Large Amount Of Amorphous Material Research Articles

Phosphorylated Co(OH)2@NiFe-LDH core–shell heterostructure for highly efficient alkaline water splitting

The development of transition metal bifunctional electrocatalysts with high activity, stability and cost-effectiveness is necessary for the overall water decomposition. In this work, a phosphorylated core–shell heterostructure bifunctional catalytic material with a nickel foam carrier, a Co(OH)2 nanowire array core and an ultrathin NiFe layered double hydroxide (NiFe-LDH) shell is synthesized. The solid contact between the NiFe-LDH shell and the highly conductive Co(OH)2 core brings about excellent electrical connectivity and an integrated hierarchical nanostructure that greatly improves the active specific surface area. Meanwhile, the phosphorylated hierarchical core–shell nanostructure enables the presence of a large amount of amorphous material at the edges, which leads to excellent activity and stability for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER).

Morphological Modification of Carbon Nanoparticles after Interacting with Methotrexate as a Potential Anticancer Agent.

Production of highly penetrable and targetable drug delivery particles is mainly focused by current therapy and such focus is achieved in our present study. The carbon nanoparticle (CNP) prepared from purely natural source was modified from spherical shape to cylindrical floral like structure after treatment with the anticancer drug methotrexate (CM). The physiochemical properties of the CNP and CM was characterized using FT-IR/Raman Spectrometer, XRD, SEM, AFM, particle size analyzer and its biological evaluation using haemolysis and MTT assay. The shift in FT-IR peaks at 1592, 1120cm-1 and peaks of raman spectra observed at 1303, 1300cm-1 represents ordered carbon nanotubes. The morphological change from spherical to cylindrical floral like structure was observed using SEM and AFM and its particle size distribution analysis shows an average diameter of 269nm for CM. XRD peak at 2θ = 23.86° (002) indicates the presence of large amount of amorphous material that corresponds to multi-walled carbon nanotubes. Haemocompatibility studies proved the safety level usage as 100μg/ml and MTT assay shows viability rate of 85-98% with mouse embryonic fibroblast (NIH/3T3) and 30-45% with pancreatic carcinoma (MIA PaCa-2) and gastric cancer cell lines (SNU- 484) respectively.These results are also supported by phase contrast microscope images observed after staining with calcein AM and EthD-1. The morphologically modified CNPs has shown good anticancer, biocompatibility and haemocompatibility property which is an important criterion to be satisfied by a biomedical product.

Titanium silicalite-1 macrostructures for photocatalytic removal of organic pollutants from aqueous media

Titanium silicalite-1 (TS-1) structures in the form of macroscopic beads with hierarchical porosity were prepared by the resin templating method. The Ti content within the samples was varied between 1 and 7 wt%, with corresponding surface areas ranging from 725 to 350 m2 g−1, respectively. The samples contained a large amount of amorphous material, which was necessary to achieve high mechanical stability of the beads. The TS-1 macrostructures were used as catalysts for the photocatalytic degradation of methylene blue (MB), and results were compared to the results for a commercial anatase nanopowder (CristalACTiV™ PC500). All TS-1 beads showed similar MB degradation rates independently of their Ti content, which was linked to variations in the surface areas and structure. The macroscopic shape of the TS-1 beads allowed easy recovery from the mother liquor upon decolouration of the MB solutions, which was highly beneficial compared to the reference anatase nanopowder. The TS-1 beads could be reused in subsequent photocatalytic cycles after decanting exhausted solutions and replacing with fresh MB solutions without any energy-consuming regeneration steps involved. The samples were tested in five consecutive cycles and MB degradation rates remained broadly unchanged during all tests.

Natural mixture of silica and smectite as a new clayey material for industrial applications

AbstractThe main physico-chemical properties of a new smectitic clay containing large amounts of amorphous material are reviewed and potential industrial applications of this type of clay are discussed. Due to a 34% amorphous material content (natural silica gel), the investigated clay has very high porosity and can be used as it is or in acid-impregnated form for oil bleaching or phosphate reduction in edible oil. In the field of biodiesel purification, the new clay can be used to remove, in particular, mono-, diglycerides and glycerol. The natural silica-smectite mixture is also suitable as a carrier for liquid ingredients, for example in animal feeds, and might serve as a partial or complete substitute for synthetic precipitated silicas. In the field of bioseparation processes, the clay can be used as an adsorbent for protein separation by means of cation exchange. Due to the suppressed swelling (compared with smectite alone), it can be packed in columns which can be regenerated.

The roles of pedogenesis and diagenesis in clay mineral assemblages: Lower Cretaceous fluvial mudrocks, Nova Scotia, Canada

Clay mineral assemblages in alluvial mudrocks are important for paleoclimatic interpretation and for understanding burial diagenetic cementation in sandstones, but it is commonly difficult to unravel the relative importance of source weathering, pedogenesis and diagenesis in their origin. The clay mineral assemblages in fluvial overbank mudrocks from the Lower Cretaceous Chaswood Formation in central Nova Scotia, investigated by X-ray diffraction analysis of the < 2 µm fraction of 45 samples, include kaolinite, illite, vermiculite, and mixed layer kaolinite/expandable clay and mica/vermiculite. The assemblages vary with depositional facies. Wetland organic-rich mudrocks have large amounts of amorphous material and kaolinite is the dominant clay mineral. In the eastern part of the basin, where overbank mudrocks were episodically uplifted by syn-sedimentary strike-slip faulting, cumulate ultisol and alfisol paleosols are common. In the ultisols, hematite is enriched and kaolinite increases at the expense of illite in the B horizon. Alfisols contain more illite and vermiculite and the B horizon is enriched in goethite. In the western part of the basin, where thin sandstones with abundant diagenetic kaolinite cement are interbedded with the mudrocks, the distinctive clay mineral assemblage of mica/vermiculite mixed layer, vermiculite with 15.5 Å peak, and kaolinite/expandable mixed layer clay with a 17.7 Å peak is interpreted to result from bacterially-mediated oxidation of organic matter below the paleo-water table during early burial diagenesis. Deeper burial diagenesis may lead to slightly higher kaolinite crystallinity. Volcanic ash appears to alter to kaolinite/expandable mixed layer clay with a 7.9 Å peak. Comparison with the continuously subsiding and rapidly accumulated Wessex Formation of southern England, formed at a similar paleolatitude, shows the strong role of pedogenic processes and early diagenesis by meteoric water in development of clay mineral assemblages in the locally tectonically uplifted Chaswood Formation.

Role of multispecies microbial biofilms in the occlusion of biliary stents

Endoscopic stenting is a standard palliative approach for the treatment of a variety of diseases involving biliary obstruction. However, the major limitation of this approach is represented by stent occlusion followed by life-threatening cholangitis, often requiring stent removal and replacement with a new one. Although it is generally believed that microbial colonization of the inner surface of the stent plays an important role in initiating the clogging process, so far available data are not enough for a full understanding of this phenomenon. In fact, it is known that when a biliary stent is inserted across the sphincter of Oddi, the loss of the antimicrobial barrier represented by the sphincter itself and the low pressure in the common bile duct allow reflux of duodenal content, thus promoting an ascending microbial colonization. The sessile mode of growth and the exopolysaccharide production, which leads to the subsequent establishment of a thick biofilm, provides microorganisms with an efficient protection from both antibacterial agents and phagocytic cells. The aim of this study was to analyze the tridimensional structure of the microbial biofilm grown in the lumen of 15 clogged biliary stents and to identify the microbial species involved in the clogging process. Scanning electron microscopy investigations revealed that sludge present in the stent lumen consist of a rich and assorted microbial flora, including aerobic and anaerobic species, mixed with a large amount of amorphous material containing dietary fibres, crystals of cholesterol and other precipitates of bacteria-driven bile salts. Key words: biliary stent, biofilm, microbial colonization, stent occlusion

Characterization and determination of 28 elements in fly ashes collected in a thermal power plant in Argentina using different instrumental techniques

Different techniques were selected for comprehensive characterization of seven samples of fly ashes collected from the electrostatic precipitator of the San Nicolás thermal power plant (Buenos Aires, Argentina). Particle size was measured using laser based particle size analyzer. X-ray diffraction powder (XRD) analysis and scanning electron microscopy (SEM) were used to characterize the mineral phase present in the matrix consisting basically of aluminosilicates and large amounts of amorphous material. The predominant crystalline phases were mullite and quartz. Major and minors elements (Al, Ca, Cl, Fe, K, Mg, Na, S, Si and Ti) were detected by energy dispersive X-ray analysis (EDAX). Trace elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, V and Zn) content was quantified by inductively coupled plasma optical emission spectrometry (ICP OES). Different acid mixtures and digestion procedures were compared for subsequent ICP OES measurements of the dissolved samples. The digestion procedures used were: i) a mixture of FH + HNO 3 + HClO 4 (open system digestion); ii) a mixture of FH + HNO 3 (MW-assisted digestion); iii) a mixture of HF and aqua regia (MW-assisted digestion). Instrumental neutron activation analysis (INAA) was employed for the determination of As, Ba, Co, Cr, Ce, Cs, Eu, Fe, Gd, Hf, La, Lu, Rb, Sb, Sc, Sm, Ta, Tb, Th, U and Yb. The validation of the procedure was performed by the analysis of two certified materials namely, i) NIST 1633b, coal fly ash and ii) GBW07105, rock. Mean elements content spanned from 41870 μg g − 1 for Fe to 1.14 μg g − 1 for Lu. The study showed that Fe (41870 μg g − 1 ) ≫ V (1137 μg g − 1 ) > Ni (269 μg g − 1 ) > Mn (169 μg g − 1 ) are the main components. An enrichment, with respect to crustal average, in many elements was observed especially for As, V and Sb that deserve particular interest from the environmental and human health point of view.

Reissner’s Fibre in Rat: A Scanning Electron Microscope Study

Objective: To study the detailed morphology of Reissner’s fibre (RF) that lies on the floor of the fourth ventricle in an adult rat by scanning electron microscopy. Method: For these studies 7 Wistar rats weighing about 200 g were used. The animals were anaesthetised and perfused with 0.9% oxygenated saline followed by 3% glutaraldehyde. The brain stems were dissected out and processed for scanning electron microscopy. Observations: Scanning electron microscopic studies showed that the RF is longitudinally grooved and covered with fine granular material. At certain regions, cellular debris and large amounts of amorphous material are found attached to the RF. Interestingly, we have observed the presence of a knot-like swelling or convolution in the RF, in the fourth ventricle, prior to its entry into the central canal of the spinal cord, that has not been previously described. Furthermore, a dense network of supra-ependymal nerve fibres is found on the surface of the fourth ventricle, in the near vicinity of the RF. Conclusion: Although the functional significance of the knot-like structure is not understood, it is reasonable to believe that these structures may represent one of the regions of RF disintegration.

Disseminated cutaneous myxomas in an adult

New York, NY 10029 A 45-year-old Hispanic man presented with a 4-year history of progressively increasing numbers of skin-colored, nonpruritic papules on the trunk. His past medical history was significant only for hypertension. The patient had no systemic symptoms, and he had no family history of such lesions. Physical examination revealed approximately 100 round, dome-shaped, soft white to skin-colored papules scattered predominantly over the back, chest (Fig. 1), and abdomen; several papules were present on the lower extremities. There was no evidence of mucosal myxomas or mucocutaneous lentigines, ephelides, or nevi. The patient's physical appearance was normal, without evidence of Cushing's syndrome, excessive growth hormone, or any other endocrinopathies. Figure 1. Multiple cutaneous myxomas on the left chest Download figure to PowerPoint Laboratory investigation included the following: an echocardiogram was negative for cardiac myxomas; a chest X-ray was negative; and a stool guaiac was negative for blood. Serum protein electrophoresis was negative for paraproteinemia, and the levels of growth hormone, cortisol, and free testosterone were within normal limits. Baseline complete blood count (CBC), chemistry panel, thyroid function studies, erythrocyte sedimentation rate (ESR), antinuclear antibody, and urinalysis were unremarkable. A skin biopsy specimen revealed a large amount of amorphous bluish material separating collagen bundles within the upper and mid-dermis (Figs 2 and 3). Within this material, there were some small spindle-shaped and polygonal cells. An alcian blue stain demonstrated the abundance of dermal mucin. The diagnosis was compatible with cutaneous myxoma. Figure 2. Photomicrograph showing a large amount of amorphous material in the dermis (hematoxylin and eosin, ×400) Download figure to PowerPoint Figure 3. At higher magnification, small spindle-shaped and polygonal cells are seen in a mucinous stroma (hematoxylin and eosin ×40) Download figure to PowerPoint After 3 years of clinical follow-up, the patient has developed no other cutaneous lesions or systemic symptoms. The patient has refused further laboratory studies and echocardiography.

Ultrastructural studies of the cells forming amyloid in the cortical vessel wall in Alzheimer's disease.

Ultrastructural studies of serial sections of the vessels with amyloid deposits in the brain cortex of patients with Alzheimer's disease showed that cells in the position of pericytes--perivascular cells--and perivascular microglial cells are producers of amyloid fibrils in the vascular wall. Three types of changes from normal are distinguishable in the vessel wall: (1) semicircular or circular thickening of vascular wall containing a large amount of amorphous material and various number of amyloid fibrils, (2) tuberous amyloid deposits containing both amorphous material and amyloid fibrils, some of the fibrils being arranged in strata and others arranged radially, and (3) amyloid star composed of a predominantly radial arrangement of bundles of amyloid fibrils and a less prominent amorphous component. A mixture of amorphous material and amyloid fibrils is present in cell membrane invaginations of perivascular cells, and occasionally perivascular microglial cells. Bundles of amyloid fibrils are found in altered cisternae of the endoplasmic reticulum and in the channels confluent with the infoldings of the plasma membrane of perivascular microglial cells. The amyloid deposition in the wall of the vessel causes degeneration of endothelial cells and the reduction of, and in some vessels obliteration of, the vessel lumen. In areas affected by amyloid angiopathy, extensive degeneration both of the neuropil and of neurons was observed. These changes were accompanied by astrogliosis. This study demonstrates similarities in amyloid formation in amyloid angiopathy and in beta-amyloid plaques in the neuropil and suggests that cells of the mononuclear phagocyte system of the brain (perivascular cells and perivascular microglia) are engaged in amyloid fibril formation.

Interaction of a Pyelonephritogenic Escherichia Coli Strain with the Tissue Components of the Mouse Urinary Tract

Immediately following the introduction of cells of a pyelonephritogenic strain of Escherichia coli (expressing both GS and MS adhesins) into the mouse bladder, these cells were found to be randomly distributed on the mucosal surfaces of both the bladder and the kidney. After 24hr. these adherent bacterial cells had proliferated to form nonrandomly distributed adherent microcolonies on both mucosal surfaces and large masses within the renal ducts. Large amounts of amorphous material, which we presume to be of both host and bacterial origin, was associated with the bacterial microcolonies on the infected tissues. The removal of urinary slime and tissue coat material by acid pretreatment increased both the degree and the apparent avidity of bacterial adhesion to the bladder mucosa. The adherent bacteria on the bladder mucosa were radically elongated, while those on the kidney mucosa usually retained their short rod-like morphological characteristics. These data suggest that pyelonephritogenic bacteria adhere to mucosal surfaces in both the bladder and kidney, and proliferate to form adherent microcolonies within which bacteria are associated with large amounts of amorphous extracellular material.

Amorphous Material and Aluminum Interlayers in Quebec Spodosols

AbstractClay fraction from spodic B horizons of Appalachian and Laurentian soils was recovered after organic matter and sesquioxides removal. Sodium citrate and sodium hydroxide further extracted various amounts of Al, Si, and Fe. Samples from the Appalachian sites released &lt; 5% Al2O3 + SiO2 and &lt; 1% Fe2O3. There were only small differences between the amounts of material extracted by both reagents. After citrate treatment, a moderate increase of CEC was observed and related to Al interlayer removal, while after NaOH + citrate treatment the CEC decreased slightly because of amorphous material removal. Samples from the Laurentian sites released from 9.3 to 30.0% Al2O3 + SiO2 in NaOH and subsequently 1.6 to 6.0% Fe2O3 in Na‐citrate. The presence of large amounts of amorphous material prevented the identification of clay minerals by X‐ray diffraction analysis, and its removal caused a strong decrease of the CEC. Citrate alone extracted this poorly crystalline material at a slower rate and for these samples, this was followed by a decrease of the cation exchange capacity.

An ultrastructural and histochemical study of a naturally occurring salivary mucocele in a cat

A mucocele was found in a cat and extended from the sublingual fold to the level of the thyroid cartilage. An interlobular duct of the sublingual gland communicated with the mucocele. The cavity of the mucocele was limited by a capsule containing a large amount of amorphous material. Macrophages lining the cavity contained strong lysosomal enzymic activity and vacuoles containing mucus-like material. Appearances suggestive of fusion of lysosome-like bodies and these vacuoles were seen.

Chemical and Mineralogical Studies on Slick Spot Soils in Idaho

AbstractA study of a slick spot and associated soils showed the slick spot soil to be characterized by high salts and exchangeable Na throughout the profile whereas the high concentration of salts and exchangeable Na occurred at progressively greater depths in the profile in proceeding from the slick spot into the adjacent associated soils.They clay‐size minerals found in both the slick spot soils and the associated soils were illite, montmorillonite, kaolinite, quartz and feldspars. Montmorillonite maxima occurred at progressively lower depths in the profile in proceeding from the slick spot into the associated soils.Partial dissolution studies on the clay‐size fraction of the soils showed large amounts of amorphous material with the greatest amount being present in the slick spot soil. It was postulated that this amorphous material together with the high Na content contributed to the impermeability of these soils.