bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Simulation of Flow through a Perforation
Authors: Brooks James E. , Haggerty Dennis 
Published: June 2011

Abstract
API RP 19B Section 4 tests were established to evaluate perforator performance at field conditions. The question of how well such a small-scale laboratory test translates to downhole reality has long been raised. Furthermore, how accurately are downhole dynamics reproduced in single-shot, Section 4 tests, when in practice, an extensive formation is perforated with multiple shots?
To address this question, flow fields for typical axial and radial API Section 4 flow targets were calculated using a general analytical model based on potential theory and compared with the calculated results of various downhole configurations with different shot densities. When compared with calculations of downhole flow, we show that both radial and axial API targets can yield flow patterns that differ considerably from those downhole, which could lead to erroneous interpretations of results and dynamic effects, such as cleanup. As expected, results show that a radial flow target tends to overestimate the flow into a downhole perforation depending on the shot density and that an axial flow target tends to underestimate the flow depending on target length.
We discuss how to modify the API test core by attaching a low-permeability sleeve to create a more accurate downhole flow simulation. The result is a more representative test that better reproduces the initial static reservoir pressure and the post-shot flowing pressure.
To illustrate the concept, we made several tests using modified and unmodified axial flow targets to compare flow efficiency through perforations. Initial results indicate a difference in flow between the two sets of targets, with the modified targets having lower flow efficiency. Finally, we offer some possible physical reasons to explain the difference.
Phase Boundaries of Microemulsion Systems Help to Increase Productivity
Authors: Quintero Lirio , Jones Thomas A. , Pietrangeli Gianna 
Published: June 2011

Abstract
Formation damage may be caused by in-situ emulsions, changes in wettability and by deposition of asphaltenes, wax and scales. It is widely recognized that these damage mechanisms may be removed by using microemulsion technology, resulting in enhanced productivity of oil and gas wells. It is also known that microemulsion systems are composed of surfactants, oil, brine and optional co-surfactants and acids. These systems can be very complex, due to the number of variables that influence formulation behavior, including temperature, type of oil, type and concentration of salt, surfactant, co-surfactant, and acid.
The development of microemulsions for specific oilfield applications requires a systematic study of phase behavior as a tool to select a treatment composition that satisfies specific parameters defined by the application. Phase behavior studies are necessary in order to identify microemulsion phase boundaries.
Phase behavior diagrams of microemulsion systems developed for wellbore damage remediation considered the following variables: temperature, type and concentration of co-surfactants, type and concentration of brine, oils, surfactants and acids. Laboratory studies of surfactant-oil-brine systems used successfully in the field confirm that they undergo phase transitions from Winsor I (oil-in-water with excess oil), to Winsor III (microemulsion), to Winsor II (water-in-oil with excess water).
This paper presents formulations positioned in an area of the phase diagram that correspond to maximum detergency and optimum interfacial properties required for field applications. The relationship between phase diagrams, interfacial properties (interfacial tension and contact angle) and well productivity are discussed.
Crude Oil Compatibility Method Significantly Minimizes Volumes Required
Authors: Schultz Katrina , Javora Paul H. 
Published: June 2011

Abstract
Crude oil compatibility testing with completion brine is necessary to prevent the formation of crude oil-brine emulsions that cause formation damage and limit hydrocarbon production. Furthermore, required remedial action is costly. Conventional testing for the formation of oil-brine emulsions requires large volumes of oil, typically 50 to 75 mL oil for each test. Completion brine projects can require more than forty tests to identify adequately all fluid compatibility issues, which translates to about three liters of crude oil. However, high profile projects often deliver only limited quantities of crude oil, sometimes only 500 milliliters or less are available for emulsion testing.
To accommodate the growing demand for oil volume, researchers developed a new high-shear method and apparatus that uses a total per test volume of 10 milliliters, including crude oil and brine, fracturing gels, fluid loss control gels, broken gels, filtrates or stimulation fluids, and combinations thereof. With this methodology, a series of 40 crude oil compatibility tests requires only 200 mL of crude oil. The apparatus is constructed from common laboratory equipment and readily available devices. Markedly, the equipment delivers consistent high-shear mixing, clear visualization of fluid interfaces, capacity to stack three or more test fluids in a single test, and the ability to heat age samples to about 82°C (180°F).
Testing demonstrated that the new high-shear method and device produce reliable results using small volumes of crude oil and compare positively with conventional test methods. Since this method is applicable to all fluid-fluid testing, a proposal will be presented for inclusion into ISO-13503-3 (API RP-13J), Testing of heavy brines.
Measuring Fluid Placement of Sand-Consolidation Treatments Using DTS
Authors: Villesca Josue , Glasbergen Gerard , Attaway David 
Published: June 2011

Abstract
The successful application of sand-consolidation treatments is, for a major portion, dependent on correct fluid placement of the consolidation material. It is crucial to achieve a uniform placement of the material and, therefore, techniques are needed to overcome natural or artificially created heterogeneities. Diversion methods such as foams are being used frequently. However, fluid-placement verification of these treatments is rare.
This paper discusses the placement of a novel sand-consolidation material using a foam diverter and the verification of the placement by using distributed temperature sensing (DTS). Two case histories are analyzed in detail and used for illustration. In both case histories, foam was used to place the sand-consolidation material in multilayer reservoirs, and DTS was used to verify the placement in real-time. Qualitative and quantitative fluid placement information was derived in both cases.
From the DTS data, the parts of the formation that were treated could be identified in both case histories. In one case history, recently placed hydraulic fractures were identified and were treated. In the other case, reservoir-pressure variations were determined and identified to be the reason for preferential fluid placement and diversion over time. The lessons learned from the case histories will lead to further improvement of fluid placement.
Defective Differentiation of Regulatory FoxP3+ T Cells by Small-Intestinal Dendritic Cells in Patients With Type 1 Diabetes
Authors: Badami Ester , Sorini Chiara , Coccia Margherita , Usuelli Vera , Molteni Laura , Bolla Andrea Mario , Scavini Marina , Mariani Alberto , King Cecile , Bosi Emanuele , Falcone Marika 
Published: June 2011

OBJECTIVE
The gut environment modulates the pathogenesis of type 1 diabetes (T1D), but how it affects autoimmunity toward pancreatic β-cells, a self-tissue located outside the intestine, is still unclear. In the small intestine, lamina propria dendritic cells (LPDCs) induce peripheral differentiation of FoxP3+ regulatory T (Treg) cells. We tested the hypothesis that the intestinal milieu impinges on human T1D by affecting differentiation of FoxP3+ Treg cells.

RESEARCH DESIGN AND METHODS
We collected duodenal biopsies of 10 T1D patients, 16 healthy subjects, and 20 celiac individuals and performed a fluorescent-activated cell sorter analysis to measure percentages of various immune cell subsets, including CD4+ and CD8+ T cells, NK cells, γδ T cells, CD103+CD11c+ LPDCs, and CD4+CD25+FoxP3+CD127− Treg cells. In parallel, we assessed the tolerogenic function (i.e., capacity to induce differentiation of FoxP3+ Treg cells) by LPDCs of T1D patients and control subjects.

RESULTS
Our analysis revealed a significant reduction in the percentage of intestinal CD4+CD25+FoxP3+CD127− Treg cells in T1D patients compared with healthy subjects (P = 0.03) and celiac individuals (P = 0.003). In addition, we found that LPDCs from T1D patients completely lacked their tolerogenic function; they were unable to convert CD4+CD25− T cells into CD4+CD25+FoxP3+CD127− Treg cells.

CONCLUSIONS
Our data indicate that T1D patients have a reduced number of intestinal FoxP3+ Treg cells as a result of their defective differentiation in the gut. These findings suggest that intestinal immune regulation is not only calibrated to tolerate commensal bacteria and food components but also is instrumental in maintaining immune tolerance toward pancreatic β-cells and preventing T1D.
Tillage in Relation to Distribution of Nutrients and Organic Carbon in the Soil
Authors: Šoltysová Božena , Danilovič Martin 
Published: June 2011

Tillage in Relation to Distribution of Nutrients and Organic Carbon in the SoilChanges of total nitrogen, available phosphorus, available potassium and soil organic carbon were observed on gleyic Fluvisols (locality Milhostov) at the following crops: grain maize (2005), spring barley (2006), winter wheat (2007), soya (2008), grain maize (2009). The experiment was realized at three soil tillage technologies: conventional tillage, reduced tillage and no-tillage. Soil samples were collected from three depths (0-0.15 m; 0.15-0.30 m; 0.30-0.45 m). The ratio of soil organic carbon to total nitrogen was also calculated.Soil tillage affects significantly the content of total nitrogen in soil. The difference between the convetional tillage and soil protective tillages was significant. The balance showed that the content of total nitrogen decreased at reduced tillage by 5.2 rel.%, at no-tillage by 5.1 rel.% and at conventional tillage by 0.7 rel.%.Similarly, the content of organic matter in the soil was significantly affected by soil tillage. The content of soil organic carbon found at the end of the research period was lower by 4.1 rel.% at reduced tillage, by 4.8 rel.% at no-tillage and by 4.9 rel.% at conventional tillage compared with initial stage. The difference between the convetional tillage and soil protective tillages was significant.Less significant relationship was found between the soil tillage and the content of available phosphorus. The balance showed that the content of available phosphorus was increased at reduced tillage (by 4.1 rel.%) and was decreased at no-tillage (by 9.5 rel.%) and at conventional tillage (by 3.3 rel.%).Tillage did not significantly affect the content of available potassium in the soil.
Physical Game Demands in Elite Rugby Union: A Global Positioning System Analysis and Possible Implications for Rehabilitation
Authors: Coughlan Garrett F. , Green Brian S. , Pook Paul T. , Toolan Eoin , O'Connor Sean P. 
Published: June 2011

Study Design Descriptive. Objectives To evaluate the physical demands of an international Rugby Union-level game using a global positioning system (GPS). Background Elite Rugby Union teams currently employ the latest technology to monitor and evaluate physical demands of training and games on their players. Methods GPS data from 2 players, a back and a forward, were collected during an international Rugby Union game. Locomotion speed, total body load, and body load sustained in tackles and scrums were analyzed. Results Players completed an average distance of 6715 m and spent the major portion of the game standing or walking, interspersed with medium- and high-intensity running activities. The back performed a higher number of high-intensity sprints and reached a greater maximal speed. Body load data revealed that high levels of gravitational force are sustained in tackling and scrum tasks. Conclusion The current study provides a detailed GPS analysis of the physical demands of international Rugby Union players. These data, when combined with game video footage, may assist sports medicine professionals in understanding the demands of the game and mechanism of injury, as well as improving injury rehabilitation. J Orthop Sports Phys Ther 2011;41(8):600–605, Epub 7 June 2011. doi:10.2519/jospt.2011.3508
Factors Associated With Care Seeking From Physicians, Physical Therapists, or Chiropractors by Persons With Spinal Pain: A Population-Based Study
Authors: Chevan Julia , Riddle Daniel L. 
Published: June 2011

Study Design Secondary analysis of longitudinal population-based survey data. Objectives To investigate factors associated with care seeking for physician-referred physical therapy (MD/PT), as compared to physician-only (MD) or chiropractic-only (DC) care for spinal pain. Background Although a large proportion of ambulatory physical therapy visits are related to spinal pain, physical therapists are not the most commonly seen provider. The majority of visits are to physicians, followed by chiropractors. We attempted to understand more about this disparity by examining social and demographic factors that differentiate between persons who see these providers. Methods Episodes of care were constructed from participants in 2 panels from the Medical Expenditure Panel Survey who had spinal pain. The provider of care was identified for each episode, and logistic regression was used to determine factors associated with MD/PT use compared to MD use, and MD/PT use compared to DC use. Results The majority of patients (61%) received MD care for spinal pain, followed by those who received DC (28%) and MD/PT (11%) care. Female sex, higher levels of education, and higher income were significantly associated with MD/ PT care over MD care. Increased age, female sex, lower self-health rating, and presence of at least 1 disability day were all significantly associated with MD/PT care over DC care. Conclusion Sociodemographic and clinical factors are associated with those who get MD/PT care as compared to MD or DC care. We found evidence of an access disparity for physical therapy and identified population characteristics that both increase and reduce the likelihood of physical therapy service use. J Orthop Sports Phys Ther 2011;41(7):467–476, Epub 7 June 2011. doi:10.2519/jospt.2011.3637
Neuraminidase of 2007–2008 Influenza A(H1N1) Viruses Shows Increased Affinity for Sialic Acids Due to the D344N Substitution
Authors: Rameix-Welti Marie-Anne , Munier Sandie , Le Gal Sebastien , Cuvelier Frederique , Agou Fabrice , Enouf Vincent , Naffakh Nadia , van der Werf Sylvie 
Published: June 2011

Background During the 2007–2008 season, A(H1N1) viruses naturally resistant to oseltamivir due to an H275Y substitution in the neuraminidase emerged and spread in the human population. The neuraminidase of 2007–2008 A(H1N1) viruses has an increased affinity for sialic acids as compared with the N1 of previously circulating viruses. Methods Using site-directed mutagenesis analysis and an enzymatic assay on cells transiently expressing the viral neuraminidase, the amino acid changes that could account for the particular enzymatic properties of the neuraminidase of 2007–2008 A(H1N1) viruses were explored. The affinity for the substrate ( K m) and the inhibition constants for inhibitors ( K i) were determined for wild-type and mutated neuraminidases. Reverse genetics was used to produce 6:2 reassortant viruses expressing haemagglutinin and neuraminidase derived from A(H1N1) viruses of the 2007–2008 season or from a previously circulating H1N1 virus, in an A/WSN/33 background. Results The D344N substitution characteristic of the N1 of 2007–2008 A(H1N1) viruses was identified as a major determinant of its increased affinity for sialic acids. According to the viral plaque phenotype of the 6:2 reas-sortant viruses, the H275Y mutation was deleterious when the surface glycoproteins were derived from the H1N1 virus isolated in 2004, but not when they were derived from A(H1N1) viruses of the 2007–2008 season. Conclusions The D344N substitution, by modifying the enzymatic property of the N1, may have favoured the emergence and spread of viruses naturally resistant to oseltamivir.
Kit (W-sh) Mice Develop Earlier and More Severe Experimental Autoimmune Encephalomyelitis Due to Absence of Immune Suppression
Authors: Li Hongmei , Nourbakhsh Bardia , Safavi Farinaz , Li Ke , Xu Hui , Cullimore Melissa , Zhou Fang , Zhang Guangxian , Rostami Abdolmohamad 
Published: June 2011

Abstract
Mast cells (MCs) have been thought to play a pathogenic role in the development of autoimmune diseases, including experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, an immunoregulatory function of these cells has recently been suggested. We investigated the role of MCs in EAE using the W-sh mouse strain, which is MC deficient. W-sh mice developed earlier and more severe clinical and pathological disease with extensive demyelination and inflammation in the CNS. The inflammatory cells were mainly composed of CD4+ T cells, monocyte/macrophages, neutrophils, and dendritic cells. Compared with wild-type mice, MC-deficient mice exhibited an increased level of MCP-1/CCR2 and CD44 expression on CD4+ T cells in addition to decreased production of regulatory T cells, IL-4, IL-5, IL-27, and IL-10. We also found that levels of IL-17, IFN-γ, and GM-CSF were significantly increased in peripheral lymphocytes from immunized W-sh mice compared with those in peripheral lymphocytes from wild-type mice. Reconstitution of W-sh mice downregulated susceptibility to EAE, which correlated with MC recruitment and regulatory T cell activation in the CNS. These findings indicate that responsiveness is not required in the pathogenesis of inflammatory demyelination in the CNS and that, in the absence of MCs, increased MCP-1, CCR2, IL-17, IFN-γ, CD44, and other inflammatory molecules may be responsible for increased severity of EAE.
Antibodies to the Envelope Glycoprotein of Human T Cell Leukemia Virus Type 1 Robustly Activate Cell-Mediated Cytotoxic Responses and Directly Neutralize Viral Infectivity at Multiple Steps of the Entry Process
Authors: Kuo Chien-Wen S. , Mirsaliotis Antonis , Brighty David W. 
Published: June 2011

Abstract
Infection of human cells by human T cell leukemia virus type 1 (HTLV-1) is mediated by the viral envelope glycoproteins. The gp46 surface glycoprotein binds to cell surface receptors, including heparan sulfate proteoglycans, neuropilin 1, and glucose transporter 1, allowing the transmembrane glycoprotein to initiate fusion of the viral and cellular membranes. The envelope glycoproteins are recognized by neutralizing Abs and CTL following a protective immune response, and therefore, represent attractive components for a HTLV-1 vaccine. To begin to explore the immunological properties of potential envelope-based subunit vaccine candidates, we have used a soluble recombinant surface glycoprotein (gp46, SU) fused to the Fc region of human IgG (sRgp46-Fc) as an immunogen to vaccinate mice. The recombinant SU protein is highly immunogenic and induces high titer Ab responses, facilitating selection of hybridomas that secrete mAbs targeting SU. Many of these mAbs recognize envelope displayed on the surface of HTLV-1–infected cells and virions and several of the mAbs robustly antagonize envelope-mediated membrane fusion and neutralize pseudovirus infectivity. The most potently neutralizing mAbs recognize the N-terminal receptor-binding domain of SU, though there is considerable variation in neutralizing proficiency of the receptor-binding domain-targeted mAbs. By contrast, Abs targeting the C-terminal domain of SU tend to lack robust neutralizing activity. Importantly, we find that both neutralizing and poorly neutralizing Abs strongly stimulate neutrophil-mediated cytotoxic responses to HTLV-1–infected cells. Our data demonstrate that recombinant forms of SU possess immunological features that are of significant utility to subunit vaccine design.
The Parameter Averaging Technique in Finite-Difference Modeling of Elastic Waves in Combined Structures with Solid, Fluid and Porous Subregions
Authors: Guan Wei , Hu Hengshan 
Published: June 2011

AbstractTo finite-difference model elastic wave propagation in a combined structure with solid, fluid and porous subregions, a set of modified Biot’s equations are used, which can be reduced to the governing equations in solids, fluids as well as fluid-saturated porous media. Based on the modified Biot’s equations, the field quantities are finite-difference discretized into unified forms in the whole structure, including those on any interface between the solid, fluid and porous subregions. For the discrete equations on interfaces, however, the harmonic mean of shear modulus and the arithmetic mean of the other parameters on both sides of the interfaces are used. These parameter averaging equations are validated by deriving from the continuity conditions on the interfaces. As an example of using the parameter averaging technique, a 2-D finite-difference scheme with a velocity-stress staggered grid in cylindrical coordinates is implemented to simulate the acoustic logs in porous formations. The finite-difference simulations of the acoustic logging in a homogeneous formation agree well with those obtained by the analytical method. The acoustic logs with mud cakes clinging to the borehole well are simulated for investigating the effect of mud cake on the acoustic logs. The acoustic logs with a varying radius borehole embedded in a horizontally stratified formation are also simulated by using the proposed finite-difference scheme.
A Code that Simulates Fast-Ion Dα and Neutral Particle Measurements
Authors: Heidbrink W. W. , Liu D. , Luo Y. , Ruskov E. , Geiger B. 
Published: June 2011

AbstractA code that models signals produced by charge-exchange reactions between fast ions and injected neutral beams in tokamak plasmas is described. With the fast-ion distribution function as input, the code predicts the efflux to a neutral particle analyzer (NPA) diagnostic and the photon radiance of Balmer-alpha light to a fast-ion Dα (FIDA) diagnostic. Reactions with both the primary injected neutrals and with the cloud of secondary “halo” neutrals that surround the beam are treated. Accurate calculation of the fraction of neutrals that occupy excited atomic states (the collisional-radiative transition equations) is an important element of the code. Comparison with TRANSP output and other tests verify the solutions. Judicious selection of grid size and other parameters facilitate efficient solutions. The output of the code has been validated by FIDA measurements on DIII-D but further tests are warranted.