Antioxidants

20 pages, 893 KB

Open AccessArticle

Bioactive Compounds and Antioxidant Activity in Different Grafted Varieties of Bell Pepper

by Celia Chávez-Mendoza, Esteban Sanchez, Ezequiel Muñoz-Marquez, Juan Pedro Sida-Arreola and Maria Antonia Flores-Cordova

Antioxidants 2015, 4(2), 427-446; https://doi.org/10.3390/antiox4020427 - 23 Jun 2015

Cited by 93 | Viewed by 15292

Abstract

Grafting favors the presence of bioactive compounds in the bell pepper, but many species and varieties have not yet been analyzed in this sense, including commonly grafted varieties. The aim of the present study is to characterize the content in β-carotenes, vitamin C, [...] Read more.

Grafting favors the presence of bioactive compounds in the bell pepper, but many species and varieties have not yet been analyzed in this sense, including commonly grafted varieties. The aim of the present study is to characterize the content in β-carotenes, vitamin C, lycopene, total phenols, and the antioxidant activity of bell pepper (Capsicum annum L.) using the cultivar/rootstock combinations: Jeanette/Terrano (yellow), Sweet/Robusto (green), Fascinato/Robusto (red), Orangela/Terrano (orange), and Fascinato/Terrano (red). The plants were grown in a net-shading system and harvested on three sampling dates of the same crop cycle. The results show statistical differences (p ≤ 0.05) between cultivar/rootstock combinations and sampling dates for the content in bioactive compounds and antioxidant activity. Fascinato/Robusto presented the highest concentration of lycopene and total phenols as well as the greatest antioxidant activity of all cultivar/rootstock combinations evaluated. In addition, it was found that the best sampling time for the peppers to have the highest concentrations of bioactive compounds and antioxidant activity was September. Full article

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17 pages, 535 KB

Open AccessArticle

Study of Polyphenol Content and Antioxidant Capacity of Myrianthus Arboreus (Cecropiaceae) Root Bark Extracts

by Pierre Betu Kasangana, Pierre Selim Haddad and Tatjana Stevanovic

Antioxidants 2015, 4(2), 410-426; https://doi.org/10.3390/antiox4020410 - 9 Jun 2015

Cited by 80 | Viewed by 9068

Abstract

In order to evaluate the therapeutic potential of polyphenolic extracts from root bark of M. arboreus, we have determined the content of various polyphenols in aqueous and ethanol (EtOH) extract as well as two sub-fractions of the latter: ethyl acetate (EAc) and [...] Read more.

In order to evaluate the therapeutic potential of polyphenolic extracts from root bark of M. arboreus, we have determined the content of various polyphenols in aqueous and ethanol (EtOH) extract as well as two sub-fractions of the latter: ethyl acetate (EAc) and hexane (Hex). The total phenols, flavonoids, hydroxycinnamic acids and proanthocyanidins have been determined for all studied extracts/fractions by spectrophotometric methods. Both TP content (331.5 ± 2.5 mg GAE/g) and HCA content (201 ± 1.5 mg CAE/g) were determined to be the highest in EAc fraction of EtOH extract. All studied extracts were however determined to have a low content in flavonoids. The determination of antioxidant capacities of the studied extracts has also been performed by the following in vitro antioxidant tests: DPPH scavenging, phosphomolybdenum method and oxygen radical absorbance (ORAC_Fl and ORAC_PRG) assay. The results of the DPPH free radical and ORAC_Fl assays showed that there is no significant difference between the EAc fraction and Oligopin^®, but the EAc fraction exhibited the highest antioxidant capacity as determined by the phosphomolybdenium method. In addition, the EtOH extract was determined to have the same antioxidant efficiency as the synthetic antioxidant BHT or commercial extract Oligopin^® by phosphomolybdenum method. On the other hand, a positive correlation (r < 0.6) was found between different classes of polyphenols and the results of the phosphomolybdenum method, ORAC_Fl as well as ORAC_PRG_, except for the DPPH assay, for which a negative correlation was indicated (r < 0.62). Interestingly, it seems that the content in hydroxycinnamic acids played a big role in all assays with r < 0.9. According to the present study, EAc fraction and EtOH extract should be further studied for the potential use in the pharmaceutical and food industry. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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16 pages, 741 KB

Open AccessArticle

Comparative Analysis of Phenolics, Flavonoids, and Antioxidant and Antibacterial Potential of Methanolic, Hexanic and Aqueous Extracts from Adiantum caudatum Leaves

by Dildar Ahmed, Muhammad Mehboob Khan and Ramsha Saeed

Antioxidants 2015, 4(2), 394-409; https://doi.org/10.3390/antiox4020394 - 4 Jun 2015

Cited by 196 | Viewed by 15178

Abstract

In the quest for new medicines, the methanolic, hexanic, and aqueous extracts of Adiantum caudatum leaves, obtained by Soxhlet extraction, were analyzed for phenolic and flavonoid contents, and antioxidant and antimicrobial potential. TPCs (total phenolic content) of the methanolic, aqueous and hexanic extracts [...] Read more.

In the quest for new medicines, the methanolic, hexanic, and aqueous extracts of Adiantum caudatum leaves, obtained by Soxhlet extraction, were analyzed for phenolic and flavonoid contents, and antioxidant and antimicrobial potential. TPCs (total phenolic content) of the methanolic, aqueous and hexanic extracts were 27.7, 21.1, and 16.7 μg of gallic acid equivalents per mL, respectively, while TFCs (total flavonoid content) were 13.2, 11.6, and 10.0 μg of rutin equivalents per mL, respectively. Antioxidant activities of the extracts in reducing power, FRAP (ferric reducing antioxidant power), phosphomolybdate and ABTS assays follow the same order of methanolic ˃ aqueous ˃ hexanic. In the DPPH assay, however, the aqueous extract exhibited a slightly higher antioxidant activity than the methanolic one. Methanol is therefore a better solvent to extract most of the antioxidant components from A. caudatum leaves. In lipid peroxidation inhibitory assay, the extracts showed almost similar behavior and their activity decreased gradually with time. The aqueous extract was the strongest inhibitor after two days, but the hexanic became the most potent after about three days. The antibacterial potential of the extracts was determined against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Towards all the microbes, the aqueous extract was the most potent and the hexanic the least. P. aeruginosa was the most susceptible strain, while the aqueous and methanolic extracts exhibited a slightly higher efficacy against this pathogen than the drug amoxicillin. In conclusion, A. caudatum can potentially provide a remedy against disorders caused by oxidative stress and infections. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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21 pages, 387 KB

Open AccessArticle

Food Inhibits the Oral Bioavailability of the Major Green Tea Antioxidant Epigallocatechin Gallate in Humans

by Nenad Naumovski, Barbara L. Blades and Paul D. Roach

Antioxidants 2015, 4(2), 373-393; https://doi.org/10.3390/antiox4020373 - 27 May 2015

Cited by 93 | Viewed by 21800

Abstract

The bioavailability of the most abundant and most active green tea antioxidant, epigallocatechin gallate (EGCG) remains uncertain. Therefore, the systemic absorption of EGCG was tested in healthy fasted humans. It was administered as capsules with water or with a light breakfast, or when [...] Read more.

The bioavailability of the most abundant and most active green tea antioxidant, epigallocatechin gallate (EGCG) remains uncertain. Therefore, the systemic absorption of EGCG was tested in healthy fasted humans. It was administered as capsules with water or with a light breakfast, or when incorporated within a strawberry sorbet. The results for plasma EGCG clearly revealed that taking EGCG capsules without food was better; the AUC was 2.7 and 3.9 times higher than when EGCG capsules were taken with a light breakfast (p = 0.044) or with EGCG imbedded in the strawberry sorbet (p = 0.019), respectively. This pattern was also observed for C_max and C_av. Therefore, ingesting food at the same time as EGCG, whether it was imbedded or not in food, substantially inhibited the absorption of the catechin. As with some types of medications that are affected by food, it appears that EGCG should be taken without food in order to maximise its systemic absorption. Therefore, based on these findings, ingesting EGCG with water on an empty stomach is the most appropriate method for the oral delivery of EGCG in clinical trials where EGCG is to be investigated as a potential bioactive nutraceutical in humans. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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14 pages, 812 KB

Open AccessArticle

Discrimination between Leave of Apocynum venetum and Its Adulterant, A. pictum Based on Antioxidant Assay and Chemical Profiles Combined with Multivariate Statistical Analysis

by Chi-On Chan, Ching-Ching Lau, Yam-Fung Ng, Li-Jia Xu, Si-Bao Chen, Shun-Wan Chan and Daniel Kam-Wah Mok

Antioxidants 2015, 4(2), 359-372; https://doi.org/10.3390/antiox4020359 - 8 May 2015

Cited by 15 | Viewed by 6716

Abstract

An integrated approach including chemical and biological assessments was developed to investigate the differences between Apocynum venetum L. (AV) and its adulterant, Apocynum pictum Schrenk (AP). Ten flavonoids were tentatively identified by ultra-visible and mass spectra data. The chemical component, hyperoside, was [...] Read more.

An integrated approach including chemical and biological assessments was developed to investigate the differences between Apocynum venetum L. (AV) and its adulterant, Apocynum pictum Schrenk (AP). Ten flavonoids were tentatively identified by ultra-visible and mass spectra data. The chemical component, hyperoside, was identified as a critical parameter for discrimination of two species from the results of principal component analysis (PCA) and quantitative analysis. The anti-oxidative power of the herbal extracts were determined using 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) assay and H₂O₂-induced cell damage on LO2 cells. The results of the biological assays suggested that the chemical differences between AV and AP do lead to difference in activity and AV is demonstrated to have higher anti-oxidant activity. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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14 pages, 667 KB

Open AccessArticle

Systematic Study of the Content of Phytochemicals in Fresh and Fresh-Cut Vegetables

by María Isabel Alarcón-Flores, Roberto Romero-González, José Luis Martínez Vidal and Antonia Garrido Frenich

Antioxidants 2015, 4(2), 345-358; https://doi.org/10.3390/antiox4020345 - 6 May 2015

Cited by 11 | Viewed by 6902

Abstract

Vegetables and fruits have beneficial properties for human health, because of the presence of phytochemicals, but their concentration can fluctuate throughout the year. A systematic study of the phytochemical content in tomato, eggplant, carrot, broccoli and grape (fresh and fresh-cut) has been performed [...] Read more.

Vegetables and fruits have beneficial properties for human health, because of the presence of phytochemicals, but their concentration can fluctuate throughout the year. A systematic study of the phytochemical content in tomato, eggplant, carrot, broccoli and grape (fresh and fresh-cut) has been performed at different seasons, using liquid chromatography coupled to triple quadrupole mass spectrometry. It was observed that phenolic acids (the predominant group in carrot, eggplant and tomato) were found at higher concentrations in fresh carrot than in fresh-cut carrot. However, in the case of eggplant, they were detected at a higher content in fresh-cut than in fresh samples. Regarding tomato, the differences in the content of phenolic acids between fresh and fresh-cut were lower than in other matrices, except in winter sampling, where this family was detected at the highest concentration in fresh tomato. In grape, the flavonols content (predominant group) was higher in fresh grape than in fresh-cut during all samplings. The content of glucosinolates was lower in fresh-cut broccoli than in fresh samples in winter and spring sampling, although this trend changes in summer and autumn. In summary, phytochemical concentration did show significant differences during one-year monitoring, and the families of phytochemicals presented different behaviors depending on the matrix studied. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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23 pages, 795 KB

Open AccessReview

Oxidative Stress and Dietary Fat Type in Relation to Periodontal Disease

by Alfonso Varela-López, José L. Quiles, Mario Cordero, Francesca Giampieri and Pedro Bullón

Antioxidants 2015, 4(2), 322-344; https://doi.org/10.3390/antiox4020322 - 28 Apr 2015

Cited by 39 | Viewed by 8404

Abstract

Oxidative stress is one of the main factors studied to explain the pathophysiological mechanisms of inflammatory conditions, such as periodontitis. In this respect, nutrition may be of great importance. Actually, research on nutrients’ effects on periodontal diseases has expanded to include those influencing [...] Read more.

Oxidative stress is one of the main factors studied to explain the pathophysiological mechanisms of inflammatory conditions, such as periodontitis. In this respect, nutrition may be of great importance. Actually, research on nutrients’ effects on periodontal diseases has expanded to include those influencing the redox status, which correlates to the inflammatory process. Dietary fat or lipids are often blamed as the major source of excess energy. Consequently, when caloric intake exceeds energy expenditure, the resultant substrate-induced increase in citric acid cycle activity generates an excess of reactive oxygen species (ROS). In addition, dietary fatty acid intake influences in relative fatty acid composition of biological membranes determining its susceptibility to oxidative alterations. From this standpoint, here, we reviewed studies analyzing the dietary fat role in periodontal disease. Research data suggest that periodontal health could be achieved by main dietary strategies which include substitution of saturated fats with monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), particularly n-3 PUFA. Maybe in the future, we should analyze the diet and provide some advice to periodontitis patients to improve treatment outcomes. Full article

(This article belongs to the Special Issue Antioxidants and Periodontal Diseases)

18 pages, 849 KB

Open AccessArticle

Quercetin, a Flavonoid Antioxidant, Ameliorated Procarbazine-Induced Oxidative Damage to Murine Tissues

by Ebenezer Tunde Olayinka, Ayokanmi Ore, Oluwatobi Adewumi Adeyemo, Olaniyi Solomon Ola, Olaoluwa Oluwaseun Olotu and Roseline Chinonye Echebiri

Antioxidants 2015, 4(2), 304-321; https://doi.org/10.3390/antiox4020304 - 28 Apr 2015

Cited by 26 | Viewed by 9805

Abstract

Procarbazine (PCZ) (indicated in Hodgkin’s disease), is an alkylating agent known to generate free radicals in vivo, while Quercetin (QCT) is a flavonoid antioxidant with proven free radical scavenging capacity. This study investigated the protective effects of QCT on PCZ-induced oxidative damage in [...] Read more.

Procarbazine (PCZ) (indicated in Hodgkin’s disease), is an alkylating agent known to generate free radicals in vivo, while Quercetin (QCT) is a flavonoid antioxidant with proven free radical scavenging capacity. This study investigated the protective effects of QCT on PCZ-induced oxidative damage in the rat. Male Wistar rats (160–180 g) were randomized into five groups (n = 5/group): I (control), II PCZ-treated (2 mg/kg body weight (bw) for seven days); III pre-treated with QCT (20 mg/kg bw) for seven days, followed by PCZ for seven days; IV co-treated with PCZ and QCT for seven days and V administered QCT alone for seven days. PCZ caused a significant increase in plasma total bilirubin, urea, and creatinine when compared with control (P < 0.05). Similarly, plasma activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transferase (γ-GT) were significantly increased in the PCZ-treated group relative to control. Furthermore, PCZ caused a significant decrease in the activities of hepatic superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) as well as levels of ascorbic acid (AA) and glutathione (GSH). This was followed by a significant increase in hepatic malondialdehyde (MDA) content. However, QCT pre-treatment and co-treatment ameliorated the PCZ-induced changes in plasma levels of urea, creatinine, and bilirubin as well as the activities of ALP, AST, ALT, and GGT. QCT also ameliorated hepatic AA and GSH levels and the activities of SOD, CAT, and GST. This all suggests that QCT protected against PCZ-induced oxidative damage in rats. Full article

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11 pages, 369 KB

Open AccessReview

A Review of the Use of Topical Calendula in the Prevention and Treatment of Radiotherapy-Induced Skin Reactions

by Joyson Kodiyan and Kyle T. Amber

Antioxidants 2015, 4(2), 293-303; https://doi.org/10.3390/antiox4020293 - 23 Apr 2015

Cited by 43 | Viewed by 11659

Abstract

Calendula is a topical agent derived from a plant of the marigold family Calendula Officinalis. Containing numerous polyphenolic antioxidants, calendula has been studied in both the laboratory and clinical setting for the use in treating and preventing radiation induced skin toxicity. Despite [...] Read more.

Calendula is a topical agent derived from a plant of the marigold family Calendula Officinalis. Containing numerous polyphenolic antioxidants, calendula has been studied in both the laboratory and clinical setting for the use in treating and preventing radiation induced skin toxicity. Despite strong evidence in the laboratory supporting calendula’s mechanism of action in preventing radiation induced skin toxicity, clinical studies have demonstrated mixed results. In light of the controversy surrounding the efficacy of calendula in treating and preventing radiodermatitis, the topic warrants further discussion. Full article

(This article belongs to the Special Issue Innovative Strategies against Radiation-Induced Toxicity and Adverse Effects)

12 pages, 983 KB

Open AccessArticle

In Vitro Cultivars of Vaccinium corymbosum L. (Ericaceae) are a Source of Antioxidant Phenolics

by Rodrigo A. Contreras, Hans Köhler, Marisol Pizarro and Gustavo E. Zúiga

Antioxidants 2015, 4(2), 281-292; https://doi.org/10.3390/antiox4020281 - 9 Apr 2015

Cited by 16 | Viewed by 7941

Abstract

The antioxidant activity and phenolic composition of six in vitro cultured blueberry seedlings were determined. Extracts were prepared in 85% ethanol from 30 days old in vitro cultured plants and used to evaluate the antioxidant capacities that included Ferric reducing antioxidant power (FRAP) [...] Read more.

The antioxidant activity and phenolic composition of six in vitro cultured blueberry seedlings were determined. Extracts were prepared in 85% ethanol from 30 days old in vitro cultured plants and used to evaluate the antioxidant capacities that included Ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazin (DPPH•) scavenging ability, total polyphenols (TP) and the partial phenolic composition performed by high performance liquid chromatography with diode array detector (HPLC-DAD), liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS (ESI-QqQ)). All ethanolic extracts from in vitro blueberry cultivars displayed antioxidant activity, with Legacy, Elliott and Bluegold cultivars being the most active. In addition, we observed a positive correlation between phenolic content and antioxidant activity. Our results suggest that the antioxidant activity of the extracts is related to the content of chlorogenic acid myricetin, syringic acid and rutin, and tissue culture of blueberry seedlings is a good tool to obtain antioxidant extracts with reproducible profile of compounds. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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12 pages, 549 KB

Open AccessArticle

Betalains, Phenols and Antioxidant Capacity in Cactus Pear [Opuntia ficus-indica (L.) Mill.] Fruits from Apulia (South Italy) Genotypes

by Clara Albano, Carmine Negro, Noemi Tommasi, Carmela Gerardi, Giovanni Mita, Antonio Miceli, Luigi De Bellis and Federica Blando

Antioxidants 2015, 4(2), 269-280; https://doi.org/10.3390/antiox4020269 - 1 Apr 2015

Cited by 151 | Viewed by 13482

Abstract

Betacyanin (betanin), total phenolics, vitamin C and antioxidant capacity (by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays) were investigated in two differently colored cactus pear (Opuntia ficus-indica (L.) Mill.) genotypes, one with purple fruit and the other with [...] Read more.

Betacyanin (betanin), total phenolics, vitamin C and antioxidant capacity (by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays) were investigated in two differently colored cactus pear (Opuntia ficus-indica (L.) Mill.) genotypes, one with purple fruit and the other with orange fruit, from the Salento area, in Apulia (South Italy). In order to quantitate betanin in cactus pear fruit extracts (which is difficult by HPLC because of the presence of two isomers, betanin and isobetanin, and the lack of commercial standard with high purity), betanin was purified from Amaranthus retroflexus inflorescence, characterized by the presence of a single isomer. The purple cactus pear variety showed very high betanin content, with higher levels of phenolics, vitamin C, and antioxidant capacity (TEAC) than the orange variety. These findings confirm the potential for exploiting the autochthonous biodiversity of cactus pear fruits. In particular, the purple variety could be an interesting source of colored bioactive compounds which not only have coloring potential, but are also an excellent source of dietary antioxidant components which may have beneficial effects on consumers’ health. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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21 pages, 282 KB

Open AccessReview

Mechanisms of Photoaging and Cutaneous Photocarcinogenesis, and Photoprotective Strategies with Phytochemicals

by Ricardo Bosch, Neena Philips, Jorge A. Suárez-Pérez, Angeles Juarranz, Avani Devmurari, Jovinna Chalensouk-Khaosaat and Salvador González

Antioxidants 2015, 4(2), 248-268; https://doi.org/10.3390/antiox4020248 - 26 Mar 2015

Cited by 345 | Viewed by 25546

Abstract

Photoaging and photocarcinogenesis are primarily due to solar ultraviolet (UV) radiation, which alters DNA, cellular antioxidant balance, signal transduction pathways, immunology, and the extracellular matrix (ECM). The DNA alterations include UV radiation induced thymine-thymine dimers and loss of tumor suppressor gene p53. UV [...] Read more.

Photoaging and photocarcinogenesis are primarily due to solar ultraviolet (UV) radiation, which alters DNA, cellular antioxidant balance, signal transduction pathways, immunology, and the extracellular matrix (ECM). The DNA alterations include UV radiation induced thymine-thymine dimers and loss of tumor suppressor gene p53. UV radiation reduces cellular antioxidant status by generating reactive oxygen species (ROS), and the resultant oxidative stress alters signal transduction pathways such as the mitogen-activated protein kinase (MAPK), the nuclear factor-kappa beta (NF-κB)/p65, the janus kinase (JAK), signal transduction and activation of transcription (STAT) and the nuclear factor erythroid 2-related factor 2 (Nrf2). UV radiation induces pro-inflammatory genes and causes immunosuppression by depleting the number and activity of the epidermal Langerhans cells. Further, UV radiation remodels the ECM by increasing matrixmetalloproteinases (MMP) and reducing structural collagen and elastin. The photoprotective strategies to prevent/treat photoaging and photocarcinogenesis include oral or topical agents that act as sunscreens or counteract the effects of UV radiation on DNA, cellular antioxidant balance, signal transduction pathways, immunology and the ECM. Many of these agents are phytochemical derivatives and include polyphenols and non-polyphenols. The flavonoids are polyphenols and include catechins, isoflavones, proanthocyanidins, and anthocyanins, whereas the non-flavonoids comprise mono phenolic acids and stilbenes. The natural sources of polyphenols include tea, cocoa, grape/wine, soy, pomegranate, and Polypodium leucotomos. The non-phenolic phytochemicals include carotenoids, caffeine and sulphoraphance (SFN). In addition, there are other phytochemical derivatives or whole extracts such as baicalin, flavangenol, raspberry extract, and Photomorphe umbellata with photoprotective activity against UVB radiation, and thereby carcinogenesis. Full article

(This article belongs to the Special Issue Innovative Strategies against Radiation-Induced Toxicity and Adverse Effects)

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Antioxidants, Volume 4, Issue 2 (June 2015) – 12 articles , Pages 248-446

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