Bovine oocytes are one of the indispensable cells in cattle reproduction and have become a research hot spot in cattle reproduction in recent years.The maturation process of oocytes is mainly regulated by enzymes,horm...Bovine oocytes are one of the indispensable cells in cattle reproduction and have become a research hot spot in cattle reproduction in recent years.The maturation process of oocytes is mainly regulated by enzymes,hormones,cytokines,and other molecules.The factors affecting cattle oocyte maturation have been previously studied to clarify the molecular mechanisms of cattle oocyte maturation.In this review article,phospholipid protein-3-kinase/protein kinase B,mitogen-activated protein kinase/extracellular signal-regulated kinase,Janus kinase/signal transducer and activator of transcription,epidermal growth factor receptor/extracellular signal-regulated kinase,and other signaling pathways related to oocyte maturation are discussed.In addition,the molecular mechanisms of some coding genes(JY-1,FGF-10,CDC20,etc.)and non-coding genes(miRNA,lncRNA,and circRNA)regulating oocyte maturation have been reviewed to provide new ideas for high reproductive performance molecular breeding of high-quality cattle.展开更多
In view of the frequent waterlogging caused by rapid urbanization and the public’s dissatisfaction with the drainage system,the article based on the concept of the green ecological drainage system,constructed the urb...In view of the frequent waterlogging caused by rapid urbanization and the public’s dissatisfaction with the drainage system,the article based on the concept of the green ecological drainage system,constructed the urban green ecological drainage comprehensive simulation research system,and quickly evaluated pipe network operation and surface water of an industrial park under typical rainfall conditions.The results showed that the drainage capacity of the designed green ecological rainwater drainage system reached 100%,and there was no ponding phenomenon,which indicated that the green ecological rainwater drainage system could effectively solve the practical problems of urban drainage.The green ecological rainwater comprehensive simulation research system had good adaptability.The research results provided the scientific theoretical basis and reference significance for planning,designing,constructing,operating,and managing urban rainwater system scientifically and systematically.展开更多
With distinct advantages such as high gravimetric and volumetric capacity(5855 mAh·cm^(-3)and 820mAh·g^(-1)),low redox potential(-0.762 V vs.standard hydrogen electrode(SHE)),high abundance,low toxicity and ...With distinct advantages such as high gravimetric and volumetric capacity(5855 mAh·cm^(-3)and 820mAh·g^(-1)),low redox potential(-0.762 V vs.standard hydrogen electrode(SHE)),high abundance,low toxicity and intrinsic safety of Zn metal anode,Zn-ion batteries have become a potential alternative to Li-ion batteries.However,several challenges still need to be addressed prior to the practical applications of Zn-ion batteries,such as dendrite growth during Zn plating/stripping and interfacial side reactions on the Zn surface.Such issues can be addressed by introducing additives to regulate the components and structures of the electrolyte.In this review,we systematically discussed the core issues of metallic Zn anodes and comprehensively summarized a novel perspective of the regulation mechanism of inhibiting dendrite growth or interfacial side reactions in Zn anodes by introducing additives into aqueous electrolytes.Furthermore,some discussions and prospects for aqueous Zn ion batteries(AZIBs)are presented for future research.展开更多
In traditional Nd-Fe-B-based sintered magnets,the composition,role of each element and microstruc-tures have been extensively investigated globally since they were invented in 1983.However,the effects of boron(B)conte...In traditional Nd-Fe-B-based sintered magnets,the composition,role of each element and microstruc-tures have been extensively investigated globally since they were invented in 1983.However,the effects of boron(B)content and post-sinter annealing(PSA)on the microstructure and magnetic properties have been least studied so far and the relative mechanisms are not yet clear.In this paper,we investigated the influence of B on the magnetic performance and microstructure of Nd-Fe-B sintered magnets origi-nally containing copper(Cu),gallium(Ga)and titanium(Ti).It is shown that the intrinsic coercivity has a substantial increment of 2.86 kOe and the remanence has a slight reduction of 0.16 kGs when B content is reduced from 0.980 wt.%to 0.900 wt.%.Moreover,there is a coercivity increment of 27.3%and 65.3%for samples with 0.980 wt.%and 0.900 wt.%B content after PSA,respectively.It is shown that the im-pacts of B content and PSA are significant and their regulation mechanisms are worthwhile to be studied systematically.Furthermore,it is revealed by microstructural analysis that high coercivity of the sample with 0.900 wt.%B after PSA results from the uniform distribution of Ga,Cu,Nd,and the formation of RE 6(Fe,M)14(RE=Pr,Nd,M=Cu,Ga)compound in triple junction phases.The dilution of Fe content in grain boundary phases(GB phases)also plays an important role.It is found out that decrease of the re-manence is mainly due to reduction of the matrix phase and c-axis alignment degree.In this study,we explored a new path to develop Nd-Fe-B-based sintered magnets with high comprehensive properties by novel approaches through varying B content,PSA technique and co-adding trace elements.展开更多
Phase change materials(PCMs)have remarkable energy storage capacity and promising applications in the field of thermal control of electronic products.The problem of thermal property improvement and heat transfer of PC...Phase change materials(PCMs)have remarkable energy storage capacity and promising applications in the field of thermal control of electronic products.The problem of thermal property improvement and heat transfer of PCMs in metal-foam heatsinks is an important task for thermal management of electronic components.Mixed paraffin samples were prepared by mixing appropriate proportions of paraffin(mass)at various temperatures.Differential scanning calorimetry analysis revealed that the maximum enthalpy of 206.3 J/g is obtained by mixing 20%of 17°C liquid paraffin and 80%of 29℃ solid paraffin.Heating and cooling cycling tests revealed that mixed paraffin exhibits excellent thermal stability and that the regulation method marginally affects thermal stability.Moreover,composites were prepared by embedding PCM into a copper foam by melt impregnation.The thermal conductivity of the composites increased to 4.35 W/(m K),corresponding to 20 times its original value.In addition,density functional theory and experimental results were in good agreement,indicating that the regulation method is practical and effective.展开更多
The morphology regulation of hollow silica microspheres is significant for their properties and applications. In this paper, hollow silica microspheres were formed through the hydrolysis and condensation reaction of t...The morphology regulation of hollow silica microspheres is significant for their properties and applications. In this paper, hollow silica microspheres were formed through the hydrolysis and condensation reaction of tetraethyl orthosilicate(TEOS) at the interface of the emulsion droplet templates composed of liquid paraffin and TEOS, followed by dissolving paraffin with ethanol. The effects of various factors including the emulsifier structure and content, TEOS content, catalyst type, and the ethanol content in the continuous water phase on the particle size, shell thickness and morphology of the prepared hollow silica microspheres were studied in detail. The results show that the diffusion and contact of TEOS and water molecules as well as the hydrolysis condensation reaction of TEOS at the oil-water interface are two critical processes for the synthesis and morphological regulation of hollow silica microspheres. Cationic emulsifier with a hydrophobic chain of appropriate length is the prerequisite for the successful synthesis of hollow silica microspheres. The ethanol content in water phase is the dominant factor to determine the average diameter of hollow microspheres, which can vary from 96 nm to 660 nm with the increase of the volume ratio of alcohol-water from 0 to 0.7. The silica wall thickness varies with the content and the hydrophobic chain length of the emulsifier, TEOS content, and the activity of the catalyst. The component of the soft template will affect the morphology of the silica wall. When the liquid paraffin is replaced by cyclohexane, hollow microspheres with fibrous mesoporous silica wall are fabricated. This work not only enriches the basic theory of interfacial polymerization in the emulsion system, but also provides ideas and methods for expanding the morphology and application of hollow silica microspheres.展开更多
Although Fe-Ni combination performs well in transition metal-based oxygen evolution reaction(OER)electrocatalysts,there are lack of clear and general regulations mechanism to fully play the synergistic catalytic effec...Although Fe-Ni combination performs well in transition metal-based oxygen evolution reaction(OER)electrocatalysts,there are lack of clear and general regulations mechanism to fully play the synergistic catalytic effect.Here,we made the utmost of the interaction of Fe–Ni heteroatomic pair to obtain a highly active Fe-Ni(oxy)hydroxide catalytic layer on iron foam(IF)and nickel foam(NF)by in-situ electrochemical deposition and rapid surface reconstruction,which only required 327 and 351 mV overpotential to provide a large current of 1,000 mA·cm^(−2),respectively.The results confirm that the moderate Ni-rich heteroatomic bonding(Ni–O–Fe–O–Ni)formed by adjusting the Ni/Fe ratio on the catalyst surface is important to offer predominant OER performance.Fe is a key component that enhances OER activity of Ni(O)OH,but Fe-rich structural surface formed by Fe–O–Ni–O–Fe bonding is not ideal.Finally,the remarkable oxygen evolution performance of the prepared Ni2Fe(O)OH/IF and FeNi2(O)OH/NF can be chalked up to the optimized electronic structure of Fe–Ni heteroatomic bonding,the efficient gas spillover,the fast electron transport,and nanosheet clusters morphology.In summary,our work suggests a comprehensive regulation mechanism for the construction of efficient Fe-Ni(oxy)hydroxide catalytic layer on inexpensive,stable,and self-supporting metallic material surface.展开更多
How to balance rice resistance and yield is an important issue in rice breeding.Plants with mutated necrotic lesion genes often have persistent broad-spectrum resistance,but this broad-spectrum resistance usually come...How to balance rice resistance and yield is an important issue in rice breeding.Plants with mutated necrotic lesion genes often have persistent broad-spectrum resistance,but this broad-spectrum resistance usually comes at the expense of yield.Currently,many necrotic lesion mutants in rice have been identified,and these genes are involved in disease resistance pathways.This review provides a detailed introduction to the characteristics,classification,and molecular mechanisms of necrotic lesion formation.Additionally,we review the molecular regulatory pathways of genes involved in rice disease resistance.Concurrently,we summarize the relationship between resistance and yield in rice using newly developed gene editing methods.We discuss a rational and precise breeding strategy to better utilize molecular design technology for breeding disease-resistant and high-yield rice varieties.展开更多
Membrane tension plays a crucial role in various fundamental cellular processes,with one notable example being the T cell-mediated elimination of tumor cells through perforin-induced membrane perforation by amplifying...Membrane tension plays a crucial role in various fundamental cellular processes,with one notable example being the T cell-mediated elimination of tumor cells through perforin-induced membrane perforation by amplifying cellular force.However,the mechanisms governing the regulation of biomolecular activities at the cell interface by membrane tension remain elusive.In this study,we investigated the correlation between membrane tension and poration activity of melittin,a prototypical pore-forming peptide,using dynamic giant unilamellar vesicle leakage assays combined with flickering tension analysis,molecular dynamics simulations,and live cell assays.The results demonstrate that an increase in membrane tension enhances the activity of melittin,particularly near its critical pore-forming concentration.Moreover,peptide actions such as binding,insertion,and aggregation in the membrane further influence the evolution of membrane tension.Live cell experiments reveal that artificially enhancing membrane tension effectively enhances melittin’s ability to induce pore formation and disrupt membranes,resulting in up to a ten-fold increase in A549 cell mortality when exposed to a concentration of 2.0-μg·mL^(-1)melittin.Our findings elucidate the relationship between membrane tension and the mechanism of action as well as pore-forming efficiency of melittin,while providing a practical mechanical approach for regulating functional activity of molecules at the cell-membrane interface.展开更多
3D printing is widely adopted to quickly produce rock mass models with complex structures in batches,improving the consistency and repeatability of physical modeling.It is necessary to regulate the mechanical properti...3D printing is widely adopted to quickly produce rock mass models with complex structures in batches,improving the consistency and repeatability of physical modeling.It is necessary to regulate the mechanical properties of 3D-printed specimens to make them proportionally similar to natural rocks.This study investigates mechanical properties of 3D-printed rock analogues prepared by furan resin-bonded silica sand particles.The mechanical property regulation of 3D-printed specimens is realized through quantifying its similarity to sandstone,so that analogous deformation characteristics and failure mode are acquired.Considering similarity conversion,uniaxial compressive strength,cohesion and stress–strain relationship curve of 3D-printed specimen are similar to those of sandstone.In the study ranges,the strength of 3D-printed specimen is positively correlated with the additive content,negatively correlated with the sand particle size,and first increases then decreases with the increase of curing temperature.The regulation scheme with optimal similarity quantification index,that is the sand type of 70/140,additive content of 2.5‰and curing temperature of 81.6℃,is determined for preparing 3D-printed sandstone analogues and models.The effectiveness of mechanical property regulation is proved through uniaxial compression contrast tests.This study provides a reference for preparing rock-like specimens and engineering models using 3D printing technology.展开更多
TRPML1 channel is a non-selective group-2 transient receptor potential (TRP) channel with Ca2+ permeability. Located mainly in late endosome and lysosome of all mammalian cell types, TRPML1 is indispensable in the ...TRPML1 channel is a non-selective group-2 transient receptor potential (TRP) channel with Ca2+ permeability. Located mainly in late endosome and lysosome of all mammalian cell types, TRPML1 is indispensable in the processes of endocytosis, membrane trafficking, and lysosome biogenesis. Mutations of TRPML1 cause a severe lysosomal storage disorder called mucolipidosis type IV (MLIV). In the present study, we determined the cryo-electron microscopy (cryo-EM) structures of Mus musculus TRPML1 (mTRPMLI) in lipid nanodiscs and Amphipols. Two distinct states of mTRPML1 in Amphipols are added to the closed state, on which could represent two different confirmations upon activation and regulation. The polycystin-mucolipin domain (PMD) may sense the luminal/extracellular stimuli and undergo a "move upward" motion during endocytosis, thus triggering the overall conformational change in TRPMLI. Based on the structural comparisons, we propose TRPML1 is regulated by pH, Ca2+, and phosphoinosi- tides in a combined manner so as to accommodate the dynamic endocytosis process.展开更多
The structure design,performance analysis,and process optimization of CNT/MOF-derived hierarchical composite play an important role in the development of high-performance microwave absorbing materi-als.Herein,the prep...The structure design,performance analysis,and process optimization of CNT/MOF-derived hierarchical composite play an important role in the development of high-performance microwave absorbing materi-als.Herein,the preparation,morphology evolution,and electromag-netic wave absorption mechanism of CNT/MOF-derived hierarchical composite were systematically investigated.The regulation mechan-ism was revealed by studying the changes in the morphological characteristics,electromagnetic properties,and microwave absorbing performance of CNT/MOF-derived hierarchical composite under differ-ent process parameters.The results show that the morphological characteristics and interface bonding between CNT and MOF have a great impact on the absorptive capacity.The composite with com-position of 0.28Co/0.26Fe has a maximum absorption of−46 dB at 8.6 GHz and a thickness of 4 mm.In addition,the absorption band with reflection loss values of less than−20 dB can be operated with this thickness between 7.15 and 10.18 GHz,showing excellent absorbing ability and electromagnetic wave bandwidth.The regulation mechan-ism of CNT/MOF-derived hierarchical composite mainly depends on the effect of Lorentz force,the ion disorder of CoO-Fe_(2)O_(3) heterojunc-tion,and the spin polarization mechanism of free electrons.This study further improves the corresponding theoretical basis and new design principles,which provides technical support for the development of high-performance absorbing materials.展开更多
Class V myosin, one of the most ancient types of myosin, plays a key role in intracellular trafficking. Mammalian cells have three isoforms of myosin V, named Myo5a, Myo5b,
Drought stress is an important factor affecting plant growth and development.It will provide a theoretical basis for cultivating new stress-resistant varieties and improving water utilization rate of plants by studyin...Drought stress is an important factor affecting plant growth and development.It will provide a theoretical basis for cultivating new stress-resistant varieties and improving water utilization rate of plants by studying the regulation mechanism of osmotic adjustment and water transportation under drought stress,and understanding the physiological and biochemical characteristics and stress resistance mechanism.展开更多
As vegetation are closely related to soil erosion,hydrodynamic parameter changes under various vegetation pattern conditions can be used as an important basis for the research of the soil erosion mechanism.Through ups...As vegetation are closely related to soil erosion,hydrodynamic parameter changes under various vegetation pattern conditions can be used as an important basis for the research of the soil erosion mechanism.Through upstream water inflow experiments conducted on a loess hillslope,how the vegetation pattern influences the hydrodynamic processes of sediment transport was analyzed.The results show that the placement of a grass strip on the lower upslope can effectively reduce runoff erosion by 69%,relying on the efficiency of regulated hydrodynamic process.The effective location of grass strip for hillslope alleviating erosion is on the lower part of the upslope,mainly due to the grass strip measure used to regulate the hydrodynamic system.As a result,the underlying surface runoff resistance is increased by 5 times,runoff shear stress is decreased by more than 90%,and runoff power decreased by over 92%.The measure greatly separates the scouring energy of surface runoff that acts on the slope soil.Therefore,the use of grass strips effectively decreases the energy of runoff flowing along the slope,eliminating soil erosion to a great extent and thereby achieving a better regulation of hydrodynamic processe.展开更多
The in-situ oxidation of manganese sulfate solution with H2O_(2),sodium hypochlorite,potassium permanganate and oxygen as oxidants was investigated by means of SEM,EDS,XRD,BET and infrared analysis,and the effects of ...The in-situ oxidation of manganese sulfate solution with H2O_(2),sodium hypochlorite,potassium permanganate and oxygen as oxidants was investigated by means of SEM,EDS,XRD,BET and infrared analysis,and the effects of different oxidants on the morphology,phase composition,surface properties and specific surface area of manganese oxides were investigated.The experimental results show that the diameter of manganese oxide particles prepared with H_(2)O_(2)is the smallest,about 50 nm,and the specific surface area is the largest,63.8764 m^(2)/g.It has the advantages of abundant surface hydroxyl groups,no introduction of other impurities and large adsorption potential.It is most suitable to be used as an oxidant for oxidizing manganese sulfate solution to prepare manganese oxide by in-situ oxidation.Nano manganese oxide prepard by H_(2)O_(2)in-situ oxidation method is used as adsorbent to adsorb cobalt and nickel impurities in manganese sulfate.When the reaction pH is 6,the reaction time is 30min and the amount of adsorbent is 1.0 g,the adsorption rates of cobalt and nickel impurities in 100ml manganese sulfate solution are 97.59%and 97.67%,respectively.The residual amounts of cobalt and nickel meet the industrial process standard of first-class products(Co,Ni w/%≤0.005)of high-purity manganese sulfate(Hg/t4823-2015)for batteries.The study plays a guiding role in the preparation and regulation of manganese oxide,and provides a new method with high efficiency,purity and adsorbent availability for the preparation of high-purity manganese sulfate solution.展开更多
Plant AT-rich sequence and zinc binding(PLATZ)transcription factors are a class of plant specific zincdependent DNA-binding proteins that function in abiotic stress response and plant development.In this study,31 GmPL...Plant AT-rich sequence and zinc binding(PLATZ)transcription factors are a class of plant specific zincdependent DNA-binding proteins that function in abiotic stress response and plant development.In this study,31 GmPLATZ genes were identified in soybean.GmPLATZ17 was down-regulated by drought and exogenous abscisic acid.Transgenic Arabidopsis and soybean hairy roots overexpressing GmPLATZ17 showed drought sensitivity and inhibition of stress-associated gene transcription.In contrast,suppressed expression of GmPLATZ17 led to increased drought tolerance in transgenic soybean hairy roots.The GmPLATZ17 protein was verified to interact physically with the GmDREB5 transcription factor,and overexpression of GmDREB5 increased drought tolerance in soybean hairy roots.Interaction of GmPLATZ17 with GmDREB5 was shown to interfere with the DRE-binding activity of GmDREB5,suppressing downstream stress-associated gene expression.These results show that GmPLATZ17 inhibits drought tolerance by interacting with GmDREB5.This study sheds light on PLATZ transcription factors and the function of GmPLATZ17 in regulating drought sensitivity.展开更多
The blood–brain barrier(BBB)is a structural and functional barrier necessary for brain homeostasis,and it plays an important role in the realization of neural function and in protecting the brain from damage by circu...The blood–brain barrier(BBB)is a structural and functional barrier necessary for brain homeostasis,and it plays an important role in the realization of neural function and in protecting the brain from damage by circulating toxins and pathogens.However,the extremely dense BBB also severely limits the transport of molecules across it,which is a great hindrance to the diagnosis and treatment of central nervous system(CNS)diseases.This paper reports a new method for controllable opening of the BBB,based on the gigahertz acoustic streaming(AS)generated by a bulk acoustic wave resonant device.By adjusting the input power and working distance of the device,AS with tunable flow rate can be generated to disrupt tight junction proteins(TJs)between endothelial cells.The results obtained with this method show that the gigahertz AS promotes the penetration of dextran molecules with different molecular weights across the BBB.This work provides a new platform for studying the mechanical regulation of BBB by fluid shear forces and a new method for improving the efficiency of drug delivery.展开更多
BACKGROUND:It has been confirmed that c-fos expression increased markedly in hypothalamic paraventricular nucleus(PVN)during asthmatic attack in rats,and PVN has extensive physiological functions,involving in the regu...BACKGROUND:It has been confirmed that c-fos expression increased markedly in hypothalamic paraventricular nucleus(PVN)during asthmatic attack in rats,and PVN has extensive physiological functions,involving in the regulation of respiratory system,etc.OBJECTIVE:To observe the alteration of electroencephalogram(EEG)and power spectra in PVN during the asthmatic attack,and the alteration of lung function and diaphragmatic muscle discharge after bilateral PVN lesion in asthmatic rats.DESIGN:A randomized control study.SETTING:Laboratory of Physiology and Pharmacology,School of Basic Medical Sciences,Southeast University.MATERIALS:Forty-eight male adult SD rats of 260-300 g were used.The rats were randomly divided into 6 groups(n=8):control group,asthma group,electrolytic lesion of PVN group,KA-induced lesion of PVN group,sham electrolytic lesion of PVN group and sham kainic acid(KA)-induced lesion of PVN group.KA,chicken ovalbumin and aluminum hydroxide were purchased from American Sigma Company.Bordetella pertussis vaccine(Institute of Biological Products of Shanghai);stereotaxic apparatus(JiangwanⅡ,China);lesion-producing device(YC-2 programmable stimulato,Chengdu Instrument Company);MD2000 signal processing system(Nanjing Medical School);data acquisition system(RM6240B,Chengdu Instrument Company).METHODs:The experiments were carried out in the Laboratory of Physiology and Pharmacology,School of Basic Medical Sciences,Southeast University from January to August in 2006.①Rats except for control group were sensitized with an intraperitoneal injection of 100 mg chicken ovalbumin and 100 mg aluminum hydroxide and Bordetella pertussis vaccine containing 5×10^(9) heat-killed in 1 mL of sterile saline.From the fifteenth to seventeenth days rats received three times aerosolized ovalbumin challenge.In rats of the control group and asthma group three steel electrodes were placed into the left PVN(AP-1.8 mm,LR 0.4 mm,OH-7.9 mm),parietal cortex and subcutaneous tissue in lower limb.Lung function tests were carried out simultaneously.Small holes were drilled in the skull to introduce a concentric bipolar electrode in the direction of the PVN in order to perform electrolytic lesion.The electrodes were connected to a lesion-producing device and a current of 1.0-1.5 mA was passed over a period of 10-15 s on each side of the PVN.The rats received 0.5μg/0.5μL of KA in phosphate buffer(0.1 mol/L,pH 7.4),and the speed of infusion was 0.1μL per minute in order to perform KA-induced lesion of PVN.②Three days after operation of lesion,lung function tests were carried out.All the electrode and transducer were connected with data acquisition system.This technique yielded airway resistance(Raw),dynamic compliance(Cdyn),the expiratory time(Te)/the inspiratory time(Ti),minute ventilation volume(MVV),EMGdi frequency and EMGdi integral.③The differences of the measurement data were compared using the t test.MAIN OUTCOME MEASURES:①The alteration of EEG and power spectrum of PVN during asthmatic attack in sensitized rats;②The effects of electrolytic lesion or KA-induced lesion of PVN on lung function in asthmatic rats.RESULTS:All the 48 rats were involved in the analysis of results.①Alteration of EEG and power spectrum:Five minutes after injection of ovalbumin into caudal vena,the breathing rate of the rat was obviously speeded up and the total power spectrum was increased[(18476.71±2140.94),(13838.75±2983.26)mV^(2),P<0.01],the percentage of theδpower andθpower decreased significantly(P<0.01),while the percentage ofαpower andβ1 power were enhanced(P<0.05,0.01).Ten minutes after injection,the EEG power spectrum of PVN further shifted rightward,the total power gradually increased(P<0.01)which suggesting that the intensive hypersynchrony activities of PVN neurons.The percentage ofδpower was decreased significantly(P<0.01),but theα,β1 andβ2 were increased(P<0.01).Twenty-five minutes later,the breathing movements became steady,and the EEG power spectrum of PVN returned to the control level step by step.②The alteration of lung function was detected during asthmatic attack after electrolytic lesion or KA-induced lesions of PVN respectively.It was found that EMGdi frequency,Te/Ti and RL were all decreased(P<0.01),EMGdi integral,MVV and Cdyn were all enhanced(P<0.01),while there were no significant changes in the sham surgery group(P>0.05).CONCLUSION:The excitability of PVN is increased during the asthmatic attack.PVN plays a key role in the regulation of asthma.Both electrolytic and KA lesions of PVN can significantly relieve the asthmatic symptoms of rats,and improve their lung function.展开更多
The capacity for adult axons to regenerate after injury is diminished compared with developing axons.In the case of central nervous system(CNS)axons,injury causes a total failure to regenerate.This failure is due to...The capacity for adult axons to regenerate after injury is diminished compared with developing axons.In the case of central nervous system(CNS)axons,injury causes a total failure to regenerate.This failure is due to both the intrinsic developmental decrease in growth capacity and the extrinsic inhibitory environment formed because of the injury.展开更多
基金supported by grants from the Key Research and Development Plan Project of Ningxia Hui Autonomous Region(2021BEF02029)the Key Research and Development Plan Project(Talent Introduction Project)of Ningxia Hui Autonomous Region(2020BEB04006)the Introducing Talent Research Startup Project of Ningxia University(030900002254).
文摘Bovine oocytes are one of the indispensable cells in cattle reproduction and have become a research hot spot in cattle reproduction in recent years.The maturation process of oocytes is mainly regulated by enzymes,hormones,cytokines,and other molecules.The factors affecting cattle oocyte maturation have been previously studied to clarify the molecular mechanisms of cattle oocyte maturation.In this review article,phospholipid protein-3-kinase/protein kinase B,mitogen-activated protein kinase/extracellular signal-regulated kinase,Janus kinase/signal transducer and activator of transcription,epidermal growth factor receptor/extracellular signal-regulated kinase,and other signaling pathways related to oocyte maturation are discussed.In addition,the molecular mechanisms of some coding genes(JY-1,FGF-10,CDC20,etc.)and non-coding genes(miRNA,lncRNA,and circRNA)regulating oocyte maturation have been reviewed to provide new ideas for high reproductive performance molecular breeding of high-quality cattle.
文摘In view of the frequent waterlogging caused by rapid urbanization and the public’s dissatisfaction with the drainage system,the article based on the concept of the green ecological drainage system,constructed the urban green ecological drainage comprehensive simulation research system,and quickly evaluated pipe network operation and surface water of an industrial park under typical rainfall conditions.The results showed that the drainage capacity of the designed green ecological rainwater drainage system reached 100%,and there was no ponding phenomenon,which indicated that the green ecological rainwater drainage system could effectively solve the practical problems of urban drainage.The green ecological rainwater comprehensive simulation research system had good adaptability.The research results provided the scientific theoretical basis and reference significance for planning,designing,constructing,operating,and managing urban rainwater system scientifically and systematically.
基金supported by the National Natural Science Foundation of China(Nos.21831006,21975244,22278042 and 22008014)the Research Initiation Fee of Changzhou University(No.ZMF23020030)+3 种基金Changzhou Young Scientific and Technological Talents Promotion ProjectQing Lan Project of Jiangsu Province and the ScienceTechnology Project of Changzhou City(No.CJ2022002)the Introduction and Cultivation of Leading Innovative Talents Foundation of Changzhou,Jiangsu Province(No.CQ20220093)。
文摘With distinct advantages such as high gravimetric and volumetric capacity(5855 mAh·cm^(-3)and 820mAh·g^(-1)),low redox potential(-0.762 V vs.standard hydrogen electrode(SHE)),high abundance,low toxicity and intrinsic safety of Zn metal anode,Zn-ion batteries have become a potential alternative to Li-ion batteries.However,several challenges still need to be addressed prior to the practical applications of Zn-ion batteries,such as dendrite growth during Zn plating/stripping and interfacial side reactions on the Zn surface.Such issues can be addressed by introducing additives to regulate the components and structures of the electrolyte.In this review,we systematically discussed the core issues of metallic Zn anodes and comprehensively summarized a novel perspective of the regulation mechanism of inhibiting dendrite growth or interfacial side reactions in Zn anodes by introducing additives into aqueous electrolytes.Furthermore,some discussions and prospects for aqueous Zn ion batteries(AZIBs)are presented for future research.
基金supported by the National Natural Science Foundation of China(Nos.52371188,52061015)Young Talents Program of Jiangxi Provincial Major Discipline Academic and Technical Leaders Training Program(No.20212BCJ23008)+5 种基金Jiangxi Province Double Thousand Plan(No.jxsq2023201085),Jiangxi Provincial Natural Science Foundation(No.20212BAB214018)the Program of Qingjiang Excellent Young Talents of Jiangxi University of Science and Technology(No.JXUSTQJYX2020003)National College Students Innovation and Entrepreneurship Training Program(No.202110407013)Technology Program of Fujian Province(Nos.2020H6027,2021T3063)Self-deployed Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(No.E055B002)the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021–3).
文摘In traditional Nd-Fe-B-based sintered magnets,the composition,role of each element and microstruc-tures have been extensively investigated globally since they were invented in 1983.However,the effects of boron(B)content and post-sinter annealing(PSA)on the microstructure and magnetic properties have been least studied so far and the relative mechanisms are not yet clear.In this paper,we investigated the influence of B on the magnetic performance and microstructure of Nd-Fe-B sintered magnets origi-nally containing copper(Cu),gallium(Ga)and titanium(Ti).It is shown that the intrinsic coercivity has a substantial increment of 2.86 kOe and the remanence has a slight reduction of 0.16 kGs when B content is reduced from 0.980 wt.%to 0.900 wt.%.Moreover,there is a coercivity increment of 27.3%and 65.3%for samples with 0.980 wt.%and 0.900 wt.%B content after PSA,respectively.It is shown that the im-pacts of B content and PSA are significant and their regulation mechanisms are worthwhile to be studied systematically.Furthermore,it is revealed by microstructural analysis that high coercivity of the sample with 0.900 wt.%B after PSA results from the uniform distribution of Ga,Cu,Nd,and the formation of RE 6(Fe,M)14(RE=Pr,Nd,M=Cu,Ga)compound in triple junction phases.The dilution of Fe content in grain boundary phases(GB phases)also plays an important role.It is found out that decrease of the re-manence is mainly due to reduction of the matrix phase and c-axis alignment degree.In this study,we explored a new path to develop Nd-Fe-B-based sintered magnets with high comprehensive properties by novel approaches through varying B content,PSA technique and co-adding trace elements.
基金supported by the National Natural Science Foundation of China(Grant No.51976126)the Natural Science Foundation of Shanghai(Grant Nos.22ZR1442700,22WZ2503100,and 20ZR1438600)Shanghai Municipal Science and Technology Committee of Shanghai Outstanding Academic Leaders Plan(Grant No.21XD1402400)。
文摘Phase change materials(PCMs)have remarkable energy storage capacity and promising applications in the field of thermal control of electronic products.The problem of thermal property improvement and heat transfer of PCMs in metal-foam heatsinks is an important task for thermal management of electronic components.Mixed paraffin samples were prepared by mixing appropriate proportions of paraffin(mass)at various temperatures.Differential scanning calorimetry analysis revealed that the maximum enthalpy of 206.3 J/g is obtained by mixing 20%of 17°C liquid paraffin and 80%of 29℃ solid paraffin.Heating and cooling cycling tests revealed that mixed paraffin exhibits excellent thermal stability and that the regulation method marginally affects thermal stability.Moreover,composites were prepared by embedding PCM into a copper foam by melt impregnation.The thermal conductivity of the composites increased to 4.35 W/(m K),corresponding to 20 times its original value.In addition,density functional theory and experimental results were in good agreement,indicating that the regulation method is practical and effective.
基金supported by the National Natural Science Foundation of China (Nos. 51973205, 51773189)Zhuhai Industry-University-Research Institute Collaboration&Basic and Applied Basic Research Project (No. ZH_(2)2017001210059PWC)the Fundamental Research Funds for the Central Universities (Nos.WK9110000066, WK3450000005 and WK3450000006)。
文摘The morphology regulation of hollow silica microspheres is significant for their properties and applications. In this paper, hollow silica microspheres were formed through the hydrolysis and condensation reaction of tetraethyl orthosilicate(TEOS) at the interface of the emulsion droplet templates composed of liquid paraffin and TEOS, followed by dissolving paraffin with ethanol. The effects of various factors including the emulsifier structure and content, TEOS content, catalyst type, and the ethanol content in the continuous water phase on the particle size, shell thickness and morphology of the prepared hollow silica microspheres were studied in detail. The results show that the diffusion and contact of TEOS and water molecules as well as the hydrolysis condensation reaction of TEOS at the oil-water interface are two critical processes for the synthesis and morphological regulation of hollow silica microspheres. Cationic emulsifier with a hydrophobic chain of appropriate length is the prerequisite for the successful synthesis of hollow silica microspheres. The ethanol content in water phase is the dominant factor to determine the average diameter of hollow microspheres, which can vary from 96 nm to 660 nm with the increase of the volume ratio of alcohol-water from 0 to 0.7. The silica wall thickness varies with the content and the hydrophobic chain length of the emulsifier, TEOS content, and the activity of the catalyst. The component of the soft template will affect the morphology of the silica wall. When the liquid paraffin is replaced by cyclohexane, hollow microspheres with fibrous mesoporous silica wall are fabricated. This work not only enriches the basic theory of interfacial polymerization in the emulsion system, but also provides ideas and methods for expanding the morphology and application of hollow silica microspheres.
基金the National Natural Science Foundation of China(No.52174283)the Shandong Provincial Natural Science Foundation(No.ZR2020MB044)Postgraduate Innovation Engineering Project of China University of Petroleum(East China)(No.YCX2021147).
文摘Although Fe-Ni combination performs well in transition metal-based oxygen evolution reaction(OER)electrocatalysts,there are lack of clear and general regulations mechanism to fully play the synergistic catalytic effect.Here,we made the utmost of the interaction of Fe–Ni heteroatomic pair to obtain a highly active Fe-Ni(oxy)hydroxide catalytic layer on iron foam(IF)and nickel foam(NF)by in-situ electrochemical deposition and rapid surface reconstruction,which only required 327 and 351 mV overpotential to provide a large current of 1,000 mA·cm^(−2),respectively.The results confirm that the moderate Ni-rich heteroatomic bonding(Ni–O–Fe–O–Ni)formed by adjusting the Ni/Fe ratio on the catalyst surface is important to offer predominant OER performance.Fe is a key component that enhances OER activity of Ni(O)OH,but Fe-rich structural surface formed by Fe–O–Ni–O–Fe bonding is not ideal.Finally,the remarkable oxygen evolution performance of the prepared Ni2Fe(O)OH/IF and FeNi2(O)OH/NF can be chalked up to the optimized electronic structure of Fe–Ni heteroatomic bonding,the efficient gas spillover,the fast electron transport,and nanosheet clusters morphology.In summary,our work suggests a comprehensive regulation mechanism for the construction of efficient Fe-Ni(oxy)hydroxide catalytic layer on inexpensive,stable,and self-supporting metallic material surface.
基金supported by the National Natural Science Foundation of China(Grant Nos.31971872,32372118,32071993)the QIAN Qian Academician Workstation,the Specific Research fund of the Innovation Platform for Academicians of Hainan Province,China(Grant No.YSPTZX202303)the Key Research and Development Program of Zhejiang Province,China(Grant No.2021C02056)。
文摘How to balance rice resistance and yield is an important issue in rice breeding.Plants with mutated necrotic lesion genes often have persistent broad-spectrum resistance,but this broad-spectrum resistance usually comes at the expense of yield.Currently,many necrotic lesion mutants in rice have been identified,and these genes are involved in disease resistance pathways.This review provides a detailed introduction to the characteristics,classification,and molecular mechanisms of necrotic lesion formation.Additionally,we review the molecular regulatory pathways of genes involved in rice disease resistance.Concurrently,we summarize the relationship between resistance and yield in rice using newly developed gene editing methods.We discuss a rational and precise breeding strategy to better utilize molecular design technology for breeding disease-resistant and high-yield rice varieties.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274307,32230063,21774092,and 12347102)the Basic and Applied Basic Research Foundation of Guangdong Province,China(Grant No.2023A1515011610).
文摘Membrane tension plays a crucial role in various fundamental cellular processes,with one notable example being the T cell-mediated elimination of tumor cells through perforin-induced membrane perforation by amplifying cellular force.However,the mechanisms governing the regulation of biomolecular activities at the cell interface by membrane tension remain elusive.In this study,we investigated the correlation between membrane tension and poration activity of melittin,a prototypical pore-forming peptide,using dynamic giant unilamellar vesicle leakage assays combined with flickering tension analysis,molecular dynamics simulations,and live cell assays.The results demonstrate that an increase in membrane tension enhances the activity of melittin,particularly near its critical pore-forming concentration.Moreover,peptide actions such as binding,insertion,and aggregation in the membrane further influence the evolution of membrane tension.Live cell experiments reveal that artificially enhancing membrane tension effectively enhances melittin’s ability to induce pore formation and disrupt membranes,resulting in up to a ten-fold increase in A549 cell mortality when exposed to a concentration of 2.0-μg·mL^(-1)melittin.Our findings elucidate the relationship between membrane tension and the mechanism of action as well as pore-forming efficiency of melittin,while providing a practical mechanical approach for regulating functional activity of molecules at the cell-membrane interface.
基金the National Natural Science Foundation of China(Nos.51988101 and 42007262).
文摘3D printing is widely adopted to quickly produce rock mass models with complex structures in batches,improving the consistency and repeatability of physical modeling.It is necessary to regulate the mechanical properties of 3D-printed specimens to make them proportionally similar to natural rocks.This study investigates mechanical properties of 3D-printed rock analogues prepared by furan resin-bonded silica sand particles.The mechanical property regulation of 3D-printed specimens is realized through quantifying its similarity to sandstone,so that analogous deformation characteristics and failure mode are acquired.Considering similarity conversion,uniaxial compressive strength,cohesion and stress–strain relationship curve of 3D-printed specimen are similar to those of sandstone.In the study ranges,the strength of 3D-printed specimen is positively correlated with the additive content,negatively correlated with the sand particle size,and first increases then decreases with the increase of curing temperature.The regulation scheme with optimal similarity quantification index,that is the sand type of 70/140,additive content of 2.5‰and curing temperature of 81.6℃,is determined for preparing 3D-printed sandstone analogues and models.The effectiveness of mechanical property regulation is proved through uniaxial compression contrast tests.This study provides a reference for preparing rock-like specimens and engineering models using 3D printing technology.
文摘TRPML1 channel is a non-selective group-2 transient receptor potential (TRP) channel with Ca2+ permeability. Located mainly in late endosome and lysosome of all mammalian cell types, TRPML1 is indispensable in the processes of endocytosis, membrane trafficking, and lysosome biogenesis. Mutations of TRPML1 cause a severe lysosomal storage disorder called mucolipidosis type IV (MLIV). In the present study, we determined the cryo-electron microscopy (cryo-EM) structures of Mus musculus TRPML1 (mTRPMLI) in lipid nanodiscs and Amphipols. Two distinct states of mTRPML1 in Amphipols are added to the closed state, on which could represent two different confirmations upon activation and regulation. The polycystin-mucolipin domain (PMD) may sense the luminal/extracellular stimuli and undergo a "move upward" motion during endocytosis, thus triggering the overall conformational change in TRPMLI. Based on the structural comparisons, we propose TRPML1 is regulated by pH, Ca2+, and phosphoinosi- tides in a combined manner so as to accommodate the dynamic endocytosis process.
基金This work was supported by the Natural Science Basic Research Plan in Shaanxi Province of China[Grant No.2016JQ5046]the National Natural Science Foundation of China[Grant No.51672209]the National Key R&D Program of China[Grant Nos.2017YFB0310300 and 2017YFB0903803].
文摘The structure design,performance analysis,and process optimization of CNT/MOF-derived hierarchical composite play an important role in the development of high-performance microwave absorbing materi-als.Herein,the preparation,morphology evolution,and electromag-netic wave absorption mechanism of CNT/MOF-derived hierarchical composite were systematically investigated.The regulation mechan-ism was revealed by studying the changes in the morphological characteristics,electromagnetic properties,and microwave absorbing performance of CNT/MOF-derived hierarchical composite under differ-ent process parameters.The results show that the morphological characteristics and interface bonding between CNT and MOF have a great impact on the absorptive capacity.The composite with com-position of 0.28Co/0.26Fe has a maximum absorption of−46 dB at 8.6 GHz and a thickness of 4 mm.In addition,the absorption band with reflection loss values of less than−20 dB can be operated with this thickness between 7.15 and 10.18 GHz,showing excellent absorbing ability and electromagnetic wave bandwidth.The regulation mechan-ism of CNT/MOF-derived hierarchical composite mainly depends on the effect of Lorentz force,the ion disorder of CoO-Fe_(2)O_(3) heterojunc-tion,and the spin polarization mechanism of free electrons.This study further improves the corresponding theoretical basis and new design principles,which provides technical support for the development of high-performance absorbing materials.
文摘Class V myosin, one of the most ancient types of myosin, plays a key role in intracellular trafficking. Mammalian cells have three isoforms of myosin V, named Myo5a, Myo5b,
基金Supported by Thousand Talents Program for High-end Innovative Talents of Qinghai Province(2020,2022).
文摘Drought stress is an important factor affecting plant growth and development.It will provide a theoretical basis for cultivating new stress-resistant varieties and improving water utilization rate of plants by studying the regulation mechanism of osmotic adjustment and water transportation under drought stress,and understanding the physiological and biochemical characteristics and stress resistance mechanism.
基金the National Natural Science Foundation of China(Grant No:42177346,52009103,U2243240)Innovation Capability Support Program of Shaanxi(2019TD-040)Observation and Research Station of Groundwater and Ecology in Yulin,Shaanxi,Ministry of Natural Resources。
文摘As vegetation are closely related to soil erosion,hydrodynamic parameter changes under various vegetation pattern conditions can be used as an important basis for the research of the soil erosion mechanism.Through upstream water inflow experiments conducted on a loess hillslope,how the vegetation pattern influences the hydrodynamic processes of sediment transport was analyzed.The results show that the placement of a grass strip on the lower upslope can effectively reduce runoff erosion by 69%,relying on the efficiency of regulated hydrodynamic process.The effective location of grass strip for hillslope alleviating erosion is on the lower part of the upslope,mainly due to the grass strip measure used to regulate the hydrodynamic system.As a result,the underlying surface runoff resistance is increased by 5 times,runoff shear stress is decreased by more than 90%,and runoff power decreased by over 92%.The measure greatly separates the scouring energy of surface runoff that acts on the slope soil.Therefore,the use of grass strips effectively decreases the energy of runoff flowing along the slope,eliminating soil erosion to a great extent and thereby achieving a better regulation of hydrodynamic processe.
基金Funded by the National Natural Science Foundation of China(No.51864012)the Key Projects Supported by Science and Technology in Guizhou Province(No.[2002]KEY020)+2 种基金the Major Special Projects in Guizhou Province(No.[2022]003)the Guizhou Provincial Science Cooperation Program(Nos.[2016]5302,[2017]5788,[2018]5781,[2019]1411,and[2019]2841)the Major Special Projects in Tongren City,Guizhou Province(No.[2021]13)。
文摘The in-situ oxidation of manganese sulfate solution with H2O_(2),sodium hypochlorite,potassium permanganate and oxygen as oxidants was investigated by means of SEM,EDS,XRD,BET and infrared analysis,and the effects of different oxidants on the morphology,phase composition,surface properties and specific surface area of manganese oxides were investigated.The experimental results show that the diameter of manganese oxide particles prepared with H_(2)O_(2)is the smallest,about 50 nm,and the specific surface area is the largest,63.8764 m^(2)/g.It has the advantages of abundant surface hydroxyl groups,no introduction of other impurities and large adsorption potential.It is most suitable to be used as an oxidant for oxidizing manganese sulfate solution to prepare manganese oxide by in-situ oxidation.Nano manganese oxide prepard by H_(2)O_(2)in-situ oxidation method is used as adsorbent to adsorb cobalt and nickel impurities in manganese sulfate.When the reaction pH is 6,the reaction time is 30min and the amount of adsorbent is 1.0 g,the adsorption rates of cobalt and nickel impurities in 100ml manganese sulfate solution are 97.59%and 97.67%,respectively.The residual amounts of cobalt and nickel meet the industrial process standard of first-class products(Co,Ni w/%≤0.005)of high-purity manganese sulfate(Hg/t4823-2015)for batteries.The study plays a guiding role in the preparation and regulation of manganese oxide,and provides a new method with high efficiency,purity and adsorbent availability for the preparation of high-purity manganese sulfate solution.
基金supported by the National Natural Science Foundation of China(31871624)the Agricultural Science and Technology Innovation Program(CAAS-ZDRW202109 and CAAS-ZDRW202002)the Central Public-interest Scientific Institution Basal Research Fund.
文摘Plant AT-rich sequence and zinc binding(PLATZ)transcription factors are a class of plant specific zincdependent DNA-binding proteins that function in abiotic stress response and plant development.In this study,31 GmPLATZ genes were identified in soybean.GmPLATZ17 was down-regulated by drought and exogenous abscisic acid.Transgenic Arabidopsis and soybean hairy roots overexpressing GmPLATZ17 showed drought sensitivity and inhibition of stress-associated gene transcription.In contrast,suppressed expression of GmPLATZ17 led to increased drought tolerance in transgenic soybean hairy roots.The GmPLATZ17 protein was verified to interact physically with the GmDREB5 transcription factor,and overexpression of GmDREB5 increased drought tolerance in soybean hairy roots.Interaction of GmPLATZ17 with GmDREB5 was shown to interfere with the DRE-binding activity of GmDREB5,suppressing downstream stress-associated gene expression.These results show that GmPLATZ17 inhibits drought tolerance by interacting with GmDREB5.This study sheds light on PLATZ transcription factors and the function of GmPLATZ17 in regulating drought sensitivity.
基金financial support from the National Natural Science Foundation of China(Grant No.61971302)。
文摘The blood–brain barrier(BBB)is a structural and functional barrier necessary for brain homeostasis,and it plays an important role in the realization of neural function and in protecting the brain from damage by circulating toxins and pathogens.However,the extremely dense BBB also severely limits the transport of molecules across it,which is a great hindrance to the diagnosis and treatment of central nervous system(CNS)diseases.This paper reports a new method for controllable opening of the BBB,based on the gigahertz acoustic streaming(AS)generated by a bulk acoustic wave resonant device.By adjusting the input power and working distance of the device,AS with tunable flow rate can be generated to disrupt tight junction proteins(TJs)between endothelial cells.The results obtained with this method show that the gigahertz AS promotes the penetration of dextran molecules with different molecular weights across the BBB.This work provides a new platform for studying the mechanical regulation of BBB by fluid shear forces and a new method for improving the efficiency of drug delivery.
基金the Scientific Foundation of the Ministry of Railway,No.6747600045
文摘BACKGROUND:It has been confirmed that c-fos expression increased markedly in hypothalamic paraventricular nucleus(PVN)during asthmatic attack in rats,and PVN has extensive physiological functions,involving in the regulation of respiratory system,etc.OBJECTIVE:To observe the alteration of electroencephalogram(EEG)and power spectra in PVN during the asthmatic attack,and the alteration of lung function and diaphragmatic muscle discharge after bilateral PVN lesion in asthmatic rats.DESIGN:A randomized control study.SETTING:Laboratory of Physiology and Pharmacology,School of Basic Medical Sciences,Southeast University.MATERIALS:Forty-eight male adult SD rats of 260-300 g were used.The rats were randomly divided into 6 groups(n=8):control group,asthma group,electrolytic lesion of PVN group,KA-induced lesion of PVN group,sham electrolytic lesion of PVN group and sham kainic acid(KA)-induced lesion of PVN group.KA,chicken ovalbumin and aluminum hydroxide were purchased from American Sigma Company.Bordetella pertussis vaccine(Institute of Biological Products of Shanghai);stereotaxic apparatus(JiangwanⅡ,China);lesion-producing device(YC-2 programmable stimulato,Chengdu Instrument Company);MD2000 signal processing system(Nanjing Medical School);data acquisition system(RM6240B,Chengdu Instrument Company).METHODs:The experiments were carried out in the Laboratory of Physiology and Pharmacology,School of Basic Medical Sciences,Southeast University from January to August in 2006.①Rats except for control group were sensitized with an intraperitoneal injection of 100 mg chicken ovalbumin and 100 mg aluminum hydroxide and Bordetella pertussis vaccine containing 5×10^(9) heat-killed in 1 mL of sterile saline.From the fifteenth to seventeenth days rats received three times aerosolized ovalbumin challenge.In rats of the control group and asthma group three steel electrodes were placed into the left PVN(AP-1.8 mm,LR 0.4 mm,OH-7.9 mm),parietal cortex and subcutaneous tissue in lower limb.Lung function tests were carried out simultaneously.Small holes were drilled in the skull to introduce a concentric bipolar electrode in the direction of the PVN in order to perform electrolytic lesion.The electrodes were connected to a lesion-producing device and a current of 1.0-1.5 mA was passed over a period of 10-15 s on each side of the PVN.The rats received 0.5μg/0.5μL of KA in phosphate buffer(0.1 mol/L,pH 7.4),and the speed of infusion was 0.1μL per minute in order to perform KA-induced lesion of PVN.②Three days after operation of lesion,lung function tests were carried out.All the electrode and transducer were connected with data acquisition system.This technique yielded airway resistance(Raw),dynamic compliance(Cdyn),the expiratory time(Te)/the inspiratory time(Ti),minute ventilation volume(MVV),EMGdi frequency and EMGdi integral.③The differences of the measurement data were compared using the t test.MAIN OUTCOME MEASURES:①The alteration of EEG and power spectrum of PVN during asthmatic attack in sensitized rats;②The effects of electrolytic lesion or KA-induced lesion of PVN on lung function in asthmatic rats.RESULTS:All the 48 rats were involved in the analysis of results.①Alteration of EEG and power spectrum:Five minutes after injection of ovalbumin into caudal vena,the breathing rate of the rat was obviously speeded up and the total power spectrum was increased[(18476.71±2140.94),(13838.75±2983.26)mV^(2),P<0.01],the percentage of theδpower andθpower decreased significantly(P<0.01),while the percentage ofαpower andβ1 power were enhanced(P<0.05,0.01).Ten minutes after injection,the EEG power spectrum of PVN further shifted rightward,the total power gradually increased(P<0.01)which suggesting that the intensive hypersynchrony activities of PVN neurons.The percentage ofδpower was decreased significantly(P<0.01),but theα,β1 andβ2 were increased(P<0.01).Twenty-five minutes later,the breathing movements became steady,and the EEG power spectrum of PVN returned to the control level step by step.②The alteration of lung function was detected during asthmatic attack after electrolytic lesion or KA-induced lesions of PVN respectively.It was found that EMGdi frequency,Te/Ti and RL were all decreased(P<0.01),EMGdi integral,MVV and Cdyn were all enhanced(P<0.01),while there were no significant changes in the sham surgery group(P>0.05).CONCLUSION:The excitability of PVN is increased during the asthmatic attack.PVN plays a key role in the regulation of asthma.Both electrolytic and KA lesions of PVN can significantly relieve the asthmatic symptoms of rats,and improve their lung function.
文摘The capacity for adult axons to regenerate after injury is diminished compared with developing axons.In the case of central nervous system(CNS)axons,injury causes a total failure to regenerate.This failure is due to both the intrinsic developmental decrease in growth capacity and the extrinsic inhibitory environment formed because of the injury.