Novel melatonin-trientine conjugate as potential therapeutic agents for Alzheimer's disease.

Researchers continue to explore drug targets to treat the characteristic pathologies of Alzheimer's disease (AD). Some drugs relieve the pathological processes of AD to some extent, but the failed clinical trials indicate that multifunctional agents seem more likely to achieve the therapy goals for this neurodegenerative disease. Herein, a novel compound named melatonin-trientine (TM) has been covalently synthesized with the natural antioxidant compounds melatonin and the metal ion chelator trientine.

Author Correction: Universal mechanical exfoliation of large-area 2D crystals.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Universal mechanical exfoliation of large-area 2D crystals.

Two-dimensional materials provide extraordinary opportunities for exploring phenomena arising in atomically thin crystals. Beginning with the first isolation of graphene, mechanical exfoliation has been a key to provide high-quality two-dimensional materials, but despite improvements it is still limited in yield, lateral size and contamination. Here we introduce a contamination-free, one-step and universal Au-assisted mechanical exfoliation method and demonstrate its effectiveness by isolating 40 types of single-crystalline monolayers, including elemental two-dimensional crystals, metal-dichalcogenides, magnets and superconductors.

Enantioselective [2 + 2] cycloaddition of -allenamides with cyclic -sulfonylketimines: access to polysubstituted azetidines bearing quaternary stereocenters.

A Ni(ClO)-catalyzed enantioselective [2 + 2] cycloaddition of -allenamides with cyclic -sulfonylketimines was developed, which regioselectively occurred at the proximal C[double bond, length as m-dash]C bonds of the -allenamides. Broad substrate scope of -allenamides and cyclic -sulfonylketimines was observed. A range of fused polysubstituted azetidines bearing quaternary stereocenters were afforded in good yields and with excellent enantioselectivities (up to 99%).

Enantioselective alkynylation of N-sulfonyl α-ketiminoesters via a Friedel-Crafts alkylation strategy.

Enantioselective alkynylation of cyclic N-sulfonyl α-ketiminoesters with terminal alkynes was developed by using an Ni(ClO)/(R)-DTBM-Segphos complex as a catalyst. A range of propargylic amides bearing quaternary stereocenters were afforded in excellent enantioselectivities (up to 97% ee). Theoretical studies revealed that this reaction proceeded via a Friedel-Crafts-type reaction pathway.

FeTeSe monolayer films: towards the realization of high-temperature connate topological superconductivity.

We performed angle-resolved photoemission spectroscopy studies on a series of FeTeSe monolayer films grown on SrTiO. The superconductivity of the films is robust and rather insensitive to the variations of the band position and effective mass caused by the substitution of Se by Te. However, the band gap between the electron- and hole-like bands at the Brillouin zone center decreases towards band inversion and parity exchange, which drive the system to a nontrivial topological state predicted by theoretical calculations.

Astragaloside IV, a Natural PPARγ Agonist, Reduces Aβ Production in Alzheimer's Disease Through Inhibition of BACE1.

A number of epidemiological studies have established a link between Alzheimer's disease (AD) and diabetes mellitus (DM). So, nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) plays an important role in the treatment of AD. However, current PPARγ-targeting drugs such as thiazolidinediones (TZDs) are associated with undesirable side effects.

Insulin inhibits Abeta production through modulation of APP processing in a cellular model of Alzheimer's disease.

Objective: Amyloid-beta (Abeta) is a 36-43 amino acid peptide that is derived by processing of the beta-amyloid precursor protein (APP). Abeta plays a central role in the development of Alzheimer's disease (AD). Although growing evidence suggests that insulin has important functions in Abeta metabolism, the underlying mechanisms are still unknown.

Streptozotocin-induced diabetes increases amyloid plaque deposition in AD transgenic mice through modulating AGEs/RAGE/NF-κB pathway.

Background: An increasing number of studies have demonstrated of that diabetes mellitus (DM) is associated with an increased prevalence of Alzheimer disease (AD), the underlying mechanisms are still obscure.

Methods: We developed a streptozotocin (STZ)-induced diabetic AD transgenic mouse model and evaluated the effect of hyperglycemia on senile plaque formation.

Results: Our data showed that administration of STZ increased the level of blood glucose and increased the advanced glycation end products (AGEs) in brain tissue, and further enhanced the expression levels of the receptor for AGEs (RAGE) and the nuclear factor-kappa B (NF-κB) in the brain, and accelerated the senile plaque formation in the transgenic mice.

KFe2Se2 is the parent compound of K-doped iron selenide superconductors.

We elucidate the existing controversies in the newly discovered K-doped iron selenide (K(x)Fe(2-y)Se(2-z)) superconductors. The stoichiometric KFe(2)Se(2) with √2 × √2 charge ordering was identified as the parent compound of K(x)Fe(2-y)Se(2-z) superconductor using scanning tunneling microscopy and spectroscopy. The superconductivity is induced in KFe(2)Se(2) by either Se vacancies or interacting with the antiferromagnetic K(2)Fe(4)Se(5) compound.

Valproate reduces tau phosphorylation via cyclin-dependent kinase 5 and glycogen synthase kinase 3 signaling pathways.

Valproate (VPA) is a widely used anticonvulsant and mood-stabilizing drug. Recent studies have shown that VPA could reduce amyloid-β generation, and improve memory deficits in transgenic mouse models of Alzheimer's disease (AD). However, whether VPA affects tau phosphorylation and the underlying mechanism has not been established.

Exact SO(5) symmetry in the spin-3/2 fermionic system.

The spin-3/2 fermion models with contact interactions have a generic SO5 symmetry without any fine-tuning of parameters. Its physical consequences are discussed in both the continuum and lattice models. A Monte Carlo algorithm free of the sign problem at any doping and lattice topology is designed when the singlet and quintet interactions satisfy U0< or = U2< or = -3/5 U0 (U0< or = 0), thus making it possible to study different competing orders with high numerical accuracy.

Antiferromagnetism and hole pair checkerboard in the vortex state of high T(c) superconductors.

We propose a microscopic state for the vortex phase of BSCO superconductors. Around the vortex core or above H(c2), the d wave hole pairs form a checkerboard localized in the antiferromagnetic background. We discuss this theory in connection with recent STM experiments.