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1.
Langmuir ; 40(24): 12671-12680, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38853520

RESUMO

The design of single-atom nanozymes with dual active sites to increase their activity and for the detection and degradation of contaminants is rare and challenging. In this work, a single-atom nanozyme (FeCu-NC) based on a three-dimensional porous Fe/Cu dual active site was developed as a colorimetric sensor for both the quantitative analysis of isoniazid (INH) and the efficient degradation of levofloxacin (LEV). FeCu-NC was synthesized using a salt template and freeze-drying method with a three-dimensional hollow porous structure and dual active sites (Fe-Nx and Cu-Nx). In terms of morphology and structure, FeCu-NC exhibits excellent peroxidase-like activity and catalytic properties. Therefore, a colorimetric sensor was constructed around FeCu-NC for sensitive and rapid quantitative analysis of INH with a linear range of 0.9-10 µM and a detection limit as low as 0.3 µM, and the sensor was successfully applied to the analysis of INH in human urine. In addition, FeCu-NC promoted the efficient degradation of LEV by peroxymonosulfate activation, with a degradation rate of 90.4% for LEV at 30 min. This work sheds new light on the application of single-atom nanozymes to antibiotics for colorimetric sensing and degradation.


Assuntos
Cobre , Ferro , Isoniazida , Levofloxacino , Isoniazida/química , Isoniazida/análise , Levofloxacino/urina , Levofloxacino/análise , Levofloxacino/química , Ferro/química , Cobre/química , Humanos , Peroxidase/química , Peroxidase/metabolismo , Colorimetria/métodos , Nanoestruturas/química , Catálise
2.
Nano Lett ; 23(19): 9026-9033, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37767914

RESUMO

The quantum Hall effect is one of the exclusive properties displayed by Dirac Fermions in topological insulators, which propagates along the chiral edge state and gives rise to quantized electron transport. However, the quantum Hall effect formed by the nondegenerate Dirac surface states has been elusive so far. Here, we demonstrate the nondegenerate integer quantum Hall effect from the topological surface states in three-dimensional (3D) topological insulator ß-Ag2Te nanostructures. Surface-state dominant conductance renders quantum Hall conductance plateaus with a step of e2/h, along with typical thermopower behaviors of two-dimensional (2D) massless Dirac electrons. The 2D nature of the topological surface states is proven by the electrical and thermal transport responses under tilted magnetic fields. Moreover, the degeneracy of the surface states is removed by structure inversion asymmetry (SIA). The evidenced SIA-induced nondegenerate integer quantum Hall effect in low-symmetry ß-Ag2Te has implications for both fundamental study and the realization of topological magneto-electric effects.

3.
Cell Mol Biol Lett ; 28(1): 62, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37525118

RESUMO

BACKGROUND: Bladder cancer (BLCA) is a malignancy that frequently metastasizes and leads to poor patient prognosis. It is essential to understand the molecular mechanisms underlying the progression and metastasis of BLCA and identify potential biomarkers. METHODS: The expression of peptidase inhibitor 16 (PI16) was analysed using quantitative PCR, immunoblotting and immunohistochemistry assays. The functional roles of PI16 were evaluated using wound healing, transwell, and human umbilical vein endothelial cell tube formation assays, as well as in vivo tumour models. The effects of PI16 on nuclear factor κB (NF-κB) signalling activation were examined using luciferase reporter gene systems, immunoblotting and immunofluorescence assays. Co-immunoprecipitation was used to investigate the interaction of PI16 with annexin-A1 (ANXA1) and NEMO. RESULTS: PI16 expression was downregulated in bladder cancer tissues, and lower PI16 levels correlated with disease progression and poor survival in patients with BLCA. Overexpressing PI16 inhibited BLCA cell growth, motility, invasion and angiogenesis in vitro and in vivo, while silencing PI16 had the opposite effects. Mechanistically, PI16 inhibited the activation of the NF-κB pathway by interacting with ANXA1, which inhibited K63 and M1 ubiquitination of NEMO. CONCLUSIONS: These results indicate that PI16 functions as a tumour suppressor in BLCA by inhibiting tumour growth and metastasis. Additionally, PI16 may serve as a potential biomarker for metastatic BLCA.


Assuntos
NF-kappa B , Neoplasias da Bexiga Urinária , Humanos , NF-kappa B/metabolismo , Inibidores de Proteases , Transdução de Sinais , Ubiquitinação , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , Linhagem Celular Tumoral , Proteínas de Transporte/genética , Glicoproteínas/genética , Glicoproteínas/metabolismo
4.
Br J Cancer ; 127(2): 211-222, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35484216

RESUMO

BACKGROUND: Patients with metastatic bladder cancer have very poor prognosis and predictive biomarkers are urgently needed for early clinical detection and intervention. In this study, we evaluate the effect and mechanism of Suprabasin (SBSN) on bladder cancer metastasis. METHODS: A tissue array was used to detect SBSN expression by immunohistochemistry. A tumour-bearing mouse model was used for metastasis evaluation in vivo. Transwell and wound-healing assays were used for in vitro evaluation of migration and invasion. Comprehensive molecular screening was achieved by western blotting, immunofluorescence, luciferase reporter assay, and ELISA. RESULTS: SBSN was found markedly overexpressed in bladder cancer, and indicated poor prognosis of patients. SBSN promoted invasion and metastasis of bladder cancer cells both in vivo and in vitro. The secreted SBSN exhibited identical biological function and regulation in bladder cancer metastasis, and the interaction of secreted SBSN and EGFR could play an essential role in activating the signalling in which SBSN enhanced the phosphorylation of EGFR and SRC kinase, followed with phosphorylation and nuclear location of STAT3. CONCLUSIONS: Our findings highlight that SBSN, and secreted SBSN, promote bladder cancer metastasis through activation of EGFR/SRC/STAT3 pathway and identify SBSN as a potential diagnostic and therapeutic target for bladder cancer.


Assuntos
Antígenos de Diferenciação/metabolismo , Neoplasias da Bexiga Urinária , Animais , Linhagem Celular Tumoral , Movimento Celular , Receptores ErbB/genética , Receptores ErbB/metabolismo , Regulação Neoplásica da Expressão Gênica , Camundongos , Metástase Neoplásica , Prognóstico , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Transdução de Sinais , Neoplasias da Bexiga Urinária/patologia , Quinases da Família src/metabolismo
5.
J Thromb Thrombolysis ; 51(1): 129-135, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32562102

RESUMO

The aim of this study was to evaluate the risk factors and characteristics of long-term postoperative left atrial (LA) thrombi after mitral valve replacement. Transthoracic echocardiography (TTE) file of 3117 consecutive patients with mitral valve replacement history was reviewed (between Jan 2006 and Feb 2019). 45 LA thrombi cases (1.4%) was identified and matched to 180 thrombi-free cases by random sampling. The median detection time of LA thrombi was 58 months (IQR, 17-144) after MV replacement. Distribution of LA thrombi included roof (n = 10), posterior wall (n = 9), appendage (n = 7), lateral wall (n = 6), anterior wall (n = 2), septum (n = 1) and multiple site (n = 10). All thrombi were sessile and immobile. The independent predictors for LA thrombi development by stepwise multiple regression analysis were the larger LA size (> 55 mm), the increased of mitral valve pressure gradient (MVPG > 6 mmHg), and the reduced of left ventricular ejection fraction (LVEF < 50%). Long-term thrombi incidence after mitral valve replacement is somewhat low. In individuals with mitral prosthetic valves, larger LA size, increased MVPG and reduced LVEF were three promising independent predictors of the insistence of LA thrombi. Furthermore, LA thrombi were sessile, immobile and widespread in the long-term postoperative period after mitral valve replacement. Close monitoring should be applied in these patients with thrombi risk.


Assuntos
Átrios do Coração/patologia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Próteses Valvulares Cardíacas/efeitos adversos , Valva Mitral/cirurgia , Trombose/etiologia , Idoso , Ecocardiografia , Feminino , Seguimentos , Átrios do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Trombose/diagnóstico por imagem , Trombose/patologia
6.
Nano Lett ; 20(10): 7004-7010, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32897723

RESUMO

Stimulated by novel properties in topological insulators, experimentally realizing quantum phases of matter and employing control over their properties have become a central goal in condensed matter physics. ß-silver telluride (Ag2Te) is predicted to be a new type narrow-gap topological insulator. While enormous efforts have been plunged into the topological nature in silver chalcogenides, sophisticated research on low-dimensional nanostructures remains unexplored. Here, we report the record-high bulk carrier mobility of 298 600 cm2/(V s) in high-quality Ag2Te nanoplates and the coexistence of the surface and bulk state from systematic Shubnikov-de Haas oscillations measurements. By tuning the correlation between the top and bottom surfaces, we can effectively enhance the contribution of the surface to the total conductance up to 87% at 130 V. These results are instrumental to the high-mobility physics study and even suitable to explore exotic topological phenomena in this material system.

7.
J Cardiovasc Electrophysiol ; 30(3): 332-338, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30575204

RESUMO

OBJECTIVE: There are scarce comparative data on efficacy and procedural safety between radiofrequency catheter ablation (RFCA) and surgical ablation (SA) combined with mitral valve (MV) surgery for patients with nonparoxysmal atrial fibrillation (AF) and moderate mitral regurgitation (MR). METHODS AND RESULTS: This single-center, retrospective, and observational study enrolled 155 consecutive patients with nonparoxysmal AF and moderate MR, of which 98 underwent RFCA and 57 underwent SA combined with MV surgery. Circumferential pulmonary vein ablation, bidirectional block of lines, and disappearance of complex fractionated atrial electrograms were the endpoints of RFCA, while pulmonary vein isolation and left and right atrial incisions were performed in SA. At median 24-month follow-up, the primary outcome of atrial tachyarrhythmia (ATa) recurrence-free rate estimated by Kaplan-Meier analysis was higher in SA + MV surgery vs RFCA groups (64.2% vs 38.3%; P = 0.002), and comparable between patients with and without MV prolapse in SA + MV surgery group (64.7% vs 63.1%; P = 0.972). In adjusted Cox model, RFCA was associated with a hazard ratio for ATa recurrence of 2.27 (95% confidence interval, 1.02-5.05; P = 0.045). Patients with higher MR jet/LA (left atrial) area ratio had a higher risk of ATa recurrence in RFCA ( P = 0.037) but not SA + MV ( P = 0.529) groups. CONCLUSION: SA + MV surgery yielded more favorable outcomes than RFCA for treating nonparoxysmal AF in patients with moderate MR. The MR jet/LA area ratio was positively associated with ATa recurrence rate in patients undergoing RFCA. MV prolapse did not affect prognosis in patients undergoing SA + MV surgery.


Assuntos
Fibrilação Atrial/cirurgia , Procedimentos Cirúrgicos Cardíacos , Ablação por Cateter , Insuficiência da Valva Mitral/cirurgia , Valva Mitral/cirurgia , Veias Pulmonares/cirurgia , Potenciais de Ação , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ablação por Cateter/efeitos adversos , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/fisiopatologia , Intervalo Livre de Progressão , Veias Pulmonares/fisiopatologia , Recidiva , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo
8.
Opt Lett ; 41(7): 1534-7, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27192280

RESUMO

We investigate the laser-induced damage performance at 1064 nm of potassium dihydrogen phosphate (KDP) crystals grown using filters of different pore sizes. The aim is to explore a novel method for understanding laser-matter interactions with regard to physical parameters affecting the ability of damage precursors to initiate damage. By reducing the pore size of filters in continuous filtration growth, we can improve laser damage resistance. Furthermore, we develop a model based on a Gaussian distribution of precursor thresholds and heat transfer to obtain a size distribution of the precursor defects. Smaller size and/or lower concentration of precursor defects could lead to better damage resistance.

9.
Opt Express ; 23(12): 16273-80, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-26193600

RESUMO

The variation of scattering and absorption in DKDP crystals by laser conditioning was investigated by combining light scattering technique and on-site transmittance measurement technique. Laser-induced disappearance of scattering defects was observed, and variation of transmittance was achieved. Using Mie theory, a kind of absorbing defects, aside from scattering defect, was discovered. Moreover, the experimental results demonstrated that the absorption of crystal could be mitigated by laser conditioning.

10.
Opt Lett ; 39(9): 2633-6, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24784064

RESUMO

A ZnO nanoparticle layer was synthesized by the sol-gel method on ITO glass. Devices with a ZnO nanoparticle layer/polymethylmethacrylate (PMMA) heterojunction structure were then fabricated and the room temperature electroluminescence (EL) spectra were studied. Under DC bias, ultraviolet (UV) EL at 390 nm from the ZnO band edge emission was observed, and defect-related emission of ZnO at 600 and 760 nm were also detected. The EL mechanisms are discussed in terms of the carrier tunneling process.

11.
Phys Rev Lett ; 112(14): 145502, 2014 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-24765985

RESUMO

By finding local minima of a thermodynamic-like potential, we generate jammed packings of frictionless spheres under constant shear stress σ and obtain the yield stress σy by sampling the potential energy landscape. For three-dimensional systems with harmonic repulsion, σy satisfies the finite size scaling with the limiting scaling relation σy∼ϕ-ϕc,∞, where ϕc,∞ is the critical volume fraction of the jamming transition at σ=0 in the thermodynamic limit. The finite size scaling implies a length ξ∼(ϕ-ϕc,∞)-ν with ν=0.81±0.05, which turns out to be a robust and universal length scale exhibited as well in the finite size scaling of multiple quantities measured without shear and independent of particle interaction. Moreover, comparison between our new approach and quasistatic shear reveals that quasistatic shear tends to explore low-energy states.

12.
Hellenic J Cardiol ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38460616

RESUMO

BACKGROUND: The safety and efficacy of a combined approach of catheter ablation (CA) and left atrial appendage occlusion (LAAO) compared to LAAO alone remain unknown. METHODS: Patients with atrial fibrillation (AF) at increased stroke risk who underwent LAAO were divided into either combined (CA and LAAO) procedures or LAAO alone group. Propensity score matching was utilized to balance baseline characteristics. The primary endpoint of the study was a composite of death, thromboembolic events, major bleeding, heart failure (HF) rehospitalization, and major periprocedural complications. RESULTS: A total of 707 AF patients who underwent LAAO were included. After 1:1 propensity score matching, 166 patients who underwent LAAO alone (n = 83) or the combined procedure (n = 83) were analyzed. Successful LAAO was achieved in all (100%) patients, with a low incidence of periprocedural complications in both groups (2.4% vs. 4.8%, LAAO vs. combined, p = 0.68). The incidence of peri-device leak post-LAAO was significantly higher in the combined group (25.3% vs. 43.4%, p = 0.01). After a median follow-up of 2 years, there were no significant differences in the rates of the primary composite endpoint between the two strategies (22.2% vs. 14.3%, HR: 1.24 [95% CI: 0.51-2.97], p = 0.63). However, the rate of HF rehospitalization was significantly lower in the combined group (19.6% vs. 3.6%, HR: 4.89 [95% CI: 1.50-15.97], p = 0.024). CONCLUSIONS: Combining CA and LAAO in a "one-stop" approach is safe and brings additional benefits in relieving symptoms of heart failure, although peri-device leak was more common compared to LAAO alone.

13.
Chem Commun (Camb) ; 60(33): 4479-4482, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38564258

RESUMO

We found that the N6 methyl group of N6-methyladenine is able to hinder the methylation of N6-methyladenine at the N1 position by DMS. Based on this, we have devised a novel method for detecting N6-methyladenine, which was successfully applied to identify specific m6A loci in 28S rRNA.


Assuntos
Metilação , RNA Ribossômico 28S
14.
ACS Nano ; 18(26): 16684-16691, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38885639

RESUMO

Recently, there has been significant interest in topological nodal-line semimetals due to their linear energy dispersion with one-dimensional nodal lines or loops. These materials exhibit fascinating physical properties, such as drumhead surface states and 3D anisotropic nodal-line structures. Similar to Weyl semimetals, type-II nodal-line semimetals have two crossing bands that are both electron-like or hole-like along a certain direction. However, the direct observation of type-II nodal-line Fermions has been challenging due to the lack of suitable material platforms and the low density of states. Here we present experimental evidence for the coexistence of both type-I and type-II nodal-line Fermions in ZrSiSe, which was obtained through magneto-optical and angle-resolved photoemission spectroscopy (ARPES) measurements. Our density functional theory calculations predict that the type-II nodal-line structure can be developed in the Z-R line of the first Brillouin zone based on the lattice constants of the grown single crystal. Indeed, ARPES measurements reveal the type-II nodal-line band structure. The extracted type-II Landau level transitions from magneto-optical measurements exhibit good agreement with the calculated type-II energy dispersion model based on the band structure. Our experimental results demonstrate that ZrSiSe possesses two types of nodal-line Fermions, distinguishing it from other ZrSiX (X = S, Te) materials and positioning it as an ideal platform for investigating type-II nodal-line semimetals.

15.
Nat Commun ; 15(1): 5651, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38969644

RESUMO

The bulk photovoltaic effect (BPVE) in non-centrosymmetric materials has attracted significant attention in recent years due to its potential to surpass the Shockley-Queisser limit. Although these materials are strictly constrained by symmetry, progress has been made in artificially reducing symmetry to stimulate BPVE in wider systems. However, the complexity of these techniques has hindered their practical implementation. In this study, we demonstrate a large intrinsic photocurrent response in centrosymmetric topological insulator Ag2Te, attributed to the surface photogalvanic effect (SPGE), which is induced by symmetry reduction of the surface. Through diverse spatially-resolved measurements on specially designed devices, we directly observe that SPGE in Ag2Te arises from the difference between two opposite photocurrent flows generated from the top and bottom surfaces. Acting as an efficient SPGE material, Ag2Te demonstrates robust performance across a wide spectral range from visible to mid-infrared, making it promising for applications in solar cells and mid-infrared detectors. More importantly, SPGE generated on low-symmetric surfaces can potentially be found in various systems, thereby inspiring a broader range of choices for photovoltaic materials.

16.
J Chem Phys ; 139(21): 214113, 2013 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-24320370

RESUMO

The Stokes-Einstein relation for the self-diffusion coefficient of a spherical particle suspended in an incompressible fluid is an asymptotic result in the limit of large Schmidt number, that is, when momentum diffuses much faster than the particle. When the Schmidt number is moderate, which happens in most particle methods for hydrodynamics, deviations from the Stokes-Einstein prediction are expected. We study these corrections computationally using a recently developed minimally resolved method for coupling particles to an incompressible fluctuating fluid in both two and three dimensions. We find that for moderate Schmidt numbers the diffusion coefficient is reduced relative to the Stokes-Einstein prediction by an amount inversely proportional to the Schmidt number in both two and three dimensions. We find, however, that the Einstein formula is obeyed at all Schmidt numbers, consistent with linear response theory. The mismatch arises because thermal fluctuations affect the drag coefficient for a particle due to the nonlinear nature of the fluid-particle coupling. The numerical data are in good agreement with an approximate self-consistent theory, which can be used to estimate finite-Schmidt number corrections in a variety of methods. Our results indicate that the corrections to the Stokes-Einstein formula come primarily from the fact that the particle itself diffuses together with the momentum. Our study separates effects coming from corrections to no-slip hydrodynamics from those of finite separation of time scales, allowing for a better understanding of widely observed deviations from the Stokes-Einstein prediction in particle methods such as molecular dynamics.

17.
Echocardiography ; 30(3): E64-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23186363

RESUMO

Perivalvular leaks are usually caused by suture interruption in prosthetic valves or infective endocarditis. Traumatic mitral annular dehiscence is a very uncommon event. We present a rare case of severe mitral regurgitation secondary to perivalvular abnormal communication in a 35-year-old man with a history of blunt chest trauma. He presented with symptoms of cough and chest tightness for 3 months. Preoperative two-dimensional and real time three-dimensional transesophageal echocardiography clearly showed the position and size of the perivalvular abnormal communication and the incident damage of the left ventricular wall. The patient finally underwent successful surgical repair.


Assuntos
Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/etiologia , Valva Mitral/anormalidades , Valva Mitral/lesões , Traumatismos Torácicos/complicações , Ferimentos não Penetrantes/complicações , Adulto , Humanos , Masculino , Valva Mitral/diagnóstico por imagem , Traumatismos Torácicos/diagnóstico por imagem , Ultrassonografia , Ferimentos não Penetrantes/diagnóstico por imagem
18.
Child Neuropsychol ; 29(3): 457-473, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35816416

RESUMO

Studies investigating the relationship between cognitive function and academic performance have recently shifted focus from differences in intelligence to executive function. To date, these studies have focused disproportionately on samples recruited from Western countries, despite evidence in support of cultural differences in the development of executive function. To address this gap, the present study investigated whether differences in two dimensions of executive function, inhibitory and attentional control, could predict academic performance in a sample of Chinese adolescents (n = 42). Participants reported on demographic details and completed both the Simon task and Attention Network Test. Data were analyzed using multiple linear regression controlling for gender, age, SES, English language proficiency, processing speed, and fluid intelligence. Results showed that one index of inhibitory control derived from non-cue trials on the Attention Network Test explained a significant amount of unique variance in academic performance. Our findings provide evidence that executive function, specifically inhibitory control, plays a significant role in academic performance.


Assuntos
Desempenho Acadêmico , População do Leste Asiático , Adolescente , Humanos , Função Executiva , Cognição , Idioma
19.
Talanta ; 257: 124387, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36841014

RESUMO

The design of nanozymes with high metal atom loading is of great significance to improve enzyme activity and is also the key to furthering the construction of highly sensitive colorimetric sensors. In this work, a colorimetric sensor for the quantitative analysis of tannic acid (TA) was developed based on two-dimensional carbon nanosheet carbon nitride (CN)-supported Cu single-atom nanozymes (Cu/CN). Cu/CN was synthesized by supramolecular preorganization and calcination, with an ultrathin nanosheet structure and a high density of Cu active sites, with a Cu loading of up to 14.3 wt%. Benefiting from the above characteristics, Cu/CN exhibits peroxidase-mimicking activity and excellent catalytic performance. Therefore, a colorimetric sensor was constructed for the fast and sensitive quantitative analysis of TA with good linearity in the range of 0.09-3.2 µM and a low detection limit of 30 nM. Furthermore, the sensor was successfully applied to the analysis of TA in tea samples of different varieties. This work sheds new light on the design of nanozymes with a high density of active sites and the analysis of TA in real environments.


Assuntos
Colorimetria , Nitrilas , Colorimetria/métodos , Nitrilas/química , Catálise , Peroxidases/química , Peróxido de Hidrogênio/análise , Carbono/química
20.
EuroIntervention ; 19(8): 695-702, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37594402

RESUMO

BACKGROUND: The current risk stratification schemes for stroke in patients with atrial fibrillation (AF) are insufficient for an accurate assessment of stroke risk. AIMS: This study evaluates the association between the mechanical function of the left atrial appendage (LAA), as assessed by angiography, and the risk of stroke. METHODS: We conducted a cross-sectional study to assess the mechanical function of the LAA by measuring the left atrial appendage ejection fraction (LAAEF) and grading the contrast retention (CR) using angiography. RESULTS: A total of 746 patients referred for a left atrial appendage occlusion (LAAO) procedure with (n=151; stroke group) or without (n=595; control group) a history of stroke were included in the analysis. LAAEF was significantly lower (14% [9-19] vs 20% [12-33]; p<0.001) and grade 3 CR was more common (66.9% vs 33.9%; p<0.001) in patients with a history of stroke. Multivariable analysis showed that CR was independently associated with stroke in patients with AF (grade 2 vs grade 1=7.29; 95% confidence interval [CI]: 2.84-21.65; p<0.001; grade 3 vs grade 1=16.45; 95% CI: 6.16-51.02; p<0.001). The receiver operating characteristics curve demonstrated that CR identified patients with stroke more accurately than the CHA2D-VASc score (C-statistic 0.712 vs 0.512; p<0.001), and the combination of CR and the CHA2DS2-VASc score provided the best performance (C-statistic 0.871 vs 0.829 [CHA2DS2-VASc score alone]; p=0.048) Conclusions: Impaired mechanical function of the LAA, indicated by a low LAAEF and CR, is associated with a history of stroke in patients with AF. Assessment of CR using LAA angiography helps improve the stratification scheme for stroke risk prediction.


Assuntos
Apêndice Atrial , Fibrilação Atrial , Acidente Vascular Cerebral , Humanos , Fibrilação Atrial/complicações , Apêndice Atrial/diagnóstico por imagem , Fatores de Risco , Estudos Transversais , Ecocardiografia Transesofagiana/métodos , Acidente Vascular Cerebral/complicações , Angiografia
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