A greenhouse experiment was conducted to elucidate the growth changes and tissues anatomical characteristics of giant reed(Arundo donax L.),a perennial rhizomatous grass,which was cultivated for 70 d in soils contamin...A greenhouse experiment was conducted to elucidate the growth changes and tissues anatomical characteristics of giant reed(Arundo donax L.),a perennial rhizomatous grass,which was cultivated for 70 d in soils contaminated with As,Cd and Pb.The results show that giant reed rapidly grows with big biomass of shoots in contaminated soil,possessing strong metal-tolerance with limited metal translocation from roots to shoots.When As,Cd and Pb concentrations in the soil are less than 254,76.1 and 1 552 mg/kg,respectively,plant height and dried biomass are slightly reduced,the accumulation of As,Cd and Pb in shoots of giant reed is low while metal concentration in roots is high,and the anatomical characteristics of stem tissues are thick and homogeneous according to SEM images.However,plant height and dried biomass are significantly reduced and metal concentration in plant shoots and roots are significantly increased(P<0.05),the stems images become heterogeneous and the secretion in vascular bundles increases significantly when As,Cd and Pb concentrations in the soil exceed 334,101 and 2 052 mg/kg,respectively.The giant reed is a promising,naturally occurring plant with strong metal-tolerance,which can be cultivated in soils contaminated with multiple metals for ecoremediation purposes.展开更多
In view of the discrete characteristics of biological tissue, doublet mechanics has demonstrated its advantages in the mathematic description of tissue in terms of high frequency （〉 10 MHz） ultrasound. In this pape...In view of the discrete characteristics of biological tissue, doublet mechanics has demonstrated its advantages in the mathematic description of tissue in terms of high frequency （〉 10 MHz） ultrasound. In this paper, we take human breast biopsies as an example to study the influence of the internodal distance, a microscope parameter in biological tissue in doublet mechanics, on the sound velocity and attenuation by numerical simulation. The internodal distance causes the sound velocity and attenuation in biological tissue to change with the increase of frequency. The magnitude of such a change in pathological tissue is distinctly different from that in normal tissue, which can be used to differentiate pathological tissue from normal tissue and can depict the diseased tissue structure by obtaining the sound and attenuation distribution in the sample at high ultrasound frequency. A comparison of sensitivity between the doublet model and conventional continuum model is made, indicating that this is a new method of characterizing ultrasound tissue and diagnosing diseases.展开更多
基金Project(20507022) supported by the National Natural Science Foundation of China
文摘A greenhouse experiment was conducted to elucidate the growth changes and tissues anatomical characteristics of giant reed(Arundo donax L.),a perennial rhizomatous grass,which was cultivated for 70 d in soils contaminated with As,Cd and Pb.The results show that giant reed rapidly grows with big biomass of shoots in contaminated soil,possessing strong metal-tolerance with limited metal translocation from roots to shoots.When As,Cd and Pb concentrations in the soil are less than 254,76.1 and 1 552 mg/kg,respectively,plant height and dried biomass are slightly reduced,the accumulation of As,Cd and Pb in shoots of giant reed is low while metal concentration in roots is high,and the anatomical characteristics of stem tissues are thick and homogeneous according to SEM images.However,plant height and dried biomass are significantly reduced and metal concentration in plant shoots and roots are significantly increased(P<0.05),the stems images become heterogeneous and the secretion in vascular bundles increases significantly when As,Cd and Pb concentrations in the soil exceed 334,101 and 2 052 mg/kg,respectively.The giant reed is a promising,naturally occurring plant with strong metal-tolerance,which can be cultivated in soils contaminated with multiple metals for ecoremediation purposes.
基金Project supported by the National Basic Research Program of China(Grant Nos.2012CB921504 and 2011CB707902)the National Natural Science Foundation of China(Grant No.11274166)+3 种基金the Fundamental Research Funds for the Central Universities,China(Grant Nos.1113020403 and 1101020402)the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant No.SKLA201401)the China Postdoctoral Science Foundation(Grant No.2013M531313)the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions and Scientific Research Foundation for Returned Overseas Chinese Scholars,State Education Ministry,and the Project of Interdisciplinary Center of Nanjing University,China(Grant No.NJUDC2012004)
文摘In view of the discrete characteristics of biological tissue, doublet mechanics has demonstrated its advantages in the mathematic description of tissue in terms of high frequency （〉 10 MHz） ultrasound. In this paper, we take human breast biopsies as an example to study the influence of the internodal distance, a microscope parameter in biological tissue in doublet mechanics, on the sound velocity and attenuation by numerical simulation. The internodal distance causes the sound velocity and attenuation in biological tissue to change with the increase of frequency. The magnitude of such a change in pathological tissue is distinctly different from that in normal tissue, which can be used to differentiate pathological tissue from normal tissue and can depict the diseased tissue structure by obtaining the sound and attenuation distribution in the sample at high ultrasound frequency. A comparison of sensitivity between the doublet model and conventional continuum model is made, indicating that this is a new method of characterizing ultrasound tissue and diagnosing diseases.
