bluuebunny/crossref_metadata_2025 huggingface dataset:
Sleep quality in patients with chronic illness
Authors: Kemple Mary , O'Toole Sinead , O'Toole Conor
Published: July 2016

Aims and objectives

To explore sleep quality in patients with chronic illness in primary care.

Background

Many people suffer from chronic illness with the numbers increasing. One common issue arises from problems that people have with their quality of sleep: a largely under‐researched topic. This study exploring poor quality sleep allowed patients to describe their daily struggles with poor sleep in their own lives. This allowed the development of a deeper understanding of what it means to sleep poorly and find out how participants cope with not sleeping well.

Design

A qualitative approach enabling a deep exploration of patient's experiences of sleep quality was used. Interviews were conducted with a purposive sample of nine participants from a primary care clinic. Analysis utilised an interpretative approach.

Results

Data analysed produced four recurrent themes that were grouped into two categories. First, themes that identified the recognition by participants that ‘something was wrong’ were abrupt beginning and impact on their life. Second, themes that identified that the participants considered there was ‘nothing wrong’ were I am fine and I just carry on.

Conclusion

Data revealed that poor quality sleep can have a profound effect on quality of life. Participants lived without good quality sleep for years. They had come to accept two seemingly irreconcilable ideas that not being able to sleep is an enduring problem with a distinct starting point, and paradoxically, this is not a problem that deserves much professional attention.

Relevance to clinical practice

Important original data were generated on the impact of poor quality sleep indicating that chronically disturbed sleep can increase the disease burden on patients with chronic illness. The results of this study suggest healthcare professionals need to understand how sleep quality issues impact on patient's experience of chronic illness. Data from this study will help nurses and other health professionals to deepen their understanding of the profound impact of poor quality sleep on patients with chronic illness. A programme of education highlighting the important role of sleep quality in chronic illness is suggested by the issues raised in this study. Nurses are ideally placed to assess sleep quality in patients and tailor intervention to positively affect the quality of life for this group.
Development and validation of the Simulation Learning Effectiveness Scale for nursing students
Authors: Pai Hsiang‐Chu
Published: July 2016

Aims and objectives

To develop and validate the Simulation Learning Effectiveness Scale, which is based on Bandura's social cognitive theory.

Background

A simulation programme is a significant teaching strategy for nursing students. Nevertheless, there are few evidence‐based instruments that validate the effectiveness of simulation learning in Taiwan.

Design

This is a quantitative descriptive design.

Methods

In Study 1, a nonprobability convenience sample of 151 student nurses completed the Simulation Learning Effectiveness Scale. Exploratory factor analysis was used to examine the factor structure of the instrument. In Study 2, which involved 365 student nurses, confirmatory factor analysis and structural equation modelling were used to analyse the construct validity of the Simulation Learning Effectiveness Scale.

Results

In Study 1, exploratory factor analysis yielded three components: self‐regulation, self‐efficacy and self‐motivation. The three factors explained 29·09, 27·74 and 19·32% of the variance, respectively. The final 12‐item instrument with the three factors explained 76·15% of variance. Cronbach's alpha was 0·94. In Study 2, confirmatory factor analysis identified a second‐order factor termed Simulation Learning Effectiveness Scale. Goodness‐of‐fit indices showed an acceptable fit overall with the full model (χ2/df (51) = 3·54, comparative fit index = 0·96, Tucker–Lewis index = 0·95 and standardised root‐mean‐square residual = 0·035). In addition, teacher's competence was found to encourage learning, and self‐reflection and insight were significantly and positively associated with Simulation Learning Effectiveness Scale. Teacher's competence in encouraging learning also was significantly and positively associated with self‐reflection and insight. Overall, theses variable explained 21·9% of the variance in the student's learning effectiveness.

Conclusion

The Simulation Learning Effectiveness Scale is a reliable and valid means to assess simulation learning effectiveness for nursing students.

Relevance to clinical practice

The Simulation Learning Effectiveness Scale can be used to examine nursing students' learning effectiveness and serve as a basis to improve student's learning efficiency through simulation programmes. Future implementation research that focuses on the relationship between learning effectiveness and nursing competence in nursing students is recommended.
Polysomnography findings in spinocerebellar ataxia type 6
Authors: Rueda Adriana D. , Pedroso José L. , Truksinas Eveli , Do Prado Gilmar F. , Coelho Fernando M. , Barsottini Orlando G.
Published: July 2016

Spinocerebellar ataxia type 6 (SCA6) is usually described as a pure ataxia syndrome. However, SCA6 patients may have sleep complaints. In this paper, sleep disorders were investigated in patients with SCA6. Twelve SCA6 patients and 12 subjects matched by gender, age and body mass index (control group) underwent polysomnography and clinical investigation for sleep disorders. SCA6 had a higher frequency of snoring (P = 0.01), a higher index of awakening due to respiratory events (P = 0.003) and central apnea events during sleep (P = 0.024), a longer sleep Stage N1 (P = 0.02) and a lower sleep Stage N3 (P = 0.05) in SCA6 patients than in control subjects. SCA6 patients had a reduction in slow wave sleep and a higher frequency of snoring and respiratory disorders during sleep when compared to the control group.
The strange case of ‘John Black’ and ‘Mr Hyde’: constructing migrating Jamaicans as (un)worthy nationals
Authors: Braun James
Published: July 2016

This paper examines how migrating Jamaicans were constructed as ‘worthy’ or ‘unworthy’ of Jamaican diasporic membership in the early years of statehood, to demonstrate the role of nationalist cultural repertoires in constructing particular diasporic imaginaries. I conduct a discourse analysis of Jamaica's national newspaper, The Daily Gleaner, between 1962 and 1966, a period encompassing crucial transitions in Jamaican migration movements and from colony to statehood. I argue that tropes of respectability present in Afro‐creole nationalist ideology form the cultural repertoires used to distinguish migrants' actions as worthy or unworthy of national membership. These distinctions specify who ‘counts’ as part of the diaspora and how migrants of different social positions may claim and articulate their membership.
The oldest Gondwanan cephalopod mandibles (Hangenberg Black Shale, Late Devonian) and the mid‐Palaeozoic rise of jaws
Authors: Klug Christian , Frey Linda , Korn Dieter , Jattiot Romain , Rücklin Martin
Published: July 2016

It is widely accepted that the effects of global sea‐level changes at the transition from the Devonian to the Carboniferous are recorded in deposits on the shelf of northern Gondwana. These latest Devonian strata had been thought to be poor in fossils due to the Hangenberg mass extinction. In the Ma'der (eastern Anti‐Atlas), however, the Hangenberg Black Shale claystones (latest Famennian) are rich in exceptionally preserved fossils displaying the remains of non‐mineralized structures. The diversity in animal species of these strata is, however, low. Remarkably, the organic‐rich claystones have yielded abundant remains of Ammonoidea preserved with their jaws, both in situ and isolated. This is important because previously, the jaws of only one of the main Devonian ammonoid clades had been found (Frasnian Gephuroceratina). Here, we describe four types of jaws of which two could be assigned confidently to the Order Clymeniida and to the Suborder Tornoceratina. These findings imply that chitinous normal‐type jaws were likely to have already been present at the origin of the whole clade Ammonoidea, i.e. in the early Emsian (or earlier). Vertebrate jaws evolved prior to the Early Devonian origin of ammonoids. The temporal succession of evolutionary events suggests that it could have been the indirect positive selection pressure towards strong (and thus preservable) jaws since defensive structures of potential prey animals would otherwise have made them inaccessible to jawless predators in the course of the mid‐Palaeozoic marine revolution. In this respect, our findings reflect the macroecological changes that occurred in the Devonian. [Correction added on 28 July 2016 after first online publication: In the Abstract, the sentence “Vertebrate jaws probably … in the Early Devonian” was amended]
Successful Treatment of Pediatric Alopecia Areata of the Scalp Using Topical Bimatoprost
Authors: Li Alvin W. , Antaya Richard J.
Published: July 2016

Alopecia areata (AA) is a genetic and immune‐mediated disease that targets anagen hair follicles. Despite limited evidence supporting the efficacy of corticosteroid treatments, they are often prescribed as first‐line therapy because of their favorable safety profile. Prostaglandin analogues are currently being studied as an alternate therapy for scalp AA in adults. Herein we present a case of steroid‐resistant multifocal AA that was successfully treated with topical bimatoprost.
Determinants of neonatal mortality in rural and urban Nigeria: Evidence from a population‐based national survey
Authors: Adewuyi Emmanuel O , Zhao Yun
Published: July 2016

Background

Significant reduction in the global burden of neonatal mortality was achieved through the millennium development goals. In Nigeria, however, only a marginal reduction was realized. This study assesses the rural–urban differences in neonatal mortality rate (NMR) and the associated risk factors in Nigeria.

Methods

The dataset from the 2013 Nigeria demographic and health survey (NDHS), disaggregated by rural–urban residence (n = 20 449 and 9935, respectively), was explored using univariate, bivariate, and multivariable analysis. Complex samples analysis was applied to adjust for the unequal selection probabilities due to the multi‐stage cluster sampling method used in the 2013 NDHS. The adjusted relationship between the outcome and predictor variables was assessed on multi‐level logistic regression analysis.

Results

NMR for rural and urban populations was 36 and 28 deaths per 1000 live births, respectively. Risk factors in urban residence were lack of electricity access (adjusted OR [AOR], 1.555; 95%CI: 1.089–2.220), small birth size (as a proxy for low birthweight; AOR, 3.048; 95%CI: 2.047–4.537), and male gender (AOR, 1.666; 95%CI: 1.215–2.284). Risk factors in rural residence were small birth size (a proxy for low birthweight; AOR, 2.118; 95%CI: 1.600–2.804), and birth interval <2 years (AOR, 2.149; 95%CI: 1.760–2.624). Cesarean delivery was a risk factor both in rural (AOR, 5.038; 95%CI: 2.617–9.700) and urban Nigeria (AOR, 2.632; 95%CI: 1.543–4.489).

Conclusions

Determinants of neonatal mortality were different in rural and urban Nigeria, and rural neonates had greater risk of mortality than their urban counterparts.
Evidence and Inference
Authors: Bird Alexander
Published: July 2016

I articulate a functional characterisation of the concept of evidence, according to which evidence is that which allows us to make inferences that extend our knowledge. This entails Williamson's equation of knowledge with evidence.
Type 2 diabetes is associated with a higher incidence of hospitalization for pulmonary embolism in Spain: Analysis of hospital discharge data during 2004–2013
Authors: de Miguel‐Díez Javier , Muñoz‐Rivas Nuria , Jiménez‐García Rodrigo , Hernández‐Barrera Valentín , Carrasco‐Garrido Pilar , Monreal Manuel , Jiménez David , Guijarro Ricardo , López de Andrés Ana
Published: July 2016

Background and objective

We compared the incidence and outcome of pulmonary embolism (PE) in individuals with and without type 2 diabetes mellitus (T2DM) in Spain during 2004–2013.

Methods

The study was based on National Hospital Discharge Data, and the study population comprised patients hospitalized for PE. Annual incidence rates were classified according to T2DM status. In‐hospital mortality (IHM), length of hospital stay (LOHS), comorbidities and use of diagnosis and therapeutic procedures were analysed.

Results

We identified 123 872 discharges of patients (56 361 men and 67 511 women) with PE as their primary diagnosis (15.3% with T2DM). Incidence of discharge diagnoses of PE increased significantly in all groups. Crude rates were higher in diabetic patients. A positive association was identified between T2DM and PE: adjusted IRR was 2.00 (95% CI: 1.95–2.05) for men and 2.50 (95% CI: 2.45–2.57) for women. LOHS, readmissions and IHM decreased significantly for both groups. An association between IHM and risk factors (older age, Charlson comorbidity index >3, atrial fibrillation and cancer) was observed. T2DM was associated with higher IHM in men (OR: 1.22, 95% CI: 1.12–1.32) and women (OR: 1.24, 95% CI: 1.15–1.33). The use of computed tomography pulmonary angiography increased significantly overtime.

Conclusion

We confirmed that in both men and women, diabetes was an independent risk factor for IHM. The incidence of discharge of patients with PE increased significantly during the study period. Diabetic men and women had a higher risk of hospitalization for PE than non‐diabetic men and women. Diabetic women had higher IHM than diabetic men.
Phenotypic reversion in fas mutants of Arabidopsis thaliana by reintroduction of FAS genes: variable recovery of telomeres with major spatial rearrangements and transcriptional reprogramming of 45S rDNA genes
Authors: Pavlištová Veronika , Dvořáčková Martina , Jež Michal , Mozgová Iva , Mokroš Petr , Fajkus Jiří
Published: July 2016

Arabidopsis thaliana mutants dysfunctional in the evolutionarily conserved protein complex chromatin assembly factor‐1 (CAF‐1), which deposits the canonical histone H3 variant H3.1 during DNA synthesis‐dependent chromatin assembly, display complex phenotypic changes including meristem and growth alterations, sensitivity to DNA‐damaging agents, and reduced fertility. We reported previously that mutants in the FAS1 subunit of CAF‐1 progressively lose telomere and 45S rDNA repeats. Here we show that multiple aspects of the fas phenotype are recovered immediately on expression of a reintroduced FAS1 allele, and are clearly independent of the recovery of rDNA copy‐numbers and telomeres. In reverted lines, 45S rDNA genes are recovered to diverse levels with a strikingly different representation of their variants, and the typical association of nucleolar organizing region 4 with the nucleolus is perturbed. One of 45S rDNA variants (VAR1), which is silenced in wild‐type (WT) plants without mutation history (Col‐0 WT), dominates the expression pattern, whereas VAR2 is dominant in Col‐0 WT plants. We propose an explanation for the variability of telomere and 45S rDNA repeats associated with CAF‐1 function, suggesting that the differences in nuclear partitioning and expression of the rDNA variants in fas mutants and their revertants provide a useful experimental system to study genetic and epigenetic factors in gene dosage compensation.
IMAGING DIAGNOSIS—A LUMINAL LAMINATED DEBRIS BALL IN THE URINARY BLADDER OF A DOG
Authors: Yoon Hakyoung , Kim Hanjin , Jung Uook , Eom Kidong
Published: July 2016

A 5‐year‐old dog presented with pollakiuria and urinary incontinence. Abdominal radiographs revealed an oval, multilayered structure with soft tissue opacity and gas lucency in the urinary bladder. Ultrasonography showed an oval luminal structure with hyper‐ and hypoechoic layers and internal reverberation artifacts. Following cystotomy, the hemisected plane showed a layered, pale whitish matrix with a gas layer around the core. Histopathological examination showed no evidence of cells, bacteria, or fungi. The core and laminae comprised fibrinous and mineral debris. A final diagnosis of a freely floating, gas‐filled laminated debris ball was made.
COMPUTED TOMOGRAPHY OF TOOTH RESORPTION IN CATS
Authors: Lang Linda G. , Wilkinson Thomas E. , White Tammy L. , Farnsworth Raelynn K. , Potter Kathleen A.
Published: July 2016

Tooth resorption is the most common dental disease in cats and can be a source of oral pain. The current clinical gold standard for diagnosis includes a combination of oral exam and dental radiography, however early lesions are not always detected. Computed tomography (CT) of the skull, including the dental arches, is a commonly performed diagnostic procedure, however the appearance of tooth resorption on CT and the diagnostic ability of CT to detect tooth resorption have not been evaluated. The purpose of this prospective, descriptive, diagnostic accuracy study was to characterize the CT appearance of tooth resorption in a sample of affected cats and to evaluate the sensitivity and specificity of CT for tooth resorption compared to the clinical gold standard of oral exam and intraoral dental radiography. Twenty‐eight cat cadaver specimens were recruited for inclusion. Each specimen was evaluated using oral exam, intraoral dental radiography, and computed tomography (four different slice thicknesses). Each tooth was evaluated for the presence or absence of tooth resorption. Teeth with lesions and a subset of normal teeth were evaluated with histopathology. On CT, tooth resorption appeared as irregularly marginated hypoattenuating defects in the mineral attenuating tooth components, most commonly involving the root or cementoenamel junction. Sensitivity for CT detection of tooth resorption was fair to poor (42.2–57.7%) and specificity was good to excellent (92.8–96.3%). Findings from this study indicated that CT has high specificity but low sensitivity for detection of tooth resorption in cats.
N‐linked glycosylation of Kv1.2 voltage‐gated potassium channel facilitates cell surface expression and enhances the stability of internalized channels
Authors: Thayer Desiree A. , Yang Shi‐Bing , Jan Yuh Nung , Jan Lily Y.
Published: July 2016

Key points

Kv1.2 and related voltage‐gated potassium channels have a highly conserved N‐linked glycosylation site in the first extracellular loop, with complex glycosylation in COS‐7 cells similar to endogenous Kv1.2 glycosylation in hippocampal neurons.

COS‐7 cells expressing Kv1.2 show a crucial role of this N‐linked glycosylation in the forward trafficking of Kv1.2 to the cell membrane.

Although both wild‐type and non‐glycosylated mutant Kv1.2 channels that have reached the cell membrane are internalized at a comparable rate, mutant channels are degraded at a faster rate.

Treatment of wild‐type Kv1.2 channels on the cell surface with glycosidase to remove sialic acids also results in the faster degradation of internalized channels.

Glycosylation of Kv1.2 is important with respect to facilitating trafficking to the cell membrane and enhancing the stability of channels that have reached the cell membrane.

Studies in cultured hippocampal neurons and the COS‐7 cell line demonstrate important roles for N‐linked glycosylation of Kv1.2 channels in forward trafficking and protein degradation. Kv1.2 channels can contain complex N‐linked glycans, which facilitate cell surface expression of the channels. Additionally, the protein stability of cell surface‐expressed Kv1.2 channels is affected by glycosylation via differences in the degradation of internalized channels. The present study reveals the importance of N‐linked complex glycosylation in boosting Kv1.2 channel density. Notably, sialic acids at the terminal sugar branches play an important role in dampening the degradation of Kv1.2 internalized from the cell membrane to promote its stability.
Analysis of Computational Fluid Dynamics Code FLUENT Capabilities for Supercritical Water Heat-Transfer Applications in Vertical Bare Tubes
Authors: Farah Amjad , Harvel Glenn , Pioro Igor
Published: July 2016

In this paper, the computational fluid dynamics (CFD) code FLUENT was used to predict wall-temperature profiles inside vertical bare tubes with supercritical water (SCW) as the cooling medium, to assess the capabilities of FLUENT for SCW heat-transfer applications. Numerical results are compared to experimental data and current one-dimensional (1D) models represented by existing heat-transfer empirical correlations. Wall-temperature and heat-transfer coefficients were analyzed to select the best model to describe the fluid flow before, at, and after the pseudocritical region. k−ϵ and k−ω turbulent models were evaluated in the process, with variations in the submodel parameters such as viscous heating, thermal effects, and low-Reynolds-number correction. Results of the analysis show a fit of ±10% for wall temperatures using the SST k−ω model within the deteriorated heat-transfer regime and less than ±5% within the normal heat-transfer regime. The accuracy of the model is higher than any empirical correlation tested in the mentioned regimes and provides additional information about the multidimensional effects between the bulk-fluid and wall temperatures.
Dissipativity-Based Reliable Sampled-Data Control With Nonlinear Actuator Faults
Authors: Santra Srimanta , Sakthivel R. , Kaviarasan B.
Published: July 2016

In this paper, the problem of reliable sampled-data control design with strict dissipativity for a class of linear continuous-time-delay systems against nonlinear actuator faults is studied. The main objective of this paper is to design a reliable sampled-data controller to ensure a strictly dissipative performance for the closed-loop system. Based on the linear matrix inequality (LMI) optimization approach and Wirtinger-based integral inequality, a new set of sufficient conditions is established for reliable dissipativity analysis of the considered system by assuming the mixed actuator fault matrix to be known. Then, the proposed result is extended to unknown fault matrix case. Also, the reliable sampled-data controller with strict dissipativity is designed by solving a convex optimization problem which can be easily solved by using standard numerical algorithms. Finally, a numerical example based on liquid propellant rocket motor with a pressure feeding system model is presented to illustrate the effectiveness of the developed control design technique.
Prediction and Recovery of Aircraft Unstable Nonlinear Phenomena Using Bifurcation Analysis and Backstepping Method
Authors: Xin Qi , Shi Zhongke
Published: July 2016

To protect the aircraft flight safety across the envelope of angle of attack, bifurcation analysis and backstepping method are investigated to predict and suppress the unstable nonlinear flight phenomena. By applying bifurcation analysis and continuation method to the flight motion, the onsets of both the chaotic phenomenon called falling leaf motion and the catastrophe phenomenon named coupled jump behavior are derived. To stabilize these unstable motions, a backstepping and disturbance observer based flight controller is designed. According to the main function of the control surface, we divide the flight controller into the airspeed subsystem and the flight path subsystem, where the airspeed subsystem is regulated by an adaptive dynamic inversion controller while the flight path subsystem is stabilized by a third-order compound controller. Considering the parametric uncertainties of aerodynamics, three sliding mode disturbance observers are presented as compensators to approximate the compound uncertainties. Simulations demonstrate that the proposed controller can recover the aircraft from falling leaf motion or coupled jump behavior to straight level flying.
An Effectiveness–Number of Transfer Units Relationship for Evaporators With Non-negligible Boiling Point Elevation Increases
Authors: Thiel Gregory P. , Lienhard John H.
Published: July 2016

An effectiveness number of transfer units (ε–NTU) model is developed for use in evaporators where the evaporating stream: (1) comprises a volatile solvent and nonvolatile solute(s) and (2) undergoes a significant, but linear change in boiling point elevation (BPE) with increasing solute molality. The model is applicable to evaporators driven by an isothermal stream (e.g., steam-driven or refrigerant-driven) in parallel flow, counterflow, and crossflow configurations where the evaporating stream is mixed. The model is of use in a variety of process engineering applications as well as the sizing and rating of evaporators in high-salinity desalination systems.
A Numerical Model of a Reciprocating-Mechanism Driven Heat Loop for Two-Phase High Heat Flux Cooling
Authors: Popoola Olubunmi , Bamgbade Ayobami , Cao Yiding
Published: July 2016

An effective design option for a cooling system is to use a two-phase pumped cooling loop to simultaneously satisfy the temperature uniformity and high heat flux requirements. A reciprocating-mechanism driven heat loop (RMDHL) is a novel heat transfer device that could attain a high heat transfer rate through a reciprocating flow of the two-phase working fluid inside the heat transfer device. Although the device has been tested and validated experimentally, analytical or numerical study has not been undertaken to understand its working mechanism and provide guidance for the device design. The objective of this paper is to develop a numerical model for the RMDHL to predict its operational performance under different working conditions. The developed numerical model has been successfully validated by the existing experimental data and will provide a powerful tool for the design and performance optimization of future RMDHLs. The study also reveals that the maximum velocity in the flow occurs near the wall rather than at the center of the pipe, as in the case of unidirectional steady flow. This higher velocity near the wall may help to explain the enhanced heat transfer of an RMDHL.
Flexible RFID Tag Inductor Printed by Liquid Metal Ink Printer and Its Characterization
Authors: Gao Yunxia , Liu Rui , Wang Xianping , Liu Jing , Fang Qianfeng
Published: July 2016

In order to fulfill various growing needs of application fields, the development of low-cost directly printable radio-frequency identification (RFID) tag is essential for item level tracking. Currently, there lacks an easily available way to directly write out functional consumer electronicslike typewriting on paper by an office printer. Here, we show a desktop printing of RFID tag inductors on flexible substrates via developing liquid metal ink and related working mechanisms. The directly printing inductor on various flexible substrates with extremely low cost and rapid speed was designed based on the sympathetic oscillations of multiple LC (inductor–capacitor) circuits. In order to better meet the demands of the distinct resonant circuits, a series of conceptual experiments for investigating the relationship between the character of the inductor and its parameters—shape, number of coils, line width, spacing, etc.,—have been designed. The parameters are all working upon the performance of the printed inductors by liquid metal ink printer, and the relationship laws are consistent with those of the conventional inductors. The coils number as the biggest effect factor has a linear relationship with the inductance of the spiral-type inductors. An inductor with excellent properties can be well chosen by adjusting its parameters according to various applications. The present work demonstrated the way for a low cost and easy going method in directly printing RFID tag inductors on flexible substrates.
Rotordynamic Optimization of Fixed Pad Journal Bearings Using Response Surface Design of Experiments
Authors: Urbiola-Soto Leonardo , Santibañez-Santoscoy Raymundo , López-Parra Marcelo , Ramírez-Reivich Alejandro C. , Yañez-Valdez Ricardo
Published: July 2016

The design process of journal bearings of turbomachines is complex and time-consuming due to the many geometric and physical variables involved. This paper reports on the design of experiments (DOE) and the response surface design of experiments (RSDOE) methods employed on the design of the drive-end and free-end three-lobe journal bearings supporting a centrifugal compressor rotor. The suitability of each technique is discussed. The bearing design variables employed are bearing slenderness ratio, radial clearance, preload, and lubricant inlet temperature. The rotordynamic response variables selected were the critical speed location, the vibrations at critical speed and operating speed for both bearings, and the threshold speed of instability. The use of a nonlinear (quadratic) RSDOE model is justified. An optimization approach combining an SRDOE and rotordynamic finite element modeling is presented. This method leads to arrive to a multivariate model for multi-objective optimization with very few computations. Identification of the dominant design variables and their effects on several response variables allows establishing engineering feasible solutions with focus on manufacturing versus operating conditions tradeoff.
SU‐C‐204‐06: Monte Carlo Dose Calculation for Kilovoltage X‐Ray‐Psoralen Activated Cancer Therapy (X‐PACT): Preliminary Results
Authors: Mein S , Gunasingha R , Nolan M , Oldham M , Adamson J
Published: July 2016

Purpose:

X‐PACT is an experimental cancer therapy where kV x‐rays are used to photo‐activate anti‐cancer therapeutics through phosphor intermediaries (phosphors that absorb x‐rays and re‐radiate as UV light). Clinical trials in pet dogs are currently underway (NC State College of Veterinary Medicine) and an essential component is the ability to model the kV dose in these dogs. Here we report the commissioning and characterization of a Monte Carlo (MC) treatment planning simulation tool to calculate X‐PACT radiation doses in canine trials.

Methods:

FLUKA multi‐particle MC simulation package was used to simulate a standard X‐PACT radiation treatment beam of 80kVp with the Varian OBI x‐ray source geometry. The beam quality was verified by comparing measured and simulated attenuation of the beam by various thicknesses of aluminum (2–4.6 mm) under narrow beam conditions (HVL). The beam parameters at commissioning were then corroborated using MC, characterized and verified with empirically collected commissioning data, including: percent depth dose curves (PDD), back‐scatter factors (BSF), collimator scatter factor(s), and heel effect, etc. All simulations were conducted for N=30M histories at M=100 iterations.

Results:

HVL and PDD simulation data agreed with an average percent error of 2.42%±0.33 and 6.03%±1.58, respectively. The mean square error (MSE) values for HVL and PDD (0.07% and 0.50%) were low, as expected; however, longer simulations are required to validate convergence to the expected values. Qualitatively, pre‐ and post‐filtration source spectra matched well with 80kVp references generated via SPEKTR software. Further validation of commissioning data simulation is underway in preparation for first‐time 3D dose calculations with canine CBCT data.

Conclusion:

We have prepared a Monte Carlo simulation capable of accurate dose calculation for use with ongoing X‐PACT canine clinical trials. Preliminary results show good agreement with measured data and hold promise for accurate quantification of dose for this novel psoralen X‐ray therapy.

Funding Support, Disclosures, & Conflict of Interest: The Monte Carlo simulation work was not funded; Drs. Adamson & Oldham have received funding from Immunolight LLC for X‐PACT research.
SU‐C‐201‐05: Silicon Array Dosimeter in Situ with Electronic Portal Image Device for Simultaneous Transit Dose and Image Verification in Radiotherapy
Authors: Deshpande S , Alhujaili S , Vial P , Holloway L , Petasecca M , Rozenfeld A , Metcalfe P
Published: July 2016

Purpose:

To investigate an Electronic Portal Imaging Device (EPID) coupled to a 2D array dosimeter to provide simultaneous imaging and dose verification.

Methods:

The novel dual detector configuration comprised of a 2D diode array dosimeter, referred to as a Magic Plate (MP) placed directly on a standard EPID. Dose response of the MP was evaluated by measuring the detector's response with respect to off‐axis position and field size with 30 cm of solid water (SW) acting as a transit object in the beam. Measurements were performed with 3, 5, 10 and 15 mm SW build‐up and compared to 2D ionisation chamber array (ICA) measurements and the PinnacleTM treatment planning system (TPS) at a source to detector distance of 150 cm with a 6 MV beam. Clinical dosimetric performance was evaluated by measuring a number of intensity‐modulated radiation therapy (IMRT) beams in transit geometry. Imaging performance of the EPID was quantified by measuring the contrast‐to‐noise ratio (CNR) and spatial resolution. Images of a Rando phantom were used for qualitative assessment.

Results:

Measured MP off‐axis and field size response agreed within 2% of TPS and ICA responses when measured using 15 mm SW build‐up. Clinical IMRT beams had gamma pass rates of ≥95% at 3%/3mm criteria. Measured CNR and spatial resolution (f50) were 264.96, 210.6, and 0.41, 0.40 with build‐up of 5 and 15 mm respectively for the dual detector configuration. CNR and spatial resolution of 643.9 and 0.41 were measured for standard EPID. CNR was quantitatively worse in the dual detector configuration. Differences in imaging performance were not visible in a qualitative assessment using a Rando phantom.

Conclusion:

Combining a prototype MP 2D dosimeter with a conventional EPID did not significantly detract from the performance of either device and has the potential for simultaneous on‐line patient transit dosimetry and image assessment in radiation therapy.

Cancer Institute NSW Australia(Research Equipment Grant 10/REG/1‐20) and Cancer Council NSW (Grant ID RG 1‐06)
SU‐C‐207A‐03: Development of Proton CT Imaging System Using Thick Scintillator and CCD Camera
Authors: Tanaka S , Nishio T , Matsushita K , Tsuneda M , Kabuki S , Uesaka M
Published: July 2016

Purpose:

In the treatment planning of proton therapy, Water Equivalent Length (WEL), which is the parameter for the calculation of dose and the range of proton, is derived by X‐ray CT (xCT) image and xCT‐WEL conversion. However, about a few percent error in the accuracy of proton range calculation through this conversion has been reported. The purpose of this study is to construct a proton CT (pCT) imaging system for an evaluation of the error.

Methods:

The pCT imaging system was constructed with a thick scintillator and a cooled CCD camera, which acquires the two‐dimensional image of integrated value of the scintillation light toward the beam direction. The pCT image is reconstructed by FBP method using a correction between the light intensity and residual range of proton beam. An experiment for the demonstration of this system was performed with 70‐MeV proton beam provided by NIRS cyclotron. The pCT image of several objects reconstructed from the experimental data was evaluated quantitatively.

Results:

Three‐dimensional pCT images of several objects were reconstructed experimentally. A finestructure of approximately 1 mm was clearly observed. The position resolution of pCT image was almost the same as that of xCT image. And the error of proton CT pixel value was up to 4%. The deterioration of image quality was caused mainly by the effect of multiple Coulomb scattering.

Conclusion:

We designed and constructed the pCT imaging system using a thick scintillator and a CCD camera. And the system was evaluated with the experiment by use of 70‐MeV proton beam. Three‐dimensional pCT images of several objects were acquired by the system.

This work was supported by JST SENTAN Grant Number 13A1101 and JSPS KAKENHI Grant Number 15H04912.
SU‐C‐206‐04: Region‐Specific Total‐Variation Regularization for X‐Ray CT Reconstruction
Authors: Xu Q , Han H , Xing L
Published: July 2016

Purpose:

Total‐variation (TV) regularization methods are very effective to handle the non‐sufficient data reconstruction, such as few‐view problem, low‐dose data, etc. Usually one single regularization parameter is employed to balance the data fidelity and the TV minimization penalty in all regions of the object. However, noise and structural details vary from region to region. Here we proposed a method to select the regularization parameter adaptively by the region specific noise.

Methods:

The image was reconstructed by minimizing the data fidelity term and the TV term alternatively. After the image was updated by the data fidelity step, its noise distribution was estimated out by calculating the variance of neighboring pixels. Then a fuzzy clustering method was applied on it to proportionally assign the membership of each pixel into several clustering groups which correspond to regions with different noise levels, respectively. A heuristic function was developed to describe the relationship between the noise and the regularization parameter. The TV was performed under different parameters which were determined by the noise levels. The final image of TV minimization step was generated by fusing these results according to the weighting coefficients determined by the fuzzy membership. After that a new iteration was repeated until the stopping criterion was satisfied. A view down sampled human thorax dataset was used to evaluate the proposed method.

Results:

Since the noise distribution was not uniform, the conventional TV method with one single parameter cannot make a good balance between the noise and structural details in all regions simultaneously while the proposed region‐specific method can achieve a better result. The structure similarity index (SSIM) increased 2.1% and the root mean squared error (RMSE) decreased 9% in the vertebra region with comparable results in other regions.

Conclusion:

The proposed region specific regularization can improve the current TV‐based reconstruction.
SU‐C‐207B‐05: Tissue Segmentation of Computed Tomography Images Using a Random Forest Algorithm: A Feasibility Study
Authors: Polan D , Brady S , Kaufman R
Published: July 2016

Purpose:

Develop an automated Random Forest algorithm for tissue segmentation of CT examinations.

Methods:

Seven materials were classified for segmentation: background, lung/internal gas, fat, muscle, solid organ parenchyma, blood/contrast, and bone using Matlab and the Trainable Weka Segmentation (TWS) plugin of FIJI. The following classifier feature filters of TWS were investigated: minimum, maximum, mean, and variance each evaluated over a pixel radius of 2n, (n = 0–4). Also noise reduction and edge preserving filters, Gaussian, bilateral, Kuwahara, and anisotropic diffusion, were evaluated. The algorithm used 200 trees with 2 features per node. A training data set was established using an anonymized patient's (male, 20 yr, 72 kg) chest‐abdomen‐pelvis CT examination. To establish segmentation ground truth, the training data were manually segmented using Eclipse planning software, and an intra‐observer reproducibility test was conducted. Six additional patient data sets were segmented based on classifier data generated from the training data. Accuracy of segmentation was determined by calculating the Dice similarity coefficient (DSC) between manual and auto segmented images.

Results:

The optimized autosegmentation algorithm resulted in 16 features calculated using maximum, mean, variance, and Gaussian blur filters with kernel radii of 1, 2, and 4 pixels, in addition to the original CT number, and Kuwahara filter (linear kernel of 19 pixels). Ground truth had a DSC of 0.94 (range: 0.90–0.99) for adult and 0.92 (range: 0.85–0.99) for pediatric data sets across all seven segmentation classes. The automated algorithm produced segmentation with an average DSC of 0.85 ± 0.04 (range: 0.81–1.00) for the adult patients, and 0.86 ± 0.03 (range: 0.80–0.99) for the pediatric patients.

Conclusion:

The TWS Random Forest auto‐segmentation algorithm was optimized for CT environment, and able to segment seven material classes over a range of body habitus and CT protocol parameters with an average DSC of 0.86 ± 0.04 (range: 0.80–0.99).
SU‐D‐204‐01: A Methodology Based On Machine Learning and Quantum Clustering to Predict Lung SBRT Dosimetric Endpoints From Patient Specific Anatomic Features
Authors: Lafata K , Ren L , Wu Q , Kelsey C , Hong J , Cai J , Yin F
Published: July 2016

Purpose:

To develop a data‐mining methodology based on quantum clustering and machine learning to predict expected dosimetric endpoints for lung SBRT applications based on patient‐specific anatomic features.

Methods:

Ninety‐three patients who received lung SBRT at our clinic from 2011–2013 were retrospectively identified. Planning information was acquired for each patient, from which various features were extracted using in‐house semi‐automatic software. Anatomic features included tumor‐to‐OAR distances, tumor location, total‐lung‐volume, GTV and ITV. Dosimetric endpoints were adopted from RTOG‐0195 recommendations, and consisted of various OAR‐specific partial‐volume doses and maximum point‐doses. First, PCA analysis and unsupervised quantum‐clustering was used to explore the feature‐space to identify potentially strong classifiers. Secondly, a multi‐class logistic regression algorithm was developed and trained to predict dose‐volume endpoints based on patient‐specific anatomic features. Classes were defined by discretizing the dose‐volume data, and the feature‐space was zero‐mean normalized. Fitting parameters were determined by minimizing a regularized cost function, and optimization was performed via gradient descent. As a pilot study, the model was tested on two esophageal dosimetric planning endpoints (maximum point‐dose, dose‐to‐5cc), and its generalizability was evaluated with leave‐one‐out cross‐validation.

Results:

Quantum‐Clustering demonstrated a strong separation of feature‐space at 15Gy across the first‐and‐second Principle Components of the data when the dosimetric endpoints were retrospectively identified. Maximum point dose prediction to the esophagus demonstrated a cross‐validation accuracy of 87%, and the maximum dose to 5cc demonstrated a respective value of 79%. The largest optimized weighting factor was placed on GTV‐to‐esophagus distance (a factor of 10 greater than the second largest weighting factor), indicating an intuitively strong correlation between this feature and both endpoints.

Conclusion:

This pilot study shows that it is feasible to predict dose‐volume endpoints based on patient‐specific anatomic features. The developed methodology can potentially help to identify patients at risk for higher OAR doses, thus improving the efficiency of treatment planning.

R01‐184173
SU‐D‐BRB‐05: Quantum Learning for Knowledge‐Based Response‐Adaptive Radiotherapy
Authors: El Naqa I , Ten R
Published: July 2016

Purpose:

There is tremendous excitement in radiotherapy about applying data‐driven methods to develop personalized clinical decisions for real‐time response‐based adaptation. However, classical statistical learning methods lack in terms of efficiency and ability to predict outcomes under conditions of uncertainty and incomplete information. Therefore, we are investigating physics‐inspired machine learning approaches by utilizing quantum principles for developing a robust framework to dynamically adapt treatments to individual patient's characteristics and optimize outcomes.

Methods:

We studied 88 liver SBRT patients with 35 on non‐adaptive and 53 on adaptive protocols. Adaptation was based on liver function using a split‐course of 3+2 fractions with a month break. The radiotherapy environment was modeled as a Markov decision process (MDP) of baseline and one month into treatment states. The patient environment was modeled by a 5‐variable state represented by patient's clinical and dosimetric covariates. For comparison of classical and quantum learning methods, decision‐making to adapt at one month was considered. The MDP objective was defined by the complication‐free tumor control (P+=TCPx(1‐NTCP)). A simple regression model represented state‐action mapping. Single bit in classical MDP and a qubit of 2‐superimposed states in quantum MDP represented the decision actions. Classical decision selection was done using reinforcement Q‐learning and quantum searching was performed using Grover's algorithm, which applies uniform superposition over possible states and yields quadratic speed‐up.

Results:

Classical/quantum MDPs suggested adaptation (probability amplitude ≥0.5) 79% of the time for splitcourses and 100% for continuous‐courses. However, the classical MDP had an average adaptation probability of 0.5±0.22 while the quantum algorithm reached 0.76±0.28. In cases where adaptation failed, classical MDP yielded 0.31±0.26 average amplitude while the quantum approach averaged a more optimistic 0.57±0.4, but with high phase fluctuations.

Conclusion:

Our results demonstrate that quantum machine learning approaches provide a feasible and promising framework for real‐time and sequential clinical decision‐making in adaptive radiotherapy.
SU‐D‐BRA‐03: Analysis of Systematic Errors with 2D/3D Image Registration for Target Localization and Treatment Delivery in Stereotactic Radiosurgery
Authors: Xu H , Chetty I , Wen N
Published: July 2016

Purpose:

Determine systematic deviations between 2D/3D and 3D/3D image registrations with six degrees of freedom (6DOF) for various imaging modalities and registration algorithms on the Varian Edge Linac.

Methods:

The 6DOF systematic errors were assessed by comparing automated 2D/3D (kV/MV vs. CT) with 3D/3D (CBCT vs. CT) image registrations from different imaging pairs, CT slice thicknesses, couch angles, similarity measures, etc., using a Rando head and a pelvic phantom. The 2D/3D image registration accuracy was evaluated at different treatment sites (intra‐cranial and extra‐cranial) by statistically analyzing 2D/3D pre‐treatment verification against 3D/3D localization of 192 Stereotactic Radiosurgery/Stereotactic Body Radiation Therapy treatment fractions for 88 patients.

Results:

The systematic errors of 2D/3D image registration using kV‐kV, MV‐kV and MV‐MV image pairs using 0.8 mm slice thickness CT images were within 0.3 mm and 0.3° for translations and rotations with a 95% confidence interval (CI). No significant difference between 2D/3D and 3D/3D image registrations (P>0.05) was observed for target localization at various CT slice thicknesses ranging from 0.8 to 3 mm. Couch angles (30, 45, 60 degree) did not impact the accuracy of 2D/3D image registration. Using pattern intensity with content image filtering was recommended for 2D/3D image registration to achieve the best accuracy. For the patient study, translational error was within 2 mm and rotational error was within 0.6 degrees in terms of 95% CI for 2D/3D image registration. For intra‐cranial sites, means and std. deviations of translational errors were −0.2±0.7, 0.04±0.5, 0.1±0.4 mm for LNG, LAT, VRT directions, respectively. For extra‐cranial sites, means and std. deviations of translational errors were ‐ 0.04±1, 0.2±1, 0.1±1 mm for LNG, LAT, VRT directions, respectively. 2D/3D image registration uncertainties for intra‐cranial and extra‐cranial sites were comparable.

Conclusion:

The Varian Edge radiosurgery 6DOF‐based system, can perform 2D/3D image registration with high accuracy for target localization in image‐guided stereotactic radiosurgery.

The work was supported by a Research Scholar Grant, RSG‐15‐137‐01‐CCE from the American Cancer Society.