Assembly of graphene into functional macroscopic objects, such as fi lms, [ 1 ] sheets, [ 2 ] fi bers, [ 3 ] foams, [ 4,5 ] and other complex architectures, [ 6 ] is of enormous research interest. How to attain desired structures in a cost effective and manufacturable manner is crucial for energy harvest/storage, catalysis, sensors and so on. Unlike fullerene or carbon nanotubes, whose assembly generally relies on weak van der Walls force or chemical modifi cation, two-dimensional graphene may straightforwardly exploit strong interlayer π -π stacking. Unfortunately, such a strong and directional interaction frequently results in graphitic stacking with minimal surface area. [ 7,8 ] Gelation is a straightforward route to macroscopic functional materials from graphene. Taking advantage of high electrical conductivity, large surface area, and soft hydrated character, graphene gel possesses enormous potentials for supercapacitor electrode, [9][10][11][12] catalytic support, [ 13,14 ] cell growth scaffold [ 15 ] and so on. [ 16,17 ] To date, several graphene gelation principles have been developed, including reduction of graphene oxide (GO) dispersion, [ 9,10,18 ] fl ow directed interfacial assembly [ 19 ] and template assembly. [ 20 ] Nevertheless, arbitrary large scale production of optimized porous structures via minimal processing steps remains formidable technological challenge.We present a surprisingly simple and versatile graphene gelation principle capable of three-dimensional shape engineering of micrometer thick hydrogels without any practical size limit. Simple immersion of arbitrary shaped Zn objects in aqueous GO dispersion spontaneously generates graphene hydrogel fi lms at Zn surfaces. This site specifi c gelation enables a wide range controllability of three-dimensional gel structures in porous morphology as well as macroscopic object scale according to customized purposes. Signifi cantly, this gelation principle has been exploited for high rate, large capacity supercapacitor electrodes. In general, fast charging/discharging rate (or power density) is hardly compatible with large areal capacity [21][22][23] (or energy density) for energy devices. While thin supercapacitor electrodes with facile electrolyte transports are favorable for high rate capacity, thick electrodes are desired for large areal capacity. [24][25][26] In this work, three-dimensional controllability of graphene gel morphology optimized the aqueous electrolyte transport within suffi ciently thick gel structures. Consequently, fundamental challenge to attain large areal capacity without sacrifi cing rate capability is successfully addressed.Synthetic scheme of graphene hydrogel is presented in Figure 1 a. While Zn foils are immersed in mild acidic dispersion of GO, black graphene hydrogels spontaneously grow at Zn surface. The grown gel thickness is roughly tunable with immersion time. Typically, one hour deposition produced 78-μ m-thick gel fi lms in 10 −3 M hydrochlorid acid (HCl) containing GO dispersion (Supporting information, Fig...
The utilization of 3D computerized systems has allowed more effective procedures for forensic facial reconstruction. Three 3D computerized facial reconstructions were produced using skull models from live adult Korean subjects to assess facial morphology prediction accuracy. The 3D skeletal and facial data were recorded from the subjects in an upright position using a cone-beam CT scanner. Shell-to-shell deviation maps were created using 3D surface comparison software, and the deviation errors between the reconstructed and target faces were measured. Results showed that 54%, 65%, and 77% of the three facial reconstruction surfaces had <2.5 mm of error when compared to the relevant target face. The average error for each reconstruction was -0.46 mm (SD = 2.81) for A, -0.31 mm (SD = 2.40) for B, and -0.49 mm (SD = 2.16) for C. The facial features of the reconstructions demonstrated good levels of accuracy compared to the target faces.
One hundred Korean adults (50 men, 50 women) were scanned in the upright position using a cone-beam CT (CBCT) scanner. The soft tissue (ST) thicknesses were measured at 31 landmarks, 10 midline and 21 bilateral landmark sites, and the means and standard deviations were obtained for male and female subjects. While 18 of 31 landmarks showed sex differences, the majority showed higher values for male subjects with the exception of a few landmark sites corresponding to the zygoma area, which showed smaller values in men than in women. The mandibular area showed greater differences between the right and left sides. Overall, the ST thickness measurements obtained in this study can be used as a database for the forensic craniofacial reconstruction of Korean adult faces.
BackgroundIncreasing evidence supports an association between age-related loss of muscle mass and insulin resistance. However, the association has not been fully investigated in the general population. Thus, we investigated the association between appendicular skeletal muscle mass (ASM) and insulin resistance in an elderly Korean population.MethodsThis cross-sectional study included 158 men (mean age, 71.8) and 241 women (mean age, 70.6) from the Korean Social Life, Health and Aging Project, which started in 2011. In this study, ASM was measured by bioelectrical impedance analysis and was analyzed in three forms: ASM (kg), ASM/height2 (kg/m2), and ASM/weight (%). The homeostasis model assessment of insulin resistance (HOMA-IR) was used as a measure of insulin resistance. The relationships between the ASM values and the HOMA-IR were investigated by multiple linear regression models.ResultsThe HOMA-IR was positively associated with ASM (β=0.43, P<0.0001) and ASM/height2 (β=0.36, P<0.0001) when adjusted for sex and age. However, after additional adjustment for body weight, HOMA-IR was inversely associated with ASM (β=-0.43, P<0.001) and ASM/height2 (β=-0.30, P=0.001). Adjustment for other potential confounders did not change these associations. Conversely, HOMA-IR was consistently and inversely associated with ASM/weight before and after adjustment for other potential confounders.ConclusionOur results support the idea that lower skeletal muscle mass is independently associated with insulin resistance in older adults. When evaluating sarcopenia or muscle-related conditions in older adults, their whole body sizes also need to be considered.
Given that the insula plays a contributory role in the perception of chronic pain, we examined the resting-state functional connectivity between the insular cortex and other brain regions to investigate neural underpinnings of persisting perception of background pain in patients with complex regional pain syndrome (CRPS). A total of 25 patients with CRPS and 25 matched healthy controls underwent functional magnetic resonance imaging at rest. With the anterior and posterior insular cortices as seed regions, we compared the strength of the resting-state functional connectivity between the two groups. Functional connectivity between the anterior and posterior insular cortices and the postcentral and inferior frontal gyri, cingulate cortices was reduced in patients with CRPS compared with controls. Additionally, greater reductions in functional connectivity between the anterior insula and right postcentral gyrus were associated with more severe sensory pain in patients with CRPS (short-form McGill Pain Questionnaire sensory subscores, r = -.517, P = .023). The present results imply a possible role of the insula in aberrant processing of pain information in patients with CRPS. The findings suggest that a functional derangement of the connection between one of the somatosensory cortical functions of perception and one of the insular functions of awareness can play a significant role in the persistent experience of regional pain that is not confined to a specific nerve territory.
Accuracy is the most important factor supporting the reliability of forensic facial reconstruction (FFR) comparing to the corresponding actual face. A number of methods have been employed to evaluate objective accuracy of FFR. Recently, it has been attempted that the degree of resemblance between computer‐generated FFR and actual face is measured by geometric surface comparison method. In this study, three FFRs were produced employing live adult Korean subjects and three‐dimensional computerized modeling software. The deviations of the facial surfaces between the FFR and the head scan CT of the corresponding subject were analyzed in reverse modeling software. The results were compared with those from a previous study which applied the same methodology as this study except average facial soft tissue depth dataset. Three FFRs of this study that applied updated dataset demonstrated lesser deviation errors between the facial surfaces of the FFR and corresponding subject than those from the previous study. The results proposed that appropriate average tissue depth data are important to increase quantitative accuracy of FFR.
In this study, vertical N-doped carbon nanotube (VNCNT) arrays were decorated with Au, Ru, or Mn nanoparticles, and the effects of the particles on the field-emission properties were investigated. Uniform catalyst nanoparticles were prepared by block copolymer lithography on a graphene film, and the VNCNT arrays were grown from the nanopatterned catalyst particles by plasma-enhanced chemical vapor deposition (PECVD). The surfaces of the VNCNT arrays were subsequently decorated with metal particles, and the vertical alignment of the NCNT arrays was maintained by high-vacuum annealing. The field-emission properties of the metal-particle-decorated VNCNT arrays varied according to the changes in the work-function values, with the Mn-VNCNT field emitter showing the best performance among the emitters tested. Our results revealed that the field-emission properties of VNCNT arrays may be tuned by decoration with metal particles and that particle decoration with a low-work-function material may be used to develop efficient field emitters.
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