bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel dual-molality densitometer for gauging in annular two phase flows using radial basis function
Authors: Roshani G. H. , Nazemi E.
Published: April 2018

This study presents a novel method for determining the density of liquid phase in annular regime of two phase flows by utilizing dual modality densitometry technique and artificial neural network (ANN) model of radial basis function (RBF). The detection system is comprised of one 137Cs radioactive source, one 1 inch sodium iodide (NaI) scintillation detector for registering transmitted photons and one 1 inch NaI detector for registering scattered photons. An experimental setup was designed in order to provide the required data for testing and training the ANN. Registered counts in two detectors were utilized as the inputs of ANN and density of liquid phase was used as the output of ANN. The results show that the proposed approach could be successfully applied for predicting the density of liquid phase in annular regime of gas-liquid two phase flows. The liquid phase density was predicted with root mean square error (RMSE) of less than 0.0155 without a prior knowledge of the void fraction percentage in annular regime.
Abnormal control rod withdrawal analysis for innovative research reactor using PARET-ANL codes
Authors: Hastuti E. P. , Tukiran S. , Widodo S. , Sudarmono
Published: April 2018

Innovative Research Reactor 50 MW (RRI-50) is a conceptual design of an Indonesia's high-power innovative research reactor, which is designed to produce a maximum neutron flux as high as 1.0 × 1015 n/cm2 s and thermal neutron flux of 5.0 × 1014 n/cm2 s. In this study, the design basis accident slow reactivity insertion is carried out. Reactivity insertion accident (RIA) caused by the inadvertent withdrawal of all fuel rod at normal rate is simulated by using PARET-ANL transient code. In the simulation accident is assumed to occur when the reactor is in operation at high power and at low power level. During transient, the fuel rods are assumed to be in the most effective positions with insertion rate of 0.049 $/s. This reactivity worth will give effect only if the fuel rod interlock system is failed to function properly and the operator action does not follow the standard operation procedure. The analysis results show that the reactor experiences scram when it reaches its protected power at high power level of 110 % (55 MW) at period of 5 s and at low power level of 3 MW at period of 120 s, and there is sufficient safety margin for the anticipated RIA caused by reactivity feedback.
Improving CANDU performance by using uranium – thorium mixed oxide fuel
Authors: Neacşa R. , Rizoiu A. , Priscearu I.
Published: April 2018

CANDU reactor flexibility in using advanced fuel options allowed the continuous improvement of its performances. Both economic benefits and better operational safety are expected from thorium-based fuel alternatives. This paper addresses the use of uranium – thorium mixed oxide in 37- and 43-element CANDU fuel bundles, in the aim of obtaining better economic and safety performances. Thorium is expected to partially replace uranium in the fuel, the expected Th/U ratio being 1.5 ÷ 2.333. These bundles are meant to be loaded in every channel of the CANDU core, in a homogenous “once-through Thorium” (OTT) core. The low-enriched uranium (LEU) with 5 ÷10 wt% U-235 is a suitable fissile driver material for thorium in CANDU, allowing the chain reaction to be initiated throughout the core. Cell calculations were performed using the transport codes DRAGON and WIMS, as well as the associated nuclear data library, in order to estimate the key fuel performance parameters: maximum burnup, power peaking factors, fissile utilization, void reactivity, Doppler effect and proliferation resistance.
Design and construction of toroidal field coil for Taban device
Authors: Mirzaei H. R. , Amrollahi R.
Published: April 2018

The Taban device has a circular cross section chamber, which is under construction in Amirkabir University of Technology. It has been designed to work in two modes: Tokamak and simple magnetized device. The main part of the Taban device design was the Toroidal Field coils. In this paper, a refined design of the Toroidal Field coil system for the Taban device was presented. Toroidal field coil consist of 16 circular shape coils connected in series, with 30 turns each coils, its material is cooper with 6 mm2 area (16 AWG) that can carry 3 kA transient current. In tokamak mode, that makes the magnetic field of 0.7 T at the plasma center. The total stored energy is 130 kJ, and the power supply used in this system is a capacitor bank with capacity of C = 2.6 mF and Vmax = 10 kV. In simple magnetized device mode, magnetic field is 0.1 T at high field side. The stored energy is 20 kj and the power supply used in this system is capacitor bank with capacity of C = 40 mF and Vmax = 1 kV.
Thermal hydraulic assessment of a new design of PWR fuel assembly
Authors: Elnour Asmaa G. Abo , Mohamed Nader M. A.
Published: April 2018

The recycling of the spent fuel of nuclear reactors is the important aspects in the fuel cycle technology. One of the recycling of the spent fuel is reuse of spent PWR (pressurized water reactor) fuel in CANDU reactor after re-fabricated into CANDU (CANda deuterium uranium) fuel bundles; this technology called Direct Use of Spent PWR Fuel In CANDU Reactor (DUPIC). This technology was modified however; it introduced a new design for the PWR fuel assembly. The new fuel can be transferred directly to CANDU reactors without processing, only after a certain cooling time. In this study the evaluation from thermal hydraulic point of view is done. A Westinghouse PWR fuel assembly was selected as a reference. Thermal hydraulic simulation for reference and new design fuel occurred by using RELAP5 (Reactor Excursion and Leak Analysis Program) code, then comparing the both results. The hottest rod was considered a worst condition in the reactor so the model simulated it rather than whole core. The new design achieves a good results comparing with a reference one.
Calculation of liquid waste discharge limits for routine discharge of Tehran research reactor
Authors: Adelikhah M. E. , Ahangari R. , Noori O.
Published: April 2018

One of the most important technical documents for obtaining of a reactor license (site selection, design, construction and operation license) from IINRA is public dose assessment and calculation of discharge limits into the environment. Presence of population centers and aquifers adjacent of nuclear installations is a crucial rule in public dose assessment and determination of liquid release limits into the environment. In this paper, liquid waste of TRR regards as liquid released in sewage system. The migration of radionuclides released to well through the ingestion of radionuclides via drinking water and human food-chain, inhalation of radionuclides and external irradiation from radionuclides in soil and water was modeled using the AMBER software. Then, amount of liquid released to environment with different amount of distribution coefficient, as an important effective parameter in simulation, is determined. The calculation of discharge limits shows that the liquid radioactive waste is lower than the values given into the Environmental Assessment for Tehran Research Reactor report. So the received dose doesn't exceed the dose limit of 10 μSvyr−1 for members of the public which is approved by INRA.
Data collection assessment for the human performance analysis in nuclear installations
Authors: Farcasiu M. , Nitoi M. , Apostol M. , Constantinescu C.
Published: April 2018

The purpose of this paper is to provide a good knowledge and understanding on the main factors influencing human performance in complex systems operation. Identification and establishment of the necessary data for human factor performance analysis in a socio-technical context based on the analysis of HRA methods are performed. An evaluation of the techniques used for collecting and characterization of necessary data for HRA (observation, questionnaire, interview, task analysis, change analysis, simulator, expert judgement) is achieved also. The necessary data to perform HRA for the TRIGA reactor operation, for activities of the post-irradiation examination laboratory and activities of the radioactive waste plant treatment from RATEN ICN Pitesti were obtained. Recommendations on how to obtain data and knowledge related to development of methodical framework of HRA data collection, characterization and evaluation are also presented in this paper.
Porosity evolution study in irradiated UO2 fuel based on fuel matrix swelling
Authors: Roostaii B. , Kazeminejad H. , Khakshournia S.
Published: April 2018

The volume porosity of irradiated UO2 fuel in the form of a correlation is developed which includes two individual parts as the pore and swelling porosity in terms of the local density and fractional matrix swelling. Based on a low temperature swelling model for UO2 fuel, the matrix swelling terms are calculated and the evolution of porosity up to burn-up levels of 120 MWd/KgU is presented. It is seen that for high burn-up PWR fuel pellet rim, the dominant contribution to total porosity comes from pores generated due to Xe depletion in the ceramic matrix while the nearly constant swelling porosity makes a small contribution to the total porosity. The porosity evolution is also validated by comparing against experimental data and a fairly good agreement was found.
Computation of gamma radioactivity of natural rocks in the vicinity of Antalya province and its effect on health
Authors: Unal S. , Yalcin M. G. , Ocak S. , Yalcin R. , Ozmen S. F.
Published: April 2018

The aim of this study is to determine uranium (238U), potassium (40K) and thorium (232Th) in the radioactive elements by measuring the natural rocks in the vicinity of Antalya province by using High-purity Germanium (HPGe) Detector with gamma spectrometry 69. At the end of the measurements, total absorbed dose rates of the rock samples have been found to be within the normal range of values between 3.10 nGy/h and 117.35 nGy/h. While the minimum value of Raeq has been determined to be 6.36 Bq/kg at sample S8, the maximum value has been determined as 250.15 Bq/kg at sample S4. All of the values obtained at the end of the study have been determined to be lower than the maximum Raeq value (370 Bq/kg) and the limit values for industrial products which ranges between 370 – 740 Bq/kg. ARa, ATh and AK; 232Th, 40K and 226Ra of radionuclides are the activity concentrations in terms of Bq/kg. The hex value should be less than 1. The value is based on the upper limit of Raeq (370 Bq/kg). All of the results obtained are less than the limit value of 1.
Pollinator Decline – An Ecological Calamity in the Making?
Authors: Rhodes Christopher J.
Published: April 2018

Since pollination by insects is vitally important for much of global crop production, and to provide pollination services more widely throughout the planetary ecosystems, the prospect of an imminent ‘pollination crisis’, due to a die-off of flying insects, is most disquieting, to say the least. Indeed, the term ‘ecological Armageddon’ has been used in the media. However, to know whether or not a wholesale decline in flying pollinators (including non-bee species) is occurring across the world is very difficult, due to an insufficiency of geographically widespread and long-term data. Bees, as the best documented species, can be seen to be suffering from chronic exposure to a range of stressors, which include: a loss of abundance and diversity of flowers, and a decline in suitable habitat for them to build nests; long-term exposure to agrochemicals, including pesticides such as neonicotinoids; and infection by parasites and pathogens, many inadvertently spread by the actions of humans. It is likely that climate change may impact further on particular pollinators, for example bumble bees, which are cool-climate specialists. Moreover, the co-operative element of various different stress factors should be noted; thus, for example, exposure to pesticides is known to diminish detoxification mechanisms and also immune responses, hence lowering the resistance of bees to parasitic infections. It is further conspicuous that for those wild non-bee insects – principally moths and butterflies – where data are available, the picture is also one of significant population losses. Alarmingly, a recent study in Germany indicated that a decline in the biomass of flying insects had occurred by 76% in less than three decades, as sampled in nature reserves across the country. Accordingly, to fully answer the question posed in the title of this article ‘pollinator decline - an ecological calamity in the making?’ will require many more detailed, more geographically encompassing, more species-inclusive, and longer-term studies, but the available evidence points to a clear ‘probably’, and the precautionary principle would suggest this is not a prospect we can afford to ignore.
The Wardian Case: Environmental Histories of a Box for Moving Plant
Authors: Keogh Luke
Published: April 2018

The Wardian case was a simple box that had major ecological impacts. It was invented in 1829 and allowed for the successful shipping of live plants between many countries and continents. In the nineteenth and early twentieth century, humans using Wardian cases facilitated major plant migrations across the globe. As a result humans have overtaken earth processes as the largest mover of vascular plants on the planet. Boxes and cases have largely been neglected as important movers of species and ecologies; with a focus on the Wardian case this essay offers a unique contribution to the field of environmental history. It also positions the importance of the case in contemporary discussions about the movement of plants in the Anthropocene.
Vulnerable Normality: Popular Neuroimaging and the Discursive Logic of the (Dis)able(d) Brain
Authors: Hansson Kristofer , Suneson Ellen
Published: April 2018

The aim of this article is to analyse popular neuroimaging of (dis)able(d) brains as a cultural phenomenon, as well as to explore how there has been, during the last decades, a subtle but important change in the way “normal” brains are depicted in popular science. Popular neuroimaging is introduced and used as an empirical basis to analyse what Fiona Kumari Campbell sees as a critique against ableism. The empirical material consists of two British popular science documentaries (both produced by the BBC) on the topic of the brain: Human Brain (1983), and Brain Story (2004). The article argues that the position of normality and able-bodiedness has changed as the development of brain scanning techniques has emerged. In particular, there seems to have been a change in how the brain is visualized and talked about. New frameworks for understanding normality, disability and vulnerability have appeared. Furthermore, we claim that this shift needs to be studied from a theoretical perspective that analyses the discursive logic of the (dis)able(d) brain where an indistinctness transpires and creates a form of vulnerable normality.
Visualising the Hypnotised Brain: Hysteria Research from Charcot to Functional Brain Scans
Authors: Muhr Paula
Published: April 2018

Contrary to the widely held belief in the humanities that hysteria no longer exists, this article shows that the advent of new brain imaging technologies has reignited scientific research into this age-old disorder, once again linking it to hypnosis. Even though humanities scholarship to date has paid no attention to it, image-based research of hysteria via hypnosis has been hailed in specialist circles for holding the potential to finally unravel the mystery of this elusive disorder. Following a succinct overview of how hypnosis was used in the nineteenth century hysteria research, the article details how the relationship between hysteria and hypnosis is currently renegotiated in the context of brain imaging studies. It shows that the current research has so far failed to deliver on its promise of uncovering the link between hysteria and hypnosis. It further argues that despite huge technological advances in imaging technologies, contemporary researchers grapple with conceptual problems comparable to those that plagued their nineteenth century predecessors.
A New Discharge Pattern for the Characterization and Identification of Insulation Defects in GIS
Authors: Yao Rui , Hui Meng , Li Jun , Bai Lin , Wu Qisheng
Published: April 2018

Identification of insulation defects in gas insulated metal-enclosed switchgear (GIS) is important for partial discharge (PD) evaluation. This article proposes a polar coordinate pattern approach to characterize the different kinds of defect types. These defect types include floating electrodes, a fixed protrusion on the enclosure, surface contamination on the spacer, metallic prominence on the high voltage electrode, a void in the insulator, and free metal particles on the enclosure. First, the physical models for the insulation defects in the established GIS model are designed. Second, the phase resolved pulse sequence (PRPS) data sets are obtained using ultra-high frequency (UHF) measurement. Then, the polar coordinate patterns are proposed to characterize the defects. Nine discharge parameters combined with the parameters based on quadrant statistical theory constitute the input feature vector to identify the PD types. The experimental results show that these new parameters could produce a clear, quantitative description of the characteristics of the defect types and could be used to distinguish between the different kinds of defect types.
Sustainable Blended Cements—Influences of Packing Density on Cement Paste Chemical Efficiency
Authors: Knop Yaniv , Peled Alva
Published: April 2018

This paper addresses the development of blended cements with reduced clinker amount by partial replacement of the clinker with more environmentally-friendly material (e.g., limestone powders). This development can lead to more sustainable cements with reduced greenhouse gas emission and energy consumption during their production. The reduced clicker content was based on improved particle packing density and surface area of the cement powder by using three different limestone particle diameters: smaller (7 µm, 3 µm) or larger (70 µm, 53 µm) than the clinker particles, or having a similar size (23 µm). The effects of the different limestone particle sizes on the chemical reactivity of the blended cement were studied by X-ray diffraction (XRD), thermogravimetry and differential thermogravimetry (TG/DTG), loss on ignition (LOI), isothermal calorimetry, and the water demand for reaching normal consistency. It was found that by blending the original cement with limestone, the hydration process and the reactivity of the limestone itself were increased by the increased surface area of the limestone particles. However, the carbonation reaction was decreased with the increased packing density of the blended cement with limestone, having various sizes.
Genetic Variation of the Human ACE and ACTN3 Genes and Their Association With Functional Muscle Properties in Lithuanian Elite Athletes
Authors: Ginevičienė Valentina , Pranculis Aidas , Jakaitienė Audronė , Milašius Kazys , Kučinskas Vaidutis
Published: April 2018

Background and Objective. Based on the results of many studies, the angiotensinconverting enzyme (ACE) and the α-actinin-3 (ACTN3) genes are considered strong candidate genes associated with human physical performance. On the other hand, the data regarding the association of the ACE I/D and ACTN3 R/X polymorphisms with human physical performance in different populations have been conflicting. The objective of our research was to evaluate the significance of these genetic variants on muscle performance phenotype in Lithuanian athletes. Material and Methods. The study involved 193 Lithuanian elite athletes and 250 controls from the general Lithuanian population. Genotyping was performed by polymerase chain reaction and/ or restriction fragment length polymorphism analysis. Anthropometric measurements and muscle strength (grip strength and vertical jump) were measured. Results. It was determined that ACE I/I and I/D genotypes were more frequent in the athlete group compared with the general Lithuanian population. The results of grip strength and vertical jum p were better in the athletes with the ACE I/I and ACTN3 X/X genotype compared with the athletes with ACE D/D and ACTN3 R/R, respectively. Conclusions. The ACE I and ACTN3 X alleles determine speed and power for Lithuanian athletes. In line with other researchers, it can be confirmed that the absence of a functional ACTN3 in fast-twitch muscle fibers is compensated. Lithuanian athletes who are carriers of the ACE I/I and I/D as well as ACTN3 X/X and R/X genotypes have the potential to achieve better results in power-requiring sports; therefore, the analyzed polymorphisms of these genes might be used as the criteria for the sport type selection.
Microvascular Distribution in the Ocular Conjunctiva and Digestive Tract in an Experimental Setting
Authors: Pranskūnas Andrius , Pilvinis Vidas , Dambrauskas Žilvinas , Rasimavičiūtė Renata , Milieškaitė Eglė , Bubulis Algimantas , Veikutis Vincentas , Vaitkaitis Dinas , Boerma E.
Published: April 2018

microcirculation; conjunctiva; jejunum; rectum; pigs
Atomistic modeling of tribological properties of Pd and Al nanoparticles on a graphene surface
Authors: Khomenko Alexei , Zakharov Miroslav , Boyko Denis , Persson Bo N J
Published: April 2018

Background: The frictional properties of nanoparticles have been studied to gain insight into the fundamental origin of sliding friction.

Results: Using molecular dynamics we investigate frictional properties of aluminum and palladium nanoparticles deposited on a graphene layer. We study the time evolution of the total momentum of the system, the total and potential energies, the temperature, the velocity and position of the center of mass, the dimensions of the nanoparticle, and the friction and substrate forces acting on the particle. We also study how the friction force depends on the nanoparticle–graphene contact area and the temperature.

Conclusion: The tribological properties of nanoparticles strongly depend on the materials. The particles move in an irregular (saw-like) manner. The averaged friction force depends nearly linearly on the contact area and non-monotonously on temperature. We observe ordered crystalline domains of atoms at the bottom surface of the metal particles, but the peaks of radial distribution function are blurred indicating that the nanoparticles are amorphous or polycrystalline.
Computational exploration of two-dimensional silicon diarsenide and germanium arsenide for photovoltaic applications
Authors: Matta Sri Kasi , Zhang Chunmei , Jiao Yalong , O'Mullane Anthony , Du Aijun
Published: April 2018

The properties of bulk compounds required to be suitable for photovoltaic applications, such as excellent visible light absorption, favorable exciton formation, and charge separation are equally essential for two-dimensional (2D) materials. Here, we systematically study 2D group IV–V compounds such as SiAs2 and GeAs2 with regard to their structural, electronic and optical properties using density functional theory (DFT), hybrid functional and Bethe–Salpeter equation (BSE) approaches. We find that the exfoliation of single-layer SiAs2 and GeAs2 is highly feasible and in principle could be carried out experimentally by mechanical cleavage due to the dynamic stability of the compounds, which is inferred by analyzing their vibrational normal mode. SiAs2 and GeAs2 monolayers possess a bandgap of 1.91 and 1.64 eV, respectively, which is excellent for sunlight harvesting, while the exciton binding energy is found to be 0.25 and 0.14 eV, respectively. Furthermore, band-gap tuning is also possible by application of tensile strain. Our results highlight a new family of 2D materials with great potential for solar cell applications.
PARAMETER-UNIFORM IMPROVED HYBRID NUMERICAL SCHEME FOR SINGULARLY PERTURBED PROBLEMS WITH INTERIOR LAYERS
Authors: Mukherjee Kaushik
Published: April 2018

In this paper, we consider a class of singularly perturbed convection-diﬀusion boundary-value problems with discontinuous convection coeﬃcient which often occur as mathematical models for analyzing shock wave phenomena in gas dynamics. In general, interior layers appear in the solutions of this class of problems and this gives rise to diﬃculty while solving such problems using the classical numerical methods (standard central diﬀerence or standard upwind scheme) on uniform meshes when the perturbation parameter ε is small. To achieve better numerical approximation in solving this class of problems, we propose a new hybrid scheme utilizing a layer-resolving piecewise-uniform Shishkin mesh and the method is shown to be ε-uniformly stable. In addition to this, it is proved that the proposed numerical scheme is almost second-order uniformly convergent in the discrete supremum norm with respect to the parameter ε. Finally, extensive numerical experiments are conducted to support the theoretical results. Further, the numerical results obtained by the newly proposed scheme are also compared with the hybrid scheme developed in the paper [Z.Cen, Appl. Math. Comput., 169(1): 689-699, 2005]. It shows that the current hybrid scheme exhibits a signiﬁcant improvement over the hybrid scheme developed by Cen, in terms of the parameter-uniform order of convergence.
Repeat Testing of Antibodies and Complements in Systemic Lupus Erythematosus: When Is It Enough?
Authors: Raissi Thomas C. , Hewson Carly , Pope Janet E.
Published: April 2018

Objective.

Patients with systemic lupus erythematosus (SLE) frequently undergo repeat testing for antibodies against extractable nuclear antigens (anti-ENA), but it is not known whether this is necessary or cost-effective. This study characterized the frequencies of changes in anti-ENA, anti–dsDNA, and complement C3 and C4 upon repeat testing.

Methods.

Chart review was done at one site of 130 patients with SLE enrolled in the 1000 Canadian Faces of Lupus prospective registry with annual antibody and complement testing. We determined the frequency of seroconversion (changes) on the next test and over the entire followup given 1 or multiple consistent results, and the cost to detect these changes.

Results.

Overall, 89.4% of patients had no changes in anti-ENA screening results from the first available test, 3.3% changed from negative to positive, and 7.3% from positive to negative. Following a single anti-ENA test, 3.9% of negative tests changed to positive and 4.2% of positive changed to negative on the next test. After multiple consistent tests, the frequencies of changes progressively declined. No changes from the first test were observed in anti-dsDNA, C3, and C4 in 60.8%, 83.3%, and 75.4% of patients, respectively. After 2 consistent anti-ENA tests, the cost to detect 1 change was above US$2000.

Conclusion.

Anti-ENA results change infrequently, especially following 1 or more negative tests. The high cost and lack of evidence that changes affect management suggest that repeating anti-ENA tests routinely is unnecessary. Anti-dsDNA and complements change more frequently after an abnormal result, but less after a normal value.
The Prevalence of Renal Impairment in Patients with Spondyloarthritis: Results from the International ASAS-COMOSPA Study
Authors: Couderc Marion , Pereira Bruno , Molto Anna , Tiple Aurélien , Soubrier Martin , Dougados Maxime
Published: April 2018

Objective.

To assess the prevalence and association of renal dysfunction in patients with spondyloarthritis (SpA).

Methods.

The ASAS-COMOSPA (Assessment of Spondyloarthritis international Society-COMOrbidities in SPondyloArthritis) was an international study (22 participating countries from 4 continents) investigating comorbidities in SpA. Renal function was assessed based on estimated glomerular filtration rate (eGFR) calculated using the Modification of Diet in Renal Disease equation. SpA characteristics and risk factors for renal impairment were collected. Nonsteroidal antiinflammatory drug (NSAID) use was assessed based on current intake (last 3 mos).

Results.

Of the 3984 patients recruited, 2098 (52.6%) were analyzed after excluding outliers and patients with no available eGFR measurement [male sex: 63.5%; age: 45.3 yrs; disease duration: 8.6 years; HLA-B27+: 73.1%; Bath Ankylosing Spondylitis Activity Index (BASDAI): 3.6/10]. Overall, 153 patients (5.2%, mean age: 53.6 yrs) exhibited an eGFR < 60 ml/min/1.73 m2. In univariate analysis, renal impairment was associated with age (p < 0.001), HLA-B27 positivity (p = 0.003), several cardiovascular (CV) risk factors (history of hypertension, p < 0.001; systolic blood pressure, p = 0.009; diabetes, p = 0.005; and Framingham risk score, p < 0.001), disease activity scores [BASDAI, p = 0.001; Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP), p < 0.001], functional variables (Bath Ankylosing Spondylitis Functional Index, p < 0.001), inflammatory biomarkers (erythrocyte and CRP, both p < 0.001), and NSAID intake since onset of disease (percentage of days, p = 0.008). However, there was no association with disease duration, disease severity, or ASAS-NSAID score. In multivariate analysis, age (45–59 yrs: OR 1.9, > 60 yrs: OR 6.2), HLA-B27 positivity (OR 0.51), and CRP (OR 1.3) remained significantly associated with eGFR < 60 ml/min/1.73 m2.

Conclusion.

Renal impairment was associated with age, HLA-B27 positivity, and inflammation, though not with CV risk factors, disease severity, or NSAID intake in patients with SpA.
Causes and Predictors of Early Hospital Readmission in Systemic Lupus Erythematosus
Authors: Nangit Angelica , Lin Connie , Ishimori Mariko L. , Spiegel Brennan M.R. , Weisman Michael H.
Published: April 2018

Objective.

We investigated characteristics of adult patients with systemic lupus erythematosus (SLE) readmitted to the hospital within 30 days of discharge, in an attempt to identify the causes of early readmission.

Methods.

We performed a retrospective case-control study examining all inpatient electronic health records of patients with SLE at Cedars-Sinai Medical Center over a 2.5-year period (2012–2014). Patients were included if they had an International Classification of Diseases, 9th ed diagnosis of SLE and were readmitted within 30 days of their initial hospitalization. Patients with SLE not readmitted during this time period were used as a control group. Demographic and clinical variables for each patient were collected, and we used the Charlson Comorbidity Index to characterize comorbidities. The Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) was used to assess the chronic damage of SLE. Stepwise multivariable logistic regression analysis was used to predict factors associated with readmission.

Results.

In total, 570 hospitalizations representing 455 unique patients met our inclusion and exclusion criteria. Of these, 154 patients (34%) underwent readmission within 30 days of their initial hospitalization. Patients in the early readmission group were more likely to have government-sponsored Medicaid insurance and were significantly associated with an increased SDI (OR 1.27, 95% CI 1.1–1.48), lower serum hemoglobin (OR 0.82, 95% CI 0.72–0.93), and lower serum albumin (OR 0.66, 95% CI 0.47–0.91).

Conclusion.

One-third of hospitalized patients with SLE were readmitted within 30 days at our institution. We identified characteristics of this at-risk population at time of discharge with high specificity, in hopes of reducing this costly outcome.
Venous Thromboembolism in Systemic Sclerosis: Prevalence, Risk Factors, and Effect on Survival
Authors: Johnson Sindhu R. , Hakami Nabil , Ahmad Zareen , Wijeysundera Duminda N.
Published: April 2018

Objective.

Whether systemic sclerosis (SSc) confers increased risk of venous thromboembolism (VTE) is uncertain. We evaluated the prevalence, risk factors, and effect of VTE on SSc survival.

Methods.

A cohort study was conducted of subjects with SSc who fulfilled the American College of Rheumatology/European League Against Rheumatism classification criteria between 1970 and 2017. Deep vein thrombosis was defined as thrombus on extremity ultrasound. Pulmonary embolism was defined as thrombus on thorax computed tomography angiogram. Risk factors for VTE and time to all-cause mortality were evaluated.

Results.

Of the 1181 subjects, 40 (3.4%) experienced VTE events. The cumulative incidence of VTE was 2.7 (95% CI 1.9–3.7) per 1000 patient-years. Pulmonary arterial hypertension (PAH; OR 3.77, 95% CI 1.83–8.17), peripheral arterial disease (OR 5.31, 95% CI 1.99–12.92), Scl-70 (OR 2.45, 95% CI 1.07–5.30), and anticardiolipin antibodies (OR 5.70, 95% CI 1.16–21.17) were predictors of VTE. There were 440 deaths. There was no difference in survival between those with and without VTE (HR 1.16, 95% CI 0.70–1.91). Interstitial lung disease (HR 1.54, 95% CI 1.27–1.88) and PAH (HR 1.35, 95% CI 1.10–1.65) were predictors of mortality.

Conclusion.

The risk of VTE in SSc is comparable to the general population. The presence of PAH, peripheral arterial disease, Scl-70, and anticardiolipin antibodies are risk factors for VTE. VTE does not independently predict SSc survival.
Longterm Safety and Efficacy of Subcutaneous Abatacept in Patients with Rheumatoid Arthritis: 5-year Results from a Phase IIIb Trial
Authors: Genovese Mark C. , Pacheco-Tena César , Covarrubias Arturo , Leon Gustavo , Mysler Eduardo , Keiserman Mauro , Valente Robert M. , Nash Peter , Simon-Campos J. Abraham , Box Jane , Legerton Clarence W. , Nasonov Evgeny , Durez Patrick , Elegbe Ayanbola , Wong Robert , Li Xiaohui , Banerjee Subhashis , Alten Rieke
Published: April 2018

Objective.

To assess 5-year safety, tolerability, and efficacy of subcutaneous (SC) abatacept (ABA) in methotrexate (MTX)-refractory patients with rheumatoid arthritis (RA).

Methods.

The Abatacept Comparison of sub[QU]cutaneous versus intravenous in Inadequate Responders to methotrexatE (ACQUIRE) phase IIIb, randomized, double-dummy, multinational trial compared efficacy and safety of SC and intravenous (IV) ABA in patients with RA. In the initial 6-month double-blind (DB) period, patients received IV or SC ABA, plus MTX, and in the subsequent open-label longterm extension (LTE) period, all patients received SC ABA (125 mg/wk). The final 5-year safety, tolerability, and efficacy analyses are reported.

Results.

Of 1385 patients who completed the DB period, 1372 entered LTE and 945 (68.8%) completed ≥ 5 years of treatment. During LTE, 97 (7.1%) patients discontinued treatment because of an adverse event (AE). Incidence rate (IR; event/100 patient-yrs of exposure; based on LTE data, 95% CI) for AE of interest were the following: serious AE 7.73 (6.96–8.58), infection 38.60 (36.24–41.12), serious infection 1.68 (1.35–2.07), malignancies 1.09 (0.84–1.42), and autoimmune disorders 1.33 (1.05–1.69), and were stable over time. No association between immunogenicity and either worsening of ABA safety or loss of efficacy was noted. Efficacy in the LTE was consistent with the DB period and was maintained to the end of the study.

Conclusion.

These 5-year data establish that SC ABA (125 mg/wk) has a consistent safety profile and durable efficacy for longterm treatment of patients with RA who had an inadequate response to MTX.
Crystal-proven Gout and Characteristic Gout Severity Factors Are Associated with Cardiovascular Disease
Authors: Disveld Iris J.M. , Fransen Jaap , Rongen Gerard A. , Kienhorst Laura B.E. , Zoakman Sahel , Janssens Hein J.E.M. , Janssen Matthijs
Published: April 2018

Objective.

Our aim was to examine the prevalence of cardiovascular disease (CVD) in patients with crystal-proven gout compared to arthritis controls. Further, we analyzed the association between characteristic gout severity factors and CVD to provide further support for a pathogenetic relationship between gout and CVD.

Methods.

Patients with arthritis referred for diagnosis were consecutively included in the Gout Arnhem-Liemers cohort. Joint fluid analysis was performed in all referred patients; controls were negative for crystals. Patients’ characteristics and different manifestations of CVD and gout severity factors (disease duration, attack frequency, tophi, affected joints, high serum urate acid level, joint damage) were collected. Gout patients were compared with controls for the prevalence of CVD. In addition, the association between characteristic gout severity factors and presence of CVD was analyzed.

Results.

Data from 700 gout patients and 276 controls were collected. CVD was present in 47% (95% CI 44%–51%) and 24% (95% CI 19%–29%) of gout patients and controls, respectively. Corrected for confounders, gout was still strongly associated with an increased prevalence of CVD compared to controls (OR 3.39, 95% CI 2.37–4.84). In patients with gout, disease duration ≥ 2 years, oligo- or polyarthritis, serum urate acid > 0.55 mmol/l at presentation, and joint damage were independently (p < 0.05) associated with prevalent CVD.

Conclusion.

Crystal-proven gout was strongly associated with an increased prevalence of CVD. In patients with gout, characteristic gout severity factors were associated with CVD.
Power Doppler Ultrasound Evaluation of Peripheral Joint, Entheses, Tendon, and Bursa Abnormalities in Psoriatic Patients: A Clinical Study
Authors: Tang Yuanjiao , Yang Yujia , Xiang Xi , Wang Liyun , Zhang Lingyan , Qiu Li
Published: April 2018

Objective.

To evaluate the prevalence rates of peripheral joint, enthesis, tendon, and bursa abnormalities by power Doppler (PD) ultrasonic examination in patients with psoriatic arthritis (PsA), psoriatic patients without clinical signs of arthritis (non-PsA psoriasis group), and healthy individuals, to detect subclinical PsA.

Methods.

A total of 253 healthy volunteers, 242 non-PsA psoriatic patients, and 86 patients with PsA were assessed by 2-dimensional and power Doppler (PD) ultrasound. Peripheral joint, enthesis, tendon, and bursa abnormalities were observed, characterizing abnormal PD. The affected patients and sites with abnormalities in various ages were compared among groups; PD signal grades for the abnormalities were also compared.

Results.

In the PsA group, significantly higher percentages of sites showing joint effusion/synovitis, enthesitis, and tenosynovitis in all age groups, and markedly higher rates of sites with bursitis were found in young and middle age groups, compared with the non-PsA and control groups (all p < 0.01). Meanwhile, the non-PsA group showed significantly higher rates of joint effusion/synovitis and enthesitis sites, and elevated PD signal grades of synovitis, enthesitis, and tenosynovitis in comparison with the control group, both in young and middle age groups (all p < 0.01).

Conclusion.

Patients with PsA have high percentages and PD signal grades of peripheral joint, tendon, enthesis, and bursa involvement. Young and middle-aged non-PsA patients have high synovitis and enthesitis percentages, and elevated PD signal grades of synovitis, enthesitis, and tenosynovitis.
Absence of Fibrosis and Inflammation by Cardiac Magnetic Resonance Imaging in Rheumatoid Arthritis Patients with Low to Moderate Disease Activity
Authors: Bradham William , Ormseth Michelle J. , Elumogo Comfort , Palanisamy Srikanth , Liu Chia-Ying , Lawson Mark A. , Soslow Jonathan H. , Kawel-Boehm Nadine , Bluemke David A. , Stein C. Michael
Published: April 2018

Objective.

The prevalence of heart failure is increased 2-fold in patients with rheumatoid arthritis (RA); this is not explained by ischemic heart disease or other risk factors for heart failure. We hypothesized that in patients with RA without known heart disease, cardiac magnetic resonance imaging (cMRI) would detect altered cardiac structure, function, and fibrosis.

Methods.

We performed 1.5-T cMRI in 59 patients with RA and 56 controls frequency-matched for age, race, and sex, and compared cMRI indices of structure, function, and fibrosis [late gadolinium enhancement (LGE), native T1 mapping, and extracellular volume (ECV)] using Mann-Whitney U tests and linear regression, adjusting for age, race, and sex.

Results.

Most patients with RA had low to moderate disease activity [28-joint count Disease Activity Score–C-reactive protein median 3.16, interquartile range (IQR) 2.03–4.05], and 49% were receiving anti-tumor necrosis factor agents. Left ventricular (LV) mass, LV end-diastolic and -systolic volumes indexed to body surface area, and LV ejection fraction and left atrial size were not altered in RA compared to controls (all p > 0.05). Measures of fibrosis were not increased in RA: LGE was present in 2 patients with RA and 1 control subject; native T1 mapping was similar comparing RA and control subjects, and ECV (median, IQR) was lower (26.6%, 24.7–28.5%) in patients with RA compared to control subjects (27.5%, 25.4–30.4%, p = 0.03).

Conclusion.

cMRI measures of cardiac structure and function were not significantly altered, and measures of fibrosis were similar or lower in RA patients with low to moderate disease activity compared to a matched control group.
Age- and Sex-dependent Frequency of Fat Metaplasia and Other Structural Changes of the Sacroiliac Joints in Patients without Axial Spondyloarthritis: A Retrospective, Cross-sectional MRI Study
Authors: Ziegeler Katharina , Eshkal Hamama , Schorr Claudia , Sieper Joachim , Diekhoff Torsten , Makowski Marcus R. , Hamm Bernd , Hermann Kay-Geert A.
Published: April 2018

Objective.

To determine the prevalence of fat metaplasia and other structural lesions of the sacroiliac joints associated with axial spondyloarthritis in a nonrheumatological patient population.

Methods.

Magnetic resonance imaging examinations that included the pelvis and were performed in patients without known rheumatological disease were used for this retrospective cross-sectional study. These images were evaluated for sacroiliac fat metaplasia, sclerosis, osteophytes, and joint space alterations such as erosions or ankylosis. Patients were divided into 7 age groups (15–24 to ≥ 75 yrs). Prevalence of lesions across age groups was calculated. Possible clinical confounders (e.g., status post radiation, suspected inflammatory bowel disease) were investigated regarding their effect on lesion prevalence and extent, to exclude bias.

Results.

A total of 485 patients were enrolled. Fat metaplasia was very common and increased with age, from a prevalence of 50.6% in the age groups < 45, to 94.4% in patients ≥ 75 years. Erosions were uncommon: 0.6% of patients < 45, and 2.6% of the entire study population exhibited this feature, with no detectable age-dependent increase. Sclerosis and osteophytes were detected in 13.7% and 37.0% of patients, respectively. None of the investigated clinical confounders had a significant effect on lesion prevalence.

Conclusion.

Our study shows a very high prevalence of fat metaplasia adjacent to the sacroiliac joint in asymptomatic patients, while erosions are extremely uncommon.
HLA-DRB1 Shared Epitope Alleles and Disease Activity Are Correlated with Reduced T Cell Receptor Repertoire Diversity in CD4+ T Cells in Rheumatoid Arthritis
Authors: Sakurai Keiichi , Ishigaki Kazuyoshi , Shoda Hirofumi , Nagafuchi Yasuo , Tsuchida Yumi , Sumitomo Shuji , Kanda Hiroko , Suzuki Akari , Kochi Yuta , Yamamoto Kazuhiko , Fujio Keishi
Published: April 2018

Objective.

Shared epitope (SE) alleles are the most significant genetic susceptibility locus in rheumatoid arthritis (RA); however, their target populations in CD4+ T cells are not well elucidated. We analyzed the association between SE alleles and the T cell receptor (TCR) repertoire diversity of naive and memory CD4+ T cells using next-generation sequencing (NGS).

Methods.

The TCR beta chains in naive and memory CD4+ T cells from the peripheral blood of 22 patients with RA and 18 age- and sex-matched healthy donors (HD) were analyzed by NGS. The Renyi entropy was used to evaluate TCR repertoire diversity and its correlations with SE alleles and other variables were examined. Serum cytokine levels were measured by multiplex ELISA.

Results.

The TCR repertoire diversity in memory CD4+ T cells was reduced in SE allele-positive patients with RA compared with HD, and showed a significant negative correlation with the SE allele dosage in RA. The TCR repertoire diversity of naive and memory T cells was also negatively correlated with disease activity, and the SE allele dosage and disease activity were independently associated with reduced TCR repertoire diversity. TCR repertoire diversity showed a significant positive correlation with the serum interleukin 2 levels.

Conclusion.

SE alleles and disease activity were negatively correlated with the TCR repertoire diversity of CD4+ T cells in RA. Considering the pivotal role of CD4+ T cells in RA, restoring the altered TCR repertoire diversity will provide a potential RA therapeutic target.
Clinical and Serological Associations with the Development of Incident Proteinuria in Danish Patients with Systemic Lupus Erythematosus
Authors: Tanha Nima , Hansen Renata Baronaite , Nielsen Christoffer Tandrup , Faurschou Mikkel , Jacobsen Søren
Published: April 2018

Objective.

In a longitudinal cohort study, we investigated whether clinical and serological manifestations at the time of classification of systemic lupus erythematosus (SLE) were predictive of subsequent development of incident proteinuria as a biomarker of incident lupus nephritis.

Methods.

Patients fulfilling SLE classification criteria but having no proteinuria prior to or at the time of classification were included. Data on SLE manifestations, vital status, criteria-related autoantibodies, and SLE-associated medications were collected during clinical visits and supplemented by chart review. HR were calculated by Cox regression analyses.

Results.

Out of 850 patients with SLE, 604 had not developed proteinuria at the time of SLE classification. Of these 604 patients, 184 (30%) developed incident proteinuria following SLE classification. The patients had a median followup of 11 years and 7 months. Younger age and history of psychosis at the time of classification were associated with development of incident proteinuria, just as were lymphopenia (HR 1.49, 95% CI 1.08–2.06), anti-dsDNA (HR 1.38, 95% CI 1.01–1.87), and a high number of autoantibodies (HR 1.26, 95% CI 1.06–1.48).

Conclusion.

The risk of incident proteinuria after onset of SLE was increased by the presence of lymphopenia, anti-dsDNA antibodies, psychosis, younger age, and a high number of autoantibodies at onset.