bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significant Decrease in Nelfinavir Systemic Exposure After Omeprazole Coadministration in Healthy Subjects
Authors: Fang Annie F. , Damle Bharat D. , LaBadie Robert R. , Crownover Penelope H. , Hewlett Dial , Glue Paul W. 
Published: December 2007

Study Objectives.To assess the effect of omeprazole on the multiple‐dose (steady‐state) pharmacokinetics and safety of nelfinavir, and to evaluate the safety and tolerability of nelfinavir when administered alone and with omeprazole.Design.Open‐label, two‐period, single‐fixed‐sequence study.Setting.Clinical research unit of a large, teaching hospital.Participants.Twenty healthy volunteers (mean age 26 ± 9 yrs, range 18–48 yrs).Intervention.Subjects received nelfinavir 1250 mg every 12 hours for 4 days (period 1). After a 7‐day washout period, subjects were coadministered nelfinavir 1250 mg every 12 hours and omeprazole 40 mg every 24 hours for 4 days (period 2).Measurements and Main Results.The pharmacokinetics of nelfinavir and its active metabolite M8 were determined on day 4 of both periods. Plasma samples were assayed by a high‐performance liquid chromatography‐ultraviolet method for nelfinavir and M8 concentrations, and noncompartmental pharmacokinetic analysis was performed by using analytical software. In the presence of omeprazole, nelfinavir area under the concentration‐time curve over the dosing interval (AUCẗ), maximum observed plasma concentration (Cmax), and minimum observed plasma concentration (Cmin) were reduced by an average of 36%, 37%, and 39%, respectively, relative to administration of nelfinavir alone. The AUCẗ, Cmax, and Cminof M8 were reduced by an average of 92%, 89%, and 75%, respectively. The slopes of the terminal elimination phase of nelfinavir and M8 plasma concentration‐time curves were similar between treatments. Nelfinavir was well tolerated when administered alone and when coadministered with omeprazole.Conclusion.The observed reduction in the systemic exposure to both nelfinavir and its active metabolite M8 after coadministration with omeprazole could result in loss of virologic control and potential emergence of drug resistance. Hence, omeprazole should not be coadministered to patients taking nelfinavir.
Insulin Redirects Differentiation from Cardiogenic Mesoderm and Endoderm to Neuroectoderm in Differentiating Human Embryonic Stem Cells
Authors: Freund Christian , Ward-van Oostwaard Dorien , Monshouwer-Kloots Jantine , van den Brink Stieneke , van Rooijen Marga , Xu Xiuqin , Zweigerdt Robert , Mummery Christine , Passier Robert 
Published: December 2007

Abstract
Human embryonic stem cells (hESC) can proliferate indefinitely while retaining the capacity to form derivatives of all three germ layers. We have reported previously that hESC differentiate into cardiomyocytes when cocultured with a visceral endoderm-like cell line (END-2). Insulin/insulin-like growth factors and their intracellular downstream target protein kinase Akt are known to protect many cell types from apoptosis and to promote proliferation, including hESC-derived cardiomyocytes. Here, we show that in the absence of insulin, a threefold increase in the number of beating areas was observed in hESC/END-2 coculture. In agreement, the addition of insulin strongly inhibited cardiac differentiation, as evidenced by a significant reduction in beating areas, as well as in α-actinin and β-myosin heavy chain (β-MHC)-expressing cells. Real-time reverse transcription-polymerase chain reaction and Western blot analysis showed that insulin inhibited cardiomyogenesis in the early phase of coculture by suppressing the expression of endoderm (Foxa2, GATA-6), mesoderm (brachyury T), and cardiac mesoderm (Nkx2.5, GATA-4). In contrast to previous reports, insulin was not sufficient to maintain hESC in an undifferentiated state, since expression of the pluripotency markers Oct3/4 and nanog declined independently of the presence of insulin during coculture. Instead, insulin promoted the expression of neuroectodermal markers. Since insulin triggered sustained phosphorylation of Akt in hESC, we analyzed the effect of an Akt inhibitor during coculture. Indeed, the inhibition of Akt or insulin-like growth factor-1 receptor reversed the insulin-dependent effects. We conclude that in hESC/END-2 cocultures, insulin does not prevent differentiation but favors the neuroectodermal lineage at the expense of mesendodermal lineages.
Disclosure of potential conflicts of interest is found at the end of this article.
High-Glucose-Induced Prostaglandin E2 and Peroxisome Proliferator-Activated Receptor δ Promote Mouse Embryonic Stem Cell Proliferation
Authors: Kim Yun Hee , Han Ho Jae 
Published: December 2007

Abstract
Peroxisome proliferator-activated receptor is a nuclear receptor that has been implicated in blastocyst implantation, cell cycle, and pathogenesis of diabetes. However, the signal cascades underlying this effect are largely unknown in embryo stem cells. This study examined whether or not there is an association between the reactive oxygen species-mediated prostaglandin E2 (PGE2)/peroxisome proliferator-activated receptor (PPAR) δ and the growth response to high glucose levels in mouse ESCs. A high concentration of glucose (25 mM) significantly increased the level of [3H]thymidine incorporation, the level of 5-bromo-2′-deoxyuridine incorporation, and the number of cells. Moreover, 25 mM glucose increased the intracellular reactive oxygen species, phosphorylation of the cytosolic phospholipase A2 (cPLA2), and the release of [3H]arachidonic acid ([3H]AA). In addition, 25 mM glucose also increased the level of cyclooxygenase-2 (COX-2) protein expression, which stimulated the synthesis of PGE2. Subsequently, high glucose-induced PGE2 stimulated PPARδ expression directly or through Akt phosphorylation indirectly through the E type prostaglandin receptor receptors. The PPARδ antagonist inhibited the 25 mM glucose-induced DNA synthesis. Moreover, transfection with a pool of PPARδ-specific small interfering RNA inhibited the 25 mM glucose-induced DNA synthesis and G1/S phase progression. Twenty-five millimolar glucose also increased the level of the cell cycle regulatory proteins (cyclin E/cyclin-dependent kinase [CDK] 2 and cyclin D1/CDK 4) and decreased p21WAF1/Cip1 and p27Kip1, which were blocked by the inhibition of the cPLA2, COX-2, or PPARδ pathways. In conclusion, high glucose promotes mouse ESC growth in part through the cPLA2-mediated PGE2 synthesis and in part through PPARδ pathways.
Disclosure of potential conflicts of interest is found at the end of this article.
Making Our Mature Fields Smarter—An Industrywide Position Paper from the 2005 SPE Forum
Authors: Murray R. , Edwards C. , Gibbons K. , Jakeman S. , de Jonge G. , Kimminau S. , Ormerod L. , Roy C. , Vachon G. 
Published: December 2007

Abstract
This paper summarizes the findings of the SPE Forum held in September 2005 on "Making our Mature Fields Smarter". Participants in the Forum have granted permission to present this paper on the basis that the authors are neither representing the views of the SPE nor of the participants’ companies.
We are delivering smarter fields in order to add value to our business - there are many facets to this value beyond reservoir, well, process and production management. What may not be so clear is how to apply these smart technologies to mature fields with a legacy infrastructure and long production history. Participants felt that maturity in itself made a challenge for deployment and enforces the need for effective Change Management. Deployment and Change Management are seen as the major challenges facing the creation of Smart Fields.
During the Forum it became apparent that companies do not have a common vision of what a truly Smart Field will look like and this contributes to the difficulty of assigning a value to "Smartness". There is a tendency to assign value to discrete technologies as opposed to the holistic full project value associated with the business process that has been improved by the application of that technology.
The essential foundations for a Smart Field are: People and Skills, effective Data Management and Industry Wide Standards, appropriate Hardware and Systems Architecture. High quality data is a fundamental building block of Smart Fields and it needs to be treated as an asset, managed effectively with staff assigned to ensure the integrity of the data management systems.
The key processes are built on this foundation and deliver the business result. These processes are supported by detailed workflows with corresponding enabling technologies. The business processes and workflows required to manage a mature field appear to be similar for many operators. The majority of the technologies that we require to create Smart Fields are already in place although we did identify seven specific areas where technology advances are recommended.
Collaboration and visualization technologies are enablers and are required in order to integrate across the core business processes and permit people working with these processes to assimilate the huge and diverse volumes of data and information.
Mechanistic Understanding of Microbial Plugging for Improved Sweep Efficiency
Authors: Gandler G. L. , Gbosi A. , Bryant S. L. , Britton L. N. 
Published: December 2007

Abstract
Microbial plugging has been proposed as an effective low cost method of permeability reduction. To optimize the field implementation, better mechanistic and volumetric understanding of biofilm growth within a porous medium is needed. In particular, the engineering design hinges upon a quantitative relationship between amount of nutrient consumption, amount of growth, and degree of permeability reduction. As a first step toward such a relationship, a Pseudomonas aeruginosa culture was inoculated into columns of glass beads and Berea sandstone cores. A growth substrate with acetate as carbon and energy source was injected continuously. Growth substrate utilization and permeability changes were used to track growth, and post-experiment in situ staining of biomass provided visual evidence of colonization and growth. Growth was observed as grainy coatings but in a spatially complex and unpredictable manner. Permeability was reduced noticeably in each experiment, but replicate experiments exhibited different growth rates and ultimate growth-induced permeability reduction. The experiments demonstrated that microbial growth is effective for reducing flow in porous media. Obtaining a mechanistic interpretation of the behavior will require a better understanding of the variability in microbe growth at the grain scale.
Detection of Water or Gas Entries in Horizontal Wells From Temperature Profiles
Authors: Dawkrajai P. , Lake L. W. , Yoshioka K. , Zhu D. , Hill A. D. 
Published: December 2007

Abstract
The temperature profiles in a horizontal oil-producing well can be measured precisely with distributed temperature sensors, which are being increasingly installed in intelligent well completions. With temperature resolution on the order of 0.1 °F, modern temperature-measuring instruments can detect small temperature changes along the wellbore that can indicate the locations of water or gas entries into an oil well. These temperature changes are primarily caused by differences in Joule-Thomson effects for each phase (oil, water, and gas) caused by the pressure drop in the well.
In this paper, we illustrate a specific condition for which water entry locations can be identified from the temperature profile of a horizontal well. The criterion for such discrimination is that a measurable change in the slope of the temperature profile occurs at the water entry location. Using a numerical model of temperature and pressure in the reservoir and the wellbore, we calculate time-varying temperature profiles for a bottom water drive reservoir. In these calculations, one section of the well was experiencing a large flow rate, while the rest of the open section of the well produced oil at a smaller rate. We varied the production rate and types of oil to see their effects on the temperature profiles.
From these sensitivity studies, we identified the relative water production rates that create identifiable temperature anomalies in the temperature profile along a horizontal well. The results confirm the utility of temperature profiles in identifying water or gas entries if the well rate is large.
Fatigue Integrity Analysis of Rotating Coiled Tubing
Authors: Tipton S. M. , Carlson G. H. , Sorem J. R. 
Published: December 2007

Abstract
Conventional coiled tubing endures severe above-ground bending and straightening cycles that cause low-cycle fatigue to be the predominant factor limiting its useful life. For conventional coiled tubing, downhole bending events associated with wellpath curvature are negligible since the strains generated are orders of magnitude less severe than strains casued by above-ground cyclic bending, and are applied with a very low cycle count.
A new drilling rig is under development that rotates coiled tubing (CT) downhole, reportedly at rates on the order of 20 RPM, resulting in numerous operational benefits. However, rotation will impose additional rotating-bending events in the high-cycle regime as sections of CT pass through regions of high dog leg severity. This paper presents a study of the influence of downhole rotation on the fatigue durability of CT. In this study, fatigue data taken in the high and low cycle regimes from a variety of sources are used to assess the potential high-cycle fatigue damage that may be caused by downhole rotation. The results indicate that the damage is below the endurance limit and thus negligible relative to fatigue damage accumulated from above-ground bend-straighten cycles for conventional CT. This analysis also took into account another area of potential concern: circumferential abrasion that could occur when rotating coiled tubing contacts with the casing and/or wellbore. Surface roughness factors were estimated and used to modify life estimates. Results still indicate that sub-surface rotation-induced fatigue cycles should not detrimentally influence fatigue life relative to above surface fatigue cycles.
Experimental results are presented which validate the conservatism of the assumptions made for surface roughness factors. The results also demonstrate that the abrasion process causes compressive residual surface stresses that somewhat offset the detrimental effect of a rougher surface.
A Fully Implicit, Compositional, Parallel Simulator for IOR Processes in Fractured Reservoirs
Authors: Naimi-Tajdar R. , Han C. , Sepehrnoori K. , Arbogast T. J. , Miller M. A. 
Published: December 2007

AbstractNaturally fractured reservoirs contain a significant amount of the world oil reserves. A number of these reservoirs contain several billion barrels of oil. Accurate and efficient reservoir simulation of naturally fractured reservoirs is one of the most important, challenging, and computationally intensive problems in reservoir engineering. Parallel reservoir simulators developed for naturally fractured reservoirs can effectively address the computational problem.A new accurate parallel simulator for large-scale naturally fractured reservoirs, capable of modeling fluid flow in both rock matrix and fractures, has been developed. The simulator is a parallel, 3D, fully implicit, equation-of-state compositional model that solves very large, sparse linear systems arising from discretization of the governing partial differential equations. A generalized dual porosity model, the multiple-interacting-continua (MINC), has been implemented in this simulator. The matrix blocks are discretized into subgrids in both horizontal and vertical directions to offer a more accurate transient flow description in matrix blocks. We believe this implementation has led to a unique and powerful reservoir simulator that can be used by small and large oil producers to help them in the design and prediction of complex gas and waterflooding processes on their desktops or a cluster of computers. Some features of this simulator, such as modeling both gas and water processes and the ability of two-dimensional matrix subgridding to the best of our knowledge are not available in any commercial simulator. The code was developed on a cluster of processors, which has proven to be a very efficient and convenient resource for developing parallel programs.The results were successfully verified against analytical solutions and commercial simulators (ECLIPSE and GEM). Excellent results were achieved for a variety of reservoir case studies. Applications of this model for several IOR processes (including gas and water injection) are demonstrated. Results using the simulator on a cluster of processors are also presented. Excellent speedups ratios were obtained.
Impact of Intelligent Wells on Oilfield Scale Management
Authors: Kavle V. , Elmsallati S. , Mackay E. , Davies D. 
Published: December 2007

Abstract
The main challenge facing the oil industry is to reduce development costs while accelerating recovery while maximising reserves. One of the key enabling technologies in this area is intelligent well completions. Downhole inflow control devices allow for the flexible operation of non-conventional wells. By placing sensors and control valves at the reservoir face, engineers can monitor reservoir and well performance in real time, analyse data, make decisions and modify the completion without physical intervention to optimise reservoir and asset performance. They provide the ability to independently control each valve individually from the surface to maximise oil production and/or minimise formation water and/or gas production. However, they may also be used to address other produced water management issues, such as inorganic scale control.
This paper describes the potential risks posed specifically to intelligent completions by scale deposition. The potential benefits to scale management that ICVs, such as control of scaling brine production and effective scale inhibitor placement, are described. Calculations are performed for a North Sea field with a barite scaling risk, and the cost benefit - specifically to scale management -of using ICVs is evaluated. These calculations demonstrate that intelligent completions significantly reduce the scale inhibitor chemical costs while improved scale inhibitor placement is achieved.
Advanced Collaborative Environments in BP
Authors: Edwards T. , Saunders M. , Moore-Cernoch K. 
Published: December 2007

Abstract
The Advanced Collaborative Environment (ACE) Programme is BP's strategic deployment vehicle for the global implementation of ‘Real Time’ Production and Drilling Operations Support Environments. ACE's are a key theme within BP's FIELD OF THE FUTURE technology leadership area.
This paper will describe current operational environments in Stavanger, Aberdeen, Houston and Baku and then move on describe future plans for multi-asset support environments to support Deep Water GOM assets, Caspian assets, North Sea operations. It will also highlight the opportunity for the fully collaborative office environments in a number of new office locations within BP.
BP believes that there are five key elements for success when implementing Advanced Collaborative Environments:
– People – Process – Technology – Physical Environment – Organisation
The integration of these five elements is the key to a successful ACE implementation.
The paper will conclude with a summary of some of the key business benefits attained from the application of ACE's with BP's drilling and production operations.
Observations on Characterization of Defects in Coiled Tubing From Magnetic-Flux-Leakage Data
Authors: McJunkin T. R. , Miller K. S. , Tolle C. R. 
Published: December 2007

Abstract
This paper presents observations on the sizing of automatically detected artificial flaws in coiled tubing samples using magnetic-flux-leakage data. Sixty-six artificial flaws of various shapes and types, ranging from 0.30 mm deep pits to slots with length of 9.5 mm, in 44.45 mm outer diameter pipe were analyzed. The detection algorithm and the information automatically extracted from the data are described. Observations on the capabilities and limitations for determining the size and shape of the flaws are discussed.
Challenges in Planning, Installation, and Operation of Coiled-Tubing Drilling Equipment on a North Sea Platform
Authors: Taggart M. , King J. A. 
Published: December 2007

Abstract
Coiled-tubing drilling (CTD) is a well-established, common application in some areas, particularly Western Canada. However this practice has not grown to similar activity levels in the North Sea. Two CTD projects have been carried out on UK North Sea platforms since 1999 and it is over 4 years since the most recent operation.
As a result of the sustained high oil price, North Sea operators are looking for methods of sidetracking existing wells to access isolated or stranded oil reserves. The condition of some North Sea drilling rigs is such that a significant financial investment is required if they are to return to conventional drilling. CTD is one option that enables operators to access these reserves, without the need to recommission the original drilling facility.
The extremely low activity levels of CTD in the UK has led to the challenge faced by service companies of supplying suitable equipment and experienced personnel, to safely and effectively manage and perform a CTD operation.
This paper discusses the challenges faced and some solutions developed for a recent CTD operation carried out on the Gannet ‘A’ platform, located in the Central North Sea.
In addition to the challenges mentioned above, to deliver a successful well, several new technologies and equipment were incorporated into the application of CTD to the Gannet field.
Reel-to-Injector Fluid-Flow Analysis Using CFD Software
Authors: Bailey M. B. , Blanco I. , Rosine R. S. 
Published: December 2007

Abstract
Until recently, fluid flow through coiled tubing (CT) was only discussed as a theory or an idea. With the aid of some sophisticated new software technology, Computational Fluid Dynamics (CFD), an understanding of the actual flow patterns of fluids in CT is now possible. This paper discusses a more complete study of multiple CT string components and their effect on fluid flow.
Analysis of individual components or systems has been performed, but combining systems can change the outcome of the results. Previous analysis simulated a straight section of tubing running through a tubing guide. This analysis assumed fully developed flow entering the straight section of tubing. Based on results of an industry consortium, the flow into the straight tubing coming off the reel may not be fully developed. To expand the study of the actual full-scale model of a CT string, in this study, additional portions of the string will be included. The fluid-flow phenomenon from the reel and its effect on the flow path in the straight section of the tubing between the reel and tubing guide will be incorporated into the model. The results could affect the centrifugal forces and flow-path patterns previously thought to affect erosion. Results generated from these studies could help in understanding erosion principles, including sand particle migration and movement.