bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of 3D Printed Flexible Strain Sensors
Authors: Mamer Trevor , Garcia Jose , Leon-Salas Walter D. , Voyles Richard , Nawrocki Robert A. , Yokota Tomoyuki , Someya Takao , Ducharne Benjamin , Newell Brittany
Published: November 2020

3D printing technologies have advanced significantly in recent years allowing for additive manufacturing of new structured materials, expanding the range, function, and capabilities of manufactured components. In this work, flexible capacitors were produced using additive manufacturing and compared to commercially available capacitance sensors in strain testing. The sensors utilize thermoplastic polyurethane (TPU) printed using fused filament fabrication methods as a dielectric substrate and a combination of flexible inks for production of the conductive surface. Flexible inks were printed using syringe based deposition methods on a custom designed printer using the TPU substrate. Results demonstrated successful capacitor production with capacitance values ranging from 2–70 pF depending on geometry, material, and printing conditions. The 3D printed flexible capacitors were characterized over a frequency range of 100 Hz to 10 kHz and compared to commercial roll-to-roll produced capacitors. Strain testing was conducted from 0–50% strain using a mechanical testing machine for the range of sensors and final capacitance post strain was measured to calculate deviation from original capacitance values. The sensors exhibited a relatively linear increase in capacitance when strained and returned to a resting position upon release of strain with minimal hysteresis effects, demonstrating their utility as 3D printed sensors.
A Computational Study of Strain Sensing via 3D-Printed CNF-Modified PLA Strain Gauges
Authors: Maynard Cole M. , Hernandez Julio A. , Doak Andrew , Mardikis Benjamin , Viz Monica , Newell Brittany , Garcia Jose , Tallman Tyler N.
Published: November 2020

Additive manufacturing technologies and products have seen significant growth in the last decade but have the potential to see greater advancement with the addition of functional material properties in filaments, vastly expanding the product range. Polylactic acid (PLA) is a common fused deposition modeling (FDM) material used for additive manufacturing. Currently, filament materials are limited in terms of electrical properties with the majority of filaments being dielectric. Imparting electrical properties via nanofiller modification of traditionally insulating PLA is an exciting direction for multi-functional additive manufacturing. The work presented in this manuscript computationally explores the piezoresistive strain sensing performance of multi-functional PLA. Specifically, we use experimental conductivity data collected from carbon nanofiber (CNF)-modified PLA to calibrate a computational piezoresistivity model. This computational model is then used to simulate the resistance change-strain relationship of a representative additively manufactured sensor shape. This study shows that the CNF/PLA sensor exhibits a non-linear response with a strain-dependent gauge factor ranging from 15.0 in compression to up to approximately 33.2 in tension. Computational tools such as the ones presented herein are important for further development of additively manufactured sensors since it allows researchers to explore a wide design space (e.g. shape, material type, etc.) without resorting to trial and error experimentation. This allows the incredible versatility of additive manufacturing to be more thoroughly leveraged.
High Voltage AC Control of SMA Wires
Authors: Gorges Tom , Rizzello Gianluca , Seelecke Stefan , Motzki Paul
Published: November 2020

Alternating voltage is available in many environments for actuators. Due to the fact that a lot of actuators cannot directly handle this type of supply voltage, such as shape memory alloy (SMA) actuators, the voltage is usually converted to direct current. In the case of SMA actuators, the supply voltage often even has to be adjusted to the electrical resistance of each particular actuator. Due to high energy potential in AC supplies, conventional activation for SMA actuators over several seconds is not possible.

In this study a control procedure for SMA wire actuators with high AC voltage supply is presented, which allows very flexible and versatile control of SMA wires. In addition two different types of activation are distinguished in an experimental study: one-time activation and activation over a longer period of time. The objective of the one-time activation is to reach a given actuator displacement. The activation over time is intended to hold a given position. The results of this series of experiments are presented and the resulting energy saving potential in high voltage SMA activation is observed.
Design and Experimental Investigation of a Flexible Trailing Edge for Wind Energy Turbine Blades
Authors: Pohl Martin , Riemenschneider Johannes , Monner Hans Peter
Published: November 2020

The demand of affordable, renewable electric energy is still increasing. Wind energy is seen as one of the most promising resources for future electric energy supply. To reduce the cost of wind energy the dimensions of wind energy turbines are still increasing. This leads to higher power output due to the larger rotor diameters, but also due to the higher wind speeds above the boundary layer. This increase in rotor diameter is achieved at the expense of much higher structural loads especially in the rotor blade root. These loads consist of bending moments, that are mainly caused by gravity, wind shear, gusts and the tower influence to the blade.

A reduction of these root bending moments would allow a further increase of the rotor diameter, a longer lifetime or a lighter design and therefore be advantageous for the turbine. Load reduction can be achieved by using a trailing edge flap at the outer region of the blade, comparable to control surfaces of aircraft. This trailing edge is capable of moving several times per blade revolution and allows the manipulation of the flow to alleviate changes in the aerodynamic loading. In contrast to aircraft, sealing against environmental media, such as rain, dust, insects and so on is much more important to allow a high lifetime and low maintenance effort. Therefore, a flexible and gapless morphing trailing edge has been designed within the SmartBlades projects at the German Aerospace Center (DLR) for the mentioned purpose. Based on this design, a demonstrator was built, which was tested in a wind tunnel and on a rotational test site for its performance.

The paper will present the approach beginning with some design and modeling considerations of the flexible trailing edge and the demonstrator, which was used for testing. Main focus of the paper is the presentation of results obtained from a wind tunnel experiment at Oldenburg University and the rotational experiment at the field research site of the Technical University in Denmark (DTU). In these experiments, the effectiveness of the trailing edge flap could be demonstrated in the wind tunnel as well as in free field. Based on pressure taps and force sensors, the change in the lift of the airfoil due to the deflection of the flexible trailing edge was measured and the resulting polars are shown in this paper. Furthermore, the result of different simple control strategies for the trailing edge in terms of load reduction at the rotating test rig will be presented.
System Simulation of an Elastocaloric Heating and Cooling Device Based on SMA
Authors: Welsch Felix , Kirsch Susanne-Marie , Michaelis Nicolas , Mandolino Michele , Schütze Andreas , Seelecke Stefan , Motzki Paul , Rizzello Gianluca
Published: November 2020

Elastocaloric (EC) cooling uses solid-state NiTi-based shape memory alloy (SMA) as a non-volatile cooling medium and enables a novel environment-friendly cooling technology. Due to the high specific latent heats activated by mechanical loading/unloading, substantial temperature changes are generated in the material. Accompanied by a small required work input, a high coefficient of performance is achievable.

Recently, a fully functional and illustrative continuous operating elastocaloric air cooling system based on SMA was developed and realized. To assist the design process of an optimized device with given performance and efficiency requirements, a fully coupled thermo-mechanical system-level model of the multi-wire cooling unit was developed and implemented in MATLAB. The resulting compact simulation tool is qualified for massively parallel computation, which allows fast and comprehensive parameter studies.

In this work, the influence of different SMA diameters, rotation frequencies, and airflow rates is investigated. The results are analyzed to find the suited parameter for high efficiency (COP) and temperature span.
Terfenol-D Carbon Fiber Reinforced Polymer (CFRP): Embedded Sensing for Early Localized Damage Detection
Authors: Williams Brandon , Hall Asha , Myers Oliver
Published: November 2020

Carbon Fiber Reinforced Polymers (CFRPs) have become an essential part of designing and engineering lightweight rigid bodies, predominantly in the aerospace and automotive industries. Typical epoxy based CFRPs exhibit virtually no plasticity with minimal strain to failure. Although CFRPs have high specific strengths and elastic moduli, the brittle fracture mechanism presents unique challenges in failure detection for the US Army’s vertical lift vehicle components since failure can occur catastrophically. The Army currently uses a “safe-life” interval-based service methodology where components are replaced with regards to a usage spectrum rather than the component’s actual state of structural health. This paper explores a method for solving this problem by investigating the possibility of embedding Terfenol-D particles (∼100 microns in diameter), a magnetostrictive material, into the CFRP’s ply interphase for embedded non-contact, real-time, structural health monitoring. For baseline results, the change in localized (32 mm2 field of view) magnetic flux was only 0.02% for an applied load of 0–100% of the material’s ultimate tensile strength (UTS). For quasi-static testing procedure on specimen 5714 (15 wt.% Terfenol-D embedded CFRP) on a 0–40% loading interval of the material’s UTS, there was an observed localized (32 mm2 field of view) magnetic flux gradient of more than 5 mT (4%) with a reversible flux of 100%. For quasi-static testing procedure on specimen 5714 (15 wt.% Terfenol-D embedded CFRP) on a 0–70% loading interval of the material’s UTS, there was an observed localized (32 mm2 field of view) magnetic flux gradient of more than 3 mT (2%) with a reversible flux of only 25%. Terfenol-D embedded CRFPs have shown promising results for detecting instantaneous strain and degradation levels. Acoustic emission (AE) and X-ray computed tomography (CT) scanning were used to validate the observed results.
Noncontact/Remote Material Characterization Using Ultrasonic Guided Wave Methods
Authors: Ma Zhaoyun , Yu Lingyu
Published: November 2020

Noncontact and remote NDE systems and methods are highly desired in a broad range of engineering applications such as material property characterization. This paper aims to develop such a noncontact/remote NDE system based on laser ultrasonic guided waves and establish its fundamental capability for material thickness evaluation. The noncontact system employs pulsed laser (PL) for guided wave actuation and scanning laser Doppler vibrometer (SLDV) for guided wave wavefield sensing. A cylindrical planoconvex lens is adopted to focus the pulsed laser beam to a line source in order to excite broad band signals in the target plate. Aluminum plates with different thicknesses are evaluated through SLDV line scans and 2D time-space wavefields are acquired. Frequency-wavenumber (f-k) spectra are obtained through 2D Fourier transform, and the A0 dispersion curve for each plate is extracted. Through Comparing the extracted A0 curve with the theoretical A0 dispersion curves, the thicknesses of the tested plates are identified. Reflective tape effect on the plates are also studied: the reflective tape attached for SLDV enhancement affects the guided waves in the target plate significantly when the plate is relatively thin.
Designing a Morphable Parabolic Reflector Antenna Using Origami-Inspired Discretization and Efficient Global Optimization
Authors: Wilson Gregory , Lagoudas Dimitris , Hartl Darren
Published: November 2020

This research explores a segmented parabolic antenna that can change its physical shape via shape memory alloy actuators, thereby altering its radiation pattern when transmitting a signal. The parabolic dish has been discretized into an origami pattern to make use of the naturally compliant fold regions, about which shape memory alloy wires create moments. Modeling of antenna deformation is accomplished via Abaqus considering SMA wires contracting due to temperature change as a manifestation of the shape memory effect. An electromagnetic analysis of the deformed antenna follows in ANSYS-HFSS to determine the antenna gain in all directions around the structure. The computed radiation pattern is projected onto a goal shape (e.g. the contiguous United States) to determine the degree to which the shaped broadcast pattern matches that of a desired broadcast area. Finally, the design is iterated using an efficient global optimization algorithm to ascertain an actuation schedule that generates the most conformal broadcast pattern. Traditional optimization algorithms such as genetic or particle swarm may require thousands of designs, particularly when many design variables are considered. The efficient global optimization algorithm employs far fewer designs by fitting surrogate models to the data and only testing points where large improvement is expected, thus reducing design optimization time. The evolution and improvement to an antenna will be discussed for an antenna making use of eight, 16, and 24 SMA linear actuators to most optimally broadcast to only the United States while avoiding signal spill-over into other regions, and the lessons learned can then applied to match broadcast pattern based on other countries as well.
Numerical Optimization of Liner Impedance in Acoustic Duct
Authors: Billon Kévin , de Bono Emanuele , Perez Matthias , Collet Manuel , Salze Edouard , Matten Gaël , Ouisse Morvan , Volery Maxime , Lissek Hervé , Mardjono Jacky
Published: November 2020

The SALUTE project aims at evaluating performance of metacomposites for acoustic smart lining in grazing turbulent flow. Theoretical and numerical investigations are carried out for designing innovative specimen. A specific focus is placed in the realization of prototypes for evaluating the metacomposite liner performances in 2D and 3D liners, its process complexity and robustness. The insight gain in this project is new tools for obtaining innovative samples; the acoustical experimental tests demonstrate efficiency and robustness of such technology for controlling UHBR noise emission. This paper is focused on parametric study based on the maximization of the absorption coefficient in a duct by optimizing the impedance of a treated area.
Design and Optimization of Piezoelectric Actuators for Aeroacoustic Noises Control in a Turbofan
Authors: Perez M. , Ezzine M. , Billon K. , Clair V. , Mardjono J. , Collet M.
Published: November 2020

This paper reports on the design and optimization of different types of piezoelectric actuators for aeroacoustic control applications. This study was carried out within the context of the European project CleanSky 2/InnoSTAT. The aim of our work is to reduce the aeroacoustic noises that appear in an airplane turbofan by adding an area of piezoelectric actuators on the Outlet Guide Vanes (OGV). These piezoelectric structures will subsequently be controlled with an active approach and tested in the open-jet anechoic wind tunnel at LMFE. The noise source which has to be reduce/control comes from vortices located in the turbulent flow (which can for example be created by the fan module) interacting with the stator blades. The predominant frequencies and the pressure fluctuations levels related to these vortices rely on the airflow speed and are fixed between 1000Hz and 2000Hz in our case. To reach the target, we plan to manufacture an area of piezoelectric actuators on the intrados and the extrados of the stator blades in order to control the response of the blade to the turbulence of the airflow responsible for the aeroacoustic noise. Several adjacent blades will be equipped with this type of transducers. This study outline the design and the optimization of each piezoelectric cell in order to achieve good results in the frequency range previously defined as well as an acceptable mechanical strength of the blade. A most detailed study on the active shunt will be investigate later on.
Structure and behavior of ZrO2-graphene-ZrO2 stacks
Authors: Kahro Tauno , Castán Helena , Dueñas Salvador , Merisalu Joonas , Kozlova Jekaterina , Jõgiaas Taivo , Piirsoo Helle-Mai , Kasikov Aarne , Ritslaid Peeter , Mändar Hugo , Tarre Aivar , Tamm Aile , Kukli Kaupo
Published: November 2020

ZrO2-graphene-ZrO2 layered structures were built and their crystallinity was characterized before resistive switching measurements. Thin nanocrystalline ZrO2 dielectric films were grown by atomic layer deposition on chemical vapor deposited graphene. Graphene was transferred, prior to the growth of the ZrO2 overlayer, to the ZrO2 film pre-grown on titanium nitride. Nucleation and growth of the top ZrO2 layer was improved after growing an amorphous Al2O3 interface layer on graphene at lowered temperatures. Studies on resistive switching in such structures revealed that the exploitation of graphene interlayers could modify the operational voltage ranges and somewhat increase the ratio between high and low resistance states.
Short-Term Effects of Appropriate Empirical Antimicrobial Treatment with Ceftolozane/Tazobactam in a Swine Model of Nosocomial Pneumonia
Authors: Motos Ana , Li Bassi Gianluigi , Pagliara Francesco , Fernandez-Barat Laia , Yang Hua , Aguilera Xiol Eli , Senussi Tarek , Idone Francesco A. , Travierso Chiara , Chiurazzi Chiara , Amaro Rosanel , Yang Minlan , Bobi Joaquim , Rigol Montserrat , Nicolau David P. , Frigola Gerard , Cabrera Roberto , Ramirez Jose , Pelosi Paolo , Blasi Francesco , Antonelli Massimo , Artigas Antonio , Vila Jordi , Kollef Marin , Torres Antoni
Published: November 2020

The rising frequency of multidrug-resistant and extensively drug-resistant (MDR/XDR) pathogens is making more frequent the inappropriate empirical antimicrobial therapy (IEAT) in nosocomial pneumonia, which is associated with increased mortality. We aim to determine the short-term benefits of appropriate empirical antimicrobial treatment (AEAT) with ceftolozane/tazobactam (C/T) compared with IEAT with piperacillin/tazobactam (TZP) in MDR
Pseudomonas aeruginosa
pneumonia. Twenty-one pigs with pneumonia caused by an XDR
P. aeruginosa
strain (susceptible to C/T but resistant to TZP) were ventilated for up to 72 h.
Complete Genome Sequence of Rahel, a C1 Cluster Mycobacteriophage
Authors: Nieto-Fernandez Fernando E. , Noutsos Christos , Nissen Jillian , Abdelsalam Yara , Ackloo Jessica , Banger Navpreet , Chan Hason , Chittineedi Tarana , Duplessy Isabel , Dyce Mark , Garrison Daesha , Gonzalez Jaime , John Sandra , Kahlon Imanjot , Kumar Tania , Lewis Adwoa , Madhira Karthik , Mullokandova Rivka , Pirzadeh Nellie , Raja Iman , Ram Kevin , Ramdhari Ravi , Reddy Rita , Saed Briana S. , Smith Phalan , Sproul Steeve , Thomas Jane , Yossefi Avia , Morales Jorge
Published: November 2020

Rahel is a lytic
Myoviridae
bacteriophage that infects
Mycobacterium smegmatis
mc
2
155. It has 1,555,955 bp and 64.7% G+C content. Rahel has a circularly permuted genome with 270 genes, 53 of them of known function, 33 tRNAs, and 1 transfer-messenger RNA (tmRNA). Only five genes are coded on the reverse strand.
Whole-Genome Assemblies for Three Yersinia pestis Strains Isolated in Erenhot, China
Authors: Wang Jing , Yang Xifeng , Zheng Hongyuan , Tian Li , Shi Qi , Wu Jing , Cui Yujun , Song Yajun , Guo Wenxiu , Yun Tuoya , Yun Hua , Jin Muzi , Chen Yufei , Zhang Sheng , Wei Huaibo
Published: November 2020

To explore the genetic diversity of
Yersinia pestis
in Erenhot, China, and their relationship with Mongolia strains, we collected and sequenced three
Y. pestis
strains from Erenhot, China, in 2018. Here, we report the draft genome sequences of three
Y. pestis
bv. Medievalis strains belonging to the 2.MED phylogroup that were circulating in
Meriones unguiculatus
populations.
Hooked on salt: Rethinking Alpine tectonics in Hallstatt (Eastern Alps, Austria)
Authors: Fernández Oscar , Habermüller Mario , Grasemann Bernhard
Published: November 2020

Permian salt in the Hallstatt and neighboring salt structures of the Eastern Alps (Austria) crops out along with Triassic deep-water deposits that are at odds with the surrounding Triassic platform carbonates. The traditional interpretation of this juxtaposition is that the salt bodies were emplaced in the Late Jurassic as gravity nappes onto the carbonate platforms, in what has been considered to be the earliest orogenic event in the Eastern Alps. Here we describe for the first time a world-class outcrop of halokinetic sequences in Triassic platform carbonates flanking the Hallstatt diapir. Combining this with other outcrop evidence, we prove that the Hallstatt diapir grew passively during the Triassic, surrounded by carbonate platforms, and extruded to the seabed during the Jurassic. The development of the Hallstatt diapir in a platform setting disproves its emplacement as a gravity-driven nappe, proves the relevance of salt tectonics in the Mesozoic development of the Eastern Alps, and challenges the existence of a Late Jurassic Alpine orogenic event.
Seismicity trends and detachment fault structure at 13°N, Mid-Atlantic Ridge
Authors: Parnell-Turner R. , Sohn R.A. , Peirce C. , Reston T.J. , MacLeod C.J. , Searle R.C. , Simão N.M.
Published: November 2020

At slow-spreading ridges, plate separation is commonly partly accommodated by slip on long-lived detachment faults, exposing upper mantle and lower crustal rocks on the seafloor. However, the mechanics of this process, the subsurface structure, and the interaction of these faults remain largely unknown. We report the results of a network of 56 ocean-bottom seismographs (OBSs), deployed in 2016 at the Mid-Atlantic Ridge near 13°N, that provided dense spatial coverage of two adjacent detachment faults and the intervening ridge axis. Although both detachments exhibited high levels of seismicity, they are separated by an ∼8-km-wide aseismic zone, indicating that they are mechanically decoupled. A linear band of seismic activity, possibly indicating magmatism, crosscuts the 13°30′N domed detachment surface, confirming previous evidence for fault abandonment. Farther south, where the 2016 OBS network spatially overlapped with a similar survey done in 2014, significant changes in the patterns of seismicity between these surveys are observed. These changes suggest that oceanic detachments undergo previously unobserved cycles of stress accumulation and release as plate spreading is accommodated.
Median arcuate ligament syndrome in a patient with frontal lobe syndrome
Authors: Pandian Sri Lakshmi Kanthan , Sanniyasi Saravana , Ravindra Sanjana , Cunnigaiper Narayanan D
Published: November 2020

A boy aged 19 years presented to emergency room with severe postprandial upper abdominal pain and recent significant weight loss, with history of decompressive craniotomy for post-traumatic frontal lobe haemorrhage. CT scan revealed an acute indentation of coeliac artery with high-grade stenosis and post-stenotic dilatation, diagnostic of median arcuate ligament syndrome (MALS). MALS, a diagnosis of exclusion, is identified using patient’s accurate symptomatic description. Exclusion of other causes of abdominal angina in a patient with frontal lobe syndrome was a challenging job, as they lack critical decision-making ability. Hence, the decision to proceed with the complex laparoscopic procedure was made by the patient’s parents and the surgeon, with the patient’s consent. Laparoscopic release of the median arcuate ligament resulted in relief of the patient symptoms much to the relief of his parents and the surgeon.
Pneumopericardium and pleural effusion: a rare complication of paediatric pericardiocentesis
Authors: Palma Andreia , Henriques Claudio , Silva Patrícia Vaz , Pires António
Published: November 2020

Pneumopericardium is a rare complication of pericardiocentesis (PC), occurring as a result of either a direct pleuropericardial communication or a leaky drainage system. Pneumopericardium is often self-limiting; however, physicians should be aware of this complication as it may progress to tension pneumopericardium, which requires immediate recognition and management. PC has been associated with pneumothorax, pneumomediastinum or subcutaneous emphysema, but the association with pleural effusion has been less reported. The authors present the case of a 14-year-old healthy boy who developed post-PC pneumopericardium and pleural effusion, a rare association reported in the literature. The diagnosis of this potential life-threatening event was made using readily available complementary diagnostic methods, such as transthoracic echocardiography and chest X-ray.
Haemorrhagic nasal polyp mimicking melanoma in an 83-year-old on rivaroxaban
Authors: Liu Alison , Fang Sean , Kapoor Karan , Babar-Craig Humera
Published: November 2020

An 83-year-old woman presented with rapid onset unilateral nasal obstruction after sneezing. She had a history of hypertension and atrial fibrillation, and was on rivaroxaban. Examination revealed a dark red polypoidal lesion completely obstructing the left nostril. She underwent CT and MRI, and proceeded to urgent excision biopsy of the lesion. Intraoperative appearance was in keeping with a haemorrhagic polyp arising from the nasal septum. Histology revealed haematoma within a layer of nasal mucosa. There was no evidence of haemangioma underlying the polyp. Our literature search has identified this case as the first described haemorrhagic polyp of the nasal septum. It is likely that rivaroxaban contributed to the formation of this haemorrhagic polyp, and it is important to differentiate benign haemorrhagic lesions from malignant conditions such as melanoma. Similar cases may become more common in the future as the proportion of the population on anticoagulants increases.
Haemoperitoneum after an endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of a pancreatic lesion in a peritoneal dialysis patient
Authors: Lew Susie Q , Khan Ali A , Rieders Brandon , Agrawal Satyanisth T
Published: November 2020

Haemoperitoneum was observed in a peritoneal dialysis (PD) patient after undergoing endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). EUS-FNA was performed to evaluate a pancreatic cyst seen on a prekidney transplant evaluation abdominal CT scan. Haemoperitoneum cleared with a PD exchange. In this case report, we discuss aetiologies for bleeding risks in patients with chronic kidney disease and focus on haemoperitoneum in patients receiving PD. We will also explore treatment options to minimise bleeding associated with an abdominal procedure such as EUS-FNA.
Large breast lump with bloody nipple discharge: benign intraductal papilloma
Authors: Cheah Sin Dee , Imi Sairi Abdul Hadi
Published: November 2020

A 32-year-old woman presented with a 3 cm×3 cm left breast lump associated with bloody nipple discharge during her early pregnancy. Examination and ultrasonography showed benign features, whereas core needle biopsies revealed a benign papilloma. Six months after her delivery, a 6 cm×6 cm benign papilloma was completely excised via circumareolar incision. The majority of intraductal papillomas are small; however, they can also present as a large mass rarely. We should be wary of a malignant papillary lesion when there is the presence of atypia on core needle biopsy or imaging-histology discordance. A concordant benign papilloma with benign imaging findings is otherwise reassuring. Clinicians need to be aware of this uncommon presentation of large intraductal papilloma as a complete curative excision can be achieved through a cosmetically placed incision.
Association between P wave polarity in atrial premature complexes and cardiovascular events in a community-dwelling population
Authors: Kabutoya Tomoyuki , Imai Yasushi , Ishikawa Shizukiyo , Kario Kazuomi
Published: November 2020

Objective

To examine the association between polarity of atrial premature complexes (APCs) and stroke.

Design

A prospective study.

Setting and participants

A total of 11 092 participants in the Jichi Medical School cohort study were included after excluding patients with atrial fibrillation. We analysed stroke events in patients with (n=136) and without (n=10 956) APCs. With regard to polarity of APCs, patients were subcategorised into having (1) negative (n=39) or non-negative (n=97) P waves in augmented vector right (aVR), and (2) positive (n=28) or non-positive (n=108) P waves in augmented vector left (aVL).

Outcome measures

The primary endpoint was stroke.

Results

Patients with APCs were significantly older than those without APCs (64.1±9.2 vs 55.1±11.6 years, p<0.001). The mean follow-up period was 11.8±2.4 years. Stroke events were observed in patients with (n=13 events) and without (n=411 events) APCs. This difference was significant (log-rank 12.9, p<0.001); however, APCs were not an independent predictor of stroke after adjusting for age, sex, height, body mass index, current drinking, diabetes, systolic blood pressure, prior myocardial infarction, prior stroke and high-density lipoprotein-cholesterol (p=0.15). The incidence of stroke in patients with APCs and non-negative P wave in aVR was significantly higher than in patients without APCs (log-rank 20.1, p<0.001), and non-negative P wave in aVR was revealed to be an independent predictor of stroke (HR 1.84, 95% CI 1.02 to 3.30). The incidence of stroke in patients with APC with non-positive P wave in aVL was also significantly higher than in patients without APC (log-rank 15.3, p<0.001), and non-positive P wave in aVL was an independent predictor of stroke (HR 1.92, 95% CI 1.05 to 3.54).

Conclusions

The presence of APCs with non-negative P wave in aVR or non-positive P wave in aVL on 12-lead ECG was associated with a higher risk of incident stroke.
Falls in people living with HIV: a scoping review
Authors: Charumbira Maria Yvonne , Berner Karina , Louw Quinette Abegail
Published: November 2020

Objectives

Recent research has indicated seemingly increased propensity for falls and accelerated bone demineralisation in people living with HIV (PLWH). We aim to map out the extent and nature of existing research relating to falls in PLWH and describe the relationship between bone demineralisation and falls in PLWH.

Methods

A scoping review was done following Arksey & O’Malley’s methodological framework and recommendations from Joanna Briggs Institute. Four databases were searched until October 2019 for peer-reviewed studies available in English reporting on the definition, prevalence, assessment, risk factors and interventions for falls in PLWH as well as information on bone demineralisation linked to falls in PLWH. Narrative reviews were excluded. Two reviewers independently performed the extraction using a predesigned Excel sheet. A descriptive analysis of extracted information was done.

Results

Fourteen studies on falls in older PLWH were identified, with all but one study conducted in high-income countries. Prevalence of falls in PLWH ranged from 12% to 41%. Variable assessment tools/tests were used to assess potential risk factors, but it remains to be determined which are more predictive and appropriate for use among PLWH. Considerable agreement existed for risk factors regarding use of medications while evidence regarding functional and cognitive impairments were variable. Few studies compared risk factors for falls in PLWH with those in age-matched and sex-matched seronegative population. There is currently no evidence for interventions to prevent or reduce falls risk in PLWH.

Conclusion

More research is needed on falls in younger cohorts of PLWH and in sub-Saharan Africa where HIV is most prevalent and more robust clades exist. More studies need to report on data in seronegative controls to determine risk factors unique to PLWH. More intervention studies targeted at falls prevention and promotion of bone health are required. Quality clinical practice guidelines highlighting validated assessment tools and outcome measures need to be developed.
Rationale and study protocol of the Physical Activity and Dietary intervention in women with OVArian cancer (PADOVA) study: a randomised controlled trial to evaluate effectiveness of a tailored exercise and dietary intervention on body composition, physical function and fatigue in women with ovarian cancer undergoing chemotherapy
Authors: Stelten Stephanie , Hoedjes Meeke , Kenter Gemma G , Kampman Ellen , Huijsmans Rosalie J , van Lonkhuijzen Luc RCW , Buffart LM
Published: November 2020

Introduction

As a consequence of ovarian cancer and its treatment, many women with ovarian cancer have to deal with reduced physical function, fatigue, and loss of weight and/or muscle mass, compromising quality of life. Exercise and dietary interventions can positively influence body composition, physical fitness and function, and fatigue in patients with cancer. However, there are no data from randomised controlled trials on the effectiveness of exercise and dietary interventions in patients with ovarian cancer. Due to a complex disease trajectory, a relatively poor survival and distinct disease-induced and treatment-induced side effects, it is unclear whether exercise and dietary interventions that were shown to be feasible and effective in other types of cancer produce comparable results in patients with ovarian cancer. The aim of this article is to present the design of the multicentre randomised controlled Physical Activity and Dietary intervention in OVArian cancer trial and to describe how the exercise and dietary intervention is tailored to specific comorbidities and disease-induced and treatment-induced adverse effects in patients with ovarian cancer.

Methods and analysis

Adult women with primary epithelial ovarian cancer who are scheduled to undergo first-line (neo)adjuvant chemotherapy (n=122) are randomly allocated to a combined exercise and dietary intervention or a usual care control group during chemotherapy. Primary outcomes are body composition, physical function and fatigue. Outcome measures will be assessed before the start of chemotherapy, 3 weeks after completion of chemotherapy and 12 weeks later. The exercise and dietary intervention was tailored to ovarian cancer-specific comorbidities and adverse effects of ovarian cancer and its treatment following the i3-S strategy.

Ethics and dissemination

This study has been approved by the medical ethical committee of the Amsterdam UMC (reference: 018). Results of the study will be published in international peer-reviewed journals.

Trial registration number

Netherlands Trial Registry (NTR6300).
Parental experiences of a diagnosis of neonatal diabetes and perceptions of newborn screening for glucose: a qualitative study
Authors: Shepherd Maggie , Knight Bridget A , Laskey Katherine , McDonald Timothy James
Published: November 2020

Neonatal diabetes presents <6 months of life but delays in recognition result in presentation with life-threatening hyperglycaemia/diabetic ketoacidosis. Early identification and rapid genetic diagnosis is crucial and ensures correct treatment/management. Adding ‘glucose’ to newborn bloodspot screening (NBS) could aid prompt detection but requires evidence of parental acceptance.

Objectives

Increase understanding of parental experience of presentation/recognition of neonatal diabetes and perceptions of glucose testing within NBS.

Setting

UK families confirmed with a genetic diagnosis of neonatal diabetes, November 2014–2018, were invited to participate.

Participants

In-depth qualitative interviews were conducted with 10 parents of 14 children. 8 had transient neonatal diabetes: KCNJ11 (n=5), ABCC8 (n=1), 6q24 (n=2), 6 had permanent neonatal diabetes: KCNJ11 (n=4), INS (n=1), homozygous GCK (n=1).

Primary and secondary outcome measures

Interviews audio recorded, transcribed and subjected to thematic content analysis.

Results

3 key themes emerged:

Babies were extremely ill at hospital admission, with extended stays in intensive care required.

Identification of diabetes was not ‘standardised’ and perceived a ‘chance’ finding.

Adding glucose to NBS was universally considered extremely positive.

Conclusions

Diagnosis of neonatal diabetes is frequently delayed, resulting in critically ill presentation with prolonged intensive care support, additional healthcare costs and familial distress. Potential to detect hyperglycaemia earlier was universally endorsed by parents with no negative consequences identified. Although further study including a larger number of individuals is needed to confirm our findings this study provides the first evidence of acceptability of glucose testing fulfilling Wilson-Jungner criteria for implementation within the NBS programme.
Evaluation of the incidence of bleeding in patients prescribed rivaroxaban for the treatment and prevention of deep vein thrombosis and pulmonary embolism in UK secondary care: an observational cohort study
Authors: Evans Alison , Davies Miranda , Osborne Vicki , Roy Debabrata , Shakir Saad
Published: November 2020

Objectives

To evaluate the short-term (12 weeks) safety and utilisation of rivaroxaban prescribed to new-user adult patients for the treatment of deep vein thrombosis and pulmonary embolism and for the prevention of recurrent deep vein thrombosis and pulmonary embolism in a secondary care setting in England and Wales.

Design

An observational cohort study using the technique of Specialist Cohort Event Monitoring.

Setting

The Rivaroxaban Observational Safety Evaluation study was conducted across 87 participating National Health Service secondary care trusts in England and Wales.

Participants

1532 patients treated with rivaroxaban for the prevention and treatment of deep vein thrombosis/pulmonary embolism from September 2013 to January 2016.

Interventions

Non-interventional postauthorisation safety study of rivaroxaban.

Primary and secondary outcome measures

(1) Risk of major bleeding in gastrointestinal, intracranial, and urogenital sites and (2) risk of all major and clinically relevant non-major bleeds.

Results

Of a total of 4846 patients enrolled in the study from September 2013 to January 2016, 1532 were treated with rivaroxaban for the prevention and treatment of deep vein thrombosis/pulmonary embolism. The median age of the deep vein thrombosis/pulmonary embolism cohort was 63 years, and 54.6% were men. The risk of major bleeding within the gastrointestinal, urogenital and intracranial primary sites was 0.7% (n=11), 0.3% (n=5) and 0.1% (n=1), respectively. The risk of major bleeding in all sites was 1.5% (n=23) at a rate of 8.3 events per 100 patient-years.

Conclusions

In terms of the primary outcome risk of major bleeding in gastrointestinal, intracranial and urogenital sites, the risk estimates in the population using rivaroxaban for deep vein thrombosis/pulmonary embolism were low (<1%) and consistent with the risk estimated from clinical trial data and in routine clinical practice.

Trial registration numbers

ClinicalTrials.gov Registry (NCT01871194); ENCePP Registry (EUPAS3979).
Puff or pass: do social media and social interactions influence smoking behaviour of university students? A cross-sectional mixed methods study from Dhaka, Bangladesh
Authors: Roby Naym Uddin , Hasan M Tasdik , Hossain Sahadat , Christopher Enryka , Ahmed Md Kapil , Chowdhury Ariful Bari , Hasan Shahriar , Ashraf Fatema
Published: November 2020

Objective

To determine whether the odds of being a smoker differ based on social media use and social interactions among urban university students in Bangladesh.

Hypothesis

Social media use and social interactions influence the smoking behaviour of Bangladeshi university students, particularly in starting and maintaining cigarette smoking.

Design and setting

A cross-sectional study using mixed methods on 600 student smokers and non-smokers recruited from two public and two private universities in Dhaka, Bangladesh, a lower middle-income country with limited resources. Exclusion criteria were those who did not use any form of social media and PhD students.

Results

Odds of smoking were significantly higher for those who socialised more than 4 hours/day (p<0.05; OR 1.75; 95% CI 1.12 to 2.75) and typically at night (p<0.05; OR 2.80; 95% CI 1.95 to 4.00). Odds of smoking were also higher for those who liked (p<0.05; OR 4.85; 95% CI 3.32 to 7.11), shared (p<0.05; OR 20.50; 95% CI 13.02 to 32.26) and followed (p<0.05; OR 2.88; 95% CI 1.36 to 6.11) tobacco-related content on social media. Qualitative analysis resulted in emergent themes of smokers imitating tobacco-related photos or videos seen on social media and peers as an influence for smoking initiation.

Conclusion

This study suggests social media and social interactions may influence smoking behaviour in university students in Dhaka, Bangladesh. Future research should continue to investigate the roles social media and social interaction have on smoking in order to explore social media-based smoking cessation interventions or dissemination of smoking health hazards through social media.
‘10% of your medical students will cause 90% of your problems’: a prospective correlational study
Authors: Sawdon Marina , McLachlan JC
Published: November 2020

Objectives

Our aim was to explore the relationship between medical student Conscientiousness Index scores and indicators of later clinical performance held in the UK Medical Education Database (UKMED). Objectives were to determine whether conscientiousness in first-year and second-year medical students predicts later performance in medical school and in early practice. Policy implications would permit targeted remediation where necessary or aid in selection.

Design

A prospective correlational study.

Setting

A single UK medical school and early years of practice, 2005–2018.

Participants

The data were obtained from the UKMED on 858 students. Full outcome data was available for variable numbers of participants, as described in the text.

Main outcome measures

Scores on the UK Foundation Programme Office’s Situational Judgement Test (SJT) and Educational Performance Measure (EPM), the Prescribing Safety Assessment (PSA) and Annual Review of Competency Progression (ARCP) outcomes.

Results

Linear regression analysis shows Conscientiousness Index scores significantly correlate with pregraduate and postgraduate performance variables: SJT scores (R=0.373, R2=0.139, B=0.066, p<0.001, n=539); PSA scores (R=0.249, R2=0.062, B=0.343, p<0.001, n=462); EPM decile scores for the first (lowest) decile are significantly lower than the remaining 90% (p=0.003, n=539), as are PSA scores (p<0.001, n=463), and ARCP year 2 scores (p=0.019, n=517). The OR that students in the first decile fail to achieve the optimum ARCP outcome is 1.6126 (CI: 1.1400 to 2.2809, p=0.0069, n=618).

Conclusions

Conscientiousness Index scores in years 1 and 2 of medical school have predictive value for later performance in knowledge, skills and clinical practice. This trait could be used either for selection or for targeted remediation to avoid potential problems in the future.
Effects of exergames training on postural balance in patients who had a chronic stroke: study protocol for a randomised controlled trial
Authors: Bessa Nathalia Priscilla Oliveira Silva , Lima Filho Bartolomeu Fagundes de , Medeiros Candice Simões Pimenta de , Ribeiro Tatiana Souza , Campos Tânia Fernandes , Cavalcanti Fabrícia Azevêdo da Costa
Published: November 2020

Introduction

Exergames training, as an additional therapy to standard care, has been widely used for motor recovery after patients who had a stroke, and it is a valuable and positive tool in the rehabilitation of this population. This study describes a single-blind randomised clinical trial that will aim to investigate the effects of exergames training on postural balance in patients with chronic stroke.

Methods and analysis

Forty-two individuals with chronic stroke (>6 months), aged 20–75 years, will be randomised into two groups: the experimental group, which will be subjected to an exergames protocol, and control group, which will undergo a kinesiotherapy protocol. Both protocols are based on postural balance. The intervention will consist of 40-minute sessions two times per week for 10 consecutive weeks. The volunteers will be evaluated before the treatment, at the end of the interventions and 8 weeks thereafter. The primary outcome will be postural balance (Berg Balance Scale, Functional Reach Test, Timed Up and Go test and Centre of Pressure variables) and secondary outcomes will include gait (6 m timed walk and Kinovea Software), cortical activation patterns (electroencephalography Emotiv EPOC), functional independence (Functional Independence Measure), quality of life (Stroke-Specific Quality of Life Scale) and motivation (Intrinsic Motivation Inventory).

Ethics and dissemination

This protocol was approved by the Ethics Committee of the Federal University of Rio Grande do Norte (number 3.434.350). The results of the study will be disseminated to participants through social networks and will be submitted to a peer-reviewed journal and scientific meetings.

Trial registration number

Brazilian Registry of Clinical Trials (RBR-78v9hx).
End-stage renal disease as a risk factor for epiglottitis: a population-based cohort study in Taiwan
Authors: Tsai Yao-Te , Tsai Ming-Shao , Hsu Cheng-Ming , Fang Ku-Hao , Huang Ethan I , Liu Chia-Yen , Lin Meng-Hung , Yang Yao-Hsu , Lee Yi-Chan , Chang Geng-He
Published: November 2020

Objectives

Patients with uremia are prone to infection; however, end-stage renal disease (ESRD) as a risk factor for acute epiglottitis warrants study. We investigated the risk of severe epiglottitis requiring hospitalisation in patients with ESRD.

Setting

We conducted a retrospective matched cohort study by using the claims data of Taiwan’s National Health Insurance Research Database.

Participants

We identified an ESRD cohort with 87 908 patients newly diagnosed in 2000–2013 and underwent dialysis. The non-ESRD cohort comprised patients who had not received a diagnosis of ESRD, and they were matches to the ESRD cohort (1:1) by sex, age, residence urbanisation level, monthly income, and diabetes and hypertension status.

Primary and secondary outcome measures

The cumulative incidence of epiglottitis at the end of 2013 was analysed with Kaplan-Meier methods and log-rank tests. The HR of epiglottitis was calculated using the Cox proportional hazards model after adjustment for confounding factors.

Results

The overall epiglottitis incidence rate was 94% greater in the ESRD cohort than in the non-ESRD cohort (10.3 vs 5.3 cases per 100 000 person-years, p=0.002), with an adjusted HR of 1.89 (95% CI: 1.23 to 2.91, p=0.004). In the log-rank analysis, compared with the non-ESRD group, the epiglottitis cumulative incidence was significantly higher in the ESRD group (p=0.003). Epiglottitis did not exhibit an association with higher rates of airway interventions, intensive care unit admissions or longer hospitalisation in patients with ESRD than in controls.

Conclusions

This nationwide matched cohort study indicated that ESRD patients should be monitored for the risk of severe epiglottitis requiring hospitalisation.