bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparative Study of a Morphing Wing
Authors: Chae Eun Jung , Moosavian Amin , Pankonien Alexander M. , Inman Daniel J.
Published: November 2017

Along with recent advancements in novel materials and manufacturing processes, the interest in morphing wings has increased in order to further improve the aerodynamic performance of flying bodies. The morphing wing can be tailored to deliver superior performance, compared to its non-morphing counterparts, for multiple operating conditions and in varying flows. In particular, the morphing wing is implemented for drag reduction and lift enhancement, and hence, the maneuverability, adaptability, and capability of the morphing wing can encompass an even wider spectrum by changing the wing shape. In this research, an existing morphing UAV wing design, Spanwise Morphing Trailing Edge (SMTE), actuated by bending Macro Fiber Composites (MFCs), is considered to generate the spanwise sinusoidal variations on the trailing edge of the morphing wing. A comparative aerodynamic study of the morphing wing by varying the spatial frequency (i.e., number of waves along the span) and the phase shift (i.e., wave shape along the span) at different angles of attack is conducted through analytical approaches and numerical Computational Fluid Dynamic (CFD) simulations, which are validated with previous experimental measurements. The analytical approach uses the three-dimensional (3D) Prandtl lifting line theory, and the CFD modeling in turbulence flow solves the 3D Reynolds-Averaged Navier-Stokes (RANS) equations with the k-ω Shear Stress Transport (SST) turbulence model. Note that the numerical simulations of a morphing wing focus on the pre-stall condition to estimate the aerodynamic performance. This work extends a prior study about a nominal flight condition testing a morphing wing at multiple flight conditions to evaluate multi-point 1 performance. The results show that there are governing aerodynamic efficiency zones of the lift-to-drag ratio, endurance, and aircraft range within a zone of angles of attack. Therefore, the morphing wing is shown to have a good aerodynamic performance as compared to the non-morphing wing.
High Temperature Characterization of Fiber Bragg Grating Sensors Embedded Into Metallic Structures Through Ultrasonic Additive Manufacturing
Authors: Schomer John J. , Dapino Marcelo J.
Published: November 2017

Embedded fiber Bragg grating (FBG) sensors are attractive for in-situ structural monitoring, especially in fiber reinforced composites. Their implementation in metallic structures is hindered by the thermal limit of the protective coating, typically a polymer material. The purpose of this study is to demonstrate the embedding of FBG sensors into metals with the ultimate objective of using FBG sensors for structural health monitoring of metallic structures. To that end, ultrasonic additive manufacturing (UAM) is utilized. UAM is a solid-state manufacturing process based on ultrasonic metal welding that allows for layered addition of metallic foils without melting. Embedding FBGs through UAM is shown to result in total cross-sectional encapsulation of the sensors within the metal matrix, which encourages uniform strain transfer. Since the UAM process takes place at essentially room temperature, the industry standard acrylate protective coating can be used rather than requiring a new coating applied to the FBGs prior to embedment. Measurements presented in this paper show that UAM-embedded FBG sensors accurately track strain at temperatures higher than 400 °C. The data reveals the conditions under which detrimental wavelength hopping takes place due to non-uniformity of the load transferred to the FBG. Further, optical cross-sectioning of the test specimens shows inhibition of the thermal degradation of the protective coating. It is hypothesized that the lack of an atmosphere around the fully-encapsulated FBGs makes it possible to operate the sensors at temperatures well above what has been possible until now. Embedded FBGs were shown to retain their coatings when subjected to a thermal loading that would result in over 50 percent degradation (by volume and mass) in atmospherically exposed fiber.
3D-Printed Conductive Nanocomposites for Liquid Sensing Applications
Authors: Aliheidari Nahal , Hohimer Cameron , Ameli Amir
Published: November 2017

Additive manufacturing (AM) offers a new and unique method for the fabrication of functional and smart material and structures. In this method, parts are fabricated directly from a 3D computer model layer by layer. Fused deposition modeling (FDM) is the most widely adapted AM method. In this method, the feedstock is usually a thermoplastic-based material. In recent years, flexible smart materials have gained unflagging interests due to their promising applications in health monitoring, sensing, actuation, etc. However, the 3D printing of flexible materials is recent with its own challenges and limited sources of feedstock.

Conductive polymer nanocomposites (CPNs) have many promising uses within sensing filed including liquid sensing. Sensing chemical leakage is one the important capabilities of liquid sensors. There is a good number of studies on the fabrication and sensitivity characterization of CPN-based liquid sensors. However, the sensitivity and response time of CPN-based liquid sensors do not yet meet the industrial demands and should be further enhanced for their practical and widespread applications.

This study presents an attempt to integrate the tunability of CPN’s conductivity behavior and the design flexibility of 3D printing to explore the benefits that their coupling may offer toward more sensitive and/or faster liquid sensing. Thermoplastic polyurethane/multiwalled carbon nanotube (TPU/MWCNT) nanocomposites were selected as a model material system and their filaments were first fabricated using melt-mixing by twin-screw extruder at 1, 2 and 3 wt.% of MWCNT. Flexible U-shaped TPU/MWCNT specimens were designed and successfully 3D-printed as a liquid sensor. Specimens fabricated at three different raster patterns of linear, 0–90, and 45/−45 and three infill percent levels of 100, 75, and 50%. Ethanol was used as the model chemical and the resistivity change of the sensors was measured as a function of time when immersed in ethanol. The results revealed that the printed sensors greatly outperformed the pressed bulk counterparts. This enhancement in the 3D printed sensors was primarily due to the increased surface area, and thus higher surface/volume ratio, enabling faster liquid uptake. In addition, MWCNT content, raster pattern, and infill percent all affected the overall response time as well as the sensor sensitivity. This work suggests that highly sensitive liquid sensors can be developed by material and structure optimizations via FDM 3D printing.
Internal Porosity Detection in Additively Manufactured Parts via Electromechanical Impedance Measurements
Authors: Tenney Charles , Albakri Mohammad I. , Kubalak Joseph , Sturm Logan D. , Williams Christopher B. , Tarazaga Pablo A.
Published: November 2017

The flexibility offered by additive manufacturing (AM) technologies to fabricate complex geometries poses several challenges to non-destructive evaluation (NDE) and quality control (QC) techniques. Existing NDE and QC techniques are not optimized for AM processes, materials, or parts. Such lack of reliable means to verify and qualify AM parts is a significant barrier to further industrial adoption of AM technologies.

Electromechanical impedance measurements have been recently introduced as an alternative solution to detect anomalies in AM parts. With this approach, piezoelectric wafers bonded to the part under test are utilized as collocated sensors and actuators. Due to the coupled electromechanical characteristics of piezoelectric materials, the measured electrical impedance of the piezoelectric wafer depends on the mechanical impedance of the part under test, allowing build defects to be detected. This paper investigates the effectiveness of impedance-based NDE approach to detect internal porosity in AM parts. This type of build defects is uniquely challenging as voids are normally embedded within the structure and filled with unhardened model or supporting material. The impact of internal voids on the electromechanical impedance of AM parts is studied at several frequency ranges.
Acoustoelastic-Based Stress Measurement Utilizing Low-Frequency Flexural Waves
Authors: Albakri Mohammad I. , Malladi Vijaya V. N. Sriram , Tarazaga Pablo A.
Published: November 2017

Current acoustoelastic-based stress measurement techniques operate at the high-frequency, weakly-dispersive portions of the dispersion curves. The weak dispersive effects at such high frequencies allow the utilization of time-of-flight measurements to quantify the effects of stress on wave speed. However, this comes at the cost of lower sensitivity to the state-of-stress of the structure, and hence calibration at a known stress state is required to compensate for material and geometric uncertainties in the structure under test.

In this work, the strongly-dispersive, highly stress-sensitive, low-frequency flexural waves are utilized for stress measurement in structural components. A new model-based technique is developed for this purpose, where the acoustoelastic theory is integrated into a numerical optimization algorithm to analyze dispersive waves propagating along the structure under test. The developed technique is found to be robust against material and geometric uncertainties. In the absence of calibration experiments, the robustness of this technique is inversely proportional to the excitation frequency. The capabilities of the developed technique are experimentally demonstrated on a long rectangular beam, where reference-free, un-calibrated stress measurements are successfully conducted.
Thermo-Electromechanical Response of Polymer-Bonded Explosives for Structural Health Monitoring of Energetic Materials
Authors: Rocker Samantha N. , Pearrell T. Wade , Sengezer Engin C. , Seidel Gary D.
Published: November 2017

Distributing a carbon nanotube sensing network throughout the binder phase of energetic composites is investigated in an effort for real time embedded sensing of localized heating in polymer bonded explosives (PBXs) through thermo-electromechanical response for in situ structural health monitoring (SHM) in energetic materials. The experimental effort herein is focused on using 70 wt% Ammonium Perchlorate (AP) (solid oxidizer used in solid rocket propellants) crystals embedded into epoxy binder having concentration of 0.1 wt% multi-walled carbon nanotubes (MWCNTs) relative to entire hybrid energetics. Electrical and dielectric properties of neat (i.e. no MWCNTs) energetics and MWCNT hybrid energetics are quantitatively and qualitatively evaluated under localized thermal loading. Electrical and dielectric properties showed variations for both neat energetics and MWCNT hybrid energetics depending on input frequency measurements. Significant thermo-electromechanical response was obtained for MWCNT AP hybrid energetics, providing a proof of concept for thermo-electromechanical sensing for realtime SHM in energetics.
Design of Disordered Periodic Structures for Mode Localization
Authors: Cazzulani Gabriele , Riva Emanuele , Belloni Edoardo , Braghin Francesco
Published: November 2017

Periodic structures are the repetition of unit cells in space, that provide a filtering behavior for wave propagation. In particular, it is possible to tailor the geometrical, physical and elastic properties of the unit cells, in order to attenuate certain frequency bands, called band-gaps or stop-bands. Having each element characterized with the same parameters, the filtering behavior of the system can be described through the wave propagation properties of the unit cell. This is technologically impossible to obtain, therefore the Lyapunov factor is used, in order to define the mean attenuation of a quasi-periodic structure. Tailoring Gaussian unit cell properties potentially allows to extend the stop-bands width in the frequency domain. A drawback is that some unexpected resonance peaks may lie in the neighborhood of the extended regions. However, the correspondent mode-shapes are localized in a particular region of the structure, and they partially decrease the global attenuating behavior. In this paper, the aperiodicity introduced in the otherwise perfect repetition is investigated, providing an explanation for the mode-localization problem and for the stop-bands extension. Then, the proposed approach is applied to a passive quasi-periodic beam, characterized from a localized peak within a designed band-gap. The geometrical properties of its aperiodic parts are changed in order to deterministically move the localization peak in the frequency response. Numerical and experimental results are compared.
Experimental Evaluation of Sensing and Energy Harvesting Behavior of Implanted Piezoelectric Transducers in Total Knee Replacement
Authors: Safaei Mohsen , Anton Steven R.
Published: November 2017

Total knee replacement has been utilized to restore the functionality of diseased knee joints for more than four decades. Today, despite the relatively high level of patient satisfaction, still about 20% of patients are not fulfilled with their surgical outcomes in terms of function and reduction in pain. There is still an ongoing discussion on correlating the postoperative functionality of the joint to intraoperative alignment, which suffers from lack of in vivo data from the knee after surgery. However, it is necessary to mention that using computer assisted surgical techniques, the outcomes of knee replacement procedures have been remarkably improved. In order to obtain information about the knee function after the operation, the design of a self-powered instrumented knee implant is proposed in this study. The design is a total knee replacement ultra high molecular weight polyethylene insert equipped with four piezoelectric transducers distributed in the medial and lateral compartments of the bearing. The piezoelectric elements are employed to measure the axial force applied on the tibial insert through the femoral component of the joint as well as to track the movement in the center of pressure. In addition, generated voltage from the piezoelectrics is harvested and stored to power embedded electronics for further signal conditioning and data transmitting purposes. The performance of the instrumented implant is investigated via experimental testing on a fabricated prototype in terms of sensing and power harvesting capacity. Piezoelectric force and center of pressure measurements are compared to the actual quantities recorded from the load frame and pressure sensitive films in order to evaluate the performance of the sensing system. The output voltage of the piezoelectric transducers is rectified and stored in a capacitor to evaluate the energy harvesting ability of the system. The results show only a small level of error in sensing the force and the location of center of pressure. Additionally, a 4.9 V constant voltage is stored in a 3.3 mF capacitor after 3333 loading cycles. The sensing and energy harvesting results present the promising potential of this system to be used as an integrated self-powered instrumented knee implant.
Modeling and Experimental Verification of the Aeroelastic Behavior of a Typical Airfoil Section With Shape Memory Alloy Springs
Authors: Sousa Vagner Candido de , Silva Tarcísio Marinelli Pereira da , De Marqui Carlos
Published: November 2017

This paper presents the modeling, simulation and wind tunnel experimental verification of the aeroelastic behavior of a two-degree-of-freedom (pitch and plunge) typical airfoil section with superelastic shape memory alloy helical springs in the pitch degree-of-freedom. A linearly elastic spring is considered in the plunge degree-of-freedom. Although viscous damping is considered in both degrees-of-freedom, hysteretic damping simultaneously takes place in the pitch degree-of-freedom due to the (stress-induced) pseudoelastic behavior of the shape memory alloy springs. The shape memory alloy phase transformation kinetics and constitutive modeling are based on Brinsons model and the shape memory alloy helical spring behavior is based on classical spring design. The nonlinear effects of shape memory alloy phase transformation are included in the shape memory alloy spring modeling for the representation of hysteretic force-displacement behavior. A two-state linear aerodynamic model is employed to determine the unsteady pitching moment and lift. The aeroelastic behavior of the typical section is numerically and experimentally investigated for different preload levels applied to the shape memory alloys. Numerical predictions and experimental results show that for large enough preload levels (such that shape memory alloy phase transformations take place at small pitch angles) unstable post-flutter regime is replaced by stable limit-cycle oscillations. Moreover, the amplitudes of aeroelastic oscillations decrease with increasing preload levels since more expressive phase transformations are achieved at small pitch angles. Although the amplitudes of the post-flutter limit-cycle oscillations increase with increasing airflow speed (since aerodynamic loads increase with the square of the airflow speed), they remain bounded within acceptable levels over a range of airflow speeds due to hysteretic damping. Moreover, the cutoff airflow speed increases with increasing preload. The experimentally verified results show that the pseudoelastic behavior of shape memory alloy elements can passively enhance the aeroelastic behavior of a typical section.
Resonant Nonlinearities of Macro-Fiber Composite Cantilevers in Energy Harvesting
Authors: Tan David , Yavarow Paul , Erturk Alper
Published: November 2017

We explore the modeling and analysis of nonlinear non-conservative dynamics of macro-fiber composite (MFC) piezo-electric structures, guided by rigorous experiments, for resonant vibration-based energy harvesting, as well as other applications leveraging the direct piezoelectric effect, such as resonant sensing. The MFCs employ piezoelectric fibers of rectangular cross section embedded in kapton with interdigitated electrodes to exploit the 33-mode of piezoelectricity. Existing frameworks for resonant nonlinearities have so far considered conventional piezoceramics that use the 31-mode of piezoelectricity. In the present work, we develop a framework to represent and predict nonlinear electroelastic dynamics of MFC bimorph cantilevers under resonant base excitation. The interdigitated electrodes are shunted to a set of resistive electrical loads to quantify the electrical power output. Experiments are conducted on a set of MFC bimorphs over a broad range of mechanical excitation levels to identify the types of nonlinearities present and to compare the model predictions and experiments. The experimentally observed interaction of material softening and geometric hardening effects, as well as dissipative effects, is captured and demonstrated by the model.
Mechanics of NiTi Reinforced Self-Healing Materials Producing Crack Closing Loads
Authors: Salowitz Nathan , Correa Ameralys , Moghadam Afsaneh
Published: November 2017

Self-healing material structures with the inherent capability to mend damage will lead to a paradigm shift in design as fracture may no longer constitute a failure. Generally, there are two techniques of self-healing that operate at different scales, require different approaches and often are dealt with separately; geometric restoration and crack filling/bonding. Geometric restoration uses shape memory materials that can mechanically close fractures after they occur. Crack filling and bonding fills and chemically bonds fractured parts in place.

Materials capable of recovering from complete fractures, that have propagated across the entire component, have typically taken a sparse fiber composite form with a structural matrix encapsulating shape memory fibers. This form of self-healing material has demonstrated the ability recover original bulk geometry. However, lacking bonding, the healed structures have not had the ability to resist subsequent externally applied loads without re-opening the crack.

A new approach of pre-straining the shape memory fibers before curing them in a matrix in the pre-strained state is presented in this paper with basic theory and experimental results. Pre-straining the shape memory fibers before casting them in the matrix causes them to undergo constrained recovery upon activation. Thus, the samples create closing loads across the crack which are capable of withstanding external loads without re-opening.
Biodiversity recovery following delta-wide measures for flood risk reduction
Authors: Straatsma Menno W. , Bloecker Alexandra M. , Lenders H. J. Rob , Leuven Rob S. E. W. , Kleinhans Maarten G.
Published: November 2017

We show that biodiversity recovery was successfully combined with flood risk reduction interventions at the river delta scale.
Environmental controls on modern scleractinian coral and reef-scale calcification
Authors: Courtney Travis A. , Lebrato Mario , Bates Nicholas R. , Collins Andrew , de Putron Samantha J. , Garley Rebecca , Johnson Rod , Molinero Juan-Carlos , Noyes Timothy J. , Sabine Christopher L. , Andersson Andreas J.
Published: November 2017

In situ coral calcification was primarily controlled by temperature and relatively insensitive to seawater CO
2
chemistry.
Intraoceanic subduction spanned the Pacific in the Late Cretaceous–Paleocene
Authors: Domeier Mathew , Shephard Grace E. , Jakob Johannes , Gaina Carmen , Doubrovine Pavel V. , Torsvik Trond H.
Published: November 2017

Intraoceanic subduction drove both the Pacific plate’s ~80- to 47-Ma northward motion and its redirection at ~47 Ma.
Pushing the limits of photoreception in twilight conditions: The rod-like cone retina of the deep-sea pearlsides
Authors: de Busserolles Fanny , Cortesi Fabio , Helvik Jon Vidar , Davies Wayne I. L. , Templin Rachel M. , Sullivan Robert K. P. , Michell Craig T. , Mountford Jessica K. , Collin Shaun P. , Irigoien Xabier , Kaartvedt Stein , Marshall Justin
Published: November 2017

Deep-sea fishes evolved an unconventional visual system to optimize vision in twilight conditions.
Giant radio telescope lends a hand in Puerto Ricorelief
Authors: Clery Daniel
Published: November 2017

Its own fate in question, the Arecibo Observatory aids communities after
hurricane
New tools offer clues to how the human brain takes shape
Authors: Gibbons Ann
Published: November 2017

Minibrains and gene studies hint at what makes humans special
Genomes rewrite cholera's global story
Authors: Kupferschmidt Kai
Published: November 2017

Epidemics in Africa and the Americas originate in Asia, a new study finds
Observation of mean path length invariance in light-scattering media
Authors: Savo Romolo , Pierrat Romain , Najar Ulysse , Carminati Rémi , Rotter Stefan , Gigan Sylvain
Published: November 2017

Scattered light, it is all the same

Materials can vary from transparent to opaque depending on the density of scatters within the medium. As light propagates through a material, intuition might suggest that the more scatters there are, the shorter the path along which the light can propagate. Savo
et al.
confirm a recent theoretical proposal that predicts that this is not the case. They shone light through a series of samples of varying scatterer density and found that the average path length that the light traveled was independent of the sample microstructure. This finding should also be applicable to acoustics and matter waves.

Science
, this issue p.
765
Response to Comment on “The extent of forest in dryland biomes”
Authors: Bastin J.-F. , Mollicone D. , Grainger A. , Sparrow B. , Picard N. , Lowe A. , Castro R.
Published: November 2017

De la Cruz
et al
. question the reliability of our results, claiming that we do not refer to the most appropriate spatial extent of drylands. In our response, we explain why we chose an existing and internationally recognized delineation of drylands among several options, and why our findings are due to a difference of remote sensing technique and not to the definition of drylands we have selected.
Cell cycle proteins moonlight in multiciliogenesis
Authors: Levine Michelle , Holland Andrew
Published: November 2017

Proteins that control cell cycle progression also drive multiciliated cell differentiation
A trove of biodiversity, at risk
The Lost Species
Christopher Kemp
University of Chicago Press, 2017. 272 pp.
Authors: Styles Bonnie
Published: November 2017

With funding for museum collections in peril, new species await discovery and names that may never come
Small media, big impact
Authors: Gentzkow Matthew
Published: November 2017

Randomizing news stories reveals broad public impacts
Latent Membrane Protein 1 Is a Novel Determinant of Epstein-Barr Virus Genome Persistence and Reactivation
Authors: Caves Elizabeth A. , Butch Rachel M. , Cook Sarah A. , Wasil Laura R. , Chen Chen , Di Yuanpu Peter , Lee Nara , Shair Kathy H. Y.
Published: November 2017

Latent membrane protein 1 (LMP1) is a constitutively active oncogenic signaling protein encoded by Epstein-Barr virus (EBV). Despite monoclonal infection in cases of nasopharyngeal carcinoma (NPC), it has been difficult to reconcile the heterogeneous LMP1 protein levels detected in tumor cells. The LMP1 protein is a pleiotropic signaling protein with oncogenic potential. Findings from this study are consistent with the hypothesis that LMP1 has a role distinct from that of oncogenesis that facilitates the viral life cycle by promoting an unstable but productive infection in differentiating epithelia.
Migration of ventriculoperitoneal shunt to urethral and rectal orifices
Authors: Osman Banan , Roushias Stella , Hargest Rachel , Narahari Krishna
Published: November 2017

Ventriculoperitoneal (VP) shunt surgery remains the most widely used neurosurgical procedure for the management of hydrocephalus. However, shunt complications are common and may require multiple surgical procedures during a patient’s lifetime. We report the case of a 29-year-old patient with a background of Dandy-Walker malformation, occipital encephalocele, recurrent hydrocephalus, spina bifida and epilepsy presented with VP shunt migration into urinary and gastrointestinal tracts. In absence of sepsis or peritonism from either bowel or bladder perforation, local control of stent extrusion was successful for several years, although surgery was eventually undertaken.
Persistent bacteraemia caused byStaphylococcus aureusin the gall bladder
Authors: Yu Alexander Tin Han , Cun Tony , Benamu Esther , Renault Cybele
Published: November 2017

Staphylococcus aureusbacteraemia (SAB) remains a complex disease with a high associated morbidity and mortality, especially when it is able to establish an occult nidus safe from antimicrobial eradication. Without rapid identification and intervention, the nidus can cause persistent relapse of disease, morbidity and mortality. Having a high clinical suspicion for the foci of occultS. aureusis important, and awareness of potential sites of infection is critical and can be life-saving.

We present a unique case of a 65-year-old man with end-stage renal disease receiving haemodialysis who developed septic shock from SAB. Despite 18 days of appropriate antibiotics, the patient had persistent high-grade bacteraemia until his gall bladder was ultimately percutaneously drained. The day after drainage, he cleared his blood cultures, although he ultimately passed away as he decided to transition his care to focus on comfort measures.
Polymyalgia rheumatica development in a patient under PI3K inhibitor therapy for chronic lymphocytic leukaemia
Authors: Sajawal Sanah , Mackie Sarah L , Hillmen Peter , McGonagle Dennis
Published: November 2017

We report a patient with chronic lymphocytic leukaemia (CLL) who was treated with idelalisib, a PI3Kδ inhibitor with rituximab. After 20 weeks of treatment, the patient developed classical signs and symptoms of polymyalgia rheumatica (PMR) in association with an elevated C reactive protein of 74 mg/L. After 2 weeks of prednisolone 15 mg daily symptoms had resolved and acute phase markers normalised. To our knowledge, this is the first report of PMR developing as a complication of PI3Kδ inhibitor treatment of CLL.
Developing a classification system for haemoglobin management in patients with end-stage renal disease on haemodialysis: a secondary data analysis
Authors: Kesztyüs Tibor , Simonsmeier Ulrich , Kesztyüs Dorothea
Published: November 2017

Background

Ongoing discussion on anaemia management and target haemoglobin (Hb) levels in patients on haemodialysis with erythropoietin treatment require a systematic approach in evaluating current practice. Aim of the present study was to develop a new classification system to easily monitor Hb trajectories and categorise patients on haemodialysis.

Methods

Routine data from five dialysis centres in the USA collected between 2010 and 2016. Data were anonymised and only those from patients with fortnightly Hb values were included in the analysis. Entries on blood parameters and medication were standardised to achieve overall comparability. Data from each patient was grouped in periods of 120 days. Hb values above or below the target level of 10–12 g/dL were counted for each period. Periods were then assigned to Hb-classes according to the number of Hb values out of range per period: Hb-class I with 0–2, Hb-class II for 3–5 and Hb-class III for ≥6 values out of range.

Results

Records from 3349 patients with fortnightly Hb values, information on haemodialysis data, laboratory parameters correlated to red blood cells and data on medication with erythropoiesis-stimulating agents (ESAs) were available. Patients were 64.4±15.9 years old; 55.0% were men. Statistical analysis revealed significant differences between Hb-classes in all of the examined parameters, except erythrocytes mean corpuscular volume and C reactive protein above the threshold, with more critical values in higher Hb-classes. The usage of ESAs showed a mean difference between Hb-class III and Hb-class I of 6.4 units/day and kilogram body weight in a 120-day period.

Conclusion

Our classification system allows an easily achievable overview of the patients’ responsiveness and performance of Hb management. Integrated into a disease management programme or continuous quality improvement, the classification delivers an instant appraisal without complex statistical or mathematical processing.
International variations in primary care physician consultation time: a systematic review of 67 countries
Authors: Irving Greg , Neves Ana Luisa , Dambha-Miller Hajira , Oishi Ai , Tagashira Hiroko , Verho Anistasiya , Holden John
Published: November 2017

Objective

To describe the average primary care physician consultation length in economically developed and low-income/middle-income countries, and to examine the relationship between consultation length and organisational-level economic, and health outcomes.

Design and outcome measures

This is a systematic review of published and grey literature in English, Chinese, Japanese, Spanish, Portuguese and Russian languages from 1946 to 2016, for articles reporting on primary care physician consultation lengths. Data were extracted and analysed for quality, and linear regression models were constructed to examine the relationship between consultation length and health service outcomes.

Results

One hundred and seventy nine studies were identified from 111 publications covering 28 570 712 consultations in 67 countries. Average consultation length differed across the world, ranging from 48 s in Bangladesh to 22.5 min in Sweden. We found that 18 countries representing about 50% of the global population spend 5 min or less with their primary care physicians. We also found significant associations between consultation length and healthcare spending per capita, admissions to hospital with ambulatory sensitive conditions such as diabetes, primary care physician density, physician efficiency and physician satisfaction.

Conclusion

There are international variations in consultation length, and it is concerning that a large proportion of the global population have only a few minutes with their primary care physicians. Such a short consultation length is likely to adversely affect patient healthcare and physician workload and stress.
Impact of prenatal diagnosis on survival of newborns with four congenital heart defects: a prospective, population-based cohort study in France (the EPICARD Study)
Authors: Khoshnood Babak , Lelong Nathalie , Houyel Lucile , Bonnet Damien , Ballon Morgane , Jouannic Jean-Marie , Goffinet François
Published: November 2017

Objectives

(1) Assess the population-level probability of prenatal diagnosis and termination of pregnancy for fetal anomaly for four major congenital heart defects; (2) Examine, using population-based data, the relation between timing of (prenatal vs postnatal) diagnosis and risk of infant (ie, < 1 year) mortality for four major congenital heart defects (CHDs).

Design

Population-based cohort (the EPIdémiologie des CARDiopathies congénitales) study.

Setting

Greater Paris area (Paris and its surrounding suburbs).

Patients

Three hundred and fifty-four cases of four major CHDs, including functionally univentricular heart (FUH, N=132), d-transposition of great arteries (d-TGA, N=85), tetralogy of Fallot (TOF, N=60) and coarctation of aorta (CoA, N=77). Statistical analysis included the Mantel-Haenszel method and a test of homogeneity of risk ratios.

Results

Approximately 95% of FUH, more than two-thirds of d-TGA and TOF, and 40% of CoA were prenatally diagnosed. Overall, we did not find any statistically significant association between timing of (prenatal vs postnatal) diagnosis of CHD and risk of infant mortality (Mantel-Haenszel risk ratio 1.1, 95% CI 0.5 – 2.7); and the differences between the risk ratios of the association between prenatal diagnosis and infant mortality across the four CHDs was not statistically significant.

Conclusion

These results imply that at least in the settings where specialised services are readily available, survival may no longer be the most relevant outcome, or the best criterion, for evaluating the impact of prenatal diagnosis on the outcome of CHD. The beneficial effects of prenatal diagnosis may be better sought by looking at more ’subtle' or long-term neurodevelopmental outcomes.
Diagnostic utility of appetite loss in addition to existing prediction models for community-acquired pneumonia in the elderly: a prospective diagnostic study in acute care hospitals in Japan
Authors: Takada Toshihiko , Yamamoto Yosuke , Terada Kazuhiko , Ohta Mitsuyasu , Mikami Wakako , Yokota Hajime , Hayashi Michio , Miyashita Jun , Azuma Teruhisa , Fukuma Shingo , Fukuhara Shunichi
Published: November 2017

Objective

Diagnosis of community-acquired pneumonia (CAP) in the elderly is often delayed because of atypical presentation and non-specific symptoms, such as appetite loss, falls and disturbance in consciousness. The aim of this study was to investigate the external validity of existing prediction models and the added value of the non-specific symptoms for the diagnosis of CAP in elderly patients.

Design

Prospective cohort study.

Setting

General medicine departments of three teaching hospitals in Japan.

Participants

A total of 109 elderly patients who consulted for upper respiratory symptoms between 1 October 2014 and 30 September 2016.

Main outcome measures

The reference standard for CAP was chest radiograph evaluated by two certified radiologists. The existing models were externally validated for diagnostic performance by calibration plot and discrimination. To evaluate the additional value of the non-specific symptoms to the existing prediction models, we developed an extended logistic regression model. Calibration, discrimination, category-free net reclassification improvement (NRI) and decision curve analysis (DCA) were investigated in the extended model.

Results

Among the existing models, the model by van Vugt demonstrated the best performance, with an area under the curve of 0.75(95% CI 0.63 to 0.88); calibration plot showed good fit despite a significant Hosmer-Lemeshow test (p=0.017). Among the non-specific symptoms, appetite loss had positive likelihood ratio of 3.2 (2.0–5.3), negative likelihood ratio of 0.4 (0.2–0.7) and OR of 7.7 (3.0–19.7). Addition of appetite loss to the model by van Vugt led to improved calibration at p=0.48, NRI of 0.53 (p=0.019) and higher net benefit by DCA.

Conclusions

Information on appetite loss improved the performance of an existing model for the diagnosis of CAP in the elderly.
Diagnostic performance of an acoustic-based system for coronary artery disease risk stratification
Authors: Winther Simon , Nissen Louise , Schmidt Samuel Emil , Westra Jelmer Sybren , Rasmussen Laust Dupont , Knudsen Lars Lyhne , Madsen Lene Helleskov , Kirk Johansen Jane , Larsen Bjarke Skogstad , Struijk Johannes Jan , Frost Lars , Holm Niels Ramsing , Christiansen Evald Høj , Botker Hans Erik , Bøttcher Morten
Published: November 2017

Objective

Diagnosing coronary artery disease (CAD) continues to require substantial healthcare resources. Acoustic analysis of transcutaneous heart sounds of cardiac movement and intracoronary turbulence due to obstructive coronary disease could potentially change this. The aim of this study was thus to test the diagnostic accuracy of a new portable acoustic device for detection of CAD.

Methods

We included 1675 patients consecutively with low to intermediate likelihood of CAD who had been referred for cardiac CT angiography. If significant obstruction was suspected in any coronary segment, patients were referred to invasive angiography and fractional flow reserve (FFR) assessment. Heart sound analysis was performed in all patients. A predefined acoustic CAD-score algorithm was evaluated; subsequently, we developed and validated an updated CAD-score algorithm that included both acoustic features and clinical risk factors. Low risk is indicated by a CAD-score value ≤20.

Results

Haemodynamically significant CAD assessed from FFR was present in 145 (10.0%) patients. In the entire cohort, the predefined CAD-score had a sensitivity of 63% and a specificity of 44%. In total, 50% had an updated CAD-score value ≤20. At this cut-off, sensitivity was 81% (95% CI 73% to 87%), specificity 53% (95% CI 50% to 56%), positive predictive value 16% (95% CI 13% to 18%) and negative predictive value 96% (95% CI 95% to 98%) for diagnosing haemodynamically significant CAD.

Conclusion

Sound-based detection of CAD enables risk stratification superior to clinical risk scores. With a negative predictive value of 96%, this new acoustic rule-out system could potentially supplement clinical assessment to guide decisions on the need for further diagnostic investigation.

Trial registration number

ClinicalTrials.gov identifier NCT02264717; Results.
Abdominal trauma in dogs 1. emergency investigation
Authors: Humm Karen , Cortellini Stefano
Published: November 2017

This is the first article of a two‐part series on abdominal trauma in dogs. This article focuses on the initial stabilisation and investigation of these canine patients, while the second article, to be published in a subsequent issue of In Practice, will discuss management of these patients. Although divided in this fashion, investigation and management are often concurrent in the emergency patient and this will be emphasised when particularly pertinent.
Comments on the dilemma in the October issue: Ethical issues in the slaughterhouse
Authors: McCulloch Steven
Published: November 2017

In the dilemma discussed in the October issue of In Practice, an Official Veterinarian (OV) is newly employed in a small‐ to medium‐sized three‐species abattoir. The OV's attention is drawn to an experienced slaughterman who is shooting inaccurately and practising poor exsanguination technique. He has been under scrutiny already for failing to accurately place bolt shots in cattle. His other work is slipshod, but the business operator fears a counter accusation of prejudice (IP, October 2017, vol 39, pp 430‐431). John Cranley says that the OV must instruct the business operator to replace the slaughterman without delay. The OV has a duty to acquire evidence and must report the case to the competent authority for further investigation. A full stun must be applied so that the animal does not regain consciousness before death.
Surgical safety checklist training: a national study of undergraduate medical and nursing student teaching, understanding and influencing factors
Authors: Kilduff Caroline Laura Stephanie , Leith Thomas Oliver , Drake Thomas M , Fitzgerald J Edward F
Published: November 2017

Introduction

Use of the WHO surgical safety checklist is consistently recognised to reduce harm caused by human error during the perioperative period. Inconsistent engagement is considered to contribute to persistence of surgical Never Events in the National Health Service. Most medical and nursing graduates will join teams responsible for the perioperative care of patients, therefore appropriate undergraduate surgical safety training is needed.

Aims

To investigate UK medical and nursing undergraduate experience of the surgical safety checklist training.

Methods

An eight-item electronic questionnaire was distributed electronically to 32 medical schools and 72 nursing schools. Analysis was conducted for the two cohorts, and responses from final year students were included.

Results

87/224 (38.8%) of medical students received teaching on the surgical safety checklist, compared with 380/711 (52.0%) of nursing students. 172/224 (76.8%) of medical students and 489/711 (66.9%) of nursing students understood its purpose and 8/224 (3.6%) medical students and 54/711 (7.4%) nursing students reported never being included in the Time Out. After adjusting for confounding factors, provision of formal teaching in checklist use increased understanding significantly (OR 50.39 (14.07 to 325.79, P<0.001)), as did routine student involvement in time outs (OR 5.72 (2.36 to 14.58, P<0.001)).

Discussion

Knowledge of perioperative patient safety systems and the ability to participate in safety protocols are important skills that should be formally taught at the undergraduate level. Results of this study show that UK undergraduate surgical safety checklist training does not meet the minimum standards set by the WHO.
Antipsychotic-induced hyperprolactinaemia: case studies and review
Authors: Mittal Shweta , Prasad Suveera , Ghosh Adwaita
Published: November 2017

Antipsychotics are a known cause of hyperprolactinaemia and can be associated with significant health issues in short term and long term. The effects vary with gender and age of the individual and can contribute towards non-concordance and hence relapse in mental health of our patients. Clinicians need to educate the patients about this significant side effect of not only antipsychotic medications but other medications causing hyperprolactinaemia commonly prescribed in primary care.
Young adult smokers’ perceptions of plain packs, numbered packs and pack inserts in Turkey: a focus group study
Authors: Mucan Burcu , Moodie Crawford
Published: November 2017

Introduction

The Turkish Government’s ‘National Tobacco Control Program 2015–2018’ included plans to introduce plain packaging and also a ban on brand names on cigarette packs, allowing only assigned numbers on packs. We explored perceptions of these proposed measures, and also pack inserts with cessation messages, another novel way of using the packaging to communicate with consumers.

Methods

Eight focus groups were conducted with 47 young adult smokers in Manisa and Kutahya (Turkey) in December 2016. Participants were shown three straight-edged plain cigarette packs, as required in Australia, and then three bevelled-edged plain packs, as permitted in the UK. They were then shown plain packs with numbers rather than brand names, and finally three pack inserts with messages encouraging quitting or offering tips on how to do so. Participants were asked about their perceptions of each.

Results

Plain packs were considered unappealing and off-putting, although the bevelled-edged packs were viewed more favourably than the straight-edged packs. Numbered packs were thought by some to diminish the appeal created by the brand name and potentially decrease interest among never smokers and newer smokers. Pack inserts were thought to have less of an impact than the on-pack warnings, but could potentially help discourage initiation and encourage cessation.

Conclusions

That bevelled-edged plain packs were perceived more positively than straight-edged plain packs is relevant to countries planning to introduce plain packaging. The study provides a first insight into smokers’ perceptions of a ban on brand names, which was perceived to reduce appeal among young people.
The Pele Offset Dykes, Sudbury impact structure, Canada
Authors: Pilles Eric A. , Osinski Gordon R. , Grieve Richard A.F. , Coulter Adam B. , Smith David , Bailey Joshua
Published: November 2017

The Offset Dykes are impact melt-bearing dykes related to the 1.85 Ga Sudbury impact structure. Currently, the dykes extend radially outward from—or occur concentrically around—the Sudbury Igneous Complex, which is the remnant of a differentiated impact melt sheet and the source of the dykes. The recently identified three Pele Offset Dykes intrude into the Archean rocks north of the Sudbury Igneous Complex. In this study, the Pele dykes are characterized for the first time by a combination of fieldwork, optical microscopy, electron microprobe analyses, and bulk geochemical analyses. The Pele Offset Dykes stand out from the other Offset Dykes at Sudbury in two significant ways: (i) All other known Offset Dykes consist of an inclusion-rich lithology in the center of the dyke and an inclusion-poor lithology along the margins. The Pele dykes, however, are only composed of the inclusion-poor phase. (ii) The Pele dykes—particularly the Central and Eastern dykes—have a more evolved chemical composition relative to the other Offset Dykes. These observations suggest that the Pele dykes were emplaced after the other known Offset Dykes during two injection events: the Western followed by the Central and Eastern Pele dykes.
Estimating disperser abundance using open population models that incorporate data from continuous detection passive integrated transponder arrays
Authors: Dzul M.C. , Yackulic C.B. , Korman J.
Published: November 2017

Autonomous passive integrated transponder (PIT) tag antenna systems continuously detect individually marked organisms at one or more fixed points over long time periods. Estimating abundance using data from autonomous antennas can be challenging because these systems do not detect unmarked individuals. Here we pair PIT antenna data from a tributary with mark–recapture sampling data in a mainstem river to estimate the number of fish moving from the mainstem to the tributary. We then use our model to estimate abundance of non-native rainbow trout (Oncorhynchus mykiss) that move from the Colorado River to the Little Colorado River, the latter of which is important spawning and rearing habitat for federally endangered humpback chub (Gila cypha). We estimate that 226 rainbow trout (95% confidence interval: 127–370) entered the Little Colorado River from October 2013 to April 2014. We discuss the challenges of incorporating detections from autonomous PIT antenna systems into mark–recapture population models, particularly in regards to using information about spatial location to estimate movement and detection probabilities.