bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymorphism of isotypic series of homoleptic 1,2,3-triazolate MOFs [Ln(Tz*)3] containing the heavy lanthanides Gd–Lu: from open to dense frameworks of varying dimensionality
Authors: Rybak Jens-Christoph , Tegel Marcus , Johrendt Dirk , Müller-Buschbaum Klaus 
Published: February 2010

Abstract
Homoleptic MOF structures of the formulas 2
∞[Ln(Tz*)3] and 3
∞[Ln(Tz*)3], (Tz*)– = 1,2,3-triazolate anion, C2H2N3
–, Ln = Gd-Lu, were obtained by the reaction of the lanthanide metals with the aromatic heterocyclic amine 1H-1,2,3-triazole. The isotypic series of compounds are real polymorphs as they have identical constitution. The 2-dimensional MOF is formed at lower temperatures whereas formation of the 3-dimensional MOF requires higher temperatures, in some cases solvothermal reaction conditions. We therefore address them as low-temperature α-form and high-temperature β-form. The thermodynamically stable β-form exhibits high thermal stabilities regarding compounds that contain three neighboring nitrogen atoms in one organic ring, ranging up to 380 °C. Transition from α to β-form is accompanied by transformation from open to dense frameworks as only the α-form contains structural voids. This goes along with both an increase of dimensionality of the linkage from 2D to 3D and an increase of the density of the structures. The α-form adopts the AlCl3 structure, the β-form can be identified with a (10,3)-b net. Although no single crystals could be obtained for β-3
∞[Ln(Tz*)3], structure solution and reasonable refinement were successful from X-ray powder data. The crystal structure of α-2
∞[Ln(Tz*)3] was previously solved from single crystal data.
Amplification of the Gene for Isoleucyl–tRNA Synthetase Facilitates Adaptation to the Fitness Cost of Mupirocin Resistance inSalmonella enterica
Authors: Paulander Wilhelm , Andersson Dan I , Maisnier-Patin Sophie 
Published: February 2010

AbstractMutations that cause resistance to antibiotics in bacteria often reduce growth rate by impairing some essential cellular function. This growth impairment is expected to counterselect resistant organisms from natural populations following discontinuation of antibiotic therapy. Unfortunately (for disease control) bacteria adapt and improve their growth rate, often without losing antibiotic resistance. This adaptation process was studied in mupirocin-resistant (MupR) strains of Salmonella enterica. Mupirocin (Mup) is an isoleucyl–adenylate analog that inhibits the essential enzyme, isoleucyl–tRNA synthetase (IleRS). Mutations causing MupR alter IleRS and reduce growth rate. Fitness is restored by any of 23 secondary IleRS amino acid substitutions, 60% of which leave resistance unaffected. Evidence that increased expression of the original mutant ileS gene (MupR) also improves fitness while maintaining resistance is presented. Expression can be increased by amplification of the ileS gene (more copies) or mutations that improve the ileS promoter (more transcription). Some adapted strains show both ileS amplification and an improved promoter. This suggests a process of adaptation initiated by common amplifications and followed by later acquisition of rare point mutations. Finally, a point mutation in one copy relaxes selection and allows loss of defective ileS copies. This sequence of events is demonstrated experimentally. A better understanding of adaptation can explain why antibiotic resistance persists in bacterial populations and may help identify drugs that are least subject to this problem.
Fetal Exposure to Antidepressants and Normal Milestone Development at 6 and 19 Months of Age
Authors: Pedersen Lars Henning , Henriksen Tine Brink , Olsen Jørn 
Published: February 2010

OBJECTIVE:
The goal was to investigate a possible association between exposure to antidepressants in utero and developmental milestones in early childhood.

METHODS:
Information on pregnancy exposures and developmental milestones at 6 and 19 months was obtained from the Danish National Birth Cohort. Of the eligible pregnant women, 415 used antidepressant medication, 489 reported depression with no medical treatment, and 81 042 reported no depression and no use of psychotropic medication.

RESULTS:
Children with second- or third-trimester exposure to antidepressants were able to sit 15.9 days (95% confidence interval [CI]: 6.8–25.0) and to walk 28.9 days (95% CI: 15.0–42.7) later than children of women not exposed to antidepressants but still were within the normal range of development. Fewer children with second- or third-trimester exposure to antidepressants were able to sit without support at 6 months of age (odds ratio: 2.1 [95% CI: 1.23–3.60]), and fewer were able to occupy themselves at 19 months of age (odds ratio: 2.1 [95% CI: 1.09–4.02]). None of the other milestones measured showed statistically significant associations with antidepressant exposure.

CONCLUSION:
The results of this study suggest a permanent or reversible effect of antidepressant exposure on fetal brain development, which may depend on the timing of exposure during pregnancy.
Gas Reserves Estimation in Resource Plays
Authors: Lee W. J. , Sidle R. E. 
Published: February 2010

Abstract
The petroleum industry's lack of understanding of physical properties and the physics controlling production from many important resource plays limits its ability to model and forecast with confidence production and reserves from these resources. While measurement technology and modeling accuracy is improving, the industry is often forced to resort to empirical methods that lack the usual validation required for high confidence in results. This paper analyzes some of the procedures in common use for forecasting and identifies key strengths and limitations of the techniques.
Development Update for an Emerging Shale Gas Giant Field—Horn River Basin, British Columbia, Canada
Authors: Reynolds M. M. , Munn D. L. 
Published: February 2010

Abstract
The Horn River Basin covers an estimated 3 million acres in a remote and difficult to access area of northern British Columbia. A number of Operators have experimental projects in the area, using various drilling and completion techniques, in order to evaluate the shale reservoir, gas in place, and productivity; moving towards commercial projects. The Devonian age shales of the Horn River Basin have been compared to the Barnett Shale of the Fort Worth Basin, in terms of reservoir quality, productivity and recovery factors.
This paper will review the following important aspects of the Horn River shale area: History of the play;General review of the Geology, reservoir properties, thickness, gas content, gas in place, permeability, etc.;Emerging drilling and completions techniques, well construction, stimulation practices, fracture diagnostics, logistical problems;Production tests, well initial productivities, and longer term production forecasts, estimated recovery factors;Production and Operations challenges;Development costs and economics;Future development hurdles, what is needed to make this play commercial?
Using Microseisms to Monitor Hydraulic Fractures in the Bakken Formation of North Dakota
Authors: Forrest Gary S. , Olsen Thomas N. , Kazantsev Aleksey , Dombrowski Timothy J. , Gomez Ernest , Rowe Wayne 
Published: February 2010

Abstract
The Mississippian-Devonian Bakken Formation is a relatively tight mixed carbonate – clastic sequence in the Williston Basin of North Dakota. Although production can exceed 1000 BOPD, hydraulic fracturing is necessary to induce economic production. In late 2007 seven (7) operators along with Schlumberger formed a consortium for the purpose of applying the best available technologies to examine the geologic factors and the drilling and completion principles that affect production. As part of this, three (3) horizontal wells (each 4000 feet in length) were drilled 1500 feet apart into the Middle Bakken Member. Schlumberger positioned an array of 16 triaxial geophones, spaced 100 feet apart, in the middle lateral (Nesson State 42X-36) to monitor the microseismic activity during the hydraulic fracturing of the two (2) outside wells. Different hydraulic fracturing methods were applied in each stage; ranging from a single treatment in the northern lateral (Nesson State 41X-36) to a six (6) staged treatment with swell packers in the southern lateral (Nesson State 44X-36). The microseismic events were studied in the context of our geologic understanding of the area, comparison to the distributions of radioactive and chemical tracers and a reservoir simulation to develop a robust interpretation of effectiveness of the hydraulic fracture treatments. In addition to the microseismic monitoring conducted by Schlumberger, three other microseismic monitoring arrays were installed and monitored. The results of the various monitoring efforts varied dramatically and these differences are worthy of examination.
Less Sand May Not Be Enough
Authors: Curry M. , Maloney T. , Woodroof R. , Leonard R. 
Published: February 2010

Abstract
Since the first modern Marcellus completion in Washington County, Pennsylvania in 2004, over 2000 Marcellus wells (horizontal and vertical) have either been permitted or drilled through October 2009 in the Appalachian Basin. The Marcellus play has become one of the most widely discussed plays in the nation, with numerous operators drilling and completing wells in Pennsylvania, West Virginia, Ohio, and New York. While the play is still in its infancy, reported production rates and reserves compare very favorably to other established North American shale plays.
The play's wide geographic range has led to numerous and varied completion schemes being utilized. One primary concern has been determining the optimal size and type of stimulation treatment for a given area. One premise has been that equivalent EUR's should be less of an optimization determinant than production curves, especially early-time production, as revenue generated closer in time to capital spent is worth more than far-into-the-future revenue, and thus completions that lead to high initial production rates are more desirable for optimum rates of return and improved net present values. This paper will describe an unsuccessful attempt to reduce the size (primarily proppant volume used) of the frac treatments, thus lowering the overall completion costs, without sacrificing higher-rate, early-time production. The ultimate conclusion was that a substantial reduction in proppant volume, even though it was replaced with additional fluid volume, had a detrimental effect on fracture volume created, early-time production, and EUR. As this optimization process continues, some wells like the reduced sand volume wells discussed in this paper will require restimulation to maximize overall fracture network creation. Two successful horizontal shale refracture stimulations will also be described in this paper.
Integration of Microseismic and Other Post-Fracture Surveillance With Production Analysis: A Tight Gas Study
Authors: Clarkson C. R. , Beierle J. J. 
Published: February 2010

Abstract
Quantitative production analysis of tight gas reservoirs has historically been a challenge due to complex reservoir characteristics (ex. lateral and vertical heterogeneity, stress-sensitivity of permeability and porosity), induced hydraulic fracture properties in vertical wells (ex. multi-phase flow, conductivity changes, complex fracture geometries), operational complexities (ex. variable back-pressure, liquid-loading) and data quality (infrequent rate or flowing pressure reporting). All of these challenges conspire to make extraction of reservoir (kh and OGIP) and hydraulic fracture properties (xf and fracture conductivity) soley from production/flowing pressure data difficult, often resulting in non-unique answers. In recent history, there has been the added complication that tight gas (and most recently shale gas) reservoirs are now being exploited with horizontal wells, often stimulated using multiple hydraulic fracture stages, which imparts greater complexity on the analysis. Flow regime identification, which is critical to the correct analysis, is more complicated than ever owing to the number of possible flow regimes encountered in such wells.
A case study is presented in which it is demonstrated that modern post-fracture surveillance data, such as microseismic and post-frac production logging, aids in both model identification and model calibration, which is critical to the analysis of hydraulically-fractured horizontal wells completed in tight gas formations. A workflow is presented in which offset vertical wells (to the horizontal wells) are first analyzed to obtain estimates of kh and hydraulic fracture properties, followed by commingled-stage and single-stage production analysis of the multi- (transverse) hydraulic fracture horizontal wells. Microseismic data is incorporated into the analysis of the horizontal wells to 1) understand the orientation and degree of complexity of the induced hydraulic fractures and 2) constrain interpretations of effective hydraulic fracture lengths from production data analysis. It is also demonstrated that once the commingled stage analysis of the horizontal wells is completed, the total interpreted effective hydraulic fracture half-length may be allocated amongst the stages using a combination of production logs and tracer logs.
The primary contribution of the current work is the presentation of workflows, emphasizing the integration of various data sources, to improve production analysis of multi-frac’d horizontal wells completed in tight gas formations. In addition to the workflows, it is shown that a combination of advanced production analysis approaches, including methods analogous to classic pressure transient analysis, production type-curve matching and simulation, may be necessary to arrive at a unique analysis.
Surface Microseismic Monitoring of Slick Water and Nitrogen Fracture Stimulations, Arkoma Basin, Oklahoma
Authors: Hall Morris , Kilpatrick Jo Ellen 
Published: February 2010

Abstract
Surface based microseismic monitoring was performed to assess the effectiveness of slick-water and nitrogen fracture stimulations in a horizontal well with a 3500' lateral drilled in the Arkoma Basin of Oklahoma. Water production from this shale as well as the located events from the microseismic monitoring suggested the fracs were not contained in the target formation and contacted foreign water. The observed distribution of microseismic events suggested that planar fractures were created with varying complexity. The azimuths of the produced trends suggested that a strong influence from the pre-existing natural fractures directed the induced fractures. A direct comparison of the slick-water treatment to the nitrogen treatment revealed multiple advantages with the latter, such as more in-zone events, more energy per event, and more complexity in resulting fractures.
Introduction
The area monitored is located in the Arkoma Basin of Oklahoma, an area where the basin tectonics are inactive, but the weather is not. The surface array used to perform the surface monitoring of the slick-water and nitrogen treatments was designed to locate induced microseismic events by beamforming. The array consisted of 1078 stations of 12 geophones laid out in a radial pattern around the treatment well (Figure1). Although the treatments were two months apart, the array geometry was identical with the exception of removal of 11 stations from the array during the nitrogen treatment. The geophones were buried to a depth of one foot to maximize the signal to noise ratio by reducing the interference of the frequent seasonal rainfall. Cultural sources of noise such as traffic and inherent pad noises were taken into account by surface array design and seismic processing.
Certification, Empowerment, and Intent to Leave Current Position and the Profession Among Critical Care Nurses
Authors: Fitzpatrick Joyce J. , Campo Theresa M. , Graham Gregory , Lavandero Ramón 
Published: February 2010

Background This study was based on the American Association of Critical-Care Nurses’ (AACNs’) interest in determining the value and influence of specialty certification.Objectives To examine relationships between AACN specialty certification and empowerment, and, secondarily, to examine these variables as related to intent to leave the current position and the nursing profession.Methods AACN members were asked to participate in a Web-based survey; 6589 AACN members completed the surveys.Results Perceptions of empowerment differed significantly among nurses certified by AACN and nurses without such certification. Additional analyses revealed significant differences in empowerment related to position, education, salary, ethnicity, sex, intent to leave the current position, and intent to leave the profession. Forty-one percent of the participants indicated intent to leave their current position in the next year; only 6.9% indicated their intent to leave the profession in the next year. Intent to leave current position differed significantly according to age, sex, years of experience, ethnicity, educational level, and certification.Conclusions The value of specialty certification and the importance of empowerment among critical care nurses are affirmed. The next step in the continued journey toward increasing retention of critical care nurses, and thereby improving patient care, is to evaluate existing programs focused on retention and identify needed enhancements.
In Vivo Redundant Function of the 3′ IgH Regulatory Element HS3b in the Mouse
Authors: Bébin Anne-Gaëlle , Carrion Claire , Marquet Marie , Cogné Nadine , Lecardeur Sandrine , Cogné Michel , Pinaud Eric 
Published: February 2010

Abstract
In the mouse, the regulatory region located at the 3′ end of the IgH locus includes four transcriptional enhancers: HS3a, HS1-2, HS3b, and HS4; the first three lie in a quasi-palindromic structure. Although the upstream elements HS3a and HS1-2 proved dispensable for Ig expression and class switch recombination (CSR), the joint deletion of HS3b and HS4 led to a consistent decrease in IgH expression in resting B cells and to a major CSR defect. Within this pair of distal enhancers, it was questionable whether HS3b and HS4 could be considered individually as elements critical for IgH expression and/or CSR. Studies in HS4-deficient mice recently revealed the role of HS4 as restricted to Igμ-chain expression from the pre-B to the mature B cell stage and left HS3b as the last candidate for CSR regulation. Our present study finally invalidates the hypothesis that CSR could mostly rely on HS3b itself. B cells from HS3b-deficient animals undergo normal proliferation, germline transcription, and CSR upon in vitro stimulation with LPS; in vivo Ag-specific responses are not affected. In conclusion, our study highlights a major effect of the global ambiance of the IgH locus; enhancers demonstrated as being strongly synergistic in transgenes turn out to be redundant in their endogenous context.
PE_PGRS Antigens ofMycobacterium tuberculosisInduce Maturation and Activation of Human Dendritic Cells
Authors: Bansal Kushagra , Elluru Sri Ramulu , Narayana Yeddula , Chaturvedi Rashmi , Patil Shripad A. , Kaveri Srini V. , Bayry Jagadeesh , Balaji Kithiganahalli N. 
Published: February 2010

AbstractMycobacterium tuberculosis, the causative agent of pulmonary tuberculosis, infects one-third of the world’s population. Activation of host immune responses for containment of mycobacterial infections involves participation of innate immune cells, such as dendritic cells (DCs). DCs are sentinels of the immune system and are important for eliciting both primary and secondary immune responses to pathogens. In this context, to understand the molecular pathogenesis of tuberculosis and host response to mycobacteria and to conceive prospective vaccine candidates, it is important to understand how cell wall Ags of M. tuberculosis and, in particular, the proline-glutamic acid_polymorphic guanine-cytosine–rich sequence (PE_PGRS) family of proteins modulate DC maturation and function. In this study, we demonstrate that two cell wall-associated/secretory PE_PGRS proteins, PE_PGRS 17 (Rv0978c) and PE_PGRS 11 (Rv0754), recognize TLR2, induce maturation and activation of human DCs, and enhance the ability of DCs to stimulate CD4+ T cells. We further found that PE_PGRS protein-mediated activation of DCs involves participation of ERK1/2, p38 MAPK, and NF-κB signaling pathways. Priming of human DCs with IFN-γ further augmented PE_PGRS 17 or PE_PGRS 11 Ag-induced DC maturation and secretion of key proinflammatory cytokines. Our results suggest that by activating DCs, PE_PGRS proteins, important mycobacterial cell wall Ags, could potentially contribute in the initiation of innate immune responses during tuberculosis infection and hence regulate the clinical course of tuberculosis.
The American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia and Measurement of Symptom Severity
Authors: Wolfe Frederick , Clauw Daniel J. , Fitzcharles Mary‐Ann , Goldenberg Don L. , Katz Robert S. , Mease Philip , Russell Anthony S. , Russell I. Jon , Winfield John B. , Yunus Muhammad B. 
Published: February 2010

AbstractObjectiveTo develop simple, practical criteria for clinical diagnosis of fibromyalgia that are suitable for use in primary and specialty care and that do not require a tender point examination, and to provide a severity scale for characteristic fibromyalgia symptoms.MethodsWe performed a multicenter study of 829 previously diagnosed fibromyalgia patients and controls using physician physical and interview examinations, including a widespread pain index (WPI), a measure of the number of painful body regions. Random forest and recursive partitioning analyses were used to guide the development of a case definition of fibromyalgia, to develop criteria, and to construct a symptom severity (SS) scale.ResultsApproximately 25% of fibromyalgia patients did not satisfy the American College of Rheumatology (ACR) 1990 classification criteria at the time of the study. The most important diagnostic variables were WPI and categorical scales for cognitive symptoms, unrefreshed sleep, fatigue, and number of somatic symptoms. The categorical scales were summed to create an SS scale. We combined the SS scale and the WPI to recommend a new case definition of fibromyalgia: (WPI ≥7 AND SS ≥5) OR (WPI 3–6 AND SS ≥9).ConclusionThis simple clinical case definition of fibromyalgia correctly classifies 88.1% of cases classified by the ACR classification criteria, and does not require a physical or tender point examination. The SS scale enables assessment of fibromyalgia symptom severity in persons with current or previous fibromyalgia, and in those to whom the criteria have not been applied. It will be especially useful in the longitudinal evaluation of patients with marked symptom variability.