Clays have played an important role in medicine since the dawn of mankind and are still applied widely as active ingredients and/or excipients in pharmaceutical formulations. Due to their outstanding properties of large retention capacity, swelling and rheological properties, and relative low cost, they have been used widely as advanced carriers for the efficient delivery of drugs by modifying their release (rate and/or time), increasing the stability of the drug, improving the dissolution profile of a drug, or enhancing their intestinal permeability. In addition, recent studies have shed new light on the potential of clay minerals in the nanomedicine field due to their biocompatibility, beneficial effects of clay nanoparticles on cellular adhesion, proliferation, and differentiation. Use as active ingredients and excipients are exerted via the oral and topical administration pathways. Skin drug delivery represents an attractive alternative to the oral route, providing local and/or systemic drug delivery. Due to their complex structures, however, most drugs penetrate the human skin only with difficulty. Enormous efforts have been invested, therefore, in developing advanced drug delivery systems able to overcome the skin barrier. Most strategies require the use of singular materials with new properties. In particular, and on the basis of their inherent properties, clay minerals are ideal candidates for the development of intelligent skin drug delivery systems. In this article, the properties of clay materials and their use in the skin-addressed pharmaceutical field are reviewed. A brief introduction of skin physiology and biopharmaceutical features of penetration by a drug through the skin layers is also included and is designed to shed light on the optimum properties of ideal nanosystems for advanced skin drug delivery. Special attention is devoted to the pharmacological functions of clays and their biomedical applications in pelotherapy, wound healing, regenerative medicine, antimicrobial, and dermocosmetics.

Clay, or more precisely, certain clay typologies, have been used traditionally by humans for therapeutic, nutritional, and skin-care purposes though they may be responsible for some relatively rare but significant health and skin-care risks. For example, clay particles could adsorb and make available for elimination or excretion any potential toxic elements or toxins being ingested or produced, but they could also adsorb and make available for incorporation, through ingestion or through dermal absorption, toxic elements, e.g. heavy metals. Geophagy has been observed in all parts of the world since Antiquity, reflecting cultural practices, religious beliefs, and physiological needs, be they nutritional (dietary supplementation) or as a remedy for disease. Some clays and clay minerals are employed widely in both the pharmaceutical and cosmetics industries as active compounds/agents and as excipients. In the biomedical field, some clay minerals such as halloysite and montmorillonite are known for their effective role as carriers for the control and sustainable delivery of active drug molecules, and in the biomaterials field some clay minerals are used for scaffold, hydrogel, foam, and film production. Constraints, both chemical and microbiological, on the use of clay-based products for therapeutic and cosmetic topical applications are generally imposed by sanitary regulations, and some solutions are proposed herein to control and reduce such restrictions. Particular emphasis is placed here on peloids and pelotherapy, as well as on manipulated and modified peloids, and specifically on tailored peloids or ‘designed and engineered’ peloids, and their derivatives, bactericidal peloids and ointments. As far as the so-called ‘killer clays’ are concerned, their pre-requisites, mechanisms of action, and disinfection role are also enhanced. Podoconiosis is an environment-related or geochemical disease that occurs in tropical highland areas, and is caused by long-term exposure of bare feet to volcanic, red-clay soil and affects some people, particularly those working in agriculture in some regions of Africa, Asia, and South America.

Submicroscopic intergrowths of K biotite, Na biotite and intermediate Na-K biotite from a schist near Málaga (Betic Cordilleras, Spain) were discovered using high-resolution transmission electron microscopy and analytical electron microscopy. The sample was also studied with X-ray diffraction, electron microprobe analysis, and scanning electron microscopy. Scanning electron microscopy revealed that the Na-enriched biotite is concentrated in albite-rich microdomains, albite being partially replaced by biotite. These images also revealed that both K and Na-K biotite grains appear locally retrograded to kaolinite. Transmission electron microscopic data indicated that K biotite, Na biotite and Na-K biotite form parallel or subparallel packets with interfaces parallel to the basal planes of biotite. Potassium biotite forms thick packets, chemically homogeneous, with a basal spacing of 10.1 Å. Sodium biotite also occurs as chemically homogeneous stacks of layers with a 9.78 Å periodicity. Sodium-K biotite shows, on the contrary, variable composition and basal spacings intermediate between K and Na biotites. Analytical electron microscopic data revealed important chemical differences between Na and K biotites, which affect both the tetrahedral and the octahedral sheets. Both electron microprobe analysis and analytical electron microscopy indicated that the trioctahedral micas show relatively low interlayer occupancy, suggesting the presence of H3O+ replacing the interlayer cations. Partial hydration of biotite explains the presence of a weak 14 Å reflection in the X-ray patterns. Both chemical and textural data suggested that these trioctahedral micas grew during a common prograde metamorphic episode, the phases with intermediate composition probably being metastable.

Graphite phase carbon nitride (g-C3N4) is a non-metal semiconductor material with a suitable band gap (2.7 eV) for visible photocatalysis. However, the high cost of relevant synthesis methods and poor adsorption performance have limited its practical applications. The objective of the present study was to mitigate these problems by synthesizing the g-C3N4 in the presence of exfoliated montmorillonite (Mnt). Compared with bulk montmorillonite, the specific surface area of exfoliated two-dimensional Mnt layers was significantly increased. As a result, the light transmittance of the lamella improved noticeably due to the fact that a freshly exposed surface had a large number of active reaction sites, making Mnt an excellent carrier for the photocatalyst g-C3N4. In order to improve the photocatalytic performance of g-C3N4, a series of g-C3N4/Mnt composites was prepared by a wet chemical method using Mnt nanolayers as the matrix. X-ray diffraction, infrared spectroscopy, Brunauer-Emmett-Teller nitrogen adsorption/desorption, transmission electron microscopy, and ultraviolet-visible diffuse reflectance spectroscopy were used to analyze the phase structure, the chemical bonds, the specific surface area and pore sizes, the morphology, and the light absorption characteristics of the composites, respectively. Rhodamine B (RhB) served as the target dye to test the photocatalytic degradation performance of the composites under visible light. According to the findings, the surface of the Mnt nanolayers was densely and uniformly covered by g-C3N4, forming a multi-layered stack structure. An increase of the calcination temperature improved the crystallinity of g-C3N4, leading first to densification and then to relaxation of the layered composite structure. Conversely, the band gap of the composite gradually decreased from 2.56 to 2.4 eV. Furthermore, temperature exposure changed the photocatalytic performance of the composite drastically. While the largest photocatalytic activity was observed at 610°C, it started to decrease with further heating of the composite. The complete degradation of RhB solution occurred after 2 h of visible light irradiation. The findings of the current study provide a scientific basis for the synthesis of a new generation of photocatalysts.

In order to develop high-performance adsorbents to remove toxic methylene blue (MB) from wastewater, palygorskite (Plg) was utilized as a template to prepare palygorskite/carbon (Plg/C) composites by using a hydrothermal reaction in the presence of glucose. The porous Plg/C composites were then activated with ZnCl2. The effects of the dose of the activator and the activation temperature on the crystal structure, micro-morphology, specific surface area, and adsorption performance of the porous Plg/C composites were studied systematically here. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results indicated that the crystal structure of Plg was destroyed during the activation process and irregular porous carbon was closely attached to the residual aluminosilicate skeleton. The activation was optimized at 400°C with a ZnCl2:Plg/C impregnation ratio of 2:1. The sample had a specific surface area of 1497.88 m2/g, together with a total pore volume and micropore volume of 1.0355 and 0.5464 cm3/g, respectively. The MB adsorption capacity was 381.04 mg/g. Such inexpensive, high-performance, porous Plg/C composites could find potential applications in wastewater treatment.

The potential use of near-infrared (NIR) spectroscopy as a characterization tool for organo-clays would be a great asset but little work has been done in this regard because the application of NIR to clay mineral studies is a relatively new phenomenon. The purpose of this study was to use NIR spectroscopy to investigate the effect of alkylammonium cations on the acid dissolution of a high-charge montmorillonite (SAz-1). Detailed analysis of the spectra of Li+-, TMA+- (tetramethylammonium), and HDTMA+- (hexadecyltrimethylammonium) saturated SAz-1 montmorillonite in the NIR region was achieved by comparing the first overtone (2ν) and combination (ν+δ) bands of XH groups (X = O, C) with the fundamental stretching (ν) and bending (δ) vibrations observed in the mid-infrared (MIR) region. Comprehensive analysis of the vibrational modes of CH3-N, CH3-C, and -CH2-C groups of TMA+ and HDTMA+ cations detected in the MIR and NIR regions was also performed. Both MIR and NIR spectra demonstrated that exchange of Li+ by TMA+ only slightly improved the resistance of SAz-1 layers to dissolution in 6 M HCl at 80°C, while exchange by the larger HDTMA+ cations almost completely protected the montmorillonite layers from acid attack. Use of NIR spectra in reaching these conclusions was crucial. Only in the NIR region could the creation of SiOH groups be monitored, which is an important indicator of the acidification of the montmorillonite surface. The OH-overtone region in the spectra of Li-SAz-1 and TMA-SAz-1 revealed that the SiOH band near 7315 cm−1 increases in intensity with enhanced acid treatment. In contrast, no SiOH groups were identified in the NIR spectra of HDTMA-SAz-1 treated in HCl, indicating that HDTMA+ completely covers the inner and outer surfaces of the montmorillonite and hinders access ofprotons to the Si-O− bonds created upon acid treatment.

Among all iron oxides, hematite (α-Fe2O3), goethite (α-FeOOH), and ferrihydrite (FeOOH⋅nH2O) are the most common mineral species. While immobilization of Mo6+ by surface adsorption on ferric oxides has been studied extensively, the mechanisms of incorporation in their structure have been researched little. The objective of this study was to investigate the relation between Mo content and its structural incorporation in hematite, goethite, and six-line ferrihydrite by a combination of X-ray absorption spectroscopy (XAS), powder X-ray diffraction (pXRD), and inductively-coupled plasma optical emission spectrometry (ICP-OES). Synthesized in the presence of Mo, the hematite, goethite, and six-line ferrihydrite phases incorporated up to 8.52, 0.03, and 17.49 wt. % Mo, respectively. For hematite and goethite, pXRD analyses did not indicate the presence of separate Mo phases. Refined unit-cell parameters correlated with increasing Mo concentration in hematite and goethite. The unit-cell parameters indicated an increase in structural disorder within both phases and, therefore, supported the structural incorporation of Mo in hematite and goethite. Analysis of pXRD measurements of Mo-bearing six-line ferrihydrites revealed small amounts of coprecipitated akaganéite. X-ray absorption near edge structure (XANES) measurements at the Mo L3-edge indicated a strong distortion of the MoO6 octahedra in all three phases. Fitting of extended X-ray absorption fine structure (EXAFS) spectra of the Mo K-edge supported the presence of such distorted octahedra in a coordination environment similar to the Fe position in the investigated specimen. Incorporation of Mo6+ at the Fe3+-position for both hematite and goethite resulted in the formation of one Fe vacancy in close proximity to the newly incorporated Mo6+ and, therefore, charge balance within the hematite and goethite structures.

Page 276: Change the average value of Cr in the ophiolitic rocks from 1850 ppm to 2530 ppm.

The effects of ultrasound treatment on the mean particle size, crystal structure, crystallite dimensions and specific surface area of natural muscovite and biotite samples have been investigated. Sonication of macroscopic flakes of muscovite and biotite produced a drastic particle-size reduction. The conditions for the preparation of micron and submicron-sized muscovite and biotite particles of narrow particle-size distribution by sonochemistry are described. The effect of sonication on particle-size reduction is more significant for muscovite than for biotite. Thus, for long sonication times (100 h), submicron and micron particles are predominant in muscovite and biotite, respectively. The resulting materials are crystalline, as assayed by X-ray diffraction, only broadening of the diffraction lines due to size-reduction was observed. Nuclear magnetic resonance studies revealed that the coordination of Al and Si was not modified by the treatment. Chemical analysis showed that the composition of the sample was not affected by the sonication except for a small contamination by Ti from the tip cup of the sonication instrument.

X-ray diffraction has been used to study the sorption of water by multilayer films containing ordered stacks of alternating layers of an organic polyelectrolyte and individual platelets of a smectite. The position and shape of the 001 reflections due to the ordered polyelectrolyte/platelet stacks were essentially the same when in air at low relative humidity (23–25% RH) and under water. These data indicate that swelling occurs exclusively in X-ray amorphous regions within the film, and that the ordered polyelectrolyte/clay domains themselves are not ‘swellable’ by water.

The fertility of soils with respect to K+ and NH4+ is often difficult to measure, but is essential for achieving effective agronomic practices. This problem is especially important in the Vertisols of Thailand. The purpose of the study reported here was to characterize the composition and layer-charge behavior of Thai Vertisols in order to understand better their K+ and NH4+ fertility. Topsoil and subsoil clay of 12 representative highly smectitic Vertisols from Thailand were studied. Interlayer swelling of smectite with alkylammonium cations, cation exchange capacity (CEC), and chemical composition were determined. These data and the re-expansion on glycerol treatment of Li-saturated, heated smectite demonstrated that high-charge, Fe-rich beidellite is the major clay mineral in these soils. The beidellite has a heterogeneous layer-charge distribution as measured by the alkylammonium method, with mean values ranging from 0.43 to 0.62 charges per half unit cell. The layer charge determined by CEC and structural formula methods for some almost pure smectites is smaller (0.32–0.54) and greater (0.46–0.69), respectively, than determined by the alkylammonium method. The structural formulae of beidellite confirm that the layer charge originates mostly in the tetrahedral sheet.

The Markan Passion narrative alludes to Ps 22 (LXX Ps 21) in reverse, culminating with Jesus’ cry: ‘My God, my God, why have you forsaken me?’ (Mark 15.34; cf. Ps 22.1). I argue that this ‘extended inverted allusion’ was an admired literary technique. Through select examples of this technique in the writings of the Hebrew Bible and Greco-Roman literature, I demonstrate its various functions—it can be employed to reverse meaning, to dissociate causation or to create new narrative trajectories. Reading Mark 15 in light of the literary functions of inverted allusion reveals new interpretive possibilities. In the Septuagint, Psalm 21 suggests that the psalmist's suffering was merited because of transgressions, but the inverted allusions to this Psalm in Mark 15 reinforce that Jesus’ suffering is unmerited (cf. Mark 15.10, 14) by decoupling the suffering from the transgressions. Additionally, in LXX Ps 21, the psalmist moves from forsakenness on account of transgressions toward divine deliverance. By alluding to this Psalm in reverse, Jesus travels the psalmist's journey in reverse. Rather than move from forsakenness toward divine deliverance, Mark's Jesus moves toward forsakenness, precisely to bring about divine deliverance.

Marriage is an institution that varies from religion to religion. For Hindus, it is an indissoluble union; for Muslims, a civil contract; and for Christians, a holy union. However, individual autonomy has entered the forefront through the Indian Constitution and the revolution in Indian family law.

The Constitution of India specifies that the people can decide who they should marry, who they should not, and with whom they want and don't want to continue their marital bond. The remedy of the restitution of conjugal rights (RCR), available under personal law, applies to those who are legally married but withdraw from marital ties without a reasonable excuse.

This study found that RCR is one-sided and used against the other spouse's will. However, the Supreme Court of India has decided that individual autonomy is needed to protect individual liberty and promote national interest, but it has also upheld the validity of RCR, creating a genuine controversy. The object of this paper is twofold—to analyze the individual autonomy enshrined under article 21 of the Indian Constitution, which is contrary to the right to RCR, and to explore this topic through a comparative law technique.

Natural clay-sized glauconite has the same mineralogical composition as sand-sized glauconite pellets but occurs in <2 μm clay fractions. This particular glauconite habit has been described previously from soil environments resulting from pelletal weathering but is rarely reported in higher-energy sedimentary environments. In the present study, clay-sized glauconite was identified as a common constituent in transgressive Neogene glauconite pellet-rich deposits of the southern North Sea in Belgium. X-ray diffraction results revealed that the characteristics of the clay-sized glauconite are very similar to the associated glauconite pellets in sand deposits. Both glauconite types consisted of two glauconite-smectite R1 phases with generally small percentages of expandable layers (<30%) with d060 values ranging between 1.513 Å and 1.519 Å. Clay-sized glauconite was not neoformed but formed by the disintegration of sand-sized glauconite pellets which were abraded or broken up during short-distance transport within the sedimentary basin or over the hinterland. Even in an environment where authigenic glauconite pellets occur, minimal transport over transgressive surfaces is sufficient to produce clay-sized glauconite. Furthermore, clay-sized glauconite can be eroded from marine deposits and subsequently resedimented in estuarine deposits. Clay-sized glauconite is, therefore, a proxy for the transport intensity of pelletal glauconite in energetic depositional environments and, moreover, indicates reworking in such deposits which lack pelletal glauconite.

In order to provide a theoretical foundation for the utilization of tailings as supplementary cementitious materials, the pozzolanic activity of muscovite—a typical mineral phase in tailings—before and after mechanical activation was investigated. In this study, significant pozzolanic activity of muscovite was obtained as a result of the structural and morphological changes that were induced by mechanical activation. The activated muscovite that was obtained after mechanical activation for 160 min satisfies the requirements for use as an active supplementary cementitious material, and the main characteristics of the pozzolana were as follows: median particle size (D50) of 11.7 μm, BET specific surface area of 28.82 m2 g−1, relative crystallinity of 14.99%, and pozzolanic activity index of 94.36%. Continuous grinding led to a gradual reduction in the relative crystallinity and an increase in the pozzolanic activity index due to the dehydroxylation reaction induced by mechanical activation, which occurred despite the fact that the specific surface area showed a decreasing trend when the grinding time was prolonged. Mechanically activated muscovite exhibited the capacity to react with calcium hydroxide to form calcium silicate hydrate, which is a typical characteristic of pozzolana. This experimental study provided a theoretical basis for evaluating the pozzolanic activity of muscovite using mechanical activation.

The relationship between vacant Mn structural sites in birnessites and heavy-metal adsorption is a current and important research topic. In this study, two series of birnessites with different average oxidation states (AOS) of Mn were synthesized. One birnessite series was prepared in acidic media (49.6–53.6 wt.% Mn) and the other in alkaline media (50.0–56.2 wt.% Mn). Correlations between the Pb2+ adsorption capacity and the d110 interlayer spacing, the AOS by titration, and the release of Mn2+, H+, and K+ during adsorption of Pb2+ were investigated. The maximum Pb2+ adsorption by the birnessites synthesized in acidic media ranged from 1320 to 2457 mmol/kg with AOS values that ranged from 3.67 to 3.92. For birnessites synthesized in alkaline media, the maximum Pb2+ adsorption ranged from 524 to 1814 mmol/kg, with AOS values between 3.49 and 3.89. Birnessite AOS values and Pb2+ adsorption increased as the Mn content decreased. The maximum Pb2+ adsorption to the synthetic birnessites calculated from a Langmuir fit of the Pb adsorption data was linearly related to AOS. Birnessite AOS was positively correlated to Pb2+ adsorption, but negatively correlated to the d110 spacing. Vacant Mn structural sites in birnessite increased with AOS and resulted in greater Pb2+ adsorption. Birnessite AOS values apparently reflect the quantity of vacant sites which largely account for Pb2+ adsorption. Therefore, the Pb2+ adsorption capacity of birnessite is mostly determined by the Mn site vacancies, from which Mn2+, H+, and K+ released during adsorption were derived.