Iodine is an element that is essential for the synthesis of thyroid hormones.Adequate intake of dietary iodine has been recognized as a critical factor for maintaining health.It is a well-known fact that iodine defici...Iodine is an element that is essential for the synthesis of thyroid hormones.Adequate intake of dietary iodine has been recognized as a critical factor for maintaining health.It is a well-known fact that iodine deficiency can impede the production of thyroid hormones in both the mother and fetus,which increases the risk of brain damage in the fetal stage.展开更多
Based on digital land use data from 1995 to 2000 and road data, the land use and landscape changes of Golmud, Qumaleb and Zhidoi are studied on a macro-scale. Land use and landscape changes in highway buffer zones and...Based on digital land use data from 1995 to 2000 and road data, the land use and landscape changes of Golmud, Qumaleb and Zhidoi are studied on a macro-scale. Land use and landscape changes in highway buffer zones and city expansion are special subjects. A new formula is used to define the exact degree of dynamic land use. To adequately define land use and landscape pattern changes, the buffer zones, illustrating the changes at different distances from the road, are recognized with ArcGIS 8.1 software. Prominent changes took place in land use and landscape patterns from 1995 to 2000, and the area of built-up land increased by 323.8%. The comprehensive degree of dynamic land use is 2.25, and the degree of dynamic land use of built-up land is the highest, followed by cultivated land. Woodland has the lowest value. The used degree index of land resources declined by 38.8 from 1995 to 2000. Landscape changed dramatically which influenced ecological processes immensely. Different from the corridor effect of other traffic routes, the corridor effect of this section of road is not obvious and its “point” radiation effect can be easily seen. The expanding range of Golmud City is confined to a 3 km buffer, while for Wudaoliang, it is 1 km. No land use change happened in the Nanshankou buffer.展开更多
This paper reports a study of complex focussing acoustic fields of a convex phased array probe widely used in ultrasonic diagnostic B-scanner. The time delay necessary for electronic focussing and for geometric focuss...This paper reports a study of complex focussing acoustic fields of a convex phased array probe widely used in ultrasonic diagnostic B-scanner. The time delay necessary for electronic focussing and for geometric focussing of complex focussing is given. By means of Helmholtz's integral formula, the expressions of acoustic fields were obtained for the electronic focussing and complex focussing.With Simpson's numerical integral, a great deal of computations was carried out with an 86 / 330 computer. By means of using different parameters, an optimum focal range and beam width of a 4 sequences electronic and complex focussing acoustic system was selected. With an EUB-40 ultrasound diagnostic B-scanner produced by the Hitachi company, the lateral focussing acoustic field and lateral resolution in an echoic tank were photographed by latticing method and the experimental result is consistent with the theory.展开更多
Objective To compare the diagnostic efficiency of the thyroid imaging reporting and data system(TIRADS),the Bethesda system for reporting thyroid cytopathology(BSRTC)and BRAFV600Edetection,and their combined use in th...Objective To compare the diagnostic efficiency of the thyroid imaging reporting and data system(TIRADS),the Bethesda system for reporting thyroid cytopathology(BSRTC)and BRAFV600Edetection,and their combined use in the differentiation between benign and malignant thyroid nodules.Methods One hundred展开更多
基金sponsored by the Young Scholar Scientific Research Foundation of the National Institute of Nutrition and Health of China CDC[Grant No:NINH2016001]
文摘Iodine is an element that is essential for the synthesis of thyroid hormones.Adequate intake of dietary iodine has been recognized as a critical factor for maintaining health.It is a well-known fact that iodine deficiency can impede the production of thyroid hormones in both the mother and fetus,which increases the risk of brain damage in the fetal stage.
基金The National Key Basic Research Special Fund, No.Gl 998040800 The Core Project of Institute of Geographic Sciences and Natural Resources Research of CAS for Knowledge Innovation, No. CXIOG-E01-01,No.CXIOG-A00-03-02.
文摘Based on digital land use data from 1995 to 2000 and road data, the land use and landscape changes of Golmud, Qumaleb and Zhidoi are studied on a macro-scale. Land use and landscape changes in highway buffer zones and city expansion are special subjects. A new formula is used to define the exact degree of dynamic land use. To adequately define land use and landscape pattern changes, the buffer zones, illustrating the changes at different distances from the road, are recognized with ArcGIS 8.1 software. Prominent changes took place in land use and landscape patterns from 1995 to 2000, and the area of built-up land increased by 323.8%. The comprehensive degree of dynamic land use is 2.25, and the degree of dynamic land use of built-up land is the highest, followed by cultivated land. Woodland has the lowest value. The used degree index of land resources declined by 38.8 from 1995 to 2000. Landscape changed dramatically which influenced ecological processes immensely. Different from the corridor effect of other traffic routes, the corridor effect of this section of road is not obvious and its “point” radiation effect can be easily seen. The expanding range of Golmud City is confined to a 3 km buffer, while for Wudaoliang, it is 1 km. No land use change happened in the Nanshankou buffer.
文摘This paper reports a study of complex focussing acoustic fields of a convex phased array probe widely used in ultrasonic diagnostic B-scanner. The time delay necessary for electronic focussing and for geometric focussing of complex focussing is given. By means of Helmholtz's integral formula, the expressions of acoustic fields were obtained for the electronic focussing and complex focussing.With Simpson's numerical integral, a great deal of computations was carried out with an 86 / 330 computer. By means of using different parameters, an optimum focal range and beam width of a 4 sequences electronic and complex focussing acoustic system was selected. With an EUB-40 ultrasound diagnostic B-scanner produced by the Hitachi company, the lateral focussing acoustic field and lateral resolution in an echoic tank were photographed by latticing method and the experimental result is consistent with the theory.
文摘Objective To compare the diagnostic efficiency of the thyroid imaging reporting and data system(TIRADS),the Bethesda system for reporting thyroid cytopathology(BSRTC)and BRAFV600Edetection,and their combined use in the differentiation between benign and malignant thyroid nodules.Methods One hundred
