国产一区二区制服丝袜_一级特黄高清完整大片_欧美.亚洲.日韩.另类.av_黄又色又污又爽又高潮动态图_91夫妻视频电影观看_在线手机亚洲中文字幕_国产中文字幕不卡在线_国产乱妇乱子在线播视频播放网站_gogo裸体艺术中国日本

Complexation of trans -resveratrol with β-cyclodextrin results in an induced Cotton effect (ICD). On the basis of NMR T-ROESY experiments and molecular dynamics simulations a preferential orientation mode of resveratrol within the cyclodextrin is proposed, in which the dihydroxyl ring is oriented towards the narrow side of the β-cyclodextrin. TD-DFT calculations showed that the observed ICD is caused by orbital mixing on trans -resveratrol upon complexation with β-cyclodextrin, being geometry effects averaged out by the flexibility of resveratrol inside the CD cavity. Computations also show that Harata–Kodaka rules are not of direct applicability to systems like resveratrol where the chromophore is only partially buried into the cyclodextrin cavity.

The passivation and charge compensation provided by inorganic halide ligands on low index facets of lead selenide (PbSe) nanocrystals has been studied using density functional theory to produce projected densities of states (PDOS), bond lengths and to perform Bader analysis. The calculations were made using a grid-based planar augmented wave code with a localized double zeta potential basis and the generalized gradient approximation. Surface energies of halide ligands bonded onto surface Pb atoms show trends that are consistent with the increased electronegativity of the species, with iodine having the lowest binding energy of the halides investigated. Different densities of iodine ligands lead to different levels of passivation with a continuous widening of the bandgap on particular facets for increasing levels of coverage. In particular, the (111) plane shows a clear recovery of surface layer back to bulk property and widening of bandgap when the ligands cover most Pb atoms on the surfaces. Additionally, a possible increase of carrier conductance along with the increase of ligand density has been found using Bader analysis. Relative increases in the conductance for large halide atoms stem from the measurable increases to electronic states near the top of the valence band in these p-type semiconductors. The passivation is observed to increase along with the s-type character of the electron density at the surface, suggesting that a higher degree of symmetry in the electron density accompanies the reduction in defect levels.

Dentinal hypersensitivity is an acute transient pain caused by the exposition of the dentinal tubules. The exposed tubules not only cause hypersensitivity but also cause the yellow coloration of the teeth due to their dominance in teeth coloration. An occlusion of the open dentinal tubules by the in situ biomineralization of hydroxyapatite (HAp) is so far the most effective method to alleviate the dentinal hypersensitivity. In recent years, several remineralization strategies, employing various substrates, have been studied for the treatment of dentinal hypersensitivity. However, aesthetically ideal solutions that include the tooth whitening aspect are poorly studied alongside with the tubular occlusion. Herein, the aesthetical improvement along with significant bioremineralization of the HAp crystals for the treatment of dentinal hypersensitivity was examined after a tannin (TA)–metal (ions and oxides) chelates mediated mineralization. Thus, demineralized human molar disks were treated with tannin-based chelates (TA–M). Briefly, TA–M denotes TA combined with 5 different daily intake metal ions and metal oxides, such as Sr(NO 3 ) 2 , Fe 2 O 3 , TiO 2 , CaCl 2 , VCl 3 , and a non-metal oxide SiO 2 in separate experiments. The samples were coated in the TA–M solution for 4 min followed by immersion in an artificial saliva for 7 days. Biomineralized HAp crystals were well-characterized by various analytical techniques. Among these, TA–Sr(NO 3 ) 2 and TA–TiO 2 exhibited the most promising results, as they occluded ca. 79% and 68% of the dentinal tubules, respectively, with brighter color changes after the treatment. This desensitizing solution camouflaged the exposed dentin by its whitening effect using biocompatible Sr and Ti oxides, which may be potential for developing facile ‘at-home’ aesthetically effective dental desensitizer solution.

Ag 3 PW 12 O 40 /C 3 N 4 nanocomposites were successfully synthesized by loading Ag 3 PW 12 O 40 into C 3 N 4 , in which case Ag 3 PW 12 O 40 is gained through reaction between AgNO 3 and H 3 PW 12 O 40 at room temperature. The obtained nanocomposites show efficient and light-operated catalytic activity for hydrocarbon selective oxidation (selective oxidation of cyclooctene and cyclohexane) without adding any oxidant at 60 °C. For cyclooctene, the conversion based on cyclooctene is 41.26%, and the selectivity of selective oxidation to epoxycyclooctane can be up to 77.2%. The nanocomposite catalyst yielded oxidation of cyclohexane to cyclohexanone with 8.62% efficiency and 99.0% selectivity. In the catalytic system, the oxidant (H 2 O 2 ) in the catalysis process can be produced by the irradiation of C 3 N 4 and then decomposed into HO· with the help of Ag 3 PW 12 O 40 . The observed improvement in the activities of photo-induced oxidation of cyclooctene and cyclohexane is mainly attributed to the high BET surface area of C 3 N 4 . With the synergistic effect of Ag 3 PW 12 O 40 and C 3 N 4 , the nanocomposite displays considerable catalytic activity, which sheds light on the catalyst design applied in the selective oxidation of hydrocarbon.

Giant unilamellar vesicles (GUVs) with phase coexistence allow for the recovery of inter-domain partition coefficients ( K p ) of fluorescent molecules through comparison of fluorescence intensities in each phase. This method has been extensively used to gather qualitative information regarding the preference of both lipid analogues and other fluorescent molecules for insertion into ordered lipid membrane phases, which is often used as a predictor for incorporation in ordered plasma membrane domains. Methods aiming to recover quantitative information on partition properties from GUV imaging fail to correct for brightness and area per lipid differences, skewing recovered values. Additionally, photoselection effects occurring in the presence of linearly polarized excitation are generally neglected in these calculations. Here, we describe a new methodology for correction of fluorescence imaging data obtained from GUVs to recover accurate partition coefficients, which accounts for changes in the probe's quantum yield, area per lipid differences and photoselection effects. This general methodology is used to quantify liquid ordered/liquid disordered lipid phase partition coefficients of several commonly used fluorescent analogues of phospholipids. Importantly, several sources of error in spectroscopic measurements of K p , such as incorporation of a fluorescent probe in domain boundaries, clustering in water or in the membrane, or formation of three coexisting phases, are either irrelevant for quantification of inter-domain K p 's through the method presented here or are readily recognized through imaging with GUVs.

We have synthesized rhodol hydrazide (RDH) as a simple fluorescent probe for detecting Hg 2+ . The probe can be applied in nontoxic solvents (EtOH and H 2 O). The probe has high selectivity and sensitivity to Hg 2+ at pH 6–8. In addition, the probe has a superior capacity to resist interference from other ions. Both fluorescence intensity and absorbance have a linear relationship with the concentration of Hg 2+ , which ensured the precise detection of Hg 2+ . Furthermore, we have studied the intracellular Hg 2+ imaging behavior of the probe on mammalian cells, which indicated that the probe can be applied to monitor Hg 2+ within biological samples, especially in mammalian cells.

We report a simple and green process to prepare poly(vinyl alcohol)/carbon nanotube (PVA/CNT) composite fibers having high mechanical properties. This process, an environmentally friendly one with no use of acid or hazardous solvent, produces the composite fibers utilizing a PVA layer pre-coated on a PET film. SEM micrographs indicated that the CNTs are well dispersed in the PVA matrix, and the diameter of the fiber is around 50 μm. Mechanical properties of the composite fiber treated at different thermal annealing conditions are also reported.

Boron containing silicon-based ceramics with enhanced high-temperature stability have attracted great attention. An ultrafine and flexible silicon boron oxycarbide (SiBOC) fiber mat fabricated by electrospinning with a sol–gel system and subsequent pyrolysis is reported. The formation, composition and structure of the SiBOC fibers were studied by FT-IR, XRD, TG-MS, FE-SEM, HRTEM, XPS and MAS NMR. In comparison with the SiOC fibers, the SiBOC fibers showed better high-temperature stability. After being heated at 800 °C in air for 1 h, or immersed in 2 M NaOH and 1 M H 2 SO 4 solutions for 24 h, the SiBOC fibers remained intact without of any detectable change. The SiBOC fibers illustrated superior amphiphilic affinity to water and xylene. Such a flexible SiBOC fiber mat may be of interest as a high-temperature catalyst support, LIB anode, capacitor, and so on.

The phase stabilities, elastic anisotropies, and thermal conductivities of ReB 2 diborides under ambient conditions have been investigated by using density functional theory calculations. It was found that P 6 3 / mmc (hP6-ReB 2 ), Pmmn (oP6-ReB 2 ), R m (hR3-ReB 2 ), R m (hR6-ReB 2 ), and C 2/ m (mC12-ReB 2 ) of ReB 2 are both mechanically and dynamically stable, and the order of phase stability is hP6 oP6 hR3 hR6 mC12. Moreover, the calculated Vickers hardness showed that hP6-ReB 2 , oP6-ReB 2 , hR3-ReB 2 , and mC12-ReB 2 were potential hard materials, while hR6-ReB 2 could not be used as a candidate hard material. In addition, the elastic-dependent anisotropy properties of ReB 2 in different crystal structures were also investigated. The results show that the anisotropic order of the Young's modulus and shear modulus of ReB 2 is hR6 mC12 oP6 hP6 hR3, while that of the bulk modulus is mC12 hR3 hP6 oP6 hR6. Finally, by means of Clarke's and Cahill's models, the minimum thermal conductivities of ReB 2 in different crystal structures were further evaluated, and the order of them is hR3 hP6 mC12 oP6 hR6. Moreover, the results show that all these ReB 2 diborides exhibit relatively low thermal conductivities and are suitable for thermal insulation materials.

Herein we report an abnormal adsorption and desorption behavior where a stronger adsorption interaction between polystyrene particles and pharmaceutical drugs results in preferable desorption behavior. This behavior is contrary to the conventional view, in which a weaker adsorption interaction would lead to a more favorable desorption behavior of target molecules at solid surfaces. Different from other materials, numerous experimental results from a combination of mass spectrometry and infrared spectroscopy indicated quantitatively that the adsorption and desorption behavior of pharmaceutical drugs on polystyrene were independent of drug structure and solvent, while the intermolecular hydrogen bond interaction between polystyrene and the drug played a critical role in determining the adsorption and desorption behavior.