4,708 research outputs found

    3D Arbitrary Channel Fabrication for Lab on a Chip Applications using Chemical Decomposition

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    This article demonstrate a simple method to use of three-dimensionally (3D) printed molds that are chemically decomposable for rapid fabrication of complex and arbitrary microchannel geometries. These complex microchannel are unachievable through existing soft lithography techniques. The molds are printed directly from hand held 3D printing pen that can print in midair, making rapid prototyping of microfluidic devices possible in hours. PLA based copper filament is used to print the arbitrary channels. The printed channels are then placed inside PDMS and PDMS is cured. The cured sample is then immersed in chemical solution (Acetic Acid + Sodium Chloride+ Hydrogen peroxide), which decomposes the PLA based copper channel thus leaving an empty channel inside the PDMS block. This method enable precise control of various device geometries, such as the profile of the channel cross-section and variable channel diameters in a single device

    Septal perforators stemming from a very long left main coronary artery

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    We report a case of a very long left main coronary artery, 58mm,  with septal perforators before bifurcation. The coronary arteries were seen clear of plaques. To the best of our knowledge this case is a very rare case because of the existance of the first and the second septal perforator arteries originating from a very long left main coronary artery

    An Ensemble of Optimal Trees for Classification and Regression (OTE)

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    Predictive performance of a random forest ensemble is highly associated with the strength of individual trees and their diversity. Ensemble of a small number of accurate and diverse trees, if prediction accuracy is not compromised, will also reduce computational burden. We investigate the idea of integrating trees that are accurate and diverse. For this purpose, we utilize out-of-bag observation as validation sample from the training bootstrap samples to choose the best trees based on their individual performance and then assess these trees for diversity using Brier score. Starting from the first best tree, a tree is selected for the final ensemble if its addition to the forest reduces error of the trees that have already been added. A total of 35 bench mark problems on classification and regression are used to assess the performance of the proposed method and compare it with kNN, tree, random forest, node harvest and support vector machine. We compute unexplained variances and classification error rates for all the methods on the corresponding data sets. Our experiments reveal that the size of the ensemble is reduced significantly and better results are obtained in most of the cases. For further verification, a simulation study is also given where four tree style scenarios are considered to generate data sets with several structures

    Evaluation of Abelmoschus moschatus extracts for antioxidant, free radical scavenging, antimicrobial and antiproliferative activities using in vitro assays

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    <p>Abstract</p> <p>Background</p> <p><it>Abelmoschus moschatus </it>Medik. leaves and seeds are considered as valuable traditional medicine. The aromatic seeds of this plant are aphrodisiac, ophthalmic, cardio tonic, antispasmodic and used in the treatment of intestinal complaints and check queasiness. To give a scientific basis for traditional usage of this medicinal plant, the seed and leaf extracts were evaluated for their antioxidant, free radical scavenging, antimicrobial and antiproliferative activities.</p> <p>Methods</p> <p>In this study, antioxidant, antimicrobial and antiproliferative activities of <it>A. moschatus </it>extracts were evaluated in a series of <it>in vitro </it>assay involving free radicals, reactive oxygen species and their IC<sub>50 </sub>values were also determined. The antioxidant activities of the seed and leaf extracts of <it>A. moschatus </it>were determined by total antioxidant, DPPH, and ferrous reducing antioxidant property (FRAP) methods. In addition, the antiproliferative activity was also evaluated using colorectal adenocarcinoma and retinoblastoma human cancer cell lines. Moreover, six bacterial reference strains, two gram-positive (<it>Bacillus subtilis </it>and <it>Staphylococcus aureus</it>), four gram-negative (<it>Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris </it>and <it>Salmonella enterica paratyphi</it>) and one fungal strain (<it>Candida albicans</it>) were used to evaluate its antimicrobial activity.</p> <p>Results</p> <p>The results from this study showed that the antioxidant activities of <it>A. moschatus </it>as determined by the total phenol, flavonoids, total antioxidant and FRAP methods were higher in leaf than that of the seed extracts. On the other hand, the aqueous overnight seed extract (AMS-I) has shown significant radical scavenging activity as in 1, 1- Diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide, hydroxyl radical, superoxide and lipid peroxidation as compared to other seed and leaf extracts. The AMS-I and AML-IV have shown activity against six and seven microorganisms respectively. Simulteneously, AMS-IV and AML-IV have demonstrated potential antiproliferative activity against two human cell lines - Colorectal adenocarcinoma (COLO-205) and retinoblastoma (Y79).</p> <p>Conclusion</p> <p>The seed and leaf extracts of <it>A. moschatus </it>possess significant antioxidant activity and could serve as free radical inhibitors or scavenger, or substitute, probably as primary antioxidants. The plant possesses moderate antibacterial activity against bacterial strains used in this study. Hydroalcoholic seed and leaf extracts also exhibited antiproliferative activity against two human cancer cell lines. <it>A. moschatus </it>may therefore, be a good candidate for functional foods as well as pharmaceutics.</p

    Trends in breeding oat for nutritional grain quality - An overview

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    Oat is an economically important crop and ranks sixth in world cereal production after maize, wheat, rice, barley and sorghum. It has been primarily utilized as livestock feed. However, the utilization of oats for human consumption has increased progressively, owing to its dietary and health benefits which relies mainly on the total dietary fibre and ?-glucan content, which significantly reduces postprandial blood glucose, insulin and blood lipids, especially serum total and low density lipoprotein cholesterol. Henceforth, enhancing Oat b-glucan content forhuman consumption is desirable. As it is a polygenic trait controlled mainly by genes with additive effects, phenotypic selection for greater b-glucan content would be effective for developing cultivars with elevated b-glucan contents. Oat b-glucan concentration has been found to be positively correlated with protein content and negatively correlated with oil content. ?-glucan yield (i.e., Product of grain yield and ?-glucan content) has been found to correlate positively with both grain yield (r = 0.92) and ?-glucan content (r = 0.66). Hence, this nutritional oat grain quality has been improved through selection for improved grain yield as they both increase simultaneously. Among wild accessions, A. atlantica genotypes have high ?-glucan content (2·2–11·3%) and have been used in breeding programmes for increasing the ?-glucan content of adapted elite local germplasm. Besides conventional breeding approaches, molecular breeding approaches have made possible to identify several molecular markers linked to ?-glucan rich regions across oat genome hence enabling mapping and dissection of ?-glucan rich genomic regions and accelerating the improvement in nutritional grain quality

    HERB YIELD AND CHEMICAL COMPOSITION OF BASIL (OCIMUM BASILICUM L) ESSENTIAL OIL IN RELATION TO THE DIFFERENT HARVEST PERIOD AND CULTIVATION CONDITIONS

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    Background: Ocimum basilicum L., commonly known as sweet basil, is an important aromatic plant cultivated in many parts of the world for its essential oil. Basil does not show natural distribution in Turkey but they are cultivated as medicinal, seasoning or oil plants especially in the western and southern Anatolia. In this study, introduction of new production patterns of green and purple basil into Rize province in the northern parts of Turkey is the main objective of the present study. In this context, herb yield and chemical composition (essential oil and its components) of green and purple basil plants grown under open field and underneath or between kiwi plantations were determined and compared. Materials and Methods: The experiments were arranged as a split plot design with three replications in May in 2010 and 2011 in open-field conditions and between kiwi plantations. Three harvests were done for each year. After each harvest, above ground parts were dried at 35 ºC and essential oils from aerial parts after each harvest were extracted using 30 g of dried material by hydro distillation (4 h) with Neo-Clevenger apparatus. The essential oil compositions were identified by GC-MS. Results: There were decline trends with respect to the plant height, fresh and dry herb yield in the second year. For both experimental years, the highest fresh and dry herb-yields were obtained in open-field conditions in green basil. There were no statistically significant differences in relation to essential oil yield in open-field conditions and kiwi plantations but the highest essential content was ascertained in open-field conditions for green basil. The major aroma constituents of basil were methyl cinnamate and linalool and the highest percentage was determined in open-field conditions for green basil. Conclusion: The lowest essential content obtained in open-field and between kiwi plantations for green and purple basil plants was even higher than the limit (%0.3) established by Turkish Standards Institution and total yield concerned with fresh and dry herb yield complied with the previously proposed literatures. Hence, basil cultivation underneath kiwi plantations may be implemented

    Utilization of microfluidic V-junction device to prepare surface itraconazole adsorbed nanospheres.

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    Itraconazole is widely used as an anti-fungal drug to treat infections. However its poor aqueous solubility results in low bioavailability. The aim of the present study was to improve the drug release profile by preparing surface itraconazole adsorbed polymethylsilsesquioxane (PMSQ) nanospheres using a V-junction microfluidic (VJM) device. In order to generate nanospheres with rough surface, the process flow rate of Perfluorohexane (PFH) was set between 50 and 300 μl min(-1) while the flow rate of PMSQ and itraconazole solution were constant at 300 μl min(-1). Variations in the PFH flow rate enable the controlled size generation of nanospheres. PMSQ nanospheres adsorbing itraconazole were characterized by SEM, FTIR and Zetasizer. The release of itraconazole from PMSQ nanosphere surface was measured using UV spectroscopy. Nanosphere formulations with a range of sphere size (120, 320 and 800nm diameter) were generated and drug release was studied. 120nm itraconazole coated PMSQ nanospheres were found to present highest drug encapsulation efficiency and 13% drug loading in a more reproducible manner compared to 320nm and 800nm sized nanosphere formulations. Moreover 120nm itraconazole coated PMSQ nanospheres (encapsulation efficiency: 88%) showed higher encapsulation efficiency compared to 320nm (encapsulation efficiency: 74%) and 800nm (encapsulation efficiency: 62%) sized nanosphere formulations. The itraconazole coated PMSQ nanospheres were prepared continuously at rate of 2.6×10(6) per minute via VJM device. Overall the VJM device enabled the preparation of monodisperse surface itraconazole adsorbed nanospheres with controlled in vitro drug release profile
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