bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of Inhibitor Squeeze Through Mechanistic Understanding of Inhibitor Chemistry
Authors: Tomson Mason B. , Kan Amy T. , Fu Gongmin 
Published: September 2006

Summary
Chemical scale inhibitors are commonly used to prevent or inhibit scale formation in production. The most economic treatment of scale inhibitor is normally through chemical squeeze. However, there is little agreement regarding the primary mechanism by which the threshold scale inhibitors are retained in producing oil or gas formations as a result of squeeze procedures. Recent advances in phosphonate/rock interaction research at the Rice U. Brine Chemistry Consortium have significantly improved our knowledge of what controls inhibitor placement in the formation. It is commonly suggested that reservoir type determines how an inhibitor is retained in a formation. Our research suggests that the pill chemistry is also an important determinant for retention of carbonate reservoir. Acidic pills are mostly retained near the wellbore, while more neutralized pills move farther into the formation. Three calcium nitrilomethylenephosphonate (NTMP) solid phases, an amorphous phase, and two crystalline Ca2.5HNTMP phases with pKsp = 22.6 and pKsp = 24.2, are particularly important for inhibitor retention. The relative sizes of these solid phases formed are governed by the pill composition and acidity. These results can be explained by a solution-phase-controlled sequence of reactions. All of this information has been incorporated into a new squeeze-design software program, SqueezeSoftPitzer.
A New OCTG Strength Equation for Collapse Under Combined Loads
Authors: Klever F. J. , Tamano T. 
Published: September 2006

Summary
Wells are becoming more challenging, and casing designers are faced with increasing design pressures. Deep hydrocarbon targets lead to requirements for the casing to resist collapse under external pressure, while significant internal pressure and axial compression or tension may exist at the same time.
This paper describes the development, and its evaluation, of a new collapse-strength equation for oil-country tubular goods (OCTG). It is based on a generalization of a model previously proposed by Tamano et al. (1983). The new model is evaluated through comparisons with both finite-element analyses(FEAs) and test data. It is more accurate in dealing with combined internal pressure, external pressure, and axial load than, for example, the model currently provided in American Petroleum Inst. (API) Bull. 5C3 (1994).
The joint API/Intl. Standardization Organization (ISO) subcommittee (SC)5 Work Group (WG) 2B tasked with modernizing the Bull. 5C3 property equations has evaluated a number of collapse models available in the literature on their performance against several collapse databases. As a result, the model presented here is recommended for developing design collapse strengths in the new ISO TR 10400 standard (2006).
Meeting the Challenges in Completion Liner Design and Execution for Two High-Rate Acid-Gas Injection Wells
Authors: Benge Glen , Dew E. G. 
Published: September 2006

Summary
Two high-rate acid-gas injection wells were drilled in the LaBarge area of Wyoming. These wells were designed for injection of up to 65 million scf/D of a mixture of 65% H2S and 35% CO2. The primary engineering challenges in well design, casing selection, and cementing of the injection strings, along with the related operational challenges for both wells, are discussed. Key drivers influencing zonal isolation, salt-zone loading, casing, and centralizer selection are presented.
Casing selection was influenced by corrosive gas composition, high injection rates, and the potential for salt-zone loading. The use of SM–2550 tubulars, heavy wall casing for the salt loading, handling requirements, and centralizer selection are discussed.
The primary driver in cement design was resistance to CO2, because past work has shown little H2S interaction with cement under these well conditions. A discussion of the development of a high-alumina cement system with low fluid loss to address CO2 resistance and long liner length is coupled with the quality-control steps taken from the time of manufacture of the specialty cement to the final placement in the well.
Also described is the development of an alternative portland cement system in which sized particles are included to dilute the cement and reduce total system permeability.
The unique engineering solutions resulted in operational challenges with casing running, cementing materials, and equipment. A description of the location problems and the steps taken to resolve the issues is included.
Swelling of Coal in Response to CO2 Sequestration for ECBM and Its Effect on Fracture Permeability
Authors: Mazumder Saikat , Karnik Amit , Wolf Karl Heinz 
Published: September 2006

Summary
The "swelling" of coal by a penetrant refers to an increase in the volume occupied by the coal as a result of the viscoelastic relaxation of its highly crosslinked macromolecular structure. Projects relating to CO2 sequestration in coal seams suffer a serious setback in terms of injectivity loss resulting from the swelling of coal. Volumetric swelling associated with CO2 sorption on coal has a significant influence on the fracture porosity and permeability of the coal. Two coal samples differing in rank were used for volumetric strain measurements. With CO2, the high-rank Selar Cornish coal showed a maximum volumetric strain of 1.48% corresponding to an average pore pressure of 13 MPa. A matrix swelling coefficient (Cm) of 1.77×10−4 MPa−1 was calculated for this Selar Cornish coal. The low-rank Warndt Luisenthal coal exhibited higher strain of 1.6%, and a matrix swelling coefficient (Cm) of 8.98×10−5 MPa−1 was calculated. The rank dependence of swelling holds true in this set of experiments. Repeat volumetric strain measurement on the same Warndt Luisenthal coal core shows higher volumetric strain values for all pressure steps. A volumetric strain of 1.9% corresponding to a mean pore pressure of 14 MPa was measured. This confirms the process of sequential swelling.
A unique feature of this work is that real-time permeability measurements were done under unconstrained conditions. Permeabilities were measured, reducing the pore pressure from 16 to 1 MPa at constant flow rate. Although measured permeability increased with increasing pore pressure under unconstrained swelling, in-situ permeability will actually decrease because of fracture closure in a constrained coal. To validate the permeability swelling relationship, both permeability measurements under unconstrained conditions and volumetric strain measurements were used.
Electronic Formulations—Photopatterning of Luminescent Conjugated Polymers
Authors: Solomeshch O. , Medvedev V. , Mackie P. R. , Cupertino D. , Razin A. , Tessler N. 
Published: September 2006

AbstractThe versatility of light‐emitting conjugated polymers in terms of optoelectronic properties is enormous, but tailoring of other essential properties has been relatively limited. In other fields such a problem would be rectified using material formulations. However, the need to maintain high optoelectronic compatibility between components has hampered such development. In this paper, careful design of electronically compatible materials is demonstrated. Additive molecules that are compatible with a family of luminescent polymers are presented, and their performance in a light‐emitting diode configuration is demonstrated. This formulation is aimed to adjust the glass‐transition temperature, maintain/improve film‐forming ability, and introduce a crosslinking functionality. It is found that, by using electronic formulations, a robust procedure is obtained that could be used to produce waveguide lasers or full‐color displays. The patterning ability is shown via the construction of a single pixel that is half green and half orange.
High‐Rate LiFePO4 Electrode Material Synthesized by a Novel Route from FePO4 · 4H2O
Authors: Wang Y. , Wang J. , Yang J. , Nuli Y. 
Published: September 2006

AbstractA LiFePO4 material with ordered olivine structure is synthesized from amorphous FePO4 · 4H2O through a solid–liquid phase reaction using (NH4)2SO3 as the reducing agent, followed by thermal conversion of the intermediate NH4FePO4 in the presence of LiCOOCH3 · 2H2O. Simultaneous thermogravimetric–differential thermal analysis indicates that the crystallization temperature of LiFePO4 is about 437 °C. Ellipsoidal particle morphology of the resulting LiFePO4 powder with a particle size mainly in the range 100–300 nm is observed by using scanning electron microscopy and transmission electron microscopy. As an electrode material for rechargeable lithium batteries, the LiFePO4 sample delivers a discharge capacity of 167 mA h g–1 at a constant current of 17 mA g–1 (0.1 C rate; throughout this study n C rate means that rated capacity of LiFePO4 (170 mA h g–1) is charged or discharged completely in 1/n hours), approaching the theoretical value of 170 mA h g–1. Moreover, the electrode shows excellent high‐rate charge and discharge capability and high electrochemical reversibility. No capacity loss can be observed up to 50 cycles under 5 C and 10 C rate conditions. With a conventional charge mode, that is, 5 C rate charging to 4.2 V and then keeping this voltage until the charge current is decreased to 0.1 C rate, a discharge capacity of ca. 134 mA h g–1 and cycling efficiency of 99.2–99.6 % can be obtained at 5 C rate.
Acquired von Willebrand syndrome: Diagnostic problems and therapeutic options
Authors: Eikenboom Jeroen C.J. , Tjernberg Pernilla , Van Marion Vincent , Heering Karel J. 
Published: September 2006

AbstractWe present a case of acquired von Willebrand syndrome (AVWS) due to a monoclonal gammopathy of undetermined significance. Initially this case was diagnosed as congenital von Willebrand disease (VWD); however, re‐examination of the medical history rendered a congenital bleeding disorder unlikely. A normal plasma von Willebrand factor (VWF) propeptide level and a very short half‐life of VWF after a test infusion with factor VIII/VWF concentrate confirmed the diagnosis AVWS. Two major surgical procedures were successfully managed using high‐dose intravenous immunoglobulin. The differential diagnosis with congenital VWD and the diagnostic and therapeutic approaches of AVWS are discussed. We conclude that the diagnosis of AVWS relies primarily on clinical suspicion and a careful bleeding history. A correct diagnosis is essential for optimal perioperative management and treatment of bleeding episodes. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Platelet functional implications of glycoprotein Ibα polymorphisms in African Americans
Authors: Williams Marlene S. , Ng'alla Ladina S. , Vaidya Dhananjay 
Published: September 2006

AbstractThe platelet glycoprotein Ibα is crucial in the binding of platelets to Von Willebrand Factor within areas of high stress. A single nucleotide polymorphism of GP Ibα gives rise to the Koa (HPA‐2b) and the ‐5C Kozak polymorphism. The presence of these polymorphisms has been associated with an increased risk for atherothrombotic disease. The Koa polymorphism has been shown to have a higher prevalence in African Americans compared to American Caucasians. However, very little is known regarding any functional consequences of these platelet polymorphisms in African Americans. We assessed the prevalence of the Ko and ‐5C Kozak polymorphisms in a population of both African American and American Caucasian patients with and without CAD and determined whether there were platelet functional consequences in both groups. We studied 99 patients of which 22 were African American and 77 were American Caucasian. Aggregations were performed and shear induced platelet plug formation was tested using a platelet function analyzer. The HPA‐2b allele was significantly higher in African Americans when compared to Caucasians (P = 0.001). Genotype frequencies of the ‐5C Kozak polymorphism were not significantly different between the two groups. We found no differences in platelet aggregation in African Americans who were either heterozygous or homozygous for the HPA‐2b allele or the ‐5C Kozak allele when compared to American Caucasians of the same category. We found no significant differences in PFA‐100 testing. We conclude from our study that these polymorphisms do not lead to altered platelet function in African Americans. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Hypocupremia associated with prior vitamin B12 deficiency
Authors: Prodan Calin I. , Bottomley Sylvia S. , Vincent Andrea S. , Cowan Linda D. , Holland Neil R. , Lind Stuart E. 
Published: September 2006

AbstractClinical similarities between vitamin B12 and copper deficiencies prompted us to investigate if hypocupremia is present in patients receiving vitamin B12 supplementation. Our pilot study results indicate that a significant number of elderly patients with prior diagnosis of vitamin B12 deficiency have also undiagnosed hypocupremia. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Zur Unmöglichkeit der Geruchsvorhersage
Authors: Sell C. S. 
Published: September 2006

AbstractSeit mehr als einem Jahrhundert sind Chemiker bestrebt, mehr über die faszinierende und rätselhafte Beziehung zwischen der Molekülstruktur und dem Geruch herauszufinden. Trotz intensiver Forschung zu Struktur‐Geruchs‐Beziehungen bleibt die Vorhersage des Geruchs einer neuen Verbindung aber eine statistische Übung, und Modelle können bestenfalls Aussagen über die Wahrscheinlichkeit von Art, Schwellenwert und Intensität eines Geruchs treffen. Überraschungen sind auf diesem Gebiet alltäglich, und der Zufall bleibt ein wichtiger Faktor bei der Entdeckung neuer Duftstoffe. Neuere Erkenntnisse zum Mechanismus der Geruchswahrnehmung bieten eine Erklärung hierfür und lassen darauf schließen, dass sich unsere Fähigkeit zur Vorhersage der Geruchseigenschaften von Verbindungen in naher Zukunft nicht wesentlich verbessern wird.
p53—A Natural Cancer Killer: Structural Insights and Therapeutic Concepts
Authors: Römer Lin , Klein Christian , Dehner Alexander , Kessler Horst , Buchner Johannes 
Published: September 2006

AbstractEvery single day, the DNA of each cell in the human body is mutated thousands of times, even in absence of oncogenes or extreme radiation. Many of these mutations could lead to cancer and, finally, death. To fight this, multicellular organisms have evolved an efficient control system with the tumor‐suppressor protein p53 as the central element. An intact p53 network ensures that DNA damage is detected early on. The importance of p53 for preventing cancer is highlighted by the fact that p53 is inactivated in more than 50 % of all human tumors. Thus, for good reason, p53 is one of the most intensively studied proteins. Despite the great effort that has been made to characterize this protein, the complex function and the structural properties of p53 are still only partially known. This review highlights basic concepts and recent progress in understanding the structure and regulation of p53, focusing on emerging new mechanistic and therapeutic concepts.
Sustaining water resources in South East England
Authors: Rodda John C. 
Published: September 2006

AbstractThe South East of England is one of the driest regions of the UK and it is also one of the most densely populated. As a consequence the available water resource per head of population is about half of the figure used by the World Bank to indicate that a country is suffering water stress. The South East Plan, prepared by the South East England Regional Assembly, proposes to increase the population of the region by about 1 million by 2026. This paper considers the ability of the Region's water resources to cope with this growth. Copyright © 2006 Royal Meteorological Society
Krank durch Stress: Molekulare Wirkmechanismen und Folgen für die Gesundheit
Authors: Rensing Ludger 
Published: September 2006

AbstractPsychosozialer Stress hat deutliche Wirkungen auf das Immunsystem: kurzer kontrollierbarer Stress beeinflusst eine Reihe von Immunfunktionen positiv, während traumatische Erfahrungen, chronischer Stress oder Depressionen viele Immunfunktionen hemmen. Übermittelt werden die Stresswirkungen über das neuroendokrine System. Das neuroendokrine System wirkt auf die Produktion von Cytokinen in den Immunzellen über diverse Rezeptoren und Proteinkinasen und deren Einfluss auf die Aktivität von verschiedenen Transkriptionsfaktoren, insbesondere auf die des nuclear factor kappaB (NFκB). Stressbelastungen sind oft an chronischen Entzündungen in verschiedenen Geweben beteiligt. Dagegen werden zurzeit Medikamente entwickelt, die in die molekularen Mechanismen der Entzündungsprozesse eingreifen.
Spinnennetz nur einmal erfunden
Authors: Brennicke Axel 
Published: September 2006

AbstractHeutzutage nutzen Spinnen zwei unterschiedliche Methoden, um ihre Netze klebrig zu machen. Wissenschaftler waren lange im Zweifel, ob Spinnennetze einmal oder mehrmals erfunden wurden. Neue Befunde belegen jetzt, dass in der Evolutionsgeschichte die Idee für das Netz weltweit nur einmal auftauchte und seit mehr als 100 Millionen Jahren erfolgreich eingesetzt wird.
Darwinfinken – die Evolution geht weiter
Authors: Wendler Silke 
Published: September 2006

AbstractGalapagosfinken gelten seit der Zeit von Charles Darwin als Paradebeispiel für die Evolution durch Selektion. Kürzlich veröffentlichte Beobachtungen über den Mittleren Grundfink (Geospiza fortis) zeigen eine Veränderung der Schnabelgröße, die durch Nahrungskonkurrenz mit dem Großen Grundfink (Geospiza magnirostris) hervorgerufen wurde. Verblüfft hat bei diesen Beobachtungen die Geschwindigkeit, mit denen sich diese Veränderung durchgesetzt hat.
Current role of radiofrequency ablation for the treatment of colorectal liver metastases
Authors: McKay A , Dixon E , Taylor M 
Published: September 2006

AbstractBackground and methodThis paper reviews the current status of radiofrequency ablation in the treatment of colorectal liver metastases. Relevant studies with at least ten patients that reported rates of complete tumour ablation, local recurrence, or survival from 1 to 5 years after treatment were included in the review.Results and conclusionOnly six studies that reported at least 3-year survival were identified, with results ranging from 37 to 58 per cent. Some of these figures are promising, given that the patients were considered to have unresectable disease. However, available evidence is limited and hepatic resection remains the standard of care when feasible; radiofrequency ablation cannot be considered an equivalent. Radiofrequency ablation does, however, appear to have a role in treating unresectable disease, and may also be used in conjunction with resection to extend its limits.
Diversity‐Oriented Approach to Biologically Relevant Molecular Frameworks Starting with β‐Naphthol and Using the Claisen Rearrangement and Olefin Metathesis as Key Steps
Authors: Kotha Sambasivarao , Mandal Kalyaneswar , Tiwari Arti , Mobin Shaikh M. 
Published: September 2006

AbstractA diversity‐oriented approach for the synthesis of various structurally different molecular frameworks from readily accessible and common precursors is described. A Claisen rearrangement followed by ring‐closing metathesis or ethylene‐promoted ring‐closing enyne metathesis has been utilized as the key synthetic transformation to generate naphthoxepine derivatives. The ring‐closing metathesis approach has also been used to generate spirocyclic compounds and the pleiadene framework.
Linear systems analysis of the ciliary steering behavior associated with negative‐phototaxis in Chlamydomonas reinhardtii
Authors: Josef Keith , Saranak Jureepan , Foster Kenneth W. 
Published: September 2006

AbstractIn response to light stimulation Chlamydomonas reinhardtii changes the beating frequency, beating pattern, and beating synchrony of the trans and cis cilia to steer the freely‐swimming cell relative to light sources. To understand the cell steering behavior the impulse responses of the beating frequency and stroke velocity of each cilium have been obtained with high temporal resolution on cells held with a micropipette. Interestingly the response of each cilium is quite different. The trans cilium responds with less delay than the cis cilium for both beating frequency and stroke velocity. For light stimulation at 2 Hz, the critical cell‐rotation frequency, both responses of the trans and cis cilia are about 180° out of phase. The trans‐cilium beating frequency response peaks at a stimulus frequency of 5–6 Hz, higher than the cis at 1–2 Hz. The stroke velocities of the trans and cis cilia have the same stimulus‐frequency response (˜2 Hz), but the trans cilium has a shorter delay than the cis. The times to maximum response are much shorter than the time for a rotation of the cell. The use of two different approaches that enable the trans cilium to respond ahead of the cis for both the beating frequency and stroke velocity responses suggests the importance of both responses to phototaxis. Internal cell processing responsible for the time course of the responses is proposed. Cell Motil. Cytoskeleton 2006. © 2006 Wiley‐Liss, Inc.
Potential diagnostic value of methylation profile in pleural fluid and serum from cancer patients with pleural effusion
Authors: Benlloch Susana , Galbis‐Caravajal Jose Marcelo , Martín Concepcion , Sanchez‐Paya Jose , Rodríguez‐Paniagua Jose Manuel , Romero Santiago , Mafe Juan Jose , Massutí Bartomeu 
Published: September 2006

AbstractBACKGROUND.The objective of this study was to investigate the diagnostic value of methylation profiles for discrimination between malignant and benign pleural effusions. A secondary objective was to examine the concordance of methylation in samples of serum and pleural fluid.METHODS.The authors used methylation‐specific polymerase chain reaction (MSP) analysis to examine the promoter methylation status of 4 genes in patients with pleural effusion: death‐associated protein kinase (DAPK), Ras association domain family 1A (RASSF1A), retinoic acid receptor β (RARβ), and p16/INK4a. Pleural effusions were collected from 87 patients who had their diagnoses confirmed on cytologic and/or histologic examinations and clinical evolution. Pleural effusions were classified as malignant (n = 53 patients) or benign (n = 34 patients).RESULTS.Methylation was detected in serum from 45.3% of patients with malignant pleural effusions and from 0% of patients with benign pleural effusions, and it was detected in pleural fluid samples from 58.5% of patients with malignant pleural effusions and from 0% of patients with benign pleural effusions (P = .001). The sensitivity of MSP was greater than that of cytologic examination alone (39.1%; P = .001). When MSP was used together with cytologic examination, sensitivity increased to 69.8% (P = .001).CONCLUSIONS.Cell‐free methylated DNA in pleural fluid can be detected in patients with neoplastic malignancy in a single extraction by thoracocentesis. Adequate management of the extracted pleural fluid can provide a rapid and reliable diagnosis in patients with pleural effusions who have suspected malignancy. MSP, used together with cytologic examination, may obviate the need for other invasive diagnostic tests. Cancer 2006. © 2006 American Cancer Society.