bluuebunny/crossref_metadata_2025 huggingface dataset:
High dose adenosine for suboptimal myocardial reperfusion after primary PCI: A randomized placebo‐controlled pilot study
Authors: Stoel Martin G. , Marques Koen M.J. , de Cock Carel C. , Bronzwaer Jean G.F. , Birgelen Clemens von , Zijlstra Felix
Published: November 2007

Objectives: This study was designed to investigate the influence of high dose intracoronary adenosine on persistent ST‐segment elevation after primary percutaneous coronary intervention (PCI). Background: After successful PCI for acute myocardial infarction 40–50% of patients show persistent ST‐segment elevation indicating suboptimal myocardial reperfusion. Adenosine has been studied to ameliorate reperfusion and is frequently used in a variety of doses, but there are no prospective studies to support its use for treatment of suboptimal reperfusion. Methods: We conducted a blinded, randomized, and placebo‐controlled study with high dose intracoronary adenosine in 51 patients with <70% ST‐segment resolution (STRes) after successful primary PCI. All patients were treated with stents and abciximab. Results: Immediately after adenosine, significantly more patients showed optimal (>70%) STRes compared with placebo (33% versus 9%, P < 0.05). Mean STRes was higher after adenosine (35.4% versus 23.0%, P < 0.05). In addition, TIMI frame count was significant lower (15.7 versus 30.2, P < 0.005), Myocardial Blush Grade was higher (2.7 versus 2.0, P < 0.05) and resistance index was lower in the adenosine group (0.70 versus 1.31 mm Hg per ml/min, P < 0.005). Conclusions: Intracoronary adenosine accelerates recovery of microvascular perfusion in case of persistent ST segment elevation after primary PCI. © 2007 Wiley‐Liss, Inc.
Transcatheter closure of atrial septal defect with Amplatzer® device in children aged less than 10 years old: Immediate and late follow‐up
Authors: Rossi Raul I. , Cardoso Cristiano de Oliveira , Machado Paulo Renato , Francois Lisia Galant , Horowitz Estela Suzana K. , Sarmento‐Leite Rogerio
Published: November 2007

Aims: To analyze the efficacy and follow‐up results of percutaneous closure of Atrial septal defect (ASD) with the Amplatzer® septal occluder in children aged <10 years old. Methods: Between November 1998 and September 2005, 27 patients diagnosed with ASD were treated percutaneously with an Amplatzer septal occluder. The procedure was carried out in the cathlab, under general anesthesia and with both fluoroscopy and transesophageal echocardiography guidance. Basal physical examinations and echocardiograms were performed prior to the procedure and at 30 days, 6, and 12 months of follow‐up. Survival free of symptom was estimated by Kaplan–Meier. Results: The mean age, weight, height, body mass index, and corporal surface was: 5.35 ± 2.11 years, 23.07 ± 9.43 kg, 110.55 ± 17.6 cm, 16.77 ± 2.42 kg/m2, and 1.24 ± 2.44 m2. The prevalence of septal aneurysm was 3.7% and all patients presented single secundum ASD. The mean stretched diameter by fluoroscopy and transesophageal echocardiography were 17.18 ± 6.75 mm and 16.77 ± 5.99 mm, and the prostheses sizes were 18.83 ± 6.98 mm, ranging from 10 to 30 mm. The systolic and diastolic pulmonary pressures were 25.26 ± 5.97 mm Hg and 13.38 ± 3.40 mm Hg, respectively. The procedure time was 82.92 ± 29.14 min and the hospital stay was 2.20 ± 0.26 days. Clinical and echocardiography follow‐ups were performed within 11.59 ± 4.42 months and all devices were in the correct position with no residual shunt. Right ventricular diameter decreased from 19.38 ± 5.23mm to 11.38 ± 11.92 (P 0.001). No major complications or deaths occurred; two patients had a hematoma at the vascular access. Conclusion: Secundum atrial septal defect closure can be safely and successfully performed with the Amplatzer septal occluder in children younger than 10 years old. © 2008 Wiley‐Liss, Inc.
Synthesis of Nanometer‐Scale Porphyrin Wheels of Variable Size
Authors: Hori Takaaki , Peng Xiaobin , Aratani Naoki , Takagi Akihiko , Matsumoto Takuya , Kawai Tomoji , Yoon Zin Seok , Yoon Min‐Chul , Yang Jaesung , Kim Dongho , Osuka Atsuhiro
Published: November 2007

Starting from 1,3‐phenylene linked diporphyrin zinc(II) complex 2ZA, repeated stepwise AgI‐promoted coupling reactions provided linear oligomers from 2nZA up to 128ZA. Of these zigzag shaped porphyrin arrays, the AgI‐promoted intramolecular cyclization reaction of 2 nZA (n=5, 6, 8, 9, 12, and 16) under dilute conditions gave the corresponding cyclic porphyrin wheels C2nZA (n=5, 6, 8, 9, 12, and 16), whereas large arrays 2nZA (n=24, 32, and 48) did not provide cyclic porphyrin products. These large discrete porphyrin arrays and wheels were fully characterized by means of 1H NMR spectroscopy, MALDI‐TOF mass spectrometry, UV/Vis absorption spectroscopy, GPC‐HPLC analysis, and the scanning tunneling microscopy (STM) technique. The STM images of C12ZA and C18ZA reveal their large circular structures. In the cyclic structures of C2nZA in solution, however, the gradual decrease in fluorescence quantum yields and fluorescence lifetimes are observed, reflecting some conformational heterogeneities. Collectively, the present work provides an important contribution to the construction of fully covalently linked large cyclic arranged porphyrin arrays with ample electronic interactions as a model of light‐harvesting antenna.
Death receptor expression is associated with poor response to chemotherapy and shorter survival in metastatic ovarian carcinoma
Authors: Dong Hiep Phuc , Kleinberg Lilach , Silins Ilvars , Flørenes Vivi Ann , Tropé Claes G. , Risberg Björn , Nesland Jahn M. , Davidson Ben
Published: November 2007

BACKGROUND.

Death receptors mediate both apoptosis and survival in cancer cells. The authors analyzed death receptor expression in metastatic ovarian carcinoma.

METHODS.

Viable tumor cells in ovarian carcinoma effusions (n = 95) were analyzed for DR4, DR5, Fas, TNFR1, and TNFR2 expression using flow cytometry. Results were analyzed for association with clinicopathologic parameters, chemotherapy response, and survival.

RESULTS.

DR4, DR5, and Fas were expressed by the majority of specimens, with less frequent expression of TNFR1 and TNFR2. DR4 (P = .005) and TNFR2 (P = .041) expression was higher in FIGO stage IV compared with stage III tumors. Effusions from patients who responded poorly to chemotherapy administered at disease recurrence had significantly higher DR4 (P = .006), DR5 (P = .01), and Fas (P = .001) expression. In univariate survival analysis, higher DR4 expression in viable cells correlated with poor overall (P = .0352) and progression‐free (P = .0411) survival. DR4 expression was found to be an independent predictor of overall (P = .008) and progression‐free (P = .003) survival.

CONCLUSIONS.

The authors have presented the first evidence of death receptor coexpression in ovarian carcinoma effusions. The association of death receptor expression in effusions with advanced stage, poor response to chemotherapy, and shorter survival suggests that these molecules are linked to an aggressive clinical course in metastatic ovarian carcinoma. Cancer 2008. © 2007 American Cancer Society.
QoS modeling and analysis of component‐based software systems: a stochastic approach
Authors: Xia Yunni , Wang Hanpin , Feng Wangsen , Huang Yu
Published: November 2007

There is a growing demand for using commercial‐off‐the‐shelf (COTS) software components to facilitate the development of software systems. Among many research topics for component‐based software, quality‐of‐service (QoS) evaluation is yet to be given the importance it deserves. In this paper, we propose a novel analytical model to evaluate the QoS of component‐based software systems. We use the component execution graph (CEG) graph model to model the architecture at the process level and the interdependence among components. The CEG graph can explicitly capture sequential, parallel, selective and iterative compositions of components. For QoS estimation, each component in the CEG model is associated with execution rate, failure rate and cost per unit time. Three metrics of the QoS are considered and analytically calculated, namely make‐span, reliability and cost. Through a case study, we show that our model is capable of modeling real‐world COTS software systems effectively. Also, Monte‐Carlo simulation in the case study indicates that analytical results are consistent with simulation and all are covered by 95% confidence intervals. We also present a sensitivity analysis technique to identify QoS bottlenecks. This paper concludes with a comparison with related work. Copyright © 2007 John Wiley & Sons, Ltd.
Anterior cingulate dysfunction in geriatric depression
Authors: Alexopoulos George S. , Gunning‐Dixon Faith M. , Latoussakis Vassilios , Kanellopoulos Dora , Murphy Christopher F.
Published: November 2007

Background

Although several brain abnormalities have been identified in geriatric depression, their relationship to the pathophysiological mechanisms leading to the development and perpetuation of this syndrome remain unclear.

Methods

This paper reviews findings on the anterior cingulate cortex (ACC) function and on the relationship of ACC abnormalities to the clinical presentation and the course of geriatric depression in order to elucidate the pathophysiological role of ACC in this disorder.

Results

The ACC is responsible for conflict detection and emotional evaluation of error and is connected to brain structures that regulate mood, emotional valence of thought and autonomic and visceral responses, which are functions disturbed in depression. Geriatric depression often is accompanied by abnormalities in some executive functions and has a clinical presentation consistent with ACC abnormalities. Indices of ACC dysfunction are associated with adverse outcomes of geriatric depression.

Conclusions

Converging findings suggest that at least some ACC functions are abnormal in depression and these abnormalities are pathophysiologically meaningful. Indices of ACC dysfunction may be used to identify subgroups of depressed elderly patients with distinct illness course and treatment needs and serve as the theoretical background for novel treatment development. Copyright © 2007 John Wiley & Sons, Ltd.
A catchment framework for one‐dimensional models: introducing FLUSH and its application
Authors: Paydar Zahra , Gallant John
Published: November 2007

A new modelling framework capable of incorporating detailed one‐dimensional models in a catchment context is presented which can be used to asses the hydrological implications (recharge, discharge, salt movement) of different land uses on different parts of the catchment. The modelling framework incorporates farming systems models and, thus, simulates crop and pasture production, whilst also accounting for lateral fluxes of water (surface and subsurface) and groundwater recharge and discharge.

The framework was applied to Simmons Creek catchment, a subcatchment of the Billabong Creek in southern New South Wales, comprising gentle uplands and substantial low‐relief areas containing swamps. An integrated approach incorporating soil, hydrology, hydrogeology, and terrain analysis resulted in interpretation of landscape function and the necessary parameterization of the modelling framework. Current land use (crop rotation and pasture) and an alternative land use (10% trees on uphill units and pasture in the lower lying lands) were simulated to compare the relative contribution of parts of the catchment with total recharge. Comparison between current and alternative land use over 44 years of simulations indicated a decrease of mean annual drainage from 39 to 29 mm year−1 and an average reduction of the groundwater level of about 0·4 m. A more substantial decrease in water‐table depth would require targeted tree planting over larger areas. This can be investigated further with the spatial framework. Copyright © 2007 John Wiley & Sons, Ltd.
Sulindac and its metabolites induce carcinogen metabolizing enzymes in human colon cancer cells
Authors: Ciolino Henry P. , Bass Sara E. , MacDonald Christopher J. , Cheng Robert Y.S. , Yeh Grace Chao
Published: November 2007

Sulindac is a nonsteroidal antiinflammatory drug that has been demonstrated to be a potent chemopreventive agent against colorectal cancer in both human and animal models. In vivo, sulindac may be reversibly reduced to the active antiinflammatory compound, sulindac sulfide, or irreversibly oxidized to sulindac sulfone. Sulindac has also been shown to inhibit polycyclic aromatic hydrocarbon (PAH)‐induced cancer, but the molecular mechanisms of its antitumor effect remain unclear. In this study, we investigated the effects of sulindac and its metabolites on the expression of enzymes that metabolize and detoxify PAHs in 2 human colon cancer cell lines, LS180 and Caco‐2. Sulindac and sulindac sulfide induced a sustained, concentration‐dependent increase in CYP enzyme activity as well as an increase in the mRNA levels of CYP1A1, CYP1A2 and CYP1B1. Sulindac and sulindac sulfide induced the transcription of the CYP1A1 gene, as measured by the level of heterogeneous nuclear CYP1A1 RNA and verified by the use of actinomycin D as a transcription inhibitor. Chromatin immunoprecipitation assays demonstrated that sulindac and sulindac sulfide also increased the nuclear level of activated aryl hydrocarbon receptor, the transcription factor which mediates CYP expression. Additionally, sulindac and both metabolites increased the activity and mRNA expression of the carcinogen detoxification enzyme NAD(P)H:quinone oxidoreductase, as well as the expression of UDP‐glucuronosyltransferase mRNA. These results show an overall upregulation of carcinogen metabolizing enzymes in colon cancer cells treated with sulindac, sulindac sulfide and sulindac sulfone that may contribute to the established chemoprotective effects of these compounds. © 2007 Wiley‐Liss, Inc.
Confocal Raman microspectroscopy on excised human skin: uncertainties in depth profiling and mathematical correction applied to dermatological drug permeation
Authors: Tfayli A. , Piot O. , Manfait M.
Published: November 2007

Confocal Raman microspectroscopy represents the advantage of giving structural and conformational information on samples without any destructive treatment. Recently, several studies were achieved to study the skin hydration, endogenous and exogenous molecules repartition in the skin using the confocal feature of this technique. Meanwhile, when working through a material boundary with a different refractive index, the main limitation remains the spatial precision, especially the distortion in the depth and the depth resolution. Recently, several authors described mathematical models to correct the depth and the resolution values. In this study, we combined theoretical approaches, proposed by different authors with experimental measurements to try to find out the most appropriate approach for correction. We then applied the corrections on in‐depth profiles tracking the penetration of Metronidazole, a drug produced by Galderma for rosacea treatment, through excised human skin. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Promotion of peripheral nerve growth by collagen scaffolds loaded with collagen‐targeting human nerve growth factor‐β
Authors: Sun Wenjie , Lin Hang , Chen Bing , Zhao Wenxue , Zhao Yannan , Dai Jianwu
Published: November 2007

Nerve growth factor (NGF) plays a critical role in neuronal development and regeneration. However, the lack of efficient NGF delivery system limits its clinical application. We reported that a peptide deduced from collagenase, TKKTLRT, fused with NGF‐β could develop a collagen based NGF targeting delivery system. Our results showed that this peptide could allow fused NGF‐β bind to collagen specifically. In addition, we found that the polypeptide could result in a 2.3‐fold increase in the expression level and a significant improvement of bioactivity of fused NGF‐β. In the in vivo function study, collagen membranes loaded with the collagen binding NGF enhanced the nerve growth. Thus, the targeting wound repair system could be important for the repair of peripheral nerve injury. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Bioactivity and cytocompatibility of silicon wafers treated by water
Authors: Niu Yaran , Liu Xuanyong , Ding Chuanxian
Published: November 2007

A range of bioactive ceramics can induce bone‐like apatite to deposit on their surface in simulated body fluid (SBF). In this work, the silicon wafer was treated using deionized water to improve its bioactivity. The morphology and chemical composition of the treated silicon wafer was examined using Fourier transform infrared spectroscopy, atomic force microscopy and X‐ray photoelectron spectroscopy. Field emission scanning electron microscopy was used to observe the surface morphologies of silicon wafers soaked in SBF. The results indicated that a hydrated sub‐oxide film having SiOH groups formed on the surface of the silicon wafer after the water treatment. The amount of SiOH groups increased with raising the treatment temperature or prolonging the immersion time. Apatite was deposited on the surface of water‐treated silicon wafers immersed in SBF. The apatite deposition was correlated with the amount of SiOH groups. Human mesenchymal stem cells cultured on the surface of the water‐treated silicon wafers showed good adhesion and spread, indicating that the cytocompatibility of silicon wafer was enhanced by this water treatment. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Reactive oxygen species involved in prenylflavonoids, icariin and icaritin, initiating cardiac differentiation of mouse embryonic stem cells
Authors: Wo Yan‐bo , Zhu Dan‐yan , Hu Ying , Wang Zhi‐Qiang , Liu Jian , Lou Yi‐Jia
Published: November 2007

The significant promoting effects of some prenylflavonoids on cardiac differentiation of mouse embryonic stem (ES) cells via reactive oxygen species (ROS) signaling pathway were investigated. The most effective differentiation was facilitated by icariin (ICA), followed by icaritin (ICT), while desmethylicaritin (DICT) displayed the weakest but still significant inducible effect. Contrarily, DICT demonstrated the strongest anti‐oxidative activity while ICA displayed only little in vitro, which was well matched with the hydroxyl (OH) numbers and the positions in the molecular structures. Therefore, ROS signaling cascades were assumed to be involved in prenylflavonoids induced cardiomyogenesis. Treatment with ICA, intracellular ROS in embryoid bodies was rapidly elevated, which was abolished by the NADPH‐oxidase inhibitor apocynin; elimination of intracellular ROS by vitamin E or pyrrolidine dithiocarbamate (PDTC) inhibited ICA induced cardiomyogenesis; ROS‐sensitive extracellular‐regulated kinase 1, 2 (ERK1, 2) and p38 activation were further observed, the cardiomyogenesis was significantly inhibited in the presence of ERK1, 2 or p38 inhibitor U0126 or SB203580, indicating the roles of NADPH‐ROS‐MAPKs signaling cascades in prenylflavonoids induced cardiac differentiation. There was no difference in Nox4 NADPH oxidase expression between ICA and ICT treatments, however, ROS concentration in EBs after ICT administration was lower than that after ICA treatment, followed by less activation of ERK1, 2, and p38. These results revealed that the significant promoting effects of prenylflavonoids on cardiac differentiation was at least partly via ROS signaling cascades, and the facilitating abilities preferentially based on the nature of prenylflavonoids themselves, but anti‐oxidative activity determined by the OH numbers and the positions in the structures do influence the cardiomyogenesis in vitro. J. Cell. Biochem. 103: 1536–1550, 2008. © 2007 Wiley‐Liss, Inc.
Evidence of in vivo osteoinduction in adult rat bone by adeno‐Runx2 intra‐femoral delivery
Authors: Bhat Bheem M. , Robinson John A. , Coleburn Valerie E. , Zhao Weiguang , Kharode Yogendra
Published: November 2007

The bone marrow microenvironment provides a unique opportunity in vivo to assess the role of genes in bone remodeling. The objective of this study was to determine whether Runx2 expression is regulated by rhBMP‐2 in vivo and to examine the effect of Runx2 overexpression on bone in vivo. In the in vivo calvaria model we used, rhBMP‐2 induced Runx2 protein expression in periosteal cells while in vitro, adenovirus‐mediated Runx2 overexpression induced mineralization in mesenchymal stem cells. A single injection of adeno‐Runx2 directly into the bone marrow of the right femur in mature rats, and subsequent analysis after 3 weeks, showed a significant bone mineral density (BMD) increase (∼15%) as compared to the controls. The whole‐femur mean BMD of the active virus‐injected group was 0.193 (g/cm2) while that of the control virus‐injected group was 0.175 (g/cm2) (P < 0.05). In addition, a significant increase (36%) in trabecular BMD at the distal end of the femur was observed. These data demonstrate that directly delivering adeno‐Runx2 into bone marrow of adult rats induces osteogenesis and illustrates potential advantages of such approaches over ex vivo gene therapy protocols involving marrow cell isolation, gene transduction, and subsequent in vivo transfer. J. Cell. Biochem. 103: 1912–1924, 2007. © 2007 Wiley‐Liss, Inc.
The nonexistence of projective planes of order 12 with a collineation group of order 8
Authors: Akiyama Kenzi , Suetake Chihiro
Published: November 2007

In this article, we prove that there does not exist a symmetric transversal design ${\rm STD}_2[12;6]$ which admits an automorphism group of order 4 acting semiregularly on the point set and the block set. We use an orbit theorem for symmetric transversal designs to prove our result. As a corollary of the result, we prove that there is no projective plane of order 12 admitting a collineation group of order 8. © 2007 Wiley Periodicals, Inc. J Combin Designs 16: 411–430, 2008
Pebbling and optimal pebbling in graphs
Authors: Bunde David P. , Chambers Erin W. , Cranston Daniel , Milans Kevin , West Douglas B.
Published: November 2007

Given a distribution of pebbles on the vertices of a graph G, a pebbling move takes two pebbles from one vertex and puts one on a neighboring vertex. The pebbling number Π(G) is the least k such that for every distribution of k pebbles and every vertex r, a pebble can be moved to r. The optimal pebbling number ΠOPT(G) is the least k such that some distribution of k pebbles permits reaching each vertex.

Using new tools (such as the “Squishing” and “Smoothing” Lemmas), we give short proofs of prior results on these parameters for paths, cycles, trees, and hypercubes, a new linear‐time algorithm for computing Π(G) on trees, and new results on ΠOPT(G). If G is connected and has n vertices, then $\Pi_{\rm OPT}(G)\le \lceil{2n/3}\rceil$ (sharp for paths and cycles). Let an,k be the maximum of ΠOPT(G) when G is a connected n‐vertex graph with δ(G) ≥ k. Always $2 \lceil{n \over {k+1}}\rceil \le a_{{n},k}\le 4 \lceil{n \over {k+1}}\rceil$, with a better lower bound when k is a nontrivial multiple of 3. Better upper bounds hold for n‐vertex graphs with minimum degree k having large girth; a special case is $\Pi_{{\rm OPT}}({G})\le {16}{n}/{({k}^{2}+{17})}$ when G has girth at least 5 and k ≥ 4. Finally, we compute ΠOPT(G) in special families such as prisms and Möbius ladders. © 2007 Wiley Periodicals, Inc. J Graph Theory 57: 215–238, 2008
Nonlinear optical fiber based high resolution all‐optical waveform sampling
Authors: Andrekson P.A. , Westlund M.
Published: November 2007

When there is a need to accurately characterize optical waveforms and, it is not surprising that some of the best, albeit only recently established, techniques to do this rely on all‐optical phenomena. Some basic reasons why all‐optical sampling holds great promise as a very useful tool well into the foreseeable future are that there are no ringing phenomena with associated waveform distortion as in electronic sampling due to impedance mismatch, and that the time resolution can be made extremely high (⩽ 1 ps) while yet also offering high sensitivity for e.g. eye diagram (a superposition of all ‘1’ and ‘0’ in a data sequence that is widely used in telecommunications testing) and statistical analysis. In this paper, we review recent developments in optical fiber‐based sampling of optical waveforms. In particular, we describe the state‐of‐the‐art in terms of the various performance measures as well as their trade‐offs.
An Exploration of Needs for Connotative Messages during Image Search Process
Authors: Yoon JungWon
Published: November 2007

This study aims to provide an understanding of the information seeking process for image documents by focusing on needs for connotative messages. For this purpose, this study attempted to investigate and compare three stages of the image search process in terms of use of image attributes. The three stages of the image search process are identified as initiation, representation and selection, and image attribute levels are defined as color, denotative, and connotative attributes. Data was collected from a survey questionnaire composed of Likert scales, open questionnaires, and Semantic Differential scales. The study found that while color, denotative, and connotative attributes were all considered important by users, color itself did not have critical impact during the representing and selecting stages. Denotative and connotative attributes were important across the overall search process and users employed diverse denotative and connotative terms for finding a satisfactory image under a given task. This study also demonstrated that affective attributes of an image can be represented with reduced dimensions using Semantic Differential scales, and that reduced dimensions can be used to indicate more meaningful and relevant images.
What Can Searching Behavior Tell Us About the Difficulty of Information Tasks? A Study of Web Navigation
Authors: Gwizdka Jacek , Spence Ian
Published: November 2007

Task has been recognized as an influential factor in information seeking behavior. An increasing number of studies are concentrating on the specific characteristics of the task as independent variables to explain associated information‐seeking activities. This paper examines the relationships between operational measures of information search behavior, subjectively perceived post‐task difficulty and objective task complexity in the context of factual information‐seeking tasks on the web. A question‐driven, web‐based information‐finding study was conducted in a controlled experimental setting. The study participants performed nine search tasks of varying complexity. Subjective task difficulty was found to be correlated with many measures that characterize the searcher's activities. Four of those measures, the number of the unique web pages visited, the time spent on each page, the degree of deviation from the optimal path and the degree of the navigation path's linearity, were found to be good predictors of subjective task difficulty. Objective task complexity was found to affect the relative importance of those predictors and to affect subjective assessment of task difficulty.
Different types of human interaction in online discussion: An examination of using online discussion forum
Authors: Lee Jeong‐Mee
Published: November 2007

The primary purpose of this study is to explore the nature of the use of asynchronous computer‐mediated communication in an online academic learning environment. Additionally the study will provide an analysis of students' participations in discussion forums as well as a construct of the types of patterns of students' interactions in two online classes. A total of 47 students (in two different online classes) evaluated their perception of the discussion forum. Three out of 16 weeks' discussion forum were archived, and a total of 214 postings were examined to find out distinct types of interactions. Four types of interactions were extracted, based upon which, students were asked to rate which type of responses they were most likely to post and which types of interactions they were most likely to respond to. Correlations were examined between types of posts and types of interactions. It was found that there was significant correlation between types of interactions and types of interactions that were likely to be responded to.
Researching wikipedia ‐ current approaches and new directions
Authors: Ayers Phoebe
Published: November 2007

Wikipedia (), an international, multi‐lingual and collaboratively produced free online encyclopedia, has experienced massive growth since its inception in 2001. The site has become the world's single largest encyclopedia as well as one of the world's most diverse online communities. Because of these factors, the site provides a unique view into the processes of collaborative work and the factors that go into producing encyclopedic content. To date, there has been no unified review of the current research that is taking place on and about Wikipedia, and indeed there have been few formal studies of the site, despite its growing importance. This project is a review of social science and information science studies of the site, focusing on research methods and categorizing the areas of the site that have been studied so far. Studies of Wikipedia have focused primarily on the social dynamics of contributors (such as how disputes are resolved and why contributors participate), and the content of Wikipedia (such as whether it is an accurate source), but due to the unique collaborative processes on Wikipedia these two areas are deeply intertwined.
Development of de novo urge incontinence in women post sling: The role of preoperative urodynamics in assessing the risk
Authors: Alperin Marianna , Abrahams‐Gessel Shafika , Wakamatsu May M.
Published: November 2007

Aims

The study was undertaken to investigate if there are specific identifiable risk factors on the preoperative history or urodynamics testing associated with an increased risk for the development of symptoms of de novo urge urinary incontinence after a minimally invasive sling procedure.

Methods

Two hundred eighty‐one women who had undergone minimally invasive sling surgery for stress urinary incontinence between January 2000 and December 2003 were identified. The records of 92 patients were included in this review.

Results

Twenty‐five patients (27%) reported urge urinary incontinence on postoperative questioning. Clinical and urodynamic parameters were correlated with the development of de novo urge urinary incontinence. Preoperative history parameters were not predictive of the increased risk of de novo urge urinary incontinence, with the exception of increased preoperative daytime frequency (OR 3.3 (1.2, 9.1)). Of 16 women whose detrusor pressure during the filling phase of cystometry exceeded 15 cm H2O, de novo urge urinary incontinence developed in 9 (56%) vs. 16 (21%) of 76 women, whose detrusor pressure was ≤ 15 cm H2O (OR 4.6 (1.4, 15.0)).

Conclusions

Directed patient history is only minimally helpful in the identification of women at increased risk for the development of de novo urge urinary incontinence, with the exception of the complaint of increased daytime frequency. Women with elevated detrusor pressure during the filling phase of cystometry were more likely to develop urge urinary incontinence postoperatively. Therefore, we suggest that preoperative urodynamic evaluation, and specifically detrusor pressure > 15 cm H2O may help identify patients at increased risk of developing de novo urge urinary incontinence following the minimally invasive sling procedure. Neurourol. Urodynam. 27:407–411, 2008. © 2007 Wiley‐Liss, Inc.
Types and categories of personal projects: a revelatory means of understanding human occupation
Authors: Brooke Kathleen E , Desmarais Carolyn D , Forwell Susan J
Published: November 2007

Choice of activity and the way it is described may have little to do with the presence of disease and may or may not align with predetermined conceptual or practice frameworks. The present study examines data previously collected by use of Personal Projects Analysis (PPA) in order to compare the types of projects listed by people with and without multiple sclerosis and to compare the categories of projects selected by both groups to those pre‐established in the literature. Secondary analysis tests the differences and similarities in the types of personal projects between two groups, multiple sclerosis (n = 38) and control group (n = 25), matched for demographic characteristics. The analysis compares the categories of personal projects generated by people in both cohorts to pre‐established frameworks. No significant difference was found between the types of personal projects chosen by the two cohorts. For 57.2% of participants the self‐generated categories matched those from the literature, whereas it diverged for 18.2% of the categories of personal projects generated by participants. The study demonstrates that people with and without multiple sclerosis engage in activities that are similar despite the presence of multiple sclerosis, and that category systems should be used cautiously. Copyright © 2007 John Wiley & Sons, Ltd.
Fluoro‐protected carbazole main‐chain polymers as a new class of stable blue emitting polymers
Authors: Kun Harismah , Yi Hunan , Johnson Richard G. , Iraqi Ahmed
Published: November 2007

The protection of the 3,6‐positions of 9‐alkyl‐9H‐carbazole repeat units with fluorine substituents in 2,7‐linked main‐chain polymers as well as in copolymers with triaryl amine repeat units affords blue emitting materials with enhanced electrolytic stability. The electronic conjugation of this new class of materials is more extended than that of the equivalent polymers where the 3,6‐positions are protected with methyl substitutions as a result of the smaller steric hindrance of their fluorine substituents. Attachment of fluorine‐protecting groups at the 3,6‐positions of carbazole repeat units in the homopolymers resulted in materials with relatively high ionization potentials (5.71 eV). However, introduction of triaryl amine comonomers as alternating repeat units provided carbazole/triaryl amine copolymers with a low ionization potential (5.25 eV), a very high quantum yield of fluorescence in solution (0.96), and narrow emission bands [full width at half maximum (FWHM) = 52 nm]. The preparation of this new class of materials together with a study of their electronic and photophysical properties is presented. Copyright © 2007 John Wiley & Sons, Ltd.
Hypoxia‐inducible factor 1α is essential for hypoxic p27 induction in endometrioid endometrial carcinoma
Authors: Horrée N , Gort EH , van der Groep P , Heintz APM , Vooijs M , van Diest PJ
Published: November 2007

Hypoxia‐inducible factor 1α (HIF‐1α) plays an essential role in the adaptive response of cells to hypoxia. The cyclin‐dependent kinase inhibitor p27(Kip1) is highly expressed in the normal endometrium but is lost during endometrial carcinogenesis. However, in high‐grade cancers, p27 re‐expression is observed. We analysed the role of HIF‐1α in hypoxia‐induced expression of p27 in vitro and in vivo in endometrial cancer. Paraffin‐embedded specimens from endometrioid endometrial carcinoma (n = 39) were stained immunohistochemically for HIF‐1α, p27, and Ki67. HEC1B, an endometrial carcinoma cell line, was cultured under normoxic or hypoxic conditions in the presence or absence of transiently expressed short hairpin RNAs targeting HIF‐1α. Protein expression of p27 and HIF‐1α was assessed by western blotting. Immunohistochemical staining revealed perinecrotic HIF‐1α expression in 67% of the cases and p27 staining centrally in the tumour islands, mostly around necrosis, in 46% of the cases. In 50% of the tumours with perinecrotic HIF‐1α expression, p27 and HIF‐1α perinecrotic/central co‐localization was observed. In these tumour sections, hypoxia‐associated p27 expression showed less proliferation around necrosis. Analysis of cultured endometrial carcinoma cells demonstrated that p27 protein expression is induced by hypoxia. This induction was abrogated by transient knockdown of HIF‐1α using RNAi. Furthermore, hypoxia induced cell cycle arrest in HEC1B cells. We conclude that, in endometrioid endometrial carcinoma, p27 re‐expression by hypoxia is HIF‐1α‐dependent and leads to cell cycle arrest. This may contribute to the survival of cancer cells in hypoxic parts of the tumour. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Blood transfusion therapy is feasible in a clinical trial setting in children with sickle cell disease and silent cerebral infarcts
Authors: King Allison A. , Noetzel Michael , White Desirée A. , McKinstry Robert C. , DeBaun Michael R.
Published: November 2007

Background

Silent cerebral infarcts are both morbid and progressive in children with sickle cell disease (SCD). While blood transfusion therapy is effective primary and secondary stroke prevention, the efficacy and acceptance of blood transfusion therapy for children with silent cerebral infarcts is unknown. The overall goals of this study were to determine the feasibility and short‐term efficacy of blood transfusion therapy for silent cerebral infarcts.

Procedure

We conducted a single‐arm feasibility intervention study. Children with SCD and silent cerebral infarcts received blood transfusion therapy. Short‐term efficacy was defined as no progression of MRI findings on repeat MRI.

Results

Ten children enrolled in the study, and nine were evaluable. Five were male. The average age was 10.0 years (range 3.1–16.8). Seven of nine completed the transfusion therapy for over 2 years, with an average duration of therapy of 2.7 years (range 1–6). Twenty infarcts and four cases of Moya Moya were present on the initial MRI. Seven of nine subjects had repeat MRIs. Of these seven, there were a total of 18 infarcts. One infarct increased in size and one case of Moya Moya progressed on repeat MRI. All other lesions were stable or became smaller in diameter while on transfusion therapy during the time of follow up (mean 3.9 years, range 2.1–5.7).

Conclusions

Blood transfusion therapy is a feasible therapy for the prevention of progression of silent cerebral infarcts. Pediatr Blood Cancer 2008;50:599–602. © 2007 Wiley‐Liss, Inc.
High performance thermoplastic composites: Study on the mechanical, thermal, and electrical resistivity properties of carbon fiber‐reinforced polyetheretherketone and polyethersulphone
Authors: Saleem Anjum , Frormann Lars , Iqbal Azhar
Published: November 2007

High temperature processing thermoplastic polymers, polyetheretherketone (PEEK) and polyethersulphone (PES), were melt blended with carbon fibers (CFs) to make composites. These composites were investigated for their mechanical, thermal, and electrical properties. Mechanical properties that are expressed in terms of storage modulus, loss, and damping were enhanced with the addition of CFs. Thermal properties were determined by DSC and TGA. These methods help to understand the effects of fiber content and fiber–matrix adhesion in the composites. Composites were also tested for their electrical and thermal conductivity because CFs leave the composites thermally and electrically conductive. CFs enhanced the crystallinity of the PEEK appreciably that in turn influenced thermal conductivity, electrical resistivity, and the stiffness of PEEK/CF (composites of PEEK with CFs). PES/CF (composites of PES with CF) shows a different behavior due to the amorphous nature of PES. The work involves one filler and two different matrices, and so it provides an interesting comparison of how matrix morphology can influence the properties of composites. POLYM. COMPOS. 28:785–796, 2007. © 2007 Society of Plastics Engineers.
Filler–rubber interactions in α_cellulose‐filled styrene butadiene rubber composites
Authors: Haghighat M. , Khorasani S. Nouri , Zadhoush A.
Published: November 2007

In this study, the interactions between rubber and fillers in α_cellulose‐filled styrene butadiene rubber (SBR) composites were investigated. The results obtained from the tensile and tear strength, abrasion resistance, and hardness indicate that addition of 5‐phr α_cellulose into compound not only does not affect rubber–carbon black bond but improves the mentioned physicomechanical properties. In this study, the type of carbon black was changed from N 330 to N 550. The main purpose of this investigation was to observe the possible changes in physicomechanical properties due to this change. Obtained results show that overall observation of the trends of results do not change with type of carbon black. It can be concluded that the presence of α_cellulose does not have significant influence on the performance of carbon black in the compounds used. POLYM. COMPOS., 28:748–754, 2007. © 2007 Society of Plastics Engineers
Interaction of silica and carbon black fillers with natural rubber/poly(ethylene‐co‐vinyl acetate) matrix by swelling studies
Authors: Sujith A. , Unnikrishnan G. , Radhakrishnan C.K. , Padmini M.
Published: November 2007

The interaction of a black filler and a white filler, which are extensively used in the rubber industry, with natural rubber/poly (ethylene‐co‐vinyl acetate) (NR/EVA) blends vulcanized by DCP has been examined by equilibrium swelling technique. Blends loaded with intermediate super abrasion furnace black (ISAF) and those with silica (SiO2), of same loading, have been used. The silica incorporated blends sorbed a higher amount of aromatic solvents, compared with the ISAF filled blends, when NR was the continuous phase. However, the silica filled systems showed lower sorption characteristics when EVA became the continuous phase. This has been explained in terms of the differences in the interaction between the filler particles and the blend components. The swelling coefficient, diffusion coefficient, and molar mass between crosslinks have been computed to complement the experimental observations. POLYM. COMPOS., 28:705–712, 2007. © 2007 Society of Plastics Engineers
Thermodegradation kinetics of epoxy/DDS/POSS system
Authors: Zhang Zengping , Liang Guozheng , Ren Penggang , Wang Jieliang
Published: November 2007

The thermodegradation kinetics of a hybrid inorganic–organic epoxy system formed by diglycidyl ether of bisphenol A, DGEBA/DDS, modified with octahedral oligomeric silsesquioxane, octa(aminopropylsilsesquioxane) was studied. The average activation energy of thermodegradation of this system was calculated by the integral method developed by Flynn–Wall–Ozawa (E = 105.01 kJ mol−1) and by Coats and Redfern method (E = 113.07 kJ mol−1). Lifetime and half‐life time of the materials system were predicted using the kinetic parameters. The results obtained from the two methods accorded well with each other. POLYM. COMPOS., 28:755–761, 2007. © 2007 Society of Plastics Engineers
Composite screen‐printed thick films for high dielectric constant devices: Bi4Ti3O12–CaCu3Ti4O12 films
Authors: Sabóia K.D.A. , Fechine P.B.A. , Santos M.R.P. , Freire F.N.A. , Pereira F.M.M. , Sombra A.S.B.
Published: November 2007

In this paper, we did a study of the effect of the presence of BIT (Bi4Ti3O12) in the dielectric and optical properties of the CaCu3Ti4O12 (CCTO) thick films. The films were prepared by the solid sate procedure. Mechanical alloying followed by the solid state procedure has been used successfully to produce powders of CaCu3Ti4O12 (CCTO) and BIT (Bi4Ti3O12) to be used in the composites. We also look at the effect of the grain size of the BIT and CCTO in the final properties of the composite film. The samples were studied using X‐Ray diffraction, scanning electron microscopy (SEM), Raman and infrared spectroscopy. We also did a study of the dielectric function (K) and dielectric loss (D) of the films. The role played by the grain size of CCTO and BIT in the dielectric constant and structural properties of the films are discussed. These measurements confirm the potential use of such materials for small high dielectric planar devices. These films are also attractive for capacitor applications and certainly for microelectronics, microwave devices (mobile phones for example), where the miniaturization of the devices is crucial. POLYM. COMPOS., 28:771–777, 2007. © 2007 Society of Plastics Engineers
Origin of deterioration in mechanical properties of glass fiber reinforced nylon 6,6 composites by aqueous ethylene glycol solution
Authors: Hong John Hee , Dhevi D. Manjula , Lee Jong Soon , Kim Kap Jin
Published: November 2007

Glass fiber reinforced nylon 6,6 (GFNY66) composites widely used for automotive applications undergo degradation when repeatedly exposed to aqueous ethylene glycol (EG) solution, resulting in significantly reduced mechanical properties. Hence, it is important to clearly understand the degradation and hydrogen bond breaking mechanism of nylon 6,6 (NY66) and interfacial failure mechanism in GFNY66 (when exposed to aqueous EG solution) in order to improve the mechanical properties of recycled NY66. From ATR‐IR spectra of NY66 immersed in aqueous EG solution at 108°C for varying intervals of time, the shifting of amide‐I band (νCO) at 1640 cm−1 towards lower frequency with increasing immersion time may be attributed to the breakage of intra‐ and intermolecular H‐bonding between amides in NY66 followed by the new formation of H‐bonding between amide group in NY66 and hydroxyl group in the absorbed EG. GPC data revealed the reduction in molecular weight due to the absorption of EG into NY66 matrix leading to chain scission of NY66. GFNY66 samples treated with aqueous EG solution exhibited pronounced deterioration in mechanical properties because of the interfacial failure between glass fiber and NY66 matrix as well as molecular weight reduction caused by the absorbed EG solution. POLYM. COMPOS., 28:778–784, 2007. © 2007 Society of Plastics Engineers
Micromechanical modeling of fiber reinforced composites based on elastoplasticity and its application for 3D braided glass/Kevlar composites
Authors: Kim Ji Hoon , Ryou Hansun , Lee Myoung‐Gyu , Chung Kwansoo , Youn Jae Ryoun , Kang Tae Jin
Published: November 2007

Micromechanical modeling to calculate the mechanical properties of fiber reinforced composites is proposed. To describe the mechanical behavior of the yarn and the matrix, which are the main constituents of fiber reinforced composites, the elastoplastic constitutive law was adopted. In particular, anisotropic elastoplasticity based on Hill's orthotropic yield function and anisotropic kinematic hardening was utilized for the yarn, while the isotropic elastoplastic constitutive law was applied for the matrix. The effective properties of the unit cell in fiber reinforced composites were then calculated based on the finite element method. For verification, the method was successfully applied for 3D braided glass/Kevlar fiber reinforced composites in both linear elastic and nonlinear inelastic ranges. POLYM. COMPOS., 28:722–732, 2007. © 2007 Society of Plastics Engineers
Investigations on the long time behavior of the metastable boron–oxygen complex in crystalline silicon
Authors: Herguth A. , Schubert G. , Kaes M. , Hahn G.
Published: November 2007

Boron and oxygen contamination in Czochralski‐grown (Cz) silicon leads to a degradation of the minority charge carrier lifetime within short times due to the formation of recombination active complexes. The formation of these complexes is investigated for longer times showing a further development of the defect. This development called ‘regeneration’ is triggered by illumination or applied forward voltages and leads to a new state of the defect. This new state of the defect is proven to be less recombination active allowing higher stable minority carrier lifetimes and conversion efficiencies of solar cells. The influences of temperature and light intensity are discussed. Copyright © 2007 John Wiley & Sons, Ltd.