Both the repeated triaxial test （RTT） and the Hamburg wheel tracking test （HWTT） are adopted to evaluate the high temperature performance of the stone mastic asphalt （SMA） and the mastic asphalt （MA）. The corr...Both the repeated triaxial test （RTT） and the Hamburg wheel tracking test （HWTT） are adopted to evaluate the high temperature performance of the stone mastic asphalt （SMA） and the mastic asphalt （MA）. The correlation of the permanent deformations of the MA and the correlation of the deformation developments of the SMA between the two tests are analyzed, respectively. Results show that both the two tests can effectively identify the high temperature performance of mixtures, and the correlation between the final results of the two tests as well as that between the deformation developments of the two tests are excellent with R20.9. In order to further prove the correlation, viscoelastic parameters estimated from the RTT results is used to simulate the rutting development in the HWTT slabs by the finite element method （FEM）. Results indicate that the correlation between the two tests is significant with errors less than 10%. It is suitable to predict the rutting development with the viscoelastic parameters obtained from the RTT.展开更多
Objective The present study was undertaken to evaluate the subchronic toxicity of lanthanum and to determine the no observed adverse effect level（NOAEL）,which is a critical factor in the establishment of an acceptab...Objective The present study was undertaken to evaluate the subchronic toxicity of lanthanum and to determine the no observed adverse effect level（NOAEL）,which is a critical factor in the establishment of an acceptable dietary intake（ADI）.Methods In accordance with the Organization for Economic Co-operation and Development（OECD） testing guidelines,lanthanum nitrate was administered once daily by gavage to Sprague-Dawley（SD） rats at dose levels of 0,1.5,6.0,24.0,and 144.0 mg/kg body weight（BW） per day for 90 days,followed by a recovery period of 4 weeks in the 144.0 mg/kg BW per day and normal control groups.Outcome parameters were mortality,clinical symptoms,body and organ weights,serum chemistry,and food consumption,as well as ophthalmic,urinary,hematologic,and histopathologic indicators.The benchmark dose（BMD） approach was applied to estimate a point of departure for the hazard risk assessment of lanthanum.Results Significant decreases were found in the 144.0 mg/kg BW group in the growth index,including body weight,organ weights,and food consumption.This study suggests that the NOAEL of lanthanum nitrate is 24.0 mg/kg BW per day.Importantly,the 95% lower confidence value of the benchmark dose（BMDL） was estimated as 9.4 mg/kg BW per day in females and 19.3 mg/kg BW per day in males.Conclusion The present subchronic oral exposure toxicity study may provide scientific data for the risk assessment of lanthanum and other rare earth elements（REEs）.展开更多
Practical assessment of subgrade settlement induced by train operation requires developing suitable models capable of describing permanent deformation characteristics of subgrade filling under repeated dynamic loading...Practical assessment of subgrade settlement induced by train operation requires developing suitable models capable of describing permanent deformation characteristics of subgrade filling under repeated dynamic loading.In this paper,repeated load triaxial tests were performed on coarse-grained soil(CGS),and the axial permanent strain of CGS under different confining pressures and dynamic stress amplitudes was analysed.Permanent deformation behaviors of CGS were categorized based on the variation trend of permanent strain rate with accumulated permanent strain and the shakedown theory.A prediction model of permanent deformation considering stress state and number of load cycles was established,and the ranges of parameters for different types of dynamic behaviors were also divided.The results indicated that the variational trend of permanent strain rate with accumulated permanent strain can be used as a basis for classifying dynamic behaviors of CGS.The stress state(confining pressure and dynamic stress amplitude)has significant effects on the permanent strain rate.The accumulative characteristics of permanent deformation of CGS with the number of load cycles can be described by a power function,and the model parameters can reflect the influence of confining pressure and dynamic stress amplitude.The study’s results could help deepen understanding of the permanent deformation characteristics of CGS.展开更多
Objective The present study was undertaken to evaluate the subchronic oral toxicity of sodium dehydroacetate(DHA-Na)and to determine the point of departure(POD),which is a critical factor in the establishment of an ac...Objective The present study was undertaken to evaluate the subchronic oral toxicity of sodium dehydroacetate(DHA-Na)and to determine the point of departure(POD),which is a critical factor in the establishment of an acceptable dietary intake.Methods DHA-Na was administered once daily by gavage to Sprague–Dawley rats at dose levels of 0.0,31.0,62.0,and 124.0 mg/kg BW per day for 90 days,followed by a recovery period of 4 weeks in the control and 124.0 mg/kg BW per day groups.The outcome parameters were mortality,clinical observations,body weights,food consumption,hematology and clinical biochemistry,endocrine hormone levels,and ophthalmic,urinary,and histopathologic indicators.The benchmark dose(BMD)approach was applied to estimate the POD.Results Significant decreases were found in the 62.0 and 124.0 mg/kg BW groups in terms of the body weight and food utilization rate,whereas a significant increase was found in the thyroid stimulating hormone levels of the 124.0 mg/kg BW group.Importantly,the 95%lower confidence limit on the BMD of 51.7 mg/kg BW was modeled for a reduction in body weight.Conclusion The repeated-dose study indicated the slight systemic toxicity of DHA-Na at certain levels(62.0 and 124.0 mg/kg BW)after a 90-day oral exposure.展开更多
The objectives of this study were to construct a database of expressed sequence tag (EST)-simple sequence repeat (SSR) markers to identify lettuce cultivars. A set of 370 EST-SSR primer pairs were applied for fingerpr...The objectives of this study were to construct a database of expressed sequence tag (EST)-simple sequence repeat (SSR) markers to identify lettuce cultivars. A set of 370 EST-SSR primer pairs were applied for fingerprinting the lettuce cultivars. Fifty-eight EST-SSR markers showed hy-per-variability and were able to differentiate 92 cultivars. A total of 176 polymorphic amplified fragments were obtained by the 58 markers, and two to eight SSR alleles were detected for each l°Cus with an average of three alleles per locus. Average polymorphism information content (PIC) was 0.425, ranging from 0.022 to 0.743. Cluster analysis was based on Jaccard’s distance coefficients using the method of unweighted pair group. In this method we used arithmetical averages (UPGMA) algorithm categorized 4 major groups, which were in accordance to morphological traits. The eight cultivars of three groups with 100% genetic similarity through SSR analysis were investigated by phenotypic traits. These cultivars including these pairs are very similar in 27 morphological characteristics. Therefore, these EST-SSR markers could be used to select similar cultivars through management of reference collection to complement distinctiveness test of lettuce cultivars.展开更多
The ability of psammophyte photosynthesis to withstand and recover from severe droughts is crucial for vegetation sta- bility in semi-arid sandy lands. The responses of gas exchange and chlorophyll fluorescence of an ...The ability of psammophyte photosynthesis to withstand and recover from severe droughts is crucial for vegetation sta- bility in semi-arid sandy lands. The responses of gas exchange and chlorophyll fluorescence of an annual grass, Digitaria ciliaris, were measured through three soil drought and rewatering cycles. Results showed that the net photosynthesis rate （P,） decreased by 92%, 95%, and 63% at end of the three drought periods, respectively, water use efficiency （WUE） decreased by 67%, 54%, and 48%, while the constant intercellular CO2 concentration （Ci） increased by 1.08, 0.88, and 0.45 times. During those three cycles, the trapping probability with no dark adaptation （Fv＇/Fm＇） decreased by 55%, 51%, and 9%, the electron transport per cross section （ET0＇/CS0＇） decreased by 63%0, 42%, and 18%, and the dissipation per cross section （DI0＇/CS0＇） increased by 97%, 96%, and 21%. These results indicated that D. ciliaris was subjected to photoinhi- bition and some non-stomatal limitation of photosynthesis under drought. However, after four days of rewatering, its photosynthetic characteristics were restored to control values. This capability to recover from drought may contribute to making the plant＇s use of water as efficient as possible. Furthermore, the photosynthesis decreased more slowly in the subsequent drought cycles than in the first cycle, allowing D. ciliaris to enhance its future drought tolerance after drought hardening. Thus, it acclimatizes itself to repeated soil drought.展开更多
The effect of tire repeated root modal（RRM）on tire modeling with an experimental modal is studied.Firstly,a radial tire with radial and tangential RRMs is tested and analyzed.By multi-point exciting of the radial ti...The effect of tire repeated root modal（RRM）on tire modeling with an experimental modal is studied.Firstly,a radial tire with radial and tangential RRMs is tested and analyzed.By multi-point exciting of the radial tire,a multiple reference frequency domain method based on a least squares（LMS PolyMAX）algorithm is used to identify modal parameters.Then,modal stability diagram（MSD）,modal indication function（MIF）and modal assurance criteria（Auto-MAC）matrix are utilized to induce multiple inputs multiple outputs（MIMO）frequency response function（FRF）matrixes.The tests reveal that notable repeated roots exist in both radial and tangential response modes.Their modal frequencies and damping factors are approximately the same,the amplitudes of modal vectors are in the same order of magnitude,and the mode shapes are orthogonal.Based on the works mentioned,the method of trigonometric series modal shapes fitting is adopted,the effects of RRM model on tire modeling with a vertical experimental modal are discussed.The final results show that the effects of considering the RRM shapes are equivalent to the tire mode shapes depended on rotating the tire’s different exciting points during tire modeling,and since considering the RRM,the tire mode shapes can be unified and fixed during tire modeling.展开更多
目的:分析江苏省汉族人群亲子鉴定中39个短串联重复序列(short tandem repeat,STR)基因座的突变特征。方法:选取2019年1月—2024年12月南京医科大学第一附属医院司法鉴定所受理的6812例亲子鉴定案例,采用GoldenEye^(TM) DNA身份鉴定系...目的:分析江苏省汉族人群亲子鉴定中39个短串联重复序列(short tandem repeat,STR)基因座的突变特征。方法:选取2019年1月—2024年12月南京医科大学第一附属医院司法鉴定所受理的6812例亲子鉴定案例,采用GoldenEye^(TM) DNA身份鉴定系统检测39个STR基因座的突变情况,对突变率、突变来源和步数进行统计分析。结果:在6812例认定亲子关系的案例中,三联体1680例,二联体5132例。共发现214例突变案例,总突变率2.52%。其中,D12S391基因座突变率最高,达0.3297%(28/8492),其次为Penta E、FGA、D21S11、D18S51、D3S1358基因座,突变率均在0.20%以上。突变来源分析中,父源突变189例,母源突变20例,不明原因突变5例,父源突变显著高于母源(P<0.001)。203例(94.86%)突变为一步突变,二步突变9例,FGA和D21S11基因座三步突变各1例。结论:亲子鉴定中39个STR基因座总突变率较高,达2.52%,具有性别和地区差异,在亲子鉴定实践中需加以重视,该结果为江苏地区汉族人群STR基因座突变情况提供数据支撑,有助于提升复杂亲缘关系鉴定的准确性。展开更多
基金The Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry (No.6821001005)
文摘Both the repeated triaxial test （RTT） and the Hamburg wheel tracking test （HWTT） are adopted to evaluate the high temperature performance of the stone mastic asphalt （SMA） and the mastic asphalt （MA）. The correlation of the permanent deformations of the MA and the correlation of the deformation developments of the SMA between the two tests are analyzed, respectively. Results show that both the two tests can effectively identify the high temperature performance of mixtures, and the correlation between the final results of the two tests as well as that between the deformation developments of the two tests are excellent with R20.9. In order to further prove the correlation, viscoelastic parameters estimated from the RTT results is used to simulate the rutting development in the HWTT slabs by the finite element method （FEM）. Results indicate that the correlation between the two tests is significant with errors less than 10%. It is suitable to predict the rutting development with the viscoelastic parameters obtained from the RTT.
基金supported by China Food Safety Talent Competency Development Initiative:CFSA 523 Programthe National Natural Science Foundation of China[No.81402683]
文摘Objective The present study was undertaken to evaluate the subchronic toxicity of lanthanum and to determine the no observed adverse effect level（NOAEL）,which is a critical factor in the establishment of an acceptable dietary intake（ADI）.Methods In accordance with the Organization for Economic Co-operation and Development（OECD） testing guidelines,lanthanum nitrate was administered once daily by gavage to Sprague-Dawley（SD） rats at dose levels of 0,1.5,6.0,24.0,and 144.0 mg/kg body weight（BW） per day for 90 days,followed by a recovery period of 4 weeks in the 144.0 mg/kg BW per day and normal control groups.Outcome parameters were mortality,clinical symptoms,body and organ weights,serum chemistry,and food consumption,as well as ophthalmic,urinary,hematologic,and histopathologic indicators.The benchmark dose（BMD） approach was applied to estimate a point of departure for the hazard risk assessment of lanthanum.Results Significant decreases were found in the 144.0 mg/kg BW group in the growth index,including body weight,organ weights,and food consumption.This study suggests that the NOAEL of lanthanum nitrate is 24.0 mg/kg BW per day.Importantly,the 95% lower confidence value of the benchmark dose（BMDL） was estimated as 9.4 mg/kg BW per day in females and 19.3 mg/kg BW per day in males.Conclusion The present subchronic oral exposure toxicity study may provide scientific data for the risk assessment of lanthanum and other rare earth elements（REEs）.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51878666 and 51678572).
文摘Practical assessment of subgrade settlement induced by train operation requires developing suitable models capable of describing permanent deformation characteristics of subgrade filling under repeated dynamic loading.In this paper,repeated load triaxial tests were performed on coarse-grained soil(CGS),and the axial permanent strain of CGS under different confining pressures and dynamic stress amplitudes was analysed.Permanent deformation behaviors of CGS were categorized based on the variation trend of permanent strain rate with accumulated permanent strain and the shakedown theory.A prediction model of permanent deformation considering stress state and number of load cycles was established,and the ranges of parameters for different types of dynamic behaviors were also divided.The results indicated that the variational trend of permanent strain rate with accumulated permanent strain can be used as a basis for classifying dynamic behaviors of CGS.The stress state(confining pressure and dynamic stress amplitude)has significant effects on the permanent strain rate.The accumulative characteristics of permanent deformation of CGS with the number of load cycles can be described by a power function,and the model parameters can reflect the influence of confining pressure and dynamic stress amplitude.The study’s results could help deepen understanding of the permanent deformation characteristics of CGS.
基金supported by the National Key R&D Program of China[2019YFC1605203]China Food Safety Talent Competency Development Initiative:CFSA 523 Program
文摘Objective The present study was undertaken to evaluate the subchronic oral toxicity of sodium dehydroacetate(DHA-Na)and to determine the point of departure(POD),which is a critical factor in the establishment of an acceptable dietary intake.Methods DHA-Na was administered once daily by gavage to Sprague–Dawley rats at dose levels of 0.0,31.0,62.0,and 124.0 mg/kg BW per day for 90 days,followed by a recovery period of 4 weeks in the control and 124.0 mg/kg BW per day groups.The outcome parameters were mortality,clinical observations,body weights,food consumption,hematology and clinical biochemistry,endocrine hormone levels,and ophthalmic,urinary,and histopathologic indicators.The benchmark dose(BMD)approach was applied to estimate the POD.Results Significant decreases were found in the 62.0 and 124.0 mg/kg BW groups in terms of the body weight and food utilization rate,whereas a significant increase was found in the thyroid stimulating hormone levels of the 124.0 mg/kg BW group.Importantly,the 95%lower confidence limit on the BMD of 51.7 mg/kg BW was modeled for a reduction in body weight.Conclusion The repeated-dose study indicated the slight systemic toxicity of DHA-Na at certain levels(62.0 and 124.0 mg/kg BW)after a 90-day oral exposure.
文摘The objectives of this study were to construct a database of expressed sequence tag (EST)-simple sequence repeat (SSR) markers to identify lettuce cultivars. A set of 370 EST-SSR primer pairs were applied for fingerprinting the lettuce cultivars. Fifty-eight EST-SSR markers showed hy-per-variability and were able to differentiate 92 cultivars. A total of 176 polymorphic amplified fragments were obtained by the 58 markers, and two to eight SSR alleles were detected for each l°Cus with an average of three alleles per locus. Average polymorphism information content (PIC) was 0.425, ranging from 0.022 to 0.743. Cluster analysis was based on Jaccard’s distance coefficients using the method of unweighted pair group. In this method we used arithmetical averages (UPGMA) algorithm categorized 4 major groups, which were in accordance to morphological traits. The eight cultivars of three groups with 100% genetic similarity through SSR analysis were investigated by phenotypic traits. These cultivars including these pairs are very similar in 27 morphological characteristics. Therefore, these EST-SSR markers could be used to select similar cultivars through management of reference collection to complement distinctiveness test of lettuce cultivars.
基金financially supported by the National Natural Science Foundation of China (No.41201249)the Open Fund of the Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions (No.SKLFSE201203)+2 种基金the National Science and Technology Support Program (No.2011BAC07B02)the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KZCX2-EW-QN313)the National Basic Research Program of China (No.2009CB421303)
文摘The ability of psammophyte photosynthesis to withstand and recover from severe droughts is crucial for vegetation sta- bility in semi-arid sandy lands. The responses of gas exchange and chlorophyll fluorescence of an annual grass, Digitaria ciliaris, were measured through three soil drought and rewatering cycles. Results showed that the net photosynthesis rate （P,） decreased by 92%, 95%, and 63% at end of the three drought periods, respectively, water use efficiency （WUE） decreased by 67%, 54%, and 48%, while the constant intercellular CO2 concentration （Ci） increased by 1.08, 0.88, and 0.45 times. During those three cycles, the trapping probability with no dark adaptation （Fv＇/Fm＇） decreased by 55%, 51%, and 9%, the electron transport per cross section （ET0＇/CS0＇） decreased by 63%0, 42%, and 18%, and the dissipation per cross section （DI0＇/CS0＇） increased by 97%, 96%, and 21%. These results indicated that D. ciliaris was subjected to photoinhi- bition and some non-stomatal limitation of photosynthesis under drought. However, after four days of rewatering, its photosynthetic characteristics were restored to control values. This capability to recover from drought may contribute to making the plant＇s use of water as efficient as possible. Furthermore, the photosynthesis decreased more slowly in the subsequent drought cycles than in the first cycle, allowing D. ciliaris to enhance its future drought tolerance after drought hardening. Thus, it acclimatizes itself to repeated soil drought.
文摘The effect of tire repeated root modal（RRM）on tire modeling with an experimental modal is studied.Firstly,a radial tire with radial and tangential RRMs is tested and analyzed.By multi-point exciting of the radial tire,a multiple reference frequency domain method based on a least squares（LMS PolyMAX）algorithm is used to identify modal parameters.Then,modal stability diagram（MSD）,modal indication function（MIF）and modal assurance criteria（Auto-MAC）matrix are utilized to induce multiple inputs multiple outputs（MIMO）frequency response function（FRF）matrixes.The tests reveal that notable repeated roots exist in both radial and tangential response modes.Their modal frequencies and damping factors are approximately the same,the amplitudes of modal vectors are in the same order of magnitude,and the mode shapes are orthogonal.Based on the works mentioned,the method of trigonometric series modal shapes fitting is adopted,the effects of RRM model on tire modeling with a vertical experimental modal are discussed.The final results show that the effects of considering the RRM shapes are equivalent to the tire mode shapes depended on rotating the tire’s different exciting points during tire modeling,and since considering the RRM,the tire mode shapes can be unified and fixed during tire modeling.
文摘目的:分析江苏省汉族人群亲子鉴定中39个短串联重复序列(short tandem repeat,STR)基因座的突变特征。方法:选取2019年1月—2024年12月南京医科大学第一附属医院司法鉴定所受理的6812例亲子鉴定案例,采用GoldenEye^(TM) DNA身份鉴定系统检测39个STR基因座的突变情况,对突变率、突变来源和步数进行统计分析。结果:在6812例认定亲子关系的案例中,三联体1680例,二联体5132例。共发现214例突变案例,总突变率2.52%。其中,D12S391基因座突变率最高,达0.3297%(28/8492),其次为Penta E、FGA、D21S11、D18S51、D3S1358基因座,突变率均在0.20%以上。突变来源分析中,父源突变189例,母源突变20例,不明原因突变5例,父源突变显著高于母源(P<0.001)。203例(94.86%)突变为一步突变,二步突变9例,FGA和D21S11基因座三步突变各1例。结论:亲子鉴定中39个STR基因座总突变率较高,达2.52%,具有性别和地区差异,在亲子鉴定实践中需加以重视,该结果为江苏地区汉族人群STR基因座突变情况提供数据支撑,有助于提升复杂亲缘关系鉴定的准确性。
