Search results for: radical scavenger
139 Synthesis and Characterization of PH Sensitive Hydrogel and Its Application in Controlled Drug Release of Tramadol
Authors: Naima Bouslah, Leila Bounabi, Farid Ouazib, Nabila Haddadine
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Conventional release dosage forms are known to provide an immediate release of the drug. Controlling the rate of drug release from polymeric matrices is very important for a number of applications, particularly in the pharmaceutical area. Hydrogels are polymers in three-dimensional network arrangement, which can absorb and retain large amounts of water without dissolution. They have been frequently used to develop controlled released formulations for oral administration because they can extend the duration of drug release and thus reduce dose to be administrated improving patient compliance. Tramadol is an opioid pain medication used to treat moderate to moderately severe pain. When taken as an immediate-release oral formulation, the onset of pain relief usually occurs within about an hour. In the present work, we synthesized pH-responsive hydrogels of (hydroxyl ethyl methacrylate-co-acrylic acid), (HEMA-AA) for control drug delivery of tramadol in the gastro-intestinal tractus. The hydrogels with different acrylic acid content, were synthesized by free radical polymerization and characterized by FTIR spectroscopy, X ray diffraction analysis (XRD), differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). FTIR spectroscopy has shown specific hydrogen bonding interactions between the carbonyl groups of the hydrogels and hydroxyl groups of tramadol. Both the XRD and DSC studies revealed that the introduction of tramadol in the hydrogel network induced the amorphization of the drug. The swelling behaviour, absorptive kinetics and the release kinetics of tramadol in simulated gastric fluid (pH 1.2) and in simulated intestinal fluid (pH 7.4) were also investigated. The hydrogels exhibited pH-responsive behavior in the swelling study. The (HEMA-AA) hydrogel swelling was much higher in pH =7.4 medium. The tramadol release was significantly increased when pH of the medium was changed from simulated gastric fluid (pH 1.2) to simulated intestinal fluid (pH 7.4). Using suitable mathematical models, the apparent diffusional coefficients and the corresponding kinetic parameters have been calculated.Keywords: biopolymres, drug delivery, hydrogels, tramadol
Procedia PDF Downloads 357138 Spray Drying and Physico-Chemical Microbiological Evaluation of Ethanolic Extracts of Propolis
Authors: David Guillermo Piedrahita Marquez, Hector Suarez Mahecha, Jairo Humberto Lopez
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The propolis are substances obtained from the beehive have an action against pathogens, prooxidant substances and free radicals because of its polyphenols content, this has motivated the use of these compounds in the food and pharmaceutical industries. However, due to their organoleptic properties and their ability to react with other compounds, their application has been limited; therefore, the objective of this research was to propose a mechanism to protect propolis and mitigate side effects granted by its components. To achieve the stated purpose ethanolic extracts of propolis (EEP) from three samples from Santander were obtained and their antioxidant and antimicrobial activity were evaluated in order to choose the extract with the biggest potential. Subsequently mixtures of the extract with maltodextrin were prepared by spray drying varying concentration and temperature, finally the yield, the physicochemical, and antioxidant properties of the products were measured. It was concluded that Socorro propolis was the best for the production of microencapsulated due to their activity against pathogenic strains, for its large percentage of DPPH radical inactivation and for its high phenolic content. In spray drying, the concentration of bioactive had a greater impact than temperature and the conditions set allowed a good performance and the production of particles with high antioxidant potential and little chance of proliferation of microorganisms. Also, it was concluded that the best conditions that allowed us to obtain the best particles were obtained after drying a mixture 1:2 ( EEP: Maltodextrin), besides the concentration is the most important variable in the spray drying process, at the end we obtained particles of different sizes and shape and the uniformity of the surface depend on the temperature. After watching the previously mentioned microparticles by scanning electron microscopy (SEM) it was concluded that most of the particles produced during the spray dry process had a spherical shape and presented agglomerations due to the moisture content of the ethanolic extracts of propolis (EEP), the morphology of the microparticles contributed to the stability of the final product and reduce the loss of total phenolic content.Keywords: spray drying, propolis, maltodextrin, encapsulation, scanning electron microscopy
Procedia PDF Downloads 287137 The Seeds of Limitlessness: Dambudzo Marechera's Utopian Thinking
Authors: Emily S. M. Chow
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The word ‘utopia’ was coined by Thomas More in Utopia (1516). Its Greek roots ‘ou’ means ‘not’ and ‘topos’ means ‘place.’ In other words, it literally refers to ‘no-place.’ However, the possibility of having an alternative and better future society has always been appealing. In fact, at the core of every utopianism is the search for a future alternative state with the anticipation of a better life. Nonetheless, the practicalities of such ideas have never ceased to be questioned. At times, building a utopia presents itself as a divisive act. In addition to the violence that must be employed to sweep away the old regime in order to make space for the new, all utopias carry within them the potential for bringing catastrophic consequences to human life. After all, every utopia seeks to remodel the individual in a very particular way for the benefit of the masses. In this sense, utopian thinking has the potential both to create and destroy the future. While writing during a traumatic transitional period in Zimbabwe’s history, Dambudzo Marechera witnessed an age of upheavals in which different parties battled for power over Zimbabwe. Being aware of the fact that all institutionalized narratives, be they originated from the governance of the UK, Ian Smith’s white minority regime or Zimbabwe’s revolutionary parties, revealed themselves to be nothing more than fiction, Marechera realized the impossibility of determining reality absolutely. As such, this thesis concerns the writing of the Zimbabwean maverick, Dambudzo Marechera. It argues that Marechera writes a unique vision of utopia. In short, for Marechera utopia is not a static entity but a moment of perpetual change. He rethinks utopia in the sense that he phrases it as an event that ceaselessly contests institutionalized and naturalized narratives of a post-colonial self and its relationship to society. Marechera writes towards a vision of an alternative future of the country. Yet, it is a vision that does not constitute a fully rounded sense of utopia. Being cautious about the world and the operation of power upon the people, rather than imposing his own utopian ideals, Marechera chooses to instead peeling away the narrative constitution of the self in relation to society in order to turn towards a truly radical utopian thinking that empowers the individual.Keywords: African literature, Marechera, post-colonial literature, utopian studies
Procedia PDF Downloads 412136 Alternation of Executive Power and Democratic Governance in Nigeria: The Role of Independent National Electoral Commission, 1999-2014
Authors: J. Tochukwu Omenma
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Buzzword in Nigeria is that democracy has “come to stay”. Politicians in their usual euphoria consider democracy as already consolidated in the country. Politicians linked this assumption to three fundamental indicators – (a) multiparty system; (b) regular elections and (c) absence of military coup after 15 years of democracy in Nigeria. Beyond this assumption, we intend to empirically verify these claims and assumptions, by relying on Huntington’s conceptualization of democratic consolidation. Though, Huntington asserts that multipartism, regular elections and absence of any major obstacle leading to reversal of democracy are significant indicators of democratic consolidation, but the presence of those indicators must result to alternation of executive power for democratic consolidation to occur. In other words, regular conduct of election and existence of multiple political parties are not enough for democratic consolidation, rather free and fair elections. Past elections were characterized of massive fraud and irregularities casting doubts on integrity of electoral management body (EMB) to conduct free and fair elections in Nigeria. There are three existing perspectives that have offered responses to the emasculation of independence of EMB. One is a more popular position indicating that the incumbent party, more than the opposition party, influence the EMB activities with the aim of rigging elections; the other is a more radical perspective that suggests that weakening of EMB power is more associated with the weakest party than with the incumbent; and the last, is that godfather(s) are in direct control of EMB members thereby controlling the process of electoral process to the advantage of the godfather(s). With empirical evidence sourced from the reports of independent election monitors, (European Union, Election Observation Mission in Nigeria) this paper shows at different electoral periods that, in terms of influencing election outcomes, the incumbent and godfather have been more associated with influencing election results than the opposition. The existing nature of executive power in Nigeria provides a plausible explanation for the incumbent’s overbearing influence thereby limiting opportunity for free and fair elections and by extension undermining the process of democratic consolidation in Nigeria.Keywords: political party, democracy, democratic consolidation, election, godfatherism
Procedia PDF Downloads 491135 Effects of Kolavironon Liver Oxidative Stress and Beta-Cell Damage in Streptozotocin-Induced Diabetic Rats
Authors: Omolola R. Ayepola, Nicole L. Brooks, Oluwafemi O. Oguntibeju
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The liver plays an important role in the regulation of blood glucose and is a target organ of hyperglycaemia. Hyperglycemia plays a crucial role in the onset of various liver diseases and may culminate into hepatopathy if untreated. Alteration in antioxidant defense and increase in oxidative stress that results in tissue injury is characteristic of diabetes. We evaluated the protective effects of kolaviron-a biflavonoid complex, on hepatic antioxidants, lipid peroxidation and apoptosis in the liver of diabetic rats. To induce type I diabetes, rats were injected with streptozotocin intraperitoneally at a single dose of 50 mg/kg. Oral treatment of diabetic rats with kolaviron (100 mg/kg) started on the 6th day after diabetes induction and continued for 6 weeks (5 times weekly). Diabetic rats exhibited a significant increase in the peroxidation of hepatic lipids as observed from the elevated level of malondialdehyde (MDA) estimated by High-Performance Liquid Chromatography. In addition, Oxygen Radical Absorbance Capacity (ORAC), ratio of reduced to oxidized glutathione (GSH/GSSG) and catalase (CAT) activity was decreased in the liver of diabetic rats. TUNEL assay revealed increased apoptotic cell death in the liver of diabetic rats. Examination of Pancreatic beta-cells by immunohistochemical methods revealed beta cell degeneration and reduction in beta cell/ islet area in the diabetic controls. Kolaviron-treatment increased the area of insulin immunoreactive beta-cells significantly. Kolaviron attenuated lipid peroxidation and apoptosis in the liver of diabetic rats, increased CAT activity GSH levels and the resultant GSH: GSSG. The ORAC of kolaviron-treated diabetic liver was restored to near-normal values. Kolaviron protects the liver against oxidative and apoptotic damage induced by hyperglycemia. The antidiabetic effect of kolaviron may also be related to its beneficial effects on beta-cell function.Keywords: diabetes mellitus, kolaviron, oxidative stress, liver, apoptosis
Procedia PDF Downloads 385134 Degradation Study of Food Colorants by SingletOxygen
Authors: A. T. Toci, M. V. B. Zanoni
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The advanced oxidation processes have been defined as destructive technologies treatment of wastewater. These involve the formation of powerful oxidizing agents (usually hydroxyl radical .OH) capable of reacting with organic compounds present in wastewater, transforming damaging substances in CO2 and H2O (mineralization) or other innocuous products. However, the photochemical degradation with singlet oxygen has been little explored as oxidative pathway for the treatment of effluents containing food colorants. The molecular oxygen is an effective suppressor of organic molecules in the triplet excited state. One of the possible results of the physical withdrawal is the formation of singlet oxygen. Studies with singlet oxygen (1O2) show an high reactivity of the excited state of the molecule with olefins, aromatic hydrocarbons and a number of other organic and inorganic compounds. Its reactivity is about 2500 times larger than the oxygen in the ground state. Thus, in this work, it was studied the degradation of some dyes used in food industry (tartrazine, sunset yellow, erythrosine and carmoisine) by singlet oxygen. The sensitizer used for generating the 1O2 was methylene blue, which has a quantum yield generation of 0.50. Samples were prepared in water at a concentration of 5 ppm and irradiated with a sunlight simulator (Newport brand, model no. 67005) by consecutive 8h. The absorption spectra of UV-Vis molecules were made each hour irradiation. The degradation kinetics for each dye was determined using the maximum length of each dye absorption. The analysis by UV-Vis revealed that the processes were very efficient for the colorants sunset yellow and carmoisine. Both presented degradation kinetics of order zero with degradation constants 0.416 and 0.104, respectively. In the case of sunset yellow degradation reached 53% after 7h irradiation, Demonstrating the process efficiency. The erithrosine presented during the period irradiated a oscillating degradation kinetics, which requires further study. In the other hand, tartrazine was stable in the presence of 1O2. The investigation of the dyes degradation products owned degradation by 1O2 are underway, the techniques used for this are MS and NMR. The results of this study will enable the application of the cleanest methods for the treatment of industrial effluents, as there are other non-toxic and polluting molecules to generate 1O2.Keywords: food colourants, singlet oxygen, degradation, wastewater, oxidative
Procedia PDF Downloads 397133 Cognitive Models of Health Marketing Communication in the Digital Era: Psychological Factors, Challenges, and Implications
Authors: Panas Gerasimos, Kotidou Varvara, Halkiopoulos Constantinos, Gkintoni Evgenia
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As a result of growing technology and briefing by the internet, users resort to the internet and subsequently to the opinion of an expert. In many cases, they take control of their health in their hand and make a decision without the contribution of a doctor. According to that, this essay intends to analyze the confidence of searching health issues on the internet. For the fulfillment of this study, there has been a survey among doctors in order to find out the reasons a patient uses the internet about their health problems and the consequences that health information could lead by searching on the internet, as well. Specifically, the results regarding the research of the users demonstrate: a) the majority of users make use of the internet about health issues once or twice a month, b) individuals that possess chronic disease make health search on the internet more frequently, c) the most important topics that the majority of users usually search are pathological, dietary issues and the search of issues that are associated with doctors and hospitals. However, it observed that topic search varies depending on the users’ age, d) the most common sources of information concern the direct contact with doctors, as there is a huge preference from the majority of users over the use of the electronic form for their briefing and e) it has been observed that there is large lack of knowledge about e-health services. From the doctor's point of view, the following conclusions occur: a) almost all doctors use the internet as their main source of information, b) the internet has great influence over doctors’ relationship with the patients, c) in many cases a patient first makes a visit to the internet and then to the doctor, d) the internet significantly has a psychological impact on patients in order to for them to reach a decision, e) the most important reason users choose the internet instead of the health professional is economic, f) the negative consequence that emerges is inaccurate information, g) and the positive consequences are about the possibility of online contact with the doctor and contributes to the easy comprehension of the doctor, as well. Generally, it’s observed from both sides that the use of the internet in health issues is intense, which declares that the new means the doctors have at their disposal, produce the conditions for radical changes in the way of providing services and in the doctor-patient relationship.Keywords: cognitive models, health marketing, e-health, psychological factors, digital marketing, e-health services
Procedia PDF Downloads 206132 Hepatoprotective and Immunostimulative Properties of Medicinal Plants against Tuberculosis
Authors: Anna-Mari Kok, Carel B. Oosthuizen, Namrita Lall
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Tuberculosis (TB) is a disease caused by the bacterial pathogen Mycobacterium tuberculosis. It is associated with high mortality rates in both developing and developed countries. Many higher plants are found that are medicinally associated with tuberculosis infection. Plants belonging to thirteen families were selected, based on their traditional usage for tuberculosis and its associated symptoms. Eight plants showed the best antimycobacterial activities (MIC-value ≤ 500.0 µg/ml) against M. tuberculosis H37Rv. LS was found to have a minimum inhibitory concentration (MIC) of 125 µg/ml whereas, Tulbaghia violacea, Heteromorpha arborescens, Sutherlandia frutescens, Eucalyptus deglupta, and Plectranthus neochilus were found to have a MIC value of 250 µg/ml against M. tuberculosis H37Rv. Cytotoxicity values on U937 and HepG2 cells were obtained and the IC50 values ranged between 40 ±4.30 and > 400 µg/ml for the U937 cell line and 72.4 ±1.50 and > 400 µg/ml for the HepG2 cell line. Heteromorpha arborescens had the lowest IC50 value in both cell lines and therefore showed moderate levels of toxicity. Of the 19 samples that underwent the 2, 2- diphenyl- 1- picrylhydrazyl (DPPH) antioxidant assay, Eucalyptus deglupta and Melianthus major showed significant free radical scavenging activities with concentrations of 1.33 and 1.32 µg/ml respectively for the inhibition of DPPH. Hepatotoxicity induced by acetaminophen identified Searsia lancea with hepatoprotective activity of 59.37% at a ¼ IC50 concentration. Out of the 7 samples that were investigated for their immunomodulatory capabilities, Eucalyptus deglupta produced the most IL-12 with Sutherlandia frutescens also showing positive results for IL-12 production. In the present study, Eucalyptus deglupta showed the most promising results with good activity against M. tuberculosis with an MIC-value of 250 µg/ml. It also has potent antioxidant activity with an IC50 value of 1.33 µg/ml. This sample also stimulated high production of the cytokine, IL-12. Searsia lancea showed moderate antimycobacterial acticvity with an MIC-value of 500 µg/ml. The antioxidant potential also showed promising results with an IC50 value of 4.50 µg/ml. The hepatoprotective capability of Searsia lancea was 59.34% at a ¼ IC50 concentration. Another sample Sutherlandia frutescens showed effective antimycobacterial activity with an MIC-value of 250 µg/ml. It also stimulated production of IL-12 with 13.43 pg/ml produced. These three samples can be considered for further studies for the consideration as adjuvants for current tuberculosis treatment.Keywords: adjuvant, hepatoprotection, immunomodulation, tuberculosis
Procedia PDF Downloads 305131 Literature Review of Rare Synchronous Tumours
Authors: Diwei Lin, Amanda Tan, Rajinder Singh-Rai
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We present the first reported case of a concomitant Leydig cell tumor (LCT) and paratesticular leiomyoma in an adult male with a known history of bilateral cryptorchidism. An 80-year-old male presented with a 2-month history of a left testicular lump associated with mild discomfort and a gradual increase in size on a background of bilateral cryptorchidism requiring multiple orchidopexy procedures as a child. Ultrasound confirmed a lesion suspicious for malignancy and he proceeded to a left radical orchidectomy. Histopathological assessment of the left testis revealed a concomitant testicular LCT with malignant features and paratesticular leiomyoma. Leydig cell tumors (LCTs) are the most common pure testicular sex cord-stromal tumors, accounting for up to 3% of all testicular tumors. They can occur at almost any age, but are noted to have a bi-modal distribution, with a peak incidence at 6 to 10 and at 20 to 50 years of age. LCT’s are often hormonally active and can lead to feminizing or virilizing syndromes. LCT’s are usually regarded as benign but can rarely exhibit malignant traits. Paratesticular tumours are uncommon and their reported prevalence varies between 3% and 16%. They occur in a complex anatomical area which includes the contents of the spermatic cord, testicular tunics, epididymis and vestigial remnants. Up to 90% of paratesticular tumours are believed to originate from the spermatic cord, though it is often difficult to definitively ascertain the exact site of origin. Although any type of soft-tissue neoplasm can be found in the paratesticular region, the most common benign tumors reported are lipomas of the spermatic cord, adenomatoid tumours of the epididymis and leiomyomas of the testis. Genetic studies have identified potential mutations that could potentially cause LCTs, but there are no known associations between concomitant LCTs and paratesticular tumors. The presence of cryptorchidism in adults with both LCTs and paratesticular neoplasms individually has been previously reported and it appears intuitive that cryptorchidism is likely to be associated with the concomitant presentation in this case report. This report represents the first documented case in the literature of a unilateral concomitant LCT and paratesticular leiomyoma on a background of bilateral cryptorchidism.Keywords: testicular cancer, leydig cell tumour, leiomyoma, paratesticular neoplasms
Procedia PDF Downloads 361130 Techno-Functional Characteristics, Mineral Composition and Antioxidant Potential of Dietary Fiber Extracted by Sonication from Different Oat Cultivars (Avena sativa)
Authors: Muhammad Suhail Ibrahim, Muhammad Nadeem, Muhammad Sultan, Uzair Sajjad, Khalid Hamid, Tahir Mahmood Qureshi, Sadaf Javaria
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Metabolic disorders, including hypertension, diabetes, cardiovascular disease etc., are major threats to public health and economy. Management and prevention of alarmingly increasing disorders have attracted researchers to explore natural barriers against these disorders. The objective of this study was to explore oats as a potential source of dietary fiber. Extraction of dietary was optimized by response surface methodology, and five indigenous oat cultivars, including SGD2011, Avon, SGD81, PD2LV65, and S2000, were also characterized for techno-functional characteristics, mineral composition and phytochemical quantification. These cultivars varied significantly (p < 0.05) for oil holding capacity, water saturation, and water holding capacity, respectively. SGD81 showed the highest oil-holding capacity, water-holding capacity, and water saturation due to the highest fraction of dietary fiber. The highest values of total phenolic contents, total flavonoid contents, total flavonol contents, 2, 2-Diphenyl-1-picrylhydrazyl radical scavenging activity, and anthocyanin were shown by SGD81, and SGD2011, respectively. All cultivars varied significantly (P<0.05) with respect to phytochemical quantification. Oat cultivars SGD81 and SGD2011 showed the best phenolic acid profile and can be effectively used as a source of nutraceuticals. Beyond the nutritional properties of oats, these also contribute and emerged as potential sources of dietary fiber and have gained attention as nutraceutical cereal crops. This approach offers oats as a natural means of dietary fiber to protect humans from alarmingly increasing metabolic disorders, and its extraction by sonication has made it a sustainable and eco-friendly strategy.Keywords: oat cultivars, dietary fibers, mineral profile, antioxidant activity, color properties
Procedia PDF Downloads 42129 Hypolipidemic and Antioxidant Effects of Mycelial Polysaccharides from Calocybe indica in Hyperlipidemic Rats Induced by High-Fat Diet
Authors: Govindan Sudha, Mathumitha Subramaniam, Alamelu Govindasamy, Sasikala Gunasekaran
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The aim of this study was to investigate the protective effect of Hypsizygus ulmarius polysaccharides (HUP) on reducing oxidative stress, cognitive impairment and neurotoxicity in D-galactose induced aging mice. Mice were subcutaneously injected with D-galactose (150 mg/kg per day) for 6 weeks and were administered HUP simultaneously. Aged mice receiving vitamin E (100 mg/kg) served as positive control. Chronic administration of D-galactose significantly impaired cognitive performance oxidative defence and mitochondrial enzymes activities as compared to control group. The results showed that HUP (200 and 400 mg/kg) treatment significantly improved the learning and memory ability in Morris water maze test. Biochemical examination revealed that HUP significantly increased the decreased activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), mitochondrial enzymes-NADH dehydrogenase, malate dehydrogenase (MDH), isocitrate dehydrogenase (ICDH), Na+K+, Ca2+, Mg2+ATPase activities, elevated the lowered total anti-oxidation capability (TAOC), glutathione (GSH), vitamin C and decreased the raised acetylcholinesterase (AChE) activities, malondialdehyde (MDA), hydroperoxide (HPO), protein carbonyls (PCO), advanced oxidation protein products (AOPP) levels in brain of aging mice induced by D-gal in a dose-dependent manner. In conclusion, present study highlights the potential role of HUP against D-galactose induced cognitive impairment, biochemical and mitochondrial dysfunction in mice. In vitro studies on the effect of HUP on scavenging DPPH, ABTS, DMPD, OH radicals, reducing power, B-carotene bleaching and lipid peroxidation inhibition confirmed the free radical scavenging and antioxidant activity of HUP. The results suggest that HUP possesses anti-aging efficacy and may have potential in treatment of neurodegenerative diseases.Keywords: aging, antioxidants, mushroom, neurotoxicity
Procedia PDF Downloads 529128 Isolation, Identification and Screening of Marine Fungi for Potential Tyrosinase Inhibitor, Antibacterial and Antioxidant for Future Cosmeceuticals
Authors: Shivankar Agrawal, Sunil Kumar Deshmukh, Colin Barrow, Alok Adholeya
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A variety of genetic and environmental factors cause various cosmetics and dermatological problems. There are already claimed drugs available in market for treating these problems. However, the challenge remains in finding more potent, environmental friendly, causing minimal side effects and economical cosmeceuticals. This leads to an increased demand for natural cosmeceutical products in the last few decades. Plant derived ingredients are limited because plants either contain toxic metabolites, grow too slow or seasonal harvesting is a problem. To identify new bioactive cosmetics ingredients of marine microbial bioresource, we screened 35 marine fungi isolated from marine samples collected from Andaman Island and west coast of India. Fungal crude extracts were investigated for their antityrosinase, antioxidant and antibacterial activities for the purpose of identifying anti-aging, skin-whitening and anti-acne biomolecule with the potential in cosmetics. In the tyrosinase inhibition and 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays, two fungal extracts, including “P2”, Talaromyces stipitatus and “D4”, Aspergillus terreus showed high inhibitory activity at 1mg/mL for tyrosinase inhibition and 0.5mg/mL for DPPH scavenging. The in vitro antimicrobial activity was investigated by the agar well diffusion method. In the tyrosinase inhibition assay, 8 extracts showed significant antibacterial activity against bacteria causing skin and wound infection in humans. In the course of systematic screening program for bioactive marine fungi, strain “D5” was found to be most potent strain with MIC value of 1mg/mL, which was morphologically identified as Simplicillium lamellicola. The effects of the most active crude extracts against their susceptible test microorganisms were also investigated by SEM analysis. Further investigations will focus on purification and characterization major active components responsible for these activities.Keywords: antioxidant, antimicrobial activity, tyrosinase, cosmeceuticals, marine fungi
Procedia PDF Downloads 281127 Sustainable Hydrogel Nanocomposites Based on Grafted Chitosan and Clay for Effective Adsorption of Cationic Dye
Authors: H. Ferfera-Harrar, T. Benhalima, D. Lerari
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Contamination of water, due to the discharge of untreated industrial wastewaters into the ecosystem, has become a serious problem for many countries. In this study, bioadsorbents based on chitosan-g-poly(acrylamide) and montmorillonite (MMt) clay (CTS-g-PAAm/MMt) hydrogel nanocomposites were prepared via free‐radical grafting copolymerization and crosslinking of acrylamide monomer (AAm) onto natural polysaccharide chitosan (CTS) as backbone, in presence of various contents of MMt clay as nanofiller. Then, they were hydrolyzed to obtain highly functionalized pH‐sensitive nanomaterials with uppermost swelling properties. Their structure characterization was conducted by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. The adsorption performances of the developed nanohybrids were examined for removal of methylene blue (MB) cationic dye from aqueous solutions. The factors affecting the removal of MB, such as clay content, pH medium, adsorbent dose, initial dye concentration and temperature were explored. The adsorption process was found to be highly pH dependent. From adsorption kinetic results, the prepared adsorbents showed remarkable adsorption capacity and fast adsorption rate, mainly more than 88% of MB removal efficiency was reached after 50 min in 200 mg L-1 of dye solution. In addition, the incorporating of various content of clay has enhanced adsorption capacity of CTS-g-PAAm matrix from 1685 to a highest value of 1749 mg g-1 for the optimized nanocomposite containing 2 wt.% of MMt. The experimental kinetic data were well described by the pseudo-second-order model, while the equilibrium data were represented perfectly by Langmuir isotherm model. The maximum Langmuir equilibrium adsorption capacity (qm) was found to increase from 2173 mg g−1 until 2221 mg g−1 by adding 2 wt.% of clay nanofiller. Thermodynamic parameters revealed the spontaneous and endothermic nature of the process. In addition, the reusability study revealed that these bioadsorbents could be well regenerated with desorption efficiency overhead 87% and without any obvious decrease of removal efficiency as compared to starting ones even after four consecutive adsorption/desorption cycles, which exceeded 64%. These results suggest that the optimized nanocomposites are promising as low cost bioadsorbents.Keywords: chitosan, clay, dye adsorption, hydrogels nanocomposites
Procedia PDF Downloads 122126 Unveiling the Reaction Mechanism of N-Nitroso Dimethyl Amine Formation from Substituted Hydrazine Derivatives During Ozonation: A Computational Study
Authors: Rehin Sulay, Anandhu Krishna, Jintumol Mathew, Vibin Ipe Thomas
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N-Nitrosodimethyl amine, the simplest member of the N-Nitrosoamine family, is a carcinogenic and mutagenic agent that has gained considerable research interest owing to its toxic nature. Ozonation of industrially important hydrazines such as unsymmetrical dimethylhydrazine (UDMH) or monomethylhydrazine (MMH) has been associated with NDMA formation and accumulation in the environment. UDMH/MMH - ozonation also leads to several other transformation products such as acetaldehyde dimethyl hydrazone (ADMH), tetramethyl tetra azene (TMT), diazomethane, methyl diazene, etc, which can be either precursors or competitors for NDMA formation.In this work, we explored the formation mechanism of ADMH and TMT from UDMH-ozonation and their further oxidation to NDMA using the second-order Moller Plesset perturbation theory employing the 6-311G(d) basis set. We have also investigated how MMH selectively forms methyl diazene and diazomethane under normal conditions and NDMA in the presence of excess ozone. Our calculations indicate that the reactions proceed via an initial H abstraction from the hydrazine –NH2 group followed by the oxidation of the generated N-radical species. The formation of ADMH from the UDMH-ozone reaction involves an acetaldehyde intermediate, which then reacts with a second UDMH molecule to generate ADMH. The preferable attack of ozone molecule on N=C bond of ADMH generates DMAN intermediate, which subsequently undergoes oxidation to form NDMA. Unlike other transformation products, TMT formation occurs via the dimerization of DMAN. Though there exist a N=N bonds in the TMT, which are preferable attacking sites for ozone, experimental studies show the lower yields of NDMA formation, which corroborates with the high activation barrier required for the process(42kcal/mol).Overall, our calculated results agree well with the experimental observations and rate constants. Computational calculations bring insights into the electronic nature and kinetics of the elementary reactions of this pathway, enabled by computed energies of structures that are not possible to access experimentally.Keywords: reaction mechanism, ozonation, substituted hydrazine, transition state
Procedia PDF Downloads 81125 A Traditional Settlement in a Modernized City: Yanbu, Saudi Arabia
Authors: Hisham Mortada
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Transition in the urban configuration of Arab cities has never been as radical and visible as it has been since the turn of the last century. The emergence of new cities near historical settlements of Arabia has spawned a series of developments in and around the old city precincts. New developments are based on advanced technology and conform to globally prevalent standards of city planning, superseding the vernacular arrangements based on traditional norms that guided so-called ‘city planning’. Evidence to this fact are the extant Arab buildings present at the urban core of modern cities, which inform us about intricate spatial organization. Organization that subscribed to multiple norms such as, satisfying gender segregation and socialization, economic sustainability, and ensuring security and environmental coherence etc., within settlement compounds. Several participating factors achieved harmony in such an inclusive city—an organization that was challenged and apparently replaced by the new planning order in the face of growing needs of globalized, economy-centric and high-tech models of development. Communities found it difficult to acclimatize with the new western planning models that were implemented at a very large scale throughout the Kingdom, which later experienced spatial re-structuring to suit users’ needs. A closer look the ancient city of Yanbu, now flanked with such new developments, allows us to differentiate and track the beginnings of this unprecedented transition in settlement formations. This paper aims to elaborate the Arabian context offered to both the ‘traditional’ and ‘modern’ planning approaches, in order to understand challenges and solutions offered by both at different times. In the process it will also establish the inconsistencies and conflicts that arose with the shift in planning paradigm, from traditional-'cultural norms’, to modern-'physical planning', in the Arabian context. Thus, by distinguishing the two divergent planning philosophies, their impact of the Arabian morphology, relevance to lifestyle and suitability to the biophysical environment, it concludes with a perspective on sustainability particularly for in case of Yanbu.Keywords: Yanbu, traditional architecture, Hijaz, coral building, Saudi Arabia
Procedia PDF Downloads 321124 Exploring Polypnenolics Content and Antioxidant Activity of R. damascena Dry Extract by Spectroscopic and Chromatographic Techniques
Authors: Daniela Nedeltcheva-Antonova, Kamelia Getchovska, Vera Deneva, Stanislav Bozhanov, Liudmil Antonov
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Rosa damascena Mill. (Damask rose) is one of the most important plants belonging to the Rosaceae family, with a long historical use in traditional medicine and as a valuable oil-bearing plant. Many pharmacological effects have been reported from this plant, including anti-inflammatory, hypnotic, analgesic, anticonvulsant, anti-depressant, antianxiety, antitussive, antidiabetic, relaxant effects on tracheal chains, laxative, prokinetic and hepatoprotective activities. Pharmacological studies have shown that the various health effects of R. damascena flowers can mainly be attributed to its large amount of polyphenolic components. Phenolics possess a wide range of pharmacological activities, such as antioxidants, free-radical scavengers, anticancer, anti-inflammatory, antimutagenic, and antidepressant, with flavonoids being the most numerous group of natural polyphenolic compounds. According to the technological process in the production of rose concrete (solvent extraction with non-polar solvents of fresh rose flowers), it can be assumed that the resulting plant residue would be as rich of polyphenolics, as the plant itself, and could be used for the development of novel products with promising health-promoting effect. Therefore, an optimisation of the extraction procedure of the by-product from the rose concrete production was carried out. An assay of the extracts in respect of their total polyphenols and total flavonoids content was performed. HPLC analysis of quercetin and kaempferol, the two main flavonoids found in R. damascena, was also carried out. The preliminary results have shown that the flavonoid content in the rose extracts is comparable to that of the green tea or Gingko biloba, and they could be used for the development of various products (food supplements, natural cosmetics and phyto-pharmaceutical formulation, etc.). The fact that they are derived from the by-product of industrial plant processing could add the marketing value of the final products in addition to the well-known reputation of the products obtained from Bulgarian roses (R. damascena Mill.).Keywords: gas chromatography-mass-spectromrtry, dry extract, flavonoids, Rosa damascena Mill
Procedia PDF Downloads 152123 Effect of Wolffia globosa Incorporation on the Physical, Phytochemical and Antioxidant Properties of Breadsticks
Authors: May Phyo Wai, Tanyawan Suantawee
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The positive correlation between unhealthy diets (high in fats, sugars, carbohydrates, and low fibers) and the risk of non-communicable diseases (NCDs) like obesity, hypertension, diabetes, and heart diseases has led to a growing interest in healthier lifestyles and diets. Consequently, people are opting for foods rich in fiber and phytochemicals. Wolffia globosa, also known as duckweed or watermeal, is the smallest plant with high nutritional value, including protein, fiber, phytochemicals, and antioxidant properties. It offers numerous health benefits, such as improving gut health and lowering blood glucose levels, and it is widely available in Thailand. The purpose of this study was to develop nutritionally enhanced breadsticks utilizing vacuum heat-dried Wolffia globosa power (WP). Various concentrations of WP (0% as control, 5%, 10%, and 15 % w/w/) were added, and then the breadsticks’ physical properties (hardness, fracturability, and color), phytochemicals (total phenolic compounds: TPC and total flavonoid contents: TFC), and antioxidant properties (DPPH radical scavenging activity (DPPH) and ferric reducing antioxidant power (FRAP) assay) were investigated. Experiments were done by triplicates and data was analyzed by one-way ANOVA. The results showed that the hardness, measured by a texture analyzer, increased significantly (p<0.05) with higher WP concentrations, reaching 2,897.01 ± 77.31 g at 15% WP from 1,314.41 ± 32.52 g of the control. In contrast, the lightness (L*), redness (a*), and yellowness (b*) of the breadsticks significantly decreased (p < 0.05) in a dose-dependent manner with added WP. Incorporating WP, rich in phytochemicals and antioxidants, into the flour significantly enhanced the TPC and TFC of the breadsticks (p<0.05), with TPC and TFC increasing dose-dependently rising to 1.8-fold and 3.5-fold at 15% WP, respectively. The antioxidant power, assessed by DPPH and FRAP assays, also showed a similar trend, with significantly higher values at 10% and 15% WP (p<0.05). These results indicate that adding WP significantly boosted the TPC, TFC, DPPH, and FRAP values of the developed breadsticks. Therefore, incorporating WP into breadsticks might be a promising strategy for creating food products enriched with phytochemicals and antioxidants, offering consumers healthier options in the market.Keywords: antioxidant properties, breadsticks, phytochemicals, Wolffia globosa
Procedia PDF Downloads 36122 Effect of Phytohormones on the Development and Nutraceutical Characteristics of the Fruit Capsicum annuum
Authors: Rossy G. Olan Villegas, Gerardo Acosta Garcia, Aurea Bernardino Nicanor, Leopoldo Gonzalez Cruz, Humberto Ramirez Medina
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Capsicum annuum is a crop of agricultural and economic importance in Mexico and other countries. The fruit (pepper) contains bioactive components such as carotenoids, phenolic compounds and capsaicinoids that improve health. However, pepper cultivation is affected by biotic and abiotic factors that decrease yield. Some phytohormones like gibberellins and auxins induce the formation and development of fruit in several plants. In this study, we evaluated the effect of the exogenous application of phytohormones like gibberellic acid and indolbutyric acid on fruit development of jalapeno pepper plants, the protein profile of plant tissues, the accumulation of bioactive compounds and antioxidant activity in the pericarp and seeds. For that, plants were sprinkled with these phytohormones. The fruit collection for the control, indolbutyric acid and gibberellic acid treatments was 7 peppers per plant; however, for the treatment that combines indolbutyric acid and gibberellic acid, a fruit with the shortest length (1.52 ± 1.00 cm) and weight (0.41 ± 1.0 g) was collected compared to fruits of plants grown under other treatments. The length (4,179 ± 0,130 cm) and weight of the fruit (8,949 ± 0.583 g) increased in plants treated with indolbutyric acid, but these characteristics decreased with the application of GA3 (length of 3,349 ± 0.127 cm and a weight 4,429 ± 0.144 g). The content of carotenes and phenolic compounds increased in plants treated with GA3 (1,733 ± 0.092 and 1,449 ± 0.009 mg / g, respectively) or indolbutyric acid (1,164 ± 0.042 and 0.970 ± 0.003 mg / g). However, this effect was not observed in plants treated with both phytohormones (0.238 ± 0.021 and 0.218 ± 0.004 mg / g). Capsaicin content was higher in all treatments; but it was more noticeable in plants treated with both phytohormones, the value being 0.913 ± 0.001 mg / g (three times greater in amount). The antioxidant activity was measured by 3 different assays, 2,2-diphenyl-1-picrylhydrazyl (DPPH), antioxidant power of ferric reduction (FRAP) and 2,2'-Azinobis-3-ethyl-benzothiazoline-6-sulfonic acid ( ABTS) to find the minimum inhibitory concentration of the reducing radical (IC50 and EC50). Significant differences were observed from the application of the phytohormone, being the fruits treated with gibberellins, which had a greater accumulation of bioactive compounds. Our results suggest that the application of phytohormones modifies the development of fruit and its content of bioactive compounds.Keywords: auxins, capsaicinoids, carotenoids, gibberellins
Procedia PDF Downloads 113121 Overcoming Challenges of Teaching English as a Foreign Language in Technical Classrooms: A Case Study at TVTC College of Technology
Authors: Sreekanth Reddy Ballarapu
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The perception of the whole process of teaching and learning is undergoing a drastic and radical change. More and more student-centered, pragmatic, and flexible approaches are gradually replacing teacher-centered lecturing and structural-syllabus instruction. The issue of teaching English as a Foreign language is no exception in this regard. The traditional Present-Practice-Produce (P-P-P) method of teaching English is overtaken by Task-Based Teaching which is a subsidiary branch of Communicative Language Teaching. At this juncture this article strongly tries to convey that - Task-based learning, has an advantage over other traditional methods of teaching. All teachers of English must try to customize their texts into productive tasks, apply them, and evaluate the students as well as themselves. Task Based Learning is a double edged tool which can enhance the performance of both the teacher and the taught. The sample for this case study is a class of 35 students from Semester III - Network branch at TVTC College of Technology, Adhum - Kingdom of Saudi Arabia. The students are high school passed out and aged between 19-21years.For the present study the prescribed textbook Technical English 1 by David Bonamy was used and a number of language tasks were chalked out during the pre- task stage and the learners were made to participate voluntarily and actively. The Action Research methodology was adopted within the dual framework of Communicative Language Teaching and Task-Based Learning. The different tools such as questionnaires, feedback and interviews were used to collect data. This study provides information about various techniques of Communicative Language Teaching and Task Based Learning and focuses primarily on the advantages of using a Task Based Learning approach. This article presents in detail the objectives of the study, the planning and implementation of the action research, the challenges encountered during the execution of the plan, and the pedagogical outcome of this project. These research findings serve two purposes: first, it evaluates the effectiveness of Task Based Learning and, second, it empowers the teacher's professionalism in designing and implementing the tasks. In the end, the possibility of scope for further research is presented in brief.Keywords: action research, communicative language teaching, task based learning, perception
Procedia PDF Downloads 238120 Optimisation of Stored Alcoholic Beverage Joufinai with Reverse Phase HPLC Method and Its Antioxidant Activities: North- East India
Authors: Dibakar Chandra Deka, Anamika Kalita Deka
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Fermented alcoholic beverage production has its own stand among the tribal communities of North-East India. This biological oxidation method is followed by Ahom, Dimasa, Nishi, Miri, Bodo, Rabha tribes of this region. Bodo tribes among them not only prepare fermented alcoholic beverage but also store it for various time periods like 3 months, 6 months, 9 months, 12 months and 15 months etc. They prepare alcoholic beverage Jou (rice beer) following the fermentation of Oryza sativa with traditional yeast culture Amao. Saccharomyces cerevisiae is the main domain strain present in Amao. Dongphangrakep (Scoparia dulcis), Mwkhna (Clerodendrum viscosum), Thalir (Musa balbisina) and Khantal Bilai (Ananas cosmos) are the main plants used for Amao preparation. The stored Jou is known as Joufinai. They store the fermented mixture (rice and Amao) in anaerobic conditions for the preparation of Joufinai. We observed a successive increase in alcohol content from 3 months of storage period with 11.79 ± 0.010 (%, v/v) to 15.48 ± 0.070 (%, v/v) at 15 months of storage by a simple, reproducible and solution based colorimetric method. A positive linear correlation was also observed between pH and ethanol content with storage having correlation coefficient 0.981. Here, we optimised the detection of change in constituents of Joufinai during storage using reverse phase HPLC method. We found acetone, ethanol, acetic acid, glycerol as main constituents present in Joufinai. A very good correlation was observed from 3 months to 15 months of storage periods with its constituents. Increase in glycerol content was also detected with storage periods and hence Joufinai can be use as a precursor of above stated compounds. We also observed antioxidant activities increase from 0.056 ±2.80 mg/mL for 3 months old to 0.078± 5.33 mg/mL (in ascorbic acid equivalents) for 15 month old beverage by DPPH radical scavenging method. Therefore, we aimed for scientific validation of storage procedure used by Bodos in Joufinai production and to convert the Bodos’ traditional alcoholic beverage to a commercial commodity through our study.Keywords: Amao, correlation, beverage, joufinai
Procedia PDF Downloads 319119 Bridging Binaries: Exploring Students' Conceptions of Good Teaching within Teacher-Centered and Learner-Centered Pedagogies of Their Teachers in Disadvantaged Public Schools in the Philippines
Authors: Julie Lucille H. Del Valle
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To improve its public school education, the Philippines took a radical curriculum reform in 2012, by launching the K-to-12 program which not only added two years to its basic education but also mandated for a replacement of traditional teaching with learner-centered pedagogy, an instruction whose western underpinnings suggest improving student achievement, thus, making pedagogies in the country more or less similar with those in Europe and USA. This policy, however, placed learner-centered pedagogy in a binary opposition against teacher-centered instruction, creating a simplistic dichotomy between good and bad teaching. It is in this dichotomy that this study seeks to explore, using Critical Pedagogy of the Place as the lens, in understanding what constitutes good teaching across a range of learner-centered and teacher-centered pedagogies in the context of public schools in disadvantaged communities. Furthermore, this paper examines how pedagogical homogeneity, arguably influenced by dominant global imperatives with economic agenda – often referred as economisation of education – not only thins out local identities as structures of global schooling become increasingly similar but also limits the concept of good teaching to student outcomes and corporate employability. This paper draws from qualitative research on students, thus addressing the gap created by studies on good teaching which looked mainly into the perceptions of teachers and administrators, while overlooking those of students whose voices must be considered in the formulation of inclusive policies that advocate for true education reform. Using ethnographic methods including student focus groups, classroom observations, and teacher interviews, responses from students of disadvantaged schools reveal that good teaching includes both learner-centered and teacher-centered practices that incorporate ‘academic caring’ which sustains their motivation to achieve in school despite the challenging learning environments. The combination of these two pedagogies equips students with life-long skills necessary to gain equal access to sustainable economic opportunities in their local communities.Keywords: critical pedagogy of the place, good teaching, learner-centered pedagogy, placed-based instruction
Procedia PDF Downloads 261118 Music, Politics and Modernisation in China: An Analysis of 'Red Detachment of Women'
Authors: Lei Ping
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The Western discourse of ‘modernity’ along with its objects, ideologies, and culture are brought to Imperial China by force of arms which confronted Chinese traditions. The struggle and conflicts between ‘Zhong’ (Chinese) and ‘Wai' (foreign), ‘Jiu’(Old) and ‘Xin’(New) are continuous during the turbulent times of 19th Century China. Since the foundation of the People’s Republic in 1949, China has gone through radical social, economic and cultural reform under the Communist Party’s highly centralised and autocratic political regime. The regime and Chairman Mao’s eagerness to identify the new China and establish a revolutionary mono-culture have increased political influence on the modernisation process. The ten years of Cultural Revolution (1966-76) have commonly been neglected and separated from China’s modern history due to its political, emotional and various other associations. Its cultural productions which dictated the Chinese stages during this period, namely the yangbanxi (Model Works), are largely viewed as political propaganda material with little or no artistic value in the nation’s cultural development. This paper argues that far from being anti modernisation of culture, the yangbanxi carry continuities that originate from before the cultural revolution and influence later cultural productions up till today. The focus of the paper is on Hongse Niangzijun (The Red Detachment of Women), a ballet yangbanxi (Model Works) which was performed to President Nixon during his visit to China in 1972. It depicts the female soldier Wu Qionghua’s life story: a transformation from a peasant girl to a mature communist soldier. The first part of the paper begins with an introduction to the cultural, social and political contexts under which the ballet was created and made a yangbanxi (Model work). The second part examines the application of musical devices (e.g. instrumentation, leitmotif), ranging from typical Western techniques to Chinese musical and theatrical traditions. By analysing, connecting and comparing these musical devices of various origins, the paper illustrates that the yangbanxi (Model Works) largely contributes to the ever-present, continuing and evolving modernisation of contemporary Chinese culture.Keywords: cultural revolution, Hongse Niangzijun (Red Detachment of Women), modern China, music, Yangbanxi (model works)
Procedia PDF Downloads 244117 poly(N-Isopropylacrylamide)-Polyvinyl Alcohol Semi-Interpenetrating Network Hydrogel for Wound Dressing
Authors: Zi-Yan Liao, Shan-Yu Zhang, Ya-Xian Lin, Ya-Lun Lee, Shih-Chuan Huang, Hong-Ru Lin
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Traditional wound dressings, such as gauze, bandages, etc., are easy to adhere to the tissue fluid exuded from the wound, causing secondary damage to the wound during removal. This study takes this as the idea to develop a hydrogel dressing, to explore that the dressing will not cause secondary damage to the wound when it is torn off, and at the same time, create an environment conducive to wound healing. First, the temperature-sensitive material N-isopropylacrylamide (NIPAAm) was used as the substrate. Due to its low mechanical properties, the hydrogel would break due to pulling during human activities. Polyvinyl alcohol (PVA) interpenetrates into it to enhance the mechanical properties, and a semi-interpenetration (semi-IPN) composed of poly(N-isopropylacrylamide) (PNIPAAm) and polyvinyl alcohol (PVA) was prepared by free radical polymerization. PNIPAAm was cross-linked with N,N'-methylenebisacrylamide (NMBA) in an ice bath in the presence of linear PVA, and tetramethylhexamethylenediamine (TEMED) was added as a promoter to speed up the gel formation. The polymerization stage was carried out at 16°C for 17 hours and washed with distilled water for three days after gel formation, and the water was changed several times in the middle to complete the preparation of semi-IPN hydrogel. Finally, various tests were used to analyze the effects of different ratios of PNIPAAm and PVA on semi-IPN hydrogels. In the swelling test, it was found that the maximum swelling ratio can reach about 50% under the environment of 21°C, and the higher the ratio of PVA, the more water can be absorbed. The saturated moisture content test results show that when more PVA is added, the higher saturated water content. The water vapor transmission rate test results show that the value of the semi-IPN hydrogel is about 57 g/m²/24hr, which is not much related to the proportion of PVA. It is found in the LCST test compared with the PNIPAAm hydrogel; the semi-IPN hydrogel possesses the same critical solution temperature (30-35°C). The semi-IPN hydrogel prepared in this study has a good effect on temperature response and has the characteristics of thermal sensitivity. It is expected that after improvement, it can be used in the treatment of surface wounds, replacing the traditional dressing shortcoming.Keywords: hydrogel, N-isopropylacrylamide, polyvinyl alcohol, hydrogel wound dressing, semi-interpenetrating polymer network
Procedia PDF Downloads 80116 Pose-Dependency of Machine Tool Structures: Appearance, Consequences, and Challenges for Lightweight Large-Scale Machines
Authors: S. Apprich, F. Wulle, A. Lechler, A. Pott, A. Verl
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Large-scale machine tools for the manufacturing of large work pieces, e.g. blades, casings or gears for wind turbines, feature pose-dependent dynamic behavior. Small structural damping coefficients lead to long decay times for structural vibrations that have negative impacts on the production process. Typically, these vibrations are handled by increasing the stiffness of the structure by adding mass. That is counterproductive to the needs of sustainable manufacturing as it leads to higher resource consumption both in material and in energy. Recent research activities have led to higher resource efficiency by radical mass reduction that rely on control-integrated active vibration avoidance and damping methods. These control methods depend on information describing the dynamic behavior of the controlled machine tools in order to tune the avoidance or reduction method parameters according to the current state of the machine. The paper presents the appearance, consequences and challenges of the pose-dependent dynamic behavior of lightweight large-scale machine tool structures in production. The paper starts with the theoretical introduction of the challenges of lightweight machine tool structures resulting from reduced stiffness. The statement of the pose-dependent dynamic behavior is corroborated by the results of the experimental modal analysis of a lightweight test structure. Afterwards, the consequences of the pose-dependent dynamic behavior of lightweight machine tool structures for the use of active control and vibration reduction methods are explained. Based on the state of the art on pose-dependent dynamic machine tool models and the modal investigation of an FE-model of the lightweight test structure, the criteria for a pose-dependent model for use in vibration reduction are derived. The description of the approach for a general pose-dependent model of the dynamic behavior of large lightweight machine tools that provides the necessary input to the aforementioned vibration avoidance and reduction methods to properly tackle machine vibrations is the outlook of the paper.Keywords: dynamic behavior, lightweight, machine tool, pose-dependency
Procedia PDF Downloads 459115 A Protocol for Usability of Teaching to Students with Learning Difficulties at University: An Italian Research
Authors: Tamara Zappaterra
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The Learning Difficulties have an evolutionary nature. The international research has focused its analysis on the characteristics of Learning Difficulties in childhood, but we are still far from a thorough understanding of the nature of such disorders in adolescence and adulthood. Such issues become even more urgent in the university context. Spelling, meaning, and appropriate use of the specific vocabulary of the various disciplines represent an additional challenge for the dyslexic student. This paper explores the characteristics of Learning Difficulties in adulthood and the impact with the university teaching. It presents the results of an interdisciplinary project (educational, medical and engineering area) at University of Florence. The purpose of project is to design of a protocol for usability of teaching and individual study at university level. The project, after a first reconnaissance of user needs that have been reached with the participation of the very same protagonists, is at the stage of guidelines drafting for inclusion and education, to be used by teachers, students and administrative staff. The methodologies used are a questionnaire built on purpose and a series of focus groups with users. For collecting data during the focus groups it was decided to use a method typical of the Quality Function Deployment, a tool originally used for quality management, whose versatility makes it easy to use in a number of different context. The paper presents furthermore the findings of the project, the most significant elements of the guidelines for teaching, i.e. the section for teachers, whose aim is to implement a Learning Difficulties-friendly teaching, even at the university level, in compliance with italian Law 170/2010. The Guidelines for the didactic and inclusion of Learning Difficulties students of the University of Florence are articulated around a global and systemic plan of action, meant to accompany and protect the students during their study career, even before enrolling at the University, with different declination: the logistical, relational, educational, and didactic levels have been considered. These guidelines in Italy received the endorsement of the CNUDD. It is a systemic intervention plan for Learning Difficulties students, which roused and keeps rousing the interest of all the university system, with a radical consideration on academic teaching. Since while we try to provide the best Learning Difficulties-friendly didactic in compliance with the rules, no one can be exempted from a wider consideration on the nature and the quality of university teaching offered to all students.Keywords: didactic tools, learning difficulties, special and inclusive education, university teaching
Procedia PDF Downloads 283114 Electrospun Nanofibers from Amphiphlic Block Copolymers and Their Graphene Nanocomposites
Authors: Hussein M. Etmimi, Peter E. Mallon
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Electrospinning uses an electrical charge to draw very fine fibers (typically on the micro or nano scale) from a liquid or molten precursor. Over the years, this method has become a widely used and a successful technique to process polymer materials and their composites into nanofibers. The main focus of this work is to study the electrospinning of multi-phase amphiphilic copolymers and their nanocomposites, which contain graphene as the nanofiller material. In such amphiphilic materials, the constituents segments are incompatible and thus the solid state morphology will be determined by the composition of the various constituents as well as the method of preparation. In this study, amphiphilic block copolymers of poly(dimethyl siloxane) and poly(methyl methacrylate) (PDMS-b-PMMA) with well-defined structures were synthesized and the solution electrospinning of these materials and their properties were investigated. Atom transfer radical polymerization (ATRP) was used to obtain the controlled block copolymers with relatively high molar masses and narrow dispersity. First, PDMS macroinitiators with different chain length of 1000, 5000 and 10000 g/mol were synthesized by the reaction of monocarbinol terminated PDMS with α-bromoisobutyryl bromide initiator. The obtained macroinitiators were used for the polymerization of methyl methacrylate monomer to obtain the desired block copolymers using the ATRP process. Graphene oxide (GO) of different loading was then added to the copolymer solution and the resultant nanocomposites were successfully electrospun into nanofibers. The electrospinning was achieved using dimethylformamide/chloroform mixture (60:40 vl%) as electrospinning solution medium. Scanning electron microscopy (SEM) showed the successful formation of the electrospun fibers with dimensions in the nanometer range. X-ray diffraction indicated that the GO nanosheets were of an exfoliated structure, irrespective of the filler loading. Thermogravimetric analysis also showed that the thermal stability of the nanofibers was improved in the presence of GO, which was not a function of the filler loading. Differential scanning calorimetry also showed that the mechanical properties (measured as glass transition temperature) of the nanofibers was improved significantly in the presence of GO, which was a function of the filler loading.Keywords: elctrospinning, graphene oxide, nanofibers, polymethyl methacrylate (PMMA)
Procedia PDF Downloads 305113 Study the Multifaceted Therapeutic Properties of the IQGAP1shRNA Plasmid on Rat Liver Cancer Model
Authors: Khairy M. A. Zoheir, Nehma A. Ali, Ahmed M. Darwish, Mohamed S. Kishta, Ahmed A. Abd-Rabou, Mohamed A. Abdelhafez, Karima F. Mahrous
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The study comprehensively investigated the multifaceted therapeutic properties of the IQGAP1shRNA plasmid, encompassing its hepatoprotective, immunomodulatory, and anticancer activities. The study employed a Prednisolone-induced immunosuppressed rat model to assess the hepatoprotective and immunomodulatory effects of IQGAP1shRNA plasmid. Using this model, IQGAP1shRNA plasmid was found to modulate haematopoiesis, improving RBC, platelet, and WBC counts, underscoring its potential in hematopoietic homeostasis. Organ atrophy, a hallmark of immunosuppression in spleen, heart, liver, ovaries, and kidneys, was reversed with IQGAP1shRNA plasmid treatment, reinforcing its hepatotrophic and organotropic capabilities. Elevated hepatic biomarkers (ALT, AST, ALP, LPO) indicative of hepatocellular injury and oxidative stress were reduced with GST, highlighting its hepatoprotective and antioxidative effects. IQGAP1shRNA plasmid also restored depleted antioxidants (GSH and SOD), emphasizing its potent antioxidative and free radical scavenging capabilities. Molecular insights into immune dysregulation revealed downregulation of IQGAP1, IQGAP3 interleukin-2 (IL-2), and interleukin-4 (IL-4) mRNA expression in the liver of immunosuppressed rats. IL-2 and IL-4 play pivotal roles in immune regulation, T-cell activation, and B-cell differentiation. Notably, treatment with IQGAP1shRNA plasmid exhibited a significant upregulation of IL-2 and IL-4 mRNA expression, thereby accentuating its immunomodulatory potential in orchestrating immune homeostasis. Additionally, immune dysregulation was associated with increased levels of TNF-α. However, treatment with IQGAP1shRNA plasmid effectively decreased the levels of TNF-α, further underscoring its role in modulating inflammatory responses and restoring immune balance in immunosuppressed rats. Additionally, pharmacokinetics, bioavailability, drug-likeness, and toxicity risk assessment prediction suggest its potential as a pharmacologically favourable agent with no serious adverse effects. In conclusion, this study confirms the therapeutic potential of the IQGAP1shRNA plasmid, showcasing its effectiveness against hepatotoxicity, oxidative stress, immunosuppression, and its notable anticancer activity.Keywords: IQGAP1, shRNA, cancer, liver, rat
Procedia PDF Downloads 3112 Propolis as Antioxidant Formulated in Nanoemulsion
Authors: Rachmat Mauludin, Irda Fidrianny, Dita Sasri Primaviri, Okti Alifiana
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Natural products such as propolis, green tea and corncob are containing several compounds called antioxidant. Antioxidant can be used in topical application to protect skin against free radical, prevent skin cancer and skin aging. Previous study showed that the extract of propolis that has the highest antioxidant activity was ethanolic extract of propolis (EEP). It is important to make a dosage form that could keep the stability and could protect the effectiveness of antioxidant activity of the extracts. In this research, nanoemulsion (NE) was chosen to formulate those natural products. NE is a dispersion system between oil phase and water phase that formed by mechanical force with a lot amount of surfactants and has globule size below 100 nm. In pharmaceutical industries, NE was preferable for its stability, biodegradability, biocompatibility, its ease to be absorbed and eliminated, and for its use as carrier for lipophilic drugs. First, all of the natural products were extracted using reflux methods. Green tea and corncob were extracted using 96% ethanol while propolis using 70% ethanol. Then, the extracts were concentrated using rotavapor to obtain viscous extracts. The yield of EEP was 11.12%; green tea extract (GTE) was 23.37%; and corncob extract (CCE) was 17.23%. EEP contained steroid/triterpenoid, flavonoid and saponin. GTE contained flavonoid, tannin, and quinone while CCE contained flavonoid, phenol and tannin. The antioxidant activities of the extracts were then measured using DPPH scavenging capacity methods. The values of DPPH scavenging capacity were 61.14% for EEP; 97.16% for GTE; and 78.28% for CCE. The value of IC50 for EEP was 0.41629 ppm. After the extracts were evaluated, NE was prepared. Several surfactants and co-surfactants were used in many combinations and ratios in order to form a NE. Tween 80 and Kolliphor RH40 were used as surfactants while glycerin and propylene glycol were used as co-surfactants. The best NE consists of 26.25% of Kolliphor RH40; 8.75% of glycerin; 5% of rice bran oil; 3% of extracts; and 57% of water. EEP NE had globule size around 23.72 nm; polydispersity index below 0.5; and did not cause any irritation on rabbits. EEP NE was proven to be stable after passing stability test within 63 days at room temperature and 6 cycles of Freeze and Thaw test without separated. Based on TEM (Transmission Electron Microscopy) test, EEP NE had spherical structure with most of its size below 50 nm. The antioxidant activity of EEP NE was monitored for 6 weeks and showed no significant difference. The value of DPPH scavenging capacity for EEP NE was around 58%; for GTE NE was 96.75%; and for CCE NE was 55.69%.Keywords: propolis, green tea, corncob, antioxidant, nanoemulsion
Procedia PDF Downloads 321111 Novel Nickel Complex Compound Reactivates the Apoptotic Network, Cell Cycle Arrest and Cytoskeletal Rearrangement in Human Colon and Breast Cancer Cells
Authors: Nima Samie, Batoul Sadat Haerian, Sekaran Muniandy, M. S. Kanthimathi
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Colon and breast cancers are categorized as the most prevalent types of cancer worldwide. Recently, the broad clinical application of metal complex compounds has led to the discovery of potential therapeutic drugs. The aim of this study was to evaluate the cytotoxic action of a selected nickel complex compound (NCC) against human colon and breast cancer cells. In this context, we determined the potency of the compound in the induction of apoptosis, cell cycle arrest, and cytoskeleton rearrangement. HT-29, WiDr, CCD-18Co, MCF-7 and Hs 190.T cell lines were used to determine the IC50 of the compound using the MTT assay. Analysis of apoptosis was carried out using immunofluorescence, acridine orange/ propidium iodide double staining, Annexin-V-FITC assay, evaluation of the translocation of NF-kB, oxygen radical antioxidant capacity, quenching of reactive oxygen species content , measurement of LDH release, caspase-3/-7, -8 and -9 assays and western blotting. The cell cycle arrest was examined using flowcytometry and gene expression was assessed using qPCR array. Results showed that our nickel complex compound displayed a potent suppressive effect on HT-29, WiDr, MCF-7 and Hs 190.T after 24 h of treatment with IC50 value of 2.02±0.54, 2.13±0.65, 3.76±015 and 3.14±0.45 µM respectively. This cytotoxic effect on normal cells was insignificant. Dipping in the mitochondrial membrane potential and increased release of cytochrome c from the mitochondria indicated induction of the intrinsic apoptosis pathway by the nickel complex compound. Activation of this pathway was further evidenced by significant activation of caspase 9 and 3/7.The nickel complex compound (NCC) was also shown activate the extrinsic pathways of apoptosis by activation of caspase-8 which is linked to the suppression of NF-kB translocation to the nucleus. Cell cycle arrest in the G1 phase and up-regulation of glutathione reductase, based on excessive ROS production were also observed. The results of this study suggest that the nickel complex compound is a potent anti-cancer agent inducing both intrinsic and extrinsic pathways as well as cell cycle arrest in colon and breast cancer cells.Keywords: nickel complex, apoptosis, cytoskeletal rearrangement, colon cancer, breast cancer
Procedia PDF Downloads 313110 Vancomycin Resistance Enterococcus and Implications to Trauma and Orthopaedic Care
Authors: O. Davies, K. Veravalli, P. Panwalkar, M. Tofighi, P. Butterick, B. Healy, A. Mofidi
Abstract:
Vancomycin resistant enterococcus infection is a condition that usually impacts ICUs, transplant, dialysis, and cancer units, often as a nosocomial infection. After an outbreak in the acute trauma and orthopaedic unit in Morriston hospital, we aimed to access the conditions that predispose VRE infections in our unit. Thirteen cases of VRE infection and five cases of VRE colonisations were identified in patients who were treated for orthopaedic care between 1/1/2020 and 1/11/2021. Cases were reviewed to identify predisposing factors, specifically looking at age, presenting condition and treatment, presence of infection and antibiotic care, active haemo-oncological condition, long term renal dialysis, previous hospitalisation, VRE predisposition, and clearance (PREVENT) scores, and outcome of care. The presenting condition, treatment, presence of postoperative infection, VRE scores, age was compared between colonised and the infected cohort. VRE type in both colonised and infection group was Enterococcus Faecium in all but one patient. The colonised group had the same age (T=0.6 P>0.05) and sex (2=0.115, p=0.74), presenting condition and treatment which consisted of peri-femoral fixation or arthroplasty in all patients. The infected group had one case of myelodysplasia and four cases of chronic renal failure requiring dialysis. All of the infected patient had sustained an infected complication of their fracture fixation or arthroplasty requiring reoperation and antibiotics. The infected group had an average VRE predisposition score of 8.5 versus the score of 3 in the colonised group (F=36, p<0.001). PREVENT score was 7 in the infected group and 2 in the colonised group(F=153, p<0.001). Six patients(55%) succumbed to their infection, and one VRE infection resulted in limb loss. In the orthopaedic cohort, VRE infection is a nosocomial condition that has peri-femoral predilection and is seen in association with immunosuppression or renal failure. The VRE infection cohort has been treated for infective complication of original surgery weeks prior to VRE infection. Based on our findings, we advise avoidance of infective complications, change of practice in use of antibiotics and use radical surgery and surveillance for VRE infections beyond infective precautions. PREVENT score shows that the infected group are unlikely to clear their VRE in the future but not the colonised group.Keywords: surgical site infection, enterococcus, orthopaedic surgery, vancomycin resistance
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