bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Oil Viscosity and Thickness on the Steam Drive
Authors: Doscher Todd M. , Ghassemi Farhad
Published: December 2007

A correlation of steamdrive efficiency, based on model studies, predicts that it will fall as the viscosity of the crude at steam temperature increases. Sensitivity to viscosity results from the overlay of steam, which also mitigates the influence of reservoir thickness. High efficiency, expected of frontal displacement, is realized in the recovery of high-gravity crudes.

Introduction

Physical scaled models of the steam drive have reproduced many features of field operations. One of the most pronounced features of the steam drive is the overlay of steam above the oil column and its subsequent stratified flow to the producing well.

This is in contrast to frontal displacement that was assumed in early analytical models. The effects of various reservoir and operational parameters therefore may be different from those originally deduced on the basis of frontal advance concepts.

Three important parameters used to assess the feasibility of steamdrive operations are (1) rate of injection of steam and its quality, (2) viscosity of the crude oil, and (3) reservoir thickness. The most frequently used analytical model and its modification do not attribute any effect of the crude oil viscosity on the efficiency of the steam drive. Steam zone growth and the corresponding depletion of oil are based exclusively on the way in which heat is distributed within the reservoir. The quality of the steam and its injection rate are both shown to be important, with the resulting oil/steam ratio monotonically increasing with each. On the other hand, field and model studies have indicated that there is an optimal rate of steam injection to attain a maximum oil/steam ratio. The analytical models predict that the efficiency of the steamdrive process as measured by the oil/steam ratio will vary directly with a function of reservoir thickness, whereas results obtained from field operations in which steam stimulation did not contribute significantly to the overall performance suggest that thickness may not have the pronounced effect that is predicted.

The purpose of this work was to elucidate the role of oil viscosity and reservoir thickness in steamdrive operations in which gravity segregation of the steam and its stratified flow dominate the process.

Steamdrive Analysis Based on Stratified Steam Flow

Steam initially enters a viscous oil reservoir through a depleted or wet interval, a fracture, or a fluidized interval. If the initial entry is not at the top of the oil section, the steam rapidly migrates upward because of the strong gravitational gradients imposed by the marked difference in density between the steam and the reservoir fluids. The rate of upward migration depends on vertical permeability and viscosity of the crude oil at steam temperature - that is, the concurrent drainage rate of the heated crude oil.

JPT

P. 291^
Dynamic Fracture of Natural Rubber
Authors: Al-Quraishi Ali A. , Hoo Fatt Michelle S.
Published: December 2007

This paper illustrates how the fracture energy of a tensile strip made of unfilled and 25 phr carbon black-filled natural rubber varies with far-field strain rate in the range 0.01–71 s−1. Quasistatic and dynamic fracture tests were performed at room temperature with an electromechanical INSTRON machine, a servo-hydraulic MTS machine, and Charpy tensile apparatus, respectively. It was found that the fracture energy of the unfilled natural rubber did not vary significantly over the range of sample strain rate, but there was significant variation in the fracture energy of the 25 phr carbon black-filled natural rubber from 0.01 to 71 s−1 sample strain rate. The fracture energy of the 25 phr carbon black-filled natural rubber at a sample strain rate of 0.1 s−1 was about three times greater than it was at the 10 s−1 sample strain rate. While the carbon black fillers increased the fracture energy of natural rubber by about 200% at quasistatic sample strain rates (0.01–0.1 s−1) and at 71 s−1, the carbon black fillers did nothing to improve the fracture energy of natural rubber at sample strain rates between 5 and 29 s−1. In this strain rate range, the fracture energy of 25 phr carbon black-filled natural rubber was almost the same as that in the unfilled natural rubber. The variation in the fracture energy with far-field strain rate was due to changes in the material behavior of natural rubber at high strain rates. Finite element analysis using a high-strain-rate constitutive equation for the 25 phr carbon black rubber specimen was used to calculate the fracture energy of the specimen at a sample strain rate of 55 s−1, and good agreement was found between the test and finite element results.
Associations between teat injuries and fistula formation in lactating dairy cows treated with surgery
Authors: Azizi Saeed , Rezaei Farshid Sarrafzadeh , Saifzadeh Siamak , Dalir-Naghadeh Bahram
Published: December 2007

Objective—To determine associations between rate of fistula formation and parity, lactation period, wound age, wound location, and shape of teat injuries in surgically treated teats in dairy cows.

Study Design—Prospective clinical study.

Animals—106 lactating dairy cows with teat lacerations.

Procedures—Lacerations were classified via shape, location, and age. Associations between potential risk factors and fistula formation were analyzed. Seasonal distribution, type of injured teat, parity, and days in lactation were determined.

Results—Cows with teat injury in their first and second parity had 4.1 times the odds of fistula formation, compared with cows with parity ≥ 3.Teats sutured within 48 to 72 hours of injury had 8.3 times the odds of fistula formation, compared with teats sutured within the first 24 hours. Cows in early lactation stage (first 60 days of lactation) were more susceptible to teat injuries. Occurrence of teat injury was greater at the third, fourth, and fifth parity.

Conclusions and Clinical Relevance—Season, parity, and lactation period were associated with prevalence of teat injury in lactating dairy cows in a range system. Neither the type of suture material used nor the suturing technique was associated with effects on healing of the operated full-thickness teat wounds. Factors such as parity and age of the wound can be associated with delay in the healing process, which may result in fistula formation.
Interdisciplinary Curricula in Middle and High School Classrooms: Case Studies of Approaches to Curriculum and Instruction
Authors: Applebee Arthur N. , Adler Mary , Flihan Sheila
Published: December 2007

This study examines 11 interdisciplinary teams involving 30 teachers and 542 students in New York and California. The teams represented an array of approaches to interdisciplinary curricula, ranging from simple correlation to major reconstrual of the contributing disciplines. Teams that engaged in the most reconstrual of traditional content also tended to use instructional approaches that emphasized cognitively engaging instruction, including an emphasis on envisionment-building activities and extended discussion of significant ideas, but individual members of teaching teams still varied considerably in teaching style. The study concludes that interdisciplinary coursework is neither a problem nor a solution in efforts to increase student achievement; rather, it involves a number of tradeoffs that need to be considered at the school site.
The Effect of Neighborhood Context on the College Aspirations of African American Adolescents
Authors: Stewart Endya B. , Stewart Eric A. , Simons Ronald L.
Published: December 2007

Previous research on educational aspirations has focused almost exclusively on micro-level predictors of educational aspirations. Notably absent from these studies are measures reflecting the neighborhood context in which adolescents live. Drawing on Wilson’s theory of neighborhood effects, the present study examines the extent to which neighborhood structural disadvantage predicts college aspirations among African American adolescents. The results show that concentrated neighborhood disadvantage exerts a significant influence on college aspirations, even when accounting for the micro-level context of adolescents. Overall, the findings suggest that living in a disadvantaged context lowers college aspirations among African American adolescents.
Strategic Transformation: Cultural and Gender Identity Negotiation in First-Generation Vietnamese Youth
Authors: Stritikus Tom , Nguyen Diem
Published: December 2007

This article explores the various ways in which recent Vietnamese immigrant students form cultural and gender identities as they transition to U.S. schooling. Using data from a 2-year qualitative study that tracked the social and academic adjustment processes of recent Vietnamese immigrant youth, this article examines the tensions that students struggle with as they bring their own values and practices into the school site. The findings suggest that gender functions as a complex social category for recent immigrants that shifts across social contexts. The authors argue that accounting for a full picture of gender identity more accurately captures the manner in which recent immigrant students adapt to U.S. schooling.
Updated Recommendations from the Canadian National Consensus Meeting on HER2/neu Testing in Breast Cancer
Authors: Hanna W. , O’Malley F.P. , Barnes P. , Berendt R. , Gaboury L. , Magliocco A. , Pettigrew N. , Robertson S. , Sengupta S. , Têtu B. , Thomson T.
Published: December 2007

Testing for HER2/neu in breast cancer at the time of primary diagnosis is now the standard of care. Accurate and standardized testing methods are of prime importance to ensure the proper classification of the patient’s HER2/neu status. A meeting of pathologists from across Canada was convened to update the Canadian HER2/neu testing guidelines. This National HER2/neu Testing Committee reviewed the recently published American Society of Clinical Oncology/ College of American Pathologists (ASCO/CAP) guidelines for HER2/neu testing in breast cancer. The updated Canadian HER2/neu testing guidelines are based primarily on the ASCO/CAP guidelines, with some modifications. It is anticipated that widespread adoption of these guidelines will further improve the accuracy of HER2/neu testing in Canada.
Generalized scaling on forecasting heating patterns for microwave processing
Authors: Bhattacharya Madhuchhanda , Basak Tanmay
Published: December 2007

A closed form analysis based on Finite Fourier Transformation (FFT) has been carried out to predict the heating characteristics in the presence of microwave induced volumetric heat sources. A scaling analysis shows that temperature distributions within a material during microwave heating evolve in two stages, namely small time and large time. The inverse of square of second eigenvalue along with thermal diffusivity determines the threshold time scale between these two regimes. During small time evolution, the spatial temperature distribution follows absorbed power profiles, whereas the temperature distributions are slaved by first eigenfunction and independent of volumetric heat distribution at large time evolution. In all the cases, the variation of temperature within the material is guided by a dimensionless number NG = L2q0/kTref. For NG ≪ 1, almost uniform temperature distributions are attained and a lump parameter model can be used. In contrast, nonuniformity in absorbed power distributions amplifies in temperature distribution for materials with NG ≫ 1, where there exists a possibility of local hot spot formation if absorbed power exhibits local maxima. The applicability of this analysis has been illustrated to forecast heating characteristics within various materials © 2007 American Institute of Chemical Engineers AIChE J, 2008
Fluidization of coated group C powders
Authors: Chen Yuhua , Yang Jun , Dave Rajesh N. , Pfeffer Robert
Published: December 2007

While it is well known that flow aids such as fumed silica can be added to improve flowability and fluidizability of cohesive powders, the improvements observed depend on how well the flow aids are blended together with the cohesive powders. In this work, dry particle coating is used to deposit a very small amount of nano‐sized particles (as low as 0.01 wt %) with a high degree of precision onto the surface of cohesive, Geldart Group C powders to make them fluidize like Group A powders. A model taking into account the effect of the size of the guest and host particles as well as surface area coverage (SAC) of the coated nano‐sized particles is developed to predict the effect of coating on the adhesion reduction of cohesive powders. A series of experiments are performed to investigate the improvement in the fluidizability of dry particle coated Group C powders (e.g., cornstarch and aluminum), and the effect of various parameters such as SAC, guest particle size and host particle size are systematically investigated. The results clearly show the effect of each of these parameters on the fluidization behavior of cohesive powders, and also validate the model. The study also indicates that a critical SAC is required to make the coated cornstarch fluidize, which is about 5%; the smaller the guest size, the better its effect on improved fluidizability, although the improvement is reduced if the guest size is smaller than about 10 nm; and if the conditions regarding the SAC and guest size are satisfied, dry particle coating will significantly improve the fluidization of cohesive particles even as small as 5–10 μm. © 2007 American Institute of Chemical Engineers AIChE J, 2008
DMD pseudoexon mutations: splicing efficiency, phenotype, and potential therapy
Authors: Gurvich Olga L. , Tuohy Therese M. , Howard Michael T. , Finkel Richard S. , Medne Livija , Anderson Christine B. , Weiss Robert B. , Wilton Steve D. , Flanigan Kevin M.
Published: December 2007

Objective

The degenerative muscle diseases Duchenne (DMD) and Becker muscular dystrophy result from mutations in the DMD gene, which encodes the dystrophin protein. Recent improvements in mutational analysis techniques have resulted in the increasing identification of deep intronic point mutations, which alter splicing such that intronic sequences are included in the messenger RNA as “pseudoexons.” We sought to test the hypothesis that the clinical phenotype correlates with splicing efficiency of these mutations, and to test the feasibility of antisense oligonucleotide (AON)–mediated pseudoexon skipping.

Methods

We identified three pseudoexon insertion mutations in dystrophinopathy patients, two of whom had tissue available for further analysis. For these two out‐of‐frame pseudoexon mutations (one associated with Becker muscular dystrophy and one with DMD), mutation‐induced splicing was tested by quantitative reverse transcription polymerase chain reaction; pseudoexon skipping was tested using AONs composed of 2′‐O‐methyl–modified bases on a phosphorothioate backbone to treat cultured primary myoblasts.

Results

Variable amounts of pseudoexon inclusion correlates with the severity of the dystrophinopathy phenotype in these two patients. AON treatment directed at the pseudoexon results in the expression of full‐length dystrophin in a DMD myoblast line.

Interpretation

Both DMD and Becker muscular dystrophy can result from out‐of‐frame pseudoexons, with the difference in phenotype being due to variable efficiency of the newly generated splicing signal. AON‐mediated pseudoexon skipping therapy is a viable approach to these patients and would be predicted to result in increased expression of wild‐type dystrophin protein. Ann Neurol 2007
Modified use of team‐based learning for effective delivery of medical gross anatomy and embryology
Authors: Vasan Nagaswami S. , DeFouw David O. , Holland Bart K.
Published: December 2007

Team‐based learning (TBL) is an instructional strategy that combines independent out‐of‐class preparation for in‐class discussion in small groups. This approach has been successfully adopted by a number of medical educators. This strategy allowed us to eliminate anatomy lectures and incorporate small‐group active learning. Although our strategy is a modified use of classical TBL, in the text, we use the standard terminology of TBL for simplicity. We have modified classical TBL to fit our curricular needs and approach. Anatomy lectures were replaced with TBL activities that required pre‐class reading of assigned materials, an individual self‐assessment quiz, discussion of learning issues derived from the reading assignments, and then the group retaking the same quiz for discussion and deeper learning. Students' performances and their educational experiences in the TBL format were compared with the traditional lecture approach. We offer several in‐house unit exams and a final comprehensive subject exam provided by the National Board of Medical Examiners. The students performed better in all exams following the TBL approach compared to traditional lecture‐based teaching. Students acknowledged that TBL encouraged them to study regularly, allowed them to actively teach and learn from peers, and this served to improve their own exam performances. We found that a TBL approach in teaching anatomy allowed us to create an active learning environment that helped to improve students' performances. Based on our experience, other preclinical courses are now piloting TBL. Anat Sci Ed 1:3–9, 2008. © 2007 American Association of Anatomists.
Designing patient‐focused information: An opportunity for communicating anatomically related information
Authors: Evans Darrell J.R.
Published: December 2007

Literature clearly demonstrates that there has been a large increase in the time devoted to teaching oral communication skills within medical curricula worldwide. In contrast, the ability to communicate with patients through written means does not appear to be a feature in many programmes, despite its fundamental importance in creating understanding of medicine within the general population. This article investigates one way patient‐centered written communication has been integrated into part of the early training years of medical students using anatomically related material as a focus. Following a series of interactive seminars and debates as part of a student‐selected component, students were asked to prepare a patient‐focused information leaflet on a particular birth defect. The leaflets included aspects of anatomy and embryology as well as causes of the birth defect, signs and symptoms, treatments, outlook, and support mechanisms. Evaluation of the leaflets using set marking criteria and readability indexes showed that students had successfully targeted the chosen audiences. Feedback showed that the component was rated highly by the students in terms of quality, usefulness, and interest. Students viewed sessions as an excellent forum for appreciating the importance of and developing their own effective written communication skills. It is hoped that such developments will enhance the capacity of all potential doctors to communicate more effectively with patients and colleagues in both the written and spoken form. Anat Sci Ed 1:41–45, 2008. © 2007 American Association of Anatomists.
Tracheobronchial cast production and use in an undergraduate human anatomy course
Authors: Cope Lee Anne
Published: December 2007

Silastic E RTV silicone was used to produce tracheobronchial cast for use in an undergraduate human anatomy course. Following air‐drying, the trachea and lungs were injected with E RTV silicone and allowed to cure for 24 hr. The parenchyma was then removed from the tracheobronchial cast by maceration and boiling and then whitened in a 10% solution of hydrogen peroxide. The result was an anatomical replica that illustrates the branching pattern of the tracheobronchial tree and looks very similar to human even though canine lungs were used. In addition, this cast is very flexible and durable enough to stand up to repeated student handling. Anat Sci Ed 1:23–26, 2008. © 2007 American Association of Anatomists.
A minimally invasive approach to undergraduate anatomy teaching
Authors: Gogalniceanu Petrut , Madani Hardi , Paraskeva Paraskevas A. , Darzi Ara
Published: December 2007

Anatomy is one of the cornerstones of medical education. Unfortunately, sufficient evidence has accumulated to suggest a worldwide decline in the resources and time allocated to its teaching. Integration of anatomy with clinical medicine has been frequently advocated as the solution to this academic crisis. Consequently, new ways of harnessing clinical relevance to the teaching of anatomy must be sought to make it applicable to contemporary clinical practice. Human cadavers have been used to teach laparoscopic skills to surgical trainees for some time. More recently, centers in the United States have piloted the use of minimally invasive techniques in the teaching of anatomy to undergraduates. We believe that the use of laparoscopy on human cadavers may also be used to complement the teaching of anatomy to United Kingdom and European medical students. This would not only familiarize students with the topography and morphology of human anatomy, but also with the concept of manipulating anatomical structures to achieve a clinical outcome. Other benefits include improved three‐dimensional orientation, increased dexterity, and development team‐working skills amongst students. A UK feasibility study is currently underway. Anat Sci Ed 1:46–47, 2008. © 2007 American Association of Anatomists.
A publication power approach for identifying premier information systems journals
Authors: Holsapple Clyde W.
Published: December 2007

Stressing that some universities have adopted unrealistic requirements for tenure of information systems (IS) faculty members, a recent editorial in MIS Quarterly contends that the group of premier IS journals needs to be generally recognized as having more than just two members. This article introduces the publication power approach to identifying the premier IS journals, and it does indeed find that there are more than two. A journal's publication power is calculated from the actual publishing behaviors of full‐time, tenured IS faculty members at a sizable set of leading research universities. The underlying premise is that these researchers produce excellent work, collectively spanning the IS field's subject matter, and that the greatest concentrations of their collective work appear in highest visibility, most important journals suitable for its subject matter. The new empirically based approach to identifying premier IS journals (and, more broadly, identifying journals that figure most prominently in publishing activity of tenured IS researchers) offers an attractive alternative to promulgations by individuals or cliques (possibly based on outdated tradition or vested interests), to opinion surveys (subjective, possibly ill‐informed, vague about rating criteria, and/or biased in various ways), and to citation analyses (which ignore semantics of references and, in the case of ISI impact factors, have additional problems that cast considerable doubt on their meaningfulness within the IS field and its subdisciplines). Results of the publication power approach can be applied and supplemented according to needs of a particular university in setting its evaluation standards for IS tenure, promotion, and merit decisions.
Trust in digital information
Authors: Kelton Kari , Fleischmann Kenneth R. , Wallace William A.
Published: December 2007

Trust in information is developing into a vitally important topic as the Internet becomes increasingly ubiquitous within society. Although many discussions of trust in this environment focus on issues like security, technical reliability, or e‐commerce, few address the problem of trust in the information obtained from the Internet. The authors assert that there is a strong need for theoretical and empirical research on trust within the field of information science. As an initial step, the present study develops a model of trust in digital information by integrating the research on trust from the behavioral and social sciences with the research on information quality and human– computer interaction. The model positions trust as a key mediating variable between information quality and information usage, with important consequences for both the producers and consumers of digital information. The authors close by outlining important directions for future research on trust in information science and technology.
Authority and ranking effects in data fusion
Authors: Spoerri Anselm
Published: December 2007

This paper provides empirical support for some of the key assumptions guiding the design of data fusion methods. It computes and analyzes the overlap structures between the search results of retrieval systems that participated in the short, long, and manual tracks in TREC 3, 6, 7, and 8 to examine what can be learned to infer a document's probability of being relevant. This paper shows that the potential relevance of a document increases exponentially as the number of systems retrieving it increases—called the Authority Effect. It also shows that documents higher up in ranked lists and found by more systems are more likely to be relevant—called the Ranking Effect. A contribution of this paper is that it shows that the Authority and Ranking Effects can be observed regardless of whether a query is generated manually or automatically and short or long queries are used. Further, it is illustrated that the Authority and Ranking Effects can be observed if the result sets of random groupings of five retrieval systems are compared and only the top 50 results are used in the overlap computation. Also discussed is how the Authority and Ranking Effects can help explain why major data fusion methods perform well.
catena‐Phosphorus Cations
Authors: Dyker C. Adam , Burford Neil
Published: December 2007

Recent advances towards a systematic development of catena‐phosphorus cations are reviewed. The cations represented in this new and developing chapter in fundamental phosphorus chemistry complement the series of neutral and anionic polyphosphorus compounds.
A Dicationic Organoplatinum(II) Complex Containing a Bridging 2,5‐Bis‐(4‐ethynylphenyl)‐[1,3,4]oxadiazole Ligand Behaves as a Phosphorescent Gelator for Organic Solvents
Authors: Lu Wei , Law Yuen‐Chi , Han Jie , Chui Stephen Sin‐Yin , Ma Dik‐Lung , Zhu Nianyong , Che Chi‐Ming
Published: December 2007

A dicationic platinum(II) terpyridyl complex, [(tBu3tpy)Pt(OXD)Pt(tBu3tpy)](PF6)2 (tBu3tpy=4,4′,4“‐tri‐tert‐butyl‐2,2′:6′,2”‐terpyridyl, OXD=2,5‐bis(4‐ethynylphenyl)[1,3,4]oxadiazole) formed phosphorescent organogels in acetonitrile or in a mixture of acetonitrile and alcohol. The structure and properties of these emissive gels were analyzed by polarizing optical and confocal laser scanning microscopy, and by variable‐temperature 1H NMR, UV/Vis, and emission spectroscopy. Dry gels were studied by scanning electron microscopy, powder X‐ray diffraction (PXRD), and small‐angle X‐ray scattering (SAXS). SEM images of the dry gel revealed a network of interwoven nanofibers (diameter 12–60 nm, length>5 μm). Intermolecular π–π interactions between the [(tBu3tpy)PtC≡C] moieties could be deduced from the variable 1H NMR spectra. The PXRD and SAXS data showed that the assembly of the gelator could be represented by a rectangular 2D lattice of 68 Å × 14 Å. The ability of the complex to gelate a number of organic solvents is most likely due to intermolecular π–π interactions between the [(tBu3tpy)PtC≡C] moieties.
DC motor speed control methods using MATLAB/Simulink and their integration into undergraduate electric machinery courses
Authors: Ayasun Saffet , Karbeyaz Gültekin
Published: December 2007

This paper describes the MATLAB/Simulink realization of the DC motor speed control methods, namely field resistance, armature voltage and armature resistance control methods, and feedback control system for DC motor drives. These simulation models are developed as a part of a software laboratory to support and enhance undergraduate electric machinery courses at Nigde University, Nigde, Turkey. © 2007 Wiley Periodicals, Inc. Comput Appl Eng Educ 15: 347–354, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20151
The stone that struck Goliath: The Part‐Time Faculty Association, Washington State Community and Technical Colleges, and class‐action lawsuits
Authors: Ruiz Eddy A.
Published: December 2007

This chapter explores recent legal challenges and victories brought forth by part‐time community college faculty in Washington State in an effort to attain equity and social justice.
Part‐time faculty satisfaction across missions and disciplines
Authors: Wagoner Richard L.
Published: December 2007

This chapter explores community college faculty satisfaction related to four specific variables.
Hypervalent Silicon versus Carbon: Ball‐in‐a‐Box Model
Authors: Pierrefixe Simon C. A. H. , Fonseca Guerra Célia , Bickelhaupt F. Matthias
Published: December 2007

Why is silicon hypervalent and carbon not? Or why is [ClCH3Cl]− labile with a tendency to localize one of its axial CCl bonds and to largely break the other one, while the isostructural and isoelectronic [ClSiH3Cl]− forms a stable pentavalent species with a delocalized structure featuring two equivalent SiCl bonds? Various hypotheses have been developed over the years focusing on electronic and steric factors. Here, we present the so‐called ball‐in‐a‐box model, which tackles hypervalence from a new perspective. This model reveals the key role of steric factors and provides a simple way of understanding the above phenomena in terms of different atom sizes. Our bonding analyses are supported by computation experiments in which we probe, among other things, the shape of the SN2 potential‐energy surface of Cl− attacking a carbon atom in the series of substrates CH3Cl, .CH2Cl, ..CHCl, and ...CCl. Our findings for ClCH3Cl− and ClSiH3Cl− are generalized to other Group 14 central atoms (Ge, Sn, and Pb) and axial substituents (F).
Ethenolysis of Methyl Oleate in Room‐Temperature Ionic Liquids
Authors: Thurier Cyril , Fischmeister Cédric , Bruneau Christian , Olivier‐Bourbigou Hélène , Dixneuf Pierre H.
Published: December 2007

Unsaturated vegetable oils are an attractive renewable feedstock, and the selective cleavage of unsaturated fatty esters is an important transformation in this respect. The efficient and selective cross‐metathesis of methyl oleate with ethylene was achieved under mild conditions with ruthenium‐alkylidene catalysts in toluene and room‐temperature ionic liquids (RTILs) to give two important chemical intermediates, 1‐decene and methyl 9‐decenoate, without double‐bond migration. As recovery of the catalyst is an important target with respect to industrial applications, catalyst recycling studies were also carried out in RTILs with the first‐generation Hoveyda catalyst.
A Bis(C60)–Bis(phthalocyanine) Nanoconjugate: Synthesis and Photoinduced Charge Transfer
Authors: Kahnt Axel , Quintiliani Maurizio , Vázquez Purificación , Guldi Dirk M. , Torres Tomás
Published: December 2007

A novel dimeric phthalocyanine–C60 nanoconjugate, consisting of a bisphthalocyanine core to which two fullerenes are attached, has been prepared. The synthetic strategy implemented the preparation of a diformyl butadiynyl‐bridged bisphthalocynaninatozinc(II) complex by means of palladium‐catalyzed cross‐coupling reactions and subsequent dipolar cycloaddition reactions. Photophysical experiments confirm that an intramolecular electron transfer, namely, from the photoexcited ZnPc moiety to the electron‐accepting C60 unit, governs the overall photoreactivity of the nanoconjugate. Through‐space charge‐transfer interactions facilitated by the close proximity of the ZnPc and the C60 moieties play a decisive role in determining the lifetimes of the charge‐separated state which range from 10−10 to 10−9 seconds.
A Highly Active Aqueous Olefin Metathesis Catalyst Bearing a Quaternary Ammonium Group
Authors: Gułajski Łukasz , Michrowska Anna , Narożnik Joanna , Kaczmarska Zuzanna , Rupnicki Leszek , Grela Karol
Published: December 2007

A polar olefin metathesis catalyst that bears a quaternary ammonium group was prepared from commercially available reagents. The electron‐withdrawing quaternary ammonium group not only activates the Ru catalyst electronically but at the same time makes the catalyst more hydrophilic. The catalyst can therefore be efficiently used both in traditional media, such as dichloromethane and toluene, as well as in technical‐grade alcohols, alcohol–water mixtures and in neat water. Various metathesis reactions, including ring‐closing, cross‐ and enyne metathesis, were conducted in these solvents in the presence of air. In addition, the Ru catalyst can act as an inisurf (initiator and surfactant) molecule, promoting metathesis under heterogeneous aqueous conditions.
Differential growth and multicellular villi direct proepicardial translocation to the developing mouse heart
Authors: Rodgers Laurel S. , Lalani Sofia , Runyan Ray B. , Camenisch Todd D.
Published: December 2007

In the mammalian system the proepicardium (PE) arises from mesothelium of the septum transversum before translocation to the heart where it forms the epicardium and progenitor cells of the coronary vessels. Despite its importance, the process in which PE cells translocate to the myocardium in mammals is not well defined. The current paradigm states that cellular cysts of PE float across the pericardial space and contact the outer surface of the myocardium. This mechanism does not provide a satisfactory explanation for the directionality or localization of PE migration. To better define PE migration, we performed a detailed study of mouse PE development. We provide thorough documentation that redefines the size of the PE migratory field and the mechanism of migration. Our new model incorporates differential growth and direct contact between multicellular PE villi and the myocardium as mechanisms in formation of the epicardium. Developmental Dynamics 237:145–152, 2008. © 2007 Wiley‐Liss, Inc.
The Use of Solid‐Phase Synthesis Techniques for the Preparation of Peptide–Metal Complex Conjugates
Authors: Dirscherl Georg , König Burkhard
Published: December 2007

This microreview summarizes recent reports on the preparation of metal complex peptide conjugates by solid‐phase synthesis methods. Procedures for such conjugates are in many cases different from standard solid‐phase peptide synthesis protocols. Specific advantages of general strategies, the synthesis of peptide–ligand conjugates and complexation with excess metal ions on solid support or the incorporation of previously prepared metal complex amino acid derivatives are discussed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Erratum: Evaluation of Bayesian models for focused clustering in health data
Authors: Ma Bo , Lawson Andrew B. , Liu Yuan
Published: December 2007

Volume 18, Issue 8, Pages 871–887 (December 2007)

DOI: 10.1002/env.850

The above paper was published including an error. Within the ‘Acknowledgement’ Section on page 14, the NIH grant number is incorrect. The correct number should be as follows: NIH 1R01CA095979‐2.
Accuracy of technetium‐99m SPECT‐CT hybrid images in predicting the precise intraoperative anatomical location of parathyroid adenomas
Authors: Harris Luke , Yoo John , Driedger Albert , Fung Kevin , Franklin Jason , Gray Daryl , Holliday Ronald
Published: December 2007

Background.

This study evaluated the accuracy of single photon emission computed tomography (SPECT)‐CT imaging for the preoperative localization of parathyroid adenomas.

Methods.

This study included both a quantitative and qualitative accuracy measure. The quantitative measure was the distance between the location of the adenoma on the SPECT‐CT scan and the location of the adenoma intraoperatively. Qualitatively, surgeons were asked whether or not the adenoma was in the exact location predicted by the SPECT‐CT scan. The time from initial incision to identification of the parathyroid was recorded. Patients referred to London Health Sciences Centre for a suspected parathyroid adenoma were eligible for this study.

Results.

Twenty‐three patients participated in this study. Eighteen (78.3%) had a single adenoma, 2 (8.7%) had double adenomas, and 3 (13.0%) had multiglandular hyperplasia. SPECT‐CT correctly detected and localized 16 of 18 (88.9%) cases of single parathyroid adenomas. The mean distance between the location of the adenoma on the SPECT‐CT scan and the location of the adenoma intraoperatively was 16.3 mm (95% ≤ 19.0 mm). For single adenomas, the median time from skin incision to identification was 14 minutes (range, 8–40 minutes). The preoperative detection and localization of a single focus of sestamibi uptake yielded a parathyroid adenoma in the specified location in 80.0% of cases (95% CI, 97.4–66.5%).

Conclusions.

SPECT‐CT predicted the intraoperative location of a single parathyroid adenoma within 19.0 mm with 95% confidence. The correct detection and localization of multiglandular disease remains difficult. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Biology and pathobiology of gap junctional channels in hepatocytes
Authors: Vinken Mathieu , Henkens Tom , De Rop Evelien , Fraczek Joanna , Vanhaecke Tamara , Rogiers Vera
Published: December 2007

The present review provides the state of the art of the current knowledge concerning gap junctional channels and their roles in liver functioning. In the first part, we summarize some relevant biochemical properties of hepatic gap junctional channels, including their structure and regulation. In the second part, we discuss the involvement of gap junctional channels in the occurrence of liver cell growth, liver cell differentiation, and liver cell death. We further exemplify their relevance in hepatic pathophysiology. Finally, a number of directions for future liver gap junctional channel research are proposed, and the up-regulation of gap junctional channel activity as a novel strategy in (liver) cancer therapy is illustrated.
Prolonged glucocorticoid treatment decreases cannabinoid CB1 receptor density in the hippocampus
Authors: Hill Matthew N. , Carrier Erica J. , Ho W.‐S. Vanessa , Shi Leyu , Patel Sachin , Gorzalka Boris B. , Hillard Cecilia J.
Published: December 2007

Experimental studies indicate a bidirectional, functional relationship between glucocorticoids and the endocannabinoid system; however, the effects of repeated glucocorticoid treatment on the endocannabinoid system have not been examined. In this study, we treated male rats with either a single dose or a 21‐day course of treatment with corticosterone (20 mg/kg) and measured hippocampal cannabinoid CB1 receptor expression and endocannabinoid content. The 21‐day, but not the single, administration of corticosterone significantly reduced both the binding site density and amount of protein of the hippocampal cannabinoid CB1 receptor without affecting affinity for the CB1 receptor agonist, [3H]CP55940. With regard to hippocampal endocannabinoid content, acute corticosterone treatment resulted in a significant reduction in anandamide but did not affect 2‐arachidonylglycerol, while repeated corticosterone treatment did not alter content of either anandamide or 2‐arachidonylglycerol. These data support the hypothesis that the cannabinoid CB1 receptor is under negative regulation by glucocorticoids in the hippocampus, and suggest that hippocampal cannabinoid CB1 receptor signaling could be reduced under conditions associated with hypersecretion of glucocorticoids, such as chronic stress. © 2007 Wiley‐Liss, Inc.
Leptin and leptin receptor genotypes and colon cancer: Gene–gene and gene–lifestyle interactions
Authors: Slattery Martha L. , Wolff Roger K. , Herrick Jennifer , Caan Bette J. , Potter John D.
Published: December 2007

Leptin may play an important role in colorectal cancer because of its role in energy balance, insulin and inflammation. We evaluated the LEP rs2167270 (19 G > A) and rs7799039 (−2548 G > A) polymorphisms and the leptin receptor, LEPR rs6588147 (located in intron 2), polymorphism with risk of developing colon cancer in a study of 1,567 cases and 1,965 controls. We evaluated the effects of the polymorphisms with body mass index (BMI), recent use of aspirin/NSAIDs and genetic variations in genes related to insulin signaling pathways including insulin‐like growth factor 1 (IGF1), insulin‐like growth factor binding protein 3 (IGFBP3), and insulin‐related substrates 1 and 2 (IRS1, IRS2) and the vitamin D receptor (VDR). We observed a slight reduction in colon cancer risk with the AA LEP rs2167270 genotype (OR 0.79 95% CI 0.64, 0.98) and although not reaching statistical significance, with the combined GG LEP rs2167270 and GG LEPR rs6588147 (OR 0.70, 95% CI 0.49, 1.02) genotypes. BMI did not interact with any of these polymorphisms to alter colon cancer risk. However, recent aspirin/NSAID use significantly interacted with both LEP polymorphisms. Likewise, variants of IGF1 and IRS2 interacted with the LEP rs2167270 polymorphism. VDR polymorphisms interacted with all LEP and LEPR polymorphisms. These data support an association between LEP and colon cancer. They also suggest that the mechanisms linking leptin to colon cancer may be independent of energy balance. © 2007 Wiley‐Liss, Inc.
Frequent epigenetic inactivation of hSRBC in gastric cancer and its implication in attenuated p53 response to stresses
Authors: Lee Jin‐Hee , Byun Do‐Sun , Lee Min‐Goo , Ryu Byung‐Kyu , Kang Min‐Ju , Chae Kwon‐Seok , Lee Kil Yeon , Kim Hyo‐Jong , Park Heonyong , Chi Sung‐Gil
Published: December 2007

hSRBC is a putative tumor suppressor located at 11p15.4, at which frequent genomic loss has been observed in several human malignancies. To explore the candidacy of hSRBC as a suppressor of gastric tumorigenesis, we analyzed the expression and mutation status of hSRBC in gastric tissues and cell lines. hSRBC transcript was expressed in all normal and benign tumor tissues examined, but undetectable or very low in 73% (11/15) cancer cell lines and 41% (46/111) primary tumors. Loss or reduction of hSRBC expression was tumor‐specific and correlated with stage and grade of tumors. While allelic loss or somatic mutations of the gene were infrequent, its expression was restored in tumor cells by 5‐aza‐2′‐deoxycytidine treatment and aberrant hypermethylation of 23 CpG sites in the promoter region showed a tight association with altered expression. Transient or stable expression of hSRBC led to a G1 cell cycle arrest and apoptosis of tumor cells, and strongly suppresses colony forming ability and xenograft tumor growth. In addition, hSRBC elevated apoptotic sensitivity of tumor cells to genotoxic agents, such as 5‐FU, etoposide and ultraviolet. Interestingly, hSRBC increased the protein stability of p53 and expression of p53 target genes, such as p21Waf1, PUMA and NOXA, while hSRBC‐mediated cell cycle arrest and apoptosis were abolished by blockade of p53 function. Our findings suggest that hSRBC is a novel tumor suppressor whose epigenetic inactivation contributes to the malignant progression of gastric tumors, in part, through attenuated p53 response to stresses. © 2007 Wiley‐Liss, Inc.
HPP1‐mediated tumor suppression requires activation of STAT1 pathways
Authors: Elahi Abul , Zhang Li , Yeatman Timothy J. , Gery Sigal , Sebti Said , Shibata David
Published: December 2007

HPP1 is a recently discovered gene that is epigenetically silenced in a number of tumor types, suggesting a potential role as a tumor suppressor. However, whether HPP1 has tumor suppressor activity is not clearly known. We have sought to investigate the effects of HPP1 on tumor growth and survival and to identify signaling pathways that mediate HPP1's mechanism of action. Forced expression of HPP1 into HCT116 colon cancer cell lines blocked the ability of HCT116 tumors to grown in vivo in nude mice. In cell culture, ectopic expression of HPP1 induces apoptosis and potently inhibits soft agar colony formation. HPP1 overexpression was also associated with a moderate reduction in in vitro proliferation characterized by an accumulation of cells in the G0/G1 phase of the cell cycle. Microarray analysis revealed that ectopic expression of HPP1 resulted in a dramatic upregulation of STAT1 as well as a large number of associated interferon‐inducible genes. RNA interference‐mediated abrogation of STAT1 reversed HPP1's antiproliferative effects. We conclude that HPP1 demonstrates tumor suppressive and pro‐apoptotic activity, both in vitro and in vivo. Coupled with its inactivation in a number of tumor types, our data provides evidence to support the role of HPP1 as a tumor suppressor gene. Moreover, activation of the STAT1 pathway likely represents the principal mediator of HPP1's tumor suppressive properties. © 2007 Wiley‐Liss, Inc.
SPARC modulates the proliferation of stromal but not melanoma cells unless endogenous SPARC expression is downregulated
Authors: Haber Cynthia López , Gottifredi Vanesa , Llera Andrea S. , Salvatierra Edgardo , Prada Federico , Alonso Leonardo , E. Helene Sage , Podhajcer Osvaldo L.
Published: December 2007

Cell interaction with the extracellular matrix (ECM) has profound influence in cancer progression. The secreted protein, acidic and rich in cysteine (SPARC) a component of the ECM, impairs the proliferation of different cell types and modulates tumor cell aggressive features. This apparent paradox might result either from the biochemical properties of the different SPARC sources or from differential responses of malignant and stromal cells to SPARC. To test these hypotheses, we purified SPARC secreted by melanoma cells (hMel‐SPARC) and compared its activity with different recombinant SPARC preparations, including a new one produced in insect cells. All 5 SPARC species were effective in inhibiting bovine aortic endothelial cell proliferation, adhesion and migration. We then used the melanoma‐derived protein to assess SPARC effect on additional cell types. hMel‐SPARC greatly impaired the proliferation of both normal and transformed human endothelial cells and exerted a moderate biphasic effect on human fetal fibroblasts proliferation, irrespective of their endogenous SPARC levels. However, SPARC had no effect on the proliferation of several human cancer cell lines regardless of their endogenous levels of SPARC expression. Importantly, downregulation of SPARC levels in melanoma cells using either an antisense RNA or a shRNA against SPARC sensitized them to hMel‐SPARC addition in proliferation and migration assays, suggesting that malignant cells developed a SPARC‐resistance mechanism. This was not a general resistance to growth suppressing agents, as melanoma cells with restricted SPARC expression were more resistant to chemotherapeutic agents. Thus, malignant cells expressing or not expressing SPARC developed alternative mechanisms that, in contrary to stromal cells, rendered them SPARC‐insensitive. © 2007 Wiley‐Liss, Inc.