Objective： To investigate the possible age- and sex-related differences in the various dimensions of corpus callosum among Chinese normal adults. Methods： Magnetic resonance images of 286 healthy adults, including 1...Objective： To investigate the possible age- and sex-related differences in the various dimensions of corpus callosum among Chinese normal adults. Methods： Magnetic resonance images of 286 healthy adults, including 127 males and 159 females, and ranging in age from 20 to 81 years, were investigated. They were classified into 5 age groups （ 20-29, 30-39, 40-49, 50-59, and 60-81 years old）. Corresponding to the age group sequence above, the male/female ratio of each group respectively was： 25/26, 26/33, 33/50, 32/36, and 11/14. The following dimensions of corpus callosum were systematically measured on the midsagittal Tl-weighted images： frontal to occipital pole （represented as line segment AB）, total longitudinal dimension of the corpus callosum （CD）, the maximum height （EF）, the widths of the genu （CX）, anterior one third （GH）, central region （EZ）, posterior one third （MN） and splenium （YD）. After that, the obtained data was analyzed statistically. Results： （1） The total longitudinal dimension, maximum height, widths of the genu, central region and splenium were proved to be larger in females. But the widths of the anterior one third and posterior one third were similar in-between. In spite of that, a conspicuous sex-related difference was not found. （2） The total longitudinal dimension and the maximum height of the corpus callosum remained stable in all age subgroups. Yet the widths of the genu, anterior one third, central region, posterior one third and splenium had a tendency of decreasing gradually with aging. Statistical difference was seen in the anterior one third, central region, posterior one third （P〈0.05）. Conclusion： There is no sex-related difference in all dimensions of corpus callosum. But, with aging, a significant difference is found in the widths of the anterior one third, central region and posterior one third.展开更多
In the field of functional MRI,compared to observations of task-related brain activity,a growing number of studies have shown that spontaneous brain activity during the resting state may be more sensitive to defects i...In the field of functional MRI,compared to observations of task-related brain activity,a growing number of studies have shown that spontaneous brain activity during the resting state may be more sensitive to defects in the cognitive functions of our brain.展开更多
In vertebrates,body weight increases many folds as a consequence of body growth from the childhood to adulthood（e.g.,～20 folds for a mouse）.Considering the fact that the liver-to-body weight ratio（LBR）stays relat...In vertebrates,body weight increases many folds as a consequence of body growth from the childhood to adulthood（e.g.,～20 folds for a mouse）.Considering the fact that the liver-to-body weight ratio（LBR）stays relatively constant within species（Weglarz and Sandgren,2000;Kan et al.,2009）,the cell number in a liver must therefore keep increasing along with the growth of an individual organism. For example, during the growth of the zebrafish from 5 days post-fertilization （dpf） to 1.5 years old, the number of liver cells increased -900 folds （Figs. 1A and S1 ）.展开更多
文摘Objective： To investigate the possible age- and sex-related differences in the various dimensions of corpus callosum among Chinese normal adults. Methods： Magnetic resonance images of 286 healthy adults, including 127 males and 159 females, and ranging in age from 20 to 81 years, were investigated. They were classified into 5 age groups （ 20-29, 30-39, 40-49, 50-59, and 60-81 years old）. Corresponding to the age group sequence above, the male/female ratio of each group respectively was： 25/26, 26/33, 33/50, 32/36, and 11/14. The following dimensions of corpus callosum were systematically measured on the midsagittal Tl-weighted images： frontal to occipital pole （represented as line segment AB）, total longitudinal dimension of the corpus callosum （CD）, the maximum height （EF）, the widths of the genu （CX）, anterior one third （GH）, central region （EZ）, posterior one third （MN） and splenium （YD）. After that, the obtained data was analyzed statistically. Results： （1） The total longitudinal dimension, maximum height, widths of the genu, central region and splenium were proved to be larger in females. But the widths of the anterior one third and posterior one third were similar in-between. In spite of that, a conspicuous sex-related difference was not found. （2） The total longitudinal dimension and the maximum height of the corpus callosum remained stable in all age subgroups. Yet the widths of the genu, anterior one third, central region, posterior one third and splenium had a tendency of decreasing gradually with aging. Statistical difference was seen in the anterior one third, central region, posterior one third （P〈0.05）. Conclusion： There is no sex-related difference in all dimensions of corpus callosum. But, with aging, a significant difference is found in the widths of the anterior one third, central region and posterior one third.
文摘In the field of functional MRI,compared to observations of task-related brain activity,a growing number of studies have shown that spontaneous brain activity during the resting state may be more sensitive to defects in the cognitive functions of our brain.
基金financially supported by the grants from the National Natural Science Foundation of China(No.31330050)the National Basic Research Program of China(2015CB942802 and2017YFA0504501)
文摘In vertebrates,body weight increases many folds as a consequence of body growth from the childhood to adulthood（e.g.,～20 folds for a mouse）.Considering the fact that the liver-to-body weight ratio（LBR）stays relatively constant within species（Weglarz and Sandgren,2000;Kan et al.,2009）,the cell number in a liver must therefore keep increasing along with the growth of an individual organism. For example, during the growth of the zebrafish from 5 days post-fertilization （dpf） to 1.5 years old, the number of liver cells increased -900 folds （Figs. 1A and S1 ）.
