A memristive Chua's circuit regarded as a paradigm is reconsidered to exhibit its extreme multistability in this Letter. Memristor initial state-dependent dynamics is analysed and the coexistence of ...infinitely many attractors related to memristor initial states is revealed by numerical simulations and circuit simulations. The dynamical behaviour just reflects the emergence of extreme multistability in the memristive circuit.
This Letter presents a new second-order discrete map model, which is derived from a simple sampling switch-based memristor-capacitor circuit. The memristor-based map model has infinite unstable and ...critical stable fixed points, and exhibits chaotic and hyperchaotic behaviours via a period-doubling bifurcation scenario. These complex dynamical behaviours are confirmed by the phase portraits, iterative sequences and basins of attraction.
This paper investigates the projective synchronization of fractional-order memristor-based neural networks. Sufficient conditions are derived in the sense of Caputo’s fractional derivation and by ...combining a fractional-order differential inequality. Two numerical examples are given to show the effectiveness of the main results. The results in this paper extend and improve some previous works on the synchronization of fractional-order neural networks.
This Letter reports the finding of a point-cycle chaotic bursting phenomenon in a simple third-order memristive diode bridge-coupled Sallen-Key lowpass filter (LPF). By parallel coupling a ...generalised memristor composed of a diode bridge and an inductor into a Sallen-Key LPF a simple third-order memristive chaotic oscillator is established. With the modelling of this oscillator, stability analyses, numerical simulations and hardware experiments are performed, upon which the striking point-cycle chaotic bursting phenomenon is well demonstrated and effectively validated.
An improved memristive Chua's circuit is proposed, from which some hidden attractors are found. This memristive circuit has three determined equilibrium points, including a zero saddle point and two ...non-zero saddle-foci. The two non-zero saddle-foci are stable for the specified circuit element parameters, leading to the generation of hidden attractors and coexisting hidden attractors. Additionally, the observed hidden attractors are not sensitive to the initial conditions, which can easily be captured in a physical circuit by adjusting the circuit element parameters to the desired values.
Hidden attractors were reported to find in a normalised Chua's equation. To find the hidden attractors in a practical Chua's circuit, a modified Chua's diode is presented and its equivalent ...realisation circuit is designed. On the basis of proposed modified Chua's diode, a new Chua's circuit is rebuilt and hidden attractors under special initial conditions are captured by numerical simulations and circuit simulations.
Selenium (Se) is one of the essential trace elements in animal organisms with good antioxidant and immune-enhancing abilities. In this study, we investigated the effect and mechanism of Se deficiency ...on skeletal muscle cell differentiation. A selenium-deficient skeletal muscle model was established. The skeletal muscle tissue and blood Se content were significantly reduced in the Se deficiency group. HE staining showed that the skeletal muscle tissue had a reduced myofiber area and nuclei and an increased myofascicular membrane with Se deficiency. The TUNEL test showed massive apoptosis of skeletal muscle cells in Se deficiency. With Se deficiency, reactive oxygen species (ROS) and malondialdehyde (MDA) increased, and the activities of glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and catalase (CAT) were inhibited. In in vitro experiments, microscopic observations showed that the low-Se group had reduced C2C12 cell fusion and a reduced number of differentiated myotubes. In addition, qPCR results showed that differentiation genes (Myog, Myod, Myh2, Myh3, and Myf5) were significantly reduced in the low Se group. Meanwhile, Western blot analysis showed that the levels of differentiation proteins (Myog, Myod, and Myhc) were significantly reduced in the low-Se group. This finding indicates that Se deficiency reduces the expression of skeletal muscle cell differentiation factors. All the above data suggest that Se deficiency can lead to oxidative stress in skeletal muscle, resulting in a reduction in the differentiation capacity of muscle cells.
The free peroneal artery perforator (FPAP) flap is used for soft tissue defects after burns and trauma. However, the use of FPAP flaps to repair limb soft tissue defects for immediate reconstruction ...was rarely reported previously. Therefore, the purpose of this report is to evaluate free peroneal artery perforator flap to reconstruct traumatic limb soft tissue defects for immediate reconstruction.
A total of 25 cases of limb soft tissue defects undergoing immediate reconstruction of FPAP flap transfer were retrospectively evaluated from January 2019 to June 2019 in our institute. The locations of defects included the palm (10 cases), finger (5 cases), foot (7 cases), ankle (2 cases) and wrist (1 case). The sizes of defect varied from 3 × 2 cm to 15 × 7 cm (54.1 cm
in average). Flaps were harvested based on the peroneal perforator vessels, initially marked using hand-held Doppler.
Average size of harvested flap was 9.7 × 6.2 cm (ranging from 3.5 × 2 cm to 16 × 8 cm). All perforators were harvested from the peroneal artery and the arterial diameter ranged from 0.8 to 1.7 mm. The average pedicle length was 3.04 cm (range, 1.85-4.75 cm). Five vascular thrombosis were found including three cases of arterial thrombosis and two cases of venous thrombosis which were successfully salvaged by re-operation and vein graft. Satisfying functional outcome and acceptable appearance were achieved at 6 months or longer after surgery (range, 6-15 months, 12 months in average). All flaps survived at the end-point.
The FPAP flap is a reliable and thin fasciocutaneous flap, which can be used for repairing limb soft tissue defects. The FPAP flap can be used for covering defects with various appearances, locations, and sizes.
It is being debated whether prostate-specific antigen (PSA)-based screening effectively reduces prostate cancer mortality. Some of the uncertainty could be related to deficiencies in the age-based ...PSA cut-off thresholds used in screening. Current study considered 2779 men with prostate cancer and 1606 men without a cancer diagnosis, recruited for various studies in New Zealand, US, and Taiwan. Association of PSA with demographic, lifestyle, clinical characteristics (for cases), and the aldo-keto reductase 1C3 (AKR1C3) rs12529 genetic polymorphisms were analysed using multiple linear regression and univariate modelling. Pooled multivariable analysis of cases showed that PSA was significantly associated with demographic, lifestyle, and clinical data with an interaction between ethnicity and age further modifying the association. Pooled multivariable analysis of controls data also showed that demographic and lifestyle are significantly associated with PSA level. Independent case and control analyses indicated that factors associated with PSA were specific for each cohort. Univariate analyses showed a significant age and PSA correlation among all cases and controls except for the US-European cases while genetic stratification in cases showed variability of correlation. Data suggests that unique PSA cut-off thresholds factorized with demographics, lifestyle and genetics may be more appropriate for prostate cancer screening.
The Comment of Riaza is acknowledged. In response, it is argued that by establishing the complete corresponding relations between the voltage-current relation and the constitutive relation of ...memristors, the conclusions in the original Letter are appropriate. It is further illustrated that if the voltage-current model is used, the memristor is regarded as a dynamic element, whereas if the flux–charge model is utilised, the memristor is treated as a non-dynamic element. The results indicate that the memristor initial conditions described by the constitutive relation should be assigned in the modelling of memristive circuits, and the dynamic nature of memristors is related with the memristive circuit model.
PDF
