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النتائج 311 - 320 من 6,558
Maternal preconception phthalate metabolite concentrations in follicular fluid and neonatal birth weight conceived by women undergoing in vitro fertilization النص الكامل
2020
Wu, Lin-Jing | Teng, Xue-Mei | Yao, Yang-Cheng | Liu, Chong | Du, Yao-Yao | Deng, Tao-Ran | Yuan, Xiao-Qiong | Zeng, Qiang | Li, Yu-Feng | Guo, Na
Exposure to phthalates during gestation has been associated with decreased birth weight among offspring. However, the associations between preconception phthalate metabolites in follicular fluid (FF) and offspring birth weight among women undergoing in vitro fertilization (IVF) remain largely unknown. Here, we explored the associations between preconception phthalate metabolite concentrations in FF and the birth weights of singletons and twins among women undergoing IVF. We recruited 147 female participants who gave birth to 90 singletons and 57 twin infants at the Reproductive Medicine Center, Tongji Hospital, Wuhan, between November and December 2016. Each participant was asked to complete a questionnaire at the time of recruitment and provide a FF sample on the day of oocyte retrieval. The FF concentrations of eight phthalate metabolites were determined using high-performance liquid chromatography and tandem mass spectrometry. Birth outcomes were abstracted from medical records. The associations between phthalate metabolites in FF and birth weights of the singleton and twin groups were evaluated using generalized linear models (GLMs). We found that birth weight in the twin group had negative dose-response associations with maternal preconception monobenzyl phthalate (MBzP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) in FF (both P for trends < 0.05) and that birth weight in the singleton group had positive dose-response associations with monoethyl phthalate (MEP) and mono(2-ethyl-5 hydroxyhexyl) phthalate (MEHHP) in FF (both P for trends < 0.05). These associations persisted when we modeled as continuous variables. In addition, we observed male-specific association between decreased twin birth weight and MEOHP and MBzP and a female-specific associations between increased singleton birth weight and MEP, MEHHP and the sum of di(2-ethylhexyl) phthalate (∑DEHP) (all P for interactions < 0.05). Preconception phthalate metabolites in maternal FF may affect the birth weights of both singleton and twin newborns.
اظهر المزيد [+] اقل [-]Meteorological variations impeded the benefits of recent NOx mitigation in reducing atmospheric nitrate deposition in the Pearl River Delta region, Southeast China النص الكامل
2020
Zhong, Buqing | Wang, Xuemei | Ye, Lyumeng | Ma, Mingrui | Jia, Shiguo | Chen, Weihua | Yan, Fenghua | Wen, Zhang | Padmaja, Krishnan
The trends and variability of atmospheric nitrogen deposition in the Pearl River Delta (PRD) region for the period 2008–2017 were investigated by integrating ground- and satellite-based observations and a chemical transport model, in order to gauge the effects of emission reductions and meteorological variability. We show that dry deposition observation of oxidized nitrogen decreased at the rate of 2.4% yr⁻¹ for a moderate reduction in NOₓ emissions by 27% in the past decade, while reduced nitrogen presented an increase at the rate of 2.3% yr⁻¹ despite no regulated interventions for NH₃ emissions, which is likely related to changes in atmospheric gas-particle partitioning of NH₃ as reductions in SO₂ and NOₓ emissions. These results coincide with the trends in ground-level concentrations of oxidized and reduced nitrogen compounds in the atmosphere during 2008–2017. The changes in annual deposition fluxes of total oxidized and reduced nitrogen are not statistically significant trends and largely related with the inter-annual variability in their corresponding wet depositions, which reflects combined effects of variability in precipitation amount, and changes in atmospheric nitrogen compounds which dominates wet deposition of the oxidized and reduced forms. The meteorological conditions can mask 34% and 25% decrease in total oxidized and reduced nitrogen deposition on the decadal timescale, respectively. We conclude that meteorology-driven variability probably have masked the full response of oxidized nitrogen deposition to NOₓ emissions reduction. Our results also imply that persistent and integrated emission control strategies on NOₓ and NH₃ are needed to effectively reduce total nitrogen deposition fluxes towards the critical limit in the PRD region.
اظهر المزيد [+] اقل [-]Urban particulate matter disturbs the equilibrium of mitochondrial dynamics and biogenesis in human vascular endothelial cells النص الكامل
2020
Wang, Yan | Kong, Lu | Wu, Tianshu | Tang, Meng
Since ambient particulate matter (APM) is closely related to cardiovascular damage with mitochondria being its potential targets, this study was designed to explore the impact of APM on mitochondrial homeostasis, especially on mitochondrial dynamics and biogenesis in human vascular endothelial cells, using a kind of standard material, PM SRM1648a. As a result, internalized particles lead to mitochondrial dysfunction in EA.hy926 human endothelial cells, including mitochondrial reactive oxygen species (mtROS) overproduction, mitochondrial membrane potential (MMP) reduction and adenosine triphosphate (ATP) inhibition, coupled with additional release of mitochondrial DNA (mtDNA) into the cytosol. Moreover, morphological and structural changes in mitochondria are observed in response to PM SRM1648a. In that aspect, according to the evidence of shorter fragmented mitochondria dispersed throughout the cytoplasm, along with aberrant upregulation of fission-related mRNAs/proteins, the mitochondria exhibit a fission phenotype shifting from intact reticular network to fragmentized punctate shapes. Mechanistically, PM SRM1648a facilitates phosphorylation of DRP1 at Ser616 in HUVECs, and triggers its dephosphorylation at Ser637 residue in both EA.hy926 and HUVECs, which are supportive events for mitochondrial fission during particle exposure. Additionally, suppression of a master energy modulator, PGC-1α, reveals that PM SRM1648a has the ability to impair mitochondrial biogenesis. Collectively, it could be well concluded that PM SRM1648a interferes with the equilibrium of mitochondrial dynamics and biogenesis, which is likely to play a pivotal role in mitochondrial dysfunction driven by particles, eventually contributing to endothelial cell damage. Of note, it is more reasonable to conduct risk assessment from both cellular level and subcellular structures, among which mitochondria-targeted toxicity supplements more comprehensive understanding of APM inducible vascular toxicity.
اظهر المزيد [+] اقل [-]Diurnal and temporal changes in air pollution during COVID-19 strict lockdown over different regions of India النص الكامل
2020
Singh, Vikas | Singh, Shweta | Biswal, Akash | Kesarkar, Amit P. | Mor, Suman | Ravindra, Khaiwal
Lockdown measures to contain COVID-19 pandemic has resulted in a considerable change in air pollution worldwide. We estimate the temporal and diurnal changes of the six criteria air pollutants, including particulate matter (PM₂.₅ and PM₁₀) and gaseous pollutants (NO₂, O₃, CO, and SO₂) during lockdown (25ᵗʰ March – 3ʳᵈ May 2020) across regions of India using the observations from 134 real-time monitoring sites of Central Pollution Control Board (CPCB). Significant reduction in PM₂.₅, PM₁₀, NO₂, and CO has been found in all the regions during the lockdown. SO₂ showed mixed behavior, with a slight increase at some sites but a comparatively significant decrease at other locations. O₃ also showed a mixed variation with a mild increase in IGP and a decrease in the South. The absolute decrease in PM₂.₅, PM₁₀, and NO₂ was observed during peak morning traffic hours (08–10 Hrs) and late evening (20–24 Hrs), but the percentage reduction is almost constant throughout the day. A significant decrease in day-time O₃ has been found over Indo Gangetic plain (IGP) and central India, whereas night-time O₃ has increased over IGP due to less O₃ loss. The most significant reduction (∼40–60%) was found in PM₂.₅ and PM₁₀. The highest decrease in PM was found for the north-west and IGP followed by South and central regions. A considerable reduction (∼30–70%) in NO₂ was found except for a few sites in the central region. A similar pattern was observed for CO having a ∼20–40% reduction. The reduction observed for PM₂.₅, PM₁₀, NO₂, and enhancement in O₃ was proportional to the population density. Delhi’s air quality has improved with a significant reduction in primary pollutants, however, an increase in O₃ was observed. The changes reported during the lockdown are combined effect of changes in the emissions, meteorology, and atmospheric chemistry that requires detailed investigations.
اظهر المزيد [+] اقل [-]Insights into acetate-mediated copper homeostasis and antioxidant defense in lentil under excessive copper stress النص الكامل
2020
Shahadat Hossain, Md. | Abdelrahman, Mostafa | Tran, Cuong Duy | Nguyen, Kien Huu | Chu, Ha Duc | Watanabe, Yasuko | Hasanuzzaman, Mirza | Mohsin, Sayed Mohammad | Fujita, Masayuki | Tran, Lam-son Phan
Gradual contamination of agricultural land with copper (Cu), due to the indiscriminate uses of fungicides and pesticides, and the discharge of industrial waste to the environment, poses a high threat for soil degradation and consequently food crop production. In this study, we combined morphological, physiological and biochemical assays to investigate the mechanisms underlying acetate-mediated Cu toxicity tolerance in lentil. Results demonstrated that high dose of Cu (3.0 mM CuSO₄. 5H₂O) reduced seedling growth and chlorophyll content, while augmenting Cu contents in both roots and shoots, and increasing oxidative damage in lentil plants through disruption of the antioxidant defense. Principle component analysis clearly indicated that Cu accumulation and increased oxidative damage were the key factors for Cu toxicity in lentil seedlings. However, acetate pretreatment reduced Cu accumulation in roots and shoots, increased proline content and improved the responses of antioxidant defense (e.g. increased catalase and glutathione-S-transferase activities, and improved action of glutathione-ascorbate metabolic pathway). As a result, excess Cu-induced oxidative damage was reduced, and seedling growth was improved under Cu stress conditions, indicating the role of acetate in alleviating Cu toxicity in lentil seedlings. Taken together, exogenous acetate application reduced Cu accumulation in lentil roots and shoots and mitigated oxidative damage by activating the antioxidant defense, which were the major determinants for alleviating Cu toxicity in lentil seedlings. Our findings provide mechanistic insights into the protective roles of acetate in mitigating Cu toxicity in lentil, and suggest that application of acetate could be a novel and economical strategy for the management of heavy metal toxicity and accumulation in crops.
اظهر المزيد [+] اقل [-]The effect of residual hydrocarbons in soil following oil spillages on the growth of Zea mays plants النص الكامل
2020
Grifoni, M. | Rosellini, I. | Angelini, P. | Petruzzelli, G. | Pezzarossa, B.
Liquid hydrocarbon pipeline accidents, including leaks due to the illegal or unauthorized collection of petroleum from oil pipelines, are a widespread phenomenon that can lead to pollution that may negatively affect soil quality and plant growth. The aim of this study is to evaluate hydrocarbon uptake and accumulation in Zea mays plants grown on soil affected by spills of fossil fuels. The experiments were conducted in microcosm, mesocosm and field tests. The potential transfer of contaminants from soil to plant and their effects on plant growth were investigated. The results from both the laboratory and field experiments showed that the plants grew better in the uncontaminated soil than in the soil polluted by hydrocarbons. Despite their significantly lower aerial biomass, plants grown in contaminated soil did not show any significant differences in C > 12 concentration, either in shoots or roots, compared to the control plants. Thus, the decrease in plant yield might not be attributed to hydrocarbons accumulation in the plant tissues and may rather be due to a reduced soil fertility, which negatively affected plant growth.Under our experimental conditions, the hydrocarbons present in the contaminated soil were not absorbed by the plants and did not accumulate in plant tissue or in grains, thus avoiding the risk of them entering the food chain.
اظهر المزيد [+] اقل [-]Occurrence of pharmaceuticals in the Danube and drinking water wells: Efficiency of riverbank filtration النص الكامل
2020
Kondor, Attila Csaba | Jakab, Gergely | Vancsik, Anna | Filep, Tibor | Szeberényi, József | Szabó, Lili | Maász, Gábor | Ferincz, Árpád | Dobosy, Péter | Szalai, Zoltán
Surface waters are becoming increasingly contaminated by pharmaceutically active compounds (PhACs), which is a potential risk factor for drinking water quality owing to incomplete riverbank filtration. This study examined the efficiency of riverbank filtration with regard to 111 PhACs in a highly urbanized section of the river Danube. One hundred seven samples from the Danube were compared to 90 water samples from relevant drinking water abstraction wells (DWAW) during five sampling periods. The presence of 52 PhACs was detected in the Danube, the quantification of 19 agents in this section of the river was without any precedent, and 10 PhACs were present in >80% of the samples. The most frequent PhACs showed higher concentrations in winter than in summer. In the DWAWs, 32 PhACs were quantified. For the majority of PhACs, the bank filtration efficiency was >95%, and not influenced by concentrations measured in the river. For carbamazepine lidocaine, tramadol, and lamotrigine, low (<50%) filtration efficiency was observed; however, no correlations were observed between the concentrations detected in the Danube and in the wells. These frequently occurring PhACs in surface waters have a relatively even distribution, and their sporadic appearance in wells is a function of both space and time, which may be caused by the constantly changing environment and micro-biological parameters, the dynamic operating schedule of abstraction wells, and the resulting sudden changes in flow rates. Due to the changes in the efficiency of riverbank filtration in space and time, predicting the occurrence and concentrations of these four PhACs poses a further challenge to ensuring a safe drinking water supply.
اظهر المزيد [+] اقل [-]The influence of nanoplastics on the toxic effects, bioaccumulation, biodegradation and enantioselectivity of ibuprofen in freshwater algae Chlorella pyrenoidosa النص الكامل
2020
Wang, Fang | Wang, Bin | Qu, Han | Zhao, Wenxing | Duan, Lei | Zhang, Yizhe | Zhou, Yitong | Yu, Gang
Plastic pollution has become a pressing issue due to its persistence in the environment. Smaller plastics are more easily ingested, potentially exerting greater influences on organisms. In this study, the effects of polystyrene nanoplastics (NP) on the toxic effects, bioaccumulation, biodegradation and enantioselectivity of ibuprofen (IBU) in algae Chlorella pyrenoidosa were explored. The influences on the growth rate, chlorophyll a, total antioxidant capacity (T-AOC), reactive oxygen species (ROS) and lipid peroxidation (MDA) were evaluated after 96 h of exposure to a combination of polystryene NP (1 mg L⁻¹) and IBU (5–100 mg L⁻¹). The results indicated that the inhibitory effect of IBU on C. pyrenoidosa growth was alleviated in the presence of NP. For instance, the 96 h-IC₅₀ value for rac-IBU in the treatment lacking NP was 45.7 mg L⁻¹, and the corresponding value in the treatment containing NP was 63.9 mg L⁻¹. The co-exposure of NP led to a significant enhancement of T-AOC and slight reduction of ROS and MDA compared with the individual exposure (IBU) group, suggesting a decreased oxidative stress. In addition, treatment with NP led to a decreased bioaccumulation and accelerated biodegradation of IBU in C. pyrenoidosa and enhanced removal in the medium. The enantioselective toxicity, bioaccumulation and biodegradation of IBU were observed both in the absence and presence of NP. S-IBU exhibited a greater toxicity, and R-IBU was preferentially accumulated and degraded in C. pyrenoidosa. No interconversion of the two enantiomers occurred regardless of the presence of NP. This consequence implied that the influence of coexistent NP should be considered in the environmental risk assessment of pharmaceuticals and personal care products in aquatic environments.
اظهر المزيد [+] اقل [-]Prediction of plant species occurrence as affected by nitrogen deposition and climate change on a European scale النص الكامل
2020
Wamelink, G.W.W. | Mol-Dijkstra, J.P. | Reinds, G.J. | Voogd, J.C. | Bonten, L.T.C. | Posch, M. | Hennekens, S.M. | de Vries, W.
Plant species occurrence in Europe is affected by changes in nitrogen deposition and climate. Insight into potential future effects of those changes can be derived by a model approach based on field-based empirical evidence on a continental scale. In this paper, we present a newly developed empirical model PROPS, predicting the occurrence probabilities of plant species in response to a combination of climatic factors, nitrogen deposition and soil properties. Parameters included were temperature, precipitation, nitrogen deposition, soil pH and soil C/N ratio. The PROPS model was fitted to plant species occurrence data of about 800,000 European relevés with estimated values for pH and soil C/N ratio and interpolated climate and modelled N deposition data obtained from the Ensemble meteo data set and EMEP model results, respectively. The model was validated on an independent data set. The test of ten species against field data gave an average Pearson’s r-value of 0.79.PROPS was applied to a grassland and a heathland site to evaluate the effect of scenarios for nitrogen deposition and climate change on the Habitat Suitability Index (HSI), being the average of the relative probabilities, compared to the maximum probability, of all target species in a habitat. Results for the period 1930–2050 showed that an initial increase and later decrease in nitrogen deposition led to a pronounced decrease in HSI, and with dropping nitrogen deposition to an increase of the HSI. The effect of climate change appeared to be limited, resulting in a slight increase in HSI.
اظهر المزيد [+] اقل [-]Physiological, ultrastructural, biochemical, and molecular responses of glandless cotton to hexavalent chromium (Cr6+) exposure النص الكامل
2020
Samrana, Samrana | ʻAlī, ʻĀbid | Muhammad, Uzair | Azizullah, Azizullah | Ali, Hamid | Khan, Mumtaz | Naz, Shama | Khan, Muhammad Daud | Zhu, Shuijin | Chen, Jinhong
Glandless cotton can be grown to obtain cotton seeds free of toxic gossypol for use as both food and feed. However, they are not grown normally due to their lesser productivity and higher susceptibility to biotic stress. Great attention has been paid to biotic stresses rather than abiotic stresses on glandless cotton. Chromium (Cr) is a common pollutant of soil and considered a serious threat to plants due to its adverse effects on different functions. Although numerous studies are available on the toxicity of Cr⁶⁺ in various plants. However, its adverse effects and mechanism of toxicity in glandless cotton can seldom be found in the literature. This study examined the Cr⁶⁺ effect on glandless cotton in comparison to glanded cotton. Four pairs of glanded and glandless cotton near-isogenic lines (NILs) were exposed to different doses (0, 10, 50, and 100 μM/L) of Cr⁶⁺ for seven days, and biochemical, physiological, molecular, and ultrastructure changes were observed, which were significantly affected by Cr⁶⁺ at high concentrations in all NILs. The effect of Cr⁶⁺ on ionic contents shows the same trend in glanded and glandless NILs except for manganese (Mn²⁺) that show inhibition in glandless (ZMS-12w and Coker-312w) and enhance in the glanded NIL (ZMS-17). The gene expression of superoxide dismutase (SOD) and peroxidase (POD) revealed similar trends as enzyme activities in glandless NILs. The principal component analysis (PCA) and Agglomerative hierarchical clustering (AHC) results of all NILs from morpho-physiological traits, cluster ZMS-16, and ZMS-17 into Cr⁶⁺ sensitive group. While the glandless NILs have the potential to cope with the Cr toxicity by increasing the antioxidant enzyme activity and their gene expression. This study also revealed that Cr⁶⁺ tolerance in cotton is genotypic and has an independent mechanism in the root that not related to low gossypol.
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