PurposeIn the present study, the visual discomfort induced by smart mobile devices was assessed in normal and healthy adults.MethodsFifty-nine volunteers (age, 38.16 ± 10.23 years; male : female = 19 : 40) were exposed to tablet computer screen stimuli (iPad Air, Apple Inc.) for 1 hour. Participants watched a movie or played a computer game on the tablet computer. Visual fatigue and discomfort were assessed using an asthenopia questionnaire, tear film break-up time, and total ocular wavefront aberration before and after viewing smart mobile devices.ResultsBased on the questionnaire, viewing smart mobile devices for 1 hour significantly increased mean total asthenopia score from 19.59 ± 8.58 to 22.68 ± 9.39 (p < 0.001). Specifically, the scores for five items (tired eyes, sore/aching eyes, irritated eyes, watery eyes, and hot/burning eye) were significantly increased by viewing smart mobile devices. Tear film break-up time significantly decreased from 5.09 ± 1.52 seconds to 4.63 ± 1.34 seconds (p = 0.003). However, total ocular wavefront aberration was unchanged.ConclusionsVisual fatigue and discomfort were significantly induced by viewing smart mobile devices, even though the devices were equipped with state-of-the-art display technology.

Eucommia ulmoides Oliver (Du-zhong) leaf extract was investigated for its antioxidant effects in type 2 diabetic animals, C57BL/KsJ-db/db mice. Du-zhong extract equivalent to 1% dried whole Du-zhong leaf (0.187 g of extract/100 g of diet) was added to the experimental diets for 6 weeks. The Du-zhong extract supplement significantly lowered blood glucose concentrations and elevated plasma paraoxonase activity compared with the control group. The activities of erythrocyte superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were significantly higher in the Du-zhong group compared with the control group, while glutathione reductase (GR) activity was not different between groups. The activities of SOD, GSH-Px, and GR in liver and kidney were not affected by Du-zhong extract supplementation, whereas the CAT activity was significantly higher in the Du-zhong group than in the control group. Du-zhong extract supplementation resulted in lower levels of hydrogen peroxide and lipid peroxide in erythrocytes, liver, and kidney. These results suggest that the antioxidant activity of Du-zhong extract is potentially beneficial for the prevention and management of complications of type 2 diabetes.

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This study attempted to evaluate whether oral lichen planus (OLP) has the potential to progress to oral squamous cell carcinoma (OSCC) by comparing the degree of genetic instability between clinically-curable OLP and lesions that progressed to OSCC. Fifteen cases of steroid-responsive OLP and two cases of lichenoid dysplasia (LD) that progressed to OSCC were used for this study. Chromosome in situ hybridization (CISH) was performed for chromosomes 9 and 17. The fraction of polysomic and monosomic cells for chromosome 9 increased in mucosal epithelium compared to those of lymphocytes in OLP. This difference was statistically significant (P=0.0017, 0.0054, respectively). Two LD patients showed 15.38% and 22.58% of PI for chromosome 9. In OSCC that developed from LD, the fraction of monosomic cells for chromosome 9 increased by more than 70%. We concluded that LD should be treated as a high-risk premalignant lesion and strongly suggest that the monosomy of chromosome 9 may have a critical role in progress to malignancy from LD.

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BackgroundThe aim of this study was to determine the osteoconductivity of biphasic calcium phosphate collagen composite (BCPC) in rabbit calvarial defect model by comparing with biphasic calcium phosphate (BCP). Four 8 mm diameter bicortical calvarial defects were made in ten rabbits. Each of the defects was randomly assigned and filled with 1) collagen sponge, 2) BCP, 3) BCPC, and 4) nothing as control. The animals were sacrificed at either 2 weeks (n = 5) or 8 weeks (n = 5) healing period.ResultsAll groups showed wedge shaped new bone formation limited to the area of the defect margin at both healing periods. The amounts of new bone and defect closure were similar among all groups. In the control and collagen sponge group, the center of the defect was depressed by surrounding tissues. In contrast, in BCP and BCPC group, the center of the defect did not depressed and the grafted materials maintained the space. And the augmented area was significantly higher in BCP and BCPC group compared to the control and collagen sponge group at both healing periods (p < 0.05).ConclusionsThe BCPC and BCP demonstrated proper space maintaining capacity and osteoconductive property, suggesting BCPC can be efficiently utilized in various clinical situations.

into a hydrophobic medium (van Ommen et al., 1988; Hendrickx et al., 1993; Ritsema et al., 1993; Ngu-of drainage in the vadose zone by inducing finger-like flow paths in soils with or without macropores. Recent studies have identified the yen et al., 1999;Carrillo et al., 2000;Wang et al., 2000b), major factors governing fingered flow to be the combined effects of soil air compression during infiltration (White et al., capillary hysteresis, the existence of a threshold water-entry value in a porous medium, and a positive matric potential gradient behind the rated infiltration under low application rates (Selker wetting front. This situation typically occurs during redistribution et al., 1992; Yao and Hendrickx, 1996; Wang et al., following high-rate infiltration, a common occurrence in hydrology. 1998b; Geiger and Durnford, 2000). In addition to these The conditions favoring instability can also develop during infiltration recognized situations, another condition predicted to into a fine-over-coarse layered soil, into hydrophobic or air-entrapped cause unstable flow in uniform porous media is redistrisoils, or even in a homogeneous coarse-textured soil if the infiltration bution following the cessation of infiltration (Raats, rate is low. An analysis of the conditions necessary for the onset of unstable flow in a uniform soil is provided in this paper. We demon-1973; Philip, 1975). Diment and Watson (1985) and Tastrate that if the matric potential gradient (dh/dz ) becomes positive mai et al. (1987) demonstrated that redistribution causes during redistribution, a perturbation at the wetting front will cause unstable flow in coarse-textured, oven-dry, uniform mafinger flow. However, if dh/dz remains negative, the perturbation will terials. However, Diment and Watson's (1985) experibe dissipated. The analysis is used to predict a critical depth of irrigaments in a small slab box showed that redistribution tion (I c ) beyond which the flow should become unstable. A series of "stabilized" when the initial water content was increased point-source and line-source infiltration experiments were conducted to only a few percent of saturation. In contrast, recent using a slab-box filled with uniform sands. The results confirmed that experiments of Wang et al. (2003a, 2003b) in the field as soon as I c is exceeded, a finger was formed at the bottom of the and with a large slab box showed that redistribution is wetting front, channeling the flow and stopping water movement in the surrounding areas. We discuss this phenomenon's implications unstable even in a very wet uniform sand. Nicholl et al. for practical irrigation and leaching designs. Unstable flow causes major uncertainties in the characterization

Abstract:Hydrocarbon compounds in aquifers are generally known to show a retardation effect due to sorption onto the surfaces of solid particles. In this study, we investigated the effect of sorption on the transport of benzene in sandy aquifer materials by conducting batch and column tests for both sandy aquifer materials and sandy materials to which had been added 0Ð5% powdered activated carbon. The batch test was conducted by equilibrating dry materials with benzene solutions of various initial concentrations, and by analysing the concentrations of benzene in the initial and equilibrated solutions using high-performance liquid chromatography (HPLC). The column test was performed to monitor the concentrations of effluent versus time, known as a breakthrough curve (BTC). We injected KCl and benzene solutions as tracers into the inlet boundary as two different types of square pulse and step, and monitored the effluent concentrations at the exit boundary under a steady-state condition using an electrical conductivity meter and HPLC. Simulation of benzene transport was performed using the convective-dispersive equation model with the distribution coefficients obtained from the batch test and the transport parameters of the conservative solute KCl from the column test. The observed BTCs of KCl and benzene for pulse injection showed that the arrival times of the peaks of both tracers coincided well, but the relative peak concentration of benzene was much lower than that of KCl. Comparison of the simulated and observed BTCs showed a great discrepancy for all cases of injection mode and material texture, indicating the absence of retardation effect. These results reveal that the predominant process affecting the benzene transport in the sandy aquifer materials is an irreversible sorption rather than retardation. This tentative conclusion was verified by simulation of benzene transport using an irreversible sorption parameter that led to a good agreement between the simulated and observed BTCs.