bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deformation and recrystallization of pyrite
Authors: McClay K. R. , Ellis P. G. 
Published: December 2006

AbstractA detailed study of pyrite in a number of metamorphosed, stratiform, sediment-hosted Pb-Zn deposits has shown the importance of cataclastic deformation, pressure-solution, and grain growth in the deformation and textural development of pyrite. Primary depositional or early diagenetic microstructures are preserved in pyritic ores deformed or metamorphosed at grades up to mid-upper greenschist facies, whereas at higher temperatures only metablastic or annealed pyrite textures are found. Brittle deformation is found at all metamorphic grades and is favoured by coarse grain-sizes. Pressure-solution is a major deformation mechanism in fine-grained pyritic ores in low-grade metamorphic environments. Grain growth and annealing dominate at higher metamorphic temperatures and are likely to have obliterated any evidence of deformation by dislocation processes. Significant macroscopic ductility of fine-grained pyritic ores in low-grade environments may be accounted for by a combination of pressure-solution, grain boundary sliding, and cataclastic flow.
Silver mineralization at Sark's Hope mine, Sark, Channel Islands
Authors: Ixer R. A. , Stanley C. J. 
Published: December 2006

AbstractSark's Hope silver-lead lode, which was mined during the 1830s and 1840s cuts a Late Precambrian granite at the southernmost point of the island of Sark. The primary ore assemblage is pyrite, galena, chalcopyrite, tennantite, tetrahedrite, sphalerite, marcasite, arsenopyrite, pyrrhotine, bravoite, enargite, and the silver minerals pyrargyrite, pearceite, polybasite, and acanthite. Gangue minerals are hematitic quartz, calcite, and illite. Alteration products include chalcosine, covelline, blaubleibender covelline, limonite, malachite, azurite, cerussite, and anglesite. The generalized paragenesis is of early Fe, Co, Ni, As, and S species and later minerals of Pb, Cu, Ag, Zn, Fe, As, Sb, and S. The earliest alteration products are copper sulphides; these are followed by lead and copper carbonates and sulphates, and hydrated iron and manganese oxides. Growth zoning is a common feature of many of the ore minerals, and electron microprobe analysis shows that this is sometimes related to compositional differences. Tetrahedrite and tennantite, particularly, exhibit a wide range of compositions.
Sb-rich rutile in the manganese concentrations at St. Marcel-Praborna, Aosta Valley, Italy: petrology and crystal-chemistry
Authors: Smith David C. , Perseil Elena-Adriana 
Published: December 2006

AbstractThe petrographical, crystal-chemical and petrogenetical aspects of rutile rich in antimony (up to 33.75 wt.% Sb2O5; equal to 0.2 Sb5+ per O = 2) from St. Marcel-Praborna in the Aosta Valley, Italy, were re-examined. These compositions occur in two different petrographical environments (within the rock matrix or as microinclusions within Sb-rich titanite) in the manganese concentrations at this locality. The new data confirm our earlier hypothesis that two distinct petrogenetical/crystal-chemical processes both occurred: 1. Sb-metasomatism of pre-existing Sb-free rutile inclusions; and 2. creation of neoblastic Sb-rich rutile by the expulsion of Ti from pre-existing Sb-free titanite being metasomatized by Sb to form Sb-rich titanite. In the literature, Sb in minerals is variably considered as being trivalent and/or pentavalent. This work demonstrates that within rutile it is entirely Sb5+, substituting for Ti4+ by the following heterovalent cation exchange mechanism which is also the dominant one in the host Sb-rich titanite: 2 viR4+ = viR3+ + viR5+, where viR3+ = (Al,Cr,Mn,Fe)3+. A near-perfect correlation of ΣR5+vs. ΣR3+ (r > 0.98) is perturbed only by the presence of trace amounts of Ca2+, Sr2+ and Ba2+. Traces of Mn4+, Si4+ and/or (OH)− might also be present. These alkaline earth cations are the largest cations ever recorded in the rutile structure and are seemingly too large to occupy normal octahedral sites. The cation exchange mechanism involved might be that found in the ‘trirutile’ mineral group: 3 viR4+ = viR2+ + 2 viR5+. Alternatively these large divalent cations may be situated in the lozenge-shaped tunnels of the rutile structure, by analogy with other large cations occupying the wider subrectangular tunnels in the analogous cryptomelane/hollandite/priderite, romanéchite and todorokite mineral groups. This leads to a possible new cation exchange mechanism for the rutile structure: 2 viR4+ + tunelvacant = 2 viR3+ + tunnelR2+.
Crystal structure refinement of miargyrite, AgSbS2
Authors: Smith Joseph V. , Pluth Joseph J. , Han Shao-Xu 
Published: December 2006

AbstractMiargyrite is the low-temperature monoclinic derivative of a high temperature cubic galena/halite structure. The essential features of its crystal structure (Knowles, 1959) were confirmed, but the details of the bonding changed [new space group C121; a 12.824(1), b 4.4060(3), c 13.193(1) Å, β 98.567(6)°]. The octahedral connectivity of galena/halite is severely distorted: Ag(1), 2S each at 2.53, 2.66 & 3.39 Å; Ag(2), 2 each at 2.54, 2.62 and 3.44; Ag(3), 2.38, 2.40, 3.05, 3.05, 3.53, 3.58; Sb(1), 2.45, 2.50, 2.51, 3.22 3.28, 3.41; Sb(2), 2.45, 2.50, 2.51, 3.22, 3.28, 3.41. The short distances define the following coordinations: very distorted tetrahedral Ag(1) and (2); near-linear Ag(3) at 178.9(2)° trigonal-pyramidal Sb(1) and (2) at 92.0, 93.6 and 96.8°. The ten shortest S-S distances range from 3.61 to 3.77 Å.
Crystal structure of austinite, CaZn(AsO4)OH
Authors: Clark Lori A. , Pluth Joseph J. , Steele Ian , Smith Joseph V. , Sutton Stephen R. 
Published: December 2006

AbstractAustinite belongs to the adelite mineral group of calcium and lead arsenates, and has the conichalcite/descloizite type of crystal structure. The crystal structure of nearly pure austinite, CaZn(AsO4)OH, was redetermined (R = 0.014) and the absolute configuration identified. The space group P212121 and cell parameters a 7.5092(8), b 9.0438(9), c 5.9343(8) Å match previous data. Zinc octahedra share edges to form chains parallel to c. Arsenic tetrahedra share vertices with the Zn octahedra to generate a compact framework. Calcium square antiprisms share edges to make chains parallel to a that occupy the channels in the zinc-arsenic framework.
The crystal structure of mawbyite, PbFe2(AsO4)2(OH)2
Authors: Kharisun  , Taylor M. R. , Bevan D. J. M. , Rae A. D. , Pring A. 
Published: December 2006

AbstractThe crystal structure of mawbyite, PbFe2(AsO4)2(OH)2 has been refined. The mineral is monoclinic, C2/m with a = 9.066(4), b = 6.286(3) c = 7.564(3) Å, β = 114.857(5)°, Z = 2; the structure has been refined to a conventional R = 4.3% using 361 observed reflections [I> 3σ(I)]. The structure contains chains of edgesharing Fe(O,OH)6 octahedra which are linked by AsO4 tetrahedra and Pb atoms in distorted square antiprismatic co-ordination. The hydrogen bonding network in the structure has been modelled using bond valence calculations. Mawbyite is confirmed to be isostructural with tsumcorite and dimorphous with carminite and the relationship between these two structures is discussed.
Al-rich warwickite from lnglefield Land, North-West Greenland
Authors: Uitterdijk Appel Peter W. 
Published: December 2006

AbstractWarwickite constitutes about 5% of an outcrop of metamorphosed ultramafic rocks of Precambrian age in North-West Greenland. It occurs as slender grains, several millimetres long, and in anhedral grains up to 5 mm in size, together with forsterite, pleonaste, phlogopite, magnetite ± tourmaline. Post-metamorphic alteration of warwickite produced a network of boron-rich minerals and magnetite. The warwickite, containing up to 9.72% Al2O3, displays a significantly different chemical composition from warwickite elsewhere, such as that in recrystallized limestones from the type locality Warwick, New York, and in lamproitic and carbonatite-like rocks at Jumilla, Spain.
Igneous graphite in enstatite chondrites
Authors: Rubin Alan E. 
Published: December 2006

AbstractIgneous graphite, a rare constituent in terrestrial mafic and ultramafic rocks, occurs in three EH and one EL enstatite chondrite impact-melt breccias as 2–150 µm long euhedral laths, some with pyramidal terminations. In contrast, graphite in most enstatite chondrites exsolved from metallic Fe-Ni as polygonal, rounded or irregular aggregates. Literature data for five EH chondrites on C combusting at high temperatures show that Abee contains the most homogeneous C isotopes (i.e. δ13C = −8.1 ± 2.1‰); in addition, Abee's mean δ13C value is the same as the average high-temperature C value for the set of five EH chondrites. This suggests that Abee scavenged C from a plurality of sources on its parent body and homogenized the C during a large-scale melting event. Whereas igneous graphite in terrestrial rocks typically forms at relatively high pressure and only moderately low oxygen fugacity (e.g., ∼ 5 kbar, logfO2 ∼ −10 at 1200°C), igneous graphite in asteroidal meteorites formed at much lower pressures and oxygen fugacities.
Plasmacytoid DCs regulate recall responses by rapid induction of IL-10 in memory T cells
Authors: Kvale Espen O. , Fløisand Yngvar , Lund-Johansen Fridtjof , Rollag Halvor , Farkas Lorant , Ghanekar Smita , Brandtzaeg Per , Jahnsen Frode L. , Olweus Johanna 
Published: December 2006

AbstractDendritic cells (DCs) are believed to regulate T cell-mediated immunity primarily by directing differentiation of naive T cells. Here, we show that a large fraction of CD4+ memory cells produce IL-10 within the first hours after interaction with plasmacytoid DCs (PDCs). In contrast, CD11c+ DCs induce IFN-γ and little IL-10. IL-10–secreting T cells isolated after 36 hours of culture with PDCs suppressed antigen-induced T-cell proliferation by an IL-10–dependent mechanism, but were distinct from natural and type 1 regulatory T cells. They proliferated strongly and continued to secrete IL-10 during expansion with PDCs, and after restimulation with immature monocyte-derived DCs or CD11c+ DCs. The IL-10–producing T cells acquired the ability to secrete high levels of IFN-γ after isolation and subsequent coculture with PDCs or CD11c+ DCs. Compared to CD11c+ DCs, PDCs were superior in their ability to selectively expand T cells that produced cytokines on repeated antigenic challenge. The DC-dependent differences in cytokine profiles were observed with viral recall antigen or staphylococcal enterotoxin B and were independent of extracellular type I interferon or IL-10. Our results show that DCs can regulate memory responses and that PDCs rapidly induce regulatory cytokines in effector T cells that can suppress bystander activity.
HIV inhibits CD4+ T-cell proliferation by inducing indoleamine 2,3-dioxygenase in plasmacytoid dendritic cells
Authors: Boasso Adriano , Herbeuval Jean-Philippe , Hardy Andrew W. , Anderson Stephanie A. , Dolan Matthew J. , Fuchs Dietmar , Shearer Gene M. 
Published: December 2006

AbstractInfection with the human immunodeficiency virus type-1 (HIV) results in acute and progressive numeric loss of CD4+ T-helper cells and functional impairment of T-cell responses. The mechanistic basis of the functional impairment of the surviving cells is not clear. Indoleamine 2,3-dioxygenase (IDO) is an immunosuppressive enzyme that inhibits T-cell proliferation by catabolizing the essential amino acid tryptophan (Trp) into the kynurenine (kyn) pathway. Here, we show that IDO mRNA expression is elevated in peripheral blood mononuclear cells (PBMCs) from HIV+ patients compared with uninfected healthy controls (HCs), and that in vitro inhibition of IDO with the competitive blocker 1-methyl tryptophan (1-mT) results in increased CD4+ T-cell proliferative response in PBMCs from HIV-infected patients. We developed an in vitro model in which exposure of PBMCs from HCs to either infectious or noninfectious, R5- or X4-tropic HIV induced IDO in plasmacytoid dendritic cells (pDCs). HIV-induced IDO was not inhibited by blocking antibodies against interferon type I or type II, which, however, induced IDO in pDCs when added to PBMC cultures. Blockade of gp120/CD4 interactions with anti-CD4 Ab inhibited HIV-mediated IDO induction. Thus, induction of IDO in pDCs by HIV may contribute to the T-cell functional impairment observed in HIV/AIDS by a non–interferon-dependent mechanism.
Reduced-intensity conditioning for myeloma: lower nonrelapse mortality but higher relapse rates compared with myeloablative conditioning
Authors: Crawley Charles , Iacobelli Simona , Björkstrand Bo , Apperley Jane F. , Niederwieser Dietger , Gahrton Gösta ,   for the Chronic Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT)
Published: December 2006

Abstract
Despite the widespread adoption of reduced-intensity conditioning (RIC) for myeloma, there are few data comparing outcomes with RIC with myeloablative conditioning (MAC). We report the outcomes of patients undergoing allogeneic transplantations for myeloma and reported to the EBMT. A minimum data set was available on 320 RIC and 196 MAC allografts performed between 1998 and 2002. The RIC patients were older (51 vs 45 years) with more progressive disease (28% vs 21%) and more had received a prior transplant (76% vs 11%). In addition, there was a longer time to transplantation and an increased use of peripheral blood and T-cell depletion. For RIC and MAC, respectively, the nonrelapse mortality (NRM) at 2 years was 24% and 37% (P = .002); overall survival, 38.1% and 50.8% (not significant [ns]); and progression-free survival (PFS), 18.9% and 34.5% (P = .001). On multivariate analysis, RIC was associated with a reduction in NRM (HR, 0.5), but this was offset by an increase in relapse risk (HR, 2.0), and the conditioning intensity did not impact on overall survival or retain significance for PFS. These data suggest that there is a continuing need to investigate dose intensity in the conditioning for myeloma allografts.
Blockade of adaptive defensive changes in cholesterol uptake and synthesis in AML by the addition of pravastatin to idarubicin + high-dose Ara-C: a phase 1 study
Authors: Kornblau Steven M. , Banker Deborah E. , Stirewalt Derek , Shen Danny , Lemker Elizabeth , Verstovsek Srdan , Estrov Zeev , Faderl Stefan , Cortes Jorge , Beran Miloslav , Jackson C. Ellen , Chen Wenjing , Estey Elihu , Appelbaum Frederick R. 
Published: December 2006

Abstract
Following exposure to cytotoxic agents, acute myeloid leukemia (AML) blasts elevate cellular cholesterol in a defensive adaptation that increases chemoresistance, but blockade of HMG-CoA reductase with statins restores chemosensitivity in vitro. This phase 1 study evaluated adding pravastatin (PV) (40-1680 mg/day, days 1-8) to idarubicin (Ida) ([12 mg/(M2 · day), days 4-6]) + high-dose cytarabine (Ara-C; HDAC) [1.5 g/(M2 · day) by CI, days 4-7] in 15 newly diagnosed and 22 salvage patients with unfavorable (n = 26) or intermediate (n = 10) prognosis cytogenetics. Compared with historical experience with Ida-HDAC, the duration of neutropenia and throbmbocytopenia and the toxicity profile were unaffected by the addition of PV. During PV loading (day 0-4) serum triglyceride and total and LDL cholesterol levels decreased in nearly all patients. Pharmacokinetic studies demonstrated higher and more sustained serum PV levels with PV doses above 1280 mg/day. CR/CRp was obtained in 11 of 15 new patients, including 8 of 10 with unfavorable cytogenetics, and 9 of 22 salvage patients. An MTD for PV + Ida-HDAC was not reached. Addition of PV to Ida-HDAC was safe, and the encouraging response rates support conducting further trials evaluating the effect of cholesterol modulation on response in AML.
Deep and comparative analysis of the mycelium and appressorium transcriptomes of Magnaporthe grisea using MPSS, RL-SAGE, and oligoarray methods
Authors: Gowda Malali , Venu RC , Raghupathy Mohan B , Nobuta Kan , Li Huameng , Wing Rod , Stahlberg Eric , Couglan Sean , Haudenschild Christian D , Dean Ralph , Nahm Baek-Hie , Meyers Blake C , Wang Guo-Liang 
Published: December 2006

AbstractBackgroundRice blast, caused by the fungal pathogenMagnaporthe grisea, is a devastating disease causing tremendous yield loss in rice production. The public availability of the complete genome sequence ofM. griseaprovides ample opportunities to understand the molecular mechanism of its pathogenesis on rice plants at the transcriptome level. To identify all the expressed genes encoded in the fungal genome, we have analyzed the mycelium and appressorium transcriptomes using massively parallel signature sequencing (MPSS), robust-long serial analysis of gene expression (RL-SAGE) and oligoarray methods.ResultsThe MPSS analyses identified 12,531 and 12,927 distinct significant tags from mycelia and appressoria, respectively, while the RL-SAGE analysis identified 16,580 distinct significant tags from the mycelial library. When matching these 12,531 mycelial and 12,927 appressorial significant tags to the annotated CDS, 500 bp upstream and 500 bp downstream of CDS, 6,735 unique genes in mycelia and 7,686 unique genes in appressoria were identified. A total of 7,135 mycelium-specific and 7,531 appressorium-specific significant MPSS tags were identified, which correspond to 2,088 and 1,784 annotated genes, respectively, when matching to the same set of reference sequences. Nearly 85% of the significant MPSS tags from mycelia and appressoria and 65% of the significant tags from the RL-SAGE mycelium library matched to theM. griseagenome. MPSS and RL-SAGE methods supported the expression of more than 9,000 genes, representing over 80% of the predicted genes inM. grisea. About 40% of the MPSS tags and 55% of the RL-SAGE tags represent novel transcripts since they had no matches in the existingM. griseaEST collections. Over 19% of the annotated genes were found to produce both sense and antisense tags in the protein-coding region. The oligoarray analysis identified the expression of 3,793 mycelium-specific and 4,652 appressorium-specific genes. A total of 2,430 mycelial genes and 1,886 appressorial genes were identified by both MPSS and oligoarray.ConclusionThe comprehensive and deep transcriptome analysis by MPSS and RL-SAGE methods identified many novel sense and antisense transcripts in theM. griseagenome at two important growth stages. The differentially expressed transcripts that were identified, especially those specifically expressed in appressoria, represent a genomic resource useful for gaining a better understanding of the molecular basis ofM. griseapathogenicity. Further analysis of the novel antisense transcripts will provide new insights into the regulation and function of these genes in fungal growth, development and pathogenesis in the host plants.
Intracellular expression of toll-like receptor 4 in neuroblastoma cells and their unresponsiveness to lipopolysaccharide
Authors: Hassan Ferdaus , Islam Shamima , Tumurkhuu Gantsetseg , Naiki Yoshikazu , Koide Naoki , Mori Isamu , Yoshida Tomoaki , Yokochi Takashi 
Published: December 2006

Abstract

Background
Recently it has been reported that, toll-like receptors (TLRs) are expressed on a series of tumor cells, such as colon cancer, breast cancer, prostate cancer, melanoma and lung cancer. Although some cancer cells like melanoma cells are known to respond to lipopolysaccharide (LPS) via TLR4, not all cancer cells are positive for TLR4. There is little information on the expression and function of TLR4 in neuroblastoma cells. In this study, we investigated the expression of TLR4 in human neuroblastoma NB-1 cell line.

Methods
Expression and localization of TLR4 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometric analysis, respectively. Activation of nuclear factor (NF)-κB by LPS was detected by degradation of IκB-α and NF-κB luciferase assay. Activation and expression of mitogen-activated protein (MAP) kinase and interferon regulatory factor (IRF)-3 was detected by immunoblot analysis.

Results
Human NB-1 neuroblastoma cells expressed intracellular form of TLR4, but not the cell surface form. Further, NB-1 cells express CD14, MD2 and MyD88, which are required for LPS response. However, LPS did not significantly induce NF-κB activation in NB-1 cells although it slightly degraded IκB-α. NB-1 cells expressed no IRF-3, which plays a pivotal role on the MyD88-independent pathway of LPS signaling. Collectively, NB-1 cells are capable to avoid their response to LPS.

Conclusion
Although human NB-1 neuroblastoma cells possessed all the molecules required for LPS response, they did not respond to LPS. It might be responsible for intracellular expression of TLR4 or lack of IRF-3.
p150 ADAR1 isoform involved in maintenance of HeLa cell proliferation
Authors: Wang Haifang , Hou Zheng , Wu Yumei , Ma Xue , Luo Xiaoxing 
Published: December 2006

Abstract

Background
RNA-specific adenosine deaminase ADAR1 is ubiquitously expressed in a variety of mammalian cells and tissues. Although its physiological importance in non-nervous tissues has been confirmed by analysis of null mutation phenotypes, few endogenous editing substrates have been identified in numerous peripheral tissues and biological function of ADAR1 has not been fully understood.

Methods
A conditional site-specific, ribozyme-based gene knock-down strategy was utilized to study the function of full-length isoform of ADAR1 (p150 protein) in HeLa cell. Double-stable HeLa cell lines were developed by transfecting HeLa Tet-On cells with a pTRE-derived plasmid that can express a hammerhead ribozyme against mRNA of p150 ADAR1 isoform under induction condition. Semi-quantitative RT-PCR and Western blotting were performed to measure the expression of p150 in selected cell clones. Cell proliferation was evaluated by means of MTT assay and growth curve analysis. Cellular morphological changes were observed under light microscope. Flow Cytometry was used for cell cycle analysis. Growth rate of cell transplants in BALB/c nude mice was also investigated.

Results
Both HeLa cell proliferation in vitro and the growth rate of transplanted HeLa cell-derived tumors in nude mice in vivo were significantly inhibited due to reduced expression of ADAR1 p150. Additionally, cell cycle analysis showed that cell progression from G1 phase to S phase was retarded in the ADAR1 p150 suppressed cells.

Conclusion
Our results suggest that normal expression and functioning of p150 ADAR1 is essential for the maintenance of proper cell growth. The mechanisms underlying ADAR1's action might include both editing of currently unknown double-stranded RNAs and interacting with other cellular dsRNA-related processes.