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1.
Chem Commun (Camb) ; 55(91): 13737-13740, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31661086

RESUMO

A highly transparent and stretchable electrode based on a Au nanomesh, electrodeposited with a thin layer of MnO2 with a transparency of 84.7% is introduced. The as-prepared transparent, stretchable, and imperceptible supercapacitor (TSPS) exhibits a specific capacitance of 0.53 mF cm-2 and excellent bending stability, together with high stretchability (up to 160% strain).

2.
ACS Appl Mater Interfaces ; 11(10): 10373-10379, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30781948

RESUMO

Skin-like electronics require materials that are conducting, soft, intrinsically stretchable, and highly robust. However, electronic devices often consist of multilayers, and the failure of the electronic devices mostly starts from the debonding of the layers because of poor interfacial adhesion and large mechanical mismatch. Herein, we introduce a fully organic and intrinsically stretchable electrode that achieves high robustness by grafting the substrate to improve the interfacial adhesion and by introducing deep folds and wrinkles to improve the stretchability. The electrode exhibits a sheet resistance of 90 Ω/□ and negligible change in resistance at strains of up to 100% and shows no fatigue over 10 000 cyclic stretches to 100% strain. An iontronic skin with the electrodes is capable of detecting tiny objects exemplified by walking ants or fruit flies weighing less than 1 mg, and the device can be cyclically stretched to 30% for 1000 times without fatigue. The high robustness and stretchability of the fully organic iontronic skin lie in the wrinkle structures, small mechanical mismatch, and high interfacial strength among different layers. This work offers a general way to fabricate highly stretchable and robust devices.

3.
ACS Nano ; 13(2): 1097-1106, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30633498

RESUMO

Polymers with superior mechanical properties are desirable in many applications. In this work, polyethylene (PE) films reinforced with exfoliated thermally reduced graphene oxide (TrGO) fabricated using a roll-to-roll hot-drawing process are shown to have outstanding mechanical properties. The specific ultimate tensile strength and Young's modulus of PE/TrGO films increased monotonically with the drawing ratio and TrGO filler fraction, reaching up to 3.2 ± 0.5 and 109.3 ± 12.7 GPa, respectively, with a drawing ratio of 60× and a very low TrGO weight fraction of 1%. These values represent by far the highest reported to date for a polymer/graphene composite. Experimental characterizations indicate that as the polymer films are drawn, TrGO fillers are exfoliated, which is further confirmed by molecular dynamics (MD) simulations. Exfoliation increases the specific area of the TrGO fillers in contact with the PE matrix molecules. Molecular dynamics simulations show that the PE-TrGO interaction is stronger than the PE-PE intermolecular van der Waals interaction, which enhances load transfer from PE to TrGO and leverages the ultrahigh mechanical properties of TrGO.

4.
Small ; 14(35): e1801657, 2018 Aug.
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.

5.
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.

6.
Int J Surg ; 43: 126-130, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28578082

RESUMO

OBJECTIVE: This study mainly aimed to evaluate complications of cement leakage for osteoporotic thoracolumbar vertebral compression fractures by PVP using HVC, and access the clinical efficacy. METHODS: Between May 2013 and June 2015, 66 patients with osteoporotic thoracolumbar vertebral compression fractures, who underwent PVP (36 HVC and 30 LVC) in our hospital, were enrolled. Cement leakage, Visual Analog Scale (VAS), Oswestry Disability Index (ODI), refracture of the cemented vertebrae, and adjacent vertebral fractures were evaluated. The follow-up time was 1 year. RESULTS: The overall cement leakage rate was 30.55% in the HVC group, lower than 77.77% obtained in the LVC group (P = 0.00). The incidence rates of cement leakage into paravertebral area (P = 0.02) and vein (P = 0.04) in the HVC group were significantly lower than those of the LVC group; however, no differences were found for disc space (P = 0.72) and intraspinal space (P = 0.58). There were no differences in VAS, ODI, refracture of cemented vertebrae, and adjacent vertebral fracture between the two groups (P > 0.05). CONCLUSIONS: PVP using HVC not only can reduce cement leakage, especially in the paravertebral area and peripheral vein, but also has satisfactory clinical effect.


Assuntos
Cimentos para Ossos , Fraturas por Compressão/cirurgia , Vértebras Lombares/lesões , Fraturas por Osteoporose/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Vértebras Torácicas/lesões , Vertebroplastia/métodos , Idoso , Feminino , Humanos , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Vértebras Torácicas/cirurgia , Viscosidade , Escala Visual Analógica
7.
ACS Nano ; 11(6): 5510-5518, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28511003

RESUMO

The ability to efficiently utilize solar thermal energy to enable liquid-to-vapor phase transition has great technological implications for a wide variety of applications, such as water treatment and chemical fractionation. Here, we demonstrate that functionalizing graphene using hydrophilic groups can greatly enhance the solar thermal steam generation efficiency. Our results show that specially functionalized graphene can improve the overall solar-to-vapor efficiency from 38% to 48% at one sun conditions compared to chemically reduced graphene oxide. Our experiments show that such an improvement is a surface effect mainly attributed to the more hydrophilic feature of functionalized graphene, which influences the water meniscus profile at the vapor-liquid interface due to capillary effect. This will lead to thinner water films close to the three-phase contact line, where the water surface temperature is higher since the resistance of thinner water film is smaller, leading to more efficient evaporation. This strategy of functionalizing graphene to make it more hydrophilic can be potentially integrated with the existing macroscopic heat isolation strategies to further improve the overall solar-to-vapor conversion efficiency.

8.
Medicine (Baltimore) ; 96(12): e6437, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28328853

RESUMO

BACKGROUND: Current studies evaluating the association of tea consumption and bone mineral density (BMD) have yielded inconsistent findings. Therefore, we conducted a meta-analysis to assess the relationship between tea consumption and BMD. METHODS: The PubMed, Embase, and Cochrane Library databases were comprehensively searched, and a meta-analysis performed of all observational studies assessing the association of tea consumption and BMD. Forest plots were used to illustrate the results graphically. The Q-test and I statistic were employed to evaluate between-study heterogeneity. Potential publication bias was assessed by the funnel plot. RESULTS: Four cohort, 1 case-control, and 8 cross-sectional studies including a total of 12,635 cases were included. Tea consumption was shown to prevent bone loss [odds ratio (OR): 0.66; 95% confidence interval (CI), 0.47-0.94; P = 0.02], yielding higher mineral densities in several bones, including the lumbar spine [standardized mean difference (SMD): 0.19; 95% CI, 0.08-0.31; P = 0.001], hip (SMD: 0.19; 95% CI, 0.05-0.34; P = 0.01), femoral neck [mean difference (MD): 0.01; 95% CI, 0.00-0.02; P = 0.04], Ward triangle (MD: 0.02; 95% CI, 0.01-0.04; P = 0.001), and greater trochanter (MD: 0.03; 95% CI, 0.02-0.04; P < 0.00001), than the non-tea consumption group. CONCLUSION: This meta-analysis provided a potential trend that tea consumption might be beneficial for BMD, especially in the lumbar spine, hip, femoral neck, Ward triangle, and greater trochanter, which might help prevent bone loss.


Assuntos
Densidade Óssea/efeitos dos fármacos , Chá , Fêmur/efeitos dos fármacos , Colo do Fêmur/efeitos dos fármacos , Humanos , Vértebras Lombares/efeitos dos fármacos , Estudos Observacionais como Assunto , Osteoporose/prevenção & controle , Ossos Pélvicos/efeitos dos fármacos
9.
Zhongguo Gu Shang ; 29(5): 404-7, 2016 May.
Artigo em Chinês | MEDLINE | ID: mdl-27505954

RESUMO

OBJECTIVE: To evaluate clinical outcomes of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction under arthroscopy combined with limited open repair of medial collateral ligament (MCL) for the treatment of multiple ligament injuries of knee joints. METHODS: From March 2006 and June 2012,the data of 14 patients (14 knees) with multiple injuries of ACL, PCL, and MCL were collected. There were 8 males and 6 females with an average age of (31.8 +/- 8.1) years old (ranged, 20 to 49 years old). All the patients were performed with X-ray and MRI examination, and the results showed that 10 patients had combined with injuries of anterior cruciate ligament (ACL), posterior cruciate ligament (PCL) and medial collateral ligament (MCL); 4 patients had ALC,PCL and posterolateral corner (PLC) injuries. Four patients had medial meniscus injuries and 2 patients had lateral meniscus injuries. The MCL,PLC and meniscus injuries were treated with operation on the first stage, and functional exercises were performed 3 weeks after fixation. The reconstruction operation of ACL and (or) PCL was performed at the second stage under arthroscopy 3 to 6 months later when the movement range of knee joint recovered to the normal level with obvious relaxation. RESULTS: All incisions healed by primary intention. All the patients were followed up with a mean duration of 48.9 months (ranged, 24 to 80 months). The Lysholm score was improved from preoperative 19.6 +/- 0.9 to the latest follow-up 87.1 +/- 2.8 (t=12.3, P<0.01). The International Knee Documentation Committee (IKDC) rating: 9 cases nearly recovered to normal, 5 cases were abnormal. CONCLUSION: For multiple ligament injuries in the knee, staged repair and reconstruction can effectively restore knee joint stability and function.


Assuntos
Ligamento Cruzado Anterior/cirurgia , Traumatismos do Joelho/cirurgia , Ligamento Cruzado Posterior/cirurgia , Adulto , Lesões do Ligamento Cruzado Anterior , Feminino , Seguimentos , Humanos , Traumatismos do Joelho/fisiopatologia , Articulação do Joelho/fisiopatologia , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Ligamento Cruzado Posterior/lesões , Procedimentos Cirúrgicos Reconstrutivos , Resultado do Tratamento , Adulto Jovem
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