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1.
Artigo em Inglês | MEDLINE | ID: mdl-38587364

RESUMO

Venous blood collection testing is one of the most commonly used medical diagnostic methods. Compared with conventional venous blood collection, robotic collection can reduce needle-stick injuries, medical staff workload, and infection risk; allow doctor-patient isolation; and improve collection reliability. Existing venous blood collection robots use rigid puncture needles, which can easily puncture the lower wall of blood vessels, causing vessel damage and collection failure. This paper proposes a bionic blood collection strategy based on a composite puncture needle that mimics the structure and function of mosquito mouthparts. A bionic composite puncture needle insertion system with puncture-force sensing was designed, and venipuncture forces were simulated and mathematically modelled. A prototype insertion system was built and used in an experiment, which demonstrated effective composite puncture blood collection and explored the factors influencing puncture force. Puncture force decreases with increased puncture speed and angle and with a decreased needle diameter. This provides a basis for optimising the parameters of blood collection robots.

2.
Bioinspir Biomim ; 19(3)2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38452382

RESUMO

The exploration of the planet Mars still is a top priority in planetary science. The Mars surface is extensively covered with soil-like material. Current wheeled rovers on Mars have been occasionally experiencing immobilization instances in unexpectedly weak terrains. The development of Mars rovers adaptable to these terrains is instrumental in improving exploration efficiency. Inspired by locomotion of the desert lizard, this paper illustrates a biomimetic quadruped robot with structures of flexible active spine and toes. By accounting for spine lateral flexion and its coordination with four leg movements, three gaits of tripod, trot and turning are designed. The motions corresponding to the three gaits are conceptually and numerically analyzed. On the granular terrains analog to Martian surface, the gasping forces by the active toes are estimated. Then traversing tests for the robot to move on Martian soil surface analog with the three gaits were investigated. Moreover, the traversing characteristics for Martian rocky and slope surface analog are analyzed. Results show that the robot can traverse Martian soil surface analog with maximum forward speed 28.13 m s-1turning speed 1.94° s-1and obstacle height 74.85 mm. The maximum angle for climbing Martian soil slope analog is 28°, corresponding slippery rate 76.8%. It is predicted that this robot can adapt to Martian granular rough terrain with gentle slopes.


Assuntos
Marte , Robótica , Meio Ambiente Extraterreno , Biomimética , Solo
3.
Nanomicro Lett ; 16(1): 151, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38466453

RESUMO

Despite notable progress in thermoelectric (TE) materials and devices, developing TE aerogels with high-temperature resistance, superior TE performance and excellent elasticity to enable self-powered high-temperature monitoring/warning in industrial and wearable applications remains a great challenge. Herein, a highly elastic, flame-retardant and high-temperature-resistant TE aerogel, made of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/single-walled carbon nanotube (PEDOT:PSS/SWCNT) composites, has been fabricated, displaying attractive compression-induced power factor enhancement. The as-fabricated sensors with the aerogel can achieve accurately pressure stimuli detection and wide temperature range monitoring. Subsequently, a flexible TE generator is assembled, consisting of 25 aerogels connected in series, capable of delivering a maximum output power of 400 µW when subjected to a temperature difference of 300 K. This demonstrates its outstanding high-temperature heat harvesting capability and promising application prospects for real-time temperature monitoring on industrial high-temperature pipelines. Moreover, the designed self-powered wearable sensing glove can realize precise wide-range temperature detection, high-temperature warning and accurate recognition of human hand gestures. The aerogel-based intelligent wearable sensing system developed for firefighters demonstrates the desired self-powered and highly sensitive high-temperature fire warning capability. Benefitting from these desirable properties, the elastic and high-temperature-resistant aerogels present various promising applications including self-powered high-temperature monitoring, industrial overheat warning, waste heat energy recycling and even wearable healthcare.

4.
Mater Horiz ; 11(7): 1679-1688, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38305351

RESUMO

Due to the prevalence of electronic devices, intelligent sensors have attracted much interest for the detecting and providing alarms with respect to indoor electrical safety. Nonetheless, how to effectively identify various indoor electrical safety hazards remains a challenge. In this study, we fabricated single-walled carbon nanotube/poly(3-hexylthiophene-2,5-diyl) (SWCNT/P3HT) composites with exceptional bifunctional thermoelectric and photoelectric responses. Through synergy of the thermo-/photoelectric effects, the composites yielded greatly enhanced output voltages compared with the use of thermoelectric effects alone. Interestingly, modes of heat transfer can be effectively distinguished using the nominal Seebeck coefficients. Based on the remarkable output voltages and deviations in the nominal Seebeck coefficients, we developed indoor intelligent sensors capable of effectively identifying and monitoring diverse indoor electrical conditions, including electrical overheating, fire, and air conditioning flow. This pioneering investigation proposes a novel avenue for designing intelligent sensors that can recognize heat transfer modes and hence effectively monitor indoor electrical safety hazards.

5.
J Clin Rheumatol ; 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38389131

RESUMO

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) is a life-threatening opportunistic infection in immunocompromised children with systemic lupus erythematosus (SLE). Prophylaxis against PJP in high-risk children is crucial, but the risk factors for PJP in children with SLE are not adequately characterized. This study sought to identify the risk factors for PJP in long-term glucocorticoid-treated pediatric SLE patients. METHODS: This study encompassed 71 treatment episodes involving 64 children with prolonged (≥4 weeks) high-dose (≥20 mg/d prednisone) steroid regimens. Fourteen treatment episodes involved the PJP, whereas others did not. Risk factors for PJP were assessed through Cox regression. The predictive value of these factors was evaluated using receiver operating characteristic curves. The incidence of PJP in different risk groups was compared using the Kaplan-Meier method. RESULTS: The creatinine (hazard ratio, 1.009; 95% confidence interval [CI], 1.001-1.017; p = 0.021) and the lowest lymphocyte count (hazard ratio, 0.007; 95% CI, 0.000-0.373; p = 0.014) were independent risk factors for PJP in children with SLE. The receiver operating characteristic curve showed that using creatinine greater than 72.5 µmol/L and the lowest lymphocyte count less than 0.6 × 109/L as risk predictors for PJP resulted in an area under the curve value of 0.934 (95% CI, 0.870-0.997; p < 0.001). The study revealed a significant increase in PJP prevalence (p < 0.001) in children with elevated creatinine levels and low lymphocyte count. CONCLUSIONS: Elevated levels of creatinine and decreased lymphocyte count are identified as distinct risk factors for PJP in children with SLE who receive prolonged high-dose steroid therapy.

6.
Urol Int ; 108(2): 118-127, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38185112

RESUMO

INTRODUCTION: Overactive bladder symptoms (OABSs) affect patients' quality of life (QOL) worldwide. This pooled analysis compared the efficacy and safety of mirabegron add-on tamsulosin with those of tamsulosin add-on placebo in OABS treatment. METHODS: PubMed, Embase, MEDLINE, and the Cochrane Controlled Trial Register databases were searched for randomized controlled trials (RCTs) examining the efficacy of mirabegron add-on therapy to tamsulosin in the treatment of OABS. Moreover, references from the selected studies were screened. Review Manager 5.4 was used to analyze data. RESULTS: Four RCTs involving 1,397 patients with OABS were selected. Of the total, 697 patients receiving mirabegron add-on tamsulosin constituted the experimental group, and 700 patients receiving tamsulosin add-on placebo constituted the control group. The efficacy endpoints were as follows: mean number of micturition per day (mean difference [MD] = -0.26, 95% confidence interval [CI] = -0.41 to -0.10, p = 0.0001), urgency episodes per day (MD = -0.67, 95% CI = -1.02 to -0.32, p = 0.0002), urgency urinary incontinence (UUI) episodes per day (MD = -0.42, 95% CI = -0.66 to -0.19, p = 0.0005), mean volume voided/micturition (MD = 10.84, 95% CI = 4.97-16.71, p = 0.0003), total International Prostate Symptom Score (IPSS) (MD = -2.01, 95% CI = -4.02 to -0.01, p = 0.05), and IPSS QOL index (MD = -0.65, 95% CI = -0.94 to -0.35, p < 0.0001). Mirabegron therapy, an add-on therapy to tamsulosin, was effective in treating patients with OABS. Moreover, mirabegron might reduce the total IPSS (MD = -2.01, 95% CI = -4.02 to -0.01, p = 0.05). The safety endpoint, treatment-emergent adverse events (odds ratio = 0.94, 95% CI = 0.78-1.13, p = 0.49), suggested that although mirabegron was well-tolerated, it possibly increased the post-void residual urine volume (MD = 10.28, 95% CI = 1.82-18.75, p = 0.02). CONCLUSION: Combination therapy using mirabegron and tamsulosin may be effective in treating patients with non-neurogenic OABS in terms of UUI episodes, total IPSS, and IPSS QOL index. However, its effectiveness must be verified by analyzing additional factors for OABS through further RCTs.


Assuntos
Tiazóis , Bexiga Urinária Hiperativa , Incontinência Urinária , Masculino , Humanos , Tansulosina/uso terapêutico , Bexiga Urinária Hiperativa/tratamento farmacológico , Bexiga Urinária Hiperativa/diagnóstico , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto , Acetanilidas , Método Duplo-Cego
7.
Carbohydr Res ; 535: 109011, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38150753

RESUMO

In this study, a pure Grifola frondosa polysaccharide (GFP-1) was extracted and purified from Grifola frondosa. By HPLC, GC-MS, FT-IR, and NMR analysis, GFP-1 was determined to be a starch-like polysaccharide with an average molecular weight of 3370 kDa. It included three monosaccharides, i.e., glucose, galactose, and mannose. The backbone of GFP-1 consisted of →4)-α-Glcp-(1→ and →4,6)-α-Glcp-(1 â†’ . The side branches were composed of →6)-α-Galp-(1→, α-Glcp-(1→, and a small amount of α-Manp-(1 â†’ . By using a cyclophosphamide (CTX)-induced immunosuppressed mice model, we evaluated the immunomodulatory activity of GFP-1. The results showed that GFP-1 increased the thymic and spleen indices, promoted the level of IgG and IgA in serum, and activated the mitogen-activated protein kinase (MAPK) pathway in CTX-induced mice. Also, GFP-1 significantly promoted the mRNA expression of intestinal barrier factors and protected intestinal structural integrity in immunosuppressed mice. In conclusion, the data presented here suggested that GFP-1 might be a potential immune-enhancing supplement.


Assuntos
Grifola , Amido , Animais , Camundongos , Grifola/química , Espectroscopia de Infravermelho com Transformada de Fourier , Polissacarídeos/farmacologia , Polissacarídeos/química , Ciclofosfamida/efeitos adversos , Terapia de Imunossupressão
8.
ACS Nano ; 17(22): 22478-22487, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37934024

RESUMO

The growing global demand for sustainable and cost-effective energy storage solutions has driven the rapid development of zinc batteries. Despite significant progress in recent years, enhancing the energy density of zinc batteries remains a crucial research focus. One prevalent strategy involves the development of high-capacity and/or high-voltage cathode materials. CuS, a commonly used electrode material, exhibits a two-electron transfer mechanism; however, the reduced sulfion lacks electrochemical activity and thereby limits its discharge capacity and redox potential. In this study, we activate a CuS cathode to form a high-valence Cu2+&S compound using a deep-eutectic-solvent (DES)-based electrolyte. The presence of Cl- in the DES-based electrolyte is crucial to the reversibility of the redox chemistry, and the liquid-phase-involved electrochemical process facilitates redox kinetics. A four-electron transfer pathway involving five reaction steps is identified for the CuS electrode, which unleashes the full electrochemical activity of the S element. Consequently, the full cell delivers a large discharge capacity of ∼800 mAh g-1 at 0.2 A g-1 and yields a high discharge plateau starting at 1.58 V, contributing to energy densities of up to 650 Wh kg-1 (based on CuS). This work offers a promising approach to developing high-energy zinc batteries.

9.
Nat Commun ; 14(1): 6738, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37875485

RESUMO

Aqueous copper-based batteries have many favourable properties and have thus attracted considerable attention, but their application is limited by their low operating voltage originating from the high potential of copper negative electrode (0.34 V vs. standard hydrogen electrode). Herein, we propose a coordination strategy for reducing the intrinsic negative electrode redox potential in aqueous copper-based batteries and thus improving their operating voltage. This is achieved by establishing an appropriate coordination environment through the electrolyte tailoring via Cl- ions. When coordinated with chlorine, the intermediate Cu+ ions in aqueous electrolytes are successfully stabilized and the electrochemical process is decoupled into two separate redox reactions involving Cu2+/Cu+ and Cu+/Cu0; Cu+/Cu0 results in a redox potential approximately 0.3 V lower than that for Cu2+/Cu0. Compared to the coordination with water, the coordination with chlorine also results in higher copper utilization, more rapid redox kinetics, and superior cycle stability. An aqueous copper-chlorine battery, harnessing Cl-/Cl0 redox reaction at the positive electrode, is discovered to have a high discharge voltage of 1.3 V, and retains 77.4% of initial capacity after 10,000 cycles. This work may open up an avenue to boosting the voltage and energy of aqueous copper batteries.

10.
Small ; : e2306211, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37875779

RESUMO

The stability of aqueous Zn-ion batteries (AZIBs) is detrimentally influenced by the formation of Zn dendrites and the occurrence of parasitic side reactions at the Zn metal anode (ZMA)-electrolyte interface. The strategic manipulation of the preferential crystal orientation during Zn2+ plating serves as an essential approach to mitigate this issue. Here, Zn aspartate (Zn-Asp), an electrolyte additive for AZIBs, is introduced not only to optimize the solvation structure of Zn2+ , but also to crucially promote preferential Zn2+ plating on the (002) crystal plane of ZMA. As a result, both side reactions and Zn dendrites are effectively inhibited, ensuring an anode surface free of both dendrites and by-products. The implementation of Zn-Asp leads to significant enhancements in both Zn||Zn symmetric and Zn||Ti batteries, which demonstrate robust cyclability of over 3200 h and high Coulombic efficiency of 99.29%, respectively. Additionally, the Zn||NaV3 O8 ·1.5H2 O full battery exhibits remarkable rate capability, realizing a high capacity of 240.77 mA h g-1 at 5 A g-1 , and retains 92.7% of its initial capacity after 1000 cycles. This research underscores the vital role of electrolyte additives in regulating the preferential crystal orientation of ZMA, thereby contributing to the development of high-performing AZIBs.

11.
Sci Bull (Beijing) ; 68(24): 3261-3277, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-37722927

RESUMO

Historically, fire disasters have killed numerous human lives, and caused tremendous property loss. Fire warning systems play a vital role in predicting fire risks, and are strongly desired to effectively prevent the disaster occurrence and significantly reduce the loss. Among the developed fire warning systems, thermoelectrics (TEs) and thermocells (TECs)-based fire warning materials are extremely important and indispensable in future research, owing to their unique capability of direct conversion between heat and electricity. Here, we present this review of the recent progress of TEs and TECs in fire warning field. Firstly, a brief introduction of existing fire warning systems is provided, including the mechanisms and features of various types. Then, the mechanisms of electronic TE (eTE), ionic TE (iTE) and TEC are elucidated. Next, the basic principles for the material preparation and device fabrication are discussed in their dimension sequence. Subsequently, some important advances or examples of TE fire warnings are highlighted in details. Finally, the challenges and prospects are outlooked.

12.
Nanomicro Lett ; 15(1): 196, 2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37566154

RESUMO

The evolution of wearable technology has prompted the need for adaptive, self-healable, and energy-autonomous energy devices. This study innovatively addresses this challenge by introducing an MXene-boosted hydrogel electrolyte, which expedites the assembly process of flexible thermocell (TEC) arrays and thus circumvents the complicated fabrication of typical wearable electronics. Our findings underscore the hydrogel electrolyte's superior thermoelectrochemical performance under substantial deformations and repeated self-healing cycles. The resulting hydrogel-based TEC yields a maximum power output of 1032.1 nW under the ΔT of 20 K when being stretched to 500% for 1000 cycles, corresponding to 80% of its initial state; meanwhile, it sustains 1179.1 nW under the ΔT of 20 K even after 60 cut-healing cycles, approximately 92% of its initial state. The as-assembled TEC array exhibits device-level self-healing capability and high adaptability to human body. It is readily applied for touch-based encrypted communication where distinct voltage signals can be converted into alphabet letters; it is also employed as a self-powered sensor to in-situ monitor a variety of body motions for complex human actions. The swift assembly approach, combined with the versatile functionality of the TEC device, paves the way for future advancements in wearable electronics targeting at fitness monitoring and human-machine interfaces.

13.
Adv Mater ; 35(40): e2304209, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37401825

RESUMO

Ammonium-ion batteries, leveraging non-metallic ammonium ions, have arisen as a promising electrochemical energy storage system; however, their advancement has been hindered by the scarcity of high-performance ammonium-ion storage materials. In this study, an electrochemical phase transformation approach is proposed for the in situ synthesis of layered VOPO4 ·2H2 O (E-VOPO) with predominant growth on the (200) plane, corresponding to the tetragonal channels on the (001) layers. The findings reveal that these tetragonal in-layer channels not only furnish NH4 + storage sites but also enhance transfer kinetics by providing rapid cross-layer migration pathways. This crucial aspect has been largely overlooked in previous studies. The E-VOPO electrode exhibits exceptional ammonium-ion storage performance, including significantly increased specific capacity, enhanced rate capability, and robust cycling stability. The resulting full cell can be stably operated for 12 500 charge-discharge cycles at 2 A g-1 for over 70 days. The proposed approach offers a new strategy for meticulously engineering electrode materials with facilitated ion storage and migration, thereby paving the way for developing more efficient and sustainable energy storage systems.

14.
J Gene Med ; 25(11): e3549, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37271571

RESUMO

BACKGROUND: Kidney renal clear cell carcinoma (KIRC) is a prevalent type of urological malignancy. The present study aimed to predict biomarkers for KIRC. METHODS: We collected transcriptomic and clinical information for KIRC from The Cancer Genome Atlas and GSE22541 cohorts. RESULTS: Unsupervised clustering of 35 epithelial-mesenchymal transformation (EMT)-related differentially expressed gene profiles divided samples into two clusters with distinct immune characteristics. Six genes (IL20RB, DDC, ANKRD36BP2, F2RL1, TEK, and AMN) were found to construct a prognostic risk model using multivariate Cox regression analysis. Kaplan-Meier analysis suggested the better prognosis of the KIRC patients in the low-risk group than that in the high-risk group. Immune infiltration analyses was conducted using xCell and single-sample gene set enrichment analysis, indicating that the risk score was associated with the immune microenvironment of the KIRC. Prognostic marker gene-targeted medications with high drug sensitivity were predicted in KIRC patients. CONCLUSIONS: In summary, the present study identified IL20RB, DDC, ANKRD36BP2, F2RL1, TEK, and AMN as prognostic biomarkers, providing insight into immunotherapy and gene-targeted drugs of KIRC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Prognóstico , Transição Epitelial-Mesenquimal/genética , Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Biomarcadores , Rim , Microambiente Tumoral
15.
Mol Genet Genomic Med ; 11(7): e2163, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37248651

RESUMO

BACKGROUND: Kidney disease of children markedly affects their health and development. Limited clinical data of early-stage kidney disease render a tremendous challenge for the accurate diagnosis. Trio whole-exome sequencing (Trio-WES) is emerging as a first-line diagnostic strategy in pediatric kidney disease, and shows important implications for the precision medicine strategies of children with kidney disease. METHODS: Trio-WES was performed in 133 Chinese children with kidney disease and their parents. The results for casual variants in genes known to cause kidney disease were analyzed. We further assessed the genetic diagnostic yield and the clinical implications of genetic testing. RESULTS: An overall diagnostic yield of 52.63% (70/133) was found, and the diagnostic rates ranged from 44.74% to 59.62% in different clinical phenotypes. The diagnostic yield of the three groups of simple proteinuria, renal insufficiency, and "other" was 50%, 50%, and 54.55%, respectively. Eight-seven diagnostic variants were identified in 70 probands with variants spanning 30 genes. The top 7 genes with diagnostic variants were COL4A5 (23, 26.44%), COL4A4 (13, 14.94%), ADCK4 (7, 8.05%), CLCN5 (3, 3.45%), ACE (3, 3.45%), PKD1 (3, 3.45%), and SLC12A3 (3, 3.45%), accounting for 63.22% of all variations in the cohort. CONCLUSIONS: The retrospective cohort study summarized the clinical utility of genetic testing in 133 probands, and expanded the phenotypic and genetic profiles of kidney disease in children. Trio-WES is an efficient diagnostic tool for children with kidney disease, which facilitates the clinical diagnosis and treatment. Our findings have important implications for the precise diagnosis of childhood nephropathy and may provide clinical guideline for disease management.


Assuntos
Testes Genéticos , Nefropatias , Humanos , Estudos Retrospectivos , Sequenciamento do Exoma , Testes Genéticos/métodos , Fenótipo , Membro 3 da Família 12 de Carreador de Soluto
16.
Research (Wash D C) ; 6: 0144, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37228637

RESUMO

Insects that can perform flapping-wing flight, climb on a wall, and switch smoothly between the 2 locomotion regimes provide us with excellent biomimetic models. However, very few biomimetic robots can perform complex locomotion tasks that combine the 2 abilities of climbing and flying. Here, we describe an aerial-wall amphibious robot that is self-contained for flying and climbing, and that can seamlessly move between the air and wall. It adopts a flapping/rotor hybrid power layout, which realizes not only efficient and controllable flight in the air but also attachment to, and climbing on, the vertical wall through a synergistic combination of the aerodynamic negative pressure adsorption of the rotor power and a climbing mechanism with bionic adhesion performance. On the basis of the attachment mechanism of insect foot pads, the prepared biomimetic adhesive materials of the robot can be applied to various types of wall surfaces to achieve stable climbing. The longitudinal axis layout design of the rotor dynamics and control strategy realize a unique cross-domain movement during the flying-climbing transition, which has important implications in understanding the takeoff and landing of insects. Moreover, it enables the robot to cross the air-wall boundary in 0.4 s (landing), and cross the wall-air boundary in 0.7 s (taking off). The aerial-wall amphibious robot expands the working space of traditional flying and climbing robots, which can pave the way for future robots that can perform autonomous visual monitoring, human search and rescue, and tracking tasks in complex air-wall environments.

17.
Small Methods ; 7(8): e2300190, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37096881

RESUMO

Low-grade heat represents a significant form of energy loss; thermocells (TECs) utilizing the thermogalvanic effect can convert thermal energy into electricity without generating vibrations, noise, or waste emissions, making them a promising energy conversion technology for efficiently harvesting low-grade heat. Despite recent advancements, the reliance on high-cost platinum electrodes in TECs has considerably hindered their widespread adoption. Developing cost-effective electrodes that maintain the same thermoelectrochemical performance is crucial for the successful application of TECs. In this review article, the exploration of MXene materials as TEC electrodes is discussed first, emphasizing the immense potential of the MXene family for low-grade heat harvesting applications. Next, recent research on carbon-based electrodes is summarized, and morphological and structural optimizations are comprehensively discussed aiming at enhancing the thermoelectrochemical performance of TECs. In the concluding section, the challenges are outlined and future perspectives are offered, which provide valuable insights into the ongoing development of high-performance TEC electrodes using MXene and carbon-based materials.

18.
Int J Biol Macromol ; 241: 124386, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37054858

RESUMO

In this study, two homogeneous polysaccharides (APS-A1 and APS-B1) were isolated from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Their chemical structures were characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-A1 (2.62 × 106 Da) was a 1,4-α-D-Glcp backbone with a 1,4,6-α-D-Glcp branch every ten residues. APS-B1 (4.95 × 106 Da) was a heteropolysaccharide composed of glucose, galactose, and arabinose (75.24:17.27:19.35). Its backbone consisted of 1,4-α-D-Glcp, 1,4,6-α-D-Glcp, 1,5-α-L-Araf and the sidechains composed of 1,6-α-D-Galp and T-α/ß-Glcp. Bioactivity assays showed that APS-A1 and APS-B1 had potential anti-inflammatory activity. They could inhibit the production of inflammatory factors (TNF-α, IL-6, and MCP-1) in LPS-stimulated RAW264.7 macrophages via NF-κB and MAPK (ERK, JNK) pathways. These results suggested that the two polysaccharides could be potential anti-inflammatory supplements.


Assuntos
Astragalus propinquus , Polissacarídeos , Astragalus propinquus/química , Polissacarídeos/química , Monossacarídeos/química , Macrófagos , Anti-Inflamatórios/química
19.
Soft Robot ; 10(4): 713-723, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36779989

RESUMO

The majority of sprawling-posture quadrupedal vertebrates, such as geckos and lizards, adopt a cyclical lateral swing pattern of their trunk that is coordinated with limb movements to provide extraordinary flexibility and mobility. Inspired by the gecko's locomotory gait and posture, a gecko-like robot with a flexible spine driven by shape memory alloy (SMA) springs was proposed in this work. The static parameters of the SMA spring were experimentally measured, and the flexible spine driven by SMA springs can be deflected bidirectionally. A kinematic model of the spine mechanism was established, and the mathematical relationship between the thermodynamic behavior of the SMA springs and spinal deflection was systematically analyzed. When a gecko trots with a lateral swing pattern of its trunk, the body and the spine show a standing wave shape and a single-peak C-type curve, respectively. The lateral spine deflection and trotting gait were combined in a collaborative model of a flexible spine and limbs to describe in detail the specific relationships between leg joint variables and spine deflection angle. Planar motion tests of a prototype robot were also conducted by using four high-speed cameras to record the trajectory of each point of the body, which verified the proposed model. From the acquired results, it was demonstrated that, compared with a rigid body, a robot with a flexible spine has a longer stride length, higher speed, and a greatly reduced turning radius.


Assuntos
Lagartos , Robótica , Animais , Ligas de Memória da Forma , Locomoção , Coluna Vertebral
20.
Biomimetics (Basel) ; 8(1)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36810375

RESUMO

Exploring Mars is beneficial to increasing our knowledge, understanding the possibility of ancient microbial life there, and discovering new resources beyond the Earth to prepare for future human missions to Mars. To assist ambitious uncrewed missions to Mars, specific types of planetary rovers have been developed for performing tasks on Mars' surface. Due to the fact that the surface is composed of granular soils and rocks of various sizes, contemporary rovers can have difficulties in moving on soft soils and climbing over rocks. To overcome such difficulties, this research develops a quadruped creeping robot inspired by the locomotion characteristics of the desert lizard. This biomimetic robot features a flexible spine, which allows swinging movements during locomotion. The leg structure utilizes a four-linkage mechanism, which ensures a steady lifting motion. The foot consists of an active ankle and a round pad with four flexible toes that are effective in grasping soils and rocks. To determine robot motions, kinematic models relating to foot, leg, and spine are established. Moreover, the coordinated motions between the trunk spine and leg are numerically verified. In addition, the mobility on granular soils and rocky surface are experimentally demonstrated, which can imply that this biomimetic robot is suitable for Mars surface terrains.

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