The temperature-dependence behaviors of ferroelectric, piezoelectric, kp and electrical-field-induced strain were carefully evaluated for high-performance BiFeO3–0.3BaTiO3 (BF–0.3BT) ceramics. There results indicate, combined with Rayleigh analysis and temperature-dependence XRD and PFM, that the increase of strain and large signal with increasing the temperature from room temperature to 180 °C is related to the joint effect of intrinsic contribution (lattice expansion) and extrinsic contribution (domain switching). With further increasing the temperature to 300 °C, the large signal d33 and electrical-field-induced strain mildly decrease because of the increase of conductivity for BF–0.3BT ceramics. However, different from strain and large signal the small signal d33(E0) and kp exhibit excellent temperature stability behavior as the temperature increases from room temperature to 300 °C.The temperature-dependence behaviors of ferroelectric, piezoelectric, kp and electrical-field-induced strain were carefully evaluated for high-performance BiFeO3–0.3BaTiO3 (BF–0.3BT) ceramics.相似文献
BackgroundAfrican American and Hispanic postmenopausal women have the highest risk for heart failure compared with other races, but heart failure prevalence is lower than expected in some national cohorts. It is unknown whether psychosocial factors are associated with lower risk of incident heart failure hospitalization among high-risk postmenopausal minority women.Methods and ResultsUsing the Women's Health Initiative Study, African American and US Hispanic women were classified as high-risk for incident heart failure hospitalization with 1 or more traditional heart failure risk factors and the highest tertile heart failure genetic risk scores. Positive psychosocial factors (optimism, social support, religion) and negative psychosocial factors (living alone, social strain, depressive symptoms) were measured using validated survey instruments at baseline. Adjusted subdistribution hazard ratios of developing heart failure hospitalization were determined with death as a competing risk. Positive deviance indicated not developing incident heart failure hospitalization with 1 or more risk factors and the highest tertile for genetic risk. Among 7986 African American women (mean follow-up of 16 years), 27.0% demonstrated positive deviance. Among high-risk African American women, optimism was associated with modestly reduced risk of heart failure hospitalization (subdistribution hazard ratio 0.94, 95% confidence interval 0.91–0.99), and social strain was associated with modestly increased risk of heart failure hospitalization (subdistribution hazard ratio 1.07, 95% confidence interval 1.02–1.12) in the initial models; however, no psychosocial factors were associated with heart failure hospitalization in fully adjusted analyses. Among 3341 Hispanic women, 25.1% demonstrated positive deviance. Among high-risk Hispanic women, living alone was associated with increased risk of heart failure hospitalization (subdistribution hazard ratio 1.97, 95% confidence interval 1.06–3.63) in unadjusted analyses; however, no psychosocial factors were associated with heart failure hospitalization in fully adjusted analyses.ConclusionsAmong postmenopausal African American and Hispanic women, a significant proportion remained free from heart failure hospitalization despite having the highest genetic risk profile and 1 or more traditional risk factors. No observed psychosocial factors were associated with incident heart failure hospitalization in high-risk African Americans and Hispanics. Additional investigation is needed to understand protective factors among high-risk African American and Hispanic women. 相似文献
The purpose of the study was to evaluate the feasibility of using contrast-enhanced computed tomography (CECT)-based texture analysis (CTTA) metrics to differentiate between juxtatumoral perinephric fat (JPF) surrounding low-grade (ISUP 1–2) versus high-grade (ISUP 3–4) clear cell renal cell carcinoma (ccRCC).
Methods
In this IRB-approved study, we retrospectively queried the surgical database between June 2009 and April 2016 and identified 83 patients with pathologically confirmed ccRCC (low grade: n = 54, mean age = 61.5 years, 18F/35M; high grade n = 30, mean age = 61.7 years, 8F/22M) who also had pre-operative multiphase CT acquisitions. CT images were transferred to a 3D workstation, and nephrographic phase JPF regions were manually segmented. Using an in-house developed Matlab program, a CTTA panel comprising of texture metrics extracted using six different methods, histogram, 2D- and 3D-Gray-level co-occurrence matrix (GLCM) and Gray-level difference matrix (GLDM), and 2D-Fast Fourier Transform (FFT) analyses, was applied to the segmented images to assess JPF textural heterogeneity in low- versus high-grade ccRCC. Univariate analysis and receiver-operator characteristics (ROC) analysis were used to assess interclass differences in texture metrics and their prediction accuracy, respectively.
Results
All methods except GLCM consistently revealed increased heterogeneity in the JPF surrounding high- versus low-grade ccRCC. FFT showed increased complexity index (p < 0.01). Histogram analysis showed increased kurtosis and positive skewness in (p < 0.03), and GLDM analysis showed decreased measure of correlation coefficient (MCC) (p < 0.04). Several of the GLCM metrics showed statistically significant (p < 0.04) textural differences between the two groups, but with no consistent trend. ROC analysis showed that MCC in GLCM analysis had an area under the curve of 0.75.
Conclusions
Our study suggests that CTTA of ccRCC shows statistically significant textural differences in JPF surrounding high- versus low-grade ccRCC.
Background:We performed a meta-analysis to more precisely evaluate the association between the cytotoxic T lymphocyte-associated protein 4 (CTLA-4) -1772T/C polymorphism and overall gastric cancer (GC) risk and the influence of ethnicity and the source of controls on that association.Methods:A systematic literature search was performed in PubMed, EMBASE, the Cochrane Library, Web of Science (WOS) Database, Chinese National Knowledge Infrastructure (CNKI), China biomedical literature database (CBM), Wanfang database, and VIP. Two investigators independently reviewed the articles, and disagreements were resolved by discussion and consensus. The odds ratio (OR) with 95% confidence intervals (CIs) was used to assess the strength of the association between the CTLA-4 -1722T/C polymorphism and GC risk, based on the genotype frequencies in cases and controls. The meta-analyses were performed with Stata 12.0, using two-sided P values. Trial sequential analysis (TSA) was calculated by TSA Software.Results:Overall, we identified 5 studies including 1039 GC cases and 2136 controls that evaluated the association of the CTLA-4 -1722T/C polymorphism and GC risk. Overall, there was no significant association between the CTLA-4-1722T/C polymorphism and the risk of GC. In the subgroup analysis based on ethnicity, the results showed that the relationship between the CTLA-4 -1722T/C polymorphism and GC susceptibility was strongest in the Chinese population rather than in the Iranian population (TC vs CC: OR = 1.405, 95% CI: 1.100–1.796, P = .007; TC+TT vs CC: OR = 1.329, 95% CI: 1.052–1.680, P = .017). Then, there was a significant association between the CTLA-4 -1722T/C polymorphism and the risk of GC in studies with HB controls. However, the above correlation can only be reflected in specific populations and gene models. Therefore, we believe that the evidence of this correlation is insufficient.Conclusion:Our meta-analysis showed that the CTLA-4 -1722T/C polymorphism may be associated with the susceptibility to GC. However, the slight correlation can only be reflected in specific populations and gene models. Therefore, we believe that this association is negligible. The large and well-designed case-control studies are needed to validate our findings. 相似文献