bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Dissolved Iron and Oxygen on Stability of Hydrolyzed Polyacrylamide Polymers
Authors: Seright R.S.. S. , Skjevrak Ingun 
Published: January 2015

Summary
This paper describes an experimental study of the stability of a hydrolyzed polyacrylamide (HPAM) polymer and an HPAM-2-acrylamido-tertbutylsulfonic acid (ATBS) terpolymer in the presence of varying initial levels of dissolved oxygen (0 to 8,000 ppb), Fe2+ (0 to 220 ppm), and Fe3+ (0 to 172 ppm). A special method was developed to attain and confirm dissolved-oxygen levels. Stability studies were performed at 23 and 90°C. For Fe2+ concentrations between 0 and 30 ppm, viscosity losses were insignificant after 1 week when the initial dissolved oxygen concentration was 200 ppb or less. Above this level, significant viscosity losses were seen, especially if iron was present.
If the temperature is high, a greater need arises to strive for very low dissolved-oxygen content. For samples stored for 1 week at 90°C with only 10-ppb initial dissolved oxygen, contact with steel caused HPAM-ATBS solution viscosity losses greater than 30%. In contrast at 23°C, contact with steel caused no significant degradation when the dissolved O2 concentration was 1,000 ppb or less. Several different methods are discussed to control oxidative degradation of polymers during field applications. We advocate physical means of excluding oxygen (e.g., stopping leaks, better design of fluid transfer, gas-blanketing, gas-stripping) rather than chemical means.
Addition of Fe3+ to polymer solutions caused immediate crosslinking. Because crosslinked polymers were never observed during our studies with Fe2+, we conclude that free Fe3+ was not generated in sufficient quantities to form a visible gel.
Strategic Informed Trades, Diversification, and Expected Returns
Authors: Caskey Judson , Hughes John S. , Liu Jun 
Published: January 2015

ABSTRACT
We examine how strategic trade affects expected returns in a large economy. In our model, both a monopolist (strategic) informed trader and uninformed traders consider the impact of their demands on prices. In contrast to settings with price-taking traders, private information never eliminates a priced risk, and can lead to higher risk premiums. Also unlike settings with price-taking informed traders, risk premiums decrease in response to an increase in liquidity-motivated trades in diversified portfolios. These differing effects arise because a privately informed strategic trader conceals her trades by taking small positions relative to the magnitude of noise trades. Although prices partially reveal her information and reduce uncertainty, a concomitant decrease in her risk absorption dominates and leads to higher risk premiums. Similar to settings with price-taking traders, private information affects expected returns only via factor loadings and risk premiums on existing payoff risks—it introduces no new priced risks, and factor loadings (betas) explain all cross-sectional differences in expected returns.
CEO Contractual Protection and Managerial Short-Termism
Authors: Chen Xia , Cheng Qiang , Lo Alvis K. , Wang Xin 
Published: January 2015

ABSTRACT
How to address managerial short-termism is an important issue for companies, regulators, and researchers. We examine the effect of CEO contractual protection, in the form of employment agreements and severance pay agreements, on managerial short-termism. We find that firms with CEO contractual protection are less likely to cut R&D expenditures to avoid earnings decreases and are less likely to engage in real earnings management. The effect of CEO contractual protection is both statistically and economically significant. We further find that this effect increases with the duration and monetary strength of CEO contractual protection. The cross-sectional analyses indicate that the effect is stronger for firms in more homogeneous industries and for firms with higher transient institutional ownership, as protection is particularly important for CEOs in these firms, and is stronger when there are weaker alternative monitoring mechanisms.
JEL Classifications: G32; M40
On Experimental Thermal Analysis of Solid Materials
Authors: Koštial Pavel , Špička Ivo , Jančikova Zora , Valiček Jan , Harničarova Marta , Hlinka Josef 
Published: January 2015

Abstract
The paper is devoted to the presentation of a method for measurement of thermal conductivity k, specific heat capacity cp, and thermal diffusivity applying the lumped capacitance model (LCM) as a special case of Newton’s model of cooling. At the specific experimental conditions resulting from the theoretical analysis of the used model, we present a method for experimental determination of all three above mentioned thermal parameters for materials with different thermal transport properties. The input experimental data provide a cooling curve of the tested material. The evaluation of experimental data is realized by software, the fundamental features of which are presented here. The statistical analysis of experimental data was performed.
A New Compensation Method for Measurement of Thread Pitch Diameter by Profile Scanning
Authors: Sheng Chen , Dongbiao Zhao , Yonghua Lu 
Published: January 2015

Abstract
For measurement of existing thread parameters using profile scanning, system error increases as pitch diameter, difference between the calibrating thread and measuring thread increases with the single gauge calibration method. There are several alignment deviations affecting the measurement of pitch diameter. To reduce the system error, a compensation method using two standard thread gauges to calculate the alignment deviations is proposed here. Finally, the theoretical and experimental comparisons between the single gauge calibration method and the proposed method are presented. The results demonstrate that the two gauges calibration method can effectively reduce the system error.
Frequency Synchronization Analysis in Digital lock-in Methods for Bio-impedance Determination
Authors: Brajkovič Robert , Žagar Tomaž , Križaj Dejan 
Published: January 2015

Abstract
The lock-in method is one of the most frequently used methods for reconstruction of measured signals and as such frequently applied in the (bio)impedance method to determine the modulus and phase of the (bio)impedance. In implementation of the method in a (bio)impedance measurement device one has to consider possible non synchronized frequencies of the reference and the analyzed signals as well as potential sources of noise. In this work we analyzed these errors theoretically and experimentally. We show that both amplitude and phase errors depend on the relative difference of the frequencies of the reference and investigated signal as well as the number of integration periods. Theoretically, these errors vanish during the determination of the (bio)impedance modulus and phase. In practical implementation the inaccuracies appear at points of very low determined signal amplitudes due to the limited accuracy of analog to digital converters and are distributed around these points due to other sources of noise inherent in implementation of the measurement device.
Two New Sliding DTFT Algorithms for Phase Difference Measurement Based on a New Kind of Windows
Authors: Tu Yaqing , Shen Ting’ao , Zhang Haitao , Li Ming 
Published: January 2015

Abstract
For the ultra-low frequency signals or adjacent Nyquist frequency signals, which exist in the vibration engineering domain, the traditional DTFT-based algorithm shows serious bias for phase difference measurement. It is indicated that the spectrum leakage and negative frequency contribution are the essential causes of the bias. In order to improve the phase difference measurement accuracy of the DTFT-based algorithm, two new sliding DTFT algorithms for phase difference measurement based on a new kind of windows are proposed, respectively. Firstly, the new kind of windows developed by convolving conventional rectangular windows is introduced, which obtains a stronger inhibition of spectrum leakage. Then, with negative frequency contribution considered, two new formulas for phase difference calculation under the new kind of windows are derived in detail. Finally, the idea of sliding recursive is proposed to decrease the computational load. The proposed algorithms are easy to be realized and have a higher accuracy than the traditional DTFT-based algorithm. Simulations and engineering applications verified the feasibility and effectiveness of the proposed algorithms.
Intranasal Steroids and the Myth of Mucosal Atrophy: A Systematic Review of Original Histological Assessments
Authors: Verkerk Misha M. , Bhatia Daman , Rimmer Janet , Earls Peter , Sacks Raymond , Harvey Richard J. 
Published: January 2015

Background Intranasal corticosteroids (INCSs) are well established in the treatment of allergic rhinitis, chronic rhinosinusitis, and nasal polyposis. Although reversible atrophy of keratinized skin is seen with corticosteroids, the respiratory mucosa is histologically very different and but concerns remain among patients and some health-care professionals over local side effects on nasal respiratory mucosa. A systematic review and meta-analysis were performed of the available evidence for nasal mucosal atrophy as an adverse effect of INCSs in patients with sinonasal disease. Methods A systematic search of Embase (1974-) and Medline (1946-) databases to September 27, 2013 was performed. Inclusion criteria selected any study where the histopathology of nasal mucosa was assessed in patients with sinonasal disease using intranasally administered corticosteroids with or without a control group. Results Twenty-three hundred sixty-four publications were retrieved with a subsequent full text review of 149 publications for 34 articles that met the selection criteria. These articles included 11 randomized controlled trials, 5 cohorts, and 20 case series. Duration of treatment varied from 5 days to 5.5 years. “Mucosal atrophy” as an outcome was reported in 17 studies. The definition of “mucosal atrophy” was highly variable with a definition given in only 10 studies. One hundred thirty-six patients were represented in controlled studies of atrophy with only one study reporting the event in both groups with an odds ratio of “mucosal atrophy” at 0.51 (95% CI, 0.09-3.11; p = 0.47). Conclusion The concept of nasal mucosal atrophy is poorly defined and there is no histological evidence for deleterious effects from INCS use on human nasal mucosa.
Acupuncture for the Treatment of Allergic Rhinitis: A Systematic Review and Meta-Analysis
Authors: Feng Shaoyan , Han Miaomiao , Fan Yunping , Yang Guangwei , Liao Zhenpeng , Liao Wei , Li Huabin 
Published: January 2015

Background Because acupuncture may modulate the immune system, it has been proposed as a useful treatment for patients with allergic rhinitis (AR). Here, we assessed the evidence for the clinical efficacy of acupuncture for the management of AR patients by performing a systematic review and meta-analysis of the published literatures. Methods By searching PubMed, EMBASE, the Cochrane clinical trials database, and the China National Knowledge Infrastructure from 1980 through July 11, 2013, we collected and analyzed the randomized controlled trials (RCTs) of acupuncture for the treatment of AR patients to assess its efficacy and safety. Results Thirteen full papers that met our inclusion criteria were included, and a total of 2365 participants, including 1126 as treatment group and 1239 as control group, were enrolled. Compared with control group, acupuncture treatment group exerted a significant reduction in nasal symptom scores (weighted mean difference [WMD]: -4.42, 95% confidence interval [CI]: -8.42 to -0.43, p = 0.03), medication scores (WMD: 1.39, 95% CI: -2.18 to -0.61, p = 0005), and serum IgE (WMD: -75.00, 95% CI: -91.17 to -58.83, p < 0.00001). Data relating to Rhinitis Quality of Life Questionnaire (RQLQ) and 36-Item Short-Form (SF-36) component score in included studies were analyzed, which ultimately point to the efficacy of acupuncture treatment in improving quality of life in AR patients. No fatal events were reported in any of the included studies, and no serious systemic reaction, which needed treatment in the hospital, was related to the acupuncture treatment. Conclusion Our meta-analysis suggests that that acupuncture could be a safe and valid treatment option for AR patients.
Serum Level of Interleukin-21 is Elevated in Chronic Rhinosinusitis
Authors: Chao Pin-Zhir , Hsieh Ming-Shium , Lee Fei-Peng , Chen Shao-Yi , Cheng Chao-Wen , Chang Hui-Wen , Lin Yun-Tien , Ting Lai-Lei , Lin Yung-Feng , Chen Chien-Ho 
Published: January 2015

Background Chronic rhinosinusitis (CRS) is an inflammatory disease of the sinuses and mucosa with unclear pathogenesis. Interleukin (IL)-21 is mainly expressed in activated cluster of differentiation (CD)4+ T cells and has potent regulatory effects on the immune system. Objective This study is to determine whether IL-21 in the blood is correlated with CRS. Methods The blood samples from CRS patients and normal controls were analyzed in correlation with clinical features. The eosinophil percentage was counted, and serum levels of total immunoglobulin E (IgE) and IL-21 were analyzed by enzyme-linked immunosorbent assay (ELISA). In addition, IL-21 and interferon (IFN)-γ secreted from stimulated peripheral blood mononuclear cells (PBMCs) were measured by ELISA, and their mRNA expression levels were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Disease severity was scored based on computed tomography (CT) scan, nasal endoscopy, and global osteitis scoring scale (GOSS). Results A total of 55 CRS and 37 healthy subjects were recruited. The average levels of serum total IgE were 20 kU/L in normal group, 290 kU/L in CRS with nasal polys (CRSwNP), and 187 kU/L in CRS without nasal polys (CRSsNP). IL-21 levels were 28 pg/mL in normal group, 54 pg/mL in CRSwNP, and 71 pg/mL in CRSsNP. Both IgE and IL-21 were significantly elevated in both CRS patient subgroups. However, no significant difference was found between these two patient subgroups. The serum IL-21 levels correlated well with the disease severity in the patients. In addition, the secreted IL-21 was enhanced significantly in the patient's PBMCs stimulated by phytohemagglutin (PHA). Conclusion IL-21 could be a target for diagnosis and treatment of CRS.
Initial Investigation of Small Colony Variants of Staphylococcus Aureus in Chronic Rhinosinusitis
Authors: Gitomer Sarah A. , Ramakrishnan Vijay R. , Malcolm Kenneth C. , Kofonow Jennifer M. , Ir Diana , Frank Daniel N. 
Published: January 2015

Background Small colony variants (SCVs) are a metabolically inactive form of bacteria that can be difficult to eradicate. To examine whether SCVs contribute to Staphylococcus aureus persistence in chronic rhinosinusitis (CRS), we compared the prevalence of S. aureus SCVs in CRS patients and healthy controls. Methods Endoscopically guided middle meatus samples were collected from 23 CRS patients and 12 controls. Samples were cultured and screened for the presence of phenotypically small colonies. Candidate SCV isolates were classified by 16S rRNA gene sequencing. To further characterize the capacity of S. aureus isolates to form SCVs when stressed, colonies underwent a gentamicin exposure assay. Results Among CRS patient samples, 15 were culture positive for S. aureus (65.2%), and of those, two grew putative SCVs on selective media (8.7%). However, neither was genetically confirmed to be S. aureus upon sequencing. In healthy controls, eight specimens were culture positive for S. aureus (66.7%), and of these, two grew putative S. aureus SCVs on selective media (16.7%); but again, neither was confirmed to be S. aureus by 16S analysis. None of the four patients colonized with SCVs had evidence of sinonasal disease at a mean follow-up of eight months. S. aureus isolates from CRS patients and controls were equally likely to form SCVs with gentamicin exposure. Conclusion S. aureus SCVs were not associated with CRS in the current study. Their role in refractory CRS remains theoretical, and further research is warranted to determine whether S. aureus SCVs may reside in the intracellular compartment.
A Novel Method for Comparison of Tissue Fibrosis after Inferior Turbinate Surgery: Ultrasound Elastography
Authors: Gode Sercan , Turhal Goksel , Kismali Erkan , Ozturk Kerem , Midilli Rasit 
Published: January 2015

Background Ultrasound (US) elastography has been widely used for thyroid, liver, and lymph nodes as a research tool in the current medical practice. It has been described in the inferior turbinates and validated as a reliable, reproducible, noninvasive, and objective method that can detect the fibrosis-related tissue strain. There is no previous study that investigated the amount of fibrosis induced by radiofrequency and bipolar electrocautery in the inferior turbinates in a noninvasive and objective manner. The aim of this study was to assess the amount of inferior turbinate soft tissue fibrosis that was induced by radiofrequency ablation (RFA) and submucosal bipolar diathermy (SBD) by US elastography. Methods Thirty-eight inferior turbinates of 19 patients were included. RFA was applied to 18 inferior turbinates (group 1) and SBD was applied to 20 inferior turbinates (group 2). US elastography and visual analog scale (VAS) assessments were performed on all patients preoperatively and 6 months postoperatively. Results Preoperative mean US elastography scores in groups 1 and 2 were 2.55 ± 0.78 m/s and 2.56 ± 0.49 m/s, respectively (p < 0.05). Postoperative mean US elastography scores in groups 1 and 2 were 2.91 ± 1.03 m/s and 3.41 ± 0.86 m/s, respectively (p < 0.05). Preoperative mean VAS scores in groups 1 and 2 were 2.78 ± 0.94 and 2.50 ± 1.15, respectively. Postoperative mean VAS scores in groups 1 and 2 were 6.61 ± 1.61 and 6.10 ± 1.4, respectively (p < 0.05). Correlation of US elastography and VAS scores was insignificant (p > 0.05). Conclusion Both RFA and SBD of the inferior turbinates were effective in inducing scar tissue and, eventually, fibrosis in the soft tissue of inferior turbinates. Cauterization has been found to cause significantly higher amounts of fibrosis than radiofrequency; however, it did not reflect the comparable clinical outcome. This is the first study that objectively and noninvasively evaluates the targeted tissue fibrosis of the inferior turbinate surgeries by the novel inferior turbinate US elastography.
Constraint-Induced Movement Therapy After Injection of Botulinum Toxin Type A for a Patient With Chronic Stroke: One-Year Follow-up Case Report
Authors: Amano Satoru , Takebayashi Takashi , Hanada Keisuke , Umeji Atsushi , Marumoto Kohei , Furukawa Keiko , Domen Kazuhisa 
Published: January 2015

Background and Purpose
Spasticity, an aspect of upper motor neuron syndrome, is a widespread problem in patients with stroke. To date, no study has reported the long-term (up to 1 year) outcomes of botulinum toxin (BTX) injection in combination with constraint-induced movement therapy in patients with chronic stroke. In this case report, the long-term (1 year) effects of the combination of BTX type A injection and constraint-induced movement therapy on spasticity and arm function in a patient with chronic stroke and arm paresis are described.

Case Description
The patient was a 66-year-old man who had had an infarction in the right posterior limb of the internal capsule 4 years before the intervention. At screening, the patient was not able to voluntarily extend his interphalangeal or metacarpophalangeal joints beyond the 10 degrees required for constraint-induced movement therapy. From 12 days after BTX type A injection, the patient received 5 hours of constraint-induced movement therapy for 10 weekdays.

Outcomes
All outcome measures (Modified Ashworth Scale, Fugl-Meyer Assessment, Action Research Arm Test, and amount of use scale of the Motor Activity Log) improved substantially over the 1-year period (before intervention to 1 year after intervention). Repeat BTX type A injections were not necessary because muscle tone and arm function did not worsen during the observation period.

Discussion
The improved arm function may have reflected improvements in volitional movements and coordination or speed of movements in the paretic arm as a result of a reduction in spasticity, a reduction of learned nonuse behaviors, or use-dependent plasticity after the combination of BTX type A injection and constraint-induced movement therapy. In addition, the possibility of an influence of the passage of time or the Hawthorne effect cannot be ruled out. If this approach proves useful in future controlled studies, it may reduce the rising medical costs of the treatment of stroke.
Assessment of Fatigue in Rheumatoid Arthritis: A Psychometric Comparison of Single-item, Multiitem, and Multidimensional Measures
Authors: Oude Voshaar Martijn A.H. , ten Klooster Peter M. , Bode Christina , Vonkeman Harald E. , Glas Cees A.W. , Jansen Tim , van Albada-Kuipers Iet , van Riel Piet L.C.M. , van de Laar Mart A.F.J. 
Published: January 2015

Objective.To compare the psychometric functioning of multidimensional disease-specific, multiitem generic, and single-item measures of fatigue in patients with rheumatoid arthritis (RA).Methods.Confirmatory factor analysis (CFA) and longitudinal item response theory (IRT) modeling were used to evaluate the measurement structure and local reliability of the Bristol RA Fatigue Multi-Dimensional Questionnaire (BRAF-MDQ), the Medical Outcomes Study Short Form-36 (SF-36) vitality scale, and the BRAF Numerical Rating Scales (BRAF-NRS) in a sample of 588 patients with RA.Results.A 1-factor CFA model yielded a similar fit to a 5-factor model with subscale-specific dimensions, and the items from the different instruments adequately fit the IRT model, suggesting essential unidimensionality in measurement. The SF-36 vitality scale outperformed the BRAF-MDQ at lower levels of fatigue, but was less precise at moderate to higher levels of fatigue. At these levels of fatigue, the living, cognition, and emotion subscales of the BRAF-MDQ provide additional precision. The BRAF-NRS showed a limited measurement range with its highest precision centered on average levels of fatigue.Conclusion.The different instruments appear to access a common underlying domain of fatigue severity, but differ considerably in their measurement precision along the continuum. The SF-36 vitality scale can be used to measure fatigue severity in samples with relatively mild fatigue. For samples expected to have higher levels of fatigue, the multidimensional BRAF-MDQ appears to be a better choice. The BRAF-NRS are not recommended if precise assessment is required, for instance in longitudinal settings.