Arc magmas, a major contributor to continental crust growth, are thought to be more oxidized than mid-ocean ridge basalts as reflected by an enrichment in ferric iron relative to ferrous iron. But ...how arc magmas become oxidized is hotly debated. It is acknowledged that the fractionation of common Fe-rich phases (e.g., amphibole) may change the Fe valence of the derivative melt. Amphibole has Fe-rich compositions commonly found in arc systems. We present high-precision (±0.01%) Fe valence data of amphibole and cumulates from the Kohistan arc determined by Mössbauer spectroscopy and bulk cumulate Fe3+/ΣFe ratios by wet chemistry. We evaluate the Fe3+/ΣFe trend of Fe-rich amphibole during arc magma fractionation. Our results show that bulk Fe3+/ΣFe ratio of cumulates in mature island arc settings is mainly controlled by amphibole due to its abundance and decreases (from 0.4 to 0.2) with decreasing Mg# as Fe3+/ΣFe ratios decrease in amphibole (from 0.35 to 0.2). Our modeling suggests that amphibole fractionation from parental arc magmas to Fe3+/ΣFe above 0.2 may lead to an increase in Fe3+/ΣFe ratios of middle-late stage residual melts by 0.1-0.3, and the partitioning of ferrous Fe into amphibole increases with the evolution of arc magmas. Our findings highlight the importance of petrological processes in the magma that contribute to the production of fertile arc crust.
Selective laser melting (SLM) is among the best technologies to realize near-net forming of metal parts. The process involves the matching of various process parameters to achieve the full density of ...the products. This study was dedicated to understanding the influence of laser energy density and various scanning strategies on the formability of the SLM-fabricated 24CrNiMo specimens, which were characterized in terms of densification, surface quality and microstructure. Firstly, the experiments focused on the adjustment of laser energy density, which was aimed at determining an optimal parameter for the 24CrNiMo steel with the minimum porosity and optimum microstructure. The experimental results illustrated that the relative density of the specimen was promoted to 99.14% and its surface roughness decreased to 19.002 μm by applying the energy density of 56.00 J/mm3. In addition, the microstructure was mainly composed of lower bainite with high strength, and the irregularly oriented grains ensured the homogeneity of the specimen. Subsequently, the residual stress distribution and warping deformation of the specimens prepared by various scanning strategies were thoroughly analyzed to clarify the most suitable strategy for 24CrNiMo steel. It was observed that the specimen prepared by orthogonal scanning strategy exhibited no obvious defects, relatively stable residual stress distribution and optimal surface quality, which could be regarded as a reference for preparing high-quality 24CrNiMo steel via SLM.
•Selective laser melted 24CrNiMo steel was prepared by various process parameters.•The increasing energy density would help promote the formability of 24CrNiMo steel.•Orthogonal scanning strategy would help reduce the accumulation of residual stress.•The optimum process parameters were determined through microstructure analysis.
Abiotic stresses, including drought and salinity, trigger a complex osmotic-stress and abscisic acid (ABA) signal transduction network. The core ABA signalling components are snf1-related protein ...kinase2s (SnRK2s), which are activated by ABA-triggered inhibition of type-2C protein-phosphatases (PP2Cs). SnRK2 kinases are also activated by a rapid, largely unknown, ABA-independent osmotic-stress signalling pathway. Here, through a combination of a redundancy-circumventing genetic screen and biochemical analyses, we have identified functionally-redundant MAPKK-kinases (M3Ks) that are necessary for activation of SnRK2 kinases. These M3Ks phosphorylate a specific SnRK2/OST1 site, which is indispensable for ABA-induced reactivation of PP2C-dephosphorylated SnRK2 kinases. ABA-triggered SnRK2 activation, transcription factor phosphorylation and SLAC1 activation require these M3Ks in vitro and in plants. M3K triple knock-out plants show reduced ABA sensitivity and strongly impaired rapid osmotic-stress-induced SnRK2 activation. These findings demonstrate that this M3K clade is required for ABA- and osmotic-stress-activation of SnRK2 kinases, enabling robust ABA and osmotic stress signal transduction.
Water deficit strongly affects crop productivity. Plants control water loss and CO2 uptake by regulating the aperture of the stomatal pores within the leaf epidermis. Stomata aperture is regulated by ...the two guard cells forming the pore and changing their size in response to ion uptake and release. While our knowledge about potassium and chloride fluxes across the plasma membrane of guard cells is advanced, little is known about fluxes across the vacuolar membrane. Here we present the molecular identification of the long-sought-after vacuolar chloride channel. AtALMT9 is a chloride channel activated by physiological concentrations of cytosolic malate. Single-channel measurements demonstrate that this activation is due to a malate-dependent increase in the channel open probability. Arabidopsis thaliana atalmt9 knockout mutants exhibited impaired stomatal opening and wilt more slowly than the wild type. Our findings show that AtALMT9 is a vacuolar chloride channel having a major role in controlling stomata aperture.
Abstract
In-situ bioprinting is attractive for directly depositing the therapy bioink at the defective organs to repair them, especially for occupations such as soldiers, athletes, and drivers who ...can be injured in emergency. However, traditional bioink displays obvious limitations in its complex operation environments. Here, we design a bioconcrete bioink with electrosprayed cell-laden microgels as the aggregate and gelatin methacryloyl (GelMA) precursor solution as the cement. Promising printability is guaranteed with a wide temperature range benefiting from robust rheological properties of photocrosslinked microgel aggregate and fluidity of GelMA cement. Composite components simultaneously self-adapt to biocompatibility and different tissue mechanical microenvironment. Strong binding on tissue-hydrogel interface is achieved by hydrogen bonds and friction when the cement is photocrosslinked. This bioink owns good portability and can be easily prepared in urgent accidents. Meanwhile, microgels can be cultured to mini tissues and then mixed as bioink aggregates, indicating our bioconcrete can be functionalized faster than normal bioinks. The cranial defects repair results verify the superiority of this bioink and its potential in clinical settings required in in-situ treatment.
Supramolecular self‐assembly stands for the spontaneous aggregation of small organic compounds or polymers into ordered structures at any scale. When being induced by inherent molecular chiral ...centers or ambient asymmetric factors, asymmetric spatial arrangement between building units shall occur, which is defined as supramolecular chirality. Except for molecular design, utilizing external stimulus factors to tune supramolecular chirality is a promising approach. In this Concept article, we particularly discuss the important role of solvents in manipulating the chirality of self‐assembled systems. The impact of solvents on the chirality is generally based on three properties of solvents, i.e., chirality, polarity, and active coassembly with building blocks. Molecular self‐assembly in chiral solvents could undergo the chirality transfer, exhibiting a chiral induction effect. Solvent polarity often determines intermolecular orientation. As a consequence, those building blocks with both polar and apolar segments might change their chirality depending on the solvent polarity. We elaborate the active participation of solvent molecules into ordered structures together with building blocks, where solvents and building blocks exhibit a coassembly manner. By specific treatments such as heating and cooling, solvents could be released or re‐entrapped, allowing a smart control over supramolecular chirality. The solvent effect in manipulating two‐dimensional chiral self‐assemblies is then discussed. The perspective and future development in this research field are presented at last.
Soft materials: The important role of solvents in manipulating the chirality of self‐assembled systems is discussed in this Concept article. Molecular self‐assembly in specific solvents might undergo the chirality transfer, exhibiting a chiral induction effect (see scheme).
Abstract
Sulfide-rich hydrous arc cumulates in the lower crust are considered a likely source for porphyry Cu-forming magmas in post-subduction settings. However, it remains controversial whether or ...not post-subduction porphyry Cu magmas can be produced by partial melting of lower crustal arc cumulates. Here we performed detailed petrographic and geochemical studies on exhumed lower to middle crustal cumulates from the Gangdese and Kohistan arc sections, and then conducted partial melting experiments of the Gangdese sulfide-rich lithologies at 1.5 GPa and 800°C–1150°C using a piston cylinder press. Both the Gangdese and the Kohistan arc-root samples formed as cumulates in the lower to middle crust, but the Kohistan samples were subsequently brought into the garnet stability field during the India–Eurasia continental collision. Most of the Gangdese samples contain relatively high abundances of magmatic sulfides preserved in the form of Cu-poor monosulfide solid solution. In contrast, most of the Kohistan samples contain very low abundances of Cu-rich sulfides preserved as inclusions in garnet, probably due to intense metamorphic dehydration and up to 2 wt% partial melting in the garnet stability field. The original magmatic sulfides at Kohistan appear to have been removed mainly by metamorphic fluids rather than by partial melts, as the arc-root samples could have experienced only very low degree of partial melting and the sulfur solubility in experimentally produced partial melts is low (≤0.1 wt%) even at oxygen fugacities two log-units above the fayalite-magnetite-quartz buffer. Furthermore, the experimental partial melts contain much less K2O, MgO, Cl and ±S than typical post-subduction porphyry Cu-forming magmas. Hence, we conclude that the role of sulfide-rich arc cumulates in the formation of post-subduction porphyry Cu magmas has been severely overestimated.
A series of Sn-doped TiO2 with Sn content ranging from 0.25 to 1 mol % were successfully synthesized by the hydrothermal method, and its performance as the photoanode of dye-sensitized solar cells ...(DSSCs) was investigated. TEM and XRD results indicate that the doping has no effect on the morphology and the crystal form of TiO2. The shift of XRD peaks observed at higher angle and the XPS results indicate Sn4+ ions incorporation into the TiO2 lattice. The flatband potential of Sn-TiO2 films shifts from −0.505 V (vs SCE) to −0.55 V with increasing Sn content from 0 to 1 mol at. %, which is beneficial to the increase of V oc. The higher transfer rate of electrons in the Sn-doped TiO2 films than in the undoped TiO2 films is confirmed by IMPS measurements, which is favorable to the higher J sc. IMVS and EIS measurements indicate that the charge recombination increases with increasing Sn doping content. Taking these factors, the optimum efficiency of 8.31% was found at 0.5 mol % Sn-doped TiO2 based DSSCs, which gave an efficiency improved by 12.1% compared with that of the cells based on pure TiO2 (7.45%). This work shows that Sn-doped TiO2 is a most interesting material and has good potential for application in photoenergy conversion devices.
The objective of this study was to investigate the risk of cardiovascular toxicities related to PD-1/PD-L1 inhibitors in solid tumors.
A literature search was performed following the participants, ...interventions, comparisons, outcomes, and study design (PICOS) principles, and the study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data analysis was conducted using Review Manager version 5.4.
This meta-analysis included 69 randomized controlled trials (RCTs) divided into five groups based on the treatment regimens: PD-1/PD-L1 + chemotherapy versus chemotherapy, PD-1/PD-L1 versus chemotherapy, PD-1/PD-L1 versus placebo, PD-1/PD-L1 + CTLA-4 versus PD-1/PD-L1 and PD-1/PD-L1 + CTLA-4 versus chemotherapy. Compared to chemotherapy treatment alone, PD-1/PD-L1 +chemotherapy significantly increased the risk of hypertension all-grade (OR = 1.27, 95% CI 1.05, 1.53, p = 0.01); grade 3-5 (OR = 1.36, 95% CI 1.04, 1.79, p = 0.03), hypotension all-grade (OR = 2.03, 95% CI 1.19, 3.45, p = 0.009); grade 3-5 (OR = 3.60, 95% CI 1.22, 10.60, p = 0.02), arrhythmia all-grade (OR = 1.53, 95% CI 1.02, 2.30, p = 0.04); grade 3-5 (OR = 2.91, 95% CI 1.33, 6.39, p = 0.008) and myocarditis all-grade (OR = 2.42, 95% CI 1.06, 5.54, p = 0.04). The risk of all-grade hypotension (OR = 2.87, 95% CI 1.26, 6.55, p = 0.01) and all-grade arrhythmia (OR = 2.03, 95% CI 1.13, 3.64, p = 0.02) significantly increased when treated with PD-1/PD-L1 inhibitors compared to the placebo. The risks of cardiovascular toxicities are significantly higher with PD-1+CTLA-4 compared to PD-1 alone (OR = 2.02, 95% CI 1.12, 3.66, p = 0.02).
PD-1/PD-L1 inhibitor leads to an increased risk of cardiovascular toxicities, especially hypertension, hypotension, arrhythmia, and myocarditis.
We examine the potential of the future medium-baseline reactor neutrino oscillation (MBRO) experiments in studying neutrino wave-packet impact. In our study, we treat neutrinos as wave packets and ...use the corresponding neutrino flavor transition probabilities. The delocalization, separation and spreading of the wave packets lead to decoherence and dispersion effects, which modify the plane-wave neutrino oscillation pattern, by amounts that depend on the energy uncertainties in the initial neutrino wave packets. We find that MBRO experiments could be sensitive to the wave-packet impact, since the baseline is long enough and also the capability of observing small corrections to the neutrino oscillations due to excellent detector energy resolution. Besides studying the constraints on the decoherence parameter, we also examine the potential wave-packet impacts on the precision of measuring θ12 and other oscillation parameters in the future medium-baseline reactor neutrino oscillation experiments. Moreover, we also probe the potential benefits of an additional detector for studying such exotic neutrino physics.
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