Journal articles: 'Effect of chemicals'

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Lalruatfela, B. "A review on tobacco and its effect on health." Science Vision 19, no. 1 (March 31, 2019): 16–23. http://dx.doi.org/10.33493/scivis.19.01.04.

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Tobacco is an important agricultural product that is consumed all over the world. More than 8000 chemicals are reported to be present in tobacco, and a large number of these chemicals are known carcinogens, and hence is known to be one of the most significant contributors to the development of cancer of different body parts. These chemicals have been reported to alter both the genetic and epigenetic constituents of cells. Such changes involve point mutation, deletion, insertion, recombination, transversion, transition, and chromosomal aberrations including aneuploidy and polyploidy. The chemical composition of different types of tobacco has been reported to be different. In this article, brief information about tobacco plants; history, types and popularity of tobacco; its chemical composition; relation to cancer and other diseases and its effects on the molecular, epigenetic and genetic compositions have been highlighted.

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Liang-Yong, Wang, Zhang Kai-Liang, Song Zhi-Tang, and Feng Song-Lin. "Effect of Chemicals on Chemical Mechanical Polishing of Glass Substrates." Chinese Physics Letters 24, no. 1 (January 2007): 259–61. http://dx.doi.org/10.1088/0256-307x/24/1/070.

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Liu, Xian Na, and Shun Sheng Chen. "Study on Defluorination Effect of Antarctic Krill by Chemical Treatments." Advanced Materials Research 941-944 (June 2014): 1151–56. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.1151.

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Decreasing effects of fluoride contents in Antarctic krill (Euphausia superba) as affected by chemical treatments with and without heating were investigated. The used chemicals were Na2SO3, citric acid, acetic acid, HCl, betaine, sodium chloride. Fluoride contents per dry weight were 1138±1 mg/kg in the whole body of krill (WBK) and 333±2 mg/kg in the peeled krill meat (PKM) respectively. When WBK was treated with chemicals with and without heating, Decreasing effects of fluoride contents is not significant. The effect of defluorination by chemical treatments with heating is more significant than without heating. Particularly, the treatment of betaine without heating showed the best reduction effect of 48±9mg/kg and the highest defluorination efficiency of 85.59%, followed by citric acid (52±11mg/kg,84.38%), acetic acid (55±6mg/kg,83.48%) and hydrochloric acid (62±5mg/kg,81.38%).

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Liu, Tao, Lei Chen, and Xiaoyong Pan. "An Integrated Multi-Label Classifier with Chemical-Chemical Interactions for Prediction of Chemical Toxicity Effects." Combinatorial Chemistry & High Throughput Screening 21, no. 6 (August 27, 2018): 403–10. http://dx.doi.org/10.2174/1386207321666180601075428.

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Aims and Objective: Chemical toxicity effect is one of the major reasons for declining candidate drugs. Detecting the toxicity effects of all chemicals can accelerate the procedures of drug discovery. However, it is time-consuming and expensive to identify the toxicity effects of a given chemical through traditional experiments. Designing quick, reliable and non-animal-involved computational methods is an alternative way. Method: In this study, a novel integrated multi-label classifier was proposed. First, based on five types of chemical-chemical interactions retrieved from STITCH, each of which is derived from one aspect of chemicals, five individual classifiers were built. Then, several integrated classifiers were built by integrating some or all individual classifiers. Result and Conclusion: By testing the integrated classifiers on a dataset with chemicals and their toxicity effects in Accelrys Toxicity database and non-toxic chemicals with their performance evaluated by jackknife test, an optimal integrated classifier was selected as the proposed classifier, which provided quite high prediction accuracies and wide applications.

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GOLDEN, D. A., E. K. HEATON, and L. R. BEUCHAT. "Effect of Chemical Treatments on Microbiological, Sensory and Physical Qualities of Individually Shrink-Wrapped Produce." Journal of Food Protection 50, no. 8 (August 1, 1987): 673–80. http://dx.doi.org/10.4315/0362-028x-50.8.673.

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Effects of four chemical treatments on microbiological, sensory and physical qualities of individually shrink-wrapped bell peppers, tomatoes, peaches and cantaloupes stored at 0 to 21°C were determined. With the exception of produce treated with guazatine, higher populations of microorganisms were detected on shrink-wrapped produce than on unwrapped produce as storage time increased. Treatment of wrapped produce with guazatine generally controlled microbial populations at about the same levels or at lower levels than those detected on unwrapped produce treated with imazalil, chlorine and a quaternary ammonium compound. Little inhibition of microbial growth compared to untreated produce was observed on fruits and vegetables treated with the latter three chemicals. None of the chemicals had deleterious effects on sensory or physical qualities of produce, with the exception of imazalil which caused severe brown discoloration on wrapped and unwrapped peaches. Shrink-wrapping retarded loss of firmness of chemically treated and untreated bell peppers, but had little effect on changes in firmness of the other produce during storage.

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Czarnota, Jenna, David C. Wheeler, and Chris Gennings. "Evaluating Geographically Weighted Regression Models for Environmental Chemical Risk Analysis." Cancer Informatics 14s2 (January 2015): CIN.S17296. http://dx.doi.org/10.4137/cin.s17296.

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In the evaluation of cancer risk related to environmental chemical exposures, the effect of many correlated chemicals on disease is often of interest. The relationship between correlated environmental chemicals and health effects is not always constant across a study area, as exposure levels may change spatially due to various environmental factors. Geographically weighted regression (GWR) has been proposed to model spatially varying effects. However, concerns about collinearity effects, including regression coefficient sign reversal (ie, reversal paradox), may limit the applicability of GWR for environmental chemical risk analysis. A penalized version of GWR, the geographically weighted lasso, has been proposed to remediate the collinearity effects in GWR models. Our focus in this study was on assessing through a simulation study the ability of GWR and GWL to correctly identify spatially varying chemical effects for a mixture of correlated chemicals within a study area. Our results showed that GWR suffered from the reversal paradox, while GWL overpenalized the effects for the chemical most strongly related to the outcome.

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Luo, Yan, and Yi Li. "Control quantity or toxicity of textile chemicals? A case study of denim jeans in the warp-dyeing phase." Textile Research Journal 91, no. 15-16 (February 8, 2021): 1900–1906. http://dx.doi.org/10.1177/0040517521993488.

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The extensive use and discharge of chemicals is one of the main factors leading to serious environmental pollution in the textiles and apparel industry. The chemical footprint (ChF) is a toxicity-based chemical management method that is used to quantitatively evaluate the potential toxic effects of chemical pollutants discharged during the production of textiles and apparel products on human health and environmental safety. Compared with the traditional quantity-based method, this method needs to simulate the entire process of chemicals from discharge to impact, involving a series of steps of fate, exposure and effect, which greatly increases the difficulty of modeling. A scientific question is whether it is worth spending so much effort to quantify the toxicity of chemicals. Taking the warp-dyeing phase of denim jeans as an example, this paper calculated the ChFs for both human and ecological toxicities of textile chemicals based on the USEtox model, and compared them with the values of discharge quantities. The results reveal that there is a certain inconsistency between the discharge quantity and toxicity of chemical substances. Relying solely on the amount of chemicals discharged can sometimes lead to misjudgments, emphasizing the importance of controlling the toxicity of chemicals.

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Ogungbemi, Afolarin O., Riccardo Massei, Rolf Altenburger, Stefan Scholz, and Eberhard Küster. "Assessing Combined Effects for Mixtures of Similar and Dissimilar Acting Neuroactive Substances on Zebrafish Embryo Movement." Toxics 9, no. 5 (May 6, 2021): 104. http://dx.doi.org/10.3390/toxics9050104.

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Risk assessment of chemicals is usually conducted for individual chemicals whereas mixtures of chemicals occur in the environment. Considering that neuroactive chemicals are a group of contaminants that dominate the environment, it is then imperative to understand the combined effects of mixtures. The commonly used models to predict mixture effects, namely concentration addition (CA) and independent action (IA), are thought to be suitable for mixtures of similarly or dissimilarly acting components, respectively. For mixture toxicity prediction, one important challenge is to clarify whether to group neuroactive substances based on similar mechanisms of action, e.g., same molecular target or rather similar toxicological response, e.g., hyper- or hypoactivity (effect direction). We addressed this by using the spontaneous tail coiling (STC) of zebrafish embryos, which represents the earliest observable motor activity in the developing neural network, as a model to elucidate the link between the mechanism of action and toxicological response. Our objective was to answer the following two questions: (1) Can the mixture models CA or IA be used to predict combined effects for neuroactive chemical mixtures when the components share a similar mode of action (i.e., hyper- or hypoactivity) but show different mechanism of action? (2) Will a mixture of chemicals where the components show opposing effect directions result in an antagonistic combined effect? Results indicate that mixture toxicity of chemicals such as propafenone and abamectin as well as chlorpyrifos and hexaconazole that are known to show different mechanisms of action but similar effect directions were predictable using CA and IA models. This could be interpreted with the convergence of effects on the neural level leading to either a collective activation or inhibition of synapses. We also found antagonistic effects for mixtures containing substances with opposing effect direction. Finally, we discuss how the STC may be used to amend risk assessment.

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DEVLIEGHERE, F., K. FRANCOIS, K. M. VEREECKEN, A. H. GEERAERD, J. F. VAN IMPE, and J. DEBEVERE. "Effect of Chemicals on the Microbial Evolution in Foods." Journal of Food Protection 67, no. 9 (September 1, 2004): 1977–90. http://dx.doi.org/10.4315/0362-028x-67.9.1977.

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In contrast with most chemical hazardous compounds, the concentration of food pathogens changes during processing, storage, and meal preparation, making it difficult to estimate the number of microorganisms or the concentration of their toxins at the moment of ingestion by the consumer. These changes are attributed to microbial proliferation, survival, and/or inactivation and must be considered when exposure to a microbial hazard is assessed. The number of microorganisms can also change as a result of physical removal, mixing of food ingredients, partitioning of a food product, or cross-contamination (M. J. Nauta. 2002. Int. J. Food Microbiol. 73:297–304). Predictive microbiology, i.e., relating these microbial evolutionary patterns to environmental conditions, can therefore be considered a useful tool for microbial risk assessment, especially in the exposure assessment step. During the early development of the field (late 1980s and early 1990s), almost all research was focused on the modeling of microbial growth over time and the influence of temperature on this growth. Later, modeling of the influence of other intrinsic and extrinsic parameters garnered attention. Recently, more attention has been given to modeling of the effects of chemicals on microbial inactivation and survival. This article is an overview of different applied strategies for modeling the effect of chemical compounds on microbial populations. Various approaches for modeling chemical growth inhibition, the growth–no growth interface, and microbial inactivation by chemicals are reviewed.

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Sarlin, T., S. Halttunen, P. Vuoriranta, and J. Puhakka. "Effects of Chemical Spills on Activated Sludge Treatment Performance in Pulp and Paper Mills." Water Science and Technology 40, no. 11-12 (December 1, 1999): 319–25. http://dx.doi.org/10.2166/wst.1999.0728.

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The aim of this research was to study the effects of chemical spills on activated sludge metabolic activity and settleability. On-site, laboratory-scale tests were carried out at three pulp and paper mill activated sludge plants. Oxygen uptake rate (OUR) and dissolved organic carbon (DOC) removal were used for monitoring of metabolic inhibition. The effects of chemicals on 30-min settled sludge volume were studied. Accidental release reports from five pulp and paper mills were analysed. Thirty-four chemicals were selected to the laboratory tests. Of the tested chemicals 2 biocides, monochloro acetic acid, soft soap and turpentine inhibited the OUR of the sludge and thus, had an acute toxic effect on the activated sludge. The biocides and disperging agent reduced DOC removal. Aluminium sulphate and optical brightener had a negative effect on sludge settleability and thus, they may cause losses of activated sludge from treatment plant. In conclusion, maximum possible spill of the five chemicals may reduce the performance of the activated sludge.

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AlSofi, Abdulkareem M., Ali M. AlKhatib, Hassan A. Al-Ajwad, Qiwei Wang, and Badr H. Zahrani. "Assessment of Enhanced-Oil-Recovery-Chemicals Production and its Potential Effect on Upstream Facilities." SPE Journal 24, no. 03 (January 17, 2019): 1037–56. http://dx.doi.org/10.2118/183159-pa.

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Summary Review of past chemical-enhanced-oil-recovery (EOR) projects illustrates that chemical-EOR implementation can result in produced-fluid-handling issues. However, in all projects such issues were resolved, mainly through a combination of improved demulsifiers and oversized vessels. In previous work, we have demonstrated the potential of surfactant/polymer flooding for a high-temperature/high-salinity carbonate. In consideration of future plans to pilot the process, further assessments were conducted to evaluate any side effects of these EOR chemicals on upstream facilities and determine mitigation plans if needed. In this work, we initially conduct a critical review of past experience. Then, we investigate the surfactant/polymer compatibility with the additives used in processing facilities for demulsification and scale and corrosion inhibition as well as the possible effect of surfactant/polymer on oil/water separation, metal corrosion, and scale inhibition. For this purpose, we first perform a sensitivity-based simulation study to estimate the volumes of produced EOR chemicals. Second, a compatibility study is conducted to evaluate EOR chemical compatibility with oilfield additives (i.e., demulsifier, corrosion inhibitor, and scale inhibitor). Third, bottle tests are conducted using surfactant/polymer solutions prepared in both injection and produced water to evaluate the effect of EOR chemicals on oil/water separation. Separated-water qualities are also evaluated using solvent extraction followed by ultraviolet (UV) visibility testing. Fourth, static autoclave and dynamic rotating tests are performed to evaluate the possible side effects of EOR chemicals on corrosion inhibition. Finally, static bottle and dynamic tube tests are performed to evaluate the possible side effects of EOR chemicals on scale inhibition; these observations are supported by characterization of precipitates using environmental scanning electron microscopy (ESEM) and X-ray diffraction (XRD). Depending on simulation, the peak polymer and surfactant concentrations at the separation plant are 83 and 40 ppm, respectively. The sensitivity study suggests a worst-case scenario in which peak polymer and surfactant concentrations of 174 and 128 ppm are produced. Compatibility testing confirms the compatibility of EOR chemicals with the additives used in upstream facilities. In those tests, neither precipitation nor phase separation is observed. Bottle tests indicate an overall negligible effect on oil/water-separation speed. However, analyses of separated-water quality indicated a noteworthy deterioration in separated-water qualities. Oil-in-water concentrations increase from 100 to 750 ppm and from 300 to 450 ppm at injection- and produced-water salinities, respectively. Furthermore, corrosion tests suggest that surfactant/polymer presence results in a significant reduction in corrosion rates by 70 and 86% at static and dynamic conditions, respectively, without any pitting issues. Finally, static and dynamic scale-inhibition studies performed at exacerbated conditions suggest that EOR chemicals can reduce the effectiveness of scale inhibitors. In static scaling tests, the effectiveness of the base polyacrylate inhibitor diminishes completely. However, the same degree of inhibition was achieved by switching to phosphonate inhibitors, but at a slightly higher dosage between 5 and 15 mg/L. In dynamic scaling tests, the base polyacrylate inhibitor failed at all tested dosages up to 100 mg/L. However, the alternative phosphonate inhibitors passed at dosages between 20 and 45 mg/L. Such effects can be attributed to changes in scale morphology and polymorphs, as demonstrated by the XRD and ESEM results. On the basis of those results, we conclude that the selected surfactant/polymer implementation will have a manageable effect on separation facilities. Finally, this work provides an experimental protocol to evaluate the potential side effects of a chemical-EOR process on upstream facilities.

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Tribulová, Tereza, František Kačík, Dmitry V. Evtuguin, and Iveta Čabalová. "Influence of Chemical Treatment on Chemical Changes of Fir Wood." Key Engineering Materials 688 (April 2016): 38–43. http://dx.doi.org/10.4028/www.scientific.net/kem.688.38.

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Many chemicals are used to prolong wood lifetime and protect wood against wood-destroying organisms and fire but there is not sufficient information about their possible corrosive effects on wood and its structural components from the perspective of long-term exposition in unsuitable condition. This study evaluated the combined effects of inorganic chemicals (borates, phosphates containing ammonia, sulphates with metal cations, chlorides) and wet-thermal accelerated ageing (T=80 °C, RH=65 %, for 30 days) on chemical composition of treated wood. Used analyses indicated that selected chemicals cause a decomposition of all wood constituents in varying degrees. Cellulose was degraded in the greatest extent due to acidic sulphates (Fe3+, Cu2+) and almost no deterioration of polysaccharides was caused with H3BO3. A negative effect on lignin had almost only Na2B4O7.10H2O and NaCl. At the same time the amount of extractives in hot water and acetone and ash content were compared at all samples. The wet-thermal ageing played an important role in wood degradation, but the effect of chemical treatment was certainly stronger.

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Uddin, MS, MM Rahman, MZ Alam, MM Hossain, and ME Hoque. "Effect of farmers' practices for the management of insect pests of yard long bean (Vigna unguiculata)." Bangladesh Journal of Agricultural Research 39, no. 1 (August 25, 2014): 173–84. http://dx.doi.org/10.3329/bjar.v39i1.20167.

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The research activity was conducted in major intensive yard long bean growing areas, such as Jessore, Dhaka, Narsingdi, Comilla, and Chittagong of Bangladesh to know farmers practices (FPs) for managing major insect pests of yard long bean during March 2009 to October 2009 in the farmers fields. The study comprised survey of sample farmers through intensive field visit for field data collection and inspection. A total of 5 farmers practices (FPs) were identified viz., Farmers Practice 1 (FP1) comprised chemicals plus mechanical plus cultural plus field sanitation, FP2 comprised chemicals plus cultural plus field sanitation, FP3 consisted of combination of chemicals plus field sanitation, FP4 having combination of mechanical plus cultural plus field sanitation and FP5 utilized combination of cultural plus field sanitation. Among the sample farmers, 81.33% practiced chemicals plus non-chemical methods, while 18.67% practiced only non-chemical methods. Considering infestation level, pod yield, BCR, and arthropod pests diversity, the performance of FP1 (chemical + mechanical + cultural + field sanitation methods) was adjudged as the best for managing pod borer and aphid and was revealed as the most suitable option (94.10% infestation reduction) for managing major insect pests of yard long bean in those areas of Bangladesh. DOI: http://dx.doi.org/10.3329/bjar.v39i1.20167 Bangladesh J. Agril. Res. 39(1): 173-184, March 2014

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Espin, N., and M. N. Islam. "Stabilization of papain from papaya peels / Estabilización de la papaína de la cáscara de papaya." Food Science and Technology International 4, no. 3 (June 1998): 179–87. http://dx.doi.org/10.1177/108201329800400304.

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Crude papain in papaya peels was stabilized before drying by the addition of various chemicals (ascorbic acid, sodium ascorbate, erythorbic acid, sodium erythorbate, sodium metabisulfite, sodium tetrathionate, 4-hexylresorcinol, t-butyl hydroquinone [TBHQ], rutin, α-tocopherol, trehalose, and sucrose). Chemicals were added to the ground papaya peels at 0, 0.12, 0.25, 0.5, 0.75, 1, 1.25, and 1.5% (w /w). Drying temperatures were 40, 55 and 60 °C. Enzyme activity was measured before and after drying by the casein digestion method. Percentage of enzyme activity retained (% EAR) was calculated by assigning a value of 100% EAR to fresh peels. Possible synergism between chemicals was also studied for a 1:1 ratio chemical/chemical at 1% total concentration. The highest % EAR was obtained at 55 °C for all chemicals except for sucrose and trehalose which showed their best effect at 40 °C. TBHQ rutin, α-tocopherol and 4-hexylresorcinol showed a destabilizing effect. Maximum protective effect occurred at 1% concentration. At this concentration sodium tetrathionate showed the best protective effect (90% EAR) followed by sodium metabisulfite (85% EAR), while both sodium ascorbate and sodium erythorbate retained 75% of the original activity. Ascorbic acid and erythorbic acid were 10% less effective than their corresponding sodium salts, possibly due to lower pH. Trehalose showed only 57 % EAR while sucrose failed to produce any appreciable effect. No synergistic effect was shown by any combination of chemicals.

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Hartoft-Nielsen, Marie-Louise, Malene Boas, Sofie Bliddal, Åase Krogh Rasmussen, Katharina Main, and Ulla Feldt-Rasmussen. "Do Thyroid Disrupting Chemicals Influence Foetal Development during Pregnancy?" Journal of Thyroid Research 2011 (2011): 1–14. http://dx.doi.org/10.4061/2011/342189.

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Maternal euthyroidism during pregnancy is crucial for normal development and, in particular, neurodevelopment of the foetus. Up to 3.5 percent of pregnant women suffer from hypothyroidism. Industrial use of various chemicals—endocrine disrupting chemicals (EDCs)—has been shown to cause almost constant exposure of humans with possible harmful influence on health and hormone regulation. EDCs may affect thyroid hormone homeostasis by different mechanisms, and though the effect of each chemical seems scarce, the added effects may cause inappropriate consequences on, for example, foetal neurodevelopment. This paper focuses on thyroid hormone influence on foetal development in relation to the chemicals suspected of thyroid disrupting properties with possible interactions with maternal thyroid homeostasis. Knowledge of the effects is expected to impact the general debate on the use of these chemicals. However, more studies are needed to elucidate the issue, since human studies are scarce.

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Zinke, Stephan, Ingrid Gerner, Gabriele Graetschel, and Eva Schlede. "Local Irritation/Corrosion Testing Strategies: Development of a Decision Support System for the Introduction of Alternative Methods." Alternatives to Laboratory Animals 28, no. 1 (January 2000): 29–40. http://dx.doi.org/10.1177/026119290002800108.

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The notification procedure for new chemicals of the European Union (EU) requires protocols on physicochemical and toxicological tests for the evaluation of physico-chemical properties and probable toxic effects of each notified substance. In order to reduce the amount of animal testing, alternative methods should be introduced into toxicity testing. Therefore, we have developed a rule-based decision support system (DSS) for the prediction of the local corrosive/irritant properties of new chemicals. To this end, data on more than 1000 substances were examined, which resulted in approximtely 180 “exception-rules” of the kind IF (physicochemical property) A THEN not (toxic) Effect B. In addition, the structural formulae of the chemicals were analysed, which resulted in approximately 160 “structure-rules” of the kind IF Substructure A THEN Effect B. The DSS can predict (based on theoretical structure-activity relationships) whether a chemical produces: a) corrosive effects (i.e. no testing is necessary; b) might have corrosive effects (i.e. no animal testing, in vitro tests are suitable); and c) will produce no effects or only marginal effects (i.e. animal tests are necessary based on current EU legislation for hazard assessment purposes). In addition, the DSS provides reliable data for legal classification and labelling based on a specific result.

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Kim, Hyoung-Gyun, Yoo-Min An, Doo-Kyung Moon, and Jin-Goo Park. "Effect of Chemicals and Slurry Particles on Chemical Mechamical Polishing of Polyimide." Japanese Journal of Applied Physics 39, Part 1, No. 3A (March 15, 2000): 1085–90. http://dx.doi.org/10.1143/jjap.39.1085.

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Manong’a, Theresa, and Adesh Kumar. "Effect of Growth Promoting and Resistance Inducing Chemicals on Yield Attributing Characteristics of Tomato." Journal of Pure and Applied Microbiology 11, no. 3 (September 30, 2017): 1479–85. http://dx.doi.org/10.22207/jpam.11.3.32.

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Behar, Alberto. "Ototoxicity and Noise." Journal of Otorhinolaryngology, Hearing and Balance Medicine 1, no. 2 (December 12, 2018): 10. http://dx.doi.org/10.3390/ohbm1020010.

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In most cases, hearing loss is the result of exposure to high levels of noise for extended periods of time or as an effect of aging. Although this is found in most situations, hearing can also be damaged by certain chemical agents in pure state, or as a combination. These chemicals can even include parts of drugs used for the treatment of illnesses for which there are no other remedies. Ototoxic chemicals are also found in the workplace, in most occasions as solvents. The effects from these elements are worst when combined with exposure to a high level of noise. This paper examines the effects of these chemicals in isolation or in combination with noise and gives recommendations on how to deal with this problem.

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Shahinur, Sweety, Mahbub Hasan, Qumrul Ahsan, Nayer Sultana, Zakaria Ahmed, and Julfikar Haider. "Effect of Rot-, Fire-, and Water-Retardant Treatments on Jute Fiber and Their Associated Thermoplastic Composites: A Study by FTIR." Polymers 13, no. 15 (August 1, 2021): 2571. http://dx.doi.org/10.3390/polym13152571.

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Natural renewable materials can play a big role in reducing the consumption of synthetic materials for environmental sustainability. Natural fiber-reinforced composites have attracted significant research and commercial importance due to their versatile characteristics and multi-dimensional applications. As the natural materials are easily rotten, flammable, and moisture absorbent, they require additional chemical modification for use in sustainable product development. In the present research, jute fibers were treated with rot-, fire-, and water-retardant chemicals and their corresponding polymer composites were fabricated using a compression molding technique. To identify the effects of the chemical treatments on the jute fiber and their polymeric composites, a Fourier transformed infrared radiation (FTIR) study was conducted and the results were analyzed. The presence of various chemicals in the post-treated fibers and the associated composites were identified through the FTIR analysis. The varying weight percentage of the chemicals used for treating the fibers affected the physio-mechanical properties of the fiber as well as their composites. From the FTIR analysis, it was concluded that crystallinity increased with the chemical concentration of the treatment which could be contributed to the improvement in their mechanical performance. This study provides valuable information for both academia and industry on the effect of various chemical treatments of the jute fiber for improved product development.

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WORTHY, WARD. "U.S. DROUGHT: Little effect on ag chemicals." Chemical & Engineering News 66, no. 27 (July 4, 1988): 4. http://dx.doi.org/10.1021/cen-v066n027.p004.

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Sutarman, Encu, Widjajani, and Estiyan Dwipriyoko. "Effect of Additive Chemicals on Soil Characteristics." Journal of Physics: Conference Series 1477 (March 2020): 052036. http://dx.doi.org/10.1088/1742-6596/1477/5/052036.

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Brown, Halina Szejnwald, Carol Rowan West, Donna R. Bishop, and Labelle R. Hicks. "A Methodology for Assessing Developmental and Reproductive Hazards of Chemicals." Toxicology and Industrial Health 2, no. 3 (July 1986): 183–203. http://dx.doi.org/10.1177/074823378600200302.

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A method to evaluate developmental and reproductive toxicity for a wide variety of chemicals has been developed. The assessment includes all effects on male and female reproductive function as well as effects in the developing embryo or fetus. Effects are evalu ated using primary literature. Studies are classified as adequate, supportive or inadequate. Only adequate studies are used in further assessment. Reproductive and developmental toxicity of each chemical is assessed using both qualitative and quantitative infor mation. Three elements are used to describe developmental toxicity of chemicals: Lowest Observed Effect Level (LOEL), weight-of- evidence classification and a Risk Ratio (RR). For reproductive toxicity only two elements are used, LOEL and weight-of-evidence. LOEL is defined as the lowest dose at which statistically significant effects are found. A risk ratio is calculated using the levels of the chemical producing acute maternal lethalilty (LD50 or LC5o) to the levels producing developmental toxicity in the same animal species and route of administration. The risk ratio is used to indicate the extent to which the developing embryo or fetus is more susceptible than the dam to the toxic effects of a chemical. A toxicity score (A

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Tillitt, D. E., and D. M. Papoulias. "Closing the gap between exposure and effects in monitoring studies." Pure and Applied Chemistry 75, no. 11-12 (January 1, 2003): 2467–75. http://dx.doi.org/10.1351/pac200375112467.

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A major challenge to contaminant monitoring programs is the selection of an appropriate suite of measurements for assessing exposure and effects. Early monitoring programs relied solely on residue analysis to detect the organochlorine compounds that were in use at that time. A shift to the use of more transient, less persistent chemicals required that a new set of tools be developed to determine if an organism had been exposed. This led to the development of cellular and biochemical assays that could indicate the presence of these types of chemicals in biota and the environment. However, it was recognized that measures of contaminant presence alone were insufficient to assess the health of biota. As a result, considerable research began to be directed toward development of diagnostic tools for measuring chemical effects in fish and wildlife. Today, contaminant monitoring programs follow a paradigm for study design that emphasizes not only the use of measures of exposure, but also measures of effect. Using data from our monitoring and research studies for hormonally active substances, we discuss a variety of metrics of exposure and effects and their application to specific chemicals, and the current information gaps. We conclude that although several bioindicators of exposure and effect have been promoted and used, to date there continues to be a poor association between cause and effect for endocrine active substances. In part, this is due to the limited number of diagnostic tools that are available and to a lack of basic toxicological information concerning toxicokinetics and mechanisms of action of hormonally active chemicals in fish and wildlife species. In the foreseeable future, both tissue and environmental residue data, despite the many limitations, will continue to be an important component of monitoring programs for hormonally active chemicals as we continue to develop and validate more specific bioindicators of exposure and effects.

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Miyamoto, J. "Environmental and Health Issues." Pure and Applied Chemistry 68, no. 9 (September 30, 1996): 1737–48. http://dx.doi.org/10.1351/pac199668091737.

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The environmental behavior of a chemical is governed by its intrinsic physicochemical properties, including their metabolic activities, as well as by characteristic features of the environmental compartments. This inextricable network of interactions contribute to degradation and mineralization of organic compounds. Under the circumstances that the chemical is lipophilic and/or resistant against chemical and biological degradation, it tends to be transported to other environmental compartments and/or subject to bioaccumulation. The adverse effects of chemicals on humans and organisms in the environment are assessed by a variety of toxicological studies to establish ADI (acceptable daily intake in man) or PNEC (predicted no observed effect level in organisms), in comparison with the calculated exposure levels based on the environmental behavior of chemicals.

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Hasan, Md Tawhid, Gias Uddin Ahmed, Md Mamunur Rahman, and Mohammad Nurul Alam. "Study on the effect of aquaculture-drugs and chemicals on health and production of prawn (Macrobrachium rosenbergii) in Narail, Bangladesh." Asian Journal of Medical and Biological Research 1, no. 1 (November 4, 2015): 89–94. http://dx.doi.org/10.3329/ajmbr.v1i1.25503.

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The present study was carried out to evaluate the effect of aquaculture-drugs and chemicals on health and production of prawn in Narail district. Data were collected through questionnaire interview, market survey and focus group discussion from June to December 2014. Six categories and 28 types of chemicals were found in the chemical shops as well as used by the farmers. Chemicals used in pond preparation, equipments disinfection, oxygen supplementation, growth promotion, antibiotics and disease treatment. Eco-solution, malachite green and melathion were used in the treatment of viral diseases having 85%, 70% and 65% recovery respectively. Potassium permanganate, oxytetracycline and renamycine had 86%, 80% and 75% recovery respectively against protozoan and bacterial diseases. Clinically prawn appeared normal greenish in control ponds, whereas, in chemical treated prawn appeared yellowish brown and grayish color. Histology of muscle of control prawn were almost normal except some vacuums, however, chemical treated prawn muscle had remarkable pathological changes like necrosis, vacuums and pyknotic cells. Prawn production was 85 kg/acre in control ponds, 150 kg/ acre in lime-urea treated ponds and 450 kg/ acre in chemical treated ponds.Asian J. Med. Biol. Res. June 2015, 1(1): 89-94

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Jones, Troyce D., Phil J. Walsh, and Elaine A. Zeighami. "Permissible Concentrations of Chemicals in Air and Water Derived From Rtecs Entries: a "Rash" Chemical Scoring System." Toxicology and Industrial Health 1, no. 4 (October 1985): 213–34. http://dx.doi.org/10.1177/074823378500100414.

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Many chemicals are of concern to human health, but only a few have epidemiologically derived risk estimates. About 45,000 chemicals are listed in RTECS, most of which have had some testing in subhuman models. RTECS entries range from cellular effects through organoleptic damage to lethality, with many pathological endpoints listed, including mutagenic changes, irritation, teratogenesis, cancer, mortality, etc. However, it is difficult to extend any biological test results to human risk assessments. If the results are extended, the degree of validity is highly uncertain. This paper describes a logical basis for using the entire complex spectrum of test results to evaluate the overall toxicological potency of a chemical to be assayed ( i.e., an interviewing chemical) and describes how to derive tentative, permissible concentrations in air and water for any particular chemical for which no regulatory guidance exists. This approach has been tested for 16 reference chemicals discussed in NIOSH Criteria Documents, EPA-CAG reports, etc. The evaluations are uncomplicated, but occasionally it is difficult to match RTECS entries for two different chemicals. Difficult compar isons may require some familiarity with experimental design and the toxicological literature. One important product of this novel approach is that a distribution or array of potency values is obtained for any chemical evaluated. This distribution reflects many uncertainties stemming from low statistical power, experimental design, pharmacological processes, interspecies variability, dose rate, biological effect monitored, route of treatment, etc. The array of relative values for a particular chemical reflects many different biological and physical conditions. The distribution of the array helps to index a composite toxicological profile for many different biological effects resulting from numerous treatment protocols. To minimize the effect of extreme sensitivity of certain (perhaps novel) biological test models, possible errors in the RTECS database, and possible human pharmacological insensitivity to a particular chemical and/or a particular route of administration, we consider the interquartile range (i.e., the central 50%) of the array of relative potency values between two chemicals being compared as a practical measure of uncertainty. Thus, the range in response derived from variability in relative potency should be useful in addressing the range of response in man as estimated from extrapolations of test data.

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Jou, C. Jerry, Jay P. Farber, Chao Qin, and Robert D. Foreman. "Afferent pathways for cardiac-somatic motor reflexes in rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 281, no. 6 (December 1, 2001): R2096—R2102. http://dx.doi.org/10.1152/ajpregu.2001.281.6.r2096.

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The present study used a rat model in which algogenic chemicals were infused into the pericardial sac to evoke spasmlike contractions in paraspinal muscles. The following techniques were used to study the roles of sympathetic (SCA) and vagal cardiac afferents (VCA) in electromyographic (EMG) responses to pericardial algogenic chemicals: chemical stimulation, electrical stimulation, and nerve transection. Activation with bradykinin ( n = 46) produced a significantly higher peak response than infusion of an algogenic mixture ( n = 53) containing chemicals that also activate VCA. Electrical stimulation of SCA produced bilateral EMG activities (7 of 7). Electrical stimulation of VCA did not evoke EMG activity but inhibited the chemically evoked EMG response (12 of 12). The chemically evoked response was decreased after transection of the left sympathetic chain ( n = 22) and was increased after bilateral vagotomy ( n = 19). These results suggest an excitatory and inhibitory role for SCA and VCA, respectively. Therefore, in addition to spinothalamic convergence of somatic and visceral afferents, activation of SCA to generate spasmlike muscle contractions could account in part for anginal pain, and VCA activation could attenuate this effect.

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Rao, Addanki Sambasiva, Medha A. Dharap, and J. V. L. Venkatesh. "Experimental Study of the Effect of Post Processing Techniques on Mechanical Properties of Fused Deposition Modelled Parts." International Journal of Manufacturing, Materials, and Mechanical Engineering 5, no. 1 (January 2015): 1–20. http://dx.doi.org/10.4018/ijmmme.2015010101.

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FDM (Fused Deposition Modelled) parts are chemically treated with two types of chemicals viz Dimethyl ketone (Acetone) and Methyl ethyl ketone to reduce the surface roughness. This chemical treatment method technique not only reduces surface roughness but also makes effect on strength of chemically treated parts of ABS (Acrylonitrile Butadiene Styrene) material. In this study Taguchi method of DOE (Design of Experiments) is conducted on test specimen of “tensile”, “bending” and “izod impact” components which are manufactured through Fused Deposition Modeling process using ABS-P400 material. DOE is conducted to optimize the effect of chemical treatment process parameters on strength of above specimen parts. The process parameters considered for the DOE are “different levels of concentration of chemical, temperature, time, layer thickness etc. ANOVA (Analysis of variance) is used to know the significance of contribution of each of these parameters. Results reveal that the prototypes when treated at optimum condition the tensile strength, flexural strength and izod impact strength improved significantly.

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Todorov, Milen. "Recent advances in computational chemistry for identification of ligands for biological receptors: interdisciplinary aspects." Medical Science Pulse 12, no. 1 (March 31, 2018): 12–15. http://dx.doi.org/10.5604/01.3001.0011.6670.

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Background: Computational (in silico) methods, such as quantitative structure-activity relationships (QSARs) are already well recognized and used in many screening programs related to environmental, industrial and medical chemistry. The main idea of the QSAR is that there is a relationship between molecular structure and ultimate biological effect caused by a chemical compound. In this respect the approach could be used successfully for prediction of various biological endpoints caused by chemical compounds including receptor binding affinity. Aim of the study: In the current study the capabilities for structure-activity modelling incorporated in noncommercial software tool have been employed for investigating the binding effect of xenobiotics toward estrogen and human pregnane X receptor. Material and methods: The analysis was performed by making use of the non-commercial software platform QSAR Toolbox. This system allows application of a set of built-in models for different biological effects, and also allows incorporation of new models for other endpoints. Results: Two models have been applied for predicting the binding effect toward estrogen and human pregnane X receptors of a large number of chemicals collected in a single database of high practical concern. The results show that there are many chemicals which are able to bind the investigated receptors. Since those chemicals are encountered in the environment, they could be considered as potential threat for society. Conclusions: The obtained results could be used as initial step for further experimental testing of those chemicals in order to confirm their potential to harm biological systems in the body.

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Mori, Masukuni. "Effect of Various Chemical Treatments on Handling of Wool Fabric." Key Engineering Materials 671 (November 2015): 3–8. http://dx.doi.org/10.4028/www.scientific.net/kem.671.3.

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It is well known that fabric handle is controllable by controlling and adjusting mechanical properties of the fabric. The handling of fabrics, on one hand, is mostly decided by the structure of the fabric, i.e. quality of yarn, yarn count, twist number, density of warp and weft, fabric weight and weave design. Such a fabric structure is represented in terms of Cover Factor. On the other hand, the handling of fabrics can also be changed through the mechanical properties by dyeing and finishing processes after weaving. The present work investigated how much influence is exerted on wool fabric by 11 sorts of chemicals generally used in dyeing and finishing processes, and how much change is exerted on the handle of processed fabrics. The experimental results were compared with the original fabric with no treatment in terms of mechanical properties relevant to KES. It was confirmed that the fabric handle greatly depended on fabric structure. Besides, the differences in the degree of damage and the hydrophilicity of wool fiber arisen from the treatments using chemicals were examined. The effect of chemicals used in dyeing and finishing processes was also investigated on the environment. Keywords: Wool, Chemical treatment, Fabric handle, KES, Environment.

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Hou, Jun Jie, Jia Chuan Chen, Zhi Qiang Pang, and Gui Hua Yang. "The Chemical Swelling Effect on Poplar APMP." Advanced Materials Research 887-888 (February 2014): 529–32. http://dx.doi.org/10.4028/www.scientific.net/amr.887-888.529.

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Do the research of acidic zinc chloride treatment system to achieve poplar APMP with chemical swelling. The research showed that acidic zinc chloride can effectively swelling poplar APMP pulp, increase the fiber volume and loose the structure, acting concentrated in the amorphous region of the fiber which can help the penetration of chemicals and products of the dissolution. Because the differences of processing system pH and ionic effect, acidic zinc chloride combined alkaline hydrogen peroxide treatment can produce swelling synergistic effect.

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Yoshida, Yukifumi, Hiroaki Takahashi, Masanobu Sato, Jim Snow, Farid Sebaai, and Frank Holsteyns. "The Effect of Rinsing a Germanium Surface after Wet Chemical Treatment." Solid State Phenomena 255 (September 2016): 22–26. http://dx.doi.org/10.4028/www.scientific.net/ssp.255.22.

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The impact of rinsing liquid for Germanium surface after wet chemical treatment is described. The different Ge loss after processing with different rinse (UPW and CO2 water) were determined and the different surface morphologies on the Ge surface after processing with different chemicals (AOM, HF and HCl) were determined by XPS. It was found that the investigation of surface morphology after chemical treatment is necessary to understand the rinse effect and the results showed the CO2 water rinse can decrease and suppress Ge loss at chemical treatment

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Stalmans, M., E. Matthijs, and N. T. de Oude. "Fate and Effect of Detergent Chemicals in the Marine and Estuarine Environment." Water Science and Technology 24, no. 10 (November 1, 1991): 115–26. http://dx.doi.org/10.2166/wst.1991.0282.

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Detergents are high-volume consumer products which are discharged directly into domestic sewage after their use. They are removed in the treatment of domestic sewage and via instream removal mechanisms in surface waters. Important removal mechanisms are biological degradation, adsorption to sediments, etc. The degree of removal mainly depends on the physico-chemical and environmental properties of the chemical and on the type of sewage treatment. The continuous removal processes, combined with the continuous discharge to surface waters via treated or untreated sewage effluents, results in the presence of detergent chemicals in surface waters, where they can further biodegrade. Detergent chemicals can thus, ultimately, enter the marine environment. Data are presented on the discharged amounts of detergent ingredients, such as surfactants and phosphates, to surface waters and to the North Sea. Furthermore, the fate and effects of a typical surfactant in the marine and estuarine environment are described. Monitoring data for one of the major anionic surfactants, Linear Alkylbenzene Sulphonate (LAS), are presented. A comparison of the measured concentrations of LAS with the concentrations, predicted on the basis of a measured dilution of the river water with sea water, shows that this surfactant continues to biodegrade under marine conditions.

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Majerová, Jana, Jakub Hodul, Rostislav Drochytka, and Šárka Keprdová. "Evaluation of Aggressive Chemicals Effect on CIPP Liners." Key Engineering Materials 868 (October 2020): 92–97. http://dx.doi.org/10.4028/www.scientific.net/kem.868.92.

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CIPP renovation methods are often used for renovation of sewers and water mains. They can also be used for renovation of gas and product pipelines. However, the presence of chemicals in these pipelines cannot be excluded. For this reason, the ability of CIPP liners to resist chemicals should be examined. This paper deals with problematics of influence of chemicals (acids and bases) on CIPP liners. Visual changes can be observed using an optical microscope. Structural changes are evident from the results of short-term bending tests.

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Li, Jin Ling, Bao Hui Wang, and Ji Dong Yan. "A Study on Compatibility of an ASP Demulsifier with Defoaming Agent." Advanced Materials Research 524-527 (May 2012): 1780–83. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.1780.

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During the Process of ASP Produced Fluid Treatment, a Considerable Amount of Chemical Agents Were Injected to the Production System due to Problems such as Heavy Emulsion, Scaling and Foaming, Etc. these Chemicals React on each other and Finally Coexist in the Produced Fluid. how about Compatibility between the Chemicals? Will they Strengthen or Weaken their Functions on each other? this Paper Has Confirmed the Effects and their Influences to the Produced Fluid through Lab Tests on Compatibility between Demulsifiers, Defoaming Agents and Proposed a Proper Concentration to Eliminate Influences Caused by the Uncompatibility. Therefore, it Reduces the Effect on the Water Quality.

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Tik, Sovanna, and Peter A. Vanrolleghem. "Chemically enhancing primary clarifiers: model-based development of a dosing controller and full-scale implementation." Water Science and Technology 75, no. 5 (December 23, 2016): 1185–93. http://dx.doi.org/10.2166/wst.2016.600.

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Chemically enhanced primary treatment (CEPT) can be used to mitigate the adverse effect of wet weather flow on wastewater treatment processes. In particular, it can reduce the particulate pollution load to subsequent secondary unit processes, such as biofiltration, which may suffer from clogging by an overload of particulate matter. In this paper, a simple primary clarifier model able to take into account the effect of the addition of chemicals on particle settling is presented. Control strategies that optimize the treatment process by chemical addition were designed and tested by running simulations with this CEPT model. The most adequate control strategy in terms of treatment performance, chemicals saving, and maintenance effort was selected. Full-scale implementation of the controller was performed during the autumn of 2015, and the results obtained confirmed the behaviour of the controlled system. Practical issues related to the implementation are presented.

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Sharma, Mukta, Anupama Rajput, Chhaya Rathod, and Shobharam Sahu. "Food Chemicals Induces Toxic Effect on Health: Overview." UK Journal of Pharmaceutical Biosciences 6, no. 4 (April 1, 2018): 33. http://dx.doi.org/10.20510/ukjpb/6/i4/177335.

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Sen, Purabi. "Effect of Chemicals on Engineering Properties of Soil." International Journal for Research in Applied Science and Engineering Technology V, no. X (October 30, 2017): 1677–85. http://dx.doi.org/10.22214/ijraset.2017.10244.

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Ali, F. S., and A. A. Abdel-Moneim. "Effect of chemicals on fungal α-amylase activity." Zentralblatt für Mikrobiologie 144, no. 8 (1989): 623–28. http://dx.doi.org/10.1016/s0232-4393(89)80126-x.

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Beril Tuḡrul, A. "Capillarity effect analysis for alternative liquid penetrant chemicals." NDT & E International 30, no. 1 (February 1997): 19–23. http://dx.doi.org/10.1016/s0963-8695(96)00044-8.

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Muthuthantri, S., A. R. Clarke, R. A. Hayes, and J. Kevin. "Effect of citrus peel chemicals onBactrocera tryonilarval survival." Acta Horticulturae, no. 1105 (December 2015): 349–56. http://dx.doi.org/10.17660/actahortic.2015.1105.50.

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Birnbaum, Linda S. "The effect of environmental chemicals on human health." Fertility and Sterility 89, no. 2 (February 2008): e31. http://dx.doi.org/10.1016/j.fertnstert.2007.12.022.

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Hess, Evelyn V. "Environmental chemicals and autoimmune disease: cause and effect." Toxicology 181-182 (December 2002): 65–70. http://dx.doi.org/10.1016/s0300-483x(02)00256-1.

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OYAMADA, Tetsuya, Shunsuke HANEHARA, Takuma TAKAHASHI, and Yohei HAYASAKA. "EFFECT OF DEICING CHEMICALS ON SCALING OF CONCRETE." Cement Science and Concrete Technology 65, no. 1 (2011): 354–59. http://dx.doi.org/10.14250/cement.65.354.

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Mainous, Mary E., Stephen A. Smith, and David D. Kuhn. "Effect of Common Aquaculture Chemicals againstEdwardsiella ictaluriandE. tarda." Journal of Aquatic Animal Health 22, no. 4 (December 2010): 224–28. http://dx.doi.org/10.1577/h10-020.1.

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Markova, Olga L., M. N. Kiryanova, E. V. Ivanova, and E. V. Zaritskaya. "WAYS FOR MINIMIZING THE NEGATIVE EFFECT OF TOBACCO AEROSOL COMPONENTS DURING PASSIVE SMOKING." Hygiene and sanitation 98, no. 6 (October 28, 2019): 682–87. http://dx.doi.org/10.18821/0016-9900-2019-98-6-682-687.

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Introduction. There are reported air quality assessment findings in enclosed spaces in experimental conditions using two kinds of nicotine-containing products - cigarettes and electronic nicotine delivery system (ENDS), seem to be the most common types of smoking. Мaterial and Methods. In the process of the experiment concentrations of tobacco aerosol components, i.e.: 12 chemicals and two aerosols were measured. Studies were carried out in isolated rooms under monitored microclimate parameters and uniform air mixing. Groups of volunteers using cigarettes or electronic nicotine delivery systems and the control non-smoker group participated in the study; everybody gave their informed consent for participation in the experiment. Control of background indices for comparison of air quality in rooms where tobacco products were being smoked was carried out. Results. Our studies allowing to identify chemicals evolving into the air of enclosed rooms where “PARLAMENT Aqua Blue” cigarettes were smoked or electronic tobacco delivery systems “CRICKET Classic 3.0” were used, to estimate total amount of chemicals in air. Prevailing chemicals affecting human health, which can be recommended for the use in calculations and air study of enclosed rooms exposed to tobacco aerosol, were identified. Estimated values of adverse chemical concentrations, air flow and air expenditure rate, resulting from experimental data allow designing ventilation system with regard to hygienic requirements based on maximum allowable concentration values for atmospheric air. Conclusions. Suggested recommendations on calculation of ventilation parameters to produce comfortable human environment in passive smoking conditions will improve air quality in public buildings.

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Hossen, Md Faruk, Sinin Hamdan, Md Rezaur Rahman, and Md Tipu Sultan. "The Effect of Fiber Chemical Treatment on Chemical Resistance Behavior of Jute Polyethylene Composites for Storage Tank Application." Materials Science Forum 997 (June 2020): 49–55. http://dx.doi.org/10.4028/www.scientific.net/msf.997.49.

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The jute polyethylene composites were developed using the hot-press technique with different fiber weight ratios. Due to the hydrophilic nature of fiber, it exhibited poor interfacial interaction to hydrophobic polymer matrix. In order to enhance the interfacial interaction between fiber and polymer, the benzene diazonium salt (BDS), propionic anhydride (PA), and 3-isocyanatopropyl triethoxysilane (silane) treated jute were used for the manufacturing of composites in this study. The chemical resistance tests of prepared composites were performed in order to probe whether these are resistant to various chemicals such as: acids, alkalis, and solvents. The effect of chemical treatments of the composites have been investigated. It was observed that the fabricated composites were resistant to all chemicals except carbon tetrachloride. The treated jute composites showed higher chemical resistance than raw jute composite and silane treated jute composite yield the highest resistance which can be suggested for making the water and chemical storage tanks.

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Dierickx, Paul J., Claudia Smit, and Ellen M. Scheers. "Cytotoxicity of the MEIC Reference Chemicals in Antioxidant-enriched Rat Hepatoma-derived Fa32 cells." Alternatives to Laboratory Animals 29, no. 3 (May 2001): 217–23. http://dx.doi.org/10.1177/026119290102900304.

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Since vitamin E increases the antioxidant status of cells, its influence on cytotoxicity was investigated. The neutral red uptake (NRU) inhibition effects of 39 MEIC reference chemicals were measured after treatment of rat hepatoma-derived Fa32 cells in the presence of vitamin E for 30 minutes. The results were quantified in terms of the NI50, the concentration of test compound required to reduce the NRU by 50%. Sodium chloride was the only chemical that was more toxic in the presence of vitamin E. This effect was related to the concentration of vitamin E in the cell culture medium. A vitamin E dose-related response was also observed for the decreased toxicity of paracetamol and caffeine. Glutathione levels were slightly increased in the presence of vitamin E, which could contribute to the protective effect of vitamin E. Of the remaining chemicals, 50% were less toxic in the presence of vitamin E, but the correlation with the acute human toxicity data of the MEIC study was not improved. The results imply that reactive oxygen species interfere with the toxicity of a high proportion of toxic chemicals. The assay described provides a quick and easy method for checking whether reactive oxygen species contribute to the toxicity of a chemical.

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Ribeiro, Felipe V., Bernardo A. P. da Gama, and Renato C. Pereira. "Structuring effects of chemicals from the sea fanPhyllogorgia dilatataon benthic communities." PeerJ 5 (April 4, 2017): e3186. http://dx.doi.org/10.7717/peerj.3186.

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Despite advances in understanding the ecological functions of secondary metabolites from marine organisms, there has been little focus on the influence of chemically-defended species at the community level. Several compounds have been isolated from the gorgonian octocoralPhyllogorgia dilatata, a conspicuous species that forms dense canopies on rocky reefs of northern Rio de Janeiro State, Brazil. Manipulative experiments were performed to study: (1) the effects of live colonies ofP. dilatata(physical presence and chemistry) on recruitment of sympatric benthic organisms; (2) the allelopathic effects of its chemicals on competitors; and (3) chemotactic responses of the non-indigenous brittle star,Ophiothela mirabilis. Early establishment of benthic species was influenced on substrates around liveP. dilatatacolonies and some effects could be attributed to the gorgonian’s secondary metabolites.In addition, the gorgonian chemicals also exerted an allelopathic effect on the sympatric zoanthidPalythoa caribaeorum,and positive chemotaxis uponO. mirabilis. These results indicate multiple ecological roles of a chemically-defended gorgonian on settlement, sympatric competitors, and non-indigenous species.

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Journal articles on the topic 'Effect of chemicals'

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