Objectives
Copper has been added to scaffolds when investigating bone repair, as an agent to promote vascularization; however, little is known concerning its effect on mesenchymal stem cells (MSCs), ...which are considered to be the origin of osteoblasts. In this study, we have aimed to elucidate effects of copper on osteogenic differentiation of MSCs.
Materials and methods
Rat bone marrow MSCs (rBMSCs) were used as a model. Their viability was assessed by MTT assay and Roche's CASY cell counter test and calcium deposition was evaluated by staining with alizarin red S. Fluorescent phalloidin F‐actin stain was used to evaluate cytoskeletal changes, protein expressions were investigated by western blotting and mRNA levels were analysed using Q‐PCR. A rat model for ectopic bone formation was used to assess effects of copper on MSCs in vivo.
Results
Copper supplementation resulted in inhibition of osteogenesis of rBMSCs, along with reduction in expression of a number of osteogenic genes, alkaline phosphatase activity and formation of bone nodules. Cytoskeletal changes to cells during osteogenesis was inhibited by copper supplementation. In vivo study confirmed that copper could inhibit collagen formation whilst promoting angiogenesis.
Conclusions
Our study demonstrated that copper inhibited osteogenic differentiation of rBMSCs in vitro. The findings caution appropriate use of copper and have laid a foundation for further research.
A comprehensive theory of the Lamb shift in light muonic atoms such as μH, μD, μ3 He+, and μ4He+ is presented, with all quantum electrodynamic corrections included at the precision level constrained ...by the uncertainty of nuclear structure effects. This analysis can be used in the global adjustment of fundamental constants and in the determination of nuclear charge radii. Further improvements in the understanding of electromagnetic interactions of light nuclei will allow for a promising test of fundamental interactions by comparison with "normal" atomic spectroscopy, in particular, with H-D and 3He − 4He isotope shifts.
As a class of brown carbon, organonitrogen compounds originating from the heterogeneous uptake of NH3 by secondary organic aerosol (SOA) have received significant attention recently. In the current ...work, particulate organonitrogen formation during the ozonolysis of α-pinene and the OH oxidation of m-xylene in the presence of ammonia (34–125 ppb) was studied in a smog chamber equipped with a high resolution time-of-flight aerosol mass spectrometer and a quantum cascade laser instrument. A large diversity of nitrogen-containing organic (NOC) fragments was observed which were consistent with the reactions between ammonia and carbonyl-containing SOA. Ammonia uptake coefficients onto SOA which led to organonitrogen compounds were reported for the first time, and were in the range of ∼ 10-3–10−2, decreasing significantly to < 10-5 after 6 h of reaction. At the end of experiments (~ 6 h) the NOC mass contributed 8.9 ± 1.7 and 31.5 ± 4.4 wt % to the total α-pinene- and m-xylene-derived SOA, respectively, and 4–15 wt % of the total nitrogen in the system. Uptake coefficients were also found to be positively correlated with particle acidity and negatively correlated with NH3 concentration, indicating that heterogeneous reactions were responsible for the observed NOC mass, possibly limited by liquid phase diffusion. Under these conditions, the data also indicate that the formation of NOC can compete kinetically with inorganic acid neutralization. The formation of NOC in this study suggests that a significant portion of the ambient particle associated N may be derived from NH3 heterogeneous reactions with SOA. NOC from such a mechanism may be an important and unaccounted for source of PM associated nitrogen. This mechanism may also contribute to the medium or long-range transport and wet/dry deposition of atmospheric nitrogen.
A new trinuclear nickel(II) complex, {NiL(EtOH)(μ-OAc)}
2
Ni·2CH
3
CH
2
OH were synthesized via the reaction of a salamo-type ligand H
2
L with nickel(II) acetate tetrahydrate by wet-chemical method. ...The complex was characterized by single crystal X-ray diffraction and various spectroscopic methods. Crystallographic data showed that all the nickel(II) atoms are located in N,O-donor cavities possess distorted octahedral geometries. Through intermolecular interactions, the complex finally forms a three-dimensional supramolecular structure. Remarkable, there is an obvious lone pair–π interaction between the complex units. Intermolecular interactions are carefully discussed by Hirshfeld surfaces analyses. Meanwhile, fluorescence properties are performed in ethanol.
In this study, a tribo-dynamics model for spur gear pairs is proposed. The model couples a mixed elastohydrodynamic lubrication model of a spur gear pair with a transverse–torsional dynamic model. ...The lubrication model provides the dynamic model with friction forces and moments that couple the vibrations of the gears along the off-line-of-action direction to other gear vibrations. In addition, it predicts damping coefficient at the gear mesh in a physics-based manner from the energy loss associated with viscous shearing across the fluid film. In return, the dynamic model predicts the dynamic tooth forces and surface velocities to be used in the lubrication model. An iterative computational scheme is proposed to implement the lubrication and dynamics models simultaneously to couple tribological and dynamic behaviors of a spur gear pair fully. An example gear pair is analyzed using the proposed model to demonstrate this two-way relationship and quantify the impact of operating conditions, surface roughness and lubrication characteristics on the tribo-dynamics response.
While single-shot detection of silicon spin qubits is now a laboratory routine, the need for quantum error correction in a large-scale quantum computing device demands a quantum non-demolition (QND) ...implementation. Unlike conventional counterparts, the QND spin readout imposes minimal disturbance to the probed spin polarization and can therefore be repeated to extinguish measurement errors. Here, we show that an electron spin qubit in silicon can be measured in a highly non-demolition manner by probing another electron spin in a neighboring dot Ising-coupled to the qubit spin. The high non-demolition fidelity (99% on average) enables over 20 readout repetitions of a single spin state, yielding an overall average measurement fidelity of up to 95% within 1.2 ms. We further demonstrate that our repetitive QND readout protocol can realize heralded high-fidelity (>99.6%) ground-state preparation. Our QND-based measurement and preparation, mediated by a second qubit of the same kind, will allow for a wide class of quantum information protocols with electron spins in silicon without compromising the architectural homogeneity.
Summary
This review analyzes the economic costs of HF in Asia. The availability and quality of studies on the burden of osteoporosis in Asia are very scarce. There is a need to encourage more quality ...cost of osteoporosis studies based on standardized methods to convince healthcare authorities in implementing appropriate strategies.
Introduction
Osteoporosis fractures, especially hip fractures, impose large economic costs to governments and societies. This review aimed to systematically analyze available evidence on healthcare costs associated with osteoporosis-related hip fractures (HF) in Asia.
Methods
Articles were systematically sought from databases including PubMed, EMBASE, and EBSCOHost between 2000 and 2015. Total costs associated with HF care, the cost components, and length of stays were retrieved and analyzed. Study designs were also qualitatively analyzed.
Results
The availability of published studies on economic burden of HF in Asia is severely lacking with only 15 articles met the inclusion criteria. Even among the included studies, only two studies reported comprehensive costs evaluating all costs including indirect or intangible costs. Most studies satisfactorily reported criteria for conducting economic evaluation, but large variations existed in the methodological design. Due to study design and other influencing factors, large variation in the cost of HF treatment from US$774 to US$14,198.90 (median S$2943), representing an average of 18.95% (range: 3.58–57.05%) of the countries’ 2014 GDP/capita, was observed. This highlighted the heavy burden of managing HF in Asia with about 40% of the included studies reported using more than one third of GDP/capita.
Conclusion
There is a paucity of burden of illness studies of osteoporosis in the Asian region. For the few available studies, there was a lack of standardization in methodological approach in evaluating the economic burden of the disease. There is a need to encourage more quality burden of illness studies of osteoporosis to inform policymakers in healthcare planning.
Graphitic carbon nitride (g-C3N4) and boron-doped g-C3N4 were prepared by heating melamine and the mixture of melamine and boron oxide, respectively. X-ray diffraction, X-ray photoelectron ...spectroscopy, and UV−vis spectra were used to describe the properties of as-prepared samples. The electron paramagnetic resonance was used to detect the active species for the photodegradation reaction over g-C3N4. The photodegradation mechanisms for two typical dyes, rhodamine B (Rh B) and methyl orange (MO), are proposed based on our comparison experiments. In the g-C3N4 photocatalysis system, the photodegradation of Rh B and MO is attributed to the direct hole oxidation and overall reaction, respectively; however, for the MO photodegradation the reduction process initiated by photogenerated electrons is a major photocatalytic process compared with the oxidation process induced by photogenerated holes. Boron doping for g-C3N4 can promote photodegradation of Rh B because the boron doping improves the dye adsorption and light absorption of catalyst.
The g-C3N4 photocatalyst was synthesized by directly heating the low-cost melamine. The methyl orange dye (MO) was selected as a photodegrading goal to evaluate the photocatalytic activity of ...as-prepared g-C3N4. The comparison experiments indicate that the photocatalytic activity of g-C3N4 can be largely improved by the Ag loading. The strong acid radical ion (SO4 2− or NO3 −) can promote the degrading rate of MO for g-C3N4 photocatalysis system. The MO degradation over the g-C3N4 is mainly attributed to the photoreduction process induced by the photogenerated electrons. Our results clearly indicate that the metal-free g-C3N4 has good performance in photodegradation of organic pollutant.
Super‐hydrophobic surfaces, with a water contact angle (CA) greater than 150°, have attracted much interest for both fundamental research and practical applications. Recent studies on lotus and rice ...leaves reveal that a super‐hydrophobic surface with both a large CA and small sliding angle (α) needs the cooperation of micro‐ and nanostructures, and the arrangement of the microstructures on this surface can influence the way a water droplet tends to move. These results from the natural world provide a guide for constructing artificial super‐hydrophobic surfaces and designing surfaces with controllable wettability. Accordingly, super‐hydrophobic surfaces of polymer nanofibers and differently patterned aligned carbon nanotube (ACNT) films have been fabricated.
The study of natural lotus leaves reveals that to obtain a super‐hydrophobic surface with both a large contact angle (CA) and small sliding angle (α), cooperation of micro‐ and nanostructures is required. Accordingly, lotus‐like aligned carbon nanotube (ACNT) films with a CA of ∼166° (see Figure) and α of ∼3° have been fabricated. Other super‐hydrophobic surfaces of polymer nanofibers and different patterned ACNT films are also highlighted.
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