Visible-ultraviolet spectroscopic ellipsometry of lead zirconate titanate thin films

We measured pseudodielectric functions in the visible-ultraviolet spectral range of Pb(ZrxTi1−x)O3 (x=0.2, 0.56, 0.82) (PZT)grown on platinized silicon substrate using the sol-gel method and also on (0001) sapphire using radio frequency sputtering method. Using a parametric optical constant model, we estimated the dielectric functions of the PZTthin films. Taking the second derivative of the fitted layer dielectric functions and using the standard critical point model, we determined the parameters of the critical points. In the second derivative spectra, the lowest bandgap energy peak near 4eV is fitted as a double peak for annealedPZTs associated with the perovskite phase. As-grown PZTs have mainly pyrochlore phase and the lowest bandgap is fitted as a single peak. We compared the bandgap energies with literature values

Diagnostic Value of Galectin-3, HBME-1, Cytokeratin 19, High Molecular Weight Cytokeratin, Cyclin D1 and p27kip1 in the Differential Diagnosis of Thyroid Nodules

The distinction between benign and malignant thyroid tumors is critical for the management of patients with thyroid nodules. We applied immunohistochemical staining for galectin-3, HBME-1, cytokeratin 19 (CK19), high molecular weight cytokeratin (HMWCK), cyclin D1 and p27kip1 in 295 thyroid lesions to determine their diagnostic accuracy. The expression of all markers was significantly associated with differentiated thyroid carcinoma (DTC).The sensitivity for the diagnosis of DTC was 94.7% with galectin-3, 91.3% with HBME-1, and 90.3% with CK19. The specificities of these markers were 95.5%, 69.7%, and 83.1%, respectively. Combining these markers, co-expression of galectin-3 and CK19 or galectin-3 and HBME-1 was seen in 93.2% of carcinomas but in none of the benign nodules. Comparing follicular variant of papillary carcinoma (FVPC) with follicular carcinoma (FC), the expression of galectin-3, CK19, and HMWCK was significantly higher in FVPC. When comparing FC with FA, the expression of galectin-3 and HBME-1 was significantly higher in FC. These results suggest that 1) galectin-3 is a useful marker in the distinction between benign and malignant thyroid tumors, 2) the combined use of HBME-1 and CK19 can increase the diagnostic accuracy, and 3) the use of CK19 and HMWCK can aid in the differential diagnosis between PC and FC

Fabrication and current-voltage characterization of a ferroelectric lead zirconate titanate/AlGaN∕GaN field effect transistor

We demonstrated ferroelectricfield effect transistors (FFETs) with hysteretic I-V characteristics in a modulation-doped field effect transistors(MODFET)AlGaN∕GaN platform with ferroelectricPb(Zr,Ti)O3 between a GaN channel and a gate metal. The pinch-off voltage was about 6–7V comparable to that of conventional Schottky gate MODFET. Counterclockwise hysteresis appeared in the transfer characteristics with a drain current shift of ∼5mA for zero gate-to-source voltage. This direction is opposite and much more pronounced than the defect induced clockwise hysteresis in conventional devices, which suggests that the key factor contributing to the counterclockwise hysteresis of the FFET is the ferroelectric switching effect of the lead zirconate titanate gate

Decreased Angiotensin II -Stimulated Aldosterone Production, but Normal Inositol Phosphate Response in Adrenal Glomerulosa Cells from Streptozotocin-Induced Diabetic Rats: Role of lnsulin

Streptozotocin(SlZ)-induced diabetic rats develop hyporeninemic hypoaldosteronism during the progression of diabetes mellitus. However,the nature and mechanism of aldosterone deficiency in diabetic rats still remain unclear and acute effects of insulin on aldosterone production in-vitro are not known. We evaluated the responses of aldosterone production to angiotensin 11 (AlI), potassium (K+), AClH and insulin in adrenal glomerulosa cells prepared from SlZ-induced diabetic rats with and without insulin treatment 2 weeks after diabetes induction. We also measured inositol phosphate<IP) levels in All-stimulated glomerulosa cells labeled with [3HI myoinositol using standardized anion exchange chromatography. Plasma renin activity and aldosterone level were not different among control rats,untreated and insulin-treated diabetic rats. Basal aldosterone production was similar in cells from the three groups. Cells from untreated diabetic rats showed a significant decrease in the maximal All (to-8M)-stimuiated aldosterone production and a tendency to be low in the maximal K+(8.7 mM)-stimulated aldosterone production, compared with control rats (3.2±2.2 \IS 7.7±2.4, P (0.05 and 4.8±1.8 \IS 8.0±3.2 ng/105 cells/hr, 0.05 (P (0.1, respectively). In contrast, there were no differences in All- and K+-stimulated aldosterone production between control and insulin-treated diabetic rats. AClH (to-8M), however, caused a similar effect on aldosterone production and insulin (I mU /ml for 1 hour) did not alter either basal or agonists-stimulated aldosterone production in cells from the three groups. All (to-8M)-induced IP formation among the three groups was similar and did not change with the addition of insulin u mU / ml), These results indicate that reduced response to All in the early phase of SlZ-induced diabetes in rats may be due to the zona glomerulosa dysfunction secondary to chronic lack of insulin and the main defect responsible for altered All effects may be located at some step(s) mediating All action downstream from IP formation

Dielectric functions and electronic band structure of lead zirconate titanate thin films

We measure pseudodielectric functions in the visible-deep ultraviolet spectral range of Pb(ZrxTi1−x)O3 (x=0.2,0.56,0.82) (PZT), Pb0.98Nb0.04 (Zr0.2Ti0.8)0.96O3, Pb0.91La0.09 (Zr0.65Ti0.35)0.98O3, and Pb0.85La0.15Ti0.96O3 films grown on platinized silicon substrates using a sol-gel method and on (0001) sapphire using a radio-frequency sputtering method. Using a parametric optical constant model, we estimate the dielectric functions(ϵ) of the perovskite oxide thin films. Taking the second derivative of the fitted layer dielectric functions and using the standard critical-point model, we determine the parameters of the critical points. In the second derivative spectra, the lowest band-gapenergy peak near 4 eVis fitted as a double peak for annealed PZTs due to the perovskite phase. As-grown PZTs have mainly pyrochlore phase and the lowest band-gap peak is fitted as a single peak. We also examine the effect of dopants La and Nb, which substitute at Pb and Zr (Ti) sites, respectively. We found three band gaps Ea(∼3.9eV), Eb (∼4.5eV), and Ec (∼6.5eV) in the order of increasing energy. The Ea and Eb band-gap energies were not sensitive to Zr composition. We discuss the change of critical-point parameters for PZTs in comparison to the band-structure calculations based on local-density approximation. The near constancy of the lowest band-gap energy independent of Zr composition is consistent with the band-structure calculations

전립선 선암종에서 Methylenetetrahydrofolate Reductase 유전자형에 따른 CpG 섬 좌, LINE-1 및 Alu의 메틸화 양상 분석

Background : Genetic polymorphism of methylenetetrahydrofolate reductase (MTHFR), in association with the influence of MTHFR upon DNA methylation, may cause differences of the methylation profile of cancer. Thus, we investigated the relationship between the methylation status of prostate adenocarcinoma and the genetic polymorphism of MTHFR. Methods : We examined 179 cases of prostate adenocarcinoma for determining the genotypes of MTHFR 677 and 1298, the methylation status of 16 CpG island loci and the methylation levels of the LINE-1 and Alu repeats with using polymerase chain reaction/restriction fragment length polymorphism, methylation-specific polymerase chain reaction and combined bisulphite restriction analysis, respectively. Results : There was a higher proportion of the CT genotype of MTHFR 677 in the prostate adenocarcinoma than that in the normal control. The TT genotype of MTHFR 677 showed the highest frequency of methylation in six out of nine major CpG island loci, and these were which were frequently hypermethylated in prostate adenocarcinoma. The CT type showed the lowest methylation levels of LINE-1 and Alu among the MTHFR 677 genotypes. Interestingly, the CC type of MTHFR 1298 demonstrated favorable prognostic factors. Conclusions : Our study is the first to examine the methylation profile of prostate adenocarcinoma according to the MTHFR genotypes. The differences of the cancer risk, the genomic hypomethylation and the prognosis between the MTHFR genotypes in prostate adenocarcinoma should be further explored.Johansson M, 2007, CANCER CAUSE CONTROL, V18, P1169, DOI 10.1007/s10552-007-9055-zHubner RA, 2007, INT J CANCER, V120, P1027, DOI 10.1002/ijc.22440Cho NY, 2007, J PATHOL, V211, P269, DOI 10.1002/path.2106Pereira TV, 2006, CANCER EPIDEM BIOMAR, V15, P1956, DOI 10.1158/1055-9965.EPI-06-0334Larsson SC, 2006, GASTROENTEROLOGY, V131, P1271, DOI 10.1053/j.gastro.2006.08.010Cadieux B, 2006, CANCER RES, V66, P8469, DOI 10.1158/0008-5472.CAN-06-1547Graziano F, 2006, INT J CANCER, V118, P628, DOI 10.1002/ijc.21397Karpf AR, 2005, CANCER RES, V65, P8635, DOI 10.1158/0008-5472Kono S, 2005, CANCER SCI, V96, P535, DOI 10.1111/j.1349-7006.2005.00090.xLe Marchand L, 2005, CANCER EPIDEM BIOMAR, V14, P1198Friso S, 2005, CURR DRUG METAB, V6, P37Weisenberger DJ, 2005, NUCLEIC ACIDS RES, V33, P6823, DOI 10.1093/nar/gki987Chalitchagorn K, 2004, ONCOGENE, V23, P8841, DOI 10.1038/sj.onc.1208137Cicek MS, 2004, CANCER EPIDEM BIOMAR, V13, P1331Castro R, 2004, J MED GENET, V41, P454, DOI 10.1136/jmg.2003.017244Kim YI, 2004, CANCER EPIDEM BIOMAR, V13, P511Yang AS, 2004, NUCLEIC ACIDS RES, V32, DOI 10.1093/nar/gnh032Nelson WG, 2003, NEW ENGL J MED, V349, P366Gaudet F, 2003, SCIENCE, V300, P489Bariol C, 2003, AM J PATHOL, V162, P1361Shen HB, 2001, INT J CANCER, V95, P332, DOI 10.1002/1097-0215(20010920)95:53.0.CO2-9Kimura F, 2000, PROSTATE, V45, P225Weisberg I, 1998, MOL GENET METAB, V64, P169Esteller M, 1997, CARCINOGENESIS, V18, P2307Blount BC, 1997, P NATL ACAD SCI USA, V94, P3290Ma J, 1997, CANCER RES, V57, P1098Chen J, 1996, CANCER RES, V56, P4862FROSST P, 1995, NAT GENET, V10, P111