RESUMO
Recently, hybrid halide perovskites have emerged as one of the most promising types of materials for thin-film photovoltaic and light-emitting devices because of their low-cost and potential for high efficiency. Further boosting their performance without detrimentally increasing the complexity of the architecture is critically important for commercialization. Despite a number of plasmonic nanoparticle based designs having been proposed for solar cell improvement, inherent optical losses of the nanoparticles reduce photoluminescence from perovskites. Here we use low-loss high-refractive-index dielectric (silicon) nanoparticles for improving the optical properties of organo-metallic perovskite (MAPbI3) films and metasurfaces to achieve strong enhancement of photoluminescence as well as useful light absorption. As a result, we observed experimentally a 50% enhancement of photoluminescence intensity from a perovskite layer with silicon nanoparticles and 200% enhancement for a nanoimprinted metasurface with silicon nanoparticles on top. Strong increase in light absorption is also demonstrated and described by theoretical calculations. Since both silicon nanoparticle fabrication/deposition and metasurface nanoimprinting techniques are low-cost, we believe that the developed all-dielectric approach paves the way to novel scalable and highly effective designs of perovskite based metadevices.
RESUMO
Surgical interventions were made in 175 patients aged 23-87 years (mean age 64.8 years) with different diseases of the lower urinary tract (adenoma, prostatic cancer, cancer of the urinary bladder, etc.) with application of a new generation of endoscopic technique--transurethral resection in saline (TURis system) with a generator UES-40 SurgMaster (Olympus). Three patients had a cardiac pacemaker. The size of the prostate in prostatic adenoma ranged from 4.8 to 121 cm3 (mean 62.5 cm3), residual urine--92.3 ml (42.6 to 310.2 ml). Duration of surgery averaged 63 min (14 to 127 min). Mean amount of the resected tissue in sclerosis of urinary bladder cervix was 7 g (5-11 g), in prostatic adenoma--41 g (10-85 g), prostatic cancer--27 g (17-49 g). In postoperative period tamponade of the urinary bladder developed in 2 (1.5%) patients. Red cell transfusions were not necessary. Incontinence was observed in 7 (5.3%) patients after removal of urethral catheter, in 5 (3.8%) patients it stopped spontaneously to the time of discharge from the hospital, 2 (1.5%) patients with prostatic cancer retained partial orthostatic incontinence. TURis raised Qmax from 8.1 to 19.8 ml/s, on the average. The scores by IPSS fell from 20.8 to 7.5, QoL--from 5.1 to 3.7, on the average. Residual urine after operation reached 35 ml maximum. Informative value of histological material rose significantly in view of a minimal zone of coagulatory changes in the samples. Standard time limitation for transurethral resection (60-90 min) becomes insignificant in using isotonic irrigation allowing urologists to resect safely larger adenomas than it was possible earlier.
