bluuebunny/crossref_metadata_2025 huggingface dataset:
Managing Complexity at Dialysis Service Centers across Europe
Authors: Stopper Andrea , Amato Claudia , Gioberge Simona , Giordana Guido , Marcelli Daniele , Gatti Emanuele
Published: December 2006

Introduction: Dialysis is probably one of the areas of medicine with more guidelines than any other. Issues such as dialysis dose are dealt with in those guidelines, and minimum values to be reached are defined. A target has to be set and reached by using a data-driven continuous quality improvement (CQI) approach. Data collection must be programmed and structured from the beginning. Methods: Fresenius started its activities as a dialysis provider in 1996, following the merger of its dialysis business with the leading service provider in the US, National Medical Care. Currently Fresenius Medical Care’s European activities involve more than 320 dialysis centers located in 15 countries and treating more than 24,000 patients. Management is based on a bi-dimensional organization where line managers can rely on international functional departments. Under this framework, the CQI techniques are applied in conjunction with benchmarking in a system driven by quality targets. In order to combine clinical governance with management targets, the Balanced ScoreCard system was selected. The Balanced ScoreCard monitors the efficiency of each dialysis center compared to an ideal model, targeting maximum possible efficiency whilst having a unique target for patient outcomes. Conclusion: A clear definition of targets is fundamental and activities need to be monitored and continuously improved; scientific collection of clinical data is the key.
The CD11a Binding Site of Efalizumab in Psoriatic Skin Tissue as Analyzed by Multi-Epitope Ligand Cartography Robot Technology
Authors: Bonnekoh B. , Böckelmann R. , Pommer A.J. , Malykh Y. , Philipsen L. , Gollnick H.
Published: December 2006

Efalizumab (RaptivaTM) is an immunomodulating recombinant humanized IgG1 monoclonal antibody that binds to CD11a, the α-subunit of leukocyte function antigen-1 (LFA-1). By blocking the binding of LFA-1 to ICAM-1, efalizumab inhibits the adhesion of leukocytes to other cell types and interferes with the migration of T lymphocytes to sites of inflammation (including psoriatic skin plaques). Analysis of the response in patients treated with efalizumab to date shows that distinct groups of responders and nonresponders to the drug exist. It would therefore be of great practical value to be able to predict which patients are most likely to respond to treatment, by identifying key parameters in the mechanism of action of efalizumab. Detailed investigation and detection of multiple epitopes in microcompartments of skin tissue has until recently been restricted by the available technology. However, the newly developed technique of Multi-Epitope Ligand Cartography (MELC) robot technology combines proteomics and biomathematical tools to visualize protein networks at the cellular and subcellular levels in situ, and to decipher cell functions. The MELC technique, which is outlined in this paper, was used to help characterize the binding of efalizumab to affected and unaffected psoriatic skin as compared to normal control skin under ex vivomodel conditions. Efalizumab was labeled with fluorescein isothiocyanate and integrated into a MELC library of more than 40 antibodies. These antibodies were selected for their potential to detect epitopes which may be indicative of (a) various cell types, (b) structural components of the extracellular matrix, or (c) the processes of cell proliferation, activation and adhesion. Efalizumab bound to CD11a in affected psoriatic skin by a factor 15× and 32× higher than in unaffected psoriatic skin and normal control skin, respectively. CD11a and the efalizumab binding site were primarily expressed in the extravascular dermis, whereas CD54 (ICAM-1) as its ligand was most prevalent in the dermal vessels. T lymphocytes (for which the markers were CD3, CD8, CD4, and CD45R0) were the major cellular targets of efalizumab. In contrast, NK cells were only a minor target of efalizumab. Our study demonstrated that efalizumab represents a treatment for psoriasis that primarily targets memory CD4+ and CD8+ T cells and has a high specificity for psoriatic disease activity. Moreover, we hereby introduce the novel principle of a biological drug-binding biochip assay being especially useful for the future monitoring of psoriatic skin lesions under efalizumab treatment conditions.
Prospective Randomized Study Evaluating the Efficacy of the Spherical Adsorptive Carbon AST-120 in Chronic Kidney Disease Patients with Moderate Decrease in Renal Function
Authors: Shoji Tatsuya , Wada Akira , Inoue Kazunori , Hayashi Daisuke , Tomida Kodo , Furumatsu Yoshiyuki , Kaneko Tetsuya , Okada Noriyuki , Fukuhara Yoshifumi , Imai Enyu , Tsubakihara Yoshiharu
Published: December 2006

Aims: We studied whether adding the spherical adsorptive carbon AST-120 to conventional treatments is effective in inhibiting progression of chronic kidney disease (CKD) at the stage of moderate decrease in renal function. Methods: 43 CKD patients with moderately impaired renal function indicated by glomerular filtration rate (GFR) of 20–70 ml/min as measured by non-radiolabeled iothalamate clearance method were enrolled in the study. 26 patients showing a decrease of GFR by 5 ml/min during a 1-year observation period were randomized to receive ongoing treatments only (control group, 12 cases) or with AST-120 co-administered with ongoing treatment (AST-120 group, 14 cases). The intervention period was 1 year and the change in GFR was the primary evaluation variable. Results: The mean changes of GFR per month (ΔGFR) in the intervention period were not significantly different between both groups. However, when comparing the ΔGFR in the observation and intervention periods for each group, the rate of decline in GFR was significantly retarded (p < 0.001) in the AST-120 group while no significant difference was observed in the control group. Conclusion: These results suggest that co-administration of AST-120 with conventional treatments retards decline in renal function in CKD patients with moderate decrease in renal function.
Heme-Oxygenase Upregulation Ameliorates Angiotensin II-Induced Tubulointerstitial Injury and Salt-Sensitive Hypertension
Authors: Pradhan Ashok , Umezu Michio , Fukagawa Masafumi
Published: December 2006

Background: Heme oxygenase-1 (HO-1) has been implicated in the modulation of several diseases including hypertension (HTN) and renal injury. The tubulointerstitial (TI) injuries are supposed to be the main determinants for the development of salt-sensitive HTN. Therefore, this study examined the role of HO-1 in angiotensin II (AngII)-induced TI injury and salt-sensitive HTN. Methods: Sprague-Dawley rats on a high salt diet were treated by AngII infusion plus either hemin, an inducer of HO-1, or hemin + zinc protoporphyrin, a HO-1 inhibitor, for 2 weeks, and then followed for 6 weeks. Results: The AngII infusion resulted in acute HTN and proteinuria. Light microscopy revealed focal areas of tubular atrophy with mononuclear cell infiltration and interstitial expansion. The overexpression of osteopontin and TGF-β1 accompanied by diminished expression of rat endothelial cell antigen-1, the hallmarks of TI injury, were observed. At 2 weeks, all interventions were withdrawn and systolic blood pressure returned towards normal. After a brief normal salt diet, rats were again placed on high salt diet, resulting in progressive increase in systolic blood pressure in the HO-1-inhibited group. Conclusion: The induction of HO-1 attenuated the development of HTN, suggesting that HO-1 plays a crucial role in significant attenuation of AngII-mediated TI injury and resultant salt-sensitive HTN.
Long-Term Outcome of Patients with Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency
Authors: Bachelot Anne , Plu-Bureau Geneviève , Thibaud Elisabeth , Laborde Kathleen , Pinto Graziella , Samara Dinane , Nihoul-Fékété Claire , Kuttenn Frédérique , Polak Michel , Touraine Philippe
Published: December 2006

Aims: Conflicting results exist regarding bone mineral density (BMD), metabolism and reproductive function of adult patients with congenital adrenal hyperplasia (CAH). We evaluated the long-term outcome and the impact of chronic glucocorticoid replacement in these patients. Methods: Physical characteristics, serum hormone concentrations, BMD and metabolism were studied in 45 consecutive CAH adult patients. Results: Among the 36 women, only 14 (39%) had regular menses. Among the 27 women with classical CAH, the mean number of surgical reconstructions of virilized genitalia was 2.1 ± 0.2. Twenty of them (74%) were sexually active. Three men presented with testicular adrenal rest tumors. Twenty-five patients (55%) had decreased BMD at the femoral neck and/or at the lumbar spine. BMI was correlated with the BMD T-score at the femoral neck (p < 0.001) and at the lumbar spine (p < 0.01). Hydrocortisone dose was negatively correlated with the BMD T-score at the femoral neck (p = 0.04). Subjects with osteopenia had a significantly lower BMI and received higher hydrocortisone dose than those with normal BMD. Overweight was found in 21 patients (47%). There was a significantly positive correlation between HOMA and BMI (p < 0.001), and between HOMA and 17-OHP levels (p = 0.016). Conclusions: Adult patients with CAH treated with long-term glucocorticoids are at risk for decreased BMD, increased BMI, and disturbed reproductive function.
Enhanced Expression of the Homeostatic Chemokines CCL19 and CCL21 in Clinical and Experimental Atherosclerosis
Authors: Damås Jan K. , Smith Camilla , Øie Erik , Fevang Børre , Halvorsen Bente , Wæhre Torgun , Boullier Agnes , Breland Unni , Yndestad Arne , Ovchinnikova Olga , Robertson Anna-Karin L. , Sandberg Wiggo J. , Kjekshus John , Taskén Kjetil , Frøland Stig S. , Gullestad Lars , Hansson Göran K. , Quehenberger Oswald , Aukrust Pål
Published: December 2006

Objective—

Based on their role in T-cell homing into nonlymphoid tissue, we examined the role of the homeostatic chemokines CCL19 and CCL21 and their common receptor CCR7 in coronary artery disease (CAD).

Methods and Results—

We performed studies in patients with stable (n=40) and unstable (n=40) angina and healthy controls (n=20), in vitro studies in T-cells and macrophages, and studies in apolipoprotein-E–deficient (ApoE
−/−
) mice and human atherosclerotic carotid plaques. We found increased levels of CCL19 and CCL21 within the atherosclerotic lesions of the ApoE
−/−
mice, in human atherosclerotic carotid plaques, and in plasma of CAD patients. Whereas strong CCR7 expression was seen in T-cells from murine and human atherosclerotic plaques, circulating T-cells from angina patients showed decreased CCR7 expression. CCL19 and CCL21 promoted an inflammatory phenotype in T-cells and macrophages and increased matrix metalloproteinase (MMP) and tissue factor levels in the latter cell type. Although aggressive statin therapy increased CCR7 and decreased CCL19/CCL21 levels in peripheral blood from CAD patients, conventional therapy did not.

Conclusions—

The abnormal regulation of CCL19 and CCL21 and their common receptor in atherosclerosis could contribute to disease progression by recruiting T-cells and macrophages to the atherosclerotic lesions and by promoting inflammatory responses in these cells.
Inflammatory Response After Ischemic Stroke
Authors: Nighoghossian Norbert , Wiart Marlène , Cakmak Serkan , Berthezène Yves , Derex Laurent , Cho Tae-Hee , Nemoz Chantal , Chapuis François , Tisserand Guy-Louis , Pialat Jean-Baptiste , Trouillas Paul , Froment Jean-Claude , Hermier Marc
Published: December 2006

Background and Purpose—

The intensity of the inflammatory response may be related to the volume of acute infarction. Ultra-small superparamagnetic particles of iron oxide (USPIO) may enable assessment of neuroinflammation. We aimed to assess whether the intensity of the inflammatory response might be related to the subacute ischemic lesion volume.

Methods—

We enrolled patients who presented with acute anterior circulation stroke. MRI was performed at day 0, day 6, and day 9. The MRI protocol included T1-weighted imaging, gradient-echo T2*-weighted imaging, diffusion-weighted imaging, perfusion-weighted imaging and MR angiography. Blood-brain barrier disruption was defined as post-gadolinium enhancement on T1-weighted images. USPIO was administered after day 6 MRI. USPIO enhancement ratios were defined as the ratio between USPIO-related signal volume on day 9 T1-weighted imaging (respectively T2*-weighted imaging) and day 6 diffusion-weighted imaging infarct volume. The relationship between day 6 infarct volume and the enhancement ratio was assessed using Pearson and Spearman correlation tests.

Results—

The protocol was completed in 10 patients. Signal alterations after USPIO injection was observed in 9/10 patients on day 9 T1-weighted imaging and in 5/10 patients on day 9 T2*-weighted imaging. USPIO-related MRI enhancement was heterogeneous. Lesion volume on day 6 diffusion-weighted imaging had no impact on USPIO enhancement at day 9 according to the Pearson correlation test (
P
=0.39) or Spearman test (
P
=0.25). There was no relationship between blood-brain barrier disruption and USPIO enhancement.

Conclusions—

USPIO MRI enhancement is heterogeneous and not clearly related to subacute lesion volume.
Born Into Bastardy: The Out-of-Wedlock Child in Early Victorian Cape Town
Authors: Malherbe Vertrees C.
Published: December 2006

“Born into Bastardy” contributes to research into family life and law as it evolved in South Africa's “mother city” from the seventeenth century. It traces the legal framework in which illegitimacy occurred and the experience of out-of-wedlock children when the father was absent or negligent in providing support. Histories of illegitimacy lead to considerations of the destruction of unwanted children by abortion and infanticide, or their abandonment to custodial care. The early years of Victoria's reign coincided with the emancipation of slaves throughout the British Empire. The fact that Cape Town had been home to slaves for whom marriage was proscribed until very recent times affects significantly this account of children born into bastardy.
Wives Against Mothers: Women's Power and Household Dynamics in Rural Tunisia
Authors: Latreille Martin , Verdon Michel
Published: December 2006

This article examines the way women's power and its relation to household dynamics have been addressed in the anthropology of the Middle East and North Africa (MENA) through the classical works of Deniz Kandiyoti and Camille Lacoste-Dujardin. We argue that the notion of “classic patriarchy” they have elaborated and used is predicated on a “collectivistic” and “culturalist” perspective on living arrangements. We show the perspective's shortcomings and suggest an alternative, “atomistic” framework developed by one of the authors, which we adapt to the MENA. We finally assess the heuristic value of this framework by studying a Tunisian peasant village typical of the feminization of agriculture now taking place, a process through which women have gained power.
Early Modern State Formation, Patriarchal Families, and Marriage in Absolutist Spain: the Elopement of Manrique De Lara and Luisa De Acuña y Portugal
Authors: Espinosa Aurelio
Published: December 2006

The intercessory role of churchmen trained in jurisprudence was constitutive of state formation. Using religion and legal prescriptives, bureaucrats advanced the monarchical state into a regulator of disorderly behaviors and patriarchal initiatives about inheritance. This elopement case reveals the improvisational nature of the Castilian legal system that allowed individuals to defend personal preferences and to contest diverse levels of authority, from parental directives to regal decisions. The elopement revealed a tension between the aristocracy and the ecclesiastical government, and it catalyzed several important changes in early modern Spain. As religious experts debated the nature of marriage, their arguments about the consensual basis of the sacrament crystallized canonical ideas that later became inscribed in Tridentine formulations. When the Council of Castile decided to uphold the validity of the elopement, it took the debate out of the family realm and brought it into that of the nation-state.
An Evaluation of the Principles of Primogeniture and Inheritance Laws Among the Benin People of Nigeria
Authors: Ugiagbe Ernest Osas , Agbontaen-Eghafona Kokunre , Omorogiuwa Tracy Beauty Evbayiro
Published: December 2006

This article is a sociological analysis of the principles of primogeniture in Benin. It discusses the historical background of primogeniture in the Benin kingdom, examines the nature of the roles and rights of primogeniture in Benin prior to and after European contact, and evaluates changes in the system as a result of external contact. The work is a qualitative research project in which a number of Benin indigenes and custodians of Benin culture and tradition were interviewed. The analysis of results shows the effect of the principle of primogeniture in today's Benin society. The study makes recommendations on preventing family disorganization and unstable relationships that may stem from the current adherence to the principle.
Specific surface area and pore structure of allophanic soil clays
Authors: Paterson E.
Published: December 2006

Low temperature nitrogen adsorption has been used to study the external and internal structure of a number of allophanic soil clays. The results indicate that allophane, in addition to having pores in the intermediate size range (2–10 nm radius), contains micropores of < 1 nm radius. The occurrence of hitherto unreported micropores in allophanic clays has necessitated re-evaluation of the validity of specific surface area measurements.
Possible structure of halloysite disks and cylinders observed in some New Zealand rhyolitic tephras
Authors: Kirkman J. H.
Published: December 2006

The < 1·0 µm fractions of three rhyolitic tephras are shown to contain multifaceted squat cylinders of halloysite at various stages of development. The < 1·0 µm fraction of one of the tephras, the Pahoia Tuff, is composed mainly of large well-ordered squat cylinders, together with amorphous silica flakes, and novel disk-shaped particles of halloysite. The disks always occur sandwiched between silica flakes. A spiral structure is proposed for the disks. The squat cylinders are interpreted as having formed by a similar spiral mechanism to that of the disks, but without the constraining influence of silica flakes.
Nitrogen adsorption on synthetic akaganeite and its structural implications
Authors: Paterson E. , Tait J. M.
Published: December 2006

Comparison of the adsorptive properties of two samples of akaganéite prepared by different methods shows that a structural scheme based upon solid rods is much more likely than a previously proposed scheme involving tubes. Specific surface areas, qualitative and quantitative assessments of porosity' and electron micrographs strongly support this structure.
Etude de la repartition des cations interfoliaires dans les phlogopites alterees-(Na, Ca) et (Na, K)
Authors: Gaultier J.-P.
Published: December 2006

Resume

Les propriétés d'hydratation de phlogopites altérées-(Na,Ca) et -(Na,K) sont étudiées á l'aide des techniques de diffraction des rayons X. La comparaison du diagramme calculé d'après un modèle mathématique au diagramme expérimental permet de mettre en évidence un phénomène de démixtion des cations dans les espaces interfoliaires. Cette ségrégation est plus importante dans le cas des échantillons -(Na,K) que dans celui des échantillons -(Na,Ca). Une analyse quantitative du phénomène montre l'existence d'une ou de deux phases cristallines distinctes selon les teneurs en calcium ou en potassium. Les proportions relatives de ces deux phases ainsi que la composition de leurs espaces interfoliaires ont été déterminées. Un mécanisme élémentaire est proposé; il explique la présence et la composition de ces différentes phases.
Estimation of iron oxides in soil clays by profile refinement combined with differential X-ray diffraction
Authors: Brown G. , Wood I. G.
Published: December 2006

A procedure is described for the quantitative estimation of hematite, goethite and lepidocrocite in soil clays by differential X-ray diffraction combined with profile refinement. The method has been applied to clays from 12 palaeosol horizons from south-east England. Samples containing as little as 1% dithionite-extractable iron can be analysed in this way. The hematite: goethite ratio is determined to within ±3% for soil clays having ∼2.5% of each oxide and to within 10% in less favourable cases. The concentration of oxides in the soil determined solely from X-ray diffraction and from a combined chemical analysis/X-ray method are in good agreement. In addition to improving the accuracy and extending the range of iron-oxide concentrations over which analysis can be carried out, the method may, in principle, be used to provide information about the cell parameters and line profiles of each component present.
Differential behaviour of Fe(III)- and Cu(II)-montmorillonite with aniline: I. Suspensions with constant solid: liquid ratio
Authors: Moreale A. , Cloos P. , Badot C.
Published: December 2006

Aniline, adsorbed from aqueous solution in 1% (w/v) clay suspensions, forms coloured complexes and polymerizes on Fe(III)- and Cu(II)-montmorillonite. As evidenced by the adsorption isotherms, and the coloration and spectroscopic (IR, ESR) characteristics of the organo-clay associations formed, the conditions under which these reactions take place and the mechanisms involved differ according to the exchange cation. Fe(III) interacts with the π electrons of the aromatic ring to give rise to radical cations or so-called type II complexes, provided the aniline concentration does not exceed 500 p.p.m. With Cu(II). an aniline concentration above 500 p.p.m. is required and the reaction occurs at the amine group, proceeding through coordination followed by free-radical formation.
Complementarite des rayons X et de la microscopie electronique pour la determination des diverses phases d'une argile zincifere
Authors: Riviere M. , Rautureau M. , Besson G. , Steinberg M. , Amouri M.
Published: December 2006

Resume

Le remplissage des cavités karstiques de la région d'Ain Khamouda (Tunisie Centrale) est partiellement constitué d'une argile blanche. Son étude par diffraction X. ATD et analyse chimique traditionnelle montre qu'il s'agit d'un mélange d'halloysite prédominante et de smectite, renfermant plusieurs pourcents de ZnO. Une étude plus détaillée mettant en oeuvre un diffractométre à détecteur linéaire et à ambiance contrôlée, la microscopie électronique à transmission et la microscopie électronique à transmission en balayage (STEM) a permis de préciser les points suivants. En dehors de l'halloysite totalement dépouvue de zinc, il existe deux phases porteuses de ce métal: une sauconite et un hydroxyde de zinc à peu près amorphe. En outre, les faibles quantités (0.2%) de MgO contenues dans l'échantillon sont localisées à l'intérieur des tubes d'halloysite. De plus, ce minéral est présent sous la forme de deux phases, l'une hydratée, l'autre anhydre. Enfin, ces argiles renferment un peu d'argent sous la forme de microparticules de 3 à 10 nm de diamètre.
Diagenetic chlorite formation in some Mesozoic shales from the Sleipner area of the North Sea
Authors: Hurst A.
Published: December 2006

Diagenetic chlorite is forming as a result of temperature-controlled burial diagenesis in shales from the Sleipner area of the North Sea. Accompanying chlorite diagenesis, kaolinite and illite-smectite decrease in abundance, and illite increases in abundance. These clay mineral transformations occur between 122–126°C at temperatures higher than normally expected for chlorite diagenesis. Kaolinite and ordered illite-smectite are largely unaffected by diagenesis below 100°C. It is proposed that chlorite diagenesis is thus delayed due to the absence of a source of ions resulting from smectite decomposition. Clay mineralogy is of no lithostratigraphic use in the Jurassic sediments of the Sleipner area. However, the zone of chlorite diagenesis is a reliable indicator of maximum burial temperature.
Chemical, sorptive and morphological properties of montmorillonite treated with ammonium bifluoride (NH4HF2) solutions
Authors: Fijal J. , Zyla M. , Tokarz M.
Published: December 2006

The fluorination of montmorillonite by aqueous ammonium bifluoride solution (NH4HF2) has been investigated by chemical, sorptive, porosimetric and electron microscopic methods. Changes in the chemical composition of the montmorillonite during the fluorination were compared both in the crystal surface and in the bulk sample. The accumulation of fluorine was distinctly zonal, being present mainly in the surface layers. The electron microscope studies showed that the 300–400 nm thick macrodomains in the initial montmorillonite were cracked into small microdomains 20–30 nm in thickness, this resulting from disruption in the continuity of the octahedral sheets. These distinct changes in morphology of the montmorillonite aggregates particularly influenced the porosity and sorptive properties.
L'alteration lateritique debutante des pyroxenites de Jacuba, Niquelandia, Bresil
Authors: Colin F. , Noack Y. , Trescases J. -J. , Nahon D.
Published: December 2006

Resume

L'altération latéritique débutante des orthopyroxènes et clinopyroxènes de Niquelandia, Brésil, montre plusieurs stades. Le premier stade facultatif est la formation de produits ‘amorphes’ dont la composition chimique proche de celle des minéraux parentaux, montre déjà un enrichissement en nickel. Le deuxième stade est marqué par l'apparition de phyllosilicates dont la nature et la composition chimique varient selon le degré de porosité de la roche parentale. Cette porosité contrôle également la distribution du nickel dans les différents phyllosilicates, (saponite, talc, pimélite). Les pyroxènes ne contenant pas ou très peu de nickel, il est clair que le nickel qui s'accumule dans les produits de l'altération est totalement importé avec les eaux de percolation. L'origine de ce nickel est à rechercher plus haut dans les profils ou plus en amont dans la séquence, là où les dunites sont présentes.
A rapid method for the formation of Fe(II), Fe(III) hydroxycarbonate
Authors: Taylor R. M. , Schwertmann U. , Fechter H.
Published: December 2006

Dark blue-green Fe(II)Fe(III) hydroxychlorides and -sulphates were described by Feitknecht & Keller (1950) and later by Bernal et al. (1959). To further understand the formation and transformation of these compounds, Taylor & McKenzie (1980) and Taylor (1980) prepared Fe(II)Al(III) and Fe(II)Fe(III) hydroxychlorides, -sulphates and -carbonates by a more controlled hydrolysis reaction. These compounds, referred to as ‘green rusts’ by Bernal et al. (1959), are isostructural with hydrotalcite. However, the X-ray diffraction patterns can vary with the M(II)/M(III) cation ratio as it departs from the ideal value of 3, and with the interlayer anion.
Amphibole weathering in a glaucophane-schist (Île de Groix, Morbihan, France)
Authors: Proust D.
Published: December 2006

The weathering of two co-existing sodic (glaucophane) and calcic (actinolite) amphiboles in a glaucophane-schist was studied by optical microscopy. XRD and the electron microprobe. In the early stages of weathering, two trioctahedral expandable phases occur as internal weathering products in the amphiboles: a sodic saponite in the glaucophane and a calcic ‘hectorite’ in the actinolite. Further weathering leads to the replacement of the ‘hectorite’ by a calcic saponite in the actinolite, while the saponites formed in the weathered glaucophane exhibit progressive calcium enrichment in their interlayer sites. These observations demonstrate the influence of the primary mineral compositions on initial weathering products.
Retention duN-Paraoctylbenzenesulfonate de sodium par les argiles en presence d'electrolyte (KCl)
Authors: Siffert B. , Zundel J.-P.
Published: December 2006

Resume

Le mécanisme de rètention de l'octylbenzènesulfonate de sodium (OBSNa) en milieu aqueux pur sur les argiles correspond essentiellement à une précipitation du sel de calcium (OBS)2Ca. L'adsorption, proprement dite, atteint à peine 2 à 3µEq/g d'argile. En présence de KCl, la part de l'adsorption devient plus importante à cause de l'augmentation de la solubilité du sulfonate de calcium. L'affinité des monomères du tensio-actif pour l'interface solide-liquide est accrue. On montre que l'adsorption varie avec les propriétés de l'argile, en particulier, avec le nombre et la nature de ses cations échangeables. L'équilibre d'adsorption dépend de l'état d'avancement des réactions d'échange entre les cations échangcables de l'argile, les cations apportés par l'électrolyte (KCl) et le monomère (Na+), et les cations adsorbés sur les micelles. II existe, pour chaque argile, une concentration limite en KCl, d'autant plus grande que la teneur en calcium de l'argile est élevée, et à partir de laquelle le tensio-actif ne précipite plus. La rétention se fait alors uniquement par adsorption. Suivant les conditions de pH, elle a lieu sur les cations échangeables de l'argile et les sites positifs à la périphérie des cristaux (kaolinite) ou seulement sur les cations échangeables (illite et chlorite). Dans les procédés de récupération assistée du pétrole, l'addition de chlorure de potassium au fluide de balayage permettra de réduire la précipitation du tensio actif. Même, si l'adsorption augmente, cet effet est souvent suffisant pour que, globalement, la rétention diminue.
The influence of aluminium on iron oxides: XII. High-resolution transmission electron microscopic (HRTEM) study of aluminous goethites
Authors: Mann S. , Cornell R. M. , Schwertmann U.
Published: December 2006

Aluminium-substituted goethites are found in many soils and can also be synthesised readily in the laboratory. In recent years, synthetic substituted goethites have been examined by various techniques including XRD, IR, TEM and dissolution kinetics (Thiel, 1963; Jonas & Solymar, 1970; Fey & Dixon, 1981; Fysh & Fredericks, 1983; Schulze & Schwertmann, 1984; Schwertmann, 1984). Transmission electron microscopy (TEM) studies have shown that as Al substitution rises above 10%, the goethite needles become shorter and also thicker in the a direction. Furthermore, crystals which at zero substitution consist of domains parallel to the c axis become less domainic with increasing Al substitution (Schulze & Schwertmann, 1984).
Some observations on the relationship between etch-pit form and structure in biotite
Authors: Medina J. A. , Morante M. , Leguey S. , Tornero J.
Published: December 2006

The object of this study was to find a structural explanation for the corrosion figures produced in biotites having different chemical compositions and to apply this information to other di- or trioctahedral micas. The biotites investigated were used in earlier studies of epitaxial growth, so that previous knowledge of their surface behaviour was available. The biotites studied were from Evje, Norway (number 1), Guomum, Czechoslovakia (number 2), and Tanokami Yama, Japan (number 3). All were very dark in colour due to their high iron content.
Determination of layer-charge density of expandable 2:1 clay minerals in soils and loess sediments using the alkylammonium method
Authors: Rühlicke G. , Niederbudde E. A.
Published: December 2006

The alkylammonium adsorption method for the determination of layer-charge density was slightly modified and applied to mixtures of expandable clay minerals (i.e. predominantly 18 Å minerals after glycerol sorption) from two loess samples and two soils (Haplaquept and Aquentic Chromudert) having different K-adsorption properties. The layer-charge density of the so-called 18 Å minerals from these sediments and soil samples varied between −0·23 and −0·85 per formula unit, which suggested the presence of different amounts of vermiculite within the 18 Å minerals. The amounts of these vermiculites were related to K-fixing and K-buffering properties of the different samples. High-resolution electron micrographs of vermiculites saturated with tetradecylammonium exhibited a basal spacing of 25 Å. It was confirmed, that the alkylammonium ions in the interlayers of the vermiculites formed a paraffin-type structure. In the fine clay from the loess samples an interstratification of vermiculite and illitic layers was observed.
The porosity of deferrated montmorillonites: ethanol and methylbromide sorption
Authors: Stul M. S.
Published: December 2006

Comparative porosity studies based on nitrogen sorption isotherms were carried out on six freeze-dried Na-montmorillonites (Moosburg, Camp Berteau, Marnia, Greek Yellow, Greek White, Wyoming bentonite), untreated and deferrated with dithionite/citrate. Mesopore analysis was carried out using the ‘parallel-plate model’; for supermicropores the ‘MP’ method was used. Most of the surface area was located in the supermicropores (width 7–15 Å). Higher total surface areas of the deferrated clays resulted from a much higher supermicroporous surface area, while the mesopore surface was similar or smaller. The lower the charge density of a subfraction of deferrated Wyoming (Na-)bentonite, the lower the vapour pressure at which the interlamellar sorption of ethanol occurred. The results predict an expansion on contact with the first traces of ethanol at 298 K for a Na-smectite with a charge density ξ = 0·11 e/(Si,Al)4O10 unit. Compared with ethanol, methylbromide showed a weaker interaction with Na-smectite. At p/p0 = 0·4 only 18 % of the interlamellar zones of low-charged Laponite were penetrated; one third of the supermicropores of this smectite were not accessible to CH3Br.
Estimation de la composition chimique d'un phyllosilicate secondaire en equilibre avec une population homogene d'eaux
Authors: Aurousseau P. , Pages J.
Published: December 2006

Resume

Deux questions sont abordées: (1) Une eau naturelle étant donnée, peut-on considérer qu'elle est en équilibre avec un minéral de formule connue? (2) Un ensemble homogène d'eaux naturelles étant donné, peut-on considérer que ces eaux sont en équilibre avec un minéral? Si oui, Peut-on proposer une estimation de la composition de ce mineral? Nous proposons une méthode pour répondre à chacune de ces deux questions. Cette methode est appliquée à l'estimation de minéraux argileux de formule générale SiaAlbMgcCadKeNafOn(OH)m. Les données utilisées sont des eaux de percolation, dans des colonnes de sols.
Etude de l'interaction eau-kaolinite par mesure des permittivites complexes
Authors: Giuntini J. C. , Jabobker A. , Zanchetta J. V.
Published: December 2006

Dans le cadre de l'étude de l'interaction eau-kaolinite, des mesures de conductivité (pertes diélectriques) et de permittivités réelles ont été entreprises à fréquence variable (103–107 Hz) et en fonction de la température (27–80°C). La conductivité croît avec la fréquence et la température de mesures. L'utilisation d'un modèle de conduction par déplacement de protons par sauts discrets entre sites localisés est applicable. La loi σ′(ω) ∼ Aωs est vérifiée. L'évolution du paramètre s en fonction de la pression de vapeur d'eau permet de déterminer le mécanisme d'établissement de la monocouche d'eau sur le solide. La permittivité réelle décroît avec la fréquence. C'est une fonction croissante de la pression de vapeur d'eau. Un calcul simple permet de retrouver la loi expérimentale relative à la permittivité ɛ′ ∼ exp(K√P).
Occurrence of a ferrous, trioctahedral smectite in Recent sediments of Atlantis II Deep, Red Sea
Authors: Badaut D. , Besson G. , Decarreau A. , Rautureau R.
Published: December 2006

A trioctahedral, ferrous smectite has been located in the uppermost deposits of Atlantis II Deep, SW basin, Red Sea. This clay is very unstable when removed from its environment of formation and, for example, oxidizes during desiccation under laboratory conditions. Only X-ray transmission diffraction study of the mud itself demonstrates the trioctahedral character of the clay. Electron-optical investigation shows that oxidation within the octahedral sheet creates a juxtaposition of dioctahedral and trioctahedral sub-lattices in the same particle. Ferrous smectite authigenesis is located near the hydrothermal spring outlets of the Atlantis II Deep.
Occurrence of palygorskite in Tertiary sediments of western Egypt
Authors: Shadfan H. , Hussen A.A. , Alaily F.
Published: December 2006

The presence of palygorskite in soils and sediments of the Middle East countries has been widely reported: in Syria (Muir, 1951), Israel (Yaalon, 1955; Barshad et al., 1956; Ravikovitch et al., 1960; Singer, 1971; Singer & Amiel, 1974; Yaalon & Wieder, 1976), Iraq (Al-Rawi et al., 1967; Eswaran & Barzanji, 1974), Lebanon (Lamouroux et al., 1973), Jordan (Wiersma, 1970; Shadfan, 1983; Shadfan & Dixon, 1984; Shadfan et al., 1985) and Saudi Arabia (Aba Husayn & Sayegh, 1977; Elprince et al., 1979; Mashhady et al., 1980; Viani et al., 1983; Lee et al., 1983; Mackenzie et al., 1984; Shadfan & Mashhady, 1985). In Egypt, Elgabaly (1962) indicated the predominance of palygorskite in some of the soils in the western desert and proposed that the mineral had formed from calcareous argillaceous material in a saline lagoon. Hassouba & Shaw (1980) found palygorskite to be a major component of the clay fraction in caliche crusts in the coastal plain of north-western Egypt and considered that the palygorskite had formed authigenically in that environment.
The progressive illitization of interstratified illite-smectite from Carboniferous sediments of Northern England and its relationship to organic maturity indicators
Authors: Smart G. , Clayton T.
Published: December 2006

Interstratified illite-smectites from Carboniferous sediments from the Alston and Askrigg blocks and the intervening Stainmore trough of the northern Pennines, UK, were examined by XRD. Both blocks are underlain by Caledonian granites. During late Carboniferous times sediments overlying the Alston block were intruded by the Whin Sill. The percentage smectite in illite-smectite (%S in I/S) varies from ∼35% to <5% only homogeneous mudstones give consistent results. In the case of the Askrigg block and Stainmore trough, a good inverse correlation was found between %S in I/S and vitrinite reflectance. Both illitization of illite-smectite and vitrinite reflectance increase towards the centre of the block. This is thought to be related to high heat-flow centred about the granite basement. In the case of the Alston block, there is no direct relationship between clay and vitrinite data, vitrinite reflectance being controlled by the position and thickness of the Whin Sill. Except where close to the contact, the Whin Sill had no apparent effect on %S in I/S. As observed for the Askrigg block, %S in I/S is directly related to the position of the underlying granite. The progressive illitization of illite-smectites of low expandability is very slow when compared to vitrinite alteration in response to rapidly increasing temperature. Consequently, %S in I/S is a potential indicator of thermal maturation in situations where vitrinites, by virtue of their rapid response to increasing temperatures, fail to provide a regional view of heat-flow patterns.
The use of RbCl disks for the infrared spectroscopy detection of hydrated and dehydrated halloysite in mixtures with kaolinite
Authors: Mendelovici E. , Sagarzazu A.
Published: December 2006

A simple IR spectroscopy method for detecting hydrated and dehydrated halloysite in artificial mixtures with kaolinite is described. The method is based on the exclusive ability of RbCl among the alkali halides to form a complex with halloysite but not with kaolinite. This complex absorbs at 3500 cm−1 when hydrated halloysite or admixed halloysite is examined in RbCl disks, the limit of detection being 15% in the kaolin admixture. Heating the clay powders or corresponding RbCl disks at 110°C affects the 3500 cm−1 frequency. The development of this absorption band together with a decrease in the intensity ratio of the 3690/3620 cm−1 frequencies is proportional to increasing amounts of halloysite in the kaolin admixtures. This method has an analytical applicability and is relatively rapid.
Sorption of Ni, Zn and Cd on Sepiolite
Authors: Helios-Rybicka E.
Published: December 2006

The ability of clay minerals to adsorb heavy metal cations is an important property in the context of the increasing contamination of the aquatic environment and soils by toxic waste. Laboratory studies of the sorption of heavy metals by clays have mostly been carried out using montmorillonite and illite (Chester, 1965; Egozy, 1970; Bourg & Filby, 1974; Helios-Rybicka & Schoer, 1982), less frequently for kaolinite, and only rarely for mixed-layer illite-montmorillonite (Helios-Rybicka, 1983) and the fibrous clay minerals sepiolite and palygorskite. This note describes the sorptive behaviour of sepiolite towards Ni, Zn and Cd.
Some observations on pleochroism and idiophany in mineral plates
Authors: Crook T.
Published: December 2006

In this paper an attempt is made to state and explain, in a simple manner, the essential features of the phenomena which are seen when plates of pleochroie minerals are examined in ordinary light.

The pleochroie effects exhibited by minerals are usually studied in light of practically normal incidence. For the observation of facial colours, transparent crystals, or, better still, specially orientated cube-shaped pieces of minerals, are examined in ordinary light. In general, by this mode of observation, only facial colours are seen when ordinary light is used, and for the observation of axial colours the incident light must be polarized.
On the composition of a stone from the meteoric shower which fell at Dokáchi, Bengal, on October 22, 1903
Authors: Clarke H. E. , Bowman H. L.
Published: December 2006

On October 22, 1903, a considerable shower of meteoric stones occurred in the neighbourhood of the village of Dokáchi, situated near the mouth of the Ganges, in the Dacca district of Bengal. Seven of these stones, which had been obtained flom natives on the spot by Mr. H. E. Stapleton, M.A, of St. John's College, Oxford, Inspector of Schools in the Dacca district, were recently presented by him to the Oxford Museum.
On Schwartzembergite
Authors: Herbert Smith G. F. , Prior G. T.
Published: December 2006

The mineral schwartzembergito was first described by Domeyko in 1864 as an oxychloroiodide of lead from the Desert of Atacama. The specimens, which are said to have been collected about ten leagues from Paposo in the Desert of Atacama, at a mine worked for argentiferous galena, were brought to his notice by Dr. Schwartzemberg, an assayer at Copiapo, who had recognized the material as being an iodide of lead. Domeyko made a chemical analysis (see p. 82) of the mineral, a yellowish crust, 1 to 2 mm. in thickness, upon galena, and obtained the formula, 2Pb(CI,I)2.3PbO, the specific gravity being 5.7; no crystal measurements were obtainable, neither were any optical observations made.
Further remarks on the electrostatic separation of minerals
Authors: Crook T.
Published: December 2006

In a previous number of the Mineralogical Magazine (1909, vol. xv, p. 260), attention was called to a simple electrostatic method whereby, using a stick of sealing-wax and a copper plate, grains of minerals which have a metallic or sub-metallic lustre can generally be separated from those of the more transparent minerals, the former being attracted notwithstanding the fact that they are usually heavier than the latter.
An example of Quartz twinned on the primary rhombohedron
Authors: Drugman Julien
Published: December 2006

Examples of quartz twinned on a face of the primary rhombohedron R are extremely rare. Only three isolated examples have so far been recorded. The first was observed by Q. Sella; but as his crystal could not be measured, owing to its position on the matrix, it is of only slight importance as evidence of this mode of twinning of quartz.
The breccialion of mineral-veins
Authors: Butler Francis H.
Published: December 2006

Examination of a series of examples of vein-breccias demonstrates that while many have readily explicable characters in common, others differ from ordinary types, and exhibit peculiarities calling for special investigation.
Note on some artificially-produced crystals of Gypsum
Authors: Fletcher Mark
Published: December 2006

Professor H. Louis, of Armstrong College, handed over to me for examination some crystals of gypsum which had been sent to him by Mr. Frank E. Lott, A.R.S.M., F.I.C., of Burton-on-Trent. Mr. Lott has kindly furnished me with the following particulars.

The crystals were deposited in an apparatus employed for raising steam in the production of distilled water. This apparatus consists of a copper vessel enclosing steel steam pipes for heating the water. The crystals were deposited on the walls of the copper vessel and on the steel pipes, and had been formed within a period of twelve months.
Crystallographic constants and isomarphous relations of the double chromates of the alkalis and magnesium
Authors: Tutton A. E. H. , Porter Mary W.
Published: December 2006

The interesting results which have followed the investigation by one of us of the isomorphous series, of double sulphates and selenates of the general formuh, R′2M′′[(S, Se)O4]2.6H2O have led us to extend the investigation to the corresponding double chromates in which M is represented by magnesium.
On the frequent occurrence of Ankerite in coal
Authors: Crook T.
Published: December 2006

There occurs frequently in coal a white carbonate which, when it is referred to at all by scientific writers on coal, is usually described as calcium carbonate. It occurs as a rule in the form of thin layers infilling the joint-cracks which lie normal to the bedding-planes, though at times it may be seen infilling other divisional planes which may cut across the bedding obliquely.
A diagram for use with the total-reflectometer
Authors: Hutchinson A.
Published: December 2006

The accompanying diagram (Plate VIII) has been prepared in order to facilitate the determination of indices of refraction with the Kohlrausch total-reflectometer, by affording a means of rapidly werking out the results by a graphical method.

The Kohlrausch instrument enables measurements to be made of the critical angle θ, at which total reflection begins, when monochromatic light is reflected at the plane surface of a solid of refractive index μ immersed in a liquid of higher refractive index μ′.
The meteoric stones of El Nakhla El Baharia (Egypt)
Authors: Prior G. T.
Published: December 2006

According to the accounts which have been published by members of the Egyptian Geological Survey, a number of meteoric stones fell to earth on June 28, 1911, at about 9 in the morning, in the hamlets to the west and north of the village of El Nakhla El Baharia (31° 19′ N., 30° 21′ E.) in the district of Abu Hommos, about twenty-four miles east of Alexandria, Egypt.
Note on a large crystal of Anatase from the Binnenthal
Authors: Herbert Smith G. F.
Published: December 2006

Last year (1911) the Trustees of the British Museum acquired a large isolated crystal of anatase, which is of interest not only on account of its unusual size, but also because of the vicissitudes that, to judge from the furrowed appearance of certain faces, it had undergone in the course of growth. It was by far the largest of the many crystals of this species that were found in the previous year (1910) near the ridge Kollergraben in the district known to early mineralogists as Alp Lercheltini, probably at a spot named Spissen.