bluuebunny/crossref_metadata_2025_split huggingface dataset:
A History of Frac-Pack Scale-Inhibitor Deployment
Authors: Fitzgerald Aine M. , Cowie Laurence G. 
Published: February 2008

Abstract
In recent years, BP has moved into reservoirs in deep water subsea projects where sea water flooding is required for reserves recovery. The introduction of sulfate rich seawater into a reservoir producing a formation brine rich in barium ions significantly increases the potential for barium sulfate scale deposition. This type of scale is not acid soluble, unlike the carbonate based scales traditionally encountered in many regions. Alkaline based chelants, such as EDTA and DTPA, are only effective at removing small accumulations. Mechanical removal is generally considered to be the only effective removal option for significant sulfate scale deposits in the tubing but is not appropriate for removing scale from within the near well bore area or within a frac-pack or screen. Thus the recommended management strategy is one of prevention rather than remediation.
A combination of the low geomechanical strength of these reservoirs and other rock characteristics has led to the adoption of frac-pack completions for effective sand control. This type of completion presents a new challenge for placing scale inhibitor and managing the scale risks in frac-packed wells. BP has significant experience of preventative squeeze treatments in sea water flooded reservoirs in the UK and elsewhere. However, the majority of this experience lies with cased and perforated completions. Unlike cased and perforated wells, mechanical removal of sulphate scale from behind a frac-pack screen or within proppant filled perforations is not physically possible with mechanical methods. The damage to the rock and the gravel or screen completion elements can be permanent. If the accumulation is significant and chemical dissolution is considered impractical then, ultimately, sidetracking may be the only option to recover productivity. The cost of restoring production to a scale damaged frac-packed deep water subsea well is very significant due to the high cost of intervention and limited rig availability. In addition, as most deep water subsea projects have a relatively low well count the impact of scale formation to a particular well has a greater impact on the overall production loss. Effective prevention is therefore critical. However, industry experience in squeezing deep water, subsea, frac-packed and multi-zoned wells is limited with uncertain treatment longevity. At the same time, subsea scale inhibitor squeezes, while shown to be effective, have a significant treatment cost.
This paper describes a particular aspect of the multi faceted scale management strategy adopted by our deep water subsea projects for managing wells with frac-packed completions. It describes the inclusion of scale inhibitor within the proppant pack at the completion stage to provide protection against scale related damage during the early stages of water breakthrough. The paper highlights the testing necessary to qualify the products selected and describes initial performance data from several of our major deep water fields.
Relative Permeability Modifier (RPM): Suitability Screening With Reservoir Core Under Reservoir Conditions
Authors: Cornwall Clive , Boughey Adam 
Published: February 2008

Abstract
The number of maturing reservoirs is increasing and the need to manage water production is becoming ever more pressing. As has been observed repeatedly it requires at least the same amount of energy to produce a barrel of water as it does to recover a barrel of oil. Water Shutoff Chemical Systems, especially the new generation of Relative Permeability Modifiers (RPM), offer a potential solution to the problems of excessive water production.
Polymers, in the form of weak solutions, are intended to control water production, especially when oil bearing and water zones cannot be isolated. These products, identified as Relative Permeability Modifiers, are introduced to the reservoir, typically by bullhead injection or as fracture additives, with the intention of reducing the relative permeability to water, while avoiding as much as possible any reduction in the relative permeability to oil. The phenomenon that the placement seeks to induce is disproportionate permeability reduction (DPR) and will, where successfully applied, significantly reduce production costs.
The claims made for the various RPM products in the technical and sales literature suggest that their applicability is essentially universal; being largely independent of such key parameters as wettability, pore throat size, clay content, saturation profile and temperature. If this were the case, RPMs would be employed on a routine basis, rather than infrequently, accompanied with a healthy level of scepticism. In reality each RPM treatment should be case specific, affording the client the opportunity to test the various products on offer. It also provides the suppliers with the opportunity to optimise the formulation of their particular Relative Permeability Modifier through the offices of an independent laboratory.
This screening process is achieved through the deployment of representative and fully characterised core material, prepared to preserve factors such as wettability and clay fraction integrity. The testing on this material, undertaken at reservoir conditions of temperature and pressure, yields, on a "before and after" treatment basis, effective permeability and saturation data sets. From these values (Residual) Resistance Factors for the two fluid phases are produced, to quantify the effectiveness of the impedance of water flow, without significantly reducing oil production.
A Comparison of Websites from Spanish, American and British Hospitals
Authors: Llinás G. , Rodríguez-Iñesta D. , Lorenzo S. , Aibar C. , Mira J. J. 
Published: February 2008

Summary

Objective:
To evaluate and compare the user-orientation of Spanish, American and British hospital websites.

Methods:
A descriptive study of 32 hospital portals (12 Spanish, 10 American and 10 British) was carried out in which the following were analyzed: website readability according to the Flesch Index, websites accessibility using the Web Accessibility Test, and the quality of information provided using the “e-Information Scale of Health Care Centers”.

Results:
Fifty percent of the user-oriented information quality attributes are met. Readability indices tend to be below 60 (standard readability), and only 10 of the 32 websites meet the accessibility criteria.

Conclusions:
Most portals exhibit accessibility problems that favor computer illiteracy. There is a wide variability in terms of website readability and in terms of useroriented content.
Direct Asymmetric Dynamic Kinetic Resolution by Combined Lipase Catalysis and Nitroaldol (Henry) Reaction
Authors: Vongvilai Pornrapee , Larsson Rikard , Ramström Olof 
Published: February 2008

AbstractThe asymmetric synthesis of β‐nitroalkanol derivatives was simply achieved by a combined nitroaldol (Henry) reaction with lipase‐catalyzed transesterification in high yield and enantiomeric purity (up to 92% and 99% ee) through a direct one‐pot procedure.
Unusual Totally Selective Cyclodimerization of Epoxides: Synthesis of a Pair of Diastereoisomers of Enantiopure 2,5‐Disubstituted‐1,4‐Dioxanes with C2 Symmetry
Authors: Concellón José M. , Bernad Pablo L. , del Solar Virginia , García‐Granda Santiago , Díaz M. Rosario 
Published: February 2008

AbstractThe synthesis of the C2‐symmetrical (2R,5R)‐ and (2S,5S)‐2,5‐bis‐[(S)‐1‐(dibenzylaminoalkyl)]‐1,4‐dioxanes 1 or 2 in enantiopure form is reported. Compounds 1 and 2 were obtained by a completely selective and unusual cyclodimerization of chiral (2R,1′S)‐ or (2S,1′S)‐2‐(1‐aminoalkyl)epoxides 3 or 4 promoted by a mixture of diisopropylamine and boron trifluoride⋅diethyl etherate complex. The structure of the obtained dioxane was established by single‐crystal X‐ray diffraction analysis. A mechanism has been proposed to explain this transformation.
The limiting current for reduction of ferricyanide ion at nickel: The importance of experimental conditions
Authors: Szánto D. A. , Cleghorn S. , Ponce‐de‐León C. , Walsh F. C. 
Published: February 2008

AbstractSteady state, hydrodynamic voltammetry is a well‐established technique to measure the rate of mass transport of an electroactive species to, or from, a solid surface electrode in an aqueous electrolyte. Limiting current measurements during the reduction of ferricyanide (hexacyanoferrateIII) ion at a nickel rotating disc electrode (RDE) are critically considered, and the accuracy of the technique is quantitatively assessed. The importance of surface pretreatment, type of indifferent electrolyte, and the effect of sunlight are considered. Limiting current values can show large deviations from the values predicted by the Levich equation for laminar flow to a polished RDE when unsuitable conditions are employed, despite the appearance of well‐defined limiting current plateaux. Using appropriate pretreatment and experimental procedures, the averaged mass transport coefficients or limiting currents values can be obtained, which are close to the values predicted by the Levich equation for laminar flow to a hydrodynamic smooth RDE. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Variation and heritability of Hb F and F‐cells among β‐thalassemia heterozygotes in Hong Kong
Authors: Gibney Geoffrey T. , Panhuysen Carolien I.M. , So Jason C.C. , Ma Edmond S.K. , Ha Shau Yin , Li Chi Kong , Lee Anselm C.W. , Li Chi Keung , Yuen Hui Leung , Lau Yu Lung , Johnson David M. , Farrell John J. , Bisbee Alice B. , Farrer Lindsay A. , Steinberg Martin H. , Chan Li Chong , Chui David H.K. 
Published: February 2008

AbstractEnhanced fetal hemoglobin (Hb F) production can partially compensate for the lack of adult hemoglobin (Hb A) in patients with β‐thalassemia major or intermedia, and ameliorate the clinical severity of these diseases. To further elucidate factors governing Hb F levels, we evaluated demographic, clinical, laboratory, and genetic characteristics in 241 unrelated adult β‐thalassemia carriers in Hong Kong. They had wide variations in Hb F and F‐cell numbers skewing toward higher levels. Individuals who coinherited the Xmn IT‐allele in the Gγ‐globin gene promoter had higher Hb F and more F‐cells compared with those lacking the Xmn I T‐allele. However, both groups exhibited a similarly wide spread of Hb F and F‐cells. The correlation of Hb F and F‐cells corresponded well to both linear and exponential models, suggesting multiple mechanisms for Hb F augmentation. The heritabilities of Hb F and F‐cells were calculated in 66 families (111 parents who were β‐thalassemia carriers and 82 asymptomatic offspring) to be 0.7 to 0.9. The Xmn I polymorphism accounted for 9% of the Hb F and 13% of the F‐cell heritabilities. These results suggest that these family members are well suited for genome wide association studies that will identify genetic loci regulating Hb F production, and likely novel pharmacological targets for reactivating Hb F production in adults. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Hematological abnormalities in patients with distal renal tubular acidosis and hemoglobinopathies
Authors: Khositseth Sookkasem , Sirikanaerat Apiwan , Khoprasert Siri , Opastirakul Sauwalak , Kingwatanakul Pornchai , Thongnoppakhun Wanna , Yenchitsomanus Pa‐thai 
Published: February 2008

AbstractMutations of the human SLC4A1 gene encoding erythroid and kidney isoforms of anion exchanger 1 (AE1, band 3) result in erythrocyte abnormalities or distal renal tubular acidosis (dRTA) and such mutations are observed in Southeast Asia, where hemoglobinopathies are prevalent. Genetic and hematological studies in 18 Thai patients with dRTA have shown that 12 of them (67%) carried SLC4A1 mutations (7 G701D/G701D, 3 SAO/G701D, and 2 G701D/A858D). Of these 12 patients, three had homozygous G701D/G701D and heterozygous Hb E; one compound heterozygous SAO/G701D and heterozygous α+‐thalassemia; and one compound heterozygous G701D/A858D and heterozygous Hb E. Of 6 patients without SLC4A1 mutation, two each carried heterozygous or homozygous Hb E and one of the latter also had Hb H disease (‐‐SEA/‐α4.2). The blood smears of patients with homozygous G701D/G701D showed ∼25% ovalocytes. Strikingly, the patients with coexistence of homozygous G701D/G701D and heterozygous Hb E had 58% ovalocytes. Similarly, the patients who had compound heterozygous SAO/G701D showed 49% ovalocytes, but the patient with coexistence of compound heterozygous SAO/G701D and heterozygous α+‐thalassemia had 70% ovalocytes. Our previous study has shown that under metabolic acidosis, the patients with homozygous G701D/G701D or compound heterozygous SAO/G701D had reticulocytosis, indicating compensated hemolysis. A patient with compound heterozygous SAO/G701D and heterozygous α+‐thalassemia presented with hemolytic anemia and hepatosplenomegaly which was alleviated by alkaline therapy. Taken together, the coexistence of both homozygous or compound heterozygous SLC4A1 mutations and hemoglobinopathy has a combined effect on red cell morphology and degree of hemolytic anemia, which is aggravated by acidosis. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Child and genetic variables associated with maternal adaptation to fragile X syndrome: A multidimensional analysis
Authors: Bailey Donald B. , Sideris John , Roberts Jane , Hatton Deborah 
Published: February 2008

AbstractOne hundred eight carrier mothers (95 premutation, 13 full mutation) of children with the full mutation fragile X syndrome completed seven scales to assess maternal stress, depressive symptoms, anger, anxiety, quality of life, hope, and optimism. A wide range of responses was found on each measure, with most mothers scoring in the non‐clinical range on any individual measure. However, nearly half of the mothers scored in the clinically significant range on at least one measure and 25% on two or more measures. High stress and low quality of life were the most common domains of concern. Mothers with the full mutation generally did not differ from mothers with the premutation. CGG repeat length was not associated with responses on any of the measures completed by mothers with the premutation. Severity of the child's delay was not associated with any of the outcome measures, but child behavior problems accounted for significant variance in stress, depressive symptoms, anxiety, anger, and quality of life. Maternal adaptation appears to be a multidimensional phenomenon experienced in unique ways by each mother. Most mothers experienced positive adaptation, but a subset appear to be more vulnerable, especially those with children who have significant behavior problems. Future research needs to identify family, child, and support factors associated with maternal vulnerability and how adaptation changes over time in response to these factors. © 2008 Wiley‐Liss, Inc.
Inverted duplication with terminal deletion of 5p and no cat‐like cry
Authors: Wang Jia‐Chi , Coe Bradley P. , Lomax Brenda , MacLeod Patrick M. , Parslow Malcolm I. , Schein Jacqueline E. , Lam Wan L. , Eydoux Patrice 
Published: February 2008

AbstractWe report on a 6‐year‐old boy referred for cytogenetics study. A few non‐specific features were observed in the newborn: hypotonia, failure to thrive, seizures, pre‐auricular skin tags. Cat‐like cry was not identified. No remarkable facial dysmorphism, gastrointestinal, respiratory or cardiac abnormalities were identified. At age 4 years, speech and motor skill delays were apparent. Karyotyping and FISH analysis revealed a de novo rearranged chromosome 5p, with subtelomeric deletion of 5p and a duplication of the cri‐du‐chat critical region. Array CGH using sub‐megabase resolution tiling‐set (SMRT) array followed by FISH analysis with labeled BACs showed a deletion of 5pter to 5p15.31 (0–6.9 Mb) and an inverted duplication of the greater part of 5p15.31 to the distal end of 5p14.3 (6.9–19.9 Mb). Although very rare, inverted duplications with terminal deletion (inv dup del) have been reported at different chromosomal ends. Our finding adds a second patient of inv dup del 5p to this growing list, and the potential causative mechanisms for this rearrangement are discussed. Review of the mapping information of cri‐du‐chat patients and the comparison with a previously reported patient suggested that the critical region for cat‐like cry is located within a 0.6 Mb region. © 2008 Wiley‐Liss, Inc.
Poly(lactic‐co‐glycolic acid) nanospheres and microspheres for short‐ and long‐term delivery of bioactive ciliary neurotrophic factor
Authors: Nkansah Michael K. , Tzeng Stephany Y. , Holdt Adam M. , Lavik Erin B. 
Published: February 2008

AbstractCiliary neurotrophic factor (CNTF) has been shown to be neuroprotective in the central nervous system (CNS). However, systemic administration and bolus injections have shown significant side effects and limited efficacy. Sustained, local delivery may lead to effective neuroprotection and avoid or limit adverse side effects, but sustained CNTF delivery has proven difficult to achieve and control. For controlled, sustained delivery, we investigated several processing variables in making poly(DL‐lactic‐co‐glycolic acid) (PLGA) nano‐ and microspheres to optimize CNTF encapsulation and release. Nano‐ and microspheres were 314.9 ± 24.9 nm and 11.69 ± 8.16 µm in diameter, respectively. CNTF delivery from nanospheres was sustained over 14 days, and delivery from microspheres continued over more than 70 days. To assess protein bioactivity after encapsulation, neural stem cells (NSCs) were treated with CNTF released from nanospheres and compared to those treated with unencapsulated CNTF as a control. NSCs treated with CNTF expressed markers specific to mature cells, notably astrocytes; some increase in oligodendrocytic and neuronal marker expression was also observed. Significantly, cells treated with CNTF released by nanospheres exhibited a similar degree of differentiation when compared to those treated with control CNTF of equivalent concentration, showing that the process of protein encapsulation did not reduce its potency. Biotechnol. Bioeng. 2008;100: 1010–1019. © 2008 Wiley Periodicals, Inc.
Characterization of porous poly(D,L‐lactic‐co‐glycolic acid) sponges fabricated by supercritical CO2 gas‐foaming method as a scaffold for three‐dimensional growth of Hep3B cells
Authors: Zhu Xin Hao , Lee Lai Yeng , Jackson Jie Sheng Hong , Tong Yen Wah , Wang Chi‐Hwa 
Published: February 2008

AbstractThis study presents the application of the porous poly(D,L‐lactic‐co‐glycolic acid) (PLGA) sponges fabricated from an organic solvent free supercritical gas foaming technique. Two formulations of PLGA sponges with different co‐polymer compositions (85:15 and 50:50) were fabricated as novel scaffolds to guide human hepatoma cell line, Hep3B cell growth in vitro. The PLGA sponges showed desirable biodegradability and exhibited uniform pore size distribution with moderate interconnectivity. It was observed in this study that cells cultured on PLGA sponges showed lower proliferation rate as compared to the control during 14 days of culture as measured by using total DNA and methylthiazol tetrazolium (MTT) assays. However, the cells cultured on the sponges tended to aggregate to form cell islets which were able to express better hepatic functions. The enzyme‐linked immunosorbent assay (ELISA) results showed that the cell‐sponge constructs secreted 1.5–3.0 times more albumin than the control when normalized to cellular content. In a similar fashion, its detoxification ability was also predominantly higher than that of the control as indicated by the ethoxyresorufin‐O‐deethylase (EROD) results. By comparing the cells growing on the two formulations of PLGA sponges, it was found that the PLGA 85:15 sponge exhibited better conductive and desirable environment for hep3B cells as justified by better cell infiltration, higher proliferation and hepatic function than the PLGA 50:50 sponge. Biotechnol. Bioeng. 2008;100: 998–1009. © 2008 Wiley Periodicals, Inc.
Biohydrogen production from glucose in upflow biofilm reactors with plastic carriers under extreme thermophilic conditions (70°C)
Authors: Zheng Hang , Zeng Raymond J. , Angelidaki Irini 
Published: February 2008

AbstractBiohydrogen could efficiently be produced in glucose‐fed biofilm reactors filled with plastic carriers and operated at 70°C. Batch experiments were, in addition, conducted to enrich and cultivate glucose‐fed extreme‐thermophilic hydrogen producing microorganisms from a biohydrogen CSTR reactor fed with household solid waste. Kinetic analysis of the biohydrogen enrichment cultures show that substrate (glucose) likely inhibited hydrogen production when its concentration was higher than 1 g/L. Different start up strategies were applied for biohydrogen production in biofilm reactors operated at 70°C, and fed with synthetic medium with glucose as the only carbon and energy source. A biofilm reactor, started up with plastic carriers, that were previously inoculated with the enrichment cultures, resulted in higher hydrogen yield (2.21 mol H2/mol glucose consumed) but required longer start up time (1 month), while a biofilm reactor directly inoculated with the enrichment cultures reached stable state much faster (8 days) but with very low hydrogen yield (0.69 mol H2/mol glucose consumed). These results indicate that hydraulic pressure is necessary for successful immobilization of bacteria on carriers, while there is the risk of washing out specific high yielding bacteria. Biotechnol. Bioeng. 2008;100: 1034–1038. © 2008 Wiley Periodicals, Inc.
The fate of Pluronic F‐68 in chondrocytes and CHO cells
Authors: Gigout Anne , Buschmann Michael D. , Jolicoeur Mario 
Published: February 2008

AbstractThe surfactant Pluronic F‐68 (PF‐68) is widely used in large‐scale mammalian cell culture to protect cells from shear stress that arises from agitation and gas sparging. Several studies suggested that PF‐68 is incorporated into the cell plasma membrane and could enter the cells, but without providing any direct evidence. The current study has examined this question for two cell types, one of pharmaceutical interest (CHO cells) and the other of biomedical interest (chondrocytes or cartilage cells). A fluorescent derivative of PF‐68 was synthesized to detect and localize internalized Pluronic with culture time. PF‐68 uptake by the cells was quantified and characterized. We clearly demonstrate that PF‐68 enters the cells, and possibly accumulates in the endocytic pathway. CHO cells showed an average uptake of 11.7 ± 6.7 (SEM) µg PF‐68/106 cells while the uptake of chondrocytes was 56.0 ± 10.9 (SEM) µg PF‐68/106 cells, independently of the initial PF‐68 concentration (between 0.01 and 0.2%, w/v) and of cell concentration (from 1 × 106 to 4 × 106 cells/mL). These uptake values were identical for both static and agitated culture conditions. Finally, we found that CHO cells are able to eliminate intracellular fluorescent PF‐68 but chondrocytes are not. These results show that the uptake of PF‐68 by the cells can severely affect PF‐68 concentration in the culture medium and thus shear protection effect. Biotechnol. Bioeng. 2008;100: 975–987. © 2008 Wiley Periodicals, Inc.
ChemInform Abstract: Hf(OTf)4‐Doped Me3SiCl‐Catalyzed Aminomethylation of Arenes with N,O‐Acetals: Facile Approach to Non‐Natural Aromatic Amino Acid Precursors.
Authors: Sakai Norio , Asano Junichi , Shimano Yuta , Konakahara Takeo 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.