The downregulation of TREM2 exacerbates toxicity of development and neurobehavior induced by aluminum chloride and nano-alumina in adult zebrafish.

To investigate the difference in the development and neurobehavior between aluminum chloride (AlCl3) and nano-alumina (AlNPs) in adult zebrafish and the role of triggering receptor expressed on myeloid cells (TREM2) in this process. Zebrafish embryos were randomly administered with control, negative control, TREM2 knockdown, AlCl3, TREM2 knockdown + AlCl3, AlNPs, and TREM2 knockdown + AlNPs, wherein AlCl3 and AlNPs were 50 mg/L and TREM2 knockdown was achieved by microinjecting lentiviral-containing TREM2 inhibitors into the yolk sac. We assessed development, neurobehavior, histopathology, ultrastructural structure, neurotransmitters (AChE, DA), SOD, genes of TREM2 and neurodevelopment (α1-tubulin, syn2a, mbp), and AD-related proteins and genes. AlCl3 significantly lowered the malformation rate than AlNPs, and further increased rates of malformation and mortality following TREM2 knockdown. The locomotor ability, learning and memory were similar between AlCl3 and AlNPs. TREM2 deficiency further exacerbated their impairment in panic reflex, microglia decrease, and nerve fibers thickening and tangling. AlCl3, rather than AlNPs, significantly elevated AChE activity and p-tau content while decreasing TREM2 and syn2a levels than the control. TREM2 loss further aggravated impairment in the AChE and SOD activity, and psen1 and p-tau levels. Therefore, AlCl3 induces greater developmental toxicity but equivalent neurobehavior toxicity than AlNPs, while their toxicity was intensified by TREM2 deficiency.

Enhanced solidification/stabilization (S/S) of fluoride in smelting solid waste-based phosphogypsum cemented paste backfill utilizing biochar: Mechanisms and performance assessment.

Phosphogypsum (PG) cemented paste backfill (CPB) is a primary non-hazardous method for treating PG. However, using traditional binders like cement increases global carbon emissions and mining operational costs while complicating the reduction of fluoride leaching risks. This study introduces a novel PG-based CPB treatment method using steel slag (SS) and ground granulated blast furnace slag (GGBFS) as binders, calcium oxide as an exciter, with biochar serving as a fluoride-fixing agent. We investigated the effect of biochar addition on the hydration and solidification/stabilization (S/S) of fluoride in SS and GGBFS-PG-based materials (SSPC). The results indicated that the optimal strength and performance for fluoride S/S were achieved with a biochar addition of 0.2 wt%. Compared to the control group without biochar, the strength increased by 54.3%, and F leaching decreased by 39.4% after 28 days of curing for SSPC. The addition of 0.2 wt% biochar facilitated heterogeneous nucleation and acted as a microfiller, enhancing SSPC's properties. However, excessive biochar reduced the compactness of SSPC. Additionally, the distribution of fluoride was strongly correlated with P, Ca, Fe, and Al, suggesting that fluoride S/S is linked to the formation of stable hydration products like fluorapatite, fluorite, and complexes such as [AlF6]3- and [FeF6]3-. These findings offer a promising approach for the safe treatment of PG and the beneficial reuse of solid waste from SS and GGBFS.

Lnc001209 Participates in aluminium-induced apoptosis of PC12 cells by regulating PI3K-AKT-mTOR signalling pathway.

Aluminium (Al) is a common environmental neurotoxin, but the molecular mechanism underlying its toxic effects remains unclear. Many studies have shown that aluminium exposure leads to increased neuronal apoptosis. This study aimed to investigate the mechanisms and signalling pathways involved in aluminium exposure-induced neuronal apoptosis. The results showed a decrease in the number of PC12 cells and changes in cell morphology in the aluminium maltol exposure group. The viability of PC12 cells decreased gradually with increasing of exposure doses, and the apoptosis rate increased. The expression of Lnc001209 decreased gradually with an increase in the aluminium exposure dose. After transfection of Lnc001209 siRNA in aluminium-exposed PC12 cells, the protein expression levels of p-Akt Ser473, p-Akt Thr308, p-P85 Tyr467, p-mTOR Ser2448 and CD36 were increased. RNA pull-down MS showed that Lnc001209 interacts with the CD36 protein. Expression of the CD36 protein was increased in PC12 cells exposed to aluminium. The results of the CD36 intervention experiment showed that the protein expression levels of p-Akt Ser473, p-Akt Thr308, p-P85 Tyr467, and p-mTOR Ser2448 likely increased after CD36 overexpression. In addition, the phosphorylation level of AKT had the most significant increase. The enhancement of p-Akt activity promotes neuronal apoptosis.

Simultaneous effects of aluminum exposure on the homeostasis of essential metal content in rat brain and perturbation of gut microbiota.

The theory of the brain-gut axis has confirmed that gut microbiota and metabolites are involved in the progression of neurodegenerative diseases through multiple pathways. However, few studies have highlighted the role of gut microbiota in cognitive impairment induced by aluminum (Al) exposure and its correlations with the homeostasis of essential metal content in the brain. To explore the relationship between alterations in the content of essential metals in the brain and relative abundance changes in gut microbiota induced by Al exposure, the Al, zinc (Zn), copper (Cu), iron (Fe), chromium (Cr), manganese (Mn), and cobalt (Co) content level in the hippocampus, olfactory bulb, and midbrain tissue were measured by inductively coupled plasma mass spectrometry (ICP-MS) methods after Al maltolate was intraperitoneally injected every other day for exposed groups. Then the unsupervised principal coordinates analysis (PCoA) and linear discriminant analysis effect size (LEfSe) were used to analyze the relative abundance of the gut microbiota community and the structure of the gut microbiome. Finally, the correlations between gut microbiota composition and essential metal content in the different exposure groups were explored by using the Pearson correlation coefficient method. Based on the results, we indicated that the content of Al in the hippocampus, olfactory bulb, and midbrain tissue was increased and then decreased with the increasing exposure duration, with peaks occurring between 14 and 30 days. Concomitantly, Al-exposure decreased the Zn, Fe, and Mn levels in these tissues. 16 S rRNA gene sequencing results indicated that significant differences in the intestinal microbial community structure at the phylum, family, and genus levels were found in the Day 90 exposed group compared with the Day 7 exposed group. Ten enriched species in the exposed group were identified as markers at the three levels. Furthermore, ten bacteria at the genus level were identified to have a significantly strong correlation (r = 0.70-0.90) with Fe, Zn, Mn, and Co.

Increased aluminum and lithium and decreased zinc levels in plasma is related to cognitive impairment in workers at an aluminum factory in China: A cross-sectional study.

BACKGROUND: Previous studies have shown that multiple imbalances of metal ions in the brain are closely associated with the neurodegenerative disorders. Our studies have shown that long-term working exposure to aluminum induces increased plasma aluminum levels and causes cognitive impairment in workers at aluminum factories. OBJECTIVE: To explore the levels of nine metals in plasma and the effect on cognitive function among in-service workers. METHODS: In this cross-sectional study, cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), which included seven subitems: executive/visuospatial abilities; naming; attention and calculation; language; abstract; recall; and orientation. The plasma levels of nine kinds of metals were measured by inductively coupled plasma-mass spectrometry (ICP-MS). A multivariate generalized linear regression model and Bayesian kernel machine regression (BKMR) were selected to estimate the relationship between metal plasma level and MoCA scores with adjustment for confounders. RESULTS: One hundred and eighty-seven workers participated in this study. In the multivariable generalized linear model, among these nine metals studied, five were related to the MoCA score: aluminum, lithium, cobalt, zinc and chromium. In the BKMR model, a significantly negative correlation between the plasma aluminum, lithium and the total MoCA score was observed. Moreover, for subitems on the MoCA scale, the plasma levels of lithium, aluminum, and zinc had a significant correlation with the executive/visuospatial abilities, naming, and orientation abilities, respectively. The log-transformation concentrations of plasma aluminum and lithium were negatively correlated with the executive/visuospatial abilities and naming abilities, respectively. The log-transformation plasma zinc concentration was positively correlated with orientation abilities. CONCLUSION: Based on the results, we determined that increased aluminum and lithium and decreased zinc levels in plasma were associated with the incidence of mild cognitive impairment (MCI) in workers at a Chinese aluminum plant.

Utilization of modified copper slag activated by Na2SO4 and CaO for unclassified lead/zinc mine tailings based cemented paste backfill.

Serious heavy metals pollution was characterized in the lead/zinc mine tailings dam and surrounding soils, as well as copper slag disposal sites. This study investigates the efficacy of modified granulated copper slag (MGCS) as a partial replacement of ordinary Portland cement (OPC) for lead/zinc mine tailings-based cemented paste backfill (CPB) application using Na2SO4 (CSN) and CaO (CSC) as alkali-activated materials. The effect of different scenarios was ascertained by unconfined compressive strength (UCS). Also, the correlated microstructural evolution and mineralogical phase generation were obtained by scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), and X-ray diffraction (XRD). The main findings proved that CSN was more effective in improving mechanical performance. Na2SO4 was found associated with C-S-H gel formation accompanied by a compact microstructure and better pore distribution with lower porosity. However, deposition of chloride compound was found in the surface layer of CSN samples, which could bring deterioration to the mechanical properties. Results above extend the knowledge of reusing MGCS as supplementary material to CPB, promoting the concept of a circular economy demand for both lead/zinc mine extraction and copper industries.

Lithium slag and fly ash-based binder for cemented fine tailings backfill.

This research work was an exploration of the feasibility of utilizing a lithium slag (LS) and fly ash (FA)-based binder for cemented fine tailings backfill (CFTB). Extensive experiments were conducted with different combinations of LS and ordinary Portland cement (OPC), along with FA as an additive. The unconfined compressive strength (UCS), micromorphology and slump values were analyzed. The results showed that (i) the LS and FA had a significant influence on the strength of binders. The OPC-LS-FA ratio of 2:1:1 appeared to be optimal with the highest strength and was referred as the LS and FA-based binder (LFB). (ii) The LFB significantly improved the UCS of the CFTB. The UCS values of CFTB specimens curing for 7,28 and 56 days reached 0.95 MPa,2.28 MPa and 3.37 MPa, respectively, with a 10 wt% content of LFB. The strength satisfied the strength requirement of backfill for supporting the surrounding rock of stopes in the Yinshan lead-zinc mine (0.8 MPa, 2.0 MPa, 3.0 MPa). (iii) The pore-filling effect of the secondary hydration products, which was mainly produced by LFB, played a significant role in the early stage (<7 days), while the pozzolanic activity worked mostly in the mid-long period (>28 days). (iv) The LFB reduced the slump value of CFTB slurry by 2.6%-9.4% compared with OPC when the mass concentration increased from 58% to 64%, which was acceptable to satisfy the requirements of better fluidity and less transportation resistance in the Yinshan lead-zinc mine. Therefore, the LFB could be utilized as an alternative cementitious material for CFTB, which also provides a safe and economical approach to recycle LS and FA in an underground mine.

Aluminum-Induced Neural Cell Death.

Aluminum (Al), an abundant element in the earth's crust, is well-known for its neurotoxicity. Nonetheless, its causal role in neurodegenerative diseases, particularly in Alzheimer's disease (AD), is still in debate. Ample studies have shown that neural cell death and cognitive deficits induced by Al are similar to those in AD. In the present chapter, we demonstrate separately the Al-induced cell death in neuron, neuroglia cells, and co-cultured neural cells from newborn rats to illustrate the neurotoxic effects. Moreover, we not only examine the classic cell death pathways of apoptosis and necrosis but also compare with autophagy and a newly discovered cell death pathway known as necroptosis, which demonstrates its crucial roles in Al-induced neural cell death. Finally, we verify the cell death pathways attributed to the neural cell death in Al-induced AD-like mice model. The series research could provide an underlined mechanism and potential therapeutic agents to Al-induced neurodegenerative diseases.

[Hardware System for the Test of Artificial Joint Biomechanics].

In the research of artificial joint biomechanics, it is a common method in the world to evaluate the biomechanical properties of the implanted fixtures through experiments in vitro. The domestic research started late, and the corresponding testing methods were lacking. There is still no unified standard. In this paper, a complete hardware test system was designed and built around the existing mechanical testing machine, including:binocular vision catcher, torque bearing clamp, film pressure sensor and so on. The system can accurately measure the relative motion angle value, external torque value, and inter pressure value of each joint. It has some reference significance for the forming and standardization of the artificial joints' evaluation system.

[Development of Software System for Artificial Joint Biomechanics].

In the research of artificial joint biomechanics, it is a common method in the world to evaluate the biomechanical properties of the implanted fixtures through experiments in vitro. The domestic research started late, and the corresponding testing software were lacking. There is still no special software. In this paper, an integrated software test system was designed and built based on the existing hardware system, including:hardware control, data collection, data save, data processing and display. It can directly show the 3D motion trajectory and the angle curve of joints. The system can accurately measure the relative motion angle value, external torque value, and inter pressure value of each joint. It has some reference significance for the development of the artificial joints' evaluation system.

Alumina at 50 and 13 nm nanoparticle sizes have potential genotoxicity.

Although nanomaterials have the potential to improve human life, their sideline effects on human health seem to be inevitable and still are unknown. Some studies have investigated the genotoxicity of alumina nanoparticles (AlNPs); however, this effect is still unclear due to insufficient evaluation and conflicting results. Using a battery of standard genotoxic assays, the present study offers evidence of the genotoxicity associated with aluminum oxide (alumina) at NP sizes of 50 and 13 nm, when compared with bulk alumina (10 µm). The genotoxicity induced by alumina at bulk and NP sizes was evaluated with Ames test, comet test, micronucleus assay and sperm deformity test. The mechanism related to the induction of reactive oxygen species was explored as well. Our results showed that AlNPs (13 and 50 nm) were able to enter cells and induced DNA damage, micronucleus in bone marrow, sperm deformation and reactive oxygen species induction in a time-, dose- and size-dependent manner. Therefore, we conclude that AlNPs (13 and 50 nm), rather than bulk alumina, induce markers of genotoxicity in mice, with oxidative stress as a potential mechanism driving these genotoxic effects. Copyright © 2017 John Wiley & Sons, Ltd.

Utilization of phosphogypsum and phosphate tailings for cemented paste backfill.

This research is an investigation of the feasibility of utilizing phosphogypsum (PG) and phosphate tailings (PTS) for cemented paste backfill. Some experiments were conducted with various combinations of PTS and PG as aggregates, along with slags and/or Portland cement as binders and CaO as an additive. The influence of the PG's ageing time on the consolidation of backfill was also explored. The unconfined compressive strength (UCS), the generated gases and the scanning electron microscope (SEM) were all tested and used in the analysis of backfill characteristics. The results show that (i) the highest UCS of backfill prepared by PG and PTS after curing for either 7 days or 28 days is still less than 1.0 MPa, with a large amount of CO2 and SO2 generated; (ii) the slags can improve the UCS by a factor of three, but not without a vast generation of CO2, SO2, and H2S. However, the gases were not produced when CaO was added, but the UCS decreases suddenly to 0.2 or 0.4 MPa after curing for 7 days or 28 days, respectively; (iii) the UCS of backfill increases linearly with increasing cement content. When the CaO was added at 2%, the UCS reached 3.36 MPa after curing for 7 days and 4.44 MPa after curing for 28 days, and no gases were generated; (iv) the influence of the PG's ageing time on the UCS is negligible after 4 days of aging. Based on these results, it was concluded that PG and PTS can be utilized as backfill materials when Portland cement is used as a binder and CaO is used as an additive.

Effects of aluminium on ß-amyloid (1-42) and secretases (APP-cleaving enzymes) in rat brain.

Chronic administration of aluminium has been proposed as an environmental factor that may affect some pathological changes related to neurotoxicity and Alzheimer's disease (AD). The abnormal generation and deposition of ß-amyloid (Aß) in senile plaques are hallmark features in the brains of AD patients. Furthermore, Aß is generated by the sequential cleavage of the amyloid precursor protein (APP) via the APP cleaving enzyme (α-secretase, or ß-secretase) and γ-secretase. In the present study, we investigated the modulation of Aß deposition and neurotoxicity in aluminium-maltolate-treated (0, 15, 30, 45 mmol/kg body weight via intraperitoneal injection) in experimental rats. We measured Aß1-40 and Aß1-42 in the cortex and hippocampus in rat brains using ELISA. Subtypes of α-secretase, ß-secretase, and γ-secretase, including ADAM9, ADAM10, ADAM17 (TACE), BACE1, presenilin 1 (PS1) and nicastrin (NCT), were determined using western blotting analyses. These results indicated that aluminium-maltolate induced an AD-like behavioural deficit in rats at 30 and 45 mmol/kg body weight. Moreover, the Aß1-42 content increased significantly, both in the cortex and hippocampus, although no changes were observed in Aß1-40. Furthermore, ADAM9, ADAM10, and ADAM17 decreased significantly; in contrast, BACE1, PS1, and NCT showed significant increase. Taken together, these results suggest that the changes in secretases may correlate to the abnormal deposition of Aß by aluminium in rat brains.

[MAPK signaling pathways involved in aluminum-induced apoptosis and necroptosis in SH-SY5Y cells].

OBJECTIVE: To explore the role of MAPK signaling pathway in apoptosis and necroptosis induced by aluminum in SH-SY5Y cells. METHODS: To imitate neural cell death induced by aluminium, AlCl3 x 6H2O (4 mmol/L) was used to treat SH-SY5Y cells. Necrostatin-1 (Nec-1,60 µmol/L), the specific inhibitor for necroptosis, and zVAD-fmk (20 µmol/L), the specific inhibitor for apoptosis, were added into cultures for inhibiting the occurrence of necroptosis and apoptosis. CCK-8 was performed to measure cell viability, flow cytometry was used to test the difference of apoptosis rate and necrosis rate between groups, and western-blot was used to detect the change of MAPK protein. RESULTS: Compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group, cell viabiligy of Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group decreaced (P < 0.05). Compared with Al(3+) exposed group, cell viability of Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group increased (P < 0.05). Necrotic rate and apoptotic rate in Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group obviously increased compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group (P < 0.05). Compared with Al(3+) exposed group, necrotic and apaptotic rate of Al(3+) plus zVAD-fmk group and Al(3+) plus Nec-1 group were statistically significant decreased (P < 0.05). Compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group, expression of p-p38 in Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group increased obviously (P < 0.05), and expression of p-ERK decreased significantly (P < 0.05). Compared with Al(3+) exposed group, expression of p-p38 decreased (P < 0.05), but p-ERK increased in Al(3+) plus Nec-1 group (P < 0.05). CONCLUSION: The ERK and p38 MAPK signaling pathways are involved in aluminum-induced necroptosis in SH-SY5Y cells, but only ERK signaling pathway is involved in aluminum-induced apoptosis, and JNK signaling pathway is not involved in aluminum-induced cell death.

Nano-alumina induced developmental and neurobehavioral toxicity in the early life stage of zebrafish, associated with mTOR.

The study aims to investigate the effects of nano-alumina (AlNPs) on the early development and neurobehavior of zebrafish and the role of mTOR in this process. After embryos and grown-up larvae exposed to AlNPs from 0 to 200 µg/mL, we examined the development, neurobehavior, AlNPs content, and mTOR pathway genes. Moreover, embryos were randomly administered with control, negative control, mTOR knockdown, AlNPs, and mTOR knockdown + AlNPs, then examined for development, neurobehavior, oxidative stress, neurotransmitters, and development genes. As AlNPs increased, swimming speed and distance initially increased and then decreased; thigmotaxis and panic-avoidance reflex substantially decreased in the high-dose AlNPs group; aluminum and nanoparticles considerably accumulated in the 100 µg/mL AlNPs group; AlNPs at high dose decreased mTOR gene and protein levels, stimulating autophagy via increasing ULK1 and ULK2. mTOR knockdown exacerbated the harm to normal development rate, eye and body length, and neurobehavior induced by AlNPs through raising ROS, SOD, and ACH levels but decreasing AchE activity and development genes. Therefore, AlNPs suppress neurobehavior through downregulating mTOR, and mTOR knockdown further aggravates their early development and neurobehavior loss, suggesting mTOR could be a potential target for the toxicity of AlNPs.

[Effects of maternal exposure to nano-alumina during pregnancy on neurodevelopment in offspring mice].

OBJECTIVE: To observe the effects of maternal exposure to nano-alumina during pregnancy on the neurodevelopment in offspring mice. METHODS: Female ICR mice began to be exposed to nano-alumina 10 d before mating, and the nano-alumina exposure lasted till offspring mice were born. All the female mice were randomly divided into 5 groups: solvent control group (saline), nano-carbon group (11.76 mg/ml), micro-alumina group (50 mg/ml), 50 nm alumina group (50 mg/ml), and 13 nm alumina group (50 mg/ml). All the mice were treated by nasal drip (10 µl/time) 3 times daily till offspring mice were born. Physiological indices, reflex and sensory function test, endurance test, Morris water maze test, positioning and navigation test, and open field test were used to evaluate the neurodevelopment of newborn mice. RESULTS: On day 28, the body weight of 13 nm alumina group (16.73±4.04 g) was significantly lower than that of solvent control group (20.45±2.50 g) (P<0.01); the 13 nm alumina group had significantly delayed time to ear opening compared with the solvent control group (4.91±0.78 d vs 4.45±0.50 d, P<0.01); compared with the solvent control group, the nano-carbon group, micro-alumina group, 50 nm alumina group, and 13 nm alumina group had significantly delayed time to eruption of teeth (10.05±0.23 d vs 10.32±0.48 d, 10.75±0.45 d, 10.32±0.47 d, and 10.79±0.49 d, P<0.05 or P<0.01). On days 4 and 7 after birth, compared with the solvent control group, other groups had significantly decreased proportions of mice which passed the cliff avoidance test (P < 0.05 or P < 0.01). On days 12 and 14 after birth, compared with the solvent control group, the nano-carbon group, 50 nm alumina group, and 13 nm alumina group had significantly reduced pre-suspension time in the endurance test (P < 0.05 or P < 0.01). The Morris water maze and positioning and navigation tests showed that the 13 nm alumina group had a significantly increased 5 d incubation period compared with the solvent control group (P < 0.05); compared with the solvent control group, other groups had significantly reduced numbers of platform crossings (P < 0.05 or P < 0.01). The open field test showed that the nano-carbon group and 13 nm alumina group had reduced numbers of rearings compared with the solvent control group (P < 0.05); compared with the solvent control group, other groups had significantly reduced numbers of modifications (P < 0.01). CONCLUSION: Maternal exposure to nano-alumina (13 nm) during pregnancy has inhibitory effects on the physical development and early behavioral development in newborn mice and can also inhibit the learning and memory abilities and adaptability to new environment in offspring mice. The neurodevelopmental toxicity of nano-alumina to newborn mice increases as the particle sizes of nano-alumina decrease, which has been demonstrated by the endurance test and number of rearings.

In-situ remediation of phosphogypsum in a cement-free pathway: Utilization of ground granulated blast furnace slag and NaOH pretreatment.

In-situ remediating phosphogypsum (PG) for cemented paste backfill (CPB) in the contaminated site is economic management for promoting sustainable developments in the phosphate industry. This study concerns the combined use of NaOH pretreatment and ground-granulated blast furnace slag (GGBFS) additives to promote the solidification/stabilization of PG with a lower carbon footprint pathway. According to physico-chemical analyses, the NaOH pretreatment effectively removed approximately 95% of F within the PG, which may originally be present as sparingly soluble fluorides or coexisting with silicates. The micro mineralogical characterization illustrates that the pretreatment can accelerate the early age hydration, with more hydration products observed, including calcium silicate hydrates and ettringite, effective F and P retention candidates. Whereas the incorporation of GGBFS plays an essential role in promoting the generation of additional cement hydrates at the following stages. The macro mechanical performance analysis indicates that the mixtures of pretreated-PG-OPC-GGBFS exhibit an excellent mechanical performance satisfying the design criteria. Subsequent elemental mapping and toxicity characteristic leaching procedures demonstrate that this combined approach has a competitive F and P immobilization ability compared to the typical OPC binder and individual GGBFS addition. The newly formed phases effectively controlled the concentration of F and P through adsorption, incorporation, or encapsulation. Objectively, the proposed methodology can be a promising candidate pathway for extrapolating the in-situ immobilization of PG. This study opens up new perspectives for synergetically recycling PG and GGBFS in a profitable and low carbon footprint way.

Interaction between aluminum exposure and ApoEε4 gene on cognitive function of in-service workers.

The occurrence and development of cognitive impairment, the early stage of AD, may be affected both by factors of environmental (aluminum exposure) and genetic (ApoEε4 gene). But whether there is an interaction between the two factors on cognitive function is still unknown. To explore the interaction between the two factors on cognitive function of in-service workers. A total of 1121 in-service workers in a large aluminum factory were investigated in Shanxi Province. Cognitive function was assessed by the Mini-mental State Examination (MMSE), the clock-drawing test (CDT), the Digit Span Test (DST, including DSFT and DSBT), the fuld object memory evaluation (FOM), and the verbal fluency task (VFT). The plasma-Al (p-Al) concentrations were measured by inductively coupled plasma-mass spectrometry (ICP-MS) as an internal exposure indicator, and the participants were divided into four Al exposure groups according to the quartile of p-Al concentrations, namely Q1, Q2, Q3, and Q4. ApoE genotype was determined by Ligase Detection Reaction (LDR). The multiplicative model was fitted using non-conditional logistic regression and additive model was fitted using crossover analysis to analyze the interaction between p-Al concentrations and the ApoEε4 gene. Finally, a dose-response relationship between p-Al concentrations and cognitive impairment was observed, with the p-Al concentrations increased, cognitive function performance gradually becomes worse (Ptrend＜0.05), and the risk of cognitive impairment gradually increases (Ptrend＜0.05), mainly in executive/visuospatial impairment, auditory memory impairment (particularly the working memory impairment). And ApoEε4 gene may be a risk factor for cognitive impairment, while no association between the ApoEε2 gene and cognitive impairment is observed. Additionally, an additive but no multiplicative interaction between p-Al concentrations and ApoEε4 gene is observed, and when the two factors work together, the risk of cognitive impairment further increased, of which 44.2% can be attributed to the interaction effect.

[A method for simultaneous assay of propulsion and absorption in small intestine].

OBJECTIVE: To develop a method for simultaneous assay of propulsion and absorption in small intestine. METHODS: The mice were administrated through gastric tube with mixed reagents containing 0.12% phenol red, D-xylose (1.25%, 2.5% and 5%) and 15% gelatin. The influence of phenol red on D-xylose absorption and the influence of D-xylose on small intestine propulsion rate were investigated by measuring serum concentration of D-xylose with phloroglucinol method. RESULTS: At 10 min, no significant difference was found between 5% D-xylose mixed reagent group and 5% D-xylose control. At 15 min, small intestine propulsion rate in 5% D-xylose mixed reagent group, but not in 2.5% and 1.25% D-xylose mixed reagent groups, was significantly higher than in phenol red control (P<0.05). CONCLUSION: Gastric administration of mixed reagent containing 0.12% phenol red, 5% D-xylose and 15% gelatin can simultaneously assay propulsion and absorption of small intestine in mice.

Experimental Investigation on Red Mud from the Bayer Process for Cemented Paste Backfill.

Red mud is a by-product of alumina production, and its disposal can have severe environmental consequences. This study experimentally investigates the feasibility of using red mud from the Bayer process for cemented paste backfill (CPB). Different binders and activators were used to improve the mechanical properties, water resistance, and environmental behaviors of red mud-based CPB. In addition, water immersion tests were introduced, for the first time, to evaluate the water resistance of CPB. Furthermore, the environmental behaviors of red mud-based CPB were investigated by conducting leaching experiments. The results showed that the red-mud specimens had an unconfined compressive strength (UCS) of less than 0.2 MPa and disintegrated after being immersed in water. Different binders significantly improved the mechanical properties of red mud-based CPB. In addition, the specimens with different binders showed excellent water resistance, and the softening coefficient of CPB with different binders could exceed 0.7 after being cured for 28 days. The binders exhibited a substantial inhibitory effect on the leaching of hazardous substances in red mud under the solidification and stabilization effects. The leaching concentration of hexavalent chromium, selenium, fluoride, arsenic, lead, and vanadium was reduced by more than 70%. Therefore, this study provides an effective method for the environmental-friendly and large-scale utilization of red mud from the Bayer process.