Polyoxometalate-Intercalated Tremella-Like CoNi-LDH Nanocomposites for Electrocatalytic Nitrite-Ammonia Conversion.

The electrocatalytic reduction of NO2- (NO2RR) holds promise as a sustainable pathway to both promoting the development of emerging NH3 economies and allowing the closing of the NOx loop. Highly efficient electrocatalysts that could facilitate this complex six-electron transfer process are urgently desired. Herein, tremella-like CoNi-LDH intercalated by cyclic polyoxometalate (POM) anion P8W48 (P8W48/CoNi-LDH) prepared by a simple two-step hydrothermal-exfoliation assembly method is proposed as an effective electrocatalyst for NO2- to NH3 conversion. The introduction of POM with excellent redox ability tremendously increased the electrocatalytic performance of CoNi-LDH in the NO2RR process, causing P8W48/CoNi-LDH to exhibit large NH3 yield of 0.369 mmol h-1 mgcat-1 and exceptionally high Faradic efficiency of 97.0% at -1.3 V vs the Ag/AgCl reference electrode in 0.1 M phosphate buffer saline (PBS, pH = 7) containing 0.1 M NO2-. Furthermore, P8W48/CoNi-LDH demonstrated excellent durability during cyclic electrolysis. This work provides a new reference for the application of POM-based nanocomposites in the electrochemical reduction of NO2- to obtain value-added NH3.

Immune Regulation Patterns in Response to Environmental Pollutant Chromate Exposure-Related Genetic Damage: A Cross-Sectional Study Applying Machine Learning Methods.

Exposure to hexavalent chromium damages genetic materials like DNA and chromosomes, further elevating cancer risk, yet research rarely focuses on related immunological mechanisms, which play an important role in the occurrence and development of cancer. We investigated the association between blood chromium (Cr) levels and genetic damage biomarkers as well as the immune regulatory mechanism involved, such as costimulatory molecules, in 120 workers exposed to chromates. Higher blood Cr levels were linearly correlated with higher genetic damage, reflected by urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and blood micronucleus frequency (MNF). Exploratory factor analysis revealed that both positive and negative immune regulation patterns were positively associated with blood Cr. Specifically, higher levels of programmed cell death protein 1 (PD-1; mediated proportion: 4.12%), programmed cell death ligand 1 (PD-L1; 5.22%), lymphocyte activation gene 3 (LAG-3; 2.11%), and their constitutive positive immune regulation pattern (5.86%) indirectly positively influenced the relationship between blood Cr and urinary 8-OHdG. NOD-like receptor family pyrin domain containing 3 (NLRP3) positively affected the association between blood Cr levels and inflammatory immunity. This study, using machine learning, investigated immune regulation and its potential role in chromate-induced genetic damage, providing insights into complex relationships and emphasizing the need for further research.

Relationships between blood chromium exposure and liver injury: Exploring the mediating role of systemic inflammation in a chromate-exposed population.

Hexavalent chromium and its compounds are prevalent pollutants, especially in the work environment, pose a significant risk for multisystem toxicity and cancers. While it is known that chromium accumulation in the liver can cause damage, the dose-response relationship between blood chromium (Cr) and liver injury, as well as the possible potential toxic mechanisms involved, remains poorly understood. To address this, we conducted a follow-up study of 590 visits from 305 participants to investigate the associations of blood Cr with biomarkers for liver injury, including serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and direct bilirubin (DBIL), and to evaluate the mediating effects of systemic inflammation. Platelet (PLT) and the platelet-to-lymphocyte ratio (PLR) were utilized as biomarkers of systemic inflammation. In the linear mixed-effects analyses, each 1-unit increase in blood Cr level was associated with estimated effect percentage increases of 0.82% (0.11%, 1.53%) in TBIL, 1.67% (0.06%, 3.28%) in DBIL, 0.73% (0.04%, 1.43%) in ALT and 2.08% (0.29%, 3.87%) in AST, respectively. Furthermore, PLT mediated 10.04%, 11.35%, and 10.77% increases in TBIL, DBIL, and ALT levels induced by chromate, respectively. In addition, PLR mediated 8.26% and 15.58% of the association between blood Cr and TBIL or ALT. These findings shed light on the mechanisms underlying blood Cr-induced liver injury, which is partly due to worsening systemic inflammation.

Simultaneous Enhancement of the Luminescence Intensity and Stability of Deep-Red CsPbI3 Perovskite Quantum Dots Achieved by a Doping Strategy.

The phase instability of CsPbI3 perovskite quantum dots (PQDs) restricts their practical applications due to the easy conversion from the luminescent cubic phase to the non-luminescent orthorhombic phase. The elemental doping route has been regarded as one of the most effective strategies to achieve high-quality PQDs-based phosphors. Herein, a stoichiometric amount of nickel chloride (NiCl2) has been effectively doped into the CsPbI3 lattice. The incorporation of Ni2+ ions has little effect on the crystal phase, structure, and morphology of the CsPbI3 PQDs but greatly influences their luminescence properties. The Ni2+ doping not only improves the luminescence performance but also greatly enhances the stability against temperature, storage time, and polar solvent. The formation process and luminescence and stability improvement mechanisms have been discussed. Moreover, the influence of a series of other metal chlorides (KCl, NaCl, MgCl2, ZnCl2, SnCl2, and CaCl2) on the luminescence performance of CsPbI3 PQDs has been systematically investigated, revealing that the luminescence intensity increases by introducing CaCl2, SnCl2, or ZnCl2 but decreases after doping MgCl2, NaCl, or KCl into the CsPbI3 lattice. The as-proposed doping strategy may have a significant impact on tackling the intrinsic instability of all-inorganic CsPbX3 PQDs, shedding light on their future applications in light-emitting diode (LED) devices and solid-state lighting.

Titanium dioxide nanoparticles: revealing the mechanisms underlying hepatotoxicity and effects in the gut microbiota.

Numerous studies in recent years have questioned the safety of oral exposure to titanium dioxide nanoparticles (TiO2 NPs). TiO2 NPs are not only likely to accumulate in the gastrointestinal tract, but they are also found to penetrate the body circulation and reach distant organs. The liver, which is considered to be a target organ for nanoparticles, is of particular concern. TiO2 NPs accumulate in the liver and cause oxidative stress and inflammatory reactions, resulting in pathological damage. The impact of TiO2 NPs on liver aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was studied using a meta-analysis. According to the findings, TiO2 NPs exposure can cause an elevation in AST and ALT levels in the blood. Furthermore, TiO2 NPs are eliminated mostly through feces, and their lengthy residence in the gut exposes them to microbiota. The gut microbiota is also dysbiotic due to titanium dioxide's antibacterial capabilities. This further leads to changes in the amount of microbiota metabolites, which can reach the liver with blood circulation and trigger hepatotoxicity through the gut-liver axis. This review examines the gut-liver axis to assess the effects of gut microbiota dysbiosis on the liver to provide suggestions for assessing the gut-hepatotoxicity of TiO2 NPs.

The modification effect of fasting blood glucose level on the associations between short-term ambient air pollution and blood lipids.

The association between short-term ambient air pollution (AAP) exposure and blood lipids is inconsistent across populations. This study aimed to investigate the modifying effects of fasting blood glucose (FBG) levels on the associations between short-term AAP exposure and blood lipids in 110,637 male participants from Beijing, China. The results showed that FBG modified the association between short-term AAP exposure and blood lipids, especially low-density lipoprotein cholesterol (LDL-C). In the hyperglycemia group, a 10-µg/m3 increase in particles with diameters ≤ 2.5 µm (PM2.5), particles with diameters ≤ 10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), or a 1-mg/m3 increase in carbon monoxide (CO) was associated with a 0.454%, 0.305%, 1.507%, 0.872%, or 3.961% increase in LDL-C, respectively. In the nonhyperglycemic group, short-term increases in air pollutants were even associated with small decreases in LDL-C. The findings demonstrate that lipids in hyperglycemic individuals are more vulnerable to short-term AAP exposure than those in normal populations.

Titanium dioxide nanoparticles induced reactive oxygen species (ROS) related changes of metabolomics signatures in human normal bronchial epithelial (BEAS-2B) cells.

Titanium dioxide often enters the respiratory tract in the form of nano-dust in occupational sites. Metabolomics may be a promising method for studying the toxicology of nano titanium dioxide. The intention of this study was to explore the possible impact of titanium dioxide nanoparticles (TiO2 NPs) on the metabolomics signatures of human normal bronchial epithelial (BEAS-2B) cells and to search for investigate the role of reactive oxygen species (ROS). In this study, BEAS-2B cells were treated by TiO2 NPs (0, 25, 50 and 100 µg/mL) for 48 h. The metabolites extracted from BEAS-2B cells were determined by untargeted metabolomics technique, and the differential metabolites and metabolic pathways were discovered by using multivariate analysis. Intracellular ROS was detected by DCFH-DA probe and flow cytometry method. Machine learning was used to explore the relationship between ROS and metabolomics changes. Totally, seventy-six differential metabolites and the steroid biosynthesis pathway of BEAS-2B cells were observed after treatment of TiO2 NPs. Lipid and lipid-like metabolites were the most significant classes among the metabolite products induced by TiO2 NPs. TiO2 NPs resulted in a dose-dependent increase in intracellular ROS levels, and correlated with most of the differential metabolites. In conclusion, TiO2 NPs increased the level of the oxidative stress, which could contribute to the altered signature represented by lipid metabolism in BEAS-2B cells.

Controllable Synthesis, Formation Process, and Luminescence Performances of Diverse Yttrium Compounds with Hollow Structures.

Hollow spherical Y2O3 and YBO3 have been prepared by a facile template-directed strategy using phenol-formaldehyde (PF) resin spheres as templates. The PF@Y(OH)CO3 precursor can be fabricated by a simple precipitation route. The Y2O3 hollow spheres are obtained via a direct annealing process, and the hollow spherical YBO3 are fabricated via a hydrothermal route followed by an annealing process at the expense of the same PF@Y(OH)CO3 precursor. The whole synthesis procedure is performed in aqueous solution without any surfactant or catalyst. Moreover, YVO4 quasi-octahedral microcrystals with spherical holes are obtained. The formation mechanisms of the yttrium compounds with different morphologies have been discussed. By incorporating proper rare earth activator ions into the Y2O3, YBO3, and YVO4 hosts, the as-synthesized luminescent materials can exhibit eminent performances with both down-conversion and up-conversion luminescence. Furthermore, the as-fabricated light-emitting diode (LED) devices can emit dazzling characteristic emission light, which reveals that the phosphors have application potential in lighting and displays. This simple synthesis strategy may provide a new idea for the fabrication of inorganic compounds with perfect hollow structures and excellent properties.

Iodine in household cooking salt no longer plays a crucial role in iodine status of residents in Tianjin, China.

PURPOSE: The contribution of household cooking salt to population iodine status is decreasing in China, the applicability of the coverage rate of iodized salt (IS), proportion of adequately iodized salt (AIS), and salt iodine concentration (SIC) of household cooking salt used for iodine status assessment of residents requires further investigation. METHODS: Through the IDD control project, 16,445 children and 4848 pregnant women were recruited from Tianjin, China and the relationship between the coverage rate of IS, proportion of AIS, SIC, and population iodine status was analyzed. Additionally, through the thyroid health survey project, 856 children with IS or noniodized salt were recruited. The effects of different household cooking salts on individual iodine status and thyroid health were analyzed. RESULTS: After adjusting for confounding factors, no relationship was found between the coverage rate of IS, proportion of AIS, SIC of household cooking salt, and iodine status of children and pregnant women (all P > 0.05). No differences in levels of thyroid function and structural indicators were found in children with different household cooking salts (all P > 0.05). Additionally, no relationship was found between noniodized salt exposure and goiter, overt hyperthyroidism, overt hypothyroidism, thyroid nodules, antibody single positivity, or subclinical hypothyroidism (all P > 0.05). CONCLUSION: Iodine in household cooking salt no longer plays a crucial role in iodine status in Tianjin, China. Other indicators must be identified as beneficial supplements for precise iodine status evaluation not only in Tianjin but also in other large cities in China.

Spin Hall effect of transmitted light through α-Li3N-type topological semimetals.

The spin Hall effect of light occurring in topological semimetals provides unprecedented opportunities to exploit novel photonic properties and applications. In particular, pristine α-Li3N-type crystal has recently been predicted to be a type-I nodal-line semimetal based on density functional theory. Herein, the spin Hall effect of transmitted light through thin films of α-Li3N-type topological semimetals is investigated. We show that the prominent intense peak and dip emerging in the spectra of spin Hall shifts occur at the high-energy side of interband absorption of α-Li3N-type semimetals and show redshifts with increasing the incident angle or permittivity of the exit medium. In addition, type-I nodal-line semimetal under a compressive lattice strain is transformed into a type-II one such that the main intense peak and dip show blueshifts. Inversely, the tensile strain induces the formation of a triply degenerate nodal point in α-Li3N-type semimetals, causing the main intense peak and dip to show redshifts. Moreover, the influences of alloying and hole-doping in α-Li3N-type semimetals on the spin Hall effect of light are also discussed. Our findings may provide clear strategies to accurately engineer and detect the structural or phase change in topological materials.

Association between ambient air pollution and blood sex hormones levels in men.

Concerns are growing over time on the adverse health effects of air pollution. However, the association between ambient air pollution and blood sex hormones in men is poorly understood. We included 72,917 men aged 20-55 years from February 2014 to December 2019 in Beijing, China in this study. Blood testosterone, follicle stimulating hormone, luteinizing hormone, estradiol, and prolactin levels of each participant were measured. We collected exposure data of daily ambient levels of particulate matter ≤10 µm (PM10) and ≤2.5 µm (PM2.5), nitrogen dioxide, sulfur dioxide (SO2), carbon monoxide, and ozone. Generalized linear mixed models were used to analyze the potential association between ambient air pollution exposure and blood sex hormone levels. The results showed that both immediate and short-term cumulative PM2.5, PM10, and SO2 exposure was related to altered serum sex hormone levels in men, especially testosterone. An increase of 10 µg/m3 in PM2.5 and PM10 in the current day was related to a 1.6% (95% confidence interval [CI]: 0.9%-2.3%) and 1.1% (95% CI: 0.5%-1.6%) decrease in testosterone, respectively, and a decreasing tendency of accumulated effects persisted within lag 0-30 days. The present study demonstrated that it is important to control ambient air pollution exposure to reduce effects on the reproductive health of men.

Landscape of lipidomic metabolites in gut-liver axis of Sprague-Dawley rats after oral exposure to titanium dioxide nanoparticles.

BACKGROUND: The application of titanium dioxide nanoparticles (TiO2 NPs) as food additives poses a risk of oral exposure that may lead to adverse health effects. Even though the substantial evidence supported liver as the target organ of TiO2 NPs via oral exposure, the mechanism of liver toxicity remains largely unknown. Since the liver is a key organ for lipid metabolism, this study focused on the landscape of lipidomic metabolites in gut-liver axis of Sprague Dawley (SD) rats exposed to TiO2 NPs at 0, 2, 10, 50 mg/kg body weight per day for 90 days. RESULTS: TiO2 NPs (50 mg/kg) caused slight hepatotoxicity and changed lipidomic signatures of main organs or systems in the gut-liver axis including liver, serum and gut. The cluster profile from the above biological samples all pointed to the same key metabolic pathway and metabolites, which was glycerophospholipid metabolism and Phosphatidylcholines (PCs), respectively. In addition, absolute quantitative lipidomics verified the changes of three PCs concentrations, including PC (16:0/20:1), PC (18:0/18:0) and PC (18:2/20:2) in the serum samples after treatment of TiO2 NPs (50 mg/kg). The contents of malondialdehyde (MDA) in serum and liver increased significantly, which were positively correlated with most differential lipophilic metabolites. CONCLUSIONS: The gut was presumed to be the original site of oxidative stress and disorder of lipid metabolism, which resulted in hepatotoxicity through the gut-liver axis. Lipid peroxidation may be the initial step of lipid metabolism disorder induced by TiO2 NPs. Most nanomaterials (NMs) have oxidation induction and antibacterial properties, so the toxic pathway revealed in the present study may be primary and universal.

Perspectives of Genetic Damage and Epigenetic Alterations by Hexavalent Chromium: Time Evolution Based on a Bibliometric Analysis.

Compounds containing hexavalent chromium [Cr(VI)] have been classified as Group I human carcinogens in 1990 by the International Agency for Research on Cancer, known to induce human lung cancers. To determine the nature of Cr(VI) carcinogenesis, much has been learned about genetic damage and epigenetic alterations. On the basis of bibliometric analysis of the available literature found between 1966 and 2020, the present study investigated the evolution of author keywords; provided a summary of relevant studies focused on populations, animals/plants, or cells; and depicted the co-operation among countries or institutions and research group development. Additionally, multiomics technology and bioinformatics analysis can be a valuable tool for figuring out new biomarkers from different molecular levels like gene, RNA, protein, and metabolite and ascertaining the mechanism pathways of Cr(VI) genotoxicity and carcinogenesis.

Pharmacokinetics and safety of pegylated recombinant human granulocyte colony-stimulating factor in children with acute leukaemia.

AIMS: This open-label, phase I study evaluated the pharmacokinetics and safety of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) for the treatment of chemotherapy-induced neutropenia in children with acute leukaemia. METHODS: PEG-rhG-CSF was administered as a single 100 mcg/kg (3 mg maximum dose) subcutaneous injection at the end of each chemotherapy period when neutropenia occurred. Blood samples were obtained from patients treated with PEG-rhG-CSF. PEG-rhG-CSF serum concentrations were determined by an enzyme-linked immunosorbent assay. Population pharmacokinetic (PPK) analysis was implemented using the nonlinear mixed-effects model. Short-term safety was evaluated through adverse events collection (registered at clinicaltrials.gov identifier: 03844360). RESULTS: A total of 16 acute leukaemia patients (1.8-13.6 years) were included, of whom two (12.5%) had grade 3 neutropenia, six (37.5%) had grade 4 neutropenia, and eight (50.0%) had severe neutropenia. For PPK modelling, 64 PEG-rhG-CSF serum concentrations were obtainable. A one-compartment model with first-order elimination was used for pharmacokinetic data modelling. The current weight was a significant covariate. The median (range) of clearance (CL) and area under the serum concentration-time curve (AUC) were 5.65 (1.49-14.45) mL/h/kg and 16514.75 (6632.45-54423.30) ng·h/mL, respectively. Bone pain, pyrexia, anaphylaxis and nephrotoxicity were not observed. One patient died 13 days after administration, and the objective assessment of causality was that an association with PEG-rhG-CSF was "possible". CONCLUSIONS: The AUC of PEG-rhG-CSF (100 mcg/kg, 3 mg maximum dose) in paediatric patients with acute leukaemia were similar to those of PEG-rhG-CSF (100 mcg/kg) in children with sarcoma. PEG-rhG-CSF is safe, representing an important therapeutic option for chemotherapy-induced neutropenia in paediatric patients with acute leukaemia.

Nonlinear THz radiation investigated by quantum simulations.

Terahertz (THz) waves can be generated by the nonlinear interaction between ultrashort laser pulses and air. The semiclassical photocurrent model is widely used. It is simple, but neglects the quantum effects. Some theoretical works are based on solving the time-dependent Schrödinger equation. However, it meets the difficulty of prohibitively large boxes in long-time evolution. Here we adopted the wave-function splitting algorithm to fully contain the information of photoelectrons. The contributions of the excited states and interference effects in electron wavepackets to THz radiation are studied numerically. We also theoretically investigated the THz generation from nitrogen molecules in a biased electric field. It is found that the THz yield enhancement as a function of the static field strength in experiments can be reproduced well by our method. In addition, the restriction of wavelength and phase difference in the two-color laser fields is less strict in the presence of the static field.

Alterations to cardiac morphology and function among high-altitude workers: a retrospective cohort study.

OBJECTIVES: Exposure to high altitude can affect human health, including the development of adverse cardiovascular effects. This study aimed to investigate alterations in cardiac morphology and function in high-altitude workers and to identify risk factors associated with cardiac abnormalities. METHODS: A retrospective cohort study was conducted with 286 Qinghai-Tibetan Railroad maintenance workers. Participant data were collected from company personnel records. Data on echocardiography and diagnosis of cardiac abnormalities were extracted from participants' medical records. Time-to-event analysis was used to investigate the risk of cardiac abnormalities among participants with different baseline characteristics and identify risk factors associated with cardiac abnormalities that developed as a result of working at high altitude. RESULTS: A total of 173 participants had developed cardiac abnormalities during the follow-up period. The most common cardiac abnormality was right atrial enlargement, followed by left ventricular diastolic dysfunction and tricuspid regurgitation. Among participants with cardiac abnormalities, the median follow-up time was 17 months. Compared with participants who were younger than 20 years and working at altitude <4000 m, participants older at employment and working at extremely high altitude were more likely to develop cardiac abnormalities. Nearly 40% of the participants who worked at altitude <4000 m remained without cardiac abnormalities during the follow-up period. CONCLUSIONS: Over 60% of participants developed cardiac abnormalities after working at high altitude, predominantly right heart enlargement and left ventricular diastolic dysfunction. Age at employment and workplace altitude were significant risk factors for cardiac abnormalities. Enhanced regular physical examinations are recommended for high-altitude workers.

Combined effect of titanium dioxide nanoparticles and glucose on the blood glucose homeostasis in young rats after oral administration.

Titanium dioxide nanoparticles (TiO2 NPs) were usually consumed with a high content of sugar, and children were identified as having the highest exposures due to sweet food preferences. Research on the combined effect of ingested TiO2 NPs and glucose has great significance, particularly in young people. We examined young Sprague-Dawley rats administered TiO2 NPs (0, 2, 10 and 50 mg/kg) orally with and without glucose (1.8 g/kg) for 90 days. Blood glucose homeostasis was assessed by monitoring blood glucose and detecting glycoproteins. Glucose tolerance was also evaluated by the oral glucose tolerance test. The levels of blood glucose-related hormones such as insulin, C-peptide and glucagon were measured. We found that subchronic co-exposure of TiO2 NPs and glucose caused slight imbalance of blood glucose homeostasis in vivo. Mild and temporary hypoglycemia, impaired glucose tolerance and changes of glucose-regulating hormones were shown in the exposure groups. The combined effect of TiO2 NPs and glucose was more apparent than that of TiO2 NPs alone, which may be due to the effects of excess glucose and the interactions between TiO2 NPs and glucose. The antagonistic effect of TiO2 NPs with glucose did exist in the level of glycosylated hemoglobin in female rats. Gender differences were apparent in these effects induced by TiO2 NPs and glucose. Female rats seemed to be more susceptible for blood glucose disorders. Co-exposure of TiO2 NPs and excessive glucose could induce gender-dependent imbalance of blood glucose homeostasis in rats. It may be the reason that these consumers face greater health risks glycosylated hemoglobin.

[Effect of subacute combined oral exposure of titanium dioxide nanoparticles and glucose on blood glucose homeostasis in young SD rats].

OBJECTIVE: To explore the effect of combined oral exposure of titanium dioxide nanoparticles(TiO_2 NPs) and glucose on blood glucose homeostasis in young SD rats. METHODS: Eighty 4-week-old young SD rats were randomly divided into 8 groups(10 rats in each group, half male and half female). The rats were exposed to TiO_2 NPs through intragastric administration at 0, 2, 10 and 50 mg/kg with or without 1. 8 g/kg glucose daily for 30 days. Blood glucose was monitored weekly during the experiment. Oral glucose tolerance test(OGTT) was carried out after subacute exposure(30 days), and the biomarkers related to blood glucose homeostasis were detected, including the contents of glycosylated serum protein(GSP), glycosylated hemoglobin(HbA1 c), insulin, C-peptide and glucagon. At the same time, the pancreatic pathology of rats was observed. RESULTS: TiO_2 NPs were anatase crystals, closely spherical shape, with an average particle size of(24±5)nm. Exposure of TiO_2 NPs alone had little effect on blood glucose homeostasis. Blood glucose decreased on the 16 th exposure day at dose of 10 mg/kg TiO_2 NPs, and postprandial blood glucose(2 h) decreased after 30 days of TiO_2 NPs exposure at doses of 2 and 50 mg/kg in male rats(P<0. 05). The combined effect of oral exposure of TiO_2 NPs and glucose on blood glucose homeostasis was more obvious than that of TiO_2 NPs alone. Blood glucose decreased on the 9 th exposure day at dose of 10 mg/kg TiO_2 NPs+glucose in female rats, and postprandial blood glucose(2 h) decreased at dose of 2 and 50 mg/kg TiO_2 NPs+glucose after 30 days of exposure in male rats(P<0. 05). Blood glucose decreased on the 9 th day after 10 mg/kg TiO_2 NPs+glucose exposure in female rats. The glycosylated serum protein decreased and postprandial blood glucose(30 and 60 min) as well as the area under curve of OGTT increased in male rats after 30 days of exposure(P<0. 05). The changes of blood glucose-regulating hormones were only found after the combined exposure of 10 mg/kg TiO_2 NPs+glucose for 30 days, including the decrease of insulin in female rats, as well as the decrease of insulin and the increase of glucagon in male rats(P<0. 05). The interaction analysis showed that TiO_2 NPs and glucose had significant synergistic effect on postprandial blood glucose(60 min) in male rats(P<0. 05). No abnormality was found in the pathological observation of pancreas in rats of experimental groups. CONCLUSION: Subacute combined oral exposure of TiO_2 NPs and glucose could affect the blood glucose homeostasis of young SD rats, resultsing in temporary hypoglycemia and impaired glucose tolerance, as well as adaptive changes of blood glucose-regulating hormones. The male rats were more sensitive. Compared with the exposure of TiO_2 NPs alone, the combined exposure of TiO_2 NPs and glucose induced more significant effects. Significant synergistic effect between them occurred on postprandial blood glucose.

Association of low-level blood lead with serum uric acid in U.S. adolescents: a cross-sectional study.

BACKGROUND: Uncertainty remains regarding the association between blood lead levels (BLL) and serum uric acid (SUA) with relatively low BLL exposure because of limited data in the adolescent population. We examined the association between BLL and SUA in U.S. adolescents. METHODS: In this cross-sectional study, 8303 adolescents aged 12-19 years from NHANES 1999-2006 were analyzed. BLL was Ln-transformed for analysis for the skewed distribution. Elevated SUA was defined as ≥5.5 mg/dL. Multivariate linear and multiple logistic regression analyses were performed to evaluate the association of BLL with SUA and elevated SUA. Moreover, a generalized additive model (GAM) and a fitted smoothing curve (penalized spline method) were conducted. RESULTS: The overall mean BLL was 1.3 µg/dL. Multivariate linear regression analyses showed that LnBLL was independently and positively correlated with SUA level (ß = 0.13, 95%CI: 0.09-0.17). Multiple logistic analyses showed that LnBLL was associated with a 24% increased prevalence of elevated SUA (OR = 1.24; 95% CI, 1.11-1.38). Analyses using restricted cubic spline confirmed that the associations of LnBLL with SUA and elevated SUA were linear. Subgroup analyses showed that stronger associations between LnBLL and SUA were detected in adolescents with lower levels of education and estimated glomerular filtration rate (eGFR) (all P for interaction < 0.05). CONCLUSIONS: BLL was independently and positively correlated with SUA level and elevated SUA among U.S. adolescents, particularly with lower levels of education and eGFR. The data suggest that there is no "safe" threshold level of exposure to lead.

Hepatotoxicity and the role of the gut-liver axis in rats after oral administration of titanium dioxide nanoparticles.

BACKGROUND: Due to its excellent physicochemical properties and wide applications in consumer goods, titanium dioxide nanoparticles (TiO2 NPs) have been increasingly exposed to the environment and the public. However, the health effects of oral exposure of TiO2 NPs are still controversial. This study aimed to illustrate the hepatotoxicity induced by TiO2 NPs and the underlying mechanisms. Rats were administered with TiO2 NPs (29 nm) orally at exposure doses of 0, 2, 10, 50 mg/kg daily for 90 days. Changes in the gut microbiota and hepatic metabolomics were analyzed to explore the role of the gut-liver axis in the hepatotoxicity induced by TiO2 NPs. RESULTS: TiO2 NPs caused slight hepatotoxicity, including clear mitochondrial swelling, after subchronic oral exposure at 50 mg/kg. Liver metabolomics analysis showed that 29 metabolites and two metabolic pathways changed significantly in exposed rats. Glutamate, glutamine, and glutathione were the key metabolites leading the generation of energy-related metabolic disorders and imbalance of oxidation/antioxidation. 16S rDNA sequencing analysis showed that the diversity of gut microbiota in rats increased in a dose-dependent manner. The abundance of Lactobacillus_reuteri increased and the abundance of Romboutsia decreased significantly in feces of TiO2 NPs-exposed rats, leading to changes of metabolic function of gut microbiota. Lipopolysaccharides (LPS) produced by gut microbiota increased significantly, which may be a key factor in the subsequent liver effects. CONCLUSIONS: TiO2 NPs could induce slight hepatotoxicity at dose of 50 mg/kg after long-term oral exposure. The indirect pathway of the gut-liver axis, linking liver metabolism and gut microbiota, played an important role in the underlying mechanisms.