Quercetin in Food: Possible Mechanisms of Its Effect on Memory

Quercetin (3,3′,4′,5,7‐pentahydroxyflavone) is found in vegetables and fruits. It is one of the major flavonoids that is part of human diets. Quercetin has several pharmacological effects in the nervous system as a neuroprotective agent. In this review, we summarize the research on quercetin and its role in memory in both animals and humans. Articles were chosen from the Scopus, PubMed, and Web of Science databases. In this review, we describe and summarize the importance of quercetin's presence in the body, particularly in the brain; its kinetics, including its absorption, metabolism, distribution, and excretion; its behavioral effects; and some of the possible mechanisms of action of quercetin on memory in different animal models. Several important pathways that may be involved in the processes of learning and memory, long‐term potentiation, and cognition may be impaired during neurological diseases or other medical conditions. As dietary quercetin is important, provision of its best formulation for delivery to the brain as a nutraceutical and in clinical translational research for the prevention or treatment of Alzheimer's disease and other types of dementia is necessary.     

Thermal stability of additively manufactured austenitic 304L ODS alloy

Thermal stability and high-temperature mechanical properties of a 304L austenitic oxide dispersion strengthened(ODS)alloy manufactured via laser powder bed fusion(LPBF)are examined in this work.Additively manufactured 304LODS alloy samples were aged at temperatures of 1000,1100,and 1200℃for 100h in an argon atmosphere.Microstructure characterization of LPBF 304L ODS alloy before and after the thermal stability experiments revealed that despite the annihilation of dislocations,induced cellular substructure by the LPBF process was partially retained in the ODS alloy even after aging at 1200℃.The size of Y-Si-O nanoparticles after aging at 1200℃increased from 25 to 50 nm.EBSD analysis revealed that nanoparticles retained the microstructure of LPBF 304L ODS and hindered recrystallization and further grain growth.At 600℃and 800℃,the yield stress of the 290 and 145 MPa were measured,respectively,which are substantially higher than 113 MPa,and 68 MPa for 304L at the same temperatures.Furthermore,the creep properties of LPBF 304L ODS alloy were evaluated at a temperature of 700℃under three applied stresses of 70,85,and 100 MPa yielding a stress exponent(n)of～7.7;the minimum creep rate at 100 MPa was found to be about two orders of magnitude lower than found in the literature for wrought 304L stainless steel.     

Experimental investigation of preparing and using the H2O based nanofluids in the heating process of HVAC system model

In this experimental work, three types of water-based nanofluids are prepared by ultrasonic method. SiO₂, TiO₂ and CNT nanoparticles are used for preparing the nanofluids. Applications of these nanofluids are examined in the heating process in HVAC systems. During the experiments, total dissolved solids (TDS) of nanofluid are measured to see which nanofluid is more appropriate in heating process and makes the lower deposits and sediments. Also, heated area and nanofluid temperatures are recorded to show which nanofluid in suitable for heating from energy consumption view point. Results show that SiO₂ can be more suitable from the energy consumption view point because by lower energy consumptions, it reaches to desirable temperature in the heated area.     

Laboratory evaluation of the effect of SBS and Lucobite on performance properties of bitumen

In this research, the effects of two additives namely SBS (3, 5%) and Lucobite (3, 5%) on the performance properties of binder were evaluated. The binder fatigue and rutting performance was evaluated through linear amplitude sweep (LAS) and multiple stress creep and recovery (MSCR) test, respectively. Results indicated that 3% SBS modified binder has the highest percent recovery value and the lowest Jnr value, but had the highest sensitivity to a sudden increase in the stress level inside the asphalt mixture. The LAS test results demonstrated that the fatigue behavior of asphalt binders modified with 3% Lucobite, is the highest one.     

Impact of repeated loading on mechanical response of a reinforced sand

Pavements constructed over loosely compacted subgrades may not possess adequate California bearing ratio(CBR)to meet the requirements of pavement design codes,which may lead to a thicker pavement design for addressing the required strength.Geosynthetics have been proven to be effective for mitigating the adverse mechanical behaviors of weak soils as integrated constituents of base and sub-base layers in road construction.This study investigated the behaviors of unreinforced and reinforced sand with nonwoven geotextile using repeated CBR loading test(followed by unloading and reloading).The depth and number of geotextile reinforcement layers,as well as the compaction ratio of the soil above and below the reinforcement layer(s)and the compaction ratio of the sand bed,were set as variables in this context.Geotextile layers were placed at upper thickness ratios of 0.3,0.6 and 0.9 and the lower thickness ratio of 0.3.The compaction ratios of the upper layer and the sand bed varied between 85% and 97% to simulate a dense layer on a medium dense sand bed for all unreinforced and reinforced testing scenarios.Repeated CBR loading tests were conducted to the target loads of 100 kgf,150 kgf,200 kgf and 400 kgf,respectively(1 kgf = 9.8 N).The results indicated that placing one layer of reinforcement with an upper thickness ratio of 0.3 and compacting the soil above the reinforcement to compaction ratio of 97%significantly reduced the penetration of the CBR piston for all target repeated load levels.However,using two layers of reinforcement sandwiched between two dense soil layers with a compaction ratio of 97%with upper and lower thickness ratios of 0.3 resulted in the lowest penetration.     

Shear strength of a fibre-reinforced clay at large shear displacement when subjected to different stress histories

The topic of fibre-reinforced soil has been introduced and studied increasingly in the past few decades. However, the shear strength response of fibre-reinforced clay soils with different initial void ratio values when subjected to large shear displacement has not been explored in the literature. The purpose of this study is to evaluate the shear strength responses of fibre-reinforced clay soils when remoulded with relatively small and large initial void ratio and subjected to large shear displacement. In order to exclude the composition variability of the fibre-reinforced samples when subjected to various normal effective stresses, a series of multi-stage reverse drained direct shear test was undertaken with four reverse cycles of ±7 mm, ±7 mm, ±7 mm and +14 mm to achieve an accumulative horizontal shear displacement up to 56 mm that is 93% of the sample dimension. The first stage of the testing programme was carried out on soil samples consolidated at normal effective stress of 600 kPa and unloaded to 50 kPa, followed by 4 shear cycles at normal effective stresses of 50, 100 and 200 kPa, respectively. The results of these tests confirmed significant effective stress ratio improvement with fibre reinforcement, even at large shear displacement to the fourth cycle. However, the rate of improvement decreased with normal effective stress and initial void ratio. Based on the experiments carried out in this study, the optimum fibre content to increase the shear strength of the clay soil with initial void ratio of 0.64 was found to be 0.25% with 140%, 81% and 23% increase in the stress ratio over that of the unreinforced soil at normal effective stresses of 50, 100 and 200 kPa, respectively. The second stage of the testing programme was conducted on a set of samples consolidated and sheared at normal effective stresses of 50, 100 and 200 kPa, respectively. The optimum fibre content was found to be related only to the initial void ratio of the soil, irrespective of the stress history of the soil and the applied normal effective stress. The shear stress ratio of the fibre-reinforced clay soils at large shear displacement was found to be relatively independent of the stress history of the soil. For all soil samples tested in this study, the stress ratio at 200 kPa normal effective stress was found to remain between 0.45 and 0.60.     

Investigation of rutting performance of asphalt binders containing warm additive

In this research study, permanent deformation of pure and zycotherm modified binders were evaluated. Conventional test results showed that all percentages of zycotherm reduce susceptibility of binders to temperature. G^*/sinδ values of dynamic shear rheometer revealed that addition of zycotherm improves performance of binders against permanent deformation. Likewise, results of multistress creep recovery test indicated that zycotherm decreased the nonrecoverable compliance (Jnr) values, which is an indication of lower susceptibility of asphalt binders against rutting distress. According to test results, 0.1% of zycotherm is proposed to have the highest impact on performance of AC 85/100 asphalt binders against permanent deformation.     

Discussion on “Effects of lime addition on geotechnical properties of sedimentary soil in Curitiba,Brazil” [J Rock Mech Geotech Eng 10 (2018) 188–194]

The present discussion aims at complementing the original work published by Baldovino et al. (2018) by outlining a novel point of view. In light of the inherent limitations associated with the empirical model suggested in the original article, the dimensional analysis technique was introduced to the soil-lime strength problem, thereby leading to the development of simple and physically meaningful dimensional models capable of predicting the unconfined compressive and splitting tensile strengths of compacted soil-lime mixtures as a function of the mixture's index properties, i.e. lime content, initial placement (or compaction) condition, initial specific surface area and curing time. The predictive capacity of the proposed dimensional models was examined and validated by statistical techniques. The proposed dimensional models contain a limited number of fitting parameters, which can be calibrated by minimal experimental effort and hence implemented for predictive purposes.     

Stabilization of soft clay using short fibers and poly vinyl alcohol

In this study, the effect of the combined addition of fibers and a nontraditional polymer on the mechanical behavior of a clay was investigated. Poly vinyl alcohol, PVA, used as a solution with concentrations of 0.1%, 0.3%, 0.5%, 1.0% and 1.5% and 1,2,3,4 Butane Tetra Carboxylic Acid, BTCA was added as a crosslinking agent at concentration rates of 0.1%, 0.3% and 0.5%, respectively. Short polypropylene fibers were added to the clay at proportionate quantities of 0.25% and 0.50% of the dry weight of the soil. Clay samples were prepared for unconfined compressive strength (UCS) tests at two different initial void ratio values, denoting relatively stiff and markedly soft states. UCS tests were conducted on both 1-day and 14-day cured samples. The results confirmed significant UCS improvements with combined fiber reinforcement and PVA-BTCA stabilization when samples were cured for 14 days. It was also observed that fiber reinforcement outperformed PVA-BTCA stabilization for clays with the lower initial void ratio. PVA-BTCA stabilization was however found to be superior to fiber reinforcement in clays with a relatively higher initial void ratio. The effect of fiber reinforcement and PVA-BTCA stabilization on the stability of soils subjected to excessive wetting was also evaluated using soaking tests. Stabilization with PVA and BTCA was found to enhance the stability of soaked samples significantly. The results of soaking tests proved that BTCA made PVA-stabilized samples more durable when exposed to soaking.     

Detection of glioblastoma multiforme using quantitative molecular magnetic resonance imaging based on 5-aminolevulinic acid: in vitro and in vivo studies

Magnetic Resonance Materials in Physics, Biology and Medicine - We demonstrated a novel metabolic method based on sequential administration of 5-aminolevulinic acid (ALA) and iron supplement, and...