The metabolic way of calcium ions which was released due to in vivo degradation of porous β TCP ceramics was studied by using the radioisotope 45 Ca as tracer. The result shows that some of the calcium ions enter blo...The metabolic way of calcium ions which was released due to in vivo degradation of porous β TCP ceramics was studied by using the radioisotope 45 Ca as tracer. The result shows that some of the calcium ions enter blood and take part in the circulation. These calcium ions distribute into organs and tissues (such as liver, kidney, brain, heart, lung, spleen and stomach) and participate in the metabolisms of body. There is neither the accumulation of calcium ions, nor the lesion or pathologic calcification of the organs and tissues. Some of the calcium ions that enter the near end femur, ulna and skull are reused by bony tissue to take part in both local mineralization processes during bone healing, or are stored in calcium pool which can participate in the whole body circulating. In the cyclical process, other calcium ions are excreted with urine and feces through kidney and liver. It is indicated that the degradation products of β TCP ceramics can take part in the physiological metabolic process of normal bone and tissue.展开更多
CRISPR/Cas系统是细菌和古生菌的自适应免疫系统,其对基因组高效精准的编辑,极大地推动了发育生物学、表观遗传学、药物开发、疾病治疗等多个学科和研究领域的发展.CRISPR/Cas9系统诱导基因组DNA产生双链断裂,以非同源末端连接(non-homo...CRISPR/Cas系统是细菌和古生菌的自适应免疫系统,其对基因组高效精准的编辑,极大地推动了发育生物学、表观遗传学、药物开发、疾病治疗等多个学科和研究领域的发展.CRISPR/Cas9系统诱导基因组DNA产生双链断裂,以非同源末端连接(non-homologous end joining,NHEJ)的方式进行修复,因此会在剪切位置随机地引入短的插入和删除(insertions and deletions,indels).这些引入的indels作为区分细胞的标签,被称为条形码.细胞条形码技术已经被用于谱系追踪、基因组功能筛选等.而测序技术的飞速发展和成本的大幅度降低以及单细胞转录组测序技术的出现,可以在时间和空间层面同时对数百万个单细胞进行谱系追踪,记录细胞活动.本综述讨论了CRISPR/Cas系统的工作原理、细胞条形码技术和单细胞测序技术(scRNA-seq),以及两者结合产生的单细胞谱系追踪技术.展开更多
The determination of trace element Pb in electrolyte MnSO_4H_2SO_4 was studied with differential pulse po-larography. The trace Pb was originated from new type Pb-Ag-Ca alloy anode being used in preduction processof e...The determination of trace element Pb in electrolyte MnSO_4H_2SO_4 was studied with differential pulse po-larography. The trace Pb was originated from new type Pb-Ag-Ca alloy anode being used in preduction processof electrolytic MnO_2 (EMD). The KCl was added as background of electrolyte. The differential pulse polarco-gram obtained for Pb(Ⅱ) is well in peak contour and is easy to determination. The peak potential is -0. 44 V(vs Ag-AgCl potential , experimental valuel). The Pb content may be determined by standard addition methodwhich is simple , reliable and fast. This study presents some foundamental data for Pb-Ag-Ca anode (abbreviated to PAC anede). The consuming rate for PAC anode is evaluated as 4. 82% annually.展开更多
On orbital timescales,stable oxygen isotope(δ^(18)O)records from stalagmites in Central China and East Asian summer monsoon(EASM)intensity/precipitation amount records reconstructed from loess-paleosol sequences in N...On orbital timescales,stable oxygen isotope(δ^(18)O)records from stalagmites in Central China and East Asian summer monsoon(EASM)intensity/precipitation amount records reconstructed from loess-paleosol sequences in North China,have been suggested to show different change patterns.Here,high-resolution trace element/Ca ratios(Mg/Ca,Sr/Ca,Ba/Ca,Al/Ca,P/Ca)of stalagmite PS1 from Zhenzhu(ZZ)cave in North China over the past 130 kyr have been reconstructed.Based on two years of monitoring results from ZZ cave and the relationships among trace element/Ca ratios,it is demonstrated that the PS1 Mg/Ca could be a robust indicator of local effective precipitation.The Mg/Ca andδ^(13)C records of stalagmite PS1 exhibit highly in-phase co-variations on multi-millennial to orbital timescales and consistent long-term trends over the past 130 kyr,which is supported by the loess-based EASM precipitation amount records from the western Chinese Loess Plateau.These similarities indicate that effective precipitation of the ZZ cave area is mainly controlled by EASM precipitation amount in North China,and also support the long-term variation trend of the EASM precipitation amount,that is,decreasing from marine isotope stage(MIS)5e–MIS5c–MIS5a–MIS3,followed by an increase to MIS1.This long-term variation trend of EASM precipitation amount in North China over the past 130 kyr is primarily driven by solar insolation and global ice volume.These results confirm that proxies with the same indicative significance from both stalagmites and loess-paleosol profiles within the same region(such as North China)can corroborate each other.展开更多
文摘The metabolic way of calcium ions which was released due to in vivo degradation of porous β TCP ceramics was studied by using the radioisotope 45 Ca as tracer. The result shows that some of the calcium ions enter blood and take part in the circulation. These calcium ions distribute into organs and tissues (such as liver, kidney, brain, heart, lung, spleen and stomach) and participate in the metabolisms of body. There is neither the accumulation of calcium ions, nor the lesion or pathologic calcification of the organs and tissues. Some of the calcium ions that enter the near end femur, ulna and skull are reused by bony tissue to take part in both local mineralization processes during bone healing, or are stored in calcium pool which can participate in the whole body circulating. In the cyclical process, other calcium ions are excreted with urine and feces through kidney and liver. It is indicated that the degradation products of β TCP ceramics can take part in the physiological metabolic process of normal bone and tissue.
基金动物重要基因克隆及功能验证(2016ZX08009-003-006)The 111 Project(Project Grant No.B12008)
文摘CRISPR/Cas系统是细菌和古生菌的自适应免疫系统,其对基因组高效精准的编辑,极大地推动了发育生物学、表观遗传学、药物开发、疾病治疗等多个学科和研究领域的发展.CRISPR/Cas9系统诱导基因组DNA产生双链断裂,以非同源末端连接(non-homologous end joining,NHEJ)的方式进行修复,因此会在剪切位置随机地引入短的插入和删除(insertions and deletions,indels).这些引入的indels作为区分细胞的标签,被称为条形码.细胞条形码技术已经被用于谱系追踪、基因组功能筛选等.而测序技术的飞速发展和成本的大幅度降低以及单细胞转录组测序技术的出现,可以在时间和空间层面同时对数百万个单细胞进行谱系追踪,记录细胞活动.本综述讨论了CRISPR/Cas系统的工作原理、细胞条形码技术和单细胞测序技术(scRNA-seq),以及两者结合产生的单细胞谱系追踪技术.
文摘The determination of trace element Pb in electrolyte MnSO_4H_2SO_4 was studied with differential pulse po-larography. The trace Pb was originated from new type Pb-Ag-Ca alloy anode being used in preduction processof electrolytic MnO_2 (EMD). The KCl was added as background of electrolyte. The differential pulse polarco-gram obtained for Pb(Ⅱ) is well in peak contour and is easy to determination. The peak potential is -0. 44 V(vs Ag-AgCl potential , experimental valuel). The Pb content may be determined by standard addition methodwhich is simple , reliable and fast. This study presents some foundamental data for Pb-Ag-Ca anode (abbreviated to PAC anede). The consuming rate for PAC anode is evaluated as 4. 82% annually.
基金supported by the National Natural Science Foundation of China(Grant Nos.42371164,42001080&42171156)the Science and Technology Innovation Program of Hunan Province(Grant No.2023RC3130)the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province。
文摘On orbital timescales,stable oxygen isotope(δ^(18)O)records from stalagmites in Central China and East Asian summer monsoon(EASM)intensity/precipitation amount records reconstructed from loess-paleosol sequences in North China,have been suggested to show different change patterns.Here,high-resolution trace element/Ca ratios(Mg/Ca,Sr/Ca,Ba/Ca,Al/Ca,P/Ca)of stalagmite PS1 from Zhenzhu(ZZ)cave in North China over the past 130 kyr have been reconstructed.Based on two years of monitoring results from ZZ cave and the relationships among trace element/Ca ratios,it is demonstrated that the PS1 Mg/Ca could be a robust indicator of local effective precipitation.The Mg/Ca andδ^(13)C records of stalagmite PS1 exhibit highly in-phase co-variations on multi-millennial to orbital timescales and consistent long-term trends over the past 130 kyr,which is supported by the loess-based EASM precipitation amount records from the western Chinese Loess Plateau.These similarities indicate that effective precipitation of the ZZ cave area is mainly controlled by EASM precipitation amount in North China,and also support the long-term variation trend of the EASM precipitation amount,that is,decreasing from marine isotope stage(MIS)5e–MIS5c–MIS5a–MIS3,followed by an increase to MIS1.This long-term variation trend of EASM precipitation amount in North China over the past 130 kyr is primarily driven by solar insolation and global ice volume.These results confirm that proxies with the same indicative significance from both stalagmites and loess-paleosol profiles within the same region(such as North China)can corroborate each other.
