Comparative Study of the Structural Characteristics and Bioactivity of Polysaccharides Extracted from Aspidopterys obcordata Hemsl. Using Different Solvents.

The polysaccharides extracted from Aspidopterys obcordata are thought to have anti-urolithiasis activity in Drosophila kidney stones. This study aimed to assess the effects of different extraction solvents on the yield, chemical composition, and bioactivity of polysaccharides from A. obcordata. A. obcordata polysaccharides were extracted by using four solutions: hot water, HCl solution, NaOH solution, and 0.1 M NaCl. The results revealed that the extraction solvents significantly influenced the extraction yields, molecular weight distribution, monosaccharide compositions, preliminary structural characteristics, and microstructures of polysaccharides. The NaOH solution's extraction yield was significantly higher than the other extraction methods. Vitro antioxidant activity assays revealed that the NaOH solution extracted exhibited superior scavenging abilities towards DPPH and ABTS radicals and higher FRAP values than other polysaccharides. The vitro assays conducted for calcium oxalate crystallization demonstrated that four polysaccharides exhibited inhibitory effects on the nucleation and aggregation of calcium oxalate crystals, impeded calcium oxalate monohydrate growth, and induced calcium oxalate dihydrate formation. The NaOH solution extracted exhibited the most pronounced inhibition of calcium oxalate crystal nucleation, while the hot water extracted demonstrated the most significant suppression of calcium oxalate crystal aggregation. Therefore, it can be inferred that polysaccharides extracted with NaOH solution exhibited significant potential as a viable approach for extracting polysaccharides from stems due to their superior yield and the remarkable bioactivity of the resulting products.

Triangular Silver Nanoplate-Coated ZnO Nanoflowers Photocatalysis of Norfloxacin Under Visible Light.

T-Ag/ZnO nanoflowers were successfully fabricated via two steps methods on zinc foil. The chemical composition of norfloxacin was investigated by FTIR spectroscopy. The morphology, composition, and structural and optical properties of the as-synthesized materials were characterized. The results show that triangular silver nanoplates exhibit unique surface plasmon resonance (SPR) absorption spectra, and the absorption spectrum range of ZnO nanoflowers are effectively expanded by coating triangular silver nanoplates. The photocatalytic degradation of norfloxacin activity can be obviously improved because of a synergetic effect and unique SPR of triangular silver nanoplates in the T-Ag/ZnO nanoflowers under visible light. In addition, the possible mechanism for T-Ag/ZnO nanoflowers for the photodegradation of norfloxacin are discussed. The stability of T-Ag/ZnO nanoflowers are also studied.

Dendrimer modified magnetic nanoparticles as adsorbents for removal of dyes.

The recycling of dendrimers using an ultrafiltration membrane during wastewater treatment is extremely inconvenient. With the combination of magnetic nanoparticles (MNP) with dendrimers, the problem of the recovery of tiny particulate matter from an aqueous solution can be overcome using its magnetism. In this study, the coprecipitation method was adopted to prepare MNP, and then MNP-G(n) (n, generations of dendrimers) was prepared with the formation of the dendrimers on the surface of the MNP. The adsorption of reactive black 5 (RBk5) from an aqueous solution using MNP-G(n) was studied. It was shown that the adsorption data of the composite could be fitted using the Langmuir equation with a maximum adsorption capacity of 70.423 mg g(-1) in the aqueous solution of RBk5 at 25 degrees C. The effects of the initial RBk5 concentration, pH and dendrimer generation were studied and the optimized experimental conditions were obtained. The adsorption capacity increased as the generation of MNP-G(n) increased, and decreased with the rise of the solution pH value. The adsorption of RBk5 with the prepared MNP-G(n) composite was very efficient, and the adsorbent could be recycled using magnetic separation.

Establishment of a Fast Chemical Identification System for screening of counterfeit drugs of macrolide antibiotics.

A Fast Chemical Identification System (FCIS) consisting of two colour reactions based on functional groups in molecules of macrolide antibiotics and two TLC methods was developed for screening of fake macrolide drugs. The active ingredients could be extracted from their oral preparations by absolute alcohol. Sulfuric acid reaction as a common reaction of macrolides was first used to distinguish the macrolides from other types of drugs and then 16-membered macrolides and 14-membered ones were distinguished by potassium permanganate reactions depending on the time of loss of colour in the test solution; after which a TLC method carried out on a GF(254) plate (5 cm x 10 cm) was chosen to further identification of the macrolides. The mobile phase A consisting of ethyl acetate, hexane and ammonia (100:15:15, v/v) was used for the identification of 14-membered macrolides, and the mobile phase B consisting of trichloromethane, methanol and ammonia (100:5:1, v/v) was used for the identification of 16-membered ones. A suspected counterfeit macrolide preparation can be identified within 40 min. The system can be used under different conditions and has the virtues of robustness, simplicity and speed.

[Screening of molecular markers of lung squamous cell carcinoma by microarrays].

OBJECTIVE: To identify molecular markers of lung squamous cell carcinoma by cDNA microarray technique. METHODS: cDNA expression profiles were examined by microarrays of 6 surgical specimens of stage I lung squamous cell carcinomas. Those genes, either up-regulated or down-regulated in every specimen studied, were identified. The expression levels of nm23 and BRCA2 by the squamous cell carcinoma of the lung were further examined by immunohistochemical techniques. RESULTS: A total of 107 genes were identified, of which 26 were up-regulated and 81 were down-regulated in all six specimens. Immunohistochemical staining showed that, compared with normal lung tissues, the intensity of nm23 expression by the squamous cell carcinoma of lung was significantly increased while that of BRCA-2 was decreased. CONCLUSION: cDNA microarrays can be used to identify gene expression profile of lung cancer, some of which may be used as markers of lung squamous cell carcinoma.