The recent dramatic rise in power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) has triggered intense research worldwide. However, high PCE values have often been reached with poor stability at an illuminated area of typically less than 0.1 square centimeter. We used heavily doped inorganic charge extraction layers in planar PSCs to achieve very rapid carrier extraction, even with 10- to 20-nanometer-thick layers, avoiding pinholes and eliminating local structural defects over large areas. The robust inorganic nature of the layers allowed for the fabrication of PSCs with an aperture area >1 square centimeter that have a PCE >15%, as certified by an accredited photovoltaic calibration laboratory. Hysteresis in the current-voltage characteristics was eliminated; the PSCs were stable, with >90% of the initial PCE remaining after 1000 hours of light soaking.
The worldwide unrestrained emission of carbon dioxide (CO2) has caused serious environmental pollution and climate change issues. For the sustainable development of human civilization, it is very desirable to convert CO2 to renewable fuels through clean and economical chemical processes. Recently, electrocatalytic CO2 conversion is regarded as a prospective pathway for the recycling of carbon resource and the generation of sustainable fuels. In this review, recent research advances in electrocatalytic CO2 reduction are summarized from both experimental and theoretical aspects. The referred electrocatalysts are divided into different classes, including metal–organic complexes, metals, metal alloys, inorganic metal compounds and carbon‐based metal‐free nanomaterials. Moreover, the selective formation processes of different reductive products, such as formic acid/formate (HCOOH/HCOO−), monoxide carbon (CO), formaldehyde (HCHO), methane (CH4), ethylene (C2H4), methanol (CH3OH), ethanol (CH3CH2OH), etc. are introduced in detail, respectively. Owing to the limited energy efficiency, unmanageable selectivity, low stability, and indeterminate mechanisms of electrocatalytic CO2 reduction, there are still many tough challenges need to be addressed. In view of this, the current research trends to overcome these obstacles in CO2 electroreduction field are summarized. We expect that this review will provide new insights into the further technique development and practical applications of CO2 electroreduction.
Robust nanofiber gels: Monolithic hydrogels and aerogels consisting of uniform carbonaceous nanofibers (CNFs) were fabricated on a macroscopic scale (12 L, see picture) by a simple template‐directed, hydrothermal carbonization process. The high surface reactivity of the CNFs and high porosity and robust nature of the gels can be exploited in applications such as selective adsorbents and templates for creating functional composite gels.
An average cell contains thousands of proteins that participate in normal cellular functions, and most diseases are somehow related to the malfunctioning of one or more of these proteins. Protein therapy, which delivers proteins into the cell to replace the dysfunctional protein, is considered the most direct and safe approach for treating disease. However, the effectiveness of this method has been limited by its low delivery efficiency and poor stability against proteases in the cell, which digest the protein. Here, we show a novel delivery platform based on nanocapsules consisting of a protein core and a thin permeable polymeric shell that can be engineered to either degrade or remain stable at different pHs. Non-degradable capsules show long-term stability, whereas the degradable ones break down their shells, enabling the core protein to be active once inside the cells. Multiple proteins can be delivered to cells with high efficiency while maintaining low toxicity, suggesting potential applications in imaging, therapy and cosmetics fields.
This report describes an unbiased method for systematically determining gene function in mammalian cells. A total of 20,704 predicted human full-length cDNAs were tested for induction of the IL-8 promoter. A number of genes, including those for cytokines, receptors, adapters, kinases, and transcription factors, were identified that induced the IL-8 promoter through known regulatory sites. Proteins that acted through a cooperative interaction between an AP-1 and an unrecognized cAMP response element (CRE)-like site were also identified. A protein, termed transducer of regulated cAMP response element-binding protein (CREB) (TORC1), was identified that activated expression through the variant CRE and consensus CRE sites. TORC1 potently induced known CREB1 target genes, bound CREB1, and activated expression through a potent transcription activation domain. A functional Drosophila TORC gene was also identified. Thus, TORCs represent a family of highly conserved CREB coactivators that may control the potency and specificity of CRE-mediated responses.IL-8 ͉ genomics ͉ high-throughput screening ͉ transducer of regulated cAMP response element-binding protein
Erythroid Krüppel-like factor (EKLF) is a red cell-specific transcriptional activator that is crucial for consolidating the switch to high levels of adult -globin expression during erythroid ontogeny. EKLF is required for integrity of the chromatin structure at the -like globin locus, and it interacts with a positive-acting factor in vivo. We find that EKLF is an acetylated transcription factor, and that it interacts in vivo with CBP, p300, and P͞CAF. However, its interactions with these histone acetyltransferases are not equivalent, as CBP and p300, but not P͞CAF, utilize EKLF as a substrate for in vitro acetylation within its trans-activation region. The functional effects of these interactions are that CBP and p300, but not P͞CAF, enhance EKLF's transcriptional activation of the -globin promoter in erythroid cells. These results establish EKLF as a tissue-specific transcription factor that undergoes post-translational acetylation and suggest a mechanism by which EKLF is able to alter chromatin structure and induce -globin expression within the -like globin cluster.
Recently, numerous types of human dental tissue‐derived mesenchymal stem cells (MSCs) have been isolated and characterized, including dental pulp stem cells, stem cells from exfoliated deciduous teeth, periodontal ligament stem cells, dental follicle progenitor cells, alveolar bone‐derived MSCs, stem cells from apical papilla, tooth germ progenitor cells, and gingival MSCs. All these MSC‐like cells exhibit self‐renewal, multilineage differentiation potential, and immunomodulatory properties. Several studies have demonstrated the potential advantages of dental stem cell‐based approaches for regenerative treatments and immunotherapies. This review outlines the properties of various dental MSC‐like populations and the progress toward their use in regenerative therapy. Several dental stem cell banks worldwide are also introduced, with a view toward future clinical application. Stem Cells 2015;33:627–638
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