bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toward standardization of carbohydrate-deficient transferrin (CDT) measurements: II. Performance of a laboratory network running the HPLC candidate reference measurement procedure and evaluation of a candidate reference material
Authors: Helander Anders , Wielders Jos P.M. , Jeppsson Jan-Olof , Weykamp Cas , Siebelder Carla , Anton Raymond F. , Schellenberg François , Whitfield John B. 
Published: October 2010

Abstract
Carbohydrate-deficient transferrin (CDT) is a descriptive term used for a temporary change in the transferrin glycosylation profile caused by alcohol, and used as a biomarker of chronic high alcohol consumption. The use of an array of methods for measurement of CDT in various absolute or relative amounts, and sometimes covering different transferrin glycoforms, has complicated the comparability of results and caused confusion among medical staff. This situation prompted initiation of an IFCC Working Group on CDT standardization. This second publication of the WG-CDT covers the establishment of a network of reference laboratories running a high-performance liquid chromatography (HPLC) candidate reference measurement procedure, and evaluation of candidate secondary reference materials. The network laboratories demonstrated good and reproducible performance and thus can be used to assign target values for calibrators and controls. A candidate secondary reference material based on native human serum lyophilized with a cryo-/lyoprotectant to prevent protein denaturation was found to be commutable and stable during storage. A proposed strategy for calibration of different CDT methods is also presented. In an external quality assurance study involving 66 laboratories and covering the current routine CDT assays (HPLC, capillary electrophoresis and immunoassay), recalculation of observed results based on the nominal values for the candidate calibrator reduced the overall coefficient of variation from 18.9% to 5.5%. The logistics for distribution of reference materials and review of results were found to be functional, indicating that a full reference system for CDT may soon be available.
Clin Chem Lab Med 2010;48:1585–92.
Introduction of a new cobalamin (vitamin B12) assay: lessons from a flawed validation study
Authors: van Rossum André P. , Gunnewiek Jacqueline Klein , Verheijen François M. , Vlasveld L. Tom , Castel Ad , Fouraux Michael A. 
Published: October 2010

Abstract

Background: Plasma vitamin B12 [cobalamin (Cbl)] concentrations are usually measured as a screening marker for vitamin B12 deficiency. Siemens Healthcare Diagnostics has introduced Cbl assays for various platforms, i.e., the immulite (IML) 2000 and 2500. In our laboratories, regular validation studies for the IML 2500 were conducted and showed acceptable quality specifications. After the introduction of the IML 2500 Cbl assay, clinicians in the department of internal medicine reported an increased frequency of patients with Cbl-concentrations less than 148 pmol/L.

Methods: In order to investigate this claim from the clinicians, we retrospectively analyzed the internal and external quality control (QC) of the Cbl assay. In addition, the monthly patient means for the Cbl assay were analyzed both before and after the introduction of the new Cbl assay.

Results: No abnormalities were found in the internal and external QCs. However, the monthly patient means for the Cbl assay showed a statistically significant decrease in cobalamin concentrations. Siemens acknowledged the problems and formulated a new Cbl assay, which was subsequently validated in our laboratories and showed equivocal Cbl results when compared to the IML 2000 Cbl assay.

Conclusions: We report a flawed validation study conducted by the manufacturer that resulted in an undetected analytical problem in the IML 2500 Cbl assay, its subsequent introduction on the market, the final recognition of the poor performance of the assay by our clinicians, and the eventual resolution by the manufacturer. Hence, it emphasizes the utmost importance for thorough comparison between assays over the entire measurement range, even when both assays are produced by the same manufacturer.
Interlaboratory study of free monoclonal immunoglobulin light chain quantification
Authors: Vávrová Jaroslava , Maisnar Vladimír , Tichý Miloš , Friedecký Bedřich , Čermáková Zdeňka , Dastych Milan , Gottwaldová Jana , Kučera Petr , Krotká Jarmila , Racek Jaroslav , Ženková Jana , Schneiderka Petr , Lochman Pavel , Zima Tomáš , Benáková Hana , Büchler Tomáš , Spáčilová Jana , Hájek Roman , Palička Vladimír 
Published: October 2010

Abstract

Background: Quantification of monoclonal immunoglobulin free light chains (FLCs) in serum is used increasingly in clinical practice for the diagnosis, prognostic assessment, and treatment monitoring of monoclonal gammopathies. It is used as an adjunct to standard serum protein electrophoresis and immunofixation. However, methods for FLC quantification need further standardization and validation.

Methods: The Czech Myeloma Group and the Czech Society of Clinical Biochemistry have initiated an interlaboratory study where six laboratories collaborating with the primary myeloma treatment centres measured FLC concentrations in 12 serum samples from patients with monoclonal gammopathies.

Results: Repeatability of the measurements in five laboratories was calculated based on differences between the results of duplicate measurements. We found that repeatability depended more on the laboratory than on the device used for measurement.

Conclusions: The study revealed several weak points in the methodology, including the need for a uniform sample dilution procedure. Interlaboratory reproducibility was comparable with values achieved in the NEQAS programme. Because the κ/λ ratio cannot be measured with high precision, κ and λ FLC concentrations should be used where possible. Due to its impact on the clinical management of patients with gammopathy, FLC quantification needs to become a part of the regular quality control cycle in myeloma centres.
Comparison of the cortisol responses to testing with two doses of ACTH in patients with suspected adrenal insufficiency
Authors: Dekkers O M , Timmermans J M , Smit J W A , Romijn J A , Pereira A M 
Published: October 2010

ObjectivesTo compare the cortisol response of the 1 μg and the 250 μg ACTH test in a large study of patients with suspected adrenal insufficiency.DesignRetrospective cohort study.MethodsSingle center study assessing patients tested for primary or secondary adrenal insufficiency between January 2004 and December 2007, who had both ACTH tests (1 μg and 250 μg; n=207) within a time interval of 6 weeks. Test results were compared with a Bland–Altman plot and McNemar's test.ResultsThe mean difference between the cortisol responses in the two ACTH tests was 26 nmol/l (95% confidence interval (CI) 13, 40), showing a marginally higher response for the 250 μg test. The diagnostic performances of the two tests were similar (P=0.49) using a cut-off value for cortisol of 550 nmol/l. A normal cortisol response to the 1 μg ACTH test could be accompanied by an abnormal response to the 250 μg ACTH test, and vice versa.ConclusionThis study shows that the 1 μg and the 250 μg ACTH tests have comparable cortisol responses in patients with suspected adrenal insufficiency. However, in individual patients, the difference in cortisol response to the two tests can be substantial, and the response in the 250 μg test is not invariably higher than the response in a 1 μg test.
Defining Genetic Factors That Modulate Intergenerational CAG Repeat Instability inDrosophila melanogaster
Authors: Jung Joonil , van Jaarsveld Marijn T M , Shieh Shin-Yi , Xu Kexiang , Bonini Nancy M 
Published: November 2010

AbstractTrinucleotide repeat instability underlies &gt;20 human hereditary disorders. These diseases include many neurological and neurodegenerative situations, such as those caused by pathogenic polyglutamine (polyQ) domains encoded by expanded CAG repeats. Although mechanisms of instability have been intensely studied, our knowledge remains limited in part due to the lack of unbiased genome-wide screens in multicellular eukaryotes. Drosophila melanogaster displays triplet repeat instability with features that recapitulate repeat instability seen in patients with disease. Here we report an enhanced fly model with substantial instability based on a noncoding 270 CAG (UAS–CAG270) repeat construct under control of a germline-specific promoter. We find that expression of pathogenic polyQ protein modulates repeat instability of CAG270 in trans, indicating that pathogenic-length polyQ proteins may globally modulate repeat instability in the genome in vivo. We further performed an unbiased genetic screen for novel modifiers of instability. These studies indicate that different aspects of repeat instability are under independent genetic control, and identify CG15262, a protein with a NOT2/3/5 conserved domain, as a modifier of CAG repeat instability in vivo.
Evaluation of the Patient Health Questionnaire-9 Item for Detecting Major Depression Among Adolescents
Authors: Richardson Laura P. , McCauley Elizabeth , Grossman David C. , McCarty Carolyn A. , Richards Julie , Russo Joan E. , Rockhill Carol , Katon Wayne 
Published: November 2010

OBJECTIVE:
The purpose of this study was to examine the performance characteristics and validity of the Patient Health Questionnaire-9 Item (PHQ-9) as a screening tool for depression among adolescents.

METHODS:
The PHQ-9 was completed by 442 youth (aged 13–17 years) who were enrolled in a large health care–delivery system and participated in a study on depression outcomes. Criterion validity and performance characteristics were assessed against an independent structured mental health interview (the Child Diagnostic Interview Schedule [DISC-IV]). Construct validity was tested by examining associations between the PHQ-9 and a self-report measure of functional impairment, as well as parental reports of child psychosocial impairment and internalizing symptoms.

RESULTS:
A PHQ-9 score of 11 or more had a sensitivity of 89.5% and a specificity of 77.5% for detecting youth who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for major depression on the DISC-IV. Receiver-operator-curve analysis revealed that the PHQ-9 had an area under the curve of 0.88 (95% confidence interval: 0.82–0.94), and the cut point of 11 was optimal for maximizing sensitivity without loss of specificity. Increasing PHQ-9 scores were significantly correlated with increasing levels of functional impairment, as well as parental report of internalizing symptoms and psychosocial problems.

CONCLUSIONS:
Although the optimal cut point is higher among adolescents, the sensitivity and specificity of the PHQ-9 are similar to those of adult populations. The brief nature and ease of scoring of this instrument make this tool an excellent choice for providers and researchers seeking to implement depression screening in primary care settings.
Incidence of Morbidity From Penetrating Palate Trauma
Authors: Hennelly Kara , Kimia Amir , Lee Lois , Jones Dwight , Porter Stephen C. 
Published: November 2010

BACKGROUND:The true rate of neurologic sequelae and infection from penetrating palatal trauma in children is unknown, which leads to significant variation in testing and treatment.OBJECTIVES:To (1) determine the incidence of stroke and infection in well-appearing children with penetrating palatal trauma and (2) describe patterns of testing and treatment for uncomplicated palatal trauma.METHODS:We assembled a retrospective cohort of children aged 9 months to 18 years with palatal trauma seen in the emergency department (ED) at a tertiary care pediatric hospital. Patients met the following definition: well-appearing with normal neurologic examination and a palate laceration but no findings requiring immediate operative care. Stroke was defined as any abnormal neurologic examination secondary to palatal trauma. Infection was defined as cellulitis or abscess secondary to palatal injury. All abnormal computed tomographic angiography (CTA) findings, except for free air, were considered positive and potentially significant.RESULTS:We identified 1656 potential subjects. A total of 995 of 1656 subjects were screened, and 205 of 995 met the case definition. A total of 122 of 205 had follow-up through at least 1 week after injury. The incidence of stroke in our study population was 0% (95% confidence interval [CI]: 0–2.5). One of 116 patients developed infection, for an incidence of 0.9% (95% CI: 0–5.3). A total of 90 of 205 (44%) subjects had CTA scans; the results of 9 (10%) were positive. No patients with positive CTA findings required operative care. No patients received anticoagulant medications.CONCLUSIONS:The incidence of morbidity from penetrating palatal trauma in the well-appearing child is extremely low. Diagnostic evaluation in the ED did not prompt clinical interventions other than antibiotics.
Nanocomposite of Bi2Te3 with Metal Inclusions for Advanced Thermoelectric Applications
Authors: Santhanam Sumithra , Takas Nathan J. , Misra Dinesh , Poudeu Pierre F. P. , Stokes Kevin L. 
Published: October 2010

AbstractRecent experimental and theoretical studies have shown that the thermal to electrical power conversion efficiency (as measured by the thermoelectric figure of merit) can be enhanced in nanocomposite materials. Primarily, these efforts to improve the thermoelectric efficiency rely on reducing the lattice thermal conductivity through nanostructuring of the materials or the introduction of a second nanometer-scale phase into the composite material. Here, we show that the inclusion of semimetal nanoparticles into bismuth telluride (Bi2Te3) can result in both an increase in the electronic transport properties (so called "power factor") as well as a decrease in lattice thermal conductivity. The effect of different volume fractions of Bi nanoinclusions (3% and 5%) on the thermal and electrical properties of the composite are reported. A marginal increase in the thermoelectric figure of merit is achieved for 3% metal nanoinclusion, whereas a significant improvement in the figure of merit could be achieved for 5% nanoinclusions in the Bi2Te3 thermoelectric matrix.
Estimate of Hydrogen Density at Starting Point for Crevice Corrosion and Cracking of Cold Rolled Type 304 Stainless Steel
Authors: Kajikawa Shunji , Isobe Yasuaki , Kuromiya Akio , Okido Masazumi 
Published: October 2010

AbstractIn the past work of authors, a cold rolled type304 stainless steel pipe with shot peening was prepared. A crevice was created between the outside of the pipe and an O-ring, and the pipe was applied stress by press fitting another part. Cracking from a crevice corrosion pit was observed in a chloride environment, and it was presumed to be Hydrogen Embrittlement-Stress Corrosion Cracking（HE-SCC）. Provided that the crack is caused by HE-SCC､it is thought that hydrogen is generated by corrosion reaction and the SUS304 pipe absorbs it more than its critical level. Generally, the hydrogen distribution in the steel is analyzed in the condition that the hydrogen concentration of the environment is constant as the high-pressure hydrogen gas environment etc. In the case of HE-SCC described above, however, the hydrogen concentration is presumed to change with pitting growth, and there is no example of analysis in such condition.
In this work, cyclic corrosion tests were conducted using the samples with no press-fitting part. The hydrogen density at the initiation point of crevice corrosion and cracking was estimated by following technique. First, the amount of hydrogen diffused from the corrosion pit was measured using Thermal Desorption Spectroscopy（TDS ）, and the number of pits was measured. Then, the average hydrogen quantity in a pit was derived.
On the other hand, it is thought that hydrogen is generated by the hydrolysis of a metallic salt and the cathode reaction of the hydrogen ion in the pit. Therefore, the amount of the hydrogen is proportional to the quantity of corrosion amount. Then, assuming that pitting corrosion takes the form of half sphere shape and grows with time, the simulation model was made that the hydrogen absorbed and diffused from the pit surface with the development of corrosion. The profile of the hydrogen density in SUS304 from pit initiation till crack initiation was calculated based on this model. The calculated profile of the hydrogen density was compared with the amount of hydrogen measured by cyclic corrosion test. As a result, the hydrogen concentration at the crack starting point was derived 0.3ppm. At this density level, He-SCC can occur in high strength SUS304.
Electrical Conductivity Relaxation Study of Solid Oxide Fuel Cell Cathodes using Epitaxial (001)-Oriented Strontium-Doped Lanthanum Manganite Thin Films
Authors: Yan Lu , Kavaipatti Balasubramaniam , Wang Shanling , Du Hui , Salvador Paul 
Published: October 2010

AbstractEpitaxial single-crystal films of La0.7Sr0.3MnO3 (100) having smooth surface morphology were deposited on SrTiO3 (100) substrates by pulsed laser deposition (PLD). Electrical conductivity relaxation (ECR) measurements were carried out at elevated temperatures over a range of absolute oxygen pressures to determine the oxygen surface exchange coefficient. Steady-state conductivity data of the thin films show good agreement with the bulk material's properties. The values of the oxygen exchange coefficients (Kchem) are found to be similar for both oxidation and reduction process between 50 and 500 mTorr O2. The activation energy (Ea) of Kchem is 1.00±0.27 eV at temperatures above 600 °C and Kchem (T=612°C)≈1.2×10-6 cm/s.
(100) Oriented Sputter-deposited Pt Thin Films on MgO/Fe Composite Bilayers using SiO2/Si substrates With Addition of O2 During Pt Sputtering
Authors: Nakagawa Shigeki , Nakano Hiroshi , Murashima Yuji , Komaki Kazuki , Matsumoto Tatsuro , Wang ChongE 
Published: October 2010

AbstractPerovskite type oxide thin films have attracted a lot of attention, because they are essential materials which will be used for various electric devices such as ferroelectric random access memory (FeRAM) and tunable filter devices. When the materials are used for such capacitive devices, bottom electrode layers for oxide films are very important, since they significantly affect the crystallinity of the oxide films. Platinum (Pt) is one of the well known bottom electrode materials used for the oxide thin films. Pt provides also better nucleation sites for such perovskite materials due to small lattice misfit. Since dielectric properties of ferroelectric films are originated from the displacement of ions in a crystal along the c-axis direction, c-axis oriented ferroelectric thin films are required to attain better dielectric properties. (100) oriented Pt layers are required to attain c-axis oriented perovskite type ferroelectric films. In our previous report, we succeeded in preparing (100)-oriented Pt thin films with thickness of 20 nm on SiO2/Si substrate at substrate temperature Ts above 400 °C using MgO (100) buffer layers which deposited on Fe (100) seed layers. However, the growth of Pt(111) texture appeared when the thickness was increased from 20 nm to 100 nm, since (100) texture has relatively higher surface energy than (111) closely packed texture for Pt surface. It suggested that surface energy of the films changed during the deposition. In order to keep the surface energy, addition of O2 gas was performed during Pt deposition. Pt thin films with (100) preferred orientation with thickness above 100 nm were deposited on the (100) oriented MgO layer prepared on very thin seed Fe layers deposited on SiO2/Si substrates at Ts of 500 °C by facing-targets sputtering. It was also succeeded to attain (100) oriented perovskite oxide layer when they were deposited on the Pt(100)/Mg(100)/Fe/SiO2/Si underlayer.
Structure and Transport Properties of Sr0.75-xCaxY0.25Co0.25Mn0.75O3-δ (0 ≤ x ≤ 0.6)
Authors: Galeeva Alexandra , Napolsky Philipp , Istomin Sergey , Gippius Andrey , Khokhlov Dmitry 
Published: October 2010

AbstractNew complex oxide Sr0.75-xCaxY0.25Co0.25Mn0.75O3-δ with a perovskite-like structure has been synthesized and characterized. DC and AC transport properties of ceramic samples have been studied in the temperature range 4.2K – 1173K. DC conductivity data at T > 300K are discussed in terms of the small polaron hopping model. Dependence of the polaron activation energy on the calcium content is found to correlate with the change of structural distortion parameters. Both the temperature dependence of DC conductivity and the frequency dependence of the real part of the admittance reveal hopping transport at low temperatures.
Synthesis of Biocompatible Magnetic Iron Oxide (γ-Fe2O3 and Fe3O4) Nanoparticles by a Modified Polyol Process for Biomedical Applications
Authors: Basina Georgia , Panagiotopoulos Ioannis , Devlin Eamonn , Hadjipanayis George , Colak Levent , Hadjipanayis Constantinos , Mao Hui , Diamantopoulos Georgios , Fardis Michael , Papavasileiou Georgios , Niarchos Dimitrios , Tzitzios Vasilis 
Published: October 2010

AbstractHighly crystalline superparamagnetic Fe3O4 nanoparticles coated by poly-vinylpyrrolidone (PVP) were prepared by simultaneous thermal decomposition of ferrous and ferric inorganic salts in polyethylene glycol (PEG) with molecular weight 200. The magnetic particles have a diameter in the range of 8-15 nm, and after exchange with citric acid diammonium salt, they transform into very stable super hydrophilic colloidal solutions. The presence of magnetite phase was confirmed using powder X-rays diffraction (XRD) and Mössbauer spectroscopy, while thermogravimetric analysis and FT-IR spectroscopy confirmed the presence of PVP or citrate anions on the nanoparticles surface. The magnetic properties revealed superparamagnetic behavior, with the composite material showing a saturation magnetization up to 57 emu/g. The Fe3O4 nanoparticles prepared by this modified polyol process are suitable for biomedical applications because of the biocompatibility of citrate anions. Magnetic hyperthermia experiments in neutral water solutions shows that the particles induce fast heating rates with specific absorption rate (SAR) values which reached 57.53 W/gFe, when the concentration of iron is 11.2 mgFe/ml.
Effects of He-irradiation on the Metal-to-insulator Transition of Vanadium Dioxide Nanoclusters
Authors: Karl Helmut , Peng Jing , Stritzker Bernd 
Published: October 2010

AbstractIn this work nanoclusters of vanadium dioxide (VO2) buried in 200 nm thick SiO2 on silicon have been irradiated with increasing fluences of He ions. The projected range of He was chosen to be 650 nm in order to avoid residual He in the VO2 nanoclusters and the surrounding SiO2. The VO2 nanoclusters have been synthesized by sequential ion implantation of the elements vanadium and oxygen followed by a rapid thermal annealing step. Irradiation with He ions leads to the generation of reversible lattice point defects in the nanocrystalline VO2 precipitates. Simultaneously there is no electronic doping by He incorporation. The effect of the local- and long-range structural disorder on the metal-to-insulator phase transition has been investigated as a function of He fluence by μ-Raman spectroscopy and temperature dependent spectral ellipsometry. The disappearance of a low-frequency Raman mode indicates increasing disorder in the long-range crystal structure due to He irradiation. At the same time the thermal hysteresis of the metal-to-insulator transition narrows.