In the present study, we aimed to elucidate the effects of stevia extract on production performance, serum immune indexes, intestinal structure, and cecum microbial structure. We randomly divided 800 ...46-week-old Roman hens into 5 groups, with eight replicates in each group and 20 chickens in each replicate. The control group was fed a basal diet, whereas the four experimental groups were fed 50, 100, 200, and 400 mg/kg stevia extracts. The study period was 24 weeks. The addition of different concentrations of the stevia extract to the diet resulted in significant secondary changes in the egg production rate at 1–12 weeks (P < 0.05). Furthermore, the addition of 50 and 100 mg/kg stevia extract to the diet significantly increased serum IgM and IgG levels in laying hens (P < 0.05) but linearly decreased serum IL-1β levels (P < 0.05). Serum T-SOD activity linearly increased (P = 0.057); however, serum biochemical indexes showed no significant differences. Stevia extract tended to increase the ratio of the duodenal villi height to the depth of the crypt (P = 0.067), with no obvious lesions in the duodenum, jejunum, and ileum. In addition, stevia extract increased the relative abundance of species at the phylum level, with the abundance of Bacteroides and Firmicutes exhibiting significant secondary changes (P < 0.05). The ACE and Chao1 indexes suggested that stevia extract addition significantly increased the alpha diversity of cecum microorganisms in laying hens. Furthermore, NMDS analysis based on operational taxonomic units revealed that stevia extract addition increased the beta diversity of cecum microorganisms in laying hens. Adding a certain amount of stevia extract to feed can improve the production performance, immune ability, and intestinal health of laying hens to some extent, and we recommend an effective level of 200mg/kg of stevia extract for laying hen diets.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
This paper presents a wideband substrate integrated H-plane horn antenna loaded with a novel E-plane corrugation. Classical SIW H-plane horn antennas suffer from poor impedance matching, large ...E-plane half-power beamwidth and strong back radiation due to the thinness of the substrates. A substrate integrated E-plane corrugation is introduced as an effective solution, implemented using the multi-layer printed circuit board (PCB) technique. The elaborated corrugated SIW horn is well matched with reflection coefficients less than <inline-formula><tex-math notation="LaTeX">-</tex-math></inline-formula>10 dB from 26 to 40 GHz. The back radiation suppression reflected by front-to-back ratios is improved to minimum 20 dB and up to 40 dB in the entire Ka-band. Furthermore, the corrugation reduces the half-power beamwidth of the E-plane radiation patterns successfully, e.g. from 180<inline-formula><tex-math notation="LaTeX">^{\circ }</tex-math></inline-formula> to 80<inline-formula><tex-math notation="LaTeX">^{\circ }</tex-math></inline-formula> at 30 GHz, whereas the H-plane patterns are maintained and unaffected. Consequently, the antenna gain is well enhanced. A prototype of the corrugated horn is fabricated and then measured. The measurement is in good agreement with the simulation. The proposed corrugated SIW horn antenna is compact in a planar structure so as to easy integration and array deployment. The wide bandwidth, narrow E-plane half-power beamwidth and low back radiation make it very promising for applications as millimeter-wave probes or handset antennas.
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•The DPP-Ⅳ inhibitory activity of walnut protein hydrolysates was investigated.•Peptides were purified by ultrafiltration and SP Sephadex C-25.•Peptides rich in basic amino acid ...showed higher DPP-Ⅳ inhibitory activity.•Nine novel potential DPP-Ⅳ inhibitory peptides were identified.•The molecular mechanism of peptides binding to DPP-Ⅳ was elucidated.
Walnut protein was hydrolyzed with different proteases to evaluate the hydrolytic efficiency and dipeptidyl peptidase IV (DPP-IV) inhibitory activity in vitro. All of walnut protein hydrolysates (WPHs) exhibited DPP-IV inhibitory activity and Alcalase-derived hydrolysate (WPH-Alc) with better DPP-IV inhibitory activity of 33.90% (at 0.50 mg/mL) was subsequently separated by ultrafiltration and cation exchange chromatography on a SP Sephadex C-25 column. The results showed that fractions with lower molecular weight and higher basic amino acid residues possessed stronger DPP-IV inhibitory activity. Comparably, the obtained fraction B with the yield of 19.80% had the highest DPP-IV inhibitory activity of 76.19% at 0.25 mg/mL. Moreover, nine novel DPP-IV inhibitory peptides were identified using MALDI-TOF/TOF-MS. Molecular docking revealed the peptides could interact with DPP-IV through hydrogen bonds, salt bridges, hydrophobic interactions, π-cation bonds and π-π bonds. The walnut DPP-IV inhibitory peptides showed better stability with heating treatment, pH treatment, or in vitro gastrointestinal digestion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
In this study, five fractions (F–I to F–V) were successfully isolated from cottonseed protein hydrolysates (CPH) by using ion exchange resin system, and proved to be mainly composed of peptides with ...molecular weights less than 1 kDa by size exclusion high performance liquid chromatography (SEC-HPLC). All fractions possessed the DPPH radical and ABTS radical cation scavenging abilities. However, the antibacterial experiment revealed F–I and CPH had no inhibition against E. coli. By analyzing the composition of amino acids, the antioxidant and antibacterial activities were found to be positively correlated with basic amino acid contents (Arg and Lys), but negatively correlated with acidic residual (Glu and Asp). Furthermore, the in vitro digestion had slightly effects on antibacterial activity of the fractions (CPH, Fraction I-Ⅴ), while it showed great impacts on the antioxidant capacity. The work here provided basic theory and a new strategy for preparing bifunctional peptides from cottonseed protein, which could be used as an alternative in the functional food formulations.
•Bioactive peptides were isolated from cottonseed protein hydrolysates.•The peptides had both antioxidant capacity and antibacterial activity.•The two activities expressed positive correlation with basic amino acid content.•The two capabilities showed negative correlation with acidic amino acid content.•In vitro digestion proved different effect on antibacterial and antioxidant activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Sulfate cellulose nanocrystal (CNC) dispersions always present specific self-assembled cholesteric mesophases which is easily affected by the inherent properties of particle size, surface charge, and ...repulsion or affinity interaction, and external field force generated from ionic potential of added electrolytes, magnetic or electric field, and mechanical shearing or stretching. Aiming at understanding the liquid crystal orientation and fiber alignment under high-voltage electric field, randomly distributed, uniform-aligned, or core–sheath nanofibrous mats involving charged CNCs and PVA were electrospun; and among them, specific straight arrayed fine nanofibers with average diameter of 270 nm were manufactured by using a simple and versatile gap collector. Moreover, arrayed composite nanofibers regularly aligned along the vertical direction of gap plates and selectively reflected frequent and continuous birefringence which was regarded as nematic phases of CNCs induced by the uniaxial stretching under high-voltage electric field. As a synergic effect of rigidness of nanocrystals and stretching orientation of nematic phases, the aligned nanofibrous arrays exhibited a higher tensile strength and strain than the randomly oriented or core–sheath nanofibrous mats at the same loading of CNCs. By contrast, mesophase transition of CNCs from cholesteric to nematic occurred in the coaxially spun core–sheath nanofibers at a loss of long-ranged chiral twist. Hence, the structure-effect relationship between liquid crystal orientation of charged nanorods in polymer-based fine nanofibers and the flexibility or mechanical integrity of the aligned fiber array will be favorable for strategic development of functional liquid crystal fabrics.
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IJS, KILJ, NUK, PNG, UL, UM
In this study, we explored the fractionation and identification of antibacterial peptides from cottonseed protein hydrolysates obtained using Alcalase. The cottonseed protein hydrolysates were ...preliminarily separated using Sephadex C-25, and fraction P5 exhibited antibacterial activity against four tested strains, including Gram-positive and Gram-negative bacteria, at concentrations ranging from 1 to 4 mg/mL. The potential antibacterial peptides in fraction P5 were then isolated by reverse-phase high-performance liquid chromatography based on a specific reaction of Arg with benzaldehyde. Nine novel peptides encoded in cottonseed proteins were identified by mass spectrometry, and three peptides (KDFPGRR, LGLRSGIILCNV, and DENFRKF) with antibacterial activities of 77.7%, 69.3%, and 45.0% at 1.0 mg/mL, respectively, were chemically synthesized. Fluorescence labeling and staining assays confirmed that antibacterial peptides could combine and interact with the surface of the cell membrane. In addition, sensitivity analysis of the environmental conditions revealed that antibacterial peptides were not influenced by temperature and pH, but they were sensitive to Ca2+, with a decrease in antibacterial activity decreased of 40% occurring as the concentration of Ca2+ increased from 0.05% to 5%.Our results indicated that cottonseed protein could be used as a potential source of antibacterial peptides that could be applied to food systems and the feed industry.
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•Antimicrobial peptides were separated by specific reaction of arginine.•Nine potential antibacterial bioactive peptides were identified.•The peptide KDFPGRR showed the highest antibacterial activity.•Antibacterial peptides destroy the cells by interaction with cell membrane.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Defatted soybean meal, walnut meal, cottonseed meal and wheat gluten flour were hydrolyzed with Alcalase to prepare vegetable protein hydrolysates (VPHs), respectively. Through ethanol fractionation, ...peptides with lower molecular weight and higher hydrophobicity were enriched in ethanol-soluble VPHs (VPHs-Es), and metal-binding content of VPHs-Es was significantly increased. Zinc and iron were much easier to combine with lower molecular weight peptides (MW < 1 kDa) than calcium. Comparably, ethanol-soluble soybean protein hydrolysates (SPH-Es) had a better metal-binding capacity. The Fourier transform infrared spectra and amino acid composition analysis revealed that the carboxyl oxygen and amino nitrogen were the main binding sites for chelating, and divalent metals had different chelating preferences. The molecular weight distribution, particle size and scanning electron microscope analysis demonstrated significant microstructural differences among the metal (Ca, Zn, Fe) chelates. In particular, obvious aggregation occurred in Ca-SPH-Es, which was induced by hydrogen bonding and electrostatic interaction. Moreover, the gastrointestinal stability of metal chelates was 71.48%, 90.70% and 85.60% for Ca-SPH-Es, Zn-SPH-Es and Fe-SPH-Es, respectively, thus providing a guidance for the exploration of organometallic supplements.
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•Ethanol fractionation significantly increased the metal-binding content of ethanol-soluble peptides.•Hydrophobicity and molecular size of peptides greatly influenced the metal-binding capacity.•Calcium, zinc and iron had different chelating preferences with peptides.•Gastrointestinal stability of metal-SPH-Es was high.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
A foam fractionation technology of FeCl3 from the simulated aqueous solution was studied by using dodecylbenzenesulphonic acid and (1-hexadecyl)trimethyl ammonium hydroxide as the surfactants, in ...order to develop a new desalination method, which has the virtues of simple equipments and technology, non-pollution and low cost. The effects of operating parameters such as pH and height of the bulk liquid, superficial gas velocity, surfactant dosage and separation sequence of Fe3+ and Cl- on the enrichment ratio and removal rate of FeCl3 were investigated. The experimental results show that, under the optimum conditions, the removals of FeCl3 approached to 60.5%, enrichment ratio reached 1.7. Compared with the other surfactants, this technology will not introduce new acid radical ions and metal ions in the aqueous solutions and provides a basis for a new method of removing salt by foam fractionation.
This experiment was designed to investigate the effects of curcumin levels on growth, flesh quality, and oxidative resistance in juvenile genetically improved farmed tilapia (GIFT, Oreochromis ...niloticus). Fish (initial mean weight: 4.5 ± 0.3 g) were randomly fed five diets with curcumin supplementation levels of 0 (control), 150, 300, 600, and 1,200 mg/kg. After 60 days of feeding, the hepatosomatic index was significantly reduced in the curcumin supplemented groups. The 300 mg/kg group had the highest crude protein content of the whole fish. Compared to the control group, the crude fat content of whole fish in the 150 and 300 mg/kg groups was significantly reduced by 18.83%–19.74%, respectively. The highest values for muscular hardness, chewiness, myofibrillar density, and proportion of small-sized myofibers (<40 μm) were observed in the 300 mg/kg group. The levels of total nonessential amino acids and bitter amino acids in muscle were significantly lower in the 150 and 300 mg/kg groups than in the other groups. The 300 mg/kg group had higher levels of free sweet amino acids in the muscle than the other groups. Muscles from the 150, 300, and 600 mg/kg groups had significantly higher levels of umami amino acids than in the other groups. The levels of total free nonessential amino acids and total amino acids in serum were significantly higher in the 300 mg/kg group than in the control group. Serum aspartate transaminase activity was significantly lower in the curcumin supplementation groups than in the control group, and the serum alanine aminotransferase activity was significantly lower in the 150 mg/kg group than in the other groups. Serum superoxide dismutase activity was significantly higher in the curcumin supplementation groups than in the control group. Serum catalase activity was significantly higher in the 150 mg/kg group than in the other groups. The serum malondialdehyde level was lowest in the 150 mg/kg group. These results suggest that dietary curcumin supplementation in the diet at 150–300 mg/kg can effectively improve the nutritional value, muscle flavor, and antioxidant capacity of tilapia.
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•An oil extractor with diverse wettability has been prepared.•The oil extractor can clean up the oil on the water without second pollution.•There is an underwater superoleophobic ...cellulose sponge inside the extractor.•Oil could be desorbed when the oil-contaminated sponge was placed in the water.
The frequent marine oil spill accidents in nowadays has aroused great attention all over the world. Lots of superwetting absorption materials with 2D or 3D structures are fabricated to efficiently remove oil spill, but the desorption of the absorbed oil is more difficult. Oil contaminants adhere on the surface will decline the performance and reusability of the absorption materials. Discarding or burning them will bring secondary pollution. Faced with these problems, we prepared an oil extractor integrated by a superhydrophobic-superoleophilic stainless steels wire mesh and a 3D porous cellulose sponge with superhydrophilicity-superoleophilicity in air and superoleophobicity in water. The oil extractor can in situ collect oil spill no matter on the water or under the water. More importantly, it is good at underwater oil desorption, which ensure the recovery and reuse of oil, and meanwhile avoid the materials being fouled by oils. More than 85.5% of crude oil could be successfully discharged only in 2min when the oil-contaminated sponge was placed in water. The findings in this work not only put forward a new strategy for collection and reuse of various “oils”, but also offer a facile method to achieve a combination of two kinds of materials with diverse wettability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
