bluuebunny/crossref_metadata_2025 huggingface dataset:
Borehole Propagation With Undergaged Stabilizers: Theory and Validation
Authors: Zalluhoglu Umut , Marck Julien , Gharib Hossam , Zhao Yiming
Published: December 2018

This paper discusses borehole propagation modeling in the drilling industry. A three-dimensional (3D) borehole propagation model is proposed that tracks the wellbore/stabilizer contacts caused by an overgaged borehole. The resulting model represents a nonlinear delayed system that can be efficiently used to simulate borehole propagation. Simulations are provided to show the model capabilities to capture various drilling scenarios. The predictions are also validated with actual field-test data from mud-motor and rotary-steerable operations. The proposed model can be used to (a) design mud motors and rotary steerable systems (RSSs) and evaluate their steering performance, (b) design and test surface and downhole controllers for wellplan tracking, and (c) provide predictive recommendations to help directional driller operators make steering decisions while drilling.
Multiple-Model Adaptive Control of a Hybrid Solid Oxide Fuel Cell Gas Turbine Power Plant Simulator
Authors: Tsai Alex , Pezzini Paolo , Tucker David , Bryden Kenneth M.
Published: December 2018

A multiple model adaptive control (MMAC) methodology is used to control the critical parameters of a solid oxide fuel cell gas turbine (SOFC-GT) cyberphysical simulator, capable of characterizing 300 kW hybrid plants. The SOFC system is composed of a hardware balance of plant (BoP) component, and a high fidelity FC model implemented in software. This study utilizes empirically derived transfer functions (TFs) of the BoP facility to derive the MMAC gains for the BoP system, based on an estimation algorithm which identifies current operating points. The MMAC technique is useful for systems having a wide operating envelope with nonlinear dynamics. The practical implementation of the adaptive methodology is presented through simulation in the matlab/simulink environment.
The Use of Genetic Algorithms to Calibrate Johnson–Cook Strength and Failure Parameters of AISI/SAE 1018 Steel
Authors: Buchely M. F. , Wang X. , Van Aken D. C. , O'Malley R. J. , Lekakh S. , Chandrashekhara K.
Published: December 2018

Johnson–Cook (JC) strength and failure models have been widely used in finite element analysis (FEA) to solve a variety of thermo-mechanical problems. There are many techniques to determine the required JC parameters; however, a best practice to obtain the most reliable JC parameters has not yet been proposed. In this paper, a genetic-algorithm-based optimization strategy is proposed to calibrate the JC strength and failure model parameters of AISI/SAE 1018 steel. Experimental data were obtained from tensile tests performed for different specimen geometries at varying strain rates and temperatures. FEA was performed for each tensile test. A genetic algorithm was used to determine the optimum JC parameters that best fit the experimental force-displacement data. Calibrated JC parameters were implemented in FEA to simulate the impact tests of standard V-notch Charpy bars to verify the damage mechanism in the material. Considering good agreement of the experimental and FEA results, the current strategy is suggested for calibration proposes in other kind of materials in which plastic behavior could be represented by the JC strength and failure models.
Lifting Wind Turbine Components From a Floating Vessel: A Review on Current Solutions and Open Problems
Authors: Haselsteiner Andreas F. , Ohlendorf Jan-Hendrik , Oelker Stephan , Ströer Lena , Thoben Klaus-Dieter , Wiedemann Katharina , De Ridder Emmanuel , Lehmann Sven
Published: December 2018

Offshore wind energy is experiencing rapid development and is expected to make up an even bigger part of the world's future energy mix. New installation concepts for offshore wind farms involve lifting operations of wind turbine components from floating vessels. These installation concepts will only be economic if the lifting operations are performed safely at sea states with high significant wave heights. In this paper, we give an overview of current technical solutions, which could be used to lift the components tower, nacelle, hub, and rotor blade from a floating vessel. We classify and analyze solutions found in patents and the academic literature and point out open problems, which need to be addressed to enable lifting operations at higher sea states than what is currently feasible. However, we restrict the paper to technical solutions concerning the interface between the vessel and the component as well as the interface between the component and the crane. Consequently, we analyze, classify, and discuss solutions for the seafastening, the lifting gear as well as motion compensation systems. We find that there exists a large number of solutions, which are specific for a single component, but few solutions, which are applicable to all components without major adaptations. Additionally, we miss hydraulic seafastening mechanisms, which are remotely controlled and synchronized with the lifting operation. Consequently, we argue that versatile interfaces between the component and the crane as well as remotely controlled and synchronized seafastening mechanisms are best suited to enhance the lifting process.
A Probabilistic High-Pressure Zone Model for Local and Global Loads During Ice-Structure Interactions
Authors: Taylor Rocky S. , Richard Martin , Hossain Ridwan
Published: December 2018

For temperate ice regions, guidance provided by current design codes regarding ice load estimation for thin ice is unclear, particularly for local pressure estimation. This is in part due to the broader issue of having different recommended approaches for estimating local, global, and dynamic ice loads during level ice interactions with a given structure based on region, scenario type, and a variety of other conditions. It is essential from a design perspective that these three scenarios each be evaluated using appropriate definitions for local design areas, global interaction area, and other structural details. However, the need for use of different modeling approaches for ice loads associated with each of these scenarios is not based on ice mechanics but rather has largely evolved as a result of complexities in developing physics-based models of ice failure in combination with the need to achieve safe designs in the face of limited full-scale data and the need for implementation in a probabilistic framework that can be used for risk-based design assessments. During a given interaction, the ice is the same regardless of the design task at hand. In this paper, a new approach is proposed based on a probabilistic framework for modeling loads from individual high-pressure zones acting on local and global areas. The analysis presented herein considers the case of thin, first-year sea ice interacting with a bottom-founded structure based on an empirical high-pressure zone model derived from field measurements. Initial results indicate that this approach is promising for modeling local and global pressures.
Toward a Method Evaluating Control Actions in STPA-Based Model of Ship-Ship Collision Avoidance Process
Authors: Gil Mateusz , Wróbel Krzysztof , Montewka Jakub
Published: December 2018

As system-theoretic methods of safety assessment are developed, certain aspects of them remain under-explored, including the question of prioritizing one control action's adequacy over another. This paper investigates this feature based on the analysis of a process of merchant vessels' collision avoidance. We first elicit experts' views on the structure of the process and importance of particular interactions occurring therein. Thence, we analyze a number of incident reports to examine the percentage of cases in which failure to ensure the particular control action contributed to the loss. By comparing the results, we strive to determine whether any of the approaches might be beneficial in determining safety control actions' priorities.
Effect of Prehot Corrosion on Erosion Behavior of High Chromium Ferritic Steel for Heat Exchangers
Authors: Mishra Ankitendran , Pradhan Dhananjay , Behera C. K. , Mohan S. , Mohan A.
Published: December 2018

This study presents the prehot corrosion effect on erosion behavior of AISI 446 SS in simulated heat exchanger environment at elevated temperature. Samples were spray deposited using two salt mixture (Na2SO4/NaCl). Subsequently, low-temperature hot corrosion tests were carried out at 550, 650, and 750 °C for 20 h. Chlorination followed by sulfidation was mainly responsible for the passive layer formation during the process of hot corrosion. The prehot corroded samples were subjected to air-jet erosion test using alumina as the erodent, at impact velocity of 100 m/s and flux rate of 4.2 g/min, with variable impingement angles of 30 deg, 60 deg, and 90 deg. The passive layer formed during corrosion underwent detachment of metallic flakes through cracking during the impact of erodent, and was responsible for a significant change in erosion rate. Cutting, plowing, lip formation, and particle embedment were identified as the operative mechanisms during erosion.
Linear and Nonlinear Stability Analysis of a Fixed Caliper Brake During Forward and Backward Driving
Authors: Stump Oliver , Nunes Ronaldo , Häsler Karl , Seemann Wolfgang
Published: December 2018

The parking maneuver of a passenger car is known by bench and vehicle testers to sometimes produce brake squeal, even though the brake system is otherwise quiet. This phenomenon is examined in this work. Pressure foil measurements at the pad caliper contact and acceleration measurements are done on a real break system in order to better understand the mechanisms of the forward–backward driving maneuver. The contact area at the caliper is under a large change during a forward and backward driving maneuver. The measurements motivate linear and nonlinear simulations. A proposal has been made to include the linear effects of parking into the standard robustness analysis with the complex eigenvalues calculation. A time integration of the full nonlinear system shows a possible stable limit cycle, when the brake pad moves from the leading to the trailing side, like in a parking maneuver. This growth of amplitude is not anticipated from the complex eigenvalue analysis (CEA), because no instable eigenvalue is found in the linearized equation of motion at that working point. This subcritical flutter-type behavior is known for small models in the literature and is examined in this paper with a more realistic brake system. It is found that the resulting error of the linearization cannot be neglected. Furthermore, different initial conditions are analyzed to narrow the zone of attraction of the stable limit cycle and the decrease of the critical friction value due to this kind of bifurcation behavior.
Mechanical Analysis of Vibrations in a Switched Reluctance Motor Using Experimental, Numerical, and Analytical Methodologies
Authors: Mathis Allen T. , Dane Quinn D. , El-Amin Mohammed , Sozer Yilmaz
Published: December 2018

Switched reluctance motors (SRM) are characterized by rotor/stator pole pairs, in which the wound field coils in the stator poles induce magnetic reluctance in the rotor poles to create torque. However, noise development during motor operation is a key issue for this class of motors and much of the work to understand the acoustics and vibrations of these systems is limited to comparing experimental measurements with high-performance, multiphysics simulations. This work focuses on mathematical analysis of these systems through reduced-order modeling using both numerical and analytical methods, and the results are compared against experimental measurements of a typical SRM. To describe the underlying response of the experimental system, a circular shell model is developed for the stator, and electromagnetic finite element analysis is utilized to develop a physically motivated forcing profile for the experimental system. A numerical simulation model is then constructed by applying the calculated electromagnetic forces to the stator, and effective system parameters are determined by calibrating the numerical model to match experimental measurements. An analytical approximation is then derived by leveraging disparate timescales in the problem, and it is shown that the analytical solution accurately recovers the numerical and experimental results while also providing insight into the underlying physics of the experimental system.
Magnetism in semiconducting molybdenum dichalcogenides
Authors: Guguchia Z. , Kerelsky A. , Edelberg D. , Banerjee S. , von Rohr F. , Scullion D. , Augustin M. , Scully M. , Rhodes D. A. , Shermadini Z. , Luetkens H. , Shengelaya A. , Baines C. , Morenzoni E. , Amato A. , Hone J. C. , Khasanov R. , Billinge S. J. L. , Santos E. , Pasupathy A. N. , Uemura Y. J.
Published: December 2018

Our experiments unambiguously establish 2H-MoTe
2
and 2H-MoSe
2
as magnetic, moderate bandgap semiconductors.
Freezing copper as a noble metal–like catalyst for preliminary hydrogenation
Authors: Sun Jian , Yu Jiafeng , Ma Qingxiang , Meng Fanqiong , Wei Xiaoxuan , Sun Yannan , Tsubaki Noritatsu
Published: December 2018

Copper is “frozen” into a metallic state as a noble metal–like catalyst for controlling the product in a chemical reaction.
Testing the paradigm of an ideal glass transition: Dynamics of an ultrastable polymeric glass
Authors: Yoon Heedong , McKenna Gregory B.
Published: December 2018

Measurements on nanogram samples of ultrastable polymer Teflon films challenge paradigms of the glass transition event.
Fluorinated solid electrolyte interphase enables highly reversible solid-state Li metal battery
Authors: Fan Xiulin , Ji Xiao , Han Fudong , Yue Jie , Chen Ji , Chen Long , Deng Tao , Jiang Jianjun , Wang Chunsheng
Published: December 2018

A principle of suppressing Li dendrite in solid-state electrolytes is proposed and demonstrated using LiF-rich SEI experimentally.
Electric field control of magnetic domain wall motion via modulation of the Dzyaloshinskii-Moriya interaction
Authors: Koyama Tomohiro , Nakatani Yoshinobu , Ieda Jun’ichi , Chiba Daichi
Published: December 2018

Magnetic domain wall speed exceeding 100 m/s is modulated by electrical gating of interfacial Dzyaloshinskii-Moriya interaction.
Designing self-propelled, chemically active sheets: Wrappers, flappers, and creepers
Authors: Laskar Abhrajit , Shklyaev Oleg E. , Balazs Anna C.
Published: December 2018

Chemically generated flows propel and sculpt deformable sheets into shapes that impart fluidic devices with new functionality.
What is the origin of macroscopic friction?
Authors: Sakuma H. , Kawai K. , Katayama I. , Suehara S.
Published: December 2018

The origin of macroscopic friction can be explained by the roughness of the potential energy surface of sliding planes.
The TNFRSF members CD27 and OX40 coordinately limit T
H
17 differentiation in regulatory T cells
Authors: Remedios Kelly A. , Zirak Bahar , Sandoval Priscila Munoz , Lowe Margaret M. , Boda Devi , Henley Evan , Bhattrai Shrishti , Scharschmidt Tiffany C. , Liao Wilson , Naik Haley B. , Rosenblum Michael D.
Published: December 2018

Skin-resident T
regs
suppress the T
H
17 pathway through a cell-intrinsic mechanism dependent on both CD27 and OX40.
Primary enterolithiasis with intestinal tuberculosis: rare presentation of a common disease
Authors: Singh Brijesh Kumar , Negi Saurabh , Meena Kusum , Singh Nain
Published: December 2018

Enterolithiasis is the formation of intestinal calculi due to stasis. Tubercular strictures resulting in intestinal stasis provide a favourable environment for enterolith formation. Intestinal tuberculosis occurs commonly in India, but coexistent enterolithiasis has been reported rarely. We are describing three cases of enterolithiasis secondary to tubercular intestinal strictures among female patients in the fourth to fifth decades of life, all of them having pulmonary tuberculosis in the past. All the cases presented with features of subacute intestinal obstruction. X-ray abdomen done for all of them revealed single to multiple round, oval and rectangular, radio-opaque shadows suggestive of stones. Coexistence of enterolithiasis with intestinal tuberculosis may worsen the symptoms of intestinal obstruction and surgery remains the mainstay of treatment. All the patients underwent exploratory laparotomy, resection and anastomosis of the diseased bowel and antitubercular therapy was started. Two patients responded well to the treatment and the third one expired due to cardiac comorbidity.
Unusual morphology of amyloid cast nephropathy in renal biopsy portending poor prognosis
Authors: Rajagopal Meyyappa Devan , Nachiappa Ganesh Rajesh , Parameswaran Sreejith , Puthiyottil Dhanin
Published: December 2018

Light chain cast nephropathy is the most frequent form of renal disease in plasma cell neoplasm showing precipitation of monoclonal immunoglobulin light chains in the lumen of the distal tubules. This has a typical morphological feature characterised by the presence of a fractured cast. In this article, we report an unusual case of light chain cast nephropathy exhibiting amyloidogenic potential with lamellated, spiculated appearance. These casts were positive for periodic acid–Schiff and Jones’ silver stain, fuchsinophilic in Masson trichrome stain and showed apple-green birefringence under polarised light in Congo red stain. Complete haematological evaluation confirmed the presence of underlying plasma cell myeloma. The connotation of intratubular amyloid cast lies in the fact that this may represent an early phenomenon during the development of light chain cast nephropathy-associated systemic amyloidosis and may precede the formation of light chain amyloid in renal or extrarenal location.
Lingual liability: macroglossia and dyspnoea as the harbinger of systemic AL (light-chain) cardiac amyloidosis
Authors: Williams Michael Uncle , Murphy Caroline E , Gore Rosco Steven , Fentanes Emilio
Published: December 2018

A 58-year-old man presented with a chief complaint of tongue indentations and discomfort. Otolaryngology treated him for oral thrush with counselling to avoid tongue biting. In addition, the patient reported dyspnoea described as a decrease in tolerance of his physical activities. Due to continued increase in tongue size and worsening dyspnoea, he underwent a tissue biopsy with findings consistent with amyloidosis. Further evaluation with a bone marrow biopsy revealed underlying multiple myeloma. Echocardiography revealed abnormal ventricular wall thickness, with a reduced left ventricular chamber size, dilated atria and Doppler findings with restrictive filling patterns indicative of cardiac amyloidosis. The patient was initiated on chemotherapy for his multiple myeloma and supportive therapy for his cardiac amyloidosis. Light-chain amyloidosis (AL) is a systemic disease characterised by irreversible deposition of amyloid in tissues throughout the body; when there is cardiac involvement, it can result in heart failure with a poor prognosis. Early diagnosis of cardiac amyloidosis can lead to prolonged survival.
Pulsatile nystagmus secondary to semicircular canal dehiscence
Authors: Hawwas Mohamed , Young Emily , Taneja Virangna , Rejali Darius
Published: December 2018

We report the case of a 69-year-old man with a history of mastoidectomy for cholesteatoma, who developed spontaneous spinning vertigo on debridement of his cavity. Subsequent CT confirmed a lateral semicircular canal fistula, which was surgically closed with mastoid cavity obliteration. Following surgery, he developed a spontaneous, pulse-synchronous horizontal pendular nystagmus. We discuss the pathophysiology of this rare clinical sign.
Pleuropulmonary tuberculosis with spinal lesions due to metastatic malignancy differentiated definitively on imaging
Authors: Gibson Justine , Coucher John , Coulter Chris , Eather Geoffrey
Published: December 2018

A healthy 31-year-old man presenting with back pain was found to have multiple spinal enhancing lesions on MRI. An incidental asymptomatic large pleural effusion was identified on investigations for the back pain and pleural and pulmonary tuberculosis (TB) was subsequently diagnosed. The radiographical features on MRI spine were not typical of spinal TB and a Ga68 DOTATATE Positron Emission Tomography (PET)/CT confirmed metastatic paraganglioma with multiple bone metastases. Although metastatic paraganglioma is rare, this case highlights that even in young patients dual pathology needs to be considered. Most importantly, it is a reminder to physicians managing TB of the clues that help distinguish spinal TB from important alternative causes, including metastatic malignancy.
Early presentation of vertebral osteomyelitis following a transrectal ultrasound-guided prostate biopsy with delayed radiological findings
Authors: Kalenderov Rayko , Soukratos Nikolas , Kirat Rai Prabesh , Warsi Ali
Published: December 2018

A transrectal ultrasound-guided (TRUS) prostate biopsy is a common diagnostic procedure which carries an expected risk of iatrogenic infections. These range from simple urinary tract infections to rare but serious infections requiring an admission to hospital. Here we present a rare case of vertebral osteomyelitis following a TRUS biopsy, with normal initial MRI and bone scintigraphy scans and delayed radiological findings on repeat MRI of the spine.
Chlamydiaascites: a call for sexually transmitted infection testing
Authors: Halford Brittne , Piazza Mariah Barstow , Liu David , Obineme Chuma
Published: December 2018

A 26-year-old gravida 2, para 2-0-0-2 woman with a recent uncomplicated vaginal delivery 10 weeks prior presented to our hospital with 5 weeks of abdominal swelling and discomfort. Four weeks after delivery, the patient began having right upper quadrant pain and was found to have cholelithiasis. She underwent an elective laparoscopic cholecystectomy 6 weeks prior to admission, but started to develop worsening abdominal swelling 1 week postoperatively. Abdominal distension and shifting dullness were present on examination. CT of the abdomen and pelvis was remarkable for moderate-volume ascites and mild enhancement of the pelvic peritoneum. Paracentesis removed 2.46 L of ascites fluid with 76% lymphocytic predominance. Results forChlamydia trachomatiswere positive in urine, cervical swab and ascitic fluid. Doxycycline was prescribed for a diagnosis of pelvic inflammatory disease exudative ascites. Since discharge, she has completed her antibiotic course and reports resolution of all symptoms without recurrence of ascites.
Removing the problem: parathyroidectomy for calciphylaxis
Authors: Hassanein Mohamed , Laird-Fick Heather , Tikaria Richa , Aldasouqi Saleh
Published: December 2018

Calcific uremic arteriolopathy (CUA), widely known as calciphylaxis, is a rare and lethal disease that usually affects patients with end-stage renal disease. It is characterised by widespread vascular calcification leading to tissue ischaemia and necrosis and formation of characteristic skin lesions with black eschar. Treatment options include sodium thiosulfate, cinacalcet, phosphate binders and in resistant cases, parathyroidectomy. We report a case of recurrent, treatment-resistant CUA successfully treated with parathyroidectomy. Her postoperative course was complicated by hungry bone syndrome and worsening of her wounds before they completely healed. We then discuss the morbidity of CUA, including the controversy around the use of parathyroidectomy and risk of aggressive management of hungry bone syndrome.
Unusual presentation of eosinophilic fasciitis (EF) with a raised ALT
Authors: Batty Thomas , Majeed Shuja , Wlodek Christina , Gunawardena Harsha
Published: December 2018

Eosinophilic fasciitis (EF) is a syndrome of unknown aetiology characterised by progressive collagenous thickening of the subcutaneous fascia. Limb oedema can precede the skin thickening and induration classically associated with EF. We describe a case of EF in a 31-year-old woman who presented to her general practitioner with lower limb oedema and stiffness. Blood tests in primary care showed a persistently raised alanine transferase (ALT). No hepatic cause for her raised ALT was found despite investigation. The unusual manner of her presentation led to delay in her referral to the autoimmune connective tissue disease (CTD) clinic. This case illustrates the importance of considering autoimmune CTD such as EF in young patients presenting with limb oedema and raised ALT, as early treatment influences prognosis and functional recovery.
Bone stress injuries in male distance runners: higher modified Female Athlete Triad Cumulative Risk Assessment scores predict increased rates of injury
Authors: Kraus Emily , Tenforde Adam S , Nattiv Aurelia , Sainani Kristin L , Kussman Andrea , Deakins-Roche Megan , Singh Sonal , Kim Brian Young , Barrack Michelle T , Fredericson Michael
Published: December 2018

Objectives

Bone stress injuries (BSI) are common in runners of both sexes. The purpose of this study was to determine if a modified Female Athlete Triad Cumulative Risk Assessment tool would predict BSI in male distance runners.

Methods

156 male runners at two collegiate programmes were studied using mixed retrospective and prospective design for a total of 7 years. Point values were assigned using risk assessment categories including low energy availability, low body mass index (BMI), low bone mineral density (BMD) and prior BSI. The outcome was subsequent development of BSI. Statistical models used a mixed effects Poisson regression model with p<0.05 as threshold for significance. Two regression analyses were performed: (1) baseline risk factors as the independent variable; and (2) annual change in risk factors (longitudinal data) as the independent variable.

Results

42/156 runners (27%) sustained 61 BSIs over an average 1.9 years of follow-up. In the baseline risk factor model, each 1 point increase in prior BSI score was associated with a 57% increased risk for prospective BSI (p=0.0042) and each 1 point increase in cumulative risk score was associated with a 37% increase in prospective BSI risk (p=0.0079). In the longitudinal model, each 1 point increase in cumulative risk score was associated with a 27% increase in prospective BSI risk (p=0.05). BMI (rate ratio (RR)=1.91, p=0.11) and BMD (RR=1.58, p=0.19) risk scores were not associated with BSI.

Conclusion

A modified cumulative risk assessment tool may help identify male runners at elevated risk for BSI. Identifying risk factors may guide treatment and prevention strategies.
Can the STarT Back Tool predict health-related quality of life and work ability after an acute/subacute episode with back or neck pain? A psychometric validation study in primary care
Authors: Forsbrand Malin H , Grahn Birgitta , Hill Jonathan C , Petersson Ingemar F , Post Sennehed Charlotte , Stigmar Kjerstin
Published: December 2018

Objectives

The predictive ability of the STarT Back Tool (SBT) has not yet been examined among acute/subacute back and/or neck pain in a primary care setting in respect to health-related quality of life (HRQoL) and work ability outcomes. The aim of this study was to evaluate the SBT’s predictive validity for HRQoL and work ability outcomes at long-term follow-up in a population with acute/subacute back and/or neck pain.

Setting

Prospective data from 35 primary care centres in south Sweden during 2013.

Participants

Patients (n=329) with acute/subacute back and/or neck pain, aged 18–67 years, not on sick leave or <60 days of sick leave completed the SBT when applying for physiotherapy treatment. Long-term follow-up measures (median 13 months, range 11–27 months) of HRQoL (EQ-5D) and work ability (Work Ability Score) was completed by 238 patients (72%).

Outcomes

The predictive ability of the SBT for HRQoL and work ability outcomes was examined using Kruskal-Wallis test, logistic regression and area under the curve (AUC).

Results

Based on SBT risk group stratification, 103 (43%), 107 (45%) and 28 (12%) patients were considered as low, medium and at high risk, respectively. There were statistically significant differences in HRQoL (p<0.001) and work ability (p<0.001) at follow-up between all three SBT risk groups. Patients in the high risk group had a significantly increased risk of having poor HRQoL (OR 6.16, 95% CI 1.50 to 25.26) and poor work ability (OR 5.08, 95% CI 1.75 to 14.71) vs the low risk group at follow-up. The AUC was 0.73 (95% CI 0.61 to 0.84) for HRQoL and 0.68 (95% CI 0.61 to 0.76) for work ability.

Conclusions

The SBT is an appropriate tool for identifying patients with a poor long-term HRQoL and/or work ability outcome in a population with acute/subacute back and/or neck pain, and maybe a useful adjunct to primary care physiotherapy assessment and practice.

Trial registration number

NCT02609750; Results.
Association of workplace social capital with psychological distress: results from a longitudinal multilevel analysis of the J-HOPE Study
Authors: Eguchi Hisashi , Tsutsumi Akizumi , Inoue Akiomi , Hikichi Hiroyuki , Kawachi Ichiro
Published: December 2018

Objectives

Workplace social capital (WSC) is increasingly recognised as a social contextual determinant of workers’ mental health, but longitudinal data are sparse. We aimed to evaluate the impact of changes in unit-level WSC on psychological distress among Japanese employees using a prospective multilevel repeated-measures design.

Participants and study design

We conducted a 2-year prospective cohort study with 1,944 men and 786 women aged 18–65 years. Participants worked at two manufacturing worksites in Japan and were free from mental illness from the first to third study waves. We used a three-level multilevel regression design to evaluate the prospective association of unit-level WSC with individual-level psychological distress. WSC was measured using a validated six-item instrument and individual-level psychological distress with the Kessler Psychological Distress Scale (K6).

Results

The null model indicated a significant degree of between-work unit variation in psychological distress (intraclass correlation=0.1%, p<0.001). In the full model, each SD increase in unit-level WSC was associated with 0.69 point improvement in K6 scores (95% CI −1.12 to −0.26).

Conclusions

This prospective study builds on existing knowledge by showing an association between unit-level WSC and modest improvements in mental health among employees in Japan. We recommend that WSC is considered alongside other contextual influences when assessing employees’ mental health risks.
Design and validity of a questionnaire to assess national eHealth architecture (NEHA): a study protocol
Authors: Mousavi Seyyed Meysam , Takian Amirhossein , Tara Mahmood
Published: December 2018

Introduction

eHealth is critically important to build strong health systems, and accelerate the achievement of sustainable development goals, particularly universal health coverage. To support and strengthen the health system, the eHealth architecture needs to be formulated and established prior to the implementation and development of any national eHealth applications and services. The aim of this study is to design and validate a standard questionnaire to assess the current status of national eHealth architecture (NEHA) components.

Methods and analysis

This study will use a mixed-methods design consisting of four phases: (1) item generation through review of evidences and experts’ opinions, (2) face and content validity of the questionnaire, (3) determination of a range of possible scenarios for each item included in the questionnaire and (4) evaluation of reliability. This questionnaire is expected to generate critical and important information about the status of NEHA components that will be useful for monitoring, formulating, developing, implementing and evaluating NEHA. Our paper will contribute, we envisage, to establishment of a socio-technical basis on which governments and other relevant sectors can compare the policy interventions that boost the availability and utilisation of eHealth services within their settings.

Ethics and dissemination

The Ethics Committee for Research at the Tehran University of Medical Sciences approved the study protocol. We will obtain informed consent from each participant and collect data anonymously to maintain confidentiality. The translation of the findings into future policy planning will include the production of a series of peer-reviewed articles, presentation of the findings at relevant eHealth conferences and preparation of policy reports to the international organisations aiming to strengthen national capacity for better-informed eHealth architecture.
A randomised controlled trial to assess whether prehabilitation improves fitness in patients undergoing neoadjuvant treatment prior to oesophagogastric cancer surgery: study protocol
Authors: Allen Sophie , Brown Vanessa , Prabhu Pradeep , Scott Michael , Rockall Timothy , Preston Shaun , Sultan Javed
Published: December 2018

Introduction

Neoadjuvant therapy prior to oesophagogastric resection is the gold standard of care for patients with T2 and/or nodal disease. Despite this, studies have taught us that chemotherapy decreases patients’ functional capacity as assessed by cardiopulmonary exercise (CPX) testing. We aim to show that a multimodal prehabilitation programme, comprising supervised exercise, psychological coaching and nutritional support, will physically, psychologically and metabolically optimise these patients prior to oesophagogastric cancer surgery so they may better withstand the immense physical and metabolic stress placed on them by radical curative major surgery.

Methods and analysis

This will be a prospective, randomised, controlled, parallel, single-centre superiority trial comparing a multimodal ‘prehabilitation’ intervention with ‘standard care’ in patients with oesophagogastric malignancy who are treated with neoadjuvant therapy prior to surgical resection. The primary aim is to demonstrate an improvement in baseline cardiopulmonary function as assessed by anaerobic threshold during CPX testing in an interventional (prehab) group following a 15-week preoperative exercise programme, throughout and following neoadjuvant treatment, when compared with those that undergo standard care (control group). Secondary objectives include changes in peak oxygen uptake and work rate (total watts achieved) at CPX testing, insulin resistance, quality of life, chemotherapy-related toxicity and completion, nutritional assessment, postoperative complication rate, length of stay and overall mortality.

Ethics and dissemination

This study has been approved by the London-Bromley Research Ethics Committee and registered on ClinicalTrials.gov. The results will be disseminated in a peer-reviewed journal.

Trial registration number

NCT02950324; Pre-results.
Life after the loss: protocol for a Danish longitudinal follow-up study unfolding life and grief after the death of a child during pregnancy from gestational week 14, during birth or in the first 4 weeks of life
Authors: Hvidtjørn Dorte , Prinds Christina , Bliddal Mette , Henriksen Tine Brink , Cacciatore Joanne , O’Connor Maja
Published: December 2018

Introduction

After the death of a child during pregnancy, birth or in the neonatal period, parents often experience feelings of guilt, disenfranchisement, feelings of betrayal by one’s own body and envy of others. Such bereavement results in high rates of distress: psychologically, emotionally, physiologically and existentially. These data are collected using a national, longitudinal cohort to assess grief in mothers and their partners after the death of a child during pregnancy, birth or in the neonatal period. Our aim is to achieve a general description of grief, emotional health, and existential values after pregnancy or perinatal death in a Danish population.

Methods and analysis

The cohort comprises mothers and their partners in Denmark who lost a child during pregnancy from gestational week 14, during birth or in the neonatal period (4 weeks post partum). We began data collection in 2015 and plan to continue until 2024. The aim is to include 5000 participants by 2024, generating the largest cohort in the field to date. Parents are invited to participate at the time of hospital discharge or via the Patient Associations homepage. Data are collected using web-based questionnaires distributed at 1–2, 7 and 13 months after the loss. Sociodemographic and obstetric variables are collected. Validated psychometric measures covering attachment, continuing bonds, post-traumatic stress, prolonged grief, perinatal grief and existential values were chosen to reach our aim.

Ethics and dissemination

The study was approved by The Danish National Data Protection Agency (no. 18/15684, 7 October 2014). The results will be disseminated in peer-reviewed and professional journals as well as in layman magazines, lectures and radio broadcasts.
Anaemia among primary care patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD): a multicentred cross-sectional study
Authors: Idris Iliza , Tohid Hizlinda , Muhammad Noor Azimah , A Rashid Mohd Radzniwan , Mohd Ahad Azainorsuzila , Ali Norsiah , Sharifuddin Naemah , Aris Junita Harizon
Published: December 2018

Objectives

This study aimed to determine the prevalence of anaemia among patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) at primary care settings and its associated factors.

Design, setting and participants

This cross-sectional study involved 808 adult patients with T2DM and CKD who were recruited via systematic sampling from 20 public primary care clinics in Peninsular Malaysia. Their sociodemographic, clinical and biomedical profiles were collected through interviews, examination of medical records and blood testing.

Results

The prevalence of anaemia was 31.7% (256/808). The anaemia was mainly mild (61.5%) and normocytic normochromic (58.7%). About 88.7% of the patients with anaemia were not known to have anaemia prior to the study. Among 36 patients with documented history of anaemia, 80.6% were still anaemic, and only a half received iron therapy. Multivariate regression analysis showed that women (adjusted odd ratio (AOR): 1.57, 95% CI: 1.12 to 2.21, p=0.009) and those with older age (AOR: 1.04, 95% CI: 1.01 to 1.06, p<0.001), CKD stage 3a (AOR: 2.47; 95% CI: 1.25 to 4.87, p=0.009), CKD stage 3b (AOR: 4.36; 95% CI: 2.14 to 8.85, p<0.001), CKD stage 4 (AOR: 10.12; 95% CI: 4.36 to 23.47, p<0.001), CKD stage 5 (AOR: 10.80; 95% CI: 3.32 to 35.11, p<0.001) and foot complication (AOR 3.12, 95% CI: 1.51 to 6.46, p=0.002) were more likely to have anaemia. Having higher body mass index (AOR 0.95, 95% CI: 0.92 to 0.99, p=0.012) and higher diastolic blood pressure (AOR 0.97, 95% CI: 0.95 to 0.99, p<0.001) were associated with lower odds to have anaemia.

Conclusion

Anaemia among patients with T2DM and CKD in primary care was common, and the majority was unrecognised. Inadequate treatment of anaemia was also prevalent. Therefore, screening of anaemia should be incorporated into the routine assessment of diabetic complications particularly for those with significant associated factors. It is hoped that such strategy could lead to early treatment and hence improve their overall care.

Trial registration number

NMRR-15-660-24324.
Randomised controlled study comparing general and spinal anaesthesia with and without a tourniquet on the outcomes of total knee arthroplasty: study protocol
Authors: Rantasalo Mikko Tuomas , Palanne Riku , Juutilainen Katarina , Kairaluoma Pekka , Linko Rita , Reponen Elina , Helkamaa Teemu , Vakkuri Anne , Olkkola Klaus T , Madanat Rami , Skants Noora Kati Annukka
Published: December 2018

Introduction

Total knee arthroplasty is a highly effective treatment for end-stage knee osteoarthritis, and it is usually performed under spinal or general anaesthesia with or without a surgical tourniquet. Some debate about the preferred mode of anaesthesia regarding patient outcomes remains. The aim of this study, which compares general and spinal anaesthesia with and without a tourniquet on the outcomes of total knee arthroplasty, is to determine the optimal type of anaesthesia regimen and assess the effect of a tourniquet on the patient’s recovery following total knee arthroplasty.

Methods and analysis

This study is a randomised, controlled, parallel-group, four-arm study comparing spinal and general anaesthesia with and without a tourniquet in 400 patients undergoing fast-track total knee arthroplasty, with a 12-month follow-up. The primary outcome is cumulative intravenous oxycodone consumption by patient-controlled analgesia during the first 24 postoperative hours. Secondary outcomes include postoperative nausea and vomiting, the length of hospital stay, the duration of the surgery, blood loss, demand for surgical unit resources, complications, readmissions, postoperative knee function, range of motion, health-related quality of life, prolonged pain and mortality.

Ethics and dissemination

This study’s protocol is in accordance with the declaration of Helsinki. The results of this study will be disseminated in international peer-reviewed journals.

Trial registration number

NCT03364088; Pre-results.
Investigating locally relevant risk factors forCampylobacterinfection in Australia: protocol for a case–control study and genomic analysis
Authors: Varrone Liana , Stafford Russell J , Lilly Kim , Selvey Linda , Glass Kathryn , Ford Laura , Bulach Dieter , Kirk Martyn D
Published: December 2018

Introduction

The CampySource project aims to identify risk factors for humanCampylobacterinfection in Australia. We will investigate locally relevant risk factors and those significant in international studies in a case–control study. Case isolates and contemporaneous isolates from food and animal sources will be sequenced to conduct source attribution modelling, and findings will be combined with the case–control study in a source-assigned analysis.

Methods and analysis

The case–control study will include 1200 participants (600 cases and 600 controls) across three regions in Australia. Cases will be recruited from campylobacteriosis notifications to health departments. Only those with a pure and viableCampylobacterisolate will be eligible for selection to allow for whole genome sequencing of isolates. Controls will be recruited from notified cases of influenza, frequency matched by sex, age group and geographical area of residence. All participants will be interviewed by trained telephone interviewers using a piloted questionnaire.

We will collectCampylobacterisolates from retail meats and companion animals (specifically dogs), and all food, animal and human isolates will undergo whole genome sequencing. We will use sequence data to estimate the proportion of human infections that can be attributed to animal and food reservoirs (source attribution modelling), and to identify spatial clusters and temporal trends. Source-assigned analysis of the case–control study data will also be conducted where cases are grouped according to attributed sources.

Ethics and dissemination

Human and animal ethics have been approved. Genomic data will be published in online archives accompanied by basic metadata. We anticipate several publications to come from this study.
My approach to water-assisted colonoscopy
Authors: Siau Keith , Beintaris Iosif
Published: December 2018

The goal of diagnostic colonoscopy is to achieve procedural completion while maximising effectiveness, patient acceptance and safety. In recent years, international interest in water-assisted colonoscopy (WAC) has been steadily gathering pace. A plethora of high-quality randomised controlled trials and meta-analyses now offer incontrovertible evidence into the benefits of WAC, both for the endoscopist and the patient. Despite this, uptake of WAC within the UK has been limited, with the lack of educational resources representing a significant barrier. This practical step-by-step guide is aimed at both existing practitioners and trainees, with a view to promoting familiarity with WAC and potentially for incorporation into daily practice which may ultimately have a positive effect on quality of colonoscopy and patient experience.
Advanced endoscopic techniques in the assessment of inflammatory bowel disease: new technology, new era
Authors: Iacucci Marietta , Furfaro Federica , Matsumoto Takayuki , Uraoka Toshio , Smith Samuel , Ghosh Subrata , Kiesslich Ralf
Published: December 2018

Endoscopic assessment of inflammation and mucosal healing is crucial for appropriate management in IBD. Current definition of endoscopic mucosal healing has been derived using previous generation of standard white light endoscopes. New endoscopy technologies widely available provide much more detailed images of mucosal and vascular patterns. Novel endoscopic techniques with high definition image, optical and digital enhancement have enhanced the quality and fine details of vascular and mucosal pattern so that endoscopic images have started to reflect histological changes for lesions and inflammation/healing. These technologies can now define subtle inflammatory changes and increase detection and characterisation of colonic lesions in patients with IBD. The best endoscopic technique to detect dysplasia in IBD is still debated. Dye chromoendoscopy with targeted biopsies is considered by Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in inflammatory Bowel Disease Patients: International Consensus Recommendations (SCENIC consensus the standard of care and recommended for adoption by gastroenterologists in practice. In future, it is possible that well-trained colonoscopists using high definition equipment with image enhancements may be able to obtain equivalent yield without pan-colonic dye spraying and characterise lesions. Finally, SCENIC introduced endoscopic resectability of some dysplastic colonic lesions—new techniques may now better characterise endoscopic resectability and limit the number of colectomies. In this review, we will provide a state-of-the-art opinion on the direction of technological advances in the assessment of IBD and how new concepts will refine clinical practice.
Should pretest genetic counselling be required for patients pursuing genomic sequencing? Results from a survey of participants in a large genomic implementation study
Authors: Pacyna Joel E , Radecki Breitkopf Carmen , Jenkins Sarah M , Sutton Erica J , Horrow Caroline , Kullo Iftikhar J , Sharp Richard R
Published: December 2018

Purpose

We assessed the decision-making of individuals pursuing genomic sequencing without a requirement for pretest genetic counselling. We sought to describe the extent to which individuals who decline genetic counselling reported decisional conflict or struggled to make a decision to pursue genomic testing.

Methods

We administered a 100-item survey to 3037 individuals who consented to the Return of Actionable Variants Empirical study, a genomic medicine implementation study supported by the National Institutes of Health (USA) eMERGE consortium. The primary outcomes of interest were self-reported decisional conflict about the decision to participate in the study and time required to reach a decision.

Results

We received 2895 completed surveys (response rate=95.3%), and of these respondents 97.8% completed the decisional conflict scale in its entirety. A majority of individuals (63%) had minimal or no decisional conflict about the pursuit of genomic sequencing and were able to reach a decision quickly (78%). Multivariable logistic regression analyses identified several characteristics associated with decisional conflict, including lower education, lower health literacy, lower self-efficacy in coping, lack of prior experience with genetic testing, not discussing study participation with a family member or friend, and being male.

Conclusion

As genomic sequencing is used more widely, genetic counselling resources may not be sufficient to meet demand. Our results challenge the notion that all individuals need genetic counselling in order to make an informed decision about genomic sequencing.