m6A demethylase FTO and osteoporosis: potential therapeutic interventions

Osteoporosis is a common bone disease, characterized by a descent in bone mass due to the dysregulation of bone homeostasis. Although different studies have identified an association between osteoporosis and epigenetic alterations in osteogenic genes, the mechanisms of osteoporosis remain unclear. N6-methyladenosine (m6A) modification is a methylated adenosine nucleotide, which regulates the translocation, exporting, translation, and decay of RNA. FTO is the first identified m6A demethylase, which eliminates m6A modifications from RNAs. Variation in FTO disturbs m6A methylation in RNAs to regulate cell proliferation, differentiation, and apoptosis. Besides, FTO as an obesity-associated gene, also affects osteogenesis by regulating adipogenesis. Pharmacological inhibition of FTO markedly altered bone mass, bone mineral density and the distribution of adipose tissue. Small molecules which modulate FTO function are potentially novel remedies to the treatment of osteoporosis by adjusting the m6A levels. This article reviews the roles of m6A demethylase FTO in regulating bone metabolism and osteoporosis

Answers and Solutions

Answers and solutions to the puzzles in this issue

One-Pot Synthesis of nickel-modified carbon nitride layers toward efficient photoelectrochemical cells

[EN] A new method to significantly enhance the photoelectrochemical properties of phenyl-modified carbon nitride layers via the insertion of nickel ions into carbon nitride layers is reported. The nickel ions: are embedded within the carbon nitride layers by manipulating the interaction of Ni ions and molten organic molecules at elevated temperature prior to their condensation. A detailed analysis of the chemical and photophysical properties suggests that the nickel ions dissolve in the molten molecules, leading to the homogeneous distribution of nickel atoms within the carbon nitride layers. We found that the nickel atoms can alter the growth mechanism of carbon nitride layers, resulting in extended light absorption, charge transfer properties, and the total photoelectrochemical performance. For the most photoactive electrode, the Ni ions have an oxidation state of 2.8, as confirmed by soft X-ray absorption spectroscopy. Furthermore, important parameters such as absorption coefficient, exciton lifetime, and diffusion length were studied in depth, providing substantial progress in our understanding of the photoelectrochemical properties of carbon nitride films. This work opens new opportunities for the growth of carbon nitride layers and similar materials on different surfaces and provides important progress in our understanding of the photophysical and photoelectrochemical properties of carbon nitride layers toward their implantation in photoelectronic and other devices.We thank the use Katz Institute for Nanoscale Science & Technology Ben Gurion University for HR-TEM measurements. M.S. thanks Dr. Laurent Chabanne for fruitful discussion. K.M.L. is grateful for the support by the Helmholtz Association (VH-NG-1140).Zhang, W.; Albero-Sancho, J.; Xi, L.; Lange, KM.; García Gómez, H.; Wang, X.; Shalom, M. (2017). One-Pot Synthesis of nickel-modified carbon nitride layers toward efficient photoelectrochemical cells. ACS Applied Materials & Interfaces. 9(38):32667-32677. https://doi.org/10.1021/acsami.7b08022S326673267793

Influences of graphene oxide support on the electrochemical performances of graphene oxide-MnO2 nanocomposites

MnO2 supported on graphene oxide (GO) made from different graphite materials has been synthesized and further investigated as electrode materials for supercapacitors. The structure and morphology of MnO2-GO nanocomposites are characterized by X-ray diffraction, X-ray photoemission spectroscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and Nitrogen adsorption-desorption. As demonstrated, the GO fabricated from commercial expanded graphite (denoted as GO(1)) possesses more functional groups and larger interplane gap compared to the GO from commercial graphite powder (denoted as GO(2)). The surface area and functionalities of GO have significant effects on the morphology and electrochemical activity of MnO2, which lead to the fact that the loading amount of MnO2 on GO(1) is much higher than that on GO(2). Elemental analysis performed via inductively coupled plasma optical emission spectroscopy confirmed higher amounts of MnO2 loading on GO(1). As the electrode of supercapacitor, MnO2-GO(1) nanocomposites show larger capacitance (307.7 F g-1) and better electrochemical activity than MnO2-GO(2) possibly due to the high loading, good uniformity, and homogeneous distribution of MnO2 on GO(1) support

Shape-controlled synthesis and application of one-dimensional cadmium chalcogenide nanocrystals

In recent years, the synthesis of one-dimensional (1D) nanocrystals has attracted considerable interest. The morphologies of the 1D nanocrystals studied include rods, wires, belts and tubes whose lateral dimensions fall within the 1 to 100 nm range. Their potential applications are related to their size- and shape-dependent physicochemical and optoelectronic properties. 1D cadmium chalcogenide nanocrystals have become important potential building blocks for new electronic and optical nanodevices. As the electronic and optical properties are dependent on the crystal dimensions, the issue of how to control the growth of 1D cadmium chalcogenide nanocrystals is of prime importance and this issue remains one of the most challenging issues to address in both chemistry and materials science. This is one of the motivations behind this study. In this work, three catalyst-free and solution-based methods were used for the synthesis of 1D cadmium chalcogenide nanocrystals. These methods are the reverse micelle method, the hydrothermal method and the hot coordinating solvents method. Using both the reverse micelle method and the hydrothermal method, we have successfully synthesized CdSe nanorods. We found that the reverse micelle method has better morphological control than the hydrothermal method, but the latter has both the higher crystallinity and yield. Using the hot coordinating solvents method, good size distribution, controllable growth and an aspect ratio as high as 170 has been achieved. This is significant because in the past fifteen years, this method has only been able to generate low aspect ratio nanorods (less than 20). Contrary to the existing mechanisms, an oriented attachment mechanism was observed and proposed in this study. We also attempted to synthesiz CdSe nanowires using the same method. Although this method has been successful in producing cadmium selenide (CdSe) nanodots, nanorods and tetrapods, it remains a challenge to obtain nanowires. After systematically varying the parameters, we were able to gain some understanding in the growth of anisotropic nanocrystals. CdSe nanowires with a length of 220 nm and a diameter of 8 nm were successfully synthesized.DOCTOR OF PHILOSOPHY (MSE

Predicting Flight Trajectory in Convective Weather through Boosted Spatiotemporal Deep Learning Ensemble

Flight trajectory prediction is one of the key issues in ensuring the safety of air traffic, providing the air traffic controller with the foresight of flight conflicts so that control instructions for pilots can be preconceived. In a complicated mechanism, flight trajectories can be severely affected by convective weather, making accurately predicting trajectories challenging. To address this problem, we propose a boosted spatiotemporal deep learning ensemble for mining the law of how convective weather affects flight trajectory stretching. Instead of conventionally representing trajectory data in a geographic coordinate system, we design a relative coordinate system for gaining new trajectory features which tangibly reflect trajectory’s relations with planned route and convective weather. Besides, we raise a boosted ensemble framework of spatiotemporal deep learning models, trained by the samples pairing sequential trajectory with graphical weather, dedicating to strengthen the mining of the high-value training samples that involve explicit flight deviations caused by convective weather. The experiments using actual flight and weather data demonstrate our method’s superiority in predicting flight trajectory affected by convective weather

High-pressure experimental verification of rutile-ilmenite oxybarometer: Implications for the redox state of the subduction zone

The more oxidized mantle peridotites above subducting slabs than stable continental areas have been attributed to the infiltration of some oxidizing fluids released from the subducting slabs. However, knowledge for the redox states of the slabs itself is very limited. Until now, few oxybarometers can be directly used to constrain the redox states of the subducting slabs. The rutile-ilmenite oxybarometer was proposed and successfully applied to constrain the oxygen fugacity of mantle assemblages. However, its application to rocks equilibrated at crustal P-T conditions has been hampered by some uncertainties in an early solid solution model of ilmenite. With a newly-released solid solution model for the ilmenite, we have conducted high-P experiments (at 3 and 5 GPa, and 900–1300°C) to test the accuracy of this oxybarometer. The experiments were performed with their oxygen fugacities controlled by the CCO buffer (i.e., C+O2=CO2). We demonstrated that the oxygen fugacities calculated for our high-P experimental products by using the rutile-ilmenite oxybarometer were in excellent agreement with the fO2 dictated by the CCO buffer, suggesting a wide applicability of this oxybarometer to crust rocks. As examples, the rutile-ilmenite oxybarometer has been used to constrain the oxygen fugacities of some metamorphic rocks such as eclogite, granulite and amphibolite usually observed from the subduction zone

Equation of State of a Natural Chromian Spinel at Ambient Temperature

A natural chromian spinel with the composition (Mg0.48(3)Fe0.52(3))(Fe0.06(1)Al0.28(1)Cr0.66(2))2O4 was investigated up to 15 GPa via synchrotron X-ray diffraction with a diamond-anvil cell at room temperature. No phase transition was clearly observed up to the maximum experimental pressure. The pressure⁻volume data fitted to the third-order Birch⁻Murnaghan equation of state yielded an isothermal bulk modulus ( K T 0 ) of 207(5) GPa and its first pressure derivative ( K T 0 ′ ) of 3.2(7), or K T 0 = 202(2) GPa with K T 0 ′ fixed as 4. With this new experimental result and the results on some natural chromian spinels in the literature, a simple algorithm describing the relation between the K T 0 and the compositions of the natural chromian spinels was proposed. To examine this algorithm further, more compression experiments should be performed on natural chromian spinels with different chemical compositions