Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can inte...Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can integrate both chlorophyll biosynthesis and flavonoid accumulation in response to specific light signals are rarely identified.In this study,we report that the GOLDEN 2-LIKE TF pair,CsGLK1 and CsGLK2,orchestrate UV-B-induced responses in the chlorophyll biosynthesis and flavonoid accumulation of tea leaves.The absence of solar UV-B reduced the transcriptional expression of CsGLKs in the tea leaves and was highly correlated with a decrease in flavonoid levels(especially flavonol glycosides)and the expression of genes and TFs involved in chlorophyll biosynthesis and flavonoid accumulation.In vivo and in vitro molecular analyses showed that CsGLKs could be regulated by the UV-B signal mediator CsHY5,and could directly bind to the promoters of gene and TF involved in light-harvesting(CsLhcb),chlorophyll biosynthesis(CsCHLH,CsHEMA1,and CsPORA),and flavonoid accumulation(CsMYB12,CsFLSa,CsDFRa,and CsLARa),eventually leading to UV-B-induced responses in the chlorophylls and flavonoids of tea leaves.Furthermore,UV-B exposure increased the levels of total flavonoids,CsGLK1 protein,and expression of CsGLKs and target genes in the tea leaves.These results indicate that CsGLKs may modulate tea leaf characteristics by regulating chlorophyll biosynthesis and flavonoid accumulation in response to solar UV-B.As the first report on UV-B-induced changes in flavonoid and chlorophyll regulation mediated by CsGLKs,this study improves our understanding of the environmental regulations regarding tea quality and sheds new light on UV-B-induced flavonoid responses in higher plants.展开更多
The applications of laser-induced breakdown spectroscopy(LIBS) on classifying complex natural organics are relatively limited and their accuracy still requires improvement.In this work,to study the methods on classifi...The applications of laser-induced breakdown spectroscopy(LIBS) on classifying complex natural organics are relatively limited and their accuracy still requires improvement.In this work,to study the methods on classification of complex organics,three kinds of fresh leaves were measured by LIBS.100 spectra from 100 samples of each kind of leaves were measured and then they were divided into a training set and a test set in a ratio of 7:3.Two algorithms of chemometric methods including the partial least squares discriminant analysis(PLS-DA) and principal component analysis Mahalanobis distance(PCA-MD) were used to identify these leaves.By using 23 lines from 16 elements or molecules as input data,these two methods can both classify these three kinds of leaves successfully.The classification accuracies of training sets are both up to 100% by PCA-MD and PLS-DA.The classification accuracies of the test set are 93.3% by PCA-MD and 97.8% by PLS-DA.It means that PLS-DA is better than PCA-MD in classifying plant leaves.Because the components in PLS-DA process are more suitable for classification than those in PCA-MD process.We think that this work can provide a reference for plant traceability using LIBS.展开更多
Saltation bombardment is a dominate dust emission mechanism in wind erosion.For loose surfaces,splash entrainment has been well understood theoretically.However,the mass loss predictions of cohesive soils are generall...Saltation bombardment is a dominate dust emission mechanism in wind erosion.For loose surfaces,splash entrainment has been well understood theoretically.However,the mass loss predictions of cohesive soils are generally empirical in most wind erosion models.In this study,the soil particle detachment of a bare,smooth,dry,and uncrusted soil surface caused by saltation bombardment is modeled by means of classical mechanics.It is shown that detachment rate can be analytically expressed in terms of the kinetic energy or mass flux of saltating grains and several common mechanical parameters of soils,including Poisson's ratio,Young's modulus,cohesion and friction angle.The novel expressions can describe dust emission rate from cohesive surfaces and are helpful to quantify the anti-erodibility of soil.It is proposed that the mechanical properties of soils should be appropriately included in physically-based wind erosion models.展开更多
As the major bitter-and astringent-tasting components in tea leaves,catechins play an essential role in determining flavor characteristics and health benefits of tea products.This study analyzed the circadian rhythm e...As the major bitter-and astringent-tasting components in tea leaves,catechins play an essential role in determining flavor characteristics and health benefits of tea products.This study analyzed the circadian rhythm effects on the accumulation pattern of catechins in tender leaves of three tea cultivars,'Huangkui'(HK),'Longjing43'(LJ43)and'Fuding Dabaicha'(FD).There were two major factors involved in the catechin regulation in tea plants:genetic background of the cultivar-specific regulation,and temporal effects of the circadian rhythm.Etiolated leaves of'HK'contained lower levels of catechins than'LJ43'and'FD'.The composition of EGCG in total catechins was significantly higher in'LJ43'leaves(65%)when compared with that in'HK'and'FD'(45%).The accumulation of individual catechins increased during the daytime but decreased overnight,especially over the time period of 22:00−02:00.The correlation analysis between catechins and environmental factors indicated catechin accumulation in tea leaves potentially resulted from a combined regulation of light and temperature.These findings provide new insights into our understanding of circadian rhythm regulation on flavor-important secondary metabolites in tea leaves.展开更多
Cigarette smoking is a main source of cyanide in human body,which can be taken as a risk factor of cataract formation.In this study,combined gas chromatography and mass spectrum(GC/MS)was used todetermine the amino ac...Cigarette smoking is a main source of cyanide in human body,which can be taken as a risk factor of cataract formation.In this study,combined gas chromatography and mass spectrum(GC/MS)was used todetermine the amino acid hydantoin after the incubation of soluble humanlensγ-crystallins with cyanate.The carbamylated amino acids obtained bythis procedure are alanine and hlycine,which are N-terminal amino acids ofγ-crystallin,and leucine.The aggregate,which can be observed incarbamylatedγ_1-crystallin on SDS-PAGE,may be related to the formation of disulfide and non-disulfide covalent bonds,and it seems that Y₂and Yy-crystallins can not be aggregated to any great extend.The results in this study indicate that the GC/MS is an effective method for analyzing the carbamylation of lens proteins;y-crystallin may play a very important role in the formation of cataract associated with accumulation of cyanate in human body,such as heavy smoking.展开更多
[Objectives] To study the expression of Med 19 protein in tongue cancer and its significance. [Methods] Immunohistochemical method was used to detect the expression of Med 19 protein in tongue cancer tissue and paraca...[Objectives] To study the expression of Med 19 protein in tongue cancer and its significance. [Methods] Immunohistochemical method was used to detect the expression of Med 19 protein in tongue cancer tissue and paracancerous tissue. [Results]The expression of Med19 protein in tongue cancer tissue was higher than paracancerous tissue and normal tissue. The expression of Med 19 protein was related to the tumor lymph node metastasis. However,there was no significant difference in sex,age,Tumor Node Metastasis( TNM),and differentiation degree. [Conclusions] Med 19 protein participates in incidence and development of tongue cancer and may become diagnostic indicator and therapeutic target for tongue cancer.展开更多
无水氟化铜(CuF_(2))有望成为下一代锂电池正极材料,其高比容量(528 mA h g^(−1))和高工作电压(3.55 V vs.Li/Li^(+))使得其能量密度高达1874 W h kg^(−1).然而,由于充电时铜的溶解,CuF_(2)正极容易失活,这限制了其发展.本研究采用氟化...无水氟化铜(CuF_(2))有望成为下一代锂电池正极材料,其高比容量(528 mA h g^(−1))和高工作电压(3.55 V vs.Li/Li^(+))使得其能量密度高达1874 W h kg^(−1).然而,由于充电时铜的溶解,CuF_(2)正极容易失活,这限制了其发展.本研究采用氟化高浓电解液抑制铜的溶解,从而实现了CuF_(2)正极的可逆循环.采用氟化高浓电解液后,CuF_(2)正极的容量在30次循环后仍保有228 mA h g^(−1),是使用传统碳酸酯类电解液的电池容量的近三倍.综上,本研究提出了一种电解质工程策略,可以实现CuF_(2)正极的可逆充放电.展开更多
The recent revival of Li metal anodes(LMA)leads to a renewed interest in LMA as the ultimate choice for rechargeable lithium batteries towards high energy density.However,multiple challenges stand in the way of using ...The recent revival of Li metal anodes(LMA)leads to a renewed interest in LMA as the ultimate choice for rechargeable lithium batteries towards high energy density.However,multiple challenges stand in the way of using LMA,of which high reactivity,dendrite growth,the difficulty of fabricating Li thin foils,and the flammability of organic liquid electrolytes are typical.Here,a writable Li metal ink(LMI)prepared by introducing biomass-derived carbon particles into molten Li is presented.Due to the significantly decreased surface tension,LMI is able to directly write on copper foils or other substrates that ultrathin Li foils with a remarkably small thickness(<10μm)can be achieved.The versatility of LMI is further demonstrated in addressing the interface issue between LMA and garnet-type solid-state electrolytes,where directly writing LMI on the garnet offers a perfect contact and enables an extremely low interfacial resistance of 6Ωcm^2,in sharp contrast to 939Ωcm^2 between the pure Li and the garnet.Due to the successful partnership with non-flammable solid-state electrolytes,ink-based technology may have a chance to bring us very close to the use of solid-state lithium metal batteries(SSLMBs)with high safety and high energy density.展开更多
Compartmentation of enzymes via filamentation has arisen as a mechanism for the regulation of metabolism.In 2010,three groups independently reported that CTP synthase(CTPS)can assemble into a filamentous structure ter...Compartmentation of enzymes via filamentation has arisen as a mechanism for the regulation of metabolism.In 2010,three groups independently reported that CTP synthase(CTPS)can assemble into a filamentous structure termed the cytoophidium.In searching for CTPS-interacting proteins,here we perform a yeast two-hybrid screening of Drosophila proteins and identify a putative CTPS-interacting protein,△~1-pyrroline-5-carboxylate synthase(P5CS).Using the Drosophila follicle cell as the in vivo model,we confirm that P5CS forms cytoophidia,which are associated with CTPS cytoophidia.Overexpression of P5CS increases the length of CTPS cytoophidia.Conversely,filamentation of CTPS affects the morphology of P5CS cytoophid ia.Finally,in vitro analyses confirm the filament-fo rming property of P5CS.Our work links CTPS with P5CS,two enzymes involved in the rate-limiting steps in pyrimidine and proline biosynthesis,respectively.展开更多
Glaucoma is the second leading cause of blindness after cataract worldwide.However,among irreversible blinding eye diseases,glaucoma is the primary cause(Liang et al.,2011).To date,most studies have indicated that gla...Glaucoma is the second leading cause of blindness after cataract worldwide.However,among irreversible blinding eye diseases,glaucoma is the primary cause(Liang et al.,2011).To date,most studies have indicated that glaucoma is not only an ocular disease,but also an optic nerve disease.In particular,primary open-angle glaucoma(POAG)is characterized by insidious onset,painless visual impairment,and complicated pathological mechanism,and patients with such condition require long-term follow-up.However,the underlying cause of POAG remains unclear,and there are several theories about its exact etiology.Some mechanisms have presented underlying optic nerve damage,which include the mechanical theory,vascular theory,and the in・volvement of other factors.展开更多
Sodium metal anodes(SMAs)sufer from extremely low reversibility(<20%)in carbonate based clectrolytes-this piece of knowledge gained from previous studics has ruled out the application of carbonate solvents for sodi...Sodium metal anodes(SMAs)sufer from extremely low reversibility(<20%)in carbonate based clectrolytes-this piece of knowledge gained from previous studics has ruled out the application of carbonate solvents for sodium metal batteries.Here,we overturn this conclusion by incorporating fluoroethylene carbonate(FEC)as cosolvent that renders a Na plating/stripping fficiency of>95%with conventional NaPF。salt at a regular concentration(1.0M).The peculiar role of FEC is firstly.unraveled via its involvement into the solvation structure,where a threshold FEC concentration with a coordination number>1.2 is needed in guaranteeing high Na reversibility over the long-term.Specifially,by incorporating an average number of 1.2 FEC molecules into the primary Na*solvation sheath,lowest unoccupied molecular orbital(LUMO)levels of such Nat-FEC solvates undergo further decrease,with spin electrons residing either on the O=C 0(O)moiety of FEC or sharing between Na*and its C=:O bond,which ensures a prior FEC decomposition in passivating the Na surface against other carbonate molecules.Further,by adopting cryogenic tranmission electron microscopy(cryo-TEM),we found that the Na filaments grow into substantially larger diameter from-400nm to>1 pum with addition of FEC upon the threshold value.A.highly crstalline and much thiner(-40 nm)slid-electrolyte interphase(SED)is consequently observed to uniformly wrap the Na surface,in contrast to the severely corroded Na as retrieved from the blank electrolyte.The potence of FEC is further demonstrated in a series of"corrosive solvents"such as ethy!l acetate(EA)。trimethyl phosphate(TMP),and actonitrile(AN)enabling highly reversible SMAs in the otherwise unusable solvent systems.展开更多
Multi-Clock Snapshot Isolation(MCSI)is a concurrency control mechanism that implements snapshot isolation on a single-layer Non-Volatile Memory(NVM)database.It stores a single copy of data by using multi-version stora...Multi-Clock Snapshot Isolation(MCSI)is a concurrency control mechanism that implements snapshot isolation on a single-layer Non-Volatile Memory(NVM)database.It stores a single copy of data by using multi-version storage to ensure durability and runtime access.With multi-clock transaction timestamp assignment,MCSI can efficiently generate snapshots with vector clocks and use per-thread transaction status arrays to identify uncommitted versions in NVM.For evaluation,we compared MCSI with the PostgreSQL-style concurrency control used in the single-layer NVM database N2DB.The maximum transaction throughput of MCSI is 101%–195%higher than that of N2DB for the YCSB workloads,and 25%–49%higher for the TPC-C workloads.Moreover,the transaction latency of MCSI remains relatively stable as the thread count increases.With 18 worker threads,the average transaction latency of MCSI is 65%–84%lower than that of N2DB for the YCSB workloads and 16%–43%lower for the TPC-C workloads.展开更多
Non-Volatile Memory(NVM) offers byte-addressability and persistency. Because NVM can be plugged into memory and provide low latency, it offers a new opportunity to build new database systems with a single-layer storag...Non-Volatile Memory(NVM) offers byte-addressability and persistency. Because NVM can be plugged into memory and provide low latency, it offers a new opportunity to build new database systems with a single-layer storage design. A single-layer NVM-Native DataBase(N2 DB) provides zero copy and log freedom. Hence, all data are stored in NVM and there is no extra data duplication and logging during execution. N2 DB avoids complex data synchronization and logging overhead in the two-layer storage design of disk-oriented databases and in-memory databases. Garbage Collection(GC) is critical in such an NVM-based database because memory leaks on NVM are durable. Moreover, data recovery is equally essential to guarantee atomicity, consistency, isolation, and durability properties. Without logging, it is a great challenge for N2 DB to restore data to a consistent state after crashes and recoveries. This paper presents the GC and data recovery mechanisms for N2 DB. Evaluations show that the overall performance of N2 DB is up to 3:6 higher than that of InnoDB. Enabling GC reduces performance by up to 10%,but saves storage space by up to 67%. Moreover, our data recovery requires only 0:2% of the time and half of the storage space of InnoDB.展开更多
Unreasonable allocation of shared resources reduces the system efficiency and is a considerable operational risk.Sub-processes with insufficient portion of shared resources could not help accomplish complicated tasks,...Unreasonable allocation of shared resources reduces the system efficiency and is a considerable operational risk.Sub-processes with insufficient portion of shared resources could not help accomplish complicated tasks,and overstaffing and idle resources will occur in the sub-processes assigned with redundant shared resources.This unfair portion distribution may cause internal contradictions among sub-processes and even lead to the collapsing of the entire system.This study proposes a data-driven,mixed two-stage network data envelopment analysis model.This method aims to reasonably define the allocation portion of shared extra intermediate resources among several nonhomogeneous subsystems and measure the overall system performance.A data set of 58 international hotels is used to test the features of the proposed model.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.32072623,31700611)。
文摘Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can integrate both chlorophyll biosynthesis and flavonoid accumulation in response to specific light signals are rarely identified.In this study,we report that the GOLDEN 2-LIKE TF pair,CsGLK1 and CsGLK2,orchestrate UV-B-induced responses in the chlorophyll biosynthesis and flavonoid accumulation of tea leaves.The absence of solar UV-B reduced the transcriptional expression of CsGLKs in the tea leaves and was highly correlated with a decrease in flavonoid levels(especially flavonol glycosides)and the expression of genes and TFs involved in chlorophyll biosynthesis and flavonoid accumulation.In vivo and in vitro molecular analyses showed that CsGLKs could be regulated by the UV-B signal mediator CsHY5,and could directly bind to the promoters of gene and TF involved in light-harvesting(CsLhcb),chlorophyll biosynthesis(CsCHLH,CsHEMA1,and CsPORA),and flavonoid accumulation(CsMYB12,CsFLSa,CsDFRa,and CsLARa),eventually leading to UV-B-induced responses in the chlorophylls and flavonoids of tea leaves.Furthermore,UV-B exposure increased the levels of total flavonoids,CsGLK1 protein,and expression of CsGLKs and target genes in the tea leaves.These results indicate that CsGLKs may modulate tea leaf characteristics by regulating chlorophyll biosynthesis and flavonoid accumulation in response to solar UV-B.As the first report on UV-B-induced changes in flavonoid and chlorophyll regulation mediated by CsGLKs,this study improves our understanding of the environmental regulations regarding tea quality and sheds new light on UV-B-induced flavonoid responses in higher plants.
基金supported by the Fundamental Research Funds for the Central Universities of Ministry of Education of China(No.JB190501)Science and Technology Innovation Team of Shaanxi Province(No.2019TD-002)National Natural Science Foundation of China(No.11774277)。
文摘The applications of laser-induced breakdown spectroscopy(LIBS) on classifying complex natural organics are relatively limited and their accuracy still requires improvement.In this work,to study the methods on classification of complex organics,three kinds of fresh leaves were measured by LIBS.100 spectra from 100 samples of each kind of leaves were measured and then they were divided into a training set and a test set in a ratio of 7:3.Two algorithms of chemometric methods including the partial least squares discriminant analysis(PLS-DA) and principal component analysis Mahalanobis distance(PCA-MD) were used to identify these leaves.By using 23 lines from 16 elements or molecules as input data,these two methods can both classify these three kinds of leaves successfully.The classification accuracies of training sets are both up to 100% by PCA-MD and PLS-DA.The classification accuracies of the test set are 93.3% by PCA-MD and 97.8% by PLS-DA.It means that PLS-DA is better than PCA-MD in classifying plant leaves.Because the components in PLS-DA process are more suitable for classification than those in PCA-MD process.We think that this work can provide a reference for plant traceability using LIBS.
基金supported by Natural Science Foundation of China projects(Nos.41971011 and 41630747).
文摘Saltation bombardment is a dominate dust emission mechanism in wind erosion.For loose surfaces,splash entrainment has been well understood theoretically.However,the mass loss predictions of cohesive soils are generally empirical in most wind erosion models.In this study,the soil particle detachment of a bare,smooth,dry,and uncrusted soil surface caused by saltation bombardment is modeled by means of classical mechanics.It is shown that detachment rate can be analytically expressed in terms of the kinetic energy or mass flux of saltating grains and several common mechanical parameters of soils,including Poisson's ratio,Young's modulus,cohesion and friction angle.The novel expressions can describe dust emission rate from cohesive surfaces and are helpful to quantify the anti-erodibility of soil.It is proposed that the mechanical properties of soils should be appropriately included in physically-based wind erosion models.
基金the National Natural Science Foundation of China(32072623,31700611)the Natural Science Foundation of Anhui Province-Outstanding Youth Project(2008085J18).
文摘As the major bitter-and astringent-tasting components in tea leaves,catechins play an essential role in determining flavor characteristics and health benefits of tea products.This study analyzed the circadian rhythm effects on the accumulation pattern of catechins in tender leaves of three tea cultivars,'Huangkui'(HK),'Longjing43'(LJ43)and'Fuding Dabaicha'(FD).There were two major factors involved in the catechin regulation in tea plants:genetic background of the cultivar-specific regulation,and temporal effects of the circadian rhythm.Etiolated leaves of'HK'contained lower levels of catechins than'LJ43'and'FD'.The composition of EGCG in total catechins was significantly higher in'LJ43'leaves(65%)when compared with that in'HK'and'FD'(45%).The accumulation of individual catechins increased during the daytime but decreased overnight,especially over the time period of 22:00−02:00.The correlation analysis between catechins and environmental factors indicated catechin accumulation in tea leaves potentially resulted from a combined regulation of light and temperature.These findings provide new insights into our understanding of circadian rhythm regulation on flavor-important secondary metabolites in tea leaves.
基金This work was supported by Chinese Medicine Foundation
文摘Cigarette smoking is a main source of cyanide in human body,which can be taken as a risk factor of cataract formation.In this study,combined gas chromatography and mass spectrum(GC/MS)was used todetermine the amino acid hydantoin after the incubation of soluble humanlensγ-crystallins with cyanate.The carbamylated amino acids obtained bythis procedure are alanine and hlycine,which are N-terminal amino acids ofγ-crystallin,and leucine.The aggregate,which can be observed incarbamylatedγ_1-crystallin on SDS-PAGE,may be related to the formation of disulfide and non-disulfide covalent bonds,and it seems that Y₂and Yy-crystallins can not be aggregated to any great extend.The results in this study indicate that the GC/MS is an effective method for analyzing the carbamylation of lens proteins;y-crystallin may play a very important role in the formation of cataract associated with accumulation of cyanate in human body,such as heavy smoking.
文摘[Objectives] To study the expression of Med 19 protein in tongue cancer and its significance. [Methods] Immunohistochemical method was used to detect the expression of Med 19 protein in tongue cancer tissue and paracancerous tissue. [Results]The expression of Med19 protein in tongue cancer tissue was higher than paracancerous tissue and normal tissue. The expression of Med 19 protein was related to the tumor lymph node metastasis. However,there was no significant difference in sex,age,Tumor Node Metastasis( TNM),and differentiation degree. [Conclusions] Med 19 protein participates in incidence and development of tongue cancer and may become diagnostic indicator and therapeutic target for tongue cancer.
基金This work was supported by the Fundamental Research Funds for the Central Universities and the Institute of Carbon Neutrality of Tongji University.
文摘无水氟化铜(CuF_(2))有望成为下一代锂电池正极材料,其高比容量(528 mA h g^(−1))和高工作电压(3.55 V vs.Li/Li^(+))使得其能量密度高达1874 W h kg^(−1).然而,由于充电时铜的溶解,CuF_(2)正极容易失活,这限制了其发展.本研究采用氟化高浓电解液抑制铜的溶解,从而实现了CuF_(2)正极的可逆循环.采用氟化高浓电解液后,CuF_(2)正极的容量在30次循环后仍保有228 mA h g^(−1),是使用传统碳酸酯类电解液的电池容量的近三倍.综上,本研究提出了一种电解质工程策略,可以实现CuF_(2)正极的可逆充放电.
基金supported by the National Natural Science Foundation of China(51802224)“Shanghai Rising-Star Program”(19QA1409300)the open fund of Jiangsu Key Laboratory of Electrochemical Energy-Storage Technologies(EEST2018-3)。
文摘The recent revival of Li metal anodes(LMA)leads to a renewed interest in LMA as the ultimate choice for rechargeable lithium batteries towards high energy density.However,multiple challenges stand in the way of using LMA,of which high reactivity,dendrite growth,the difficulty of fabricating Li thin foils,and the flammability of organic liquid electrolytes are typical.Here,a writable Li metal ink(LMI)prepared by introducing biomass-derived carbon particles into molten Li is presented.Due to the significantly decreased surface tension,LMI is able to directly write on copper foils or other substrates that ultrathin Li foils with a remarkably small thickness(<10μm)can be achieved.The versatility of LMI is further demonstrated in addressing the interface issue between LMA and garnet-type solid-state electrolytes,where directly writing LMI on the garnet offers a perfect contact and enables an extremely low interfacial resistance of 6Ωcm^2,in sharp contrast to 939Ωcm^2 between the pure Li and the garnet.Due to the successful partnership with non-flammable solid-state electrolytes,ink-based technology may have a chance to bring us very close to the use of solid-state lithium metal batteries(SSLMBs)with high safety and high energy density.
基金supported by the National Key R&D Program of China(2020YFE0202200)the National Natural Science Foundation of China(82070365)the Basic Research General Program of Shenzhen(JCYJ20190807103407873)。
基金supported by ShanghaiTech University,the UK Medical Research Council(Grant No.MC_UU_12021/3 and MC_U137788471)National Natural Science Foundation of China(Grant No.31771490)。
文摘Compartmentation of enzymes via filamentation has arisen as a mechanism for the regulation of metabolism.In 2010,three groups independently reported that CTP synthase(CTPS)can assemble into a filamentous structure termed the cytoophidium.In searching for CTPS-interacting proteins,here we perform a yeast two-hybrid screening of Drosophila proteins and identify a putative CTPS-interacting protein,△~1-pyrroline-5-carboxylate synthase(P5CS).Using the Drosophila follicle cell as the in vivo model,we confirm that P5CS forms cytoophidia,which are associated with CTPS cytoophidia.Overexpression of P5CS increases the length of CTPS cytoophidia.Conversely,filamentation of CTPS affects the morphology of P5CS cytoophid ia.Finally,in vitro analyses confirm the filament-fo rming property of P5CS.Our work links CTPS with P5CS,two enzymes involved in the rate-limiting steps in pyrimidine and proline biosynthesis,respectively.
基金funded by the National Key Research and Development Program of China(2017YFB1302703)
文摘Glaucoma is the second leading cause of blindness after cataract worldwide.However,among irreversible blinding eye diseases,glaucoma is the primary cause(Liang et al.,2011).To date,most studies have indicated that glaucoma is not only an ocular disease,but also an optic nerve disease.In particular,primary open-angle glaucoma(POAG)is characterized by insidious onset,painless visual impairment,and complicated pathological mechanism,and patients with such condition require long-term follow-up.However,the underlying cause of POAG remains unclear,and there are several theories about its exact etiology.Some mechanisms have presented underlying optic nerve damage,which include the mechanical theory,vascular theory,and the in・volvement of other factors.
基金sponsored by the National Natural Science Foundation of China(NSFC Nos.21975186,51632001,and 22005334)supports from Natural Science Foundation of Beijing(grant No.Z200013).
文摘Sodium metal anodes(SMAs)sufer from extremely low reversibility(<20%)in carbonate based clectrolytes-this piece of knowledge gained from previous studics has ruled out the application of carbonate solvents for sodium metal batteries.Here,we overturn this conclusion by incorporating fluoroethylene carbonate(FEC)as cosolvent that renders a Na plating/stripping fficiency of>95%with conventional NaPF。salt at a regular concentration(1.0M).The peculiar role of FEC is firstly.unraveled via its involvement into the solvation structure,where a threshold FEC concentration with a coordination number>1.2 is needed in guaranteeing high Na reversibility over the long-term.Specifially,by incorporating an average number of 1.2 FEC molecules into the primary Na*solvation sheath,lowest unoccupied molecular orbital(LUMO)levels of such Nat-FEC solvates undergo further decrease,with spin electrons residing either on the O=C 0(O)moiety of FEC or sharing between Na*and its C=:O bond,which ensures a prior FEC decomposition in passivating the Na surface against other carbonate molecules.Further,by adopting cryogenic tranmission electron microscopy(cryo-TEM),we found that the Na filaments grow into substantially larger diameter from-400nm to>1 pum with addition of FEC upon the threshold value.A.highly crstalline and much thiner(-40 nm)slid-electrolyte interphase(SED)is consequently observed to uniformly wrap the Na surface,in contrast to the severely corroded Na as retrieved from the blank electrolyte.The potence of FEC is further demonstrated in a series of"corrosive solvents"such as ethy!l acetate(EA)。trimethyl phosphate(TMP),and actonitrile(AN)enabling highly reversible SMAs in the otherwise unusable solvent systems.
基金supported by the National Key Research&Development Program of China(No.2016YFB1000504)the National Natural Science Foundation of China(Nos.61877035,61433008,61373145,and 61572280).
文摘Multi-Clock Snapshot Isolation(MCSI)is a concurrency control mechanism that implements snapshot isolation on a single-layer Non-Volatile Memory(NVM)database.It stores a single copy of data by using multi-version storage to ensure durability and runtime access.With multi-clock transaction timestamp assignment,MCSI can efficiently generate snapshots with vector clocks and use per-thread transaction status arrays to identify uncommitted versions in NVM.For evaluation,we compared MCSI with the PostgreSQL-style concurrency control used in the single-layer NVM database N2DB.The maximum transaction throughput of MCSI is 101%–195%higher than that of N2DB for the YCSB workloads,and 25%–49%higher for the TPC-C workloads.Moreover,the transaction latency of MCSI remains relatively stable as the thread count increases.With 18 worker threads,the average transaction latency of MCSI is 65%–84%lower than that of N2DB for the YCSB workloads and 16%–43%lower for the TPC-C workloads.
基金supported by the National Key Research & Development Program of China (No. 2016YFB1000504)the National Natural Science Foundation of China (Nos. 61877035, 61433008, 61373145, and 61572280)。
文摘Non-Volatile Memory(NVM) offers byte-addressability and persistency. Because NVM can be plugged into memory and provide low latency, it offers a new opportunity to build new database systems with a single-layer storage design. A single-layer NVM-Native DataBase(N2 DB) provides zero copy and log freedom. Hence, all data are stored in NVM and there is no extra data duplication and logging during execution. N2 DB avoids complex data synchronization and logging overhead in the two-layer storage design of disk-oriented databases and in-memory databases. Garbage Collection(GC) is critical in such an NVM-based database because memory leaks on NVM are durable. Moreover, data recovery is equally essential to guarantee atomicity, consistency, isolation, and durability properties. Without logging, it is a great challenge for N2 DB to restore data to a consistent state after crashes and recoveries. This paper presents the GC and data recovery mechanisms for N2 DB. Evaluations show that the overall performance of N2 DB is up to 3:6 higher than that of InnoDB. Enabling GC reduces performance by up to 10%,but saves storage space by up to 67%. Moreover, our data recovery requires only 0:2% of the time and half of the storage space of InnoDB.
基金The research is supported by the National Natural Science Foundation of China(Grant Nos.71871223,71790615,91846301,and 71828101)Innovation-Driven Planning Foundation of Central South University(Grant No.2019CX041)Graduate Student Independent Exploration and Innovation Project of Central South University(Grant No.2019zzts922).
文摘Unreasonable allocation of shared resources reduces the system efficiency and is a considerable operational risk.Sub-processes with insufficient portion of shared resources could not help accomplish complicated tasks,and overstaffing and idle resources will occur in the sub-processes assigned with redundant shared resources.This unfair portion distribution may cause internal contradictions among sub-processes and even lead to the collapsing of the entire system.This study proposes a data-driven,mixed two-stage network data envelopment analysis model.This method aims to reasonably define the allocation portion of shared extra intermediate resources among several nonhomogeneous subsystems and measure the overall system performance.A data set of 58 international hotels is used to test the features of the proposed model.