Synthesis of 2,7-Dihydrooxepine-spirodithiophene Derivatives via an Intramolecular Ring Closure Reaction.

Spiro architectures with π-conjugation have improved thermal stability and stronger photosensitivity, making them potentially useful for organic optoelectronic devices. Our recent work has demonstrated the synthetic chemistry of a novel thiophene oligomer combining 2,7-dihydrooxepine and dispiro structure and derived it into A-D-A-type compounds. The optical spectroscopy and electrochemical characteristics were investigated.

Structural and Functional Insights into Dishevelled-Mediated Wnt Signaling.

Dishevelled (DVL) proteins precisely control Wnt signaling pathways with many effectors. While substantial research has advanced our understanding of DVL's role in Wnt pathways, key questions regarding its regulatory mechanisms and interactions remain unresolved. Herein, we present the recent advances and perspectives on how DVL regulates signaling.

Exploring DIX-DIX Homo- and Hetero-Oligomers in Wnt Signaling with AlphaFold2.

Wnt signaling is involved in embryo development and cancer. The binding between the DIX domains of Axin1/2, Dishevelled1/2/3, and Coiled-coil-DIX1 is essential for Wnt/β-catenin signaling. Structural and biological studies have revealed that DIX domains are polymerized through head-to-tail interface interactions, which are indispensable for activating β-catenin Wnt signaling.

Overview of AlphaFold2 and breakthroughs in overcoming its limitations.

Predicting three-dimensional (3D) protein structures has been challenging for decades. The emergence of AlphaFold2 (AF2), a deep learning-based machine learning method developed by DeepMind, became a game changer in the protein folding community. AF2 can predict a protein's three-dimensional structure with high confidence based on its amino acid sequence.

Efficient Removal of Hexavalent Chromium (Cr(VI)) from Wastewater Using Amide-Modified Biochar.

The utilization of biochar, derived from agricultural waste, has garnered attention as a valuable material for enhancing soil properties and serving as a substitute adsorbent for the elimination of hazardous heavy metals and organic contaminants from wastewater. In the present investigation, amide-modified biochar was synthesized via low-temperature pyrolysis of rice husk and was harnessed for the removal of Cr(VI) from wastewater. The resultant biochar was treated with 1-[3-(trimethoxysilyl) propyl] urea to incorporate an amide group.

Kinetics of Catalytic Oxidation of Methylene Blue with La/Cu Co-Doped in Attapulgite.

Methylene blue (MB) is a common pollutant in wastewater from the printing and dyeing industries. In this study, attapulgite (ATP) was modified with La/Cu, using the method of equivolumetric impregnation. The La/Cu -ATP nanocomposites were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Ciprofloxacin removal by ultrasound-enhanced carbon nanotubes/permanganate process: In situ generation of free reactive manganese species via electron transfer.

Recently, free reactive manganese species (RMnS) generated via permanganate catalytic oxidation technology has been applied to contaminants abatement and sludge dewatering. This study proposed a novel free RMnS generation method in ultrasound enhanced carbon nanotube (CNTs)/permanganate process (UCP) for organics removal. Taking ciprofloxacin as a target contaminant, the removal efficiency in the UCP process (9.

Origin of the Regioselectivity in the Aldol Condensation between Hydroxymethylfurfural and Levulinic Acid: A DFT Investigation.

Our previous work demonstrated that hydroxide ion (OH) was able to catalyze aldol condensation reaction at room temperature between 5-hydroxymethylfurfural (HMF) and levulinic acid (LA). This work identified three primary reaction steps in this condensation reaction using density functional theory (DFT): (1) deprotonation of LA to generate LA ions, (2) LA ions addition at hydroxymethyl site of HMF, and (3) internal dehydration to form the condensation product. The reaction pathway through the C5 of LA forms a linear product that is favored with respect to both energy and configuration in all three elementary reaction steps.

Synthesis, crystal structure and investigation of mononuclear copper(II) and zinc(II) complexes of a new carboxylate rich tripodal ligand and their interaction with carbohydrates in alkaline aqueous solution.

A new carboxylate rich asymmetric tripodal ligand, N-[2-carboxybenzomethyl]-N-[carboxymethyl]-β-alanine (H3camb), and its di-copper(II), (NH4)2[1]2, and di-zinc(II), ((CH3)4N)2[2]2, complexes have been synthesized as carbohydrate binding models in aqueous solutions. The ligand and complexes have been fully characterized using several techniques, including single crystal X-ray diffraction. The interactions of (NH4)2[1]2 and ((CH3)4N)2[2]2 with D-glucose, D-mannose, D-xylose and xylitol in aqueous alkaline media were investigated using UV-Vis and (13)C-NMR spectroscopic techniques, respectively.

Molecular control of the nanoscale: effect of phosphine-chalcogenide reactivity on CdS-CdSe nanocrystal composition and morphology.

We demonstrate molecular control of nanoscale composition, alloying, and morphology (aspect ratio) in CdS-CdSe nanocrystal dots and rods by modulating the chemical reactivity of phosphine-chalcogenide precursors. Specific molecular precursors studied were sulfides and selenides of triphenylphosphite (TPP), diphenylpropylphosphine (DPP), tributylphosphine (TBP), trioctylphosphine (TOP), and hexaethylphosphorustriamide (HPT). Computational (DFT), NMR ((31)P and (77)Se), and high-temperature crossover studies unambiguously confirm a chemical bonding interaction between phosphorus and chalcogen atoms in all precursors.

Exocytosis of SH-SY5Y single cell with different shapes cultured on ITO micro-pore electrode.

Communication between cells by release of specific chemical messengers via exocytosis plays crucial roles in biological process. Catecholamines, like dopamine, epinephrine, and norepinephrine, which are types of neurotransmitters released from cells, can be oxidized and detected by the microelectrodes, and amperometric detection of exocytosis is an effective method for studying the communication between cells. The experimental results depend on many factors, among which the property of the microelectrode, cell states, and their positions to each other are particularly important.

[Determination of the eliminating ratio of TCM polysaccharide to hydroxyl radical by kinetic fluorescent spectrophotometry].

Objective: To explore reaction dynamic of hydroxyl radical (*OH) and salicylic acid,and to determine the elimination ratios of TCM polysaccharide to *OH by kinetic fluorescent analysis.

Methods: The impact dynamics factors of this reaction were studied by fluorescent, such as the reaction of concentration, reaction time and temperature. The dynamical equation was built, a kinetic fluorescent spectrophotometry based on the reaction was developed to determine the elimination ratio.

Density functional study of the catalytic cycle of nickel-iron [NiFe] hydrogenases and the involvement of high-spin nickel(II).

In light of recent experiments suggesting high-spin (HS) Ni(II) species in the catalytic cycle of [NiFe] hydrogenase, a series of models of the Ni(II) forms Ni-SI(I,II), SI-CO and Ni-R(I,II,III) were examined in their high-spin states via density functional calculations. Because of its importance in the catalytic cycle, the Ni-C form was also included in this study. Unlike the Ni(II) forms in previous studies, in which a low-spin (LS) state was assumed and a square-planar structure found, the optimized geometries of these HS Ni(II) forms resemble those observed in the crystal structures: a distorted tetrahedral to distorted pyramidal coordination for the NiS4.

[Determination of cadmium, chromium and lead in Lycoris radiata with microwave digestion technique by graphite furnace atomic absorption spectrometry].

A new method using microwave digestion technique was developed for the determination of cadmium, chromium and lead in Lycoris radiata by graphite furnace atomic absorption spectrometry (GFAAS). Digestion solvents were discussed for sample preparation by microwave digestion technique. The optimum condition of determination by GFAAS was studied in the presence of NH4H2PO4 matrix modifier.

IR spectroelectrochemical study of the binding of carbon monoxide to the active site of Desulfovibrio fructosovorans Ni-Fe hydrogenase.

The binding of carbon monoxide, a competitive inhibitor of many hydrogenases, to the active site of Desulfovibrio fructosovorans hydrogenase has been studied by infrared spectroscopy in a spectroelectrochemical cell. Direct evidence has been obtained of which redox states of the enzyme can bind extrinsic CO. Redox states A, B and SU do not bind extrinsic CO; only after reductive activation of the hydrogenase can CO bind to the active site.

High-spin Ni(II), a surprisingly good structural model for [NiFe] hydrogenase.

The first density functional calculations on high-spin (HS) Ni(II) models for the active site of the [NiFe] hydrogenases predict a ligand arrangement about Ni that is in better agreement with the crystal structures than previous predictions for low-spin (LS) Ni(II) models. With the crystal structures' geometry, the HS form is approximately 20 kcal/mol lower in energy than the LS one.