Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 158
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Nature ; 601(7894): 531-536, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34847568

RESUMEN

Quantum many-body systems display rich phase structure in their low-temperature equilibrium states1. However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases2-8 that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC)7,9-15. Concretely, dynamical phases can be defined in periodically driven many-body-localized (MBL) systems via the concept of eigenstate order7,16,17. In eigenstate-ordered MBL phases, the entire many-body spectrum exhibits quantum correlations and long-range order, with characteristic signatures in late-time dynamics from all initial states. It is, however, challenging to experimentally distinguish such stable phases from transient phenomena, or from regimes in which the dynamics of a few select states can mask typical behaviour. Here we implement tunable controlled-phase (CPHASE) gates on an array of superconducting qubits to experimentally observe an MBL-DTC and demonstrate its characteristic spatiotemporal response for generic initial states7,9,10. Our work employs a time-reversal protocol to quantify the impact of external decoherence, and leverages quantum typicality to circumvent the exponential cost of densely sampling the eigenspectrum. Furthermore, we locate the phase transition out of the DTC with an experimental finite-size analysis. These results establish a scalable approach to studying non-equilibrium phases of matter on quantum processors.


Asunto(s)
Frío , Transición de Fase , Termodinámica
2.
Nature ; 574(7779): 505-510, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31645734

RESUMEN

The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor1. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits2-7 to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 253 (about 1016). Measurements from repeated experiments sample the resulting probability distribution, which we verify using classical simulations. Our Sycamore processor takes about 200 seconds to sample one instance of a quantum circuit a million times-our benchmarks currently indicate that the equivalent task for a state-of-the-art classical supercomputer would take approximately 10,000 years. This dramatic increase in speed compared to all known classical algorithms is an experimental realization of quantum supremacy8-14 for this specific computational task, heralding a much-anticipated computing paradigm.

3.
Phys Rev Lett ; 132(10): 100603, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38518348

RESUMEN

Measurement is an essential component of quantum algorithms, and for superconducting qubits it is often the most error prone. Here, we demonstrate model-based readout optimization achieving low measurement errors while avoiding detrimental side effects. For simultaneous and midcircuit measurements across 17 qubits, we observe 1.5% error per qubit with a 500 ns end-to-end duration and minimal excess reset error from residual resonator photons. We also suppress measurement-induced state transitions achieving a leakage rate limited by natural heating. This technique can scale to hundreds of qubits and be used to enhance the performance of error-correcting codes and near-term applications.

4.
Eur J Nucl Med Mol Imaging ; 51(2): 581-589, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37819451

RESUMEN

PURPOSE: The objective of this study was to evaluate the diagnostic performance and image quality of total-body positron emission tomography/computed tomography (PET/CT) imaging using a half-dose of [68 Ga]Ga-prostate specific membrane antigen ([68 Ga]Ga-PSMA) radiotracer, compared to conventional short axial field-of-view PET/CT imaging using a full dose of [68 Ga]Ga-PSMA. METHODS: This retrospective study enrolled 52 patients with biochemical recurrent (BCR) prostate cancer after radical prostatectomy who underwent total-body PET/CT with a half-dose (0.9-1.1 MBq/kg) of [68 Ga]Ga-PSMA. These patients were matched by baseline characteristics to another 52 BCR patients after prostatectomy who underwent conventional PET/CT with a full dose (1.8-2.2 MBq/kg) of [68 Ga]Ga-PSMA. The half-dose group was further divided into 5-min (G5) and 2-min (G2) acquisition subgroups. Image quality was assessed through subjective analysis using a 5-point scale and objective measurements of standard uptake value maximum (SUVmax), standard uptake value mean (SUVmean), background variation (BV) of the liver, blood pool, and parotid glands. Additionally, SUVmax and tumor-to-background ratio (TBR) were calculated for lesions. RESULTS: No significant difference in subjective image quality was found between the G2 and full-dose groups (p > 0.05). PET/CT image quality was significantly higher for the G5 versus G2 (p < 0.001) and full-dose groups (p < 0.001). TBR did not differ between the G2 and full-dose groups (4.23 ± 5.21 vs 4.22 ± 3.97, p = 0.99). Liver BV was significantly lower for G2 versus full-dose groups (0.16 ± 0.03 vs 0.20 ± 0.05, p < 0.001). CONCLUSIONS: Total-body PET/CT with a half-dose [68 Ga]Ga-PSMA yields image quality superior or comparable to that of conventional PET/CT. The utilization of total-body [68 Ga]Ga-PSMA PET/CT meets the diagnostic demands of BCR patients, particularly those who exhibit reduced tolerance to prolonged horizontal positioning and scan durations, while simultaneously reducing radiation exposure for the subjects.


Asunto(s)
Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Masculino , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Estudios Retrospectivos , Recurrencia Local de Neoplasia/diagnóstico por imagen , Recurrencia Local de Neoplasia/patología , Neoplasias de la Próstata/patología , Radioisótopos de Galio , Ácido Edético
5.
Environ Health ; 23(1): 64, 2024 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-39003460

RESUMEN

BACKGROUND: Brominated Flame Retardants (BFRs) have attracted widespread concern due to their environmental persistence and potential toxicity. This study aims to examine the association between BFRs exposure and hypertension. METHODS: We used data from the National Health and Nutrition Examination Survey (NHANES) spanning 2005 to 2016 for the cross-sectional analysis. To evaluate the individual and combined impacts of BFRs exposure on hypertension, we utilized multivariate models, including generalized additive models, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models. RESULTS: 9882 individuals (48% male) aged ≥ 20 were included in the final analysis, of whom 4114 had hypertension. After controlling for potential covariates, higher serum concentrations of PBDE100 (OR: 1.26; 95% CI: 1.01, 1.57) and PBDE153 (OR: 1.50; 95% CI: 1.18, 1.88) were significantly associated with hypertension. A nonlinear relationship between PBDE28 and hypertension was observed (P = 0.03). Moreover, BFRs mixture were positively associated with the prevalence of hypertension in both the WQS (ß:1.09; 95% CI: 1.02, 1.17; P = 0.02) and BKMR models. CONCLUSION: Our study suggested that BFRs exposure is positively associated with hypertension in the general population. To confirm this association and elucidate the mechanisms, further research is required.


Asunto(s)
Exposición a Riesgos Ambientales , Contaminantes Ambientales , Retardadores de Llama , Éteres Difenilos Halogenados , Hipertensión , Encuestas Nutricionales , Humanos , Retardadores de Llama/análisis , Femenino , Masculino , Hipertensión/epidemiología , Hipertensión/inducido químicamente , Adulto , Persona de Mediana Edad , Éteres Difenilos Halogenados/sangre , Estudios Transversales , Exposición a Riesgos Ambientales/efectos adversos , Contaminantes Ambientales/sangre , Estados Unidos/epidemiología , Adulto Joven , Anciano , Bifenilos Polibrominados/sangre
6.
Artículo en Inglés | MEDLINE | ID: mdl-38607223

RESUMEN

Objective: This study evaluates the effects of valve surgery on safety and cardiac function in patients with valvular heart disease complicated by pulmonary arterial hypertension (PAH), focusing on postoperative outcomes influenced by age, heart function grade, and PAH severity. Methods: A retrospective analysis was conducted on 307 valve surgery patients from April 2017 to April 2022. The cohort had a mean age of 57.6 years, with 56.9% males, and was stratified by NYHA functional class II-IV. Outcomes assessed included mortality, complication rates, left ventricular ejection fraction (LVEF), and pulmonary artery systolic pressure (PASP), with statistical analysis performed using t-tests and chi-square tests for continuous and categorical data, respectively. Results: Postoperative outcomes varied significantly with age, NYHA class, and PASP grade. Patients aged ≤60 exhibited an average PASP reduction of 44.46% in the male group and 44.44% in the female group and an LVEF improvement of 5.28% in the male group and 5.80% in the female group. However, these patients showed a higher risk of postoperative complications, such as renal failure, arrhythmia, low cardiac output syndrome, respiratory insufficiency, (23.31%), and a higher mortality rate (13.53%)(P < .05). Higher NYHA classes correlated with increased postoperative risks of complications and mortality rates, and elevated PASP grades were associated with larger improvements in PASP and LVEF but also higher postoperative risks. Conclusion: Valve surgery in valvular heart disease with PAH is influenced by patient age, functional status, and PAH severity. Despite advances in surgical techniques, there remains a notable gap in understanding the nuanced interplay between these conditions and the variable outcomes of valve surgery. This study addresses this research gap, offering comprehensive insights into how age, heart function, and PAH severity influence postoperative outcomes. These findings are crucial for clinicians, providing a more informed basis for tailored treatment strategies, and ultimately enhancing patient care in this complex clinical scenario.Healthcare providers should consider the age-specific benefits and risks of valve surgery in patients with valvular heart disease and pulmonary arterial hypertension. Tailored decision-making, particularly for those aged ≤60, higher NYHA classes, or severe PAH, is essential for optimizing individual outcomes.

7.
Sensors (Basel) ; 24(11)2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38894197

RESUMEN

Spatialization and analysis of the gross domestic product of second and tertiary industries (GDP23) can effectively depict the socioeconomic status of regional development. However, existing studies mainly conduct GDP spatialization using nighttime light data; few studies specifically concentrated on the spatialization and analysis of GDP23 in a built-up area by combining multi-source remote sensing images. In this study, the NPP-VIIRS-like dataset and Sentinel-2 multi-spectral remote sensing images in six years were combined to precisely spatialize and analyze the variation patterns of the GDP23 in the built-up area of Zibo city, China. Sentinel-2 images and the random forest (RF) classification method based on PIE-Engine cloud platform were employed to extract built-up areas, in which the NPP-VIIRS-like dataset and comprehensive nighttime light index were used to indicate the nighttime light magnitudes to construct models to spatialize GDP23 and analyze their change patterns during the study period. The results found that (1) the RF classification method can accurately extract the built-up area with an overall accuracy higher than 0.90; the change patterns of built-up areas varied among districts and counties, with Yiyuan county being the only administrative region with an annual expansion rate of more than 1%. (2) The comprehensive nighttime light index is a viable indicator of GDP23 in the built-up area; the fitted model exhibited an R2 value of 0.82, and the overall relative errors of simulated GDP23 and statistical GDP23 were below 1%. (3) The year 2018 marked a significant turning point in the trajectory of GDP23 development in the study area; in 2018, Zhoucun district had the largest decrease in GDP23 at -52.36%. (4) GDP23 gradation results found that Zhangdian district exhibited the highest proportion of high GDP23 (>9%), while the proportions of low GDP23 regions in the remaining seven districts and counties all exceeded 60%. The innovation of this study is that the GDP23 in built-up areas were first precisely spatialized and analyzed using the NPP-VIIRS-like dataset and Sentinel-2 images. The findings of this study can serve as references for formulating improved city planning strategies and sustainable development policies.

8.
Angew Chem Int Ed Engl ; 63(26): e202404945, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38624193

RESUMEN

Herein, we disclose that pyridinium salts derived from abundant (hetero)anilines represent a novel precursor class for nucleophilic aromatic substitution reactions with [18F]fluoride. The value of this new 18F-fluorodeamination is demonstrated with the synthesis of over 30 structurally diverse and complex heteroaryl 18F-fluorides, several derived from scaffolds that were yet to be labelled with fluorine-18. The protocol tolerates heteroarenes and functionalities commonly found in drug discovery libraries, and is amenable to scale-up and automation on a commercial radiosynthesiser.


Asunto(s)
Compuestos de Anilina , Radioisótopos de Flúor , Compuestos de Piridinio , Sales (Química) , Compuestos de Anilina/química , Compuestos de Piridinio/química , Compuestos de Piridinio/síntesis química , Sales (Química)/química , Radioisótopos de Flúor/química , Halogenación , Estructura Molecular
9.
J Am Chem Soc ; 145(17): 9708-9717, 2023 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-37079853

RESUMEN

The controlled programming of regiochemical outcomes in nucleophilic fluorination reactions with alkali metal fluoride is a problem yet to be solved. Herein, two synergistic approaches exploiting hydrogen bonding catalysis are presented. First, we demonstrate that modulating the charge density of fluoride with a hydrogen-bond donor urea catalyst directly influences the kinetic regioselectivity in the fluorination of dissymmetric aziridinium salts with aryl and ester substituents. Moreover, we report a urea-catalyzed formal dyotropic rearrangement, a thermodynamically controlled regiochemical editing process consisting of C-F bond scission followed by fluoride rebound. These findings offer a route to access enantioenriched fluoroamine regioisomers from a single chloroamine precursor, and more generally, new opportunities in regiodivergent asymmetric (bis)urea-based organocatalysis.

10.
J Gene Med ; 25(3): e3468, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36518003

RESUMEN

BACKGROUND: It is difficult to distinguish between arrhythmogenic cardiomyopathy (ACM) and dilated cardiomyopathy (DCM) because of their similar clinical manifestations. This study aimed to develop a novel diagnostic algorithm for distinguishing ACM from DCM. METHODS: Two public datasets containing human ACM and DCM myocardial samples were used. Consensus clustering, non-negative matrix factorization and principal component analysis were applied. Weighted gene co-expression network analysis and machine learning methods, including random forest and the least absolute shrinkage and selection operator, were used to identify candidate genes. Receiver operating characteristic curves and nomograms were performed to estimate diagnostic efficacy, and Spearman's correlation analysis was used to assess the correlation between candidate genes and cardiac function indices. RESULTS: Both ACM and DCM showed highly similar gene expression patterns in the clustering analyses. Hub gene modules associated with cardiomyopathy were obtained using weighted gene co-expression network analysis. Thirteen candidate genes were selected using machine learning algorithms, and their combination showed a high diagnostic value (area under the ROC curve = 0.86) for distinguishing ACM from DCM. In addition, TATA-box binding protein associated factor 15 showed a negative correlation with cardiac index (R = -0.54, p = 0.0054) and left ventricular ejection fraction (R = -0.48, p = 0.0015). CONCLUSIONS: Our study revealed an effective diagnostic model with key gene signatures, which indicates a potential tool to differentiate between ACM and DCM in clinical practice. In addition, we identified several genes that are highly related to cardiac function, which may contribute to our understanding of ACM and DCM.


Asunto(s)
Cardiomiopatías , Cardiomiopatía Dilatada , Humanos , Cardiomiopatía Dilatada/genética , Volumen Sistólico , Función Ventricular Izquierda , Perfilación de la Expresión Génica , Algoritmos , Aprendizaje Automático
11.
Opt Express ; 31(4): 5229-5241, 2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36823809

RESUMEN

Integrated third-harmonic generators enable on-chip wavelength conversion translating telecom signals to the visible spectrum. Despite the desirable functionality, the device performance is susceptible to phase distortions. Here, we present a design method of compensating the Kerr-induced distortions in third-harmonic generation. The design method yields a chirped Bragg grating theoretically improving the conversion efficiency by ∼30 dB. We envision the design method will pave the way for demonstrating efficient infrared-to-visible upconversion in silicon nitride chips.

12.
Opt Express ; 31(9): 15000-15014, 2023 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-37157352

RESUMEN

The quantum theory of optical coherence plays a ubiquitous role in identifying optical emitters. An unequivocal identification, however, presumes that the photon number statistics is resolved from timing uncertainties. We demonstrate from first principle that the observed nth-order temporal coherence is a n-fold convolution of the instrument responses and the expected coherence. The consequence is detrimental in which the photon number statistics is masked from the unresolved coherence signatures. The experimental investigations are thus far consistent with the theory developed. We envision the present theory will mitigate the false identification of optical emitters and enlarge the coherence deconvolution to an arbitrary order.

13.
Eur J Nucl Med Mol Imaging ; 50(13): 4096-4106, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37578502

RESUMEN

PURPOSE: The purpose of this study was to assess whether total-body [68 Ga]Ga-PSMA-11 PET/CT could improve the detection rate compared with conventional [68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer. METHODS: Two hundred biochemical recurrent prostate cancer patients with similar clinicopathological characteristics were included, of whom 100 patients underwent early total-body [68 Ga]Ga-PSMA-11 PET/CT and diuretic-delayed total-body [68 Ga]Ga-PSMA-11 PET/CT, and the other 100 patients received early conventional [68 Ga]Ga-PSMA-11 PET/CT and diuretic-delayed conventional [68 Ga]Ga-PSMA-11 PET/CT. The detection rates of total-body [68 Ga]Ga-PSMA-11 PET/CT and conventional [68 Ga]Ga-PSMA-11 PET/CT were compared using a chi-square test and stratified analysis. The image quality of total-body [68 Ga]Ga-PSMA PET/CT and conventional [68 Ga]Ga-PSMA-11 PET/CT was compared based on subjective scoring and objective parameters. Subjective scoring was conducted from background noise and lesion prominence using a 5-point scale. Objective parameters were evaluated by SUVmax, SUVmean, the standard deviation (SD) of SUV, and the signal-to-noise ratio (SNR) of liver and gluteus maximus. The SUVmax of the recurrent lesions was also measured. RESULTS: The liver SD of the total-body [68 Ga]Ga-PSMA-11 PET/CT was significantly lower than that of conventional [68 Ga]Ga-PSMA-11 PET/CT, the SNR was significantly higher than that of conventional [68 Ga]Ga-PSMA-11 PET/CT, and the subjective evaluation was significantly better than that of conventional [68 Ga]Ga-PSMA-11 PET/CT. The detection rate of total-body [68 Ga]Ga-PSMA PET/CT for biochemical recurrence of prostate cancer was significantly higher than that of conventional [68 Ga]Ga-PSMA-11 PET/CT (91.0% vs. 74.0%, P = 0.003). Total-body [68 Ga]Ga-PSMA-11 PET/CT had better detection efficiency for patients with a Gleason score ≤ 8 or PSA ≤ 2 ng/ml. The advantages of diuretic-delayed total-body [68 Ga]Ga-PSMA-11 PET/CT were more obvious. CONCLUSION: Total-body [68 Ga]Ga-PSMA-11 PET/CT could significantly improve the detection rate compared with conventional [68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer.


Asunto(s)
Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Masculino , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Isótopos de Galio , Radioisótopos de Galio , Recurrencia Local de Neoplasia/diagnóstico por imagen , Oligopéptidos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Diuréticos , Ácido Edético
14.
Eur J Nucl Med Mol Imaging ; 50(13): 3961-3969, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37535107

RESUMEN

BACKGROUND: [68Ga]Ga-FAPI-04 (gallium-68-labeled fibroblast activation protein inhibitor-04) PET/CT has been widely used in diagnosing malignant tumors. Total-body PET/CT has a long axial field of view and provides higher sensitivity compared to traditional PET/CT. However, whether the reduced injected dose of [68Ga]Ga-FAPI-04 could obtain qualified imaging has not been evaluated. PURPOSE: To explore the effect of half-dose [68Ga]Ga-FAPI-04 on image quality and tumor detectability in oncology patients. METHODS: A total of twenty-seven patients with tumors or clinically suspected tumors were included, and all patients were scanned with total-body PET/CT after an injected dose of 0.84-1.14 MBq/kg [68Ga]Ga-FAPI-04. All patients obtained superior image quality with 300 s original acquisition time. Images were reconstructed using 180 s, 120 s, 60 s, 40 s, 30 s, 20 s scanning duration by ordered subset expectation maximization algorithm. The subjective image quality of all patients in each time group was scored using 5-point Likert scale. Mediastinal blood pool, liver, spleen, and muscle were analyzed as background using semi-quantitative parameters maximum standardized uptake values (SUVmax), mean standardized uptake values (SUVmean), standard deviation (SD), and signal to noise ratio (SNR). The lesion detection rate, SUVmax, and tumor-to-background ratio (TBR) were calculated for tumors confirmed by pathology. RESULTS: The subjective image quality score decreased with the shortening of scanning time; however, both 180 s and 120 s images met the diagnostic requirements in terms of overall quality, lesion conspicuity, and image noise. The SUVmax of background increased with the reduction of scanning time, while the SUVmean was relatively stable. With the shortening of scanning time, the SD gradually increased, and the SNR gradually decreased, which was consistent with subjective image quality scores. In 180 s and 120 s images, all 11 primary lesions and 79 metastatic lesions were detected. The SUVmax of tumor focus showed an increasing trend as same as the background. Compared with 300 s, the TBR muscle had no statistical difference in 180 s and 120 s. CONCLUSIONS: Half-dose [68Ga]Ga-FAPI-04 in total-body PET/CT imaging can shorten the acquisition time to 120 s with acceptable subjective image quality and 100% tumor detection rate. Total-body PET/CT imaging with a half-dose [68Ga]Ga-FAPI-04 and reduced acquisition time can be used in radiation-sensitive and poor tolerant to prolong horizontal positioning and waiting time populations such as children and gravidas.


Asunto(s)
Neoplasias , Quinolinas , Niño , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estudios de Factibilidad , Radioisótopos de Galio , Neoplasias/diagnóstico por imagen , Fluorodesoxiglucosa F18
15.
Mol Psychiatry ; 27(12): 4843-4860, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36028570

RESUMEN

Feeding behavior is regulated by both the homeostatic needs of the body and hedonic values of the food. Easy access to palatable energy-dense foods and the consequent obesity epidemic stress the urgent need for a better understanding of neural circuits that regulate hedonic feeding. Here, we report that neurotensin-positive neurons in the lateral septum (LSNts) play a crucial role in regulating hedonic feeding. Silencing LSNts specifically promotes feeding of palatable food, whereas activation of LSNts suppresses overall feeding. LSNts neurons project to the tuberal nucleus (TU) via GABA signaling to regulate hedonic feeding, while the neurotensin signal from LSNts→the supramammillary nucleus (SUM) is sufficient to suppress overall feeding. In vivo calcium imaging and optogenetic manipulation reveal two populations of LSNts neurons that are activated and inhibited during feeding, which contribute to food seeking and consumption, respectively. Chronic activation of LSNts or LSNts→TU is sufficient to reduce high-fat diet-induced obesity. Our findings suggest that LSNts→TU is a key pathway in regulating hedonic feeding.


Asunto(s)
Conducta Alimentaria , Área Hipotalámica Lateral , Conducta Alimentaria/fisiología , Neuronas/metabolismo , Neurotensina/metabolismo , Obesidad/metabolismo , Animales , Ratones , Área Hipotalámica Lateral/fisiología
16.
Artículo en Inglés | MEDLINE | ID: mdl-37155004

RESUMEN

BACKGROUND: Prolonged use of anti-arrhythmic drugs (AAD) beyond the post-ablation blanking period to maintain sinus rhythm has been adopted in clinical practice but without sufficient evidence. Dronedarone is an AAD valid for maintaining sinus rhythm with fewer side effects than other AAD for long-term use. OBJECTIVE: We sought to investigate the effect of prolonged use of dronedarone on the recurrence of non-paroxysmal AF patients beyond 3 months within the first year after ablation. METHODS: Non-paroxysmal AF patients will receive dronedarone for 3 months after radiofrequency ablation. Patients without drug side effects and atrial tachyarrhythmia (AT) recurrence will then be randomly divided into dronedarone and placebo groups and followed up until 1 year after ablation. The primary endpoint is the cumulative nonrecurrence rate post 3 months to 1 year after ablation. Patients will receive 7-day Holter monitoring (ECG patch) at 6, 9, and 12 months after ablation to evaluate AT recurrence. Secondary endpoints include dronedarone withdrawal due to side effects or intolerance of AT recurrence, time to the first recurrence, repeat ablation, electrical cardioversion, unscheduled emergency room visit, or re-hospitalization. CONCLUSION: This trial will evaluate whether prolonged use of dronedarone effectively reduces the recurrence rate after ablation in non-paroxysmal AF patients. The result of this trial will provide evidence for optimizing post-ablation anti-arrhythmic therapy. TRIAL REGISTRATION: ClinicalTrials.gov ; NCT05655468, 19-December-2022.

17.
J Nanobiotechnology ; 21(1): 257, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37550736

RESUMEN

BACKGROUND: Stabilization and increased activity of hypoxia-inducible factor 1-α (HIF-1α) can directly increase cancellous bone formation and play an essential role in bone modeling and remodeling. However, whether an increased HIF-1α expression in adipose-derived stem cells (ADSCs) increases osteogenic capacity and promotes bone regeneration is not known. RESULTS: In this study, ADSCs transfected with small interfering RNA and HIF-1α overexpression plasmid were established to investigate the proliferation, migration, adhesion, and osteogenic capacity of ADSCs and the angiogenic ability of human umbilical vein endothelial cells (HUVECs). Overexpression of HIF-1α could promote the biological functions of ADSCs, and the angiogenic ability of HUVECs. Western blotting showed that the protein levels of osteogenesis-related factors were increased when HIF-1α was overexpressed. Furthermore, the influence of upregulation of HIF-1α in ADSC sheets on osseointegration was evaluated using a Sprague-Dawley (SD) rats implant model, in which the bone mass and osteoid mineralization speed were evaluated by radiological and histological analysis. The overexpression of HIF-1α in ADSCs enhanced bone remodeling and osseointegration around titanium implants. However, transfecting the small interfering RNA (siRNA) of HIF-1α in ADSCs attenuated their osteogenic and angiogenic capacity. Finally, it was confirmed in vitro that HIF-1α promotes osteogenic differentiation and the biological functions in ADSCs via the VEGF/AKT/mTOR pathway. CONCLUSIONS: This study demonstrates that HIF-1α has a critical ability to promote osteogenic differentiation in ADSCs by coupling osteogenesis and angiogenesis via the VEGF/AKT/mTOR signaling pathway, which in turn increases osteointegration and bone formation around titanium implants.


Asunto(s)
Subunidad alfa del Factor 1 Inducible por Hipoxia , Osteogénesis , Proteínas Proto-Oncogénicas c-akt , Animales , Humanos , Ratas , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Neovascularización Fisiológica , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , ARN Interferente Pequeño , Transducción de Señal , Titanio , Serina-Treonina Quinasas TOR/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo
18.
Hereditas ; 160(1): 36, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37904201

RESUMEN

BACKGROUND: RNA modifications, especially N6-methyladenosine, N1-methyladenosine and 5-methylcytosine, play an important role in the progression of cardiovascular disease. However, its regulatory function in dilated cardiomyopathy (DCM) remains to be undefined. METHODS: In the study, key RNA modification regulators (RMRs) were screened by three machine learning models. Subsequently, a risk prediction model for DCM was developed and validated based on these important genes, and the diagnostic efficiency of these genes was assessed. Meanwhile, the relevance of these genes to clinical traits was explored. In both animal models and human subjects, the gene with the strongest connection was confirmed. The expression patterns of important genes were investigated using single-cell analysis. RESULTS: A total of 4 key RMRs were identified. The risk prediction models were constructed basing on these genes which showed a good accuracy and sensitivity in both the training and test set. Correlation analysis showed that insulin-like growth factor binding protein 2 (IGFBP2) had the highest correlation with left ventricular ejection fraction (LVEF) (R = -0.49, P = 0.00039). Further validation expression level of IGFBP2 indicated that this gene was significantly upregulated in DCM animal models and patients, and correlation analysis validation showed a significant negative correlation between IGFBP2 and LVEF (R = -0.87; P = 6*10-5). Single-cell analysis revealed that this gene was mainly expressed in endothelial cells. CONCLUSION: In conclusion, IGFBP2 is an important biomarker of left ventricular dysfunction in DCM. Future clinical applications could possibly use it as a possible therapeutic target.


Asunto(s)
Cardiomiopatía Dilatada , Disfunción Ventricular Izquierda , Humanos , Biomarcadores , Cardiomiopatía Dilatada/genética , Cardiomiopatía Dilatada/diagnóstico , Células Endoteliales , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina , ARN , Volumen Sistólico , Disfunción Ventricular Izquierda/genética , Función Ventricular Izquierda
19.
Ecotoxicol Environ Saf ; 264: 115412, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37714034

RESUMEN

BACKGROUND: Volatile organic compounds (VOCs) contain hundreds of chemicals and human exposure to VOCs is pervasive. However, most studies have considered only a single chemical or a class of similar chemicals. OBJECTIVE: We aimed to investigate the association between urinary volatile organic compound metabolites (mVOCs) and the risk of cardiovascular disease (CVD) in the general population. METHODS: The data in this study were collected from the National Health and Nutrition Examination Survey in 2011-2018. Eligible patients were aged ≥20 years for whom complete data for 20 types of urinary mVOCs and CVD outcomes were available. Multivariate logistic regression models were used to elucidate the association between mVOCs and CVD. Generalized additive models were used to examine the nonlinear relationships between mVOCs and CVD. RESULTS: 6814 indiviuals were included in the final analysis, of whom 508 had CVD. Higher urinary concentrations of N-acetyl-S-(2-carboxyethyl)-L-cysteine (CEMA) and N-Acetyl-S-(2-cyanoethyl)-l-cysteine (CYMA) and a lower urinary concentration of 2-aminothiazoline-4-carboxylic acid (ATCA) were associated with CVD outcomes after the adjustment for potential confounding factors. A nonlinear relationship and a threshold effect were only observed between N-acetyl-S-(N-methylcarbamoyl)-l-cysteine (AMCC) and CVD among 20 types of mVOCs. There was a significantly positive correlation between AMCC and CVD when AMCC concentration was >2.32 g/mL. CONCLUSION: The findings of this study suggested a significant correlation between urinary VOC metabolites and CVD. Urinary mVOCs may indicate hazardous exposure or distinct metabolic traits in patients with CVD.


Asunto(s)
Enfermedades Cardiovasculares , Compuestos Orgánicos Volátiles , Humanos , Compuestos Orgánicos Volátiles/metabolismo , Encuestas Nutricionales , Enfermedades Cardiovasculares/epidemiología , Acetilcisteína
20.
Drug Dev Res ; 84(2): 296-311, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36644989

RESUMEN

Small molecule covalent drugs have proved to be desirable therapies especially on drug resistance related to point mutations. Secondary mutations of FLT3 have become the main mechanism of FLT3 inhibitors resistance which further causes the failure of treatment. Herein, a series of 4-(4-aminophenyl)-6-phenylisoxazolo[3,4-b]pyridine-3-amine covalent derivatives were synthesized and optimized to overcome the common secondary resistance mutations of FLT3. Among these derivatives, compound F15 displayed potent inhibition activities against FLT3 (IC50 = 123 nM) and FLT3-internal tandem duplication (ITD) by 80% and 26.06%, respectively, at the concentration of 1 µM. Besides, F15 exhibited potent activity against FLT3-dependent human acute myeloid leukemia (AML) cell lines MOLM-13 (IC50 = 253 nM) and MV4-11 (IC50 = 91 nM), as well as BaF3 cells with variety of secondary mutations. Furthermore, cellular mechanism assays indicated that F15 inhibited phosphorylation of FLT3 and its downstream signaling factors. Notably, F15 could be considered for further development as potential drug candidate to treat AML.


Asunto(s)
Antineoplásicos , Leucemia Mieloide Aguda , Humanos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridinas/farmacología , Aminas/farmacología , Leucemia Mieloide Aguda/tratamiento farmacológico , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/farmacología , Tirosina Quinasa 3 Similar a fms/uso terapéutico , Apoptosis , Proliferación Celular
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA