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1.
Sensors (Basel) ; 24(6)2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38544053

RESUMO

The carbon-fiber-reinforced polymer (CFRP) bending structure is widely used in aviation. The emergence and spread of delamination damage will decrease the safety of in-service bending structures. Lamb waves can effectively identify delamination damage as a high-damage-sensitivity detection tool. For this present study, the signal difference coefficient (SDC) was introduced to quantify delamination damage and evaluate the sensitivity of A0-mode and S0-mode Lamb waves to delamination damage. The simulation results show that compared with the S0-mode Lamb wave, the A0-mode Lamb wave exhibits higher delamination damage sensitivity. The delamination damage can be quantified based on the strong correlation between the SDC and the delamination damage size. The control effect of the linear array PZT phase time-delay method on the Lamb wave mode was investigated by simulation. The phase time-delay method realizes the generation of a single-mode Lamb wave, which can separately excite the A0-mode and S0-mode Lamb wave to identify delamination damage of different sizes. The A0-mode Lamb wave was excited by the developed one-dimensional miniaturized linear comb transducer (LCT), which was used to conduct the detection experiment on the CFRP bending plate with delamination damage sizes of Φ6.0 mm, Φ10.0 mm, and Φ15.0 mm. The experimental results verify the correctness of the simulation. According to the Hermite interpolation results of the finite-element simulation data, the relationship between the delamination damage size and the SDC was fitted by the Gaussian function and Rational function, which can accurately quantify the delamination damage. The absolute error of the delamination damage quantification with Gaussian and Rational fitting expression does not exceed 0.8 mm and 0.7 mm, and the percentage error is not more than 8% and 7%. The detection and signal processing methods employed in the present research are easy to operate and implement, and accurate delamination damage quantification results have been obtained.

2.
Molecules ; 29(3)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38338387

RESUMO

Trilobatin (TBL) is a key sweet compound from the traditional Chinese sweet tea plant (Rubus suavissimus S. Lee). Because of its intense sweetness, superior taste profile, and minimal caloric value, it serves as an exemplary natural dihydrochalcone sweetener. It also has various health benefits, including anti-inflammatory and glucose-lowering effects. It is primarily produced through botanical extraction, which impedes its scalability and cost-effectiveness. In a novel biotechnological approach, phloretin is used as a precursor that is transformed into TBL by the glycosyltransferase enzyme ph-4'-OGT. However, this enzyme's low catalytic efficiency and by-product formation limit the large-scale synthesis of TBL. In our study, the enzyme Mdph-4'-OGT was used to screen 17 sequences across species for TBL synthesis, of which seven exhibited catalytic activity. Notably, PT577 exhibited an unparalleled 97.3% conversion yield within 3 h. We then optimized the reaction conditions of PT577, attaining a peak TBL bioproduction of 163.3 mg/L. By employing virtual screening, we identified 25 mutation sites for PT577, thereby creating mutant strains that reduced by-products by up to 50%. This research enhances the enzymatic precision for TBL biosynthesis and offers a robust foundation for its industrial-scale production, with broader implications for the engineering and in silico analysis of glycosyltransferases.


Assuntos
Flavonoides , Glicosiltransferases , Polifenóis , Glicosiltransferases/genética , Antioxidantes , Edulcorantes
3.
J Nat Prod ; 85(8): 1918-1927, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-35951980

RESUMO

Interference of microtubule dynamics with tubulin-targeted drugs is a validated approach for cancer chemotherapy. Moroidin (1) is an Urticaceae-type cyclopeptide having a potent inhibitory effect on purified tubulin polymerization. So far, moroidin has not been chemically synthesized, and its effect on cancer cells remains unknown. Herein, the cyclopeptide moroidin was isolated and identified from the seeds of Celosia cristata, and a revised assignment of its NMR data was presented. For the first time, moroidin (1) was demonstrated as having cytotoxic effects for several cancer cells, especially A549 lung cancer cells. The cellular evidence obtained showed that moroidin disrupts microtubule polymerization and decreases ß-tubulin protein levels, but is not as potent as colchicine. Molecular docking indicated that 1 has a high binding potential to the vinca alkaloid site on tubulin. Moreover, moroidin arrested A549 cells in the G2/M phase and induced cell apoptosis. The intrinsic mitochondrial pathway and AKT were involved in the moroidin-induced cell apoptosis. In addition, moroidin (1) inhibited the migration and invasion of A549 cells at sublethal concentrations.


Assuntos
Antineoplásicos , Celosia , Neoplasias Pulmonares , Células A549 , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Celosia/metabolismo , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Simulação de Acoplamento Molecular , Peptídeos Cíclicos/química , Sementes/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacologia
4.
BMC Plant Biol ; 21(1): 531, 2021 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-34773981

RESUMO

BACKGROUND: The leaf is a determinate organ essential for photosynthesis, whose size and shape determine plant architecture and strongly affect agronomic traits. In soybean, the molecular mechanism of leaf development is not well understood. The flowering repressor gene E1, which encodes a legume-specific B3-like protein, is known to be the gene with the largest influence on soybean flowering and maturity. However, knowledge of its potential other functions remains poor. RESULTS: Here, we identified a novel function of E1 protein in leaf development. Unifoliolate leaves of E1-overexpression (E1-OE) lines were smaller and curlier than those of wild type DongNong 50 (DN50) and Williams 82 (W82). Transverse histological sections showed disorganized cells and significantly elevated palisade tissue number, spongy tissue number, and bulliform cell number in E1-OE lines. Our results indicate that E1 binds to the promoters of the leaf- development-related CINCINNATA (CIN)-like TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factor genes to negatively regulate their expression. CONCLUSIONS: Our findings identify E1 as an important new factor in soybean leaf development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Glycine max/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Glycine max/genética , Fatores de Transcrição/genética
5.
Anal Bioanal Chem ; 408(2): 629-37, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26521180

RESUMO

A rapid and sensitive method for the determination of immunosuppressive drugs through surface-assisted laser desorption/ionization mass spectrometric detection (SALDI/MS) was developed. Colloidal Pd and α-cyano-4-hydroxycinnamic acid (CHCA) were used as the SALDI co-matrix. To eliminate interference and enhance the sensitivity, dispersive liquid-liquid microextraction (DLLME) was employed to extract the immunosuppressive drugs from the aqueous solutions. Under optimal extraction and detection conditions, calibration curves for cyclosporine and everolimus in aqueous solutions were linear over a concentration range from 0.01 to 1.20 µM. For sirolimus, the linear concentration range of the calibration curve was from 0.05 to 2.00 µM. The limits of detection (LODs) were calculated to be 3, 3, and 14 nM for cyclosporine, everolimus, and sirolimus, respectively. The enrichment factors of DLLME were calculated to be 108, 122, and 101 for cyclosporine, everolimus, and sirolimus, respectively. This novel method was successfully applied for the determination of immunosuppressive drugs in human urine and serum samples.


Assuntos
Imunossupressores/sangue , Imunossupressores/urina , Microextração em Fase Líquida/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Humanos , Imunossupressores/isolamento & purificação , Limite de Detecção
6.
Rapid Commun Mass Spectrom ; 29(21): 1977-83, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26443396

RESUMO

RATIONALE: Rivaroxaban is a new anticoagulant drug that has recently been introduced for clinical applications. To ensure optimum efficacy while minimizing the risk of toxicity and other adverse effects, a simple and sensitive analytical procedure for monitoring the concentration of rivaroxaban in biological fluids is required. METHODS: Rivaroxaban was extracted from aqueous solutions by dispersive liquid-liquid microextraction (DLLME). Detection of rivaroxaban was achieved through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using colloidal palladium as the SALDI matrix. RESULTS: The calibration curve for rivaroxaban in aqueous solutions was linear over the concentration range from 5 to 500 nM. The limit of detection (LOD) for rivaroxaban at a signal-to-noise ratio of 3 was 2 nM. With a sample-to-extract volume ratio of 200, the enrichment factors were calculated to be 141. This method was successfully applied for the determination of rivaroxaban in human urine and serum samples. The LODs for rivaroxaban in urine and serum were calculated to be 6 nM and 60 nM, respectively. CONCLUSIONS: The analysis speed, together with the ease of operation and high sensitivity, allows SALDI-MS method to be particularly suitable for the high-throughput screening of rivaroxaban levels in human urine and serum samples.


Assuntos
Anticoagulantes/sangue , Anticoagulantes/urina , Rivaroxabana/sangue , Rivaroxabana/urina , Espectrometria de Massas por Ionização por Electrospray/métodos , Humanos , Paládio/química
7.
Psychophysiology ; 60(12): e14385, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37424455

RESUMO

Studies of emotion regulation to-date have mostly focused on negative emotion down-regulation, leaving positive emotion up-regulation poorly understood, particularly regarding factors that may modulate its success. While reappraisal and savoring have been shown to be effective at increasing electrocortical and subjective response to pictures in controlled laboratory settings, it remains unclear whether individuals can effectively enact these techniques to willfully increase positive emotions in everyday life when faced with other concurrent distractions/demands. Here, we used the late positive potential (LPP), an electrocortical measure that is larger for emotional compared to neutral stimuli, to assess the effect of working memory (WM) load on individuals' ability to reappraise or savor positive pictures. Seventy-six participants were randomly assigned to use either reappraisal or savoring to up-regulate positive emotion to pictures. Following training, participants engaged in a positive emotion up-regulation task interspersed with high and low WM load trials, while EEG was recorded. Frequentist and Bayesian statistics showed that although high WM load seemed to consume resources and reduced picture processing overall, it did not interfere with the enhancement of the LPP via positive emotion up-regulation. Nonetheless, WM performance (especially on high-load trials) was worse when participants were engaged in positive emotion up-regulation. Therefore, while both techniques appear to be effective under concurrent WM load, positive emotion up-regulation may interfere with other ongoing tasks.


Assuntos
Regulação Emocional , Memória de Curto Prazo , Humanos , Memória de Curto Prazo/fisiologia , Potenciais Evocados/fisiologia , Eletroencefalografia , Teorema de Bayes , Regulação para Cima , Emoções/fisiologia
8.
Diabetol Metab Syndr ; 15(1): 170, 2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37592322

RESUMO

BACKGROUND: Several observational cohorts and meta-analytical studies on humans have shown that users of sodium-glucose cotransporter-2 inhibitors (SGLT2is) have a lower risk for new-onset acute coronary syndrome (ACS) than nonusers. However, some studies, including randomized clinical trials, reported the opposite results. This study aimed to investigate the impacts of a SGLT2i on new-onset ACS in a population. METHODS: We conducted a retrospective population-based cohort study involving 56,356 subjects who received SGLT2i therapy and 112,712 patients who did not receive SGLT2i therapy between May 1, 2016 and December 31, 2019. The outcome was the risk of new-onset ACS. Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals for associations between SGLT2i use and ACS risk. RESULTS: A total of 670 and 1408 ACS events occurred in SGLT2i users and nonusers, respectively, during a follow-up of 3.7 years. SGLT2i use was associated with a nonsignificantly lower risk of ACS (adjusted HR 0.95, 95%confidence intervals (CI 0.87-1.04, P = 0.3218). We confirmed the robustness of these results through a propensity score 1:1 matching analysis. The results of the subgroup analysis of the subtype of the SGLT2i treatments were consistent with the main findings. An increased risk for the incidence of ACS in male and older (> 70 years) patients were also found. CONCLUSIONS: In this population-based cohort study, we found that SGLT2i use is associated with a nonsignificantly decreased risk of ACS. No difference in the SGLT2i subtype was observed in subgroup analyses. However, the results of this study indicated an increased risk for the incidence of ACS in male and older (> 70 years) patients.

9.
Behav Res Ther ; 165: 104310, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37040669

RESUMO

OBJECTIVE: This study is a non-randomized pragmatic trial to assess the feasibility and acceptability of the Primary Care Intervention for Posttraumatic stress disorder (PCIP) (Srivastava et al., 2021), an Integrated Behavioral Health Care treatment for PTSD in adolescents. METHOD: Following routine clinic procedures, youth who were suspected of having trauma-related mental health symptoms were referred by their primary care providers to integrated care social workers for evaluation. The integrated care social workers referred the first 23 youth whom they suspected of having PTSD to the research study. Twenty youth consented to the study and 19 completed the pre-assessment (17 female; mean age = 19.32, SD = 2.11; range 14-22 years). More than 40% identified as Black and a third as Hispanic/Latinx. PCIP mechanisms and clinical outcomes were assessed pre- and post-treatment, and at one-month follow-up. Participants and therapists completed post-treatment qualitative interviews to assess feasibility and acceptability, and treatment sessions were audio recorded to assess fidelity. RESULTS: Findings suggest high acceptability, satisfaction, and feasibility of the PCIP delivered in "real-life" safety net pediatric primary care. Integrated care social workers had high treatment fidelity. Despite the small sample size, there was significant improvement in symptom scores of anxiety (g = 0.68, p = 0.02) and substance use (g = 0.36, p = 0.04) from pre to post, and depression symptoms (g = 0.38, p = 0.04) from pre to follow-up. Qualitative data from patients who completed exit interviews and integrated social workers indicated high satisfaction with the treatment, with some participants reporting that the integrated intervention was more acceptable and less stigmatizing than seeking mental health care outside of primary care. CONCLUSIONS: The PCIP may improve treatment engagement and access for vulnerable youth. Promising findings of high acceptability, feasibility, and initial clinical effectiveness suggest that PCIP warrants larger-scale study as part of routine care in pediatric integrated care.


Assuntos
Transtornos de Estresse Pós-Traumáticos , Humanos , Feminino , Adolescente , Criança , Adulto Jovem , Adulto , Transtornos de Estresse Pós-Traumáticos/terapia , Estudos de Viabilidade , Serviços de Saúde , Transtornos de Ansiedade , Atenção Primária à Saúde
10.
Behav Res Ther ; 150: 104031, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35032699

RESUMO

Distraction is typically discouraged during exposure therapy for anxiety, because it is thought to interfere with extinction learning by diverting attention away from anxiety-provoking stimuli. Working memory load is one form of distraction that might interfere with extinction learning. Alternatively, working memory load might reduce threat responding and benefit extinction learning by engaging prefrontal brain regions that have a reciprocal relationship with brain circuits involved in threat detection and processing. Prior work examining the effect of working memory load on threat extinction has been limited and has found mixed results. Here, we used the late positive potential (LPP), an event-related potential that is larger for threatening compared to non-threatening stimuli to assess the effect of working memory load on threat extinction. After acquisition, 38 participants performed three blocks of an extinction task interspersed with low and high working memory load trials. Results showed that overall, the LPP was reduced under high compared to low working memory load, and that working memory load slowed extinction learning. Results provide empirical evidence in support of limiting distraction during exposure therapy in order to optimize extinction learning efficiency.


Assuntos
Eletroencefalografia , Memória de Curto Prazo , Ansiedade/terapia , Atenção , Potenciais Evocados , Humanos
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