960 research outputs found
Enhancing Uptake Capability of Green Carbon Black Recycled from Scrap Tires for Water Purification
This study reports on the highly simple fabrication of green carbon black (GCB) generated from scrap tires with acetic acid to improve the adsorption efficiency for water purification, which is thoroughly compared with conventional carbon black (CB) obtained from petrochemicals. Unlike traditional modification processes with strong acids or bases, the introduction of a relatively mild acid readily allowed for the effective modification of GCB to increase the uptake capability of metal ions and toxic organic dyes to serve as effective adsorbents. The morphological features and thermal decomposition patterns were examined by electron microscopy and thermogravimetric analysis (TGA). The surface functional groups were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The structural information (ratio of D-defects/G band-graphitic domains) obtained by Raman spectroscopy clearly suggested the successful fabrication of GCB (ID/IG ratio of 0.74), which was distinctively different from typical CB (ID/IG ratio of 0.91). In the modified GCB, the specific surface area (SBET) gradually increased with the reduction of pore size as a function of acetic acid content (52.97 m2/g for CB, 86.64 m2/g for GCB, 102.10-119.50 m2/g for acid-treated GCB). The uptake capability of the modified GCB (312.5 mg/g) for metal ions and organic dyes was greater than that of the unmodified GCB (161.3 mg/g) and typical CB (181.8 mg/g), presumably due to the presence of adsorbed acid. Upon testing them as adsorbents in an aqueous solution, all these carbon materials followed the Langmuir isotherm over the Freundlich model. In addition, the removal rates of cationic species (\u3e70% removal of Cu2+ and crystal violet in 30 min) were much faster and far greater than those of anionic metanil yellow (\u3c40% removal in 3 h), given the strong electrostatic interactions. Thus, this work demonstrates the possibility of recycling waste tires in the powder form of GCB as a cost-effective and green adsorbent that can potentially substitute traditional CB, and the modification strategy provides a proof of concept for developing simple fabrication guidelines of other carbonaceous materials
Evolution of ribosomal DNA-derived satellite repeat in tomato genome
<p>Abstract</p> <p>Background</p> <p>Tandemly repeated DNA, also called as satellite DNA, is a common feature of eukaryotic genomes. Satellite repeats can expand and contract dramatically, which may cause genome size variation among genetically-related species. However, the origin and expansion mechanism are not clear yet and needed to be elucidated.</p> <p>Results</p> <p>FISH analysis revealed that the satellite repeat showing homology with intergenic spacer (IGS) of rDNA present in the tomato genome. By comparing the sequences representing distinct stages in the divergence of rDNA repeat with those of canonical rDNA arrays, the molecular mechanism of the evolution of satellite repeat is described. Comprehensive sequence analysis and phylogenetic analysis demonstrated that a long terminal repeat retrotransposon was interrupted into each copy of the 18S rDNA and polymerized by recombination rather than transposition via an RNA intermediate. The repeat was expanded through doubling the number of IGS into the 25S rRNA gene, and also greatly increasing the copy number of type I subrepeat in the IGS of 25-18S rDNA by segmental duplication. Homogenization to a single type of subrepeat in the satellite repeat was achieved as the result of amplifying copy number of the type I subrepeat but eliminating neighboring sequences including the type II subrepeat and rRNA coding sequence from the array. FISH analysis revealed that the satellite repeats are commonly present in closely-related <it>Solanum </it>species, but vary in their distribution and abundance among species.</p> <p>Conclusion</p> <p>These results represent that the dynamic satellite repeats were originated from intergenic spacer of rDNA unit in the tomato genome. This result could serve as an example towards understanding the initiation and the expansion of the satellite repeats in complex eukaryotic genome.</p
Children\u27s exposure to food advertising on free-to-air television: an Asia-Pacific perspective
There is an established link between food promotions and children\u27s food purchase and consumption. Children in developing countries may be more vulnerable to food promotions given the relative novelty of advertising in these markets. This study aimed to determine the scope of television food advertising to children across the Asia-Pacific to inform policies to restrict this marketing. Six sites were sampled, including from China, Indonesia, Malaysia and South Korea. At each site, 192 h of television were recorded (4 days, 16 h/day, three channels) from May to October 2012. Advertised foods were categorized as core/healthy, non-core/unhealthy or miscellaneous, and by product type. Twenty-seven percent of advertisements were for food/beverages, and the most frequently advertised product was sugar-sweetened drinks. Rates of non-core food advertising were highest during viewing times most popular with children, when between 3 (South Korea) and 15 (Indonesia) non-core food advertisements were broadcast each hour. Children in the Asia-Pacific are exposed to high volumes of unhealthy food/beverage television advertising. Different policy arrangements for food advertising are likely to contribute to regional variations in advertising patterns. Cities with the lowest advertising rates can be identified as exemplars of good policy practice
Monitoring Land Surface Albedo and Vegetation Dynamics Using High Spatial and Temporal Resolution Synthetic Time Series from Landsat and the MODIS BRDF/NBAR/Albedo Product
Seasonal vegetation phenology can significantly alter surface albedo which in turn affects the global energy balance and the albedo warmingcooling feedbacks that impact climate change. To monitor and quantify the surface dynamics of heterogeneous landscapes, high temporal and spatial resolution synthetic time series of albedo and the enhanced vegetation index (EVI) were generated from the 500-meter Moderate Resolution Imaging Spectroradiometer (MODIS) operational Collection V006 daily BRDF (Bidirectional Reflectance Distribution Function) / NBAR (Nadir BRDF-Adjusted Reflectance) / albedo products and 30-meter Landsat 5 albedo and near-nadir reflectance data through the use of the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM). The traditional Landsat Albedo (Shuai et al., 2011) makes use of the MODIS BRDFAlbedo products (MCD43) by assigning appropriate BRDFs from coincident MODIS products to each Landsat image to generate a 30-meter Landsat albedo product for that acquisition date. The available cloud free Landsat 5 albedos (due to clouds, generated every 16 days at best) were used in conjunction with the daily MODIS albedos to determine the appropriate 30-meter albedos for the intervening daily time steps in this study. These enhanced daily 30-meter spatial resolution synthetic time series were then used to track albedo and vegetation phenology dynamics over three Ameriflux tower sites (Harvard Forest in 2007, Santa Rita in 2011 and Walker Branch in 2005). These Ameriflux sites were chosen as they are all quite nearby new towers coming on line for the National Ecological Observatory Network (NEON), and thus represent locations which will be served by spatially paired albedo measures in the near future. The availability of data from the NEON towers will greatly expand the sources of tower albedometer data available for evaluation of satellite products. At these three Ameriflux tower sites the synthetic time series of broadband shortwave albedos were evaluated using the tower albedo measurements with a Root Mean Square Error (RMSE) less than 0.013 and a bias within the range of 0.006. These synthetic time series provide much greater spatial detail than the 500 meter gridded MODIS data, especially over more heterogeneous surfaces, which improves the efforts to characterize and monitor the spatial variation across species and communities. The mean of the difference between maximum and minimum synthetic time series of albedo within the MODIS pixels over a subset of satellite data of Harvard Forest (16 kilometers by 14 kilometers) was as high as 0.2 during the snow-covered period and reduced to around 0.1 during the snow-free period. Similarly, we have used STARFM to also couple MODIS Nadir BRDF-Adjusted Reflectances (NBAR) values with Landsat 5 reflectances to generate daily synthetic times series of NBAR and thus Enhanced Vegetation Index (NBAR-EVI) at a 30-meter resolution. While normally STARFM is used with directional reflectances, the use of the view angle corrected daily MODIS NBAR values will provide more consistent time series. These synthetic times series of EVI are shown to capture seasonal vegetation dynamics with finer spatial and temporal details, especially over heterogeneous land surfaces
Stent Fracture at the Proximal Shaft of the Left Main Stem
Stent fracture is likely to be caused due to mechanical stress at the hinge point or kinking movement at the point of aneurysm formation with stent malapposition. To our knowledge, this is the first published report of stent fracture at the proximal shaft of the left main stem in a patient with acute myocardial infarction
The effect of periodontitis on recipient outcomes after kidney transplantation
Background Recent several reports have demonstrated that periodontitis is prevalent and adversely affects the survival in patients with chronic kidney disease (CKD) or end-stage kidney disease. However, its impact on transplant outcomes remains uncertain. Methods This retrospective cohort study included 136 and 167 patients, respectively, who underwent living donor kidney transplantation (KT) at Seoul National University Hospital from July 2012 to August 2016 and Korea University Hospital from April 2008 to October 2018. We divided patients into three groups according to stages of periodontitis based on a new classification system. Results Patients with severe periodontitis were older, had a higher prevalence of diabetes, a higher body mass index and C-reactive protein level, a lower cardiac output, and were more likely to be smokers, indicating its association with chronic systemic inflammation. After KT, stage IV periodontitis was independently associated with a lower incidence of acute T cell-mediated rejection, suggesting the possible effect of periodontitis on immune function. However, 1-year and 3-year estimated glomerular filtration rates were not different. Among the KT recipients followed up more than 3 years, new-onset cardiovascular disease occurred in nine patients, and coronary artery disease occurred more frequently in patients with stage IV periodontitis. However, diabetes was the independent predictor of new-onset coronary artery disease in multivariate logistic regression analysis. Conclusion Our findings showed that periodontitis might be an important player in determining posttransplant outcomes in recipients. Further interventional trials to test whether treating periodontitis could modify transplant outcome are needed
Meeting the 24-h Movement Guidelines and Health-Related Outcomes Among Youth With Autism Spectrum Disorder: A Seven-Country Observational Study
Background: Meeting daily guidelines for physical activity, screen time, and sleep duration is associated with a host of health indicators for youth. In this cross-sectional observational study, we investigated the associations between adherence to the movement guidelines and health-related outcomes among youth with autism spectrum disorder (ASD).
Methods: Parents of youth with ASD (10-17 years) from seven countries and regions were invited to provide online proxy-reports for child\u27s movement behaviors (i.e., physical activity, sleep and screen time), and health-related outcomes (i.e., body mass index [BMI], general health, and quality of life). A series of multiple linear regression analyses were used to examine the associations between meeting movement guidelines and health-related outcomes, adjusted for covariates.
Results: The final sample consisted of 1165 youth with ASD. Compared with youth meeting all three guidelines, a higher BMI z-score was observed in those who met no guidelines (B = 0.62, P = 0.04), sedentary time only (B = 0.60, P = 0.047), and physical activity plus sleep only (B = 0.85, P = 0.04). Compared with meeting all three guidelines, meeting no guidelines was associated with poorer general health (B = - 0.46, P = 0.02). Further, compared with youth meeting all three guidelines, a lower quality of life score was observed in those who met no guidelines (B = - 0.47, P = 0.02) and physical activity only (B = - 0.62, P = 0.03). Lastly, there were dose-response associations between the number of guidelines met and all three health-related outcomes (all P(trend) \u3c 0.05).
Conclusions: In conclusion, meeting more 24-h movement guidelines was generally associated with more favorable health-related outcomes in youth with ASD. The low level of adherence to all three guidelines (2.0%) suggests the urgent need to promote the adoption of all the guidelines in this group
The effect of probiotic supplementation on systemic inflammation in dialysis patients
Background Emerging evidence suggests that intestinal dysbiosis contributes to systemic inflammation and cardiovascular diseases in dialysis patients. The purpose of this study was to evaluate the effects of probiotic supplementation on various inflammatory parameters in hemodialysis (HD) patients. Methods Twenty-two patients with maintenance HD were enrolled. These patients were treated twice a day with 2.0 ×1010 colony forming units of a combination of Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI for 3 months. The microbiome and fecal short-chain fatty acids (SCFAs) were analyzed. The percentages of CD14+ CD16+ proinflammatory monocytes and CD4+ CD25+ regulatory T-cells (Tregs) before and after probiotic supplementation were determined by flow cytometry. Serum levels of calprotectin and cytokine responses upon lipopolysaccharide (LPS) challenge were compared before and after probiotic supplementation. Results Fecal SCFAs increased significantly after probiotic supplementation. Serum levels of calprotectin and interleukin 6 upon LPS stimulation significantly decreased. The anti-inflammatory effects of probiotics were associated with a significant increase in the percentage of CD4+ CD25+ Tregs (3.5% vs. 8.6%, p < 0.05) and also with a decrease of CD14+ CD16+ proinflammatory monocytes (310/mm2 vs. 194/mm2, p < 0.05). Conclusion Probiotic supplementation reduced systemic inflammatory responses in HD patients and this effect was associated with an increase in Tregs and a decrease in proinflammatory monocytes. Hence, targeting intestinal dysbiosis might be a novel strategy for decreasing inflammation and cardiovascular risks in HD patients
Treatment and Outcomes of Melanoma in Acral Location in Korean Patients
PURPOSE: A retrospective study was conducted to review the treatment and outcomes of mainly melanomas in acral location in a single institution in Korea, and to evaluate the prognostic significance of anatomic locations of the tumor.
MATERIALS AND METHODS: A retrospective review was completed on 40 patients between 2001 and 2006 to obtain pertinent demographic data, tumor data, treatment characteristics, and follow-up data.
RESULTS: Forty melanoma patients were identified and analyzed. Of these, 18 were male and 22 were female patients and the mean age at the time of diagnosis was 55.9 years. Of the tumors, 65% were located on the hands and feet with acral lentiginous melanoma being the most common histological subtype. Univariate analysis for the overall melanoma survival revealed that the thickness of the tumor and the clinical stage have prognostic significances. The most significant factor as analyzed by a multivariate analysis was shown to be the advanced clinical stage. Acral melanomas did not show statistically significant differences in the age at diagnosis, thickness of the tumor, stage, ulceration, and survival rates compared to non-acral melanomas. There was also no significant difference in the survival rate between the patients treated by amputation versus wide local excision in acral melanomas.
CONCLUSION: In Korean melanoma patients, thickness and advanced stages are significant factors for poorer prognosis. However, the location of melanoma did not have a significant prognostic value. In treating the melanomas in acral location, local wide excisions resulted in a similar prognosis compared to amputations.ope
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