The application of antimicrobial peptides as growth and health promoters for swine

With the widespread ban on the use of antibiotics in swine feed, alternative measures need to be sought to maintain swine health and performance, Antimicrobial peptides （AMPs） are part of the nonspecific defense system and are natural antibiotics produced by plants, insects, mammalians, and micro-organisms as well as by chemical synthesis. Due to their broad microbicidal activity against various fungi, bacteria and enveloped viruses AMPs are a potential alternative to conventional antibiotics for use in swine production. This review focuses on the structure and mechanism of action of AMPs, as well as their effects on performance, immune function and intestinal health in pigs. The aim is to provide support for the application of AMPs as feed additives replacing antibiotics in swine nutrition.

CuI/Nylon Membrane Hybrid Film with Large Seebeck Effect

Room-temperature thermoelectric materials are important for converting heat into electrical energy.As a widebandgap semiconductor material,CuI has the characteristics of non-toxicity,low cost,and environmental friendliness.In this work,CuI powder was synthesized by a wet chemical method,then CuI film was formed by vacuum assisted filtration of the CuI powder on a porous nylon membrane,followed by hot pressing.The film exhibits a large Seebeck coefficient of 600μV·K^(-1)at room temperature.In addition,the film also shows good flexibility(~95%retention of the electrical conductivity after being bent along a rod with a radius of 4 mm for 1000 times).A finger touch test on a single-leg TE module indicates that a voltage of 0.9 mV was immediately generated within 0.5 s from a temperature difference of 4 K between a finger and the environment,suggesting the potential application in wearable thermal sensors.

The Effects of Amino Acid Nutritional Deficiency on the Expression of Protein Metabolism-Related Genes in the Mammary Gland and Muscle Tissues of Lactating Mice

The mammary gland tissue exhibits a series of responses that are different from those of muscle and other peripheral tissues under amino acid deficiency. So, this present study was designed to investigate the effects of amino acid nutritional deficiency on the expression of protein metabolism-related genes in the mammary gland and muscle tissues of lactating mice. A total of 60 postpartum, lactating Kunming white mice were selected and randomly divided into 5 groups;each group contained 12 mice. Group A was the control group. The mice in group A were maintained on a normal diet after the initiation of lactation. Group B (starved) was given normal saline via intragastric administration. Group C (energy) was given glucose solution via intragastric administration. Groups D and E received a sodium caseinate solution via intragastric administration, which provided 0.5 g protein/d and 1.5 g protein/d, respectively. The results showed the following. 1) When the mice were exposed to nutritional stress caused by dietary amino acid deficiency, the β-casein mRNA expression level was increased in the mammary gland tissue. The increase in β-casein expression was the most significant in the energy-supplemented group, followed by the starved group (P P 14k and C2 (P P P < 0.05). 5) The phosphorylation level of p70S6K was elevated in the muscle tissues collected from the treatment groups. However, the magnitude of the increase was far smaller compared to that in the mammary gland tissues.

G protein-coupled receptor 35 attenuates nonalcoholic steatohepatitis by reprogramming cholesterol homeostasis in hepatocytes

Nonalcoholic fatty liver disease(NAFLD)is the most common chronic liver disease worldwide.Fat accumulation“sensitizes”the liver to insult and leads to nonalcoholic steatohepatitis(NASH).G protein-coupled receptor 35(GPR35)is involved in metabolic stresses,but its role in NAFLD is unknown.We report that hepatocyte GPR35 mitigates NASH by regulating hepatic cholesterol homeostasis.Specifically,we found that GPR35 overexpression in hepatocytes protected against high-fat/cholesterol/fructose(HFCF)diet-induced steatohepatitis,whereas loss of GPR35 had the opposite effect.Administration of the GPR35 agonist kynurenic acid(Kyna)suppressed HFCF diet-induced steatohepatitis in mice.Kyna/GPR35 induced expression of StAR-related lipid transfer protein 4(STARD4)through the ERK1/2 signaling pathway,ultimately resulting in hepatic cholesterol esterification and bile acid synthesis(BAS).The overexpression of STARD4 increased the expression of the BAS rate-limiting enzymes cytochrome P450 family 7 subfamily A member 1(CYP7A1)and CYP8B1,promoting the conversion of cholesterol to bile acid.The protective effect induced by GPR35 overexpression in hepatocytes disappeared in hepatocyte STARD4-knockdown mice.STARD4 overexpression in hepatocytes reversed the aggravation of HFCF diet-induced steatohepatitis caused by the loss of GPR35 expression in hepatocytes in mice.Our findings indicate that the GPR35–STARD4 axis is a promising therapeutic target for NAFLD.

Pathogenicity and risk of cross-species transmission of Aerococcus viridans isolated from Tian-e-zhou National Reserve for Lipotes vexillifer in Shishou,China

During the survey of potential pathogens in the Tian-e-zhou National Reserve for Lipotes vexillifer in Shishou,China,isolate SS20210504 was isolated from the diseased prey fish-Pelteobagrus fulvidraco and was identified as Aerococcus viridans through 16S rRNA gene,morphological observation,and physiological and biochemical analysis.Artificial infection trials with fish through different methods were conducted.Results indicated that the isolate of SS2021504 caused mortality in fish with the LD50 of 1.0×106.2 CFU/mL,1.0×107.9 CFU/mL and 1.0×106.8 CFU/mL with the infection method of intraperitoneal injection,co-immersion,and scratch immersion,respectively.Challenged fish exhibited hemorrhages signs similar to naturally diseased fish.Histology analysis showed that the liver and kidney were the principal target organs of isolate SS2021504 in fish,and obvious vacuolation and karyopyknosis occurred in the above organs.To evaluate the pathogenicity of isolate SS20210504 in mice,healthy mice and immunosuppressed mice were further experimentally infected with bacteria,respectively.No death was observed either in healthy mice or in immunocompromised mice.However,the immunocompromised mice inoculated with bacteria showed obvious clinical symptoms and severe damage to multiple organs.The inflammatory signaling pathways were significantly activated with upregulated levels of Myd88,TNFα,AP-1,IL-1β,IL-6,and IFN-γgene in the spleen from the immunocompromised mice after infected with isolate SS20210504.These findings imply that isolate SS20210504 has the potential risk to YFPs and residents.Continued surveillance of A.viridans and other pathogens in the TZO reserve is suggested to prevent outbreaks in prey fish,YFPs,and residents as well.

Effects of feed form and feed particle size on growth performance,carcass characteristics and digestive tract development of broilers

This study was conducted to evaluate the effects of feed form(mash and crumble-pellet) and feed particle size(fine, medium and coarse) on growth performance, carcass characteristics and digestive tract development of broilers. A total of 1,152 one day-old Ross 308 mixed-sex broilers were used in a factorial arrangement(2×3) based on a completely randomized design with six replicates of 32 birds each.Higher average daily gain(ADG) and average daily feed intake(ADFI) were observed(P < 0.01) for birds fed the crumble-pellet diets(CPD) than for those fed the mash diets(MD) during starter, grower and the entire experiment period. From d 1 to 40, birds fed CPD had a higher(P < 0.01) body weight(BW) than those fed MD. Birds fed CPD had a lower(P < 0.01) feed:gain ratio(F:G) during the starter phase than those fed MD. Medium or coarse particle size increased(P < 0.01) ADG and ADFI during the starter phase, but birds fed fine particle size diets had lower(P < 0.01) F:G during the grower phase. In MD,medium and coarse particle sizes resulted in higher(P < 0.05) BW, ADG and ADFI than fine particle size during the whole experiment. In CPD, particle size had no significant effect on growth performance, as indicated by a feed form × particle size interaction(P < 0.05). At 41 days of age, ten birds per treatment were randomly selected and killed for slaughter yields and digestive tract characteristics determination.It was shown that particle size and feed form alone had no significant effect on slaughter yields, so changes was the feed form × particle size interaction. The relative empty weight of the gizzard was greater(P < 0.01) and the relative length of the ileum was longer(P < 0.05) in birds fed MD than in those fed CPD. Overall, CPD improved growth performance during the entire period of the study with effects being less evident during the finisher phase than during the starter and grower phases, and the effect of feed particle size varied depending on feed form.

4-Phenylbutyric acid accelerates rehabilitation of barrier function in IPEC-J2 cell monolayer model

As the first line of defence against pathogens and endotoxins crossing the intestine-blood barrier,the intestinal epithelial barrier plays a determinant role in pigs’health and growth.4-Phenylbutyric acid(4-PBA),an aromatic fatty acid,was reported to benefit homeostasis of endoplasmic reticulum and protein synthesis.However,whether 4-PBA affects intestinal epithelial barrier function in pigs is unknown.This study aimed to explore the effects of 4-PBA on the intestinal barrier function,using in vitro models of well-differentiated intestinal porcine epithelial cell(IPEC-J2)monolayers in the transwell plates.Cell monolayers with or without 4-PBA(1.0 mmol/L)treatment were challenged with physical scratch,deoxynivalenol(DON,2.0μg/mL,48 h),and lipopolysaccharide(LPS,5.0μg/mL,48 h),respectively.Transepithelial electrical resistance(TEER)and fluorescein isothiocyanate-dextran(FD-4)permeability were measured to indicate barrier integrity and permeability.Real-time PCR and Western blot were conducted to determine relative gene and protein expressions of tight junction proteins.As expected,physical scratch,DON,and LPS challenges decreased TEER and increased FD-4 permeability.4-PBA treatment accelerated cell mitigation and rehabilitation of the physical scratch-damaged intestinal epithelial barrier but did not alleviate DON or LPS induced barrier damage.However,once 48-h DON and LPS challenges were removed,rehabilitation of the epithelial barrier function of IPEC-J2 monolayer was accelerated by the 4-PBA treatment.Also,the relative gene and protein expressions of zonula occludens-1(ZO-1),occludin,and claudin-1 were further upregulated by the 4-PBA treatment during the barrier rehabilitation.Taken together,4-PBA accelerated the IPEC-J2 cell monolayer barrier recovering from physical scratch,DON-,and LPS-induced damage,via enhancing cell mitigation and expressions of tight junction proteins.

MOF-derived Co_(9)S_(8) nano-flower cluster array modified separator towards superior lithium sulfur battery

Lithium sulfur batteries with high energy density are thought to be the most potential energy storage technology that can be commercialized.However,the shuttle effect of polysulfides deteriorates its electrochemical performance.Herein,a novel Co_(9)S_(8)nanostructure derived from metal organic framework material(MOF)was explored by simple liquid phase reaction and heat vulcanization of2-methylimidazole and Co(NO_(3))_(2)·6 H_(2)O on the surface of the original PP separator.The Co_(9)S_(8)nano-flower cluster array wall was vertically and closely arranged with the thickness of 200 nm,and the polysulfide can be adsorbed by its physical and chemical action to slow down the"shuttle effect".It is found that the cell with the modified separator can achieve an ideal discharge capacity of about 600 mAh/g at 1 C.The specific capacity is maintained at 500 mAh/g after 200 cycles,with only 0.11%of capacity decay per cycle.It provides a new way for the utilization of MOF material derivatives to modify the separator in order to improve the electrochemical performance of lithium-sulfur batteries.

Treatment of coking wastewater by a novel electric assisted micro-electrolysis filter

A newly designed electric assisted micro-electrolysis filter（E-ME） was developed to investigate its degradation efficiency for coking wastewater and correlated characteristics. The performance of the E-ME system was compared with separate electrolysis（SE） and micro-electrolysis（ME） systems. The results showed a prominent synergistic effect on COD removal in E-ME systems. Gas chromatography/mass spectrometry（GC–MS） analysis confirmed that the applied electric field enhanced the degradation of phenolic compounds.Meanwhile, more biodegradable oxygen-bearing compounds were detected. SEM images of granular activated carbon（GAC） showed that inactivation and blocking were inhibited during the E-ME process. The effects of applied voltage and initial p H in E-ME systems were also studied. The best voltage value was 1 V, but synergistic effects existed even with lower applied voltage. E-ME systems exhibited some p H buffering capacity and attained the best efficiency in neutral media, which means that there is no need to adjust p H prior to or during the treatment process. Therefore, E-ME systems were confirmed as a promising technology for treatment of coking wastewater and other refractory wastewater.

Melatonin shapes bacterial clearance function of porcine macrophages during enterotoxigenic Escherichia coli infection

Due to the immature gastrointestinal immune system,weaning piglets are highly susceptible to pathogens,e.g.,enterotoxigenic Escherichia coli(ETEC).Generally,pathogens activate the immune cells(e.g.,macrophages)and shape intracellular metabolism(including amino acid metabolism);nevertheless,the metabolic cues of tryptophan(especially melatonin pathway)in directing porcine macrophage function during ETEC infection remain unclear.Therefore,this study aimed to investigate the changes in the serotonin pathway of porcine macrophages during ETEC infection and the effect of melatonin on porcine macrophage functions.Porcine macrophages(3D4/21 cells)were infected with ETEC,and the change of serotonin pathway was analysed by reverse transcription PCR and metabolomic analysis.The effect of melatonin on porcine macrophage function was also studied with proteomic analysis.In order to investigate the effect of melatonin on bacterial clearance function of porcine macrophages during ETEC infection,methods such as bacterial counting,reverse transcription PCR and western blotting were used to detect the corresponding indicators.The results showed that ETEC infection blocked melatonin production in porcine macrophages(P<0.05)which is largely associated with the heat-stable enterotoxin b(STb)of ETEC(P<0.05).Interestingly,melatonin altered porcine macrophage functions,including bacteriostatic and bactericidal activities based on proteomic analysis.In addition,melatonin pretreatment significantly reduced extracellular lactate dehydrogenase(LDH)activity(P<0.05),indicating that melatonin also attenuated ETEC-triggered macrophage death.Moreover,melatonin pretreatment resulted in the decrease of viable ETEC in 3D4/21 cells(P<0.05),suggesting that melatonin enhances bacterial clearance of porcine macrophages.These results suggest that melatonin is particularly important in shaping porcine macrophage function during ETEC infection.