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Abstract Background To analyze our initial results of hand-assisted laparoscopic living donor nephrectomy, executed by a skilled gastrointestinal surgeon. Methods A total of 22 consecutive patients underwent the hand-assisted laparoscopic living donor nephrectomy between December 2014 and January 2017. We retrospectively analyze the patient's perioperative clinical data, which were collected prospectively. Results The right kidney was harvested in 12 patients. The mean operative time and intraoperative blood loss was 241.0 ± 43.4 minutes (range, 140–310 min) and 293.2 ± 203.1 mL (range, 50–700 mL), respectively. The mean warm ischemic time was 288.4 ± 103.4 seconds (range, 179–610 s). Postoperative complications included chyle leakage in 2 patients who were left kidney donors and oliguria in 1 patient who was a right kidney donor. All patients recovered with conservative care, and the mean hospital stay was 7.5 ± 1.7 days. The mean creatinine level was 0.7 ± 0.2 mg/dL before surgery, 1.1 ± 0.3 mg/dL at postoperative day (POD) 1, and 1.0 ± 0.2 mg/dL after discharge. The mean glomerular filtration rate was 97.9 ± 18.2 mL/min/1.73 m2 before surgery, 60.7 ± 10.4 at POD 1, and 67.3 ± 11.1 after discharge. Operation time was not associated with patient body mass index and case number. No significant differences, other than postoperative complications, were found in the perioperative data for the side of kidney donation. Conclusion A skilled surgeon with experience in laparoscopic abdominal surgery (such as gastrectomy or colectomy) might safely perform hand-assisted donor nephrectomy. However, we could not identify a clear case number to complete the learning curve. Highlights • Left donor nephrectomy requires longer operation time than the right side: 247.7 ± 28.1 minutes vs 235.8 ± 53.7 minutes. • The mean blood loss was 293.2 ± 203.1 mL, and the mean warm ischemic time was 288.4 ± 103.4 seconds. • There are 3 morbidities (1 oliguria and 2 chyle leakages) in 22 total cases. • There was no correlation between operation time and body mass index. • After 10 cases of donor nephrectomy, operation time and warm ischemic time were decreased significantly. [ABSTRACT FROM AUTHOR]

Regulation of the phosphorous (P) concentration in effluent from the Jinju wastewater treatment plant (WWTP) in southern part of Korea has recently been strengthened, with a reduction in the acceptable P limit from 2.0 to 0.2 mg/L. Various treatment processes have been introduced and applied to meet the regulation, after use of biological treatments such as conventional activated sludge, anoxic–oxic (A/O), and anaerobic–anoxic–oxic (A2/O) treatments. The present work introduces a hybrid system of A2/O and dissolved air flotation (DAF) treatment to remove P from the effluent. The total capacity of the WWTP is 190,000 m3/d. The dimensions of the DAF basins are 8 m (width), 16 m (length), 4.2 m (height), 6 basins, and the capacity is 2,995 m3/d. The retention time and recycling ratio are 19 min and 15%, respectively. The surface loading rate is 240 m/d. Operation of the system with A2/O+DAF has already commenced and total P was reduced from 2.18 to 0.03 mg/L. A2/O+DAF treatment improved the mean effluent concentrations of total phosphorus, chemical oxygen demand, and suspended solids by approximately 70, 29, and 27%, respectively, compared with the corresponding levels in effluent after A2/O treatment alone. [ABSTRACT FROM PUBLISHER]

Abstract: In this paper, sandwich structures for micro-EDM machines are optimized by using parametric study varying composite geometries and parameters like stacking sequence, thickness and rib geometry. The structures are composed of fibre reinforced composites for skin material and resin concrete and PVC foam (Closed cell, Divinycell) for core materials. Column structure was designed by a beam with cruciform rib and performance indices such as static bending stiffness (EI) and specific bending stiffness (EI/ρ) for dynamic stability are examined by controlling the thickness and stacking sequence of composites. For the machine tool bed, which usually has a plate shape, was designed to have high stiffness in two directions at the same time controlling stacking sequence and rib geometry; that is, rib thickness and number of ribs. The sensitivity of design parameters like rib thickness and composite skin thickness was examined and the optimal condition for high stiffness structure was suggested. Finite element analysis was also performed to verify the static and dynamic robustness of the machine structure. L-shaped joint for combining bed and column of the micro-EDM machine was proposed and fabricated using adhesive bonding. The dynamic performance such as damping characteristics was investigated by vibration tests. From the results optimal configuration and materials for high precision micro-EDM machines are proposed. [Copyright &y& Elsevier]

The purpose of this study was to examine the efficacy of a chemotherapeutic drug, doxorubicin (DOX), loaded in pH-sensitive micelles poly(l-histidine) ( M n :5K)- b -PEG ( M n :5K) micelles. The micelles were designed to target the acidic extracellular pH of solid tumors. Studies of pH-dependent cytotoxicity, growth rate of the tumor, pharmacokinetics and biodistribution were conducted. In vitro DOX uptake upon A2780 cells by incubating the cells in a pH 6.8 complete medium at a concentration of 20 μg DOX/ml in the micelle formulation was more than five times that of pH 7.4 condition for initial 20 min. In vivo pharmacokinetic data showed that AUC (area under concentration curve) and half life time ( t 1/2 ) (plasma half life) of DOX in the pH sensitive micelles increased about 5.8- and 5.2-fold of free DOX in phosphate buffered saline (PBS), respectively. It appeared that DOX in the pH-sensitive micelles preferentially accumulated in the tumor site. The distributions at 12 h post injection in other organs including liver, kidney, spleen, lung and heart were not significantly different from those of DOX in PBS at a 6 mg DOX/kg dose. The in vivo test of anti-tumor activity was performed with human ovarian carcinoma A2780 which was subcutaneously xenografted in female nu / nu athymic mice. The pH-sensitive micelle formulation significantly retarded tumor growth rate without serious body weight loss. The triggered drug release by the reduced tumor pH is believed to be a major mechanism of the observed efficacy after passive accumulation of the micelles by EPR effect. This may have resulted in a local high dose of drug in the tested solid tumor. [ABSTRACT FROM AUTHOR]

An all-digital closed-loop (ADCL) signal processor is developed for optically open-loop fiber-optic gyroscope. The processor is designed to provide high performance of more than 30 bits of phase resolution over 2π and unlimited measurement range. The random walk of the processor was measured to be about 0.57 μrad/Hz1/2 [ABSTRACT FROM PUBLISHER]

This paper presents operational data and parameters of the newest generation of polyphase resonant high voltage converter modulator (HVCM) as developed and delivered to the KAERI 100 MeV "PEFP" accelerator. The KAERI design realizes improvements from the SNS and SLAC designs. The present KAERI system operates two parallel THALES TH2089F 350 MHz klystrons with total power draw of 50 amperes at 105 kV. An additional 3 klystron system operating at 105 kV and 75 A is also being considered for the high energy sections of this accelerator. In these systems, to improve the IGBT switching performance, the HVCMs will be fitted with artificial zero-voltage-switching (ZVS) networks at turn-off. This new method of artificial ZVS should result in a 6 fold reduction of IGBT switching losses. This will improve the HCVM conversion efficiency to better than 95% at full average power, which is 500 kW for the 2 klystron system and 750 kW for the 3 klystron system. The artificial ZVS is accomplished by placing a soft switching capacitor network across the resonant boost transformer primary winding. This low loss snubber circuit reduces the dv/dt across the IGBTs at turn-off. As the transformer input busswork is extremely low inductance (<10 nH), the single network acts like it is across each IGBT collector-emitter terminal of the 4 transistor H-bridge switching network. We will review these topological improvements and the overall system as delivered to the KAERI accelerator with details of the installed operational results. [ABSTRACT FROM AUTHOR]

Abstract: Seawater desalination of interest is rising to overcome water scarcity. Especially, desalination using RO membranes is increasingly being used for production of drinking water for brackish and/or seawater. SWRO has operational problems that can be caused by various membranes fouling including particulate, inorganic, organic and bio-fouling. Membrane-based pretreatment for particle fouling and the integrated membrane systems with MF, NF, and RO were recently introduced to SWRO. However, little information is known for SWRO processes combined with various pretreatments. Eff ects of various pretreatments on performance of SWRO were evaluated in this study. The RO membrane flux was substantially improved by nanofi ltration pretreatment resulting in the highest flux regardless of pretreatment for particle fouling. However, the water flux with the other pretreatments including MF with antiscalant addition is severely decreased during a few hours. The microfi ltration pretreatment showed greater flux than the coagulation pretreated water. Coagulation pretreated waters was observed to have relatively high MFI resulting from residuals such as flocs and colloidal particles. The correlations of turbidity, normalized flux ratio and MFI were substantial indicating feasibility of the use of MFI for particle fouling index. The conductivity removal was signifi cant, but the cation removal was not great by NF. The results of the inorganic ions removal indicate that pretreatment process aff ects properties of feed water to RO. The application of inorganic scaling control pretreatment has shown no influence on the crystal structure but there were changes in the intensity related with calcium scale inhibition in the XRD analyses. [Copyright &y& Elsevier]