bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long-term Follow-up and Outcome of Phenylketonuria Patients on Sapropterin: A Retrospective Study
Authors: Keil Stefanie , Anjema Karen , van Spronsen Francjan J. , Lambruschini Nilo , Burlina Alberto , Bélanger-Quintana Amaya , Couce Maria L. , Feillet Francois , Cerone Roberto , Lotz-Havla Amelie S. , Muntau Ania C. , Bosch Annet M. , Meli Concetta A.P. , Billette de Villemeur Thierry , Kern Ilse , Riva Enrica , Giovannini Marcello , Damaj Lena , Leuzzi Vincenzo , Blau Nenad 
Published: May 2013

OBJECTIVE:
Sapropterin dihydrochloride, the synthetic form of 6R-tetrahydrobiopterin (BH4), is an approved drug for the treatment of patients with BH4-responsive phenylketonuria (PKU). The purpose of this study was to assess genotypes and data on the long-term effects of BH4/sapropterin on metabolic control and patient-related outcomes in 6 large European countries.

METHODS:
A questionnaire was developed to assess phenotype, genotype, blood phenylalanine (Phe) levels, Phe tolerance, quality of life, mood changes, and adherence to diet in PKU patients from 16 medical centers.

RESULTS:
One hundred forty-seven patients, of whom 41.9% had mild hyperphenylalaninemia, 50.7% mild PKU, and 7.4% classic PKU, were followed up over ≤12 years. A total of 85 different genotypes were reported. With the exception of two splice variants, all of the most common mutations were reported to be associated with substantial residual Phe hydroxylase activity. Median Phe tolerance increased 3.9 times with BH4/sapropterin therapy, compared with dietary treatment, and median Phe blood concentrations were within the therapeutic range in all patients. Compared with diet alone, improvement in quality of life was reported in 49.6% of patients, improvement in adherence to diet was reported in 47% of patients, and improvement in adherence to treatment was reported in 63.3% of patients. No severe adverse events were reported.

CONCLUSIONS:
Our data document a long-term beneficial effect of orally administered BH4/sapropterin in responsive PKU patients by improving the metabolic control, increasing daily tolerance for dietary Phe intake, and for some, by improving dietary adherence and quality of life. Patient genotypes help in predicting BH4 responsiveness.
Accuracy of Point-of-Care Ultrasound for Diagnosis of Skull Fractures in Children
Authors: Rabiner Joni E. , Friedman Lana M. , Khine Hnin , Avner Jeffrey R. , Tsung James W. 
Published: May 2013

OBJECTIVE:
To determine the test performance characteristics for point-of-care ultrasound performed by clinicians compared with computed tomography (CT) diagnosis of skull fractures.

METHODS:
We conducted a prospective study in a convenience sample of patients ≤21 years of age who presented to the emergency department with head injuries or suspected skull fractures that required CT scan evaluation. After a 1-hour, focused ultrasound training session, clinicians performed ultrasound examinations to evaluate patients for skull fractures. CT scan interpretations by attending radiologists were the reference standard for this study. Point-of-care ultrasound scans were reviewed by an experienced sonologist to evaluate interobserver agreement.

RESULTS:
Point-of-care ultrasound was performed by 17 clinicians in 69 subjects with suspected skull fractures. The patients’ mean age was 6.4 years (SD: 6.2 years), and 65% of patients were male. The prevalence of fracture was 12% (n = 8). Point-of-care ultrasound for skull fracture had a sensitivity of 88% (95% confidence interval [CI]: 53%–98%), a specificity of 97% (95% CI: 89%–99%), a positive likelihood ratio of 27 (95% CI: 7–107), and a negative likelihood ratio of 0.13 (95% CI: 0.02–0.81). The only false-negative ultrasound scan was due to a skull fracture not directly under a scalp hematoma, but rather adjacent to it. The κ for interobserver agreement was 0.86 (95% CI: 0.67–1.0).

CONCLUSIONS:
Clinicians with focused ultrasound training were able to diagnose skull fractures in children with high specificity.
Effectiveness of Hormonal and Surgical Therapies for Cryptorchidism: A Systematic Review
Authors: Penson David , Krishnaswami Shanthi , Jules Astride , McPheeters Melissa L. 
Published: May 2013

BACKGROUND AND OBJECTIVE:
Controversy remains concerning the optimal treatment approach for cryptorchidism. The objective of this study was to assess effectiveness of hormone therapy or surgery for cryptorchidism.

METHODS:
We searched Medline and other databases from 1980 to February 2012. Two reviewers independently assessed studies against predetermined criteria. Two reviewers independently extracted data and assigned overall quality and strength of evidence ratings using predetermined criteria.

RESULTS:
Fourteen studies addressed effectiveness of hormonal treatments, and 26 studies addressed surgical intervention outcomes. Hormonal treatment is associated with testicular descent in some children, but rates generally do not exceed those seen with placebo by &gt;10%. Surgical treatment is associated with success rates of testicular descent ranging from 33% to 100%, depending on surgery. Weighted success averages were 78.7% for 1-stage Fowler-Stephens (FS), 86% for 2-stage FS, and 96.4% for primary orchiopexy. Descent rates were similar among studies comparing laparoscopic and open surgeries. Reported harms of hormonal treatments were mild and transient. Adverse effects specifically associated with surgical repair were rare.

CONCLUSIONS:
The body of the reviewed literature comprises primarily fair- and poor-quality studies, limiting our ability to draw definitive conclusions. Hormonal treatment is marginally effective relative to placebo but is successful in some children and with minimal harms, suggesting that it may be an appropriate trial of care for some patients. Surgical options are effective, with high rates of testicular descent (moderate strength of evidence for FS procedures, high for primary orchiopexy). Comparable outcomes occur with laparoscopic and open approaches.
Magnetic Resonance Imaging for Locating Nonpalpable Undescended Testicles: A Meta-analysis
Authors: Krishnaswami Shanthi , Fonnesbeck Christopher , Penson David , McPheeters Melissa L. 
Published: May 2013

BACKGROUND AND OBJECTIVE:Preoperative imaging techniques may guide management of nonpalpable, cryptorchid testicles. We evaluated conventional MRI for identifying and locating nonpalpable testicles in prepubescent boys via meta-analysis.METHODS:Databases including Medline were searched from 1980 to February 2012. Eligible studies included ≥10 boys with cryptorchidism/suspected cryptorchidism and reported data on testicular presence/absence and position (abdominal, inguinal, or scrotal) as determined by imaging and surgery. Two investigators independently reviewed studies against inclusion criteria. We captured the number of testicles that were correctly and incorrectly identified and located, relative to surgically verified status, and estimated sensitivity and specificity by using a random-effects model.RESULTS:Eight unique prospective case series included 171 boys with 193 nonpalpable testicles (22 with bilateral testicles). Surgery identified 158 testicles (81.9%) present and 35 absent. MRI correctly identified testicles with an estimated median sensitivity of 0.62 (95% Bayesian credible interval [BCI]: 0.47–0.77) and a specificity of 1.0 (95% BCI: 0.99–1.0). MRI located intraabdominal testicles with a sensitivity of 0.55 (95% BCI: 0.09–1.0) and inguino-scrotal testicles with a sensitivity of 0.86 (95% BCI: 0.67–1.0). We were not able to obtain estimates for MRI sensitivity or specificity for locating atrophied testicles. The estimated specificity for location-specific testicles reached almost 100%.CONCLUSIONS:Conventional MRI has low sensitivity for estimating the population sensitivity for identifying the presence of nonpalpable cryptorchid testicles. When testicles are identified, MRI is poor at locating both atrophied and intraabdominal testicles but performs modestly well in locating those in the inguino-scrotal regions.
Implementation of Bottom-Drive Progressive-Cavity Pumps Technology in La Cira-Infantas Oil Field as a Reliable Artificial Lift Method
Authors: Bohorquez M.. , Rubiano E.. , Labrador L.. , Suarez M. C. 
Published: May 2013

Abstract
Most common failures in the conventional artificial lift systems (Progressive cavity pumps and Sucker rod systems) currently used in La Cira - Infantas field are due to rod string and tubing failures; mainly root causes identified are friction rod string-tubing and combined friction-corrosion which causes both rod and tubing failures. The aim of the bottom drive progressive cavity pumping systems also called Electrical Submersible Progressive Cavity Pumps (ESPCP) project in La Cira Infantas Field is to improve artificial lift systems run life by reduction of premature failures occurred in the rod and/or tubing string.
ESPCP technology is a combination of Progressive Cavity Pump (PCP) and Electrical Submersible Pump (ESP) as an innovating artificial lifting method integrates the advantages of both systems, with compact surface equipment at the same time. PCP pump is an excellent choice for heavy oil and sandy fluids; however, rod pumps and rod driven PCP’s has also a limitation in highly deviated wells, pump speed and pump depth. By eliminating the need to drive the pump from surface by using a rod string represents a significant increase of equipment run life, reducing operating costs by intervention.
Field test was performed as initial phase by installation of three systems, successfully running at this point. Phase two was the implementation of 17 systems in different flow ranges. This paper will discuss the technical and economical advantages, highlights, specifications and history cases. Finally, phase three is the implementation of ESPCP in the field as preferred system to produce the called intermediate flow rate wells.
Automated Surface Gas Handling Through Expert Systems for Optimization of Artificial Lift Systems
Authors: Ramírez Miguel , Brunings Carlos 
Published: May 2013

ABSTRACT
In reservoirs with a gas drive production mechanism, as the down hole pressure drops below the bubble point, gas breaks out of solution, and depending on the gas to oil ratio (GOR), the performance of oil wells with different artificial lift pumping systems installed are directly affected by the presence of free gas in the fluid. As a result, pump volumetric efficiency decreases reducing production, affecting the life cycle of the pump, and increasing costs due to the need of rig intervention for installing gas separators, or different assemblies for gas handling devices such as charge, tapered or two stage pumps in order to improve this volumetric efficiency.
Two newer systems for handling gas at the surface have been applied in high GOR wells in the heavy and extra heavy oil wells of Eastern Venezuela. The first system consists of implementing a closed loop device for controlling the pressure of the annular of a well to an optimal pressure value. The control algorithm based on techniques from expert systems has been applied successfully in several wells. Basically, when the pressure of casing is being controlled by an automated pressure control valve set at an optimum value, it causes a variation of the dynamic fluids reducing the amount of free gas in the annular space and pump.
The second system consists of a PCP (progressive cavity pump) device that measures fluid load through a load cell installed at the drive head of the surface equipment and detect variation in dynamic fluid, torque and motor load and surface pressure of the flow line are also recorded, and adjust the velocity of the pump with the variable frequency drive controlled by an expert system, which runs in a programmable logic controller developed for optimizing PCP. All these two systems have improved production and run life in more than 20% in different wells in which have been evaluated.
Buckling Prevention Using the Tensioning Device
Authors: Langbauer Clemens , Chevelcha Elena , Hofstäetter Herbert 
Published: May 2013

Abstract
A large fraction of artificially produced oil from mature, almost depleted reservoirs is lifted with sucker rod pumps. To increase the oil recovery factor under profitable conditions the objective is to reduce the operational costs, consequently decreasing the required number of maintenances and interventions. An essential cause of failures within rod pumps is buckling of the sucker rod string which occurs if the compressive load in individual rods exceeds a critical value. It causes a reduction of the volumetric efficiency and an increase of erosion and corrosion. The meantime between failures (MTBF) is relatively low and expensive changes of the rod string are required.
This paper presents an approach to prevent buckling by tensioning the rod string during the whole pumping cycle with the tensioning device, which is integrated in the rod string below the pump plunger. In addition, an optimization of the tapered rod string is performed to reduce the mass of the reciprocating rod string. The system analysis is performed by a simulation of the downhole installation, which is verified by numerous dynamometer measurements, from the surface and downhole, of different operating oil wells. The result of the simulation is the distribution of the tension in the sucker rod string from the polished rod to the pump plunger. With this knowledge, a rod string with optimum usage of material strength and crosssections is designed.
The tensioning device was already tested in a sucker rod pumped oil well in Austria. The result was a saving of electrical energy costs for the driving unit, and reduced number of workover operations. The tensioning device is simple but efficient and can be used within each sucker rod pump application. It prevents the system from buckling with a minimum amount of investment.
Gas Lift Smart Flow Integrates Quality and Control Data for Diagnostic and Optimization in Real Time
Authors: Al-Jasmi A.. , Goel H. K. , Querales M.. , Lopez C.. , Carvajal G. A. , Moricca G.. , Vellani R.. , Villamizar M.. , Rodriguez J. A. , Velasquez G.. , Yong Z.. 
Published: May 2013

Abstract
Intelligent digital oilfield (iDOF) operations include the transfer, monitoring, visualization, analysis, and interpretation of realtime data. Enabling this process requires a significant investment in surface, subsurface, and well instrumentation and a sophisticated infrastructure for data transmission and visualization. This upgraded system can then transfer massive quantities of data. Automated intelligent workflows, referred to here as "smart flows", convert this raw data into real information at the right time.
To increase efficiency and decrease downtime in operations, oil companies have invested heavily in digital oilfield infrastructure. An important part of the puzzle is transferring data from the wellsite to the office in real time and using that data to optimize production systems. The challenge is to extract real-time information from raw data at the right time to affect the management of the fields, which is the primary goal.
North Kuwait’s Sabriyah field is operated using an intelligent digital oilfield operation by a major Middle Eastern oil company. Part of the intelligent digital oilfield project is a smart flow dedicated to monitoring, diagnostics, and optimization of gas lift (GL) wells. Leading-edge technologies—such as subsurface equipment and sensors, advanced diagnostics based on artificial intelligent agents, analysis of sensors signals, and automatically identifying GL optimum operating-conditions—are used to accomplish this goal.
Using a steady-state nodal-analysis model combined with an artificial intelligent technique, the smart flow is designed to provide rapid diagnostics and optimization in real time, generating actions, such as decreasing and increasing the gas lift injection rate and choke setting. The ultimate benefit is timely detection of those signals that foretell unexpected well downtime or equipment failure. The paper describes the main functionalities of the GL smart flow as a powerful optimization tool capable of providing an interactive monitoring system to assist the company in managing its GL-operated wells.
Optimizing an Artificially Lifted Reservoir using ESPs and Real Time Information
Authors: Paez Gerardo 
Published: May 2013

Abstract
Real time data is not a new concept to ESP lifted wells. Many systems are available to gather and transmit data, coupled with services and software to help analyses data. However, the potential value of real time surveillance systems is often not fully realized. This paper discusses case studies of how information from intelligent real time processes was used to optimize production, increase run life and manage ultimate production from the reservoir.
Each well was equipped with a panel running a real time nodal analysis well model which enabled the draw down on the reservoir to be controlled using the ESP. Target draw down or flow rate values where supplied to each processor which calculated the optimum mode of operation for the ESP. Techniques included virtual real time well testing, balancing of draw down on the reservoir in real time using the lift system as a control, and the importance of protecting the lifting equipment during the automation process.
Oil production gains ranging from 6 to 50% were achieved using the system, some of which occurring on wells thought to be previously optimized. ESP uptime was improved through real time monitoring of well status, and pump operation in difficult wells improved through use of the advanced ESP diagnostics information.
The novel architecture of the system showed that parallel processing power enabled each well to automatically adapt to changes in reservoir or flow line performances in real time as the target draw down values where achieved. Fine tuning of the lift system frequency (pump speed) and wellhead pressures allowed each well to be optimized in line with the reservoir engineers recommended bottom hole flowing pressure requests. The individual production and draw down targets could be adjusted up or down at the reservoir engineers request and the system automatically recalculate the optimum operating condition for the lift system.
The real time system showed how draw down targets could be adjusted to enhance overall production in addition to achieving the targets through real time automation of each ESPs operation
Wireless Simultaneous Acquisition and Analysis of Dynamometer and Fluid Level Data for Real-Time Monitoring of Well Performance
Authors: McCoy J.N.. N. , Becker Dieter , Fernandez Gustavo , Podio A. L. 
Published: May 2013

Abstract
Real time analysis and visualization of the performance of a rod pumped well are achieved using multiple small and compact wireless sensors that simultaneously transmit acquired data to a digital laptop manager that integrates the measurements, displays performance graphs and provides advanced tools for analysis and troubleshooting of the pumping system.
Battery powered wireless sensors for fluid level, pressure and dynamometer data acquisition are easily deployed and quickly installed on the well. The laptop manager automatically recognizes and commissions the sensors. The user sets up and controls the acquisition of data which may include multiple sensors that synchronously monitor variables such as tubing and casing pressures, fluid level and polished rod acceleration/position and load as a function of time. Elimination of cables and connectors improves the reliability of the hardware and data while speeding up the set-up-tear-down process. The user interface presents a smart instrument rather than a complex application.
Among the many innovations provided by these well performance analysis tools stand out the real time visualization of the operation and fluid distribution in the down-hole pump, the simultaneous display of quantitative surface and pump dynamometer graphs in conjunction with fluid level and wellbore pressures. Acquired data, wellbore description and pumping system characteristics are saved as a historical data base creating a continuum of the well’s information and performance for direct comparison and detailed analysis.
The paper describes the hardware and user interface, the procedures for installation and acquisition and several examples of field data and well performance analyses for a variety of rod pumping installations.
Implementation of New Seal Design to Improve ESP Performance in Corcel Field
Authors: Sarkis N.. , Guerra W.. , Moreno L. F. , Salazar I.. , Cuellar H.. , Pirela J.. , Urdaneta B.. 
Published: May 2013

Abstract
The main artificial lift method used in the field Corcel, located in the Llanos Basin, since its beginning in 2007, is the electric submersible pump (ESP). Until April 2011, 9 ESP units were running with an average run life of 218 days and, during those four (4) years, a total of 37 installations were performed, of which 21 were associated to ESP failures. As a result of the high number of failures and low run life presented, an interdisciplinary research group was created, including production, completion, reliability, product and applications engineers from Petrominerales and Baker Hughes, with the ultimate goal of increasing the life of the equipment, reducing intervention costs and minimizing deferred production.
Failure analysis focused on two main points: identification of the affected components and root cause of the failures. First results evidenced that the seal was the most affected component of the Electric Submersible Pump, and, more specifically, the elastomer bags and mechanical seals. Although the initial root cause of failure was not clear and was associated exclusively to a problem of compatibility between the seal elastomers and the well fluids, a further detailed analysis was performed to determine other possible failure mechanisms of this component.
This paper aims to describe and analyze the failure mechanisms, as well as to provide the solutions designed specifically to mitigate them, starting with the development of a new technology such as the SP1 seal to substantially improve the lifetime of the equipment. An illustration of one of the most important applications of fluid characterization for the sizing or selection of an ESP is presented, as well as the results in reduction of deferred production and intervention costs.
Development of a PCP Dynamic Safe Drive with Viscosity Super Brake and successful deployment in an Argentine Field
Authors: Young Esteban , Young Lucas , Sonsino Sergio , Bertomeu Fernando , Villota Daniel , Modon Alberto , Zubiri Juan , Pontelli Nicolas , Caunedo Carlos 
Published: May 2013

Abstract

Synopsis
The aim of this work is to present a PCP (Progressing Cavity Pumps) drive-head, which main feature is its dynamic viscous brake and its safe operation due to the lack of pulleys, belts and external mobile parts.
The drive-head was the result of 3 years of research and investigation in a joint effort between ITBA (University of applied sciences) and the service company. The final prototype after the development was installed at an operator’s well in April 2012, where it performed optimal. The results of the tests made during the prototype trial are shown in the present document.
The main conclusions after the trials are a shorter braking time with the viscous system, a safe operation and with a low maintenance level, an efficient rod string back spin control, and a quick oil production at surface at the well start up.