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1.
Cardiovasc Diabetol ; 23(1): 148, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685007

RESUMO

BACKGROUND: Glycemic control, as measured by glycosylated hemoglobin (HbA1c), is an important biomarker to evaluate diabetes severity and is believed to be associated with heart failure development. Type 2 diabetes mellitus (T2DM) and heart failure with reduced ejection fraction (HFrEF) commonly coexist, and the combination of these two diseases indicates a considerably poorer outcome than either disease alone. Therefore, glycemic control should be carefully managed. The present study aimed to explore the association between glycemic control and clinical outcomes, and to determine the optimal glycemic target in this specific population. METHODS: A total of 262 patients who underwent cardiac MRI were included and were split by HbA1c levels [HbA1c < 6.5% (intensive control), HbA1c 6.5-7.5% (modest control), and HbA1c > 7.5% (poor control)]. The biventricular volume and function, as well as left ventricular (LV) systolic strains in patients in different HbA1c categories, were measured and compared. The primary and secondary outcomes were recorded. The association of different HbA1c levels with adverse outcomes was assessed. RESULTS: Despite similar biventricular ejection fractions, both patients with intensive and poor glycemic control exhibited prominent deterioration of LV systolic strain in the longitudinal component (P = 0.004). After a median follow-up of 35.0 months, 55 patients (21.0%) experienced at least one confirmed endpoint event. Cox multivariable analysis indicated that both patients in the lowest and highest HbA1c categories exhibited a more than 2-fold increase in the risk for primary outcomes [HbA1c < 6.5%: hazard ratio (HR) = 2.42, 95% confidence interval (CI) = 1.07-5.45; P = 0.033; HbA1c > 7.5%: HR = 2.24, 95% CI = 1.01-4.99; P = 0.038] and secondary outcomes (HbA1c < 6.5%: HR = 2.84, 95% CI = 1.16-6.96; P = 0.022; HbA1c > 7.5%: HR = 2.65, 95% CI = 1.08-6.50; P = 0.038) compared with those in the middle HbA1c category. CONCLUSIONS: We showed a U-shaped association of glycemic control with clinical outcomes in patients with T2DM and HFrEF, with the lowest risk of adverse outcomes among patients with modest glycemic control. HbA1c between 6.5% and 7.5% may be served as the optimal hypoglycemic target in this specific population.


Assuntos
Biomarcadores , Glicemia , Diabetes Mellitus Tipo 2 , Hemoglobinas Glicadas , Controle Glicêmico , Insuficiência Cardíaca , Valor Preditivo dos Testes , Volume Sistólico , Função Ventricular Esquerda , Remodelação Ventricular , Humanos , Masculino , Feminino , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/diagnóstico por imagem , Hemoglobinas Glicadas/metabolismo , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatologia , Idoso , Glicemia/metabolismo , Biomarcadores/sangue , Fatores de Risco , Estudos Retrospectivos , Imagem Cinética por Ressonância Magnética , Fatores de Tempo , Hipoglicemiantes/uso terapêutico , Medição de Risco , Prognóstico
2.
Cardiovasc Diabetol ; 23(1): 217, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38915040

RESUMO

BACKGROUND: Diabetic peripheral neuropathy (DPN) is the most prevalent complication of diabetes, and has been demonstrated to be independently associated with cardiovascular events and mortality. This aim of this study was to investigate the subclinical left ventricular (LV) myocardial dysfunction in type 2 diabetes mellitus (T2DM) patients with and without DPN. METHODS: One hundred and thirty T2DM patients without DPN, 61 patients with DPN and 65 age and sex-matched controls who underwent cardiovascular magnetic resonance (CMR) imaging were included, all subjects had no symptoms of heart failure and LV ejection fraction ≥ 50%. LV myocardial non-infarct late gadolinium enhancement (LGE) was determined. LV global strains, including radial, circumferential and longitudinal peak strain (PS) and peak systolic and diastolic strain rates (PSSR and PDSR, respectively), were evaluated using CMR feature tracking and compared among the three groups. Multivariable linear regression analyses were performed to determine the independent factors of reduced LV global myocardial strains in T2DM patients. RESULTS: The prevalence of non-infarct LGE was higher in patients with DPN than those without DPN (37.7% vs. 19.2%, p = 0.008). The LV radial and longitudinal PS (radial: 36.60 ± 7.24% vs. 33.57 ± 7.30% vs. 30.72 ± 8.68%; longitudinal: - 15.03 ± 2.52% vs. - 13.39 ± 2.48% vs. - 11.89 ± 3.02%), as well as longitudinal PDSR [0.89 (0.76, 1.05) 1/s vs. 0.80 (0.71, 0.93) 1/s vs. 0.77 (0.63, 0.87) 1/s] were decreased significantly from controls through T2DM patients without DPN to patients with DPN (all p < 0.001). LV radial and circumferential PDSR, as well as circumferential PS were reduced in both patient groups (all p < 0.05), but were not different between the two groups (all p > 0.05). Radial and longitudinal PSSR were decreased in patients with DPN (p = 0.006 and 0.003, respectively) but preserved in those without DPN (all p > 0.05). Multivariable linear regression analyses adjusting for confounders demonstrated that DPN was independently associated with LV radial and longitudinal PS (ß = - 3.025 and 1.187, p = 0.014 and 0.003, respectively) and PDSR (ß = 0.283 and - 0.086, p = 0.016 and 0.001, respectively), as well as radial PSSR (ß = - 0.266, p = 0.007). CONCLUSIONS: There was more severe subclinical LV dysfunction in T2DM patients complicated with DPN than those without DPN, suggesting further prospective study with more active intervention in this cohort of patients.


Assuntos
Doenças Assintomáticas , Diabetes Mellitus Tipo 2 , Cardiomiopatias Diabéticas , Neuropatias Diabéticas , Imagem Cinética por Ressonância Magnética , Valor Preditivo dos Testes , Disfunção Ventricular Esquerda , Função Ventricular Esquerda , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Neuropatias Diabéticas/fisiopatologia , Neuropatias Diabéticas/diagnóstico por imagem , Neuropatias Diabéticas/etiologia , Neuropatias Diabéticas/diagnóstico , Neuropatias Diabéticas/epidemiologia , Idoso , Estudos de Casos e Controles , Cardiomiopatias Diabéticas/fisiopatologia , Cardiomiopatias Diabéticas/diagnóstico por imagem , Cardiomiopatias Diabéticas/etiologia , Fatores de Risco , Prevalência , Estudos Transversais , Volume Sistólico , Contração Miocárdica
3.
Cardiovasc Diabetol ; 23(1): 28, 2024 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-38218882

RESUMO

BACKGROUND: Sarcopenia is frequently found in patients with heart failure with reduced ejection fraction (HFrEF) and is associated with reduced exercise capacity, poor quality of life and adverse outcomes. Recent evidence suggests that axial thoracic skeletal muscle size could be used as a surrogate to assess sarcopenia in HFrEF. Since diabetes mellitus (DM) is one of the most common comorbidities with HFrEF, we aimed to explore the potential association of axial thoracic skeletal muscle size with left ventricular (LV) remodeling and determine its prognostic significance in this condition. METHODS: A total of 243 diabetes patients with HFrEF were included in this study. Bilateral axial thoracic skeletal muscle size was obtained using cardiac MRI. Patients were stratified by the tertiles of axial thoracic skeletal muscle index (SMI). LV structural and functional indices, as well as amino-terminal pro-B-type natriuretic peptide (NT-proBNP), were measured. The determinants of elevated NT-proBNP were assessed using linear regression analysis. The associations between thoracic SMI and clinical outcomes were assessed using a multivariable Cox proportional hazards model. RESULTS: Patients in the lowest tertile of thoracic SMI displayed a deterioration in LV systolic strain in three components, together with an increase in LV mass and a heavier burden of myocardial fibrosis (all P < 0.05). Moreover, thoracic SMI (ß = -0.25; P < 0.001), rather than body mass index (ß = -0.04; P = 0.55), was independently associated with the level of NT-proBNP. The median follow-up duration was 33.6 months (IQR, 20.4-52.8 months). Patients with adverse outcomes showed a lower thoracic SMI (40.1 [34.3, 47.9] cm2/m2 vs. 45.3 [37.3, 55.0] cm2/m2; P < 0.05) but a similar BMI (P = 0.76) compared with those without adverse outcomes. A higher thoracic SMI indicated a lower risk of adverse outcomes (hazard ratio: 0.96; 95% confidence interval: 0.92-0.99; P = 0.01). CONCLUSIONS: With respect to diabetes patients with HFrEF, thoracic SMI is a novel alternative for evaluating muscle wasting in sarcopenia that can be obtained by a readily available routine cardiac MRI protocol. A reduction in thoracic skeletal muscle size predicts poor outcomes in the context of DM with HFrEF.


Assuntos
Diabetes Mellitus , Insuficiência Cardíaca , Sarcopenia , Disfunção Ventricular Esquerda , Humanos , Insuficiência Cardíaca/diagnóstico por imagem , Sarcopenia/diagnóstico por imagem , Sarcopenia/epidemiologia , Qualidade de Vida , Biomarcadores , Volume Sistólico/fisiologia , Peptídeo Natriurético Encefálico , Imageamento por Ressonância Magnética , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Fragmentos de Peptídeos , Músculo Esquelético/diagnóstico por imagem , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia
4.
Cardiovasc Diabetol ; 23(1): 90, 2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448890

RESUMO

BACKGROUND: Atrial fibrillation (AF) has been linked to an increased risk of cardiovascular death, overall mortality and heart failure in patients with type 2 diabetes mellitus (T2DM). The present study investigated the additive effects of paroxysmal AF on left ventricular (LV) function and deformation in T2DM patients with or without AF using the cardiovascular magnetic resonance feature tracking (CMR-FT) technique. METHODS: The present study encompassed 225 T2DM patients differentiated by the presence or absence of paroxysmal AF [T2DM(AF+) and T2DM(AF-), respectively], along with 75 age and sex matched controls, all of whom underwent CMR examination. LV function and global strains, including radial, circumferential and longitudinal peak strain (PS), as well as peak systolic and diastolic strain rates (PSSR and PDSR, respectively), were measured and compared among the groups. Multivariable linear regression analysis was used to examine the factors associated with LV global strains in patients with T2DM. RESULTS: The T2DM(AF+) group was the oldest, had the highest LV end­systolic volume index, lowest LV ejection fraction and estimated glomerular filtration rate compared to the control and T2DM(AF-) groups, and presented a shorter diabetes duration and lower HbA1c than the T2DM(AF-) group. LV PS-radial, PS-longitudinal and PDSR-radial declined successively from controls through the T2DM(AF-) group to the T2DM(AF+) group (all p < 0.001). Compared to the control group, LV PS-circumferential, PSSR-radial and PDSR-circumferential were decreased in the T2DM(AF+) group (all p < 0.001) but preserved in the T2DM(AF-) group. Among all clinical indices, AF was independently associated with worsening LV PS-longitudinal (ß = 2.218, p < 0.001), PS-circumferential (ß = 3.948, p < 0.001), PS-radial (ß = - 8.40, p < 0.001), PSSR-radial and -circumferential (ß = - 0.345 and 0.101, p = 0.002 and 0.014, respectively), PDSR-radial and -circumferential (ß = 0.359 and - 0.14, p = 0.022 and 0.003, respectively). CONCLUSIONS: In patients with T2DM, the presence of paroxysmal AF further exacerbates LV function and deformation. Proactive prevention, regular detection and early intervention of AF could potentially benefit T2DM patients.


Assuntos
Fibrilação Atrial , Sistema Cardiovascular , Diabetes Mellitus Tipo 2 , Humanos , Fibrilação Atrial/diagnóstico , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Função Ventricular Esquerda , Espectroscopia de Ressonância Magnética
5.
J Magn Reson Imaging ; 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38703135

RESUMO

BACKGROUND: Hypertension (HTN) and type 2 diabetes mellitus (T2DM) are both associated with left ventricular (LV) and left atrial (LA) structural and functional abnormalities; however, the relationship between the left atrium and ventricle in this population is unclear. PURPOSE: To identify differences between hypertensive patients with and without T2DM as the basis for further investigation the atrioventricular coupling relationship. STUDY TYPE: Cross-sectional, retrospective study. POPULATION: 89 hypertensive patients without T2DM [HTN (T2DM-)] (age: 58.4 +/- 11.9 years, 48 male), 62 hypertensive patients with T2DM [HTN (T2DM+)] (age: 58.5 +/- 9.1 years, 32 male) and 70 matched controls (age: 55.0 +/- 9.6 years, 37 male). FIELD STRENGTH/SEQUENCE: 2D balanced steady-state free precession cine sequence at 3.0 T. ASSESSMENT: LA reservoir, conduit, and booster strain (εs, εe, and εa) and strain rate (SRs, SRe, and SRa), LV radial, circumferential and longitudinal peak strain (PS) and peak systolic strain rate and peak diastolic strain rate (PSSR and PDSR) were derived from LA and LV cine images and compared between groups. STATISTICAL TESTS: Chi-square or Fisher's exact test, one-way analysis of variance, analysis of covariance, Pearson's correlation, multivariable linear regression analysis, and intraclass correlation coefficient. A P value <0.05 was considered significant. RESULTS: Compared with controls, εs, εe, SRe and PS-longitudinal, PDSR-radial, and PDSR-longitudinal were significantly lower in HTN (T2DM-) group, and they were even lower in HTN (T2DM+) group than in both controls and HTN (T2DM-) group. SRs, εa, SRa, as well as PS-radial, PS-circumferential, PSSR-radial, and PSSR-circumferential were significantly lower in HTN (T2DM+) compared with controls. Multivariable regression analyses demonstrated that: T2DM and PS-circumferential and PS-longitudinal (ß = -4.026, -0.486, and -0.670, respectively) were significantly associated with εs; T2DM and PDSR-radial and PDSR-circumferential were significantly associated with εe (ß = -3.406, -3.352, and -6.290, respectively); T2DM and PDSR-radial were significantly associated with SRe (ß = 0.371 and 0.270, respectively); T2DM and PDSR-longitudinal were significantly associated with εa (ß = -1.831 and 5.215, respectively); and PDSR-longitudinal was significantly associated with SRa (ß = 1.07). DATA CONCLUSION: In hypertensive patients, there was severer LA dysfunction in those with coexisting T2DM, which may be associated with more severe LV dysfunction and suggests adverse atrioventricular coupling. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 3.

6.
Cardiovasc Diabetol ; 22(1): 93, 2023 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-37085847

RESUMO

BACKGROUND: To investigate the difference of right ventricular (RV) structural and functional alteration in patients with diabetes mellitus (DM) with preserved left ventricular ejection fraction (LVEF), and the ventricular interdependence in these patients, using cardiac MR (CMR) feature tracking. METHODS: From December 2016 to February 2022, 148 clinically diagnosed patients with DM who underwent cardiac MR (CMR) in our hospital were consecutively recruited. Fifty-four healthy individuals were included as normal controls. Biventricular strains, including left/right ventricular global longitudinal strain (LV-/RVGLS), left/right ventricular global circumferential strain (LV-/RVGCS), left/right ventricular global radial strain (LV-/RVGRS) were evaluated, and compared between patients with DM and healthy controls. Multiple linear regression and mediation analyses were used to evaluate DM's direct and indirect effects on RV strains. RESULTS: No differences were found in age (56.98 ± 10.98 vs. 57.37 ± 8.41, p = 0.985), sex (53.4% vs. 48.1%, p = 0.715), and body surface area (BSA) (1.70 ± 0.21 vs. 1.69 ± 0.17, p = 0.472) between DM and normal controls. Patients with DM had decreased RVGLS (- 21.86 ± 4.14 vs. - 24.49 ± 4.47, p = 0.001), RVGCS (- 13.16 ± 3.86 vs. - 14.92 ± 3.08, p = 0.011), and no decrease was found in RVGRS (22.62 ± 8.11 vs. 23.15 ± 9.05, p = 0.743) in patients with DM compared with normal controls. The difference in RVGLS between normal controls and patients with DM was totally mediated by LVGLS (indirect effecting: 0.655, bootstrapped 95%CI 0.138-0.265). The difference in RVGCS between normal controls and DM was partly mediated by the LVGLS (indirect effecting: 0.336, bootstrapped 95%CI 0.002-0.820) and LVGCS (indirect effecting: 0.368, bootstrapped 95%CI 0.028-0.855). CONCLUSIONS: In the patients with DM and preserved LVEF, the difference in RVGLS between DM and normal controls was totally mediated by LVGLS. Although there were partly mediating effects of LVGLS and LVGCS, the decrease in RVGCS might be directly affected by the DM.


Assuntos
Diabetes Mellitus , Disfunção Ventricular Esquerda , Disfunção Ventricular Direita , Humanos , Função Ventricular Esquerda , Volume Sistólico , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/etiologia , Ventrículos do Coração/diagnóstico por imagem , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia
7.
Cardiovasc Diabetol ; 22(1): 256, 2023 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-37735418

RESUMO

BACKGROUND: Diabetic peripheral neuropathy (DPN) has been shown to be independently associated with cardiovascular events and mortality. This study aimed to evaluate changes in left ventricular (LV) microvascular perfusion and myocardial deformation in type 2 diabetes mellitus (T2DM) patients with and without DPN, as well as to investigate the association between myocardial perfusion and LV deformation. METHODS: Between October 2015 and July 2022, one hundred and twenty-three T2DM patients without DPN, fifty-four patients with DPN and sixty age­ and sex­matched controls who underwent cardiovascular magnetic resonance imaging were retrospectively analyzed. LV myocardial perfusion parameters at rest, including upslope, time to maximum signal intensity (TTM), max signal intensity (max SI), and myocardial strains, including global radial, circumferential and longitudinal strain (GRS, GCS and GLS, respectively), were calculated and compared among the groups with One­way analysis of variance. Univariable and multivariable linear regression analyses were performed to explore the independent factors influencing LV myocardial perfusion indices and LV strains in diabetes. RESULTS: The LV GLS, upslope and max SI were significantly deteriorated from controls, through patients without DPN, to patients with DPN (all P < 0.001). Compared with controls, TTM was increased and LV GRS and GCS were decreased in both patient groups (all P < 0.05). Multivariable regression analyses considering covariates showed that DPN was independently associated with reduced upslope, max SI and LV GLS (ß = - 0.360, - 2.503 and 1.113, p = 0.021, 0.031 and 0.010, respectively). When the perfusion indices upslope and max SI were included in the multivariable analysis for LV deformation, DPN and upslope (ß = 1.057 and - 0.870, p = 0.020 and 0.018, respectively) were significantly associated with LV GLS. CONCLUSION: In patients with T2DM, there was more severe LV microvascular and myocardial dysfunction in patients with complicated DPN, and deteriorated subclinical LV systolic dysfunction was associated with impaired myocardial circulation.


Assuntos
Diabetes Mellitus Tipo 2 , Doenças do Sistema Nervoso Periférico , Humanos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Estudos Retrospectivos , Coração , Imageamento por Ressonância Magnética
8.
Cardiovasc Diabetol ; 22(1): 295, 2023 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-37904206

RESUMO

PURPOSE: The study was designed to assess the effect of co-occurrence of diabetes mellitus (DM) and hypertension on the deterioration of left atrioventricular coupling index (LACI) and left atrial (LA) function in comparison to individuals suffering from DM only. METHODS: From December 2015 to June 2022, we consecutively recruited patients with clinically diagnosed DM who underwent cardiac magnetic resonance (CMR) at our hospital. The study comprised a total of 176 patients with DM, who were divided into two groups based on their blood pressure status: 103 with hypertension (DM + HP) and 73 without hypertension (DM-HP). LA reservoir function (reservoir strain (εs), total LA ejection fraction (LAEF)), conduit function (conduit strain (εe), passive LAEF), booster-pump function (booster strain (εa) and active LAEF), LA volume index (LAVI), LV global longitudinal strain (LVGLS), and LACI were evaluated and compared between the two groups. RESULTS: After adjusting for age, sex, body surface area (BSA), and history of current smoking, total LAEF (61.16 ± 14.04 vs. 56.05 ± 12.72, p = 0.013) and active LAEF (43.98 ± 14.33 vs. 38.72 ± 13.51, p = 0.017) were lower, while passive LAEF (33.22 ± 14.11 vs. 31.28 ± 15.01, p = 0.807) remained unchanged in the DM + HP group compared to the DM-HP group. The DM + HP group had decreased εs (41.27 ± 18.89 vs. 33.41 ± 13.94, p = 0.006), εe (23.69 ± 12.96 vs. 18.90 ± 9.90, p = 0.037), εa (17.83 ± 8.09 vs. 14.93 ± 6.63, p = 0.019), and increased LACI (17.40±10.28 vs. 22.72±15.01, p = 0.049) when compared to the DM-HP group. In patients with DM, multivariate analysis revealed significant independent associations between LV GLS and εs (ß=-1.286, p < 0.001), εe (ß=-0.919, p < 0.001), and εa (ß=-0.324, p = 0.036). However, there was no significant association observed between LV GLS and LACI (ß=-0.003, p = 0.075). Additionally, hypertension was found to independently contribute to decreased εa (ß=-2.508, p = 0.027) and increased LACI in individuals with DM (ß = 0.05, p = 0.011). CONCLUSIONS: In DM patients, LV GLS showed a significant association with LA phasic strain. Hypertension was found to exacerbate the decline in LA booster strain and increase LACI in DM patients, indicating potential atrioventricular coupling index alterations.


Assuntos
Diabetes Mellitus , Hipertensão , Humanos , Função do Átrio Esquerdo , Átrios do Coração/diagnóstico por imagem , Hipertensão/complicações , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/patologia , Espectroscopia de Ressonância Magnética
9.
J Magn Reson Imaging ; 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37966904

RESUMO

BACKGROUND: Understanding the impact of aortic regurgitation (AR) on hypertensive patients' hearts is important. PURPOSE: To assess left ventricular (LV) strain and structure in hypertensive patients and investigate the relationship with AR severity. STUDY TYPE: Retrospective. POPULATION: 263 hypertensive patients (99 with AR) and 62 controls, with cardiac MRI data. FIELD STRENGTH/SEQUENCE: Balanced steady-state free precession (bSSFP) sequence at 3.0T. ASSESSMENT: AR was classified as mild, moderate, or severe based on echocardiographic findings. LV geometry was classified as normal, concentric remodeling, eccentric hypertrophy, or concentric hypertrophy based on MRI assessment of LV mass/volume ratio and LV Mass index (LVMI). LV global radial peak strain (GRPS), global circumferential peak strain (GCPS), and global longitudinal peak strain (GLPS) were obtained by post-processing bSSFP cine datasets using commercial software. STATISTICAL TESTS: ANOVA, Kruskal-Wallis test, Spearman's correlation coefficients (r), chi-square test, and multivariable linear regression analysis. A P value <0.05 was considered statistically significant. RESULTS: Hypertensive patients with AR had significantly lower LV myocardial strain and higher LVMI than the group without AR (GRPS 26.25 ± 12.23 vs. 34.53 ± 9.85, GCPS -17.4 ± 5.84 vs. -20.57 ± 3.57, GLPS -9.86 ± 4.08 vs. -12.95 ± 2.94, LVMI 90.56 ± 38.56 vs.58.84 ± 17.55). Of the 99 patients with AR, 56 had mild AR, 26 had moderate AR and 17 had severe AR. The degree of AR was significantly negatively correlated to the absolute values of LV GRPS, GCPS and GLPS (r = -0.284 - -0.416). LV eccentric hypertrophy increased significantly with AR severity (no AR 21.3%, mild AR 42.9%, moderate AR 73.1%, severe AR 82.4%). In multivariable analysis, the degree of AR was an independent factor affecting LV global strain and LVMI even after considering confounding factors (ß values for global myocardial strain were -0.431 to -0.484, for LVMI was 0.646). DATA CONCLUSION: Increasing AR severity leads to decreased cardiac function and worse ventricular geometric phenotypes in hypertensive patients. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 3.

10.
J Magn Reson Imaging ; 2023 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-37864419

RESUMO

BACKGROUND: Pulmonary hypertension (PH) results in right ventricular (RV) dysfunction, subsequently leading to left ventricular (LV) impairment. The mechanism underlying ventricular interdependence is largely uninvestigated. PURPOSE: To explore the biventricular dysfunction and the ventricular interdependence in PH patients. STUDY TYPE: Retrospective. POPULATION: One hundred and seven PH patients (mean pulmonary artery pressure >20 mmHg) and 72 age- and sex-matched controls with cardiac magnetic resonance imaging (MRI) studies. FIELD STRENGTH/SEQUENCE: 3.0 T/balanced steady-state free precession sequence. ASSESSMENT: LV and RV ejection fractions (EF) and RV and LV radial, circumferential, and longitudinal strains were assessed using commercial software. Strains were compared between controls, PH patients with preserved RVEF (RVEF ≥40%, N = 48), and PH patients with reduced RVEF (RVEF <40%, N = 59). STATISTICAL TESTS: Chi-squared tests or Fisher's exact test, t tests or Mann-Whitney U test, one-way ANOVA with Bonferroni's post hoc correction or Kruskal-Wallis test, Pearson or Spearman correlation, and multivariable linear regression analysis. A two-tailed P < 0.05 was deemed statistically significant. RESULTS: RV strain decreased sequentially from controls, through PH with preserved RVEF, to PH with reduced RVEF. PH patients with reduced RVEF had significantly lower LV strain, especially septal strain, and LV peak diastolic strain rate compared with both controls and PH patients with preserved RVEF. Multivariable analyses showed that RVEF was independently correlated with LV strain; furthermore, independent of RVEF, RV strain was significantly correlated with LV strain (LVGRS: ß = 0.416; LVGCS: ß = -0.371; LVGLS: ß = 0.283). DATA CONCLUSION: Subclinical impairment of RV function was found in PH with preserved RVEF. LV strain was impaired when RV was dysfunctional, which was associated with worsening RV strain. Therefore, while focusing on improving RV function, LV dysfunction in PH patients should also be monitored and treated early in order to slow the progression of the disease. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 3.

11.
Heart Fail Rev ; 27(5): 1899-1909, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35064397

RESUMO

Myocardial fibrosis predisposes the development of main adverse cardiovascular events (MACEs) in various cardiac disorders. Native T1 derived from cardiac magnetic resonance allows the quantitative assessment of myocardial fibrosis without the use of contrast media. However, the prognostic value of native T1 in risk stratification remains uncertain. We searched MEDLINE®, Embase, and the Cochrane Library for cohort studies up to July 31, 2021, that reported prognostic data for native T1 in various cardiac disorders; the studies enrolling patients with myocardial iron or amyloid deposition, edema, and inflammation were excluded. A random effects meta-analysis was conducted. Heterogeneity was assessed using I2 statistic. Nineteen studies with 5,380 patients were included in this meta-analysis. Patients with MACEs had higher native T1 than those without [weighted mean difference: 27.35 (15.55-39.16), I2 = 23.2%]. The increase of native T1 per 1 ms [pooled adjusted hazard ratio (HR): 1.02 (1.00-1.03), I2 = 41.8%] and per ≥ 10 ms [pooled adjusted HR: 1.11 (1.07-1.16), I2 = 28.6%] was both associated with the development of MACEs; the categorical variable derived from native T1 also has the predicative value for MACEs [pooled adjusted HR: 5.97 (3.69-9.68), I2 = 0.0%].Myocardial native T1 potentially serves as a prognostic biomarker in patients with various cardiac disorders. Different variable definitions of native T1 have different positively predictive value for outcome; the categorical variable derived from native T1 may be more helpful in identifying high-risk patients.


Assuntos
Cardiomiopatias , Doenças Cardiovasculares , Cardiomiopatias/patologia , Meios de Contraste , Fibrose , Humanos , Imagem Cinética por Ressonância Magnética , Miocárdio/patologia , Valor Preditivo dos Testes , Prognóstico
12.
Cardiovasc Diabetol ; 21(1): 100, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35681217

RESUMO

BACKGROUND: Functional mitral regurgitation (FMR) in type 2 diabetes mellitus (T2DM) patients induced by left ventricular (LV) enlargement and mitral valve abnormality may aggravated the impairment in left atrial (LA) compliance. Thus, this study aimed to depict how FMR and LV dysfunction affect LA compliance in T2DM patients with FMR. MATERIALS AND METHODS: A total of 148 patients with T2DM and 49 age- and sex-matched normal controls underwent cardiac magnetic resonance examination. LA longitudinal strain and LA and LV functional indices were compared among controls and different T2DM patients. The multivariate analysis was used to identify the independent indicators of LA longitudinal strain. RESULTS: T2DM Patients without FMR had a lower total LA empty fraction (LAEF) compared with the controls (all P < 0.05). T2DM patients with mild and moderate FMR showed increased LA volume (LAV) and LV volume while decreased LAEF, LA strain, and LV ejection fraction (P < 0.05). T2DM patients with severe FMR showed markedly increased LAV and LV volume while decreased LAEF, LA strain, and LVEF (P < 0.05). In T2DM patients with FMR, reservoir strain (εs) was independently correlated with LV end-diastolic volume (LVEDV) (ß = - 0.334) and regurgitation degree (ß = - 0.256). The passive strain (εe) was independently correlated with regurgitation degree (ß = - 0.297), whereas the active strain (εa) was independently correlated with LVESV (ß = - 0.352) and glycated haemoglobin (ß = - 0.279). CONCLUSION: FMR may aggravate LA and LV dysfunction in T2DM patients. Regurgitation degree was an independent determinant of the εs and the εe, LVEDV was an independent determinant of the εs, and LVESV was an independent determinant of the εa in T2DM patients with FMR.


Assuntos
Diabetes Mellitus Tipo 2 , Insuficiência da Valva Mitral , Disfunção Ventricular Esquerda , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Humanos , Hipertrofia Ventricular Esquerda , Imageamento por Ressonância Magnética , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/etiologia , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Função Ventricular Esquerda
13.
Cardiovasc Diabetol ; 21(1): 69, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35524215

RESUMO

BACKGROUND: Heart failure with reduced ejection fraction (HFrEF) is a major health burden worldwide with high morbidity and mortality. Comorbidities of HFrEF complicate treatment and lead to poor prognosis, among which hypertension (HTN) and diabetes mellitus (DM) are common and frequently cooccur. DM was found to have additive effects on cardiac function and structure in hypertensive patients, while its effects on the HFrEF cohort in the context of HTN remain unclear. METHODS: A total of 171 patients with HFrEF were enrolled in our study, consisting of 51 HFrEF controls, 72 hypertensive HFrEF patients (HTN-HFrEF [DM-]) and 48 hypertensive HFrEF patients with comorbid DM (HTN-HFrEF [DM+]). Cardiac MRI-derived left ventricular (LV) strains, including global radial (GRPS), circumferential (GCPS) and longitudinal (GLPS) peak strain, and remodeling parameters were measured and compared among groups. The determinants of impaired LV function and LV remodeling in HFrEF patients were investigated by multivariable linear regression analyses. RESULTS: Despite a similar LV ejection fraction, patients in the HTN-HFrEF (DM+) and HTN-HFrEF (DM-) groups showed a higher LV mass index and LV remodeling index than those in the HFrEF control group (all p < 0.05). Compared with the HTN-HFrEF (DM-) and HFrEF control groups, the HTN-HFrEF (DM+) group exhibited the most severe GLPS impairment (p < 0.001). After adjustment for covariates in HFrEF patients, DM was found to be an independent determinant of impaired LV strains in all three directions (GRPS [ß = - 0.189; p = 0.011], GCPS [ß = 0.217; p = 0.005], GLPS [ß = 0.237; p = 0.002]). HTN was associated with impaired GLPS (ß = 0.185; p = 0.016) only. However, HTN rather than DM was associated with LV remodeling in HFrEF patients in the multivariable regression analysis (p < 0.05). CONCLUSIONS: DM aggravated LV longitudinal dysfunction in hypertensive HFrEF patients without further changes in LV remodeling, indicating that HFrEF patients with comorbid HTN and DM may have a hidden high-risk phenotype of heart failure that requires more advanced and personalized management.


Assuntos
Diabetes Mellitus , Insuficiência Cardíaca , Hipertensão , Disfunção Ventricular Esquerda , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/epidemiologia , Humanos , Hipertensão/complicações , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Imageamento por Ressonância Magnética , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/epidemiologia , Função Ventricular Esquerda , Remodelação Ventricular
14.
Cardiovasc Diabetol ; 21(1): 238, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36352469

RESUMO

BACKGROUND: Previous studies reported that there was right ventricular (RV) systolic dysfunction in patients with hypertension. The aim of this study was to evaluate the impact of type 2 diabetes mellitus (T2DM) on RV systolic dysfunction and interventricular interactions using cardiac magnetic resonance feature tracking (CMR-FT) in patients with essential hypertension. METHODS AND METHODS: Eighty-five hypertensive patients without T2DM [HTN(T2DM -)], 58 patients with T2DM [HTN(T2DM +)] and 49 normal controls were included in this study. The biventricular global radial, circumferential and longitudinal peak strains (GRS, GCS, GLS, respectively) and RV regional strains at the basal-, mid- and apical-cavity, were calculated with CMR-FT and compared among controls and different patient groups. Backward stepwise multivariable linear regression analyses were used to determine the effects of T2DM and left ventricular (LV) strains on RV strains. RESULTS: The biventricular GLS and RV apical longitudinal strain deteriorated significantly from controls, through HTN(T2DM-), to HTN(T2DM +) groups. RV middle longitudinal strain in patient groups were significantly reduced, and LV GRS and GCS and RV basal longitudinal strain were decreased in HTN(T2DM +) but preserved in HTN(T2DM-) group. Multivariable regression analyses adjusted for covariates demonstrated that T2DM was independently associated with LV strains (LV GRS: ß = - 4.278, p = 0.004, model R2 = 0.285; GCS: ß = 1.498, p = 0.006, model R2 = 0.363; GLS: ß = 1.133, p = 0.007, model R2 = 0.372) and RV GLS (ß = 1.454, p = 0.003, model R2 = 0.142) in hypertension. When T2DM and LV GLS were included in the multiple regression analysis, both T2DM and LV GLS (ß = 0.977 and 0.362, p = 0.039 and < 0.001, model R2 = 0.224) were independently associated with RV GLS. CONCLUSIONS: T2DM exacerbates RV systolic dysfunction in patients with hypertension, which may be associated with superimposed LV dysfunction by coexisting T2DM and suggests adverse interventricular interactions.


Assuntos
Cardiomiopatias , Diabetes Mellitus Tipo 2 , Hipertensão , Disfunção Ventricular Esquerda , Disfunção Ventricular Direita , Humanos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Hipertensão Essencial/complicações , Hipertensão Essencial/diagnóstico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Hipertensão/complicações , Hipertensão/diagnóstico , Função Ventricular Esquerda , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/etiologia , Imagem Cinética por Ressonância Magnética/métodos
15.
J Magn Reson Imaging ; 53(6): 1710-1720, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33470038

RESUMO

Left ventricular (LV) myocardial strain impairment has been demonstrated in hypertension despite normal LV ejection fraction (LVEF); however, limited data exist on any difference in results between genders. The aim of this study was to investigate the impact of gender on LV deformation in patients with essential hypertension. This was a cross-sectional study, in which 94 patients (47 men and 47 women) with essential hypertension and 62 age- and gender-matched controls (31 men and 31 women) were enrolled. A 3.0 T/two-dimensional balanced steady-state free precession cine, late gadolinium enhancement was used. The LV endocardial and epicardial contours were drawn by radiologists, then LV volumes, mass, function, and myocardial strain, including peak global radial (GRS), circumferential (GCS), and longitudinal strain (GLS) were automatically calculated. Chi-square test, Student's t-test, general linear model analysis, univariate linear regression analysis, stepwise multivariate linear regression analysis, and intraclass correlation coefficient analysis were performed. Women had significantly higher magnitudes of LV GRS, GCS, and GLS than men in both patients and controls (all p < 0.05). In the overall patients, LV GLS was significantly reduced compared with controls (p < 0.05), while GRS and GCS were preserved (p = 0.092 and 0.27, respectively). Compared with their counterpart controls, LV GRS, GCS, and GLS (all p < 0.05) were significantly reduced in hypertensive men, while only GLS (p < 0.05) was reduced in hypertensive women. Male gender and its interaction with hypertension were associated with higher LV mass and volume, decreased LV GRS, GCS, and GLS compared with hypertensive women. Multivariate analyses revealed that gender and LVEF were independently associated with GRS, GCS, and GLS (all p < 0.001) in hypertension. LV deformation is significantly reduced in hypertension, and gender may influence the response of LV deformation to hypertension, with men suffering more pronounced subclinical myocardial dysfunction. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 3.


Assuntos
Meios de Contraste , Disfunção Ventricular Esquerda , Estudos Transversais , Hipertensão Essencial , Feminino , Gadolínio , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Reprodutibilidade dos Testes , Disfunção Ventricular Esquerda/diagnóstico por imagem , Função Ventricular Esquerda
16.
J Lumin ; 2322021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34565833

RESUMO

Six dinuclear lanthanide(III) nitrato complexes [Ln(NO3)3(H2O)]2(µ-tppz) (where tppz = 2,3,5,6-tetra(2-pyridyl) pyrazine and Ln(III) = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), and Dy (6)) with bis-tridentate N-heterocyclic 2,3,5,6-tetra(2-pyridyl)pyrazine as bridging ligand have been solvothermally synthesized and characterized via elemental analysis, infrared spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction, and powder X-ray diffraction. The 3-D Hirshfeld surface and 2-D fingerprint plots show that the main interactions in 1-6 are the O⋯H/H⋯O intermolecular interactions with relative contributions of about 62%. Although the poor lanthanide(III)-centered luminescence properties clearly point to the efficiency of nonradiative quenching processes (presence of water molecules in the coordination sphere of the lanthanide(III) ions), the ligand tppz is better suited to sensitize the lanthanide(III)'s emissions of EuIII and NdIII than SmIII, TbIII, and DyIII. Finally, the magnetic data of DyIII comple×6 reveals antiferromagnetic coupling between DyIII ions.

17.
Cardiovasc Diabetol ; 19(1): 161, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32998742

RESUMO

BACKGROUND: Type 2 diabetes mellitus (T2DM) increases the risks of heart failure and mortality in patients with hypertension, however the underlying mechanism is unclear. This study aims to investigate the impact of coexisting T2DM on left ventricular (LV) deformation and myocardial perfusion in hypertensive individuals. MATERIALS AND METHODS: Seventy hypertensive patients without T2DM [HTN(T2DM-)], forty patients with T2DM [HTN(T2DM+)] and 37 age- and sex-matched controls underwent cardiac magnetic resonance examination. Left ventricular (LV) myocardial strains, including global radial (GRPS), circumferential (GCPS) and longitudinal peak strain (GLPS), and resting myocardial perfusion indices, including upslope, time to maximum signal intensity (TTM), and max signal intensity (MaxSI), were measured and compared among groups by analysis of covariance after adjusting for age, sex, body mass index (BMI) and heart rate followed by Bonferroni's post hoc test. Backwards stepwise multivariable linear regression analyses were performed to determine the effects of T2DM on LV strains and myocardial perfusion indices in patients with hypertension. RESULTS: Both GRPS and GLPS deteriorated significantly from controls, through HTN(T2DM-), to HTN(T2DM+) group; GCPS in HTN(T2DM+) group was lower than those in both HTN(T2DM-) and control groups. Compared with controls, HTN(T2DM-) group showed higher myocardial perfusion, and HTN(T2DM+) group exhibited lower perfusion than HTN(T2DM-) group and controls. Multiple regression analyses considering covariates of systolic blood pressure, age, sex, BMI, heart rate, smoking, indexed LV mass and eGFR demonstrated that T2DM was independently associated with LV strains (GRPS: p = 0.002, model R2= 0.383; GCPS: p < 0.001, model R2= 0.472; and GLPS: p = 0.002, model R2= 0.424, respectively) and perfusion indices (upslope: p < 0.001, model R2= 0.293; TTM: p < 0.001, model R2= 0.299; and MaxSI: p < 0.001, model R2= 0.268, respectively) in hypertension. When both T2DM and perfusion indices were included in the regression analyses, both T2DM and TTM were independently associated with GRPS (p = 0.044 and 0.017, model R2= 0.390) and GCPS (p = 0.002 and 0.001, model R2= 0.424), and T2DM but not perfusion indices was independently associated with GLPS (p = 0.002, model R2= 0.424). CONCLUSION: In patients with hypertension, T2DM had an additive deleterious effect on subclinical LV systolic dysfunction and myocardial perfusion, and impaired myocardial perfusion by coexisting T2DM was associated with deteriorated LV systolic dysfunction.


Assuntos
Circulação Coronária , Diabetes Mellitus Tipo 2/complicações , Cardiomiopatias Diabéticas/diagnóstico por imagem , Hipertensão Essencial/complicações , Imagem Cinética por Ressonância Magnética , Imagem de Perfusão do Miocárdio , Disfunção Ventricular Esquerda/diagnóstico por imagem , Função Ventricular Esquerda , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatologia , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/fisiopatologia , Hipertensão Essencial/diagnóstico , Hipertensão Essencial/fisiopatologia , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Medição de Risco , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia
18.
BMC Cardiovasc Disord ; 20(1): 450, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33059589

RESUMO

BACKGROUND: Cumulative evidence has shown that the non-invasive modality of coronary computed tomography angiography (CCTA) has evolved as an alternative to invasive coronary angiography, which can be used to quantify plaque burden and stenosis and identify vulnerable plaque, assisting in diagnosis, prognosis and treatment. With the increasing elderly population, many patients scheduled for non-cardiovascular surgery may have concomitant coronary artery disease (CAD). The aim of this study was to investigate the usefulness of preoperative CCTA to rule out or detect significant CAD in this cohort of patients and the impact of CCTA results to clinical decision-making. METHODS: 841 older patients (age 69.5 ± 5.8 years, 74.6% males) with high risk non-cardiovascular surgery including 771 patients with unknown CAD and 70 patients with suspected CAD who underwent preoperative CCTA were retrospectively enrolled. Multivariate logistic regression analysis was performed to determine predictors of significant CAD and the event of cancelling scheduled surgery in patients with significant CAD. RESULTS: 677 (80.5%) patients had non-significant CAD and 164 (19.5%) patients had significant CAD. Single-, 2-, and 3- vessel disease was found in 103 (12.2%), 45 (5.4%) and 16 (1.9%) patients, respectively. Multivariate analysis demonstrated that positive ECG analysis and Agatston score were independently associated with significant CAD, and the optimal cutoff of Agatston score was 195.9. The event of cancelling scheduled surgery was increased consistently according to the severity of stenosis and number of obstructive major coronary artery. Multivariate analysis showed that the degree of stenosis was the only independent predictor for cancelling scheduled surgery. In addition, medication using at perioperative period increased consistently according to the severity of stenosis. CONCLUSIONS: In older patients referred for high risk non-cardiovascular surgery, preoperative CCTA was useful to rule out or detect significant CAD and subsequently influence patient disposal. However, it might be unnecessary for patients with negative ECG and low Agatston score. Trial registration Retrospectively registered.


Assuntos
Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Programas de Triagem Diagnóstica , Tomografia Computadorizada Multidetectores , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Fatores Etários , Idoso , Tomada de Decisão Clínica , Doença da Artéria Coronariana/terapia , Estenose Coronária/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença
19.
Inorganica Chim Acta ; 489: 85-92, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34079145

RESUMO

Four mononuclear lanthanide complexes containing 4'-phenyl-2,2':6',2″-terpyridine (ptpy), [Ln(NO3)3(ptpy) (H2O)] (Ln = Eu (1), Gd (2), Tb (3), Dy (4)), were solvothermally synthesized and characterized via elemental analysis, infrared spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction, and powder X-ray diffraction. Hirshfeld surfaces and the solid-state luminescence properties of the complexes were investigated. The 3-D Hirshfeld surface and 2-D fingerprint plots show that the main interactions are the O H/H O intermolecular interactions in 1-4. Solid-state luminescence investigation reveals that GdIII complex 2 displays a ligand-centered emission and the EuIII, TbIII and DyIII complexes 1, 3 and 4 show the characteristic lanthanide-centered luminescence upon UV excitations. The EuIII and TbIII complexes exhibit red (CIE: 0.6549, 0.3447) and green (CIE: 0.3760, 0.5412) luminescence in the solid state with quantum yields of 16.8% and 0.8% and lifetimes of 0.545 and 0.043 ms, respectively. Density functional theory (DFT) calculations were conducted to unravel the HOMO-LUMO energy gaps of the structures of ptpy and complexes 1 and 3.

20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 635-9, 2016 Mar.
Artigo em Zh | MEDLINE | ID: mdl-27400496

RESUMO

The polycrystalline silicon thin films play an important role in the field of electronics. In the paper, α-SiAl composite membranes on glass substrates was prepared by magnetron co-sputtering. The contents of Al radicals encapsulated-in the α-Si film can be adjusted by changing the Al to Si sputtering power ratios. The as-prepared α-Si films were converted into polycrystalline films by using a rapid thermal annealing (RTP) at low temperature of 350 degrees C for 10 minutes in N2 atmosphere. An X-ray diffractometer, and Raman scattering and UV-Visible-NIR Spectrometers were used to characterize the properties of the Pc-Si films. The influences of Al content on the properties of the Pc-Si films were studied. The results showed that the polycrystalline silicon films were obtained from α-SiAl composite films which were prepared by magnetron co-sputtering at a low temperature following by a rapid thermal annealing. The grain size and the degree of crystallization of the Pc-Si films increased with the increase of Al content, while the optical band gap was reduced. The nc-Si films were prepared when the Al to Si sputtering power ratio was 0.1. And a higher Crystallization rate (≥ 85%) of polycrystalline silicon films were obtained when the ratio was 0.3. The band gaps of the polycrystalline silicon films can be controlled by changing the aluminum content in the films.

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