细化搜索
结果 331-340 的 4,309
Short-term association between personal exposure to noise and heart rate variability: The RECORD MultiSensor Study 全文
2017
El Aarbaoui, Tarik | Méline, Julie | Brondeel, Ruben | Chaix, Basile
Studies revealed long-term associations between noise exposure and cardiovascular health, but the underlying short-term mechanisms remain uncertain.To explore the concomitant and lagged short-term associations between personal exposure to noise and heart rate variability (HRV) in a real life setting in the Île-de-France region.The RECORD MultiSensor Study collected between July 2014 and June 2015 noise and heart rate data for 75 participants, aged 34–74 years, in their living environments for 7 days using a personal dosimeter and electrocardiography (ECG) sensor on the chest. HRV parameters and noise levels were calculated for 5-min windows. Short-term relationships between noise level and log-transformed HRV parameters were assessed using mixed effects models with a random intercept for participants and a temporal autocorrelation structure, adjusted for heart rate, physical activity (accelerometry), and short-term trends.An increase by one dB(A) of A-weighted equivalent sound pressure level (Leq) was associated with a 0.97% concomitant increase of the Standard deviation of normal to normal intervals (SDNN) (95% CI: 0.92, 1.02), of 2.08% of the Low frequency band power (LF) (95% CI: 1.97, 2.18), of 1.30% of the High frequency band power (HF) (95% CI: 1.17, 1.43), and of 1.16% of the LF/HF ratio (95% CI: 1.10, 1.23). The analysis of lagged exposures to noise adjusted for the concomitant exposure illustrates the dynamic of recovery of the autonomic nervous system. Non-linear associations were documented with all HRV parameters with the exception of HF. Piecewise regression revealed that the association was almost 6 times stronger below than above 65 Leq dB(A) for the SDNN and LF/HF ratio.Personal noise exposure was found to be related to a concomitant increase of the overall HRV, with evidence of imbalance of the autonomic nervous system towards sympathetic activity, a pathway to increased cardiovascular morbidity and mortality.
显示更多 [+] 显示较少 [-]The first exposure assessment of legacy and unrestricted brominated flame retardants in predatory birds of Pakistan 全文
2017
Abbasi, Naeem Akhtar | Eulaers, Igor | Jaspers, Veerle Leontina Bernard | Chaudhry, Muhammad Jamshed Iqbal | Frantz, Adrien | Ambus, Per Lennart | Covaci, Adrian | Malik, Riffat Naseem
The first exposure assessment of legacy and unrestricted brominated flame retardants in predatory birds of Pakistan 全文
2017
Abbasi, Naeem Akhtar | Eulaers, Igor | Jaspers, Veerle Leontina Bernard | Chaudhry, Muhammad Jamshed Iqbal | Frantz, Adrien | Ambus, Per Lennart | Covaci, Adrian | Malik, Riffat Naseem
The exposure to legacy polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs) and unrestricted 1,2-bis (2,4,6-tribromophenoxy) ethane (BTBPE), bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5-tetrabromo-benzoate (EH-TBB) was examined in tail feathers of 76 birds belonging to ten predatory species inhabiting Pakistan. In addition, different feather types of six individuals of Black kite (Milvus migrans) were compared for their brominated flame retardant (BFR) levels. Black kite was found to be the most contaminated species with a median (minimum-maximum) tail feather concentration of 2.4 (0.70–7.5) ng g−1 dw for ∑PBDEs, 1.5 (0.5–8.1) ng g−1 dw for ∑HBCDDs and 0.10 (<LOQ-0.1) ng g−1 dw for BTBPE. Among unrestricted BFRs, BTBPE was detected only in Black kite and Little owl (Athene noctua), whereas BEH-TEBP and EH-TBB were not detected in any species. BDE-47 was found to be the most prevalent BFR compound in aquatic species, while BDE-99 and -153 were more abundant in terrestrial species. For HBCDDs, α-isomer was generally recorded as the most prevalent BFR in both terrestrial and aquatic species. The concentrations of BFRs differed significantly (all P < 0.01) among species, trophic guilds and between habitats, the latter for PBDEs only (P < 0.04), whereas differences among taxonomic affiliations and groups with different feeding regimes were not significant (P > 0.05 for both). Similarly, no significant concentration differences were observed among different feather types (all P > 0.05) suggesting their similar exposure. While variables such as species, trophic guild and δ15N values were evaluated as major predictors for BFR accumulation in the studied species, we predict that combined effects of just mentioned factors may govern the intra- and interspecific differences in BFR contamination profiles. We urge for further investigation of BFR exposure and potential toxicological effects in predatory birds from Asia with a more extensive sample size per species and location.
显示更多 [+] 显示较少 [-]The first exposure assessment of legacy and unrestricted brominated flame retardants in predatory birds of Pakistan 全文
2017
Abbasi, Naeem Akhtar | Eulaers, Igor | Jaspers, Veerle Leontina Bernard | Chaudhry, Muhammad Jamshed Iqbal | Frantz, Adrien | Ambus, Per Lennart | Covaci, Adrian | Malik, Riffat Naseem | Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences ; Quaid-i-Azam University (QAU) | Department of Bioscience ; Aarhus University [Aarhus] | Environmental Toxicology, Department of Biology ; Norwegian University of Life Sciences (NMBU) | WWF Pakistan | Institut d'écologie et des sciences de l'environnement de Paris (iEES) ; Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS) | Center for Permafrost (CENPERM) ; Department of Geosciences and Natural Resource Management [Copenhagen] (IGN) ; Faculty of Science [Copenhagen] ; University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen] ; University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH) | Toxicological Centre ; University of Antwerp (UA) | Higher Education Commission (HEC), Quaid-i-Azam University, Pakistan; NRC Project New Raptor [230465/F20]; Norwegian University of Science and Technology, Norway
The exposure to legacy polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs) and unrestricted 1,2-bis (2,4,6-tribromophenoxy) ethane (BTBPE), bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5-tetrabromo-benzoate (EH-TBB) was examined in tail feathers of 76 birds belonging to ten predatory species inhabiting Pakistan. In addition, different feather types of six individuals of Black kite (Milvus migrans) were compared for their brominated flame retardant (BFR) levels. Black kite was found to be the most contaminated species with a median (minimum-maximum) tail feather concentration of 2.4 (0.70-7.5) ng g(-1) dw for Sigma PBDEs, 1.5 (0.5-8.1) ng g(-1) dw for Sigma HBCDDs and 0.10 (<LOQ-0.1) ng g(-1) dw for BTBPE. Among unrestricted BFRs, BTBPE was detected only in Black kite and Little owl (Athene noctua), whereas BEH-TEBP and EH-TBB were not detected in any species. BDE-47 was found to be the most prevalent BFR compound in aquatic species, while BDE-99 and -153 were more abundant in terrestrial species. For HBCDDs, alpha-isomer was generally recorded as the most prevalent BFR in both terrestrial and aquatic species. The concentrations of BFRs differed significantly (all P < 0.01) among species, trophic guilds and between habitats, the latter for PBDEs only (P < 0.04), whereas differences among taxonomic affiliations and groups with different feeding regimes were not significant (P > 0.05 for both). Similarly, no significant concentration differences were observed among different feather types (all P > 0.05) suggesting their similar exposure. While variables such as species, trophic guild and delta N-15 values were evaluated as major predictors for BFR accumulation in the studied species, we predict that combined effects of just mentioned factors may govern the intra- and interspecific differences in BFR contamination profiles. We urge for further investigation of BFR exposure and potential toxicological effects in predatory birds from Asia with a more extensive sample size per species and location.
显示更多 [+] 显示较少 [-]ATM signals to AMPK to promote autophagy and positively regulate DNA damage in response to cadmium-induced ROS in mouse spermatocytes 全文
2017
Li, Renyan | Luo, Xue | Zhu, Yijian | Zhao, Letian | Li, Lianbing | Peng, Qiang | Ma, Mingfu | Gao, Yanfei
Cadmium (Cd) is a toxic heavy metal and harmful to human health due to its ability to accumulate in organs. Previous studies have shown that Cd can induce DNA damage and autophagy. Autophagy can stabilize genetic material and DNA integrity. The aim of the present study was to determine the exact mechanism and role of autophagy induced by Cd in spermatozoa cells. Mouse spermatocyte-derived cells (GC-2) were treated with 20 μM Cd chloride for 24 h. The level of reactive oxygen species (ROS), DNA damage, autophagy and the expression of the molecular signaling pathway ATM/AMP-activated protein kinase (AMPK)/mTOR were determined. The results showed that Cd induced autophagy and DNA damage in GC-2 cells via ROS generation, and the autophagy signal pathway AMPK/mTOR was activated by ATM which is a DNA damage sensor. Melatonin, a well-known antioxidant, ameliorated DNA damage, and inhibited autophagy via the AMPK/mTOR signal pathway. Furthermore, after inhibition of autophagy by knockdown of AMPKα, increased DNA damage by Cd treatment was observed in GC-2 cells. These findings demonstrated the protective role of autophagy in DNA damage and suggested that the mechanism of autophagy induced by Cd was through the ATM/AMPK/mTOR signal pathway in spermatozoa cells.
显示更多 [+] 显示较少 [-]Molecular investigation on the binding of Cd(II) by the binary mixtures of montmorillonite with two bacterial species 全文
2017
Du, Huihui | Qu, ChenChen | Liu, Jing | Chen, Wenli | Cai, Peng | Shi, Zhihua | Yu, Xiao-Ying | Huang, Qiaoyun
Bacteria–phyllosilicate complexes are commonly found in natural environments and are capable of immobilizing trace metals. However, the molecular binding mechanisms of heavy metals to these complex aggregates still remain poorly understood. This study investigated Cd adsorption on Gram-positive Bacillus subtilis, Gram-negative Pseudomonas putida and their binary mixtures with montmorillonite using surface complexation model, Cd K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy and isothermal titration calorimetry (ITC). We have shown that larger amounts of Cd are adsorbed by B. subtilis than by P. putida at pH<∼6, and Cd sorption that binding to phosphate groups plays a more important role in P. putida than in B. subtilis. This remind us that we should consider the microbe species when predict the biochemical behavior of trace metals in microbe-bearing environments. The observed Cd adsorption on the binary bacteria–clay composites was more than that predicted based on the component additivity approach. When taking bacteria–clay (1:1 mass ratio) as a representative example, an approximately 68%:32% metal distribution between the bacterial and mineral fraction was found. Both the EXAFS and ITC fits showed that the binding stoichiometry for Cd-carboxyl/phosphate was smaller in the binary mixtures than that in pure bacteria. We proposed that the significant deviations were possibly due to the physical-chemical interaction between the composite fractions that might reduce the agglomeration of the clay grains, increase the negative surface charges, and provide additional bridging of metals ions between bacterial cells and clays.
显示更多 [+] 显示较少 [-]PAHs accelerate the propagation of antibiotic resistance genes in coastal water microbial community 全文
2017
Wang, Jing | Wang, Jing | Zhao, Zelong | Chen, Jingwen | Lu, Hong | Liu, Guangfei | Zhou, Jiti | Guan, Xiaoyan
Antibiotic resistance genes (ARGs) have been regarded as emerging contaminants and have attracted growing attention owing to their widespread presence in the environment. In addition to the well-documented selective pressure of antibiotics, ARGs have also become prevalent because of anthropogenic impacts. Coastal habitats are located between terrestrial and marine ecosystems, which are a hotspot for anthropogenic impacts. Excessive accumulation of polycyclic aromatic hydrocarbons (PAHs) has posed a serious threat to coastal habitats, but no information is available on the effect of PAHs on antibiotic resistance in the microbial community of coastal environments. In this study, the effect of two typical PAHs, naphthalene and phenanthrene, on antibiotic resistance propagation was investigated in a coastal microbial community. The results indicated that the presence of 100 mg/L of naphthalene or 10 mg/L of phenanthrene significantly enhanced the abundance of class I integrase gene (intI1), sulfanilamide resistance gene (sulI), and aminoglycosides resistance gene (aadA2) in the microbial community. Horizontal gene transfer experiment demonstrated that increased abundance of ARGs was primarily a result of conjugative transfer mediated by class I integrons. These findings provided direct evidence that coastal microbial community exposed to PAHs might have resulted in the dissemination of ARGs and implied that a more comprehensive risk assessment of PAHs to natural ecosystems and public health is necessary.
显示更多 [+] 显示较少 [-]The use of buccal swabs as a minimal-invasive method for detecting effects of pesticide exposure on enzymatic activity in common wall lizards 全文
2017
Mingo, Valentin | Lötters, Stefan | Wagner, Norman
Habitat loss and environmental pollution are among the main causes responsible for worldwide biodiversity loss. The resulting species and population declines affect all vertebrates including reptiles. Especially in industrialized countries, pollution by agrochemicals is of remarkable importance. Here, habitat loss has historically been associated with expansion of agriculture. Species persisting in such environments do not only need to cope with habitat loss, but more recently, also with chemical intensification, namely pesticide exposure. In this study, we examined effects of different fungicide and herbicide applications on the common wall lizard (Podarcis muralis) in grape-growing areas. We used three enzymatic biomarkers (GST, GR, AChE) and for the first time saliva from buccal swabs as a minimal-invasive sampling method for detection. Our results demonstrate absorption of substances by lizards and effects of pesticide exposure on enzymatic activities. Our findings are in accordance with those of previous laboratory studies, although samples were retrieved from natural habitats. We conclude that buccal swabs could become a useful tool for the detection of pesticide exposure in reptiles and have the potential to replace more invasive methods, such as organ extraction or cardiac puncture. This is an important finding, as reptiles are non-target organisms of pesticide applications, and there is a strong need to integrate them into pesticide risk assessments.
显示更多 [+] 显示较少 [-]Laccase-mediated transformation of triclosan in aqueous solution with metal cations and humic acid 全文
2017
Sun, Kai | Kang, Fuxing | Waigi, Michael Gatheru | Gao, Yanzheng | Huang, Qingguo
Triclosan (TCS) is a broad-spectrum antimicrobial agent that is found extensively in natural aquatic environments. Enzyme-catalyzed oxidative coupling reactions (ECOCRs) can be used to remove TCS in aqueous solution, but there is limited information available to indicate how metal cations (MCs) and natural organic matter (NOM) influence the environmental fate of TCS during laccase-mediated ECOCRs. In this study, we demonstrated that the naturally occurring laccase from Pleurotus ostreatus was effective in removing TCS during ECOCRs, and the oligomerization of TCS was identified as the dominant reaction pathway by high-resolution mass spectrometry (HRMS). The growth inhibition studies of green algae (Chlamydomonas reinhardtii and Scenedesmus obliquus) proved that laccase-mediated ECOCRs could effectively reduce the toxicity of TCS. The presence of dissolved MCs (Mn²⁺, Al³⁺, Ca²⁺, Cu²⁺, and Fe²⁺ ions) influenced the removal and transformation of TCS via different mechanisms. Additionally, the transformation of TCS in systems with NOM derived from humic acid (HA) was hindered, and the apparent pseudo first-order kinetics rate constants (k) for TCS decreased as the HA concentration increased, which likely corresponded to the combined effect of both noncovalent (sorption) and covalent binding between TCS and humic molecules. Our results provide a novel insight into the fate and transformation of TCS by laccase-mediated ECOCRs in natural aquatic environments in the presence of MCs and NOM.
显示更多 [+] 显示较少 [-]Contaminants of emerging concern in the open sea waters of the Western Mediterranean 全文
2017
Brumovský, Miroslav | Bečanová, Jitka | Kohoutek, Jiří | Borghini, Mireno | Nizzetto, Luca
Pollution by chemical substances is of concern for the maintenance of healthy and sustainable aquatic environments. While the occurrence and fate of numerous emerging contaminants, especially pharmaceuticals, is well documented in freshwater, their occurrence and behavior in coastal and marine waters is much less studied and understood. This study investigates the occurrence of 58 chemicals in the open surface water of the Western Mediterranean Sea for the first time. 70 samples in total were collected in 10 different sampling areas. 3 pesticides, 11 pharmaceuticals and personal care products and 2 artificial sweeteners were detected at sub-ng to ng/L levels. Among them, the herbicide terbuthylazine, the pharmaceuticals caffeine, carbamazepine, naproxen and paracetamol, the antibiotic sulfamethoxazole, the antibacterial triclocarban and the two artificial sweeteners acesulfame and saccharin were detected in all samples. The compound detected at the highest concentration was saccharin (up to 5.23 ng/L). Generally small spatial differences among individual sampling areas point to a diffuse character of sources which are likely dominated by WWTP effluents and runoffs from agricultural areas or even, at least for pharmaceuticals and artificial food additives, from offshore sources such as ferries and cruising ships. The implications of the ubiquitous presence in the open sea of chemicals that are bio-active or toxic at low doses on photosynthetic organisms and/or bacteria (i.e., terbuthylazine, sulfamethoxazole or triclocarban) deserve scientific attention, especially concerning possible subtle impacts from chronic exposure of pelagic microorganisms.
显示更多 [+] 显示较少 [-]Polycyclic aromatic hydrocarbons (PAHs) enrich their degrading genera and genes in human-impacted aquatic environments 全文
2017
Yuan, Ke | Chen, Baowei | Qing, Qing | Zou, Shichun | Wang, Xiaowei | Luan, Tiangang
Bacterial degradation is an important clearance pathway for organic contaminants from highly human-impacted environments. However, it is not fully understood how organic contaminants are selected for degradation by bacteria and genes in aquatic environments. In this study, PAH degrading bacterial genera and PAH-degradation-related genes (PAHDGs) in sediments collected from the Pearl River (PR), the Pearl River Estuary (PRE) and the South China Sea (SCS), among which there were distinct differences in anthropogenic impact, were analyzed using metagenomic approaches. The diversity and abundance of PAH degrading genera and PAHDGs in the PR were substantially higher than those in the PRE and the SCS and were significantly correlated with the total PAH concentration. PAHDGs involved with the three key processes of PAH degradation (ring cleavage, side chain and central aromatic processes) were significantly correlated with each other in the sediments. In particular, plasmid-related PAHDGs were abundant in the PR sediments, indicating plasmid-mediated horizontal transfer of these genes between bacteria or the overgrowth of the bacteria containing these plasmids under the stresses of PAHs. Our results suggest that PAH degrading bacteria and genes were rich in PAH-polluted aquatic environments, which could facilitate the removal of PAHs by bacteria.
显示更多 [+] 显示较少 [-]Transport, retention, and long-term release behavior of polymer-coated silver nanoparticles in saturated quartz sand: The impact of natural organic matters and electrolyte 全文
2017
Hou, Jun | Zhang, Mingzhi | Wang, Peifang | Wang, Chao | Miao, Lingzhan | Xu, Yi | You, Guoxiang | Lv, Bowen | Yang, Yangyang | Liu, Zhilin
This study investigated the transport and long-term release of stabilized silver nanoparticles (AgNPs), including polyvinylpyrrolidone-coated AgNPs (PVP–AgNPs) and bare AgNPs (Bare–AgNPs), in the presence of natural organic matters (NOMs; both humic acids (HA) and alginate (Alg)) and an electrolyte (Ca2+) in a sand-packed column. Very low breakthrough rate (C/C0) of AgNPs (below 0.04) occurred in the absence of NOM and the electrolyte. Increasing the concentration of NOM and decreasing the influent NOM solution's ionic strength (IS) reduced the retention of AgNPs. The reduced NP retention at high NOM and low IS was mainly attributed to the increased energy barrier between the AgNPs and the sand grain surface. Notably, the retention of PVP–AgNPs was enhanced at high Alg concentration and low IS, which mainly resulted from the improved hydrophobicity that could increase the interaction between the PVP-AgNPs and the collector. The total release amount of PVP–AgNPs (10.03%, 9.50%, 28.42%, 6.37%) and Bare–AgNPs (3.28%, 2.58%, 10.36%, 1.54%) were gained when exposed to four kinds of NOM solutions, including deionized water, an electrolyte solution (1 mM Ca2+), HA with an electrolyte (1 mM Ca2+), and a Alg (40 mg/L) solution with an electrolyte (1 mM Ca2+). The long-term release of retained silver nanoparticles in the quartz sand was mostly through the form of released Ag NPs. The factors that increased the mobility of AgNPs in quartz sand could improve the release of the AgNPs. The release of AgNPs had no significant change in the presence Ca2+ but were increased in the presence of HA. The Alg slightly decreased the release of AgNPs by increasing the hydrophobicity of AgNPs. The results of the study indicated that all the tested NOM and Ca2+ have prominent influence on the transport and long-term release behavior of silver nanoparticles in saturated quartz sand.
显示更多 [+] 显示较少 [-]