bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modifications of the quasi‐biennial oscillation by a geoengineering perturbation of the stratospheric aerosol layer
Authors: Aquila V. , Garfinkel C. I. , Newman P.A. , Oman L.D. , Waugh D.W. 
Published: January 2014

AbstractThis paper examines the impact of geoengineering via stratospheric sulfate aerosol on the quasi‐biennial oscillation (QBO) using the NASA Goddard Earth Observing System version 5 Chemistry Climate Model. We performed four 30 year simulations with a continuous injection of sulfur dioxide on the equator at 0° longitude. The four simulations differ by the amount of sulfur dioxide injected (5 Tg/yr and 2.5 Tg/yr) and the altitude of the injection (16 km–25 km and 22 km–25 km). We find that such an injection dramatically alters the quasi‐biennial oscillation, prolonging the phase of easterly shear with respect to the control simulation. This is caused by the increased aerosol heating and associated warming in the tropical lower stratosphere and higher residual vertical velocity. In the case of maximum perturbation, i.e., highest stratospheric aerosol burden, the lower tropical stratosphere is locked into a permanent westerly QBO phase.
Wave activity at ionospheric heights above the Andes Mountains detected from FORMOSAT‐3/COSMIC GPS radio occultation data
Authors: de la Torre A. , Alexander P. , Llamedo P. , Hierro R. , Nava B. , Radicella S. , Schmidt T. , Wickert J. 
Published: January 2014

AbstractAn estimation of the ionospheric wave activity, derived from 4 years of FORMOSAT‐3/ COSMIC GPS (Taiwan's Formosa Satellite Mission 3/Constellation Observing System for Meteorology—Global Positioning System) radio occultation electron density data, is presented. A systematic enhancement at the eastern side of the Andes range with respect to the western side is observed. A fitting method to remove the wavelike component from each measured profile and estimate the wave activity is described. The differential effect introduced by the action of orography on the generation, to the eastern side of the Andes, of mountain waves, deep convection waves, or even secondary waves aloft after momentum deposition in the middle atmosphere, is suggested.
Detailed modeling and analysis of spacecraft plume/ionosphere interactions in low Earth orbit
Authors: Stephani K. A. , Boyd I. D. 
Published: January 2014

AbstractDetailed direct simulation Monte Carlo/particle‐in‐cell simulations involving the interaction of spacecraft thruster plumes with the rarefied ambient ionosphere are presented for steady thruster firings in low Earth orbit (LEO). A nominal mass flow rate is used to prescribe the rocket exit conditions of a neutral propellant species for use in the simulations. The charge exchange interactions of the steady plume with the rarefied ionosphere are modeled using a direct simulation Monte Carlo/particle‐in‐cell methodology, allowing for a detailed assessment of nonequilibrium collisional and plasma‐related phenomena relevant for these conditions. Results are presented for both ram‐ and wake‐flow configurations, in which the thrusters are firing into (ram) or in the direction of (wake) the free stream ionosphere flow in LEO. The influence of the Earth's magnetic field on the development of the ion plume is also examined for three different field strengths: two limiting cases in whichB→0 andB→∞, and the LEO case in whichB=0.5 Gs. The magnetic field is found to have a substantial impact on the resulting neutral and ion plumes, and the gyroscopic motion of the magnetized ions results in a broadening of the ion energy distribution functions. The magnetic field model also incorporates a cross‐field diffusion mechanism which is shown to increase the current density sampled far from the thruster.
Altitude variations in the thermosphere mass density response to geomagnetic activity during the recent solar minimum
Authors: Liu X. , Thayer J. P. , Burns A. , Wang W. , Sutton E. 
Published: January 2014

AbstractAccelerometer data from coplanar orbits of Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites were used to study the complex altitude and latitude variations of the thermosphere mass density response to geomagnetic activity during 1–10 December 2008 near 09 LT. Helium number densities near 500 km altitude were extracted from the CHAMP and GRACE measurements and clearly show the presence of a winter hemisphere helium bulge. This recent extreme solar minimum indicates that wintertime helium concentrations exceed NRLMSISE‐00 model estimates by 30%–70% during quiet geomagnetic activity after adjusting F10.7 input into MSIS. The perturbation in mass density from quiet to active conditions is found to be less enhanced in the winter hemisphere at the higher GRACE altitudes (25%) than at the lower CHAMP altitudes (60%) and is attributed to dynamic behavior in the helium/oxygen transition. The investigation revealed the maximum storm time density perturbation to occur near the He/O transition region with a much weaker maximum near the O/N2 transition region. The altitude of maximum density perturbation occurs where the perturbation in the weighted pressure scale height is equal and opposite to the perturbation in the weighted mean molecular weight scale height. The altitude structure of density scale height perturbation is significantly influenced by the changes in the molecular weight scale height and can account for 50% of the change in mass density scale height in a region correspondingly close to the He/O transition during the 2008 solar minimum period.
Understanding Preferences for Disease‐Modifying Drugs in Osteoarthritis
Authors: Fraenkel Liana , Suter Lisa , Cunningham Charles E. , Hawker Gillian 
Published: January 2014

ObjectiveNumerous disease‐modifying drugs for osteoarthritis (DMOADs) are under investigation. However, patients' preferences for drugs to prevent progression of OA are not known. The objective of this study was to quantify patient preferences for potential DMOADs.MethodsWe administered a conjoint analysis survey to 304 patients attending outpatient general medicine and specialty clinics. All patients seated in the waiting rooms were asked if they would participate in a survey to elicit opinions about arthritis treatments. We performed simulations to estimate preferences for 4 options to prevent worsening of knee OA: best case (pill, highest benefit, lowest risk, lowest cost), worst case (infusion, lowest benefit, highest risk, highest cost), moderate subcutaneous injection (injection, mid‐level benefit, mid‐level risk, mid‐level cost), and moderate infusion (same as subcutaneous injection except administered by infusion).ResultsSubjects' median age was 57 years; 55% were women and 76% were white. Segmentation analyses revealed 4 patterns of preferences. A minority (5%) did not want to perform subcutaneous injections and would only consider DMOADs under the best‐case scenario. Approximately 20% were risk sensitive and were willing to take DMOADs under the best‐case scenario, but would start rejecting these medications as risk increased. A significant number rejected DMOADs under all conditions (16.4%); however, the largest segment (59.2%) had a strong preference for DMOADs across all scenarios.ConclusionOur results suggest that a significant percentage of a nonselected outpatient population might be willing to accept at least a moderate degree of risk in order to prevent worsening knee OA.
Risk of Hospitalized Bacterial Infections Associated With Biologic Treatment Among US Veterans With Rheumatoid Arthritis
Authors: Curtis J. R. , Yang S. , Patkar N. M. , Chen L. , Singh J. A. , Cannon G. W. , Mikuls T. R. , Delzell E. , Saag K. G. , Safford M. M. , DuVall S. , Alexander K. , Napalkov P. , Winthrop Kevin L. , Burton M. J. , Kamauu A. , Baddley J. W. 
Published: January 2014

ObjectiveThe comparative risk of infection associated with non–anti–tumor necrosis factor (anti‐TNF) biologic agents is not well established. Our objective was to compare risk for hospitalized infections between anti‐TNF and non–anti‐TNF biologic agents in US veterans with rheumatoid arthritis (RA).MethodsUsing 1998–2011 data from the US Veterans Health Administration, we studied RA patients initiating rituximab, abatacept, or anti‐TNF therapy. Exposure was based upon days supplied (injections) or usual dosing intervals (infusions). Treatment episodes were defined as new biologic agent use. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for hospitalization for a bacterial infection were estimated from Cox proportional hazards models, adjusting for potential confounders.ResultsAmong 3,152 unique RA patients contributing 4,158 biologic treatment episodes to rituximab (n = 596), abatacept (n = 451), and anti‐TNF agents (n = 3,111), the patient mean age was 60 years and 87% were male. The most common infections were pneumonia (37%), skin/soft tissue (22%), urinary tract (9%), and bacteremia/sepsis (7%). Hospitalized infection rates per 100 person‐years were 4.4 (95% CI 3.1–6.4) for rituximab, 2.8 (95% CI 1.7–4.7) for abatacept, and 3.0 (95% CI 2.5–3.5) for anti‐TNF. Compared to etanercept, the adjusted rate of hospitalized infection was not different for adalimumab (HR 1.4, 95% CI 0.9–2.2), abatacept (HR 1.1, 95% CI 0.6–2.1), or rituximab (HR 1.4, 0.8–2.6), although it was increased for infliximab (HR 2.3, 95% CI 1.3–4.0). Infection risk was greater for those taking prednisone >7.5 mg/day (HR 1.8, 95% CI 1.3–2.7) and in the highest quartile of C‐reactive protein (HR 2.3, 95% CI 1.4–3.8) and erythrocyte sedimentation rate (HR 4.1, 95% CI 2.3–7.2) compared to the lowest quartile.ConclusionIn older, predominantly male US veterans with RA, the risk of hospitalized bacterial infections associated with rituximab or abatacept was similar to etanercept.
Effect of Hydroxychloroquine on Insulin Sensitivity and Lipid Parameters in Rheumatoid Arthritis Patients Without Diabetes Mellitus: A Randomized, Blinded Crossover Trial
Authors: Solomon Daniel H. , Garg Rajesh , Lu Bing , Todd Derrick J. , Mercer Emileigh , Norton Tabatha , Massarotti Elena 
Published: January 2014

ObjectiveObservational studies suggest that hydroxychloroquine (HCQ) may reduce the risk of developing diabetes mellitus in patients with rheumatoid arthritis (RA). We examined the effect of HCQ on insulin resistance in subjects without diabetes mellitus with stable RA.MethodsTwenty‐three RA subjects not currently using HCQ completed a 16‐week, double‐blind crossover study. Subjects were randomly allocated to receive HCQ (6.5 mg/kg/day) or placebo for the first 8 weeks, followed by crossover to the other arm for the final 8 weeks. Subjects underwent oral glucose tolerance testing and fasting lipid measurements at baseline, 8 weeks, and 16 weeks. The change ± SD from baseline in insulin sensitivity index (ISI), homeostatic model assessment for insulin resistance (HOMA‐IR), and lipid parameters were compared between placebo and HCQ using linear regression.ResultsThe mean patient age was 56 years, with 96% women, and the median body mass index was 26.0 kg/m2. After 8 weeks of HCQ, the mean ± SD ISI increase was 0.4 ± 2.9 compared with a small increase during placebo of 0.14 ± 3.1 (adjusted P = 0.785), and the mean ± SD HOMA‐IR decrease was 0.3 ± 1.5 during HCQ versus a decrease of 0.42 ± 1.4 during placebo (adjusted P = 0.308). Small decreases in total cholesterol (12.7 mg/dl) and low‐density lipoprotein (LDL) cholesterol (12.4 mg/dl) were observed during the HCQ treatment periods (both adjusted P < 0.05 compared to placebo).ConclusionHCQ use for 8 weeks in patients without diabetes mellitus with stable RA produced no significant change in insulin resistance. We observed small and statistically significant improvements in total and LDL cholesterol during HCQ treatment.
Predictors of Stopping and Starting Disease‐Modifying Antirheumatic Drugs for Rheumatoid Arthritis
Authors: Solomon Daniel H. , Tonner Chris , Lu Bing , Kim Seoyoung C. , Ayanian John Z. , Brookhart M. Alan , Katz Jeffrey N. , Yelin Ed 
Published: January 2014

ObjectiveDisease‐modifying antirheumatic drugs (DMARDs) are the standard of care for rheumatoid arthritis (RA); however, studies have found that many patients do not receive them. We examined predictors of starting and stopping DMARDs among a longitudinal cohort of patients with RA.MethodsStudy participants came from a cohort of RA patients recruited from a random sample of rheumatologists' practices in Northern California. We examined patterns and predictors of stopping and starting nonbiologic and biologic DMARDs during 1982–2009 based on annual questionnaires. Stopping was defined as stopping all DMARDs and starting was defined as transitioning from no DMARDs to any DMARDs across 2 consecutive years.ResultsThe analysis of starting DMARDs included 471 subjects with 1,974 pairs of years with no DMARD use in the first of 2 consecutive years. From this population, subjects started DMARD use by year 2 in 313 (15.9%) of the pairs. The analysis of stopping DMARDs included 1,026 subjects with 7,595 pairs of years with DMARD use in the first of 2 consecutive years; in 423 pairs (5.6%), subjects stopped DMARD use by year 2. In models that adjusted for RA‐related factors, sociodemographics, and comorbidities, significant predictors of starting DMARDs included younger age, Hispanic ethnicity, shorter disease duration, and the use of oral glucocorticoids. In separate adjusted models, predictors of stopping DMARDs included Hispanic ethnicity and low income, while younger age was associated with a reduced risk of stopping.ConclusionEfforts to improve DMARD use should focus on patient age, ethnicity, and income and RA‐related factors.
Relationship Between Mental Health and Foot Pain
Authors: Butterworth Paul A. , Urquhart Donna M. , Cicuttini Flavia M. , Menz Hylton B. , Strauss Boyd J. , Proietto Joseph , Dixon John B. , Jones Graeme , Wluka Anita E. 
Published: January 2014

ObjectiveAlthough mental health is related to the persistence of musculoskeletal pain, our understanding of the relationship between mental health and foot pain is limited. Subsequently, we conducted a 3‐year longitudinal study to examine the relationship between mental health and foot pain in a community‐based population.MethodsEighty‐three community‐dwelling participants (mean ± SD body mass index [BMI] 35.3 ± 9.0 kg/m2) who had foot pain at study inception in 2008 and for whom measures of mental health (Short Form 36 [SF‐36] health survey mental component summary [MCS]) were available, were invited to take part in this followup study in 2011. Change in foot pain was determined by the difference between the Manchester Foot Pain and Disability Index score at baseline and followup; therefore, a decrease in the score indicated improved foot pain and an increase indicated deterioration in foot pain. Linear regression was used to determine the factors affecting change in foot pain.ResultsOf the 62 respondents (75% response rate, 49 women and 13 men), there were 27 (44%) whose foot pain deteriorated. A higher MCS score of the SF‐36 health survey at baseline was associated with a slower progression of foot pain (β coefficient −0.29, 95% confidence interval −0.42, −0.01), adjusted for age, sex, BMI, and physical health.ConclusionMental health is associated with changes in foot pain. Clinicians dealing with this population should consider the contribution of mental health in their management and treatment of foot pain.
Race and Sex Differences in Willingness to Undergo Total Joint Replacement: The Johnston County Osteoarthritis Project
Authors: Allen Kelli D. , Golightly Yvonne M. , Callahan Leigh F. , Helmick Charles G. , Ibrahim Said A. , Kwoh C. Kent , Renner Jordan B. , Jordan Joanne M. 
Published: January 2014

ObjectiveUsing data from the community‐based Johnston County Osteoarthritis Project, we examined race and sex variations in willingness to undergo, and perceptions regarding, total joint replacement (TJR).MethodsAnalyses were conducted for the total sample who participated in a followup measurement period from 2006–2010 (n = 1,522) and a subsample with symptomatic hip and/or knee osteoarthritis (sOA; n = 445). Participants indicated how willing they would be to have TJR (hip or knee) if their doctor recommended it; responses were categorized as “definitely” or “probably” willing versus “unsure,” “probably not,” or “definitely not” willing, or “don't know.” Participants answered 7 questions regarding perceptions of TJR outcomes. Multivariable logistic regression models of willingness included participant characteristics (including socioeconomic status) and TJR perception variables that were associated with willingness at the P < 0.1 level in bivariate analyses.ResultsAfrican Americans had lower odds of willingness to undergo TJR than whites in the total sample (adjusted odds ratio [OR] 0.47 [95% confidence interval (95% CI) 0.31–0.72]) and the sOA subsample (adjusted OR 0.42 [95% CI 0.25–0.69]). There were no sex differences in willingness. African Americans expected poorer TJR outcomes than whites, but sex differences were minimal; perceptions of TJR outcomes were not significantly associated with willingness.ConclusionIn this community sample, race differences in TJR willingness and perceptions were substantial, but sex differences were small. Perceptions of TJR did not appear to affect willingness or explain race differences in willingness.
Tuning the Charge‐Transport Property of Pyromellitic Diimide‐Based Conjugated Polymers towards Efficient Field‐Effect Transistors
Authors: Zhou Xu , Cao Yue , Wang Xiao‐Ye , Guo Zi‐Hao , Wang Jie‐Yu , Pei Jian 
Published: January 2014

AbstractOrganic field‐effect transistors have received increased attention because of their unique properties such as low cost and large‐area production. Among the organic field‐effect transistors, donor‐π‐acceptor (D‐A) conjugated polymers show outstanding advantages such as material design flexibility and solution processability. Herein, a series of pyromellitic diimide‐based donor‐acceptor conjugated polymers (PPMDI‐nT) with different donor/acceptor ratios were developed. Their photophysical and electrochemical properties were fully investigated. Furthermore, the organic field‐effect transistors based on PPMDI‐nT were fabricated through a solution process. PPMDI‐1T is an n‐type semiconductor, whereas the other polymers exhibit typical ambipolar transport behaviors. As the donor/acceptor ratios increased, the electron mobilities stayed almost the same, but the hole mobilities increased dramatically. Thus the charge‐transport properties of these polymers could be tuned accordingly.
Prevalence of allergic diseases in Izmir Province, Turkey
Authors: Köse Şükran , Mandıracıoğlu Aliye , Çavdar Gülsün , Ulu Yıldız , Senger Süheyla Serin 
Published: January 2014

BackgroundThe aim of the present study is to determine the prevalence of allergic diseases and related risk factors in Izmir, Turkey, and to assess the positive immunoglobulin E (IgE) levels against common allergens.MethodsThe questionnaires were completed via face‐to‐face interview with a total of 2937 individuals. Specific IgE was studied in the serum samples by enzyme‐linked immunosorbent assay (ELISA). This cross‐sectional population‐based study comprised adolescents over the age of 15 years and adults of Izmir province.ResultsIn Izmir, the prevalence of self‐reported allergy was 35.5%. Allergy was statistically significantly more common in females, university graduates, in those with high income, with family history for allergy, aged 40–49 years, those living in a flat, keeping pet(s), and in those using central heating. The prevalence of atopy according to the serum IgE levels (Class 3 with any of 3 IgEs) was found 1.6%.ConclusionIn conclusion, the prevalence of atopy was found lower in Izmir as compared to the results of other studies.
α‐Oligofurane: eine aufstrebende Klasse konjugierter Oligomere für die organische Elektronik
Authors: Gidron Ori , Bendikov Michael 
Published: January 2014

AbstractObwohl sich der Bereich der organischen Elektronik im Laufe der letzten Jahre erheblich weiterentwickelt hat, wird er noch immer durch die Zahl verfügbarer Materialien beschränkt. Ein weiterer Ausbau erfordert die Einführung neuartiger π‐konjugierter Rückgrate, geeignete Kandidaten hierfür werden aber nur sehr selten entdeckt. Die Einführung einer neuen Klasse konjugierter Materialien – der langen α‐Oligofurane – wurde daher vor kurzem mit großem Interesse begrüßt. α‐Oligofurane weisen viele Eigenschaften auf, die für Anwendungen in organischen elektronischen Materialien erforderlich sind, und sollen biologisch abbaubar sein. Dieser Kurzaufsatz bietet eine Beschreibung langer Oligofurane aus der Perspektive ihrer Synthese, molekularen Eigenschaften, chemischen Reaktivität und Verwendung in elektronischen Bauelementen.
Chemosensorische Ensembles zur Echtzeitdetektion von Transportprozessen durch Biomembranen
Authors: Ghale Garima , Lanctôt Adrienne G. , Kreissl Hannah T. , Jacob Maik H. , Weingart Helge , Winterhalter Mathias , Nau Werner M. 
Published: January 2014

AbstractDie Effektivität von Wirkstoffen und Biomolekülen basiert auf ihrer Fähigkeit, die Lipidmembran zu passieren. Die Entwicklung von Methoden, diese Transportprozesse direkt und mit hoher Empfindlichkeit zu verfolgen, bleibt eine Herausforderung. Der Einschluss eines chemosensorischen Ensembles, bestehend aus einem makrocyclischen Wirt (p‐Sulfonatocalix[4]aren oder Cucurbit[7]uril) und einem Fluoreszenzfarbstoff (Lucigenin oder Berberin) in Liposomen ermöglicht es, den Membrandurchtritt von unmarkierten bioorganischen Molekülen direkt und in Echtzeit mittels Fluoreszenz zu verfolgen. Dieser In‐vitro‐Assay kann auf unterschiedliche Kanalproteine und Analyten angewendet werden, eignet sich zur schnellen Charakterisierung von Kanalmodulatoren und liefert zudem die absolute Kinetik der Translokation. Mit dieser neuen biophysikalischen Methode konnten wir erstmalig die direkte schnelle Translokation des antibiotisch wirksamen Peptids Protamin durch das bakterielle Transmembranprotein OmpF nachweisen.
Tung oil‐based thermosetting polymers for self‐healing applications
Authors: Hondred Peter R. , Salat Leo , Mangler Josh , Kessler Michael R. 
Published: January 2014

ABSTRACTSeveral bio‐renewable thermosetting polymers were successfully prepared from tung oil through cationic polymerization for the use as the healing agent in self‐healing microencapsulated applications. The tung oil triglyceride was blended with its methyl ester, which was produced by saponification followed by esterification. The changes in storage modulus, loss modulus, and glass transition temperature as functions of the methyl ester content were measured using dynamic mechanical analysis. In addition, the fraction of cross‐linked material in the polymer was calculated by Soxhlet extraction, while proton nuclear magnetic resonance, Fourier transform infrared spectroscopy and TEM were used to investigate the structure of the copolymer networks. The thermal stability of the thermosets as a function of their methyl ester blend contents was determined by thermogravimetric analysis. Finally, the adhesive properties of the thermosets were studied using compressive lap shear and the fracture surfaces were analyzed using SEM. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40406.