A long debate on the charge identity and the associated mechanisms occurring in contact‐electrification (CE) (or triboelectrification) has persisted for many decades, while a conclusive model has not ...yet been reached for explaining this phenomenon known for more than 2600 years! Here, a new method is reported to quantitatively investigate real‐time charge transfer in CE via triboelectric nanogenerator as a function of temperature, which reveals that electron transfer is the dominant process for CE between two inorganic solids. A study on the surface charge density evolution with time at various high temperatures is consistent with the electron thermionic emission theory for triboelectric pairs composed of Ti–SiO2 and Ti–Al2O3. Moreover, it is found that a potential barrier exists at the surface that prevents the charges generated by CE from flowing back to the solid where they are escaping from the surface after the contacting. This pinpoints the main reason why the charges generated in CE are readily retained by the material as electrostatic charges for hours at room temperature. Furthermore, an electron‐cloud–potential‐well model is proposed based on the electron‐emission‐dominatedcharge‐transfer mechanism, which can be generally applied to explain all types of CE in conventional materials.
Real‐time charge transfer in contact electrification (CE) is investigated quantitatively as a function of temperature via a triboelectric nanogenerator, revealing that electron transfer is the dominant process for CE between two inorganic solids. An electron‐cloud–potential‐well model is proposed for understanding all types of CE in conventional materials.
Cellulose‐based triboelectric nanogenerators (TENGs) have gained increasing attention. In this study, a novel method is demonstrated to synthesize cellulose‐based aerogels and such aerogels are used ...to fabricate TENGs that can serve as mechanical energy harvesters and self‐powered sensors. The cellulose II aerogel is fabricated via a dissolution–regeneration process in a green inorganic molten salt hydrate solvent (lithium bromide trihydrate), where. The as‐fabricated cellulose II aerogel exhibits an interconnected open‐pore 3D network structure, higher degree of flexibility, high porosity, and a high surface area of 221.3 m2 g−1. Given its architectural merits, the cellulose II aerogel‐based TENG presents an excellent mechanical response sensitivity and high electrical output performance. By blending with other natural polysaccharides, i.e., chitosan and alginic acid, electron‐donating and electron‐withdrawing groups are introduced into the composite cellulose II aerogels, which significantly improves the triboelectric performance of the TENG. The cellulose II aerogel‐based TENG is demonstrated to light up light‐emitting diodes, charge commercial capacitors, power a calculator, and monitor human motions. This study demonstrates the facile fabrication of cellulose II aerogel and its application in TENG, which leads to a high‐performance and eco‐friendly energy harvesting and self‐powered system.
Cellulose II aerogels, with the features of high flexibility, porosity, and surface area, are integrated with triboelectric nanogenerators to yield green, sustainable energy harvesting, and sensing devices. By blending other natural polysaccharides to introduce electron‐donating and electron‐withdrawing groups, the performance of the cellulose II aerogel‐based triboelectric nanogenerators can be significantly improved and used for mechanical energy harvesting and motion monitoring.
Co-infection has been reported in patients with severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome, but there is limited knowledge on co-infection among patients with ...coronavirus disease 2019 (COVID-19). The prevalence of co-infection was variable among COVID-19 patients in different studies, however, it could be up to 50% among non-survivors. Co-pathogens included bacteria, such as Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumonia, Legionella pneumophila and Acinetobacter baumannii; Candida species and Aspergillus flavus; and viruses such as influenza, coronavirus, rhinovirus/enterovirus, parainfluenza, metapneumovirus, influenza B virus, and human immunodeficiency virus. Influenza A was one of the most common co-infective viruses, which may have caused initial false-negative results of real-time reverse-transcriptase polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Laboratory and imaging findings alone cannot help distinguish co-infection from SARS-CoV-2 infection. Newly developed syndromic multiplex panels that incorporate SARS-CoV-2 may facilitate the early detection of co-infection among COVID-19 patients. By contrast, clinicians cannot rule out SARS-CoV-2 infection by ruling in other respiratory pathogens through old syndromic multiplex panels at this stage of the COVID-19 pandemic. Therefore, clinicians must have a high index of suspicion for coinfection among COVID-19 patients. Clinicians can neither rule out other co-infections caused by respiratory pathogens by diagnosing SARS-CoV-2 infection nor rule out COVID-19 by detection of non-SARS-CoV-2 respiratory pathogens. After recognizing the possible pathogens causing co-infection among COVID-19 patients, appropriate antimicrobial agents can be recommended.
Growing demand in portable electronics raises a requirement to electronic devices being stretchable, deformable, and durable, for which functional polymers are ideal choices of materials. Here, the ...first transformable smart energy harvester and self‐powered mechanosensation sensor using shape memory polymers is demonstrated. The device is based on the mechanism of a flexible triboelectric nanogenerator using the thermally triggered shape transformation of organic materials for effectively harvesting mechanical energy. This work paves a new direction for functional polymers, especially in the field of mechanosensation for potential applications in areas such as soft robotics, biomedical devices, and wearable electronics.
A shape‐memory‐polymer‐based triboelectric nanogenerator (STENG) is developed to harvest biomechanical energy and detect biomechanical motion. The STENG is able to transform its shape according to different requirements and hold on to a temporary configuration, which can act as an energy harvester as well as a self‐powered, wearable, biomechanical sensor.
To assess the clinical efficacy and safety of neutralizing monoclonal antibodies (mABs) for outpatients with coronavirus disease 2019 (COVID‐19). PubMed, Embase, Web of Science, Cochrane Library, ...ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform (ICTRP) databases were searched from inception to July 19, 2021. Only randomized controlled trials (RCTs) that assessed the clinical efficacy and safety of neutralizing mABs in the treatment of COVID‐19 outpatients were included. The Cochrane risk‐of‐bias tool was used to assess the quality of the included RCTs. The primary outcome was the risk of COVID‐19‐related hospitalization or emergency department (ED) visits. The secondary outcomes were the risk of death and adverse events (AEs). Five articles were included, in which 3309 patients received neutralizing mAB and 2397 patients received a placebo. A significantly lower rate of hospitalization or ED visits was observed among patients who received neutralizing mABs than those who received a placebo (1.7% vs. 6.5%, odds ratios (OR): 0.26; 95% confidence interval (CI): 0.19–0.36; I2 = 0%). In addition, the rate of hospitalization was significantly lower in the patients who received neutralizing mABs than in the control group (OR: 0.24; 95% CI: 0.17−0.34; I2 = 0%). The mortality rate was also significantly lower in the patients who received neutralizing mABs than in the control group (OR: 0.16; 95% CI: 0.05−0.58; I2 = 3%). Neutralizing mABs were associated with a similar risk of any AE (OR: 0.81; 95% CI: 0.64–1.01; I2 = 52%) and a lower risk of serious AEs (OR: 0.37; 97% CI: 0.19–0.72; I2 = 45%) compared with a placebo. Neutralizing mABs can help reduce the risk of hospitalization or ED visits in COVID‐19 outpatients. For these patients, neutralizing mABs are safe and not associated with a higher risk of AEs than a placebo.
Highlights
Neutralizing monoclonal antibodies (mABs) decreased risk of hospitalization or emergence department visits in coronavirus disease 2019 (COVID‐19) outpatients.
Neutralizing mABs reduced mortality in COVID‐19 outpatients.
Neutralizing mABs had no increased risk of any adverse events (AEs) and lower risk of serious AEs.
There has long been a need for more advanced forms of pathogen detection in the food industry. Though in its infancy, biosensing based on clustered regularly interspaced short palindromic repeats ...(CRISPR) has the potential to solve many problems that cannot be addressed using conventional methods. In this review, we briefly introduce and classify the various CRISPR/Cas protein effectors that have thus far been used in biosensors. We then assess the current state of CRISPR technology in food‐safety contexts; describe how each Cas effector is utilized in foodborne‐pathogen detection; and discuss the limitations of the current technology, as well as how it might usefully be applied in other areas of the food industry. We conclude that, if the limitations of existing CRISPR/Cas‐based detection methods are overcome, they can be deployed on a wide scale and produce a range of positive food‐safety outcomes.
The development of wearable and large‐area energy‐harvesting textiles has received intensive attention due to their promising applications in next‐generation wearable functional electronics. However, ...the limited power outputs of conventional textiles have largely hindered their development. Here, in combination with the stainless steel/polyester fiber blended yarn, the polydimethylsiloxane‐coated energy‐harvesting yarn, and nonconductive binding yarn, a high‐power‐output textile triboelectric nanogenerator (TENG) with 3D orthogonal woven structure is developed for effective biomechanical energy harvesting and active motion signal tracking. Based on the advanced 3D structural design, the maximum peak power density of 3D textile can reach 263.36 mW m−2 under the tapping frequency of 3 Hz, which is several times more than that of conventional 2D textile TENGs. Besides, its collected power is capable of lighting up a warning indicator, sustainably charging a commercial capacitor, and powering a smart watch. The 3D textile TENG can also be used as a self‐powered active motion sensor to constantly monitor the movement signals of human body. Furthermore, a smart dancing blanket is designed to simultaneously convert biomechanical energy and perceive body movement. This work provides a new direction for multifunctional self‐powered textiles with potential applications in wearable electronics, home security, and personalized healthcare.
In combination with stainless‐steel/polyester fiber blended warp yarn, poly(dimethylsiloxane)‐coated energyharvesting weft yarn, and nonconductive Z‐directional binding yarn, a high‐power‐output textile triboelectric nanogenerator with 3D orthogonal woven structure is developed for effective biomechanical energy harvesting and active motion signals tracking. The multifunctional self‐powered 3D textiles have potential applications in wearable electronics, home security, and personalized healthcare.
Since the emergence of coronavirus disease 2019 (COVID-19) (formerly known as the 2019 novel coronavirus 2019-nCoV) in Wuhan, China in December 2019, which is caused by severe acute respiratory ...syndrome coronavirus 2 (SARS-CoV-2), more than 75,000 cases have been reported in 32 countries/regions, resulting in more than 2000 deaths worldwide. Despite the fact that most COVID-19 cases and mortalities were reported in China, the WHO has declared this outbreak as the sixth public health emergency of international concern. The COVID-19 can present as an asymptomatic carrier state, acute respiratory disease, and pneumonia. Adults represent the population with the highest infection rate; however, neonates, children, and elderly patients can also be infected by SARS-CoV-2. In addition, nosocomial infection of hospitalized patients and healthcare workers, and viral transmission from asymptomatic carriers are possible. The most common finding on chest imaging among patients with pneumonia was ground-glass opacity with bilateral involvement. Severe cases are more likely to be older patients with underlying comorbidities compared to mild cases. Indeed, age and disease severity may be correlated with the outcomes of COVID-19. To date, effective treatment is lacking; however, clinical trials investigating the efficacy of several agents, including remdesivir and chloroquine, are underway in China. Currently, effective infection control intervention is the only way to prevent the spread of SARS-CoV-2.
Harvesting ambient mechanical energy is a key technology for realizing self-powered electronics. With advantages of stability and durability, a liquid–solid-based triboelectric nanogenerator (TENG) ...has recently drawn much attention. However, the impacts of liquid properties on the TENG performance and the related working principle are still unclear. We assembled herein a U-tube TENG based on the liquid–solid mode and applied 11 liquids to study the effects of liquid properties on the TENG output performance. The results confirmed that the key factors influencing the output are polarity, dielectric constant, and affinity to fluorinated ethylene propylene (FEP). Among the 11 liquids, the pure water-based U-tube TENG exhibited the best output with an open-circuit voltage (
V
oc
) of 81.7 V and a short-circuit current (
I
sc
) of 0.26 μA for the shaking mode (0.5 Hz), which can further increase to 93.0 V and 0.48 μA, respectively, for the horizontal shifting mode (1.25 Hz). The U-tube TENG can be utilized as a self-powered concentration sensor (component concentration or metalion concentration) for an aqueous solution with an accuracy higher than 92%. Finally, an upgraded sandwich-like water-FEP U-tube TENG was applied to harvest water-wave energy, showing a high output with
V
oc
of 350 V,
I
sc
of 1.75 μA, and power density of 2.04 W/m
3
. We successfully lighted up 60 LEDs and powered a temperature–humidity meter. Given its high output performance, the water-FEP U-tube TENG is a very promising approach for harvesting water-wave energy for self-powered electronics.
Materials with tunable long persistent luminescence (LPL) properties have wide applications in security signs, anti‐counterfeiting, data encrypting, and other fields. However, the majority of ...reported tunable LPL materials are pure organic molecules or polymers. Herein, a series of metal‐organic coordination polymers displaying color‐tunable LPL were synthesized by the self‐assembly of HTzPTpy ligand with different cadmium halides (X=Cl, Br, and I). In the solid state, their LPL emission colors can be tuned by the time‐evolution, as well as excitation and temperature variation, realizing multi‐mode dynamic color tuning from green to yellow or green to red, and are the first such examples in single‐component coordination polymer materials. Single‐crystal X‐ray diffraction analysis and theoretical calculations reveal that the modification of LPL is due to the balanced action from single molecule and aggregate triplet excited states caused by an external heavy‐atom effect. The results show that the rational introduction of different halide anions into coordination polymers can realize multi‐color LPL.
By delicate design of coordination polymers incorporating different halogens, multi‐mode color‐tunable long persistent luminescence (LPL) from green to yellow or green to red was possible. The LPL emission colors can be tuned by time, excitation, and temperature, revealing the counter‐balanced mechanisms from single‐molecule and aggregate triplet excited states resulting from an external heavy‐atom effect.
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