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1.
ACS Appl Mater Interfaces ; 13(36): 43449-43457, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34472846

RESUMO

Composites based on a shape-memory polymer doped with conductive particles are considered as soft actuators for artificial muscles and robots. Low-voltage actuating is expected to reduce equipment requirement and safety hazards, which requires a highly conductive particle content but weakens the reversible deformation. The spatial distribution of the conductive particle is key to decreasing the actuating voltage and maintaining the reversible deformation. Herein, an approach of fabricating a low-voltage actuator that can perform various biomimetic locomotions by spraying and hot pressing is reported. Carbon nanotubes (CNTs) are enriched inside the surface layer of poly(ethylene-co-vinyl acetate) (EVA) to form a high-density conductive network without degradation of the reversible deformation. The bilayer CNT/EVA actuator exhibits a reversible transformation of more than 10% even with 100 cycles, which requires an applied voltage of just 15 V. Taking advantage of the reprogrammability of the CNT/EVA actuator and reversible shift between the different shapes, different biomimetic locomotions (sample actuator, gripper, and walking robot) are demonstrated without any additional mechanical components. A scheme combining the electrical properties and the shape-memory effect provides a versatile strategy to fabricate low-voltage-actuated polymeric actuators, providing inspiration in the development of electrical soft actuators and biomimetic devices.

2.
ACS Appl Mater Interfaces ; 12(47): 53230-53238, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33179903

RESUMO

Conductive textiles (CTs) are promising electromagnetic interference (EMI) shielding materials. Nevertheless, limited stretchability and poor reliability restrict their potential applications in stretchable electronic devices because of the rigid conductive networks. Herein, a highly stretchable and reliable CT is developed for effective EMI shielding by designing a deformable liquid-metal (LM) coating and polydimethylsiloxane (PDMS) protective layer. The resultant PDMS-LM/Textile exhibits an outstanding EMI shielding efficiency (EMI SE) of 72.6 dB at a thickness of only 0.35 mm while maintaining EMI SEs of 66.0 and 52.4 dB under strains of 30 and 50%, respectively. The corresponding EMI SEs hold 91.7 and 80.3% retention after 5000 stretching-releasing cycles, respectively. The superior and durable EMI SE should be ascribed to the perfect connectivity and good deformability of conductive LM networks. Moreover, the LM coating has a robust fastness to the textile substrate, without any obvious decrease in EMI SE after 10 min of ultrasonic treatment and 100 peeling cycles because of the protective effect of the PDMS layer. This work provides a novel route to developing highly stretchable CTs for advanced EMI shielding applications, especially in the field of highly stretchable electronic devices.

3.
ACS Appl Mater Interfaces ; 12(7): 8704-8712, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31971778

RESUMO

Excellent electromagnetic interference (EMI) shielding ability, light weight, and good heat resistance are highly required for practical applications of EMI shielding materials, such as in areas of aerospace, aircraft, and automobiles. Herein, a lightweight and robust carbon nanotube (CNT)/polyimide (PI) foam was developed for efficient and heat-resistant EMI shielding. Thanks to poly(vinyl pyrrolidone) (PVP) as a surfactant that not only promotes the uniform dispersion of CNTs to form perfect CNT conductive networks but also can be removed in situ during the polymerization process, the density of resultant CNT/PI foam is only 32.1 mg·cm-3, and the EMI shielding effectiveness (EMI SE) is up to 41.1 dB, which represents one of the highest EMI SE values compared to previously reported polymer-based foams. The CNT/PI foam also achieves the absorption coefficient (A) of up to 82.3%, which is very impressive in CNT/polymer foams at comparable EMI SE levels. The PI matrix endows the foam with excellent heat resistance. The as-prepared CNT/PI foam presents a higher EMI SE than 35 dB even after being subjected to the flame of an alcohol burner. Moreover, the compressive strength and compressive modulus are up to 240.9 and 323.9 kPa. These results indicate its certain application potential in the harsh requirement of aeronautics and aerospace industries as a highly efficient and lightweight EMI shielding material.

4.
Oxid Med Cell Longev ; 2020: 7101407, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33456673

RESUMO

Objective: Allergic asthma is a chronic inflammatory disease, which seriously affects the life quality of patients, especially children. Alanylglutamine is a nutritional supplement with potential protective and anti-inflammatory effects, but its function in allergic asthma remains elusive. In this study, we focused on the investigations of the roles and functional mechanism of Alanylglutamine in asthma. Methods: Ovalbumin (OVA) induction was utilized to establish a mouse asthma model. 16S rDNA sequencing was performed to compare the diversity of intestinal microorganisms under different treatments. Gas chromatography was utilized to screen the intestinal microbe-short-chain fatty acids in the stool. The lung tissue was extracted to determine signaling pathways, including AMPK, NF-κB, mTOR, STAT3, IKKß, TGF-ß, and IL-1ß through Western blot or RT-qPCR. Results: It was observed that Alanylglutamine reduced the cytokine in OVA-induced allergic asthma mice. H&E staining showed obvious pneumonia symptoms in the asthma group, while Alanylglutamine alleviated the inflammatory infiltration. Alanylglutamine reversed gut microbiota compositions in OVA-induced allergic asthma mice and enhanced the butyric acid level. The protective role of Alanylglutamine may be associated with the gut microbiota-butyric acid-GPR43 pathway in asthma mice. In contrast to the OVA group, Alanylglutamine activated the protein expression of P-AMPK/AMPK and inhibited the protein expression of P-mTOR/mTOR, P-P65/P65, P-STAT3/STAT3, P-IKKß/IKKß, TGF-ß, and IL-1ß, with similar effects from butyric acid. Conclusion: The results indicated that Alanylglutamine might be beneficial for asthma, and its effect was achieved through the regulation on microbiota and the derived metabolites. The therapeutic effects might be associated with AMPK, NF-κB, mTOR, and STAT3 signaling pathways. These findings will help identify effective therapeutic direction to alleviate allergic inflammation of the lungs and airways.


Assuntos
Asma/tratamento farmacológico , Asma/microbiologia , Dipeptídeos/uso terapêutico , Microbioma Gastrointestinal , Metaboloma , Aminoácidos/análise , Animais , Antibacterianos/farmacologia , Asma/complicações , Biodiversidade , Ácido Butírico/farmacologia , Citocinas/metabolismo , Dipeptídeos/farmacologia , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Hipersensibilidade/complicações , Hipersensibilidade/microbiologia , Inflamação/patologia , Masculino , Metaboloma/efeitos dos fármacos , Camundongos Endogâmicos BALB C , NF-kappa B/metabolismo , Ovalbumina , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais
5.
ACS Appl Mater Interfaces ; 11(40): 37094-37102, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31512856

RESUMO

Flexible strain sensors based on elastomeric conductive polymer composites (ECPCs) play an important role in wearable sensing electronics. However, the achievement of good conjunction between broad detection range and high sensitivity is still challenging. Herein, a highly stretchable and sensitive strain sensor was developed with the formation of porous segregated conductive network in the carbon nanotube/thermoplastic polyurethane composite via a facile and nontoxic compression-molding plus salt-leaching method. The strain sensor with porous segregated conductive network exhibited perfect combination of ultrawide sensing range (800% strain), large sensitivity (gauge factor of 356.4), short response time (180 ms) and recovery time (180 ms), as well as superior stability and durability. The integrated porous structure intensifies the deformation of segregated conductive network when tension strain is applied, which benefits enhancement of the sensitivity. Our sensor could monitor not only subtle oscillation and physiological signals but also energetic human motions efficiently, revealing promising potential applications in wearable motion monitoring systems. This work provides a unique and effective strategy for realizing ECPCs based strain sensors with excellent comprehensive sensing performances.

6.
ACS Appl Mater Interfaces ; 11(1): 1680-1688, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30520621

RESUMO

Superhydrophobic electromagnetic interference (EMI) shielding textile (EMIST) is of great significance to the safety and long-term service of all-weather outdoor equipment. However, it is still challenging to achieve long-term durability and stability under external mechanical deformations or other harsh service conditions. Herein, by designing and implementing silver nanowire (AgNW) networks and a superhydrophobic coating onto a commercial textile, we demonstrate a highly robust superhydrophobic EMIST. The resultant EMIST shows a synergy of high water contact angle (160.8°), low sliding angle (2.9°), and superior EMI shielding effectiveness (51.5 dB). Remarkably, the EMIST still maintains its superhydrophobic feature and high EMI shielding level (42.6 dB) even after 5000 stretching-releasing cycles. Moreover, the EMIST exhibits strong resistance to ultrasonic treatment up to 60 min, peeling test up to 100 cycles, strong acidic/alkaline solutions, and different organic solvents, indicating its outstanding mechanical robustness and chemical durability. These attractive features of the EMIST are mainly a result of the joint action of AgNWs, carbon nanotubes, polytetrafluoroethylene nanoparticles, and fluoroacrylic polymer. This work offers a promising approach for the design of future durable, superhydrophobic EMISTs, which are capable of remaining fully functional against long-time exposure to extreme conditions, for example, wet and corrosive environments.

7.
J Endourol ; 29(8): 855-63, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25746718

RESUMO

PURPOSE: To compare the clinical efficacy and safety of selective vs hilar clamping during minimally invasive partial nephrectomy (PN). METHODS: Studies comparing the effect and safety of selective versus hilar clamping during PN were identified by a systematic search using MEDLINE and EMBASE from January 2000 to November 2014. Quality of the selected studies was assessed according to the Newcastle-Ottawa Scale (NOS). RESULTS: A total of seven retrospective studies were included. No significant differences were observed between the two groups in age, body mass index, tumor size, pre-estimated glomerular filtration rate (eGFR), operative time, and length of stay. The selective clamping group had greater estimated blood loss (P<0.01) but similar blood transfusion rate (P=0.78) compared with the hilar clamping group. There were no significant differences between the two groups in terms of urinary leaks, overall complication rate, and positive margin rate. Patients who underwent selective clamping had a lower change in eGFR (mean difference [MD]: 13.95; 95% CI 8.85 to 19.05; P<0.01) and a lower percent change in eGFR (MD: 18.51; 95% CI 14.18 to 22.84; P<0.01) at 1 week. Combined results from two studies showed a trend toward a lower percent change in eGFR at 3 months (MD: 5.47; 95% CI -0.28 to 11.22; P=0.06). At 6 months, two studies showed no significant differences in percent change of renal function between the two groups (MD: 16.85; 95% CI -10.47 to 44.16; P=0.23). CONCLUSIONS: Although selective clamping resulted in greater estimated blood loss, it provided comparable perioperative safety and superior short-term renal function preservation. The advantage of selective clamping in preservation of intermediate-term renal function remains to be evaluated in the future, however. There is a need for properly designed studies to confirm our founding.


Assuntos
Neoplasias Renais/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Nefrectomia/métodos , Perda Sanguínea Cirúrgica , Constrição , Taxa de Filtração Glomerular , Humanos , Duração da Cirurgia , Estudos Retrospectivos
8.
Basic Clin Pharmacol Toxicol ; 113(2): 87-91, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23521814

RESUMO

It has been shown that activation of spinal RhoA/Rho kinase (ROCK) signalling pathway facilitates nociception in neuropathic and inflammatory pain, but its effects on bone cancer pain (BCP) have not previously been studied. This study was designed to examine the potential role of the spinal RhoA/ROCK signalling pathway in the development of BCP. A model for bone cancer was induced by injecting Walker 256 cells into the tibia of rats. On days 6, 9 and 15 after inoculation, the expression of spinal RhoA and ROCK2 protein levels was higher in the Walker 256 cells injected rats compared to the sham rats. On day 9, intrathecal injection of C3 exoenzyme (a RhoA inhibitor, 10 pg) significantly attenuated BCP behaviour as well as up-regulation of spinal RhoA and ROCK2 protein levels. These effects were completely abolished by intrathecal pretreatment with U-46619 (a RhoA agonist, 1.5 pg). These results suggest that the spinal RhoA/ROCK signalling pathway may be involved in the development of BCP. The findings of this study may lead to novel therapeutic strategies for prevention and/or treatment of BCP.


Assuntos
Neoplasias Ósseas/genética , Dor/genética , Transdução de Sinais , Quinases Associadas a rho/genética , Proteína rhoA de Ligação ao GTP/genética , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Animais , Neoplasias Ósseas/complicações , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Inibidores Enzimáticos/farmacologia , Feminino , Injeções Espinhais , Dor/complicações , Dor/tratamento farmacológico , Dor/patologia , Ratos , Ratos Sprague-Dawley , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Regulação para Cima , Quinases Associadas a rho/antagonistas & inibidores , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/metabolismo
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