ABSTRACT
We present the integrated three-point shear correlation function iζ± – a higher order statistic of the cosmic shear field – which can be directly estimated in wide-area weak lensing surveys ...without measuring the full three-point shear correlation function, making this a practical and complementary tool to two-point statistics for weak lensing cosmology. We define it as the one-point aperture mass statistic Map measured at different locations on the shear field correlated with the corresponding local two-point shear correlation function ξ±. Building upon existing work on the integrated bispectrum of the weak lensing convergence field, we present a theoretical framework for computing the integrated three-point function in real space for any projected field within the flat-sky approximation and apply it to cosmic shear. Using analytical formulae for the non-linear matter power spectrum and bispectrum, we model iζ± and validate it on N-body simulations within the uncertainties expected from the sixth year cosmic shear data of the Dark Energy Survey. We also explore the Fisher information content of iζ± and perform a joint analysis with ξ± for two tomographic source redshift bins with realistic shape noise to analyse its power in constraining cosmological parameters. We find that the joint analysis of ξ± and iζ± has the potential to considerably improve parameter constraints from ξ± alone, and can be particularly useful in improving the figure of merit of the dynamical dark energy equation of state parameters from cosmic shear data.
Commercial Cu/SAPO-34 selective catalytic reduction (SCR) catalysts have experienced unexpected and quite perplexing failure. Understanding the causes at an atomic level is vital for the synthesis of ...more robust Cu/SAPO-34 catalysts. Here we show, via application of model catalysts with homogeneously dispersed isolated Cu ions, that Cu transformations resulting from low-temperature hydrothermal aging and ambient temperature storage can be semi-quantitatively probed with 2-dimensional pulsed electron paramagnetic resonance. Coupled with kinetics, additional material characterizations and DFT simulations, we propose the following catalyst deactivation steps: (1) detachment of Cu(II) ions from cationic positions in the form of Cu(OH)
; (2) irreversible hydrolysis of the SAPO-34 framework forming terminal Al species; and (3) interaction between Cu(OH)
and terminal Al species forming SCR inactive, Cu-aluminate like species. Especially significant is that these reactions are greatly facilitated by condensed water molecules under wet ambient conditions, causing low temperature failure of the commercial Cu/SAPO-34 catalysts.
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•Layered double hydroxides (LDHs), as MgFe and CoCr type, were synthesized.•LDHs with variable M2+:M3+ molar ratio and calcination condition were investigated.•I− was efficiently ...removed by MgFe-4C through reconstruction effect.•IO3− was efficiently removed by CoCr-4NC through ion exchange and redox reactions.
Radioactive iodine-129 (129I) is a contaminant of concern at radiological waste disposal and nuclear power production sites where it can incidentally be released into the environment and migrate to groundwater. Development of remediation options for 129I is hindered by its complex and mobile redox speciation. In this work, we systematically evaluated nanostructured layered double hydroxide (LDH) materials comprised of MgFe or CoCr with variable M2+:M3+ molar ratios for their affinity for the environmentally-relevant anions of iodine including iodide (I−) and iodate (IO3−). Uncalcined MgFe material demonstrated overall poor selectivity, however, affinity for I− significantly increased with increasing Mg:Fe molar ratio and upon calcination due to elimination of the parent anions followed by reconstruction of the original LDH structure, assuming physisorption. Specific surface area of calcined MgFe before and after I− sorption showed 44.3 and 13.2 m2 g−1, respectively, indicating significant decrease by reconstruction effect. In addition, high sorption capacity of calcined MgFe for I− at about 2.5 mmol g−1 suggests its applicability for immobilization of 129I. On the other hand, uncalcined CoCr material exhibited high selectivity, affinity, and capacity (about 2 mmol g−1) for IO3− indicating chemisorption and its utility for treatments of 129I in groundwater. There was a minor specific surface area variation of uncalcined CoCr before and after IO3− sorption by ion exchange (53.2 and 64.0 m2 g−1, respectively). Overall this study provides mechanistic insights into understanding and prediction of behavior of the LDH materials as efficient sorbent for design of remedial option for 129I.
Variation in the methodology of in vitro transporter inhibition assays causes wide divergence in reported IC
/K
data. Notably, although potentiation of transporter inhibition by preincubation (PTIP) ...has been described, current guidelines do not specifically recommend inhibitor preincubation; they only encourage sponsors to follow emerging literature. To clarify how generally preincubation should be considered in transporter inhibition studies and whether PTIP can be solely explained by protein binding of the respective inhibitors, we performed in vitro inhibition assays on solute carrier (SLC) and ATP-binding cassette transporters scarcely or not covered in prior research and examined the effect of extracellular protein in preincubation and washout experiments. In SLC assays without extracellular protein, a 30-minute preincubation caused significant > twofold change of IC
in 21/33 transporter-inhibitor combinations involving 19 evolutionarily disparate transporters. The preincubation effect correlated with inhibitor properties like protein binding and aqueous solubility. In vesicular transport assays of multidrug resistance protein 1, breast cancer resistance protein, multidrug resistance-associated protein 2, and bile salt export pump, sizable PTIP was observed for only 2/23 combinations, and preincubation was practically inconsequential in breast cancer resistance protein or multidrug resistance protein 1 monolayer assays. In SLC assays, PTIP partly persisted in the presence of 5% albumin, indicating that the absence of extracellular protein does not fully explain PTIP. The presence of protein, however, complicated the interpretation of results. Overall, while preincubating without protein may overpredict inhibitory potency, adding protein compromises clarity, and omitting preincubation altogether may miss clinically relevant inhibitors. Therefore, we propose that protein-free preincubation should be considered in all SLC inhibition assays. ATP-binding cassette transporter inhibition seems less commonly affected by preincubation, but conclusions require further investigation. SIGNIFICANCE STATEMENT: Drugs may inhibit transporter proteins in the body, which may precipitate drug interactions. In vitro transporter inhibition assays help predict such drug interactions. Some inhibitors act more potently when preincubated with the transporter prior to the assay. Here we argue that this effect is not a mere in vitro artifact due to the lack of plasma proteins and should be considered in all uptake inhibition assays to model the worst-case scenario. Preincubation in efflux transporter inhibition assays is likely dispensable.
Multifunctional living materials are attractive due to their powerful ability to self-repair and replicate. However, most natural materials lack electronic functionality. Here we show that an ...electric field, applied to electricity-producing Geobacter sulfurreducens biofilms, stimulates production of cytochrome OmcZ nanowires with 1,000-fold higher conductivity (30 S cm
) and threefold higher stiffness (1.5 GPa) than the cytochrome OmcS nanowires that are important in natural environments. Using chemical imaging-based multimodal nanospectroscopy, we correlate protein structure with function and observe pH-induced conformational switching to β-sheets in individual nanowires, which increases their stiffness and conductivity by 100-fold due to enhanced π-stacking of heme groups; this was further confirmed by computational modeling and bulk spectroscopic studies. These nanowires can transduce mechanical and chemical stimuli into electrical signals to perform sensing, synthesis and energy production. These findings of biologically produced, highly conductive protein nanowires may help to guide the development of seamless, bidirectional interfaces between biological and electronic systems.
Alternative methods, including green synthetic approaches for the preparation of various types of nanoparticles are important to maintain sustainable development. Extracellular or intracellular ...extracts of fungi are perfect candidates for the synthesis of metal nanoparticles due to the scalability and cost efficiency of fungal growth even on industrial scale. There are several methods and techniques that use fungi-originated fractions for synthesis of gold nanoparticles. However, there is less knowledge about the drawbacks and limitations of these techniques. Additionally, identification of components that play key roles in the synthesis is challenging. Here we show and compare the results of three different approaches for the synthesis of gold nanoparticles using either the extracellular fraction, the autolysate of the fungi or the intracellular fraction of 29 thermophilic fungi. We observed the formation of nanoparticles with different sizes (ranging between 6 nm and 40 nm) and size distributions (with standard deviations ranging between 30% and 70%) depending on the fungi strain and experimental conditions. We found by using ultracentrifugal filtration technique that the size of reducing agents is less than 3 kDa and the size of molecules that can efficiently stabilize nanoparticles is greater than 3 kDa.
•Application of eight runaway criteria are analyzed in trajectory optimization.•The criterion which meets real runaway for fed-batch reactor is stated.•Optimization of feeding trajectory using ...runaway criteria as non-linear constraint.
Process engineers and operators should understand reactor runaway phenomenon to avoid hazard situations and accidents. Reactor runaway occurs when an exothermic reaction takes place in a reactor with insufficient heat transfer area. The reaction rate increases due to the temperature rise, causing a further increase in reaction rate and temperature. Without any safety action, only the reactant consumption limits the maximum temperature. One of the safety actions can be the application of runaway criteria to characterize the safe operating regimes where the optimal operating conditions can be found. This paper presents runaway criteria and the application of these in case of the feeding trajectory optimization of a fed-batch reactor model. The most important runaway criteria and the relations between them are presented, and critical curves of criteria are calculated using a simple dimensionless tubular reactor. The optimal feeding trajectory is determined in case a pilot plant fed-batch reactor using different runaway criteria as a non-linear constraint based on particle swarm optimization and sequential quadratic programming. Designers need to know how they can choose the right criterion, and the results can help with it. Selectivity and profit can be decreased if runaway occurs in a fed-batch reactor, therefore it is important to deal with this problem.
Macrophage gene expression determines phagocyte responses and effector functions. Macrophage plasticity has been mainly addressed in in vitro models that do not account for the environmental ...complexity observed in vivo. In this study, we show that microarray gene expression profiling revealed a highly dynamic landscape of transcriptomic changes of Ly6C(pos)CX3CR1(lo) and Ly6C(neg)CX3CR1(hi) macrophage populations during skeletal muscle regeneration after a sterile damage. Systematic gene expression analysis revealed that the time elapsed, much more than Ly6C status, was correlated with the largest differential gene expression, indicating that the time course of inflammation was the predominant driving force of macrophage gene expression. Moreover, Ly6C(pos)/Ly6C(neg) subsets could not have been aligned to canonical M1/M2 profiles. Instead, a combination of analyses suggested the existence of four main features of muscle-derived macrophages specifying important steps of regeneration: 1) infiltrating Ly6C(pos) macrophages expressed acute-phase proteins and exhibited an inflammatory profile independent of IFN-γ, making them damage-associated macrophages; 2) metabolic changes of macrophages, characterized by a decreased glycolysis and an increased tricarboxylic acid cycle/oxidative pathway, preceded the switch to and sustained their anti-inflammatory profile; 3) Ly6C(neg) macrophages, originating from skewed Ly6C(pos) cells, actively proliferated; and 4) later on, restorative Ly6C(neg) macrophages were characterized by a novel profile, indicative of secretion of molecules involved in intercellular communications, notably matrix-related molecules. These results show the highly dynamic nature of the macrophage response at the molecular level after an acute tissue injury and subsequent repair, and associate a specific signature of macrophages to predictive specialized functions of macrophages at each step of tissue injury/repair.
ABSTRACT
Periodically variable quasars have been suggested as close binary supermassive black holes. We present a systematic search for periodic light curves in 625 spectroscopically confirmed ...quasars with a median redshift of 1.8 in a 4.6 deg2 overlapping region of the Dark Energy Survey Supernova (DES-SN) fields and the Sloan Digital Sky Survey Stripe 82 (SDSS-S82). Our sample has a unique 20-yr long multicolour (griz) light curve enabled by combining DES-SN Y6 observations with archival SDSS-S82 data. The deep imaging allows us to search for periodic light curves in less luminous quasars (down to r ∼23.5 mag) powered by less massive black holes (with masses ≳ 108.5M⊙) at high redshift for the first time. We find five candidates with significant (at >99.74 per cent single-frequency significance in at least two bands with a global p-value of ∼7 × 10−4–3 × 10−3 accounting for the look-elsewhere effect) periodicity with observed periods of ∼3–5 yr (i.e. 1–2 yr in rest frame) having ∼4–6 cycles spanned by the observations. If all five candidates are periodically variable quasars, this translates into a detection rate of ${\sim }0.8^{+0.5}_{-0.3}$ per cent or ${\sim }1.1^{+0.7}_{-0.5}$ quasar per deg2. Our detection rate is 4–80 times larger than those found by previous searches using shallower surveys over larger areas. This discrepancy is likely caused by differences in the quasar populations probed and the survey data qualities. We discuss implications on the future direct detection of low-frequency gravitational waves. Continued photometric monitoring will further assess the robustness and characteristics of these candidate periodic quasars to determine their physical origins.
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