bluuebunny/crossref_metadata_2025_split huggingface dataset:
TH‐EF‐207A‐02: Imaging Pancreatic Î2‐Cell Function with 51/52Mn‐PET
Authors: Graves S , Hernandez R , England C , Valdovinos H , Jeffery J , Barnhart T , Cai W , Nickles R 
Published: July 2016

Purpose:To image β‐cells noninvasively using radio‐manganese PET and to develop efficient small cyclotron production of 51Mn (t1/2=46m, β+=97%) and 52Mn (t1/2=5.6d, β+=29%).Methods:51Mn and 52Mn were produced by 16 MeV proton irradiation (GE PETtrace) of electrodeposited 54Fe on silver and Cr metal pressed into a silver disc, respectively. 51Mn was radiochemically isolated from target material by anion exchange chromatography and 52Mn was isolated by ethanolic anion exchange trap‐and‐release. A final injectable product of 51Mn2+ or 52Mn2+ was obtained in 0.01M pH 6.0 NaOAc. To assess pancreatic uptake, fasted ICR mice were administered and intravenous bolus or infusion of 52Mn2+. Additionally, to demonstrate the correlation between β‐cell function and 52Mn2+ pancreatic uptake, prior to tracer administration groups of ICR mice were administered glibenclamide (5mg/kg) and diazoxide (20 mg/kg) as an insulin release stimulator and blocker, respectively. To validate PET ROI quantification, ex vivo biodistribtution studies were conducted on each subject after the final imaging time‐point.Results:Dynamic PET data using a left atrium ROI revealed that 52Mn2+ cleared from the blood with a 10 second half‐life. Significant uptake was seen in the pancreas (approximately 20% ID/g, SUVmean= 5.5), liver, kidneys, intestine, heart, and thyroid. Pancreatic uptake was found to be highly sensitive to volatile anesthesia administration (p=0.0002), insulin release stimulation by glibenclamide (p=0.017), and by insulin release inhibition by diazoxide (p=0.046). Excellent agreement was found between in vivo PET ROI quantification and ex vivo biodistribution measurements.Conclusion:This work demonstrates the feasibility of using radiomanganese‐PET for measuring functional β‐cell mass in vivo. The decay characteristics and dosimetric properties of 51Mn are well suited for clinical PET, which will allow for rapid translation and application.
TH‐EF‐207A‐04: A Dynamic Contrast Enhanced Cone Beam CT Technique for Evaluation of Renal Functions
Authors: Wang Z , Shi J , Yang Y 
Published: July 2016

Purpose:To develop a simple but robust method for the early detection and evaluation of renal functions using dynamic contrast enhanced cone beam CT technique.Methods:Experiments were performed on an integrated imaging and radiation research platform developed by our lab. Animals (n=3) were anesthetized with 20uL Ketamine/Xylazine cocktail, and then received 200uL injection of iodinated contrast agent Iopamidol via tail vein. Cone beam CT was acquired following contrast injection once per minute and up to 25 minutes. The cone beam CT was reconstructed with a dimension of 300×300×800 voxels of 130×130×130um voxel resolution. The middle kidney slices in the transvers and coronal planes were selected for image analysis. A double exponential function was used to fit the contrast enhanced signal intensity versus the time after contrast injection. Both pixel‐based and region of interest (ROI)‐based curve fitting were performed. Four parameters obtained from the curve fitting, namely the amplitude and flow constant for both contrast wash in and wash out phases, were investigated for further analysis.Results:Robust curve fitting was demonstrated for both pixel based (with R2>0.8 for >85% pixels within the kidney contour) and ROI based (R2>0.9 for all regions) analysis. Three different functional regions: renal pelvis, medulla and cortex, were clearly differentiated in the functional parameter map in the pixel based analysis. ROI based analysis showed the half‐life T1/2 for contrast wash in and wash out phases were 0.98±0.15 and 17.04±7.16, 0.63±0.07 and 17.88±4.51, and 1.48±0.40 and 10.79±3.88 minutes for the renal pelvis, medulla and cortex, respectively.Conclusion:A robust method based on dynamic contrast enhanced cone beam CT and double exponential curve fitting has been developed to analyze the renal functions for different functional regions. Future study will be performed to investigate the sensitivity of this technique in the detection of radiation induced kidney dysfunction.
TH‐E‐209‐02: Dose Monitoring and Protocol Optimization: The Pediatric Perspective
Authors: MacDougall R. 
Published: July 2016

Radiation dose monitoring solutions have opened up new opportunities for medical physicists to be more involved in modern clinical radiology practices. In particular, with the help of comprehensive radiation dose data, data‐driven protocol management and informed case follow up are now feasible.Significant challenges remain however and the problems faced by medical physicists are highly heterogeneous. Imaging systems from multiple vendors and a wide range of vintages co‐exist in the same department and employ data communication protocols that are not fully standardized or implemented making harmonization complex.Many different solutions for radiation dose monitoring have been implemented by imaging facilities over the past few years. Such systems are based on commercial software, home‐grown IT solutions, manual PACS data dumping, etc., and diverse pathways can be used to bring the data to impact clinical practice. The speakers will share their experiences with creating or tailoring radiation dose monitoring/management systems and procedures over the past few years, which vary significantly in design and scope.Topics to cover: (1) fluoroscopic dose monitoring and high radiation event handling from a large academic hospital; (2) dose monitoring and protocol optimization in pediatric radiology; and (3) development of a home‐grown IT solution and dose data analysis framework.

Learning Objectives:
Describe the scope and range of radiation dose monitoring and protocol management in a modern radiology practice
Review examples of data available from a variety of systems and how it managed and conveyed.
Reflect on the role of the physicist in radiation dose awareness.
Improving the detection of environmental enteric dysfunction: a lactulose, rhamnose assay of intestinal permeability in children aged under 5 years exposed to poor sanitation and hygiene
Authors: Faubion W A , Camilleri M , Murray J A , Kelly P , Amadi B , Kosek M N , Enders F , Larson J , Grover Madhusudan , Boe G , Dyer R , Singh R 
Published: July 2016

BackgroundEnvironmental enteric dysfunction (EED) is an asymptomatic intestinal disorder affecting populations living in conditions of poor sanitation and hygiene. The study tested intestinal barrier function in infants with EED.MethodsWe prospectively studied an advanced high-performance liquid chromatography mass spectrometry assay of urine collected after oral intake of the monosaccharide, L-rhamnose and the disaccharide, lactulose, in 112 children from three continents.FindingsCompared to the US cohort (n=27), the cohorts of children from Peru (n=19) and Zambia (n=85) were older with evidence of growth impairment. The median (range) of age (months) was 8.0 (2.0 to 13.0), 27.0 (15.0 to 29.0) and 21.0 (12.0 to 36.0), respectively. The median (range) of height for age Z score was −0.1 (−1.8 to 2.4), −1.8 (−3.3 to −0.2) and −2.3 (−8.5 to 1.2), respectively. Among children with valid sugar data (n=22 USA, n=19 Peru, n=73 Zambia), there were no significant differences in the median rhamnose urine concentrations between the three groups. The median (range) lactulose concentration (µg/mL) was 6.78 (0.29 to 31.90), 47.60 (4.23 to 379.00) and 75.40 (0.67 to 873.00) in the US, Peruvian and Zambian cohorts, respectively (p<0.001). The lactulose/rhamnose ratio (LRR) was higher in cohorts from Peru (0.75, 0.15, 5.02) and Zambia (2.26, 0.08, 14.48) compared to the US (0.14, 0.06, 1.00) cohort (p<0.001). In a multivariate effect modification model, higher weight-for-age z scores were associated with lower post-dose lactulose when rhamnose excretion was constant (p=0.003).ConclusionsThis non-invasive two saccharide permeability protocol measures changes in intestinal permeability in children with EED and permits the identification of individuals for interventional trials.
Managed Activity Graded Exercise iN Teenagers and pre-Adolescents (MAGENTA) feasibility randomised controlled trial: study protocol
Authors: Brigden Amberly , Beasant Lucy , Hollingworth William , Metcalfe Chris , Gaunt Daisy , Mills Nicola , Jago Russell , Crawley Esther 
Published: July 2016

IntroductionPaediatric chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) is a relatively common and disabling condition, yet there is a limited evidence base for treatment. There is good evidence that graded exercise therapy is moderately effective in adults with CFS/ME, but there is little evidence for the effectiveness, cost-effectiveness, acceptability or best method of delivery for paediatric CFS/ME. This study aims to investigate the acceptability and feasibility of carrying out a multicentre randomised controlled trial investigating the effectiveness of graded exercise therapy compared with activity management for children/teenagers who are mildly or moderately affected with CFS/ME.Methods and analysis100 paediatric patients (8–17 years) with CFS/ME will be recruited from 3 specialist UK National Health Service (NHS) CFS/ME services (Bath, Cambridge and Newcastle). Patients will be randomised (1:1) to receive either graded exercise therapy or activity management. Feasibility analysis will include the number of young people eligible, approached and consented to the trial; attrition rate and treatment adherence; questionnaire and accelerometer completion rates. Integrated qualitative methods will ascertain perceptions of feasibility and acceptability of recruitment, randomisation and the interventions. All adverse events will be monitored to assess the safety of the trial.Ethics and disseminationThe trial has received ethical approval from the National Research Ethics Service (South West—Frenchay 15/SW/0124).Trial registration numberISRCTN23962803; Pre-results.
Sleeve gastrectomy versus Roux-en-Y gastric bypass for type 2 diabetes and morbid obesity: double-blind randomised clinical trial protocol
Authors: Murphy Rinki , Evennett Nicholas J , Clarke Michael G , Robinson Steven J , Humphreys Lee , Jones Bronwen , Kim David D , Cutfield Richard , Plank Lindsay D , Hammodat Hisham , Booth Michael W C 
Published: July 2016

IntroductionType 2 diabetes (T2D) in association with obesity is an increasing disease burden. Bariatric surgery is the only effective therapy for achieving remission of T2D among those with morbid obesity. It is unclear which of the two most commonly performed types of bariatric surgery, laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB), is most effective for obese patients with T2D. The primary objective of this study is to determine whether LSG or LRYGB is more effective in achieving HbA1c<6% (<42 mmol/mol) without the use of diabetes medication at 5 years.Methods and analysisSingle-centre, double-blind (assessor and patient), parallel, randomised clinical trial (RCT) conducted in New Zealand, targeting 106 patients. Eligibility criteria include age 20–55 years, T2D of at least 6 months duration and body mass index 35–65 kg/m2for at least 5 years. Randomisation 1:1 to LSG or LRYGB, used random number codes disclosed to the operating surgeon after induction of anaesthesia. A standard medication adjustment schedule will be used during postoperative metabolic assessments. Secondary outcomes include proportions achieving HbA1c<5.7% (39 mmol/mol) or HbA1c<6.5% (48 mmol/mol) without the use of diabetes medication, comparative weight loss, obesity-related comorbidity, operative complications, revision rate, mortality, quality of life, anxiety and depression scores. Exploratory outcomes include changes in satiety, gut hormone and gut microbiota to gain underlying mechanistic insights into T2D remission.Ethics and disseminationEthics approval was obtained from the New Zealand regional ethics committee (NZ93405) who also provided independent safety monitoring of the trial. Study commenced in September 2011. Recruitment completed in October 2014. Data collection is ongoing. Results will be reported in manuscripts submitted to peer-reviewed journals and in presentations at national and international meetings.Trial registration numbersACTRN12611000751976,NCT01486680; Pre-results.
A snapshot survey of perceptions of healthcare professionals on ageing surgeons
Authors: Rajaratnam Vaikunthan , Kumar Chandra M , Roy Chowdhury Anupama , Su Chang 
Published: July 2016

ABSTRACTObjectiveThe aim of this research was to understand healthcare professionals’ perception of the continued practice of ageing surgeons in Singapore.MethodologyA quantitative method was chosen for this research to determine healthcare professionals’ perception of the practice of ageing surgeons. Ethical approval was obtained from the local ethical review board. A cross-sectional method using a population survey was performed among healthcare professionals in two tertiary institutions and the study was confined to stakeholders in practices of ageing surgeons. The population sampled was limited to nurses in the theatre, anaesthetists, surgeons and geriatricians (physicians). An online questionnaire was designed for the survey that took into consideration the various conceptual frameworks of ageing surgeons’ practice that was obtained from a literature review.ResultsThere were 104 respondents of a population of 350 sampled (theatre nurses, anaesthetists, physicians and surgeons) giving a respondent rate of 30%. The mean age of the participants was 39.7; 72% were doctors (surgeons 34%, physicians 20% and anaesthetists 18%) and 28% nurses. Only 35% agreed with the statement that older surgeons face deterioration in cognitive faculties and 29% remained neutral. A similar trend was seen with the perception that older surgeons face a decline in memory. However, 44% agreed with the statement that older surgeons face a decline in visuospatial ability and another 40% agreed that they had a decline in psychomotor skills and reaction time. Fifty per cent agreed with the statement that they face deterioration in physical abilities. Sixty-three per cent did not think that older surgeons face a decline in reasoning and judgement. Forty-eight per cent believed that older surgeons’ vast fund of knowledge and experience could compensate for physical and cognitive changes. Only 13% agreed with the statement that older surgeons have higher surgical mortality. Forty-five per cent agreed that the retirement age should be 65 while 22% believed it should be over 65. Forty-four per cent agreed that a regular multidisciplinary, objective and comprehensive evaluation of an older surgeon’s physical and cognitive function would help to identify and treat reversible problems which when corrected would aid in restoring the surgeon’s function. Seventy-four per cent felt that it was the responsibility of all stakeholders to decide or report on when an ageing surgeon is unsafe to continue practicing. Fifty-five per cent disagreed with a mandatory retirement age for surgeons.ConclusionsThis study showed that, in Singapore, stakeholders agreed there are changes in physical and cognitive abilities of ageing surgeons but they thought that these can be overcome with selective strategies to optimise their role in the workforce. They also disagreed on a mandatory retirement age.
Average symptom trajectories following incident radiographic knee osteoarthritis: data from the Osteoarthritis Initiative
Authors: Whittle Rebecca , Jordan Kelvin P , Thomas Elaine , Peat George 
Published: July 2016

IntroductionPrevious research has identified the existence of a prodromal phase of symptom worsening beginning on average 2–3 years prior to the first appearance of radiographic knee osteoarthritis (OA). The current study extends these observations to investigate the trajectory of self-reported pain, stiffness, function and other symptoms following the incidence of radiographic OA.MethodsData were from the incidence cohort of the Osteoarthritis Initiative public use data sets. Cases were defined as knees without symptoms at enrolment, which developed incident radiographic OA (Kellgren and Lawrence grade ≥2) at any of the first 4 annual follow-up visits. Symptoms investigated were knee-specific Western Ontario & McMaster Universities Osteoarthritis Index and Knee injury and Osteoarthritis Outcome Score subscale scores and individual items, available up to 3 years before and 5 years after the incidence of radiographic OA. Trajectories of having at least one of the symptoms from a subscale, and for each individual symptom over time, were fitted using multilevel logistic regression models.ResultsThe probability of symptoms following the initial prodromal phase generally stabilised, whereas the probability of moderate, severe or extreme symptoms was consistently low. Two exceptions were pain frequency, which increased greatly in the lead up to incidence, then decreased slightly, and audible joint sounds, which had a much higher overall probability, and after increasing prior to incident radiographic OA, stabilised then started to increase again at 5 years.ConclusionsFollowing an increase in the risk of symptoms during the prodromal phase, this risk does not continue to increase in the period up to 5 years after the incidence of radiographic OA.
Hexahedral-Dominant Meshing
Authors: Sokolov Dmitry , Ray Nicolas , Untereiner Lionel , Lévy Bruno 
Published: July 2016

This article introduces a method that generates a hexahedral-dominant mesh from an input tetrahedral mesh. It follows a three-step pipeline similar to the one proposed by Carrier Baudoin et al.: (1) generate a frame field, (2) generate a pointset
P
that is mostly organized on a regular grid locally aligned with the frame field, and (3) generate the hexahedral-dominant mesh by recombining the tetrahedra obtained from the constrained Delaunay triangulation of
P
.

For step (1), we use a state-of-the-art algorithm to generate a smooth frame field. For step (2), we introduce an extension of Periodic Global Parameterization to the volumetric case. As compared with other global parameterization methods (such as CubeCover), our method relaxes some global constraints to avoid creating degenerate elements, at the expense of introducing some singularities that are meshed using non-hexahedral elements. For step (3), we build on the formalism introduced by Meshkat and Talmor, fill in a gap in their proof, and provide a complete enumeration of all the possible recombinations, as well as an algorithm that efficiently detects all the matches in a tetrahedral mesh.
The method is evaluated and compared with the state of the art on a database of examples with various mesh complexities, varying from academic examples to real industrial cases. Compared with the method of Carrier-Baudoin et al., the method results in better scores for classical quality criteria of hexahedral-dominant meshes (hexahedral proportion, scaled Jacobian, etc.). The method also shows better robustness than CubeCover and its derivatives when applied to complicated industrial models.
Exploiting Core Criticality for Enhanced GPU Performance
Authors: Jog Adwait , Kayiran Onur , Pattnaik Ashutosh , Kandemir Mahmut T. , Mutlu Onur , Iyer Ravishankar , Das Chita R. 
Published: July 2016

Modern memory access schedulers employed in GPUs typically optimize for memory throughput. They implicitly assume that all requests from different cores are equally important. However, we show that during the execution of a subset of CUDA applications, different cores can have different amounts of tolerance to latency. In particular, cores with a larger fraction of warps waiting for data to come back from DRAM are less likely to tolerate the latency of an outstanding memory request. Requests from such cores are more critical than requests from others. Based on this observation, this paper introduces a new memory scheduler, called (C)ritica(L)ity (A)ware (M)emory (S)cheduler (CLAMS), which takes into account the latency-tolerance of the cores that generate memory requests. The key idea is to use the fraction of critical requests in the memory request buffer to switch between scheduling policies optimized for criticality and locality. If this fraction is below a threshold, CLAMS prioritizes critical requests to ensure cores that cannot tolerate latency are serviced faster. Otherwise, CLAMS optimizes for locality, anticipating that there are too many critical requests and prioritizing one over another would not significantly benefit performance.
We first present a core-criticality estimation mechanism for determining critical cores and requests, and then discuss issues related to finding a balance between criticality and locality in the memory scheduler. We progressively devise three variants of CLAMS, and show that the Dynamic CLAMS provides significantly higher performance, across a variety of workloads, than the commonly-employed GPU memory schedulers optimized solely for locality. The results indicate that a GPU memory system that considers both core criticality and DRAM access locality can provide significant improvement in performance.
Rumor Source Obfuscation on Irregular Trees
Authors: Fanti Giulia , Kairouz Peter , Oh Sewoong , Ramchandran Kannan , Viswanath Pramod 
Published: July 2016

Anonymous messaging applications have recently gained popularity as a means for sharing opinions without fear of judgment or repercussion. Messages in these applications propagate anonymously (without authorship metadata) over a network that is typically defined by social connections or physical proximity. However, recent advances in rumor source detection show that the source of such an anonymous message can be inferred by statistical inference attacks. Adaptive diffusion was recently proposed as a solution that achieves optimal source obfuscation over regular trees. However, in real social networks, node degrees differ from node to node, and adaptive diffusion can be significantly sub-optimal. This gap increases as the degrees become more irregular.
In order to quantify this gap, we model the underlying network as coming from standard branching processes with i.i.d. degree distributions. Building upon the analysis techniques from branching processes, we give an analytical characterization of the dependence between the probability of detection achieved by adaptive diffusion and the degree distribution. Further, this analysis provides a key insight: passing a rumor to a friend who has many friends makes the source more ambiguous. This leads to a new family of protocols that we call Preferential Attachment Adaptive Diffusion (PAAD). When messages are propagated according to PAAD, we give both the MAP estimator for finding the source and also an analysis of the probability of detection achieved by this adversary. The analytical results are not directly comparable, since the adversary's observed information has a different distribution under adaptive diffusion than under PAAD. Instead, we present results from numerical experiments that suggest that PAAD achieves a lower probability of detection, at the cost of increased communication for coordination.