This study delves into the intricate relationship between iron(Fe)content in kaolinite and its impact on the adsorption behavior of sodium oleate.The effects of different iron concentrations on adsorption energy,hydro...This study delves into the intricate relationship between iron(Fe)content in kaolinite and its impact on the adsorption behavior of sodium oleate.The effects of different iron concentrations on adsorption energy,hydrogen bond kinetics and adsorption efficiency were studied through simulation and experimental verification.The results show that the presence of iron in the kaolinite structure significantly improves the adsorption capacity of sodium oleate.Kaolinite samples with high iron content have better adsorption properties,lower adsorption energy levels and shorter and stronger hydrogen bonds than pure kaolinite.The optimal concentration of oleic acid ions for achieving maximum adsorption efficiency was identified as 1.2 mmol/L across different kaolinite samples.At this concentration,the adsorption rates and capacities reach their peak,with Fe-enriched kaolinite samples exhibiting notably higher flotation recovery rates.This optimal concentration represents a balance between sufficient oleic acid ion availability for surface interactions and the prevention of self-aggregation phenomena that could hinder adsorption.This study offers promising avenues for optimizing the flotation process in mineral processing applications.展开更多
Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.H...Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.展开更多
Pressure is one of the necessary conditions for diamond growth.Exploring the influence of pressure on growth changes in silicon-doped diamonds is of great value for the production of high-quality diamonds.This work re...Pressure is one of the necessary conditions for diamond growth.Exploring the influence of pressure on growth changes in silicon-doped diamonds is of great value for the production of high-quality diamonds.This work reports the morphology,impurity content and crystal quality characteristics of silicon-doped diamond crystals synthesized under different pressures.Fourier transform infrared spectroscopy shows that with the increase of pressure,the nitrogen content in the C-center inside the diamond crystal decreases.X-ray photoelectron spectroscopy test results show the presence of silicon in the diamond crystals synthesized by adding silicon powder.Raman spectroscopy data shows that the increase in pressure in the Fe-Ni-C-Si system shifts the Raman peak of diamonds from 1331.18 cm^(-1)to 1331.25 cm^(-1),resulting in a decrease in internal stress in the crystal.The half-peak width decreased from 5.41 cm^(-1)to 5.26 cm^(-1),and the crystallinity of the silicon-doped diamond crystals improved,resulting in improved quality.This work provides valuable data that can provide a reference for the synthesis of high-quality silicon-doped diamonds.展开更多
Oxygen evolution reaction(OER)in acid media has been intensively studied recently for its important role in proton exchange membrane electrolyzers.CeO_(2)-based nanomaterials have been widely used in various applicati...Oxygen evolution reaction(OER)in acid media has been intensively studied recently for its important role in proton exchange membrane electrolyzers.CeO_(2)-based nanomaterials have been widely used in various applications for their redox properties,oxygen vacancy,and surface activity.CeO_(2)-based nanocatalysts also exhibit superior catalytic performance in OER in acid media.Herein,we fabricated a highly effi cient catalytic interface between IrO x and CeO_(2)(IrO x/CeO_(2)),which showed a boosting OER activity with an overpotential of 217 mV at the current density of 10 mA/cm 2 and long-term stability for 10 h in 0.5 mol/L H_(2)SO_(4),which were better than those of many reported catalysts.The in situ diff erential electrochemical mass spectrometry results demonstrated that IrO x/CeO_(2)and the commercial IrO 2(IrO 2-com)followed the adsorbate evolution mechanism,whereas the pure CeO_(2)surface followed the lattice oxygen oxidation mechanism under the same conditions for OER.These indicated that the interface of IrO x and CeO_(2)improved mass transfer effi ciency and reactivity,which also prevented the lattice oxygen evolution in the CeO_(2)structure and protected the whole structure.This work fi nds a new way for OER in acid media catalyzed by CeO_(2)-based nanocatalysts and promotes the design strategy for other CeO_(2)-based nanostructures.展开更多
This paper stems from an artistic experiment,in which a distinguished violinist received completely different prices for performing in varying locations.This may be due to the difference in the performance locations,a...This paper stems from an artistic experiment,in which a distinguished violinist received completely different prices for performing in varying locations.This may be due to the difference in the performance locations,and the value of art in the heart of the audience.展开更多
The performance of the flexibility and stretchability of flexible electronics depends on the mechanical structure design,for which a great progress has been made in past years.The use of prestrain in the substrate,cau...The performance of the flexibility and stretchability of flexible electronics depends on the mechanical structure design,for which a great progress has been made in past years.The use of prestrain in the substrate,causing the compression of the transferred interconnects,can provide high elastic stretchability.Recently,the nonbuckling interconnects have been designed,where thick bar replaces thin ribbon layout to yield scissor-like in-plane deformation instead of in-or out-of-plane buckling modes.The nonbuckling interconnect design achieves significantly enhanced stretchability.However,combined use of prestrain and nonbuckling interconnects has not been explored.This paper aims to study the mechanical behavior of nonbuckling interconnects bonded to the prestrained substrate analytically and numerically.It is found that larger prestrain,longer straight segment,and smaller arc radius yield smaller strain in the interconnects.On the other hand,larger prestrain can also cause larger strain in the interconnects after releasing the prestrain.Therefore,the optimization of the prestrain needs to be found to achieve favorable stretchability.展开更多
[Objectives]A method for the determination ofβ-sitosterol in Plumbago zeylanica L.was established and the content ofβ-sitosterol in different medicinal parts,different producing areas and different harvest periods w...[Objectives]A method for the determination ofβ-sitosterol in Plumbago zeylanica L.was established and the content ofβ-sitosterol in different medicinal parts,different producing areas and different harvest periods were compared.[Methods]High performance liquid chromatography(HPLC)-evaporative light scattering detector assay was used.The chromatographic column was Kromasil C_(18) column(250 mm×4.6 mm,5μm);the mobile phase was pure methanol;the flow rate was 1.0 mL/min;the column temperature was 30℃.The detection parameters of evaporative light scattering detector were as follows:drift tube temperature was 40℃,carrier gas(N_(2))pressure was 3.5 bar.[Results]There was a good linear relationship betweenβ-sitosterol(1.080-4.860μg)and the natural logarithm of peak area(r=0.9995).The average recovery rate was 99.80%.The content ofβ-sitosterol in root and stem was 0.2074 and 0.4064 mg/g,respectively,but it was not found in leaves;the content ofβ-sitosterol in P.zeylanica L.in Guangxi was generally lower than that in Yunnan,and the content ofβ-sitosterol in P.zeylanica L.in Xishuangbanna was the highest;the content ofβ-sitosterol in the stem of P.zeylanica L.was stable at a relatively high level in different harvest periods.[Conclusions]The method is simple,accurate and reproducible,and can be used as one of the methods to control the quality of P.zeylanica L.展开更多
In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phospho...In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phosphorus,and 10 indicators including root phenotype,phosphorus utilization efficiency at the seedling stage and yield were measured.Through single-index cluster analysis,the performance value and relative value of the abovementioned indexes under low-phosphorus conditions were analyzed,and then,the combined indexes were analyzed by principal components method.The membership function method and the cluster analysis method was used to calculate and analyze the comprehensive score value.Three indexes of root P utilization efficiency(X_(1)),relative value of root P utilization efficiency(X_(2)),and root volume(X_(3))under low P at the seedling stage were selected as the most consistent with the yield screening results under low P condition,and the mathematical model of the comprehensive score value was obtained:D=1.218X_(1)t 0.320X_(2)t 0.007X_(3)-0.664(P=0.000,R^(2)=1.000).The comprehensive score can screen and identify the P efficiency of soybeans with fewer indexes in the early growth stages,which provides a more rapid and reliable mathematical model for screening and identifying a larger number of germplasm resources for P efficiency.展开更多
With the rapid development of globalization,the industries of various countries are actively seeking the best way to improve the global value chain(GVC)status while integrating into the world.As an important factor af...With the rapid development of globalization,the industries of various countries are actively seeking the best way to improve the global value chain(GVC)status while integrating into the world.As an important factor affecting the GVC status,foreign direct investment(FDI)has attracted extensive attention from scholars.On the basis of systematically summarizing the research progress of FDI theory,GVC status and the influence of FDI on GVC status,the paper tries to clarify the internal relationship between FDI and GVC status,explores the shortcomings of existing research,and puts forward the possible direction of future research.展开更多
With the development of teaching Chinese as a foreign language, the teaching level of teachers of Chinese as a foreign language is constantly improving. Teachers of Chinese as a foreign language are the messengers of ...With the development of teaching Chinese as a foreign language, the teaching level of teachers of Chinese as a foreign language is constantly improving. Teachers of Chinese as a foreign language are the messengers of Chinese culture and represent the image of China. Therefore, the quality of teaching Chinese as a foreign language teachers plays a vital role in the quality of teaching Chinese as a foreign language. Immersion teaching method is a relatively successful teaching method in the field of foreign bilingual teaching. It opens a new door for teaching Chinese as a foreign language and plays an important role in improving students' ability to use Chinese. This paper comprehensively evaluates the teaching of Chinese as a whole based on immersive teaching, and calculates the data after evaluation of the evaluation index system to ensure the scientific and accurate evaluation results. Finally, it is proposed that the countermeasures should be improved from the three aspects of classroom teaching, the quality of Chinese teachers and the overall quality of the team of Chinese as a foreign language.展开更多
Salicylic acid(SA)plays a pivotal role in plant response to biotic and abiotic stress.Several core SA signaling regulators and key proteins in SA biosynthesis have been well characterized.However,much remains unknown ...Salicylic acid(SA)plays a pivotal role in plant response to biotic and abiotic stress.Several core SA signaling regulators and key proteins in SA biosynthesis have been well characterized.However,much remains unknown about the origin,evolution,and early diversification of core elements in plant SA signaling and biosynthesis.In this study,we identified 10 core protein families in SA signaling and biosynthesis across green plant lineages.We found that the key SA signaling receptors,the nonexpresser of pathogenesis-related(NPR)proteins,originated in the most recent common ancestor(MRCA)of land plants and formed divergent groups in the ancestor of seed plants.However,key transcription factors for SA signaling,TGACG motif-binding proteins(TGAs),originated in the MRCA of streptophytes,arguing for the stepwise evolution of core SA signaling in plants.Different from the assembly of the core SA signaling pathway in the ancestor of seed plants,SA exists extensively in green plants,including chlorophytes and streptophyte algae.However,the full isochorismate synthase(ICS)-based SA synthesis pathway was first assembled in the MRCA of land plants.We further revealed that the ancient abnormal inflorescence meristem 1(AIM1)-basedβ-oxidation pathway is crucial for the biosynthesis of SA in chlorophyte algae,and this biosynthesis pathway may have facilitated the adaptation of early-diverging green algae to the high-light-intensity environment on land.Taken together,our findings provide significant insights into the early evolution and diversification of plant SA signaling and biosynthesis pathways,highlighting a crucial role of SA in stress tolerance during plant terrestrialization.展开更多
Untethered microrobots can be used for cargo delivery(e.g.,drug molecules,stem cells,and genes)targeting designated areas.However,it is not enough to just reach the lesion site,as some drugs can only play the best the...Untethered microrobots can be used for cargo delivery(e.g.,drug molecules,stem cells,and genes)targeting designated areas.However,it is not enough to just reach the lesion site,as some drugs can only play the best therapeutic effect within the cells.To this end,folic acid(FA)was introduced into microrobots in this work as a key to mediate endocytosis of drugs into cells.The microrobots here were fabricated with biodegradable gelatin methacryloyl(GelMA)and modified with magnetic metal-organic framework(MOF).The porous structure of MOF and the hydrogel network of polymerized GelMA were used for the loading of enough FA and anticancer drug doxorubicin(DOX)respectively.Utilizing the magnetic property of magnetic MOF,these microrobots can gather around the lesion site with the navigation of magnetic fields.The combination effects of FA targeting and magnetic navigation substantially improve the anticancer efficiency of these microrobots.The result shows that the cancer cells inhibition rate of microrobots with FA can be up to 93%,while that of the ones without FA was only 78%.The introduction of FA is a useful method to improve the drug transportation ability of microrobots,providing a meaningful reference for further research.展开更多
An expression quantitative trait locus (eQTL) is a chromosomal region where genetic variants are associated with the expression levels of specific genes that can be both nearby or distant. The identifications of eQTLs...An expression quantitative trait locus (eQTL) is a chromosomal region where genetic variants are associated with the expression levels of specific genes that can be both nearby or distant. The identifications of eQTLs for different tissues, cell types, and contexts have led to a better understanding of the dynamic regulations of gene expressions and implications of functional genes and variants for complex traits and diseases. Although most eQTL studies have been performed on data collected from bulk tissues, recent studies have demonstrated the importance of cell-type-specific and context-dependent gene regulations in biological processes and disease mechanisms. In this review, we discuss statistical methods that have been developed to enable the detection of cell-type-specific and context-dependent eQTLs from bulk tissues, purified cell types, and single cells. We also discuss the limitations of the current methods and future research opportunities.展开更多
Comprehensive characterization of spatial and temporal gene expression patterns in humans is critical for uncovering the regulatory codes of the human genome and understanding the molecular mechanisms of human disease...Comprehensive characterization of spatial and temporal gene expression patterns in humans is critical for uncovering the regulatory codes of the human genome and understanding the molecular mechanisms of human diseases.Ubiquitously expressed genes(UEGs)refer to the genes expressed across a majority of,if not all,phenotypic and physiological conditions of an organism.It is known that many human genes are broadly expressed across tissues.However,most previous UEG studies have only focused on providing a list of UEGs without capturing their global expression patterns,thus limiting the potential use of UEG information.In this study,we proposed a novel data-driven framework to leverage the extensive collection of40,000 human transcriptomes to derive a list of UEGs and their corresponding global expression patterns,which offers a valuable resource to further characterize human transcriptome.Our results suggest that about half(12,234;49.01%)of the human genes are expressed in at least 80%of human transcriptomes,and the median size of the human transcriptome is 16,342 genes(65.44%).Through gene clustering,we identified a set of UEGs,named LoVarUEGs,which have stable expression across human transcriptomes and can be used as internal reference genes for expression measurement.To further demonstrate the usefulness of this resource,we evaluated the global expression patterns for 16 previously predicted disallowed genes in islet beta cells and found that seven of these genes showed relatively more varied expression patterns,suggesting that the repression of these genes may not be unique to islet beta cells.展开更多
Magnetically driven microrobots hold great potential to perform specific tasks more locally and less invasively in the human body.To reach the lesion area in vivo,microrobots should usually be navigated in flowing blo...Magnetically driven microrobots hold great potential to perform specific tasks more locally and less invasively in the human body.To reach the lesion area in vivo,microrobots should usually be navigated in flowing blood,which is much more complex than static liquid.Therefore,it is more challenging to design a corresponding precise control scheme.A considerable amount of work has been done regarding control of magnetic microrobots in a flow and the corresponding theories.In this paper,we review and summarize the state-of-the-art research progress concerning magnetic microrobots in blood flow,including the establishment of flow systems,dynamics modeling of motion,and control methods.In addition,current challenges and limitations are discussed.We hope this work can shed light on the efficient control of microrobots in complex flow environments and accelerate the study of microrobots for clinical use.展开更多
基金supported by the Natural Science Foundation of China(No.52174232)the Project was supported by Open Research Grant of Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining(Nos.EC2022003 and EC2023005)+1 种基金Anhui University of Science and Technology 2023 Graduate Student Innovation Fund(No.2023cx2106)Open Research Grant of Anhui Engineering Research Center for Coal Clean Processing and Carbon Emission Reduction(No.CCCE-2023003).
文摘This study delves into the intricate relationship between iron(Fe)content in kaolinite and its impact on the adsorption behavior of sodium oleate.The effects of different iron concentrations on adsorption energy,hydrogen bond kinetics and adsorption efficiency were studied through simulation and experimental verification.The results show that the presence of iron in the kaolinite structure significantly improves the adsorption capacity of sodium oleate.Kaolinite samples with high iron content have better adsorption properties,lower adsorption energy levels and shorter and stronger hydrogen bonds than pure kaolinite.The optimal concentration of oleic acid ions for achieving maximum adsorption efficiency was identified as 1.2 mmol/L across different kaolinite samples.At this concentration,the adsorption rates and capacities reach their peak,with Fe-enriched kaolinite samples exhibiting notably higher flotation recovery rates.This optimal concentration represents a balance between sufficient oleic acid ion availability for surface interactions and the prevention of self-aggregation phenomena that could hinder adsorption.This study offers promising avenues for optimizing the flotation process in mineral processing applications.
基金financially sponsored by the National Natural Science Foundation of China(Grant Nos.22075223,22179104)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2022-ZD-4)。
文摘Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.51872112 and 51772120)。
文摘Pressure is one of the necessary conditions for diamond growth.Exploring the influence of pressure on growth changes in silicon-doped diamonds is of great value for the production of high-quality diamonds.This work reports the morphology,impurity content and crystal quality characteristics of silicon-doped diamond crystals synthesized under different pressures.Fourier transform infrared spectroscopy shows that with the increase of pressure,the nitrogen content in the C-center inside the diamond crystal decreases.X-ray photoelectron spectroscopy test results show the presence of silicon in the diamond crystals synthesized by adding silicon powder.Raman spectroscopy data shows that the increase in pressure in the Fe-Ni-C-Si system shifts the Raman peak of diamonds from 1331.18 cm^(-1)to 1331.25 cm^(-1),resulting in a decrease in internal stress in the crystal.The half-peak width decreased from 5.41 cm^(-1)to 5.26 cm^(-1),and the crystallinity of the silicon-doped diamond crystals improved,resulting in improved quality.This work provides valuable data that can provide a reference for the synthesis of high-quality silicon-doped diamonds.
基金funded by the National Key R&D Program of China(2021YFA1501101)the National Natural Science Foundation of China(NSFC)(Nos.21931001 and 21922105)+5 种基金the Special Fund Project of Guiding Scientifi c and Technological Inno-vation Development of Gansu Province(No.2019ZX-04)the 111 Project(B20027)“Innovation Star”of Outstanding Graduate Students in Gansu Province(No.2023CXZX-083)as well as by the Fundamental Research Funds for the Central Universities(Nos.lzu-jbky-2021-pd04,lzujbky-2021-sp41,and lzujbky-2021-it12)Jie Yin acknowledges the support of the China Postdoctoral Science Founda-tion(No.2021M691375)the China National Postdoctoral Program for Innovative Talents(No.BX20200157).
文摘Oxygen evolution reaction(OER)in acid media has been intensively studied recently for its important role in proton exchange membrane electrolyzers.CeO_(2)-based nanomaterials have been widely used in various applications for their redox properties,oxygen vacancy,and surface activity.CeO_(2)-based nanocatalysts also exhibit superior catalytic performance in OER in acid media.Herein,we fabricated a highly effi cient catalytic interface between IrO x and CeO_(2)(IrO x/CeO_(2)),which showed a boosting OER activity with an overpotential of 217 mV at the current density of 10 mA/cm 2 and long-term stability for 10 h in 0.5 mol/L H_(2)SO_(4),which were better than those of many reported catalysts.The in situ diff erential electrochemical mass spectrometry results demonstrated that IrO x/CeO_(2)and the commercial IrO 2(IrO 2-com)followed the adsorbate evolution mechanism,whereas the pure CeO_(2)surface followed the lattice oxygen oxidation mechanism under the same conditions for OER.These indicated that the interface of IrO x and CeO_(2)improved mass transfer effi ciency and reactivity,which also prevented the lattice oxygen evolution in the CeO_(2)structure and protected the whole structure.This work fi nds a new way for OER in acid media catalyzed by CeO_(2)-based nanocatalysts and promotes the design strategy for other CeO_(2)-based nanostructures.
文摘This paper stems from an artistic experiment,in which a distinguished violinist received completely different prices for performing in varying locations.This may be due to the difference in the performance locations,and the value of art in the heart of the audience.
基金supported in part by National Institute on Drug Abuse(NIDA)grants K01 DA029643 and R01DA016750National Institute on Alcohol Abuse and Alcoholism(NIAAA)grants R21 AA021380 and R21 AA020319+9 种基金the National Alliance for Research on Schizophrenia and Depression(NARSAD)Award 17616(L.Z.)ABMRF/The Foundation for Alcohol Research(L.Z.)Funding and other supports for phenotype and genotype data were provided through the National Institutes of Health(NIH)Genes,Environment and Health Initiative(GEI)(U01HG004422,U01HG004436 and U01HG004438)the GENEVA Coordinating Center(U01HG004446)the NIAAA(U10AA008401,R01AA013320,P60AA011998)the NIDA(R01DA013423)the National Cancer Institute(P01 CA089392)the NIH contract‘High throughput genotyping for studying the genetic contributions to human disease’(HHSN268200782096C)the Center for Inherited Disease Research(CIDR)the National Center for Biotechnology Information.Genotyping was performed at the Johns Hopkins University Center for Inherited Disease Research
基金supported by Beijing Municipal Education Commission Science and Technology Development Plan key project(KZ201210005007)the Beijing Municipal Education Commission Science and Technology Development Plan project(KM201010005011,KM201310005020)
文摘The performance of the flexibility and stretchability of flexible electronics depends on the mechanical structure design,for which a great progress has been made in past years.The use of prestrain in the substrate,causing the compression of the transferred interconnects,can provide high elastic stretchability.Recently,the nonbuckling interconnects have been designed,where thick bar replaces thin ribbon layout to yield scissor-like in-plane deformation instead of in-or out-of-plane buckling modes.The nonbuckling interconnect design achieves significantly enhanced stretchability.However,combined use of prestrain and nonbuckling interconnects has not been explored.This paper aims to study the mechanical behavior of nonbuckling interconnects bonded to the prestrained substrate analytically and numerically.It is found that larger prestrain,longer straight segment,and smaller arc radius yield smaller strain in the interconnects.On the other hand,larger prestrain can also cause larger strain in the interconnects after releasing the prestrain.Therefore,the optimization of the prestrain needs to be found to achieve favorable stretchability.
文摘[Objectives]A method for the determination ofβ-sitosterol in Plumbago zeylanica L.was established and the content ofβ-sitosterol in different medicinal parts,different producing areas and different harvest periods were compared.[Methods]High performance liquid chromatography(HPLC)-evaporative light scattering detector assay was used.The chromatographic column was Kromasil C_(18) column(250 mm×4.6 mm,5μm);the mobile phase was pure methanol;the flow rate was 1.0 mL/min;the column temperature was 30℃.The detection parameters of evaporative light scattering detector were as follows:drift tube temperature was 40℃,carrier gas(N_(2))pressure was 3.5 bar.[Results]There was a good linear relationship betweenβ-sitosterol(1.080-4.860μg)and the natural logarithm of peak area(r=0.9995).The average recovery rate was 99.80%.The content ofβ-sitosterol in root and stem was 0.2074 and 0.4064 mg/g,respectively,but it was not found in leaves;the content ofβ-sitosterol in P.zeylanica L.in Guangxi was generally lower than that in Yunnan,and the content ofβ-sitosterol in P.zeylanica L.in Xishuangbanna was the highest;the content ofβ-sitosterol in the stem of P.zeylanica L.was stable at a relatively high level in different harvest periods.[Conclusions]The method is simple,accurate and reproducible,and can be used as one of the methods to control the quality of P.zeylanica L.
基金supported by grants from the National Natural Science Foundation of China(No.31872854).
文摘In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phosphorus,and 10 indicators including root phenotype,phosphorus utilization efficiency at the seedling stage and yield were measured.Through single-index cluster analysis,the performance value and relative value of the abovementioned indexes under low-phosphorus conditions were analyzed,and then,the combined indexes were analyzed by principal components method.The membership function method and the cluster analysis method was used to calculate and analyze the comprehensive score value.Three indexes of root P utilization efficiency(X_(1)),relative value of root P utilization efficiency(X_(2)),and root volume(X_(3))under low P at the seedling stage were selected as the most consistent with the yield screening results under low P condition,and the mathematical model of the comprehensive score value was obtained:D=1.218X_(1)t 0.320X_(2)t 0.007X_(3)-0.664(P=0.000,R^(2)=1.000).The comprehensive score can screen and identify the P efficiency of soybeans with fewer indexes in the early growth stages,which provides a more rapid and reliable mathematical model for screening and identifying a larger number of germplasm resources for P efficiency.
文摘With the rapid development of globalization,the industries of various countries are actively seeking the best way to improve the global value chain(GVC)status while integrating into the world.As an important factor affecting the GVC status,foreign direct investment(FDI)has attracted extensive attention from scholars.On the basis of systematically summarizing the research progress of FDI theory,GVC status and the influence of FDI on GVC status,the paper tries to clarify the internal relationship between FDI and GVC status,explores the shortcomings of existing research,and puts forward the possible direction of future research.
文摘With the development of teaching Chinese as a foreign language, the teaching level of teachers of Chinese as a foreign language is constantly improving. Teachers of Chinese as a foreign language are the messengers of Chinese culture and represent the image of China. Therefore, the quality of teaching Chinese as a foreign language teachers plays a vital role in the quality of teaching Chinese as a foreign language. Immersion teaching method is a relatively successful teaching method in the field of foreign bilingual teaching. It opens a new door for teaching Chinese as a foreign language and plays an important role in improving students' ability to use Chinese. This paper comprehensively evaluates the teaching of Chinese as a whole based on immersive teaching, and calculates the data after evaluation of the evaluation index system to ensure the scientific and accurate evaluation results. Finally, it is proposed that the countermeasures should be improved from the three aspects of classroom teaching, the quality of Chinese teachers and the overall quality of the team of Chinese as a foreign language.
基金supported by the National Key Research and Development Program of China(2022YFF0801903)the National Natural Science Foundation of China(41690145)+2 种基金the State Key Laboratory of Earth Surface Processes and Resource Ecology(2021-TS-06,2021-KF-06,and 2022-ZD-05)the Fundamental Research Funds for the Central Universities(2021NTST16)the Beijing Normal University Talent Introduction Project of China(12807-312232101)。
基金National Key Research and Development Program of China(2021 YFF1000404)National Natural Science Foun-dation of China(32130096)+1 种基金Central Public-interest Scientific Insti-tution Basal Research Fund(Y2022QC14)K.Y.was supported by the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.
文摘Salicylic acid(SA)plays a pivotal role in plant response to biotic and abiotic stress.Several core SA signaling regulators and key proteins in SA biosynthesis have been well characterized.However,much remains unknown about the origin,evolution,and early diversification of core elements in plant SA signaling and biosynthesis.In this study,we identified 10 core protein families in SA signaling and biosynthesis across green plant lineages.We found that the key SA signaling receptors,the nonexpresser of pathogenesis-related(NPR)proteins,originated in the most recent common ancestor(MRCA)of land plants and formed divergent groups in the ancestor of seed plants.However,key transcription factors for SA signaling,TGACG motif-binding proteins(TGAs),originated in the MRCA of streptophytes,arguing for the stepwise evolution of core SA signaling in plants.Different from the assembly of the core SA signaling pathway in the ancestor of seed plants,SA exists extensively in green plants,including chlorophytes and streptophyte algae.However,the full isochorismate synthase(ICS)-based SA synthesis pathway was first assembled in the MRCA of land plants.We further revealed that the ancient abnormal inflorescence meristem 1(AIM1)-basedβ-oxidation pathway is crucial for the biosynthesis of SA in chlorophyte algae,and this biosynthesis pathway may have facilitated the adaptation of early-diverging green algae to the high-light-intensity environment on land.Taken together,our findings provide significant insights into the early evolution and diversification of plant SA signaling and biosynthesis pathways,highlighting a crucial role of SA in stress tolerance during plant terrestrialization.
基金funded by the Shenzhen Institute of Artificial Intelligence and Robotics for Society(AC01202101106).
文摘Untethered microrobots can be used for cargo delivery(e.g.,drug molecules,stem cells,and genes)targeting designated areas.However,it is not enough to just reach the lesion site,as some drugs can only play the best therapeutic effect within the cells.To this end,folic acid(FA)was introduced into microrobots in this work as a key to mediate endocytosis of drugs into cells.The microrobots here were fabricated with biodegradable gelatin methacryloyl(GelMA)and modified with magnetic metal-organic framework(MOF).The porous structure of MOF and the hydrogel network of polymerized GelMA were used for the loading of enough FA and anticancer drug doxorubicin(DOX)respectively.Utilizing the magnetic property of magnetic MOF,these microrobots can gather around the lesion site with the navigation of magnetic fields.The combination effects of FA targeting and magnetic navigation substantially improve the anticancer efficiency of these microrobots.The result shows that the cancer cells inhibition rate of microrobots with FA can be up to 93%,while that of the ones without FA was only 78%.The introduction of FA is a useful method to improve the drug transportation ability of microrobots,providing a meaningful reference for further research.
文摘An expression quantitative trait locus (eQTL) is a chromosomal region where genetic variants are associated with the expression levels of specific genes that can be both nearby or distant. The identifications of eQTLs for different tissues, cell types, and contexts have led to a better understanding of the dynamic regulations of gene expressions and implications of functional genes and variants for complex traits and diseases. Although most eQTL studies have been performed on data collected from bulk tissues, recent studies have demonstrated the importance of cell-type-specific and context-dependent gene regulations in biological processes and disease mechanisms. In this review, we discuss statistical methods that have been developed to enable the detection of cell-type-specific and context-dependent eQTLs from bulk tissues, purified cell types, and single cells. We also discuss the limitations of the current methods and future research opportunities.
基金We thank Dr.Yongkun Wang from the Network and Information Center at Shanghai Jiao Tong University(SJTU)for his support in high-performance computing.We thank Ph.D.Candidate Wei Liu from Yale University for her support in the acquisition of physiological trait-related genes.HL is supported by the National Key R&D Program of China(Grant No.2018YFC0910500)JG and JD are supported by the SJTU-Yale Collaborative Research Seed Fund and Neil Shen’s SJTU Medical Research Fund,China.JG and HL are partially supported by the Shanghai Municipal Commission of Health and Family Planning,China(Grant No.2018ZHYL0223)the Science and Technology Commission of Shanghai Municipality(STCSM),China(Grant No.17DZ2251200).
文摘Comprehensive characterization of spatial and temporal gene expression patterns in humans is critical for uncovering the regulatory codes of the human genome and understanding the molecular mechanisms of human diseases.Ubiquitously expressed genes(UEGs)refer to the genes expressed across a majority of,if not all,phenotypic and physiological conditions of an organism.It is known that many human genes are broadly expressed across tissues.However,most previous UEG studies have only focused on providing a list of UEGs without capturing their global expression patterns,thus limiting the potential use of UEG information.In this study,we proposed a novel data-driven framework to leverage the extensive collection of40,000 human transcriptomes to derive a list of UEGs and their corresponding global expression patterns,which offers a valuable resource to further characterize human transcriptome.Our results suggest that about half(12,234;49.01%)of the human genes are expressed in at least 80%of human transcriptomes,and the median size of the human transcriptome is 16,342 genes(65.44%).Through gene clustering,we identified a set of UEGs,named LoVarUEGs,which have stable expression across human transcriptomes and can be used as internal reference genes for expression measurement.To further demonstrate the usefulness of this resource,we evaluated the global expression patterns for 16 previously predicted disallowed genes in islet beta cells and found that seven of these genes showed relatively more varied expression patterns,suggesting that the repression of these genes may not be unique to islet beta cells.
基金supported by the Shenzhen Institute of Artificial Intelligence and Robotics for Society,China (No.AC01202101106)。
文摘Magnetically driven microrobots hold great potential to perform specific tasks more locally and less invasively in the human body.To reach the lesion area in vivo,microrobots should usually be navigated in flowing blood,which is much more complex than static liquid.Therefore,it is more challenging to design a corresponding precise control scheme.A considerable amount of work has been done regarding control of magnetic microrobots in a flow and the corresponding theories.In this paper,we review and summarize the state-of-the-art research progress concerning magnetic microrobots in blood flow,including the establishment of flow systems,dynamics modeling of motion,and control methods.In addition,current challenges and limitations are discussed.We hope this work can shed light on the efficient control of microrobots in complex flow environments and accelerate the study of microrobots for clinical use.