Epilepsy is a common neurological disorder that occurs at all ages.Epilepsy not only brings physical pain to patients,but also brings a huge burden to the lives of patients and their families.At present,epilepsy detec...Epilepsy is a common neurological disorder that occurs at all ages.Epilepsy not only brings physical pain to patients,but also brings a huge burden to the lives of patients and their families.At present,epilepsy detection is still achieved through the observation of electroencephalography(EEG)by medical staff.However,this process takes a long time and consumes energy,which will create a huge workload to medical staff.Therefore,it is particularly important to realize the automatic detection of epilepsy.This paper introduces,in detail,the overall framework of EEG-based automatic epilepsy identification and the typical methods involved in each step.Aiming at the core modules,that is,signal acquisition analog front end(AFE),feature extraction and classifier selection,method summary and theoretical explanation are carried out.Finally,the future research directions in the field of automatic detection of epilepsy are prospected.展开更多
Objective:To explore the mechanism and related active components of Yishen Daluo decoction(YSDLD)in treating multiple sclerosis(MS).Methods:Targets of YSDLD were collected through the TCMSP,Chemistry,and TCMID databas...Objective:To explore the mechanism and related active components of Yishen Daluo decoction(YSDLD)in treating multiple sclerosis(MS).Methods:Targets of YSDLD were collected through the TCMSP,Chemistry,and TCMID databases.The MS targets were collected through OMIM,DrugBank,Gencards,TTD,and Pharmgkb databases.We built“componentetarget”network diagrams and proteineprotein interaction(PPI)diagrams and performed topological analysis.The targets were subjected to GO and KEGG enrichment analysis.Molecular docking verification was conducted on selected targets and molecules.Finally,in vitro experiments were con-ducted.BV2 cells were induced by lipopolysaccharide for model establishment.CCK8 experiment was conducted to explore the effect of YSDLD and RT-qPCR technology was used to explore the expression of key targets.Results:There were 184 active components in YSDLD and 898 targets of its action.There were 940 MS targets,and 215 targets were shared by YSDLD and MS.According to the“componentetarget”diagram,the top five key components included quercetin,kaempferol,beta-sitosterol,stigmasterol,and nar-ingenin.IL-6,IL-1 b,TNF-α,AKT1,and VEGFA were the important targets identified by PPI network to-pology analysis.A total of 564 functions were identified by GO enrichment analysis(P<0.01),mainly involving inflammatory response,hypoxia response,plasma membrane,neuronal cell body,protein phosphatase binding,and cytokine activity.KEGG enrichment analysis enriched 98 pathways(P<.01).YSDLD at the concentration of 20 m g/mL had no effect on BV2 cells.RT-qPCR indicated that YSDLD at the concentrations of 15 m g/mL and 20 m g/mL alleviated LPS-induced inflammatory injury and lowered the content of inflammatory factors(P<0.05).Conclusion:In this paper,the network pharmacology and in vitro experiments were used to explore the potential mechanism of YSDLD in treating MS.The research provides a good basis for the development of YSDLD and drugs for MS in future.展开更多
Ischemic cerebrovascular disease is a leading cause of death globally and is often exacerbated by cerebral ischemic/reperfusion injury(CIRI).The exact mechanisms underlying I/R injury are unclear.In this study,we aime...Ischemic cerebrovascular disease is a leading cause of death globally and is often exacerbated by cerebral ischemic/reperfusion injury(CIRI).The exact mechanisms underlying I/R injury are unclear.In this study,we aimed to determine the role of m6A-modified methylase complex methyltransferase-like 3(METTL3)in cerebral ischemiareperfusion(I/R)injury.We found that m6A and METTL3 levels increased in OGD/RX-induced mouse astrocytescerebellar(MA-C)and the brain of middle cerebral artery occlusion(MCAO)model mice.METTL3 siRNA treatment reduced OGD-RX-induced MAC cell viability and proliferation,which increased with METTL3 over-expression.Flow cytometry analysis showed that silencing METTL3 significantly enhanced OGD/RX-induced MAC apoptosis,which was significantly reduced with METTL3 up-regulation.In an MCAO model,METTL3 overexpression significantly reduced cerebral infarction area and decreased brain cell apoptosis,indicating that METTL3 OE treatment could ameliorate brain edema and injury.Thus,METTL3 could be used as a target to treat I/R injury.展开更多
Tea is an important cash crop, representing a $40 billion-a-year global market. Differentiation of the tea market has resulted in increasing demand for tea products that are sustainably and responsibly produced. Tea a...Tea is an important cash crop, representing a $40 billion-a-year global market. Differentiation of the tea market has resulted in increasing demand for tea products that are sustainably and responsibly produced. Tea authentication is important because of growing concerns about fraud involving premium tea products. Analytical technologies are needed for protection and value enhancement of high-quality brands. For loose-leaf teas, the challenge is that the authentication needs to be established on the basis of a single leaf, so that the products can be traced back to the original varieties. A new generation of molecular markers offers an ideal solution for authentication of processed agricultural products. Using a nanofluidic array to identify variant SNP sequences, we tested genetic identities using DNA extracted from single leaves of 14 processed commercial tea products. Based on the profiles of 60 SNP markers, the genetic identity of each tea sample was unambiguously identified by multilocus matching and ordination analysis. Results for repeated samples of multiple tea leaves from the same products(using three independent DNA extractions) showed 100% concordance, showing that the nanofluidic system is a reliable platform for generating tea DNA fingerprints with high accuracy. The method worked well on green, oolong, and black teas, and can handle a large number of samples in a short period of time. It is robust and cost-effective, thus showing high potential for practical application in the value chain of the tea industry.展开更多
A nozzle clogging online forecasting model based on hydrodynamics engineering was developed, in which the actual flow rate was calculated from the mold width, thickness, and casting speed. There is a linear relationsh...A nozzle clogging online forecasting model based on hydrodynamics engineering was developed, in which the actual flow rate was calculated from the mold width, thickness, and casting speed. There is a linear relationship between the theoretical flow rate and the slide gate opening ratio as the molten steel level, argon flow rate, and the top slag weight are kept constant, and the relationship can be obtained by regression of the data collected at the beginning of the first heat in each casting sequence when the nozzle clogging does not occur. Then, during the casting, the theoretical flow rate can be calculated at intervals of one second. Comparing the theoretical flow rate with the actual flow rate, the online nozzle clogging ratio can be obtained at intervals of one second. The computer model based on the conception of the nozzle clogging ratio can display the degree of the nozzle clogging intuitively.展开更多
Cysteine-rich polycomb-like(CPP)is a small gene family in plants,which plays key role in plant development and stress response.Although CPP transcription factors have been characterized in several other plant species,...Cysteine-rich polycomb-like(CPP)is a small gene family in plants,which plays key role in plant development and stress response.Although CPP transcription factors have been characterized in several other plant species,a genome-wide characterization of the CPP gene family has been absent in Camellia sinensis.In this study,we totally identified 7,8,and 8 non-redundant CsCPP genes in three published genomes,including Camellia sinensis var.assamica cv.Yunkang-10(CSA-YK10),Camellia sinensis var.sinensis cv.Biyun(CSS-BY)and Camellia sinensis var.sinensis cv.Shuchazao(CSS-SCZ).CPP proteins from tea tree and other plant species were classified into three groups,which were further divided into four subgroups based on phylogenetic relationships.Most CPP genes in the same subgroup had similar gene structures and conserved motifs.The cis-acting elements analysis indicated that CPP genes might be involved in plant growth,development and stress responses.Analysis of gene expression using qRT-PCR experiments validated that CPP genes exhibited different expression patterns across the examined tissues.All the genes were expressed differentially in a range of tissues,indicating that CPPs were involved in a range of developmental and physiological processes.This study has obtained new insights into the evolution and function of the CPP gene family in the growth and development of tea plants,and also provide candidate genes for further functional characterization in tea tree.展开更多
The effects of various factors,such as argon flow rate and slide gate opening ratio,on the alumina deposition rate were re- searched by the numerical simulation method.The pressure in the nozzle is significantly affec...The effects of various factors,such as argon flow rate and slide gate opening ratio,on the alumina deposition rate were re- searched by the numerical simulation method.The pressure in the nozzle is significantly affected by argon flow rate and slide gate opening ratio.To keep positive pressure in the nozzle,the argon flow rate should be increased with a decrease in slide gate opening ratio.The effect of argon flow rate on the alumina deposition rate depends on the condition of opening ratio or casting speed.The ef- fect of increasing the argon flow rate on the deposition rate is not obvious when the opening ratio is small.The Al_2O_3 deposition rate decreases significantly with an increase in argon flow rate when the argon flow rate is low,but it decreases slowly when the argon flow rate reaches a certain value.The alumina deposition rate is linear with alumina content at different slide gate opening ratios and argon flow rates.The observed thickness of the deposition layer at the bottom and outlet of a real clogged nozzle is almost equal to the result of the numerical simulation.展开更多
Based on the data of GDP per capita and emissions of major pollutants in Binzhou City from 2013 to 2017,the changing trends of emissions of major pollutants with the increase of GDP per capita,as well as the coordinat...Based on the data of GDP per capita and emissions of major pollutants in Binzhou City from 2013 to 2017,the changing trends of emissions of major pollutants with the increase of GDP per capita,as well as the coordinated development level of ecological environment and social economy in Binzhou City were studied.The results showed that with the increase of GDP per capita,the changing curves of industrial wastewater and industrial soot in Binzhou City were inverted-U-shaped,and the emission of industrial wastewater reduced after peaking.However,the production of industrial solid waste and the emission of industrial waste gas did not show a downward trend with economic growth,and still increased year by year.The coordination degree of economic development and ecological environment protection in Binzhou City was moderately lagged.By the adjustment of industrial structure,environmental protection and control should be increased,and relevant regulations should be formulated to control pollutant emissions,thereby achieving sustainable development and coordinated development of regional ecology and environment.展开更多
Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic methods.However,...Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic methods.However,the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B-H bond condensation reaction,critical for the synthesis of the polyhedral boranes,is not well understood.Here we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate(1-)(B_(11)H^(-)_(14)) and dodecahydrido-dodecaborates(2-)(B_(12)H_(12)^(2-)) anions by employing commercially available and inexpensive starting materials.Both theoretical and experimental investigations are carried out to elucidate the reaction mechanisms.We have found that the nature of the B-H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens(bridged hydrogens) play a crucial role.The current study has not only led to more effective and selective synthetic methods for B_(11)H^(-)_(14) and B_(12)H_(12)^(2-) but also unveiled the nature of the B-H bond condensation and the general formation mechanisms of polyhedral boranes.This finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application.展开更多
We present a systematic and efficient Chebyshev spectral method using quasiinverse technique to directly solve the second order equation with the homogeneous Robin boundary conditions and the fourth order equation wit...We present a systematic and efficient Chebyshev spectral method using quasiinverse technique to directly solve the second order equation with the homogeneous Robin boundary conditions and the fourth order equation with the first and second boundary conditions.The key to the efficiency of the method is to multiply quasiinverse matrix on both sides of discrete systems,which leads to band structure systems.We can obtain high order accuracy with less computational cost.For multi-dimensional and more complicated linear elliptic PDEs,the advantage of this methodology is obvious.Numerical results indicate that the spectral accuracy is achieved and the proposed method is very efficient for 2-D high order problems.展开更多
The optical and optoelectronic characteristics of SnS nanosheets with strong anisotropic crystal structure are researched.Transmission electron microscopy and polarized Raman spectra are used to determine the crystal ...The optical and optoelectronic characteristics of SnS nanosheets with strong anisotropic crystal structure are researched.Transmission electron microscopy and polarized Raman spectra are used to determine the crystal orientation of SnS nanosheets.The photodetector based on SnS nanosheets exhibits the carrier mobility of 37.75 cm^(2)/V·s,photoresponsivity of 310.5 A/W and external quantum efficiency of 8.56×10^(4)%at 450 nm.Optical absorption around the absorption edge presents obvious polarization sensitivity with the highest optical absorption dichroic ratio of 3.06 at 862 nm.Due to anisotropic optical absorption,the polarized photocurrent appears as the periodic change affected by the polarized direction of the incident light at 808 nm.Overall,SnS nanosheets show good potential in the future application of the polarized photodetectors for specific wavelength.展开更多
To the Editor:Esophageal squamous cell carcinoma(ESCC)is the seventh most common malignant cancer worldwide.[1]There is an urgent need to find sensitive and specific biomarkers to improve ESCC diagnosis and prognosis.
Here,we report a theoretical investigation of the reactivity and chemoselectivity of carbene-enabled ether activation.The mechanism obtained from DFT calculations revealed that the final products were dependent on the...Here,we report a theoretical investigation of the reactivity and chemoselectivity of carbene-enabled ether activation.The mechanism obtained from DFT calculations revealed that the final products were dependent on the stability of the oxonium intermediate,which was afforded by nucleophilic attack of the corresponding ether onto a carbene species.Interestingly,we found that the nucleophilicity of ethers was crucial but not their solvation.Energy decomposition analysis based on absolutely localized molecular orbitals showed that the nucleophilicity of ethers was critical for polarization and charge transfer,leading to the chemoselectivity.展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences,Grant No.XDA0330000 and Grant No.XDB44000000。
文摘Epilepsy is a common neurological disorder that occurs at all ages.Epilepsy not only brings physical pain to patients,but also brings a huge burden to the lives of patients and their families.At present,epilepsy detection is still achieved through the observation of electroencephalography(EEG)by medical staff.However,this process takes a long time and consumes energy,which will create a huge workload to medical staff.Therefore,it is particularly important to realize the automatic detection of epilepsy.This paper introduces,in detail,the overall framework of EEG-based automatic epilepsy identification and the typical methods involved in each step.Aiming at the core modules,that is,signal acquisition analog front end(AFE),feature extraction and classifier selection,method summary and theoretical explanation are carried out.Finally,the future research directions in the field of automatic detection of epilepsy are prospected.
基金This work was supported by the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chi-nese Medicine(ZYYCXTD-C-202006).
文摘Objective:To explore the mechanism and related active components of Yishen Daluo decoction(YSDLD)in treating multiple sclerosis(MS).Methods:Targets of YSDLD were collected through the TCMSP,Chemistry,and TCMID databases.The MS targets were collected through OMIM,DrugBank,Gencards,TTD,and Pharmgkb databases.We built“componentetarget”network diagrams and proteineprotein interaction(PPI)diagrams and performed topological analysis.The targets were subjected to GO and KEGG enrichment analysis.Molecular docking verification was conducted on selected targets and molecules.Finally,in vitro experiments were con-ducted.BV2 cells were induced by lipopolysaccharide for model establishment.CCK8 experiment was conducted to explore the effect of YSDLD and RT-qPCR technology was used to explore the expression of key targets.Results:There were 184 active components in YSDLD and 898 targets of its action.There were 940 MS targets,and 215 targets were shared by YSDLD and MS.According to the“componentetarget”diagram,the top five key components included quercetin,kaempferol,beta-sitosterol,stigmasterol,and nar-ingenin.IL-6,IL-1 b,TNF-α,AKT1,and VEGFA were the important targets identified by PPI network to-pology analysis.A total of 564 functions were identified by GO enrichment analysis(P<0.01),mainly involving inflammatory response,hypoxia response,plasma membrane,neuronal cell body,protein phosphatase binding,and cytokine activity.KEGG enrichment analysis enriched 98 pathways(P<.01).YSDLD at the concentration of 20 m g/mL had no effect on BV2 cells.RT-qPCR indicated that YSDLD at the concentrations of 15 m g/mL and 20 m g/mL alleviated LPS-induced inflammatory injury and lowered the content of inflammatory factors(P<0.05).Conclusion:In this paper,the network pharmacology and in vitro experiments were used to explore the potential mechanism of YSDLD in treating MS.The research provides a good basis for the development of YSDLD and drugs for MS in future.
基金supported by the Natural Science Foundation of Guangdong Province(Grant No.2020A151501287)the General Project of Science and Technology Innovation Commission of Shenzhen(Grant Nos.JCYJ20210324134800001,JCYJ20190808103401655)+1 种基金Basic Public Welfare Research Project of Zhejiang Province(Grant No.LGF21H090011)the National Natural Science Foundation of China(Grant No.82174132).
文摘Ischemic cerebrovascular disease is a leading cause of death globally and is often exacerbated by cerebral ischemic/reperfusion injury(CIRI).The exact mechanisms underlying I/R injury are unclear.In this study,we aimed to determine the role of m6A-modified methylase complex methyltransferase-like 3(METTL3)in cerebral ischemiareperfusion(I/R)injury.We found that m6A and METTL3 levels increased in OGD/RX-induced mouse astrocytescerebellar(MA-C)and the brain of middle cerebral artery occlusion(MCAO)model mice.METTL3 siRNA treatment reduced OGD-RX-induced MAC cell viability and proliferation,which increased with METTL3 over-expression.Flow cytometry analysis showed that silencing METTL3 significantly enhanced OGD/RX-induced MAC apoptosis,which was significantly reduced with METTL3 up-regulation.In an MCAO model,METTL3 overexpression significantly reduced cerebral infarction area and decreased brain cell apoptosis,indicating that METTL3 OE treatment could ameliorate brain edema and injury.Thus,METTL3 could be used as a target to treat I/R injury.
文摘Tea is an important cash crop, representing a $40 billion-a-year global market. Differentiation of the tea market has resulted in increasing demand for tea products that are sustainably and responsibly produced. Tea authentication is important because of growing concerns about fraud involving premium tea products. Analytical technologies are needed for protection and value enhancement of high-quality brands. For loose-leaf teas, the challenge is that the authentication needs to be established on the basis of a single leaf, so that the products can be traced back to the original varieties. A new generation of molecular markers offers an ideal solution for authentication of processed agricultural products. Using a nanofluidic array to identify variant SNP sequences, we tested genetic identities using DNA extracted from single leaves of 14 processed commercial tea products. Based on the profiles of 60 SNP markers, the genetic identity of each tea sample was unambiguously identified by multilocus matching and ordination analysis. Results for repeated samples of multiple tea leaves from the same products(using three independent DNA extractions) showed 100% concordance, showing that the nanofluidic system is a reliable platform for generating tea DNA fingerprints with high accuracy. The method worked well on green, oolong, and black teas, and can handle a large number of samples in a short period of time. It is robust and cost-effective, thus showing high potential for practical application in the value chain of the tea industry.
基金financially supported by the State EconomicTrade Commission of China (No.OIBK-098-02-07)
文摘A nozzle clogging online forecasting model based on hydrodynamics engineering was developed, in which the actual flow rate was calculated from the mold width, thickness, and casting speed. There is a linear relationship between the theoretical flow rate and the slide gate opening ratio as the molten steel level, argon flow rate, and the top slag weight are kept constant, and the relationship can be obtained by regression of the data collected at the beginning of the first heat in each casting sequence when the nozzle clogging does not occur. Then, during the casting, the theoretical flow rate can be calculated at intervals of one second. Comparing the theoretical flow rate with the actual flow rate, the online nozzle clogging ratio can be obtained at intervals of one second. The computer model based on the conception of the nozzle clogging ratio can display the degree of the nozzle clogging intuitively.
文摘Cysteine-rich polycomb-like(CPP)is a small gene family in plants,which plays key role in plant development and stress response.Although CPP transcription factors have been characterized in several other plant species,a genome-wide characterization of the CPP gene family has been absent in Camellia sinensis.In this study,we totally identified 7,8,and 8 non-redundant CsCPP genes in three published genomes,including Camellia sinensis var.assamica cv.Yunkang-10(CSA-YK10),Camellia sinensis var.sinensis cv.Biyun(CSS-BY)and Camellia sinensis var.sinensis cv.Shuchazao(CSS-SCZ).CPP proteins from tea tree and other plant species were classified into three groups,which were further divided into four subgroups based on phylogenetic relationships.Most CPP genes in the same subgroup had similar gene structures and conserved motifs.The cis-acting elements analysis indicated that CPP genes might be involved in plant growth,development and stress responses.Analysis of gene expression using qRT-PCR experiments validated that CPP genes exhibited different expression patterns across the examined tissues.All the genes were expressed differentially in a range of tissues,indicating that CPPs were involved in a range of developmental and physiological processes.This study has obtained new insights into the evolution and function of the CPP gene family in the growth and development of tea plants,and also provide candidate genes for further functional characterization in tea tree.
基金the State Economic and Trade Commission of China(No.01BK-098-02-07)
文摘The effects of various factors,such as argon flow rate and slide gate opening ratio,on the alumina deposition rate were re- searched by the numerical simulation method.The pressure in the nozzle is significantly affected by argon flow rate and slide gate opening ratio.To keep positive pressure in the nozzle,the argon flow rate should be increased with a decrease in slide gate opening ratio.The effect of argon flow rate on the alumina deposition rate depends on the condition of opening ratio or casting speed.The ef- fect of increasing the argon flow rate on the deposition rate is not obvious when the opening ratio is small.The Al_2O_3 deposition rate decreases significantly with an increase in argon flow rate when the argon flow rate is low,but it decreases slowly when the argon flow rate reaches a certain value.The alumina deposition rate is linear with alumina content at different slide gate opening ratios and argon flow rates.The observed thickness of the deposition layer at the bottom and outlet of a real clogged nozzle is almost equal to the result of the numerical simulation.
文摘Based on the data of GDP per capita and emissions of major pollutants in Binzhou City from 2013 to 2017,the changing trends of emissions of major pollutants with the increase of GDP per capita,as well as the coordinated development level of ecological environment and social economy in Binzhou City were studied.The results showed that with the increase of GDP per capita,the changing curves of industrial wastewater and industrial soot in Binzhou City were inverted-U-shaped,and the emission of industrial wastewater reduced after peaking.However,the production of industrial solid waste and the emission of industrial waste gas did not show a downward trend with economic growth,and still increased year by year.The coordination degree of economic development and ecological environment protection in Binzhou City was moderately lagged.By the adjustment of industrial structure,environmental protection and control should be increased,and relevant regulations should be formulated to control pollutant emissions,thereby achieving sustainable development and coordinated development of regional ecology and environment.
基金supported by the National Natural Science Foundation of China(22171246,U1804253 to X.C.and 21773214 to D.W.)the National Science Foundation(CHE-2053541 to L.-S.W.)。
文摘Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic methods.However,the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B-H bond condensation reaction,critical for the synthesis of the polyhedral boranes,is not well understood.Here we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate(1-)(B_(11)H^(-)_(14)) and dodecahydrido-dodecaborates(2-)(B_(12)H_(12)^(2-)) anions by employing commercially available and inexpensive starting materials.Both theoretical and experimental investigations are carried out to elucidate the reaction mechanisms.We have found that the nature of the B-H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens(bridged hydrogens) play a crucial role.The current study has not only led to more effective and selective synthetic methods for B_(11)H^(-)_(14) and B_(12)H_(12)^(2-) but also unveiled the nature of the B-H bond condensation and the general formation mechanisms of polyhedral boranes.This finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application.
基金supported by the grants of National Natural Science Foundation of China(No.10731060,10801120)Chinese Universities Scientific Fund No.2010QNA3019.
文摘We present a systematic and efficient Chebyshev spectral method using quasiinverse technique to directly solve the second order equation with the homogeneous Robin boundary conditions and the fourth order equation with the first and second boundary conditions.The key to the efficiency of the method is to multiply quasiinverse matrix on both sides of discrete systems,which leads to band structure systems.We can obtain high order accuracy with less computational cost.For multi-dimensional and more complicated linear elliptic PDEs,the advantage of this methodology is obvious.Numerical results indicate that the spectral accuracy is achieved and the proposed method is very efficient for 2-D high order problems.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.62004193 and 81900912)the National Key Research and Development Program of China(Grant No.2017YFA0207500)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB43000000)Beijing National Laboratory for Molecular Sciences(BNLMS201908).
文摘The optical and optoelectronic characteristics of SnS nanosheets with strong anisotropic crystal structure are researched.Transmission electron microscopy and polarized Raman spectra are used to determine the crystal orientation of SnS nanosheets.The photodetector based on SnS nanosheets exhibits the carrier mobility of 37.75 cm^(2)/V·s,photoresponsivity of 310.5 A/W and external quantum efficiency of 8.56×10^(4)%at 450 nm.Optical absorption around the absorption edge presents obvious polarization sensitivity with the highest optical absorption dichroic ratio of 3.06 at 862 nm.Due to anisotropic optical absorption,the polarized photocurrent appears as the periodic change affected by the polarized direction of the incident light at 808 nm.Overall,SnS nanosheets show good potential in the future application of the polarized photodetectors for specific wavelength.
基金Fundamental Research Funds for the Central Universities(No.lzujbky-2020-54)National Natural Science Foundation of China(No.81803188)。
文摘To the Editor:Esophageal squamous cell carcinoma(ESCC)is the seventh most common malignant cancer worldwide.[1]There is an urgent need to find sensitive and specific biomarkers to improve ESCC diagnosis and prognosis.
基金This project was supported by the National Natural Science Foundation of China(Grants 21903071,21822303 and 21772020)the Program for Science Technology Innovation Talents in Universities of Henan Province(No.20HASTIT004).
文摘Here,we report a theoretical investigation of the reactivity and chemoselectivity of carbene-enabled ether activation.The mechanism obtained from DFT calculations revealed that the final products were dependent on the stability of the oxonium intermediate,which was afforded by nucleophilic attack of the corresponding ether onto a carbene species.Interestingly,we found that the nucleophilicity of ethers was crucial but not their solvation.Energy decomposition analysis based on absolutely localized molecular orbitals showed that the nucleophilicity of ethers was critical for polarization and charge transfer,leading to the chemoselectivity.
