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Recently, alkali-activated cement (AAC) has been studied to partially replace portland cement (PC) to reduce the environmental impact caused by civil construction and the cement industry. However, with regard to durability, few studies have addressed the behavior of AAC. This study aimed to evaluate the performance of AAC made from blast-furnace slag with contents of 4 and 5% sodium hydroxide as an activator (Na2Oeq of 3.72% and 4.42%, respectively) when subjected to alkali-aggregate reaction (AAR). Length variation tests were carried out on mortar bars immersed in NaOH solution (1 N of NaOH, T = 80°C [176°F]) and on concrete bars (T = 60°C [140°F], RH = 95%); compressive strengths tests and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) analyses were also made. Two types of PC were used as a comparison. The results showed good behavior of the AAC in relation to the AAR, with expansions lower than those established by the norm (34% of the limit) and without the finding of losses of mechanical resistance or structural integrity. The alkaline activator content had a small influence on the behavior of the AACs, in which the lowest amount of NaOH (4%) showed fewer expansions (only 15% of the limit established by the norm). Even for the highest activator content (5%), the results were good and comparable to those of PC with pozzolans, which is recommended for the inhibition of AAR. [ABSTRACT FROM AUTHOR]

Background: Two classes of medications are used to treat Alzheimer's disease (AD); donepezil, galantamine, and rivastigmine are acetylcholinesterase inhibitors, and memantine is a non-competitive antagonist of the N-methyl-D-aspartate receptor. Although these are typically taken orally, there are transdermal therapeutic systems (TTSs) commercially available for rivastigmine and donepezil. The transdermal route has been preferable for guardians/caregivers due to ease of use, reduced side effects, and improved adherence to therapy., Objective: The study aimed to obtain knowledge of the properties of these drugs and to search for patents relating to the TTS for AD using the Espacenet platform., Methods: The search terms were "rivastigmine AND transdermal AND skin delivery AND Alzheimer's", changing the drugs "memantine", "donepezil", and "galantamine", between January 2015 and January 2022. Title and abstract were used to choose patents., Results: TTSs present some limit factors in terms of absorption due to skin physiology and the size of the molecules with established limits of percutaneous penetration (molecular mass of 500 g/mol and log P of 5). We found 1, 4, 4, and 2 patents for galantamine, rivastigmine, donepezil, and memantine, respectively. Galantamine TTS seems to be more challenging due to the molecular mass of 287.35 g/mol and logP of 1.8. The permeator of absorption is necessary. Memantine, rivastigmine, and donepezil present logP of 3.28, 2.3, and 4.27 and molecular weights of 179.30, 250.34, and 415.96 g/mol, respectively., Conclusion: TTSs are primarily effective for delivering small molecules. The use of absorption enhancers and irritation mitigators can be necessary to enhance the performance. The development of these technologies is essential for the convenience of patients and caregivers., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)