bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase transitions in tridymite studied using ‘Rigid Unit Mode’ theory, Reverse Monte Carlo methods and molecular dynamics simulations
Authors: Dove M. T. , Pryde A. K. A. , Keen D. A. 
Published: July 2002

AbstractThe phase transitions in tridymite and the nature of the high-temperature phase are investigated using a combination of Rigid Unit Mode theory, neutron total scattering measurements analysed using the Reverse Monte Carlo method, and molecular dynamics simulations. The unusually large number of phase transitions in tridymite can be explained within the Rigid Unit Mode theory. The Rigid Unit Mode theory also gives an interpretation of the disordered high-temperature phase as revealed by the neutron scattering data and the molecular dynamics simulations. There is a close correspondence between the structure of the disordered high-temperature phase of tridymite and that of β-cristobalite.
Mineralogical aspects of cement in radioactive waste disposal
Authors: Glasser F. P. 
Published: July 2002

AbstractSome of the physical, chemical and mineralogical characteristics of Portland cement and related materials relevant to nuclear waste immobilization are defined. The ability to condition and maintain a high aqueous pH is undoubtedly the most important factor: it precipitates many species as hydrous oxides or hydroxides. However, in the longer term, many species – cationic as well as anionic – react with one or more cement components forming solubility-limiting phases. Progress on characterization of these phases is outlined. Many of the host phases have natural equivalents and this gives comfort in respect of their likely persistence over geological time. The emerging picture of immobilization in cement suggests that cement compositions can be tailored in terms of pH, Eh and internal chemistry so as to maximize immobilization potential. Nickel, uranium and chromium and chloride are used as examples.
Spontaneous strain in synthetic titanite, CaTiOSiO4
Authors: Malcherek T. 
Published: July 2002

AbstractLattice parameters of synthetic titanite powder, CaTiOSiO4, have been determined between room temperature and 1023 K. Only the e11 and e13 components contribute significantly to the strain tensor associated with the antiferroelectric-paraelectric phase transition at Tc = 487 K. A finite strain component e13 is observed in the paraelectric phase for 487 K < T < 825 K. The disappearance of this shear strain marks the isosymmetric transition near 825 K. The temperature evolution of the volume strain and of e11 is proportional to the squared order parameter observed in single-crystal diffraction experiments. The magnitude of the volume strain is sufficiently large to relate the observed near tricritical behaviour of the antiferroelectric-paraelectric phase transition to strain coupling.
Formation of the Denchai gem sapphires, northern Thailand: evidence from mineral chemistry and fluid/melt inclusion characteristics
Authors: Limtrakun P. , Zaw Khin , Ryan C. G. , Mernagh T. P. 
Published: July 2002

AbstractThe Denchai gem sapphire deposits in Phrae Province, northern Thailand are closely associated with late Cenozoic alkaline basaltic rocks. The sapphires occur in alluvial placer deposits in palaeo-channels at shallow depths. Electron microprobe analysis of minor and trace element contents (Fe, Ti, Cr, Ga and V) of the sapphires indicate the following oxide abundances: Fe2O3 (0.32–1.98 wt.%), TiO2 (0.01–0.23 wt.%), Cr2O3 (<0.01 wt.%), Ga2O3 (0.01–0.03 wt.%) and V2O5 (<0.03 wt.%). Optical studies of sapphires revealed three types of primary fluid/melt inclusions. CO2-rich inclusions (Type I) contain three phases (LH2O + LCO2 + V) with the vapour phase comprising <10–15 vol.%. The presence of CO2 was confirmed by microthermometry and laser Raman analysis. Polyphase inclusions (Type II) (vapour + liquid + solid) contain a fluid bubble (20–30 vol.%), an aqueous phase (10–15 vol.%) and several solid phases. Silicate-melt inclusions (Type III) comprise vapour bubbles, silicate glass and solid phases. Proton-induced X-ray emission (PIXE) analysis revealed high concentrations of K (~;4 wt.%) as well as Ca (~;0.5 wt.%), Ti (~;1 wt.%), Fe (~;2 wt.%), Mn (~;0.1 wt.%), V (<0.03 wt.%), Rb (~;70 ppm) and Zr (~;200 ppm) in the silicate glass. The Ga2O3 abundances and Cr2O3/Ga2O3 values (<1) of the sapphires favour their formation by magmatic processes. The presence of CO2-rich fluids and high K concentrations in the silicate melt inclusions link the origin of the Denchai gem sapphires to CO2-rich alkaline magmatism.
Neutron diffraction at simultaneous high temperatures and pressures, with measurement of temperature by neutron radiography
Authors: Le Godec Y. , Dove M. T. , Francis D. J. , Kohn S. C. , Marshall W. G. , Pawley A. R. , Price G. D. , Redfern S. A. T. , Rhodes N. , Ross N. L. , Schofield P. F. , Schooneveld E. , Syfosse G. , Tucker M. G. , Welch M. D. 
Published: July 2002

AbstractThe commissioning and operation of apparatus for neutron diffraction at simultaneous high temperatures and pressures is reported. The basic design is based on the Paris-Edinburgh cell using opposed anvils, with internal heating. Temperature is measured using neutron radiography. The apparatus has been shown in both on-line and off-line tests to operate to a pressure of 7 GPa and temperature of 1700°C. The apparatus has been used in a neutron diffraction study of the crystal structure of deuterated brucite, and results for 520°C and 5.15 GPa are presented. The diffraction data that can be obtained from the apparatus are of comparable quality to previous high-pressure studies at ambient temperatures, and are clearly good enough for Rietveld refinement analysis to give structural data of reasonable quality.
Raman microscopic study of the Li amphibole holmquistite, from the Martin Marietta Quarry, Bessemer City, NC, USA
Authors: Kloprogge J. T. , Case M. H. , Frost R. L. 
Published: July 2002

AbstractThe Raman spectrum of holmquistite, a Li-containing orthorhombic amphibole from Bessemer City, USA has been measured. The OH-stretching region is characterized by bands at 3661, 3646, 3634 and 3614 cm−1 assigned to 3 Mg–OH, 2 Mg + Fe2+–OH, Mg + 2Fe2+–OH and 3 Fe2+–OH, respectively. These Mg and Fe2+ cations are located at the M1 and M3 sites and have a Fe2+/(Fe2+ + Mg) ratio of 0.35. The 960–1110 cm−1 region represents the antisymmetric Si–O–Si and O–Si–O stretching vibrations. For holmquistite, strong bands are observed around 1022 and 1085 cm−1 with a shoulder at 1127 cm−1 and minor bands at 1045 and 1102 cm−1. In the region 650–800 cm−1 bands are observed at 679, 753 and 791 cm−1 with a minor band around 694 cm−1 attributed to the symmetrical Si–O–Si and Si–O vibrations. The region below 625 cm−1 is characterized by 14 vibrations related to the deformation modes of the silicate double chain and vibrations involving Mg, Fe, Al and Li in the various M sites. The 502 cm−1 band is a Li–O deformation mode while the 456, 551 and 565 cm−1 bands are Al–O deformation modes.
The exhumation history of orogenic belts from40Ar/39Ar ages of detrital micas
Authors: Stuart F. M. 
Published: July 2002

AbstractThe exhumation history of mountain belts can be derived from radiometric dating of detrital mineral grains in proximal and distal post- and synorogenic sediments. The application of single-crystal dating techniques avoids the averaging effect that characterizes multi-grain and whole-rock techniques and allows the identification of populations of grains with distinct thermal histories. Of the major single crystal dating methods available,40Ar/39Ar dating of detrital K-bearing minerals, in particular white mica, is perhaps the most versatile and widely applied technique. For a closure temperature of Ar of 350–400°C, muscovite40Ar/39Ar ages record the time a rock mass passed through 8–10 km beneath actively eroding mountain belts. Detrital muscovit ages eroded from orogenic mountain belts have been used extensively to identify the provenance of sediments from source regions with distinct thermal histories, determine the history and rate of exhumation of the source region, and provide an upper limit on the sediment age. Here I review the principles of40Ar/39Ar dating of detrital muscovite and illustrate the method with examples showing how the provenance and the thermal history of sediment source regions derived from such studies can be used to constrain the exhumation and tectonic history of orogenic belts.
Correction of geometric errors associated with the 3-D reconstruction of geological materials by precision serial lapping
Authors: Marschallinger R. 
Published: July 2002

AbstractPrecision serial lapping in combination with raster image acquisition is an efficient and versatile approach to 3-D microstructure reconstruction of geological materials. However, during associated sample preparation and data acquisition, geometric inaccuracies are introduced, which, if neglected, severely distort the desired 3-D models of minerals and rock fabrics. A novel method is presented to assess and correct the relative shifts and rotations between the images acquired at the individual erosion levels. The method relies on optical reflection prisms which provide a precise internal reference system that allows all images making up an erosion series to be registered on a common system of coordinates. Tested on a microanalyser with digital sample stage control, the method yielded position errors between successive images of approximately 1 µm. A thorough description of the mechanical design of the reference system and the coordinate transformation formulae are given.
Accumulation of HIF-1α under the influence of nitric oxide
Authors: Sandau Katrin Britta , Fandrey Joachim , Brüne Bernhard 
Published: July 2002

AbstractThe key player for adaptation to reduced oxygen availability is the transcription factor hypoxia-inducible factor 1 (HIF-1), composed of the redox-sensitive HIF-1α and the constitutively expressed HIF-1β subunits. Under normoxic conditions, HIF-1α is rapidly degraded, whereas hypoxia, CoCl2, or desferroxamine promote protein stabilization, thus evoking its transcriptional activity. Because HIF-1 is regulated by reactive oxygen species, investigation of the impact of reactive nitrogen species was intended. By using different nitric oxide (NO) donors, dose- and time-dependent HIF-1α accumulation in close correlation with the release of NO from chemically distinct NO donors was established. Intriguingly, small NO concentrations induced a faster but transient HIF-1α accumulation than higher doses of the same NO donor. In contrast, NO attenuated up-regulation of HIF-1α evoked by CoCl2 in a concentration- and time-dependent manner, whereas the desferroxamine-elicited HIF-1α signal remained unaltered. To demonstrate an autocrine or paracrine signaling function of NO, we overexpressed the inducible NO synthase and used a coculture system of activated macrophages and tubular cells. Expression of the NO synthase induced HIF-1α accumulation, which underscored the role of NO as an intracellular activator for HIF-1. In addition, macrophage-derived NO triggered HIF-1α up-regulation in LLC-PK1 target cells, which points to intercellular signaling properties of NO in achieving HIF-1 accumulation. Our results show that NO does not only modulate the HIF-1 response under hypoxic conditions, but it also functions as a HIF-1 inducer. We conclude that accumulation of HIF-1 occurs during hypoxia but also under inflammatory conditions that are characterized by sustained NO formation.
Human homologues of Delta-1 and Delta-4 function as mitogenic regulators of primitive human hematopoietic cells
Authors: Karanu Francis N. , Murdoch Barbara , Miyabayashi Tomoyuki , Ohno Mitsuhara , Koremoto Masahide , Gallacher Lisa , Wu Dongmei , Itoh Akira , Sakano Seiji , Bhatia Mickie 
Published: July 2002

AbstractDelta-mediated Notch signaling controls cell fate decisions during invertebrate and murine development. However, in the human, functional roles for Delta have yet to be described. This study reports the characterization of Delta-1 and Delta-4 in the human. Human Delta-4 was found to be expressed in a wide range of adult and fetal tissues, including sites of hematopoiesis. Subsets of immature hematopoietic cells, along with stromal and endothelial cells that support hematopoiesis, were shown to express Notch and both Delta-1 and Delta-4. Soluble forms of human Delta-1 (hDelta-1) and hDelta-4 proteins were able to augment the proliferation of primitive human hematopoietic progenitors in vitro. Intravenous transplantation of treated cultures into immune-deficient mice revealed that hDelta-1 is capable of expanding pluripotent human hematopoietic repopulating cells detected in vivo. This study provides the first evidence for a role of Delta ligands as a mitogenic regulator of primitive hematopoietic cells in the human.
Stat5a regulates T helper cell differentiation by several distinct mechanisms
Authors: Kagami Shin-ichiro , Nakajima Hiroshi , Suto Akira , Hirose Koichi , Suzuki Kotaro , Morita Sumiyo , Kato Ikunoshin , Saito Yasushi , Kitamura Toshio , Iwamoto Itsuo 
Published: July 2002

AbstractWe have previously shown that CD4+ T cell–mediated allergic inflammation is diminished in signal transducer and activator of transcription (Stat)5a-deficient (Stat5a−/−) mice. To determine whether Stat5a regulates T helper cell differentiation, we studied T helper (Th)1 and Th2 cell differentiation of Stat5a−/−CD4+ T cells at single-cell levels. First, Th2 cell differentiation from antigen-stimulated splenocytes was significantly decreased in Stat5a−/− mice as compared with that in wild-type mice. Further, Th2 cell differentiation was also impaired in Stat5a−/− mice even when purified CD4+ T cells were stimulated with anti-CD3 plus anti-CD28 antibodies in the presence of interleukin-4. Moreover, the retrovirus-mediated gene expression of Stat5a in Stat5a−/−CD4+ T cells restored the Th2 cell differentiation at the similar levels to that in wild-type CD4+ T cells. In addition, interleukin-4 normally phosphorylated Stat6 in CD4+ T cells from Stat5a−/− mice. Second, the development of CD4+CD25+ immunoregulatory T cells was impaired in Stat5a−/− mice, as indicated by a significant decrease in the number of CD4+CD25+ T cells in Stat5a−/− mice. Furthermore, the depletion of CD4+CD25+ T cells from wild-type splenocytes significantly decreased Th2 cell differentiation but increased Th1 cell differentiation, whereas the depletion of CD4+CD25+ T cells from Stat5a−/−splenocytes had no significant effect on the Th1 and Th2 cell differentiation. Together, these results indicate that the intrinsic expression of Stat5a in CD4+ T cells is required for Th2 cell differentiation and that Stat5a is involved in the development of CD4+CD25+ immunoregulatory T cells that modulate T helper cell differentiation toward Th2 cells.
High response rate in refractory and poor-risk multiple myeloma after allotransplantation using a nonmyeloablative conditioning regimen and donor lymphocyte infusions
Authors: Badros Ashraf , Barlogie Bart , Morris Christopher , Desikan Raman , Martin Sara R. , Munshi Nikhil , Zangari Maurizio , Mehta Jayesh , Toor Amir , Cottler-Fox Michele , Fassas Athanasios , Anaissie Elias , Schichman Steven , Tricot Guido 
Published: July 2002

Abstract
Standard allogeneic stem cell transplant (allo-SCT) regimens have been associated with a high transplant-related mortality (TRM) in multiple myeloma (MM). Nonmyeloablative therapy can establish stable engraftment after allo-SCT and maintain the antitumor effect with less toxicity, which is important in heavily pretreated and elderly patients. We report on 16 poor-risk MM patients receiving allo-SCT from an HLA-matched (n = 14) or mismatched (n = 2) sibling following conditioning with melphalan 100 mg/m2 (MEL-100). Ten patients had refractory relapse, 4 responsive relapse, and 2 patients were in near complete remission (nCR) with poor-prognosis disease. Patients had received 1 (n = 9) or 2 (n = 7) prior autotransplants. Donor lymphocyte infusions (DLIs) were given to 14 patients with no clinical evidence of graft versus host disease (GVHD) either to attain full donor chimerism (n = 4) or to eradicate residual disease (n = 10). Fifteen patients showed myeloid engraftment, and 12 patients were full donor chimeras at day +21. No TRM was observed during the first 100 days. Acute GVHD developed in 10 patients; 1 had fatal grade IV GVHD. Seven progressed to chronic GVHD, limited in 3 and extensive in 4 patients. At a median follow-up of 1 year, 5 patients achieved and sustained CR, 3 nCR, and 4 partial remission. Of 4 patients progressing after transplantation, 3 achieved a remission following further chemotherapy and DLI. Remarkable graft versus myeloma responses were seen in chemotherapy-refractory patients. Two patients died of progressive disease, and 3 died of GVHD complications without active disease. GVHD remains a major problem with this procedure.
Characteristics of early murine B-lymphocyte precursors and their direct sensitivity to negative regulators
Authors: Kouro Taku , Medina Kay L. , Oritani Kenji , Kincade Paul W. 
Published: July 2002

AbstractRecently, a collection of surface markers was exploited to isolate viable Lin− TdT+ cells from murine bone marrow. These early pro-B cells were enriched for B-lineage lymphocyte precursor activity measured by short-term culture and had little responsiveness to myeloid growth factors. Early precursors can be propagated with remarkably high cloning frequencies in stromal cell–free, serum-free cultures, permitting this analysis of direct regulatory factors. Expression of the interleukin-7 receptor (IL-7Rα) chain marks functional precursors and IL-7 is necessary for progression beyond the CD45RA+ CD19− stage. Efficient survival and differentiation were only observed when stem cell factor and Flt-3 ligand were also present. IL-7–responsive CD19+precursors are estrogen resistant. However, B-lineage differentiation was selectively abrogated when highly purified Lin− precursors were treated with hormone in the absence of stromal cells. In addition, early stages of B lymphopoiesis were arrested by limitin, a new interferon (IFN)–like cytokine as well as IFN-α, IFN-γ, or transforming growth factor β (TGF-β), but not by epidermal growth factor (EGF). Lin− TdT+early pro-B cells are shown here to be CD27+AA4.1+/−Ki-67+ Ly-6C−Ly-6A/Sca-1Lo/−Thy-1−CD43+CD4+/−CD16/32Lo/−CD44Hi and similar in some respects to the “common lymphoid progenitors” (CLP) identified by others. Although early pro-B cells have lost myeloid differentiation potential, transplantation experiments described here reveal that at least some can generate T lymphocytes. Of particular importance is the demonstration that a pivotal early stage of lymphopoiesis is directly sensitive to negative regulation by hormones and cytokines.
Thalidomide and immunomodulatory derivatives augment natural killer cell cytotoxicity in multiple myeloma
Authors: Davies Faith E. , Raje Noopur , Hideshima Teru , Lentzsch Suzanne , Young Gloria , Tai Yu-Tzu , Lin Boris , Podar Klaus , Gupta Deepak , Chauhan Dharminder , Treon Steven P. , Richardson Paul G. , Schlossman Robert L. , Morgan Gareth J. , Muller George W. , Stirling David I. , Anderson Kenneth C. 
Published: July 2002

AbstractThe antiangiogenic activity of thalidomide (Thal), coupled with an increase in bone marrow angiogenesis in multiple myeloma (MM), provided the rationale for the use of Thal in MM. Previously, the direct anti-MM activity of Thal and its analogues (immunomodulatory drugs, IMiDs) on MM cells was demonstrated, suggesting multiple mechanisms of action. In this study, the potential immunomodulatory effects of Thal/IMiDs in MM were examined. It was demonstrated that Thal/IMiDs do not induce T-cell proliferation alone but act as costimulators to trigger proliferation of anti-CD3–stimulated T cells from patients with MM, accompanied by an increase in interferon-γ and IL-2 secretion. However, an increase in autologous T-cell killing of patient MM cells could not be demonstrated. A role for natural killer (NK)- and LAK-cell–mediated killing is suggested because IL-2–primed peripheral blood mononuclear cells (PBMCs) treated with Thal/IMiDs demonstrated significantly increased lysis of MM cell lines. Cold target inhibition assays suggested NK- rather than LAK-cell–mediated killing. Furthermore, this killing was not major histocompatibility complex-class restricted, and the depletion of CD56+ cells blocked the drug-induced MM cell lysis. It was significant that increased killing of patient MM cells by autologous PBMCs treated with Thal/IMiDs was also observed. Although the in vivo relevance of NK-cell–mediated MM cell killing is unknown, phenotypic analysis performed in MM patients receiving Thal therapy demonstrated an increase in CD3−CD56+cells in patients responding to therapy. Thus in vitro and in vivo data support the hypothesis that Thal may mediate its anti-MM effect, at least in part, by modulating NK cell number and function.
Direct evidence that leukemic cells present HLA-associated immunogenic peptides derived from the BCR-ABL b3a2 fusion protein
Authors: Clark Richard E. , Dodi I. Anthony , Hill Seran C. , Lill Jennie R. , Aubert Geraldine , Macintyre Andrew R. , Rojas Jose , Bourdon Audrey , Bonner Philip L. R. , Wang Lihui , Christmas Stephen E. , Travers Paul J. , Creaser Colin S. , Rees Robert C. , Madrigal J. Alejandro 
Published: July 2002

Abstract
The BCR-ABL oncogene is central in the pathogenesis of chronic myeloid leukemia (CML). Here, tandem nanospray mass spectrometry was used to demonstrate cell surface HLA-associated expression of the BCR-ABL peptide KQSSKALQR on class I-negative CML cells transfected with HLA-A*0301, and on primary CML cells from HLA-A3–positive patients. These patients mounted a cytotoxic T-lymphocyte response to KQSSKALQR that also killed autologous CML cells, and tetramer staining demonstrated the presence of circulating KQSSKALQR-specific T cells. The findings are the first demonstration that CML cells express HLA-associated leukemia-specific immunogenic peptides and provide a sound basis for immunization studies against BCR-ABL.
Identifying intercellular signaling genes expressed in malignant plasma cells by using complementary DNA arrays
Authors: De Vos John , Couderc Guilhem , Tarte Karin , Jourdan Michel , Requirand Guilhem , Delteil Marie-Claude , Rossi Jean-François , Mechti Nadir , Klein Bernard 
Published: July 2002

AbstractIn multiple myeloma (MM), the growth of primary plasma cells depends not only on interleukin-6 (IL-6), but also on additional unidentified signals delivered by the bone marrow environment. Using Atlas complementary DNA (cDNA) arrays comprising 268 genes coding for intercellular signaling molecules, this study identified genes that are overexpressed in myeloma cells compared to autologous B-lymphoblastoid cell lines. These genes encode the oncogenic Tyro3 tyrosine kinase receptor, the heparin-binding epidermal growth factor–like growth factor (HB-EGF) that is an epithelial autocrine tumor growth factor, the thrombin receptor (TR) that is linked to HB-EGF and syndecan-1 processing and to cell invasion, chemokine receptors CCR1 and CCR2, the Wnt pathway actor Frizzled-related protein (FRZB), and the Notch receptor ligand Jagged 2. These data, obtained with the Atlas cDNA array, were confirmed by reverse transcriptase–polymerase chain reaction or protein analysis or both. Furthermore, Tyro3,HB-EGF, TR, and FRZB gene expression was documented in purified primary malignant plasma cells from patients with plasma cell leukemia or MM. HB-EGF and FRZB were poorly expressed in purified polyclonal plasma cells. Finally, HB-EGF was proved to be an essential autocrine growth factor for the XG-1 myeloma cells. This study shows the potency and the biologic relevance of cDNA arrays used to analyze simultaneously a large panel of intercellular signaling genes and, by identifying several genes overexpressed in malignant plasma cells, opens new fields of investigation in MM biology.