bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signal transduction in CHO cells stably transfected with domain-selective forms of murine ACE
Authors: Sun Xiaoou , Rentzsch Brit , Gong Maolian , Eichhorst Jenny , Pankow Kristin , Papsdorf Gisela , Maul Björn , Bader Michael , Siems Wolf-Eberhard 
Published: December 2009

AbstractMembrane-bound human angiotensin-converting enzyme (ACE) has been reported to initiate intracellular signaling after interaction with substrates or inhibitors. Somatic ACE is known to contain two distinct, extracellular catalytic centers. We analyzed the signal transduction mechanisms in cells transfected with different forms of murine ACE (mACE) and investigated whether the two domains are similarly involved in these processes. For this purpose, CHO cells were stably transfected with mACE or with its domain-selective mutants. In addition to these modified cellular models, human umbilical vein endothelial cells were used in this study. Signal transduction molecules such as JNK and c-Jun were analyzed after activation of cells with several ACE substrates and inhibitors. ACE-targeting compounds such as substrates, inhibitors, or even the ACE product angiotensin-II induce in mACE-expressing cells a signal transduction response. These processes are also evoked by partially inactivated forms of mACE and finally result in an enhanced cyclooxygenase-2 transcription. Surprisingly, the membrane-bound ACE activity is also influenced by ACE-targeted interventions. Our data suggest that the two catalytic domains of mACE do not function independently but that the signal transduction is influenced by negative cooperativity of the two catalytic domains. This study underlines that ACE indeed has receptor-like properties which occur in a species-specific manner.
Ubiquitin ligase complexes: from substrate selectivity to conjugational specificity
Authors: Nagy Vanja , Dikic Ivan 
Published: December 2009

Abstract
Localization, activity and lifespan of a protein are signaled by a small, 8 kDa protein, ubiquitin (Ub). Ub conjugation is a post-translational modification orchestrated by the sequential action of activating (E1), conjugating (E2), and ligating (E3) enzymes. Although a simple combination of an E2 and an E3 enzyme can be sufficient for an active complex, in other cases ubiquitination can occur in the context of large multimeric complexes with enhanced molecular abilities. Here, we review several Ub ligase complexes to highlight strategies governing conjugational specificity, the gained adaptability in substrate specificity, and modulatory flexibility encoded in regulatory components of these diverse multimers.
Lack of Effect of Moderate Hepatic Impairment on the Pharmacokinetics of Telavancin
Authors: Goldberg Michael R. , Wong Shekman L. , Shaw Jeng‐Pyng , Kitt Michael M. , Barriere Steven L. 
Published: December 2009

Study Objective. To evaluate the pharmacokinetics of the lipoglycopeptide antibiotic, telavancin, in patients with moderate hepatic impairment compared with healthy controls.Design. Phase I, open‐label, single‐dose, matched‐control, pilot study.Setting. Clinical research unit.Participants. Eight adults with moderate hepatic impairment (Child‐Pugh class B) and eight age‐, sex‐, and weight‐matched healthy control subjects.Intervention. All participants received a single 1‐hour intravenous infusion of telavancin 10 mg/kg.Measurements and Main Results. Plasma samples were collected for pharmacokinetic analysis before the infusion and 1, 2, 4, 6, 8, 12, 24, 36, 48, and 72 hours after the start of the infusion. Concentrations of telavancin and the most prevalent of several minor hydroxylated metabolites, THRX‐651540, were assayed with a validated liquid chromatography‐tandem mass spectrometry technique. Telavancin binding to plasma proteins was determined in a preinfusion sample by using equilibrium dialysis. Pharmacokinetic parameters for telavancin and THRX‐651540 were generally similar between the hepatic impairment and control groups. The mean maximum plasma concentration was 21% lower in patients with hepatic impairment than in controls, which was a statistically (analysis of variance, p<0.05), but not clinically, significant difference. There were no other statistically significant between‐group differences. Adverse events were few and mild.Conclusion. No apparent differences were observed in the pharmacokinetic disposition of telavancin in patients with hepatic impairment compared with healthy controls in this pilot study. Thus, adjustment of the standard telavancin dosage regimen does not appear to be required in patients with mild‐to‐moderate hepatic impairment.
Implementation of Real-time Gas-lift Optimization in Dubai Offshore Fields
Authors: Shnaib Fathi , Nadar Manickam S. , McAlonan Nick 
Published: December 2009

AbstractDubai Petroleum (DP) has recently deployed software interface systems to perform real-time optimization of gas lifted wells offshore. Prior to this, gas lift optimization was initiated manually and was done four times a year. This paper presents the various aspects of the real-time optimization project and the benefits that are coming out of the project.The real-time optimization (RTO) is a giant step forward as it helps optimize the asset more frequently. This also makes it possible to identify under-performing wells as and when problems develop. In the past this often took several days, in an offshore environment with manpower and logistics constraints.The benefits of the RTO system would include the following: As the RTO interface feeds the latest well data into the well models held in a live server, the optimization system estimates the expected production from the wells and automatically identifies wells that are sub-optimal in their performance. The system flags those wells for immediate attention.The well models get automatically calibrated whenever a new production test becomes available. The result of the well model calibration (success or failure) is communicated with details as required.The wells will be optimized more frequently, and with the less use of engineering manpower.Using the real-time optimization systems the daily production from the asset can be accurately predicted. Integrating with bulk metering systems, the production can be back allocated to specific wells and the source of downtime / loss identified.By linking the RTO system to corporate KPI's e.g. targets (or capacities) engineers and managers can at a glance check the performance of the asset againt key production targets and spot possible optimization opportunities. They can then drill down into individual wells for detailed analysis.Some level of reservoir monitoring can be achieved by using the allocated production and injection to calculate Voidage Reservoir Ratio over time and also look at cumulative injection and production and the net offtake in the reservoir.Real-time optimization systems add significant value in large complex gas-lift operating systems. The available gas compression capacity often changes due to equipment related problems, maintenance activities and ambient conditions. It has been proven that for minor system upsets it is more efficient to redistribute the available lift gas rather than shutting-in wells. The real-time optimization system provides the best way to manage the field with the available lift gas at any point in time. As the system calculates the production from the asset using the live data and recently calibrated asset models, the production back allocation is more accurate and reliable.
First Worldwide Application of Fiber Optic Enabled Coiled Tubing with Multilateral Tool for Accessing and Stimulating a Trilateral Oil Producer, Saudi Arabia
Authors: Al-Zain Ahmed , Said Rifat , Gamber Salman , Al-Driweesh Saad , Al-Shahrani Khzam , Jacobsen Jan 
Published: December 2009

AbstractSince the advent of horizontal technology, new wells have been drilled with thousands of feet of horizontal section to expose large reservoir areas. The advancement of drilling technology also allows drilling more complex wells, such as multilaterals for maximum reservoir contact (MRC). These complex wells impose great challenges with respect to well accessibility for rigless well interventions. One of the initial well interventions, which follow drilling completion, is acid stimulation to remove formation damage.On the other hand, the recent advancement of coiled tubing (CT) enables rigless interventions of complex wells while acquiring real time downhole measurements. The fiber optic enabled coiled tubing (FOCT) provides combined services of data acquiring and running other CT tools required for well treatments. The fiber optic telemetry system consists of a pump-through bottom-hole assembly (BHA) with a casing collar locator (CCL), pressure and temperature sensors, optical fibers inside CT, and a surface readout unit. By the virtue of the optical fiber, distributed measurements are also viable options to obtain temperature profiles. The temperature surveys allow evaluating flow distribution through temperature responses, thereby optimizing acid stimulation.A multilateral tool (MLT) using an indexing flow activated bent sub allows locating and accessing the laterals and stimulating them. The CCL readings via the FOCT provide a real time confirmation of accessing laterals.This paper highlights the first worldwide CT application of combining the fiber optic telemetry system for acquiring downhole data on real time, and a multilateral tool for accessing and stimulating a trilateral oil producer in a major carbonate reservoir in Saudi Arabia. This combination has resulted in a successful optimized acid stimulation of all three laterals. This paper also discusses in detail the job execution challenges, lessons learned, and experience gained to optimize similar future jobs.
Effect of Surfactant Addition, Temperature, and Solvent conditions on Functional Microgels for Enhanced Oil recovery Applications
Authors: Al-manasir Nodar , Kjøniksen Anna-Lena , Zhu Kaizheng , Nyström Bo 
Published: December 2009

Abstract
Interactions between a chemically cross-linked poly(N-isopropylacrylamide) (PNIPAAM) microgel and the anionic surfactant sodium dodecyl sulfate (SDS) have been investigated by dynamic light scattering (DLS) and turbidimetry in both a buffer system (pH = 7) with an ionic strength of 0.05 M and water. Both the turbidity and DLS measurements revealed significant polymer-surfactant interactions between PNIPAAM and SDS in the buffer system, whereas in the absence of buffer only the highest SDS concentration clearly deviates from what is observed in the absence of surfactant. The DLS results show that the particles shrink with increasing temperature at all conditions; a macroscopic phase separation is approached at higher temperatures for the microgels without or with low SDS concentration in the buffer system. Mixtures of microgels and surfactants may be promising for enhanced oil recovery applications.
Mobile Production Testing: A Highly Accurate and Flexible Solution
Authors: Cadalen Sebastien , Chazal Damien , David Pierre-Yves , Elie Nicolas , Jolivet Guillaume 
Published: December 2009

Abstract
The use of multiphase flow meters (MPFM) for surface well production metering without separation of the phases is now an established practice in the oil industry and is a key element for production allocation, well performance optimization and reservoir monitoring.
In parallel, the demand for mobile testing with multiphase flow meters service is increasing and the challenges to face are numerous due to the wide range of wells flowrates, fluid characteristics (from heavy oil to gas-rich applications) and flow conditions (emulsions, foam, slug…).
Based on years of experience in field surveillance and multiphase flow metering, a new multiphase flow meter, designed to cover accurately both multiphase and wet gas flow conditions has been developped. The technology choices rely on robust and proven measurement principles used in multiphase flows while further developments have secured the performances under challenging conditions.
This paper describes the development of the solutions that allow this MPFM to achieve high performance in all flow conditions and presents the results obtained in various flow loops in the past two years.
Results confirm the accuracy of the technology under multiphase and wet gas conditions that will address a request of oil and gas producers for high performance metering systems.
This technology has been implemented in a compact and rugged mobile testing unit designed for mobile production testing. It includes two independent measuring sections (2" and 4") to cover low to high flow rate conditions. This feature, associated with the high performance of the measurement in multiphase and wet gas, provides a versatile service solution well-adapted to the various fluid and flow conditions encountered in oil & gas fields.
Selection of Proper Criteria in Flow Behavior Characterization of Low Tension Polymer Flooding in Heavy Oil Reservoirs
Authors: Jamaloei Benyamin Yadali , Kharrat Riyaz , Ahmadloo Farid 
Published: December 2009

Abstract
Applying a suitable enhanced oil recovery method to heavy oil reservoirs is still controversial. Low Tension Polymer Flooding (LTPF) can be considered when thermal and solvent-based methods are not feasible due to technical difficulties and/or economical/environmental constrains. Performance of LTPF, which uses cost-effective surfactant with dilute concentrations within the injected polymer solution, is noticeably far superior to that of alkali-surfactant flooding which suffers from sever viscous instability and/or weak in-situ surfactant generation due to inappropriate acid number of some heavy oils.
To properly characterize the microscopic and macroscopic flow behavior of LTPF in heavy oil displacement, the interplay between viscous, capillary, and gravitational forces should be identified by utilizing bond and capillary numbers. Unlike bond number, the capillary number has been defined in several forms by researchers many of which are not equivalent. An appropriate definition of the capillary number should be correctly selected and employed–according to the interest in scale and fluid-flow behavior–so as to quantify the impacts of selected capillary number on the hydrodynamic instability, relative permeability shifts, and phase trapping and bypassing in LTPF in heavy oil displacement.
In this study, the capillary number definitions (i.e., pore-scale, Newtonian-fluid, and apparent capillary numbers) were evaluated to determine an appropriate capillary number definition to quantify the LTPF in heavy oil displacement by employing physical modeling and numerical simulation. Moreover, the effects of pore size distribution and injection flowrate on above-mentioned three different capillary number definitions and their sensitivity to the change in those parameters were examined. It was inferred that the sensitivity of change in the pore-scale capillary number is appropriate to evaluate the phase trapping and bypassing whereas the apparent capillary number should be used to characterize the macroscopic behavior (e.g., relative permeability shifts, hydrodynamic instability, and recovery versus capillary number curves) of LTPF. The effects of the pore size distribution and injection flowrate on phase trapping and bypassing, which were rendered, can be considered as a practical guide to build a robust trapping model which is the key to properly simulate and optimize the entire LTPF in lab and field scales.
Deep Marrat Carbonate Reservoir Development & Production Challenges in Dharif Field of West Kuwait
Authors: Dakshinamurthy Natarajan , Salaam Tareq Abdul , Verma Naveen K , Al-Khamees Waleed 
Published: December 2009

ABSTRACT
The Marrat reservoir in Dharif field is a deep, sour, high pressure oil accumulation of Jurassic age containing light under-saturated oil of 36-38° API. The carbonate reservoir has a porosity range of 10-20% with permeability of 1-10 md. The field was put on production in 1989 through one well. Subsequently, 10 wells were added gradually developing the field. As of date, the field has produced about 12.5% of oil in place, lowering the reservoir pressure from 10,525 to 7,000 psi.
At present, oil production from the field is about 13,500 bbls/day. Due to low permeability, some wells produce with high drawdown approaching asphaltene onset pressure (AOP), estimated at 3,400 psi. This causes Asphaltene deposition in the tubing that requires cleaning to maintain the production level. The major challenges now are to produce the wells above AOP to avoid asphaltene precipitation in the wells or reservoir while sustaining the production level and maximizing recovery.
Hence, Full Field Model (FFM) for simulation studies was constructed and history-matched. Under depletion case, where the wells produce above AOP, field produced about 24% STOIIP. The water injection case shows significant increase in recovery to 40% STOIIP. Since no prior experience of water injection is available for such tight deep carbonate reservoirs in West Kuwait Fields, several key studies such as a) RCAL & SCAL b) Core flood Study c) Water Compatibility & Scale Prediction modeling d) Injectivity test, were carried out to address water injection feasibility.
The present paper shares the results of above studies which indicate that water injection is a viable option to maintain the reservoir pressure to produce the wells above AOP as well as to maximize recovery. Pilot water injection is planned through one well for which the area has been optimized using FFM. At present Pilot Water injector and source wells have been drilled and injection will be initiated with commissioning of surface facilities
New Approaches for Analyzing Transient Pressure from Oil And Water Two-Phase Flowing Reservoir
Authors: Zheng Shiyi , Xu Wenbin 
Published: December 2009

Abstract
Theory and practice in the past on well testing reservoir with multi-phase flow such as oil and water system achieved limited success. Methods include multi-phase pseudo-pressure, pressure squared and total compressibility, total mobility, i.e. Perrine- Martin (P-M) method. As recognized by the industry, multi-phase pseudo-pressure approach was flawed, while only P-M method is applicable in strictly oil-water system.
Multi-phase flow well testing research subject attracted the oil industry's interest again is purely due to the onset of permanent down hole gauge (PDG), which made long term multi-phase flow transient pressure data at every stage available.
This paper explored in depth the problem of well testing in oil-water two-phase flowing system further. Four types of flow mechanisms were modeled and studies were conducted through numerical well testing. These are: (1) dispersed flow with uniform saturation; (2) dispersed flow with non-uniform saturation; (3) oil-water segregated flow and (4) oil reservoir with aquifer-support. Case (1) is an ideal case, where oil and water assumed to be fully dispersed across the entire reservoir thickness. But in practice, water saturation is non-uniform in reservoir, so it is in fact the case (2). Case (3), segregated flow occurs when gravity forces are dominating, leading to complete segregation of oil overlying water. Such situation can also be due to early water breakthrough in layered reservoir with high permeability formation. Case (4) characterizes the situation where the well is completed in part of the formation away from the water formation in order to prevent water coning. This will create a different flow problem due to spherical flow.
Transient data were generated through numerical experiments for every defined flow mechanisms above. Considering relative permeability curves, traditional P-M method was fully examined and modified to obtain the true reservoir properties such as absolute permeability in these situations. Following the numerical well testing procedures, interpretation issues due to the difference between the theory and practice were addressed much more properly and clear.
Cerebral Metabolic Alterations in Rats With Diabetic Ketoacidosis
Authors: Glaser Nicole , Yuen Natalie , Anderson Steven E. , Tancredi Daniel J. , O'Donnell Martha E. 
Published: December 2009

OBJECTIVE
Cerebral edema is a life-threatening complication of diabetic ketoacidosis (DKA) in children. Recent data suggest that cerebral hypoperfusion and activation of cerebral ion transporters may be involved, but data describing cerebral metabolic alterations during DKA are lacking.

RESEARCH DESIGN AND METHODS
We evaluated 50 juvenile rats with DKA and 21 normal control rats using proton and phosphorus magnetic resonance spectroscopy (MRS). MRS measured cerebral intracellular pH and ratios of metabolites including ATP/inorganic phosphate (Pi), phosphocreatine (PCr)/Pi, N-acetyl aspartate (NAA)/creatine (Cr), and lactate/Cr before and during DKA treatment. We determined the effects of treatment with insulin and intravenous saline with or without bumetanide, an inhibitor of Na-K-2Cl cotransport, using ANCOVA with a 2 × 2 factorial study design.

RESULTS
Cerebral intracellular pH was decreased during DKA compared with control (mean ± SE difference −0.13 ± 0.03; P &lt; 0.001), and lactate/Cr was elevated (0.09 ± 0.02; P &lt; 0.001). DKA rats had lower ATP/Pi and NAA/Cr (−0.32 ± 0.10, P = 0.003, and −0.14 ± 0.04, P &lt; 0.001, respectively) compared with controls, but PCr/Pi was not significantly decreased. During 2-h treatment with insulin/saline, ATP/Pi, PCr/Pi, and NAA/Cr declined significantly despite an increase in intracellular pH. Bumetanide treatment increased ATP/Pi and PCr/Pi and ameliorated the declines in these values with insulin/saline treatment.

CONCLUSIONS
These data demonstrate that cerebral metabolism is significantly compromised during DKA and that further deterioration occurs during early DKA treatment—consistent with possible effects of cerebral hypoperfusion and reperfusion injury. Treatment with bumetanide may help diminish the adverse effects of initial treatment with insulin/saline.
Gene Variants of TCF7L2 Influence Weight Loss and Body Composition During Lifestyle Intervention in a Population at Risk for Type 2 Diabetes
Authors: Haupt Axel , Thamer Claus , Heni Martin , Ketterer Caroline , Machann Jürgen , Schick Fritz , Machicao Fausto , Stefan Norbert , Claussen Claus D. , Häring Hans-Ulrich , Fritsche Andreas , Staiger Harald 
Published: December 2009

OBJECTIVE
The impact of the diabetes risk gene transcription factor 7-like 2 (TCF7L2) on body weight is unclear. As TCF7L2 is expressed in adipose tissue and involved in Wnt-dependent regulation of adipogenesis, we studied the impact of TCF7L2 variants on body composition and weight loss during lifestyle intervention.

RESEARCH DESIGN AND METHODS
We genotyped 309 German subjects at increased risk for type 2 diabetes for single nucleotide polymorphisms (SNPs) rs7903146, rs12255372, rs11196205, and rs7895340 in TCF7L2 and performed oral glucose tolerance tests before and after a 9-month lifestyle intervention. Fat distribution was quantified using whole-body magnetic resonance imaging/spectroscopy in a subgroup of 210 subjects.

RESULTS
After adjustment for confounding variables, we observed a negative impact of the type 2 diabetes allele of SNP rs7903146 on change in BMI (P = 0.0034) and on changes in nonvisceral (P = 0.0032) and visceral fat (P = 0.0165) during lifestyle intervention. An association of rs7903146 with lifestyle intervention-induced changes in insulin secretion, glucose concentrations, liver fat, or insulin sensitivity were not detected (all P &gt; 0.2). Essentially the same results were obtained with SNP rs1255372. In contrast, we found no effects of SNPs rs11196205 and rs7895340 on change in BMI (all P ≥ 0.5).

CONCLUSIONS
Our data reveal that diabetes-associated alleles of TCF7L2 are associated with less weight loss in response to lifestyle intervention. Thus, diabetes-associated TCF7L2 gene variation predicts the success of lifestyle intervention in terms of weight loss and determines individual susceptibility toward environmental factors.