We revisit the issue of whether the effective potential for the conformal factor of the metric,which is generated by quantized matter fields,possesses a non-vanishing vacuum expectation value(VEV)or not.We prove that ...We revisit the issue of whether the effective potential for the conformal factor of the metric,which is generated by quantized matter fields,possesses a non-vanishing vacuum expectation value(VEV)or not.We prove that the effective potential has a vanishing vacuum expectation value on the basis of a global GL(4)symmetry.We also account for why there seems to be two different effective potentials for the conformal factor in a theory,one of which gives rise to a vanishing VEV for the conformal factor,whereas the other has a non-vanishing VEV.展开更多
Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency （EPA） and the World Health Org...Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency （EPA） and the World Health Organization （WHO）, air pollution affects millions of people worldwide. Hundreds of thousands of deaths each year and a range of diseases, particularly among vulnerable groups （i.e., children, the elderly, and people with special medical conditions）, are attributed to air pollution. These effects are not always caused by single pollutant in the air; rather, they are considered consequences of the multi-pollutants to which people are simultaneously exposed.展开更多
Based on the Huybrechts' linear-combination operator,effects of thermal lattice vibration on the effective potential of weak-coupling bipolaron in semiconductor quantum dots are studied by using the LLP variationa...Based on the Huybrechts' linear-combination operator,effects of thermal lattice vibration on the effective potential of weak-coupling bipolaron in semiconductor quantum dots are studied by using the LLP variational method and quantum statistical theory.The results show that the absolute value of the induced potential of the bipolaron increases with increasing the electron-phonon coupling strength,but decreases with increasing the temperature and the distance of electrons,respectively;the absolute value of the effective potential increases with increasing the radius of the quantum dot,electron-phonon coupling strength and the distance of electrons,respectively,but decreases with increasing the temperature;the temperature and electron-phonon interaction have the important influence on the formation and state properties of the bipolaron:the bipolarons in the bound state are closer and more stable when the electron-phonon coupling strength is larger or the temperature is lower;the confinement potential and coulomb repulsive potential between electrons are unfavorable to the formation of bipolarons in the bound state.展开更多
Multiple sclerosis（MS）is a chronic autoimmune disease of the central nervous system（CNS）characterized by coexisting processes of inflammation,demyelination,axonal neurodegeneration,and gliosis.It is the most commo...Multiple sclerosis（MS）is a chronic autoimmune disease of the central nervous system（CNS）characterized by coexisting processes of inflammation,demyelination,axonal neurodegeneration,and gliosis.It is the most common disabling neurological disease in young adulthood.展开更多
[Objective] The aim was to study the dynamic variation characteristics of phosphorus in paddy field runoff in saline land and its potential environmental effect. [Method] Taking Qianguo irrigation district in soda-sal...[Objective] The aim was to study the dynamic variation characteristics of phosphorus in paddy field runoff in saline land and its potential environmental effect. [Method] Taking Qianguo irrigation district in soda-saline land in Songnen Plain as study object, the dynamic variation law of phosphorus in paddy field runoff under different irrigation conditions and its potential environmental effect were discussed. [Result] Surface water in paddy field was alkaline, and scattered soil had poor fertilizer conservation capacity. Phosphorus accumulated in soil surface, which could increase the risk of phosphorus loss. Phosphorus loss in paddy field mainly occurred in irrigation period and runoff period caused by rainstorm. The concentration of total phosphorus (TP), particulate phosphorus (PP), total dissolved phosphorus (TDP) and dissolved reactive phosphorus (DRP) in paddy field runoff decreased with time, especially PP. Phosphorus concentration exceeded critical value and resulted to eutrophication, which threatened the water quality security of Chagan Lake. Phosphorus concentration in water recession canal increased with time, and eutrophication with different degrees appeared under high temperature. TP concentration in surface water of paddy field was highly negatively correlated with that in water recession canal, and the correlation coefficients R2(α=0.05)in three paddy fields were 0.850 9, 0.896 4 and 0.915 3, respectively. The pollution load of phosphorus in paddy field with the best irrigation condition was higher, and its pollution risk was the highest. Thus, such fields should be monitored and controlled mainly as the critical source area of phosphorus loss. [Conclusion] The study could provide theoretical foundations for developing saline land rationally, establishing optimal management measure of phosphorus in saline land and controlling phosphorus loss from farmland to protect local water resources.展开更多
BACKGROUND： Phycocyanin can relieve decrease of mitochondrial membrane potential through reducing production of active oxygen so as to protect neurons after hypoxia/reoxygenation. OBJECTIVE： To observe the effect of...BACKGROUND： Phycocyanin can relieve decrease of mitochondrial membrane potential through reducing production of active oxygen so as to protect neurons after hypoxia/reoxygenation. OBJECTIVE： To observe the effect of phycocyanin on activity of PC12 cells and mitochondrial membrane potential after hypoxia/reoxygenation. DESIGN： Randomized controlled study SETTING ： Cerebrovascular Disease Institute of Affiliated Hospital, Medical College of Qingdao University MATERIALS： The experiment was carried out at the Key Laboratory of Prevention and Cure for cerebropathia in Shandong Province from October to December 2005. PC12 cells, rat chromaffin tumor cells, were provided by Storage Center of Wuhan University; phycocyanin was provided by Ocean Institute of Academia Sinica; Thiazoyl blue tetrazolium bromide （MTT） and rhodamine 123 were purchased from Sigma Company, USA; RPMI-1640 medium, fetal bovine serum and equine serum were purchased from Gibco Company, USA. METHODS： ① Culture of PC12 cells： PC12 cells were put into RPMI-1640 medium which contained 100 g/L heat inactivation equine serum and 0.05 volume fraction of fetal bovine serum and incubated in CO2 incubator at 37℃. Number of cells was regulated to 4 × 10^5 L 1, and cells were inoculated at 96-well culture plate. The final volume was 100μL. ② Model establishing and grouping： Cultured PC12 cells were randomly divided into three groups： phycocyanin group, model control group and non-hypoxia group. At 24 hours before hypoxia, culture solution in phycocyanin group was added with phycocyanin so as to make sure the final concentration of 3 g/L , but cells in model control group did not add with phycocyanin. Cells in non-hypoxia group were also randomly divided into adding phycocyanin group （the final concentration of 3 g/L） and non-adding phycocyanin group. Cells in model control group and phycocyanin group were cultured with hypoxia for 1 hour and reoxygenation for 1, 2 and 3 hours; meanwhile, cells in non-hypoxia group were cultured with oxygen and were measured at 1 hour after hypoxia/reoxygenation. ③ Detecting items： At 1, 2 and 3 hours after reoxygenation, absorbance （A value） of PC12 cells was measured with MTT technique so as to observe activity and quantity of cells. Fluorescence intensity of PC12 cells marked by rhodamine 123 was measured with confocal microscope in order to observe changes of mitochondrial membrane potential. MAEN OUTCOME MEASURES： Comparisons between quantity and activity of PC12 cells and mitochondria membrane potential at 1, 2 and 3 hours after reoxygenation. RESULTS： ① Effect of phycocyanin on quantity and activity of PC12 cells： A value was 0.924±0.027 in adding phycocyanin group and 0.924±0.033 in non-adding phycocyanin group. A value was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after reoxygenation （0.817±0.053, 0.838±0.037, 0.875±0.029; 0.842±0.029, 0.872±0.025, 0.906±0.023, P 〈 0.05）. A value was higher in phycocyanin group than that in model control group at 1, 2 and 3 after culture （P 〈 0.05）. With culture time being longer, A value was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. ~ Effect of phycocyanin on mitochondrial membrane potential of PC12 cells： Fluorescence intensity was 2.967±0.253 in adding phycocyanin group and 2.962±0.294 in non-adding phycocyanin group. Fluorescence intensity was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after hypoxia/reoxygenation （1.899±0.397, 2.119±0.414, 2.287±0.402; 2.191±0.377, 2.264±0.359, 2.436±0.471, P 〈 0.05）; but it was higher in phycocyanin group than that in model control group at 1, 2 and 3 after reoxygenation （P 〈 0.05）. With culture time being longer, fluorescence intensity was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. CONCLUSION： Phycocyanin and reoxygenation can protect PC12 cells after hypoxia injury through increasing mitochondrial membrane potential and cellular activity, and the effect is improved gradually with prolonging time of reoxygenation.展开更多
We calculate for the first time the static properties of the deuteron, within the framework of supersymmetric quantum mechanics, analytically. A new effective potential and its partner are derived from a superpotentia...We calculate for the first time the static properties of the deuteron, within the framework of supersymmetric quantum mechanics, analytically. A new effective potential and its partner are derived from a superpotential so that all parameters are fitted by the experimental data. An analytical expression is obtained for the deuteron wave function and contributions of the orthogonal ^(13)S_(1) and ^(13)D_(1) states are determined, explicitly. Compared to one pion exchange, the superpotential produces an electrostatic as well as two pion exchange terms for the potential. The saddle point radius of the potential and the maximum of the wave function are linearly proportional. In comparison with other methods, the approach presented in this paper is a new and extensible symmetry-based approach that, despite its straightforward calculations and explicit analytical expressions, provides a good explanation for two-body effective interactions such as two-nucleon systems and diatomic molecules.展开更多
We have proven the general relations between the gap equations obeyed by dynamical fermion mass and thecorresponding effective potentials at finite temperature and chemical potential in D-dimensional four-fermion inte...We have proven the general relations between the gap equations obeyed by dynamical fermion mass and thecorresponding effective potentials at finite temperature and chemical potential in D-dimensional four-fermion interactionmodels. This gives an easy approach to get effective potentials directly from the gap equations. We find out explicitexpressions for the effective potentials at zero temperature in the cases of D = 2,3, and 4 for practical use.展开更多
We study force generation and motion of molecular motors using a simple two-state model in the paper.Asymmetric and periodic potential is adopted to describe the interaction between motor proteins and filaments that a...We study force generation and motion of molecular motors using a simple two-state model in the paper.Asymmetric and periodic potential is adopted to describe the interaction between motor proteins and filaments that are periodic and polar. The current and the slope of the effective potential as functions of the temperature and transition rates are calculated in the two-state model. The ratio of the slope of the effective potential to the current is also calculated. It is shown that the directed motion of motor proteins is relevant to the effective potential. The slope of the effective potential corresponds to an average force. The non-vanishing force therefore implies that detailed balance is broken in the process of transition between different states.展开更多
In the framework of the functional integral formalism, we calculate the effective potential of the double sine-Gordon (DsG) model up to the second order with an optimized expansion and the Coleman's normal-orderin...In the framework of the functional integral formalism, we calculate the effective potential of the double sine-Gordon (DsG) model up to the second order with an optimized expansion and the Coleman's normal-ordering prescription. Within the range of convergence, we make a comparison among the classicaland the effective potential of the first and second order. The numerical analysis shows that the DsG post-Gaussian EP possesses some fine global properties and makes a substantial and a concordant quantum correction to the features of the classical potential.展开更多
We complete the derivation of the Cornwall-Jackiw-Tomboulis effective potentiM for quark propagator at finite temperature and finite quark chemical potential in the real-time formalism of thermal field theory and in L...We complete the derivation of the Cornwall-Jackiw-Tomboulis effective potentiM for quark propagator at finite temperature and finite quark chemical potential in the real-time formalism of thermal field theory and in Landau gauge. In the approximation that the function A（p^2） in inverse quark propagator is replaced by unity, by means of the running gauge coupling and the quark mass function invariant under the renormalization group in zero temperature Quantum Chromadynamics （QCD）, we obtain a calculable expression for the thermal effective potential, which will be a useful means to research chiral phase transition in QCD in the real-time formalism.展开更多
Dear Editor,The prevalence of drug abuse has diverted from traditional drugs such as opioid and cannabis to modern,synthetic and psychoactive drugs such as amphetamine groups,the amphetamine(AT)and methamphetamine[1]....Dear Editor,The prevalence of drug abuse has diverted from traditional drugs such as opioid and cannabis to modern,synthetic and psychoactive drugs such as amphetamine groups,the amphetamine(AT)and methamphetamine[1].Amphetamine is used medically to treat several disorders such as attention deficit hyperactivity disorder,narcolepsy,depression and minor obesity[2].However,AT has also gained展开更多
BACKGROUND： Somatosensory evoked potential （SEP） has become a method with higher sensitivity and specificity than electroencephalogram in detecting the brain function and the region, range and degree of ischemia. H...BACKGROUND： Somatosensory evoked potential （SEP） has become a method with higher sensitivity and specificity than electroencephalogram in detecting the brain function and the region, range and degree of ischemia. However, the effects of ligustrazine on SEP is still not clear. OBJECTIVE ： To study the protective effects of ligustrazini injection on cerebral ischemia-reperfusion injury.DESIGN： Auto-control study, random grouping.SETTING： Qilu Hospital of Shandong University.MATERIALS： The experiment was completed in the Cerebral Functional Room of Qilu Hospital Affiliated to Shandong University from March 2002 to June 2004. A totally of 24 healthy Harbin rabbits were randomly divided into blank control group （n=8）, model control group （n=8） and ligustrazine treatment group （n=8）. Hydrochloric ligustrazine injection, 40 mg/2 mL each ampoule, was provided by the Third Pharmaceutical Factory of Beijing （certification： 93035236273）. The main component was hydrochloric ligustrazine and the chemical name was 2, 3, 5, 6-tetramethyl pyrazine hydrochloride. METHODS：① Modeling method： The bilateral common carotid artery ligation was adopted to make the model. ② Index of cerebral functional lesion evaluated with SEP during ischemia-reperfusion： DISA 2000C neuromyoeletrometer provided by Dantec Electronics Ltd, Denmark was used to detect SEP. ③ Interventional process： Blank control group： The latencies and amplitudes of SEP were measured before injection with 1.5 mg/kg ligustrazine and at the points of 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after injection. Ligustrazine treatment group： Rabbits were injected with 1.5 mg/kg ligustrazine, and those of model control group were injected the same volume of saline. Thirty minutes later, the bilateral common carotid artery of the rabbits all had been ligated for 30 minutes, and then reperfused for 120 minutes. The latencies and amplitudes of SEP were measured before injection, before ligation, at the points of 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes after ligation, and at the points of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after reperfusion.④ Evaluating criteria： Normal values of P-wave latencies and amplitudes were （19.34±3.18） ms and （4.55±1.43）μV. Average value before injection in blank control group and average values before injection, after injection and before ligation in ischemiareperfusion group were regarded as control criteria to evaluate changes of P-wave latencies and amplitudes after experiment. MAIN OUTCOME MEASURES： P-wave latencies and amplitudes of SEP in the three groups.RESULTS ： A total of 24 rabbits were involved in the final analysis without any loss.① Blank control group： The P-wave latencies delayed markedly at each time point after injection. Compared with that before injection, there was a significant difference （P 〈 0.05-0.01）. The P-wave amplitudes did not fluctuate noticeably all the time after injection, but significantly decreased when compared with those before injection （P 〈 0.05-0.01）. ② Ischemia-reperfusion group： The P-wave latencies delayed and amplitudes decreased in the rabbits with cerebral ischemia-reperfusion at all points of time during cerebral ischemia-reperfusion, and there was significant difference when compared with the levels before ischemia （P 〈 0.05）. When ligustrazine was injected, the latencies and amplitudes changed less, and as compared with the levels before ischemia, the difference was not significant （P〉 0.05）.CONCLUSION：① Ligustrazine can inhibit P-wave latencies and amplitudes of SEP of normal rabbits.②Ligustrazine can improve P-wave latencies and amplitudes of SEP of rabbits with cerebral ischemia-reperfusion injury.展开更多
We investigate the many-body wave function of a quantum system with time-dependent effective mass, confined by a harmonic potential with time-dependent frequency, and perturbed by a time-dependent spatially homogeneou...We investigate the many-body wave function of a quantum system with time-dependent effective mass, confined by a harmonic potential with time-dependent frequency, and perturbed by a time-dependent spatially homogeneous electric field. It is found that the wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schr6dinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the harmonic potential theorem wave function when both the effective mass and frequency are static. An example of application is also given.展开更多
Rho-associated kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase RhoA. The Rho/ROCK pathway is closely related to the pathogenesis of several central nervous syst...Rho-associated kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase RhoA. The Rho/ROCK pathway is closely related to the pathogenesis of several central nervous system (CNS) disorders, and involved in many aspects of neuronal functions including neurite outgrowth and retraction. In the adult CNS, the damaged neuron regeneration is very difficult due to the presence of myelin-associated axon growth inhibitors such as Nogo, myelin-associated glycoprotein (MAG) and oligodendrocyte-myelin glycoprotein (Omgp), etc. The effects of these axon growth inhibitors are reversed by blocking the Rho/ROCK pathway 47 vitro, and the inhibition of Rho/ROCK pathway can promote axon regeneration and functional recovery in the injured CNS in viva In addition, the therapeutic effects of the Rho/ROCK inhibitors have also been demonstrated in some animal models and the Rho/ROCK pathway becomes an attractive target for the development of drugs for treating CNS disorders. In this review, we summarized on the effect of the Rho and the downstream factor ROCK in neural regeneration, and the potential therapeutic effect of Rho/ROCK inhibitors in the survival and axonal regeneration of retinal ganglion cell was also discussed.展开更多
In order to elucidate the unusual chemical sensitivity of binary indium bromides. thepotential energy surface of the model complex InBr87- has been studied by means of ah initio all-electron calculation with larger ba...In order to elucidate the unusual chemical sensitivity of binary indium bromides. thepotential energy surface of the model complex InBr87- has been studied by means of ah initio all-electron calculation with larger basis sets. The configuration is on a local maximum of the energysurface and crystal potential around In+ is soft, allowing small spontaneous distortions as a result ofa second-order Jahn-Teller instability.展开更多
A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry（IMS） techniques is reported.The strategy divides the whole datacube of the sample into several subs...A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry（IMS） techniques is reported.The strategy divides the whole datacube of the sample into several subsets and analyses them one by one to obtain the results.Instead of analyzing the whole datacube at one time,the strategy makes the analysis easier and decreases the computation time greatly.In this report,the IMS data are produced by the air flow-assisted ionization IMS（AFAI-IMS）.The strategy can be used in combination with most multivariate statistical analysis methods.In this paper,the strategy was combined with the principal component analysis（PCA） and partial least square analysis（PLS）.It was proven to be effective by analyzing the handwriting sample.By using the strategy,the m/z corresponding to the specific lipids in rat brain tissue were distinguished successfully.Moreover the analysis time grew linearly instead of exponentially as the size of sample increased.The strategy developed in this study has enormous potential for searching for the mjz of potential biomarkers quickly and effectively.展开更多
A new 'twice loose shoe' method in the Wheeler–DeWitt equation of the universe wavefunction on the cosmic scale factor and a scalar field is suggested. We analyze both the affections coming from the tunnell...A new 'twice loose shoe' method in the Wheeler–DeWitt equation of the universe wavefunction on the cosmic scale factor and a scalar field is suggested. We analyze both the affections coming from the tunnelling effect of and the potential well effect of , and obtain the initial values and about a primary closed universe which is born with the largest probability in the quantum manner. Our result is able to overcome the 'large field difficulty' of the universe quantum creation probability with only tunnelling effect. This new born universe has to suffer a startup of inflation, and then comes into the usual slow rolling inflation. The universe with the largest probability maybe has a 'gentle' inflation or an eternal chaotic inflation, this depends on a new parameter which describes the tunnelling character.展开更多
We discuss the escape problem with the consideration of both the activity of particles and the roughness of potentials.We derive analytic expressions for the escape rate of an active Brownian particle in two types of ...We discuss the escape problem with the consideration of both the activity of particles and the roughness of potentials.We derive analytic expressions for the escape rate of an active Brownian particle in two types of rough potentials by employing the effective equilibrium approach and the Zwanzig method.We find that activity enhances the escape rate,but both the oscillating perturbation and the random amplitude hinder escaping.展开更多
基金supported in part by the JSPS Kakenhi under Grant No.21K03539。
文摘We revisit the issue of whether the effective potential for the conformal factor of the metric,which is generated by quantized matter fields,possesses a non-vanishing vacuum expectation value(VEV)or not.We prove that the effective potential has a vanishing vacuum expectation value on the basis of a global GL(4)symmetry.We also account for why there seems to be two different effective potentials for the conformal factor in a theory,one of which gives rise to a vanishing VEV for the conformal factor,whereas the other has a non-vanishing VEV.
文摘Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency （EPA） and the World Health Organization （WHO）, air pollution affects millions of people worldwide. Hundreds of thousands of deaths each year and a range of diseases, particularly among vulnerable groups （i.e., children, the elderly, and people with special medical conditions）, are attributed to air pollution. These effects are not always caused by single pollutant in the air; rather, they are considered consequences of the multi-pollutants to which people are simultaneously exposed.
基金Supported by the Items of Institution of Higher Education Scientific Research of Inner Mongolia under Grant No. NJ101116
文摘Based on the Huybrechts' linear-combination operator,effects of thermal lattice vibration on the effective potential of weak-coupling bipolaron in semiconductor quantum dots are studied by using the LLP variational method and quantum statistical theory.The results show that the absolute value of the induced potential of the bipolaron increases with increasing the electron-phonon coupling strength,but decreases with increasing the temperature and the distance of electrons,respectively;the absolute value of the effective potential increases with increasing the radius of the quantum dot,electron-phonon coupling strength and the distance of electrons,respectively,but decreases with increasing the temperature;the temperature and electron-phonon interaction have the important influence on the formation and state properties of the bipolaron:the bipolarons in the bound state are closer and more stable when the electron-phonon coupling strength is larger or the temperature is lower;the confinement potential and coulomb repulsive potential between electrons are unfavorable to the formation of bipolarons in the bound state.
基金Dr.Mao-Draayer has served as a consultant and/or received grant support from:Acorda,Bayer Pharmaceutical,Biogen Idec,EMD Serono,Genzyme,Novartis,Questor,Teva Neuroscience and Chugai PharmaDr.Mao-Draayeris currently supported by grants from NIH NIAID Autoimmune Center of Excellence:UM1-AI110557+1 种基金NIH NINDS R01-NS080821the University of Michigan Neurology Department
文摘Multiple sclerosis（MS）is a chronic autoimmune disease of the central nervous system（CNS）characterized by coexisting processes of inflammation,demyelination,axonal neurodegeneration,and gliosis.It is the most common disabling neurological disease in young adulthood.
基金Supported by National Water Pollution Control and Management Science & Technology Specific Projects of China(2008ZX07207-006-04)Innovation Foundation Projects for Doctoral Students of Donghua University in 2011(11D11311)
文摘[Objective] The aim was to study the dynamic variation characteristics of phosphorus in paddy field runoff in saline land and its potential environmental effect. [Method] Taking Qianguo irrigation district in soda-saline land in Songnen Plain as study object, the dynamic variation law of phosphorus in paddy field runoff under different irrigation conditions and its potential environmental effect were discussed. [Result] Surface water in paddy field was alkaline, and scattered soil had poor fertilizer conservation capacity. Phosphorus accumulated in soil surface, which could increase the risk of phosphorus loss. Phosphorus loss in paddy field mainly occurred in irrigation period and runoff period caused by rainstorm. The concentration of total phosphorus (TP), particulate phosphorus (PP), total dissolved phosphorus (TDP) and dissolved reactive phosphorus (DRP) in paddy field runoff decreased with time, especially PP. Phosphorus concentration exceeded critical value and resulted to eutrophication, which threatened the water quality security of Chagan Lake. Phosphorus concentration in water recession canal increased with time, and eutrophication with different degrees appeared under high temperature. TP concentration in surface water of paddy field was highly negatively correlated with that in water recession canal, and the correlation coefficients R2(α=0.05)in three paddy fields were 0.850 9, 0.896 4 and 0.915 3, respectively. The pollution load of phosphorus in paddy field with the best irrigation condition was higher, and its pollution risk was the highest. Thus, such fields should be monitored and controlled mainly as the critical source area of phosphorus loss. [Conclusion] The study could provide theoretical foundations for developing saline land rationally, establishing optimal management measure of phosphorus in saline land and controlling phosphorus loss from farmland to protect local water resources.
基金the Natural Science Foundation of Shandong Province, No. Y2004C04
文摘BACKGROUND： Phycocyanin can relieve decrease of mitochondrial membrane potential through reducing production of active oxygen so as to protect neurons after hypoxia/reoxygenation. OBJECTIVE： To observe the effect of phycocyanin on activity of PC12 cells and mitochondrial membrane potential after hypoxia/reoxygenation. DESIGN： Randomized controlled study SETTING ： Cerebrovascular Disease Institute of Affiliated Hospital, Medical College of Qingdao University MATERIALS： The experiment was carried out at the Key Laboratory of Prevention and Cure for cerebropathia in Shandong Province from October to December 2005. PC12 cells, rat chromaffin tumor cells, were provided by Storage Center of Wuhan University; phycocyanin was provided by Ocean Institute of Academia Sinica; Thiazoyl blue tetrazolium bromide （MTT） and rhodamine 123 were purchased from Sigma Company, USA; RPMI-1640 medium, fetal bovine serum and equine serum were purchased from Gibco Company, USA. METHODS： ① Culture of PC12 cells： PC12 cells were put into RPMI-1640 medium which contained 100 g/L heat inactivation equine serum and 0.05 volume fraction of fetal bovine serum and incubated in CO2 incubator at 37℃. Number of cells was regulated to 4 × 10^5 L 1, and cells were inoculated at 96-well culture plate. The final volume was 100μL. ② Model establishing and grouping： Cultured PC12 cells were randomly divided into three groups： phycocyanin group, model control group and non-hypoxia group. At 24 hours before hypoxia, culture solution in phycocyanin group was added with phycocyanin so as to make sure the final concentration of 3 g/L , but cells in model control group did not add with phycocyanin. Cells in non-hypoxia group were also randomly divided into adding phycocyanin group （the final concentration of 3 g/L） and non-adding phycocyanin group. Cells in model control group and phycocyanin group were cultured with hypoxia for 1 hour and reoxygenation for 1, 2 and 3 hours; meanwhile, cells in non-hypoxia group were cultured with oxygen and were measured at 1 hour after hypoxia/reoxygenation. ③ Detecting items： At 1, 2 and 3 hours after reoxygenation, absorbance （A value） of PC12 cells was measured with MTT technique so as to observe activity and quantity of cells. Fluorescence intensity of PC12 cells marked by rhodamine 123 was measured with confocal microscope in order to observe changes of mitochondrial membrane potential. MAEN OUTCOME MEASURES： Comparisons between quantity and activity of PC12 cells and mitochondria membrane potential at 1, 2 and 3 hours after reoxygenation. RESULTS： ① Effect of phycocyanin on quantity and activity of PC12 cells： A value was 0.924±0.027 in adding phycocyanin group and 0.924±0.033 in non-adding phycocyanin group. A value was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after reoxygenation （0.817±0.053, 0.838±0.037, 0.875±0.029; 0.842±0.029, 0.872±0.025, 0.906±0.023, P 〈 0.05）. A value was higher in phycocyanin group than that in model control group at 1, 2 and 3 after culture （P 〈 0.05）. With culture time being longer, A value was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. ~ Effect of phycocyanin on mitochondrial membrane potential of PC12 cells： Fluorescence intensity was 2.967±0.253 in adding phycocyanin group and 2.962±0.294 in non-adding phycocyanin group. Fluorescence intensity was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after hypoxia/reoxygenation （1.899±0.397, 2.119±0.414, 2.287±0.402; 2.191±0.377, 2.264±0.359, 2.436±0.471, P 〈 0.05）; but it was higher in phycocyanin group than that in model control group at 1, 2 and 3 after reoxygenation （P 〈 0.05）. With culture time being longer, fluorescence intensity was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. CONCLUSION： Phycocyanin and reoxygenation can protect PC12 cells after hypoxia injury through increasing mitochondrial membrane potential and cellular activity, and the effect is improved gradually with prolonging time of reoxygenation.
基金the financial support from Golestan University and Istanbul University。
文摘We calculate for the first time the static properties of the deuteron, within the framework of supersymmetric quantum mechanics, analytically. A new effective potential and its partner are derived from a superpotential so that all parameters are fitted by the experimental data. An analytical expression is obtained for the deuteron wave function and contributions of the orthogonal ^(13)S_(1) and ^(13)D_(1) states are determined, explicitly. Compared to one pion exchange, the superpotential produces an electrostatic as well as two pion exchange terms for the potential. The saddle point radius of the potential and the maximum of the wave function are linearly proportional. In comparison with other methods, the approach presented in this paper is a new and extensible symmetry-based approach that, despite its straightforward calculations and explicit analytical expressions, provides a good explanation for two-body effective interactions such as two-nucleon systems and diatomic molecules.
文摘We have proven the general relations between the gap equations obeyed by dynamical fermion mass and thecorresponding effective potentials at finite temperature and chemical potential in D-dimensional four-fermion interactionmodels. This gives an easy approach to get effective potentials directly from the gap equations. We find out explicitexpressions for the effective potentials at zero temperature in the cases of D = 2,3, and 4 for practical use.
文摘We study force generation and motion of molecular motors using a simple two-state model in the paper.Asymmetric and periodic potential is adopted to describe the interaction between motor proteins and filaments that are periodic and polar. The current and the slope of the effective potential as functions of the temperature and transition rates are calculated in the two-state model. The ratio of the slope of the effective potential to the current is also calculated. It is shown that the directed motion of motor proteins is relevant to the effective potential. The slope of the effective potential corresponds to an average force. The non-vanishing force therefore implies that detailed balance is broken in the process of transition between different states.
文摘In the framework of the functional integral formalism, we calculate the effective potential of the double sine-Gordon (DsG) model up to the second order with an optimized expansion and the Coleman's normal-ordering prescription. Within the range of convergence, we make a comparison among the classicaland the effective potential of the first and second order. The numerical analysis shows that the DsG post-Gaussian EP possesses some fine global properties and makes a substantial and a concordant quantum correction to the features of the classical potential.
文摘We complete the derivation of the Cornwall-Jackiw-Tomboulis effective potentiM for quark propagator at finite temperature and finite quark chemical potential in the real-time formalism of thermal field theory and in Landau gauge. In the approximation that the function A（p^2） in inverse quark propagator is replaced by unity, by means of the running gauge coupling and the quark mass function invariant under the renormalization group in zero temperature Quantum Chromadynamics （QCD）, we obtain a calculable expression for the thermal effective potential, which will be a useful means to research chiral phase transition in QCD in the real-time formalism.
基金supported by Uni SZA/NRGS/2013(RR057-1)grant from Malaysia Ministry of Higher Education
文摘Dear Editor,The prevalence of drug abuse has diverted from traditional drugs such as opioid and cannabis to modern,synthetic and psychoactive drugs such as amphetamine groups,the amphetamine(AT)and methamphetamine[1].Amphetamine is used medically to treat several disorders such as attention deficit hyperactivity disorder,narcolepsy,depression and minor obesity[2].However,AT has also gained
基金Technological Developing Plan of Science and Technology Bureau of Shandong Province, No. 032050116
文摘BACKGROUND： Somatosensory evoked potential （SEP） has become a method with higher sensitivity and specificity than electroencephalogram in detecting the brain function and the region, range and degree of ischemia. However, the effects of ligustrazine on SEP is still not clear. OBJECTIVE ： To study the protective effects of ligustrazini injection on cerebral ischemia-reperfusion injury.DESIGN： Auto-control study, random grouping.SETTING： Qilu Hospital of Shandong University.MATERIALS： The experiment was completed in the Cerebral Functional Room of Qilu Hospital Affiliated to Shandong University from March 2002 to June 2004. A totally of 24 healthy Harbin rabbits were randomly divided into blank control group （n=8）, model control group （n=8） and ligustrazine treatment group （n=8）. Hydrochloric ligustrazine injection, 40 mg/2 mL each ampoule, was provided by the Third Pharmaceutical Factory of Beijing （certification： 93035236273）. The main component was hydrochloric ligustrazine and the chemical name was 2, 3, 5, 6-tetramethyl pyrazine hydrochloride. METHODS：① Modeling method： The bilateral common carotid artery ligation was adopted to make the model. ② Index of cerebral functional lesion evaluated with SEP during ischemia-reperfusion： DISA 2000C neuromyoeletrometer provided by Dantec Electronics Ltd, Denmark was used to detect SEP. ③ Interventional process： Blank control group： The latencies and amplitudes of SEP were measured before injection with 1.5 mg/kg ligustrazine and at the points of 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after injection. Ligustrazine treatment group： Rabbits were injected with 1.5 mg/kg ligustrazine, and those of model control group were injected the same volume of saline. Thirty minutes later, the bilateral common carotid artery of the rabbits all had been ligated for 30 minutes, and then reperfused for 120 minutes. The latencies and amplitudes of SEP were measured before injection, before ligation, at the points of 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes after ligation, and at the points of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after reperfusion.④ Evaluating criteria： Normal values of P-wave latencies and amplitudes were （19.34±3.18） ms and （4.55±1.43）μV. Average value before injection in blank control group and average values before injection, after injection and before ligation in ischemiareperfusion group were regarded as control criteria to evaluate changes of P-wave latencies and amplitudes after experiment. MAIN OUTCOME MEASURES： P-wave latencies and amplitudes of SEP in the three groups.RESULTS ： A total of 24 rabbits were involved in the final analysis without any loss.① Blank control group： The P-wave latencies delayed markedly at each time point after injection. Compared with that before injection, there was a significant difference （P 〈 0.05-0.01）. The P-wave amplitudes did not fluctuate noticeably all the time after injection, but significantly decreased when compared with those before injection （P 〈 0.05-0.01）. ② Ischemia-reperfusion group： The P-wave latencies delayed and amplitudes decreased in the rabbits with cerebral ischemia-reperfusion at all points of time during cerebral ischemia-reperfusion, and there was significant difference when compared with the levels before ischemia （P 〈 0.05）. When ligustrazine was injected, the latencies and amplitudes changed less, and as compared with the levels before ischemia, the difference was not significant （P〉 0.05）.CONCLUSION：① Ligustrazine can inhibit P-wave latencies and amplitudes of SEP of normal rabbits.②Ligustrazine can improve P-wave latencies and amplitudes of SEP of rabbits with cerebral ischemia-reperfusion injury.
基金Supported by the National Natural Science Foundation of China under Grant No 11275100the K.C.Wong Magna Foundation of Ningbo University
文摘We investigate the many-body wave function of a quantum system with time-dependent effective mass, confined by a harmonic potential with time-dependent frequency, and perturbed by a time-dependent spatially homogeneous electric field. It is found that the wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schr6dinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the harmonic potential theorem wave function when both the effective mass and frequency are static. An example of application is also given.
基金Supported by National Nature Science Foundation of China (No.81070728)Shanghai "Science and Technology Innovation Action Plan" Basic Research Key Project,China (No.11JC1407700 and 11 JC1407701)+1 种基金Shanghai Nature Science Foundation, China (No.08ZR1413900)Shanghai Leading Academic Discipline Project, China(No.S30205)
文摘Rho-associated kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase RhoA. The Rho/ROCK pathway is closely related to the pathogenesis of several central nervous system (CNS) disorders, and involved in many aspects of neuronal functions including neurite outgrowth and retraction. In the adult CNS, the damaged neuron regeneration is very difficult due to the presence of myelin-associated axon growth inhibitors such as Nogo, myelin-associated glycoprotein (MAG) and oligodendrocyte-myelin glycoprotein (Omgp), etc. The effects of these axon growth inhibitors are reversed by blocking the Rho/ROCK pathway 47 vitro, and the inhibition of Rho/ROCK pathway can promote axon regeneration and functional recovery in the injured CNS in viva In addition, the therapeutic effects of the Rho/ROCK inhibitors have also been demonstrated in some animal models and the Rho/ROCK pathway becomes an attractive target for the development of drugs for treating CNS disorders. In this review, we summarized on the effect of the Rho and the downstream factor ROCK in neural regeneration, and the potential therapeutic effect of Rho/ROCK inhibitors in the survival and axonal regeneration of retinal ganglion cell was also discussed.
文摘In order to elucidate the unusual chemical sensitivity of binary indium bromides. thepotential energy surface of the model complex InBr87- has been studied by means of ah initio all-electron calculation with larger basis sets. The configuration is on a local maximum of the energysurface and crystal potential around In+ is soft, allowing small spontaneous distortions as a result ofa second-order Jahn-Teller instability.
基金supported by the National Instrumentation Programmme(Nos.2011YQ17006702 and 2011YQ14015010)the National Natural Science Foundation of China(Nos.81102413 and 21175121)Fundamental Research Program of Shenzhen (No.JC201005280634A).
文摘A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry（IMS） techniques is reported.The strategy divides the whole datacube of the sample into several subsets and analyses them one by one to obtain the results.Instead of analyzing the whole datacube at one time,the strategy makes the analysis easier and decreases the computation time greatly.In this report,the IMS data are produced by the air flow-assisted ionization IMS（AFAI-IMS）.The strategy can be used in combination with most multivariate statistical analysis methods.In this paper,the strategy was combined with the principal component analysis（PCA） and partial least square analysis（PLS）.It was proven to be effective by analyzing the handwriting sample.By using the strategy,the m/z corresponding to the specific lipids in rat brain tissue were distinguished successfully.Moreover the analysis time grew linearly instead of exponentially as the size of sample increased.The strategy developed in this study has enormous potential for searching for the mjz of potential biomarkers quickly and effectively.
文摘A new 'twice loose shoe' method in the Wheeler–DeWitt equation of the universe wavefunction on the cosmic scale factor and a scalar field is suggested. We analyze both the affections coming from the tunnelling effect of and the potential well effect of , and obtain the initial values and about a primary closed universe which is born with the largest probability in the quantum manner. Our result is able to overcome the 'large field difficulty' of the universe quantum creation probability with only tunnelling effect. This new born universe has to suffer a startup of inflation, and then comes into the usual slow rolling inflation. The universe with the largest probability maybe has a 'gentle' inflation or an eternal chaotic inflation, this depends on a new parameter which describes the tunnelling character.
基金the National Natural Science Foundation of China(Grant No.11975050 and No.11735005)
文摘We discuss the escape problem with the consideration of both the activity of particles and the roughness of potentials.We derive analytic expressions for the escape rate of an active Brownian particle in two types of rough potentials by employing the effective equilibrium approach and the Zwanzig method.We find that activity enhances the escape rate,but both the oscillating perturbation and the random amplitude hinder escaping.
