In this paper, Mn-doped ZnS quantum dots (QDs) capped by a molecularly imprinted polymer (MIP) were synthesized. The results showed a high selectivity of the MIP-capped Mn-doped ZnS QDs toward the ...template molecule (4-nitrophenol) by QD fluorescence quenching. The application of MIP-capped Mn-doped ZnS QDs to the chemiluminescence (CL) system was also studied using a KIO4−H2O2 system. This application combines the good selectivity of MIP with the high sensitivity of CL. The linear range of this CL system is from 0.1 to 40 μM, and the detection limit (DL) for 4-nitrophenol in the water can reach 76 nM. The method was also used in the real water samples, and the recoveries can fall in the range of 91−96%.
This work provides a mechanistic insight into the effects of different type of N-doped carbon-supported catalysts on the synthesis of VAc by the acetylene method. The introduction of N-doping can ...enhance the adsorption of acetylene and acetic acid molecules onto the catalyst supports. The N6–3 surface which with three pyridinic-N shows the most adsorption stability for both acetylene and acetic acid molecules, and facilitates the synthesis of VAc efficiently. While the N6 surface which with the pyridinic-N is obstructive to the VAc formation.
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•The N-doping enhances the adsorption of acetylene and acetic acid molecules.•The activation barrier could be effectively lowered by a concerted TS1.•The N6–3 surface facilitates the VAc synthesis by acetylene method efficiently.
•Self-supported Pt-Ni(OH)2-Ni foam electrode was fabricated via hydrothermal synthesis method.•The electron sturcure and high-quality ohmic contact between Pt and Ni(OH)2 were investiged.•A novel ...ammonia–nitrogen sensor was fabricated based on Pt-Ni(OH)2-Ni foam electrode.•This sensor showed great detection performances.
In this work, Ni foam-supported Pt-Ni(OH)2 nanosheets (Pt-Ni(OH)2-Ni foam) was designed to construct a novel electrochemical sensor for detection of ammonia–nitrogen in water. Pt-Ni(OH)2-Ni foam was prepared via one step and in situ hydrothermal synthesis in chloroplatinic acid solution and Ni foam acted as Ni source and conductive substrate. The electrochemical measured results indicated that Pt-Ni(OH)2-Ni foam showed excellent catalytic activity to electrooxidation of ammonia due to great synergistic effect between Pt and Ni(OH)2. Furthermore, the constructed electrochemical sensor based on Pt-Ni(OH)2-Ni foam exhibited great detection ability to ammonia–nitrogen with the linear range from 0.05 μM to 600 μM. The limit of detection was 39.2 nM (Sensitivity/Noise = 3). The optimized electron sturcure and high-quality ohmic contact between Pt and Ni(OH)2 were main reasons of great performances of Pt-Ni(OH)2-Ni foam. This work provided a potential sensor for ammonia–nitrogen determination.
The widespread prevalence of coronavirus disease-2019 (COVID-19) which is caused by severe respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has resulted in a severe global public health ...emergency. However, there are no sensitive biomarkers to predict the disease prognosis of COVID-19 patients. Here, we have identified interleukin-8 (IL-8) as a biomarker candidate to predict different disease severity and prognosis of COVID-19 patients. While serum IL-6 become obviously elevated in severe COVID-19 patients, serum IL-8 was easily detectible in COVID-19 patients with mild syndromes. Furthermore, lL-8 levels correlated better than IL-6 levels with the overall clinical disease scores at different stages of the same COVID-19 patients. Thus, our studies suggest that IL-6 and IL-8 can be respectively used as biomarkers for severe COVID-19 patients and for COVID-19 disease prognosis.
We aimed to evaluate the exposure of neonates to polybrominated diphenyl ethers (PBDEs) from a primitive e-waste (obsolete electrical and electronic devices) recycling area, in Guiyu, China, and a ...control area, Chaonan, China, through umbilical cord blood (UCB), the health effects, and relevant factors. Questionnaires were addressed, and UCB was collected shortly after birth from 153 pregnant women between May and July 2007. Blood samples were prepared by liquid−liquid extracting methods. PBDE concentration was determined by gas chromatography/mass spectrometry in the electron capture negative ionization mode. The total PBDE concentration was higher in UCB samples from Guiyu than in Chaonan samples (median 13.84, range 1.14−504.97 ng g−1 lipid, vs 5.23, range 0.29−363.70 ng g−1 lipid) (p < 0.05). BDE-209 was the dominant PBDE congener, followed by BDE-47, -153, and -99. Residence in Guiyu, which is a site for e-waste recycling, involvment in e-waste recycling, and the residence also being used as a family workshop were significant factors contributing to PBDE exposure. PBDE levels significantly differed in neonates by normal birth and adverse birth outcomes including stillbirth, low birth weight, and premature delivery (p < 0.05). The neonates from Guiyu are exposed to high levels of PBDEs. Prenatal exposure to PBDEs may affect neonates’ health in Guiyu, which still needs to be evaluated in larger epidemiological studies.
Perfluorooctanoic acid (PFOA) has applications in numerous industrial and consumer products. The widespread prevalence of PFOA in humans demonstrated in recent studies has drawn considerable interest ...from the public. We aimed to evaluate the exposure of mothers to PFOA and the potential hazards to neonates in a primitive electronic waste recycling area, Guiyu, China, and a control area, Chaonan, China.
Our investigation included analyses of maternal serum samples, health effect examinations, and other relevant factors. Questionnaires were administered and maternal serum samples were collected for 167 pregnant women. Solid phase extraction method was used for all analytical sample preparation, and analyses were completed using high performance liquid chromatography tandem mass spectrometry method.
The PFOA concentration was higher in maternal serum samples from Guiyu than in samples from Chaonan (median 16.95, range 5.5–58.5ngmL−1; vs. 8.7, range 4.4–30.0ngmL−1; P<0.001). Residence in Guiyu, involvement in e-waste recycling, husband's involvement in e-waste and use of the family residence as workshop were significant factors contributing to PFOA exposure. Maternal PFOA concentrations were significantly different between normal births and adverse birth outcomes including premature delivery, term low birth weight, and stillbirths. After adjusting for potential confounders, PFOA was negatively associated with gestational age per lg-unit: β=−15.99days, 95% confidence interval (CI), −27.72 to −4.25, birth weight (per lg-unit: β=−267.3g, 95% CI, −573.27 to −37.18), birth length (per lg-unit: β=−1.91cm, 95% CI, −3.31 to −0.52), and Apgar scores (per lg-unit: β=−1.37, 95% CI, −2.42 to −0.32), but not associated with ponderal index.
Mothers from Guiyu were exposed to higher levels of PFOA than those from control areas. Prenatal exposure to PFOA was associated with decreased neonatal physical development and adverse birth outcomes.
► Prenatal PFOA exposure and adverse health effects in Guiyu was initially assessed. ► The pregnant women from Guiyu were exposed to high levels of PFOA. ► Maternal PFOA levels were different between normal births and adverse birth outcomes. ► Antenatal exposure to PFOA is associated with reduced body size, Apgar score, and gestational age.
Unregulated electronic-waste recycling results in serious environmental pollution of polycyclic aromatic hydrocarbons (PAHs) in Guiyu, China. We evaluated the body burden of seven carcinogenic PAHs ...and potential health risks for neonates. Umbilical cord blood (UCB) samples were collected from Guiyu (n=103), and the control area of Chaonan (n=80), China. PAHs in UCB were determined by gas chromatography/mass spectrometry. The median ∑7c-PAH concentration was 108.05ppb in UCB samples from Guiyu, vs. 79.36ppb in samples from Chaonan. Residence in Guiyu and longer cooking time of food during the gestation period were significant factors contributing to the ∑7c-PAH level. Benzoaanthracene (BaA), chrysene (Chr), and benzoapyrene (BaP) were found to correlate with reduced neonatal height and gestational age. Infants experiencing adverse birth outcomes, on the whole, displayed higher BaA, Chr, and BaP levels compared to those with normal outcomes. We conclude that maternal PAH exposure results in fetal accumulation of toxic PAHs, and that such prenatal exposure correlates with adverse effects on neonatal health.
Aiming at the problem that the rubber tapping robot finds it difficult to accurately detect the tapped area and locate the new tapping line for natural rubber trees due to the influence of the rubber ...plantation environment during the rubber tapping operation, this study proposes a method for detecting the tapped area and locating the new tapping line for natural rubber trees based on the improved mask region convolutional neural network (Mask RCNN). First, Mask RCNN was improved by fusing the attention mechanism into the ResNeXt, modifying the anchor box parameters, and adding a tiny fully connected layer branch into the mask branch to realize the detection and rough segmentation of the tapped area. Then, the fine segmentation of the existing tapping line was realized by combining edge detection and logic operation. Finally, the existing tapping line was moved down a certain distance along the center line direction of the left and right edge lines of the tapped area to obtain the new tapping line. The tapped area detection results of 560 test images showed that the detection accuracy, segmentation accuracy, detection average precision, segmentation average precision, and intersection over union values of the improved Mask RCNN were 98.23%, 99.52%, 99.6%, 99.78%, and 93.71%, respectively. Compared with other state-of-the-art approaches, the improved Mask RCNN had better detection and segmentation performance, which could better detect and segment the tapped area of natural rubber trees under different shooting conditions. The location results of 560 new tapping lines under different shooting conditions showed that the average location success rate of new tapping lines was 90% and the average location time was 0.189 s. The average values of the location errors in the
and
directions were 3 and 2.8 pixels, respectively, and the average value of the total location error was 4.5 pixels. This research not only provides a location method for the new tapping line for the rubber tapping robot but also provides theoretical support for the realization of rubber tapping mechanization and automation.
Primitive electronic waste (e-waste) recycling is ongoing in Guiyu, and thus toxic heavy metals may keep on threatening to the health of local children. Some related factors may contribute to the ...elevation of blood lead levels (BLLs) or blood cadmium levels (BCLs).
To investigate the children's BLLs and BCLs in Guiyu and Chendian as compare to discuss the effects of primitive e-waste recycling activities on children's health.
Two hundred and seventy-eight children less than 8 years who lived in Guiyu and Chendian were observed, and their BLLs and BCLs were determined by graphite atomizer absorption spectrophotometer. Questionnaire survey for risk factors was also performed and data were analyzed using spearman correlation analyses and logistic regression analyses.
Children living in Guiyu had significantly higher BLLs and BCLs as compared with those living in Chendian (
p<0.01). In Guiyu, 70.8% of children (109/154) had BLLs>10
μg/dL, and 20.1% of children (31/154) had BCLs>2
μg/L, compared with 38.7% of children (48/124) had BLLs>10
μg/dL and 7.3% of children (9/124) had BCLs>2
μg/L in Chendian (
p<0.01, respectively). We also observed a significant increasing trend in BLLs with increasing age in Guiyu (
p<0.01). Mean height of children in Guiyu was significantly lower than that in Chendian (
p<0.01). The risk factors related to children's BLLs and BCLs mainly included father's engagement in the work related to e-waste, children's residence in Guiyu and the amount of time that children played outside near the road everyday.
There are close relationships between the BLLs, BCLs in children and the primitive e-waste recycling activities in Guiyu. Environmental pollution, especially lead pollution, has threatened the health of children living around e-waste recycling site.
Informal electronic waste (e-waste) recycling results in serious environmental pollution of polybrominated diphenyl ethers (PBDEs) and heavy metals. This study explored whether there is an ...association between PBDEs, heavy metal and key growth- and development-related hormones in children from Guiyu, an e-waste area in southern China. We quantified eight PBDE congeners using gas chromatographic mass spectrometry, lead and cadmium utilizing graphite furnace atomic absorption spectrometry, three thyroids with radioimmunoassay and two types of growth hormones by an enzyme-linked immune-sorbent assay (ELISA) in 162 children, 4 to 6 years old, from Guiyu. In blood, median total PBDE was 189.99 ng/g lipid. Lead and cadmium concentrations in blood averaged 14.53±4.85 µg dL-1 and 0.77±0.35 µg L-1, respectively. Spearman partial correlation analysis illustrated that lead was positively correlated with BDE153 and BDE183. Thyroid-stimulating hormone (TSH) was positively correlated with almost all PBDE congeners and negatively correlated with insulin-like growth factor binding protein-3 (IGFBP-3), whereas free triiodothyronine (FT3) and free thyroxine (FT4) were negatively correlated with BDE154. However, no correlation between the hormones and blood lead or cadmium levels was found in this study. Adjusted multiple linear regression analysis showed that total PBDEs was negatively associated with FT3 and positively associated with TSH. Notably, FT4 was positively correlated with FT3, house functions as a workshop, and father's work involved in e-waste recycling and negatively correlated with vitamin consumptions. TSH was negatively related with FT4, paternal residence time in Guiyu, working hours of mother, and child bean products intake. IGFBP-3 was positively correlated with IGF-1 and house close to an e-waste dump. These results suggest that elevated PBDEs and heavy metals related to e-waste in Guiyu may be important risk factors for hormone alterations in children.
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