bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of polypropylene–clay nanocomposites by the co‐intercalation of modified polypropylene and short‐chain amide molecules
Authors: Ratnayake U. N. , Haworth B. , Hourston D. J. 
Published: December 2008

AbstractThe effect of short‐chain amide (AM) molecules on the intercalation of montmorillonite clay has been investigated by the melt blending of polypropylene (PP) with clay in the presence of AM molecules such as 13‐cis‐docosenamide (erucamide). Polypropylene–clay nanocomposites (PPCNs) were prepared by the co‐intercalation of maleic anhydride grafted polypropylene (PP–MA) and an AM compound. The resulting nanocomposite structures were characterized with X‐ray diffraction (XRD) and transmission electron microscopy, whereas the thermal characterization of the PPCNs was conducted by thermogravimetric analysis. XRD results showed that the AM molecules intercalated into clay galleries and increased the interlayer spacing, a result confirmed by surface energy (contact angle) and melt flow index measurements. This additive allowed the formation of an intercalated nanocomposite structure, but an exfoliated PPCN structure was also formed with the use of AM with a PP–MA‐based compatibilizer. A new preparation method for PPCNs was, therefore, developed by the co‐intercalation of AM and PP–MA; this resulted in a significantly improved degree of intercalation and dispersion. The enhanced thermal stability of PPCN, relative to pure PP, further demonstrated the improved clay dispersion in the nanocomposite structures prepared by this method. A possible mechanism for the co‐intercalation of AM and PP–MA into the clay galleries is proposed, based on hydrogen bonding between these additives and the silicate layers. Consideration is also given to possible chemical reactions and physical interactions in this rather complex system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of polyelectrolyte complex membranes based on sodium cellulose sulfate and poly(dimethyldiallylammonium chloride) and its permeability properties
Authors: Li Ming‐Ming , Yao Shan‐Jing 
Published: December 2008

AbstractIn this study, polyelectrolyte complex (PELC) membranes prepared by the simultaneous interfacial reaction between aqueous solutions of sodium cellulose sulfate (NaCS) as polyanion and poly(dimethyldiallylammonium chloride) (PDMDAAC) as polycation were proposed. The preparation conditions were optimized. The influence of two important factors, molecular weight (MW) of PDMDAAC and reaction time on the membrane formation procedure and permeability was investigated. Membranes with the preparation conditions as NaCS 3.5% (w/v), PDMDAAC (MW = 200–350 kDa) 7.0% (w/v), the reaction time 30 min, hold a favorable performance, and steady state in water flux experiment. To testify the feasibility of the membrane used in salt separation, membrane performances and selectivity of the inorganic salts as well as their relations to the preparation conditions, the operation parameters, the species of inorganic salts, etc., were investigated in the pressure‐driven experiments. The results showed that this single‐layer PELC membrane afforded higher rejections of divalent ions (SO) to that of monovalent ions (Cl−), which indicated the potential application of this membrane system in the salt rejection process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Poly(ethylene glycol)‐based hydrogels as cartilage substitutes: Synthesis and mechanical characteristics
Authors: Rakovsky A. , Marbach D. , Lotan N. , Lanir Y. 
Published: December 2008

AbstractCartilage substitutes are needed to replace cartilage tissue, damaged in accidents or by pathologies (e.g., osteoarthritis). Treatment by total hip replacement has disadvantages, particularly due to immunological reaction to the implant's wear debris. One promising alternative is to replace damaged cartilage with substitutes based on hydrogel‐type material, designed to mimic the structure and properties of cartilage. The development of such a substitute must consider a wide spectrum of requirements. In this study, we addressed one aspect of this development namely the preparation and investigation of hydrogels exhibiting the required mechanical characteristics. To this aim, poly(ethylene glycol) (PEG) hydrogels and amphiphilic interpenetrating polymer networks (IPNs) of PEG with poly(methyl methacrylate) (PMMA) were prepared and characterized for their mechanical and swelling properties. Twenty‐seven types of hydrogels were synthesized, differing in their composition: PEG molecular weight, crosslink density, and PMMA volume fraction. The properties measured were water content, compression modulus, strength, fatigue durability, and poroelastic properties (hydraulic permeability and equilibrium modulus). All were investigated as functions of hydrogel's composition. Results show that lower PEGMw, higher crosslink densities and higher PMMA fraction, all lead to higher modulus and lower water content, and that these properties can be controlled independently by proper choice of ingredients. Introduction of IPN greatly improved the hydrogels' strength. No reduction in the compression modulus resulting from fatigue damage was evident. Poroelastic properties varied nonmonotonously with structural characteristics. Seven types of the hydrogels were found to fit cartilage in their water content, modulus, and poroelastic properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Controlled delivery of diclofenac sodium from calcium alginate beads loaded with a drug–resin complex
Authors: Saxena Sutanjay , Bajpai S. K. 
Published: December 2008

AbstractThis study focused on a detailed investigation of the release of the nonsteroidal anti‐inflammatory drug diclofenac sodium from strong anion resin particles, entrapped in ionotropically crosslinked alginate beads, in simulated gastric and intestinal fluids at 37°C. The percentage drug released from the beads in media of various pH values in 6 h was nearly 68.8 ± 2.6%, whereas, for the same duration, the drug–resin complex particles released 87.6 ± 3.2% drug. The amount of drug released from the beads depended on the composition of the beads, their degree of crosslinking, and the size of the crosslinker ions. Finally, the value of the release exponent was found to be 0.56, which thus indicated the diffusion‐controlled mechanism of drug release from the alginate beads © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Stereological Estimates of Alveolar Number and Size and Capillary Length and Surface Area in Mice Lungs
Authors: Knust Juliane , Ochs Matthias , Gundersen Hans Jørgen G. , Nyengaard Jens R. 
Published: December 2008

AbstractThe major function of the lung is gas exchange and depends on alveolar and capillary parameters such as surface area and volume. The number of alveoli may report on the nature of structural changes in lung parenchyma during development, illness or changing environmental factors. We therefore developed an efficient and easily applicable stereological design for estimating and monitoring these structural parameters in the mouse lung. The estimation of volume fractions of different lung compartments has been carried out by point counting. A combination of cycloid grids superimposed on vertical sections was used to estimate the capillary surface area with isotropic test lines. Capillary length could be measured using the harmonic mean of the surface weighted diameter. The Euler characteristic applied in the physical fractionator with varying but known sampling fractions (Horovitz‐Thompson estimator) enabled us to estimate alveolar number. In adult mice lungs, we obtained total values for alveolar number of 2.31 × 106 alveoli in a pair of lungs, alveolar surface area of 82.2 cm2, capillary surface area of 124 cm2, and capillary length of 1.13 km. All values are corrected for tissue shrinkage. With this study we present a highly efficient combination of several design‐based stereological tools for the unbiased estimation of alveolar number and volume as well as length, surface area, and diameter of capillaries in the mice lung. Anat Rec, 292:113–122, 2009. © 2008 Wiley‐Liss, Inc.
The Three‐Dimensional Arrangement of the Myocytes Aggregated Together Within the Mammalian Ventricular Myocardium
Authors: Smerup Morten , Nielsen Eva , Agger Peter , Frandsen Jesper , Vestergaard‐Poulsen Peter , Andersen Johnnie , Nyengaard Jens , Pedersen Michael , Ringgaard Steffen , Hjortdal Vibeke , Lunkenheimer Paul P. , Anderson Robert H. 
Published: December 2008

AbstractA 3‐D helical arrangement of aggregates of myocytes in a pig's heart revealed by diffusion tensor MRI. See Smerup et al., on page 1, of this issue.
Preparing for adulthood: Health care transition counseling for youth with arthritis
Authors: Scal Peter , Horvath Keith , Garwick Ann 
Published: December 2008

AbstractObjectiveTo determine the proportion of adolescents with arthritis who receive health care transition services and to compare the rates with those reported for adolescents with other special health care needs and adolescents with diabetes.MethodsWe used data from the 2005–2006 National Survey of Children with Special Health Care Needs. A parent/guardian identified youth ages 12–17 years with arthritis (n = 1,052), diabetes (n = 389), and special health care needs (n = 18,189). Four questions examined the extent to which providers discussed health care transition issues, including 1) transfer of care to adult providers, 2) health care needs of adults, 3) acquiring health insurance, and 4) encouraging self‐care responsibility. Bivariate comparisons assessed the associations between sociodemographic characteristics and health care transition services, and multivariate regression models compared outcomes between conditions.ResultsMany adolescents with arthritis are being encouraged to assume self‐care responsibilities (74.8%); fewer discussed how health needs will change in adulthood (52.1%), acquiring insurance (22.5%), or transferring care to a provider who sees adults (19.0%). These results are similar to youth with other special health care needs, but behind youth with diabetes.ConclusionAmong this sample of US adolescents, many report discussions about health care needs and self‐management, but few are addressing critical aspects of the transition to adult‐oriented health care.
Pain induced by injection of hypertonic saline into the infrapatellar fat pad and effect on coordination of the quadriceps muscles
Authors: Hodges Paul W. , Mellor Rebecca , Crossley Kay , Bennell Kim 
Published: December 2008

AbstractObjectiveMusculoskeletal conditions of the knee involve changes in sensorimotor function, but it is unclear whether these changes are a cause or result of pain. Induction of experimental pain may help solve this issue. Although this is commonly achieved by injection of hypertonic saline into muscle, muscle is commonly not the source of pain. This study investigated whether pain induced by injection of saline into the infrapatellar fat pad changes motor control of the quadriceps muscles of the knee.MethodsTen participants performed a standardized task involving ascending and descending a series of steps. Electromyographic activity (EMG) of vastus medialis obliquus (VMO) and vastus lateralis (VL) was recorded with surface electrodes. Trials were conducted without pain, with anterior knee pain induced by injection (0.25 ml) of hypertonic saline (5%) into the infrapatellar fat pad, with anticipation of pain associated with unpredictable electrical shocks to the knee, and 20 minutes after pain cessation. EMG onset and amplitude were analyzed.ResultsWhen participants ascended the steps with pain, the onset of VMO EMG was delayed relative to that of VL, in contrast to simultaneous or earlier activation of VMO EMG in the pre‐ and postpain trials. VL EMG amplitude was decreased significantly from the control condition.ConclusionThese data show that alterations in coordination of knee muscle activity can be caused by pain, even when it is of nonmuscle origin. Treatment of pain is therefore important to facilitate performance of the quadriceps muscles, which are essential for locomotor and functional tasks as well as for knee stability.
Musculoskeletal sonography in juvenile systemic lupus erythematosus
Authors: Demirkaya Erkan , Özçakar Levent , Türker Türker , Haghari Sama , Ayaz Nuray Aktay , Bakkaloǧlu Ayşin , Özen Seza 
Published: December 2008

AbstractObjectiveTo demonstrate the role of sonography in depicting periarticular changes in juvenile systemic lupus erythematosus (SLE) and to find out whether certain tendons in juvenile SLE patients were different from those of healthy controls.MethodsThirty juvenile SLE patients (27 female, 3 male) were recruited for this study. Sonographic evaluations were performed in the knee, ankle, elbow, wrist, and metacarpophalangeal (MCP) joints on the nondominant sides of the individuals. For comparison, 32 healthy volunteers were included as a control group.ResultsKnee effusion was observed more frequently in the juvenile SLE group compared with the control group (P = 0.00). When tendon thickness measurements were compared between the groups, flexor and extensor tendons of the third finger (at MCP joint level) of juvenile SLE patients were found to be thinner (P = 0.04 and P = 0.03, respectively). Tendon thickness values did not correlate with disease duration or SLE disease activity index scores (P > 0.05).ConclusionThe main findings of our study were relevant with 1) increased involvement of the knee, ankle, hand extensor tendons, wrist, elbow, and hand flexor tendons (in decreasing order of frequencies) in juvenile SLE, and 2) decreased extensor/flexor tendon thicknesses in the hands of juvenile SLE patients. Physicians should be aware of the potentially disabling scenario of tendon pathologies. Defining the extent of joint and tendon pathologies in juvenile SLE may guide us in the management of the disease.
Differences in long‐term disease activity and treatment of adult patients with childhood‐ and adult‐onset systemic lupus erythematosus
Authors: Hersh Aimee O. , von Scheven Emily , Yazdany Jinoos , Panopalis Pantelis , Trupin Laura , Julian Laura , Katz Patricia , Criswell Lindsey A. , Yelin Edward 
Published: December 2008

AbstractObjectiveTo compare differences in long‐term outcome between adults with childhood‐onset (age at diagnosis <18 years) systemic lupus erythematosus (SLE) and with adult‐onset SLE.MethodsData were derived from the University of California Lupus Outcomes Study, a longitudinal cohort of 885 adult subjects with SLE (90 childhood‐onset [cSLE], 795 adult‐onset [aSLE]). Baseline and 1‐year followup data were obtained via structured 1‐hour telephone interviews conducted between 2002 and 2006. Using self‐report data, differences in organ involvement and disease morbidity, current disease status and activity, past and current medication use, and number of physician visits were compared, based on age at diagnosis of SLE.ResultsAverage disease duration for the cSLE and aSLE subgroups was 16.5 and 13.4 years, respectively, and mean age at followup was 30.5 and 49.9 years, respectively. When compared with aSLE subjects, cSLE subjects had a higher frequency of SLE‐related renal disease, whereas aSLE subjects were more likely to report a history of pulmonary disease. Rates of clotting disorders, seizures, and myocardial infarction were similar between the 2 groups. At followup, cSLE subjects had lower overall disease activity, but were more likely to be taking steroids and other immunosuppressive therapies. The total number of yearly physician visits was similar between the 2 groups, although cSLE subjects had a higher number of nephrology visits.ConclusionThis study demonstrates important differences in the outcomes of patients with cSLE and aSLE, and provides important prognostic information about long‐term SLE disease activity and treatment.
Blocking vascular endothelial growth factor with soluble Flt‐1 improves the chondrogenic potential of mouse skeletal muscle–derived stem cells
Authors: Kubo Seiji , Cooper Gregory M. , Matsumoto Tomoyuki , Phillippi Julie A. , Corsi Karin A. , Usas Arvydas , Li Guangheng , Fu Freddie H. , Huard Johnny 
Published: December 2008

AbstractObjectiveTo investigate the effect of vascular endothelial growth factor (VEGF) stimulation and the effect of blocking VEGF with its antagonist, soluble Flt‐1 (sFlt‐1), on chondrogenesis, using muscle‐derived stem cells (MDSCs) isolated from mouse skeletal muscle.MethodsThe direct effect of VEGF on the in vitro chondrogenic ability of mouse MDSCs was tested using a pellet culture system, followed by real‐time quantitative polymerase chain reaction (PCR) and histologic analyses. Next, the effect of VEGF on chondrogenesis within the synovial joint was tested, using genetically engineered MDSCs implanted into rat osteochondral defects. In this model, MDSCs transduced with a retroviral vector to express bone morphogenetic protein 4 (BMP‐4) were coimplanted with MDSCs transduced to express either VEGF or sFlt‐1 (a VEGF antagonist) to provide a gain‐ and loss‐of‐function experimental design. Histologic scoring was used to compare cartilage formation among the treatment groups.ResultsHyaline‐like cartilage matrix production was observed in both VEGF‐treated and VEGF‐blocked (sFlt‐1–treated) pellet cultures, but quantitative PCR revealed that sFlt‐1 treatment improved the expression of chondrogenic genes in MDSCs that were stimulated to undergo chondrogenic differentiation with BMP‐4 and transforming growth factor β3 (TGFβ3). In vivo testing of articular cartilage repair showed that VEGF‐transduced MDSCs caused an arthritic change in the knee joint, and sFlt‐1 improved the MDSC‐mediated repair of articular cartilage, compared with BMP‐4 alone.ConclusionSoluble Flt‐1 gene therapy improved the BMP‐4– and TGFβ3‐induced chondrogenic gene expression of MDSCs in vitro and improved the persistence of articular cartilage repair by preventing vascularization and bone invasion into the repaired articular cartilage.
Recovery: What does this mean to patients with low back pain?
Authors: Hush Julia M. , Refshauge Kathryn , Sullivan Gerard , De Souza Lorraine , Maher Christopher G. , McAuley James H. 
Published: December 2008

AbstractObjectiveTo explore patients' perceptions of recovery from low back pain, about which little is known.MethodsA qualitative study was conducted in which 36 participants, either recovered or unrecovered from low back pain, participated in focus groups. Interviews were audiorecorded and transcribed verbatim. Framework analysis was used to identify emergent themes and domains of recovery.ResultsPatients' views of recovery encompassed a range of factors that can be broadly classified into the domains of symptom attenuation, improved capacity to perform a broad scope of self‐defined functional activities, and achievement of an acceptable quality of life. An interactive model is proposed to describe the relationships between these domains, cognitive appraisal of the pain experience, and self‐rated recovery. Pain attenuation alone was not a reliable indicator of recovery.ConclusionThe construct of recovery for typical back pain patients seeking primary care is more complex than previously recognized and is a highly individual construct, determined by appraisal of the impact of symptoms on daily functional activities as well as quality of life factors. These findings will be valuable for reassessing how to optimize measures of recovery from low back pain by addressing the spectrum of factors patients consider meaningful.
Successful treatment of idiopathic recurrent pericarditis in children with interleukin‐1β receptor antagonist (anakinra): An unrecognized autoinflammatory disease?
Authors: Picco Paolo , Brisca Giacomo , Traverso Francesco , Loy Anna , Gattorno Marco , Martini Alberto 
Published: December 2008

AbstractRecurrent pericarditis occurs in association with various medical conditions, but in most cases the condition appears to be idiopathic. Although high‐dose steroid treatment is often effective, it may have serious side effects. Herein we describe 3 children with recurrent pericarditis who were treated at our hospital, during flares, with the interleukin‐1β receptor antagonist anakinra, with immediate response. Pericarditis recurred when anakinra treatment was discontinued, and no further episodes occurred after it was resumed. Idiopathic recurrent pericarditis shares several features with autoinflammatory diseases, and anakinra has been efficacious in the treatment of the latter diseases. The findings in these patients suggest that idiopathic recurrent pericarditis may be a previously unrecognized autoinflammatory disease.
Stimulation of nicotinic acetylcholine receptors attenuates collagen‐induced arthritis in mice
Authors: van Maanen Marjolein A. , Lebre Maria C. , van der Poll Tom , LaRosa Gregory J. , Elbaum Daniel , Vervoordeldonk Margriet J. , Tak Paul P. 
Published: December 2008

AbstractObjectiveThe parasympathetic nervous system, through the vagus nerve, can down‐regulate inflammation in vivo by decreasing the release of cytokines, including tumor necrosis factor α (TNFα), by activated macrophages. The vagus nerve may exert antiinflammatory actions via a specific effect of its principal neurotransmitter, acetylcholine, on the α7 subunit of nicotinic acetylcholine receptors (α7nAChR) on macrophages. The present study was undertaken to obtain insight into the role of the cholinergic antiinflammatory pathway in arthritis.MethodsTo inhibit the cholinergic antiinflammatory pathway, mice were subjected to unilateral cervical vagotomy or sham surgery, after which arthritis was induced with type II collagen. In a separate study, nicotine was added to the drinking water of mice with collagen‐induced arthritis (CIA). In addition, we investigated the effects of intraperitoneally (IP)–injected nicotine and the specific α7nAChR agonist AR‐R17779.ResultsClinical arthritis was exacerbated by vagotomy and ameliorated by oral nicotine administration. Moreover, oral nicotine inhibited bone degradation and reduced TNFα expression in synovial tissue. Both IP‐injected nicotine and AR‐R17779 ameliorated clinical arthritis and reduced synovial inflammation. This was accompanied by a reduction of TNFα levels in both plasma and synovial tissue. The effect of AR‐R17779 was more potent compared with that of nicotine and was associated with delayed onset of the disease as well as with protection against joint destruction.ConclusionThese data provide the first evidence of a role of the cholinergic antiinflammatory pathway in the murine CIA model of rheumatoid arthritis.