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1.
Environ Pollut ; 349: 123968, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38631448

ABSTRACT

Neonicotinoid insecticides (NEOs) have gained widespread usage as the most prevalent class of insecticides globally and are frequently detected in the environment, posing potential risks to biodiversity and human health. Wastewater discharged from wastewater treatment plants (WWTPs) is a substantial source of environmental NEOs. However, research tracking NEO variations in different treatment units at the WWTPs after being treated by the treatment processes remains limited. Therefore, this study aimed to comprehensively investigate the fate of nine parent NEOs (p-NEOs) and five metabolites in two municipal WWTPs using distinct treatment processes. The mean concentrations of ∑NEOs in influent (effluent) for the UNITANK, anaerobic-anoxic-oxic (A2/O), and cyclic activated sludge system (CASS) processes were 189 ng/L (195 ng/L), 173 ng/L (177 ng/L), and 123 ng/L (138 ng/L), respectively. Dinotefuran, imidacloprid, thiamethoxam, acetamiprid, and clothianidin were the most abundant p-NEOs in the WWTPs. Conventional wastewater treatment processes were ineffective in removing NEOs from wastewater (-4.91% to -12.1%), particularly major p-NEOs. Moreover, the behavior of the NEOs in various treatment units was investigated. The results showed that biodegradation and sludge adsorption were the primary mechanisms responsible for eliminating NEO. An anoxic or anaerobic treatment unit can improve the removal efficiency of NEOs during biological treatment. However, the terminal treatment unit (chlorination disinfection tank) did not facilitate the removal of most of the NEOs. The estimated total amount of NEOs released from WWTPs to receiving waters in the Pearl River of South China totaled approximately 6.90-42.6 g/d. These findings provide new insights into the efficiency of different treatment processes for removing NEOs in current wastewater treatment systems.


Subject(s)
Insecticides , Neonicotinoids , Waste Disposal, Fluid , Wastewater , Water Pollutants, Chemical , Wastewater/chemistry , Insecticides/analysis , Insecticides/metabolism , China , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/metabolism , Neonicotinoids/analysis , Neonicotinoids/metabolism , Environmental Monitoring
2.
J Hazard Mater ; 468: 133835, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38394895

ABSTRACT

While N, N'-substituted p-phenylenediamines (PPDs) and their quinone derivatives (PPDQs) have been widely detected in the environment, there is currently limited data on their occurrence in humans. In this study, we conducted the first serum analysis of two PPDs and PPDQs in the healthy and secondary nonalcoholic fatty liver disease (S-NAFLD) cohorts in South China. The concentrations of four oxidative stress biomarkers (OSBs), namely, 8-iso-prostaglandin F2α (8-PGF2α), 11ß-prostaglandin F2α (11-PGF2α), 15(R)-prostaglandin F2α (15-PGF2α), and 8-hydroxy-2'-deoxyguanosine in serum samples were also measured. Results showed that N-(1,3-dimethybutyl)-N'-phenyl-p-phenylenediamine (6PPD) quinone was the predominant target analytes both in the healthy and S-NAFLD cohorts, with the median concentrations of 0.13 and 0.20 ng/mL, respectively. Significant (p < 0.05) and positive correlations were found between 6PPD concentration and 8-PGF2α, 11-PGF2α, and 15-PGF2α in both the healthy and S-NAFLD cohorts, indicating that 6PPD may be associated with lipid oxidative damage. In addition, concentrations of 6PPD in serum were associated significantly linked with total bilirubin (ß = 0.180 µmol/L, 95%CI: 0.036-0.396) and direct bilirubin (DBIL, ß = 0.321 µmol/L, 95%CI: 0.035-0.677) related to hepatotoxicity. Furthermore, 8-PGF2α, 11-PGF2α, and 15-PGF2α mediated 17.1%, 24.5%, and 16.6% of 6PPD-associated DBIL elevations, respectively. Conclusively, this study provides novel insights into human exposure to and hepatotoxicity assessment of PPDs and PPDQs.


Subject(s)
Chemical and Drug Induced Liver Injury , Non-alcoholic Fatty Liver Disease , Humans , Quinones/toxicity , Oxidative Stress , 8-Hydroxy-2'-Deoxyguanosine , Bilirubin , Prostaglandins , Phenylenediamines/toxicity
3.
Sci Total Environ ; 913: 169674, 2024 Feb 25.
Article in English | MEDLINE | ID: mdl-38160827

ABSTRACT

Pomelo (Citrus grandis) is a highly popular and juicy member of the citrus family. However, little is known regarding the occurrence and distribution of pesticides in pomelo. In this study, we determined the levels of legacy (n = 25) and current-use pesticides (n = 2) in all parts of pomelo (i.e., epicarp, mesocarp, endocarp, pulp, and seed) and paired soil and leaf samples collected from two pomelo orchards in South China. At least one target pesticide was detected in the pomelo fruit, soil, and leaf samples, indicating that these pesticides were ubiquitous. The spatial distribution of the total concentration of pesticides in the pomelo parts was in the order of epicarp (216 ng/g) > mesocarp (9.50 ng/g) > endocarp (4.40 ng/g) > seed (3.80 ng/g) > pulp (1.10 ng/g), revealing different spatial distributions in pomelo. Principal component analysis was performed based on the concentrations of the target pesticides in the pulp and paired samples of epicarp, leaf, topsoil, and deep soil to examine the translocation pathway of the pesticides in pomelo. Close correlations were found among the target pesticides, and the pesticides in the pulp were mainly transferred from the epicarp, topsoil, or deep soil. We also explored the factors that affected such transport and found that the main translocation pathway of the non-systemic pesticide (i.e., buprofezin) into the pulp was the epicarp, whereas the systemic pesticide (i.e., pyriproxyfen) was mainly derived from the soil. The cumulative chronic dietary risks of all the pesticides resulting from pomelo consumption were much lower than the acceptable daily intake values for the general population. However, the prolonged risk of exposure to these pesticides should not be underestimated. The potential health risks posed by legacy and current-use pesticides, which are widely and frequently utilized, should be given increased attention.


Subject(s)
Citrus , Pesticide Residues , Pesticides , Humans , Pesticides/analysis , Fruit/chemistry , Soil , China , Seeds/chemistry , Pesticide Residues/analysis
4.
Asia Pac J Clin Nutr ; 32(4): 392-400, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38135474

ABSTRACT

BACKGROUND AND OBJECTIVES: We aimed to evaluate the associations between a combined healthy lifestyle during the second and third trimesters and offspring anthropometric outcomes in China. METHODS AND STUDY DESIGN: We examined these associations among 548 participants from nine community health centers and three hospitals in the North China cohort. A pregnant women's healthy lifestyle score (HLS) was constructed based on six lifestyle factors: smoking, alcohol consumption, physical activity, sedentary behavior, diet, and gestational weight gain. Anthropometric indicators at birth like birth weight (BW), head circumference (HC), and birth length (BL) were collected, and weight to head circumference ratio (WHC, kg/m), body mass index (BMI, kg/m2) and Ponderal Index (PI, kg/m3) were calculated. Multivariate linear and logistic regression models were used to examine the effects of HLS during the second and third trimesters on anthropometric outcomes at birth, respectively. RESULTS: In fully adjusted models, we found a negative association between second and third-trimester HLS and offspring HC and a positive relationship between second-trimester HLS and BL (p<0.05). Neonates with mothers in the highest HLS tertile had a 5.6% relatively lower HC and 2.3% relatively longer body length than women in the lowest tertile. Each additional unit in third-trimester HLS had an associated decrease in HC by 0.96 cm. None of the associations between HLS and BW, WHC, BMI, and PI of offspring were observed. CONCLUSIONS: A healthy lifestyle score may significantly impact offspring head circumference and body length, supporting the important role of healthy lifestyles in improving the health of offspring.


Subject(s)
Healthy Lifestyle , Life Style , Infant, Newborn , Pregnancy , Humans , Female , Prospective Studies , Birth Weight , Anthropometry
5.
Front Sports Act Living ; 5: 1307930, 2023.
Article in English | MEDLINE | ID: mdl-38152381

ABSTRACT

Background: We aimed to explore the independent associations between screen time and the risk of stroke among Chinese adults based on the China Health and Nutrition Survey (CHNS). Methods: Data on Chinese adults aged older than 40 years from the CHNS in during 2004-2009 were selected. A total of 4,587 individuals were included in 2009, including screen time and the risk of stroke. Simultaneously, we traced the previous screen time to 2004 for those with outcome measures in 2009 (n = 2,100). Basic information, lifestyle, and screen behavior were obtained through face-to-face interviews and self-completed questionnaires. Anthropometric data collected included blood pressure, body weight, height, hip circumference, and waist circumference. Fasting blood was obtained for measurements of lipid and glucose levels. Cross-sectional analysis and cohort analysis were both performed using multivariate logistic regression. Results: Of all participants, 3,004 (65.49%) participants spent more than 2 h per day on screen time. Taking the men who spent less than 2 h on screen per day as reference, the crude odds ratio (OR) of the high risk of stroke was 1.53 [95% confidence interval (CI), 1.20-1.95] for the men who spent 2-3 h per day on screen and 2.37 (95% CI, 1.78-3.16) for the men who spent more than 3 h per day on screen. This difference remained significant after adjusting for confounding factors. No association was observed among women. However, in the cohort analysis with screen time in 2006 as the independent variable, the association between screen time and stroke risk was found both in men [OR, 1.83 (95% CI, 1.19-2.82)] and women [OR, 1.48 (95% CI, 1.10-1.99)]). Conclusion: We found that the high screen time was associated with an increased stroke risk, which was pronounced in men, warranting a universal need to limit screen time in order to improve health.

6.
Food Nutr Res ; 672023.
Article in English | MEDLINE | ID: mdl-37808204

ABSTRACT

Background: Corn peptides, a novel food prepared from corn gluten meal (CGM) by enzymatic hydrolysis or microbial fermentation, have attracted considerable interest owing to their various bioactive properties. However, the underlying mechanism of corn peptides attenuate non-alcoholic fatty liver disease (NAFLD) remains unclear. Objective: This study aimed to investigate the effect of corn peptides in NAFLD and to decipher the underlying mechanisms. Design: NAFLD was induced by a high-fat diet (HFD) for 10 weeks. Corn peptides were administered during the period. Human hepatocellular carcinomas (HepG2) cells induced by free fatty acids were used for this mechanism study. Results: Corn peptides alleviated HFD-induced histopathological changes, disorders of lipid metabolism, and mitochondrial damage. Moreover, corn peptides blocked mitophagy suppression by HFD based on the increased LC3, ATG7 expressions, as well as decreased P62 levels. Corn peptides increased the expression of proteins involved in fatty acid ß-oxidation, such as PPARα and PGC-1α. Corn peptides also improved the Ser/Thr kinase PINK1 (PINK1) and the E3 ubiquitin ligase Parkin (Parkin) translocation to mitochondria, which is confirmed by immunofluorescence. Furthermore, stable knockdown of PINK1 by PINK1 SiRNA in HepG2 inhibited PINK1-Parkin-associated mitophagy and resulted in lipid accumulation. Conclusion: Corn peptides improved cell injury and ameliorated mitochondrial dysfunction and lipid accumulation via PINK1/Parkin-mediated autophagy in NAFLD. Thus, corn peptides could be a promising nutritional molecule with natural functions for preventing NAFLD.

7.
Sci Total Environ ; 901: 165935, 2023 Nov 25.
Article in English | MEDLINE | ID: mdl-37532038

ABSTRACT

Neonicotinoid insecticides (NEOs) as well as their metabolites are highly mobile on the subsurface and can potentially contaminate drinking water sources; however, their pollution status and fate in the drinking water system remains ambiguous. In this study, six parent NEOs and two characteristic metabolites were measured in drinking water source protection area (source water, n = 52) and two related drinking water treatment plants (DWTPs) (n = 88) located in the Dongguan section of the Pearl River. The ubiquitous of NEOs was observed in source water with the mean concentration of total NEOs (ΣNEOs) at 240 ng/L. Although advanced DWTP (A-DWTP; range: 26 % to 100 %) showed better removals of ΣNEOs and all individual NEOs rather than those in conventional DWTP (C-DWTP; range: -53 % to 28 %), the removals were still low for acetamiprid (ACE, 26 %), thiacloprid (THD, 59 %), thiamethoxam (THM, 56 %) and N-desmethyl-acetamiprid (N-dm-ACE, 45 %) in A-DWTP. Removal rates were positive in chlorination (48 %), final stage of sedimentation (F-Sed, 24 %), and granular activated carbon (GAC) filter effluent (19 %) in A-DWTP. It worthy to note that ΣNEOs has high negative removal rates at the start stage of sedimentation (S-Sed, -83 %), middle stage of sedimentation (M-Sed, -47 %), and sand filter effluent (-42 %) water in C-DWTP, which resulted in negative removals of ΣNEOs (-9.6 %), imidacloprid (IMI, -22 %), clothianidin (CLO, -37 %), flupyradifurone (FLU, -76 %), and N-dm-ACE (-29 %) in C-DWTP. Residual levels of NEOs were high in source water, and their low or negative removals in DWTPs should be highly concerning. Results would fill the existing knowledge gap of NEOs in aquatic environment and provide a scientific dataset for policy-making on pollution control and environmental protection.

8.
Sci Total Environ ; 885: 163898, 2023 Aug 10.
Article in English | MEDLINE | ID: mdl-37146797

ABSTRACT

Humans are exposed to neonicotinoid insecticides (NEOs) from various routes. Urine has been widely used to characterize the internal exposure levels of NEOs in humans. However, variable sampling methods can result in highly variable measurements of NEOs, potentially leading to misunderstanding of human exposure. In this study, we collected the first morning voids urine (FMVU), spot urine (SU), and 24 h urine (24hU) samples from 8 healthy adults during 7 consecutive days. The concentration, variability, and reproducibility of six parent NEOs (p-NEOs) and three NEOs metabolites (m-NEOs) were measured. Over 79 % of the urine samples had detectable levels of NEOs. Dinotefuran (DIN) and olefin-imidacloprid (of-IMI) were excreted in the highest concentration of p-NEO and m-NEO, respectively. All of the p-NEOs except thiacloprid (THD) and of-IMI were recommended as biomarkers for biomonitoring studies. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) were used to evaluate the temporal variability and reproducibility of urinary NEOs in SU, FMVU and 24hU, respectively. We observed low ICCs ranging from 0.016 to 0.39 for NEOs regardless of the sample types. However, the higher CV and lower ICC values observed in SU samples suggested lower reproducibility compared to FMVU and 24hU samples. Significant correlations of several NEOs between FMVU and 24hU were also observed in the current study. Considering the comparable concentrations and similarity between FMVU and 24hU, our study proposed possible biomarkers and indicated that the potential for FMVU samples to estimate adequately an individual's exposure to NEOs. Therefore, we suggested FMVU as a sampling strategy in future human biomonitoring studies, while multiple samples were recommended to detect exposure over time intervals of weeks or months.


Subject(s)
Insecticides , Adult , Humans , Reproducibility of Results , Neonicotinoids/urine , Insecticides/urine , Alkenes , Biomarkers
9.
Wei Sheng Yan Jiu ; 52(2): 239-245, 2023 Mar.
Article in Chinese | MEDLINE | ID: mdl-37062686

ABSTRACT

OBJECTIVE: To explore the dose-effect and mechanism of the protective effect of corn peptide(CP) on nonalcoholic fatty liver disease(NAFLD). METHODS: Seventy male SD rats were randomly divided into control group, model group, CP group, puerarin positive control group, low-, medium-, high-dose corn peptide group, the experiment started after 1 week of adaptive feeding. The control group and CP group were fed with ordinary feed and others were fed with high-fat feed, while the control group was given intragastric administration of purified water, the CP group and the low-, medium-, high-dose corn peptide group were given intragastric administration of corn peptide(800, 400, 600 and 800 mg/(kg·d), respectively), and the puerarin positive control group was given intragastric administration of 300 mg/(kg·d) of puerarin, for 10 weeks. The body weight and general condition of rats were recorded every week, after 10 weeks, the indexes of 7 groups were compared. RESULTS: Compared with the model group, the liver index(3.67, 3.29, 3.19 and 3.04, P<0.05) of the rats in the three doses of corn peptide groups decreased. The homeostasis model assessment of insulin resistance(13.66, 11.82, 11.55 and 10.53, P<0.05) decreased. The serum triglyceride(TG)(0.59, 0.42, 0.34 and 0.28, P<0.05), total cholesterol(TC)(2.57, 2.10, 1.67 and 1.46, P<0.05), free fatty acid(FFA)(0.66, 0.44, 0.40 and 0.36, P<0.05), and leptin(10.64, 9.87, 9.43 and 9.05, P<0.05) decreased. The serum interleukin-6(74.61, 61.66, 51.12 and 35.68, P<0.05) and tumor necrosis factor-α(100.18, 74.13, 67.44 and 48.46, P<0.05) decreased. The serum aspartate aminotransferase(41.38, 19.41, 14.98 and 8.44, P<0.05) and alanine aminotransferase(25.14, 13.10, 11.57 and 7.48, P<0.05) activity decreased. The liver TG(9.89, 5.55, 4.73 and 3.13, P<0.05), TC(1.73, 0.97, 0.80 and 0.50, P<0.05) and FFA(1.81, 1.11, 0.77 and 0.70, P<0.05) decreased. The serum malondialdehyde(MDA)(21.36, 15.24, 12.75 and 10.87, P<0.05) level and liver MDA(11.87, 8.27, 6.33 and 4.98, P<0.05) level decreased. The serum and liver superoxide dismutase and glutathione peroxidase activity increased(P<0.05), and the effect is related to the intervention dose of corn peptide. The size of the liver became smaller, the liver color gradually changed from light yellow to light red. CONCLUSION: Corn peptide has a certain preventive effect on NAFLD in rats, and the preventive effect of corn peptide is related to its intervention dose.


Subject(s)
Non-alcoholic Fatty Liver Disease , Rats , Male , Animals , Non-alcoholic Fatty Liver Disease/etiology , Non-alcoholic Fatty Liver Disease/prevention & control , Zea mays , Diet, High-Fat/adverse effects , Rats, Sprague-Dawley , Liver , Alanine Transaminase
10.
Environ Sci Technol ; 56(23): 17143-17152, 2022 12 06.
Article in English | MEDLINE | ID: mdl-36441562

ABSTRACT

Studies on neonicotinoid (NEO) exposure in pregnant women and fetuses are scarce, and transplacental transfer of these insecticides is unknown. In this study, parent NEOs (p-NEOs) and their metabolites (m-NEOs) were determined in 95 paired maternal (MS) and cord serum (CS) samples collected in southern China. Imidacloprid was the predominant p-NEO in both CS and MS samples, found at median concentrations of 1.84 and 0.79 ng/mL, respectively, whereas N-desmethyl-acetamiprid was the most abundant m-NEO in CS (median: 0.083 ng/mL) and MS (0.13 ng/mL). The median transplacental transfer efficiencies (TTEs) of p-NEOs and m-NEOs were high, ranging from 0.81 (thiamethoxam, THM) to 1.61 (olefin-imidacloprid, of-IMI), indicating efficient placental transfer of these insecticides. Moreover, transplacental transport of NEOs appears to be passive and structure-dependent: cyanoamidine NEOs such as acetamiprid and thiacloprid had higher TTE values than the nitroguanidine NEOs, namely, clothianidin and THM. Multilinear regression analysis revealed that the concentrations of several NEOs in MS were associated significantly with hematological parameters related to hepatotoxicity and renal toxicity. To our knowledge, this is the first analysis of the occurrence and distribution of NEOs in paired maternal-fetal serum samples.


Subject(s)
Insecticides , Pregnancy , Humans , Female , Insecticides/analysis , Placenta/chemistry , Neonicotinoids , Nitro Compounds
11.
Front Nutr ; 9: 914020, 2022.
Article in English | MEDLINE | ID: mdl-35789967

ABSTRACT

Objective: We aimed to investigate the association between fat mass to lean body mass ratio (RFL), percentage of body fat (PBF), and fat mass (FM) with mortality among middle-aged and elderly cancer patients without obesity. Methods: This prospective hospital-based cohort study comprised 3,201 patients with stage I to IV cancer aged 40 years or above (mean age: 58 years for female patients and 61 years for male patients; mean length of follow-up was 1.67 years; the maximal follow-up length was 6.42 years). FM and PBF were measured by bioelectrical impedance analysis (BIA). Cox proportional hazard models were used, and adjusted hazard ratios (HRs) were estimated. Results: We revealed a significant association between RFL and all-cause mortality among men aged ≥60 years after adjusting for confounders. Compared with those in the lowest tertile of RFL, elderly men in the medium and highest tertile had a 35 and 34% lower hazard of death from any cause, respectively. After additionally adjusted for C-reaction protein (CRP), HRs of medium and high tertile of RFL became short of statistical significance [medium tertile: adjusted HRs (95% CI) = 0.74 (0.46, 1.20); highest tertile: adjusted HRs (95% CI) = 0.84 (0.53, 1.33)]. Among elderly women, RFL was significantly related to all-cause mortality only when the additional adjustment for CRP [medium tertile: adjusted HRs (95% CI) = 2.08 (1.08, 4.01); highest tertile: adjusted HRs (95% CI) = 0.90 (0.45, 1.81)]. No significant association between RFL and all-cause mortality was observed among female participants or male participants aged less than 60 years. Conclusion: Our findings showed a significant non-linear association between RFL and all-cause mortality, which was observed only in elderly men, and might be attenuated by their inflammation state.

12.
IEEE Trans Neural Netw Learn Syst ; 33(8): 3387-3399, 2022 08.
Article in English | MEDLINE | ID: mdl-33531306

ABSTRACT

Biological systems under a parallel and spike-based computation endow individuals with abilities to have prompt and reliable responses to different stimuli. Spiking neural networks (SNNs) have thus been developed to emulate their efficiency and to explore principles of spike-based processing. However, the design of a biologically plausible and efficient SNN for image classification still remains as a challenging task. Previous efforts can be generally clustered into two major categories in terms of coding schemes being employed: rate and temporal. The rate-based schemes suffer inefficiency, whereas the temporal-based ones typically end with a relatively poor performance in accuracy. It is intriguing and important to develop an SNN with both efficiency and efficacy being considered. In this article, we focus on the temporal-based approaches in a way to advance their accuracy performance by a great margin while keeping the efficiency on the other hand. A new temporal-based framework integrated with the multispike learning is developed for efficient recognition of visual patterns. Different approaches of encoding and learning under our framework are evaluated with the MNIST and Fashion-MNIST data sets. Experimental results demonstrate the efficient and effective performance of our temporal-based approaches across a variety of conditions, improving accuracies to higher levels that are even comparable to rate-based ones but importantly with a lighter network structure and far less number of spikes. This article attempts to extend the advanced multispike learning to the challenging task of image recognition and bring state of the arts in temporal-based approaches to a novel level. The experimental results could be potentially favorable to low-power and high-speed requirements in the field of artificial intelligence and contribute to attract more efforts toward brain-like computing.


Subject(s)
Artificial Intelligence , Pattern Recognition, Visual , Humans , Neural Networks, Computer
13.
IEEE Trans Neural Netw Learn Syst ; 33(3): 1134-1146, 2022 03.
Article in English | MEDLINE | ID: mdl-33471768

ABSTRACT

Traditional neuron models use analog values for information representation and computation, while all-or-nothing spikes are employed in the spiking ones. With a more brain-like processing paradigm, spiking neurons are more promising for improvements in efficiency and computational capability. They extend the computation of traditional neurons with an additional dimension of time carried by all-or-nothing spikes. Could one benefit from both the accuracy of analog values and the time-processing capability of spikes? In this article, we introduce a concept of augmented spikes to carry complementary information with spike coefficients in addition to spike latencies. New augmented spiking neuron model and synaptic learning rules are proposed to process and learn patterns of augmented spikes. We provide systematic insights into the properties and characteristics of our methods, including classification of augmented spike patterns, learning capacity, construction of causality, feature detection, robustness, and applicability to practical tasks, such as acoustic and visual pattern recognition. Our augmented approaches show several advanced learning properties and reliably outperform the baseline ones that use typical all-or-nothing spikes. Our approaches significantly improve the accuracies of a temporal-based approach on sound and MNIST recognition tasks to 99.38% and 97.90%, respectively, highlighting the effectiveness and potential merits of our methods. More importantly, our augmented approaches are versatile and can be easily generalized to other spike-based systems, contributing to a potential development for them, including neuromorphic computing.


Subject(s)
Neural Networks, Computer , Neurons , Action Potentials/physiology , Learning , Neurons/physiology , Recognition, Psychology
14.
IEEE Trans Neural Netw Learn Syst ; 33(4): 1714-1726, 2022 04.
Article in English | MEDLINE | ID: mdl-33471769

ABSTRACT

Spiking neural networks (SNNs) are considered as a potential candidate to overcome current challenges, such as the high-power consumption encountered by artificial neural networks (ANNs); however, there is still a gap between them with respect to the recognition accuracy on various tasks. A conversion strategy was, thus, introduced recently to bridge this gap by mapping a trained ANN to an SNN. However, it is still unclear that to what extent this obtained SNN can benefit both the accuracy advantage from ANN and high efficiency from the spike-based paradigm of computation. In this article, we propose two new conversion methods, namely TerMapping and AugMapping. The TerMapping is a straightforward extension of a typical threshold-balancing method with a double-threshold scheme, while the AugMapping additionally incorporates a new scheme of augmented spike that employs a spike coefficient to carry the number of typical all-or-nothing spikes occurring at a time step. We examine the performance of our methods based on the MNIST, Fashion-MNIST, and CIFAR10 data sets. The results show that the proposed double-threshold scheme can effectively improve the accuracies of the converted SNNs. More importantly, the proposed AugMapping is more advantageous for constructing accurate, fast, and efficient deep SNNs compared with other state-of-the-art approaches. Our study, therefore, provides new approaches for further integration of advanced techniques in ANNs to improve the performance of SNNs, which could be of great merit to applied developments with spike-based neuromorphic computing.


Subject(s)
Neural Networks, Computer , Neurons , Recognition, Psychology
15.
Neural Netw ; 142: 205-212, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34023641

ABSTRACT

Efficient learning of spikes plays a valuable role in training spiking neural networks (SNNs) to have desired responses to input stimuli. However, current learning rules are limited to a binary form of spikes. The seemingly ubiquitous phenomenon of burst in nervous systems suggests a new way to carry more information with spike bursts in addition to times. Based on this, we introduce an advanced form, the augmented spikes, where spike coefficients are used to carry additional information. How could neurons learn and benefit from augmented spikes remains unclear. In this paper, we propose two new efficient learning rules to process spatiotemporal patterns composed of augmented spikes. Moreover, we examine the learning abilities of our methods with a synthetic recognition task of augmented spike patterns and two practical ones for image classification. Experimental results demonstrate that our rules are capable of extracting information carried by both the timing and coefficient of spikes. Our proposed approaches achieve remarkable performance and good robustness under various noise conditions, as compared to benchmarks. The improved performance indicates the merits of augmented spikes and our learning rules, which could be beneficial and generalized to a broad range of spike-based platforms.


Subject(s)
Models, Neurological , Neural Networks, Computer , Action Potentials , Learning , Neurons
18.
Environ Pollut ; 266(Pt 1): 115117, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32650159

ABSTRACT

Triclosan (TCS) and Triclocarbon (TCC) are chlorinated synthetic antimicrobial agents formaternal urinelated in quantities of consumer products. However, the biomonitoring of direct exposure reflection for fetuses are rare. In this study, we determine the concentrations of TCS and TCC in paired maternal serum, cord serum, maternal urine, and amniotic fluid samples collected from a cohort of 95 expecting mother-fetal pairs in Southern China. TCS and TCC are detected widely (detection rates: >76.9%) in maternal serum, cord serum, maternal urine, and amniotic fluid samples. TCS is found to be the predominant antimicrobial agent with median concentrations in maternal serum (1.5 ng/mL) and cord serum (1.8 ng/mL) that are one order of magnitude higher than those of tcc in maternal serum (0.085 ng/mL) and cord serum (0.052 ng/mL), respectively. Cord serum concentrations of tcs and tcc correlated well with the concentrations in maternal serum, which reflect the mothers' contribution to fetal exposure. The higher median ratio of cord serum/maternal serumTCS (0.95) compared to that of cord serum/maternal serumTCC (0.53) indicates high placental transmission ability of TCS. Moreover, the facility to penetrate the placental barrier and hard to depurate characteristics lead to the long residence of TCS in the fetal environment, causing great concern over the prenatal exposure risks during the critical window of fetal development. This study provides a novel contribution by increasing existing knowledge on the exposure assessment of TCS and TCC during pregnancy through the exploration of matched maternal-fetal samples.


Subject(s)
Carbanilides/analysis , Prenatal Exposure Delayed Effects , Triclosan/analysis , Amniotic Fluid/chemistry , China , Female , Humans , Pregnancy
19.
Environ Sci Technol ; 54(13): 8210-8220, 2020 07 07.
Article in English | MEDLINE | ID: mdl-32388996

ABSTRACT

Neonicotinoids (NEOs) are insecticides that are widely used around the world. Following exposure, NEOs get metabolized in human bodies. The biomarkers to assess human NEO exposure are not well described because of the lack of information on the metabolites of NEOs (m-NEOs). In this study, five m-NEOs including N-desmethyl-acetamiprid (N-dm-ACE), 5-hydroxy-imidacloprid (5-OH-IMI), olefin-imidacloprid (Of-IMI), 1-methyl-3-(tetrahydro-3-furylmethyl) guanidine (DIN-G), and 1-methyl-3-(tetrahydro-3-furylmethyl) (DIN-U) were measured in 275 urine samples collected from 10 cities in China. All of the m-NEOs were frequently detected in urine samples with the median concentrations ranging from 0.42 (DIN-G) to 1.02 (5-OH-IMI) ng/mL. The urinary concentrations of N-dm-ACE and 5-OH-IMI measured in China were higher than those reported from Japan and the USA. In comparison to the parent NEO (i.e., acetamiprid, ACE; imidacloprid, IMI; and dinotefuran, DIN) concentrations reported in the same set of samples by our research group, the median ratios of m-NEO to the corresponding parent NEO (m-NEO/NEO) ranged from 4.95 (DIN-G/DIN) to 37.7 (N-dm-ACE/ACE), indicating that NEOs are mainly present as metabolites rather than the parent forms. Furthermore, the ratio of Σm-NEOs/ΣNEOs was significantly (p < 0.01) higher in females than in males, suggesting that NEOs are more readily metabolized in females or females are more highly exposed to m-NEOs. To our knowledge, this is the first study to measure Of-IMI, DIN-G, and DIN-U levels in urine samples from China. We recommend biomonitoring studies to include N-dm-ACE, 5-OH-IMI, and DIN-U (and DIN-G) for clear understanding of human exposure to ACE, IMI, and DIN, respectively.


Subject(s)
Insecticides , Biological Monitoring , China , Female , Humans , Insecticides/analysis , Japan , Male , Neonicotinoids , Nitro Compounds
20.
Sci Total Environ ; 726: 138503, 2020 Jul 15.
Article in English | MEDLINE | ID: mdl-32320878

ABSTRACT

Benzophenone (BP)-type ultraviolet (UV) filters are widely used in personal care products. Some of them have been identified as endocrine disrupting chemicals. However, little is known about the occurrence of BP-type UV filters in paired maternal-fetal samples. In this study, we investigated the occurrence of eight BP-type UV filters in paired maternal-fetal samples collected from Southern China. Among target analytes, only benzophenone-3 (BP-3) was frequently (detection rate > 80%) detected in maternal-fetal samples, i.e., maternal serum (MS), cord serum (CS), maternal urine (MU) and amniotic fluid (AF). BP-3 was the dominant compound in MS (median: 0.14 ng/mL), CS (0.16) and AF (0.12); whereas MU was dominated by benzophenone-1 (BP-1, 2.85). The median CS/MS ratios (i.e., placental transfer rates) of 4-hydroxy benzophenone (4-OH-BP, 2.35), BP-1 (1.52), benzophenone-4 (BP-4, 1.06), and BP-3 (1.03) were higher than 1.0, suggesting that exposure levels of these chemicals in fetuses were greater than those in mothers. Significant positive correlations (r = 0.667, p < 0.001) of BP-3 concentrations were found between MS and CS, which suggested that MS could be an indicator of fetal exposure to BP-3. Furthermore, the CS/MS ratios of 4-OH-BP, BP-1, BP-3, and benzophenone-8 (BP-8) increased with decreasing molecular weight or log Kow. Passive diffusion may play an important role in placental transfer of these BP type UV filters. The MU/MSBP-3 ratio (5.86) was relatively higher than that of MU/MSBP-1 (0.89), which indicated that BP-3 excretes rapidly in urine. The present study documents the occurrence of eight BP-type UV filters in matched MS, CS, MU and AF samples for the first time in China.


Subject(s)
Endocrine Disruptors , Sunscreening Agents , Benzophenones , China , Female , Fetus , Humans , Pregnancy
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