The Second Tibetan Plateau Scientific Expedition and Research Program tasked a research team with the“Investigation of the water vapor channel of the Yarlung Zsangbo Grand Canyon(INVC)”in the southeastern Tibetan Pl...The Second Tibetan Plateau Scientific Expedition and Research Program tasked a research team with the“Investigation of the water vapor channel of the Yarlung Zsangbo Grand Canyon(INVC)”in the southeastern Tibetan Plateau(TP).This paper summarizes the scientific achievements obtained from the data collected by the INVC observation network and highlights the progress in investigating the development of heavy rainfall events associated with water vapor changes.The rain gauge network of the INVC can represent the impacts of the Yarlung Zsangbo Grand Canyon(YGC)topography on precipitation at the hourly scale.The microphysical characteristics of the precipitation in the YGC are different than those in the lowland area.The GPM-IMERG(Integrated MultisatellitE Retrievals for Global Precipitation Measurement)satellite precipitation data for the YGC region should be calibrated before they are used.The meridional water vapor flux through the YGC is more important than the zonal flux for the precipitation over the southeastern TP.The decreased precipitation around the YGC region is partly due to the decreased meridional water vapor flux passing through the YGC.High-resolution numerical models can benefit precipitation forecasting in this region by using a combination of specific schemes that capture the valley wind and water vapor flux along the valley floor.展开更多
Ground-based microwave radiometers(MWRs)operating in the K-and V-bands(20–60 GHz)can help us obtain temperature and humidity profiles in the troposphere.Aside from some soundings from local meteorological observatori...Ground-based microwave radiometers(MWRs)operating in the K-and V-bands(20–60 GHz)can help us obtain temperature and humidity profiles in the troposphere.Aside from some soundings from local meteorological observatories,the tropospheric atmosphere over the Tibetan Plateau(TP)has never been continuously observed.As part of the Chinese Second Tibetan Plateau Scientific Expedition and Research Program(STEP),the Tibetan Plateau Atmospheric Profile(TPPROFILE)project aims to construct a comprehensive MWR troposphere observation network to study the synoptic processes and environmental changes on the TP.This initiative has collected three years of data from the MWR network.This paper introduces the data information,the data quality,and data downloading.Some applications of the data obtained from these MWRs were also demonstrated.Our comparisons of MWR against the nearest radiosonde observation demonstrate that the TP-PROFILE MWR system is adequate for monitoring the thermal and moisture variability of the troposphere over the TP.The continuous temperature and moisture profiles derived from the MWR data provide a unique perspective on the evolution of the thermodynamic structure associated with the heating of the TP.The TP-PROFILE project reveals that the low-temporal resolution instruments are prone to large uncertainties in their vapor estimation in the mountain valleys on the TP.展开更多
Tomato(Solanum lycopersicum)is a perishable fruit because of its fast water loss and susceptibility to pathogens in the post-harvest stage,which leads to huge economic losses every year.In this study,firstly from 19 t...Tomato(Solanum lycopersicum)is a perishable fruit because of its fast water loss and susceptibility to pathogens in the post-harvest stage,which leads to huge economic losses every year.In this study,firstly from 19 tomato cultivars,we screened out two cultivars,Riogrand and SalarF1,having long and short shelf-life spans,respectively.Secondly,shelf-life analysis was carried out for both cultivars at room temperature.Results exhibited that Riogrand showed higher firmness and less weight loss than SalarF1.The ethylene production was higher in SalarF1,compared with Riogrand during post-harvest storages.We performed transcriptomic analysis of both cultivars in different storage stages.We discovered 2913,2188,and 11,119 differentially expressed genes(DEGs)for three post-harvest stages(0,20,and 40 Days Post-Harvest(DPH)),respectively.These genes are enriched in ethylene biosynthesis and response,as well as cell wall-related genes.Ethylene response factor(ERF)ERF2 and ERF4 were highly expressed in SalarF1 with a short shelf life in 40 DPH,and the ethylene biosynthetic genes ACO1,ACO4,ACS6,and ACS2 were significantly upregulated in SalarF1.Regarding cell wall loosening and cell wall-related genes XTH3,XTH7,XTH23,1,3;1,4-β-D-Gluc-like,pGlcT1,Cellulase,PGH1,PL5,PL-like 1,PL-like 2 exhibited the highest levels of significance,being notably upregulated in the last stage of SalarF1.The quantitative real-time polymerase chain reaction(qRT-PCR)analysis validated these gene expressions,which is in line with the transcriptome analysis.The findings suggested that the extension of tomato fruit shelf life is mostly dependent on ethylene biosynthesis,signaling pathway genes,cell wall loosening,and cell wall-associated genes.展开更多
Geminal dinitropropyl ester plasticizers(DNPEPs) possess excellent energetic performances which provide good potentials as insensitive plasticizer. In this study, we design and synthesize DNPEPs with different alkane ...Geminal dinitropropyl ester plasticizers(DNPEPs) possess excellent energetic performances which provide good potentials as insensitive plasticizer. In this study, we design and synthesize DNPEPs with different alkane chain parts, and systematically investigate their structure-property relationships.Results show that DNPEPs have impact sensitivities all higher than 25.2 J, thermal decomposition temperatures all higher than 254 ℃, and glass transition temperatures(T_(g)) lower than-90 ℃.Furthermore, the effects of DNPEPs as plasticizer are studied on hydroxyl terminated polybutadiene(HTPB) in detail, including the viscosity, glass transition temperatures and others. It is noteworthy that 2,2-dinitropropyl nonanoate(DNPNc) among these DNPEPs exhibits the most expected simultaneous tuning effects on both viscosity and T_(g) of HTPB systems, providing favorable potentials to replace the conventional plastizers as dioctyl sebacate(DOS) in the HTPB based propellants and explosives.展开更多
It has been long recognized that a variety of anthropogenic activities may cause earthquakes(Ellsworth et al.,2013;Yang HF et al.,2017).In the recent decades,induced earthquakes have been found in many settings and be...It has been long recognized that a variety of anthropogenic activities may cause earthquakes(Ellsworth et al.,2013;Yang HF et al.,2017).In the recent decades,induced earthquakes have been found in many settings and become a growing concern,in particular for regions that are undergoing with resource development.展开更多
Purpose: This study explores new content, forms, and fields of science and technology(S&T;) innovation and entrepreneurship information services of the National Science Library of the Chinese Academy of Sciences(N...Purpose: This study explores new content, forms, and fields of science and technology(S&T;) innovation and entrepreneurship information services of the National Science Library of the Chinese Academy of Sciences(NSLC).Design/methodology/approach: We cooperated with incubator enterprises and set up an "S&T; Innovation and Entrepreneurship Information Service Platform." We designed five series of activities, including industrial information release, project financing and roadshows, entrepreneurial sharing, entrepreneurial coaching sessions, and entrepreneurial salons. Based on the implementation of these activities, we designed new NSLC library services for S&T; innovation and entrepreneurship.Findings: Since the construction of the platform, these five series of activities have attracted more than 80 business projects, 90 investors, and 30 researchers. Furthermore, more than 20 media representatives and nearly 300 entrepreneurs have participated in the activities that the NSLC has organized in the past two years. Through these activities, we have defined an S&T; innovation and entrepreneurship knowledge service model for the NSLC.Research limitations: The service practice of the NSLC is still in the demonstration phase. Due to staffing limitations of our service teams, the expansion of our service activities has been greatly restricted.Practical implications: The innovation and entrepreneurship information services of the NSLC provide a lot of material for transformation of library services for domestic and foreign special libraries.Originality/value: It is useful to transform library and business services by embedding them into ways in which we serve innovation and entrepreneurial activities. This opens up a new field of library knowledge services in China.展开更多
Purpose: This study aims to establish a new framework for evaluating science and technology (S&T) competitiveness that is appropriate to meet the needs of provincial academies of sciences (PASs) in China.Design/...Purpose: This study aims to establish a new framework for evaluating science and technology (S&T) competitiveness that is appropriate to meet the needs of provincial academies of sciences (PASs) in China.Design/methodology/approaches: An evaluation index, including such assessing indicators as research strength, research impact, research development and trends, and regional contributions, is developed for China's PASs. Taking the Jiangxi Academy of Sciences (JXAS) as an example, we first explain how to apply this framework to analyze the strengths and weaknesses of PASs in China. Then, we compare the results of all 17 PASs in order to get a comprehensive understanding of their competitiveness.Findings: Our results show the development path, current status, innovation advantages, and weaknesses of JXAS very clearly. Based on our comparative analysis, we ranked the 17 PASs from the perspective of different dimensions, by which their competitiveness strengths and weaknesses can be highlighted for improvement.Research limitations: In this analysis, we did not take S&T policies, S&T systems, or historical factors into consideration. Thus, we may have ignored the influence of the soft individual differences of different PASs in China..Practical implications: The evaluation index developed in this paper provides a useful insight into an analytical method that can be used by PASs or other provincial research institutions (PRIs) to assess their competitiveness.Originality/value: Compared with existing evaluation frameworks, our method has two main characteristics: First, we added three new dimensions, including the PASs' applicable research outputs, regional contributions, and comparative advantages; second, we conducted a comparative analysis of local research institutes in their different advantaged industrial areas, which makes our analytical method more comprehensive for local research institutions.展开更多
Purpose:As scientific resources are widely distributed,researchers often have difficulties in acquiring information from different individual sources.This paper intends to present a new approach to construct a subject...Purpose:As scientific resources are widely distributed,researchers often have difficulties in acquiring information from different individual sources.This paper intends to present a new approach to construct a subject-knowledge-based integration platform which was carried out by the Institute of Software,Chinese Academy of Sciences(ISCAS).Our aim is to use technique tools to strengthen the library service by combining a variety of information service resources with knowledge tools.Design/methodology/approach:Based on the analysis of users’ needs,we established a collaborative team across ISCAS Library,National Science Library of CAS(NSL CAS),and ISCAS’ research groups or research labs.With the service tools developed by ISCAS Library,we embedded other multipurpose utility tools of knowledge integration into the platform as to make full use of software tools in knowledge integration,knowledge fusion,and intelligent push of library services to end users.Findings:With a hard effort of the construction team,the ISCAS subject group platform(hereinafter as ISCAS Platform) has integrated such information resources as institutional repository(IR) of ISCAS,open resources from websites and subject resources of computer sciences.Up to date,ISCAS platform can provide integrated information services including data collection for computer science and intelligent generation of citation reports,by means of embedding self-developed discovering tools for domain experts and subject content,and generation tools for scientific citation reports.Research limitations:Knowledge organization need be further improved in the ISCAS subject group platform.In addition,functions for academic exchanges need be maximized as to meet the individual demands of researchers for library services at the Platform.Practical implications:Since we Platform has been put into use through the Library website of the ISCAS in June 2012,many academic libraries from both domestic universities and CAS institutes have showed their strong interest for our self-developed tools,among which more than 10 cooperation partnerships have been formed.Originality/value:Through self-developed service tools and the integration of multiple-type resources,our Platform has solved such key problems as timely access and update of the trusted resources from a third party,and the rapid fusion and extension of library resources while establishing subject knowledge environment.So the ISCAS library can provide a flexible customization of library services according to the need of different users.展开更多
An explanation of the meso-mechanism of sand granular materials for the uniqueness of critical state is presented by means of the discrete element method(DEM)under flexible boundary loading conditions.A series triaxia...An explanation of the meso-mechanism of sand granular materials for the uniqueness of critical state is presented by means of the discrete element method(DEM)under flexible boundary loading conditions.A series triaxial drainage shear test(DEM simulations),in conjunction with the flexible boundary technique,of were performed for sand samples subjected to various physical states and with different particle size distributions.After carefully investigating the critical status of the results of the numerical calculation,the macroscopic failure modes and shear band evolution of sand,as well as the velocity vector field due to different initial states,were explored and classified.Furthermore,the evaluation rules and discrepancies between overall void ratios of the specimen and local void ratios within the shear band under the critical state were recorded and analyzed.The results proved that a sample with a small void tends to form a shear band,and the rotation of the particles in the non-shear zone is negligible.Conversely,sandy soil with large initial void ratios exhibited limited development of significant shear bands,and the change in void ratios within the shear region and the non-shear area are not significant.Interestingly,the particle-size distribution exerts minimal influence on the evolution rule which the void ratio converges within the shear band and diverges outside the shear region for both multi-stage and single-stage specimens.The void ratio within the shear band and deviator stress ratio tend to exhibit consistently for the same specimen with different initial physical states,thereby distinguishing the critical state.There is a significantly higher change in void ratio within the shear band compared to outside of it,yet it remains stable within a relatively similar range.Additionally,the invariant of the fabric tensor used to describe the critical state characteristics also demonstrates a high degree of consistency within the shear band.These findings strongly indicate that the critical state exists within the shear failure surfaceand is highly likely to beunique.展开更多
The 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)-induced parkinsonism model, particularly in non-human primates, remains the gold-standard for studying the pathogenesis and assessing novel therapies for Parki...The 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)-induced parkinsonism model, particularly in non-human primates, remains the gold-standard for studying the pathogenesis and assessing novel therapies for Parkinson's disease. However, whether the loss of dopaminergic neurons in this model is progressive remains controversial, mostly due to the lack of objective in vivo assessment of changes in the integrity of these neurons. In the present study, parkinsonism was induced in cynomolgus monkeys by intravenous administration of MPTP (0.2 mg/kg) for 15 days; stable parkinsonism developed over 90 days, when the symptoms were stable. Noninvasive positron emission tomographic neuroimaging of vesicular monoamine transporter 2 with 9-[18F] fluoropropyl-(+)-dihydrotetrabenazine ([18F]AV-133) was used before, and 15 and 90 days after the beginning of acute MPTP treatment. The imaging showed evident progressive loss of striatal uptake of [18SF]AV-133. The dopaminergic denervation severity had a significant linear correlation with the clinical rating scores and the bradykinesia subscores. These findings demonstrated that [18F]AV-133 PET imaging is a useful tool to noninvasively evaluate the evolution of monoaminergic terminal loss in a monkey model of MPTP-induced parkinsonism.展开更多
This paper examines the architectural and Landscape design strategies and intentions for green, open spaces facilities targeting stress aLLeviation for learning environments such as those of university campuses in a c...This paper examines the architectural and Landscape design strategies and intentions for green, open spaces facilities targeting stress aLLeviation for learning environments such as those of university campuses in a compact urban setting. Literature reviews provide three prevailing perspectives for physical design pedagogical operatives: healing gardens where greenery and plants produce restorative effects; flexible spaces that accommodate functional needs of different activities; and green buildings that incorporate open space as a catalyst for integrated eco-system. Corresponding design approaches (Landscape design, spatial design and green design) are scrutinized by case study. A comparison of two university campuses with different urban contexts is conducted to identify challenges and opportunities for applying these design approaches. For a compact campus, high-dense surroundings may limit the size of an open space and may handicap circulation and accessibility; on the other side, a small open space may provide its users more intimate contact with natural restorative elements and also a more controllable microclimate for physical comfort. A healthy campus should encompass diverse open spaces to satisfy different purposes. Finally, a framework that integrates the three approaches is combined to produce a sustainable design rubric.展开更多
Although CRISPR/Cas9 has been widely used to generate knockout mice, two major limitations remain:the founders usually carry a mixture of genotypes, and mosaicism harboring multiple genotypes.Therefore, it takes a lon...Although CRISPR/Cas9 has been widely used to generate knockout mice, two major limitations remain:the founders usually carry a mixture of genotypes, and mosaicism harboring multiple genotypes.Therefore, it takes a long time to get homozygous mutants. Recently developed base editing(BE) system,which introduces C-to-T conversion without double strand DNA cleavage, has been used to introduce artificial stop codons(i-STOP) to prematurely terminate translation, providing a cleaner strategy for genome engineering. Using this strategy, we generated CD160 KO and VISTA/CD160 double KO mice by microinjection of a single sg RNA targeting CD160 and a mixture of sg RNAs targeting VISTA and CD160,respectively. The BE system induced STOP efficiently in mouse embryos and consequently in founder mice without detectable off-target. Most interestingly, the majority of the mutants harbor same genetic modifications, indicating we generated isogenic single and multiplex gene mutant mice by BE-induced STOP. We also obtained homozygous mutant mouse in F1 mice, demonstrating the accelerated strategy in generating animal models.展开更多
Light-triggered drug delivery system is an effective strategy for precise diagnosis and therapy in cancer treatment. However, it suffers from difficultly balancing the dosimetry of drug with light dose and a lack of i...Light-triggered drug delivery system is an effective strategy for precise diagnosis and therapy in cancer treatment. However, it suffers from difficultly balancing the dosimetry of drug with light dose and a lack of in vivo models for validating their clinical benefits. Here we report an unprecedented near-infrared(NIR) light photocaged cyanine-based prodrug Cy-CPT-Biotin with dual-channel fluorescence mode, enabling NIR light to precisely regulate where, when and how the intact and active prodrugs are delivered. The synergy of photochemical reaction and modulation in π-conjugated polyene backbone of cyanine can fully perform distinct dual-channel fluorescence changes in a NIR light-mediated manner. The prodrug has striking characteristics of excellent tumor-targeting ability, real-time monitoring of the in vivo behaviors by dual-channel mode and NIR-light triggering,especially for achieving fine regulation and on-demand drug release in the precise dosimetry of drug with light dose in living animals. This optical orthogonality strategy that conjuncts with NIR light-triggered and dual-channel fluorescence in vivo imaging provides a powerful tool for in vivo real-time tracking and finely tuning the prodrug release for precise drug delivery.展开更多
When orthopedic joints coated by hydroxyapatite(HA) were implanted in the human body, they release wear debris into the surrounding tissues. The generation and accumulation of wear particles will induce aseptic loosen...When orthopedic joints coated by hydroxyapatite(HA) were implanted in the human body, they release wear debris into the surrounding tissues. The generation and accumulation of wear particles will induce aseptic loosening. However, the potential bioeffect and mechanism of HA-coated orthopedic implants on bone cells are poorly understood. In this study, defect-related luminescent bur-like hydroxyapatite(BHA) microspheres with the average diameter of 7–9 μm which are comparable to that of the wear-debris particles from aseptically loosened HA implants or HA debris have been synthesized by hydrothermal synthesis and the MC3 T3-E1 cells were set as a cells model to study the potential bioeffect and mechanism of BHA microspheres. The studies demonstrated that BHA microspheres could be taken into MC3 T3-E1 cells via endocytosis involved in micropinocytosisand clathrin-mediated endocytosis process, and exert cytotoxicity effect. BHA microspheres could induce the cell apoptosis by intracellular production of reactive oxygen species(ROS), which led to not only an increase in the permeability of lysosome and release of cathepsins B, but also mitochondrial dysfunction and DNA damage. Our results provide novel evidence to elucidate their toxicity mechanisms and might be helpful for more reasonable applications of HA-based orthopaedic implants in the future.展开更多
Dear Editor,Newly discovered characteristics like"collateral effect"or trans-cleavage in CRISPR-Cas13 and CRISPR-Cas12 systems have enabled their usage in nucleic acid detection(Gootenberg et al.2017,2018;Ch...Dear Editor,Newly discovered characteristics like"collateral effect"or trans-cleavage in CRISPR-Cas13 and CRISPR-Cas12 systems have enabled their usage in nucleic acid detection(Gootenberg et al.2017,2018;Chen et al.2018).The collateral RNA cleavage of Cas13a has been reported to be harmful for cell development(Wang et al.2019;Buchman et al.2020).As a representative gene editor of CRISPR-Cas12 system,CRISPR-Cas12a(Cpf1)holds great potential for therapeutic applications in the future(Zetsche et al.2015;Koo et al.2018;Campa et al.2019).展开更多
基金funded by the Second Tibetan Plateau Scientific Expedition and Research Program[grant numbers 2019QZKK0105 and 2019QZKK0103]the National Natural Science Foundation of China[grant number 41975009].
文摘The Second Tibetan Plateau Scientific Expedition and Research Program tasked a research team with the“Investigation of the water vapor channel of the Yarlung Zsangbo Grand Canyon(INVC)”in the southeastern Tibetan Plateau(TP).This paper summarizes the scientific achievements obtained from the data collected by the INVC observation network and highlights the progress in investigating the development of heavy rainfall events associated with water vapor changes.The rain gauge network of the INVC can represent the impacts of the Yarlung Zsangbo Grand Canyon(YGC)topography on precipitation at the hourly scale.The microphysical characteristics of the precipitation in the YGC are different than those in the lowland area.The GPM-IMERG(Integrated MultisatellitE Retrievals for Global Precipitation Measurement)satellite precipitation data for the YGC region should be calibrated before they are used.The meridional water vapor flux through the YGC is more important than the zonal flux for the precipitation over the southeastern TP.The decreased precipitation around the YGC region is partly due to the decreased meridional water vapor flux passing through the YGC.High-resolution numerical models can benefit precipitation forecasting in this region by using a combination of specific schemes that capture the valley wind and water vapor flux along the valley floor.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant Nos.2019QZKK0103 and 2019QZKK0105)the National Natural Science Foundation of China(Grant Nos.41975009,42230610,41840650 and U2242208)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Wang Binbin,2022069).
文摘Ground-based microwave radiometers(MWRs)operating in the K-and V-bands(20–60 GHz)can help us obtain temperature and humidity profiles in the troposphere.Aside from some soundings from local meteorological observatories,the tropospheric atmosphere over the Tibetan Plateau(TP)has never been continuously observed.As part of the Chinese Second Tibetan Plateau Scientific Expedition and Research Program(STEP),the Tibetan Plateau Atmospheric Profile(TPPROFILE)project aims to construct a comprehensive MWR troposphere observation network to study the synoptic processes and environmental changes on the TP.This initiative has collected three years of data from the MWR network.This paper introduces the data information,the data quality,and data downloading.Some applications of the data obtained from these MWRs were also demonstrated.Our comparisons of MWR against the nearest radiosonde observation demonstrate that the TP-PROFILE MWR system is adequate for monitoring the thermal and moisture variability of the troposphere over the TP.The continuous temperature and moisture profiles derived from the MWR data provide a unique perspective on the evolution of the thermodynamic structure associated with the heating of the TP.The TP-PROFILE project reveals that the low-temporal resolution instruments are prone to large uncertainties in their vapor estimation in the mountain valleys on the TP.
基金supported by the National Natural Science Foundation of China(Grant No.U23A20204)the“Wanjiang Scholar Program(Anhui Province)”.
文摘Tomato(Solanum lycopersicum)is a perishable fruit because of its fast water loss and susceptibility to pathogens in the post-harvest stage,which leads to huge economic losses every year.In this study,firstly from 19 tomato cultivars,we screened out two cultivars,Riogrand and SalarF1,having long and short shelf-life spans,respectively.Secondly,shelf-life analysis was carried out for both cultivars at room temperature.Results exhibited that Riogrand showed higher firmness and less weight loss than SalarF1.The ethylene production was higher in SalarF1,compared with Riogrand during post-harvest storages.We performed transcriptomic analysis of both cultivars in different storage stages.We discovered 2913,2188,and 11,119 differentially expressed genes(DEGs)for three post-harvest stages(0,20,and 40 Days Post-Harvest(DPH)),respectively.These genes are enriched in ethylene biosynthesis and response,as well as cell wall-related genes.Ethylene response factor(ERF)ERF2 and ERF4 were highly expressed in SalarF1 with a short shelf life in 40 DPH,and the ethylene biosynthetic genes ACO1,ACO4,ACS6,and ACS2 were significantly upregulated in SalarF1.Regarding cell wall loosening and cell wall-related genes XTH3,XTH7,XTH23,1,3;1,4-β-D-Gluc-like,pGlcT1,Cellulase,PGH1,PL5,PL-like 1,PL-like 2 exhibited the highest levels of significance,being notably upregulated in the last stage of SalarF1.The quantitative real-time polymerase chain reaction(qRT-PCR)analysis validated these gene expressions,which is in line with the transcriptome analysis.The findings suggested that the extension of tomato fruit shelf life is mostly dependent on ethylene biosynthesis,signaling pathway genes,cell wall loosening,and cell wall-associated genes.
基金financial support of the National Natural Science Foundation of China (21875185)。
文摘Geminal dinitropropyl ester plasticizers(DNPEPs) possess excellent energetic performances which provide good potentials as insensitive plasticizer. In this study, we design and synthesize DNPEPs with different alkane chain parts, and systematically investigate their structure-property relationships.Results show that DNPEPs have impact sensitivities all higher than 25.2 J, thermal decomposition temperatures all higher than 254 ℃, and glass transition temperatures(T_(g)) lower than-90 ℃.Furthermore, the effects of DNPEPs as plasticizer are studied on hydroxyl terminated polybutadiene(HTPB) in detail, including the viscosity, glass transition temperatures and others. It is noteworthy that 2,2-dinitropropyl nonanoate(DNPNc) among these DNPEPs exhibits the most expected simultaneous tuning effects on both viscosity and T_(g) of HTPB systems, providing favorable potentials to replace the conventional plastizers as dioctyl sebacate(DOS) in the HTPB based propellants and explosives.
文摘It has been long recognized that a variety of anthropogenic activities may cause earthquakes(Ellsworth et al.,2013;Yang HF et al.,2017).In the recent decades,induced earthquakes have been found in many settings and become a growing concern,in particular for regions that are undergoing with resource development.
基金supported by the National Science Library of the Chinese Acedemy of Sciencesthe Bureau of Development and Planning of the Chinese Academy of Sciences
文摘Purpose: This study explores new content, forms, and fields of science and technology(S&T;) innovation and entrepreneurship information services of the National Science Library of the Chinese Academy of Sciences(NSLC).Design/methodology/approach: We cooperated with incubator enterprises and set up an "S&T; Innovation and Entrepreneurship Information Service Platform." We designed five series of activities, including industrial information release, project financing and roadshows, entrepreneurial sharing, entrepreneurial coaching sessions, and entrepreneurial salons. Based on the implementation of these activities, we designed new NSLC library services for S&T; innovation and entrepreneurship.Findings: Since the construction of the platform, these five series of activities have attracted more than 80 business projects, 90 investors, and 30 researchers. Furthermore, more than 20 media representatives and nearly 300 entrepreneurs have participated in the activities that the NSLC has organized in the past two years. Through these activities, we have defined an S&T; innovation and entrepreneurship knowledge service model for the NSLC.Research limitations: The service practice of the NSLC is still in the demonstration phase. Due to staffing limitations of our service teams, the expansion of our service activities has been greatly restricted.Practical implications: The innovation and entrepreneurship information services of the NSLC provide a lot of material for transformation of library services for domestic and foreign special libraries.Originality/value: It is useful to transform library and business services by embedding them into ways in which we serve innovation and entrepreneurial activities. This opens up a new field of library knowledge services in China.
基金supported by the National Science Library of the Chinese Academy of Sciences(Grant No.:Y130181001)
文摘Purpose: This study aims to establish a new framework for evaluating science and technology (S&T) competitiveness that is appropriate to meet the needs of provincial academies of sciences (PASs) in China.Design/methodology/approaches: An evaluation index, including such assessing indicators as research strength, research impact, research development and trends, and regional contributions, is developed for China's PASs. Taking the Jiangxi Academy of Sciences (JXAS) as an example, we first explain how to apply this framework to analyze the strengths and weaknesses of PASs in China. Then, we compare the results of all 17 PASs in order to get a comprehensive understanding of their competitiveness.Findings: Our results show the development path, current status, innovation advantages, and weaknesses of JXAS very clearly. Based on our comparative analysis, we ranked the 17 PASs from the perspective of different dimensions, by which their competitiveness strengths and weaknesses can be highlighted for improvement.Research limitations: In this analysis, we did not take S&T policies, S&T systems, or historical factors into consideration. Thus, we may have ignored the influence of the soft individual differences of different PASs in China..Practical implications: The evaluation index developed in this paper provides a useful insight into an analytical method that can be used by PASs or other provincial research institutions (PRIs) to assess their competitiveness.Originality/value: Compared with existing evaluation frameworks, our method has two main characteristics: First, we added three new dimensions, including the PASs' applicable research outputs, regional contributions, and comparative advantages; second, we conducted a comparative analysis of local research institutes in their different advantaged industrial areas, which makes our analytical method more comprehensive for local research institutions.
基金supported by the Chinese Academy of Sciences(Grant No.Y11006)
文摘Purpose:As scientific resources are widely distributed,researchers often have difficulties in acquiring information from different individual sources.This paper intends to present a new approach to construct a subject-knowledge-based integration platform which was carried out by the Institute of Software,Chinese Academy of Sciences(ISCAS).Our aim is to use technique tools to strengthen the library service by combining a variety of information service resources with knowledge tools.Design/methodology/approach:Based on the analysis of users’ needs,we established a collaborative team across ISCAS Library,National Science Library of CAS(NSL CAS),and ISCAS’ research groups or research labs.With the service tools developed by ISCAS Library,we embedded other multipurpose utility tools of knowledge integration into the platform as to make full use of software tools in knowledge integration,knowledge fusion,and intelligent push of library services to end users.Findings:With a hard effort of the construction team,the ISCAS subject group platform(hereinafter as ISCAS Platform) has integrated such information resources as institutional repository(IR) of ISCAS,open resources from websites and subject resources of computer sciences.Up to date,ISCAS platform can provide integrated information services including data collection for computer science and intelligent generation of citation reports,by means of embedding self-developed discovering tools for domain experts and subject content,and generation tools for scientific citation reports.Research limitations:Knowledge organization need be further improved in the ISCAS subject group platform.In addition,functions for academic exchanges need be maximized as to meet the individual demands of researchers for library services at the Platform.Practical implications:Since we Platform has been put into use through the Library website of the ISCAS in June 2012,many academic libraries from both domestic universities and CAS institutes have showed their strong interest for our self-developed tools,among which more than 10 cooperation partnerships have been formed.Originality/value:Through self-developed service tools and the integration of multiple-type resources,our Platform has solved such key problems as timely access and update of the trusted resources from a third party,and the rapid fusion and extension of library resources while establishing subject knowledge environment.So the ISCAS library can provide a flexible customization of library services according to the need of different users.
基金supported by the National Natural Science Foundation of China (general program) (grant Nos.52178361,42407214)the National Outstanding Youth Science Fund Project of the National Natural Science Foundation of China (grant No.51722801).
文摘An explanation of the meso-mechanism of sand granular materials for the uniqueness of critical state is presented by means of the discrete element method(DEM)under flexible boundary loading conditions.A series triaxial drainage shear test(DEM simulations),in conjunction with the flexible boundary technique,of were performed for sand samples subjected to various physical states and with different particle size distributions.After carefully investigating the critical status of the results of the numerical calculation,the macroscopic failure modes and shear band evolution of sand,as well as the velocity vector field due to different initial states,were explored and classified.Furthermore,the evaluation rules and discrepancies between overall void ratios of the specimen and local void ratios within the shear band under the critical state were recorded and analyzed.The results proved that a sample with a small void tends to form a shear band,and the rotation of the particles in the non-shear zone is negligible.Conversely,sandy soil with large initial void ratios exhibited limited development of significant shear bands,and the change in void ratios within the shear region and the non-shear area are not significant.Interestingly,the particle-size distribution exerts minimal influence on the evolution rule which the void ratio converges within the shear band and diverges outside the shear region for both multi-stage and single-stage specimens.The void ratio within the shear band and deviator stress ratio tend to exhibit consistently for the same specimen with different initial physical states,thereby distinguishing the critical state.There is a significantly higher change in void ratio within the shear band compared to outside of it,yet it remains stable within a relatively similar range.Additionally,the invariant of the fabric tensor used to describe the critical state characteristics also demonstrates a high degree of consistency within the shear band.These findings strongly indicate that the critical state exists within the shear failure surfaceand is highly likely to beunique.
基金supported by grants from the Ministry of Science and Technology of China (2012AA02A514, 2011CB504101)a Science Research and Technology Development Project from the Bureau of Science and Technology of Nanning, China (201001010A)+2 种基金the China Postdoctoral Science Foundation (20110490452)the Beijing Postdoctoral Research Activity Foundation (2011ZZ-07)the Open Fund for the Key Laboratory on Neurodegenerative Disease of the Ministry of Education (2012SJBX01)
文摘The 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)-induced parkinsonism model, particularly in non-human primates, remains the gold-standard for studying the pathogenesis and assessing novel therapies for Parkinson's disease. However, whether the loss of dopaminergic neurons in this model is progressive remains controversial, mostly due to the lack of objective in vivo assessment of changes in the integrity of these neurons. In the present study, parkinsonism was induced in cynomolgus monkeys by intravenous administration of MPTP (0.2 mg/kg) for 15 days; stable parkinsonism developed over 90 days, when the symptoms were stable. Noninvasive positron emission tomographic neuroimaging of vesicular monoamine transporter 2 with 9-[18F] fluoropropyl-(+)-dihydrotetrabenazine ([18F]AV-133) was used before, and 15 and 90 days after the beginning of acute MPTP treatment. The imaging showed evident progressive loss of striatal uptake of [18SF]AV-133. The dopaminergic denervation severity had a significant linear correlation with the clinical rating scores and the bradykinesia subscores. These findings demonstrated that [18F]AV-133 PET imaging is a useful tool to noninvasively evaluate the evolution of monoaminergic terminal loss in a monkey model of MPTP-induced parkinsonism.
文摘This paper examines the architectural and Landscape design strategies and intentions for green, open spaces facilities targeting stress aLLeviation for learning environments such as those of university campuses in a compact urban setting. Literature reviews provide three prevailing perspectives for physical design pedagogical operatives: healing gardens where greenery and plants produce restorative effects; flexible spaces that accommodate functional needs of different activities; and green buildings that incorporate open space as a catalyst for integrated eco-system. Corresponding design approaches (Landscape design, spatial design and green design) are scrutinized by case study. A comparison of two university campuses with different urban contexts is conducted to identify challenges and opportunities for applying these design approaches. For a compact campus, high-dense surroundings may limit the size of an open space and may handicap circulation and accessibility; on the other side, a small open space may provide its users more intimate contact with natural restorative elements and also a more controllable microclimate for physical comfort. A healthy campus should encompass diverse open spaces to satisfy different purposes. Finally, a framework that integrates the three approaches is combined to produce a sustainable design rubric.
基金supported by the National Key R&D Program(2016YFC0905901 to X.H.,2016YFA0503300 to X.G.)the NSFC(81771641 to X.G.)+1 种基金Fok Ying Tung Education Foundation(161037 to X.G.)Local Grants(17JC1420103 to X.H.,SKLRM-K201502 to X.G.)
文摘Although CRISPR/Cas9 has been widely used to generate knockout mice, two major limitations remain:the founders usually carry a mixture of genotypes, and mosaicism harboring multiple genotypes.Therefore, it takes a long time to get homozygous mutants. Recently developed base editing(BE) system,which introduces C-to-T conversion without double strand DNA cleavage, has been used to introduce artificial stop codons(i-STOP) to prematurely terminate translation, providing a cleaner strategy for genome engineering. Using this strategy, we generated CD160 KO and VISTA/CD160 double KO mice by microinjection of a single sg RNA targeting CD160 and a mixture of sg RNAs targeting VISTA and CD160,respectively. The BE system induced STOP efficiently in mouse embryos and consequently in founder mice without detectable off-target. Most interestingly, the majority of the mutants harbor same genetic modifications, indicating we generated isogenic single and multiplex gene mutant mice by BE-induced STOP. We also obtained homozygous mutant mouse in F1 mice, demonstrating the accelerated strategy in generating animal models.
基金supported by The National Natural Science Foundation of China (21788102, 21421004, 21636002, 21622602)National Key Research and Development Program (2016YFA0200300)+2 种基金Scientific Committee of Shanghai (14ZR1409700, 15XD1501400)Fok Ying Tong Education Foundation (142014)Program of Introducing Talents of Discipline to Universities (B16017)
文摘Light-triggered drug delivery system is an effective strategy for precise diagnosis and therapy in cancer treatment. However, it suffers from difficultly balancing the dosimetry of drug with light dose and a lack of in vivo models for validating their clinical benefits. Here we report an unprecedented near-infrared(NIR) light photocaged cyanine-based prodrug Cy-CPT-Biotin with dual-channel fluorescence mode, enabling NIR light to precisely regulate where, when and how the intact and active prodrugs are delivered. The synergy of photochemical reaction and modulation in π-conjugated polyene backbone of cyanine can fully perform distinct dual-channel fluorescence changes in a NIR light-mediated manner. The prodrug has striking characteristics of excellent tumor-targeting ability, real-time monitoring of the in vivo behaviors by dual-channel mode and NIR-light triggering,especially for achieving fine regulation and on-demand drug release in the precise dosimetry of drug with light dose in living animals. This optical orthogonality strategy that conjuncts with NIR light-triggered and dual-channel fluorescence in vivo imaging provides a powerful tool for in vivo real-time tracking and finely tuning the prodrug release for precise drug delivery.
基金supported by the National Natural Science Foundation of China (21301046, 51302062)the Natural Science Foundation of Hebei Province (B2017201125, B2017201100)+1 种基金the Second Batch of Top Youth Talent Support Program of Hebei ProvinceDistinguished Young Scholars Fund of Hebei University (2015JQ04)
文摘When orthopedic joints coated by hydroxyapatite(HA) were implanted in the human body, they release wear debris into the surrounding tissues. The generation and accumulation of wear particles will induce aseptic loosening. However, the potential bioeffect and mechanism of HA-coated orthopedic implants on bone cells are poorly understood. In this study, defect-related luminescent bur-like hydroxyapatite(BHA) microspheres with the average diameter of 7–9 μm which are comparable to that of the wear-debris particles from aseptically loosened HA implants or HA debris have been synthesized by hydrothermal synthesis and the MC3 T3-E1 cells were set as a cells model to study the potential bioeffect and mechanism of BHA microspheres. The studies demonstrated that BHA microspheres could be taken into MC3 T3-E1 cells via endocytosis involved in micropinocytosisand clathrin-mediated endocytosis process, and exert cytotoxicity effect. BHA microspheres could induce the cell apoptosis by intracellular production of reactive oxygen species(ROS), which led to not only an increase in the permeability of lysosome and release of cathepsins B, but also mitochondrial dysfunction and DNA damage. Our results provide novel evidence to elucidate their toxicity mechanisms and might be helpful for more reasonable applications of HA-based orthopaedic implants in the future.
基金This study was supported by the R&D Program of China(2018YFC2000100 and 2017YFC1001300)the CAS Strategic Priority Research Program(XDB32060000)+3 种基金the National Natural Science Foundation of China(31871502,31925016,91957122,31901047)the Basic Frontier Scientific Research Program of Chinese Academy of Sciences From 0 to 1 Original Innovation Project(ZDBS-LY-SM001)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX05),the Shanghai City Committee of science and Technology Project(18411953700,18JC1410100,19XD1424400,19YF1455100)the International Partnership Program of Chinese Academy of Sciences(153D31KYSB20170059).
文摘Dear Editor,Newly discovered characteristics like"collateral effect"or trans-cleavage in CRISPR-Cas13 and CRISPR-Cas12 systems have enabled their usage in nucleic acid detection(Gootenberg et al.2017,2018;Chen et al.2018).The collateral RNA cleavage of Cas13a has been reported to be harmful for cell development(Wang et al.2019;Buchman et al.2020).As a representative gene editor of CRISPR-Cas12 system,CRISPR-Cas12a(Cpf1)holds great potential for therapeutic applications in the future(Zetsche et al.2015;Koo et al.2018;Campa et al.2019).