The dynamic changes of nucleolar ultrastructure in the cell cycle of Physarum polycephalum Schw. were studied by an en bloc silver-staining method. The results showed that the nucleolus was large in size and situated ...The dynamic changes of nucleolar ultrastructure in the cell cycle of Physarum polycephalum Schw. were studied by an en bloc silver-staining method. The results showed that the nucleolus was large in size and situated in the center of the nucleus in late G(2)-phase, and the fibrillar centers, dense fibrillar components and granular components could be observed in the nucleolus. During prophase, the nucleolus moved towards the periphery of the nucleus and in late prophase disintegrated near the nuclear envelope. in metaphase, the disintegrated nucleolar components were dispersed in masses and located at the periphery of the chromosomal region of the nucleus. No specifically silver-stained area and argentophilic protein sheath were observed on the chromosomes, but there were some big dispersed silver particles within the chromosomes. During telophase the nucleolar components moved towards the two poles along with the chromosomes and co-existed with the decondensing chromatin in daughter nuclei. The nucleolar components then gradually converged with one another and separated from the chromatin. A big nucleolus was formed in the nucleus about 120 min after the completion of mitosis.展开更多
A novel gold-label silver-stain electrochemical immunosensor was developed based on polythioninegold nanoparticles（PTh-Au） modified glassy carbon electrode（GCE） as a platform and secondary antibody labeled Au NPs...A novel gold-label silver-stain electrochemical immunosensor was developed based on polythioninegold nanoparticles（PTh-Au） modified glassy carbon electrode（GCE） as a platform and secondary antibody labeled Au NPs（Ab;-Au） as immumoprobe for carcinoembryonic antigen（CEA） detection. The sandwich-type biosensor adopted anodic stripping voltammetry to detect silver stripping signal when the Ab;-Au of the formed immunocomplexes were stained with silver. The optimized detection conditions were investigated. The effect of different electrochemical responses at various concentrations of CEA was checked by anodic stripping voltammetry. This immunosensor showed a low detection limit of 0.055 ng/mL and a wide linear calibration of 0.1-120 ng/mL（R;=0.99856）. Moreover, this immunoassay also existed the advantages of good reproducibility, stability and selectivity. Thus, this immunosensing protocol may provide a potential application for effective clinical detection of CEA.展开更多
Poly（tetrafluoroethylene） （PTFE） was treated with plasma in a mixture of nitrogen and hydrogen （1 ： 2 in volume）. X-ray photoelectron spectroscopy （XPS） demonstrated the success of amino group grafting. The a...Poly（tetrafluoroethylene） （PTFE） was treated with plasma in a mixture of nitrogen and hydrogen （1 ： 2 in volume）. X-ray photoelectron spectroscopy （XPS） demonstrated the success of amino group grafting. The as-treated PTFE slices were successively applied to the in situ synthesis of oligonucleotides. With the detection of gold-label-silver-stain, the hybridization signals were recorded with a gel document and analysis system. A target DNA concentration as low as 10 pmol/L could be detected. The complementary and mismatched sequences were distinguished clearly, and the ratio of background-subtracted gray scale values for perfect match ： 1 base mismatch ： 2 base mismatch ： 3 base mismatch was 72 ： 44.4 ： 22.5 ： 11.4. The sensitivity of in situ synthesis system was 1 order of magnitude higher than that of spotting system, and the signal of the former was about 1.5 times stronger than that of the latter under the same target DNA concentration. These plasma modified PTFE slices might open novel prospects for the in situ synthesis of DNA micro-arrays.展开更多
文摘The dynamic changes of nucleolar ultrastructure in the cell cycle of Physarum polycephalum Schw. were studied by an en bloc silver-staining method. The results showed that the nucleolus was large in size and situated in the center of the nucleus in late G(2)-phase, and the fibrillar centers, dense fibrillar components and granular components could be observed in the nucleolus. During prophase, the nucleolus moved towards the periphery of the nucleus and in late prophase disintegrated near the nuclear envelope. in metaphase, the disintegrated nucleolar components were dispersed in masses and located at the periphery of the chromosomal region of the nucleus. No specifically silver-stained area and argentophilic protein sheath were observed on the chromosomes, but there were some big dispersed silver particles within the chromosomes. During telophase the nucleolar components moved towards the two poles along with the chromosomes and co-existed with the decondensing chromatin in daughter nuclei. The nucleolar components then gradually converged with one another and separated from the chromatin. A big nucleolus was formed in the nucleus about 120 min after the completion of mitosis.
基金financial supports of the National Natural Science Foundation of China(Nos.61471168,61571187)China Postdoctoral Science Foundation(No.2016T90403)+2 种基金Postdoctoral Science Foundation of Jiangsu Province(No.1601021A)the Natural Science Foundation of Hunan Province(No.2017JJ209)Hunan Key Research Project(No.2017SK2174)
文摘A novel gold-label silver-stain electrochemical immunosensor was developed based on polythioninegold nanoparticles（PTh-Au） modified glassy carbon electrode（GCE） as a platform and secondary antibody labeled Au NPs（Ab;-Au） as immumoprobe for carcinoembryonic antigen（CEA） detection. The sandwich-type biosensor adopted anodic stripping voltammetry to detect silver stripping signal when the Ab;-Au of the formed immunocomplexes were stained with silver. The optimized detection conditions were investigated. The effect of different electrochemical responses at various concentrations of CEA was checked by anodic stripping voltammetry. This immunosensor showed a low detection limit of 0.055 ng/mL and a wide linear calibration of 0.1-120 ng/mL（R;=0.99856）. Moreover, this immunoassay also existed the advantages of good reproducibility, stability and selectivity. Thus, this immunosensing protocol may provide a potential application for effective clinical detection of CEA.
基金Project supported by Hunan Province Natural Science Foundation （No. 04jj40023）, the Trans-century Training Program Foundation for the Talents by the Ministry of Education of China, and the Post-doctoral Science Foundation of China.
文摘Poly（tetrafluoroethylene） （PTFE） was treated with plasma in a mixture of nitrogen and hydrogen （1 ： 2 in volume）. X-ray photoelectron spectroscopy （XPS） demonstrated the success of amino group grafting. The as-treated PTFE slices were successively applied to the in situ synthesis of oligonucleotides. With the detection of gold-label-silver-stain, the hybridization signals were recorded with a gel document and analysis system. A target DNA concentration as low as 10 pmol/L could be detected. The complementary and mismatched sequences were distinguished clearly, and the ratio of background-subtracted gray scale values for perfect match ： 1 base mismatch ： 2 base mismatch ： 3 base mismatch was 72 ： 44.4 ： 22.5 ： 11.4. The sensitivity of in situ synthesis system was 1 order of magnitude higher than that of spotting system, and the signal of the former was about 1.5 times stronger than that of the latter under the same target DNA concentration. These plasma modified PTFE slices might open novel prospects for the in situ synthesis of DNA micro-arrays.
