Organic photovoltaics are an important part of a next‐generation energy‐harvesting technology that uses a practically infinite pollutant‐free energy source. They have the advantages of light weight, ...solution processability, cheap materials, low production cost, and deformability. However, to date, the moderate photovoltaic efficiencies and poor stabilities of organic photovoltaics impede their use as replacements for inorganic photovoltaics. Recent developments in bulk‐heterojunction organic photovoltaics mean that they have almost reached the lower efficiency limit for feasible commercialization. In this review article, the recent understanding of the ideal bulk‐heterojunction morphology of the photoactive layer for efficient exciton dissociation and charge transport is described, and recent attempts as well as early‐stage trials to realize this ideal morphology are discussed systematically from a morphological viewpoint. The various approaches to optimizing morphologies consisting of an interpenetrating bicontinuous network with appropriate domain sizes and mixed regions are categorized, and in each category, the recent trends in the morphology control on the multilength scale are highlighted and discussed in detail. This review article concludes by identifying the remaining challenges for the control of active layer morphologies and by providing perspectives toward real application and commercialization of organic photovoltaics.
The morphology of the bulk‐heterojunction photoactive layer critically influences charge‐carrier dynamics and therefore the overall photovoltaic performance of organic photovoltaics. The morphological issues reported so far are discussed and future directions toward further optimization are suggested.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The potential roles of temperature and phytoplankton in nutrient cycling throughout the water column were investigated nearby aquaculture farms. Using the convergent cross mapping (CCM), we examined ...the relative strength of phytoplankton and temperature effects on nutrients. High δ15N values of particulate organic matter in the inner bay were detected compared to those in the outer bay. δ15N values >5 ‰ throughout the bay indicate that nitrogen influxes from the aquaculture farms are the critical nitrogen source in the study region. Our CCM models revealed that temperature positively and strongly affected the potential regeneration of nutrients, associated with PO43− while phytoplankton utilized nutrients as soon as available. The temperature–driven nutrient regeneration was higher in the bottom layer than that in the surface layer, indicating that temperature was a more important controlling factor in nutrient fluxes from the surface sediments.
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•Convergent cross mapping model was applied to detect the strength of thermal effects on nutrients.•Water temperature positively and strongly affected the potential regeneration of nutrients.•Phytoplankton less affected the potential regeneration of nutrients.•Coastal waters experienced a steady rise of sea surface temperature.•The intensity of thermal impacts on nutrient will be gradually enhanced.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Phylogenetic network analysis and understanding of waterfowl migration patterns suggest that the Eurasian H5N8 clade 2.3.4.4 avian influenza virus emerged in late 2013 in China, spread in early 2014 ...to South Korea and Japan, and reached Siberia and Beringia by summer 2014 via migratory birds. Three genetically distinct subgroups emerged and subsequently spread along different flyways during fall 2014 into Europe, North America, and East Asia, respectively. All three subgroups reappeared in Japan, a wintering site for waterfowl from Eurasia and parts of North America.
Standing poloidal Alfven waves, radial oscillations with ultralow frequency of 5–20 mHz, are excited by wave‐particle interaction in the magnetosphere. It has been a question over several decades why ...poloidal oscillations often persist and are not quickly converted into toroidal waves even when there is no corresponding particle source. By adopting magnetohydrodynamic simulations in the dipole model, we first show that long‐lasting poloidal waves are available if the local Alfven frequency gradient becomes negligible. Assuming that initial poloidal modes are excited by driving particles, we investigate two loss mechanisms into either toroidal modes or compressional modes. Both mechanisms enable us to derive two necessary conditions for the existence of persistent poloidal modes. It is found that these conditions are very consistent with statistical feature of observations. Our results will be useful in identifying the persistent poloidal mode in terms of the corresponding particle energy and wavenumbers.
Plain Language Summary
Ultralow frequency oscillations in the radial direction are often called poloidal Alfven waves. In a theoretical sense, they should be transient or short‐lived since they tend to be absorbed into the east‐west oscillations called toroidal modes. However, many observations show that long‐lasting poloidal modes exist even if there is no corresponding driving source at that moment. We theoretically study how this could happen and what kinds of conditions are required for persistent poloidal waves. We start by showing that constant Alfven frequency at a certain local region can make the poloidal lifetime longer. We derive two new, simple types of very useful necessary conditions, where we can get the conditions in terms of particle energy and wave numbers, which are found to be also consistent with the statistics of observations.
Key Points
Long‐lasting poloidal Alfven waves with no corresponding particle sources are often observed, but no theories are available yet
We derive two new necessary conditions for the existence of persistent poloidal modes in terms of energy and wavenumber
We present a statistical database to compare its events with the theoretical conditions, which are very consistent with the observations
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
High-pathogenicity avian influenza (HPAI) viruses have arisen from low-pathogenicity avian influenza (LPAI) viruses via changes in the hemagglutinin proteolytic cleavage site, which include mutation ...of multiple nonbasic to basic amino acids, duplication of basic amino acids, or recombination with insertion of cellular or viral amino acids. Between 1959 and 2019, a total of 42 natural, independent H5 (
= 15) and H7 (
= 27) LPAI to HPAI virus conversion events have occurred in Europe (
= 16), North America (
= 9), Oceania (
= 7), Asia (
= 5), Africa (
= 4), and South America (
= 1). Thirty-eight of these HPAI outbreaks were limited in the number of poultry premises affected and were eradicated. However, poultry outbreaks caused by A/goose/Guangdong/1/1996 (H5Nx), Mexican H7N3, and Chinese H7N9 HPAI lineages have continued. Active surveillance and molecular detection and characterization efforts will provide the best opportunity for early detection and eradication from domestic birds.
Novel subtypes of Asian-origin (Goose/Guangdong lineage) H5 highly pathogenic avian influenza (HPAI) viruses belonging to clade 2.3.4, such as H5N2, H5N5, H5N6, and H5N8, have been identified in ...China since 2008 and have since evolved into four genetically distinct clade 2.3.4.4 groups (A-D). Since 2014, HPAI clade 2.3.4.4 viruses have spread rapidly via migratory wild aquatic birds and have evolved through reassortment with prevailing local low pathogenicity avian influenza viruses. Group A H5N8 viruses and its reassortant viruses caused outbreaks in wide geographic regions (Asia, Europe, and North America) during 2014-2015. Novel reassortant Group B H5N8 viruses caused outbreaks in Asia, Europe, and Africa during 2016-2017. Novel reassortant Group C H5N6 viruses caused outbreaks in Korea and Japan during the 2016-2017 winter season. Group D H5N6 viruses caused outbreaks in China and Vietnam. A wide range of avian species, including wild and domestic waterfowl, domestic poultry, and even zoo birds, seem to be permissive for infection by and/or transmission of clade 2.3.4.4 HPAI viruses. Further, compared to previous H5N1 HPAI viruses, these reassortant viruses show altered pathogenicity in birds. In this review, we discuss the evolution, global spread, and pathogenicity of H5 clade 2.3.4.4 HPAI viruses.
Interferon lambda (IFNλ), classified as a type III IFN, is a representative cytokine that plays an important role in innate immunity along with type I IFN. IFNλ can elicit antiviral states by ...inducing peculiar sets of IFN‐stimulated genes (ISGs). In this study, an adenoviral vector expression system with a tetracycline operator system was used to express human IFNλ4 in cells and mice. The formation of recombinant adenovirus (rAd‐huIFNλ4) was confirmed using immunohistochemistry assays and transmission electron microscopy. Its purity was verified by quantifying host cell DNA and host cell proteins, as well as by confirming the absence of the replication‐competent adenovirus. The transduction of rAd‐huIFNλ4 induced ISGs and inhibited four subtypes of the influenza virus in both mouse‐derived (LA‐4) and human‐derived cells (A549). The antiviral state was confirmed in BALB/c mice following intranasal inoculation with 109 PFU of rAd‐huIFNλ4, which led to the inhibition of four subtypes of the influenza virus in mouse lungs, with reduced inflammatory lesions. These results imply that human IFNλ4 could induce antiviral status by modulating ISG expression in mice.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Glioblastoma multiforme (GBM) displays cellular hierarchies harboring a subpopulation of stem-like cells (GSCs). Enhancer of Zeste Homolog 2 (EZH2), the lysine methyltransferase of Polycomb ...repressive complex 2, mediates transcriptional repression of prodifferentiation genes in both normal and neoplastic stem cells. An oncogenic role of EZH2 as a transcriptional silencer is well established; however, additional functions of EZH2 are incompletely understood. Here, we show that EZH2 binds to and methylates STAT3, leading to enhanced STAT3 activity by increased tyrosine phosphorylation of STAT3. The EZH2-STAT3 interaction preferentially occurs in GSCs relative to non-stem bulk tumor cells, and it requires a specific phosphorylation of EZH2. Inhibition of EZH2 reverses the silencing of Polycomb target genes and diminishes STAT3 activity, suggesting therapeutic strategies.
•EZH2 activates STAT3 signaling via lysine methylation of STAT3•EZH2 and STAT3 preferentially interact in stem-like tumor cells•AKT serves as an upstream inducer of EZH2 to promote activation of STAT3•EZH2 inhibition reverses Polycomb-mediated silencing and decreases STAT3 activity
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Recently, chain termination sequencing methods have been replaced by more efficient next-generation sequencing (NGS) methods. For influenza A, NGS allows for deep sequencing to characterize virus ...populations, efficient complete genome sequencing, and a non-sequence-dependent method to identify viral variants. There are numerous approaches to preparing samples for NGS and subsequent data processing methods that can be applied to influenza A sequencing. This chapter provides a brief overview of the process of NGS for influenza A and some useful bioinformatics tools for developing an NGS workflow for influenza A viruses.
Tin selenides with layered crystal structures, SnSe and SnSe2, were synthesized by a solid-state method and electrochemically tested for use as Li-ion battery anodes. The phase change mechanisms of ...these compounds were thoroughly evaluated by ex situ X-ray diffraction and Se K-edge extended X-ray absorption fine structure techniques. SnSe showed better electrochemical reversibility of Li insertion/extraction than SnSe2, which was attributed to remarkable conversion/recombination reactions of the former compound during lithiation/delithiation. Additionally, the electrochemical performance of SnSe was further enhanced by preparing carbon-modified nanocomposites using two different methods, that is, heat treatment (HT) for producing a carbon coating using polyvinyl chloride as a precursor and high-energy ball milling (BM) using carbon black powder. The SnSe/C electrode produced by BM showed a highly reversible initial capacity of 726 mA h g–1 with a good initial Coulombic efficiency of ∼82%, excellent cycling behavior (626 mA h g–1 after 200 cycles), and a fast C-rate performance (580 mA h g–1 at 2C rate).
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IJS, KILJ, NUK, PNG, UL, UM
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