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1.
J Integr Neurosci ; 22(2): 47, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36992589

RESUMO

OBJECTIVE: This study aimed to observe the clinical efficacy of long-term spinal nerve posterior ramus pulsed radiofrequency (PRF) in treating subacute herpes zoster neuralgia (HZN). METHODS: A total of 120 patients with subacute HZN in the thoracolumbar region and back were equally randomized to the conventional PRF group (P group, n = 60), with a pulse of 180 s, or to the long-term PRF group (LP group, n = 60), with a pulse of 600 s. The patients' baseline characteristics, the incidence rate of postherpetic neuralgia (PHN), and the dose of analgesics were compared between the two groups. RESULTS: Based on the pain-rating index (PRI), the PRI-sensory, PRI-affective, visual analogue scale, and present pain intensity scores in the two groups were lower at T2, T3, and T4 time points than at the T1 time point after treatment (p < 0.05). After 2 months, the dose of analgesics was significantly lower in the LP group than in the P group (p < 0.05), and the incidence of PHN was considerably lower. CONCLUSIONS: Long-term spinal nerve posterior ramus PRF is a more effective treatment strategy for subacute HZN than conventional PRF. It can effectively prevent the occurrence of PHN.


Assuntos
Herpes Zoster , Neuralgia Pós-Herpética , Neuralgia , Tratamento por Radiofrequência Pulsada , Humanos , Estudos Prospectivos , Neuralgia/terapia , Neuralgia Pós-Herpética/terapia , Herpes Zoster/terapia , Analgésicos , Nervos Espinhais
2.
Small ; 14(35): e1801657, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30058286

RESUMO

Nature has long offered human beings with useful materials. Herein, plant materials including flowers and leaves have been directly used as the dielectric material in flexible capacitive electronic skin (e-skin), which simply consists of a dried flower petal or leaf sandwiched by two flexible electrodes. The plant material is a 3D cell wall network which plays like a compressible metamaterial that elastically collapses upon pressing plus some specific surface structures, and thus the device can sensitively respond to pressure. The device works over a broad-pressure range from 0.6 Pa to 115 kPa with a maximum sensitivity of 1.54 kPa-1 , and shows high stability over 5000 cyclic pressings or bends. The natural-material-based e-skin has been applied in touch sensing, motion monitoring, gas flow detection, and the spatial distribution of pressure. As the foam-like structure is ubiquitous in plants, a general strategy for a green, cost-effective, and scalable approach to make flexible e-skins is offered here.


Assuntos
Eletricidade , Plantas/química , Dispositivos Eletrônicos Vestíveis , Plantas/ultraestrutura , Maleabilidade
3.
Langmuir ; 33(40): 10577-10587, 2017 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-28930633

RESUMO

The effect of particle parameters [aspect ratio (AR) and concentration] and flow conditions (gap spacing and shear rate) on droplet orientation deformation behavior in polystyrene (PS) particle-filled binary polymeric emulsions is investigated by using a rheo-optical technique and confocal microscopy. Interesting vorticity orientation behavior is achieved by tailoring experimental conditions to yield rigid anisotropic droplets during slow confined shear flow. PS ellipsoids with a high AR are found to reside both at the fluid interface in a monolayer side-on state and inside droplets, leading to the formation of rigid anisotropic droplets because of the interfacial/bulk jamming effect at appropriate particle concentrations. In unconfined bulk samples, droplets with a vorticity orientation can also be observed under the wall migration effect and confinement effect arising from nearby droplets. However, the overly strong wall confinement effect remarkably facilitates the coalescence of vorticity-aligned droplets during slow shear, eventually leading to the formation of a long stringlike phase aligning along the flow direction. High shear rates generate refined droplets with lower particle coverage and weak rigidity, which restrain the formation of anisotropic droplets and thus suppress the droplet vorticity orientation.

4.
Ecol Evol ; 14(8): e70164, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39130094

RESUMO

Functional traits reflect plants' adaptability to their environment, and environmental gradients influence their distribution. But few studies have investigated the link between these traits and species substitution patterns or the relevant ecological factors. We measured the aboveground (leaf) and belowground (root) functional traits of Stipa species in 17 plots across natural grasslands in Ningxia in Northern China. Redundancy analysis was used to explore the relationships between Stipa's functional traits and its species substitution distribution. Then, on the species substitution gradient, principal component analysis (PCA) was used to verify and quantify the leaf economic spectrum (LES), root economic spectrum (RES), and whole-plant economic spectrum (WPES), with the relation between these spectra investigated by fitting standardized major axis regressions. The effects of aboveground, belowground, and whole-plant ecological factors were quantified and ranked by variance decomposition and hierarchical partitioning. Our results showed that functional traits drive the substitution distribution of Stipa species, in being variously coupled with its desert, typical, and meadow steppe habitat types. The leaf, root, and whole-plant economic spectra of Stipa species in desert steppe exhibit a "quick investment-acquisition" strategy. In typical steppe, the leaf and whole-plant economic spectra of Stipa species correspond to a "fast investment-acquisition" strategy, whereas the root economic spectrum adopts a "slow investment-acquisition" strategy. On meadow steppe, the leaf, root, and whole-plant economic spectra of Stipa species similarly adopt a "slow investment-acquisition" strategy. Finally, when considering the environmental factors involved, we find that the substitution distribution of Stipa spp. is chiefly a response to shifting soil patterns, these mainly driven by soil total nitrogen and nitrogen/phosphorus ratio. Collectively, these findings provide an important reference for the ecological restoration and reconstruction of grassland ecosystems, to better understand the relationship between plant functional traits and ecological niche attributes, and thus guide the reasonable restoration of grassland vegetation.

5.
Nanoscale ; 16(14): 6961-6972, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38362794

RESUMO

The complex hybrid nanostructure combining a two-dimensional (2D) conductive material and a hierarchical nanoscale skeleton plays an important role to enhance its piezoresistive sensitivity. To construct such a novel hybrid nanostructure, a piezoresistive sensor was designed with the following strategy to take the full advantages of 2D MXene and nanoscale fibrils: ethylene oxide propylene oxide random copolymer (EOPO) was grafted to ethylene-vinyl alcohol (EVOH) molecular chains and was foamed by an environmentally-friendly supercritical CO2 (scCO2) foaming technology to fabricate abundant nanoscale EVOH fibrils surrounding micropores; MXene featured as a 2D structure of nanoscale size that strongly interacted with this hierarchical nanoscale skeleton, and MXene not only convolved on nanoscale fibrils to generate bumps but also MXene covered the end of broken fibrils to build spots, and furthermore, MXene adhered on the soft EOPO embedded EVOH fibrils to form wrinkles, in which these bumps, spots and wrinkles assembled by highly conductive 2D MXene offered sufficient contacts when the hierarchical nanoscale skeleton was compressed (these contacts would then destruct when the skeleton recovered). Such an elaborated hybrid nanostructural design exploits the full potential of 2D MXene and hence achieves an ultra-high sensitivity of 6895.0 kPa-1 for this fabricated MXene piezoresistive sensor.

6.
ACS Nano ; 18(22): 14672-14684, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38760182

RESUMO

Flexible sensing systems (FSSs) designed to measure plantar pressure can deliver instantaneous feedback on human movement and posture. This feedback is crucial not only for preventing and controlling diseases associated with abnormal plantar pressures but also for optimizing athletes' postures to minimize injuries. The development of an optimal plantar pressure sensor hinges on key metrics such as a wide sensing range, high sensitivity, and long-term stability. However, the effectiveness of current flexible sensors is impeded by numerous challenges, including limitations in structural deformability, mechanical incompatibility between multifunctional layers, and instability under complex stress conditions. Addressing these limitations, we have engineered an integrated pressure sensing system with high sensitivity and reliability for human plantar pressure and gait analysis. It features a high-modulus, porous laminated ionic fiber structure with robust self-bonded interfaces, utilizing a unified polyimide material system. This system showcases a high sensitivity (156.6 kPa-1), an extensive sensing range (up to 4000 kPa), and augmented interfacial toughness and durability (over 150,000 cycles). Additionally, our FSS is capable of real-time monitoring of plantar pressure distribution across various sports activities. Leveraging deep learning, the flexible sensing system achieves a high-precision, intelligent recognition of different plantar types with a 99.8% accuracy rate. This approach provides a strategic advancement in the field of flexible pressure sensors, ensuring prolonged stability and accuracy even amidst complex pressure dynamics and providing a feasible solution for long-term gait monitoring and analysis.


Assuntos
Pressão , Humanos , Análise da Marcha/instrumentação , Análise da Marcha/métodos , Dispositivos Eletrônicos Vestíveis , Marcha/fisiologia , Pé/fisiologia
7.
Ying Yong Sheng Tai Xue Bao ; 35(7): 1807-1814, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39233409

RESUMO

Soil microorganisms play a crucial role as a link between vegetation and soil nutrient cycling. However, it is unclear how vegetation and soil influence microbial community during the ecological restoration process of the Mu Us Desert. Using phospholipid fatty acid (PLFA) markers and integrating shrub, herbaceous plants, and soil factors, we explored the characteristics and regulations of soil microbial community changes. In this study, we used and took the soil after 10, 30, 50, and 70 years of Caragana korshinskii sand-fixing forest restoration, with moving dunes as a control (0 year). The results showed that the ecological restoration effect index increased significantly with the increase of recovery years. The total PLFA contents in 0, 10, 30, 50, and 70 years were 47.75, 55.89, 63.53, 67.23, and 82.29 nmol·g-1, respectively. With the increases of ecological restoration index, the biomass of fungi and bacteria, as well as the ratio of Gram-positive to Gram-negative bacteria, all showed significant increase, while the biomass of Gram-positive and Gram-negative bacterial communities, and the ratio of fungi to bacteria, demonstrated significant decrease. Shrub, herbaceous plants, and soil factors could explain 72.4% of the vari-ation of soil microbial community composition, with higher contribution of soil factors than vegetation factors. The total content of phospholipid fatty acids of soil microbial community in Mu Us Desert increased with the increases of restoration years. Soil water content, pH, total nitrogen, and soil organic carbon were the main driving factors affecting the characteristics of soil microbial community. With the increases of restoration years of C. korshinskii sand-fixation forests in the Mu Us Desert, there were significant changes in the structure of soil microbial communities, which were primarily driven by soil factors.


Assuntos
Caragana , Clima Desértico , Microbiota , Microbiologia do Solo , Caragana/crescimento & desenvolvimento , China , Florestas , Fosfolipídeos/análise , Recuperação e Remediação Ambiental/métodos , Solo/química , Areia , Ácidos Graxos/análise , Conservação dos Recursos Naturais
8.
Plants (Basel) ; 13(13)2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38999624

RESUMO

Light, as a critical environmental factor, plays a pivotal role in photosynthesis, ultimately influencing the timing of bud flush in tea plants. However, the synergistic effects of different photoperiods and light qualities on the timing of bud flush in the albino tea cultivar 'HuangKui' (later germination variety) remain unknown. Thus, the objective of this study was to investigate the effects of different photoperiods (12L/12D, 14L/10D, 16L/8D, and 18L/6D, where L = the number of daylight hours and D = the number of hours of darkness) and ratios of red (R) to blue (B) light (R/B 1:1, R/B 1:2, R/B 1:3, and R/B 2:1) on the germination and growth of the albino tea variety 'HuangKui'. In our study, we examined how different photoperiods and red light and blue light affected tea germination and growth by investigating the timing of bud flush, photosynthesis, chlorophyll content, and growth indicators. First, our study showed that 'HuangKui' germinated 4 days, 2 days, and 1 day earlier under the 16L/8D photoperiod at the one bud and one leaf period compared with plants cultivated under the 12L/12D, 14L/10D, and 18L/6D photoperiods under light simulating the solar spectrum. Also, the growth of 'HuangKui' was maximumly promoted under the 16L/8D photoperiod treatment. Additionally, the earliest germination of 'HuangKui' was observed for the 16L/8D photoperiod under the R/B 2:1 (red/blue) treatment compared with the other treatments. Moreover, the greatest plant height, length of the new shoots, and new leaf areas were detected in the albino tea variety 'HuangKui' under R/B 2:1. Moreover, the contents of auxin (indole acetic acid, IAA) and trans-zeatin (tZ) under R/B 2:1 were significantly higher than those under the R/B 1:1 and control treatments with the 16L/8D photoperiod. Additionally, the auxin-related expression levels of CsIAA13, CsGH3.1, CsAUX1, and CsARF2 under the R/B 2:1 treatment were significantly higher than those in the control. The expression of CsARR-B, a positive regulator of cytokinin-related genes, was significantly higher under the R/B 2:1 treatment than under the control treatment, while the opposite result was found for the expression of the negative regulator CsARR-A. Therefore, the R/B 2:1 treatment with the 16L/8D photoperiod was an appropriate means of timing the bud flush for the albino tea variety 'HuangKui', which may be related to IAA or tZ signal transduction. In conclusion, our research offers a novel lighting strategy that promotes the germination and growth of albino tea cultivars.

9.
Ying Yong Sheng Tai Xue Bao ; 35(4): 909-916, 2024 Apr 18.
Artigo em Zh | MEDLINE | ID: mdl-38884225

RESUMO

The stoichiometric characteristics of leaves can reflect environmental adaptation of plants, and thus the study of the relationship between them is helpful for exploring plant adaptation strategies. In this study, taking the national second-level key protection species, Ammopiptanthus mongolicus, as the research object, we set up 26 plots to collect samples, and measured the content of carbon (C), nitrogen (N), phosphorus (P) and water use efficiency (WUE) of leaves. We analyzed the relationship between leaf stoichiometric characteristics and WUE, and quantified the contributions of soil, climate, and water use efficiency to the variations of leaf stoichiometry. The results showed that C, N, and P contents in the leaves were (583.99±27.93), (24.31±2.09), and (1.83±0.06) mg·g-1, respectively. The coefficients of variation were 4.8%, 8.6%, and 3.2%, respectively, all belonging to weak variability, indicating that foliar contents of C, N and P tended to a certain stable value. The average value of N:P was 13.3, indicating that the growth of A. mongolicus was mainly limited by N. WUE was not correlated with leaf C content, but was significantly positively correlated with leaf N and P contents and N:P, and significantly negatively correlated with C:N and C:P, indicating that there was a linear synergistic trend between WUE and leaf nutrient content. The main factors influencing leaf C content and C:P were climatic factors, the leaf N content and N:P were mainly affected by soil factors, and the water use efficiency mainly affected leaf P content and C:N, indicating that the driving factors of different stoichiometric characteristics were different. The results could help eva-luate the habitat adaptation of desert plants, which would provide a theoretical basis for the conservation and management of A. mongolicus.


Assuntos
Carbono , Nitrogênio , Fósforo , Folhas de Planta , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/crescimento & desenvolvimento , China , Nitrogênio/análise , Nitrogênio/metabolismo , Fósforo/análise , Fósforo/metabolismo , Carbono/análise , Carbono/metabolismo , Ecossistema , Água/análise , Água/metabolismo , Água/química , Adaptação Fisiológica , Solo/química
10.
Nat Commun ; 14(1): 1382, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36914642

RESUMO

Olivine is the dominant phenocryst or xenocryst of Hawaiian tholeiitic basalts, and the general consensus is that lavas with MgO concentrations from 7.5 to about 15 weight percent were derived from their primary magmas, which contain ~18-20 weight percent MgO, by only olivine crystallization. However, the major element composition of estimated primary magmas through olivine crystallization correction is inconsistent with direct partial melting of either mantle peridotite or its hybrid with subducted oceanic crust. Our melting experiments on peridotite-derived melt composition show that this discrepancy can be resolved if the primary magmas experienced two other processes before abundant olivine fractionation. First, the primary magmas experienced crystallization of clinopyroxene and garnet in the chamber at the base of the lithosphere (approximately the depths of 90-100 km). Second, the evolved magmas re-equilibrated with harzburgite when passing through the lithospheric mantle (approximately the depths of 60-10 km). Different from the isotopic evidence, the major and rare earth element compositions of Hawaiian post-shield alkali basalts and shield tholeiites suggest that they form from the same source by assimilating different amounts of orthopyroxene.

11.
Int J Mol Med ; 52(1)2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37232339

RESUMO

Osteoarthritis (OA) is a progressive joint disorder, which is principally characterized by the degeneration and destruction of articular cartilage. The cytoskeleton is a vital structure that maintains the morphology and function of chondrocytes, and its destruction is a crucial risk factor leading to chondrocyte degeneration and OA. Hyaluronan synthase­2 (HAS­2) is a key enzyme in synthesizing hyaluronic acid (HA) in vivo. The synthesis of high molecular weight HA catalyzed by HAS­2 serves a vital role in joint movement and homeostasis; however, it is unclear what important role HAS­2 plays in maintaining chondrocyte cytoskeleton morphology and in cartilage degeneration. The present study downregulated the expression of HAS­2 by employing 4­methylumbelliferone (4­MU) and RNA interference. In vitro experiments, including reverse transcription­quantitative PCR, western blotting, laser scanning confocal microscopy and flow cytometry were subsequently performed. The results revealed that downregulation of HAS­2 could activate the RhoA/ROCK signaling pathway, cause morphological abnormalities, decrease expression of the chondrocyte cytoskeleton proteins and promote chondrocyte apoptosis. In vivo experiments, including immunohistochemistry and Mankin's scoring, were performed to verify the effect of HAS­2 on the chondrocyte cytoskeleton, and it was revealed that inhibition of HAS­2 could cause cartilage degeneration. In conclusion, the present results revealed that downregulation of HAS­2 could activate the RhoA/ROCK pathway, cause abnormal morphology and decrease chondrocyte cytoskeleton protein expression, leading to changes in the signal transduction and biomechanical properties of chondrocytes, promotion of chondrocyte apoptosis and the induction of cartilage degeneration. Moreover, the clinical application of 4­MU may cause cartilage degeneration. Therefore, targeting HAS­2 may provide a novel therapeutic strategy for delaying chondrocyte degeneration, and the early prevention and treatment of OA.


Assuntos
Cartilagem Articular , Osteoartrite , Humanos , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Citoesqueleto/metabolismo , Regulação para Baixo , Hialuronan Sintases/metabolismo , Osteoartrite/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Transdução de Sinais
12.
Ying Yong Sheng Tai Xue Bao ; 34(3): 664-670, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37087649

RESUMO

To explore the stoichiometric characteristics of C, N and P and adaptive mechanism of mosses in mountain forest ecosystems, we set up 15 plots along the altitude gradient in Picea crassifolia forest in Helan Mountains, Ningxia. We analyzed the C:N:P stoichiometry of moss aboveground tissues and its relationship with environmental factors. The results showed the mean values of C, N and P concentration in moss aboveground tissues were 336.67, 20.31 and 0.66 mg·g-1, respectively. The mean value of aboveground tissue N:P was 33.4, indicating that the growth of mosses was limited by P. The C concentration in the aboveground tissues of mosses was positively correlated with soil total nitrogen concentration and negatively correlated with soil total phosphorus concentration. The N concentration in aboveground tissues of mosses was significantly negatively correlated with soil organic carbon and soil total nitrogen concentrations. Results of redundancy analysis showed that the interpretation rate of environmental factors on the stoichiometry was 48.5%, with canopy closure, soil total nitrogen and soil total phosphorus as the main factors. Canopy closure was the main environmental factor affecting the growth of mosses in P. crassifolia forest in Helan Mountains. High canopy closure facilitated the growth of mosses.


Assuntos
Briófitas , Picea , Ecossistema , Carbono/análise , Solo , Florestas , China , Nitrogênio/análise , Fósforo/análise
13.
Polymers (Basel) ; 15(3)2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36771893

RESUMO

Bismaleimide (BMI) resin is an excellent performance resin, mainly due to its resistance to the effect of heat and its insulating properties. However, its lack of toughness as a cured product hampers its application in printed circuit boards (PCBs). Herein, a branched structure via Michael addition was introduced to a BMI system to reinforce its toughness. Compared with a pure BMI sample, the flexural strength of the modified BMI was enhanced, and its maximum value of 189 MPa increased by 216%. The flexural modulus of the cured sample reached 5.2 GPa. Using a scanning electron microscope, the fracture surfaces of BMI samples and a transition from brittle fracture to ductile fracture were observed. Furthermore, both the dielectric constant and the dielectric loss of the cured resin decreased. The breakdown field strength was raised to 37.8 kV/mm and the volume resistivity was improved to varying degrees. Consequently, the resulting modified BMI resin has the potential for wide application in high-frequency and low-dielectric resin substrates, and the modified BMI resin with a structure including three different diamines can meet the needs of various applications.

14.
Ying Yong Sheng Tai Xue Bao ; 33(1): 219-228, 2022 Jan.
Artigo em Zh | MEDLINE | ID: mdl-35224944

RESUMO

To reveal the effects of plantations on soil microbial environment,the composition and diversity of soil fungi and bacterial communities in five restoration models (Robinia pseudoacacia, Populus hopeiensis, Pinus tabuliformis, Picea crassifolia, natural restoration) in the mountainous area of southern Ningxia were compared by using high-throughput sequencing technology. The correlation between soil physical-chemical properties and dominant microbial groups was analyzed. The results showed that: 1) Dominant fungi in different restoration models were Ascomycota, Basidiomycota, Mortierellomycota, and unclassified fungi, which accounted for 90% of total fungal community. The dominant soil bacteria were Actinobacteria, Proteobacteria, Acidobacteriota, Chloroflexi, and other bacteria, accounting for more than 80% of total bacterial community. 2) The diversity of soil fungi in P. tabuliformis forest was the highest, with Shannon index, and Simpson index being 3.72±0.37 and 0.07±0.04, respectively. The richness of fungi in naturally restored forest land was the highest, with Ace and Chao1 index of 708.19±137.25 and 706.26±125.34, respectively. The bacterial diversity and richness of species in P. tabuliformis forest land was the highest. The Shannon, Simpson, Ace and Chao1 indices were 6.57±0.04, 0.004±0.00, 3439.81±41.67, 3463.14±32.16, respectively. 3) The fungus with significant difference among restoration models were Solicoccozyma, Cladosporium, and Alternaria. Bacteria from Norank_f_67-14, Rubrobacter_f_Rubrobacteraceae, Sphingomonas_f_Sphingomonadaceae had significant difference among restoration models. 4) The RDA ordination of the dominant microbial flora and soil physical-chemical properties showed that soil bulk density (BD), carbon to nitrogen ratio (C/N), and pH were the major factors affecting the dominant fungal flora. BD, nitrogen to phosphorus ratio (N/P), total phosphorus (TP), and total carbon (TC) were the main factors affecting the dominant bacterial flora. In general, the difference of composition and diversity in the fungal community of different restoration models was higher than that of the bacterial community, indicating that the fungal communities were more sensitive to the changes of tree species and soil environment than bacterial communities. Our results could provide the theoretical foundation for vegetation restoration measures and the maintenance of ecosystem function stability in southern Ningxia.


Assuntos
Emigrantes e Imigrantes , Microbiota , China , Emigração e Imigração , Fungos , Humanos , Solo/química , Microbiologia do Solo
15.
Micromachines (Basel) ; 13(5)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35630161

RESUMO

Flexible wearable pressure sensors play a pivotal role in healthcare monitoring, disease prevention, and humanmachine interactions. However, their narrow sensing ranges, low detection sensitivities, slow responses, and complex preparation processes restrict their application in smart wearable devices. Herein, a capacitive pressure sensor with high sensitivity and flexibility that uses an ionic collagen fiber material as the dielectric layer is proposed. The sensor exhibits a high sensitivity (5.24 kPa-1), fast response time (40 ms), long-term stability, and excellent repeatability over 3000 cycles. Because the sensor is resizable, flexible, and has a simple preparation process, it can be flexibly attached to clothes and the human body for wearable monitoring. Furthermore, the practicality of the sensor is proven by attaching it to different measurement positions on the human body to monitor the activity signal.

16.
Nat Commun ; 13(1): 1317, 2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35273183

RESUMO

Electronic skins (e-skins) are devices that can respond to mechanical stimuli and enable robots to perceive their surroundings. A great challenge for existing e-skins is that they may easily fail under extreme mechanical conditions due to their multilayered architecture with mechanical mismatch and weak adhesion between the interlayers. Here we report a flexible pressure sensor with tough interfaces enabled by two strategies: quasi-homogeneous composition that ensures mechanical match of interlayers, and interlinked microconed interface that results in a high interfacial toughness of 390 J·m-2. The tough interface endows the sensor with exceptional signal stability determined by performing 100,000 cycles of rubbing, and fixing the sensor on a car tread and driving 2.6 km on an asphalt road. The topological interlinks can be further extended to soft robot-sensor integration, enabling a seamless interface between the sensor and robot for highly stable sensing performance during manipulation tasks under complicated mechanical conditions.

17.
Ying Yong Sheng Tai Xue Bao ; 32(3): 819-824, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33754546

RESUMO

We analyzed the relationship between carbon stable isotope characteristics of 131 Hippophae populations and environmental factors by measuring the foliar δ13C value in Hippophae. The results showed that the foliar δ13C values of Hippophae ranged from -24.65‰ to -29.11‰, with an average of -26.97‰. Hippophae species were C3 plants. For the foliar δ13C values, the coefficient variation at intraspecific level was higher than that at interspecific level, indicating that environmental factors should be main factors driving the variations of leaf δ13C. The δ13C values had no significant correlation with latitude and longitude, but were negatively correlated with altitude. The regression equation was δ13C(‰)=0.118VAP-0.007GST-0.000028RDA-20.721 (R2=0.212,P<0.0001). Water vapor pressure (VAP), growing season temperature (GST), and radiation (RDA) were the major factors affecting foliar δ13C values. Our results could provide a theoretical basis to understand the responses of Hippophae species to global climate change.


Assuntos
Carbono , Hippophae , Isótopos de Carbono , Folhas de Planta , Plantas
18.
Adv Mater ; 33(7): e2003464, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33346388

RESUMO

Over the past decade, a brand-new pressure- and tactile-sensing modality, known as iontronic sensing has emerged, utilizing the supercapacitive nature of the electrical double layer (EDL) that occurs at the electrolytic-electronic interface, leading to ultrahigh device sensitivity, high noise immunity, high resolution, high spatial definition, optical transparency, and responses to both static and dynamic stimuli, in addition to thin and flexible device architectures. Together, it offers unique combination of enabling features to tackle the grand challenges in pressure- and tactile-sensing applications, in particular, with recent interest and rapid progress in the development of robotic intelligence, electronic skin, wearable health as well as the internet-of-things, from both academic and industrial communities. A historical perspective of the iontronic sensing discovery, an overview of the fundamental working mechanism along with its device architectures, a survey of the unique material aspects and structural designs dedicated, and finally, a discussion of the newly enabled applications, technical challenges, and future outlooks are provided for this promising sensing modality with implementations. The state-of-the-art developments of the iontronic sensing technology in its first decade are summarized, potentially providing a technical roadmap for the next wave of innovations and breakthroughs in this field.


Assuntos
Pele Artificial , Técnicas Biossensoriais , Técnicas Eletroquímicas , Eletrólitos/química , Desenho de Equipamento , Humanos , Gotículas Lipídicas , Modelos Moleculares , Concentração Osmolar , Relação Estrutura-Atividade , Propriedades de Superfície , Tato , Dispositivos Eletrônicos Vestíveis
19.
Sci Bull (Beijing) ; 66(11): 1091-1100, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36654343

RESUMO

Electronic skins and flexible pressure sensors are important devices for advanced healthcare and intelligent robotics. Sensitivity is a key parameter of flexible pressure sensors. Whereas introducing surface microstructures in a capacitive-type sensor can significantly improve its sensitivity, the signal becomes nonlinear and the pressure response range gets much narrower, significantly limiting the applications of flexible pressure sensors. Here, we designed a pressure sensor that utilizes a nanoscale iontronic interface of an ionic gel layer and a micropillared electrode, for highly linear capacitance-to-pressure response and high sensitivity over a wide pressure range. The micropillars undergo three stages of deformation upon loading: initial contact (0-6 kPa) and structure buckling (6-12 kPa) that exhibit a low and nonlinear response, as well as a post-buckling stage that has a high signal linearity with high sensitivity (33.16 kPa-1) over a broad pressure range of 12-176 kPa. The high linearity lies in the subtle balance between the structure compression and mechanical matching of the two materials at the gel-electrode interface. Our sensor has been applied in pulse detection, plantar pressure mapping, and grasp task of an artificial limb. This work provides a physical insight in achieving linear response through the design of appropriate microstructures and selection of materials with suitable modulus in flexible pressure sensors, which are potentially useful in intelligent robots and health monitoring.

20.
ACS Nano ; 15(3): 5752-5761, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33683874

RESUMO

Interfacial solar evaporators (ISEs) for seawater desalination have garnered enormous attention in recent decades due to global water scarcity. Despite the progress in the energy conversion efficiency and production rate of ISE, the poor portability of large-area ISE during transportation as well as the clogging of water transport pathways by precipitated salts during operation remain grand challenges for its fielded applications. Here, we designed an ISE with high energy conversion efficiency and shape morphing capability by integrating carbon nanotube (CNT) fillers with a light-responsive shape memory polymer (SMP, cross-linked polycyclooctene (cPCO)). Utilizing the shape memory effect, our ISE can be folded to an origami with 1/9 of its original size to save space for transportation and allow for on-demand unfolding upon sunlight irradiation when deployed in service. In addition, the ISE is equipped with a real-time clogging monitoring function by measuring the capacitance of the electric double layer (EDL) formed at the evaporator/seawater nanointerface. Due to its good energy conversion efficiency, high portability, and clogging monitoring capability, we envisage our ISE as a promising selection in solar evaporation technologies.

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