Magnetic resonance/fluorescence dual-modality contrast agents targeting αvß6-overexpressing tumors based on A20FMDV2 peptide as a ligand.

Pancreatic ductal adenocarcinoma (PDAC) is a malignant digestive system tumor with a poor late-stage prognosis. This study aimed to identify new methods for the early detection of PDAC. The nanoprobe A20FMDV2-Gd-5-FAM was developed using A20FMDV2 (N1AVPNLRGDLQVLAQKVART20-NH2, A20FMDV2) as the ligand and characterized using dynamic light scattering, transmission electron microscopy, Fourier transform infrared analysis, and UV absorption spectroscopy. The binding of pancreatic cancer cells AsPC-1, MIA PaCa-2, and normal human pancreatic H6C7 cells (HPDE6-C7) to the probe was verified using laser confocal microscopy, and the biocompatibility of the probe was evaluated in vivo. In vivo magnetic resonance and fluorescence imaging were also performed on nude mice with subcutaneous pancreatic tumor xenografts to verify the bimodal imaging performance of the probe. The probe exhibited good stability and biocompatibility and an enhanced relaxation rate (25.46 ± 1.32 mM-1 s-1) than Gd-DTPA. Confocal laser scanning microscopy results revealed that the A20FMDV2-Gd-5-FAM probe could be successfully ingested and internalized, and infrared analysis results demonstrated that the probe was linked successfully. Finally, magnetic resonance T1WI imaging and intravital fluorescence imaging demonstrated the specific signal enhancement of the probe at the tumor site. In conclusion, the bimodal molecular probe A20FMDV2-Gd-5-FAM showed a stable magnetic resonance and fluorescence bimodal imaging performance and is a promising new approach for diagnosing early-stage cancers with a high integrin αvß6 expression.

ACE2 PET to reveal the dynamic patterns of ACE2 recovery in an infection model with pseudocorona virus.

Due to the COVID-19 pandemic, a series of sequelae, such as fatigue, tachypnea, and ageusia, appeared in long COVID patients, but the pathological basis was still uncertain. The targeted radiopharmaceuticals were of potential to systemically and dynamically trace the pathological changes. For the key ACE2 protein in the virus-host interaction, 68 Ga-cyc-DX600 was developed on the basis of DX600 as a PET tracer of ACE2 fluctuation and maintained the ability in differentiating ACE and ACE2. In the temporary infection model inhaled with the radio-traceable pseudovirus in the upper respiratory tract of male humanized ACE2 (hACE2) mice, organ-specific ACE2 dysfunction in acute period and the following ACE2 recovery in a relatively long period was visualized and quantified by ACE2 PET, revealing a complex pattern of virus concentration-dependent degree and time period-dependent tendency of ACE2 recovery, mainly a sudden decrease of apparent ACE2 in the heart, liver, kidneys, lungs, and so on, but the liver was of a quick functional compensation on ACE2 expression after a temporary decrease. ACE2 expression of most organs has recovered to a normal level at 15 days post inhalation, with brain and genitals still of a decreased SUVACE2 ;  meanwhile, kidneys were of an increased SUVACE2 . These findings on ACE2 PET were further verified by western blot. When compared with high-resolution computed tomography on structural changes and FDG PET on glycometabolism, ACE2 PET was superior in an earlier diagnostic window during infection and more comprehensive understanding of functional dysfunction post-infection. In the respective ACE2 PET/CT and ACE2 PET/MR scans of a volunteer, the repeatability of SUVACE2 and the ACE2 specificity were further confirmed. In conclusion, 68 Ga-cyc-DX600 was developed as an ACE2-specific tracer, and the corresponding ACE2 PET revealed the dynamic patterns of functional ACE2 recovery and provided a reference and approach to explore the ACE2-related pathological basis of sequelae in long COVID.

Effects of bioaugmentation by isolated Achromobacter xylosoxidans BP1 on PAHs degradation and microbial community in contaminated soil.

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic pollutants ubiquitous and persistent in soil. In order to provide a viable solution for bioremediation of PAHs-contaminated soil, a strain of Achromobacter xylosoxidans BP1 with superior PAHs degradation ability was isolated from contaminated soil at a coal chemical site in northern China. The degradation of phenanthrene (PHE) and benzo[a]pyrene (BaP) by strain BP1 was investigated in three different liquid phase cultures, and the removal rates of PHE and BaP by strain BP1 were 98.47% and 29.86% after 7 days under the conditions of PHE and BaP as the only carbon source, respectively. In the medium with the coexistence of PHE and BaP, the removal rates of BP1 were 89.44% and 9.42% after 7 days, respectively. Then, strain BP1 was investigated for its feasibility in remediating PAH-contaminated soil. Among the four PAHs-contaminated soils treated differently, the treatment inoculated with BP1 exhibited higher removal rates of PHE and BaP (p < 0.05), especially the CS-BP1 treatment (inoculation of BP1 into unsterilized PAHs-contaminated soil) showed 67.72%, 13.48% removal of PHE and BaP, respectively, over 49 days of incubation. Bioaugmentation also significantly increased the activity of dehydrogenase and catalase in the soil (p＜0.05). Furthermore, the effect of bioaugmentation on the removal of PAHs was investigated by measuring the activity of dehydrogenase (DH) and catalase (CAT) during incubation. Among them, the DH and CAT activities of CS-BP1 and SCS-BP1 (inoculation of BP1 into sterilized PAHs-contaminated soil) treatments inoculated with strain BP1 were significantly higher than those of treatments without BP1 addition during incubation (p < 0.01). The structure of the microbial community varied among treatments, but the Proteobacteria phylum showed the highest relative abundance in all treatments of the bioremediation process, and most of the bacteria with higher relative abundance at the genus level also belonged to the Proteobacteria phylum. Prediction of microbial functions in soil by FAPROTAX analysis showed that bioaugmentation enhanced microbial functions associated with the degradation of PAHs. These results demonstrate the effectiveness of Achromobacter xylosoxidans BP1 as a PAH-contaminated soil degrader for the risk control of PAHs contamination.

AMPK regulates behavior and physiological plasticity of Haliotis discus hannai under different spectral compositions.

In natural environments, the spectral composition of incident light is often subject to drastic changes due to the abundance of suspended particles, floating animals, and plants in coastal waters. In this study, after four months of culturing under blue light (NB), orange light (NY), dark environment (ND), and natural light (NN), the shell length and weight-specific growth rate in Pacific abalone, Haliotis discus hannai, were ranked in the following order: NY > NN > ND > NB. To understand the growth differences in abalone under these different light environments, we first performed 24-h video monitoring and found that the cumulative movement distance and duration were lowest in group NB, whereas the cumulative movement distance and duration were significantly higher in group ND than in any other group (P < 0.05). In group NB, the time spent hidden underneath the attachment substrate accounted for 81% of the resting time, but this ratio was lowest in group ND, at only 37% (P < 0.05). Next, LC-MS metabolomics identified 201 and 105 metabolites in NB vs. NN, ND vs. NN, and NY vs. NN under the positive and negative ion modes, respectively. According to the fold changes and annotations for differential metabolites in the KEGG enrichment pathways, adenosine, NAD+, cGMP, and arachidonic acid were used as differential metabolism markers, and the AMPK signaling pathway was enriched in every comparison group, and thus investigated further. The gene sequences of three subtypes of AMPK were obtained by cloning and we found that the expression levels of AMPKα and AMPKγ, and the AMP content were significantly higher in group NB than in any other group (P < 0.05). In addition, the ATP contents and adenylate energy charge values were ranked in the following order: NY > NN > ND > NB. According to in situ hybridization analysis, the three subtype genes were widely expressed in the hepatopancreas. Finally, the contents of many lipid metabolites differed significantly among groups and the expression levels of the triglyceride hydrolysis-related gene hormone sensitive lipase and fatty acid oxidation-related gene carnitine palmitoyltransferase 1 were higher in groups ND and NB than in groups NN and NY according to fluorescence quantification PCR (P < 0.05). The expression levels of fatty acid synthase and acetyl-CoA carboxylase were significantly lower in groups ND and NB than in groups NN and NY (P < 0.05). These findings indicated that differences in the spectral composition of incident light could reshape the behavior and physiological metabolism in abalone by influencing the "energy switch" AMPK, thereby providing some insights into the mechanisms that allow nocturnal marine organisms to adapt to different lighting environments.

Identification and Fine Mapping of the Recessive Gene BK-5, Which Affects Cell Wall Biosynthesis and Plant Brittleness in Maize.

The cellulose of the plant cell wall indirectly affects the cell shape and straw stiffness of the plant. Here, the novel brittleness mutant brittle stalk-5 (bk-5) of the maize inbred line RP125 was characterized. We found that the mutant displayed brittleness of the stalk and even the whole plant, and that the brittleness phenotype existed during the whole growth period from germination to senescence. The compressive strength was reduced, the cell wall was thinner, and the cellulose content was decreased compared to that of the wild type. Genetic analysis and map-based cloning indicated that bk-5 was controlled by a single recessive nuclear gene and that it was located in a 90.2-Kb region on chromosome 3 that covers three open reading frames (ORFs). Sequence analysis revealed a single non-synonymous missense mutation, T-to-A, in the last exon of Zm00001d043477 (B73: version 4, named BK-5) that caused the 951th amino acid to go from leucine to histidine. BK-5 encodes a cellulose synthase catalytic subunit (CesA), which is involved with cellulose synthesis. We found that BK-5 was constitutively expressed in all tissues of the germinating stage and silking stage, and highly expressed in the leaf, auricula, and root of the silking stage and the 2-cm root and bud of the germinating stage. We found that BK-5 mainly localized to the Golgi apparatus, suggesting that the protein might move to the plasma membrane with the aid of Golgi in maize. According to RNA-seq data, bk-5 had more downregulated genes than upregulated genes, and many of the downregulated genes were enzymes and transcription factors related to cellulose, hemicellulose, and lignin biosynthesis of the secondary cell wall. The other differentially expressed genes were related to metabolic and cellular processes, and were significantly enriched in hormone signal transduction, starch and sucrose metabolism, and the plant-pathogen interaction pathway. Taken together, we propose that the mutation of gene BK-5 causes the brittle stalk phenotype and provides important insights into the regulatory mechanism of cellulose biosynthesis and cell wall development in maize.

Heavy metal levels in the soil near typical coal-fired power plants: partition source apportionment and associated health risks based on PMF and HHRA.

In this study, five priority metals recommended by the Ministry of Ecology and Environment of China (MEEC) were investigated. In the Bijie region of Guizhou Province, three typical coal-fired power plants were chosen as the research locations. A combination of 24 soil samples was obtained at various distances and depths from the point source of contamination. The authors found that the average contents of As, Cd, Cr, Ni, and Pb were 14.15, 1.52, 16.80, 40.71, and 53.00 mg kg-1, respectively, with Cd and Pb pollution prominent. In another, soil heavy metal (SHM) content tends to increase or decrease dependently with the increase of sampling distance and depth, with total concentrations ranging from 77.14 to 157.33 mg kg-1. Combining PCA and PMF models, the number of source factors was determined more clearly and accurately using PCA, and the Q-value of PMF was used for validation. The PCA-PMF indicated that the primary anthropogenic sources were transportation-related activities and emissions from coal combustion. The health risks of SHMs under three different exposure routes were then assessed using the HHRA. The findings showed the five HMs in order of non-carcinogenic risk were As > Pb > Cr > Ni > Cd. The comprehensive non-carcinogenic risk for children under the oral intake route around plant B and C was greater than 1, pointing to a potential health risk to children from the soils. The carcinogenic risk of HM was less than 1.00E-04 for both single-factor and multifactor under all three exposure routes, which is below the tolerable limit.

An intelligent responsive macrophage cell membrane-camouflaged mesoporous silicon nanorod drug delivery system for precise targeted therapy of tumors.

Macrophage cell membrane-camouflaged nanocarriers can effectively reduce immune cell clearance and actively target tumors. In this study, a macrophage cell membrane-camouflaged mesoporous silica nanorod (MSNR)-based antitumor drug carrier equipped with a cationic polymer layer was developed. As drug carriers, these MSNRs were loaded with the thermosensitive phase change material L-menthol (LM), the chemotherapy drug doxorubicin (DOX) and the fluorescent molecule indocyanine green (ICG). The rod-like shape of the MSNRs was shown to enhance the penetration of the drug carriers to tumors. In the weakly acidic tumor microenvironment, the cationic polymer exhibited a proton sponge effect to trigger macrophage cell membrane coating detachment, promoting tumor cell uptake. Following nanocarrier uptake, ICG is heated by near-infrared (NIR) irradiation to make LM undergo a phase transition to release DOX and generate a synergistic effect of thermochemotherapy which kills tumor cells and inhibits tumor growth together with reactive oxygen species (ROS) produced by ICG. Overall, this nanohybrid drug delivery system demonstrates an intelligent cascade response, leads to tissue-cell specific targeting and improves drug release accuracy, thus proving to be an effective cancer therapy.

CPNE1 predicts poor prognosis and promotes tumorigenesis and radioresistance via the AKT singling pathway in triple-negative breast cancer.

Elevated expression of Copine 1 (CPNE1) has been observed in multiple cancers; however, the underlying mechanisms by which it affects cancer cells are unclear. We aimed to study the effect of CPNE1 on the tumorigenesis and radioresistance of triple-negative breast cancer (TNBC). Quantitative real-time polymerase chain reaction was used to detect the expression of CPNE1 in TNBC tissues and cell lines. Western blot, immunohistochemistry, and immunofluorescence were used to investigate the levels of CPNE1, p-AKT, AKT, cleaved caspase-3, cleaved PARP1, and γ-H2AX. Cell viability and apoptosis were measured by CCK-8 and flow cytometry, respectively. CPNE1 was overexpressed in TNBC tissues and cell lines and was associated with tumor size, distant metastases, and survival rates of patients with TNBC. Moreover, function study shows that CPNE1 promoted cell viability and inhibited cell apoptosis in vitro and inhibited the radiosensitivity of TNBC. Importantly, inactivation of AKT signaling inhibited the tumorigenesis and radioresistance mediated by CPNE1 in TNBC cells. In vivo xenograft study also shows that CPNE1 knockdown inhibited tumor growth and promoted cell apoptosis. Overall, our findings suggest that CPNE1 promotes tumorigenesis and radioresistance in TNBC by regulating AKT activation and targeted CPNE1 expression may be a strategy to sensitize TNBC cells toward radiation therapy.

Newcastle disease virus selectively infects dividing cells and promotes viral proliferation.

Newcastle disease virus (NDV) can select cells to infect, but the mechanism of its cell selectivity has not been comprehensively investigated. Here, we use HeLa cells to establish that NDV can selectively infect cells at the single-cell level. We labeled proliferating cells with 5'-bromo-2-deoxyuridine (BrdU) and examined the colocalization of BrdU with NDV in cells to clarify the relationships between NDV infection and cell proliferation. Receptors at the plasma membrane mediate NDV entry into host cells. We labeled sialic acid receptor isoforms, compared their densities between different cell types and measured the sialic acid receptor densities in different cell phases. Our results suggest that NDV displays host tropism to HeLa cells compared to BHK cells and that the differences in the receptor isoform expression patterns between cell types contribute to the selection of HeLa by NDV. At the single-cell level, the dynamics of receptor expression changes during different cell phases contributing to the selection of cells in S/G2 phase for NDV infection. Furthermore, cell proliferation benefits viral replication, and enhanced virus replication leads to increased damage to cells. The elucidation of the mechanisms underlying host cell selection by NDV may help in the screening and characterizing of additional candidate oncolytic virus strains.

Hemagglutinin-neuraminidase and fusion proteins of virulent Newcastle disease virus cooperatively disturb fusion-fission homeostasis to enhance mitochondrial function by activating the unfolded protein response of endoplasmic reticulum and mitochondrial stress.

The fusogenically activated F and HN proteins of virulent NDV induce complete autophagic flux in DF-1 and A549 cells. However, the effect of both glycoproteins on mitochondria remains elusive. Here, we found that F and HN cooperation increases mitochondrial biogenesis but does not cause the mitochondria damage. We observed that both glycoproteins change the morphological characteristics and spatial distribution of intracellular mitochondria. F and HN cooperate cooperatively to induce ER stress and UPRmt. Our preliminary data suggested that F and HN cooperatively disturb mitochondrial fusion-fission homeostasis to enhance mitochondrial biogenesis, and eventually meet the energy demand of syncytium formation.

Effect of flow velocity on the growth, stress and immune responses of turbot (Scophthalmus maximus) in recirculating aquaculture systems.

Land-based recirculating aquaculture systems (RAS) are widely utilized for turbot (Scophthalmus maximus) culture. Flow velocity in the tank is essential to maintain water quality, conservation of energy and fish welfare. However, little is known about how turbot respond to different velocities in the long term. In this study, water quality was kept constant, allowing the effect of flow velocity on the feeding intake, growth, plasma biochemical indexes, innate (non-specific) immunity and immune-related stress gene expressions in the skin to be examined in isolation in RAS. Turbot (average body length 20.10 cm) were reared for 60 days in RAS under three velocities, 0.06 m s-1, 0.18 m s-1, and 0.36 m s-1, corresponding to approximately 0.3 body length per second (bl s-1), 0.9 bl s-1 and 1.8 bl s-1, respectively. The results showed that at velocities of 0.36 m s-1 (1.8 bl s-1), juvenile turbot were subject to stress accompanied by a reduced growth rate. A velocity of 0.36 m s-1 was also found to significantly reduce SOD and GSH activity, and the concentration of total protein in plasma, while concentrations of urea nitrogen (BUN) and total bilirubin (TBIL) increased. There was an up-regulation of cathepsin D and lysozyme (LZM) in the skin at the highest velocity, implying the activation of stress and immune responses. At the medium velocity of 0.18 m s-1 (0.9 bl s-1), turbot increased their feed intake, obtained an elevated special growth rate (SGR), and exhibited significantly higher AKP and ACP activity in plasma. Overall, the results suggest that excessively high velocities are a stressor for turbot inducing an immune response in the skin, which is sensitive to environmental changes. A velocity of approximately 0.9 bl s-1 is suggested to promote growth and obtain better innate immunity of cultured turbot.

Measuring Mechanism and Applications of Polymer-Based Flexible Sensors.

A new type of flexible sensor, which could maintain the deformation consistency and achieve the real-time detection of the variation in load of the measured object, was proposed in this work. According to the principle of forced assembly, PDMS was used as the substrate of sensitive components and electrodes, while carbon fiber was added as a conductive medium to prepare a polymer-based flexible sensor, which effectively overcame the deformation limitation and output instability of conventional flexible sensors due to different substrates of sensitive components and the electrode. Combined with the sensor structure and the forced assembly method, a theoretical analysis of its conductive measurement mechanism was carried out. Meanwhile, an experimental test device was designed to test and analyze the output characteristics of the flexible sensor under a static and dynamic alternating load. The results show that the flexible sensor exhibited linear output under the dynamic alternating load of 10 kN to 60 kN and frequency of 3 Hz. Peak and valley value had the same phase with the load extremes. The dynamic and static experiments show that the resistance output signal and the sensitivity was in the range of 310~624.15 Ω and 171⁻183 N/Ω respectively. However, due to the hysteresis of the elastic recovery of the polymer, the output repeatability of the flexible sensor under the dynamic alternating load was 5.03% and 0.78% lower than that of the static load, respectively. Combined with the static and dynamic experiments, it was verified that the polymer-based flexible sensor can maintain the same deformation characteristics with the measured object, and at the same time outputted a resistance signal with a certain mapping relationship with the applied load. The repeatability of the output signal under dynamic and static experiments was within ±7%, which can meet the measurement requirements of the fatigue life of the measured body during periodic load.

Effects of a Sudden Drop in Salinity on Immune Response Mechanisms of Anadara kagoshimensis.

In this experiment, the effects of a sudden drop of salinity on the immune response mechanisms of the ark shell Anadara kagoshimensis were examined by simulating the sudden drop of salinity that occurs in seawater after a rainstorm. Additionally, the differentially expressed genes (DEGs) were identified using transcriptome sequencing. When the salinity dropped from 30‱ (S30) to 14‱ (S14), the phagocytic activity of blood lymphocytes, the O2- levels produced from respiratory burst, the content of reactive oxygen species, and the activities of lysozymes and acid phosphatases increased significantly, whereas the total count of blood lymphocytes did not increase. Total count of blood lymphocytes in 22‱ salinity (S22) was significantly higher than that in any other group. The raw data obtained from sequencing were processed with Trimmomatic (Version 0.36). The expression levels of unigenes were calculated using transcripts per million (TPM) based on the effects of sequencing depth, gene length, and sample on reads. Differential expression analysis was performed using DESeq (Version 1.12.4). Transcriptome sequencing revealed 269 (101 up-regulated, 168 down-regulated), 326 (246 up-regulated, 80 down-regulated), and 185 (132 up-regulated, 53 down-regulated) significant DEGs from comparison of the S14 vs. S22, S22 vs. S30, and S14 vs. S30 groups, respectively. Gene Ontology enrichment analysis of the DEGs in these salinity comparison groups revealed that the cellular amino acid metabolic process, the regulation of protein processing, the regulation of response to stress, and other terms were significantly enriched. Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that nucleotide-binding, oligomerization domain (NOD)-like receptor signaling pathway (ko04621), apoptosis-multiple species (ko04215), Toll and Imd signaling pathway (ko04624), NF-κB signaling pathway (ko04064), apoptosis (ko04210), and focal adhesion (ko04510) were significantly enriched in all salinity comparison groups. qRT-PCR verification of 12 DEGs in the above six pathways was conducted, and the results were consistent with the transcriptome sequencing results in terms of up-regulation and down-regulation, which illustrates that the transcriptome sequencing data are credible. These results were used to preliminarily explore the effects of a sudden drop of salinity on blood physiological and biochemical indexes and immunoregulatory mechanisms of A. kagoshimensis. They also provide a theoretical basis for the selection of bottom areas optimal for release and proliferation of A. kagoshimensis required to restore the declining populations of this species.

A cost-effective quasi-distributed liquid leakage sensor based on the polymer optical fiber and flexible lamp belt with LEDs.

A quasi-distributed liquid leakage (QDLL) sensor in local area is proposed and experimentally demonstrated, providing a real-time yet low-cost method than the existing local QDLL sensor. The sensor mainly consists of a flexible lamp belt (FLB) with light-emitting diodes (LEDs) and a polymer optical fiber (POF) processed with side-coupling structures. The side-coupling structures are illuminated by the LEDs one by one, forming a series of sensing probes. The lights are side-coupled into the POF through the side-coupling structure and pulse sequences are obtained from the power meters connected to the both ends of the POF. Each pulse represents a sensing probe, and the intensity of them increase when the coupling medium changes from air to liquid. The location of the leakage incident can be got by the position of each pulse in its output sequence. The influence of different side-coupling structures on side-coupling ratio are investigated. The experiment results validate the detection and localization abilities of the QDLL sensor along a 1 m-long POF with a spatial resolution of 0.1 m, which can be improved by adjusting the side-coupling structure. Furthermore, the temperature dependence is studied and can be compensated.

Newcastle disease virus V protein inhibits apoptosis in DF-1 cells by downregulating TXNL1.

Many viral proteins are related to suppressing apoptosis in target cells and are hence beneficial to viral replication. The V protein of Newcastle disease virus (NDV) is one such protein that plays an important role in inhibiting apoptosis in a species-specific manner. However, to date, there have been no reports clarifying the antiapoptotic mechanisms of the V protein. The present study was undertaken to determine the apoptotic potential of the V protein in a chicken embryo fibroblast cell line (DF-1 cell) and to elucidate its molecular mechanisms of action. Here, a yeast two-hybrid system was used to screen the host proteins that interact with the V protein and identified thioredoxin-like protein 1 (TXNL1) as a potential binding partner. Immuno-colocalization of V protein and TXNL1 protein in DF-1 cells further verified the interaction of the two proteins. Through the overexpression of TXNL1 protein and knockdown of TXNL1 protein in DF-1 cells, the effects of NDV replication and cell apoptosis were examined. Cell apoptosis was detected by flow cytometry. The mRNA and protein expression levels of Bax, Bcl-2 and Caspase-3 were detected by quantitative real-time PCR (Q-PCR) and Western blotting. NDV expression was detected by Q-PCR and plaque assay. The results revealed that the TXNL1 protein induced apoptosis and inhibited NDV replication in DF-1 cells. Furthermore, the Western blot and Q-PCR results suggested that TXNL1 induced cell apoptosis through a pathway involving Bcl-2\Bax and Caspase-3. Finally, this work provides insight into the mechanism by which the V protein inhibits apoptosis.

The effects of feeding Lactobacillus pentosus on growth, immunity, and disease resistance in Haliotis discus hannai Ino.

To study the effects of probiotic-added food on the survival and growth of abalone (Haliotis discus hannai Ino), the expression levels of nonspecific immune genes and the anti-Vibrio parahaemolyticus infection were examined. During an 8-week culturing experiment in an indoor aquarium and a 2-week V. parahaemolyticus artificial infection experiment, the control group was fed with untreated food once a day, while the experimental groups (L1, L2 and L3) were fed with Lactobacillus pentosus added food. The concentration of probiotics in the experimental food was 103 cfu/g (L1), 105 cfu/g (L2) and 107 cfu/g (L3), respectively. The results showed that the survival rate, shell length-specific growth rate, and the food conversion rate (FCR) of abalones in L1 and L2 were significantly higher than the control group. The food intake of abalones in L3 was significantly lower than that in L1, L2 and the control group, but there was no significant difference in FCR identified between L1, L2 and L3. In the L. pentosus-added groups, the total number of blood lymphocytes, lysozyme activity, acid phosphatase, superoxide dismutase, and expression levels of Mn-superoxide dismutase (Mn-SOD) and thioredoxin peroxidase (TPx) were significantly higher than the control group, while the malondialdehyde (MDA) content was significantly lower than the control group. The phagocytic activity of blood lymphocytes, catalase activity and the expression levels of heat shock protein 70 (HSP70) of abalones in the control group were significantly lower than that in L1 and L2, but there was no significant difference when compared with L3. The levels of O2-, NO produced by respiratory burst of blood lymphocytes and the expression levels of catalase (CAT) in L1 and L2 were significantly higher than both L3 and the control group. Seven days after infection with V. parahaemolyticus, all abalones in the control group were dead. After 14 days the cumulative mortality rate of abalones in the L. pentosus-added groups was significantly lower than that in the control group. Therefore, the 103 cfu/g and 105 cfu/g L. pentosus-added food not only promoted food intake and growth of abalones, but also improved their non-specific immunity and reduced V. parahaemolyticus infection, indicating that this strain is a good potential candidate for probiotic added food in the aquaculture industry.

Effects of a probiotic (Bacillus licheniformis) on the growth, immunity, and disease resistance of Haliotis discus hannai Ino.

To study the effects of a probiotic (Bacillus lincheniformis) on the survival and growth of Haliotis discus hannai Ino, the expression levels of nonspecific immune genes and the resistance to Vibrio parahaemolyticus infection were assessed. Abalones (shell length: 27.64 ±â€¯1.59 mm, body weight: 4.17 ±â€¯0.32 g) were selected for use in an 8-week culture experiment and a 2-week V. parahaemolyticus artificial infection experiment. In both experiments, the control group (C) was fed with a basal feed and the experimental groups were fed with experimental food prepared by spraying the probiotic on the basal feed at different concentrations: 103 (B1), 105 (B2), and 107 (B3) cfu/mL. The survival rate, total number of blood lymphocytes, activity of acid phosphatase, and expression level of heat shock protein 70 were significantly higher in B1, B2, and B3 than in C (P < 0.05). The specific growth rate of shell length, food intake, food conversion rate, phagocytic activity of blood lymphocytes, activities of myeloperoxidase and catalase (CAT), and expression levels of CAT and thioredoxin peroxidase of abalones in B2 were significantly higher than those in B1 and C (P < 0.05). Although the level of O2- produced by the respiratory burst of blood lymphocytes in B2 was not significantly different from those in B1 and B3, they were significantly higher than that in C (P < 0.05). The activity of superoxide dismutase (SOD), the nitric oxide levels produced by the respiratory burst of blood lymphocytes, and the expression levels of Mn-SOD in B1 and B3 were significantly higher than those in C but significantly lower than those in B2 (P < 0.05). Fourteen days after infection with V. parahaemolyticus, the cumulative mortality of abalones in B2 was significantly lower than those in B1 and C (P < 0.05). These results indicate that the food containing 105 cfu/mL Bacillus licheniformis promoted food intake and growth of abalones and also improved their resistance to V. parahaemolyticus infection. Thus, B. licheniformis is a good potential probiotic.

Localizing a gate in CFTR.

Experimental and computational studies have painted a picture of the chloride permeation pathway in cystic fibrosis transmembrane conductance regulator (CFTR) as a short narrow tunnel flanked by wider inner and outer vestibules. Although these studies also identified a number of transmembrane segments (TMs) as pore-lining, the exact location of CFTR's gate(s) remains unknown. Here, using a channel-permeant probe, [Au(CN)2](-), we provide evidence that CFTR bears a gate that coincides with the predicted narrow section of the pore defined as residues 338-341 in TM6. Specifically, cysteines introduced cytoplasmic to the narrow region (i.e., positions 344 in TM6 and 1148 in TM12) can be modified by intracellular [Au(CN)2](-) in both open and closed states, corroborating the conclusion that the internal vestibule does not harbor a gate. However, cysteines engineered to positions external to the presumed narrow region (e.g., 334, 335, and 337 in TM6) are all nonreactive toward cytoplasmic [Au(CN)2](-) in the absence of ATP, whereas they can be better accessed by extracellular [Au(CN)2](-) when the open probability is markedly reduced by introducing a second mutation, G1349D. As [Au(CN)2](-) and chloride ions share the same permeation pathway, these results imply a gate is situated between amino acid residues 337 and 344 along TM6, encompassing the very segment that may also serve as the selectivity filter for CFTR. The unique position of a gate in the middle of the ion translocation pathway diverges from those seen in ATP-binding cassette (ABC) transporters and thus distinguishes CFTR from other members of the ABC transporter family.

Liquid Level Measurement Model Outside of Closed Containers Based on Continuous Sound Wave Amplitude.

This research put forward an exogenous liquid level measurement method based on continuous sound wave amplitude. The distribution of round piston transducers in the sound field of a metal solid was analyzed by building 15 Multi-Gaussian Beam superposition models; the calculation method for echo sound pressure was worked out according to the reflection and refraction properties of ultrasonic wave. The continuous wave with three amplitudes was used as the driving source of ultrasonic sensor, and two single-crystal sensors with the same diameter were used as the transmitting terminal and receiving terminal of ultrasonic waves to carry out experiments for four groups of containers of different wall thickness and to compare the characteristics of echo energy of driving sources with three amplitudes above and below the liquid levels with different wall thickness. Two groups of sensors of different diameters were used to measure the liquid levels of experimental models, and the measuring errors of the two groups of sensors were analyzed and compared. The experimental result shows that the measuring error of the model is less than 5 mm, so it is applicable to the level measurement of liquids or liquid mixtures in many sectors.

Phylogenetic and pathogenic characterization of a pigeon paramyxovirus type 1 isolate reveals cross-species transmission and potential outbreak risks in the northwest region of China.

Pigeon paramyxovirus type-1 (PPMV-1) is enzootic in pigeons, causing severe economic loss in the poultry industry in many countries. However, the exact epidemic process of PPMV-1 transmission is still unclear. In this study, we analyzed the complete genome of the PPMV-1/SX-01/15 isolate. Sequence results show that the virus genome contains 15,192 nucleotides, with the gene order 3'-NP-P-M-F-HN-L-5'. Phylogenetic analysis revealed that this genome belongs to subgenotype VIc in class II. The mean death time (MDT) and intracerebral pathogenicity index (ICPI) were 62.4 h and 1.13, respectively, indicating that this isolate is a mesogenic PPMV-1 strain. To our knowledge, this is the first report of a subgenotype VIc mesogenic PPMV-1 strain circulating in commercial pigeon flocks in the northwest region of China. In a comparative infection experiment, the morbidity and mortality rates were 100% and 80%, respectively, in 4-week-old pigeons, whereas they were 50% and 30%, respectively, in 5-week-old chickens. Furthermore, this virus caused severe neurological symptoms in a 4-week-old pigeon and mild neurological symptoms in a 5-week-old chicken. A histopathological examination of the brain showed a classical nonsuppurative encephalitis lesion. The pattern of viral shedding, and viral load, and virus distribution differed between infected chickens and pigeons. Genomic characteristics suggest that there was cross-species transmission of PPMV-1 subgenotype VIc in this region at least from the years 2006 to 2015.