bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma Cleaning of a Commercially Available Hydroxyapatite-Coated External Fixation Pin by the Radio Frequency Glow Discharge Technique
Authors: Kumar S , Skinner WM 
Published: December 2005

Abstract
The surface chemistry of a commercially available hydroxyapatite (HA)-coated external fixation pin in its as-received state has been studied using X-ray photoelectron spectroscopy (XPS). The XPS investigations revealed that the HA coating on the pin was contaminated with silicon (organosilicone) and it exhibited sub-stoichiometric chemical composition (i.e., Ca/P∼0.9). A comparison of the high resolution XPS spectra of both the HA-coated pin and the inside of its protective elastomer cap revealed that silicon to be in the form of an organosilane transferred from the protective cap to the HA surface, thus contaminating the latter. A parallel plate radio frequency glow discharge plasma cleaning system was successfully employed for removing the surface contaminant (organosilicone) from the HA-coated pin. As confirmed by XPS, plasma cleaning for 15 min was sufficient for achieving complete removal of the silicon contaminant and exposing a clean HA layer with a stoichiometric Ca/P ratio of 1.7.
Analytical Methods and Acceptance Criteria for Cleaning Validation Protocols for Medical Devices
Authors: LeBlanc DA 
Published: December 2005

Abstract
This paper presents alternative methods to utilize in measuring the effectiveness of cleaning processes and to measure effects of changes in a cleaning process for the manufacture of medical device implants. Recommended methods for setting cleaning validation acceptance criteria for various residues are presented, along with analytical methodologies to measure those residues. The advantages of the proposed analytical methods include their applicability to devices other than metallic implants and the fact that they are established analytical technologies.
Survey of Orthopedic Implant Cleanliness Test Methods
Authors: Treece BL 
Published: December 2005

Abstract
In the past, orthopedic implant cleanliness assessment has largely relied on visual and microbiological evaluations; this may not be the case in the future. Test methods to quantity and identify manufacturing residues may need to be added to the cleanliness toolbox to verify that contact materials have been removed to acceptable levels. ASTM has begun exploring this new territory with the F04.15.17. Cleanliness Testing Committee. This paper addresses the need for test methods by reporting a few techniques that may be successful in assessing the cleanliness of metallic implants. The survey describes an extraction technique and several methods that quantify categories of typical contact materials, such as machining oils, coolants and detergents. The methods range from simple gravimetric measurements to employing analytical instrumentation, including Total Organic Analyzers, Inductively Coupled Plasma Spectrometers and Fourier Transform Infrared Spectrometers. The approach of classifying residues as particular categories of contact materials facilitates the application of the techniques across many products and manufacturing processes and allows for a greater degree of standardization, as opposed to identifying specific components of an individual material. The methods described may prompt discussions and provide guidance for future ASTM efforts to develop new standards for orthopedic implants.
An International Evaluation of the Neutron Cross Section Standards
Authors: Carlson AD , Badikov SA , Chen Z , Gai EV , Hale GM , Hambsch F-J , Hofmann HM , Kawano T , Larson NM , Oh S-Y , Pronyaev VG , Smith DL , Tagesen S , Vonach H 
Published: December 2005

Abstract
Work is reported here on the process and present results of an international evaluation of the neutron cross section standards. The evaluations include the H(n,n), 3He(n,p), 6Li(n,t), 10B(n,α), 10B(n,α1γ), 197Au(n,γ), 235U(n,f), and 238U(n,f) standard reactions as well as the 238U(n,γ) and 239Pu(n,f) reactions. This evaluation was performed to include new experiments on the standards that have been made since the ENDF/B-VI evaluation was completed and to improve the evaluation process. Evaluations have been completed for the 6Li(n,t), 197Au(n,γ) and 238U(n,γ) cross sections. Also below 20 MeV the H(n,n), 235U(n,f), 238U(n,f) and 239Pu(n,f) cross sections are completed. Many of the cross sections being evaluated are used in neutron dosimetry for fluence determination. The general trend observed for the evaluations is an increase in the cross sections for most of the reactions from fractions of a percent to several percent compared with the ENDF/B-VI results.
Extensive Revision of the Kernel-based PREVIEW Program and Its Input Data
Authors: Serén T , Wasastjerna F 
Published: December 2005

AbstractThe kernel-based PREVIEW program, which calculates fluences, fluence rates, reaction and damage rates, etc. at a few important out-of-core locations in the Loviisa VVER-440 reactors has been extensively revised. New location-specific dosimetry cross sections based on the newly released IRDF-2002 library have been developed. A few cross-section condensation codes are tried and compared. Generally the results are in good agreement. Small differences may be attributable to the use of single precision and to different representations of the weighting spectrum. Also, some codes use the basic ENDF-format data directly while others use processed data with reduced precision.
Spent Fuel Monitoring with Silicon Carbide Semiconductor Neutron/Gamma Detectors
Authors: Natsume T , Doi H , Ruddy FH , Seidel JG , Dulloo AR 
Published: December 2005

Abstract
Silicon carbide semiconductor radiation detectors have been demonstrated for neutron and gamma-ray monitoring of spent nuclear fuel. Neutrons and gamma rays were monitored simultaneously over a 2050-h period, resulting in a gamma dose of over 6000 Gy to the SiC detector. No changes in the neutron and gamma-ray sensitivity were observed as a result of the gamma-ray exposure. After the spent-fuel measurements, the absolute neutron sensitivity was determined in a standard neutron field, and the degree of gamma-ray and neutron spectrum overlap were determined through exposures in intense gamma ray fields. No overlap was observed for gamma-ray dose rates up to 100 G/h.
Verification of MultiTrans Calculations by the VENUS-3 Benchmark Experiment
Authors: Kotiluoto P 
Published: December 2005

Abstract
The MultiTrans software has been developed at VTT Technical Research Centre of Finland for 3D radiation transport problems. Adaptive tree multigrid technique is used as a deterministic solution method. This enables local refinement of the calculation grid combined with the use of effective multigrid acceleration on tree-structured nested grids: starting from a fast solution on coarse grid, successive solutions are obtained on finer and finer grids. In the MultiTrans code, simplified spherical harmonics (SP3) radiation transport approximation is used. In order to test the applicability of the new MultiTrans code to reactor dosimetry problems, light water reactor pressure vessel steel (LWR-PVS) benchmark experiment VENUS-3 (with partial length shielded assemblies) was chosen. The results show good agreement to the experimental reaction rates of the VENUS-3 benchmark, demonstrating the applicability of the new MultiTrans code in reactor dosimetry.
Neutron and Photon Dosimetry at the LR-0 Reactor Using Paired Detectors
Authors: Fernandes AC , Novák E , Cardoso J , Santos L , Marques JG , Rýpar V 
Published: December 2005

Abstract
Paired thermoluminescence dosimeters and ionization chambers were used for characterizing mixed (neutron and photon) radiation fields at the LR-0, a zero power model of VVER reactors. Detector responses were investigated in standard photon and thermal neutron fields. A good agreement was obtained among the doses measured with the two methods. Furthermore, the measured photon and neutron attenuation values are consistent with those from evaluated, independent data.
Determination of Adjusted Neutron Spectra in Different MUSE Configurations by Unfolding Techniques
Authors: Plaschy M , Destouches C , Chawla R , Beretz D , Mellier F , Servière H , Fougeras P , Chaussonnet P , Domergue C , Laurens J-M , Philibert H 
Published: December 2005

Abstract
Investigations of spectrum adjustment by unfolding techniques for different locations of critical and driven subscritical MUSE4 configurations are presented. The current analysis is based on the recent accomplishment of specific foil activation measurements and on the use of the unfolding code STAY'SL in conjunction with IRDF-90 and IRDF-2002 dosimetry libraries. Specific developments have been conducted to consider the uncertainties associated with the determination of the experimental absolute reaction rates and the initial calculated spectrum in the most realistic manner. In this context, the iterative adjustment process for the neutron spectrum is established on the basis of variance/covariance matrices defined for the three types of input parameters, i.e., the experimental reaction rates, the initial spectrum, and the dosimetry nuclear data files. The results highlight the spectral variations between different locations of the MUSE4 cores, in particular the characteristic behavior of a subcritical configuration driven by an external T(d,n)He4 (14 MeV neutrons) source.
Experimental and Calculation Investigations of the Space-Energy Neutron and Photon Distribution in the Vicinity of Reactor Pressure Vessel and Surveillance Specimen Box of New Type in the WWER-1000 Mock-Up
Authors: Ošmera B , Mařík M , Cvachovec F , Tsofin V , Lomakin S , Zaritsky S , Egorov A , Brodkin E 
Published: December 2005

Abstract
The radiation field parameters in the vicinity of new type of WWER-1000 surveillance specimens boxes and in RPV simulator have been investigated in the WWER-1000 Mock-up in the reactor LR-0. The neutron and photon spectra have been measured with stilbene cylindrical crystals in the energy range approximately from 0.5 MeV to 10 MeV. The experimental values of integral neutron field parameters (attenuations of integral neutron flux densities between different points of mock-up as well as the spectral indices, i.e., ratios of integral neutron flux densities with different thresholds) were obtained also. The mock-up (LR-0 reactor) power monitoring during measurements was carried out with two fission chambers, one fixed, one moveable axially, so that four orders in power were covered. The experimental data (spectra, attenuation factors, and spectral indices) have been compared with the calculation results. The sensitivity to parameters of calculation model and method was evaluated also.
Validation of the Neutron Fluence Calculation on the VVER-440 RPV Support Structure
Authors: Belousov SI , Ilieva KD , Kirilova DL , Petrov BY , Polke E 
Published: December 2005

Abstract
Measurements with activation detectors were carried out on Unit 4 of Kozloduy NPP in order to validate the fluence calculation data for the RPV support structure. Irradiation of iron, copper, and niobium detectors was performed during the 17th fuel cycle. The neutron fluence on the support structure and the activities of irradiated detectors were calculated by the three-dimensional transport code TORT with BGL440 multigroup cross section library. The history of local power distribution in the reactor core was taken into account. The measured and calculated induced activities are in good agreement in the area of the support structure. The calculated fluence evaluation in this area is conservative.
Radio Frequency Plasma Treatment of PEEK Spinal Implants
Authors: Disegi JA , Roybal MA 
Published: December 2005

Abstract
Recent material developments have enabled metallic vertebral spacers to be redesigned from a biocompatible radiolucent polymer to allow clear X-Ray or MR assessment of bony fusion. Improved visualization response is considered a major clinical advantage during the post-operative recovery period. The use of implant quality polyetheretherketone (PEEK) polymer for the fabrication of radiolucent vertebral spacers poses a new set of material challenges. Traditional manufacturing methods associated with metallic implants are generally not satisfactory for polymeric materials. Polymers are relatively soft when compared to implant alloys and this can create manufacturing problems related to machining, deburring, and cleaning operations. The present study was performed to evaluate the use of radio frequency (RF) plasma treatment as a final surface modification for PEEK spinal implants. A brief description of the radio frequency plasma process is presented in addition to a discussion of the interaction between the gas plasma and substrate. Surface evaluation included goniometry testing to determine water contact angle before and after plasma treatment. X-ray photon spectroscopy analysis was used to characterize the elemental peaks, bond energies, and to define the semi-quantitative composition of the treated implant specimens. The relative advantages of plasma treatment are summarized.
Random Genetic Drift and Gamete Frequency
Authors: Mano Shuhei 
Published: December 2005

Abstract
An analytic expression of conditional expectation of transient gamete frequency, given that one of the two loci remains polymorphic, is obtained in terms of the diffusion process by calculating the moments of the distribution. Using this expression, a model where linkage disequilibrium is introduced by a single mutation is considered. The conditional expectation of the gamete frequency given that the locus with the mutant allele remains polymorphic is presented. The behavior is significantly different from the monotonic decrease observed in the deterministic model without random genetic drift.
Infant Orthopedics and Facial Appearance: A Randomized Clinical Trial (Dutchcleft)
Authors: Prahl Charlotte , Prahl-Andersen Birte , van't Hof Martin A. , Kuijpers-Jagtman Anne M. 
Published: December 2005

Objective: To study the effect of infant orthopedics on facial appearance. Design: Prospective two-arm randomized controlled trial in parallel with three participating academic cleft palate centers. Treatment allocation was concealed and performed by means of a computerized balanced allocation method. Setting: Cleft Palate Centers of Amsterdam, Nijmegen, and Rotterdam, the Netherlands. Patients: Infants with complete unilateral cleft lip and palate, no other malformations. Interventions: One group (IO+) wore passive maxillary plates during the first year, the other group (IO−) did not. Main Outcome Measure(s): Two metrical response modalities were used (i.e., visual analog scales and reference scores) to score facial appearance. Full face and cropped photographs were compared with reference photographs and were judged. The photographs were judged by 45 judges, 24 laypeople, and 21 professionals. Transformation of the scores into z scores was applied to compare and to pool both response modalities. The validity of each individual judge was evaluated, as was the reliability of the scales. Differences between the treatment groups were evaluated by means of t tests. Results: Photographs were available of 41 subjects, 21 with and 20 without infant orthopedics. No significant differences were found between groups. Mean z-score values for the full-face photographs were: group IO+ = 0.10 (SD = 0.73) and group IO− = −0.03 (SD = 0.48); for the cropped photographs were: group IO+ = 0.12 (SD = 0.71) and group IO− = −0.06 (SD = 0.55). Conclusions: Infant orthopedics have no effect on facial appearance.
Multipotent Neural Stem Cells from the Adult Tegmentum with Dopaminergic Potential Develop Essential Properties of Functional Neurons
Authors: Hermann Andreas , Maisel Martina , Wegner Florian , Liebau Stefan , Kim Dong-Wook , Gerlach Manfred , Schwarz Johannes , Kim Kwang-Soo , Storch Alexander 
Published: December 2005

AbstractNeurogenesis in the adult brain occurs within the two principal neurogenic regions: the hippocampus and the subventricular zone of the lateral ventricles. The occurrence of adult neurogenesis in non-neurogenic regions, including the midbrain, remains controversial, but isolation of neural stem cells (NSCs) from several parts of the adult brain, including the substantia nigra, has been reported. Nevertheless, it is unclear whether adult NSCs do have the capacity to produce functional dopaminergic neurons, the cell type lost in Parkinson's disease. Here, we describe the isolation, expansion, and in vitro characterization of adult mouse tegmental NSCs (tNSCs) and their differentiation into functional nerve cells, including dopaminergic neurons. These tNSCs showed neurosphere formation and expressed high levels of early neuroectodermal markers, such as the proneural genes NeuroD1, Neurog2, and Olig2, the NSC markers Nestin and Musashi1, and the proliferation markers Ki67 and BrdU (5-bromo-2-deoxyuridine). The cells showed typical propidium iodide–fluorescence-activated cell sorting analysis of slowly dividing cells. In the presence of selected growth factors, tNSCs differentiated into astroglia, oligodendroglia, and neurons expressing markers for cholinergic, GABAergic, and glutamatergic cells. Electrophysiological analyses revealed functional properties of mature nerve cells, such as tetrodotoxin-sensitive sodium channels, action potentials, as well as currents induced by GABA (γ-aminobutyric acid), glutamate, and NMDA (N-methyl-d-aspartate). Clonal analysis demonstrated that individual NSCs retain the capacity to generate both glia and neurons. After a multistep differentiation protocol using co-culture conditions with PA6 stromal cells, a small number of cells acquired morphological and functional properties of dopaminergic neurons in culture. Here, we demonstrate the existence of adult tNSCs with functional neurogenic and dopaminergic potential, a prerequisite for future endogenous cell replacement strategies in Parkinson's disease.
Characterization and Multipotentiality of Human Fetal Femur–Derived Cells: Implications for Skeletal Tissue Regeneration
Authors: Mirmalek-Sani Sayed-Hadi , Tare Rahul S. , Morgan Suzanne M. , Roach Helmtrud I. , Wilson David I. , Hanley Neil A. , Oreffo Richard O.C. 
Published: December 2005

Abstract
To date, the plasticity, multipotentiality, and characteristics of progenitor cells from fetal skeletal tissue remain poorly defined. This study has examined cell populations from human fetal femurs in comparison with adult-derived mesenchymal cell populations. Real-time quantitative polymerase chain reaction demonstrated expression of mesenchymal progenitor cell markers by fetal-derived cells in comparison with unselected adult-derived and immunoselected STRO-1–enriched adult populations. Multipotentiality was examined using cells derived from femurs and single-cell clones, culture-expanded from explants, and maintained in basal medium prior to exposure to adipogenic, osteogenic, and chondrogenic conditions. Adipocyte formation was confirmed by Oil Red O lipid staining and aP2 immunocytochemistry, with expression of peroxisome proliferation-activated receptor-γ detected only in adipogenic conditions. In chondrogenic pellets, chondrocytes lodged within lacunae and embedded within dense proteoglycan matrix were observed using Alcian blue/Sirius red staining and type II collagen immunocytochemistry. Osteogenic differentiation was confirmed by alkaline phosphatase staining and type I collagen immunocytochemistry as well as by gene expression of osteopontin and osteocalcin. Single-cell clonal analysis was used to demonstrate multipotentiality of the fetal-derived populations with the formation of adipogenic, chondrogenic, and osteogenic populations. Mineralization and osteoid formation were observed after culture on biomimetic scaffolds with extensive matrix accumulation both in vitro and in vivo after subcutaneous implantation in severely compromised immunodeficient mice. These studies demonstrate the proliferative and multipotential properties of fetal femur–derived cells in comparison with adult-derived cells. Selective differentiation and immunophenotyping will determine the potential of these fetal cells as a unique alternative model and cell source in the restoration of damaged tissue.
Differential Expression of α2 Integrin Separates Long-Term and Short-Term Reconstituting Lin−/loThy1.1loc-kit+ Sca-1+ Hematopoietic Stem Cells
Authors: Wagers Amy J. , Weissman Irving L. 
Published: December 2005

Abstract
Self-renewing, multipotent hematopoietic stem cells are highly enriched within the Lin− Thy1.1loc-kit+ Sca-1+ subset of mouse bone marrow. However, heterogeneous expression within this population of certain cell surface markers raises the possibility that it may be further fractionated phenotypically and perhaps functionally. We previously identified α2-integrin (CD49b) as a surface marker with heterogeneous expression on Lin− /loThy1.1loc-kit+ Sca-1+ stem cells. To determine whether differences in α2 expression were indicative of differences in stem cell function, we purified α2− and α2hi stem cells by fluorescence-activated cell sorting and analyzed their function in long- and short-term hematopoietic reconstitution assays. Both α2− and α2hi cells could give rise to mature lymphoid and myeloid cells after transplantation into lethally irradiated congenic recipients. However, α2hi cells supported hematopoiesis for only a short time (&lt;4 weeks), whereas α2− cells reproducibly yielded robust, long-term (&gt;20 weeks) reconstitution, suggesting that α2− cells represent a more primitive population than do α2hi cells. Consistent with this idea, α2− Lin− /loThy1.1loc-kit+ Sca-1+ cells exhibited an approximately sixfold decreased frequency of spleen colony-forming units (day 12) versus α2hi cells. Furthermore, bone marrow cells isolated from animals transplanted &gt;20 weeks previously with 20 α2− Lin− /loThy1.1loc-kit+ Sca-1+ cells included both α2− and α2hi stem cells of donor origin, indicating that α2hi cells are likely lineal descendents of α2− cells. Interestingly, α2 integrin expression is significantly reduced on lineage-restricted oligopotent progenitors in the marrow, suggesting that high level expression of α2 selectively marks a subset of primitive hematopoietic cells which retains multilineage reconstitution potential but exhibits reduced self-renewal capacity.
Thymidine Analogs Are Transferred from Prelabeled Donor to Host Cells in the Central Nervous System After Transplantation: A Word of Caution
Authors: Burns Terry C. , Ortiz-González Xilma R. , Gutiérrez-Pérez María , Keene C. Dirk , Sharda Rohit , Demorest Zachary L. , Jiang Yuehua , Nelson-Holte Molly , Soriano Mario , Nakagawa Yasushi , Luquin María Rosario , Garcia-Verdugo Jose Manuel , Prósper Felipe , Low Walter C. , Verfaillie Catherine M. 
Published: December 2005

Abstract
Thymidine analogs, including bromodeoxyuridine, chlorodeoxyuridine, iododeoxyuridine, and tritiated thymidine, label dividing cells by incorporating into DNA during S phase of cell division and are widely employed to identify cells transplanted into the central nervous system. However, the potential for transfer of thymidine analogs from grafted cells to dividing host cells has not been thoroughly tested. We here demonstrate that graft-derived thymidine analogs can become incorporated into host neural precursors and glia. Large numbers of labeled neurons and glia were found 3–12 weeks after transplantation of thymidine analog-labeled live stem cells, suggesting differentiation of grafted cells. Remarkably, however, similar results were obtained after transplantation of dead cells or labeled fibroblasts. Our findings reveal for the first time that thymidine analog labeling may not be a reliable means of identifying transplanted cells, particularly in highly proliferative environments such as the developing, neurogenic, or injured brain.