Search

Mesotrione, topramezone, tembotrione, and sulcotrione are four types of 4-hydroxyphenylpyruvate dioxidase (HPPD) inhibitor herbicides that are extensively employed in agricultural practices, but their usage also leads to environmental pollution and poses risks to human health. A probe (E)−1-((2-(pyridin-2-yl) hydrazineylidene) methyl) naphthalen-2-ol (CHMN) based on chelation enhancement (CHEF) effect synthesized. CHMN was first chelated with Zn2+ to form a probe system with green, which can be further used to detect mesotrione, topramezone, tembotrione and sulcotrione in complicated environment. CHMN-Zn2+ detection of four pesticides was accurate, with an excellent linear relationship between 0 and 100 μM. The detection limits were LOD mesotrione = 7.79 μM, LOD topramezone = 1.91 μM, LOD tembotrione = 1.38 μM and LOD sulcotrione = 2.43 μM. The detection time is 1 min, and it is successfully applied in real water sample and bioimaging. This work can provide a novel method for studying the migration and behavior of environmental pollutants. [Display omitted] • A novel Zn2+-coordination fluorescent probe for sensing HPPD inhibitors was synthesized. • CHMN has low cytotoxicity, high sensitivity and and good selectivity. • CHMN can detect HPPD inhibitors in environmental water samples. • CHMN can visualize the migration and behavior of HPPD inhibitors in vivo in real time. [ABSTRACT FROM AUTHOR]

Understanding the physiological effects of herbicides on crops is crucial for crop production and environmental management. The effects of 4-hydroxyphenylpyruvate dioxygenase inhibitor (HPPDi) herbicides at different concentrations on chlorophyll content in maize leaves, fresh weight of roots, stems and leaves, and fluorescence substances and functional groups in root exudates (REs) were studied by UV-Vis absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) and two-dimensional correlation analysis (2D-COS). The results showed that 5 mg/L and 10 mg/L HPPDi herbicides inhibited the synthesis of chlorophyll in maize leaves. The weight of roots, stems and leaves of maize after application was lighter than that of the control group. HPPDi herbicides affected the early growth of maize seedlings, and the effect was most obvious at high concentration. Synchronous fluorescence spectrum and three-dimensional (3D) fluorescence spectrum revealed that the fluorescence intensity of protein, fulvic acid and humic acid in maize REs changed prominently. With the increase of HPPDi herbicides concentration, the fluorescence intensity decreased gradually. Through FTIR and 2D-COS, functional groups such as C-H, C O, Cl, NO 3 -, C-O and O-H were found to participate in the interaction between HPPDi herbicides and maize REs as binding sites. C-O, C-Cl and C-C have the strongest binding ability, while C C and C O of aromatic rings, quinones or ketones first take part in the binding between HPPDi herbicides and maize REs. The results can provide a theoretical basis for evaluating the safety of HPPDi herbicides on maize and a method for discovering the effects of pesticides on environmental media and plant physiological effects. [Display omitted] • 5 mg/L and 10 mg/L HPPDi inhibited the synthesis of chlorophyll in maize leaves. • HPPDi affected the fresh weight of maize roots, stems and leaves. • HPPDi reduced the fluorescence intensity of protein, FA and HA in REs. • REs bind to HPPDi through C-H, C O, Cl, NO 3 -, C-O and O-H. [ABSTRACT FROM AUTHOR]

Eutrophication of lacustrine environments with frequent cyanobacterial blooms has become a serious problem. Overpopulation and runoff into groundwater and lakes from fertilizers with too much nitrogen and phosphorous have caused most of the problems. Here, we first devised a land use and cover classification system based on the local characteristics of the first-level protected area of Lake Chaohu (FPALC). Lake Chaohu is the fifth largest freshwater lake in China. The land use and cover change (LUCC) products were produced using sub-meter resolution satellite data from 2019 to 2021 in the FPALC. This study presents an evaluation of the effectiveness of the established protected areas. The results show the most impactful type was the reduction in cropland with an area that declined from 7446.4 hm2 to 6433.3 hm2 from 2019 to 2021. Most of the reduced cropland was converted into wetlands, with 460.2 hm2 and 152.0 hm2 of cropland restored to wetlands from 2019 to 2020 and 2020–2021, respectively. The area of cyanobacterial blooms in Lake Chaohu showed a downward trend, and the lacustrine environment was greatly improved after the establishment of the FPALC. These quantified data can inform decision-making related to Lake Chaohu conservation and provide a reference for managing the aquatic environment in other watersheds. [Display omitted] • Watershed LUCC was mapped using very high-resolution satellite data (∼0.5 m). • A new LUCC classification system is designed for protected area. • LUCC trends and underlying drivers in the protected area were quantified. • The effect of protected area on lacustrine environments was evaluated. • The establishment of FPALC improved the lacustrine environment. [ABSTRACT FROM AUTHOR]

Infertility affects about 10–15% couples over the world, among which a large number of cases the underlying causes are still unclear. Recent studies suggest that environmental factors may play an important role in these idiopathic infertilities. Arsenic is a heavy metal found in drinking water over the world. Its effect on the development of female reproductive system at the environmental-relevant levels is still largely unknown. To test the hypothesis that arsenic exposure during juvenile and puberty may affect sex maturation and female reproductive system development, SD rats of 3 weeks of age were exposed to arsenic with environmental-relevant levels (0, 0.02, 0.2, or 2 mg/L, n = 16/group) through drinking water for about 44 days until the rats reached adulthood (65 days of age). Arsenic exposure significantly reduced the weights of both ovary and uterus without affecting the body weight. Also, arsenic exposure disturbed estrus cycles and reduced the numbers of primordial follicles and corpora lutea while increased atretic follicles. In addition, arsenic reduced serum levels of estradiol, progesterone and testosterone but increased LH and FSH levels in dose-dependent manners. QPCR and Western blot experiments indicated arsenic selectively down-regulated ovarian steroidogenic-related proteins FSHR, STAR, CYP17A1, HSD3B1 and CYP19A1 and signaling molecules PKA-ERK-JNK-cJUN, without affecting AKT and CREB. As about reproductive capacity, arsenic-exposed dams had smaller pups, reduced litter size and lower number of male pups without a change in female pups. In conclusion, juvenile and pubertal arsenic exposures at environmental-relevant levels significantly reduced reproductive functions and capacity by adult. Since the lowest effective dose is very close to the government safety standards, the relevancy of arsenic over exposure to reproductive defects in human deserves further study. [Display omitted] • Pubertal arsenic exposure significantly disturbed the estrous cycles by adult. • Arsenic affected the numbers of primordial and atretic follicles and corpora lutea. • Arsenic reduced serum levels of E2, P4 and T but increased the levels of LH and FSH. • Arsenic down-regulated steroidogenic proteins STAR, HSD3B1, CYP17A1 and CYP19A1. • Arsenic reduced pup weights, litter size and changed the sex-ratio of the offspring. [ABSTRACT FROM AUTHOR]

4-Hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor is one of the important herbicides to solve the problem of weed control. With the widespread and continued use of HPPD inhibitor (HPPDi) herbicides, it may inevitably put pressure on the environment. Humic acid (HA) can effectively interact with pesticides through sorption or covalent bond formation and promote the degradation of pesticides, which can reduce the risk of pesticides in the environment. In the present study, the interactions of four HPPDi herbicides (sulcotrione, tembotrione, topramezone and mesotrione) with HA were reported and comparative assessment of the binding using multispectral technology, density functional theory (DFT) calculation and two-dimensional correlation spectroscopy (2D-COS). Time-resolved measurements and the Stern-Volmer constant at different temperature verified that HPPDi can bind with HA through the static quenching mechanism. From the thermodynamic parameters, the interaction force between HA and sulcotrione, tembotrione, topramezone and mesotrione was provided by electrostatic force. DFT, binding constant and three-dimensional (3D) fluorescence peak variation all indicated that the order of the binding ability of the four HPPDi and HA was mesotrione > tembotrione > sulcotrione > topramezone. According to dynamic light scattering (DLS), pH 7 is most conducive to the formation of HA-HPPDi complexes. Fourier transform infrared spectroscopy (FTIR) and 2D-COS showed that HA combined with HPPDi through aromatic C-H, C O and C-X, and the first binding group to HA was almost all C O. Sulcotrione, tembotrione, topramezone and mesotrione quench the endogenous fluorescence of HA by a static quenching mechanism and bind to HA through electrostatic interaction to form a complex. These results provide important insights into the combination of environmental pollutants with HA. [Display omitted] • HPPDi quenched the endogenous fluorescence of HA. • HA-HPPDi complex was formed through electrostatic interaction. • The binding capacity of mesotrione with HA was the strongest. • The main functional group of HA binding to HPPDi is C O. • pH 7 is prone to the formation of HA-HPPDi complex. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) have been demonstrated to play critical roles in the pathogenesis of human cancers and carcinogenesis of several environmental pollutants. Nevertheless, the function of circRNAs in cadmium carcinogenesis is unclear. circ-SHPRH is down-regulated in many cancers including non-small cell lung cancer. In our present study, during cadmium-induced transformation of human bronchial epithelial BEAS-2B cells, epithelial-mesenchymal transition (EMT) was induced. Meanwhile, at the middle and late stages of cell transformation, cadmium down-regulated the expression of circ-SHPRH, as well as QKI, a tumor suppressor protein known to prevent the proliferation and EMT during progression of human cancers, compared with passage-matched control BEAS-2B cells. Overexpression of circ-SHPRH in cadmium-transformed BEAS-2B cells promoted the expression of QKI and significantly inhibited proliferation, EMT, invasion, migration and anchorage-independent growth in soft agar of the cells. Mechanistic studies showed that circ-SHPRH functioned as a sponge of miR-224–5p to regulate QKI expression. Interestingly, QKI and circ-SHPRH could form a positive-feedback loop that perpetuated circ-SHPRH/miR-224–5p/QKI axis. Collectively, our results demonstrated that circ-SHPRH inhibited cadmium-induced transformation of BEAS-2B cells through sponging miR-224–5p to regulate QKI expression under cadmium treatment. Our study uncovered a novel molecular mechanism involved in circRNAs in the development of lung cancer due to cadmium exposure. [Display omitted] • Circ-SHPRH was decreased during cadmium-induced transformation of BEAS-2B cells. • Circ-SHPRH acted as an miR-224–5p sponge and downregulated miR-224–5p target QKI. • Downregulated QKI promoted cell transformation induced by cadmium. • Circ-SHPRH and QKI could provoke a positive-feedback loop in cadmium-treated cells. • Circ-SHPRH and QKI are promising targets to protect against cadmium-induced lung cancer. [ABSTRACT FROM AUTHOR]

The purpose of this study is to examine the association between hourly air pollution on hourly physical activity (PA) and sedentary behavior (SB) among college students in Beijing, China. The secondary aim was to examine such associations varied at specific time. A total of 340 participants were recruited from the Tsinghua University, in Beijing, China. Accelerometers provided PA measures, including moderate-to-vigorous physical activity (MVPA), walking steps, energy expenditure and sedentary time for 7 consecutive days. Corresponding air pollution data by the Beijing Municipal Ecological Environment Bureau in the closed site (Wan Liu site) in Tsinghua University were collected including average hourly air quality index (AQI) and PM 2.5 (μg/m³). Associations were estimated using linear individual fixed-effect regressions. We also conducted an air pollution risk perception survey among 2307 freshmen (76.6% males) who were enrolled in Tsinghua in 2016, and the survey was done in May 22–26, 2017. A one level increase in hourly air quality index (AQI) was associated with a reduction in 1-h PA by 0.083 (95% confidence interval [CI] = -0.137, −0.029) minutes of MVPA, 8.8 (95% CI = −15.0, −2.6) walking steps, 0.65 (95% CI = -1.03, −0.27) kcals of energy expenditure. A 10 μg/m³ increase in air pollution concentration in hourly PM 2.5 was associated with a reduction in 1-h PA by 0.021 (95% confidence interval [CI] = -0.033, −0.010) minutes of MVPA, 2.2 (95% CI = −3.5, −0.9) walking steps, 0.170 (95% CI = -0.250, −0.089) kcals of energy expenditure an increase in 1-h sedentary behavior 0.045 (0.005, 0.0845). At specific time, stronger negative associations of AQI and PM 2.5 air pollution with PA at 8 a.m., 4 p.m., 5 p.m. and 7 p.m. Similarly, stronger positive associations of 1 h AQI and PM 2.5 air pollution with SB at 8 a.m., 9 a.m., 11 a.m., and 7 p.m. A total of 94.9% participants (n = 2235) responded "yes" to air pollution change activities in the survey, which may partially explain PA change. Air pollution may discourage physical activity and increases sedentary behavior among freshman students living in Beijing, China. This is preliminary study. The impact of air pollution on physical activity and sedentary behavior at a specific time may be different. There are large variations in walking steps in specific time. Trend for walking steps in specific time in one day among the freshman. Image 1 • Air pollution may discourage physical activity behavior. • Air pollution may increase sedentary behavior. • The impact of air pollution on health behavior may be different at a specific time. [ABSTRACT FROM AUTHOR]