bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges in Drilling in Campos Basin
Authors: Paes P. , Ajikobi F. , Chen D. C. -K.
Published: January 2008

Brazil's Campos Basin, home of several fields in water depth ranging from 100 m to more than 2000 m, is one of the most important deepwater developments in the world. Campos Basin also accounts for nearly 80 percent of Brazil's overall crude output. Drilling in Campos Basin, however, has been quite challenging due to difficult pore pressure prediction and close margin between pore pressure and fracture gradient. In addition, poor hole cleaning and high drilling vibrations have also resulted in substantial non-productive time (NPT) and related costs. To improve drilling performance, Petrobras has employed a new drilling optimization operation focused on optimization specialists with state-of-the-art technologies such as real-time modeling and LWD/MWD tools. Over the past three years, over sixty drilling optimization operations were completed in the Campos Basin area. Those fit-for-purpose optimization operations have substantially reduced the drilling cost, reduced NPT, and increased drilling efficiency. This paper will discuss the drilling problems and the technologies used to solve these problems.
Waste Management Strategy Decision Matrix is Crucial to Compliant and Economical Waste Treatment and Disposal
Authors: Collins R. , Stanley A.
Published: January 2008

To help assure the successful development and implementation of the most appropriate waste management strategy, should be thoroughly considered all variables which may affect the operation. These factors may come from any number of areas, including but not limited to operations, logistics, regulatory policies, internal company strategy or equipment availability. As the cost for waste management approaches and surpasses the cost of the actual fluid services, the importance of the development of the proper response to the challenge only increases.

An environmental management strategy should address every portion of the fluid systems. Drilling fluid, completion fluid, production fluid, stimulation fluid and cement slurries can all have different residual effects which must be considered. Coupled with generated solids such as drilled cuttings and produced sands, the task of deciding on the correct disposal option becomes critical. By understanding the factors that effect each individual operation and area and utilizing correct management practices and procedures, a purpose-designed, compliant option should be identified and implemented. This strategy, backed with proper monitoring and documentation, can provide the operator with a sustainable environmentally responsible and compliant solution.

Environmental legislation varies from country to country, and even specific region to region within a country, and the legislation may be subject to frequent changes. Another critical component is the operator's own corporate standards. These can often be more stringent than regulatory limits, which can help prevent future liability for actions taken today. Therefore, proper comprehension of all applicable legislation and the operator's internal standards is critical. The costs, both direct and in-direct, of non-compliance should be considered.

The minimization and control of waste which develops from the strategy can also have the beneficial effect of reducing the number of health-related issues by minimizing or mitigating effluent discharge through air, water and soil releases. The benefits realized through proper handling and disposal of waste materials can have a correlation with reduction of occupational hazards.
Deepwater Horizontal Openhole Gravel Packing in Marlim Sul Field, Campos Basin, Brazil—Completion Project Learning Curve and Optimization
Authors: Acosta Marco , Farias Rodrigo , Vilela Álvaro , Mendez Alfredo , Pineda Francisco , Montanha Roberto , Garcia Eduardo , Calderon Agostinho , Magno Carlos , Germino Mário
Published: January 2008

Most of the deepwater Campos Basin reservoirs, offshore Brazil, have unconsolidated formations that require sand control. Openhole gravel packing has proven to be the effective completion method of choice. The main objectives were to achieve low damage ratios, maximize completion efficiencies and reduce completion time.

The project was conducted in one of the largest deepwater offshore fields in Brazil, Marlim Sul. This paper describes the learning curve and completion optimization obtained during planning, execution, and post-job analysis of six horizontal wells campaign with five water injectors and one oil producer.

A combination of integrated service lines and experienced personnel were important to achieve excellent injectivity and productivity ratios. Several key operations from drilling to completion contributed to successfully complete these wells: openhole stability, drilling practices, drill-in fluids (DIFs), wellbore clean-up, filtration, completion fluids, completion tools, sand control, gravel-pack software simulator, and job execution.

The efficiency of the service company was measured with a system of penalties and rewards allowing the operator to monitor and measure the progress of the learning curve on completion. As a final result, the partnership between the operator and the service companies contributed to a more economic completion cost by reducing completion time, and improving well performance.
Treatment of SAGD Produced Waters Without Lime Softening
Authors: Bridle M.
Published: January 2008

The produced waters from Steam Assisted Gravity Drainage (SAGD) facilities are characterized by low concentrations of both total hardness (TH) and total dissolved solids (TDS) and high silica concentrations. Treatment of these waters to provide feed-water suitable for Once Through Steam Generators (OTSG) has traditionally included either hot or warm lime softeners (HLS/WLS) and ion exchange. The primary function of the lime softening process is for silica removal.

A proposed alternate process that utilizes ion exchange only and depends on the premise that provided the divalent and trivalent cations are reduced to the parts per billion (ppb) level, will allow the OTSG to operate at high silica concentrations. This process eliminates the need for a lime softening stage and savings in capital and operating costs are realized.
Steam-Fingering Phenomenon During SAGD Process
Authors: Ito Y. , Ipek G.
Published: January 2008

A steam chamber generally rises steadily in the channel sands of Athabasca oil sands during a SAGD operation. It is commonly known that steam chamber growth rate is mainly dependent to permeability. Once the steam chamber reaches the upper boundary, it starts to expand laterally. This is the basic concept of steam chamber growth of SAGD process in fine sands.

However, the growth of steam chamber measured through the analysis of temperature changes from observation wells behaves different in many instances than the commonly accepted steam chamber growth concept, explained above. In these observation wells, the steam chamber deviates from the usual behavior; sometimes stops and then resumes rising or shrinking, or even disappears during SAGD process. This can be caused by the specific nature of steam fingering phenomenon during SAGD operation.

Many simulation studies have been conducted to understand the steam rising phenomenon during SAGD operations. At the top of the steam chamber, steam fingers seemed to be created where steam flows through and the steam chamber expands vertically. If steam fingering actively develops, steam chamber grows steadily as expected. However, activity of fingering can be disturbed under certain conditions, which can result in various alterations in the growth of steam chamber.

In this paper, the steam fingering phenomenon during SAGD process is discussed with actual measured field data from four SAGD projects; UTF Phase A, UTF Phase B, Hangingstone and Surmount.
Numerical Studies of Gas Exsolution in a Live Heavy-Oil Reservoir
Authors: Uddin M.
Published: January 2008

Gas phase formation in supersaturated live heavy oil occurs by bubble nucleation and growth. Modeling the dynamics of these processes in cold production is essential, since they are key mechanisms in determining oil recovery. The greatest challenge in field scale simulations of cold production is to quantify the spatial and temporal changes of the gas exsolution and transport processes.

This paper describes a new kinetic model which, when coupled with a thermal reservoir simulator, can simulate the dynamics of gas exsolution and transport processes in a heavy oil reservoir. In this model, two relatively simple types of mass transfer equations predict bubble nucleation and growth in a live heavy reservoir. The model structure and parameters were investigated in comparison with a previously published model.

The capability of the proposed kinetic model to handle the dynamics of gas phase formation in a heavy oil reservoir was explored in two sets of laboratory experimental data. In set 1, numerical history matches of pressure data were performed for eight constant withdrawal rate experiments. In set 2, numerical history matches of oil and gas production data were performed for four pressure depletion experiments. A close agreement was achieved between numerical simulation and experimental results. The model can be applied in the field scale simulations of cold production to predict gas exsolution and gas builds up in an oil reservoir.
An Overview of Iterative Coupling Between Geomechanical Deformation and Reservoir Flow
Authors: Tran D. , Nghiem L. , Buchanan L.
Published: January 2008

Recently, there is a strong interest in the modelling of reservoir fluid flow with geomechanical deformation. With the help of geomechanics, many physical phenomena can be explained, e.g. reservoir compaction and subsidence, casing failure or pore collapse. Several methods for coupling geomechanics to fluid flow in the reservoir have been proposed: fully coupled, iterative coupled and explicit coupled methods. The iterative coupled method has proven to be the most effective approach. However, no paper has discussed this method in detail from a reservoir engineering perspective. In this paper, the iterative coupling method is described step by step from the basic equations for geomechanics and reservoir flow to the coupling technique through porosity and permeability. This description is aimed at reservoir engineers with little background in geomechanics. A number of examples using different nonlinear constitutive models such as elasto-plasticity model, elastoplastic cap model and dilation-recompaction model are used to illustrate the importance of including geomechanics in reservoir simulation.
A Parametric Study of the Effects of Reservoir and Operational Properties on the Performance of Steam Displacement of Heavy Oil in Naturally Fractured Reservoirs
Authors: Cicek O.
Published: January 2008

This research effort discusses the effects of a comprehensive range of fluid, rock-fluid and operational properties on the efficiency of steam injection in naturally fractured reservoirs with heavy oil. For this purpose, a fully implicit dual-porosity/dual-permeability simulator is developed, and the model is applied to an inverted nine-spot pattern in a naturally fractured reservoir with heavy oil. The effects of the reservoir and operational properties on the steam displacement of heavy oil are studied comparatively in naturally fractured reservoirs with and without interacting matrix blocks and in approximate single porosity realizations of these naturally fractured reservoirs.

The field scale numerical model is three-dimensional and three phase accounting for capillary, gravitational and viscous forces. The model solves for (nHC+5) primary variables simultaneously, where nHC is the number of hydrocarbon components. The fully implicit model formulates all reservoir and operational parameters as functions of all the primary variables. The model is linearized using the Newton-Raphson method. A direct and an iterative solver is used in the solution of the system of linear equations.

The simulations of steam injection in naturally fractured systems are carried out for long periods of time in order to test the features of the model under strained conditions. The model is verified against the Fourth and Sixth SPE Comparative Solution Projects.

This study should help in screening naturally fractured reservoirs for steam injection, and in designing steam injection operations in these reservoirs. The comparative analysis of the effects of reservoir and the operational parameters in naturally fractured reservoirs should provide insight into the range of confidence of heavy oil recovery from naturally fractured reservoirs by steam injection.
Assessment and Development of Heavy-Oil Viscosity Correlations
Authors: Hossain M. S. , Sarica C. , Zhang H.-Q. , Rhyne L. , Greenhill K. L.
Published: January 2008

Heavy oil always poses a great challenge to production and transportation systems due to its high viscosity. This paper evaluates fourteen dead, eight saturated and nine under saturated live oil viscosity correlations against a databank consisting of heavy oil data from various parts of the world with wide ranges of temperature, pressure and fluid compositions. The existing empirical viscosity correlations were mostly developed for significantly lighter oils. Most of them cannot reasonably predict the heavy oil viscosity at low temperatures. Three new empirical correlations for dead, saturated and under saturated oils are developed that are applicable for the heavy oils with API gravity ranging from 10 to 22.3. When compared with the databanks, the new dead oil, saturated and under saturated oil viscosity correlations showed 3 to 50%, 3 to 13% and 22 to 27% improvement over the existing best correlations, respectively. Saturated, Aromatics, Resin and Asphaltenes (SARA) data of some heavy oils were also analyzed to understand the role of the asphaltene and resins in heavy oil viscosity.
Improving the Performance of SAGD
Authors: Das S.
Published: January 2008

In the recent years several SAGD projects have been initiated for the recovery of heavy oil and bitumen. Every operator is coming across new learning almost every day, although most of this information is proprietary. This paper presents a general discussion, supported by simulation and analytical results, on the different aspects of improving the performance of SAGD operations. The first component is the well bore design, which has to match with the gravity drainage rate. Operating pressure plays a significant role in the rate of recovery. Lower operating pressure reduces the SOR, lower H2S production, may reduce the silica dissolution, thereby, reduce the water treatment issues. However, low pressure operation increases the challenges of lifting the fluid to the surface. Steam additives may be the other option to increase the energy efficiency of the process.
Type Curves for Production Prediction and Evaluation of Coalbed Methane Reservoirs
Authors: Aminian K. , Ameri S. , Bhavsar A. B. , Lakshminarayanan S.
Published: January 2008

Prediction and analysis of the coalbed methane (CBM) production is challenging especially at the early stages of the recovery when production is subject to two-phase flow conditions. CBM reservoirs are dual-porosity systems that are characterized by a complex interaction of coal matrix and cleat system that are coupled through desorption process. As a result, the conventional methods cannot be utilized to predict CBM production. Currently, only numerical models (simulators) can be used to predict (CBM) production behavior since they incorporate the unique flow and storage characteristics of CBM reservoirs. Often, the number of variables needed for evaluation of a given prospect is greater than that typically measured. In such cases, parametric studies are conducted to evaluate the impacts of reservoir properties on recovery factor, well performance, and future revenues. However, parametric studies with a reservoir simulator is cumbersome, time consuming and expensive. Therefore, there is a need for scientific, user-friendly tools that can assist the typical gas producers in evaluation of CBM prospects.

This study presents a set of production type curves for CBM reservoirs. A reservoir model that incorporates the unique flow and storage characteristics of CBM reservoirs was employed to generate the type curves. Our previous study (SPE 91482) introduced a new set of dimensionless groups that led to development of unique set of type curves. The impact of basic reservoir characteristics was also investigated to confirm the uniqueness of the type curves. This study investigates the impact of key parameters including isotherm constants and relative permeability data on the type curves. The type curves can be used to predict and/or analyze gas and water the production from CBM wells both during de-watering and stable gas production phases. The issues concerning the application and limitation of the type curves are also presented. Finally, a type curves-based simple yet reliable tool with graphical user interface (GUI) was developed. This tool can be used for predicting and analyzing production performance of CBM reservoirs with simple and straight forward input requirements. This tool is particularly useful for parametric studies to evaluate CBM prospects.
Post-Fracture Performance Diagnostics for Gas Wells with Finite-Conductivity Vertical Fractures
Authors: Rushing J. A. , Sullivan R. B. , Blasingame T. A.
Published: January 2008

This paper presents an integrated technique for evaluating the production performance of gas wells with finite-conductivity vertical fractures. Our methodology combines conventional pressure transient test analysis with new material balance decline type curves developed specifically for gas wells with finite-conductivity, vertical fractures. We utilize short-term pressure buildup test analysis to enhance the production data analysis, particularly for interpretation of early-time transient flow behavior. We illustrate—with several field cases—that both techniques can be integrated to provide not only a more consistent and systematic analysis methodology, but also a more accurate assessment of stimulation effectiveness.
Impact of Viscous Fingering on the Prediction of Optimum WAG Ratio
Authors: Juanes Ruben , Blunt Martin J.
Published: January 2008

In miscible flooding, injection of solvent is often combined with water to reduce the mobility contrast between injected and displaced fluids and control the degree of fingering. Using traditional fractional-flow theory, Stalkup estimated the optimum watersolvent ratio (or WAG ratio) when viscous fingering effects are ignored, by imposing that the solvent and water fronts travel at the same speed. Here we study how the displacement efficiency and the mobility ratio across the solvent front vary with the WAG ratio when fingering is included in the analysis. We do so by computing analytical solutions to a 1D model of two-phase, three-component, first-contact miscible flow that includes the macroscopic effects of viscous fingering. The macroscopic model, originally proposed by Blunt and Christie (1993, 1994), employs an extension of the Koval fingering model to multiphase flows. The premise is that the only parameter of the model—the effective mobility ratio—must be calibrated dynamically until self-consistency is achieved between the input value and the mobility contrast across the solvent front. This model has been extensively validated by means of high-resolution simulations that capture the details of viscous fingering and carefully-designed laboratory experiments.

The results of this paper suggest that, while the prediction of the optimum WAG ratio does not change dramatically by incorporating the effects of viscous fingering, it is beneficial to inject more solvent than estimated by Stalkup's method. We show that, in this case, both the pore volumes injected (PVI) for complete oil recovery and the degree of fingering are minimized.
On the Computation of the GCD of 2-D Polynomials
Authors: Tzekis Panagiotis , Karampetakis Nicholas , Terzidis Haralambos
Published: January 2008

On the Computation of the GCD of 2-D Polynomials

The main contribution of this work is to provide an algorithm for the computation of the GCD of 2-D polynomials, based on DFT techniques. The whole theory is implemented via illustrative examples.
Reduction in the Number of PAL Macrocells in the Circuit of a Moore FSM
Authors: Barkalov Alexander , Titarenko Larysa , Chmielewski Sławomir
Published: January 2008

Reduction in the Number of PAL Macrocells in the Circuit of a Moore FSM

Optimization methods of logic circuits for Moore finite-state machines are proposed. These methods are based on the existence of pseudoequivalent states of a Moore finite-state machine, a wide fan-in of PAL macrocells and free resources of embedded memory blocks. The methods are oriented to hypothetical VLSI microcircuits based on the CPLD technology and containing PAL macrocells and embedded memory blocks. The conditions of effective application of each proposed method are shown. An algorithm to choose the best model of a finite-state machine for given conditions is proposed. Examples of proposed methods application are given. The effectiveness of the proposed methods is also investigated.
Why Was Louis Riel, a United States Citizen, Hanged as a Canadian Traitor in 1885?
Authors: Mumford Jeremy Ravi
Published: January 2008

In what sense was Louis Riel, a foreign citizen who had formally renounced his allegiance to Britain, a traitor to the Queen? And why did his adopted country, the United States, do nothing to protect him? Since the Canadian Naturalization Act of 1881 for the first time permitted emigrants to renounce their British allegiance, Riel's legal status was no different from that of any foreigner, and to charge a foreigner with treason was unusual and controversial. The United States, furthermore, had a history of advocating aggressively for citizens charges with crimes abroad, even when they were clearly guilty, and especially for political militants in Britain and Canada. Yet for a number of independent reasons, including decisions of courtroom strategy and the internal politics of the United States in 1885, Riel's lawyers and his adopted government chose not to raise his citizenship as an issue. The surprising silence about his US citizenship at the end of his life has distorted our historical understanding of Riel as a figure of the nineteenth-century Canadian-American borderland.
Mike Pearson at Oxford: War, Varsity, and Canadianism
Authors: Champion C.P.
Published: January 2008

The connection between Oxford University and Canadian nationalism is often cited but has been little explored. Oxford appears to have been something of an epiphany, a rite of passage from which the Canadians returned confident of their equality and distinctiveness, determined to be colonial no longer. It was, after all, a circle of Oxford alumni who presided over so great a symbol of independent nationhood as Lester Pearson's Maple Leaf flag of 1965, based on a design submitted by George Stanley. Still, if Pearson and his contemporaries gained a new consciousness of themselves as Canadians, it tends to be overlooked that Oxford reinforced their Britishness as well as their Canadianism. The flag was fundamentally an expression of British-Canadianism that can be traced, in part, to Oxford where Pearson and Stanley earned their ‘blue’ playing hockey. It was a fulfilment, rather than a rejection, of British liberal imperialism. The ‘Res Canadiana’ (as distinct from the Res Britannica) was the product of a British world, and post-1965 Canadianism cannot be understood without reclaiming and deciphering the Britishness underneath.
An Empire on Paper: The Founding of Halifax and Conceptions of Imperial Space, 1744–55
Authors: Lennox Jeffers
Published: January 2008

The founding of Halifax in 1749 was a watershed in British imperial policy. The settlement was state-funded and served political, not commercial, aims. Mapping – the creation and representation of geographic knowledge – was essential to Halifax's success because it shaped Britain's relationship to the land and subsequently influenced how Britons in the settlement interacted with each other and with resistant groups. Cartographic knowledge was never static, but instead was affected by cultural, political, and economic realities that directed the work of local commissioned surveyors like Charles Morris, and metropolitan public mapmakers like Thomas Jefferys. From 1744 to 1755, geographic imaginings of Halifax changed to address specific imperial goals: first, reconnaissance maps and surveys delimited boundaries and provided data; second, early settlement geographic knowledge established Britain's claim to the Halifax region by controlling the Native presence and emphasizing British strength; and third, ‘popular’ cartography rallied support for the empire by promoting attractive imperial images among Britons. Geographic knowledge produced from the Halifax settlement indicates that spatial information was Janus-faced: maps and reports negotiated a fine line between value-free geographic information and imperially favourable geographic imaginations. In each case mapping and its cartographic evidence were key independent variables in the socio-political organization of power that situated early modern Canada in a British Atlantic world.
The Canadian Hockey Player Problem: Cultural Reckoning and National Identities in American Collegiate Sport, 1947–80
Authors: Holman Andrew C.
Published: January 2008

This article is a study in the social history of Canadian-American relations and it performs two functions. First, it traces the increasing presence of Canadian student athletes in American collegiate hockey, 1947–80, and the efforts of coaches, recruiters, administrators, and alumni to draw Canadians to US hockey programs. By the end of the 1950s Canadian student athletes dominated the American collegiate game – a pattern that abated only in the late 1970s. Second, this essay analyzes the heated debates that emerged in these years about the threats that these students posed to American collegiate athletics and to Canadian amateur hockey. The Canadianization of US college hockey from 1947 to 1980 was hardly universally welcomed in the United States or in Canada and it produced no small amount of rancour among American and Canadian commentators. Canadian hockey players in American schools personified the commercialization of amateur collegiate sport, according to some in the United States. In Canada, expatriate collegians were seen alternately as victims of American ‘talent raiders’ and disloyal to the communities that raised, invested in, and trained them. This essay demonstrates how hockey generated concerns about national identity in Canada and the United States in the sixties and seventies, and asserts, more generally, that the study of sport – hockey in particular – provides an important window on the historical and quotidian construction of national identities.
On the consideration of automatic as well as controlled psychological processes in aggression
Authors: Berkowitz Leonard
Published: January 2008

Without slighting the important role played by controlled psychological processes in human aggression, this paper recommends that considerable systematic attention should also be given to the operation of automatic processes in bringing about this behavior. The concepts of automaticity and impulsivity are discussed briefly and it is proposed that many impulsive actions, particularly antisocial ones, are due to failures of restraint after they were initiated involuntarily. A number of experiments are reviewed in which situational stimuli automatically instigated or heightened aggressive inclinations. These have to do with associations in hostility displacement, reactions to stigmatized persons, and association in aggressive reactions to media violence. The last‐mentioned studies deal especially with factors affecting the selection of the target for aggression. In discussing these findings it is suggested that after the crucial situational features had automatically initiated the sequence of determinants, the aggression displayed could have been due either to a hostile appraisal of the target or the activation of aggression‐related bodily reactions as well as hostile ideas. It is also hypothesized that in at least one of the studies, an experienced negative affect might have instigated the aggression independently of any appraisals. Aggr. Behav. 34:117–129, 2008. © 2008 Wiley‐Liss, Inc.
Synthesis of Fe‐MCM‐41 from silatrane and FeCl3 via sol–gel process and its epoxidation acivity
Authors: Thitsartarn W. , Gulari E. , Wongkasemjit S.
Published: January 2008

An iron‐containing mesoporous molecular sieve, or Fe‐MCM‐41, was successfully synthesized the via sol–gel technique using silatrane and FeCl3 as the silicon and iron sources, and was characterized using various techniques. Many factors were investigated, namely, reaction temperature and time, calcination rate, and iron amount in the reaction mixture. It was found that the optimum conditions in which to synthesize Fe‐MCM‐41 was to carry out the reaction at 60 °C for 7 h using a 1 °C min−1 calcination rate and a 550 °C calcination temperature. The catalytic activity and selectivity of styrene epoxidation using hydrogen peroxide showed that the selectivity of the styrene oxide reached 65% at a styrene conversion of 22% over the 1%wt catalyst. Copyright © 2008 John Wiley & Sons, Ltd.
A novel route to perovskite lead zirconate titanate from glycolate precursors via the sol–gel process
Authors: Tangboriboon N. , Jamieson A. , Sirivat A. , Wongkasemjit S.
Published: January 2008

A perovskite lead zirconate titanate was synthesized by the sol‐gel process, using lead glycolate, sodium tris(glycozirconate) and titanium glycolate as the starting precursors. For the mole ratio Pb:Zr:Ti of 1:0.5:0.5 [Pb(Zr0.5Ti0.5)O3], TGA‐DSC thermal analysis indicated that the percentage of ceramic yield was 55.8, close to the calculated chemical composition value of 49.5. The exothermic peak occurred at 268 °C below the theoretical Curie temperature of 400 °C. The pyrolysis of Pb(Zr0.5Ti0.5)O3 of the perovskite phase was investigated in terms of calcination temperature and time. The structure obtained was of the tetragonal form when calcined at temperatures below 400 °C; it transformed to the tetragonal and the cubic forms of the perovskite phase on calcination above the Curie temperature, as verified by X‐ray data. The lead zirconate titanate synthesized and calcined at 400 °C for 1 h had the highest dielectric constant, the highest electrical conductivity and the dielectric loss tangent of 10 190, 0.803 × 10−3 (Ω.m)−1 and 1.513 at 1000 Hz, respectively. The lead zirconate titanate powder synthesized has potential applications as an electronic material. Copyright © 2008 John Wiley & Sons, Ltd.
Use of special education services by children with orofacial clefts
Authors: Yazdy Mahsa M. , Autry Andrew R. , Honein Margaret A. , Frias Jaime L.
Published: January 2008

BACKGROUND:Our objective was to evaluate the use of special education services by children with orofacial clefts (OFCs).METHODS:We linked the birth certificates of children born from 1982–2001 in five counties of metropolitan Atlanta to a population‐based birth defects surveillance system to identify children with OFCs, and to the special education files for the school years 1992–2004 to identify children who used special education services. The special education data contained exceptionalities and services rendered for each school year. Prevalence ratios (PRs) and 95% CIs were calculated. The data were stratified by race/ethnicity, maternal education, type of OFC, and the presence of associated major malformations. In addition, we assessed the age at which special education began and the amount of time spent receiving services.RESULTS:Of the 777 children with OFCs, 201 (26%) were in special education at least 1 year compared with 8% of the children who had no major birth defects, yielding a PR of 3.2 (95% CI: 2.9–3.6). The most common exceptionality or service for children with an OFC was speech and language services. Compared with children with no birth defects, children with an OFC were four times more likely to be in this exceptionality (PR 3.8; 95% CI: 3.3–4.3). After excluding children in speech and language services, children with OFCs were still more likely to use special education services (PR 2.4; 95% CI: 1.7–3.2).CONCLUSIONS:Children with OFCs used special education services more often than children without birth defects. This information can help in planning for future population needs. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Design, structural, and immuno‐analytical properties of antigenic bioconjugates comprising a β‐amyloid‐plaque specific epitope
Authors: Manea Marilena , Przybylski Michael , Hudecz Ferenc , Mezö Gábor
Published: January 2008

Immunotherapeutic approaches are investigated for treatment of neurodegenerative diseases of the Alzheimer's dementia (AD) type. The identification of a β‐amyloid‐plaque specific epitope, Aβ(4‐10) (4FRHDSGY10), recognized by therapeutically active antibodies from transgenic AD mice could provide the basis for the development of AD vaccines. Here we report on the synthesis, structural and immuno‐analytical characterization of bioconjugates comprising the β‐amyloid(4‐10) epitope as new vaccine lead structures against Alzheimer's disease. To produce antigenic bioconjugates, potential immunogens, the epitope peptide elongated by a cysteine residue or a cysteinyl‐pentaglycine hexapeptide unit either at the N‐ or C‐terminus was attached via a thioether bond to synthetic oligopeptide carriers, such as oligotuftsin derivatives, sequential oligopeptide carrier, or lysine dendrimer. The antigenic properties of these constructs were determined by enzyme‐linked immunosorbent assay (ELISA) using an anti‐Aβ(1‐17) monoclonal antibody. Our results indicate that the major factors which influence the antibody binding of the Aβ(4‐10) epitope are (i) the epitope topology and (ii) the presence of a spacer moiety between the carrier and the epitope peptide. Interestingly, the carrier type had no marked effect on the binding of the antibody to the epitope‐conjugates. The conformational preferences of the conjugates were examined by circular dichroism spectroscopy in water and in trifluoroethanol. In water, the conjugates adopt random coil conformation independently on their primary structure. However, differences related to the attachment site of the epitope to the carriers were determined in TFE, conjugates in which the epitope was attached to the carrier through the N‐terminus exhibiting more ordered secondary structure. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 94–104, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Biophysical Properties of CDAN/DOPE‐Analogue Lipoplexes Account for Enhanced Gene Delivery
Authors: Fletcher Steven , Ahmad Ayesha , Price Wayne S. , Jorgensen Michael R. , Miller Andrew D.
Published: January 2008

Typically, cationic liposomes are formulated from the combination of a synthetic cationic lipid (cytofectin) and a neutral, biologically available co‐lipid. However, the use of cationic liposome formulations to mediate gene delivery to cells is hampered by a paradox. Cationic lipids, such as N1‐cholesteryloxycarbonyl‐3‐7‐diazanonane‐1,9‐diamine (CDAN), are needed to ensure the formation of cationic liposome‐DNA (lipoplex, LD) particles by plasmid DNA (pDNA) condensation, as well as for efficient cell binding of LD particles and intracellular trafficking of pDNA post‐intracellular delivery by endocytosis. However, the same cationic lipids can exhibit toxicity, and also promote LD particle colloidal instability, leading to aggregation. This results from electrostatic interactions with anionic agents in biological fluids, particularly in vivo. One of the most commonly used neutral, bioavailable co‐lipids, dioleoyl L‐α‐phosphatidylethanolamine (DOPE), has been incorporated into many cationic liposome formulations owing to its fusogenic characteristics that are associated with a preference for the inverted hexagonal (HII) phase—a phase typical of membrane–membrane fusion events. However, these same fusogenic characteristics also destabilize LD particles substantially with respect to aggregation, in vitro and especially in vivo. Therefore, there is a real need to engineer more stable cationic liposome systems with lower cellular toxicity. We hypothesize that one way to achieve this goal should be to find the means to reduce the mol fraction of cationic lipid in cationic liposomes without impairing the overall transfection efficiency, by replacing DOPE with an alternative co‐lipid with fusogenic properties “tuned” with a greater preference for the more stable lamellar phases than DOPE is able to achieve. Herein, we document the syntheses of triple bond variants of DOPE, and their formulation into a range of low charge, low cationic lipid containing LD systems. The first indications are that our hypothesis is correct in vitro.
A New Strategy for Designing Non‐C2‐Symmetric Monometallic Bifunctional Catalysts and Their Application in Enantioselective Cyanation of Aldehydes
Authors: Yang Fei , Wei Siping , Chen Chien‐An , Xi Peihua , Yang Li , Lan Jingbo , Gau Han‐Mou , You Jingsong
Published: January 2008

A monometallic bifunctional catalyst, in which only one imidazolyl moiety is directly attached at the 3‐position of a binaphthol moiety, has been developed. The ligand (R)‐1, which lacks C2‐symmetry and flexible linkers, in combination with Ti(OiPr)4, has been demonstrated to promote the enantioselective cyanation of aldehydes with trimethylsilylcyanide (TMSCN), giving excellent enantioselectivities of up to 98 % ee and high yields of up to 99 %. The use of this bifunctional catalytic system obviates the need for additives and is extremely simple as the reagents are added in one portion at the beginning of the reaction. The protocol has been found to tolerate a relatively wide range of aldehydes when 10 mol % of the (R)‐1/Ti(OiPr)4 complex is deployed in CH2Cl2 at −40 °C, the conditions which proved most practical and effective. The asymmetric cyanations also proceeded with lower catalyst loadings (5 mol %, or even 2 mol %), still giving satisfactory enantiomeric excesses and yields. Interestingly, the use of freshly distilled TMSCN dried over CaH2 gave a low enantioselectivity and only a moderate yield of the adduct as compared with direct use of the commercial reagent. The results of 13C NMR spectroscopic studies implicate HCN as the actual reactive nucleophile.
ChemInform Abstract: Four New Hydroxymonophosphates with Closely Related Intersecting Tunnels Structures: The Series AMIII(PO3(OH))2 with A: Rb, Cs; M: Fe, Al, Ga, In.
Authors: Lesage J. , Adam L. , Guesdon A. , Raveau B.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Structure of Ln1/3NbO3 (Ln: Nd, Pr) and Phase Transition in Nd1/3NbO3.
Authors: Zhang Zhaoming , Howard Christopher J. , Kennedy Brendan J. , Knight Kevin S. , Zhou Qingdi
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Novel Class of Aeschynite Structure LaNbTiO6‐Based Orange‐Red Phosphors via a Modified Combustion Approach.
Authors: Ma Qian , Zhang Aiyu , Lue Mengkai , Zhou Yuanyuan , Qiu Zifeng , Zhou Guangjun
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: NMR Structural Study on the As—P—S Glassy System.
Authors: Santagneli S. H. , Skripatchev I. , Ribeiro S. J. L. , Messaddeq Y. , Schneider J.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis, Crystal Structure and Thermoelectric Properties of a New Carbide Zr2[Al3.56Si0.44]C5.
Authors: Fukuda Koichiro , Hisamura Miyuki , Iwata Tomoyuki , Tera Nobuyuki , Sato Kimiyasu
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Comparison of the Spin Exchange Interactions in PbCu2(PO4)2 and SrCu2(PO4)2 on the Basis of Spin Dimer Analysis.
Authors: Koo Hyun‐Joo , Kang Myoung‐Hee
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: New Cathode Materials for Rechargeable Mg Batteries: Fast Mg Ion Transport and Reversible Copper Extrusion in CuyMo6S8 Compounds.
Authors: Mitelman A. , Levi M. D. , Lancry E. , Levi E. , Aurbach D.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Two‐Dimensional Layer Architecture Assembled by Keggin Polyoxotungstate, Cu(II)—EDTA Complex and Sodium Linker: Synthesis, Crystal Structures, and Magnetic Properties.
Authors: Liu Hong , Xu Lin , Gao Guang‐Gang , Li Feng‐Yan , Yang Yan‐Yan , Li Zhi‐Kui , Sun Yu
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Diol Desymmetrization as an Approach to the Synthesis of Unsymmetrical Dienyl Diesters.
Authors: Phillips David J. , Pillinger Kathryn S. , Li Wei , Taylor Angela E. , Graham Andrew E.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Facile and Chemo‐Selective Synthesis of Tertiary Alkyl Isothiocyanates from Alcohols.
Authors: Miyake Hideyoshi , Nakao Yuichi , Sasaki Mitsuru
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Microwave‐Accelerated Claisen Rearrangement in Bicyclic Imidazolium [b‐3C‐im][NTf2] Ionic Liquid.
Authors: Lin Yung‐Lun , Cheng Jen‐Yen , Chu Yen‐Ho
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Enantioselective Cyanoformylation of Aldehydes Catalyzed by a Chiral Quaternary Ammonium Salt and Triethylamine.
Authors: Peng Dan , Zhou Hui , Liu Xiaohua , Wang Liwei , Chen Shikui , Feng Xiaoming
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Environmentally Benign Oxidation of Some Organic Sulfides with 34% Hydrogen Peroxide Catalyzed by Simple Heteropolyoxometalates.
Authors: Tayebee Reza , Alizadeh Mohammad Hassan
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Suzuki—Miyaura Cross‐Coupling of Arenediazonium Salts with Arylboronic Acids Catalyzed by a Recyclable Polymer‐Supported N‐Heterocyclic Carbene—Palladium Catalyst.
Authors: Qin Yuancheng , Wei Wei , Luo Meiming
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Simple Method for the Synthesis of Esters of 2‐Hydroxy‐3‐oxo‐2,3‐dihydrofuran‐2‐ylacetic Acid.
Authors: Kozminykh E. N. , Goncharov V. I. , Oborin D. B. , Kozminykh V. O.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Enantiomerically Pure Synthesis of β‐Substituted γ‐Butyrolactones: A Key Intermediate to Concise Synthesis of Pregabalin.
Authors: Ok Taedong , Jeon Aram , Lee Joohee , Lim Jung Hak , Hong Chang Seop , Lee Hee‐Seung
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: An Efficient Furan Synthesis Using Heterogeneous Catalysis.
Authors: Hayes Simon J. , Knight David W. , Menzies Melanie D. , O'Halloran Mark , Tan Wen‐Fei
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.