Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrha...Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrhagic area.However,the regulato ry mechanism of histone deacetylases in central post-stroke pain remains unclea r.Here,we show that iron overload leads to an increase in histone deacetylase 2expression in damaged ventral posterolateral nucleus neurons.Inhibiting this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium(Kv)channel subunit gene in a rat model of central post-stroke pain,thereby increasing Kcna2expression and relieving central pain.However,in the absence of nerve injury,increasing histone deacetylase 2 expression decreased Kcna2expression,decreased Kv current,increased the excitability of neurons in the ventral posterolateral nucleus area,and led to neuropathic pain symptoms.Moreover,treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage,reversed histone deacetylase 2 upregulation and Kv1.2 downregulation,and alleviated mechanical hypersensitivity in central post-stroke pain rats.These results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation,mediated by iron overload,are important factors in central post-stroke pain pathogenesis and co uld se rve as new to rgets for central poststroke pain treatment.展开更多
The thermodynamic properties of boron nitride under extreme pressures and temperatures are of great interest and importance for materials science and inertial confinement fusion physics,but they are poorly understood ...The thermodynamic properties of boron nitride under extreme pressures and temperatures are of great interest and importance for materials science and inertial confinement fusion physics,but they are poorly understood owing to the challenges of performing experiments and realizing ab initio calculations.Here,we report the first shock Hugoniot data on hexagonal boron nitride at pressures of 5–16 Mbar,using hohlraum-driven shock waves at the SGIII-p laser facility in China.Our density functional theory molecular dynamics calculations closely match experimental data,validating the equations of state for modeling the shock response of boron nitride and filling a crucial gap in the knowledge of boron nitride properties in the region of multi-Mbar pressures and eV temperatures.The results presented here provide fundamental insights into boron nitride under the extreme conditions relevant to inertial confinement fusion,hydrogen–boron fusion,and high-energy-density physics.展开更多
In light of the rapid expansion of China s economy,there has been a notable shift in the consumption patterns of urban and rural residents.This is evident in the increased consumption of agricultural products,with fru...In light of the rapid expansion of China s economy,there has been a notable shift in the consumption patterns of urban and rural residents.This is evident in the increased consumption of agricultural products,with fruit consumption representing a particularly pronounced trend.The 2023 Beijing Consumption Statistics indicate that demand for fruit is increasing,accompanied by heightened competition for quality and brands.The paper is based on research that examines the current situation of fruit consumption among urban and rural residents in Beijing.The results indicate that when urban and rural residents in Beijing purchase fruits,price is the most significant factor influencing fruit consumption.Taste,appearance,and variety are also considered to be important influencing factors,while the influence of factors such as fruit type,consumption pattern,and fruit brand is relatively minor.展开更多
The development of surface modification technology for temperature sensitive fibers has been a huge challenge.In this work,a novel technique based on cold plasma treatment was developed for the preparation of anti-bac...The development of surface modification technology for temperature sensitive fibers has been a huge challenge.In this work,a novel technique based on cold plasma treatment was developed for the preparation of anti-bacterial polypropylene(PP)fibers.The results showed that plasma treatment introduced a rough surface and polar groups,which acted as the anchor point and initiators for diallyldimethyl ammonium chloride(DADMAC)graft-polymerization.The fabricated PP membranes presented a high bacterial sterilization rate,as well as excellent adhesion force and washing durability.After ultrasonic treatment for 30 min,the physical coating sample had lost anti-bacterial effect,while the plasma grafted sample still showed a sterilization rate of 91.67%.This work provided a clean and novel DADMAC grafting method and it is also applicable for anti-bacterial material fabrication.展开更多
With the rise of various new reading media and the rapid development of the digitization of paper resources,the traditional function positioning of university libraries based on information query is facing unprecedent...With the rise of various new reading media and the rapid development of the digitization of paper resources,the traditional function positioning of university libraries based on information query is facing unprecedented challenges.How to deal with the change of social information?The library should be demand-oriented,re-examine its own value and find a new starting point.With the help of the concept of customer delivered value and based on 4P theory,this paper constructs the value chain of university library from the dimensions of product,image,personnel and service,and forms a multi-dimensional development positioning system.展开更多
Metaverse is a virtual world,but it is possible and even becomes a trend that metaverse interacts with the real world along with the sci-tech and social development.Smart library is a main direction of modern library ...Metaverse is a virtual world,but it is possible and even becomes a trend that metaverse interacts with the real world along with the sci-tech and social development.Smart library is a main direction of modern library development,from informatization to digitization and then intelligent-based,modernization of library has been improved qualitatively.Emergence of metaverse brings a brand-new horizon to the generation and application of agricultural information,this paper made primary explorations the requirements and action mechanism of agricultural information on the construction of smart library within the external constraint of metaverse.展开更多
A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the...A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the structure-directing agent for the MWW layered structure;and dicyclohexylamine(DCHA),in the role of an in-situ delaminating agent.By varying the amount of DCHA,partially and fully delaminated MWW zeolites having two MWW structure layers and one single layer,respectively,were obtained.These were denoted as SCM-1(Sinopec Composite Material)and SCM-6,respectively.The delaminated materials possess ultra-large external surface areas,and the transmission electron microscopy images illustrated their layered nature.In the reaction of liquid phase benzene alkylation with ethylene,SCM-1,the double-layered MWW zeolite,exhibited far superior catalytic performance compared to zeolite MCM-22.展开更多
Rotor-assembled strand works as a typical tube insert to achieve heat transfer augmentation and scale inhibition in a heat exchanger.In this work, the PIV experiment regarding the flow fields in a circular tube insert...Rotor-assembled strand works as a typical tube insert to achieve heat transfer augmentation and scale inhibition in a heat exchanger.In this work, the PIV experiment regarding the flow fields in a circular tube inserted with rotor-assembled strand was conducted and the flow characteristics on transverse section and longitudinal section were analyzed.The results showed that swirling flow was produced in the tube inserted with rotors and it was particularly strong within the swing diameter of the rotor on the section that contains the rotor;the average turbulence intensity and the radial velocity were improved notably; the velocity vectors on the longitudinal section remained along the direction of a straight line; both the swirling flow and average turbulence intensity were higher for the rotor with three blades than for the rotor with two blades except that the radial velocity was approximate, but they were all reduced by enlarging the lead of the rotor.Characterization of the flow patterns in a circular tube contributes to understanding the heat transfer efficiency and scale inhibition performance of the rotor-assembled strand and provides guidance for its application.展开更多
NASICON-type Na_(3)V_(2)(PO_(4))_(3) is a promising electrode material for developing advanced sodium-ion batteries.Preparing Na_(3)V_(2)(PO_(4))_(3) with good performance by a cost-effective and large-scale method is...NASICON-type Na_(3)V_(2)(PO_(4))_(3) is a promising electrode material for developing advanced sodium-ion batteries.Preparing Na_(3)V_(2)(PO_(4))_(3) with good performance by a cost-effective and large-scale method is significant for industrial applications.In this work,a porous Na_(3)V_(2)(PO_(4))_(3)/C cathode material with excellent electrochemical performance is successfully prepared by an agar-gel combined with freeze-drying method.The Na_(3)V_(2)(PO_(4))_(3)/C cathode displayed specific capacities of 113.4 mAh·g^(-1),107.0 mAh·g^(-1) and 87.1 mAh·g^(-1) at 0.1 C,1 C and 10 C,respectively.For the first time,the 500-mAh soft-packed symmetrical sodium-ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C electrodes are successfully fabricated.The 500-mAh symmetrical batteries exhibit outstanding low temperature performance with a capacity retention of 83%at 0℃ owing to the rapid sodium ion migration ability and structural stability of Na_(3)V_(2)(PO_(4))_(3)/C.Moreover,the thermal runaway features are revealed by accelerating rate calorimetry(ARC)test for the first time.Thermal stability and safety of the symmetrical batteries are demonstrated to be better than lithium-ion batteries and some reported sodium-ion batteries.Our work makes it clear that the soft-packed symmetrical sodium ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C have a prospect of practical application in high safety requirement fields.展开更多
Although some genes that cause Kallmann syndrome (KS) have been identified by traditional linkage analysis and candidate gene techniques, the syndrome's molecular etiology in the majority of patients remains poorly...Although some genes that cause Kallmann syndrome (KS) have been identified by traditional linkage analysis and candidate gene techniques, the syndrome's molecular etiology in the majority of patients remains poorly understood. In this paper, we present the clinical assessments of a consanguineous Hart Chinese family with three KS descendants. To understand the molecular etiology of KS from a genome-wide perspective, we investigated the genome-wide profile of structural variation in this family using the Affymetrix Genome-Wide Human SNP Array 6.0 platform. The results revealed that the three affected individuals had common copy number variants (microdeletions) on chromosomes lp21.1, 2q32.2, 8q21.13, 14q21.2 and Xp22.31. Moreover, the copy number variants on Xp22.31 were located in the intron of KAL 1, which causes X-linked KS. Two PCR assays were performed on these regions to validate the results obtained using the chips. In addition, genomic microdeletions in this region were verified in one of 29 Han Chinese sporadic KS cases and one of four other family cases, but not in 26 Han Chinese sporadic normosmic idiopathic hypogonadotropic hypogonadism cases and 100 unrelated Han Chinese normal controls. Our results provide a novel insight into the relative contributions of certain copy number variants to KS's molecular etiology and generate a list of interesting candidate regions for further studies.展开更多
A series of ZSM-5@MCM-41 core-shell composite materials prepared via a multi-cycle-sol-gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene,in which both ethylbenzene and para-diet...A series of ZSM-5@MCM-41 core-shell composite materials prepared via a multi-cycle-sol-gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene,in which both ethylbenzene and para-diethylbenzene(p-DEB)are aimed as the target products.With multi-cycle-sol-gel coating,the external acid sites on the samples are gradually passivated by the inert MCM-41 shell.As a result,the shape selectivity to p-DEB is greatly enhanced.Nevertheless,the coating of mesoporous MCM-41 shell on ZSM-5 accelerates deactivation of the catalyst only due to the dilution effect of ZSM-5 content in the catalyst at the same space velocity,which is a reason that core-shell ZSM-5@MCM-41 will potentially be a practical catalyst in shape selective alkylation of benzene.In order to enhance the yield of p-DEB on ZSM-5@MCM-41,the reaction conditions at the fixed bed reactor including temperature,the molar rate of benzene to ethylene and GHSV,are also optimized.展开更多
OBJECTIVE: To summarize Cochrane reviews of acupuncture for neurological disorders, and characteristics of included reviews and studies. DATA SOURCES: A computer-based online search of the Cochrane Library (Issue 7...OBJECTIVE: To summarize Cochrane reviews of acupuncture for neurological disorders, and characteristics of included reviews and studies. DATA SOURCES: A computer-based online search of the Cochrane Library (Issue 7 of 12, July 2010) was performed with the key word "acupuncture" and systematic evaluations for acupuncture for neurological disorders were screened. STUDY SELECTION: Systematic reviews on acupuncture in the treatment of neurological disorders were included, and the characteristics of these reviews were analyzed based on methods recommended by the Cochrane collaboration. MAIN OUTCOME MEASURES: Basic characteristics, methodological quality, main reasons for excluding trials, results and conclusions of Cochrane reviews were assessed. RESULTS: A total of 18 Cochrane systematic reviews were included, including 13 completed reviews and five research protocols. The 13 completed reviews involved 111 randomized controlled trials, including 43 trials (38.7%) conducted in China, 47 trials (42.3%) using sham-acupuncture or placebo as control, 15 trials (13.5%) with relatively high quality, 91 trials (81.9%) reporting data on follow-up. Primary outcomes used in the Cochrane reviews were reported by 65 trials (58.6%), and adverse events were reported in 11 trials (9.9%). Two hundred and eighty three trials were excluded. Two reviews on headache suggested that acupuncture is a valuable non-drug treatment for patients with chronic or recurrent headache, and has better curative effects on migraine compared with preventative drug treatment. CONCLUSION: Of the Cochrane reviews on acupuncture in the treatment of neurological disorders, two reviews evaluating the efficacy of acupuncture in treating headaches drew positive conculsions, while other reviews did not obtain positive conclusions due to a small sample size or low methodological quality. The methodological quality of acupuncture trials needs further improvement.展开更多
In this contribution,we report the cooperative structure-directing effect of choline hydroxide and aluminosilicate*BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolites for the first time.*BEA zeolites,a...In this contribution,we report the cooperative structure-directing effect of choline hydroxide and aluminosilicate*BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolites for the first time.*BEA zeolites,at variance with any other aluminosilicate zeolites,can serve as heterogeneous seeds for the growth of IWR zeolites and play a cooperative structure-directing role.The crystallization process was investigated using multiple techniques to characterize a series of solid products obtained with various crystallization times.The experiments clearly showed the dissolution of the*BEA zeolite and of an intermediate CDO-type structure.A plausible mechanism for the novel cooperative synthesis has been proposed.The crystallization of the IWR zeolite involves several steps,among which the crucial one is believed to be the reassembly of the building units produced from the decomposition of*BEA zeolite seeds,induced by choline molecules.Having similar structure and common building units(four-,five-,and six-membered rings)with the IWR zeolite,the*BEA zeolite is capable of promoting the reassembly of the building units and can thus play a cooperative structure-directing role.By highlighting the cooperative structure-directing effect of organic molecules and heterogeneous seeds,this study opens up new perspectives for the synthesis of target zeolites that are difficult to prepare by traditional methods.This new synthetic route is also expected to shed light on the discovery of novel zeolites.展开更多
Taking the rural residents in Yanqing District of Beijing as the research object,through field investigations and interviews,it is found that the main characteristics,income and expenditure level,preference and cognit...Taking the rural residents in Yanqing District of Beijing as the research object,through field investigations and interviews,it is found that the main characteristics,income and expenditure level,preference and cognitive level of rural residents are the factors that affect the dairy consumption behavior of rural residents.Using the bivariate regression model for empirical analysis,it is concluded that rural residents'occupation,monthly average income,purchase expenditure and attitude towards dairy safety have a significant impact on rural residents'dairy consumption behavior,and then relevant constructive suggestions are put forward to guide rural residents'balanced consumption.展开更多
[Objectives]This paper aimed to prepare derivatives of protopanaxadiol from Panax notoginseng(Burk.)FH Chen with acid anhydrides and study their anti-tumor activity.[Methods]The 3-hydroxyl group of protopanaxadiol was...[Objectives]This paper aimed to prepare derivatives of protopanaxadiol from Panax notoginseng(Burk.)FH Chen with acid anhydrides and study their anti-tumor activity.[Methods]The 3-hydroxyl group of protopanaxadiol was subjected to structural modification and reacted with acid anhydrides to prepare derivatives,in order to improve the anti-tumor activity of protopanaxadiol.None of the five compounds designed and synthesized had been reported in the literature,and they were novel compounds.The anti-tumor activity of the derivatives was studies using MTS method.Taking cisplatin and paclitaxel as positive control drugs,the bioactivity of the compounds 1-5 on anti-tumor cell lines(HL-60 cells,SMMC-7721 cells,A-549 cells,MCF-7 cells and SW480 cells)in vitro was screened.[Results]The compound 5 showed inhibitory effect on HL-60 cells,SMMC-7721 cells and A-549 cells.[Conclusions]The acid anhydride esterification method is simple to operate and easy to control.This study has reference value for the structural modification and anti-tumor activity research of protopanaxadiol from P.notoginseng(Burk.)FH Chen.展开更多
The agricultural leading enterprises and farmers have formed a mutual linkage,mutual restraint,and interdependent benefit linkage mechanism.This paper mainly analyzes the existing problems in the benefit linkage betwe...The agricultural leading enterprises and farmers have formed a mutual linkage,mutual restraint,and interdependent benefit linkage mechanism.This paper mainly analyzes the existing problems in the benefit linkage between the agricultural leading enterprises and farmers,and draws on the successful domestic benefit linkage model,and comes up with policy recommendations to provide an effective approach for agricultural leading enterprises to promote development of farmers.展开更多
Objective:To determine whether NF-κB is constitutively activated in human bladder cancer cell and,if so,to deter-mine the invasiveness inhibition of bladder cancer cells by nuclear factor-κB decoy—circular dumbbell...Objective:To determine whether NF-κB is constitutively activated in human bladder cancer cell and,if so,to deter-mine the invasiveness inhibition of bladder cancer cells by nuclear factor-κB decoy—circular dumbbell oligodeoxynucleotides(CD-ODN).Methods:NF-κBp65 activation was determined by immunohistochemical analysis of formalin-fixed,paraffin-embed-ded specimens from 38 cases of bladder transitional cell carcinoma patients.We quantified nuclear staining of RelA as a marker of NF-κBp65 activation.CD-ODN were transfected into human bladder cancer cell line BIU87 by lipofectamine.Luciferase reporter were applied to detecting NF-κB DNA binding activity.The expression levels of uPA were detected by RT-PCR and the cells’ invasion ability by transwell cell culture chamber.Results:P65 excessive activation existed in tumor cell(P<0.01),the activation degree correlated significantly with the expression of uPA(r=0.89,P<0.01),as well as related to tumor invasion-related clinicopathological features such as lymphatic metastasis(P<0.01)and pathological ranking(P<0.05);After transfection with CD-ODN,the activation of NF-κB in BIU87 cell line was suppressed remarkably,the expression level of uPA was decreased and the cells’ invasiveness was weakened as well.Conclusion:Excessively activated NF-κB is related to tumor progression pos-sibly due to its transcriptional regulation of invasion-related factors such as uPA.CD-ODN can efficiently suppress DNA binding activity of NF-κB to reduce the invasive potency of tumor.展开更多
As shown in the agricultural development experience of various countries in the world,the agricultural operating entity has become an effective means to increase the agricultural production efficiency and establish a ...As shown in the agricultural development experience of various countries in the world,the agricultural operating entity has become an effective means to increase the agricultural production efficiency and establish a scientific management model.Promoting the continuous improvement of the modern agricultural management system is not only an important means for solving the three rural issues in China,but also a key measure to enhance China's agricultural competitiveness.This paper introduced the basic situation of agricultural operating entities in Japan and Germany,summarized their advanced experience,and finally came up with feasible recommendations for enhancing the competitive advantages of agricultural operating entities in China.展开更多
基金supported by the National Natural Science Foundation of China,Nos.U2004106 (to WY),81971061 (to JC)the Key Scientific Research Project of Colleges and Universities in Henan Province,No.21A320039 (to WY)。
文摘Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrhagic area.However,the regulato ry mechanism of histone deacetylases in central post-stroke pain remains unclea r.Here,we show that iron overload leads to an increase in histone deacetylase 2expression in damaged ventral posterolateral nucleus neurons.Inhibiting this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium(Kv)channel subunit gene in a rat model of central post-stroke pain,thereby increasing Kcna2expression and relieving central pain.However,in the absence of nerve injury,increasing histone deacetylase 2 expression decreased Kcna2expression,decreased Kv current,increased the excitability of neurons in the ventral posterolateral nucleus area,and led to neuropathic pain symptoms.Moreover,treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage,reversed histone deacetylase 2 upregulation and Kv1.2 downregulation,and alleviated mechanical hypersensitivity in central post-stroke pain rats.These results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation,mediated by iron overload,are important factors in central post-stroke pain pathogenesis and co uld se rve as new to rgets for central poststroke pain treatment.
文摘The thermodynamic properties of boron nitride under extreme pressures and temperatures are of great interest and importance for materials science and inertial confinement fusion physics,but they are poorly understood owing to the challenges of performing experiments and realizing ab initio calculations.Here,we report the first shock Hugoniot data on hexagonal boron nitride at pressures of 5–16 Mbar,using hohlraum-driven shock waves at the SGIII-p laser facility in China.Our density functional theory molecular dynamics calculations closely match experimental data,validating the equations of state for modeling the shock response of boron nitride and filling a crucial gap in the knowledge of boron nitride properties in the region of multi-Mbar pressures and eV temperatures.The results presented here provide fundamental insights into boron nitride under the extreme conditions relevant to inertial confinement fusion,hydrogen–boron fusion,and high-energy-density physics.
文摘In light of the rapid expansion of China s economy,there has been a notable shift in the consumption patterns of urban and rural residents.This is evident in the increased consumption of agricultural products,with fruit consumption representing a particularly pronounced trend.The 2023 Beijing Consumption Statistics indicate that demand for fruit is increasing,accompanied by heightened competition for quality and brands.The paper is based on research that examines the current situation of fruit consumption among urban and rural residents in Beijing.The results indicate that when urban and rural residents in Beijing purchase fruits,price is the most significant factor influencing fruit consumption.Taste,appearance,and variety are also considered to be important influencing factors,while the influence of factors such as fruit type,consumption pattern,and fruit brand is relatively minor.
基金supported by National Natural Science Foundation of China(Nos.51877205 and 52011530191)Fundamental Research Funds for the Central Universities(No.buctrc201906)Beijing Nova Program(No.2022015)。
文摘The development of surface modification technology for temperature sensitive fibers has been a huge challenge.In this work,a novel technique based on cold plasma treatment was developed for the preparation of anti-bacterial polypropylene(PP)fibers.The results showed that plasma treatment introduced a rough surface and polar groups,which acted as the anchor point and initiators for diallyldimethyl ammonium chloride(DADMAC)graft-polymerization.The fabricated PP membranes presented a high bacterial sterilization rate,as well as excellent adhesion force and washing durability.After ultrasonic treatment for 30 min,the physical coating sample had lost anti-bacterial effect,while the plasma grafted sample still showed a sterilization rate of 91.67%.This work provided a clean and novel DADMAC grafting method and it is also applicable for anti-bacterial material fabrication.
基金Supported by Key Research Project of Education and Teaching Reform in Beijing University of Agriculture from 2021 to 2022.
文摘With the rise of various new reading media and the rapid development of the digitization of paper resources,the traditional function positioning of university libraries based on information query is facing unprecedented challenges.How to deal with the change of social information?The library should be demand-oriented,re-examine its own value and find a new starting point.With the help of the concept of customer delivered value and based on 4P theory,this paper constructs the value chain of university library from the dimensions of product,image,personnel and service,and forms a multi-dimensional development positioning system.
基金Sponsored by 2021-2022 Key Education and Teaching Reform Project of Beijing University of Agriculture:Cultivation of College Students Humanity Quality Based on the Smart Library Construction.
文摘Metaverse is a virtual world,but it is possible and even becomes a trend that metaverse interacts with the real world along with the sci-tech and social development.Smart library is a main direction of modern library development,from informatization to digitization and then intelligent-based,modernization of library has been improved qualitatively.Emergence of metaverse brings a brand-new horizon to the generation and application of agricultural information,this paper made primary explorations the requirements and action mechanism of agricultural information on the construction of smart library within the external constraint of metaverse.
文摘A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the structure-directing agent for the MWW layered structure;and dicyclohexylamine(DCHA),in the role of an in-situ delaminating agent.By varying the amount of DCHA,partially and fully delaminated MWW zeolites having two MWW structure layers and one single layer,respectively,were obtained.These were denoted as SCM-1(Sinopec Composite Material)and SCM-6,respectively.The delaminated materials possess ultra-large external surface areas,and the transmission electron microscopy images illustrated their layered nature.In the reaction of liquid phase benzene alkylation with ethylene,SCM-1,the double-layered MWW zeolite,exhibited far superior catalytic performance compared to zeolite MCM-22.
基金Supported by the National Natural Science Foundation of China(51576012)
文摘Rotor-assembled strand works as a typical tube insert to achieve heat transfer augmentation and scale inhibition in a heat exchanger.In this work, the PIV experiment regarding the flow fields in a circular tube inserted with rotor-assembled strand was conducted and the flow characteristics on transverse section and longitudinal section were analyzed.The results showed that swirling flow was produced in the tube inserted with rotors and it was particularly strong within the swing diameter of the rotor on the section that contains the rotor;the average turbulence intensity and the radial velocity were improved notably; the velocity vectors on the longitudinal section remained along the direction of a straight line; both the swirling flow and average turbulence intensity were higher for the rotor with three blades than for the rotor with two blades except that the radial velocity was approximate, but they were all reduced by enlarging the lead of the rotor.Characterization of the flow patterns in a circular tube contributes to understanding the heat transfer efficiency and scale inhibition performance of the rotor-assembled strand and provides guidance for its application.
基金This work was supported by the National Key Research and Development Program(2016YFB0901505)the Natural Science Foundation of China(22005190,21938005)+1 种基金the Science&Technology Commission of Shanghai Municipality(19DZ1205500)Zhejiang Key Research and Development Program(2020C01128).
文摘NASICON-type Na_(3)V_(2)(PO_(4))_(3) is a promising electrode material for developing advanced sodium-ion batteries.Preparing Na_(3)V_(2)(PO_(4))_(3) with good performance by a cost-effective and large-scale method is significant for industrial applications.In this work,a porous Na_(3)V_(2)(PO_(4))_(3)/C cathode material with excellent electrochemical performance is successfully prepared by an agar-gel combined with freeze-drying method.The Na_(3)V_(2)(PO_(4))_(3)/C cathode displayed specific capacities of 113.4 mAh·g^(-1),107.0 mAh·g^(-1) and 87.1 mAh·g^(-1) at 0.1 C,1 C and 10 C,respectively.For the first time,the 500-mAh soft-packed symmetrical sodium-ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C electrodes are successfully fabricated.The 500-mAh symmetrical batteries exhibit outstanding low temperature performance with a capacity retention of 83%at 0℃ owing to the rapid sodium ion migration ability and structural stability of Na_(3)V_(2)(PO_(4))_(3)/C.Moreover,the thermal runaway features are revealed by accelerating rate calorimetry(ARC)test for the first time.Thermal stability and safety of the symmetrical batteries are demonstrated to be better than lithium-ion batteries and some reported sodium-ion batteries.Our work makes it clear that the soft-packed symmetrical sodium ion batteries based on Na_(3)V_(2)(PO_(4))_(3)/C have a prospect of practical application in high safety requirement fields.
文摘Although some genes that cause Kallmann syndrome (KS) have been identified by traditional linkage analysis and candidate gene techniques, the syndrome's molecular etiology in the majority of patients remains poorly understood. In this paper, we present the clinical assessments of a consanguineous Hart Chinese family with three KS descendants. To understand the molecular etiology of KS from a genome-wide perspective, we investigated the genome-wide profile of structural variation in this family using the Affymetrix Genome-Wide Human SNP Array 6.0 platform. The results revealed that the three affected individuals had common copy number variants (microdeletions) on chromosomes lp21.1, 2q32.2, 8q21.13, 14q21.2 and Xp22.31. Moreover, the copy number variants on Xp22.31 were located in the intron of KAL 1, which causes X-linked KS. Two PCR assays were performed on these regions to validate the results obtained using the chips. In addition, genomic microdeletions in this region were verified in one of 29 Han Chinese sporadic KS cases and one of four other family cases, but not in 26 Han Chinese sporadic normosmic idiopathic hypogonadotropic hypogonadism cases and 100 unrelated Han Chinese normal controls. Our results provide a novel insight into the relative contributions of certain copy number variants to KS's molecular etiology and generate a list of interesting candidate regions for further studies.
基金financial support by the National Natural Science Foundation of China(91534115)the National Key Research and Development Project(2016YFC1102300)。
文摘A series of ZSM-5@MCM-41 core-shell composite materials prepared via a multi-cycle-sol-gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene,in which both ethylbenzene and para-diethylbenzene(p-DEB)are aimed as the target products.With multi-cycle-sol-gel coating,the external acid sites on the samples are gradually passivated by the inert MCM-41 shell.As a result,the shape selectivity to p-DEB is greatly enhanced.Nevertheless,the coating of mesoporous MCM-41 shell on ZSM-5 accelerates deactivation of the catalyst only due to the dilution effect of ZSM-5 content in the catalyst at the same space velocity,which is a reason that core-shell ZSM-5@MCM-41 will potentially be a practical catalyst in shape selective alkylation of benzene.In order to enhance the yield of p-DEB on ZSM-5@MCM-41,the reaction conditions at the fixed bed reactor including temperature,the molar rate of benzene to ethylene and GHSV,are also optimized.
文摘OBJECTIVE: To summarize Cochrane reviews of acupuncture for neurological disorders, and characteristics of included reviews and studies. DATA SOURCES: A computer-based online search of the Cochrane Library (Issue 7 of 12, July 2010) was performed with the key word "acupuncture" and systematic evaluations for acupuncture for neurological disorders were screened. STUDY SELECTION: Systematic reviews on acupuncture in the treatment of neurological disorders were included, and the characteristics of these reviews were analyzed based on methods recommended by the Cochrane collaboration. MAIN OUTCOME MEASURES: Basic characteristics, methodological quality, main reasons for excluding trials, results and conclusions of Cochrane reviews were assessed. RESULTS: A total of 18 Cochrane systematic reviews were included, including 13 completed reviews and five research protocols. The 13 completed reviews involved 111 randomized controlled trials, including 43 trials (38.7%) conducted in China, 47 trials (42.3%) using sham-acupuncture or placebo as control, 15 trials (13.5%) with relatively high quality, 91 trials (81.9%) reporting data on follow-up. Primary outcomes used in the Cochrane reviews were reported by 65 trials (58.6%), and adverse events were reported in 11 trials (9.9%). Two hundred and eighty three trials were excluded. Two reviews on headache suggested that acupuncture is a valuable non-drug treatment for patients with chronic or recurrent headache, and has better curative effects on migraine compared with preventative drug treatment. CONCLUSION: Of the Cochrane reviews on acupuncture in the treatment of neurological disorders, two reviews evaluating the efficacy of acupuncture in treating headaches drew positive conculsions, while other reviews did not obtain positive conclusions due to a small sample size or low methodological quality. The methodological quality of acupuncture trials needs further improvement.
基金supported by the National Key R&D Program of China(2017YFB0702800)National Natural Science Foundation of China(21802168,21503280,21603277)China Petrochemical Corporation(Sinopec Group)~~
文摘In this contribution,we report the cooperative structure-directing effect of choline hydroxide and aluminosilicate*BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolites for the first time.*BEA zeolites,at variance with any other aluminosilicate zeolites,can serve as heterogeneous seeds for the growth of IWR zeolites and play a cooperative structure-directing role.The crystallization process was investigated using multiple techniques to characterize a series of solid products obtained with various crystallization times.The experiments clearly showed the dissolution of the*BEA zeolite and of an intermediate CDO-type structure.A plausible mechanism for the novel cooperative synthesis has been proposed.The crystallization of the IWR zeolite involves several steps,among which the crucial one is believed to be the reassembly of the building units produced from the decomposition of*BEA zeolite seeds,induced by choline molecules.Having similar structure and common building units(four-,five-,and six-membered rings)with the IWR zeolite,the*BEA zeolite is capable of promoting the reassembly of the building units and can thus play a cooperative structure-directing role.By highlighting the cooperative structure-directing effect of organic molecules and heterogeneous seeds,this study opens up new perspectives for the synthesis of target zeolites that are difficult to prepare by traditional methods.This new synthetic route is also expected to shed light on the discovery of novel zeolites.
基金Talent Training Quality Construction-Cross Training Program for High-level Talents-Practical Training Program(Municipal Level)(PXM2020-014207-000009)Special Project for Beijing New Countryside Construction Research Base in 2019(PXM2019-014207-000016)2020 Connotative Development Quota Project-Funds for Improving the Quality of Talent training-Teaching Team Construction of Agricultural Economics Course Group(5046516642).
文摘Taking the rural residents in Yanqing District of Beijing as the research object,through field investigations and interviews,it is found that the main characteristics,income and expenditure level,preference and cognitive level of rural residents are the factors that affect the dairy consumption behavior of rural residents.Using the bivariate regression model for empirical analysis,it is concluded that rural residents'occupation,monthly average income,purchase expenditure and attitude towards dairy safety have a significant impact on rural residents'dairy consumption behavior,and then relevant constructive suggestions are put forward to guide rural residents'balanced consumption.
基金Supported by Science&Technology Department of Yunnan Province-Kunming Medical University Joint Fund for Applied Basic Research[2017FE468(-001)]NSFC-Yunnan Joint Fund[U1502226].
文摘[Objectives]This paper aimed to prepare derivatives of protopanaxadiol from Panax notoginseng(Burk.)FH Chen with acid anhydrides and study their anti-tumor activity.[Methods]The 3-hydroxyl group of protopanaxadiol was subjected to structural modification and reacted with acid anhydrides to prepare derivatives,in order to improve the anti-tumor activity of protopanaxadiol.None of the five compounds designed and synthesized had been reported in the literature,and they were novel compounds.The anti-tumor activity of the derivatives was studies using MTS method.Taking cisplatin and paclitaxel as positive control drugs,the bioactivity of the compounds 1-5 on anti-tumor cell lines(HL-60 cells,SMMC-7721 cells,A-549 cells,MCF-7 cells and SW480 cells)in vitro was screened.[Results]The compound 5 showed inhibitory effect on HL-60 cells,SMMC-7721 cells and A-549 cells.[Conclusions]The acid anhydride esterification method is simple to operate and easy to control.This study has reference value for the structural modification and anti-tumor activity research of protopanaxadiol from P.notoginseng(Burk.)FH Chen.
基金2019 Special Fund Program of Beijing New Socialist Countryside Construction Research Base(PXM2019-014207-000016)Project of China Agricultural University"Study on Benefit Linkage Mechanism for Agricultural Leading Enterprises Promoting Development of Farmers in the Context of Rural Revitalization Strategy"(201901711110529).
文摘The agricultural leading enterprises and farmers have formed a mutual linkage,mutual restraint,and interdependent benefit linkage mechanism.This paper mainly analyzes the existing problems in the benefit linkage between the agricultural leading enterprises and farmers,and draws on the successful domestic benefit linkage model,and comes up with policy recommendations to provide an effective approach for agricultural leading enterprises to promote development of farmers.
基金Supported by agrant from the National Natural Science Foundation of China(No.30271300).
文摘Objective:To determine whether NF-κB is constitutively activated in human bladder cancer cell and,if so,to deter-mine the invasiveness inhibition of bladder cancer cells by nuclear factor-κB decoy—circular dumbbell oligodeoxynucleotides(CD-ODN).Methods:NF-κBp65 activation was determined by immunohistochemical analysis of formalin-fixed,paraffin-embed-ded specimens from 38 cases of bladder transitional cell carcinoma patients.We quantified nuclear staining of RelA as a marker of NF-κBp65 activation.CD-ODN were transfected into human bladder cancer cell line BIU87 by lipofectamine.Luciferase reporter were applied to detecting NF-κB DNA binding activity.The expression levels of uPA were detected by RT-PCR and the cells’ invasion ability by transwell cell culture chamber.Results:P65 excessive activation existed in tumor cell(P<0.01),the activation degree correlated significantly with the expression of uPA(r=0.89,P<0.01),as well as related to tumor invasion-related clinicopathological features such as lymphatic metastasis(P<0.01)and pathological ranking(P<0.05);After transfection with CD-ODN,the activation of NF-κB in BIU87 cell line was suppressed remarkably,the expression level of uPA was decreased and the cells’ invasiveness was weakened as well.Conclusion:Excessively activated NF-κB is related to tumor progression pos-sibly due to its transcriptional regulation of invasion-related factors such as uPA.CD-ODN can efficiently suppress DNA binding activity of NF-κB to reduce the invasive potency of tumor.
基金Supported by 2019 Special Program of Beijing New Countryside Construction Research Base(PXM2019-014207-000016)2020 Connotation Development Quota Project-Talent Training Quality Improvement Fund-Agricultural Economics Course Group Teaching Team Building(5046516642/035)Talent Cultivation Quality Construction-High-level Talent Cross-Cultivation Plan-Practical Training Plan(Municipal Level)(PXM2020-014207-000009).
文摘As shown in the agricultural development experience of various countries in the world,the agricultural operating entity has become an effective means to increase the agricultural production efficiency and establish a scientific management model.Promoting the continuous improvement of the modern agricultural management system is not only an important means for solving the three rural issues in China,but also a key measure to enhance China's agricultural competitiveness.This paper introduced the basic situation of agricultural operating entities in Japan and Germany,summarized their advanced experience,and finally came up with feasible recommendations for enhancing the competitive advantages of agricultural operating entities in China.