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Tunable metasurfaces for visible and SWIR applications

Lee CW, Choi HJ, Jeong H

Nano Converg, 2020 Jan 20;7(1):3.
PMID: 31956942 DOI: 10.1186/s40580-019-0213-2

Demand on optical or photonic applications in the visible or short-wavelength infrared (SWIR) spectra, such as vision, virtual or augmented displays, imaging, spectroscopy, remote sensing (LIDAR), chemical reaction sensing, microscopy, and photonic integrated circuits, has envisaged new type of subwavelength-featured materials and devices for controlling electromagnetic waves. The study on metasurfaces, of which the thickness is either comparable to or smaller than the wavelength of the considered incoming electromagnetic wave, has been grown rapidly to embrace the needs of developing sub 100-micron active photonic pixelated devices and their arrayed form. Meta-atoms in metasurfaces are now actively controlled under external stimuli to lead to a large phase shift upon the incident light, which has provided a huge potential for arrayed two-dimensional active optics. This short review summarizes actively tunable or reconfigurable metasurfaces for the visible or SWIR spectra, to account for the physical operating principles and the current issues to overcome.
Is metal nanofluid reliable as heat carrier?

Nine MJ, Chung H, Tanshen MR, Osman NA, Jeong H

J Hazard Mater, 2014 May 30;273:183-91.
PMID: 24735805 DOI: 10.1016/j.jhazmat.2014.03.055

A pre- and post experimental analysis of copper-water and silver-water nanofluids are conducted to investigate minimal changes in quality of nanofluids before and after an effective heat transfer. A single loop oscillating heat pipe (OHP) having inner diameter of 2.4mm is charged with aforementioned nanofluids at 60% filling ratio for end to end heat transfer. Post experimental analysis of both nanofluids raises questions to the physical, chemical and thermal stability of such suspension for hazardless uses in the field of heat transfer. The color, deposition, dispersibility, propensity to be oxidized, disintegration, agglomeration and thermal conductivity of metal nanofluids are found to be strictly affected by heat transfer process and vice versa. Such degradation in quality of basic properties of metal nanofluids implies its challenges in practical application even for short-term heat transfer operations at oxidative environment as nano-sized metal particles are chemically more unstable than its bulk material. The use of the solid/liquid suspension containing metal nanoparticles in any heat exchanger as heat carrier might be detrimental to the whole system.
IAEA Activities on 67Cu, 186Re, 47Sc Theranostic Radionuclides and Radiopharmaceuticals

Jalilian AR, Gizawy MA, Alliot C, Takacs S, Chakarborty S, Rovais MRA, et al.

Curr Radiopharm, 2021;14(4):306-314.
PMID: 32988359 DOI: 10.2174/1874471013999200928162322

Despite interesting properties, the use of 67Cu, 186Re and 47Sc theranostic radionuclides in preclinical studies and clinical trials is curtailed by their limited availability due to a lack of widely established production methods. An IAEA Coordinated Research Project (CRP) was initiated to identify important technical issues related to the production and quality control of these emerging radionuclides and related radiopharmaceuticals, based on the request from IAEA Member States. The international team worked on targetry, separation, quality control and radiopharmaceutical aspects of the radionuclides obtained from research reactors and cyclotrons leading to preparation of a standard recommendations for all Member States. The CRP was initiated in 2016 with fourteen participants from thirteen Member States from four continents. Extraordinary results on the production, quality control and preclinical evaluation of selected radionuclides were reported in this project that was finalized in 2020. The outcomes, outputs and results of this project achieved by participating Member States are described in this minireview.
Comparison of the Efficacy and Safety of Laparoendoscopic Single-Site Surgery with Conventional Laparoscopic Surgery for Upper Ureter or Renal Pelvis Stones in a Single Institution: A Randomized Controlled Study

Park J, Lee SB, Cho SY, Jeong CW, Son H, Park YH, et al.

Urol J, 2016 Aug 25;13(4):2759-64.
PMID: 27576882

PURPOSE: To evaluate the utility and safety of laparoendoscopic single-site surgery (LESS) in comparison with conventional laparoscopic (CL) surgery for the treatment of upper urinary tract stones.
MATERIAL AND METHODS: Between June 2011 and May 2012, 20 patients with upper urinary tract stones were included in this prospective randomized study. The patients were assigned into the LESS group or CL group in a one-on-one manner using a random table. The clinical parameters were evaluated in the immediate postoperative period, and the stone clearance rate was evaluated via non-contrast computer tomography at one month postoperatively.
RESULTS: There were no significant differences in patient demographics or preoperative stone sizes between the two groups. The perioperative parameters, including operative time, estimated blood loss, postoperative pain scores, length of hospital stay, and changes in renal function, were comparable. No transfusions or open conversions were required in either group. The incidence of residual stones was lower in the LESS group (1 case) than in the CL group (2 cases). However, this difference was not statistically significant.
CONCLUSIONS: For large and impacted upper ureteral stones, the effectiveness and safety of LESS were equivalent to those of CL. Further randomized control trials with larger sample sizes are needed to strengthen the conclusions of this study.&nbsp.