Alzheimer's disease poses a significant global health challenge owing to the progressive cognitive decline of patients and absence of curative treatments.The current therapeutic strategies,primarily based on choli...Alzheimer's disease poses a significant global health challenge owing to the progressive cognitive decline of patients and absence of curative treatments.The current therapeutic strategies,primarily based on cholinesterase inhibitors and N-methyl-Daspartate receptor antagonists,offer limited symptomatic relief without halting disease progression,highlighting an urgent need for novel research directions that address the key mechanisms underlying Alzheimer's disease.Recent studies have provided insights into the critical role of glycolysis,a fundamental energy metabolism pathway in the brain,in the pathogenesis of Alzheimer's disease.Alterations in glycolytic processes within neurons and glial cells,including microglia,astrocytes,and oligodendrocytes,have been identified as significant contributors to the pathological landscape of Alzheimer's disease.Glycolytic changes impact neuronal health and function,thus offering promising targets for therapeutic intervention.The purpose of this review is to consolidate current knowledge on the modifications in glycolysis associated with Alzheimer's disease and explore the mechanisms by which these abnormalities contribute to disease onset and progression.Comprehensive focus on the pathways through which glycolytic dysfunction influences Alzheimer's disease pathology should provide insights into potential therapeutic targets and strategies that pave the way for groundbreaking treatments,emphasizing the importance of understanding metabolic processes in the quest for clarification and management of Alzheimer's disease.展开更多
Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins.Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular home...Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins.Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular homeostasis,while providing nutrients and support for cell survival.Chaperone-mediated autophagy activity can be detected in almost all cells,including neurons.Owing to the extreme sensitivity of neurons to their environmental changes,maintaining neuronal homeostasis is critical for neuronal growth and survival.Chaperone-mediated autophagy dysfunction is closely related to central nervous system diseases.It has been shown that neuronal damage and cell death are accompanied by chaperone-mediated autophagy dysfunction.Under certain conditions,regulation of chaperone-mediated autophagy activity attenuates neurotoxicity.In this paper,we review the changes in chaperone-mediated autophagy in neurodegenerative diseases,brain injury,glioma,and autoimmune diseases.We also summarize the most recent research progress on chaperone-mediated autophagy regulation and discuss the potential of chaperone-mediated autophagy as a therapeutic target for central nervous system diseases.展开更多
Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation.To clarify the molecular mechanisms underlying these processes,comprehensive investigati...Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation.To clarify the molecular mechanisms underlying these processes,comprehensive investigations were conducted using a cyp17a2 mutant Nile tilapia(Oreochromis niloticus) model.Analysis revealed pronounced Cyp17a2 expression in ovarian somatic cells of the tilapia.Female cyp17a2-deficient mutants exhibited markedly reduced levels of 17,20β-dihydroxy-4-pregnen-3-one(DHP) and cortisol/cortisone,leading to delayed meiotic initiation and impaired oocyte maturation and spawning.Notably,supplementation with human chorionic gonadotrophin(hCG),DHP,and cortisol effectively induced germinal vesicle breakdown(GVBD) and facilitated oocyte release with follicular cell layers in cyp17a2^(-/-)females.Additionally,cyp17a2-/-and rescued cyp17a2-/-females showed elevated transcription of steroidogenic enzymes involved in 17β-estradiol(E2)production compared to spawning wild-type females.Moreover,the reduction in Akt phosphorylation observed in cyp17a2-deficient females and upon inhibitor treatment impaired hCG-induced oocyte maturation.Conversely,activation of the phosphoinositide 3-kinase/protein kinase B(PI3K-Akt) signaling pathway partially rescued the oocyte maturation impairment caused by cyp17a2mutation.Overall,these findings provide functional evidence supporting the critical role of Cyp17a2 in DHP and cortisol biosynthesis,which,in turn,facilitates oocyte maturation and ovulation through activation of the PI3K-Akt signaling pathway in fish.展开更多
Despite dedicated effort for many decades,statistical description of highly technologically important wall turbulence remains a great challenge.Current models are unfortunately incomplete,or empirical,or qualitative.A...Despite dedicated effort for many decades,statistical description of highly technologically important wall turbulence remains a great challenge.Current models are unfortunately incomplete,or empirical,or qualitative.After a review of the existing theories of wall turbulence,we present a new framework,called the structure ensemble dynamics （SED）,which aims at integrating the turbulence dynamics into a quantitative description of the mean flow.The SED theory naturally evolves from a statistical physics understanding of non-equilibrium open systems,such as fluid turbulence, for which mean quantities are intimately coupled with the fluctuation dynamics.Starting from the ensemble-averaged Navier-Stokes（EANS） equations,the theory postulates the existence of a finite number of statistical states yielding a multi-layer picture for wall turbulence.Then,it uses order functions（ratios of terms in the mean momentum as well as energy equations） to characterize the states and transitions between states.Application of the SED analysis to an incompressible channel flow and a compressible turbulent boundary layer shows that the order functions successfully reveal the multi-layer structure for wall-bounded turbulence, which arises as a quantitative extension of the traditional view in terms of sub-layer,buffer layer,log layer and wake. Furthermore,an idea of using a set of hyperbolic functions for modeling transitions between layers is proposed for a quantitative model of order functions across the entire flow domain.We conclude that the SED provides a theoretical framework for expressing the yet-unknown effects of fluctuation structures on the mean quantities,and offers new methods to analyze experimental and simulation data.Combined with asymptotic analysis,it also offers a way to evaluate convergence of simulations.The SED approach successfully describes the dynamics at both momentum and energy levels, in contrast with all prevalent approaches describing the mean velocity profile only.Moreover,the SED theoretical framework is general,independent of the flow system to study, while the actual functional form of the order functions may vary from flow to flow.We assert that as the knowledge of order functions is accumulated and as more flows are analyzed, new principles（such as hierarchy,symmetry,group invariance,etc.） governing the role of turbulent structures in the mean flow properties will be clarified and a viable theory of turbulence might emerge.展开更多
In this study,a waveform modification method was proposed using a self-designed heating device combined with the split Hopkinson pressure bar(SHPB)technique for determination of dynamic behaviors of rock at high tempe...In this study,a waveform modification method was proposed using a self-designed heating device combined with the split Hopkinson pressure bar(SHPB)technique for determination of dynamic behaviors of rock at high temperature.Firstly,the temperature gradient distribution on the incident bar was measured according to the variation of elastic modulus of the bar with temperature,and the relationship between the longitudinal wave velocity and temperature of the bar was obtained based on onedimensional stress wave theory.The incident bar with a temperature gradient was divided into a series of microelements,and then the transmission coefficient of the whole incident bar was obtained.Finally,the stress wave was modified by the transmission coefficient from 25℃ to 600℃.This method was used to study the dynamic properties of rock at high temperature,which not only preserves a classical SHPB device,but also effectively ensures the accuracy of the experimental results.A dynamic Brazilian disc experiment was carried out to explore the influences of loading rate and temperature on dynamic tensile strength of sandstone at high temperature using the proposed waveform modification method.展开更多
Roasting is a common manufacture technology for processing various teas.It is not only used in decreasing the water content of finished tea,but also improving the flavor of teas.In the present study,the roasted and no...Roasting is a common manufacture technology for processing various teas.It is not only used in decreasing the water content of finished tea,but also improving the flavor of teas.In the present study,the roasted and non-roasted teas were compared by liquid-chromatography mass spectrometry and sensory evaluation.The roasted tea tasted less bitter and astringent.The content of main galloylated and simple catechins,caffeine and theobromine in roasted were significantly lower than non-roasted teas.Targeted taste-compounds metabolomics revealed that(-)-epigallocatechin gallate,kaempferol-glucose-rhamnose-glucose and(-)-epicatechin gallate were main contributors tightly correlated to astringent intensity.Flavonol glycosides including kaempferol-glucose,quercetin-glucose,kaempferol-glucose-rhamnose-glucose,and quercetin-glucose-rhamnose-glucose in roasted teas were also significantly less than non-roasted teas.To study the chemical changes during roasting,tea with a strong astringency was roasted under 80,100,120,140,and 160°C.With the increase of roasting temperature,the bitter and astringent intensity of tea was gradually decreased,but the main astringent compounds including(-)-epigallocatechin,(-)-epigallocatechin gallate and kaempferol/quercetin glycosides were irregularly varied with temperature.The Pearson correlation coefficient analysis suggested procyanidin B2,coumaroylquinic acids and gallotannins were tightly correlated to the astringent and bitter perceptions,while N-ethyl-2-pyrrolidonesubstituted flavan-3-ols were negatively correlated.展开更多
To investigate the influence of loading rate and high temperature on the dynamic fracture toughness of rock,dynamic fracture tests were carried out on notched semi-circular bend specimens under four temperature condit...To investigate the influence of loading rate and high temperature on the dynamic fracture toughness of rock,dynamic fracture tests were carried out on notched semi-circular bend specimens under four temperature conditions based on the split Hopkinson pressure bar system.Experimental and analytical methods were applied to investigating the effect of temperature gradient on the stress waves.A high-speed camera was used to check the fracture characteristics of the specimens.The results demonstrate that the temperature gradient on the bars will not significantly distort the shape of the stress wave.The dynamic force balance is achieved even when the specimens are at a temperature of 400°C.The dynamic fracture toughness linearly develops with the increase of loading rate within the temperature range of 25-400°C,and high temperature has a strengthening effect on the dynamic fracture toughness.展开更多
Larger-leaf yellow tea(LYT)is a characteristic type of Chinese tea produced in Huoshan County,Anhui Province,which is made by mature leaves with stems.According to recent report,LYT showed competitive effects in anti-...Larger-leaf yellow tea(LYT)is a characteristic type of Chinese tea produced in Huoshan County,Anhui Province,which is made by mature leaves with stems.According to recent report,LYT showed competitive effects in anti-hyperglycemia in comparison to other teas such as green or black tea.However,the bioactive compounds of LYT are still undiscovered so far.For this purpose,5 fractions of LYT were prepared by sequential extraction.The in vitro bioassay results indicated that the ethyl acetate fraction of LYT had the strongest inhibitory effects onα-glucosidase andα-amylase.Fluorescence-quenching analysis and proteinbinding test revealed that the compounds of ethyl acetate fraction could inhibitα-glucosidase andα-amylase activities through binding to enzymes or other mechanisms.All chromatographic peaks of high-performance liquid chromatography(HPLC)of ethyl acetate fraction were separated and collected.The purified compounds were identified by liquid chromatography-mass spectrometry(LC-MS),and subsequently screened by calculating their inhibition ratio onα-glucosidase at the real concentration in LYT infusion.The results showed that(-)-epigallocatechin gallate,(-)-gallocatechin gallate,caffeine,N-ethyl-2-pyrrolidone-substituted flavan-3-ols were effective inhibitors forα-glucosidase.展开更多
Ultraviolet(UV) photodetectors based on wide band gap semiconductor have attracted much attention for their small volume, low working voltage, long lifetime, good chemical and thermal stability. Up to now, many resear...Ultraviolet(UV) photodetectors based on wide band gap semiconductor have attracted much attention for their small volume, low working voltage, long lifetime, good chemical and thermal stability. Up to now, many researches have been done on the semiconductors based UV detectors and some kinds of detectors have been made, such as metal–semiconductor–metal(MSM), Schottky, and PIN-type detectors. However, the sensitivity values of those detectors are still far from the expectation. Recent years, surface plasmon(SP) has been considered to be an effective way to enhance the sensitivity of semiconductor based UV photodetector. When the light is matched with the resonance frequency of surface plasmon, the localized field enhancement or scattering effect will happen and thus the spectral response will be enhanced.Here, we present an overview of surface plasmon enhancing the performance of UV detectors, including the GaN, ZnO,and other wide band gap semiconductor UV detectors. Both fundamental and experimental achievements are contained in this review.展开更多
Since the outbreak of the COVID-19 pandemic,under the strong leadership of the Central Committee of the Communist Party of China and President Xi Jinping,China has made firm decisions to prioritize people's lives ...Since the outbreak of the COVID-19 pandemic,under the strong leadership of the Central Committee of the Communist Party of China and President Xi Jinping,China has made firm decisions to prioritize people's lives and health.Efforts have been made to avoid foreign imported infection and domestic rebound of COVID-19 cases;the“dynamic zero COVID”policy has been executed without wavering;and the prevention and control measures have been optimized and improved in response to changing circumstances,actively responding to the impact caused by multiple waves of COVID-19 surge globally.China has made extraordinary efforts to safeguard people's lives and health.Meanwhile,prevention and control measures were timely updated to coordinate with economic and social development.On November 10,the Standing Committee of the Central Political Bureau held a meeting to discuss the latest situation of the COVID-19 pandemic in China.Twenty measures(referred to as“the 20-point measures”)were officially announced to further optimize the COVID-19 response.The latest prevention and control measures involve the requirements and guidance for isolation at home,high-risk area delineation,nucleic acid testing,international inbound flights and travelers,vaccination rollout,medical resource preparedness,and protection for special places and vulnerable population.展开更多
On November 11,2022,the Chinese government released the Scientific and Targeted Prevention and Control Measures to Optimize COVID-19 Response.Since that time,adjusted measures have been implemented throughout China,le...On November 11,2022,the Chinese government released the Scientific and Targeted Prevention and Control Measures to Optimize COVID-19 Response.Since that time,adjusted measures have been implemented throughout China,leading to major shifts in implementation of the national prevention and control strategy.On the basis of the current situation of the epidemic and the evolving SARS-Cov-2 variants,an additional 10 specifications(referred to as“the 10-point measures”)were officially released on December 7,2022,in an effort to further optimize the prevention and control measures.The latest adjustments pertain to the specification of:precise delineation of high-risk areas,nucleic acid testing scheme,isolation and health monitoring,restriction and lifting of high-risk areas,medicine supply,vaccination rollout among older people,health status of key populations,social functioning,and campus response.展开更多
基金supported by the National Natural Science Foundation of China,No.82271214(to ZY)the Natural Science Foundation of Hubei Province of China,No.2022CFB109(to ZY)。
文摘Alzheimer's disease poses a significant global health challenge owing to the progressive cognitive decline of patients and absence of curative treatments.The current therapeutic strategies,primarily based on cholinesterase inhibitors and N-methyl-Daspartate receptor antagonists,offer limited symptomatic relief without halting disease progression,highlighting an urgent need for novel research directions that address the key mechanisms underlying Alzheimer's disease.Recent studies have provided insights into the critical role of glycolysis,a fundamental energy metabolism pathway in the brain,in the pathogenesis of Alzheimer's disease.Alterations in glycolytic processes within neurons and glial cells,including microglia,astrocytes,and oligodendrocytes,have been identified as significant contributors to the pathological landscape of Alzheimer's disease.Glycolytic changes impact neuronal health and function,thus offering promising targets for therapeutic intervention.The purpose of this review is to consolidate current knowledge on the modifications in glycolysis associated with Alzheimer's disease and explore the mechanisms by which these abnormalities contribute to disease onset and progression.Comprehensive focus on the pathways through which glycolytic dysfunction influences Alzheimer's disease pathology should provide insights into potential therapeutic targets and strategies that pave the way for groundbreaking treatments,emphasizing the importance of understanding metabolic processes in the quest for clarification and management of Alzheimer's disease.
基金supported by the National Nature Science Foundation of China,Nos.81871603(to XZ)and 82171322(to ZF)Discipline Boost Program of the First Affiliated Hospital of Air Force Military Medical University,No.XJZT21J08(to XZ)the Natural Science Foundation of Shaanxi Province of China,No.2022KJXX-102(to ZF)。
文摘Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins.Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular homeostasis,while providing nutrients and support for cell survival.Chaperone-mediated autophagy activity can be detected in almost all cells,including neurons.Owing to the extreme sensitivity of neurons to their environmental changes,maintaining neuronal homeostasis is critical for neuronal growth and survival.Chaperone-mediated autophagy dysfunction is closely related to central nervous system diseases.It has been shown that neuronal damage and cell death are accompanied by chaperone-mediated autophagy dysfunction.Under certain conditions,regulation of chaperone-mediated autophagy activity attenuates neurotoxicity.In this paper,we review the changes in chaperone-mediated autophagy in neurodegenerative diseases,brain injury,glioma,and autoimmune diseases.We also summarize the most recent research progress on chaperone-mediated autophagy regulation and discuss the potential of chaperone-mediated autophagy as a therapeutic target for central nervous system diseases.
基金supported by the National Key Research and Development Program of China (2022YFD2401800)National Natural Science Foundation of China (32403005, 32293253, 32072957)+1 种基金Chongqing Science and Technology Commission (cstc2021jcyjmsxm X0088)Fundamental Research Funds for the Central Universities (SWU-KQ22026)。
文摘Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation.To clarify the molecular mechanisms underlying these processes,comprehensive investigations were conducted using a cyp17a2 mutant Nile tilapia(Oreochromis niloticus) model.Analysis revealed pronounced Cyp17a2 expression in ovarian somatic cells of the tilapia.Female cyp17a2-deficient mutants exhibited markedly reduced levels of 17,20β-dihydroxy-4-pregnen-3-one(DHP) and cortisol/cortisone,leading to delayed meiotic initiation and impaired oocyte maturation and spawning.Notably,supplementation with human chorionic gonadotrophin(hCG),DHP,and cortisol effectively induced germinal vesicle breakdown(GVBD) and facilitated oocyte release with follicular cell layers in cyp17a2^(-/-)females.Additionally,cyp17a2-/-and rescued cyp17a2-/-females showed elevated transcription of steroidogenic enzymes involved in 17β-estradiol(E2)production compared to spawning wild-type females.Moreover,the reduction in Akt phosphorylation observed in cyp17a2-deficient females and upon inhibitor treatment impaired hCG-induced oocyte maturation.Conversely,activation of the phosphoinositide 3-kinase/protein kinase B(PI3K-Akt) signaling pathway partially rescued the oocyte maturation impairment caused by cyp17a2mutation.Overall,these findings provide functional evidence supporting the critical role of Cyp17a2 in DHP and cortisol biosynthesis,which,in turn,facilitates oocyte maturation and ovulation through activation of the PI3K-Akt signaling pathway in fish.
基金supported by the National Natural Science Foundation of China(90716008)the National Basic Research Program of China(2009CB724100).
文摘Despite dedicated effort for many decades,statistical description of highly technologically important wall turbulence remains a great challenge.Current models are unfortunately incomplete,or empirical,or qualitative.After a review of the existing theories of wall turbulence,we present a new framework,called the structure ensemble dynamics （SED）,which aims at integrating the turbulence dynamics into a quantitative description of the mean flow.The SED theory naturally evolves from a statistical physics understanding of non-equilibrium open systems,such as fluid turbulence, for which mean quantities are intimately coupled with the fluctuation dynamics.Starting from the ensemble-averaged Navier-Stokes（EANS） equations,the theory postulates the existence of a finite number of statistical states yielding a multi-layer picture for wall turbulence.Then,it uses order functions（ratios of terms in the mean momentum as well as energy equations） to characterize the states and transitions between states.Application of the SED analysis to an incompressible channel flow and a compressible turbulent boundary layer shows that the order functions successfully reveal the multi-layer structure for wall-bounded turbulence, which arises as a quantitative extension of the traditional view in terms of sub-layer,buffer layer,log layer and wake. Furthermore,an idea of using a set of hyperbolic functions for modeling transitions between layers is proposed for a quantitative model of order functions across the entire flow domain.We conclude that the SED provides a theoretical framework for expressing the yet-unknown effects of fluctuation structures on the mean quantities,and offers new methods to analyze experimental and simulation data.Combined with asymptotic analysis,it also offers a way to evaluate convergence of simulations.The SED approach successfully describes the dynamics at both momentum and energy levels, in contrast with all prevalent approaches describing the mean velocity profile only.Moreover,the SED theoretical framework is general,independent of the flow system to study, while the actual functional form of the order functions may vary from flow to flow.We assert that as the knowledge of order functions is accumulated and as more flows are analyzed, new principles（such as hierarchy,symmetry,group invariance,etc.） governing the role of turbulent structures in the mean flow properties will be clarified and a viable theory of turbulence might emerge.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41972283 and 51774325)。
文摘In this study,a waveform modification method was proposed using a self-designed heating device combined with the split Hopkinson pressure bar(SHPB)technique for determination of dynamic behaviors of rock at high temperature.Firstly,the temperature gradient distribution on the incident bar was measured according to the variation of elastic modulus of the bar with temperature,and the relationship between the longitudinal wave velocity and temperature of the bar was obtained based on onedimensional stress wave theory.The incident bar with a temperature gradient was divided into a series of microelements,and then the transmission coefficient of the whole incident bar was obtained.Finally,the stress wave was modified by the transmission coefficient from 25℃ to 600℃.This method was used to study the dynamic properties of rock at high temperature,which not only preserves a classical SHPB device,but also effectively ensures the accuracy of the experimental results.A dynamic Brazilian disc experiment was carried out to explore the influences of loading rate and temperature on dynamic tensile strength of sandstone at high temperature using the proposed waveform modification method.
基金supported by Natural Science Foundation of China(32072633,32072634,31201335)earmarked fund for China Agriculture Research System(CARS-19)+1 种基金Anhui Key research and development plan(1804b06020367,202004b11020004)Young Elite Scientist Sponsorship Program by National CAST(2016QNRC001)。
文摘Roasting is a common manufacture technology for processing various teas.It is not only used in decreasing the water content of finished tea,but also improving the flavor of teas.In the present study,the roasted and non-roasted teas were compared by liquid-chromatography mass spectrometry and sensory evaluation.The roasted tea tasted less bitter and astringent.The content of main galloylated and simple catechins,caffeine and theobromine in roasted were significantly lower than non-roasted teas.Targeted taste-compounds metabolomics revealed that(-)-epigallocatechin gallate,kaempferol-glucose-rhamnose-glucose and(-)-epicatechin gallate were main contributors tightly correlated to astringent intensity.Flavonol glycosides including kaempferol-glucose,quercetin-glucose,kaempferol-glucose-rhamnose-glucose,and quercetin-glucose-rhamnose-glucose in roasted teas were also significantly less than non-roasted teas.To study the chemical changes during roasting,tea with a strong astringency was roasted under 80,100,120,140,and 160°C.With the increase of roasting temperature,the bitter and astringent intensity of tea was gradually decreased,but the main astringent compounds including(-)-epigallocatechin,(-)-epigallocatechin gallate and kaempferol/quercetin glycosides were irregularly varied with temperature.The Pearson correlation coefficient analysis suggested procyanidin B2,coumaroylquinic acids and gallotannins were tightly correlated to the astringent and bitter perceptions,while N-ethyl-2-pyrrolidonesubstituted flavan-3-ols were negatively correlated.
基金support from the National Natural Science Foundation of China(No.41972283)。
文摘To investigate the influence of loading rate and high temperature on the dynamic fracture toughness of rock,dynamic fracture tests were carried out on notched semi-circular bend specimens under four temperature conditions based on the split Hopkinson pressure bar system.Experimental and analytical methods were applied to investigating the effect of temperature gradient on the stress waves.A high-speed camera was used to check the fracture characteristics of the specimens.The results demonstrate that the temperature gradient on the bars will not significantly distort the shape of the stress wave.The dynamic force balance is achieved even when the specimens are at a temperature of 400°C.The dynamic fracture toughness linearly develops with the increase of loading rate within the temperature range of 25-400°C,and high temperature has a strengthening effect on the dynamic fracture toughness.
基金supported by Natural Science Foundation of China(32072633,32072634,31201335)earmarked fund for China Agriculture Research System(CARS-19)+1 种基金Anhui Key research and development plan(1804b06020367,202004b11020004)Young Elite Scientist Sponsorship Program by National CAST(2016QNRC001)。
文摘Larger-leaf yellow tea(LYT)is a characteristic type of Chinese tea produced in Huoshan County,Anhui Province,which is made by mature leaves with stems.According to recent report,LYT showed competitive effects in anti-hyperglycemia in comparison to other teas such as green or black tea.However,the bioactive compounds of LYT are still undiscovered so far.For this purpose,5 fractions of LYT were prepared by sequential extraction.The in vitro bioassay results indicated that the ethyl acetate fraction of LYT had the strongest inhibitory effects onα-glucosidase andα-amylase.Fluorescence-quenching analysis and proteinbinding test revealed that the compounds of ethyl acetate fraction could inhibitα-glucosidase andα-amylase activities through binding to enzymes or other mechanisms.All chromatographic peaks of high-performance liquid chromatography(HPLC)of ethyl acetate fraction were separated and collected.The purified compounds were identified by liquid chromatography-mass spectrometry(LC-MS),and subsequently screened by calculating their inhibition ratio onα-glucosidase at the real concentration in LYT infusion.The results showed that(-)-epigallocatechin gallate,(-)-gallocatechin gallate,caffeine,N-ethyl-2-pyrrolidone-substituted flavan-3-ols were effective inhibitors forα-glucosidase.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0400904)the National Natural Science Foundation for Distinguished Young Scholars,China(Grant No.61725403)+5 种基金the National Natural Science Foundation of China(Grant Nos.61574142,61322406,61704171,and 11705206)the Key Program of International Partnership Program of the Chinese Academy of Sciences(Grant No.181722KYSB20160015)the Special Project for Inter-government Collaboration of State Key Research and Development Program,China(Grant No.2016YFE0118400)the Science and Technology Service Network Initiative of the Chinese Academy of Sciences,the Jilin Provincial Science&Technology Department,China(Grant No.20180201026GX)the Interdisciplinary Innovation Team of the Chinese Academy of Sciencesthe Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2015171)
文摘Ultraviolet(UV) photodetectors based on wide band gap semiconductor have attracted much attention for their small volume, low working voltage, long lifetime, good chemical and thermal stability. Up to now, many researches have been done on the semiconductors based UV detectors and some kinds of detectors have been made, such as metal–semiconductor–metal(MSM), Schottky, and PIN-type detectors. However, the sensitivity values of those detectors are still far from the expectation. Recent years, surface plasmon(SP) has been considered to be an effective way to enhance the sensitivity of semiconductor based UV photodetector. When the light is matched with the resonance frequency of surface plasmon, the localized field enhancement or scattering effect will happen and thus the spectral response will be enhanced.Here, we present an overview of surface plasmon enhancing the performance of UV detectors, including the GaN, ZnO,and other wide band gap semiconductor UV detectors. Both fundamental and experimental achievements are contained in this review.
文摘Since the outbreak of the COVID-19 pandemic,under the strong leadership of the Central Committee of the Communist Party of China and President Xi Jinping,China has made firm decisions to prioritize people's lives and health.Efforts have been made to avoid foreign imported infection and domestic rebound of COVID-19 cases;the“dynamic zero COVID”policy has been executed without wavering;and the prevention and control measures have been optimized and improved in response to changing circumstances,actively responding to the impact caused by multiple waves of COVID-19 surge globally.China has made extraordinary efforts to safeguard people's lives and health.Meanwhile,prevention and control measures were timely updated to coordinate with economic and social development.On November 10,the Standing Committee of the Central Political Bureau held a meeting to discuss the latest situation of the COVID-19 pandemic in China.Twenty measures(referred to as“the 20-point measures”)were officially announced to further optimize the COVID-19 response.The latest prevention and control measures involve the requirements and guidance for isolation at home,high-risk area delineation,nucleic acid testing,international inbound flights and travelers,vaccination rollout,medical resource preparedness,and protection for special places and vulnerable population.
文摘On November 11,2022,the Chinese government released the Scientific and Targeted Prevention and Control Measures to Optimize COVID-19 Response.Since that time,adjusted measures have been implemented throughout China,leading to major shifts in implementation of the national prevention and control strategy.On the basis of the current situation of the epidemic and the evolving SARS-Cov-2 variants,an additional 10 specifications(referred to as“the 10-point measures”)were officially released on December 7,2022,in an effort to further optimize the prevention and control measures.The latest adjustments pertain to the specification of:precise delineation of high-risk areas,nucleic acid testing scheme,isolation and health monitoring,restriction and lifting of high-risk areas,medicine supply,vaccination rollout among older people,health status of key populations,social functioning,and campus response.
