The force developed by actively lengthened muscle depends on different structures across different scales of lengthening. For small perturbations, the active response of muscle is well captured by a linear-time-invariant (LTI) system: a stiff spring in parallel with a light damper. The force response of muscle to longer stretches is better represented by a compliant spring that can fix its end when activated. Experimental work has shown that the stiffness and damping (impedance) of muscle in response to small perturbations is of fundamental importance to motor learning and mechanical stability, while the huge forces developed during long active stretches are critical for simulating and predicting injury. Outside of motor learning and injury, muscle is actively lengthened as a part of nearly all terrestrial locomotion. Despite the functional importance of impedance and active lengthening, no single muscle model has all these mechanical properties. In this work, we present the viscoelastic-crossbridge active-titin (VEXAT) model that can replicate the response of muscle to length changes great and small. To evaluate the VEXAT model, we compare its response to biological muscle by simulating experiments that measure the impedance of muscle, and the forces developed during long active stretches. In addition, we have also compared the responses of the VEXAT model to a popular Hill-type muscle model. The VEXAT model more accurately captures the impedance of biological muscle and its responses to long active stretches than a Hill-type model and can still reproduce the force-velocity and force-length relations of muscle. While the comparison between the VEXAT model and biological muscle is favorable, there are some phenomena that can be improved: the low frequency phase response of the model, and a mechanism to support passive force enhancement.

We demonstrated the coexistence of memresistance, memcapacitance, and meminductance non-volatile bipolar analog resistive switching in Cu (top electrode)/CuO (active layer)/ SS (bottom electrode) memory devices with and without the presence of the light. The onset of memcapacitance and meminductance is noticed from the pinched-shaped characteristics in the first and third quadrants. The variation in the scan rate also impacts the coexistence characteristics by shifting the intercept point for low resistance (LRS) and high resistance (HRS) states in positive and negative biasing voltages.  The durability and retention are measured over a period of 150 cycles and 1500 s with and without light illumination. The Weibull slope for set/reset state with and without light are 106.80/114.23 and 70.21/102.25, respectively, suggesting that stability of the device increases with light illumination. Interestingly, the memcapacitance disappears after 600 cycle and after 60 . The double logarithmic I-V characteristics suggest the trap assisted conduction (higher slope > 2) in the higher external electric field, and Ohmic behaviour in the lower applied field region. Thus, the present study provides a way for low power electronics and photoresistors together with memresistance, memcapacitance, and meminductance, simultaneously, i.e., MEMRIC in a single device.

UNASSIGNED: Fontan procedure, the standard surgical palliation to treat children with single ventricular defects, causes systemic complications over years due to lack of pumping at cavopulmonary junction. A device developed specifically for cavopulmonary support is thus considered, while current commercial ventricular assist devices (VAD) induce high shear rates to blood, and have issues with paediatric suitability.
UNASSIGNED: To demonstrate the feasibility of a small, valveless, non-invasive to blood and pulsatile rotary pump, which integrates impedance and peristaltic effects.
UNASSIGNED: A prototype pump was designed and fabricated in-house without any effort to optimise its specification. It was then tested in vitro, in terms of effect of pumping frequency, background pressure differences and pump size on output performance.
UNASSIGNED: Net flow rate (NFR) and maximum pressure head delivery are both reasonably linearly dependent on pumping frequency within normal physiological range. Positive linearity is also observed between NFR and the extent of asymmetric pumping. The device regulates NFR in favourable pressure head difference and overcomes significant adverse pressure head difference. Additionally, performance is shown to be insensitive to device size.
UNASSIGNED: The feasibility of the novel rotary pump integrating impedance and peristaltic effects is demonstrated to perform in normal physiological conditions without any optimisation effort. It provides promising results for possible future paediatric cavopulmonary support and warrants further investigation of miniaturisation and possible haemolysis.

Campylobacter jejuni is a common foodborne pathogen found in poultry that can cause severe life-threatening illnesses in humans. It is important to detect this pathogen in food to manage foodborne outbreaks. This study reports a novel impedimetric phage protein-based biosensor to detect C. jejuni NCTC 11168 at 100 CFU/mL concentrations using a genetically engineered receptor-binding phage protein, FlaGrab, as a bioreceptor. The electrochemical impedance spectroscopy (EIS) technique was employed to measure changes in resistance upon interaction with C. jejuni. The sensitivity of the phage protein-immobilized electrode was assessed using the various concentrations of C. jejuni NCTC 11168 ranging from 102-109 colony forming units (CFU)/mL). The change transfer resistance of the biosensor increased with increasing numbers of C. jejuni NCTC 11168 cells. The detection limit was determined to be approximately 103 CFU/mL in the buffer and 102 CFU/mL in the ex vivo samples. Salmonella enterica subsp. enterica serotype Typhimurium-291RH and Listeria monocytogenes Scott A were used as nontarget bacterial cells to assess the specificity of the developed biosensor. Results showed that the developed biosensor was highly specific toward the target C. jejuni NCTC 11168, as no signal was observed for the nontarget bacterial cells.

Orthoflaviviruses cause a major threat to global public health, and no antiviral treatment is available yet. Zika virus (ZIKV) entry, together with many other viruses, is known to be enhanced by phosphatidylserine (PS) receptors such as T-cell immunoglobulin mucin domain protein 1 (TIM-1). In this study, we demonstrate for the first time, using cell-based electrical impedance (CEI) biosensing, that ZIKV entry is also enhanced by expression of CD300a, another PS receptor. Furthermore, inhibiting CD300a in immature monocyte-derived dendritic cells partially but significantly inhibits ZIKV replication. As we have previously demonstrated that CEI is a useful tool to study Orthoflavivirus infection in real time, we now use this technology to determine how these PS receptors influence the kinetics of in vitro ZIKV infection. Results show that ZIKV entry is highly sensitive to minor changes in TIM-1 expression, both after overexpression of TIM-1 in infection-resistant HEK293T cells, as well as after partial knockout of TIM-1 in susceptible A549 cells. These results are confirmed by quantification of viral copy number and viral infectivity, demonstrating that CEI is highly suited to study and compare virus-host interactions. Overall, the results presented here demonstrate the potential of targeting this universal viral entry pathway.

Herein, the standard solid-state reaction process was employed to synthesize the polycrystalline Ba1-xDy2x/3Ti0.98Mn0.02O3 (x = 0.0000-0.0085) ceramics and each composition was sintered at 1200 °C for 3 h. The structural, morphological, electrical, and magnetic properties were carried out by the X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), impedance analyzer, and vibrating sample magnetometer (VSM) to investigate the influence of doping of Dy 3+ (low concentration) and Mn4+ in BaTiO3 simultaneously. The XRD study confirmed the formation of perovskite structure with tetragonal symmetry of the prepared solid solution. The magnitude of the porosity (P%) decreased from 13.22 to 9.49 with increasing content of Dy and x = 0.0080 sample showed the lowest value. The mean grain size was estimated in the micrometer range, with values ranging from 0.5713 to 0.1457 μm. The highest grain size determined for the x = 0.0070 sample was 0.5713 μm. The Brunauer-Emmett-Teller (BET) adsorption isotherm measurements were used to estimate the specific surface area; the result was 24.181 m2/g for x = 0.007 composition. For the compound with x = 0.0070 the maximum recorded dielectric constant was found to be 6 × 103 at 103 Hz. A relatively lower dielectric loss (<5 %) was observed. The Nyquist plot illustrated that only the grain boundary effect is significant for the conduction process in the studied compositions. The present solid solution revealed better magnetic results compared to other reported ceramics similar to the prepared constituents. The optimum value of saturation magnetization (0.371 emu/g) was obtained for x = 0.0080 composition. Among the synthesized Dy doped samples x = 0.0075 composition displayed a significant complex initial permeability ( μ i / ). An enhanced relative quality factor (RQF) was seen with increasing frequency and the highest relative quality factor was noticed (>100) for the x = 0.0075 sample at 108 Hz. The studied materials could be employed as an environmentally acceptable alternative to the hazardous lead (Pb)-based multiferroic substance.

OBJECTIVE: The objective of this study is to expand on a novel method for semioccluded vocal tract therapy (SOVT) called controlled supraglottic pressure phonation, and investigate the mechanism that introduced supraglottic pressure mediates a decrease in impedance during SOVT therapy. Instead of the previously used CPAP mask, this study analyzes controlled supraglottic pressure phonation by use of a straw mouthpiece to deliver supraglottic pressure.
METHODS: Twenty-six human subjects were randomly assigned to one of four supraglottic pressure levels: 0, 2, 4, and 6 cm H2O, which were controlled through a continuous positive airway pressure device. Subjects were asked to phonate during a SOVT task for one round (referred to as the \"short-duration\" task) and eight rounds (referred to as the \"long-duration\" task), in which acoustic and aerodynamic properties were measured before and after. Subjects were surveyed for the levels of discomfort experienced during controlled supraglottic pressure phonation therapy and subjective levels of improvement of vocal economy.
RESULTS: Significant differences were observed between pre- and post-task measurement for phonation threshold pressure for the long-duration task for the 2 cmH2O group. Frequency measurement was not found to have statistically significant differences. The perceived phonatory effort was not significantly different at any pressure levels.
CONCLUSIONS: Lower supraglottic pressure levels will improve ease of phonation for longer durations, however, shorter-duration tasks will not be effective. Controlled supraglottic pressure phonation coupled with straw phonation may produce an improved vocal economy for those who have access to an oppositional airflow setup.

Gastroesophageal reflux disease (GERD) is the most prevalent gastrointestinal disorder posing diagnostic and therapeutic challenges. Diagnosis should be objectively defined with endoscopy and pH testing, while novel metrics may augment diagnosis for inconclusive GERD cases, including the postreflux swallow-induced peristaltic wave index and esophageal mucosal impedance. Conditions that overlap with or mimic GERD should be considered such as achalasia, rumination, and eosinophilic esophagitis. Genetic testing for proton pump inhibitor metabolism is an option for precision therapy in complex persistent GERD. Proton pump inhibitor refractory GERD may require medical, surgical, or endoscopic therapies. The presence of GERD should be objectively evaluated in achalasia patients treated with peroral endoscopic myotomy, and further studies are needed to determine timing of this evaluation. Patients with scleroderma are at a high risk for GERD owing to abnormal esophageal motility and should be managed with aggressive medical therapy and lifestyle changes given the high prevalence of esophagitis and Barrett\'s esophagus in this population. Further studies are needed to understand the complex mechanisms of GERD in idiopathic pulmonary fibrosis and lung transplantation.

暂无摘要。

In this investigation, our primary objective is to explore the structural, morphological, and electrical characteristics of Bi0.75Ba0.25(FeMn)0.5O3 ceramic material synthesized by the sol-gel method. The prepared sample underwent synthesis through the conventional sol-gel technique. Examination through X-ray diffraction (XRD) unveiled a well-defined rhombohedral structure within the R3´C space group. Moreover, to evaluate the purity and nano-grain morphology, we utilized energy dispersive spectroscopy (EDX) and scanning electron microscopy (SEM). Electrical assessments were carried out over a frequency span of 100 Hz to 1 MHz and temperatures ranging from 200 to 340 K. Employing the correlated barrier hopping (CBH) model, we analyzed the AC conductivity of our specimen. The activation energy, determined from both DC conductivity and impedance spectra, demonstrated close correspondence, suggesting that both conductivity and r laxation processes are influenced by similar factors. Notably, the dielectric properties hold significant importance, potentially rendering our sample suitable for electronic applications. Furthermore, we calculated thermodynamic parameters, such as enthalpy (ΔH), entropy change (ΔS), and free energy of activation (ΔF), offering deeper insights into the material\'s behavior and conductivity mechanisms.