An ultralong room-temperature phosphorescent material based on the combination of small singlet-triplet splitting energy and H-aggregation.

Compound AI-N-Cz was conveniently synthesized, and it exhibited ultralong room-temperature phosphorescence (RTP) with a lifetime of 775 ms, which was more than 400 times the RTP lifetime of its isomer AI-Cz (1.9 ms). The ultralong RTP of AI-N-Cz might be due to the combination of small singlet-triplet splitting energy (ΔE) and H-aggregation, and this could be an efficient strategy for the further design of ultralong organic room-temperature materials.

Phthalimide-based "D-N-A" emitters with thermally activated delayed fluorescence and isomer-dependent room-temperature phosphorescence properties.

Phthalimide-based "D-N-A" emitters o-AI-Cz, m-AI-Cz and p-AI-Cz showed TADF and RTP properties due to their small ΔEST in both film and crystalline states. In particular, o-AI-Cz exhibited an ultralong RTP with a lifetime of 602 ms in air and remarkable afterglow, which could allow it to be used as a security ink for application in anti-counterfeiting materials. Moreover, o-AI-Cz showed intense intramolecular interaction between the donor and the acceptor subunits, while p-AI-Cz could form regular hexagonal pores with a diameter of 13.

A fast 3-D ultrasound projection imaging method for scoliosis assessment.

Applying ultrasound for scoliosis assessment has been an attractive topic over the past decade. This study proposed a new fast 3-D ultrasound projection imaging method to evaluate the spine deformity. A narrow-band rendering method was used to generate the coronal images based on B-mode images and their corresponding positional data.

Solvent-Controlled Synthesis of Highly Luminescent Carbon Dots with a Wide Color Gamut and Narrowed Emission Peak Widths.

Carbon dots (CDs) have tremendous potential applications in bioimaging, biomedicine, and optoelectronics. By far, it is still difficult to produce photoluminescence (PL) tunable CDs with high quantum yield (QY) across the entire visible spectrum and narrow the emission peak widths of CDs close to those of typical quantum dots. In this work, a series of CDs with tunable emission from 443 to 745 nm, quantum yield within 13-54%, and narrowed full width at half maximum (FWHM) from 108 to 55 nm, are obtained by only adjusting the reaction solvents in a one-pot solvothermal route.

Four 3D coordination polymers based on layers with single - carboxylate bridges: synthesis, structures, and magnetic properties.

Four novel coordination polymers (CPs) based on a new 4-(3,5-dicarboxylphenyl) picolinic acid ligands (HL), [M(L)(HO)]·4HO (M = Mn, 1; Co, 2; Ni, 3, CoNi, 4), have been hydrothermally synthesized, and structurally and magnetically characterized. In these isomorphous CPs, octahedrally coordinated metal ions are linked by the single - carboxylate bridge (μ-COO) to give linear trinuclear motifs. The motifs are connected through the other single - carboxylate bridge (μ-COO) to give a 2D (4,4) layer, and the layers are interlinked by the L ligands into 3D frameworks.

Highly Efficient Red-Emitting Carbon Dots with Gram-Scale Yield for Bioimaging.

Carbon dots (CDs) are a new class of photoluminescent (PL), biocompatible, environment-friendly, and low-cost carbon nanomaterials. Synthesis of highly efficient red-emitting carbon dots (R-CDs) on a gram scale is a great challenge at present, which heavily restricts the wide applications of CDs in the bioimaging field. Herein, R-CDs with a high quantum yield (QY) of 53% are produced on a gram scale by heating a formamide solution of citric acid and ethylenediamine.

2D carboxylate-bridged Ln coordination polymers: displaying slow magnetic relaxation and luminescence properties in the detection of Fe, CrO and nitrobenzene.

Eight new 2D isostructural lanthanide coordination polymers (Ln-CPs), [Ln(HL)(HO)(NO)]·NO (1-Ln), Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, and Yb ions, HL = 4-(3,5-dicarboxylphenyl)-2-methylpyridine, were synthesized by using solvothermal methods and studied by structural analyses, magnetic analyses and luminescent probes. Crystallographic studies revealed that these compounds are 2D frameworks in which dinuclear units with double μ-syn,syn-carboxylate bridges are interlinked by single μ-trans,trans-carboxylate bridges from organic spacers. The layers are further stabilized and combined into 3D architectures through intra- and interlayer ππ stacking interactions and hydrogen bonding, respectively.

Facile synthesis of red-emitting carbon dots from pulp-free lemon juice for bioimaging.

In this work, red-emitting carbon dots (R-CDs) with a high quantum yield (QY) of 28% in water were synthesized for the first time by heating an ethanol solution of pulp-free lemon juice. The obtained R-CDs were mono-dispersed with an average diameter of 4.6 nm, and exhibited excitation-independent emission at 631 nm.

Synthesis and characterization of polyion complex micelles and their controlled release of folic acid.

Stable and narrow distribution polyion complex micelles (PICMs) were prepared in an aqueous milieu through electrostatic interaction between a pair of oppositely charged block copolymers poly(N-vinylpyrrolidone)-block-poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PVP-b-PAMPS) and monomethoxy poly(ethylene glycol)-block-poly(4-vinyl pyridine) (PEG-b-P4VP). The critical aggregate concentration (CAC), hydrodynamic size, and surface morphology of the prepared PICMs were characterized by fluorescence spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM), respectively. The resulting CAC and the average diameter of the PICMs were about 43 mg/L and 121 nm, indicating high structural stability of micelles and a size favorable for delivery of drug.

[Periodic and fractal precipitation in ATP-Co(2+)-decoxycholate gel system].

In the simulation experiments in vitro of the formation of gallstone, adenosine-triphosphate(ATP)-Co(2+)-deoxycholic acid(DC) gel system was chosen to study the periodic precipitation progress. The effect of ATP on the Co(2+)-DC gel system was also determined, and the structure of the periodic precipitation formed was characterized by FTIR. The results show that the patterns formed in the systems with ATP are different, ATP affected the rate and structure of precipitation through its variable participation in the metal coordination complexes as judged by the phosphate P=O bands and the deoxycholate COO- symmetric and asymmetric vibration bands as measured by FTIR Theses spectroscopic differences were correlated with color and pattern differences in the precipitates.

Preparation and properties of a pH/temperature-responsive carboxymethyl chitosan/poly(N-isopropylacrylamide)semi-IPN hydrogel for oral delivery of drugs.

Thermo- and pH-responsive semi-IPN polyampholyte hydrogels were prepared by using carboxymethylchitosan and poly(N-isopropylacrylamide) with N,N'-methylenebisacrylamide (BIS) as the crosslinking agent. The swelling characteristics of these hydrogels at distinct compositions as a function of pH and temperature were investigated. It was found that the semi-IPN hydrogels demonstrated the pH- and temperature-responsive nature of the materials, and it also showed good reversibility.

Preparation and characterization of temperature and pH-sensitive chitosan material and its controlled release on coenzyme A.

A novel copolymer P(CS-Ma-DMAEMA) was synthesized with chitosan (CS), maleic anhydride (Ma) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) by grafting and copolymerization. The copolymer obtained was analyzed by FT-IR, (1)H NMR and UV, and the molecular weight and polydispersity were determined by gel permeation chromatography (GPC). The average size and distribution of copolymer micelles were determined by dynamic light scattering (DLS).

[Study on the structure of periodic and chaotic patterns of AMP-DC-Cu-gel systems].

This is an in vitro model to mimic the conditions present during gallstone formation. Adenosine mono-phosphate (AMP), an important bio-molecule, was chosen. Its effect on the formation of periodic/chaotic patterns in the deoxycholate-CuCl2-gel and deoxycholate-CuCl2-glucose-gel systems were studied.