The link between subduction and continental exhumation is explored using high‐resolution thermal histories from southern Great Xing'an Range (GXR), NE Asia and integrated with a regional ...low‐temperature thermochronology data synthesis from the NE Asian continental margin. The GXR thermal histories are constrained by multiple thermo‐, geochronometers (zircon, titanite, apatite U‐Pb, zircon, apatite (U‐Th)/He and apatite fission track). These data yield a large range in U‐Pb ages (292–119 Ma) with enhanced exhumation mainly during the early Cretaceous (ca. 155–110 Ma) in an extensional regime linked to roll‐back of the Paleo‐Pacific Ocean and consequent lithospheric thinning and delamination. Integrated with Cretaceous‐Cenozoic low‐temperature thermochronological data from the NE Asian continent margin, three regional phases of exhumation are recognized, which can be linked to changes in the geometry and kinematics of the subduction systems of the Paleo‐Pacific and Pacific oceans, demonstrating coupling between the subducting plate and the continental margin at active plate boundaries.
Plain Language Summary
Thermochronological data sets enable orogen‐scale investigations into the spatio‐temporal patterns of exhumation on continental margins, and provide additional constraints on how the tectonic evolution of the crust is controlled by subduction. We employ geochronology (zircon U‐Pb), low‐temperature thermochronology (zircon, apatite (U‐Th)/He) and medium‐high temperature thermochronology (titanite, apatite U‐Pb) data to model the thermal evolution histories of the southernmost segment of the GXR in NE China. The inverse modeling results show rapid cooling and exhumation from ca. 155–110 Ma. This coincides with the initiation of slab roll‐back of the Paleo‐Pacific Ocean in NE Asia, which was responsible for cooling and exhumation in an extensional regime. In addition, we compile the available low‐temperature thermochronology data (zircon, apatite fission track and (U‐Th)/He) from the NE Asian continental margin from Late Cretaceous (ca. 110 Ma) to constrain regional exhumation events. These data show three main exhumation phases from the Late Cretaceous onwards. Combined with the data on the regional evolution of magmatism, sedimentary basins and deformation, the three exhumation phases can be linked to changes in the geometry of the Paleo‐Pacific ocean and Pacific ocean plates in NE Asia, thus showing coupling between continental exhumation and subduction.
Key Points
The southernmost Great Xing'an Range experienced rapid cooling and exhumation during Early Cretaceous accompanied by voluminous magmatism
A synthesis of low‐temperature thermochronology data from NE Asia shows three pulses of Mesozoic to Cenozoic exhumation
Three exhumation phases on the East Asia margin are linked to subduction of the Paleo‐Pacific Ocean/Pacific Ocean from the late Early Cretaceous
This study explores the epidemiology of patients with a fracture of the scaphoid presenting to a regional teaching hospital.
All patients with a confirmed fracture of the scaphoid over a ...retrospective period between January 2010 and May 2013 were included. Their demographics, deprivation status and when the fracture occurred was noted and assessed. There were 415 fractures in 365 males and 50 females.
The incidence of fracture of the scaphoid was 12.4 in 100 000 each year in the general population. The mean age of the patients was 22 years (nine to 35); the highest incidence was in males aged between 15 and 19 years. We calculate the annual incidence in the United Kingdom to be 7265 each year. Patients with the lowest socioeconomic status had an incidence of 18.57 in 100 000 whereas the least deprived patients had an incidence of 9.98 (p < 0.001). There was evidence of a seasonal trend (p = 0.022) with the highest monthly rate found in June (16.96 in 100 000 each year) and the lowest was in December (7.61 in 100 000 each year). There were significantly fewer presentations of fracture at the weekend (p < 0.001), and the highest incidence was on Mondays. Most fractures occurred at the waist (64%) and tubercle (18.1%).
In this large-scale epidemiological study, we confirmed that young men are most at risk of sustaining a fracture of the scaphoid, and report new factors in relation to social deprivation and seasonality that influence scaphoid fractures. Cite this article: Bone Joint J 2016;98-B:654-9.
Considering the expected increasing demand for cellulose fibers in the near future and that its major source is wood pulp, alternative sources such as vegetable wastes from agricultural activities ...and agro-food industries are currently being sought to prevent deforestation. In the present study, cellulose was successfully isolated from six agroindustrial residues: corncob, corn husk, grape stalk, pomegranate peel, marc of strawberry-tree fruit and fava pod. Cellulose fibers were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, stereomicroscopy and scanning electron microscopy (SEM). Despite the evident morphological differences among the extracted celluloses, results revealed similar compositional and thermal properties with the wood-derived commercial microcrystalline cellulose used as a control. Trace amounts of lignin or hemicellulose were detected in all cellulose samples, with the exception of corncob cellulose, that exhibited the greatest extraction yield (26%) and morphological similarities to wood-derived microcrystalline cellulose, visible through SEM. Furthermore, corncob cellulose was found to have thermal properties (T
Onset
of 307.17 °C, TD of 330.31 °C, and Δ
H
of 306.04 kJ/kg) suitable for biomedical applications.
We combine particle-based simulations, mean-field rate equations, and Wertheim’s theory to study the dynamics of patchy particles in and out of equilibrium, at different temperatures and densities. ...We consider an initial random distribution of nonoverlapping three-patch particles, with no bonds, and analyze the time evolution of the breaking and bonding rates of a single bond. We find that the asymptotic (equilibrium) dynamics differs from the initial (out of equilibrium) one. These differences are expected to depend on the initial conditions, temperature, and density.
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This work reports the development of porous poly (ε-caprolactone) (PCL)-based intraocular implants, prepared by green supercritical carbon dioxide (scCO2) foaming/mixing method (SFM), ...to produce implants that degrade faster than typical slow-degrading PCL-based implants. The higher porosities and surface areas of these implants led to faster degradation rates at in vitro accelerated alkaline conditions than low porosity/surface area implants prepared by hot melting processing. These porous implants also presented distinct (faster) release rates of a test-drug (dexamethasone). Additionally, these porous devices did not cause cell death and did not reduce the number of neurons, indicating that are not toxic to retinal cells. We further explored the impact of PCL-based implant to the retina by in vivo evaluation and histological analysis. Implants were surgically inserted in the vitreous of Wistar rats, and their presence did not change the function, structure and anatomy of the retina. These devices demonstrated a good intraocular tolerance, further confirming their viability for prolonged drug delivery applications. Further comprehensive studies based on this promising preliminary assessment and proof-of-concept could enable its future translation to clinical protective strategies for retinal diseases.
We developed a generalized Smoluchowski framework to study linker-mediated aggregation, where linkers and particles are explicitly taken into account. We assume that the bonds between linkers and ...particles are irreversible, and that clustering occurs through limited diffusion aggregation. The kernel is chosen by analogy with single-component diffusive aggregation but the clusters are distinguished by their number of particles and linkers. We found that the dynamics depends on three relevant factors, all tunable experimentally: (i) the ratio of the diffusion coefficients of particles and linkers; (ii) the relative number of particles and linkers; and (iii) the maximum number of linkers that may bond to a single particle. To solve the Smoluchoski equations analytically we employ a scaling hypothesis that renders the fraction of bondable sites of a cluster independent of the size of the cluster, at each instant. We perform numerical simulations of the corresponding lattice model to test this hypothesis. We obtain results for the asymptotic limit, and the time evolution of the bonding probabilities and the size distribution of the clusters. These findings are in agreement with experimental results reported in the literature and shed light on unexplained experimental observations.
An analytical solution of a generalized Smoluchowski equation for linker-mediated aggregation, validated by computer simulations, describes experimental results for the time evolution of clustering.
In order to understand how omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplements affect breast cancer prevention and treatment, a systematic review of articles published in the last 5 years in ...two databases was performed. Of the 679 articles identified, only 27 were included and examined based on five topics, taking into account: the induction type of the breast cancer used in animal models; the characteristics of the induction model by cell transplantation; the experimental design of the ω-3 supplementation-combined or not with a treatment antitumor drug; the fatty acids (FAs) composition used; the analysis of the studies' outcomes. There are diverse and well-established animal models of breast cancer in the literature, with very relevant histological and molecular similarities depending on the specific objective of the study, such as whether the method of tumor induction was transgenic, by cell transplantation, or by oncogenic drugs. The analyses of outcomes were mainly focused on monitoring tumor growth, body/tumor weight, and molecular, genetic, or histological analyses, and few studies evaluated latency, survival, or metastases. The best results occurred when supplementation with ω-3 PUFA was associated with antitumor drugs, especially in the analysis of metastases and volume/weight of tumors or when the supplementation was started early and maintained for a long time. However, the beneficial effect of ω-3 PUFA supplementation when not associated with an antitumor agent remains unclear.
A critical step in tissue engineering is the design and synthesis of 3D biocompatible matrices (scaffolds) to support and guide the proliferation of cells and tissue growth. The most existing ...techniques rely on the processing of scaffolds under controlled conditions and then implanting them in vivo, with questions related to biocompatibility and implantation that are still challenging. As an alternative, it was proposed to assemble the scaffolds in loco through the self-organization of colloidal particles mediated by cells. To overcome the difficulty to test experimentally all the relevant parameters, we propose the use of large-scale numerical simulation as a tool to reach useful predictive information and to interpret experimental results. Thus, in this study, we combine experiments, particle-based simulations, and mean-field calculations to show that, in general, the size of the self-assembled scaffold scales with the cell-to-particle ratio. However, we have found an optimal value of this ratio, for which the size of the scaffold is maximal when the cell–cell adhesion is suppressed. These results suggest that the size and structure of the self-assembled scaffolds may be designed by tuning the adhesion between cells in the colloidal suspension.
Alzheimer's disease (AD) is a progressive, neurodegenerative disease, characterised by decline of memory, cognitive function and changes in behaviour. Generic markers of lipid peroxidation are ...increased in AD and reactive oxygen species have been suggested to be involved in the aetiology of cognitive decline. Carotenoids are depleted in AD serum, therefore we have compared serum lipid oxidation between AD and age-matched control subjects before and after carotenoid supplementation. The novel oxidised phospholipid biomarker 1-palmitoyl-2-(5′-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) was analysed using electrospray ionisation tandem mass spectrometry (MS) with multiple reaction monitoring (MRM), 8-isoprostane (IsoP) was measured by ELISA and ferric reducing antioxidant potential (FRAP) was measured by a colorimetric assay.
AD patients (n=21) and healthy age-matched control subjects (n=16) were supplemented with either Macushield™ (10mg meso-zeaxanthin, 10mg lutein, 2mg zeaxanthin) or placebo (sunflower oil) for six months.
The MRM-MS method determined serum POVPC sensitively (from 10µl serum) and reproducibly (CV=7.9%). At baseline, AD subjects had higher serum POVPC compared to age-matched controls, (p=0.017) and cognitive function was correlated inversely with POVPC (r=−0.37; p=0.04). After six months of carotenoid intervention, serum POVPC was not different in AD patients compared to healthy controls. However, POVPC was significantly higher in control subjects after six months of carotenoid intervention compared to their baseline (p=0.03). Serum IsoP concentration was unrelated to disease or supplementation. Serum FRAP was significantly lower in AD than healthy controls but was unchanged by carotenoid intervention (p=0.003).
In conclusion, serum POVPC is higher in AD patients compared to control subjects, is not reduced by carotenoid supplementation and correlates with cognitive function.
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•POVPC can be determined in serum using a robust and sensitive MS-MRM method.•POVPC is higher in AD patient serum compared to age-matched controls.•POVPC correlates inversely with mini-mental state examination.•POVPC is increased in control sera after carotenoid supplementation.
We study the dynamics of diffusion-limited irreversible aggregation of monomers, where bonds are mediated by linkers. We combine kinetic Monte Carlo simulations of a lattice model with a mean-field ...theory to study the dynamics when the diffusion of aggregates is negligible and only monomers diffuse. We find two values of the number of linkers per monomer which maximize the size of the largest aggregate. We explain the existence of the two maxima based on the distribution of linkers per monomer. This observation is well described by a simple mean-field model. We also show that a relevant parameter is the ratio of the diffusion coefficients of monomers and linkers. In particular, when this ratio is close to ten, the two maxima merge at a single maximum.
We study the dynamics of diffusion-limited irreversible aggregation of monomers, where bonds are mediated by linkers.
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