global environmental issue,causing severe economic and ecological damages.Severe invasions have been reported in some regions of China.However,most studies have been conduc...Aims Alien plant invasion has become a major global environmental issue,causing severe economic and ecological damages.Severe invasions have been reported in some regions of China.However,most studies have been conducted at local and provincial levels,and the overall degree of invasion in natural forests across China remains unclear.Here,we explored the biogeographic patterns and their environmental and socioeconomic controls of the invaded alien woody plants in natural forests across the country.Methods We compiled the data of 3573 natural forest plots across the China's Mainland and mapped spatial distribution of alien woody plant invasion.We also used logistic regression models to identify the key socioeconomic and environmental factors that were associated with the observed invasion patterns.Important Findings We found that only 271 plots among 3573 natural forest plots were invaded by alien woody plants,accounting for 7.58%of all plots.Among all 2825 woody plant species across all plots surveyed,only 5 alien species(0.177%)were found.Both human activities and climate factors were related to the observed invasion patterns.Since China’s natural forests are mostly located in remote mountainous areas with limited human disturbance,alien woody plant invasions are less than those reported in North America and Europe.However,with the development of transportation and increased economic activities in mountainous areas,more invasions by alien plants may be expected in the future.Therefore,proactive management and policy making are desired to prevent or slow down the invasion processes.展开更多
Deciduous oak forest is one of the typical vegetation types in temperate and subtropical mountain zones in China.However,the patterns and determinants of the structural characteristics of these forests remain poorly u...Deciduous oak forest is one of the typical vegetation types in temperate and subtropical mountain zones in China.However,the patterns and determinants of the structural characteristics of these forests remain poorly understood.We investigated 682 oak forest plots across China to characterize the community structures of the oak forests and analyze the underlying factors controlling their spatial patterns.Across all plots,the overall mean values were 13.7 cm,10.0 m,1468 stems/ha and 24.3 m^(2)/ha for the diameter at breast height(DBH),height,stem density and total basal area(TBA)of trees,respectively.The average species richness was 6 species/600 m^(2),10 species/100 m^(2) and 4 species/1 m^(2) for the tree,shrub and herb layers,respectively.As latitude increased,the mean tree height,stem density,TBA,tree species richness and shrub species richness decreased,and the mean DBH did not show a significant trend,while species richness of herbs increased significantly.Climatic and anthropogenic variables could explain more variations in mean DBH,mean tree height,TBA,tree species richness,shrub species richness than those in stem density and herb species richness.Further analysis showed that precipitation-related climatic factors were major factors shaping the spatial patterns of community structures.Our findings provide a basis for recognizing the biogeographic patterns of oak forest structures and their responses to global change in China.展开更多
基金supported by the Department of Health of Hunan Province, No. B2009-050the Science and Technology Foundation of Hunan Province, No.2012FJ4077
文摘The retina of Wistar rats within 1-3 days of birth were dissociated into a retinal ceil suspension using 0.05% trypsin digestion. The cell suspension was incubated in Dulbecco＇s modified Eagle＇s medium for 24 hours, followed by neurobasal medium for 5-7 days. Nissl staining showed that 79.86% of primary cultured retinal cells were positive and immunocytochemical staining showed that the purity of anti-neurofilament heavy chain antibody-positive cells was 71.53%, indicating that the primary culture system of rat retinal neurons was a reliable and stable cell system with neurons as the predominant cell type. The primary cultured retinal neurons were further treated with 0, 5.5, 15, 25, and 35 mM glucose for 24, 48, and 72 hours. The thiazolyl blue tetrazolium bromide test and flow cytometry showed that with increasing glucose concentration and treatment duration, the viability of retinal neurons was reduced, and apoptosis increased. In particular, 35 mM glucose exhibited the most significant effect at 72 hours. Thus, rat retinal neurons treated with 35 mM glucose for 72 hours can be used to simulate a neuronal model of diabetic retinopathy.
基金supported by the National Natural Science Foundation of China(nos.31601760,31301778)the Industry−University−Research Collaboration Grants of Henan Province(172107000020).
文摘Pigment intensity and patterns are important factors that determine the nutritional and market values of tomato fruits.The acropetal manner of light-dependent anthocyanin accumulation with the highest levels at the stem end of the fruit makes Pro35S:BrTT8 tomato plants an ideal system for investigating the effects of light intensity on anthocyanin biosynthesis.Extensive transcript analyses indicate that anthocyanin pigmentation in Pro35S:BrTT8 plants under high light might be coordinately regulated by the exogenous protein BrTT8 and endogenous proteins SlAN2 and SlMYBL2.Furthermore,yeast two-hybrid assays showed that BrTT8 could interact efficiently with SlAN2,SlMYBL2,and SlAN11.Moreover,the physical interaction between BrTT8 and SlAN2 was validated by FRET.Simultaneous overexpression of SlAN2 and BrTT8 activated significant anthocyanin biosynthesis in infiltrated tobacco leaves.In addition,the ability of SlMYBL2 to suppress anthocyanin accumulation was also demonstrated in infiltrated tobacco leaves.Altogether,these results prove that tissue-specific assemblage of the heterogeneous MYB-bHLH-WD40 complex consisting of SlAN2,BrTT8 and SlAN11 triggers nonuniform anthocyanin accumulation in tomato fruit under high light.Additionally,it is proposed that a negative-feedback loop fulfilled by SlMYBL2 also participates in the regulation of anthocyanin production.
基金This study was supported by National Natural Science Foundation of China(No.11872212),China Postdoctoral Science Foundation Grant(No.2019M650112),Natural Science Foundation of Jiangsu Province,China(No.BK20190386)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘This paper focuses on aeroelastic prediction and analysis for a transonic fan rotor with only its“hot”(running)blade shape available,which is often the case in practical engineering such as in the design stage.Based on an in-house and well-validated CFD solver and a hybrid structural finite element modeling/modal approach,three main aspects are considered with special emphasis on dealing with the“hot”blade shape.First,static aeroelastic analysis is presented for shape transformation between“cold”(manufacturing)and“hot”blades,and influence of the dynamic variation of“hot”shape on evaluated aerodynamic performance is investigated.Second,implementation of the energy method for flutter prediction is given and both a regularly used fixed“hot”shape and a variable“hot”shape are considered.Through comparison,influence of the dynamic variation of“hot”shape on evaluated aeroelastic stability is also investigated.Third,another common way to predict flutter,time-domain method,is used for the same concerned case,from which the predicted flutter characteristics are compared with those from the energy method.A well-publicized axial-flow transonic fan rotor,Rotor 67,is selected as a typical example,and the corresponding numerical results and discussions are presented in detail.
基金co-supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,china。
文摘This paper presents a review of the various methods for the stationary non-Gaussian random vibration control.Random vibration tests can be divided,according to the number of exciters,in single-shaker tests and multiple-shaker tests.In the stationary non-Gaussian random vibration test,the time and frequency domain characteristics of the responses should be controlled independently and simultaneously.Skewness and kurtosis are usually selected as the nonGaussian time control references(targets)while power spectral density is the frequency domain control procedure before it recalls the concepts of non-Gaussianity.Then,the generation of a one frame stationary non-Gaussian random signal for both the single and multiple shakers are reviewed.The commonly used methods for the single non-Gaussian random signal generation in the random vibration test are memoryless nonlinear transformation,phase modification and Filtered Poisson process.For the multiple-shaker case,the sequential phase modification and memoryless nonlinear transformation are used to generate one frame coupled multi-channel non-Gaussian random signal.In order to obtain a stationary and consecutive dynamic input,the time domain randomization procedure is introduced with high computational efficiency and its influences on the skewness and kurtosis are analyzed.Finally,two existing problems in the non-Gaussian random vibration control are addressed.
基金the National Science and Technology Basic Project of China(No.2015FY210200)National Natural Science Foundation(No.31988102).
文摘Background:Larch(Larix Mill.)forests are widely distributed in the upper parts of mountainous areas in China,playing vital roles in constructing mountain landscapes and maintaining mountain environments.Despite their importance,our knowledges on the large-scale patterns of structure characteristics and the relationships between different structure variables are unclear.In this paper,we investigated 155 plots from 11 natural larch forest types across the country to explore the biogeographic patterns of the structure characteristics and the allometric relationships between different structure variables for Chinese larch forests.Results:The structure characteristics were significantly different among larch forest types.For different larch forest types,the power function fits the relationships between tree height and diameter at breast height(DBH),average DBH and stem density,and taper and stem density well,but with different exponents among larch forest types.The power exponents of the allometric relationships between tree height and DBH for different larch forest types varied from 0.61 to 0.93(mean=0.86)by standard major axis regression(SMA),and from 0.51 to 0.78(mean=0.56)by ordinary least square regression(OLS).The 50%,75%and 95%quantile regression(QR)and OLS indicated that the average DBH and taper of the L.gmelinii forests,L.gmelinii var.principis-rupprechtii forests,and L.sibirica forests were significantly correlated with stem density.Conclusions:The relationship between tree height and DBH showed a power function relationship for all larch forest types in China,but with different exponents.Overall,stem density was negatively correlated with average DBH and taper.The Sect.Larix forests exhibited stand density effect.Our findings provide an important basis for recognizing the biogeographic patterns of structure factors and for the management of larch forests in China.
基金supported by the National Natural Science Foundation of China(no.31572129)the Technology System of National Bulk Vegetable Industry-Eggplant Breeding Position(CARS-25-A-06).
文摘The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape.There are 31 OFP members in the tomato genome.However,their roles in tomato growth and reproductive development are largely unknown.Here,we cloned the OFP transcription factor SlOFP20.Tomato plants overexpressing SlOFP20 displayed several phenotypic defects,including an altered floral architecture and fruit shape and reduced male fertility.SlOFP20 overexpression altered the expression levels of some brassinosteroid(BR)-associated genes,implying that SlOFP20 may play a negative role in the BR response,similar to its ortholog OsOFP19 in rice.Moreover,the transcript accumulation of gibberellin(GA)-related genes was significantly affected in the transgenic lines.SlOFP20 may play an important role in the crosstalk between BR and GA.The pollen germination assay suggested that the pollen germination rate of SlOFP20-OE plants was distinctly lower than that of WT plants.In addition,the tomato pollen-associated genes SlCRK1,SlPMEI,LePRK3,SlPRALF,and LAT52 were all suppressed in the transgenic lines.Our data imply that SlOFP20 may affect floral organ and pollen development by modulating BR and GA signaling in tomato.
基金financially supported by JSPS KAKENHI(Nos.18K19947,18K19945 and 19H04475)。
文摘Differentiation of human bone marrow-derived mesenchymal stem cells(hMSCs)is regulated by a variety of cues of their surrounding microenvironments.In particular,mechanical properties of cell culture matrices have been recently disclosed to play a pivotal role in stem cell differentiation.However,it remains elusive how viscosity affects the chondrogenic differentiation of hMSCs during three-dimensional(3 D)culture.In this study,a 3 D culture system that was established by embedding viscous gelatin solution in chemically cross-linked gelatin hydrogels was used for 3 D culture of hMSCs in gelatin solutions with different viscosities.The influence of solution viscosity on chondrogenic differentiation of hMSCs was investigated.Viscous gelatin solutions promoted cell proliferation in the order of low,middle and high viscosity while elastic hydrogels restricted cell proliferation.High viscosity gelatin solution led to increased production of the cartilaginous matrix.Under the synergistic stimulation of chondrogenic induction factors,high viscosity was beneficial for the chondrogenic differentiation of hMSCs.The results suggested the role of viscosity should be considered as one of the dominant mechanical cues affecting stem cell differentiation.
基金supported by Central Universities Basic Scientific Research Business Project of Ministry of Education(Talent Special Project,DUT20RC(5)021)State Grid Science and Technology Project of China(SGXJCJ00YJJS1800384)。
文摘The use of clean electricity to replace fossil energy burning for heating is an important emission reduction way to achieve carbon neutrality.Without a good business model,it is very difficult to promote electric heating as a replacement for coal-fired systems in some areas with abundant coal resources.This study proposed a new business model for electric heating with stakeholders that included the government,the power grid company,and heat users.Based on this model,a specific tri-objective optimization model was proposed with the electric heating promotion power,heating electricity price,and government subsidy as variables to characterize the game relationship of the stakeholders,and the components of the stakeholder benefit function were analyzed in detail.A classical multi-objective genetic algorithm was used to solve the model.Finally,an"electrical heating"project for a typical area in China was analyzed,and four promotion cases were examined.The results showed that the power grid company and users had an antagonistic relationship in relation to the electricity price,but the best solution was found for all three stakeholders due to the high financial subsidies provided by the government.
基金The project was supported by the National Natural Science Foun-dation of China(no.31872121)the Natural Science Founda-tion of Chongqing,China(csts2019jcyj-msxmX0094,cstc2019jcyj-msxmX0361).
文摘Homeodomain-leucine zipper(HD-Zip)transcription factors are only present in higher plants and are involved in plant development and stress responses.However,our understanding of their participation in the fruit ripening of economical plants,such as tomato(Solanum lycopersicum),remains largely unclear.Here,we report that VAHOX1,a member of the tomato HD-Zip I subfamily,was expressed in all tissues,was highly expressed in breaker+4 fruits,and could be induced by ethylene.RNAi repression of VAHOX1(VAHOX1-RNAi)resulted in accelerated fruit ripening,enhanced sensitivity to ethylene,and increased total carotenoid content and ethylene production.Conversely,VAHOX1 overexpression(VAHOX1-OE)in tomato had the opposite effect.RNA-Seq results showed that altering VAHOX1 expression affected the transcript accumulation of a series of genes involved in ethylene biosynthesis and signal transduction and cell wall modification.Additionally,a dual-luciferase reporter assay,histochemical analysis of GUS activity and a yeast one-hybrid(Y1H)assay revealed that VAHOX1 could activate the expression of AP2a.Our findings may expand our knowledge about the physiological functions of HD-Zip transcription factors in tomato and highlight the diversities of transcriptional regulation during the fruit ripening process.
文摘Acute limb ischemia is a urgent condition which occurs when there is an abrupt interruption of blood flow into an extremity usually because of either embolic or thrombotic vascular occlusion. Restoration of perfusion through early intervention can decrease amputation and mortality. Contemporary treatment includes both surgery and endovascular techniques. There is a rapid progress in endovascular intervention therapy. This article aims to make a comprehensive review of the endovascular intervention options of acute limb ischemia.
基金Supported by Multi-scale Object-oriented Land Use of Space Coupling Mechanism Research of National Natural Science Foundation
文摘The principles and methods of regional land consolidation in Yunnan Province are expounded. On the basis of differences in topography, climate, soil, hydrology and other natural conditions and the characteristics of spatial layout of land use, agricultural zoning, cropping system and land consolidation measures, the land consolidation zoning indicator system composed of five indicators covering ecological environment, socio-economy, land use, land consolidation and land quality is established by using the GIS spatial analysis and mathematical analysis. Against this backdrop, the Yunnan Province is divided into five first-level land consolidation zones, including the middle-mountain lake basin plateau consolidation zone in central Yunnan, the middle and low mountain wide valley basin consolidation zone in southwest Yunnan, the karst middle and low mountains consolidation zone in southeast Yunnan, the high-mountain and highlands consolidation zone in northeast Yunnan, the middle -mountain and mountain plateau consolidation zone in northeast Yunnan.
文摘Interactions between the light-harvesting subunits and the non-covalently bound photopigments attribute considerably to the spectral properties of photosynthetic bacteria light-harvesting complexes. In our previous studies, we have constructed a novel Rhodobacter sphaeroides expression system. In the present study, we focus on the spectral properties of LH2 when heterologously express LH2 with β-subunit- GFP fusion protein in Rb. sphaeroides. Near infra-red spectrum of LH2 remained nearly unchanged as measured by spectroscopy. Fluorescence spectrum suggested that the LH2 with β-subunit-GFP fusion protein complexes still possessed normal activity in energy transfer. However, photopigments contents were significantly decreased to a very low level in the LH2 with β-subunit-GFP fusion protein complexes compared to that of LH2. FT-IR spectra indicated that interactions between photopigments and LH2 α/β- subunits appeared not to be changed. It was concluded that the LH2 spectral properties exhibited very similar even when heterologously expressed LH2 b-subunit fusion protein in Rb. sphaeroides. Our present study may supply a new insight into better understand the interactions between light-harvesting subunits and photopigments and bacterial photosynthesis and promote the development of the novel Rb. sphaeroides expression system.
文摘Quality is the life of architecture.Without quality there is nothing.Engineering projects have the characteristics of large investment and long construction period,so the quality of construction projects must be strictly controlled.The control of construction quality of engineering projects is the quality control of the whole process and the participation of all employees.It is the implementation of construction engineering quality regulations and mandatory standards,the correct configuration of construction production management elements and the use of scientific management methods to achieve the expected use function of engineering projects And quality standards,deliver the owner a satisfactory quality project.Most of the quality problems of construction projects appear in the construction stage.Therefore,we must strictly control the quality in project construction,strengthen the whole process management from the organization and management,find a project quality management system suitable for China’s national conditions,and be able to eliminate the hidden quality hazards in the project in time to ensure the project The construction project can meet the target requirements,and the project quality can be effectively controlled.This article mainly analyzes the current problems affecting the construction quality,combined with the actual analysis,and then find some countermeasures to solve the problem.
基金supported by the National Natural Science Foundation of China(32101331,31988102)the Key Research and Development Program of Yunnan Province(202303AC100009)Talent and Platform Program for Science and Technology(202305AA160014,202405AA350013)。
文摘Soil is the largest carbon(C)reservoir in terrestrial ecosystems and plays a crucial role in regulating the global C cycle and climate change.Increasing nitrogen(N)deposition has been widely considered as a critical factor affecting soil organic carbon(SOC)storage,but its effect on SOC components with different stability remains unclear.Here,we analyzed extensive empirical data from 304 sites worldwide to investigate how SOC and its components respond to N addition.Our analysis showed that N addition led to a significant increase in bulk SOC(6.7%),with greater increases in croplands(10.6%)and forests(6.0%)compared to grasslands(2.1%).Regarding SOC components,N addition promoted the accumulation of plant-derived C(9.7%–28.5%)over microbial-derived C(0.2%),as well as labile(5.7%)over recalcitrant components(–1.2%),resulting in a shift towards increased accumulation of plant-derived labile C.Consistently,N addition led to a greater increase in particulate organic C(11.9%)than mineral-associated organic C(3.6%),suggesting that N addition promotes C accumulation across all pools,with more increase in unstable than stable pools.The responses of SOC and its components were best predicted by the N addition rate and net primary productivity.Overall,our findings suggest that N enrichment could promote the accumulation of plant-derived and non-mineral associated C and a subsequent decrease in the overall stability of soil C pool,which underscores the importance of considering the effects of N enrichment on SOC components for a better understanding of C dynamics in soils.
基金supported by JSPS KAKENHI Grant Number 19H04475,21H03830,22K19926 and 24K03289.
文摘Combining hyperthermia and chemotherapy for maximum anticancer efficacy remains a challenge because drugtolerant cancer cells often evade this synergistic treatment due to drug resistance and asynchronous drug release.In this study,multifunctional scaffolds were designed to efficiently treat drug-tolerant breast cancer by improving the sensitization of breast cancer cells and synchronizing anticancer drug release with magnetic hyperthermia.The scaffolds contained microRNA-encapsulated matrix metalloproteinase-cleavable liposomes,doxorubicin-encapsulated thermoresponsive liposomes and Fe_(3)O_(4)nanoparticles.The scaffolds could release microRNA specifically to improve the sensitization of breast cancer cells to anticancer drugs.The scaffolds also showed excellent hyperthermia effects under alternating magnetic field irradiation.Moreover,doxorubicin release was synchronized with magnetic hyperthermia.In vitro and in vivo studies demonstrated that the scaffolds effectively reduced drug resistance and eliminated doxorubicin-tolerant MDA-MB-231 cells through the syner-gistic effect of magnetic hyperthermia and sensitizing chemotherapy.Additionally,the scaffolds could support the proliferation and adipogenic differentiation of stem cells for adipose tissue regeneration after killing cancer cells at a late therapeutic stage.These composite scaffolds offer an innovative strategy for treating breast cancer,with synergistic anticancer effects and regenerative functions.
基金supported by the National Key R&D Program of China(No.2023YFC3402800)the National Natural Science Foundation of China(Nos.62371276,62272288,and 82272084)the Fundamental Research Funds for the Central Universities,Shaanxi Normal University(No.GK202302006).
文摘Immunohistochemistry(IHC)is a vital technique for detecting specific proteins and antigens in tissue sections using antibodies,aiding in the analysis of tumor growth and metastasis.However,IHC is costly and time-consuming,making it challenging to implement on a large scale.To address this issue,we introduce a method that enables virtual IHC staining directly on Hematoxylin and Eosin(H&E)images.Firstly,we have developed a novel registration technique,called Bi-stage Registration based on density Clustering(BiReC),to enhance the registration efficiency between H&E and IHC images.This method involves automatically generating numerous Regions Of Interest(ROI)labels on the H&E image for model training,with the labels being determined by the intensity of IHC staining.Secondly,we propose a novel two-branch network architecture,called SeaConvNeXt,which integrates a lightweight Squeeze-Enhanced Axial(SEA)attention mechanism to efficiently extract and fuse multi-level local and global features from H&E images for direct prediction of specific proteins and antigens.The SeaConvNeXt consists of a ConvNeXt branch and a global fusion branch.The ConvNeXt branch extracts multi-level local features at four stages,while the global fusion branch,including an SEA Transformer module and three global blocks,is designed for global feature extraction and multiple feature fusion.Our experiments demonstrate that SeaConvNeXt outperforms current state-of-the-art methods on two public datasets with corresponding IHC and H&E images,achieving an AUC of 90.7%on the HER2SC dataset and 82.5%on the CRC dataset.These results suggest that SeaConvNeXt has great potential for predicting virtual IHC staining on H&E images.
文摘Strong DC coupling with weak AC and large-scale renewable energy integration are the two significant characteristics of ultra-high-voltage AC/DC(UHVAC/DC)hybrid power grids in China.Strong coupling between AC and DC grids and the different integration performance of renewable energy sources have profoundly changed the stability characteristics of the power system.The traditional stability control system is inadequate for the stability control of UHVAC/DC power grids.This paper analyzes the requirements for constructing an integrated defense system in a UHVAC/DC hybrid power grid(i.e.power system protection).The definition,connotation,and designing principles of power system protection are put forward.The relationship between the power system protection and the traditional three-defense lines is investigated.The design principles,general hardware structure and main functions of a power system protection are presented.Key problems and technologies are specified in the construction of the power system protection.
文摘Extracellular matrix （ECM） plays a very important role in regulating cell function and fate. It is highly desirable to fabricate biomimetic models to investigate the role of ECM in stem cell differentiation. In this study, arginine- glycine--aspartate （RGD）-modified gold nanoparticles （Au NPs） with tunable surface ligand density were prepared to mimic the ECM microenvironment. Their effect on osteogenic and adipogenic differentiation of human mesenchymal stem cells （MSCs） was investigated. The biomimetic Au NPs were taken up by MSCs in a ligand density-dependent manner. The biomimetic NPs with a high RGD density had an inhibitive effect on the alkaline phosphatase （ALP） activity, calcium deposition, and osteogenic marker gene expression of MSCs. Their effect on oil droplet formation and adipogenic marker gene expression was negative when RGD density was low, while their effect was promotive when RGD density was high. The biomimetic Au NPs regulated the osteogenic and adipogenic differentiation of MSCs mainly through affecting the focal adhesion and cytoskeleton. This study highlights the roles of biomimetic NPs on stem cell differentiation that could provide a meaningful strategy in fabricating functional biomaterials for tissue engineering and biomedical applications.
基金This research was supported by the National Natural Science Foundation of China(31988102).
文摘Aims Alien plant invasion has become a major global environmental issue,causing severe economic and ecological damages.Severe invasions have been reported in some regions of China.However,most studies have been conducted at local and provincial levels,and the overall degree of invasion in natural forests across China remains unclear.Here,we explored the biogeographic patterns and their environmental and socioeconomic controls of the invaded alien woody plants in natural forests across the country.Methods We compiled the data of 3573 natural forest plots across the China's Mainland and mapped spatial distribution of alien woody plant invasion.We also used logistic regression models to identify the key socioeconomic and environmental factors that were associated with the observed invasion patterns.Important Findings We found that only 271 plots among 3573 natural forest plots were invaded by alien woody plants,accounting for 7.58%of all plots.Among all 2825 woody plant species across all plots surveyed,only 5 alien species(0.177%)were found.Both human activities and climate factors were related to the observed invasion patterns.Since China’s natural forests are mostly located in remote mountainous areas with limited human disturbance,alien woody plant invasions are less than those reported in North America and Europe.However,with the development of transportation and increased economic activities in mountainous areas,more invasions by alien plants may be expected in the future.Therefore,proactive management and policy making are desired to prevent or slow down the invasion processes.
基金supported by the National Natural Science Foundation of China(no.31988102)the National Key Research and Development Program of China(no.2017YFC0503906)Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDY-SSW-SMC011).
文摘Deciduous oak forest is one of the typical vegetation types in temperate and subtropical mountain zones in China.However,the patterns and determinants of the structural characteristics of these forests remain poorly understood.We investigated 682 oak forest plots across China to characterize the community structures of the oak forests and analyze the underlying factors controlling their spatial patterns.Across all plots,the overall mean values were 13.7 cm,10.0 m,1468 stems/ha and 24.3 m^(2)/ha for the diameter at breast height(DBH),height,stem density and total basal area(TBA)of trees,respectively.The average species richness was 6 species/600 m^(2),10 species/100 m^(2) and 4 species/1 m^(2) for the tree,shrub and herb layers,respectively.As latitude increased,the mean tree height,stem density,TBA,tree species richness and shrub species richness decreased,and the mean DBH did not show a significant trend,while species richness of herbs increased significantly.Climatic and anthropogenic variables could explain more variations in mean DBH,mean tree height,TBA,tree species richness,shrub species richness than those in stem density and herb species richness.Further analysis showed that precipitation-related climatic factors were major factors shaping the spatial patterns of community structures.Our findings provide a basis for recognizing the biogeographic patterns of oak forest structures and their responses to global change in China.
