bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical processes contributing to an ice free Beaufort Sea during September 2012
Authors: Babb D. G. , Galley R. J. , Barber D. G. , Rysgaard S. 
Published: December 2015

AbstractDuring the record September 2012 sea ice minimum, the Beaufort Sea became ice free for the first time during the observational record. Increased dynamic activity during late winter enabled increased open water and seasonal ice coverage that contributed to negative sea ice anomalies and positive solar absorption anomalies which drove rapid bottom melt and sea ice loss. As had happened in the Beaufort Sea during previous years of exceptionally low September sea ice extent, anomalous solar absorption developed during May, increased during June, peaked during July, and persisted into October. However in situ observations from a single floe reveal less than 78% of the energy required for bottom melt during 2012 was available from solar absorption. We show that the 2012 sea ice minimum in the Beaufort was the result of anomalously large solar absorption that was compounded by an arctic cyclone and other sources of heat such as solar transmission, oceanic upwelling, and riverine inputs, but was ultimately made possible through years of preconditioning toward a younger, thinner ice pack. Significant negative trends in sea ice concentration between 1979 and 2012 from June to October, coupled with a tendency toward earlier sea ice reductions have fostered a significant trend of +12.9 MJ m−2 yr−1 in cumulative solar absorption, sufficient to melt an additional 4.3 cm m−2 yr−1. Overall through preconditioning toward a younger, thinner ice pack the Beaufort Sea has become increasingly susceptible to increased sea ice loss that may render it ice free more frequently in coming years.
On the majestic seasonal upwelling system of the Arafura Sea
Authors: Kämpf Jochen 
Published: December 2015

AbstractA three‐dimensional hydrodynamic model is applied to explore the development of phytoplankton blooms in the Arafura Sea during the southeast monsoon (June–November). Before this season, blooms are restricted to nearshore waters covering a total area of ∼25,000 km2. Satellite data indicate that the bloom area grows substantially to >90,000 km2 during the southeast monsoon covering most of the northwestern Arafura Sea. Findings confirm that the southeast monsoon creates undercurrents via the classical lee effect driving nutrient‐rich Banda Sea slope water into this region. This nutrient‐rich slope water is driven over vast distances (∼300 km) into the northwestern Arafura Sea where it upwells and/or is entrained into the surface mixed layer. The associated overturning circulation is slow but continuous and it takes 1–2 months before nutrient‐rich water appears in surface waters of the region. The predicted pathways of nutrient‐rich inflows across the shelf break both north and south of the Ara Islands agree with observational evidence.
The future of the subsurface chlorophyll‐a maximum in the Canada Basin—A model intercomparison
Authors: Steiner N. S. , Sou T. , Deal C. , Jackson J. M. , Jin M. , Popova E. , Williams W. , Yool A. 
Published: December 2015

AbstractSix Earth system models and three ocean‐ice‐ecosystem models are analyzed to evaluate magnitude and depth of the subsurface Chl‐a maximum (SCM) in the Canada Basin and ratio of surface to subsurface Chl‐a in a future climate scenario. Differences in simulated Chl‐a are caused by large intermodel differences in available nitrate in the Arctic Ocean and to some extent by ecosystem complexity. Most models reproduce the observed SCM and nitracline deepening and indicate a continued deepening in the future until the models reach a new state with seasonal ice‐free waters. Models not representing a SCM show either too much nitrate and hence no surface limitation or too little nitrate with limited surface growth only. The models suggest that suppression of the nitracline and deepening of the SCM are caused by enhanced stratification, likely driven by enhanced Ekman convergence and freshwater contributions with primarily large‐scale atmospheric driving mechanisms. The simulated ratio of near‐surface Chl‐a to depth‐integrated Chl‐a is slightly decreasing in most areas of the Arctic Ocean due to enhanced contributions of subsurface Chl‐a. Exceptions are some shelf areas and regions where the continued ice thinning leaves winter ice too thin to provide a barrier to momentum fluxes, allowing winter mixing to break up the strong stratification. Results confirm that algorithms determining vertically integrated Chl‐a from surface Chl‐a need to be tuned to Arctic conditions, but likely require little or no adjustments in the future.
Impact of idealized future stratospheric aerosol injection on the large‐scale ocean and land carbon cycles
Authors: Tjiputra J. F. , Grini A. , Lee H. 
Published: December 2015

AbstractUsing an Earth system model, we simulate stratospheric aerosol injection (SAI) on top of the Representative Concentration Pathways 8.5 future scenario. Our idealized method prescribes aerosol concentration, linearly increasing from 2020 to 2100, and thereafter remaining constant until 2200. In the aggressive scenario, the model projects a cooling trend toward 2100 despite warming that persists in the high latitudes. Following SAI termination in 2100, a rapid global warming of 0.35 K yr−1 is simulated in the subsequent 10 years, and the global mean temperature returns to levels close to the reference state, though roughly 0.5 K cooler. In contrast to earlier findings, we show a weak response in the terrestrial carbon sink during SAI implementation in the 21st century, which we attribute to nitrogen limitation. The SAI increases the land carbon uptake in the temperate forest‐, grassland‐, and shrub‐dominated regions. The resultant lower temperatures lead to a reduction in the heterotrophic respiration rate and increase soil carbon retention. Changes in precipitation patterns are key drivers for variability in vegetation carbon. Upon SAI termination, the level of vegetation carbon storage returns to the reference case, whereas the soil carbon remains high. The ocean absorbs nearly 10% more carbon in the geoengineered simulation than in the reference simulation, leading to a ∼15 ppm lower atmospheric CO2 concentration in 2100. The largest enhancement in uptake occurs in the North Atlantic. In both hemispheres' polar regions, SAI delays the sea ice melting and, consequently, export production remains low. In the deep water of North Atlantic, SAI‐induced circulation changes accelerate the ocean acidification rate and broaden the affected area.
Association of Somatic Comorbidities and Comorbid Depression With Mortality in Patients With Rheumatoid Arthritis: A 14‐Year Prospective Cohort Study
Authors: van den Hoek J. , Boshuizen H. C. , Roorda L. D. , Tijhuis G. J. , Nurmohamed M. T. , Dekker J. , van den Bos G. A. M. 
Published: December 2015

ObjectivePatients with rheumatoid arthritis (RA) have a significantly increased risk of mortality compared with the general population. One of the most important predictors for mortality is somatic comorbidity. Moreover, studies have demonstrated that comorbid depression is associated with mortality. Which specific comorbidities are associated with mortality is less investigated. The purpose of this study was to investigate the association of a wide range of comorbidities with mortality in patients with RA.MethodsLongitudinal data over a 14‐year period were collected from 882 patients with RA. Data were assessed with questionnaires. The mortality status was obtained from the Statistics Netherlands for the period 1996–2011 for 99% of the patients. Somatic comorbidity was assessed in 1997, 1998, 1999, and 2008 and measured by a national population‐based questionnaire including 20 chronic diseases. Comorbid depression was assessed in 1997, 1998, and 1999 and measured with the Center for Epidemiologic Studies Depression Scale. Cox regression was used to study the relationship between comorbidity and mortality.ResultsAt baseline, 72% of the patients were women. The mean ± SD age was 59.3 ± 14.8 years, and the median (interquartile range) disease duration was 5.0 (2.0–14.0) years. A total of 345 patients died during the study period. Comorbidities that were associated with mortality were circulatory conditions (hazard ratio [HR] 1.60 [95% confidence interval (95% CI) 1.15–2.22]), respiratory conditions (HR 1.43 [95% CI 1.09–1.89]), cancer (HR 2.00 [95% CI 1.28–3.12]), and depression (HR 1.35 [95% CI 1.06–1.72]).ConclusionComorbid circulatory conditions, respiratory conditions, cancer, and depression are associated with mortality among patients with RA. Careful monitoring of these comorbidities during the course of the disease and adequate referral may improve health outcomes and chances of surviving.
Using Dermal Temperature to Identify Rheumatoid Arthritis Patients With Radiologic Progressive Disease in Less Than One Minute
Authors: Greenwald Maria , Ball Joann , Guerrettaz Kelly , Paulus Harold 
Published: December 2015

ObjectiveTo explore development of a screening test for rheumatoid arthritis (RA) patients most likely to develop radiographic damage in the next year. The test is a simple, objective measurement of elevated dermal temperature over an inflamed joint in this observational, prospective cohort study.MethodsSeropositive RA patients were sequentially enrolled into cohorts with hot or cool joints, as determined by a dermal thermometer. Patients naive to biologic therapy were maintained on a stable dosage of methotrexate (20–25 mg/week). The hot‐joint cohort had a joint skin temperature greater than their body temperature on vital signs. Hand/wrist radiographs obtained at baseline and 1 year later were read and scored using modified Sharp/van der Heijde scores (SHS) by a single reader without sequence order or identifiers.ResultsEach cohort consisted of 104 patients enrolled into observation between 2009 and 2014. Patients in the cohort with hot joints had a mean ± SD joint temperature of 1.06 ± 0.69°F above central body temperature and a nearly 4‐fold higher risk of new radiographic damage than those with cool joints (SHS score 8.7 ± 6.2 versus 2.5 ± 1.4; P < 0.001). Sensitivity and specificity for joint temperature to predict radiographic damage in the next year were 92% and 78%, respectively, in the hot‐joint cohort. As expected, this cohort at baseline was younger, had more recent onset RA, and had higher Westergren erythrocyte sedimentation rate levels than the cool‐joint cohort (P < 0.001 for each).ConclusionDermal joint temperature may become a screening test to quickly and accurately identify individual RA patients at high risk for radiographic damage and those who may benefit most from biologic therapy.
Ferromagnetism Induced by Substitution of the Iron(IV) Ion by an Unusual High‐Valence Nickel(IV) Ion in Antiferromagnetic SrFeO3
Authors: Seki Hayato , Hosaka Yoshiteru , Saito Takashi , Mizumaki Masaichiro , Shimakawa Yuichi 
Published: December 2015

AbstractNovel cubic perovskites SrFe1−xNixO3 (0≤x≤0.5) with unusual high‐valence iron(IV) and nickel(IV) ions were obtained by high‐pressure and high‐temperature synthesis. Substantial magnetic moments of NiIV, which is intrinsically nonmagnetic with a nominal d6 electron configuration, were induced by the large magnetic moments of FeIV through orbital hybridization with oxygen. As a result, ferromagnetism with the transition temperature (Tc) above room temperature could be induced.
Enantioselektive Katalysatoren zur Synthese von α‐substituierten Allylboronsäureestern – ein effizienter Zugang zu isomerenreinen Homoallylalkoholen
Authors: Brauns Marcus , Muller Frédéric , Gülden Daniel , Böse Dietrich , Frey Wolfgang , Breugst Martin , Pietruszka Jörg 
Published: December 2015

AbstractDie Verwendung einer einfachen Schutzgruppe für Boronsäureester ermöglicht eine selektive katalysierte SN2′‐Reaktion, um Allylboronsäureester zu erzeugen, die zur Synthese von enantiomerenreinen Homoallylalkoholen genutzt werden können. Abhängig von der Konfiguration der Schutzgruppe und der des Katalysators können alle vier möglichen Stereoisomere erhalten werden. Mithilfe von Dichtefunktionalrechnungen wird die Selektivität der Allyladdition erklärt.
The Strongest Acid: Protonation of Carbon Dioxide
Authors: Cummings Steven , Hratchian Hrant P. , Reed Christopher A. 
Published: December 2015

AbstractThe strongest carborane acid, H(CHB11F11), protonates CO2 while traditional mixed Lewis/Brønsted superacids do not. The product is deduced from IR spectroscopy and calculation to be the proton disolvate, H(CO2)2+. The carborane acid H(CHB11F11) is therefore the strongest known acid. The failure of traditional mixed superacids to protonate weak bases such as CO2 can be traced to a competition between the proton and the Lewis acid for the added base. The high protic acidity promised by large absolute values of the Hammett acidity function (H0) is not realized in practice because the basicity of an added base is suppressed by Lewis acid/base adduct formation.
Interrogating Substrate Selectivity and Composition of Endogenous Histone Deacetylase Complexes with Chemical Probes
Authors: Dose Alexander , Sindlinger Julia , Bierlmeier Jan , Bakirbas Ahmet , Schulze‐Osthoff Klaus , Einsele‐Scholz Stephanie , Hartl Markus , Essmann Frank , Finkemeier Iris , Schwarzer Dirk 
Published: December 2015

AbstractHistone deacetylases (HDACs) regulate the function and activity of numerous cellular proteins by removing acetylation marks from regulatory lysine residues. We have developed peptide‐based HDAC probes that contain hydroxamate amino acids of various lengths to replace modified lysine residues in the context of known acetylation sites. The interaction profiles of all human HDACs were studied with three sets of probes, which derived from different acetylation sites, and sequence context was found to have a strong impact on substrate recognition and composition of HDAC complexes. By investigating K382 acetylation of the tumor suppressor p53 as an example, we further demonstrate that the interaction profiles reflect the catalytic activities of respective HDACs. These results underline the utility of the newly established probes for deciphering not only activity, but also substrate selectivity and composition of endogenous HDAC complexes, which can hardly be achieved otherwise.
Metal‐Free Ring‐Expansion Reaction of Six‐membered Sulfonylimines with Diazomethanes: An Approach toward Seven‐Membered Enesulfonamides
Authors: Xia An‐Jie , Kang Tai‐Ran , He Long , Chen Lian‐Mei , Li Wen‐Ting , Yang Jin‐Liang , Liu Quan‐Zhong 
Published: December 2015

AbstractA new metal‐free, ring‐expansion reaction of six‐membered N‐sulfonylimines with unstable diazomethanes, generated in situ from the N‐tosylhydrazones, has been developed. This reaction delivers valuable seven‐membered enesulfonamides by a Tiffeneau–Demjanov rearrangement and intramolecular proton transfer tautomerization process. Moreover, this ring‐expansion reaction can be carried out in a one‐pot fashion and scaled up to the gram scale by using aryl aldehydes, without the need to isolate the N‐tosylhydrazone.
Risk of Incident Diabetes Mellitus Associated With the Dosage and Duration of Oral Glucocorticoid Therapy in Patients With Rheumatoid Arthritis
Authors: Movahedi Mohammad , Beauchamp Marie‐Eve , Abrahamowicz Michal , Ray David W. , Michaud Kaleb , Pedro Sofia , Dixon William G. 
Published: December 2015

ObjectiveTo quantify the risk of incident diabetes mellitus (DM) associated with the dosage, duration, and timing of glucocorticoid (GC) use in patients with rheumatoid arthritis (RA).MethodsWe undertook a cohort study using 2 databases: a UK primary care database (the Clinical Practice Research Datalink [CPRD]) including 21,962 RA patients (1992–2009) and the US National Data Bank for Rheumatic Diseases (NDB) including 12,657 RA patients (1998–2013). Information on the dosage and timing of GC use was extracted. DM in the CPRD was defined using Read codes, at least 2 prescriptions for oral antidiabetic medication, or abnormal blood test results. DM in the NDB was defined through patient self‐reports. Data were analyzed using time‐dependent Cox models and a novel weighted cumulative dose (WCD) model that accounts for dosage, duration, and timing of treatment.ResultsThe hazard ratio (HR) was 1.30 (95% confidence interval [95% CI] 1.17–1.45) and 1.61 (95% CI 1.37–1.89) in current GC users compared to nonusers in the CPRD and the NDB, respectively. A range of conventional statistical models consistently confirmed increases in risk with the GC dosage and duration. The WCD model showed that recent GC use contributed the most to the current risk of DM, while doses taken >6 months previously did not influence current risk. In the CPRD, 5 mg of prednisolone equivalent dose for the last 1, 3, and 6 months was significantly associated with HRs of 1.20, 1.43, and 1.48, respectively, compared to nonusers.ConclusionGC use is a clinically important and quantifiable risk factor for DM. Risk is influenced by the dosage and treatment duration, although only for GC use within the last 6 months.
Identification of a Novel Toll‐like Receptor 7 Endogenous Ligand in Rheumatoid Arthritis Synovial Fluid That Can Provoke Arthritic Joint Inflammation
Authors: Kim Seung‐jae , Chen Zhenlong , Essani Abdul B. , Elshabrawy Hatem A. , Volin Michael V. , Volkov Suncica , Swedler William , Arami Shiva , Sweiss Nadera , Shahrara Shiva 
Published: December 2015

ObjectiveLevels of Toll‐like receptor 7 (TLR‐7) are elevated in rheumatoid arthritis (RA), but the impact on RA is unknown because the endogenous ligand for TLR‐7 has not been identified. The aim of this study was to identify a TLR‐7 endogenous ligand and to determine its role in the pathogenesis of RA.MethodsThe presence of an endogenous TLR‐7 ligand, microRNA let‐7b (miR‐let‐7b), was examined by real‐time polymerase chain reaction (PCR) analysis. Using RA knockdown cells, TLR‐7–knockout mice, or antagonist, the specificity of miR‐let‐7b as a potential ligand for TLR‐7 was tested. The mechanism by which ligation of miR‐let‐7b to TLR‐7 promotes disease was investigated in RA myeloid cells by real‐time PCR, enzyme‐linked immunosorbent assay, and fluorescence‐activated cell sorting. We also established the effect of ectopic miR‐let‐7b expression on arthritic joint inflammation.ResultsWe found that a TLR‐7 endogenous ligand resides mainly in RA synovial fluid macrophages. The GU‐rich domain in miR‐let‐7b was found to be essential for TLR‐7 ligation, since miR‐147, the positive control for GU, was able to stimulate TLR‐7+ myeloid cells, whereas miR‐124, the negative, non‐GU, control, was not. We demonstrated that miR‐let‐7b or exosomes containing miR‐let‐7b could transform the RA and/or mouse naive or antiinflammatory macrophages into inflammatory M1 macrophages via TLR‐7 ligation. Consistently, we showed that miR‐let‐7b provokes arthritis by remodeling naive myeloid cells into M1 macrophages via TLR‐7 ligation, since joint swelling and M1 macrophages are absent in TLR‐7–deficient mice.ConclusionThe results of this study underscore the importance of miR‐let‐7b ligation to TLR‐7 in the joint during the effector phase of RA.
Improving the Performance of Perovskite in Nonaqueous Oxygen Electrocatalysis
Authors: Lu Meihua , Xu Chaohe , Zhan Yi , Lee Jim Yang 
Published: December 2015

AbstractNanoparticle (NP) aggregates of lanthanum cobalt oxide perovskite (LCO) were compounded with reduced graphene oxide (rGO) nanosheets and used as the cathode catalyst for nonaqueous lithium‐oxygen batteries (LOBs). The LCO NP aggregates were completely surrounded by rGO nanosheets in the composite with 10.5 wt % of rGO (LCO‐rGO‐10.5) but were partially exposed in the composite with 7.5 wt % of rGO (LCO‐rGO‐7.5). Both composites performed better than pristine LCO NPs and rGO nanosheets in nonaqueous oxygen electrocatalysis. The LCO‐rGO‐7.5 composite excelled at capacity and rate performance, while the LCO‐rGO‐10.5 composite was better at cycle stability. The good performance of the LCO‐rGO composites was due to the synergy of functions of LCO and rGO.
Clinical, genetic and neuropathological findings in a series of 138 fetuses with a corpus callosum malformation
Authors: Alby Caroline , Malan Valérie , Boutaud Lucile , Marangoni Maria Angela , Bessières Bettina , Bonniere Maryse , Ichkou Amale , Elkhartoufi Nadia , Bahi‐Buisson Nadia , Sonigo Pascale , Millischer Anne‐Elodie , Thomas Sophie , Ville Yves , Vekemans Michel , Encha‐Razavi Férechté , Attié‐Bitach Tania 
Published: December 2015

BACKGROUNDCorpus callosum malformation (CCM) is the most frequent brain malformation observed at birth. Because CCM is a highly heterogeneous condition, the prognosis of fetuses diagnosed prenatally remains uncertain, making prenatal counseling difficult.METHODS AND RESULTSWe evaluated retrospectively a total of 138 fetuses, 117 with CCM observed on prenatal imaging examination, and 21 after postmortem autopsy. On ultrasound and/or magnetic resonance imaging, CCM was either isolated (N = 40) or associated with other neurological (N = 57) or extra cerebral findings (N = 21/20, respectively).RESULTSMost fetuses (N = 132) remained without a diagnosis at the time of pregnancy termination. This emphasizes the need to establish a neuropathological classification and to perform a genomic screening using comparative genomic hybridization. A neuropathological examination performed on 138 cases revealed a spectrum of CCMs, classified as follows: agenesis of corpus callosum (55), CC hypoplasia (30), CC dysmorphism (24), and CCM associated with a malformation of cortical development (29). Of interest, after fetopathological examination, only 16/40 malformations were classified as isolated, highlighting the importance of the autopsy following termination of pregnancy. Among the 138 cases, the underlying etiology was found in 46 cases: diabetes (one case), cytomegalovirus infection (one case), 23 chromosome abnormalities, and 21 mendelian conditions.CONCLUSIONIn our series of 138 cases of CCM, prenatal and postmortem examinations identified a variety of genetic causes. However, no diagnosis could be established in 67% of cases. The classification based on the underlying neurodevelopmental defects paves the way for further genetic studies and genotype‐phenotype correlations. Birth Defects Research (Part A) 106:36–46, 2016. © 2015 Wiley Periodicals, Inc.
Do the cations in clay and the polymer matrix affect quantum dot fluorescent properties?
Authors: Wei Wenjun , Liu Cui , Liu Jiyan , Liu Xueqing , Zou Linling , Cai Shaojun , Shi Hong , Cao Yuan‐Cheng 
Published: December 2015

AbstractThis paper studied the effects of cations and polymer matrix on the fluorescent properties of quantum dots (QDs). The results indicated that temperature has a greater impact on fluorescence intensity than clay cations (mainly K+ and Na+). Combined fluorescence lifetime and steady‐state spectrometer tests showed that QD lifetimes all decreased when the cation concentration was increased, but the quantum yields were steady at various cation concentrations of 0, 0.05, 0.5 and 1 M. Poly(ethylene oxide) (PEO), poly(vinyl alcohol) (PVA) and diepoxy resin were used to study the effects of polymers on QD lifetime and quantum yield. The results showed that the lifetime for QDs 550 nm in PEO and PVA was 17.33 and 17.12 ns, respectively; for the epoxy resin, the lifetime was 0.74 ns, a sharp decrease from 24.47 ns. The quantum yield for QDs 550 nm changed from 34.22% to 7.45% and 7.81% in PEO and PVA, respectively; for the epoxy resin the quantum yield was 2.25%. QDs 580 nm and 620 nm showed the same results as QDs 550 nm. This study provides useful information on the design, synthesis and application of QDs–polymer luminescent materials. Copyright © 2015 John Wiley & Sons, Ltd.