Large-conductance Ca2 +-activated K+ channel β1-subunit maintains the contractile phenotype of vascular smooth muscle cells

BackgroundVascular smooth muscle cells (VSMCs) phenotype switching is very important during the pathogenesis and progression of vascular diseases. However, it is not well understood how normal VSMCs maintain the differentiated state. The large-conductance Ca2+-activated K+ (BKCa) channels are widely expressed in VSMCs and regulate vascular tone. Nevertheless, there is limited understanding of the role of the BKCa channel in modulation of the VSMC phenotype.Methods and resultsWe assessed BKCa channel expression levels in normal and injured carotid arteries from rats of the balloon-injury model. A strong decrease of BKCa-β1 was seen in the injured carotid arteries, accompanied by a parallel decrease of the VSMC contractile markers. BKCa-β1 in primary rat aortic VSMCs was decreased with the increase of passage numbers and the stimulation of platelet-derived growth factor (PDGF)-BB. Conversely, transforming growth factor β upregulated BKCa-β1. Meanwhile, the BKCa-β1 level was positively associated with the levels of VSMC contractile proteins. Intravenous injection of PDGF-BB induced downregulation of BKCa-β1 expression in the carotid arteries. Knockdown of BKCa-β1 favored VSMC dedifferentiation, characterized by altered morphology, abnormal actin fiber organization, decreased contractile proteins expression and reduced contractile ability. Furthermore, the resultant VSMC dedifferentiated phenotype rendered increased proliferation, migration, enhanced inflammatory factors levels, and matrix metalloproteinases activity. Studies using primary cultured aortic VSMCs from human recapitulated key findings. Finally, protein level of BKCa-β1 was reduced in human atherosclerotic arteries.ConclusionBKCa-β1 is important in the maintenance of the contractile phenotype of VSMCs. As a novel endogenous defender that prevents pathological VSMC phenotype switching, BKCa-β1 may serve as a potential therapeutic target for treating vascular diseases including post-injury restenosis and atherosclerosis

Reconversión laboral del sector agropecuario hacia el turismo. Desafíos para la Patagonia chilena

[EN] The development of tourism can help to diversify the productive matrix and reduce rural depopulation. This study analyzes the possibility of agricultural worker participation in the tourism sector in rural areas of Chilean Patagonia. Based on the 2017 CASEN survey, data matching and estimation of logit model are conducted to evaluate the probability of agricultural worker reconversion. The results indicate that the proportion of agricultural workers who can move to tourism is low. However, women and individuals with post-secondary education are more likely to be reconverted.[ES] La actividad turística puede ayudar a diversificar la matriz productiva y reducir el despoblamiento rural. Este estudio analiza la posibilidad de participación de trabajadores agropecuarios en el sector turismo en las zonas rurales de la Patagonia Chilena. Usando la encuesta CASEN del año 2017, se realiza un proceso de emparejamiento de datos (matching) y la estimación de un modelo logit para evaluar la probabilidad de reconversión laboral. Los resultados indican que hay una baja proporción de trabajadores que puedan transitar hacia el sector turismo. Sin embargo, las mujeres y los individuos con estudios postsecundarios tienen mayores probabilidades de reconversión.Este trabajo está enmarcado dentro del proyecto de investigación “La Vocación Productiva, el Nivel Educativo y la Funcionalidad del Centro Emisor y Receptor como Factores Explicativos de la Conmutación Inter e Intrarregional en la Región de los Andes Australes de la Patagonia Chilena”, financiado por CONICYT (Proyecto Fondecyt Número 1160196), por lo que los autores agradecen dichos aportes.Mancilla, C.; Ferrada, LM.; Soza-Amigo, S. (2019). Labour reconversion of the agricultural sector towards tourism. Challenges for Chilean Patagonia. Economía Agraria y Recursos Naturales - Agricultural and Resource Economics. 19(1):175-194. https://doi.org/10.7201/earn.2019.01.0917519419

Tube-like α-Fe2O3@Ag/AgCl heterostructure: controllable synthesis and enhanced plasmonic photocatalytic activity

Plasmonic photocatalysts coupled with semiconductors are one of the most popular combinations in environmental remediation applications. In this regard, a novel tube-like α-Fe2O3@Ag/AgCl hybrid structure is fabricated by anchoring Ag/AgCl hybrid nanoparticles on the surface of α-Fe2O3 short nanotubes (SNTs) by a step-by-step strategy. Firstly, the monodispersed α-Fe2O3 SNTs have been synthesized via an anion-assisted hydrothermal process followed by the loading of Ag nanoparticles on the surface of α-Fe2O3 SNTs through the classic silver mirror reaction mechanism. From in situ oxidation of Ag nanoparticles, the final product α-Fe2O3@Ag/AgCl heterostructures has been obtained. We study the morphology, composition, and photocatalytic properties of the as obtained tube-like α-Fe2O3@Ag/AgCl nano-heterostructures. The photocatalytic activities of as obtained photocatalysts have been tested by the degradation of organic dye Rhodamine B (RhB) under simulated sunlight (UV + visible light), visible light and UV light irradiation. The main reason for the enhanced photocatalytic performance is attributed to the broad spectral response from the combination of narrow/wide bandgap semiconductors with metallic Ag nanoparticles and efficient charge transfer from plasmon-excited Ag nanoparticles to α-Fe2O3 and AgCl. Finally, this hybrid structure provides a roadmap for the controlled synthesis of plasmonic photocatalysts with excellent properties, and can be used for practical application in environmental issues

Assessment of concentrated solar power generation potential in China based on Geographic Information System (GIS)

Concentrated solar power (CSP) technology can not only match peak demand in power systems but also play an important role in the carbon neutrality pathway worldwide. Actions in China is decisive. Few previous studies have estimated CSP technology’s power generation and CO2 emission reduction potentials in China. To address this knowledge gap, the geographical, technical, and CO2 emission reduction potential of CSP in China was evaluated by province based on a high resolution geographical information system with up-to-date data. A comprehensive framework including geographic and technical constrains was proposed. Exclusion criteria including solar radiation, slope, land-use type, natural reserve, and water resources were adopted to determine the suitability of CSP plant construction. Then, based on the power conversion efficiency difference from various CSP technologies, the technical potential was calculated on suitable land. The results show that approximately 1.02 × 106 km2 of land is available to support CSP development in China. Based on the available solar resource on the suitable land, the geographical potential is 2.13 × 1015 kWh. The potential installed capacity is 2.45 × 107–5.40 × 107 MW, considering four CSP technologies. The corresponding annual energy generation potential is 6.46 × 1013–1.85 × 1014 kWh. Considering the scenario of using the potential of CSP to replace the current power supply to the maximum extent, CO2 emission would have been reduced by 5.19 × 108, 5.61 × 108, and 6.24 × 108 t in 2017, 2018, and 2019, respectively. At the provincial level, more than 99% of China’s technical potential is concentrated in five western provinces, including Xinjiang, Inner Mongolia, Qinghai, Gansu, and Tibet. These results provide policy guidance and serve as a reference for the future development of CSP and site selection for CSP plant construction both in China and worldwide

Additional file 1: Figure S1. of Zinc Oxide Coating Effect for the Dye Removal and Photocatalytic Mechanisms of Flower-Like MoS2 Nanoparticles

Supporting information is available online from the Wiley Online Library or from the author. (DOCX 1281 kb

Tube-like ternary α-Fe2O3@SnO 2@Cu2O sandwich heterostructures: Synthesis and enhanced photocatalytic properties

Heterogeneous photocatalysis is of great interest for environmental remediation applications. However, fast recombination of photogenerated electron–hole pair and a low utilization rate of sunlight hinder the commercialization of currently available semiconductor photocatalysts. In this regard, we developed a unique ternary single core-double shell heterostructure that consists of α-Fe2O3@SnO2@Cu2O. This heterostructure exhibits a tube-like morphology possessing broad spectral response for the sunlight due to the combination of narrow bandgap and wide bandgap semiconductors forming a p–n heterojunction. To fabricate such a short nanotube (SNT), we used an anion-assisted hydrothermal route for deposition of α-Fe2O3, a seed-mediated deposition strategy for SnO2, and finally an aging process to deposit a Cu2O layer to complete the tube-like ternary α-Fe2O3@SnO2@Cu2O single core-double shell heterostructures. The morphology, composition, and photocatalytic properties of those ternary core–shell–shell heterostructures were characterized by various analytical techniques. These ternary heterostructures exhibited enhanced photocatalytic properties on the photodegradation of the organic dye of Rhodamine B (RhB) under simulated sunlight irradiation. The origin of enhanced photocatalytic activity is due to the synergistic effect of broad spectral response by combining narrow bandgap and wide bandgap semiconductors and, hence, an efficient charge separation of photogenerated electron–hole pairs facilitated through the p–n heterojunction. Furthermore, our unique structure provides an insight on the fabrication and controlled preparation of multilayer heterostructural photocatalysts that have intriguing properties

Data_Sheet_1_Large-conductance Ca2 +-activated K+ channel β1-subunit maintains the contractile phenotype of vascular smooth muscle cells.docx

BackgroundVascular smooth muscle cells (VSMCs) phenotype switching is very important during the pathogenesis and progression of vascular diseases. However, it is not well understood how normal VSMCs maintain the differentiated state. The large-conductance Ca2+-activated K+ (BKCa) channels are widely expressed in VSMCs and regulate vascular tone. Nevertheless, there is limited understanding of the role of the BKCa channel in modulation of the VSMC phenotype.Methods and resultsWe assessed BKCa channel expression levels in normal and injured carotid arteries from rats of the balloon-injury model. A strong decrease of BKCa-β1 was seen in the injured carotid arteries, accompanied by a parallel decrease of the VSMC contractile markers. BKCa-β1 in primary rat aortic VSMCs was decreased with the increase of passage numbers and the stimulation of platelet-derived growth factor (PDGF)-BB. Conversely, transforming growth factor β upregulated BKCa-β1. Meanwhile, the BKCa-β1 level was positively associated with the levels of VSMC contractile proteins. Intravenous injection of PDGF-BB induced downregulation of BKCa-β1 expression in the carotid arteries. Knockdown of BKCa-β1 favored VSMC dedifferentiation, characterized by altered morphology, abnormal actin fiber organization, decreased contractile proteins expression and reduced contractile ability. Furthermore, the resultant VSMC dedifferentiated phenotype rendered increased proliferation, migration, enhanced inflammatory factors levels, and matrix metalloproteinases activity. Studies using primary cultured aortic VSMCs from human recapitulated key findings. Finally, protein level of BKCa-β1 was reduced in human atherosclerotic arteries.ConclusionBKCa-β1 is important in the maintenance of the contractile phenotype of VSMCs. As a novel endogenous defender that prevents pathological VSMC phenotype switching, BKCa-β1 may serve as a potential therapeutic target for treating vascular diseases including post-injury restenosis and atherosclerosis.</p

Template and Silica Interlayer Tailorable Synthesis of Spindle-like Multilayer α‑Fe₂O₃/Ag/SnO₂ Ternary Hybrid Architectures and Their Enhanced Photocatalytic Activity

Our study reports a novel iron oxide/noble metal/semiconductor ternary multilayer hybrid structure that was synthesized through template synthesis and layer-by-layer deposition. Three different morphologies of α-Fe₂O₃/Ag/SiO₂/SnO₂ hybrid architectures were obtained with different thicknesses of the SiO₂ interlayer which was introduced for tailoring and controlling the coupling of noble metal Ag nanoparticles (NPs) with the SnO₂ semiconductor. The resulting samples were characterized in terms of morphology, composition, and optical property by various analytical techniques. The as-obtained α-Fe₂O₃/Ag/SiO₂/SnO₂ nanocomposites exhibit enhanced visible light or UV photocatalytic abilities, remarkably superior to commercial pure SnO₂ products, bare α-Fe₂O₃ seeds, and α-Fe₂O₃/SnO₂ nanocomposites. Moreover, the sample of α-Fe₂O₃/Ag/SiO₂/SnO₂ also exhibits good chemical stability and recyclability because it has higher photocatalytic activity even after eight cycles. The origin of enhanced photocatalytic activity on the multilayer core–shell α-Fe₂O₃/Ag/SiO₂/SnO₂ nanocomposites was primarily ascribed to the coupling between noble metal Ag and the two semiconductors Fe₂O₃ and SnO₂, which are proven to be applied in recyclable photocatalysis

3D Flowerlike α‑Fe₂O₃@TiO₂ Core–Shell Nanostructures: General Synthesis and Enhanced Photocatalytic Performance

The 3D flowerlike α-Fe₂O₃@TiO₂ core–shell nanocrystals with thorhombic, cubic, and discal morphologies are synthesized for photocatalytic application. α-Fe₂O₃ nanocrystals were prepared via a Cu²⁺, Zn²⁺, and Al³⁺ ion-mediated hydrothermal route. The α-Fe₂O₃@TiO₂ core–shell nanocrystals are obtained via a hydrothermal and annealing process. The shape-dependent photocatalytic activities of these as-obtained α-Fe₂O₃@TiO₂ core–shell nanocrystals are measured. The results reveal that the discal α-Fe₂O₃@TiO₂ nanocrystals exhibit the best photocatalytic activity relative to the other two core–shell nanocrystals because the discal α-Fe₂O₃ nanocrystals possess more rough surface and surface defects. The fast interfacial charge-transfer process and the wide spectral response could be the driving force for the enhanced photocatalytic performance. These core–shell architectures provide a positive example for synthesis of novel composite nanomaterial