SrZnO nanostructures grown on templated <0001> Al2O3 substrates by pulsed laser deposition

The parameters of pulsed laser deposition (PLD) have been optimized to design different nanostructures of Strontium-alloyed zinc oxide (SrZnO). In this work, SrZnO nanostructures are grown on Al2O3 substrates via two-step templating/seeding approach. In the temperature range between 300 - 750 oC and O2 background pressures between 0.01 and 10 Torr, the growth conditions have been tailored to grow unique pointed leaf-like- and pitted olive-like nanostructures. Prior to the growth of the nanostructures, a thin SrZnO layer that serves as seed layer/template is first deposited on the Al2O3 substrates at ∼300oC and background oxygen pressure of 10 mTorr. The optical properties of the nanostructures were examined by UV/Vis spectroscopy and photoluminescence (PL), while the structures/morphologies were examined by SEM, TEM, and XRD. The alloyed SrZnO nanostructures, grown by ablating ZnO targets with 5, 10, 25% SrO contents, have in common a single-crystal hexagonal nanostructure with (0002) preferential orientation and have shown remarkable changes in the morphological and optical properties of the materials. To date, this is the only reported work on optimization of laser ablation parameters to design novel SrZnO nanostructures in the 5-25% alloying range, as most related Sr-doped ZnO studies were done below 7% doping. Although the physical properties of ZnO are modified via Sr doping, the mechanism remains unclear. The PLD-grown SrZnO nanostructures were directly grown onto the Al2O3 substrates; thus making these nanomaterials very promising for potential applications in biosensors, love-wave filters, solar cells, and ultrasonic oscillators

Robot-assisted partial nephrectomy for complex renal tumors: Analysis of a large multi-institutional database.

INTRODUCTION: Highly complex renal masses pose a challenge to urologic surgeons\u27 ability to perform robotic partial nephrectomy (RPN). Given the increased utilization of the robotic approach for small renal masses, we sought to characterize the outcomes and determine the safety and feasibility of RPN for complex renal masses from our large multi-institutional cohort. METHODS: We performed a retrospective analysis of patients with R.E.N.A.L. Nephrometry Scores ≥10 who underwent RPN in our multi-institutional cohort (N = 372). Baseline demographic, clinical and tumor related characteristics were evaluated with the primary endpoint of trifecta achievement (defined as negative surgical margin, no major complications, and warm ischemia time ≤25 min). Relationships between variables were assessed using the chi-square test of independence, Fisher exact test, Mann-Whitney U test, and Kruskal Wallis test. Logistic regression was used to evaluate the relationship between baseline characteristics and trifecta achievement. RESULTS: Of 372 patients in the study, mean age was 58 years, and median BMI was 30.49 kg/m CONCLUSION: RPN is a safe and reproducible procedure for complex tumors with R.E.N.A.L. Nephrometry scores ≥10. Our results suggest excellent rates of trifecta achievement and short-term functional outcomes when performed by experienced surgeons. Long-term oncological and functional evaluation are needed to further support this conclusion

A comparison of outcomes between transperitoneal and retroperitoneal robotic assisted partial nephrectomy in patients with completely endophytic kidney tumors.

INTRODUCTION: Retroperitoneal robotic partial nephrectomy (RPN) has been shown to have comparable outcomes to the transperitoneal approach for renal tumors. However, this may not be true for completely endophytic tumors as they pose significant challenges in RPN with increased complication rates. Hence, we sought to compare the safety and feasibility of retroperitoneal RPN to transperitoneal RPN for completely endophytic tumors. METHODS: We performed a retrospective analysis of patients who underwent RPN for a completely endophytic renal mass using either transperitoneal or retroperitoneal approach from our multi-institutional database (n = 177). Patients who had a solitary kidney, prior ipsilateral surgery, multiple/bilateral tumors, and horseshoe kidneys were excluded from the analysis. Overall, 156 patients were evaluated (112 [71.8%] transperitoneal, 44 [28.2%] retroperitoneal). Baseline characteristics, perioperative and postoperative data were compared between the surgical transperitoneal and retroperitoneal approach using Chi-square test, Fishers exact test, t test, Mood median test and Mann Whitney U test. RESULTS: Of the 156 patients in this study, 86 (56.9%) were male and the mean (SD) age was 58 (13) years. Baseline characteristics were comparable between the 2 approaches. Compared to transperitoneal approach, retroperitoneal approach had similar ischemia time (19.6 [SD = 7.6] minutes vs. 19.5 [SD = 10.2] minutes, P = 0.952), operative time (157.5 [SD = 44.8] minutes vs. 160.2 [SD = 47.3] minutes, P = 0.746), median estimated blood loss (50 ml [IQR: 50, 150] vs. 100 ml [IQR: 50, 200], P = 0.313), median length of stay (1 [IQR: 1, 2] day vs. 1 [IQR: 1, 2] day, P = 0.126) and major complication rate (2 [4.6%] vs. 3 [2.7%], P = 0.621). No difference was observed in positive surgical margin rate (P = 0.1.00), delta eGFR (P = 0.797) and de novo chronic kidney disease occurrence (P = 1.000). CONCLUSION: Retroperitoneal and transperitoneal RPN yielded similar perioperative and functional outcomes in patients with completely endophytic tumors. In well-selected patients with purely endophytic tumors, either a retroperitoneal or transperitoneal approach could be considered without compromising perioperative and postoperative outcomes

Transperitoneal Versus Retroperitoneal Robotic-Assisted Partial Nephrectomy in Patients with Obesity.

Introduction: We aim to compare transperitoneal (TP) and retroperitoneal (RP) robotic partial nephrectomy (RPN) in obese patients. Obesity and RP fat can complicate RPN, especially in the RP approach where working space is limited. Materials and Methods: Using a multi-institutional database, we analyzed 468 obese patients undergoing RPN for a renal mass (86 [18.38%] RP, 382 [81.62%] TP). Obesity was defined as body mass index ≥30 kg/m2*. A 1:1 propensity score matching was performed adjusting for age, previous abdominal surgery, tumor size, R.E.N.A.L nephrometry score, tumor location, surgical date, and participating centers. Baseline characteristics and perioperative and postoperative data were compared. Results: In the propensity score-matched cohort, 79 (50%) TP patients were matched with 79 (50%) RP patients. The RP group had more posterior tumors (67 [84.81%], RP versus 23 [29.11%], TP; P \u3c .001), while the other baseline characteristics were comparable. Warm ischemia time (interquartile range; 15 [10, 12], RP versus 14 [10, 17] minutes, TP; P = .216), operative time (129 [116, 165], RP versus 130 [95, 180] minutes, TP; P = .687), estimated blood loss (50 [50, 100], RP versus 75 [50, 150] mL, TP; P = .129), length of stay (1 [1, 1], RP versus 1 [1, 2] day, TP; P = .319), and major complication rate (1 [1.27%], RP versus 3 [3.80%], TP; P = .620) were similar. No significant difference was observed in positive surgical margin rate and delta estimated glomerular filtration at follow-up. Conclusion: TP and RP RPN yielded similar perioperative and postoperative outcomes in obese patients. Obesity should not be a factor in determining optimal approach for RPN