Marine methane hydrate in sands has huge potential as an unconventional gas resource; however, no field test of their production potential had been conducted. Here, we report the world’s first ...offshore methane hydrate production test conducted at the eastern Nankai Trough and show key findings toward future commercial production. Geological analysis indicates that hydrate saturation reaches 80% and permeability in the presence of hydrate ranges from 0.01 to 10 mdarcies. Permeable (1–10 mdarcies) highly hydrate-saturated layers enable depressurization-induced gas production of approximately 20,000 Sm3/D with water of 200 m3/D. Numerical analysis reveals that the dissociation zone expands laterally 25 m at the front after 6 days. Gas rate is expected to increase with time, owing to the expansion of the dissociation zone. It is found that permeable highly hydrate-saturated layers increase the gas–water ratio of the production fluid. The identification of such layers is critically important to increase the energy efficiency and the technical feasibility of depressurization-induced gas production from hydrate reservoirs.
The catalytic center of photosynthetic water oxidation, the Mn4CaO5 cluster, is assembled in photosystem II (PSII) through a light-driven process called photoactivation, whose mechanism remains ...elusive. Here, we used rapid-scan time-resolved Fourier transform infrared (FTIR) spectroscopy combined with the attenuated total reflection (ATR) technique to monitor the photoactivation process. Rapid-scan ATR-FTIR spectra of apo-PSII with Mn2+ upon flash illumination showed spectral features typical of carboxylate stretching vibrations, which were attributed to two carboxylate ligands, D1-D170 and D1-E189, by quantum chemical calculations. The FTIR signal decayed with a time constant of ∼0.7 s, showing that the subsequent “dark rearrangement” step occurred with a low quantum yield and Mn3+ ions were mostly released during this decay. Simulation of the kinetic process provided a slow intrinsic rate of the dark rearrangement, which was attributed to a large protein conformational change. The photoassembly mechanism of the Mn4CaO5 cluster is proposed based on these findings.
The spike (S) protein of Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) binds to a host cell receptor which facilitates viral entry. A polybasic motif detected at the cleavage site of ...the S protein has been shown to broaden the cell tropism and transmissibility of the virus. Here we examine the properties of SARS-CoV-2 variants with mutations at the S protein cleavage site that undergo inefficient proteolytic cleavage. Virus variants with S gene mutations generated smaller plaques and exhibited a more limited range of cell tropism compared to the wild-type strain. These alterations were shown to result from their inability to utilize the entry pathway involving direct fusion mediated by the host type II transmembrane serine protease, TMPRSS2. Notably, viruses with S gene mutations emerged rapidly and became the dominant SARS-CoV-2 variants in TMPRSS2-deficient cells including Vero cells. Our study demonstrated that the S protein polybasic cleavage motif is a critical factor underlying SARS-CoV-2 entry and cell tropism. As such, researchers should be alert to the possibility of de novo S gene mutations emerging in tissue-culture propagated virus strains.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Three novel viruses were detected from Japanese persimmon ‘Reigyoku’ (
Diospyros kaki
), which grows poorly when top-grafted onto some interstocks. The genomic characterization and the phylogenetic ...analysis of these viruses indicated that they are likely new members of the genera
Ampelovirus
,
Polerovirus
, and
Waikavirus
, tentatively named Persimmon ampelovirus (PAmpV), Persimmon polerovirus (PPolV), and Persimmon waikavirus (PWaiV). The alignment of two PAmpV variants with
Plum bark necrosis stem pitting–associated virus
isolates had 72.5%–79.0% amino acid sequence identities with RNA-dependent RNA polymerase, 71.6%–79.2% with a heat shock protein 70 homolog, and 66.2%–69.8% with coat protein, respectively. Two PPolV variants showed the highest amino acid sequence identities (46.6%) with the P1–P2 fusion protein of Brassica yellows virus. PWaiV had the highest amino acid sequence identity (41.9%) with the conserved domain between proteinase and polymerase of
Rice tungro spherical virus
. Reverse-transcription and polymerase chain reaction detected Persimmon virus A, Apple crinkle fruit viroid, and
Citrus viroid VI
from the mother clone with good growth, and PAmpV, PPolV, and Persimmon latent viroid (PLVd) additionally from 20 trees with poor growth. PAmpV, PPolV, and PLVd were detected from four, 10, and 10 of 14 trees with good growth, respectively, and the grafting of budwood harboring these three pathogens caused significant stunt in mother clones.
Cap-dependent endonuclease (CEN) resides in the PA subunit of the influenza virus and mediates the critical “cap-snatching” step of viral RNA transcription, which is considered to be a promising ...anti-influenza target. Here, we describe in vitro characterization of a novel CEN inhibitor, baloxavir acid (BXA), the active form of baloxavir marboxil (BXM). BXA inhibits viral RNA transcription via selective inhibition of CEN activity in enzymatic assays, and inhibits viral replication in infected cells without cytotoxicity in cytopathic effect assays. The antiviral activity of BXA is also confirmed in yield reduction assays with seasonal type A and B viruses, including neuraminidase inhibitor-resistant strains. Furthermore, BXA shows broad potency against various subtypes of influenza A viruses (H1N2, H5N1, H5N2, H5N6, H7N9 and H9N2). Additionally, serial passages of the viruses in the presence of BXA result in isolation of PA/I38T variants with reduced BXA susceptibility. Phenotypic and genotypic analyses with reverse genetics demonstrate the mechanism of BXA action via CEN inhibition in infected cells. These results reveal the in vitro characteristics of BXA and support clinical use of BXM to treat influenza.
•In vitro characterization of a CEN inhibitor baloxavir acid (BXA), the active form of baloxavir marboxil, was conducted.•BXA selectively blocks CEN activity of the viral polymerase complex in enzymatic assay.•BXA exhibits potent and broad activities against various types of influenza viruses.•In vitro drug resistant isolation study supports BXA targets CEN of PA subunit.
In Japan, few grape cultivars related to Vitis vinifera existed 200 years ago, on account of Japan’s high rainfall. Many V. labruscana and vinifera cultivars were introduced to Japan in the 19th ...century. Labruscana was grown instead of vinifera, mainly because of severe disease problems and a high incidence of berry cracking. Grape breeding for table use started in the 20th century, with the goal of combining the berry quality of vinifera with the ease of cultivation of labruscana. By 1945, three strategies were used: 1) crossing among introduced diploid vinifera and vinifera-related cultivars of Japanese origin, 2) interspecific crossing in tetraploid cultivars, and 3) interspecific crossing in diploid cultivars, resulting in ‘Neo Muscat’, ‘Kyoho’, and ‘Muscat Bailey A’. Later, tetraploid interspecific crossing over generations developed many ‘Kyoho’-related cultivars, including ‘Pione’, many of which have large berries, intermediate flesh texture between the two species, a labruscan or neutral flavor, and moderate disease resistance. Interspecific diploid crossing over generations developed ‘Shine Muscat’ in 2006, with large berries, crispy flesh, a muscat flavor, no cracking, seedless fruit by gibberellin application, and moderate resistance to downy mildew and ripe rot.
Background:Insomnia is associated with incident heart failure (HF), but the clinical significance and impact of insomnia on HF remain unclear.Methods and Results:Consecutive 1,011 patients admitted ...for HF were divided into 2 groups according to the presence of insomnia: HF with insomnia (insomnia group, n=519) and HF without insomnia (non-insomnia group, n=492). We compared (1) cardiac event rates including cardiac death and worsening HF; and (2) underlying clinical background including laboratory data, echocardiographic data, and cardiopulmonary exercise test between the 2 groups. On Kaplan-Meier analysis, cardiac event rate was significantly higher in the insomnia group than in the non-insomnia group (39.1 vs. 23.4%, P<0.001). The insomnia group, as compared with the non-insomnia group, had (1) higher plasma renin activity (P=0.042), renin concentration (P=0.007), and aldosterone (P=0.047); (2) lower peak V̇O2(14.9 vs. 16.3 ml/kg/min, P=0.002) and higher V̇E/V̇CO2slope (36.0 vs. 33.5, P=0.001); and (3) similar B-type natriuretic peptide and left ventricular ejection fraction. Importantly, on multivariate Cox proportional hazard analysis after adjusting for potential confounding factors, insomnia was an independent predictor of cardiac events in HF patients (hazard ratio, 1.899; P<0.001).Conclusions:Insomnia is an independent predictor of cardiac events in HF patients. HF patients with insomnia have activated renin-angiotensin-aldosterone system and lower exercise capacity. (Circ J 2016; 80: 1571–1577)
Oriental persimmon (Diospyros kaki) originated in Eastern Asia, and many indigenous cultivars have been developed in China, Japan, and Korea. These cultivars are classified into four groups based on ...their natural astringency loss on the tree and seed formation: pollination-constant non-astringent (PCNA), pollination-variant non-astringent (PVNA), pollination-constant astringent (PCA), and pollination-variant astringent (PVA). PCNA is the most desirable type because the fruit can be eaten without any postharvest treatment; therefore, one of the goals of our persimmon breeding programs is to release superior PCNA cultivars. The PCNA genotype is recessive to the other three non-PCNA genotypes, and PCNA-type F1 offspring are obtained exclusively from crosses among PCNA genotypes. Moreover, the number of superior PCNA cross-parents have been limited. In the late 1980s, inbreeding depression became obvious, especially in terms of fruit size, tree vigor, and productivity. To mitigate the inbreeding, a backcross program using PCNA (non-PCNA × PCNA) × PCNA was started in 1990. This process, however, was inefficient because only 15% of the offspring were PCNA, and all offspring had to be grown to the fruiting stage. Therefore, molecular markers linked to the PCNA locus were developed for discriminating PCNA offspring. A molecular marker linked to Chinese PCNA has also been developed.
Although the spread of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has resulted in a worldwide pandemic, there are currently no virus-specific drugs that are fully effective against ...SARS-CoV-2. Only a limited number of human-derived cells are capable of supporting SARS-CoV-2 replication and the infectivity of SARS-CoV-2 in these cells remains poor. In contrast, monkey-derived Vero cells are highly susceptibility to infection with SARS-CoV-2, although they are not suitable for the study of antiviral effects by small molecules due to their limited capacity to metabolize drugs compared to human-derived cells. In this study, our goal was to generate a virus-susceptible human cell line that would be useful for the identification and testing of candidate drugs. Towards this end, we stably transfected human lung-derived MRC5 cells with a lentiviral vector encoding angiotensin-converting enzyme 2 (ACE2), the cellular receptor for SARS-CoV-2. Our results revealed that SARS-CoV-2 replicates efficiently in MRC5/ACE2 cells. Furthermore, viral RNA replication and progeny virus production were significantly reduced in response to administration of the replication inhibitor, remdesivir, in MRC5/ACE2 cells compared with Vero cells. We conclude that the MRC5/ACE2 cells will be important in developing specific anti-viral therapeutics and will assist in vaccine development to combat SARS-CoV-2 infections.
•Light and appropriate temperature increase anthocyanin content in harvested grapes.•Red- to purple-skinned accessions are suitable for increasing anthocyanins by our method.•Optimal temperature ...range increases anthocyanins without a decline in fruit quality.•Light and appropriate temperature increase the expression of anthocyanin-related genes.
Grape skin color is important because consumers generally prefer well pigmented grapes, and the high marketability of these fruit is important for farmers. Poor coloration, caused mainly by high temperatures during maturation, is a common problem. We investigated the effect of 7- to 9-day light irradiation and temperature treatment at 10, 15, 20, and 25 °C on anthocyanin accumulation in harvested berries of grape accessions. Anthocyanin accumulation of berries, mainly in red- to purple-skinned accessions, could be increased by combining postharvest light irradiation (white light + UV light, or blue LED light) with 15–25 °C treatments. Our data suggest that the optimal temperature (15–20 °C) improves anthocyanin accumulation without a decline in titratable acidity and berry weight. The coordinated induction of anthocyanin biosynthesis–related genes under these conditions might explain the accumulation of anthocyanins. These findings will help us to develop techniques for stable production of well colored grapes.
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