bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methylprednisolone-Induced Toxic Hepatitis
Authors: Topal Firdevs , Özaslan Ersan , Akbulut Sabiye , Küçükazman Metin , Yüksel Osman , Altiparmak Emin 
Published: August 2006

Objective: To report the third published case, as of April 8, 2006, of methylprednisolone-induced toxic hepatitis. Case Summary: A 47-year-old woman was admitted to our clinic with weakness, fatigue, pruritus, and scleral icterus that had developed 10 days prior to presentation. She had been taking topiramate for one year for treatment of chronic isolated central nervous system vasculitis. One week before her symptoms developed, she had completed a self-prescribed 7 day course of oral methylprednisolone for treatment of left arm weakness. She believed that methylprednisolone was appropriate since it had been used previously for acute episodes of vasculitis. Results of liver function tests performed on admission were alanine aminotransferase 2478 U/L, aspartate aminotransferase 1600 U/L, total bilirubin 10 mg/dL, direct bilirubin 8 mg/dL, alkaline phosphatase 138 U/L, and γ-glutamyl transferase 242 U/L. Topiramate and methylprednisolone were the only drugs she had been taking before admission, and no other causes of liver dysfunction (eg, infection, ischemia, systemic disease) were identified. Topiramate was stopped, and enzyme levels decreased to normal values within 45 days without treatment. There had been no increase in enzyme levels during hospitalization upon the accidental use of topiramate. Based on the history and laboratory findings, the final diagnosis was mixed hepatocellular and cholestatic liver injury caused by methylprednisolone. Discussion: Steroids have rarely been associated with hepatotoxicity; moreover, they are the treatment of choice for severe hepatitis. To date, only 2 cases of methylprednisolone-induced hepatotoxicity have previously been reported. Our case is similar to those with regard to mixed hepatocellular and cholestatic liver injury. Resolution of the hepatotoxicity occurred after discontinuation of the drug, with conservative treatment measures. An objective causality assessment based on the Naranjo scale suggests that hepatotoxicity was probably related to methylprednisolone. Conclusions: Although rare, hepatotoxicity related to methylprednisolone should be considered in patients who develop elevated enzyme levels while receiving this steroid.
Some Observations on Montmorillonite-Organic Complexes
Authors: Byrne P. J. S 
Published: August 2006

AbstractFifteen pure montmorillonites selected on the basis of minor differences in x-ray diffraction and differential thermal analysis data were treated with ethylene glycol, piperidine, and dodecylamine. X-ray and differential thermal data of the resulting complexes lead to the following conclusions:(1) The complexes of montmorillonites with a given organic compound show differences ascribable to differences in the character of the montmorillonites. Attempts to relate variations in organic complexes to exchangeable cations, chemical composition, and collodial properties of the montmorillonites met with very limited success.(2) All montmorillonites are mixed-layer sequences; i.e. adjacent layers differ from one another in composition, structure, or some other factor. It is suggested that mixed layering of this nature may also occur in other three-layer clay minerals.
Stability and Swell Pressure Characteristics of Compacted Clays
Authors: Seed H. B. 
Published: August 2006

AbstractThis paper discusses some of the factors affecting the density vs. stability relationships of compacted clays and some of the limitations of the concept that the stability of a compacted soil increases with an increase in density.A series of tests performed on silty clay, in which stability was measured by triaxial compression tests, are described. It is shown that the relationship between density and stability of a soil depends on the criterion used to define stability; the greater the permissible strain before a sample is considered unstable, the greater is the possibility that an increase in density will cause an increase in stability. For the silty clay, when the stability is defined as the load required to cause 10 percent strain or less, an increase in density at a given water content caused an increase or decrease in stability depending upon the water content and the range of densities involved; at constant degrees of saturation, however, an increase in density always caused an increase in stability.The effect of compaction method on the density vs. stability relationship is illustrated. Test data are presented for two soils, a silty clay and a sandy clay, comparing the stabilities, at various water contents and densities, of partially saturated samples compacted by impact methods, static pressure and kneading action. It is shown that, at equal water contents and densities, samples compacted by static pressures exhibit higher stabilities than samples compacted by impact or kneading methods; also, that the stabilities of samples at equal densities and water contents, compacted by impact and kneading methods, are very similar, with kneading compaction producing somewhat higher stabilities at lower degrees of saturation, and impact compaction producing slightly higher stabilities at higher degrees of saturation. For static compaction, both soils showed an increase of stability with increase in density at all water contents, while for samples compacted by impact and kneading methods, an increase in density at a given water content did not necessarily lead to an increase in stability.The effect of saturation on the stability of compacted clays is shown and the influence of water content at compaction on the stability of saturated samples having the same density and water content is illustrated.Finally, a comparison is made of the stability and swell pressures developed at various densities of samples of the sandy clay compacted by kneading action and static pressure and subsequently saturated by exudation of moisture from the samples under static loads. It is shown that very much higher swell pressures and stabilities are exhibited by the statically compacted samples than by the samples prepared by kneading action.
Shapes of Halloysite Particles in Japanese Clays
Authors: Sudo Toshio , Takahashi Hiroshi 
Published: August 2006

AbstractHydrated halloysite clays altered from glassy tuff during weathering were examined in detail by x-ray, thermal, and electron micrographic methods. The electron micrographs show fibrous crystals of hydrated halloysite associated with many rounded grains, the former frequently jutting out from the latter. X-ray powder diffraction data and thermal curves show clearly the presence of hydrated halloysite, and on closer examination dehydrated halloysite and a small amount of montmorillonite can be detected. The presence of allophane as an accessory mineral is suggested in certain specimens. Furthermore the degree of crystallinity of hydrated halloysite varies slightly from specimen to specimen. The variation of the degree of crystallinity of the hydrated halloysite and of the kinds and amounts of accessory clay minerals, and the variation of the shapes of the particles observed in the electron micrographs are generally related to each other. Hydrated halloysite of a relatively well-crystallized sort generally co-exists with halloysite (dehydrated) and consists of elongated crystals having sharp edges; rounded grains are composed entirely of these fibrous crystals. On the other hand, a poorly crystallized sort tends to be associated with allophane and to show extremely fine hairlike, twisted fibers; these are associated with well-defined rounded grains. A genetic process of clay-mineral formation from volcanic glass is considered.
Reactions of Molten Salts with Layer-Lattice Silicates
Authors: White Joe L. 
Published: August 2006

AbstractA preliminary x-ray diffraction study of the effect of treatment of typical layer-lattice silicates with molten lithium, sodium, and potassium nitrates has been made. Treatment of Wyoming bentonite (Upton, Wyoming) with molten lithium nitrate produced random interstratification of spacings of 9.6 and 17.8 A when specimens were glycerol-solvated, with approximately 20 percent expanded layers. Treatment with sodium nitrate at 320° G produced a very high degree of preferred orientation in film specimens dried from water, whereas treatment with molten potassium nitrate produced a more random orientation in the specimen. The bentonite treated with molten sodium nitrate expanded completely to 17.8 A with glycerol; treatment with potassium nitrate resulted in a small amount of random interstratification, the proportion of expanded layers being about 80 percent.Treatment of the <5μ fraction of Delamica (muscovite) with molten lithium nitrate removed a large portion of the potassium from the mica, and lithium was fixed in a not readily exchangeable manner. When barium-saturated and glycerol-solvated, the treated material gave an 001 spacing of 17.8 A, the basal spacing for glycerol-montmorillonoids. The amount of potassium removed from the muscovite varied with the muscovite/lithium-nitrate ratio and length of treatment.
Summary of Clay-Mineral Studies in Germany, 1954 and 1955
Authors: Hofmann Ulrich 
Published: August 2006

AbstractCorrens and Lippmann have extended the work carried out in England on swelling chlorites by some investigations on Keuper clays.Dietzel has succeeded in showing that the infrared absorption band of kaolinite at 2.7 μ has two peaks which can be correlated with two different kinds of (OH) groups in the structure.The “fire-clay” type of clay mineral has been found in Grossalmeroder clay by Lippmann and in Frantex clay from Provins by von Engelhardt. In Frantex clay especially the layer sequence is highly disordered. Halloysite is distinguished from these minerals by its greater layer spacing and metahalloysite by its tubular morphology.Winkler has studied the particle size distribution of numerous brick clays and has established that the mineral must have a certain proportion of fine and coarse clay and fine sand, but also a very smooth particle size distribution curve from the finest to the coarsest particles if the clay is to be suitable for thin-walled ware.The clay mineral section of the Deutsche Keramische Gesellschaft tested various methods for quantitative clay mineral analysis. More than 20 laboratories used the following methods: x-ray analysis, dilatometer analysis, D.T.A., dehydration curves, microscopic analysis, and the determination of free silica by solution in phosphoric acid.By the investigation of mixtures made up of the purest quartz, feldspar, halloysite, illite, kaolinite, montmorillonite and “fire-clay” mineral, the correct values were found for the most part within a few percent.In the investigation of natural clays, greater differences were found, amounting to as much as 10 percent. Von Engelhardt especially investigated the errors arising with Geiger counter x-ray equipment.
Intracrystalline Swelling, Cation Exchange, and Anion Exchange of Minerals of the Montmoril-Lonite Group and of Kaolinite
Authors: Hofmann Ulrich , Weiss Armin , Koch G. , Mehler A. , Scholz A. 
Published: August 2006

AbstractThe structural formulas were determined of very pure specimens of montmorillonite, bei-dellite, saponite, nontronite, hectorite, wolchonskoite, vermiculite, and batavite. The lattice perfection of these minerals and the nature and variation of their crystalline swelling depend significantly on the surface density of the exchangeable cations between the silicate sheets.In a neutral solution of NH4F, OH ions were replaced by F ions. The exchange capacity is smaller the greater the diameter of the silicate layers of the various montmorillonite minerals. Since the anion-exchange capacity of nontronite can be increased through oxidation of Fe2 it is probable that the exchangeable OH ions are located on the boundaries of the octahedral layers.With kaolinite, the cation-exchange capacity decreases with increasing thickness of the crystal plates. The OH ions of the basal surface can be exchanged with F ions, which leads to the destruction of the lattice.A one-dimensional Fourier synthesis of K-batavite, like the investigations of Walker on vermiculite and of Brown and also Méring on montmorillonite, provides confirmation of the structure and enables the lattice positions of the K ions to be determined.
Regularly Interstratified Montmorillonite-Chlorite in Basalt
Authors: Earley J. W. , Milne I. H. 
Published: August 2006

AbstractThe dominant clay mineral in an amygdaloidal basalt from Mozambique is a mixed-layer variety having a highly regular alternation of montmorillonite-like and chlorite-like layers. The montmorillonite-chlorite occurs in the amygdules as green rosettes having a fine fibrous structure.X-ray examination of this mineral shows a long spacing of about 29 A in air and a fairly well-developed sequence of basal spacings. The long spacing shows some variation which is dependent on the relative humidity of the air surrounding the sample. The montmorillonite-like layers expand with glycerol and contract with heat treatment similar to montmorillonite, while the chiorite-like layers show modified reflection intensities on heating similar to chlorite. The mineral shows a 31.7 A spacing when glycerol saturated and a 23.3 A spacing when fully dehydrated.
Surface Conductance of Sodium Bentonite in Water
Authors: van Olphen H. , Waxman M. H. 
Published: August 2006

AbstractThe concept of surface conductance and its role in the interpretation of the formation resistivity factor of reservoir rocks is reviewed.The specific surface conductance of a clay is determined for four narrow particle-size fractions of sodium Wyoming bentonite in conductivity water. The values are derived from the specific conductance of gels of these clays on the basis of the picture of an idealized cubic network structure of the clay plates. The average surface conductance for internal and external surfaces of the bentonites is found to be 3.2 × 10−19 ohm−1, which is 0.55 × the value expected when all exchangeable ions are assigned their infinite dilution mobility. The data are independent of particle size.In addition, conductivity data are presented for clay suspensions in a wide range of concentrations. In extremely dilute suspensions, the contribution of the clay to the conductivity when expressed per unit weight of clay (the so-called “weight conductance”) is smaller than expected from an independent movement of particle and counter ions. This is interpreted to be partly a result of both electrophoretic and relaxation retardation, indicating that the electrical double layer on sodium bentonite has a condensed character. Probably part of the counter ions are entirely immobilized by adsorption on the surface.With increasing clay concentration, further compression of the double layer increases the retardation effects and a further decrease of the weight conductance is observed. A minimum is reached at a concentration of a few tenths of one percent clay at which, according to viscosity and light absorption data, particle interaction becomes apparent. At this point, immobilization of the particles and bridging between the electrodes gradually eliminate the retardation effects, and surface conductance takes over. The weight conductance increases gradually until a constant value is reached in a concentration range of 5 to 12 g of clay per 100 ml gel, from which the above value of the specific surface conductance was computed.
Heterogeneity in Montmorillonite
Authors: McAtee James L. 
Published: August 2006

AbstractX-ray diffraction patterns and cation-exchange data are presented for centrifuged Wyoming bentonite to demonstrate the heterogeneous nature of montmorillonite. It has been shown that in the bentonite samples studied, the montmorillonite can be separated into at least two fractions. One phase consists of essentially a sodium montmorillonite while the other consists of essentially a calcium-magnesium montmorillonite. It is postulated that these differences occur because of differences in the isomorphous substitutions within the montmorillonite crystal lattice.
Experimental Studies on Micas: A Synthesis
Authors: Yoder Hatten S. 
Published: August 2006

AbstractThe principal end members of the micas believed to be common in sediments have been synthesized and some of their stability relations determined. The polymorphs of muscovite and paragonite, the principal dioctahedral end members, obtained were 1Md, 1M and 2M1, and those of phlogopite and annite, the principal trioctahedral end members, 1Md and 1M or 3T. The range of stability of each of the polymorphs could not be fixed accurately because of the slow rate of transformation; however, the transformations 1Md → 1M → 2M1 were effected for muscovite and paragonite and 1M → 1Md or 3T and 2M1 → 1M or 3T for phlogopite. The growth characteristics of these micas in the laboratory are believed to be analogous to the formation of micas in sediments.Knowledge of the synthetic mica.s contributes greatly to an understanding of the natural materials called illite, hydromica, and high-silica sericite. The dioctahedral members of these materials and related minerals may be delineated accurately in the system muscovite—Al-celadonite—pyrophyllite and their iron analogues. The trioctahedral members of some of the same materials may be outlined in the system phlogopite— eastonite—tale and their iron analogues. The postulated substitution schemes in these systems are mainly MgSi ⇌ AlVIAlIV, KAl ⇌ Si, and H3O ⇌ K. In materials intermediate between these systems, such as most biotites and vormiculites, the substitution of 3Mg ⇌ 2AlVI is of major importance. The mixed-layer structures involving micas are elucidated.
Reactions of Feldspar and Mica with Water at Low Temperature and Pressure
Authors: Garrels R. M. , Howard Peter 
Published: August 2006

AbstractMuscovite and K-feldspar (adularia) were dry-ground to — 200/inch particles, which were suspended in water. These suspensions were “titrated” with KCl, and the pH was recorded as a function of KCl concentration and temperature. The results indicate that muscovite and adularia react with water to produce a surface film in which H+ has displaced K+. The “titration” curves show some characteristics attributable to exchange reactions, others apparently related to equilibria among solids of fixed composition. Maximum release of K+ from adularia by reaction with water is much greater than that from mica. The interpretation is made that the first result of reaction of mica and adularia with water is a surface layer that grades from an outer portion that is structurally disrupted to an inner portion that retains the original silicate structure but with H+ substituted for K+. Addition of K+ as KCl to the suspending solution displaces H+ from the disrupted zone, but all H+ originally taken up by the solids was not returned to the solution by concentrations of KCl up to 1.0 M. Experiments were of a few hours duration; work by others has shown that the disrupted zone releases appreciable concentrations of silica and alumina to solution over longer time intervals.These hydrolysis experiments indicate that at 25°C an H-feldspar or H-mica structure is favored over a K-feldspar or K-mica structure except in solutions in which the ratio of aK+ aH+ exceeds 109–10 or 107–8 respectively. These ratios decrease in the temperature range 25-65°C by a factor of about 100.7. These results, where considered in relation to the observed behavior of feldspar and mica under weathering conditions, indicate that the major energy change for the reactions, $2\,mica + 5{H_2}O = \,3\,kaolin + \,2{K^ + }\, + \,2O{H^ - }$$3K - feldspar + 2{H_2}O = \,K - mica + 6quartz + \,2O{H^ - }$ can be considered to result from H+-K+ exchange, and that the energy contribution from other changes is small.
Factors Affecting Clay Formation
Authors: Barshad Isaac 
Published: August 2006

AbstractBarshad’s method of calculating clay formation from the chemical analyses of the whole soil, the clay fraction, the nonelay fraction, and the mechanical analysis was applied to a large number of soils to determine the effect of climate, topography, parent material, vegetation and time on amount of clay formation. The amount of clay formed from 100 g of the nonclay fraction of the parent material was used as the yardstick for comparing clay formation in the different soils.It was found that for a true evaluation of the effect of these factors on clay formation, it is necessary to determine clay formation in every horizon of a profile and that all soil profiles should be sectioned into horizons which are as nearly alike in thickness as possible. Maximum clay formation in a soil profile occurs in the horizon which is about 2–10 in. below the surface rather than at the immediate surface; as a rule, the amount of clay forming decreases below this maximum horizon. An increase in moisture and temperature enhances clay formation. The temperature factor mainly affects clay formation in the Great Soil Groups in the following order: Podzols < Gray Brown Podzols < Brown Earths < Chernozems < Prairies < Red and Yellow Earths (Latosols) < Laterites. Poor drainage enhances clay formation. Grass-type vegetation is more effective in clay formation than tree-type. Clay formation is greater from the finer grained and the more basic rocks. The more easily rocks fragment, the more clay is formed. The increase in age of a soil is believed to be expressed in the same manner as an increase in the intensity of clay formation, namely, as an increase in clay formation with depth and as an increase in the thickness of a soil profile. It was concluded that clay formation is relatively slow: clay forms at a rate ranging from 0.00001 g to 0.002 g of clay per year per 100 g parent material or from 0.6 to 120 lb of clay per acre foot of parent material per year.
Forces Between Suspended Bentonite Particles Part II—Calcium Bentonite
Authors: van Olphen H. 
Published: August 2006

AbstractIn a previous paper (van Olphen, 1956) data were presented for the rheological and sedimentation behavior of sodium bentonite suspensions in water. From these data particle interaction energies were derived. Analogous data have been collected for calcium bentonite suspensions. It was observed that more clay is required to obtain a gel or a certain sediment volume with calcium bentonite than with sodium bentonite. This result can be quantitatively interpreted on the basis of a larger average particle thickness in the calcium bentonite suspensions. It is furthermore concluded that the interparticle forces are of the same order in both calcium and sodium bentonite suspensions.