Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 309
Filtrar
1.
Psychophysiology ; : e14531, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38297978

RESUMO

Filtering plays an essential role in event-related potential (ERP) research, but filter settings are usually chosen on the basis of historical precedent, lab lore, or informal analyses. This reflects, in part, the lack of a well-reasoned, easily implemented method for identifying the optimal filter settings for a given type of ERP data. To fill this gap, we developed an approach that involves finding the filter settings that maximize the signal-to-noise ratio for a specific amplitude score (or minimizes the noise for a latency score) while minimizing waveform distortion. The signal is estimated by obtaining the amplitude score from the grand average ERP waveform (usually a difference waveform). The noise is estimated using the standardized measurement error of the single-subject scores. Waveform distortion is estimated by passing noise-free simulated data through the filters. This approach allows researchers to determine the most appropriate filter settings for their specific scoring methods, experimental designs, subject populations, recording setups, and scientific questions. We have provided a set of tools in ERPLAB Toolbox to make it easy for researchers to implement this approach with their own data.

2.
J Am Chem Soc ; 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38367215

RESUMO

An enclosed nanospace often shows a significant confinement effect on chemistry within its inner cavity, while whether an open space can have this effect remains elusive. Here, we show that the open surface of TiO2 creates a confined environment for In2O3 which drives spontaneous transformation of free In2O3 nanoparticles in physical contact with TiO2 nanoparticles into In oxide (InOx) nanolayers covering onto the TiO2 surface during CO2 hydrogenation to CO. The formed InOx nanolayers are easy to create surface oxygen vacancies but are against over-reduction to metallic In in the H2-rich atmospheres, which thus show significantly enhanced activity and stability in comparison with the pure In2O3 catalyst. The formation of interfacial In-O-Ti bonding is identified to drive the In2O3 dispersion and stabilize the metastable InOx layers. The InOx overlayers with distinct chemistry from their free counterpart can be confined on various oxide surfaces, demonstrating the important confinement effect at oxide/oxide interfaces.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38363352

RESUMO

Glioma is one of the most common malignancies of the central nervous system. The therapeutic effect has not been satisfactory despite advances in comprehensive treatment techniques. Our previous studies have found that triptolide inhibits glioma proliferation through the ROS/JNK pathway, but in-depth mechanisms need to be explored. Recent studies have confirmed that miRNAs may function as tumor suppressor genes or oncogenes and be involved in cancer development and progression. In this study, we found that let-7b-5p expression levels closely correlated with WHO grades and overall survival in patients in tumor glioma-CGGA-mRNAseq-325, and the upregulation of let-7b-5p can inhibit the proliferation and induce apoptosis of glioma cells. Functionally, upregulation of let-7b-5p increased the inhibitory effect on cell viability and colony formation caused by triptolide and promoted the apoptosis rate of triptolide-treated U251 cells. Conversely, downregulation of let-7b-5p had the opposite effect, indicating that let-7b-5p is a tumor suppressor miRNA in glioma cells. Moreover, target prediction, luciferase reporter assays and functional experiments revealed that IGF1R was a direct target of let-7b-5p. In addition, upregulation of IGF1R reversed the triptolide-regulated inhibition of cell viability but promoted glioma cell apoptosis and activated the ROS/JNK signaling pathway induced by triptolide. The results obtained in vivo experiments substantiated those from the in vitro experiments. In summary, the current study provides evidence that triptolide inhibits the growth of glioma cells by regulating the let-7b-5p-IGF1R-ROS/JNK axis in vitro and in vivo. These findings may provide new ideas and potential targets for molecularly targeted therapies for comprehensive glioma treatment.

4.
BMC Musculoskelet Disord ; 25(1): 127, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38341564

RESUMO

OBJECTIVES: To Investigate the value of 3D printed guide-assisted percutaneous management of minimally displaced scaphoid waist fractures(Herbert's B2) with delayed diagnosis or presentation. METHODS: From October 2018 to February 2022, 10 patients with established delayed diagnoses and presentation of minimally displaced scaphoid waist fractures were treated with 3D printed guides assisted with percutaneous internal fixation without bone grafting. This technique was based on the patient's preoperative CT and imported into the software. Based on Boolean subtraction, the most centralized screw placement position was identified and a customized guide was produced. Intraoperative percutaneous insertion of the guide wire was assisted by the custom guide. RESULTS: All 10 patients were successful in one attempt. The fractures healed at a mean of 7.7 weeks postoperatively (range 6-10 weeks). At a mean follow-up of 7.7 months (6-13 months), patients had excellent recovery of wrist function with minimal pain reduction. There were no major postoperative complications and the patients all returned to their previous activities before the injury. CONCLUSIONS: Percutaneous internal fixation based on 3D printed guides is a safe and effective technique for delayed diagnosis or presentation of patients with minimally displaced fractures of the scaphoid waist. This method allows for easy insertion of screws and avoids multiple attempts.


Assuntos
Fraturas Ósseas , Traumatismos da Mão , Osso Escafoide , Traumatismos do Punho , Humanos , Diagnóstico Tardio , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Fixação Interna de Fraturas/métodos , Traumatismos do Punho/cirurgia , Parafusos Ósseos , Osso Escafoide/diagnóstico por imagem , Osso Escafoide/cirurgia , Osso Escafoide/lesões , Impressão Tridimensional
5.
Planta ; 259(2): 50, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38285114

RESUMO

MAIN CONCLUSION: The oxidosqualene cyclases (OSCs) generating triterpenoid skeletons in Cyclocarya paliurus were identified for the first time, and two uridine diphosphate (UDP)-glycosyltransferases (UGTs) catalyzing the glycosylation of flavonoids were characterized. Cyclocarya paliurus, a native rare dicotyledonous plant in China, contains an abundance of triterpenoid saponins and flavonoid glycosides that exhibit valuable pharmaceutical effects in preventing hypertension, hyperlipidemia, and diabetes. However, the molecular mechanism explaining the biosynthesis of triterpenoid saponin and flavonoid glycoside in C. paliurus remains unclear. In this study, the triterpene content in different tissues and the expression pattern of genes encoding the key enzymes associated with triterpenoid saponin and flavonoid glycoside biosynthesis were studied using transcriptome and metabolome analysis. The eight upstream oxidosqualene cyclases (OSCs) involved in triterpenoid saponin biosynthesis were functionally characterized, among them CpalOSC6 catalyzed 2,3;22,23-dioxidosqualene to form 3-epicabraleadiol; CpalOSC8 cyclized 2,3-oxidosqualene to generate dammarenediol-II; CpalOSC2 and CpalOSC3 produced ß-amyrin and CpalOSC4 produced cycloartenol, while CpalOSC2-CpalOSC5, CpalOSC7, and CpalOSC8 all produced lanosterol. However, no catalytic product was detected for CpalOSC1. Moreover, two downstream flavonoid uridine diphosphate (UDP)-glycosyltransferases (UGTs) (CpalUGT015 and CpalUGT100) that catalyze the last step of flavonoid glycoside biosynthesis were functionally elucidated. These results uncovered the key genes involved in the biosynthesis of triterpenoid saponins and flavonoid glycosides in C. paliurus that could be applied to produce flavonoid glycosides and key triterpenoid saponins in the future via a synthetic strategy.


Assuntos
Saponinas , Esqualeno/análogos & derivados , Triterpenos , Glicosídeos , Flavonoides , Saponinas/genética , Glicosiltransferases , Difosfato de Uridina
6.
Psychophysiology ; : e14530, 2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38282093

RESUMO

In research with event-related potentials (ERPs), aggressive filters can substantially improve the signal-to-noise ratio and maximize statistical power, but they can also produce significant waveform distortion. Although this tradeoff has been well documented, the field lacks recommendations for filter cutoffs that quantitatively address both of these competing considerations. To fill this gap, we quantified the effects of a broad range of low-pass filter and high-pass filter cutoffs for seven common ERP components (P3b, N400, N170, N2pc, mismatch negativity, error-related negativity, and lateralized readiness potential) recorded from a set of neurotypical young adults. We also examined four common scoring methods (mean amplitude, peak amplitude, peak latency, and 50% area latency). For each combination of component and scoring methods, we quantified the effects of filtering on data quality (noise level and signal-to-noise ratio) and waveform distortion. This led to recommendations for optimal low-pass and high-pass filter cutoffs. We repeated the analyses after adding artificial noise to provide recommendations for data sets with moderately greater noise levels. For researchers who are analyzing data with similar ERP components, noise levels, and participant populations, using the recommended filter settings should lead to improved data quality and statistical power without creating problematic waveform distortion.

7.
Psychophysiology ; : e14511, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38165059

RESUMO

Eyeblinks and other large artifacts can create two major problems in event-related potential (ERP) research, namely confounds and increased noise. Here, we developed a method for assessing the effectiveness of artifact correction and rejection methods in minimizing these two problems. We then used this method to assess a common artifact minimization approach, in which independent component analysis (ICA) is used to correct ocular artifacts, and artifact rejection is used to reject trials with extreme values resulting from other sources (e.g., movement artifacts). This approach was applied to data from five common ERP components (P3b, N400, N170, mismatch negativity, and error-related negativity). Four common scoring methods (mean amplitude, peak amplitude, peak latency, and 50% area latency) were examined for each component. We found that eyeblinks differed systematically across experimental conditions for several of the components. We also found that artifact correction was reasonably effective at minimizing these confounds, although it did not usually eliminate them completely. In addition, we found that the rejection of trials with extreme voltage values was effective at reducing noise, with the benefits of eliminating these trials outweighing the reduced number of trials available for averaging. For researchers who are analyzing similar ERP components and participant populations, this combination of artifact correction and rejection approaches should minimize artifact-related confounds and lead to improved data quality. Researchers who are analyzing other components or participant populations can use the method developed in this study to determine which artifact minimization approaches are effective in their data.

8.
Food Funct ; 15(2): 747-765, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38117188

RESUMO

Bacillus probiotics exhibit considerable economic potential owing to their heightened resilience to external stressors and relatively lower costs related to production and preservation. Although Bacillus paralicheniformis has been acknowledged as a plant-promoting bacterium for a long time, understanding its potential as a probiotic is still in its nascent stages. In this study, the safety and probiotic characteristics of a strain of HMPM220325, isolated from artisanal fruit dairy products, were examined through whole-genome sequencing and phenotypic analysis. The whole genome of HMPM220325 was analyzed for antimicrobial resistance genes, pathogenicity factors, and genes associated with probiotic traits including stress resistance, spore formation, gut adhesion, competitive exclusion of pathogens, bacteriocin expression, and carbohydrate metabolism related to prebiotic utilization. Also, wet lab experiments were conducted for the characterization of probiotics. The identification of the organism as B. paralicheniformis was verified. Its safety was assessed through in silico analysis, the haemolytic activity test, and the acute oral toxicity test. B. paralicheniformis HMPM220325 demonstrated its ability to survive in the pH range of 4-10 and bile salt concentrations of 0-0.9% (w/v), tolerate temperatures between 20 and 60 °C, and exhibit a robust antioxidant capacity. Moreover, B. paralicheniformis HMPM220325 demonstrated a moderate level of hydrophobicity, had the ability to form biofilms, achieved a self-aggregation rate of 51.77 ± 1.01% within 6 hours, and successfully colonized the mouse intestine for a duration of up to 17 days. Additionally, the genome of B. paralicheniformis HMPM220325 contains three gene clusters associated with the biosynthesis of bacteriocins and exhibits co-aggregation with Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica serovar Typhimurium. The findings of the genomic analysis align with those obtained from the experimental investigation, thereby substantiating the potential of B. paralicheniformis HMPM220325 as a probiotic suitable for incorporation in dairy functional foods and feed applications.


Assuntos
Bacillus , Bacteriocinas , Probióticos , Animais , Camundongos , Frutas/metabolismo , Bacillus/genética , Bacillus/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Laticínios , Probióticos/química
9.
J Math Biol ; 87(6): 81, 2023 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-37930452

RESUMO

In this paper, we are concerned with two SIS epidemic reaction-diffusion models with mass action infection mechanism of the form SI, and study the spatial profile of population distribution as the movement rate of the infected individuals is restricted to be small. For the model with a constant total population number, our results show that the susceptible population always converges to a positive constant which is indeed the minimum of the associated risk function, and the infected population either concentrates at the isolated highest-risk points or aggregates only on the highest-risk intervals once the highest-risk locations contain at least one interval. In sharp contrast, for the model with a varying total population number which is caused by the recruitment of the susceptible individuals and death of the infected individuals, our results reveal that the susceptible population converges to a positive function which is non-constant unless the associated risk function is constant, and the infected population may concentrate only at some isolated highest-risk points, or aggregate at least in a neighborhood of the highest-risk locations or occupy the whole habitat, depending on the behavior of the associated risk function and even its smoothness at the highest-risk locations. Numerical simulations are performed to support and complement our theoretical findings.


Assuntos
Epidemias , Humanos , Difusão , Modelos Epidemiológicos , Movimento
10.
Nat Commun ; 14(1): 7907, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38036536

RESUMO

Pyroelectric energy harvesting has received increasing attention due to its ability to convert low-grade waste heat into electricity. However, the low output energy density driven by low-grade temperature limits its practical applications. Here, we show a high-performance hybrid BNT-BZT-xGaN thermal energy harvesting system with environmentally friendly lead-free BNT-BZT pyroelectric matrix and high thermal conductivity GaN as dopant. The theoretical analysis of BNT-BZT and BNT-BZT-xGaN with x = 0.1 wt% suggests that the introduction of GaN facilitates the resonance vibration between Ga and Ti, O atoms, which not only contributes to the enhancement of the lattice heat conduction, but also improves the vibration of TiO6 octahedra, resulting in simultaneous improvement of thermal conductivity and pyroelectric coefficient. Therefore, a thermoelectric coupling enhanced energy harvesting density of 80 µJ cm-3 has been achieved in BNT-BZT-xGaN ceramics with x = 0.1 wt% driven by a temperature variation of 2 oC, at the optical load resistance of 600 MΩ.

11.
Chin Med J (Engl) ; 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37963586

RESUMO

BACKGROUND: T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), an inhibitory receptor expressed on T cells, plays a dysfunctional role in antiviral infection and antitumor activity. However, it is unknown whether TIGIT expression on T cells influences the immunological effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccines. METHODS: Forty-five people living with HIV (PLWH) on antiretroviral therapy (ART) for more than two years and 31 healthy controls (HCs), all received a third dose of a SARS-CoV-2 inactivated vaccine, were enrolled in this study. The amounts, activation, proportion of cell subsets, and magnitude of the SARS-CoV-2-specific immune response of TIGIT+CD4+ and TIGIT+CD8+ T cells were investigated before the third dose but 6 months after the second vaccine dose (0W), 4 weeks (4W) and 12 weeks (12W) after the third dose. RESULTS: Compared to that in HCs, the frequency of TIGIT+ CD8+ T cells in the peripheral blood of PLWH increased at 12W after the third dose of the inactivated vaccine, and the immune activation of TIGIT+CD8+ T cells also increased. A decrease in the ratio of both T naïve (TN) and central memory (TCM) cells among TIGIT+CD8+ T cells and an increase in the ratio of the effector memory (TEM) subpopulation were observed at 12W in PLWH. Interestingly, particularly at 12W, a higher proportion of TIGIT+CD8+ T cells expressing CD137 and CD69 simultaneously was observed in HCs than in PLWH based on the activation-induced marker assay. Compared with 0W, SARS-CoV-2-specific TIGIT+CD8+ T-cell responses in PLWH were not enhanced at 12W but were enhanced in HCs. Additionally, at all time points, the SARS-CoV-2-specific responses of TIGIT+CD8+ T cells in PLWH were significantly weaker than those of TIGIT-CD8+ T cells. However, in HCs, the difference in the SARS-CoV-2-specific responses induced between TIGIT+CD8+ T cells and TIGIT-CD8+ T cells was insignificant at 4W and 12W, except at 0W. CONCLUSION: TIGIT expression on CD8+ T cells may hinder the T-cell immune response to a booster dose of an inactivated SARS-CoV-2 vaccine, suggesting weakened resistance to SARS-CoV-2 infection, especially in PLWH. Furthermore, TIGIT may be used as a potential target to increase the production of SARS-CoV-2-specific CD8+ T cells, thereby enhancing the effectiveness of vaccination.

12.
Opt Express ; 31(23): 38024-38037, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38017920

RESUMO

We propose a method to achieve a strong indirect interaction between two distant whispering-gallery-mode (WGM) resonators in a hybrid quantum system at room temperature, even when the distance between them exceeds 40 wavelengths. By exploiting the quantum critical point, we can greatly enhance both the effective damping rate and the coupling strengths between a WGM resonator and a low-frequency polariton. We introduce a large effective frequency detuning to suppress the effective damping rate while maintaining the enhanced coupling strength. The strong indirect interaction between separated WGM resonators is mediated by a far-off-resonant low-frequency polariton through virtual excitations in a process similar to Raman process. This proposal provides a viable approach to building a quantum network based on strongly coupled WGM resonators.

13.
Chin Med J (Engl) ; 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38018259

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine can induce a potent cellular and humoral immune response to protect against SARS-CoV-2 infection. However, it was unknown whether SARS-CoV-2 vaccination can induce effective natural killer (NK) cell response in people living with human immunodeficiency virus (PLWH) and healthy individuals. METHODS: Forty-seven PLWH and thirty healthy controls (HCs) inoculated with SARS-CoV-2 inactivated vaccine were enrolled from Beijing Youan Hospital in this study. The effect of SARS-CoV-2 vaccine on NK cell frequency, phenotype, and function in PLWH and HCs was evaluated by flow cytometry, and the response of NK cells to SARS-CoV-2 Omicron Spike (SARS-2-OS) protein stimulation was also evaluated. RESULTS: SARS-CoV-2 vaccine inoculation elicited activation and degranulation of NK cells in PLWH, which peaked at 2 weeks and then decreased to a minimum at 12 weeks after the third dose of vaccine. However, in vitro stimulation of the corresponding peripheral blood monocular cells from PLWH with SARS-2-OS protein did not upregulate the expression of the aforementioned markers. Additionally, the frequencies of NK cells expressing the activation markers CD25 and CD69 in PLWH were significantly lower than those in HCs at 0, 4 and 12 weeks, but the percentage of CD16+ NK cells in PLWH was significantly higher than that in HCs at 2, 4 and 12 weeks after the third dose of vaccine. Interestingly, the frequency of CD16+ NK cells was significantly negatively correlated with the proportion of CD107a+ NK cells in PLWH at each time point after the third dose. Similarly, this phenomenon was also observed in HCs at 0, 2, and 4 weeks after the third dose. Finally, regardless of whether NK cells were stimulated with SARS-2-OS or not, we did not observe any differences in the expression of NK cell degranulation markers between PLWH and HCs. CONCLUSIONS: SARS-CoV-2 vaccine elicited activation and degranulation of NK cells, indicating that the inoculation of SARS-CoV-2 vaccine enhances NK cell response.

14.
Cell Rep Med ; 4(11): 101257, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37918406

RESUMO

The definitive diagnosis of non-alcoholic steatohepatitis (NASH) currently relies on invasive and labor-intensive liver biopsy. Here, we identified soluble CUB domain-containing protein 1 (sCDCP1) as a top-ranked non-invasive biomarker for NASH using Olink-based proteomics in 238 obese individuals with liver biopsies. Both the circulating concentration and hepatic mRNA abundance of sCDCP1 were significantly elevated in patients with NASH and correlated closely with each histological feature of NASH. In the pooled multicenter validation cohort, sCDCP1 as a standalone biomarker achieved an area under the receiver operating characteristic (AUROC) of 0.838 (95% confidence interval [CI] 0.789-0.887) for diagnosing NASH, which is better than those achieved with cytokeratin-18 and other non-invasive tests. Furthermore, the C-DAG model established by the combination of sCDCP1 with diabetes, aspartate aminotransferase (AST), and gender accurately rules in and rules out both NASH and fibrotic NASH (gray zones <20%). Thus, sCDCP1-based non-invasive tests can be potentially implemented for screening and early diagnosis of NASH and for ruling out low-risk individuals to avoid unnecessary liver biopsies.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/patologia , População do Leste Asiático , Obesidade/diagnóstico , Biomarcadores , Medição de Risco , Antígenos de Neoplasias , Moléculas de Adesão Celular
15.
Mol Hortic ; 3(1): 11, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37789448

RESUMO

Medicinal plants represent a huge reservoir of secondary metabolites (SMs), substances with significant pharmaceutical and industrial potential. However, obtaining secondary metabolites remains a challenge due to their low-yield accumulation in medicinal plants; moreover, these secondary metabolites are produced through tightly coordinated pathways involving many spatiotemporally and environmentally regulated steps. The first regulatory layer involves a complex network of transcription factors; a second, more recently discovered layer of complexity in the regulation of SMs is epigenetic modification, such as DNA methylation, histone modification and small RNA-based mechanisms, which can jointly or separately influence secondary metabolites by regulating gene expression. Here, we summarize the findings in the fields of genetic and epigenetic regulation with a special emphasis on SMs in medicinal plants, providing a new perspective on the multiple layers of regulation of gene expression.

16.
Life (Basel) ; 13(10)2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37895482

RESUMO

Panax notoginseng (Burk.) F.H. Chen is a species of the Araliaceae family that inhabits southwestern China, Burma, and Nepal. It is cultivated on a commercial scale in Yunnan province, China, owing to its significance in traditional Chinese medicine. Panax notoginseng roots are usually yellow-white (HS); however, purple roots (ZS) have also been reported. The majority of P. notoginseng research has concentrated on the identification and production of natural chemicals in HS; however, there is little to no information about the composition of ZS. Using UPLC-MS/MS, we investigated the global metabolome profile of both ZS- and HS-type roots and discovered 834 metabolites from 11 chemical groups. There were 123 differentially accumulated metabolites (DAM) in the HS and ZS roots, which were classified as lipids and lipid-like molecules, polyketides, organoheterocyclic chemicals, and organooxygen compounds. We investigated the associated compounds in the DAMs because of the importance of anthocyanins in color and saponins and ginsenosides in health benefits. In general, we discovered that pigment compounds such as petunidin 3-glucoside, delphinidin 3-glucoside, and peonidin-3-O-beta-galactoside were more abundant in ZS. The saponin (eight compounds) and ginsenoside (26 compounds) content of the two varieties of roots differed as well. Transcriptome sequencing revealed that flavonoid and anthocyanin production genes were more abundant in ZS than in HS. Similarly, we found differences in gene expression in genes involved in terpenoid production and related pathways. Overall, these findings suggest that the purple roots of P. notoginseng contain varying amounts of ginsenosides and anthocyanins compared to roots with a creamy yellow color.

17.
bioRxiv ; 2023 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-37745415

RESUMO

Eyeblinks and other large artifacts can create two major problems in event-related potential (ERP) research, namely confounds and increased noise. Here, we developed a method for assessing the effectiveness of artifact correction and rejection methods at minimizing these two problems. We then used this method to assess a common artifact minimization approach, in which independent component analysis (ICA) is used to correct ocular artifacts, and artifact rejection is used to reject trials with extreme values resulting from other sources (e.g., movement artifacts). This approach was applied to data from five common ERP components (P3b, N400, N170, mismatch negativity, and error-related negativity). Four common scoring methods (mean amplitude, peak amplitude, peak latency, and 50% area latency) were examined for each component. We found that eyeblinks differed systematically across experimental conditions for several of the components. We also found that artifact correction was reasonably effective at minimizing these confounds, although it did not usually eliminate them completely. In addition, we found that the rejection of trials with extreme values was effective at reducing noise, with the benefits of eliminating these trials outweighing the reduced number of trials available for averaging. For researchers who are analyzing similar ERP components and participant populations, this combination of artifact correction and rejection should minimize artifact-related confounds and lead to improved data quality. Researchers who are analyzing other components or participant populations can use the method developed in this study to determine which artifact minimization approaches are effective in their data.

18.
Appl Opt ; 62(21): 5666-5674, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37707183

RESUMO

A reconfigurable metasurface with a switchable function, broad band, high efficiency, and ultra-compact size is crucial for the development of efficient and compact devices. We propose a bifunctional metasurface that utilizes vanadium dioxide (V O 2) and graphene to achieve high-efficiency absorption and polarization conversion (PC) in the terahertz (THz) range. In our design, an extra dielectric layer is added on the top of V O 2 and graphene. It is worth pointing out that the presence of the additional dielectric layer greatly enhances the coupling of the wave in the Fabry-Perot cavity, resulting in remarkable improvement in absorption and PC efficiency. Furthermore, by controlling the working state of V O 2 and graphene, the functionality of the metasurface can be flexibly switched among absorption, cross-polarized conversion, and linear-to-circular PC (LTC). Simulation results indicate that the metasurface works in the absorption mode when V O 2 is in a metal state, and it can efficiently absorb THz waves at 2.0-7.0 THz with a remarkable relative bandwidth of 111.1%. Furthermore, the absorption is over 98.4% under a normal incident case and still maintains over 90% with an incident angle of 50° at 2.8-7.0 THz. Importantly, by changing the conductivity of V O 2, the absorption can be flexibly adjusted, allowing for tuning the absorption between 10% and 98.4%. When V O 2 is in an insulator state, the function of the designed metasurface is altered to PC mode, and it can efficiently convert incident linearly polarized (LP) waves into cross-polarized waves with a PC ratio exceeding 95% at 1.8-3.4 THz when the Fermi level of graphene is 1 eV. When switched to the LTC mode, it can convert incident LP waves into right-circularly polarized waves with ellipticity less than -0.95 at 1.7-2.1 THz and into left-circularly polarized waves with ellipticity greater than 0.90 at 2.7-3.0 THz when the Fermi level of graphene is 0.55 eV.

19.
ACS Appl Mater Interfaces ; 15(35): 41880-41891, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37625156

RESUMO

Recent advancements have introduced anisotropic structures, particularly 2D nanosheets, into aerogels, resulting in unique morphologies and exceptional properties that differ from those assembled by isotropic nanoparticles. However, exploration of the distinct porous networks and the resulting properties is limited. We focus on rare earth yttria (Y2O3) aerogels as a case in point and demonstrate the synthesis of aerogels with nanosheet and nanoparticle assemblies using elaborative sol-gel chemistry. With the aid of X-ray computed tomography, three-dimensional visualizations of the aerogels provide relative compressive views of the porous network, revealing that the Y2O3 aerogel assembled by nanosheets possesses a hierarchical pore structure characterized by uneven pore distribution, particularly the presence of macropores throughout; in contrast, these consist of nanoparticles exhibiting a relative uniform pore distribution. High-temperature examinations indicate that the nanosheet aerogels are much more stable with a specific surface area of 64 m2·g-1 after being exposed at 1300 °C; meanwhile, the aerogels present durable and efficient thermal insulation performances. The exceptional thermal properties are attributed to the synergistic effects of the nanosheets' crystalline nature and the hierarchical porous network. The nanosheet Y2O3 aerogel also exhibited superior luminescent emission characteristics, further enhancing its potential for various applications. Our findings provide further insights into optimization of the microstructures in nanoporous aerogels, particularly through the utilization of anisotropic nanosheets.

20.
Nutrients ; 15(15)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37571278

RESUMO

Early growth has long-lasting associations with adult metabolic health. However, the association of adiposity with cardiometabolic risk factors in toddlers remains poorly understood. This study aimed to examine the association of maternal prenatal factors and child adiposity with child cardiometabolic risk factors among boys and girls aged 2 years. This was a birth cohort study of 549 term-born children in Shanghai, China, with follow-up data at the age of 2-years. Child anthropometric and adiposity measurements included weight, length, and skinfold thickness (triceps, subscapular, and abdominal). Child cardiometabolic risk factors included random morning plasma glucose, serum insulin, lipids, and systolic and diastolic blood pressure (SBP, DBP). At 2 years, overweight/obesity (weight-for-length z score, ZWFL > 2) was associated with 12.6 (95%CI 7.7, 17.4) mmHg higher SBP, and 7.9 (4.1, 11.8) mmHg higher DBP in boys, with similar results observed in girls. Maternal hypertensive disorders of pregnancy were associated with 3.0 (0.1, 5.8) higher SBP, 3.17 (0.90, 5.44) mmHg higher DBP, 0.24 (0.01,0.47) mmol/L higher plasma glucose, and 0.26 (0.01,0.51) mmol/L higher serum triglycerides after adjustment for child age, sex, and ZWFL. Maternal hypertensive disorders of pregnancy and child overweight/obesity were associated with higher SBP and DBP at the age of 2 years.


Assuntos
Hipertensão Induzida pela Gravidez , Obesidade Pediátrica , Pré-Eclâmpsia , Feminino , Humanos , Masculino , Gravidez , Adiposidade/fisiologia , Glicemia , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Fatores de Risco Cardiometabólico , China/epidemiologia , Estudos de Coortes , População do Leste Asiático , Sobrepeso , Obesidade Pediátrica/complicações , Obesidade Pediátrica/epidemiologia , Fatores de Risco , Pré-Escolar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...