Soft Electrochemical Actuators with a Two-Dimensional Conductive Metal-Organic Framework Nanowire Array.

Electrically activated soft actuators capable of large deformation are powerful and broadly applicable in multiple fields. However, designing soft actuators that can withstand a high strain, provide a large actuation displacement, and exhibit stable reversibility are still the main challenges toward their practical application. Here, for the first time, we report a two-dimensional (2D) conductive metal-organic framework (MOF) based electrochemical actuator, which consists of vertically oriented and hierarchical Ni-CAT NWAs/CNF electrodes through the use of a facile one-step in situ hydrothermal growth method. The soft actuator prepared in this study demonstrated improvements in actuation performance and benefits from both the intrinsically ordered porous architecture and efficient transfer pathways for fast ion and electron transport; furthermore, this actuator facilitated a considerably high diffusion rate and low interfacial resistance. In particular, the actuator demonstrated a rapid response (<19 s) at a 3 V DC input, large actuation displacement (12.1 mm), and a correspondingly high strain of 0.36% under a square-wave AC voltage of ±3 V. Specifically, the actuator achieved a broad-band frequency response (0.1-20 Hz) and long-term cyclability in air (10000 cycles) with a negligible degradation in actuation performance. Our work demonstrates new opportunities for bioinspired artificial actuators and overcomes current limitations in electrode materials for soft robotics and bionics.

Fatty-acid Profiles and Fingerprints of Seven Types of Fish Roes as Determined by Chemometric Methods.

The fatty acids in seven species of fish roes were determined by GC-MS in combination with principal component and cluster analyses in order to derive their fatty-acid profiles and fingerprints. Twenty-three common chromatography peaks were identified in the fatty-acid fingerprints of the seven fish roes. A total of 19 typical fatty acids were identified in the fish roes studied. The fatty acid contents of the roes were significantly different, with saturated-fatty-acid contents in the seven roes ranging from 26.69% to 41.81%, and the unsaturated-fatty-acid contents ranging from 57.65% to 72.21%, the total EPA and DHA content (37.20%) is high in E. cypselurus roe, especially. The seven roe species were clearly distinguished according to fatty-acid composition and content by principal component analysis (PCA) and divided into two groups by cluster analysis (CA). PCA of the fatty acid data yielded three significant PCs , which together account for 94% of the total variance; with PC1 contributing 54% of the total.

Effect of lipid on surimi gelation properties of the three major Chinese carp.

BACKGROUND: Gel properties are important in determining the quality of surimi. In addition to myofibrillar proteins, lipids play an important role in the formation of surimi gel. Phospholipids (PL) are amphoteric lipids that cannot be removed through rinsing. Paradoxically, the addition of PL increases or decreases gel strength. This research aimed to investigate the effects of specific lipids on the gelation properties of surimi from three different carp. RESULTS: The hardness, chewiness, and gel strength of bighead carp (Aristichthys nobilis: BC) surimi were higher, and the total lipid content was lower when compared with grass carp (Ctenopharyngodon idellus: GC) and silver carp (Hypophthalmichthys molitrix: SC) surimi. Bighead carp surimi had lower levels of phosphatidylethanolamine (PE), phosphatidylinositols (PI), and phosphatidylcholine (PC), and higher phosphatidylserine (PS) and sphingomyelin (SM) content. The gelation properties of surimi increased with increasing concentrations of SM and PS. Furthermore, increased levels of saturated fatty acids (SFAs) and decreased levels of polyunsaturated fatty acids (PUFAs) increased gelation properties. Finally, higher hydrophobic interactions and more disulfide bonds were shown to increase gel network structure stability, resulting in improving gel strength in BC surimi. CONCLUSION: The textural characteristics and gel strength of surimi were dependent on the PL content, including total lipid levels and the types of fatty acids. This may account for previous conflicting reports on PL effects on gel strength. This study provides insight into how the texture of surimi can be improved and provides a starting point for further research. © 2020 Society of Chemical Industry.

Activities of Endogenous Lipase and Lipolysis Oxidation of Low-Salt Lactic Acid-Fermented Fish (Decapterus maruadsi).

There is increasing demand for low-salt meat products that retain traditional flavors. In this study, dry-salted fish (Decapterus maruadsi) were processed by 2 methods to obtain traditional salted fish (HS) and low-salt lactic acid-fermented fish (LAF). The relationship between lipolysis and lipid oxidation was investigated by evaluating changes in endogenous lipase (lipolytic enzymes; lipoxygenase, LOX), free fatty acid composition, thiobarbituric acid reactive substances (TBARS), and peroxide value (POV) during processing. Lipolytic enzyme activity showed a decreasing trend, in general. LOX activity initially increased and eventually decreased. Phospholipase, acid lipase, and neutral lipase activity was 0.33, 0.17, 0.57 (in HS) and 0.39, 0.25, 0.67 (in LAF) times in the final product than the activity levels observed in fresh fish. A principal component analysis indicated that phospholipase and neutral lipase play major roles in promoting lipid hydrolysis (in HS and LAF), the correlation between lipolytic activity and lipid oxidation in HS is greater than the correlation in LAF, and the contribution of LOX to lipid oxidation was minor in salted fish.

Trace Element Accumulation and Tissue Distribution in the Purpleback Flying Squid Sthenoteuthis oualaniensis from the Central and Southern South China Sea.

Sthenoteuthis oualaniensis is a species of cephalopod that is becoming economically important in the South China Sea. As, Cd, Cr, Cu, Hg, Pb, and Zn concentrations were determined in the mantle, arms, and digestive gland of S. oualaniensis from 31 oceanographic survey stations in the central and southern South China Sea. Intraspecific and interspecific comparisons with previous studies were made. Mean concentrations of trace elements analyzed in arms and mantle were in the following orders: Zn > Cu > Cd > Cr > As > Hg. In digestive gland, the concentrations of Cd and Cu exceed that of Zn. All the Pb concentrations were under the detected limit.

Effect of Ultrastructure on Changes of Textural Characteristics between Crisp Grass Carp (Ctenopharyngodon Idellus C.Et V) and Grass Carp (Ctenopharyngodon Idellus) Inducing Heating Treatment.

The research studies the ultrastructure effect on texture of crisp grass carp (CGC) and grass carp (GC) fillets inducing heating for 15, 25, and 40 min with boiling water. After heating, the hardness, fracturability, springiness, chewiness, resilience, and cohesiveness of CGC were higher than that of raw CGC, whereas the all textural characteristics of heating GC were lower obviously than that of raw GC. The hardness, fracturability, springiness, chewiness, resilience, and cohesiveness of CGC for heating 15 min were higher by 6.3%, 9.0%, 27.0%, 71.8%, 9.4%, and 23.9%, respectively, than that of raw CGC (RCGC). The hardness increasing of CGC flesh with the extension of heating time related closely to more coagulating connective tissue in interstitial spaces, especially relating to smaller muscle fiber diameter and denser muscle fiber density. The more and larger spaces between fiber and fiber with the extension of heating time results in the decrease of cohesiveness and resilience of CGC flesh. For chewiness, the stronger chewiness of cooked CGC associated with more detachment of myofiber-myocommata and fiber-fiber. Overall, the results show that the changes of texture characteristics of CGC fillet with extension of heating time correlates positively with the ultrastructure.

Damped oscillations in a multiple delayed feedback NF-κB signaling module.

The NF-[Formula: see text]B signaling system regulates a number of cellular processes. Recent studies with simplified models found a damped function of the dual delayed feedback NF-κB signaling module. We use a computational model to investigate how multiple delayed feedback aids achieving damping oscillation in the system and how internal noise can influence the damping function. A curve-fitting method (CFM) is introduced to quantify the damped oscillation. Our results show that (1) the structure of multiple delayed feedback, containing double or triple significantly delayed feedback, determines achieving damped oscillation. (2) Internal noise could aid the system to achieve damped oscillation under almost all circumstances.

Detection of white matter lesions in the acute stage of diffuse axonal injury predicts long-term cognitive impairments: a clinical diffusion tensor imaging study.

BACKGROUND: White matter disruption is known to contribute to neurocognitive deficits after diffuse axonal injury (DAI). This study evaluated the relationship between white matter integrity using diffusion tensor imaging in the early stage and cognitions in the chronic stage. METHODS: Diffusion tensor imaging was performed in 15 patients with DAI within 7 days of injury and in 15 patients in the control group. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were calculated within regions of interest, including the posterior limb of the internal capsule, uncinate fasciculus (UF), anterior corona radiate (ACR), superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), genu of the corpus callosum, body of the corpus callosum, and splenium of the corpus callosum and cingulum bundle (CB). The patients with DAI and the patients in the control group also underwent neuropsychological testing during the chronic stage after DAI. RESULTS: The region-of-interest analysis showed significantly reduced FA and AD values in all nine regions within 7 days of injury as well as increased MD values in the corpus callosum among patients in the DAI group. The patients demonstrated significantly poorer performance on the working memory tests and attention test. In patients, working memory function was positively correlated with the AD value in the UF and with the FA value in the CB, UF, SLF, and ILF. Working memory function was inversely correlated with the RD value in the CB, SLF, and ILF and with the MD value in the SLF and ILF. In addition, the attention function demonstrated a positive correlation with the RD value in the ACR, SLF, and ILF and with the MD value in the ACR, SLF, and ILF. In addition, attention was inversely correlated with the FA values for the posterior limb of the internal capsule, ACR, SLF, and ILF. CONCLUSION: The results indicated that the presence of white matter changes during the early stage of DAI may be helpful for predicting cognitive dysfunction over the long term. LEVEL OF EVIDENCE: Prognostic study, level III.

Segregation of large granules from close-packed cluster of small granules due to buoyancy.

Segregation of large granules in a vibrofluidized granular bed with inhomogeneous granular number density distribution is studied by an event-driven algorithm. Simulation results show that the mean vertical position of large granules decreases with the increase of the density ration of the large granules to the small ones. This conclusion is consistent with the explanation that the net pressure due to the small surrounding particle impacts balances the large granular weight, and indict that the upward movement of the large granules is driven by the buoyancy. The values of temperature, density, and pressure of the systems are also computed by changing the conditions such as heating temperature on the bottom and restitution coefficient of particles. These results indicate that the segregation of large granules also happen in the systems with density inversion or even close-packed cluster of particles floating on a low-density fluid, due to the buoyancy. An equation of state is proposed to explain the buoyancy.

Effects of a type of quenched randomness on car accidents in a cellular automaton model.

In this paper we numerically study the probability Pac of the occurrence of car accidents in the Nagel-Schreckenberg (NS) model with a defect. In the deterministic NS model, numerical results show that there exists a critical value of car density below which no car accident happens. The critical density Pc1 is not related only to the maximum speed of cars, but also to the braking probability at the defect. The braking probability at a defect can enhance, not suppress, the occurrence of car accidents when its value is small. Only the braking probability at the defect is very large, car accidents can be reduced by the bottleneck. In the nondeterministic NS model, the probability Pac exhibits the same behaviors with that in the deterministic model except the case of vmax=1 under which the probability Pac is only reduced by the defect. The defect also induces the inhomogeneous distribution of car accidents over the whole road. Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the nondeterministic NS model with vmax=1 in the case of large defect braking probability.

Effects of quenched randomness induced by car accidents on traffic flow in a cellular automata model.

In this paper we numerically study the impact of quenched disorder induced by car accidents on traffic flow in the Nagel-Schreckenberg (NS) model. Car accidents occur when the necessary conditions proposed by [J. Phys. A 30, 3329 (1997)]] are satisfied. Two realistic situations of cars involved in car accidents have been considered. Model A is presented to consider that the accident cars become temporarily stuck. Our studies exhibit the "inverse- lambda form" or the metastable state for traffic flow in the fundamental diagram and wide-moving waves of jams in the space-time pattern. Model B is proposed to take into account that the "wrecked" cars stay there forever and the cars behind will pass through the sites occupied by the "wrecked" cars with a transmission rate. Four-stage transitions from a maximum flow through a sharp decrease phase and a density-independent phase to a high-density jamming phase for traffic flow have been observed. The density profiles and the effects of transmission rate and probability of the occurrence of car accidents in model B are also discussed.