bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and rheological investigation of novel alginate/N‐succinylchitosan hydrogels
Authors: Nobile M. R. , Pirozzi V. , Somma E. , Gomez D'Ayala G. , Laurienzo P. 
Published: May 2008

AbstractIn the present article alginate hydrogels and novel hydrogels based on blends of alginate/N‐succinylchitosan have been realized in water solution at neutral conditions. The gels have been obtained by crosslinking via the internal setting method using calcium carbonate (CaCO3) as calcium ions source. A rheological investigation of both the plain alginate and the alginate/N‐succinylchitosan blend hydrogels has been performed by means of oscillatory dynamic measurements. The effect of the inclusion of different amounts of CaCO3 on the critical deformation (γc) characterizing the limit of the linear viscoelastic regime has been studied for the plain alginate gels. The frequency response in small amplitude oscillatory experiments of the plain alginate gels has been investigated in terms of the storage (G′) and loss (G″) modulus behavior. The dynamic data have been interpreted in terms of the Friedrich and Heymann model. The inclusion of the N‐succinylchitosan, in the range 10–50% w/w, had no effect on the γc values. On the contrary, when the 10% w/w of the N‐succinylchitosan is added to the plain alginate gels, a significant increase in the storage modulus values is recorded for all the systems analyzed. The gelation kinetics has been investigated and the results indicate that the kinetics process can be accelerated increasing the percentage of Ca+2 ions and/or including the N‐succinylchitosan in the plain alginate systems. Finally, the morphological analysis of scaffolds obtained from the hydrogels through freeze‐drying revealed an interconnected porous structure. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1167–1182, 2008
Study of the crystallization behaviors of isotactic polypropylene with sodium benzoate as a specific versatile nucleating agent
Authors: Dong Mu , Guo Zhaoxia , Su Zhiqiang , Yu Jian 
Published: May 2008

AbstractSodium benzoate (SB), a conventional nucleating agent of α‐phase isotactic polypropylene (iPP) was discovered to induce the creation of β‐phase iPP under certain crystalline conditions. Polarized optical microscopy (POM) and wide angle X‐ray diffraction (WAXD) were carried out to verify the versatile nucleating activity of SB and investigate the influences of SB's content, isothermal crystallization temperature, and crystallization time on the formation of β‐phase iPP. The current experimental results indicated that, under isothermal crystallization conditions, SB showed peculiar nucleating characteristics on inducing iPP crystallization which were different from those of the commercial β form nucleating agent (TMB‐5). The content of β crystal form of iPP nucleated with SB (PP/SB) increased initially with the increase of crystallization temperature, nucleating agent (SB) percentage or crystallization time, reached a maximum value, and then decreased as the crystallization temperature, nucleating agent percentage or crystallization time further increased. While the content of β crystal form of iPP nucleated with TMB‐5 (PP/TMB‐5) showed a completely different changing pattern with the crystallization conditions. The obvious difference of the two kinds of nucleating agents on inducing iPP crystallization can be explained by the versatile nucleating ability of SB. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1183–1192, 2008
Large tensile deformation behavior of oriented high‐density polyethylene: A correlation between cavitation and lamellar fragmentation
Authors: Lv Ruihua , Xu Wenfei , Na Bing , Zhang Qin , Fu Qiang 
Published: May 2008

AbstractOriented high‐density polyethylene (HDPE), prepared by melt extrusion drawing, has been employed to address the correlation between cavitation and lamellar fragmentation at large strain. This has been done by investigating the volume strain, elastic recovery properties, and microscopic morphology. The results indicate that the reversible volume strain becomes saturation at a true strain of about 0.3, which is essentially consistent with the critical one related to lamellar fragmentation (point C). Morphological observations on the deformed samples provide structural insights into above deformation behaviors. Enlarged voids are hard to recover due to dominant plastic deformation of crystals once lamellar fragmentation sets in and thus a transition of reversible volume strain with strain is presented. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1202–1206, 2008
Analysis of urinary proteomic patterns for diabetic nephropathy by ProteinChip
Authors: Gu Wei , Zou Li‐Xia , Shan Peng‐Fei , Chen Yi‐Ding 
Published: May 2008

AbstractDiabetic nephropathy (DN) is the main cause of mortality for diabetic patients. The objective of this work was to develop a proteomic approach to detect proteins or peptides in urine for identifying individuals in the early stage of DN. We obtained urine samples from 106 diabetic patients and 50 healthy subjects. Early stage of DN was defined as urine albumin‐to‐creatinine ratio between 30 to 299 mg/g. Mass spectra were generated using surface‐enhanced laser desorption/ionization time‐of‐flight mass spectrometry. Peaks were detected by Ciphergen SELDI software version 3.1. Over 1000 proteins or peptides were obtained using ProteinChip. About 200 of them, the m/z values were in the range from 1008.5 to 79 942.3 Da. These values were significantly differentiated between diabetic patients and contro1 subjects. A mathematical analysis revealed that a cluster of 8 up‐regulated proteins and 16 down‐regulated proteins was in the diabetic patients, with m/z values from 2197.3 to 79 613 Da. Four top‐ranked proteins, with m/z values of 4139.0, 4453.5, 5281.1, and 5898.5 Da, were selected as the potential fingerprints for detection of early stage DN with a sensitivity of 75% and a specificity of 80%. ProteinChip technology may be a novel non‐invasive method for detecting early stage DN.
Proteomics as a research tool in clinical and experimental ophthalmology
Authors: Cryan Lorna M. , O'Brien Colm 
Published: May 2008

AbstractIt is estimated that 37 million people worldwide suffer from blindness and 124 million people have impaired vision. While the relatively recently developed therapies, antivascular endothelial growth factor inhibitors for the treatment of age‐related macular degeneration, and prostaglandin analogues for the treatment of glaucoma are beneficial for some patients, there are many individuals with sight‐threatening diseases for whom no effective pharmacological therapy is available. For many of these diseases, the molecular mechanisms remain to be comprehensively elucidated, thus precluding the design of successful therapies against specific pathological targets. The current review summarises recent attempts to elucidate molecular mechanisms of ocular diseases, including diabetic retinal disease, age‐related macular degeneration and inherited blindness using proteomic methodologies. A novel hypothesis can be generated from global protein expression analysis of disease tissue, which can then be addressed with cellular and in vivo functional studies. For example, the identification of extracellular carbonic anhydrase from the vitreous of diabetic retinopathy patients using MS based proteomics led to the elucidation of a new pathway involved in intraretinal edema, which could be inhibited by a number of agents targeting different proteins in this pathway in relevant animal models. The potential of protein biomarkers for diagnosis and the identification of novel disease mechanisms are also discussed.
Identification of apolipoprotein C‐III as a potential plasmatic biomarker associated with the resolution of hepatitis C virus infection
Authors: Molina Sonia , Missé Dorothée , Roche Stéphane , Badiou Stéphanie , Cristol Jean‐Paul , Bonfils Claude , Dierick Jean‐François , Veas Francisco , Levayer Thierry , Bonnefont‐Rousselot Dominique , Maurel Patrick , Coste Joliette , Fournier‐Wirth Chantal 
Published: May 2008

AbstractUnderstanding the virus‐host interactions that lead to approximately 20% of patients with acute Hepatitis C Virus (HCV) infection to viral clearance is probably a key towards the development of more effective treatment and prevention strategies. Acute hepatitis C infection is usually asymptomatic and therefore rarely diagnosed. Nevertheless, HCV nucleic acid testing carried out on all blood donations detects donors who have resolved their HCV infection after seroconversion. Here we have used SELDI‐TOF‐MS technology to compare, at a proteomic level, plasma samples respectively from donors with HCV clearance, from donors with chronic HCV infection and from unexposed healthy donors (n = 15 per group). A candidate marker of about 9.4 kDa was detected as differentially expressed in the three groups. After purification we identified by nanoLC‐Q‐TOF‐MS/MS this candidate marker as Apolipoprotein C‐III (ApoC‐III). The identification was confirmed by western blot analysis. Levels of ApoC‐III were then determined in the 45 plasma samples by immunoturbidimetric assay. ApoC‐III was found to be higher in donors who had resolved their HCV infection than in donors with chronic infection, results which were consistent with SELDI‐TOF‐MS data. ApoC‐III is the first reported candidate biomarker in plasma associated with the spontaneous resolution of HCV infection.
Brane tilings and their applications
Authors: Yamazaki M. 
Published: May 2008

AbstractWe review recent developments in the theory of brane tilings and four‐dimensional 𝒩 = 1 supersymmetric quiver gauge theories. This review consists of two parts. In part I, we describe foundations of brane tilings, emphasizing the physical interpretation of brane tilings as fivebrane systems. In part II, we discuss application of brane tilings to AdS/CFT correspondence and homological mirror symmetry. More topics, such as orientifold of brane tilings, phenomenological model building, similarities with BPS solitons in supersymmetric gauge theories, are also briefly discussed. This paper is a revised version of the author's master's thesis submitted to Department of Physics, Faculty of Science, the University of Tokyo on January 2008, and is based on his several papers and some works in progress [1–7].
A Novel Approach for the Identification of Selective Anticonvulsants Based on Differential Molecular Properties for TBPS Displacement and Anticonvulsant Activity: An Integrated QSAR Modelling
Authors: Bhutoria Savita , Ghoshal Nanda 
Published: May 2008

AbstractIn order to gain insight into the structural and molecular requirements influencing the anticonvulsant activity against Pentylenetetrazole (PTZ)‐induced seizures and [35S]tert‐Butyl‐bicyclophosphorothionate (TBPS) displacement property (a measure of binding to GABAAreceptor), Quantitative Structure–Activity Relationship (QSAR) studies have been performed on a series of congeneric anticonvulsant agents proposed to act by binding to the lactone site of the GABAAreceptor. The aim of this work was to identify and analyse the various functionalities, which determine the TBPS displacement property and anticonvulsant activity by correlating with various molecular descriptors. Statistical techniques like Principal Component Analysis (PCA), Partial Least Squares (PLS), Multiple Linear Regression (MLR) and Genetic Function Approximation (GFA) were applied to identify the structural and physicochemical requirements for TBPS displacement property and anticonvulsant activity. The generated equations were statistically validated using leave‐one‐out cross‐validation technique and randomization. The best models were also validated by prediction of activity of compounds, not used for the development of QSAR models. The results from reasonably good QSAR models (statistically validated) clearly indicated that TBPS displacement property and the anticonvulsant activity are defined by different molecular parameters. Based on this finding, a novel approach is proposed, using integrated QSAR modelling, for the identification of potential and selective anticonvulsant agents.
Mathematical Correlations for Gas‐to‐Olive Oil, Gas‐to‐Saline Solution, and Saline Solution‐to‐Olive Oil Partition Coefficients Based on the Goss Modified Abraham Model
Authors: Sprunger Laura M. , Acree William E. , Abraham Michael H. 
Published: May 2008

AbstractMathematical expressions have been developed for correlating experimental gas‐to‐olive oil, gas‐to‐saline solution, and saline solution‐to‐olive oil partition coefficients at 310 K with the Goss modified version of the Abraham model. The derived correlations were found to back‐calculate the three sets of partition coefficients to better than 0.18 log units. Training set and test set analyses were used to validate each derived correlation.
A geometric approach for the design of MIMO sliding controllers. Application to a wind‐driven doubly fed induction generator
Authors: Valenciaga F. , Puleston P. F. , Spurgeon S. K. 
Published: May 2008

AbstractThis paper presents a systematic methodology to design controllers for a general class of nonlinear MIMO systems affine in the control in the presence of bounded uncertainties and disturbances. The design method is developed using a theoretical framework based on the combination of a geometric approach and sliding mode techniques. The resulting robust control law guarantees finite time convergence, whereas chattering reduction is achieved by utilizing the minimum discontinuous action required to ensure disturbance rejection. The proposed methodology is applied to the control of a grid‐connected wind energy generation system based on a doubly fed induction generator. The control objectives considered in this paper are maximization of the wind energy conversion and reactive power regulation to minimize machine losses. Copyright © 2008 John Wiley & Sons, Ltd.
The persistent‐access‐caching algorithm
Authors: Jelenković Predrag R. , Radovanović Ana 
Published: May 2008

AbstractCaching is widely recognized as an effective mechanism for improving the performance of the World Wide Web. One of the key components in engineering the Web caching systems is designing document placement/replacement algorithms for updating the collection of cached documents. The main design objectives of such a policy are the high cache hit ratio, ease of implementation, low complexity and adaptability to the fluctuations in access patterns. These objectives are essentially satisfied by the widely used heuristic called the least‐recently‐used (LRU) cache replacement rule. However, in the context of the independent reference model, the LRU policy can significantly underperform the optimal least‐frequently‐used (LFU) algorithm that, on the other hand, has higher implementation complexity and lower adaptability to changes in access frequencies. To alleviate this problem, we introduce a new LRU‐based rule, termed the persistent‐access‐caching (PAC), which essentially preserves all of the desirable attributes of the LRU scheme. For this new heuristic, under the independent reference model and generalized Zipf's law request probabilities, we prove that, for large cache sizes, its performance is arbitrarily close to the optimal LFU algorithm. Furthermore, this near‐optimality of the PAC algorithm is achieved at the expense of a negligible additional complexity for large cache sizes when compared to the ordinary LRU policy, since the PAC algorithm makes the replacement decisions based on the references collected during the preceding interval of fixed length. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008
Girls and science: A review of four themes in the science education literature
Authors: Brotman Jennie S. , Moore Felicia M. 
Published: May 2008

AbstractDespite valuable syntheses of the field of gender and science education, there has not been a systematic, comprehensive review of the literature on gender and science education in recent years. We examine the literature pertaining to girls' engagement in science and develop four themes (equity and access, curriculum and pedagogy, the nature and culture of science, and identity) that we believe provide a coherent picture of the different kinds of approaches happening currently, while at the same time allowing for discussion of how ideas in the field have progressed and changed over time. We present new questions and approaches for further research that arise when applying insights from these themes to ongoing work in gender and science education. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 971–1002, 2008
Measuring knowledge of natural selection: A comparison of the CINS, an open‐response instrument, and an oral interview
Authors: Nehm Ross H. , Schonfeld Irvin Sam 
Published: May 2008

AbstractGrowing recognition of the central importance of fostering an in‐depth understanding of natural selection has, surprisingly, failed to stimulate work on the development and rigorous evaluation of instruments that measure knowledge of it. We used three different methodological tools, the Conceptual Inventory of Natural Selection (CINS), a modified version of Bishop and Anderson's (Bishop and Anderson [1990] Journal of Research in Science Teaching 27: 415–427) open‐response test that we call the Open Response Instrument (ORI), and an oral interview derived from both instruments, to measure biology majors' understanding of and alternative conceptions about natural selection. We explored how these instruments differentially inform science educators about the knowledge and alternative conceptions their students harbor. Overall, both the CINS and ORI provided excellent replacements for the time‐consuming process of oral interviews and produced comparable measures of key concept diversity and, to a lesser extent, key concept frequency. In contrast, the ORI and CINS produced significantly different measures of both alternative conception diversity and frequency, with the ORI results completely concordant with oral interview results. Our study indicated that revisions of both the CINS and ORI are necessary because of numerous instrument items characterized by low discriminability, high and/or overlapping difficulty, and mismatches with the sample. While our results revealed that both instruments are valid and generally reliable measures of knowledge and alternative conceptions about natural selection, a test combining particular components of both instruments—a modified version of the CINS to test for key concepts, and a modified version of the ORI to assess student alternative conceptions—should be used until a more approprite instrument is developed and rigorously evaluated. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 1131–1160, 2008
Seeking effectiveness and equity in a large college chemistry course: an HLM investigation of Peer‐Led Guided Inquiry
Authors: Lewis Scott E. , Lewis Jennifer E. 
Published: May 2008

AbstractThis study employed hierarchical linear models (HLM) to investigate Peer‐Led Guided Inquiry (PLGI), a teaching practice combining cooperative learning and inquiry and tailored for a large class. Ultimately, the study provided an example of the effective introduction of a reform pedagogical approach in a large class setting. In the narrative, the strengths of HLM as a statistical technique are discussed in the context of pedagogical reforms, and the case is made for the use of HLM in rigorous determinations of both effectiveness and equity associated with reform practices. The implementation of PLGI in a college‐level general chemistry course is also described. For the study, two general HLM models suited to investigating reform were developed and utilized to examine the effectiveness and equity of PLGI as implemented in this setting. The models showed that the reform was associated with statistically significant improvement over traditional pedagogy in terms of academic performance on multiple measures, but achieving equity remained elusive: the consequences of pre‐existing achievement gaps did not lessen as a result of reform implementation. The analysis led to several implications for educational research, particularly in terms of evaluating pedagogical reforms, as well as for teaching. Choosing effective and equitable pedagogies for classroom implementation remains a critical goal for classes of any size. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 794–811, 2008
Determination of the angle of attack on rotor blades
Authors: Shen Wen Zhong , Hansen Martin O. L. , Sørensen Jens Nørkær 
Published: May 2008

AbstractTwo simple methods for determining the angle of attack (AOA) on a section of a rotor blade are proposed. Both techniques consist of employing the Biot–Savart integral to determine the influence of the bound vorticity on the velocity field. In the first technique, the force distribution along the blade and the velocity at a monitor point in the vicinity of the blade are assumed to be known from experiments or CFD computations. The AOA is determined by subtracting the velocity induced by the bound circulation, determined from the loading, from the velocity at the monitor point. In the second method, the full pressure distribution on the blade is assumed to be known and used to determine the local distribution of circulation along the surface contour of the blade. Using the local distribution of circulation to determine the influence of the bound vorticity enables the velocity monitor points to be located closer to the blade, and thus to determine the AOA with higher accuracy. Data from CFD computations for flows past the Tellus 95 kW wind turbine at different wind speeds are used to test both techniques. Comparisons show that the proposed methods are in good agreement with existing techniques. The advantage of the proposed techniques, as compared with existing techniques, is that they can be used to determine the AOA on rotor blades under general flow conditions (e.g. operations in yaw or with dynamic inflow). Copyright © 2008 John Wiley & Sons, Ltd.
Clinical Features of Hepatocellular Carcinoma Developing Extrahepatic Recurrences After Curative Resection
Authors: Tanaka Kuniya , Shimada Hiroshi , Matsuo Kenichi , Takeda Kazuhisa , Nagano Yasuhiko , Togo Shinji 
Published: May 2008

AbstractBackgroundFew details of the clinical features of hepatocellular carcinoma (HCC) developing extrahepatic recurrence after a curative resection have been published. The purpose of this study was to clarify the clinicopathologic findings of patients with HCC who experienced extrahepatic metastases.MethodsClinicopathologic data were available for 119 patients who underwent an R0 resection for HCC. Twenty‐three patients who developed extrahepatic metastases during the follow‐up period were compared with the patients who remained free from recurrence for at least 5 years after resection (n = 21) or with only intrahepatic recurrences (n = 75).ResultsPatients with extrahepatic recurrences were more likely to have their tumor macro‐ or microscopically invading the tumor capsule (P < 0.001) and hepatic vein (P = 0.003), a high AFP concentration (P = 0.014), and advanced TNM stage (P = 0.006) than the other patients. As for treatment‐related variables, inflow vessel occlusion during hepatectomy was less frequently associated with extrahepatic recurrences than if it were not performed (P < 0.001). By multivariate analysis, absence of tumor invasion to the capsule (relative risk [RR] = 0.080; P = 0.023) or to the hepatic vein (RR = 0.108; P = 0.014) and a hepatectomy in which inflow vessel occlusions were performed (RR = 0.161; P = 0.004) were selected as independent factors for reducing extrahepatic recurrences after a hepatectomy.ConclusionIn HCC patients, the control of intrahepatic recurrences and extrahepatic recurrences after a hepatectomy is important to improve the prognosis. Inflow occlusion during the hepatectomy may reduce HCC metastases to extrahepatic sites.