bluuebunny/crossref_metadata_2025 huggingface dataset:
Redesigning a Reaction Control Thruster for Metal-Based Additive Manufacturing: A Case Study in Design for Additive Manufacturing
Authors: Meisel Nicholas A. , Woods Matthew R. , Simpson Timothy W. , Dickman Corey J.
Published: July 2017

Prior research has shown that powder-bed fusion (PBF) additive manufacturing (AM) can be used to make functional, end-use components from powdered metallic alloys, such as Inconel® 718 superalloy. However, these end-use components and products are often based on designs developed for more traditional subtractive manufacturing processes and do not take advantage of the unique design freedoms afforded by AM. In this paper, we present a case study involving the redesign of NASA’s existing “pencil” thruster used for spacecraft attitude control. The initial pencil thruster was designed for and manufactured using traditional subtractive methods. The main focus in this paper is to (a) identify the need for and use of both opportunistic and restrictive design for additive manufacturing (DfAM) concepts and considerations in redesigning the thruster for fabrication with PBF AM and (b) compare the resulting DfAM thruster with a parallel development effort redesigning the original thruster to be manufactured more effectively using subtractive manufacturing processes. The results from this case study show how developing end-use AM components using specific DfAM guidelines can significantly reduce manufacturing time and costs while enabling new and novel design geometries.
Design and Evaluation of a Balance Assistance Control Moment Gyroscope
Authors: Lemus Daniel , van Frankenhuyzen Jan , Vallery Heike
Published: July 2017

We recently proposed the theoretical idea of a wearable balancing aid, consisting of a set of control moment gyroscopes (CMGs) contained into a backpacklike orthopedic corset. Even though similar solutions have been reported in the literature, important considerations in the synthesis and design of the actuators remained to be addressed. These include design requirements such as aerodynamic behavior of the spinning flywheel, induced dynamics by the wearer's motion, and stresses in the inner components due to the generated gyroscopic moment. In this paper, we describe the design and evaluation of a single CMG, addressing in detail the aforementioned requirements. In addition, given the application of the device in human balance, the design follows the European directives for medical electrical equipment. The developed system was tested in a dedicated balance test bench showing good agreement with the expected flywheel speed, and calculated power requirements in the actuators and output gyroscopic moment. The device was capable of producing a peak gyroscopic moment of approximately 70 N·m with a total CMG mass of about 10 kg.
Design and Fabrication of a Low-Cost Three-Dimensional Bioprinter
Authors: McElheny Colton , Hayes Daniel , Devireddy Ram
Published: July 2017

Three-dimensional (3D) bioprinting offers innovative research vectors for tissue engineering. However, commercially available bioprinting platforms can be cost prohibitive to small research facilities, especially in an academic setting. The goal is to design and fabricate a low-cost printing platform able to deliver cell-laden fluids with spatial accuracy along the X, Y, and Z axes of 0.1 mm. The bioprinter consists of three subassemblies: a base unit, a gantry, and a shuttle component. The platform utilizes four stepper motors to position along three axes and a fifth stepper motor actuating a pump. The shuttle and gantry are each driven along their respective horizontal axes via separate single stepper motor, while two coupled stepper motors are used to control location along the vertical axis. The current shuttle configuration allows for a 5 mL syringe to be extruded within a work envelope of 180 mm × 160 mm × 120 mm (X, Y, Z). The shuttle can easily be reconfigured to accommodate larger volume syringes. An attachment for a laser pen is located such that printing material may be light-activated pre-extrusion. Positional fidelity was established with calipers possessing a resolution to the nearest hundredth millimeter. The motors associated with the X and Y axes were calibrated to approximately 0.02 mm per motor impulse. The Z axis has a theoretical step distance of ∼51 nm, generating 0.04% error over a 10 mm travel distance. The A axis, or pump motor, has an impulse distance of 0.001 mm. The volume extruded by a single impulse is dictated by the diameter of the syringe used. With a 5 mL syringe possessing an inner diameter of 12.35 mm, the pump pushes as little as 0.119 μL. While the Z axis is tuned to the highest resolution settings for the motor driver, the X, Y, and A axes can obtain higher or lower resolution via physical switches on the motor drivers.
Experimental Investigation on Vortex Shedding and Fluid Elastic Instability in Finned Tube Arrays Subjected to Water Cross Flow
Authors: Desai Sandeep R. , Pavitran S.
Published: July 2017

The paper presents results of an experimental study on fluid elastic instability and vortex shedding in plain and finned arrays exposed to water cross flow. The parallel triangular array with cantilever end condition is considered for the study. Pitch ratios considered are 2.1 and 2.6 while fin densities considered are 4 fpi (fins per inch) and 10 fpi. The results for critical velocity at instability for two finned tube arrays are presented. Apart from results on fluid elastic vibration behavior, extensive results on vortex shedding are also presented to study the phenomenon in tube arrays subjected to water cross flow. The test parameters measured are water flow rate, natural frequency, and vibration amplitudes of the tubes. The datum case results were first obtained by testing plain arrays with pitch ratios 2.1 and 2.6. This was then followed by experiments with finned arrays with pitch ratios 2.1 and 2.6, and each with two different fin densities. The higher pitch ratios typical of chemical process industries resulted in the delayed instability threshold due to weak hydrodynamic coupling between the neighboring tubes. The results indicated that finned arrays are more stable in water cross flow compared to plain arrays. The Strouhal numbers corresponding to small peaks observed before fluid elastic instability are computed and compared with the expected ones according to Owen's hypothesis. It was concluded that peaks observed are attributed to vortex shedding observed for all the arrays tested in water.
Recognition of asynchronous auditory-visual speech by younger and older listeners: A preliminary study
Authors: Gordon-Salant Sandra , Yeni-Komshian Grace H. , Fitzgibbons Peter J. , Willison Hannah M. , Freund Maya S.
Published: July 2017

This study examined the effects of age and hearing loss on recognition of speech presented when the auditory and visual speech information was misaligned in time (i.e., asynchronous). Prior research suggests that older listeners are less sensitive than younger listeners in detecting the presence of asynchronous speech for auditory-lead conditions, but recognition of speech in auditory-lead conditions has not yet been examined. Recognition performance was assessed for sentences and words presented in the auditory-visual modalities with varying degrees of auditory lead and lag. Detection of auditory-visual asynchrony for sentences was assessed to verify that listeners detected these asynchronies. The listeners were younger and older normal-hearing adults and older hearing-impaired adults. Older listeners (regardless of hearing status) exhibited a significant decline in performance in auditory-lead conditions relative to visual lead, unlike younger listeners whose recognition performance was relatively stable across asynchronies. Recognition performance was not correlated with asynchrony detection. However, one of the two cognitive measures assessed, processing speed, was identified in multiple regression analyses as contributing significantly to the variance in auditory-visual speech recognition scores. The findings indicate that, particularly in auditory-lead conditions, listener age has an impact on the ability to recognize asynchronous auditory-visual speech signals.
In a major shift, cancer drugs go‘tissue-agnostic’
Authors: Garber Ken
Published: July 2017

Encouraged by an FDA approval, companies design cancer drugs to work in any solid tumor.
Europe's top court alarms vaccine experts
Authors: Vogel Gretchen
Published: July 2017

Patients can plead for damages even in the absence of scientific evidence, judges say.
South Korea's nuclear U-turn draws praise and darts
Authors: Normile Dennis
Published: July 2017

New president pushes dramatic shift in energy policy
Quantum correlations from a room-temperature optomechanical cavity
Authors: Purdy T. P. , Grutter K. E. , Srinivasan K. , Taylor J. M.
Published: July 2017

Quantum effects in ambient conditions

Quantum back action—the “reaction” of a quantum mechanical object to being measured—is normally observed at cryogenic temperatures, where it is easier to distinguish from thermal motion. Purdy
et al.
managed to tease out the effects of quantum back action at room temperature by using a mechanical oscillator and probing it with light (see the Perspective by Harris). The fluctuations of the force produced by the light probe caused correlated changes to the motion of the oscillator and the properties of the transmitted light. These correlations revealed the effects of the back action, which allows the system to be used as a quantum thermometer.

Science
, this issue p.
1265
; see also p.
1232
Quantized electric multipole insulators
Authors: Benalcazar Wladimir A. , Bernevig B. Andrei , Hughes Taylor L.
Published: July 2017

Corner-dwelling topological states

Computing the electric polarization of a crystal is surprisingly tricky, but it can be tackled with the help of a topological concept, the so-called Berry phase. Extensions to higher multiple moments, such as quadrupole and octupole, are even trickier. Benalcazar
et al.
built a theoretical framework for dealing with these moments in certain types of solids. In the presence of some crystalline symmetries, the quadrupole moment is quantized, and the corners of the system play host to fractionally charged, topologically protected states. These predictions may be testable in cold atom and photonic systems.

Science
, this issue p.
61
Local protein kinase A action proceeds through intact holoenzymes
Authors: Smith F. Donelson , Esseltine Jessica L. , Nygren Patrick J. , Veesler David , Byrne Dominic P. , Vonderach Matthias , Strashnov Ilya , Eyers Claire E. , Eyers Patrick A. , Langeberg Lorene K. , Scott John D.
Published: July 2017

PKA-activation mechanism revised

Many hormone receptors stimulate production of cyclic AMP (adenosine monophosphate), which activates PKA (protein kinase A). The textbook view suggests that activation releases the catalytic subunit of the enzyme from its complex with the regulatory subunit. Smith
et al.
closely monitored activation of PKA in cultured human cells and found that dissociation of the holoenzyme was not necessary for activation. The kinase, which binds anchoring proteins that localize it in the cell, appears to be restricted to acting within about 200 Å of such anchoring proteins. Thus, PKA activity is more precisely targeted within the cell than previously anticipated.

Science
, this issue p.
1288
Seasonal water storage, stress modulation, and California seismicity
Authors: Johnson Christopher W. , Fu Yuning , Bürgmann Roland
Published: July 2017

Microseismicity is modulated by the seasonal hydrological cycle in California.
Click chemistry enables preclinical evaluation of targeted epigenetic therapies
Authors: Tyler Dean S. , Vappiani Johanna , Cañeque Tatiana , Lam Enid Y. N. , Ward Aoife , Gilan Omer , Chan Yih-Chih , Hienzsch Antje , Rutkowska Anna , Werner Thilo , Wagner Anne J. , Lugo Dave , Gregory Richard , Ramirez Molina Cesar , Garton Neil , Wellaway Christopher R. , Jackson Susan , MacPherson Laura , Figueiredo Margarida , Stolzenburg Sabine , Bell Charles C. , House Colin , Dawson Sarah-Jane , Hawkins Edwin D. , Drewes Gerard , Prinjha Rab K. , Rodriguez Raphaël , Grandi Paola , Dawson Mark A.
Published: July 2017

Are better drugs just a click away?

Drugs that show promise in preclinical models often fail in the clinic, in part because of limited information on drug localization within cells and across tissues. In a proof-of-concept study, Tyleret al.applied click chemistry methods to study the localization of bromodomain inhibitors. These are cancer drugs that alter chromatin structure and gene expression. Clickable derivatives of the drugs localized within chromatin and showed that the drugs exhibit distinct modes of binding at responsive and unresponsive genes. In a mouse leukemia model, the click-probes revealed that the drugs accumulate to different extents in the spleen and bone marrow, which are two tissue sources of leukemic cells.

Science, this issue p.1397
Estimating economic damage from climate change in the United States
Authors: Hsiang Solomon , Kopp Robert , Jina Amir , Rising James , Delgado Michael , Mohan Shashank , Rasmussen D. J. , Muir-Wood Robert , Wilson Paul , Oppenheimer Michael , Larsen Kate , Houser Trevor
Published: July 2017

Costing out the effects of climate change

Episodes of severe weather in the United States, such as the present abundance of
rainfall in California, are brandished as tangible evidence of the future costs of
current climate trends. Hsiang
et al.
collected national data
documenting the responses in six economic sectors to short-term weather fluctuations.
These data were integrated with probabilistic distributions from a set of global climate
models and used to estimate future costs during the remainder of this century across a
range of scenarios (see the Perspective by Pizer). In terms of overall effects on gross
domestic product, the authors predict negative impacts in the southern United States and
positive impacts in some parts of the Pacific Northwest and New England.

Science
, this issue p.
1362
; see also p.
1330
Cognitive science in the field: A preschool intervention durably enhances intuitive but not formal mathematics
Authors: Dillon Moira R. , Kannan Harini , Dean Joshua T. , Spelke Elizabeth S. , Duflo Esther
Published: July 2017

Developing curricula for developing countries

Many children in developing countries grow up in economically poor environments and often also suffer from poorly performing educational systems. Dillon
et al.
designed inexpensive, locally sourced games—five for mathematics and five for social cognition—for use in preschools in Delhi. They measured the effects of these interventions 3, 9, and 15 months later. Compared with those who played social games, the kids who played math games showed enhanced performance on both nonsymbolic and symbolic math assessments at the 3-month time point. However, only the nonsymbolic improvements persisted for as long as a year.

Science
, this issue p.
47
Response to Comment on “Xist recruits the X chromosome to the nuclear lamina to enable chromosome-wide silencing”
Authors: Chen Chun-Kan , Chow Amy , Lai Mason , Guttman Mitchell
Published: July 2017

Wang
et al
. question whether Lamin B receptor is required for Xist-mediated silencing because they claim that our cells contain an inversion rather than a deletion. We present evidence that these cells contain a proper deletion and that the confusion is caused by DNA probes used in the experiment. Accordingly, the points raised have no effect on the conclusions in our paper.
Help, hope, and hype: Ethical dimensions ofneuroprosthetics
Authors: Clausen Jens , Fetz Eberhard , Donoghue John , Ushiba Junichi , Spörhase Ulrike , Chandler Jennifer , Birbaumer Niels , Soekadar Surjo R.
Published: July 2017

Accountability, responsibility, privacy, and security are key
Rapid cooling and cold storage in a silicic magma reservoir recorded in individual crystals
Authors: Rubin Allison E. , Cooper Kari M. , Till Christy B. , Kent Adam J. R. , Costa Fidel , Bose Maitrayee , Gravley Darren , Deering Chad , Cole Jim
Published: July 2017

Taupo Volcanic Zone magma spent more than 90% of its life deep and crystalline before rapid shallow accumulation and eruption.
Fatty acids in arbuscular mycorrhizal fungi are synthesized by the host plant
Authors: Luginbuehl Leonie H. , Menard Guillaume N. , Kurup Smita , Van Erp Harrie , Radhakrishnan Guru V. , Breakspear Andrew , Oldroyd Giles E. D. , Eastmond Peter J.
Published: July 2017

Lipid transfer provides symbiotic fungi associated with plant roots with a source of carbon.
A composite window into human history
Authors: Johannsen Niels N. , Larson Greger , Meltzer David J. , Vander Linden Marc
Published: July 2017

Better integration of ancient DNA studies with archaeology promises deeper insights
Iodide management in formamidinium-lead-halide–based perovskite layers for efficient solar cells
Authors: Yang Woon Seok , Park Byung-Wook , Jung Eui Hyuk , Jeon Nam Joong , Kim Young Chan , Lee Dong Uk , Shin Seong Sik , Seo Jangwon , Kim Eun Kyu , Noh Jun Hong , Seok Sang Il
Published: July 2017

Healing defects with triiodide ions

Deep-level defects in organic-inorganic perovskites decrease the performance of solar
cells through unproductive recombination of charge carriers. Yang
et
al.
show that introducing additional triiodide ions during the formation of
layers of formamidinium lead iodide, which also contain small amounts of methylammonium
lead bromide, suppresses the formation of deep-level defects. This process boosts the
certified efficiency of 1-cm
2
solar cells to almost 20%.

Science
, this issue p.
1376
Recurring and triggered slow-slip events near the trench at the Nankai Trough subduction megathrust
Authors: Araki Eiichiro , Saffer Demian M. , Kopf Achim J. , Wallace Laura M. , Kimura Toshinori , Machida Yuya , Ide Satoshi , Davis Earl ,   IODP Expedition 365 shipboard scientists, Toczko Sean , Carr Stephanie , Kinoshita Chihiro , Kobayashi Reiji , Rösner Alexander
Published: July 2017

Eight slow-slip events over 6 years accommodated up to 50% of the fault slip on the Nankai megathrust.
Unlikely allies
Natural Defense: Enlisting Bugs and Germs to Protect Our Food and Health
Emily Monosson
Island Press, 2017. 196 pp.
Authors: Schar Daniel
Published: July 2017

An environmental toxicologist advocates embracing microbes as partners in human and agricultural health
Human nature
Behave: The Biology of Humans at Our Best andWorst
Robert M. Sapolsky
Penguin Press, 2017. 796 pp.
Authors: de Waal Frans
Published: July 2017

A comprehensive tome explores the biology of our behavior
Early life stress confers lifelong stress susceptibility in mice via ventral tegmental area OTX2
Authors: Peña Catherine J. , Kronman Hope G. , Walker Deena M. , Cates Hannah M. , Bagot Rosemary C. , Purushothaman Immanuel , Issler Orna , Loh Yong-Hwee Eddie , Leong Tin , Kiraly Drew D. , Goodman Emma , Neve Rachael L. , Shen Li , Nestler Eric J.
Published: July 2017

An early window of stress susceptibility defines a mouse’s response to stress in adulthood.
A cocktail of poisons
Authors: Kerr Jeremy T.
Published: July 2017

The effects of sustained neonicotinoid exposure on bees depend on location, but
are usually negative
How latitude affects biotic interactions
Authors: Comita Liza S.
Published: July 2017

Impacts of trees on neighboring trees from the same species are stronger in the
tropics
Deciphering microglial diversity in Alzheimer's disease
Authors: Brown Guy C. , St George-Hyslop Peter H.
Published: July 2017

A subset of microglia appear primed to protect against AD neurodegeneration
Pittsburgh myth, Paris reality
Authors: Gallagher Patrick
Published: July 2017

When announcing his decision to withdraw the United States from the Paris Agreement, President Trump reminded the world that, “I was elected to represent the citizens of Pittsburgh, not Paris.” In doing so, he repeated a tired trope: that Pittsburgh is a rusty urban relic—a manufacturing city of steel that has fallen on hard times, held back by unfair global competition and onerous environmental regulation. But such a nostalgic version of Pittsburgh, and of many other communities across the country, is a myth. If the president truly wants to represent the interests of Americans, he would learn from the real histories of these regions and promote economic and environmental progress through research, education, and innovation.
Anniversaries for particle physics
Authors: Mangano Michelangelo
Published: July 2017

This month and next month mark two important anniversaries in the field of
particle physics—the 50th anniversary of the inauguration of Fermilab
(the Fermi National Accelerator Laboratory, just outside of Chicago, Illinois)
and the 5th anniversary of the Higgs boson discovery at CERN (the European
Organization for Nuclear Research, in Geneva, Switzerland). These two
institutions have been united in their commitment to elucidate the laws that
govern the physical universe. Their main achievements (the discovery of bottom
and top quarks at Fermilab, and of the W, Z, and Higgs bosons at CERN) reflect
how Fermilab and CERN, with other laboratories around the world, have joined
forces throughout these 50 years to prove right the “standard
model”—the theory that describes the fundamental components of
matter that we know of—or, to challenge it. Our quest to understand the
makeup and behavior of the world, to answer fundamental questions about the past
and future of our universe, and to explore the possible existence of an ultimate
“theory of everything” should continue to be a worldwide
effort.
Déjà vu for U.S. nuclear waste
Authors: Macfarlane Allison , Ewing Rod
Published: July 2017

With the arrival of the 115th U.S. Congress, the House of Representatives began
hearings on the Nuclear Waste Policy Amendments Act of 2017. The legislation
restarts Yucca Mountain as a repository for highly radioactive waste. In 1987,
Congress amended the Nuclear Waste Policy Act of 1982, selecting Yucca Mountain,
Nevada, as the only site to be studied, expecting the repository to open in
1998. It did not. Over the past 30 years, not much has changed. But going
forward—or not—with Yucca Mountain will not address the systemic
problems of the U.S. nuclear waste program, and this may well lead to continued
failure.
Association of perceived tinnitus with duration of hormone replacement therapy in Korean postmenopausal women: a cross-sectional study
Authors: Lee Seong-Su , Han Kyung-do , Joo Young-Hoon
Published: July 2017

Objective

The purpose of this study was to determine the relationship between hormone replacement therapy (HRT) and tinnitus in South Korea using data from the Korea National Health and Nutrition Examination Surveys (KNHANES) (2010–2012).

Study design

Cross-sectional analysis of a nationwide health survey.

Methods

KNHANES is a nationally representative cross-sectional survey of South Korea population. Only postmenopausal women aged 19–65 years were included in the study (n=2736). Auditory function was evaluated using pure-tone audiometric testing according to established KNHANES protocols. Subjects were questioned about their experience with tinnitus. Exogenous hormone-related factors included the starting age and duration of HRT.

Results

The overall prevalence of tinnitus was 22.2% among postmenopausal women. (1) Tinnitus severity was significantly higher in women using HRT (p=0.0024) and (2) significantly lower in women who breast fed their children (p=0.0386). (3) According to logistic regression models, the longer duration of HRT was significantly associated with increasing tinnitus (OR=1.323, 95% CI 1.007 to 1.737, p=0.0441).

Conclusion

A longer duration of HRT was associated with developing tinnitus in Korean postmenopausal women. Further experimental and epidemiological researches are needed to elucidate the causal relationship between HRT and tinnitus.
Translation, adaptation and measurement properties of an electronic version of the Danish Western Ontario Shoulder Instability Index (WOSI)
Authors: Eshoj Henrik , Bak Klaus , Blønd Lars , Juul-Kristensen Birgit
Published: July 2017

Objectives

To translate and adapt the Western Ontario Shoulder Instability (WOSI) questionnaire into Danish and, to evaluate measurement properties of an electronic Danish WOSI version.

Methods

The Swedish WOSI version was used for translation and adaptation into Danish followed by examination of test-retest reproducibility (14-day interval) besides concurrent and construct validity. Concurrent validity was examined by comparing WOSI in paper version with an electronic version, whereas construct validity was examined by comparing WOSI with Numeric Pain Rating Scale (NPRS) and the Oxford Shoulder Score (OSS). Reproducibility was evaluated with Intraclass correlations (ICC), Standard Error of Measurement (SEM), minimal detectable change (MDC) and limits of agreement (LOA). Validity was evaluated with Pearson’s (r)and Concordance Correlation Coefficients (CCC).

Results

41 subjects (median age 34, range 18–57) were included in the analysis of reproducibility. An ICC of 0.97 (95% CI 0.95 to 0.99) for the total WOSI score was found. SEM was 100.1, resulting in an MDC of 277.5 and LOAs within the range of -246.4 and 308.6. 25 subjects (median age 34, range 18–72) were included in the analysis of concurrent validity obtaining a CCC of 0.96 (95% CI 0.91 to 0.98). Construct validity was investigated in 62 subjects (median age 31, range 18–72) obtaining correlations of 0.83 (95% CI 0.68 to 0.97) (NPRS) and 0.79 (95% CI 0.62 to 0.94) (OSS).

Conclusions

An electronic Danish version of WOSI presented excellent test-retest reproducibility and acceptable measurement errors. Also, concurrent validity between paper and electronic version was highly satisfactory as was the construct validity. Surprisingly, though, the NPRS correlated more with WOSI than OSS.
Description of the rates, trends and surgical burden associated with revision for prosthetic joint infection following primary and revision knee replacements in England and Wales: an analysis of the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man
Authors: Lenguerrand Erik , Whitehouse Michael R , Beswick Andrew D , Toms Andrew D , Porter Martyn L , Blom Ashley W
Published: July 2017

Objectives

To describe the prevalence rates of revision surgery for the treatment of prosthetic joint infection (PJI) for patients undergoing knee replacement, their time trends, the cumulative incidence function of revision for PJI and estimate the burden of PJI at health service level.

Design

We analysed revision knee replacements performed due to a diagnosis of PJI and the linked index procedures recorded in the National Joint Registry from 2003 to 2014 for England and Wales. The cohort analysed consisted of 679 010 index primary knee replacements, 33 920 index revision knee replacements and 8247 revision total knee replacements performed due to a diagnosis of PJI. The prevalence rates, their time trends investigated by time from index surgery to revision for PJI, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression.

Results

The incidence of revision total knee replacement due to PJI at 2 years was 3.2/1000 following primary and 14.4/1000 following revision knee replacement, respectively. The prevalence of revision due to PJI in the 3 months following primary knee replacement has risen by 2.5-fold (95% CI 1.2 to 5.3) from 2005 to 2013 and 7.5-fold (95% CI 1.0 to 56.1) following revision knee replacement. Over 1000 procedures per year are performed as a consequence of knee PJI, an increase of 2.8 from 2005 to 2013. Overall, 75% of revisions were two-stage with an increase in use of single-stage from 7.9% in 2005 to 18.8% in 2014.

Conclusions

Although the risk of revision due to PJI following knee replacement is low, it is rising, and coupled with the established and further predicted increased incidence of both primary and revision knee replacements, this represents an increasing and substantial treatment burden for orthopaedic service delivery in England and Wales. This has implications for future service design and the funding of individual and specialist centres.
Words do matter: a systematic review on how different terminology for the same condition influences management preferences
Authors: Nickel Brooke , Barratt Alexandra , Copp Tessa , Moynihan Ray , McCaffery Kirsten
Published: July 2017

Objectives

Changing terminology for low-risk, screen-detected conditions has now been recommended by several expert groups in order to prevent overdiagnosis and reduce the associated harms of overtreatment. However, the effect of terminology on patients’ preferences for management is not well understood. This review aims to synthesise existing studies on terminology and its impact on management decision making.

Design

Systematic review.

Methods

Studies were included that compared two or more terminologies to describe the same condition and measured the effect on treatment or management preferences and/or choices. Studies were identified via database searches from inception to April 2017, and from reference lists. Two authors evaluated the eligibility of studies with verification from the study team, extracted and crosschecked data, and assessed the risk of bias of included studies.

Results

Of the 1399 titles identified, seven studies, all of which included hypothetical scenarios, met the inclusion criteria. Six studies were quantitative and one was qualitative. Six of the studies were of high quality. Studies covered a diverse range of conditions: ductal carcinoma in situ (3), gastro-oesophageal reflux disease (1), conjunctivitis (1), polycystic ovary syndrome (1) and a bony fracture (1). The terminologies compared in each study varied based on the condition assessed. Based on a narrative synthesis of the data, when a more medicalised or precise term was used to describe the condition, it generally resulted in a shift in preference towards more invasive managements, and/or higher ratings of anxiety and perceived severity of the condition.

Conclusions

Different terminology given for the same condition influenced management preferences and psychological outcomes in a consistent pattern in these studies. Changing the terminology may be one strategy to reduce patient preferences for aggressive management responses to low-risk conditions.

Trial registration number

PROSPERO: CRD42016035643.
Performance of highly sensitive cardiac troponin T assay to detect ischaemia at PET-CT in low-risk patients with acute coronary syndrome: a prospective observational study
Authors: Morawiec Beata , Fournier Stephane , Tapponnier Maxime , Prior John O , Monney Pierre , Dunet Vincent , Lauriers Nathalie , Recordon Frederique , Trana Catalina , Iglesias Juan-Fernando , Kawecki Damian , Boulat Olivier , Bardy Daniel , Lamsidri Sabine , Eeckhout Eric , Hugli Olivier , Muller Olivier
Published: July 2017

Background

Highly sensitive troponin T (hs-TnT) assay has improved clinical decision-making for patients admitted with chest pain. However, this assay’s performance in detecting myocardial ischaemia in a lowrisk population has been poorly documented.

Purpose

To assess hs-TnT assay’s performance to detect myocardial ischaemia at positron emission tomography/CT (PET-CT) in low-risk patients admitted with chest pain.

Methods

Patients admitted for chest pain with a nonconclusive ECG and negative standard cardiac troponin T results at admission and after 6 hours were prospectively enrolled. Their hs-TnT samples were at T0, T2 and T6. Physicians were blinded to hs-TnT results. All patients underwent a PET-CT at rest and during adenosine-induced stress. All patients with a positive PET-CT result underwent a coronary angiography.

Results

Forty-eight patients were included. Six had ischaemia at PET-CT. All of them had ≥1 significant stenosis at coronary angiography. Areas under the curve (95% CI) for predicting significant ischaemia at PET-CT using hs-TnT were 0.764 (0.515 to 1.000) at T0, 0.812(0.616 to 1.000) at T2 and 0.813(0.638 to 0.989) at T6. The receiver operating characteristicbased optimal cut-off value for hs-TnT at T0, T2 and T6 needed to exclude significant ischaemia at PET-CT was <4 ng/L. Using this value, sensitivity, specificity, positive and negative predictive values of hs-TnT to predict significant ischaemia were 83%/38%/16%/94% at T0, 100%/40%/19%/100% at T2 and 100%/43%/20%/100% at T6, respectively.

Conclusions

Our findings suggest that in low-risk patients, using the hs-TnT assay with a cut-off value of 4 ng/L demonstrates excellent negative predictive value to exclude myocardial ischaemia detection at PET-CT, at the expense of weak specificity and positive predictive value.

Trial registration number

ClinicalTrials.gov Identifier:NCT01374607.
Development in the number of clinical trial applications in Western Europe from 2007 to 2015: retrospective study of data from national competent authorities
Authors: Dombernowsky Tilde , Hædersdal Merete , Lassen Ulrik , Thomsen Simon Francis
Published: July 2017

Objective

To investigate the development in the number of applications for authorisation of clinical trials of medicines (CTAs) submitted annually to national competent authorities in 10 Western European member states of the European Union from 2007 to 2015.

Design

Registry study.

Setting

Data from national competent authorities.

Participants

Germany, Italy, Spain, France, the UK, Belgium, the Netherlands, Austria, Denmark and Sweden. Inclusion criteria were Western European member states of the European Union, receiving more than 200 CTAs per year.

Outcome measures

Summarised number of CTAs and distribution of CTAs by type of sponsor (commercial or non-commercial) and trial phase (I–IV). Average annual growth rates (AAGRs) based on linear regressions. Data were evaluated 2007–2011 and 2012–2015 to compare findings with the European Commission’s statement of a 25% decrease in CTAs in the EU from 2007 to 2011.

Results

From 2007 to 2011, the summarised number of CTAs decreased significantly (AAGR −3.9% (p=0.02)), primarily due to a decrease in commercially sponsored CTAs. From 2012 to 2015, the change was insignificant (AAGR 2.6% (p=0.27)), however with a 10% increase from 2014 to 2015 after stagnation from 2012 to 2014. Overall, the number of CTAs and distribution by type of sponsor varied considerably between countries. No distinct trends were observed when evaluating CTAs by type of trial phase.

Conclusions

This study found a significant decrease in the number of CTAs in Western Europe from 2007 to 2011 (AAGR −3.9%). This development is possibly attributable to several factors such as the European Clinical Trials Directive, national and local political decisions, and a potential global shift in clinical trial activity. From 2014 to 2015, the number of CTAs increased markedly (10%). However, it is yet too soon to determine if this constitutes a transient fluctuation or a new trend.
Ethnic differences in current smoking and former smoking in the Netherlands and the contribution of socioeconomic factors: a cross-sectional analysis of the HELIUS study
Authors: Brathwaite Rachel , Smeeth Liam , Addo Juliet , Kunst Anton E , Peters Ron J G , Snijder Marieke B , Derks Eske M , Agyemang Charles
Published: July 2017

Objectives

Data exploring how much of the ethnic differences in smoking prevalence and former smoking are explained by socioeconomic status (SES) are lacking. We therefore assessed ethnic differences in smoking prevalence and former smoking and the contribution of both educational level and occupational-related SES to the observed ethnic differences in smoking behaviour.

Methods

Data of 22 929 participants (aged 18–70 years) from the multiethnic cross-sectional Healthy Life in an Urban Setting study in the Netherlands were analysed. Poisson regression models with a robust variance were used to estimate prevalence ratios.

Results

Compared with the Dutch, after adjustment for age and marital status, smoking prevalence was higher in men of Turkish (prevalence ratio 1.69, 95% CI 1.54 to 1.86), African Surinamese (1.55, 95% CI 1.41 to 1.69) and South-Asian Surinamese origin (1.53, 95% CI 1.40 to 1.68), whereas among women, smoking prevalence was higher in Turkish, similar in African Surinamese but lower in all other ethnic origin groups. All ethnic minority groups, except Ghanaians, had a significantly lower smoking cessation prevalence than the Dutch. Socioeconomic gradients in smoking (higher prevalence among those lower educated and with lower level employment) were observed in all groups except Ghanaian women (a higher prevalence was observed in the higher educated). Ethnic differences in smoking prevalence and former smoking are largely, but not completely, explained by socioeconomic factors.

Conclusions

Our findings imply that antismoking policies designed to target smoking within the lower socioeconomic groups of ethnic minority populations may substantially reduce ethnic inequalities in smoking particularly among men and that certain groups may benefit from targeted smoking cessation interventions.
Leisure-time physical activity and circulating 25-hydroxyvitamin D levels in cancer survivors: a cross-sectional analysis using data from the US National Health and Nutrition Examination Survey
Authors: Yang Lin , Toriola Adetunji T
Published: July 2017

Objectives

Circulating 25-hydroxyvitamin D (25-OHD) is associated with improved cancer prognosis in some studies, yet it may be a surrogate marker for physical activity. We investigated the associations of leisure-time physical activity (LTPA) with circulating 25-OHD levels in cancer survivors, and determined whether associations differ by indoor and outdoor activity.

Design

Cross-sectional study.

Setting

The US National Health and Nutrition Examination Survey (NHANES).

Participants

Cancer survivors with available data on demographic information, measures of adiposity, smoking history, self-reported LTPA and circulating 25-OHD levels in five waves of NHANES (2001–2010).

Main outcomes measures

Circulating 25-OHD levels.

Results

Multivariable linear regression and logistic regression models were used to evaluate the associations of self-reported LTPA with 25-OHD, adjusting for potential confounders. Due to the differences in LTPA measure, the analyses were conducted separately for 2001–2006 and 2007–2010 data. We further estimated associations by indoor and outdoor activity in the 2001–2006 data. There were 1530 cancer survivors (mean age=60.5 years, mean body mass index=28.6 kg/m2). The prevalent cancer sites were breast (19.3%), prostate (18.8%), cervix (10.4%) and colon (8.6%). Compared with inactive cancer survivors, being physically active was associated with higher circulating 25-OHD levels (8.07 nmol/L, 95% CI 4.63 to 11.52) for 2001–2006 data. In the mutually adjusted model, higher outdoor activity (5.83 nmol/L, 95% CI 1.64 to 10.01), but not indoor activity (2.93 nmol/L, 95% CI −1.80 to 7.66), was associated with statistically significantly higher 25-OHD levels. The interaction between indoor and outdoor activities was, however, not significant (p=0.29). The only statistically significant association seen in the 2007–2010 data was among obese cancer survivors.

Conclusion

Physical activity, particularly outdoor activity, is associated with higher 25-OHD levels in cancer survivors. In view of the possible beneficial effects of vitamin D on cancer prognosis, engaging in outdoor physical activity could provide clinically meaningful increases in 25-OHD levels among cancer survivors.
Prevalence and antibiotic resistance ofMycoplasma genitaliumamong STI clinic attendees in Western Canada: a cross-sectional analysis
Authors: Gratrix Jennifer , Plitt Sabrina , Turnbull LeeAnn , Smyczek Petra , Brandley Judith , Scarrott Ron , Naidu Prenilla , Parker Penny , Blore Brenda , Bull Amy , Shokoples Sandy , Bertholet Lindsay , Martin Irene , Chernesky Max , Read Ron , Singh Ameeta
Published: July 2017

Objectives

To determine the prevalence and correlates ofMycoplasmagenitalium(MG) infection among men and women, determine the prevalence of gene mutations conferring resistance and compare test performance of female specimen types.

Methods

A cross-sectional study was conducted on specimens collected for gonorrhoea (NG,Neisseria gonorrhoeae) and chlamydia (CT,Chlamydia trachomatis) among male and female Alberta STI clinic attendees using theM. genitaliumtranscription-mediated amplification-research use only test. Positive specimens were sequenced for 23SrRNA,parCandgyrAgenes. Gender-stratified analysis compared test results using χ2or Fisher’s exact test, Mann-Whitney U test and logistic regression. Female endocervical and urine specimens were compared.

Results

A total of 2254 individuals were tested; 53.8% (n=1212) were male. Male prevalence of MG was 5.3%; CT was 5.9% and NG was 1.8%. Correlates of male infection were a non-gonococcal urethritis diagnosis and NG coinfection. MG prevalence for women was 7.2%; CT was 5.8% and NG was 1.8%. Correlates of female infection were younger age, Indigenous/Other ethnicity and CT/NG coinfection. Nearly two-thirds of eligible specimens had mutations associated with macrolide resistance and 12.2% of specimens had aparCmutation signifying possible moxifloxacin resistance. There was high concordance (98.1%) of results between urine and endocervical swabs.

Conclusions

The high prevalence of MG relative to CT and NG supports the incorporation of MG testing into routine sexually transmissible infection screening. The high rate of resistance to macrolides and moxifloxacin raises concerns about treatment options. The good concordance of results between urine and endocervical swabs supports the use of female urine specimens for testing.
The involvement of physician assistants in inpatient care in hospitals in the Netherlands: a cost-effectiveness analysis
Authors: Timmermans Marijke J C , van den Brink Geert T , van Vught Anneke J A H , Adang Eddy , van Berlo Charles L H , Boxtel Kim van , Braunius Weibel W , Janssen Loes , Venema Alyssa , van den Wildenberg Frits J , Wensing Michel , Laurant Miranda G H
Published: July 2017

Objective

To investigate the cost-effectiveness of substitution of inpatient care from medical doctors (MDs) to physician assistants (PAs).

Design

Cost-effectiveness analysis embedded within a multicentre, matched-controlled study. The traditional model in which only MDs are employed for inpatient care (MD model) was compared with a mixed model in which, besides MDs, PAs are also employed (PA/MD model).

Setting

34 hospital wards across the Netherlands.

Participants

2292 patients were followed from admission until 1 month after discharge. Patients receiving daycare, terminally ill patients and children were excluded.

Primary and secondary outcome measures

All direct healthcare costs from day of admission until 1 month after discharge. Health outcome concerned quality-adjusted life years (QALYs), which was measured with the EuroQol five dimensions questionnaire (EQ-5D).

Results

We found no significant difference for QALY gain (+0.02, 95% CI −0.01 to 0.05) when comparing the PA/MD model with the MD model. Total costs per patient did not significantly differ between the groups (+€568, 95% CI −€254 to €1391, p=0.175). Regarding the costs per item, a difference of €309 per patient (95% CI €29 to €588, p=0.030) was found in favour of the MD model regarding length of stay. Personnel costs per patient for the provider who is primarily responsible for medical care on the ward were lower on the wards in the PA/MD model (−€11, 95% CI −€16 to −€6, p<0.01).

Conclusions

This study suggests that the cost-effectiveness on wards managed by PAs, in collaboration with MDs, is similar to the care on wards with traditional house staffing. The involvement of PAs may reduce personnel costs, but not overall healthcare costs.

Trial registration number

NCT01835444.
Periodontitis: a global disease and the primary care provider’s role
Authors: Gross Andrew Jacob , Paskett Keith Trevor , Cheever Val Joseph , Lipsky Martin S
Published: July 2017

Individuals who regularly visit a primary care provider (PCP) may not see a dentist, creating opportunities for PCPs to improve oral health. However, a lack of expertise among PCPs may limit their impact to improve public oral health. Using a non-systematic literature review, this article summarises the relevant literature about periodontitis. Periodontitis affects 10% to –15% of the world’s population. Caused by bacterial inflammation in gingival pockets, periodontal disease can destroy tissues surrounding the teeth. Factors linked to periodontal disease include diabetes, atherosclerosis and smoking. Good oral hygiene is important for both prevention and treatment. Mechanical removal of gingival irritants by scaling and root planing combined with adjunctive antimicrobial therapy are first-line treatment options. Surgery is indicated when healthy levels of gingival tissue are not attained from first-line treatments. By understanding the fundamentals of periodontitis the primary care provider can educate patients, promote healthy oral health behaviours and appropriately refer patients with signs and symptoms of periodontal disease.
A 12-week low-carbohydrate, high-fat diet improves metabolic health outcomes over a control diet in a randomised controlled trial with overweight defence force personnel
Authors: Zinn Caryn , McPhee Julia , Harris Nigel , Williden Micalla , Prendergast Kate , Schofield Grant
Published: July 2017

Overweight, obesity, and poor health is becoming a global concern for defence force personnel. Conventional nutrition guidelines are being questioned for their efficacy in achieving optimal body composition and long-term health. This study compared the effects of a 12-week low-carbohydrate, high-fat diet with a conventional, high-carbohydrate, low-fat diet on weight reduction and metabolic health outcomes in at-risk New Zealand Defence Force personnel. In this randomised controlled trial, 41 overweight personnel were assigned to intervention and control groups. Weight, waist circumference, fasting lipids, and glycaemic control were assessed at baseline and at 12 weeks. Within-group change scores were analysed using the t statistic and interpreted using a p < 0.05 level of statistical significance. Between-group mean differences and confidence intervals were analysed using effect sizes and magnitude-based inferences. Twenty-six participants completed the trial (14 intervention, 12 control). Both groups showed statistically significant weight and waist circumference reductions; the intervention group significantly reduced triglycerides and serum glucose and significantly increased high-density lipoprotein cholesterol (HDLc). Relative to control, the intervention group showed small, possibly to likely beneficial effects for weight, triglycerides, glucose, insulin, and homeostasis model assessment of insulin resistance; moderate, likely beneficial effects for HDL cholesterol, triglyceride:HDLc ratio and HbA1c; and a small, likely harmful effect for low-density lipoprotein cholesterol. This dietary approach shows promise for short-term weight loss and improved metabolic health outcomes conditions compared with mainstream recommendations. It should be offered to defence force personnel at least as a viable alternative means to manage their weight and health.