Experiments were conducted in an indoor soil bin filled with sandy clay loam soil. Tests were carried out with tillage tines to study the effect tool width on soil disturbance and draught. Depth of operation was held ...Experiments were conducted in an indoor soil bin filled with sandy clay loam soil. Tests were carried out with tillage tines to study the effect tool width on soil disturbance and draught. Depth of operation was held constant at 35 mm and then at 70 mm while speed was varied at three levels of 1.0, 3.6 and 9.0 km/h. The widths of the tines tested were 10, 20, 31, 40, 51, 88, 126, 163 and 200 mm. The cone penetration resistance of the soil varied from 400 to 600 kPa. Draught was measured with a load cell while soil disturbance was measured with a profile meter and meter rule. Draught increased at a decreasing rate with tine width. Quadratic models best fitted the data points with high R2 values. The increase in draught was affected by the forward speed since higher draught values were obtained at higher speed. Results show that the parameters of soil disturbance increased with increase in tine width, except height of ridge (hr), which did not show any specific trend. The specific draught was highest (10.63 N/cm) with tine T20 while Tine T1 had the least specific draught of 5.2 N/cm.展开更多
OBJECTIVE Alzheimer disease(AD)is a leading cause of dementia in elderly individuals and therapeutic options for AD are very limited.Over-activation of N-methyl-D-aspar⁃tate(NMDA)receptors,amyloidβ(Aβ)aggrega⁃tion,a...OBJECTIVE Alzheimer disease(AD)is a leading cause of dementia in elderly individuals and therapeutic options for AD are very limited.Over-activation of N-methyl-D-aspar⁃tate(NMDA)receptors,amyloidβ(Aβ)aggrega⁃tion,a decrease in cerebral blood flow(CBF),and downstream pathological events play impor⁃tant roles in the disease progression of AD.This study seeks to explore the efficacy and mecha⁃nism of action of MN-08,a novel memantine ni⁃trate,in established animal models of AD.METHODS MN-08′s effectiveness as a preventative and therapeutic agent was tested in 2-to 8-month-old APP/PS1 transgenic mice and 9-to 12-month-old 3×Tg-AD mice,respectively.The neuroprotective mechanism of MN-08 was tested in the glutamate cell model.The pharmacokinet⁃ics and safety of MN-08 in vivo were determined in normal rats and beagle dogs.For the behavioral test,Western blotting analysis,pathology,ELISA test and in vitro cell tests,investigators were blinded to the experimental grouping and drug treatment.RESULTS MN-08,a novel meman⁃tine nitrate,was found to inhibit Aβaccumulation,prevent neuronal and dendritic spine loss,and consequently attenuate cognitive deficits in 2-month-old APP/PS1 transgenic mice(for a 6-month preventative course)and in the 8-month-old triple-transgenic(3×Tg-AD)mice(for a 4-month therapeutic course).In vitro,MN-08 could bind to and antagonize NMDA receptors,inhibit the calcium influx,and reverse the dysregula⁃tions of ERK and PI3K/Akt/GSK3βpathway,sub⁃sequently preventing glutamate-induced neuro⁃nal loss.In addition,MN-08 had favorable phar⁃macokinetics,blood-brain barrier penetration,and safety profiles in rats and beagle dogs.CON⁃CLUSION The novel memantine nitrate MN-08 may be a useful therapeutic agent for AD.展开更多
Objective: To review the evidence surrounding Sacral Neuromodulation therapy and delineate areas that will need more research. Methods: An extensive search was performed on the available literature on SNM for lower ur...Objective: To review the evidence surrounding Sacral Neuromodulation therapy and delineate areas that will need more research. Methods: An extensive search was performed on the available literature on SNM for lower urinary tract dysfunction. Based on the results of the search, the mechanisms of action, indications, technique, and patient characteristics of therapy failures and success are presented and discussed. Results: SNM is accepted by the FDA since 1997 for the treatment of lower urinary tract dysfunction. As it is a relatively new procedure, there are variations in the technique of lead placement, generator choice, testing interval, patient selection, time to explantation, and definitions of therapy failures and successes. Conclusions: SNM is a safe and therapeutic option for the treatment of urgencyfrequency syndrome, urge incontinence, and idiopathic urinary retention. However, there are multiple unanswered questions that require extensive research.展开更多
The structural parameters of tine furrow openers have significant effects on soil property of seed furrow in no-till planting,thereby affecting crop growth and yields.In order to analyze the effects of key parameters ...The structural parameters of tine furrow openers have significant effects on soil property of seed furrow in no-till planting,thereby affecting crop growth and yields.In order to analyze the effects of key parameters of tine furrow openers on soil properties(soil bulk density,soil water-stable aggregates(WSA),and soil disturbance)of the surface soil layer of 0-10 cm and surface straw disturbance,the tine furrow openers with different structural parameters,including cutting edge thickness,cutting edge curve,penetration clearance angle and rake angle,were designed and tested under no-till conditions.Orthogonal test and single factor test were performed to analyze the effects of different parameters.Results showed that the rake angle,cutting edge thickness and cutting edge curve had significant effects on cross-sectional area of furrow(Af)and disturbance of surface straw;the rake angle had a significant effect on soil bulk density.Soil types and operating depth had significant effects on soil disturbance caused by tine furrow openers.The concave type tine furrow opener produced the lowest soil disturbance and soil bulk density of seed furrow,the highest surface straw disturbance and the greatest content of WSA(>0.5 mm).With increasing rake angles of tine furrow opener,the width of seedbed(Wsb)and the Af decreased first and then increased,respectively,while the width of soil throw(Wst)and the height of ridge(Hr)increased.The Wsb and Af created by tine furrow opener with 60°rake angle were significantly lower than that with others,respectively.The tine furrow opener with rake angle ranged from 45°to 60°created the lowest soil bulk density.As the penetration clearance angle increased,the content of WSA(>0.5 mm)decreased,but the effect of penetration clearance angle on the content of WSA(<0.5 mm)was not significant.The cutting edge thickness(<2 mm)had no significant effects on soil properties of seedbed.This study could provide a reference for optimal design of the tine furrow opener to create more suitable seedbed environment,and promote the application of the light no-till planters.展开更多
This paper deals with study of generalized Chaplygin gas model with dynamical gravitational and cosmological constants. In this paper a new set of exact solutions of Einstein field equations for spatially homogeneous ...This paper deals with study of generalized Chaplygin gas model with dynamical gravitational and cosmological constants. In this paper a new set of exact solutions of Einstein field equations for spatially homogeneous and anisotropic Bianchi type Ⅰ space-time have been obtained. The solutions of the Einstein's field equations are obtained by considering(i) the power law relation between Hubble parameter H and scale factor R and(ii) scale factor of the form R =-1/t + t^2, t > 1. The assumptions lead to constant and variable deceleration parameter respectively. The physical and dynamical behaviors of the models have been discussed with the help of graphical representations. Also we have discussed the stability and physical acceptability of solutions for solution type-Ⅰ and solution type-Ⅱ.展开更多
文摘Experiments were conducted in an indoor soil bin filled with sandy clay loam soil. Tests were carried out with tillage tines to study the effect tool width on soil disturbance and draught. Depth of operation was held constant at 35 mm and then at 70 mm while speed was varied at three levels of 1.0, 3.6 and 9.0 km/h. The widths of the tines tested were 10, 20, 31, 40, 51, 88, 126, 163 and 200 mm. The cone penetration resistance of the soil varied from 400 to 600 kPa. Draught was measured with a load cell while soil disturbance was measured with a profile meter and meter rule. Draught increased at a decreasing rate with tine width. Quadratic models best fitted the data points with high R2 values. The increase in draught was affected by the forward speed since higher draught values were obtained at higher speed. Results show that the parameters of soil disturbance increased with increase in tine width, except height of ridge (hr), which did not show any specific trend. The specific draught was highest (10.63 N/cm) with tine T20 while Tine T1 had the least specific draught of 5.2 N/cm.
文摘OBJECTIVE Alzheimer disease(AD)is a leading cause of dementia in elderly individuals and therapeutic options for AD are very limited.Over-activation of N-methyl-D-aspar⁃tate(NMDA)receptors,amyloidβ(Aβ)aggrega⁃tion,a decrease in cerebral blood flow(CBF),and downstream pathological events play impor⁃tant roles in the disease progression of AD.This study seeks to explore the efficacy and mecha⁃nism of action of MN-08,a novel memantine ni⁃trate,in established animal models of AD.METHODS MN-08′s effectiveness as a preventative and therapeutic agent was tested in 2-to 8-month-old APP/PS1 transgenic mice and 9-to 12-month-old 3×Tg-AD mice,respectively.The neuroprotective mechanism of MN-08 was tested in the glutamate cell model.The pharmacokinet⁃ics and safety of MN-08 in vivo were determined in normal rats and beagle dogs.For the behavioral test,Western blotting analysis,pathology,ELISA test and in vitro cell tests,investigators were blinded to the experimental grouping and drug treatment.RESULTS MN-08,a novel meman⁃tine nitrate,was found to inhibit Aβaccumulation,prevent neuronal and dendritic spine loss,and consequently attenuate cognitive deficits in 2-month-old APP/PS1 transgenic mice(for a 6-month preventative course)and in the 8-month-old triple-transgenic(3×Tg-AD)mice(for a 4-month therapeutic course).In vitro,MN-08 could bind to and antagonize NMDA receptors,inhibit the calcium influx,and reverse the dysregula⁃tions of ERK and PI3K/Akt/GSK3βpathway,sub⁃sequently preventing glutamate-induced neuro⁃nal loss.In addition,MN-08 had favorable phar⁃macokinetics,blood-brain barrier penetration,and safety profiles in rats and beagle dogs.CON⁃CLUSION The novel memantine nitrate MN-08 may be a useful therapeutic agent for AD.
文摘Objective: To review the evidence surrounding Sacral Neuromodulation therapy and delineate areas that will need more research. Methods: An extensive search was performed on the available literature on SNM for lower urinary tract dysfunction. Based on the results of the search, the mechanisms of action, indications, technique, and patient characteristics of therapy failures and success are presented and discussed. Results: SNM is accepted by the FDA since 1997 for the treatment of lower urinary tract dysfunction. As it is a relatively new procedure, there are variations in the technique of lead placement, generator choice, testing interval, patient selection, time to explantation, and definitions of therapy failures and successes. Conclusions: SNM is a safe and therapeutic option for the treatment of urgencyfrequency syndrome, urge incontinence, and idiopathic urinary retention. However, there are multiple unanswered questions that require extensive research.
基金the Program for Innovative Research Team in Ministry of Education of China(Grant No.IRT13039)the National Natural Science Foundation of China(Grants No.51175499)。
文摘The structural parameters of tine furrow openers have significant effects on soil property of seed furrow in no-till planting,thereby affecting crop growth and yields.In order to analyze the effects of key parameters of tine furrow openers on soil properties(soil bulk density,soil water-stable aggregates(WSA),and soil disturbance)of the surface soil layer of 0-10 cm and surface straw disturbance,the tine furrow openers with different structural parameters,including cutting edge thickness,cutting edge curve,penetration clearance angle and rake angle,were designed and tested under no-till conditions.Orthogonal test and single factor test were performed to analyze the effects of different parameters.Results showed that the rake angle,cutting edge thickness and cutting edge curve had significant effects on cross-sectional area of furrow(Af)and disturbance of surface straw;the rake angle had a significant effect on soil bulk density.Soil types and operating depth had significant effects on soil disturbance caused by tine furrow openers.The concave type tine furrow opener produced the lowest soil disturbance and soil bulk density of seed furrow,the highest surface straw disturbance and the greatest content of WSA(>0.5 mm).With increasing rake angles of tine furrow opener,the width of seedbed(Wsb)and the Af decreased first and then increased,respectively,while the width of soil throw(Wst)and the height of ridge(Hr)increased.The Wsb and Af created by tine furrow opener with 60°rake angle were significantly lower than that with others,respectively.The tine furrow opener with rake angle ranged from 45°to 60°created the lowest soil bulk density.As the penetration clearance angle increased,the content of WSA(>0.5 mm)decreased,but the effect of penetration clearance angle on the content of WSA(<0.5 mm)was not significant.The cutting edge thickness(<2 mm)had no significant effects on soil properties of seedbed.This study could provide a reference for optimal design of the tine furrow opener to create more suitable seedbed environment,and promote the application of the light no-till planters.
文摘This paper deals with study of generalized Chaplygin gas model with dynamical gravitational and cosmological constants. In this paper a new set of exact solutions of Einstein field equations for spatially homogeneous and anisotropic Bianchi type Ⅰ space-time have been obtained. The solutions of the Einstein's field equations are obtained by considering(i) the power law relation between Hubble parameter H and scale factor R and(ii) scale factor of the form R =-1/t + t^2, t > 1. The assumptions lead to constant and variable deceleration parameter respectively. The physical and dynamical behaviors of the models have been discussed with the help of graphical representations. Also we have discussed the stability and physical acceptability of solutions for solution type-Ⅰ and solution type-Ⅱ.