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In this paper, we consider a stochastic epidemic model with time delay and general incidence rate. We first prove the existence and uniqueness of the global positive solution. By using the Krylov–Bogoliubov method, we obtain the existence of invariant measures. Furthermore, we study a special case where the incidence rate is bilinear with distributed time delay. When the basic reproduction number R 0 < 1 , the analysis of the asymptotic behavior around the disease-free equilibrium E 0 is provided while when R 0 > 1 , we prove that the invariant measure is unique and ergodic. The numerical simulations also validate our analytical results. • The well-posedness of a stochastic delayed SIRS model with general incidence rate is studied. • Establish a general condition on the drift and diffusion coefficients for the existence of invariant measures. • The asymptotic behavior around the disease-free equilibrium is studied. • Obtain a sufficient condition for the uniqueness and the ergodicity of the invariant measure. [ABSTRACT FROM AUTHOR]

A novel DNA-modified nanocomposite of three-dimensional reduced graphene oxide and chitosan particles (CS@3D-rGO@DNA) was prepared by one-step method and used as a new electrochemical biosensing strategy to detect Hg 2+ in drinking water. This biosensor was fabricated by the chemical coordination of T-Hg 2+ -T between the T-rich oligonucleotide strands contained in the as-prepared CS@3D-rGO@DNA nanocomposite and Hg 2+ , thereby varying the electrochemical signals. The developed electrochemical biosensor exhibited high sensitivity toward the determination of Hg 2+ with a low detection limit of 0.016 nM, ranging from 0.1 nM to 10 nM. This novel biosensor also showed high selectivity, good stability, and repeatability. Hence, this proposed CS@3D-rGO@DNA-based electrochemical strategy is feasible and may offer a simple, rapid, cost-effective, highly selective, and sensitive method for Hg 2+ quantification. [ABSTRACT FROM AUTHOR]

Abstract: In order to study the irradiation performance of fuel spheres for the 10MW high-temperature gas-cooled reactor (HTR-10), two in-pile irradiation tests were performed. The first irradiation test was performed in the Russian reactor IVV-2M from July 2000 to February 2003. The four irradiated fuel spheres were randomly taken from the first product batches. The central temperature of irradiated fuel spheres during this irradiation was kept between 950 and 1050°C. The maximum burnup of the irradiated spheres was 107,000MWd/tU and the maximum fast neutron fluence (E >0.1MeV) was 1.31×1025 m−2. The release-to-birth rate ratios (R/B) of Kr and Xe fission products were 10−7 to 10−5. The second irradiation test was performed in HFR Petten (HFR-EU1) from September 29, 2006 to February 19, 2010. Experiment HFR-EU1 consisted of 3 German AVR pebbles and 2 INET pebbles. The two INET pebbles were randomly taken from the latest production batch. The surface temperature of pebble INET 2 during irradiation was approx. 940°C. The experiment was performed in two campaigns from 29 September 2006 to 24 February 2008 (12 reactor cycles of 28 days) and continued from 19 October 2009 to 19 February 2010 (4 reactor cycles). Up to end of irradiation, the experiment had accumulated 16 reactor cycles totaling 445 efpd and calculated burnup and maximum fast neutron fluence (E >0.1MeV) were 9.3% (pebble INET 1) and 11.6%FIMA (pebble INET 2) and about 4.95×1025 m−2, respectively. At end of irradiation, based on 85mKr, R/B of approx. 8×10−8 was measured. The second irradiation test results are much better than the first. The irradiated sample manufacture technology and characterization, irradiation conditions and results of two irradiation tests are compared in detail in this paper. [Copyright &y& Elsevier]

Abstract: An irradiation test of four spherical fuel elements (SFE) had been performed in the Russian reactor IVV-2M. The elements were sampled randomly from the first and second product batches which were manufactured for the 10MW high-temperature gas-cooled test reactor (HTR-10). The maximum burnup of the irradiated fuel elements reached 107,000MWd/tU and the maximum fast neutron fluence was 1.31×1025 m−2. The release-to-birth rate ratio (R/B) did not increase significantly during irradiation. However, an in-pile heating-up test of element SFE 7 in Capsule 5 led to a failure of approximately 6% of the coated particles. After the test it was estimated that the fuel temperature had very likely been much higher than the intended 1600°C. [Copyright &y& Elsevier]

• Enzyme-like catalyst S/CuMgAL-41 with confined space was successfully constructed by coprecipitation and thiourea modification. • The S/CuMgAl-41 is a bifunctional catalyst with both acidic and alkaline active site. • NO 3 2− and SO 4 2− come from calcination of CuMgAL-41 modified by thiourea not only enhance the electrophilicity of aldehydes but also anchor of p -NBD with NO 3 2− and SO 4 2− by hydrogen, thereby increase the selectivity of the entantiomers and ee value. • The asymmetric aldol addition of p -NBD with acetone catalyzed S/CuMgAL-41 is the synergistic result of diverse factors such as the acid-base active center on the S/CuMgAL-41, hydrogen bonding, confined effect, anchoring effect. In this study, a series catalysts of CuMgAl-LDHs were successfully prepared by co-precipitation method. Subsequently, the catalyst S/CuMgAl-41 was prepared by modifying CuMgAl-41 with thiourea. The physical and chemical properties of the catalyst were characterized by XRD, N 2 adsorption-desorption, SEM, ICP, FT-IR, TG-DSC and XPS. The catalytic performance of the catalyst was investigated. It showed that S/CuMgAl-41 exhibited synergistic catalytic activity with better ee value due to both acidic and alkaline active sites and confined spaces with proper interlayer spacing. When isopropyl alcohol was chosen as solvent, the S/CuMgAl-41 has the best catalytic effect for asymmetric aldol addition reaction between p -nitrobenzaldehyde (p -NBD) and acetone. Additionally, the process conditions for optimizing the asymmetric addition reaction have been thoroughly studied. It was found that S/CuMgAl-41 exhibited good reusability and stability. Moreover, the asymmetric aldol addition of acetone and p -NBD catalyzed by S/CuMgAL-41 can occur due to the result of synergistic effects of various factors, including acid-base active center, hydrogen bond, confined effect and anchoring effects between hydrotalcite laminate of S/CuMgAL-41. This novel catalytic design provides a new idea for asymmetric synthesis of p -NBD and acetone. In this study, a series catalysts of CuMgAl-LDHs were successfully prepared by co-precipitation method. Subsequently, the catalyst S/CuMgAl-41 was prepared by modifying CuMgAl-41 with thiourea. The physical and chemical properties of the catalyst were characterized by XRD, N 2 adsorption-desorption, SEM, ICP, FT-IR, TG-DSC and XPS. The catalytic performance of the catalyst was investigated. It showed that S/CuMgAl-41 exhibited synergistic catalytic activity with better ee value due to both acidic and alkaline active sites and confined spaces with proper interlayer spacing. When isopropyl alcohol was chosen as solvent, the S/CuMgAl-41 has the best catalytic effect for asymmetric aldol addition reaction between p -nitrobenzaldehyde (p -NBD) and acetone. Additionally, the process conditions for optimizing the asymmetric addition reaction have been thoroughly studied. It was found that S/CuMgAl-41 exhibited good reusability and stability. Moreover, the asymmetric aldol addition of acetone and p -NBD catalyzed by S/CuMgAL-41 can occur due to the result of synergistic effects of various factors, including acid-base active center, hydrogen bond, confined effect and anchoring effects between hydrotalcite laminate of S/CuMgAL-41. This novel catalytic design provides a new idea for asymmetric synthesis of p -NBD and acetone. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: By applying the duplicate form of Carlitz inversions to three special cases of the -Saalschütz theorem respectively, we establish three classes of interesting summation formulae. [Copyright &y& Elsevier]

Polyetheretherketone (PEEK) is considered a potential orthopedic/dental material because of its excellent mechanical and chemical properties (e.g., similar elastic modulus to that of human bone). However, the poor bacteriostasis and anti-inflammatory and osseointegrative properties of bioinert PEEK impede its clinical application. We previously developed a facile and versatile surface modification method using dexamethasone plus minocycline-loaded liposomes (Dex/Mino liposomes) bonded by a mussel-inspired polydopamine coating, which effectively modulated cell inflammatory response and discouraged bacterial colonization in vitro. Herein, we report the application of this multifunctional surface modification method to improve bioinert PEEK, aimed at further studying the in vitro osteogenesis and in vivo properties of Dex/Mino liposome-modified PEEK to prevent bacterial contamination, attenuate the inflammatory response, and enhance ossification for physiologic osseointegration. Our study established that the Dex/Mino liposome-modified PEEK surface presented favorable stability and cytocompatibility. Compared with bare PEEK, improved osteogenic differentiation of human mesenchymal stem cells under both osteoinductive and osteoconductive conditions was found on the functionalized surface due to the liposomal Dex releasing. In vivo bacteriostasis assay confirmed that Mino released from the functionalized surface provided an effective antibacterial effect. Moreover, the subcutaneous foreign body reaction and beagle femur implantation models corroborated the enhanced anti-inflammatory and osteointegrative properties of the functionalized PEEK. Our findings indicate that the developed Dex/Mino liposome-modified PEEK with enhanced antibacterial, anti-inflammatory, and osseointegrative capacity has great potential as an orthopedic/dental implant material for clinical application. Image 1 [ABSTRACT FROM AUTHOR]

Recent studies reveal 2-aminoadipic acid (2-AAA) is both elevated in subjects at risk for diabetes and mechanistically linked to glucose homeostasis. Prior studies also suggest enrichment of protein-bound 2-AAA as an oxidative post-translational modification of lysyl residues in tissues associated with degenerative diseases of aging. While in vitro studies suggest redox active transition metals or myeloperoxidase (MPO) generated hypochlorous acid (HOCl) may produce protein-bound 2-AAA, the mechanism(s) responsible for generation of 2-AAA during inflammatory diseases are unknown. In initial studies we observed that traditional acid- or base-catalyzed protein hydrolysis methods previously employed to measure tissue 2-AAA can artificially generate protein-bound 2-AAA from an alternative potential lysine oxidative product, lysine nitrile (LysCN). Using a validated protease-based digestion method coupled with stable isotope dilution LC/MS/MS, we now report protein bound 2-AAA and LysCN are both formed by hypochlorous acid (HOCl) and the MPO/H 2 O 2 /Cl − system of leukocytes. At low molar ratio of oxidant to target protein N ε -lysine moiety, 2-AAA is formed via an initial N ε -monochloramine intermediate, which ultimately produces the more stable 2-AAA end-product via sequential generation of transient imine and semialdehyde intermediates. At higher oxidant to target protein N ε -lysine amine ratios, protein-bound LysCN is formed via initial generation of a lysine N ε -dichloramine intermediate. In studies employing MPO knockout mice and an acute inflammation model, we show that both free and protein-bound 2-AAA, and in lower yield, protein-bound LysCN, are formed by MPO in vivo during inflammation. Finally, both 2-AAA and to lesser extent LysCN are shown to be enriched in human aortic atherosclerotic plaque, a tissue known to harbor multiple MPO-catalyzed protein oxidation products. Collectively, these results show that MPO-mediated oxidation of protein lysyl residues serves as a mechanism for producing 2-AAA and LysCN in vivo . These studies further support involvement of MPO-catalyzed oxidative processes in both the development of atherosclerosis and diabetes risk. [ABSTRACT FROM AUTHOR]

Predicting individual socioeconomic status (SES) from social media content benefits various applications in economic and social fields. Most previous works adopt machine learning methods with predefined features to infer SES. Nevertheless, they ignore some important information of social media content, such as order, structure and relation information, which leads to limited performance. In this paper, we propose a COupled social media content REpresentation model (CORE) for individual SES prediction, which efficiently exploits latent complex couplings of social media content. CORE devises a structure-aware social media text representation method to incorporate the order and the hierarchy of social media text, and leverages a coupled attribute representation method to take into account intra-coupled and inter-coupled interaction relationships among user level attributes. Our experiments on a real data set of a Chinese microblogging platform demonstrate that our approach significantly outperforms benchmark methods, which validates its efficiency and robustness. The proposed model could be applied to improve the SES prediction and other user profiling tasks. • A coupled social media content representation model for predicting individual SES is proposed. • A structure-aware social media text representation method is presented. • A coupled attribute representation method exploring intrinsic relationships is devised. • Experiments prove that the proposed model greatly outperforms state-of-the-art models. [ABSTRACT FROM AUTHOR]

Abstract: Oxidized fatty acids formed via lipid peroxidation are implicated in pathological processes such as inflammation and atherosclerosis. A number of methods may be used to detect specific oxidized fatty acids containing a single or multiple combinations of epoxide, hydroxyl, ketone, and hydroperoxide moieties on varying carbon chain lengths from C8 up to C30. Some of these methods are nonspecific and their use in biological systems is fraught with difficulty. Measures of specific oxidized fatty acid derivatives help in identifying oxidation pathways in pathological processes. We used liquid chromatography coupled with electrospray ionization tandem mass spectrometry as an efficient, selective, and sensitive method for identifying and analyzing multiple specific fatty acid peroxidation products in human plasma and other biological matrices. We then distilled the essential components of a number of these analyses to provide an efficient protocol by which fatty acid oxidation products and their parent compounds can be determined. In this protocol, addition of a synthetic internal standard to the sample, followed by base hydrolysis at elevated temperature and liquid–liquid phase sample extraction with lighter-than-water solvents, facilitates isolation of the oxidized fatty acid species. These species can be identified and accurately quantified using stable-isotope dilution and multiple-reaction monitoring. Use of a coupled multiplexed gradient HPLC system on the front end enables high-throughput chromatography and more efficient use of mass spectrometer time. [Copyright &y& Elsevier]

Abstract: In order to evaluate if the fuel elements and their components (matrix material and coated fuel particles) can meet the design requirements of 10MW high temperature gas-cooled reactor (HTR-10), an irradiation testing with four spherical fuel elements, 60 matrix material specimens of 5mm×5mm×40mm and 13,500 coated fuel particles was performed in Russian IVV-2M reactor from July 2000 to February 2003. The irradiation temperature was 1000°C. The fast neutron fluence of matrix material specimens reached 1.3×1021 cm−2 (E >0.1MeV). Post-irradiation examination contained the visual inspection, dimension measurement and determining the density, porosity, specific electrical resistance and bending strength. The irradiation results are given in this paper, and show that the matrix material for spherical HTR-10 fuel elements made from the domestic raw materials and fabricated by the quasi-isostatic room-temperature moulding process is suitable as a structural material for spherical HTR fuel elements. [Copyright &y& Elsevier]

Objectives: We sought to understand the importance of oxidative stress in explaining why the haptoglobin (Hp) genotype determines myocardial infarction (MI) size in diabetes mellitus (DM). Background: Two common alleles (1 and 2) exist at the Hp locus in humans. The Hp 2 allele is associated with increased MI size in individuals with DM. In vitro, the Hp 2 protein is associated with increased generation of oxidatively active iron, whereas the Hp 1 protein is associated with increased production of the antioxidant cytokine interleukin (IL)-10. Methods: Myocardial infarction was produced by myocardial ischemia-reperfusion (IR) in DM C57BL/6 mice carrying the Hp 1 or Hp 2 allele. Myocardial oxidative stress after IR was assessed using electrospray ionization mass spectrometry. Redox active iron and IL-10 were measured in the serum after IR. Results: Myocardial infarction size was significantly larger in Hp 2 mice as compared with Hp 1 mice (44.3 ± 9.3% vs. 21.0 ± 4.0%, p = 0.03), and these larger infarctions were associated with a significant increase in a panel of hydroxyl-eicosatetraenoic acids. Redox active iron was greater in Hp 2 mice (0.45 ± 0.11 μmol/l vs. 0.14 ± 0.05 μmol/l, p = 0.02), whereas IL-10 was greater in Hp 1 mice (85.8 ± 12.9 pg/μl vs. 46.7 ± 10.8 pg/μl, p = 0.04) after IR. Administration of an antioxidant (BXT-51072) to Hp 2 mice reduced myocardial injury after IR by more than 80% (p = 0.003), but no myocardial protection was provided by the antioxidant to Hp 1 mice. Conclusions: The increased MI size in DM Hp 2 mice occurring after IR may be due to increased oxidative stress. [Copyright &y& Elsevier]