bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of COVID‐19 pandemic on cancer surgery: Patient's perspective
Authors: Rajan Shiv , Akhtar Naseem , Tripathi Abhilasha , Kumar Vijay , Chaturvedi Arun , Mishra Prabhaker , Sharma Sonali , Misra Sanjeev , Gupta Sameer , Singh Mohit 
Published: February 2021

AbstractBackgroundCoronavirus disease 2019 (COVID‐19) has impacted cancer care globally. The aim of this study is to analyze the impact of COVID‐19 on cancer healthcare from the perspective of patients with cancer.MethodsA cross‐sectional survey was conducted between June 19, 2020, to August 7, 2020, using a questionnaire designed by patients awaiting cancer surgery. We examined the impact of COVID‐19 on five domains (financial status, healthcare access, stress, anxiety, and depression) and their relationship with various patient‐related variables. Factors likely to determine the influence of COVID‐19 on patient care were analyzed.ResultsA significant adverse impact was noted in all five domains (p =  < 0.05), with the maximal impact felt in the domain of financial status followed by healthcare access. Patients with income levels of INR < 35 K (adjusted odds ratio [AOR] = 1.61, p < 0.05), and 35K‐ 100 K (AOR = 1.96, p < 0.05), married patients (AOR = 3.30, p < 0.05), and rural patients (AOR = 2.82, p < 0.05) experienced the most adverse COVID‐19‐related impact.ConclusionDelivering quality cancer care in low to middle‐income countries is a challenge even in normal times. During this pandemic, deficiencies in this fragile healthcare delivery system were exacerbated. Identification of vulnerable groups of patients and strategic utilization of available resources becomes even more important during global catastrophes, such as the current COVID‐19 pandemic. Further work is required in these avenues to not only address the current pandemic but also any potential future crises.
Postoperative imaging surveillance for hepatocellular carcinoma: How much is enough?
Authors: Mirdad Rayyan S. , Madison Hyer J. , Diaz Adrian , Tsilimigras Diamantis I. , Azap Rosevine A. , Paro Alessandro , Pawlik Timothy M. 
Published: February 2021

AbstractBackgroundThe objective of the current study was to define trends in postoperative surveillance imaging following liver‐directed treatment of hepatocellular carcinoma (HCC), and characterize the impact of high‐intensity surveillance on long‐term survival.MethodsPatients who underwent liver‐ directed therapy for HCC between 2004 and 2016 were identified using the SEER‐Medicare database. Trends in surveillance intensity over time, factors associated with high surveillance intensity and the impact of surveillance on long‐term outcomes were examined.ResultsUtilization of high‐intensity surveillance abdominal imaging (≥6 scans over 2 years) following liver‐directed therapy of HCC decreased over time (2004–2007: n = 130, 36.1% vs. 2008–2011: n = 181, 29.5% vs. 2012–2016: n = 111, 24.5%; ptrend < 0.001). History of chronic viral hepatitis (hepatitis B: odds ratio [OR], 1.98; 95% confidence interval [CI]: 1.15–3.43; hepatitis C: OR, 1.79; 95% CI: 1.32–2.43), presence of regional (vs. local‐only) disease (OR, 1.47; 95% CI: 1.09–1.98) and receipt of transplantation (OR, 2.23; 95% CI: 1.57–3.17) were associated with higher odds of high intensity surveillance. Intensity of surveillance imaging was not associated with long‐term survival (5‐year overall survival: low‐intensity, 48.1% vs. high‐intensity, 48.9%; hazards ratio, 0.94; 95% CI: 0.78‐1.13).ConclusionUtilization of posttreatment surveillance imaging decreased over time following liver‐directed therapy for HCC. While utilization of high‐intensity screening varied by HCC procedure performed, intensity of surveillance had no effect on survival.
The Diagnostic Value of Superb Microvascular Imaging in Prediction of Uterine Artery Embolization Treatment Response in Uterine Leiomyomas
Authors: Samanci Cesur , Ozkose Burak , Ustabasioglu Fethi Emre , Erol Burak Caglar , Sirolu Sabri , Yılmaz Fatma , Ozkose Zeynep Gedik , Yılmaz Hatice , Kara Sahra Cavuşoğlu , Kicik Caliskan Raziye , Gulsen Fatih 
Published: February 2021

ObjectivesWe aimed to determine if superb microvascular imaging (SMI) can predict response to uterine artery embolization (UAE) as compared with power Doppler ultrasound.MethodsThe blood flow and the volume of the dominant leiomyoma was evaluated by power Doppler ultrasonography (PDUS) and SMI 1 day before and 3 months after the UAE procedure. SMI and PDUS blood flow were classified to 4 grades of vascularity. The change in fibroid volume in Grades 0–2 (hypovascular group) was compared to the hypervascular Grade 3 group.ResultsTwenty‐eight women (mean age, 40.9 years; range, 33–53 years) were examined with PDUS and SMI before and 3 months after UAE. The volume reduction was statistically significantly higher hypervascular group (P < .05). When we accept 30% or more volume reduction as a good response to UAE, the positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of SMI were 100, 64, 73.6, 100, and 82.1%, respectively. There was excellent agreement between the two blinded observers in SMI measurements.ConclusionsSMI, with its high reproducibility, provides further microvessel information than PDUS in uterine fibroids. It may be a useful tool in prediction of response to UAE treatment and improve counseling and patient selection for UAE versus medical or surgical treatment options.
ACR BI‐RADS Category 3 Lesions in Women Younger Than 30: Follow‐up Outcomes and Factors Associated With Biopsy
Authors: Merchant Kanwal , Omar Lena , Hayes Jody , Compton Lindsay , Polat Dogan , Xi Yin , Dogan Basak 
Published: February 2021

ObjectiveInvestigate imaging follow‐up patterns and assessment of malignancy rate of BI‐RADS 3 lesions in women younger than 30 years.MethodsWe retrospectively reviewed consecutive studies between January 1, 2013 and January 1, 2015 with BI‐RADS 3 assessment in women <30 years. Lesion size, follow‐up rate, and biopsy rate were recorded. Completion of 24‐month imaging follow‐up or biopsy determined the endpoint. Statistical analysis of follow‐up rates and biopsy timing was performed.ResultsOf 2525 BI‐RADS 3 lesions, 278 were identified in 215 women <30 years. Fifty‐two (24%) women underwent a biopsy which was more frequently done at patient request than for lesion growth [33 (63.4%) versus 19 (36.5%), P <.01]. The odds of having biopsy upfront was significantly higher in lesions >2 cm in diameter (OR: 4.4 [95% CI 2.1–9.4], P <.01). The malignancy rate in our cohort was 0% (95% CI 0–1.7%). Of the 188 women expected for follow‐up imaging, 58 (30%) were lost to follow‐up, while 103 (55%) had 6‐month follow‐up, 74 (39%) 12‐month follow‐up, and 56 (30%) 24‐month follow‐up.ConclusionsBI‐RADS 3 lesions identified in our cohort had high biopsy rates and low compliance with no cancers. Our findings suggest that probable fibroadenomas in young women may only warrant abbreviated short‐term follow‐up at 6‐months.
Predictive Factors for Efficacious Oral Appliance Therapy in Moderate to Severe Obstructive Sleep Apnea Patients
Authors: Buiret Guillaume , Bechara Maroun , Plouin‐Gaudon Isabelle , Bavozet Frederique , Dancea Olivia , Pujo Kevin , Chidiac Frederic 
Published: February 2021

Objectives/HypothesisOral appliances (OAs) are a treatment for obstructive sleep apnea hypopnea syndrome (OSAHS). The main objective of the study was to determine the predictive factors of OA efficacy. The secondary objective was to measure the efficacy rates and determine OAs' tolerance and dropout.Study DesignRetrospective study.MethodsEfficacy results of the OAs based on the apnea hypopnea index (AHI) reduction, complications, and dropout rates were retrospectively collected from 347 patients with a moderate to severe OSAHS treated by a retention OA. The procedure was entirely performed by otolaryngologists.ResultsThe AHI with OA was more significantly reduced in patients with a higher initial AHI and a higher initial body mass index but reduction was not related to age and not proportional to the degree of mandibular advancement. The 50% AHI reduction rate after OA was 65.2%, the AHI ≤5/hr rate after OA was 26.1%, and the <50% AHI reduction and residual AHI > 10/hr rate was 50.1%. The OA significantly reduced the mean AHI (−14.9/hr, P < .0001). In 7.8% of patients, the AHI increased with OA. Seven patients (1.5%) experienced adverse effects. Thirty‐seven (7.8%) patients stopped using OA mainly because of its ineffectiveness. Advancement can be considered beyond the initial maximal advancement. It can be effective sometimes; however, increasing advancement did not significantly reduce AHI.ConclusionsOA is an effective and well‐tolerated treatment for moderate to severe OSAHS. This treatment was effective for reduction of the AHI ≥50% in two‐thirds of cases studied and it should be considered in more cases.Level of Evidence4 Laryngoscope, 131:E2089–E2096, 2021
Incident Fluence Analysis for 755‐nm Picosecond Laser Treatment of Pigmented Skin Lesions Based on Threshold Fluences for Melanosome Disruption
Authors: Shimojo Yu , Nishimura Takahiro , Hazama Hisanao , Ito Nobuhisa , Awazu Kunio 
Published: February 2021

Background and ObjectivesIn this study, the threshold fluences for disrupting the melanosomes for pigmented skin lesion treatment were determined using a 755‐nm picosecond laser for clinical use. Based on the melanosome disruption thresholds, incident fluences corresponding to the target lesion depths were evaluated in silico for different laser spot sizes.Study Design/Materials and MethodsMelanosome samples were isolated from porcine eyes as alternative samples for human cutaneous melanosomes. The isolated melanosomes were exposed to 755‐nm picosecond laser pulses to measure the mean particle sizes by dynamic light scattering and confirm their disruption by scanning electron microscopy. The threshold fluences were statistically determined from the relationships between the irradiated fluences and the mean particle sizes. Incident fluences of picosecond laser pulses for the disruption of melanosomes located at different depths in skin tissue were calculated through a light transport simulation using the obtained thresholds.ResultsThe threshold fluences of 550‐ and 750‐picosecond laser pulses were determined to be 2.19 and 2.49 J/cm2, respectively. The numerical simulation indicated that appropriate incident fluences of picosecond laser pulses differ depending on the depth distribution of the melanosomes in the skin tissue, and large spot sizes are desirable for disrupting the melanosomes more deeply located within the skin tissue.ConclusionThe threshold fluences of picosecond laser pulses for melanosome disruption were determined. The incident fluence analysis based on the thresholds for melanosome disruption provides valuable information for the selection of irradiation endpoints for picosecond laser treatment of pigmented skin lesions. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC
Fatigue strength of helical compression springs ‐ comparison of calculation methods according to DIN EN 13906‐1 and Forschungskuratorium Maschinenbau (FKM) guideline “Analytical strength assessment of springs and spring elements”
Authors: Niwinski T.J. , Geilen M.B. , Klein M. , Sharma E. , Schommartz J.O. , Oechsner M. 
Published: February 2021

AbstractDer Lebensdauernachweis von zyklisch beanspruchten Schraubendruckfedern erfolgt zurzeit mithilfe von Goodman‐Diagrammen der DIN EN 13906‐1. Eine Auslegung gemäß der Richtlinie des Forschungskuratoriums Maschinenbau (FKM) „Rechnerischer Festigkeitsnachweis für Maschinenbauteile“ kann aufgrund zu hoher Zugfestigkeiten der Federstähle nicht erfolgen. Im Rahmen des durch die Industrielle Gemeinschaftsforschung (IGF) geförderten und 2017 abgeschlossenen Forschungsprojekts mit der Nummer 18495 BG, wurde an der TU Darmstadt und der TU Ilmenau ein Nachweisverfahren in Anlehnung an die bestehende Richtlinie des Forschungskuratoriums Maschinenbau entwickelt, welches die federspezifischen Anforderungen berücksichtigt. In der vorliegenden Publikation wird der Berechnungsalgorithmus der neuen Richtlinie des Forschungskuratoriums Maschinenbau „Rechnerischer Festigkeitsnachweis für Federn und Federelemente“ dem Verfahren nach DIN EN 13906‐1 gegenübergestellt und die Berechnungsergebnisse experimentellen Ergebnissen gegenübergestellt.
Analytical approach for the minimum depths of engagement for bolted joints with formed female threads
Authors: Kraemer F. , Klein M. , Oechsner M. 
Published: February 2021

AbstractDie quasi‐statische Beanspruchbarkeit von Schraubenverbindungen mit gefurchtem Gewinde ist neben dem Scherfestigkeitsverhältnis der eingesetzten Werkstoffe, der Einschraubtiefe, dem Flankenwinkel und der Steigung des Gewindes wesentlich abhängig von der resultierenden Flankenüberdeckung, die durch die Größe des Vorlochdurchmessers bestimmt wird. Zur Bestimmung der erforderlichen Mindesteinschraubtiefe werden Auszugsversuche mit variierter Einschraubtiefe und Gewindeüberdeckung durchgeführt. Basierend auf dem bestehenden Berechnungsansatz nach der VDI‐Richtlinie 2230 (Verein Deutsche Ingenieure) für Verschraubungen in vorgeschnittene Mutterngewinde wird eine analytische Bewertungsmethode abgeleitet, um für Verbindungen mit gefurchtem Mutterngewinde die erforderliche Mindesteinschraubtiefe unter Berücksichtigung der Gewindeausformung des gefurchten Gewindes zu bestimmen.
Small extracellular vesicles‐based cell‐free strategies for therapy
Authors: Guo Yeye , Wang Huaishan , Huang Lili , Ou Lingling , Zhu Jinjin , Liu Shujing , Xu Xiaowei 
Published: February 2021

AbstractSmall extracellular vesicles (sEVs) are extracellular nanovesicles that contain bioactive proteins, lipids, RNA, and DNA. A variety of biological process is regulated with sEVs. sEVs are an intercellular messenger regulating recipient cell function and play a role in disease initiation and progression. sEVs derived from certain cells, such as mesenchymal stem cells and immune cells, have the potential for clinical therapy as they possess the characteristics of their parental cells. With better understanding of sEVs biogenesis, their transportation properties, extended circulatory capability, and exceptional biocompatibility, sEVs emerge as a potential therapeutic tool in the clinic. Here, we summarize applications of sEVs‐based therapies in different diseases and current knowledge about the strategies in bioengineered sEVs, as well as the challenges for their use in clinical settings.
Free tensor fascia lata true‐perforator flap transfer for reconstruction of the calcaneal soft tissue defect complicated with osteomyelitis in a patient with alcohol‐induced Charcot foot: A case report and literature review
Authors: Tsuihiji Kanako , Daniel Bassem W. , Kageyama Takashi , Sakai Hayahito , Fuse Yuma , Tsukuura Reiko , Yamamoto Takumi 
Published: February 2021

AbstractCharcot foot is can result in bone deformities and soft tissue defects. We report a case of alcohol‐induced Charcot (AIC) foot with soft tissue defect including the weight‐bearing zone of the heel and osteomyelitis, which was successfully reconstructed with free tensor fascia lata true‐perforator flap (TFLtp). A 56‐year‐old male suffered from AIC foot with an 18 × 6 cm defect. Based on the preoperative ultrasound, we identified the overlying upper thigh area offering one of the thickest dermis. A TFLtp flap was raised sparing the TFL muscle based on one perforator without including the main trunk of the transverse/ascending branch of the lateral femoral circumflex vessel. The TFLtp flap was transferred to the heel and anastomosed to the posterior tibial artery in an end‐to‐side fashion. The patient complained no postoperative discomfort of the donor site and was able to walk on his foot after 5 weeks. This case report highlights that the TFLtp flap may offer thick dermis, faster surgery due to perforator level dissection and a concealed donor site.
Quantification of intravoxel incoherent motion with optimized b‐values using deep neural network
Authors: Lee Wonil , Kim Byungjai , Park HyunWook 
Published: February 2021

PurposeTo develop a framework for quantifying intravoxel incoherent motion (IVIM) parameters, where a neural network for quantification and b‐values for diffusion‐weighted imaging are simultaneously optimized.MethodA deep neural network (DNN) method is proposed for accurate quantification of IVIM parameters from multiple diffusion‐weighted images. In addition, optimal b‐values are selected to acquire the multiple diffusion‐weighted images. The proposed framework consists of an MRI signal generation part and an IVIM parameter quantification part. Monte‐Carlo (MC) simulations were performed to evaluate the accuracy of the IVIM parameter quantification and the efficacy of b‐value optimization. In order to analyze the effect of noise on the optimized b‐values, simulations were performed with five different noise levels. For in vivo data, diffusion images were acquired with the b‐values from four b‐values selection methods for five healthy volunteers at 3T MRI system.ResultsExperiment results showed that both the optimization of b‐values and the training of DNN were simultaneously performed to quantify IVIM parameters. We found that the accuracies of the perfusion coefficient (Dp) and perfusion fraction (f) were more sensitive to b‐values than the diffusion coefficient (D) was. Furthermore, when the noise level changed, the optimized b‐values also changed. Therefore, noise level has to be considered when optimizing b‐values for IVIM quantification.ConclusionThe proposed scheme can simultaneously optimize b‐values and train DNN to minimize quantification errors of IVIM parameters. The trained DNN can quantify IVIM parameters from the diffusion‐weighted images obtained with the optimized b‐values.
Non‐Cartesian k‐space trajectory calculation based on concurrent reading of the gradient amplifiers’ output currents
Authors: Rahmer Jürgen , Schmale Ingo , Mazurkewitz Peter , Lips Oliver , Börnert Peter 
Published: February 2021

PurposeNon‐Cartesian imaging sequences involve sampling during rapid variation of the encoding field gradients. The quality of the reconstructed images often suffers from insufficient knowledge of the exact dynamics of the actual fields applied during sampling.MethodsWe propose determination of the accurate field dynamics by measuring the currents at the gradient amplifier outputs using the amplifiers’ internal sensors concurrently with imaging. The actual dynamic field evolution is then determined by convolution with the measured current‐to‐field impulse response function of the gradient coil. Integration of the gradient field evolution allows derivation of the k‐space trajectory for reconstruction.ResultsThe current‐based approach is investigated in spiral and ultrashort TE phantom imaging. In comparison with the model‐based product reconstruction as well as a correction approach based on the conventional input waveform‐to‐field impulse response function, it provides slightly improved image quality. The improvement is ascribed to a better representation of eddy current and amplifier nonlinearity effects.ConclusionTrajectory calculation based on measured amplifier output currents offers a robust, purely measurement‐based alternative to conventional model‐based approaches. The implementation can mitigate gradient amplifier imperfections with no or little additional hardware effort.
Accelerated radial echo‐planar spectroscopic imaging using golden angle view‐ordering and compressed‐sensing reconstruction with total variation regularization
Authors: Saucedo Andres , Macey Paul M. , Thomas M. Albert 
Published: February 2021

PurposeTo implement a novel, accelerated, 2D radial echo‐planar spectroscopic imaging (REPSI) sequence using undersampled radial k‐space trajectories and compressed‐sensing reconstruction, and to compare results with those from an undersampled Cartesian spectroscopic sequence.MethodsThe REPSI sequence was implemented using golden‐angle view‐ordering on a 3T MRI scanner. Radial and Cartesian echo‐planar spectroscopic imaging (EPSI) data were acquired at six acceleration factors, each with time‐equivalent scan durations, and reconstructed using compressed sensing with total variation regularization. Results from prospectively and retrospectively undersampled phantom and in vivo brain data were compared over estimated concentrations and Cramer‐Rao lower‐bound values, normalized RMS errors of reconstructed metabolite maps, and percent absolute differences between fully sampled and reconstructed spectroscopic images.ResultsThe REPSI method with compressed sensing is able to tolerate greater reductions in scan time compared with EPSI. The reconstruction and quantitation metrics (i.e., spectral normalized RMS error maps, metabolite map normalized RMS error values [e.g., for total N‐acetyl asparate, REPSI = 9.4% vs EPSI = 16.3%; acceleration factor = 2.5], percent absolute difference maps, and concentration and Cramer‐Rao lower‐bound estimates) showed that accelerated REPSI can reduce the scan time by a factor of 2.5 while retaining image and quantitation quality.ConclusionAccelerated MRSI using undersampled radial echo‐planar acquisitions provides greater reconstruction accuracy and more reliable quantitation for a range of acceleration factors compared with time‐equivalent compressed‐sensing reconstructions of undersampled Cartesian EPSI. Compared to the Cartesian approach, radial undersampling with compressed sensing could help reduce 2D spectroscopic imaging acquisition time, and offers a better trade‐off between imaging speed and quality.
An offline multi‐scale unsaturated poromechanics model enabled by self‐designed/self‐improved neural networks
Authors: Heider Yousef , Suh Hyoung Suk , Sun WaiChing 
Published: February 2021

AbstractSupervised machine learning via artificial neural network (ANN) has gained significant popularity for many geomechanics applications that involves multi‐phase flow and poromechanics. For unsaturated poromechanics problems, the multi‐physics nature and the complexity of the hydraulic laws make it difficult to design the optimal setup, architecture, and hyper‐parameters of the deep neural networks. This paper presents a meta‐modeling approach that utilizes deep reinforcement learning (DRL) to automatically discover optimal neural network settings that maximize a pre‐defined performance metric for the machine learning constitutive laws. This meta‐modeling framework is cast as a Markov Decision Process (MDP) with well‐defined states (subsets of states representing the proposed neural network (NN) settings), actions, and rewards. Following the selection rules, the artificial intelligence (AI) agent, represented in DRL via NN, self‐learns from taking a sequence of actions and receiving feedback signals (rewards) within the selection environment. By utilizing the Monte Carlo Tree Search (MCTS) to update the policy/value networks, the AI agent replaces the human modeler to handle the otherwise time‐consuming trial‐and‐error process that leads to the optimized choices of setup from a high‐dimensional parametric space. This approach is applied to generate two key constitutive laws for the unsaturated poromechanics problems: (1) the path‐dependent retention curve with distinctive wetting and drying paths. (2) The flow in the micropores, governed by an anisotropic permeability tensor. Numerical experiments have shown that the resultant ML‐generated material models can be integrated into a finite element (FE) solver to solve initial‐boundary‐value problems as replacements of the hand‐craft constitutive laws.