Advanced Materials Research Vol. 699

Abstract: Heat shock protein 72 (HSP72) and glycoprotein 96 (gp96) are highly expressed in cancer tissues. Recent studies indicate the possible roles of HSP72 and gp96 in the development and progression of gastrointestinal carcinomas but detailed information is still ambiguous. The aim of the study is to investigate the correlation between clinicopathology and expression of HSP72 and gp96 in human common gastroenterological cancers- esophageal squamous cell carcinoma, gastric adenocarcinoma, colonic adenocarcinoma and hepatocellular carcinoma. The results showed that HSP72 and gp96 were highly expressed in gastroenterological carcinomas. HSP72 and gp96 were mainly stained in cytoplasm. HSP72 and gp96 expression were significantly associated with the presence of tumor infiltration, lymph node and remote metastasis. The results indicate that there exists a significant correlation between the expression of HSP72 and gp96 and the progression of gastroenterological carcinomas.

Abstract: Nanotechnology has the potential to produce a variety of new materials in the coming years, as a result of the design of novel nanoparticles with new physicochemical characteristics. However, their potential to adversely affect the environment and human health must be addressed. The toxicity of polystyrene latex (PSL) nanoparticles with various functional groups toward Escherichia coli KP7600 strain was investigated using the colony count method, and confocal microscopy observations. It was found that the positively charged PSL nanoparticles led to the death of the bacterial cells. Confocal observations of the bacterial cells after 1 h of exposure to the amine-modified, positively-charged PSL nanoparticles in an aqueous NaCl solution showed that the surfaces of the dead cells were almost entirely covered with the nanoparticles. No uptake of the nanoparticles into the bacterial cells was observed, regardless of the cell viability. It is likely that the adhesion of the positively charged nanoparticles onto the surface of the bacterial cells (due to the electrostatic attractive force) caused a decrease in the fluidity of the cell membrane, and the inhibition of metabolism through the cell membrane led to the death of the bacterial cells.

Abstract: A new composite sorbent based on carbonized rice husk (CRH) and immobilized on it inactivated cultural liquid containing antimicrobials of Bacillus subtilis CK-245 is developed. The sorption and antimicrobic activity of CRH concerning five species of Enterobacteriaceae is studied. Prospects of use of developed sorbent in medicine and veterinary science is shown.

Abstract: Theophylline (TP) is an oral bronchodilator medicine, used to treat respiratory diseases. The problem of TP is low aqueous solubility, slow release tablets, and solid state interconversion between anhydrous and monohydrate forms as a function of relative humidity (RH). Physicochemical properties of this medicine, including solubility, humidity sensitivity, and chemical and physical stability can be improved by cocrystallizing with another compound. Herein we present the cocrystallization of TP with salicylic acid (SA) and picolinic acid (PI). Mixtures of 2:1 TP-SA and TP-PI were screened by solvent-drop grinding, crystal growth by slow evaporation and pH control at 2.0 and 7.0, and compared to the 1:1 crystalline products of TP-SA and TP-PI. The products were characterized by XRD, FT-IR/FT-Raman, and DSC/TG. Crystals of the 1:1 TP-SA, 1:1 TP-PI, and pure TP were stored at room temperature (342 °C) with 582% RH for one month and their stability examined by FT-IR.

Abstract: Three new rare earth ternary complexes (NdLL'•4H2O, EuLL'•4H2O and LaLL'•4H2O) have been prepared with rare earth nitrates, tryptophan (L) and sodium citrate (NaL'). The characteristics of the complexes were identified by elemental analysis, IR, molar conductivity solubility and TG-DTA. The results showed the complexes have constant composition of RELL'•4H2O. And all of the rare earth ternary complexes have anticoagulant action.

Abstract: A freshwater macroalga, Spirogyra spp., were analyzed for its phytochemical composition, antioxidant activity and total phenolic content (Folin−Ciocalteu method). Phytochemical analysis of Spirogyra neglecta revealed presence of phenolics, tannins, glycosides and saponins. The crude extraction of Spirogyra spp. was carried out using two solvents via, methanol (methanolic extract) and water (aqueous extract). The total phenolic contents of crude extracts were shown at 346.58±1.61 and 589.77±1.65 mg gallic acid equivalents/g extract in aqueous and methanolic extracts, respectively. The antioxidant capacity of aqueous and methanolic extract was estimated by two different methods; ABTS assay, and DPPH assay. The antioxidant activity of two extracts is affected by the extracting solvent and different assay. In the DPPH scavenging assay and ABTS assay, both extracts showed high antioxidant activity. In addition, the high correlation between results of all antioxidant activities and total phenolic content was found. The rapid TLC assay in methanolic extract is considered as the rapid test to evaluate the antioxidant activity of natural compounds. The compounds showing four bands at Rf = 0.25, 0.35, 0.42, 0.64. This study showed that Spirogyra spp. might constitute an important source of natural antioxidants.

Abstract: Stemonal and 6-deoxyclitoriacetal, rotenoid compounds were isolated from the dried roots of Stemona collinsae Craib. Stemonal was recrystallized with methanol. Crystal structure of stemonal displayed only the planar structures while that of 6-deoxyclitoriacetal showed both the planar and bent shape structures. Stemonal and 6-deoxyclitoriacetal were tested their cytotoxic activities against three cancer cell lines and found that only 6-deoxyclitoriacetal has been showed the cytotoxicity.

Abstract: The antifungal activity of crude extracts of M. pudica Linn. was evaluated by determining the minimum inhibitory concentration (MIC) of the solvent extracts. Subsequently, an antifungal assay was carried out by determining the inhibition of radial growth in PDA plates added with plant extracts. MIC value of crude extracts was 15.00, 18.50 and 19.50 µg/mL for 95% ethanol, dichloromethane and acetone extracts, respectively. Concerning the inhibition of radial growth, ethanol crude extracts of M. Pudica was most effective and exhibited highest antifungal activity of 55.65% at 10.00 µg/mL, 54.02% at 1.00 µg/mL, 50.95% at 0.10 µg/mL, and 48.70% at 0.01 µg/mL against C. gloeosporioides., respectively. The highest yield was found in 95% ethanol at 73 mg/g. The higher yield was presented when the higher polar solvents were used in this experiment. Since factors such as solvent of extraction may influence the properties of derived crude extract, different extraction methods may be of interest for further trial.

Abstract: Using Yb(NO₃)₃•6H₂O and Fe(NO₃)₃•9H₂O as raw material, the YbFeO₃ nanoparticles were synthesized by microwave assisted method. The YbFeO₃ nanoparticles were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the prepared YbFeO₃ show an average grain size of 80 nm in diameter, and strong visible-light absorption with absorption onset of 608 nm, indicating a narrow optical band gap of 2.04eV. Consequently, the YbFeO₃ nanoparticles show high photocatalytic activity for decomposition of methylene blue under visible-light irradiation.

Abstract: Research has been focused on the development of molecularly imprinted polymers using a chitosan derivative as the precursor. An O-acyl chitosan was synthesized by the selective protection of amino groups of chitosan in MeSO₃H and was cross-linked with glutaraldehyde in the presence/ absence of template molecule, cholesterol. The effect of the degree of the acyl substitution on the selection of precursor was investigated, regarding the solubility of chitosan derivative, interaction between the precursor and imprinted molecule, and degree of the cross-linking of precursor. The rebinding experiments indicated the significant recognition for cholesterol with imprinted polymer as compared with non-imprinted polymer. It was found that a good binding capacity of the imprinted polymer towards cholesterol could be achieved in a less-polar solvent. And the O-acyl chitosan-based molecularly imprinted polymer obtained displayed good recognition selectivity for cholesterol in comparison to similarly strctural analogue, cholesterol acetate.