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ErO crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Er is bonded to five equivalent O atoms to form a mixture of edge and corner-sharing ErO5 trigonal bipyramids. There are three shorter (2.29 Å) and two longer (2.38 Å) Er–O bond lengths. O is bonded to five equivalent Er atoms to form a mixture of edge and corner-sharing OEr5 trigonal bipyramids.
We evaluated the ecological effectiveness of an in-stream restoration project involving coarse woody debris (CWD) additions to streams along an upland soil and vegetation disturbance gradient at the Fort Benning Military Installation near Columbus, GA. We examined short-term (immediate effectiveness) and longer-term (sustainability) responses to CWD additions by measuring ecosystem metabolism rates in 8 streams quarterly over a 6-year period, including 3 years before (2001–2003) and 3 years after (2004–2006) CWD additions that were made to half of the streams. Ecosystem respiration (ER) rates in most CWD addition streams increased relative to control streams from spring 2004 through autumn 2005, suggesting heterotrophic bacteria were the initial responders to CWD additions. Gross primary production (GPP) rates remained low (typically < 0.3 g O 2 m -2 d -1 ) but increased in some CWD addition streams relative to control streams in spring 2004 and 2005. The magnitude of ER increases in CWD addition streams during the first two years post-addition increased with catchment disturbance intensity, indicating that more heavily disturbed streams responded most strongly to restorations—an important consideration when targeting future restoration locations. Because restorations did not address actual upland disturbance, continued high erosion rates resulted in 32–77% of the added CWD being buried by year two and a corresponding return of GPP and ER rates to pre-CWD addition levels by year three. If restoration projects do not adequately address the source of catchment disturbances, CWD additions will provide only short-term increases in streambed structure and stability, hydrodynamic complexity, and nutrient and organic matter processing and retention.
For presentation at Materials Science Technology 2023, Columbus, OH, October 1-4, 2023.
Eddy covariance measurements of land-atmosphere energy, carbon, and water exchange now span multiple decades at some sites, supporting an improved understanding of flux interannual variability (IAV) and its ecophysiological and physical controls. Most eddy covariance IAV studies have focused on temperate forest ecosystems, where carbon fluxes are large and flux records are longest – but also where IAV is much lower than in dryland regions, which have been identified as an essential driver of the trend and variability in the global terrestrial carbon sink. In this study, we leveraged 19 years of continuous micrometeorological measurements at the AmeriFlux US-SRM mesquite savanna site in southern Arizona, USA to quantify the IAV, trends, and drivers of carbon fluxes during the distinct spring and summer growing seasons. We also assessed the ability of modern satellite and land surface models to capture the IAV of seasonal water and carbon fluxes. Annual net ecosystem production (NEP) was small and highly variable (23 +/- 64 gC m –2 yr –1 ). Precipitation and associated measures of water availability determined most of the variability in NEP, largely through their influence on annual and seasonal gross ecosystem productivity (GEP) as opposed to ecosystem respiration (ER). Root-zone soil moisture captured between 73% (spring) and 85% (summer) of GEP variability and between 73% (spring) and 58% (summer) of ER variability. Throughout the study period, soil moisture and greenness increased with associated increases in GEP, ER and NEP. These trends were strongly influenced by very productive and wet summer growing seasons during the last two years, which were characterized by abundant understory grass cover. Typically, less than half of the variability in growing season GEP and evapotranspiration was captured by satellite-based estimates and land surface model simulations with local site forcing and calibration, highlighting the ongoing utility of long-term datasets to support careful model testing and improvement.
Multicomponent zirconate solid solutions A 2 Zr 2 O 7 (A= (Sm,Yb), (Sm,Yb,Gd), (Sm,Yb,Gd,Er), and (Sm,Yb,Gd,Er,Dy)) were synthesized through spark plasma sintering and their chemical durability was investigated via semi-dynamic leaching tests in pH = 1 nitric acid at 90°C. Incongruent dissolution occurred for all samples with the preferential elemental release of zirconium in all A 2 Zr 2 O 7 except for high entropy (Sm,Yb,Gd,Er,Dy)Zr 2 O 7 which displays a congruent release of the A-site elements and Zr. A strong positive correlation was found between the lanthanide elemental release rates and the A-site cation size disorder, whereas a negative correlation was observed between the elemental release rates and mixing entropy.
The imbalance between osteogenesis and adipogenesis in the bone marrow is the main characteristic of osteoporosis (OP). Thus, exploring regulation of the differentiation of bone marrow stromal cells (BMSCs) into osteoblasts and adipocytes is important to identify novel targets for the treatment of OP. In the present study, the master regulator of endoplasmic reticulum (ER) stress, heat shock protein family A (Hsp70) member 5 (HSPA5) was shown to significantly accumulate in osteoblasts and adipocytes, but not in osteoclasts in bone sections from aged and postmenopausal OP mice. In vitro study revealed that HSPA5 negatively modulated osteogenic differentiation and positively promoted adipogenic differentiation, and that targeting HSPA5 with its inhibitor HA15 enhanced osteogenic differentiation and inhibited adipogenic differentiation. Also, HA15 treatment induces ER stress and autophagy, and decreases apoptosis in cells. We constructed a postmenopausal OP model in mice with ovariectomy surgery, and treated the mice with HA15. The results showed that HA15 treatment induced appropriate ER stress, activated autophagy and decreased apoptosis in osteoblasts, thereby alleviating bone loss in vivo. Our results indicated that HSPA5 participated in OP pathogenesis by regulating the differentiation of BMSCs. HSPA5 may serve as a new target for the treatment of OP, and targeting HSPA5 with HA15 prevents the progression of OP and provides a candidate therapeutic molecule for postmenopausal OP.
The impact of including model-averaged excess radiation risks (ER) into a measure of radiation attributed decrease of survival (RADS) for the outcome all solid cancer incidence and the impact on the uncertainties is demonstrated. It is shown that RADS applying weighted model averaged ER based on AIC weights result in smaller risk estimates with narrower 95% CI than RADS using ER based on BIC weights. Further a multi-method-multi-model inference approach is introduced that allows calculating one general RADS estimate providing a weighted average risk estimate for a lunar and a Mars mission. For males the general RADS estimate is found to be 0.42% (95% CI: 0.38%; 0.45%) and for females 0.67% (95% CI: 0.59%; 0.75%) for a lunar mission and 2.45% (95% CI: 2.23%; 2.67%) for males and 3.91% (95% CI: 3.44%; 4.39%) for females for a Mars mission considering an age at exposure of 40 years and an attained age of 65 years. It is recommended to include these types of uncertainties and to include model-averaged excess risks in astronaut risk assessment.
Compositionally complex oxides have garnered attention recently for their potential technological applications in harsh environments such as thermal barrier coatings and nuclear waste forms. Therefore, their response to extreme conditions, including high temperature and intense irradiation fields, must be thoroughly investigated. Here, the structural evolution of two pyrochlore oxides with comparable cation size ratio, r A /r B , (Yb 0.2 Er 0.2 Dy 0.2 Tb 0.2 Gd 0.2 ) 2 Ti 2 O 7 and Ho 2 Ti 2 O 7 , was evaluated after irradiation with 946 MeV Au ions up to a fluence of 8 × 10 12 ions/cm2 using synchrotron X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The overall radiation response is comparable for both titanate oxides and is dominated by a loss of crystallinity. When compared to a series of conventional titanate pyrochlore compositions, the amorphous track diameter of (Yb 0.2 Er 0.2 Dy 0.2 Tb 0.2 Gd 0.2 ) 2 Ti 2 O 7 is slightly larger than that of Ho2Ti2O7 and more in line with the diameter of the endmember with the maximum A-site cation size (Gd 2 Ti 2 O 7 ). Density functional theory calculations suggest that this behavior may be linked to local lattice distortions and the associated energetics of cation antisite formation. TEM and Raman analyses show that a disordered, crystalline shell surrounds the amorphous ion tracks in (Yb 0.2 Er 0.2 Dy 0.2 Tb 0.2 Gd 0.2 ) 2 Ti 2 O 7 , and the corresponding short-range structure resembles a weberite-type atomic arrangement.
Here the low-valent rhenium(I) salt Na[Re(η 5 -Cp)(BDI)] (BDI = N,N'-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate) was shown to react with various halide and chalcogenolate reagents, leading to the isolation of a series of rhenium(III)-halide and -pseudohalide complexes: Re(X)(η 5 -Cp)(BDI) (1-X, X = F, Cl, Br, I; 2, X = OTf) and Re(ER)(η 5 -Cp)(BDI) (3-ER, ER = SBn, SeBn, TePh). The 1 H NMR spectra of these complexes displayed sharp resonances shifted several ppm from typical diamagnetic regions, as well as distinct chemical shift trends down both the halide (with the exception of F) and chalcogenolate series, with both Cp and BDI backbone peaks moving downfield with increasing atomic number. Subsequent magnetic susceptibility measurements of the rhenium(III) halides 1-Cl, 1-Br, and 1-I indicated that these complexes display temperature-independent paramagnetism (TIP), with χ TIP values of 7.41(44) × 10 -4 to 1.50(51) × 10 -3 cm 3 mol -1 . Multireference complete active space self-consistent field (CASSCF) computations incorporating spin-orbit state mixing revealed small energy separations (1.7-3.0 kcal/mol) between thermally isolated ground states and the first excited spin-orbit states for the rhenium halides, confirming that low-lying excited states are responsible for the observed TIP behavior.
Abstract Predicting magnetic ordering in kagome compounds offers the possibility of harnessing topological or flat-band physical properties through tuning of the magnetism. Here, we examine the magnetic interactions and phases of ErMn 6 Sn 6 which belongs to a family of R Mn 6 Sn 6 , R = Sc, Y, Gd–Lu, compounds with magnetic kagome Mn layers, triangular R layers, and signatures of topological properties. Using results from single-crystal neutron diffraction and mean-field analysis, we find that ErMn 6 Sn 6 sits close to the critical boundary separating the spiral-magnetic and ferrimagnetic ordered states typical for non-magnetic versus magnetic R layers, respectively. Finding interlayer magnetic interactions and easy-plane Mn magnetic anisotropy consistent with other members of the family, we predict the existence of a number of temperature and field dependent collinear, noncollinear, and noncoplanar magnetic phases. We show that thermal fluctuations of the Er magnetic moment, which act to weaken the Mn-Er interlayer magnetic interaction and quench the Er magnetic anisotropy, dictate magnetic phase stability. Our results provide a starting point and outline a multitude of possibilities for studying the behavior of Dirac fermions in R Mn 6 Sn 6 compounds with control of the Mn spin orientation and real-space spin chirality.
A new naphthylsalophen and its 3:2 ligand-to-lanthanide sandwich-type complexes were isolated. Here, when excited at 380 nm, the complexes display the characteristic metal-centred emission for Nd III , Er III and Yb III . Upon 980 nm excitation, in mixed lanthanide and the Er complexes, Er-centred upconversion emission at 543 and 656 nm is observed, with power densities as low as 2.18 W cm –2 .
Conjugated oligomers and polymers consisting of aromatic heterocycles are examples of next-generation organic electronic materials. However, control and optimization of the self-assembly of these materials in the solid-state, which is a crucial parameter for high efficiency performance, remains an unsolved challenge in materials development. In this work, we provide valuable insight into aromatic stacking interactions between fluorinated arene rings (ArF) and heterocycles with different electronic character (Het), and elaborate on the prospect of using these interactions to control the solid-state configurations of three-ring phenyleneethynylene oligomers (PEs). Oligomers possessing heterocycles typically thought of as electron-rich (ER) show blue-shifted optical spectra in the solid-state, while those incorporating heterocycles typically thought of us electron deficient (ED) show red-shifted solid-state optical spectra. Crystal structures show ArF-Het stacking interactions between the fluorinated side-chains and ER units, which twist the backbone out of planarity and prevent chromophore aggregation. Further, the interactions are absent in ED oligomers, highlighting cofacial incompatibility between ArF rings and ED units. A combination of TD-DFT computations and novel heterocycle descriptors reinforce our assignment of the oligomers as ED or ER, while exhaustive conformer analysis shows ArF-Het stacking interactions are a significant contributor to compound stability. Overall, this work describes the importance of heterocycle electronics in conformational control in the solid state, understanding of which can be a valuable asset in the development of novel optoelectronic materials.
Advancing thermal/environmental barrier coating (TEBC) materials with integrated thermal-mechanical functions is paramount for safeguarding SiC-based ceramic matrix composites (CMCs) in high-efficiency gas turbines. Herein, we employ a synergistic approach, combining density functional theory (DFT) methods and combinatorial chemistry techniques, to design high-performance and low-cost RE 2 Si 2 O 7 (RE = rare earth elements) TEBC materials tailored for enhanced compatibility with SiC-based CMCs. Expanding on phase stability of alloying pure RE 2 Si 2 O 7 , the investigation extends to the mechanical and thermal properties of solid solution systems, including Er 1/2 Y 3/4 Yb 3/4 Si 2 O 7 , Gd 1/4 Er 1/4 Y 3/4 Yb 3/4 Si 2 O 7 , and Eu 1/4 Er 1/4 Y 3/4 Yb 3/4 Si 2 O 7 . The solid solution systems exhibit a major reduction in lattice thermal conductivity relative to their pure counterparts, achieving ultralow values of 0.25 to 0.39 W m −1 K −1 at 1500 K. Furthermore, the coefficients of thermal expansion (CTE) of these solid solutions are precisely tuned within the desired range for SiC (4.4 to 5.5 × 10 −6 K −1 ), while maintaining good mechanical properties. Here, in particular, the addition of Eu 2 Si 2 O 7 demonstrates to be an important variable to the tuning of CTE and lattice thermal conductivity by leveraging its strong anharmonicity, presenting a pioneering avenue for fine-tuning material properties. In summary, this research not only identifies promising TEBC materials with superior thermal properties, but also introduces a valuable computational material design methodology for the rapid discovery of complex materials for harsh environments.
Summary This study was designed to evaluate the relation between dysplastic squamous epithelium in the esophageal mucosa and the development of metachronous secondary primary malignancies (mSPM) other than esophagus after endoscopic resection (ER) in patients with early esophageal squamous cell carcinoma (SCC). We studied 330 patients with early esophageal SCC who underwent ER as a post hoc analysis of a prospective multicenter cohort study (UMIN Clinical Trials Registry ID UMIN000001676). Lugol-voiding lesions (LVL) were graded into 3 categories (A = no lesion; B = 1 to 9 lesions; C ≥ 10 lesions). The following variables were studied: (i) the incidences of mSPM other than esophagus; (ii) the standardized incidence ratios (SIRs) of mSPM; (iii) the cumulative incidence and total number of mSPM other than esophagus; and (iv) predictors of mSPM other than esophagus on analysis with a multivariate Cox proportional-hazards model. After a median follow-up of 46.6 months, mSPM other than esophagus was diagnosed in a total of 73 patients (90 lesions). Among the 106 patients in group C, 37 patients had mSPM (51 lesions), including head and neck cancer in 14 patients (24 lesions) and gastric cancer in 12 patients (16 lesions). The SIR of mSPM was 3.61 in this study subjects. An increase in the LVL grade (A to B to C) was associated with a progressive increase in the cumulative incidence rate of mSPM other than esophagus (P = 0.017 for A vs. C, P = 0.023 for B vs. C). An increase in the LVL grade (A to B to C) was also associated with a progressive increase in the total number of mSPM other than esophagus per 100 person-years (primary events, relative risk [RR] = 1.66 and 3.24 for grades B and C, respectively, vs. A, P = 0.002 for trend; all events, RR = 1.81 and 4.66 for grades B and C, respectively, vs. A, P < 0.0001 for trend). LVL grade C was a strong predictor of mSPM other than esophagus (RR = 3.41 for A vs. C). LVL grade may be a useful predictor of the risk of mSPM other than esophagus after ER in patients with early esophageal SCC.
Mitochondrial division is a fundamental biological process essensial for cellular functionality and vitality. The prevailing hypothesis that dynamin related protein 1 (Drp1) provides principal control in mitochondrial division, in which it also involves the endoplasmic reticulum (ER) and the cytoskeleton, does not account for all the observations. Therefore. the hypothesis may be incomplete. Our previous study in HeLa cells led to a new hypothesis of mitochondrial division by budding. To follow-up our previous study, we employed in situ cryo-electron tomography to visualize mitochondrial budding in the intact healthy monkey kidney cells (BS-C-1 cells). Our findings reaffirm single and multiple mitochondrial budding, consistent with our observations in HeLa cells. Notably, the budding regions vary significantly in diameter and length, which may represent different stages of budding. More interestingly, neither rings nor ring-like structures, nor the wrapping of ER tubes was observed in the budding regions, suggesting mitochondrial budding is independent from Drp1 and ER. Meanwhile, we uncovered direct interactions between mitochondria and large vesicles that are distinct from small mitochondrial-derived vesicles and extracellular mitovesicles. In conclusion, we propose that these interacting vesicles may have mitochondrial origins.
ABSTRACT Based on the integral field unit (IFU) data from Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, we develop a new method to select galaxies with biconical ionized structures, building a sample of 142 edge-on biconical ionized galaxies. We classify these 142 galaxies into 81 star-forming galaxies, 31 composite galaxies, and 30 AGNs (consisting of 23 Seyferts and 7 LI(N)ERs) according to the [N ii]-BPT diagram. The star-forming bicones have bar-like structures while AGN bicones display hourglass structures, and composite bicones exhibit transitional morphologies between them due to both black hole and star formation activities. Star-forming bicones have intense star formation activities in their central regions, and the primary driver of biconical structures is the central star formation rate surface density. The lack of difference in the strength of central black hole activities (traced by dust attenuation corrected [O iii]λ5007 luminosity and Eddington ratio) between Seyfert bicones and their control samples can be naturally explained as that the accretion disc and the galactic disc are not necessarily coplanar. Additionally, the biconical galaxies with central LI(N)ER-like line ratios are edge-on disc galaxies that show strong central dust attenuation. The radial gradients of H α surface brightness follow the r−2.35 relation, roughly consistent with r−2 profile, which is expected in the case of photoionization by a central point-like source. These observations indicate obscured AGNs or AGN echoes as the primary drivers of biconical structures in LI(N)ERs.
Geometrically frustrated magnetic systems, such as those based on the Shastry-Sutherland lattice (SSL), offer a rich playground for exploring unconventional magnetic states. The delicate balance between competing interactions in these systems leads to the emergence of novel phases. We present the characterization of Er 2 Be 2 GeO 7 , an SSL compound with Er 3+ ions forming orthogonal dimers separated by nonmagnetic layers whose structure is invariant under the 𝑃$\bar{4}21$𝑚 space group. Neutron scattering reveals an antiferromagnetic dimer structure at zero field, typical of Ising spins on that lattice and consistent with the anisotropic magnetization observed. However, magnetization measurements exhibit fractional plateaus at 1/4 and 1/2 of saturation, in contrast to the expected 1/3 plateau of the SSL Ising model. By comparing the energy of candidate states with ground-state lower bounds we show that this behavior requires spatially anisotropic interactions, leading to an anisotropic Shastry-Sutherland Ising model symmetric under the 𝐶𝑚𝑚2 space group. This anisotropy is consistent with the small orthorhombic distortion observed with single-crystal neutron diffraction. The other properties, including thermodynamics, which have been investigated theoretically using tensor networks, point to small residual interactions, potentially due to further couplings and quantum fluctuations. This study highlights Er 2 Be 2 GeO 7 as a promising platform for investigating exotic magnetic phenomena.
High-resolution synchrotron X-ray diffraction data confirm the stabilization of the average structure at ambient temperatures as a defect fluorite structure in ternary and quaternary oxides of Bi 2 O 3 , where some Bi cations are replaced with Dy 3+ and/or Er 3+ , Nb 5+ and W 6+ . Rietveld refinement of the diffraction data indicates that when the larger cation Er 3+ (0.89 Å) is replaced with smaller cations W 6+ (0.42 Å) and/or Nb 5+ (0.48 Å), the unit-cell parameter a, based on the relative ionic radii of the substituents, counterintuitively increases. Total scattering data show that the identity of the cation substituent is important in determining the positions of some Bi cations in the defect fluorite structure. Er 3+ and Dy 3+ cations induce monoclinic-like distortions that extend only locally in the Bi 3+ sublattice. X-ray absorption spectroscopy provides evidence that some Dy cations, in the δ phases, prefer to keep a similar local environment to that in the parent Dy 2 O 3 . W cations are found to be predominantly tetrahedrally coordinated in the δ phases explored in this work.