The epithelial-mesenchymal transition (EMT) is crucial to cancer progression and metastasis. Although multiple cellular miRNAs have been identified to regulate the EMT and metastasis in cancers, the ...role of viral miRNAs in cancer progression remains largely unknown. Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated malignancy typically characterized by its early metastasis. In the present study, we have discovered the involvement of a viral miRNA, EBV-miR-BART7-3p, in the EMT and metastasis of NPC cells. Initially, we observed that EBV-miR-BART7-3p was highly expressed in NPC and positively correlated with lymph node metastasis and clinical stage of NPC. Subsequently, we demonstrated that EBV-miR-BART7-3p enhanced cell migration/invasion in vitro, cancer metastasis in vivo, and particularly the EMT characterized by loss of epithelial markers and gain of mesenchymal features in NPC cells. Furthermore, mechanistic studies disclosed that EBV-miR-BART7-3p targeted a major human tumor suppressor PTEN, modulating PI3K/Akt/GSK-3β signaling and eventually leading to the high expression and nuclear accumulation of Snail and β-catenin, which favor EMT. Knockdown of PTEN could phenocopy the effect of EBV-miR-BART7-3p, whereas re-expression of PTEN resulted in a phenotypic reversion. Moreover, these findings were supported by an observation of an EBV-positive cell model in which silencing of endogenous EBV-miR-BART7-3p partially attenuated cell migration/invasion and altered EMT protein expression pattern via reverting PI3K/Akt, Snail and β-catenin expression. Thus, this study suggests a novel mechanism by which EBV-miR-BART7-3p modulates the EMT and metastasis of NPC cells, and a clinical implication of EBV-miR-BART7-3p as a potential biomarker or therapeutic target.
Coal fly ash, an industrial by-product, is derived from coal combustion in thermal power plants. It is one of the most complex and abundant of anthropogenic materials, and its improper disposal has ...become an environmental concern and resulted in a waste of recoverable resources. Coal fly ash is rich in alumina, making it a potential substitute for bauxite. With the diminishing reserves of bauxite resources as well as the increasing demand for alumina, recovering alumina from fly ash has attracted extensive attentions. The present review first describes the alumina recovery history and technologies, and then focuses on the recovery status in China. Finally, the current status of fly ash recycling and directions for future research are considered.
The hydrological response to climate change in mountainous basins manifests itself at varying spatial and temporal scales, ranging from catchment to large river basin scale and from sub‐daily to ...decade and century scale. To robustly assess the 21st century climate change impact for hydrology in entire High Mountain Asia (HMA) at a wide range of scales, we use a high resolution cryospheric‐hydrological model covering 15 upstream HMA basins to quantify the compound effects of future changes in precipitation and temperature based on the range of climate change projections in the Coupled Model Intercomparison Project Phase 6 climate model ensemble. Our analysis reveals contrasting responses for HMA's rivers, dictated by their hydrological regimes. At the seasonal scale, the earlier onset of melting causes a shift in the magnitude and peak of water availability, to earlier in the year. At the decade to century scale, after an initial increase, the glacier melt declines by the mid or end of the century except for the Tarim river basin, where it continues to increase. Despite a large variability in hydrological regimes across HMA's rivers, our results indicate relatively consistent climate change responses across HMA in terms of total water availability at decadal time scales. Although total water availability increases for the headwaters, changes in seasonality and magnitude may diverge widely between basins and need to be addressed while adapting to future changes in a region where food security, energy security as well as biodiversity, and the livelihoods of many depend on water from HMA.
Plain Language Summary
The mountains of Asia have large reservoirs of snow and ice, which are the source of water to the people living in the mountains and downstream, mainly during the dry season. However, due to recent warming, these reserves are melting faster and depleting year by year. We use a computer model to understand what will happen to these volumes of snow and ice and the total volume of water, which also includes rain and groundwater, in the 15 main rivers under future climate change scenarios. We find that the water generated upstream will increase for all the rivers in the future. However, there would be either too little or too much water for different seasons in the future. The peak volume of water will increase in magnitude and the peak time will shift to earlier in the season (in the month of May instead of current June or July) for most rivers in the western part of Asia. This change in the timing of water will have severe impacts on the livelihoods of mountain communities as well as populations downstream where food production, energy production as well as biodiversity depend on the amount and timing of mountain water supply.
Key Points
Contrasting seasonal responses are observed for High Mountain Asia's (HMA) rivers, dictated by their hydrological regimes
The onset of early snow and glacier melt in the spring season affects the magnitude and peak water availability
A relatively consistent decadal climate change responses across HMA, despite a large variability in hydrological regimes
Mountains are the water towers of the world, supplying a substantial part of both natural and anthropogenic water demands
. They are highly sensitive and prone to climate change
, yet their ...importance and vulnerability have not been quantified at the global scale. Here we present a global water tower index (WTI), which ranks all water towers in terms of their water-supplying role and the downstream dependence of ecosystems and society. For each water tower, we assess its vulnerability related to water stress, governance, hydropolitical tension and future climatic and socio-economic changes. We conclude that the most important (highest WTI) water towers are also among the most vulnerable, and that climatic and socio-economic changes will affect them profoundly. This could negatively impact 1.9 billion people living in (0.3 billion) or directly downstream of (1.6 billion) mountainous areas. Immediate action is required to safeguard the future of the world's most important and vulnerable water towers.
The impacts of future climate change on water balance for the headwater basins of six major rivers in the Tibetan Plateau are assessed using the well-established VIC-glacier land surface hydrological ...model driven by composite projections of 20 CMIP5 GCMs under scenarios RCP2.6, RCP4.5, and RCP8.5. At the plateau scale, the annual precipitation is projected to increase by 5.0–10.0% in the near term (2011–2040) and 10.0–20.0% in the long term (2041–2070) relative to the reference period 1971–2000. The annual temperature is projected to increase for all the scenarios with the greatest warming in the northwest (2.0–4.0°C) and least in the southeast (1.2–2.8°C). The total runoff of the study basins would either remain stable or moderately increase in the near term, and increase by 2.7–22.4% in the long term relative to the reference period, as a result of increased rainfall-induced runoff for the upstream of the Yellow, Yangtze, Salween, and Mekong and increased glacier melt for the upper Indus. In the upper Brahmaputra, more than 50.0% of the total runoff increase is attributed to the increased glacier melt in the long run. The annual hydrograph remains practically unchanged for all the monsoon-dominated basins. However, for the westerly-controlled basin (upper Indus), an apparent earlier melt and a relatively large increase in spring runoff are observed for all the scenarios, which would increase water availability in the Indus Basin irrigation scheme during the spring growing season.
•We have assessed the hydrological response to future climate changes for six head water basins in the Tibetan Plateau (TP).•The water supply from the major source river basins in the TP is unlikely to decline at least until 2070.•The increased glacier runoff is the main cause for the projected increase of total runoff for the upper Indus basin.•The increased rainfall runoff is the dominant cause for the total runoff increase for the monsoon-dominated basins.
Coal fly ash, an industrial by-product, is derived from coal combustion in thermal power plants. It is one of the most complex anthropogenic materials, and its improper disposal has become an ...environmental concern and resulted in a waste of recoverable resources. There is a pressing and ongoing need to develop new recycling methods for coal fly ash. The present review first describes the generation, physicochemical properties and hazards of coal fly ash at the global level, and then focuses on its current and potential applications, including use in the soil amelioration, construction industry, ceramic industry, catalysis, depth separation, zeolite synthesis, etc. Finally, the advantages and disadvantages of these applications, the mode of fly ash utilization worldwide and directions for future research are considered.
Previous studies indicate that catheter-based renal denervation reduces blood pressure and renal norepinephrine spillover in human resistant hypertension. The effects of this procedure on afferent ...sensory and efferent sympathetic renal nerves, and the subsequent degree of reinnervation, have not been investigated. We therefore examined the level of functional and anatomic reinnervation at 5.5 and 11 months after renal denervation using the Symplicity Flex catheter. In normotensive anesthetized sheep (n=6), electric stimulation of intact renal nerves increased arterial pressure from 99±3 to 107±3 mm Hg (afferent response) and reduced renal blood flow from 198±16 to 85±20 mL/min (efferent response). In a further group (n=6), immediately after denervation, renal sympathetic nerve activity was absent and the responses to electric stimulation were abolished. At 11 months after denervation (n=5), renal sympathetic nerve activity and the responses to electric stimulation were at normal levels. Immunohistochemical staining for renal efferent (tyrosine hydroxylase) and renal afferent nerves (calcitonin gene-related peptide), as well as renal norepinephrine levels, was normal 11 months after denervation. Findings at 5.5 months after denervation were similar (n=5). In summary, catheter-based renal denervation effectively ablated the renal afferent and efferent nerves in normotensive sheep. By 11 months after denervation the functional afferent and efferent responses to electric stimulation were normal. Reinnervation at 11 months after denervation was supported by normal anatomic distribution of afferent and efferent renal nerves. In view of this evidence, the mechanisms underlying the prolonged hypotensive effect of catheter-based renal denervation in human resistant hypertension need to be reassessed.
Previous in situ measurements have indicated a slight mass gain at Muztagh Ata in the eastern Pamir, contrary to the global trend. We extend these measurements both in space and time by using remote ...sensing data and present four decades of glacier variations in the entire mountain massif. Geodetic mass balances and area changes were determined at glacier scale from stereo satellite imagery and derived digital elevation models (DEMs). This includes Hexagon KH-9 (year 1973), ALOS-PRISM~(2009), Pléiades (2013) and Landsat 7 ETM+ data in conjunction with the SRTM-3 DEM (2000). In addition, surface velocities of Kekesayi Glacier, the largest glacier at Muztagh Ata, were derived from amplitude tracking of TerraSAR-X images (2011). Locally, we observed strong spatial and temporal glacier variations during the last four decades, which were, however, on average not significant for the entire massif. Some south-west-exposed glaciers fluctuated or advanced, while glaciers with other aspects rather experienced continuous shrinkage. Several glaciers such as Kekesayi indicate no measurable change at their frontal position, but clear down-wasting despite mostly thick debris coverage at low altitudes. The surface velocity of this debris-covered glacier reach up to 20 cm per day, but the lowest part of the tongue appears to be stagnant. The low velocity or even stagnancy at the tongue is likely one reason for the down-wasting. On average, the glaciers showed a small, insignificant shrinkage from 274.3 ± 10.6 km2 in 1973 to 272.7 ± 1.0 km2 in 2013 (−0.02 ± 0.1 % a−1). Average mass changes in the range of −0.03 ± 0.33 m w.e. a−1 (1973–2009) to −0.01 ± 0.30 m w.e. a−1 (1973–2013) reveal nearly balanced budgets for the last 40 years. Indications of slightly positive rates after 1999 (+0.04 ± 0.27 m w.e. a−1) are not significant, but confirmed by measurements in the field.
Kinetic‐scale magnetic dips (KSMDs), with a significant depression in magnetic field strength, and scale length close to and less than one proton gyroradius, were reported in the turbulent plasmas ...both in recent observation and numerical simulation studies. These KSMDs likely play important roles in energy conversion and dissipation. In this study, we present observations of the KSMDs that are labeled whistler mode waves, electrostatic solitary waves, and electron cyclotron waves in the magnetosheath. The observations suggest that electron temperature anisotropy or beams within KSMD structures provide free energy to generate these waves. In addition, the occurrence rates of the waves are higher in the center of the magnetic dips than at their edges, implying that the KSMDs might be the origin of various kinds of waves. We suggest that the KSMDs could provide favorable conditions for the generation of waves and transfer energy to the waves in turbulent magnetosheath plasmas.
Plain Language Summary
The Earth's magnetosheath is a turbulent plasma environment where energy conversion, particle acceleration, and mass and momentum transport take place. Many of these key processes involve kinetic‐scale physics. However, in‐depth studies from previous missions are limited by their lower spacecraft data resolution. The recent Magnetospheric Multiscale (MMS) mission provides us with a large amount of high‐temporal cadence data for studying kinetic‐scale physics in the magnetosheath. In this study, we report whistler mode waves, electrostatic solitary waves and electron cyclotron waves within kinetic‐scale magnetic dips (KSMDs) that can be generated in the turbulent magnetosheath. These waves could be excited by electron temperature anisotropy or beams. As is well known, plasma waves are important processes in converting energy, accelerating and scattering electrons and ions, and modifying the distributions of charged particles. If plasma instabilities develop within the KSMDs, the resulting waves could absorb free energy from plasma particles and may propagate out of the KSMDs. Thus, our discoveries could significantly advance the understanding of energy conversion and dissipation for kinetic‐scale turbulence. This study provides a new reference not only for observations in space physics but also for related basic plasma theories and numerical simulations.
Key Points
MMS observations reveal KSMDs coupled with whistler mode waves, electrostatic solitary waves, and electron cyclotron waves
These waves are excited by different plasma distributions, and the ESWs could affect the electron distributions in kinetic scale
Statistical results indicate that the KSMDs in the magnetosheath are a possible origin for various kinds of waves
The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and ...transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.
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