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Titanium dioxide (TiO2) is a promising electrode material for reversible lithium storage. However, the poor electronic conductivity, sluggish diffusivity, and intrinsic kinetics limit hinder its fast lithium storage capability. Here we present that the oxygen‐deficient TiO2 hierarchical spheres can address the issues for high capacity, long‐term lithium‐ion battery anode. First‐principles calculations show that introducing oxygen vacancies to anatase TiO2 can reduce the bandgap, thus improving the electronic conductivity and further the lithium storage properties of TiO2. By annealing TiO2/H2Ti5O11⋅3H2O hierarchical spheres precursor in nitrogen, accompanying with the phase transfer process, the growth of TiO2 crystallites is restricted due to the generation of residual carbon species, resulting in a well maintained hierarchical spherical structure. Rich oxygen vacancies are generated in the oxygen‐deficient environment and evidenced by EPR, XPS, and UV‐Vis spectra, which enable the TiO2 hierarchical spheres reduced bandgap. The oxygen vacancies in the as‐obtained TiO2 hierarchical spheres together with the high structural integrity of the hierarchical spheres gives rise to superior lithium storage properties including a high specific capacity of 282 mAh g−1 at 200 mA g−1, and long‐term cycling stability with a capacity retention of 85.2 % at 4 A g−1 over 10000 cycles. [ABSTRACT FROM AUTHOR]

Understanding the multiple phase transitions such as collapse transition, phase separation, and crystallization in solutions is of fundamental importance to control the solution structure of conjugated polymers in device processing. Combining in situ synchrotron radiation small and wide‐angle X‐ray scattering, ultrasensitive differential scanning calorimetry, ultraviolet–visible absorption spectroscopy, and polarized optical microscopy, we investigate the order–disorder transitions in poly(3‐hexylthiophene)/toluene solutions during cooling and heating processes. We demonstrate the occurrence of collapse transition of polymer chains from a random coil state to a lower dimensional network prior to the onset of crystallization during cooling in solution. This conformational preordering can lead to the formation of a lyotropic liquid crystalline phase, which is of great significance to the crystallization and ordering in polymer films, and further to promote its electric performance. It is examined that the mobility of films cast from chain‐collapsed solutions can be one order of magnitude higher than that from isotropic solutions with random‐coiled conformations. Thus, the conformational preordering in solutions is proposed to be a more efficient way than the postannealing of films to improve the electric performance of conjugated polymer films. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1105–1114 [ABSTRACT FROM AUTHOR]

Two new oxovanadium(V) complexes, [VOL(mat)] (1) and [VOL(Et‐mat)] (2) (mat = maltolate, Et‐mat = ethyl maltolate), where L is the dianionic form of N′‐(3‐ethoxy‐2‐hydroxybenzylidene)‐3‐hydroxy‐4‐methoxybenzohydrazide (H2L), were prepared and characterized by elemental analysis, IR, UV/Vis, and 1H NMR spectra. The structures of the compounds were further confirmed by single‐crystal X‐ray diffraction. The hydrazone ligand coordinates to the V atoms through the phenolate oxygen, imino nitrogen, and enolate oxygen. The maltolate and ethyl maltolate ligands coordinated to the V atoms through the carbonyl oxygen and deprotonated hydroxyl oxygen. The V atom in each complex is in octahedral coordination. The complexes were administered intragastrically to both normal and alloxan‐diabetic mice for two weeks. The biological activity results show that the complexes at doses of 10.0 and 20.0 mg V·kg–1, can significantly decrease the blood glucose level in alloxan‐diabetic mice, but the blood glucose level in the treated normal mice was not altered. [ABSTRACT FROM AUTHOR]

ABSTRACT The effect of different functional groups of methylated urea on the phase transition of poly( N-isopropylacrylamide) (PNIPAM) aqueous solutions has been studied by a high-sensitivity differential scanning calorimetry. The results reveal that with the addition of osmolytes with NH groups, the enthalpy change increases with the number of DSC cycles, presumably due to the gradual formation of hydrogen bonds with dehydrated CO groups of PNIPAM at high temperature. Moreover, with the addition of tetramethylurea (TMU) without hydrogen bond donor groups, the enthalpy change of PNIPAM solution remains unchanged with the number of DSC cycles and decreases with the TMU concentration, suggesting that the van der Waals interactions between TMU and isopropyl groups of PNIPAM and the weakening of hydrophobic interactions between isopropyl groups play a dominant role in the effect of TMU on the phase transition of PNIPAM. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1145-1151 [ABSTRACT FROM AUTHOR]

Human upstream binding factor (hUBF) HMG Box-5 is a highly conserved protein domain, containing 84 amino acids and belonging to the family of the nonspecific DNA-binding HMG boxes. Its native structure adopts a twisted L shape, which consists of three α-helices and two hydrophobic cores: the major wing and the minor wing. In this article, we report a reversible three-state thermal unfolding equilibrium of hUBF HMG Box-5, which is investigated by differential scanning calorimetry (DSC), circular dichroism spectroscopy, fluorescence spectroscopy, and NMR spectroscopy. DSC data show that Box-5 unfolds reversibly in two separate stages. Spectroscopic analyses suggest that different structural elements exhibit noncooperative transitions during the unfolding process and that the major form of the Box-5 thermal intermediate ensemble at 55°C shows partially unfolded characteristics. Compared with previous thermal stability studies of other boxes, it appears that Box-5 possesses a more stable major wing and two well separated subdomains. NMR chemical shift index and sequential 1HN i-1HN i+1 NOE analyses indicate that helices 1 and 2 are native-like in the thermal intermediate ensemble, while helix 3 is partially unfolded. Detailed NMR relaxation dynamics are compared between the native state and the intermediate ensemble. Our results implicate a fluid helix-turn-helix folding model of Box-5, where helices 1 and 2 potentially form the helix 1-turn-helix 2 motif in the intermediate, while helix 3 is consolidated only as two hydrophobic cores form to stabilize the native structure. Proteins 2009. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]