Self-Powered Hybrid Motion and Health Sensing System Based on Triboelectric Nanogenerators.

Triboelectric nanogenerator (TENG) represents an effective approach for the conversion of mechanical energy into electrical energy and has been explored to combine multiple technologies in past years. Self-powered sensors are not only free from the constraints of mechanical energy in the environment but also capable of efficiently harvesting ambient energy to sustain continuous operation. In this review, the remarkable development of TENG-based human body sensing achieved in recent years is presented, with a specific focus on human health sensing solutions, such as body motion and physiological signal detection. The movements originating from different parts of the body, such as body, touch, sound, and eyes, are systematically classified, and a thorough review of sensor structures and materials is conducted. Physiological signal sensors are categorized into non-implantable and implantable biomedical sensors for discussion. Suggestions for future applications of TENG-based biomedical sensors are also indicated, highlighting the associated challenges.

Application of Carbon Materials in Aqueous Zinc Ion Energy Storage Devices.

Zinc-ion storage is a promising electrochemical energy field due to loads of its advantages like easy preparation, environmental friendliness, high safety performance, and high capacity. Carbon materials have been widely studied for zinc-ion storage due to their extraordinary properties such as earth-abundancy, low-cost, good electrical conductivity, various structures, and good stability. This article reviews some widely used carbon materials in zinc ion storage devices, including hollow carbon spheres, activated carbon, N-doped porous carbon, graphene, and carbon nanotubes. The unique roles and advantages of these carbon materials in both zinc ion supercapacitors and zinc ion batteries are emphasized. Characteristics and functionalizations of different carbon materials are also comparatively discussed in view of zinc-ion energy storage devices. Finally, some challenges and perspectives of carbon materials in zinc-ion energy storage are outlined.

Flexible, Stretchable, and Transparent Planar Microsupercapacitors Based on 3D Porous Laser-Induced Graphene.

The graphene with 3D porous network structure is directly laser-induced on polyimide sheets at room temperature in ambient environment by an inexpensive and one-step method, then transferred to silicon rubber substrate to obtain highly stretchable, transparent, and flexible electrode of the all-solid-state planar microsupercapacitors. The electrochemical capacitance properties of the graphene electrodes are further enhanced by nitrogen doping and with conductive poly(3,4-ethylenedioxythiophene) coating. With excellent flexibility, stretchability, and capacitance properties, the planar microsupercapacitors present a great potential in fashionable and comfortable designs for wearable electronics.

Different Microtubule Structures Assembled by Kinesin Motors.

The microtubule-kinesin system is used to form microtubule-based structures via microtubule gliding motility. On the kinesin-coated surface, the microtubules can be easily assembled into stable micro- and nanostructures like circles and microtubule bundles using the streptavidin-biotin system. Furthermore, these microtubules structures can still retain performance with kinesin motor movement in spite of different velocities. Collisions bear responsibility for the majority of events leading to circle formation. By taking advantage of biological substances, some micro- or nanostructures, which are difficult to fabricate by artificial processes, can be easily obtained.

A Layer-by-Layer Self-Assembled Bio-Macromolecule Film for Stable Zinc Anode.

Side reactions on zinc metal (Zn) anodes are formidable issues that cause limited battery life of aqueous zinc-ion batteries (AZIBs). Here, a facile and controllable layer-by-layer (LbL) self-assembly technique is deployed to construct an ion-conductive and mechanically robust electrolyte/anode interface for stabilizing the Zn anode. The LbL film consists of two natural and biodegradable bio-macromolecules, chitosan (CS) and sodium alginate (SA). It is shown that such an LbL film tailors the solvation sheath of Zn ions and facilitates the oriented deposition of Zn. Symmetric cells with the four double layers of CS/SA ((CS/SA)4 -Zn) exhibit stable cycles for over 6500 h. The (CS/SA)4 -Zn||H2 V3 O8 coin cell maintains a specific capacity of 125.5 mAh g-1 after 14 000 cycles. The pouch cell with an electrode area of 5 × 7 cm2 also presents a capacity retention of 83% for over 500 cycles at 0.1 A g-1 . No obvious dendrites are observed after long cycles in both symmetric and full cells. Given the cost-effective material and fabrication, and environmental friendliness of the LbL films, this Zn protection strategy may boost the industrial application of AZIBs.

The impact of arbuscular mycorrhizal fungi and endophytic bacteria on peanuts under the combined pollution of cadmium and microplastics.

It remains unclear how symbiotic microbes impact the growth of peanuts when they are exposed to the pollutants cadmium (Cd) and microplastics (MPs) simultaneously. This study aimed to investigate the effects of endophytic bacteria Bacillus velezens SC60 and arbuscular mycorrhizal fungus Rhizophagus irregularis on peanut growth and rhizosphere microbial communities in the presence of Cd at 40 (Cd40) or 80 (Cd80) mg kg-1 combined without MP or the presence of low-density polyethylene (LDPE) and poly butyleneadipate-co-terephthalate (PBAT). This study assessed soil indicators, plant parameters, and Cd accumulation indicators. Results showed that the application of R. irregularis and B. velezens significantly enhanced soil organic carbon and increased Cd content under the conditions of Cd80 and MPs co-pollution. R. irregularis and B. velezens treatment increased peanut absorption and the enrichment coefficient for Cd, with predominate concentrations localized in the peanut roots, especially under combined pollution by Cd and MPs. Under treatments with Cd40 and Cd80 combined with PBAT pollution, soil microbes Proteobacteria exhibited a higher relative abundance, while Actinobacteria showed a higher relative abundance under treatments with Cd40 and Cd80 combined with LDPE pollution. In conclusion, under the combined pollution conditions of MPs and Cd, the co-treatment of R. irregularis and B. velezens effectively immobilized Cd in peanut roots, impeding its translocation to the shoot.

Pathways toward wearable and high-performance sensors based on hydrogels: toughening networks and conductive networks.

Wearable hydrogel sensors provide a user-friendly option for wearable electronics and align well with the existing manufacturing strategy for connecting and communicating with large numbers of Internet of Things devices. This is attributed to their components and structures, which exhibit exceptional adaptability, scalability, bio-compatibility, and self-healing properties, reminiscent of human skin. This review focuses on the recent research on principal structural elements of wearable hydrogels: toughening networks and conductive networks, highlighting the strategies for enhancing mechanical and electrical properties. Wearable hydrogel sensors are categorized for an extensive exploration of their composition, mechanism, and design approach. This review provides a comprehensive understanding of wearable hydrogels and offers guidance for the design of components and structures in order to develop high-performance wearable hydrogel sensors.

Chromosome size in diploid eukaryotic species centers on the average length with a conserved boundary.

Understanding genome and chromosome evolution is important for understanding genetic inheritance and evolution. Universal events comprising DNA replication, transcription, repair, mobile genetic element transposition, chromosome rearrangements, mitosis, and meiosis underlie inheritance and variation of living organisms. Although the genome of a species as a whole is important, chromosomes are the basic units subjected to genetic events that coin evolution to a large extent. Now many complete genome sequences are available, we can address evolution and variation of individual chromosomes across species. For example, "How are the repeat and nonrepeat proportions of genetic codes distributed among different chromosomes in a multichromosome species?" "Is there a general rule behind the intuitive observation that chromosome lengths tend to be similar in a species, and if so, can we generalize any findings in chromosome content and size across different taxonomic groups?" Here, we show that chromosomes within a species do not show dramatic fluctuation in their content of mobile genetic elements as the proliferation of these elements increases from unicellular eukaryotes to vertebrates. Furthermore, we demonstrate that, notwithstanding the remarkable plasticity, there is an upper limit to chromosome-size variation in diploid eukaryotes with linear chromosomes. Strikingly, variation in chromosome size for 886 chromosomes in 68 eukaryotic genomes (including 22 human autosomes) can be viably captured by a single model, which predicts that the vast majority of the chromosomes in a species are expected to have a base pair length between 0.4035 and 1.8626 times the average chromosome length. This conserved boundary of chromosome-size variation, which prevails across a wide taxonomic range with few exceptions, indicates that cellular, molecular, and evolutionary mechanisms, possibly together, confine the chromosome lengths around a species-specific average chromosome length.

A Molecular-Sieve Electrolyte Membrane enables Separator-Free Zinc Batteries with Ultralong Cycle Life.

The poor stability of the zinc-metal anode is a main bottleneck for practical application of aqueous zinc-ion batteries. Herein, a series of molecular sieves with various channel sizes are investigated as an electrolyte host to regulate the ionic environment of Zn2+ on the surface of the zinc anode and to realize separator-free batteries. Based on the ZSM-5 molecular sieve, a solid-liquid mixed electrolyte membrane is constructed to uniformize the transport of zinc ions and foster dendrite-free Zn deposition. Side reactions can also be suppressed through tailoring the solvation sheath and restraining the activity of water molecules in electrolyte. A V2 O5 ||ZSM-5||Zn full cell shows significantly enhanced performance compared to cells using glass fiber separator. Specifically, it exhibits a high specific capacity of 300 mAh g-1 , and a capacity retention of 98.67% after 1000 cycles and 82.67% after 3000 cycles at 1 A g-1 . It is attested that zeolites (ZSM-5, H-ß, and Bate) with channel sizes of 5-7 Å result in best cycle stability. Given the low cost and recyclability of the ZSM and its potent function, this work may further lower the cost and boost the industrial application of AZIBs.

Pan-Genome Analysis of Delftia tsuruhatensis Reveals Important Traits Concerning the Genetic Diversity, Pathogenicity, and Biotechnological Properties of the Species.

Delftia tsuruhatensis strains have long been known to promote plant growth and biological control. Recently, it has become an emerging opportunistic pathogen in humans. However, the genomic characteristics of the genetic diversity, pathogenicity, and biotechnological properties have not yet been comprehensively investigated. Here, a comparative pan-genome analysis was constructed. The open pan-genome with a large and flexible gene repertoire exhibited a high degree of genetic diversity. The purifying selection was the main force to drive pan-genome evolution. Significant differences were observed in the evolutionary relationship, functional enrichment, and degree of selective pressure between the different components of the pan-genome. A high degree of genetic plasticity was characterized by the determinations of diverse mobile genetic elements (MGEs), massive genomic rearrangement, and horizontal genes. Horizontal gene transfer (HGT) plays an important role in the genetic diversity of this bacterium and the formation of genomic traits. Our results revealed the occurrence of diverse virulence-related elements associated with macromolecular secretion systems, virulence factors associated with multiple nosocomial infections, and antimicrobial resistance, indicating the pathogenic potential. Lateral flagellum, T1SS, T2SS, T6SS, Tad pilus, type IV pilus, and a part of virulence-related genes exhibited general properties, whereas polar flagellum, T4SS, a part of virulence-related genes, and resistance genes presented heterogeneous properties. The pan-genome also harbors abundant genetic traits related to secondary metabolism, carbohydrate active enzymes (CAZymes), and phosphate transporter, indicating rhizosphere adaptation, plant growth promotion, and great potential uses in agriculture and biological control. This study provides comprehensive insights into this uncommon species from the genomic perspective. IMPORTANCE D. tsuruhatensis is considered a plant growth-promoting rhizobacterium (PGPR), an organic pollutant degradation strain, and an emerging opportunistic pathogen to the human. However, the genetic diversity, the evolutionary dynamics, and the genetic basis of these remarkable traits are still little known. We constructed a pan-genome analysis for D. tsuruhatensis and revealed extensive genetic diversity and genetic plasticity exhibited by open pan-genome, diverse mobile genetic elements (MGEs), genomic rearrangement, and horizontal genes. Our results highlight that horizontal gene transfer (HGT) and purifying selection are important forces in D. tsuruhatensis genetic evolution. The abundant virulence-related elements associated with macromolecular secretion systems, virulence factors, and antimicrobial resistance could contribute to the pathogenicity of this bacterium. Therefore, clinical microbiologists need to be aware of D. tsuruhatensis as an opportunistic pathogen. The genetic profiles of secondary metabolism, carbohydrate active enzymes (CAZymes), and phosphate transporter could provide insight into the genetic armory of potential applications for agriculture and biological control of D. tsuruhatensis in general.

Honeycomb self-assembled peptide scaffolds by the breath figure method.

The self-assembly of molecules into desired architectures is currently a challenging subject for the development of supramolecular chemistry. Here we present a facile "breath figure" assembly process through the use of the self-assembled peptide building block diphenylalanine (L-Phe-L-Phe, FF). Macroporous honeycomb scaffolds were fabricated, and average pore size could be regulated, from (1.00±0.18) µm to (2.12±0.47) µm, through the use of different air speeds. It is indicated that the honeycomb formation is humidity-, solvent-, concentration-, and substrate-dependent. Moreover, water molecules introduced from "breath figure" intervene in the formation of hydrogen bonds during FF molecular self-assembly, which results in a hydrogen bond configuration transition from antiparallel ß sheet to parallel ß sheet. Meanwhile, as a result of the higher polarity of water molecules, the FF molecular array is transformed from laminar stacking into a hexagonal structure. These findings not only elucidate the FF molecule self-assembly process, but also strongly support the mechanism of breath figure array formation. Finally, human embryo skin fibroblast (ESF) culture experiments suggest that FF honeycomb scaffolds are an attractive biomaterial for growth of adherent cells with great potential applications in tissue engineering.

Physical and Chemical Sensors on the Basis of Laser-Induced Graphene: Mechanisms, Applications, and Perspectives.

Laser-induced graphene (LIG) is produced rapidly by directly irradiating carbonaceous precursors, and it naturally exhibits as a three-dimensional porous structure. Due to advantages such as simple preparation, time-saving, environmental friendliness, low cost, and expanding categories of raw materials, LIG and its derivatives have achieved broad applications in sensors. This has been witnessed in various fields such as wearable devices, disease diagnosis, intelligent robots, and pollution detection. However, despite LIG sensors having demonstrated an excellent capability to monitor physical and chemical parameters, the systematic review of synthesis, sensing mechanisms, and applications of them combined with comparison against other preparation approaches of graphene is still lacking. Here, graphene-based sensors for physical, biological, and chemical detection are reviewed first, followed by the introduction of general preparation methods for the laser-induced method to yield graphene. The preparation and advantages of LIG, sensing mechanisms, and the properties of different types of emerging LIG-based sensors are comprehensively reviewed. Finally, possible solutions to the problems and challenges of preparing LIG and LIG-based sensors are proposed. This review may serve as a detailed reference to guide the development of LIG-based sensors that possess properties for future smart sensors in health care, environmental protection, and industrial production.

Lipid coated mesoporous silica nanoparticles as photosensitive drug carriers.

This paper presents a strategy for the biofunctionalization of novel photosensitizer carriers, mesoporous silica nanoparticles (MSNs). After being calcined and absorbed with photosensitizers (hypocrellin B, HB), MSNs can be coated with a lipid layer. Transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) results proved that HB molecules can be loaded into MSN porous and lipid can coated on the surface of the nanoparticles. When co-cultured with cancer cells (MCF-7), MSNs can transport HB molecules into cells and present low cytotoxicity. With the introduction of a lipid layer, the efficiency of MSN uptake by cells can be improved. These intracellular HB-loaded MSN materials also present cytotoxicity to MCF-7 cells after light irradiation which indicates the materials can be used as good photosensitizer carriers in photodynamic therapy.

Assembled capsules transportation driven by motor proteins.

An active biomimetic system by integrating kinesin motor, microtubule, and man-made biomimetic microcapsule has been constructed. Biomimetic microcapsules were fabricated by using the layer-by-layer technique and could serve as cargos in this active biomimetic system. Both of the hollow and filled capsules as cargos can be transported by kinesin motors along microtubules. It may help to create kinesin-powered complex hybrid micro- and nanodevices.

A ZnO/porous GaN heterojunction and its application as a humidity sensor.

A heterojunction of ZnO/porous GaN (ZnO/PGAN) was fabricated and directly applied to a diode-type humidity sensor. ZnO disks were loaded onto PGAN using a spraying process. The structure and surface morphology of the ZnO/PGAN were characterized using X-ray diffraction and scanning electron microscopy. The heterojunction displayed an excellent diode nature, which was investigated using photoluminescence spectra and I-V characteristics. The excellent transport capability of ZnO/PGAN contributes to enhanced electron transfer, and hence results in high sensitivity and quick response/recovery properties under different relative humidity (RH) levels. In the range of 12-96% RH, a fast sensing response time as low as 7 s and a recovery time of 13 s can be achieved. The simple design of a ZnO/PGAN based humidity sensor highlights its potential in various applications.

Structure and Dimension Effects on the Performance of Layered Triboelectric Nanogenerators in Contact-Separation Mode.

A triboelectric nanogenerator (TENG) is a potential solution for providing high output power by continuously harvesting ambient energy, which is expected to sustainably charge a battery for the new era-the era of the Internet of things and sensor networks. Generally, the existence of parasitic capacitance has been considered to be harmful in its output performance. Here, we systematically investigate the effects of structure and dimension of a TENG on its performance from the point view of parasitic capacitance by fabricating two types of layered TENGs with considering the dissimilarity of the two dielectric materials, symmetrical (ABBA) and alternate (ABAB) layered structure (SYM-TENG and ALT-TENG). Theoretical models of the two types of layered TENGs are proposed for illustrating their differences in parasitic capacitances and output characteristics. Larger parasitic capacitance enables the TENG to accommodate higher triboelectric charge density while reducing the internal impedance and maximum power density. Furthermore, the parasitic capacitance will be enhanced with the decreasing dimension of the devices. The effect of parasitic capacitance on output characteristics of the two kinds of structures are verified in vacuum. Our findings not only establish an optimization methodology for the output performance of TENGs but also provide an insight into the process of triboelectrification.

Covalent Assembly of Amphiphilic Bola-Amino Acids into Robust and Biodegradable Nanoparticles for In Vitro Photothermal Therapy.

Organic photothermal sensitizers, such as indocyanine green (ICG), have been widely explored in photothermal therapy as a good substitute for inorganic materials owing to their advantageous biosafety and strong absorption in the near-infrared region. However, their intrinsic low stability and rapid clearance from the body requires further modification for efficient therapeutic application. In this work, we employed a covalent assembly strategy by covalently cross-linking genipin and a functional bola-amino acid to fabricate stable and degradable nanoparticles capable of loading ICG. The covalent assembly introduced strong covalent interactions in the assembly system together with functional linkers, which led to both enhanced stability and extended functionalities. This is distinguished from the conventional supramolecular strategy that relies only on weak noncovalent interactions. The functional building unit, consisting of phenylalanine and the disulfide bond, enables both good assembly and controllable degradation owing to the disulfide bond that responds to glutathione. The assembled nanoparticles show high stability, negligible toxicity, and considerable biodegradability. After loading ICG, the ICG-loaded nanoparticles possessed high photothermal conversion efficiency, and showed an enhanced photothermal effect in the near-infrared region. This covalent assembly strategy could be extended to various biomolecules containing a primary amino group for the fabrication of efficient and multifunctional nanomaterials used in biomedical applications.

Plasmonic nanoparticle-embedded poly(p-phenylene benzobisoxazole) nanofibrous composite films for solar steam generation.

High-performance floating film-based solar steam generation has received extensive attention for clean fresh water generation. Herein, we report high-strength nanoporous gold nanoparticle (AuNP)/poly(p-phenylene benzobisoxazole) nanofibre (PBONF) composite films that are capable of enhanced solar steam generation. The PBONFs were employed as building blocks to fabricate nanoporous PBONF multilayer composite films using a layer-by-layer assembly technique. These PBONF multilayer composite films then served as supports for depositing AuNPs. The resulting AuNP/PBONF composite films exhibit a high strength of 122 MPa and Young's modulus of 3.7 GPa, a broad spectrum photothermal effect, a mesoscopic structure, and a low thermal conductivity of 0.230 W m-1 K-1. Under one sun exposure, the AuNP/PBONF composite films exhibit an evaporation rate of 1.424 kg m-2 h-1 and a solar-vapor conversion efficiency of 83%. The AuNP/PBONF composite films are stable; therefore, they can be readily reused. These high-performance AuNP/PBONF composite films have potential for clean water generation under some extreme conditions such as space environments.

Zinc Oxide-Enhanced Piezoelectret Polypropylene Microfiber for Mechanical Energy Harvesting.

This paper reports zinc oxide (ZnO)-coated piezoelectret polypropylene (PP) microfibers with a structure of two opposite arc-shaped braces for enhanced mechanical energy harvesting. The ZnO film was coated onto PP microfibers via magnetron sputtering to form a ZnO/PP compound structure. Triboelectric Nanogenerator (TENG) based on ZnO/PP microfiber compound film was carefully designed with two opposite arc-shaped braces. The results of this study demonstrated that the mechanical energy collection efficiency of TENG based on piezoelectret PP microfiber was greatly enhanced by the coated ZnO and high-voltage corona charging method. We found that, with the step-increased distance of traveling for the movable carbon black electrode, an electrical power with an approximately quadratic function of distance was generated by this mechanical-electrical energy conversion, because more PP microfibers were connected to the electrode. Further, with a full contact condition, the peak of the generated voltage, current, and charges based on the ZnO/PP microfibers by this mechanical-electrical energy conversion with 1 m/s2 reached 120 V, 3 µA, and 49 nC, respectively. Moreover, a finger-tapping test was used to demonstrate that the ZnO/PP microfiber TENG is capable of lighting eight light-emitting diodes.

High performance lithium-sulfur batteries for storing pulsed energy generated by triboelectric nanogenerators.

Storing pulsed energy harvested by triboelectric nanogenerators (TENGs) from ambient mechanical motion is an important technology for obtaining sustainable, low-cost, and green power. Here, we introduce high-energy-density Li-S batteries with excellent performance for storing pulsed output from TENGs. The sandwich-structured sulfur composites with multi-walled carbon nanotubes and polypyrrole serve as cathode materials that suppress the shuttle effect of polysulfides and thus preserve the structural stability of the cathode during Li-ion insertion and extraction. The charging time and energy storage efficiency of the Li-S batteries are directly affected by the rotation rates of the TENGs. The average storage efficiency of the batteries for pulsed output from TENGs can exceed 80% and even reach 93% at low discharge currents. The Li-S batteries also show excellent rate performance for storing pulsed energy at a high discharge current rate of 5 C. The high storage efficiency and excellent rate capability and cyclability demonstrate the feasibility of storing and exploiting pulsed energy provided by TENGs and the potential of Li-S batteries with high energy storage efficiency for storing pulsed energy harvested by TENGs.