bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical stability of high‐molecular‐weight polyacrylamides and an (acrylamido tert‐butyl sulfonic acid)–acrylamide copolymer used in enhanced oil recovery
Authors: Al‐Hashmi Abdul‐Aziz , Al‐Maamari Rashid , Al‐Shabibi Ibtisam , Mansoor Ahmed , Al‐Sharji Hamed , Zaitoun Alain 
Published: May 2014

ABSTRACTHigh‐molecular‐weight partially hydrolyzed and sulfonated polyacrylamides are widely used in enhanced oil recovery (EOR). Nonionic polyacrylamide and polyacrylamide‐based microgels are also used in water shut‐off treatments for gas and oil wells. A comparative study of the mechanical degradation for three linear polyacrylamides and a microgel is presented. Mechanical degradation is quantified from the loss of the viscosity of the polymer solution as it passes through a stainless steel capillary with a length of 10 cm and an internal diameter of 125 µm. The critical shear rate above which degradation increases exponentially was found to depend on the chemical structure of the polymer, molecular weight, and electrolyte strength. The nonionic polyacrylamide shows higher degradation and lower critical shear rate compared with a sulfonated polyacrylamide with similar molecular weight. Moreover, the nonionic polyacrylamide with a higher molecular weight results in lower mechanical degradation. The higher mechanical stability of the sulfonated polymer is attributed to the higher rigidity of its molecules in solution. On the other hand, the ability of the high‐molecular‐weight polymers to form transient, flow‐induced microgels boost their mechanical stability. This ability increases with the increase in the molecular weight of the polymer. Indeed, the microgel solution used in this study demonstrates exceptional mechanical stability. In general, mechanical stability of linear polymers used in chemical enhanced oil recovery can be enhanced by tailoring a polymer that has large side groups similar to the sulfonated polyacrylamide. Also, polyacrylamide‐based microgels can be applied if high mechanical stability is required. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40921.
Effects of TMPTMA and silane on the compressive strength of low‐temperature cured acrylic polymer concrete
Authors: Yeon Kyu‐Seok , Cha Jin‐Yun , Yeon Jung Heum , Seung In Bae 
Published: May 2014

ABSTRACTThis study addresses the effects of additives on the compressive strength of low‐temperature cured acrylic polymer concrete (PC). Three curing temperatures (0°C, −10°C, and −20°C) and five ages (6, 12, 24, 72, and 168 h) with two different types of additives [trimethylolpropane trimethacrylate (TMPTMA) and silane] were investigated. As a result, the compressive strength tended to decrease as the curing temperature decreased. The compressive strengths at 24 h were approximately 90% of those at 168 h at both curing temperatures of 0°C and −20°C, indicating that the rate of early age strength development was quite high even at a very low curing temperature range. The results of two‐way variance analysis revealed that silane had a greater impact on the compressive strength than TMPTMA. About 13%–23% strength improvements with a 168‐h compressive strength of over 80 MPa could be obtained at −20°C by adding silane. Furthermore, this study proposed optimum mixture proportions of acrylic PC that generate a working life of 50–70 minutes with a compressive strength of 80 MPa at subzero temperatures. The findings of this study are expected to be effectively used in field applications of acrylic PC, especially in the cold regions during winter season. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40939.
Enhanced piezoelectric responses and crystalline arrangement of electroactive polyvinylidene fluoride/magnetite nanocomposites
Authors: Ouyang Zen‐Wei , Chen Erh‐Chiang , Wu Tzong‐Ming 
Published: May 2014

ABSTRACTThe well distributed and electroactive polyvinylidene fluoride (PVDF)/magnetite nanocomposites were successfully fabricated using a mixed solvent system (THF/DMF). Dynamic mechanical properties of the fabricated PVDF/magnetite nanocomposites indicate significant enhancements in the storage modulus as compared with that of neat PVDF. By adding 2 wt % magnetite nanoparticles into the PVDF matrix, the thermal stability of nanocomposites could be enhanced about 26°C as compared with that of PVDF. The β‐phase fraction of PVDF is significantly enhanced with increasing the voltage of electric field poling. The piezoelectric responses of PVDF/magnetite films are extensively increased about five times in magnitude with applied strength of electrical field at 35 MV/m. The change of piezoelectric responses during the applied electric field may be due to the relative long arrangement of PVDF units along the direction of electric field poling and thus increases the values of Lp* and lc. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40941.
Randomized, Double‐Blind, Placebo‐Controlled Trial of the Efficacy and Safety of Rilonacept in the Treatment of Systemic Juvenile Idiopathic Arthritis
Authors: Ilowite Norman T. , Prather Kristi , Lokhnygina Yuliya , Schanberg Laura E. , Elder Melissa , Milojevic Diana , Verbsky James W. , Spalding Steven J. , Kimura Yukiko , Imundo Lisa F. , Punaro Marilynn G. , Sherry David D. , Tarvin Stacey E. , Zemel Lawrence S. , Birmingham James D. , Gottlieb Beth S. , Miller Michael L. , O'Neil Kathleen , Ruth Natasha M. , Wallace Carol A. , Singer Nora G. , Sandborg Christy I. 
Published: May 2014

ObjectiveTo assess the efficacy and safety of rilonacept, an interleukin‐1 inhibitor, in a randomized, double‐blind, placebo‐controlled trial.MethodsAn initial 4‐week double‐blind placebo phase was incorporated into a 24‐week randomized multicenter design, followed by an open‐label phase. Seventy‐one children who had active arthritis in ≥2 joints were randomized (1:1) to the 2 arms of the study. Patients in the rilonacept arm received rilonacept (loading dose 4.4 mg/kg followed by 2.2 mg/kg weekly, subcutaneously) beginning on day 0. Patients in the placebo arm received placebo for 4 weeks followed by a loading dose of rilonacept at week 4 followed by weekly maintenance doses. The primary end point was time to response, using the adapted American College of Rheumatology Pediatric 30 criteria coupled with the absence of fever and taper of the dosage of systemic corticosteroids, using prespecified criteria.ResultsThe time to response was shorter in the rilonacept arm than in the placebo arm (χ2 = 7.235, P = 0.007). The secondary analysis, which used the same response criteria, showed that 20 (57%) of 35 patients in the rilonacept arm had a response at week 4 compared with 9 (27%) of 33 patients in the placebo arm (P = 0.016). Exacerbation of systemic juvenile idiopathic arthritis (JIA) was the most common severe adverse event. More patients in the rilonacept arm had elevated liver transaminase levels (including levels more than 3 times the upper limit of normal) compared with those in the placebo arm. Adverse events were similar in the 2 arms of the study.ConclusionRilonacept was generally well tolerated and demonstrated efficacy in active systemic JIA.
New Evidence Implicating 4‐Hydroxynonenal in the Pathogenesis of Osteoarthritis In Vivo
Authors: Shi Qin , Abusarah Jamilah , Zaouter Charlotte , Moldovan Florina , Fernandes Julio C. , Fahmi Hassan , Benderdour Mohamed 
Published: May 2014

ObjectiveTo demonstrate the involvement of 4‐hydroxynonenal (HNE), a very reactive aldehyde derived from lipid peroxidation, in the pathogenesis of osteoarthritis (OA) in vivo.MethodsIn the first experimental protocol, OA was induced by anterior cruciate ligament transection (ACLT) of the right knees of crossbred dogs (n = 6 per group). The animals were treated with placebo or HNE‐trapping carnosine (5 or 20 mg/kg/day) orally for 8 weeks. Another group of dogs was treated for 4 weeks with 20 mg/kg/day of carnosine starting 4 weeks after surgery. Sham‐operated dogs served as controls. In the second experimental protocol, a pathophysiologic dose of HNE (80 nmoles/ml) or vehicle was injected weekly into the right knee joints of crossbred dogs (n = 6 per group) for 8 weeks. Articular cartilage was subjected to macroscopic, histomorphologic, and immunohistochemical analyses. Cartilage‐degrading enzymes and oxidative stress–related products were assessed in synovial fluid and cartilage explants. Markers of inflammation were evaluated in synovium and synovial fluid.ResultsIn dogs that had undergone ACLT, carnosine treatment reduced the severity and histopathology score of OA cartilage lesions and also decreased HNE–protein adducts, pentosidine, nitrosylated proteins, cartilage‐degrading enzymes, and markers of inflammation. Intraarticular injection of HNE induced cartilage lesions, as assessed by macroscopic and microscopic criteria. Cartilage‐degrading enzymes and markers of inflammation increased in HNE‐treated dogs.ConclusionThis is the first in vivo study to demonstrate the pathophysiologic role of HNE in OA. That carnosine abolishes HNE production and a number of factors known to be involved in OA pathogenesis renders it a clinically valuable agent in prevention of the disease.
Brief Report: Rheumatoid Arthritis Response Criteria and Patient‐Reported Improvement in Arthritis Activity: Is an American College of Rheumatology Twenty Percent Response Meaningful to Patients?
Authors: Ward Michael M. , Guthrie Lori C. , Alba Maria I. 
Published: May 2014

ObjectiveTo examine the association of the American College of Rheumatology (ACR) response criteria (20% improvement [ACR20], ACR50, and ACR70) and the European League Against Rheumatism (EULAR) response criteria with patient‐reported improvement in rheumatoid arthritis (RA) activity.MethodsTwo hundred fifty patients with active RA were studied prospectively, before and after escalation of antirheumatic treatment. Patients were asked to report if they subjectively judged that they had experienced important improvement with treatment, and the proportion of patients who reported improvement was compared with the proportion who met the ACR20, ACR50, ACR70, and EULAR response criteria.ResultsImprovement in overall arthritis status was reported by 167 patients (66.8%), while 107 patients (42.8%) had an ACR20 response, 52 (20.8%) had an ACR50 response, 24 (9.6%) had an ACR70 response, and 136 (54.4%) had a EULAR moderate/good response. ACR20 response had a sensitivity of 0.57 and a specificity of 0.85 for clinically important improvement as judged by patients. Sensitivities of the ACR50, ACR70, and EULAR moderate/good responses were 0.30, 0.14, and 0.68, respectively, while their specificities were 0.97, 0.99, and 0.73, respectively. The ACR hybrid score with the highest sensitivity and specificity for important improvement was 19.99.ConclusionAmong patients with active RA, ACR20 responses are highly specific measures of improvement as judged by patients, but exclude a substantial proportion of patients who consider themselves improved. Response criteria are associated with, but not equivalent to, patient‐perceived improvement.
Characterization of the Cartilage DNA Methylome in Knee and Hip Osteoarthritis
Authors: Rushton Michael D. , Reynard Louise N. , Barter Matt J. , Refaie Ramsay , Rankin Kenneth S. , Young David A. , Loughlin John 
Published: May 2014

ObjectiveThe aim of this study was to characterize the genome‐wide DNA methylation profile of chondrocytes from knee and hip cartilage obtained from patients with osteoarthritis (OA) and hip cartilage obtained from patients with femoral neck fracture, providing the first comparison of DNA methylation between OA and non‐OA hip cartilage, and between OA hip and OA knee cartilage.MethodsThe study was performed using the Illumina Infinium HumanMethylation450 BeadChip array, which allows the annotation of ∼480,000 CpG sites. Genome‐wide methylation was assessed in chondrocyte DNA extracted from 23 hip OA patients, 73 knee OA patients, and 21 healthy hip control patients with femoral neck fracture.ResultsAnalysis revealed that chondrocytes from the hip cartilage of OA patients and healthy controls have unique methylation profiles, with 5,322 differentially methylated loci (DMLs) identified between the 2 groups. In addition, a comparison between hip and knee OA chondrocytes revealed 5,547 DMLs between the 2 groups, including DMLs in several genes known to be involved in the pathogenesis of OA. Hip OA samples were found to cluster into 2 groups. A total of 15,239 DMLs were identified between the 2 clusters, with an enrichment of genes involved in inflammation and immunity. Similarly, we confirmed a previous report of knee OA samples that also clustered into 2 groups.ConclusionWe demonstrated that global DNA methylation using a high‐density array can be a powerful tool in the characterization of OA at the molecular level. Identification of pathways enriched in DMLs between OA and OA‐free cartilage highlight potential etiologic mechanisms that are involved in the initiation and/or progression of the disease and that could be therapeutically targeted.
Fault Detection for Networked Systems with Partly Known Distribution Transmission Delays
Authors: Wang Yanqian , Zhang Shuyu , Lu Junwei , Chen Fu 
Published: May 2014

AbstractIn this paper, the fault detection problem for networked systems with partly known distribution transmission delays is studied. Network‐induced delays are modeled as a homogeneous Markov chain, which takes values in a finite state space. By constructing an augmented system, which consists of the states of the original system and the fault detection filter (FDF), fault detection for networked systems can be formulated as an H∞ filtering problem of a Markov jump system. A sufficient condition for the existence of the desired FDF is obtained, based on certain feasible linear matrix inequalities.
Integration of host strain bioengineering and bioprocess development using ultra‐scale down studies to select the optimum combination: An antibody fragment primary recovery case study
Authors: Aucamp Jean P. , Davies Richard , Hallet Damien , Weiss Amanda , Titchener‐Hooker Nigel J. 
Published: May 2014

ABSTRACTAn ultra scale‐down primary recovery sequence was established for a platform E. coli Fab production process. It was used to evaluate the process robustness of various bioengineered strains. Centrifugal discharge in the initial dewatering stage was determined to be the major cause of cell breakage. The ability of cells to resist breakage was dependant on a combination of factors including host strain, vector, and fermentation strategy. Periplasmic extraction studies were conducted in shake flasks and it was demonstrated that key performance parameters such as Fab titre and nucleic acid concentrations were mimicked. The shake flask system also captured particle aggregation effects seen in a large scale stirred vessel, reproducing the fine particle size distribution that impacts the final centrifugal clarification stage. The use of scale‐down primary recovery process sequences can be used to screen a larger number of engineered strains. This can lead to closer integration with and better feedback between strain development, fermentation development, and primary recovery studies. Biotechnol. Bioeng. 2014;111: 1971–1981. © 2014 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.
Collaborative virtual training with physical and communicative autonomous agents
Authors: Lopez Thomas , Chevaillier Pierre , Gouranton Valérie , Evrard Paul , Nouviale Florian , Barange Mukesh , Bouville Rozenn , Arnaldi Bruno 
Published: May 2014

ABSTRACTVirtual agents are a real asset in collaborative virtual environment for training (CVET) as they can replace missing team members. Collaboration between such agents and users, however, is generally limited. We present here a whole integrated model of CVET focusing on the abstraction of the real or virtual nature of the actor to define a homogenous collaboration model. First, we define a new collaborative model of interaction. This model notably allows to abstract the real or virtual nature of a teammate. Moreover, we propose a new role exchange approach so that actors can swap their roles during training. The model also permits the use of physically based objects and characters animation to increase the realism of the world. Second, we design a new communicative agent model, which aims at improving collaboration with other actors using dialog to coordinate their actions and to share their knowledge. Finally, we evaluated the proposed model to estimate the resulting benefits for the users and we show that this is integrated in existing CVET applications. Copyright © 2014 John Wiley & Sons, Ltd.
Bulging‐free dual quaternion skinning
Authors: Kim YoungBeom , Han JungHyun 
Published: May 2014

ABSTRACTThe linear blend skinning has been the most popular skeletal animation algorithm and also notorious for the collapsing‐joint and candy‐wrapper artifacts. The dual quaternion skinning (DQS) successfully resolves the problems, but it reveals its own artifacts, which we name bulging joint and distorted normal. We propose to post‐process the DQS algorithm; the bulging‐joint artifact can be removed by correcting the vertex positions, and the distorted‐normal artifact can be removed by correcting the vertex normals. The proposed method is simple yet quite effective. The experimental results show that the skinning animation quality is significantly improved. Copyright © 2014 John Wiley & Sons, Ltd.
Unusual Temperature‐Induced Retention Behavior of Constrained β‐Amino Acid Enantiomers on the Zwitterionic Chiral Stationary Phases ZWIX(+) and ZWIX(–)
Authors: Ilisz István , Pataj Zoltán , Gecse Zsanett , Szakonyi Zsolt , Fülöp Ferenc , Lindner Wolfgang , Péter Antal 
Published: May 2014

ABSTRACTThe effects of temperature on the chiral recognition of cyclic β‐amino acid enantiomers on zwitterionic [Chiralpak ZWIX(+) and ZWIX(–)] chiral stationary phases were investigated. Experiments were performed at different mobile phase compositions and under 10°C column temperature increments in the temperature range 10–50°C. Apparent thermodynamic parameters and Tiso values were calculated from plots of ln k and ln α versus 1/T, respectively. Unusual temperature behavior was observed, especially on the ZWIX(–) column, where the application of MeOH/MeCN (50/50 v/v) containing 25 mM triethylamine and 50 mM formic acid as mobile phase led to nonlinear van't Hoff plots and increasing retention time with increasing temperature. On both columns, both enthalpically and entropically driven separations were observed. Chirality 26:385–393, 2014. © 2014 Wiley Periodicals, Inc.
Application of Maltodextrin as Chiral Selector in Capillary Electrophoresis for Quantification of Amlodipine Enantiomers in Commercial Tablets
Authors: Nojavan Saeed , Pourmoslemi Shabnam , Behdad Hamideh , Fakhari Ali Reza , Mohammadi Ali 
Published: May 2014

ABSTRACTMaltodextrin was investigated as a chiral selector in capillary electrophoresis (CE) analysis of amlodipine (AM) enantiomers. For development of a stereoselective CE method, various effective parameters on the enantioseparation were optimized. The best results were achieved on an uncoated fused silica capillary at 20 °C using phosphate buffer (100 mM, pH 4) containing 10% w/v maltodextrin (dextrose equivalent value 4–7). The UV detector was set at 214 nm and a constant voltage of 20 kV was applied. The range of quantitation was 2.5–250 µg/mL (R2 > 0.999) for both enantiomers. Intra‐ (n = 5) and interday (n = 3) relative standard deviation (RSD) values were less than 7%. The limits of quantitation and detection were 1.7 µg/mL and 0.52 µg/mL, respectively. Recoveries of R(+) and S(−) enantiomers from tablet matrix were 97.2% and 97.8%, respectively. The method was applied for the quantification of AM enantiomers in commercial tablets. Also, the enantioseparation capability of heparin was evaluated and the results showed that heparin did not have any chiral selector activity in this study. Chirality 26:394–399, 2014. © 2014 Wiley Periodicals, Inc.
Internal Representations of the Therapeutic Relationship Among Adolescents in Psychodynamic Psychotherapy
Authors: Atzil‐Slonim Dana , Tishby Orya , Shefler Gaby 
Published: May 2014

This study examined changes in adolescents' internal representations of their relationship with their therapist and the extent to which these changes were related to changes in their representations of their relationship with their parents and to treatment outcomes.MethodThirty adolescents (aged 15–18 years, 70% women) undergoing psychodynamic psychotherapy participated in relationship anecdote paradigms interviews based on the core conflictual relationship theme method and completed outcome measures at the beginning of treatment and a year later.ResultsAdolescents' positive representations of their therapists increased throughout the year of treatment, whereas their negative representations did not change. There was an association between the development of the therapeutic relationship and improvement in the perception of the relationship with parents over the course of therapy. Increases in the level of positive representations and decreases in the level of negative representations of the therapist were associated with greater satisfaction with treatment but not with the other outcome measures. These results support the centrality of the therapeutic relationship in the process of change during adolescents' psychodynamic psychotherapy. Copyright © 2014 John Wiley & Sons, Ltd.Key Practitioner Message

The finding that positive representations of the therapist increased throughout treatment but that negative representations remained steady suggests that therapists who treat adolescents should expect and be able to hear adolescent clients' positive and negative internal representations of themselves. Therapists need to realize that although adolescents often experience negative emotions and perceptions in therapy as in other significant relationships, this does not necessarily block the development of positive emotions.
The finding that changes in the representations of the therapist are associated with changes in the representations of parents is in line with psychodynamic theory, which posits that psychotherapy facilitates new interpersonal experiences and new insights through the exploration of the therapeutic relationship. Working in the ‘here and now’ may eventually impact the nature of other significant relationships, particularly with parents in the case of adolescents.