bluuebunny/crossref_metadata_2025_split huggingface dataset:
First-Pass Screening of Reservoirs with Large Gas Caps for Oil Rim Development
Authors: Olamigoke Olugbenga , Peacock Anthony 
Published: December 2009

Abstract
Many gas reservoirs critical to providing a reliable supply of gas to the Nigeria Gas market have observed or potential oil rims where only a gas-down-to (GDT) has been logged. Development of these oil rims must be considered as part of the overall hydrocarbon maturation plans for the reservoir. Maturation studies of this type can take a long time and may lead to restrictions on the availability (quantity and timing) of the gas volumes to the market. This poses a serious challenge to maintaining gas supply and meeting contractual obligations.
Field performance of selected oil rim reservoirs in the Niger Delta have been analysed and presented in this work. The main factors that influence oil rim performance are highlighted and oil recovery trends have been established.
In addition, a generic simulation model has also been developed to analyse oil rim dynamics and assess the impact on oil and gas recovery for a range of sub-surface uncertainties. A range of alternate development strategies has been considered. Experimental design was used to obtain oil recovery correlations for each development strategy which has proven to be a useful first pass screening tool to make assessments of the likely oil recovery range from a specific oil rim reservoir. The oil recovery trends obtained from the simulation study have been found to be consistent with actual oil rim performance.
The result of this work is therefore useful for quick screening of oil rims for technical and economic feasibility to support key business decisions before embarking on costly detailed studies, if eventually required, subject to the complexity of the situation and decision required.
Maximising Production in Non-Mandrel Wells by the Insert Orifice Case Specific Design Approach - Case Histories
Authors: Afolabi Folorunso , Olayemi Sarah , Avre Paul , Iwuh Virgil , Iwuogu Augustine , Ekong Inem , Dennar Linda 
Published: December 2009

Abstract
Shell Petroleum Dev. Coy. onshore wells in Nigeria are from brown fields producing since 1960. The fields have about 300 flowing strings. The fields are characterized by various challenges including depleted reservoir pressures, some non-mandrel wells, single and dual string completion with or without sand control, old tubulars and low remaining oil reserves. The crude is medium to high API gravity, all ranges of viscosity and produced with high water cut in some cases.
These wells completed without mandrels were either not flowing because of one or a combination of 1) formation damage problems 2) vertical lift problems due to depleted reservoir pressures and increasing water cut and 3) high pressure drop across flow lines in wells far from the flow stations. Distance becomes a significant factor especially with remote manifold wells that also suffer high backpressures from healthy common manifold wells. The predominant damage mechanisms in these wells are fines migration, clay swelling, wettability changes, water block, inorganic and organic scale deposition.
Restoring the productivity of non-mandrel wells with vertical lift problems or insufficient energy to reach flow stations with the aid of artificial lift methods (gaslift being the most accessible and cheapest option) in these fields would normally require a workover rig. Wells were worked over and re-completed with gaslift mandrels when significant reserves still existed. An expensive uneconomical option in these brown fields with dwindling reserves. The alternative, which is the rimless pack-off mandrel or insert orifice, has not only been found economical but also a technically less risky and skilful approach to introduce gaslift assistance. At the onset of the introduction of the insert orifice technology in the fields, engineers were faced with the challenge of determining the best position in the tubing for inserting the gas lift orifice in order to maximize reserves recovery. Using the poor boy approach of creating an inlet for gaslift into the production tubing easily became a short term and un-sustained success.
The case specific insert orifice design was applied in old non-mandrel wells with single and dual string completions, with or with sand control in depleted reservoirs and with low remaining oil reserves. The results so far have been 100 percent success in production increase and reserves addition. 11 strings have been successfully put on gaslift using the case specific design insert orifice method. These wells have delivered over 3.3MMstb of oil at a low average Unit Technical Cost of ca. 0.8$/bbl. The approach has saved the company the high cost of workover operations that would otherwise have been required, increased ultimate recovery and also improved the insert orifice gas lift design in general.
Corneal Molecular and Cellular Biology Update for the Refractive Surgeon
Authors: Salomao Marcella Q. , Wilson Steven E. 
Published: December 2009

Purpose:To review clinically relevant progress in understanding cellular and molecular interactions in the cornea that relate to refractive surgical outcomes in patients.Methods:Recent published literature focused on femtosecond LASIK and surface ablation procedures, such as photorefractive keratectomy, was reviewed and correlated with clinical results of surgery.Results:The femtosecond laser has a direct necrotic effect on stromal keratocytes, resulting in the release of cellular components that are chemotactic to bone marrow–derived inflammatory cells. Developments of the femtosecond laser led to lower energy delivery to the stroma and altered laser ablation profiles that decrease epithelial damage during the side-cut, and have markedly improved femtosecond LASIK to the point that the overall early postoperative healing response is indistinguishable from microkeratome LASIK. New studies have directly demonstrated the importance of surface irregularity and resulting structural and functional defects in the epithelial basement membrane, in the generation and persistence of anterior stromal myofibroblasts and haze following surface ablation procedures. These defects augment penetration of epithelium-derived TGF-β, which is a critical modulator of myofibroblast development in the stroma. Studies on the mechanism of action of mitomycin C treatment to prevent haze have confirmed that the most powerful effect is on stromal cell proliferation and, therefore, decreased population of the anterior stroma with myofibroblast progenitor cells. An undesirable long-term effect of mitomycin C is diminished anterior stromal keratocyte density due to diminished keratocyte re-population. This raises concerns regarding future corneal anomalies in treated corneas.Conclusions:Basic research studies of refractive procedures provide important insights into the effects of wound healing on surgical outcomes. [J Refract Surg.2009;25:459–466.]
Optical Performance in ReZoom and Array Multifocal Intraocular Lenses In Vitro
Authors: Kawamorita Takushi , Uozato Hiroshi , Aizawa Daisuke , Kamiya Kazutaka , Shimizu Kimiya 
Published: December 2009

Purpose:
To investigate the modulation transfer function (MTF) of two refractive multifocal intraocular lenses (IOLs).

Methods:
The ReZoom and Array (AMO) multifocal IOLs were evaluated using the OPAL Vector system (Image Science Ltd) and a model eye with a variable aperture (2.1 to 5.5 mm). Modulation transfer functions were evaluated at distant, near, and intermediate (−1.50 diopter defocus) focus lengths.

Results:
The ReZoom IOL distant focus MTF for a 5.1-mm effective diameter was higher than that of the Array IOL. At intermediate distance, the ReZoom lens showed a slight increase compared with the Array. The near focus MTF for the ReZoom IOL began to increase at an effective diameter of 2.1 mm and remained constant for diameters >3.45 mm.

Conclusions:

The ReZoom IOL gave better image quality than the Array, particularly at distant focus. To enhance near vision with the ReZoom lens, the desirable real pupil diameter should be at least 3.45 mm. [
J Refract Surg.
2009;25:467–469.]
Wavefront-guided Photorefractive Keratectomy After Radial Keratotomy in Nine Eyes
Authors: Myrowitz Elliott H. , Kurwa Ambereen , Parker Jack , Chuck Roy S. 
Published: December 2009

Purpose:
To investigate the refractive outcomes of wavefront-guided photorefractive keratectomy (PRK) in patients with previous radial keratotomy (RK).

Methods:
This study is a retrospective review of consecutive cases from August 2004 until February 2007 of PRK after RK. The VISX STAR S4 excimer laser was used. Visual acuity, manifest refraction, and slit-lamp microscopy were reviewed preoperatively and 3 and 12 months postoperatively.

Results:
Nine eyes, five hyperopic and four myopic, of six consecutively treated patients were evaluated. Myopic spherical equivalent refractive treatments averaged −2.08 diopters (D) (range: −0.80 to −3.36 D) and hyperopic treatments averaged +2.20 D (range: +1.28 to +3.12 D). No eyes lost any lines of Snellen best spectacle-corrected visual acuity (BSCVA) and three (33%) eyes gained one line of BSCVA. Two (22%) eyes showed grade 0.5 level haze (not in the visual axis) and the remaining seven eyes showed no haze. Seven (77%) of nine eyes were within ±0.25 D of the targeted spherical equivalent refraction at 3 months postoperative. Six (66%) of nine eyes had ⩾±0.50 D (range: +0.50 to +2.25) of astigmatism prior to PRK and all astigmatic errors were significantly reduced, with the highest residual astigmatic error of 0.75 D in one eye and 0.50 D in two eyes.

Conclusions:

Wavefront-guided PRK after RK for myopic, hyperopic, and astigmatic refractive errors targeting emmetropia in six eyes and myopia in three eyes yielded accurate refractive outcomes in this consecutive series. Three (33%) of nine eyes gained one line of BSCVA with no eyes losing BSCVA. Seven of nine eyes were within ±0.25 D of targeted spherical equivalent refraction at 3 months postoperative. [
J Refract Surg
. 2009;25:470–472.]
Development of Murine Lupus Involves the Combined Genetic Contribution of the SLAM and FcγR Intervals within the Nba2 Autoimmune Susceptibility Locus
Authors: Jørgensen Trine N. , Alfaro Jennifer , Enriquez Hilda L. , Jiang Chao , Loo William M. , Atencio Stephanie , Bupp Melanie R. Gubbels , Mailloux Christina M. , Metzger Troy , Flannery Shannon , Rozzo Stephen J. , Kotzin Brian L. , Rosemblatt Mario , Bono María Rosa , Erickson Loren D. 
Published: December 2009

Abstract
Autoantibodies are of central importance in the pathogenesis of Ab-mediated autoimmune disorders. The murine lupus susceptibility locus Nba2 on chromosome 1 and the syntenic human locus are associated with a loss of immune tolerance that leads to antinuclear Ab production. To identify gene intervals within Nba2 that control the development of autoantibody-producing B cells and to determine the cellular components through which Nba2 genes accomplish this, we generated congenic mice expressing various Nba2 intervals where genes for the FcγR, SLAM, and IFN-inducible families are encoded. Analysis of congenic strains demonstrated that the FcγR and SLAM intervals independently controlled the severity of autoantibody production and renal disease, yet are both required for lupus susceptibility. Deregulated homeostasis of terminally differentiated B cells was found to be controlled by the FcγR interval where FcγRIIb-mediated apoptosis of germinal center B cells and plasma cells was impaired. Increased numbers of activated plasmacytoid dendritic cells that were distinctly CD19+ and promoted plasma cell differentiation via the proinflammatory cytokines IL-10 and IFNα were linked to the SLAM interval. These findings suggest that SLAM and FcγR intervals act cooperatively to influence the clinical course of disease through supporting the differentiation and survival of autoantibody-producing cells.
Peroxiredoxin 1 Stimulates Secretion of Proinflammatory Cytokines by Binding to TLR4
Authors: Riddell Jonah R. , Wang Xiang-Yang , Minderman Hans , Gollnick Sandra O. 
Published: December 2009

Abstract
Peroxiredoxin 1 (Prx1) is an antioxidant and molecular chaperone that can be secreted from tumor cells. Prx1 is overexpressed in many cancers, and elevation of Prx1 is associated with poor clinical outcome. In the current study, we demonstrate that incubation of Prx1 with thioglycollate-elicited murine macrophages or immature bone marrow-derived dendritic cells resulted in TLR4-dependent secretion of TNF-α and IL-6 and dendritic cell maturation. Optimal secretion of cytokines in response to Prx1 was dependent upon serum and required CD14 and MD2. Binding of Prx1 to thioglycollate macrophages occurred within minutes and resulted in TLR4 endocytosis. Prx1 interaction with TLR4 was independent of its peroxidase activity and appeared to be dependent on its chaperone activity and ability to form decamers. Cytokine expression occurred via the TLR-MyD88 signaling pathway, which resulted in nuclear translocation and activation of NF-κB. These findings suggest that Prx1 may act as danger signal similar to other TLR4-binding chaperone molecules such as HSP72.
Gene Expression Analysis of Macrophages That Facilitate Tumor Invasion Supports a Role for Wnt-Signaling in Mediating Their Activity in Primary Mammary Tumors
Authors: Ojalvo Laureen S. , Whittaker Charles A. , Condeelis John S. , Pollard Jeffrey W. 
Published: December 2009

AbstractThe tumor microenvironment modifies the malignancy of tumors. In solid tumors, this environment is populated by many macrophages that, in genetic studies that depleted these cells from mouse models of breast cancer, were shown to promote tumor progression to malignancy and increase metastatic potential. Mechanistic studies showed that these tumor-promoting effects of macrophages are through the stimulation of tumor cell migration, invasion, intravasation, and enhancement of angiogenesis. Using an in vivo invasion assay, it was demonstrated that invasive carcinoma cells are a unique subpopulation of tumor cells whose invasion and chemotaxis is dependent on the comigration of tumor-associated macrophages (TAMs) with obligate reciprocal signaling through an epidermal growth factor–CSF-1 paracrine loop. In this study, these invasion-promoting macrophages were isolated and subjected to analysis of their transcriptome in comparison with TAMs isolated indiscriminately to function using established macrophage markers. Unsupervised analysis of transcript patterns showed that the invasion-associated TAMs represent a unique subpopulation of TAMs that, by gene ontology criteria, have gene expression patterns related to tissue and organ development. Gene set enrichment analysis showed that these macrophages are also specifically enriched for molecules involved in Wnt-signaling. Previously, it was shown that macrophage-derived Wnt molecules promote vascular remodeling and that tumor cells are highly motile and intravasate around perivascular TAM clusters. Taken together, we conjecture that invasive TAMs link angiogenesis and tumor invasion and that Wnt-signaling plays a role in mediating their activity.
Translational Components in Prokaryotes: Genetics and Regulation of Ribosomes
Authors: Wagner Rolf 
Published: December 2009

Abstract

The regulation of the biosynthesis of ribosomes, which constitute the catalytic organelles for the translation reaction, is central for the adaptation of bacteria to different growth conditions. The synthesis of the different ribosomal
ribonucleic acid
(rRNA) and ribosomal protein (RP) components is controlled and coordinated by a complex network of regulatory mechanisms to adjust the translational capacity to the required cell demands. Regulation of rRNA transcription plays a key role in ribosome formation. Quality control steps are operated during processing and assembly to ensure functionally competent particles and to avoid the accumulation of defective products and waste of energy and resources.

Key concepts:

Bacterial growth rates depend on the number of ribosomes.

Ribosome synthesis is adapted to environmental changes.

Biosynthesis of ribosomes involves quality control steps.

Ribosome synthesis is determined by the rate of rRNA transcription.

Synthesis of many ribosomal proteins is adjusted to the amount of free rRNA by a translational feedback mechanism.

Many ribosomal proteins have extra‐ribosomal functions in the cell.

A limited number of sequence heterogeneities in the redundantly encoded rRNA genes provide the potential for the formation of specialized ribosomes.

The stringent control is one of the major mechanisms for the adaptation of ribosomes in response to nutritional changes.
DNAInterstrand Crosslink Repair
Authors: Siede Wolfram 
Published: December 2009

AbstractCrosslinking agents such as psoralens, nitrogen mustards or cisplatin are bifunctionally acting chemicals that generate a fraction of their adducts as covalent linkages between complementary deoxyribonucleic acid strands. Since many of these agents are of importance in genetic toxicology and cancer therapy, repair of interstrand crosslinks (ICL) has been studied extensively in prokaryotes and in lower and higher eukaryotes. The main repair pathway inE. coliinvolves the sequential action of nucleotide excision repair and recombinational repair. In eukaryotes, several repair pathways play important roles not only in repair including nucleotide excision repair, translesion synthesis, recombination, but also mismatch repair. Relative contributions of the various pathways depend on cell cycle position and agent used. Eukaryotic proteins that specifically enhance resistance to crosslinking agents have been identified (SNM1,FANCfamily of proteins).Key concepts:Chemicals with two or more correctly spaced reactive groups can covalently link opposing DNA strands.Several repair or tolerance pathways such as nucleotide excision repair, recombination and translesion synthesis can work together to overcome such complex damage.Cell cycle stage may determine the choice of repair pathway combinations.A seemingly deleterious consequence of complex DNA damage (replication fork collapse at a crosslinked site) can be an important integrated part of damage tolerance and repair.A heritable human syndrome with multiple diverse phenotypes (Fanconi anaemia) can be associated with a specific DNA repair deficiency (crosslink repair).
DNAReplication: Mammalian
Authors: Snider Brandy M , Phipps Elizabeth A , Smith Shanna J , Herbert Brittney‐Shea , Hickey Robert J , Malkas Linda H 
Published: December 2009

AbstractIt is well known thatdeoxyribonucleic acid(DNA) replication occurs at the replication fork, whereby the parent strand of DNA unwinds and two daughter strands are formed, which are subsequently synthesized in a leading and lagging strand manner. Furthermore, many proteins and enzymes are involved in initiation of DNA replication, and the synthesis of DNA, as well as the structural component of the nuclear matrix, which allows for attachment of replication proteins. It is also known that replication of mammalian DNA is a very complicated and highly regulated process, requiring strict regulation, along with many different proteins and enzymes. Although there is a wealth of information regarding basic DNA synthesis, there is still much more information to learn regarding the machinery involved in initiation of DNA replication, DNA synthesis and, ultimately, DNA replication.Key Concepts:The proteins thus far identified in mammalian cell DNA replication include the MCM helicase complex, DNA pol α‐primase, PCNA, RFC, DNA pol δ, FEN1, RPA, DNA ligase I, topoisomerase I and II and RNAse H.The manner and timing by which mammalian DNA replication occurs is highly regulated and occurs mostly in the G1 phase of the cell cycle.Telomeres maintain the integrity of the genome by protecting the ends of the chromosomes from degradation and preventing end‐to‐end fusions of chromosomes.Mammalian cells have many levels of tight regulation for the replication of telomeres to maintain genome stability and cell survival.The nuclear matrix plays a vital role in initiation, chromosome replication and regulation.Proteins necessary for DNA replication come together to form ‘replication factories’ within the nucleus.
EukaryoticDNAPolymerases
Authors: Cotterill Sue , Kearsey Stephen 
Published: December 2009

AbstractDeoxyribonucleic acid(DNA) is replicated and repaired by a family of enzymes calledDNA polymerases. Eukaryotic cells have a diversity of these enzymes that, while sharing a common biochemical activity, are specialized for particular roles. Three polymerases are required for the replication of the nuclear genome, withpol αinvolved in priming and initial synthesis andpols δand ɛ involved in bulk DNA replication. These polymerases are dependent on a large number of other proteins which unwind the DNA and perform other functions essential for efficient DNA synthesis. Polymerases are also involved in DNA repair and many repair‐specific enzymes have been identified. Some repair polymerases can refill a gap generated by removal of damaged DNA, or copy a damaged template, allowing DNA synthesis to proceed across a damaged template. Repair polymerases can also have tissue‐specific functions in lymphoid cells, where they contribute to somatic hypermutation of immunoglobulin genes.Key concepts:Catalytic function of DNA polymerases.Concepts of ‘proofreading’ and ‘processivity’.Roles of replicative DNA polymerases needed for chromosome replication and organization at the replication fork.Function of accessory proteins needed for polymerase function in chromosome replication.Different modes of action of specialized polymerases involved in DNA repair.Catalytic mechanism of polymerases.Assays used to detect polymerase functionin vitro.