bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction and quantification of bioclogging depth limit and rate based on numerical simulation and experimental validation in managed aquifer recharge
Authors: Ye Xueyan , Ma Xiaofeng , Du Xinqiang , Cui Ruijuan , Wan Yuyu 
Published: October 2022

AbstractMany microorganisms are naturally occurring in both recharging water and porous media, and microorganisms will grow and clog the pores of porous media. Porous media show different clogging depth and rate, which depends on the carbon source concentration. The bioclogging depth limit and rate under the effect of the nutrient concentration can be disentangled through column experiments and numerical simulation approaches. We use the TOUGHREACT method‐based on the monod equation of microbial growth to explore the process of microbial growth and permeability change, and correct with experimental results. The experimental results show the influence of nutrient concentration (glucose) on microbial growth and clogging of porous medium, and leads to clogging of porous medium. The clogging rate was defined as the rate of change of hydraulic conductivity with time for quantitative study of bioclogging in our study. Simulated results found that the clogging rate increases 0.035 and 0.00673 (m/d/min) respectively in the glucose concentration range of 0.045–0.6 and 0.6–5 mmol/L, simultaneously, the ultimate clogging depth decreases 18.2 and 1.7 mm respectively in the glucose concentration range of 0.045–0.6 and 0.6–5 mmol/L. The aim of this study was to evaluate the effects of nutrient concentrations on bioclogging and shed light on the establishment of nutrient concentration standards for recharge water during groundwater artificial recharge.
Suspended sediment load estimation in a severely eroded and data poor catchment
Authors: Bannatyne Laura J. , Foster Ian D.L. , Rowntree Kate M. , van der Waal Bennie W. 
Published: October 2022

AbstractSoil erosion rates are high in many parts of Southern Africa, and are likely to rise because of climate change. Suspended sediment loads (SSL) and yields (SSY) are used to measure and benchmark soil erosion and/or sediment transport rates and determine trajectories of change. Some modelled SSY are available for Southern African catchments, but there is a dearth of contemporary observed data. Northern hemisphere approaches to suspended sediment measurement and the calculation of loads and yields are often unsuited to Southern Africa: locally appropriate methods are required. The manual, flood‐focused suspended sediment sampling programme that we implemented in the eroded and data‐scarce Tsitsa River catchment (Eastern Cape, South Africa) monitored four sub‐catchments from December 2015 to June 2019 at a sub‐daily timestep. We used a discharge‐weighted interpolation SSL estimator, investigating the effects of catchment area, hydrological regime, and sampling strategy on SSL, SSY, and variability, comparing our estimates with modelled results. Discharge increased with catchment area whilst flashiness (expressed by the Richards‐Baker Flashiness Index) mainly decreased, and was similar to that of North American catchments. The sampling frequency required to maintain precision was inversely related to catchment area. Mean annual SSL ranged from 18 121 t year−1 in the 204 km2 Gqukunqa River catchment to 984 267 t year−1 in the 1452 km2 Inxu River catchment. Mean annual SSY ranged from 61 t km2 year−1 in the 432 km2 Pot River catchment to 678 t km2 year−1 in the Inxu River catchment. Data stratification to limit sampling to wet‐season flows did not significantly impact SSL estimates, but year‐round sampling is required to maintain the citizen‐technician sampling network through regular income. Modelled SSY estimates were higher than our measured estimates. Our approach to suspended sediment sampling, load and yield estimation is robust, sustainable, precise, and can be adapted for similar, remote catchments.
Population Pharmacokinetics of Tacrolimus in Pediatric Patients With Umbilical Cord Blood Transplant
Authors: Zuo Meiling , Shang Yue , Guo Ye , Sun Yuxuan , Xu Gaoqi , Chen Jingtao , Zhu Liqin 
Published: October 2022

AbstractTacrolimus was frequently used in pediatric patients with umbilical cord blood transplant for the prevention of graft‐versus‐host disease. The aim of the present study was to evaluate the population pharmacokinetics of tacrolimus among pediatric patients with umbilical cord blood transplant and find potential influenced factors. A total of 275 concentrations from 13 pediatric patients were used to build a polulation pharmacokinetic model using a nonlinear mixed‐effects modeling approach. The impact of demographic features, biological characteristics, and concomitant medications, including sex, age, body weight, postoperative day, white blood cell count, red blood cell count, hemoglobin, platelets, hematocrit, blood urea nitrogen, creatinine, aspartate transaminase, alanine transaminase, total bilirubin, albumin, and total protein were investigated. The pharmacokinetics of tacrolimus were best described by a 1‐compartment model with first‐ and zero‐order mixed absorption and first‐order elimination. The clearance and volume of distribution of tacrolimus were 1.93 L/h and 75.1 L, respectively. A covariate analysis identified that postoperative day and co‑administration with trimethoprim‐sulfamethoxazole were significant covariates influencing clearance of tacrolimus. Frequent blood monitoring and dose adjustment might be needed with the prolongation of postoperative day and coadministration with trimethoprim‐sulfamethoxazole.
Novel machine learning algorithm can identify patients at risk of poor overall survival following curative resection for colorectal liver metastases
Authors: Amygdalos Iakovos , Müller‐Franzes Gustav , Bednarsch Jan , Czigany Zoltan , Ulmer Tom Florian , Bruners Philipp , Kuhl Christiane , Neumann Ulf Peter , Truhn Daniel , Lang Sven Arke 
Published: October 2022

AbstractBackground/PurposeThe primary cause of mortality in colorectal cancer is metastatic disease. We investigated the ability of a machine learning (ML) algorithm to stratify overall survival (OS) of patients undergoing curative resection for colorectal liver metastases (CRLM).MethodsPatients undergoing curative liver resection for CRLM between 2010‐2021 at the University Hospital RWTH Aachen were eligible for this retrospective study. Patients with recurrent metastases, incomplete resections, or early deaths, were excluded. A gradient‐boosted decision tree (GBDT) model identified patients at risk of poor OS, based on clinicopathological characteristics. Differences in survival were compared with Kaplan‐Meier analysis and the log‐rank test.ResultsA total of 487 patients were split into training (n = 389, 80%) and test cohorts (n = 98, 20%). Of the latter, 20 (20%) were identified by the GBDT model as high‐risk and showed significantly reduced OS (23 months vs 52 months, P = .005) and increased hazard ratio (2.434, 95%CI 1.280‐4.627, P = .007). The strongest predictors were preoperative serum carcinoembryonic antigen (CEA), age, diameter of the largest metastasis, number of metastases, body mass index, and primary tumor grading.ConclusionA GBDT model can identify high‐risk patients regarding OS after curative resection of CRLM. Closer follow‐up and aggressive systemic treatment strategies may be beneficial to these patients.
Climatic water balance forecasting with machine learning and deep learning models over Bangladesh
Authors: Jalal Uddin Md. , Li Yubin , Abdus Sattar Md. , Mistry Sunit 
Published: October 2022

AbstractUnderstanding the impact of input variables on black‐box machine learning and deep learning models is necessary. Therefore, this study proposed SHapley Additive exPlanations (SHAP) values to address the problem of the interpretability of the output of the support vector machine (SVM), random forest (RF), convolutional neural network (CNN), and long short‐term memory (LSTM) models to forecast climatic water balance (CWB) within 1–3 months lead‐time. The current study uses two Koppen–Geiger climate zones over Bangladesh: the humid subtropical climate with dry winter and hot summer (Cwa) and the tropical climate (Af‐Am). Monthly antecedent CWB, potential evapotranspiration (PET), convective available potential energy (CAPE), relative humidity (RH), air temperature (TEM), El Niño–Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), and North Atlantic oscillation (NAO) are used as the inputs to the proposed model. SHAP values show that CWB (current month) for both climate zones has the maximum impact on the prediction. The effects of atmospheric variables and ocean–atmospheric teleconnections on CWB forecasts over Bangladesh are low. Forecasting results show that the SVM model shows the best performance for CWB forecasts in the Cwa and Af‐Am climate zones in terms of antecedent CWB as input. And this model effectively decreases the negative effect of increasing forecast lead‐time. Since the proposed model can predict CWB in 3‐months lead‐time, it would help policy‐makers and practitioners to reduce the drought and flood impacts in the future by adopting better preparedness plans.
Coronal‐plane leg alignment in adolescence and the effects of activity: A full leg length MRI study
Authors: Fernquest Scott , Lloyd Thomas , Pereira Claudio , Gimpel Mo , Birchall Richard , Broomfield John , Glyn‐Jones Sion , Palmer Antony 
Published: October 2022

AbstractThe aim of this study was to explore the association between developing coronal‐plane leg alignment and activity levels during adolescence. We performed a cross‐sectional cohort study with individuals from soccer club academies and an age‐matched control population. Outcome measures were the hip knee angle (HKA), medial proximal tibial physeal angle (MPTPhyA), lateral distal femoral physeal angle (LDFPhyA) on full leg length magnetic reasonance imagine scans, and the physical activity questionnaire (PAQ) score. The cohort comprised 57 elite male soccer players, 34 male and 34 female controls aged 11−21 years. Mean HKA became more varus with age, with little change after 16 years or skeletal maturity. Skeletally mature elite male soccer players were significantly more varus than male controls with a HKA 2.28° less than male controls (p < 0.001). Skeletally mature male controls had a HKA 1.34° less than female controls (p < 0.001). A negative correlation existed between HKA and PAQ score (coefficient −0.24, p = 0.029). A positive correlation existed between HKA and MPTPhyA (coefficient 0.32, p = 0.008). In conclusion, high activity levels during adolescence are associated with the development of varus leg alignment. Mean HKA becomes more varus with age until skeletal maturity. The development of varus alignment may represent a physiological adaptation to load at the proximal tibial physis. Clinical Significance: A time period may exist for intervention before the development of varus leg alignment in young athletes, such as training load modification or proximal tibial morphology monitoring.
Node Count as a Quality Indicator in Surgically Treated Mucosal Head and Neck Squamous Cell Cancer
Authors: Lopez Joseph , Reategui Maria Laura , Rooper Lisa , Koch Wayne , Fakhry Carole , Mydlarz Wojtech , Tan Marietta , Eisele David W. , Mandal Rajarsi , Vosler Peter , Gourin Christine G. 
Published: October 2022

IntroductionA yield of ≥18 nodes from neck dissection has been shown to be associated with improved locoregional recurrence rates and survival. We sought to determine factors associated with lymph node yields below this threshold.Materials and MethodsA retrospective review of patients who underwent neck dissection as part of definitive surgical treatment for mucosal head and neck squamous cell carcinoma (SCC) between January 2015 and December 2018 at an academic tertiary referral center was performed. Patients with a history of prior radiation or neck dissection were excluded.ResultsThere were 412 neck dissections performed in 323 patients. Specimens containing <18 nodes decreased from 16.2% in 2015–2016 to 7.4% of neck dissections in 2017–2018. The proportion of neck dissections removing <3 levels decreased from 9.1% of neck dissections in 2015–2016 to 4.0% in 2017–2018. Multivariable regression analysis demonstrated that dissection of ≥3 levels (OR = 0.2 [0.1–0.4]) and neck dissection in 2017–2018 compared to 2015–2016 (OR = 0.4 [0.2–0.8]) were significantly associated with a lower odds of <18 nodes. Stage, site, race, sex, human papillomavirus status, positive nodes, surgeon volume, and pathologist volume were not associated with neck dissection specimens with <18 nodes, after controlling for all other variables.ConclusionsIncreased recognition of the importance of node count as a quality indicator, and the extent of neck dissection is associated with increased nodal yield from neck dissection. These data suggest that node count can be used as a quality measure of neck dissection for mucosal SCC.Level of Evidence4 Laryngoscope, 133:2160–2165, 2023
Anterolateral thigh flap for upper extremity reconstruction in older patients
Authors: Ikeguchi Ryosuke , Noguchi Takashi , Ando Maki , Yoshimoto Koichi , Sakamoto Daichi , Matsuda Shuichi 
Published: October 2022

AbstractBackgroundThe anterolateral thigh (ALT) flap has been used in upper extremity reconstruction. However, there is no consensus about the age at which the flap can be used safely, which is a concern when applying ALT flaps for upper extremity reconstruction in older patients. We present the results of the use of ALT flap for upper extremity reconstruction in a series of older patients.Patients and methodsSeventeen patients who underwent ALT flaps for soft tissue defects in the upper extremities from 2010 to 2020 were included. The patients' mean age was 63.5 (range, 26–83) years. Ten of seventeen patients were smokers. Defect locations were the dorsum of the hand in seven patients, palm in two patients, dorsum and palm in two patients, and forearm in six patients. Etiologies of the defect were traumatic in 14 patients and malignant tumor in three patients. The defect size was 8 to 25 × 5 to 11 cm. When dissecting the perforators, we preserved the surrounding small muscular and fatty tissue with the perforators and to harvest them together to prevent intima damage. Flap thinning was performed for 16 flaps to adjust the flap thickness to match defect site requirements. We used an end‐to‐side or interposition arterial anastomosis to regulate the blood flow.ResultsThe flap size was 9 to 28 × 5 to 13 cm. One patient had venous congestion and vein re‐anastomosis was needed. All flaps survived. One patient had a methicillin‐resistant Staphylococcus aureus infection and debridement and irrigation was needed. The mean follow‐up period was 20 (range, 13–37) months. Fifteen patients returned their previous activities. The mean DASH score was 30.6 (range, 3–70).ConclusionsRegardless of patient age or smoking status, the ALT flap was a safe and reliable surgical option for soft tissue defect reconstruction of the upper extremity.
MLC performance prognosis using a degradation model based on trajectory log data from a daily test
Authors: Calama‐Santiago Juan Agustín , Molina‐Lopez María Yolanda , Infante‐Utrilla Miguel Ángel , Lavado‐Rodríguez María Elisa 
Published: October 2022

AbstractPurposeThis paper investigates the feasibility of implementing a predictive maintenance program for a multileaf collimator (MLC) based on data collected in trajectory logs (TLs) obtained by conducting a simple daily test, with the aim of minimizing unscheduled downtime.MethodsA dynamic field test was designed, and the TLs generated in the course of daily administration in a linear accelerator were collected to evaluate trajectory deviations of the MLC leaves as well as interlocks (COL 420219/20, COL 420207/08) reported by the machine. During this evaluation, we observed that the trajectory deviations of some leaves increased up to a threshold value beyond which certain interlocks began to appear in treatment fields in those leaves. An exponential degradation model was therefore developed to predict this drift and determine each leaf's remaining useful life (RUL). Once the applicability of the model was confirmed, we added a second accelerator equipped with an MLC with the same configuration to validate the model.ResultsThe model was able to predict certain COL 420219/20 interlocks resulting from primary readout/expected position discrepancies and to estimate each leaf's RUL. In total, 11 cases (8 interlocks + 3 potential interlocks avoided due to service interventions [27.3% of the total]) were detected over 7 days in advance, with no false positive results. Scheduling of service interventions several days prior to MLC failure would therefore be possible. When these types of interlocks were not predicted by the model, they were always generated by leaf motor failure. Consequently, intervention time could also be optimized by directly replacing the motor. During the study period, for these types of interlocks, our approach would have reduced downtime from 35.25 to 4.00 h (88.7%) and from 34.75 to 22.83 h (34.3%) for each accelerator, respectively. For COL 420207/08 interlocks, which are generated by primary/secondary readout discrepancies, no correlation with leaf trajectory deviation increases recorded in the TLs was found. Throughout the study period, these types of interlocks requiring service intervention, also mainly for motor replacement, represented a downtime of 9.50 h for the first accelerator (21.2% of total downtime) and by 4.33 h (11.1% of total downtime) for the second accelerator.ConclusionThis study demonstrates that by applying a predictive MLC maintenance program based on information collected in TLs, it is possible to predict certain interlocks and therefore schedule preemptive interventions to avoid their occurrence. This could optimize health‐care delivery performance and minimize the loss of treatment sessions.
Accelerated 4D‐flow MRI with 3‐point encoding enabled by machine learning
Authors: Kim Dahan , Jen Mu‐Lan , Eisenmenger Laura B. , Johnson Kevin M. 
Published: October 2022

PurposeTo investigate the acceleration of 4D‐flow MRI using a convolutional neural network (CNN) that produces three directional velocities from three flow encodings, without requiring a fourth reference scan measuring background phase.MethodsA fully 3D CNN using a U‐net architecture was trained in a block‐wise fashion to take complex images from three flow encodings and to produce three real‐valued images for each velocity component. Using neurovascular 4D‐flow scans (n = 144), the CNN was trained to predict velocities computed from four flow encodings by standard reconstruction including correction for residual background phase offsets. Methods to optimize loss functions were investigated, including magnitude, complex difference, and uniform velocity weightings. Subsequently, 3‐point encoding was evaluated using cross validation of pixelwise correlation, flow measurements in major arteries, and in experiments with data at differing acceleration rates than the training data.ResultsThe CNN‐produced 3‐point velocities showed excellent agreements with the 4‐point velocities, both qualitatively in velocity images, in flow rate measures, and quantitatively in regression analysis (slope = 0.96, R2 = 0.992). Optimizing the training to focus on vessel velocities rather than the global velocity error and improved the correlation of velocity within vessels themselves. The lowest error was observed when the loss function used uniform velocity weighting, in which the magnitude‐weighted inverse of the velocity frequency uniformly distributed weighting across all velocity ranges. When applied to highly accelerated data, the 3‐point network maintained a high correlation with ground truth data and demonstrated a denoising effect.ConclusionThe 4D‐flow MRI can be accelerated using machine learning requiring only three flow encodings to produce three‐directional velocity maps with small errors.
Contrast‐optimal simultaneous multi‐slice bSSFP cine cardiac imaging at 0.55 T
Authors: Tian Ye , Cui Sophia X. , Lim Yongwan , Lee Nam G. , Zhao Ziwei , Nayak Krishna S. 
Published: October 2022

PurposeTo determine if contemporary 0.55 T MRI supports the use of contrast‐optimal flip angles (FA) for simultaneous multi‐slice (SMS) balanced SSFP (bSSFP) cardiac function assessment, which is impractical at conventional field strengths because of excessive SAR and/or banding artifacts.MethodsBlipped‐CAIPI bSSFP was combined with spiral sampling for ventricular function assessment at 0.55 T. Cine movies with single band and SMS factors of 2 and 3 (SMS 2 and 3), and FA ranging from 60° to 160°, were acquired in seven healthy volunteers. Left ventricular blood and myocardial signal intensity (SI) normalized by background noise and blood–myocardium contrast were measured and compared across acquisition settings.ResultsMyocardial SI was slightly higher in single band than in SMS and decreased with an increasing FA. Blood SI increased as the FA increased for single band, and increment was small for FA ≥120°. Blood SI for SMS 2 and 3 increased with an increasing FA up to ∼100°. Blood–myocardium contrast increased with an increasing FA for single band, peaked at FA = 160° (systole: 28.43, diastole: 29.15), attributed mainly to reduced myocardial SI when FA ≥120°. For SMS 2, contrast peaked at 120° (systole: 21.43, diastole: 19.85). For SMS 3, contrast peaked at 120° in systole (16.62) and 100° in diastole (19.04).ConclusionsContemporary 0.55 T MR scanners equipped with high‐performance gradient systems allow the use of contrast‐optimal FA for SMS accelerated bSSFP cine examinations without compromising image quality. The contrast‐optimal FA was found to be 140° to 160° for single band and 100° to 120° for SMS 2 and 3.
NOE‐weighted imaging in tumors using low‐duty‐cycle2π‐CEST
Authors: Cui Jing , Sun Casey , Zu Zhongliang 
Published: October 2022

PurposeNuclear Overhauser enhancement (NOE)‐mediated CEST imaging at −3.5 ppm has shown clinical interest in diagnosing tumors. Multiple‐pool Lorentzian fit has been used to quantify NOE, which, however, requires a long scan time. Asymmetric analysis of CEST signals could be a simple and fast method to quantify this NOE, but it has contamination from the amide proton transfer (APT) at 3.5 ppm. This work proposes a new method using an asymmetric analysis of a low‐duty‐cycle pulsed‐CEST sequence with a flip angle of 360°, termed 2π‐CEST, to reduce the contribution from APT.MethodsSimulations were used to evaluate the capability of the 2π‐CEST to reduce APT. Experiments on animal tumor models were performed to show its advantages compared with the conventional asymmetric analysis. Samples of reconstituted phospholipids and proteins were used to evaluate the molecular origin of this NOE.ResultsThe 2π‐CEST has reduced contribution from APT. In tumors where we show that the NOE is comparable to the APT effect, reducing the contamination from APT is crucial. The results show that the NOE signal obtained with 2π‐CEST in tumor regions appears more homogeneous than that obtained with the conventional method. The phantom study showed that both phospholipids and proteins contribute to the NOE at −3.5 ppm.ConclusionThe NOE at −3.5 ppm has a different contrast mechanism from APT and other CEST/NOE effects. The proposed 2π‐CEST is more accurate than the conventional asymmetric analysis in detecting NOE, and requires much less scan time than the multiple‐pool Lorentzian fit.