Effect of Heat Transfer Medium and Rate on Freezing Characteristics, Color, and Cell Structure of Chestnut Kernels

This paper compared the effects of air and nitrogen on the freezing characteristics, color, and cell structures of chestnut kernels at different rates of heat transfer and adopted liquid nitrogen spray quick-freezing (NF−40 °C/−60 °C/−80 °C/−100 °C) and still air freezing (AF−20 °C/−40 °C) as the freezing methods. The ratio of heat transfer coefficients in N2 groups was two times as high as those in air groups, and NF−100 °C and NF−80 °C showed better freezing characteristics, good protection for cytoskeletons, and the color was similar to those of the fresh group. Taking both Multivariate Analysis of Variance (Principal Components Analysis and Cluster Analysis) and economic factors, NF−80 °C can be used as a suitable method for chestnut kernel freezing. When the ambient freezing temperature was lower than Tg, both NF and AF treatment groups presented poor quality. The rate and medium of heat transfer jointly influenced the freezing characteristics and quality. The former had a greater effect than the latter, however.

Penta-O-galloyl-β-d-glucose inhibits the formation of advanced glycation end-products (AGEs): A mechanistic investigation

Penta-O-galloyl-β-d-glucose (PGG) was prepared from tannic acid methanolysis products based on HSCCC, and its protective effects and mechanism on the glucose-induced glycation were investigated for the first time. PGG was confirmed to exhibit strong anti-AGEs effects in bovine serum albumin (BSA)-glucose (Glu) and BSA-methylglyoxal (MGO) glycation systems. It was showed that PGG could inhibit the AGEs formation by blocking glycated intermediates (fructosamine and α-dicarbonyl compounds), eliminating radicals, and chelating metal-ions. In-depth mechanism analysis proved that PGG could prevent BSA from glycation by hindering the accumulation of amyloid fibrils, stabilizing the BSA secondary structures, and binding the partial glycation sites. Furthermore, PGG exhibited a prominent trapping capacities on the reactive intermediate MGO by generating PGG-mono-MGO adduct. This research indicated that PGG could be an effective agent to block Glu/MGO-triggered glycation and offered new insights into PGG as a functional ingredient in food materials for preventing diabetic syndrome.

Hemicelluloses-based sprayable and biodegradable pesticide mulch films for Chinese cabbage growth

In this study, one high-performance hemicelluloses (HC)-based sprayable and biodegradable pesticide mulch film was developed. Firstly, HC was transesterified with vinyl acetate (VA) to improve its solubility and film-forming ability. Then abamectin (ABA) was encapsulated by β-cyclodextrin (β-CD) to endow mulch film persistent anti-pesticide activity. After that, sodium alginate (SA) and gelatin were added to develop the mechanical performances of the mulch film. As a result, the obtained mulch film showed good characteristics, with optimum mechanical strength, elongation at break, water vapor permeability (WVP), swelling ratio (SR), and weight loss (biodegradability) of 7.9 ± 0.3 MPa, 43.6 ± 2.0 %, 2.1 ± 0.1 × 10^-11 g mm m^-2 s^-1 kPa^-1, 73.8 ± 2.0 %, and 69.3 %, respectively. After covering with mulch film, the soil moisture and temperature were developed to 90.8 % and 19.3 ± 0.2 °C, respectively, which could facilitate Chinese cabbage growth, with optimum germination rate of 98.6 ± 6.4 %.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Functional analysis of the dehydratase domains of the PUFA synthase from Emiliania huxleyi in Escherichia coli and Arabidopsis thaliana

BACKGROUND

Polyunsaturated fatty acid (PUFA) synthase is a multi-domain mega-enzyme that effectively synthesizes a series of PUFAs in marine microorganisms. The dehydratase (DH) domain of a PUFA synthase plays a crucial role in double bond positioning in fatty acids. Sequencing results of the coccolithophore Emiliania huxleyi (E. huxleyi, Eh) indicated that this species contains a PUFA synthase with multiple DH domains. Therefore, the current study, sought to define the functions of these DH domains (EhDHs), by cloning and overexpressing the genes encoding FabA-like EhDHs in Escherichia coli (E. coli) and Arabidopsis thaliana (A. thaliana).

RESULTS

A complementation test showed that the two FabA-like DH domains could restore DH function in a temperature-sensitive (Ts) mutant. Meanwhile, overexpression of FabA-like EhDH₁ and EhDH₂ domains increased the production of unsaturated fatty acids (UFAs) in recombinant E. coli by 43.5-32.9%, respectively. Site-directed mutagenesis analysis confirmed the authenticity of active-site residues in these domains. Moreover, the expression of tandem EhDH₁-DH₂ in A. thaliana altered the fatty acids content, seed weight, and germination rate.

CONCLUSIONS

The two FabA-like DH domains in the E. huxleyi PUFA synthase function as 3-hydroxyacyl-acyl carrier protein dehydratase in E. coli. The expression of these domains in E. coli and A. thaliana can alter the fatty acid profile in E. coli and increase the seed lipid content and germination rate in A. thaliana. Hence, introduction of DH domains controlling the dehydration process of fatty acid biosynthesis in plants might offer a new strategy to increase oil production in oilseed plants.

Physicochemical properties of dietary fiber of bergamot and its effect on diabetic mice

Bergamot (Citrus medica L. var. sarcodactylis) contains different bioactive compounds, and their effects remain unclear. Therefore, the structural and bio-function of bergamot dietary fiber were investigated. A sequential extraction procedure was utilized to obtain soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) from bergamot. The main monosaccharide in SDF and IDF is arabinose. SDF had a porous structure, which enhanced the water and oil holding capacity, as well as the cholesterol and glucose adsorption capacity, which was superior to that of IDF. In db/db diabetic mice, SDF and IDF regulated glucose tolerance and controlled blood glucose levels. Reduction of serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol in SDF and IDF could be observed. In summary, SDF and IDF from bergamot effectively promoted health in patients with diabetes.

Change in membrane fluidity induced by polyphenols is highly dependent on the position and number of galloyl groups

The cell membrane fluidity was very important in adipogenesis and galloyl groups on polyphenolic structures could enhance their antiadipogenic activity. However, the effect of polyphenols on membrane fluidity and the role of galloyl groups in fluidity changes remain unclear. Therefore, the present study chose structurally different polyphenols to compare their effects on the membrane morphology and fluidity of 3T3-L1 preadipocytes, and then the reasons behind the changes of membrane fluidity induced by galloylated polyphenols were explored from structural and molecular insights using liposome model and molecular dynamic simulation technology. Our results indicated that galloylated polyphenols could significantly change 3T3-L1 cell membrane morphology and decrease membrane fluidity, while non-galloylated ones could not. The membrane interference effect of polyphenols was enhanced as the number of galloyl groups increased. Morever, the decrease in membrane fluidity induced by galloylated polyphenols was due to the disturbance of polyphenols on lipid alkyl chains in the cell membrane. Galloylated polyphenols could not only locate in the polar head, but also insert into hydrophobic center of lipid bilayer to interfere with the lipid alkyl chains arrangement, thus decreasing the membrane fluidity and showing strong affinity for the membrane. In addition, differences in position of galloyl groups in polyphenols induced distinct effect on cell membranes interactions, thus affecting the binding manner and bioactivity. The results expanded the understanding on the strong antiadipogenic activity of galloylated polyphenols through the aspect of their effects on cell membrane by both experimental and theoretically simulated ways.

Microbial Interaction between Lactiplantibacillus plantarum and Saccharomyces cerevisiae: Transcriptome Level Mechanism of Cell-Cell Antagonism

Lactiplantibacillus plantarum and Saccharomyces cerevisiae are frequently co-isolated in food, although playing different roles. This study aimed at investigating the microbial interaction between L. plantarum and S. cerevisiae, especially cell-cell direct interaction and their mechanism. Cell-cell and supernatant-cell coculture models were set up, with CFU counting, OD₆₀₀ measurement, optical and atomic force microscopy performed to examine the growth and morphology of L. plantarum and S. cerevisiae cells. In cell-cell coculture model, L. plantarum cells inhibited S. cerevisiae growth (inhibition rate ~80%) with its own growth pattern unaffected. Cell-cell aggregation happened during coculture with surface roughness changed and partial S. cerevisiae cell lysis. Mature (24 h) L. plantarum cell-free culture supernatant showed inhibition (35%-75%) on S. cerevisiae growth independent of pH level, while supernatant from L. plantarum-S. cerevisiae coculture showed relatively stronger inhibition. Upon transcriptomics analysis, hypothesis on the mechanism of microbial interaction between L. plantarum and S. cerevisiae was demonstrated. When L. plantarum cell density reached threshold at 24 h, all genes in lamBDCA quorum sensing (QS) system was upregulated to potentially increase adhesion capability, leading to the aggregation to S. cerevisiae cell. The downregulation of whole basic physiological activity from DNA to RNA to protein, cell cycle, meiosis, and mitogen-activated protein kinase (MAPK) signaling pathways, as well as growth maintenance essential genes ari1, skg6, and kex2/gas1 might induce the decreased growth and proliferation rate and partial death of S. cerevisiae cells in coculture. IMPORTANCE L. plantarum and S. cerevisiae are frequently co-isolated in food, although playing different roles. The co-existence of L. plantarum and S. cerevisiae could result in variable effects, raising economic benefits and safety concerns in food industry. Previous research has reported the microbial interaction between L. plantarum and S. cerevisiae mainly rely on the signaling through extracellular metabolites. However, cell-cell aggregation has been observed with mechanism remain unknown. In the current study, the microbial interaction between L. plantarum and S. cerevisiae was investigated with emphasis on cell-cell direct interaction and further in-depth transcriptome level study showed the key role of lamBDCA quorum sensing system in L. plantarum. The results yield from this study demonstrated the antagonistic effect between L. plantarum and S. cerevisiae.

Effect of replacing inorganic minerals with small peptide chelated minerals on production performance, some biochemical parameters and antioxidant status in broiler chickens

Due to the low bio-availability of inorganic trace minerals, its application in poultry production has been causing many problems such as environment pollution and waste of resources. The current study was designed to evaluate if replacing inorganic trace minerals (ITM) with small peptide chelate trace minerals (SPM) affects production performance, some biochemical parameters and antioxidant status, tibia mineral deposition, and fecal mineral content in 817 white-feathered broilers. A total of 432 broilers (21-day-old) were randomly divided into four groups with six replicates of 18 chicks each. The four groups included inorganic trace minerals group (addition of 1,000 mg/kg ITM; common practice by commercial poultry farms), three organic trace minerals groups with supplementation of 150, 300, and 500 mg/kg SPM, respectively. The experiment lasted for 30 days. The results showed that there was no significant difference in growth performance and slaughter performance among the four groups (p > 0.05). Total cholesterol in the SPM group was significantly lower than those in the ITM groups (p < 0.01). Compared with the ITM group, the serum urea nitrogen in 150 and 300 mg/kg SPM groups decreased significantly (p < 0.01). Among all SPM treatments, 300 mg/kg SPM groups had the highest serum glutathione peroxidase (GSH-Px) activity (p < 0.01). The activity of copper and zinc superoxide dismutase (Cu/Zn SOD) of liver in ITM group was the lowest among the four groups (p < 0.01). The catalase (CAT) activity of liver in the 150 mg/kg SPM group was significantly higher than the ITM group and 300 mg/kg SPM group (p < 0.05). Compared to the ITM group, the iron content of the tibia was significantly increased in 300 mg/kg SPM group (p < 0.05) and 500 mg/kg SPM group (p < 0.01). Compared to the ITM group, dietary supplementation with SPM significantly reduced fecal content of zinc and manganese (p < 0.01). The 150 mg/kg SPM and 300 mg/kg SPM group had significantly reduced content of iron (p < 0.05). This study demonstrated that replacing inorganic minerals with low doses of SPM (300 and 500 mg/kg) did not negatively affect growth and slaughter performance, as well as the antioxidant status of broiler chickens. In addition, SPM can also promote mineral content in the tibia and reduce mineral content in the feces.

Development of functional hydroxyethyl cellulose-based composite films for food packaging applications

Cellulose-based functional composite films can be a good substitute for conventional plastic packaging to ensure food safety. In this study, the semi-transparent, mechanical strengthened, UV-shielding, antibacterial and biocompatible films were developed from hydroxyethyl cellulose Polyvinyl alcohol (PVA) and ε-polylysine (ε-PL) were respectively used as reinforcing agent and antibacterial agent, and chemical cross-linking among these three components were constructed using epichlorohydrin The maximum tensile strength and elongation at break were 95.9 ± 4.1 MPa and 148.8 ± 2.6%, respectively. TG-FTIR and XRD analyses indicated that chemical structure of the composite films could be well controlled by varying component proportion. From UV-Vis analysis, the optimum values of the percentage of blocking from UV-A and UV-B and ultraviolet protection factor values were 98.35%, 99.99% and 60.25, respectively. Additionally, the composite films exhibited good water vapor permeability, swelling behavior, antibacterial activity and biocompatibility. In terms of these properties, the shelf life of grapes could be extended to 6 days after packing with the composite film.

Effects of Dietary Essential Oils Supplementation on Egg Quality, Biochemical Parameters, and Gut Microbiota of Late-Laying Hens

The objective of this study was to explore the effects of adding essential oils (EO) to diets on egg quality, biochemical parameters and intestinal flora of late laying hens. The number of 252 Dawu Golden Phoenix laying hens (55 weeks old) were randomly sorted into two groups: the control group (CG) fed a basal diet and the EO group fed a basal diet with 300 mg/kg of essential oils. The average egg weight, feed-to-egg ratio, and egg production rate were determined every week. The trial started at week 55 and lasted for 8 weeks. During the experiment’s last week, 36 eggs out of each group were chosen at random to test. In our study, dietary supplementation with EO considerably decreased the egg breaking rate (p = 0.01) and increased the shell-breaking strength (p = 0.04). The treatment group’s alanine aminotransferase (ALT) levels were considerably lower than those of the control group (p = 0.03). The EO group had substantially higher total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) (p = 0.04 and p =0.03, respectively). However, there were no differences in alpha diversity indicators between the two groups. It is worth noting that Firmicutes were increased considerably (p < 0.05), while Spirochaetota and Proteobacteria were significantly reduced in the EO group. At genus levels, the EO supplementation increased the relative abundance of Intestinimonas (p < 0.05) and Megamonas (p < 0.01). In conclusion, a dietary supplementation of 300 mg/kg EO can improve the production performance of laying hens and the egg quality. It can also regulate the abundance of cecal flora and serum biochemical indicators.

Effects of fulvic acid addition on laying performance, biochemical indices, and gut microbiota of aged hens

The purpose of this study was to appraise the effect of fulvic acid on production, biochemical indices, and gut microbiota of laying hens. A total of 252 Dawu Golden Phoenix laying hens (55-week-old) were allotted to two treatments randomly, each with six replicates and 21 hens per replicate, including the control group (CG) and fulvic acid (500 mg/kg) group (FA). The trial period was 8 weeks. Adding FA raised egg weight (P = 0.03), shell-breaking strength (P = 0.03), and reduced egg breaking rate (P < 0.01), compared with CG. There was no difference in eggshell thickness and egg shape index between the two treatments; however, the FA group increased egg production by 1.45% and reduced the feed-to-egg ratio by 0.09. Moreover, dietary FA decreased the aspartate aminotransferase levels in serum (P = 0.04), and glutathione peroxidase and total antioxidant capacity were increased (P = 0.02 and 0.04, respectively). Despite this, the two groups had no differences in the alpha diversity indices (PD_whole trees, Shannon, Ace, Simpson, Chao1, and goods_coverage). Obviously, at the phylum level, the abundances of Firmicutes were improved (P < 0.01), Actinobacteriota (P < 0.01), and Proteobacteria (P < 0.01) were reduced by dietary FA. Supplementation with FA could improve the abundances of Megamonas (P < 0.01) and reduce Enterobacter (P < 0.01) at the genus level. To sum up, this study showed the addition of 500 mg/kg FA may boost production and egg quality and modulate the cecal microflora abundance and serum biochemical indices of laying hens.

Effect of various drying methods on the physicochemical characterizations, antioxidant activities and hypoglycemic activities of lychee (Litchi chinensis Sonn.) pulp polysaccharides

Suitable drying method is critical for the preservation of physicochemical and pharmacological quality of lychee pulp polysaccharides (LPPs). In current work, the effects of five drying methods, i.e. air drying (A), infrared drying (I), heat pump drying (H), vacuum freeze drying (F) and freeze vacuum drying combined with heat pump drying (FH) on the physicochemical characterizations, antioxidant activities and hypoglycemic activities of LPPs were explored. Results showed all five drying methods led to thermal aggregation of LPPs and the stronger the thermal effect induced by drying, the more serious the aggregations were. Additionally, the thermal aggregation significantly affected the composition, structure and biological activity of LPPs. Less thermal aggregation was observed in LPPF and LPPFH, which exhibited stronger oxygen, DPPH and ABTS radical scavenging activities, higher ferric-reducing power and better α-glycosidase and α-amylase inhibition activities, resulting from their higher contents of neutral sugar, protein and uronic acid and lower molecular weight than LPPA and LPPI. Besides, FH consumed about half drying time and one fifth energy of F. Therefore, from industrial perspective, FH is a promising alternative to F for producing LPPs by comprehensively considering physicochemical characterizations, bioactivity as well as energy consumption.

Characteristics of Radiation-Related Intracranial Aneurysms: A Multicenter Retrospective Study

BACKGROUND AND PURPOSE

Intracranial aneurysms, a rare complication of radiation therapy, have been reported mainly in case reports or case series. We performed a multicenter, retrospective cohort study to investigate the characteristics of radiation-induced intracranial aneurysms.

MATERIALS AND METHODS

Data on 2641 patients with intracranial aneurysms were retrospectively collected from 3 hospitals between January 2005 and June 2014. An additional 1519 patients were recruited from a single center between July 2014 and March 2020. Aneurysms in patients with a history of radiation therapy for at least 6 months were defined as radiation-related aneurysms. Patients' demographic profiles, clinical characteristics, and aneurysm parameters detected on CTA were compared between radiation-related and control groups.

RESULTS

Of the 4160 patients, the average age was 57.9 (SD, 13.5) years, 2406 (57.8%) were women, 477 (11.5%) had multiple aneurysms, 3009 (72.3%) had SAH, and 34 (0.8%) had radiation-related aneurysms. The male-to-female ratio in the radiation-related group was significantly higher than that in the control group (2.4:1 versus 0.72:1, P = .001). The mean age of the radiation-related group was significantly younger than in the control group (51.4 [SD, 15.0] years versus 58.2 [SD, 13.5] years, P = .003). More patients in the radiation-related group presented with SAH than in the control group (without age and sex matching, 88.2% versus 72.2%, P = .037; with age and sex matching, 88.2% versus 58.8%, P = .006). Of the 4813 intracranial aneurysms, only 43 (0.9%) aneurysms were categorized as in the radiation-related group, whereas 4770 (99.1%) aneurysms constituted the control group. Compared with the control group, there was a significantly higher proportion of sidewall aneurysms (46.5% versus 32.3%, P = .048) and a predilection for aneurysms involving the ICA and posterior circulation arteries (72.1% versus 52.2%, P = .046) in the radiation-related group.

CONCLUSIONS

Compared with the control group, radiation-related aneurysms are more prone to occur in men and young patients, with a higher percentage of sidewall aneurysms located in the ICA and posterior circulation arteries. Furthermore, SAH is highly prevalent in patients with radiation-induced aneurysms, indicating that dedicated screening for aneurysms after radiation therapy is necessary, but further studies are needed to determine when and how to screen.

Debate: Could the litchi pericarp oligomeric procyanidins bioconverted by Lactobacillus plantarum increase the inhibitory capacity on advanced glycation end products?

Lactic acid bacteria (LAB) have already been used as fermentation strains to enhance the antioxidant capacity of polyphenols. Antioxidant capacity is one of the most important factors to inhibit advanced glycation end product (AGE) formation and could LAB increase the inhibitory capacity of procyanidins on AGEs formation? It was surprising that opposite results were obtained both in simulated food processing and gastrointestinal digestion systems. After incubation with Lactobacillus plantarum (L. plantarum), litchi pericarp oligomeric procyanidins (LPOPCs) were bioconverted to several phenolic acids, which increased the antioxidant activity as expected. However, antiglycation ability and trapping carbonyl compounds capacity both weakened and it might be the primary reason for decreasing the inhibitory effect on AGE formation. Furthermore, it was found that LPOPCs incubated with L. plantarum inhibited the activity of digestive enzymes and thus decreased the digestibility of glycated protein. Our study systematically proposed for the first time that procyanidins bioconversion is an effective means to improve the antioxidant activity but has no remarkable promoting effect on AGEs inhibition.