AS-183

Thick epitaxial BaTiO3 films ranging from 120 nm to 1 μm were grown by off-axis RF magnetron sputtering on SrTiO3-templated silicon-on-insulator (SOI) substrates for use in electro-optic applications, where such large thicknesses are necessary. The films are of high quality, rivaling those grown by molecular beam epitaxy (MBE) in crystalline quality, but can be grown 10 times faster. Extraction of lattice parameters from geometric phase analysis of atomic-resolution scanning transmission electron microscopy images revealed how the in-plane and out-of-plane lattice spacings of sputtered BaTiO3 changes as a function of layer position within a thick film. Our results indicate that compared to molecular beam epitaxy, sputtered films retain their out-of-plane polarization (c-axis) orientation for larger thicknesses. We also find an unusual re-transition from in-plane polarization (a-axis) to out-of-plane polarization (c-axis), along with an anomalous lattice expansion, near the surface. We also studied a method of achieving 100% a-axis-oriented films using a two-step process involving amorphous growth and recrystallization of a seed layer followed by normal high temperature growth. While this method is successful in achieving full a-axis orientation even at low thicknesses, the resulting film has a large number of voids and misoriented grains. Electro-optic measurement using a transmission setup of a sputtered BTO film grown using the optimized conditions yields an effective Pockels coefficient as high as 183 pm/V. A Mach-Zehnder modulator fabricated on such films exhibits phase shifting with an equivalent Pockels coefficient of 157 pm/V. These results demonstrate that sputtered BTO thick films can be used for integrated electro-optic modulators for Si photonics.

Herein, polyethylenimine (PEI)-grafted nitrogen (N)-doping magnetic biochar (PEIMW@MNBCBM) was synthesized, and characterization results showed that the microwave-assisted PEI grafting and ball milling-assisted N doping introduced abundant amino, pyridine N and pyrrole N structures onto biochar, which possessed high affinity to Cr(VI) in the anion form. The as-prepared PEIMW@MNBCBM displayed pH-dependence adsorption performance and high tolerance to co-existing ions with maximum uptake capacity of Cr(VI) identified as 183.02 mg/g. Furthermore, PEIMW@MNBCBM could bind Cr(VI) through electrostatic attraction, complexion, precipitation, reduction and pore filling. Especially, effective reduction of Cr(VI) was ascribed to cooperative electron transfer of partial oxygen-containing functional groups, intramolecular pyridine/pyrrole N, protonated amino and Fe2+ on the adsorbent, while oxygen-containing and amino functional groups from N-doping biochar and PEI synergistically complexed Cr(III) via providing lone pair electrons to form coordinate bonds. Furthermore, the stable precipitation was formed between Fe3+ and Cr(III). Additionally, the Cr(VI) elimination efficiency could maintain 95.83% even after four adsorption-desorption cycles, suggesting PEIMW@MNBCBM as a high-performance adsorbent for Cr(VI) contaminated water remediation.

Background: Fat accumulation in the visceral and subcutaneous regions can trigger fat necrosis during acute pancreatitis (AP). Aims: We investigated the role of visceral and subcutaneous fat in acute pancreatitis. In this study, we investigated the role of visceral and subcutaneous fat to understand the efficiency of adipose tissue in the AP. Materials and methods: Computed tomography of 68 patients and 68 healthy at the level of L4-5 intervertebral disc were analyzed for body adiposity composition using designated software. Body subcutaneous and visceral composition was measured by using the designated software of the CT. Results: Visceral fat was higher in the control group (198 ± 146) than the group of the AP (155 ± 118) (P = 0.038), whereas the subcutaneous fat was found higher in the AP instead (292 ± 133 to 139 ± 102; P = 0,001). Visceral fat (B = 0,29; P = 0,0013), gender (male) (B = -0.3; P = 0.0122), age (B = 0.274; P = 0.0087), and complication (B = -0.229; P = 0.007) predicted the subcutaneous fat as the dependent variable. In the receiver operating characteristic (ROC), the area under curve was 0.562 (0.402-0.636; 95% CI, P = 0.038) for the visceral fat, while it was 0.906 (0.824-0.962; 95% CI, P < 0.0001) for the subcutaneous fat. Its cutoff was calculated as 183.7 for subcutaneous fat. Conclusion: Visceral fat analysis showed a contradiction according to subcutaneous fat that AP was strongly associated with subcutaneous one. The result supports that visceral and subcutaneous fat tissues should have different path of inflammation affecting the AP.