Search results for: amino acid ionic liquids
1087 Impact of Electric Field on the Optical Properties of Hydrophilic Quantum Dots
Authors: Valentina V. Goftman, Vladislav A. Pankratov, Alexey V. Markin, Tangi Aubert, Zeger Hens, Sarah De Saeger, Irina Yu. Goryacheva
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The most important requirements for biochemical applicability of quantum dots (QDs) are: 1) the surface cap should render intact or improved optical properties; 2) mono-dispersion and good stability in aqueous phase in a wide range of pH and ionic strength values; 3) presence of functional groups, available for bioconjugation; 4) minimal impact from the environment on the QDs’ properties and, vice versa, minimal influence of the QDs’ components on the environment; and 5) stability against chemical/biochemical/physical influence. The latter is especially important for in vitro and in vivo applications. For example, some physical intracellular delivery strategies (e.g., electroporation) imply a rapid high-voltage electric field impulse in order to temporarily generate hydrophilic pores in the cell plasma membrane, necessary for the passive transportation of QDs into the cell. In this regard, it is interesting to investigate how different capping layers, which can provide high stability and sufficient fluorescent properties of QDs in a water solution, behave under these abnormal conditions. In this contribution, hydrophobic core-shell CdSe/CdS/CdZnS/ZnS QDs (λem=600 nm), produced by means of the Successive Ion Layer Adsorption and Reaction (SILAR) technique, were transferred to a water solution using two of the most commonly used methods: (i) encapsulation in an amphiphilic brush polymer based on poly(maleic anhydride-alt-1-octadecene) (PMAO) modified with polyethylene glycol (PEG) chains and (ii) silica covering. Polymer encapsulation preserves the initial ligands on the QDs’ surface owing to the hydrophobic attraction between the hydrophobic groups of the amphiphilic molecules and the surface hydrophobic groups of the QDs. This covering process allows maintaining the initial fluorescent properties, but it leads to a considerable increase of the QDs’ size. However, covering with a silica shell, by means of the reverse microemulsion method, allows maintaining both size and fluorescent properties of the initial QDs. The obtained water solutions of polymer covered and silica-coated QDs in three different concentrations were exposed to a low-voltage electric field for a short time and the fluorescent properties were investigated. It is shown that the PMAO-PEG polymer acquires some additional charges in the presence of the electric field, which causes repulsion between the polymer and the QDs’ surface. This process destroys the homogeneity of the whole amphiphilic shell and it dramatically decreases the fluorescent properties (dropping to 10% from its initial value) because of the direct contact of the QDs with the strongly oxidative environment (water). In contrast, a silica shell possesses dielectric properties which allow retaining 90% of its initial fluorescence intensity, even after a longer electric impact. Thus, silica shells are clearly a preferable covering for bio-application of QDs, because – besides the high uniform morphology, controlled size and biocompatibility – it allows protecting QDs from oxidation, even under the influence of an electric field.Keywords: electric field, polymer coating, quantum dots, silica covering, stability
Procedia PDF Downloads 4581086 Human Papillomavirus Type 16 E4 Gene Variation as Risk Factor for Cervical Cancer
Authors: Yudi Zhao, Ziyun Zhou, Yueting Yao, Shuying Dai, Zhiling Yan, Longyu Yang, Chuanyin Li, Li Shi, Yufeng Yao
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HPV16 E4 gene plays an important role in viral genome amplification and release. Therefore, a variation of the E4 gene nucleic acid sequence may affect the carcinogenicity of HPV16. In order to understand the relationship between the variation of HPV16 E4 gene and cervical cancer, this study was to amplify and sequence the DNA sequences of E4 genes in 118 HPV16-positive cervical cancer patients and 151 HPV16-positive asymptomatic individuals. After obtaining E4 gene sequences, the phylogenetic trees were constructed by the Neighbor-joining method for gene variation analysis. The results showed that: 1) The distribution of HPV16 variants between the case group and the control group differed greatly (P = 0.015),and the Asian-American(AA)variant was likely to relate to the occurrence of cervical cancer. 2) DNA sequence analysis showed that there were significant differences in the distribution of 8 variants between the case group and the control group (P < 0.05). And 3) In European (EUR) variant, two variations, C3384T (L18L) and A3449G (P39P), were associated with the initiation and development of cervical cancer. The results suggested that the variation of HPV16 E4 gene may be a contributor affecting the occurrence as well as the development of cervical cancer, and different HPV16 variants may have different carcinogenic capability.Keywords: cervical cancer, HPV16, E4 gene, variations
Procedia PDF Downloads 1711085 Heterogeneous Catalytic Hydroesterification of Soybean Oil to Develop a Biodiesel Formation
Authors: O. Mowla, E. Kennedy, M. Stockenhuber
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Finding alternative renewable resources of energy has attracted the attentions in consequence of limitation of the traditional fossil fuel resources, increasing of crude oil price and environmental concern over greenhouse gas emissions. Biodiesel (or Fatty Acid Methyl Esters (FAME)), an alternative energy source, is synthesised from renewable sources such as vegetable oils and animal fats and can be produced from waste oils. FAME can be produced via hydroesterification of oils. The process involves two stages. In the first stage of this process, fatty acids and glycerol are being obtained by hydrolysis of the feed stock oil. In the second stage, the recovered fatty acids are then esterified with an alcohol to methyl esters. The presence of a catalyst accelerates the rate of the hydroesterification reaction of oils. The overarching aim of this study is to find the effect of using zeolite as a catalyst in the heterogeneous hydroesterification of soybean oil. Both stages of the catalytic hydroesterification of soybean oil had been conducted at atmospheric and high-pressure conditions using reflux glass reactor and Parr reactor, respectively. The effect of operating parameters such as temperature and reaction time on the overall yield of biodiesel formation was also investigated.Keywords: biodiesel, heterogeneous catalytic hydroesterification, soybean oil, zeolite
Procedia PDF Downloads 4331084 Identification of Disease Causing DNA Motifs in Human DNA Using Clustering Approach
Authors: G. Tamilpavai, C. Vishnuppriya
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Studying DNA (deoxyribonucleic acid) sequence is useful in biological processes and it is applied in the fields such as diagnostic and forensic research. DNA is the hereditary information in human and almost all other organisms. It is passed to their generations. Earlier stage detection of defective DNA sequence may lead to many developments in the field of Bioinformatics. Nowadays various tedious techniques are used to identify defective DNA. The proposed work is to analyze and identify the cancer-causing DNA motif in a given sequence. Initially the human DNA sequence is separated as k-mers using k-mer separation rule. The separated k-mers are clustered using Self Organizing Map (SOM). Using Levenshtein distance measure, cancer associated DNA motif is identified from the k-mer clusters. Experimental results of this work indicate the presence or absence of cancer causing DNA motif. If the cancer associated DNA motif is found in DNA, it is declared as the cancer disease causing DNA sequence. Otherwise the input human DNA is declared as normal sequence. Finally, elapsed time is calculated for finding the presence of cancer causing DNA motif using clustering formation. It is compared with normal process of finding cancer causing DNA motif. Locating cancer associated motif is easier in cluster formation process than the other one. The proposed work will be an initiative aid for finding genetic disease related research.Keywords: bioinformatics, cancer motif, DNA, k-mers, Levenshtein distance, SOM
Procedia PDF Downloads 1881083 Microstracture of Iranian Processed Cheese
Authors: R. Ezzati, M. Dezyani, H. Mirzaei
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The effects of the concentration of trisodium citrate (TSC) emulsifying salt (0.25 to 2.75%) and holding time (0 to 20 min) on the textural, rheological, and microstructural properties of Iranian Processed Cheese Cheddar cheese were studied using a central composite rotatable design. The loss tangent parameter (from small amplitude oscillatory rheology), extent of flow, and melt area (from the Schreiber test) all indicated that the meltability of process cheese decreased with increased concentration of TSC and that holding time led to a slight reduction in meltability. Hardness increased as the concentration of TSC increased. Fluorescence micrographs indicated that the size of fat droplets decreased with an increase in the concentration of TSC and with longer holding times. Acid-base titration curves indicated that the buffering peak at pH 4.8, which is due to residual colloidal calcium phosphate, decreased as the concentration of TSC increased. The soluble phosphate content increased as concentration of TSC increased. However, the insoluble Ca decreased with increasing concentration of TSC. The results of this study suggest that TSC chelated Ca from colloidal calcium phosphate and dispersed casein; the citrate-Ca complex remained trapped within the process cheese matrix. Increasing the concentration of TSC helped to improve fat emulsification and casein dispersion during cooking, both of which probably helped to reinforce the structure of process cheese.Keywords: Iranian processed cheese, cheddar cheese, emulsifying salt, rheology
Procedia PDF Downloads 4431082 From Primer Generation to Chromosome Identification: A Primer Generation Genotyping Method for Bacterial Identification and Typing
Authors: Wisam H. Benamer, Ehab A. Elfallah, Mohamed A. Elshaari, Farag A. Elshaari
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A challenge for laboratories is to provide bacterial identification and antibiotic sensitivity results within a short time. Hence, advancement in the required technology is desirable to improve timing, accuracy and quality. Even with the current advances in methods used for both phenotypic and genotypic identification of bacteria the need is there to develop method(s) that enhance the outcome of bacteriology laboratories in accuracy and time. The hypothesis introduced here is based on the assumption that the chromosome of any bacteria contains unique sequences that can be used for its identification and typing. The outcome of a pilot study designed to test this hypothesis is reported in this manuscript. Methods: The complete chromosome sequences of several bacterial species were downloaded to use as search targets for unique sequences. Visual basic and SQL server (2014) were used to generate a complete set of 18-base long primers, a process started with reverse translation of randomly chosen 6 amino acids to limit the number of the generated primers. In addition, the software used to scan the downloaded chromosomes using the generated primers for similarities was designed, and the resulting hits were classified according to the number of similar chromosomal sequences, i.e., unique or otherwise. Results: All primers that had identical/similar sequences in the selected genome sequence(s) were classified according to the number of hits in the chromosomes search. Those that were identical to a single site on a single bacterial chromosome were referred to as unique. On the other hand, most generated primers sequences were identical to multiple sites on a single or multiple chromosomes. Following scanning, the generated primers were classified based on ability to differentiate between medically important bacterial and the initial results looks promising. Conclusion: A simple strategy that started by generating primers was introduced; the primers were used to screen bacterial genomes for match. Primer(s) that were uniquely identical to specific DNA sequence on a specific bacterial chromosome were selected. The identified unique sequence can be used in different molecular diagnostic techniques, possibly to identify bacteria. In addition, a single primer that can identify multiple sites in a single chromosome can be exploited for region or genome identification. Although genomes sequences draft of isolates of organism DNA enable high throughput primer design using alignment strategy, and this enhances diagnostic performance in comparison to traditional molecular assays. In this method the generated primers can be used to identify an organism before the draft sequence is completed. In addition, the generated primers can be used to build a bank for easy access of the primers that can be used to identify bacteria.Keywords: bacteria chromosome, bacterial identification, sequence, primer generation
Procedia PDF Downloads 1931081 Rheological Properties and Consumer Acceptability of Supplemented with Flaxseed
Authors: A. Albaridi Najla
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Flaxseed (Linum usitatissimum) is well known to have beneficial effect on health. The seeds are rich in protein, α-linolenic fatty acid and dietary fiber. Bakery products are important part of our daily meals. Functional food recently received considerable attention among consumers. The increase in bread daily consumption leads to the production of breads with functional ingredients such as flaxseed The aim of this Study was to improve the nutritional value of bread by adding flaxseed flour and assessing the effect of adding 0, 5, 10 and 15% flaxseed on whole wheat bread rheological and sensorial properties. The total consumer's acceptability of the flaxseed bread was assessed. Dough characteristics were determined using Farinograph (C.W. Brabender® Instruments, Inc). The result shows no change was observed in water absorption between the stander dough (without flaxseed) and the bread with flaxseed (67%). An Increase in the peak time and dough stickiness was observed with the increase in flaxseed level. Further, breads were evaluated for sensory parameters, colour and texture. High flaxseed level increased the bread crumb softness. Bread with 5% flaxseed was optimized for total sensory evaluation. Overall, flaxseed bread produced in this study was highly acceptable for daily consumption as a functional foods with a potentially health benefits.Keywords: bread, flaxseed, rheological properties, whole-wheat bread
Procedia PDF Downloads 4351080 Sardine Oil as a Source of Lipid in the Diet of Giant Freshwater Prawn (Macrobrachium rosenbergii)
Authors: A. T. Ramachandra Naik, H. Shivananda Murthy, H. n. Anjanayappa
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The freshwater prawn, Macrobrachium rosenbergii is a more popular crustacean cultured widely in monoculture system in India. It has got high nutritional value in the human diet. Hence, understanding its enzymatic and body composition is important in order to judge its flesh quality. Fish oil specially derived from Indian oil sardine is a good source of highly unsaturated fatty acid and lipid source in fish/prawn diet. A 35% crude protein diet with graded levels of Sardine oil as a source of fat was incorporated at four levels viz, 2.07, 4.07, 6.07 and 8.07% maintaining a total lipid level of feed at 8.11, 10.24, 12.28 and 14.33% respectively. Diet without sardine oil (6.05% total lipid) was served as basal treatment. The giant freshwater prawn, Macrobrachium rosenbergii was used as test animal and the experiment was lost for 112 days. Significantly, higher gain in weight of prawn was recorded in the treatment with 6.07% sardine oil incorporation followed by higher specific growth rate, food conversion rate and protein efficiency ratio. The 8.07% sardine oil diet produced the highest RNA: DNA ratio in the prawn muscle. Digestive enzyme analyses in the digestive tract and mid-gut gland showed the greatest activity in prawns fed the 8.07% diet.Keywords: digestive enzyme, fish diet, Macrobrachium rosenbergii, sardine oil
Procedia PDF Downloads 3291079 Isolation and Chemical Characterization of Residual Lignin from Areca Nut Shells
Authors: Dipti Yadav, Latha Rangan, Pinakeswar Mahanta
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Recent fuel-development strategies to reduce oil dependency, mitigate greenhouse gas emissions, and utilize domestic resources have generated interest in the search for alternative sources of fuel supplies. Bioenergy production from lignocellulosic biomass has a great potential. Cellulose, hemicellulose and Lignin are main constituent of woods or agrowaste. In all the industries there are always left over or waste products mainly lignin, due to the heterogeneous nature of wood and pulp fibers and the heterogeneity that exists between individual fibers, no method is currently available for the quantitative isolation of native or residual lignin without the risk of structural changes during the isolation. The potential benefits from finding alternative uses of lignin are extensive, and with a double effect. Lignin can be used to replace fossil-based raw materials in a wide range of products, from plastics to individual chemical products, activated carbon, motor fuels and carbon fibers. Furthermore, if there is a market for lignin for such value-added products, the mills will also have an additional economic incentive to take measures for higher energy efficiency. In this study residual lignin were isolated from areca nut shells by acid hydrolysis and were analyzed and characterized by Fourier Transform Infrared (FTIR), LCMS and complexity of its structure investigated by NMR.Keywords: Areca nut, Lignin, wood, bioenergy
Procedia PDF Downloads 4741078 Efficiency of Pre-Treatment Methods for Biodiesel Production from Mixed Culture of Microalgae
Authors: Malith Premarathne, Shehan Bandara, Kaushalya G. Batawala, Thilini U. Ariyadasa
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The rapid depletion of fossil fuel supplies and the emission of carbon dioxide by their continued combustion have paved the way for increased production of carbon-neutral biodiesel from naturally occurring oil sources. The high biomass growth rate and lipid production of microalgae make it a viable source for biodiesel production compared to conventional feedstock. In Sri Lanka, the production of biodiesel by employing indigenous microalgae species is at its emerging stage. This work was an attempt to compare the various pre-treatment methods before extracting lipids such as autoclaving, microwaving and sonication. A mixed culture of microalgae predominantly consisting of Chlorella sp. was obtained from Beire Lake which is an algae rich, organically polluted water body located in Colombo, Sri Lanka. After each pre-treatment method, a standard solvent extraction using Bligh and Dyer’s method was used to compare the total lipid content in percentage dry weight (% dwt). The fatty acid profiles of the oils extracted with each pretreatment method were analyzed using gas chromatography-mass spectrometry (GC-MS). The properties of the biodiesels were predicted by Biodiesel Analyzer© Version 1.1, in order to compare with ASTM 6751-08 biodiesel standard.Keywords: biodiesel, lipid extraction, microalgae, pre-treatment
Procedia PDF Downloads 1771077 Biological Activities of Gentiana brachyphylla Vill. Herba from Turkey
Authors: Hulya Tuba Kiyan, Nilgun Ozturk
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Gentiana, a member of Gentianaceae, is represented by approximately 400 species in the world and 12 species in Turkey. Flavonoids, iridoids, triterpenoids and also xanthones are the major compounds of this genus, have been previously reported to have antiinflammatory, antimicrobial, antioxidant, hepatoprotective, hypotensive, hypoglycaemic, DNA repair and immunomodulatory properties. The methanolic extract of the aerial parts of Gentiana brachyphylla Vill. from Turkey was evaluated for its biological activities and its total phenolic content in the present study. According to the antioxidant activity results, G. brachyphylla methanolic extract showed very strong anti-DNA damage antioxidant activity with an inhibition of 81.82%. It showed weak ferric-reducing power with a EC50 value of 0.65 when compared to BHT (EC50 = 0.2). Also, at 0.5 mg/ml concentration, the methanolic extract inhibited ABTS radical cation activity with an inhibition of 20.13% when compared to Trolox (79.01%). Chelating ability of G. brachyphylla was 44.71% whereas EDTA showed 78.87% chelating activity at 0.2 mg/ml. Also G. brachyphylla showed weak 27.21% AChE, 20.23% BChE, strong 67.86% MAO-A and moderate 50.06% MAO-B, weak 19.14% COX-1, 29.11% COX-2 inhibitory activities at 0.25 mg/ml. The total phenolic content of G. brachyphylla was 156.23 ± 2.73 mg gallic acid equivalent/100 g extract.Keywords: antioxidant activity, cholinesterase inhibitory activity, Gentiana brachyphylla Vill., total phenolic content
Procedia PDF Downloads 2011076 Atomic Absorption Spectroscopic Analysis of Heavy Metals in Cancerous Breast Tissues among Women in Jos, Nigeria
Authors: Opeyemi Peter Idowu
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Breast cancer is prevalent in northern Nigerian women, most especially in Jos, Plateau State, owing to anthropogenic activities such as solid earth mineral mining as far back as 1904. In this study, atomic absorption spectrometry was used to determine the concentration of eight heavy metals (Cd, As, Cr, Cu, Fe, Pb, Ni, and Zn) in cancerous and non-cancerous breast tissues of Jos Nigerian Women. The levels of heavy metals ranged from 1.08 to 29.34 mg/kg, 0.29 to 10.76 mg/kg, 0.35 to 51.93 mg/kg, 5.15 to 62.93 mg/kg, 11.64 to 51.10 mg/kg, 0.42 to 83.16 mg/kg, 2.08 to 43.07 mg/kg and 1.67 to 71.53 mg/kg for Cd, As, Cr, Cu, Fe, Pb, Ni and Zn respectively. Using MATLAB R2016a, significant differences (tᵥ = 0.0041 - 0.0317) existed between the levels of all the heavy metals in cancerous and non-cancerous breast tissues except Fe. At 0.01 level of significance, a positive significant correlation existed between Pb and Fe, Pb and Cu, Pb and Fe, Ni and Fe, Cr and Pb, as well as Ni and Cr (r = 0.583 – 0.998) in cancerous breast tissues. Using ANOVA, significant differences also occurred in the levels of these heavy metals in cancerous breast tissues (p = 1.910510×10⁻²⁶). The relatively high levels of the cancer-induced heavy metals (Cd, As, Cr, and Pb) compared with control indicated contamination or exposure to heavy metals, which could be the major cause of cancer in these female subjects. This was evidence of contamination as a result of exposure by ingestion, inhalation, or other means to one anthropogenic activity of the other. Therapeutic measures such as gastric lavage, ascorbic acid consumption, and divalent cation treatment are all effective ways to manage heavy metal toxicity in the subjects to lower the risk of breast cancer.Keywords: breast cancer, heavy metals, spectroscopy, bio-accumulation
Procedia PDF Downloads 261075 Simultaneous Removal of Arsenic and Toxic Metals from Contaminated Soil: a Pilot-Scale Demonstration
Authors: Juan Francisco Morales Arteaga, Simon Gluhar, Anela Kaurin, Domen Lestan
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Contaminated soils are recognized as one of the most pressing global environmental problems. As is one of the most hazardous elements: chronic exposure to arsenic has devastating effects on health, cardiovascular diseases, cancer, and eventually death. Pb, Zn and Cd are very highly toxic metals that affect almost every organ in the body. With this in mind, new technologies for soil remediation processes are urgently needed. Calcareous artificially contaminated soil containing 231 mg kg-1 As and historically contaminated with Pb, Zn and Cd was washed with a 1:1.5 solid-liquid ratio of 90 mM EDTA, 100 mM oxalic acid, and 50 mM sodium dithionite to remove 59, 75, 29, and 53% of As, Pb, Zn, and Cd, respectively. To reduce emissions of residual EDTA and chelated metals from the remediated soil, zero valent iron (ZVI) was added (1% w/w) to the slurry of the washed soil immediately prior to rinsing. Experimental controls were conducted without the addition of ZVI after remediation. The use of ZVI reduced metal leachability and minimized toxic emissions 21 days after remediation. After this time, NH4NO3 extraction was performed to determine the mobility of toxic elements in the soil. In addition, Unified Human BioaccessibilityMethod (UBM) was performed to quantify the bioaccessibility levels of metals in stimulated human gastric and gastrointestinal phases.Keywords: soil remediation, soil science, soil washing, toxic metals removal
Procedia PDF Downloads 1751074 Carbonate Crusts in Jordan: Records of Groundwater Flow, Carbon Fluxes, Tectonic Movement and Climate Change
Authors: Nizar Abu-Jaber
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Late Pleistocene and Holocene carbonate crusts in the south of Jordan were studied using a combination of field documentation, petrography, geochemical and isotopic techniques. These surficial crusts and vein deposits appear to have formed as a result of interaction between near-surface groundwater, surficial soil and sediments and rising carbon dioxide. Rising mantle CO2 dissolves in the water to create carbonic acid, which in turn dissolves the calcite in the soil in the sediments. When the pH rises later due to degassing, the carbonate crusts are left in the places where the water was flowing in veins, channels and interfaces between high and low permeability materials. The crusts have the potential for being important records of natural and human agencies on the landscape of the area. They reflect the isotopic composition of the waters in which they precipitated in, and also contain isotopic information about the aeolian calcium fluxes affecting the area (using strontium isotopes). Moreover, changing stream valley base levels can be identified and measured, which can help quantify the rates of tectonic movement. Finally, human activities such and channel construction and terrace building can be identified and traced temporally and spatially using these deposits.Keywords: anthropogenic change, carbonate crusts, environmental change, Jordan
Procedia PDF Downloads 2791073 Plasmonic Biosensor for Early Detection of Environmental DNA (eDNA) Combined with Enzyme Amplification
Authors: Monisha Elumalai, Joana Guerreiro, Joana Carvalho, Marta Prado
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DNA biosensors popularity has been increasing over the past few years. Traditional analytical techniques tend to require complex steps and expensive equipment however DNA biosensors have the advantage of getting simple, fast and economic. Additionally, the combination of DNA biosensors with nanomaterials offers the opportunity to improve the selectivity, sensitivity and the overall performance of the devices. DNA biosensors are based on oligonucleotides as sensing elements. These oligonucleotides are highly specific to complementary DNA sequences resulting in the hybridization of the strands. DNA biosensors are not only an advantage in the clinical field but also applicable in numerous research areas such as food analysis or environmental control. Zebra Mussels (ZM), Dreissena polymorpha are invasive species responsible for enormous negative impacts on the environment and ecosystems. Generally, the detection of ZM is made when the observation of adult or macroscopic larvae's is made however at this stage is too late to avoid the harmful effects. Therefore, there is a need to develop an analytical tool for the early detection of ZM. Here, we present a portable plasmonic biosensor for the detection of environmental DNA (eDNA) released to the environment from this invasive species. The plasmonic DNA biosensor combines gold nanoparticles, as transducer elements, due to their great optical properties and high sensitivity. The detection strategy is based on the immobilization of a short base pair DNA sequence on the nanoparticles surface followed by specific hybridization in the presence of a complementary target DNA. The hybridization events are tracked by the optical response provided by the nanospheres and their surrounding environment. The identification of the DNA sequences (synthetic target and probes) to detect Zebra mussel were designed by using Geneious software in order to maximize the specificity. Moreover, to increase the optical response enzyme amplification of DNA might be used. The gold nanospheres were synthesized and characterized by UV-visible spectrophotometry and transmission electron microscopy (TEM). The obtained nanospheres present the maximum localized surface plasmon resonance (LSPR) peak position are found to be around 519 nm and a diameter of 17nm. The DNA probes modified with a sulfur group at one end of the sequence were then loaded on the gold nanospheres at different ionic strengths and DNA probe concentrations. The optimal DNA probe loading will be selected based on the stability of the optical signal followed by the hybridization study. Hybridization process leads to either nanoparticle dispersion or aggregation based on the presence or absence of the target DNA. Finally, this detection system will be integrated into an optical sensing platform. Considering that the developed device will be used in the field, it should fulfill the inexpensive and portability requirements. The sensing devices based on specific DNA detection holds great potential and can be exploited for sensing applications in-loco.Keywords: ZM DNA, DNA probes, nicking enzyme, gold nanoparticles
Procedia PDF Downloads 2451072 Curcumin and Methotrexate Loaded Montmollilite Clay for Sustained Oral Drug Delivery Application
Authors: Subrata Kar, Banani Kundu, Papiya Nandy, Ruma Basu, Sukhen Das
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Natural montmorilollite clay is a common ingredient in pharmaceutical products, both as excipients and active support; hence considered as suitable candidate for Drug Delivery System. In this work, cationic detergent CTAB is used to increase the interlayer spacing of Na+-Montmoriollite clay to intercalate curcumin and methotrexate. Methotrexate is a folic acid antagonist, anti-proliferative and immunosuppressive agent; while curcumin is a bioactive constituent of rhizomes of Curcuma longa, possessing remarkable chemo-preventive and anti-inflammatory properties. The resultant inorganic-organic hybrids are characterized by X-ray diffraction (XRD), Infrared spectroscopy (FTIR) and Thermo Gravimetric Analysis (TGA) to confirm successful intercalation of curcumin and Methotrexate within clay layers. Pharmaceutical investigation of the hybrids is explored by studying the drug loading (%), encapsulation efficiency and release kinetics. Finally in-vitro studies are performed using cancer cells to find the effect of released curcumin to improve the sensitivity of clay bound methotrexate to ameliorate cell death compared to their effectiveness when used without the inorganic aluminosilicate vehicle.Keywords: montmorillonite, methotrexate, curcumin, loading efficiency, release kinetics, anticancer activity
Procedia PDF Downloads 5151071 TiO2/Clay Minerals (Palygorskite/Halloysite) Nanocomposite Coatings for Water Disinfection
Authors: Dionisios Panagiotaras, Dimitrios Papoulis, Elias Stathatos
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Microfibrous palygorskite and tubular halloysite clay mineral combined with nanocrystalline TiO2 are incorporating in the preparation of nanocomposite films on glass substrates via sol-gel route at 450 °C. The synthesis is employing nonionic surfactant molecule as pore directing agent along with acetic acid-based sol-gel route without addition of water molecules. Drying and thermal treatment of composite films ensure elimination of organic material lead to the formation of TiO2 nanoparticles homogeneously distributed on the palygorskite or halloysite surfaces. Nanocomposite films without cracks of active anatase crystal phase on palygorskite and halloysite surfaces are characterized by microscopy techniques, UV-Vis spectroscopy, and porosimetry methods in order to examine their structural properties. The composite palygorskite-TiO2 and halloysite-TiO2 films with variable quantities of palygorskite and halloysite were tested as photocatalysts in the photo-oxidation of Basic Blue 41 azo dye in water. These nanocomposite films proved to be most promising photocatalysts and highly effective to dye’s decoloration in spite of small amount of palygorskite -TiO2 or halloysite- TiO2 catalyst immobilized onto glass substrates mainly due to the high surface area and uniform distribution of TiO2 on clay minerals avoiding aggregation.Keywords: halloysite, palygorskite, photocatalysis, titanium dioxide
Procedia PDF Downloads 3151070 Preparation and Characterization of Modified ZnO Incorporated into Mesoporous MCM-22 Catalysts and Their Catalytic Performances of Crude Jatropha Oil to Biodiesel
Authors: Bashir Abubakar Abdulkadir, Anita Ramli, Lim Jun Wei, Yoshimitsu Uemura
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In this study, the ZnO/MCM-22 catalyst with different ZnO loading were prepared using conventional wet impregnation process and the catalyst activity was tested for biodiesel production from Jatropha oil. The effects of reaction parameters with regards to catalyst activity were investigated. The synthesized catalysts samples were then characterized by X-ray diffraction (XRD) for crystal phase, Brunauer–Emmett–Teller (BET) for surface area, pore volume and pore size, Field Emission Scanning electron microscope attached to energy dispersive x-ray (FESEM/EDX) for morphology and elemental composition and TPD (NH3 and CO2) for basic and acidic properties of the catalyst. The XRD spectra couple with the EDX result shows the presence of ZnO in the catalyst confirming the positive intercalation of the metal oxide into the mesoporous MCM-22. The synthesized catalyst was confirmed to be mesoporous according to BET findings. Also, the catalysts can be considered as a bifunctional catalyst based on TPD outcomes. Transesterification results showed that the synthesized catalyst was highly efficient and effective to be used for biodiesel production from low grade oil such as Jatropha oil and other industrial application where the high fatty acid methyl ester (FAMEs) yield was achieved at moderate reaction conditions. It was also discovered that the catalyst can be used more than five (5) runs with little deactivation confirming the catalyst to be highly active and stable to the heat of reaction.Keywords: MCM-22, synthesis, transesterification, ZnO
Procedia PDF Downloads 2081069 Development of Calcium Carbonate Molecular Sheets via Wet Chemical Route
Authors: Sudhir Kumar Sharma, Ramesh Jagannathan
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The interaction of organic and inorganic matrices of biological origin resulting in self-assembled structures with unique properties is well established. The development of such self-assembled nanostructures by synthetic and bio-inspired techniques is an established field of active research. Among bio-materials, nacre, a laminar stack of calcium carbonate nanosheets, which are interleaved with organic material, has long been focused research due to its unique mechanical properties. In this paper, we present the development of nacre-like lamellar structures made up of calcium carbonate via a wet chemical route. We used the binding affinity of carboxylate anions and calcium cations using poly (acrylic) acid (PAA) to lead CaCO₃ crystallization. In these experiments, we selected calcium acetate as the precursor molecule along with PAA (Mw ~ 8000 Da). We found that Ca⁺²/COO⁻ ratio provided a tunable control for the morphology and growth of CaCO₃ nanostructures. Drop casting one such formulation on a silicon substrate followed by calcination resulted in co-planner, molecular sheets of CaCO₃, separated by a spacer layer of carbon. The scope of our process could be expanded to produce unit cell thick molecular sheets of other important inorganic materials.Keywords: self-assembled structures, bio-inspired materials, calcium carbonate, wet chemical route
Procedia PDF Downloads 1361068 The Extraction and Stripping of Hg(II) from Produced Water via Hollow Fiber Contactor
Authors: Dolapop Sribudda, Ura Pancharoen
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The separation of Hg(II) from produced water by hollow fiber contactors (HFC) was investigation. This system included of two hollow fiber modules in the series connecting. The first module used for the extraction reaction and the second module for stripping reaction. Aliquat336 extractant was fed from the organic reservoirs into the shell side of the first hollow fiber module and continuous to the shell side of the second module. The organic liquid was continuously feed recirculate and back to the reservoirs. The feed solution was pumped into the lumen (tube side) of the first hollow fiber module. Simultaneously, the stripping solution was pumped in the same way in tube side of the second module. The feed and stripping solution was fed which had a counter current flow. Samples were kept in the outlet of feed and stripping solution for 1 hour and characterized concentration of Hg(II) by Inductively Couple Plasma Atomic Emission Spectroscopy (ICP-AES). Feed solution was produced water from natural gulf of Thailand. The extractant was Aliquat336 dissolved in kerosene diluent. Stripping solution used was nitric acid (HNO3) and thiourea (NH2CSNH2). The effect of carrier concentration and type of stripping solution were investigated. Results showed that the best condition were 10 % (v/v) Aliquat336 and 1.0 M NH2CSNH2. At the optimum condition, the extraction and stripping of Hg(II) were 98% and 44.2%, respectively.Keywords: Hg(II), hollow fiber contactor, produced water, wastewater treatment
Procedia PDF Downloads 4031067 Correlation between Total Polyphenol Content and Antimicrobial Activity of Opuntia ficus indica Extracts against Periodontopathogenic Bacteria
Authors: N. Chikhi-Chorfi, L. Arbia, S. Zenia, H.Lounici
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Opuntia ficus-indica belongs to the Cactaceae family. The cactus is mainly cultivated for its fruit (prickly pear) that, eaten after pealing, is sweet and juicy, and rich in nutritional compounds, such as ascorbic acid and polyphenols. Different parts of O. ficus-indica are used in the traditional medicine of several countries: the cladodes are utilized to reduce serum cholesterol level and blood pressure, for treatment of ulcers, rheumatic pain, wounds, fatigue, capillary fragility, and liver conditions. This original study, investigate the effect of polyphenols of O. ficus indica (cactus) cladodes against periodontal bacteria collected from patients with periodontitis. The quantitative analysis of total polyphenols (TPP) was determined with Follin-Ciocalteu method. Different concentrations of extracts of O. ficus indica were tested by the disk method on two bacterial strains: Porphyromonas gingivalis and Prevotella intermedia responsible for periodontal disease. The results showed a good correlation between the concentration of total polyphenols and the antibacterial activity of the extracts of Opuntia ficus indica against P. gingivalis and P. intermedia with R² = 0.94 and R² = 0.90 respectively. This observation suggests that these extracts could be used in the treatment and prevention of periodontitis.Keywords: periodontal disease, P. gingivalis, P. intermedia, polyphenols, Opuntia ficus indica
Procedia PDF Downloads 1461066 Design and Characterization of Aromatase Inhibitor Loaded Nanoparticles for the Treatment of Breast Cancer
Authors: Harish K. Chandrawanshi, Mithun S. Rajput, Neelima Choure, Purnima Dey Sarkar, Shailesh Jain
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The present research study aimed to fabricate and evaluate biodegradable nanoparticles of aromatase inhibitor letrozole, intended for breast cancer therapy. Letrozole loaded poly(D,L-lactide-co-glycolide acid) nanoparticles were prepared by solvent evaporation method using dichlorometane as solvent (oil phase) and polyvinyl alcohol (PVA) as aqueous phase. Prepared nanoparticles were characterized by particle size, infrared spectra, drug loading efficiency, drug entrapment efficiency and in vitro release and also evaluated for in vivo anticancer activity. The high speed homogenizer was used to produce stable nanoparticles of mean size range 198.35 ± 0.04 nm with high entrapment efficiency (69.86 ± 2.78%). Percentage of drug and homogenization speed significantly influenced the particle size, entrapment efficiency and release (p<0.05). The nanoparticles show significant in vivo anticancer activity against Ehrlich ascites carcinoma in mice. The significant system sustained the release of letrozole drug effectively and further investigation could exhibit its potential usefulness in breast cancer therapy.Keywords: breast cancer/therapy, letrozole, nanoparticles, PLGA
Procedia PDF Downloads 5801065 Increasing Redness and Microbial Stability of Low Nitrite Chicken Sausage by Encapsulated Tomato Pomace Extract
Authors: Bung-Orn Hemung, Nachayut Chanshotigul, Koo Bok Chin
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Tomato pomace (TP) is the waste from tomato processing plants and its utilization as food ingredient may provide sustainable industry by reducing waste. TP was extracted by ethanol using microwave-assisted method at 180W for 90s. The ethanol was evaporated out, and an extract was encapsulated with maltodextrin (1:10) by spray drying to obtain an encapsulated TP extract (ETPE). The redness (a value) of ETPE powder was 6.5±0.05, and it was used as natural ingredient in the low-nitrite chicken sausage. Chicken emulsion sausage was prepared at 25 mg/kg of nitrite for being control. Effect of ETPE (1.0%) was evaluated along with the reference (150 mg/kg of nitrite without ETPE). The redness (a value) of sausage with ETPE was found at 6.8±0.03, which was higher than those of reference and control, which were at 4.8±.022 and 5.1±0.15, respectively. However, hardness, expressible moisture content and cooking yield values were reduced slightly. During storage at 10 °C in the air packed condition for 1 week, changes in color, pH, redness, and thiobarbituric acid reactive substances value were not significantly different. However, total microbial count of sausage samples with ETPE was lower than control for a 1 log cycle, suggesting microbial stability. Therefore, the addition of ETPE could be an alternative strategy to utilize TP as a natural colorant and antimicrobial agent to extend the shelf life of low-nitrite chicken sausage.Keywords: antimicrobial ingredient, chicken sausage, ethanolic extract, low-nitrite sausage, tomato pomace
Procedia PDF Downloads 2081064 Disease Control of Rice Blast Caused by Pyricularia Oryzae Cavara Using Novel Chitosan-based Agronanofungicides
Authors: Abdulaziz Bashir Kutawa, Khairulmazmi Ahmad, Mohd Zobir Hussein, Asgar Ali, Mohd Aswad Abdul Wahab, Amara Rafi, Mahesh Tiran Gunasena, Muhammad Ziaur Rahman, Md. Imam Hossain, Syazwan Afif Mohd Zobir
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Rice is a cereal crop and belongs to the family Poaceae, it was domesticated in southern China and North-Eastern India around 8000 years ago, and it’s the staple nourishment for over half of the total world’s population. Rice production worldwide is affected by different abiotic and biotic stresses. Diseases are important challenges for the production of rice, among all the diseases in rice plants, the most severe and common disease is the rice blast. Worldwide, it is one of the most damaging diseases affecting rice cultivation, the disease is caused by the non-obligate filamentous ascomycete fungus called Magnaporthe grisae or Pyricularia oryzae Cav. Nanotechnology is a new idea to improve agriculture by combating the diseases of plants, as nanoparticles were found to possess an inhibitory effect on different species of fungi. This work aimed to develop and determine the efficacy of agronanofungicides, and commercial fungicides (in-vitro and in-vivo). The agronanofungicides were developed using ionic gelation methods. In-vitro antifungal activity of the synthesized agronanofungicides was evaluated against P. oryzae using the poisoned medium technique. The potato dextrose agar (PDA) was amended in several concentrations; 0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.15, 0.20, 0.25, 0.30, and 0.35 ppm for the agronanofungicides. Medium with the only solvent served as a control. Mycelial growth was recorded every day, and the percentage inhibition of radial growth (PIRG) was also calculated. Based on the results of the zone of inhibition, the chitosan-hexaconazole agronanofungicide (2g/mL) was the most effective fungicide to inhibit the growth of the fungus with 100% inhibition at 0.2, 0.25, 0.30, and 0.35 ppm, respectively. The least were found to be propiconazole and basamid fungicides with 100% inhibition only at 100 ppm. In terms of the glasshouse results, the chitosan-hexaconazole-dazomet agronanofungicide (CHDEN) treatment (2.5g/L) was found to be the most effective fungicide to reduce the intensity of the disease with a disease severity index (DSI) of 19.80%, protection index (PI) of 82.26%, lesion length of 1.63cm, disease reduction (DR) of 80.20%, and AUDPC (390.60 Unit2). The least effective fungicide was found to be ANV with a disease severity index (45.60%), protection index (45.24%), lesion length (3.83 cm), disease reduction (54.40%), and AUDPC (1205.75 Unit2). The negative control did not show any symptoms during the glasshouse assay, while the untreated control treatment exhibited severe symptoms of the disease with a DSI value of 64.38%, lesion length of 5.20 cm, and AUDPC value of 2201.85 Unit2, respectively. The treatments of agronanofungicides have enhanced the yield significantly with CHDEN having 239.00 while the healthy control had 113.67 for the number of grains per panicle. The use of CHEN and CHDEN will help immensely in reducing the severity of rice blast in the fields, and this will increase the yield and profit of the farmers that produced rice.Keywords: chitosan, dazomet, disease severity, efficacy, and blast disease
Procedia PDF Downloads 871063 Structural and Histochemical Alterations in the Development of the Stigma in Vibirnum tinus
Authors: Aslihan Cetinbas Genc, Meral Unal
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This study presents the structural and cytochemical alterations of stigma at the stages of pre-anthesis, anthesis and post-anthesis in Vibirnum tinus. Capitate stigma continues with a closed style. The receptive surface of stigma is composed of unicellular papillae which are short and flattened at pre-anthesis stage. The papillae in this stage have dense cytoplasm with small vacuoles and a centrally located nucleus. With the start of anthesis, the stigma widens, papillae lengthen and become cylindrical. At anthesis stage, vacuoles enlarge, and nucleus moves to the base of the cell. At post-anthesis stage, the boundaries of the papillae become less noticeable. As proved by Periodic Acid Schiff procedure, the cytoplasm of papillae is rich in insoluble polysaccharides at all stages of development but it becomes remarkable at post-anthesis, particularly at the sub-papillar area. Although there is no significant difference in the content of protein in all stages of the development, it is more abundant at post-anthesis stage, as in Coomassie Brillant Blue stained sections. The surface of papillae is covered by a cuticle which becomes thicker at post-anthesis, and it gives positive reaction with Sudan Black B and Auramine O. The cuticle is covered by a pellicle stained by Coomassie Brillant Blue, indicating dry type of stigma.Keywords: develeopmental features, histochemistry, stigma, Vibirnum tinus
Procedia PDF Downloads 2471062 Immunoprotective Role of Baker's Yeast (Saccharomyces cerevisiae) against Experimentally Induced Aflatoxicosis in Broiler Chicks
Authors: Zain Ul Abadeen, Muhammad Zargham Khan, Muhammad Kashif Saleemi, Ahrar Khan, Ijaz Javed Hassan, Aisha Khatoon, Qasim Altaf
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Aflatoxins are secondary metabolites produced by toxigenic fungi, and there are four types of aflatoxins include AFB1, AFB2, AFG1 and AFG2. Aflatoxin B1 (AFB1) is considered as most toxic form. It is mainly responsible for the contamination of poultry feed and produces a condition called aflatoxicosis leads to immunosuppression in poultry birds. Saccharomyces cerevisiae is a single cell microorganism and acts as a source of growth factors, minerals and amino acids which improve the immunity and digestibility in poultry birds as probiotics. Saccharomyces cerevisiae is well recognized to cause the biological degradation of mycotoxins (toxin binder) because its cell wall contains β-glucans and mannans which specifically bind with aflatoxins and reduce their absorption or transfer them to some non-toxic compounds. The present study was designed to investigate the immunosuppressive effects of aflatoxins in broiler chicks and the reduction of severity of these effects by the use of Baker’s Yeast (Saccharomyces cerevisiae). One-day-old broiler chicks were procured from local hatchery and were divided into various groups (A-I). These groups were treated with different levels of AFB1 @ 400 µg/kg and 600 µg/kg along with different levels of Baker’s Yeast (Saccharomyces cerevisiae) 0.1% and 0.5 % in the feed. The total duration of the experiment was six weeks and different immunological parameters including the cellular immune response by injecting PHA-P (Phytohemagglutinin-P) in the skin of the birds, phagocytic function of mononuclear cells by Carbon clearance assay from blood samples and humoral immune response against intravenously injected sheep RBCs from the serum samples were determined. The birds from each group were slaughtered at the end of the experiment to determine the presence of gross lesions in the immune organs and these tissues were fixed in 10% neutral buffered formalin for histological investigations. The results showed that AFB1 intoxicated groups had reduced body weight gain, feed intake, organs weight and immunological responses compared to the control and Baker’s Yeast (Saccharomyces cerevisiae) treated groups. Different gross and histological degenerative changes were recorded in the immune organs of AFB1 intoxicated groups compared to control and Baker’s Yeast (Saccharomyces cerevisiae) treated groups. The present study concluded that Baker’s Yeast (Saccharomyces cerevisiae) addition in the feed helps to ameliorate the immunotoxigenic effects produced by AFB1 in broiler chicks.Keywords: aflatoxins, body weight gain, feed intake, immunological response, toxigenic effect
Procedia PDF Downloads 3121061 Randomly Casted Single-Wall Carbon Nanotubes Films for High Performance Hybrid Photovoltaic Devices
Authors: My Ali El Khakani
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Single-wall Carbon nanotubes (SWCNTs) possess an unprecedented combination of unique properties that make them highly promising for suitable for a new generation of photovoltaic (PV) devices. Prior to discussing the integration of SWCNTs films into effective PV devices, we will briefly highlight our work on the synthesis of SWCNTs by means of the KrF pulsed laser deposition technique, their purification and transfer onto n-silicon substrates to form p-n junctions. Some of the structural and optoelectronic properties of SWCNTs relevant to PV applications will be emphasized. By varying the SWCNTs film density (µg/cm2), we were able to point out the existence of an optimum value that yields the highest photoconversion efficiency (PCE) of ~10%. Further control of the doping of the p-SWCNTs films, through their exposure to nitric acid vapors, along with the insertion of an optimized hole-extraction-layer in the p-SWCNTs/n-Si hybrid devices permitted to achieve a PCE value as high as 14.2%. Such a high PCE value demonstrates the full potential of these p-SWCNTs/n-Si devices for sunlight photoconversion. On the other hand, by examining both the optical transmission and electrical conductance of the SWCNTs’ films, we established a figure of merit (FOM) that was shown to correlate well with the PCE performance. Such a direct relationship between the FOM and the PCE can be used as a guide for further PCE enhancement of these novel p-SWCNTs/n-Si PV devices.Keywords: carbon nanotubes (CNTs), CNTs-silicon hybrid devices, photoconversion, photovoltaic devices, pulsed laser deposition
Procedia PDF Downloads 1181060 The Relation between Vitamin C and Oral Health
Authors: Mai Ashraf Talaat
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Background: Vitamin C (ascorbic acid) is an essential nutrient for the development and repair of all body tissues. It can be obtained from a healthy diet or through supplementation. Due to its importance, vitamin C has become a mainstay in the treatment and prevention of many diseases and in maintaining immune, skin, bone and overall health. This review article aims to discuss the studies and case reports conducted to evaluate the effect of Vitamin C on oral health and the recent advances in oral medicine that involve the use of vitamin C. Data/Sources: The review was conducted for clinical studies, case reports and published literature in the English language that addresses this topic. An extensive search in the electronic databases of PubMed, PubMed Central, Web of Science, National Library of Medicine and ResearchGate was performed. Conclusion: Vitamin C is thought to treat periodontal diseases and gingival enlargement. It also affects biofilm formation and therefore, it helps in reducing caries incidence. Recently, vitamin C mesotherapy has been used to treat inflamed gingiva, bleeding gums and gingival hyperpigmentation. More research and randomized controlled trials are needed on this specific topic for more accurate judgment. Clinical significance: A minimally invasive approach - the usage of vitamin C in dental care could drastically reduce the need for surgical intervention.Keywords: oral health, periodontology, vitamin C, Gingivitis
Procedia PDF Downloads 781059 Removal of Pb(II) Ions from Wastewater Using Magnetic Chitosan–Ethylene Glycol Diglycidyl Ether Beads as Adsorbent
Authors: Pyar Singh Jassal, Priti Rani, Rajni Johar
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The adsorption of Pb(II) ions from wastewater using ethylene glycol diglycidyl ether cross-linked magnetic chitosan beads (EGDE-MCB) was carried out by considering a number of parameters. The removal efficiency of the metal ion by magnetic chitosan beads (MCB) and its cross-linked derivatives depended on viz contact time, dose of the adsorbent, pH, temperature, etc. The concentration of Cd( II) at different time intervals was estimated by differential pulse anodic stripping voltammetry (DPSAV) using 797 voltametric analyzer computrace. The adsorption data could be well interpreted by Langmuir and Freundlich adsorption model. The equilibrium parameter, RL values, support that the adsorption (01058 Pro-Ecological Antioxidants for Polymeric Composites
Authors: Masek A., Zaborski M.
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In our studies, we propose the use of natural, pro-ecological substances such as polyphenols to protect polymers against ageing. In our studies, we plan to focus on the following compounds: polyphenols, gallic acid esters, flavonoides, carotenoids, curcumin and its derivatives, vitamin A, tocochromanoles, betalain. Phyto-compounds will be selected on the basis of available literature and our preliminary studies. So, we will select compounds with various contents of hydroxyl groups and colored substances capable of participating in color oxidation processes. The natural antioxidants which were added to ethylene-octene elastomer (polyolefin elastomer-Engage) and ethylene-nonbornene (TOPAS). Composites were then subjected to numerous ageing: weathering (climat of Floryda), UV (0,7 W/m2), thermo-oxidation ageing (1000C/10days) and thermal-shock (-600C/+1000C) as a function of the aging time. The efficiency of used anti-ageing agents was checked on the base of the changes after the degradation in deformation energy (tensile strength and elongation at the break), cross-link density, color (parameters L,a,b) and values of carbonyl index (based on the spectrum of infra red spectroscopy), OIT (induction oxygen time as performed in using differential scanning calorimeter -DSC) of the vulcanizates. Therefore polyphenols are considered to be the best stabilisers for polymeric composites against to oxidation processes.Keywords: polymers, flavonoids, stabilization, ageing, oxidation
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