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CpG methylation of DNA is common in mammalian cells. In sperm, the DNA has the highest level of CpG methylation and is condensed into toroidal structures. How CpG methylation affects DNA structures and interactions is important to understand its biological roles but is largely unknown. Using an RNA-DNA-RNA structure, we observed the equilibrium hopping dynamics between the condensed and extended states of DNA in the presence of polyamines or polylysine peptide as a reduced model of histone tails. Combing with the measured DNA elasticities, we report that CpG methylation of each cytosine nucleotide substantially increases DNA-DNA attraction by up to 0.2 kBT. For the DNA with 57% GC content, the relative increase caused by CpG methylation is up to 32% for the spermine-induced DNA-DNA attraction and up to 9% for the polylysine-induced DNA-DNA attraction. These findings help us to evaluate the energetic contributions of CpG methylation in sperm development and chromatin regulation.

Owing to its excellent physical and chemical properties, ZnO has been considered to be a promising material for development of NO2 sensors with high sensitivity, and fast response and recovery. However, due to the low activity of ZnO at low temperature, most of the current work is focused on detecting NO2 at high operating temperatures (200–500 °C), which will inevitably increase energy consumption and shorten the lifetime of sensors. In order to overcome these problems and improve the practicality of ZnO-based NO2 sensors, it is necessary to systematically understand the effective strategies and mechanisms of low-temperature NO2 detection of ZnO sensors. This paper reviews the latest research progress of low-temperature ZnO nanomaterial-based NO2 gas sensors. Several efficient strategies to achieve low-temperature NO2 detection (such as morphology modification, noble metal decoration, additive doping, heterostructure sensitization, two-dimensional material composites, and light activation) and corresponding sensing mechanisms (such as depletion layer theory, grain boundary barrier theory, spill-over effects) are also introduced. Finally, the challenges and future development directions of low-temperature ZnO-based NO2 sensors are outlined.

A new coordination polymer (CP), namely poly[(μ-4,4′-bipyridine)(μ3-3,4′-oxydibenzoato)cobalt(II)], [Co(C14H8O5)(C10H8N2)] n or [Co(3,4′-obb)(4,4′-bipy)] n (1), was prepared by the self-assembly of Co(NO3)2·6H2O with the rarely used 3,4′-oxydibenzoic acid (3,4′-obbH2) ligand and 4,4′-bipyridine (4,4′-bipy) under solvothermal conditions, and has been structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography and powder X-ray diffraction (PXRD). Single-crystal X-ray diffraction reveals that each CoII ion is six-coordinated by four O atoms from three 3,4′-obb2− ligands, of which two function as monodentate ligands and the other as a bidentate ligand, and by two N atoms from bridging 4,4′-bipy ligands, thereby forming a distorted octahedral CoN2O4 coordination geometry. Adjacent crystallographically equivalent CoII ions are bridged by the O atoms of 3,4′-obb2− ligands, affording an eight-membered Co2O4C2 ring which is further extended into a two-dimensional [Co(3,4′-obb)] n sheet along the ab plane via 3,4′-obb2− functioning as a bidentate bridging ligand. The planes are interlinked into a three-dimensional [Co(3,4′-obb)(4,4′-bipy)] n network by 4,4′-bipy ligands acting as pillars along the c axis. Magnetic investigations on CP 1 disclose an antiferromagnetic coupling within the dimeric Co2 unit and a metamagnetic behaviour at low temperature resulting from intermolecular π–π interactions between the parallel 4,4′-bipy ligands.

In this study, the 2D porous graphitic carbon nitride (g-C₃N₄) nanosheets were successfully fabricated via a facile thermal decomposition polymerization method without any help of templates, and then novel porous g-C₃N₄/CdS complex catalysts of different mass fractions were is situ synthesized by a simple solvothermal process. The results of photocatalytic experiments demonstrate that the coupling g-C₃N₄/CdS cocatalysts exhibit significant enhanced visible-light-driven photocatalytic activity for the decolorization of methyl orange (MO) compared with individual porous g-C₃N₄ and CdS. In particular, an optimal porous g-C₃N₄ content in the hybridized composite has been determined to be 70 wt.%, corresponding to pseudo-first-order rate constant of 0.046 min

In the present study, high-quality apatite-type La9.33Ge6O26 powders are successfully synthesized by a facile molten-salt synthesis method (MSSM) at low temperatures, using LiCl, LiCl/NaCl mixture (mass ratio 1:1) as molten salt, respectively. Experimental results indicate that the optimal mass ratio between reactant and molten salt is 1:2, and LiCl/NaCl mixed molten-salt is more beneficial for forming high-quality La9.33Ge6O26 powders than LiCl individual molten-salt. Comparing with the conventional solid-state reaction method (SSRM), the synthesis temperature of apatite-type La9.33Ge6O26 powders using the MSSM decreases more than 350 °C, which can effectively avoid Ge loss in the preparation process of precursor powders. Furthermore, the powders obtained by the MSSM are homogeneous, non-agglomerated and well crystallized, which are very favorable for gaining dense pellets in the premise of avoiding Ge loss. On the basis of high-quality precursor powders, the dense and pure ceramic pellets of La9.33Ge6O26 are gained at a low temperature of 1100 °C for 2 h, which exhibit higher conductivities (, and lower activation energies (, ) than that synthesized by the SSRM.