Knowledge of the hazards and associated risks from chemicals discharged to the environment has grown considerably over the past 40 years. This improving awareness stems from advances in our ability ...to measure chemicals at low environmental concentrations, recognition of a range of effects on organisms, and a worldwide growth in expertise. Environmental scientists and companies have learned from the experiences of the past; in theory, the next generation of chemicals will cause less acute toxicity and be less environmentally persistent and bioaccumulative. However, researchers still struggle to establish whether the nonlethal effects associated with some modern chemicals and substances will have serious consequences for wildlife. Obtaining the resources to address issues associated with chemicals in the environment remains a challenge.
•A multiple-level system was proposed for risk rank of PPCPs in waters.•12 PPCPs showed environmental risks in Chinese surface waters.•Detected frequency, exposure and effect distribution were ...important to risk ranking.
Interest in the risks posed by trace concentrations of pharmaceuticals and personal care products (PPCPs) in surface waters is increasing, particularly with regard to potential effects of long-term, low-dose exposures of aquatic organisms. In most cases, the actual studies on PPCPs were risk assessments at screening-level, and accurate estimates were scarce. In this study, exposure and ecotoxicity data of 50 PPCPs were collected based on our previous studies, and a multiple-level environmental risk assessment was performed. The 50 selected PPCPs are likely to be frequently detected in surface waters of China, with concentrations ranging from the ng L−1 to the low-g L−1, and the risk quotients based on median concentrations ranged from 2046 for nonylphenol to 0 for phantolide. A semi-probabilistic approach screened 33 PPCPs that posed potential risks to aquatic organisms, among which 15 chemicals (nonylphenol, sulfamethoxazole, di (2-ethylhexyl) phthalate, 17β-ethynyl estradiol, caffeine, tetracycline, 17β-estradiol, estrone, dibutyl phthalate, ibuprofen, carbamazepine, tonalide, galaxolide, triclosan, and bisphenol A) were categorized as priority compounds according to an optimized risk assessment, and then the refined probabilistic risk assessment indicated 12 of them posed low to high risk to aquatic ecosystem, with the maximum risk products ranged from 1.54% to 17.38%. Based on these results, we propose that the optimized risk assessment was appropriate for screening priority contaminants at national scale, and when a more accurate estimation is required, the refined probability risk assessment is useful. The methodology and process might provide reference for other research of chemical evaluation and management for rivers, lakes, and sea waters.
The current highway waveform guardrail recognition technology has encountered problems with low segmentation accuracy and strong noise interference. Therefore, an improved U-net semantic segmentation ...model is proposed to improve the efficiency of road maintenance detection. The model training is guided by mixed expansion convolution and mixed loss function, while the presence of guardrail shedding is investigated by using partial mean values of gray values in ROI region based on segmentation results, while the first-order detail coefficients of wavelet transform are applied to detect guardrail defects and deformation. It has been determined that the Miou and Dice of the improved model are improved by 8.63% and 17.67%, respectively, over the traditional model, and that the method of detecting defects in the data is more accurate than 85%. As a result of efficient detection of highway waveform guardrail, the detection process is shortened and the effectiveness of the detection is improved later on during road maintenance.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Generally, sunflower seeds are classified by machine vision-based methods in production, which include using photoelectric sensors to identify light-sensitive signals through traditional algorithms ...for which the equipment cost is relatively high and using neural network image recognition methods to identify images through cameras for which the computational cost is high. To address these problems, a multi-objective sunflower seed classification method based on sparse convolutional neural networks is proposed. Sunflower seeds were obtained from the video recorded using the YOLOv5 Object detection algorithm, and a ResNet-based classification model was used to classify the seeds according to differences in appearance. The ResNet has the disadvantages of having numerous parameters and high storage requirements; therefore, this study referred to the Lottery Ticket Hypothesis and used the Iterative Magnitude Pruning algorithm to compress the sunflower seed classification model, aiming to ascertain the optimal sparse sub-network from the classification model. Experiments were conducted to compare the effects on model performance before and after pruning, pruning degree, and different pruning methods. The results showed that the performance of the ResNet-based sunflower seed classification model using global pruning was the least affected by pruning, with a 92% reduction in the number of parameters, the best accuracy is 0.56% better than non-pruned and 9.17% better than layer-wise pruning. These findings demonstrate that using the Iterative Magnitude Pruning algorithm can render the sunflower seed classification model lightweight with less performance loss. The reduction in computational resources through model compression reduces the cost of sunflower seed classification, making it more applicable to practical production, and this model can be used as a cost-effective alternative to key sunflower seed classification techniques in practical production.
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•CiteSpace analysis revealed very few studies on the toxicity of APs other than NP.•We propose a QSAR-ICE-SSD model for the HC5 derived for structurally similarity APs.•HC5 were ...derived from acute and chronic exposure on aquatic organisms for 10 APs.•HC5s derived from predicted data were within 2-fold of those from measured data.•An ERA was characterized using this method for APs to aquatic organisms in rivers.
Alkylphenols (APs) are ubiquitous and generally present in higher residue levels in the environment. The present work focuses on the development of a set of in silico models to predict the aquatic toxicity of APs with incomplete/unknown toxicity data in aquatic environments. To achieve this, a QSAR-ICE-SSD model was constructed for aquatic organisms by combining quantitative structure–activity relationship (QSAR), interspecies correlation estimation (ICE), and species sensitivity distribution (SSD) models in order to obtain the hazardous concentrations (HCs) of selected APs. The research indicated that the keywords “alkylphenol” and “nonylphenol” were most commonly studied. The selected ICE models were robust (R2: 0.70–0.99; p-value < 0.01). All models had a high reliability cross- validation success rates (>75%), and the HC5 predicted with the QSAR-ICE-SSD model was 2-fold than that derived with measured experimental data. The HC5 values demonstrated nearly linear decreasing trend from 2-MP to 4-HTP, while the decreasing trend from 4-HTP to 4-DP became shallower, indicates that the toxicity of APs to aquatic organisms increases with the addition of alkyl carbon chain lengths. The ecological risks assessment (ERA) of APs revealed that aquatic organisms were at risk from exposure to 4-NP at most river stations (the highest risk quotient (RQ) = 1.51), with the highest relative risk associated with 2.9% of 4-NP detected in 82.9% of the sampling sites. The targeted APs posed potential ecological risks in the Yongding and Beiyun River according to the mixture ERA. The potential application of QSAR-ICE-SSD models could satisfy the immediate needs for HC5 derivations without the need for additional in vivo testing.
Circular RNAs (circRNAs) play critical roles in regulating the radiosensitivity of various cancers, including esophageal squamous cell carcinoma (ESCC). This research aimed to explore the role and ...potential mechanism of hsa_circ_0014879 in regulating ESCC radioresistance. The levels of hsa_circ_0014879, microRNA-519-3p (miR-519-3p) and cell division cycle 25A (CDC25A) were measured using quantitative real-time PCR or western blot. Cell proliferation was evaluated by colony formation assay. Cell migration and invasion were assessed by transwell and scratch assays. The levels of epithelial-mesenchymal transition (EMT)-related proteins were detected by western blot. Xenograft assay was used to analyze the effect of hsa_circ_0014879 on radiosensitivity in vivo. The binding relationship among hsa_circ_0014879, miR-519-3p and CDC25A was confirmed by dual-luciferase reporter assay. Hsa_circ_0014879 and CDC25A were upregulated, whereas miR-519-3p was downregulated in radio-resistant ESCC tissues and cells. Depletion of hsa_circ_0014879 suppressed the proliferation, migration and invasion of radio-resistant ESCC cells. Hsa_circ_0014879 knockdown elevated radiosensitivity of radio-resistant cells by modulating miR-519-3p. Moreover, miR-519-3p enhanced the radiosensitivity of radio-resistant cells by targeting CDC25A. Also, hsa_circ_0014879 upregulated CDC25A via sponging miR-519-3p. Hsa_circ_0014879 silencing enhanced the radiosensitivity of ESCC via regulating the miR-519-3p/CDC25A pathway.
It has been recognized that ecological risk assessment based on traditional endpoints of toxicity are unable to provide adequate protection because some chemicals may affect reproductive fitness of ...aquatic organisms at much lower concentrations. In this paper, predicted no effect concentrations (PNECs) for 4-nonylphenol (NP) were derived based either on endpoints of survival, development, and growth or on some nonlethal biomarkers of reproduction, biochemical and molecular biology data. The PNECs derived from reproductive lesion ranged from 0.12 to 0.60 μg NP L–1, which was significantly lower than those derived from other endpoints. An assessment of ecological risks posed by NP to aquatic organisms in surface waters of China was conducted based on concentration levels of NP in 16 surface waters of 4 major river basins and PNECs derived from reproductive fitness by a tiered ecological risk assessment (ERA). The results showed that 14.2% and 76.5% of surface waters in China may have ecological risks resulting from reproductive fitness if the thresholds of protection for aquatic organisms were set up as 5% (HC5) and 1% (HC1), respectively. The risks were significantly greatest in the Yangtze River Basin than in other major river basins. In comparison with the risks assessed based on traditional endpoints, such as lethality, for those chemicals causing adverse effects on reproduction due to modulation of endocrine function, to be protective of ecosystem structure and function, lesser PNECs, based on sublethal effects of reproduction, were appropriate.
Abstract
Characteristic parameters of energy storage and loss in soft magnetic materials (SMMs), product
S
of initial susceptibility
χ
i
and resonance frequency
ω
r
and product
L
of maximum
χ
m
′
′
...and half width
Δ
ω
of imaginary part, were introduced in permalloy films. Expressions of characteristic parameters were derived from Landau–Lifshits–Gilbert equation with a general anisotropic free energy model. It was found
S
=
L
equals to intrinsic quantity of SMMs
Q
≡
γ
M
s
1
+
H
⊥
/
H
∥
, where
γ
is the gyromagnetic ratio,
M
s
is the saturation magnetization, and
H
⊥
and
H
∥
are mutually orthogonal effective magnetic fields. In the presence of eddy current, it was found
S
remains equal to
Q
while
L
<
Q
results from inhomogeneity of microwave magnetic field caused by eddy current. Moreover, a linear scale of
L
/
S
versus Gilbert damping factor
α
was found in permalloy films with different thicknesses. Hence, our findings provide a new perspective on energy storage and loss of SMMs.
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•FLCMs reduced cell density of zebrafish retinas approximately 12.6–46.1%.•FLCMs disrupted thyroid hormone levels and perturbed the hypothalamic-pituitary-thyroid axis.•TBG is the key ...protein that effected transport of thyroid hormones by FLCMs rather than TTR.•Disruption of the thyroid system signaling pathway ultimately affects visual motor response.•FLCMs with aliphatic ring structures represented higher T3 antagonistic potential.
Liquid crystal monomers (LCMs) are the raw material for liquid crystal displays, and their use is steadily increasing in electronic products. Recently, LCMs have been reported to be novel endocrine disrupting chemicals, however, the mechanisms underlying their potential for thyroid hormone disruption and visual toxicity are not well understood. In this study, six widely used fluorinated LCMs (FLCMs) were selected to determine putative mechanisms underlying FLCM-induced toxicity to the zebrafish thyroid and visual systems. Exposure to FLCMs caused damage to retinal structures and reduced cell density of ganglion cell layer, inner nuclear layer, and photoreceptor layer approximately 12.6–46.1%. Exposure to FLCMs also disrupted thyroid hormone levels and perturbed the hypothalamic-pituitary-thyroid axis by affecting key enzymes and protein in zebrafish larvae. A thyroid hormone-dependent GH3 cell viability assay supported the hypothesis that FLCMs act as thyroid hormone disrupting chemicals. It was also determined that FLCMs containing aliphatic ring structures may have a higher potential for T3 antagonism compared to FLCMs without an aliphatic ring. Molecular docking in silico suggested that FLCMs may affect biological functions of thyroxine binding globulin, membrane receptor integrin, and thyroid receptor beta. Lastly, the visual motor response of zebrafish in red- and green-light was significantly inhibited following exposure to FLCMs. Taken together, we demonstrate that FLCMs can act as thyroid hormone disruptors to induce visual dysfunction in zebrafish via several molecular mechanisms.
In this study, the risks to aquatic organisms posed by 12 commonly detected pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) that are extensively used in ...Bohai coastal region of China were examined. These were linear alkylbenzene sulfonate (LAS), nonylphenol (NP), diethylhexyl phthalate (DEHP), norfloxacin (NOR), sulfamethoxazole (SMX), erythromycin (ERY), bisphenol A (BPA), ofloxacin (OFL), carbamazepine (CBZ), naproxen (NPX), atenolol (ATL) and metoprolol (MET). Their relative risk was ranked based on the proximity between the medians of the reported effect concentrations and measured river or lake water concentrations. The surfactants (LAS) and endocrine disrupting chemicals NP (a breakdown product of the surfactant nonylphenol polyethoxylate) and DEHP (a plasticizer) were identified as posing the greatest risk from this range of chemicals. LAS had a hundred-fold higher risk than any of the pharmaceuticals. The highest risk ranked pharmaceuticals were all antibiotics. Zinc (Zn) and mercury (Hg) were added to the comparison as representative heavy metals. Zn posed a risk higher than all the organics. The risk posed by Hg was less than the surfactants but greater than the selected pharmaceuticals. Whereas LAS and DEHP could cause harmful effects to all the wildlife groups, NP and BPA posed the greatest risk to fish. Antibiotics showed the highest risk to algae. Spatial and temporal distributions of PPCPs and EDCs were conducted for risk identification, source analysis and seasonal change exploration. Municipal sewage effluent linked to urban areas was considered to be the major source of pharmaceuticals. With regard to seasonal influence the risk posed by LAS to the aquatic organisms was significantly affected by wet and dry seasonal change. The dilution effects were the common feature of LAS and ERY risks. The difference in LAS and ERY risk patterns along the rivers was mainly affected by the elimination process.
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•Surfactants (LAS) and EDCs (NP and DEHP) posed greater risk than pharmaceuticals.•Antibiotics showed higher risk to algae, invertebrates and the least risk to fish.•Municipal sewage was considered to be the major source for pharmaceuticals' risk.•The risk posed by LAS was significantly affected by wet and dry season change.•Risk difference of LAS and ETM in the rivers was affected by elimination process.
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