Search results for: nuclear activity

Authors: Leila Maleki, Ahmad Esmali Kooraneh, Hossein Taghi Derakhshi

Abstract:

Neural activity in the human brain starts from the early stages of prenatal development. This activity or signals generated by the brain are electrical in nature and represent not only the brain function but also the status of the whole body. At the present moment, three methods can record functional and physiological changes within the brain with high temporal resolution of neuronal interactions at the network level: the electroencephalogram (EEG), the magnet oencephalogram (MEG), and functional magnetic resonance imaging (fMRI); each of these has advantages and shortcomings. EEG recording with a large number of electrodes is now feasible in clinical practice. Multichannel EEG recorded from the scalp surface provides a very valuable but indirect information about the source distribution. However, deep electrode measurements yield more reliable information about the source locations، Intracranial recordings and scalp EEG are used with the source imaging techniques to determine the locations and strengths of the epileptic activity. As a source localization method, Low Resolution Electro-Magnetic Tomography (LORETA) is solved for the realistic geometry based on both forward methods, the Boundary Element Method (BEM) and the Finite Difference Method (FDM). In this paper, we review The findings EEG- LORETA about epilepsy.

Keywords: epilepsy, EEG, EEG-LORETA

Procedia PDF Downloads 545

Authors: Karima Oldyerou, B. Meddah, A. Tirtouil

Abstract:

Laurusnobilis is an aromatic plant, common in Algeria and widely used by local people as a source of spice and for medicinal purposes. The essential oil of this plant is the subject of this work in a physicochemical and microbiological study. The extraction of the essential oil was carried by steam distillation and the highest yield (1.5%) was determined in May. The organoleptic and physico-chemical characters are consistent with those obtained in the literature with some differences that can be attributed to certain factors. Evaluation of antibacterial activity showed a sensitivity of Salmonella spp. with an MIC of 2,5 mg.ml-1, and other bacteria of the intestinal flora of Wistar rats: E. coli and Lactobacillus sp. have a high potential for resistance with MICs respectively equal to 10 and 20 mg.ml-1.

Keywords: laurus nobilis, essential oil, physicochemical character, MIC, intestinal flora, antibacterial activity

Procedia PDF Downloads 335

Authors: Jacky Bhagat, Baban S Ingole

Abstract:

In this study, in vivo experiments were carried out to investigate the effects of a toxic polycyclic aromatic hydrocarbon (PAH), benzo(k)fluoranthene (B[k]F), on marine gastropod, Morula granulata collected from Goa, west coast of India. Snails were exposed to different concentrations of B(k)F (1, 10, 25 and 50 µg/L) for 96 h. The genotoxic effects were evaluated by measuring DNA strand breaks using alkaline comet assay and oxidative stress were measured with the help of battery of biomarkers such as superoxide dismutase (SOD) catalase (CAT), glutathione-s-transferase (GST), and lipid peroxidation (LPO). Concentration-dependent increase in percentage tail DNA (TDNA) was observed in snails exposed to B(k)F. Exposure concentrations above 1 µg/L of B(k)F, showed significant increase in SOD activity and LPO value in snails. After 96 h, SOD activity were found to be doubled for 50 µg/L of B(k)F with reference to control. Significant increase in CAT and GST activity was observed at all exposure conditions at the end of the exposure time. Our study showed that B(k)F induces oxidative stress in snails which further lead to genotoxic damage.

Keywords: benzo(k)fluoranthene, comet assay, gastropod, oxidative stress

Procedia PDF Downloads 344

Authors: Ruslin, R. E. Kartasasmita, M. S. Wibowo, S. Ibrahim

Abstract:

An aphrodisiac is a substance contained in food or drug that can arouse sexual instinct and increase pleasure while working, these substances derived from plants, animals, and minerals. When consuming substances that have aphrodisiac activity and duration can improve the sexual instinct. The natural aphrodisiac effect can be obtained through plants, animals, and minerals. Leonurine compound has aphrodisiac activity, these compounds can be isolated from plants of Leonurus Sp, Sundanese people is known as deundereman, this plant is empirical has aphrodisiac activity and based on the isolation of active compounds from plants known to contain compounds leonurine, so that the compound is expected to have activity aphrodisiac. Leonurine compound can be isolated from plants or synthesized chemically with material dasa siringat acid. Leonurine compound can be obtained commercial and derivatives of these compounds can be synthesized in an effort to increase its activity. This study aims to obtain derivatives leonurine better aphrodisiac activity compared with the parent compound, modified the structure of the compounds in the form leonurin guanidino butyl ester group with butyl amin and bromoetanol. ArgusLab program version 4.0.1 is used to determine the binding energy, hydrogen bonds and amino acids involved in the interaction of the compound PDE5 receptor. The in vivo test leonurine compounds and derivatives as an aphrodisiac ingredients and hormone testosterone levels using 27 male rats Wistar strain and 9 female mice of the same species, ages ranged from 12 weeks rats weighing + 200 g / tail. The test animal is divided into 9 groups according to the type of compounds and the dose given. Each treatment group was orally administered 2 ml per day for 5 days. On the sixth day was observed male rat sexual behavior and taking blood from the heart to measure testosterone levels using ELISA technique. Statistical analysis was performed in this study is the ANOVA test Least Square Differences (LSD) using the program Statistical Product and Service Solutions (SPSS). Aphrodisiac efficacy of the leonurine compound and its derivatives have proven in silico and in vivo test, the in silico testing leonurine derivatives have smaller binding energy derivatives leonurine so that activity better than leonurine compounds. Testing in vivo using rats of wistar strain that better leonurine derivative of this compound shows leonurine that in silico studies in parallel with in vivo tests. Modification of the structure in the form of guanidine butyl ester group with butyl amin and bromoethanol increase compared leonurine compound for aphrodisiac activity, testosterone derivatives of compounds leonurine experienced a significant improvement especial is 1RD compounds especially at doses of 100 and 150 mg/bb. The results showed that the compound leonurine and its compounds contain aphrodisiac activity and increase the amount of testosterone in the blood. The compound test used in this study acts as a steroid precursor resulting in increased testosterone.

Keywords: aphrodisiac dysfunction erectile leonurine 1-RD 2-RD, dysfunction, erectile leonurine, 1-RD 2-RD

Procedia PDF Downloads 279

Authors: Supakorn Tantisriyanurak, Hussaya Maneesuwan, Thanyalak Chaisuwan, Sujitra Wongkasemjit

Abstract:

TUD-1 is a siliceous mesoporous material with a three-dimensional amorphous structure of random, interconnecting pores, large pore size, high surface area (400-1000 m2/g), hydrothermal stability, and tunable porosity. However, the significant disadvantage of the mesoporous silicates is few catalytic active sites. In this work, a series of bimetallic Fe and Ti incorporated into TUD-1 framework is successfully synthesized by sol–gel method. The synthesized Fe,Ti-TUD-1 is characterized by various techniques. To study the catalytic activity of Fe, Ti–TUD-1, phenol hydroxylation was selected as a model reaction. The amounts of residual phenol and oxidation products were determined by high performance liquid chromatography coupled with UV-detector (HPLC-UV).

Keywords: iron, phenol hydroxylation, titanium, TUD-1

Procedia PDF Downloads 258

Authors: Qiushi Ning

Abstract:

The nitrogen (N) is an important limiting factor of various ecosystems, and the N deposition rate is increasing unprecedentedly due to anthropogenic activities. The N deposition altered the microbial growth and activity, and microbial mediated N cycling through changing soil pH, the availability of N and carbon (C). The CO2, CH4 and N2O are important greenhouse gas which threaten the sustainability and function of the ecosystem. With the prolonged and increasing N enrichment, the soil acidification and C limitation will be aggravated, and the microbial biomass will be further declined. The soil acidification and lack of C induced by N addition are argued as two important factors regulating the microbial activity and growth, and the studies combined soil acidification with lack of C on microbial community are scarce. In order to restore the ecosystem affected by chronic N loading, we determined the responses of microbial activity and GHG emssions to lime and glucose (control, 1‰ lime, 2‰ lime, glucose, 1‰ lime×glucose and 2‰ lime×glucose) addition which was used to alleviate the soil acidification and supply C resource into soils with N addition rates 0-50 g N m–2yr–1. The results showed no significant responses of soil respiration and microbial biomass (MBC and MBN) to lime addition, however, the glucose substantially improved the soil respiration and microbial biomass (MBC and MBN); the cumulative CO2 emission and microbial biomass of lime×glucose treatments were not significantly higher than those of only glucose treatment. The glucose and lime×glucose treatments reduced the net mineralization and nitrification rate, due to inspired microbial growth via C supply incorporating more inorganic N to the biomass, and mineralization of organic N was relatively reduced. The glucose addition also increased the CH4 and N2O emissions, CH4 emissions was regulated mainly by C resource as a substrate for methanogen. However, the N2O emissions were regulated by both C resources and soil pH, the C was important energy and the increased soil pH could benefit the nitrifiers and denitrifiers which were primary producers of N2O. The soil respiration and N2O emissions increased with increasing N addition rates in all glucose treatments, as the external C resource improved microbial N utilization. Compared with alleviated soil acidification, the improved availability of C substantially increased microbial activity, therefore, the C should be the main limiting factor in long-term N loading soils. The most important, when we use the organic C fertilization to improve the production of the ecosystems, the GHG emissions and consequent warming potentials should be carefully considered.

Keywords: acidification and C limitation, greenhouse gas emission, microbial activity, N deposition

Procedia PDF Downloads 305

Authors: Muhammad Mukhtar

Abstract:

The aim of this study is to evaluate the antioxidant activity and acute toxicity of the extracts of Ficus iteophylla by reactions with 1, 1-diphenyl-2-picryhydrazyl radical (DPPH) and method developed by Lork 1983, respectively. Stem bark of Ficus iteophylla was collected, air dried, pulverized to fine powdered and sequentially extracted using acetone, methanol and water in order of increasing polarity. The result shows strong radical scavenging activity against DPPH for all the extracts when compared with ascorbic acid. The LD50 of 316 mg/kg was calculated for all the three extras, and the values were found to be within the practically toxic range, and therefore, care should be taken when using the plants in traditional medicine.

Keywords: antioxidant, acute toxicity, Ficus iteophylla

Procedia PDF Downloads 160

Authors: Carlos G. Santos, Frederico A. Genezini, A. P. Dos Santos, H. Yorivaz, P. T. D. Siqueira

Abstract:

The Prompt-Gamma Activation Analysis (PGAA) is a valuable technique for investigating the elemental composition of various samples. However, the installation of a PGAA system entails specific conditions such as filtering the neutron beam according to the target and providing adequate shielding for both users and detectors. These requirements incur substantial costs, exceeding $100,000, including manpower. Nevertheless, a cost-effective approach involves leveraging an existing neutron beam facility to create a hybrid system integrating PGAA and Neutron Tomography (NT). The IEA-R1 nuclear reactor at IPEN/USP possesses an NT facility with suitable conditions for adapting and implementing a PGAA device. The NT facility offers a thermal flux slightly colder and provides shielding for user protection. The key additional requirement involves designing detector shielding to mitigate high gamma ray background and safeguard the HPGe detector from neutron-induced damage. This study employs Monte Carlo simulations with the MCNP6 code to optimize the collimator plug for PGAA within the IEA-R1 NT facility. Three collimator models are proposed and simulated to assess their effectiveness in shielding gamma and neutron radiation from nucleon fission. The aim is to achieve a focused prompt-gamma signal while shielding ambient gamma radiation. The simulation results indicate that one of the proposed designs is particularly suitable for the PGAA-NT hybrid system.

Keywords: MCNP6.1, neutron, prompt-gamma ray, prompt-gamma activation analysis

Procedia PDF Downloads 75

Authors: Tita Nofianti, Tresna Lestari, Ade Y. Aprillia, Lilis Tuslinah, Ruswanto Ruswanto

Abstract:

Nanoparticle technology gives a chance for drugs, especially natural based product, to give better activities than in its macromolecule form. The ginger torch is known to have activities as an antioxidant, antimicrobial, anticancer, etc. In this research, ginger torch flower extract was nanoparticlized using poloxamer 1, 3, and 5%. Nanoparticle was charaterized for its particle size, polydispersity index, zeta potential, entrapment efficiency, and morphological form by SEM (scanning electron microscope). The result shows that nanoparticle formulations have particle size 134.7-193.1 nm, polydispersity index is less than 0.5 for all formulations, zeta potential is -41.0 to (-24.3) mV, and entrapment efficiency is 89.93 to 97.99 against flavonoid content with a soft surface and spherical form of particles. Methanolic extract of ginger torch flower could enhance superoxide dismutase activity by 1,3183 U/mL in male rats. Nanoparticle formulation of ginger torch extract is expected to increase the capability of drug to enhance superoxide dismutase activity.

Keywords: superoxide dismutase, ginger torch flower, nanoparticle, poloxamer

Procedia PDF Downloads 207

Authors: Catherine Wheatley, Emma L. Davies, Helen Dawes

Abstract:

The health benefits of exercise are widely recognised, but numerous interventions have failed to halt a sharp decline in physical activity during early adolescence. Many such projects are underpinned by the Theory of Planned Behaviour, yet this model of rational decision-making leaves variance in behavior unexplained. This study investigated whether the Prototype Willingness Model, which proposes a second, reactive decision-making path to account for spontaneous responses to the social environment, has potential to improve understanding of adolescent exercise behaviour in school by exploring constructs in the model with young people. PE teachers in 4 Oxfordshire schools each nominated 6 pupils who were active in school, and 6 who were inactive, to participate in the study. Of these, 45 (22 male) aged 12-13 took part in 8 focus group discussions. These were transcribed and subjected to deductive thematic analysis to search for themes relating to the prototype willingness model. Participants appeared to make rational decisions about commuting to school or attending sports clubs, but spontaneous choices to be inactive during both break and PE. These reactive decisions seemed influenced by a social context described as more ‘judgmental’ than primary school, characterised by anxiety about physical competence, negative peer evaluation and inactive playground norms. Participants described their images of typical active and inactive adolescents: active images included negative social characteristics including ‘show-off’. There was little concern about the long-term risks of inactivity, although participants seemed to recognise that physical activity is healthy. The Prototype Willingness Model might more fully explain young adolescents’ physical activity in school than rational behavioural models, indicating potential for physical activity interventions that target social anxieties in response to the changing playground environment. Images of active types could be more complex than earlier research has suggested, and their negative characteristics might influence willingness to be active.

Keywords: adolescence, physical activity, prototype willingness model, school

Procedia PDF Downloads 346

Authors: Ae Ra Han, Taek Hoo Lee, Sun Zoo Kim, Hwa Young Lee

Abstract:

Introduction: Ovarian endometrioma is one of the important causes of poor ovarian reserve and up to half of them have recurred. However, the treatment for recurrence prevention has limited efficiency and repeated surgical management makes worsen the ovarian reserve. To find better management for recurrence prevention, we investigated risk factors and biomarkers for the recurrence of ovarian endometrioma. Methods: The medical records of women with the history of surgical dissection for ovarian endometrioma were collected. After exclusion of the cases with concurrent hysterectomy, been menopaused during follow-up, incomplete medical record, and loss of follow-up, a total of 134 women were enrolled. Immunohistochemical staining for progesterone receptor isoform B (PR-B) and nuclear factor kappa B (NFκB) was done with the fixed tissue blocks of their endometriomas which were collected at the time of surgery. Results: Severity of dysmenorrhea and co-existence of adenomyosis had significant correlation with recurrence of endometrioma. Increased PR-B (P = .041) and decreased NFκB (P = .036) immunoreactivity were found in recurrent group. Serum CA-125 level at the time of recurrence was higher than the highest level of CA-125 during follow-up in unrecurred group (55.6 vs. 21.3 U/mL, P = .014). Conclusion: We found that the severity of dysmenorrhea and coexistence of adenomyosis are risk factors for recurrence of ovarian endometrioma, and serial follow-up of CA-125 is effective to detect and prevent the recurrence. However, to determine the possibility of immunoreactivity of PR-B and NFκB as biomarkers for ovarian endometrioma, further studies of various races and large numbers with prospective design are needed.

Keywords: endometriosis, recurrence, biomarker, risk factor

Procedia PDF Downloads 553

Authors: M. Das, B. P. Sarma, G. Ahmed

Abstract:

Human diet can be a major source of antioxidants. Poly¬phenols, which are organic compounds present in the regular human diet, have good antioxidant property. Most of the diseases are detected too late and that cause irre¬versible damage to the body. Therefore food that forms the natural source of antioxidants can prevent free radi¬cals from damaging our body tissues. Dillenia indica and Garcinia penducalata are two major fruits, easily available in Assam, North eastern Indian state. In the present study, the in vitro antioxi¬dant properties of the fruits of these plants are compared as the decoction of these fruits form a major part of Assamese cuisine. DPPH free radical scavenging activity of the methanol, petroleum ether and water extracts of G. penducalata and D. indica fruits were carried out by the methods of Cotelle A et al. (1996). Different concentrations ranging from 10–110 ug/ml of the extracts were added to 100 uM of DPPH (2,2, Diphenyl-2-picryl hydrazyl) and the absor¬bance was read at 517 nm after incubation. Ascorbic acid was used as the standard. Different concentrations of the methanol, petroleum ether and water extracts of G. penducalata and D. indica fruits were mixed with sodium nitroprusside and incubated. Griess reagent was added to the mixtures and their optical density was read at 546 nm following the method of Marcocci et al. (1994). Ascorbic acid was used as the standard. In order to find the scavenging activity of the extracts against hydroxyl radicals, the method of Kunchandy & Ohkawa (1990) was followed.The superoxide scavenging activity of the methanol, petroleum ether and water extracts of the fruits was deter¬mined by the method of Robak & Gryglewski (1998).Six replicates were maintained in each of the experiments and their SEM was evaluated based on which, non linear regres¬sion (curve fit), exponential growth were derived to calculate the IC50 values of the SAWE and standard compounds. All the statistical analyses were done by using paired t test. The hydroxyl radical scavenging activity of the various extracts of D. indica exhibited IC50 values < 110 ug/ml concentration, the scavenging activity of the extracts of G. penducalata was surprisingly>110 ug/ml.Similarly the oxygen free radical scavenging activity of the different extracts of D. indica exhibited an IC50 value of <110 ug/ml but the methanolic extract of the same exhib¬ited a better free radical scavenging activity compared to that of vitamin C. The methanolic extract of D. indica exhibited an IC50 value better than that of vitamin C. The DPPH scavenging activities of the various extracts of D. indica and G. penducalata were <110 ug/ml but the methanolic extract of D. indica exhibited an IC50 value bet¬ter than that of vitaminc C.The higher amounts of phenolic content in the methanolic extract of D. indica might be one of the major causes for its enhanced in vitro antioxidant activity.The present study concludes that Dillenia indica and Garcinia penducalata both possesses anti oxidant activi¬ties. The anti oxidant activity of Dillenia indica is superior to that of Garcinia penducalata due to its higher phenolic content

Keywords: antioxidants, free radicals, phenolic, scavenging

Procedia PDF Downloads 595

Authors: N. Benhabyles, K. Arab, O. Bouchenak, A. Baz

Abstract:

The hypoglycemic and antihyperglycemic effects of flavonoids rich extract obtained from leaves of Olea europaea L. was analyzed in normal and alloxan induced diabetic rats. The extraction was performed by confrontation with organic solvents method, which yielded four extracts: Di ethyl Ether, Ethyl Acetate, Butanolic, and Aqueous extract. A single oral dose of 100 mg/kg of the different extract was evaluated for hypoglycemic activity in a glucose tolerance test in normal rats and 200 mg/kg, 400 mg/kg, 600 mg/kg of AE for anti-hyperglycemic activity in alloxan-induced (125 mg/kg) diabetic rats. Dosage of 100 mg/kg of the extract significantly decreased (p<0.05) blood glucose levels in the glucose tolerance test after 120 min. However, a better activity is obtained with the AE. For the anti-hyperglycemic study, the results showed a substantial decrease in blood glucose during the 2 h of treatment for all groups treated with different doses of flavonoids. From the results it can be concluded that flavonoids of O. europaea can be a potential candidate in treating the hyperglycemic conditions.

Keywords: alloxan, antihyperglycemic effect, diabetes mellitus, flavonoids, hypoglycemic effect, Olea europaea L.

Procedia PDF Downloads 373

Authors: M. Roberts

Abstract:

We Are Undefeatable - is a mass marketing behaviour change campaign that aims to support the least active people living with long term health conditions to be more active. This is an important issue to address because people with long term conditions are an historically underserved community for the sport and physical activity sector and the least active of those with long term conditions have the most to gain in health and wellbeing benefits. The campaign has generated a significant change in the way physical activity is communicated and people with long term conditions are represented in the media and marketing. The goal is to create a social norm around being active. The campaign is led by a unique partnership of organisations: the Richmond Group of Charities (made up of Age UK, Alzheimer’s Society, Asthma + Lung UK, Breast Cancer Now, British Heart Foundation, British Red Cross, Diabetes UK, Macmillan Cancer Support, Rethink Mental Illness, Royal Voluntary Service, Stroke Association, Versus Arthritis) along with Mind, MS Society, Parkinson’s UK and Sport England, with National Lottery Funding. It is underpinned by the COM-B model of behaviour change. It draws on the lived experience of people with multiple long term conditions to shape the look and feel of the campaign and all the resources available. People with long term conditions are the campaign messengers, central to the ethos of the campaign by telling their individual stories of overcoming barriers to be active with their health conditions. The central messaging is about finding a way to be active that works for the individual. We Are Undefeatable is evaluated through a multi-modal approach, including regular qualitative focus groups and a quantitative evaluation tracker undertaken three times a year. The campaign has highlighted the significant barriers to physical activity for people with long term conditions. This has changed the way our partnership talks about physical activity but has also had an impact on the wider sport and physical activity sector, prompting an increasing departure from traditional messaging and marketing approaches for this audience of people with long term conditions. The campaign has reached millions of people since its launch in 2019, through multiple marketing and partnership channels including primetime TV advertising and promotion through health professionals and in health settings. Its diverse storytellers make it relatable to its target audience and the achievable activities highlighted and inclusive messaging inspire our audience to take action as a result of seeing the campaign. The We Are Undefeatable campaign is a blueprint for physical activity campaigns; it not only addresses individual behaviour change but plays a role in addressing systemic barriers to physical activity by sharing the lived experience insight to shape policy and professional practice.

Keywords: behaviour change, long term conditions, partnership, relatable

Procedia PDF Downloads 65

Authors: Mayesha Tahsin, A.S. Mollah

Abstract:

Recently, a 1.5x1.5 inch NaI(Tl) detector based gamma-ray spectroscopy system has been installed in the laboratory of the Nuclear Science and Engineering Department of the Military Institute of Science and Technology for radioactivity detection purposes. The newly installed NaI(Tl) detector has a circular lead shield of 22 mm width. An important consideration of any gamma-ray spectroscopy is the minimization of natural background radiation not originating from the radioactive sample that is being measured. Natural background gamma-ray radiation comes from naturally occurring or man-made radionuclides in the environment or from cosmic sources. Moreover, the main problem with this system is that it is not suitable for measurements of radioactivity with a large sample container like Petridish or Marinelli beaker geometry. When any laboratory installs a new detector or/and new shield, it “must” first carry out quality and performance tests for the detector and shield. This paper describes a new portable shielding system with lead that can reduce the background radiation. Intensity of gamma radiation after passing the shielding will be calculated using shielding equation I=Ioe-µx where Io is initial intensity of the gamma source, I is intensity after passing through the shield, µ is linear attenuation coefficient of the shielding material, and x is the thickness of the shielding material. The height and width of the shielding will be selected in order to accommodate the large sample container. The detector will be surrounded by a 4π-geometry low activity lead shield. An additional 1.5 mm thick shield of tin and 1 mm thick shield of copper covering the inner part of the lead shielding will be added in order to remove the presence of characteristic X-rays from the lead shield.

Keywords: shield, NaI (Tl) detector, gamma radiation, intensity, linear attenuation coefficient

Procedia PDF Downloads 158

Authors: Bercem Kiran-Yildirim, Volker Gaukel

Abstract:

Ice recrystallization (IR) which occurs especially during frozen storage is an undesired process due to the possible influence on the quality of products. As a result of recrystallization, the total volume of ice remains constant, but the size, number, and shape of ice crystals change. For instance, as indicated in the literature, the size of ice crystals in ice cream increases due to recrystallization. This results in texture deterioration. Therefore, the inhibition of ice recrystallization is of great importance, not only for food industry but also for several other areas where sensitive products are stored frozen, like pharmaceutical products or organs and blood in medicine. Ice-binding proteins (IBPs) have the unique ability to inhibit ice growth and in consequence inhibit recrystallization. This effect is based on their ice binding affinity. In the presence of IBP in a solution, ice crystal growth is inhibited during temperature decrease until a certain temperature is reached. The melting during temperature increase is not influenced. The gap between melting and freezing points is known as thermal hysteresis (TH). In literature, the TH activity is usually investigated under laboratory conditions in IBP buffer solutions. In product applications (e.g., food) there are many other solutes present which may influence the TH activity. In this study, a subset of IBPs, so-called antifreeze proteins (AFPs), is used for the investigation of the influence of sucrose solution concentration on the TH activity. For the investigation, a polarization microscope (Nikon Eclipse LV100ND) equipped with a digital camera (Nikon DS-Ri1) and a cold stage (Linkam LTS420) was used. In a first step, the equipment was established and validated concerning the accuracy of TH measurements based on literature data.

Keywords: ice binding proteins, ice crystals, sucrose solution, thermal hysteresis

Procedia PDF Downloads 185

Authors: Ga-Young Lee, Hyun-Man Kim

Abstract:

The modulation of the cell-cell junction is critical in epithelial-mesenchymal transition during tumorigenesis. As RhoA activity is known to be up-regulated to dissociate cell-cell junction by contracting acto-myosin complex in various cancer cells, the present study investigated if RhoA activity was also associated with the disruption of the cell-cell junction of oral cancer cells. We studied SCC-25 cells which are established from oral squamous cell carcinoma if their E-cadherin junction (ECJ) was under control of RhoA. Interestingly, development of ECJ of SCC-25 cells depended on the amount of fibronectin (FN) coated on the culture dishes. Seeded cells promptly aggregated to develop ECJ on the substrates coated with a low amount of FN, whereas they were retarded in the development of ECJ on the substrates coated with a high amount of FN. However, it was an unexpected finding that total RhoA activity was lower in the dissociated cells on the substrates of high FN than in the aggregated cells on the substrates of low FN. Treating the dissociated cells on the substrates of high FN with LPA, a RhoA activator, promoted the development to ECJ. In contrast, treating the aggregated cells on the substrates of low FN with Clostridium botulinum C3, a toxin decreasing RhoA activity, dissociated cells concomitant with the disruption of ECJ. Genetical knockdown of RhoA expression by transfecting RhoA siRNA also down-regulated the development of ECJ in SCC-25 cells. Furthermore, PMA, an activator of protein kinase C (PKC), down-regulated the development of ECJ junction of SCC-25 cells on the substrates coated with low FN. In contrast, GO6976, a PKC inhibitor, up-regulated the development of ECJ of SCC-25 cells with the activation of RhoA on the substrates coated with high FN. In conclusion, in the present study, we demonstrated unexpected results that the activation of RhoA promotes the development of ECJ, whereas the inhibition of RhoA retards the development of ECJ in SCC-25 cells.

Keywords: E-cadherin junction, oral squamous cell carcinoma, PKC, RhoA, SCC-25

Procedia PDF Downloads 332

Authors: Emilia Pietiläinen, Heikki Kyröläinen, Tommi Vasankari, Matti Santtila, Tiina Luukkaala, Kai Parkkola

Abstract:

Working in the military sets special demands on physical fitness, however, reduced physical activity levels among employees in the Finnish Defence Forces (FDF), a trend also being seen among the working-age population in Finland, is leading to reduced physical fitness levels and increased risk of cardiovascular and metabolic diseases, something which also increases human resource costs. Therefore, the aim of the present study was to develop an eHealth intervention using accelerometer- smartphone app feedback technique, telephone counseling and physical activity recordings to increase physical activity of the personnel and thereby improve their health. Specific aims were to reduce stress, improve quality of sleep and mental and physical performance, ability to work and reduce sick leave absences. Employees from six military brigades around Finland were invited to participate in the study, and finally, 260 voluntary participants were included (66 women, 194 men). The participants were randomized into intervention (156) and control groups (104). The eHealth intervention group used accelerometers measuring daily physical activity and duration and quality of sleep for six months. The accelerometers transmitted the data to smartphone apps while giving feedback about daily physical activity and sleep. The intervention group participants were also encouraged to exercise for two hours a week during working hours, a benefit that was already offered to employees following existing FDF guidelines. To separate the exercise done during working hours from the accelerometer data, the intervention group marked this exercise into an exercise diary. The intervention group also participated in telephone counseling about their physical activity. On the other hand, the control group participants continued with their normal exercise routine without the accelerometer and feedback. They could utilize the benefit of being able to exercise during working hours, but they were not separately encouraged for it, nor was the exercise diary used. The participants were measured at baseline, after the entire intervention period, and six months after the end of the entire intervention. The measurements included accelerometer recordings, biochemical laboratory tests, body composition measurements, physical fitness tests, and a wide questionnaire focusing on sociodemographic factors, physical activity and health. In terms of results, the primary indicators of effectiveness are increased physical activity and fitness, improved health status, and reduced sick leave absences. The evaluation of the present scientific reach is based on the data collected during the baseline measurements. Maintenance of the studied outcomes is assessed by comparing the results of the control group measured at the baseline and a year follow-up. Results of the study are not yet available but will be presented at the conference. The present findings will help to develop an easy and cost-effective model to support the health and working capability of employees in the military and other workplaces.

Keywords: accelerometer, health, mobile applications, physical activity, physical performance

Procedia PDF Downloads 196

Authors: Chiagoziem A. Otuechere, Ebenezer O. Farombi

Abstract:

The protective effect of dichloromethane: methanol extract of Pterocarpus mildbraedii (PME), a widely consumed Nigerian leafy vegetable, on the toxicity of propanil was investigated in male rats. Animals were distributed into eight groups of five each. Group 1 served as control and received normal saline while rats in groups 2, 3, and 4 received 100 mg/kg, 200 mg/kg, and 400 mg/kg extract doses respectively. Group 5 rats were orally administered 200 mg/kg propanil while groups 6, 7, and 8 rats were given propanil plus extract. Oral administration of propanil elicited a 14.8%, 5%, 122%, and 78% increase in the activity of serum enzymes; alanine aminotransferase (AST), alanine aminotransferase(ALT), Alkaline phoshatase (ALP) and Gamma glutamyl transferase (ﻻGT). There were also increase in Lactate dehydrogenase (LDH) activity, direct bilirubin and lipid peroxidation levels. Furthermore, PME significantly attenuated the marked hepatic oxidative damage that accompanied propanil treatment. The extract significantly decreased LDH activity and bilirubin levels following propanil treatment. Furthermore, propanil-induced alterations in the activities of antioxidant enzymes: Superoxide dismutase (SOD), catalase (CAT) and glutathione s-transferase (GST) in these rats were modulated by the extract. The percentage DPPH Radical Scavenging Activity of the extract was determined as 55% and compared to those of Gallic acid (49%). Hepatic histology examination further confirmed the damage to the liver as it revealed severe periportal cellular infiltration of the hepatocytes. These biochemical and morphological alterations were attenuated in rats pre-treated with 100 mg/kg and 200 mg/kg doses of the extract. These results suggest that PME possesses protective effect against propanil-induced hepatotoxicity.

Keywords: antioxidant, hepatoprotection, Pterocarpus mildbraedii, propanil

Procedia PDF Downloads 430

Authors: A. K. Tursunova, O. V. Chebonenko, A. Zh. Amirkulova, A. O. Abaildayev, O. A. Sapko, Y. M. Dyo, A. Sh. Utarbaeva

Abstract:

Fusarium solani and its variants cause root and stem rot of plants. Dry rot is the most common disease of potato tubers during storage. The causative agents of fusariosis in contact with plants behave as antagonists, growth stimulants or parasites. The diversity of host-parasite relationships is explained by the parasite’s ability to produce a wide spectrum of biologically active compounds including toxins, enzymes, oligosaccharides, antibiotic substances, enniatins and gibberellins. Many of these metabolites contribute to the creation of compatible relations; others behave as elicitors, inducing various protective responses in plants. An important part of the strategy for developing plant resistance against pathogens is the activation of protein synthesis to produce protective ‘pathogenesis-related’ proteins. The family of PR-proteins known to confer the most protective response is chitinases (EC 3.2.1.14, Cht) and β-1,3-glucanases (EC 3.2.1.39, Glu). PR-proteins also include a large multigene family of peroxidases (EC 1.11.1.7, Pod), and increased activity of Pod and expression of the Pod genes leads to the development of resistance to a broad class of pathogens. Despite intensive research on the role of PR-proteins, the question of their participation in the mechanisms of formation of the F.solani–S.tuberosum pathosуstem is not sufficiently studied. Our aim was to investigate the effect of different classes of F. solani metabolites on the activity of chitinase, β-1,3-glucanases and peroxidases in tubers of Solanum tuberosum. Metabolite culture filtrate (CF) and cytoplasmic components were fractionated by extraction of the mycelium with organic solvents, salting out techniques, dialysis, column chromatography and ultrafiltration. Protein, lipid, carbohydrate and polyphenolic fractions of fungal metabolites were derived. Using enzymatic hydrolysis we obtained oligo glycans from fungal cell walls with different molecular weights. The activity of the metabolites was tested using potato tuber discs (d = 16mm, h = 5mm). The activity of PR-proteins of tubers was analyzed in a time course of 2–24 hours. The involvement of the analysed metabolites in the modulation of both early non-specific and late related to pathogenesis reactions was demonstrated. The most effective inducer was isolated from the CF (fraction of total phenolic compounds including naphtazarins). Induction of PR-activity by this fraction was: chitinase - 340-360%, glucanase - 435-450%, soluble forms of peroxidase - 400-560%, related forms of peroxidase - 215-237%. High-inducing activity was observed by the chloroform and acetonitrile extracts of the mycelium (induction of chitinase and glucanase activity was 176-240%, of soluble and bound forms of peroxidase - 190-400%). The fraction of oligo glycans mycelium cell walls of 1.2 kDa induced chitinase and β-1,3-glucanase to 239-320%; soluble forms and related peroxidase to 198-426%. Oligo glycans cell walls of 5-10 kDa had a weak suppressor effect - chitinase (21-25%) and glucanase (25-28%) activity; had no effect on soluble forms of peroxidase, but induced to 250-270% activity related forms. The CF polysaccharides of 8.5 kDa and 3.1 kDa inhibited synchronously the glucanase and chitinase specific response in step (after 24 hours at 42-50%) and the step response induced nonspecific peroxidase activity: soluble forms 4.8 -5.2 times, associated forms 1.4-1.6 times.

Keywords: fusarium solani, PR-proteins, peroxidase, solanum tuberosum

Procedia PDF Downloads 203

Authors: Kalakotla Shanker, G. Krishna Mohan

Abstract:

Nowadays, nanoparticles are being used in pharmacological studies for their exclusive properties such as small size, more surface area, biocompatibility and enhanced solubility. In view of this, the present study aimed to evaluate the antihyperglycemic potential of biologically synthesized silver nanoparticles (BSSNPs) and Gymnema sylvestre (GS) extract. The SEM and SEM analysis divulges that the BSSNPs were spherical in shape. EDAX spectrum exhibits peaks for the presence of silver, carbon, and oxygen atoms in the range of 1.0-3.1 keV. FT-IR reveals the binding properties of active bio-constituents responsible for capping and stabilizing BSSNPs. The results showed increased blood glucose, huge loss in body weight and downturn in plasma insulin. The GS extract (200 mg/kg, 400 mg/kg), BSSNPs (100 mg/kg, 200 mg/kg) and metformin 50 mg/kg were administered to the diabetic rats. BSSNPs at a dose level of 200 mg/kg (b.wt.p.o.) showed significant inhibition of (p<0.001) blood glucose levels as compared with GS extract treated group. The results obtained from study indicate that the BSSNP shows potent anti-diabetic activity.

Keywords: biological silver nanoparticles, G. sylvetre, gymnemic acid, streptozotocin, Wistar rats, antihyperglycemic activity, anti-hyperlipidemic activity

Procedia PDF Downloads 302

Authors: Young Ik Suh, Sanghak Lee, Tae Wook Chung

Abstract:

In recent year, cultural diversity has acquired increasing attentions in our society due to the cultural pluralism and globalization. With the emphasis of diversity in our society, higher education has played a significant role in preparing people to be successful in a diverse world. A number of colleges and universities provide various diversity-related courses that enhance students to recognize the importance of diversity and multiculturalism. However, little research has been conducted with diversity environments in physical activity and sports-related courses to appreciate students’ attitudes toward multiculturalism. Physical activity courses can be regarded as an essential and complementary part of general education. As well, playing and watching certain sports plays a critical role to foster mutual understanding between different races and to help social integration for minority communities. Therefore, it is expected that the appropriate diverse environments in physical activity courses may have a positive impact to the understandings of different cultures and races. The primary purpose of this study is to examine attitudes toward cultural diversity in a physical activity course among undergraduate students. In building on the scholarly foundation in this area, this study applies the established survey scale (e.g., Pluralism and Diversity Attitude Assessment [PADAA]) developed by Stanley (1996) and previous literature related to cultural diversity. The PADAA includes 19 questions. The following two research hypotheses were proposed. H1: Students who take a diversity-related physical course (i.e., Taekwondo) will provide positive attitude changes toward their cultural diversity. H2: Students who take a general physical activity course (i.e., Weight Training) will provide no significant attitude changes toward their cultural diversity. To test the research hypotheses, subjects will be selected from the both Taekwondo and Weight Training class at University of West Georgia. In the Taekwondo class, students will learn the history, meaning, basic terminology, and physical skills, which is a Korean martial art and the national sport of Korea. In the Weight Training class, students will not be exposed to any cultural diversity topics. Regarding data analysis, Doubly Multivariate Analysis of Covariance (Doubly MANCOVA), 2 (time period: pre and after) X 2 (diversity-related content exposure: Taekwondo and Weight Training), will be conducted on attitudes toward the cultural diversity with control variables such as gender and age. The findings of this study will add to the body of literature in cultural diversity because this will be the first known attempt to explain the college students’ attitudes toward cultural diversity in a physical activity courses. The expected results will state that the physical activity course focusing on diversity issues will have a positive impact on college students’ attitude toward cultural diversity. This finding will indicate that Universities need to create diverse programs (e.g., study abroad, exchange program, second language courses) and environments so that students can have positive interactions with other groups of races and different cultures. It is also expected that the positive perceptions and attitudes toward cultural diversity will break down cultural barriers and make students be ready for meeting several challenges in a multicultural and global society.

Keywords: cultural diversity, physical activity course, attitude, Taekwondo

Procedia PDF Downloads 268

Authors: Jeremy J. Johnson

Abstract:

Mediterranean herbs including rosemary (Rosmarinus officinalis) contain a variety of phytochemicals including diterpenes that possess extensive biological activity. Applications of diterpenes, including the more abundant forms carnosol and carnosic acid, have been shown to possess anti-cancer, anti-inflammatory, anti-oxidant, and anti-proliferation properties. To confirm these properties, we have evaluated rosemary extract and selected diterpenes for biological activity in cancer and inflammatory models. Our preliminary data have revealed that select diterpenes can disrupt androgen receptor functionality in prostate and breast cancer cells. This property is unique among natural products for hormone-responsive cancers. The second area of interest has been evaluating rosemary extract and selected diterpenes for activation of sestrin-2, an antioxidant protein, in colon cancer cells. A combination of in vitro and in vivo approaches have been utilized to characterize the activity of rosemary diterpenes in rosemary. Taken together, these results suggest that phytochemicals found in rosemary have distinct pharmacological actions for disrupting cell-signaling pathways in cancer and inflammatory bowel disease.

Keywords: rosemary, diterpene, cancer, inflammation

Procedia PDF Downloads 146

Authors: Emma O’ Keeffe, Helen Hughes, Peter McLoughlin, Shiau Pin Tan, Nick McCarthy

Abstract:

Biosecurity is emerging as one of the most important issues facing the agricultural and forestry community. This is as a result of increased invasion from new pests and diseases with the main protocol for dealing with these species being the use of synthetic pesticides. However, these chemicals have been shown to exhibit negative effects on the environment. Seaweeds represent a vast untapped resource of bio-molecules with a broad range of biological activities including pesticidal. This project investigated both the antifungal and antibacterial activity of seaweed species against two problematic root rot fungi, Armillaria mellea and Heterobasidion annosum and ten quarantine bacterial plant pathogens including Xanthomonas arboricola, Xanthomonas fragariae, and Erwinia amylovora. Four seaweed species were harvested from the South-East coast of Ireland including brown, red and green varieties. The powdered seaweeds were extracted using four different solvents by liquid extraction. The poisoned food technique was employed to establish the antifungal efficacy, and the standard disc diffusion assay was used to assess the antibacterial properties of the seaweed extracts. It was found that extracts of the green seaweed exhibited antifungal activity against H. annosum, with approximately 50% inhibition compared to the negative control. The protectant activities of the active extracts were evaluated on disks of Picea sitchensis, a plant species sensitive to infection from H. annosum and compared to the standard chemical control product urea. The crude extracts exhibited very similar activity to the 10% and 20% w/v concentrations of urea, demonstrating the ability of seaweed extracts to compete with commercially available products. Antibacterial activity was exhibited by a number of seaweed extracts with the red seaweed illustrating the strongest activity, with a zone of inhibition of 15.83 ± 0.41 mm exhibited against X. arboricola whilst the positive control (10 μg/disk of chloramphenicol) had a zone of 26.5 ± 0.71 mm. These results highlight the potential application of seaweed extracts in the forestry and agricultural industries for use as biopesticides. Further work is now required to identify the bioactive molecules that are responsible for this antifungal and antibacterial activity in the seaweed extracts, including toxicity studies to ensure the extracts are non-toxic to plants and humans.

Keywords: antibacterial, antifungal, biopesticides, seaweeds

Procedia PDF Downloads 173

Authors: Drashti G. Daraji, Rosa E. Moo-Puc, Hitesh D. Patel

Abstract:

Substituted 2-Thioimidazole analogues have been synthesized and confirmed by advanced spectroscopic techniques. Among them, ten compounds have been selected and evaluated for their in vitro anti-cancer activity at the National Cancer Institute (NCI) for testing against a panel of 60 different human tumor cell lines derived from nine neoplastic cancer types. Furthermore, synthesized compounds were tested for their in vitro antiprotozoal activity, and none of them exhibited significant potency against antiprotozoans. It was observed that the tested all compounds seem effective on the UACC-62 melanoma cancer cell line as compared to other cancer cell lines and also exhibited the least potent in the Non-Small Cell Lung Cancer cell line in one-dose screening. In silico studies of these derivatives were carried out by molecular docking techniques and Absorption, Distribution, Metabolism, and Excretion (ADME) using Schrödinger software to find potent B-Raf kinase inhibitor (PDB ID: 3OG7). All the compounds have been performed for docking study; Compound D4 has a good docking score for melanoma cancer as compared with other.

Keywords: anticancer activity, cancer cell line, 2-thio imidazole, one-dose assay, molecular docking

Procedia PDF Downloads 143

Authors: Pratibha Srivastava, Ayyamperumal Jeyaprakash, Gary Steck, Jason Stanley, Leroy Whilby

Abstract:

Exotic, invasive tephritid fruit flies (Diptera: Tephritidae) are a major threat to fruit and vegetable industries in the United States. The establishment of pest fruit fly in the agricultural industries and produce severe ecological and economic impacts on agricultural diversification and trade. Detection and identification of these agricultural pests in a timely manner will facilitate the possibility of eradication from newly invaded areas. Identification of larval stages to species level is difficult, but is required to determine pest loads and their pathways into the United States. The aim of this study is the New World genus, Anastrepha which includes pests of major economic importance. Mitochondrial cytochrome c oxidase I (COI) gene sequences were amplified from Anastrepha fraterculus specimens collected from South America (Ecuador and Peru). Phylogenetic analysis was performed to characterize the Anastrepha fraterculus complex at a molecular level. During phylogenetics analysis numerous nuclear mitochondrial pseudogenes (numts) were discovered in different specimens. The numts are nonfunctional copies of the mtDNA present in the nucleus and are easily coamplified with the mitochondrial COI gene copy by using conserved universal primers. This is problematic for DNA Barcoding, which attempts to characterize all living organisms by using the COI gene. This study is significant for national quarantine use, as morphological diagnostics to separate larvae of the various members remain poorly developed.

Keywords: tephritid, Anastrepha fraterculus, COI, numts

Procedia PDF Downloads 239

Authors: Hani Baek, Gwang Min Sun, Chansun Shin, Sung Ho Ahn

Abstract:

Fast neutron irradiation using nuclear reactors is an effective method to improve switching loss and short circuit durability of power semiconductor (insulated gate bipolar transistors (IGBT) and insulated gate transistors (IGT), etc.). However, not only fast neutrons but also thermal neutrons, epithermal neutrons and gamma exist in the nuclear reactor. And the electrical properties of the IGBT may be deteriorated by the irradiation of gamma. Gamma irradiation damages are known to be caused by Total Ionizing Dose (TID) effect and Single Event Effect (SEE), Displacement Damage. Especially, the TID effect deteriorated the electrical properties such as leakage current and threshold voltage of a power semiconductor. This work can confirm the effect of the gamma irradiation on the electrical properties of 600 V NPT-IGBT. Irradiation of gamma forms lattice defects in the gate oxide and Si-SiO₂ interface of the IGBT. It was confirmed that this lattice defect acts on the center of the trap and affects the threshold voltage, thereby negatively shifted the threshold voltage according to TID. In addition to the change in the carrier mobility, the conductivity modulation decreases in the n-drift region, indicating a negative influence that the forward voltage drop decreases. The turn-off delay time of the device before irradiation was 212 ns. Those of 2.5, 10, 30, 70 and 100 kRad(Si) were 225, 258, 311, 328, and 350 ns, respectively. The gamma irradiation increased the turn-off delay time of the IGBT by approximately 65%, and the switching characteristics deteriorated.

Keywords: NPT-IGBT, gamma irradiation, switching, turn-off delay time, recombination, trap center

Procedia PDF Downloads 155

Authors: Dawit Chankaye

Abstract:

Background: Azadirachta indica is the most versatile medicinal plant known as “the village pharmacy”. The plant is known for its broad spectrum of biological activity in India and various countries throughout history by many different human cultures. The present study was undertaken to determine the antimalarial and antidiabetic properties of the leaf extracts of A. indica grown in Ethiopia when treated in vivo. This work has also been concerned with determining essential oil composition and the antimicrobial activity of the plant in vitro. Methods: Leaf extracts were prepared using three different selected solvents. Standard and clinical isolates were treated with extracts of the leaves of A. indica using the agar well diffusion method. The antimalarial and antidiabetic tests were conducted in vivo in mice. Phytochemical screening was done using various chemical tests, and the volatile oil constituents were determined using gas chromatography-mass spectrometry (GC/MS). Results: In vivo antimalarial activity studies showed 85.23%, 69.01%, and 81.54% suppression of parasitemia for 70% ethanol, acetone, and water extracts, respectively. The extracts collected from the leaves also showed reduced blood sugar levels in alloxan-induced diabetic mice. In addition, the solvent extracts were shown to have an inhibitory effect on the growth of microorganisms under the study. The minimum inhibitory concentration (MIC) ranged from 850 to 1050 µg/ml. Notably, the phytochemical investigation of the ethanol extracts showed the presence of secondary metabolites. Seventeen compounds (mainly sesquiterpenes) that represent 75.45% of the essential oil were characterized by GC/MS analysis. Conclusion: Extracts examined in this study indicated that the leaf of A. indica grown in Ethiopia retained the biological activities demonstrating the extent equivalent to when it was grown in its natural habitat. In addition, phytochemical investigation and GC/MS analysis of volatile oil constituents showed comparable results to those presented in India and elsewhere.

Keywords: Azadirachta indica, vivo, antimalarial activity, antidiabetic activity, alloxan, mice, phytochemical

Procedia PDF Downloads 80

Authors: Ashish Bohre, Blaž Likozar, Saikat Dutta, Dionisios G. Vlachos, Basudeb Saha

Abstract:

Graphene oxide, decorated with surface oxygen functionalities, has emerged as a sustainable alternative to precious metal catalysts for many reactions. Herein, we report for the first time that graphene oxide becomes super active for C-C coupling upon incorporation of multilayer crystalline features, highly oxidized surface, Brønsted acidic functionalities and defect sites on the surface and edges via modified oxidation. The resulting improved graphene oxide (IGO) demonstrates superior activity to commonly used framework zeolites for upgrading of low carbon biomass furanics to long carbon chain aviation fuel precursors. A maximum 95% yield of C15 fuel precursor with high selectivity is obtained at low temperature (60 C) and neat conditions via hydroxyalkylation/alkylation (HAA) of 2-methylfuran (2-MF) and furfural. The coupling of 2-MF with carbonyl molecules ranging from C3 to C6 produced the precursors of carbon numbers 12 to 21. The catalyst becomes inactive in the 4th cycle due to the loss of oxygen functionalities, defect sites and multilayer features; however, regains comparable activity upon regeneration. Extensive microscopic and spectroscopic characterization of the fresh and reused IGO is presented to elucidate high activity of IGO and to establish a correlation between activity and surface and structural properties. Kinetic Monte Carlo (KMC) and density functional theory (DFT) calculations are presented to further illustrate the surface features and the reaction mechanism.

Keywords: methacrylic acid, itaconic acid, biomass, monomer, solid base catalyst

Procedia PDF Downloads 173

Authors: Jinrui Zhang, Tianlong Yang, Ying Pan

Abstract:

Methane and carbon dioxide are major greenhouse gases contributor. CO₂ dry reforming of methane (DRM) for syngas production is a promising approach to reducing global CO₂ emission and extensive utilization of natural gas. However, the reported catalysts endured rapid deactivation due to severe carbon deposition at high temperature. Here, CO₂ reduction by CH4 on hexagonal nano-nickel flakes packed by porous SiO₂ (Ni@SiO₂) catalysts driven by thermal and solar light are tested. High resistance to carbon deposition and higher reactive activity are demonstrated under focused solar light at moderate temperature (400-500 ℃). Furthermore, the photocatalytic DRM under different wavelength is investigated, and even IR irradiation can enhance the catalytic activity. The mechanism of light-enhanced reaction reactivity and equilibrium is investigated by Infrared and Raman spectroscopy, and the unique reaction pathway with light is depicted. The photo-enhanced DRM provides a promising method of renewable solar energy conversion and CO₂ emission reduction due to the excellent activity and durability.

Keywords: CO₂ emission reduction, methane, photocatalytic DRM, resistance to carbon deposition, syngas

Procedia PDF Downloads 115