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Assessment of head-cervical spine motion (HCSM) is a vital index of functional evaluation for cervical surgery, but there is a lack of HCSM datasets in the healthy population and no suitable tools to measure HCSM in clinical practice. The objectives of this study were to obtain the normal values of HCSM in a healthy population, test the reliability and validity of an APP "G-Plus," and analyze related influencing factors of HCSM. We measured HCSM in 6 directions of 500 healthy people with a CROM apparatus and "G-Plus." The intraclass correlation coefficient (ICC) was used to test the reliability of "G-Plus." The validity of "G-Plus" measurements as compared with the CROM apparatus was tested by Bland-Altman statistics. We used multiple linear regression analysis to test the correlation among age, gender, body mass index (BMI), neck configuration (ratio of cervical circumference to cervical length), and HCSM. Excellent interrater and intrarater reliability were demonstrated for CROM (ICC:0.929-0.993) and "G-Plus" (ICC: 0.898-0.991). Bland-Altman plots demonstrated an acceptable agreement between CROM and "G-Plus." Age was negatively correlated with HCSM. HCSM in females was superior to males except for flexion. Neck configuration affected HCSM in the direction of extension, right lateral flexion, and left and right rotation. BMI was correlated with flexion and extension. "G-Plus" is a reliable and convenient tool for HCSM measurement in clinical practice. The presentation of datasets of HCSM in healthy population provides a basic reference for cervical function assessment. Age, gender, BMI, and neck configuration are significantly correlated to HCSM. [ABSTRACT FROM AUTHOR]

Background: Leadless pacemakers (LPs) have proven safe and effective, but device revisions remain necessary. Either replacing the LP or implanting a new adjacent LP is feasible. Replacement seems more appealing, but encapsulation and tissue adhesions may hamper the safety and efficacy of LP retrieval.Objective: We determined the incidence and cellular characteristics of tissue adherent to retrieved LPs and the potential implications for end-of-life strategy.Methods: All 15 consecutive successful Nanostim LP retrievals in a tertiary center were included. We assessed the histopathology of adherent tissue and obtained clinical characteristics.Results: Adherent tissue was present in 14 of 15 retrievals (93%; median implantation duration 36 months; range 0-96 months). The tissue consisted of fibrosis (n = 2), fibrosis and thrombus (n = 9), or thrombus only (n = 3). In short-term retrievals (<1 year), mostly fresh thrombi without fibrosis were seen. In later retrievals, the tissue consisted of fibrosis often with organizing or lytic thrombi. Fibrosis showed different stages of organization, notably early fibrocellular and later fibrosclerotic tissue. Inflammatory cells were seen (n = 4) without signs of infection. Tricuspid valve material was retrieved in 1 patient after 36 months, resulting in increased tricuspid regurgitation.Conclusion: Our results suggest that fibrosis and thrombus adherent to LPs are common and encapsulate the LP as seen in transvenous pacemakers. LPs may adhere to the tricuspid valve or subvalvular apparatus affecting retrieval safety. The end-of-life strategy should be optimized by incorporating risk stratification for excessive fibrotic encapsulation and adhesions. [ABSTRACT FROM AUTHOR]

Subduction related metasomatism has been proposed to be one of the most important processes that may cause Ca isotopic heterogeneities in the mantle. Back-arc basin basalts (BABBs) affected by different contributions of subducted materials have various geochemical compositions ranging from MORB-like to arc-like, so that they are ideal media to investigate the behavior of Ca isotopes during plate subduction. Here we report Ca isotopic compositions of a series of BABBs from the Lau Basin, Woodlark Basin and Coriolis Troughs in the southwestern Pacific. Our results show that δ44/40Ca of all the BABBs exhibit a narrow range of 0.73 ± 0.07 to 0.89 ± 0.06‰ with an average of 0.80 ± 0.08‰ (2SD, N = 21), which are lower than the estimated value of the Bulk Silicate Earth (BSE, 0.94 ± 0.05‰), but are similar to that of MORBs reported in the literature (0.83 ± 0.11‰, 2SD, N = 21). Even though the mantle sources of BABBs studied here have been influenced by various amounts of slab-derived fluids and/or sediments, there is no systematic variation of δ44/40Ca with indicators of subduction contributions (e.g., Ce/Pb, Nb/U, Ba/La, Th/Yb, 87Sr/86Sr and 143Nd/144Nd). This suggests that either there is no Ca isotopic discrepancy between subducted components and mantle, and/or the amount of Ca that is transferred from the subducting Pacific slab to the studied BABB mantle sources is insignificant. Water depths at which subducting sediments were deposited control the components of marine sediments that may be subducted, which in turn determine how subduction affects Ca isotopic composition of the mantle. Because the southwestern Pacific has deeper water depths than the carbonate compensation depth, pelagic clays dominate the contribution from the subducted slab rather than carbonates, which leads to the negligible Ca isotopic fractionation during subduction along these trenches. The lack of correlations of δ44/40Ca with geochemical indicators of magma differentiation (e.g., MgO, CaO/Al 2 O 3 , Sr/Nd, Eu/Eu*) suggests that intermediate-mafic magma differentiation has insignificant effects on Ca isotopic compositions of BABBs. Therefore, we conclude that the observed offset of δ44/40Ca (∼0.14‰) between the mantle and BABBs studied here should be primarily controlled by Ca isotopic fractionation during partial melting without significant contributions from subducted materials. [ABSTRACT FROM AUTHOR]

Detailed geochronological, geochemical, and Sr–Nd isotopic data are presented for late Paleozoic volcanic rocks in the Dashitou area from the Eastern Tianshan, NW China, aiming to constrain their petrogenesis and tectonic implications. The Dashitou volcanic rocks show a bimodal distribution in composition, with dominant rhyolite and subordinate basalt. LA–ICPMS zircon U–Pb age indicates that the volcanic rocks were erupted at 330 ± 3 Ma. The basaltic rocks are medium-K calc-alkaline, enriched in light rare earth element (LREE) and large ion lithophile element (LILE; Ba and U), and depleted in high field strength element (HFSE; Nb, Ta, and Ti). These features, together with their depleted isotopic signature (initial 87 Sr/ 86 Sr = 0.7035 to 0.7039, ε Nd ( t ) = 6.8 to 7.1), suggest that they were likely derived from a depleted mantle source metasomatized by subduction-related fluids. The rhyolitic rocks are high-K calc-alkaline and exhibit characteristics of A 2 -type granite, with typical enrichment in alkalis, Zr, and Nb and depletion in Sr, P, and Ti. They are characterized by positive ε Nd ( t ) values (6.2–6.5) with young Nd model ages (0.57–0.58 Ga). Results of MELTS modeling imply that they were unlikely produced by fractional crystallization of coeval basaltic rocks. Instead, they were probably generated by partial melting of juvenile basaltic crust as a result of magma underplating. The geochemical and Sr–Nd isotopic characteristics, coupled with regional geology, indicate that the formation of the Dashitou bimodal volcanic rocks involves an extensional regime associated with a subduction-related environment. The rifting of the Dananhu–Harlik arc in response to the retreat of the subducting Northern Tianshan oceanic lithosphere may account for the Dashitou bimodal volcanic rocks. [ABSTRACT FROM AUTHOR]

To clarify feasibility of using combinations of imazapic and prometryn to control weeds in peanut field, their interaction effect was evaluated in greenhouse and verified in field. The results of pot experiments showed that the interaction of imazapic at 32 g a.i. ha−1 and prometryn at 400–850 g a.i. ha−1 exhibited synergistic effects for the control of Chenopodium album L., Portulaca oleracea L. and Digitaria sanguinalis (L.) Scop., and that the observed response (E 0) was significantly greater than that expected (E). The combination of imazapic at 52 g a.i. ha−1 and prometryn at 400–850 g a.i. ha−1 also had synergistic effects on the control of Echinochloa crus-galli (L.) Beauv., and the E 0 value was significantly greater than the E value. Field experiment demonstrated that imazapic plus prometryn at 32 + 850 g a.i. ha-1 or 52 + 400 g a.i. ha-1 exhibited better weed density suppression (93.2% or 95.1%), which was significantly higher than imazapic (85.0%) and prometryn (71.8%) applied at 90 g a.i. ha−1 and 950 g a.i. ha−1, respectively. The combinations showed superior weed fresh weight control than when they were applied alone. Comparing with s -metolachlor, the mixtures also provided significantly higher control of weed density and fresh weight under field condition. The mixtures were safe for peanut. These findings indicate that PRE application of combinations of imazapic and prometryn has great potential for weed control in peanut fields in China and that recommended field doses of imazapic plus prometryn are 32 + 850 or 52 + 400 g a.i. ha−1. • Imazapic PRE application efficiently controls Poaceae weeds. • The interaction between imazapic and prometryn is synergistic. • The mixture of imazapic and prometryn effectively controls broadleaf weeds. • Recommended doses: imazapic plus prometryn 32 + 850 or 52 + 400 g a.i. ha−1. [ABSTRACT FROM AUTHOR]

Enrichments in light REE without concomitant enrichments in high-field-strength elements in mantle peridotites are usually attributed to inputs from carbonate-rich melts and referred to as 'carbonatite' metasomatism as opposed to interaction with evolved silicate melts. Alternatively, both enrichment types are ascribed to percolating volatile-bearing mafic liquids whose chemical signatures evolve from 'silicate' to 'carbonatite'. Here we compare these models for peridotites in which these enrichment types are combined, as may be common in the mantle. We report new Ca-Sr-Nd isotope and chemical data for lherzolite and harzburgite xenoliths from Spitsbergen that were metasomatized, first, by silicate, then by carbonate-rich melts that formed carbonate-bearing pockets replacing earlier minerals. Seven crushed samples were treated with acetic acid that dissolved carbonates formed in the latest event, but not silicates. The leachates (acid-removed carbonates making up 0.6–1.4% of total sample mass) contain much more Sr than the residues after leaching (277–2923 vs. 16–60 ppm), have a greater overall 87Sr/86Sr range (0.7049–0.7141 vs. 0.7036–0.7055) and higher 87Sr/86Sr in each sample than the residues. The leachates have lower δ44/40Ca range (0.17–0.68‰) than the residues (0.78–1.00‰), as well as lower δ44/40Ca than the residues in all samples but one. By and large, the carbonates are out of Ca-Sr isotope equilibrium with the host peridotites implying that the older silicate and younger carbonatite metasomatism were produced by different parental melts, thus supporting the existence of distinctive carbonate-rich metasomatic media in the lithospheric mantle, possibly including recycled materials. The δ44/40Ca in the leachates (i.e. carbonates, 0.17–0.68‰) are well below bulk silicate Earth (BSE) estimates (0.94 ± 0.05‰) and δ44/40Ca in non-metasomatized melt-depleted mantle. Yet, δ44/40Ca in the non-leached whole rock (WR) carbonate-bearing samples (0.75–0.95‰) fall within, or are only slightly lower than, the BSE range. The 87Sr/86Sr range in these WR samples (0.7030–0.7112) includes very high values for peridotites with large aggregates of dolomite and Mg-calcite. It appears that both carbonatite and silicate metasomatism may produce δ44/40Ca values lower than the BSE such that Ca-isotope data cannot robustly tell apart these two enrichment types, yet carbonatite metasomatism may yield the lowest δ44/40Ca. Carbonates, even at small mass fractions, are significant hosts of Sr in the WR Spitsbergen peridotites (8–51 wt.% of Sr mass) because of very high Sr concentrations, but add little to WR Ca balance (3–12 wt.%). As a result, high Sr content and 87Sr/86Sr ratios may be indices (though not definitive proofs) of carbonatite metasomatism in mantle rocks. [ABSTRACT FROM AUTHOR]

To better constrain Ca isotopic fractionation during volcanic magma differentiation, we report Ca isotope data for a series of volcanic glasses from the eastern Manus Basin that represent a continuum of compositions comprising basaltic andesite, andesite, dacite, and rhyolite. Our results show that these volcanic glasses exhibit ~0.25‰ variation in Ca isotopic compositions, with δ44/40Ca ranging from 0.81 ± 0.04 to 1.05 ± 0.04‰. The similar trace element patterns and Sr-Nd isotopic compositions exclude source heterogeneity as the cause of the varied Ca isotopic compositions. Due to their low K/Ca ratios and young age, the Ca isotopic variations cannot be attributed to 40K decay. Instead, the observed Ca isotopic variations are primarily controlled by their lithology. Specifically, δ44/40Ca of basaltic andesite (0.81 ± 0.04) and andesite (0.82 ± 0.01) are similar to the averages of reported mid-ocean ridge basalts (MORBs; 0.84 ± 0.10; 2SD, N = 26) and back-arc basin basalts (BABBs; 0.80 ± 0.08; 2SD, N = 21) in literature, but do not correlate with SiO 2 or MgO contents, indicating the Ca isotopic fractionation is insignificant during intermediate-mafic magma evolution. As magma differentiation continues, δ44/40Ca of dacite and rhyolite evolves from 0.85 ± 0.01 to 1.05 ± 0.04‰. Moreover, δ44/40Ca of felsic glasses are negatively correlated with Eu/Eu*, which suggests that the increasing δ44/40Ca of felsic glasses is most likely related to plagioclase (Pl) fractional crystallization. Therefore, we conclude that Ca isotopes can behave differently at different stages of volcanic magma differentiation. Modeling of fractional crystallization using rhyolite-MELTS shows that the relative Ca fractions in crystallized minerals (e.g., Pl vs. Cpx) and the Ca isotopic fractionation factor between the residual melt and crystallized Pl (α melt-Pl , which is likely related to the An number of Pl, magma temperature and kinetic effects during crystallization), provide a plausible explanation for the behavior of Ca isotopes during volcanic magma differentiation. [ABSTRACT FROM AUTHOR]

Calcium isotopes can potentially be used to trace many geological processes. Characterizing the Ca isotopic compositions of marine sediments is a precondition for using Ca isotopes to trace the recycling of marine sediments into the mantle and mantle-derived rocks. The best way to achieve this goal is to investigate different types of marine sediments that are adjacent to subduction zones and would undergo subduction in the future. Here, we present high-precision Ca isotopic data for marine sediments from the Deep Sea Drilling Project (DSDP) Sites 543 and 144 along the Lesser Antilles forearc region, to constrain the Ca isotope signatures of marine sediments with various components and assess their possible effects on δ44/40Ca of the local mantle and arc lavas via subduction. Our results show that the δ44/40Ca values of these marine sediments vary from 0.10 to 1.21‰ and depend on lithology. Carbonate-rich sediments from Site 144 exhibit δ44/40Ca values in the range of 0.10–0.58‰ with a weighted average value of 0.36‰, which is ∼0.6‰ lower than that of the mantle. In comparison, δ44/40Ca of clay-rich sediments from Site 543 range from 0.79 to 1.21‰ with a mantle-like mean value of 0.96‰. The data obtained here suggest that carbonate- and clay-rich marine sediments differ significantly both in Ca isotopic compositions and CaO contents. Recycling of these sediments will result in different effects on the isotopic compositions of the local mantle and probably affect the local arc lavas. Specifically, carbonate-rich sediments from Site 144 with high CaO contents and light Ca isotopic compositions can alter the local mantle to lower δ44/40Ca signatures, which is expected in the southern Lesser Antilles arc lavas. [ABSTRACT FROM AUTHOR]