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1.
Angew Chem Int Ed Engl ; 63(9): e202314092, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38193569

RESUMO

The phase distribution and organic spacer cations play pivotal roles in determining the emission performance and stability of perovskite quantum wells (QWs). Here, we propose a universal molecular regulation strategy to tailor phase distribution and enhance the stability of CsPbBr3 QWs. The capability of sterically hindered ligands with formidable surface binding groups is underscored in directing CsPbBr3 growth and refining phase distribution. With trimethylamine modified boron dipyrromethene (BDP-TMA) ligand as a representative, the BDP-TMA driven can precisely control phase distribution and passivate defects of CsPbBr3 . Notably, BDP-TMA acts as a co-spacer organic entity in obtained BDP-TMA-CsPbBr3 , facilitating efficient singlet energy transfer and tailoring the luminescence to produce a distinctive bluish-white emission. The BDP-TMA-CsPbBr3 demonstrates significant phase stability under water exposure, light irradiation, and moderate temperature. Interestingly, BDP-TMA-CsPbBr3 exhibits the thermally-induced dynamic fluorescence control at elevated temperatures, which can be achieved feasible for advanced information encryption. This discovery paves the way for the exploration of perovskite QWs in applications like temperature sensing, anti-counterfeiting, and other advanced optical smart technologies.

2.
Environ Sci Technol ; 57(49): 20854-20863, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38010983

RESUMO

The limited information in existing mass spectral libraries hinders an accurate understanding of the composition, behavior, and toxicity of organic pollutants. In this study, a total of 350 polycyclic aromatic compounds (PACs) in 9 categories were successfully identified in fine particulate matter by gas chromatography high resolution mass spectrometry. Using mass spectra and retention indexes predicted by in silico tools as complementary information, the scope of chemical identification was efficiently expanded by 27%. In addition, quantitative structure-activity relationship models provided toxicity data for over 70% of PACs, facilitating a comprehensive health risk assessment. On the basis of extensive identification, the cumulative noncarcinogenic risk of PACs warranted attention. Meanwhile, the carcinogenic risk of 53 individual analogues was noteworthy. These findings suggest that there is a pressing need for an updated list of priority PACs for routine monitoring and toxicological research since legacy polycyclic aromatic hydrocarbons (PAHs) contributed modestly to the overall abundance (18%) and carcinogenic risk (8%). A toxicological priority index approach was applied for relative chemical ranking considering the environmental occurrence, fate, toxicity, and analytical availability. A list of 39 priority analogues was compiled, which predominantly consisted of high-molecular-weight PAHs and alkyl derivatives. These priority PACs further enhanced source interpretation, and the highest carcinogenic risk was attributed to coal combustion.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Compostos Policíclicos , Compostos Policíclicos/análise , Poluentes Atmosféricos/análise , Fluxo de Trabalho , Monitoramento Ambiental/métodos , Material Particulado/análise , Medição de Risco , China
3.
Neuroimage ; 259: 119394, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35718022

RESUMO

Although words and faces activate neighboring regions in the fusiform gyrus, we lack an understanding of how such category selectivity emerges during development. To investigate the organization of reading and face circuits at the earliest stage of reading acquisition, we measured the fMRI responses to words, faces, houses, and checkerboards in three groups of 60 French children: 6-year-old pre-readers, 6-year-old beginning readers and 9-year-old advanced readers. The results showed that specific responses to written words were absent prior to reading, but emerged in beginning readers, irrespective of age. Likewise, specific responses to faces were barely visible in pre-readers and continued to evolve in the 9-year-olds, yet primarily driven by age rather than by schooling. Crucially, the sectors of ventral visual cortex that become specialized for words and faces harbored their own functional connectivity prior to reading acquisition: the VWFA with left-hemispheric spoken language areas, and the FFA with the contralateral region and the amygdalae. The results support the view that reading acquisition occurs through the recycling of a pre-existing but plastic circuit which, in pre-readers, already connects the VWFA site to other distant language areas. We argue that reading acquisition does not compete with the face system directly, through a pruning of preexisting face responses, but indirectly, by hindering the slow growth of face responses in the left hemisphere, thus increasing a pre-existing right hemispheric bias.


Assuntos
Leitura , Córtex Visual , Mapeamento Encefálico , Criança , Humanos , Idioma , Imageamento por Ressonância Magnética , Reconhecimento Visual de Modelos/fisiologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia , Córtex Visual/fisiologia
4.
Inorg Chem ; 61(44): 17590-17598, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36272156

RESUMO

Zero-dimensional Cs4PbBr6 nanocrystals (NCs) possess attractive photoluminescence (PL) properties and feature facile chemical synthesis, making them promising for application in luminescent materials. However, Cs4PbBr6 remains sensitive to polar solvents and thermal stimuli because of soft ionic nature of Cs4PbBr6 and dynamic behavior of surface ligands. Herein, a strategy controlled by an in situ surface coordination reaction is developed to fabricate stable NCs with a Cs4PbBr6-Zn(moi)2 core-shell structure. It was found that the Cs4PbBr6 surface regulated by the use of 2-mercaptoimidazole (called moi) and the coordination between the -NH group of moi and Zn2+ is critical for the formation of Cs4PbBr6-Zn(moi)2 core-shell NCs. Meanwhile, the thickness of the Zn(moi)2 shell can be facilely controlled by the growth time because of the solubility of moi and Zn(OAc)2·2H2O in ethyl acetate. Compared to bare Cs4PbBr6, Cs4PbBr6-Zn(moi)2 NCs exhibited highly improved polar solvent resistance and thermal stability. By combining the sensitivity of Cs4PbBr6 and the stability of Cs4PbBr6-Zn(moi)2, we used two NCs as PL security inks to fabricate optical anticounterfeiting labels. Thus, the disposable or reusable optical anticounterfeiting label is achieved by changing the external dual-stimuli. This work provides a novel strategy to enhance the stability of Cs4PbBr6 and develop its potential interest for application in anticounterfeiting technologies.


Assuntos
Nanopartículas , Nanopartículas/química , Luminescência , Solubilidade , Zinco/química
5.
Environ Sci Technol ; 56(15): 10681-10690, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35839457

RESUMO

Stress from mixtures of synthetic chemicals is among the key issues that have significant adverse impacts on the marine ecosystems. A robust screening workflow integrating toxicological-based ranking schemes is still deficient for comprehensive investigation on the main constituents in chemical mixtures that contribute to the ecological risks. In this study, the presence and compositions of a collection of priority pollutants were monitored by suspect screening analysis of seawater and estuarine water samples from the semiclosed Bohai Sea. In total, 108 organic pollutants in nine use categories were identified. Pesticides, intermediates, plastic additives, and per- and polyfluoroalkyl substances were the extensively detected chemical groups. Varied distribution patterns of the pollutants were illustrated intuitively in distinctive sampling areas by hierarchical cluster analysis, which were mainly influenced by run-off inputs, ocean currents, and chemical use history. Ecological risks of chemicals with quantified residue levels were first assessed by the toxicity-weighted concentration ranking scheme, and pentachlorophenol was found as the main contributor in the investigating areas. By optimization of multiple alternative variables (e.g., instrumental response and detection frequency), extended ranking of all the identified pollutants was plausible under the toxicological priority index framework. Similarity in toxicological endpoints of the prioritized pollutants could further been screened by ToxAlerts. Aromatic amine was highlighted as the most frequently detected structural alert (SA) for genotoxic carcinogenicity and mutagenicity. These findings fully demonstrate rationality of the ranking schemes integrated into the suspect screening analysis for profiling contamination characteristics, assessing ecological risk potentials, and prioritizing SAs.


Assuntos
Poluentes Ambientais , Praguicidas , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Praguicidas/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
6.
Am J Orthod Dentofacial Orthop ; 162(2): e63-e70, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35660339

RESUMO

INTRODUCTION: This study aimed to compare the designed and achieved mesiodistal angulation of maxillary canines and posterior teeth (MCPT) for first premolar extraction with clear aligner treatment and identify the main influencing factors for preventing MCPT tipping toward the extraction space. METHODS: A total of 21 adults with first premolar extraction were recruited. The designed and achieved tooth movement of MCPT was measured by superimposing their respective pretreatment and posttreatment cone-beam computed tomography images and compared with the designed tooth movement in ClinCheck using the paired t test and scatter plot analysis. Influencing factors, including dental arch length change, canine distalization, and initial mesiodistal angulation, were analyzed using the linear mixed-effect model. RESULTS: Designed distal crown tipping (second premolar, 10.73 ± 3.22°; first molar, 9.83 ± 3.60°; second molar, 7.18 ± 2.36°) significantly increased the distal inclination of the second premolar (2.50° ± 5.15°; P ï¼œ0.001), first molar (1.07° ± 4.14°; P ï¼œ0.001), and second (0.70° ± 3.78°; P ï¼œ0.001). Furthermore, mesial tipping (8.59° ± 6.03°; P ï¼œ0.001) achieved appropriate distal crown tipping of canines (-6.43° ± 5.04°; P ï¼œ0.001). The implemented preliminary formulas showed that shortening of the dental arch length, the distance of canine distalization, and initial mesiodistal angulation were closely related to the antitipping design. CONCLUSIONS: Designed distal crown tipping of posterior teeth and mesial crown tipping of canines might prevent unwanted crown tipping toward the extraction space during space closure. The proposed preliminary formula could guide antitipping designs in clear aligner treatment.


Assuntos
Maxila , Aparelhos Ortodônticos Removíveis , Dente Pré-Molar/diagnóstico por imagem , Dente Pré-Molar/cirurgia , Maxila/diagnóstico por imagem , Dente Molar , Técnicas de Movimentação Dentária
7.
Stem Cells ; 38(3): 395-409, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31721356

RESUMO

Mesenchymal stem cells (MSCs), which are undifferentiated stem cells with the property of stemness and the potential to differentiate into multiple lineages, including osteoblasts, have attracted a great deal of attention in bone tissue engineering. Consistent with the heterogeneity of MSCs, various surface markers have been used. However, it is still unclear which markers of MSCs are best for cell amplification in vitro and later bone regeneration in vivo. Krüppel-like Factor 2 (KLF2) is an important indicator of the stemness of human MSCs (hMSCs) and as early vascularization is also critical for bone regeneration, we used KLF2 as a novel in vitro marker for MSCs and investigated the angiogenesis and osteogenesis between KLF2+ MSCs and endothelial cells (ECs). We found a synergistic interaction between hMSCs and human umbilical vein ECs (HUVECs) in that KLF2+ stemness-maintained hMSCs initially promoted the angiogenesis of HUVECs, which in turn more efficiently stimulated the osteogenesis of hMSCs. In fact, KLF2+ hMSCs secreted angiogenic factors initially, with some of the cells then differentiating into pericytes through the PDGF-BB/PDGFR-ß signaling pathway, which improved blood vessel formation. The matured HUVECs in turn synergistically enhanced the osteogenesis of KLF2+ hMSCs through upregulated vascular endothelial growth factor. A three-dimensional coculture model using cell-laden gelatin methacrylate (GelMA) hydrogel further confirmed these results. This study provides insight into the stemness-directed synergistic interaction between hMSCs and HUVECs, and our results will have a profound impact on further strategies involving the application of KLF2+ hMSC/HUVEC-laden GelMA hydrogel in vascular network bioengineering and bone regeneration.


Assuntos
Regeneração Óssea/fisiologia , Fatores de Transcrição Kruppel-Like/metabolismo , Células-Tronco Mesenquimais/metabolismo , Humanos
8.
Environ Sci Technol ; 55(14): 9508-9517, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-33764750

RESUMO

Chemical mixtures in surface waters could have significant impacts on exposure risks to human beings and pollution stress to aquatic system. By suspect screening analysis of high-resolution mass spectrometry data, occurrence, and compositions of ToxCast chemicals were investigated in grab estuarine water samples from a combination of 20 rivers that represents approximately 70% of the total river flow discharge along the east coast of China. In total, 59 ToxCast chemicals in seven use categories were identified, in which pesticides, intermediates, and pharmaceuticals were the abundant analogues. Significant differences in pollutant composition profiles were noticed, which possibly reflected singular release pattern and geographical-relevant usage preference (especially for herbicides and fungicides in the pesticide category). With the aid of tentative quantitative/semiquantitative measurement, essential contributors to the cumulative pollutant mass discharges and aquatic acute toxicity potentials were focused onto few particular chemicals. Existence of transformation products was further explored, which indicated that the fates of the selected parent ToxCast chemicals could be influenced by dominating transformation reactions (e.g., N-dealkylation and hydroxylation) and possible environmental factors (i.e., microbial activity). The results emphasize the necessity of suspect screening analysis for assessing the influence of terrestrial emissions of pollutants to the surrounding environment.


Assuntos
Herbicidas , Praguicidas , Poluentes Químicos da Água , China , Monitoramento Ambiental , Humanos , Praguicidas/análise , Rios , Poluentes Químicos da Água/análise
9.
J Am Chem Soc ; 141(15): 6345-6351, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30875223

RESUMO

Efficient control of crystallization and defects of perovskite films are the key factors toward the performance and stability of perovskite solar cells (PSCs), especially for the preparation of large-area PSCs devices. Herein, we directly embedded surfactant-like monoammonium zinc porphyrin (ZnP) compound into the methylammonium (MA+) lead iodide perovskite film to blade-coat large-area uniform perovskite films as large as 16 cm2. Efficiency as high as 18.3% for blade-coating large-area (1.96 cm2) PSCs with ZnP was unprecedentedly achieved, while the best efficiency of fabricated small-area (0.1 cm2) device was up to 20.5%. The detailed analyses demonstrated the functions of ZnP in crystallization control and defects passivation of perovskite surfaces and grain boundaries. As a consequence, the ZnP-encapsulated devices retained over 90% of its initial efficiency after 1000 h with a humidity of about 45% at 85 °C. This research presents a facile way to achieve the synergistic effect of large-area coating, morphology tailoring, and defect suppression based on the molecular encapsulation strategy for perovskite films, further improving the photovoltaic performance and stability of PSCs.

10.
Neuroimage ; 179: 288-297, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29902587

RESUMO

Several neuroimaging studies have explored the neural basis of literacy difficulties in the second language (L2). However, it remains unclear whether the associated neural alterations are related to literacy abilities in the first language (L1). Using magnetic resonance imaging, we explore this issue with two experiments in Mandarin-speaking children learning English as second language. In the first experiment, we investigated children with literacy difficulties in L2 and L1 (poor in both, PB) and children with literacy difficulties only in L2 (poor in English, PE). We compared the brain structure in these two groups to a control literacy (CL) group. The results showed that the CL group had significantly less gray matter volume in the left supramarginal gyrus compared to the PB group and moderately less gray matter volume compared to the PE group. In addition, the PB group had significant greater gray matter volume in the left medial fusiform gyrus compared to the PE group and had marginally greater gray matter volume compared to the CL group. In the second experiment, we explored the relationship between the two atypical regions and literacy abilities in the two languages in an independent sample consisting of children with typical literacy. Correlation analyses revealed that the left supramarginal gyrus was significantly associated with literacy performance only in the second language, English, whereas the left medial fusiform gyrus did not correlate with the performances in either L1 or L2. Taken together, these findings suggest that literacy difficulties in an alphabetic L2 are associated with a structural abnormality in the left supramarginal gyrus, a region implicated in phonological processing, which is independent of literacy abilities in the native language.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Idioma , Aprendizagem/fisiologia , Criança , Feminino , Humanos , Alfabetização , Imageamento por Ressonância Magnética , Masculino , Multilinguismo
11.
J Am Chem Soc ; 140(37): 11577-11580, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30125479

RESUMO

Defects within the grain boundaries (GBs) of halide perovskite films make fabrication of efficient and stable perovskite solar cells (PSCs) highly challenging. Here, a low-cost tetra-ammonium zinc phthalocyanine (ZnPc) was used to post-treat the MAPbI3 (MA = CH3NH3) film. Two-dimensional (ZnPc)0.5MA n-1Pb nI3 n+1 was successfully constructed within the GBs of MAPbI3 film achieving a GBs suture for passivating the defects in GBs. Time-resolved photoluminescence showed that the modification increased the decay time from 44 to 57 ns indicating the passivation of GBs reduces trap-assisted recombination. The PSCs with modified perovskite exhibited increased photovoltage, and the best efficiency was improved up to 20.3%. More importantly, the long-term stability of the responding PSCs against humidity and heating was further improved unprecedentedly. Moreover, the modified MAPbI3 films revealed a self-repairing capability under mild heating. This work provided a novel insight into ongoing fabrication of efficient and stable PSCs by the efficient GBs suture with low-cost phthalocyanine.

12.
Cancer Sci ; 109(3): 688-698, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29284199

RESUMO

Bone marrow mesenchymal stem cells (BMMSC) have been shown to be recruited to the tumor microenvironment and exert a tumor-promoting effect in a variety of cancers. However, the molecular mechanisms related to the tumor-promoting effect of BMMSC on head and neck cancer (HNC) are not clear. In this study, we investigated Periostin (POSTN) and its roles in the tumor-promoting effect of BMMSC on HNC. In vitro analysis of HNC cells cultured in BMMSC-conditioned media (MSC-CM) showed that MSC-CM significantly promoted cancer progression by enhancing cell proliferation, migration, epithelial-mesenchymal transformation (EMT), and altering expression of cell cycle regulatory proteins and inhibition of apoptosis. Moreover, MSC-CM promoted the expression of POSTN and POSTN promoted HNC progression through the activation of the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway. In a murine model of HNC, we found that BMMSC promoted tumor growth, invasion, metastasis and enhanced the expression of POSTN and EMT in tumor tissues. Clinical sample analysis further confirmed that the expression of POSTN and N-cadherin were correlated with pathological grade and lymph node metastasis of HNC. In conclusion, this study indicated that BMMSC promoted proliferation, invasion, survival, tumorigenicity and migration of head and neck cancer through POSTN-mediated PI3K/Akt/mTOR activation.


Assuntos
Neoplasias de Cabeça e Pescoço/metabolismo , Células-Tronco Mesenquimais/citologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Moléculas de Adesão Celular , Linhagem Celular Tumoral , Proliferação de Células , Meios de Cultivo Condicionados/farmacologia , Progressão da Doença , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Humanos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Metástase Neoplásica , Estadiamento de Neoplasias , Transplante de Neoplasias , Transdução de Sinais , Regulação para Cima
13.
Hum Brain Mapp ; 38(8): 4109-4124, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28513102

RESUMO

Bilingual experience can delay cognitive decline during aging. A general hypothesis is that the executive control system of bilinguals faces an increased load due to controlling two languages, and this increased load results in a more "tuned brain" that eventually creates a neural reserve. Here we explored whether such a neuroprotective effect is independent of language modality, i.e., not limited to bilinguals who speak two languages but also occurs for bilinguals who use a spoken and a signed language. We addressed this issue by comparing bimodal bilinguals to monolinguals in order to detect age-induced structural brain changes and to determine whether we can detect the same beneficial effects on brain structure, in terms of preservation of gray matter volume (GMV), for bimodal bilinguals as has been reported for unimodal bilinguals. Our GMV analyses revealed a significant interaction effect of age × group in the bilateral anterior temporal lobes, left hippocampus/amygdala, and left insula where bimodal bilinguals showed slight GMV increases while monolinguals showed significant age-induced GMV decreases. We further found through cortical surface-based measurements that this effect was present for surface area and not for cortical thickness. Moreover, to further explore the hypothesis that overall bilingualism provides neuroprotection, we carried out a direct comparison of GMV, extracted from the brain regions reported above, between bimodal bilinguals, unimodal bilinguals, and monolinguals. Bilinguals, regardless of language modality, exhibited higher GMV compared to monolinguals. This finding highlights the general beneficial effects provided by experience handling two language systems, whether signed or spoken. Hum Brain Mapp 38:4109-4124, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Envelhecimento/patologia , Envelhecimento/psicologia , Encéfalo/diagnóstico por imagem , Multilinguismo , Neuroproteção/fisiologia , Adulto , Idoso , Encéfalo/patologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Processamento de Imagem Assistida por Computador , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Língua de Sinais
14.
Cerebellum ; 16(2): 496-507, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27785760

RESUMO

Previous neuroimaging studies have found atypical cerebellar activation in individuals with dyslexia in either motor-related tasks or language tasks. However, studies investigating atypical cerebellar activation in individuals with dyslexia have mostly used tasks tapping phonological processing. A question that is yet unanswered is whether the cerebellum in individuals with dyslexia functions properly during orthographic processing of words, as growing evidence shows that the cerebellum is also involved in visual and spatial processing. Here, we investigated cerebellar activation and cerebro-cerebellar functional connectivity during word processing in dyslexic readers and typically developing readers using tasks that tap orthographic and phonological codes. In children with dyslexia, we observed an abnormally higher engagement of the bilateral cerebellum for the orthographic task, which was negatively correlated with literacy measures. The greater the reading impairment was for young dyslexic readers, the stronger the cerebellar activation was. This suggests a compensatory role of the cerebellum in reading for children with dyslexia. In addition, a tendency for higher cerebellar activation in dyslexic readers was found in the phonological task. Moreover, the functional connectivity was stronger for dyslexic readers relative to typically developing readers between the lobule VI of the right cerebellum and the left fusiform gyrus during the orthographic task and between the lobule VI of the left cerebellum and the left supramarginal gyrus during the phonological task. This pattern of results suggests that the cerebellum compensates for reading impairment through the connections with specific brain regions responsible for the ongoing reading task. These findings enhance our understanding of the cerebellum's involvement in reading and reading impairment.


Assuntos
Cerebelo/fisiopatologia , Cérebro/fisiopatologia , Dislexia/fisiopatologia , Reconhecimento Visual de Modelos/fisiologia , Fonética , Leitura , Mapeamento Encefálico , Cerebelo/diagnóstico por imagem , Cérebro/diagnóstico por imagem , Criança , Dislexia/diagnóstico por imagem , Feminino , Humanos , Testes de Linguagem , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Testes Neuropsicológicos , Estimulação Luminosa
15.
Neuroimage ; 129: 25-39, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26673115

RESUMO

The present study tested the hypothesis that language distance between first language (L1) and second language (L2) influences the assimilation and accommodation pattern in Korean-Chinese-English trilinguals. The distance between English and Korean is smaller than that between Chinese and Korean in terms of orthographic transparency, because both English and Korean are alphabetic, whereas Chinese is logographic. During fMRI, Korean trilingual participants performed a visual rhyming judgment task in three languages (Korean: KK, Chinese: KC, English: KE). Two L1 control groups were native Chinese and English speakers performing the task in their native languages (CC and EE, respectively). The general pattern of brain activation of KC was more similar to that of CC than KK, suggesting accommodation. Higher accuracy in KC was associated with decreased activation in regions of the KK network, suggesting reduced assimilation. In contrast, the brain activation of KE was more similar to that of KK than EE, suggesting assimilation. Higher accuracy in KE was associated with decreased activation in regions of the EE network, suggesting reduced accommodation. Finally, an ROI analysis on the left middle frontal gyrus revealed greater activation for KC than for KE, suggesting its selective involvement in the L2 with more arbitrary mapping between orthography and phonology (i.e., Chinese). Taken together, the brain network involved in L2 reading is similar to the L1 network when L2 and L1 are similar in orthographic transparency, while significant accommodation is expected when L2 is more opaque than L1.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiologia , Multilinguismo , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
16.
Sensors (Basel) ; 16(9)2016 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-27657082

RESUMO

A novel, intensity-stabilized, fast-scanned, direct absorption spectroscopy (IS-FS-DAS) instrumentation, based on a distributed feedback (DFB) diode laser, is developed. A fiber-coupled polarization rotator and a fiber-coupled polarizer are used to stabilize the intensity of the laser, which significantly reduces its relative intensity noise (RIN). The influence of white noise is reduced by fast scanning over the spectral feature (at 1 kHz), followed by averaging. By combining these two noise-reducing techniques, it is demonstrated that direct absorption spectroscopy (DAS) can be swiftly performed down to a limit of detection (LOD) (1σ) of 4 × 10-6, which opens up a number of new applications.

17.
Early Educ Dev ; 26(8): 1210-1233, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26430351

RESUMO

Research Findings: The purpose of this study was to examine differences in the development of conflict management strategies, focusing on 3- and 5-year-olds, through a comparison of 3 neighboring Asian cultures, those of China (n = 114), Japan (n = 98), and Korea (n = 90). The dual concern model of conflict management was adopted to probe which strategy children would prefer to use in 2 hypothetical conflict situations. Results indicated that, first, for disagreement, 3-year-olds in the 3 countries equally preferred the dominating strategy. For competition for resources, 3-year-olds differed in their strategy preference across all cultures. Second, the observed strategy preference of 3- to 5-year-old children in this study was more or less different from that of older schoolchildren, regardless of culture. Practice or Policy: These findings suggest the significance of the context, the complexity of the phenomenon of the development of cultural differences, and the significance of cohort sampling.

18.
Dig Dis Sci ; 59(2): 346-57, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24132507

RESUMO

BACKGROUND: Elevated serum saturated fatty acid levels and hepatocyte lipoapoptosis are features of nonalcoholic fatty liver disease (NAFLD). AIM: The purpose of this study was to investigate saturated fatty acid induction of lipoapoptosis in human liver cells and the underlying mechanisms. METHODS: Human liver L02 and HepG2 cells were treated with sodium palmitate, a saturated fatty acid, for up to 48 h with or without lithium chloride, a glycogen synthase kinase-3ß (GSK-3ß) inhibitor, or GSK-3ß shRNA transfection. Transmission electron microscopy was used to detect morphological changes, flow cytometry was used to detect apoptosis, a colorimetric assay was used to detect caspase-3 activity, and western blot analysis was used to detect protein expression. RESULTS: The data showed that sodium palmitate was able to induce lipoapoptosis in L02 and HepG2 cells. Western blot analysis showed that sodium palmitate activated GSK-3ß protein, which was indicated by dephosphorylation of GSK-3ß at Ser-9. However, inhibition of GSK-3ß activity with lithium chloride treatment or knockdown of GSK-3ß expression with shRNA suppressed sodium palmitate-induced lipoapoptosis in L02 and HepG2 cells. On a molecular level, inhibition of GSK-3ß expression or activity suppressed sodium palmitate-induced c-Jun-N-terminal kinase (JNK) phosphorylation and Bax upregulation, whereas GSK-3ß inhibition did not affect endoplasmic reticulum stress-induced activation of unfolded protein response. CONCLUSIONS: The present data demonstrated that saturated fatty acid sodium palmitate-induced lipoapoptosis in human liver L02 and HepG2 cells was regulated by GSK-3ß activation, which led to JNK activation and Bax upregulation. This finding indicates that GSK-3ß inhibition may be a potential therapeutic target to control NAFLD.


Assuntos
Apoptose/efeitos dos fármacos , Fígado Gorduroso/induzido quimicamente , Quinase 3 da Glicogênio Sintase/metabolismo , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Ácido Palmítico/toxicidade , Caspase 3/metabolismo , Forma Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Fígado Gorduroso/enzimologia , Fígado Gorduroso/patologia , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta , Células Hep G2 , Hepatócitos/enzimologia , Hepatócitos/ultraestrutura , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Fígado/enzimologia , Fígado/ultraestrutura , Hepatopatia Gordurosa não Alcoólica , Fosforilação , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Transfecção , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismo
19.
J Colloid Interface Sci ; 660: 449-457, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38244510

RESUMO

In mixed Sn-Pb perovskites, the synergistic properties of tin (Sn) and lead (Pb) are leveraged, effectively combining the merits of Pb-based perovskites while simultaneously reducing Pb-associated toxicity. However, the propensity for Sn to undergo facile oxidation from Sn2+ to Sn4+ poses a significant challenge to the stability of these mixed perovskites, limiting their advancement. This study proposes an innovative acetic acid (HAc)-driven synthesis approach to obtain a stable chain-like MAPb0.5Sn0.5Br3 nano-assembly. Leveraging the acidic properties of HAc serves a dual purpose. Primarily, it curtails the oxidation of Sn2+ to Sn4+. Secondly, it orchestrates nanocrystals (NCs) into a more uniform and ordered chain-like assembly, a consequence of hydrogen bonding and coordination interactions facilitated by the HAc. Additionally, HAc demonstrates its capability to passivate MAPb0.5Sn0.5Br3 surface through coordination bonding with unsaturated sites (i.e., Sn2+ or Pb2+), thus effectively compensating for bromide vacancies. Introducing HAc during the synthesis process yields perovskite NCs with enhanced thermal resilience, optical and water stability. Drawing upon the different stimulus responses of synthesized perovskite NCs when exposed to external environment, the optical anti-counterfeiting labels are prepared. The findings provide a potent strategy for augmenting the stability of perovskite NCs, suggesting their potential applicability in anti-counterfeiting endeavors.

20.
Dalton Trans ; 53(2): 582-590, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38059743

RESUMO

Photodynamic therapy provides a promising solution for treating various cancer types. In this study, three distinct asymmetric porphyrin-cisplatin complex photosensitizers (ZnPt-P1, ZnPt-P2, and ZnPt-P3) were synthesized, each having unique side chains. Through a set of experiments involving singlet oxygen detection and density functional theory, ZnPt-P1 was demonstrated to have excellent efficacy, exceeding that of ZnPt-P2 and ZnPt-P3. Notably, ZnPt-1 showed significant phototoxicity while maintaining low dark toxicity when tested on HepG2 cells. Additionally, further examination revealed that ZnPt-P1 had the capability to generate reactive oxygen species within cancer cells when exposed to light irradiation. Taken together, these results highlight the potential of ZnPt-P1 as a photosensitizer for use in photodynamic therapy. This study contributes to enhancing cancer treatment methodologies and provides insights for the future development of innovative drugs for photosensitization.


Assuntos
Fotoquimioterapia , Porfirinas , Fármacos Fotossensibilizantes , Cisplatino/farmacologia , Porfirinas/química , Oxigênio Singlete/química
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