Search results for: toxic metals

Authors: T. Hojageldiyev, Y. Bolmammedov, S. Gurbanaliyev

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It is known that drugs used in the treatment of tuberculosis show toxic effect to organism especially to liver besides its therapeutic effect. Because of ineffectiveness of drugs used in the treatment regimen of tuberculosis against multidrug resistance (MDR) and extensively drug-resistance (XDR) tuberculosis requires the development of new treatment methods and new, novel drugs. Considering the usage of Artemisia absinthium in traditional medicine in treatment of wounds which suggests its antibacterial activity it seems that, also it may have significant antimycobacterial activity. The objective of present study was to evaluate antibacterial activity of ethanolic extract of A. absinthium against M. tuberculosis. In this study, the effect of ethanolic extract of A. absinthium was tested against tuberculosis and pharmaco-toxicological properties evaluated on laboratory animals. The 20%, 40%, 70% and 96% ethanolic extracts of A. absinthium prepared then its bacteriostatic and bactericidal activities were evaluated by validated methods. Data were analyzed by GraphPad Prism 7.0 at the level P < 0.05. Results showed that ethanolic extracts of A. absinthium show no toxicological properties with having high LD50. All concentrations of extract show high bacteriostatic activity on M. tuberculosis. 96% ethanolic extract has highest bactericidal effect among other concentrations. By conducting further studies, as a result of our study, antimycobacterial drug can be prepared from A. absinthium.

Keywords: Artemisia absinthium, antimycobacterial, ethanolic extract, Mycobacteria tuberculosis

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Authors: Sanam Pudasaini, A. T. K. Perera, Ahmed Syed Shaheer Uddin, Sum Huan Ng, Chun Yang

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Development of high-efficiency and environment friendly bacterial inactivation methods is of great importance for preventing waterborne diseases which are one of the leading causes of death in the world. Traditional bacterial inactivation methods (e.g., ultraviolet radiation and chlorination) have several limitations such as longer treatment time, formation of toxic byproducts, bacterial regrowth, etc. Recently, an electroporation-based inactivation method was introduced as a substitute. Here, an electroporation-based continuous flow microfluidic device equipped with an array of micropillars is developed, and the device achieved high bacterial inactivation performance ( > 99.9%) within a short exposure time ( < 1 s). More than 99.9% reduction of Escherichia coli bacteria was obtained for the flow rate of 1 mL/hr, and no regrowth of bacteria was observed. Images from scanning electron microscope confirmed the formation of electroporation-induced nano-pore within the cell membrane. Through numerical simulation, it has been shown that sufficiently large electric field strength (3 kV/cm), required for bacterial electroporation, were generated using PDMS micropillars for an applied voltage of 300 V. Further, in this method of inactivation, there is no involvement of chemicals and the formation of harmful by-products is also minimum.

Keywords: electroporation, high-efficiency, inactivation, microfluidics, micropillar

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Authors: John O. Akindoyo, M. D. H. Beg, Suriati Binti Ghazali, Nitthiyah Jeyaratnam

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Regeneration of bone due to the many health challenges arising from traumatic effects of bone loss, bone tumours and other bone infections is fast becoming indispensable. Over the period of time, some approaches have been undertaken to mitigate this challenge. This includes but not limited to xenografts, allografts, autografts as well as artificial substitutions like bioceramics, synthetic cements and metals. However, most of these techniques often come along with peculiar limitation and problems such as morbidity, availability, disease transmission, collateral site damage or absolute rejection by the body as the case may be. Hydroxyapatite (HA) is very compatible and suitable for this application. However, most of the common methods for HA synthesis are expensive and environmentally unfriendly. Extraction of HA from bio-wastes have been perceived not only to be cost effective, but also environment-friendly. In this research, HA was produced from bio-waste: namely bovine bones through a combination of hydrothermal chemical processes and ordinary calcination techniques. Structure and property of the HA was carried out through different characterization techniques (such as TGA, FTIR, DSC, XRD and BET). The synthesized HA was found to possess similar properties to stoichiometric HA with highly desirable thermal, degradation, structural and porous properties. This material is unique for its potential minimal cost, environmental friendliness and property controllability. It is also perceived to be suitable for tissue and bone engineering applications.

Keywords: biomaterial, biopolymer, bone, hydroxyapatite

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Authors: Brian J. Graham, Ronald T. Raines

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The presence of a nearly vacant p orbital on boron endows boronic acids with unique abilities as a catalyst and ligand. An organocatalytic process has been developed for the conversion of biomass-derived sugars to 5-hydroxymethylfurfural, which is a platform chemical. Specifically, 2-carboxyphenylboronic acid (2-CPBA) has been shown to be an optimal catalyst for this process, promoting the desired transformation in the absence of metals. The attributes of 2-CPBA as a catalyst led to additional investigations of its structure and reactivity. 2-CPBA was found to exist as a cyclized benzoxaborolone adduct rather than a free carboxylic acid. This cyclization has profound consequences for the oxidative stability of the boronic acid. Stereoelectronic effects within the oxaborolone ring destabilize the oxidation transition state by reducing electron donation from the cyclic oxygen to the developing p orbital on boron. That leads to a 10,000-fold increase in oxidative stability while maintaining the normal reactivity of boronic acids toward diols (e.g., carbohydrates) and nucleophiles in proteins while also presenting numerous hydrogen-bond accepting and donating groups. Thus, benzoxaborolones are useful in catalysis, chemical biology, medicinal chemistry, and allied fields.

Keywords: bioisosteres, boronic acid, catalysis, oxidative stability, pharmacophore, stereoelectronic effects

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Authors: Jayati Das

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Kolkata, one of the fastest-growing metropolises in India, has been suffering from air pollution for many decades. Mismanagement of government and an increase in automobiles have been fuelling this problem. The study aims to portray the quality of air along with the influence of traffic flow and vehicular growth and the effects on human health. It further shows the correlation between the emission of pollution during weekdays and weekends with the help of a scatter diagram and trend line. An assessment of Kolkata air quality is done where the listed pollutants’ (RPM, SPM, NO2, and SO2) annual average concentrations are classified into four different categories. Our observed association between childhood Acute Respiratory disorder and early life exposure to traffic-related air pollutants is biologically plausible. The period of in utero and the first year of life is critical in the development of the immune and respiratory systems and potentially harmful effects of toxic pollutants during this period might result in the long-lasting impaired capacity to fight infections and increased risk of allergic manifestations. Up-to-date knowledge about the seasonal and spatial variation of asthma and studying the air quality of the area is done through Geographical Information System (GIS). Steps are taken by the government to control air pollution by alternative public transport like the metro and compulsory certification of period-driven vehicles which test for Carbon mono oxide.

Keywords: air pollution, asthma, GIS, hotspots, governance

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

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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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Authors: Yi-Jie Lin, Jyh-Cherng Chen

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The fly ash of waste incineration processes is usually hazardous and the disposal or reuse of waste incineration fly ash is difficult. In this study, the waste incineration fly ash was converted to useful zeolites by the alkali fusion and hydrothermal synthesis method. The influence of different operating conditions (the ratio of Si/Al, the ratio of hydrolysis liquid to solid, and hydrothermal time) was investigated to seek the optimum operating conditions for the synthesis of zeolite from waste incineration fly ash. The results showed that concentrations of heavy metals in the leachate of Toxicity Characteristic Leaching Procedure (TCLP) were all lower than the regulatory limits except lead. The optimum operating conditions for the synthesis of zeolite from waste incineration fly ash by the alkali fusion and hydrothermal synthesis method were Si/Al=40, NaOH/ash=1.5, alkali fusion at 400 ^oC for 40 min, hydrolysis with Liquid to Solid ratio (L/S)= 200 at 105 ^oC for 24 h, and hydrothermal synthesis at 105 ^oC for 24 h. The specific surface area of fly ash could be significantly increased from 8.59 m²/g to 651.51 m²/g (synthesized zeolite). The influence of different operating conditions on the synthesis of zeolite from waste incineration fly ash followed the sequence of Si/Al ratio > hydrothermal time > hydrolysis L/S ratio. The synthesized zeolites can be reused as good adsorbents to control the air or wastewater pollutants. The purpose of fly ash detoxification, reduction and waste recycling/reuse is achieved successfully.

Keywords: alkali fusion, hydrothermal, fly ash, zeolite

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Authors: Kayla Fanning

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Theocritus’ use of near-pastoral motifs in creating the lamenting narrative in “The Sorceress” idyll suggests a link between Simaetha and the quintessential shepherd that ultimately transcends the bucolic serenading structure, evident in “The Serenade”, as it pertains to depictions of women. In Theocritus’ “The Serenade”, an anonymous goatherd serenades his beloved, Amaryllis, in hopes of persuading her to reciprocate his love. This serenade soon turns into a vicious lament where all hope for reciprocation dissolves, leaving the goatherd severely melancholic and malignant. In “The Cyclops’ Serenade”, the cyclops, Polyphemus, sings of Galatea in solitude; in so doing, he negotiates between feelings of heartache and anger that eventually subside. His depiction of Galatea, in being less vindictive than the goatherd’s, manifests less toxicity. In adopting, and essentially creating, this serenading structure, Theocritus illustrates his ability to alter portrayals of women while maintaining the premise of the pastoral serenade; that is the shepherd's lament of his indifferent beloved. A thematic intertextual analysis of the idylls reveals a variety of ways in which the toxicity of the goatherd’s relation to Amaryllis is mutated or even inverted. In “The Sorceress”, a powerful witch named Simaetha spellbinds her unfaithful lover and angrily laments his betrayal in a way that is reminiscent of the goatherd's harmful behavior towards Amaryllis.

Keywords: femininity, pastoral, serenade, Theocritus

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Authors: Feng Xu, Zhaozhi Liu, Junhua Xu, Xiaolong Tang, Dunwen Zuo

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Chemical vapor deposition (CVD) diamond coated cutting tool has excellent cutting performance, it is the most ideal tool for the processing of nonferrous metals and alloys, composites, nonmetallic materials and other difficult-to-machine materials efficiently and accurately. Depositing CVD diamond coating on the cemented carbide with high cobalt content can improve its toughness and strength, therefore, it is very important to research on the preparation technology and cutting properties of CVD diamond coated cemented carbide cutting tool with high cobalt content. The preparation technology of boron-doped diamond (BDD) coating has been studied and the coated drills were prepared. BDD coating were deposited on the drills by using the optimized parameters and the SEM results show that there are no cracks or collapses in the coating. Cutting tests with the prepared drills against the silumin and aluminum base printed circuit board (PCB) have been studied. The results show that the wear amount of the coated drill is small and the machined surface has a better precision. The coating does not come off during the test, which shows good adhesion and cutting performance of the drill.

Keywords: cemented carbide with high cobalt content, CVD boron-doped diamond, cutting test, drill

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Authors: Gul Afreen, Sreedevi Upadhyayula, Mahendra K. Sunkara

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One-dimensional (1D) nanostructures like nanowires, nanotubes, and nanorods find variety of practical application owing to their unique physico-chemical properties. In this work, TiO₂ nanowires were synthesized by direct oxidation of titanium particles in a unique microwave plasma jet reactor. The prepared TiO₂ nanowires manifested the flexible features, and were characterized by using X-ray diffraction, Brunauer-Emmett-Teller (BET) surface area analyzer, UV-Visible and FTIR spectrophotometers, Scanning electron microscope, and Transmission electron microscope. Further, the photodegradation efficiency of these nanowires were tested against toxic organic dye like methylene blue (MB) and the results were compared with the commercial TiO₂. It was found that TiO₂ nanowires exhibited superior photocatalytic performance (89%) as compared to commercial TiO₂ (75%) after 60 min of reaction. This is attributed to the lower recombination rate and increased interfacial charge transfer in TiO₂ nanowire. Pseudo-first order kinetic modelling performed with the experimental results revealed that the rate constant of photodegradation in case of TiO₂ nanowire was 1.3 times higher than that of commercial TiO₂. Superoxide radical (O₂˙⁻) was found to be the major contributor in the photodegradation mechanism. Based on the trapping experiments, a plausible mechanism of the photocatalytic reaction is discussed.

Keywords: heterogeneous catalysis, photodegradation, reactive oxygen species, TiO₂ nanowires

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Authors: Zakia Alioua, Amira Soumia, Zerouali-Khodja Fatiha

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In spite of a wide variety of contaminants such as heavy metals and organic compounds in addition to the importance of extended pollution, the deep-sea and its species are not in haven and being affected through contaminants exposure. This investigation is performed in order to provide data on the presence of pathological changes in the liver and gonads of the greater forkbeard. A total of 998 specimens of the teleost fish Phycis blennoides Brünnich, 1768 ranged from 5,7 to 62,7 cm in total length, were obtained from the commercial fisheries of Algerian ports. The sampling has been carried out monthly from December 2013 to June 2015 and from January to June 2016 caught by trawlers and longlines between 75 and 600 fathoms in the coast of Algeria. Individuals were sexed their gonads, and their livers were removed and processed for light microscopy and one case of atresia was identified. In whole, overall 0,002% of the specimens presented some degree of liver steatosis. For the gastric section, 442 selected stomachs contents were observed looking for parasitic infestation and enumerate 212 nematodes. A prospecting survey for metal contaminant was performed on the liver by atomic absorption spectrophotometry analysis.

Keywords: atresia, coast of Algeria, histopathology, nematode, Phycis blennoides, steatosis

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Authors: V. Veena, Suguna Yesodharan, E. P. Yesodharan

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Two Advanced Oxidation Processes (AOP) i.e., sono- and photo-catalysis mediated by semiconductor oxide catalyst, ZnO has been found effective for the removal of trace amounts of the toxic dye pollutant Indigocarmine (IC) from water. The effect of various reaction parameters such as concentration of the dye, catalyst dosage, temperature, pH, dissolved oxygen etc. as well as the addition of oxidisers and presence of salts in water on the rate of degradation has been evaluated and optimised. The degradation follows variable kinetics depending on the concentration of the substrate, the order of reaction varying from 1 to 0 with increase in concentration. The reaction proceeds through a number of intermediates and many of them have been identified using GCMS technique. The intermediates do not affect the rate of degradation significantly. The influence of anions such as chloride, sulphate, fluoride, carbonate, bicarbonate, phosphate etc. on the degradation of IC is not consistent and does not follow any predictable pattern. Phosphates and fluorides inhibit the degradation while chloride, sulphate, carbonate and bicarbonate enhance. Adsorption studies of the dye in the absence as well as presence of these anions show that there may not be any direct correlation between the adsorption of the dye on the catalyst and the degradation. Oxidants such as hydrogen peroxide and persulphate enhance the degradation though the combined effect and it is less than the cumulative effect of individual components. COD measurements show that the degradation proceeds to complete mineralisation. The results will be presented and probable mechanism for the degradation will be discussed.

Keywords: AOP, COD, indigocarmine, photocatalysis, sonocatalysis

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Authors: A. M. El-Aziz, M. Elsehamy, H. Hussein

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Steel or stainless steel have reasonable corrosion behavior in water, their corrosion resistance is significantly dependent on the water purity. It was not expected that demineralized water has an aggressive effect on steel alloys, in this study, the effect of water with different purity on steel X52 and stainless steel 316L was investigated. Weight loss and electrochemical measurements were employed to measure the corrosion behavior. Samples were microscopically investigated after test. It was observed that the higher the water purity the more reactive it is. Comparative analysis of the potentiodynamic curves for different water purity showed the aggressiveness of the demineralised water (conductivity of 0.05 microSiemens per cm) over the distilled water. Whereas, the corrosion rates of stainless steel 858 and 623 nm/y for demi and distilled water respectively. On the other hand, the corrosion rates of carbon steel x52 were estimated about 4.8 and 3.6 µm/y for demi and distilled water, respectively. Open circuit potential (OCP) recorded more positive potentials in case of stainless steel than carbon steel in different water purities. Generally, stainless steel illustrated high pitting resistance than carbon steel alloy, the surface film was investigated by scanning electron microscopy (SEM) and analyzed by energy dispersive X-ray spectroscopy (EDX). This behavior was explained based on that demi and distilled water might be considered as ‘hungry water’ in which it wants to be in equilibrium and will pull ions out of the surrounding metals trying to satisfy its ‘hunger’.

Keywords: corrosion, demineralized water, distilled water, steel alloys

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Authors: Amal Yamani, Jaber Elgtou, Aziz Mohammed, Lazaar Jamila, Elachouri Mostafa

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Peganum harmala used traditionally as an emenagogue and abortifacient agent in Morocco phytotherapy. Even thought its benefits effects, Peganum harmala remained severely toxic for the organism especially in strong doses. The present study was initiated to evaluate the nephrotoxic effects of aqueous extract of Peganum harmala seeds (PHS). The solution containing aqueous extract of PHS was administered orally by gavage at the dose of 2g/kg body weight during twenty days. Rats were used in this study, two groups were considered, a treated group received an extract of PHS at dose 2g/kg bodyweight and control group received an amount of tap water equivalent to the volume of the vehicle used for the dose of PHS extract. The data we collected showed that aqueous extracts of PHS administered during twenty days induced a significant changes in renal function expressed in decreases of diuresis (from 10 ± 0,58 to 5,33 ± 0,33 ml/24 hours) and the same profile for mean arterial blood pressure (from 125 ± 2,89 to 96,67 ± 6,01 mmHg). The histopathological study showed an alteration of kidney cells in treated group with regard the control group which is not affected. In conclusion: our results indicate that the aqueous extract of PHS induces toxicity may affect severely kidney function and causes renal histopathology.

Keywords: peganum harmala seeds, nephrotoxic, diuresi, histpathology, kidney

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Authors: Abbas Hani

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In recent decades with the development of technology and lack of food sources, sewage sludge in production of human foods is inevitable. Various sources of municipal and industrial sewage sludge that is produced can provide the requirement of plant nutrients. Soils in arid, semi-arid climate of central Iran that most affected by water drainage, iron and zinc deficiencies, using of sewage sludge is helpful. Therefore, the aim of this study is investigation of sewage sludge and manure application on Ni and Zn uptake by Savory. An experiment in a randomized complete block design with three replications was performed. Sewage sludge treatments consisted of four levels, control, 15, 30, 80 tons per hectares, the manure was used in four levels of control, 20, 40 and 80 tons per hectare. Results showed that the wet and dry weights was not affected by sewage sludge using, while, manure has significant effect on them. The effect of sewage sludge on the cadmium and lead concentrations were significant. Interactions of sewage sludge and manure on dry weight values were not significant. Compare mean analysis showed that increasing the amount of sewage sludge had no significant effect on cadmium concentration and it reduced when sewage sludge usage increased. This is probably due to increased plant growth and reduced concentrations of these elements in the plant.

Keywords: savory, lead, cadmium, sewage sludge, manure

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Authors: Y. K. Leong, J. C. W. Lan, H. S. Loh, P. L. Show

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Being biodegradable, non-toxic, renewable and have similar or better properties as commercial plastics, polyhydroxy alkanoates (PHAs) can be a potential game changer in the polymer industry. PHAs are the biodegradable polymer produced by bacteria, which are in interest as a sustainable alternative to petrochemical-derived plastics; however, its commercial value has significantly limited by high production and recovery cost of PHA. Aqueous two-phase system (ATPS) offers different chemical and physical environments, which contains about 80-90% water delivers an excellent environment for partitioning of cells, cell organelles and biologically active substances. Extractive bioconversion via ATPS allows the integration of PHA upstream fermentation and downstream purification process, which reduces production steps and time, thus lead to cost reduction. The ability of Ralstonia eutropha to grow under different ATPS conditions was investigated for its potential to be used in a bioconversion system. Changes in tie-line length (TLL) and a volume ratio (Vr) were shown to have an effect on PHA partition coefficient. High PHA recovery yield of 65% with a relatively high purity of 73% was obtained in PEG 6000/Sodium sulphate system with 42.6 wt/wt % TLL and 1.25 Vr. Extractive bioconversion via ATPS is an attractive approach for the combination of PHA production and recovery process.

Keywords: aqueous two-phase system, extractive bioconversion, polyhydroxy alkanoates, purification

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Authors: Anjana Goel, Ashok Kumar Bhatia

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Ocimum sanctum, a well known medicinal plant is used for various alignments in Ayurvedic medicines. It was found to be effective in treating the humans suffering from different viral infections like chicken pox, small pox, measles and influenza. In addition, curative effect of the plant in malignant patients was also reported. In the present study, leaves of this plant were screened against animal viruses i.e. Bovine Herpes Virus-type-1 (BHV-1), Foot and Mouth disease virus (FMDV) and Newcastle Disease Virus (NDV). BHV-1 and FMDV were screened in MDBK and BHK cell lines respectively using cytopathic inhibition test. While NDV was propagated in chick embryo fibroblast culture and tested by haemagglutination inhibition test. Maximum non toxic dose of aqueous extract of Ocimum sanctum leaves was calculated by MTT assay in all the cell cultures and nontoxic doses were used for antiviral activity against viruses. 98.4% and 85.3% protection were recorded against NDV and BHV-1 respectively. However, Ocimum sanctum extract failed to show any inhibitory effect on the cytopathic effect caused by FMD virus. It can be concluded that Ocimum sanctum is a very effective remedy for curing viral infections in animals also.

Keywords: bovine herpes virus-type-1, foot and mouth disease virus, newcastle disease virus, Ocimum sanctum

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Authors: Maris Klavins, Valery Rodinov

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The aim of this study was to analyze long term changes of surface water quality in Latvia, spatial variability of water chemical composition, possible impacts of different pollution sources as well as to analyze the measures to protect national water resources - river basin management. Within this study, the concentrations of major water ingredients and microelements in major rivers and lakes of Latvia have been determined. Metal concentrations in river and lake waters were compared with water chemical composition. The mean concentrations of trace metals in inland waters of Latvia are appreciably lower than the estimated world averages for river waters and close to or lower than background values, unless regional impacts determined by local geochemistry. This may be explained by a comparatively lower level of anthropogenic load. In the same time in several places, direct anthropogenic impacts are evident, regarding influences of point sources both transboundary transport impacts. Also, different processes related to pollution of surface waters in Latvia have been analyzed. At first the analysis of changes and composition of pollutant emissions in Latvia has been realized, and the obtained results were compared with actual composition of atmospheric precipitation and their changes in time.

Keywords: water quality, trend analysis, pollution, human impact

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Authors: S. Taghvamanesh

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Modern landfills are highly engineered containment systems that are designed to reduce the environmental and human health impacts of solid waste (trash). In modern landfills, waste is contained by a liner system. The primary goal of the liner system is to isolate the landfill contents from the environment, thereby protecting the soil and groundwater from pollution caused by the leachate of a landfill. Landfill leachate is the most serious threat to groundwater. Therefore, it is necessary to design a system that prevents the penetration of this dangerous substance into the environment. These layers are made up of two basic elements: clay and geosynthetics. Hydraulic conductivity and flexibility are two desirable properties of these materials. There are three different types of liner systems that will be discussed in this paper. According to available data, the current article analyzed materials and methods for constructing liner layers made of distinct leachates, including various harmful components and heavy metals from all around the world. Also, this study attempted to gather data on leachates for each of the sites discussed. In conclusion, every landfill requires a specific type of liner, which depends on the type of leachate that it produces daily. It should also be emphasized that, based on available data, this article focused on the number of landfills that each country or continent possesses.

Keywords: landfill, liner layer, impervious layer, barrier layer

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Authors: Manasi Roy, Raju Mondal

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During last two decades the synthesis and design of MOFs or novel coordination polymers (CPs) has flourished as an emerging area of research due to their role as functional materials. Accordingly, ten new cobalt-based MOFs have been synthesized using a simple bispyrazole ligand, 4,4′-methylene-bispyrazole (H2MBP), and isophthalic acid (H2IPA) and its four 5-substituted derivatives R-H2IPA (R = COOH, OH, tBu, NH2). The major aim of this study was to validate the mutual influence of temperature and substitutions on the final structural self-assembly. Five different isophthalic acid derivatives were used to study the influence of substituents while each reaction was carried out at two different temperatures to assess the temperature effect. A clear correlation was observed between the reaction temperature and the coordination number of the cobalt atoms which consequently changes the self assembly pattern. Another fact that the periodical change in coordination number did bring about some systematic changes in the structural network via secondary building unit selectivity. With the presence of a tunable cavity inside the network, and unsaturated metal centers, MOFs show highly encouraging photocatalytic degradation of toxic dye with a potential application in waste water purification. Another fascinating aspect of this work is the construction of magnetic coordination polymers with the occurrence of a not-so-common MCE behavior of cobalt-based MOF.

Keywords: MOFs, temperature effect, MCE, dye degradation

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Authors: Sathish Sundar Dhilip Kumar, Nicolette Houreld, Heidi Abrahamse

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Silver nanoparticles (AgNPs) are classified as metal-based nanomaterials and have received considerable attention globally for wound healing and tissue engineering applications. Naturally available materials are a significant source of medicinal products to treat numerous diseases; polysaccharides are among them. Polysaccharides are non-toxic, safe, and inexpensive, and it has good biocompatibility and biodegradability. Most polysaccharides are shown to have a positive effect on wound healing processes, including chitosan and gum tragacanth. The present study evaluated the improvement of cellular wound healing by nanosilver-loaded polysaccharide-based biomaterial (CGT-NS) in WS1 cells. The physicochemical properties of prepared CGT-NS were studied using different characterization techniques, and it exhibited better stability and swelling properties in various pH conditions. Surface morphology was studied using scanning electron microscopy, and it revealed the porous morphology of the synthesized CGT-NS. The synthesized biomaterial displayed acceptable antibacterial properties against Gram-positive and Gram-negative bacterial strains, and it may prevent infection. The biocompatibility of the synthesized CGT-NS biomaterial was studied in WS1 cells, where it may lead to promote increased cell adhesion and proliferation properties. Thus, the CGT-NS biomaterial has good potential as a biomaterial in wound healing applications.

Keywords: biomaterial, wound healing, nano, silver nanoparticles

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Authors: George Madalin Danila, Mihaiella Cretu, Cristian Puscasu

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Glycol-based anti-freeze liquids, commonly composed of ethylene glycol or propylene glycol, have important uses in automotive cooling, but they should be handled with care due to their toxicity; ethylene glycol is highly toxic to humans and animals. A fast, accurate, precise, and robust method was developed for the simultaneous quantification of 7 most important glycols and their isomers. Glycols were analyzed from diluted sample solution of coolants using gas-chromatography coupled with mass spectrometry in single ion monitoring mode. Results: The method was developed and validated for 7 individual glycols (ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol). Limits of detection (1-2 μg/mL) and limit of quantification (10 μg/mL) obtained were appropriate. The present method was applied for the determination of glycols in 10 different anti-freeze liquids commercially available on the Romanian market, proving to be reliable. A method that requires only a two-step dilution of anti-freeze samples combined with direct liquid injection GC-MS was validated for the simultaneous quantification of 7 glycols (and their isomers) in 10 different types of anti-freeze liquids. The results obtained in the validation procedure proved that the GC-MS method is sensitive and precise for the quantification of glycols.

Keywords: glycols, anti-freeze, gas-chromatography, mass spectrometry, validation, recycle

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Authors: Harmel Meriem

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The optoelectronic properties and high power conversion efficiency make lead halide perovskites ideal material for solar cell applications. However, the toxic nature of lead and the instability of organic cation are the two key challenges in the emerging perovskite solar cells. To overcome these challenges, we present our study about finding potential alternatives to lead in the form of A2BX6 perovskite using the first principles DFT-based calculations. The highly accurate modified Becke Johnson (mBJ) and hybrid functional (HSE06) have been used to investigate the Main Document Click here to view linked References to optoelectronic and thermoelectric properties of A2PdBr6 (A = K, Rb, and Cs) perovskite. The results indicate that different A-cations in A2PdBr6 can significantly alter their electronic and optical properties. Calculated band structures indicate semiconducting nature, with band gap values of 1.84, 1.53, and 1.54 eV for K2PdBr6, Rb2PdBr6, and Cs2PdBr6, respectively. We find strong optical absorption in the visible region with small effective masses for A2PdBr6. The ideal band gap and optimum light absorption suggest Rb2PdBr6 and Cs2PdBr6 potential candidates for the light absorption layer in perovskite solar cells. Additionally.

Keywords: soler cell, double perovskite, optoelectronic properties, ab-inotio study

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Authors: Shivam Yadav, Neelam Atri

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Cyanobacteria, the photosynthetic prokaryotes are indispensable components of paddy soil contribute substantially to the nitrogen economy however often appended with metal load. They are well known to play crucial roles in maintenance of soil fertility and rice productivity. Nickel is one such metal that plays a vital role in the cellular physiology, however at higher concentrations it exerts adverse effects. Arsenic is another toxic metalloid that negatively affects the cyanobacterial proliferation. However species-specific comparative responses under As and Ni is largely unknown. The present study focuses on the comparative effects of nickel (Ni2+) and arsenite (As(III)) on two diazotrophic cyanobacterial species (Anabaena doliolum and Anabaena sp. PCC7120) in terms of antioxidative aspects. Oxidative damage measured in terms of lipid peroxidation and peroxide content was significantly higher after As(III) than Ni treatment as compared to control. Similarly, all the studied enzymatic and non-enzymatic parameters of antioxidative defense system except glutathione reductase (GR) showed greater induction against As(III) than Ni. Moreover, integrating comparative analysis of all studied parameters also demonstrated interspecies variation in terms of stress adaptive strategies reflected through higher sensitivity of Anabaena doliolum over Anabaena PCC7120.

Keywords: antioxidative system, arsenic, cyanobacteria, nickel

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Authors: Faisal A. Salih

Abstract:

Verapamil hydrochloride (Ver) is a drug used in medicine for arrythmia, angina and hypertension as a calcium channel blocker. For the quantitative determination of Ver in dosage forms, the HPLC method is most often used. A convenient alternative to the chromatographic method is potentiometry using a Verselective electrode, which does not require expensive equipment, can be used without separation from the matrix components, which significantly reduces the analysis time, and does not use toxic organic solvents, being a "green", "environmentally friendly" technique. It has been established in this study that the rational choice of the membrane plasticizer and the preconditioning and measurement algorithms, which prevent nonexchangeable extraction of Ver into the membrane phase, makes it possible to achieve excellent analytical characteristics of Ver-selective electrodes based on commercially available components. In particular, an electrode with the following membrane composition: PVC (32.8 wt %), ortho-nitrophenyloctyl ether (66.6 wt %), and tetrakis-4-chlorophenylborate (0.6 wt % or 0.01 M) have the lower detection limit 4 × 10−8 M and potential reproducibility 0.15–0.22 mV. Both direct potentiometry (DP) and potentiometric titration (PT) methods can be used for the determination of Ver in tablets and injection solutions. Masses of Ver per average tablet weight determined by the methods of DP and PT for the same set of 10 tablets were (80.4±0.2 and80.7±0.2) mg, respectively. The masses of Ver in solutions for injection, determined by DP for two ampoules from one set, were (5.00±0.015 and 5.004±0.006) mg. In all cases, good reproducibility and excellent correspondence with the declared quantities were observed.

Keywords: verapamil, potentiometry, ion-selective electrode, pharmaceutical analysis

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Authors: M. G. Mostafa, Manjushree Chowdhury, Tapan Kumar Biswas, , Ananda Kumar Saha

Abstract:

This study focused on effluents characterization and treatment process to reduce of toxicity from tannery effluents. Tanning industry is one of the oldest industries in the world. It is typically characterized as pollutants generated industries which produce wide varieties of high strength toxic chemicals. The study was conducted during the year 2008 to 2009 and the tannery effluents were collected three times in a year from the outlet of some selected leather industries located in Hagaribagh industrial zone Dhaka, Bangladesh. The analysis results of the raw effluents reveal that the effluents were yellowish-brown color, having basic pH, very high value of BOD5¬¬, COD, TDS, TSS, TS, and high concentrations of Cr, Na, SO42-, Cl- and other organic and inorganic constituents. The tannery effluents were treated with various doses of FeCl3 after settling and a subsequent filtration through sand-stone. The study observed that coagulant (FeCl3) 150 mg/L dose around neutral pH showed the best removal efficiency for major physico-chemical parameters. The analysis results of illustrate that the most of the physical and chemical parameters were found well below the prescribed permissible limits for effluent discharged. The study suggests that tannery effluents could be treated by a combined process consisting of settling, filtering and coagulating with FeCl3.

Keywords: characterization, effluent, tannery, treatment

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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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Authors: C. Lopez, S. Dourdain, G. Arrachart, S. Pellet-Rostaing

Abstract:

Ionic liquids (ILs) are considered a good alternative for organic solvents in extractive processes; however, the higher or lower extraction efficiency in ILs remains difficult to predict because a lack of understanding of the extraction mechanisms in this class of diluents, making their application difficult to generalize. We have studied the extraction behavior of La(III) and Eu(III) from aqueous solution into n-dodecane and two ionic liquids (ILs), 1-ethyl-1-butylpiperidinium bis (trifluoromethylsulfonyl)imide [EBPip⁺] [NTf₂⁻] and 1-ethyl-1-octylpiperidinium bis (trifluoromethylsulfonyl)imide [EOPip⁺] [NTf₂⁻], at room temperature using N,N’- dimethyl- N,N’-dioctylhexylethoxymalonamide (DMDOHEMA) as extractant. Fe(III) was introduced to the aqueous phase in order to study the selectivity toward La(III) and Eu(III) and the effect of variation of PH was investigated by using of several HNO₃ concentrations. We found that the ionic liquid with shorter alkyl chain [EBPip⁺] [NTf₂⁻] showed a higher extraction ability than [EOPip⁺] [NTf₂⁻] and that the use of ILs as organic solvent instead n-dodecane, greatly enhanced the extraction percentage of the target metals with a good selectivity. Cation ([EBPip⁺] or [EOPip⁺]) and anion ([NTf₂⁻]) concentration in the aqueous phase, has been determined in order to elucidate the extraction mechanism.

Keywords: extraction mechanism, ionic liquids, rare earths elements, solvent extraction

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Authors: Mulatu Kassie Birhanu

Abstract:

Electrochemical reduction of CO₂ is an emerging and current issue for its conversion in to valuable product upon minimization of its atmospheric level for contribution of maintaining within the range of permissible limit. Among plenty of electro-catalysts gold and copper are efficient and effective catalysts, which are synthesized and applicable for this research work. The two metal catalysts were prepared in inert environment with different compositions through co-reduction process from their corresponding precursors and then by adding multi-walled carbon nano-tube as a supporter and enhanced the conductivity. The catalytic performance of CO₂ reduction for each composition was performed and resulted an outstanding catalytic activity with generation of high current density (70 mA/cm² at 0.91V vs. RHE) and relatively small onset potential. The catalytic performance, compositions, morphologies, structure and geometric arrangements were evaluated by electrochemical analysis (LSV, impedance, chronoamperometry & tafel plot), EDS, SEM and XAS respectively. The composite metals showed better selectivity of products and faradaic efficiencies due to the synergetic effects of the combined nano-particles in addition to the impact of grain size in reduction of CO₂. Carbon monoxide, hydrogen, formate and ethanol are the reduction products, which are detected and quantifiable by chromatographic techniques considering their physical state of each product.

Keywords: carbondioxide, faradaic efficiency, electrocatalyst, current density

Procedia PDF Downloads 43

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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