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The goal of this paper is to analyze the aging behavior and the mechanism evolution of nano-Al 2 O 3 (NA)-reinforced styrene-butadiene-styrene (SBS) asphalt under different thermal-oxidative aging conditions. First, NA/SBS-modified asphalt and SBS-modified asphalt with different aging levels were prepared. Second, the viscosity and high temperature rheological performance of the specimens were tested and the property-related aging indexes were calculated and compared. Third, a Fourier transform infrared (FTIR) test of the specimen was conducted and the chemical group-related aging indexes were calculated and analyzed. Fourth, gel permeation chromatography (GPC) was used to analyze the molecular weight of the specimens under different aging levels. Then, an atomic force microscope (AFM) was adopted to analyze the microsurface morphology of different specimens. Finally, correlation analysis between property-related indexes and chemical group indexes was conducted. The results show that NA can enhance the thermal-oxidative aging resistance of SBS asphalt. NA can inhibit the increase in sulfoxide groups and the degradation of the SBS polymer with the increase in aging. NA can slow down the formation of large molecule during the aging process. The degree of change in both the bee structures and micromorphological roughness of NA/SBS asphalt is lower than that of SBS asphalt under different aging levels.

The aim of this study was to explore the influence of the neurotoxicity of nanoalumina on primarily cultured neurons. Normal control, particle size control, aluminum, micron-alumina, and nanoalumina at 50-nm and 13-nm particle sizes were included as subjects to evaluate the level of apoptosis, necrosis, and autophagy in primarily cultured neurons and further explore the mitophagy induced by nanoalumina. The results demonstrated that nanoalumina could induce neuronal cell apoptosis, necrosis, and autophagy, among which autophagy was the most notable. When the autophagy inhibitor was added to the nanoalumina-treated group, it significantly downregulated the protein expression levels of Beclin-1 and LC3II/LC3. Observation under a transmission electron microscope and a fluorescence microscope revealed mitophagy characteristics induced by nanoalumina. Additionally, the neurotoxicological effects induced by nanoalumina were more significant than those induced by aluminum and in a particle size-dependent manner., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: This study aimed at investigating the effect of nanoalumina on sex hormones, and fetuses in pregnant rats., Methods: In this study, sixty-four pregnant rats were divided into eight groups. The control and the injection-control group received normal food and water, and 0.5 ml of distilled water, respectively. Treatment groups were treated with 25, 50, 100, 250, 500, and 1000µg/ml concentrations of Nanoalumina from the 7th day until the 18th day of pregnancy. On the 18th day, the rats were investigated in terms of their hormone levels. We evaluated the number of healthy and aborted offspring, as well as fetus size., Results: Nanoalumina caused an increase in progesterone hormones at the concentrations of 250, and 500µg/ml, and a significant reduction in estrogen hormone and aborted fetuses at the concentrations of 250 and 500µg/ml (p<0.05). The largest and smallest size of fetuses were observed in 500µg/ml and 1000µg/ml, respectively. The highest number of aborted fetuses was observed in the group treated with the 500µg/ml concentration. There was no aborted fetuses with 25, 50,100, control, and injection-control groups., Conclusions: Due to nanoalumina toxicity, it must be used with caution.

Although Nanoalumina is widely used in many biomedical applications, its potential toxic effect on pregnant women and developing embryos/fetuses has not been reported. In this investigation, the maternal and developmental toxicity caused by Nanoalumina during gestation and the potential preventive role of the pumpkin seed oil (PSO) were evaluated. Four groups of pregnant rats were orally administered during days 5-19 of gestation as follows: control group, Nanoalumina group (70 mg/kg b.w), PSO- group (4 ml/kg b.w.), and Nanoalumina plus PSO- group. Nanoalumina induced detrimental impacts in pregnancy outcomes, fetal growth retardation, morphological anomalies, hepatic and neural DNA damage, and histopathological changes in hepatic and neural tissues of both mother and fetus, respectively. Furthermore, the level of MDA is significantly increased and activities of GSH and CAT are significantly reduced in both tissues of nanoalumina-administered rats. PSO co administration improved pregnancy outcomes, fetal growth parameters, DNA damage, antioxidant defenses the histopathological changes of nanoalumina-gavaged rats and significantly diminished MDA level. Finally, PSO has a preventive role against the detrimental impacts of nanoalumina in dams and fetuses probably via its potential to prevent reactive oxygen species., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Author(s).)

Hypothesis: Cellulose-based aerogel, due to its rich reserves, environmental friendliness and porous structure, is considered as a new type of adsorbents for treating oil and water pollution. However, the functionalization of cellulose aerogel is still required for the efficient increase of its adsorption performance in wide applications. The combination of nanomaterials could significantly improve the adsorption capability of nanocellulose aerogel., Experiments: In this work, nanocomposite aerogels comprising of nanocellulose and nanoalumina (NC/Al 2 O 3 ) are produced via a solvent-free method and the effect of weight ratios between nanocellulose and nanoalumina on the adsorption properties of NC/Al 2 O 3 aerogels has been studied., Findings: The results reveal that the NC/Al 2 O 3 aerogel with a low density of 5.1 mg cm -3 could obtain the optimal pore microstructures and the highest oil and organic solvent adsorption capacities with the preparation condition under the nanocellulose/nanoalumina weight ratio of 1:0.25 and 0.4 wt% of nanocellulose in aqueous solution. The presence of nanoalumina facilitates the change of microstructure morphologies, the increase of BET specific surface area and the adsorption capacities of NC aerogel. Compared with pure NC aerogel (74.07 ± 1.67, 69.87 ± 1.01, 81.21 ± 3.20, 52.07 ± 1.70, 48.49 ± 1.01, 75.45 ± 3.58 and 87.03 ± 0.46 g g -1 for thiophene, anhydrous ethanol, ethyl acetate, cyclohexane, sesame oil, acetone and dichloromethane, respectively), the NC/Al 2 O 3 aerogel manifests an outstanding adsorption capacity (108.07 ± 0.37, 89.91 ± 4.83, 93.93 ± 3.81, 71.13 ± 2.48, 64.83 ± 2.25, 85.19 ± 3.87 and 117.65 ± 5.68 g g -1 , accordingly). By considering the desirable performance features and the convenient fabrication approach, this nanocellulose nanocomposite aerogel might be a feasible alternative for oily waste water recovery and conservation of environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Ultrahigh performance concrete (UHPC), which is characterized by dense microstructure and strain hardening behavior, provides exceptional durability and a new level of structural response to modern structures. However, the design of the UHPC matrix often requires the use of high quantities of supplementary cementitious materials, such as silica fume, which can significantly increase the cost and elevate the production expenses associated with silica fume handling. This paper demonstrates that a fiber-reinforced composite with properties similar to conventional UHPC can be realized with very low quantities of silica fume, such as 1% by mass of cementitious materials. The proposed UHPC is based on reference Type I cement or Type V Portland cement with very low C 3 A (<1%) that also complies with Class H oil well cement specification, silica fume, small quantities of Al 2 O 3 nanofibers, and high-density polyethylene or polyvinyl alcohol macro fibers. Previous research has demonstrated that nanofibers act as a seeding agent to promote the formation of compact and nanoreinforced calcium silicate hydrate (C-S-H) clusters within the interparticle and nanofiber spaces, providing a nanoreinforcing effect. This approach produces a denser and stronger matrix. This research expands upon this principle by adding synthetic fibers to ultrahigh strength cement-based composites to form a material with properties approaching that of UHPC. It is indicated that the developed material provides improved strain hardening and compressive strength at the level of 160 MPa.

Although studies showed effects of nanoalumina (nano-Al 2 O 3 ) on Escherichia coli, no study completely provides understanding on how bacterial cells respond to damages, especially on how they initiate self-defense. In this study, we showed three types of responses of E. coli to damages caused by nano-Al 2 O 3 . Live, dead, and injured, bacteria showed improved survival rates reaching 104%, 116%, and 104% after exposure to 0.1, 1, and 10mmol/L of nano-Al 2 O 3 respectively. Survival rates improved from 100% to 114%, corresponding to an exposure time of 0-9h, and from 100% to 127%, corresponding to 0-1000μg/L Al 3+ . Improvements were noted in survival rates of E. coli K12 MG1655, HB101, DH5α, and K12 MG1655 △lexA treated by nano-Al 2 O 3 in Luria-Bertani (LB) exposure system or K12 MG1655 in LB, normal saline(NS) and H 2 O exposure system. Bacterial cells transformed from long rods to ellipsoidal or nearly spherical as form of self-preservation mechanism; this phenomenon may be related to changes in membrane potential induced by free Al 3+ released from nano-Al 2 O 3 particles. Molecular mechanism of this response involved inhibited gene expression of sythesis and metabolism of carbohydrates, lipids and proteins. Findings presented in this study may improve understanding of potential danger of nanomaterials and control their spread to environmen., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The work aimed to evaluate the nanoalumina toxicity on the histological architecture, some haematological and biochemical aspects in male albino rats, during acute and sublethal experiments. Rats, in acute experiments, were injected with a single-acute dose of 3.9 g or 6.4 g or 8.5 g of aluminium oxide (Al2O3) kg(-) (1), whereas those of sublethal were injected with 1.3 g of Al2O3 kg(-) (1)2 days(-) (1) One-way analysis of variance indicated that injected doses and the experimental periods were significantly affected by haemoglobin (Hb) content; haematocrit value (Hct); white blood cell (WBC) count; blood platelet (Plt) count; mean corpuscular volume (MCV); mean corpuscular Hb (MCH) and MCH concentration (MCHC). In acute experiments, Hct, WBC count, MCV and Plt were significantly higher than the corresponding controls, whereas Hb, MCH and MCHC markedly decreased. In comparison with the related controls after 1, 3 and 7 days post-injection, red blood cell count, Hb, Hct, WBC count, Plt and MCV were significantly increased, but begun to decrease after 14 or/and 28 days and were associated with a marked decrease in MCH and MCHC. In serum of rats injected with acute or sublethal dose, the concentrations of total protein (TP) and total lipid (TL) were significantly lesser than the corresponding controls, whereas the levels of urea, uric acid, creatinine and the activities of aspartate aminotransferase and alanine aminotransferase were markedly increased. The injected doses were directly proportional with all the studied biochemical parameter, except the TL and TP that exhibited a negative correlation. Histologically, the highest acute and sublethal doses of nanoalumina caused hepatic irregular disarray, necrosis to the hepatic and Kupffer cells that are associated with congested blood sinusoids. The renal tissues characterized by the appearance of inter-tubular congestion that is accompanied by the dilation of the vascular glomeruli that completely occupied Bowman's capsule and accompanied with partial disappearance of the renal tubule's brush border. The brain showed a progressive degeneration of neurons in both the experiments., (© The Author(s) 2013.)

The present work aimed to evaluate the oxidative stress of nanoalumina (aluminium oxide nanoparticles, Al2O3-NPs) with a diameter <13 nm (9.83 ± 1.61 nm) as assessed by the perturbations in the enzymatic and non-enzymatic antioxidants as well as lipid peroxidation (LPO) in the brain, liver and kidney of male albino rats, after 2 days of single acute dose (3.9 or 6.4 or 8.5 g/kg) injection and a sublethal dose of 1.3 g/kg once in 2 days for a period of 28 days. According to two-way analysis of variance, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities as well as the levels of glutathione (GSH) and LPO were significantly affected by the injected doses, organs and their interactions. On the other hand, in sublethal experiments, these parameters were affected by the experimental periods, organs and their interactions. Regression analysis confirmed that the activities of SOD, CAT, GPx and GSH levels in the brain, liver and kidney were inversely proportional with the acute doses, the experimental periods, and aluminium accumulated in these tissues, whereas the levels of LPO exhibited a positive relationship. Correlation coefficient indicated that oxidative stress mainly depends on aluminium accumulated in the studied organs, followed by injected doses and the experimental periods. In comparison with the corresponding controls, the acute and sublethal doses of Al2O3-NPs caused significant inhibition of the brain, hepatic and renal SOD, CAT, GPx activities and a severe marked reduction in the concentrations of GSH that were associated with a significant elevation in the levels of malondialdehyde (an indicator of LPO). In conclusion, our data indicated that rats injected with nanoalumina suffered from the oxidative stresses that were dose and time dependent. In addition, Al2O3-NPs released into the biospheres could be potentiating a risk to the environment and causing hazard effects on living organisms, including mammals., (© The Author(s) 2013.)

The purpose of this study is to follow-up the distribution, lethality percentile doses (LDs) and bioaccumulation of aluminium oxide nanoparticles (Al2O3-NPs, average diameter 9.83 ± 1.61 nm) in some tissues of male albino rats, and to evaluate its genotoxicity to the brain tissues, during acute and sublethal experiments. The LDs of Al2O3-NPs, including median lethal dose (LD50), were estimated after intraperitoneal injection. The computed LD50 at 24 and 48 h were 15.10 and 12.88 g/kg body weight (b.w.), respectively. For acute experiments, the bioaccumulation of aluminium (Al) in the brain, liver, kidneys, intestine and spleen was estimated after 48 h of injection with a single acute dose (3.9, 6.4 and 8.5 g/kg b.w.), while for sublethal experiments it was after 1, 3, 7, 14 and 28 days of injection with 1.3 g/kg b.w. once in 2 days. Multi-way analysis of variance affirmed that Al uptake, in acute experiments, was significantly affected by the injected doses, organs (brain, liver, kidneys, intestine and spleen) and their interactions, while for sublethal experiments an altogether effect based on time (1, 3, 7, 14, 28 days), doses (0 and 1.3 g), organs and their interactions was reported. In addition, Al accumulated in the brain, liver, kidney, intestine and spleen of rats administered with Al2O3-NPs were significantly higher than the corresponding controls, during acute and sublethal experiments. The uptake of Al by the spleen of rats injected with acute doses was greater than that accumulated by kidney>brain>intestine>liver, whereas the brain of rats injected with sublethal dose accumulated lesser amount of Al followed by the kidney

In this paper the authors propose a framework for combining life cycle assessment (LCA) and Risk Assessment (RA) to support the sustainability assessment of emerging technologies. This proposal includes four steps of analysis: technological system definition; data collection; risk evaluation and impacts quantification; results interpretation. This scheme has been applied to a case study of nanofluid alumina production in two different pilot lines, "single-stage" and "two-stage". The study has been developed in the NanoHex project (enhanced nano-fluid heat exchange). Goals of the study were analyzing the hotspots and highlighting possible trade-off between the results of LCA, which identifies the processes having the best environmental performance, and the results of RA, which identifies the scenarios having the highest risk for workers. Indeed, due to lack of data about exposure limits, exposure-dose relationships and toxicity of alumina nanopowders (NPs) and nanofluids (NF), the workplace exposure has been evaluated by means of qualitative risk assessment, using Stoffenmanager Nano. Though having different aims, LCA and RA have a complementary role in the description of impacts of products/substances/technologies. Their combined use can overcome limits of each of them and allows a wider vision of the problems to better support the decision making process., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Complex engineered nanoparticles (CENPs), which have different core and surface components, are being developed for medicinal, pharmaceutical and industrial applications. One of the key challenges for environmental health and safety assessments of CENPs is to identify and quantity their transformations in biological environments. This study reports the effects of in vivo exposure of citrate-coated nanoalumina with different rare isotope labels on each component. This CENP was dosed to the rat and accelerator mass spectrometry (AMS) was used to quantify (26)Al, (14)C, and their ratio in the dosing material and tissue samples. For CENPs detected in the liver, the rare isotope ratio, (14)C/(26)Al, was 87% of the dosing material's ratio. The citrate coating on the nanoalumina in the liver was stable or, if it degraded, its metabolites were incorporated with nearby tissues. However, in brain and bone where little alumina was detected, the rare isotope ratio greatly exceeded that of the dosing material. Therefore, in the animal, citrate dissociated from CENPs and redistributed to brain and bone. Tracking both the core and surface components by AMS presents a new approach for characterizing transformations of CENPs components in biological milieu or environments., (Copyright © 2014 Elsevier B.V. All rights reserved.)