Auxin regulates cell division and elongation of the primordial cells through its concentration and then shaped the plant architecture. Cell division and elongation form the internode of soybean and result in different...Auxin regulates cell division and elongation of the primordial cells through its concentration and then shaped the plant architecture. Cell division and elongation form the internode of soybean and result in different plant heights and lodging resistance. Yet the mechanisms behind are unclear in soybean. To elucidate the mechanism of the concentration difference of auxin related to stem development in soybean, samples of apical shoot, elongation zone, and mature zone from the developing stems of soybean seedlings, Charleston, were harvested and measured for auxin concentration distributions and metabolites to identify the common underlying mechanisms responsible for concentration difference of auxin. Distribution of indole-3-acetic acid(IAA), indole-3-butyric acid(IBA), and methylindole-3-acetic acid(Me-IAA) were determined and auxin concentration distributions were found to have a complex regulation mechanism. The concentrations of IAA and Me-IAA in apical shoot were significantly different between elongation zone and mature zone resulting in an IAA gradient. Tryptophan dependent pathway from tryptamine directly to IAA or through indole-3-acetonitrile to IAA and from indole-3-propionic acid(IPA) to IAA were three primary IAA synthesis pathways. Moreover, some plant metabolites from flavonoid and phenylpropanoid synthesis pathways showed similar or reverse gradient and should involve in auxin homeostasis and concentration difference. All the data give the first insight in the concentration difference and homeostasis of auxin in soybean seedlings and facilitate a deeper understanding of the molecular mechanism of stem development and growth. The gathered information also helps to elucidate how plant height is formed in soybean and what strategy should be adopted to regulate the lodging resistance in soybean.展开更多
Blood alcohol concentration (BAC) differs greatly among individuals, even when people of the same sex and age drink alcohol under the same drinking conditions. In this study, we investigated the main factors involved ...Blood alcohol concentration (BAC) differs greatly among individuals, even when people of the same sex and age drink alcohol under the same drinking conditions. In this study, we investigated the main factors involved in the internal reg-ulation of individual differences in BAC, focusing on the alcohol dehydrogenase 1B (ADH1B) genotype, blood acetal-dehyde concentration (BAcH), amount of habitual alcohol consumption, pharmacokinetic parameters of BAC, distribution volume of ethanol (Vd), and gastric emptying rate (GER) under the same drinking conditions. Twenty healthy Japanese males aged between 40 and 59 years old and having the aldehyde dehydrogenase 2 (ALDH2) genotype of ALDH 2*1/*2 were recruited for this study. The subjects were given 0.32 g ethanol/kg body weight in the form of commercially available beer (5%, v/v). The results showed that BAC-max differed greatly among individuals with a more than two-fold variation. When the BAC-time curve was compared among ADH1B genotypes (ADH1B*1/*1, *1/*2, and *2/*2), there were no differences in BAC among the genotypes. Although BAcH, monthly alcohol consumption, elimination rate of blood ethanol (β value) and ethanol disappearance rate from the body (EDR) can affect BAC, all of them had no correlations with BAC-max. However, Vd (liter/kg), ΔPlasma glucose concentration (ΔPGC = PGC30 min ? PGC0 min) and the serum concentration of gastric inhibitory polypeptide (GIP) did correlate with BAC-max. Model 2 in multiple linear regression analysis showed the optimal model for Vd and GIP with positive correlations with BAC-max. As GIP and ΔPGC are both reflected by gastric emptying rate (GER), we concluded that the individual differences in BAC after moderate drinking are mainly regulated by GER together with Vd. These findings demonstrate that together with body water content, the gastrointestinal tract plays an important role in the regulation of individual differences in BAC, involving first pass metabolism of ethanol.展开更多
To evaluate the high-performance of membrane materials in the concentration of an aqueous solution of dilute bioethanol under temperature-difference controlled evapomeation (TDEV), asymmetric porous cellulose nitrate ...To evaluate the high-performance of membrane materials in the concentration of an aqueous solution of dilute bioethanol under temperature-difference controlled evapomeation (TDEV), asymmetric porous cellulose nitrate (CN) and cellulose acetate (CA) membranes were prepared by a phase inversion method. In the concentration of dilute ethanol under TDEV, these membranes showed a high permeation rate and high ethanol/water selectivity. In membranes with almost the similar pore size, the ethanol/water selectivity was considerably higher for the CN membrane than the corresponding CA membrane. This result suggested that the affinity between the membrane material and the permeant is an important factor in the separation selectivity.展开更多
The tested soils containing different Cd levels were obtained by mixing the normal cultivated soils with the Cd-contaminated soils taken from the paddies near a mine. Five major categories of vegetables, i.e. cucumber...The tested soils containing different Cd levels were obtained by mixing the normal cultivated soils with the Cd-contaminated soils taken from the paddies near a mine. Five major categories of vegetables, i.e. cucumber, cowpea, Bok choy, radish and lettuce, widely planted in the spring and autumn in Hunan Province, were selected for pool-culture experiments. Results showed that the Cd accumulations varied greatly according to the category of vegetables. The Cd accumulations in cucumber and cowpea growing in soils with high Cd levels (1.5 mg/kg) were within the threshold limits of the national standards, meaning that these two categories are safe to grow in Cd-contaminated soils. For either the cucumber or the cowpea category, there were no significant differences in the Cd accumulations of different genotypes. Most of the tested Bok choy and radish cultivars could grow safely in soils whose Cd levels were below 1.0 mg/kg. In comparison, the Cd accumulations in some cultivars tended to increase sharply as the Cd level in the soil went beyond 1.0 mg/kg. Significant variations were also observed in the Cd accumulations of different genotypes with mounting Cd levels in the soil. Besides, there were no positive correlations between Cd accumulations in plants and Cd levels in soils, indicating large fluctuations and poor ecological stability of Bok choy and radish. Therefore, the planting of Bok choy and radish should be strictly evaluated and controlled in Cdcontaminated regions. The Cd contents of most celtuce cultivars growing in mildlycontaminated soils had already exceeded the threshold limit. Therefore, it is not safe for celtuce to grow in Cd-contaminated environments.展开更多
Structure of porous media and fluid distribution in rocks can significantly affect the transport characteristics during the process of microscale tracer flow.To clarify the effect of micro heterogeneity on aqueous tra...Structure of porous media and fluid distribution in rocks can significantly affect the transport characteristics during the process of microscale tracer flow.To clarify the effect of micro heterogeneity on aqueous tracer transport,this paper demonstrates microscopic experiments at pore level and proposes an improved mathematical model for tracer transport.The visualization results show a faster tracer movement into movable water than it into bound water,and quicker occupancy in flowing pores than in storage pores caused by the difference of tracer velocity.Moreover,the proposed mathematical model includes the effects of bound water and flowing porosity by applying interstitial flow velocity expression.The new model also distinguishes flowing and storage pores,accounting for different tracer transport mechanisms(dispersion,diffusion and adsorption)in different types of pores.The resulting analytical solution better matches with tracer production data than the standard model.The residual sum of squares(RSS)from the new model is 0.0005,which is 100 times smaller than the RSS from the standard model.The sensitivity analysis indicates that the dispersion coefficient and flowing porosity shows a negative correlation with the tracer breakthrough time and the increasing slope,whereas the superficial velocity and bound water saturation show a positive correlation.展开更多
The goals of this study were to examine, using the temporal dominance of sensations (TDS) method, the effects of 1) the sucrose concentration on the temporal sequence of sweetness perception in four fruit-flavored (le...The goals of this study were to examine, using the temporal dominance of sensations (TDS) method, the effects of 1) the sucrose concentration on the temporal sequence of sweetness perception in four fruit-flavored (lemon, peach, strawberry, and vanilla) teas with 0.05, 0.15, and 0.25 M sucrose;and 2) participants’ sex on this temporal sequence. Twenty-four healthy young adults were assigned to female (n = 12) and male (n = 12) groups. Both groups evaluated five sensory attributes in 12 samples (four fruit-flavored teas, each with three sucrose concentrations). As in our preceding study [1], two sensations, sweetness and fruitiness, were dominant after ingesting the 12 teas in both groups, but the temporal sequence of sweetness perception differed between the two groups. On average, the male group reported the first appearance of sweetness earlier in the samples with 0.05 M sucrose compared with the female group, with the samples containing 0.15 and 0.25 M sucrose. The average durations of the sweetness sensation were different between the male and female groups as well as among the sucrose concentrations and the four flavors tested.展开更多
The impact of magnetic field on the corrosion behavior of Al-Mg-xR_(E)/Fe alloys in NaCl solutions with concentrations of 1.5wt%,3.5wt%,and 5.5wt%were studied by microstructure observation,immersion test,and electroch...The impact of magnetic field on the corrosion behavior of Al-Mg-xR_(E)/Fe alloys in NaCl solutions with concentrations of 1.5wt%,3.5wt%,and 5.5wt%were studied by microstructure observation,immersion test,and electrochemical test.The combined impacts of magnetic field and chloride ion concentration on the corrosion behavior of Al-Mg alloys with various electrode potential phases were discussed.The results indicate that Al-3.0Mg-xR_(E)/Fe alloys corrode faster and have a higher pitting corrosion potential in the NaCl solution with a higher concentration.In addition,a magnetic field can lower the pitting sensitivity and corrosion rate of Al-3.0Mg and Al-3.0Mg-0.2R_(E)/Fe alloys in NaCl solution with different concentrations.However,at a higher concentration of NaCl solution,the magnetic field has a weaker inhibiting effect on corrosion rate and pitting sensitivity.In NaCl solutions with concentrations of 1.5wt%and 3.5wt%,the corrosion rate and pitting sensitivity of Al-3.0Mg-1.0R_(E)/Fe alloys can be reduced by a magnetic field.However,in NaCl solution with the concentration of 5.5wt%,the corrosion rate of the alloys is increased by a magnetic field.展开更多
This paper employs computer colour generation,and match prediction systems and aims tofind the most critical change of dye concentration corresponding to changes of Hue,or Chroma,orLightness of 1 unit just visible col...This paper employs computer colour generation,and match prediction systems and aims tofind the most critical change of dye concentration corresponding to changes of Hue,or Chroma,orLightness of 1 unit just visible colour difference,thus investigating the required accuracy level fordyeing dispensing.This leads to the selection of one critical colour-difference dimension of threefrom CMC (1:c) measurement.The results reveal that the concentration change in dye dispensing ismost critical for change of Hue in a computer controlled system.The formula describing the rela-tionship Of △E and △H in CMC (2:1) measurement is selected for further investigation.展开更多
基金financially supported by the National Natural Science Foundation of China(31571693)the earmarked fund for China Agriculture Research System(CARS-04-04B)。
文摘Auxin regulates cell division and elongation of the primordial cells through its concentration and then shaped the plant architecture. Cell division and elongation form the internode of soybean and result in different plant heights and lodging resistance. Yet the mechanisms behind are unclear in soybean. To elucidate the mechanism of the concentration difference of auxin related to stem development in soybean, samples of apical shoot, elongation zone, and mature zone from the developing stems of soybean seedlings, Charleston, were harvested and measured for auxin concentration distributions and metabolites to identify the common underlying mechanisms responsible for concentration difference of auxin. Distribution of indole-3-acetic acid(IAA), indole-3-butyric acid(IBA), and methylindole-3-acetic acid(Me-IAA) were determined and auxin concentration distributions were found to have a complex regulation mechanism. The concentrations of IAA and Me-IAA in apical shoot were significantly different between elongation zone and mature zone resulting in an IAA gradient. Tryptophan dependent pathway from tryptamine directly to IAA or through indole-3-acetonitrile to IAA and from indole-3-propionic acid(IPA) to IAA were three primary IAA synthesis pathways. Moreover, some plant metabolites from flavonoid and phenylpropanoid synthesis pathways showed similar or reverse gradient and should involve in auxin homeostasis and concentration difference. All the data give the first insight in the concentration difference and homeostasis of auxin in soybean seedlings and facilitate a deeper understanding of the molecular mechanism of stem development and growth. The gathered information also helps to elucidate how plant height is formed in soybean and what strategy should be adopted to regulate the lodging resistance in soybean.
文摘Blood alcohol concentration (BAC) differs greatly among individuals, even when people of the same sex and age drink alcohol under the same drinking conditions. In this study, we investigated the main factors involved in the internal reg-ulation of individual differences in BAC, focusing on the alcohol dehydrogenase 1B (ADH1B) genotype, blood acetal-dehyde concentration (BAcH), amount of habitual alcohol consumption, pharmacokinetic parameters of BAC, distribution volume of ethanol (Vd), and gastric emptying rate (GER) under the same drinking conditions. Twenty healthy Japanese males aged between 40 and 59 years old and having the aldehyde dehydrogenase 2 (ALDH2) genotype of ALDH 2*1/*2 were recruited for this study. The subjects were given 0.32 g ethanol/kg body weight in the form of commercially available beer (5%, v/v). The results showed that BAC-max differed greatly among individuals with a more than two-fold variation. When the BAC-time curve was compared among ADH1B genotypes (ADH1B*1/*1, *1/*2, and *2/*2), there were no differences in BAC among the genotypes. Although BAcH, monthly alcohol consumption, elimination rate of blood ethanol (β value) and ethanol disappearance rate from the body (EDR) can affect BAC, all of them had no correlations with BAC-max. However, Vd (liter/kg), ΔPlasma glucose concentration (ΔPGC = PGC30 min ? PGC0 min) and the serum concentration of gastric inhibitory polypeptide (GIP) did correlate with BAC-max. Model 2 in multiple linear regression analysis showed the optimal model for Vd and GIP with positive correlations with BAC-max. As GIP and ΔPGC are both reflected by gastric emptying rate (GER), we concluded that the individual differences in BAC after moderate drinking are mainly regulated by GER together with Vd. These findings demonstrate that together with body water content, the gastrointestinal tract plays an important role in the regulation of individual differences in BAC, involving first pass metabolism of ethanol.
文摘To evaluate the high-performance of membrane materials in the concentration of an aqueous solution of dilute bioethanol under temperature-difference controlled evapomeation (TDEV), asymmetric porous cellulose nitrate (CN) and cellulose acetate (CA) membranes were prepared by a phase inversion method. In the concentration of dilute ethanol under TDEV, these membranes showed a high permeation rate and high ethanol/water selectivity. In membranes with almost the similar pore size, the ethanol/water selectivity was considerably higher for the CN membrane than the corresponding CA membrane. This result suggested that the affinity between the membrane material and the permeant is an important factor in the separation selectivity.
文摘The tested soils containing different Cd levels were obtained by mixing the normal cultivated soils with the Cd-contaminated soils taken from the paddies near a mine. Five major categories of vegetables, i.e. cucumber, cowpea, Bok choy, radish and lettuce, widely planted in the spring and autumn in Hunan Province, were selected for pool-culture experiments. Results showed that the Cd accumulations varied greatly according to the category of vegetables. The Cd accumulations in cucumber and cowpea growing in soils with high Cd levels (1.5 mg/kg) were within the threshold limits of the national standards, meaning that these two categories are safe to grow in Cd-contaminated soils. For either the cucumber or the cowpea category, there were no significant differences in the Cd accumulations of different genotypes. Most of the tested Bok choy and radish cultivars could grow safely in soils whose Cd levels were below 1.0 mg/kg. In comparison, the Cd accumulations in some cultivars tended to increase sharply as the Cd level in the soil went beyond 1.0 mg/kg. Significant variations were also observed in the Cd accumulations of different genotypes with mounting Cd levels in the soil. Besides, there were no positive correlations between Cd accumulations in plants and Cd levels in soils, indicating large fluctuations and poor ecological stability of Bok choy and radish. Therefore, the planting of Bok choy and radish should be strictly evaluated and controlled in Cdcontaminated regions. The Cd contents of most celtuce cultivars growing in mildlycontaminated soils had already exceeded the threshold limit. Therefore, it is not safe for celtuce to grow in Cd-contaminated environments.
基金funded by National Science and Technology Major Projects(2017ZX05009004,2016ZX05058003)Beijing Natural Science Foundation(2173061)and State Energy Center for Shale Oil Research and Development(G5800-16-ZS-KFNY005).
文摘Structure of porous media and fluid distribution in rocks can significantly affect the transport characteristics during the process of microscale tracer flow.To clarify the effect of micro heterogeneity on aqueous tracer transport,this paper demonstrates microscopic experiments at pore level and proposes an improved mathematical model for tracer transport.The visualization results show a faster tracer movement into movable water than it into bound water,and quicker occupancy in flowing pores than in storage pores caused by the difference of tracer velocity.Moreover,the proposed mathematical model includes the effects of bound water and flowing porosity by applying interstitial flow velocity expression.The new model also distinguishes flowing and storage pores,accounting for different tracer transport mechanisms(dispersion,diffusion and adsorption)in different types of pores.The resulting analytical solution better matches with tracer production data than the standard model.The residual sum of squares(RSS)from the new model is 0.0005,which is 100 times smaller than the RSS from the standard model.The sensitivity analysis indicates that the dispersion coefficient and flowing porosity shows a negative correlation with the tracer breakthrough time and the increasing slope,whereas the superficial velocity and bound water saturation show a positive correlation.
文摘The goals of this study were to examine, using the temporal dominance of sensations (TDS) method, the effects of 1) the sucrose concentration on the temporal sequence of sweetness perception in four fruit-flavored (lemon, peach, strawberry, and vanilla) teas with 0.05, 0.15, and 0.25 M sucrose;and 2) participants’ sex on this temporal sequence. Twenty-four healthy young adults were assigned to female (n = 12) and male (n = 12) groups. Both groups evaluated five sensory attributes in 12 samples (four fruit-flavored teas, each with three sucrose concentrations). As in our preceding study [1], two sensations, sweetness and fruitiness, were dominant after ingesting the 12 teas in both groups, but the temporal sequence of sweetness perception differed between the two groups. On average, the male group reported the first appearance of sweetness earlier in the samples with 0.05 M sucrose compared with the female group, with the samples containing 0.15 and 0.25 M sucrose. The average durations of the sweetness sensation were different between the male and female groups as well as among the sucrose concentrations and the four flavors tested.
基金by the National Natural Science Foundation of China(No.51909071)the Natural Science Foundation of Jiangsu Province(No.BK20190493)the Fundamental Research Funds for the Central Universities(No.B220202040)。
文摘The impact of magnetic field on the corrosion behavior of Al-Mg-xR_(E)/Fe alloys in NaCl solutions with concentrations of 1.5wt%,3.5wt%,and 5.5wt%were studied by microstructure observation,immersion test,and electrochemical test.The combined impacts of magnetic field and chloride ion concentration on the corrosion behavior of Al-Mg alloys with various electrode potential phases were discussed.The results indicate that Al-3.0Mg-xR_(E)/Fe alloys corrode faster and have a higher pitting corrosion potential in the NaCl solution with a higher concentration.In addition,a magnetic field can lower the pitting sensitivity and corrosion rate of Al-3.0Mg and Al-3.0Mg-0.2R_(E)/Fe alloys in NaCl solution with different concentrations.However,at a higher concentration of NaCl solution,the magnetic field has a weaker inhibiting effect on corrosion rate and pitting sensitivity.In NaCl solutions with concentrations of 1.5wt%and 3.5wt%,the corrosion rate and pitting sensitivity of Al-3.0Mg-1.0R_(E)/Fe alloys can be reduced by a magnetic field.However,in NaCl solution with the concentration of 5.5wt%,the corrosion rate of the alloys is increased by a magnetic field.
文摘This paper employs computer colour generation,and match prediction systems and aims tofind the most critical change of dye concentration corresponding to changes of Hue,or Chroma,orLightness of 1 unit just visible colour difference,thus investigating the required accuracy level fordyeing dispensing.This leads to the selection of one critical colour-difference dimension of threefrom CMC (1:c) measurement.The results reveal that the concentration change in dye dispensing ismost critical for change of Hue in a computer controlled system.The formula describing the rela-tionship Of △E and △H in CMC (2:1) measurement is selected for further investigation.
