Search results for: toxicity mechanism
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4006

Search results for: toxicity mechanism

3916 Toxicological Interactions of Silver Nanoparticles and Non-Essential Metals in Human Hepatocarcinoma Cell Line

Authors: Renata Rank Miranda, Arandi Ginane Bezerra, Ciro Alberto Oliveira Ribeiro, Marco AntôNio Ferreira Randi, Carmen Lúcia Voigt, Lilian Skytte, Kaare Lund Rasmussen, Francisco Filipak Neto, Frank Kjeldsen

Abstract:

Synergetic and antagonistic effects of drugs are well-known concerns in pharmacological assessments of dose and toxicity. Similar approach should be used in assessing cellular uptake and cytotoxicity of nanoparticles. Since nanoparticles are released into the aquatic environment they may interact with existing xenobiotics. Here we used biochemical assays and quantitative proteomics to assess the cytotoxicity of silver nanoparticles (AgNP) when human hepatoma HepG2 cells were co-exposed to 2 nm AgNP together with either Cd2+ or Hg2+ ions. Time-course experiments (2h, 4h, and 24h) were conducted to assess the first response to the exposure studies. The general trend was that a synergetic toxicological response was observed in cells exposed to both AgNP and Cd2+ or Hg2+, with AgNP and Cd2+ being more toxic. This was observed by a significant increase in the ROS and superoxide level of >35% in the case of AgNP+Cd2+ compared to the sum of responses of AgNP and Cd2+, individually. Metabolic activity and viability also dropped more for AgNP+Cd2+ (>10%) than for AgNP and Cd2+ combined. We used inductively coupled plasma mass spectrometry to investigate if AgNP facilitates larger influx of toxic metal ions into HepG2 cells. Only Hg2+ ions was found to be more efficiently engulfed as the concentration of Hg2+ was found 2.8 times larger compared to exposure experiments with only Hg2+. This effect was not observed for Cd2+. We now continue with deep proteomics studies to obtain wider details on the mechanism of the toxicity related to AgNP, Cd2+, and AgNP+Cd2+, respectively.

Keywords: nanotoxicology, silver nanoparticles, proteomics, human cell line

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3915 A Computational Study Concerning the Biological Effects of the Most Commonly Used Phthalates

Authors: Dana Craciun, Daniela Dascalu, Adriana Isvoran

Abstract:

Phthalates are a class of plastic additives that are used to enhance the physical properties of plastics and as solvents in paintings and some of them proved to be of particular concern for the human health. There are insufficient data concerning the health risks of phthalates and further research on evaluating their effects in humans is needed. As humans are not volunteers for such experiments, computational analysis may be used to predict the biological effects of phthalates in humans. Within this study we have used some computational approaches (SwissADME, admetSAR, FAFDrugs) for predicting the absorption, distribution, metabolization, excretion and toxicity (ADME-Tox) profiles and pharmacokinetics for the most common used phthalates. These computational tools are based on quantitative structure-activity relationship modeling approach. The predictions are further compared to the known effects of each considered phthalate in humans and correlations between computational results and experimental data are discussed. Our data revealed that phthalates are a class of compounds reflecting high toxicity both when ingested and when inhaled, but by inhalation their toxicity is even greater. The predicted harmful effects of phthalates are: toxicity and irritations of the respiratory and gastrointestinal tracts, dyspnea, skin and eye irritations and disruption of the functions of liver and of the reproductive system. Many of investigated phthalates are predicted to be able to inhibit some of the cytochromes involved in the metabolism of numerous drugs and consequently to affect the efficiency of administrated treatments for many diseases and to intensify the adverse drugs reactions. The obtained predictions are in good agreement with clinical data concerning the observed effects of some phthalates in cases of acute exposures. Our study emphasizes the possible health effects of numerous phthalates and underlines the applicability of computational methods for predicting the biological effects of xenobiotics.

Keywords: phthalates, ADME-Tox, pharmacokinetics, biological effects

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3914 Optimality of Shapley Value Mechanism under Sybil Strategies

Authors: Bruno Mazorra Roig

Abstract:

In the realm of cost-sharing mechanisms, the vulnerability to Sybil strategies, where agents can create fake identities to manipulate outcomes, has not yet been studied. In this paper, we delve into the intricacies of different cost-sharing mechanisms proposed in the literature, highlighting its non-Sybil-resistance nature. Furthermore, we prove that under mild conditions, a Sybil-proof cost-sharing mechanism for public excludable goods is at least (n/2 + 1)−approximate. This finding reveals an exponential increase in the worst-case social cost in environments where agents are restricted from using Sybil strategies. We introduce the concept of Sybil Welfare Invariant mechanisms, where a mechanism maintains its worst-case welfare under Sybil strategies for every set of prior beliefs with full support even when the mechanism is not Sybil-proof. Finally, we prove that the Shapley value mechanism for public excludable goods holds this property and so deduce that the worst-case social cost of this mechanism is the nth harmonic number Hn under the equilibrium of the game with Sybil strategies, matching the worst-case social cost bound for cost-sharing mechanisms. This finding carries important implications for decentralized autonomous organizations (DAOs), indicating that they are capable of funding public excludable goods efficiently, even when the total number of agents is unknown.

Keywords: game theory, mechanism design, cost sharing, false-name proofness

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3913 Design and Optimization for a Compliant Gripper with Force Regulation Mechanism

Authors: Nhat Linh Ho, Thanh-Phong Dao, Shyh-Chour Huang, Hieu Giang Le

Abstract:

This paper presents a design and optimization for a compliant gripper. The gripper is constructed based on the concept of compliant mechanism with flexure hinge. A passive force regulation mechanism is presented to control the grasping force a micro-sized object instead of using a sensor force. The force regulation mechanism is designed using the planar springs. The gripper is expected to obtain a large range of displacement to handle various sized objects. First of all, the statics and dynamics of the gripper are investigated by using the finite element analysis in ANSYS software. And then, the design parameters of the gripper are optimized via Taguchi method. An orthogonal array L9 is used to establish an experimental matrix. Subsequently, the signal to noise ratio is analyzed to find the optimal solution. Finally, the response surface methodology is employed to model the relationship between the design parameters and the output displacement of the gripper. The design of experiment method is then used to analyze the sensitivity so as to determine the effect of each parameter on the displacement. The results showed that the compliant gripper can move with a large displacement of 213.51 mm and the force regulation mechanism is expected to be used for high precision positioning systems.

Keywords: flexure hinge, compliant mechanism, compliant gripper, force regulation mechanism, Taguchi method, response surface methodology, design of experiment

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3912 Impact of a Biopesticide Formulated an Entomopathogenic Fungus Metarhizium Anisopliae et Abstracts of Two Different Plants Sage (Salvia officinalis) and American Paper (Schinus molle) on Aphis Fabae (Homoptera - Aphididae)

Authors: Hicham Abidallah

Abstract:

In this work we realized a formulation of an entomopathogenic fungus Metarhizium anisopliae with a dose of 1,7 x 105 spores/ml, and aqueous abstracts of two different plants sage (Salvia officinalis) and American paper (Schinus molle) with they’re full dose and half dose, on a black bean aphid populations (Aphis fabae) on a bean crop planted in pots at semi-controlled conditions. Five formulations were achieved (Met, Fd, F1/2d, Sd et S1/2d) and tested on six blocks each one contained six pots. This study revealed that four (04) formulations exercised an influence over black bean aphid (Met, Fd, F1/2d, Sd), of which Metarhizium marked the most elevated and aggressive toxicity with an efficiency of 99,24%, however, sage formulation with the half dose (S1/2d ) marked a weak toxicity with an efficiency of 18%. Test of Metarhizium anisopliae on bees didn’t show toxicity, and no mortality has been marked, and no trace of green Muscardine observed.

Keywords: Metarhizium anisopliae, salvia officinalis, Schinus molle, Aphis fabae, efficiency degree

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3911 Nanoparticles on Biological Biomarquers Models: Paramecium Tetraurelia and Helix aspersa

Authors: H. Djebar, L. Khene, M. Boucenna, M. R. Djebar, M. N. Khebbeb, M. Djekoun

Abstract:

Currently in toxicology, use of alternative models permits to understand the mechanisms of toxicity at different levels of cells. Objectives of our research concern the determination of NPs ZnO, TiO2, AlO2, and FeO2 effect on ciliate protist freshwater Paramecium sp and Helix aspersa. The result obtained show that NPs increased antioxidative enzyme activity like catalase, glutathione –S-transferase and level GSH. Also, cells treated with high concentrations of NPs showed a high level of MDA. In conclusion, observations from growth and enzymatic parameters suggest on one hand that treatment with NPs provokes an oxidative stress and on the other that snale and paramecium are excellent alternatives models for ecotoxicological studies.

Keywords: NPs, GST, catalase, GSH, MDA, toxicity, snale and paramecium

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3910 Subacute Toxicity Study of Total Alkaloids of Seeds of Peganum harmala in Female Rat

Authors: Mahdeb Nadia, Ghadjati Nadhra, Bettihi Sara, Daamouche Z. El Youm, Bouzidi Abdelouahab

Abstract:

The effects of subacute administration of total alkaloids of seeds Peganum harmala were studied in female Albino-Wistar rats. After intraperitoneal administration of dose 50 mg/kg for 10 days and 40 mg/kg for 7 days of total alkaloids to the seeds of Peganum harmala (animal treatment lasted 17 days), there were remarkable changes in general appearance and deaths occurred in experimental group. After 17 days a significant reduction was observed in the surviving animals treated with total alkaloid seeds.The Red Blood Cells (RBC), Hematocrit (HCT), Hemoglobin (HGB) and White blood cells (WBCs), show significant reduction in the treated groups. There were no statistical differences in Glutamic-Oxaloacetic Transaminase (GOT), Glutamic-pyruvic Transaminase (GPT) and Alkaline Phosphatase (ALP), total protein, glucose and creatinine observed between groups. However the urea was significantly higher in the treated female rats than the control group. Histological examination of liver showed no histopathological changes. Alkaloids of Peganum harmala showed significant toxicity in female rats.

Keywords: Peganum harmala, rat, liver, kidney, alkaloids, toxicity

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3909 In Vivo Assessment of Biogenically Synthesized Silver Nanoparticles

Authors: Muhammad Shahzad Tufail, Iram Liaqat

Abstract:

Silver nanoparticles (AgNPs) have wider biomedical applications due to their intensive antimicrobial activities. However, toxicity and side effects of nanomaterials like AgNPs is a subject of great controversy towards the further studies in this direction. In this study, biogenically synthesized AgNPs, previously characterized via ultraviolet (UV) visible spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR), were subjected to toxicity evaluation using mice model. Albino male mice (BALB/c) were administered with 50 mgkg-1, 100 mgkg-1 and 150 mgkg-1 of AgNPs, respectively, except for control for 30 days. Log-probit regression analysis was used to measure the dosage response to determine the median lethal dose (LD50). Exposure to AgNPs caused significant changes in the levels of serum AST (P ˂ 0.05) at the 100mgkg-1 and 150mgkg-1 of AgNPs exposure, while ALT and serum creatinine (P ˃ 0.05) levels remained normal. Histopathology of male albino mice liver and kidney was studied after 30 days experimental period. Results revealed that mice exposed to heavy dose (150 mgkg-1) of AgNPs showed cell distortion, necrosis and detachment of hepatocytes in the liver. Regarding kidney, at lower concentration, normal renal structure with normal glomeruli was observed. However, at higher concentration (150 mgkg-1), kidneys showed smooth surface and dark red colour with proliferation of podocytes. It can be concluded from present study that biologically synthesized AgNPs are small to be eliminated easily by kidney and therefore the liver and kidney did not show toxicity at low concentrations.

Keywords: silver nanoparticles, pseudomonas aeruginosa, male albino mice, toxicity assessment

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3908 Design and Analysis of Flexible Slider Crank Mechanism

Authors: Thanh-Phong Dao, Shyh-Chour Huang

Abstract:

This study presents the optimal design and formulation of a kinematic model of a flexible slider crank mechanism. The objective of the proposed innovative design is to take extra advantage of the compliant mechanism and maximize the fatigue life by applying the Taguchi method. A formulated kinematic model is developed using a Pseudo-Rigid-Body Model (PRBM). By means of mathematic models, the kinematic behaviors of the flexible slider crank mechanism are captured using MATLAB software. Finite Element Analysis (FEA) is used to show the stress distribution. The results show that the optimal shape of the flexible hinge includes a force of 8.5N, a width of 9mm and a thickness of 1.1mm. Analysis of variance shows that the thickness of the proposed hinge is the most significant parameter, with an F test of 15.5. Finally, a prototype is manufactured to prepare for testing the kinematic and dynamic behaviors.

Keywords: kinematic behavior, fatigue life, pseudo-rigid-body model, flexible slider crank mechanism

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3907 Neuroprotective Effect of Germinated Dolichos lablab on 6-Hydroxy Dopamine (6-OHDA) Induced Toxicity in SH-SY5Y Neuroblastoma Cell

Authors: Taek Hwan Lee, Moon Ho Do, Lalita Subedi, Young Un Park, Sun Yeou Kim

Abstract:

Natural and artificial toxic substances namely neurotoxins induce the bitter effect in the nervous system termed as neurotoxicity. It can modulate the normal functioning of the nervous system either hyperactivate it or damage homeostasis of neuronal system. Neurotoxins induced toxicity ultimately kills the neuron. The present study investigated the neuroprotective effects of germinated Dolichos lablab on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity using SH-SY5Y neuroblastoma cells. Germination is a process of plant growth from a seed. Sprouting of a seedling from a seed induced many molecular changes in the seed in order to prepare it for further growth. Because of these molecular and chemical changes, the neuroprotective effect of Dolichos lablab is higher in the germinated form than in the normal condition. SH-SY5Y cells were treated with Dolichos lablab extract (50, 100 g/ml) followed by 6-OHDA (25M) induced toxicity. Cell Viability was measured to check the cell survival against 6-OHDA induced toxicity using MTT assay. Dolichos lablab showed a neuroprotective effect against 6-OHDA induced neuronal cell death in neuroblastoma cell at a higher concentration of 100g/ml however the effect is much better even at the lower concentration after germination 50g/ml. Cell survival was increased dramatically after 15 h of germination and increased with time of germination in concentration dependent manner. Trigonelline as a representative compound was validated in germinated Dolichos lablab by HPLC analysis that might enhance the neuroprotective effect of Dolichos lablab. This result suggests that Dolichos lablab possess neuroprotective effect in neuroblastoma cells against 6-OHDA however its activity was more potent in the germinated form.

Keywords: dolichos lablab, germination, neuroprotection, trigonelline

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3906 Effect of Polarized Light Therapy on Oral Mucositis in Cancer Patients Receiving Chemotherapy

Authors: Zakaria Mowafy Emam Mowafy, Hamed Abd Allah Hamed, Marwa Mahmoud Abd-Elmotalb, Andrew Anis Fakhray Mosaad

Abstract:

The purpose of this paper is to determine the efficacy of polarized light therapy for chemotherapy-treated cancer patients who have oral mucositis. Methods of evaluation are the measurement of the WHO oral mucositis scale and the common toxicity criteria scale. Methods: Thirty cancer patients receiving chemotherapy (males and females) who had oral mucositis and ulceration pain, and their ages ranged from 30 to 55 years, were divided into two groups. Group (A), composed of 15 patients, received the Bioptron light therapy (BLT) in addition to the routine medical care of oral mucositis. Group (B) received only the routine medical care of oral mucositis; the duration of the BLT application was 10 minutes applied daily for 30 days. Results and conclusion: Results showed that the application of the BLT had valuable healing effects on oral mucositis in cancer patients receiving chemotherapy, as evidenced by the high decreases of the WHO oral mucositis scale and the common toxicity criteria scale.

Keywords: Bioptron light therapy, oral mucositis, WHO oral mucositis scale, common toxicity criteria scale

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3905 Chemical Characterization, Crystallography and Acute Toxicity Evaluation of Two Boronic-Carbohydrate Adducts

Authors: Héctor González Espinosa, Ricardo Ivan Cordova Chávez, Alejandra Contreras Ramos, Itzia Irene Padilla Martínez, José Guadalupe Trujillo Ferrara, Marvin Antonio Soriano Ursúa

Abstract:

Boronic acids are able to create diester bonds with carbohydrates because of their hydroxyl groups; in nature, there are some organoborates with these characteristics, such as the calcium fructoborate, formed by the union of two fructose molecules and a boron atom, synthesized by plants. In addition, it has been observed that, in animal cells only the compounds with cis-diol functional groups are capable of linking to boric or boronic acids. The formation of these organoboron compounds could impair the physical and chemical properties of the precursors, even their acute toxicity. In this project, two carbohydrate-derived boron-containing compounds from D-fructose and D-arabinose and phenylboronic acid are analyzed by different spectroscopy techniques such as Raman, Infrared with Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR) and X-ray diffraction crystallography to describe their chemical characteristics. Also, an acute toxicity test was performed to determine their LD50 using the Lorke’s method. It was confirmed by multiple spectra the formation of the adducts by the generation of the diester bonds with a β-D-pyranose of fructose and arabinose. The most prominent findings were the presence of signals corresponding to the formation of new bonds, like the stretching of B-O bonds, or the absence of signals of functional groups like the hydroxyls presented in the reagents used for the synthesis of the adducts. The NMR spectra yielded information about the stereoselectivity in the synthesis reaction, observed by the interaction of the protons and their vicinal atoms in the anomeric and second position carbons; but also, the absence of a racemic mix by the finding of just one signal in the range for the anomeric carbon in the 13C NMR spectra of both adducts. The acute toxicity tests by the Lorke’s method showed that the LD50 value for both compounds is 1265 mg/kg. Those results let us to propose these adducts as highly safe agents for further biological evaluation with medical purposes.

Keywords: acute toxicity, adduct, boron, carbohydrate, diester bond

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3904 Functionalization of Carboxylated Single-Walled Carbon Nanotubes with 2-En 4-Hydroxy Cyclo 1-Octanon and Toxicity Investigation

Authors: D. ChobfroushKhoei, S. K. Heidari , Sh. Dariadel

Abstract:

Carbon nanotubes were used in medical sciences especially in drug delivery system and cancer therapy. In this study, we functionalized carboxylated single-wall carbon nanotubes (SWNT-COOH) with 2-en 4-hydroxy cyclo 1-octanon. Synthesized sample was characterized by FT-IR, Raman spectroscopy, SEM, TGA and cellular investigations. The results showed well formation of SWNT-Ester. Cell viability assay results and microscopic observations demonstrated that cancerous cells were killed in the sample. The synthesized sample can be used as a toxic material for cancer therapy.

Keywords: MWNT-COOH, functionalization, phenylisocyanate, phenylisothiocyanate, 1, 4-phenylendiamine, toxicity investigation

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3903 Repeated Dose 28-Day Oral Toxicity Study Offungicides: Propinèbe, Propiconazole, And Their Mixture in Wistar Rats

Authors: Aiche Mohamed Amine, Mallem Leila, Yahia El Khansa, Boulakoud Mohamed Salah

Abstract:

Until recently, toxicological studies focused on the effects of individual chemicals. However, humans and wildlife are exposed to a complex milieu of chemicals from different sources including food and water, personal care products and the environment. The aim of this study is to detect the toxicity of two fungicides and their mixtures in the fertility and oxidative damge induced in the rat. The male of rats (28) were used, they were divided in four groups (7 rats of each group) and one group was used as control. Rats were dosed orally with Propiconazole 60mg/Kg/day, Propinebe 100mg/Kg/day and their mixture 30mg Propiconazole/kg/day + 50mg Propineb/kg/day for 4 weeks. Animals were observed for clinical toxicity. At the end of treatment period, animals of all groups were scarified, blood was collected for hematological and biochemical’s analysis and desired organs were removed and weighted. The results indicated that the fungicide and their mixture were toxic in the treated animals. The semen study showed a decrease in the count and mobility of spermatozoa in all treated group, it was also a decrease in the weight of the testis and epidydimis in the treated group as compared with control. Reduced glutathione (GSH), Glutathione peroxidase (GPx) level was decreased in all treated groups.

Keywords: fungicides, mixtures, fertility, oxidative stress

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3902 Effects of Manufacture and Assembly Errors on the Output Error of Globoidal Cam Mechanisms

Authors: Shuting Ji, Yueming Zhang, Jing Zhao

Abstract:

The output error of the globoidal cam mechanism can be considered as a relevant indicator of mechanism performance, because it determines kinematic and dynamical behavior of mechanical transmission. Based on the differential geometry and the rigid body transformations, the mathematical model of surface geometry of the globoidal cam is established. Then we present the analytical expression of the output error (including the transmission error and the displacement error along the output axis) by considering different manufacture and assembly errors. The effects of the center distance error, the perpendicular error between input and output axes and the rotational angle error of the globoidal cam on the output error are systematically analyzed. A globoidal cam mechanism which is widely used in automatic tool changer of CNC machines is applied for illustration. Our results show that the perpendicular error and the rotational angle error have little effects on the transmission error but have great effects on the displacement error along the output axis. This study plays an important role in the design, manufacture and assembly of the globoidal cam mechanism.

Keywords: globoidal cam mechanism, manufacture error, transmission error, automatic tool changer

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3901 Development of a Harvest Mechanism for the Kahramanmaraş Chili Pepper

Authors: O. E. Akay, E. Güzel, M. T. Özcan

Abstract:

The pepper has quite a rich variety. The development of a single harvesting machine for all kinds of peppers is a difficult research topic. By development of harvesting mechanisms, we could be able to facilitate the pepper harvesting problems. In this study, an experimental harvesting machine was designed for chili pepper. Four-bar mechanism was used for the design of the prototype harvesting machine. At the result of harvest trials, 80% of peppers were harvested and 8% foreign materials were collected. These results have provided some tips on how to apply to large-scale pepper Four-bar mechanism of the harvest machine.

Keywords: kinematic simulation, four bar linkage, harvest mechanization, pepper harvest

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3900 Mechanism of Changing a Product Concept

Authors: Kiyohiro Yamazaki

Abstract:

The purpose of this paper is to examine the hypothesis explaining the mechanism in the case, where the product is deleted or reduced the fundamental function of the product through the product concept changes in the digital camera industry. This paper points out not owning the fundamental technology might cause the change of the product concept. Casio could create new competitive factor so that this paper discusses a possibility of the mechanism of changing the product concept.

Keywords: firm without fundamental technology, product development, product concept, digital camera industry, Casio

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3899 NanoCelle®: A Nano Delivery Platform to Enhance Medicine

Authors: Sean Hall

Abstract:

Nanosystems for drug delivery are not new; as medicines evolve, so too does the desire to deliver a more targeted, patient-compliant medicine. Though, historically the widespread use of nanosystems for drug delivery has been fouled by non-replicability, scalability, toxicity issues, and economics. Examples include steps of manufacture and thus cost to manufacture, toxicity for nanoparticle scaffolding, autoimmune response, and considerable technical expertise for small non-commercial yields. This, unfortunately, demonstrates the not-so-obvious chasm between science and drug formulation for regulatory approval. Regardless there is a general and global desire to improve the delivery of medicines, reduce potential side effect profiles, promote increased patient compliance, and increase and/or speed public access to medicine availability. In this paper, the author will discuss NanoCelle®, a nano-delivery platform that specifically addresses degradation and solubility issues that expands from fundamental micellar preparations. NanoCelle® has been deployed in several Australian listed medicines and is in use of several drug candidates across small molecules, with research endeavors now extending into large molecules. The author will discuss several research initiatives as they relate to NanoCelle® to demonstrate similarities seen in various drug substances; these examples will include both in vitro and in vivo work.

Keywords: NanoCelle®, micellar, degradation, solubility, toxicity

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3898 Explicable Enzymatic Mechanism of H-Ido to Oxidise Tryptophan by Employing Various Substrates

Authors: Ali Bahri Lubis

Abstract:

The study of dioxygenase enzymatic mechanism on tryptophan oxidation has been a wide interest since the reaction is rate-limiting step of kynurenine pathway. In this research, observation of tryptophan oxidation through h-IDO enzyme along with synthesis of enzyme products was conducted in order to comprehend how the enzyme works on distinct substrates. UV-vis spectrophotometry, LC-MS, H-NMR and HSQC measurement were carried out to characterise enzyme product. It is found that while tryptophan was oxidised to form Nformylkynurenine (NFK) as a major product and hydroxypyrroloindole amine carboxylic acid (HPIC) in cis and trans confirmed in HSQC, N-methyl tryptophan substrate was converted to NFK and trans HPIC only. Other intriguing results showed that 5-hydroxy- tryptophan and Stryptophan was degraded to become NFK and epoxide cyclic respectively. The formation of NFK was considered through dioxygenation pathway, however HPIC was formed via monooxygenation. The epoxide cyclic—considered as intermediate compound in the mechanism— from S-tryptophan was not able to cleave the epoxide ring since bond energy of epoxide was probably much stronger. This validates the enzymatic mechanism where the intermediate compound in the enzymatic mechanism is epoxide cyclic.

Keywords: tryptophan oxidation, heme-dioxygenases, N-formylkynurenine, hydroxypyrrroloindoleamine, monooxidation

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3897 A Workable Mechanism to Support Students Who Are at Risk

Authors: Mohamed Chabi

Abstract:

The project of helping students at risk started at the Math department in the new foundation program at Qatar University in the fall 2012 semester. The purpose was to find ways to help students who were struggling with their math courses Elementary algebra or Precalculus course due to many factors. Department had formed the Committee “students at Risk” at the start of 12-13 to assist struggling students in our math courses to get their studies on track. A mechanism was developed to support students who are at risk using a developed E-Monitoring system. E-Monitoring system was developed to manage automatically all transactions relevant to the students’ attendance, Students ‘‘warning Students’’ grading, etc. E-Monitoring System produce various statistics such as, Overall course statistics, Performance, Students at Risk… to help department to develop a higher quality of education in the Foundation Program at Math department. The mechanism was studies and evaluated. Whatever the cause, the sooner we identify students who are not performing well academically, the sooner we can provide, or direct them to the resources that are available to them. In this paper, we outline the mechanism and its effect on students’ performance. The collected data from various exams shows that students had benefited from the mechanism.

Keywords: students at risk, e-monitoring system, warning students, performance

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3896 The Protective Effect of Grape Seed Oil with Use of Ciprofloxacin Induced Germ Cell Toxicity in Male Albino Mice

Authors: Galawezh Obaid Othman

Abstract:

The present investigation was undertaken to evaluate the germ cell toxicity induced by ciprofloxacin antibiotic and the Protective effect of grape seed oil, Ciproflaxin uses include treatment of genitor-urinary and some reproductive tract bacterial infections. One of the most attractive approaches to disease prevention involves the use of natural antioxidants to protect tissue against toxic injury, the possible protective effect of grape seed oil, against ciprofloxacin induced reproductive toxicity on mouse .the animals were randomly divided into four groups consisting of five mice. Group (1) was orally given distilled water (solvent of the used drugs) and kept as a control. Group (2) was administered 6ml/kg. b.w of grape seed oil orally 15 days .Group (3) was administered 206mg/kg. b.w of ciprofloxacin orally for 15 days.. Last group was treated orally with Grape seed oil (6mg/kg b.w. /day) prior to an orally administered ciprofloxacin (CPX) at a dose of 206 mg⁄kg. b.w. by three hours for fifteen days. Ciproflaxin have ability to induce various types of sperm abnormalities such as (Sperm without head, sperm without tail, defective head spearm,swollen head sperm ), The results explored that Grape seed oil possesses statistically significant (p<0.05) protective potential against Ciproflaxin by decreasing sperm abnormalities frequency in mouse.

Keywords: antimutagen, ciprofloxacin, grape seed oil, germ cell

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3895 Oral Toxicity of Low Doses of Fungicides, Propinebe, Propiconazole and Their Mixtures in the Male Rat

Authors: Mallem Leila, Aiche Mohamed Amine, Boulakoud Mohamed Salah

Abstract:

A number of chemical compounds are being used to protect agricultural crops from diseases. Residues of these chemicals lead to environmental pollution and pose some threat to non target organisms, human and animal. The aim of this study is to detect the toxicity of these fungicides and their mixtures in the fertility and biochemical’s parameters in the rat. The male of rats (28) were used, they were divided in four groups (7 rats of each group) and one group was used as control. Rats were dosed orally with propiconazole (60 mg/kg body weight/day), propinebe (100 mg/Kg body weight/day) and their mixture (50:50) for 4 weeks. Animals were observed for clinical toxicity. At the end of treatment period, animals of all groups were scarified and samples of different organs were fixed in the formol 10% for histopathological study, and blood was collected for hematological and biochemical’s analysis. The results indicated that the fungicide and their mixture of fungicides were toxic in the treated animals. The semen study showed a decrease in the count, mobility and speed of spermatozoa in all treated group especially those dosed with the mixture and Propiconazole, it was also a decrease in the weight of the testis and epidydimis in the treated group as compared with control. Remarquable histological changes were observed in the testis and epidydimis and liver in the group treated with mixture.

Keywords: fungicides, mixture, fertility, hematological, biochemical's parameters

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3894 Corrosion Risk Assessment/Risk Based Inspection (RBI)

Authors: Lutfi Abosrra, Alseddeq Alabaoub, Nuri Elhaloudi

Abstract:

Corrosion processes in the Oil & Gas industry can lead to failures that are usually costly to repair, costly in terms of loss of contaminated product, in terms of environmental damage and possibly costly in terms of human safety. This article describes the results of the corrosion review and criticality assessment done at Mellitah Gas (SRU unit) for pressure equipment and piping system. The information gathered through the review was intended for developing a qualitative RBI study. The corrosion criticality assessment has been carried out by applying company procedures and industrial recommended practices such as API 571, API 580/581, ASME PCC 3, which provides a guideline for establishing corrosion integrity assessment. The corrosion review is intimately related to the probability of failure (POF). During the corrosion study, the process units are reviewed by following the applicable process flow diagrams (PFDs) in the presence of Mellitah’s personnel from process engineering, inspection, and corrosion/materials and reliability engineers. The expected corrosion damage mechanism (internal and external) was identified, and the corrosion rate was estimated for every piece of equipment and corrosion loop in the process units. A combination of both Consequence and Likelihood of failure was used for determining the corrosion risk. A qualitative consequence of failure (COF) for each individual item was assigned based on the characteristics of the fluid as per its flammability, toxicity, and pollution into three levels (High, Medium, and Low). A qualitative probability of failure (POF)was applied to evaluate the internal and external degradation mechanism, a high-level point-based (0 to 10) for the purpose of risk prioritizing in the range of Low, Medium, and High.

Keywords: corrosion, criticality assessment, RBI, POF, COF

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3893 Effect of Pristine Graphene on Developmental Toxicity in Zebrafish (Danio rerio) Embryos: Cardiovascular Defects, Apoptosis, and Globin Expression Analysis

Authors: Manjunatha Bangeppagari, Lee Sang Joon

Abstract:

Recently, graphene-related nanomaterials are receiving fast-increasing attention with augmented applications in various fields. Especially, graphene-related materials have been widely applied to the biomedical field in the past years. In the present study, we evaluated the adverse effects of pristine graphene (pG) in zebrafish (Danio rerio) embryos in various aspects, such as mortality rate, heart rate, hatching rate, cardiotoxicity, cardiovascular defect, cardiac looping, apoptosis, and globin expression. For various trace concentrations of pG (1, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 μg/L), early life-stage parameters were observed at 24, 48, 72, and 96 hpf. As a result, pG induces significant developmental defects including yolk sac edema, pericardial edema, embryonic mortality, delayed hatching, heartbeat, several morphological defects, pericardial toxicity, and bradycardia. Moreover, the exposure to pG was found to be a potential risk factor to the cardiovascular system of zebrafish embryos. However, further study on their properties which vary according to production methods and surface functionalization is essentially required. In addition, the possible risks of pG flakes to aquatic animals, and public health should be evaluated before releasing them to the surrounding environment.

Keywords: apoptosis, cardiovascular toxicity, globin expression, pristine graphene, zebrafish embryos

Procedia PDF Downloads 134
3892 Structured Access Control Mechanism for Mesh-based P2P Live Streaming Systems

Authors: Chuan-Ching Sue, Kai-Chun Chuang

Abstract:

Peer-to-Peer (P2P) live streaming systems still suffer a challenge when thousands of new peers want to join into the system in a short time, called flash crowd, and most of new peers suffer long start-up delay. Recent studies have proposed a slot-based user access control mechanism, which periodically determines a certain number of new peers to enter the system, and a user batch join mechanism, which divides new peers into several tree structures with fixed tree size. However, the slot-based user access control mechanism is difficult for accurately determining the optimal time slot length, and the user batch join mechanism is hard for determining the optimal tree size. In this paper, we propose a structured access control (SAC) mechanism, which constructs new peers to a multi-layer mesh structure. The SAC mechanism constructs new peer connections layer by layer to replace periodical access control, and determines the number of peers in each layer according to the system’s remaining upload bandwidth and average video rate. Furthermore, we propose an analytical model to represent the behavior of the system growth if the system can utilize the upload bandwidth efficiently. The analytical result has shown the similar trend in system growth as the SAC mechanism. Additionally, the extensive simulation is conducted to show the SAC mechanism outperforms two previously proposed methods in terms of system growth and start-up delay.

Keywords: peer-to-peer, live video streaming system, flash crowd, start-up delay, access control

Procedia PDF Downloads 318
3891 A Comparison of Sulfur Mustard Cytotoxic Effects on the Two Human Lung Origin Cell Lines

Authors: P. Jost, L. Muckova, M. Matula, J. Pejchal, D. Jun, R. Stetina

Abstract:

Sulfur mustard (bis(2-chlorethyl) sulfide) is highly toxic, chemical warfare agent that has been used in the past in several armed conflicts. Except for the skin, respiratory tract is one of the important routes of exposure. The elucidation and understanding of the mechanism of toxicity of SM have been effort intensive research. The multiple targets character of SM caused cellular damage resulted in activation of many different mechanisms which contribute to cellular response and participate in the final cytopathology effect. In our present work, we compared time-dependent changes in sulfur mustard exposed adult human lung fibroblasts NHLF and lung epithelial alveolar cell line A-549. Cell viability (MTT assay, Calcein-AM assay, and xCELLigence - real-time cell analysis), apoptosis (flow cytometry), mitochondrial membrane potential (Δψm, flow cytometry), reactive oxygen species induction (DC and cell cycle distribution (flow cytometry) were studied. We observed significantly decreased mitochondrial membrane potential and subsequent induction of apoptosis correlating with decreased cellular viability in the sulfur mustard exposed cells. In low concentrations, sulfur mustard-induced S-phase cell cycle arrest, on the other hand, high concentrations, cell cycle phase distribution of sulfur mustard exposed cells resembled cell cycle phase distribution of control group, which implies nonspecific cell cycle inhibition. Epithelial cells A-549 was found as more sensible to sulfur mustard toxicity. Acknowledgements: This work was supported by a long-term organization development plan Medical Aspects of Weapons of Mass Destruction of the Faculty of Military Health Sciences, University of Defence.

Keywords: apoptosis, cell cycle, cytotoxicity, sulfur mustard

Procedia PDF Downloads 194
3890 Role of Microbial Pesticides in Pest Control and Their Advantages and Disadvantages in Nature

Authors: Fatimah M. Alshehrei

Abstract:

For many years, synthetic pesticides have been used to kill pests; due to their toxicity and pollution, they are now a risk to human and environmental health. Lately, biopesticides have emerged as possible substitutes for petrochemical pesticides. The sources of biopesticides are widely accessible, easily biodegradable, have a variety of modes of action, are less expensive, and have little toxicity toward humans and other creatures that aren't the intended targets. Plants, bacteria, and insects are used to create biopesticides, they used in controlling diseases in crops. Microbial pesticides are produced from different microorganisms such as Trichoderma, Bacillus, Pseudomonas, and Beauveria. Also, botanical pesticides have already been commercialized; they are extracted from neem, pyrethrum, azadirachtin, etc. This paper describes biopesticide categories, their sources, mode of action, advantages and disadvantages, and their role in sustainable agriculture.

Keywords: biopesticides categories, formulation, mode of action, pest control

Procedia PDF Downloads 67
3889 Organic Fertilizers Mitigate Microplastics Toxicity in Agricultural Soil

Authors: Ghulam Abbas Shah, Maqsood Sadiq, Ahsan Yasin

Abstract:

Massive global plastic production, combined with poor degradation and recycling, leads to significant environmental pollution from microplastics, whose effects on plants in the soil remain understudied. Besides, effective mitigation strategies and their impact on ammonia (NH₃) emissions under varying fertilizer management practices remains sketchy. Therefore, the objectives of the study were (i) to determine the impact of organic fertilizers on the toxicity of microplastics in sorghum and physicochemical characteristics of microplastics-contaminated soil and (ii) to assess the impacts of these fertilizers on NH₃ emissions from this soil. A field experiment was conducted using sorghum as a test crop. Treatments were: (i) Control (C), (ii) Microplastics (MP), (iii) Inorganic fertilizer (IF), (iv) MPIF, (v) Farmyard manure (FM), (vi) MPFM, (vii) Biochar (BC), and (viii) MPBC, arranged in a randomized complete block design (RCBD) with three replicates. Microplastics of polyvinyl chloride (PVC) were applied at a rate of 1.5 tons ha-¹, and all fertilizers were applied at the recommended dose of 90 kg N ha-¹. Soil sampling was done before sowing and after harvesting the sorghum, with samples analyzed for chemical properties and microbial biomass. Crop growth and yield attributes were measured. In a parallel pot experiment, NH₃ emissions were measured using passive flux samplers over 72 hours following the application of treatments similar to those used in the field experiment. Application of MPFM, MPBC and MPIF reduced soil mineral nitrogen by 8, 20 and 38% compared to their sole treatments, respectively. Microbial biomass carbon (MBC) was reduced by 19, 25 and 59% in MPIF, MPBC and MPFM as compared to their sole application, respectively. Similarly, the respective reduction in microbial biomass nitrogen (MBN) was 10, 27 and 66%. The toxicity of microplastics was mitigated by MPFM and MPBC, each with only a 5% reduction in grain yield of sorghum relative to their sole treatments. The differences in nitrogen uptake between BC vs. MPBC, FM vs. MPFM, and IF vs. MPIF were 8, 10, and 12 kg N ha-¹, respectively, indicating that organic fertilizers mitigate microplastic toxicity in the soil. NH₃ emission was reduced by 5, 11 and 20% after application of MPFM, MPBC and MPIF than their sole treatments, respectively. The study concludes that organic fertilizers such as FM and BC can effectively mitigate the toxicity of microplastics in soil, leading to improved crop growth and yield.

Keywords: microplastics, soil characteristics, crop n uptake, biochar, NH₃ emissions

Procedia PDF Downloads 42
3888 Effect of Low Level Laser Therapy versus Polarized Light Therapy on Oral Mucositis in Cancer Patients Receiving Chemotherapy

Authors: Andrew Anis Fakhrey Mosaad

Abstract:

The goal of this study is to compare the efficacy of polarised light therapy with low-intensity laser therapy in treating oral mucositis brought on by chemotherapy in cancer patients. Evaluation procedures are the measurement of the WHO oral mucositis scale and the Common toxicity criteria scale. Techniques: Cancer patients (men and women) who had oral mucositis, ulceration, and discomfort and whose ages varied from 30 to 55 years were separated into two groups and received 40 chemotherapy treatments. Twenty patients in Group (A) received low-level laser therapy (LLLT) along with their regular oral mucositis medication treatment, while twenty patients in Group (B) received Bioptron light therapy (BLT) along with their regular oral mucositis medication treatment. Both treatments were applied for 10 minutes each day for 30 days. Conclusion and results: This study showed that the use of both BLT and LLLT on oral mucositis in cancer patients following chemotherapy greatly improved, as seen by the sharp falls in both the WHO oral mucositis scale (OMS) and the common toxicity criteria scale (CTCS). However, low-intensity laser therapy (LLLT) was superior to Bioptron light therapy in terms of benefits (BLT).

Keywords: Bioptron light therapy, low level laser therapy, oral mucositis, WHO oral mucositis scale, common toxicity criteria scale

Procedia PDF Downloads 246
3887 Configuration Design and Optimization of the Movable Leg-Foot Lunar Soft-Landing Device

Authors: Shan Jia, Jinbao Chen, Jinhua Zhou, Jiacheng Qian

Abstract:

Lunar exploration is a necessary foundation for deep-space exploration. For the functional limitations of the fixed landers which are widely used currently and are to expand the detection range by the use of wheeled rovers with unavoidable path-repeatability, a movable lunar soft-landing device based on cantilever type buffer mechanism and leg-foot type walking mechanism is presented. Firstly, a 20 DoFs quadruped configuration based on pushrod is proposed. The configuration is of the bionic characteristics such as hip, knee and ankle joints, and can make the kinematics of the whole mechanism unchanged before and after buffering. Secondly, the multi-function main/auxiliary buffers based on crumple-energy absorption and screw-nut mechanism, as well as the telescopic device which could be used to protect the plantar force sensors during the buffer process are designed. Finally, the kinematic model of the whole mechanism is established, and the configuration optimization of the whole mechanism is completed based on the performance requirements of slope adaptation and obstacle crossing. This research can provide a technical solution integrating soft-landing, large-scale inspection and material-transfer for future lunar exploration and even mars exploration, and can also serve as the technical basis for developing the reusable landers.

Keywords: configuration design, lunar soft-landing device, movable, optimization

Procedia PDF Downloads 159