bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining Stability of Stored Samples Retrospectively: The Validation of Glycated Albumin
Authors: Nathan David M , Steffes Michael W , Sun Wanjie , Rynders Gregory P , Lachin John M 
Published: October 2010

BACKGROUND
Determining the stability of stored samples for assays that were not available at the time of original collection is problematic. To assess sample stability for a relatively new assay of glycated albumin (GA), we first measured GA in fresh samples and in samples stored for 19–23 years. We then compared the regression of the contemporaneous glycohemoglobin (Hb A1c) values against the GA results from fresh vs stored samples, reasoning that similar slopes and intercepts would provide strong, albeit indirect, support for the stability of the stored samples for GA measurements.

METHODS
We assayed 90 samples frozen for 19–23 years and 90 fresh samples from participants in the Diabetes Control and Complications trial cohort for GA. Hb A1c was measured contemporaneously in fresh samples at each time period. A single normal-errors linear model regressed the Hb A1c values on the GA, with an additional effect for collection period (fresh vs stored for GA) and the interaction of period and GA.

RESULTS
Analysis of the regressions lines between GA and Hb A1c revealed intercepts (3.69 and 2.97 for the fresh and stored samples, respectively) and slopes (0.198 vs 0.187) that were not significantly different (P = 0.182 and P = 0.639, respectively).

CONCLUSIONS
This simple approach can be used to assess the stability of stored samples in new assays. Samples stored for as long as 23 years are suitable for the GA assay.
Direct Serum Assay for MicroRNA-21 Concentrations in Early and Advanced Breast Cancer
Authors: Asaga Sota , Kuo Christine , Nguyen Tung , Terpenning Marilou , Giuliano Armando E , Hoon Dave SB 
Published: October 2010

BACKGROUND
MicroRNAs (miRs) are a class of small noncoding RNAs whose expression changes have been associated with cancer development and progression. Current techniques to isolate miRs for expression analysis from blood are inefficient. We developed a reverse-transcription quantitative real-time PCR (RT-qPCR) assay for direct detection of circulating miRs in serum. We hypothesized that serum concentrations of miR-21, a biomarker increased in breast tumors, would correlate with the presence and extent of breast cancer.

METHODS
The RT-qPCR applied directly in serum (RT-qPCR-DS) assay for circulating miR-21 was tested in sera from 102 patients with different stages of breast cancer and 20 healthy female donors.

RESULTS
The assay was sensitive for detection of miR-21 in 0.625 μL of serum from breast cancer patients. For differentiation of samples from patients with locoregional breast cancer from those from healthy donors, the odds ratio was 1.796 and the area under the curve was 0.721. In a multivariate analysis that included standard clinicopathologic prognostic factors, high circulating miR-21 concentrations correlated significantly (P &lt; 0.001) with visceral metastasis.

CONCLUSIONS
A novel RT-qPCR-DS can improve the efficiency of miR assessment. Use of this assay to detect circulating miR-21 has diagnostic and prognostic potential in breast cancer.
Epigenetic regulation of protein glycosylation
Authors: Zoldoš Vlatka , Grgurević Srđana , Lauc Gordan 
Published: October 2010

AbstractProtein N-glycosylation is an ancient metabolic pathway that still exists in all three domains of life (Archaea, Bacteria and Eukarya). The covalent addition of one or more complex oligosaccharides (glycans) to protein backbones greatly diversifies their structures and makes the glycoproteome several orders of magnitude more complex than the proteome itself. Contrary to polypeptides, which are defined by a sequence of nucleotides in the corresponding genes, the glycan part of glycoproteins are encoded in a complex dynamic network of hundreds of proteins, whereby activity is defined by both genetic sequence and the regulation of gene expression. Owing to the complex nature of their biosynthesis, glycans are particularly versatile and apparently a large part of human variation derives from differences in protein glycosylation. Composition of the individual glycome appears to be rather stable, and thus differences in the pattern of glycan synthesis between individuals could originate either from genetic polymorphisms or from stable epigenetic regulation of gene expression in different individuals. Studies of epigenetic modification of genes involved in protein glycosylation are still scarce, but their results indicate that this process might be very important for the regulation of protein glycosylation.
Constitutive Equations of Sheet Stamping Steel Based on DIC Measurement
Authors: Jiang J. H. , Wang Y. H. , Yang L. X. 
Published: October 2010

Abstract
Digital image correlation (DIC) is a full-field and non-contact technique for the measurement of displacement and strain. It has considerately high precision for measuring large deformation. Based on the experimental data of true stress-strain measured by DIC combined with the data from a tensile test machine, the methodology for establishing a constitutive model for sheet stamping steel is presented in this paper. The procedure is demonstrated by developing the constitutive equations for the DP600 sheet metal with a cold rolled advanced high-strength steel, designed predominately for the automotive industry, with enhanced ductility and formability. To verify the constitutive equations, a force-displacement diagram is simulated by finite element analysis (FEA). A comparison of force-displacement diagram obtained by FEA and the data from the tensile test machine shows that the method for establishing the constitutive equations for stamping steel presented in this paper is reliable and has reasonable accuracy. As a material constitutive model, the establishment of constitutive equations of stamping steel provides the experimental validation for FEA. It is particularly valuable when evaluating non-linear numerical simulation of the stamping process of structural parts with complicated geometry.
Preterm birth does not affect bone mineral density in young adults
Authors: Breukhoven Petra E , Leunissen Ralph W J , de Kort Sandra W K , Willemsen Ruben H , Hokken-Koelega Anita C S 
Published: October 2010

ObjectivePrevious studies showed conflicting data on the effect of prematurity on bone mineral density (BMD) in infants and children. Only a few studies investigated the long-term effects of prematurity on BMD in early adulthood. The objective of our study was to assess the long-term effects of preterm birth on BMD of the total body (BMDTB), lumbar spine (BMDLS) and bone mineral apparent density of the LS (BMADLS).DesignCross-sectional study.MethodsIt consists of two hundred and seventy-six healthy subjects without serious postnatal complications, aged 18–24 years. The contribution of gestational age to the variance in BMD in young adulthood and the differences in BMD between 151 subjects born preterm (median gestational age 32.2 weeks (interquartile range (IQR) 30.3–34.0)) and 125 subjects born at term (median gestational age 40.0 weeks (IQR 39.0–40.0)) were investigated. BMD was determined by dual-energy X-ray absorptiometry.ResultsThere were no significant linear correlations between gestational age and BMDTB(r=0.063,P=0.30), BMDLS(r=0.062,P=0.31) and BMADLS(r=0.069,P=0.26). Also after adjustment for possible confounders, gestational age was no significant contributor to the variance in BMDTB(P=0.27), BMDLS(P=0.91) and BMADLS(P=0.87). No significant differences were found between preterm and term subjects with regard to BMDTB, BMDLSand BMADLS.ConclusionIn our cohort of 276 young adults, aged 18–24 years, gestational age was not a significant determinant in the variance of BMD. Preterm birth without serious postnatal complications is not associated with a lower BMD in young adulthood.
Induction Chemotherapy for Head and Neck Cancer: Recent Data
Authors: Vokes Everett E. 
Published: October 2010

Abstract
The addition of chemotherapy to radiotherapy in the treatment of locally advanced squamous cell carcinoma of the head and neck (SCCHN) patients improves survival. Meta-analyses of randomized trials have indicated that the benefit of this approach is associated with the timing of chemotherapy administration. It has been demonstrated that the greatest survival benefit over locoregional treatment alone is seen with the concurrent administration of chemotherapy and radiotherapy. However, sequential chemotherapy administration, in the form of induction chemotherapy followed by radiotherapy or concurrent chemoradiotherapy, has been successful as a strategy for organ function preservation in patients with potentially resectable SCCHN. In addition, a meta-analysis of trials using platinum and 5-fluorouracil (PF)-containing induction regimens demonstrated a significant survival benefit for this approach over locoregional treatment alone in locally advanced disease. In recent years, the introduction of the taxanes into induction chemotherapy has provided physicians with more active regimens. The triplet combination induction regimen of docetaxel, cisplatin, and 5-fluorouracil has been shown to be more effective in prolonging survival than the doublet PF. Current trials are testing whether the addition of induction chemotherapy to standard concomitant chemoradiotherapy is superior to concomitant chemoradiotherapy alone.
Induction Chemotherapy Before Chemoradiotherapy in Locally Advanced Head and Neck Cancer: The Future?
Authors: Paccagnella Adriano , Mastromauro Cataldo , D'Amanzo Paola , Ghi Maria Grazia 
Published: October 2010

Abstract
There is increasing interest in the use of induction chemotherapy before concurrent chemotherapy and radiotherapy in the treatment of locally advanced head and neck cancer. A modest but significant improvement in survival has been observed with cisplatin and 5-fluorouracil (PF) induction before radiotherapy over that seen with radiotherapy alone. The addition of docetaxel to the PF regimen (TPF) appears to provide further survival benefits. The phase II part of a phase II/III trial compared three cycles of TPF induction chemotherapy before concomitant PF chemoradiotherapy with PF chemoradiotherapy alone in 101 patients with locally advanced stage III–IV head and neck cancer. The incidences of hematologic and nonhematologic toxicities during concurrent chemoradiotherapy were not higher in the TPF plus chemoradiotherapy group, and the feasibility of chemoradiotherapy was not compromised. Radiologically evaluated complete response rates at 6–8 weeks from the end of chemoradiotherapy (the primary endpoint) were 21% (95% confidence interval [CI], 11%–36%) with chemoradiotherapy alone and 50% (95% CI, 35%–65%; p = .004) with TPF plus chemoradiotherapy. A median overall survival time of 33.3 months and a 1-year survival rate of 78% were observed with chemoradiotherapy alone, whereas the median survival time was 39.6 months in the TPF plus chemoradiotherapy group, with a 1-year survival rate of 86%. To conclude, increasing evidence suggests that TPF induction chemotherapy improves clinical response and does not compromise subsequent chemoradiotherapy. The results of the ongoing phase III part of the phase II/III study should provide further information about the efficacy and safety of this approach for patients with locally advanced head and neck cancer.
TPF: A Rational Choice for Larynx Preservation?
Authors: Calais Gilles 
Published: October 2010

Abstract
For many years, the standard approach for the treatment of resectable squamous cell carcinoma of the head and neck was surgery, with or without subsequent radiotherapy. However, the morbidity associated with this approach, particularly for patients requiring total laryngectomy, can severely impair a patient's quality of life. The finding that patients whose tumors responded to chemotherapy showed a good response to subsequent radiotherapy opened up the possibility of a new organ-preserving management strategy for patients with resectable disease. Randomized studies demonstrated that induction chemotherapy with a cisplatin–5-fluorouracil (5-FU) doublet (PF) prior to radiotherapy enabled larynx preservation in a substantial proportion of patients, compared with surgery plus radiotherapy, without compromising survival. The benefit in terms of larynx preservation when using platinum-based doublet induction chemotherapy followed by radiotherapy, compared with concurrent chemotherapy and radiotherapy, is less clear, although the sequential approach appears to be better tolerated. Adding the taxane docetaxel to PF, to create the TPF triplet regimen, led to significantly higher larynx preservation and laryngectomy-free survival rates than with the PF doublet. TPF is now the accepted standard induction chemotherapy regimen for future clinical trials in resectable disease. Methods for improving postinduction treatment strategies are being explored.
Candidates for Larynx Preservation: The Next Step?
Authors: Lefebvre Jean-Louis 
Published: October 2010

Abstract
Nonsurgical treatment approaches to enable larynx preservation in patients who would otherwise undergo laryngectomy have evolved over recent years. Randomized trials have demonstrated that concurrent chemotherapy and radiotherapy is more effective than doublet cisplatin and 5-fluorouracil (5-FU) (PF)-based induction chemotherapy and radiotherapy in enabling larynx preservation. However, concurrent chemotherapy and radiotherapy is also associated with more toxicities than induction PF followed by radiotherapy. The triplet induction regimen of docetaxel, cisplatin, and 5-FU (TPF) is more effective than PF and is now considered to be the standard induction chemotherapy regimen for future larynx preservation trials. Manipulating the postinduction treatment regimen may help to improve larynx preservation rates, and possibly survival, and the use of concurrent chemoradiotherapy and radiotherapy plus the epidermal growth factor receptor inhibitor cetuximab has been investigated in this setting. Determining the most effective treatment approach for larynx preservation will involve conducting a trial comparing concurrent chemotherapy and radiotherapy with sequential TPF induction chemotherapy followed by either radiotherapy or cetuximab plus radiotherapy. Collaboration among international groups is required to assess which approach would be most beneficial in terms of larynx function preservation, disease control, and survival.
Nuclear-Magnetic-Resonance Petrophysics in Thin Sand/Shale Laminations
Authors: Minh Chanh Cao , Sundararaman Padmanabhan 
Published: October 2010

Summary
We discuss the use of nuclear-magnetic-resonance (NMR) logging in the petrophysical evaluation of thin sand/shale laminations. NMR helps detect thin beds, determine fluid type, establish the hydrocarbon type and volume if hydrocarbon is present, and, finally, determine the permeability of the sand layers (as opposed to that of the sand/shale system).
Experiments were conducted on samples of 100% sand, 100% clay, and sand/clay layers with an NMR-logging tool at surface to verify the characteristic T2 bimodal relaxation distribution often observed in NMR logs that are acquired in thin beds. From the bimodal distribution, it is often possible to determine a cutoff to separate the productive sand layers from the shale layers and, with it, the porosity fraction of each component. Subsequently, the sand fraction, or net/gross ratio, can be estimated assuming that the 100%-sand porosity is known. Because gas, oil, and water have different NMR properties, fluid-typing techniques such as 2D NMR offer useful insights into the fluid type and properties in thin-layer sands. Because the laminations thickness is often less than the antenna aperture, the estimated permeability of the sand/ shale system will undercall the true permeability of the sand layers only. In this case, their permeability can be estimated quickly from Darcy's fluid-flow model.
We show examples of thin sand/shale laminations that are oil-bearing and gas-bearing. In each case, the NMR detection was verified against borehole-imaging logs, and the fluid type in the sands was determined from multidimensional NMR analysis. The derived hydrocarbon volume was then compared with the results estimated from a triaxial induction tool. Permeability of the sand layers was also computed and compared to that of nearby thick sands. Core data in one well was used to validate NMR detection, porosity, permeability, and net sand thickness.
Quantitative Analysis of Mud Losses in Naturally Fractured Reservoirs: The Effect of Rheology
Authors: Majidi R.. , Miska S.Z.. Z. , Yu M.. , Thompson L.G.. G. , Zhang J.. 
Published: October 2010

Summary
Significant fluid loss while drilling through fractured formations is a major problem for drilling operations. From field experience, we know that the type and rheological parameters of the drilling fluid have a strong impact upon the rate and volume of losses.
A mathematical model for Herschel-Bulkley [yield-power-law (YPL)] drilling-fluid losses in naturally fractured formations is presented. As a result, the effect of rheological properties of drilling fluid such as yield stress and shear-thinning/-thickening effect (flow-behavior index) on mud losses in fractured formations is investigated. We found that the yield stress can control the ultimate volume of losses while the shear-thinning effect can tremendously decrease the rate of losses. Therefore, mud losses in fractures can be minimized by optimizing the rheology of the drilling fluid properly.
The model also allows for quantitative analysis of losses that take into account fluid rheology to characterize the fractures. Hydraulic aperture of conductive fractures can be obtained by continuously monitoring mud losses and fitting field records of mud losses to the model. The proposed model is very useful not only for drilling applications but also for well-completion design and fractured-reservoir-characterization purposes. To examine the validity of the model, a practical application of the proposed technique is demonstrated through a field example of mud-loss measurements in a fractured well in the Gulf of Mexico.
Equation-of-State-Based Downhole Fluid Characterization
Authors: Zuo Julian Y. , Zhang Dan , Dubost Francois , Dong Chengli , Mullins Oliver C. , O’Keefe Michael , Betancourt Soraya S. 
Published: October 2010

Summary
Downhole fluid analysis (DFA), together with focused-sampling techniques and wireline-formation-tester (WFT) tools, provides real-time measurements of reservoir-fluid properties such as the compositions of four or five hydrocarbon components/groups and gas/oil ratio (GOR). With the introduction of a new generation of DFA tools that analyze fluids at downhole conditions, the accuracy and reliability of the DFA measurements are improved significantly. Furthermore, downhole measurements of live-fluid densities are integrated into the new tools. Direct pressure and temperature measurements of the flowline ensure capture of accurate fluid conditions. To enhance these advanced features further, a new method of downhole fluid characterization based on the equation-of-state (EOS) approach is proposed in this work.
The motivation for this work is to develop a new approach to maximize the value of DFA data, perform quality assurance or quality control of DFA data, and establish a fluid model for DFA log predictions along with DFA fluid profiling. The basic inputs from DFA measurements are weight percentages of CO2, C1, C2, C3–C5 and C6+, along with live-fluid density and viscosity. A new method was developed in this work to delump and characterize the DFA measurements of C3–C5 (or C2–C5) and C6+ into full-length compositional data. The full-length compositional data predicted by the new method were compared with the laboratory-measured gas chromatograph data up to C30+ for more than 1,000 fluids, including heavy oil, conventional black oil, volatile oil, rich gas condensate, lean gas condensate, and wet gas. These fluids have a GOR range of 8–140,000 scf/STB and a gravity range from 9 to 50°API. A good agreement was achieved between the delumped and gas-chromatograph compositions.
In addition, on the basis of the delumped and characterized full-length compositional data, EOS models were established that can be applied to predict fluid-phase behavior and physical properties by virtue of DFA data as inputs. The EOS predictions were validated and compared with the laboratory-measured pressure/volume/temperature (PVT) properties for more than 1,000 fluids. The GOR, formation-volume factor, density, and viscosity predictions were in good agreement with the laboratory measurements. The established EOS model then was able to predict other PVT properties, and the results were compared with the laboratory measurements in good agreement.
Consequently, the established EOS models have laid a solid foundation for DFA log predictions in DFA fluid profiling, which has been integrated successfully with DFA measurements in real time to delineate compositional and asphaltene gradients in oil columns and to determine reservoir connectivity. The latter results are beyond the scope of this work and have been given in separate technical papers.
Stress Amplification and Arch Dimensions in Proppant Beds Deposited by Waterfracs
Authors: Warpinski N.R.. R. 
Published: October 2010

Summary
Equations and a procedure have been developed to calculate the excess stress induced on a proppant dune that is deposited by a waterfrac with poor proppant-transport characteristics. This method also calculates the dimensions of an arch region that forms above the bed. Stresses on the proppant at the top of such a dune are much greater than usually considered because of the need to support a wide proppant bed and the arch, suggesting that crushing and embedment are likely. The arch region itself is an extremely-high-conductivity pathway that may provide overall benefit in terms of cleanup and production, but may also aid sand production.
Cementing Casing Strings Across Salt Zones: An Overview of Global Best Practices
Authors: Hunter Bill , Tahmourpour Farzad , Faul Ronnie 
Published: October 2010

Summary
The global oil and gas industry is being challenged to increase production to meet the rising world energy demand. One of the key areas now being explored and developed to meet this demand are reserves below massive salt formations.
To reach these reserves, it is necessary to drill through and case off the salt. Casing and cementing operations in such salt zones can pose particular challenges, ranging from the effect of salt dissolution on cement-slurry properties to the potential dangers presented by salt creep to the integrity of the well and the need to plan for contingencies for potential zones of overpressure or lost circulation. This paper examines and explores the challenges inherent with cementing across salt zones in the global arena.
The current best practices for cementing casing strings across salt zones in some of the major subsalt basins of the world, including the North Sea and the Gulf of Mexico, are detailed and discussed.
This work should assist those tasked with the construction of wells that have to penetrate significant salt formations to achieve their objectives safely and reliably.