Novel aqueous biphasic system based on ionic liquid for the simultaneous extraction of seven active pharmaceutical ingredients in aquatic environment.

Nonsteroidal anti-inflammatory drugs and antibiotics are classes of active pharmaceutical ingredients (APIs), which are continuously contaminating the ecosystem through various anthropogenic activities. Because of their pseudo-persistence in the aquatic environment and their potentially chronic effects on aquatic life, it is important to closely monitor their concentrations in the aquatic environment using a sensitive analytical method. Sustainable aqueous biphasic systems (ABSs) composed of ionic liquids and biodegradable organic salt (sodium malate) were proposed. The phase diagrams of the systems were firstly determined, and [N4444]Cl-based ABS was selected for the simultaneous extraction and preconcentration of seven APIs. With the developed ABS, extraction efficiencies of APIs close to 100% were obtained. For the developed method, limits of detection (LODs) of 45, 65, 76, 14, 60, 48, and 51 ng L-1 were obtained for indomethacin, ibuprofen, diclofenac, naproxen, ketoprofen, flurbiprofen, and chloramphenicol, respectively, providing from 1216- to 1238-fold improvement as compared with the analysis without preconcentration. From an economic and environmental point of view, we can predict the prospects and competitive position of the method developed.

The thermal stabilities of luminescence and microstructures of Eu2+-doped KBaPO4 and NaSrPO4 with ß-K2SO4 type structure.

Eu(2+)-doped monophosphates NaSrPO(4) and KBaPO(4) with the ß-K(2)SO(4) structure were synthesized using the conventional high temperature solid state reaction. The X-ray powder diffraction, photoluminescence excitation, and emission spectra and decay curves were measured. The phosphors can be efficiently excited by UV-visible light from 220 to 430 nm to realize emission in the visible range. The natures of the Eu(2+) emission, e.g., the chromaticity coordinates, the Stokes shifts, and the luminescence absolute quantum efficiencies, were reported. The luminescence quenching temperatures and the thermal activation energies for NaSrPO(4):Eu(2+) and KBaPO(4):Eu(2+) were obtained from the temperature dependent (10-435 K) luminescence intensities and decay curves. KBaPO(4):Eu(2+) presents only one emission center; however, Eu(2+) ions have a "disordered environment" in NaSrPO(4) lattices. The relationship between the luminescence thermal stabilities and the crystal structures was discussed. The crystallographic occupations of rare earth ions doped in these hosts were analyzed by the site-selective emission spectra and the excitation spectra of Eu(3+) ions in the (7)F(0)→(5)D(0) transitions using a pulsed, tunable, and narrow-band dye laser. In KBaPO(4), the Eu(3+) ions could be distributed in the host with a high "ordered state" in only one site in the lattices. However, the multiple site structure of Eu(3+) ions with highly disordered distributions in NaSrPO(4) lattices was suggested.

The luminescence characterization and structure of Eu2+ doped LiMgPO4.

An Eu(2+)-doped LiMgPO(4) phosphor was prepared by a high temperature solid-state reaction. The formation was confirmed by x-ray powder diffraction measurements to be a single LiMgPO(4) phase. The photoluminescence excitation and emission spectra were investigated. The luminescence shows a broad emission from the 4f(6)5d → 4f(7)(8)S7/2) transition at room temperature. At low temperature the zero-phonon line for transitions to the 4f(7) ((8)S(7/2)) level of the 4f(6)(7)Fj)5d1 excited state is observed at 360 nm and it is found that the emission line of the 4f(7)(6)P7/2) → 4f(7)(8)S7/2) transition overlaps the zero-phonon line at nearly the same position of 360 nm. The influences of temperature on the luminescence spectra and decay times were investigated. The doping mechanism of Eu(2+) ions in LiMgPO(4) was discussed. The Eu(2+) ions were suggested to occupy the Li(+) sites in LiMgPO(4) to induce the small crystal field splitting and weak nephelauxetic effect.

Expression of epidermal growth factor and epidermal growth factor receptor in rat periodontal tissues during orthodontic tooth movement.

OBJECTIVE: To detect the expression and distribution of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) in periodontal tissues, and analyze the role of EGF in orthodontic tooth movement. METHODS: According to Kings methods, 40 g mesial force was applied to pull the left maxillary first molar in the rat. Using immunohistochemical method (HI-SABC method) to localize and examine the expression of EGF and EGFR in decalcified alveodental connective tissues at 24 hours and 168 hours of tooth movement. RESULTS: EGF and EGFR were stained at some of periodontal ligament of furcation and radical regions in control group. These expressions of EGF and EGFR increased in periodontal tissues (P < 0.01), with the expressions at 168 hours higher than those at 24 hours (P < 0.01). And levels of EGF and EGFR at tension side were higher than those at pressure side at the same time (P < 0.01). CONCLUSIONS: Epidermal growth factor participated in the tissues remodeling during orthodontic tooth movement and especially played a more important role in orthodontic bone formation.