bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Different Antiasthmatic Treatments on Exercise-Induced Bronchoconstriction in Children With Asthma
Authors: Kennedy Joshua L. , Jones Stacie M. 
Published: October 2008

Stelmach I, Grzelewski T, Majak P, Jerzynska J, Stelmach W, Kuna P. J Allergy Clin Immunol. 2008;121(2):383–389
PURPOSE OF THE STUDY. To compare the effectiveness of different patterns of antiasthmatic treatments to protect children from exercise-induced bronchospasm (EIB).
STUDY POPULATION. This was a randomized, double-blind, placebo-controlled study of 100 children aged 6 to 18 years with atopic asthma sensitive only to house dust mites and EIB. Subjects must have had a resting forced expiratory volume in 1 second (FEV1) of ≥70% predicted and at least a 20% drop in FEV1 after exercise to qualify for the study.
METHODS. Participants were randomly assigned to a 4-week double-blind, placebo-controlled trial to receive 1 of the following treatments: (1) budesonide 100 μg + formoterol 4.5 μg twice daily; (2) budesonide 100 μg twice daily + montelukast 5 or 10 mg at bedtime; (3) montelukast 5 or 10 mg at bedtime; (4) budesonide 100 μg twice daily; or (5) placebo alone. All study arms had matching placebo medications from which active drugs were omitted (eg, group 1 had placebo tablets in place of montelukast, etc). At randomization and after 4 weeks on the study medication(s), a treadmill exercise test was performed to evaluate the effectiveness of treatment.
RESULTS. Ninety-one subjects with a median age of 11.3 to 12.2 among the groups completed the study. Preexercise FEV1 and EIB, as represented by the area under the curve of time-response curve and by maximum percentage decrease in FEV1 after exercise, did not differ at baseline between the groups. EIB was diminished with all treatments when compared with placebo. The effect of treatment with budesonide plus montelukast and with montelukast alone were greater than budesonide alone or budesonide plus formoterol (P &lt; .001). The budesonide-plus-formoterol group was also better than budesonide alone, but these results did not reach significance (P = .59).
CONCLUSIONS. Budesonide plus montelukast or montelukast alone were the most effective treatments for EIB in children.
REVIEWER COMMENTS. This was the first study in asthmatic children that evaluated both monotherapy and combination therapy for the reduction of EIB. This study highlights the importance of controller therapy in childhood asthma and the effects on EIB between therapeutic options recommended for childhood asthma. In particular, consideration for the use of montelukast as monotherapy or in combination therapy with inhaled corticosteroids is indicated for EIB in children with similar asthmatic phenotypes.
A Novel Method of Dynamic Culture Surface Expansion Improves Mesenchymal Stem Cell Proliferation and Phenotype
Authors: Majd Hicham , Wipff Pierre-Jean , Buscemi Lara , Bueno Manuel , Vonwil Daniel , Quinn Thomas M. , Hinz Boris 
Published: October 2008

Abstract
Repeated passaging in conventional cell culture reduces pluripotency and proliferation capacity of human mesenchymal stem cells (MSC). We introduce an innovative cell culture method whereby the culture surface is dynamically enlarged during cell proliferation. This approach maintains constantly high cell density while preventing contact inhibition of growth. A highly elastic culture surface was enlarged in steps of 5% over the course of a 20-day culture period to 800% of the initial surface area. Nine weeks of dynamic expansion culture produced 10-fold more MSC compared with conventional culture, with one-third the number of trypsin passages. After 9 weeks, MSC continued to proliferate under dynamic expansion but ceased to grow in conventional culture. Dynamic expansion culture fully retained the multipotent character of MSC, which could be induced to differentiate into adipogenic, chondrogenic, osteogenic, and myogenic lineages. Development of an undesired fibrogenic myofibroblast phenotype was suppressed. Hence, our novel method can rapidly provide the high number of autologous, multipotent, and nonfibrogenic MSC needed for successful regenerative medicine.
Chromatin Modifications in Hematopoietic Multipotent and Committed Progenitors Are Independent of Gene Subnuclear Positioning Relative to Repressive Compartments
Authors: Guillemin Claire , Maleszewska Marta , Guais Adeline , Maës Jérôme , Rouyez Marie-Christine , Yacia Azzedine , Fichelson Serge , Goodhardt Michele , Francastel Claire 
Published: October 2008

Abstract
To further clarify the contribution of nuclear architecture in the regulation of gene expression patterns during differentiation of human multipotent cells, we analyzed expression status, histone modifications, and subnuclear positioning relative to repressive compartments, of hematopoietic loci in multipotent and lineage-committed primary human hematopoietic progenitors. We report here that positioning of lineage-affiliated loci relative to pericentromeric heterochromatin compartments (PCH) is identical in multipotent cells from various origins and is unchanged between multipotent and lineage-committed hematopoietic progenitors. However, during differentiation of multipotent hematopoietic progenitors, changes in gene expression and histone modifications at these loci occur in committed progenitors, prior to changes in gene positioning relative to pericentromeric heterochromatin compartments, detected at later stages in precursor and mature cells. Therefore, during normal human hematopoietic differentiation, changes in gene subnuclear location relative to pericentromeric heterochromatin appear to be dictated by whether the gene will be permanently silenced or activated, rather than being predictive of commitment toward a given lineage.
Generation of T Lineage Cells from Human Embryonic Stem Cells in a Feeder Free System
Authors: Galić Zoran , Kitchen Scott G. , Subramanian Aparna , Bristol Greg , Marsden Matthew D. , Balamurugan Arumugam , Kacena Amelia , Yang Otto , Zack Jerome A. 
Published: October 2008

Abstract
Human embryonic stem cells (hESC) have the potential to revolutionize certain medical treatments, including T-cell-based therapies. However, optimal approaches to develop T cells from hESC are lacking. In this report, we show that T-cell progenitors can be derived from hESC cultured as embryoid bodies (EBs). These EB-derived T-cell progenitors give rise to phenotypically and functionally normal cells of the T lineage when transferred into human thymic tissue implanted in immunocompromised mice, suggesting that introduction of these progenitors into patients may also yield functional T cells. Moreover, hematopoietic progenitors demonstrating T-cell potential appeared to be CD45+/CD34+, resembling those found in normal bone marrow. In contrast to T cells developed from hESC cocultured on murine stromal cells, the EB-derived T cells also expressed normal levels of CD45. Importantly, the EB system eliminates the previous need for murine cocultures, a key impediment to developing a protocol for T-cell progenitor derivation suitable for clinical use. Furthermore, following lentiviral-mediated introduction of a vector expressing enhanced green fluorescent protein into hESC, stable transgene expression was maintained throughout differentiation, suggesting a potential for gene therapy approaches aimed at the augmentation of T-cell function or treatment of T-cell disorders.
Application and Evaluation of Tubing-Conveyed Perforating System Combined with Sucker Rod Pump Installation
Authors: Ghareeb Mohamed , Shedid Shedid A. , Amani Mahmood 
Published: October 2008

Abstract
Underbalanced tubing conveyed perofration (TCP) attained higher production and assured safety when applied with sucker-rod pump installation in wells in three different Egyptian oil fields. The TCP allowed more efficient operation because it does not require killing the well after perforation to run the downhole pump and sucker rod. The overbalanced perforation eliminates the risks of damaging the producing formation beyond the perforations.
The compared performance of wells using underbalanced TCP with that of other wells using tubing gun technique, casing gun technique eveals that the underbalanced TCP prevailed successful in all cases.
The Integrated Use of New Technology in the Development of the Sakhalin II Project
Authors: Gunningham Mike , Varley Chris 
Published: October 2008

Abstract
The Sakhalin II Project, the world’s largest E&P project, is currently developing 2 oil and gas fields, offshore Sakhalin Island off the east coast of mainland Russia. This is a challenging area for exploration and development, with 4.5 Billion BOE (675 Million tonnes oil equivalent) of oil and gas in place. This paper will outline how new technologies have assessed and realized the Project’s potential.
Integrated Reservoir Modeling, utilizing modern seismic processing and interpretation, to evaluate short, medium- and long-term subsurface uncertainties, and to support development planning and reservoir management. The results have been combined into a fully integrated production system model from each reservoir to the LNG plant and Oil Export Terminal.
The Lunskoye field, which is being developed with the highest capacity gas wells in Russia, has used the latest sand failure prediction software, which can quantify sand production, so that gas production is optimized, while minimizing sand production. Production performance is enhanced using the latest perforating optimization software.
In the Piltun-Astokh field, Smart Water Injectors are used to allocate water into multiple layers to optimize reservoir recovery. In addition, extended reach wells are tapping into undrained areas of the field, to recover additional reserves, reducing the environmental footprint. The field will also be developed with the latest in Smart Field technology for well and reservoir management, using tools such as Fieldware. Longer term, 4-D seismic, using whale friendly seismic, will be implemented to identify infill drilling locations.
For the future, in this sub-Arctic environment, the opportunities include acquiring seismic under ice, Arctic (ice resistant) jack-up drilling rigs for year-round drilling and developing low-cost facilities, which can withstand the ice or even be installed subsea, under ice.
Creative Production Enhancement Applications of Relative Permeability Modifiers in Mature Fields
Authors: Kalfayan Leonard , Qu Qi , Stolyarov Sergey 
Published: October 2008

Abstract
There is increasing emphasis on enhancing production and extending economic life of mature fields, especially including waterflood operations, globally. With that, it stands to reason that greater focus should be placed on controlling production of unwanted water relative to oil and gas production, as well as on improving the utilization of the large volumes of water to optimize waterflood sweep efficiency.
Mechanical and chemical treatment methods for shutting off or at least controlling, unwanted water production have existed for many years. Technologies and methods continue to evolve, albeit slowly. The same is true for injection well treatments for profile modification and improved oil reservoir sweep efficiency purposes. In the family of chemical treatments confined to production wells for controlling water rate are the so-called relative permeability modifiers (RPMs). Despite the long-standing (and continuing) skepticism of RPMs, in general, their implementation has increased in recent years – including uses in conjunction with oil and gas well stimulation treatments. Certainly, some of the criticism of RPMs is justified as they are often misapplied beyond their realistic physical and chemical capabilities. However, the creative application of RPM chemistry in production enhancement applications and in waterflood operations should not be generally dismissed or discouraged.
This paper discusses creative uses of RPM systems with properties conducive to application in both matrix and naturally-fractured sandstones and carbonates. Such applications include using RPM systems in hydraulic fracturing, acidizing, scale removal and inhibition, salt block inhibition, and waterflood injection profile modification. Both conceptual and field-proven applications are included. Results of laboratory studies and field case examples are presented.
Solving Linear Equations in Reservoir Simulation Using Multigrid Methods
Authors: Hammersley R. P. , Ponting D. K. 
Published: October 2008

Abstract
The sets of linear equations which arise in large scale reservoir simulation can present problems for traditional linear solution algorithms. These scale poorly as the number of cells increases, and convergence is limited by the use of permeability distributions from geological modelling, with correlated high permeability channels, and the modelling of long horizontal wells. In addition, there is a requirement that the solver runs well on computers with many parallel processors.
The use of multi-level methods offers the possibility of good scaling with problem size. A common approach has been to use an algebraic multigrid (AMG) method. The integration of such a technique into a parallel reservoir simulation code is described, and the performance of different coarsening and interpolation algorithms compared.
AMG methods generally perform well when solving for a scalar solution to a system of elliptic equations and are not as straightforward to generalize to vector solution variables as traditional grid-based solvers. However, in fully implicit reservoir simulation a solution change in terms of both pressures and saturations or molar densities is generally required. This has lead to the use of solvers which combine an AMG step with a secondary solver step. There can be advantages in selecting nonlinear variables and equation sets to suit this technique, rather than treating the linear solver as a self-contained black box. Such methods are described and compared with traditional methods for black oil and compositional simulation.
Utilize Manage Pressure Drilling Equipment and Technique to Cement a Severely Depleted HPHT Reservoir in the North Sea
Authors: Bjørkevoll Knut Steinar , Molde Dag Ove , Fjeldberg Helge 
Published: October 2008

Abstract
The paper describes the successful use of an advanced comprehensive managed pressure setup to run and cement a liner that covered reservoir layers with pressures ranging from no depletion to 130 bar depletion in the Kvitebjorn field in the North Sea. The setup, which was first used for drilling the same 8.5" section, included a rotary control head, use of Cs/K formate mud, automatic choke on return flow, and an advanced online dynamic flow and temperature model for calculation of choke pressure set-point. The model was also used for pre-calculations of various scenarios to be prepared for different eventualities.
The paper describes methods and setup, planning and execution of operations, analyzes calculations vs. measured data, and discusses training and organizational aspects of conducting such a complex operation.
The managed pressure setup was motivated by several occasions of losses, partly severe, in nearby wells, and a narrow drilling window.
This is, to the authors’ knowledge, the first time running and cementing a liner has been done with an automatic choke system controlled in real time by an online dynamic flow model. Managed pressure cementing has been done earlier on the Gullfaks field in the North Sea, but then with a manually operated rig choke based on pre-calculated pressures only.
After having resolved a number of technical issues and trained thoroughly personnel for using the actual set-up, running and cementing liner could be conducted with good pressure control, and with no significant losses of drilling fluid. Later logging confirmed that the cement job was good.
Important factors to ensure high probability of success included thoroughly tested equipment and model,good knowledge of limitations of the system,comprehensive preparations, including pre-simulations and training,detailed procedures, including contingencies,good communication during operations
Wax Modeling: There is Need for Alternatives
Authors: Bagatin R. , Busto C. , Correra S. , Margarone M. , Carniani C. 
Published: October 2008

Abstract
Wax deposition in pipelines is a constant concern in Flow Assurance studies. When the temperature along a pipeline falls below the so-called Wax Appearance Temperature (WAT) of the oil, various problems due to wax precipitation and deposition may happen: wax can deposit on pipewalls, wax particles can increase the viscosity, and, due to plant shut-down, wax can cause the crude oil to gel. To counter-act wax problems, two approaches are possible: prevention (like e.g. insulating the pipe or adding chemicals to the oil) or removal (like e.g. pigging the line). In order to correctly design pipelines and to implement proper strategies for prevention and removal, a reliable description of the phenomenon plays a key role: without such a model, every intervention has to be oversized, dramatically increasing costs and risks.
A number of commercial codes have been developed to describe the deposition process based on a number of mechanisms (molecular diffusion, shear dispersion, Brownian diffusion, gravity settling ...) that have been proposed to elucidate the evolution of wax deposits on cold pipe walls. The comparison of these different commercial codes to each other, and with field data, represents a first result of this study. The models still present limits, many of which relate to the practical reliability of model predictions and their impact on operations:
– The relative importance of the different and/or concomitant mechanisms proposed for wax deposition modelling is still not completely clarified. – The models present a number of arbitrary or not well defined values of parameters that are often used to adjust predictions with respect to a specific experimental result. – The models have been developed using gel deposition rates observed in the laboratory flow loops and the scale-up of the deposition usually leads to an over-prediction of the wax deposition in field pipelines, due to the unavailability of a reliable upscale criterion.
In addition, the lack of detailed field data makes the qualification of the different models difficult.
Due to the failure of available models, the consolidated proposed mechanisms of wax deposition have been critically analysed. It resulted that there is need for alternatives: molecular diffusion controls wax radial transport, but this is not the only process that counts. Convective axial transport brings enough waxes to form a gel on the wall, and this gel formation is the fast process responsible of the deposit geometry.
On these bases, a new approach has been developed founded on this physical picture of the process; the comparison of its results with field data is by far better than the other ones.
Squeezing Scale Inhibitors to Protect Electric Submersible Pumps in Highly Fractured, Calcium Carbonate Scaling Reservoirs
Authors: Poynton Neil , Miller Alan , Konyukhov Dmitry , Leontieff Andre , Ganiev Ilgiz , Voloshin Alexander 
Published: October 2008

Abstract
Rosneft has oil fields in Western Siberia producing fluids from a number of wells via Electric Submersible Pumps (ESP's). While production rates are increased using ESP's, run time can be compromised by the formation of scale within the inner workings of the pump. The deposition of scale can be detected by the pumps requiring increasing amounts of current to maintain the flow rates. Eventually the pumps fail (either mechanically or electrically) and have to be replaced. Typically examination of these pumps indicated the main failure mechanism to be the deposition of Calcium Carbonate scale within the pump. The actual run times achieved tend to be dependant on the severity of the scaling produced water, but were typically in the order of weeks. However in some extreme cases, pump failures had occurred in a matter of days from replacement and start up.
It was proposed that one treatment strategy to increase the pump run time by inhibiting scale formation was via a Scale Inhibitor Squeeze application treatment. The Squeeze process and inhibitor application is very well understood, but to get successful squeeze treatment you need to perform adequate laboratory selection tests, including inhibition efficiency testing and core flood evaluations. This data, together with the Heriot Watt University Squeeze VI modeling can get an approximation to the potential squeeze life.
This paper presents the testwork performed to identify and develop successful Scale Inhibitor Squeeze Chemistries suitable for application in Western Siberia. It details the laboratory testing, the coreflood evaluation and Squeeze VI modeling. The Squeeze application and performance of the first well squeezed is reviewed together with a summary of the current status of the wells squeezed. An economic evaluation of the squeeze is also performed together with a summary of all the wells treated which demonstrates that the squeeze application provided a very cost effective method of scale control to maximize pump run time and increase the net well value.
Model for Transient Temperature and Pressure Behavior in Commingled Vertical Wells
Authors: Sui W. , Zhu D. , Hill A. D. , Ehlig-Economides C. A. 
Published: October 2008

Abstract
Multilayer transient testing is designed for determining individual layer properties (permeability and skin) for multiple layers commingled in a well. Traditional multilayer transient testing requires a combination of rate profiles from production log and transient rate and pressure measurements acquired at multiple surface rates. This method can be time consuming and may involve significant errors depending on the accuracy of the transient flow rate measurements. Today, many wells are equipped with downhole sensors that provide distributed or multipoint temperature measurements along the wellbore. Using these data to determine formation properties can minimize time and disturbances in well production. This paper presents a forward model to investigate the possibility of evaluating formation properties from transient temperature and pressure measurements. The model couples wellbore and reservoir models for simulating transient temperature and pressure for single-phase flow.
The wellbore model was developed based on mass, momentum, and energy balance. The reservoir model consists of a reservoir thermal model and a pressure/flow-rate transient model. Besides heat conduction and convection, it considers viscous heating and temperature variation due to fluid and rock expansion/compression. Wellbore and reservoir models are solved numerically to predict transient temperature and pressure behavior.
Comprehensive experiments reveal the sensitivities of transient temperature to individual layer permeability and skin values in multilayer systems. The results indicate that there are two main mechanisms governing wellbore transient temperature behavior; formation heating/cooling and wellbore fluid mixing at entry points, and that permeability and skin affect transient temperature and pressure differently. Examples in the paper show that the transient temperature response can distinguish between low permeability and high skin factor as reasons for low productivity in any layer. Additionally, this work revealed that the transient temperature behavior is sensitive to the radius of the damaged zone, suggesting for the first time a mechanism to quantify the damaged radius. The observations show promise of using transient temperature and pressure to determine multilayer formation properties.