In the development of next‐generation materials with enhanced thermal properties, biological systems in nature provide many examples that have exceptional structural designs and unparalleled ...performance in their thermal or nonthermal functions. Bioinspired engineering thus offers great promise in the synthesis and fabrication of thermal materials that are difficult to engineer through conventional approaches. In this review, recent progress in the emerging area of bioinspired advanced materials for thermal science and technology is summarized. State‐of‐the‐art developments of bioinspired thermal‐management materials, including materials for efficient thermal insulation and heat transfer, and bioinspired materials for thermal/infrared detection, are highlighted. The dynamic balance of bioinspiration and practical engineering, the correlation of inspiration approaches with the targeted applications, and the coexistence of molecule‐based inspiration and structure‐based inspiration are discussed in the overview of the development. The long‐term outlook and short‐term focus of this critical area of advanced materials engineering are also presented.
Bioinspired engineering of thermal materials provides a promising approach in developing advanced thermal material systems that are complementary to traditional engineering approaches. With the further understanding of complex biological systems developed through billions of years of evolution, this emerging field of materials engineering offers a new paradigm in the design and fabrication of next‐generation thermal material systems.
Plasmonic gold nanoparticles self‐assembled at the air–water interface to produce an evaporative surface with local control inspired by skins and plant leaves. Fast and efficient evaporation is ...realized due to the instant and localized plasmonic heating at the evaporative surface. The bio‐inspired evaporation process provides an alternative promising approach for evaporation, and has potential applications in sterilization, distillation, and heat transfer.
Tremendous progress has been made during the past decade toward the design of nano/micromotors with high biocompatibility, multifunctionality, and efficient propulsion in biological fluids, which ...collectively have led to the initial investigation of in vivo biomedical applications of these synthetic motors. Despite these recent advances in micromotor designs and mechanistic research, significant effort is needed to develop appropriate formulations of micromotors to facilitate their in vivo administration and thus to better test their in vivo applicability. Herein, we present a micromotor pill and demonstrate its attractive use as a platform for in vivo oral delivery of active micromotors. The micromotor pill is comprised of active Mg-based micromotors dispersed uniformly in the pill matrix, containing inactive (lactose/maltose) excipients and other disintegration-aiding (cellulose/starch) additives. Our in vivo studies using a mouse model show that the micromotor pill platform effectively protects and carries the active micromotors to the stomach, enabling their release in a concentrated manner. The micromotor encapsulation and the inactive excipient materials have no effects on the motion of the released micromotors. The released cargo-loaded micromotors propel in gastric fluid, retaining the high-performance characteristics of in vitro micromotors while providing higher cargo retention onto the stomach lining compared to orally administrated free micromotors and passive microparticles. Furthermore, the micromotor pills and the loaded micromotors retain the same characteristics and propulsion behavior after extended storage in harsh conditions. These results illustrate that combining the advantages of traditional pills with the efficient movement of micromotors offer an appealing route for administrating micromotors for potential in vivo biomedical applications.
Monitoring the effects of daily activities on the physiological responses of the body calls for wearable devices that can simultaneously track metabolic and haemodynamic parameters. Here we describe ...a non-invasive skin-worn device for the simultaneous monitoring of blood pressure and heart rate via ultrasonic transducers and of multiple biomarkers via electrochemical sensors. We optimized the integrated device so that it provides mechanical resiliency and flexibility while conforming to curved skin surfaces, and to ensure reliable sensing of glucose in interstitial fluid and of lactate, caffeine and alcohol in sweat, without crosstalk between the individual sensors. In human volunteers, the device captured physiological effects of food intake and exercise, in particular the production of glucose after food digestion, the consumption of glucose via glycolysis, and increases in blood pressure and heart rate compensating for oxygen depletion and lactate generation. Continuous and simultaneous acoustic and electrochemical sensing via integrated wearable devices should enrich the understanding of the body's response to daily activities, and could facilitate the early prediction of abnormal physiological changes.
Sphingosine-1-phosphate (S1P), a potent signalling lipid secreted by red blood cells and platelets, plays numerous biologically significant roles. However, the identity of its long-sought exporter is ...enigmatic. Here we show that the major facilitator superfamily transporter 2b (Mfsd2b), an orphan transporter, is essential for S1P export from red blood cells and platelets. Comprehensive lipidomic analysis indicates a dramatic and specific accumulation of S1P species in Mfsd2b knockout red blood cells and platelets compared with that of wild-type controls. Consistently, biochemical assays from knockout red blood cells, platelets, and cell lines overexpressing human and mouse Mfsd2b proteins demonstrate that Mfsd2b actively exports S1P. Plasma S1P level in knockout mice is significantly reduced by 42-54% of that of wild-type level, indicating that Mfsd2b pathway contributes approximately half of the plasma S1P pool. The reduction of plasma S1P in knockout mice is insufficient to cause blood vessel leakiness, but it does render the mice more sensitive to anaphylactic shock. Stress-induced erythropoiesis significantly increased plasma S1P levels and knockout mice were sensitive to these treatments. Surprisingly, knockout mice exhibited haemolysis associated with red blood cell stomatocytes, and the haemolytic phenotype was severely increased with signs of membrane fragility under stress erythropoiesis. We show that S1P secretion by Mfsd2b is critical for red blood cell morphology. Our data reveal an unexpected physiological role of red blood cells in sphingolipid metabolism in circulation. These findings open new avenues for investigating the signalling roles of S1P derived from red blood cells and platelets.
Transforming natural cells into functional biocompatible robots capable of active movement is expected to enhance the functions of the cells and revolutionize the development of synthetic ...micromotors. However, present cell-based micromotor systems commonly require the propulsion capabilities of rigid motors, external fields, or harsh conditions, which may compromise biocompatibility and require complex actuation equipment. Here, we report on an endogenous enzyme-powered Janus platelet micromotor (JPL-motor) system prepared by immobilizing urease asymmetrically onto the surface of natural platelet cells. This Janus distribution of urease on platelet cells enables uneven decomposition of urea in biofluids to generate enhanced chemophoretic motion. The cell surface engineering with urease has negligible impact on the functional surface proteins of platelets, and hence, the resulting JPL-motors preserve the intrinsic biofunctionalities of platelets, including effective targeting of cancer cells and bacteria. The efficient propulsion of JPL-motors in the presence of the urea fuel greatly enhances their binding efficiency with these biological targets and improves their therapeutic efficacy when loaded with model anticancer or antibiotic drugs. Overall, asymmetric enzyme immobilization on the platelet surface leads to a biogenic microrobotic system capable of autonomous movement using biological fuel. The ability to impart self-propulsion onto biological cells, such as platelets, and to load these cellular robots with a variety of functional components holds considerable promise for developing multifunctional cell-based micromotors for a variety of biomedical applications.
This study aimed to investigate the effect of the prophylactic feeding of Clostridium butyricum (CB), Saccharomyces cerevisiae (SC), and their mixture before the onset of heat stress on the rumen ...fermentation and growth performance of goats, and subsequently, on heat stress status. Forty-eight male Macheng Black × Boer crossed goats (22.25 ± 4.26 kg) were divided into four groups—the control group (fed the basal diet), and the CB (0.05% CB added to the basal diet), SC (0.60% SC added to the basal diet), and Mix (0.05% CB and 0.60% SC added to the basal diet) groups—and fed for fourteen days. Then, these goats were kept in a heat stress environment (with a temperature−humidity index of 87.04) for fourteen days. Then, the parameters of rumen fermentation and growth performance were measured. The results showed that the pH values, the activities of cellulolytic enzymes (avicelase, CMCaes, cellobiase, and xylanase), and the concentrations of ammonia-N, total volatile fatty acid, acetic acid, propionic acid, and butyric acid were significantly increased (p < 0.05) in the rumens of the CB, SC, and Mix groups compared to those of the control group. Moreover, the average daily gain and the digestibility of dry matter, neutral detergent fiber, and acid detergent fiber were significantly increased (p < 0.05) in the CB, SC, and Mix groups compared to those of the control group. These results suggest that these two probiotics and their mixture effectively alleviate the adverse effects of heat stress on rumen fermentation and growth performance via prophylactic feeding.
Increasing evidence demonstrates that hexavalent tungsten (W(VI)) can affect the survival of various organisms. This study explored the influences of pH and common anions on W(VI) toxicity on wheat ...and established a biotic ligand model (BLM) for predicting W(VI) toxicity. It was found that as the pH value increased from 6.0 to 8.5, the EC50W(VI)T values increased greatly from 24.7 to 46.6 μM, indicating that increasing pH values can alleviate W(VI) toxicity. A linear relationship between the ratio of HWO4- to WO42- and EC50{WO42-} indicated that WO42- and HWO4- were two toxic species of W(VI). The toxicity of W(VI) decreased as the H2PO4- and SO42- activities increased but not when the activities of Cl- and NO3- increased, demonstrating that the competition from H2PO4- and SO42- significantly influenced W(VI) toxicity. By applying BLM theory, the stability constants for HWO4-, WO42-, H2PO4-, and SO42- were obtained: logKWO4BL = 4.08, logKHWO4BL = 6.44, logKH2PO4BL = 2.09, and logKSO4BL = 1.87, fWBL50% = 0.300, β = 1.99. Results demonstrated that BLM outperformed the free metal activity model(FIAM) in predicting W(VI) toxicity when considering the influences of pH, W(VI) species, and H2PO4- and SO42- competition for active ligand sites.
•WO42- and HWO4- were the two major toxic species devoted to W(IV) toxicity.•HWO4- had a better binding affinity than WO42-.•H2PO4- and SO42- can alleviate W(IV) toxicity.•A developed BLM can predict W(VI) toxicity to wheat root elongation.
The time-frequency spectrum of the vibration signal obtained based on the time-frequency transformation algorithm can fully reflect the energy distribution at any time-frequency coordinate. But this ...characteristic is not easy to be insight and generalized by the human eye, especially in the era of big data, in the face of massive data and rapid processing. During the research, we found that this information can be clearly expressed in the histogram of oriented gradient (HOG) feature of the time-frequency spectrum. Therefore, the time-frequency spectrum support vector machine classifier based on the HOG feature of the vibration signal has considerable feasibility. This article had conducted in-depth research on this idea, determined the advantages of wavelet time-frequency spectrum for signal recognition, and further selected wavelet basis and kernel function. A comprehensive test of the HOG parameters had finally achieved a good recognition effect. The comprehensive recognition accuracy of the algorithm for the impact and vibration signals collected in this paper was stable at about 96%. The research results will be applied to the future smart city vibration monitoring system. On the other hand, it may provide a new idea to improve the accuracy of the current battlefield target recognition system.
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