The aggregation behavior of three long-chain N-aryl imidazolium ionic liquids (ILs), 1-(2,4,6-trimethylphenyl)-3-alkylimidazolium bromide [C(n)pim]Br (n = 10, 12, and 14), in aqueous solutions was systematically explored by surface tension, electrical conductivity, and (1)H NMR. A lower critical micelle concentration (cmc) for the N-aryl imidazolium ILs is observed compared with that for 1,3-dialkylimidazolium ILs [C(n)mim]Br, indicating that the incorporation of the 2,4,6-trimethylphenyl group into a headgroup favors micellization. The enhanced π-π interactions among the adjacent 2,4,6-trimethylphenyl groups weaken the steric hindrance of headgroups and thus lead to a dense arrangement of [C(n)pim]Br molecules at the air-water interface. An analysis of the (1)H NMR spectra revealed that the introduced 2,4,6-trimethylphenyl group may slightly bend into the hydrophobic regions upon micellization. The micelle formation process for [C(n)pim]Br (n = 10, 12, and 14) was found to be enthalpy-driven in the investigated temperature range, which is attributed to the strong electrostatic self-repulsion of the headgroups and the counterions as well as the π-π interactions among headgroups. Strong, stable fluorescence properties are presented by the new N-aryl imidazolium ILs, indicating their potential application in the field of photochemistry.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, accompanied by memory loss and cognitive impairments, and there is no effective treatment for it at present. Since type 2 diabetes (T2DM) has been identified as a risk factor for AD, the incretins glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP), promising antidiabetic agents for the treatment of type 2 diabetes, have been tested in models of neurodegenerative disease including AD and achieved good results. Here we show for the first time the potential neuroprotective effect of a novel dual GLP-1/GIP receptor agonist (DA-JC4) in the icv. streptozotocin (STZ)-induced AD rat model. Treatment with DA-JC4 (10nmol/kg ip.) once-daily for 14days after STZ intracerebroventricular (ICV) administration significantly prevented spatial learning deficits in a Y- maze test and Morris water maze tests, and decreased phosphorylated tau levels in the rat cerebral cortex and hippocampus. DA-JC4 also alleviated the chronic inflammation response in the brain (GFAP-positive astrocytes, IBA1-positive microglia). Apoptosis was reduced as shown in the reduced ratio of pro-apoptotic BAX to anti- apoptotic Bcl-2 levels. Importantly, insulin signaling was re-sensitized as evidenced by a reduction of phospho-IRS1 levels and phospho-Akt up-regulation. In conclusion, the novel dual agonist DA-JC4 shows promise as a novel treatment for sporadic AD, and reactivating insulin signaling pathways may be a key mechanism that prevents disease progression in AD.

Dynamic rheological measurements indicate that supra-molecules, polymers and carbogenic nanoparticles are generated successively during pyrolysis of citric acid based nanodots.

In this work, a simple and label-free electrochemical biosensor is developed for microRNA (miRNA) detection on the basis of an arched probe mediated isothermal exponential amplification reaction (EXPAR). The arched probe assembled on the electrode surface consists of two strands that are partially complementary to each other at both ends. The target can hybridize with the complementary sequence of the arched structure, leading to the cleavage of the probe. The strand fixed on the surface of the electrode self-assembles, in the presence of hemin, to G-quadruplex unit, yielding electrochemical signals. The other strand liberated into the solution triggers the EXPAR to recycle and regenerate targets. This method exhibits ultrahigh sensitivity toward miRNA with detection limits of 5.36 fM and a detection range of 3 orders of magnitude. The biosensor is capable of discriminating a single-nucleotide difference between concomitant miRNA and performs well in analyzing crude extractions from cancer cell lines.

The aggregation behavior of surface active imidazolium ionic liquids (ILs) with different alkyl chain length, cations, and counterions, namely, 1-alkyl-3-methylimidazolium bromide ([C(n)mim]Br (n = 8, 10, 12)), 1-dodecyl-2,3-dimethylimidazolium bromide ([C(12)bmim]Br), 1-(2,4,6-trimethylphenyl)-3-dodecylimidazolium bromide ([C(12)pim]Br), and 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C(12)mim][BF(4)]) in a protic room temperature IL, ethylammonium nitrate (EAN), was investigated through surface tension measurements and (1)H NMR spectroscopy. Surface tension results show that surface properties and micellization behavior of surface active ILs in EAN are significantly affected by the structure of the cations, the basicity of counterions, and the hydrophobicity of alkyl chains. A detailed analysis of chemical shifts of various protons of surface active ILs and EAN was employed to investigate the micelle formation mechanism. Hydrogen bonding interaction is found to occur between the protons at C-2 on the imidazolium ring and the oxygen atoms in [NO(3)](-) anions, and the interaction varies as a function of the basicity of the counterions and the hydrophobicity of the side-chains bonded to the imidizolium ring. The micelle formation may be accompanied by a partial changeover from trans to gauche conformations in the alkyl chain. The solvophobic effect may exist between the hydrophobic portion of [CH(3)CH(2)NH(3)](+) and the hydrophobic chains of the surface active ILs.