Metal-organic-framework-confined quantum dots enhance photocurrent signals: A molecularly imprinted photoelectrochemical cathodic sensor for rapid and sensitive tetracycline detection

BACKGROUND

Tetracycline (TC), a cost-effective broad-spectrum antibacterial drug, has been excessively utilized in the livestock and poultry industry, leading to a serious overabundance of TC in livestock wastewater. However, conventional analytical methods such as liquid chromatography and gas chromatography face challenges in achieving sensitive detection of trace amounts of TC in complex substrates. Therefore, it is imperative to develop a highly sensitive and anti-interference analytical method for the detection of tetracycline in livestock wastewater.

RESULTS

A porphyrin-based MOF (PCN-224)-confined carbon dots (CDs) material (CDs@PCN-224) was synthesized by a "bottle-around-ship" strategy. The reduced carrier migration distance is conducive to the separation of electron-hole pairs and enhanced the photocurrent signal due to the tight coupling of CDs and PCN-224. Further, molecularly imprinted polymer (MIP) was synthesized by rapid in-situ UV-polymerization and employed as a recognition element. The specific recognition of the target by imprinted cavities blocks electron transfer, resulting in a "turn off" response signal, thus realizing the selective detection of TC. Under optimal conditions, the constructed MIP-PEC cathodic sensor detected 1.00 × 10-12 M to 1.00 × 10-7 M of TC sensitively, with a limit of detection of 3.72 × 10-13 M. In addition, the proposed MIP-PEC sensor demonstrated good TC detection performance in actual livestock wastewater.

SIGNIFICANCE

The strategy based on MOF pore-confined quantum dots can effectively enhance the photocurrent response of the photosensitive substrate. Simultaneously, the MIP constructed by in-situ rapid UV-polymerization showed excellent anti-interference and reusable properties. This work provides a promising MIP-PEC cathodic sensing method for the rapid and sensitive detection of antibiotics in complex-matrix environmental samples.

Green and effective remediation of heavy metals contaminated water using CaCO3 vaterite synthesized through biomineralization

Heavy metal pollution has attracted significant attention due to its persistent presence in aquatic environments. A novel vaterite-based calcium carbonate adsorbent, named biogenic CaCO3, was synthesized utilizing a microbially induced carbonate precipitation (MICP) method to remediate heavy metal-contaminated water. The maximum Cd2+ removal capacity of biogenic CaCO3 was 1074.04 mg Cd2+/g CaCO3 with a high Cd2+ removal efficiency greater than 90% (initial Cd2+ concentration 400 mg/L). Furthermore, the biogenic CaCO₃ vaterite, induced by microbial-induced calcium carbonate precipitation (MICP) process, demonstrated a prolonged phase transformation to calcite and enhanced stability. This resulted in a sustained high effectiveness (greater than 96%) following six consecutive recycling tests. Additionally, X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses revealed that the semi-stable vaterite type of biogenic CaCO3 spontaneously underwent dissolution and recrystallization to form thermodynamic stable calcite in aquatic environments. However, the presence of Cd2+ leads to the transformation of vaterite into CdCO3 rather than undergoing direct converting to calcite. This transformation is attributed to the relatively low solubility of CdCO3 compared to calcite. Meanwhile, the biogenic CaCO3 proved to be an efficient and viable method for the removal of Pb2+, Cu2+, Zn2+, Co2+, Ni2+ and Mn2+ from water samples, surpassing the performance of previously reported adsorbents. Overall, the efficient and promising adsorbent demonstrates potential for practical in situ remediation of heavy metals-contaminated water.

Recent Trends in Self-Powered Photoelectrochemical Sensors: From the Perspective of Signal Output

Revolutionary developments in analytical chemistry have led to the rapid development of self-powered photoelectrochemical (PEC) sensors. Different from conventional PEC sensors, self-powered PEC sensors do not require an external power source or complex devices for the sensitive detection of targets. As a result, these sensors have enormous application potential for the development of novel portable sensors. An increasing body of work is making excellent progress toward the implementation of self-powered PEC sensors for detection, but there have been no reviews to date. The present review first introduces the state of the art in the development of self-powered PEC sensors. Then, different types of self-powered PEC sensors are summarized and discussed in detail, including their current, power, and potential. Additionally, single- and dual-photoelectrode systems are classified and systematically compared. Finally, the current developments and major challenges that need to be addressed are also summarized. This review provides valuable insights into the current state of self-powered PEC sensors to promote further progress in this field.

[Hsp90 participates in the necroptosis of mouse neural cells induced by aluminum through the RIP1/RIP3/MLKL pathway]

Objective: To investigate whether heat shock protein 90 (HSP90) participates in the necroptosis of C57BL/6 mouse neurons and spatial memory impairment induced by Aluminum maltol [Al (mal) (3)] through RIP1/RIP3/MLKL pathway. Methods: In March 2022, Thirty-two C57 mice were randomly divided into control group, Low dose group, a medium dose group, and a high-dose group, with 8 mice in each group, and injected intraperitoneally with physiological saline, 20, 40, and 80, respectivelyμmol/kgAl (mal) (3) was administered, it was injected 5 days a week and discontinued 2 days for 60 days. Morris water maze test was used to test the spatial learning and memory ability of mice. Nissl staining was used to observe the pathological changes of brain tissue. The protein expression levels of RIP1, RIP3, MLKL and HSP90 in hippocampus were determined by Western blotting. Results: In the water maze experiment, compared with the control group, the number of mice crossing the platform decreased in each dose group, the difference was statistically significant (H=9.50, P=0.023), and the number of mice crossing the platform was statistically significant among each dose group (P <0.05). Compared with the control group, the number of hippocampal nerve cells in each dose group decreased, the arrangement was disordered, and the Nissellite bodies decreased. Western blotting results showed that compared with the control group, the expression level of RIP1 protein in the hippocampus of mice in high-dose group was higher, and the difference was statistically significant (P <0.05). The expression levels of RIP3, MLKL and HSP90 in hippocampal tissue of mice in medium and high dose groups were increased, and the differences were statistically significant (P<0.05). After siRNA intervention decreased the expression of HSP90 protein, the expressions of HSP90, RIP1, RIP3 and MLKL in Al (mal) (3) groups were increased, and the differences were statistically significant (P<0.05) . Conclusion: Through RIP1/RIP3/MLKL pathway, HSP90 is involved in neuronal programmed necrosis and spatial memory impairment induced by maltol aluminum in C57 mice.

[Effect of miR-96-5p targeting IRS1 on apoptosis of PC12 cells induced by aluminum maltol]

Objective: To investigate the effect and mechanism of miR-96-5p on apoptosis of PC12 cells induced by maltol aluminum. Methods: In January 2021, PC12 cells at logarithmic growth phase were divided into blank control group and low, medium and high dose group. Cells in each group were treated with 0, 100, 200 and 400 μmol/L maltol aluminum for 24 hours respectively. Cells were collected and cell apoptosis rates were detected by flow cytometry, miR-96-5p and insulin receptor substrate 1 (IRS1) mRNA expressions were detected by qRT-PCR, and the protein expression levels of cysteine protease 3 (Caspase3) 、activated cysteine protease 3 (Cleaved-caspase3) 、IRS1、phosphorylated protein kinase B (p-AKT) and phosphorylated glucose synthesis kinase 3β (p-GSK3β) were detected by western blotting. The target binding relationship between miR-96-5p and IRS1 was detected by double luciferase reporter gene experiment. The miR-96-5p inhibitor cells and negative control cells were constructed after transfecting PC12 cells with miR-96-5p inhibitor for 24 hours. The cells were divided into blank control group, negative control group, aluminum exposure group, aluminum exposure+negative control group, aluminum exposure+miR-96-5p inhibition group, and miR-96-5p inhibition group. After transfecting PC12 cells with miR-96-5p inhibition and IRS1 siRNA for 24 h, the cells were divided into aluminum exposure+miR-96-5p inhibition+negative control group and aluminum exposure+miR-96-5p inhibition+IRS1 inhibition group. The control group was cultured in complete culture medium, and cells in the aluminum exposure group were treated with 200 μmol/L maltol aluminum for 24 hours. Cells in each group were collected and the apoptosis rate, miR-96-5p and IRS1 mRNA expression levels, as well as protein expression levels of Caspase3, Cleaved-caspase3, IRS1, p-AKT, and p-GSK3β were measured. Results: After 24 hours of exposure, compared with blank control group and low-dose group, the apoptosis rates, relative expressions of Caspase3 and Cleaved-caspase3 proteins, and relative expressions of miR-96-5p in the medium and high-dose groups of PC12 cells were significantly increased, while the relative expression levels of IRS1 mRNA, IRS1, p-AKT and p-GSK3β proteins were significantly decreased (P<0.05). Targetscan prediction and double luciferase report experiment both proved that IRS1 was a direct target gene of miR-96-5p. In the transfection experiment, compared with the aluminum exposure group, the apoptosis rate, the relative expressions of Caspase3 and Cleaved-caspase3 proteins, the relative expression of miR-96-5p in the aluminum exposure+miR-96-5p inhibition group were significantly decreased, while the relative expression levels of IRS1 mRNA and IRS1, p-AKT and p-GSK3β proteins were significantly increased (P<0.05). In the IRS1 low expression experiment, compared with the aluminum exposure+miR-96-5p inhibition+negative control group, the apoptosis rate, the relative expressions of Caspase3 and Cleaved-caspase3 proteins in the aluminum exposure+miR-96-5p inhibition+IRS1 inhibition group were significantly increased, while the relative expression levels of IRS1 mRNA and IRS1, p-AKT and p-GSK3β proteins were significantly decreased (P<0.05) . Conclusion: The increased expression of miR-96-5p and the targeted inhibition of IRS1 may be one of the mechanisms of apoptosis of PC12 cells induced by maltol aluminum exposure.

Gold nanocluster-confined covalent organic frameworks as bifunctional probes for electrochemiluminescence and colorimetric dual-response sensing of Pb2

The development of bifunctional signal probes based on a single component is highly desirable for sensitive and simple dual-mode detection of Pb²⁺. Here, novel gold nanocluster-confined covalent organic frameworks (AuNCs@COFs) were fabricated as a bisignal generator to enable electrochemiluminescence (ECL) and colorimetric dual-response sensing. AuNCs with both intrinsic ECL and peroxidase-like activity were confined into the ultrasmall pores of the COFs via an in situ growth method. On the one hand, the space-confinement effect of the COFs closed the ligand motion-induced nonradiative transition channels of the AuNCs. As a result, the AuNCs@COFs exhibited a 3.3-fold enhancement in anodic ECL efficiency compared to the solid-state aggregated AuNCs using triethylamine as the coreactant. On the other hand, due to the outstanding spatial dispersibility of the AuNCs in the structurally ordered COFs, a high density of active catalytic sites and accelerated electron transfer were obtained, leading to the promotion of the enzyme-like catalytic capacity of the composite. To validate its practical applicability, a Pb²⁺-triggered dual-response sensing system was proposed based on the aptamer-regulated ECL and peroxidase-like activity of the AuNCs@COFs. Sensitive determinations down to 7.9 pM for the ECL mode and 0.56 nM for the colorimetric mode were obtained. This work provides an approach for designing single element-based bifunctional signal probes for dual-mode detection of Pb²⁺.

Highly Fluorescent Magnetic ATT-AuNCs@ZIF-8 for All-in-One Detection and Removal of Hg2+: An Ultrasensitive Probe to Evaluate Its Removal Efficiency

The development of multifunctional materials for the synchronous detection and removal of mercury ions (Hg²⁺) is in high demand. Although a few multifunctional materials as a fluorescent indicator and adsorbent have achieved this aim, the feedback of their removal efficiency still depends on other methods. Herein, magnetic Fe₃O₄ nanoparticles (MNPs) and 6-aza-2-thiothymine-protected gold nanoclusters (ATT-AuNCs) were rationally assembled into a zeolitic imidazolate framework 8 (ZIF-8) structure via a one-pot method. The coordination assembly of ATT-AuNCs and ZIF-8 not only strengthened the aurophilic interactions of adjacent ATT-AuNCs but also induced the restriction of intramolecular motion of ATT with a six-membered heterocyclic structure. As a consequence, the fluorescence (FL) quantum yield of MNPs/ATT-AuNCs@ZIF-8 was 12.5-fold higher than that of pristine ATT-AuNCs. Benefiting from the enhanced FL emission, MNPs/ATT-AuNCs@ZIF-8 showed improved sensitivity for Hg²⁺ detection and therefore could evaluate the removal efficiency via FL detection, without relying on another detection method. Additionally, the nanocomposite also displayed a satisfactory removal capability for Hg²⁺, including a short capture time (20 min), a high removal efficiency (>96.9%), and excellent reusability (10 cycles). This work provides an approach for customizing functional nanocomposites to concurrently detect and remove Hg²⁺ with superior performance, especially for high detection sensitivity.

Electrochemical sensor based on Bi/Bi2O3 doped porous carbon composite derived from Bi-MOFs for Pb2+ sensitive detection

It is of great significance to develop electrochemical sensors based on novel functional nanomaterials for heavy metal ions detection. In this work, a novel Bi/Bi₂O₃ co-doped porous carbon composite (Bi/Bi₂O₃@C) was prepared by simple carbonization of bismuth-based metal-organic frameworks (Bi-MOFs). The micromorphology, internal structure, crystal and elemental composition, specific surface area and porous structure of the composite were characterized by SEM, TEM, XRD, XPS, and BET. Further, a sensitive electrochemical sensor for Pb²⁺ detection was constructed by modifying Bi/Bi₂O₃@C on the surface of the glassy carbon electrode (GCE) based on the square wave anodic stripping voltammetric (SWASV). The different factors affecting the analytical performance were optimized systematically, such as material modification concentration, deposition time, deposition potential, and pH value. Under optimized conditions, the proposed sensor exhibited a wide linear range from 37.5 nM to 2.0 μM with a low detection limit of 6.3 nM. Meanwhile, the proposed sensor showed good stability, acceptable reproducibility, and satisfactory selectivity. The reliability of the as-proposed sensor was confirmed by the ICP-MS method for Pb²⁺ detection in different samples.

Monitoring mild cognitive impairment of workers exposed to occupational aluminium based on quantitative susceptibility mapping

AIM

To investigate the diagnostic value of quantitative susceptibility mapping (QSM) in mild cognitive impairment (MCI) of aluminium (Al) workers.

MATERIALS AND METHODS

The basic data of 53 workers in an Al factory were collected and divided into the MCI group and normal control (NC) group by Montreal Cognitive Assessment (MoCA) scores. All participants were tested for plasma Al concentration and had magnetic resonance imaging (MRI). The QSM values of many areas of the brain were delineated and measured. Independent two-sample t-tests or non-parametric tests were used to compare the parameter values between the two groups. Spearman's correlation analysis was performed between QSM values, MoCA scores, and plasma Al concentration. The receiver operating characteristic curve and z test were performed to assess diagnostic efficacy and the best parameter.

RESULTS

There was no difference in age and educational level. Plasma Al concentration of the MCI group was higher than that of NC group (p=0.057). QSM values of the left hippocampus, left dentate nucleus, right substantia nigra, and left putamen in MCI group were higher than that of NC group (p<0.05), and the left hippocampus had the best diagnostic efficacy. QSM values correlated negatively with MoCA scores. No correlation was found between QSM values and plasma Al concentration (p>0.05).

CONCLUSION

QSM might be a neuroimaging marker for the diagnosis of MCI. The left hippocampus showed the best diagnostic efficacy. Plasma Al concentration of the MCI group was higher than that of the NC group. A correlation between QSM and plasma Al concentration was not found.

Boosting the singlet oxygen production from H2O2 activation with highly dispersed Co-N-graphene for pollutant removal

Singlet oxygen (¹O₂) is a promising reactive species for the selective degradation of organic pollutants. However, it is difficult to generate ¹O₂ from H₂O₂ activation with high efficiency and selectivity. In this work, a graphene-supported highly dispersed cobalt catalyst with abundant Co-N _x active sites (Co-N-graphene) was synthesized for activating H₂O₂. The Co-N-graphene catalyzed H₂O₂ reaction system selectively catalyzed ¹O₂ production associated with the superoxide radical (O₂˙^-) as the critical intermediate, as proven by scavenger experiments, electron spin resonance (ESR) spin trapping and a kinetic solvent isotope effect study. This resulted in excellent degradation efficiency towards the model organic pollutant methylene blue (MB), with an outstanding pseudo-first-order kinetic rate constant of 0.432 min^-1 (g L_catalyst ^-1)^-1 under optimal reaction conditions (C _H2O2 = 400 mM, initial pH = 9). Furthermore, this Co-N-graphene catalyst enabled strong synergy with HCO₃ ^- in accelerating MB degradation, whereas the scavenger experiment implied that the synergy herein differed significantly from the current Co²⁺-HCO₃ ^- reaction system, in which contribution of O₂˙^- was only validated with a Co-N-graphene catalyst. Therefore, this work developed a novel catalyst for boosting ¹O₂ production from H₂O₂ activation and will extend the inventory of catalysts for advanced oxidation processes.

Highly dispersed and stable nano zero-valent iron doped electrospun carbon nanofiber composite for aqueous hexavalent chromium removal

In this work, a nZVI doped electrospun carbon nanofiber (nZVI-CNF) composite was prepared and applied for aqueous hexavalent chromium (Cr(vi)) removal. Firstly, FeCl₃/PAN nanofibers were prepared by a simple electrospinning method; Then, nZVI-CNFs were obtained by carbonization of FeCl₃/PAN nanofibers at 800 °C. The surface morphology and internal structure of nZVI-CNFs were characterized by SEM and TEM, showing that the uniformly dispersed nZVI particles were well integrated into the carbon layer structure. The Cr(vi) removal efficiency of nZVI-CNFs was 91.5% with a Cr(vi) concentration of 10 mg L⁻¹ and the mechanism was further studied by XRD and XPS. Meanwhile, the nZVI-CNFs exhibited good stability over a wide range of pH values from 4–8 and a long time placement stability. Furthermore, nZVI-CNFs can be used as a filter membrane for continuous treatment of wastewater, suggesting great potential for practical application.

Improving the dispersion and stability of nano zero-valent iron (nZVI) is very important for its practical application.

[The impact of occupational aluminum exposure on workers' overall cognitive function and various cognitive fields]

Objective: To evaluate the effects of occupational aluminum exposure on workers' overall cognitive function and cognitive fields. Methods: From July to August 2019, using the method of cluster sampling, 101 and 117 workers were selected from the electrolytic aluminum workshop of an aluminum plant in a region and the maintenance workshop of a plant in the same region. The venous blood of the subjects was collected, the plasma was extracted, and the blood aluminum concentration was measured by ICP-MS. According to the blood aluminum concentration and type of work, 93 workers who were lower than the median blood aluminum concentration and in the maintenance workshop of a factory were divided into low aluminum exposure group, and 85 workers who were higher than the median blood aluminum concentration and in the electrolytic aluminum workshop of an aluminum factory were divided into high aluminum exposure group. The basic information of the respondents, was collected through the employee physical examination form. The overall cognitive function of workers was evaluated by Beijing Montreal Cognitive Assessment Scale (MoCA) . Multiple linear regression analysis and logistic regression analysis were used for multiple statistical analysis. Results: Compared with the low aluminum exposure group (25.42±1.808) , the total score of MoCA in the high aluminum exposure group (23.84±2.919) was significantly lower, and the scores of visual space, executive function, abstract and delayed recall were significantly lower (P<0.05) . Linear regression analysis showed that the total score of MoCA, visual space and executive function, naming and delayed recall were negatively correlated with blood aluminum concentration (β=-0.018、-0.008、-0.003、-0.008, P<0.05) .MOCA total score, visual space and executive function, attention, language, abstraction, orientation were positively correlated with educational level (β=0.853、0.310、0.216、0.171、0.412、0.122, P<0.05) . Logistic regression analysis showed that adjusting for age, smoking, drinking and education, blood aluminum was a risk factor for mild cognitive impairment (OR=1.017, P<0.05) ; Education level was the protective factor of mild cognitive impairment (OR=0.419, P<0.05) . Conclusion: Occupational aluminum exposure can affect the overall cognitive function of workers, and occupational aluminum exposure increases the risk of MCI.

[Effects of occupational exposure to aluminum on verbal function of workers]

Objective: To explore the effect of occupational aluminum (Al) exposure on workers' overall cognitive level and speech function. Methods: In July 2019, by using cluster sampling method, the group of 232 exposed to Al from an Al plant in Shanxi Province were selected as the exposed group, and the group of 228 not exposed to Al were selected as the control group. The blood Al concentration was determined by inductively coupled plasma mass spectrometry (ICP-MAS) . The exposed group was divided into high exposure group and low exposure group according to the median (M) concentration of Al in serum. The general cognitive function and speech function were evaluated with the Montreal Cognitive Assessment Scale (MoCA) , and the differences in the general cognitive function and speech function between the groups were compared, and non-conditional logistic regression was used to analyze the possible influencing factors of mild cognitive impairment (MCI) . Results: There were significant differences in age, working age, education and drinking status between Al exposed group and control group (P<0.05) . The total MoCA score, animal naming tese (ANT) score and category fluency repetition (CFT) score in Al exposure group were lower than control group and the differences were statistically significant (P<0.05) . The full rate of ANT was lower than that of CFT in Al exposure group (P<0.05) . The total MoCA score, ANT score and CFT score in the high exposure group were significantly lower than those in the control group (P<0.05) . The score of MoCA, ANT and CFT in high exposure group were lower than those in low exposure group between the level of serum aluminum>60 μg/L group and ≤60 μg/L group (P<0.05) . Logistic regression analysis showed that working age, serun Al concentration, ANT score, CFT score and SR score were the possible influencing factors of MCI in occupational Al exposure workers (P<0.05) . Conclusion: Occupational Al exposure can lead to impaired speech function of workers, the higher the ANT score, CFT score and SR score, the lower working age and serum Al concentration, the lower risk of MCI.

Copy number variation in HOXB7 and HOXB8 involves in the formation of beard trait in chickens

The derived feathering phenotype beard in domestic birds is an ideal resource to investigate the genetic mechanisms controlling feather development and differentiation. In the present study, we performed a GWAS and QTL linkage analysis on the trait of beard in Beijing fatty chicken. One major QTL (1.2-1.9 Mb) was identified that could explain 34% of the phenotypic variation. The copy number variation that was copied from the region (GGA27:3 578 409-3 592 890 bp) containing homebox B7 (HOXB7) and homebox B8 (HOXB8) was validated to be only exhibited in the genome of bearded chickens. Protein-protein interaction analysis indicated that HOXB7 and HOXB8 proteins could highly interact with the HOXB family members, including HOXB4, HOXB5 and HOXB6, whose genomic locations near HOXB7 and HOXB8 suggested that they may regulate their family members to involve in the formation of the beard trait in chickens. Overall, our work provides basic data for understanding the mechanisms regulating beard development and differentiation.

Self-made Salmonella Pullorum agglutination antigen development and its potential practical application

Pullorum disease caused by Salmonella Pullorum is one of the most important infectious diseases in the poultry industry worldwide, which leads to serious economic losses in many developing countries because of its high mortality rate in young chicks. The traditional slide agglutination test with low cost, fast reaction, and on-site detection has been widely used in the diagnosis of Pullorum disease. However, in practice, the test performance is with the disadvantages of false positive results and unstable detection results. In this paper, we developed self-made agglutination antigens prepared by local isolates in the poultry farm and compare the detection performance with commercial agglutination antigens (China Institute of Veterinary Drug Control) and Group D Salmonella ELISA kit (BioChek UK Ltd). The results of detecting 200 serum samples indicated that the consistency of commercial agglutination antigen detecting in 2 times was only 79.5%. Using the ELISA kit as the reference method, the commercial agglutination antigen detecting results of the Kappa test were only moderately consistent (0.58 ∼ 0.59). Meanwhile, positive and total coincidence rates of the self-made agglutination antigen test with more reliable repeat could reach 97.4 and 88%, respectively, and the result of Kappa test was highly consistent (0.75). The Receiver Operating Characteristic curve analysis clarified that the area under the receiver-operating-characteristic curve values of self-made and commercial agglutination antigen tests could reach 0.861 and 0.804, respectively. These results were coincident when detecting known positive serum from the infected chickens. It's worth mentioning that the visible positive reaction of self-made agglutination antigen test appeared faster and stronger than commercial antigen test. In conclusion, self-made Salmonella Pullorum agglutination antigen developed in this study was much better than commercial agglutination antigen and is expected to be a valuable tool in the diagnosis of the epidemiology of Salmonella Pullorum.

Fermi-Surface Instability in the Heavy-Fermion Superconductor UTe_{2}

Transport measurements are presented up to fields of 29 T in the recently discovered heavy-fermion superconductor UTe_{2} with magnetic field H applied along the easy magnetization a axis of the body-centered orthorhombic structure. The thermoelectric power varies linearly with temperature above the superconducting transition, T_{SC}=1.5  K, indicating that superconductivity develops in a Fermi liquid regime. As a function of field the thermoelectric power shows successive anomalies which appear at critical values of the magnetic polarization. Remarkably, the lowest magnetic field instability for H∥a occurs for the same critical value of the magnetization (0.4  μ_{B}) than the first order metamagnetic transition at 35 T for field applied along the b axis. It can be clearly identified as a Lifshitz transition. The estimated number of charge carriers at low temperature reveals a metallic ground state distinct from LDA calculations indicating that strong electronic correlations are a major issue.

Occupational allergy: is there a role for nanoparticles?

All fields of industry are applying nanotechnologies for the development of advanced materials, there¬fore at present the number of workers exposed to nanosized materials are significantly increasing. Unfortunately, protective equipment for nanoparticles (NPs) is of uncertain efficacy so the risk of noxious effects, in particular allergic sensitization, on workers gives many concerns. At the same time, studies of allergic physiopathology demonstrated that the lack of prevention and treatment could result in invalidating dis¬eases that, in case of professional etiology, might imply removal from the job and compensation. Therefore, a deeper knowledge of the role of NPs in inducing allergic diseases is mandatory to implement the risk assessment and preventive measures for nanosafety in the workplace. The possibility that NPs favor, ex¬acerbate or directly induce allergy is being suggested by recent experimental investigations in cellular and animal models. Unfortunately, studies are heterogeneous and few data have received experimental confir¬mation, lacking reproducibility. What comes to attention is the uncertainty about the real plausibility of the observed experimental effects, as there are only a few reported cases of allergy onset or exacerbation for workers exposed to NPs. However, the potential for NPs to induce, favor or exacerbate allergies seems possible even though not completely demonstrated. This should be a greater incentive to carry out appro¬priate epidemiological studies that are lacking and really needed.

Flexible, Porous, and Metal-Heteroatom-Doped Carbon Nanofibers as Efficient ORR Electrocatalysts for Zn-Air Battery

Developing an efficient and durable oxygen reduction electrocatalyst is critical for clean-energy technology, such as fuel cells and metal-air batteries. In this study, we developed a facile strategy for the preparation of flexible, porous, and well-dispersed metal-heteroatom-doped carbon nanofibers by direct carbonization of electrospun Zn/Co-ZIFs/PAN nanofibers (Zn/Co-ZIFs/PAN). The obtained Zn/Co and N co-doped porous carbon nanofibers carbonized at 800 °C (Zn/Co-N@PCNFs-800) presented a good flexibility, a continuous porous structure, and a superior oxygen reduction reaction (ORR) catalytic activity to that of commercial 20 wt% Pt/C, in terms of its onset potential (0.98 V vs. RHE), half-wave potential (0.89 V vs. RHE), and limiting current density (- 5.26 mA cm^-2). In addition, we tested the suitability and durability of Zn/Co-N@PCNFs-800 as the oxygen cathode for a rechargeable Zn-air battery. The prepared Zn-air batteries exhibited a higher power density (83.5 mW cm^-2), a higher specific capacity (640.3 mAh g^-1), an excellent reversibility, and a better cycling life than the commercial 20 wt% Pt/C + RuO₂ catalysts. This design strategy of flexible porous non-precious metal-doped ORR electrocatalysts obtained from electrospun ZIFs/polymer nanofibers could be extended to fabricate other novel, stable, and easy-to-use multi-functional electrocatalysts for clean-energy technology.

[The study of the effects of occupational aluminum exposure on TNFR1 expression and cognitive function]

Objective: To analyze the relationship between cognitive function and tumor necrosis factor receptor 1 (TNFR1) expression of occupational exposed workers to aluminum and provide the basis for the diagnosis of cognitive impairment. Methods: 140 cases Shanxi aluminum plant workers were collected in 2016 as the research object, including 70 potroom workers for exposure group, 70 non-electrolytic aluminum plant workers in the control group, respectively. Using mini mental status examination (MMSE), digit span test (DST), fuld object memory examination(FOME) and simple reaction time test(SRTT) evaluate the cognitive function of objects. Using graphite furnace atomic absorption method for the determination of plasma aluminum levels as an indicator of aluminum contact exposure of workers. Using RT-PCR method for detection of tumor necrosis factor receptor 1 (TNFR1) mRNA expression levels. And comparison group differences in cognitive and TNFR1 mRNA expression levels. Results: The plasma aluminum content of exposed group (77.12±27.18) μg/L higher than the control group (55.6±28.69)μg/L (P=0.000); Compared to control group, FOME and MMSE score was significantly increased in the exposed group (P=0.000, P=0.000), SRTT scores significantly higher in the exposed group (P=0.001), DST no significant difference in the control group (P=0.893). Compared to control group, The mRNA expression of TNFR1 was significantly higher in the exposed group(P=0.002); Compared to control group, The protein expression of TNFR1 was significantly higher in the exposed group (P=0.002). By correlation analysis in exposure group, plasma aluminum content was negatively correlated with MMSE and the DST (r=-0.284, r=-0.331, P<0.05) and positively correlated with the SRTT, TNFR1 (mRNA) and TNFR1(protein)(r=0.255, r=0.333, r=0.987, P<0.01), MMSE was negatively related to TNFR1 (mRNA) and TNFR1 (protein) (r=-0.268, r=-0.255, P<0.05); DST was negatively correlated with the SRTT and TNFR1 (protein)(r=-0.267, r=-0.330, P<0.05); SRTT was positively correlated with TNFR1 (protein)(r=0.243, P<0.05); TNFR1 (mRNA) was positively correlated with TNFR1 (protein)(r= 0.340, P<0.01). Conclusion: Cognitive function change of occupational exposed workers to aluminum was related to the increase of TNFR1 expression.

Maximizing T c by tuning nematicity and magnetism in FeSe1-x S x superconductors

A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature (T c). To address this issue, FeSe is a key material, as it exhibits a unique pressure phase diagram involving non-magnetic nematic and pressure-induced antiferromagnetic ordered phases. However, as these two phases in FeSe have considerable overlap, how each order affects superconductivity remains perplexing. Here we construct the three-dimensional electronic phase diagram, temperature (T) against pressure (P) and isovalent S-substitution (x), for FeSe1-x S x . By simultaneously tuning chemical and physical pressures, against which the chalcogen height shows a contrasting variation, we achieve a complete separation of nematic and antiferromagnetic phases. In between, an extended non-magnetic tetragonal phase emerges, where T c shows a striking enhancement. The completed phase diagram uncovers that high-T c superconductivity lies near both ends of the dome-shaped antiferromagnetic phase, whereas T c remains low near the nematic critical point.

Quasilinear quantum magnetoresistance in pressure-induced nonsymmorphic superconductor chromium arsenide

In conventional metals, modification of electron trajectories under magnetic field gives rise to a magnetoresistance that varies quadratically at low field, followed by a saturation at high field for closed orbits on the Fermi surface. Deviations from the conventional behaviour, for example, the observation of a linear magnetoresistance, or a non-saturating magnetoresistance, have been attributed to exotic electron scattering mechanisms. Recently, linear magnetoresistance has been observed in many Dirac materials, in which the electron–electron correlation is relatively weak. The strongly correlated helimagnet CrAs undergoes a quantum phase transition to a nonmagnetic superconductor under pressure. Here we observe, near the magnetic instability, a large and non-saturating quasilinear magnetoresistance from the upper critical field to 14 T at low temperatures. We show that the quasilinear magnetoresistance may arise from an intricate interplay between a nontrivial band crossing protected by nonsymmorphic crystal symmetry and strong magnetic fluctuations.

The electronic structure of the helimagnet CrAs is unusual due to its nonsymmorphic crystal symmetry. Here, the authors observe quasilinear magnetoresistance close to a pressure-driven superconducting transition, which may arise from the interaction of the band structure and magnetic fluctuations.

[The effect of aluminum trichloride on expression of phosphorylated tau and Aβ in SH-SY5Y cells]

Objective: To investigate the expression of phosphorylated tau (p-tau) and Aβ in SH-SY5Y cells induced by aluminum or/and ApoE ε4 allele, and study the interaction between aluminum and ApoE ε4 allele. Methods: SH-SY5Y cells were assigned to control group, 400 μmol/L AlCl(3) group, ApoEε4 transfected group and 400 μmol/L AlCl(3) with Apo Eε4 transfected group. The cell viability was measured by CCK-8 assay; the expressions of p-tau and Aβ was determined with ELISA Kit after AlCl(3) exposure or or/and ApoE ε4 transfection. Results: The viability of cells exposed to 400 μmol/L AlCl(3) or/and ApoE ε4 transfected were significantly lower than that of controls (P<0.05) . The expressions of total tau, tau-181, tau-231, tau-396 and Aβ in 400 μmol/L Al(3)+ or/and ApoE ε4 transfected exposed cells showed significantly higher than those of controls (P<0.05) . Based on the factorial design, a significant interaction exists, and there is a synergistic effect between AlCl(3) and ApoE ε4 (P<0.05) . Conclusion: Aluminum and ApoE ε4 allele could increase expression of p-tau and Aβ deposition; there was a synergistic interaction between aluminum and ApoE ε4 allele on cell death, tau phosphorylation and Aβ deposition of SH-SY5Y.

[Effects of subchronic aluminum exposure on long-term potentiation and activities of RAS and extracellular regulated protein kinases in rats]

Objective: To study the effects of subchronic aluminum exposure on LTP and activities of RAS and ERK in rats in vivo. Methods: 24 Wistar rats were randomly divided into control group、low-dose group、medium-dose group and high-dose group, and received saline (control group) or Al (mal) (3) (15 μmol、kg、30 μmol、kg or 45 μmol/kg) via intraperitoneal injection (i.p.) for 8 weeks, respectively. The fEPSP in CA1 region were recorded by field potentiation technique in vivo and the hippocampal activities of RAS and ERK were examined by ELISA. Results: The fEPSP amplitudes of the control group were 1.90±0.19, 1.64±0.15 and 1.54±0.08 at 1, 30 and 60 min after HFS, respectively. The fEPSP amplitudes of the low-dose group were 1.40±0.06 at 60 min, which represented a statistically significant decrease compared to the control group (P<0.05) ; these values at 30min and 60min dropped to 1.33±0.20 and 1.12±0.07 in the medium-dose group (P<0.05) and further decreased to 1.05±0.05 and 0.91±0.10 in the high-dose group (P<0.05) . And the activity dose-dependent decreases were observed both in RAS and ERK: compared with the control group and the low-dose group, the activities of RAS and ERK of the medium-dose and high-dose group significantly decreased (P<0.05) and compared with the medium-dose group, the activities of the high-dose group statistically dropped (P<0.05) . Conclusion: RAS and ERK may be related to the suppression of LTP by subchronic aluminum exposure and the RAS-MAPK transduction pathway may be involved in the damage of learning and memory induced by aluminum.

[Association between serum aluminium level and methylation of amyloid precursor protein gene in workers engaged in aluminium electrolysis]

OBJECTIVE

To investigate the association between serum aluminium level and methylation of the promoter region of amyloid precursor protein (APP)gene in workers engaged in aluminium electrolysis.

METHODS

In 2012, 366 electrolysis workers in an aluminium factory were enrolled as exposure group (working years >10 and age >40 years)and divided into low-exposure group and high-exposure group based on the median serum aluminium level. Meanwhile, 102 workers in a cement plant not exposed to aluminium were enrolled as control group. Graphite furnace atomic absorption spectrometry was used to measure serum aluminium level, methylation specific PCR was used to measure the methylation rate of the promoter region of APP gene, and ELI-SA was used to measure the protein expression of APP in lymphocytes in peripheral blood.

RESULTS

The exposure group had a significantly higher serum aluminium level than the control group (45.07 μg/L vs 30.51 μg/L, P< 0.01). The exposure group had a significantly lower methylation rate of the promoter region of APP gene than the control group (18.85% vs 25.49%, P=0.025), and the high-exposure group had a significantly lower methylation rate of the promoter region of APP gene than the low-exposure group (15.84% vs 21.85%, P<0.05). The exposure group had a significantly higher protein expression of APP in lymphocytes in peripheral blood than the control group (66.73 ng/ml vs 54.17 ng/ml, P<0.05); compared with the low-exposure group (65.39 ng/ml), the high-exposure group showed an increase in the protein expression of APP in lymphocytes in peripheral blood (67.22 ng/ml), but there was no significant difference between these two groups (P>0.05). The multivariate logistic regression analysis showed that with reference to the control group, low aluminium exposure (OR=1.86, 95% CI 1.67~3.52)and high aluminium exposure (OR=2.98, 95% CI 1.97~4.15)were risk factors for a reduced methylation rate of the promoter region of APP gene.

CONCLUSION

Reduced methylation of the promoter region of APP gene may be associated with increased serum aluminium level, and downregulated methylation of the promoter region of APP gene may accelerate APP gene transcription.

[Influence of aluminum chloride exposure on embryonic development of zebrafish and neurobehavior of juvenile fish]

Objective: To investigate the influence of aluminum chloride (AlCl(3)) solution on the embryon-ic development of zebrafish and neurobehavior of juvenile fish. Methods: The embryos of zebrafishat 6 hours after fertilization were exposed to AlCl(3) solution at a concentration of 0, 55.0, 60.5, 66.6, 73.5, 80.5, or 100.0 mg/L, and embryonic hatching rates at 48 and 72 hours after fertilization were calculated. The embryos of zebrafishat 6 hours after fertilization were exposed to AlCl(3) solution at a concentration of 0, 60.0, 72.0, 86.4, 103.7, or 124.4 mg/L, and the embryonic mortality rates at 12, 24, 48, 72, and 96 hours after fertilization were calculat-ed. The embryos of zebrafish at 6 hours after fertilization were exposed to AlCl(3) solution at a concentration of 0, 50, 100, 200, 400, or 800 μg/L, and the changes in the neurobehavior of juvenile fish were observed after hatching, including touch-escape reaction at 72 hours after fertilization and autonomic movement and panic es-cape reflex at 7 days after fertilization. Results: Compared with the 0 mg/L group, the≥66.6 mg/L group had a sig-nificant reduction in embryonic hatching rate at 48 and 72 hours after fertilization, and the ≥72.0 mg/L group had a significant increase in embryonic mortality rate at 96 hours after fertilization (P<0.05) . Compared with the 0 μg/L group, the≥100 μg/L group had a significant reduction in the number of times of touch-escape reaction (P<0.05) .Compared with the 0 and 50 μg/L groups, the 100-800 μg/L groups had significant reductions in total movement distance and average speed (P<0.05) . Compared with the dark period before illumination, all groups had a significant increase in movement speed during the light period of the panic escape reflex test (i.e., the third minute) (P<0.05) ; within 2 minutes after the light was turned off, there was no significant change in movement speed in the 0-200 μg/L groups (P>0.05) ; the 400 and 800 μg/L groups had a significant increase in movement speed (P<0.05) . Conclusion: AlCl(3) exposure may cause embryonic developmental disorder in zebrafish and ab-normal neurobehavior in juvenile fish.

[Influence of occupational aluminum exposure on cognitive function and glutamate receptor protein expression in workers]

Objective: To investigate the influence of occupational aluminum exposure on cognitive function and glutamate receptor protein expression in peripheral blood lymphocytes in workers and the possibility of glutamate receptor being used as a biomarker for cognitive impairment in aluminum workers. Methods: From October to December, 2014, cluster sampling was performed to select 121 workers in aluminum electrolysis workshop as exposure group and 231 workers in thermoelectric workshop and logistics department as control group. Mini-Mental State Examination, clock drawing test, digit span test (DST) , verbal fluency test (VFT) , and Fuld Object-Memory (FOM) Evaluation were used to analyze cognitive function. Graphite furnace atomic absorption spectrophotometry was used to measure plasma aluminum level as an exposure indicator. Enzyme-linked immunosorbent assay was used to measure the content of glutamate receptor proteins in peripheral blood lymphocytes, including the subunits of N-methyl-D-aspartate receptor NR1, NR2A, and NR2B and metabotropic glutamate receptor 1 (mGluR1) . The correlation between cognitive function indices and the content of glutamate receptor proteins was analyzed. Results: There was no significant difference in plasma aluminum level between the control group and the exposure group (132.52±80.40 μg/L vs 182.88±72.32 μg/L, P>0.05) . According to the plasma aluminum level, the study subjects were divided into control group and low-, medium-, and high-level plasma aluminum groups, and there were significant differences in plasma aluminum level between these groups (all P<0.01) . The high-level plasma aluminum group had a significantly lower memory ability score than the control group and the low- and medium-level plasma aluminum groups (all P<0.05) . The high-level plasma aluminum group had lower DST and digital span forward (DSF) scores than the control group and the low-and medium-level plasma aluminum groups. The low-, medium-, and high-level plasma aluminum groups had lower digital span backward (DSB) scores than the control group. The medium-and high-level plasma aluminum groups had lower VFT scores than the control group and the low-level plasma aluminum group. The high-level plasma aluminum group had significantly lower expression of NR1 and NR2A proteins than the control group and the low-and medium-level plasma aluminum groups, and the medium- and high-level plasma aluminum groups had significantly higher expression of mGluR1 protein than the control group and the low-level plasma aluminum group (all P<0.05) . The expression of NR1 and NR2A proteins was negatively correlated with plasma aluminum level (r=-0.475 and -0.692, both P<0.05) , andthe expression of mGluR1 protein was positively correlated with plasma aluminum level (r=0.756, P<0.05) . The expression of NR1 protein was positively correlated with DSF, DSB, DST, and VFT scores (r(s)=0.213, 0.249, 0.271, and 0.228, all P<0.05) , and the expression of NR2A protein was positively correlated with VFT score (r(s)=0.206, P<0.05) . Conclusion: Occupational aluminum exposure may affect workers' memory function, and the expression of NR1 and NR2A in peripheral blood lymphocytes is correlated with cognitive function indices and can be used as biomarkers for cognitive impairment in aluminum workers.

Beneficial effects of deep sea fish oil on diabetic mice neurological injury

Deep sea fish oil mainly includes polyunsaturated fatty acid, which is usually used as health products and applied for prevention of cardiovascular and cerebrovascular diseases. However, there are only a few studies investigating the diabetes induced nerve injury till now. We established the diabetic model by using the 8-week old inbred male mice, and assumed that fish oil had a certain therapeutic effect on related neurosensory impairment and oxidative stress. Mice were divided into group A (diabetic mice induced by streptozotocin (STZ) and treated with fish oil), group B (diabetic mice) and group C (normal mice, without STZ treatment). The memory and exploration ability were evaluated and oxidation status of brain tissue was detected. Results indicated that memory and exploration ability of fish oil group A was significantly improved compared to diabetic group B (P&lt;0.05), and equal to group C. The malondialdehyde (MDA) level of fish oil group A was decreased significantly and antioxidant level was increased significantly compared to diabetic group B (P&lt;0.05), and equal to group C. In conclusion, deep sea fish oil could be used as auxiliary health care products, which plays important role in preventing and treating implications of nerve lesion impairment induced by diabetes mellitus.

[Association between H3K4me3/BDNF and the cognitive function of workers occupationally exposed to aluminum]

Objective: To investigate the influence of occupational aluminum exposure on cognitive function and its relationship with tri-methyl histone H3 lysine residues 4 points (H3K4me3) and brain-derived neurotrophic factor (BDNF) levels. Methods: By cluster random sampling method, a total of 235 cases of male workers selected from a Shanxi aluminum factory were recruited in the study in September 2015. Used the occupational epidemiological investigation questionnaire, which included Mini-Mental State Examination (MMSE) , Clock Drawing Test (CDT) , Digit Span Test (DST, including forward test DSFT and backward test DSBT) , Fuild Object Memory Evaluation (FOME) and Verbal Fluency Test (VFT) , to collect workers' basic information and assess their cognitive function score. Detected the concentration of aluminum in plasma by graphite furnace atomic absorption spectrometry. Workers were divided into three groups by the 25 percentile and 75 percentile of the aluminum content, such as low, middle and high aluminum concentration groups. The concentrations of H3K4me3 in lymphocyte and BDNF in plasma were determined by enzyme-linked immunosorbent assay. Results: The levels of aluminum in plasma was 134.36 (100.14, 178.96) μg/L. The scores of MMSE, DSFT, DSBT, DST of high aluminum concentration group were lower than low aluminum group (27.98±1.25 vs 28.83±1.54, 9.19±2.00 vs 10.64±2.87, 6.08±1.63 vs 7.19±3.07, 15.27±3.11 vs 17.81±4.72, all P<0.05) , the scores of CDT, FOME, VFT among three groups had no statistical significance (all P>0.05) . The expression levels of H3K4me3 and BDNF of high aluminum concentration group were lower than the low group [ (18.45±9.81) ng/μg Pro vs (23.76±9.89) ng/μg Pro, (26.07±10.18) ng/ml vs (31.66±9.24) ng/ml, all P<0.05]. Multiple correlation analysis showed that aluminum concentration were negatively correlated toH3K4me3, BDNF, MMSE, DSFT, DST, respectively (r(s)=-0.307、-0.214、-0.252、-0.197, -0.181, all P<0.01) . Conclusion: Exposure to occupational aluminum for a long time may change cognitive function, which go along with the decreasing of H3K4me3 level in lymphocyte and BDNF protein expression in plasma.

[Epidemiological characteristics of dyslipidemia in remote rural areas of Xinjiang, 2009-2010]

Objective: This study aimed to estimate the prevalence of dyslipidemia, hypertriglyceridemia, hypercholesterolemia, high blood low density lipoprotein cholesterol (LDL-C), and low blood high density lipoprotein cholesterol (HDL-C) in remote rural areas of Xinjiang and analyze these indicators' epidemiological characteristics. Methods: A survey of 13 000 individuals (aged ≥18 years) was conducted using a four-stage cluster random sampling method in Jiashi, Xinyuan, Aheqi, and Shawan Counties, Xinjiang, in 2009-2010. After nonpermanent residents were excluded, 12 154 individuals were included in this study. Questionnaire and physical examinations were conducted, including collection of fasting blood to detect TG, TC, LDL-C, and HDL-C. The results were calculated after complex weighting and compared according to the prevalence of different gender and age groups. Results: The overall levels of TG, TC, LDL-C, and HDL-C were 1.34±1.09, 4.45±1.16, 2.36±0.86, and 1.37±0.58 mmol/L, respectively. After complex weighting, the overall prevalence of dyslipidemia was 35.4%; that among men (42.9%) was greater than that among women (29.5%; χ²=234.19, P<0.001), and the prevalence was 35.9%, 34.5%, and 35.1% (χ²=1.52, P=0.467) in participants aged 18-44, 45-59, and ≥60 years, respectively. The overall prevalence of hypertriglyceridemia was 11.4%; that among men (13.5%) was greater than that among women (9.8%; χ²= 40.72, P<0.001), and the prevalence was 9.6%, 13.0%, and 13.2% (χ²=38.71, P<0.001) in participants aged 18-44, 45-59, and ≥60 years, respectively. The prevalence of hypercholesterolemia was 5.7%; that among men(5.0%) was greater than that among women (6.2%; χ²=6.95, P=0.008), and the prevalence was 3.5%, 7.4%, and 8.4% (χ²=105.24, P<0.001) in participants aged 18-4, 45-59, and ≥60 years, respectively. The prevalence of high blood LDL-C was 2.8%, and there was no significant difference between men (3.0%) and women (2.4%; χ²=1.43, P=0.231); the prevalence was 3.5%, 7.4%, and 8.4% (χ²=42.81, P<0.001) in participants aged 18-44, 45-59, and ≥60 years, respectively. The prevalence of low blood HDL-C was 24.0%; that among men (31.6%) was greater than that among women (18.0%; χ²=304.02, P<0.001), and the prevalence was 27.8%, 20.6% and 19.5% (χ²=96.61, P<0.001) in participants aged 18-44, 45-59, and ≥ 60 years, respectively. Conclusions: Low blood HDL-C was the main type of dyslipidemia among the population in remote rural areas of Xinjiang. The prevalence of dyslipidemia among men was greater than that among women, and there was a trend of younger men than women showing dyslipidemia.

[Association between CETP polymorphisms and haplotypes with dyslipidemia in Xinjiang Uygur and Kazak residents]

OBJECTIVE

To explore the relationship between the polymorphisms and haplotypes in the CETP gene and dyslipidemia among Xinjiang Kazak and Uygur residents.

METHODS

A population status survey was performed from 2010 to 2011 in Kashgar Xinjiang Uygur and Kazak residents, stratified cluster sampling method was used to select Uygur, Kazak residents with abnormal blood lipid values (n=367 and 345, respectively) as the dyslipidemia groups, and to select residents with normal lipid values as control group from the same area (n=374 and 390, respectively). SNaPshot technology was applied to detect the DNA of CETP gene rs3764261, rs1800775, rs708272 and rs5882 loci in all selected residents, and linkage disequilibrium analysis and haplotype construction were performed.

RESULTS

(1) In Uygur residents, the dyslipidemia risk of rs708272 CT (OR=0.64, 95%CI 0.46-0.91, P=0.01) and TT genotype (OR=0.60, 95%CI 0.40-0.91, P=0.02) was significantly lower than CC genotype. Dyslipidemia risk of rs3764261 GT (OR=0.55, 95%CI 0.40-0.74, P=0.00) and TT genotype (OR=0.47, 95%CI 0.28-0.78, P<0.01) was significantly lower than GG genetype. Dyslipidemia risk of the rs1800775 CC genotype was higher than AA genotype (OR=1.79, 95%CI 1.17-2.74, P=0.01). There was no statistical significance in CETP gene of the 4 genotype and allele frequency between the dyslipidemia and normal lipid groups in Kazak residents (all P>0.05). (2) In Uighur residents with dyslipidemia, HDL-C level was significantly higher in rs708272 TT genotype carriers than in CC and CT genotypes (all P<0.05) and in rs3764261 TT genotype carriers than in GG genotype carriers (P=0.008), while was significantly lower in rs1800775 CC genotype carriers with AA genotype carriers (P=0.008). (3) Linkage disequilibrium analysis showed that there was strong linkage disequilibrium between rs3764261 and rs708272 (D'=0.869, r(2)=0.869), rs1800775 and rs708272 (D'=0.845, r(2)=0.446) in Uighur residents, and there was strong linkage disequilibrium between rs3764261 and rs708272 (D'=0.963, r(2)=0.963), rs1800775 and rs708272 (D'=0.988, r(2)=0.630) in Kazak residents. (4) Significant differences were observed in frequency distribution of haplotype GACA(OR=0.579, 95%CI 0.388-0.864, P=0.006), GATA (OR=2.183, 95%CI 1.231-3.873, P=0.006), GCCA (OR=0.723, 95%CI 0.549-0.954, P=0.001), TATA (OR=0.723, 95%CI 0.549-0.954, P=0.021) and TATG (OR=0.601, 95%CI 0.429-0.841, P=0.002) in Uighur residents with normal or abnormal lipid profiles, while significant difference was observed in frequency distribution of haplotype GCCG (OR=1.961, 95%CI 1.207-3.188, P=0.005) in Kazak residents with normal or abnormal lipid profiles.

CONCLUSION

CETP genotype rs708272, rs3764261 and rs1800775 polymorphism is closely related to dyslipidemia and haplotype GACA, TATA and TATG will reduce the risk of dyslipidemia, while haplotype GATA, GCCA will increase the risk of dyslipidemia in Uygur residents. The four CETP polymorphisms are not related to the risk of dyslipidemia, but haplotype GCCG is related to increased risk of dyslipidemia in Kazakhs residents.

Combined promoting effects of low-Pd-containing and Cu-doped LaCoO3 perovskite supported on cordierite for the catalytic combustion of benzene

The catalytic activities for benzene oxidation and resistance to SO2 poisoning were tested for a series of Pd/La-Cu-Co-O/cordierite catalysts, which were prepared using a multiple-step impregnation method. The XRD, SEM, and IR characterization techniques were performed to investigate the relationship between the catalytic performance and its physicochemical properties. When Pd/La-Cu-Co-O/cordierite catalysts with Pd loadings of 0.06 and 0.08 % were prepared at a calcination temperature of 500 °C for 5 h, they exhibited similar catalytic activity and sulfur resistance. When the concentration of benzene was 1500 ppm and the GHSV was 20000 h(-1), the benzene conversion was above 95 % at a reaction temperature of 350 °C in SO2 existing at 100 ppm. These results were mainly attributed to the cooperation between La-Cu-Co-O perovskite and the noble metal Pd. Specifically, the addition of copper can strengthen the catalytic activity of La-Co-O/cordierite catalysts by decreasing the crystalline size of the active ingredients. A moderate Pd addition can drastically improve the sulfur resistance and further improve the catalytic activity of the La-Cu-Co-O/cordierite catalyst.

Exposure to electromagnetic fields aboard high-speed electric multiple unit trains

High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.

Clastogenic but Not Apoptotic Effects on Human Artery Endothelial Cells by Concentrations of Inorganic Lead Inhibiting Their Nitric Oxide Production

Human coronary artery endothelial cells (HCAEC 5156) were cultured as monolayers and exposed to concentrations of lead (as acetate, Pb) in the culture medium similar or lower than those commonly found in the blood of human beings occupationally or environmentally exposed to this element. Only at the concentration of 200 ng/mL, Pb reduced growth rate of HCAEC 5156 cells starting from the 3rd day and up to the 5th day of incubation. On the other hand, Pb (0.2, 2 and 200 ng/mL) increased concentration-dependently micronuclei formation in binucleated HCAEC5156 cells, as it was shown by the cytokinesis-blocked micronucleus assay (CBMN assay) carried out after 48 hours of exposure to the metal. However, Pb was unable, at all the above concentrations, to induce apoptosis in HCAEC 5156 cells following a 48 hour-exposure, as shown by an electrophoretic apoptotic DNA fragmentation test. Moreover, Pb (2 and 200 ng/mL) reduced significantly the concentration of nitric oxide (NO, determined analytically as L-citrulline) in both culture medium and cytosol of HCAEC 5156 cells following a 7 day-exposure to the element. Results were discussed also in relation to evidences of other studies reporting genotoxic and/or apoptotic effects of Pb on various cell types at very elevated dosages or concentrations. The observed clastogenic effects of Pb were explained through a series of mechanisms involving interactions between oxygen reactive species and NO and/or reduced NO synthesis in the endothelium, thus leading to a depressed NO bioavailability. This research first shows that Pb is provided with clastogenic but not apoptotic effects on cultured human endothelial cells. It was emphasized that such effects are induced by Pb concentrations similar to those commonly found in blood and tissues of laboratory animals showing Pb induced cardiovascular and/or neuropsychological alterations.

Subclinical Neurophysiological Effects of Manganese in Welding Workers

High-level occupational manganese (Mn) exposure has been reported to induce irreversible brain alterations determining a Parkinson-like disease. This study aimed to assess subclinical neurophysiological alterations in welding workers. They were employed in a machine building factory with an average Mn exposure <200 mg/m3. Sixty-eight welding workers (mean age: 34 years; mean Mn exposure duration: 16 years) and 42 flour factory workers (control group) with similar age and smoking habit were recruited. Autonomic nervous function test battery (ANSFT), composed of Valsalva maneuvre-induced heart rate variation (HR-V), heart rate variation following deep breathing (HR-DB) and heart rate variation following immediate standing up (HR-IS) was assessed. Electroencephalogram (EEG), brain electricity activity mapping (BEAM) were also performed. HR-V, HR-DB and HR-IS were significantly lower in Mn- exposed subjects showing altered autonomic nervous system activity, parasympathetic-sympathetic imbalance and, consequently, altered cardiovascular regulation and reactivity. The EEG of the Mn-exposed workers evidenced β-wave rhythms significantly reduced, Θ-waves markedly increased and abnormal wave activities of either localized or diffusive type. In the same workers, BEAM revealed higher Θ, δ and β power values in the F7 area, lower d power values in the FP1, FP2 and C4 areas as well as dissymmetry in the central area, parietal region and occipital region. This study suggests that Mn impairs neuron activity within central nervous system. In this context, brainstem parasympathetic and sympathetic centers, receiving axon projections from cortical and diencephalic areas, may reflect Mn effects on upper pathways. However, direct actions of Mn on these centers cannot be excluded.

Neurobehavioral Functions, Serum Prolactin and Plasma Renin Activity of Manganese-Exposed Workers

Objective of this study was to assess effects of manganese (Mn) exposure on 56 workers employed in a Mn welding workshop of a machine building factory in Taiyuan (Shanxi Province, P.R. China) for a mean period of 16.1 years. The mean air Mn level in the workshop was 138.4 μg/m3. Neurobehavioral Core Test Battery (NCTB), including the Profile of Mood States (POMS), was performed. Blood pressure (BP) increase following immediate stand-up (BP-IS), serum prolactin (PRL) and plasma renin activity (PRA) in supine position were also determined. Most of the NCTB scores of the Mn-exposed workers were lower than those of the controls, while the POMS scores were higher, indicating a Mn-induced impairment of neurophysiological functions and a deflection of mood towards negative emotion states. PRL values of the Mn-exposed workers were higher than those of the controls. BP-IS of Mn-exposed workers was significantly lower than that of the controls. PRA of the same workers was augmented more than 200 %. In the Mn-exposed workers, the higher PRL values are possibly due to a reduced inhibitory effect on pituitary lactotrope cells by the tubero-infundibular dopamine system; the decreased BP-IS was referred to imbalance between the sympathetic and parasympathetic activities, whereas the higher basal PRA was thought to depend on neuroendocrine changes (including increased central sympathetic tone) and/or on a direct effect of Mn on renal juxta-glomerular cells. On the whole, this study demonstrates that occupational Mn exposure is responsible for neurobehavioral changes coexisting with alterations of neuroendocrine and humoral systems.

Association of APOA1 gene polymorphisms (rs670, rs5069, and rs2070665) with dyslipidemia in the Kazakhs of Xinjiang

The aim of this study was to investigate the potential association between apolipoprotein A1 (APOA1) gene rs670, rs5069, and rs2070665 polymorphisms and dyslipidemia in the Kazakh population of Xinjiang, China. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) was used to identify APOA1 (rs670, rs5069, and rs2070665) genotypes in 736 subjects (341 dyslipidemia patients and 395 control subjects). The frequencies of the CC genotype for rs1421085 were found to be 7.2% (obese group), 4.4% (overweight group), and 5.6% (control group). Polymorphisms of the three loci of the APOA1 gene in Kazakh subjects met Hardy-Weinberg equilibrium. The frequencies of the A allele for rs670 were found to be 14.3% (dyslipidemia group) and 12.7% (control group). The frequencies of the T allele for rs5069 and rs2070665 were: dyslipidmia group (7.2 and 30.1%, respectively) and control group (7.7 and 32.5%, respectively). Frequency distributions of the 3 types of genotypes and alleles of the three loci showed no statistically significant difference (P > 0.05). Significant differences were observed in lipoprotein (α) [Lp(α)] between patients with the rs2070665 CT + TT and CC genotypes (P < 0.05); however, none of the other relevant indicators differed significantly between the two genotypes. No significant association was identified between rs670 or rs5069 and the lipid-related metabolic indices assessed in the study. These findings indicate that the polymorphisms in the APOA1 gene (rs670, rs5069, and rs2070665) are not associated with dyslipidemia in the Kazakh population assessed in this study.

[Aluminuminduced impairment in primary cultured rat choroid plexus epithelial cells]

OBJECTIVE

To investigate the impairment in primary cultured rat choroid plexus epithelial cells (CPECs)induced by aluminum.

METHODS

The choroid plexus isolated from Sprague-Dawley rats 14 days old was cut into pieces and digested by trypsin in the sterile area. The obtained single cells were cultured in DMEM with 1% epidermal growth factor and 20% fetal calf serum. Five days later, immunohistochemistry with anti-transthyretin antibody was used to identify the purity of cultured cells. The well-grown cells were treated with aluminum lactate at different concentrations (0, 100, 400, and 1 600 μmol/L for control, lowdose, mediumdose, and highdose groups). Fortyeight hours later, the cell viability, apoptotic rate, level of reactive oxygen species (ROS), and activity of superoxide dismutase (SOD)were measured in each group to evaluate the impairment in primary cultured rat CPECs by aluminum.

RESULTS

More than 95% of the cultured cells were identified as CPECs. The medium-and high-dose groups had significantly lower cell viability than the control group(86.74%±4.03% vs 100%, P<0.01; 81.90%±9.17% vs 100%, P<0.01). The high-dose group had significantly lower cell viability than the lowdose group (81.90%±9.17% vs 92.92%±8.81%, P<0.01). The medium-and high-dose groups had significantly higher apoptotic rates than the control group (7.26%±0.99% vs 1.29%±0.03%, P<0.01; 22.25%±1.55% vs 1.29%±0.03%, P<0.01)and the low-dose group (7.26%±0.99% vs 1.68%±0.27%, P<0.01; 22.25%±1.55% vs 1.68%±0.27%, P<0.01). The high-dose group had a significantly higher apoptotic rate than the medium-dose group (22.25%±1.55% vs 7.26%±0.99%, P<0.01). The mediumand high-dose groups had significantly higher fluorescence intensity of ROS than the control group (22.23%±0.41% vs 17.24%±0.09%, P<0.05; 25.10%±1.13% vs 17.24%±0.09%, P<0.05)and the lowdose group (22.23%±0.41% vs 18.31%±0.21%, P<0.05; 25.10%±1.13% vs 18.31%±0.21%, P<0.05). The highdose group had significantly higher fluorescence intensity of ROS than the mediumdose group (25.10%±1.13% vs 22.23%±0.41%, P< 0.05). The low-, medium-and high-dose groups had significantly lower SOD activity than the control group[(28.65±0.74)U/g Hb vs (37.35±1.05)U/g Hb, P<0.05; (22.75±1.94)U/g Hb vs (37.35±1.05)U/g Hb, P<0.05; (13.29±0.64)U/g Hb vs(37.35±1.05)U/g Hb, P<0.05]. The medium-and high-dose groups had significantly lower SOD activity than the low-dose group[(22.75±1.94)U/g Hb vs(28.65±0.74)U/g Hb, P<0.05; (13.29±0.64)U/g Hb vs (28.65±0.74)U/g Hb, P<0.05], while the high-dose group had had significantly lower SOD activity than the medium-dose group[(13.29±0.64)U/g Hb vs (22.75±1.94)U/g Hb, P<0.05]. There were no significant differences in cell viability, apoptotic rate, level of ROS, or activity of SOD between any other two groups (P>0.05).

CONCLUSION

Aluminum lactate may induce impairment in primary cultured rat CPECs. It reduces the cell viability, elevates the apoptotic rate, and causes oxidative stress.