Recent Developments in (K, Na)NbO3-Based Lead-Free Piezoceramics.

(K0.5Na0.5)NbO3 (KNN)-based ceramics have been extensively investigated as replacements for Pb(Zr, Ti)O3-based ceramics. KNN-based ceramics exhibit an orthorhombic structure at room temperature and a rhombohedral-orthorhombic (R-O) phase transition temperature (TR-O), orthorhombic-tetragonal (O-T) phase transition temperature (TO-T), and Curie temperature of -110, 190, and 420 °C, respectively. Forming KNN-based ceramics with a multistructure that can assist in domain rotation is one technique for enhancing their piezoelectric properties. This review investigates and introduces KNN-based ceramics with various multistructures. A reactive-templated grain growth method that aligns the grains of piezoceramics in a specific orientation is another approach for improving the piezoelectric properties of KNN-modified ceramics. The piezoelectric properties of the [001]-textured KNN-based ceramics are improved because their microstructures are similar to those of the [001]-oriented single crystals. The improvement in the piezoelectric properties after [001] texturing is largely influenced by the crystal structure of the textured ceramics. In this review, [001]-textured KNN-based ceramics with different crystal structures are investigated and systematically summarized.

Clinical performance assessment of five human papillomavirus DNA tests using liquid-based cytology samples.

AIM: To evaluate the performance of five HPV tests (Hybrid Capture 2, Linear Array [LA], DNA chip, type-specific polymerase chain reaction [PCR], and sequencing) in detecting high-risk (HR) HPV DNA and high-grade cervical intraepithelial neoplasia (CIN) and cancer. MATERIAL AND METHODS: A total of 137 women with abnormal cytologies were prospectively enrolled. The diagnostic accuracy of five HPV DNA tests in detecting high-grade CIN and cancer was assessed, and the concordance among HPV genotyping tests was evaluated. All specimens were obtained from cervical swab samples preserved in residual PreservCyt solution that were originally collected for ThinPrep Pap test. RESULTS: The sensitivities of all five HPV tests did not differ significantly among the five HPV tests. The overall concordance level was excellent between LA and sequencing (98.2%, Kappa = 0.9) and was substantial between DNA chip and sequencing (96.4%, Kappa = 0.8). The concordance levels for detecting vaccine-type (HPV 16 and 18) of LA in comparison with DNA chip, type-specific PCR, and sequencing were substantial (Kappa = 0.67, 0.64, and 0.65, respectively). The sensitivities for all five HPV tests were >90% for the detection of CIN2 or higher. No statistically significant differences in sensitivity occurred between any of the tests. CONCLUSION: All five HPV tests showed reliable results in detecting HR HPVs, high-grade CIN, and cancer. Both LA and DNA chip tests may be useful in identifying HR HPV, especially when multiple genotypes are present.

Association between serum cytokine profiles and clearance or persistence of high-risk human papillomavirus infection: a prospective study.

INTRODUCTION: The cytokines that may be associated with the clearance or persistence of high-risk human papillomavirus (HPV) infection in patients with mild dysplasia or less of the uterine cervix were determined. METHODS: A prospective study of 160 patients who harbored high-risk HPV with histologically confirmed mild dysplasia or less between January 2006 and August 2008 was performed. All patients were followed up at every 4 months during the first year. Human papillomavirus DNA tests by the Hybrid Capture 2 method (Digene, Gaithersburg, Md) were performed at every visit on all patients. Blood sampling was performed in all patients at their initial visit, and an enzyme-linked immunosorbent assay was used to measure the serum levels of interferon gamma, tumor necrosis factor alpha, and interleukins 6 and 10. RESULTS: Of the 160 patients, 107 (66.9%) had clearance of HPV infection after 12 months of follow-up. The median age of patients in the persistence group was significantly higher than that of patients in the clearance group (47 vs 38 years, respectively; range, 21-77 vs 21-71 years, respectively; P = 0.0009). In univariate analysis, the number of patients with serum negative for tumor necrosis factor alpha was significantly higher in the clearance group than the persistence group (P = 0.0363). However, in multivariate logistic regression analysis, all 4 cytokines failed to show any significant association with the clearance or persistence of HPV infection. CONCLUSIONS: The baseline serum cytokine levels were not associated with the clearance or persistence of HPV infection. Systemic immunity may not influence the natural history of HPV infection.