Characterization of Cassava Starch-Stearic Acid Complex Nanoparticles and Stability of Pickering Emulsions Stabilized by It

In order to study the feasibility of applying cassava starch-fatty acid complexes as a Pickering emulsion stabilizer, complex nanoparticles with complexing index (CPI) of 2.74%, 9.17% and 27.66% were prepared by mixing cassava starch paste containing 78.65% amylopectin at 95 ℃ and stearic acid followed by alcohol precipitation. The three complexes had an irregular spherical-like shape under field emission scanning electron microscopy (FESEM), and their average particle sizes, determined by a laser particle size analyzer, were 315.35, 348.19 and 427.60 nm, respectively. The X-ray diffraction pattern of each of the complexes showed two peaks at 13° and 21°, which were characteristics of the V type crystal structure, and the crystal content increase with increasing CPI. Their deconvoluted infrared spectra exhibited changes in short-range ordering at 1 047, 1 022 and 995 cm-1. The contact angle of the particles with the highest CPI was 60.30°. The three complex nanoparticles stabilized Pickering emulsions for more than seven days compared to less than two days with starch nanoparticles. The complex nanoparticles with CPI of 27.66% stabilized emulsions best. The addition of the complex nanoparticles with CPI of 27.66% at levels above 0.1 g/100 mL resulted in the formation of an emulsion with an oil-to-water ratio of 1:9 (V/V). The emulsion with this nanoparticle at 7 g/100 mL exhibited an improved stability for 60 days without creaming or phase separation. Moreover, no significant changes in the droplet size distribution were observed. The emulsion was stable at pH 5.6-9.0 and not affected by NaCl concentration in the range of 0.01-0.1 mol/L. The emulsion maintained its morphology well after being heated to 80 ℃. These results suggest that the complex nanoparticles are a potential Pickering emulsion stabilizer

Methods and clinical development of adenovirus-vectored vaccines against mucosal pathogens

Adenoviruses represent the most widely used viral-vectored platform for vaccine design, showing a great potential in the fight against intracellular infectious diseases to which either there is a lack of effective vaccines or the traditional vaccination strategy is suboptimal. The extensive understanding of the molecular biology of adenoviruses has made the new technologies and reagents available to efficient generation of adenoviral-vectored vaccines for both preclinical and clinical evaluation. The novel adenoviral vectors including nonhuman adenoviral vectors have emerged to be the further improved vectors for vaccine design. In this review, we discuss the latest adenoviral technologies and their utilization in vaccine development. We particularly focus on the application of adenoviral-vectored vaccines in mucosal immunization strategies against mucosal pathogens including Mycobacterium tuberculosis, flu virus, and human immunodeficiency virus

Exploring the influence of cement and cement hydration products on strength and interfacial adhesion in emulsified cold recycled mixture: A molecular dynamics and experimental investigation

This study employed experimental methods and molecular dynamics simulations to investigate how cement and its hydration products affect the mechanical strength and interfacial properties of emulsified cold recycled mixtures (ECRM). The effects of cement hydration product characteristics, such as content, number of nucleation sites, calcium-silicon (Ca/Si) ratio, degree of hydration, and types of hydration products, on the adhesion and water resistance of the cement-emulsified asphalt mortar (CEAM)-aggregate interface, were studied. The findings revealed that increasing the cement content by up to 2% improved the ECRM\u27s mechanical strength. However, the mechanical strength decreased beyond a cement content of 2%. Molecular dynamics simulation demonstrated that augmented cement hydration product content fostered greater adhesion at the interface between CEAM and the aggregate. The presence of an adequate number of nucleation sites was crucial for cement hydration products\u27 effectiveness in strengthening the interface adhesion. Moreover, hydration products with higher degrees of hydration or Ca/Si ratios exhibited a more pronounced impact on enhancing interface adhesion. Furthermore, cement hydration products enhanced the interfacial water resistance of the CEAM-aggregate interface. Nonetheless, the extent of this improvement depended on the interfacial water content. When the interfacial water content was high, the water resistance decreased, and the influence of cement hydration products became negligible. These results highlight the important role of cement and its hydration products in determining the mechanical properties and interfacial characteristics of ECRM and provide insights for optimizing the design and application of such materials in engineering practice

Effects of Different Yeasts on Texture and Flavor of Sweet Potato Bread

In order to investigate the effects of different yeasts on the quality and flavor of sweet potato bread, the rheological properties, color, texture and flavor of sweet potato bread were compared and analyzed. The results showed that different yeasts had significant effects on the color, texture and flavor of sweet potato bread. The results of dynamic rheology showed that the G' and G" of yeast No.4 fermented dough were significantly higher than other groups(P<0.05). The hardness, chewiness, elasticity, cohesion and resilience of commercial yeast fermented bread were significantly lower than those of old yeast fermented bread(P<0.05). The L* value and W value of No.4 old dough yeast fermented bread were significantly higher than others(P<0.05). The results of electronic nose test showed that the main flavor substance of sweet potato bread fermented by 7 different yeasts was inorganic sulfide. A total of 61 volatile compounds were detected by GC-IMS, which were mainly alcohols, ketones and acids, followed by aldehydes, ethers, esters and pyridines. Principal component analysis showed that there were significant differences in volatile flavor compounds of 7 kinds of yeast fermented breads, two principal component contribution rate of 85%, indicating GC-IMS technology could distinguish bread fermented by different yeasts. To sum up, this paper made a detailed comparative analysis of the nature and flavor differences of bread fermented by different yeasts, and would provide a scientific basis for yeast selection in bread production

MOESM1 of HIF-1Îą inhibitor echinomycin reduces acute graft-versus-host disease and preserves graft-versus-leukemia effect

Additional file 1. Additional figures

Integrated Metabolome and Transcriptome Analysis of Gibberellins Mediated the Circadian Rhythm of Leaf Elongation by Regulating Lignin Synthesis in Maize

Plant growth exhibits rhythmic characteristics, and gibberellins (GAs) are involved in regulating cell growth, but it is still unclear how GAs crosstalk with circadian rhythm to regulate cell elongation. The study analyzed growth characteristics of wild-type (WT), zmga3ox and zmga3ox with GA3 seedlings. We integrated metabolomes and transcriptomes to study the interaction between GAs and circadian rhythm in mediating leaf elongation. The rates of leaf growth were higher in WT than zmga3ox, and zmga3ox cell length was shorter when proliferated in darkness than light, and GA3 restored zmga3ox leaf growth. The differentially expressed genes (DEGs) between WT and zmga3ox were mainly enriched in hormone signaling and cell wall synthesis, while DEGs in zmga3ox were restored to WT by GA3. Moreover, the number of circadian DEGs that reached the peak expression in darkness was more than light, and the upregulated circadian DEGs were mainly enriched in cell wall synthesis. The differentially accumulated metabolites (DAMs) were mainly attributed to flavonoids and phenolic acid. Twenty-two DAMs showed rhythmic accumulation, especially enriched in lignin synthesis. The circadian DEGs ZmMYBr41/87 and ZmHB34/70 were identified as regulators of ZmHCT8 and ZmBM1, which were enzymes in lignin synthesis. Furthermore, GAs regulated ZmMYBr41/87 and ZmHB34/70 to modulate lignin biosynthesis for mediating leaf rhythmic growth

Progesterone impairs antigen-non-specific immune protection by CD8 T memory cells via interferon-γ gene hypermethylation

<div><p>Pregnant women and animals have increased susceptibility to a variety of intracellular pathogens including <i>Listeria monocytogenes</i> (LM), which has been associated with significantly increased level of sex hormones such as progesterone. CD8 T memory(Tm) cell-mediated antigen-non-specific IFN-γ responses are critically required in the host defense against LM. However, whether and how increased progesterone during pregnancy modulates CD8 Tm cell-mediated antigen-non-specific IFN-γ production and immune protection against LM remain poorly understood. Here we show in pregnant women that increased serum progesterone levels are associated with DNA hypermethylation of IFN-γ gene promoter region and decreased IFN-γ production in CD8 Tm cells upon antigen-non-specific stimulation <i>ex vivo</i>. Moreover, IFN-γ gene hypermethylation and significantly reduced IFN-γ production post LM infection in antigen-non-specific CD8 Tm cells are also observed in pregnant mice or progesterone treated non-pregnant female mice, which is a reversible phenotype following demethylation treatment. Importantly, antigen-non-specific CD8 Tm cells from progesterone treated mice have impaired anti-LM protection when adoptive transferred in either pregnant wild type mice or IFN-γ-deficient mice, and demethylation treatment rescues the adoptive protection of such CD8 Tm cells. These data demonstrate that increased progesterone impairs immune protective functions of antigen-non-specific CD8 Tm cells via inducing IFN-γ gene hypermethylation. Our findings thus provide insights into a new mechanism through which increased female sex hormone regulate CD8 Tm cell functions during pregnancy.</p></div

Dependence of DNA hypermethylation in progesterone-induced IFN-γ reduction in antigen-non-specific CD8 Tm cells.

<p>Female mice were immunized with rAdHuOVA for 40 days before a 2-week regimen of exogenous progesterone injection, or vehicle as control. Mice were challenged with virulent LM after progesterone administration. In some progesterone injected mice, demethylating agent decitabine (Dec) was administered. Bacterial CFU numbers in the spleen and the liver at 72 hours post infection are shown in (<b>A</b>). At 24 hours post infection, OVA antigen-specific CD8 Tm cells (CD8⁺H2K^bOVA tetramer⁺) from various organs were stained with intracellular IFN-γ. Statistics of frequency (<b>B</b>) and absolute number (<b>C</b>) of IFN-γ-producing H2K^bOVA tetramer⁺ CD8 Tm cells in various organs are shown. (<b>D</b>) Levels of IFN-γ gene methylation in splenic H2K^bOVA tetramer⁺ CD8 Tm cells are shown at various time points before and within 72 hours after infection. In (<b>E</b>) and (<b>F</b>), cells were stimulated <i>ex vivo</i> with innate cytokines IL-12 and IL-18. Statistics of frequency (<b>E</b>) and absolute number (<b>F</b>) of IFN-γ-producing H2K^bOVA tetramer⁺ CD8 Tm cells in various organs are shown. Error bars represent mean±SD. One-way ANOVA and Tukey’s multiple comparisons test was used to compare between multiple groups. * P<0.05; ** P<0.01; *** P<0.001; **** P<0.0001. Data in (A) are representatives of 2 independent experiments with n = 4 per group. Data in (B) and (C) are representatives of 2 independent experiments with n = 3 per group. Data in (D) are representatives of 2 independent experiments with n = 3 per group. Data in (E) and (F) are representatives of 2 independent experiments with n = 3 per group.</p