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Abstract: This research focuses on acquiring accurate flow boiling heat transfer data and flow pattern visualization for three refrigerants, R134a, R236fa and R245fa in a 1.030mm channel. We investigate trends in the data, and their possible mechanisms, for mass fluxes from 200 to 1600kg/m2s, heat fluxes from 2.3kW/m2 to 250kW/m2 at T sat =31°C and ΔT sub from 2 to 9K. The local saturated flow boiling heat transfer coefficients display a heat flux and a mass flux dependency but no residual subcooling influence. The changes in heat transfer trends correspond well with flow regime transitions. These were segregated into the isolated bubble (IB) regime, the coalescing bubble (CB) regime, and the annular (A) regime for the three fluids. The importance of nucleate boiling and forced convection in these small channels is still relatively unclear and requires further research. [Copyright &y& Elsevier]

Abstract: Objectives: Intraoperative oliguria and its impact on early postoperative allograft function have been expressed as potential concerns of laparoscopic kidney donation. We evaluated our ability to maintain adequate diuresis during laparoscopic donor nephrectomy and its potential impact on early graft function compared with open donation. Methods: We performed a retrospective review of 98 laparoscopic and 80 open donor nephrectomies from 1999 to 2002. All laparoscopic donors received infusions of mannitol (grams of mannitol equaled patient weight in kilograms) and dopamine (2 to 3.0 μg/kg/min) throughout the pneumoperitoneum. All open donors received a single dose of mannitol (12.5 g). Multiple donor variables were compared, including operative time, estimated blood loss, intraoperative fluid administration (in milliliters per kilogram per hour), intraoperative urine production (milliliters per kilogram per hour), and change in creatinine at discharge. The postoperative recipient data were compared, including initial 24-hour urine output, 1-week creatinine level, 1-month creatinine level, and need for postoperative hemodialysis. Results: No significant differences were noted in the donor groups with respect to age, weight, intraoperative fluid administration, or change in creatinine at discharge. The mean operative urine production was greater in the laparoscopic group at 5.22 mL/kg/hr than in the open group at 2.43 mL/kg/hr (P = 0.0001). The mean estimated blood loss was significantly lower (P = 0.0001) for the laparoscopic donors (106.7 mL) than for the open donors (184.7 mL). No significant differences were seen among the recipient groups. Conclusions: The use of mannitol and dopamine infusions during laparoscopic donor nephrectomy provided superior intraoperative urine production in the donor and equivalent early graft function in the recipient compared with the open approach. [Copyright &y& Elsevier]

Intrafraction motion affects tumor position during radiation for head and neck cancers (HNC) and can be assessed using magnetic resonance cine (MR-cine). Heatmaps – visual representation of patient specific temporal tumor location akin to internal target volume (ITV) - were analyzed to demonstrate the variation of population-based motion margins in primary oropharyngeal (OP) and laryngeal/hypopharyngeal (LH) sites with the goal to provide insights towards personalized margins. MR-cine were performed for LH and OP HNC patients as part of simulation protocol. Images (900-1500 slices) were acquired across 3-5 minutes per patient. Gross target volumes were propagated on T1 contrast sagittal sequence using deformable image registration then adjusted manually. Tumor locations were integrated across all frames and displayed as heatmaps representing location probability. To determine individualized motion, a baseline contour representing average tumor rest position was expanded both isotropically and directionally in 1 mm increments in a novel analysis to define the contribution of each increment on target coverage. To assess directional dependence, displacements from rest position were evaluated in 4 planes from centroid: (A) 12 o'clock (OC) to 6OC (capturing volumetric shift in a portion of superior, posterior and inferior directions), B) 3OC-9OC, C) 6OC-12OC, D) 9OC-3OC. Histograms demonstrating the proportion of scan time the tumor was within expansions were generated, with expansion margins for 25%-95% coverage analyzed by patient. Wilcoxon-rank-sum test was performed to compare motion by site. Motion was evaluated in 66 patients (LH n = 27, OP n = 39). In LH, a median (med) isometric expansion of 8.5mm to achieve 95% target was required, with large variations observed for minimum (min): 2.8mm and maximum (max):23.5mm. Smaller differences were observed for OP with med of 5.3mm, (min:1.9mm, max:14.6mm). At 75%, 50% and 25% coverage, expansions for LH (med: 4.8 min: 1.9 max: 17.3; med: 3.8 min: 1.2 max: 12.9; med: 3.3, min: 0.6, max: 9.3) were not significantly different than OP (med: 3.8, min: 1.7, max: 10.9; med: 3.1 min: 1.3, max: 9.4; med: 2.1, min: 0.7, max: 8.4), suggesting larger but infrequent shifts in LH. Directional tumor displacement varied widely (Table 1), and by site and points describing the need for personalized margins. Current literature as well as the analysis in this study indicate a wide range of motion – both in magnitude and duty cycle – between and within HN sub-sites not captured on CT simulation. Moving forward, motion based heatmaps based on MR-cine may serve as visualization tool for ITV contouring or to generate personalized motion margins. [ABSTRACT FROM AUTHOR]

Background: It is unclear whether the Ross procedure offers superior survival compared with mechanical aortic valve replacement (AVR).Objectives: This study evaluated experience and compared long-term survival between the Ross procedure and mechanical AVR.Methods: Between 1992 and 2016, a total of 392 Ross procedures were performed. These were compared with 1,928 isolated mechanical AVRs performed during the same time period as identified using the University of Melbourne and Australia and New Zealand Society of Cardiac and Thoracic Surgeons' Cardiac Surgery Databases. Only patients between 18 and 65 years of age were included. Propensity-score matching was performed for risk adjustment.Results: Ross procedure patients were younger, and had fewer cardiovascular risk factors. The Ross procedure was associated with longer cardiopulmonary bypass and aortic cross-clamp times. Thirty-day mortality was similar (Ross, 0.3%; mechanical, 0.8%; p = 0.5). Ross procedure patients experienced superior unadjusted long-term survival at 20 years (Ross, 95%; mechanical, 68%; p < 0.001). Multivariable analysis showed the Ross procedure to be associated with a reduced risk of late mortality (hazard ratio: 0.34; 95% confidence internal: 0.17 to 0.67; p < 0.001). Among 275 propensity-score matched pairs, Ross procedure patients had superior survival at 20 years (Ross, 94%; mechanical, 84%; p = 0.018).Conclusions: In this Australian, propensity-score matched study, the Ross procedure was associated with better long-term survival compared with mechanical AVR. In younger patients, with a long life expectancy, the Ross procedure should be considered in centers with sufficient expertise. [ABSTRACT FROM AUTHOR]

To report clinical outcomes for patients with metastatic disease to the head and neck (HN) treated with stereotactic body radiation therapy (SBRT) at a large academic center. A retrospective review of SBRT patients treated to the HN from 2012 to 2020 was conducted. Treatment indications included: oligometastases, oligoprogression, and local control of a dominant area of progression (DAP). Kaplan-Meier method was used to estimate local control (LC), regional control (RC), overall survival (OS), and progression-free survival (PFS). Univariable (UVA) and multivariable analyses (MVA) were performed to determine the relationship between clinical characteristics and outcomes. Grade 3—4 acute and late toxicities were reported by the Common Terminology Criteria for Adverse Events v5.0. Fifty-six patients (58 lesions) were analyzed with a median follow-up of 16 months. Primary cancer sites included lung (25%), kidney (19.6%), breast (19.6%) and other (35.8%). SBRT indications were: oligometastases (n = 24, 42.9%), oligoprogression (n = 11, 19.6%), and local control of a DAP (n = 21, 37.5%). Most patients received SBRT to a single neck node (n = 48, 82.8%). Median SBRT dose was 40 Gy (range: 25-50 Gy) in 5 fractions, with a median biologically effective dose (BED 10) of 72 Gy (range: 37.5-100 Gy). One- and 2-year LC rates were 97.6% and 72.7%. One- and 2-year RC rates were 100% and 86.7%, respectively. Median OS was 19.2 months (95% confidence interval [CI], 14.8-69.4) and median PFS was 7.4 months (95% CI, 5.2-11.9). The 1-year OS and PFS rates for oligometastases, oligoprogression and DAP were 95.8%, 63.6% and 38.1% (p = 0.0039), and 56.5%, 27.3% and 19.1% (p = 0.0004), respectively. On MVA, treatment indication and histology were found to be predictive for OS and treatment indication and prior systemic therapy were the predictive factors for PFS. Ten patients (18%) developed acute grade ≥ 3 treatment-related toxicity and six patients (11%) experienced late grade ≥ 3 toxicity. The use of SBRT for metastatic disease to the HN provided excellent LC rates with low rates of regional failure. Patients with oligometastatic disease had better OS and PFS than others. This treatment resulted in an acceptable toxicity profile. [ABSTRACT FROM AUTHOR]

Abstract: High-mobility group box 1 protein (HMGB1) has cytokine activities and mediates systemic inflammation as well as immune responses. The aim of this study was to determine if plasma HMGB1 level can be used as a marker for neuromyelitis optica (NMO) and to differentiate NMO from multiple sclerosis (MS). We measured plasma levels of HMGB1, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin 17 (IL-17) in 29 patients with NMO and 20 patients with MS at enrollment and at 2years follow-up (at the time of definitive diagnosis) by enzyme-linked immunosorbent assay. Plasma HMGB1 level was significantly greater in the NMO group compared to the MS group (P <0.001). Plasma levels of TNF-α, IFN-γ, and IL-17 were significantly greater in the NMO group compared to the MS group, and HMGB1 level was positively correlated with TNF-α, IFN-γ, and IL-17 levels. Univariate logistic regression analysis showed a significant association of HMGB1 level, and IFN-γ level with NMO diagnosis. Although this study included a limited sample size, we attempted to determine an optimized cutoff point for HMGB1 (⩾2ng/ml), which provided 89.7% sensitivity and 95.0% specificity for the diagnosis of NMO. These results indicate that plasma HMGB1 level might serve as a surrogate marker for NMO disease activity and aid in the differentiation of NMO from MS at the early disease stage. [Copyright &y& Elsevier]