Effect of pyrene-induced changes in root activity on growth of Chinese cabbage (Brassica campestris L.), and the health risks caused by pyrene in Chinese cabbage at different growth stages

Background Polycyclic aromatic hydrocarbons (PAHs) pose a potential risk to ecological safety and human health. They have a range of effects on plant growth and there have been few reports on the health risks associated with ingestion of vegetable crops at different growth stages. Methodology In this study, a pot experiment in which Chinese cabbage (Brassica campestris L.) were grown in a greenhouse for 75 days was used to investigate the dose–effect relationship of pyrene with plant growth and also the exposure risk for adults of ingestion of Chinese cabbage at different growth stages. Results The results showed that low doses of pyrene (5–45 mg kg−1) promoted plant growth (20–220% and 55–97% higher than control treatment for the root biomass and shoot biomass, respectively), but significant inhibition was observed at a high dose (405 mg kg−1) (41–66% and 43–91% lower than control treatment for the root biomass and shoot biomass, respectively). High doses of pyrene reduced soil bacterial abundance and diversity during the growth of Chinese cabbage, and increased malondialdehyde (MDA) levels in the plant. The effects of pyrene on plant biomass were mainly attributed to changes in root activity induced by pyrene, as the relationship between soil pyrene concentration and biomass was similar to that between soil pyrene concentration and root activity. Furthermore, structural equation modeling analysis showed that pyrene altered growth of the vegetable by directly affecting root activity. The incremental lifetime cancer risk for adults is highest for ingestion of Chinese cabbage at the seedling stage, followed in decreasing order by the rosette stages and heading stages. Conclusions The health risk of consumers who have the possibility to ingest the Chinese cabbage planted in pyrene-contaminated soil would be decreased with the increasing growth periods. However, further studies are required to confirm the dose–effect relationship between pyrene concentration and Chinese cabbage growth on a field scale. Graphical Abstract

Total ionizing dose effect on 2-D array data transfer ICs designed and fabricated by 0.18-µm CMOS technology

Circuits for CMOS two-dimensional (2-D) array data transfer are indispensable for applications such as space and nuclear fields. Issues include to be operated with higher speed, lower power, fewer size penalty and radiation hardness. To meet these requirements, two kinds of CMOS 2-D array data transfer circuits, such as a shift register type and a memory access type, are proposed and fabricated by the standard 0.18-µm CMOS process technology. In the both types, 16 µm pitch, 8×124 array data transfer operations were realized with data rate of more than 1 Gb/s. Furthermore, we conducted 60Co γ-ray irradiation experiments on those circuits. The current consumption ratio of the shift register type to the memory access type ranges from 150 to 200% as the dosage increases. The result indicate that the memory access type has better radiation hardness at 1 Gb/s than that of the shift register type.

Correlates of preschoolers’ screen time in China: parental factors

Background With the advent of the electronic age, the long-term screen time (ST) of preschoolers in China is relatively high and is on the rise, which is likely to affect preschoolers’ physical and mental health. This study aimed to explore the factors influencing ST in preschoolers, especially the role of parental factors, and to provide a basis for the prevention, control, and intervention of ST in preschoolers in China. Methods A questionnaire was completed by the parents of 1,546 preschoolers from four kindergartens in Pinghu City, Zhejiang Province, China, and a logistic regression model was used to analyze the correlates of excessive ST in preschoolers. Results A total of 43.8% of preschoolers, of which 50.3% were boys and 49.7% were girls, had > 1 hour/day of ST. For older preschoolers, greater screen accessibility, greater frequency of eating in front of a screen, longer ST of parents, and unclear rules of screen behavior were the risk factors for ST being > 1 hour/day (P < 0.05). After adjusting for confounders, the relationship between the ST of fathers and ST of preschoolers was still significant (P < 0.01), and the dose-effect relationship was observed (P < 0.001). Conclusion Prolonged parental ST (especially of fathers) and lack of rules for screen behavior of were independent risk factors for prolonged preschoolers’ ST in this study.

Neurotoxicity Study with Titanium Dioxide Nanoparticles on Rat

Numerous studies have shown titanium dioxide nanoparticles (TiO2 NPs) could present a risk or potential risk to humans and other living organisms in certain conditions via inhalation and skin contact. Dermal exposure has limited adverse effects and the possible risks for exogenous inhaled nanoparticles migrating to the brain through the olfactory nerve is still under research. To study the in vivo and in vitro neurotoxicity of brain tissue in rats induced by TiO2 NPs. For in vitro study, rat astrocytes were exposed to TiO2 NPs with three different diameters (10, 50 and 200 nm) at five concentrations levels. Cellular morphology and sulfur rhodamine B (SRB) were carried out to evaluate the viability of particle-treated cells after 72 hours exposure. For in vivo study, suspensions of test material above mentioned were injected into tracheas of Wistar rats at dose of 0.1, 1.0 and 10.0 mg·kg-1 in three groups, respectively. After 72 hours of exposure, the concentration of TiO2 NPs in brain tissue and the levels of IL-1β, TNF-α and IL-10 in brain homogenate were measured, while the cell morphology induced by TiO2 NPs was observed by light microscopy and transmission electron microscopy. TiO2 NPs can significantly affect the growth and morphology of rat astrocytes and inhibit the proliferation of astrocytes, which was positively related to dose-effect and size-dependent response. Pathological observations indicated that TiO2 NPs could penetrate the blood-brain barrier, leading to blood-brain barrier damage in rats, brain tissue necrosis, mitochondrial swelling and apoptosis while the non-nanoscale TiO2 particles showed no significant toxicity in the central nervous system cells.

Evaluation of Analytical Performances of Magnetic Force-Assisted Electrochemical Sandwich Immunoassay for the Quantification of Carcinoembryonic Antigen

Carcinoembryonic antigen (CEA) is a biomarker indicated in different cancers, targeted for quantitative analysis via immunoassay. Here we introduce a new technique called magnetic force-assisted electrochemical sandwich immunoassay (MESIA) for determination of CEA level in a drop of human serum using a fully automated point-of-care testing (POCT) device. The analytical performances of the assay are assessed based on precision, accuracy, limit of blank (LoB), limit of detection (LoD) and limit of quantitation (LoQ), linearity, Hook effect, interference, cross-reactivity, and method comparison following the guidelines of the Clinical Laboratory Standards Institute (CLSI). The LoD is 0.50 ng/ml. A linear relationship is shown in the range of 0.5–200 ng/ml. A high dose effect is not seen up to approximately 500,000 ng/ml. The recovery range is from 94.7 to 108.9%. The %CV of run-to-run and within-lab variations are less than 2.04 and 4.41% across the CEA concentrations, respectively, whereas reproducibility is 4.45–6.24%. Method comparison shows that the assay correlates well with the reference device (R2 = 0.9884). The assay demonstrates acceptable precision, accuracy, LoB, LoD and LoQ, hook effect, linearity, interference, cross-reactivity, and high correlation with its reference device. Thus, the system is suitable for the quantification of CEA in clinical practices with a POCT manner.

Fine Tuning of an Oxidative Stress Model with Sodium Iodate Revealed Protective Effect of NF-κB Inhibition and Sex-Specific Difference in Susceptibility of the Retinal Pigment Epithelium

Oxidative stress of the retinal pigment epithelium (RPE) is a major risk factor for age-related macular degeneration (AMD). As a dry AMD model via oxidative stress, sodium iodate (NaIO3), which is primarily toxic to the RPE, has often been used at a high dose to cause RPE death for studying photoreceptor degeneration. Thus, characterization of RPE damage by a low dose of NaIO3 is still limited. To quantify RPE damage caused by NaIO3 in mice, we recently developed a morphometric method using RPE flat-mounts. Here, we report that NaIO3 has a narrow range of dose–effect correlation at 11–18 mg/kg body weight in male C57BL/6J mice. We evaluated the usefulness of our quantification method in two experimental settings. First, we tested the effect of NF-κB inhibition on NaIO3-induced RPE damage in male C57BL/6J mice. IKKβ inhibitor BAY 651942 suppressed upregulation of NF-κB targets and protected the RPE from oxidative stress. Second, we tested sex-specific differences in NaIO3-induced RPE damage in C57BL/6J mice using a low dose near the threshold. NaIO3 caused more severe RPE damage in female mice than in male mice. These results demonstrate the usefulness of the quantification method and the importance of fine-tuning of the NaIO3 dose. The results also show the therapeutic potential of IKKβ inhibition for oxidative stress-related RPE diseases, and reveal previously-unrecognized sex-specific differences in RPE susceptibility to oxidative stress.