Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, ...activity recognition, gait analysis and so on. This paper studies a piezoelectric energy harvester for the parasitic mechanical energy in shoes originated from human motion. The harvester is based on a specially designed sandwich structure with a thin thickness, which makes it readily compatible with a shoe. Besides, consideration is given to both high performance and excellent durability. The harvester provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz. Furthermore, a direct current (DC) power supply is built through integrating the harvester with a power management circuit. The DC power supply is tested by driving a simulated wireless transmitter, which can be activated once every 2-3 steps with an active period lasting 5 ms and a mean power of 50 mW. This work demonstrates the feasibility of applying piezoelectric energy harvesters to power wearable sensors.
Bioelectrical or electrophysiological signals generated by living cells or tissues during daily physiological activities are closely related to the state of the body and organ functions, and ...therefore are widely used in clinical diagnosis, health monitoring, intelligent control and human-computer interaction. Ag/AgCl electrodes with wet conductive gels are widely used to pick up these bioelectrical signals using electrodes and record them in the form of electroencephalograms, electrocardiograms, electromyography, electrooculograms, etc. However, the inconvenience, instability and infection problems resulting from the use of gel with Ag/AgCl wet electrodes can't meet the needs of long-term signal acquisition, especially in wearable applications. Hence, focus has shifted toward the study of dry electrodes that can work without gels or adhesives. In this paper, a retrospective overview of the development of dry electrodes used for monitoring bioelectrical signals is provided, including the sensing principles, material selection, device preparation, and measurement performance. In addition, the challenges regarding the limitations of materials, fabrication technologies and wearable performance of dry electrodes are discussed. Finally, the development obstacles and application advantages of different dry electrodes are analyzed to make a comparison and reveal research directions for future studies.
Environment-friendly, function tunable, and low-cost adsorbents/amendments from agricultural residue-derived biochar show enormous potential for mitigating the environment problems. A series of ...nano-sized goethite modified biochar (GMB) material were synthesized by co-precipitating with crop residue-derived biochar and could be used for amelioration of cation, anion, antibiotics, and non-point source pollutant in both soil and water. The GMB materials were characterized by SEM-EDS, BET, FTIR, XRD, VSM, and XPS analysis. Their adsorption performance for cationic Cd(II), anionic As(III), antibiotics roxarsone (ROX), and non-point source pollutant phosphorus in water was evaluated by adsorption kinetics and equilibrium experiments. Based on Langmuir model, the maximum adsorption capacities of Cd(II), As(III), ROX, and phosphorus were 31.9, 65.3, 66.5, and 42.7 mg/g, respectively, which were enhanced by 135%, 6279%, 961%, and 2437% compared to pristine biochar. The adsorption behavior of GMB can be explained by non-specific adsorption (electrostatic interaction and physical adsorption), specific adsorption (hydroxyl complex, π-π interaction, surface complexation, ion exchange, etc.), and chemisorption induced by goethite nanoparticles on the GMB. Moreover, GMB (1 wt%) also performed well for immobilization of these four contaminants in soil. After GMB treatment, the concentrations of available Cd, As, ROX, and phosphorus in soil decreased by 74.1%, 58.7%, 70.8%, and 29.1%, respectively. This study proposed that the scalable GMB can be considered as a sustainable multifunctional material for soil and water decontamination.
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•Nano-sized goethite modified biochar (GMB) was generated by co-precipitation.•GMB showed good adsorption performance for Cd(II), As(III), ROX, and phosphate.•FTIR and XPS confirmed the complexation and ion exchange for tested contaminants.•GMB effectively immobilized Cd(II), As(III), ROX, and phosphorus in contaminated soil.
Interactive animation design, as a branch of the animation field, has received much attention in recent years. From web pages to personal operating systems, more and more interactive designs are ...emerging in people's lives. As an important part of the interactive animation design field, rich color design will surely enter the designer's vision in the field of interactive animation design. In this paper, the multi-culture of information age integrates the basic concepts and characteristics of interactive animation, and illustrates the visual turn of interactive animation aesthetic objects with specific cases. Combined with the technical and cultural characteristics of interactive animation, this paper expounds interactive animation. Virtual interaction. Animate the aesthetic experience and bring it to the participants. A more realistic immersive experience that analyzes the use of color design in interactive animation design.
Abstract A crucial step in life processes is the transfer of accurate and correct genetic material to offspring. During the construction of autonomous artificial cells, a very important step is the ...inheritance of genetic information in divided artificial cells. The ParMRC system, as one of the most representative systems for DNA segregation in bacteria, can be purified and reconstituted into GUVs to form artificial cells. In this study, we demonstrate that the eGFP gene is segregated into two poles by a ParM filament with ParR as the intermediate linker to bind ParM and parC -eGFP DNA in artificial cells. After the ParM filament splits, the cells are externally induced to divide into two daughter cells that contain parC -eGFP DNA by osmotic pressure and laser irradiation. Using a PURE system, we translate eGFP DNA into enhanced green fluorescent proteins in daughter cells, and bacterial plasmid segregation and inheritance are successfully mimicked in artificial cells. Our results could lead to the construction of more sophisticated artificial cells that can reproduce with genetic information.
This paper proposes a variable coefficient combined virtual inertia and primary frequency control strategy for doubly fed induction generators (DFIG) in coordination with diesel generator to ...participate in wind/photovoltaic/diesel microgrid frequency regulation. The frequency response characteristic is analyzed under different wind speeds with corresponding inertia control parameters different. A 10% wind power margin is preserved through overspeed control and pitch angle control to offset the decrease of wind output power after temporary extra power surge, and provide a permanent frequency support for microgrids. The influence of droop control gain setting is also illustrated under different wind velocities. By continuously adjusting the control parameters according to wind speed variation, a variable coefficient method is realized. The method can guarantee an efficient implementation of this strategy in time-varying conditions. Finally, this coordinated control strategy is tested in a storage-independent microgrid with solar, wind, and diesel generators.
Osteoporosis is a systemic metabolic bone disease characterized by a reduction in bone mass, bone quality, and microarchitectural deterioration. An imbalance in bone remodeling that is caused by more ...osteoclast-mediated bone resorption than osteoblast-mediated bone formation results in such pathologic bone disorder. Traditional Chinese medicines (TCM) have long been used to prevent and treat osteoporosis and have received extensive attentions and researches at home and abroad, because they have fewer adverse reactions and are more suitable for long-term use compared with chemically synthesized medicines. Here, we put the emphasis on osteoblasts, summarized the detailed research progress on the active compounds derived from TCM with potential anti-osteoporosis effects and their molecular mechanisms on promoting osteoblast-mediated bone formation. It could be concluded that TCM with kidney-tonifying, spleen-tonifying, and stasis-removing effects all have the potential effects on treating osteoporosis. The active ingredients derived from TCM that possess effects on promoting osteoblasts proliferation and differentiation include flavonoids, glycosides, coumarins, terpenoids (sesquiterpenoids, monoterpenoids, diterpenoids), phenolic acids, phenols and others (tetrameric stilbene, anthraquinones, diarylheptanoids). And it was confirmed that the bone formation effect induced by the above natural products was regulated by the expressions of bone specific matrix proteins (ALP, BSP, OCN, OPN, COL I), transcription factor (Runx2, Cbfa1, Osx), signal pathways (MAPK, BMP), local factors (ROS, NO), OPG/RANKL system of osteoblasts and estrogen-like biological activities. All the studies provided theoretical basis for clinical application, as well as new drug research and development on treating osteoporosis.
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Flexible supercapacitors with high power density, flexibility, and durability have shown enormous potential for smart electronics. Here, a continuous graphitic carbon nitride polyhedron assembly for ...flexible supercapacitor that is prepared by pyrolysis of carbon nanotubes wired zeolitic imidazolate framework‐8 (ZIF‐8) composites under nitrogen is reported. It exhibits a high specific capacitance of 426 F g−1 at current density of 1 A g−1 in 1 m H2SO4 and excellent stability over 10 000 cycles. The remarkable performance results from the continuous hierarchical structure with average pore size of 2.5 nm, high nitrogen‐doping level (17.82%), and large specific surface area (920 m2 g−1). Furthermore, a flexible supercapacitor is developed by constructing the assembly with interpenetrating polymer network electrolyte. Stemming from the synergistic effect of high‐performance electrode and highly ion‐conductive electrolyte, superior energy density of 59.40 Wh kg−1 at 1 A g−1 is achieved. The device maintains a stable energy supply under cyclic deformations, showing wide application in flexible and even wearable conditions. The work paves a new way for designing pliable electrode with excellent electronic and mechanic property for long‐lived flexible energy storage devices.
A continuous carbon nitride polyhedron assembly is developed using a facile pyrolysis method and is further constructed into a flexible supercapacitor with a highly ion‐conductive interpenetrating polymer network electrolyte. The high energy capacity of the device along with excellent flexibility demonstrates advancement of the novel assembly strategy, providing new insight into rational design of electrode materials for long‐lived flexible energy storage devices.
An epidemic of Coronavirus Disease 2019 (COVID-19) began in December 2019 and triggered a Public Health Emergency of International Concern (PHEIC). We aimed to find risk factors for the progression ...of COVID-19 to help reducing the risk of critical illness and death for clinical help.
The data of COVID-19 patients until March 20, 2020 were retrieved from four databases. We statistically analyzed the risk factors of critical/mortal and non-critical COVID-19 patients with meta-analysis.
Thirteen studies were included in Meta-analysis, including a total number of 3027 patients with SARS-CoV-2 infection. Male, older than 65, and smoking were risk factors for disease progression in patients with COVID-19 (male: OR = 1.76, 95% CI (1.41, 2.18), P < 0.00001; age over 65 years old: OR =6.06, 95% CI(3.98, 9.22), P < 0.00001; current smoking: OR =2.51, 95% CI(1.39, 3.32), P = 0.0006). The proportion of underlying diseases such as hypertension, diabetes, cardiovascular disease, and respiratory disease were statistically significant higher in critical/mortal patients compared to the non-critical patients (diabetes: OR=3.68, 95% CI (2.68, 5.03), P < 0.00001; hypertension: OR = 2.72, 95% CI (1.60,4.64), P = 0.0002; cardiovascular disease: OR = 5.19, 95% CI(3.25, 8.29), P < 0.00001; respiratory disease: OR = 5.15, 95% CI(2.51, 10.57), P < 0.00001). Clinical manifestations such as fever, shortness of breath or dyspnea were associated with the progression of disease fever: 0R = 0.56, 95% CI (0.38, 0.82), P = 0.003;shortness of breath or dyspnea: 0R=4.16, 95% CI (3.13, 5.53), P < 0.00001. Laboratory examination such as aspartate amino transferase(AST) > 40U/L, creatinine(Cr) ≥ 133mol/L, hypersensitive cardiac troponin I(hs-cTnI) > 28pg/mL, procalcitonin(PCT) > 0.5ng/mL, lactatede hydrogenase(LDH) > 245U/L, and D-dimer > 0.5mg/L predicted the deterioration of disease while white blood cells(WBC)<4 × 109/L meant a better clinical statusAST > 40U/L:OR=4.00, 95% CI (2.46, 6.52), P < 0.00001; Cr ≥ 133μmol/L: OR = 5.30, 95% CI (2.19, 12.83), P = 0.0002; hs-cTnI > 28 pg/mL: OR = 43.24, 95% CI (9.92, 188.49), P < 0.00001; PCT > 0.5 ng/mL: OR = 43.24, 95% CI (9.92, 188.49), P < 0.00001;LDH > 245U/L: OR = 43.24, 95% CI (9.92, 188.49), P < 0.00001; D-dimer > 0.5mg/L: OR = 43.24, 95% CI (9.92, 188.49), P < 0.00001; WBC < 4 × 109/L: OR = 0.30, 95% CI (0.17, 0.51), P < 0.00001.
Male, aged over 65, smoking patients might face a greater risk of developing into the critical or mortal condition and the comorbidities such as hypertension, diabetes, cardiovascular disease, and respiratory diseases could also greatly affect the prognosis of the COVID-19. Clinical manifestation such as fever, shortness of breath or dyspnea and laboratory examination such as WBC, AST, Cr, PCT, LDH, hs-cTnI and D-dimer could imply the progression of COVID-19.
Two-dimensional (2D) perovskites have been shown to be more stable than their three-dimensional (3D) counterparts due to the protection of the organic ligands. Herein a method is introduced to form ...2D/3D stacking structures by the reaction of 3D perovskite with n-Butylamine (BA). Different from regular treatment with n-Butylammonium iodide (BAI) where 2D perovskite with various layers form, the reaction of BA with MAPbI3 only produce (BA)2PbI4, which has better protection due to more organic ligands in (BA)2PbI4 than the mixture of 2D perovskites. Compared to BAI treatment, BA treatment results in smoother 2D perovskite layer on 3D perovskites with a better coverage. The photovoltaic devices with 2D/3D stacking structures show much improved stability in comparison to their 3D counterparts when subjected to heat stress tests. Moreover, the conversion of defective surface into 2D layers also induces passivation of the 3D perovskites resulting in an enhanced efficiency.
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