bluuebunny/crossref_metadata_2025 huggingface dataset:
A decoupled Crank-Nicolson time-stepping scheme for thermally coupled magneto-hydrodynamic system
Authors: Ravindran S. S.
Published: October 2017

Thermally coupled magneto-hydrodynamics (MHD) studies the dynamics of electro-magnetically and thermally driven flows,involving MHD equations coupled with heat equation. We introduce a partitioned method that allows one to decouplethe MHD equations from the heat equation at each time step and solve them separately. The extrapolated Crank-Nicolson time-stepping scheme is used for time discretizationwhile mixed finite element method is used for spatial discretization. We derive optimal order error estimates in suitable norms without assuming any stability condition or restrictions on the time step size. We prove the unconditional stability of the scheme. Numerical experiments are used to illustrate the theoretical results.
Discretization Based Heuristics for the Capacitated Multi-facility Weber Problem with Convex Polyhedral Barriers
Authors: Akyüz M. Hakan
Published: October 2017

The Capacitated Multi-facility Weber Problem addresses optimally locating I capacitated facilities in the plane and satisfying demand of J customers so as to minimize the total transportation cost. It assumes that facilities can be located anywhere on the plane and customers are directly connected to them. This study considers the case where there exist convex polyhedral barriers blocking passage and locating facilities inside. Then, the distances between facilities and customers have to be measured by taking into account the polyhedral barriers. The resulting problem is non-convex and difficult to solve. We propose several discretization based heuristic procedures which are especially designed for the problem. The performance of the suggested methods are tested on an extensive set of randomly generated test instances which are derived from standard test instances. Our results imply that the suggested heuristics yield very accurate and efficient solutions for this problem.
Modeling Time Variations of Boiler Efficiency
Authors: Rehan Ahmed , Habib Mohamed A. , Elshafei Moustafa , Alzaharnah Iyad T.
Published: October 2017

Boiler's efficiency is one of the important performance indicators of boiler. To keep track of operation cost, efficiency needs to be calculated with adequate accuracy by employing effective mathematical tools. In this work, a new modification in conventional mathematical formulation of efficiency is presented based on time-varying efficiency using time-varying operational variables of boiler. This modification was accomplished using indirect method of efficiency by applying experimental data of variables for certain time span. Moreover a second-order dynamic model of flue gas temperature (FGT) has been derived to construct the mathematical formulation of efficiency only in terms of available inputs. The resulting input–output-based model proved to be in quite agreement with efficiency calculated from experimental data. After modeling, influence of variations in air to fuel ratio (AFR) and fuel flow rate (FFR) upon efficiency has been discussed and it has been shown that time-varying efficiency covers deeper aspect of dynamic relation between efficiency and other input of boiler especially AFR and FFR. Moreover, it has been established that efficiency interacts with the dynamics of boiler, and in this respect, a dynamic relation between combustion process and boiler dynamics has been constructed via efficiency.
An In Vitro Experimental Study of the Pulse Delivery Method in Irreversible Electroporation
Authors: Zhang Bing , Moser Michael A. J. , Zhang Edwin M. , Xiang Jim , Zhang Wenjun
Published: October 2017

The purpose of this study was to investigate the feasibility of generating larger ablation volumes using the pulse delivery method in irreversible electroporation (IRE) using a potato model. Ten types of pulse timing schemes and two pulse repetition rates (1 pulse per 200 ms and 1 pulse per 550 ms) were proposed in the study. Twenty in vitro experiments with five samples each were performed to check the effects on the ablation volumes for the ten pulse timing schemes and two pulse repetition rates. At the two pulse repetition rates (1 pulse per 200 ms and 1 pulse per 550 ms), the largest ablation volumes achieved were 1634.1 mm3± 122.6 and 1828.4 mm3±160.9, respectively. Compared with the baseline approach (no pulse delays), the ablation volume was increased approximately by 62.8% and 22.6% at the repetition rates of 1 pulse per 200 ms and 1 pulse per 550 ms, respectively, using the pulse timing approach (with pulse delays). With the pulse timing approach, the ablation volumes generated at the lower pulse repetition rate were significantly larger than those generated at the higher pulse repetition rate (P < 0.001). For the experiments with one pulse train (baseline approach), the current was 5.2 A±0.4. For the experiments with two pulse trains, the currents were 6.4 A±0.9 and 6.8 A±0.9, respectively (P = 0.191). For the experiments with three pulse trains, the currents were 6.6 A±0.6, 6.9 A±0.6, and 6.5 A±0.6, respectively (P = 0.216). For the experiments with five pulse trains, the currents were 6.6 A±0.9, 6.9 A±0.9, 6.5 A±1.0, 6.5 A±1.0, and 5.7 A±1.2, respectively (P = 0.09). This study concluded that: (1) compared with the baseline approach used clinically, the pulse timing approach is able to increase the volume of ablation; but, the pulse timing scheme with the best performance might be various with the tissue type; (2) the pulse timing approach is still effective in achieving larger ablation volumes when the pulse repetition rate changes; but, the best pulse timing scheme might be different with the pulse repletion rate; (3) the current in the base line approach was significantly smaller than that in the pulse timing approach.
Investigation of Wave Characteristics in Oscillatory Motion of Partially Filled Rectangular Tanks
Authors: Ozbulut M. , Tofighi N. , Goren O. , Yildiz M.
Published: October 2017

Simulations of oscillatory motion in partially filled rectangular tanks with different tank geometries, fullness ratios, and motion frequencies are presented. Smoothed particle hydrodynamics (SPH) method is used to discretize the governing equations together with new velocity variance-based free surface (VFS) and artificial particle displacement (APD) algorithms to enhance the robustness and the accuracy of the numerical scheme. Two-dimensional (2D) oscillatory motion is investigated for three different scenarios where the first one scrutinizes the kinematic characteristics in resonance conditions, the second one covers a wave response analysis in a wide range of enforced motion frequencies, and the last one examines the dynamic properties of the fluid motion in detail. The simulations are carried on for at least 50 periods in the wave response analysis. It is shown that numerical results of the proposed SPH scheme are in match with experimental and numerical findings of the literature.
Neutron Imaging and Electrochemical Characterization of a Glucose Oxidase-Based Enzymatic Electrochemical Cell
Authors: Longchamps Ryan S. , van Zandt Zachary K. , Bilheux Hassina Z. , Dhiman Indu , Santodonato Louis J. , Ulyanova Yevgenia , Singhal Sameer , Nelson George J.
Published: October 2017

Enzymatic electrochemical cells (EECs) are a candidate for providing “green” solutions to a plethora of low-power, long-lifetime applications. A prototype three-electrode biobattery configuration of an EEC has been designed and fabricated for neutron imaging and electrochemical testing to characterize cell performance. The working electrode (WE) was catalyzed by a polymer ink-based biocatalyst with carbon felt (CF) serving as the supporting material. Results of both ex situ and in operando neutron imaging are presented as methods for relating fuel distribution, the distribution of the enzymes, and cell electrochemical performance. Neutron radiography (NR) was also performed on fuel solutions of varied concentrations to calibrate fuel solution thickness and allow for transient mapping of the fuel distribution. The calibration data proved useful in mapping the thickness of fuel solution during transient radiography. When refueled after electrochemical testing and neutron imaging, the cell surpassed its original performance, indicating that exposure to the neutron beam had not detrimentally affected enzyme activity. In operando mapping of the fuel solution suggests that increased wetting of the catalyst region increases cell performance. The relation of this performance increase to active region wetting is further supported by fuel distributions observed via the ex situ tomography. While useful in mapping aggregate solution wetting, the calibration data did not support reliable mapping of detailed glucose concentration in the WE. The results presented further demonstrate potential for the application of neutron imaging for the study of EECs, particularly with respect to mapping the distribution of aqueous fuel solutions.
Improvement of Thermo-Mechanical Reliability of Wafer-Level Chip Scale Packaging
Authors: Shi Lei , Chen Lin , Zhang David Wei , Liu Evan , Liu Qiang , Chen Ching-I
Published: October 2017

Due to low cost and good electrical performance, wafer-level chip scale packaging (WLCSP) has gained more attention in both industry and academia. However, because the coefficient of thermal expansion (CTE) mismatches between silicon and organic printed circuit board (PCB), WLCSP technology still faces reliability challenges, such as the solder joint fragile life issue. In this paper, a new WLCSP design (WLCSP-PN) is proposed, based on the structure of WLCSP with Cu posts (WLCSP-P), to release the stress on the solder joints. In the new design, there is a space between the Cu post and the polymer which permits NiSn coating on the post sidewall. The overcoating enhances the solder–post interface where cracks were initiated and enlarges the intermetallic compounds (IMC) joint area to enhance the adhesion strength. Design of experiment (DOE) with the Taguchi method is adopted to obtain the sensitivity information of design parameters of the new design by the three-dimensional (3D) finite element model (FEM), leading to the optimized configuration. The finite element analysis results demonstrate that compared to WLCSP-P, the proposed WLCSP-PN reduces the package displacement, equivalent stress, and plastic strain energy density and thus improves the fatigue life of solder joints.
Surface Roughness Impact on Low-Pressure Turbine Performance Due to Operational Deterioration
Authors: Kellersmann Andreas , Weiler Sarah , Bode Christoph , Friedrichs Jens , Städing Jörn , Ramm Günter
Published: October 2017

The overall efficiency and operational behavior of aircraft engines are influenced by the surface finish of the airfoils. During operation, the surface roughness significantly increases due to erosion and deposition processes. The aim of this study is to analyze the influence of roughness on the aerodynamics of the low-pressure turbine (LPT) of a midsized high bypass turbofan. In order to gain a better insight into the operational roughness structures, a sample of new, used, cleaned, and reworked turbine blades and vanes are measured using the confocal laser scanning microscopy technique. The measurement results show local inhomogeneities. The roughness distributions measured are then converted into their equivalent sand grain roughness ks,eq to permit an evaluation of the impact on aerodynamic losses. The numerical study is performed using the computational fluid dynamics (CFD)-solver turbomachinery research aerodynamics computational environment (TRACE) which was validated before with the existing data from rig experiments. It is observed that the influence of the surface roughness on the turbine efficiency is significant at take-off but negligible at cruise. A detailed analysis on the aerodynamics at take-off shows that very rough airfoils lead to higher profile and secondary loss. Due to the higher disturbances present in flows circulating over rough walls, the transition occurs earlier, and the momentum thickness increases in the turbulent boundary layer. The service-induced roughness structures cause an efficiency drop in the LPT of ηT=−0.16% compared to new parts. A gas path analysis showed that this results in an increased fuel flow of Δm˙f=+0.06% and an exhaust gas temperature (EGT) rise of ΔEGT=+1.2K for fixed engine pressure ratio which is equivalent to roughly 4% of the typical EGT margin of a fully refurbished engine. This result stresses the importance of roughness-induced loss in LPTs.
An Outflow Boundary Condition Model for Noninvasive Prediction of Fractional Flow Reserve in Diseased Coronary Arteries
Authors: Fayssal Iyad A. , Moukalled Fadl , Alam Samir , Isma'eel Hussain
Published: October 2017

This paper reports on a new boundary condition formulation to model the total coronary myocardial flow and resistance characteristics of the myocardial vascular bed for any specific patient when considered for noninvasive diagnosis of ischemia. The developed boundary condition model gives an implicit representation of the downstream truncated coronary bed. Further, it is based on incorporating patient-specific physiological parameters that can be noninvasively extracted to account for blood flow demand to the myocardium at rest and hyperemic conditions. The model is coupled to a steady three-dimensional (3D) collocated pressure-based finite volume flow solver and used to characterize the “functional significance” of a patient diseased coronary artery segment without the need for predicting the hemodynamics of the entire arterial system. Predictions generated with this boundary condition provide a deep understanding of the inherent challenges behind noninvasive image-based diagnostic techniques when applied to human diseased coronary arteries. The overall numerical method and formulated boundary condition model are validated via two computational-based procedures and benchmarked with available measured data. The newly developed boundary condition is used via a designed computational methodology to (a) confirm the need for incorporating patient-specific physiological parameters when modeling the downstream coronary resistance, (b) explain the discrepancies presented in the literature between measured and computed fractional flow reserve (FFRCT), and (c) discuss the current limitations and future challenges in shifting to noninvasive assessment of ischemia.
Exploring the Effects of a Product's Sustainability Triggers on Pro-Environmental Decision-Making
Authors: She Jinjuan , MacDonald Erin F.
Published: October 2017

The gap between consumers saying that they want and selecting sustainable products can be addressed through product design. Our previous research proposed a method for creating visible product features that trigger pro-environmental behavior in consumers, termed sustainability triggers (STs). The study below designed two experiments to mimic real-world decision scenarios and demonstrated that exposure to these STs caused pro-environmental behavior in two test versus control experiments. The experiments used both realistic prototypes and images of toasters. In experiment 1, a qualitative preference-elicitation method demonstrated that exposure to STs increased thoughts of sustainability—related decision criteria. In experiment 2, subjects' prioritization of “hidden” sustainability-related attributes, shipping method and energy usage, was higher if exposed to the STs. This was indicated by choice, information search, importance rating, and eye tracking. Thus, the novel design method to create product STs is demonstrated effective in the test case and has the potential to broadly benefit the success of sustainable products in the market.
Trailing Edge Perforation for Interaction Tonal Noise Reduction of a Contra-Rotating Fan
Authors: Wang Chen
Published: October 2017

This study focuses on a passive noise abatement technique in a small contra-rotating fan, aiming at reducing the interaction noise between the two rotors through porous trailing edge (TE) treatment to the forward rotor. A preliminary design with fixed perforation parameters is experimentally investigated, and 6–7 dB overall noise reduction is achieved compared with baseline design under the same aerodynamic output. A three-dimensional (3D), full-wheel, unsteady-flow numerical simulation of the acoustic design is carried out to better understand the noise reduction mechanism. Comparisons of monitored unsteady forces acting on both the forward and the aft rotor between baseline and perforated fan indicate that such treatment reduces all the unsteady forces. Thus, it can be concluded that the noise reduction would be due to not only the mitigation of viscous wake of forward rotor before impinging upon the downstream blades but also the reduction of the response of the upstream rotor to the potential flow interaction with the downstream rotor. Furthermore, a parametric study in a selected range is conducted to minimize the adverse effect of aerodynamic unloading due to TE perforation and to improve the acoustic benefit. The parameters in the parametric study include perforation ratio, aperture diameter, and perforation distribution. Trends are deducted from this, and it is recommended that there exists an optimal perforation ratio; the smallest possible aperture diameter and the decreasing perforation ratio distribution away from the blade TE should be selected in consideration of both aerodynamic and acoustic effects.
Conjugate Heat Transfer Analysis of Thermal Management of a Li-Ion Battery Pack
Authors: Chalise Divya , Shah Krishna , Prasher Ravi , Jain Ankur
Published: October 2017

Thermal management of Li-ion battery packs is a critical technological challenge that directly impacts safety and performance. Removal of heat generated in individual Li-ion cells into the ambient is a considerably complicated problem involving multiple heat transfer modes. This paper develops an iterative analytical technique to model conjugate heat transfer in coolant-based thermal management of a Li-ion battery pack. Solutions for the governing energy conservation equations for thermal conduction and convection are derived and coupled with each other in an iterative fashion to determine the final temperature distribution. The analytical model is used to investigate the dependence of the temperature field on various geometrical and material parameters. This work shows that the coolant flowrate required for effective cooling can be reduced significantly by improving the thermal conductivity of individual Li-ion cells. Further, this work helps understand key thermal–electrochemical trade-offs in the design of thermal management for Li-ion battery packs, such as the trade-off between temperature rise and energy storage density in the battery pack.
Ultrasound Shear Wave Elastography of the Elbow Ulnar Collateral Ligament: Reliability Test and a Preliminary Case Study in a Baseball Pitcher
Authors: Lin Che-Yu , Sadeghi Seyedali , Bader Dov A. , Cortes Daniel H.
Published: October 2017

Overhead throwing athletes are at high risk of the elbow ulnar collateral ligament (UCL) injury, and there is a need for clinical tools to objectively diagnose severity of injury and monitor recovery. Mechanical properties of ligaments can potentially be used as biomarkers of UCL health. The objectives of this study are to evaluate the reliability of shear wave ultrasound elastography (SWE) for quantifying UCL shear modulus in 16 healthy nonthrowing individuals and use this technique to evaluate the difference in UCL shear modulus between the injured and uninjured elbows in a baseball pitcher with UCL tear. In the reliability test, the UCL shear modulus of both elbows of each participant was evaluated by SWE for five trials. The same procedures were repeated on two different days. The intra-day and day-to-day reliabilities were determined by the five measurements on the first day and two averages on the two days, respectively. In the case study, each elbow of the baseball pitcher with UCL tear was tested for five trials, and the average was calculated. The intra-day (intraclass correlation coefficient (ICC) = 0.715, Cronbach's alpha = 0.926) and day-to-day (ICC = 0.948, Cronbach's alpha = 0.955) reliabilities were found to be good. There was no difference between both sides. In the case study, the UCL shear modulus of the injured elbow (186.45 kPa) was much lower than that of the uninjured elbow (879.59 kPa). This study shows that SWE could be a reliable tool for quantifying the mechanical properties and health status of the UCL.
Combining IVUS and Optical Coherence Tomography for More Accurate Coronary Cap Thickness Quantification and Stress/Strain Calculations: A Patient-Specific Three-Dimensional Fluid-Structure Interaction Modeling Approach
Authors: Guo Xiaoya , Giddens Don P. , Molony David , Yang Chun , Samady Habib , Zheng Jie , Mintz Gary S. , Maehara Akiko , Wang Liang , Pei Xuan , Li Zhi-Yong , Tang Dalin
Published: October 2017

Accurate cap thickness and stress/strain quantifications are of fundamental importance for vulnerable plaque research. Virtual histology intravascular ultrasound (VH-IVUS) sets cap thickness to zero when cap is under resolution limit and IVUS does not see it. An innovative modeling approach combining IVUS and optical coherence tomography (OCT) is introduced for cap thickness quantification and more accurate cap stress/strain calculations. In vivo IVUS and OCT coronary plaque data were acquired with informed consent obtained. IVUS and OCT images were merged to form the IVUS + OCT data set, with biplane angiography providing three-dimensional (3D) vessel curvature. For components where VH-IVUS set zero cap thickness (i.e., no cap), a cap was added with minimum cap thickness set as 50 and 180 μm to generate IVUS50 and IVUS180 data sets for model construction, respectively. 3D fluid–structure interaction (FSI) models based on IVUS + OCT, IVUS50, and IVUS180 data sets were constructed to investigate cap thickness impact on stress/strain calculations. Compared to IVUS + OCT, IVUS50 underestimated mean cap thickness (27 slices) by 34.5%, overestimated mean cap stress by 45.8%, (96.4 versus 66.1 kPa). IVUS50 maximum cap stress was 59.2% higher than that from IVUS + OCT model (564.2 versus 354.5 kPa). Differences between IVUS and IVUS + OCT models for cap strain and flow shear stress (FSS) were modest (cap strain <12%; FSS <6%). IVUS + OCT data and models could provide more accurate cap thickness and stress/strain calculations which will serve as basis for further plaque investigations.
Object Reorientation and Creative Performance
Authors: Oltețeanu A.-M. , Shu L. H.
Published: October 2017

Functional fixedness refers to a cognitive bias that prevents people from using objects in new ways and more abstractly from perceiving problems in new ways. Supporting people in overcoming functional fixedness could improve creative problem solving and capacities for creative design. A study was conducted to detect whether a relationship exists between participants' tendency to reorient objects presented as stimuli in an alternative uses test (AUT) and their creativity, also measured using the Wallach Kogan (WaKo) pattern meanings test. The AUT measures creativity as a function of identifying alternative uses for traditional objects. The WaKo pattern meanings test detects the ability to see an abstract pattern as different possible objects or scenes. Also studied is whether Kruglanski's need for closure (NFC) scale, a psychological measure, can predict the ability to incorporate reorientation cues when identifying uses. This study revealed highly significant, high correlations between reorientation and several creativity measures, and a correlation between reorientation and the predictability subscale of the NFC scale. A qualitative exploration of participants' responses reveals further metrics that may be relevant to assessing creativity in the AUT.
Fault-tolerant quantum error detection
Authors: Linke Norbert M. , Gutierrez Mauricio , Landsman Kevin A. , Figgatt Caroline , Debnath Shantanu , Brown Kenneth R. , Monroe Christopher
Published: October 2017

We show the fault-tolerant encoding, measurement, and operation of a logical qubit via quantum error detection.
The landscape of transcription errors in eukaryotic cells
Authors: Gout Jean-Francois , Li Weiyi , Fritsch Clark , Li Annie , Haroon Suraiya , Singh Larry , Hua Ding , Fazelinia Hossein , Smith Zach , Seeholzer Steven , Thomas Kelley , Lynch Michael , Vermulst Marc
Published: October 2017

This paper provides the first comprehensive analysis of the fidelity of transcription in eukaryotic cells.
Defect passivation of transition metal dichalcogenides via a charge transfer van der Waals interface
Authors: Park Jun Hong , Sanne Atresh , Guo Yuzheng , Amani Matin , Zhang Kehao , Movva Hema C. P. , Robinson Joshua A. , Javey Ali , Robertson John , Banerjee Sanjay K. , Kummel Andrew C.
Published: October 2017

Adsorption of organic molecules passivates defect states on single-layer MoS
2
via charge transfer.
Neonatal brain injuries in England: population-based incidence derived from routinely recorded clinical data held in the National Neonatal Research Database
Authors: Gale Chris , Statnikov Yevgeniy , Jawad Sena , Uthaya Sabita N , Modi Neena
Published: October 2017

Objective

In 2015, the Department of Health in England announced an ambition to reduce ‘brain injuries occurring during or soon after birth’. We describe the development of a pragmatic case definition and present annual incidence rates.

Design

Retrospective cohort study using data held in the National Neonatal Research Database (NNRD) extracted from neonatal electronic patient records from all National Health Service (NHS) neonatal units in England, Wales and Scotland. In 2010–2011, population coverage in the NNRD was incomplete, hence rate estimates are presented as a range; from 2012, population coverage is complete, and rates (95% CIs) are presented. Rates are per 1000 live births.

Setting

NHS neonatal units in England.

Patients

Infants admitted for neonatal care; denominator: live births in England.

Main outcome measure

‘Brain injuries occurring at or soon after birth’ defined as infants with seizures, hypoxic-ischaemic encephalopathy, stroke, intracranial haemorrhage, central nervous system infection and kernicterus and preterm infants with cystic periventricular leucomalacia.

Results

In 2010, the lower estimate of the rate of ‘Brain injuries occurring at or soon after birth’ in England was 4.53 and the upper estimate was 5.19; in 2015, the rate was 5.14 (4.97, 5.32). For preterm infants, the population incidence in 2015 was 25.88 (24.51, 27.33) and 3.47 (3.33, 3.62) for term infants. Hypoxic-ischaemic encephalopathy was the largest contributor to term brain injury, and intraventricular/periventricular haemorrhage was the largest contributor to preterm brain injury.

Conclusions

Annual incidence rates for brain injuries can be estimated from data held in the NNRD; rates for individual conditions are consistent with published rates. Routinely recorded clinical data can be used for national surveillance, offering efficiencies over traditional approaches.
Prevalence of blindness and cataract surgical coverage in Narayani Zone, Nepal: a rapid assessment of avoidable blindness (RAAB) study
Authors: Pradhan Sangita , Deshmukh Avnish , Giri Shrestha Puspa , Basnet Prajwal , Kandel Ram Prasad , Lewallen Susan , Sapkota Yuddha Dhoj , Bassett Ken , Yin Vivian T
Published: October 2017

Background

The 1981 Nepal Blindness Survey first identified the Narayani Zone as one of the regions with the highest prevalence of blindness in the country. Subseuqently, a 2006 survey of the Rautahat District of the Narayani Zone found it to have the country’s highest blindness prevalence. This study examines the impact on blind avoidable and treatable eye conditions in this region after significant increase in eye care services in the past decade.

Methods

The rapid assessment of avoidable blindness (RAAB) methodology was used with mobile data collection using the mRAAB smartphone app. Data analysis was done using the standard RAAB software. Based on the 2011 census, 100 clusters of 50 participants aged 50 years or older were randomly sampled proportional to population size.

Results

Of the 5000 participants surveyed, 4771 (95.4%) were examined. The age-adjusted and sex-adjusted prevalence of bilateral blindness, severe visual impairment (SVI) and moderate visual impairment (MVI) were 1.2% (95% CI 0.9% to 1.5%), 2.5% (95% CI 2.0% to -3.0%) and 13.2% (95% CI 11.8% to 14.5%), respectively. Cataract remains the primary cause of blindness and SVI despite cataract surgery coverage (CSC) of 91.5% for VA<3/60. Women still account for two-thirds of blindness.

Conclusion

The prevalence of blindness in people over the age of 50 years has decreased from 6.9% in 2006 to 1.2%, a level in keeping with the national average; however, significant gender inequity persists. CSC has improved but continues to favour men.
Macular imaging by optical coherence tomography in the diagnosis and management of glaucoma
Authors: Kim Ko Eun , Park Ki Ho
Published: October 2017

The macular area is important to the detection of glaucomatous retinal ganglion cell (RGC) damage. Macular thickness complementary to peripapillary retinal nerve fibre layer (RNFL) thickness can well reflect glaucomatous damage, given that the macula contains more than 50% of the RGCs in a multilayered pattern and larger RGC bodies compared with their axons. Thus, macular ganglion cell thickness parameters recently have been considered to be an effective glaucoma-diagnostic tool comparable to RNFL thickness parameters. Furthermore, spectral-domain optical coherence tomography ganglion cell–inner plexiform layer thickness and deviation maps can provide additional information essential for distinguishing glaucomatous changes from other, myopia-associated or macular disease-associated changes. Therefore, our aim with this study was to review the clinical application of macular imaging by optical coherence tomography and to provide essential clinical tips for its use in the diagnosis and management of glaucoma.
Electronic medical record alert improves HCV testing for baby boomers in primary care setting: adults born during 1945–1965
Authors: Al-hihi Eyad , Shankweiler Caylin , Stricklen David , Gibson Cheryl , Dunn Winston
Published: October 2017

Method

This project aims to implement the HCV birth cohort screening guidelines over a 9-month period in the primary care setting at the University of Kansas Health System General Internal Medicine Division.The project team measured the number of patients in the baby boomer population who received a one-time screen for HCV. An electronic medical record (EMR) intervention was implemented to identify baby boomers who did not have an HCV screening or diagnosis. Additionally, education was provided to all primary care providers in the clinic to increase awareness of the HCV birth cohort screening.

Results

The quality improvement methods increased the percentage of baby boomers who obtained a one-time screening test for HCV from a baseline of 30% to a 55% screening rate during the nine-month project period.

Conclusion

Identifying the HCV screening needs and creating a visual reminder in the EMR can be used to facilitate sustainable awareness and improvement of screening rates. The project team recognizes that continued work is required to close the HCV screening care gaps in the primary care setting.
Improving care collaboration for NICU patients to decrease length of stay and readmission rate
Authors: Welch Cherrie D , Check Jennifer , O’Shea T Michael
Published: October 2017

Background

Medically complex patients in neonatal intensive care units (NICUs) typically require long hospitalisations and care from multiple subspecialists. Scheduled multidisciplinary discussions could improve collaboration and continuity of care and thereby improve patient outcomes. The specific aims of the project were to decrease the average length of hospitalisation by at least 1 day and improve parent satisfaction ratings on a standard questionnaire by the end of our project’s first year, and to maintain a stable (or decreased) cause-related (30-day) readmission rate.

Methods

We designed a quality improvement project to enhance collaboration and continuity of care for medically complex infants cared for in the NICU of Brenner Children’s Hospital. Weekly multidisciplinary team meetings were held to discuss the long-term plan for patients who met specific criteria. Attendees included attending neonatologists, paediatric surgeons, a physical therapist, an occupational therapist, a speech therapist, a social worker, a nurse coordinator for palliative care, a family support coordinator, the NICU Nurse Manager, a hospital chaplain, mid-level providers, bedside nurses, a nurse quality improvement leader and the leaders and database manager for the quality improvement project. When needed for specific patients, a bioethicist was included.

Results

One year after implementing the project, the average duration of hospitalisation had decreased by 6.5 days. Cause-related readmission rates decreased from 3.33% to 0.95%. Parent satisfaction scores did not change significantly.

Conclusions

Weekly multidisciplinary meetings to coordinate and provide continuity of care for medically complex neonates in our NICU was associated with improved patient outcomes.
Fall-related mortality in southern Sweden: a multiple cause of death analysis, 1998–2014
Authors: Kiadaliri Aliasghar A , Rosengren Björn E , Englund Martin
Published: October 2017

Objectives

To investigate temporal trend in fall mortality among adults (aged ≥20 years) in southern Sweden using multiple cause of death data.

Methods

We examined all death certificates (DCs, n=2 01 488) in adults recorded in the Skåne region during 1998–2014. We identified all fall deaths using International Statistical Classification of Diseases (ICD)-10 codes (W00-W19) and calculated the mortality rates by age and sex. Temporal trends were evaluated using joinpoint regression and associated causes were identified by age-adjusted and sex-adjusted observed/expected ratios.

Results

Falls were mentioned on 1.0% and selected as underlying cause in 0.7% of all DCs, with the highest frequency among those aged ≥70 years. The majority (75.6%) of fall deaths were coded as unspecified fall (ICD-10 code: W19) followed by falling on or from stairs/steps (7.7%, ICD-10 code: W10) and other falls on the same level (6.3%, ICD-10 code: W18). The mean age at fall deaths increased from 77.5 years in 1998–2002 to 82.9 years in 2010–2014 while for other deaths it increased from 78.5 to 79.8 years over the same period. The overall mean age-standardised rate of fall mortality was 8.3 and 4.0 per 1 00 000 person-years in men and women, respectively, and increased by 1.7% per year in men and 0.8% per year in women during 1998–2014. Head injury and diseases of the circulatory system were recorded as contributing cause on 48.7% of fall deaths.

Conclusions

There is an increasing trend of deaths due to falls in southern Sweden. Further investigations are required to explain this observation particularly among elderly men.
Epidemiology of paediatric trauma presenting to US emergency departments: 2006–2012
Authors: Avraham Jacob B , Bhandari Misha , Frangos Spiros G , Levine Deborah A , Tunik Michael G , DiMaggio Charles J
Published: October 2017

Background

Traumatic injury is the leading cause of paediatric morbidity and mortality in the USA. We present updated national data on emergency department (ED) discharges for traumatic injury for a recent 7-year period.

Methods

We conducted a descriptive epidemiological analysis of the Nationwide Emergency Department Sample Survey, the largest and most comprehensive database in the USA, for 2006–2012. Among children and adolescents, we tracked changes in injury mechanism and severity, cost of care, injury intent and the role of trauma centres.

Results

There was an 8.3% (95% CI 7.7 to 8.9) decrease in the annual number of ED visits for traumatic injury in children and adolescents over the study period, from 8 557 904 (SE=5861) in 2006 to 7 846 912 (SE=5191) in 2012. The case-fatality rate was 0.04% for all injuries and 3.2% for severely injured children. Children and adolescents with high-mortality injury mechanisms were more than three times more likely to be treated at a level 1 trauma centre (OR=3.5, 95% CI 3.3 to 3.7), but were more no more likely to die (OR=0.96, 95% CI 0.93 to 1.00). Traumatic brain injury diagnoses increased 22.2% (95% CI 20.6 to 23.9) during the study period. Intentional assault accounted for 3% (SE=0.1) of all child and adolescent ED injury discharges and 7.2% (SE=0.3) of discharges among 15–19 year-olds. There was an 11.3% (95% CI 10.0 to 12.6) decline in motor vehicle injuries from 2009 to 2012. The total cost of care was $23 billion (SE=0.01), a 78% increase from 2006 to 2012.

Conclusions

This analysis presents a recent portrait of paediatric trauma across the USA. These analyses indicate the important role and value of trauma centre care for injured children and adolescents, and that the most common causes and mechanisms of injury are preventable.
T cell clonality assessment: past, present and future
Authors: Mahe Etienne , Pugh Tevor , Kamel-Reid Suzanne
Published: October 2017

T cell clonality testing has important clinical and research value, providing a specific and reproducible assessment of clonal diversity in T cell proliferations. Here we review the conceptual foundations of T cell clonality assays, including T cell ontogeny and T cell receptor structure and function; we also provide an introduction to T cell receptor genomics and the concept of the T cell clonotype. This is followed by a review of historical and current methods by which T cell clonality may be assayed, including current assay limitations. Some of these assay limitations have been overcome by employing next-generation sequencing (NGS)-based technologies that are becoming a mainstay of modern molecular pathology. In this vein, we provide an introduction to NGS technologies, including a review of the preanalytical, analytical and postanalytical technologies relevant to T cell clonality NGS assays.
Age–period–cohort analysis of trends in blood pressure and body mass index in children and adolescents in Hong Kong
Authors: Kwok Man Ki , Tu Yu Kang , Kawachi Ichiro , Schooling C Mary
Published: October 2017

Background

The declining or fluctuating trend in blood pressure (BP) despite the rising trend in body mass index (BMI) during childhood and adolescence is unexplained. We decomposed trends in BP and BMI to identify the relevance of early-life and contemporaneous factors.

Methods

We assessed the relative contribution of age, period and cohort to secular trends in BP in children and adolescents (9–18 years) from 1999 to 2014 and BMI (6–18 years) from 1996 to 2014 in Hong Kong, China.

Results

After accounting for age, period effects contributed more than cohort effects to the overall fluctuating BP trend and the rising BMI trend observed in this Chinese population. For both sexes, BP fell from the start of period to a low point in 2003–2005 but then rose. BMI rose strongly across the period before levelling off in 2009–2010. Earlier cohorts (born in 1983–1984) had higher BP and BMI than later cohorts.

Conclusion

With globalisation and associated lifestyle changes, successive generations of children and adolescents in a recently developed Chinese setting had lower BP and BMI, but this fall was offset until recently by population-wide increase in BMI. School-based health promotion efforts could have partly mitigated the population-wide rise in child and adolescent BMI, while socioeconomic transition or other factors could be relevant to changes in BP between generations. Explaining these trends will help identify early-life factors that may contribute to a healthier start as well as contemporaneous factors that may protect against rising trends in adiposity.
Acute convexity subarachnoid haemorrhage and cortical superficial siderosis in probable cerebral amyloid angiopathy without lobar haemorrhage
Authors: Charidimou Andreas , Boulouis Grégoire , Fotiadis Panagiotis , Xiong Li , Ayres Alison M , Schwab Kristin M , Gurol Mahmut Edip , Rosand Jonathan , Greenberg Steve M , Viswanathan Anand
Published: October 2017

Introduction

Acute non-traumatic convexity subarachnoid haemorrhage (cSAH) is increasingly recognised in cerebral amyloid angiopathy (CAA). We investigated: (a) the overlap between acute cSAH and cortical superficial siderosis—a new CAA haemorrhagic imaging signature and (b) whether acute cSAH presents with particular clinical symptoms in patients with probable CAA without lobar intracerebral haemorrhage.

Methods

MRI scans of 130 consecutive patients meeting modified Boston criteria for probable CAA were analysed for cortical superficial siderosis (focal, ≤3 sulci; disseminated, ≥4 sulci), and key small vessel disease markers. We compared clinical, imaging and cortical superficial siderosis topographical mapping data between subjects with versus without acute cSAH, using multivariable logistic regression.

Results

We included 33 patients with probable CAA presenting with acute cSAH and 97 without cSAH at presentation. Patients with acute cSAH were more commonly presenting with transient focal neurological episodes (76% vs 34%; p<0.0001) compared with patients with CAA without cSAH. Patients with acute cSAH were also more often clinically presenting with transient focal neurological episodes compared with cortical superficial siderosis-positive, but cSAH-negative subjects with CAA (76% vs 30%; p<0.0001). Cortical superficial siderosis prevalence (but no other CAA severity markers) was higher among patients with cSAH versus those without, especially disseminated cortical superficial siderosis (49% vs 19%; p<0.0001). In multivariable logistic regression, cortical superficial siderosis burden (OR 5.53; 95% CI 2.82 to 10.8, p<0.0001) and transient focal neurological episodes (OR 11.7; 95% CI 2.70 to 50.6, p=0.001) were independently associated with acute cSAH.

Conclusions

This probable CAA cohort provides additional evidence for distinct disease phenotypes, determined by the presence of cSAH and cortical superficial siderosis.
Longitudinal diffusion imaging across the C9orf72 clinical spectrum
Authors: Floeter Mary Kay , Danielian Laura E , Braun Laura E , Wu Tianxia
Published: October 2017

Introduction

Discrepancies between diffusion tensor imaging (DTI) findings and functional rating scales in amyotrophic lateral sclerosis (ALS) may be due to symptom heterogeneity, particularly coexisting cognitive-behavioural dysfunction affecting non-motor regions of the brain. Carriers of expansion mutations in the C9orf72 gene, whose motor and cognitive-behavioural symptoms span a range from ALS to frontotemporal dementia, present an opportunity to evaluate the relationship between symptom heterogeneity and DTI changes.

Methods

Twenty-eight C9orf72 mutation carriers with varied cognitive and motor symptoms underwent clinical evaluation and DTI imaging. Twenty returned for two or more follow-up evaluations. Each evaluation included motor, executive and behavioural scales and disease staging using the King’s college staging system.

Results

Widespread reduction of white matter integrity occurred in C9orf72 mutation carriers compared with 28 controls. The ALS Functional Rating Scale (ALSFRS-R) and King’s stage correlated with DTI measures of the corticospinal tract and mid-callosum. Cognitive and behavioural scores correlated with diffusion measures of frontal white matter. King’s stage, but not ALSFRS-R, correlated with anterior callosum DTI measures. Over a 6-month follow-up, DTI changes spread from anterior to posterior, and from deep to superficial subcortical white matter. In C9orf72 carriers with ALS or ALS-FTD, changes in corticospinal tractography measures correlated with changes in ALSFRS-R.

Conclusion

Discrepancies between DTI findings and clinical measures of disease severity in ALS may partly be accounted for by cognitive-behavioural deficits affecting extramotor white matter tracts. Both ALSFRS-R and King’s stage correlated with corticospinal DTI measures. Group-level DTI changes could be detected over 6 months.
Major incident triage and the implementation of a new triage tool, the MPTT-24
Authors: Vassallo James , Smith J E , Wallis L A
Published: October 2017

Introduction

The Modified Physiological Triage Tool (MPTT) is a recently developed primary triage tool and in comparison with existing tools demonstrates the greatest sensitivity at predicting need for life-saving intervention (LSI) within both military and civilian populations. To improve its applicability, we proposed to increase the upper respiratory rate (RR) threshold to 24 breaths per minute (bpm) to produce the MPTT-24. Our aim was to conduct a feasibility analysis of the proposed MPTT-24, comparing its performance with the existing UK Military Sieve.

Method

A retrospective review of the Joint Theatre Trauma Registry (JTTR) and Trauma Audit Research Network (TARN) databases was performed for all adult (>18 years) patients presenting between 2006–2013 (JTTR) and 2014 (TARN). Patients were defined as priority one (P1) if they received one or more LSIs. Using first recorded hospital RR in isolation, sensitivity and specificity of the ≥24 bpm threshold was compared with the existing threshold (≥22 bpm) at predicting P1 status. Patients were then categorised as P1 or not-P1 by the MPTT, MPTT-24 and the UK Military Sieve.

Results

The MPTT and MPTT-24 outperformed existing UK methods of triage with a statistically significant (p<0.001) increase in sensitivity of between 25.5% and 29.5%. In both populations, the MPTT-24 demonstrated an absolute reduction in sensitivity with an increase in specificity when compared with the MPTT. A statistically significant difference was observed between the MPTT and MPTT-24 in the way they categorised TARN and JTTR cases as P1 (p<0.001).

Conclusions

When compared with the existing MPTT, the MPTT-24 allows for a more rapid triage assessment. Both continue to outperform existing methods of primary major incident triage and within the military setting, the slight increase in undertriage is offset by a reduction in overtriage. We recommend that the MPTT-24 be considered as a replacement to the existing UK Military Sieve.
The ‘French exception’: the right to continuous deep sedation at the end of life
Authors: Horn Ruth
Published: October 2017

In 2016, a law came into force in France granting terminally ill patients the right to continuous deep sedation (CDS) until death. This right was proposed as an alternative to euthanasia and presented as the ‘French response’ to problems at the end of life. The law draws a distinction between CDS and euthanasia and other forms of sympton control at the end of life. France is the first country in the world to legislate on CDS . This short report describes the particular context and underlying social values that led to this piece of legislation, and explores its meaning in the wider French context.