Effect of Walnut Meal Peptides on Hyperlipidemia and Hepatic Lipid Metabolism in Rats Fed a High-Fat Diet.

As a natural active substance that can effectively improve blood lipid balance in the body, hypolipidemic active peptides have attracted the attention of scholars. In this study, the effect of walnut meal peptides (WMP) on lipid metabolism was investigated in rats fed a high-fat diet (HFD). The experimental results show that feeding walnut meal peptides counteracted the high-fat diet-induced increase in body, liver and epididymal fat weight, and reduce the serum concentrations of total cholesterol, triglycerides, and LDL-cholesterol and hepatic cholesterol and triglyceride content. Walnut meal peptides also resulted in increased HDL-cholesterol while reducing the atherosclerosis index (AI). Additionally, the stained pathological sections of the liver showed that the walnut meal peptides reduced hepatic steatosis and damage caused by HFD. Furthermore, walnut meal peptide supplementation was associated with normalization of elevated apolipoprotein (Apo)-B and reduced Apo-A1 induced by the high-fat diet and with favorable changes in the expression of genes related to lipid metabolism (LCAT, CYP7A1, HMGR, FAS). The results indicate that walnut meal peptides can effectively prevent the harmful effects of a high-fat diet on body weight, lipid metabolism and liver fat content in rats, and provide, and provide a reference for the further development of walnut meal functional foods.

[CdSe/ZnSe quantum dots via a two-phase solution system process solubilization and spectroscopic characterization].

In the present work, the CdSe/ZnSe core/shell quantum dots (QDs) were successfully transferred from organic phase to water phase via a two-phase solution system process by surface coating with amphiphilic polymer. Surface coating with amphiphilic polymer is an effective method, which can form stable soluble QDs in water. However, the conventional polymer coating method is performed in homogeneous phase, and it easily induces the aggregation of the QDs attributing to the long chain of enlace of the polymer. It is thus necessary and meaningful to develop surface coating technique for getting monodisperse coating QDs with amphiphilic polymer. In comparison with previously reported coating method, the authors' experiment process is performed in two-phase solution system, and can effectively reduces the possibility of aggregation of the QDs. The resulting hydrophilic CdSe/ZnSe core/shell QDs have long-term stability in water, and high quantum yield. The polymer coating process was affirmed by various characterizations. Fourier transform infrared spectra suggest that the octylamine modified polymer was successfully coated on the surface of the CdSe/ZnSe QDs. The transmission electron microscopy suggests that the size and shape of the QDs showed no obvious change before and after the coating process. Dynamic light scattering results indicate that the hydrophilic QDs exhibit narrow hydrodynamic size distribution with the mean hydrodynamic diameters of about 19.7 nm. The luminescence properties of the QDs were investigated with photoluminescence spectra and ultraviolet-visible absorption spectra. This polymer coating process has less effect on luminescence capability. The quantum yield decreased from 43% to 30%. Further, in order to confirm that the polymer capped QDs is biocompatible, the QDs were used for specific detection of the human IgG with fluorescence mapping. The specific molecular recognition capacity of goat anti-human IgG-modified QDs confirms that the polymer coated QDs have compatible functional chemical groups for bioconjugation and are suitable for biological applications.

[Effect of hole transporting materials on photoluminescence of CdSe core/shell quantum dots].

Photoluminescence quenching of colloidal CdSe core/shell quantum dots in the presence of hole transporting materials was studied by means of steady state and time resolved photoluminescence spectroscopy. With increasing hole transporting materials concentration in the CdSe core/shell quantum dot solution, the photoluminescence intensity and lifetime decreased gradually. The photoluminescence quenching of CdSe/ZnSe quantum dots with adding hole transporting material N,N'-bis(1-naphthyl)-N, N'-diphenyl-1,1 '-biphenyl-4, 4'-diamine (NPB) is more efficient than N,N'-diphenyl-N, N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD). And compared with CdSe core/shell quantum dots with ZnSe shell, the ZnS shell is an effective one on the surface of CdSe quantum dots for reducing photoluminescence quenching efficiency when interacting with hole transporting material TPD. Based on the analysis, there are two pathways in the photoluminescence quenching process: static quenching and dynamic quenching. The static quenching results from the decrease in the number of the emitting centers, and the dynamic quenching is caused by the hole transfer from quantum dots to hole transporting materials molecules. The efficiency of the photoluminescence quenching in CdSe core/shell quantum dots is strongly dependent on the structure of the shells and the HOMO levels of the hole transporting materials. The results are important for understanding the nature of quantum dots surface and the interaction of quantum dots and hole transporting materials.

[Study of applying fluorescence spectrum imaging to quantitative assay of proteins in bio-chip].

In the present work, the amount and the activity of the goat anti-human IgG, to bind the human IgG labelled with fluorescein isothiocyanate (FITC), immobilized on silicon surfaces modified with APTES and APTES-Glu, respectively, were studied using the fluorescence spectrum imaging (FSI), the results of which were compared with that of ellipsometry. It is shown that the amount of the human IgG labeled with FITC on APTES-Glu measured using FSI is 2.8 times higher than that on APTES, which is nearly coincident with the 2.2 times obtained using ellipsometry, showing that the activity of the goat anti-human IgG on APTES-Glu is higher than that on APTES. It is reasoned that the FSI is used in the fluorescence immunoassay the for measurement of quasi-quantification or quantification.

[Surface enhanced Raman spectroscopic study on the gold-labeled protein self-assembled surface].

The human IgG molecules were labeled with 13 nm gold nanoparticles and the complex of the gold-labeled human IgG molecules was immobilized on a silicon surface modified by 3-aminopropyltriethoxysilane and glutaraldehyde. The method increases not only the tightness but also the surface coverage for immobilization of the complex and retains protein configuration well on the silicon surface. The self-assembled complex surface was observed by AFM. The complex aggregated on the silicon surface and the "island" monolayer of the complex was obtained. Meanwhile the SERS spectrum of the complex self-assembled "island" monolayer on silicon surface was presented. In the present paper, the gold labeled human IgG molecules were self-assembled on the silicon surface, SERS spectra of protein were obtained and as SERS active substrates were provided for the study of the protein molecules.

[Distribution Characteristics of Water Temperature and Water Quality of Fuxian Lake During Thermal Stratification Period in Summer].

In order to explore the distribution characteristics and change rule in daytime of the water temperature and water quality of the deep plateau lake Fuxian Lake during the thermal stratification period in summer, a typical point location was selected respectively in the south, middle and north of Fuxian Lake in July 2014 to carry out investigation and observation after stratified sampling at each point location and continuous stratified sampling of the point location in the north during daytime. The result showed that ①The distribution of water temperature of Fuxian Lake in summer had the temperature distribution characteristics of deep lake during stratification period. The segment from the surface to a depth of 15 meters was epilimnion with a range of 25.51-22.81℃. The segment from the depth of 15m to 40m was thermocline with a range of 22.81-14.72℃. The segment below 40m was hypolimnion with a range of 14.72-13.70℃. The max temperature difference between the surface and the lakebed was 11.8℃, which was smaller than that of lakes in temperate zone during the same period. The temperature of the lakebed was about 14℃ which was higher than that of the lakes in temperate zone,which reflected the characteristics of water temperature stratification of the deep plateau lake Fuxian Lake; ②The water temperature stratification determined the characteristics of chemical stratification and the ecological stratification:the pH, DO and conductivity presented the same layered structure as the distribution of water temperature. What is noteworthy was that the DO concentration of the lakebed was as low as 2-3mg·L-1. As an oligotrophic lake, the DO became lower and lower at the lakebed of Fuxian Lake, which indicated that it possibly faced ecological risks. Due to the separation of thermocline, the nutritive salt accumulative effect appeared in the hypolimnion. Chlorophyll a and permanganate index had a corresponding response relation with the water temperature stratification and showed the max value at the upper layer of the lake. ③During the thermal stratification period, the water temperature stratification of Fuxian Lake had a change during daytime. The increased thermal radiation in the noon caused the thermocline to dive, the strength to increase and the depth to narrow, which significantly influenced the dynamic distribution of pH, DO, conductivity and chlorophyll a of the epilimnion and the thermocline. The change rule of TP, TN and permanganate index during the daytime was not significant.