ABSTRACT. Gap junction intercellular communication (GJIC) plays a fundamental role in mediating intercellular signals and coordinating multicellular behavior in various tissues and organs. Glomerular mesangial cells (MC) are rich in GJ, but the functional associations of these intercellular channels are still unclear. This study examines the potential role of GJ in the transmission of intercellular Ca2+ signals and in the coordination of MC contraction. First, the presence of GJ protein Cx43 and functional GJIC was confirmed in MC by using immunochemical staining or transfer of Lucifer yellow (LY) after a single cell injection, respectively. Second, mechanical stimulation of a single MC initiated propagation of an intercellular Ca2+ wave, which was preventable by the GJ inhibitor heptanol but was not altered by pretreatment of MC with ATP or addition of apyrase into the assay system. Third, the phospholipase C (PLC) inhibitor U73122 could largely eliminate the mechanically elicited propagation of intercellular Ca2+ waves, suggesting a possibly mediating role of inositol trisphosphate (IP3) in the initiation and transmission of intercellular Ca2+ signaling. Fourth, injection of IP3 into a single cell caused contraction, not only in the targeted cell, but also in the adjacent cells, as indicated by the reduction of cellular planar area. Fifth, addition of two structurally unrelated GJ inhibitors, heptanol and α-glycyrrhetinic acid (GA), into MC embedded in collagen gels significantly attenuated the reduction of gel areas after exposure to serum. This study provides the first functional evidence supporting the critical role of GJIC in the synchronization of MC behaviors.
Objective To investigate the cognition of nurses with different education degrees about the mercury leak of a broken bar glass thermometer.Methods 120 nurses with different degrees were investigated by self-designed questionnaires of their whole cognition about processing mercury leak,basic knowledge of mercury,hazards of mercury and methods after mercury leak.Results The score of 120 nurses'overall cognition about mercury leak was (37.53 ± 8.89),in which nurses of secondary education scored (42.63 ±9.15),nurses of junior college scored (30.43 t4.47),undergraduate nurses scored (40.15±7.33),and the difference was statistically significant (H =54.094,P ＜ 0.01).There was no statistically significant difference of cognition about mercury knowledge between nurses with different degrees (P ＞ 0.05),while there was statistically significant difference of cognition about methods after mercury leak (P ＜ 0.01).Basis knowledge of mercury included 5 items,scores of which were relatively higher in all nurses (2.91 ±0.11),and nurses of secondary education scored the lowest,nurses of junior college were in the middle and undergraduate nurses were the highest.All nurses scored 3 about was a kind of poisonous heavy mental,indicating that nurses of all degrees were very familiar with it.Hazards of mercury included 6 items,all with lower scores,in which nurses of secondary education scored the highest,nurses of junior college were in the middle and undergraduate nurses were the lowest.Methods after mercury leak also contained 10 items,in which nurses of secondary education scored the highest,nurses of junior college were in the middle and undergraduate nurses were the lowest,and the difference was statistically significant (P ＜ 0.01).There was also statistically significant difference of training needs about mercury knowledge between nurses of different education degrees (P ＜ 0.01).Conclusions Nurses' overall cognition about mercury leak of a broken bar glass thermometer was relatively lower,thus knowledge training of students and in-service staff should be strengthened,management of medical waste should be enhanced,disposal processing after thermometer breaks should be improved and knowledge about mercury hazards should be advanced to gradually promote the progress of hospital without mercury.
Key words:
Nurses; Cognition; Thermometer; Mercury leak
Scale-invariant feature transform (SIFT) has been well studied in recent years. Most related research efforts focused on designing and learning effective descriptors to characterize a local interest point. However, how to identify stable local interest points is still a very challenging problem. In this paper, we propose a set of differential features, and based on them we adopt a data-driven approach to learn a ranking function to sort local interest points according to their stabilities across images containing the same visual objects. Compared with the handcrafted rule-based method used by the standard SIFT algorithm, our algorithm substantially improves the stability of detected local interest point on a very challenging benchmark dataset, in which images were generated under very different imaging conditions. Experimental results on the Oxford and PASCAL databases further demonstrate the superior performance of the proposed algorithm on both object image retrieval and category recognition.
Abstract Context-dependent dynamic histone modifications constitute a key epigenetic mechanism in gene regulation. The Rpd3S complex recognizes H3K36 trimethylation (H3K36me3) and deacetylates histones H3 and H4 at multiple sites across transcribed regions. Here we solved the cryo-EM structures of yeast Rpd3S in its free and H3K36me3-nucleosome bound states. We demonstrated a unique architecture of Rpd3S, in which two copies of Eaf3-Rco1 heterodimers are asymmetrically assembled with Rpd3 and Sin3 to form a catalytic core complex. Multivalent recognition of two H3K36me3 marks, nucleosomal and linker DNAs by Eaf3, Sin3 and Rco1 positions the catalytic center of Rpd3 next to the histone H4 N-terminal tail for deacetylation. In an alternative catalytic mode, combinatorial readout of unmethylated H3K4 and H3K36me3 by Rco1 and Eaf3 directs histone H3-specific deacetylation except for the registered H3K9ac. Collectively, our work illustrates dynamic and diverse modes of multivalent nucleosomal engagement and methylation-guided deacetylation by Rpd3S, highlighting the exquisite complexity of epigenetic regulation with delicately designed multi-subunit enzymatic machineries in transcription and beyond.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
