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Metallic materials have attracted the considerable attentions owing to their remarkable tribological potentials, rendering them indispensable in the fields of manufacturing, aerospace, medical, and daily life. In the future, their utilization is poised to extend into electronic devices, energy storage, sensors, catalysts and other realms in order to enhance performance metrics, bolster stability and reduce costs. Notwithstanding various research have been undertaken on metal-based composites, the important influencing factors and wear mechanisms of metal-base friction interfaces have not been comprehensively reviewed. Therefore, this review summarizes these main influencing factors (e.g., material properties, service conditions, additives and energy effects) on tribological behaviors of metal interfaces, subsequently generalizes their wear mechanisms such as abrasion, adhesion, corrosion and fatigue. Finally, their development prospects and difficulties of the interface tribology are discussed in detail, thereby providing the in-depth insight of these fields for enriching actual applications. [ABSTRACT FROM AUTHOR]

Abstract Background Few epidemiological studies have investigated associations of exposure to multiple metals with thyroid hormone homeostasis, especially for the pregnant women. Methods Among all the 1644 participants enrolled in Hangzhou Birth Cohort Study (HBCS) at baseline, a total of 915 pregnant women with complete data of interest were analyzed. Eleven metals were measured in blood samples collected around 25 weeks gestation. Serum levels of thyroid hormones including free triiodothyronine (FT3), total triiodothyronine (TT3), free thyroxine (FT4), total thyroxine (TT4) and thyroid-stimulating hormone (TSH) were abstracted from the medical records. Relationships between tertiles of metal levels (setting the lowest tertile as the reference) and percent changes in thyroid hormones were estimated by multivariable adjusted linear regression models. Results Five metals [arsenic (As), selenium (Se), manganese (Mn), nickel (Ni), antimony (Sb)] were significantly linked to decreased levels of one or more thyroid hormones based on trend tests in the single-metal models. Percent changes [95% confidence intervals (CIs)] in thyroid hormones for the third tertiles of metals remained significant between FT3 and As [−3.53% (−5.48%, −1.54%)]; and between TT3 and As [−4.19% (−7.00%, −1.31%)]; and between FT4 and Mn [−2.05% (−3.49%, −0.58%)], Sb [−1.99% (−3.44%, −0.52%)] in the multiple-metal models. Conclusions Thyroid hormone concentrations were reversely related to the levels of blood metals of As, Mn and Sb among Chinese pregnant women. Additional prospective studies are warranted to confirm the causality. Paper capsule: Exposure to multiple metals was reversely associated with one or more thyroid hormones in the Chinese pregnant women. Graphical abstract Unlabelled Image Highlights • Associations of multiple metals with thyroid hormones were examined at pregnancy. • Both single- and multiple-metal models were employed for data analyses. • Blood metals of As, Mn and Sb were reversely linked to thyroid hormones. [ABSTRACT FROM AUTHOR]

A fast and accurate method for ultrasensitive monitoring of substrate is significant for cascade molecular detection. Here, we synthesize a glucose oxidase (GOx) microgel with iron coordination (Fe/GOx microgel). The microgel is cross-linked by chitosan and iron ion coordination which construct a tubular structure. Powder X-ray diffraction and Brunauer-Emmett-Teller results confirm the tubular crystal structure with a high specific surface area is formed in the microgel. The tubular structure offers a stable channel for intermediate transport which ensures the stabilization for the intermediate transport, and high specific surface area enhances the interaction between substrates and catalysts. As a result, the sensitivity of the Fe/GOx microgel is 175.5 μA mM−1 cm−2 and the lowest detection limit is 4.42 μM. In addition, the nanoscale Fe/GOx microgel also has the characteristics of reusability and maintains its activity after five times of catalysis. The generation of free radicals during the catalytic process can be detected by light detection and electrochemical signal detection within different detection limits. Therefore, Fe/GOx microgel provides a new platform and catalyst for the precise detection of cascade catalysis. [ABSTRACT FROM AUTHOR]

To evaluate the body burdens of heavy metals and explore the impact of environmental metal exposure on ribosomal DNA (rDNA) or mitochondrial DNA (mtDNA) copy number (CN) variation in school-age children living near a municipal waste incinerator (MWI), we conducted a follow-up study in 2019. A total of 146 sixth-grade children from a primary school located 1.2 km away from the MWI were recruited for our study. Metals, including vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), stannum (Sn), stibium (Sb), thallium (Tl), and lead (Pb), were determined by an inductively coupled plasma mass spectrometer method. Real-time qPCR was used to measure the rDNA and mtDNA CN. The blood metal levels followed this order: Zn > Cu > Se > Pb > Mn > Sb > As > Ni > Cd > Co > Cr > Sn > V > Tl. Blood Cr level was significantly correlated with 18 S, 2.5 S, and 45 S CN (β = −0.25, −0.22, −0.26, p < 0.05); Ni was correlated with 5 S (β = −0.36, p < 0.01); Cu was correlated with 28 S, 18 S, and 5.8 S (β = −0.24, −0.24, −0.23, p < 0.05); while Zn was correlated with 18 S, 5.8 S, and 45 S (β = −0.28, −0.32, −0.26, p < 0.05). In conclusion, school-age children living near the MWI had lower blood metal levels compared to children recruited in 2013, while rDNA CN loss was found to be correlated to several heavy metals in these children. [Display omitted] • Children living around MWIs may not suffer considerable long-term accumulation of heavy metals. • Blood Cr was correlated with 18 S, 2.5 S, and 45 S CN. • Blood Cu was correlated with 28 S, 18 S, and 5.8 S CN. • Blood Zn was correlated with 18 S, 5.8 S, and 45 S CN. [ABSTRACT FROM AUTHOR]

• Associations of metals with testosterone and hemoglobin was examined in pregnant. • Blood Pb level was associated with testosterone, RBC, hemoglobin and hematocrit. • Testosterone may mediate the association between Pb and erythropoietic parameters. Few epidemiological studies have investigated associations of exposure to multiple metals with testosterone homeostasis and erythropoiesis, especially for the pregnant women. Among all the 1644 participants enrolled in Hangzhou Birth Cohort Study (HBCS) at baseline, a total of 918 pregnant women with complete data of interest were analyzed. The whole blood metals levels were examined by inductively coupled plasma mass spectrometry (ICP-MS), and serum testosterone level was evaluated by chemiluminescent microparticle immunoassay (CMIA), and erythropoietic parameters values were extracted from medical record. Multivariable linear regression models were applied to estimate the relationships between metals levels and testosterone level, and between metals levels and erythropoietic parameters, and potential confounders were adjusted. Single metal model analysis revealed a significant association of blood As, Mn and Pb level with serum testosterone level. After controlling for multiple testing, the dose-response trend with statistical significance (FDR-adjusted p trend <0.05) was observed across tertiles of Pb with testosterone. This association, when by stratified by gender, remained in pregnant women with a male fetus but did not reach significant in those with a female fetus. Furthermore, blood Pb level was positively associated with red blood cell counts, hemoglobin level and hematocrit. Serum testosterone level was positively associated with red blood cell counts, hemoglobin level and hematocrit. Mediation analyses indicated that testosterone might act as a mediator in the association between Pb exposure and erythropoietic parameters. Serum testosterone level and hemoglobin level was positively related to blood Pb level among Chinese pregnant women, and testosterone might mediate the effect of Pb exposure on hemoglobin. Additional prospective studies are warranted to confirm the causality. [ABSTRACT FROM AUTHOR]