bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of relaxations in poly(methyl methacrylate)–magneto electrets by thermally stimulated depolarization current and surface‐charge‐decay mechanisms
Authors: Tewari A. S. , Qureshi M. S. , Dubey R. N. , Malik M. M. 
Published: April 2011

AbstractThe effect of the forming temperature and the magnetic field was investigated for the charge retention and stability of poly(methyl methacrylate) (PMMA)–magneto electret (ME) samples with thermally stimulated discharge currents (TSDCs) and a surface‐charge‐decay mechanism. The measurements were performed on a pristine PMMA sample with a thickness of 20 mm. The comparative studies of charge decay with TSDC indicated a strong resemblance between the results of the two techniques of MEs of PMMA and were characterized by two TSDC peaks, that is, an α peak at 110°C and a ρ peak at 160°C. The low‐temperature peak (i.e., the α peak) was associated with dipolar relaxation, and the high‐temperature peak (i.e., the ρ peak) was attributed to the self‐motion of space charges in PMMA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Radiation‐induced effects in gamma‐irradiated PLLA and PCL at ambient and dry ice temperatures
Authors: Walo Marta , Przybytniak Grażyna , Nowicki Andrzej , Świeszkowski Wojciech 
Published: April 2011

AbstractThe effect of γ‐rays sterilization at ambient (23°C) and at dry ice temperatures (−78°C) on two biodegradable semicrystalline polyesters, namely poly(L‐lactide) (PLLA) and poly(ε‐caprolactone) (PCL), was studied. The radical processes generated by irradiation were investigated by electron paramagnetic resonance (EPR) spectroscopy, whereas postradiation changes were monitored for 5 months by scanning calorimetry, thermogravimetric analysis, and apparent viscosity measurements. It was confirmed that the radiation sterilization initiates degradation in both studied polymers, however, the effect is smaller in PCL than in PLLA, and that the range of changes might be limited by lowering temperature of the exposure to γ‐rays. Newly formed oxygen containing functional groups confirmed by EPR and thermogravimetric analysis methods are produced in the irradiated polyesters. In PCL, the process might give rise to thermally induced cross‐linking via oxygen containing intermolecular bridges. During storage, in both irradiated materials, morphology determined by differential scanning calorimetry is changing ‐ PCL ability toward crystallization decreases insignificantly, whereas in PLLA the tendency is opposite ‐ on irradiation a contribution of crystalline phase is growing considerably, from 18 and 19% to 41 and 31% for PLLA irradiated at 23°C and at −78°C, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Greater rates of cartilage loss in painful knees than in pain‐free knees after adjustment for radiographic disease stage: Data from the Osteoarthritis Initiative
Authors: Eckstein Felix , Cotofana Sebastian , Wirth Wolfgang , Nevitt Michael , John Markus R. , Dreher Donatus , Frobell Richard ,   Osteoarthritis Initiative Investigators Group
Published: April 2011

AbstractObjectiveTo investigate whether rates of cartilage loss differ in knees with frequent baseline pain versus those without pain, after adjustment for radiographic osteoarthritis (OA) stage.MethodsOne knee in each of 718 Osteoarthritis Initiative participants was examined: 310 with calculated Kellgren/Lawrence (K/L) grade 2, 299 with calculated K/L grade 3, and 109 with calculated K/L grade 4. Twelve‐month change in (subregional) cartilage thickness was assessed by magnetic resonance imaging. Change in cartilage thickness in the central subregion of the weight‐bearing medial femoral condyle and ordered value 1 (OV1) were selected as primary end points. Frequent knee symptoms were defined as pain, aching, or stiffness on most days of at least 1 month during the previous year.ResultsThe mean 12‐month rate of change in cartilage thickness in the central subregion of the medial femoral condyle was −12 μm (standardized response mean [SRM] −0.15) in knees without pain (n = 146), −27 μm (SRM −0.25) in those with infrequent pain (n = 255), and −54 μm (SRM −0.32) in those with frequent pain (n = 317). Rates differed significantly between frequently painful knees and pain‐free knees after adjustment for age, sex, body mass index, and calculated K/L grade (P = 0.011, R2 = 2.6%, partial R2 for frequent pain = 1.4%). Similar results were found in stratified samples of calculated K/L grade 2/calculated K/L grade 3 knees, and in analyses restricted to knees with consistent pain frequency between baseline and followup. OV1 results showed similar trends but were not significant.ConclusionKnees with frequent pain display greater rates of medial cartilage loss longitudinally than knees without pain, with or without adjustment or stratification for radiographic disease stage. Enrollment of participants with frequent knee pain in clinical trials can increase the observed rate of structural progression (i.e., cartilage loss) and sensitivity to change.
The relationship between oral contraceptive use and functional outcome in women with recent‐onset inflammatory polyarthritis: Results from the Norfolk Arthritis Register
Authors: Camacho E. M. , Lunt M. , Farragher T. M. , Verstappen S. M. M. , Bunn D. K. , Symmons D. P. M. 
Published: April 2011

AbstractObjectiveUse of oral contraceptives (OCs) may prevent the development of rheumatoid arthritis, but the influence of OC use on disease outcome is unresolved. The purpose of this study was to examine functional outcome and OC use in women with inflammatory polyarthritis (IP).MethodsThe Norfolk Arthritis Register (NOAR) is an inception cohort of patients with recent‐onset IP. We studied patient‐reported history of OC use in 663 women who were born after 1945 and who had not used OCs during followup. OC use during followup was additionally investigated in 265 women who were <50 years old and had not undergone menopause or hysterectomy during followup. All patients were recruited to the NOAR between 1990 and 2004. Functional ability was assessed using the Health Assessment Questionnaire (HAQ), with adjustment for age at symptom onset.ResultsThe median followup was 4.9 years. In the investigation analyzing OC use before symptom onset, patients who had used OCs before symptom onset had lower HAQ scores throughout followup than patients who had not taken OCs before symptom onset (difference in score at 5‐year followup −0.35; 95% confidence interval [95% CI] −0.51, −0.19). Patients who were taking OCs at baseline had lower HAQ scores over time than women who were not taking OCs at baseline but had previously done so (mean difference −0.21; 95% CI −0.40, −0.02). In the investigation analyzing OC use during followup, OC use during followup was associated with lower HAQ scores over time than no OC use during followup (mean difference −0.06; 95% CI −0.16, 0.03); however, this was only significant for women with moderate or severe functional disability at the previous assessment (mean difference −0.23; 95% CI −0.40, −0.07). Further adjustment for potential confounders and exclusion of hormone replacement therapy users had little impact.ConclusionOC use is generally associated with a beneficial functional outcome in IP, and use before and at symptom onset appeared to have the most consistent benefit.
Chemical reactors sequencing
Authors: Chebbi Rachid 
Published: April 2011

ABSTRACTThe procedure introduced, based on a mathematical approach, provides a systematic way of finding the sequencing of reactors in series providing the minimum total reactor volume. Using the proposed procedure along with Levenspiel graphical method provides both a systematic way of solving the sequencing problem and a visual interpretation of the results. Trial and error calculations are needed with standard methods to obtain conversions in cases reactor volumes are given. A method is available in the literature to determine the conversions in continuous stirred tank reactors (CSTRs) in series, given the CSTRs volumes. The direct method proposed eliminates the need for initial guesses and trial and error calculations for both PFRs and CSTRs, using newly defined plots. Detailed spreadsheet calculations are provided to illustrate the direct procedure for calculating conversions, given the reactors volumes in a sequence, whether the sequencing is optimum or not. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:195–199, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.20545
Highly integrated gradient pulse generator for magnetic resonance imaging system
Authors: Tang Weinan , Wang Weimin 
Published: April 2011

AbstractA gradient pulse generator for magnetic resonance imaging is presented. It has the ability to yield arbitrary gradient pulses on the fly and provide reconfigurable calculations including scaling, axis rotation, pre‐emphasis, and gradient offsetting in real time along X, Y, and Z gradient channels. The versatility has been obtained by incorporating all required digital functions into a single field programmable gate array chip. The development of the hardware is eased by employing a high‐level tool—the System Generator—using the MathWorks model‐based Simulink environment. In addition, an easy‐to‐use method is developed for pre‐emphasis calibration. As expected, the described device is highly integrated, low cost, simple to use and interface, and has been demonstrated successfully in conjunction with a home‐built magnetic resonance system to perform imaging experiments. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 39B: 59–63, 2011
A theoretical method for the use of a phantom to enhance image reconstruction in MRI
Authors: Forbes Lawrence K. , Brideson Michael A. , While Peter T. 
Published: April 2011

AbstractA simple technique is proposed in which a phantom could be used to calibrate an image acquired during an magnetic resonance imaging scan. The method corrects for the effects of nonlinearities in the gradient fields, and in principle does so exactly. The mathematics behind the technique is discussed, and a simple tutorial example is presented as an illustration. The technique is then tested on an actual (photographic) image, and it is shown to be able to recover much of the original picture, even in the presence of strongly nonlinear gradients. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 39B: 98–108, 2011
How visual space maps in the optic neuropils of a crab
Authors: De Astrada Martín Berón , Medan Violeta , Tomsic Daniel 
Published: April 2011

AbstractThe Decapoda is the largest order of crustaceans, some 10,000 species having been described to date. The order includes shrimps, lobsters, crayfishes, and crabs. Most of these are highly visual animals that display complex visually guided behaviors and, consequently, large areas of their nervous systems are dedicated to visual processing. However, our knowledge of the organization and functioning of the visual nervous system of these animals is still limited. Beneath the retina lie three serially arranged optic neuropils connected by two chiasmata. Here, we apply dye tracers in different areas of the retina or the optic neuropils to investigate the organization of visual space maps in the optic neuropils of the brachyuran crab Chasmagnathus granulatus. Our results reveal the way in which the visual space is represented in the three main optic neuropils of a decapod. We show that the crabs' optic chiasmata are oriented perpendicular to each other, an arrangement that seems to be unique among malacostracans. Crabs use retinal position in azimuth and elevation to categorize visual stimuli; for instance, stimuli moving above or below the horizon are interpreted as predators or conspecifics, respectively. The retinotopic maps revealed in the present study create the possibility of relating particular regions of the optic neuropils with distinct behavioral responses elicited by stimuli occurring in different regions of the visual field. J. Comp. Neurol. 519:1631–1639, 2011. © 2011 Wiley‐Liss, Inc.
The hepcidin circuits act: Balancing iron and inflammation
Authors: Maliken Bryan D. , Nelson James E. , Kowdley Kris V. 
Published: April 2011

Abstract

Hepcidin is a peptide hormone that regulates iron homeostasis and acts as an antimicrobial peptide. It is expressed and secreted by a variety of cell types in response to iron loading and inflammation. Hepcidin mediates iron homeostasis by binding to the iron exporter ferroportin, inducing its internalization and degradation via activation of the protein kinase Jak2 and the subsequent phosphorylation of ferroportin. Here we have shown that hepcidin-activated Jak2 also phosphorylates the transcription factor Stat3, resulting in a transcriptional response. Hepcidin treatment of ferroportin-expressing mouse macrophages showed changes in mRNA expression levels of a wide variety of genes. The changes in transcript levels for half of these genes were a direct effect of hepcidin, as shown by cycloheximide insensitivity, and dependent on the presence of Stat3. Hepcidin-mediated transcriptional changes modulated LPS-induced transcription in both cultured macrophages and in vivo mouse models, as demonstrated by suppression of IL-6 and TNF-α transcript and secreted protein. Hepcidin-mediated transcription in mice also suppressed toxicity and morbidity due to single doses of LPS, poly(I:C), and turpentine, which is used to model chronic inflammatory disease. Most notably, we demonstrated that hepcidin pretreatment protected mice from a lethal dose of LPS and that hepcidin-knockout mice could be rescued from LPS toxicity by injection of hepcidin. The results of our study suggest a new function for hepcidin in modulating acute inflammatory responses. (HEPATOLOGY 2011 )
How We know it when we see it: Conceptualizing and assessing integrative and applied learning‐in‐use
Authors: Mentkowski Marcia , Sharkey Stephen 
Published: April 2011

AbstractWe examine the concept of integrative and applied learning from various perspectives, emphasize transfer of that learning to unfamiliar and unimagined settings, and describe crucial metacognitive strategies, including learned abilities used as frameworks for performance, reflection, and self‐assessment that foster learning that lasts. We follow with examples of Alverno approaches for assessing these complex capacities across a curriculum.
Analysis of carriers of hepatitis B virus from a tertiary referral hospital: Does the viral load change during the natural course of infection?
Authors: Aakanksha  , Asim Mohammad , Sharma P.K. , Das B.C. , Kar P. 
Published: April 2011

AbstractThis study was designed to determine the prevalence, forms of transmission, mutational profile and viral load at baseline of hepatitis B virus (HBV) carriers in Delhi. HBV surface antigen (HBsAg)‐positive patients were enrolled and evaluated clinically for liver function, serological markers for hepatitis B and HBV DNA quantitation. Tests were carried out again 1 year later and the results were compared. Liver biopsy was carried out on all carriers with active viral replication. HBV DNA‐positive samples were subjected to polymerase chain reaction single‐stranded conformation polymorphism (PCR‐SSCP) to screen mutations in the Precore, core, and the X‐gene prior to sequencing analysis. Among the 100 patients examined, HBeAg was detected in 23% and 40% were HBV DNA‐positive. Of the 40 HBV DNA‐positive cases, 8 had precore/core mutations, [G1896A (10%), T2066A (12.5%), T2050C (10%), and G1888A (7.5%)]. No X gene mutants were detected. Reduction in viral load was higher in HBeAg‐positive patients, as compared to HBeAg‐negative patients, over 1 year. At follow‐up, 2/8 HBV mutants corresponded with altered liver function and morphological changes suggestive of chronic hepatitis. One patient was re‐designated as DNA‐negative on follow‐up and had wild‐type virus infection with a relatively low viral load. The predominant route for HBV transmission was determined to be parenteral. Twenty percent of the HBV carriers were infected with precore and core mutant HBV. Although the clinical and biochemical profiles of these HBV carriers remained largely stable on follow‐up, there was evidence of spontaneous reduction in the mean viral load over the 1‐year study period. J. Med. Virol. 83:1151–1158, 2011. © 2011 Wiley‐Liss, Inc.
Antigenic and genetic variation in the hemagglutinins of H1N1 and H3N2 human influenza a viruses in the Shanghai area from 2005 to 2008
Authors: Ren Xiao‐wei , Ju Li‐wen , Yang Ji‐xing , Lv Xi‐hong , Jiang Lu‐fang , Zhao Nai‐qing , Jiang Qing‐wu 
Published: April 2011

AbstractContinued rapid evolution of the influenza A virus is responsible for annual epidemics and occasional pandemics in the Shanghai area. In the present study, the representative strains of A/H1N1 and A/H3N2 influenza viruses isolated in the Shanghai area from 2005 to 2008 were antigenically and genetically characterized. The antigenic cartography method was carried out to visualize the hemagglutination‐inhibition data. Antigenic differences were detected between circulating A/H1N1 strains isolated from 2005 to 2006 and the epidemic A/H1N1 strains isolated in 2008, which were found to be associated with the amino acid substitution K140E in HA1. The present vaccine strain A/Brisbane/59/2007 is considered to be capable of providing sufficient immunity against most of the circulating A/H1N1 viruses isolated in 2008 from the Shanghai population. The study showed that there were significant antigenic differences between the epidemic A/H3N2 strains isolated in 2007 and 2008, suggesting that antigenic drift had occurred in the A/H3N2 strains isolated in 2008. The P194L mutation was thought to be responsible for the antigenic evolution of influenza A/H3N2 viruses isolated from Shanghai in 2008. Evidence of antigenic drift suggests that the influenza A/H3N2 vaccine component needs to be updated. J. Med. Virol. 83:1113–1120, 2011. © 2011 Wiley‐Liss, Inc.
Sexual behavior and HPV infection in British women, by postal questionnaires and telephone interviews
Authors: Almonte Maribel , Silva Isabel dos Santos , Asare Akua , Gilham Clare , Sargent Alexandra , Bailey Andrew , Turner Andrew , Desai Mina , Kitchener Henry C. , Peto Julian 
Published: April 2011

AbstractSexually transmitted human papillomaviruses (HPVs), most frequently HPV 16, are the primary cause of cervical carcinogenesis. The aim of this study was to evaluate the relationship between sexual behavior and prevalence and acquisition of HPV infection among British women attending regular cervical screening who responded to postal questionnaires and/or telephone interviews. A total of 1,880 women who had been tested for HPV in the ARTISTIC (A Randomized Trial In Screening To Improve Cytology) trial were randomized to three methods of data collection: group 1 (questionnaire including sexual history, no interview), group 2 (questionnaire excluding sexual history, short interview including sexual history), and group 3 (questionnaire and long interview including sexual history in both). Questions on sexual history included age at first sexual intercourse, sexually transmitted diseases, lifetime (total and regular) sexual partners, and number of partners in the last 5 years (total and new). Demographics, reproductive, cervical screening, and smoking history were also collected in questionnaires. The overall participation rate was 35%. There was good agreement (87.4–95.5%) on sexual behavior answers in questionnaires and interviews in women in group 3 and no significant differences between data obtained by questionnaire or interview. Odds ratios (OR) for both HPV prevalence and acquisition increased consistently with increasing numbers of lifetime sexual partners, regular partners, and new partners in the last 5 years (recent partners). No significant association was found for other characteristics investigated. The effect of recent sexual partners on HPV acquisition (OR for 2+ recent partners: 4.4, 95% CI: 1.7–11.2) was stronger than that of earlier (>5 years ago) partners (OR for 2+ earlier partners: 2.2, 95% CI: 0.7–6.7) suggesting that most incident HPV infections are newly acquired rather than recurrent. J. Med. Virol. 83:1238–1246, 2011. © 2011 Wiley‐Liss, Inc.
Evidence for positive selection in the extracellular domain of human cytomegalovirus encoded G protein‐coupled receptor US28
Authors: Gong Xiaoyan , Padhi Abinash 
Published: April 2011

AbstractThe human cytomegalovirus (HCMV)‐encoded chemokine receptor US28 is also a seven‐transmembrane G‐protein coupled receptor, whose signaling pathway is known for its involvement in host immune system evasion. HCMV infection can result in serious disease in immunocompromised individuals and is also linked to atherosclerosis and cardiovascular disease. Identifying amino acid residues that play a crucial role in successful viral adaptation in response to the host's immune defense is critical for effective drug design. In this study maximum likelihood‐based codon substitution analyses were carried out to determine whether any codon of US28 has evolved adaptively. If the rate of nonsynonymous (dn) to the rate of synonymous (ds) nucleotide substitutions (ω = dn/ds) is greater than one, the codon is said to be under positive selection, indicating adaptive evolution. Although the overall ω for US28 gene was 0.154, indicating that most codon sites were subject to strong purifying selection, five codon sites are under strong positive selection. Three (E18D/L, D19A/E/G, and R267K/Q) of these positively selected sites are located in extracellular domains, the domains that play a crucial role for successful viral adaptation in response to the host's immune defense. The C‐terminal (R329Q/W) and the fifth transmembrane domain (V190I), each have one positively selected site. These results suggest that relative to the extracellular domains, amino acid residues present in intracellular domains are more selectively constrained. A few amino acid residues in extracellular domains of US28 evolved more rapidly, presumably due to positive selection pressure resulting from ligand‐binding and pathogen interactions of extracellular domains. J. Med. Virol. 83:1255–1261, 2011. © 2011 Wiley‐Liss, Inc.