Ex-vivo ureteroscopy, laser lithotripsy, and stone basketing extraction of deceased donor kidney stones during machine perfusion preservation

The incidence of nephrolithiasis in kidney donors is rare. The timing and treatment of nephrolithiasis in deceased donor kidneys are not well established. While some programs have proposed ex-situ rigid or flexible ureteroscopy treatment before transplantation, we report on two cases of kidney stones in the same deceased donor that we treated by flexible ureteroscopy and laser lithotripsy performed during the storage time on a hypothermic perfusion machine. Two deceased donor kidneys were found to have multiple kidney stones discovered on preprocurement CT imaging. The right kidney had less than five 2-3 mm stones, whereas the left had five to ten 1 mm stones with a single 7 mm stone. Both organs were placed on a hypothermic perfusion machine and maintained at a temperature of 4°C. An ex-vivo flexible ureteroscopy with laser lithotripsy and basket extraction was performed while the kidneys were maintained on Lifeport* perfusion machine. The cold ischemia time was 16.9 and 23.1 h. After 12 months of observational follow-up, neither recipient had nephrolithiasis, UTI, or other urologic complications. The creatinine values now are 1.17 and 2.44 mg/dL (103.4 and 215.7 μmol/L), respectively. Ex-vivo flexible ureteroscopy with laser lithotripsy and stone removal on machine-perfused kidneys appears to be safe and offers a good option to treat graft nephrolithiasis and prevent posttransplant complications. Ureteroscopy serves as a minimally invasive treatment option with direct stone removal. Performing this while on machine perfusion minimizes the ischemic time of the kidney and resultant complications or delays in graft function.

ZnO Nanoparticle/Graphene Hybrid Photodetectors via Laser Fragmentation in Liquid

By combining the enhanced photosensitive properties of zinc oxide nanoparticles and the excellent transport characteristics of graphene, UV-sensitive, solar-blind hybrid optoelectronic devices have been demonstrated. These hybrid devices offer high responsivity and gain, making them well suited for photodetector applications. Here, we report a hybrid ZnO nanoparticle/graphene phototransistor that exhibits a responsivity up to 4 × 104 AW-1 and gain of up to 1.3 × 105 with high UV wavelength selectivity. ZnO nanoparticles were synthesized by pulsed laser fragmentation in liquid to attain a simple, efficient, ligand-free method for nanoparticle fabrication. By combining simple fabrication processes with a promising device architecture, highly sensitive ZnO nanoparticle/graphene UV photodetectors were successfully demonstrated.

Laser-Generated Supranano Liquid Metal as Efficient Electron Mediator in Hybrid Perovskite Solar Cells

Creating colloids of liquid metal with tailored dimensions has been of technical significance in nano-electronics while a challenge remains for generating supranano (<10 nm) liquid metal to unravel the mystery of their unconventional functionalities. Present study pioneers the technology of pulsed laser irradiation in liquid from a solid target to liquid, and yields liquid ternary nano-alloys that are laborious to obtain via wet-chemistry synthesis. Herein, the significant role of the supranano liquid metal on mediating the electrons at the grain boundaries of perovskite films, which are of significance to influence the carriers recombination and hysteresis in perovskite solar cells, is revealed. Such embedding of supranano liquid metal in perovskite films leads to a cesium-based ternary perovskite solar cell with stabilized power output of 21.32% at maximum power point tracing. This study can pave a new way of synthesizing multinary supranano alloys for advanced optoelectronic applications.

Manipulation of the Size and Phase Composition of Yttrium Iron Garnet Nanoparticles by Pulsed Laser Post-Processing in Liquid

Modification of the size and phase composition of magnetic oxide nanomaterials dispersed in liquids by laser synthesis and processing of colloids has high implications for applications in biomedicine, catalysis and for nanoparticle-polymer composites. Controlling these properties for ternary oxides, however, is challenging with typical additives like salts and ligands and can lead to unwanted byproducts and various phases. In our study, we demonstrate how additive-free pulsed laser post-processing (LPP) of colloidal yttrium iron oxide nanoparticles using high repetition rates and power at 355 nm laser wavelength can be used for phase transformation and phase purification of the garnet structure by variation of the laser fluence as well as the applied energy dose. Furthermore, LPP allows particle size modification between 5 nm (ps laser) and 20 nm (ns laser) and significant increase of the monodispersity. Resulting colloidal nanoparticles are investigated regarding their size, structure and temperature-dependent magnetic properties.

Safety and efficacy of ureteroscopy and stone fragmentation for pediatric renal stones: a systematic review

Flexible ureteroscopy (FURS) is now commonly used for the treatment of paediatric renal stones. We conducted a systematic review of literature looking at the outcomes of flexible ureteroscopy and laser lithotripsy (FURSL) for paediatric stone disease. A systematic review was conducted in a Cochrane style and in accordance PRISMA checklist using MEDLINE, CINAHL, EMBASE, Scopus, and Cochrane library for all English language articles in patients ≤18 years from 1990-2018 who underwent FURSL. A total of 11 studies reported on 431 patients, with a mean age of 8.5 years (range, 0.25-17 years). The mean stone size was 13 mm (range, 1.5-30 mm). The overall stone free rate (SFR) was 87% (58-100%) with a mean complication rate of 12.6% (n=55) (range, 0-31.3%) and 76% needing a post-operative ureteric stent insertion. Of the complications, Clavien I/II complications included fever and urinary tract infection (UTI) (n=19), haematuria (n=7), stent discomfort/stent symptoms/post-operative pain (n=8), voiding disturbance (n=2) and post-operative nausea and vomiting (n=1). Clavien III complications included ureteral injury which included perforation (n=6), urinoma (n=1), and acute urinary retention secondary to stone fragmentation (n=1). Clavien IV complications were urinoma (n=2) and no Clavien V complications were noted. Our review suggests that ureteroscopy and laser stone fragmentation for paediatric population is a safe and effective treatment with good SFR and a low risk of complications.

Preparation and Fluorescence Properties of Perylenediimide Nanodispersions Having a One-Dimensional π-Stacked Structure

We prepared stable nanodispersions of a fluorescent perylenediimide (PDI) derivative having long alkyl chains by nanosecond laser fragmentation of its microcrystalline powder in acetonitrile (ACN). The nanoparticles had cube-like or rod shapes with a mean size of 100 nm, and they dispersed stably for longer than 1 month. The prepared nanobricks exhibited absorption and fluorescence spectra characteristic of one-dimensional aggregates with cofacial stacking of PDI planes. Single-particle fluorescence measurements demonstrated that nanobricks had a well-aligned structure of one-dimensional columns of PDI. The aqueous dispersions were also fabricated by redispersing the prepared nanobricks, utilizing lipophilic interactions of surfactants having long alkyl chains. We examined the fluorescence properties of nanoparticles dispersed in ACN and in water, and observed amplified fluorescence quenching by the surface-adsorbed dye.

Ligand-Induced Stability of Gold Nanoclusters: Thiolate versus Selenolate

Thiolate-protected gold nanoclusters have attracted considerable attention as building blocks for new functional materials and have been extensively researched. Some studies have reported that changing the ligand of these gold nanoclusters from thiolate to selenolate increases cluster stability. To confirm this, in this study, we compare the stabilities of precisely synthesized [Au25(SC8H17)18](-) and [Au25(SeC8H17)18](-) against degradation in solution, thermal dissolution, and laser fragmentation. The results demonstrate that changing the ligand from thiolate to selenolate increases cluster stability in reactions involving dissociation of the gold-ligand bond but reduces cluster stability in reactions involving intramolecular dissociation of the ligand. These results reveal that using selenolate ligands makes it possible to produce gold clusters that are more stable against degradation in solution than thiolate-protected gold nanoclusters.