A Flexible PVDF-based Platform Combining Acoustofluidics and Electromagnetic Metamaterials

Acoustofluidic devices have been demonstrated effectively for liquid manipulation functionalities. Likewise, electromagnetic metamaterials have been employed as highly sensitive and wireless sensors. In this work, we introduced a new design combining the concepts of acoustofluidics and electromagnetic metamaterials on a single device realised on a flexible PVDF substrate. We characterise the operation of the device at acoustic and microwave frequencies. The device can be used in wearable biosensors with integrated liquid sampling and continuous wireless sensing capabilities

Real-Time Gait Phase Detection on Wearable Devices for Real-World Free-Living Gait

Detecting gait phases with wearables unobtrusively and reliably in real-time is important for clinical gait rehabilitation and early diagnosis of neurological diseases. Due to hardware limitations of microcontrollers in wearable devices (e.g., memory and computation power), reliable real-time gait phase detection on the microcontrollers remains a challenge, especially for long-term real-world free-living gait. In this work, a novel algorithm based on a reduced support vector machine (RSVM) and a finite state machine (FSM) is developed to address this. The RSVM is developed by exploiting the cascaded K-means clustering to reduce the model size and computation time of a standard SVM by 88% and a factor of 36, with only minor degradation in gait phase prediction accuracy of around 4%. For each gait phase prediction from the RSVM, the FSM is designed to validate the prediction and correct misclassifications. The developed algorithm is implemented on a microcontroller of a wearable device and its real-time (on the fly) classification performance is evaluated by twenty healthy subjects walking along a predefined real-world route with uncontrolled free-living gait. It shows a promising real-time performance with an accuracy of 91.51%, a sensitivity of 91.70%, and a specificity of 95.77%. The algorithm also demonstrates its robustness with varying walking conditions

An Intelligent In-Shoe System for Gait Monitoring and Analysis with Optimized Sampling and Real-Time Visualization Capabilities

The deterioration of gait can be used as a biomarker for ageing and neurological diseases. Continuous gait monitoring and analysis are essential for early deficit detection and personalized rehabilitation. The use of mobile and wearable inertial sensor systems for gait monitoring and analysis have been well explored with promising results in the literature. However, most of these studies focus on technologies for the assessment of gait characteristics, few of them have considered the data acquisition bandwidth of the sensing system. Inadequate sampling frequency will sacrifice signal fidelity, thus leading to an inaccurate estimation especially for spatial gait parameters. In this work, we developed an inertial sensor based in-shoe gait analysis system for real-time gait monitoring and investigated the optimal sampling frequency to capture all the information on walking patterns. An exploratory validation study was performed using an optical motion capture system on four healthy adult subjects, where each person underwent five walking sessions, giving a total of 20 sessions. Percentage mean absolute errors (MAE) obtained in stride time, stride length, stride velocity, and cadence while walking were 1.19, 1.68, 2.08, and 1.23, respectively. In addition, an eigenanalysis based graphical descriptor from raw gait cycle signals was proposed as a new gait metric that can be quantified by principal component analysis to differentiate gait patterns, which has great potential to be used as a powerful analytical tool for gait disorder diagnostics

The causal association between smoking initiation, alcohol and coffee consumption, and women’s reproductive health: A two-sample Mendelian randomization analysis

Objective: A number of epidemiological studies have demonstrated that smoking initiation and alcohol and coffee consumption were closely related to women’s reproductive health. However, there was still insufficient evidence supporting their direct causality effect.Methods: We utilized two-sample Mendelian randomization (TSMR) analysis with summary datasets from genome-wide association study (GWAS) to investigate the causal relationship between smoking initiation, alcohol and coffee consumption, and women’s reproductive health-related traits. Exposure genetic instruments were used as variants significantly related to traits. The inverse-variance weighted (IVW) method was used as the main analysis approach, and we also performed MR-PRESSO, MR-Egger, weighted median, and weighted mode to supplement the sensitivity test. Then, the horizontal pleiotropy was detected by using MRE intercept and MR-PRESSO methods, and the heterogeneity was assessed using Cochran’s Q statistics.Results: We found evidence that smoking women showed a significant inverse causal association with the sex hormone-binding globulin (SHBG) levels (corrected β = −0.033, p = 9.05E-06) and age at menopause (corrected β = −0.477, p = 6.60E-09) and a potential positive correlation with the total testosterone (TT) levels (corrected β = 0.033, p = 1.01E-02). In addition, there was suggestive evidence for the alcohol drinking effect on the elevated TT levels (corrected β = 0.117, p = 5.93E-03) and earlier age at menopause (corrected β = −0.502, p = 4.14E-02) among women, while coffee consumption might decrease the female SHBG levels (corrected β = −0.034, p = 1.33E-03).Conclusion: Our findings suggested that smoking in women significantly decreased their SHBG concentration, promoted earlier menopause, and possibly reduced the TT levels. Alcohol drinking had a potential effect on female higher TT levels and earlier menopause, while coffee consumption might lead to lower female SHBG levels

Peroxymonosulfate activation for efficient sulfamethoxazole degradation by Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e/Β-FeOOH nanocomposites:Coexistence of radical and non-radical reactions

\u3cp\u3eEnvironmental friendly magnetic Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e/β-FeOOH nanocomposites with low cost were prepared via a simple one pot method and their physiochemical properties were investigated. The Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e/β-FeOOH nanocomposites efficiently catalyzed the activation of peroxymonosulfate (PMS) for sulfamethoxazole (SMX) degradation and can be easily recovered through magnetic separation. The effects of catalyst dosage, PMS dosage, temperature and pH were evaluated. The catalyst showed great stability and reusability based on the successive degradation cycles. The reactive oxygen species (ROS) including sulfate radical (SO\u3csub\u3e4\u3c/sub\u3e \u3csup\u3e−[rad]\u3c/sup\u3e), hydroxyl radical ([rad]OH) and singlet oxygen (\u3csup\u3e1\u3c/sup\u3eO\u3csub\u3e2\u3c/sub\u3e) were generated in the Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e/β-FeOOH/PMS system, while both of SO\u3csub\u3e4\u3c/sub\u3e \u3csup\u3e−[rad]\u3c/sup\u3e and \u3csup\u3e1\u3c/sup\u3eO\u3csub\u3e2\u3c/sub\u3e were dominantly attributed to the SMX degradation. The special tunnel-type structure and surface oxygen vacancies of β-FeOOH may be responsible for the high catalytic activity towards PMS to degrade SMX. At last, the catalytic mechanism of PMS on the surface of catalysts were proposed.\u3c/p\u3

Peroxymonosulfate activation for efficient sulfamethoxazole degradation by Fe3O4/Β-FeOOH nanocomposites: Coexistence of radical and non-radical reactions

Environmental friendly magnetic Fe3O4/β-FeOOH nanocomposites with low cost were prepared via a simple one pot method and their physiochemical properties were investigated. The Fe3O4/β-FeOOH nanocomposites efficiently catalyzed the activation of peroxymonosulfate (PMS) for sulfamethoxazole (SMX) degradation and can be easily recovered through magnetic separation. The effects of catalyst dosage, PMS dosage, temperature and pH were evaluated. The catalyst showed great stability and reusability based on the successive degradation cycles. The reactive oxygen species (ROS) including sulfate radical (SO4 −[rad]), hydroxyl radical ([rad]OH) and singlet oxygen (1O2) were generated in the Fe3O4/β-FeOOH/PMS system, while both of SO4 −[rad] and 1O2 were dominantly attributed to the SMX degradation. The special tunnel-type structure and surface oxygen vacancies of β-FeOOH may be responsible for the high catalytic activity towards PMS to degrade SMX. At last, the catalytic mechanism of PMS on the surface of catalysts were proposed

Electrospun Fibrous Membrane with Confined Chain Configuration: Dynamic Relaxation and Glass Transition

Thermodynamic glass transition processes of electrospun membranes were first introduced to study their dynamic relaxation nature, which is not constantly in equilibrium. The relaxation modes of electrospun membranes are slow but measurable near and above the Tg, given the stretched chain over long distances. Based on differential scanning calorimetry (DSC) experiments and the general principle of mode-coupling theory (MCT), endothermic peak temperature and relaxation enthalpy were used to analyze the relaxation process by capturing these instantaneous “arrested” structures. The short- and long-wavelength relaxation modes could be identified with different annealing times and temperatures relative to DSC-measured Tg for electrospun membranes with different molecular weights. Results clearly showed the dynamic nature of a glass transition in polymeric materials. Tp and enthalpy loss initially increased and then directly decreased with the increase in annealing time. When Ta > Tg, regardless of the size of the molecular weight, the Tp and enthalpy loss of the PLGA fibers would directly decrease, and the curves would shift toward the melted one. Combination of electrospinningand normal DSC instrument can be used to investigating the dynamic relax process through an adequately designed kinetic scanning procedure. This result can be explained by the general principle of MCT-type dynamic theory

Effects of Morphology and Solvent/Temperature on THz Spectra: Take Nucleosides as Example

Water molecules were easy to combine with organic molecules and embed into the lattice of solid molecules to form a hydrate. Compared with anhydrous compounds, a hydrate has completely different physical and chemical properties. In this paper, terahertz (THz) spectra of five nucleosides in the solid and liquid phases were studied experimentally by Fourier-transform infrared spectroscopy (FTIR) in the frequency of 0.5–9 THz. In addition, the lattice energy, geometric structure, and vibration spectrum of the molecular crystal of the nucleosides were analyzed theoretically by the generalized energy-based fragmentation approach under periodic boundary conditions (denoted as PBC-GEBF). Furthermore, different nucleoside molecular morphology (monomer, polymer, and crystal), solvent (implicit and explicit water), and temperature/theoretical model effect on the THz spectra were mainly investigated. It was found that in the low-frequency band, the vibrational modes were generally originated from the collective vibration of all molecules involved (more than 99% of them were vibration; only less than 1% of them were rotation and translation), which can reflect the molecular structure and spatial distribution of different substances. The Gibbs free energy of thymidine monomer, dimer, tetramer, and crystal was studied. It was found that the cell-stacking energy had the greatest influence on the spectrum, indicating that only the crystal structure constrained by the periodic boundary conditions could well describe the experimental results. In addition, hydrophobic forces dominated the formation of new chemical bonds and strong inter-molecular interactions; the free water had little contribution to the THz spectrum of nucleosides, while crystalline water had a great influence on the spectrum

Effects of Morphology and Solvent/Temperature on THz Spectra: Take Nucleosides as Example

Water molecules were easy to combine with organic molecules and embed into the lattice of solid molecules to form a hydrate. Compared with anhydrous compounds, a hydrate has completely different physical and chemical properties. In this paper, terahertz (THz) spectra of five nucleosides in the solid and liquid phases were studied experimentally by Fourier-transform infrared spectroscopy (FTIR) in the frequency of 0.5–9 THz. In addition, the lattice energy, geometric structure, and vibration spectrum of the molecular crystal of the nucleosides were analyzed theoretically by the generalized energy-based fragmentation approach under periodic boundary conditions (denoted as PBC-GEBF). Furthermore, different nucleoside molecular morphology (monomer, polymer, and crystal), solvent (implicit and explicit water), and temperature/theoretical model effect on the THz spectra were mainly investigated. It was found that in the low-frequency band, the vibrational modes were generally originated from the collective vibration of all molecules involved (more than 99% of them were vibration; only less than 1% of them were rotation and translation), which can reflect the molecular structure and spatial distribution of different substances. The Gibbs free energy of thymidine monomer, dimer, tetramer, and crystal was studied. It was found that the cell-stacking energy had the greatest influence on the spectrum, indicating that only the crystal structure constrained by the periodic boundary conditions could well describe the experimental results. In addition, hydrophobic forces dominated the formation of new chemical bonds and strong inter-molecular interactions; the free water had little contribution to the THz spectrum of nucleosides, while crystalline water had a great influence on the spectrum

Oxygen Reduction Response of La and Ce Co-Doped SrCoO_3−δ Perovskite Oxide Grown on Porous Ni-Foam Substrate

Lately, ceramic fuel cells (CFCs) have held exceptional promise for joint small- and large-scale applications. However, the low-oxygen reduction response of cathode materials has hindered the low operating temperature of CFCs. Herein, we have developed a semiconductor based on La and Ce co-doped SrCoO3 and embedded them in porous Ni-foam to study their electrochemical properties. The porous Ni-foam-pasted La0.2Sr0.8Co0.8Ce0.2O3‒δ cathode displays small-area-specific resistance and excellent ORR (oxygen reduction reaction) activity at low operating temperatures (LT) of 450–500 °C. The proposed device has delivered an impressive fuel cell performance of 440 mW-cm−2, using La0.2Sr0.8Co0.8Ce0.2O3−δ embedded on porous Ni-foam substrate cathode operation at 550 °C with H2 fuel and atmospheric air. It even can function well at a lower temperature of 450 °C. Moreover, La0.2Sr0.8Co0.8Ce0.2O3−δ embedded on porous Ni-foam shows very good activation energy compared to individual SrCoO3 and La0.1Sr0.9Co0.9Ce0.1O3−δ embedded on porous Ni-foam, which help to promote ORR activity. Different characterization has been deployed, likewise: X-ray diffraction, photoelectron-spectroscopy, and electrochemical impedance spectroscopy for a better understanding of improved ORR electrocatalytic activity of prepared La0.2Sr0.8Co0.8Ce0.2O3−δ embedded on porous Ni-foam substrate. These results can further help to develop functional cobalt-free electrocatalysts for LT-SOFCs