Mesenchymal stromal cells (MSCs) can be obtained from several sources and the significant differences in their properties make it crucial to investigate the differentiation potential of MSCs from different sources to ...Mesenchymal stromal cells (MSCs) can be obtained from several sources and the significant differences in their properties make it crucial to investigate the differentiation potential of MSCs from different sources to determine the optimal source of MSCs. We investigated if this biological heterogeneity in MSCs from different sources results in different mechanisms for their differentiation. In this study, we compared the gene expression patterns of phenotypically defined MSCs derived from three ontogenically different sources: Embryonic stem cells (hES-MSCs), Fetal limb (Flb-MSCs) and Bone Marrow (BM-MSCs). Differentially expressed genes between differentiated cells and undifferentiated controls were compared across the three MSC sources. We found minimal overlap (5% - 16%) in differentially expressed gene sets among the three sources. Flb-MSCs were similar to BM-MSCs based on differential gene expression patterns. Pathway analysis of the differentially expressed genes using Ingenuity Pathway Analysis (IPA) revealed a large variation in the canonical pathways leading to MSC differentiation. The similar canonical pathways among the three sources were lineage specific. The Flb-MSCs showed maximum overlap of canonical pathways with the BM-MSCs, indicating that the Flb-MSCs are an intermediate source between the less specialised hES-MSC source and the more specialised BM-MSC source. The source specific pathways prove that MSCs from the three ontogenically different sources use different biological pathways to obtain similar differentiation outcomes. Thus our study advocates the understanding of biological pathways to obtain optimal sources of MSCs for various clinical applications.展开更多
When studying song organizations of chaffinch (Fringilla coelebs L.), we find the unique typological parities (ratio) of songs in different local populations of a species-specific area. The degree of prevalence of dif...When studying song organizations of chaffinch (Fringilla coelebs L.), we find the unique typological parities (ratio) of songs in different local populations of a species-specific area. The degree of prevalence of different chaffinch song types can’t correspond to percentage proceeding from their general (common) number in a population. Thus different areas of Russia are forming original (different) song cultures of chaffinch, consisting of the certain set and a parity (ratio) of song types, frequently including the so-called dialect song forms, that have been observed. The complex interrelation of geographical variability and structural variability of chaffinch song in many respects gives a support in an evolutionary view from the given aspect.展开更多
The pore structures and controlling factors of several different Paleozoic shales from Southern China and their kerogens were studied using nitrogen adsorption and scanning electron microscopy methods. The results ind...The pore structures and controlling factors of several different Paleozoic shales from Southern China and their kerogens were studied using nitrogen adsorption and scanning electron microscopy methods. The results indicate that: 1) The specific surface area is 2.22–3.52 m2/g and has no correlation with the TOC content of the Permian Dalong Formation shales, nanopores are extremely undeveloped in the Dalong Formation kerogens, which have specific surface areas of 20.35–27.49 m2/g; 2) the specific surface area of the Silurian Longmaxi Formation shales is in the range of 17.83–29.49 m2/g and is positively correlated with TOC content, the kerogens from the Longmaxi Formation have well-developed nanopores, with round or elliptical shapes, and the specific surface areas of these kerogens are as high as 279.84–300.3 m2/g; 3) for the Niutitang Formation shales, the specific surface area is 20.12–29.49 m2/grock and increases significantly with increasing TOC and smectite content. The Niutitang Formation kerogens develop a certain amount of nanopores with a specific surface area of 161.2 m2/g. Oil shale was also examined for comparison, and was found to have a specific surface area of 19.99 m2/g. Nanopores are rare in the Youganwo Formation kerogen, which has a specific surface area of only 5.54 m2/g, suggesting that the specific surface area of oil shale is due mainly to the presence of smectite and other clay minerals. The specific surface area and the number of pores present in shales are closely related to TOC, kerogen type and maturity, smectite content, and other factors. Low-maturity kerogen has very few nanopores and therefore has a very low specific surface area, whereas nanopores are abundant in mature to over- mature kerogen, leading to high specific surface areas. The Longmaxi Formation kerogen has more developed nanopores and a higher specific surface area than the Niutitang Formation kerogen, which may be due to differences in the kerogen type and maceral components. A high content of smectite may also contribute to shale surface area. The pore volume and specific surface area of low-maturity kerogens are mainly attributable to pores with diameters above 10 nm. By contrast, the pore volume of mature kerogens consists predominantly of pores with diameters above 10 nm with some contribution from about 4 nm diameter pores, while the specific surface area is due mainly to pores with diameters of less than 4 nm. Through a comparative study of the specific surface area and pore structure characteristics of different shales and their kerogens, we conclude that the Longmaxi Formation shales and Niutitang Formation shales have greater sorption capacities than the Dalong Formation shales.展开更多
为解决传统印刷品图像配准算法精度和速度不能兼得的问题,本文提出了一种基于外轮廓与霍夫变换的印刷品图像配准算法。该算法先对图像进行灰度化、去噪、对比度增强、图像分割完成图像预处理;根据图像分割结果获得印刷区域的外轮廓,计...为解决传统印刷品图像配准算法精度和速度不能兼得的问题,本文提出了一种基于外轮廓与霍夫变换的印刷品图像配准算法。该算法先对图像进行灰度化、去噪、对比度增强、图像分割完成图像预处理;根据图像分割结果获得印刷区域的外轮廓,计算外轮廓形心坐标,得到偏移量,再根据轮廓计算出旋转量;根据偏移量和旋转量对待配准图像进行刚性变换和双线性插值完成图像粗配准;在感兴趣区域(Region of interest,ROI)中限制霍夫变换的动态参数,计算出ROI中的直线,根据直线交点得到3个坐标,根据3个坐标对待配准图像进行仿射变换和双线性插值,完成图像精配准。实验验证表明,本算法配准结果的平均NNC系数达到0.903264,平均配准时间为256.91。展开更多
文摘Mesenchymal stromal cells (MSCs) can be obtained from several sources and the significant differences in their properties make it crucial to investigate the differentiation potential of MSCs from different sources to determine the optimal source of MSCs. We investigated if this biological heterogeneity in MSCs from different sources results in different mechanisms for their differentiation. In this study, we compared the gene expression patterns of phenotypically defined MSCs derived from three ontogenically different sources: Embryonic stem cells (hES-MSCs), Fetal limb (Flb-MSCs) and Bone Marrow (BM-MSCs). Differentially expressed genes between differentiated cells and undifferentiated controls were compared across the three MSC sources. We found minimal overlap (5% - 16%) in differentially expressed gene sets among the three sources. Flb-MSCs were similar to BM-MSCs based on differential gene expression patterns. Pathway analysis of the differentially expressed genes using Ingenuity Pathway Analysis (IPA) revealed a large variation in the canonical pathways leading to MSC differentiation. The similar canonical pathways among the three sources were lineage specific. The Flb-MSCs showed maximum overlap of canonical pathways with the BM-MSCs, indicating that the Flb-MSCs are an intermediate source between the less specialised hES-MSC source and the more specialised BM-MSC source. The source specific pathways prove that MSCs from the three ontogenically different sources use different biological pathways to obtain similar differentiation outcomes. Thus our study advocates the understanding of biological pathways to obtain optimal sources of MSCs for various clinical applications.
文摘When studying song organizations of chaffinch (Fringilla coelebs L.), we find the unique typological parities (ratio) of songs in different local populations of a species-specific area. The degree of prevalence of different chaffinch song types can’t correspond to percentage proceeding from their general (common) number in a population. Thus different areas of Russia are forming original (different) song cultures of chaffinch, consisting of the certain set and a parity (ratio) of song types, frequently including the so-called dialect song forms, that have been observed. The complex interrelation of geographical variability and structural variability of chaffinch song in many respects gives a support in an evolutionary view from the given aspect.
基金supported by National Basic Research Program of China(Grant No.2012CB214704)Major National Science and Techno-logy Project(Grant No.2011ZX05008-002-20)National Natural Science Foundation of China(Grant No.4123058)
文摘The pore structures and controlling factors of several different Paleozoic shales from Southern China and their kerogens were studied using nitrogen adsorption and scanning electron microscopy methods. The results indicate that: 1) The specific surface area is 2.22–3.52 m2/g and has no correlation with the TOC content of the Permian Dalong Formation shales, nanopores are extremely undeveloped in the Dalong Formation kerogens, which have specific surface areas of 20.35–27.49 m2/g; 2) the specific surface area of the Silurian Longmaxi Formation shales is in the range of 17.83–29.49 m2/g and is positively correlated with TOC content, the kerogens from the Longmaxi Formation have well-developed nanopores, with round or elliptical shapes, and the specific surface areas of these kerogens are as high as 279.84–300.3 m2/g; 3) for the Niutitang Formation shales, the specific surface area is 20.12–29.49 m2/grock and increases significantly with increasing TOC and smectite content. The Niutitang Formation kerogens develop a certain amount of nanopores with a specific surface area of 161.2 m2/g. Oil shale was also examined for comparison, and was found to have a specific surface area of 19.99 m2/g. Nanopores are rare in the Youganwo Formation kerogen, which has a specific surface area of only 5.54 m2/g, suggesting that the specific surface area of oil shale is due mainly to the presence of smectite and other clay minerals. The specific surface area and the number of pores present in shales are closely related to TOC, kerogen type and maturity, smectite content, and other factors. Low-maturity kerogen has very few nanopores and therefore has a very low specific surface area, whereas nanopores are abundant in mature to over- mature kerogen, leading to high specific surface areas. The Longmaxi Formation kerogen has more developed nanopores and a higher specific surface area than the Niutitang Formation kerogen, which may be due to differences in the kerogen type and maceral components. A high content of smectite may also contribute to shale surface area. The pore volume and specific surface area of low-maturity kerogens are mainly attributable to pores with diameters above 10 nm. By contrast, the pore volume of mature kerogens consists predominantly of pores with diameters above 10 nm with some contribution from about 4 nm diameter pores, while the specific surface area is due mainly to pores with diameters of less than 4 nm. Through a comparative study of the specific surface area and pore structure characteristics of different shales and their kerogens, we conclude that the Longmaxi Formation shales and Niutitang Formation shales have greater sorption capacities than the Dalong Formation shales.
文摘为解决传统印刷品图像配准算法精度和速度不能兼得的问题,本文提出了一种基于外轮廓与霍夫变换的印刷品图像配准算法。该算法先对图像进行灰度化、去噪、对比度增强、图像分割完成图像预处理;根据图像分割结果获得印刷区域的外轮廓,计算外轮廓形心坐标,得到偏移量,再根据轮廓计算出旋转量;根据偏移量和旋转量对待配准图像进行刚性变换和双线性插值完成图像粗配准;在感兴趣区域(Region of interest,ROI)中限制霍夫变换的动态参数,计算出ROI中的直线,根据直线交点得到3个坐标,根据3个坐标对待配准图像进行仿射变换和双线性插值,完成图像精配准。实验验证表明,本算法配准结果的平均NNC系数达到0.903264,平均配准时间为256.91。
