[Objectives]To study the protective effect and mechanism of n-butanol extract of Diploclisia glaucescens(B1.)Diels on rats with adjuvant arthritis.[Methods]A rat adjuvant arthritis(AA)model with similarities to a clin...[Objectives]To study the protective effect and mechanism of n-butanol extract of Diploclisia glaucescens(B1.)Diels on rats with adjuvant arthritis.[Methods]A rat adjuvant arthritis(AA)model with similarities to a clinical RA(rheumatoid arthritis)patient was used,and the model was made by injection of Complete Freund s adjuvant(CFA).Body mass and joint swelling degree were used as indicators,and the organ index was calculated and the synovial tissue of rats was examined under microscope to evaluate the protective effect of n-butanol extract on arthritis.The effects of n-butanol extract on TNF-α,IL-1βand PGE_(2)contents in rat serum were detected by ELISA kit.[Results]Arthritic rats experienced significant weight loss;the n-butanol extract reduced the joint swelling in rats.It exerted an effect on rat organs and reduced the contents of TNF-α,IL-1βand PGE_(2) in rat serum,and also reduced synovial inflammation in rats.[Conclusions]The n-butanol extract of D.glaucescens can protect rats with adjuvant arthritis by reducing the content of inflammatory factors.展开更多
Lithium metal anode is a promising electrode with high theoretical specific capacity and low electrode potential.However,its unstable interface and low Coulombic efficiency,resulting from the dendritic growth of lithi...Lithium metal anode is a promising electrode with high theoretical specific capacity and low electrode potential.However,its unstable interface and low Coulombic efficiency,resulting from the dendritic growth of lithium,limits its commercial application.PIM-1(PIM:polymer of intrinsic microporosity),which is a polymer with abundant micropores,exhibits high rigidity and flexibility with contorted spirocenters in the backbone,and is an ideal candidate for artificial solid electrolyte interphases(SEI).In this work,a PIM-1 membrane was synthesized and fabricated as a protective membrane on the surface of an electrode to facilitate the uniform flux of Li ions and act as a stable interface for the lithium plating/stripping process.Nodule-like lithium with rounded edges was observed under the PIM-1 membrane.The Li@PIM-1 electrode delivered a high average Coulombic efficiency(99.7%),excellent cyclability(80%capacity retention rate after 600 cycles at 1 C),and superior rate capability(125.3 m Ah g-1 at 10 C).Electrochemical impedance spectrum(EIS)showed that the PIM-1 membrane could lower the diffusion rate of Li+significantly and change the rate-determining step from charge transfer to Li+diffusion.Thus,the PIM-1 membrane is proven to act as an artificial SEI to facilitate uniform and stable deposition of lithium,in favor of obtaining a compact and dense Li-plating pattern.This work extends the application of PIMs in the field of lithium batteries and provides ideas for the construction of artificial SEI.展开更多
[Objectives]To optimize the extraction process of polysaccharide in Embelia parviflora Wall.by response surface methodology,and to study the antioxidant activity in vitro of polysaccharide in E.parviflora,so as to pro...[Objectives]To optimize the extraction process of polysaccharide in Embelia parviflora Wall.by response surface methodology,and to study the antioxidant activity in vitro of polysaccharide in E.parviflora,so as to provide a basis for the further development and utilization of E.parviflora.[Methods]The solid-to-liquid ratio,extraction temperature,extraction time and extraction times were used as single factors to investigate the effects.On this basis,the response surface methodology(RSM)was used to optimize the extraction process of polysaccharide in E.parviflora.DPPH and ABTS free radicals were used to investigate the antioxidant capacity of polysaccharide in E.parviflora.[Results]The optimal solid-to-liquid ratio for extraction of polysaccharide from E.parviflora was 32∶1(mL/g),extraction temperature was 77℃,and extraction time was 36 min.The IC50 values of DPPH and ABTS were 0.04 and 0.03 mg/mL,respectively.[Conclusions]The optimized extraction process of polysaccharide in E.parviflora is stable,the extraction rate is high,and has strong antioxidant activity.It is expected to provide a reference for the industrial extraction of polysaccharide from E.parviflora.展开更多
Experiments were carried out to study the effects of nitrification inhibitors (NI) on the transformation of soil nitrogen (N) in purple soil and the effects on the N accumulation in different organs of citrus seedling...Experiments were carried out to study the effects of nitrification inhibitors (NI) on the transformation of soil nitrogen (N) in purple soil and the effects on the N accumulation in different organs of citrus seedlings. In incubation and pot experiments, the rate of nitrification inhibitors 2-chloro-6-trichloro-methyl pyridine (Nitrapyrin), 3,4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD) was 2.4%, 1.0% and 5.0% of N rate, respectively. The trend of different nitrification inhibitors on ammonium nitrogen ( NH+4-N ), nitrate nitrogen ( NO-3-N ) content and pH was compared in incubation experiment;and the effect of different NI on the dry matter quality, N uptake of citrus seedling was studied in pot experiment. The results showed that NI could significantly inhibit soil nitrification in the early culture period (p DMPP > En (calculated as nitrogen application rate). Application of NI increased the height and dry matter accumulation, N accumulation of citrus seedling grown in pot experiment. Thus, application of NI would be helpful for improving N use efficiency in purple soil which is one of major soil types for citrus production in China.展开更多
[Objectives]To establish the quality control method of Dujieqing pills.[Methods]Tangerine peel and Panax notoginseng in Dujieqing pills were qualitatively identified by thin layer chromatography(TLC).The content of he...[Objectives]To establish the quality control method of Dujieqing pills.[Methods]Tangerine peel and Panax notoginseng in Dujieqing pills were qualitatively identified by thin layer chromatography(TLC).The content of hesperidin and ginsenoside Rb1 was determined by HPLC.The acetonitrile-aqueous solution was used as mobile phase for gradient elution,the detection wavelength was 203 nm,the flow rate was 1.0 mL/min,the column temperature was 25℃,and the injection volume was 10μL.[Results]Under TLC,tangerine peel and P.notoginseng had clear chromatographic spots,good separation effect,and strong specificity and negative samples showed no interference;there was a good linear relationship between hesperidin and ginsenoside Rb1 in the range of 0.838-8.38μg(R2=0.9994)and 0.44-4.4μg(R2=0.9994),respectively;the average recovery(n=9)was 98.90%(RSD=2.31%)and 98.31%(RSD=2.56%),respectively.[Conclusions]The established quality control method is simple,reproducible,accurate and reliable,and can be used for the quality control of Dujieqing pills.展开更多
[Objectives] To establish a method for the determination of active components in toad skin. [Methods] HPLC method was used to determine the content of five active components (bufotalin, cinobufotalin, bufalin, cinobuf...[Objectives] To establish a method for the determination of active components in toad skin. [Methods] HPLC method was used to determine the content of five active components (bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin) in toad skin. [Results] Chromatographic conditions are as follows: Agilent ZORBAX SB-C 18 chromatographic column was used;acetonitrile (A)-0.3% glacial acetic acid (B) gradient elution (0-15 min, 28%A-54%A;15-35 min, 54%A-54%A) was conducted;the flow rate was 0.6 mL/min;the detection wavelength was 296 nm;the column temperature was 30 ℃;the sample size was 10 μL. Under the above conditions, the determination method of the five components can be established at one time. [Conclusions] The method was stable and reliable, and can provide experimental basis for the development and utilization of active ingredients in toad skin.展开更多
Lakes are important ecological water sources in the Bashang Plateau. Its expansion or shrinkage directly affects the ecological security of the plateau and its surrounding areas. In this study, Landsat images from 198...Lakes are important ecological water sources in the Bashang Plateau. Its expansion or shrinkage directly affects the ecological security of the plateau and its surrounding areas. In this study, Landsat images from 1984 to 2015 were selected to monitor the area of lakes in the Bashang Plateau and to analyze the spatiotemporal evolution and driving forces of lakes in the Bashang Plateau. The results showed that there were 47 lakes in the Bashang Plateau in 2015, with a total area of 37.63 km2, mainly distributed in the central and western regions of the region. From 1984 to 2015, the lakes in Bashang Plateau showed a shrinking trend. At the same time, there are obvious stage differences in lake changes. During 1984-1996, the number of lakes increased by 99 and the total area increased by 124.43 km2. From 1996 to 2015, the number of lakes decreased by 142, and the total area decreased by 183.96 km2. Before 1996, climate change was the dominant factor. However, the shrinkage of lakes after 1996 is the result of climate change and human activities. Among them, the large-scale planting of water consuming crops such as vegetables is the main human activity mode leading to lake shrinkage. This study will help to understand the expansion and contraction factors of the Bashang Plateau lakes in Hebei province and provide a reference for the future protection and management of the lakes.展开更多
Some deep-sea microbes may incorporate inorganic carbon to reduce CO_(2) emission to upper layer and atmosphere.How the microbial inhabitants can be affected under addition of bicarbonate has not been studied using in...Some deep-sea microbes may incorporate inorganic carbon to reduce CO_(2) emission to upper layer and atmosphere.How the microbial inhabitants can be affected under addition of bicarbonate has not been studied using in situ fixed and lysed samples.In this study,we cultivated 40 L natural bottom water at~1000 m depth with a final concentration of 0.1 mmol/L bicarbonate for 40 min and applied multiple in situ nucleic acids collection(MISNAC)apparatus for nucleic acids extraction from the cultivation.Our classification result of the cultivation sample showed a distinct microbial community structure,compared with the samples obtained by Niskin bottle and six working units of MISNAC.Except for notable enrichment of Alteromonas,we detected prevalence of Asprobacter,Ilumatobacter and Saccharimonadales in the cultivation.Deep-sea lineages of Euryarchaeota,SAR406,SAR202 and SAR324 were almost completely absent from the cultivation and Niskin samples.This study revealed the dominant microbes affected by bicarbonate addition and Niskin sampling,which suggested rapid responses of deep-sea microbes to the environmental changes.展开更多
The molar heat capacities(C_p) of guaiacol(CAS 90-50-1) and acetyl guaiacol ester(AGE, CAS 613-70-7) were determinated from 290 K to 350 K by differential scanning calorimetry(DSC), and expressed as a function of temp...The molar heat capacities(C_p) of guaiacol(CAS 90-50-1) and acetyl guaiacol ester(AGE, CAS 613-70-7) were determinated from 290 K to 350 K by differential scanning calorimetry(DSC), and expressed as a function of temperature. Two kinds of group contribution models were used to estimate the molar heat capacities of both guaiacol and AGE, the average relative deviation is less than 10%. The standard molar enthalpies of combustion of guaiacol and AGE were- 3590.0 k J·mol^(-1)and- 4522.1 k J·mol^(-1) by a precise thermal isolation Oxygen Bomb Calorimeter. The standard molar enthalpies of formation of guaiacol and AGE in a liquid state at298.15 K were calculated to be- 307.95 k J·mol^(-1) and- 448.72 k J·mol^(-1), respectively, based on the standard molar enthalpies of combustion. The thermodynamic properties are useful for exploiting the new synthesis method, engineering design and industry production of AGE using guaiacol as a raw material.展开更多
E-commerce is a typical form of retail digitalization that introduces online uncertainty and product returns.To decrease the negative influence of online uncertainty,the largest Chinese e-commerce company,the Alibaba ...E-commerce is a typical form of retail digitalization that introduces online uncertainty and product returns.To decrease the negative influence of online uncertainty,the largest Chinese e-commerce company,the Alibaba Group,invited an insurance company to develop return-freight insurance(RFI),a new kind of insurance,to compensate for consumers'losses in the event of online product returns.Complimentary RFl can increase consumer confidence in the retailer and attract more demand.Retailers who offer complimentary RFI demonstrate to consumers that their products and services are too good to incur excessive product returns.However,some low-quality online retailers can mimic competitors'behavior by offering complimentary RFI to consumers.This study aims to introduce an innovative online return policy based on RFI and to explore whether lowquality online retailers would use complimentary RFI as their return strategy to mislead consumers.Using signaling theory,we built a conceptual economic model that includes three exogenous pricing variables:RF,insurance premium,and compensation.These variables play different roles in the model because consumers cannot observe the insurance premium,but the compensation can be.The main finding of this study is that innovative complimentary RFI could be abused by low-type retailers when the premium and compensation are appropriate.Interestingly,compensation plays different roles for retailers with different product values:low-type retailers use complimentary RFI as a noise tool.When the product works for the consumer and the insurance profit is not too high,the compensation for the low-quality product should be larger than that for the highquality product,which is different from conventional wisdom.Although high-type online retailers may use complimentary RFl as a product quality signal,there is still a significant risk that nefarious elements will use it to create product quality noise.展开更多
The long non-coding RNA,Negative Regulator of Antiviral Response(NRAV)has been identified as a participant in both respiratory virus replication and immune checkpoints,however,its involvement in pan-cancer immune regu...The long non-coding RNA,Negative Regulator of Antiviral Response(NRAV)has been identified as a participant in both respiratory virus replication and immune checkpoints,however,its involvement in pan-cancer immune regulation and prognosis,particularly those of hepatocellular carcinoma(HCC),remains unclear.To address this knowledge gap,we analyzed expression profiles obtained from The Cancer Genome Atlas(TCGA)database,comparing normal and malignant tumor tissues.We found that NRAV expression is significantly upregulated in tumor tissues compared to adjacent nontumor tissues.Kaplan-Meier(K-M)analysis revealed the prognostic power of NRAV,wherein overexpression was significantly linked to reduced overall survival in a diverse range of tumor patients.Furthermore,noteworthy associations were observed between NRAV,immune checkpoints,immune cell infiltration,genes related to autophagy,epithelial-mesenchymal transition(EMT),pyroptosis,tumor mutational burden(TMB),and microsatellite instability(MSI)across different cancer types,including HCC.Moreover,NRAV upregulation expression was associated with multiple pathological stages by clinical observations.Furthermore,our investigation revealed a substantial elevation in the expression of NRAV in both HCC tumor tissues and cells compared to normal tissues and cells.The inhibition of NRAV resulted in the inhibition of cell proliferation,migration,and invasion in HCC cells,while also influencing the expression of CD274(PD-L1)and CD44,along with various biomarkers associated with EMT,autophagy,and pyroptosis.The aforementioned results propose NRAV as a promising prognostic biomarker for HCC.展开更多
Genome editing provides novel strategies for improving plant traits,but relies on current genetic transformation and plant regeneration procedures,which can be inefficient.We have engineered a barley stripe mosaic vir...Genome editing provides novel strategies for improving plant traits,but relies on current genetic transformation and plant regeneration procedures,which can be inefficient.We have engineered a barley stripe mosaic virus(BSMV)-based sgRNA delivery vector(BSMV-sg)that is effective in performing heritable genome editing in Cas9-transgenic wheat plants.Mutated progenies were present in the next generation at frequencies ranging from 12.9%to 100%in three different wheat varieties,and 53.8%to 100%of mutants were virus-free.We also achieved multiplex mutagenesis in progeny using a pool of BSMV-sg vectors harboring different sgRNAs.Furthermore,we devised a virus-induced transgene-free editing procedure(VITF-Edit)to generate Cas9-free wheat mutants by crossing BSMV-infected Cas9-transgenic wheat pollen with wild-type wheat.Our study provides a robust,convenient and tissue culture-free approach for genome editing in wheat through virus infection.展开更多
Facing the growth of energy demand and the worldwide interests in renewable energy sources,smart grid has been proposed in order to accommodate the needs of power grid development.In China,digital substations have bee...Facing the growth of energy demand and the worldwide interests in renewable energy sources,smart grid has been proposed in order to accommodate the needs of power grid development.In China,digital substations have been widely applied.Moreover,as the worldwide interest and development in smart grid have increased significantly,the digital information availability and communication capability of modern substation have been improved.Different with traditional substation protection configuration based on local information,Integrated Protection(IP)is used to denote the integration of several protective devices for multiple power equipment within the substation into one protective relay,obtaining all the real time information of the substation by communication network.The analysis of sharing information and cooperation among different protection functions helps to realize more reliable and sensitive fault detection.This paper describes several different integrated protection schemes and their respective advantages and disadvantages.The principles and functions applied in integrated protection systems are addressed to provide an overview of the current state of the technology.A new coordinated protection system based on inter-substation information is proposed and simulation study is discussed to verify the improved reliability and sensitivity.展开更多
In the present work,nanoporous carbon(NPC)was prepared from a metal-organic framework(zeolite imidazolate framework 8,ZIF-8).Different concentrations of graphene oxide(GO)were used to make NPC/reduced graphene oxide(N...In the present work,nanoporous carbon(NPC)was prepared from a metal-organic framework(zeolite imidazolate framework 8,ZIF-8).Different concentrations of graphene oxide(GO)were used to make NPC/reduced graphene oxide(NPC/rGO-x,x=0.5,1.0,1.5,and 2.0)composites,and thenγ-MnS/NPC/rGO-1 composite was synthesized via a simple hydrothermal technique.The electrochemical characteristics of porous carbon composites(NPC/rGO-x)andγ-MnS/NPC/rGO-1 electrodes were investigated by galvanostatic charge and discharge,cyclic voltammetry,and electrochemical impedance spectroscopy.NPC/rGO-1 showed the highest specific capacitance of 207 F/g at 0.5 A/g.Also,theγ-MnS/NPC/rGO-1 electrode demonstrates exceptional electrochemical performance with a high specific capacitance of 300 F/g at 0.5 A/g and impressive cyclic stability of 70%capacitance retention after 10,000 cycles at 1 A/g.As a result,this study demonstrates thatγ-MnS/NPC/rGO-1 electrode can be considered a promising candidate for high-performance supercapacitors.展开更多
Marine microorganisms have proven to be a rich source of natural products with unique structures and novel activities,due to their special living conditions.Macrolactins(MLNs),mostly produced by marine-derived microor...Marine microorganisms have proven to be a rich source of natural products with unique structures and novel activities,due to their special living conditions.Macrolactins(MLNs),mostly produced by marine-derived microorganisms,are a group of 24-membered lactone natural products,which exhibit potent antibacterial,antifungal,antiviral,anticancer,antiinfammatory,anti-angiogenic and other activities.Their extensive biological activities make them potential compounds for drug development.MLNs are biosynthesized via a type I polyketide synthase(PKS)pathway with diferent tailoring steps,such as epoxidation,glycosylation and acylation.These modifcation steps provide opportunities to diversify their structures by combinatorial biosynthesis strategies.This review mainly focuses on the newly discovered MLNs in the past fve years,including their biological activities and relevant biosynthetic studies.展开更多
基金Supported by Guangxi First-class Discipline Construction Project(2018xk0602019xk105)+2 种基金Open Project of Guangxi Key Laboratory of Zhuang and Yao Medicine(GXZYKF2019-2,GXZYKF2022-11)Research Project of Guangxi Key Laboratory of Pharmacodynamic Research of Traditional Chinese Medicine(19-050-39-A6)Program of Key Laboratory for Purification and Quality Analysis of TCM Extraction in Guangxi Universities(Gui Jiao Ke Yan[2014]No.6).
文摘[Objectives]To study the protective effect and mechanism of n-butanol extract of Diploclisia glaucescens(B1.)Diels on rats with adjuvant arthritis.[Methods]A rat adjuvant arthritis(AA)model with similarities to a clinical RA(rheumatoid arthritis)patient was used,and the model was made by injection of Complete Freund s adjuvant(CFA).Body mass and joint swelling degree were used as indicators,and the organ index was calculated and the synovial tissue of rats was examined under microscope to evaluate the protective effect of n-butanol extract on arthritis.The effects of n-butanol extract on TNF-α,IL-1βand PGE_(2)contents in rat serum were detected by ELISA kit.[Results]Arthritic rats experienced significant weight loss;the n-butanol extract reduced the joint swelling in rats.It exerted an effect on rat organs and reduced the contents of TNF-α,IL-1βand PGE_(2) in rat serum,and also reduced synovial inflammation in rats.[Conclusions]The n-butanol extract of D.glaucescens can protect rats with adjuvant arthritis by reducing the content of inflammatory factors.
基金supported by the Opening Project(SKLACPS-C-21)of the State Key Laboratory of Advanced Chemical Power Source,Guizhou Meiling Power Sources Co.,Ltd.the Program for Innovative and Entrepreneurial team in Zhuhai(ZH01110405160007PWC).
文摘Lithium metal anode is a promising electrode with high theoretical specific capacity and low electrode potential.However,its unstable interface and low Coulombic efficiency,resulting from the dendritic growth of lithium,limits its commercial application.PIM-1(PIM:polymer of intrinsic microporosity),which is a polymer with abundant micropores,exhibits high rigidity and flexibility with contorted spirocenters in the backbone,and is an ideal candidate for artificial solid electrolyte interphases(SEI).In this work,a PIM-1 membrane was synthesized and fabricated as a protective membrane on the surface of an electrode to facilitate the uniform flux of Li ions and act as a stable interface for the lithium plating/stripping process.Nodule-like lithium with rounded edges was observed under the PIM-1 membrane.The Li@PIM-1 electrode delivered a high average Coulombic efficiency(99.7%),excellent cyclability(80%capacity retention rate after 600 cycles at 1 C),and superior rate capability(125.3 m Ah g-1 at 10 C).Electrochemical impedance spectrum(EIS)showed that the PIM-1 membrane could lower the diffusion rate of Li+significantly and change the rate-determining step from charge transfer to Li+diffusion.Thus,the PIM-1 membrane is proven to act as an artificial SEI to facilitate uniform and stable deposition of lithium,in favor of obtaining a compact and dense Li-plating pattern.This work extends the application of PIMs in the field of lithium batteries and provides ideas for the construction of artificial SEI.
基金National Natural Science Foundation of China(81660701)Natural Science Foundation of Guangxi(2016GXNSFAA380148)+1 种基金Scientific Research Innovation Program of Guangxi University of Chinese Medicine(YJSZ201712)Program of Key Laboratory for Purification and Quality Analysis of TCM Extraction in Guangxi Universities(Gui Jiao Ke Yan[2014]No.6).
文摘[Objectives]To optimize the extraction process of polysaccharide in Embelia parviflora Wall.by response surface methodology,and to study the antioxidant activity in vitro of polysaccharide in E.parviflora,so as to provide a basis for the further development and utilization of E.parviflora.[Methods]The solid-to-liquid ratio,extraction temperature,extraction time and extraction times were used as single factors to investigate the effects.On this basis,the response surface methodology(RSM)was used to optimize the extraction process of polysaccharide in E.parviflora.DPPH and ABTS free radicals were used to investigate the antioxidant capacity of polysaccharide in E.parviflora.[Results]The optimal solid-to-liquid ratio for extraction of polysaccharide from E.parviflora was 32∶1(mL/g),extraction temperature was 77℃,and extraction time was 36 min.The IC50 values of DPPH and ABTS were 0.04 and 0.03 mg/mL,respectively.[Conclusions]The optimized extraction process of polysaccharide in E.parviflora is stable,the extraction rate is high,and has strong antioxidant activity.It is expected to provide a reference for the industrial extraction of polysaccharide from E.parviflora.
文摘Experiments were carried out to study the effects of nitrification inhibitors (NI) on the transformation of soil nitrogen (N) in purple soil and the effects on the N accumulation in different organs of citrus seedlings. In incubation and pot experiments, the rate of nitrification inhibitors 2-chloro-6-trichloro-methyl pyridine (Nitrapyrin), 3,4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD) was 2.4%, 1.0% and 5.0% of N rate, respectively. The trend of different nitrification inhibitors on ammonium nitrogen ( NH+4-N ), nitrate nitrogen ( NO-3-N ) content and pH was compared in incubation experiment;and the effect of different NI on the dry matter quality, N uptake of citrus seedling was studied in pot experiment. The results showed that NI could significantly inhibit soil nitrification in the early culture period (p DMPP > En (calculated as nitrogen application rate). Application of NI increased the height and dry matter accumulation, N accumulation of citrus seedling grown in pot experiment. Thus, application of NI would be helpful for improving N use efficiency in purple soil which is one of major soil types for citrus production in China.
基金Supported by Key R&D Project of Guangxi Science and Technology Department(GuiKeAB19110003).
文摘[Objectives]To establish the quality control method of Dujieqing pills.[Methods]Tangerine peel and Panax notoginseng in Dujieqing pills were qualitatively identified by thin layer chromatography(TLC).The content of hesperidin and ginsenoside Rb1 was determined by HPLC.The acetonitrile-aqueous solution was used as mobile phase for gradient elution,the detection wavelength was 203 nm,the flow rate was 1.0 mL/min,the column temperature was 25℃,and the injection volume was 10μL.[Results]Under TLC,tangerine peel and P.notoginseng had clear chromatographic spots,good separation effect,and strong specificity and negative samples showed no interference;there was a good linear relationship between hesperidin and ginsenoside Rb1 in the range of 0.838-8.38μg(R2=0.9994)and 0.44-4.4μg(R2=0.9994),respectively;the average recovery(n=9)was 98.90%(RSD=2.31%)and 98.31%(RSD=2.56%),respectively.[Conclusions]The established quality control method is simple,reproducible,accurate and reliable,and can be used for the quality control of Dujieqing pills.
基金Supported by the Self-funded Research Project of Administration of Traditional Chinese Medicine of Guangxi Zhuang Autonomous Region(GXZYZ20210078)Key Research and Development Project of Guangxi Science and Technology Department(Guike AB19110003).
文摘[Objectives] To establish a method for the determination of active components in toad skin. [Methods] HPLC method was used to determine the content of five active components (bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin) in toad skin. [Results] Chromatographic conditions are as follows: Agilent ZORBAX SB-C 18 chromatographic column was used;acetonitrile (A)-0.3% glacial acetic acid (B) gradient elution (0-15 min, 28%A-54%A;15-35 min, 54%A-54%A) was conducted;the flow rate was 0.6 mL/min;the detection wavelength was 296 nm;the column temperature was 30 ℃;the sample size was 10 μL. Under the above conditions, the determination method of the five components can be established at one time. [Conclusions] The method was stable and reliable, and can provide experimental basis for the development and utilization of active ingredients in toad skin.
文摘Lakes are important ecological water sources in the Bashang Plateau. Its expansion or shrinkage directly affects the ecological security of the plateau and its surrounding areas. In this study, Landsat images from 1984 to 2015 were selected to monitor the area of lakes in the Bashang Plateau and to analyze the spatiotemporal evolution and driving forces of lakes in the Bashang Plateau. The results showed that there were 47 lakes in the Bashang Plateau in 2015, with a total area of 37.63 km2, mainly distributed in the central and western regions of the region. From 1984 to 2015, the lakes in Bashang Plateau showed a shrinking trend. At the same time, there are obvious stage differences in lake changes. During 1984-1996, the number of lakes increased by 99 and the total area increased by 124.43 km2. From 1996 to 2015, the number of lakes decreased by 142, and the total area decreased by 183.96 km2. Before 1996, climate change was the dominant factor. However, the shrinkage of lakes after 1996 is the result of climate change and human activities. Among them, the large-scale planting of water consuming crops such as vegetables is the main human activity mode leading to lake shrinkage. This study will help to understand the expansion and contraction factors of the Bashang Plateau lakes in Hebei province and provide a reference for the future protection and management of the lakes.
基金The Hainan Provincial Natural Science Foundation of China under contract No.322CXTD531the National Key Research and Development Program of China under contract Nos 2018YFC0310005,2016YFC0302504.
文摘Some deep-sea microbes may incorporate inorganic carbon to reduce CO_(2) emission to upper layer and atmosphere.How the microbial inhabitants can be affected under addition of bicarbonate has not been studied using in situ fixed and lysed samples.In this study,we cultivated 40 L natural bottom water at~1000 m depth with a final concentration of 0.1 mmol/L bicarbonate for 40 min and applied multiple in situ nucleic acids collection(MISNAC)apparatus for nucleic acids extraction from the cultivation.Our classification result of the cultivation sample showed a distinct microbial community structure,compared with the samples obtained by Niskin bottle and six working units of MISNAC.Except for notable enrichment of Alteromonas,we detected prevalence of Asprobacter,Ilumatobacter and Saccharimonadales in the cultivation.Deep-sea lineages of Euryarchaeota,SAR406,SAR202 and SAR324 were almost completely absent from the cultivation and Niskin samples.This study revealed the dominant microbes affected by bicarbonate addition and Niskin sampling,which suggested rapid responses of deep-sea microbes to the environmental changes.
文摘The molar heat capacities(C_p) of guaiacol(CAS 90-50-1) and acetyl guaiacol ester(AGE, CAS 613-70-7) were determinated from 290 K to 350 K by differential scanning calorimetry(DSC), and expressed as a function of temperature. Two kinds of group contribution models were used to estimate the molar heat capacities of both guaiacol and AGE, the average relative deviation is less than 10%. The standard molar enthalpies of combustion of guaiacol and AGE were- 3590.0 k J·mol^(-1)and- 4522.1 k J·mol^(-1) by a precise thermal isolation Oxygen Bomb Calorimeter. The standard molar enthalpies of formation of guaiacol and AGE in a liquid state at298.15 K were calculated to be- 307.95 k J·mol^(-1) and- 448.72 k J·mol^(-1), respectively, based on the standard molar enthalpies of combustion. The thermodynamic properties are useful for exploiting the new synthesis method, engineering design and industry production of AGE using guaiacol as a raw material.
基金supported by the Natural Science Foundation of China(Grants 71431002 and 71872033)the Major Programs of the National Social Science Foundation of China(Grants 22&ZD159).
文摘E-commerce is a typical form of retail digitalization that introduces online uncertainty and product returns.To decrease the negative influence of online uncertainty,the largest Chinese e-commerce company,the Alibaba Group,invited an insurance company to develop return-freight insurance(RFI),a new kind of insurance,to compensate for consumers'losses in the event of online product returns.Complimentary RFl can increase consumer confidence in the retailer and attract more demand.Retailers who offer complimentary RFI demonstrate to consumers that their products and services are too good to incur excessive product returns.However,some low-quality online retailers can mimic competitors'behavior by offering complimentary RFI to consumers.This study aims to introduce an innovative online return policy based on RFI and to explore whether lowquality online retailers would use complimentary RFI as their return strategy to mislead consumers.Using signaling theory,we built a conceptual economic model that includes three exogenous pricing variables:RF,insurance premium,and compensation.These variables play different roles in the model because consumers cannot observe the insurance premium,but the compensation can be.The main finding of this study is that innovative complimentary RFI could be abused by low-type retailers when the premium and compensation are appropriate.Interestingly,compensation plays different roles for retailers with different product values:low-type retailers use complimentary RFI as a noise tool.When the product works for the consumer and the insurance profit is not too high,the compensation for the low-quality product should be larger than that for the highquality product,which is different from conventional wisdom.Although high-type online retailers may use complimentary RFl as a product quality signal,there is still a significant risk that nefarious elements will use it to create product quality noise.
基金funded by China National Natural Youth Science Foundation(81802078)Zhejiang Province Public Welfare Research Foundation(GF20H200021)Zhejiang Provincial Department of Medicine and Health Foundation(2019RC315).
文摘The long non-coding RNA,Negative Regulator of Antiviral Response(NRAV)has been identified as a participant in both respiratory virus replication and immune checkpoints,however,its involvement in pan-cancer immune regulation and prognosis,particularly those of hepatocellular carcinoma(HCC),remains unclear.To address this knowledge gap,we analyzed expression profiles obtained from The Cancer Genome Atlas(TCGA)database,comparing normal and malignant tumor tissues.We found that NRAV expression is significantly upregulated in tumor tissues compared to adjacent nontumor tissues.Kaplan-Meier(K-M)analysis revealed the prognostic power of NRAV,wherein overexpression was significantly linked to reduced overall survival in a diverse range of tumor patients.Furthermore,noteworthy associations were observed between NRAV,immune checkpoints,immune cell infiltration,genes related to autophagy,epithelial-mesenchymal transition(EMT),pyroptosis,tumor mutational burden(TMB),and microsatellite instability(MSI)across different cancer types,including HCC.Moreover,NRAV upregulation expression was associated with multiple pathological stages by clinical observations.Furthermore,our investigation revealed a substantial elevation in the expression of NRAV in both HCC tumor tissues and cells compared to normal tissues and cells.The inhibition of NRAV resulted in the inhibition of cell proliferation,migration,and invasion in HCC cells,while also influencing the expression of CD274(PD-L1)and CD44,along with various biomarkers associated with EMT,autophagy,and pyroptosis.The aforementioned results propose NRAV as a promising prognostic biomarker for HCC.
基金This work was supported by the Strategic Priority Research Program of the CAS(Precision Seed Design and Breeding,XDA24020310 and XDA24020100)the National Natural Science Foundation of China(31830106 and 31872637)+2 种基金The Project for Extramural Scientists of the State Key Laboratory of Agro-Biotechnology(2021SKLAB6-7)Chinese Universities Scientific Fund(2021TC112)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2020000003).
文摘Genome editing provides novel strategies for improving plant traits,but relies on current genetic transformation and plant regeneration procedures,which can be inefficient.We have engineered a barley stripe mosaic virus(BSMV)-based sgRNA delivery vector(BSMV-sg)that is effective in performing heritable genome editing in Cas9-transgenic wheat plants.Mutated progenies were present in the next generation at frequencies ranging from 12.9%to 100%in three different wheat varieties,and 53.8%to 100%of mutants were virus-free.We also achieved multiplex mutagenesis in progeny using a pool of BSMV-sg vectors harboring different sgRNAs.Furthermore,we devised a virus-induced transgene-free editing procedure(VITF-Edit)to generate Cas9-free wheat mutants by crossing BSMV-infected Cas9-transgenic wheat pollen with wild-type wheat.Our study provides a robust,convenient and tissue culture-free approach for genome editing in wheat through virus infection.
基金supported by the National Natural Science Foundation of China under Grant 51277009,and the Application Technology Research and Engineering Demonstration Program of National Energy Administration under Grant NY20150302.
文摘Facing the growth of energy demand and the worldwide interests in renewable energy sources,smart grid has been proposed in order to accommodate the needs of power grid development.In China,digital substations have been widely applied.Moreover,as the worldwide interest and development in smart grid have increased significantly,the digital information availability and communication capability of modern substation have been improved.Different with traditional substation protection configuration based on local information,Integrated Protection(IP)is used to denote the integration of several protective devices for multiple power equipment within the substation into one protective relay,obtaining all the real time information of the substation by communication network.The analysis of sharing information and cooperation among different protection functions helps to realize more reliable and sensitive fault detection.This paper describes several different integrated protection schemes and their respective advantages and disadvantages.The principles and functions applied in integrated protection systems are addressed to provide an overview of the current state of the technology.A new coordinated protection system based on inter-substation information is proposed and simulation study is discussed to verify the improved reliability and sensitivity.
基金This work was supported by the Fund of State Key Laboratory of Multiphase Complex System(No.MPCS-2021-A-12),Institute of Process Engineering,Chinese Academy of Sciences.
文摘In the present work,nanoporous carbon(NPC)was prepared from a metal-organic framework(zeolite imidazolate framework 8,ZIF-8).Different concentrations of graphene oxide(GO)were used to make NPC/reduced graphene oxide(NPC/rGO-x,x=0.5,1.0,1.5,and 2.0)composites,and thenγ-MnS/NPC/rGO-1 composite was synthesized via a simple hydrothermal technique.The electrochemical characteristics of porous carbon composites(NPC/rGO-x)andγ-MnS/NPC/rGO-1 electrodes were investigated by galvanostatic charge and discharge,cyclic voltammetry,and electrochemical impedance spectroscopy.NPC/rGO-1 showed the highest specific capacitance of 207 F/g at 0.5 A/g.Also,theγ-MnS/NPC/rGO-1 electrode demonstrates exceptional electrochemical performance with a high specific capacitance of 300 F/g at 0.5 A/g and impressive cyclic stability of 70%capacitance retention after 10,000 cycles at 1 A/g.As a result,this study demonstrates thatγ-MnS/NPC/rGO-1 electrode can be considered a promising candidate for high-performance supercapacitors.
基金This work was fnancially supported by the grants from the National Key R&D Program of China(2019YFC0312501)the National Natural Science Foundation of China(U1706206,31570032).
文摘Marine microorganisms have proven to be a rich source of natural products with unique structures and novel activities,due to their special living conditions.Macrolactins(MLNs),mostly produced by marine-derived microorganisms,are a group of 24-membered lactone natural products,which exhibit potent antibacterial,antifungal,antiviral,anticancer,antiinfammatory,anti-angiogenic and other activities.Their extensive biological activities make them potential compounds for drug development.MLNs are biosynthesized via a type I polyketide synthase(PKS)pathway with diferent tailoring steps,such as epoxidation,glycosylation and acylation.These modifcation steps provide opportunities to diversify their structures by combinatorial biosynthesis strategies.This review mainly focuses on the newly discovered MLNs in the past fve years,including their biological activities and relevant biosynthetic studies.
