In the present study, we reported 18 LAB strains isolated from the intestinal contents of Cyprinus carpio, and their probiotic properties both in vitro and in vivo. The results showed that 9 of them ...had higher in vitro immunomodulatory properties, effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 0.5%) conditions, and inhibited the growth of 4 pathogens. Among them, Lactococcus lactis Q-8, Lactococcus lactis Q-9, and Lactococcus lactis Z-2 showed the strongest adhesion abilities and inhibition of pathogen adhesion to mucin. When the fish consumed diets containing these 3 strains (5 × 108 CFU/g) for 8 weeks, the weight gain (WG) and specific growth rate (SGR) had significantly (P < 0.05) increased, especially with L. lactis Q-8, which had a WG of 231.45%, and SGR of 2.22%. Survival rate in each LAB supplementation group was also significantly higher than that in control group during the feeding period (P < 0.05). For the cytokines expression levels in serum, different expression patterns were also observed. Before the infection with Aeromonas hydrophila, L. lactis supplementation significant up-regulated protein levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12) compared with negative (CK1) group, while these cytokines were significantly lower than those in positive (CK2) group after infection. However, whether infected or not, the expression of anti-inflammatory cytokines (IL-10, TGF-β) were significantly increased in L. lactis Q-8, L. lactis Q-9, and L. lactis Z-2 treatment groups. In conclusion, these 3 L. lactis strains screened from common carp were effective in improving growth, innate immunity and disease resistance. Based on the physiological characteristics in our study, they might be used as potential probiotics in aquaculture.
•Three strains L. lactis Q-8, Q-9 and Z-2 were isolated and screened from common carp intestinal.•These three L. lactis strains had higher in vitro immunomodulatory properties.•We prepared antibodies against cytokines and detected their expression at protein levels.•The single L. lactis-fed carp significantly improved innate immunity and growth performances.•L. lactis strains can enhance disease resistance against A. hydrophila in common carp.
Abstract
With the rapid expansion of industrial activities, chromium ions are discharged into the environment and cause water and soil pollution of various extents, which seriously endangers the ...natural ecological environment and human health. In this study, polyaniline/polyvinyl alcohol/amyloid fibril (PANI/PVA/AFL) composite gel beads (PPA) were prepared from polyaniline and amyloid fibrils with HCl as doping acid and PVA as a cross-linking agent. The results showed that PPA was an irregular composite bead with a diameter of 6 mm. The adsorption of Cr(VI) on the PPA gel beads followed the pseudo-second-order kinetics model, suggesting that chemical reactions were the controlling step in the Cr(VI) adsorption process. Though the Redlich–Peterson isotherm model had the best fit for the adsorption data, the isothermal adsorption process can be simplified using the Langmuir model. The maximum adsorption capacity for Cr(VI) in water was 51.5 mg g−1, comparable to or even higher than some PANI-based nanomaterials. Thermodynamic parameters showed that the adsorption process was a spontaneous, endothermic, and entropy-increasing process. Microscopic analysis revealed that the capture of Cr(VI) on PPA was mainly governed by electrostatic attraction, reduction, and complexation reactions. PPA can be used as a kind of effective remediation agent to remove Cr(VI) in water.
Force feedback gloves are promising for producing immersive haptic sensations in virtual reality systems or for intuitive control of remote robots in dexterous manipulation tasks. Existing gloves ...mainly adopt rigid actuators. In this article, we propose a force feedback glove using pneumatically powered fiber-reinforced soft bending actuators. Based on the unilateral deformable feature of the soft actuator, a dorsal-side mounted soft-rigid linkage mechanism is proposed to produce fingertip force feedback. We incorporated and experimentally determined a positive prebending deformation of the actuator to ensure small backdrive forces for simulating free-space sensation. To enable a large workspace of the glove, the soft-rigid linkage is synthesized to ensure full open/closure of the finger without any mechanical interference. Using a modular design concept, a three-fingered glove prototype is developed with a mass of 93.7 g. Experimental results show that the glove can provide distinct force feedback between free and constrained space. For free space, the maximum backdrive force is 0.48 N, while the fingertip force reaches up to 4.09 N for simulating the constrained space. Experiments also indicate that the glove is easy to put on/off . These results illustrate the feasibility of developing light-weighted force feedback gloves using fiber-reinforced soft bending actuators.
Force feedback gloves have found many applications in fields such as teleoperation and virtual reality. In order to enhance the immersive feeling of interaction with remote or virtual environments, ...glove-like haptic devices are used, which enable users to touch and manipulate virtual objects in a more intuitive and direct way via the dexterous manipulation and sensitive perception capabilities of human hands. In this survey, we aim to identify the gaps between existing force feedback gloves and the desired ones that can provide robust and realistic sensation of the interaction with diverse virtual environments. By examining existing force feedback gloves, the pros and cons of existing design solutions to the major sub-systems including sensing, actuation, control, transmission and structure are discussed. Future research topics are put forward with design challenges being elaborated. Innovative design solutions are needed to enable the utility of wearable haptic gloves in the upcoming virtual reality era.
Glucose plays a key role as an energy source in most mammals, but its importance in fish appears to be limited that so far seemed to belong to diabetic humans only. Several laboratories worldwide ...have made important efforts in order to better understand this strange phenotype observed in fish. However, the mechanism of carbohydrate/glucose metabolism is astonishingly complex. Why basal glycaemia is different between fish and mammals and how carbohydrate metabolism is different amongst organisms is largely uncharted territory. The utilization of comparative systems biology with model vertebrates to explore fish metabolism has become an essential approach to unravelling hidden in vivo mechanisms.
In this study, we first built a database containing 791, 593, 523, 666 and 698 carbohydrate/glucose metabolic genes from the genomes of Danio rerio, Xenopus tropicalis, Gallus gallus, Mus musculus and Homo sapiens, respectively, and most of these genes in our database are predicted to encode specific enzymes that play roles in defined reactions; over 57% of these genes are related to human type 2 diabetes. Then, we systematically compared these genes and found that more than 70% of the carbohydrate/glucose metabolic genes are conserved in the five species. Interestingly, there are 4 zebrafish-specific genes (si:ch211-167b20.8, CABZ01043017.1, socs9 and eif4e1c) and 1 human-specific gene (CALML6) that may alter glucose utilization in their corresponding species. Interestingly, these 5 genes are all carbohydrate regulation factors, but the enzymes themselves are involved in insulin regulation pathways. Lastly, in order to facilitate the use of our data sets, we constructed a glucose metabolism database platform ( http://101.200.43.1:10000/ ).
This study provides the first systematic genomic insights into carbohydrate/glucose metabolism. After exhaustive analysis, we found that most metabolic genes are conserved in vertebrates. This work may resolve some of the complexities of carbohydrate/glucose metabolic heterogeneity amongst different vertebrates and may provide a reference for the treatment of diabetes and for applications in the aquaculture industry.
•Precision nutrition involves ‘precision feeding’, ‘precision metabolism’, ‘precision output’ and ‘precision support’ theoretically and systematically.•This review intends to elaborate the concept ...evolution, theoretical system, and composition of the technical system of precision nutritional regulation.•Especially, we summarized the pathway and regulation of nutrients including protein, carbohydrate and lipid metabolism in fish.
Recently, the concept of precision nutrition has emerged in aquaculture, and there is increasing discussion on this topic. Some researchers have defined precision nutrition as precision feeding, which means that the nutrient contents of feed should meet the requirements for an animal’s optimal production performance and achieve minimum fodder waste at the same time. In practice, precision nutrition should include a comprehensive survey of the animal’s genetic background, living habits, metabolic characteristics, water ecological environment and other factors. Precision nutritional regulation covers every level, from genes, cells, and tissues to the whole organism. Through interacting with genes, nutrients activate or inhibit signalling pathways/networks within cells, which regulate gene expression and protein synthesis and subsequently affect the composition, content and deposition sites of carbohydrates, lipids, proteins and trace elements. Therefore, we propose that precision nutritional intervention needs to be carried out from the perspectives of ‘precision feeding’, ‘precision metabolism’, ‘precision output’ and ‘precision support’ simultaneously. This review intends to elaborate the concept evolution, theoretical system, and composition of the technical system, together with other aspects of precision nutritional regulation. This knowledge will provide a theoretical reference for the sustainable development of the aquaculture industry and the harvesting of quality products.
•We propose a variable motion mapping method to provide the operator more identifiable stiffness perception of the remote object.•We regulate the motion mapping coefficient according to the object ...stiffness so that the feedback stiffness in the master side is refine accordingly.•The variable motion mapping method allows operators to identify remote objects even without the knowledge of the exact stiffness values.•Discrimination and identification experiments conducted on a BarrettHand teleoperation system demonstrated that the variable motion mapping method can enhances the discrimination and identification of object stiffness in the robot hand teleoperation.
In robot hand teleoperation system, force feedback is critical for operator to perceive the physical property of grasped objects. However, it is challenging to implement accurate force feedback if the force accuracy of a haptic device is limited. This paper proposes a variable motion mapping method to enhance stiffness discrimination of the remote object. In this method, the motion mapping coefficient is regulated according to the object stiffness so that the operator can perceive the stiffness difference of the remote objects. To validate the proposed approach, we conducted two experiments on a three-finger robot hand (BarrettHand BH8-280) teleoperation system. In the first experiment, we measured the minimum relative change in feedback stiffness that could be detected by the operator. The result shows that the relative change should be 70% for a correct detection rate of about 91%. Based on the result, the motion mapping coefficient was selected for the system. In the second experiment, the variable motion mapping method was compared to a constant motion mapping method. The experimental task in the comparison is identifying four objects through stiffness perception alone. The experimental results show that the variable motion mapping method enhances the discrimination of the objects. The operator can identify individual object within a group of four without visual feedback with the variable motion mapping method.
The primary function of the nucleolus is ribosome biogenesis, which is an extremely energetically expensive process. Failures in ribosome biogenesis cause nucleolar stress with an altered energy ...status. However, little is known about the underlying mechanism linking nucleolar stress to energy metabolism. Here we show that nucleolar stress is triggered by inactivation of RSKS-1 (ribosomal protein S6 kinase), RRP-8 (ribosomal RNA processing 8), and PRO-2/3 (proximal proliferation), all of which are involved in ribosomal RNA processing or inhibition of rDNA transcription by actinomycin D (AD), leading to excessive lipid accumulation in Caenorhabditis elegans. The transcription factor PHA-4/FoxA acts as a sensor of nucleolar stress to bind to and transactivate the expression of the lipogenic genes pod-2 (acetyl-CoA carboxylase), fasn-1 (fatty acid synthase), and dgat-2 (diacylglycerol O-acyltransferase 2), consequently promoting lipid accumulation. Importantly, inactivation of pha-4 or dgat-2 is sufficient to abolish nucleolar stress-induced lipid accumulation and prolonged starvation survival. The results revealed a distinct PHA-4-mediated lipogenesis pathway that senses nucleolar stress and shifts excessive energy for storage as fat.
The perception of voluntary respiratory consciousness is quite important in some situations, such as respiratory assistance and respiratory rehabilitation training, and the key signatures about ...voluntary respiration control may lie in the neural signals from brain manifested as electroencephalography (EEG). The present work aims to explore whether there exists correlation between voluntary respiration and scalp EEG. Evoke voluntary respiration of different intensities, while collecting EEG and respiration signal synchronously. Data from 11 participants were analyzed. Spectrum characteristics at low-frequency band were studied. Computation of EEG-respiration phase lock value (PLV) and EEG sample entropy were conducted as well. When breathing voluntarily, the 0-2 Hz band EEG power is significantly enhanced in frontal and right-parietal area. The distance between main peaks belonging to the two signals in 0-2 Hz spectrum graph tends to get smaller, while EEG-respiration PLV increases in frontal area. Besides, the sample entropy of EEG shows a trend of decreasing during voluntary respiration in both areas. There's a strong correlation between voluntary respiration and scalp EEG. Significance: The discoveries will provide guidelines for developing a voluntary respiratory consciousness identifying method and make it possible to monitor people's intention of respiration by noninvasive BCI.
To improve the ride comfort of electric vehicle, the vertical dynamic model of electric vehicle is established under the excitation of road surface and wheel hub motor. The road excitation is divided ...into random continuous road and convex road, and the influence of motor electromagnetic excitation on vibration is analyzed. To avoid the empirical value influence of each index weight coefficient on the main vibration control, the weight coefficient is determined by analytic hierarchy process (AHP), the LQG controller of vehicle active suspension is designed by using optimal control theory, and the comprehensive optimization of performance index is realized. The effectiveness of control effect is verified by comparing active and passive control based on single and double excitation.
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