Theoretical study on the hydrogen distribution and diffusion at the PuO2/α-Pu2O3 interface.

The interface is a region in the crystal that significantly changes various characteristics. There must be an interface between oxides of different valence states in the surface oxide layer of plutonium. In this work, a first principles approach based on DFT was used to study the hydrogen distribution and diffusion at the PuO2/α-Pu2O3 interface systematically. Our research reveals that at the interface, hydrogen can be captured by the O atoms of PuO2 and by the oxygen vacancies (OVs) of α-Pu2O3, and the capture of OVs is more energetically advantageous. On the PuO2 side, the cost of H atom diffusion towards the interface gradually increases. On the α-Pu2O3 side, the cost of H atoms diffusing inward from the interface gradually increases. OVs that already contain H atoms are more conducive to capturing H atoms. The formation of the interface has little effect on the hydrogen capture ability of O in PuO2, but it will reduce the capture ability of OVs in α-Pu2O3. Overall, the formation of interfaces has no disruptive impact on the behavior of hydrogen in the two plutonium oxides. This is closely related to the fact that α-Pu2O3 originates from PuO2 under anaerobic conditions. The difference in hydrogen behavior comes from the changes in the atomic environment and ion valence state caused by the OVs. This work supports further understanding of the behavior of hydrogen in plutonium oxides and provides a reference for further research on plutonium corrosion prevention.

Adsorption, dissociation and diffusion behavior of H2O on the PuO2(111) surface from DFT + U-D3: the role of hydrogen bonding.

The interaction between H2O and plutonium oxide is an essential aspect of researching plutonium corrosion. We systematically studied the adsorption, dissociation, and diffusion of H2O molecules on the PuO2(111) surface with the DFT + U-D3 scheme. We find that the top of the Pu atom is the most stable adsorption site for H2O molecules on the PuO2(111) surface. When multiple H2O molecules are adsorbed, hydrogen bonding between molecules can increase the average adsorption energy. H2O molecules will dissociate into H atoms and O-H groups under certain conditions. We have paid special attention to the role of hydrogen bonds between H2O molecules. When the coverage of H2O molecules is low, hydrogen bonds can significantly promote the adsorption and dissociation of H2O molecules. And H2O tends to exist on the surface of plutonium oxide in dissociated and molecular mixed states. The H atoms produced by the dissociation of H2O molecules are not easily diffused, which may be related to the hydrogen bonding between O-H groups. This work has important theoretical significance for deepening the understanding of the corrosion mechanism of plutonium.

Endogenous chitinase might lead to differences in growth performance and intestinal health of piglets fed different levels of black soldier fly larva meal.

This study aimed to investigate the effects of different levels of black soldier fly (BSF) replacing soybean meal (SBM) in diets on the performance and health condition of piglets. A total of 180 weaned piglets were allocated into 5 treatments: BSF0 (corn-soybean meal basal diet), BSF25 (BSF replacing 25% SBM), BSF50 (BSF replacing 50% SBM), BSF75 (BSF replacing 75% SBM) and BSF100 (BSF replacing 100% SBM). During the whole period, in comparison with BSF0, average daily gain (ADG) and average daily feed intake increased in the BSF25 and BSF50 groups, whereas ADG decreased in the BSF75 and BSF100 groups (P < 0.05). The result of quadratic fitting curve showed that piglets exhibited the highest ADG when BSF replaced around 20% SBM. Compared with BSF0, organic matter and dry matter digestibility improved in the BSF25 group, whereas ether extract digestibility decreased in the BSF100 group (P < 0.05). In comparison with BSF0, piglets from the BSF25 group showed a higher duodenal ratio of villus height to crypt depth, increased jejunal sucrase activity, serum neuropeptide Y and ghrelin levels, elevated ileal immunoglobulin (Ig) A, IgG and IgM contents and a lower leptin level, and piglets from the BSF100 group exhibited an increased relative weight of kidney (P < 0.05). However, no significant differences were observed in the expression level of tight junction proteins and chitin-degrading enzyme. Additionally, compared with BSF0, the abundance of short chain fatty acid producing bacteria such as Ruminococcaceae, Faecalibacterium and Butyricicoccus increased, and potential pathogenic bacteria decreased in piglets from the BSF25 group, whereas piglets from the BSF100 group had a greater abundance of harmful bacteria. In conclusion, BSF replacing 25% SBM in diets could improve digestive parameters, immune function and intestinal microbiota, and thus improved growth performance of piglets. However, BSF replacing 100% SBM showed an adverse effect on piglet performance, and the reason might be related to the limited amount of chitin-degrading enzyme.

Supplementation with alpha-glycerol monolaurate during late gestation and lactation enhances sow performance, ameliorates milk composition, and improves growth of suckling piglets.

BACKGROUND: Physiological changes during lactation cause oxidative stress in sows, reduce immunity, and hamper the growth capacity of piglets. Alpha-glycerol monolaurate (α-GML) has potential for enhancing the antimicrobial activity of sows and the growth of suckling piglets. METHODS: Eighty sows were allocated randomly to four groups: basal diet and basal diets supplemented with 500, 1000, or 2000 mg/kg α-GML. The experiment started on d 85 of gestation and lasted until piglets were weaned on d 21 of lactation. The number of live-born piglets was standardized to 12 ± 1 per sow on day of parturition. On d 0 and 21 of lactation, body weight of piglets was measured and milk samples were obtained from sows, and serum samples and feces from piglets were obtained on d 21. RESULTS: Feed intake, backfat loss, and weaning estrus interval did not differ among the four groups of sows. Maternal α-GML supplementation increased (P < 0.05) the body weight of piglets at weaning and the apparent total tract digestibility of crude fat of sows. The immunoglobulin A and immunoglobulin G levels were greater (P < 0.05) in a quadratic manner in the milk of sows as dietary α-GML increased. Concerning fatty acid profile, C12:0, C15:0, C17:0, C18:2n6c, C18:3n3, C24:0, and C22:6n3 were higher (P < 0.05) in linear and quadratic manners in colostrum of sows-fed α-GML diets compared with the control sows. There was lower (P < 0.05) n-6:n-3 polyunsaturated fatty acid ratio in milk than in the control sows. Maternal α-GML increased the abundance of Firmicutes (P < 0.05) and decreased the abundance of Proteobacteria (P < 0.05) of piglet fecal microbiota. CONCLUSIONS: Dietary supplementation with α-GML improved milk immunoglobulins and altered fatty acids of sows, thereby improving the health of piglets.

First-Principles Study on the Adsorption Behavior of O2 on the Surface of Plutonium Gallium System.

To deeply understand the adsorption process of oxygen on the surface of a plutonium gallium system and to reveal the chemical reaction mechanism at the initial stage of oxidative corrosion on the surface of plutonium gallium alloy at a theoretical level, the adsorption behavior of oxygen molecules on the surface of a plutonium gallium system was investigated by a first-principles approach based on density flooding theory. The results show that the molecular bond length increases and finally breaks when the surface oxygen molecule is adsorbed on the surface of plutonium gallium system and dissociates into two atomic states. The most likely adsorption position of oxygen molecules on the surface of plutonium gallium system is hole-site vertical adsorption with the adsorption energy size of 10.7 eV. The bonding between oxygen atom and surface is mainly due to the overlapping hybridization of Pu-6s, Pu-7s, Pu-6d, Ga-3d and O-2p orbitals. Oxygen molecules mainly interact with the atoms of the first layer on the surface of the plutonium gallium system. The oxygen atoms after stable adsorption are able to diffuse to the subsurface of the plutonium gallium system after overcoming the energy barrier of 16.7 eV and form a stable structure. The research results reveal the initial reaction process and adsorption law of oxygen on the surface of plutonium gallium system from microscopic level, which is helpful to further explore the surface corrosion prevention technology of plutonium gallium system and improve the reliability and safety of plutonium gallium alloy components.

Vitamin K2 Improves Osteogenic Differentiation by Inhibiting STAT1 via the Bcl-6 and IL-6/JAK in C3H10 T1/2 Clone 8 Cells.

Osteogenic activity of vitamin K2 (VK2), a small molecular nutrient, has been suggested. However, the underlying mechanisms have not been fully elucidated. Therefore, this study aimed to explore the mechanisms by which VK2 promotes osteogenic differentiation. The effects of VK2 on osteogenic differentiation indicators were determined in C3H10 T1/2 clone 8 cells. The RNA-seq analysis was used to explore the hypothesis that VK2 promotes osteogenic differentiation. Small interfering RNA (siRNA) assay and plasmid transfection assay were used to determine the potential role of VK2 in the modulation of Bcl-6/STAT axis and IL-6/JAK/STAT signaling pathway. VK2 significantly increased alkaline phosphatase (ALP) activity, ALP, osteocalcin (OCN), and RUNX2 abundance, and RUNX2 protein expression. RNA-seq analysis showed that there were 314 differentially expressed genes (DEGs) upregulated and 1348 DEGs downregulated by VK2. PPI analysis determined the top 10 hub genes upregulated or downregulated by VK2. Overexpression of Bcl-6 increased osteogenic differentiation and decreased expression of STAT1. Administration with VK2 restored the inhibition by siBcl-6 in osteogenic differentiation. Knockdown of IL-6 decreased the mRNA levels of genes associated with the JAK/STAT signaling pathway, and increased markers of osteoblast differentiation. Furthermore, treatment with VK2 improved inhibition in osteogenic differentiation and decreased enhancement of JAK/STAT signaling pathway related genes by overexpression of IL-6. Our study suggests that VK2 could improve osteogenic differentiation via the Bcl-6/STAT axis and IL-6/JAK/STAT signaling pathway.

Effects of Pelleting and Long-Term High-Temperature Stabilization on Vitamin Retention in Swine Feed.

The objective of this study was to study the effect of pelleting and long-term high-temperature stabilization on the retention of vitamin A, vitamin E, vitamin B2, and vitamin B6 in swine feed. Piglet diets (diet 1 and 3) were pelleted after conditioning at 83 °C for 120 s, and were high-temperature stabilized at 90 °C for 8.5 min after pelleting; the finishing pig diets (diet 2, 4, and 5) were pelleted after conditioning at 82 °C for 90 s, and were high-temperature stabilized at 85 °C for 9 min after pelleting; the samples were obtained before condition, after condition, after pelleting, and after cooling. The contents of vitamin A and vitamin E in diets 1−5 and vitamin B2, and vitamin B6 in diets 3−5 were detected. The results showed that: (1) the conditioning process had no significant effect on the retention of vitamin A, vitamin E, vitamin B2, and vitamin B6 in all experimental diets (p > 0.05); (2) the pelleting process and high-temperature stabilization process after pelleting had different degrees of influence on vitamins, among which the stabilization process had a more significant effect on the retention of vitamins. After pelleting and long-term high-temperature stabilization, the retention of vitamin A, vitamin E, and B2, and vitamin B6 were 68.8−77.3%, 56.9−90.1%, 63.8−70.3%, and 60.1−67.0%, respectively. In the process of pelleting and long-term high-temperature stabilization, the retention of vitamin A, vitamin E, vitamin B2, and vitamin B6 in the feed were significantly reduced (p < 0.05). Therefore, vitamin loss during high temperature and over a long period of time is worth considering, and vitamins must be over-supplemented.

Effects of α-glycerol monolaurate on intestinal morphology, nutrient digestibility, serum profiles, and gut microbiota in weaned piglets.

This experiment was conducted to investigate the effects of dietary supplementation of α-glycerol monolaurate (α-GML) on the growth performance, nutrient digestibility, serum profiles, intestinal morphology, and gut microbiota of weaned piglets. A total of 96 healthy 28-d-old (Duroc × Landrace × Yorkshire) weaned piglets with body weight of 8.34 ± 0.05 kg were randomly divided into 2 treatment groups with 6 replicate pens and 8 piglets per pen. The control group was fed a basal diet and the experimental group was fed the basal diet supplemented with 1,000 mg/kg α-GML. The experiment lasted for 28 d. Dietary supplementation with α-GML had no effect on average daily gain, average daily feed intake, or gain to feed ratio in piglets (P > 0.05); however, it reduced (P < 0.05) diarrhea rate of piglets on days 15 to 28. The apparent total tract digestibility of dry matter (DM), crude protein (CP), ether extract (EE), and gross energy (GE) on day 14, and DM, organic matter, CP, EE, and GE on day 28 increased (P < 0.05) with α-GML supplementation. Moreover, higher (P < 0.05) glutathione peroxidase activity and interleukin-10 (IL-10) concentration, and lower (P < 0.05) malondialdehyde and tumor necrosis factor-α concentrations were observed in piglets supplemented with α-GML compared with the control group on day 14. Compared with the control group, the villus height/crypt depth in the duodenum and villus height in the jejunum and ileum were significantly greater (P < 0.05) in the α-GML group. Dietary α-GML supplementation significantly increased (P < 0.05) the relative abundance of Firmicutes, while decreasing (P < 0.05) Bacteroidota and Campilobacterota in the cecal contents; significantly increased (P < 0.05) the relative proportion of Lactobacillus and Blautia species, reduced (P < 0.05) Eubacterium_rectale_ATCC_33656, Campylobacter, and uncultured_bacterium_Alloprevotella species. Thus, dietary α-GML supplementation at 1,000 mg/kg reduces diarrhea rate, improves intestinal morphology, nutrient digestibility, antioxidant capacity, and immune status, and ameliorates gut microbiota in weaned piglets.

Glycerol monolaurate (GML) is naturally present in breast milk as well as other natural sources such as coconut oil and is widely used as a food additive. Dietary α-GML is used in animal production due to its safe-guarding health and growth-promoting effects. In the present study, α-GML was evaluated for growth performance, blood parameters, and intestinal health in piglets. Dietary α-GML helped piglets digest dry matter, crude protein, ether extract, and gross energy in feed. The blood parameters and intestinal structure of piglets fed the diet containing 1,000 mg/kg α-GML were improved. In addition, α-GML supplementation promoted the colonization of beneficial bacteria and inhibited the number of harmful bacteria. In the current study, dietary α-GML was responsible for improving the health status, intestinal morphology, and digestion and absorption of nutrients of weaned piglets with less diarrhea.

Menaquinone 4 Reduces Bone Loss in Ovariectomized Mice through Dual Regulation of Bone Remodeling.

Epidemiologic studies showed that higher vitamin K (VK) consumption correlates with a reduced risk of osteoporosis, yet the dispute remains about whether VK is effective in improving bone mineral density (BMD). We sought to discover the anti-osteoporotic effect of menaquinone-4 (MK-4) and evaluate the expression of critical genes related to bone formation and bone resorption pathways in the body. Fifty female C57BL/6 mice (aged 13 weeks) were randomly arranged to a sham-operated group (SHAM, treated with corn oil) and four ovariectomized groups that were administered corn oil (OVX group), estradiol valerate (EV, 2 mg/kg body weight as the positive control), low or high doses of VK (LVK and HVK; 20 and 40 mg MK-4/kg body weight, respectively) by gavage every other day for 12 weeks. Body and uterine weight, serum biochemical indicators, bone microarchitecture, hematoxylin-eosin (HE) staining, and the mRNA expression of critical genes related to bone formation and bone resorption pathways were assessed. Either dose of MK-4 supplementation increased the alkaline phosphatase (ALP), decreased the undercarboxylated osteocalcin (ucOC) and tartrate-resistant acid phosphatase (TRACP, p < 0.05) levels, and presented higher BMD, percent bone volume (BV/TV), trabecular thickness (Tb.Th), and lower trabecular separation (Tb.Sp) and structure model index (SMI, p < 0.05) compared with the OVX group. Additionally, both doses of MK4 increased the mRNA expression of Runx2 and Bmp2 (p < 0.05), whereas the doses down-regulated Pu.1 and Nfatc1 (p < 0.05) mRNA expression, the high dose decreased Osx and Tgfb (p < 0.05) mRNA expression, and the low dose decreased Mitd and Akt1 (p < 0.05) mRNA expression. These data show the dual regulatory effects of MK-4 on bone remodeling in ovariectomized mice: the promotion of bone anabolic activity and inhibition of osteoclast differentiation, which provides a novel idea for treating osteoporosis.

Effects of Sources and Forms of Vitamin K3 on Its Storage Stability in Vitamin Premixes or Vitamin Trace Mineral Premixes.

Six types of vitamin K3 (VK3); two sources (menadione sodium bisulfite, MSB; menadione nicotinamide bisulfite, MNB), and three different forms (crystal, micro-capsule, and micro-sphere) were used to determine the retention of VK3 in vitamin premixes (Experiment 1) or vitamin trace mineral (VTM) premixes (Experiment 2) after 1, 2, 3, and 6 months of storage. The retention of VK3 in vitamin premixes was evaluated at 25 °C/60% relative humidity or 40 °C/75% relative humidity in an incubator in Experiment 1 and in VTM premixes (choline chloride: 0 vs. 16,000 mg/kg) stored at room temperature in Experiment 2. The VK3 retention in vitamin premix or VTM premix decreased significantly with the extension of storage time (p < 0.05). In Experiment 1, the VK3 retention was higher in the 25 °C/60% incubator (56%) than in the 40 °C/75% incubator (28%). The MNB retention (52%) was higher than MSB retention (32%). The retention of VK3 in micro-capsules (43%) or micro-spheres (48%) was higher than the crystal form (35%) after six months of storage. In Experiment 2, there was no difference between the retention of MSB (49%) or MNB (47%). The retention of VK3 of micro-capsule (51%) or micro-sphere (54%) was higher than that of crystal form (40%). The VK3 retention was higher in the choline-free group (51%) than in the choline group (47%) after six months of storage. Finally, the predicted equations of VK3 retention with storage time in vitamin premixes or VTM premixes were established. The R2 of the prediction equations was ≥0.9005, indicating that time is an important factor in predicting VK3 retention. In conclusion, the higher temperature-relative humidity, choline had negative effects on VK3 retention during premix storage. MNB retention was higher than MSB during storage of vitamin premix. The encapsulated forms of VK3, micro-capsules and micro-spheres, could improve VK3 storage stability in vitamin premix and VTM premix.

Effects of Sources or Formulations of Vitamin K3 on Its Stability during Extrusion or Pelleting in Swine Feed.

Two studies were conducted to determine the stability of vitamin K3 (VK3) in swine diets during extrusion or pelleting. The two sources were menadione sodium bisulfite (MSB) and menadione nicotinamide bisulfite (MNB), and the three formulations were crystal micro-capsule formulation and micro-sphere formulation. The recovery of six types of VK3 in swine diets was investigated after extrusion at 100 °C or 135 °C in Experiment 1. The recovery of six types of VK3 was investigated when the diets were pelleted at 60 °C (low temperature; LT) or 80 °C (high temperature; HT) and the length to diameter ratios were 5.2:1 (low length to diameter ratio; LR) or 7.2:1 (high length to diameter ratio; HR) in Experiment 2. In Experiment 1, MNB recovery (72.74%) was higher than MSB recovery (64.67%) after extrusion, while recovery of VK3 of crystal (74.16%) was higher than the recovery of micro-capsule (65.25%) and micro-sphere (66.72%). The recovery of VK3 (70.88%) was higher when extruded at 100 °C than that at 135 °C (66.54%). In Experiment 2, MNB recovery (86.21%) was higher than MSB recovery (75.49%) after pelleting, while the recovery of VK3 of micro-capsule (85.06%) was higher than the recovery of crystal (81.40%) and micro-sphere (76.09%). The recovery of VK3 (75.50%) was lower after HTHR pelleting than LTLR (83.62%), LTHR (81.52%) or HTLR (82.76%) treatment. Our results show that MNB has greater stability than MSB. VK3 of crystal or VK3 of micro-capsule were recommended for extrusion or pelleting, respectively.