Anodic aluminum oxide (AAO), typical material with a self-organized porous structure, has recently attracted due to its many potential technical applications such as magnetic, electronic, and optoelectronic device (Whitney et al., 1993 and Rahman and Yang, 2003). There is a great demand for highly ordered and patterned nano-pore arrays. These studies have been reported by prepatterning the Al films and lithographical approaches (Sun and Kim, 2002 and Yasui et al., 2005). To array alumina pore, in this study, Cr and SiO 2 layer deposited on Al thin film, which were patterned by electron beam lithography and ion milling and were used as anodizing mask before anodizing. The effects of mask pattern on alumina pore array were investigated by the various shape and size of Cr mask and different anodic voltage during the anodizing process.
Silver nanoparticles have been used for a variety of consumer products which may directly contact the skin. This study aims to investigate genotoxicity in vitro and skin penetration of silver (Ag) nanoparticles of varying sizes in male SKH1-hairless mice. Dorsal skin of six-week-old hairless mice was treated with 5-10, 100, and 160 nm silver nanoparticles at 1, 10, and 100 mg/kg body weight for 1 month. After dermal exposure of size-dependent silver nanoparticles for 4weeks, blood, urine and organ distribution of silver nanoparticles was measured by ICP-MS (inductively coupled plasma mass spectrometry) analysis. In case of 5-10nm silver nanoparticle treatment, silver concentrations were increased in a dosedependent manner at all measured organs and body fluid. Silver nanoparticles were absorbed through the skin and distributed in the body. The concentrations of silver nanoparticles were highest in the liver among various organs measured and followed by kidney, heart, and brain (liver>kidney>heart> urine>brain>blood in order). In 100 nm and 160 nm silver nanoparticles treatment groups, silver concentrations in the organs and body fluids were also increased in a dose-dependent manner. Blood biochemistry showed that GOT (glutamic oxaloacetic transaminase), ALP (alkaline phosphatase), TG (triglyceride), and BUN (blood urea nitrogen) values were significantly increased in the sera from high-dose group (5-10nm). Mutagenicity tests showed that Ag nanoparticles alone are not genotoxic, but genotoxic in combination of Fe++ or Cu++. These results suggest that silver nanoparticles, dependent on particle size and concenration, are able to be absorbed through the skin and may produce hepatotoxicity in vivo and genotoxicity in the presence of metal ions such as Fe++ or Cu++
Aloe has been used in versatile herbal medications and nutraceuticals throughout history. Aloe is widely considered to be generally safe for humans and used globally. The effectiveness and pharmacological properties of aloe are dependent upon when the plant is collected. However, little is known about the toxicology of whole-body aloe collected within less than 1 yr. Based upon widespread exposure to aloe, it is important to determine a daily intake level of this chemical to ensure its safety for humans. To determine the no-observed-adverse-effect level (NOAEL) of baby aloe powder (BAP) for clinical application, Sprague-Dawley (SD) rats were treated orally for 4 wk with 4 different concentrations: 0, 0.125, 0.5, and 2 g/kg body weight (bw). In this study, no significant or dose-dependent toxicological effects of BAP were observed in biochemical or hematological parameters, urinalysis, clinical signs, body weight, and food and water consumption. There were changes in some biomarkers in certain treated groups compared to controls; however, all values were within their reference ranges and not dose-dependent. Based on these results, the NOAEL of BAP was estimated to be greater than 2 g/kg bw in male and 2 g/kg bw in female SD rats. Collectively, these data suggest that BAP used in this study did not produce any marked subacute toxic effects up to a maximum concentration of 2 g/kg bw, and thus use in nutraceuticals and in pharmaceutical and cosmetic applications at a concentration of >2 g/kg is warranted.
Abstract Plasticizers or plastic materials such as phthalates, bisphenol-A (BPA), and styrene are widely used in the plastic industry and are suspected endocrine-disrupting chemicals (EDC). Although plastic materials such as polypropylene (PP) and polyethylene terephthalate (PET) are not EDC and are considered to be safe, their potential properties as EDC have not been fully investigated. In this study, plastic samples eluted from plastic food containers (PP or PET) were investigated in Sprague-Dawley rats using Hershberger and uterotrophic assays. In the Hershberger assay, 6-wk-old castrated male rats were orally treated for 10 consecutive days with plastic effluent at 3 different doses (5 ml/kg) or vehicle control (corn oil, 1 ml/100 g) to determine the presence of both anti-androgenic and androgenic effects. Testosterone (0.4 mg/ml/kg) was subcutaneously administered for androgenic evaluation as a positive control, whereas testosterone (0.4 mg/ml/kg) and flutamide (3 mg/kg/day) were administered to a positive control group for anti-androgenic evaluation. The presence of any anti-androgenic or androgenic activities of plastic effluent was not detected. Sex accessory tissues such as ventral prostate or seminal vesicle showed no significant differences in weight between treated and control groups. For the uterotrophic assay, immature female rats were treated with plastic effluent at three different doses (5 ml/kg), with vehicle control (corn oil, 1 ml/100 g), or with ethinyl estradiol (3 μg/kg/d) for 3 d. There were no significant differences between test and control groups in vagina or uterine weight. Data suggest that effluents from plastic food containers do not appear to produce significant adverse effects according to Hershberger and uterotrophic assays. Acknowledgments We are grateful to Dr. Kyu-Bong Kim, Dankook University for critical review of the article and to the Korea Food and Drug administration (KFDA) for technical support.
Exposure and risk assessment was performed by evaluating levels of volatile organic compounds (VOC) benzene, toluene, ethylbenzene, and xylene (BTEX) in 207 consumer products. The products were categorized into 30 different items, consisting of products of different brands. Samples were analyzed for BTEX by headspace-gas chromatography/mass spectrometry (headspace-GC/MS) with limit of detection (LOD) of 1 ppm. BTEX were detected in 59 consumer products from 18 item types. Benzene was detected in whiteout (ranging from not detected [ND] to 3170 ppm), glue (1486 ppm), oil-based ballpoint pens (47 ppm), and permanent (marking) pens (2 ppm). Toluene was detected in a leather cleaning product (6071 ppm), glue (5078 ppm), whiteout (1130 ppm), self-adhesive wallpaper (15–1012 ppm), shoe polish (806 ppm), permanent pen (609 ppm), wig adhesive (372 ppm), tapes (2–360 ppm), oil-based ballpoint pen (201 ppm), duplex wallpaper (12–52 ppm), shoes (27 ppm), and air freshener (13 ppm). High levels of ethylbenzene were detected in permanent pen (ND–345,065 ppm), shoe polish (ND–277,928 ppm), leather cleaner (42,223 ppm), whiteout (ND–2,770 ppm), and glue (ND–792 ppm). Xylene was detected in permanent pen (ND–285,132 ppm), shoe polish (ND–87,298 ppm), leather cleaner (12,266 ppm), glue (ND–3,124 ppm), and whiteout (ND–1,400 ppm). Exposure assessment showed that the exposure to ethylbenzene from permanent pens ranged from 0 to 3.11 mg/kg/d (men) and 0 to 3.75 mg/kg/d (women), while for xylene, the exposure ranges were 0–2.57 mg/kg/d and 0–3.1 mg/kg/d in men and women, respectively. The exposure of women to benzene from whiteout ranged from 0 to 0.00059 mg/kg/d. Hazard index (HI), defined as a ratio of exposure to reference dose (RfD), for ethylbenzene was 31.1 (3.11 mg/kg/d/0.1 mg/kg/d) and for xylene (2.57 mg/kg/d/0.2 mg/kg/d) was 12.85, exceeding 1 for both compounds. Cancer risk for benzene was calculated to be 3.2 × 10−5 based on (0.00059 mg/kg/d × 0.055 mg/kg-d−1, cancer potency factor), assuming that 100% of detected levels in some products such as permanent pens and whiteouts were exposed in a worst-case scenario. These data suggest that exposure to VOC via some consumer products exceeded the safe limits and needs to be reduced.
Background/Aim: The use of glycolic acid is present in a variety of consumer products, including medicines, cleaners, cosmetics, and paint strippers. It has recently led to concerns about toxicity from inhalation exposure. Herein, the pulmonary toxicity of glycolic acid was investigated in rats. Materials and Methods: We conducted acute (~458 mg/m3) and sub-acute (~49.5 mg/m3) inhalation tests to identify the potential toxicities of glycolic acid. Results: Inhalation exposure to glycolic acid in the acute and subacute inhalation tests did not cause any specific changes in clinical examinations, including body weight, organ weight, hematology, serum biochemistry, and histopathology. The polymorphonuclear neutrophils (PMNs) and inflammatory cytokines in Bronchoalveolar lavage fluid (BALF) increased in rats exposed to single and repeated inhalations. In the sub-acute test, the changes induced by glycolic acid were minor or returned to normal during the recovery period. Conclusion: The No Observed Adverse Effect Concentration (NOAEC) for the nasal and pulmonary toxicity of glycolic acid was determined to be over 50 mg/m3 at the end of a 28-day inhalation test in male rats.
Recent advances in imaging sensor technology make high frame-rate video capture practical. As demonstrated in previous work, this capability can be used to enhance the performance of many image and video processing applications. The idea is to use the high frame-rate capability to temporally oversample the scene and, thus, to obtain more accurate information about scene motion and illumination. This information is then used to improve the performance of image and standard frame-rate video applications. This paper investigates the use of temporal oversampling to improve the accuracy of optical flow estimation (OFE). A method for obtaining high accuracy optical flow estimates at a conventional standard frame rate, e.g., 30 frames/s, by first capturing and processing a high frame-rate version of the video is presented. The method uses the Lucas-Kanade algorithm to obtain optical flow estimates at a high frame rate, which are then accumulated and refined to estimate the optical flow at the desired standard frame rate. The method demonstrates significant improvements in OFE accuracy both on synthetically generated video sequences and on a real video sequence captured using an experimental high-speed imaging system. It is then shown that a key benefit of using temporal oversampling to estimate optical flow is the reduction in motion aliasing. Using sinusoidal input sequences, the reduction in motion aliasing is identified and the desired minimum sampling rate as a function of the velocity and spatial bandwidth of the scene is determined. Using both synthetic and real video sequences, it is shown that temporal oversampling improves OFE accuracy by reducing motion aliasing not only for areas with large displacements but also for areas with small displacements and high spatial frequencies. The use of other OFE algorithms with temporally oversampled video is then discussed. In particular, the Haussecker algorithm is extended to work with high frame-rate sequences. This extension demonstrates yet another important benefit of temporal oversampling, which is improving OFE accuracy when brightness varies with time.
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