bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary Tumor Levels of Tissue Inhibitor of Metalloproteinases-1 Are Predictive of Resistance to Chemotherapy in Patients with Metastatic Breast Cancer
Authors: Schrohl Anne-Sofie , Meijer-van Gelder Marion E. , Holten-Andersen Mads N. , Christensen Ib Jarle , Look Maxime P. , Mouridsen Henning T. , Brünner Nils , Foekens John A. 
Published: November 2006

Abstract
Purpose: Only about 50% of metastatic breast cancer patients benefit from cytotoxic chemotherapy. Today, no validated markers exist for prediction of chemotherapy sensitivity/resistance in this patient group. Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been shown to protect against apoptosis, and the purpose of the present study was to test the hypothesis that tumors expressing high levels of TIMP-1 are protected against apoptosis-inducing agents and thus less sensitive to apoptosis-inducing chemotherapeutic drugs.
Experimental Design: We investigated the association between primary tumor expression levels of TIMP-1 protein and objective response to first-line chemotherapy in 173 patients with metastatic breast cancer.
Results: When analyzed as a continuous log-transformed variable, increasing TIMP-1 levels were significantly associated with lack of response to cyclophosphamide/methotrexate/5-fluorouracil and anthracycline-based chemotherapy (P = 0.01; odds ratio, 2.0; 95% confidence interval, 1.1-3.3). In a multivariate model, including lymph node status, steroid hormone receptor status, menopausal status, dominant metastases site, type of chemotherapy, and disease-free interval, TIMP-1 was significantly associated with resistance to treatment (P = 0.03; odds ratio, 1.7; 95% confidence interval, 1.1-3.3).
Conclusions: In the present exploratory study, we showed that elevated tumor tissue TIMP-1 levels were significantly associated with a poor response to chemotherapy. By using TIMP-1, we identified a group of patients with metastatic breast cancer, which hardly respond to the most frequently used chemotherapy regimes (i.e., cyclophosphamide/methotrexate/5-fluorouracil and anthracyclines).
Evidence by transmission electron microscopy of weathering microsystems in soils developed from crystalline rocks
Authors: Romero R. , Robert M. , Elsass F. , Garcia C. 
Published: November 2006

AbstractHigh-resolution electron microscopy and microanalytical studies were performed on clay and bulk soil samples developed on various igneous and metamorphic rocks from Galicia in the Coruna province in NW Spain. Two mineralogical microsystems can be distinguished showing different stages of weathering. For feldspars, exsolution and mass transformation lead to the delineation of parallel domains, and to formation of gel or paracrystalline minerals. For micas, alteration starts with a physical breakdown, i.e. exfoliation and crystal microdivision; individualization of monolayers is followed by gel formation. A solid phase diffusion phenomenon can explain the formation of 1 : 1 phyllosilicates inside 2 : 1 phyllosilicates or within the continuum of the original crystals. Evidence of such weathering stages in crystalline rocks can be related to the occurrence of specific climatic conditions between temperate and tropical areas.
X-ray diffraction measurement of the quartz content of clay and silt fractions in soils
Authors: Hardy M. 
Published: November 2006

AbstractAn XRD method for measurement of quartz content using ZnO as the internal standard was tested on different particle sizes between 0 and 20µm. Calibration curves showed a good correlation coefficient for particle-size fractions up to 20µm; the slope increased for the fractions from 0·7 to 5µm and was relatively constant for coarser particle sizes. Fine quartz fractions were etched with hydrofluoric acid to remove the surface layer damaged during dry grinding. The use of such etched quartz increased the slopes of the calibration curves for small particle-size fractions and approximated the natural fine quartz fraction much better than the original dry-ground material. The mean of six measurements gave good accuracy provided that the slope of the calibration curve was adjusted for the particular particle-size fraction. This method was used on 0–2µm, 0–0·2µm and 0·2–2µm fractions of French silty soils and the results are in agreement with the data from chemical analysis and with the mineralogical interpretation.
Characterization of FeOOH polymorphs and ferrihydrite using low-temperature, applied-field, Mössbauer spectroscopy
Authors: Pollard R. J. , Cardile C. M. , Lewis D. G. , Brown L. J. 
Published: November 2006

AbstractMössbauer spectroscopy obtained with the sample at low temperatures and subject to large magnetic fields is discussed in terms of its use in analysing the naturally occurring polymorphs of FeOOH and the common growth precursor, ferrihydrite. Experiments on well-characterized synthetic samples provided benchmark results. A relatively simple means of quantitative analysis was used, in which sextets of Voigtian-shaped lines were summed and least-squares fitted. The results are discussed in terms of the magnetic structures of each compound.
A comparison of methods for the extraction of smectites from calcareous rocks by acid dissolution techniques
Authors: Cook R. J. 
Published: November 2006

AbstractFour methods of extracting clays from calcite-rich samples were compared: (i) sodium acetate buffer solution; (ii) lithium acetate buffer solution; (iii) hydrochloric acid; (iv) liquid cation-exchange acid. The methods were tested on mixtures consisting of 80% calcite, 10% quartz and 10% hectorite. Potassium had previously been exchanged on to the interlayer sites of the clay. XRD traces of the extracted clays appeared identical with those of the original clays except for a sharpening of the 001 reflection. The bulk chemistry of the clay was unchanged except by the HCl extraction, which appeared to cause a stripping of the octahedral cations. With all of the methods the exchangeable cation content was altered; the sodium acetate method, for example, retained only 17% of the original exchangeable K+, the other methods all retaining <10%.
Exchange selectivity of lanthanide ions in montmorillonite
Authors: Maza-Rodriguez J. , Olivera-Pastor P. , Bruque S. , Jimenez-Lopez A. 
Published: November 2006

AbstractThe exchange of Ca2+ and Na+ by tanthanide ions (Ln3+ = Pr3+, Gd3+, Er3+) in montmorillonite was investigated at two different ionic strengths (0·01 and 0·1 mol/kg). Preferential sorption of Ln3+ was observed and variable selectivity coefficients were found depending upon the lanthanide concentration in the solid, and ionic strength. The highest exchange extent of Ln3+ always occurred for the system Na+/Ln3+, but the exchange selectivities of Ln3+ were generally higher in the exchange system Ca2+/Ln3+. Although the relative affinity of montmorillonite for the three lanthanide ions was similar, distinctive behaviour between Pr3+ and the heavier lanthanides, Gd3+ and Er3+, was noted. The study of Ln3+ adsorption in trace amounts showed specific adsorption of lanthanides at high concentrations of Na+ in the external solution and that the exchange stoichiometries in the interlayer regions were 3 : 1 at equilibrium pH = 4.
Clay adsorbed dyes: methylene blue on Laponite
Authors: Schoonheydt R. A. , Heughebaert L. 
Published: November 2006

AbstractThe adsorption of methylene blue (MB) from aqueous solution on Laponite (a synthetic 2:1 layer-silicate) exchanged with Na+, Cs+ and tetraethylammonium ions has been studied. At low loadings the monomer form predominates, but as the loading increases dimers and trimers (or higher aggregates) are formed, the latter being the most important species when the loading is equal to, or larger than, the Na+-CEC. The distribution of the molecules over the surface is time-dependent due to changes in the aggregation of the clay particles. On Cs+-Laponite, and to a lesser extent on Na+-Laponite, a small amount of MB is protonated by cation-coordinated water molecules. In similar work where adsorption was from ethanolic solution, MB is adsorbed as monomers and dimers only at small loadings and precipitates on the surface of the clay aggregates at high loadings. These precipitates can be broken up by sonication.
Stereoselectivity of montmorillonite in the adsorption and deamination of some amino acids
Authors: Siffert B. , Naidja A. 
Published: November 2006

AbstractOptical isomers deamination of L- and D-glutamic and aspartic amino acids and of their DL racemic mixtures has been achieved in the presence of Na-montmorillonite at pH = 6 and room temperature. The adsorption curves showed that the enantiomer adsorbed depends on the type of amino acid. Nevertheless, deamination reaction kinetics brought about a stereoselectivity of the clay mineral for the L-isomer and implicitly showed an unquestionable “structural chirality character” of the clay mineral.
Synthesis of zeolites from thermally activated kaolinite. Some observations on nucleation and growth
Authors: Murat M. , Amokrane A. , Bastide J. P. , Montanaro L. 
Published: November 2006

AbstractDepending on the preparation temperature and the origin of the raw mineral, the products obtained by thermal activation of kaolinite lead, by hydrothermal treatment with sodium hydroxide at 102°C, either to zeolite 4A, or to cubic zeolite P, or to a mixture of cubic and tetragonal zeolite P. The change in the type of zeolite obtained was explained on the basis of a radical change of the zeolite nucleation process due to either the presence of soluble potassium or high silica content resulting from dehydration of muscovite (an impurity in the raw-kaolinite), or from “segregation” associated with the first step of the metakaolinite to mullite transformation. These phenomena occur at a lower calcination temperature with poorly-crystallized kaolinite, and iron in such a sample promotes a sensitive decrease in the formation rate of zeolite crystals. Such results could be used to characterize the crystallinity of kaolinites.
Chemistry of illite-smectite inferred from TEM measurements of fundamental particles
Authors: Środoń J. , Elsass F. , McHardy W. J. , Morgan D. J. 
Published: November 2006

AbstractMixed-layer illite-smectites (I-S) have a stable charge on the illite interlayer equal to 0·89/O10(OH)2, as shown by electron microscope measurements of mean fundamental particle thickness, using both Pt-shadowing and high-resolution techniques. This has been verified by independent measurements of total surface area and CEC. Typically, the smectite interlayer charge is close to 0·4/O10(OH)2 but clays evolving in K-deficient environments may exhibit higher values. In the course of illitization, the silicate layer composition becomes more restricted than the smectite composition, AlIV and AlVI increasing while Fe and Mg decrease. These substitutions lead to the composition of non-expandable illite differing distinctly from that of muscovite and phengite, close to FIX0·89Al1·85Fe0·05Mg0·10Si3·20Al0·80. HRTEM data show that XRD systematically underestimates %S layers in I-S due to the small size of coherent scattering domains. An experimental curve is proposed for correcting XRD data. The above results were obtained for I-S formed from volcanic materials in different diagenetic and hydrothermal environments. The illite interlayer charge value close to 0·9 reconciles well the available data on I-S produced by wetting and drying of K-smectites.
Identification of vermiculite by transmission electron microscopy and X-ray diffraction
Authors: Vali H. , Hesse R. 
Published: November 2006

AbstractThe expandability of K-depleted biotite and natural vermiculite was studied using transmission electron microscopy (TEM) and X-ray diffraction (XRD). K-depletion in layer-silicates was achieved by treating ultrathin sections with 0·1 m CaCl2 and BaCl2 solutions. The natural sample of biotite, which by XRD revealed no expandability on ethylene glycol or glycerol solvation, displayed 10–15% expanded layers when viewed by TEM after alkylammonium intercalation. The proportion of expanded layers increased after CaCl2 treatment. XRD of vermiculite samples revealed two sets of expandable interlayers after alkylammonium treatment, corresponding to two types of particles with different layer structures observed by TEM. Identification of vermiculite by TEM based on basal spacings is reliable with alkylammonium treatment. Intercalation of alkylammonium ions into the interlayers of vermiculite improved the degree of stacking order of the 2:1 layers.
The Influence of analytical error upon the interpretation of chemical variations in clay minerals
Authors: Warren E. A. , Ransom B. 
Published: November 2006

AbstractUnderstanding the chemical variability of clay minerals depends on the analytical reliability of the techniques used. Uncertainties in clay mineral compositions were computed for common sources of analytical error such as those that arise from contaminant phases present in clay size-fractions in concentrations below the detection limit of routine XRD screening techniques, and the analytical limits of precision for TEM/AEM analysis. When plotted on standard diagrams used to represent clay mineral compositions, the calculated error envelopes were found to be of significant size, such that analyses of pure illites and pure smectites straddled the field for mixed-layered illite-smectites. In addition, on some diagrams random analytical errors resulted in linear trends identical to those caused by mixtures of two or more clay minerals. It follows that variations in the compositions of clay minerals reported in the literaure do not always necessarily represent the actual chemical variation of the minerals. As a result, current interpretations of clay compositional variations may not be as definitive as hoped.
Dating thermal anomalies in sedimentary basins: the diagenetic history of clay minerals in the Triassic sandstones of the Paris Basin, France
Authors: Mossmann J. R. , Clauer N. , Liewig N. 
Published: November 2006

AbstractRhaetian (Upper Triassic) sandy horizons were sampled from the Paris Basin from SW to NE, crosscutting the Rhaetian at different depths from outcrop in the NE to 2700 m in the centre of the basin. The smallest day sub-fractions (<0·2 μm) from the deepest samples consist mainly of illite and chlorite having a K-Ar age of 〜190 Ma. Both minerals probably formed under specific hydrothermal conditions at high temperature, but at a burial depth of only 500 m. This thermal event could represent an echo of the "crustal" breakdown of the Northwestern European craton during the opening of the North Atlantic Ocean. Two other generations of illite-smectite mixed-layers formed in the same Rhaetian horizons at somewhat lower temperatures about 150 and 80 Ma ago. The three generations of clay minerals could be characterized and dated because of combined mineralogical, crystallographical and morphological data supporting the dating attempts.
Ferripyrophyllite and related Fe3+-rich 2:1 clays in Recent deposits of Atlantis II Deep, Red Sea
Authors: Badaut D. , Decarreau A. , Besson G. 
Published: November 2006

AbstractIron-rich dioctahedral 2:1 clays were sampled in metalliferous sediments from Atlantis II Deep (Red Sea), and studied by XRD, TEM, FTIR and Mössbauer spectroscopy. One sample with the structural formula (Si3·94Fe3+0·06)(Fe3+1·90Mg0·10)K0·1(Mg, Ca)0·03 is closer to the theoretical end-member ferripyrophyllite Si4Fe3+2O10(OH)2 than any other Fe-rich clay previously described. Other samples appear as mixed-layered clays: ferripyrophyllite-hydroferripyrophyllite or hydroferripyrophyllite-celadonite.
Sudoite in some Visean (Lower Carboniferous) K-bentonites from Belgium
Authors: Anceau A. 
Published: November 2006

AbstractSudoite occurs as a cryptocrystalline clay in some Visean K-bentonites from Belgium. Usually associated with illite-smectite mixed-layers, this chlorite has been found locally as a monomineralic clay component of a K-bentonite bed. The mineral has a composition close to (Al3Mg2)(Si3Al)O10(OH)8. The cell parameters have been calculated from the diffractogram using the space group C2/m (a = 5·228, b = 9·056, c = 14·326 Å, β = 97°00′, d(060) = 1·509 Å). The polytype corresponds to a IIb structure. Some hypotheses are proposed for the origin of this chlorite. The coexistence of sudoite and pyrite could explain why the chlorite present in Visean K-bentonites is not a Fe-rich species typical of diagenetic conditions, but a Fe-poor one.
Chemical and mineralogical characteristics of Pleistocene caliche deposits from the Central Ebro Basin, NE Spain
Authors: Sancho C. , Melendez A. , Signes M. , Bastida J. 
Published: November 2006

AbstractChemical and mineralogical analyses of fossil caliche profiles developed on top of Lower Pleistocene alluvial formations in the East-central sector of the Ebro basin indicate that they have high content of carbonate (average 84%) and high Ca/Mg ratios (average 136). The clay mineral assemblages vary slightly depending on the host material, and, therefore, on the alluvial formation in the source area. Inherited detrital minerals (illite, kaolinite and chlorite), transformed components (from chlorite to mixed-layers of chlorite-vermiculite, and from smectite to palygorskite) and a neoformed phase (palygorskite) have been observed. The contents of carbonate and magnesian clay minerals (smectite and palygorskite) increase from the bottom to the top of the profiles, in relation to hardpan laminated caliche facies. The amount of palygorskite is controlled by the concentration of Mg2+ which in turn depends on the absolute content of Mg2+ in the host material and on its relative concentration by processes of evaporation linked to decreasing permeability in the profile during the biogenic-pedogenetic carbonate accumulation stages. These processes form part of the development of caliche profiles in a semi-arid environment.
Adsorption Behaviour of Cesium on Marl
Authors: Cornell R. M. 
Published: November 2006

AbstractAdsorption of Cs on two samples of marl with different calcite, quartz and clay contents and surface areas of ∼10 m2/g was followed using the batch sorption technique. The experiments were carried out in an atmosphere of N2/1% CO2 using a synthetic groundwater of pH 7·3 and an ionic strength of 0·1 m. The initial Cs concentration ranged from 10−8 to 10−4m. Sorption of Cs was non-linear, fast and reversible. At equilibrium Cs concentrations <10−8m, an isotope exchange mechanism appeared to operate, whereas at higher concentrations, sorption involved ion exchange. The distribution coefficients ranged from 23–995 ml/g. They varied markedly with rock/water ratio; this variation could be explained in terms of the non-linear isotherm displayed by Cs. Although the two samples of marl differed in composition, uptake of Cs on both samples was very similar because the content of the principal sorbing component (illite) was the same in both samples.
Local environment of lanthanum ions in montmorillonite upon heating
Authors: Trillo J. M. , Alba M. D. , Castro M. A. , Muñoz A. , Poyato J. , Tobías M. M. 
Published: November 2006

AbstractStructural differences which occur on heating La-montmorillonite have been studied and compared with those for montmorillonite saturated with Na(I) and Li(I). Rehydration experiments show that La-montmorillonite swells after preheating up to 500°C. However, FT-IR spectra suggest partial migration of the La(III) cations from the interlamellar region to the structural sheets and(or) deprotonation of hydrated La(III) cations, followed by migration of the resulting protons to vacant octahedral sites. Additional measurements of X-ray absorption spectra (EXAFS, XANES) and heating to 700°C suggest that interlamellar hydrated La(III) partially deprotonates producing polyoxocations.
Chemical and structural properties of clay minerals modified by inorganic and organic material
Authors: Bandosz T. J. , Jagiełło J. , Amankwah K. A. G. , Schwarz J. A. 
Published: November 2006

AbstractModification of clay minerals by exchange, intercalation, calcination and imbibition of organics followed by their polymerization and carbonization was studied. The surface properties of the clays were investigated by inverse gas chromatography at infinite dilution employing alkanes and alkenes as probes; the structural properties were measured directly by X-ray diffraction and inferred from the results of high pressure hydrogen adsorption. Calcination of pillared smectites prior to polymerization and carbonization of organic material in the interlayer space leads to a microporous “activated carbon” that demonstrates unique properties as an adsorbent for hydrogen, significantly different from clays that have not been calcined.
Organometallic cation-exchanged phyllosilicates: exchange with cations derived from (CH3)2SnCl2
Authors: Breen C. , Fleming J. P. E. , Molloy K. C. 
Published: November 2006

AbstractComplexes formed between 0·034 m dimethyltin dichloride solutions and Na-montmorillonite at pH 2·4 and 4·0 have been characterized using 119Sn Mössbauer spectroscopy, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis and water sorption isotherms. The dominant exchange cation at pH 2·4 is Me2Sn2+ characterized by an isomer shift, δ, and quadrupole splitting, Δ values of 1·25 and 3·80 mm s−1, respectively. The major exchange cation at pH 4·0 is the dimer, [Me2SnOH]22+, (δ = 1·38, Δ = 3·34 mm s−1) although the monomer, Me2Sn(OH)+, (δ = 0·95, Δ = 3·29 mm s−1) is also present. These complexes have basal spacings of 15·0 and 16·0 Å, respectively, which are stable up to 200°C. Mössbauer spectroscopy has shown that these ions are converted to SnO2 via Me2SnO upon thermal degradation. The temperature at which these oxides appear coincides with the collapse of the basal spacing. Both complexes display BET Type IV isotherms for the adsorption of water, following thermal pretreatment at 150°C, but the complex prepared at pH 4·0 has a lower sorption capacity. Both complexes, contrary to the normal behaviour of layer-silicates, have a definite pore volume and no further uptake occurs when this is filled.
Chlorite interstratified with a 7 Å mineral: an example from offshore Norway and possible implications for the interpretation of the composition of diagenetic chlorites
Authors: Hillier S. , Velde B. 
Published: November 2006

AbstractX-ray diffraction (XRD) patterns of a pore-lining diagenetic chlorite (14 Å) from a reservoir sandstone, offshore Norway, show broad odd-order and sharp even-order basal reflections indicating that it contains 7 Å layers. Using NEWMOD, simulated XRD patterns with 15% 7 Å serpentine layers and a maximum crystallite thickness of 30 layers match the natural mineral well. Microprobe analyses of the 7 Å-14 Å mineral indicate that it is Fe-rich and aluminous suggesting that it is interstratified berthierine-chamosite. Apparent octahedral vacancies, however, suggest a significant dioctahedral component, and an alternative interpretation is interstratified kaolinite-chlorite. Indeed, chemical analyses of the mineral suggest a mixture of chlorite with 15% kaolinite, precisely the proportion of 7 Å layers indicated by XRD. Two other examples from the literature, previously identified as diagenetic chlorite, are probably also 7 Å-14 Å interstratified minerals, and the proportion of 7 Å layers indicated by XRD is also correlated with their structural formulae, if the 7 Å layers are, in fact, kaolinitic. This type of interstratification could explain why Fe-rich diagenetic chlorites appear to be compositionally distinct from metamorphic chlorites. The structure and chemistry of the Norwegian chlorite tend to support the idea that pore-lining chlorites form early in the diagenetic history, inhibiting the precipitation of later diagenetic minerals, and hence preserving abnormally high porosity at greater depths.