Split Function Research Articles

Multi-collinear splitting kernels for track function evolution

Jets and their substructure play a central role in many analyses at the Large Hadron Collider (LHC). To improve the precision of measurements, as well as to enable measurement of jet substructure at increasingly small angular scales, tracking information is often used due to its superior angular resolution and robustness to pile-up. Calculations of track-based observables involve non-perturbative track functions, that absorb infrared divergences in perturbative calculations and describe the transition to charged hadrons. The infrared divergences are directly related to the renormalization group evolution (RGE), and can be systematically computed in perturbation theory. Unlike the standard DGLAP evolution, the RGE of the track functions is non-linear, encoding correlations in the fragmentation process. We compute the next-to-leading order (NLO) evolution of the track functions, which involves in its kernel the full 1 → 3 splitting function. We discuss in detail how we implement the evolution equation numerically, and illustrate the size of the NLO corrections. We also show that our equation can be viewed as a master equation for collinear evolution at NLO, by illustrating that by integrating out specific terms, one can derive the evolution for any N -hadron fragmentation function. Our results provide a crucial ingredient for obtaining track-based predictions for generic measurements at the LHC, and for improving the description of the collinear dynamics of jets.

Parenchymal volume analysis to assess longitudinal functional decline following partial nephrectomy.

To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN). Of 1140 patients managed with PN (2012-2014), 349 (31%) had imaging/serum creatinine levels pre-PN, 1-12 months post-PN (new baseline), and >3 years later necessary for inclusion. Parenchymal-volume analysis was used to determine split renal function. Patients were grouped as having significant renal comorbidity (CohortSRC : diabetes mellitus with insulin-dependence or end-organ damage, refractory hypertension, or severe pre-existing chronic kidney disease) vs not having significant renal comorbidity (CohortNoSRC ) preoperatively. Multivariable regression was used to identify predictors of annual ipsilateral parenchymal atrophy and functional decline relative to new baseline values post-PN, after the kidney had healed. The median follow-up was 6.3 years with 87/226/36 patients having cold/warm/zero ischaemia. The median cold/warm ischaemia times were 32/22 min. Overall, the median tumour size was 3.0 cm. The preoperative glomerular filtration rate (GFR) and new baseline GFR (NBGFR) were 81 and 71 mL/min/1.73 m2 , respectively. After establishment of the NBGFR, the median loss of global and ipsilateral function was 0.7 and 0.4 mL/min/1.73 m2 /year, respectively, consistent with the natural ageing process. Overall, the median ipsilateral parenchymal atrophy was 1.2 cm3 /year and accounted for a median of 53% of the annual functional decline. Significant renal comorbidity, age, and warm ischaemia were independently associated with ipsilateral parenchymal atrophy (all P < 0.01). Significant renal comorbidity and ipsilateral parenchymal atrophy were independently associated with annual ipsilateral functional decline (both P < 0.01). Annual median ipsilateral parenchymal atrophy and functional decline were both significantly increased for CohortSRC compared to CohortNoSRC (2.8 vs 0.9 cm3 , P < 0.01 and 0.90 vs 0.30 mL/min/1.73 m2 /year, P < 0.01, respectively). Longitudinal renal function following PN generally follows the normal ageing process. Significant renal comorbidities, age, warm ischaemia, and ipsilateral parenchymal atrophy were the most important predictors of ipsilateral functional decline following establishment of NBGFR.

Non-invasive estimation of split renal function from routine 68Ga-SSR-PET/CT scans.

Patients with impaired kidney function are at elevated risk for nephrotoxicity and hematotoxicity from peptide receptor radionuclide therapy (PPRT) for advanced neuroendocrine tumors. Somatostatin receptor (SSR)-PET/CT imaging is the method of choice to identify sufficient SSR expression as a prerequisite for PRRT. Therefore, our study aimed to explore whether split renal function could be evaluated using imaging data from routine SSR-PET/CT prior to PRRT. In total, 25 consecutive patients who underwent SSR-PET/CT (Siemens Biograph mCT®) before PRRT between June 2019 and December 2020 were enrolled in this retrospective study. PET acquisition in the caudocranial direction started at 20 ± 0.5 min after an i.v. injection of 173 ± 20 MBq [68Ga]Ga-ha DOTATATE, and the kidneys were scanned at 32 ± 0.5 min p.i. The renal parenchyma was segmented semi-automatically using an SUV-based isocontour (SUV between 5 and 15). Multiple parameters including SUVmean of renal parenchyma and blood pool, as well as parenchyma volume, were extracted, and accumulation index (ACI: renal parenchyma volume/SUVmean) and total kidney accumulation (TKA: SUVmean x renal parenchyma volume) were calculated. All data were correlated with the reference standard tubular extraction rate (TER-MAG) from [99mTc]Tc-MAG3 scintigraphy and glomerular filtration rate (GFRCDK - EPI). SUVmean of the parenchymal tracer retention showed a negative correlation with TERMAG (r: -0.519, p < 0.001) and GFRCDK - EPI (r: -0.555, p < 0.001) at 32 min p.i. The herein-introduced ACI revealed a significant correlation (p < 0.05) with the total tubular function (r: 0.482), glomerular renal function (r: 0.461), split renal function (r: 0.916), and absolute single-sided renal function (r: 0.549). The mean difference between the split renal function determined by renal scintigraphy and ACI was 1.8 ± 4.2 % points. This pilot study indicates that static [68Ga]Ga-ha DOTATATE PET-scans at 32 min p.i. may be used to estimate both split renal function and absolute renal function using the herein proposed "Accumulation Index" (ACI).

Equivalent Circuit Models of a Bifunctional Optical Metasurface for Beam Splitting and Refractive Index Sensing

Metasurfaces have attracted extensive attention in the micro/nano-optics field depending on their significant ability to modulate optical parameters. However, the current numerical simulation technology cannot meet the demand of the design and analysis of metasurfaces efficiently due to consuming substantial calculating time and memory. Besides, they cannot illustrate the physical mechanism straightforwardly behind the optical responses. Herein, we propose and demonstrate two equivalent circuit models systematically for a bifunctional metasurface with metal–dielectric–metal structural meta-atoms based on polarization multiplexing in the visible band. In the y-polarization state, the equivalent circuit model is established to interpret the phase shift exactly with a high goodness of fit of 0.931, resulting in the beam splitting function from the anomalous reflection phenomenon. The polychromatic light splits from 34 to 69° to produce the grating-type high-saturation structural colors with a large gamut of about 170.07% of the DCI-P3 standard. In the x-polarization state, the metasurface produces the surface lattice resonance that is suitable for the refractive index sensing function due to the high sensitivity to environmental changes. The second equivalent circuit model simulates the linewidth narrowing and red-shift phenomenon with a sensitivity relative error of 7.00%. We introduce a branch with a narrow-band-pass filter and a capacitor in series into the model to mimic the characteristic of Rayleigh anomalies. Both models extend the application of equivalent circuit theory in optics further and provide a crucial approach to enhance the insights into the mechanism of metasurfaces.

Outcomes of robotic-assisted pyeloplasty in symptomatic versus asymptomatic patients.

To evaluate the outcome of robotic-assisted laparoscopic pyeloplasty (RAP) in symptomatic patients with ureteropelvic junction obstruction (UPJO) versus patients who were incidentally found to have UPJO. We retrospectively reviewed the records of 141 patients who underwent RAP at Massachusetts General Hospital between 2008 and 2020. Patients were categorized into symptomatic group and asymptomatic group. We compared patient demographics as well as preoperative and postoperative symptoms and functional renal scans. The study population included 108 patients in the symptomatic group and 33 patients in the asymptomatic group. Mean age was 46 ± 17years with average follow-up time of 12 ± 18months. Asymptomatic patients had significantly higher rate of definite obstruction (80% versus 70%) and equivocal obstruction (10% versus 0.9%) on preop renogram (P: 0.001). There was no significant difference in the preop split renal function in symptomatic versus asymptomatic group (39 ± 13 versus 36 ± 13 P: 0.3). Following RAP, 91% of symptomatic patients achieved symptom resolution, while four asymptomatic patients (12%) developed new symptoms postoperatively. Compared to preoperative renogram, RAP resulted in improvement in renogram indices in 61% of symptomatic versus 75% of asymptomatic patients (P: 0.2). Although asymptomatic patients had worse obstructive indices on renogram, both symptomatic and asymptomatic groups had comparable improvement in renal function following robotic pyeloplasty. RAP is a safe and efficacious minimally invasive option to offer symptom resolution in symptomatic patients and improve obstruction in both symptomatic and asymptomatic patients with UPJO.

Refining the GENEVA method for Higgs boson production via gluon fusion

We describe a number of improvements to the Geneva method for matching NNLO calculations to parton shower programs. In particular, we detail changes to the resummed calculation used in the matching procedure, including disentangling the cross section dependence on factorisation and beam scales, and an improved treatment of timelike logarithms. We also discuss modifications in the implementation of the splitting functions which serve to make the resummed calculation differential in the higher multiplicity phase space. These changes improve the stability of the numerical cancellation of the nonsingular term at small values of the resolution parameter. As a case study, we consider the gluon-initiated Higgs boson production process gg → H. We validate the NNLO accuracy of our predictions against independent calculations, and compare our showered and hadronised results with recent data taken at the ATLAS and CMS experiments in the diphoton decay channel, finding good agreement.

Four-loop splitting functions in QCD – The quark-quark case

We have computed the even-N moments N≤20 of the pure-singlet quark splitting function Pps at the fourth order of perturbative QCD via the anomalous dimensions of off-shell flavour-singlet operator matrix elements. Our results, derived analytically for a general gauge group, agree with all results obtained for this function so far, in particular with the lowest six even moments obtained via physical cross sections. Using these results and all available endpoint constraints, we construct approximations for Pps at four loops that should be sufficient for most collider-physics applications. Together with the known results for the non-singlet splitting function Pns+ at this order, this effectively completes the quark-quark contribution for the evolution of parton distribution at N3LO accuracy. Our new results thus provide a major step towards fully consistent N3LO calculations at the LHC and the reduction of the residual uncertainty in the parton evolution to the percent level.

Seismic damage prediction of RC buildings using machine learning

AbstractDecision‐makers and stakeholders require a rapid assessment of potential damage after earthquake events in order to develop and implement disaster risk reduction strategies and to respond systematically in post‐disaster situations. The damage investigated manually after an earthquake are complicated, labor‐intensive, time‐consuming, and error prone process. The development of fragility curves is time consuming and unable to predict the damage for wide classes of structures since it considers few structural properties and only one seismic characteristic. Furthermore, the nonlinear finite element method cannot be utilized for numerous buildings because it involves more time and money. This paper presents the machine learning (ML)‐based seismic damage prediction of RC buildings. It is found that some of the research works only considered seismic parameters or structural parameters to train the ML models and predict the structural damage assessment. However, these ML models may not fully reveal the underlying complexity of the relationship between input parameters and building performance. As a result, their applicability will be limited. This paper evaluates the feasibility of using ML techniques such as K‐nearest neighbor, random forest, decision tree, support vector machine, and artificial neural network to rapidly predict earthquake‐induced reinforced concrete building damage considering both the structural properties and ground motion characteristics. The machine learning models are trained using the simulation results. Due to lack of real earthquake damage datasets or limited access, most of the research works used Scikit Learn train_test_split function to randomly split the entire datasets into training and testing datasets and the performance of the proposed ML technique are evaluated using the testing datasets. However, in this study, the performances of different ML models are evaluated using real earthquake damage datasets of RC buildings collected after 2015 Nepal earthquake. The overall accuracy on testing datasets suggests the capability of machine learning algorithms in successfully predicting the seismic damage of reinforced concrete buildings in quick time with reasonable accuracy. This study is beneficial in emergency response and recovery planning after an earthquake.

The First Robotic Day Care Procedure in the Management of Testicular Vein Syndrome: A Rare Cause of Hydroureteronephrosis

Clinical History: A 46-year-old gentleman with no comorbidities presented with dull aching pain in the left loin for 6 months. Physical Examination: Examination was unremarkable. Diagnosis: He was evaluated with contrast-enhanced CT scan of the urinary tract that revealed left gross hydroureteronephrosis secondary to midureteral stricture caused by compression of the left testicular vein. Renogram (diethylenetriamine pentaacetate scan) was performed that showed 44% split renal function of the left kidney with a glomerular filtration rate of 86 mL/min. Intervention: He underwent a day-case robotic ureteroureterostomy and intraoperatively the upper ureter was dilated with testicular vein transposing above the midureter that had a stricture, causing dilatation of proximal ureter with hydronephrosis. Upper ureter was transected above the stricture and brought anterior to the testicular vein and the constricted segment was excised. Ureteroureterostomy was performed over 5F/26 cm Double-J stenting using 2-0 Stratafix suture. Outcomes: Follow-up included stent removal at 6 weeks and serial creatinine thereafter has been normal. Follow-up imaging was done in the form of ultrasonography that showed resolution of hydronephrosis at 3 months and 6 months. Patient Consent Statement: Written informed consent was obtained from the patient to publish this research. No competing financial interests exist.This research received no specific grant from any funding agency, commercial or nonprofit sectors. All authors confirm that they have been involved in the conception and design of the study, drafting of the study for intellectual content, and are accountable to the accuracy of all aspects of the content.Author(s) have received and archived patient consent for video recording/publication in advance of video recording of procedure Runtime of video: 4 mins 17 secs

SIGEST

The SIGEST article in this issue is “Nonlinear Perron--Frobenius Theorems for Nonnegative Tensors,” by Antoine Gautier, Francesco Tudisco, and Matthias Hein. Most computational and applied mathematicians will be aware of the results that Perron published in 1907 about the eigensystems of positive matrices, which were then extended by Frobenius in 1912 to the case of nonnegative matrices. This theory has impacted many areas of mathematics, including graph theory, Markov chains, and matrix computation, and it forms a fundamental component in the analysis of a range of models in areas such as demography, economics, wireless networking, and search engine optimization. Our SIGEST article, which first appeared in SIAM Journal on Matrix Analysis and Applications in 2019, extends Perron--Frobenius theory in two directions. First, the authors generalize from matrices to multidimensional arrays. This ties in with one of SIAM Review's most highly cited offerings: •Tensor decompositions and applications, T. G. Kolda and B. W. Bader, SIAM Review, 51 (3) (2009), pp. 455--500. It may also be viewed as extending the theory from graphs to hypergraphs---objects that are currently of much interest, as evidenced by several recent SIAM Review articles, including •Hypergraph cuts with general splitting functions, N. Veldt, A. R. Benson and J. Kleinberg, SIAM Review, 64 (3) (2022), pp. 650--685. By studying this higher-order setting, the authors open up new applications in network science, computer vision, and machine learning. The second major direction of the article is to develop and study nonlinear versions of the underlying spectral problems, and corresponding extensions of the traditional power method. This makes available new classes of iterations for which a comprehensive and satisfactory convergence theory is available. In preparing this SIGEST version, the authors have included new material. The introduction has been extended, and section 2 has been added to provide nontrivial examples of tensor eigenvalue problems in applications, including problems from computer vision and optimal transport. Moreover, subsection 4.1 includes a new nonlinear Perron--Frobenius theorem (Theorem 4.4) that builds on the previously known results in Theorems 4.2. and 4.3.

Verification of Fuzzy Decision Trees

In recent years, there have been major strides in the safety verification of machine learning models such as neural networks and tree ensembles. However, fuzzy decision trees (FDT), also called soft or differentiable decision trees, are yet unstudied in the context of verification. They present unique verification challenges resulting from multiplications of input values; in the simplest case with a piecewise-linear splitting function, an FDT is piecewise-polynomial with degree up to the depth of the tree. We propose an abstraction-refinement algorithm for verification of properties of FDTs. We show that the problem is NP-Complete, like many other machine learning verification problems, and that our algorithm is complete in a finite precision setting. We benchmark on a selection of public data sets against an off-the-shelf SMT solver and a baseline variation of our algorithm that uses a refinement strategy from similar methods for neural network verification, finding the proposed method to be the fastest. Code for our algorithm along with our experiments and demos are available on GitHub at <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://github.com/autonlab/fdt_verification</uri> .

Three-dimensional Virtual Models of the Kidney with Colored Perfusion Regions: A New Algorithm-based Tool for Optimizing the Clamping Strategy During Robot-assisted Partial Nephrectomy

BackgroundAn empirical selective clamping strategy based on the direction of the arterial branches can lead to failures during partial nephrectomy, even when assisted by three-dimensional virtual models (3DVMs). ObjectiveTo develop and test new 3DVMs that include kidney perfusion regions and evaluate their intraoperative accuracy in guiding selective clamping and their impact on postoperative renal function. Design, setting, and participantsFor patients with a kidney suitable for nephron-sparing surgery, 3DVMs were supplemented with a Voronoi diagram, a Euclidean distance–based mathematical tool, to calculate vascular-dominant regions the kidney. Surgical procedureRobot-assisted partial nephrectomy guided by perfusion-region (PR)-3DVMs. MeasurementsAll anatomic information given by the PR-3DVMs was collected. Selective or superselective clamping was planned and performed intraoperatively when feasible under 3DVM assistance. Changes in split renal function (SRF) and estimated renal plasmatic flow (ERPF) were evaluated for 51 patients who underwent baseline and 3-mo postoperative renal scintigraphy. Results and limitationsA total of 103 patients were prospectively enrolled. The median number of kidney and tumor perfusion regions were 8 (interquartile range [IQR] 7–10) and 3 (IQR 2–3), respectively. A clampless, selective clamping, and global clamping strategy was applied in eight (7.8%), 79 (76.6%), and 16 (15.5%) cases, respectively, with no differences between planning and surgery in terms of the number or order of arteries clamped or the perfusion regions that underwent ischemia. Among the 51 patients who underwent renal scintigraphy, the mean SRF decreased by 11.3%, 7.7%, and 1.7% after global, selective, and superselective clamping, respectively (p = 0.004). Similar results were obtained for ERPF (18.9%, 9.9%, and 6.0%; p = 0.02). The main limitation is the need for a bioengineer to manually refine the 3DVMs. ConclusionsUse of mathematical algorithms for 3DVMs allows precise estimation of kidney perfusion regions to maximize the efficacy of selective clamping and minimize renal function impairment. Patient summaryThree-dimensional models that include regions of blood flow to the kidney can be used to guide clamping of blood vessels when part of the kidney is being surgically removed. More limited clamping can reduce damage to the remaining portion of the kidney and result in better recovery of kidney function after surgery.

The role of warm ischemia time on functional outcomes after robotic partial nephrectomy: a radionuclide renal scan study from the clock randomized trial

PurposeTo evaluate the relationship between warm ischemia time (WIT) duration and renal function after robot-assisted partial nephrectomy (RAPN).MethodsThe CLOCK trial is a phase 3 randomized controlled trial comparing on- vs off-clamp RAPN. All patients underwent pre- and postoperative renal scintigraphy. Six-month absolute variation of eGFR (AV-GFR), rate of relative variation in eGFR over 25% (RV-GFR > 25), absolute variation of split renal function (SRF) at scintigraphy (AV-SRF).The relationships WIT/outcomes were assessed by correlation graphs and then modeled by uni- and multivariable regression.Results324 patients were included (206 on-clamp, 118 off-clamp RAPN). Correlation graphs showed a threshold on WIT equal to 10 min. The differences in outcome measures between cases with WIT < vs ≥ 10 min were: AV-GFR − 3.7 vs − 7.5 ml/min (p < 0.001); AV-SRF − 1% vs − 3.6% (p < 0.001); RV-GFR > 25 9.3% vs 17.8% (p = 0.008). Multivariable models found that AV-GFR was related to WIT ≥ 10 min (regression coefficient [RC] − 0.52, p = 0.019), age (RC − 0.35, p = 0.001) and baseline eGFR (RC − 0.30, p < 0.001); RV-GFR > 25 to WIT ≥ 10 min (odds ratio [OR] 1.11, p = 0.007) and acute kidney injury defined as > 50% increase in serum creatinine (OR 19.7, p = 0.009); AV-SRF to WIT ≥ 10 min (RC − 0.30, p = 0.018), baseline SRF (RC − 0.76, p < 0.001) and RENAL score (RC − 0.60. p = 0.028).The main limitation was that the CLOCK trial was designed on a different endpoint and therefore the present analysis could be underpowered.ConclusionsUp to 10 min WIT had no consequences on functional outcomes. Above the 10-min threshold, a statistically significant, but clinically negligible impact was found.

Point of care parenchymal volume analyses to estimate split renal function and predict functional outcomes after radical nephrectomy

Accurate prediction of new baseline GFR (NBGFR) after radical nephrectomy (RN) can inform clinical management and patient counseling whenever RN is a strong consideration. Preoperative global GFR, split renal function (SRF), and renal functional compensation (RFC) are fundamentally important for the accurate prediction of NBGFR post-RN. While SRF has traditionally been obtained from nuclear renal scans (NRS), differential parenchymal volume analysis (PVA) via software analysis may be more accurate. A simplified approach to estimate parenchymal volumes and SRF based on length/width/height measurements (LWH) has also been proposed. We compare the accuracies of these three methods for determining SRF, and, by extension, predicting NBGFR after RN. All 235 renal cancer patients managed with RN (2006–2021) with available preoperative CT/MRI and NRS, and relevant functional data were analyzed. PVA was performed on CT/MRI using semi-automated software, and LWH measurements were obtained from CT/MRI images. RFC was presumed to be 25%, and thus: Predicted NBGFR = 1.25 × Global GFRPre-RN × SRFContralateral. Predictive accuracies were assessed by mean squared error (MSE) and correlation coefficients (r). The r values for the LWH/NRS/software-derived PVA approaches were 0.72/0.71/0.86, respectively (p < 0.05). The PVA-based approach also had the most favorable MSE, which were 120/126/65, respectively (p < 0.05). Our data show that software-derived PVA provides more accurate and precise SRF estimations and predictions of NBGFR post-RN than NRS/LWH methods. Furthermore, the LWH approach is equivalent to NRS, precluding the need for NRS in most patients.

Ureteropelvic junction obstruction (UPJ) due to congenital crossing of the renal vessels (CRV): Comparison of the pre- and postoperative features of UPJO with and without CRV.

We evaluated the differences in demographic characteristics of patients with and without underlying crossing renal vessels (CRVs) operated for unilateral symptomatic ureteropelvic junction obstruction (UPJO). We identified the features of patients who had undergone open, laparoscopic and robotically assisted laparoscopic pyeloplasty at our institution from July 2000 to January 2021. The ratio of renal parenchymal thickness (RPT; ratio between the kidney with UPJO and the healthy kidney), pelvic diameter and kidney functions were recorded. A total of 641 patients were operated for UPJO; 448 were male (69.8%) and 193 (30.1%) were female; 257 had right-side (40%) and 384 (60%) left-side disease. Fifty-eight patients (9%) were found to have CRV (operated on to treat CRV). The age at diagnosis was 6.51 ± 5.09 years in the CRV (+) group and 1.82 ± 1.37 years in the CRV (-) (p < 0.001). The age at surgery was 8.00 ± 4.71 and 4.27 ± 3.54 years, respectively (p < 0.001). At the time of diagnosis, the RPT measurement was significantly better in CRV (+) compared to CRV (-) group (0.71 ± 0.2 vs. 0.64 ± 0.23, p = 0.043) and initial renal functions were 45.53 ± 8.99% and 42.99 ± 11.65% in CRV (+) and (-) groups respectively. At the time of surgery, the RPTs were 0.60 ± 0.24 and 0.63 ± 0.21 in CRV (+) and (-) groups and these values were also correlated with split renal functions (36.28 ± 15.81% and 41.80 ± 14.26%, respectively). Renal functions were significantly decreased in CRV (+) group (p = 0.027). Significant parenchymal improvements were noted during the first postoperative year. The RPTs were 0.71 ± 0.2 and 0.77 ± 0.19 in the CRV (+) and CRV (-) groups, respectively (p = 0.27) in that time; the improvements continued to increase to postoperative third year (0.74 ± 0.20 and 0.78 ± 0.19 respectively; p = 0.939). In patients with CRVs, renal functions seemed to be preserved in the early stages, however it should be kept in mind that sudden obstruction and loss of kidney function might develop in the follow up period.

Revisiting the double-soft asymptotics of one-loop amplitudes in massless QCD

We evaluate the one-loop soft current for the emission of two soft gluons or a soft quark-anti-quark pair in massless Quantum Chromodynamics. The results are exact in dimensional regularisation up to a single Feynman integral. Two terms of the Taylor series of the latter integral as a function of ϵ ≡ (4 − d)/2 with d the dimension of spacetime are available from a recent calculation of one-loop triple-collinear splitting functions. Our formulae are necessary for the construction of a subtraction scheme for the evaluation of next-to-next-to-next-to-leading order cross sections in massless QCD.

Influence of the excitation polarization on single molecule 3D orientation imaging

Single Molecule Orientation and Localization Microscopy (SMOLM) is gaining an increasing interest in the community of localization microscopy, due to the capability to monitor orientational information in addition to spatial reconstruction. In many cases, molecule’s orientations are not random and their linker to a protein of interest is sufficiently rigid to be able to report orientation information from this protein. While several strategies exist to report single molecule orientation based on polarization splitting and point spread function engineering, the effect of the incident polarization has been often neglected by supposing its effect embedded in the retrieved angular parameters, or by supposing the excitation to be isotropic or the rotational diffusion to be very fast. In this work we quantify the amount of possible bias brought in SMOLM readout due to the incident polarization effect, using analytical derivations. We illustrate this effect experimentally on single molecules attached to a surface in presence of wobbling.

PD43-01 LINEAR MEASUREMENTS AT POINT OF CARE TO ESTIMATE SPLIT RENAL FUNCTION AND PREDICT FUNCTIONAL OUTCOMES AFTER RADICAL NEPHRECTOMY

You have accessJournal of UrologyCME1 Apr 2023PD43-01 LINEAR MEASUREMENTS AT POINT OF CARE TO ESTIMATE SPLIT RENAL FUNCTION AND PREDICT FUNCTIONAL OUTCOMES AFTER RADICAL NEPHRECTOMY Nityam Rathi, Kieran Lewis, Worapat Attawettayanon, Carlos Munoz-Lopez, Yosuke Yasuda, Diego Aguilar Palacios, Jianbo Li, Nour Abdallah, Jared Schober, Marshall Strother, Alexander Kutikov, Robert Uzzo, Christopher Weight, Mohamed Eltemamy, Venkatesh Krishnamurthi, Robert Abouassaly, and Steven Campbell Nityam RathiNityam Rathi More articles by this author , Kieran LewisKieran Lewis More articles by this author , Worapat AttawettayanonWorapat Attawettayanon More articles by this author , Carlos Munoz-LopezCarlos Munoz-Lopez More articles by this author , Yosuke YasudaYosuke Yasuda More articles by this author , Diego Aguilar PalaciosDiego Aguilar Palacios More articles by this author , Jianbo LiJianbo Li More articles by this author , Nour AbdallahNour Abdallah More articles by this author , Jared SchoberJared Schober More articles by this author , Marshall StrotherMarshall Strother More articles by this author , Alexander KutikovAlexander Kutikov More articles by this author , Robert UzzoRobert Uzzo More articles by this author , Christopher WeightChristopher Weight More articles by this author , Mohamed EltemamyMohamed Eltemamy More articles by this author , Venkatesh KrishnamurthiVenkatesh Krishnamurthi More articles by this author , Robert AbouassalyRobert Abouassaly More articles by this author , and Steven CampbellSteven Campbell More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003353.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: While radical nephrectomy (RN) is an important consideration for renal tumors with increased complexity and oncologic potential, reduced postoperative new baseline GFR (NBGFR) relative to partial nephrectomy (PN) remains a concern. Thus, accurate predictions of NBGFR after RN can have clinical implications for RCC management, particularly in challenging cases where RN/PN offer distinct merits. Preoperative global GFR, split renal function (SRF), and renal functional compensation (RFC) in the contralateral kidney have been shown to be fundamental parameters for the accurate prediction of NBGFR after RN. While SRF has traditionally been obtained from nuclear renal scans (NRS), recent studies suggest that software-derived differential parenchymal volume analysis (PVA) is more accurate.1 A simplified approach to estimate SRF based on linear length/width/height measurements (LWH) has also been proposed.2 In this study, we compare the accuracies of each of these three methods for determining SRF, and, by extension, predicting NBGFR. METHODS: All 235 RCC patients managed with RN (2006-21) with preoperative CT/MRI, NRS, and preoperative and postoperative GFR data were included. PVA was performed on CT/MRI using a 3D imaging software (Figure 1A-C), and LWH (Figure 1D-G) measurements were obtained using basic tools in the CT/MRI user interface. NBGFR was defined as the GFR 3-12 months after RN, and RFC was approximated at 25% based on prior studies (Predicted NBGFR=1.25×Global GFRPre-RN×SRFContralateral). Predictive accuracies were assessed by correlation coefficients (r) and mean-squared errors. RESULTS: The r values for the LWH-, NRS-, and PVA-based approaches were 0.72, 0.71, and 0.86, respectively (Figure 1H-J). Differences in predictive accuracies of the PVA-based and non-PVA-based approaches were statistically significant. CONCLUSIONS: Software-derived PVA provides the most precise and accurate estimations of SRF, and thus NBGFR after RN, when compared to NRS and LWH methods. Clinically, the PVA-based approach can readily provide accurate predictions of NBGFR in challenging RCC cases where RN is a relevant consideration. Furthermore, the LWH approach, which can also be performed at point of care, is equivalent to NRS, precluding the need for NRS in most patients. Source of Funding: N/A © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1117 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nityam Rathi More articles by this author Kieran Lewis More articles by this author Worapat Attawettayanon More articles by this author Carlos Munoz-Lopez More articles by this author Yosuke Yasuda More articles by this author Diego Aguilar Palacios More articles by this author Jianbo Li More articles by this author Nour Abdallah More articles by this author Jared Schober More articles by this author Marshall Strother More articles by this author Alexander Kutikov More articles by this author Robert Uzzo More articles by this author Christopher Weight More articles by this author Mohamed Eltemamy More articles by this author Venkatesh Krishnamurthi More articles by this author Robert Abouassaly More articles by this author Steven Campbell More articles by this author Expand All Advertisement PDF downloadLoading ...

MP31-04 PREDICTING NEW BASELINE GLOMERULAR FILTRATION RATE AFTER DONOR NEPHRECTOMY: VALIDATION OF A SPLIT RENAL FUNCTION BASED FORMULA

You have accessJournal of UrologyCME1 Apr 2023MP31-04 PREDICTING NEW BASELINE GLOMERULAR FILTRATION RATE AFTER DONOR NEPHRECTOMY: VALIDATION OF A SPLIT RENAL FUNCTION BASED FORMULA Nicholas Wong, Wei Zheng So, Vineet Gauhar, Benjamin Goh, and Ho Yee Tiong Nicholas WongNicholas Wong More articles by this author , Wei Zheng SoWei Zheng So More articles by this author , Vineet GauharVineet Gauhar More articles by this author , Benjamin GohBenjamin Goh More articles by this author , and Ho Yee TiongHo Yee Tiong More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003264.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Accurate prediction of post donor nephrectomy (DN) glomerular filtration rate is potentially useful for evaluating and counselling of potential living kidney donors. Currently there are limited tools to evaluate the post operative new baseline glomerular filtration rate (NBGFR) in kidney donors. We aim to validate a conceptually simple formula that is based on split renal function (SRF), previously developed for radical nephrectomy (RN) patients (Rathi et al., 2022). METHODS: 83 (mean age 46±12, 44.6% males) consecutive patients who underwent DN (years 2010–2016, 16.9% donated right kidney) with preoperative CT imaging and relevant functional data including baseline Global GFR Pre-DN by CKD-EPI (108.2±13.2mL/min/1.73m2) were included. Observed NBGFR was defined as the latest eGFR 3–12 months post-DN as calculated by CKD-EPI. SRF, defined as volume of the contralateral non-resected kidney normalised by total volume of kidneys, was determined using semi-automated software from preoperative cross-sectional imaging (49.2±2.36%). The equation used was: Predicted NBGFR=1.24 x (Global GFR Pre-DN) x (SRF). Alignment between predicted NBGFR (66.0±8.29mL/min/1.73m2) and observed NBGFR (74.9±16.4mL/min/1.73m2) was assessed by evaluating correlation coefficients, bias, precision, accuracy, concordance and also utilised a Bland-Altman plot to evaluate agreement. RESULTS: The new SRF-based formula for NBGFR prediction correlated strongly with post operative NBGFR (Pearson’s r=0.729, Figure 1) and showed minimal bias (median difference = 7.190mL/min/1.73m2) with good accuracy (96.4% within±30%, 62.7% within±15%) and precision (IQR of bias = -0.094-16.227). The formula tended to underestimate NBGFR values at lower observed NBGFR values and overestimate at higher values. The SRF based formula was also able to accurately discriminate all but one of our patients to a NBGFR of >45ml/min/1.73m2, an NBGFR threshold associated with a reduced risk of renal function deterioration (Campbell et al., 2021). CONCLUSIONS: The newly developed SRF-based formula for predicting NBGFR is validated in a living kidney donor population. This gives clinicians an insight into post operative renal function, granting them better ability to prognosticate, educate and pre-empt DN patients. Source of Funding: There are no sources of funding © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e430 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nicholas Wong More articles by this author Wei Zheng So More articles by this author Vineet Gauhar More articles by this author Benjamin Goh More articles by this author Ho Yee Tiong More articles by this author Expand All Advertisement PDF downloadLoading ...

MP31-02 IN THE ERA OF COMPUTED TOMOGRAPHY VOLUMETRY: IS ISOTOPE RENOGRAPHY STILL ROUTINELY REQUIRED IN THE PREPARATION AND SELECTION OF LIVING KIDNEY DONORS?

You have accessJournal of UrologyCME1 Apr 2023MP31-02 IN THE ERA OF COMPUTED TOMOGRAPHY VOLUMETRY: IS ISOTOPE RENOGRAPHY STILL ROUTINELY REQUIRED IN THE PREPARATION AND SELECTION OF LIVING KIDNEY DONORS? Bedeir Ali-El-Dein, Ahmed Galal, Mohamed Zahran, Huda Refaie, Mohamed E Mashaly, Mohamed T Fouad, Ayman F. Refaie, Ibrahim Saeed, Mohamed Atteya, and Yasser M Osman Bedeir Ali-El-DeinBedeir Ali-El-Dein More articles by this author , Ahmed GalalAhmed Galal More articles by this author , Mohamed ZahranMohamed Zahran More articles by this author , Huda RefaieHuda Refaie More articles by this author , Mohamed E MashalyMohamed E Mashaly More articles by this author , Mohamed T FouadMohamed T Fouad More articles by this author , Ayman F. RefaieAyman F. Refaie More articles by this author , Ibrahim SaeedIbrahim Saeed More articles by this author , Mohamed AtteyaMohamed Atteya More articles by this author , and Yasser M OsmanYasser M Osman More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003264.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Side selection in living kidney donors (LKD) before renal transplantation (RT) depends mainly on the split-renal function (SRF) assessed by isotope renography and structural anatomy of the kidney determined by computed tomography angiography (CTA). If we can use a single modality to assess both, we can reduce time and cost. The objective is to compare the CT-split renal volume (CT-SRV) to the SRF derived from DTPA Renography with regard to the decision of donor side selection. METHODS: The study was performed between July 2017 and July 2020. In potential donors, renal volume was measured using computer generated volumetric scanning system. CT-SRV was estimated by dividing one kidney volume by the volume of both. Similarly, SRF was estimated by glomerular filtration rate (GFR) on renogram. Donor side selection was made by multi-disciplinary team. After complete evaluation, donor side selection was determined by CT alone (SRV and vascular anatomy). Then, renogram was shown and selection made by CT alone was compared to that based on CT and renogram. RESULTS: 258 consecutive donors (94 males and 164 females; mean age 42±9.7 years) were included. SRF and SRV were comparable in 177 (Rt) & 172 (Lt) cases. Using CT alone, the right and left kidney were chosen in 91 and 167. Using CT and renogram, 83 and 175 right and left kidneys were selected with mean GFR of 55.2±8.9 ml/min and CT volume 156±28 mL. The choice of the donor side based on CT alone was in agreement with the choice based on both CT and renogram in 237 (92%), with a difference in choice in 21 cases (8%) (Table 1). Subset analysis of these 21 cases showed that 15 had multiple vessels, small cysts and/ or gravels and all had a significant disparity (>5.3%) on CT volumetry. CONCLUSIONS: Regarding donor side selection, CT volumetry has high concordance (>90%) with isotope renography. It is, therefore, considered a sufficient pre-transplant single diagnostic tool for this purpose. However, if significant disparity in SRV is diagnosed by CT or in the cases with multiple vessels, cysts and/ or gravels, complete evaluation using both CT and isotope renography should be conducted. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e429 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bedeir Ali-El-Dein More articles by this author Ahmed Galal More articles by this author Mohamed Zahran More articles by this author Huda Refaie More articles by this author Mohamed E Mashaly More articles by this author Mohamed T Fouad More articles by this author Ayman F. Refaie More articles by this author Ibrahim Saeed More articles by this author Mohamed Atteya More articles by this author Yasser M Osman More articles by this author Expand All Advertisement PDF downloadLoading ...