(c) The toxicity of some insecticides, in particular pyrethrin (from chrysanthemums) and synthetic pyrethrins (pyrethroids), can be increased by the addition of compounds that are not themselves insecticides. These synergists are sesamin, sesamolin, piperonyl butoxide, MGK-264 (bicycloheptenedicarboxymide) and sesamex. Piperonyl butoxide is perhaps the most widely used synthetic pyrethrin synergist. The insecticidal activity of pyrethrins is increased tenfold when 1 part piperonyl butoxide is mixed with 9 parts pyrethrin. No toxic effects on humans from exposure to piperonyl butoxide have been reported. Antagonism – Antagonism is the opposite of synergy. This is the situation where the combined action of two or more compounds is less toxic than the individual effects; For example: The method was used to determine the synergistic effects of copper sulfate and Kathon (2-N-octyl-4-isothiazolin-3-one) on S. marcescens (Rodin et al., 2005). Amino alcohols are not biocides themselves, but they enhance the performance of a variety of biocides used in water-based liquids (Coburn et al. 2010).
Interactive vehicles are vehicles capable of delivering and extracting ingredients in exchange for their biological targets. You can interact with different barriers with certain shape-shifting abilities and overcome those barriers effectively. For example, very small liposomes (a term coined and protected as nanosomes) can encapsulate and transport water- and oil-soluble™ ingredients. These liposomes can exchange trapped molecules, including phospholipids and cholesterol, with cell membranes. When liposomes encounter an oil barrier in water, they can carry material or even entire liposomes on that medium. During their interactions, complex morphological and conformational changes in phospholipids as well as liposomal and cell membrane changes take place. [11] On the other hand, a synergy effect can be demonstrated in the economy in merger or acquisition situations where the merger of two companies may lead to a better overall competitive position and better financial results than the sum of their individual results. It can also be applied to the combination of products, such as in a lot or promotion, where larger sales can be made by adding the two products together in a single sales transaction, compared to the individual sale. a) Carbon tetrachloride and ethanol (ethyl alcohol) are individually toxic to the liver, but together they cause much more liver damage than the sum of their individual effects on the liver. In comparison, a synergistic effect is the situation in which the combined effect of two chemicals is much greater than the sum of the effects of each agent alone, for example: synergy refers to the interaction of biological structures or entities such that the total effect is greater than the sum of the individual effects.
The magnitude of the effect is so great that it cannot be replicated individually. Another related term is synergy. The latter is used in pharmacology. It refers to the condition in which a number of drugs produce synergistic effects, thereby increasing their effectiveness. The term is fundamentally associated with the idea that “the whole is greater than the sum of its parts.” (No. 1) Check out our What`s New list to see what`s been added or revised. The synergistic effect (S) can be defined as the ratio of the rates observed in the combined process (ultrasound and photocatalysis) to the sum of the rates of ultrasound alone and photocatalysis alone, S = ultrasound + photocatalysisRultrasound + Rphotocatalysis. Synergistic effects between radiation and temperature cycles have been observed for spacecraft materials during ground and space tests.
In one test, temperature changes caused the protective oxide layers on the FEP to delaminate and chip (Dever and de Groh, 2002). In this study, SiOx (where x~2) and a coating developed by OCLI consisting of alternating layers of SiO2, TiO2 and Ta2O3 were studied. The samples were exposed to 5 kGy 1 MeV electron radiation, followed by thermal cycling, nominally from -115°C to +90°C. While some OCLI-coated samples that were not exposed to radiation and temperature cycles showed signs of minor coating adhesion problems such as cracking and coating loss in curved areas, flaking and delamination were only observed in samples exposed to a temperature change after radiation. An example of the effects of electron radiation and temperature cycles on OCLI/FEP is shown in Fig. 28.22. The severity of delamination and flaking was worse with thicker coatings. Synergistic effects are non-linear cumulative effects of two active substances with similar or related results of their different activities or of active substances with sequential or complementary action. For example, vitamin E is an antioxidant and vitamin C can help recycle oxidized vitamin E into active vitamin E, so a synergistic effect[10] between the two may be possible. The illustrated series in Figure 14.13 shows a mechanism by which changes caused by two materials can lead to an effect greater than the simple sum of the effects of which each is individually capable.
(d) Barbiturate drugs have a greater effect on the central nervous system (CNS) by causing CNS depression when taken with general anesthetics, alcohol (acute use), narcotic analgesics (analgesics) and other sedative hypnotics. Try taking the quiz below to check out what you`ve learned about synergies so far. Ground-based environmental sustainability tests, such as those discussed in Townsend et al. (1998), suggest that exposure of materials during accelerated testing to environmental models predicting exposure of spacecraft to sources of UV and/or ionizing radiation does not simulate the extent of damage occurring in the space environment. One approach to overcoming the challenges of simulating the space environment through ground testing is to calibrate the facility using data from materials exposed to space to determine the exposure levels needed to replicate the deteriorated properties observed in space.