Polyurethane (PU) elastomer has been widely used due to its excellent mechanics, acid and alkali resistance, abrasion resistance, and other properties. However, obtaining simultaneous mechanically ...strong, flame‐retarded, transparent, and efficient self‐heal ability of PU elastomer is of great challenge due to the structural design. Here, a phosphorus/nitrogen‐containing Oxime chain extender (PSK‐2) was introduced into the synthesis of PU elastomers to obtain a transparent, flame‐retarded, self‐healable, mechanically strong PU elastomers. The PU elastomers exhibited high tensile strength of ~23.3 MPa, breaking strain of ~1693%, good flame retardancy with high LOI of ~29.2%, and UL‐94 V1 rating with the addition of 4.67 mmol (mass fraction 1.37 wt%) PSK2. Furthermore, the PUPSK2 elastomer material also had good healing ability up to 60% at room temperature and good transparency of 83.7% at 350–800 nm visible.
A novel polyurethane elastomers have been developed by addition of the phosphorus/nitrogen‐containing Oxime (PSK2) chain extende. The polyurethane elastomers showed simultaneous mechanically strong, flame‐retarded, transparent, and efficient self‐heal ability, We believe that this polymer will be widely used in the fields of high‐performance polymer materials by regulating the content of PSK2.
Herein, the Z11 argument tangent is proposed as a novel criterion for assessing energy loss (absorption) of the reciprocal two‐port networks composed of the shielding material. With a simple ...mathematical deduction, it can be found that the relationship between the network absorption and the Z11 argument tangent is inverted. The absorption decreases with increasing the Z11 argument tangent, and the Z11 argument is approximately equal to the power factor angle. Additionally, a series of samples are presented to verify their absorptions and the Z11 argument tangents. The numerical simulations on other works are also presented to calculate the Z11 argument tangent and validate the relationship between the Z11 argument tangent and electromagnetic absorption from another side. The experiment and simulation results agree well with that of the mathematical deduction. The findings can be applied in most passive shielding materials and provide a promising approach to guiding and developing absorption‐dominated electromagnetic shielding materials for next‐generation communication applications.
The Z11 argument tangent is proposed as a novel criterion to evaluate the energy loss of reciprocal passive two‐port networks composed of the shielding material. The relationship between the Z11 argument tangent and absorption is inverted: the absorption decreases with the Z11 argument tangent. The Z11 argument is approximately equal to the power factor angle.
As the key block of the application in the field of wearable electronic devices and next-generation robots, flexible piezoresistive sensors have attracted more and more attention. However, it is ...still a challenge to fabricate a piezoresistive sensor with high sensitivity, high stability, and a large detection range due to the traditional structure limitations. This paper proposed a flexible lateral-circuited piezoresistive sensor with a mechanotransduction structure. The lateral electrode design was achieved by using an AgNWs woven 3D network deposited on an elastic substrate. The zirconia microspheres were assembled in the cavities forming the mechanotransduction structure. It was found from theory and experiments that the microsphere arrays can weaken the load dissipation effect in the elastic substrate and magnify the effect of the mechanical stimulation. The as-obtained result of the deformation of the pressure sensor with zirconia microspheres arrays showed a differential expansion, which is contrary to the compression of the blank sample. Moreover, the sensor shows high linear sensitivity (1.7 kPa -1 ) in the detection range of 0 kPa - 120 kPa, fast response/recovery time of 23 ms / 22 ms, and relatively high stability (2400 cycles). On the other hand, the sensor also showed relatively high temperature and high humidity stabilities. This result verifies that the zirconia microsphere arrays have highly efficient mechanotransduction. This work provides a new perspective for designing and preparing high-sensitivity and wide-range pressure sensors.
Three-dimensional (3D) woven Ag nanowire (AgNW) grids have great potential for enhancing the mechanical stabilities, conductivity, and transmittance of flexible transparent electrodes (FTEs). ...However, it is a great challenge to control the formation of 3D woven AgNW grids on various substrates, especially the poly(dimethylsiloxane) (PDMS) substrate. This work presents a microtransfer-printing method for preparing a high-wettability poly(dimethylsiloxane) (PDMS) substrate to control the formation of 3D woven AgNW grids. The as-prepared PDMS substrate shows a high wettability performance. The surface structures of the PDMS substrate can control the sharp shrinkage of the ink membrane to give rise to a uniform liquid membrane evaporation behavior, which is the key factor for preparing a uniform 3D woven nanowire network. A thin uniform 3D woven AgNW network with a low sheet resistance of 24.3 Ω/□ and high transmittance of 92% was coated on the PDMS substrate. The networks directly coated the surface of the replicated PDMS, which simplified the peeling process and protected the networks from peeling strain and mechanical deformations. Moreover, the increment of resistance retained a small value (∼5%) when bending cycles reached 9,000. An alternating current electroluminescent (ACEL) device was prepared, and the uniform electroluminescence implies that a defect-free electrode has been fabricated. These results indicate that the as-prepared FTEs have excellent mechanical performance and great potential for flexible optoelectronic applications.
•A total of 21 CaHsp70 genes were identified in pepper.•The conserved CaHsp70 domain, motif compositions and cis-acting elements in promoters were analyzed.•The expression of all of the CaHsp70 genes ...was analyzed in different organs and heat stress.•The thermotolerance of Arabidopsis overexpressing CaHsp70-2 was analyzed.
Hsp70s function as molecular chaperones and are encoded by a multi-gene family whose members play a crucial role in plant response to stress conditions, and in plant growth and development. Pepper (Capsicum annuum L.) is an important vegetable crop whose genome has been sequenced. Nonetheless, no overall analysis of the Hsp70 gene family is reported in this crop plant to date. To assess the functionality of Capsicum annuum Hsp70 (CaHsp70) genes, pepper genome database was analyzed in this research. A total of 21 CaHsp70 genes were identified and their characteristics were also described. The promoter and transcript expression analysis revealed that CaHsp70s were involved in pepper growth and development, and heat stress response. Ectopic expression of a cytosolic gene, CaHsp70-2, regulated expression of stress-related genes and conferred increased thermotolerance in transgenic Arabidopsis. Taken together, our results provide the basis for further studied to dissect CaHsp70s’ function in response to heat stress as well as other environmental stresses.
Predicting and optimizing thermal conductivity of materials used in infrared thermal imaging sensors is an effective method to improve thermal isolation performance, which can substantially reduce ...the thermal crosstalk among pixels. This paper reports an electrospun P(VDF-TrFE) nanofiber film used as adiabatic support structure in thermal sensor array, and investigates its effect on imaging performance of thermal sensor. Based on solid heat transfer simulation, the thermal conductivities of electrospun P(VDF-TrFE) films with different packing ratios were theoretically calculated, showing a significant decrease compared with the spin-coated counterpart. The temperature increment of thermal sensor using nanofiber film with 43.71% packing ratio is calculated as 1.68 times higher than that using spin-coated film. An average temperature rise of 1.73 times was experimentally obtained, and the thermal response time was also reduced to half, compared with the sensor using spin-coated film. The method of improving thermal isolation performance using electrospun fibrous film could be of great advantage to high sensitivity infrared imaging sensor.
The Hsp20 genes are present in all plant species and play important roles in alleviating heat stress and enhancing plant thermotolerance by preventing the irreversible aggregation of denaturing ...proteins. However, very little is known about the CaHsp20 gene family in pepper (Capsicum annuum L.), an important vegetable crop with character of temperate but thermosensitive. In this study, a total of 35 putative pepper Hsp20 genes (CaHsp20s) were identified and renamed on the basis of their molecular weight, and then their gene structure, genome location, gene duplication, phylogenetic relationship, and interaction network were also analyzed. The expression patterns of CaHsp20 genes in four different tissues (root, stem, leaf, and flower) from the thermotolerant line R9 under heat stress condition were measured using semi-quantitative RT-PCR. The transcripts of most CaHsp20 genes maintained a low level in all of the four tissues under normal temperature condition, but were highly induced by heat stress, while the expression of CaHsp16.6b, 16.7, and 23.8 were only detected in specific tissues and were not so sensitive to heat stress like other CaHsp20 genes. In addition, compared to those in thermotolerant line R9, the expression peak of most CaHsp20 genes in thermosensitive line B6 under heat stress was hysteretic, and several CaHsp20 genes (CaHsp16.4, 18.2a, 18.7, 21.2, 22.0, 25.8, and 25.9) showed higher expression levels in both line B6 and R9. These data suggest that the CaHsp20 genes may be involved in heat stress and defense responses in pepper, which provides the basis for further functional analyses of CaHsp20s in the formation of pepper acquired thermotoleance.
Mutations within the
gene, which encodes a key postsynaptic density (PSD) protein at glutamatergic synapses, contribute to the genetic etiology of defined autism spectrum disorders (ASDs), including ...Phelan-McDermid syndrome (PMS) and intellectual disabilities (ID). Although there are a series of genetic mouse models to study
gene in ASDs, there are few rat models with species-specific advantages. In this study, we established and characterized a novel rat model with a deletion spanning exons 11-21 of
, leading to a complete loss of the major SHANK3 isoforms. Synaptic function and plasticity of
-deficient rats were impaired detected by biochemical and electrophysiological analyses.
-depleted rats showed impaired social memory but not impaired social interaction behaviors. In addition, impaired learning and memory, increased anxiety-like behavior, increased mechanical pain threshold and decreased thermal sensation were observed in
-deficient rats. It is worth to note that
-deficient rats had nearly normal levels of the endogenous social neurohormones oxytocin (OXT) and arginine-vasopressin (AVP). This new rat model will help to further investigate the etiology and assess potential therapeutic target and strategy for
-related neurodevelopmental disorders.
Heat shock factors (Hsfs) play crucial roles in plant developmental and defence processes. The production and quality of pepper (Capsicum annuum L.), an economically important vegetable crop, are ...severely reduced by adverse environmental stress conditions, such as heat, salt and osmotic stress. Although the pepper genome has been fully sequenced, the characterization of the Hsf gene family under abiotic stress conditions remains incomplete.
A total of 25 CaHsf members were identified in the pepper genome by bioinformatics analysis and PCR assays. They were grouped into three classes, CaHsfA, B and C, based on highly conserved Hsf domains, were distributed over 11 of 12 chromosomes, with none found on chromosome 11, and all of them, except CaHsfA5, formed a protein-protein interaction network. According to the RNA-seq data of pepper cultivar CM334, most CaHsf members were expressed in at least one tissue among root, stem, leaf, pericarp and placenta. Quantitative real-time PCR assays showed that all of the CaHsfs responded to heat stress (40 °C for 2 h), except CaHsfC1 in thermotolerant line R9 leaves, and that the expression patterns were different from those in thermosensitive line B6. Many CaHsfs were also regulated by salt and osmotic stresses, as well as exogenous Ca(2+), putrescine, abscisic acid and methyl jasmonate. Additionally, CaHsfA2 was located in the nucleus and had transcriptional activity, consistent with the typical features of Hsfs. Time-course expression profiling of CaHsfA2 in response to heat stress revealed differences in its expression level and pattern between the pepper thermosensitive line B6 and thermotolerant line R9.
Twenty-five Hsf genes were identified in the pepper genome and most of them responded to heat, salt, osmotic stress, and exogenous substances, which provided potential clues for further analyses of CaHsfs functions in various kinds of abiotic stresses and of corresponding signal transduction pathways in pepper.
Flexible strain sensor has promising features in successful application of health monitoring, electronic skins and smart robotics,
etc
. Here, we report an ultrasensitive strain sensor with a novel ...crack-wrinkle structure (CWS) based on graphite nanoplates (GNPs)/thermoplastic urethane (TPU)/polydimethylsiloxane (PDMS) nanocomposite. The CWS is constructed by pressing and dragging GNP layer on TPU substrate, followed by encapsulating with PDMS as a protective layer. On the basis of the area statistics, the ratio of the crack and wrinkle structures accounts for 31.8% and 9.5%, respectively. When the sensor is stretched, the cracks fracture, the wrinkles could reduce the unrecoverable destruction of cracks, resulting in an excellent recoverability and stability. Based on introduction of the designed CWS in the sensor, the hysteresis effect is limited effectively. The CWS sensor possesses a satisfactory sensitivity (GF = 750 under 24% strain), an ultralow detectable limit (strain = 0.1%) and a short respond time of 90 ms. For the sensing service behaviors, the CWS sensor exhibits an ultrahigh durability (high stability > 2×10
4
stretching-releasing cycles). The excellent practicality of CWS sensor is demonstrated through various human motion tests, including vigorous exercises of various joint bending, and subtle motions of phonation, facial movements and wrist pulse. The present CWS sensor shows great developing potential in the field of cost-effective, portable and high-performance electronic skins.
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