The solid solution between CaSiO3 and MgSiO3 perovskites is an important control on the properties of the lower mantle but the effect of one of the most important impurity elements (iron) on this ...solution is largely unknown. Using density functional theory (DFT), ferrous iron's influence on the reciprocal solubility of MgSiO3 and CaSiO3 perovskite (forming a single Ca-Mg mixed perovskite phase) was calculated under pressures and temperatures of 25-125 GPa and 0-3000 K, respectively. Except at iron-rich conditions, ferrous iron preferentially partitions into the mixed perovskite phase over bridgmanite. This is a small effect (partitioning coefficient KD ∼0.25-1), however, when compared to the partitioning of ferrous iron to ferropericlase, which rules out perovskite phase mixing as a mechanism for creating iron-rich regions in the mantle. Iron increases the miscibility of Ca and Mg perovskite phases and reduces the temperature at which the two perovskite phases mix but this effect is highly nonlinear. We find that for a pyrolytic mantle Ca% = 12.5 where Ca% = Ca/(Ca+Mg) a perovskite ferrous iron concentration of ∼13% leads to the lowest mixing temperature and the highest miscibility. With this composition, 1% ferrous iron in a pyrolytic composition would lead to mixing at ∼120 GPa along the geothermal gradient, and 6.25% ferrous iron leads to mixing at ∼115 GPa and 13% ∼110 GPa. At high iron concentrations, Fe starts to impair miscibility, with 25% ferrous iron leading to mixing at ∼120 GPa. Thus, in normal pyrolytic mantle, iron could induce a small amount of Ca-pv and Mg-pv mixing near the D" layer but it generally partitions to ferropericlase instead and does not impact mixing. Extremely iron rich parts of the lower mantle such as ULVZs or the CMB (potentially) are also not a likely source of phase mixed perovskites due to the nonlinear effect of ferrous iron on phase mixing.
Kawasaki disease (KD) is the most common cause of acquired heart disease in children in developed countries. Although functional and phenotypic changes of immune cells have been reported, a global ...understanding of immune responses underlying acute KD is unclear. Here, using single-cell RNA sequencing, we profile peripheral blood mononuclear cells from seven patients with acute KD before and after intravenous immunoglobulin therapy and from three age-matched healthy controls. The most differentially expressed genes are identified in monocytes, with high expression of pro-inflammatory mediators, immunoglobulin receptors and low expression of MHC class II genes in acute KD. Single-cell RNA sequencing and flow cytometry analyses, of cells from an additional 16 KD patients, show that although the percentage of total B cells is substantially decreased after therapy, the percentage of plasma cells among the B cells is significantly increased. The percentage of CD8
T cells is decreased in acute KD, notably effector memory CD8
T cells compared with healthy controls. Oligoclonal expansions of both B cell receptors and T cell receptors are observed after therapy. We identify biological processes potentially underlying the changes of each cell type. The single-cell landscape of both innate and adaptive immune responses provides insights into pathogenesis and therapy of KD.
Long-term exposure to high levels of arsenic has been documented to induce skin and liver damage, affecting hundreds of millions of people. While arsenic-induced skin and liver damage and trace ...element alterations have been studied, their correlations and risks have not been explained. Based on the above premise, this study included a total of 172 subjects from a coal-burning arsenic poisoning area. The levels of 18 trace elements in hair and six liver function indices in serum were detected, and the associations between and risks of trace elements related to skin and liver damage were analyzed. Finally, the receiver operating characteristic (ROC) curve and areas under the curve (AUC) were used to analyze the diagnostic values of certain trace elements for arsenic-induced skin and liver damage. The results found that a decrease in Se was a risk factor for arsenic-induced skin and liver damage (OR = 8.33 and 1.92, respectively). Furthermore, increases in Al and V were risk factors for arsenic-induced skin damage (OR = 1.05) and liver damage (OR = 13.16), respectively. In addition, the results found that Se and Al possessed certain diagnostic values for arsenic-induced skin damage (AUC = 0.93, 0.80), that Se possessed a diagnostic value for liver damage (AUC = 0.93), and that the combination of Se and Al increased the diagnostic value for skin damage (AUC = 0.96). This study provides an important research basis for further understanding the reasons for arsenic-induced skin and liver damage, for screening and identifying candidate diagnostic biomarkers, and for improving prevention and control strategies for arsenism.
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•Decreased Se was a risk factor for arsenic-induced skin and liver damage.•Increased Al and V were risk factors for arsenic-induced skin and liver damage, respectively.•Se and Al had diagnostic value for arsenic-induced skin and liver damage.
We aimed to clarify the epidemiologic and clinical importance of evolutionary events that occurred in carbapenem-resistant Klebsiella pneumoniae (CRKP). We collected 203 CRKP causing bloodstream ...infections in a tertiary hospital in China during 2013-2017. We detected a subclonal shift in the dominant clone sequence type (ST) 11 CRKP in which the previously prevalent capsular loci (KL) 47 had been replaced by KL64 since 2016. Patients infected with ST11-KL64 CRKP had a significantly higher 30-day mortality rate than other CRKP-infected patients. Enhanced virulence was further evidenced by phenotypic tests. Phylogenetic reconstruction demonstrated that ST11-KL64 is derived from an ST11-KL47-like ancestor through recombination. We identified a pLVPK-like virulence plasmid carrying rmpA and peg-344 in ST11-KL64 exclusively from 2016 onward. The pLVPK-like-positive ST11-KL64 isolates exhibited enhanced environmental survival. Retrospective screening of a national collection identified ST11-KL64 in multiple regions. Targeted surveillance of this high-risk CRKP clone is urgently needed.
Aim
Selenium (Se) can induce stress in plants. Our main purpose is to assess the effect of a biostimulant, based on hetero-polyoxometalates mixed with humic acids, on Se bio-fortified wheat plants. ...Secondly, to evaluate a possible modification of the Se species in the plant tissues and to investigate the response of phytohormones.
Method
Wheat plants were grown hydroponically and exposed to either selenite (Se(IV)), selenate (Se(VI)) or a mixture of both species (Se(MIX)) in the presence or absence of the biostimulant (foliar, FA; or root application, RA). Biomass, mineral nutrient concentration, phytohormones and Se speciation were investigated.
Results
The biostimulant FA did not modify the plant biomass but RA significantly increased the root biomass in all treatments as well as the shoot biomass of plants exposed to Se(VI) and Se(MIX) even when both modes of application caused a severe reduction of IAA levels in shoots. The biostimulant accelerated the translocation of Se from roots to shoots in the presence of Se(VI) and Se(MIX), and it only had a noticeable influence on the Se speciation in roots, but not significant in shoots. X-ray absorption spectroscopy allowed to identify organic Se as the main Se species formed in the shoots. The biostimulant has a mild effect on the Se speciation.
Conclusion
The biostimulant has a remarkable influence on both the uptake and accumulation of certain mineral nutrients and the plant metabolism by increasing the biomass under Se exposure. This indicates the potential of this biostimulant that also will prevent the possible Se-induced plant stress.
Previous research has showed that nonproteolytic Levilactobacillus brevis 145 (L) in coculture with Streptococcus thermophilus 1275 (S), not Lactobacillus delbrueckii ssp. bulgaricus (Lbu), was able ...to produce γ-aminobutyric acid (GABA) during milk fermentation in the presence of monosodium glutamate (MSG). It was assumed that differences of casein hydrolysis patterns between Strep. thermophilus 1275 and L. bulgaricus caused the phenomenon. Moreover, the GABA content was low and residual MSG was high in SL-fermented milk. In our research, comparison of peptide profiles determined by liquid chromatography/tandem mass spectrometry showed that αS2-casein, β-casein, and κ-casein degradation by L. bulgaricus and Strep. thermophilus varied. Importantly, the peptide number in the L and Lbu coculture group increased compared with the Lbu monoculture group, whereas the peptide number in the SL coculture group decreased in comparison with S monoculture group, suggesting that L. bulgaricus was not able to provide peptides for the growth of Lb. brevis 145. Furthermore, we found that after supplementation with cysteine (50 mg/L) during milk fermentation by SL, 10 g/L MSG was converted into 4.8 g/L GABA with a minimum level of residual MSG, viable cell counts of Lb. brevis and lactic acid production were increased, and the casein hydrolysis pattern was not influenced. Moreover, sulfhydryl group-containing chemicals including cystine, reduced glutathione, and oxidized glutathione showed effects similar to that of cysteine in improving GABA production. Finally, when L. bulgaricus YIB2 was combined with SL, supplementation of cysteine was also able to significantly improve GABA production.
The cultivation of
Agaricus bisporus
with compost made from wheat (
Triticum aestivum
L.), rice (
Oryza sativa
L
.
), and reed (
Phragmites australis
Trin
.
) straw was investigated. Straw ...degradation was analyzed at the microscopic level, and the corresponding changes in the breakdown of different lignocellulose components during different phases of composting and mushroom production helped in understanding the yield-limiting factors of using different straws to grow mushrooms. The wheat straw compost resulted in the highest mushroom production and had the highest bioconversion efficiency. The rice straw was limited by the softer texture, which resulted in low-porosity and overdecomposed compost in the composting process and decreased the amount of available lignocellulose during mycelial growth. Although reed straw had the largest carbon resources, its utilization rate was the lowest. The hard structure, low water holding capacity, and high porosity increased the recalcitrance of reed straw to degradation and prolonged the composting time, which resulted in large N and C losses and an increased C/N ratio. Moreover, reed straw failed to transform into “ready-to-consume C” in composting. Therefore, a high C/N ratio and deficiency of available nutrition decreased the utilization efficiency of the lignocellulosic components by
A. bisporus
during mycelial colonization and mushroom production. The investigation revealed that degradability by and availability to microbiota and
A. bisporus
seemed to be the overriding factors for optimizing the composting process with different straw types.
Key points
• The physical structure of compost has a significant influence on the composting process.
• Degradability and availability are key factors in compost quality evaluation.
• Lignocellulose utilization efficiency positively correlated with mushroom yield.
Graphical abstract
There has been an increasing incidence of delirium which causing long-term consequences of life. This paper summarized the application status quo of tools for assessing delirium at home and abroad, ...in order to provide reference for standardized evaluation and precise treatment of delirium. (谵妄在临床发生率高, 远期不良后果严重。本研究就目前国内外谵妄工具的使用情况进行总结和分析, 以期为进一步标准化、精准化谵妄评估到治疗提供依据。)
Data accuracy is essential for reliable and valid altmetrics analysis. Although Twitter and Facebook altmetrics data are widely used for scholarly communication and scientific evaluation, few studies ...have tapped into their accuracy issue. Based on content analysis of random sample records over two phases, this study has investigated and compared the accuracy of Twitter and Facebook altmetrics data. Major conclusions are drawn as follows. (1) Three error types were identified from the altmetric data provider and six error types were identified from the altmetric data aggregator. Twitter and Facebook have shared most of the error types except for minor differences in the sub-categories. (2) The overall error rate is substantially high, being 17% and 32% for Twitter and Facebook respectively in April, 2019. However, except for publication date error and posting date error, the percentage of the other error types is relatively low (being around 3%). (3) The percentage of error types related to the dynamic nature of Twitter and Facebook is increasing over time, while percentage of error types concerning the bibliographic data is decreasing over time. (4) The error types are either “high seriousness low percentage” or “low seriousness high percentage”, therefore, they would probably not bring significant negative influence. (5) Underlying reasons of these error types are various. They could be attributable to the Twitter (or Facebook) user, Twitter (or Facebook) platform, altmetric database, as well as the third-party data provider. These results suggest that Twitter and Facebook altmetrics data in the Altmetric database are reliable on the whole, although there is still space for further improvement.
•Low Hg contents in metamorphic rocks support loss of Hg during metamorphism.•Similar Δ199Hg values between the equivalent un- and metamorphosed sedimentary rocks.•No significant Hg-MIF during the ...metamorphism.•Robust Hg-MIF signals for tracing the material cycling.
Mercury isotopes undergo unique mass-independent fractionation (MIF) during photochemical processes on Earth's surface. Studies have observed pronounced Hg-MIF signals in sedimentary and magmatic rocks, suggesting recycling of Hg from Earth's surface systems into the lithosphere via sedimentation and magmatism. However, the isotopic signature of Hg in metamorphic rocks and the geochemical fate of Hg during metamorphism remain unclear. Precambrian basements are important components of cratons or orogenic belts on Earth. Here, we study the Hg concentration and isotopic composition of Precambrian metamorphic and sedimentary rocks from the eastern Central Asian Orogenic Belt, and North and South China cratons. Metamorphic rocks show much lower Hg contents (0.21–7.8 ppb) than sedimentary rocks (2.6–694 ppb), indicating a substantial loss of Hg during metamorphism. The lack of correlation between δ202Hg values (–2.41 to 0.18‰) and metamorphic grades indicates no systematic mass-dependent fractionation (MDF) of Hg isotopes during metamorphism. The Δ199Hg/Δ201Hg ratios of ∼ 1.0 for both metamorphic and sedimentary rocks indicate Hg was sourced from Earth's surface systems. The coupling of Hg-MIF signals between the metasedimentary rocks and the sedimentary settings of their protolith suggests no Hg-MIF during metamorphism. The negative Δ199Hg values (–0.30 to –0.02‰) in the Precambrian coastal sedimentary rocks imply the input of Hg into coastal regions via soil erosion. The positive Δ199Hg values (0.06 to 0.31‰) in the Precambrian marine sedimentary rocks suggest deposition of atmospheric Hg(II) to open oceans via wet deposition. The lack of significant Hg-MIF during metamorphism and other underground geological processes shows that Hg-MIF signals can work as a reliable tracer for indicating material cycling in Earth's interior.
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