Hepatitis E virus (HEV) is a small, non-enveloped, single-strand, positive-sense RNA virus of approximately 7.2
kb in size. HEV is classified in the family
Hepeviridae consisting of four recognized ...major genotypes that infect humans and other animals. Genotypes 1 and 2 HEV are restricted to humans and often associated with large outbreaks and epidemics in developing countries with poor sanitation conditions, whereas genotypes 3 and 4 HEV infect humans, pigs and other animal species and are responsible for sporadic cases of hepatitis E in both developing and industrialized countries. The avian HEV associated with Hepatitis-Splenomegaly syndrome in chickens is genetically and antigenically related to mammalian HEV, and likely represents a new genus in the family. There exist three open reading frames in HEV genome: ORF1 encodes non-structural proteins, ORF2 encodes the capsid protein, and the ORF3 encodes a small phosphoprotein. ORF2 and ORF3 are translated from a single bicistronic mRNA, and overlap each other but neither overlaps ORF1. Due to the lack of an efficient cell culture system and a practical animal model for HEV, the mechanisms of HEV replication and pathogenesis are poorly understood. The recent identification and characterization of animal strains of HEV from pigs and chickens and the demonstrated ability of cross-species infection by these animal strains raise potential public health concerns for zoonotic HEV transmission. It has been shown that the genotypes 3 and 4 HEV strains from pigs can infect humans, and vice versa. Accumulating evidence indicated that hepatitis E is a zoonotic disease, and swine and perhaps other animal species are reservoirs for HEV. A vaccine against HEV is not yet available.
Hepatitis E virus (HEV) is a zoonotic pathogen of which pigs are reservoirs. To determine the presence of HEV RNA in commercial pig livers sold in local grocery stores in the USA, 127 packages of ...commercial pig liver were purchased and tested by a universal RT-PCR assay capable of detecting all four known HEV genotypes. Among the 127 livers tested, 14 were positive for HEV RNA. Sequence and phylogenetic analyses revealed that the 14 isolates all belonged to genotype 3. An animal study was subsequently conducted in pigs to determine whether the PCR-positive pig livers still contained infectious virus. The results showed that pigs inoculated with two of the three PCR-positive pig-liver homogenates became infected, as evidenced by the detection of faecal virus shedding, viraemia and seroconversion. The data demonstrated that commercial pig livers sold in grocery stores are contaminated by HEV and that the contaminating virus remains infectious, thus raising a public-health concern for food-borne HEV infection.
Hepatitis E virus (HEV), the causative agent of hepatitis E, belongs to the family Hepeviridae. At least four major genotypes of HEV have been recognized: genotypes 1 and 2 are restricted to humans ...and associated with epidemics in developing countries, whereas genotypes 3 and 4 are zoonotic and infect humans and several other animals in both developing and industrialized countries. Besides humans, strains of HEV have been genetically identified from swine, chickens, sika deer, mongeese, and rabbits. The genome of HEV consists of three open reading frames (ORFs): ORF1 codes for nonstructural proteins, ORF2 codes for capsid protein, and ORF3 codes for a small multifunctional protein. The ORF2 and ORF3 proteins are translated from a single bicistronic mRNA and overlap each other but neither overlaps ORF1. The recent determination of the 3D crystal structure of the HEV capsid protein should facilitate the development of vaccines and antivirals. The identification and characterization of animal strains of HEV from pigs and chickens and the demonstrated ability of cross‐species infection by swine HEV raise public health concerns for zoonosis. Accumulating evidence indicated that hepatitis E is a zoonotic disease and pigs and more likely other animal species are reservoirs for HEV. This article provides an overview of the recent advances in hepatitis E and its causative agent, including nomenclature and genomic organization, gene expression and functions, 3D structure of the virions, changing perspectives on higher mortality during pregnancy and chronic hepatitis E, animal reservoirs, zoonotic risk, food safety, and novel animal models.
Organic electronics is emerging for large-area applications such as photovoltaic cells, rollable displays or electronic paper. Its future development and integration will require a simple, low-power ...organic memory, that can be written, erased and readout electrically. Here we demonstrate a non-volatile memory in which the ferroelectric polarisation state of an organic tunnel barrier encodes the stored information and sets the readout tunnel current. We use high-sensitivity piezoresponse force microscopy to show that films as thin as one or two layers of ferroelectric poly(vinylidene fluoride) remain switchable with low voltages. Submicron junctions based on these films display tunnel electroresistance reaching 1,000% at room temperature that is driven by ferroelectric switching and explained by electrostatic effects in a direct tunnelling regime. Our findings provide a path to develop low-cost, large-scale arrays of organic ferroelectric tunnel junctions on silicon or flexible substrates.
Wild boars (Sus scrofa) are indigenous in many countries in the world. These free-living swine are known reservoirs for a number of viruses, bacteria and parasites that are transmissible to domestic ...animals and humans. Changes of human habitation to suburban areas, increased use of lands for agricultural purposes, increased hunting activities and consumption of wild boar meat have increased the chances of exposure of wild boars to domestic animals and humans. Wild boars can act as reservoirs for many important infectious diseases in domestic animals, such as classical swine fever, brucellosis and trichinellosis, and in humans, diseases such as hepatitis E, tuberculosis, leptospirosis and trichinellosis. For examples, wild boars are reservoirs for hepatitis E virus, and cluster cases of hepatitis E have been reported in Japan of humans who consumed wild boar meat. In Canada, an outbreak of trichinellosis was linked to the consumption of wild boar meat. The incidence of tuberculosis owing to Mycobacterium bovis has increased in wild boars, thus posing a potential concern for infections in livestock and humans. It has also been documented that six hunters contracted Brucella suis infections from wild swine in Florida. This article discusses the prevalence and risk of infectious agents in wild boars and their potential transmission to livestock and humans.
The wide band gap semiconductor Ga
2
O
3
has become an excellent UV detection material due to its suitable band gap, high crystalline quality and thermal stability. In this paper, the microstructure ...of Ga
2
O
3
with different thicknesses is characterized and the solar-blind detection performance of Ga
2
O
3
/p-Si heterojunctions are further investigated. XRD and UV–VIS demonstrate that Ga
2
O
3
sputtered for 20 min is amorphous with a band gap of 4.98 eV, as the sputtering time increases, Ga
2
O
3
grows along the (002) crystal plane and the band gap increases. XPS reveals that the lattice oxygen content in the Ga
2
O
3
increases with the sputtering time, however, the Ga
3+
content reaches a peak in Ga
2
O
3
sputtered for 1.5 h. And the increasing of the binding energy between Ga-O in Ga
2
O
3
/p-Si heterojunctions accelerates response speed. Electrical experiments show that the heterojunction consisting of sputtered 1.5 h Ga
2
O
3
and p-Si reaches a higher PDCR, with a value of 6684 at 5.7 V. Meanwhile, the rise and decay time of the heterojunction are 0.13 s and 0.14 s at 0 V, and the decay time gradually increases from 0.1 to 0.7 s with increasing the applied voltage. However, insertion of 20 nm Si-doped Ga
2
O
3
as a hole-blocking layer at the interface of p-Si and Ga
2
O
3
remarkably declines the decay time under various applied biases and causes no obvious damage to the photo current of the heterojunction.
The mechanical response of amorphous silica (or silica glass) under hydrostatic compression for very high pressures up to 25GPa is modelled via an elastic–plastic constitutive equation (continuum ...mechanics framework). The material parameters appearing in the theory have been estimated from the ex situ experimental data of Rouxel et al. Rouxel T, Ji H, Guin JP, Augereau F, Rufflé B. J Appl Phys 2010;107(9):094903. The model is shown to capture the major features of the pressure–volume response changes from the in situ experimental work of Sato and Funamori Sato T, Funamori N. Phys Rev Lett 2008;101:255502 and Wakabayashi et al. Wakabayashi D, Funamori N, Sato T, Taniguchi T. Phys Rev B 2011;84(14):144103. In particular, the saturation of densification, the increase in elasticity parameters (bulk, shear and Young’s moduli) and Poisson’s ratio are found to be key parameters of the model.
Precipitation of relativistic electrons into the Earth's atmosphere regulates the outer radiation belt fluxes and contributes to magnetosphere‐atmosphere coupling. One of the main drivers of such ...precipitation is electron scattering by whistler‐mode waves. Such waves typically originate at the equator, where they can resonate with and scatter sub‐relativistic (tens to a few hundred keV) electrons. However, they can occasionally propagate far away from the equator along field lines, reaching middle latitudes, where they can resonate with and scatter relativistic (>500 keV) electrons. Such a propagation is typical for the dayside, but statistically has not been found on the nightside where the waves are quickly damped along their propagation due to Landau damping. Here we explore two events of relativistic electron precipitation from low‐altitude observations on the nightside. Combining measurements of whistler‐mode waves from ground observatories, relativistic electron precipitation from low‐altitude satellites, total electron content maps from GPS receivers, and magnetic field and electron flux from equatorial satellites, we show wave ducting by plasma density gradients is the possible channel that allows the waves to reach middle latitudes and scatter relativistic electrons. We suggest that both whistler‐mode wave generation and ducting can be driven by equatorial mesoscale (with spatial scales of about one Earth radius) transient structures during nightside injections. We also compare these nightside events with observations of ducted waves and relativistic electron precipitation at the dayside, where wave generation and ducting are driven by ultra‐low‐frequency waves. This study demonstrates the potential importance of mesoscale transients in relativistic electron precipitation, but does not however unequivocally establish that ducted whistler‐mode waves are the primary cause of the observed electron precipitation.
Key Points
We report night‐side relativistic electron precipitation associated with whistler‐mode waves
Wave ducting is one possible explanation of the observed precipitating electron spectra
We examine the role of plasma injections and foreshock transients in relativistic electron losses
Hepatitis E virus (HEV) is transmitted by the fecal–oral route and causes sporadic and epidemic forms of acute hepatitis. Large waterborne HEV epidemics have been documented exclusively in developing ...countries. At least four major genotypes of HEV have been reported worldwide: genotype 1 (found primarily in Asian countries), genotype 2 (isolated from a single outbreak in Mexico), genotype 3 (identified in swine and humans in the United States and many other countries), and genotype 4 (identified in humans, swine and other animals in Asia). To better detect and quantitate different HEV strains that may be present in clinical and environmental samples, we developed a rapid and sensitive real-time RT-PCR assay for the detection of HEV RNA. Primers and probes for the real-time RT-PCR were selected based on the multiple sequence alignments of 27 sequences of the ORF3 region. Thirteen HEV isolates representing genotypes 1–4 were used to standardize the real-time RT-PCR assay. The TaqMan
® assay detected as few as four genome equivalent (GE) copies of HEV plasmid DNA and detected as low as 0.12 50% pig infectious dose (PID
50) of swine HEV. Different concentrations of swine HEV (120–1.2
PID
50) spiked into a surface water concentrate were detected in the real-time RT-PCR assay. This is the first reporting of a broadly reactive TaqMan
® RT-PCR assay for the detection of HEV in clinical and environmental samples.
Gamma-aminobutyric acid (GABA) is a non-protein amino acid that accumulates in a number of plant species under various environmental stresses. In this paper, the ability of applied GABA for the ...alleviation of NaCl stress was investigated in view of growth parameters, gas exchange, photosynthetic pigments, chlorophyll fluorescence, activities of antioxidant enzymes, malondialdehyde (MDA) content, and electrolyte conductivity (REC) in wheat seedlings. Germination rate and shoot dry mass decreased with an increasing NaCl concentration and this decrease was less pronounced when 0.5 mM GABA was applied. In the NaCl-treated seedlings, exogenous GABA partially enhanced photosynthetic capacity and antioxidant enzyme activities and decreased MDA content and REC. Therefore, GABA reduced the impact of salinity on the wheat seedlings.
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