Search results for: autonomous agents

Authors: Aulina R. Rahmi, Farid Yuristiawan, Annisa Ibifadillah, Ummu H. Amri, Hidayati Gunawan

Abstract:

Glass ionomer cement is one of the filling material that often used on the field of dentistry because it is relatively less expensive and mostly available. Restoration materials could undergo changes in their clinical properties such as changes in roughness of the restoration`s surface. An increase of surface roughness accelerates bacterial colonization and plaque maturation. In the oral cavity, GIC was exposed to various substances, such as toothpaste, an oral care product used during toothbrushing. One of the popular toothpaste is whitening toothpaste. Abrasive and chemical agents such as hydrogen peroxide in whitening toothpaste could increase the surface roughness of restorative materials. Objective: To determine the differences on the surface roughness of glass ionomer cement that was brushed with whitening and conventional toothpaste. Method: This study was done using experimental laboratory method with pre and post test design. There were 36 samples which were divided into 2 groups. The first group was brushed with whitening toothpaste and the second group was brushed with conventional toothpaste, each for 2 minutes. Surface roughness value of the specimens was measured by using Roughness Tester test. Result: The data was analyzed by using independent t-test and the result of this study showed there was a significant difference between the surface of glass ionomer cement which was brushed with whitening and conventional toothpaste (p=0,000). Conclusion: Glass ionomer cement that was brushed with whitening toothpaste produced more roughness than conventional toothpaste.

Keywords: glass ionomer cement, surface roughness, toothpaste, roughness tester

Procedia PDF Downloads 287

Authors: Jamal Alqinai

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A pragmatic approach to translation studies the rules and principles governing the use of language over and above the rules of syntax or morphology, and what makes some uses of language more appropriate than others in [communicative] situations. It attempts to explain translation as a procedure and product from the point of view of how, why and what is done by the source text author (ST) and what is to be done in the target text (TT) rendition. The latter will be subject to evaluation not as generated by the linguistics system but as conveyed and manipulated by participants in a communicative situation according to the referential and pragmatic standards employed. The failure of a purely lexical or structural translation stems from ignoring the relation between words as signs and the effect they have on their users. A more refined approach would also consider those processes that are sometimes labeled extra-linguistic or intuitive and which translators strive to reproduce unscathed in the translation process. We need to grasp the kind of actions an ST author performs on his readers by combining linguistic and non-linguistic elements against a backdrop of beliefs and cultural values. In other words, aside from considering the cohesive ties at the textual level, one needs to understand how the whole ST discourse hangs together logically in order to reproduce a coherent TT. The latter can only be achieved by an analysis of the pragmatic elements of presuppositions, implicatures and acts performed in the ST. Establishing cohesive ties within a text may require seeking reference outside the immediate text. The illocutionary functions manifested in one language/culture are relatively autonomous cultural/linguistic categories, but are imaginable by members of other cultures and, to some extent , are translatable though not, of course, without translation loss. Globalization and the spread of literacy worldwide may have created a universal empathy to comprehend the performative aspect of utterances when explained by approximate glosses or by paraphrase. Yet, it is often the multilayered and the culture-specific nature of illocutionary functions that de-universalize their possible interpretations. This paper addresses the pragmatic interpretation of culturally specific texts with examples adduced from a number of distinct settings to illustrate the influence of the pragmatic factors at stake.

Keywords: pragmatic, presupposition, implicature, cohesion

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Authors: Hye Jin Kim, Hwa Sung Shin

Abstract:

Ischemic stroke means the caused brain damage due to neurological defects, occurring occlusion of cerebral vascular resulting in thrombus or embolism. t-PA (tissue Plasminogen Activator) is the only thrombolytic agent passed the FDA (Food and Drug Administration). However, t-PA directly dissolves the thrombus (direct activity) through fibrinolysis, showing side effects such as re-occlusion. In this study, we evaluated the thrombolytic activities of the serine protease extracted from lugworms inhabiting tidal flats. The new serine protease identified as 38 kDa by SDS-PAGE was not toxic to brain endothelial cells line (hCMEC/D3). Also, the plasmin synthesis inhibition activity (indirect activity) of the new serine protease was confirmed through fibrin zymography assay and fibrin plate assay. It was higher than direct activity as compared to u-PA (urokinase Plasminogen Activator). The activities were found to be maintained at a wide range of temperature (4-70 ℃) and pH 7-10 compared to previous thrombolytic agents from the azocasein assay. In addition, the new serine protease has shown anticoagulant activity from fibrinogenolytic activity assay. In conclusion, the serine protease in lug worms inhabiting the tidal flats could be considered a promising thrombolytic candidate for the treatment of ischemic stroke.

Keywords: alkaline serine protease, bifunctional thrombolytic activity, fibrinolytic activity, ischemic stroke, lug worms

Procedia PDF Downloads 328

Authors: Abasali Masoumi, Amir Gholamian Bozorgi

Abstract:

To have the best quality in wood products such as tabletops and inlay-woods, applying two principles are required: aesthetic and protection against the destructive agent. Artists spent a lot of time creating a masterwork project and also for better demonstrating beautiful appearance and preserving it for hundred years. So they need good material and appropriate method to finish it. As usual, wood painters use polyester or epoxy resins. These finishes need a special skill to use and then give a fantastic paint film and clearness. If we let resins dry in exposure to environmental agents such as unstable temperature, dust and etc., no doubt it becomes cloudy, crack, blister and much wood dust and air bubbles in it. We have designed a special wood coating booth (IR-Patent No: 70429) for wood-coating resins (polyester and epoxy), and this booth provides an adjustable space to control factors that is necessary to have a good finish in the end. Anti-bubble painting booth has the ability to remove bubbles from resin, precludes the cracking process and causes the resin to be the best. With this booth drying time of resin is reduced from 24 hours to 6 hours by fixing the optimum temperature, and it is very good for saving time. This booth is environment-friendly and never lets the poisonous vapors and other VOC (Volatile organic components) enter to workplace atmosphere because they are very harmful to humans.

Keywords: wood coating, epoxy resin, polyester resin, wood finishes

Procedia PDF Downloads 229

Authors: Strahinja Kovacevic, Milica Karadzic Banjac, Jasmina Vitas, Stefan Vukmanovic, Radomir Malbasa, Lidija Jevric, Sanja Podunavac-Kuzmanovic

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The present study deals with chemometric regression analysis of quality parameters and the radical scavenging ability of kombucha fermented kefir-like products obtained with winter savory (WS), peppermint (P), stinging nettle (SN) and wild thyme tea (WT) kombucha inoculums. Each analyzed sample was described by milk fat content (MF, %), total unsaturated fatty acids content (TUFA, %), monounsaturated fatty acids content (MUFA, %), polyunsaturated fatty acids content (PUFA, %), the ability of free radicals scavenging (RSA Dₚₚₕ, % and RSA.ₒₕ, %) and pH values measured after each hour from the start until the end of fermentation. The aim of the conducted regression analysis was to establish chemometric models which can predict the radical scavenging ability (RSA Dₚₚₕ, % and RSA.ₒₕ, %) of the samples by correlating it with the MF, TUFA, MUFA, PUFA and the pH value at the beginning, in the middle and at the end of fermentation process which lasted between 11 and 17 hours, until pH value of 4.5 was reached. The analysis was carried out applying univariate linear (ULR) and multiple linear regression (MLR) methods on the raw data and the data standardized by the min-max normalization method. The obtained models were characterized by very limited prediction power (poor cross-validation parameters) and weak statistical characteristics. Based on the conducted analysis it can be concluded that the resulting radical scavenging ability cannot be precisely predicted only on the basis of MF, TUFA, MUFA, PUFA content, and pH values, however, other quality parameters should be considered and included in the further modeling. This study is based upon work from project: Kombucha beverages production using alternative substrates from the territory of the Autonomous Province of Vojvodina, 142-451-2400/2019-03, supported by Provincial Secretariat for Higher Education and Scientific Research of AP Vojvodina.

Keywords: chemometrics, regression analysis, kombucha, quality control

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Authors: Marcin Dębowski, Mirosław Krzemieniewski, Marcin Zieliński

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This publication presents a device designed to depolymerise and structurally change organic substrate, for use in agricultural biogas plants or sewage treatment plants. The presented device consists of a heated tank equipped with an inlet valve for the crude substrate and an outlet valve for the treated substrate. The system also includes a gas conduit, which is at its tip equipped with a high-pressure solenoid valve and a vacuum relief solenoid valve. A conduit behind the high-pressure solenoid valve connects to the vacuum tank equipped with the outlet valve. The substrate introduced into the device is exposed to agents such as high temperature and cavitation produced by abrupt, short-term reduction of pressure within the heated tank. The combined effect of these processes is substrate destruction rate increase of about 20% when compared to using high temperature alone, and about 30% when compared to utilizing only cavitation. Energy consumption is greatly reduced, as the pressure increase is generated by heating the substrate. Thus, there is a 18% reduction of energy consumption when compared to a device designed to destroy substrate through high temperature alone, and a 35% reduction if compared to using cavitation as the only means of destruction.

Keywords: thermal depolymerisation, organic substrate, biogas, pre-treatment

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Authors: Samy Selim

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Natural products are still major sources of innovative therapeutic agents for various conditions, including infectious diseases. Peganum harmala L. oil had wide range uses as traditional medicinal plants. The current study was designed to evaluate the antibacterial activity of P. harmala essential oil. The chemical constitutes and toxicity of these oils was also determined to obtain further information on the correlation between the chemical contents and antibacterial activity. The antibacterial effect of the essential oils of P. harmala oil was studied against some foodborne pathogenic bacteria species. The oil of plant was subjected to gas chromatography-mass spectrometry (GC/MS). The impact of oils administration on the change in rate of weight gain and complete blood picture in hamsters were investigated. P. harmala oil had strong antibacterial effect against bacterial species especially at minimum inhibitory concentration (MIC) less than 75.0 μg/ml. From the oil of P. harmala, forty one compounds were identified, and the major constituent was 1-hexyl-2-nitrocyclohexane (9.07%). Acute toxicity test was performed on hamsters and showed complete survival after 14 days, and there were no toxicity symptoms occurred. This study demonstrated that these essential oils seemed to be destitute of toxic effect which could compromise the medicinal use of these plants in folk medicine.

Keywords: analysis mass spectrometry, antibacterial activities, acute toxicity, chemical constitutes, gas chromatography, weight gain, Peganum harmala

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Authors: Dalia Jomehpour, Sara Sheikhlary, Esmaeil Heydari, Mohammad Hossien Majles Ara

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In this study, we report fulvic acid-coated iron oxide nanoparticles of 10.7 ± 2.7 nm size, which serve to inhibit amyloid fibrillation formation. Although the effect of fulvic acid on tau fibrils was investigated, to our best knowledge, its inhibitory impacts on amyloid aggregation formation have been assessed neither in-vitro nor in-vivo. On the other hand, iron oxide nanoparticles exhibit anti-amyloid activity on their own. This study investigates the inhibitory effect of fulvic acid coated iron oxide nanoparticles on amyloid aggregations formed from the commonly used in-vitro model, lysozyme from chicken egg white. FESEM, XRD, and FTIR characterization confirmed that fulvic acid was coated onto the surface of the nanoparticles. The inhibitory effects of the fulvic acid coated iron oxide nanoparticles were verified by Thioflavin T assay, circular dichroism (CD), and FESEM analysis. Furthermore, the toxicity of the nanoparticles on the neuroblastoma SH-SY5Y human cell line was assessed through an MTT assay. Our results indicate that fulvic acid coated iron oxide nanoparticles can efficiently inhibit the formation of amyloid aggregations while exhibiting negligible in-vitro toxicity; thus, they can be used as anti-amyloid agents in the development of the potential drug for neurodegenerative diseases.

Keywords: Alzheimer’s disease, fulvic acid coated iron oxide nanoparticles, fulvic acid, amyloid inhibitor, polyphenols

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Authors: Zahra Ebrahimi, Abbas Moradan

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This study investigated the effect of applying different layers of activity for different Iranian intermediate EFL learner’s oral proficiency and two of its components (fluency and accura-cy) for the beneficial use of films within speaking classes. For this purpose, thirty Iranian EFL intermediate learners were selected based on availability sampling, they were divided into one experimental group and one control group, each consisting of 15 participants, who were proved to be homogeneous based on the results obtained from IELTS oral proficien-cy test prior to the treatment. Experimental Group received the treatment which was apply-ing different layers of speaking tasks according to learners’ level of fluency and accuracy. Control group received ordinal treatment of speaking classrooms. The materials for this study consisted of 11 English movies for each session, voice-recorder device, and IELTS oral proficiency tests as well as two interviews based on Ur’s oral scale for measuring fluen-cy and accuracy. The treatment was run for 12 sessions in six weeks. At the end of the treatment, all the students both in experimental and control group were given a post-test interview based on Ur’s scale. To compare and contrast the amount of progress of the learners in different groups the results of the pre-test and post-test of speaking were analysed by using T-tests. Moreover, Multivariate analysis of variance was also used to check the hypotheses. Results showed that application of different layers of activity with regard to students’ level, led to a significantly superior performance in experimental group. Thus, this study verified the positive effect of implementation of different layers of activity and tasks to achieve progress in speaking skill. It can also help to create a less stressful at-mosphere of learning in which all the students will be given specific time to speak and lead them to be autonomous learners.

Keywords: differentiated instruction, learners’ style, multiple intelligence, speaking skill, task-based activities

Procedia PDF Downloads 142

Authors: Kave Moloudi, Heidi Abrahamse, Blassan P. George

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Radiotherapy (RT) and photodynamic therapy (PDT) are both forms of cancer treatment that aim to kill cancer cells while minimizing damage to healthy tissue. The similarity between RT and PDT lies in their mechanism of action. Both treatments use energy to damage cancer cells. RT uses high-energy radiation to damage the DNA of cancer cells, while PDT uses light energy to activate a photosensitizing agent, which produces reactive oxygen species (ROS) that damage the cancer cells. Both treatments require careful planning and monitoring to ensure the correct dose is delivered to the tumor while minimizing damage to surrounding healthy tissue. They are also often used in combination with other treatments, such as surgery or chemotherapy, to improve overall outcomes. However, there are also significant differences between RT and PDT. For example, RT is a non-invasive treatment that can be delivered externally or internally, while PDT requires the injection of a photosensitizing agent and the use of a specialized light source to activate it. Additionally, the side effects and risks associated with each treatment can vary. In this review, we focus on generalizing the 6Rs of radiobiology in PDT, which can open a window for the clinical application of Radio-photodynamic therapy with minimum side effects. Furthermore, this review can open new insight to work on and design new radio-photosensitizer agents in Radio-photodynamic therapy.

Keywords: radiobiology, photodynamic therapy, radiotherapy, 6Rs in radiobiology, ROS, DNA damages, cellular and molecular mechanism, clinical application.

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Authors: Summer Jackson

Abstract:

September 11, 2001 terrorist attacks exposed weaknesses in federal law enforcement’s ability to proactively counter threats to American homeland security. Following the attacks, legislative reforms and policy changes cleared both bureaucratic and legal obstacles to anti-terrorism efforts. The Federal Bureau of Investigation (FBI) transformed into a domestic intelligence agency responsible for preventing future terrorist attacks. Likewise, the passage of the 2001 USA Patriot Act gave federal agents new discretionary powers to more easily collect intelligence on those suspected of supporting terrorism. Despite these changes, there has been only limited scholarly attention paid to terrorism responses by the federal criminal justice system. This study sought to examine the investigative and prosecutorial changes made in the Post-9/11 era. The methodology employed bivariate and multivariate statistics using data from the American Terrorism Study (ATS). This analysis examined how policy changes are reflected in the nature of terrorism investigations, the handling of terrorist defendants by federal prosecutors, and the outcomes of terrorism cases since 2001. The findings indicate significant investigative and prosecutorial changes in the Post-9/11 era. Specifically, this study found terrorism cases involved younger defendants, fewer indictees per case, less use of human intelligence, less complicated attacks, less serious charges, and more plea bargains. Overall, this study highlights the important shifts in responses to terrorism following the 9/11 attacks.

Keywords: terrorism, law enforcement, post-9/11, federal policy

Procedia PDF Downloads 119

Authors: Fui Ping Lim, Wen Choong Chua, Toan Thang Phan

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Aim: This study investigates the roles of Cord Lining Stem Cells (CLSCs) as potential therapeutic agents for diabetic wounds. Method: 20 genetically diabetic db/db mice were randomly assigned to two arms; (i) control group received placebo treatment (sham media or cells delivery material), and (ii) active comparator received CLSCs. Two full-thickness wounds, each sized 10mm X 10mm were created, one on each side of the midline on the back of the mice. Digital pictures were taken on day 1, 3, 7, 10, 14, 17, 21, 24, 28. Wound areas were analyzed with ImageJ TM software and calculated as percentage of the original wound. Time to closure was defined as the day the wound bed was completely epithelized and filled with new tissues. Results: The CLSCs-treated wounds, showed a significant increase in the percentage of wound closure and achieved 100% closure of the wound sooner than the control group by an average of 3.7 days. The mice treated with CLSCs have a shorter wound closure time (mean closure day: 19.8 days) as compared to the control group (mean closure day: 23.5 days). Conclusion: Our preliminary findings inferred that CLSCs treated wound achieved higher percentage of wound closure within a shorter duration of time.

Keywords: cord lining stem cell, diabetic wound, stem cell, wound

Procedia PDF Downloads 285

Authors: Lyanne Rodriguez, Eduardo Fuente, Andrés Trostchansky, Ivan Palomo

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Cardiovascular diseases (CVD) are the leading cause of death in the world. The development of platelet-rich thrombi has been considered a trigger for acute cardiovascular events. A healthy diet, rich in fruit and vegetables, has been related to increased protection against cardiovascular events. Previous studies have observed that tomato pomace has a potent antiplatelet activity, due could be attributed to its high content of fatty acids (> 30%). It has been shown that unsaturated fatty acids can undergo endogenous intracellular nitration reactions during digestion after lipid consumption. Additionally, nitrated fatty acids (NO2-FA) can significantly reduce atherosclerotic lesion formation, inhibiting the expression of adhesion molecules on dysfunctional endothelium and platelet activation. In this work, we have proposed the nitration of fatty acids present in tomato pomace to improve its antiplatelet action. The gastric digestion of the tomato pomace allowed the nitration of the fatty acids, while by HPLC/MS/MS we were able to identify and quantify the nitrated fatty acids. The nitrated tomase extracts showed antiplatelet potential when platelets were stimulated with TRAP-6 and collagen. This activity was related to the presence of nitrated linoleic acid, which inhibited platelet activation by flow cytometry. The knowledge about the antiplatelet activity of nitrated fatty acids from tomato pomace will further develop new and more effective agents.

Keywords: cardiovascular, tomato extracts, nitrated fatty acids, antiplatelet activity

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Authors: Romuald Temomo Wamba, Robert Wanda

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The issue of creative accounting in the psychological and sociological framework has been a mixed subject for over 60 years. The objective of this article is to ensure the existence of creative accounting in Cameroonian entities on the one hand and to understand the strategies used by audit agents to detect errors, omissions, irregularities, or inadequacies in the financial state; optimization techniques used by account preparers to strategically bypass texts on the other hand. To achieve this, we conducted an exploratory study using a cognitive approach, and the data analysis was performed by the software 'decision explorer'. The results obtained challenge the authors' cognition (manifest latent and deceptive behavior). The tax inspectors stress that the entities in Cameroon do not derogate from the rules of piloting in the financial statements. Likewise, they claim a change in current income and net income through depreciation, provisions, inventories, and the spreading of charges over long periods. This suggests the suspicion or intention of manipulating the financial statements. As for the techniques, the account preparers manage the accruals at the end of the year as the basis of the practice of creative accounting. Likewise, management accounts are more favorable to results management.

Keywords: creative accounting, sociocognitive approach, psychological and sociological approach, cognitive dissonance theory, cognitive mapping

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Authors: Ashkan Forootan, Reza Rashedi

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Polyethylene has wide usage areas such as blow molding, pipe, film, cable insulation. However, regardless to its growing applications, it has some constraints such as the limited 70C operating temperature. Polyethylene thermo setting procedure whose molecules are knotted and 3D-molecular-network formed , is developed to conquer the above problem and to raise the applicable temperature of the polymer. This paper reports the cross-linking for two different molecular weight grades of LLDPE by adding 0.5, 1, and 2% of DCP (Dicumyl Peroxide). DCP was chosen for its prevalence among various cross-linking agents. Structural parameters such as molecular weight, melt flow index, comonomer, number of branches,etc. were obtained through the use of relative tests as Gel Permeation Chromatography and Fourier Transform Infra Red spectrometer. After calculating the percentage of gel content, properties of the pure and cross-linked samples were compared by thermal and mechanical analysis with DMTA and FTIR and the effects of cross-linking like viscous and elastic modulus were discussed by using various structural paprameters such as MFI, molecular weight, short chain branches, etc. Studies showed that cross-linked polymer, unlike the pure one, had a solid state with thermal mechanical properties in the range of 110 to 120C and this helped overcome the problem of using polyethylene in temperatures near the melting point.

Keywords: LLDPE, cross-link, structural parameters, DCP, DMTA, GPC

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Authors: Dina Fatmawati, Sofia Mubarika, Mae Sri Wahyuningsih

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Chemotherapy for breast cancer is largely ineffective, but innovative combinations of chemotherapeutic agents and natural compounds represent a promising strategy. In our previous study, the combination of Doxorubicin (Dox) and ethanolic extract of Dioscorea esculenta tuber ((EED) was found to have a synergistic effect on T47D human breast cancer cell line. In this study, we investigated the apoptotic effect of the combination on T47D human breast cancer cells and normal fibroblasts cell line and its effects on the expression of Caspase-3 and cleaved poly (ADP-Ribose) Polymerase-1 (cPARP-1) protein. T47D cell lines and fibroblasts cells were treated with the combination of Dox and EED. Apoptotic effect of the combination was determined using flow cytrometry assay. Protein expressions were determined by immunocytochemistry staining. The percentage of apoptotic cells were significantly higher in T47D cell lines (75%) than that of in fibroblast cells (23%). The expression of Caspase 3 (84.53%) and cPARP-1 (83.36%) were significantly higher in the cancer cell lines than those of normal cells. These results indicate that the combination of doxorubicin and Dioscorea esculenta is a promising candidate for the treatment of breast cancer cells.

Keywords: Dioscorea esculenta, Doxorubicin, apoptosis, immunocytochemistry, cancer cells

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Authors: Ali Afaghi, Sehraneh Ghaemi

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The coordination of the multi-agent systems has been one of the interesting topic in recent years, because of its potential applications in many branches of science and engineering such as sensor networks, flocking, underwater vehicles and etc. In the most of the related studies, it is assumed that the dynamics of the multi-agent systems are integer-order and linear and the multi-agent systems with the fractional-order nonlinear dynamics are rarely considered. However many phenomena in nature cannot be described within integer-order and linear characteristics. This paper investigates the leader-following consensus problem for a class of nonlinear fractional-order multi-agent systems based on observer-based cooperative control. In the system, the dynamics of each follower and leader are nonlinear. For a multi-agent system with fixed directed topology firstly, an observer-based consensus protocol is proposed based on the relative observer states of neighboring agents. Secondly, based on the property of the stability theory of fractional-order system, some sufficient conditions are presented for the asymptotical stability of the observer-based fractional-order control systems. The proposed method is applied on a five-agent system with the fractional-order nonlinear dynamics and unavailable states. The simulation example shows that the proposed scenario results in the good performance and can be used in many practical applications.

Keywords: fractional-order multi-agent systems, leader-following consensus, nonlinear dynamics, directed graphs

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Authors: Dagim Ali Hussen, Adnan A. Bekhit, Ariaya Hymete

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In this study, several pyridine derivatives were synthesized and evaluated for their in vitro antimicrobial activity against gram-positive bacteria (S. aureus and B. Cereus), gram-negative bacteria (P. aeruginosa and E. coli) and fungus (C. albican and A niger). The intermediate chalcone derivative 2a,b was synthesized by condensation of pyrazole aldehydes 1a,b with acetophenone in alcoholic KOH. Cyclization of 2a,b with ethyl cyanoacetate ad ammonium acetate resulted in pyridine carbonitrile derivatives 3a,b. Furthermore, condensation of pyridine-4-carboxaldeyhe with different amino-derivatives gave rise to pyridine derivatives 5a,b, 6a,b. The oxadiazole derivative 7a was prepared by cyclization of 6a with acetic anhydride. Characterization of the synthesized compound was performed using IR, 1H NMR, 13C NMR spectra and elemental microanalyses. The antimicrobial results revealed that compounds 5a, 6b and 7a exhibited half fold antibacterial activity compared to ampicillin, against B. cereus. On the other hand, compound 3b showed an equivalent activity compared to miconazole against candida albican (CANDAL 03) and to clotrimazole against the clinical isolate candida albican 6647. Moreover, this compound 3b was further tested for its acute toxicity profile. The results showed that oral LD50 is more that 300 mg/kg and parentral LD50 is more than 100 mg/kg. Compound 3b is a good candidate for antifungal agent with good toxicity profile, and deserves more chemical derivatization and clinical study.

Keywords: antifungal, antimicrobial, Candida albican, pyridine

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Authors: Shuafeng Yuan, Bojian Zheng

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The RNA-dependent RNA polymerase of influenza a virus comprises conserved and independently folded subdomains with defined functionalities. The N-terminal domain of the PA subunit (PAN) harbors the endonuclease function so that it can serve as a desired target for drug discovery. To identify a class of anti-influenza inhibitors that impedes PAN endonuclease activity, a screening approach that integrated the fluorescence resonance energy transfer based endonuclease inhibitor assay with the DNA gel-based endonuclease inhibitor assay was conducted, followed by the evaluation of antiviral efficacies and potential cytotoxicity of the primary hits in vitro and in vivo. A small-molecule compound ANA-0 was identified as a potent inhibitor against the replication of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9 and H9N2, in cell cultures. Combinational treatment of zanamivir and ANA-0 exerted synergistic anti-influenza effect in vitro. Intranasal administration of ANA-0 protected mice from lethal challenge and reduced lung viral loads in H1N1 virus infected BALB/c mice. Docking analyses predicted ANA-0 bound the endonuclease cavity of PAN by interacting with the metal-binding and catalytic residues. In summary, ANA-0 shows potential to be developed to novel anti-influenza agents.

Keywords: anti-influenza, novel compound, inhibition of endonuclease, PA

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Authors: Babatunde Oluwole Ogunsile, Omosola Monisola Fasoranti

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High costs and toxicological hazards associated with the physicochemical methods of producing nanoparticles have limited their widespread use in clinical and biomedical applications. An ethically sound alternative is the utilization of plant bioresources as a low cost and eco–friendly biological approach. Silver nanoparticles (AgNPs) were synthesized from aqueous leaf extract of Tithonia diversifolia plant. The UV-Vis Spectrophotometer was used to monitor the formation of the AgNPs at different time intervals and different ratios of plant extract to the AgNO₃ solution. The biosynthesized AgNPs were characterized by FTIR, X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). Antimicrobial activities of the AgNPs were investigated against ten human pathogens using agar well diffusion method. The AgNPs yields were modeled using a second-order factorial design. The result showed that the rate of formation of the AgNPs increased with respect to time while the optimum ratio of plant extract to the AgNO₃ solution was 1:1. The hydroxyl group was strongly involved in the bioreduction of the silver salt as indicated by the FTIR spectra. The synthesized AgNPs were crystalline in nature, with a uniformly distributed network of the web-like structure. The factorial model predicted the nanoparticles yields with minimal errors. The nanoparticles were active against all the tested pathogens and thus have great potentials as antimicrobial agents.

Keywords: antimicrobial activities, green synthesis, silver nanoparticles, Tithonia diversifolia

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Authors: M. Masłowski, M. Zaborski

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Magnetorheological elastomer composites based on micro- and nano-sized Fe3O4 magnetoactive fillers in silicone rubber are reported and studied. To improve the dispersion of applied fillers in polymer matrix, ionic liquids such as 1-ethyl-3-methylimidazolium diethylphosphate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium trifluoromethanesulfonate,1-butyl-3-methylimidazolium tetrafluoroborate, trihexyltetradecylphosphonium chloride were added during the process of composites preparation. The method of preparation process influenced the specific properties of MREs (isotropy/anisotropy), similarly to ferromagnetic particles content and theirs quantity. Micro and non-sized magnetites were active fillers improving the mechanical properties of elastomers. They also changed magnetic properties and reinforced the magnetorheological effect of composites. Application of ionic liquids as dispersing agents influenced the dispersion of magnetic fillers in the elastomer matrix. Scanning electron microscopy images used to observe magnetorheological elastomer microstructures proved that the dispersion improvement had a significant effect on the composites properties. Moreover, the particles orientation and their arrangement in the elastomer investigated by vibration sample magnetometer showed the correlation between MRE microstructure and their magnetic properties.

Keywords: magnetorheological elastomers, iron oxides, ionic liquids, dispersion

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Authors: K. R. Roopesh Bharatwaj, Avinash Maharana, Favour Tobi Aborisade, Roger Young

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Presently, there are few cases of complete automation of drones and its allied intelligence capabilities. In essence, the potential of the drone has not yet been fully utilized. This paper presents feasible methods to build an intelligent drone with smart capabilities such as self-driving, and obstacle avoidance. It does this through advanced Reinforcement Learning Techniques and performs object detection using latest advanced algorithms, which are capable of processing light weight models with fast training in real time instances. For the scope of this paper, after researching on the various algorithms and comparing them, we finally implemented the Deep-Q-Networks (DQN) algorithm in the AirSim Simulator. In future works, we plan to implement further advanced self-driving and object detection algorithms, we also plan to implement voice-based speech recognition for the entire drone operation which would provide an option of speech communication between users (People) and the drone in the time of unavoidable circumstances. Thus, making drones an interactive intelligent Robotic Voice Enabled Service Assistant. This proposed drone has a wide scope of usability and is applicable in scenarios such as Disaster management, Air Transport of essentials, Agriculture, Manufacturing, Monitoring people movements in public area, and Defense. Also discussed, is the entire drone communication based on the satellite broadband Internet technology for faster computation and seamless communication service for uninterrupted network during disasters and remote location operations. This paper will explain the feasible algorithms required to go about achieving this goal and is more of a reference paper for future researchers going down this path.

Keywords: convolution neural network, natural language processing, obstacle avoidance, satellite broadband technology, self-driving

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Authors: Sungging Pintowantoro, Yuli Setiyorini, Rochman Rochim, Agung Purniawan

Abstract:

The bacterial infections are frequent and undesired occurrences after bone fracture treatment. One approach to reduce the incidence of bone fracture infection is the additional of microbial agents into bone cement. In this study, the synthesis of bone cement from re-cycles biowaste was successfully conducted completed with anti-bacterial function. The re-cycle of biowaste using microwave assisted was done in our previous studies in order to produce some of powder (calcium carbonate, carbonated-hydroxyapatite and chitosan). The ratio of these powder combined with methylmethacrylate (MMA) as the matrix in bone cement were investigated using XRD, FTIR, SEM-EDX, hardness test and anti-bacterial test, respectively. From the XRD, FTIR and EDX were resulted the formation of carbonated-hydroxyapatite, calcium carbonate and chitosan. The morphology was revealed porous structure both C2H3K1L and C2H1K3L, respectively. The antibacterial activity was tested against Staphylococcus aureus (S. aureus) for 24 hours. The inhibition of S. aureus was clearly shown, the hollow zone was resulted in various distance 14.2mm, 7.5mm, and 7.7mm, respectively. The hardness test was depicted in various results, however, C2H1K3L can be achived 36.84HV which is closed to dry cancelous bone 35HV. In general, this study results was promising materials to use as bone cement materials.

Keywords: biomaterials, biowaste recycling, materials processing, microwave processing

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Authors: H. Mokaddem, D. Miroud, N. Azouaou, F. Si-Ahmed, Z. Sadaoui

Abstract:

The synthesis and characterization of activated carbon from local lignocellulosic precursor (Algerian alfa) was carried out for the removal of cationic dyes from aqueous solutions. The effect of the production variables such as impregnation chemical agents, impregnation ratio, activation temperature and activation time were investigated. Carbon obtained using the optimum conditions (CaCl2/ 1:1/ 500°C/2H) was characterized by various analytical techniques scanning electron microscopy (SEM), infrared spectroscopic analysis (FTIR) and zero-point-of-charge (pHpzc). Adsorption tests of methylene blue on the optimal activated carbon were conducted. The effects of contact time, amount of adsorbent, initial dye concentration and pH were studied. The adsorption equilibrium examined using Langmuir, Freundlich, Temkin and Redlich–Peterson models reveals that the Langmuir model is most appropriate to describe the adsorption process. The kinetics of MB sorption onto activated carbon follows the pseudo-second order rate expression. The examination of the thermodynamic analysis indicates that the adsorption process is spontaneous (ΔG ° < 0) and endothermic (ΔH ° > 0), the positive value of the standard entropy shows the affinity between the activated carbon and the dye. The present study showed that the produced optimal activated carbon prepared from Algerian alfa is an effective low-cost adsorbent and can be employed as alternative to commercial activated carbon for removal of MB dye from aqueous solution.

Keywords: activated carbon, adsorption, cationic dyes, Algerian alfa

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Authors: Michal Natan, Ori Gutman, Shlomo Margel, Ehud Banin

Abstract:

Biofilm formation is a serious problem in medical and industrial settings due to the increased resistance of these communities to killing compared to free-living bacteria. This has prompted the search for agents that can inhibit both bacterial growth and biofilm formation. In this study, N-halamine rechargeable nanoparticles (NPs) were synthesized by co-polymerization of the monomer methacryl amide and the cross-linker monomer N,N-methylene bisacryl amide, and were subsequently loaded with Cl+, using bleach. The chlorinated NPs exhibited remarkable stability to organic reagents. The antibacterial mechanism of the P(MAA-MBAA)-Cl NPs involved generation of reactive oxygen species (ROS) only upon exposure to organic media, but not upon incubation in water, suggesting a specific activation. Moreover, a unique interaction of the P(MAA-MBAA)-Cl NPs with Staphylococcus aureus bacteria but not with human cells was discovered, whereby these microorganisms were all specifically targeted and marked for destruction. Finally, in collaboration with Netafim Ltd. irrigation drippers containing the P(MAA-MBAA)-Cl were incubated in the field and were shown to prevent fouling on them for 5 months as opposed to the control drippers that exhibited substantial fouling. Further, the NPs offer recharging to the surface, thus providing long-lasting protection that does not exist in the products available today. Taken together, the results demonstrate the great potential of implementing the charged NPs in devices and surfaces to prevent bacterial growth.

Keywords: bacteria, biofilm, fouling, nanoparticles

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Authors: Syue-Liang Lin, C. Allen Chang

Abstract:

Luminescence imaging is an important technique used in biomedical research and clinical diagnostic applications in recent years. Concurrently, the development of NIR luminescence probes / imaging contrast agents has helped the understanding of the structural and functional properties of cells and animals. Photodynamic therapy (PDT) is used clinically to treat a wide range of medical conditions, but the therapeutic efficacy of general PDT for deeper tumor was limited by the penetration of excitation source. The tumor targeting biomedical nanomaterials UCNP@PS (upconversion nanoparticle conjugated with photosensitizer) for photodynamic therapy and near-infrared imaging of cancer will be developed in our study. Synthesis and characterization of biomedical nanomaterials were completed in this studies. The spectrum of UCNP was characterized by photoluminescence spectroscopy and the morphology was characterized by Transmission Electron Microscope (TEM). TEM and XRD analyses indicated that these nanoparticles are about 20~50 nm with hexagonal phase. NaYF₄:Ln³⁺ (Ln= Yb, Nd, Er) upconversion nanoparticles (UCNPs) with core / shell structure, synthesized by thermal decomposition method in 300°C, have the ability to emit visible light (upconversion: 540 nm, 660 nm) and near-infrared with longer wavelength (downconversion: NIR: 980 nm, 1525 nm) by absorbing 800 nm NIR laser. The information obtained from these studies would be very useful for applications of these nanomaterials for bio-luminescence imaging and photodynamic therapy of deep tumor tissue in the future.

Keywords: Near Infrared (NIR), lanthanide, core-shell structure, upconversion, theranostics

Procedia PDF Downloads 235

Authors: I. T. Adebayo, J. R. Aworemi, V. A. Ogundele, O. J. Babalola, J. O. Ajayi

Abstract:

The behavior of road users is a critical element in road safety. However, despite the proven effectiveness of the seat belt in reducing injury severity, some drivers still do not use the seat belt. The study, therefore, examined seat belt usage among drivers in Ogbomoso, Oyo State, Nigeria. Face-to-face surveys were conducted to elicit data on seat belt usage and road behaviors on 54,038 drivers plying the General-Lautech Road in Ogbomoso over a period of six months. Data collected were analyzed using both descriptive and inferential statistics. Findings revealed that seat belt usage was moderate among private car drivers in the morning (52.75 percent) and much lower in the evening (37.67 percent), while less than 30 percent of the commercial bus/taxi drivers used the seat during both periods. The paired T-test revealed a significant difference in seat belt usage by all the drivers in the morning and in the evening, as indicated with a T value of 113.977 and the level of significance p < 0.05. The study concluded that there is a significant difference in the usage of the seat belt by both private car and commercial bus/taxi drivers in Ogbomoso as most drivers made use of the seat belt, especially in the morning, to avoid being delayed when flagged down and fined for non-compliance with seat belt usage by the road traffic law enforcement agents. However, most of the drivers cited inadequate/lack of enforcement of compulsory use of seat belts by the relevant agencies and discomfort as the major reasons for not using the seat belt while driving.

Keywords: drivers, road , seat belt, traffic psychology

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Authors: Serges Djoyou Kamga, Gerard Emmanuel Kamdem Kamga

Abstract:

Any serious constitutionalism entails a system of government characterised by the separation of powers between the executive, the legislature, and the judiciary. The latter is generally in charge of upholding the rule of law and the respect for human rights which are vital for the functioning of any democracy. Therefore, for the judiciary to play its role as a watchdog, it should be independent from other branches of government. The aim of this paper is to examine the independence of the judiciary in South Africa after 20 of democracy. Defining judicial independence as the courts’ ability ‘to decide cases on the basis of established law and the merits of the case, without interference from other political or governmental agents’, the paper examines the extent to which the South African judiciary is independent after twenty years of democracy. As part of assessing the independence of the judiciary, the paper begins by looking at the situation during apartheid, then proceeds with an examination of the post-apartheid legal order. It also examines the institutional independence of the judiciary by looking into its day to day activities which revolve around its self-governance, or administrative and financial independence. In addition, the paper assesses the judges’ individual independence by examining whether judicial appointment, security of tenure, judges’ remuneration and disciplinary actions and the removal of judges from office do not contain loopholes that can hinder judicial independence. Ultimately, the chapter argues that although the South African model of judicial independence is yet to be perfect, it is a good practice that can be emulated by other African countries.

Keywords: judical independence, South Africa, democracy, separation of powers

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Authors: Rafiat Bolanle Fasasi-Hammed

Abstract:

Cassava is an important food crop in rural households of Nigeria. It has a high potential for product diversification, because it can be processed into various products forms for human consumption and can be made into chips for farm animals, and also starch and starch derivatives. However, cassava roots are highly perishable and contain potentially toxic cyanogenic glycosides which necessitate its processing. Therefore, this study was carried out to assess information needs of cassava processors on food safety practices in Oyo State, Nigeria. Simple random sampling technique was used in the selection of 110 respondents for this study. Descriptive statistics and chi-square were used to analyze the data collected. Results of this study showed that the mean age of the respondents was 39.4 years, majority (78.7%) of the respondents was married, 51.9% had secondary education; 45.8% of the respondents have spent more than 12 years in cassava processing. The mean income realized was ₦26,347.50/month from cassava processing. Information on cassava processing got to the respondents through friends, family and relations (73.6%) and fellow cassava processors (58.6%). Serious constraints identified were ineffective extension agents (93.9%), food safety regulatory agencies (88.1%) and inadequate processing and storage facilities (67.8%). Chi-square results showed that significant relationship existed between socio-economic characteristics of the respondents (χ2 = 29.80, df = 2,), knowledge level (χ2 = 9.26, df = 4), constraints (χ2 = 13.11, df = 2) and information needs at p < 0.05 level of significance. The study recommends that there should be regular training on improved cassava processing methods for the cassava processors in the study area.

Keywords: information, needs, cassava, Oyo State, processing

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Authors: Gabriele Iannotta

Abstract:

This paper investigates credit cycles by means of an experiment based on a Kiyotaki & Moore (1997) model with heterogeneous expectations. The aim is to examine how a credit squeeze caused by high lender-level risk perceptions affects the real prices of a collateralised asset, with a special focus on the macroeconomic implications of rising price volatility in terms of total welfare and the number of bankruptcies that occur. To do that, a learning-to-forecast experiment (LtFE) has been run where participants are asked to predict the future price of land and then rewarded based on the accuracy of their forecasts. The setting includes one lender and five borrowers in each of the twelve sessions split between six control groups (G1) and six treatment groups (G2). The only difference is that while in G1 the lender always satisfies borrowers’ loan demand (bankruptcies permitting), in G2 he/she closes the entire credit market in case three or more bankruptcies occur in the previous round. Experimental results show that negative risk-driven supply shocks amplify the volatility of collateral prices. This uncertainty worsens the agents’ ability to predict the future value of land and, as a consequence, the number of defaults increases and the total welfare deteriorates.

Keywords: Behavioural Macroeconomics, Credit Cycle, Experimental Economics, Heterogeneous Expectations, Learning-to-Forecast Experiment

Procedia PDF Downloads 125