With the advent of the era of big data and artificial intelligence, new infrastructure construction(NIC) has attracted the attention of many countries. The development of NIC provides an opportunity to bridge the digi...With the advent of the era of big data and artificial intelligence, new infrastructure construction(NIC) has attracted the attention of many countries. The development of NIC provides an opportunity to bridge the digital divide and narrow the regional gap,providing continuous impetus to further promote economic development. Here, we considered 31 provincial-level administrative units in China(not including Hong Kong, Macao, and Taiwan of China due to data unavailable) and established comprehensive evaluation indicators for the development potential of NIC. Afterward, we used the entropy-weight TOPSIS model to determine the development potential of NIC and analyze its spatio-temporal evolution characteristics. Furthermore, the GeoDetector model was applied to explore the driving mechanism of the NIC development potential. The conclusions were as follows: (1) The Chinese NIC development potential is generally low. The eastern China was the region with the highest development potential year by year, while the development potential in the central China was found to be in an accelerating phase. (2) The evolution of the Chinese NIC development potential’s spatial pattern has been characterized by an inland extension and coastal agglomeration. Moreover, we identified a superior development zone, a rising development zone, an inferior development zone, and a declining development zone. (3) The scope of Chinese NIC development potential agglomeration areas has gradually expanded and its degree has gradually deepened. The range of high-value agglomeration in eastern area gradually expanded and its degree gradually deepened. (4) Investment in innovative talents appears as the core factor affecting the Chinese NIC development potential. Whether acting alone or synergistically with other factors, its promoting effect on Chinese NIC development potential is the strongest.展开更多
Based on an investigation of the meaning of development, the neo-classical economic approach to development, and the post-welfarist theory of development, this paper proposes a conceptual framework for understanding h...Based on an investigation of the meaning of development, the neo-classical economic approach to development, and the post-welfarist theory of development, this paper proposes a conceptual framework for understanding human development potentials, while undertaking empirical analysis using cross-sectional and time series data on human development. Human development is associated with basic necessities for subsistence, the quality of life, and political and civil rights, in addition to income indicators. Our analysis suggests that the concept of human development potentials has two dimensions: the rights of development and limits to human development. Both are largely ignored in the neoclassical theory of development. However, human development is not unbounded, which approaches to a relatively fixed constant at given economic, technological and institutional conditions. This conceptual understanding is supported by results from the empirical examination of the relationships between demands for carbon展开更多
Through analysis of the connotation of unconventional hydrocarbons,the source-reservoir assemblages of unconventional hydrocarbons are divided into three types,i.e.,source-reservoir neighboring type,source-reservoir i...Through analysis of the connotation of unconventional hydrocarbons,the source-reservoir assemblages of unconventional hydrocarbons are divided into three types,i.e.,source-reservoir neighboring type,source-reservoir integration type,and source-reservoir separation type.The source-reservoir neighboring type resources mainly include tight oil and tight gas with the following formation conditions and characteristics:(1)efficient near-source accumulation close to high-quality source rocks with the pressure difference between source and reservoir as the dynamic force;(2)large-area tight reservoirs with certain porosity,dominated by micro-nanopores of inorganic origin;(3)distributed in depressions and slopes with large hydrocarbon-bearing area and great resource quantity,low abundance and local development of“sweet spots”;(4)weak tectonism.The source-reservoir integration type resources mainly include coalbed methane,shale gas,shale oil and oil shale.The formation conditions and characteristics are:(1)high abundance of organic matter,different types of organic matter and thermal evolution grades leading to formation of different resources types;(2)organic-rich sections are distributed continuously in the reservoiring space which is dominated by nanometer organic pores,interparticle pores and microfissures;(3)hydrocarbons mainly occur in free or adsorbed state,varying much with resource type;(4)the resources are self-conserved,and enriched in depressions and slopes,the conservation conditions are controlled by tectonics,temperature and pressure;(5)the production per well can be enhanced by volume fracturing,which increases the permeability of the reservoirs.The source-reservoir separation type resources are more special,mainly including(1)transformed conventional resources such as oil sand and heavy oil;(2)unsteady resources formed under special conditions of temperature and pressure,among which natural gas hydrate is a representative.These three types of resources in China are different in both development prospect and current situation:(1)the source-reservoir neighboring type is most practical and will develop fast in the next 5 years;(2)the source-reservoir integration type needs continuous exploration and technical breakthrough,and is expected to develop rapidly in the coming decade;(3)in the source-reservoir separation type resources,natural gas hydrates have the greatest development potential,on which technical tests are being conducted.展开更多
Through analysis of four aspects,including the distribution and production of global oil and gas fields,the distribution and changes of remaining recoverable reserves,the differences in oil and gas production between ...Through analysis of four aspects,including the distribution and production of global oil and gas fields,the distribution and changes of remaining recoverable reserves,the differences in oil and gas production between regions/countries,and the development potential of oil and gas fields with production capacity not built and to be built,this paper presents the situation and trends of global oil and gas development in 2022.It is found that,in 2022,oil and gas fields are widely distributed worldwide,and upstream production activities continue to recover;the oil and gas reserves decrease slightly year on year,and the oil and gas reserves in sea areas increase significantly;the oil and gas production increases continuously,and the key resource countries make a significant contribution in oil and gas production growth;the oil and gas fields with production capacity not built and to be built hold abundant reserves,and their development potential will be gradually released with the economic benefits increase.Further analysis is conducted from the perspectives of global oil and gas resources continuity,geopolitical risks,potential of international cooperation,and upgrade of unconventional oil and gas technology.Finally,in view of core business domains and strategies under the new situation,the Chinese oil companies are recommended to:(1)keep a foothold in onshore conventional oil and gas development by virtue of their comparative advantages and learning from other’s experience in cooperation;(2)carry out pilot tests on development adjustment,and deepen the international cooperation in enhanced oil/gas recovery;(3)improve the oil and gas operation capabilities in sea areas to transform from follower as minority shareholder to joint venture and then to independent operations;and(4)seek appropriate ways for shale oil/gas development to reduce the dependence on foreign oil and gas.展开更多
With the increasing severity of environmental problems,many countries have set energy transition targets to promote the realization of the Paris Agreement.There has been a global consensus on utilizing solar energy re...With the increasing severity of environmental problems,many countries have set energy transition targets to promote the realization of the Paris Agreement.There has been a global consensus on utilizing solar energy resources as alternatives to conventional sources to support this energy transition.In this regard,analyzing the“location,”“quantity,”and“quality”of global solar energy resources will not only assist an individual country to efficiently utilize these resources but also promote the realization of large-scale intercontinental resource utilization and complementation.This study established the basic database,model methods,and platform tools for global solar energy assessment,Then,a global solar energy resource assessment was conducted,which included the theoretical reserves(TRs),technical installed potential capacity(TPIC),and average development cost(ADC).A comparative analysis of the assessment results for all continents was also performed.After that,based on big data analysis and geographic information system(GIS)calculations,the distribution characteristics of the global solar power TPIC were calculated with the two core indicators,namely the capacity factor and ADC.Furthermore,a data-driven quantitative evaluation of the refined development potential of solar energy resources was performed.Finally,the reasonableness and coincidence analysis of the resource assessment results were verified using data from global and specifically Chinese photovoltaic(PV)bases.展开更多
By analyzing the distribution of global oil and gas fields and the reasons why some oil and gas fields are not in production, the distribution characteristics of oil and gas remaining recoverable reserves and their ye...By analyzing the distribution of global oil and gas fields and the reasons why some oil and gas fields are not in production, the distribution characteristics of oil and gas remaining recoverable reserves and their year-on-year changes, the distribution characteristics of oil and gas production and their year-on-year changes, and the development potential of oil and gas to be tapped in 2021, this paper sorts out systematically the current status and characteristics of global oil and gas development, summaries the major trends of global oil and gas development, puts forward enlightenment for international oil and gas cooperation. In 2021, oil and gas fields were widely distributed, the number of non-producing oil and gas fields was large;the whole oil and gas remaining recoverable reserves declined slightly, unconventional oil and gas remaining recoverable reserves dropped significantly;the overall oil and gas production continuously increased, the outputs of key resource-host countries kept year-on-year growth;undeveloped oilfields had abundant reserves and great development potential. Combined with global oil and gas geopolitics, oil and gas industry development trends, oil and gas investment intensity, and the tracking and judgment of hotspot fields, the major trends of global oil and gas development in 2021 are summarized. On this basis, the four aspects of enlightenment and suggestions for international oil and gas cooperation and development strategies are put forward: attach great importance to the obligation of marine abandonment to ensure high-quality and long-term benefit development of offshore oil and gas;adhere to the principle of not going to dangerous and chaotic places, strengthen the concentration of oil and gas assets, and establish multi stable supply bases;based on the multi-scenario demand of natural gas, realize the transformation from integrated collaboration to full oil and gas industry chain development;increase the acquisition of high-quality large-scale assets, and pay attention to the continuous optimization of the shareholding ratio of projects at different stages.展开更多
Microorganisms, regardless of whether pathogenic or not, may cause enormous economic losses due to adverse effects on human and animal health, or by damaging the quality of the agricultural and food products. Based on...Microorganisms, regardless of whether pathogenic or not, may cause enormous economic losses due to adverse effects on human and animal health, or by damaging the quality of the agricultural and food products. Based on these effects, the development of prompt molecular methods and their involvement in the practical pathogen diagnostic diagnostics is more than actual. This paper is focused on the evaluation of easy-to-perform and highly budget-friendly, PCR-related DNA purification protocols for diagnostic purposes especially in water or similar simple matrices. The slight modifications of earlier described DNA isolation methods, which rely on chelate exchange resin and/or ethanol-sodium-based heat lysis, we reevaluated in comparison with a widely used commercial kit. The efficiency of DNA purification techniques was assessed from Gramnegative as well as Gram-positive bacteria and yeast using quantitative PCR. The effectivity of different methods tested may vary depending on the bacterial or yeast species in question. Nevertheless, in our hands, the chelate exchange resin-based methods were found to be the most robust and/or satisfying at least by an acceptable reproducibility rate. Our presented results support the potential of low-cost but still sensitive molecular microbe detection procedures consisting of only a few pipetting steps resulting in good reproducibility and the least possible environmental burden, serving as a good starting point for developments of matrix-specific processes and methods.展开更多
Rural revitalization strategy is an important strategic layout of rural development in the new era of the CPC Central Committee,and scientific and reasonable determination of village types is an important measure to p...Rural revitalization strategy is an important strategic layout of rural development in the new era of the CPC Central Committee,and scientific and reasonable determination of village types is an important measure to promote rural revitalization by classification.The villages of Wan’an County were selected as the research object.Firstly,the factors that have a key impact on the development of the villages were extracted and qualitatively analyzed to preliminarily screen and judge their types.Secondly,the evaluation index system of development potential of the villages was constructed to quantitatively evaluate and reasonably classify the villages.Finally,the spatial distribution characteristics and quantity of different villages were revealed,and differentiated development strategies were proposed.展开更多
In the traditional views on developmental biology, the process of a mammal from a zygote to. an adult individual follows continuous changes of space and time environments and is the result of different expressions of ...In the traditional views on developmental biology, the process of a mammal from a zygote to. an adult individual follows continuous changes of space and time environments and is the result of different expressions of target genes. It has long been known that this process is irreversible and the terminal differentiated adult cells, such as cardiac myocytes and neurons, will not divide and differentiate. But recent reports on the two hottest fields - cloning medicine and stem cell biology doubted these concepts. This may lead to a further understanding of the potentiality of mammal development and may provide great chances for commercial and clinical practice.展开更多
Chemically defined medium is widely used for culturing mouse embryonic stem cells(mESCs),in which N2B27 works as a substitution for serum,and GSK3βand MEK inhibitors(2i)help to promote ground-state pluripo-tency.Howe...Chemically defined medium is widely used for culturing mouse embryonic stem cells(mESCs),in which N2B27 works as a substitution for serum,and GSK3βand MEK inhibitors(2i)help to promote ground-state pluripo-tency.However,recent studies suggested that MEKi might cause irreversible defects that compromise the developmental potential of mESCs.Here,we demon-strated the deficient bone morphogenetic protein(BMP)signal in the chemically defined condition is one of the main causes for the impaired pluripotency.Mechanisti-cally,activating the BMP signal pathway by BMP4 could safeguard the chromosomal integrity and proliferation capacity of mESCs through regulating downstream tar-gets Ube2s and Chmp4b.More importantly,BMP4 pro-motes a distinct in vivo developmental potential and a long-term pluripotency preservation.Besides,the pluripotent improvements driven by BMP4 are superior to those by attenuating MEK suppression.Taken together,our study shows appropriate activation of BMP signal is essential for regulating functional pluripotency and reveals that BMP4 should be applied in the serum-free culture system.展开更多
Traditional music is an important component of cultural heritage.However,studies have scarcely explored the tourism development potential and the obstacle factors of traditional music.This study takes Xiangxi as the r...Traditional music is an important component of cultural heritage.However,studies have scarcely explored the tourism development potential and the obstacle factors of traditional music.This study takes Xiangxi as the research site,constructs an evaluation index system,and utilizes survey and geographical methods.The major research results are as follows:First,the average potential of resource endowment,tourism industry development,and socio-economic conditions are 0.28,0.36,and 0.24,respectively.The potential of resource endowment is higher in the west and lower in the east,that of tourism industry development is higher in the north and south and lower in the center,and that of socio-economic conditions is higher in the south and lower in the north.Second,the comprehensive potential is 0.29,which is higher in the northwest and southwest regions.Coordination in most administrative units is at a medium level,and most regions have obvious advantages in resource endowment.Third,the primary obstacle factor is socio-economic conditions(39.21%),followed by resource endowment(30.73%)and tourism industry development(30.06%).The administrative units can be classified into four groups:socio-economic condition obstacle,resource endowment and tourism industry development obstacles,resource endowment and socio-economic condition obstacles,and tourism industry development and socio-economic condition obstacles.The highest priority goals for Xiangxi involve economic development and the integration of modern technologies to stimulate passenger flow.For reg traditional music items(eastern area of Xiangxi),tourism development should be restrained and other resources with stronger inherent advantages should be exploited.This study explored the quantification of traditional music tourism potential,representing a novel breakthrough in this field of research.The indicator system and research methods used in this study can provide guidance and methodological references for cultural heritage research.The suggestions proposed in this article contribute to the rational development and effective protection of cultural heritage resources and the healthy development of the tourism industry.展开更多
The oil in the Jurassic Da'anzhai reservoirs in the Sichuan Basin is unconventional tight oil,which accumulated in or near source rocks,and did not experience extensive migration in a large-scale long distance.The...The oil in the Jurassic Da'anzhai reservoirs in the Sichuan Basin is unconventional tight oil,which accumulated in or near source rocks,and did not experience extensive migration in a large-scale long distance.The first submember,second submember and third submember of Da'anzhai Member are dominated by shell limestone which is widely and continuously distributed,and are typical near-source lacustrine shell limestone tight reservoirs.Complex lithology,multiple types of reservoir space and complicated pore structure are developed in these reservoirs.The effective reservoir space mainly includes micro-pores and micro-fractures with strong fabric selectivity.The petrophysics experiment reveals that the average connected matrix porosity of tight oil reservoir in Jurassic Da'anzhai Member is about 2.13%,lower than that of other tight oil reservoirs but higher than the average effective porosity(0.97%)from previous single alcohol-saturated method.According to production performance data,the Da'anzhai shell limestone reservoir is not a simple porous or fractured reservoir,but has complex porethroat-fracture association or storage-seepage mode.Because the development of fossil shells controls the development of micro-fractures,fluids are difficult to enter into but easy to escape from the reservoirs.Although the pore-throat is fine,the sorting is poor and the displacement pressure is high,the movable fluid saturation and mercury ejection efficiency of the reservoir in the Da'anzhai Member is only slightly lower than that of some storage-seepage modes,and higher than that of Oil-bearing Group 7 of Yanchang Formation in the Ordos Basin.The reservoir in the Da'anzhai Member is one of the few tight oil reservoirs with high natural productivity.The tight oil in the shell limestone of the Da'anzhai Member has great development potential,but its extensive and effective development also has some challenges,such as high seepage resistance of matrix and ineffective single development mode.The development mode of the Da'anzhai tight oil should draw lessons from the Bakken Formation in North America and Oil-bearing Gourp 7 of Yanchang Formation in the Ordos Basin,and thus,effective development technologies based on volume fracturing and fine operation for shell limestone tight oil in the Da'anzhai Member in Sichuan Basin are developed to realize the development of profit and scale.展开更多
文摘With the advent of the era of big data and artificial intelligence, new infrastructure construction(NIC) has attracted the attention of many countries. The development of NIC provides an opportunity to bridge the digital divide and narrow the regional gap,providing continuous impetus to further promote economic development. Here, we considered 31 provincial-level administrative units in China(not including Hong Kong, Macao, and Taiwan of China due to data unavailable) and established comprehensive evaluation indicators for the development potential of NIC. Afterward, we used the entropy-weight TOPSIS model to determine the development potential of NIC and analyze its spatio-temporal evolution characteristics. Furthermore, the GeoDetector model was applied to explore the driving mechanism of the NIC development potential. The conclusions were as follows: (1) The Chinese NIC development potential is generally low. The eastern China was the region with the highest development potential year by year, while the development potential in the central China was found to be in an accelerating phase. (2) The evolution of the Chinese NIC development potential’s spatial pattern has been characterized by an inland extension and coastal agglomeration. Moreover, we identified a superior development zone, a rising development zone, an inferior development zone, and a declining development zone. (3) The scope of Chinese NIC development potential agglomeration areas has gradually expanded and its degree has gradually deepened. The range of high-value agglomeration in eastern area gradually expanded and its degree gradually deepened. (4) Investment in innovative talents appears as the core factor affecting the Chinese NIC development potential. Whether acting alone or synergistically with other factors, its promoting effect on Chinese NIC development potential is the strongest.
文摘Based on an investigation of the meaning of development, the neo-classical economic approach to development, and the post-welfarist theory of development, this paper proposes a conceptual framework for understanding human development potentials, while undertaking empirical analysis using cross-sectional and time series data on human development. Human development is associated with basic necessities for subsistence, the quality of life, and political and civil rights, in addition to income indicators. Our analysis suggests that the concept of human development potentials has two dimensions: the rights of development and limits to human development. Both are largely ignored in the neoclassical theory of development. However, human development is not unbounded, which approaches to a relatively fixed constant at given economic, technological and institutional conditions. This conceptual understanding is supported by results from the empirical examination of the relationships between demands for carbon
基金This work was funded by National Science and Technology Major Project of China(Grant No.2011ZX05043)Major Science and Technology Special Project of China National Petroleum Corporation(Grant No:2013E-0502)。
文摘Through analysis of the connotation of unconventional hydrocarbons,the source-reservoir assemblages of unconventional hydrocarbons are divided into three types,i.e.,source-reservoir neighboring type,source-reservoir integration type,and source-reservoir separation type.The source-reservoir neighboring type resources mainly include tight oil and tight gas with the following formation conditions and characteristics:(1)efficient near-source accumulation close to high-quality source rocks with the pressure difference between source and reservoir as the dynamic force;(2)large-area tight reservoirs with certain porosity,dominated by micro-nanopores of inorganic origin;(3)distributed in depressions and slopes with large hydrocarbon-bearing area and great resource quantity,low abundance and local development of“sweet spots”;(4)weak tectonism.The source-reservoir integration type resources mainly include coalbed methane,shale gas,shale oil and oil shale.The formation conditions and characteristics are:(1)high abundance of organic matter,different types of organic matter and thermal evolution grades leading to formation of different resources types;(2)organic-rich sections are distributed continuously in the reservoiring space which is dominated by nanometer organic pores,interparticle pores and microfissures;(3)hydrocarbons mainly occur in free or adsorbed state,varying much with resource type;(4)the resources are self-conserved,and enriched in depressions and slopes,the conservation conditions are controlled by tectonics,temperature and pressure;(5)the production per well can be enhanced by volume fracturing,which increases the permeability of the reservoirs.The source-reservoir separation type resources are more special,mainly including(1)transformed conventional resources such as oil sand and heavy oil;(2)unsteady resources formed under special conditions of temperature and pressure,among which natural gas hydrate is a representative.These three types of resources in China are different in both development prospect and current situation:(1)the source-reservoir neighboring type is most practical and will develop fast in the next 5 years;(2)the source-reservoir integration type needs continuous exploration and technical breakthrough,and is expected to develop rapidly in the coming decade;(3)in the source-reservoir separation type resources,natural gas hydrates have the greatest development potential,on which technical tests are being conducted.
基金Supported by the PetroChina Science and Technology Project(2021DJ3205).
文摘Through analysis of four aspects,including the distribution and production of global oil and gas fields,the distribution and changes of remaining recoverable reserves,the differences in oil and gas production between regions/countries,and the development potential of oil and gas fields with production capacity not built and to be built,this paper presents the situation and trends of global oil and gas development in 2022.It is found that,in 2022,oil and gas fields are widely distributed worldwide,and upstream production activities continue to recover;the oil and gas reserves decrease slightly year on year,and the oil and gas reserves in sea areas increase significantly;the oil and gas production increases continuously,and the key resource countries make a significant contribution in oil and gas production growth;the oil and gas fields with production capacity not built and to be built hold abundant reserves,and their development potential will be gradually released with the economic benefits increase.Further analysis is conducted from the perspectives of global oil and gas resources continuity,geopolitical risks,potential of international cooperation,and upgrade of unconventional oil and gas technology.Finally,in view of core business domains and strategies under the new situation,the Chinese oil companies are recommended to:(1)keep a foothold in onshore conventional oil and gas development by virtue of their comparative advantages and learning from other’s experience in cooperation;(2)carry out pilot tests on development adjustment,and deepen the international cooperation in enhanced oil/gas recovery;(3)improve the oil and gas operation capabilities in sea areas to transform from follower as minority shareholder to joint venture and then to independent operations;and(4)seek appropriate ways for shale oil/gas development to reduce the dependence on foreign oil and gas.
基金supported by National Science and Technology Major Project(2018YFB0904000).
文摘With the increasing severity of environmental problems,many countries have set energy transition targets to promote the realization of the Paris Agreement.There has been a global consensus on utilizing solar energy resources as alternatives to conventional sources to support this energy transition.In this regard,analyzing the“location,”“quantity,”and“quality”of global solar energy resources will not only assist an individual country to efficiently utilize these resources but also promote the realization of large-scale intercontinental resource utilization and complementation.This study established the basic database,model methods,and platform tools for global solar energy assessment,Then,a global solar energy resource assessment was conducted,which included the theoretical reserves(TRs),technical installed potential capacity(TPIC),and average development cost(ADC).A comparative analysis of the assessment results for all continents was also performed.After that,based on big data analysis and geographic information system(GIS)calculations,the distribution characteristics of the global solar power TPIC were calculated with the two core indicators,namely the capacity factor and ADC.Furthermore,a data-driven quantitative evaluation of the refined development potential of solar energy resources was performed.Finally,the reasonableness and coincidence analysis of the resource assessment results were verified using data from global and specifically Chinese photovoltaic(PV)bases.
基金Scientific Research and Technology Development Project(2021DJ3205)。
文摘By analyzing the distribution of global oil and gas fields and the reasons why some oil and gas fields are not in production, the distribution characteristics of oil and gas remaining recoverable reserves and their year-on-year changes, the distribution characteristics of oil and gas production and their year-on-year changes, and the development potential of oil and gas to be tapped in 2021, this paper sorts out systematically the current status and characteristics of global oil and gas development, summaries the major trends of global oil and gas development, puts forward enlightenment for international oil and gas cooperation. In 2021, oil and gas fields were widely distributed, the number of non-producing oil and gas fields was large;the whole oil and gas remaining recoverable reserves declined slightly, unconventional oil and gas remaining recoverable reserves dropped significantly;the overall oil and gas production continuously increased, the outputs of key resource-host countries kept year-on-year growth;undeveloped oilfields had abundant reserves and great development potential. Combined with global oil and gas geopolitics, oil and gas industry development trends, oil and gas investment intensity, and the tracking and judgment of hotspot fields, the major trends of global oil and gas development in 2021 are summarized. On this basis, the four aspects of enlightenment and suggestions for international oil and gas cooperation and development strategies are put forward: attach great importance to the obligation of marine abandonment to ensure high-quality and long-term benefit development of offshore oil and gas;adhere to the principle of not going to dangerous and chaotic places, strengthen the concentration of oil and gas assets, and establish multi stable supply bases;based on the multi-scenario demand of natural gas, realize the transformation from integrated collaboration to full oil and gas industry chain development;increase the acquisition of high-quality large-scale assets, and pay attention to the continuous optimization of the shareholding ratio of projects at different stages.
文摘Microorganisms, regardless of whether pathogenic or not, may cause enormous economic losses due to adverse effects on human and animal health, or by damaging the quality of the agricultural and food products. Based on these effects, the development of prompt molecular methods and their involvement in the practical pathogen diagnostic diagnostics is more than actual. This paper is focused on the evaluation of easy-to-perform and highly budget-friendly, PCR-related DNA purification protocols for diagnostic purposes especially in water or similar simple matrices. The slight modifications of earlier described DNA isolation methods, which rely on chelate exchange resin and/or ethanol-sodium-based heat lysis, we reevaluated in comparison with a widely used commercial kit. The efficiency of DNA purification techniques was assessed from Gramnegative as well as Gram-positive bacteria and yeast using quantitative PCR. The effectivity of different methods tested may vary depending on the bacterial or yeast species in question. Nevertheless, in our hands, the chelate exchange resin-based methods were found to be the most robust and/or satisfying at least by an acceptable reproducibility rate. Our presented results support the potential of low-cost but still sensitive molecular microbe detection procedures consisting of only a few pipetting steps resulting in good reproducibility and the least possible environmental burden, serving as a good starting point for developments of matrix-specific processes and methods.
文摘Rural revitalization strategy is an important strategic layout of rural development in the new era of the CPC Central Committee,and scientific and reasonable determination of village types is an important measure to promote rural revitalization by classification.The villages of Wan’an County were selected as the research object.Firstly,the factors that have a key impact on the development of the villages were extracted and qualitatively analyzed to preliminarily screen and judge their types.Secondly,the evaluation index system of development potential of the villages was constructed to quantitatively evaluate and reasonably classify the villages.Finally,the spatial distribution characteristics and quantity of different villages were revealed,and differentiated development strategies were proposed.
基金This work was supported by the "973" Project (Grant No. G1999054205).
文摘In the traditional views on developmental biology, the process of a mammal from a zygote to. an adult individual follows continuous changes of space and time environments and is the result of different expressions of target genes. It has long been known that this process is irreversible and the terminal differentiated adult cells, such as cardiac myocytes and neurons, will not divide and differentiate. But recent reports on the two hottest fields - cloning medicine and stem cell biology doubted these concepts. This may lead to a further understanding of the potentiality of mammal development and may provide great chances for commercial and clinical practice.
基金This work was supported by the National Key R&D Program of China(2020YFA0112500 and 2021YFA1100300)the National Natural Science Foundation of China(31721003,31820103009,92168205,32070857 and 31871446)+3 种基金the Young Elite Scientist Sponsorship Program by CAST(2018QNRC001)the key project of the Science and Technology of Shanghai Municipality(19JC1415300)the Shanghai Rising-Star Program(19QA1409600)the Shanghai municipal medical and health discipline construction projects(no.2017ZZ02015).
文摘Chemically defined medium is widely used for culturing mouse embryonic stem cells(mESCs),in which N2B27 works as a substitution for serum,and GSK3βand MEK inhibitors(2i)help to promote ground-state pluripo-tency.However,recent studies suggested that MEKi might cause irreversible defects that compromise the developmental potential of mESCs.Here,we demon-strated the deficient bone morphogenetic protein(BMP)signal in the chemically defined condition is one of the main causes for the impaired pluripotency.Mechanisti-cally,activating the BMP signal pathway by BMP4 could safeguard the chromosomal integrity and proliferation capacity of mESCs through regulating downstream tar-gets Ube2s and Chmp4b.More importantly,BMP4 pro-motes a distinct in vivo developmental potential and a long-term pluripotency preservation.Besides,the pluripotent improvements driven by BMP4 are superior to those by attenuating MEK suppression.Taken together,our study shows appropriate activation of BMP signal is essential for regulating functional pluripotency and reveals that BMP4 should be applied in the serum-free culture system.
基金Project of Hunan Provincial Social Science Achievement Evaluation Committee,No.XSP2023GLC023Excellent Youth Program of the Education Department of Hunan Province,No.22B0692+2 种基金National Natural Science Fundation of China,No.41971191,No.42171213Project of Hunan University of Arts and Science,No.22BSQD15Project of Henan Philosophy and Social Sciences,No.2022BJJ026。
文摘Traditional music is an important component of cultural heritage.However,studies have scarcely explored the tourism development potential and the obstacle factors of traditional music.This study takes Xiangxi as the research site,constructs an evaluation index system,and utilizes survey and geographical methods.The major research results are as follows:First,the average potential of resource endowment,tourism industry development,and socio-economic conditions are 0.28,0.36,and 0.24,respectively.The potential of resource endowment is higher in the west and lower in the east,that of tourism industry development is higher in the north and south and lower in the center,and that of socio-economic conditions is higher in the south and lower in the north.Second,the comprehensive potential is 0.29,which is higher in the northwest and southwest regions.Coordination in most administrative units is at a medium level,and most regions have obvious advantages in resource endowment.Third,the primary obstacle factor is socio-economic conditions(39.21%),followed by resource endowment(30.73%)and tourism industry development(30.06%).The administrative units can be classified into four groups:socio-economic condition obstacle,resource endowment and tourism industry development obstacles,resource endowment and socio-economic condition obstacles,and tourism industry development and socio-economic condition obstacles.The highest priority goals for Xiangxi involve economic development and the integration of modern technologies to stimulate passenger flow.For reg traditional music items(eastern area of Xiangxi),tourism development should be restrained and other resources with stronger inherent advantages should be exploited.This study explored the quantification of traditional music tourism potential,representing a novel breakthrough in this field of research.The indicator system and research methods used in this study can provide guidance and methodological references for cultural heritage research.The suggestions proposed in this article contribute to the rational development and effective protection of cultural heritage resources and the healthy development of the tourism industry.
基金supported by the project of the PetroChina Research Institute of Petroleum Exploration and Development(2016yj01)the National Science and Technology Major Project of China(No.2016ZX05046-003).
文摘The oil in the Jurassic Da'anzhai reservoirs in the Sichuan Basin is unconventional tight oil,which accumulated in or near source rocks,and did not experience extensive migration in a large-scale long distance.The first submember,second submember and third submember of Da'anzhai Member are dominated by shell limestone which is widely and continuously distributed,and are typical near-source lacustrine shell limestone tight reservoirs.Complex lithology,multiple types of reservoir space and complicated pore structure are developed in these reservoirs.The effective reservoir space mainly includes micro-pores and micro-fractures with strong fabric selectivity.The petrophysics experiment reveals that the average connected matrix porosity of tight oil reservoir in Jurassic Da'anzhai Member is about 2.13%,lower than that of other tight oil reservoirs but higher than the average effective porosity(0.97%)from previous single alcohol-saturated method.According to production performance data,the Da'anzhai shell limestone reservoir is not a simple porous or fractured reservoir,but has complex porethroat-fracture association or storage-seepage mode.Because the development of fossil shells controls the development of micro-fractures,fluids are difficult to enter into but easy to escape from the reservoirs.Although the pore-throat is fine,the sorting is poor and the displacement pressure is high,the movable fluid saturation and mercury ejection efficiency of the reservoir in the Da'anzhai Member is only slightly lower than that of some storage-seepage modes,and higher than that of Oil-bearing Group 7 of Yanchang Formation in the Ordos Basin.The reservoir in the Da'anzhai Member is one of the few tight oil reservoirs with high natural productivity.The tight oil in the shell limestone of the Da'anzhai Member has great development potential,but its extensive and effective development also has some challenges,such as high seepage resistance of matrix and ineffective single development mode.The development mode of the Da'anzhai tight oil should draw lessons from the Bakken Formation in North America and Oil-bearing Gourp 7 of Yanchang Formation in the Ordos Basin,and thus,effective development technologies based on volume fracturing and fine operation for shell limestone tight oil in the Da'anzhai Member in Sichuan Basin are developed to realize the development of profit and scale.
