bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue and Factors Related to Fatigue in Rheumatoid Arthritis: A Systematic Review
Authors: Nikolaus Stephanie , Bode Christina , Taal Erik , van de Laar Mart A. F. J. 
Published: January 2013

ObjectiveAlthough patients with rheumatoid arthritis (RA) experience fatigue, little is known about its causes and consequences, and a fully developed theoretical model explaining the experience of fatigue in RA is lacking. Our goal was to systematically review studies in RA that examined factors related to fatigue to gain more insight into its possible causes and consequences.MethodsMedline, Web of Science, Scopus, and PsycINFO were searched for relevant studies. All studies with RA samples about the relationship between fatigue and other variables that defined dependent and independent variables and used multivariate statistical methods were preliminarily included. After reviewing 129 full texts, we identified 25 studies on possible causes of fatigue and 17 studies on possible consequences of fatigue.ResultsThe studies found possible causes of fatigue in illness‐related aspects, physical functioning, cognitive/emotional functioning, and social aspects. Additionally, being a woman was related to higher levels of fatigue. Inflammatory activity showed an unclear relationship with fatigue in RA. Possible consequences of fatigue were also found among illness‐related aspects, physical functioning, cognitive/emotional functioning, and social aspects. The strongest evidence for a relationship between fatigue and other variables was found regarding pain, physical functioning, and depression.ConclusionThis review summarizes the current knowledge in the field in order to inform future research on causes and consequences of fatigue in RA. However, the results are based on cross‐sectional and longitudinal studies with different designs and different fatigue scales. For a better identification of causal associations between fatigue in RA and related factors, longitudinal prospective designs with adequate fatigue measurements are suggested.
Pain Severity and Neuropathic Pain Symptoms in Primary Sjögren's Syndrome: A Comparison Study of Seropositive and Seronegative Sjögren's Syndrome Patients
Authors: Segal Barbara M. , Pogatchnik Brian , Henn Lisa , Rudser Kyle , Sivils Kathy Moser 
Published: January 2013

ObjectiveTo compare clinical characteristics and patient‐reported outcomes in seropositive versus seronegative primary Sjögren's syndrome (SS) patients and to investigate the effect of serologic status on the prevalence of chronic pain, comorbidity, and health quality.MethodsPain severity and neuropathic pain symptoms, comorbidity, and health status were assessed in 108 primary SS patients. Differences between patient groups were assessed by t‐test and chi‐square test, as well as adjusted pain–affect associations. The effect of predictor variables on pain severity was examined with multivariate regression.ResultsPain severity was greater (P = 0.003) and physical function (P = 0.023) was reduced in the seronegative patients. Prevalence of neuropathic pain, depression, anxiety, and disability was similar between groups. Chronic pain, defined as daily pain for >3 months, was reported by 65% of seropositive (n = 65) and 75% of seronegative (n = 40) patients. After adjustment for age, sleep quality, and psychological distress, the difference in pain severity between seropositive and seronegative patients remained significant.ConclusionChronic pain is pervasive in both seropositive and seronegative primary SS patients, while pain severity and functional impairment are greater in seronegative patients. Neuropathic pain is equally prevalent and is the predominant pain phenotype in patients with moderate to severe pain. Accurate assessment of pain phenotypes is needed for more effective management of chronic pain in primary SS. The focus of future research should be to standardize assessment of pain and to identify the factors contributing to more severe pain in seronegative patients.
Sternoclavicular Joint Involvement in Rheumatoid Arthritis: Clinical and Ultrasound Findings of a Neglected Joint
Authors: Rodríguez‐Henríquez Pedro , Solano Carla , Peña Angélica , León‐Hernández Saúl , Hernández‐Díaz Cristina , Gutiérrez Marwin , Pineda Carlos 
Published: January 2013

ObjectiveTo describe the prevalence of sternoclavicular (SC) joint involvement and the relationship between clinical and ultrasound (US) findings in patients with rheumatoid arthritis (RA).MethodsOne hundred three consecutive patients with RA and 103 age‐ and sex‐matched healthy individuals were enrolled. Clinical evaluation and blinded US examinations of the SC joint were performed bilaterally in both groups. The presence of gray‐scale synovitis, osteophytes, erosions, and intraarticular power Doppler (PD) was recorded. Interobserver agreement was calculated.ResultsA total of 412 SC joints were evaluated: 206 from patients with RA and 206 from healthy controls. In the RA group, 39 joints (19%) were found to be clinically involved (pain/swelling), in contrast to only 4 (1.9%) in the control group (P = 0.0001). In the RA group, US abnormalities were recorded in 89 SC joints (43%) compared with 36 (17%) in the healthy control group (P = 0.0001), comprising osteophytes in 59 (29%) versus 25 (12%; P = 0.0001), synovitis in 31 (15%) versus 5 (2%; P = 0.0001), erosions in 23 (11%) versus none (P = 0.0001), and intraarticular PD in 5 (2%) versus none (P = 0.03). Furthermore, a correlation between the presence of US synovitis (P < 0.001) and intraarticular PD (P < 0.0001) with a higher Disease Activity Score in 28 joints (DAS28) was found.ConclusionIn patients with RA, US detected a higher number of involved SC joints than with clinical assessment. Our results indicate that both gray‐scale and PD US findings were more prevalent in patients with RA than in healthy controls. US synovitis and synovial hyperperfusion correlated with the DAS28, suggesting that SC joints actively participate in the systemic inflammatory process of RA.
Self‐Assembly of π‐Conjugated Amphiphiles: Free Standing, Ordered Sheets with Enhanced Mobility
Authors: Narayan Bhawani , Senanayak Satyaprasad P. , Jain Ankit , Narayan K. S. , George Subi J. 
Published: January 2013

AbstractOligo(p‐phenylenevinylenes) (OPVs) with amphiphilic character are synthesized and their self‐assembly characteristics studied. Careful studies point at two morphologically different states of assemblies, with one being two dimensional sheets and the other as rolled tubes. This is also the first time that self‐assembled sheets are achieved for OPVs. Morphological and photo‐physical studies reveal a unique aggregate to aggregate transition between rolled tubes and two dimensional sheets, which is outlined as a more thermodynamic aggregate. The thermodynamic aggregate (2D sheet) is better ordered and consists of chromophores that are better excitonically coupled. The mobilities of these aggregates are also studied for a field effect transistor device and as expected sheets supersede rolled tubes by a couple of orders. More interestingly, the mobility values obtained for the well ordered chromophores in sheets is three orders higher than any other self‐assembled OPV previously reported. It is hypothesized that the better π interactions enforced by the amphiphilic design and the resultant supramolecular organization is a prime factor for such a remarkable rise in mobilities.
Location, Location, Location ‐ Strategic Positioning of 2,1,3‐Benzothiadiazole Units within Trigonal Quaterfluorene‐Truxene Star‐Shaped Structures
Authors: Belton Colin R. , Kanibolotsky Alexander L. , Kirkpatrick James , Orofino Clara , Elmasly Saadeldin E. T. , Stavrinou Paul N. , Skabara Peter J. , Bradley Donal D. C. 
Published: January 2013

AbstractThe fused, bicyclic molecule, 2,1,3‐Benzothiadiazole (BT), has become a key ingredient in the design of new organic semiconductors for light emission and energy harvesting applications. Here, the synthesis is reported of a series of trigonal, star‐shaped compounds comprising a truxene core and three quater‐dialkylfluorene arms into each of which a BT unit is inserted sequentially at each possible position (T4BT‐A to T4BT‐E). Analysis of the resulting electronic properties shows that as a consequence of conjugative coupling to the core and the resulting symmetry there are three distinct locations for the BT unit and the influence that these locations have on light emission and other spectroscopic characteristics is discussed. The systematic variation in photophysical properties for the different structural isomers helps to clarify the influence of BT unit addition to 9,9‐dialkylfluorene chains. It also helps to establish a design template for the construction of donor‐acceptor conjugated materials with targeted properties. For T4BT‐E with a BT unit at the terminal position of each arm, the photoluminescence quantum efficiency is significantly reduced and no amplified spontaneous emission is observed under typical pumping conditions. Theoretical calculations assist in understanding the variation in behaviors among the T4BT‐X family of compounds, especially in relation to their photoluminescence decay times and the Raman scattering intensities of their dominant BT‐unit‐centred molecular vibrations.
Combining molecular imprinted nanoparticles with surface plasmon resonance nanosensor for chloramphenicol detection in honey
Authors: Kara Meryem , Uzun Lokman , Kolayli Sevgi , Denizli Adil 
Published: January 2013

AbstractThe focus of this article is to develop a surface plasmon resonance (SPR) nanosensor to determine chloramphenicol (CAP) using the molecularly imprinted nanoparticles. The CAP imprinted nanoparticles were prepared by miniemulsion polymerization method. Then, the nanoparticles were attached onto the SPR nanosensor surface via temperature‐controlled evaporation. Surface characterization studies were performed with atomic force microscopy and contact angle measurements. Kinetic studies were performed with CAP solutions in the concentration range of 0.155–6.192 nM. Florphenicol (FLP) and thiamphenicol (TAP) having similar chemical structures to the template (i.e., CAP) were chosen as competitors to determine selectivity of the nanoparticles. Selectivity constants were observed as 8.86 for CAP/TAP and 8.36 for CAP/FLP. The detection limit was calculated as 40 ng/kg honey sample. In the light of these results, it was emphasized that the SPR nanosensor is able to recognize CAP selectively and has a potential for real‐time CAP detection in honey sample. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of poly(ϵ‐caprolactone‐co‐p‐dioxanone)–poly(ethylene glycol)–poly(ϵ‐caprolactone‐co‐p‐dioxanone)/bioactive inorganic particle nanocomposites
Authors: Chen Rui , Hao Jianyuan 
Published: January 2013

AbstractWith an aim to develop injectable hydrogel with improved solution stability and enhanced bone repair function, thermogelling poly(ε‐caprolactone‐co‐p‐dioxanone)‐poly(ethylene glycol)‐poly(ε‐caprolactone–co‐p‐dioxanone) (PECP)/bioactive inorganic particle nanocomposites were successfully prepared by blending the triblock copolymer (PECP) with nano‐hydroxyapatite (n‐HA) or nano‐calcium carbonate (n‐CaCO3). The hydrogel nanocomposites underwent clear sol–gel transitions with increasing temperature from 0 to 50°C. The obtained hydrogel nanocomposites were investigated by 1H NMR, FT‐IR, TEM, and DSC. It was found that the incorporation of inorganic nanoparticles into PECP matrix would lead to the critical gelation temperature (CGT) shifting to lower values compared with the pure PECP hydrogel. The CGT of the hydrogel nanocomposites could be effectively controlled by adjusting PECP concentration or the content of inorganic nanoparticles. The SEM results showed that the interconnected porous structures of hydrogel nanocomposites were potentially useful as injectable scaffolds. In addition, due to the relatively low crystallinity of PECP triblock copolymer, the aqueous solutions of the nanocomposites could be stored at low temperature (5°C) without crystallization for several days, which would facilitate the practical applications. The PECP/bioactive inorganic particle hydrogel nanocomposites are expected to be promising injectable tissue engineering materials for bone repair applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fibro‐porous polycaprolactone membrane containing extracts of Biophytum sensitivum: A prospective antibacterial wound dressing
Authors: Namboodiri Arjun Govindan , Parameswaran Ramesh 
Published: January 2013

AbstractA fibro‐porous wound dressing with antibacterial activity was fabricated from polycaprolactone (PCL) solution containing crude extract of biophytum sensitivum (BS) a potential antibacterial herbal drug. Scanning electron microscopy revealed the smooth fibrous morphology of the PCL membrane, whereas the drug‐loaded PCL formed fibers with more interconnective junctions with an average fiber diameter between 1 and 3 μm. Physical characterization of the membrane revealed that it has excellent mechanical stability, water vapor transmission rate and that it promotes water uptake. The release characteristics by total immersion method in phosphate buffer and acetate buffer displayed an increase in drug release with time. Finally, the antibacterial activity of the membrane was tested against standard strains of Staphylococcus aureus and Escherichia coli. PCL membranes loaded with the drug extracts were able to inhibit the growth of bacterial strains which indicated that this fibro‐porous membrane could act as a potential wound‐dressing material to treat various wounds. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Transport properties of sulfonated poly (styrene‐isobutylene‐styrene) membranes with counter‐ion substitution
Authors: Avilés‐Barreto Sonia L. , Suleiman David 
Published: January 2013

AbstractIn this study, the transport properties of poly(styrene‐isobutylene‐styrene) (SIBS) were determined as a function of sulfonation level (0–94.9%) and counter‐ion substitution (Ba+2, Ca+2, Mg+2, Mn+2, Cu+2, K+1) for fuel cell applications. Increasing the sulfonation level improved the ion exchange capacity (IEC) of the membranes up a maximum (1.71 mequiv/g), suggesting a complex three‐dimensional network at high sulfonation levels. Results show that proton conductivity increases with IEC and is very sensitive to hydration levels. Methanol permeability, although also sensitive to IEC, shows a different behavior than proton conductivity, suggesting fundamental differences in their transport mechanism. The incorporation of counter‐ion substitution decreases both methanol and proton transport. Methanol permeability seems to be related to the size of the counter‐ion studied, while proton conductivity is more sensitive to water content, which is also reduced upon the incorporation of counter‐ions. To complement the studies, selectivity (i.e., proton conductivity/methanol permeability) of the studied membranes was determined and compared to Nafion® 117. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Hypoxia Promotes the Production and Inhibits the Destruction of Human Articular Cartilage
Authors: Thoms Brendan L. , Dudek Katarzyna A. , Lafont Jérôme E. , Murphy Christopher L. 
Published: January 2013

AbstractObjectiveTo determine the effects of hypoxia on both anabolic and catabolic pathways of metabolism in human articular cartilage and to elucidate the roles played by hypoxia‐inducible factors (HIFs) in these responses.MethodsNormal human articular cartilage from a range of donors was obtained at the time of above‐the‐knee amputations due to sarcomas not involving the joint space. Fresh cartilage tissue explants and isolated cells were subjected to hypoxia and treatment with interleukin‐1α. Cell transfections were performed on isolated human chondrocytes.ResultsUsing chromatin immunoprecipitation, we found that hypoxia induced cartilage production in human tissue explants through direct binding of HIF‐2α to a specific site in the master‐regulator gene SOX9. Importantly, hypoxia also suppressed spontaneous and induced destruction of human cartilage in explant culture. We found that anticatabolic responses were predominantly mediated by HIF‐1α. Manipulation of the hypoxia‐sensing pathway through depletion of HIF‐targeting prolyl hydroxylase–containing protein 2 (PHD‐2) further enhanced cartilage responses as compared to hypoxia alone. Hypoxic regulation of tissue‐specific metabolism similar to that in human cartilage was observed in pig, but not mouse, cartilage.ConclusionWe found that resident chondrocytes in human cartilage are exquisitely adapted to hypoxia and use it to regulate tissue‐specific metabolism. Our data revealed that while fundamental regulators, such as SOX9, are key molecules both in mice and humans, the way in which they are controlled can differ. This is all the more important since it is upstream regulators such as this that need to be directly targeted for therapeutic benefit. HIF‐specific hydroxylase PHD‐2 may represent a relevant target for cartilage repair.
Curcumin and aging
Authors: Shen Li‐Rong , Parnell Laurence D. , Ordovas Jose M. , Lai Chao‐Qiang 
Published: January 2013

AbstractTurmeric has been used commonly as a spice, food additive, and an herbal medicine worldwide. Known as a bioactive polyphenolic extract of Turmeric, curcumin has a broad range of health benefit properties for humans. Recently, active research on curcumin with respect to aging and related traits in model organisms has demonstrated that curcumin and its metabolite, tetrahydrocurcumin (THC), increase mean lifespan of at least three model organisms: nematode roundworm, fruit flyDrosophila,and mouse. Nematodes grown on media containing curcumin showed a significantly increased lifespan by reducing the production of reactive oxygen species. Genesosr‐1, sek‐1, mek‐1, skn‐1, unc‐43, sir‐2.1, andage‐1are required for curcumin‐mediated lifespan extension. The lifespan extension ofDrosophilaby curcumin supplementation was associated with increased superoxide dismutase (SOD) activity, and decreased lipofuscin and malondialdehyde levels. Curcumin up‐regulated expression of SOD genes and down‐regulated expression of several age‐related genes, such asdInR, ATTD, Def, CecB,andDptB.In addition, THC extended lifespan inDrosophilaand inhibited the oxidative stress response by regulatingFOXOandSir2.Mice fed diets containing THC starting at the age of 13 months had significantly increased mean lifespan. In summary, the positive effects of curcumin on lifespan extension likely arise from beneficial regulation of common oxidative stress responses and age‐related genes. Understanding the molecular mechanism(s) of curcumin action has provided base knowledge and rationale for future human clinical trials, and for nutritional intervention in aging and age‐associated disorders in humans. © 2013 BioFactors, 39(1):133–140, 2013
Biotinylated Phosphoproteins from Kinase‐Catalyzed Biotinylation are Stable to Phosphatases: Implications for Phosphoproteomics
Authors: Senevirathne Chamara , Pflum Mary Kay H. 
Published: January 2013

AbstractKinase‐catalyzed protein phosphorylation is involved in a wide variety of cellular events. Development of methods to monitor phosphorylation is critical to understand cell biology. Our lab recently discovered kinase‐catalyzed biotinylation, where ATP‐biotin is utilized by kinases to label phosphopeptides or phosphoproteins with a biotin tag. To exploit kinase‐catalyzed biotinylation for phosphoprotein purification and identification in a cellular context, the susceptibility of the biotin tag to phosphatases was characterized. We found that the phosphorylbiotin group on peptide and protein substrates was relatively insensitive to protein phosphatases. To understand how phosphatase stability would impact phosphoproteomics research applications, kinase‐catalyzed biotinylation of cell lysates was performed in the presence of kinase or phosphatase inhibitors. We found that biotinylation with ATP‐biotin was sensitive to inhibitors, although with variable effects compared to ATP phosphorylation. The results suggest that kinase‐catalyzed biotinylation is well suited for phosphoproteomics studies, with particular utility towards monitoring low‐abundance phosphoproteins or characterizing the influence of inhibitor drugs on protein phosphorylation.
Synthesis and Reactivity of Cationic Triruthenium Clusters Derived from 2‐Methyl‐ and 4‐Methylpyrimidines: From Conventional Cyclometalated Ligands to Novel Types of N‐Heterocyclic Carbenes
Authors: Cabeza Javier A. , García‐Álvarez Pablo , Pérez‐Carreño Enrique , Pruneda Vanessa 
Published: January 2013

AbstractThe methylation of the uncoordinated nitrogen atom of the cyclometalated triruthenium cluster complexes [Ru3(μ‐H)(μ‐κ2N1,C6‐2‐Mepyr)(CO)10] (1; 2‐MepyrH=2‐methylpyrimidine) and [Ru3(μ‐H)(μ‐κ2N1,C6‐4‐Mepyr)(CO)10] (9; 4‐MepyrH=4‐methylpyrimidine) gives two similar cationic complexes, [Ru3(μ‐H)(μ‐κ2N1,C6‐2,3‐Me2pyr)(CO)10]+(2+) and [Ru3(μ‐H)(μ‐κ2N1,C6‐3,4‐Me2pyr)(CO)10]+ (9+), respectively, whose heterocyclic ligands belong to a novel type of N‐heterocyclic carbenes (NHCs) that have the Ccarbene atom in 6‐position of a pyrimidine framework. The position of the C‐methyl group in the ligands of complexes 2+ (on C2) and 9+ (on C4) is of key importance for the outcome of their reactions with K[N(SiMe3)2], K‐selectride, and cobaltocene. Although these reagents react with 2+ to give [Ru3(μ‐H)(μ‐κ2N1,C6‐2‐CH2‐3‐Mepyr)(CO)10] (3; deprotonation of the C2‐Me group), [Ru3(μ‐H)(μ3‐κ3N1,C5,C6‐4‐H‐2,3‐Me2pyr)(CO)9] (4; hydride addition at C4), and [Ru6(μ‐H)2{μ6‐κ6N1,N1′,C5,C5′,C6,C6′‐4,4′‐bis(2,3‐Me2pyr)}(CO)18] (5; reductive dimerization at C4), respectively, similar reactions with 9+ have only allowed the isolation of [Ru3(μ‐H)(μ3‐κ2N1,C6‐2‐H‐3,4‐Me2pyr)(CO)9] (11; hydride addition at C2). Compounds 3 and 11 also contain novel six‐membered ring NHC ligands. Theoretical studies have established that the deprotonation of 2+ and 9+ (that have ligand‐based LUMOs) are charge‐controlled processes and that both the composition of the LUMOs of these cationic complexes and the steric protection of their ligand ring atoms govern the regioselectivity of their nucleophilic addition and reduction reactions.
Giant Fullerene Polyelectrolytes Composed of C60 Building Blocks with an Octahedral Addition Pattern and Discovery of a New Cyclopropanation Reaction Involving Dibromomalonates
Authors: Hörmann Frank , Hirsch Andreas 
Published: January 2013

AbstractWe report here on the facile synthetic access of a new family of bis‐, tetra‐, hexa‐, and heptafullerenes (prototypes I–IV), which can be easily converted into very water soluble polyelectrolytes with up to 60 charges located on their periphery. Their very regioselective formation is based on the use of C2v‐symmetrical pentakisadducts 3 and hexakisadducts 2 as key intermediates. All fullerene moieties incorporated in these macromolecular structures involve a complete or partial octahedral addition pattern. Tripod‐shaped tetrafullerenes 9 a,b (type II), which can accumulate up to thirty positive or negative charges, are very soluble in acidic or basic water, respectively. Hexafullerenes 13 a,b (type III) were synthesized via isoxazolinofullerenes 10 followed by photolytic cleavage of the isoxazoline group. The giant heptafullerene 1 b (type IV) representing the anionic counterpart of the previously synthesized polyelectrolyte 1 a can store up to 60 negative charges on its periphery within a defined three‐dimensional structure. We also discovered a new cyclopropanation reaction of C60 involving dibromomalonates and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU). This reaction allows even for the highly regioselective formation of hexakisadducts with an octahedral addition pattern without requiring activation with reversibly binding addends such as 9,10‐dimethylanthracene (DMA).