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1.
J Exp Child Psychol ; 243: 105918, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38569300

RESUMO

Fractions are the gatekeepers to advanced mathematics but are difficult to learn. One powerful learning mechanism is analogy, which builds fraction understanding on a pre-existing foundation of integer knowledge. Indeed, a short intervention that aligned fractions and integers on number lines improved children's estimates of fractions (Yu et al., 2022). The breadth and durability of such gains, however, are unknown, and analogies to other sources (such as percentages) may be equally powerful. To investigate this issue, we randomly assigned 109 fourth and fifth graders to one of three experimental conditions with different analogical sources (integers, percentages, or fractions) or a control condition. During training, children in the experimental conditions solved pairs of aligned fraction number line problems and proportionally-equivalent problems expressed in integers, percentages, or fractions (e.g., 3/8 on a 0-1 number line aligned with 3 on a 0-8 number line). Children in the control group solved fraction number-line problems sequentially. At pretest and a two-week delayed posttest, children completed a broad fraction knowledge battery, including estimation, comparison, categorization, ordering, and arithmetic. Results showed that aligning integers and fractions on number lines facilitated better estimation of fractional magnitudes, and the training effect transferred to novel fraction problems after two weeks. Similar gains were not observed for analogies using percentages. These findings highlight the importance of building new mathematical knowledge through analogies to familiar, similar sources.


Assuntos
Transferência de Experiência , Humanos , Masculino , Feminino , Criança , Matemática/educação , Aprendizagem , Formação de Conceito , Conceitos Matemáticos , Resolução de Problemas
2.
Ecotoxicol Environ Saf ; 249: 114462, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38321681

RESUMO

Dechlorane 602 (Dec 602) has biomagnification potential. Our previous studies suggested that exposure to Dec 602 for 7 days induced colonic inflammation even after 7 days of recovery. To shed some light on the underlying mechanisms, disturbances of gut immunity and gene expression were further studied. Adult C57BL/6 mice were administered orally with Dec 602 for 7 days, then allowed to recover for another 7 days. Colonic type 3 innate lymphoid cells (ILC3s) in lamina propria lymphocytes (LPLs) and lymphocytes in mesenteric lymph nodes (MLNs) were examined by flow cytometry. Expressions of genes in the gut were determined by RNA-Seq. It was found that Dec 602 exposure up-regulated the percentage of CD4+ T cells in MLNs. The mean fluorescent intensity (MFI) of interleukin (IL)- 22 in LPLs was decreased, while the MFI of IL-17a as well as the percentage of IL-17a+ ILC3s in LPLs were increased after exposure to Dec 602. Genes involved in the formation of blood vessels and epithelial-mesenchymal transition were up-regulated by Dec 602. Ingenuity pathway analysis of differentially expressed genes predicted that exposure to Dec 602 resulted in the activation of liver X receptor/retinoid X receptor (LXR/RXR) and suppression of muscle contractility. Our results, on one hand, verified that the toxic effects of Dec 602 on gut immunity could last for at least 14 days, and on the other hand, these results predicted other adverse effects of Dec 602, such as muscle dysfunction. Overall, our studies provided insights for the further investigation of Dec 602 and other emerging environmental pollutants.


Assuntos
Hidrocarbonetos Clorados , Interleucina-17 , Linfócitos , Compostos Policíclicos , Animais , Camundongos , Interleucina-17/metabolismo , Imunidade Inata , Camundongos Endogâmicos C57BL , Expressão Gênica
3.
Ecotoxicol Environ Saf ; 239: 113644, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35588618

RESUMO

BACKGROUND AND OBJECTIVES: China has experienced a serious public health burden because of the increased incidence of ischemic stroke. Evidence describing the association between short-term exposure to nitrogen dioxide (NO2) and ischemic stroke morbidity is limited, and few studies have focused on the effects of season and temperature. This study aimed to evaluate the acute effects of NO2 on ischemic stroke incidence in Shenzhen, a southeastern city of China, considering the modified effects of season and temperature. METHODS: A time-stratified case-crossover study was conducted between 2003 and 2014 among 98,482 ischemic stroke hospitalizations. Conditional quasi-Poisson regression was used to estimate the percentage changes in ischemic stroke admissions in relation to each 10 µg/m3 increment in NO2. RESULTS: NO2 was positively associated with ischemic stroke onset over the full year, as well as in the cold season (November through April) and on cold days (ambient temperature≤median temperature), with significant single-day effects within 3 days after the exposure, and significant cumulative effects within the delayed five days. The maximum percentage changes were obtained at lag0-5, with 1.81% (95% confidence interval (CI) was 0.86-2.76%) over the full year, 2.75% (1.48-4.03%) in the cold season, and 3.04% (1.74-4.35%) on cold days. Additionally, the effects of exposure were found to be greater in males and people with higher education, and were lasting longer in subgroups of older individuals. CONCLUSIONS: Our findings provide evidence that reductions in NO2 levels might decrease ischemic stroke morbidity, and enhance the understanding of ischemic stroke occurrence associated with NO2 modified by season and temperature.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , AVC Isquêmico , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/análise , China/epidemiologia , Estudos Cross-Over , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Feminino , Humanos , Incidência , Masculino , Dióxido de Nitrogênio/análise , Dióxido de Nitrogênio/toxicidade , Material Particulado/análise , Estações do Ano , Temperatura
4.
Ecotoxicol Environ Saf ; 231: 113183, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35032729

RESUMO

BACKGROUND: Metal exposures have been reported to be related to the progress of metabolic syndrome (MetS), however, the currents results were still controversial, and the evidence about the effect of multi-metal exposure on MetS were limited. In this study, we intended to evaluate the relationships between metal mixture exposure and the prevalence of MetS in a mid-aged and older population of China. METHODS: The plasma levels of 13 metals (aluminum, magnesium, calcium, iron, manganese, cobalt, copper, arsenic, zinc, selenium, cadmium, molybdenum and thallium) were detected by inductively coupled plasma mass spectrometry (ICP-MS) in 1277 adults recruited from the Eighth Affiliated Hospital of Sun Yat-Sen University (Shenzhen, China). Logistic regression, the adaptive least absolute shrinkage and selectionator operator (LASSO) penalized regression analysis and restricted cubic spline (RCS) analysis were used to explore the associations and dose-response relationships of plasma metals with MetS. To evaluate the cumulative effect of metals, the Bayesian Kernel Machine Regression (BKMR) model was applied. RESULTS: The concentrations of magnesium and molybdenum were lower in the MetS group (p < 0.05). In the single-metal model, the adjusted ORs (95%CI) in the highest quartiles were 0.44 (0.35, 0.76) for magnesium and 0.30 (0.17, 0.51) for molybdenum compared with the lowest quartile. The negative associations and dose-dependent relationships of magnesium and molybdenum with MetS were further validated by the stepwise model, adaptive LASSO penalized regression and RCS analysis. The BKMR models showed that the metal mixture were associated with decreased MetS when the chemical mixtures were≥ 25th percentile compared to their medians, and Mg, Mo were the major contributors to the combined effect. Moreover, concentrations of magnesium were significantly related to blood glucose, and molybdenum was related with BMI, blood glucose and blood pressure. CONCLUSIONS: Elevated levels of plasma magnesium and molybdenum were associated with decreased prevalence of MetS. Further investigations in larger perspective cohorts are needed to confirm our findings.


Assuntos
Síndrome Metabólica , Adulto , Teorema de Bayes , China/epidemiologia , Estudos Transversais , Humanos , Síndrome Metabólica/induzido quimicamente , Síndrome Metabólica/epidemiologia , Metais , Pessoa de Meia-Idade
5.
Int J Biometeorol ; 66(9): 1747-1758, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35750990

RESUMO

The independent associations of extreme temperature and ambient air pollutant with the admission to hospital and mortality of ischemic stroke have been widely investigated. However, knowledge about the modification effects of variation in season and temperature on the association between exposure to nitrogen dioxide (NO2) and ischemic stroke onset is still limited. This study purposed to explore the effect of NO2 on daily ischemic stroke onset modified by season and ambient temperature, and identify the potential population that susceptible to ischemic stroke onset connected with NO2 and ambient temperature. Data on daily ischemic stroke counts, weather conditions, and ambient air pollutant concentrations in Shenzhen were collected between January 1, 2008, and December 31, 2014. The seasonal effect on the NO2-associated onset was measured by a distributed-lag linear model. Furthermore, a generalized additive model that incorporated with stratification analyses was used to calculate the interactive effects between NO2 and ambient temperature. During the winter, the average percentage increase in daily ischemic stroke onset for each 10 µg/m3 increment in NO2 concentration on lagged 2 days was 3.05% (95% CI: 1.31-4.82%), while there was no statistically significant effect of NO2 during summer. And the low-temperature days ([Formula: see text] mean temperature), with a 2.23% increase in incidence (95% CI: 1.18-3.29%) for the same concentration increase in NO2, were significant higher than high temperature days ([Formula: see text] mean temperature). The modification effects of temperature on the study association were more pronounced in individuals aged 65 years or more and in males. The adverse health effects of NO2 on ischemic stroke are more pronounced during winter or low temperature periods. Elderly adults or males presented higher risks with these exposures.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , AVC Isquêmico , Adulto , Idoso , China , Exposição Ambiental , Humanos , Masculino , Dióxido de Nitrogênio , Material Particulado , Estações do Ano , Temperatura
6.
Water Sci Technol ; 80(9): 1683-1691, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32039900

RESUMO

The pollution from nuclear leaks and nuclear disasters (e.g. radioactive iodine) would cause serious harm to human beings and ecosystems for many years. Cocoon silk and deep eutectic solvents (DESs) are both green substances. DESs are easily synthesized, cheap, highly biocompatible and highly biodegradable. Here, we combine the removal of organic dyes and the capture of radioactive iodine by using green DES-pretreated cocoon silk. It is the first time organic dyes have been removed from wastewater by DES-disrupted silk for the purpose of favourably removing iodine. Organic dyes-captured DES-pretreated cocoon silk could be used to capture iodine efficiently. It opens a new route to dispose of one waste from nuclear energy with organic dyes from wastewater captured by green solvents-pretreated natural silk.


Assuntos
Neoplasias da Glândula Tireoide , Águas Residuárias , Ecossistema , Humanos , Radioisótopos do Iodo , Seda , Solventes
7.
Wei Sheng Yan Jiu ; 44(2): 264-9, 2015 Mar.
Artigo em Zh | MEDLINE | ID: mdl-25997231

RESUMO

OBJECTIVE: To conduct a health risk assessment of pesticide residues and its annual trend analysis in drinking water in Shenzhen City. METHODS: The water quality monitoring data of product water, pipe water and secondary supply water during from 2011 to 2013 were collected and analyzed. The risk evaluation models recommended by the U. S. Environmental Protection Agency (USEPA) were employed to perform health risk assessments for children and adults on the 12 non-carcinogenic materials (namely, heptachlor, pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, DDT, malathion, glyphosate, dimethoate, bentazone, atrazine, chlorothalonil, furadan). Results The results of the analysis for water quality from 84 factory samples, 11 peripheral samples and one secondary supply water sample showed that all of the measured indicators in the above mentioned water samples met the National Health Standards (GB 5749-2006) published by Ministry of Health of the People's Republic of China. The adults and children' s health indices (HIs) of the 12 non-carcinogenic materials were greater than 1 (2. 323 - 6. 312). Dimethoate in factory and peripheral water samples posed the largest risks of harm among the non-carcinogenic pollutants measured. And its HIi were also greater than 1 (1. 995 - 5. 094) and followed by hexachlorobenzene and heptachlor. Annual rising trend on health risk of the 12 pesticide residues indicated that their HIT on adults was 2323. 18 x 10(-3) in 2011, 2340. 18 x 10(-3) in 2012 and 2431. 97 x 10(-3) in 2013, and on children 2965. 07 x 10 (-3) in 2011, 2986. 77 x 10(-3) in 2012 and 3103. 93 x 10(-3) in 2013, respectively. This study also suggested that the average risk of peripheral water samples (HIT was equal to 2619. 64 x 10(-3) was greater than that of factory samples (HIT was same as 2366. 92 x 10(-3), and more children' s health risk than adults' risk. CONCLUSION: Health risks of pesticide residues in drinking water in Shenzhen have exceeded the threshold value and dimethoate was the main hazard and more children's health risk than adults' risk. Furthermore, there was an annual rising slowly trend on health risks of pesticide residues in drinking water.


Assuntos
Água Potável/análise , Resíduos de Praguicidas/análise , Poluentes Químicos da Água , Abastecimento de Água/normas , Adulto , Atrazina , Criança , China , Monitoramento Ambiental , Substâncias Perigosas , Humanos , Medição de Risco
8.
Front Med (Lausanne) ; 11: 1340553, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707188

RESUMO

Systemic amyloidosis is a rare protein misfolding and deposition disorder leading to progressive organ failure. Waldenström macroglobulinemia (WM) with systemic amyloidosis as the main manifestation is even rarer. The patient in this study presented with recurrent diarrhea and had not been diagnosed in other hospitals on multiple occasions. Later, his diarrhea worsened and was accompanied by sunken edema of both lower limbs and dizziness. Renal biopsy showed deposits of PAS light-staining material in the glomeruli, interstitium, and small arteries, which stained positively with Congo red. Cardiac ultrasound showed interventricular septum thickening of 17 mm, right ventricular wall myocardial thickening of approximately 0.6 cm, and septal thickening of approximately 0.5 cm, considering myocardial amyloidosis. Electromyography showed abnormal peripheral nerve conduction. Lymphoplasmacytic cells were found in the bone marrow. Taken together, he was diagnosed with WM. He was treated with a BR (Bendamustine + Rituximab) regimen. After 6 courses, the patient's discomfort was relieved, his weight gained 5 kg, the level of serum IgM and dFLC decreased, and cardiac and renal assessments were more relieved. The patient has been followed up for more than 1 month.

9.
PLoS One ; 19(3): e0298529, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38483863

RESUMO

Salidroside (SAL) is a phenol glycoside compound found in plants of the Rhodiola genus which has natural antioxidant and free radical scavenging properties. SAL are able to protect against manganese-induced ototoxicity. However, the molecular mechanism by which SAL reduces levels of reactive oxygen species (ROS) is unclear. Here, we established an in vitro gentamicin (GM) ototoxicity model to observe the protective effect of SAL on GM-induced hair cells (HC) damage. Cochlear explants of postnatal day 4 rats were obtained and randomly divided into six groups: two model groups (treatment with 0.2 mM or 0.4 mM GM for 24 h); two 400 µmol/L SAL-pretreated groups pretreatment with SAL for 3 h followed by GM treatment (0.2 mM or 0.4 mM) for 24 h; 400 µmol/L SAL group (treatment with SAL for 24 h); control group (normal cultured cochlear explants). The protective effects of SAL on GM-induced HC damage, and on mRNA and protein levels of antioxidant enzymes were observed. HC loss occurred after 24 h of GM treatment. Pretreatment with SAL significantly reduced GM-induced OHC loss. In cochlear tissues, mRNA and protein levels of NRF2 and HO-1 were enhanced in the GM alone group compared with the SAL pretreatment GM treatment group. SAL may protect against GM-induced ototoxicity by regulating the antioxidant defense system of cochlear tissues; SAL can activate NRF2/HO-1 signaling, inhibit NF-κB activation, activate AKT, and increase inhibitory phosphorylation of GSK3ß to decrease GSK3 activity, all of which exert antioxidant effects.


Assuntos
Gentamicinas , Glucosídeos , Ototoxicidade , Ratos , Animais , Gentamicinas/toxicidade , Gentamicinas/metabolismo , NF-kappa B/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Células Ciliadas Auditivas , Cóclea/metabolismo , Fenóis/farmacologia , Fenóis/metabolismo , RNA Mensageiro/metabolismo
10.
Front Immunol ; 14: 1127552, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37006313

RESUMO

Giardia duodenalis is a zoonotic intestinal protozoan parasite that may cause host diarrhea and chronic gastroenteritis, resulting in great economic losses annually and representing a significant public health burden across the world. However, thus far, our knowledge on the pathogenesis of Giardia and the related host cell responses is still extensively limited. The aim of this study is to assess the role of endoplasmic reticulum (ER) stress in regulating G0/G1 cell cycle arrest and apoptosis during in vitro infection of intestinal epithelial cells (IECs) with Giardia. The results showed that the mRNA levels of ER chaperone proteins and ER-associated degradation genes were increased and the expression levels of the main unfolded protein response (UPR)-related proteins (GRP78, p-PERK, ATF4, CHOP, p-IRE1, XBP1s and ATF6) were increased upon Giardia exposure. In addition, cell cycle arrest was determined to be induced by UPR signaling pathways (IRE1, PERK and ATF6) through upregulation of p21 and p27 levels and promotion of E2F1-RB complex formation. Upregulation of p21 and p27 expression was shown to be related to Ufd1-Skp2 signaling. Therefore, the cell cycle arrest was induced by ER stress when infected with Giardia. Furthermore, the apoptosis of the host cell was also assessed after exposure to Giardia. The results indicated that apoptosis would be promoted by UPR signaling (PERK and ATF6), but would be suppressed by the hyperphosphorylation of AKT and hypophosphorylation of JNK that were modulated by IRE1 pathway. Taken together, both of the cell cycle arrest and apoptosis of IECs induced by Giardia exposure involved the activation of the UPR signaling. The findings of this study will deepen our understanding of the pathogenesis of Giardia and the associated regulatory network.


Assuntos
Giardia lamblia , Giardia lamblia/genética , Pontos de Checagem da Fase G1 do Ciclo Celular , Estresse do Retículo Endoplasmático/fisiologia , Apoptose , Proteínas Serina-Treonina Quinases/metabolismo
11.
Polymers (Basel) ; 15(11)2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37299237

RESUMO

Density functional theory (DFT) is employed to investigate the promotion of B(C6F5)3 as a ligand for titanium (or vanadium) catalysts in ethylene/1-hexene copolymerization reactions. The results reveal that (I) Ethylene insertion into TiB (with B(C6F5)3 as a ligand ) is preferred over TiH, both thermodynamically and kinetically. (II) In TiH and TiB catalysts, the 2,1 insertion reaction (TiH21 and TiB21) is the primary pathway for 1-hexene insertion. Furthermore, the 1-hexene insertion reaction for TiB21 is favored over TiH21 and is easier to perform. Consequently, the entire ethylene and 1-hexene insertion reaction proceeds smoothly using the TiB catalyst to yield the final product. (III) Analogous to the Ti catalyst case, VB (with B(C6F5)3 as a ligand) is preferred over VH for the entire ethylene/1-hexene copolymerization reaction. Moreover, VB exhibits higher reaction activity than TiB, thus agreeing with experimental results. Additionally, the electron localization function and global reactivity index analysis indicate that titanium (or vanadium) catalysts with B(C6F5)3 as a ligand exhibit higher reactivity. Investigating the promotion of B(C6F5)3 as a ligand for titanium (or vanadium) catalysts in ethylene/1-hexene copolymerization reactions will aid in designing novel catalysts and lead to more cost-effective polymerization production methods.

12.
Biomed Pharmacother ; 165: 115162, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37467648

RESUMO

When activated by unconjugated bilirubin (UCB), inflammatory mediators such as IL - 18 and TNF contribute to the neurotoxicity and ototoxicity observed in severe neonatal hyperbilirubinemia. However, in cell and molecular level, the regulation and mechanism of UCB-induced ototoxicity are remained unclear. In this study, 7-day-old mammary rats were exposed to various concentrations of UCB to imitate the infant auditory damage. The auditory brainstem response result (ABR) indicated severe hearing loss, which occurred with increasing concentration. Morphological analysis of organotypic cochlear cultures treated with different concentrations of UCB indicated that auditory nerve fibers (ANF) were demyelinated and the density of spiral ganglion neurons (SGN) were decreased. In addition, HEI-OC1 cells treated with different concentrations of UCB showed severe necrosis by Flow Cytometry. The morphologic feature of pyroptosis has been observed by scanning electronic microscope. Cleaved Caspase-1, GSDMD and NLRP3 expression were significantly increased in cochlear explants with UCB-induced. To further clarify the molecular mechanism of UCB-induced inner ear cell pyroptosis, specific inhibitors of pyroptosis were applied, the protein associated with pyrotosis such as Cleaved Caspase-1, GSDMD, ASC, IL-18 and NLRP3 were significantly lower than the group with UCB alone. All the data above indicated that ERK /NLRP3/GSDMD signaling pathway involved in UCB-induced ototoxicity.


Assuntos
Hiperbilirrubinemia Neonatal , Ototoxicidade , Animais , Ratos , Bilirrubina/metabolismo , Caspase 1 , Proteína 3 que Contém Domínio de Pirina da Família NLR , Piroptose , Animais Recém-Nascidos , Modelos Animais de Doenças
13.
PLoS One ; 17(10): e0275679, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36288272

RESUMO

High leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) expression caused by an inflammatory condition was reported to promote tumor proliferation and the epithelial-mesenchymal transition (EMT) in various malignant tumors, but those effects have not been studied in hypopharyngeal squamous cell carcinoma (HSCC) and the molecular mechanism remains unclear. This study was aimed to determine whether YAP/TAZ is involved in the regulation of LGR5 expression in the inflammatory condition. Human hypopharyngeal carcinoma FaDu cells were stimulated with inflammatory medium. The cell invasion ability were evaluated through wound healing assay and transwell invasion assay. The expression levels of EMT-related proteins, LGR5, and p-YAP were detected by real time PCR, western blotting, and immunofluorescence. The results showed that LGR5 expression and the EMT process were significantly enhanced under inflammatory condition. The expression of EMT-related proteins was up-regulated, while that of p-YAP was decreased. After inhibiting the high LGR5 expression with short interfering RNA, the expression of EMT-related proteins was also down-regulated, while that of p-YAP was significantly increased. The use of verteporfin (VP), an inhibitor of YAP activity that promotes YAP phosphorylation, did not affect LGR5 expression. In conclusion, we suggest that the inflammatory condition leads to high LGR5 expression, which up-regulating the expression of EMT-related proteins by inhibiting the YAP phosphorylation.


Assuntos
Transição Epitelial-Mesenquimal , Neoplasias de Cabeça e Pescoço , Humanos , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal/genética , Leucina , Processos Neoplásicos , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , RNA Interferente Pequeno , Carcinoma de Células Escamosas de Cabeça e Pescoço , Verteporfina/farmacologia
14.
Dev Psychol ; 58(10): 1912-1930, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35666925

RESUMO

Children display an early sensitivity to implicit proportions (e.g., 1 of 5 apples vs. 3 of 4 apples), but have considerable difficulty in learning the explicit, symbolic proportions denoted by fractions (e.g., "1/5" vs. "3/4"). Theoretically, reducing the gap between representations of implicit versus explicit proportions would improve understanding of fractions, but little is known about how the representations develop and interact with one another. To address this, we asked 177 third, fourth, and fifth graders (M = 9.85 years, 87 girls, 69% White, 19% low income) to estimate the position of proportionally equivalent integers and fractions on number lines (e.g., 3 on a 0-8 number line vs. 3/8 on a 0-1 number line, Study 1). With increasing age, children's estimates of implicit and explicit proportions became more coherent, such that a child's estimates of fractions on a 0-1 number-line was a linear function of the same child's estimates of equivalent integers. To further investigate whether preexisting integer knowledge can facilitate fraction learning through analogy, we assigned 100 third to fifth graders (M = 10.04 years, 55 girls, 76% White) to an Alignment condition, where children estimated fractions and integers on aligned number lines, or to a No Alignment condition (Study 2). Results showed that aligning integers and fractions on number lines facilitated a better understanding of fractional magnitudes, and increased children's fraction estimation accuracy to the level of college students'. Together, findings suggest that analogies can play an important role in building a coherent understanding of proportions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Conhecimento , Aprendizagem , Criança , Feminino , Humanos , Estudantes
15.
Polymers (Basel) ; 14(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36501667

RESUMO

Density functional theory has been used to elucidate the mechanism of Pd copolymerization of cyclopropenone with ethylene. The results reveal that introducing ethylene and cyclopropenone to Pd catalyst is thermodynamically feasible and generates the α,ß-unsaturated ketone unit (UnitA). Cis-mode insertion and Path A1a are the most favorable reaction routes for ethylene and cyclopropenone, respectively. Moreover, cyclopropenone decomposition can generate CO in situ without a catalyst or with a Pd catalyst. The Pd-catalyzed decomposition of cyclopropenone exhibits a lower reaction barrier (22.7 kcal/mol) than its direct decomposition. Our study demonstrates that incorporating CO into the Pd catalyst can generate the isolated ketone unit (UnitB). CO is formed first; thereafter, UnitB is generated. Therefore, the total energy barrier of UnitB generation, accounting for the CO barrier, is 22.7 kcal/mol, which is slightly lower than that of UnitA generation (24.0 kcal/mol). Additionally, the possibility of copolymerizing ethylene, cyclopropenone, and allyl acetate (AAc) has been investigated. The free energy and global reactivity index analyses indicate that the cyclopropenone introduction reaction is more favorable than the AAc insertion, which is consistent with the experimental results. Investigating the copolymerization mechanism will help to develop of a functionalization strategy for polyethylene polymers.

16.
China CDC Wkly ; 4(23): 489-493, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35813264

RESUMO

What is already known about this topic?: Aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via sanitary pipelines in high-rise buildings is possible, however, there is a lack of experimental evidence. What is added by this report?: The field simulation experiment confirmed the existence of a vertical aerosol transmission pathway from toilet flush-soil stack-floor drains without water seal. This report provided experimental evidence for vertical aerosol transmission of clustered outbreaks on 18 floors of a 33-story residential building. What are the implications for public health practice?: The water seal on floor drains is a necessary barrier to prevent the risk of vertical aerosol transmission of infectious disease pathogens in buildings. It is necessary not only to have a U-shaped trap in the drainage pipe, but also to be filled with water regularly.

17.
J Hazard Mater ; 432: 128718, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35338935

RESUMO

The dioxin-like substances polyhalogenated carbazoles (PHCZs) may trigger the aryl hydrocarbon receptor (AhR) signaling pathway. Although the crosstalk between AhR and the hypoxia inducible factor-1 (HIF-1) pathways is generally believed to occur, the exact mechanisms of the HIF-1 pathway in PHCZ toxicity have not been determined. We aimed to elucidate the effect of PHCZs on the HIF-1 pathway and its involvement in the regulation of target genes of HIF-1. Herein, we employed human HepG2 cells transiently transfected with a hypoxia response element (HRE) luciferase reporter to identify PHCZs that could influence HIF-1 pathway. We found that exposure to one of the four selected PHCZs, specifically 1,3,6,8-tetrabromo-9 H-carbazole (1368-BCZ), induced a significant enhancement of the activity of HRE activity. In silico data supported 1368-BCZ-induced HIF-1α activity preferentially. Moreover, 1368-BCZ significantly upregulated the expression of HIF-1 target genes, including endothelial growth factor (VEGF) and erythropoietin. Importantly, the stimulated secretion of VEGF by 1368-BCZ promoted the angiogenesis in human umbilical vein endothelial cells. Therefore, the present experimental and computational studies provide new and direct evidence of 1368-BCZ - HIF-1 interaction, which sheds light on the HIF-mediated cardiovascular toxicity and allows a knowledge-based risk assessment of emerging pollutants.


Assuntos
Neovascularização Patológica , Fator A de Crescimento do Endotélio Vascular , Carbazóis/toxicidade , Células Endoteliais da Veia Umbilical Humana , Humanos , Hipóxia , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
Chemosphere ; 287(Pt 3): 132305, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34563770

RESUMO

BACKGROUND: Metal exposures are suspected to associate with the risk of hyperuricemia (HUA), but the current results are still conflicting. OBJECTIVE: To investigate the associations between multiple plasma metal exposures and HUA risk. METHODS: A cross-sectional study was conducted in 1406 Chinese Han adults who underwent routine physical examination in the Eighth Affiliated Hospital of Sun Yat-Sen University in Shenzhen. The plasma levels of 13 metals were measured by the inductively coupled plasma mass spectrometry (ICP-MS). Multivariable logistic, linear regression models, least absolute shrinkage and selection operator (LASSO) penalized regression analysis, and restricted cubic spline (RCS) models were applied to assess the associations. RESULTS: The median plasma uric acid concentration in HUA group (434 µmol/L) was significantly higher than that in non-HUA group (305 µmol/L). The multivariate-adjusted odds ratios (95% confidence intervals) of HUA were 1.62(1.08-2.43) for magnesium, 1.61(1.05-2.47) for copper, 1.62(1.06-2.49) for zinc, 1.87(1.26-2.81) for arsenic, 1.50(1.01-2.23) for selenium, and 1.70(1.16-2.49) for thallium based on the single-metal logistic regression models, comparing the highest versus the lowest quartile of metal levels. Further multi-metal logistic, linear regression models and the LASSO analysis all indicated positive associations of zinc, arsenic with HUA risk or uric acid levels. RCS model indicated an inverted V-shaped positive association between zinc levels and HUA risk (p for non-linearity = 0.048, p for overall association = 0.022), while arsenic levels showed a positive and linear dose-response relationship with HUA risk (p for non-linearity = 0.892, p for overall association<0.001). CONCLUSIONS: Higher plasma levels of zinc and arsenic might increase HUA risk and showed positive dose-response relationships. Further cohort studies in larger population are required to testify our findings.


Assuntos
Hiperuricemia , Adulto , China/epidemiologia , Estudos Transversais , Humanos , Hiperuricemia/epidemiologia , Metais , Pessoa de Meia-Idade , Ácido Úrico
19.
Environ Int ; 166: 107394, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35820366

RESUMO

BACKGROUND: Chlorinated flame retardant Dechlorane 602 (Dec 602) has been detected in daily food, indicating that it may pose a risk to intestinal health. The intestinal microenvironment plays an important role in intestinal health. Intestinal microbiota and metabolites are two important factors for maintaining the microenvironment. However, little is known about the effects of Dec 602 on intestinal microbiota and metabolites. OBJECTIVES: We aimed to probe the effects of Dec 602 on the intestine by revealing the changes that Dec 602 caused to the intestinal microbiota and metabolites. METHODS: Adult female C57BL/6 mice were exposed to Dec 602 (low/high doses: 1.0/10.0 µg/kg body weight per day) orally for 7 consecutive days, and sacrificed after 7 days of recovery. The composition of colonic microbiota was measured by 16S rRNA gene sequencing, and the colonic metabolites were determined by LC-ESI-MS/MS. Finally, the effects of Dec 602 on the colon were validated by histopathological analysis. RESULTS: The intestinal microbiota composition was altered toward a pro-inflammatory status after exposure to Dec 602. Dec 602 exposure also up-regulated oxidative metabolites (glutathione disulfide, taurine and retinoic acid) and pro-inflammatory metabolites (prostaglandin E2). On the other hand, antioxidative metabolites (s-adenosylmethionine and 11-cis-retinol) and anti-inflammatory metabolites (alpha-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid) were down-regulated after exposure to Dec 602. Infiltration of lymphocytes in the colonic lamina propria was observed in the mice treated with Dec 602 for 7 days, and it was not recovered after another 7 days without further treatment. CONCLUSION: Dec 602 interfered with the colonic microbiota and metabolome, and exhibited inflammatory features. Histopathological studies confirmed that Dec 602 exposure did induce colonic inflammation.

20.
Environ Pollut ; 313: 120141, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36087894

RESUMO

The homeostasis of gut immunity and microbiota are associated with the health of the gut. Dechlorane 602 (Dec 602) with food web magnification potential has been detected in daily food. People who were orally exposed to Dec 602 may encounter increased risk of health problems in the gut. In order to reveal the influence of short-term exposure of Dec 602 on gut immunity and microbiota, adult female C57BL/6 mice were administered orally with Dec 602 (low/high doses: 1.0/10.0 µg/kg body weight per day) for 7 days. Lymphocytes were examined by flow cytometry. Gut microbiota was measured by 16S rRNA gene sequencing. Results showed that fecal IgA was upregulated after exposure to the high dose of Dec 602, suggesting that there might be inflammation in the gut. Then, changes of immune cells in mesenteric lymph nodes and colonic lamina propria were examined. We found that exposure to the high dose of Dec 602 decreased the percentages of the anti-inflammatory T regulatory cells in mesenteric lymph nodes. In colonic lamina propria, the production of gut protective cytokine interleukin-22 by CD4+ T cells was decreased, and a decreased trend of interleukin-22 production was also observed in type 3 innate lymphoid cells in the high dose group. Furthermore, an altered microbiota composition toward inflammation in the gut was observed after exposure to Dec 602. Additionally, the altered microbiota correlated with changes of immune parameters, suggesting that there were interactions between influenced microbiota and immune parameters after exposure to Dec 602. Taken together, short-term exposure to Dec 602 induced gut immunity and microbiota perturbations, and this might be the mechanisms for Dec 602 to elicit inflammation in the gut.


Assuntos
Microbioma Gastrointestinal , Imunidade Inata , Animais , Citocinas , Feminino , Microbioma Gastrointestinal/genética , Hidrocarbonetos Clorados , Imunoglobulina A , Inflamação , Linfócitos , Camundongos , Camundongos Endogâmicos C57BL , Compostos Policíclicos , RNA Ribossômico 16S/genética
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