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Towards realizing the future quantum internet1,2, a pivotal milestone entails the transition from two-node proof-of-principle experiments conducted in laboratories to comprehensive multi-node set-ups on large scales. Here we report the creation of memory-memory entanglement in a multi-node quantum network over a metropolitan area. We use three independent memory nodes, each of which is equipped with an atomic ensemble quantum memory3 that has telecom conversion, together with a photonic server where detection of a single photon heralds the success of entanglement generation. The memory nodes are maximally separated apart for 12.5 kilometres. We actively stabilize the phase variance owing to fibre links and control lasers. We demonstrate concurrent entanglement generation between any two memory nodes. The memory lifetime is longer than the round-trip communication time. Our work provides a metropolitan-scale testbed for the evaluation and exploration of multi-node quantum network protocols and starts a stage of quantum internet research.
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Influenza B viruses have cocirculated during most seasonal flu epidemics and can cause significant human morbidity and mortality due to their rapid mutation, emerging drug resistance, and severe impact on vulnerable populations. The influenza B M2 proton channel (BM2) plays an essential role in viral replication, but the mechanisms behind its symmetric proton conductance and the involvement of a second histidine (His27) cluster remain unclear. Here we performed membrane-enabled continuous constant-pH molecular dynamics simulations on wildtype BM2 and a key H27A mutant channel to explore its pH-dependent conformational switch. Simulations captured the activation as the first histidine (His19) protonates and revealed the transition at lower pH values compared to AM2 is a result of electrostatic repulsions between His19 and preprotonated His27. Crucially, we provided an atomic-level understanding of the symmetric proton conduction by identifying preactivating channel hydration in the C-terminal portion. This research advances our understanding of the function of BM2 function and lays the groundwork for further chemically reactive modeling of the explicit proton transport process as well as possible antiflu drug design efforts.
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Thiamin and its phosphate derivatives are ubiquitous molecules involved as essential cofactors in many cellular processes. The de novo biosynthesis of thiamin employs the parallel synthesis of 4-methyl-5-(2-hydroxyethyl)thiazole (THZ-P) and 4-amino-2-methyl-5(diphosphooxymethyl) pyrimidine (HMP) pyrophosphate (HMP-PP), which are coupled to generate thiamin phosphate. Most organisms that can biosynthesize thiamin employ a kinase (HMPK or ThiD) to generate HMP-PP. In nearly all cases, this enzyme is bifunctional and can also salvage free HMP, producing HMP-P, the monophosphate precursor of HMP-PP. Here we present high-resolution crystal structures of an HMPK from Acinetobacter baumannii (AbHMPK), both unliganded and with pyridoxal 5-phosphate (PLP) noncovalently bound. Despite the similarity between HMPK and pyridoxal kinase enzymes, our kinetics analysis indicates that AbHMPK accepts HMP exclusively as a substrate and cannot turn over pyridoxal, pyridoxamine, or pyridoxine nor does it display phosphatase activity. PLP does, however, act as a weak inhibitor of AbHMPK with an IC50 of 768 µM. Surprisingly, unlike other HMPKs, AbHMPK catalyzes only the phosphorylation of HMP and does not generate the diphosphate HMP-PP. This suggests that an additional kinase is present in A. baumannii, or an alternative mechanism is in operation to complete the biosynthesis of thiamin.
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Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in humans and animals. The study aimed to evaluate the efficacy of bLf as an adjuvant combined with AMP (N6) in the treatment of E. coli-induced bacterial enteritis. Sixty female ICR mice were randomly divided into six groups: CK group, NC group:(infected and untreated), N6 treatment group (20 mg/kg), bLf treatment group (100 mg/kg), bLf+ N6-A treatment group (10 mg/kg N6+100 mg/kg bLf) and bLf+N6- b group (20 mg/kg N6+100 mg/kg bLf), the clinical symptoms, intestinal morphology, inflammatory response and serum metabolites were monitored. The results showed that: compared with the NC group, the bLf-N6-A and bLf-N6-B treatment groups had significant reductions in TNF-α and IL-6, significant increases in IL-10, and significant reductions in endotoxin and DAO in plasma (p<0.05). Meanwhile, the bLf-N6-A and bLf-N6-B treatment groups significantly increased the expression of ZO-1, claudin-1 and occludin, increased the height of small intestinal mucosal villi and VH/CD after ETEC K88-induced intestinal injury (p<0.05). The supplementation of bLf and N6 relieved enteritis by balancing intestinal mucosal immunity, improving intestinal morphology and barrier function. BLf combined with N6 can be used as an effective therapeutic strategy for the treatment of bacterial enteritis.
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BACKGROUND: Myocardial ischemia/reperfusion (I/R) injury is a common pathological process in clinical practice. Developing effective therapeutic strategies to reduce or prevent this injury is crucial. The article aimed to investigate the role and mechanism of mesencephalic astrocyte-derived neurotrophic factor (MANF) and its key subdomains in modulating myocardial I/R-induced cardiomyocyte apoptosis. METHODS: MANF stable knockout cell line and MANF mutant overexpression plasmids were constructed. The effects of MANF and mutants on apoptosis and endoplasmic reticulum (ER) stress related proteins were evaluated in hypoxia/reoxygenation-induced HL-1 cardiomyocytes by western blot, immunofluorescence, Tunel and flow cytometry. Echocardiography, ELISA, TTC and Masson were used to observe the effects of recombinant MANF protein (rMANF) on cardiac function in myocardial I/R mice. RESULTS: This study observed increased expression of MANF in both myocardial infarction patients and I/R mice. MANF overexpression in cardiomyocytes decreased ER stress-induced apoptosis, while MANF knockout exacerbated it. rMANF improved cardiac function in I/R mice by reducing injury and inflammation. This study specifically demonstrates that mutations in the α-helix of MANF were more effective in reducing ER stress and cardiomyocyte apoptosis. Mechanistically, MANF and the α-helix mutant attenuated I/R injury by inhibiting the JAK1/STAT1/NF-κB signaling pathway in addition to reducing ER stress-induced apoptosis. CONCLUSION: These findings highlight MANF and its subdomains as critical regulators of myocardial I/R injury, offering promising therapeutic targets with significant clinical implications for I/R-related diseases.
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Apoptose , Traumatismo por Reperfusão Miocárdica , Miócitos Cardíacos , Fatores de Crescimento Neural , Transdução de Sinais , Animais , Humanos , Masculino , Camundongos , Linhagem Celular , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático , Janus Quinase 1/metabolismo , Janus Quinase 1/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/genética , Miócitos Cardíacos/metabolismo , Fatores de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/genética , NF-kappa B/metabolismo , Fator de Transcrição STAT1/metabolismoRESUMO
The noble metal-based hybrid plasmon mode features low loss and strong field localization, making it widely applicable in the field of nanophotonic devices. However, due to the high loss of noble metals, the gain threshold is unacceptably high, usually larger than 0.1â µm-1. Here we present a hybrid plasmonic waveguide consisting of a SiO2 layer coated Na nanowire and a hexagonal semiconductor nanowire. Based on the high performance of the proposed waveguide, the Purcell factor exceeding 120 and a confinement factor above 90% are achieved, leading to an ultra-low gain threshold of 0.02117â µm-1. In addition, the proposed waveguide exhibits an extremely low cross talk, making it highly suitable for applications in compact photonic integrated devices. The proposed waveguide may contribute to the development of low-threshold nano-lasers and promote other applications in nanophotonics.
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OBJECTIVE: Sepsis-induced cardiomyopathy (SICM) is a life-threatening complication. Phospholipase D2 (PLD2) is crucial in mediating inflammatory reactions and is associated with the prognosis of patients with sepsis. Whether PLD2 is involved in the pathophysiology of SICM remains unknown. This study aimed to investigate the effect of PLD2 knockout on SICM and to explore potential mechanisms. METHODS: The SICM model was established using cecal ligation and puncture in wild-type and PLD2-knockout mice and lipopolysaccharide (LPS)-induced H9C2 cardiomyocytes. Transfection with PLD2-shRNA lentivirus and a PLD2 overexpression plasmid were used to interfere with PLD2 expression in H9C2 cells. Cardiac pathological alterations, cardiac function, markers of myocardial injury, and inflammatory factors were used to evaluate the SICM model. The expression of pyroptosis-related proteins (NLRP3, cleaved caspase 1, and GSDMD-N) was assessed using western blotting, immunofluorescence, and immunohistochemistry. RESULTS: SICM mice had myocardial tissue damage, increased inflammatory response, and impaired heart function, accompanied by elevated PLD2 expression. PLD2 deletion improved cardiac histological changes, mitigated cTNI production, and enhanced the survival of the SICM mice. Compared with controls, PLD2-knockdown H9C2 exhibits a decrease in inflammatory markers and lactate dehydrogenase production, and scanning electron microscopy results suggest that pyroptosis may be involved. The overexpression of PLD2 increased the expression of NLRP3 in cardiomyocytes. In addition, PLD2 deletion decreased the expression of pyroptosis-related proteins in SICM mice and LPS-induced H9C2 cells. CONCLUSION: PLD2 deletion is involved in SICM pathogenesis and is associated with the inhibition of the myocardial inflammatory response and pyroptosis through the NLRP3/caspase 1/GSDMD pathway.
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Cardiomiopatias , Caspase 1 , Camundongos Knockout , Miócitos Cardíacos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Fosfolipase D , Piroptose , Sepse , Animais , Masculino , Camundongos , Ratos , Cardiomiopatias/etiologia , Cardiomiopatias/genética , Caspase 1/metabolismo , Caspase 1/genética , Linhagem Celular , Gasderminas , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteínas de Ligação a Fosfato/genética , Proteínas de Ligação a Fosfato/metabolismo , Fosfolipase D/genética , Fosfolipase D/metabolismo , Sepse/complicações , Sepse/genética , Transdução de SinaisRESUMO
Quantum Mechanics/Molecular Mechanics (QM/MM) can describe chemical reactions in molecular dynamics (MD) simulations at a much lower cost than ab initio MD. Still, it is prohibitively expensive for many systems of interest because such systems usually require long simulations for sufficient statistical sampling. Additional MM degrees of freedom are often slow and numerous but secondary in interest. Coarse-graining (CG) is well-known to be able to speed up sampling through both reduction in simulation cost and the ability to accelerate the dynamics. Therefore, embedding a QM system in a CG environment can be a promising way of expediting sampling without compromising the information about the QM subsystem. Sinitskiy and Voth first proposed the theory of Quantum Mechanics/Coarse-grained Molecular Mechanics (QM/CG-MM) with a bottom-up CG mapping. Mironenko and Voth subsequently introduced the DFT-QM/CG-MM formalism to couple a Density Functional Theory (DFT) treated QM system and to an apolar environment. Here, we present a more complete theory that addresses MM environments with significant polarity by explicitly accounting for the electrostatic coupling. We demonstrate our QM/CG-MM method with a chloride-methyl chloride SN2 reaction system in acetone, which is sensitive to solvent polarity. The method accurately recapitulates the potential of mean force for the substitution reaction, and the reaction barrier from the best model agrees with the atomistic simulations within sampling error. These models also have generalizability. In two other reactive systems that they have not been trained on, the QM/CG-MM model still achieves the same level of agreement with the atomistic QM/MM models. Finally, we show that in these examples the speed-up in the sampling is proportional to the acceleration of the rotational dynamics of the solvent in the CG system.
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AIMS: Recent studies have indicated an association between intestinal flora and lipids. However, observational studies cannot indicate causality. In this study, we aimed to investigate the potentially causal relationships between the intestinal flora and blood lipids. METHODS: We performed a bidirectional two-sample Mendelian Randomization (MR) analysis to investigate the causal relationship between intestinal flora and blood lipids. Summary statistics of genome-wide association studies (GWASs) for the 211 intestinal flora and blood lipid traits (n = 5) were obtained from public datasets. Five recognized MR methods were applied to assess the causal relationship with lipids, among which, the inverse-variance weighted (IVW) regression was used as the primary MR method. A series of sensitivity analyses were performed to test the robustness of the causal estimates. RESULTS: The results indicated a potential causal association between 19 intestinal flora and dyslipidemia in humans. Genus Ruminococcaceae, Christensenellaceae, Parasutterella, Terrisporobacter, Parabacteroides, Class Erysipelotrichia, Family Erysipelotrichaceae, and order Erysipelotrichales were associated with higher dyslipidemia, whereas genus Oscillospira, Peptococcus, Ruminococcaceae UCG010, Ruminococcaceae UCG011, Dorea, and Family Desulfovibrionaceae were associated with lower dyslipidemia. After using the Bonferroni method for multiple testing correction, Only Desulfovibrionaceae [Estimate = -0.0418, 95% confidence interval [CI]: 0.9362-0.9826, P = 0.0007] exhibited stable and significant negative associations with ApoB levels. The inverse MR analysis did not find a significant causal effect of lipids on the intestinal flora. Additionally, no significant heterogeneity or horizontal pleiotropy for IVs was observed in the analysis. CONCLUSION: The study suggested a causal relationship between intestinal flora and dyslipidemia. These findings will provide a meaningful reference to discover dyslipidemia for intervention to address the problems in the clinic.
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Aterosclerose , Dislipidemias , Microbioma Gastrointestinal , Humanos , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Aterosclerose/diagnóstico , Aterosclerose/epidemiologia , Aterosclerose/genéticaRESUMO
Microcystins (MC)-RR is a significant analogue of MC-LR, which has been identified as a hepatotoxin capable of influencing lipid metabolism and promoting the progression of liver-related metabolic diseases. However, the toxicity and biological function of MC-RR are still not well understood. In this study, the toxic effects and its role in lipid metabolism of MC-RR were investigated in hepatoblastoma cells (HepG2cells). The results demonstrated that MC-RR dose-dependently reduced cell viability and induced apoptosis. Additionally, even at low concentrations, MC-RR promoted lipid accumulation through up-regulating levels of triglyceride, total cholesterol, phosphatidylcholines and phosphatidylethaolamine in HepG2 cells, with no impact on cell viability. Proteomics and transcriptomics analysis further revealed significant alterations in the protein and gene expression profiles in HepG2 cells treated with MC-RR. Bioinformatic analysis, along with subsequent validation, indicated the upregulation of CD36 and activation of the AMPK and PI3K/AKT/mTOR in response to MC-RR exposure. Finally, knockdown of CD36 markedly ameliorated MC-RR-induced lipid accumulation in HepG2 cells. These findings collectively suggest that MC-RR promotes lipid accumulation in HepG2 cells through CD36-mediated signal pathway and fatty acid uptake. Our findings provide new insights into the hepatotoxic mechanism of MC-RR.
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Antígenos CD36 , Ácidos Graxos , Metabolismo dos Lipídeos , Microcistinas , Transdução de Sinais , Humanos , Células Hep G2 , Antígenos CD36/metabolismo , Antígenos CD36/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Microcistinas/toxicidade , Transdução de Sinais/efeitos dos fármacos , Ácidos Graxos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Apoptose/efeitos dos fármacosRESUMO
Staphylococcus aureus is associated with dairy mastitis, which causes serious economic losses to dairy farming industry. Antibacterial peptide NZX showed good antibacterial activity against S. aureus. This study aimed to evaluate pharmacokinetics and pharmacodynamics of NZX against S. aureus-induced mouse mastitis. NZX exhibited potent in vitro antibacterial activity against the test S. aureus strains (minimal inhibitory concentration (MIC): 0.23-0.46 µM), low mutant prevention concentration (MPC: 1.18-3.68 µM), and a long post antibiotic effect (PAE: 2.20-8.84 h), which was superior to those of lincomycin and ceftiofur. Antibacterial mechanisms showed that NZX could penetrate the cell membrane, resulting in obvious cell membrane perforation and morphological changes, and bind to intracellular DNA. Furthermore, NZX had a good stability in milk environment (retention rate: 85.36%, 24 h) than that in mammary homogenate (47.90%, 24 h). In mouse mastitis model, NZX (25-400 µg/gland) could significantly reduce the bacterial load of mammary tissue in a dose-dependent manner. In addition, NZX (100 µg/gland) could relieve the inflammatory symptoms of mammary tissue, and significantly decreased its pathological scores. The concentration-time curve of NZX (100 µg/gland) in the mammary tissue was plotted and the corresponding pharmacokinetic parameters were obtained by non-compartment model calculation. Those parameters of Tmax, T1/2, Cmax and AUC were 0.5 h, 35.11 h, 32.49 µg/g and 391 µg·h/g, respectively. Therefore, these results suggest that NZX could act as a promising candidate for treating dairy mastitis disease caused by S. aureus. KEY POINTS: ⢠NZX could kill S. aureus by dual mechanism involved in membrane and DNA disruption ⢠NZX could relieve S. aureus-induced mouse mastitis ⢠Pharmacokinetic parameters of NZX in mouse mammary gland were obtained.
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Mastite Bovina , Infecções Estafilocócicas , Feminino , Camundongos , Animais , Bovinos , Humanos , Staphylococcus aureus , Antibacterianos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Modelos Animais de Doenças , Peptídeos Catiônicos Antimicrobianos/farmacologia , Mastite Bovina/microbiologia , DNA/metabolismoRESUMO
The low activity and yield of antimicrobial peptides (AMPs) are pressing problems. The improvement of activity and yield through modification and heterologous expression, a potential way to solve the problem, is a research hot-pot. In this work, a new plectasin-derived variant L-type AP138 (AP138L-arg26) was constructed for the study of recombination expression and druggablity. As a result, the total protein concentration of AP138L-arg26 was 3.1 mg/mL in Pichia pastoris X-33 supernatant after 5 days of induction expression in a 5-L fermenter. The recombinant peptide AP138L-arg26 has potential antibacterial activity against selected standard and clinical Gram-positive bacteria (G+, minimum inhibitory concentration (MIC) 2-16 µg/mL) and high stability under different conditions (temperature, pH, ion concentration) and 2 × MIC of AP138L-arg26 could rapidly kill Staphylococcus aureus (S. aureus) (> 99.99%) within 1.5 h. It showed a high safety in vivo and in vivo and a long post-antibiotic effect (PAE, 1.91 h) compared with vancomycin (1.2 h). Furthermore, the bactericidal mechanism was revealed from two dimensions related to its disruption of the cell membrane resulting in intracellular potassium leakage (2.5-fold higher than control), and an increase in intracellular adenosine triphosphate (ATP), and reactive oxygen species (ROS), the decrease of lactate dehydrogenase (LDH) and further intervening metabolism in S. aureus. These results indicate that AP138L-arg26 as a new peptide candidate could be used for more in-depth development in the future. KEY POINTS: ⢠The AP138L-arg26 was expressed in the P. pastoris expression system with high yield ⢠The AP138 L-arg26 showed high stability and safety in vitro and in vivo ⢠The AP138L-arg26 killed S. aureus by affecting cell membranes and metabolism.
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Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Staphylococcus aureus , Peptídeos Antimicrobianos , Pichia/genética , Pichia/metabolismo , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/metabolismo , Infecções Estafilocócicas/tratamento farmacológico , Testes de Sensibilidade Microbiana , Staphylococcus aureus Resistente à Meticilina/genéticaRESUMO
The wide-spreading of multidrug resistance poses a significant threat to human and animal health. Although antimicrobial peptides (AMPs) show great potential application, their instability has severely limited their clinical application. Here, self-assembled AMPs composed of multiple modules based on the principle of associating natural marine peptide N6 with ß-sheet-forming peptide were designed. It is noteworthy that one of the designed peptides, FFN could self-assemble into nanoparticles at 35.46 µM and achieve a dynamic transformation from nanoparticles to nanofibers in the presence of bacteria, resulting in a significant increase in stability in trypsin and tissues by 1.72-57.5 times compared to that of N6. Additionally, FFN exhibits a broad spectrum of antibacterial activity against multidrug-resistant (MDR) gram-positive (G+) and gram-negative (G-) bacteria with Minimum inhibitory concentrations (MICs) as low as 2 µM by membrane destruction and complemented by nanofiber capture. In vivo mouse mastitis infection model further confirmed the therapeutic potential and promising biosafety of the self-assembled peptide FFN, which can effectively alleviate mastitis caused by MDR Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and eliminate pathogenic bacteria. In conclusion, the design of peptide-based nanomaterials presents a novel approach for the delivery and clinical translation of AMPs, promoting their application in medicine and animal husbandry.
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Antibacterianos , Peptídeos Antimicrobianos , Farmacorresistência Bacteriana Múltipla , Escherichia coli , Testes de Sensibilidade Microbiana , Animais , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Camundongos , Feminino , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/uso terapêutico , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/uso terapêutico , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Mastite/tratamento farmacológico , Mastite/microbiologia , Nanofibras/química , Nanofibras/uso terapêutico , Nanopartículas/química , Camundongos Endogâmicos BALB C , HumanosRESUMO
American Oyster Defensin (AOD) is a marine peptide that is derived from North American mussels. It has been demonstrated to exhibit potent antimicrobial activity and high safety in both in vitro and in vivo models. In this study, to facilitate synthesis, mutants of AOD with fewer disulfide bonds were designed and subjected to structural, antimicrobial, and anti-biofilm analysis. The antimicrobial activity of AOD-derived peptides decreased after reduction in the disulfide bond, and among its three derivatives, only AOD-1 inhibited very few bacteria with a MIC value of 64 µg/mL, whereas the others had no inhibitory effect on pathogenic bacteria. The findings demonstrated that full disulfide bonds are indispensable for bactericidal activity, with the α-helix playing a pivotal role in inhibiting bacterial membranes. Furthermore, the results of the ATP, ROS, membrane potential, and membrane fluidity assays demonstrated that intracellular ATP, reactive oxygen species, and membrane fluidity were all increased, while membrane potential was reduced. This indicated that AOD resulted in the impairment of membrane fluidity and induced metabolic disorders, ultimately leading to bacterial death. The inhibitory effect of AOD on the biofilm of S. epidermidis G-81 was determined through the crystal violet and confocal microscopy. The results demonstrated that AOD exhibited a notable inhibitory impact on the biofilm of S. epidermidis G-81. The minimum biofilm inhibitory concentration of AOD on S. epidermidis G-81 was 16 µg/mL, and the minimum biofilm scavenging concentration was 32 µg/mL, which exhibited superior efficacy compared to that of lincomycin. The inhibitory effect on the primary biofilm was 90.3%, and that on the mature biofilm was 82.85%, with a dose-dependent inhibition effect. Concurrently, AOD cleared intra-biofilm organisms and reduced the number of biofilm-holding bacteria by six orders of magnitude. These data indicate that disulfide bonds are essential to the structure and activity of AOD, and AOD may potentially become an effective dual-action antimicrobial and anti-biofilm agent.
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Antibacterianos , Peptídeos Antimicrobianos , Biofilmes , Dissulfetos , Testes de Sensibilidade Microbiana , Biofilmes/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Animais , Dissulfetos/farmacologia , Dissulfetos/química , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Defensinas/farmacologia , Defensinas/química , Ostreidae , Staphylococcus epidermidis/efeitos dos fármacosRESUMO
To effectively perform the reliability analysis of the flap deflection angle, the reliability analysis framework is developed by introducing fault logic and a data-driven model. Herein, the fault logic analysis is used to study the fault mechanism and filter out the characteristic fault parameters that can be used to collect input data for data-driven modelling; the data-driven modelling is employed to establish a reliability analysis model with a small amount of input data. Under this proposed framework, the improved dung beetle optimization algorithm for back propagation (IDBO-BP) method is developed to perform the reliability modelling of the flap deflection angle. To validate the effectiveness of the proposed framework, we study the fault logic of flap symmetry and establish a surrogate model of flap deflection based on the fault parameters and the IDBO-BP algorithm. According to the predicted results of the flap deflection angle, the reliability model based on the fault mechanism can reflect the actual flap motion. At the same time, the proposed IDBO-BP algorithm has excellent modelling and simulation property by comparing with other optimization algorithms. Thus, the efforts of this study provide a new solution to the problem of reliable analysis with uncertain fault parameters. This article is part of the theme issue 'Physics-informed machine learning and its structural integrity applications (Part 1)'.
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Weaning is a crucial period in the pig's life cycle, which is frequently followed by gastrointestinal (GI) infections, diarrhea and even death. This study focused on the impact of bovine lactoferrin (bLF) supplementation on the intestinal health of weaning piglets. Weaning piglets (Duroc × Landrace × Yorkshire, 23 days) were randomly allocated into four groups, which included negative control group (CON): basic diet; positive control group (ANT): basic diet + 20 mg/kg flavomycin + 100 mg/kg aureomycin; treatment group bLF-A: basic diet + 1 g/kg bLF; treatment group bLF-B: basic diet + 3 g/kg bLF. The result showed that dietary supplementation of bLF can improve growth performance and reduce diarrhea, which exhibits dose-dependency (P < 0.05). Compared with CON group, supplementation with bLF significantly improved immunity, and increased villus height and ratio of villus height/crypt depth at the small intestinal mucosa (P < 0.05). The mRNA expression of claudin-1, occludin and ZO-1 was greatly increased in the ileum of bLF group on days 7 and 14 (P < 0.05). Furthermore, the supplementation of bLF increased the abundance of Lactobacillus and Bifidobacterium and decreased the abundance of Escherichia coli in the cecum on day 7 (P < 0.05). The dietary supplementation of bLF enhanced the growth performance, reduced diarrhea rate in weaning piglets by improving intestinal immunity, morphology and barrier function, balancing intestinal microbiota. And bLF can be a promising feed additive in relieving stress situation of weaning piglets.
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Suplementos Nutricionais , Lactoferrina , Estresse Psicológico , Suínos , Desmame , Animais , Diarreia/prevenção & controle , Diarreia/metabolismo , Dieta/veterinária , Escherichia coli/metabolismo , Imunidade , Mucosa Intestinal/metabolismo , Lactoferrina/farmacologia , Lactoferrina/metabolismo , Estresse Psicológico/prevenção & controleRESUMO
The marine peptide, American oyster defensin (AOD), is derived from Crassostrea virginica and exhibits a potent bactericidal effect. However, recombinant preparation has not been achieved due to the high charge and hydrophobicity. Although the traditional fusion tags such as Trx and SUMO shield the effects of target peptides on the host, their large molecular weight (12-20 kDa) leads to the yields lower than 20% of the fusion protein. In this study, a short and acidic fusion tag was employed with a compact structure of only 1 kDa. Following 72 h of induction in a 5 L fermenter, the supernatant exhibited a total protein concentration of 587 mg/L. The recombinant AOD was subsequently purified through affinity chromatography and enterokinase cleavage, resulting in the final yield of 216 mg/L and a purity exceeding 93%. The minimum inhibitory concentrations (MICs) of AOD against Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus galactis ranged from 4 to 8 µg/mL. Moreover, time-killing curves indicated that AOD achieved a bactericidal rate of 99.9% against the clinical strain S. epidermidis G-81 within 0.5 h at concentrations of 2× and 4× MIC. Additionally, the activity of AOD was unchanged after treatment with artificial gastric fluid and intestinal fluid for 4 h. Biocompatibility testing demonstrated that AOD, at a concentration of 128 µg/mL, exhibited a hemolysis rate of less than 0.5% and a cell survival rate of over 83%. Furthermore, AOD's in vivo therapeutic efficacy against mouse subcutaneous abscess revealed its capability to restrain bacterial proliferation and reduce bacterial load, surpassing that of antibiotic lincomycin. These findings indicate AOD's potential for clinical usage.
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Crassostrea , Animais , Camundongos , Crassostrea/metabolismo , Peptídeos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas Recombinantes/farmacologia , Defensinas/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
Lactoferrin is an iron-binding glycoprotein of the transferrin family that is found in most bodily fluids of mammals and has a variety of biological and beneficial functions, with great importance in health enhancement as a supplement for humans and other animals. More than 300 t of lactoferrin were produced in 2021, and this number is expected to grow yearly by 10% to 12%, to over 580 t in 2030. With new and important functions of lactoferrin being revealed and studied, focus on its industrial production and application is increasing accordingly. However, lactoferrin is mainly sourced from cheese whey or skim milk by cation-exchange column chromatography, which is a costly and low-quality method. A potential solution for lactoferrin global supply chain construction is proposed in this article as a complement to traditional routes of purification from whey or skim milk. The large-scale production of lactoferrin, mainly by recombinant yeast, mammal, and grain systems, as well as the market niche and product design, are discussed.
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Ultrasonic phased array imaging using full-matrix capture (FMC) has raised great interest among various communities, including the nondestructive testing community, as it makes full use of the echo space to provide preferable visualization performance of inhomogeneities. The conventional way of FMC data postprocessing for imaging is through beamforming approaches, such as delay-and-sum, which suffers from limited imaging resolution and contrast-to-noise ratio. To tackle these difficulties, we propose a deep learning (DL)-based image forming approach, termed FMC-Net, to reconstruct high-quality ultrasonic images directly from FMC data. Benefitting from the remarkable capability of DL to approximate nonlinear mapping, the developed FMC-Net automatically models the underlying nonlinear wave-matter interactions; thus, it is trained end-to-end to link the FMC data to the spatial distribution of the acoustic scattering coefficient of the inspected object. Specifically, the FMC-Net is an encoder-decoder architecture composed of multiscale residual modules that make local perception at different scales for the transmitter-receiver pair combinations in the FMC data. We numerically and experimentally compared the DL imaging results to the total focusing method and wavenumber algorithm and demonstrated that the proposed FMC-Net remarkably outperforms conventional methods in terms of exceeding resolution limit and visualizing subwavelength defects. It is expected that the proposed DL approach can benefit a variety of ultrasonic array imaging applications.
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With the accelerating growth of antimicrobial resistance (AMR), there is an urgent need for new antimicrobial agents with low or no AMR. Antimicrobial peptides (AMPs) have been extensively studied as alternatives to antibiotics (ATAs). Coupled with the new generation of high-throughput technology for AMP mining, the number of derivatives has increased dramatically, but manual running is time-consuming and laborious. Therefore, it is necessary to establish databases that combine computer algorithms to summarize, analyze, and design new AMPs. A number of AMP databases have already been established, such as the Antimicrobial Peptides Database (APD), the Collection of Antimicrobial Peptides (CAMP), the Database of Antimicrobial Activity and Structure of Peptides (DBAASP), and the Database of Antimicrobial Peptides (dbAMPs). These four AMP databases are comprehensive and are widely used. This review aims to cover the construction, evolution, characteristic function, prediction, and design of these four AMP databases. It also offers ideas for the improvement and application of these databases based on merging the various advantages of these four peptide libraries. This review promotes research and development into new AMPs and lays their foundation in the fields of druggability and clinical precision treatment.