[Spectroscopic Study of Salbutamol Molecularly Imprinted Polymers].

In order to solve the problem of on-site rapid detection of salbutamol residues in feed and animal products, and develop a new method of fast detection of salbutamol on the basis of the molecular imprinting technology, this article uses the salbutamol (SAL) working as template molecule, methacrylic acid (MAA) working as functional monomer. On this basis, a new type of core-shell type salbutamol molecularly imprinted polymers were prepared with colloidal gold particles as triggering core. Superficial characteristics of the MIPs and the related compounds were investigated by ultraviolet (UV) spectra and infrared (IR) spectra, Raman spectra, Scanning electron microscopy (SEM) respectively. The results indicated that a stable hydrogen bonding complex has been formed between the carboxyl groups of SAL and MA with a matching ratio of 1:1. The complex can be easily eluted by the reagent containing hydrogen bonding. The chemical binding constant K reaches -0.245 x 106 L² · mol⁻². The possible binding sites of the hydrogen bonding was formed between the hydrogen atoms of -COOH in MA and the oxygen atoms of C==O in SAL. IR and Raman spectrum showed that, compared with MA, a significant red shift of -OH absorption peak was manifested in MIPs, which proved that SAL as template molecule occurred a specific bond between MA. Red shift of stretching vibration absorption peak of C==O was also detected in the un-eluted MIPs and obvious energy loss happened, which demonstrated a possible binding sites is SAL intramolecular of C==O atom of oxygen. If the hydrogen atoms of -COOH in MA wanted to generate hydrogen bond. However, the shapes of absorption peak of other functional groups including C==C, C==O, and -OH were very similar both in MIPs and NIPs. Specific cavities were formed after the template molecules in MIPs were removed. It was proved by the adsorption experiment that the specific sites in these cavities highly match with the chemical and space structure of SAL. Besides, colloidal gold type core-shell molecularly imprinted polymers have looser surface, more cavities in the surface compared with ordinary molecularly imprinted polymers, which increased the effective area of adsorption to target molecules. So it have better performance in adsorption. Based on the principle that these cavities can specificly recognize and combine with target molecule in the test sample, and the excellent ability of colloidal gold core-shell molecularly imprinted polymers, the development of novel methods for fast determination of SAL based on the molecular imprinting technology can be expected in the near future.

A long noncoding RNA MAP3K1-2 promotes proliferation and invasion in gastric cancer.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been implicated in several human cancers. The expression profile and underlying mechanism of the lncRNA MAP3K1-2 in gastric cancer (GC) are poorly understood. METHODS: Sixty-one patients with GC were recruited from Shanghai Baoshan Luo Dian Hospital (Shanghai, China). Tumor tissues and paired normal tissues (5 cm adjacent to the tumor) were obtained. Expression of lncRNA MAP3K1-2 in GC cell lines was examined using quantitative real-time polymerase chain reaction. Protein expression was detected using Western blot. Cell cycle analysis was assessed using flow cytometry. Cell proliferation was assessed using soft agar assays, and cell invasion was assessed using Transwell assays. RESULTS: The expression level of lncRNA MAP3K1-2 was upregulated in GC cells and markedly higher in poorly differentiated cell lines. Silencing treatment of lncRNA MAP3K1-2 significantly inhibited cell proliferation and invasion in GC. In addition, knockdown of lncRNA MAP3K1-2 significantly inhibited the function of important genes in the MAPK signaling pathway. Higher expression of lncRNA MAP3K1-2 was often associated with poorer prognosis in patients with GC. CONCLUSIONS: lncRNA MAP3K1-2 is a critical effector in GC tumorigenesis and progression, representing novel therapeutic targets. High lncRNA MAP3K1-2 expression may serve as a novel independent prognostic marker for predicting the outcome of GC.

Development of a mercury detection kit based on melamine-functionalized gold nanoparticles.

A fast and simple mercury detection kit was developed based on melamine-functionalized gold nanoparticles (GNPs). The detection kit contained reagent 1 (GNPs), reagent 2 (melanine), a reaction cuvette with four separated cells, a colorimetric card and a plastic pipette. The GNPs were prepared by a citrate reduction of HAuCl4. A proper amount of melamine was applied to functionalize the GNPs. The complex reaction took place in the present of Hg(2+) in the test samples, leading to the combination of Hg(2+) with the C=N group of melamine located on the surface of the GNPs. This reaction resulted in damage to the stability of colloid gold, and the aggregation of GNPs occurred. Different color changes (from claret-red to lilac, purple and plum) were displayed with different concentrations of Hg(2+) in the test samples. It was very easy and convenient to determine the amount of mercury ion by the naked eye. The advantages of this methodology are listed as follows: a short detecting time (within 10 min), a high specificity (no significant interference was indicated upon adding a certain amount of Cu(2+), Pb(2+), Zn(2+), Mg(2+), Cd(2+) and Fe(2+)), high sensitivity with a detection limit of 0.01 mg L(-1) , easy operation and practical on-site use.