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A novel method for preparation of hybrid material of nickel and nickel oxide (Ni-NiO) nanoparticles doping at the three-dimensional (3D) honeycomb-like surface of carbonated polyvinylpyrrolidone K30 (CPVP) via a one-pot, co-pyrolysis strategy was developed. The morphology and composition of Ni-NiO@CPVP nanocomposite were well characterized by microscopy and spectroscopy, indicating its high specific surface area with the loading of catalytic Ni. These features enable large electrochemically active surface area, rapid electron transfer, especially facilitate the discrimination of analytes which oxidize or reduce at similar potentials. After fixation of Ni-NiO@CPVP composite, the modified electrode exhibited excellent sensing ability towards dopamine (DA), ascorbic acid (AA) and uric acid (UA). Broad liner ranges (5.0–4200 μmol/L, 0.05–75 μmol/L and 0.2–120 μmol/L) and low limits of detection (LODs) (1.0, 0.03 and 0.05 μmol/L) were achieved for AA, DA and UA, respectively. Moreover, this sensor offered a good opportunity for simultaneous profiling of AA, DA and UA with excellent reproducibility, repeatability and long-term stability. The good performance for the measurement of real samples indicated the promising future of this sensor. Finally, the possible sensing mechanism was proposed.

A novel electrochemical non-enzymatic sensing system was fabricated based on carbon paste electrode (CPE) encapsulating copper metal-organic frameworks (Cu-MOF/CPE) for determination of glucose by chronoamperometry in alkaline media. The as-synthesized Cu-MOF exhibited high surface area and porous structures, and the presence of carbon pastes greatly improved the conductivity of the sensing electrode. This synergic effect led to the good catalytic activity of the resulting electrode toward glucose. Under the optimized experimental conditions, the oxidation peak currents were linearly dependent on glucose concentrations in a wide range of 5–3910 μmol/L and 3910–10950 μmol/L with a limit of detection (LOD) of 0.11 μmol/L and a short response time of 0.5 s. Moreover, the developed sensor showed long-time stability, excellent selectivity as well as high resistance towards interferences. This sensor was also applied to determination of glucose in serum samples with a satisfactory result, confirming its promising applications.

The uncertain threat status of species inevitably influences their focus on conservation. Just as in extinction risk, the non-randomness phenomenon related to uncertainty (also referred to as selectivity), which is a certain character cluster in some groupings, also exists in data deficiency of species' knowledge. In order to illustrate this kind of non-random phenomenon and explain the uncertainties it caused, we performed a hypergeometric test on taxonomic and geographic groupings of China's spermatophyte species and quantified two factors— frequency of collections and spatial accessibility— to indicate the primary causes of spatial knowledge deficiencies. We found that selectivity in data deficiency exists both taxonomically and geographically. Fifteen of the families were more deficient than expected, which included 30.0% of species and 56.3% ranked data deficient (DD). Among these, eight families were statistically highly significant with p

Dexamethasone (Dex) can induce injury to human osteoblasts. Long non-coding RNA (LncRNA) EPIC1 (Lnc-EPIC1) is a novel Myc-interacting LncRNA. Its effect on Dex-treated human osteoblasts is studied here. In OB-6 osteoblastic cells and primary human osteoblasts, treatment with Dex increased expression of Lnc-EPIC1. Its expression is also elevated in the necrotic femoral head tissues of Dex-taking patients. Ectopic overexpression of Lnc-EPIC1 inhibited Dex-induced apoptosis and programmed necrosis in OB-6 cells and primary human osteoblasts. Reversely, Lnc-EPIC1 silencing by targeted siRNA potentiated Dex-induced cytotoxicity. Myc is the target of Lnc-EPIC1 in osteoblasts. Exogenous overexpression of Myc protected OB-6 cells from Dex. Conversely, Myc knockout by CRISPR-Cas-9 method abolished Lnc-EPIC1-induced OB-6 cytoprotection against Dex. Together, Lnc-EPIC1 expression protects human osteoblasts from Dex possible via regulation of Myc.

Elastic metamaterials (EMMs) with engineered bandgaps have numerous applications in medical, transport, and aerospace domains due to their extraordinary performance in manipulating elastic waves. Nevertheless, developing an efficient method to guide designs of EMMs with low-frequency and wide frequency stopband is still a challenging problem in this field. In this paper, a quantitative local resonance analysis scheme is proposed for efficient design of three-dimensional (3D) latticed EMMs with broad and complete wave attenuation band at low frequency. To acquire a low starting frequency, a diatomic mass spring analytic model is applied to guide the modification of structure and adjustment of geometrical parameters of the EMM, and thus its effective stiffness and mass values affecting the starting frequency are altered desirably. With the aim of enlarging stopband, a strategy to analyze stopband formation mechanism is proposed by virtue of modal superposition principle. Dominant vibration modes developed on the EMM are found with modal superposition principle and these modes are further characterized with the aid of a quantitative local resonance measurement method aiming at exploring vibration features on the EMM. Upon the revealing of wave attenuation mechanism, we show the low-frequency stopband for the EMM can be widened via altering vibration characteristics of dominant modes that are responsible for stopband closing. The proposed new analysis scheme as well as the EMM structure facilitate the development of structure designs for elastic wave attenuation.

It is necessary to establish a reference atmosphere in a thoron chamber containing various ratios of 212 Bi to 212 Pb activity concentrations (C( 212 Bi)/C( 212 Pb)) to simulate typical environmental conditions (e.g., indoor or underground atmospheres). In this study, a novel method was developed for establishing and controlling C( 212 Bi)/C( 212 Pb) in a thoron chamber system based on an aging chamber and air recirculation loops which alter the ventilation rate. The effects of main factors on the C( 212 Bi)/C( 212 Pb) were explored, and a steady-state theoretical model was derived to calculate the ratio. The results show that the C( 212 Bi)/C( 212 Pb) inside the chamber is mainly dependent on ventilation rate. Ratios ranging from 0.33 to 0.83 are available under various ventilation. The stability coefficient of the ratios is better than 7%. The experimental results are close to the theoretical calculated results, which indicates that the model can serve as a guideline for the quantitative control of C( 212 Bi)/C( 212 Pb).

Long-term stability and homogeneity of activity concentration in a calibration facility are vital to quality assurance and quality control for measuring thoron and its progeny. The long half-life of 212 Pb leads to difficulty for attaining highly stable activity; thus, the development of a compensation system based on air recirculation between the ageing chamber and thoron chamber is presented to make up for thoron progeny losses incurred due to plate-out, decay and sampling in the thoron chamber. Stable concentration of thoron progeny in the ageing chamber is dependent on a constant solid 220 Rn source and certain aerosol concentration. A recirculation loop with various flow-rates below 1.6 m 3 h −1 simulates air sampling of instruments being calibrated in the thoron chamber to eliminate concentration fluctuations. A theoretical model is derived for estimating the effect of main variables on the stable concentrations of 212 Pb. Variable but stable activity concentrations of 212 Pb are produced under different compensation and simulation flow-rates by this method with the coefficient of variation below 10% for the activity concentrations of thoron progeny. Concentration ratios of C( 212 Bi)/C( 212 Pb), ranging between 0.33 and 1, are achieved under different ventilation rates for the system.

Preclinical diastolic dysfunction (PDD) is a well-known but poorly understood risk factor for heart failure. We aimed to investigate risk factors contributing to progression of PDD to heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF). Patients with echocardiogram from 2003 to 2008 with left ventricular ejection fraction ≥50%, grade I diastolic dysfunction, and free of clinical heart failure were included. The end point was incident HFpEF or HFrEF. Cumulative probabilities were estimated and multivariable adjusted Cox proportional hazards regressions were performed to examine predictors of incident HFpEF and HFrEF. In total, 7,878 patients with PDD (79.2% nonwhite) were included. At the end of follow-up (median 5.9 years), 146 patients developed HFrEF, and 635 patients developed HFpEF. The 10-year cumulative probabilities of HFrEF and HFpEF were 3.1% and 12.6%, respectively. Incidence of HFrEF was significantly lower in non-Hispanic blacks (2.2%) compared with non-Hispanic whites (4.5%). Age, diabetes, myocardial infarction, and renal disease were independent predictors of both HFrEF and HFpEF. Male gender, cerebrovascular accident, and low baseline left ventricular ejection fraction were associated with HFrEF only; whereas pulmonary disease, blood urea nitrogen, and anemia were predictors of HFpEF only. In conclusion, our results revealed a distinct set of predictors of HFrEF and HFpEF in patients with PDD and underscored a differential approach of risk stratification, prevention, and early treatment based on heart failure subtypes.

Many biological materials contain nanofibers of helical shape to achieve multiple biological functions and superior mechanical properties. In this paper, we establish a microstructure-based crack-bridging model to investigate how the chiral morphologies of nanofibers contribute to the fracture properties of these natural nanocomposites. By using a cohesive interfacial model, the force–displacement relation for a helical nanofiber during pullout is first derived. It is found that the fracture toughness of biological materials is sensitive to the chiral morphology of fibers, suggesting a strategy to attain superior strength, toughness and elasticity. We discover an optimum helical angle that maximizes the toughness. A scaling law is provided to predict the macroscopic fracture toughness of helical fiber-reinforced nanocomposites in terms of microscopic geometric and mechanical parameters. This work not only sheds light on the toughening mechanisms of biological materials but also offers inspirations for design and optimization of advanced composites.

Avian reovirus (ARV) has been responsible for many cases of chicken tenosynovitis in China in recent years, causing high morbidity among layer and broiler chickens. To study the degree of genetic divergence and evolution among ARVs, the full-length nucleotide sequences of the σC-encoding gene of eight ARV field isolates and the entire coding-region sequences of four isolates were determined and analyzed. The sequence analysis revealed that the eight σC-encoding genes shared 99.0–99.9% nucleotide sequence identity with each other and over 99% with the chicken reovirus reference strain S1133. However, the nucleotide sequences of the eight σC-encoding genes varied extensively from that of isolate AVS-B (GenBank accession no. FR694197), with only 55.5% identity. A sequence analysis of the whole ARV-coding region showed some nucleotide substitutions in the open reading frames encoding λA, λB, λC, μA, μB, μNS, σC, σA, σB, and σNS in the field strains. A phylogenetic analysis showed that all eight isolates clustered in group I with S1133, but that four field isolates shared less homology with strain S1133 than the others, indicating that they had been evolved in the field. We also studied the pathogenicity of two strains. No characteristic lesions were observed in vaccinated chickens, and no virus was detected in sampled tissues. However, an enzyme-linked immunosorbent assay revealed significant differences between the antibody responses of the inoculated groups and the negative controls. These results revealed that Chinese isolates shared the highest sequence homologies with S1133, grouped together in one cluster. Although the vaccination against ARV is used in farms, the pathogens still persist in Chinese poultry flocks.

This paper reports an improved combustion apparatus for the determination of organically bound tritium in environmental samples. The performance of this apparatus including the recovery rate and reproducibility was investigated by combusting lettuce and pork samples. To determine the factors for the different recovery rates of lettuce and pork and investigate whether the samples were completely oxidized, the ashes and exhaust gases produced by the combustion were analyzed. The results indicate that the apparatus showed an excellent performance in the combustion of environmental samples. Thus, the improvements conducted in this study were effective.

This paper describes a new numerical approach for modeling the microscopic and macroscopic thermal behaviors of cement composites filled with multiple natural fibers coated with thin homogeneous interphase layers. The coated fibers are assumed to have regular or non-regular distributions in the cementitious matrix. In the present method, special n-sided interphase/fiber elements are developed with special two-phase fundamental solution kernels analytically satisfying the heat transfer equations in the fiber and interphase constituents and the continuum conditions between them to entirely discretize each coated fiber, in despite of the thickness of interphase layer. As a result, the number of nodes and computing costs can be significantly reduced. For such elements, all integrals involved are evaluated along the element boundary such that any polygonal elements with n sides can be constructed. Simultaneously, it's allowed for accurate calculation of the thermal fields anywhere within material phases including the matrix, fibers and interphases. Numerical experiments are conducted to study the interaction of multiple coated fibers and evaluate the effective thermal conductivities of the composites. Comparisons with numerical benchmark results from the conventional finite element method are made to demonstrate the property of the presented special n-sided interphase/fiber elements.

Hierarchical helical structures widely exist in both artificial and biological materials. Such nanomaterials as carbon nanotube ropes with hierarchical helical structures hold a promise for potential applications, for instance, in aerospace and medical engineering. In the present paper, a bottom-up theoretical model is established to investigate the mechanical properties of this kind of novel nanomaterials. The geometry of a rope with a hierarchy of chirality is first formulated. On the basis of the analysis of the internal forces and deformations of a single helical ply, a theoretical model is provided to predict the mechanical responses of multi-level helical materials. The effect of hierarchical helical structures is revealed by comparing the properties between a carbon nanotube rope with two-level helical structure and its counterpart bundle consisting of straight carbon nanotubes. The dependence of the mechanical properties of materials on the initial helical angles, fiber numbers, and handednesses at different structural levels are examined. Carbon nanotube ropes are found with higher deformation ability and elastic property which can be easily tuned via their microstructural parameters. This work helps understand the behavior of chiral materials and also provides inspirations for optimal design of advanced nanomaterials with hierarchical helical structures.

Radon monitors based on electrostatic collection have been widely used in different radon studies. Collection efficiency of this kind of instrument first depends on the cell geometry and electrostatic field intensity. In the process of new instrument development, some researchers found that electrostatic collection efficiency of 218 Po was almost saturated when the voltage between the cylindrical vessel and the detector was higher than 1500 V. In this paper, we analyze the physical processes of the freshly positively charged 218 Po formed from the α decay of 222 Rn and the neutralization kinetics for positively charged 218 Po cluster. The analytical expressions of the collection probability of any freshly positively charged 218 Po cluster and the total collection efficiency in electrostatic collection cell are obtained. The ratio of the relative growth rate of the collection efficiency to the relative growth rate of the voltage is inversely proportional to the voltage. Such an approach is useful to understand the mechanism of the electrostatic collection of 218 Po.

A novel microbial fuel cell with nanostructured TiO2 semiconductor photocathode is designed with a proton exchange membrane to separate the anode chamber and the cathode chamber to overcome the thermodynamic barrier for hydrogen production from acetate without the aid of power supply. Hydrogen can be produced on n-type TiO2 semiconductor photocathode with 0.2 mol L−1 Na2SO4 as catholyte while acetate can be oxidized on bio-anode with additional electricity generated under light irradiation, spontaneously. With an external resistance of 10,000 Ω, the maximum power density of 6.0 mW m−2 and the maximum hydrogen production rate of 4.4 μL h−1 can be achieved. This design has potential application for the effective hydrogen production and provides a new method for utilization of the chemical energy in organic wastes by microbial fuel cells.

The control mechanisms of the strength and toughness of carbon nanotube (CNT) fibers are revealed by analyzing the load-bearing and deformation characteristics of multi-scale structures in the fiber under tensile loading. A theoretical model is established to investigate the effect of the multi-scale structures on the strength and toughness of CNT fibers. Based on our previous experimental results on tension with in situ micro-Raman monitoring [Li et al., Nanotechnology 22, 2011], the macro- and micro-mechanical behaviors of the fiber are analyzed. The tensile behaviors of the fiber are correlated with the load-bearing and deformation processes involved in the multi-scale structures in the fiber, such as the nanotube bundle and the thread in microscopic scale, and the CNT in nanoscale. The CNT fiber exhibits high strength and toughness simultaneously depending on the multi-scale structure of the material, the differences in the properties between bundles and threads, and the unique interfaces formed by the tabular geometric configuration of double-walled CNTs. A constitutive relationship for CNT fiber materials is developed to provide information on the role of multi-scale structures on the strength and toughness of fibers. Both strength and toughness of CNT fibers can be enhanced by increasing the volume ratio of bundles to threads, the interfacial shear strength, and the interface slippage friction resistive force among the CNTs.

Clonorchiasis caused by the oriental liver fluke Clonorchis sinensis is a fish-borne zoonosis endemic in a number of countries. This article describes the development of a TaqMan based real-time PCR assay for detection of C. sinensis DNA in human feces and in fishes. Primers targeting the first internal transcribed spacer (ITS-1) sequence of the fluke were highly specific for C. sinensis, as evidenced by the negative amplification of closely related trematodes in the test with the exception of Opisthorchis viverrini. The detection limit of the assay was 1pg of purified genomic DNA, 5EPG (eggs per gram feces) or one metacercaria per gram fish filet. The assay was evaluated by testing 22 human fecal samples and 37 fish tissues microscopically determined beforehand, and the PCR results were highly in agreement with the microscopic results. This real-time PCR assay provides a useful tool for the sensitive detection of C. sinensis DNA in human stool and aquatic samples in China and other endemic countries where O. viverrini and Opisthorchis felineus are absent.

Mutations in LMNA, which encodes A-type nuclear lamins, cause disorders of striated muscle that have as a common feature dilated cardiomyopathy. We have demonstrated an abnormal activation of both the extracellular signal-regulated kinase (ERK) and the c-Jun N-terminal kinase (JNK) branches of the mitogen-activated protein kinase signaling cascade in hearts from LmnaH222P/H222P mice that develop dilated cardiomyopathy. We previously showed that pharmacological inhibition of cardiac ERK signaling in these mice delayed the development of left ventricle dilatation and deterioration in ejection fraction. In the present study, we treated LmnaH222P/H222P mice with SP600125, an inhibitor of JNK signalling. Systemic treatment with SP600125 inhibited JNK phosphorylation, with no detectable effect on ERK. It also blocked increased expression of RNAs encoding natriuretic peptide precursors and proteins involved in the architecture of the sarcomere that occurred in placebo-treated mice. Furthermore, treatment with SP600125 significantly delayed the development of left ventricular dilatation and prevented decreases in cardiac ejection fraction and fibrosis. These results demonstrate a role for JNK activation in the development of cardiomyopathy caused by LMNA mutations. They further provide proof-of-principle for JNK inhibition as a novel therapeutic option to prevent or delay the cardiomyopathy in humans with mutations in LMNA.

Using a similar procedure to the Hamiltonian system based model [Wang, J.S., Qin, Q.H., 2007. A symplectic model for piezoelectric wedges and its application to analysis of electroelastic singularities, Philosophical Magazine 87 (2), 225–251], the mixed-variable state space formulation is developed for functionally graded piezoelectric material (FGPM) strips and laminates, in which the material inhomogeneity is considered. For dissimilar homogeneous piezoelectric laminates, the state space formulation degenerated to a Hamiltonian system. Applying the developed model, we analyzed the decay of Saint-Venant end effects in a single FGPM strip and a FGPM laminate. The numerical results show that the decay rate depended strongly on the eigenvalue of the proposed operator matrix for the single FGPM strip. By using the coordinate transformation technique and the continuity conditions on the interface between two dissimilar materials (different piezoelectric properties or different material inhomogeneous parameters), the decay rates are also determined for multi-layered FGPM laminates, including dissimilar piezoelectric laminates (without material inhomogeneity) as a special case. Numerical results are presented to show the applicability of the proposed state space model to piezoelectric and FGPM laminates. In addition, the variation of the decay rate with the thickness has also been investigated for the dissimilar homogeneous piezoelectric laminates. This study indicates that material inhomogeneity plays an important role in Saint-Venant end effects for FGPM laminates, as in the case of a single FGPM strip [Borrelli, A., Horgan, C.O., Patria, M.C., 2004. Exponential decay of end effects in anti-plane shear for functionally graded piezoelectric materials. Proceedings of the Royal Society of London Series A 460, 1193–1212].

Electrodeposition of Pt-Pb nanoparticles (PtPbNPs) to multi-walled carbon nanotubes (MWCNTs) resulted in a stable PtPbNP/MWCNT nanocomposite with high electrocatalytic activity to glucose oxidation in either neutral or alkaline medium. More importantly, the nanocomposite electrode with a slight modification exhibited high sensitivity, high selectivity, and low detection limit in amperometric glucose sensing at physiological neutral pH (poised at a negative potential). At +0.30 V in neutral solution, the nanocomposite electrode exhibited linearity up to 11 mM of glucose with a sensitivity of 17.8 microA cm(-2) mM(-1) and a detection limit of 1.8 microM (S/N=3). Electroactive ascorbic acid (0.1 mM), uric acid (0.1 mM) and fructose (0.3 mM) invoked only 23%, 14% and 9%, respectively, of the current response obtained for 3 mM glucose. At -0.15 V in neutral solution, the electrode responded linearly to glucose up to 5 mM with a detection limit of 0.16 mM (S/N=3) and detection sensitivity of approximately 18 microA cm(-2) mM(-1). At this negative potential, ascorbic acid, uric acid, and fructose were not electroactive, therefore, not interfering with glucose sensing. Modification of the nanocomposite electrode with Nafion coating followed by electrodeposition of a second layer of PtPbNPs on the Nafion coated PtPbNP/MWCNT nanocomposite produced a glucose sensor (poised at -0.15 V) with a lower detection limit (7.0 microM at S/N=3) and comparable sensitivity, selectivity and linearity compared to the PtPbNP/MWCNT nanocomposite. The Nafion coating lowered the detection limit by reducing the background noise, while the second layer of PtPbNPs restored the sensitivity to the level before Nafion coating.