Effects of Gel Properties and Water Migration during Ultra-High Pressure Coupled Heat Treatment on Bighead Carp Surimi

In order to elucidate the mechanism of the changes in gel properties of bighead carp surimi during ultra-high pressure coupled heat treatment, this paper investigated the changes in gel properties, protein structure and water migration of bighead carp surimi during ultra-high pressure coupled heat treatments (300 MPa/5 min, 40 ℃/30 min, 90 ℃/20 min), and carried out clustered heat maps and Pearson correlation analyses. The results showed that ultra-high pressure coupled heat treatment significantly improved the gel properties of bighead carp surimi (P<0.05). The gel strength, texture and whiteness of bighead carp surimi gel showed an increasing trend with ultra-high pressure, ultra-high pressure combined with one-stage heat treatment, and ultra-high pressure combined with two-stage heat treatment. The gel strength and whiteness of the ultra-high pressure coupled heat treatment (300PSH) surimi gels increased by 477.75% and 43.38%, respectively, compared to the atmospheric pressure treated samples (0.1P). The proportion of β-folded structure in the proteins of bighead carp surimi gels increased significantly (P<0.05) during the different treatments, and myosin heavy chain cross-linked aggregation. Meanwhile, the content of active sulfhydryl groups and surface hydrophobicity of surimi gel were significantly reduced (P<0.05), and the proteins formed a denser and more ordered network structure through disulfide bonds and hydrophobic interaction, leading to the migration of immobile water to bound water, which ultimately resulted in significant improvements in the gel strength, texture properties, whiteness and water holding capacity of surimi gel. This study can provide theoretical basis for application of ultra-high pressure coupled heat treatment technology and development of bighead surimi products

Whole-genome sequencing reveals genomic characterization of Listeria monocytogenes from food in China

IntroductionListeria monocytogenes is a foodborne bacterium that could persist in food and food processing environments for a long time. Understanding the population structure and genomic characterization of foodborne L. monocytogenes is essential for the prevention and control of listeriosis.MethodsA total of 322 foodborne L. monocytogenes isolates from 13 geographical locations and four food sources in China between 2000 and 2018 were selected for whole-genome sequencing.ResultsIn silico subtyping divided the 322 isolates into five serogroups, 35 sequence types (STs), 26 clonal complexes (CCs) and four lineages. Serogroup IIa was the most prevalent serogroup and ST9 was the most prevalent ST of foodborne L. monocytogenes strains isolated in China. The in-depth phylogenetic analysis on CC9 revealed that ST122 clone might be original from ST9 clone. Furthermore, 23 potentially relevant clusters were identified by pair-wised whole-genome single nucleotide polymorphism analysis, indicating that persistent- and/or cross-contamination had occurred in markets in China. ST8 and ST121 were the second and third top STs of L. monocytogenes in China, which had heterogeneity with that of L. monocytogenes isolates from other countries. The antibiotic resistance genes aacA4, tetM, tetS, dfrG carried by different mobile elements were found in L. monocytogenes strains. One lineage II strain carrying Listeria Pathogenicity Island 3 was first reported. In addition, a novel type of premature stop codon in inlA gene was identified in this study.DiscussionThese findings revealed the genomic characteristics and evolutionary relationship of foodborne L. monocytogenes in China on a scale larger than previous studies, which further confirmed that whole-genome sequencing analysis would be a helpful tool for routine surveillance and source-tracing investigation

Macleaya cordata isoquinoline alkaloids attenuate Escherichia coli lipopolysaccharide-induced intestinal epithelium injury in broiler chickens by co-regulating the TLR4/MyD88/NF-κB and Nrf2 signaling pathways

This study sought to explore the effects and potential mechanisms of dietary supplementation with isoquinoline alkaloids (IA) from Macleaya cordata to alleviate lipopolysaccharide (LPS)-induced intestinal epithelium injury in broilers. A total of 486 1-day-old broilers were assigned at random to a control (CON) group, LPS group, and LPS+IA group in a 21-d study. The CON and LPS groups received a basal diet, while the LPS+IA group received a basal diet supplemented with 0.6 mg/kg IA. At 17, 19, and 21 days of age, the LPS and LPS+BP groups were injected intraperitoneally with LPS, and the CON group was intraperitoneally injected equivalent amount of saline solution. The results manifested that LPS injection caused intestinal inflammation and lipid peroxidation, disrupted intestinal barrier and function, and increased the abundance of harmful microorganisms. However, dietary IA supplementation alleviated LPS-induced adverse changes in intestinal morphology, apoptosis, mucosal barrier integrity, cecum microorganisms, and homeostasis disorder by decreasing inflammatory cytokines and enhancing antioxidant-related genes expressions; inhibited LPS-induced increases in TLR4 and NF-κB expressions and decreases in Nrf2 and GPX1 genes expressions. Our findings indicated that Macleaya cordata IA addition attenuated LPS-induced intestinal epithelium injury and disorder of intestinal homeostasis by enhancing the anti-inflammatory and antioxidant capacity of broiler chickens possibly via co-regulating TLR4/MyD88/NF-κB and Nrf2 signaling pathways

Synthesis and Growth Mechanism of Ni Nanotubes and Nanowires

Highly ordered Ni nanotube and nanowire arrays were fabricated via electrodeposition. The Ni microstructures and the process of the formation were investigated using conventional and high-resolution transmission electron microscope. Herein, we demonstrated the systematic fabrication of Ni nanotube and nanowire arrays and proposed an original growth mechanism. With the different deposition time, nanotubes or nanowires can be obtained. Tubular nanostructures can be obtained at short time, while nanowires take longer time to form. This formation mechanism is applicable to design and synthesize other metal nanostructures and even compound nanostuctures via template-based electrodeposition

Lathyrol promotes ER stress-induced apoptosis and proliferation inhibition in lung cancer cells by targeting SERCA2

Lathyrol is a natural product isolated from the traditional Chinese medicine Semen Euphorbiae with unknown anti-tumor effects. We found that lathyrol had significant inhibitory effect on lung cancer cells by inducing apoptosis and inhibiting proliferation. Subsequently, we demonstrated for the first time that endoplasmic reticulum (ER) stress is a key anti-tumor mechanism of lathyrol. Furthermore, we found that lathyrol can induce ER stress in lung cancer cells by upregulating the protein expression levels of GRP78, PERK, p-eIF2α, CHOP, and ATF4, and the inhibitory effect of lathyrol on lung cancer cells was significantly reversed when cells were pretreated with ER stress inhibitor. In addition, we found that inhibition of SERCA2 resulted in depletion of the ER Ca2+ pool followed by a sustained increase in cytoplasmic Ca2+ levels, eventually leading to ER stress induced tumor cell apoptosis and proliferation inhibition. Lathyrol targeted SERCA2 to cause a significant upregulation of Ca2+ levels, and the inhibitory effect of lathyrol on lung cancer cells was significantly reversed after pretreatment with SERCA2 agonist. Taken together, our data suggest that lathyrol exerts its anti-tumor effect primarily by targeting SERCA2. Our findings highlight the potential for lathyrol as a new candidate drug for the treatment of lung cancer

Reservoir-Computing for Dispersion Compensation in Digital Filter Multiple Access PON

Chromatic dispersion (CD) is one of the key limitations of increasing the transmission performance for short-reach transmission. The available optical dispersion-compensation techniques are not favored due to their high complexity and other expenses such as power. Reservoir computing is reviewed as a promising technique to provide equalization with memory in an easily trainable fashion, and the properties of the reservoir network are directly linked to system performance. In this article, the digital reservoir computing (RC) based CD-compensation technique is investigated to enhance the transmission performance for digital filter multiple access passive optical network (PON). Numerical results show within 50-km single mode fiber transmission distance for 16 GHz signal bandwidth, the RC-based technique is effective for CD compensation to improve the capacity by 25&#x0025;

Improving the Sensitivity and Linear Range of Photoionization Ion Mobility Spectrometry via Confining the Ion Recombination and Space Charge Effects Assisted by Theoretical Modeling

Photoionization (PI) is an efficient ionization source for ion mobility spectrometry (IMS) and mass spectrometry. Its hyphenation with IMS (PI-IMS) has been employed in various on-site analysis scenarios targeting a wide range of compounds. However, the signal intensity and linear dynamic range of PI-IMS at ambient pressure usually do not follow the Beer–Lambert law predictions, and the factors causing that negative deviation remain unclear. In this work, a variable pressure PI-IMS system was developed to examine the ion loss effects from factors like ion recombination and space charge by varying its working pressure from 1 to 0.1 bar. Assisted by theoretical modeling, it was found that ion recombination could contribute up to 90% of signal intensity loss for ambient pressure PI-IMS setups. Lowering the pressure and increasing the electric field in PI-IMS helped suppress the ion recombination process and thus an optimal pressure Poptimal appeared for best signal intensity, despite the decreased net ion number density and the increased space charge effect. A simplified theoretical equation taking ion recombination as the primary ion loss factor was derived to link Poptimal with analyte concentration and electric field in PI-IMS, enabling a swift optimization of the PI-IMS performance. For example, compared to ambient pressure, PI-IMS at a Poptimal of 0.4 bar provided a signal intensity increment of more than 400% for 0.716 ppmv toluene and also expanded the linear dynamic range by more than two times. Revealing factors influencing the PI-IMS response would also benefit the applications of other chemical ionization sources in IMS or mass spectrometry (MS)

Reference gene selection for qRT-PCR analysis of flower development in <i>Lagerstroemia indica</i> and <i>L</i>. <i>speciosa</i>

<div><p>Quantitative real-time polymerase chain reaction (qRT-PCR) is a prevalent method for gene expression analysis, depending on the stability of the reference genes for data normalization. <i>Lagerstroemia indica</i> and <i>L</i>. <i>speciosa</i> are popular ornamental plants which are famous for the long flowering period. However, no systematic studies on reference genes in <i>Lagerstroemia</i> have yet been conducted. In the present study, we selected nine candidate reference genes (<i>GAPDH</i>, <i>TUA</i>, <i>TUB</i>, <i>18S</i>, <i>RPII</i>, <i>EF-1α</i>, <i>ATC</i>, <i>EIF5A</i> and <i>CYP</i>) and evaluated their expression stability in different tissues during floral development of <i>L</i>. <i>indica</i> and <i>L</i>. <i>speciosa</i> using four algorithms (geNorm, NormFinder, BestKeeper and, RefFinder). Results showed that <i>RPII</i> and <i>EF-1α</i> were the most stably expressed and suitable reference genes for both of <i>Lagerstroemia</i> species. Moreover, <i>ACT</i> exhibited high expression stability in <i>L</i>. <i>indica</i> and <i>GAPDH</i> was a suitable reference gene for <i>L</i>. <i>speciosa</i> in different flower development stages. <i>TUB</i> was an unsuitable reference gene for gene expression normalization due to significant variations in expression across all samples. Finally, we verified the reliability of the selected candidate reference genes by amplifying an <i>AGAMOUS</i> homolog (<i>LsAG1</i>) of <i>Arabidopsis thaliana</i>. This study provides a list of suitable reference genes, thereby broadening the genetic basis of the gene expression patterns in <i>Lagerstroemia</i> species.</p></div

Genes and primer sets used for qRT-PCR in <i>L</i>. <i>indica</i> and <i>L</i>. <i>speciosa</i>.

<p>Genes and primer sets used for qRT-PCR in <i>L</i>. <i>indica</i> and <i>L</i>. <i>speciosa</i>.</p