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With the continuous implementation of ecological civilization and the transformation of multi-functional land management, the ecologicalization of land consolidation has entered a critical period of theoretic innovation and practical application. Systematically combing the development of theoretical research and practical exploration of ecological environment effect of land consolidation, and clarifying the service direction and implementation path of the land science discipline research under the "New Era" are urgent for the implementation of the "ecological" land consolidation stra-tegy. We reviewed the literatures on the ecological environment effects of land consolidation in the past 18 years. Using Citespace 1.0 software as analysis tool, we identified the research hotspots of ecological environmental effects of land consolidation, and discussed the mechanism of ecological environmental effects of land consolidation based on the analysis of relationship among ecological environment elements, ecological landscape and ecosystem services. Further, we proposed a new application path of "ecological" land consolidation from the measurement of regional ecosystem service level and the diagnosis of obstacle factors, the impact of land consolidation on regional ecosystem services and its mechanism, and the construction of ecological land consolidation model based on the promotion of ecosystem services, which aimed to provide a scientific basis for the restoration and construction of the life community of "mountains, rivers, forests, fields, lakes and grasses" in China.
Assuntos
Ecossistema , China , Clima , FlorestasRESUMO
The synthesis and growth of CH3NH3PbI3 films with controlled nucleation is a key issue for the high efficiency and stability of solar cells. Here, 4-tert-butylpyridine (tBP) was introduced into a CH3NH3PbI3 antisolvent to obtain high quality perovskite layers. In situ optical microscopy and X-ray diffraction patterns were used to prove that tBP significantly suppressed perovskite nucleation by forming an intermediate phase. In addition, a gradient perovskite structure was obtained by this method, which greatly improved the efficiency and stability of perovskites. An effective power conversion efficiency (PCE) of 17.41% was achieved via the tBP treatment, and the high-efficiency device could maintain over 89% of the initial PCE after 30 days at room temperature.
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Cardiomyocyte progenitor cells play essential roles in early heart development, which requires highly controlled cellular organization. microRNAs (miRs) are involved in various cell behaviors by post-transcriptional regulation of target genes. However, the roles of miRNAs in human cardiomyocyte progenitor cells (hCMPCs) remain to be elucidated. Our previous study showed that miR-134 was significantly downregulated in heart tissue suffering from congenital heart disease, underlying the potential role of miR-134 in cardiogenesis. In the present work, we showed that the upregulation of miR-134 reduced the proliferation of hCMPCs, as determined by EdU assay and Ki-67 immunostaining, while the inhibition of miR-134 exhibited an opposite effect. Both up- and downregulation of miR-134 expression altered the transcriptional level of cell-cycle genes. We identified Meis2 as the target of miR-134 in the regulation of hCMPC proliferation through bioinformatic prediction, luciferase reporter assay and western blot. The over-expression of Meis2 mitigated the effect of miR-134 on hCMPC proliferation. Moreover, miR-134 did not change the degree of hCMPC differentiation into cardiomyocytes in our model, suggesting that miR-134 is not required in this process. These findings reveal an essential role for miR-134 in cardiomyocyte progenitor cell biology and provide new insights into the physiology and pathology of cardiogenesis.
Assuntos
Proliferação de Células , Proteínas de Homeodomínio/metabolismo , MicroRNAs/genética , Mioblastos Cardíacos/metabolismo , Miócitos Cardíacos/metabolismo , Fatores de Transcrição/metabolismo , Células Cultivadas , Proteínas de Homeodomínio/genética , Humanos , Mioblastos Cardíacos/fisiologia , Miócitos Cardíacos/fisiologia , Fatores de Transcrição/genéticaRESUMO
The cellular mechanisms of primary varicose great saphenous veins (GSVs) involve inflammation, apoptosis, and proliferation of local cells and extracellular matrix degradation. Long non-coding RNAs (lncRNAs) play important roles in these cellular processes; however, which and how lncRNAs related to these mechanisms take effect on GSVs remain unclear. By screening lncRNAs that might experience changes in GSV varicosities, we selected the lower expressed lncRNA-GAS5 (growth arrest specific transcript 5) for functional assessments. Silencing of lncRNA-GAS5 promoted cell proliferation and migration, and cell cycle of the human saphenous vein smooth muscle cells (HSVSMCs), whereas overexpressing it inhibited these cellular behaviors and reduced apoptosis of HSVSMCs. RNA pull-down experiment revealed a direct bind of lncRNA-GAS5 to a Ca2+-dependent RNA-binding protein, Annexin A2. Further experiments showed that silencing of Annexin A2 reduced the HSVSMCs proliferation and vice versa. In the context of lncRNA-GAS5 knockdown, silencing of Annexin A2 reduced the proliferation of HSVSMCs while overexpression of Annexin A2 increased the proliferation. Thus, the low expression of lncRNA-GAS5 may facilitate HSVSMCs proliferation and migration through Annexin A2 and thereby the pathogenesis of GSV varicosities.