The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue ...The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame protection.Our study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and safety.This research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body connectors.Our goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector components.Three typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and methods.Firstly,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation patterns.Then,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic strain.Lastly,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint components.Subsequently,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending simulations.Each joint component showcased a remarkable 30%–40%mass reduction while boosting energy absorption.Our design optimization method exhibits high efficiency and costeffectiveness.Leveraging contemporary automation technology,the design optimization platform developed in this study is poised to facilitate intelligent optimization of lightweight metal components in future applications.展开更多
以枸杞为原料制备枸杞汁、枸杞醋,并添加白砂糖及菊花提取液制备枸杞果醋饮料,通过单因素试验及正交试验优化枸杞果醋饮料配方,并对其感官、理化及微生物指标进行分析。结果表明,枸杞果醋饮料的最佳配方为:枸杞醋8%,枸杞汁15%,白砂糖6%...以枸杞为原料制备枸杞汁、枸杞醋,并添加白砂糖及菊花提取液制备枸杞果醋饮料,通过单因素试验及正交试验优化枸杞果醋饮料配方,并对其感官、理化及微生物指标进行分析。结果表明,枸杞果醋饮料的最佳配方为:枸杞醋8%,枸杞汁15%,白砂糖6%,菊花提取液15%。在最优配方条件下,枸杞果醋饮料感官评分为95.47分,枸杞果醋饮料口感柔和、酸甜爽口。总酸、不挥发酸及氨基酸态氮含量分别为0.66 g/100 m L、0.36 g/100 m L、0.07 g/100 m L,总糖、蛋白质、脂肪含量分别为9.62 g/100 m L、0.48 g/100 m L、0.06 g/100 m L,其理化及微生物指标均符合国家农业部标准NY/T 2987—2016《绿色食品果醋饮料》要求。展开更多
AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was estab...AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was established. mRNA and protein expression levels of CDX2, survivin, cyclin D1, and c-Myc were detected by western blotting and semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The influence of downregulation of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2 small interfering RNA (siRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. RESULTS: CDX2 siRNA led to downregulation of endogenous CDX2 mRNA (0.31 ± 0.05 vs 1.10 ± 0.51, 0.31 ± 0.05 vs 1.05 ± 0.21, P = 0.003) and protein (0.12 ± 0.08 vs 0.51 ± 0.07, 0.12 ± 0.08 vs 0.55 ± 0.16, P = 2.57 × 10 -4) expression. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin (0.12 ± 0.05 vs 0.33 ± 0.08, 0.12 ± 0.05 vs 0.39 ± 0.15, P = 0.001), doxorubicin (0.52 ± 0.13 vs 4.11 ± 1.25, 0.52 ± 0.13 vs 4.05 ± 1.44, P = 2.81 × 10-4), and 5-fluorouracil (0.82 ± 0.13 vs 2.81 ± 0.51, 0.82 ± 0.13 vs 3.28 ± 1.03, P = 1.71 × 10-4). Flow cytometry confirmed that the percentage of apoptotic cells increased after CDX2 downregulation (32.15% ± 2.15% vs 17.63% ± 3.16%, 32.15% ± 2.15% vs 19.3% ± 2.25%, P = 1.73 × 10-6). This notion was further supported by the observation that downregulation of CDX2 blocked entry into the S-phase of the cell cycle (31.53% ± 3.78% vs 65.05% ± 7.25%, 31.53% ± 3.78% vs 62.27% ± 5.02%, P = 7.55 × 10-7). Furthermore, downregulation of CDX2 significantly increased intracellular accumulation of doxorubicin (0.21 ± 0.06 vs 0.41 ± 0.11, 0.21 ± 0.06 vs 0.40 ± 0.08, P = 0.003). In molecular studies, semiquantitative RT-PCR and western blotting revealed that CDX2 downregulation could inhibit expression of c-Myc, survivin and cyclin D1. CONCLUSION: CDX2 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that CDX2 may represent a novel target for gastric cancer therapy.展开更多
AIM: To evaluate the influence of E2F-1 on the growth of human gastric cancer(GC) cells in vivo and the mechanism involved. METHODS: E2F-1 recombinant lentiviral vectors were injected into xenograft tumors of MGC-803 ...AIM: To evaluate the influence of E2F-1 on the growth of human gastric cancer(GC) cells in vivo and the mechanism involved. METHODS: E2F-1 recombinant lentiviral vectors were injected into xenograft tumors of MGC-803 cells in nude mice, and then tumor growth was investigated. Overexpression of transcription factor E2F-1 was assessed by reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting analysis. Apoptosis rates were determined using a terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling(TUNEL) assay. Expression levels of certain cell cycle regulators and apoptosis-related proteins, such as Bax, survivin, Bcl-2, cyclin D1, S-phase kinaseassociated protein 2, and c-Myc were examined by Western blotting and RT-PCR. RESULTS: Xenograft tumors of MGC-803 cells in nude mice injected with E2F-1 recombinant lentiviral vectors stably overexpressed the E2F-1 gene as measured by semi-quantitative RT-PCR(relative m RNA expression: 0.10 ± 0.02 vs 0.05 ± 0.02 for control vector and 0.06 ± 0.03 for no infection; both P < 0.01) and Western blotting(relative protein expression: 1.90 ± 0.05 vs 1.10 ± 0.03 in control vector infected and 1.11 ± 0.02 for no infection; both P < 0.01). The growth-curve of tumor volumes revealed that infection with E2F-1 recombinant lentiviral vectors significantly inhibited the growth of human GC xenografts(2.81 ± 1.02 vs 6.18 ± 1.15 in control vector infected and 5.87 ± 1.23 with no infection; both P < 0.05) at 15 d after treatment. TUNEL analysis demonstrated that E2F-1 overexpression promoted tumor cell apoptosis(18.6% ± 2.3% vs 6.7% ± 1.2% in control vector infected 6.3% ± 1.2% for no infection; both P < 0.05). Furthermore, lentiviral vector-mediated E2F-1 overexpression increased theexpression of Bax and suppressed survivin, Bcl-2, cyclin D1, Skp2, and c-Myc expression in tumor tissue.CONCLUSION: E2F-1 inhibits growth of GC cells via regulating multiple signaling pathways, and may play an important role in targeted therapy for GC.展开更多
AIM:To investigate the effects of small interference RNA(siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo.METHODS:The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed a...AIM:To investigate the effects of small interference RNA(siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo.METHODS:The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed and transfected into gastric cancer MGC-803 cells in vitro.The stable transfectants were selected.The effects of Cdx2 siRNA on growth,proliferation,cell cycle,apoptosis,migration and invasiveness of human gastric cancer MGC-803 cells were evaluated and the expression of phosphatase and tensin homolog(PTEN),caspase-9 and caspase-3 was observed in vitro by reverse transcription polymerase chain reaction(RT-PCR) and Western blotting analysis.We also investigated the effect of Cdx2 siRNA on growth of MGC-803 cells in nude mice in vivo.RESULTS:Cdx2 siRNA led to inhibition of endogenous Cdx2 mRNA and protein expression as determined by RT-PCR and Western blotting analysis.Cdx2 siRNA significantly inhibited cell growth and proliferation,blocked entry into the S-phase of the cell cycle,induced cell apoptosis,and reduced the motility and invasion of MGC-803 cells.Cdx2 siRNA also increased PTEN expression,and activated caspase-9 and caspase-3 in MGC-803 cells in vitro.In addition,siRNA targeting of Cdx2 inhibited the growth of MGC-803 cells and promoted tumor cell apoptosis in vivo in nude mice tumor models.CONCLUSION:Cdx2 was involved in regulating progression of human gastric cancer cells MGC-803.Manipulation of Cdx2 expression may be a potential therapeutic strategy for gastric cancer.展开更多
Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human g...Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human gastrointestinal cancers. In addition, gastric epithelial cell mutations in CDX2 result in tumor promotion, which is characterized by cellular drug resistance and a high proclivity for developing cancer. A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance. CDX2 appears to forward control regenerating IV and the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance.展开更多
In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and th...In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and the manipulation of EM radiation on a single programmable metasurface(PM).The PM consists of massive subwavelength-scale digital coding elements.A set of digital states of all elements forms simultaneous digital information roles for modulation and the wave-control sequence code of the PM.By designing digital coding sequences in the spatial and temporal domains,the digital information and farfield patterns of the PM can be programmed simultaneously and instantly in desired ways.For the experimental demonstration of the mechanism,we present a programmable wireless communication system.The same system can realize transmissions of digital information in single-channel modes with beamsteerable capability and multichannel modes with multiple independent information.The measured results show the excellent performance of the programmable system.This work provides excellent prospects for applications in fifth-or sixth-generation wireless communications and modern intelligent platforms for unmanned aircrafts and vehicles.展开更多
The a-L-rhamnopyranosyl phosphomonoesters conjugated with L-amino acid methyl esters were stereoselectively synthesized in a convenient route by utilizing H-phosphonate intermediate.
12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route simple operation and high y...12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route simple operation and high yield.展开更多
10-vinyl-8,11,13-podocatriene 8, which is a modal of Carnosic acid type diterpenes, has been synthesized by an expeditious convergent synthetic approach.
Dove tree(Davidia involucrata),a tertiary vestige species,is well-adapted to cool conditions.Dormancy in D.involucrata seed lasts for an extremely long period of time,typically between 3 and 4 years,and this character...Dove tree(Davidia involucrata),a tertiary vestige species,is well-adapted to cool conditions.Dormancy in D.involucrata seed lasts for an extremely long period of time,typically between 3 and 4 years,and this characteristic makes the species an excellent model for studying the mechanisms of seed dormancy.The molecular mechanisms governing germination control in D.involucrata are still unknown.Seed stratification have been reported to enhance germination in recalcitrant seeds.We performed a widely targeted metabolome profiling to identify metabolites and associated pathways in D.involucrata seeds from six different moist sand stratification durations(0-30 months) using the ultra-high-performance liquid chromatography-Q Exactive Orbitrap-Mass spectrometry.There was an increasing germination rate with prolonged stratification durations(12-30 months).Furthermore,we detected 10,008 metabolites in the stratified seeds.We also detected 48 differentially accumulated metabolites(DAMs) between all stratification periods in the seeds,with 10 highly conserved metabolites.Most of the differentially accumulated metabolites between unstratified and stratified seeds were enriched in purine metabolism,pyrimidine metabolism,flavone and flavonol biosynthesis,phenylpropanoid biosynthesis,and arginine biosynthesis pathways.Key phytohormones,abscisic acid,indole-3 acetic acid,and sinapic acid were differentially accumulated in the seeds and are predicted to regulate dormancy in D.involucrata.We have provided extensive metabolic information useful for future works on dove tree germination study.展开更多
Background:Karst areas in southwestern China exhibit ecological degradation in the form of rocky desertification.Local governments launched large-scale afforestation and other ecological restoration programs to curb t...Background:Karst areas in southwestern China exhibit ecological degradation in the form of rocky desertification.Local governments launched large-scale afforestation and other ecological restoration programs to curb this trend.Soil thickness is a key limiting factor for vegetation restoration in Karst areas,but the relationship between ecological restoration and soil thickness remains unclear.Further,afforestation consumes large amounts of water,which impacts water supply in karst areas.In this study,we used GIS and statistical analyses to determine rocky desertification sensitivity and its driving factors in karst areas of Chongqing municipality over the past decade.Results:Soil thickness is one of the key factors that restrict ecological restoration of rocky desertification.From 2000 to 2010,rocky desertification sensitivity in karst areas was on the rise along with an increase in afforestation.Areas of high sensitivity were mainly distributed in Pengshui County,Wulong District,and Youyang County;Shizhu County had the lowest overall incidence of desertification.Spatial distribution of rocky desertification was significantly affected by rainfall and soil thickness.Regression analysis showed that the main factors controlling changes in rocky desertification in natural forest over time were precipitation which explained 23.73%of total variance,and soil thickness which explained 23.42%of total variance.Soil thickness and soil water content had a higher correlation coefficient(at 0.516)in natural forests than in planted forests.Conclusion:This study showed that increases in soil thickness in a karst area had a significant positive impact on the fragile ecological environment.This indicates that ecosystem restoration in karst areas will benefit from addressing soil thickness.展开更多
Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and...Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and improve propulsion performance.Therefore,in order to improve the characteristics of detonation flow field,the three-dimensional numerical simulation of annular chamber and hollow chamber is carried out with premixed hydrogen/air as fuel in this paper,and then tries to combine the two chambers to weaken the oscillation characteristics of detonation flow field through the interaction of detonation flow field,which is a new method to regulate the detonation flow field.The results show that there are four states of velocity vectors at the outlet of annular chamber and hollow chamber,which makes RDE be affected by rolling moment and results in the loss of axial kinetic energy.In the external flow field of combined chamber,the phenomenon of cyclic reflection of expansion wave and compression wave on the free boundary is observed,which results in Mach disk structure.Moreover,the pressure monitoring points are set at the external flow field.The pressure signal shows that the high-frequency pressure oscillation at the external flow field of the combined chamber has been greatly weakened.Compared to the annular chamber,the relative standard deviation(RSD) has been reduced from 14.6% to5.6%.The results thus demonstrate that this method is feasible to adjust the pressure oscillation characteristics of the detonation flow field,and is of great significance to promote the potential of RDE and nozzle design.展开更多
In this study,different molar of methylolureas(MMU)were used to improve the properties and drying speed of the raw lacquer(RL).The drying time,gloss,pencil hardness and impact resistance of the lacquer film were teste...In this study,different molar of methylolureas(MMU)were used to improve the properties and drying speed of the raw lacquer(RL).The drying time,gloss,pencil hardness and impact resistance of the lacquer film were tested.The thermal behaviors and chemical structures of the lacquer membrane were also discussed by thermal gravimetric analysis(TGA),fourier infrared spectrometer(FT-IR)and nuclear magnetic resonance(NMR)analysis,respectively.The results demonstrated that lower molar ratio MMU can significantly improve the properties of lacquer.The TGA analysis showed that the modified lacquer had high thermal stability than that of the control.The FT-IR and 13C NMR analysis revealed that the structures of the modified lacquer were significantly improved by cross-linking with the hydroxymethyl groups and methylene methyl ethers of MMU.In addition,through scanning electron microscopy(SEM)characterization,it was found that the introduction of MMU can effectively improve the surface smoothness of the lacquer film.展开更多
Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single el...Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single electron oxidation reactions for synthesizing structurally diverse functionalized indoles and indolines. Electrocatalysis is considered as a synthetically attractive and environmentally friendly alternative for driving the single electron oxidation of indoles. Remarkable achievements in electrocatalytic indolederived radical cation-mediated indole functionalization have been realized so far. This review comprehensively summarizes the recent progresses in the applications of electrocatalytic indole radical cations,including C(sp~2)–H functionalization, dearomative 2,3-difunctionalization, and ring-opening reaction, emphasizing the vital single electron oxidation steps of indoles, the substrates scope and limitations, and the reaction mechanisms.展开更多
To solve the problems of excessive soil lumps,broken branches and seedlings in pods and difficulty in removing impurities in the harvested pods of peanuts in the hilly areas of southern China,which is due to the high ...To solve the problems of excessive soil lumps,broken branches and seedlings in pods and difficulty in removing impurities in the harvested pods of peanuts in the hilly areas of southern China,which is due to the high soil viscosity and easy hardening,and to improve the soil removal effect of the peanut half-feed pod picker in hilly areas of China,this article designed a half-feed peanut-cleaning picker suitable for southern clay hilly areas and provided a detailed introduction to the overall structure,working principle,and adjustment methods of various operating parameters.Through field measurement experiments,the influencing factors and laws of soil removal performance indicators,such as the comprehensive soil removal rate and POD drop rate,were studied.The results showed that the comprehensive soil removal rate gradually increased with increasing soil patting frequency,soil patting amplitude,and picking roller speed,first increased and then decreased with increasing picking roller gap and gradually decreased with increasing soil patting plate gap and clamping conveyor chain speed.The comprehensive soil removal rate of the soil patting plate using the opposite patting method was greater than that of the swinging patting method.The soil removal pod drop rate increased gradually with increasing soil patting frequency and amplitude and decreased with increasing soil patting plate gap and clamping conveyor chain speed.The soil removal pod drop rate of the soil patting plate using swing patting was lower than that using the opposite patting method.The speed and gap of the picking roller had no effect on the soil removal pod drop rate.The frequency,amplitude,form,and gap of the soil patting plate had extremely significant impacts on the rate of decrease in the number of soil removal pod drop rate.The clamping conveyor chain speed had a significant impact,while the speed and gap of the picking roller had no significant impact.The influence of all factors on the comprehensive soil removal rate was extremely significant.This study provides a theoretical basis and technical reference for parameter optimization research on peanut-cleaning picking machines in the clay hilly areas of southern China.展开更多
Background:Tall wheatgrass is a perennial salt-tolerant bunchgrass,which is a promising candidate for establishing a“Coastal Grass Belt”in China,particularly in the coastal saline–alkaline soils surrounding the Boh...Background:Tall wheatgrass is a perennial salt-tolerant bunchgrass,which is a promising candidate for establishing a“Coastal Grass Belt”in China,particularly in the coastal saline–alkaline soils surrounding the Bohai Sea.Methods:Seven harvesting treatments were performed to explore the optimal harvesting time and frequency for tall wheatgrass in coastal area.The dry matter yield(DMY)and forage nutritional values were investigated for each cut.The correlation between harvesting time and frequency thereof among the investigated traits was also determined.Results:The results showed that the two-cut on June 18 and October 29 produced the highest DMY.Another two-cut on May 26 and October 29 produced a relatively high crude protein(CP)yield.The DMY,contents of neutral detergent fiber(NDF),acid detergent fiber(ADF),and crude cellulose(CC)as well as CP yield were positively correlated to plant height,while the CP content and the relative feed value(RFV)were negatively correlated to plant height.The accumulating growing degree days,accumulated precipitation,and sunshine duration were positively correlated with plant height,DMY,contents of NDF,ADF,and CC as well as CP yield,but negatively correlated with CP content and RFV for the first cut.Conclusions:The two-cut treatment at the end of May and October may be suitable for tall wheatgrass in the“Coastal Grass Belt”targeted area.展开更多
基金the National Natural Science Foundation of China(Grant Number 52075553)the Postgraduate Research and Innovation Project of Central South University(School-Enterprise Association)(Grant Number 2021XQLH014).
文摘The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame protection.Our study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and safety.This research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body connectors.Our goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector components.Three typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and methods.Firstly,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation patterns.Then,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic strain.Lastly,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint components.Subsequently,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending simulations.Each joint component showcased a remarkable 30%–40%mass reduction while boosting energy absorption.Our design optimization method exhibits high efficiency and costeffectiveness.Leveraging contemporary automation technology,the design optimization platform developed in this study is poised to facilitate intelligent optimization of lightweight metal components in future applications.
文摘以枸杞为原料制备枸杞汁、枸杞醋,并添加白砂糖及菊花提取液制备枸杞果醋饮料,通过单因素试验及正交试验优化枸杞果醋饮料配方,并对其感官、理化及微生物指标进行分析。结果表明,枸杞果醋饮料的最佳配方为:枸杞醋8%,枸杞汁15%,白砂糖6%,菊花提取液15%。在最优配方条件下,枸杞果醋饮料感官评分为95.47分,枸杞果醋饮料口感柔和、酸甜爽口。总酸、不挥发酸及氨基酸态氮含量分别为0.66 g/100 m L、0.36 g/100 m L、0.07 g/100 m L,总糖、蛋白质、脂肪含量分别为9.62 g/100 m L、0.48 g/100 m L、0.06 g/100 m L,其理化及微生物指标均符合国家农业部标准NY/T 2987—2016《绿色食品果醋饮料》要求。
基金Supported by Grants from the Natural Science Foundation of China, No. 81060201Natural Science Foundation of Guangxi,No. 2011GXNSFA018273 and No. 2013GXNSFAA019163the Key Health Science Foundation of Guangxi, No. 1298003-2-6
文摘AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was established. mRNA and protein expression levels of CDX2, survivin, cyclin D1, and c-Myc were detected by western blotting and semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The influence of downregulation of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2 small interfering RNA (siRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. RESULTS: CDX2 siRNA led to downregulation of endogenous CDX2 mRNA (0.31 ± 0.05 vs 1.10 ± 0.51, 0.31 ± 0.05 vs 1.05 ± 0.21, P = 0.003) and protein (0.12 ± 0.08 vs 0.51 ± 0.07, 0.12 ± 0.08 vs 0.55 ± 0.16, P = 2.57 × 10 -4) expression. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin (0.12 ± 0.05 vs 0.33 ± 0.08, 0.12 ± 0.05 vs 0.39 ± 0.15, P = 0.001), doxorubicin (0.52 ± 0.13 vs 4.11 ± 1.25, 0.52 ± 0.13 vs 4.05 ± 1.44, P = 2.81 × 10-4), and 5-fluorouracil (0.82 ± 0.13 vs 2.81 ± 0.51, 0.82 ± 0.13 vs 3.28 ± 1.03, P = 1.71 × 10-4). Flow cytometry confirmed that the percentage of apoptotic cells increased after CDX2 downregulation (32.15% ± 2.15% vs 17.63% ± 3.16%, 32.15% ± 2.15% vs 19.3% ± 2.25%, P = 1.73 × 10-6). This notion was further supported by the observation that downregulation of CDX2 blocked entry into the S-phase of the cell cycle (31.53% ± 3.78% vs 65.05% ± 7.25%, 31.53% ± 3.78% vs 62.27% ± 5.02%, P = 7.55 × 10-7). Furthermore, downregulation of CDX2 significantly increased intracellular accumulation of doxorubicin (0.21 ± 0.06 vs 0.41 ± 0.11, 0.21 ± 0.06 vs 0.40 ± 0.08, P = 0.003). In molecular studies, semiquantitative RT-PCR and western blotting revealed that CDX2 downregulation could inhibit expression of c-Myc, survivin and cyclin D1. CONCLUSION: CDX2 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that CDX2 may represent a novel target for gastric cancer therapy.
基金Supported by National Natural Science Foundation of China,No.30860273 and No.81060201Natural Science Foundation of Guangxi,No.2011GXNSFA018273 and No.2013GX NSFAA019163the Key Health Science Project of Guangxi,No.Key1298003-2-6
文摘AIM: To evaluate the influence of E2F-1 on the growth of human gastric cancer(GC) cells in vivo and the mechanism involved. METHODS: E2F-1 recombinant lentiviral vectors were injected into xenograft tumors of MGC-803 cells in nude mice, and then tumor growth was investigated. Overexpression of transcription factor E2F-1 was assessed by reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting analysis. Apoptosis rates were determined using a terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling(TUNEL) assay. Expression levels of certain cell cycle regulators and apoptosis-related proteins, such as Bax, survivin, Bcl-2, cyclin D1, S-phase kinaseassociated protein 2, and c-Myc were examined by Western blotting and RT-PCR. RESULTS: Xenograft tumors of MGC-803 cells in nude mice injected with E2F-1 recombinant lentiviral vectors stably overexpressed the E2F-1 gene as measured by semi-quantitative RT-PCR(relative m RNA expression: 0.10 ± 0.02 vs 0.05 ± 0.02 for control vector and 0.06 ± 0.03 for no infection; both P < 0.01) and Western blotting(relative protein expression: 1.90 ± 0.05 vs 1.10 ± 0.03 in control vector infected and 1.11 ± 0.02 for no infection; both P < 0.01). The growth-curve of tumor volumes revealed that infection with E2F-1 recombinant lentiviral vectors significantly inhibited the growth of human GC xenografts(2.81 ± 1.02 vs 6.18 ± 1.15 in control vector infected and 5.87 ± 1.23 with no infection; both P < 0.05) at 15 d after treatment. TUNEL analysis demonstrated that E2F-1 overexpression promoted tumor cell apoptosis(18.6% ± 2.3% vs 6.7% ± 1.2% in control vector infected 6.3% ± 1.2% for no infection; both P < 0.05). Furthermore, lentiviral vector-mediated E2F-1 overexpression increased theexpression of Bax and suppressed survivin, Bcl-2, cyclin D1, Skp2, and c-Myc expression in tumor tissue.CONCLUSION: E2F-1 inhibits growth of GC cells via regulating multiple signaling pathways, and may play an important role in targeted therapy for GC.
基金Supported by Grants from the Natural Science Foundation of China,No.81060201 and No.81060277the Higher School Specialized Research Foundation for the Doctoral Program of China,No.20114503110002+1 种基金the Postdoctoral Science Foundation of China,No.201003342the Natural Science Foundation of Guangxi,No.2011GXNSFA018273
文摘AIM:To investigate the effects of small interference RNA(siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo.METHODS:The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed and transfected into gastric cancer MGC-803 cells in vitro.The stable transfectants were selected.The effects of Cdx2 siRNA on growth,proliferation,cell cycle,apoptosis,migration and invasiveness of human gastric cancer MGC-803 cells were evaluated and the expression of phosphatase and tensin homolog(PTEN),caspase-9 and caspase-3 was observed in vitro by reverse transcription polymerase chain reaction(RT-PCR) and Western blotting analysis.We also investigated the effect of Cdx2 siRNA on growth of MGC-803 cells in nude mice in vivo.RESULTS:Cdx2 siRNA led to inhibition of endogenous Cdx2 mRNA and protein expression as determined by RT-PCR and Western blotting analysis.Cdx2 siRNA significantly inhibited cell growth and proliferation,blocked entry into the S-phase of the cell cycle,induced cell apoptosis,and reduced the motility and invasion of MGC-803 cells.Cdx2 siRNA also increased PTEN expression,and activated caspase-9 and caspase-3 in MGC-803 cells in vitro.In addition,siRNA targeting of Cdx2 inhibited the growth of MGC-803 cells and promoted tumor cell apoptosis in vivo in nude mice tumor models.CONCLUSION:Cdx2 was involved in regulating progression of human gastric cancer cells MGC-803.Manipulation of Cdx2 expression may be a potential therapeutic strategy for gastric cancer.
基金Supported by The National Natural Science Foundation of China,No.81060201Natural Science Foundation of Guangxi Zhuang Autonomous Region of China,No.2011GXNS-FA018273 and No.2013GXNSFAA019163the Key Health Science Fund of Guangxi Zhuang Autonomous Region of China,No.1298003-2-6
文摘Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human gastrointestinal cancers. In addition, gastric epithelial cell mutations in CDX2 result in tumor promotion, which is characterized by cellular drug resistance and a high proclivity for developing cancer. A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance. CDX2 appears to forward control regenerating IV and the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance.
基金supported by the Fund for International Cooperation and Exchange of National Natural Science Foundation of China(61761136007)the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)+3 种基金the National Natural Science Foundation of China(6217010363,61631007,61571117,61501112,61501117,61871109,61522106,61731010,61735010,61722106,61701107,and 61701108)the Natural Science Foundation of Jiangsu Province(BK20211161)the 111 Project(111-2-05)ZhiShan Young Scholar Program of Southeast University.
文摘In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and the manipulation of EM radiation on a single programmable metasurface(PM).The PM consists of massive subwavelength-scale digital coding elements.A set of digital states of all elements forms simultaneous digital information roles for modulation and the wave-control sequence code of the PM.By designing digital coding sequences in the spatial and temporal domains,the digital information and farfield patterns of the PM can be programmed simultaneously and instantly in desired ways.For the experimental demonstration of the mechanism,we present a programmable wireless communication system.The same system can realize transmissions of digital information in single-channel modes with beamsteerable capability and multichannel modes with multiple independent information.The measured results show the excellent performance of the programmable system.This work provides excellent prospects for applications in fifth-or sixth-generation wireless communications and modern intelligent platforms for unmanned aircrafts and vehicles.
基金The authors would like to thank the financial supports from the NNSF of China(No.201 72033),the Ministry of Science and Technology,the Ministry of Education and Tsinghua University.
文摘The a-L-rhamnopyranosyl phosphomonoesters conjugated with L-amino acid methyl esters were stereoselectively synthesized in a convenient route by utilizing H-phosphonate intermediate.
基金the National Natural Science Foundation of China.
文摘12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route simple operation and high yield.
基金the National Natural Science Foundation of China.
文摘10-vinyl-8,11,13-podocatriene 8, which is a modal of Carnosic acid type diterpenes, has been synthesized by an expeditious convergent synthetic approach.
基金funded by the National Natural Sciences Foundation of China (31460203,31860073)Research Center for Germplasm Engineering of Characteristic Plant Resources in Enshi Prefecture (2019-2021)Hubei Key Laboratory of Biological Resources Protection and Utilization (PT012204)
文摘Dove tree(Davidia involucrata),a tertiary vestige species,is well-adapted to cool conditions.Dormancy in D.involucrata seed lasts for an extremely long period of time,typically between 3 and 4 years,and this characteristic makes the species an excellent model for studying the mechanisms of seed dormancy.The molecular mechanisms governing germination control in D.involucrata are still unknown.Seed stratification have been reported to enhance germination in recalcitrant seeds.We performed a widely targeted metabolome profiling to identify metabolites and associated pathways in D.involucrata seeds from six different moist sand stratification durations(0-30 months) using the ultra-high-performance liquid chromatography-Q Exactive Orbitrap-Mass spectrometry.There was an increasing germination rate with prolonged stratification durations(12-30 months).Furthermore,we detected 10,008 metabolites in the stratified seeds.We also detected 48 differentially accumulated metabolites(DAMs) between all stratification periods in the seeds,with 10 highly conserved metabolites.Most of the differentially accumulated metabolites between unstratified and stratified seeds were enriched in purine metabolism,pyrimidine metabolism,flavone and flavonol biosynthesis,phenylpropanoid biosynthesis,and arginine biosynthesis pathways.Key phytohormones,abscisic acid,indole-3 acetic acid,and sinapic acid were differentially accumulated in the seeds and are predicted to regulate dormancy in D.involucrata.We have provided extensive metabolic information useful for future works on dove tree germination study.
基金the National Key R&D Program of China(2016YFC0502304).
文摘Background:Karst areas in southwestern China exhibit ecological degradation in the form of rocky desertification.Local governments launched large-scale afforestation and other ecological restoration programs to curb this trend.Soil thickness is a key limiting factor for vegetation restoration in Karst areas,but the relationship between ecological restoration and soil thickness remains unclear.Further,afforestation consumes large amounts of water,which impacts water supply in karst areas.In this study,we used GIS and statistical analyses to determine rocky desertification sensitivity and its driving factors in karst areas of Chongqing municipality over the past decade.Results:Soil thickness is one of the key factors that restrict ecological restoration of rocky desertification.From 2000 to 2010,rocky desertification sensitivity in karst areas was on the rise along with an increase in afforestation.Areas of high sensitivity were mainly distributed in Pengshui County,Wulong District,and Youyang County;Shizhu County had the lowest overall incidence of desertification.Spatial distribution of rocky desertification was significantly affected by rainfall and soil thickness.Regression analysis showed that the main factors controlling changes in rocky desertification in natural forest over time were precipitation which explained 23.73%of total variance,and soil thickness which explained 23.42%of total variance.Soil thickness and soil water content had a higher correlation coefficient(at 0.516)in natural forests than in planted forests.Conclusion:This study showed that increases in soil thickness in a karst area had a significant positive impact on the fragile ecological environment.This indicates that ecosystem restoration in karst areas will benefit from addressing soil thickness.
文摘Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and improve propulsion performance.Therefore,in order to improve the characteristics of detonation flow field,the three-dimensional numerical simulation of annular chamber and hollow chamber is carried out with premixed hydrogen/air as fuel in this paper,and then tries to combine the two chambers to weaken the oscillation characteristics of detonation flow field through the interaction of detonation flow field,which is a new method to regulate the detonation flow field.The results show that there are four states of velocity vectors at the outlet of annular chamber and hollow chamber,which makes RDE be affected by rolling moment and results in the loss of axial kinetic energy.In the external flow field of combined chamber,the phenomenon of cyclic reflection of expansion wave and compression wave on the free boundary is observed,which results in Mach disk structure.Moreover,the pressure monitoring points are set at the external flow field.The pressure signal shows that the high-frequency pressure oscillation at the external flow field of the combined chamber has been greatly weakened.Compared to the annular chamber,the relative standard deviation(RSD) has been reduced from 14.6% to5.6%.The results thus demonstrate that this method is feasible to adjust the pressure oscillation characteristics of the detonation flow field,and is of great significance to promote the potential of RDE and nozzle design.
基金support by Key Research and Development Project of Sichuan Science and Technology Plan Projects(Grant No.2020YFS0357)Ministry of Education Humanities and Social Sciences Research Project of China(Grant No.19YJC760009)+1 种基金Research Program of Science and Technology Agency of Sichuan of China(Project No.2012129068)Research Interest in Training Program of Sichuan Agricultural University(Project No.2021182)。
文摘In this study,different molar of methylolureas(MMU)were used to improve the properties and drying speed of the raw lacquer(RL).The drying time,gloss,pencil hardness and impact resistance of the lacquer film were tested.The thermal behaviors and chemical structures of the lacquer membrane were also discussed by thermal gravimetric analysis(TGA),fourier infrared spectrometer(FT-IR)and nuclear magnetic resonance(NMR)analysis,respectively.The results demonstrated that lower molar ratio MMU can significantly improve the properties of lacquer.The TGA analysis showed that the modified lacquer had high thermal stability than that of the control.The FT-IR and 13C NMR analysis revealed that the structures of the modified lacquer were significantly improved by cross-linking with the hydroxymethyl groups and methylene methyl ethers of MMU.In addition,through scanning electron microscopy(SEM)characterization,it was found that the introduction of MMU can effectively improve the surface smoothness of the lacquer film.
基金the National Natural Science Foundation of China (No.22261019)the Jiangxi Provincial Natural Science Foundation (No.20224BAB213004)+1 种基金the Education Department of Jiangxi Province(Nos.GJJ211134 and GJJ211137)the PhD start-up fund of Jiangxi Science&Technology Normal University (No.2021BSQD32) for financial support。
文摘Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single electron oxidation reactions for synthesizing structurally diverse functionalized indoles and indolines. Electrocatalysis is considered as a synthetically attractive and environmentally friendly alternative for driving the single electron oxidation of indoles. Remarkable achievements in electrocatalytic indolederived radical cation-mediated indole functionalization have been realized so far. This review comprehensively summarizes the recent progresses in the applications of electrocatalytic indole radical cations,including C(sp~2)–H functionalization, dearomative 2,3-difunctionalization, and ring-opening reaction, emphasizing the vital single electron oxidation steps of indoles, the substrates scope and limitations, and the reaction mechanisms.
基金supported by the Jiangsu Agricultural Science and Technology Innovation Fund(Grant No.CX(23)3028)National Natural Science Foundation of China(Grant No.52105263)+2 种基金Key Laboratory of Modern Agricultural Intelligent Equipment in South China,Ministry of Agriculture and Rural Affairs,China(Grant No.HNZJ202201)Key Laboratory of Agricultural Equipment for Hilly and Mountainous Areas in Southeastern China(Co-construction by Ministry and Province),Ministry of Agriculture and Rural Affairs(Grant No.QSKF202304)Key Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang Province(Grant No.2022ZJZD2201).
文摘To solve the problems of excessive soil lumps,broken branches and seedlings in pods and difficulty in removing impurities in the harvested pods of peanuts in the hilly areas of southern China,which is due to the high soil viscosity and easy hardening,and to improve the soil removal effect of the peanut half-feed pod picker in hilly areas of China,this article designed a half-feed peanut-cleaning picker suitable for southern clay hilly areas and provided a detailed introduction to the overall structure,working principle,and adjustment methods of various operating parameters.Through field measurement experiments,the influencing factors and laws of soil removal performance indicators,such as the comprehensive soil removal rate and POD drop rate,were studied.The results showed that the comprehensive soil removal rate gradually increased with increasing soil patting frequency,soil patting amplitude,and picking roller speed,first increased and then decreased with increasing picking roller gap and gradually decreased with increasing soil patting plate gap and clamping conveyor chain speed.The comprehensive soil removal rate of the soil patting plate using the opposite patting method was greater than that of the swinging patting method.The soil removal pod drop rate increased gradually with increasing soil patting frequency and amplitude and decreased with increasing soil patting plate gap and clamping conveyor chain speed.The soil removal pod drop rate of the soil patting plate using swing patting was lower than that using the opposite patting method.The speed and gap of the picking roller had no effect on the soil removal pod drop rate.The frequency,amplitude,form,and gap of the soil patting plate had extremely significant impacts on the rate of decrease in the number of soil removal pod drop rate.The clamping conveyor chain speed had a significant impact,while the speed and gap of the picking roller had no significant impact.The influence of all factors on the comprehensive soil removal rate was extremely significant.This study provides a theoretical basis and technical reference for parameter optimization research on peanut-cleaning picking machines in the clay hilly areas of southern China.
基金Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDA26040105。
文摘Background:Tall wheatgrass is a perennial salt-tolerant bunchgrass,which is a promising candidate for establishing a“Coastal Grass Belt”in China,particularly in the coastal saline–alkaline soils surrounding the Bohai Sea.Methods:Seven harvesting treatments were performed to explore the optimal harvesting time and frequency for tall wheatgrass in coastal area.The dry matter yield(DMY)and forage nutritional values were investigated for each cut.The correlation between harvesting time and frequency thereof among the investigated traits was also determined.Results:The results showed that the two-cut on June 18 and October 29 produced the highest DMY.Another two-cut on May 26 and October 29 produced a relatively high crude protein(CP)yield.The DMY,contents of neutral detergent fiber(NDF),acid detergent fiber(ADF),and crude cellulose(CC)as well as CP yield were positively correlated to plant height,while the CP content and the relative feed value(RFV)were negatively correlated to plant height.The accumulating growing degree days,accumulated precipitation,and sunshine duration were positively correlated with plant height,DMY,contents of NDF,ADF,and CC as well as CP yield,but negatively correlated with CP content and RFV for the first cut.Conclusions:The two-cut treatment at the end of May and October may be suitable for tall wheatgrass in the“Coastal Grass Belt”targeted area.