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1.
Proc Natl Acad Sci U S A ; 120(17): e2221459120, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37068247

RESUMO

Growing population and consumption pose unprecedented demands on food production. However, ammonia emissions mainly from food systems increase oceanic nitrogen deposition contributing to eutrophication. Here, we developed a long-term oceanic nitrogen deposition dataset (1970 to 2018) with updated ammonia emissions from food systems, evaluated the impact of ammonia emissions on oceanic nitrogen deposition patterns, and discussed the potential impact of nitrogen fertilizer overuse. Based on the chemical transport modeling approach, oceanic ammonia-related nitrogen deposition increased by 89% globally between 1970 and 2018, and now, it exceeds oxidized nitrogen deposition by over 20% in coastal regions including China Sea, India Coastal, and Northeastern Atlantic Shelves. Approximately 38% of agricultural nitrogen fertilizer was excessive, which corresponds to 15% of global oceanic ammonia-related nitrogen deposition. Policymakers and water quality managers need to pay increasingly more attention to ammonia associated with food production if the goal of reducing coastal nitrogen pollution is to be achieved for Sustainable Development Goals.


Assuntos
Amônia , Nitrogênio , Nitrogênio/análise , Amônia/análise , Fertilizantes/análise , Agricultura , China , Qualidade da Água , Solo
2.
Mol Biol Evol ; 41(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38723179

RESUMO

Despite traditional beliefs of orthologous genes maintaining similar functions across species, growing evidence points to their potential for functional divergence. C-repeat binding factors/dehydration-responsive element binding protein 1s (CBFs/DREB1s) are critical in cold acclimation, with their overexpression enhancing stress tolerance but often constraining plant growth. In contrast, a recent study unveiled a distinctive role of rice OsDREB1C in elevating nitrogen use efficiency (NUE), photosynthesis, and grain yield, implying functional divergence within the CBF/DREB1 orthologs across species. Here, we delve into divergent molecular mechanisms of OsDREB1C and AtCBF2/3/1 by exploring their evolutionary trajectories across rice and Arabidopsis genomes, regulatomes, and transcriptomes. Evolutionary scrutiny shows discrete clades for OsDREB1C and AtCBF2/3/1, with the Poaceae-specific DREB1C clade mediated by a transposon event. Genome-wide binding profiles highlight OsDREB1C's preference for GCCGAC compared to AtCBF2/3/1's preference for A/GCCGAC, a distinction determined by R12 in the OsDREB1C AP2/ERF domain. Cross-species multiomic analyses reveal shared gene orthogroups (OGs) and underscore numerous specific OGs uniquely bound and regulated by OsDREB1C, implicated in NUE, photosynthesis, and early flowering, or by AtCBF2/3/1, engaged in hormone and stress responses. This divergence arises from gene gains/losses (∼16.7% to 25.6%) and expression reprogramming (∼62.3% to 66.2%) of OsDREB1C- and AtCBF2/3/1-regulated OGs during the extensive evolution following the rice-Arabidopsis split. Our findings illustrate the regulatory evolution of OsDREB1C and AtCBF2/3/1 at a genomic scale, providing insights on the functional divergence of orthologous transcription factors following gene duplications across species.


Assuntos
Arabidopsis , Oryza , Fatores de Transcrição , Oryza/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Evolução Molecular , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
3.
Proc Natl Acad Sci U S A ; 119(14): e2121998119, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-35344440

RESUMO

SignificanceAgricultural systems are already major forces of ammonia pollution and environmental degradation. How agricultural ammonia emissions affect the spatio-temporal patterns of nitrogen deposition and where to target future mitigation efforts, remains poorly understood. We develop a substantially complete and coherent agricultural ammonia emissions dataset in nearly recent four decades, and evaluate the relative role of reduced nitrogen in total nitrogen deposition in a spatially explicit way. Global reduced nitrogen deposition has grown rapidly, and will occupy a greater dominant position in total nitrogen deposition without future ammonia regulations. Recognition of agricultural ammonia emissions on nitrogen deposition is critical to formulate effective policies to address ammonia related environmental challenges and protect ecosystems from excessive nitrogen inputs.


Assuntos
Poluentes Atmosféricos , Amônia , Agricultura , Poluentes Atmosféricos/análise , Amônia/análise , Ecossistema , Monitoramento Ambiental , Poluição Ambiental , Nitrogênio/análise
4.
Nucleic Acids Res ; 50(D1): D1244-D1254, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34606616

RESUMO

T-cell receptors (TCRs) and B-cell receptors (BCRs) are critical in recognizing antigens and activating the adaptive immune response. Stochastic V(D)J recombination generates massive TCR/BCR repertoire diversity. Single-cell immune profiling with transcriptome analysis allows the high-throughput study of individual TCR/BCR clonotypes and functions under both normal and pathological settings. However, a comprehensive database linking these data is not yet readily available. Here, we present the human Antigen Receptor database (huARdb), a large-scale human single-cell immune profiling database that contains 444 794 high confidence T or B cells (hcT/B cells) with full-length TCR/BCR sequence and transcriptomes from 215 datasets. All datasets were processed in a uniform workflow, including sequence alignment, cell subtype prediction, unsupervised cell clustering, and clonotype definition. We also developed a multi-functional and user-friendly web interface that provides interactive visualization modules for biologists to analyze the transcriptome and TCR/BCR features at the single-cell level. HuARdb is freely available at https://huarc.net/database with functions for data querying, browsing, downloading, and depositing. In conclusion, huARdb is a comprehensive and multi-perspective atlas for human antigen receptors.


Assuntos
Bases de Dados Genéticas , Receptores de Antígenos de Linfócitos B/classificação , Receptores de Antígenos de Linfócitos T/classificação , Software , Linfócitos B , Humanos , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Análise de Célula Única , Transcriptoma/genética , Recombinação V(D)J/genética
5.
Acta Paediatr ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714365

RESUMO

AIM: Few studies have assessed the association between weight changes from childhood to adulthood and cardiometabolic factors in adulthood. The aim of this study was to explore the relationships between weight changes from childhood to adulthood and cardiometabolic factors in adulthood using national Chinese data. METHODS: We included 649 participants from the China Health and Nutrition Survey from 1989 to 2009 and divided them into four groups by their body mass index from 6 to 37 years of age. They were selected using multistage random cluster sampling from 15 areas with large variations in economic and social development. Poisson regression models assessed associations between weight status changes and cardiometabolic outcomes in adulthood. RESULTS: The risk of multiple abnormal cardiometabolic outcomes in adulthood was increased in the 126 subjects with normal weight in childhood but overweight or obesity in adulthood and the 28 with obesity at both ages, compared to the 462 with normal weight at both ages. There was insufficient evidence to demonstrate that the 33 who had weight issues as children, but not as adults, had an increased risk. CONCLUSION: Being overweight or obese in both childhood and adulthood or during adulthood only increased the risk of abnormal cardiometabolic outcomes in adulthood. Larger studies need to investigate whether weight problems in childhood, but not adulthood, increase the risk.

6.
Br J Nutr ; 129(1): 166-174, 2023 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-35264258

RESUMO

Mounting evidence suggests that the first few months of life are critical for the development of obesity. The relationships between the timing of solid food introduction and the risk of childhood obesity have been examined previously; however, evidence for the association of timing of infant formula introduction remains scarce. This study aimed to examine whether the timing of infant formula introduction is associated with growth z-scores and overweight at ages 1 and 3 years. This study included 5733 full-term (≥ 37 gestational weeks) and normal birth weight (≥ 2500 and < 4000 g) children in the Born in Guangzhou Cohort Study, a prospective cohort study with data collected at 6 weeks, 6, 12 and 36 months. Compared with infant formula introduction at 0-3 months, introduction at 4-6 months was associated with the lower BMI, weight-for-age and weight-for-length z-scores at 1 and 3 years old. Also, introduction at 4-6 months was associated with the lower odds of at-risk of overweight at age 1 (adjusted OR 0·72, 95 % CI 0·55, 0·94) and 3 years (adjusted OR 0·50, 95 % CI 0·30, 0·85). Introduction at 4-6 months also decreased the odds of overweight at age 1 year (adjusted OR 0·42, 95 % CI 0·21, 0·84) but not at age 3 years. Based on our findings, compared with introduction within the first 3 months, introduction at 4-6 months has a reduction on later high BMI risk and at-risk of overweight. However, these results need to be replicated in other well-designed studies before more firm recommendations can be made.


Assuntos
Sobrepeso , Obesidade Infantil , Lactente , Feminino , Humanos , Criança , Pré-Escolar , Sobrepeso/epidemiologia , Estudos de Coortes , Obesidade Infantil/epidemiologia , Obesidade Infantil/prevenção & controle , Fórmulas Infantis , Índice de Massa Corporal , Estudos Prospectivos , Aleitamento Materno
7.
Environ Sci Technol ; 57(35): 13124-13135, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37616592

RESUMO

Ammonia (NH3) is critical to the nitrogen cycle and PM2.5 formation, yet a great deal of uncertainty exists in its urban emission quantifications. Model-underestimated NH3 concentrations have been reported for cities, yet few studies have provided an explanation. Here, we explore reasons for severe WRF-Chem model underestimations of NH3 concentrations in Beijing in August 2018, including simulated gas-particle partitioning, meteorology, regional transport, and emissions, using spatially refined (3 km resolution) NH3 emission estimates in the agricultural sector for Beijing-Tianjin-Hebei and in the traffic sector for Beijing. We find that simulated NH3 concentrations are significantly lower than ground-based and satellite observations during August in Beijing, while wintertime underestimations are much more moderate. Further analyses and sensitivity experiments show that such discrepancies cannot be attributed to factors other than biases in NH3 emissions. Using site measurements as constraints, we estimate that both agricultural and non-agricultural NH3 emission totals in Beijing shall increase by ∼5 times to match the observations. Future research should be performed to allocate underestimations to urban fertilizer, power, traffic, or residential sources. Dense and regular urban NH3 observations are necessary to constrain and validate bottom-up inventories and NHx simulation.


Assuntos
Agricultura , Amônia , Pequim , China , Cidades
8.
Appl Opt ; 62(18): 4766-4776, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37707250

RESUMO

Baseline correction is necessary for the qualitative and quantitative analysis of samples because of the existence of background fluorescence interference in Raman spectra. The asymmetric least squares (ALS) method is an adaptive and automated algorithm that avoids peak detection operations along with other user interactions. However, current ALS-based improved algorithms only consider the smoothness configuration of regions where the signals are greater than the fitted baseline, which results in smoothing distortion. In this paper, an asymmetrically reweighted penalized least squares method based on spectral estimation (SEALS) is proposed. SEALS considers not only the uniform distribution of additive noise along the baseline but also the energy distribution of the signal above and below the fitted baseline. The energy distribution is estimated using inverse Fourier and autoregressive models to create a spectral estimation kernel. This kernel effectively optimizes and balances the asymmetric weight assigned to each data point. By doing so, it resolves the issue of local oversmoothing that is typically encountered in the asymmetrically reweighted penalized least squares method. This oversmoothing problem can negatively impact the iteration depth and accuracy of baseline fitting. In comparative experiments on simulated spectra, SEALS demonstrated a better baseline fitting performance compared to several other advanced baseline correction methods, both under moderate and strong fluorescence backgrounds. It has also been proven to be highly resistant to noise interference. When applied to real Raman spectra, the algorithm correctly restored the weak peaks and removed the fluorescence peaks, demonstrating the effectiveness of this method. The computation time of the proposed method was approximately 0.05 s, which satisfies the real-time baseline correction requirements of practical spectroscopy acquisition.

9.
BMC Public Health ; 23(1): 111, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36647024

RESUMO

PURPOSE: The primary objective of this study was to evaluate knowledge and behavior of medication use among guardians of left-behind children (LBC) and non-left-behind children (NLBC). METHODS: A cross-sectional study was conducted in Chengdu, the major city of southwestern China from May 2020 to August 2020. A logistic regression model was conducted to assess medication-related knowledge and behavior of guardians between the LBC group and NLBC group, adjusted for confounders. Stratified analysis was further performed. RESULTS: The overall mean scores for knowledge and for behavior were 20.22 (standard deviation = 4.472) and 15.77 (standard deviation = 3.604), respectively. No significant difference was found in medication-related knowledge and behavior scores between LBC and NLBC guardians (P > 0.05). A significant difference was only observed after adjusting for past medical history and history of present illness (HPI). CONCLUSION: There was no significant difference in the awareness and behavior of medication use between guardians of LBC and NLBC in this study, having more contact with the doctor was an effective method of health education that could possibly improve their health literacy.


Assuntos
População Rural , Humanos , Criança , Estudos Transversais , China , Modelos Logísticos
10.
BMC Anesthesiol ; 23(1): 204, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37312027

RESUMO

BACKGROUND: Patients who undergo gastrointestinal endoscopy often require propofol-based sedation combined with analgesics. At present, the efficacy and safety of esketamine as an adjunct to propofol for sedation during endoscopic procedures in patients remains controversial. Moreover, there is no universal agreement regarding the appropriate dose of esketamine supplementation. This study aimed to assess the efficacy and safety of esketamine as an adjunct to propofol for sedation during endoscopic procedures in patients. METHODS: Seven electronic databases and three clinical trial registry platforms were searched and the deadline was February 2023. Randomized controlled trials (RCTs) evaluating the efficacy of esketamine for sedation were included by two reviewers. Data from the eligible studies were combined to calculate the pooled risk ratio or standardized mean difference. RESULTS: Eighteen studies with 1962 esketamine participants were included in the analysis. As an adjunct to propofol, the administration of esketamine reduced the recovery time compared to normal saline (NS). However, there was no significant difference between the opioids group and ketamine group. For propofol dosage, the administration of esketamine required a lower propofol dosage compared to the NS group and opioids group].For complications, the esketamine group had fewer complications compared to the NS group and opioid group in patients, but there were no significant differences between the esketamine group and ketamine group. Notably, the coadministration of esketamine was associated with a higher risk of visual disturbance compared to the NS group. In addition, we used subgroup analysis to investigate whether 0.2-0.5 mg/kg esketamine was effective and tolerable for patients. CONCLUSION: Esketamine as an adjunct to propofol, is an appropriate effective alternative for sedation in participants undergoing gastrointestinal endoscopy. However, considering the possibility of its psychotomimetic effects, esketamine should be used with caution.


Assuntos
Ketamina , Propofol , Humanos , Ketamina/efeitos adversos , Analgésicos Opioides , Propofol/efeitos adversos , Endoscopia Gastrointestinal/efeitos adversos , Solução Salina
11.
Anim Biotechnol ; 34(1): 77-84, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34138682

RESUMO

This study was conducted to examine the influence of uni and bilateral castration on growth performance and lipid metabolism in yellow cattle. Eighteen 9-month-old healthy yellow cattle (average body weight 184.03 ± 4.09 kg) were selected and divided into three groups: The uncastrated cattle (C), half castrated cattle (HC) and full castrated cattle (FC). The results showed that the growth rate of FC group was significantly reduced as compared to HC and C group, while the feed to gain ratio exhibited an opposite trend. The concentrations of triglycerides (TG), low-density lipoprotein cholesterol (LDL) and high-density lipoprotein (HDL) were increased significantly in FC group from day 60 to the end of the trial compared to HC and control groups. Serum testosterone concentration of FC group cattle was decreased from day 60 to 120 d of the trial compared to HC and control groups. The concentration of the lauric acid in FC cattle was significantly increased from the HC and control groups. In the FC group, the acetyl-CoA carboxylase alpha (ACACA), ACC and fatty acid synthase (FAS) gene expression levels were significantly higher compared to control and HC groups. Our results of this study suggest that bilateral castration increased the lipid metabolism and fatty acid composition compared to unilateral castrated and un-castrated cattle.HighlightsBilateral castration alters the growth performance in yellow cattle.Bilateral castration alters hormones levels and lipid metabolites levels in serum.Bilateral castration improves the lipid metabolism and fatty acid profile.


Assuntos
Ácidos Graxos , Metabolismo dos Lipídeos , Bovinos , Animais , Metabolismo dos Lipídeos/genética , Castração , Triglicerídeos , Peso Corporal
12.
Int J Mol Sci ; 24(8)2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37108734

RESUMO

Extremely low frequency electromagnetic field (ELF-EMF) exists widely in public and occupational environments. However, its potential adverse effects and the underlying mechanism on nervous system, especially behavior are still poorly understood. In this study, zebrafish embryos (including a transfected synapsin IIa (syn2a) overexpression plasmid) at 3 h post-fertilization (hpf) were exposed to a 50-Hz magnetic field (MF) with a series of intensities (100, 200, 400 and 800 µT, respectively) for 1 h or 24 h every day for 5 days. Results showed that, although MF exposure did not affect the basic development parameters including hatching rate, mortality and malformation rate, yet MF at 200 µT could significantly induce spontaneous movement (SM) hypoactivity in zebrafish larvae. Histological examination presented morphological abnormalities of the brain such as condensed cell nucleus and cytoplasm, increased intercellular space. Moreover, exposure to MF at 200 µT inhibited syn2a transcription and expression, and increased reactive oxygen species (ROS) level as well. Overexpression of syn2a could effectively rescue MF-induced SM hypoactivity in zebrafish. Pretreatment with N-acetyl-L-cysteine (NAC) could not only recover syn2a protein expression which was weakened by MF exposure, but also abolish MF-induced SM hypoactivity. However, syn2a overexpression did not affect MF-increased ROS. Taken together, the findings suggested that exposure to a 50-Hz MF inhibited spontaneous movement of zebrafish larvae via ROS-mediated syn2a expression in a nonlinear manner.


Assuntos
Campos Magnéticos , Peixe-Zebra , Animais , Campos Eletromagnéticos/efeitos adversos , Larva/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Peixe-Zebra/metabolismo , Sinapsinas
13.
Int J Mol Sci ; 24(6)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36982630

RESUMO

Deep brain stimulation (DBS)-through a surgically implanted electrode to the subthalamic nucleus (STN)-has become a widely used therapeutic option for the treatment of Parkinson's disease and other neurological disorders. The standard conventional high-frequency stimulation (HF) that is currently used has several drawbacks. To overcome the limitations of HF, researchers have been developing closed-loop and demand-controlled, adaptive stimulation protocols wherein the amount of current that is delivered is turned on and off in real-time in accordance with a biophysical signal. Computational modeling of DBS in neural network models is an increasingly important tool in the development of new protocols that aid researchers in animal and clinical studies. In this computational study, we seek to implement a novel technique of DBS where we stimulate the STN in an adaptive fashion using the interspike time of the neurons to control stimulation. Our results show that our protocol eliminates bursts in the synchronized bursting neuronal activity of the STN, which is hypothesized to cause the failure of thalamocortical neurons (TC) to respond properly to excitatory cortical inputs. Further, we are able to significantly decrease the TC relay errors, representing potential therapeutics for Parkinson's disease.


Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , Núcleo Subtalâmico , Animais , Doença de Parkinson/terapia , Estimulação Encefálica Profunda/métodos , Neurônios/fisiologia , Simulação por Computador
14.
Bioinformatics ; 37(17): 2741-2743, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-33532827

RESUMO

SUMMARY: With the advance of genomic sequencing techniques, chromatin accessible regions, transcription factor binding sites and epigenetic modifications can be identified at genome-wide scale. Conventional analyses focus on the gene regulation at proximal regions; however, distal regions are usually less focused, largely due to the lack of reliable tools to link these regions to coding genes. In this study, we introduce RAD (Region Associated Differentially expressed genes), a user-friendly web tool to identify both proximal and distal region associated differentially expressed genes (DEGs). With DEGs and genomic regions of interest (gROI) as input, RAD maps the up- and down-regulated genes associated with any gROI and helps researchers to infer the regulatory function of these regions based on the distance of gROI to differentially expressed genes. RAD includes visualization of the results and statistical inference for significance. AVAILABILITY AND IMPLEMENTATION: RAD is implemented with Python 3.7 and run on a Nginx server. RAD is freely available at https://labw.org/rad as online web service. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

15.
Opt Lett ; 47(18): 4608-4611, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36107044

RESUMO

The magneto-optical resonance response of sodium atoms generated by a high-energy solid-state pulse Nd:YAG laser is studied in different external magnetic fields. We investigate the resonance fluorescence signal of sodium atoms in a simulated sea fog environment based on the laser-induced plasma (LIP) effect. By ionizing an NaCl solution spray to generate sodium atoms in an atmospheric environment, we build a Bell-Bloom magneto-optical resonance system under laboratory conditions. With the help of laser-induced breakdown spectroscopy (LIBS) and extinction spectrum, we obtain sodium atoms with a lifetime of 250 µs. A narrowband tunable continuous wave (CW) 589-nm laser tuned at the D2 line with a modulation frequency around the Larmor frequency is used as the pump beam to polarize sodium atoms in the test magnetic field. We find that the magneto-optical resonance signals vary with different external magnetic fields and the positions of the resonance signal are consistent with the theoretical values. An intrinsic magnetometric sensitivity of 620.4 pT in a 1-Hz bandwidth is achieved.

16.
Pediatr Allergy Immunol ; 33(1): e13703, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34806795

RESUMO

BACKGROUND: Maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) have been linked to offspring allergic disorders. However, associations observed in previous studies were inconsistent and might be confounded by unmeasured familial factors. We aimed to examine the associations of maternal weight with offspring allergic disorders by using paternal BMI as a negative control exposure. METHODS: We included the data of 10,522 children from the Born in Guangzhou Cohort Study, 2012-2017. Data on maternal weight were obtained from questionnaires and obstetric records, and paternal weight was collected from questionnaires. Atopic dermatitis (AD) and wheezing at the age of 1 year were defined according to parent-reported physician diagnosis. Risk ratios (RRs) were estimated by log-binominal regression with mutual adjustment for maternal and paternal weight status. RESULTS: By the age of 1 year, 16.2% and 7.9% of children were diagnosed with AD and wheezing, respectively. While maternal pre-pregnancy BMI as a continuous variable was not associated with offspring AD, infants of pre-pregnancy overweight/obese women had a higher risk of AD than those born to normal weight women; no such associations were observed for paternal BMI. Both maternal pre-pregnancy BMI and paternal BMI were positively associated with the risk of offspring wheezing. Maternal GWG was not associated with AD or wheezing. CONCLUSIONS: Our findings suggest that maternal pre-pregnancy overweight/obesity might increase the risk of infant AD via intrauterine mechanisms, whereas the association with wheezing might be confounded by uncontrolled familial factors. These findings may be valuable in early-life prevention for offspring allergic diseases.


Assuntos
Dermatite Atópica , Ganho de Peso na Gestação , Peso ao Nascer , Índice de Massa Corporal , Criança , Estudos de Coortes , Dermatite Atópica/epidemiologia , Feminino , Humanos , Lactente , Gravidez , Sons Respiratórios
17.
Ecotoxicol Environ Saf ; 224: 112704, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34455183

RESUMO

Di (2-ethylhexyl) phthalate (DEHP) and extremely low-frequency electromagnetic fields (ELF-EMFs) exist far and wide in our surroundings. Studies have reported that both of DEHP and ELF-EMFs could promote cell proliferation which is related with adverse bioeffects. In this study, we investigated whether there is the combined effect between DEHP and 50-Hz magnetic fields (MFs) on cell proliferation in human amniotic (FL) cells. Results revealed that the low-concentration DEHP (1 µM) could promote FL cell proliferation, whereas the high-dose DEHP (100 µM) inhibited cell proliferation. When FL cells were treated jointly by a 50-Hz, 0.2-mT MF and 0.1 µM DEHP, the proliferation rate of cells was significantly higher than that of single factor exposure. Additionally, co-exposure to under-threshold MF and DEHP could cooperatively activate protein kinase B (Akt), sphingosine kinase 1 (SphK1) and extracellular signal regulated kinase (ERK) in a cascade manner, and finally mediate cell proliferation. Taken together, the findings of this study indicated that the co-exposure to under-threshold MF and DEHP could jointly promote cell proliferation through activating proliferation-related signal pathway, which warned us that it should be cautious about assessing the underlying health hazards of co-exposure to MFs and DEHP at under-threshold levels.

18.
Appl Opt ; 59(2): 552-557, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32225340

RESUMO

The defect properties of CH3NH3PbI3 solar cells with efficiencies ranging from 7.70% to 12.51% were investigated using admittance spectroscopy measurements. Trap levels of the same kind with activation energies varied in the range of 0.16-0.23 eV above the valence band were found for different samples and identified as an interface-type defect. Moreover, the defect parameters, including the capture cross section of the holes, capture lifetime of the holes, and defect density, were extracted, and their relationships with the cell efficiencies were investigated. The results indicated that, compared with other parameters, defect density is a critical factor for CH3NH3PbI3 solar cell performance.

19.
Sensors (Basel) ; 19(9)2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31086090

RESUMO

The inductive proximity sensor (IPS) is applicable to displacement measurements in the aviation field due to its non-mechanical contact, safety, and durability. IPS can increase reliability of position detection and decrease maintenance cost of the system effectively in aircraft applications. Nevertheless, the specialty in the aviation field proposes many restrictions and requirements on the application of IPS, including the temperature drift effect of the resistance component of the IPS sensing coil. Moreover, reliability requirements of aircrafts restrict the use of computational-intensive algorithms and avoid the use of process control components. Furthermore, the environment of airborne electronic equipment restricts measurements driven by large current and proposes strict requirements on emission tests of radio frequency (RF) energy. For these reasons, a differential structured IPS measurement method is proposed in this paper. This measurement method inherits the numerical separation of the resistance and inductance components of the IPS sensing coil to improve the temperature adaptation of the IPS. The computational complexity is decreased by combining the dimension-reduced look-up table method to prevent the use of process control components. The proposed differential structured IPS is equipped with a differential structure of distant and nearby sensing coils to increase the detection accuracy. The small electric current pulse excitation decreases the RF energy emission. Verification results demonstrate that the differential structured IPS realizes the numerical decoupling calculation of the vector impedance of the sensing coil by using 61 look-up table units. The measuring sensitivity increased from 135.5 least significant bits (LSB)/0.10 mm of a single-sensing-coil structured IPS to 1201.4 LSB/0.10 mm, and the linear approximation distance error decreased from 99.376 µm to -3.240 µm. The proposed differential structured IPS method has evident comparative advantages compared with similar measuring techniques.

20.
Environ Sci Technol ; 51(9): 5017-5025, 2017 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-28350955

RESUMO

Ground-level ozone (O3), harmful to most living things, is produced from both domestic and foreign emissions of anthropogenic precursors. Previous estimates of the linkage from distant sources rely on the sensitivity approach (i.e., modeling the change of ozone concentrations that result from modifying precursor emissions) as well as the tagging approach (i.e., tracking ozone produced from specific O3 precursors emitted from one region). Here, for the first time, we tag all O3 precursors (i.e., nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOCs)) from East Asia and explicitly track their physicochemical evolution without perturbing the nonlinear O3 chemistry. We show that, even in summer, when intercontinental influence on ozone has typically been found to be weakest, nearly 3 parts per billion by volume (ppbv) seasonal average surface O3 over North America can be attributed to East Asian anthropogenic emissions, compared with 0.7 ppbv using the sensitivity approach and 0.5 ppbv by tagging reactive nitrogen oxides. Considering the acute effects of O3 exposure, approximately 670 cardiovascular and 300 respiratory premature mortalities within North America could be attributed to East Asia. CO and longer-lived VOCs, largely overlooked in previous studies, extend the influence of regional ozone precursors emissions and, thus, greatly enhance O3 attribution to source region.


Assuntos
Poluentes Atmosféricos , Ozônio/química , Óxidos de Nitrogênio , Estações do Ano , Estados Unidos , Compostos Orgânicos Voláteis
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