bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorescence microscope (Cyscope®) for malaria diagnosis in pregnant women in Medani Hospital, Sudan
Authors: Hassan Saad El-Din H , Haggaz Abd Elrahium D , Mohammed-Elhassan Ehab B , Malik Elfatih M , Adam Ishag 
Published: September 2011

Abstract

Background
Accuracy of diagnosis is the core for malaria control. Although microscopy is the gold standard in malaria diagnosis, its reliability is largely dependent on user skill. We compared performance of Cyscope® fluorescence microscope with the Giemsa stained light microscopy for the diagnosis of malaria among pregnant women at Medani Hospital in Central Sudan. The area is characterized by unstable malaria transmission.

Methods
Socio-demographic characteristics and obstetrics history were gathered using pre-tested questionnaires. Blood samples were collected from febrile pregnant women who were referred as malaria case following initial diagnosis by general microscopist.

Results
During the study period 128 febrile pregnant women presented at the hospital. Among them, Plasmodium falciparum malaria was detected in 82 (64.1%) and 80 (62.5%) by the Giemsa-stained light microscopy and the Cyscope® fluorescence microscope, respectively. The sensitivity of the Cyscope® fluorescence microscope was 97.6% (95% CI: 92.2%-99.6%). Out of 46 which were negative by Giemsa-stained light microscopy, 5 were positive by the Cyscope® fluorescence microscope. This is translated in specificity of 89.1% (95% CI: 77.5%-95.9%). The positive and negative predictive value of Cyscope® fluorescence microscope was 94.1% (95% CI: 87.4% -97.8%) and 95.3% (95% CI: 85.4% - 99.2%), respectively.

Conclusion
This study has shown that Cyscope® fluorescence microscope is a reliable diagnostic, sensitive and specific in diagnosing P. falciparum malaria among pregnant women in this setting. Further studies are needed to determine effectiveness in diagnosing other Plasmodium species and to compare it with other diagnostic tools e.g. rapid diagnostic tests and PCR.
Diagnosis of pericardial cysts using diffusion weighted magnetic resonance imaging: A case series
Authors: Raja Asam , Walker Jonathon R. , Sud Maneesh , Du Joe , Zeglinski Matthew , Czarnecki Andrew , Mousavi Negareh , Jassal Davinder S. , Kirkpatrick Iain D. C. 
Published: September 2011

Abstract

Introduction
Congenital pericardial cysts are benign lesions that arise from the pericardium during embryonic development. The diagnosis is based on typical imaging features, but atypical locations and signal magnetic resonance imaging sequences make it difficult to exclude other lesions. Diffusion-weighted magnetic resonance imaging is a novel method that can be used to differentiate tissues based on their restriction to proton diffusion. Its use in differentiating pericardial cysts from other pericardial lesions has not yet been described.

Case presentation
We present three cases (a 51-year-old Caucasian woman, a 66-year-old Caucasian woman and a 77-year-old Caucasian woman) with pericardial cysts evaluated with diffusion-weighted imaging using cardiac magnetic resonance imaging. Each lesion demonstrated a high apparent diffusion coefficient similar to that of free water.

Conclusion
This case series is the first attempt to investigate the utility of diffusion-weighted magnetic resonance imaging in the assessment of pericardial cysts. Diffusion-weighted imaging may be a useful noninvasive diagnostic tool for pericardial cysts when conventional imaging findings are inconclusive.
Genetic ancestry, skin reflectance and pigmentation genotypes in association with serum vitamin D metabolite balance
Authors: Wilson Robin Taylor , Roff Alanna N. , Dai P. Jenny , Fortugno Tracey , Douds Jonathan , Chen Gang , Grove Gary L. , Nikiforova Sheila Ongeri , Barnholtz-Sloan Jill , Frudakis Tony , Chinchilli Vernon M. , Hartman Terryl J. , Demers Laurence M. , Shriver Mark D. , Canfield Victor A. , Cheng Keith C. 
Published: September 2011

Abstract

Background: Lower serum vitamin D (25(OH)D) among individuals with African ancestry is primarily attributed to skin pigmentation. However, the influence of genetic polymorphisms controlling for skin melanin content has not been investigated. Therefore, we investigated differences in non-summer serum vitamin D metabolites according to self-reported race, genetic ancestry, skin reflectance and key pigmentation genes (SLC45A2 and SLC24A5).

Materials and methods: Healthy individuals reporting at least half African American or half European American heritage were frequency matched to one another on age (±2 years) and sex. One hundred and seventy-six autosomal ancestry informative markers were used to estimate genetic ancestry. Melanin index was measured by reflectance spectrometry. Serum vitamin D metabolites [25(OH)D3, 25(OH)D
2
and 24,25(OH)2D3] were determined by high performance liquid chromatography (HPLC) tandem mass spectrometry. Percent 24,25(OH)2D3 was calculated as a percent of the parent metabolite [25(OH)D3]. Stepwise and backward selection regression models were used to identify leading covariates.

Results: Fifty African Americans and 50 European Americans participated in the study. Compared with SLC24A5 111Thr homozygotes, individuals with the SLC24A5 111Thr/Ala and 111Ala/Ala genotypes had, respectively, lower levels of 25(OH)D3 (23.0 and 23.8 nmol/L lower, p-dominant=0.007), and percent 24,25(OH)2D3 (4.1% and 5.2% lower, p-dominant=0.003), controlling for tanning bed use, vitamin D/fish oil supplement intake, race/ethnicity and genetic ancestry. Results were similar with melanin index adjustment, and were not confounded by glucocorticoid, oral contraceptive, or statin use.

Conclusions: The SLC24A5 111Ala allele was associated with lower serum vitamin 25(OH)D3 and lower percent 24,25(OH)2D3, independently from melanin index and West African genetic ancestry.
Discontinuing Bevacizumab in Patients with Glioblastoma: An Ethical Analysis
Authors: Kesselheim Jennifer C. , Norden Andrew D. , Wen Patrick Y. , Joffe Steven 
Published: September 2011

Abstract

Learning Objectives
After completing this course, the reader will be able to: Explain the considerations of beneficence, nonmaleficence, autonomy, and justice necessary to the care and counseling of patients with glioblastoma receiving treatment with bevacizumab.Identify the ethical issues inherent to bevacizumab discontinuation in patients with glioblastoma whose tumors have progressed on the drug.
CME This article is available for continuing medical education credit at CME.TheOncologist.com
Glioblastoma (GBM) is a highly lethal malignant brain tumor that expresses proangiogenic factors, including vascular endothelial growth factor (VEGF). Bevacizumab (Avastin®; Genentech, Inc., South San Francisco, CA), a monoclonal antibody against VEGF, is routinely used in the U.S. to treat GBM patients whose tumors have progressed following initial therapy. The Ethics Advisory Committee at the Dana-Farber Cancer Institute was asked to provide consultation on two cases involving patients with recurrent GBM who were receiving bevacizumab. Despite evidence of disease progression, family members advocated for the continued use of bevacizumab because of its mild toxicity profile and concern that discontinuation would impair quality of life. However, continuing bevacizumab in this setting posed physical and financial risks to the patients and raised ethical concerns about resource allocation and justice.
We analyze the ethical questions regarding bevacizumab discontinuation in the setting of progressive GBM. We articulate the potential benefits and harms of continuing the drug and identify guiding principles for drug discontinuation that should be made transparent to patients and families. With the increasing availability of new, modestly toxic, expensive drugs for patients with advanced cancer, questions of when to stop these drugs will become increasingly relevant.
Revisiting the Role of Antiandrogen Strategies in Ovarian Cancer
Authors: Papadatos-Pastos Dionysis , Dedes Konstantin J. , de Bono Johann S. , Kaye Stanley B. 
Published: September 2011

AbstractLearning ObjectivesAfter completing this course, the reader will be able to: Explain the role of the androgen axis in the development of ovarian cancer.Discuss the potential compounds with anti-androgen activity that can be assessed for the treatment of patients with ovarian cancer.CME This article is available for continuing medical education credit at CME.TheOncologist.comAndrogen receptors are frequently expressed in epithelial ovarian cancer (EOC). Their role in the development of EOC is not fully understood. In the present review we first discuss the epidemiological data linking a hyperandrogen state to a higher risk for ovarian cancer, second describe in vitro studies of the role of androgens in influencing the growth of EOC, and finally review the completed clinical trials with compounds that exploit the androgen axis in patients with ovarian cancer. The therapeutic approaches that inhibit androgen signaling have so far produced only modest response rates. In the light of new data regarding the role of androgen stimulation in the evolution of EOC and the emergence of new compounds used for the treatment of other hormone-driven malignancies, such as prostate and breast cancer, we provide suggestions for new studies of antiandrogen therapeutics in the treatment of EOC. A specific example is the new agent abiraterone. In addition, we propose a panel of molecules that could be assessed as potential biomarkers that may aid patient selection for this approach in the future.
Maximizing ESP Run Time Through Synchronization of Generator Sets
Authors: Al-Aslawi Raed , Al-Haimer Mohammad , Al-Sharqawi Anwar , Zahedi Alireza , Al-Najim Abdulaziz , Al-Khonaini Talal 
Published: September 2011

Abstract
The South Fuwaris and Humma Fields are located in the Partitioned Zone between Kuwait and Saudi Arabia. The South Fuwaris Field commenced production in 1963, with the majority of its production from the Lower Cretaceous Ratawi Limestone/Oolite reservoir. The Humma Field was discovered in 1998, and has the only PZ production from the early Jurassic Marrat Formation. 95% of the wells in South Fuwaris and Humma produce via electrical submersible pumps (ESP).
The remote location of both fields requires all ESP systems to be powered by individual diesel generator sets located close to the well heads. Based on the requirements of the preventive maintenance program for these generators, each generator set is scheduled for lube oil/filter change every two weeks, at which time production is shut-in. The shut-ins result in a considerable volume of deferred oil.
A recent Root Cause Analysis study of the historical failures of the downhole production assemblies of ESP-equipped South Fuwaris and Humma producers revealed that a significant number of failures could be directly or indirectly attributed to the produced solids settling back into the ESP after shutdown. When the well is shut down, the fluid column above the ESP drains back into the wellbore through the pump, causing produced solids to be deposited in the ESP. This causes high current draw during start up and eventually leads to motor or cable failure, in many cases resulting in complete seizure of the ESP shaft.
To avoid the production loss and ESP failures that result from well shut in, the asset management teams in South Fuwaris and Humma have developed a method for keeping wells on line while generator sets undergo lube oil/filter change.
The purpose of this paper is to demonstrate how the downhole ESP is kept running while its power generator undergoes scheduled preventive maintenance work. The paper also demonstrates the in-field applicability of the generator set synchronization technique to the oilfield operations, and how this technique has maximized ESP run time in Humma and South Fuwaris Fields, saving Wafra Joint operations greater than $10 MM annually. As more new wells are being drilled and produced, the annual dollar savings increase even further, through the use of a simple and cost-effective process.
Sandstone Acidizing Using A New Class of Chelating Agents
Authors: Mahmoud M. A. , Nasr-El-Din H. A. , De Wolf C. A. , Alex A. K. 
Published: September 2011

Abstract
The objective of stimulation of sandstone reservoirs is to remove the damage caused to the production zone during drilling or completion operations. Many problems may occur during sandstone acidizing with HCl/HF mud acid. Among these problems: decomposition of clays in HCl acids, precipitation of fluosilicates, the presence of carbonates can cause the precipitation of calcium fluorides, silica-gel filming, colloidal silica-gel precipitation.
In this study, a recently introduced chelating agent, glutami-N, N-diacetic acid(GLDA), was used to stimulate sandstone cores. Berea sandstone cores with 8 wt% clays content were used in this study. Different GLDA solution pH values (1.7 - 13) were used in the coreflood experiments. The sandstone cores were scanned before and after the treatment to investigate the effect of GLDA on the core. The effluent samples were analyzed for calcium, magnesium, aluminum, and iron using the ICP to assess the ability of GLDA on the complexation of these ions. Coreflood experiments were run at temperatures of 200 to 300°F and the concentration of GLDA was determined after the treatment. The effects of injection rate, volume of GLDA, temperature, and GLDA initial pH value were investigated on the Berea sandstone cores in the coreflood experiments. Different correlations were used to determine the core permeability after the treatment, and the correlation that gave the minimum error was determined.
GLDA showed a strong ability in chelating calcium, iron, magnesium, and it chelated small amounts of aluminum ions from the sandstone cores. At 300°F, GLDA at different pH values was able to enhance the core permeability. Decreasing the injection rate from 5 to 2 cm3/min increased the contact time between the fluid and the rock and increased the amount of dissolved ions. X-ray CT scan showed a porosity increase after the treatments at different conditions. The concentration of GLDA after the coreflood experiment was almost the same before the treatment showing a high thermal stability up to 300°F in the coreflood experiment. Labrid was found to be the best correlation to predict for the core permeability after treating Berea sandstone cores by 20 wt% GLDA solutions.
From Volumetric Energy Balance to the Entropy Generation: The Evolution of the State of the Art in Thermodynamic Concepts in Petroleum Production Systems
Authors: Tillero E. J. , Machado F. , Romero D. 
Published: September 2011

Abstract
The purpose of this study is to review the applications of laws of thermodynamic in petroleum system, and how it may be lead to optimum operating conditions and miximize substantially the ultimate hydrocarbon recovery, optimizing at the same time the reservoir energy utilization.
In this paper is shown how thermodynamic concepts such as energy, efficiency, availability function, useful work, and entropy generation were introduced in petroleum engineering to explain losses of fluid energy due to reservoir exploitation.
It was remarked that a proper management of variables such as production or injection rate, wellbore vicinity condition (skin factor), number of wells and their locations, locations of surface facilities, reservoir driving mechanisms, and improved hydrocarbon recovery techniques, all of them from a thermodynamic point of view, should be considered if both the reservoir energy efficiency and its sustentability are a must.
More valuable applications may be extended from the concept of entropy generation, such as its inclusion in reservoir simulation as a post-processing calculus, in order to generate and compare multiple realizations for seeking an optimum operating condition, and maximizing hydrocarbon recovery at the scenario of minimum irreversibility.
Fully Miscible Micellar Acidizing Solvents vs. Xylene, The Better Paraffin Solution
Authors: Boswood David W. , Kreh Kristopher A. 
Published: September 2011

Abstract
Organic deposits such as paraffin have long been an issue in many oil-producing wells throughout the world. These deposits have been treated for years with solvent chemicals such as xylene. Although xylene is quite effective at dissolving and removing paraffin, it is not easily miscible in most acid treatments, and it is extremely flammable. These two issues together make xylene a dangerous choice for paraffin removal.
Fully miscible micellar acidizing solvents can solve paraffin problems more safely and effectively. These micellar acidizing solvents are less flammable, solubilize heavy hydrocarbons, reduce surface tension to remove water blocks, water wet formation matrix and are fully miscible in acid systems. Because they are fully miscible in acid systems, stimulation operations can achieve performance goals with much lower volumes of acidizing solvents.
This paper will take a detailed look at the causes of paraffin deposition and will explain how xylene and fully miscible micellar acidizing solvents dissolve paraffin deposits. It will also compare the benefits and challenges associated with each system. Case study and lab test data will be presented to compare the performance and the economics of both systems.
HCl-Formic In-Situ Gelled Acid for Carbonate Acidizing: Core Flood and Reaction Rate Study
Authors: Rabie Ahmed I. , Gomaa Ahmed M. , Nasr-El-Din Hisham A. 
Published: September 2011

Abstract
Hydrochloric acid has been extensively used for well stimulation in matrix acidizing and acid fracturing. However, high reaction rate and severity of corrosion problems, especially for wells completed with Cr-based tubulars, limit the usage of the straight acid, especially for deep gas reservoirs. In-situ gelled acids are used to reduce leak-off rate and enhance acid diversion, while mixing organic acids with regular hydrochloric acid reduces the strength of HCl and increases the acid penetration. Literature review shows that very few numbers of studies have addressed the systems that utilize both advantages.
The objective of this work is to investigate the effect of formic acid on the performance of the live and the spent in-situ gelled formic-HCl through viscosity measurements and core flood studies and to measure the rate of reaction of different formic-HCl in-situ gelled acid mixtures with calcite. Pink Desert limestone was utilized for the core flood and the reaction rate experiments. The core flood study was conducted at 250°F using two different rates of injection (2 and 10 cm3/min) and the rotating disk reactor was used to perform the reaction rate study. The effect of formic acid concentration, disk rotational speed, and zirconium cross-linking additive on the reaction rate was examined at 250°F. The formic acid concentration ranged from 0 to 6.31 wt% and the HCl concentration ranged from 0 to 5 wt.%.
The core flood results showed that in this acid concentration range with the selected polymer and zirconium cross linking agent, the in-situ formic-HCl acid is behaving more like gelled acid. Increasing the formic acid concentration decreases the reaction rate with calcite at both low and high disk rotational speed. This was confirmed by the viscosity measurements, which showed that increasing the formic acid concentration increased the live acid viscosity and decreased the viscosity of the spent acid.
Effects of Injected Water Chemistry on Waterflood Sweep Efficiency via Induced Fines Migration
Authors: Lemon Phillip , Zeinijahromi Abbas , Bedrikovetsky Pavel , Shahin Ibrahim 
Published: September 2011

Abstract
Permeability decline during corefloods with varying water composition, especially with low salinity water, has been observed in numerous laboratory studies. It has often been explained by the lifting, migration and subsequent plugging of pores by fine particles, which have been observed in numerous core flood tests with altered water composition. In this work, the concept that this permeability decline may be used for mobility control during waterflooding was investigated. The Dietz model for waterflooding in a layer cake reservoir with a constant injection and production rate was combined with a particle detachment model to provide a simple analytical model for the process. The application of the model to an example data set showed induced fines migration may improve sweep efficiency for a given volume of injected water.
Improved Drilling Economics and Enhanced Target Acquisition through the Application of Effective Geomagnetic Referencing
Authors: Poedjono Benny , Olalere Ismail Bolaji , Shevchenko Irina , Lawson Fraser , Crozier Steve , Li Xiong 
Published: September 2011

Abstract
For a deepwater operator facing the challenges of directional drilling and wellbore stability, surveying with high spread costs in excess of USD 1 million per day, any approach which promises to reduce or eliminate cost and risk has great potential benefit. This paper showcases how careful planning, a fit-for-purpose survey program, and, most importantly, an effective, real-time geomagnetic referencing service (GRS) can significantly improve the operator's ability to hit both geological and financial targets. The authors describe recent breakthrough improvements in the accuracy of GRS techniques and present a case study to illustrate the benefits of this approach for the industry, especially in deepwater operations.
Each magnetic survey tool has an associated degree of uncertainty in the accuracy of data acquired. This error is cumulative, increasing with depth as a well is being drilled. In three dimensions, this area of uncertainty takes an elliptical form around the projected well path, a zone of possible well positions known as the ellipse of uncertainty (EOU). In high-angle wells, the EOU may grow so large that it exceeds the dimensions of the geological target, decreasing the driller's level of confidence and increasing the risks and potential costs of missing the target. Therefore, the development of more accurate yet cost-effective surveying techniques has become increasingly critical.
The authors will describe a survey approach that meets this challenge by incorporating breakthroughs in real-time GRS and which offers the producer the following benefits: Achieving planned geological targetsSaving the cost of running gyroscopic surveysAvoiding costly post-gyro well path corrections by staying on-path in real timePreventing stuck pipe, lost time, and other risks often associated with gyro surveys
The example case to be discussed illustrates how to realize all of the above benefits.