bluuebunny/crossref_metadata_2025 huggingface dataset:
Shocks inside CMEs: A survey of properties from 1997 to 2006
Authors: Lugaz N. , Farrugia C. J. , Smith C. W. , Paulson K.
Published: March 2015

We report on 49 fast‐mode forward shocks propagating inside coronal mass ejections (CMEs) as measured by Wind and ACE at 1 AU from 1997 to 2006. Compared to typical CME‐driven shocks, these shocks propagate in different upstream conditions, where the median upstream Alfvén speed is 85 km s−1, the proton β = 0.08 and the magnetic field strength is 8 nT. These shocks are fast with a median speed of 590 km s−1 but weak with a median Alfvénic Mach number of 1.9. They typically compress the magnetic field and density by a factor of 2–3. The most extreme upstream conditions found were a fast magnetosonic speed of 230 km s−1, a plasma β of 0.02, upstream solar wind speed of 740 km s−1 and density of 0.5 cm−3. Nineteen of these complex events were associated with an intense geomagnetic storm (peak Dst under −100 nT) within 12 h of the shock detection at Wind, and 15 were associated with a drop of the storm time Dst index of more than 50 nT between 3 and 9 h after shock detection. We also compare them to a sample of 45 shocks propagating in more typical upstream conditions. We show the average property of these shocks through a superposed epoch analysis, and we present some analytical considerations regarding the compression ratios of shocks in low β regimes. As most of these shocks are measured in the back half of a CME, we conclude that about half the shocks may not remain fast‐mode shocks as they propagate through an entire CME due to the large upstream and magnetosonic speeds.
Toward hyper‐resolution land‐surface modeling: The effects of fine‐scale topography and soil texture on CLM4.0 simulations over the Southwestern U.S.
Authors: Singh R. S. , Reager J. T. , Miller N. L. , Famiglietti J. S.
Published: March 2015

Increasing computational efficiency and the need for improved accuracy are currently driving the development of “hyper‐resolution” land‐surface models that can be implemented at continental scales with resolutions of 1 km or finer. Here we report research incorporating fine‐scale grid resolutions into the NCAR Community Land Model (CLM v4.0) for simulations at 1, 25, and 100 km resolution using 1 km soil and topographic information. Multiyear model runs were performed over the Southwestern U.S., including the entire state of California and the Colorado River basin. The results show changes in the total amount of CLM‐modeled water storage, and changes in the spatial and temporal distributions of water in snow and soil reservoirs, as well as changes in surface fluxes and the energy balance. To inform future model progress and continued development needs and weaknesses, we compare simulation outputs to station and gridded observations of model fields. Although the higher grid‐resolution model is not driven by high‐resolution forcing, grid resolution changes alone yield significant improvement (reduction in error) between model outputs and observations, where the RMSE decreases by more than 35%, 36%, 34%, and 12% for soil moisture, terrestrial water storage anomaly, sensible heat, and snow water equivalent, respectively. As an additional exercise, we performed a 100 m resolution simulation over a spatial subdomain. Those results indicate that parameters such as drainage, runoff, and infiltration are significantly impacted when hillslope scales of ∼100 m or finer are considered, and we show the ways in which limitations of the current model physics, including no lateral flow between grid cells, may affect model simulation accuracy.
Inverse sequential simulation: A new approach for the characterization of hydraulic conductivities demonstrated on a non‐Gaussian field
Authors: Xu Teng , Gómez‐Hernández J. Jaime
Published: March 2015

Inverse sequential simulation (iSS) is a new inverse modeling approach for the characterization of hydraulic conductivity fields based on sequential simulation. It is described and demonstrated in a synthetic aquifer with non‐Gaussian spatial features, and compared against the normal‐score ensemble Kalman filter (NS‐EnKF). The new approach uses the sequential simulation paradigm to generate realizations borrowing from the ensemble Kalman filter the idea of using the experimental nonstationary cross‐covariance between conductivities and piezometric heads computed on an ensemble of realizations. The resulting approach is fully capable of retrieving the non‐Gaussian patterns of the reference field after conditioning on the piezometric heads with results comparable of those obtained by the NS‐EnKF.
A unified approach for process‐based hydrologic modeling: 2. Model implementation and case studies
Authors: Clark Martyn P. , Nijssen Bart , Lundquist Jessica D. , Kavetski Dmitri , Rupp David E. , Woods Ross A. , Freer Jim E. , Gutmann Ethan D. , Wood Andrew W. , Gochis David J. , Rasmussen Roy M. , Tarboton David G. , Mahat Vinod , Flerchinger Gerald N. , Marks Danny G.
Published: March 2015

This work advances a unified approach to process‐based hydrologic modeling, which we term the “Structure for Unifying Multiple Modeling Alternatives (SUMMA).” The modeling framework, introduced in the companion paper, uses a general set of conservation equations with flexibility in the choice of process parameterizations (closure relationships) and spatial architecture. This second paper specifies the model equations and their spatial approximations, describes the hydrologic and biophysical process parameterizations currently supported within the framework, and illustrates how the framework can be used in conjunction with multivariate observations to identify model improvements and future research and data needs. The case studies illustrate the use of SUMMA to select among competing modeling approaches based on both observed data and theoretical considerations. Specific examples of preferable modeling approaches include the use of physiological methods to estimate stomatal resistance, careful specification of the shape of the within‐canopy and below‐canopy wind profile, explicitly accounting for dust concentrations within the snowpack, and explicitly representing distributed lateral flow processes. Results also demonstrate that changes in parameter values can make as much or more difference to the model predictions than changes in the process representation. This emphasizes that improvements in model fidelity require a sagacious choice of both process parameterizations and model parameters. In conclusion, we envisage that SUMMA can facilitate ongoing model development efforts, the diagnosis and correction of model structural errors, and improved characterization of model uncertainty.
Ribonucleotide Reduction
Authors: Gleason Florence K
Published: March 2015

Ribonucleotide reductase is an essential enzyme that supplies the deoxyribonucleotides required for DNA synthesis and repair. This one enzyme reduces all four ribonucleotides to the corresponding deoxynucleotides. The enzyme uses a complex radical‐based mechanism to catalyse this reaction. Three main classes of enzymes have been described that differ mainly in the type of cofactor used to generate the catalytic radical. Despite their common reaction mechanism, ribonucleotide reductases show little sequence identity. Crystal structures of enzymes from all classes show a conserved β/α barrel structure in the catalytic domain. Reductase activity is regulated at the protein level by nucleotide allosteric effectors to produce balanced pools of deoxynucleotides. Reductase activity is also coordinated with the cell cycle by activation and repression of gene expression.

Key Concepts

Deoxyribonucleotides required for DNA synthesis and repair are generated only by reduction of ribonucleotides.

One enzyme, ribonucleotide reductase, must reduce all four common ribonucleotides and generate a balanced pool of deoxyribonucleotides to avoid mutations.

Although an essential enzyme in all divisions of life, ribonucleotide reductases diverge widely in primary structure and cofactor requirements.

Ribonucleotide reductase is regulated both at the protein and gene level and can accommodate to environmental changes in the evolution of diverse organisms.

Evolution of ribonucleotide reductases is constrained only by basic catalytic chemistry and protein tertiary structure.
Mitosis: Chromosome Segregation and Stability
Authors: Mustaly Hatim M , Ganem Neil J
Published: March 2015

Mammalian cells are charged with the task of evenly distributing 46 chromosomes to each of two daughter cells during every mitotic cell division. This is achieved by a microtubule‐based cellular structure termed the mitotic spindle. However, numerous cellular and/or genetic defects are known to impair the fidelity of mitosis and promote chromosome segregation errors and aneuploidy. Missegregation of even a single chromosome leads to the deregulated expression of hundreds to thousands of genes, including many that are involved in essential processes such as DNA replication, repair and mitosis. Consequently, while aneuploidy is most typically detrimental to cell viability, it also has the potential to initiate a self‐propagating cycle of chromosome instability that can ultimately promote tumour initiation, progression and relapse.

Key Concepts

Chromosome segregation is driven by the mitotic spindle.

Multiple genetic and/or cell biological defects are known to cause chromosome missegregation and aneuploidy.

Aneuploidy is poorly tolerated in normal cells.

Cancer cells adapt to tolerate aneuploidy.

Cells that persistently missegregate chromosomes are termed chromosomally unstable (CIN).

CIN promotes tumour initiation, progression and relapse and correlates with poor patient prognosis.

Aneuploidy and CIN are hallmarks of human tumours.
Genetics of Eye Colour
Authors: Duffy David
Published: March 2015

Human eye colour is a polygenic trait with a heritability of close to 100%, with seven leading factors explaining three‐quarters of the genetic variance:
OCA2
,
TYR
,
TYRP1
,
IRF4
,
SLC45A2
,
SLC24A5
and
SLC24A4
. Many of these genes were already known to be mutated in oculocutaneous albinism, and all are involved in melanin biosynthesis, coding for key enzymes, transcription factors controlling expression of key enzymes or transporters that maintain the acidity of the melanosome interior. At least two of the variants of largest effect abrogate regulatory elements in the associated gene, causing changes in expression level. The differences in eye colour between different populations suggest strong selection, either on correlated traits such as skin colour or perhaps directly.

Key Concepts

Variation in eye colour is polygenic, with seven major genes explaining 75% of European population variance.

Blue eye colour is strongly predicted by a single nucleotide polymorphism near the
OCA2
gene – this is the classical recessive gene inferred from family data. Intermediate eye colours such as hazels and greens are less well predicted.

Two of the major loci are in non‐coding regulatory regions, a pattern common to trait loci for other complex traits.

The large effect sizes make this an excellent model for the investigation of the architecture of gene action, especially gene‐by‐gene interactions (epistasis), as well as multi‐trait action (pleiotropy).

Iris pigmentation loci generally exhibit genomic evidence of strong Darwinian selection, and this may not be completely explained by pleiotropic effects on skin colour.
Effect of a Realigning Brace on Tibiofemoral Contact Stress
Authors: Segal Neil A. , Stockman Tyler J. , Findlay Christian M. , Kern Andrew M. , Ohashi Kenjirou , Anderson Donald D.
Published: March 2015

Objective

To determine the degree to which focally elevated tibiofemoral joint contact stress is reduced by using a frontal plane realigning brace.

Methods

Fifteen volunteers (9 women) with unicompartmental tibiofemoral osteoarthritis underwent weight‐bearing radiographic imaging at 15–20° and 5–10° of knee flexion with and without an UnloaderOne knee brace. Discrete element analysis was used to estimate compartment‐specific contact stress distributions. Paired t‐tests were used to assess the differences in mean contact stress and contact stress distributions, comparing the braced and unbraced conditions.

Results

The mean ± SD age was 56.1 ± 6.4 years and body mass index was 28.4 ± 4.5 kg/m2. Twelve of 15 participants were fit with braces set to unload the medial compartment. For the 15–20° condition, the mean contact stress in the compartment of interest did not significantly change (0.08 ± 0.35 MPa; P = 0.410). Also at 5–10° flexion, the mean contact stress in the compartment of interest did not significantly change with use of the brace (0.24 ± 0.45 MPa; P = 0.175).

Conclusion

This is the first study of the effects of a frontal plane realignment brace on in vivo articular contact stress in native human knees. Using the off‐the‐shelf brace tested, there were no changes in compartmental tibiofemoral contact stress distributions at either 15–20° or 5–10° of knee flexion, revealing no redistribution of contact stress away from the compartment of interest. These findings indicate that the brace that was studied was ineffective for redistributing tibiofemoral contact stress. Further research is necessary to determine whether double‐upright or customized frontal plane braces are effective in redistributing compartmental articular contact stress.
Feel the Fatigue and Be Active Anyway: Physical Activity on High‐Fatigue Days Protects Adults With Arthritis From Decrements in Same‐Day Positive Mood
Authors: Hegarty Rosisin S. M. , Conner Tamlin S. , Stebbings Simon , Treharne Gareth J.
Published: March 2015

Objective

The present study examined whether daily physical activity moderated the within‐person relationship between daily fatigue and positive or negative mood in patients with rheumatoid arthritis (RA) or osteoarthritis (OA).

Methods

Participants were 142 patients, 70 with RA and 72 with OA (67.6% women). Participants completed daily diaries during 4 fixed time windows per day for 7 days. Each diary assessed fatigue, pain, and positive and negative mood. Participants wore pedometers throughout each day and recorded pedometer readings at the end of each day.

Results

Physical activity buffered the same‐day relationship between daily fatigue and positive mood for both RA and OA participants. On high‐fatigue days, large decrements in mood were noted, but this was mitigated on days when participants were more physically active.

Conclusion

Being more physically active on high‐fatigue days buffered the negative effect of fatigue on positive mood among adults with both OA and RA. These findings have implications for understanding the daily variations in fatigue and inform potential clinical interventions.
Sex Differences and Impact of Body Mass Index on the Time Course of Knee Range of Motion, Knee Strength, and Gait Speed After Total Knee Arthroplasty
Authors: Pua Yong‐Hao , Seah Felicia Jie‐Ting , Seet Felicia Jia‐Hui , Tan John Wei‐Ming , Liaw Jennifer Suet‐Ching , Chong Hwei‐Chi
Published: March 2015

Objective

Quadriceps strength deficits and gait speed limitations remain significant issues after total knee arthroplasty (TKA), yet detailed longitudinal data characterizing these measures and their predictors are limited. This study aimed to describe the time course of knee range of motion, quadriceps strength, and gait speed post‐TKA, and to assess whether sex and body mass index (BMI) influenced the time recovery of these measures.

Methods

A total of 1,025 patients (mean ± SD age 67 ± 8 years) undergoing primary TKA participated. At 4‐, 8‐, 12‐, and 16‐weeks postsurgery, knee range of motion, quadriceps strength, and gait speed were quantified. The associations of the knee and gait measures profile over time with sex and BMI were assessed using generalized least squares modeling.

Results

The various knee and gait measures improved nonlinearly over time, with substantial improvements observed in the first 8–10 weeks postsurgery. Sex and BMI influenced the time course of quadriceps strength (P < 0.001 for all interactions): improvements in quadriceps strength over time were slower in women and in patients with higher BMI. Post‐TKA gait speed was consistently lower in women than in men, while BMI was negatively and nonlinearly related to gait speed.

Conclusion

Although the various knee and gait measures improved over time, women and patients with higher BMI had poorer functional outcomes. The present study highlights the need for a mechanistic understanding of the results and targeted management of these patient subgroups.
Diagnosis, Monitoring, and Treatment of Systemic Lupus Erythematosus: A Systematic Review of Clinical Practice Guidelines
Authors: Tunnicliffe David J. , Singh‐Grewal Davinder , Kim Siah , Craig Jonathan C. , Tong Allison
Published: March 2015

Objective

Management of systemic lupus erythematosus (SLE) is complex and variability in practices exists. Guidelines have been developed to help improve the management of SLE patients, but there has been no formal evaluation of these guidelines. This study aims to compare the scope, quality, and consistency of clinical practice guidelines on the diagnosis, monitoring, and treatment of patients with SLE.

Methods

Electronic databases were searched up to April 2014. The Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument and textual synthesis was used to appraise and compare recommendations.

Results

Nine clinical practice guidelines and 5 consensus statements were identified, which covered 7 topics: diagnosis, monitoring, treatment, neuropsychiatric SLE, lupus nephritis, antiphospholipid syndrome, and other manifestations of lupus. The methodological quality of the guidelines was variable, with the overall mean AGREE II scores ranging from 31% to 75%, out of a maximum 100%. Scores were consistently low for applicability, with only 1 guideline scoring above 50%. There was substantial variability in the treatments recommended for class II and V lupus nephritis, the recommended duration of maintenance therapy for class III/IV lupus nephritis (from 1 to 4 years), and timing of ophthalmologic examination for patients taking corticosteroids.

Conclusion

Published guidelines on SLE cover a complex area of clinical care, but the methodological quality, scope, and recommendations varied substantially. Collaborative and multidisciplinary efforts to develop comprehensive, high‐quality evidence‐based guidelines are needed to promote best treatment and health outcomes for patients with SLE.
Multiscale Assembly of Superinsulating Silica Aerogels Within Silylated Nanocellulosic Scaffolds: Improved Mechanical Properties Promoted by Nanoscale Chemical Compatibilization
Authors: Zhao Shanyu , Zhang Zheng , Sèbe Gilles , Wu Rudder , Rivera Virtudazo Raymond V. , Tingaut Philippe , Koebel Matthias M.
Published: March 2015

Silica aerogels are amongst the lightest mesoporous solids known and well recognized for their superinsulating properties, but the weak mechanical properties of the inorganic network structure has often narrowed their field of application. Here, the inherent brittleness of dried inorganic gels is tackled through the elaboration of a strong mesoporous silica aerogel interpenetrated with a silylated nanocellulosic scaffold. To this avail, a functionalized scaffold is synthesized by freeze‐drying an aqueous suspension of nanofibrillated cellulose (NFC)—a bio‐based nanomaterial mechanically isolated from renewable resources—in the presence of methyltrimethoxysilane sol. The silylated NFC scaffold displays a high porosity (>98%), high flexibility, and reduced thermal conductivity (λ) compared with classical cellulosic structures. The polysiloxane layer decorating the nanocellulosic scaffold is exploited to promote the attachment of the mesoporous silica matrix onto the nanofibrillated cellulose scaffold (NFCS), leading to a reinforced silica hybrid aerogel with improved thermomechanical properties. The highly porous (>93%) silica‐NFC hybrids displays meso‐ and macroporosity with pore diameters controllable by the NFCS mass fraction, reduced linear shrinkage, improved compressive properties (55% and 126% increase in Young's modulus and tensile strength, respectively), while maintaining superinsulating properties (λ ≤ 20 mW (m K)–1). This study details a new direction for the synthesis of multiscale hybrid silica aerogel structures with tailored properties through the use of alkyltrialkoxysilane prefunctionalized nanocellulosic scaffolds.
TAPE: A Medical Adhesive Inspired by a Ubiquitous Compound in Plants
Authors: Kim Keumyeon , Shin Mikyung , Koh Mi‐Young , Ryu Ji Hyun , Lee Moon Sue , Hong Seonki , Lee Haeshin
Published: March 2015

Adhesives play an important role in industrial fields such as electronics, architectures, energy plantation, and others. However, adhesives used for medical purpose are rather under‐developed compared with those used in industry and consumer products. One key property required for medical adhesives is to maintain their adhesiveness in the presence of body fluid. Here, an entirely new class of medical adhesives called TAPE is reported; this is produced by intermolecular hydrogen bonding between a well‐known polyphenol compound, tannic acid, and poly(ethylene glycol). The preparation method of TAPE is extremely easy, forming a few liters at once by just the simple mixing of the two compounds without any further chemical synthetic procedures. TAPE shows a 250% increase in adhesion strength compared with fibrin glue, and the adhesion is well maintained in aqueous environments. It is demonstrated that TAPE is an effective hemostatic material and a biodegradable patch for detecting gastroesophageal reflux disease in vivo. Widespread use of TAPE is anticipated in various medical and pharmaceutical applications such as muco‐adhesives, drug depots, and others, because of its scalability, adhesion, and facile preparation.
When Nanoparticles Meet Poly(Ionic Liquid)s: Chemoresistive CO2 Sensing at Room Temperature
Authors: Willa Christoph , Yuan Jiayin , Niederberger Markus , Koziej Dorota
Published: March 2015

Tetraalkylammonium‐based poly(ionic liquid)s (PILs) are able to absorb particularly large amounts of CO2; thus are considered up‐and‐coming materials in applications ranging from sensing, separation, to storage of CO2. To meet the requirements of practical usage, their chemical activity has to be combined with other functionalities, for example, by fabricating composite materials. Poly[(p‐vinylbenzyl)trimethylammonium hexafluorophosphate] and La2O2CO3 nanoparticles—both of which are intrinsically insulating materials—are utilized as building blocks, taking full advantage of the electrostatic interaction at their interface to boost the overall conductivity of composites at room temperature. To rationalize this unique behavior, the charge transport mechanism is studied using impedance spectroscopy. It is found find that, for the composites with La2O2CO3 content of 60–80 wt%, the interfacial effect becomes dominant and leads to the formation of conduction channels with increased mobility of [PF6]− anions. These composites show further increase of the conductivity when exposed to pulses of CO2 between 150 and 2400 ppm at room temperature in a relative humidity of 50%. This work therefore provides a simple strategy to achieve an enhancement of the electrical properties required for the utilization of PILs‐based CO2 sensors, but in the future this concept can be easily extended to other electronic devices.
Improving the Quality and Productivity of Molded Parts with a New Design of Conformal Cooling Channels for the Injection Molding Process
Authors: Rahim Shayfull Zamree Abd , Sharif S. , Zain Azlan Mohd , Nasir S. M. , Mohd Saad R.
Published: March 2015

In materials processing, quality and productivity are notably important and must be controlled for each product type produced. In the injection molding process, quality is measured as the extent of warpage of molded parts and productivity is measured in terms of the molding cycle time. This paper presents a new design of milled grooved square shape (MGSS) conformal cooling channels, which provide more uniformity in cooling with a larger effective cooling surface area compared to circular and other types of cooling channels with a similar cross‐section. This study examined the warpage of molded parts, and the cooling time, which affected the molding cycle time. A case study involving a front panel housing was performed, and the performance design of the MGSS conformal cooling channels was compared to that of conventional straight‐drilled cooling channels by simulation using Autodesk Moldflow Insight 2013 and validated experimentally. The result of MGSS conformal cooling channels is in a good agreement with the result of simulation. The MGSS conformal cooling channels reduced the warpage in both x and y directions by 14% to 54% and improved the cooling time by 65% compared to straight‐drilled cooling channels.
Characteristics and trends of emergency patients with drug overdose in Osaka
Authors: Kubota Yoshie , Hasegawa Kohei , Taguchi Hirokazu , Kitamura Tetsuhisa , Nishiyama Chika , Iwami Taku , Nishiuchi Tatsuya , Hiraide Atsushi
Published: March 2015

Aim

Drug overdose is an important issue in emergency medicine. However, studies covering overdose patients transported by ambulance have not been sufficiently carried out. We attempted to clarify problems of suspected drug overdose patients transported by ambulance.

Methods

This is a prospective population‐based cohort study. Data were collected by emergency medical service crews in Osaka City, Japan, between January 1998 and December 2010.

Results

Drug overdose cases increased annually from 1,136 in 1998 to 1,822 in 2010 (P < 0.0001 for trend). In these cases, the dominant age range was between 16 and 40 years and the age distribution did not change over time. The age of non‐overdose cases increased (P < 0.0001 for trend), with patients aged ≥66 years becoming most common in recent years, reflecting the aging of society. Males comprised most non‐overdose patients, but the percentage of females increased annually (P < 0.0001 in trend). Females comprised approximately 70% in overdose cases annually throughout the study period. The duration from the emergency call to the arrival at the hospital for overdose patients has increased markedly in recent years. It also takes more time to obtain acceptance from hospitals to care for patients of suspected overdose.

Conclusion

The characteristics of drug overdose patients are clearly different from those of non‐overdose patients. Recent trends of drug overdose patients indicate the accelerated burden on emergency medical services system.
Nonlinear viscoelastic modeling of soft polymers
Authors: Zacharatos Antonios , Kontou Evagelia
Published: March 2015

A one‐dimensional phenomenological constitutive model, representing the nonlinear viscoelastic behavior of polymers is developed in this study. The proposed model is based on a modification of the well‐known three element standard solid model. The linear dashpot is replaced by an Eyring type one, while the nonlinearity is enhanced by a nonlinear, strain dependent spring constant. The new constitutive model was proved to be capable of capturing the main aspects of nonlinear viscoelastic response, namely, monotonic and cyclic loading, creep and stress relaxation, with the same parameter values. Model validation was tested on the experimental results at various modes of deformation for two elastomeric type materials, performed elsewhere. A very good agreement between model simulations and experimental data was obtained in all cases. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42141.
Understanding and tailoring the degradation of PVA‐tyramine hydrogels
Authors: Lim Khoon S. , Roberts Justine J. , Alves Marie‐Helene , Poole‐Warren Laura A. , Martens Penny J.
Published: March 2015

We have previously reported on a hydrogel system fabricated from poly(vinyl alcohol) (PVA) functionalized with tyramine groups (PVA‐Tyr) that has the ability to co‐polymerize with proteins in their native state. These gels were also shown to be hydrolytically degradable through the ester groups present in the functional groups. In this article, the hydrolytic degradation of the PVA‐Tyr gels is shown to be strongly dependant on pH, where at pH < 7.4 the lack of ionization of the tyramine groups resulted in slower hydrolysis. The gels' degradation was also highly influenced by temperature, where heat (>25°C) was required to facilitate the hydrolysis of the ester bonds. Moreover, the degradation rates were successfully tailored between 19 to 27 days by varying the hydrogels' initial macromer concentration. It was highlighted that the cross‐linking density was dependant on the sodium persulphate to tyramine ratio, as well as the viscosity of the macromer solution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42142.
Chitosan‐based gel film electrolytes containing ionic liquid and lithium salt for energy storage applications
Authors: Chupp Jeremy , Shellikeri Annadanesh , Palui Goutam , Chatterjee Jhunu
Published: March 2015

Fabrication, characterization, and a comparative study have been performed for chitosan‐based polymer electrolytes using two different dispersion media. Chitosan gel film (solid) electrolytes are fabricated using acetic acid or adipic acid as the dispersant for chitosan in combination with ionic liquid and lithium salt. This quaternary system of chitosan, acetic acid or adipic acid, 1‐butyl‐3‐methylimadazolium tetrafluoroborate (ionic liquid), and lithium chloride is formed as an electrolyte for potential secondary energy storage applications. The ionic conductivities, thermal, structural, and morphological properties for these electrolytes are compared. The ionic conductivities for chitosan/adipic acid (CHAD) and for chitosan/acetic acid (CHAC) systems are in the range of 3.71 × 10−4−4.6 × 10−3 and 1.3 × 10−4 −3.2 × 10−3 S cm−1, respectively. The thermal stability of CHAD‐based electrolytes is determined to be higher than that of CHAC‐based electrolytes. Preliminary studies are performed to determine the electrochemical stability of these materials as solid film electrolytes for electrochemical supercapacitors. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42143.
Stille cross‐coupling applied to get higher molecular weight polymers: Synthesis, optoelectronic, Voc properties, and solar cell application
Authors: Hanif Muddasir , Chen Linlin , Zhu Li , Zhao Dan , Xiong Tianrou , Hou Haoqing
Published: March 2015

Conjugated polymers are highly desirable for the photovoltaic applications. We report the synthesis, characterization, optoelectronic properties, and solar cell application of two polymers, namely, poly[(9,9‐didodecylfluorene‐2,7‐diyl)‐alt‐(2,2′:5′,2″‐terthiophene‐5,5″‐diyl)] (P1) and poly[(1,4‐bis(dodecyloxy)benzene‐2,5‐diyl)‐alt‐(2,2′:5′,2″‐terthiophene‐5,5″‐diyl)] (P2). The polymers were synthesized via Stille cross‐coupling reaction, and were characterized by the gel permeation chromatography, nuclear magnetic resonance, Fourier transform infrared, UV–vis, thermogravimetric analysis, and cyclic voltammetry analyses. The two copolymers are processable due to their good solubility in organic solvents (tetrahydrofuran, CHCl3, toluene, chlorobenzene, and o‐dichlorobenzene). The optical band gaps (UV–vis, film, and Egopt) of the P1 and P2 are 2.04 and 2.00 eV, respectively. The density functional theory output structures showed that S…O space interaction is likely responsible for the higher planarity of P2. The polymers showed low HOMO energy levels (P1: −5.33 eV, P2: −5.05 eV). The EHOMO for P1 is close to the EHOMO (−5.4 eV) of an ideal polymer, which is an important, rare, and main origin of the observed higher Voc (801–808 mV). The onset decomposition temperatures (Td) for the P1 and P2 are 418°C and 365°C, respectively. The polymer solar cell based on the P1: C60 (1: 1) and P2: C60 (1: 1) blend showed a power conversion efficiency (PCE) of 0.94 and 0.71%, respectively. The composite polymer : PC60BM = 1 : 2 increased PCE of the P1 (1.65%) and P2 (1.09%) under AM 1.5 illumination (100 mW/cm2). The study provided important examples to design donor–donor (D–D) polymers for the photovoltaic applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42147.
On the Ability of Geophysical Methods to Image Medieval Turf Buildings in Iceland
Authors: Wunderlich Tina , Wilken Dennis , Andersen Jasmin , Rabbel Wolfgang , Zori Davide , Kalmring Sven , Byock Jesse
Published: March 2015

Structures in Iceland were traditionally built of turf, earth and, to a lesser extent, stone. As turf was the primary construction material, the contrast in geophysical parameters between building ruins and surrounding soil is expected to be low. To investigate the extent to which the remains of turf buildings can be detected by geophysical measurements, we applied several geophysical techniques to a known turf ruin in southwestern Iceland. The methods used were magnetics, ground‐penetrating radar (GPR), electromagnetic induction (EMI), electrical resistivity tomography (ERT) and seismic Rayleigh‐wave resonance mapping (RRM). Magnetics identified an accumulation of stones inside and beside the ruin. The in‐phase component of the EMI measurements, which can be related to magnetic susceptibility, showed the same pattern. A very precise image of the stones lining the inside of the former turf walls was generated by GPR. In contrast, EMI conductivity and ERT imaged the actual turf in the walls. Turf walls have lower electrical conductivity compared with the surrounding soil, probably as a result of different porosities. The mapping of Rayleigh wave resonance clearly revealed the outline of the ruin, as indicated by weaker amplitudes compared with the surrounding soil. Overall the results indicate that geophysical methods can be used for subsurface mapping of Icelandic turf structures and that the combined application of the methods maximizes this potential. Copyright © 2015 John Wiley & Sons, Ltd.
Autoantigen BiP‐Derived HLA–DR4 Epitopes Differentially Recognized by Effector and Regulatory T Cells in Rheumatoid Arthritis
Authors: Shoda Hirofumi , Fujio Keishi , Sakurai Keiichi , Ishigaki Kazuyoshi , Nagafuchi Yasuo , Shibuya Mihoko , Sumitomo Shuji , Okamura Tomohisa , Yamamoto Kazuhiko
Published: March 2015

Objective

The balance between effector and regulatory CD4+ T cells plays a key role in the pathogenesis of rheumatoid arthritis (RA). The aim of this study was to examine whether the RA autoantigen BiP has epitopes for both effector and regulatory immunities.

Methods

The proliferation and cytokine secretion of peripheral blood mononuclear cells (PBMCs) from HLA–DR4–positive RA patients in response to BiP‐derived peptides were examined by 3H‐thymidine uptake and enzyme‐linked immunosorbent assay. As a mouse therapeutic model, a BiP‐derived peptide was administered orally to mice with collagen‐induced arthritis (CIA).

Results

Among the peptides examined, BiP336–355 induced the strongest proliferation of PBMCs from RA patients, but not from healthy donors. The proliferation of PBMCs in response to BiP336–355 showed a correlation with clinical RA activity and serum anti‐BiP/citrullinated BiP antibodies. In contrast, BiP456–475 induced interleukin‐10 (IL‐10) secretion from CD25‐positive PBMCs obtained from RA patients and healthy donors without inducing cell proliferation, and it actively suppressed the BiP336–355–induced proliferation and proinflammatory cytokine secretion by PBMCs. Oral administration of BiP456–475 to mice with CIA reduced the severity of arthritis and T cell proliferation and increased the secretion of IL‐10 from T cells as well as the number of CD4+CD25+FoxP3+ regulatory T cells.

Conclusion

Effector and regulatory T cells recognized different BiP epitopes. The deviated balance toward BiP‐specific effector T cells in RA may be associated with disease activity; therefore, BiP‐specific effector or regulatory T cells could be a target of new RA therapies.
Nested Case–Control Study of Selected Systemic Autoimmune Diseases in World Trade Center Rescue/Recovery Workers
Authors: Webber M. P. , Moir W. , Zeig‐Owens R. , Glaser M. S. , Jaber N. , Hall C. , Berman J. , Qayyum B. , Loupasakis K. , Kelly K. , Prezant D. J.
Published: March 2015

Objective

To test the a priori hypothesis that acute and chronic work exposures to the World Trade Center (WTC) site on or after September 11, 2001 were associated with risk of new‐onset systemic autoimmune diseases.

Methods

A nested case–control study was performed in WTC rescue/recovery workers who had received a rheumatologist‐confirmed systemic autoimmune disease diagnosis between September 12, 2001 and September 11, 2013 (n = 59), each of whom was individually matched to 4 randomly selected controls (n = 236) on the basis of year of hire (±1 year), sex, race, and work assignment (firefighter or emergency medical service). Acute exposure was defined according to the earliest time of arrival (morning of 9/11 versus later) at the WTC site, and chronic exposure was defined as duration (number of months) of WTC site–related work. Rheumatologists were blinded with regard to each subject's exposure status. The conditional odds ratios (CORs) with 95% confidence intervals (95% CIs) for incident autoimmune disease were derived from exact conditional logistic regression models.

Results

Rheumatoid arthritis was the most common autoimmune diagnosis (37% of subjects), followed by spondyloarthritis (22%), inflammatory myositis (14%), systemic lupus erythematosus (12%), systemic sclerosis (5%), Sjögren's syndrome (5%), antiphospholipid syndrome (3%), and granulomatosis with polyangiitis (Wegener's) (2%). The COR for incident autoimmune disease increased by 13% (COR 1.13, 95% CI 1.02–1.26) for each additional month worked at the WTC site. These odds were independent of the association between high acute exposure (working during the morning of 9/11) and disease outcome, which conveyed an elevated, but not statistically significant, risk (COR 1.85, 95% CI 0.86–3.89).

Conclusion

Prolonged work at the WTC site, independent of acute exposure, was an important predictor of post‐9/11 systemic autoimmune diseases. The WTC Health Program should expand surveillance efforts for those with extended exposures, as early detection can facilitate early treatment, which has been shown to minimize organ damage and improve quality of life.
Interleukin‐1 Acts via the JNK‐2 Signaling Pathway to Induce Aggrecan Degradation by Human Chondrocytes
Authors: Ismail Heba M. , Yamamoto Kazuhiro , Vincent Tonia L. , Nagase Hideaki , Troeberg Linda , Saklatvala Jeremy
Published: March 2015

Objective

Aggrecan enables articular cartilage to bear load and resist compression. Aggrecan loss occurs early in osteoarthritis and rheumatoid arthritis and can be induced by inflammatory cytokines such as interleukin‐1 (IL‐1). IL‐1 induces cleavage of specific aggrecans characteristic of the ADAMTS proteinases. The aim of this study was to identify the intracellular signaling pathways by which IL‐1 causes aggrecan degradation by human chondrocytes and to investigate how aggrecanase activity is controlled by chondrocytes.

Methods

We developed a cell‐based assay combining small interfering RNA (siRNA)–induced knockdown with aggrecan degradation assays. Human articular chondrocytes were overlaid with bovine aggrecan after transfection with siRNAs against molecules of the IL‐1 signaling pathway. After IL‐1 stimulation, released aggrecan fragments were detected with AGEG and ARGS neoepitope antibodies. Aggrecanase activity and tissue inhibitor of metalloproteinases 3 levels were measured by enzyme‐linked immunosorbent assay. Low‐density lipoprotein receptor–related protein 1 (LRP‐1) shedding was analyzed by Western blotting.

Results

ADAMTS‐5 is a major aggrecanase in human chondrocytes, regulating aggrecan degradation in response to IL‐1. The tumor necrosis factor receptor–associated 6 (TRAF‐6)/transforming growth factor β–activated kinase 1 (TAK‐1)/MKK‐4 signaling axis is essential for IL‐1–induced aggrecan degradation, while NF‐κB is not. Of the 3 MAPKs (ERK, p38, and JNK), only JNK‐2 showed a significant role in aggrecan degradation. Chondrocytes constitutively secreted aggrecanase, which was continuously endocytosed by LRP‐1, keeping the extracellular level of aggrecanase low. IL‐1 induced aggrecanase activity in the medium in a JNK‐2–dependent manner, possibly by reducing aggrecanase endocytosis, because IL‐1 caused JNK‐2–dependent shedding of LRP‐1.

Conclusion

The signaling axis TRAF‐6/TAK‐1/MKK‐4/JNK‐2 mediates IL‐1–induced aggrecanolysis. The level of aggrecanase is controlled by its endocytosis, which may be reduced upon IL‐1 stimulation because of LRP‐1 shedding.
Suppression of Autoimmunity and Renal Disease in Pristane‐Induced Lupus by Myeloperoxidase
Authors: Odobasic Dragana , Muljadi Ruth C. M. , O'Sullivan Kim M. , Kettle Anthony J. , Dickerhof Nina , Summers Shaun A. , Kitching A. Richard , Holdsworth Stephen R.
Published: March 2015

Objective

Myeloperoxidase (MPO) locally contributes to organ damage in various chronic inflammatory conditions by generating reactive intermediates. The contribution of MPO in the development of experimental lupus is unknown. The aim of this study was to define the role of MPO in murine lupus nephritis (LN).

Methods

LN was induced in C57BL/6 wild‐type (WT) and MPO knockout (MPO–/–) mice by intraperitoneal injection of pristane. Autoimmunity and glomerulonephritis were assessed 20 and 40 weeks after pristane administration. Cell apoptosis, leukocyte accumulation, and cytokine levels in the peritoneal cavity of WT and MPO–/– mice were assessed 3 or 6 days after pristane injection.

Results

MPO–/– mice developed more severe nephritis than did WT mice 20 and 40 weeks after pristane injection, despite having reduced glomerular deposition of antibody and complement and diminished levels of markers of oxidative stress (oxidized DNA and glutathione sulfonamide). Enhancement of renal disease in MPO‐deficient mice correlated with increased accumulation of CD4+ T cells and macrophages in glomeruli, which, in turn, was associated with augmented generation of CD4+ T cell responses and increased activation and migration of dendritic cells in secondary lymphoid organs. In addition, the enhanced renal injury in MPO–/– mice was associated with increased glomerular accumulation of neutrophils and deposition of neutrophil extracellular traps. MPO deficiency also increased early cell apoptosis, leukocyte accumulation, and proinflammatory cytokine expression in the peritoneum.

Conclusion

MPO attenuates pristane‐induced LN by inhibiting early inflammatory responses in the peritoneum and limiting the generation of CD4+ T cell autoimmunity in secondary lymphoid organs.
Hip Osteoarthritis and the Risk of All‐Cause and Disease‐Specific Mortality in Older Women: A Population‐Based Cohort Study
Authors: Barbour Kamil E. , Lui Li‐Yung , Nevitt Michael C. , Murphy Louise B. , Helmick Charles G. , Theis Kristina A. , Hochberg Marc C. , Lane Nancy E. , Hootman Jennifer M. , Cauley Jane A. ,   for the Study of Osteoporotic Fractures Research Group
Published: March 2015

Objective

To determine the risk of all‐cause and disease‐specific mortality among older women with hip osteoarthritis (OA) and to identify mediators in the causal pathway.

Methods

Data were from the Study of Osteoporotic Fractures, a US population‐based cohort study of 9,704 white women age ≥65 years. The analytic sample included women with hip radiographs at baseline (n = 7,889) and year 8 (n = 5,749). Mortality was confirmed through October 2013 by death certificates and hospital discharge summaries. Radiographic hip OA (RHOA) was defined as a Croft grade of ≥2 in at least 1 hip (definite joint space narrowing or osteophytes plus 1 other radiographic feature).

Results

The mean ± SD followup time was 16.1 ± 6.2 years. The baseline and year 8 prevalence of RHOA were 8.0% and 11.0%, respectively. The cumulative incidence (proportion of deaths during the study period) was 67.7% for all‐cause mortality, 26.3% for cardiovascular disease (CVD) mortality, 11.7% for cancer mortality, 1.9% for gastrointestinal disease mortality, and 27.8% for all other mortality causes. RHOA was associated with an increased risk of all‐cause mortality (hazard ratio 1.14 [95% confidence interval 1.05–1.24]) and CVD mortality (hazard ratio 1.24 [95% confidence interval 1.09–1.41]) adjusted for age, body mass index, education, smoking, health status, diabetes, and stroke. These associations were partially explained by the mediating variable of physical function.

Conclusion

RHOA was associated with an increased risk of all‐cause and CVD mortality among older white women followed up for 16 years. Dissemination of evidence‐based physical activity and self‐management interventions for hip OA in community and clinical settings can improve physical function and might also contribute to lower mortality.
Role of EFNB1 and EFNB2 in Mouse Collagen‐Induced Arthritis and Human Rheumatoid Arthritis
Authors: Hu Yan , Wang Xuehai , Wu Yongqiang , Jin Wei , Cheng Baoli , Fang Xiangming , Martel‐Pelletier Johanne , Kapoor Mohit , Peng Junzheng , Qi Shijie , Shi Guixiu , Wu Jiangping , Luo Hongyu
Published: March 2015

Objective

EFNB1 and EFNB2 are ligands for Eph receptor tyrosine kinases. This study was undertaken to investigate how the expression of Efnb1 and Efnb2 on murine T cells influences the pathogenesis of collagen‐induced arthritis (CIA) and to assess correlations between the T cell expression of these 2 molecules and measures of disease activity in patients with rheumatoid arthritis (RA).

Methods

CIA was studied in mice with T cell–specific deletion (double gene knockout [dKO]) of both Efnb1 and Efnb2. Expression of EFNB1 and EFNB2 messenger RNA (mRNA) in peripheral blood T cells from patients with RA was determined by quantitative reverse transcription– polymerase chain reaction.

Results

In dKO mice, clinical scores of arthritis were reduced compared to those in wild‐type (WT) control mice. Serum collagen‐specific antibody titers in dKO mice were lower than those in WT mice. In analyses based on equal cell numbers, dKO mouse T cells, as compared to WT mouse T cells, provided vastly inferior help to B cells in the production of collagen‐specific antibodies in vitro. T cells from dKO mice were compromised in their ability to migrate to the arthritic paws in vivo and in their ability to undergo chemotaxis toward CXCL12 in vitro. Deletion mutation of Efnb1 and Efnb2 intracellular tails revealed critical regions in controlling T cell chemotaxis. T cells from RA patients expressed higher EFNB1 mRNA levels, which correlated with RA symptoms and laboratory findings.

Conclusion

Efnb1 and Efnb2 in T cells are essential for pathogenic antibody production and for T cell migration to the inflamed paws in mice with CIA. These findings suggest that the expression of EFNB1 in T cells might be a useful parameter for monitoring RA disease activity and treatment responses.