Revisited Ti2Nb2O9 as an Anode Material for Advanced Li-Ion Batteries.

Ti2Nb2O9 with a tunnel-type structure is considered as a perspective negative electrode material for Li-ion batteries (LIBs) with theoretical capacity of 252 mAh g-1 corresponding to one-electron reduction/oxidation of Ti and Nb, but only ≈160 mAh g-1 has been observed practically. In this work, highly reversible capacity of 200 mAh g-1 with the average (de)lithiation potential of 1.5 V vs Li/Li+ is achieved for Ti2Nb2O9 with pseudo-2D layered morphology obtained via thermal decomposition of the NH4TiNbO5 intermediate prepared by K+→ H+→ NH4+ cation exchange from KTiNbO5. Using operando synchrotron powder X-ray diffraction (SXPD), single-phase (de)lithiation mechanism with 4.8% unit cell volume change is observed. Operando X-ray absorption near-edge structure (XANES) experiment revealed simultaneous Ti4+/Ti3+ and Nb5+/Nb4+ reduction/oxidation within the whole voltage range. Li+ migration barriers for Ti2Nb2O9 along [010] direction derived from density functional theory (DFT) calculations are within the 0.15-0.4 eV range depending on the Li content that is reflected in excellent C-rate capacity retention. Ti2Nb2O9 synthesized via the ion-exchange route appears as a strong contender to widely commercialized Ti-based negative electrode material Li4Ti5O12 in the next generation of high-performance LIBs.

"Valve"-Type Retainment of Flexible Ureteroscope in the Distal Ureter.

Introduction: Flexible ureteroscopy (fURS) is an endoscopic procedure for the minimally invasive treatment of ureteral and renal calculi. Due to improvements in technique and ureteroscopic instrumentation over the past two decades, complications associated with URS are infrequent. However, in the event of an unexpected device malfunction or failure, the operating surgeon must employ prompt, resolute decision-making to resolve any intraoperative complications and avoid significant injury to the kidney or ureter. Case Presentation: The patient was a 53-year-old male with a 7 mm left upper pole renal stone managed by fURS and laser lithotripsy. A ureteral access sheath (UAS) was not deployed during the procedure. During fragmentation of the stone, we were unexpectedly unable to retract the ureteroscope from the ureter. Herein, we describe the procedural details leading up to the complication and the careful maneuvering required to remove the ureteroscope without damaging the ureter or the instrument. Conclusions: We recommend use of a UAS during fURS for the treatment of ureteral and renal calculi, if not using ureter access sheath, not advancing the ureteroscope above the stone, leaving it behind the tip of the instrument, while in the ureter. Utilization of a ureter access sheath could have possibly avoided this kind of complication.

Evaluation of the effect of Bernoulli maneuver on operative time during mini-percutaneous nephrolithotomy: A prospective randomized study.

PURPOSE: To evaluate the effect of 'Bernoulli maneuver' (bringing the access sheath to horizontal plane) on operative time and stone free rates in patients undergoing mini-percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: All consecutive patients with a solitary kidney stone undergoing a mini-PCNL between 2015 and 2016 were included into this study. Patients were randomized either to standard prone or control (C) group patients or to tilted prone with 'Bernoulli maneuver' group (B) patients. Pre-, intra-, and postoperative characteristics of these 2 groups were recorded and analyzed. RESULTS: A total of 67 patients were included in the study. Of these, 40 patients were randomized to group C and 27 to group B. The mean (95% confidence limits) stone size (mm) in group C and B was 14 (13, 15) and 13 (11, 14), respectively (p=0.26). Nephroscopy time was shorter in Bernoulli group (35 minutes vs. 23 minutes, p=1.5·10-5, and Bayes factor BF10=2,340, and Cohen standardized effect size dst=1.2). The difference made it up 12 minutes (with 95% confidence interval from 8 to 18 minutes). There were no statistically significant differences between groups regarding white blood cell, creatinine level and stone-free status defined by computed tomography on the first postoperative day. CONCLUSIONS: In our study the 'Bernoulli maneuver' led to a shorter nephroscopy time in mini-PCNL. This maneuver can significantly reduce nephroscopy time and save significant amount of operative time, especially in tertiary referral centers with high-volume mini-PCNL procedures.

Ultrasound-Guided Ureteral Stent Removal in Women.

OBJECTIVES: The purpose of this study was to develop a fast, comfortable, and safe method of ureteral stent removal in women. METHODS: From February 2014 to July 2015, a retrospective multicenter controlled study including 82 female outpatients was conducted. The control group was composed of 46 patients who underwent stent removal using a 22F cystoscope. The experimental group was composed of 36 patients who underwent stent removal under ultrasound guidance with a 15F spiral-ending device. Exclusion criteria were pelvic organ prolapse quantification stage II or higher and complicated stents (with migration or encrustation). RESULTS: All studied patients had successful ureteral stent removal. No complications were seen in both groups. Differences between mean visual analog pain scale scores and stent removal durations were statistically significant in favor of the experimental group (P = .0077 and .0075, respectively). CONCLUSIONS: The proposed method for ureteral stent removal in women under ultrasound guidance was shown to be faster and to have lower visual analog pain scale scores, in comparison with removal by a cystoscope, which makes it an attractive option for outpatient urologic praxis in uncomplicated cases, and because it is free of the risk of ionizing radiation and more comfortable, it can be used in pregnant patients.

Sculpturing in urology, or how to make percutaneous nephrolithotomy easier.

PURPOSE: To investigate the usefulness of Plasticine biomodeling in surgical percutaneous management of complex renal stone. PATIENTS AND METHODS: A total of 32 patients with complex renal stones (complete staghorn stones or partial staghorn stone with multiple caliceal stones) were included in this study from 2012 to 2013. Computed tomography (CT) urography with three-dimensional (3D) reconstructions was used as standard preoperative imaging in all patients. Preoperatively, Plasticine replication of the pelvicaliceal system was performed by the operating surgeon, based on the gathered 3D reconstructions. Then the model was taken to the operating room and used as a reference model in a sterile polyethylene bag during the operation. RESULTS: Percutaneous renal access was achieved successfully in all cases. Twenty-nine (91%) patients were treated in the prone position and only 3 (9%) in supine position. There were 18 (56%) patients who had a single tract, 9 (28%) patients had two tracts, 3 (9%) patients had three tracts, and one (3%) patient needed four tracts. The mean operative time was 92 (±26) minutes. Second-look percutaneous nephrolithotomy (PCNL) was needed in 9 of 32 (28%) patients. All second-look sessions were performed in 2 to 3 days and/or on a normalized temperature. Six of 11 (54.5%) patients with complete staghorn stones needed a second-look PCNL session. Complete stone clearance was confirmed by low-dose CT, performed at 24 hours after surgery, in 89.4% of the patients treated by a single PCNL session and 82% in those who needed second-look sessions. The overall stone-free rate (SFR) in the study after second looks was 87.3%. CONCLUSIONS: The proposed Plasticine 3D model seems to provide better preoperative renal collecting system appreciation and to serve as a reference tool during the operation, which in turn might increase SFRs and lower the complications rate after PCNL.