Effects of Ultrasound-Assisted Soy Lecithin Addition on Rehydration Behavior and Physical Properties of Egg White Protein Powder.

This study investigated the effects of ultrasound-assisted soybean lecithin (SL) on the rehydration behavior and physical properties of egg white protein powder (EWPP) and its ability to enhance the efficacy of EWPP instant solubility. The results of rehydration, including wettability and dispersibility, indicated that ultrasound (200 W)-assisted SL (5 g/L) addition had the shortest wetting time and dispersion time, which were 307.14 ± 7.00 s and 20.95 ± 2.27 s, respectively. In terms of powder properties, the EWPP with added SL had lower lightness, moisture content and bulk density. In addition, the increase in average particle size, net negative charge, free sulfhydryl group content and surface hydrophobicity indicated that ultrasound treatment facilitated the protein structures unfolding and promoted the formation of SL-EWP complexes. Overall, our study provided a new perspective for the food industry regarding using ultrasound technology to produce instant EWPP with higher biological activity and more complete nutritional value.

Mechanism of ultrasound-induced soybean/egg white composite gelation: Gel properties, morphological structure and co-aggregation kinetics.

This study aims to develop ultrasound-assisted acid-induced egg white protein (EWP)-soy protein isolate (SPI) composite gels and to investigate the mechanistic relationship between the co-aggregation behavior of composite proteins and gel properties through aggregation kinetics monitored continuously by turbidity. The results showed that the inclusion of EWP caused the attenuation of gel properties and maximum aggregation (Amax) because EWP could aggregate with SPI at a higher rate (Kapp), which impeded the interaction between SPI and the formation of a continuous gelling network. In the EWP-dominated system, SPI with higher molecular weights also increased the fractal dimension of gels. Ultrasound improved properties of composite gels, especially the SPI-dominated system. After ultrasound treatment, the small, uniform size of co-aggregates and the decrease in potential led to an increase in the aggregation rate and formation of dense particles, consistent with an increase in gelation rate and texture properties. Excessively fast aggregation generated coarse chains and more pores. Still, the exposure of free sulfhydryl groups assisted the gel structure units to form a compact network through disulfide bonding. On the whole, the study could provide theoretical support for a deeper understanding on the interaction mechanism and gelation of composite proteins.

The value of indocyanine green-FLOW800 in microvasculature for predicting cerebral hyperperfusion syndrome in moyamoya disease patients.

Among the notable complications of direct hemodynamic reconstruction for moyamoya disease (MMD) is cerebral hyperperfusion syndrome (CHS). In this study, we evaluated hemodynamic changes in small regional microvasculature (SRMV) around the anastomosis site by using indocyanine green (ICG)-FLOW800 video angiography and verified that it better predicted the onset of CHS. Intraoperative ICG-FLOW800 analysis was performed on 31 patients (36 cerebral hemispheres) with MMD who underwent superficial temporal artery-middle cerebral artery (MCA) bypass grafting at our institution. The regions of interest were established in the SRMV and thicker MCA around the anastomosis. Calculations were made for half-peak to time (TTP1/2), cerebral blood volume (CBV), and cerebral blood flow (CBF). According to the presence or absence of CHS after surgery, CHS and non-CHS groups of patients were separated. The results showed that ΔCBV and ΔCBF were substantially greater in SRMV than in MCA (p < 0.001). Compared with the non-CHS group, ΔCBF and ΔCBV of SRMV and MCA were considerably greater in the CHS group (p < 0.001). ΔCBF and ΔCBV on the ROC curve for both SRMV and MCA had high sensitivity and specificity (SRMV: ΔCBF, AUC = 0.8586; ΔCBV, AUC = 0.8158. MCA: ΔCBF, AUC = 0.7993; ΔCBV, AUC = 0.8684). ICG-FLOW800 video angiography verified the differential hemodynamic changes in the peri-anastomotic MCA and SRMV before and after bypass surgery in patients with MMD.

Substitution of sucrose by erythritol in angel cake: Effect on protein foaming, baking performance and digestion properties.

Sugars played an important role in the processing of products such as cakes, however, their high-calorie character often posed a health risk to consumers. Therefore, this paper aimed to better investigate the effect of sugar substitutes on the improvement of egg white foaming properties and angle cake digestibility characteristics. It was demonstrated that the addition of erythritol improved the surface properties of egg whites, thus enhancing their foaming properties. Particularly, when the erythritol substitution was 50 %, the sugar-egg white complex structure unfolded and had the best foaming capacity. On this basis, the baking performance of angel cakes with sucrose replaced by erythritol was analyzed. When the erythritol substitution was lower than 50 %, the specific volume and the baking loss rate of the cakes were basically unchanged, and the texture and sensory taste of the cakes were all excellent. Finally, the gastrointestinal digestive kinetic analysis suggested that erythritol substitution for sucrose was beneficial for reducing blood glucose levels in vivo. Furthermore, for the MgCl2-based samples, both the degree of protein destruction after digestion was weakened and the glucose-lowering effect was better exerted. Overall, this study provided a new theoretical basis for the low-calorie sugar-substituted health food products development in the future.

Magnesium ions regulated ovalbumin-lysozyme heteroprotein complex: Aggregation kinetics, thermodynamics and morphologic structure.

This study aims to investigate the mechanism of magnesium ions regulated ovalbumin-lysozyme (OVA-LYS) heteroprotein aggregation behavior via aggregation kinetics model, exploring the relationship between differential aggregation behavior and protein molecular structure, intermolecular interactions and thermal stability. Results showed that the aggregation rate (kapp) and maximum absorbance (Amax) of the OVA-LYS heteroprotein complex were located between OVA and LYS. Meanwhile, the thermal denaturation temperature (Td) and denaturation enthalpy (ΔH) were between the values of OVA and LYS as well. Compared with OVA, the thermal stability of the OVA-LYS heteroprotein complex increased owing to the electrostatic interactions between OVA and LYS, resulting in slower aggregation rate and lower aggregation degree. Molecular dynamics simulations revealed the molecular conformational changes during OVA-LYS binary protein binding and the stability of the complex conformation. Moreover, MgCl2 weakened the OVA-LYS interactions through Debye shielding while increasing thermal stability, allowing the two proteins to aggregate into amorphous precipitates rather than spherical coacervates. Overall, this study provides information to further understand the regulation mechanism of proteins differential aggregation behavior by ions.

Tailoring a novel ovalbumin emulsion gel for stability improvement and functional properties enhancement: Effect of oil phase structure changes by beeswax.

This study aimed to form a novel emulsion gel (EG) through structured oil phase of natural component beeswax (BW), together with ovalbumin (OVA), and to investigate the mechanism of its formation and stabilization in terms of microstructure and processing properties. Confocal laser scanning microscopy (CLSM) demonstrated that the EG formed a continuous double network structure since the superior crystallinity of the oil phase was given by BW. Fourier transform infrared spectroscopy (FT-IR) illustrated that the acylation of the phenolic hydroxyl group in BW with an amide bond in OVA, increased the hydrogen bonding of EG. Furthermore, the immobilization of the oil phase results in better thermal and freeze-thaw stability of EG. Finally, EG was used as a curcumin delivery system, and the presence of BW significantly improved its adaptability to multiple environmental factors. In summary, our study would provide valuable ideas for developing the design of finely structured functional food.

Exploring of the molecular mechanism of rhinitis via bioinformatics methods.

The aim of this study was to analyze gene expression profiles for exploring the function and regulatory network of differentially expressed genes (DEGs) in pathogenesis of rhinitis by a bioinformatics method. The gene expression profile of GSE43523 was downloaded from the Gene Expression Omnibus database. The dataset contained 7 seasonal allergic rhinitis samples and 5 non­allergic normal samples. DEGs between rhinitis samples and normal samples were identified via the limma package of R. The webGestal database was used to identify enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the DEGs. The differentially co­expressed pairs of the DEGs were identified via the DCGL package in R, and the differential co­expression network was constructed based on these pairs. A protein­protein interaction (PPI) network of the DEGs was constructed based on the Search Tool for the Retrieval of Interacting Genes database. A total of 263 DEGs were identified in rhinitis samples compared with normal samples, including 125 downregulated ones and 138 upregulated ones. The DEGs were enriched in 7 KEGG pathways. 308 differential co­expression gene pairs were obtained. A differential co­expression network was constructed, containing 212 nodes. In total, 148 PPI pairs of the DEGs were identified, and a PPI network was constructed based on these pairs. Bioinformatics methods could help us identify significant genes and pathways related to the pathogenesis of rhinitis. Steroid biosynthesis pathway and metabolic pathways might play important roles in the development of allergic rhinitis (AR). Genes such as CDC42 effector protein 5, solute carrier family 39 member A11 and PR/SET domain 10 might be also associated with the pathogenesis of AR, which provided references for the molecular mechanisms of AR.

Association between interferon gamma 13-CA-repeats polymorphism and metastasis of nasopharyngeal carcinoma in a population of Northern China.

Interferon Gamma gamma (IFN-γ) 13-CA-repeats polymorphism is associated with a variety of diseases; here we report its association with nasopharyngeal carcinoma (NPC) metastasis in a retrospective analysis of a cohort of 220 NPC patients in the northern China. The results showed that the distributions of CA13-/CA13-genotypes were significantly higher in the patients with lymph node metastasis (P<0.05) and distant metastasis (P<0.001); there was a significant difference between NPC patients with stage I+II and those with stage III+IV regarding CA13+/CA13-(P<0.001) and CA13-/CA13- genotypes (P<0.001); further analysis showed a more pronounced difference between NPC patients with stage I+II+III and those with stage IV for CA13-/CA13-genotype (P<0.001), whereas no difference was found for CA13+/CA13- genotype (P=0.790). Thus, we identify that IFN-γ 13-CA-repeat polymorphism is significantly associated with the metastasis of NPC, which may provide insights into its prognosis and individualized treatment.

[Effects and mechanism on removing organics and reduction of membrane fouling using granular macro-porous anion exchange resin in drinking water treatment].

A granular macro-porous anion exchange resin combined with coagulation was used as pretreatment of microfiltration membrane, and their effects and mechanism on removing organics and reduction of membrane fouling were evaluated. The results showed that resin could be effective in removing organics with medium and small molecular weight ( Mr) but ineffective in removing organics with large Mr, while couagulation could significantly remove organics with large Mr, with a limited removal for organics with medium and small Mr. Using resin alone as pretreatment could be effective in removal of organics but limited in reduction of membrane fouling. With combination of coagulation and resin as pretreatment of microfiltration, not only organics could be removed effectively, but also membrane fouling could be reduced.

Acylated iridoids from the roots of Valeriana officinalis var. latifolia.

Phytochemical investigation of the roots of Valeriana officinalis var. latifolia resulted in the isolation and characterization of six new acylated iridoids, (5S,7S,8S,9S)-7-hydroxy-8-isovaleroyloxy-Δ4,¹¹-dihyronepetalactone (1), (5S,7S,8S,9S)-7-hydroxy-10-isovaleroyloxy-Δ4,¹¹-dihyronepetalactone (2), (5S,8S,9S)-10-isovaleroyloxy-Δ4,¹¹-dihyronepetalactone (3), (5S,6S,8S,9R)-6-isovaleroyloxy-Δ4,¹¹-1,3-diol (4), (5S,6S,8S,9R)-1,3-isovaleroxy-Δ4,11-1,3-diol (5), and (5S,6S,8S,9R)-3-isovaleroxy-6-isovaleroyloxy-Δ4,¹¹-1,3-diol (6). Their structures were determined mainly by 1D and 2D NMR spectroscopic techniques. We also report herein for the first time the single crystal X-ray structure of compound 1. In addition, the cytotoxic activities of compounds 1-6 were evaluated against A549 (human lung adenocarcinoma), HCT116 (human colon carcinoma), SK-BR-3 (human breast carcinoma), and HepG2 (human hepatoma) cell lines. Compound 6 showed weak cell growth inhibition of A549, HCT116, SK-BR-3, and HepG2 cells.

Identification of an aminoacridine derivative that binds to RNA tetraloops.

RNA folds into diverse structures that form unique targets for small molecules and thus provide significant potential for controlling biological processes involving RNA with small-molecule ligands. We are investigating molecular recognition of tetraloop RNA by small molecules. RNA tetraloops are four-nucleotide stem loops with unusual stability that are involved in biological processes involving RNA by forming binding sites for proteins and other RNAs. We have sequentially used the docking programs DOCK and AutoDock to screen 1990 small molecules in the NCI diversity set to identify molecules selective for RNA tetraloops over double-stranded RNA. The compounds predicted to bind to tetraloop RNA were evaluated for binding RNA tetraloops using 1H NMR spectroscopy and fluorescence techniques. An aminoacridine derivative (AD2) was identified that binds to a GAAA tetraloop in a 2:1 ratio with dissociation constants of 1.0 and 4.0 microM. AD2 binds with approximately 20-fold and 9-fold higher affinity to tetraloop RNA than to double- and single-stranded RNAs, respectively.

Binding of an aminoacridine derivative to a GAAA RNA tetraloop.

RNA tetraloops are common secondary structural motifs in many RNAs, especially ribosomal RNAs. There are few studies of small molecule recognition of RNA tetraloops although tetraloops are known to interact with RNA receptors and proteins, and to form nucleation sites for RNA folding. In this paper, we investigate the binding of neomycin, kanamycin, 2,4-diaminoquinazoline, quinacrine, and an aminoacridine derivative (AD1) to a GAAA tetraloop using fluorescence spectroscopy. We have found that AD1 and quinacrine bind to the GAAA tetraloop with the highest affinity of the molecules examined. The equilibrium dissociation constant of the AD1-GAAA tetraloop complex was determined to be 1.6 microM. RNase I and lead acetate footprinting experiments suggested that AD1 binds to the junction between the loop and stem of the GAAA tetraloop.