Spatial coherence resonance on diffusive and small-world networks of Hodgkin-Huxley neurons

Spatial coherence resonance in a spatially extended system that is locally modeled by Hodgkin-Huxley (HH) neurons is studied in this paper. We focus on the ability of additive temporally and spatially uncorrelated Gaussian noise to extract a particular spatial frequency of excitatory waves in the medium, whereby examining also the impact of diffusive and small-world network topology determining the interactions amongst coupled HH neurons. We show that there exists an intermediate noise intensity that is able to extract a characteristic spatial frequency of the system in a resonant manner provided the latter is diffusively coupled, thus indicating the existence of spatial coherence resonance. However, as the diffusive topology of the medium is relaxed via the introduction of shortcut links introducing small-world properties amongst coupled HH neurons, the ability of additive Gaussian noise to evoke ordered excitatory waves deteriorates rather spectacularly, leading to the decoherence of the spatial dynamics and with it related absence of spatial coherence resonance. In particular, already a minute fraction of shortcut links suffices to substantially disrupt coherent pattern formation in the examined system.Comment: 8 two-column pages, 6 figures; accepted for publication in Chao

A Strategy for Modelling Mechanochemically Induced Unzipping and Scission of Chemical Bonds in Double-Network Polymer Composite

A molecular mechanics model for covalent and ionic double-network polymer composites was developed in this study to investigate mechanisms of mechanochemically induced unzipping and scission of chemical bonds. Morse potential function was firstly applied to investigate mechanical unzipping of the covalent bonds, and then stress-dependent mechanical energy for the interatomic covalent bonds was discussed. A new mechanochemical model was formulated for describing the mechanically induced ionic bond scissions based on the Morse potential model and equations for electrostatic forces. Based on this newly proposed model, mechanochemical behaviors of several common interatomic interaction types (e.g., A+B-, A2+B2-/A2+2B-/2A+B2- and A3+B3-/A3+3B-/3A+B3-) of the ionic bonds have been quantitatively described and analyzed. Finally, mechanochemical unzipping of the covalent bonds and dissociation of the ionic bonds have been characterized and analyzed based on the molecular mechanics model, which has well predicted the chemical and mechanochemical activations in the covalent and ionic double-network polymer composites

Power Transformer fault Diagnosis based on Hybrid Intelligent Algorithm

The gas content in the oil is used as the fault input characteristic for the power transformer. Still, the accuracy of the diagnosis results is not ideal, and such a model is unstable. This research proposes a hybrid intelligent fault diagnosis method based on the improved grey wolf algorithm and an optimized probabilistic neural network. Firstly, a strategy of three nonlinear control factors is introduced to fit the grey wolves’ search process. The weighted distance was modified to update the position information of grey wolf elements to avoid the algorithm falling into the local optimum. Secondly, the performance of the improved grey wolf algorithm was tested through six commonly used functions. The results show that the improved grey wolf algorithm has high convergence accuracy and stability in both multimodal and unimodal functions. Finally, the improved grey wolf algorithm and the probabilistic neural network were combined to diagnose the oil-immersed power transformer through hybrid intelligent algorithms. As a result, the fault diagnosis model proved valid for transformer fault diagnosis

A phenomenological model for dynamic response of double-network hydrogel composite undergoing transient transition

We present a phenomenological model for dynamic deformation and mechanical response of double-network (with short-chained ionic network and long-chained covalent network) hydrogel composite based on theory of transient networks. Molecular structures and stress-strain relations of the hydrogel composite were investigated based on thermomechanical properties of the individual network. Constitutive relations were derived for its nonlinear viscoelastic responses and annihilation/reformation rates of active short chains were determined by means of Eyring formula. An extended Volokh model was proposed to separate effects of large strain hysteresis and anomalous viscoelastic relaxation on the hydrogel composite after strain reversal. Experimental results from rate-independent tests are well in agreement with that of the numerical simulations. This study provides a fundamental simulation tool for modelling and predicting mechanics and mechanisms of viscoelastic response and mechanical responses in double-network hydrogel composite

Izraženost surfaktantnog proteina B u bronhoalveolarnom ispirku terminske novorođenčadi sa sindromom respiracijskog distresa

The aim was to investigate the surfactant protein B (SP-B) expression in the bronchoalveolar lavage fluid (BALF ) of full-term neonates with respiratory distress syndrome (RD S). The enzyme-linked immunosorbent assay was performed to assess SP-B expression in BALF of 60 full-term neonates with RD S and 23 healthy neonates and correlation of SP-B level with RD S classification according to chest x-ray findings and PaO2/FiO2 before mechanical ventilation in neonates with RD S. The SP-B level was significantly lower in the RD S group (17.63±6.80 ng/mL) than in healthy neonates (103.95±6.38 ng/mL) (P<0.001). The SP-B level correlated positively with PaO2/ FiO2 before mechanical ventilation (r=0.838, P<0.001). Moreover, the lower the SP-B level, the more severe was the RD S as determined by chest x-ray (P<0.001). In conclusion, full-term neonates with RD S had reduced SP-B in BALF , which was related to the severity of RD S, suggesting that SP-B supplement may be an effective strategy in the treatment of RD S in full-term neonates.Cilj studije bio je ispitati izraženost surfaktantnog proteina B (SP-B) u bronhoalveolarnom ispirku (BALF ) terminske novorođenčadi sa sindromom respiracijskog distresa (SRD ). Izraženost SP-B određena je testom ELI SA u BALF 60 terminske novorođenčadi sa SRD i 23 zdrave novorođenčadi. Utvrđena je korelacija razine SP-B s klasifikacijom SRD prema rendgenskoj snimci prsišta i vrijednosti PaO2/FiO2 prije mehaničke ventilacije u novorođenčadi sa SRD . U skupini novorođenčadi sa SRD razina SP-B bila je značajno niža (17,63±6,80 ng/mL) od one u zdrave novorođenčadi (103,95±6,38 ng/ mL) (P<0,001). Utvrđena je pozitivna korelacija razine SP-B i PaO2/FiO2 prije mehaničke ventilacije (r=0,838, P<0,001). Štoviše, što je bila niža razina SP-B, to je teži bio SRD procijenjen prema rendgenskoj snimci prsišta (P<0,001). Zaključuje se da terminska novorođenčad sa SRD ima sniženu razinu SP-B u BALF i to je povezano s težinom SRD . Ovi nalazi ukazuju na to da bi dodatak SP-B mogla biti učinkovita strategija u liječenju SRD kod terminske novorođenčadi

Diosgenin inhibits cell proliferation of primary human thyrocytes via downregulation of PI3K/Akt signaling pathway

Purpose: To determine the potential influence of diosgenin on proliferation of human thyrocytes and its possible mechanism.Methods: Primary human thyrocytes were cultured and treated with diosgenin at various time intervals. Anti-proliferative activity was determined by MTT assay. Cell proliferation was evaluated by EdU assay while cell cycle was analyzed using fluorescence-activated cell sorting (FACS) method. Protein expression of p21 (CIP1), p27 (KIP1), cyclins, protein kinase B (Akt), phosphatidylinositol 3 kinase (PI3K) and p-Akt was determined by the western blot.Results: Diosgenin inhibited proliferation of primary human thyrocytes and caused G0/G1 arrest in a concentration-dependent manner. It also downregulated cyclin D1 and phosphorylation of PI3K and Akt, but upregulated p21 and p27.Conclusion: Inhibition of proliferation of primary human thyrocytes by diosgenin occurs viadownregulation of PI3K/Akt signaling pathway. Therefore, diosgenin can be developed as a potential drug for the treatment of thyroid disease.Keywords: Diosgenin, Proliferation, Primary human thyrocytes, PI3K/Akt signaling pathwa

The Protective Effect of Yi Shen Juan Bi Pill in Arthritic Rats with Castration-Induced Kidney Deficiency

Androgens have been linked to the onset, severity, and progression of rheumatoid arthritis (RA). In traditional Chinese medicine (TCM), the most common pattern in RA is kidney deficiency, which partly corresponds to a low sex hormone state. In this study, TCM kidney deficiency was induced in male Sprague-Dawley rats with castration surgery, and a TCM preparation, Yi Shen Juan Bi Pill (YJB), was used to treat collagen induced arthritis (CIA) rats with castration. Metabolomic technique was used to evaluate the pharmacological mechanism in castrated CIA rats treated by YJB. The results showed that castration significantly increased the severity of the arthritis in rats but was ameliorated by YJB. Its pharmacological mechanism was partially associated with lipid metabolites involving free fatty acid (FFA) and lysophosphatidylcholine (LPC). In conclusion, the experimental results demonstrate the protective effect of YJB on the TCM kidney deficiency pattern induced by androgen deficiency in CIA rats and support that YJB should be used for the clinical treatment of RA with TCM kidney deficiency pattern