Qianming Wang

Optical and electrochemical responses of an anthrax biomarker based on single-walled carbon nanotubes covalently loaded with terbium complexes

An effective single-walled carbon nanotube (SWNT) covalently loaded with unsaturated terbium emissive material was designed for specific and rapid (2-3 s) detection of calcium dipicolinate (CaDPA) (detection limit 1 μM). The nanoprobe was successfully assembled onto electrodes and its sensing abilities were investigated through electrochemical measurement. Cyclic voltammetry curves were selectively responsive to calcium dipicolinate compared with benzoic acid, o-phthalic acid and m-phthalic acid. This novel material provides dual opto-electrochemical recognition of the anthrax biomarker CaDPA.

Systematic review and meta‐analysis of the effectiveness and safety of extended lymphadenectomy in patients with resectable gastric cancer

The extent of lymphadenectomy in the treatment of gastric cancer has been debated for more than two decades. This meta‐analysis sought to evaluate the effectiveness and safety of extended lymphadenectomy in patients with gastric cancer.

Anion/cation induced optical switches based on luminescent lanthanide (Tb3+ and Eu3+) hydrogels.

Two novel silica based lanthanide complexes (Tb(a)2 and Eu(a)2) were encapsulated into poly(acrylic acid) host. Both Tb(III) and Eu(III) containing hydrogels have typical and easily distinguished narrow line emissions occurring in the green and red region respectively. Particularly, the excitation wavelength for Eu complex can be extended into nearly visible light range (λex = 395 nm). Interestingly, we discover that these target materials not only exhibit selective emission response towards HSO4− (detection limit 10−5 m) compared with CH3COO−, F−, Cl−, Br− and I− but also give unique quenching to Cu2+ (detection limit 10−5 m) (tested cations: Cu2+, Pd2+, Cd2+, Co2+ and Mn2+). More importantly, this kind of materials can be recycled more than 10 times.

A luminescent lanthanide complex-based anion sensor with electron-donating methoxy groups for monitoring multiple anions in environmental and biological processes

We designed a ternary europium (III) tris(2-thenoyltrifluoroacetonate) with 2-(3,4,5-trimethoxyphenyl)imidazo[4,5-f]-1,10-phenanthroline (1) ligands for the luminescent detection of various anions, such as fluoride, acetate and dihydrogen phosphate. Characterization of the sensors photophysical properties and via NMR showed that the sensor exhibits striking emission changes to fluoride (purple), acetate (green) and dihydrogen phosphate (blue) anions, respectively. Its fluorescence lifetime was determined to be 1.10 ms for europium ions and the complex showed an overall quantum yield of 10% in DMSO. Furthermore, transparent hybrid thick films composed of the europium complex and poly-methyl methacrylate matrix were successfully prepared via copolymerization. The resulting film overall displayed intense red emissions associated with europium ions. Fluorescence microscopic evaluation showed a homogenous distribution of aggregates with average diameters of 30-50 μm throughout the film. The accordingly produced film could give rise to a luminescence change to purple in response to fluoride anions.

Profilin 1 is essential for retention and metabolism of mouse hematopoietic stem cells in bone marrow

How stem cells interact with the microenvironment to regulate their cell fates and metabolism is largely unknown. Here we demonstrated that the deletion of the cytoskeleton-modulating protein profilin 1 (pfn1) in hematopoietic stem cell (HSCs) led to bone marrow failure, loss of quiescence, and mobilization and apoptosis of HSCs in vivo. A switch from glycolysis to mitochondrial respiration with increased reactive oxygen species (ROS) level was also observed in HSCs on pfn1 deletion. Importantly, treatment of pfn1-deficient mice with the antioxidant N-acetyl-l-cysteine reversed the ROS level and loss of quiescence of HSCs, suggesting that the metabolism is mechanistically linked to the cell cycle quiescence of stem cells. The actin-binding and proline-binding activities of pfn1 are required for its function in HSCs. Our study provided evidence that pfn1 at least partially acts through the axis of pfn1/Gα13/EGR1 to regulate stem cell retention and metabolism in the bone marrow.

Novel lanthanide pH fluorescent probes based on multiple emissions and its visible-light-sensitized feature

A new type of Eu(III) ofloxacin complex as the fluorescent pH indicator has been presented. Compared to pure ligand, the complex offers more distinguished color changes (green-red-blue) derived from both lanthanide line emissions and the secondary ionization steps of ofloxacin. During the concentration dependence experiments, the photoluminescence studies on the complex showed that the excitation of this pH probe can occur at a very long wavelength which extends to visible range (Ex=427 nm). Furthermore, the functional complex was successfully incorporated into soft networks and two novel luminescent hydrogels (rod and film) were fabricated. The soft materials also exhibited specific responses towards the pH variation. Finally, the onion cell-stain experiments were carried out to further confirm the validity of pH dependence and the results support the idea that the material will be suitable for monitoring biological samples in the future.

Luminescent Cu2+ Probes Based on Rare-Earth (Eu3+ and Tb3+) Emissive Transparent Cellulose Hydrogels

Cellulose hydrogels are biodegradable materials that can be applied as accommodating hosts for various species. Here we report the preparation of novel thin films based on luminescent cellulose hydrogels. The spectroscopic behavior of these soft materials and their sensing effects are investigated. Interestingly, we found that these films only give selective signal changes in the presence of Cu2+ in water in comparison with Na+, K+, Ag+, Mn2+, Co2+, Ca2+, Cd2+, Hg2+, Pd2+, Mg2+, Ni2+, Fe2+, and Fe3+. High visible-light transmittance and good flexibility for these films can be observed. More importantly, the thermal stability of rare-earth complexes could be significantly enhanced in aqueous solution as result of the protection by hydrogel matrix.

Supersonic microwave co-assistance (SMC) efficient synthesis of red luminescent Eu3+ activated silver molybdates and their phase-dependent evolution processes

The chemical effects of high intensity ultrasound and microwave irradiation on the preparation of europium(III) activated silver molybdates were investigated and characteristic red emission was successfully achieved at a very low temperature (70 °C) in 40 minutes. X-ray powder diffraction results proved that the crystal phase of silver molybdate was heavily related to the pH value. Scanning electron microscopic images revealed rod-like structures of Ag2Mo3O10·1.8H2O and Ag2Mo2O7 were obtained in the range of pH values between 2 and 5, while growing particles of Ag2MoO4 were formed at pH values of 7 and 8. Furthermore, it has been found that the encapsulation of europium(III) in monoclinic crystal structure (Ag2Mo2O7) resulted in enhanced luminescence intensities compared to other crystal phases.

Multiple irradiation triggered the formation of luminescent LaVO4: Ln3+ nanorods and in cellulose gels

A systematic study of the preparation of lanthanide (Eu3+, Tb3+, Sm3+ and Dy3+) phosphors was carried out and luminescent materials (red, green, orange-red and blue-yellow) were successfully achieved at low temperature (70 °C) in 45 min, using simultaneous supersonic and microwave irradiation. Scanning and transmission electron microscopic images indicate that one-dimensional nanorods with diameters of 10–20 nm and lengths of up to 200 nm were formed. The phosphors were entrapped in cellulose gels and the corresponding hydrogels were also strongly emissive.

Nucleophilic Addition-Triggered Lanthanide Luminescence Allows Detection of Amines by Eu(thenoyltrifluoroacetone)3

Herein, a novel fluorescent indicator for the real‐time monitoring of amines is described. This probe contains a complex of europium‐(thenoyltrifluoroacetone)3 (Eu(TTA)3) that efficiently reacts with primary and secondary amines. The electron‐withdrawing trifluoroacetyl undergoes a nucleophilic addition with amines, and the complex was used to selectively detect BuNH2 and Et2NH (quenching concentration for BuNH2: 10−4 m, for Et2NH: 1.2 × 10−3 m) by monitoring emission; no changes were observed in the emission spectrum of Eu(TTA)3 in the presence of Et3N, [Bu4N]Cl, or PhNH2 in aqueous solution (THF/H2O = 1:1). The ratio of emission intensity to amine concentration was linear by the least‐squares fitting method.