Expulsion Of Material Research Articles

Geochemical Evidence for Provenance, Tectonic Settings and Presence of Gas Hydrate in Mud Volcano Sediments of Andaman Islands

Abstract Mud volcanoes are one of the land / seafloor expressions of the expulsion of argillaceous material from deeper areas, generated by an extrusion activity involving the transfer of sediments, liquids and gas from subsurface to the land / seafloor. Eruption of mud volcano has been recorded historically in 1843, 1879, 1907, 1983, 2003, and 2004 in Bara tang in Middle and Diglipur in North Andaman Islands. Exceeding of threshold pressure of pressured gas and/ or liquid breaks upward through the overlying sediment frequently following existing zone of weakness and flow out sub aerially or subaqueous condition. Venting structure of mud volcanoes are the most important natural seepage features with fluid, gases and sediments from the earth’s surface. Most of the terrestrial mud volcanoes are located in convergent plate margin with thick sedimentary sequences as seen in Alpine-Himalayan, Caribbean and Pacific organic belts. The occurrence of mud volcanoes is controlled by several factors, such as tectonic activity, sedimentary loading due to rapid sedimentation and the existence huge thickness of fine-grained sediments and continuous hydrocarbon accumulation. Tectonic setting discrimination diagrams based on major, minor and trace elements suggest a shale provenance in an oceanic island arc. The correlation of K2O with other elements, abundance of Al2O3, Ba, Th suggest that these elements are primarily controlled by the dominant clay minerals. The compositional immaturity of the analyzed mud volcano sediments is typical of sub ducted-related environments, and their SiO2/Al2O3 and K2O/Na2O ratios reflect their oceanic island arc settings.

Histological and Histochemical Observations on Mast Cell and Glands in Chronic Tonsillitis.

Mast cell take active part in immune system of body, clinical manifestations are closely related to hypersensitivity. Reactions and potent biological mediators released by these cells are responsible for different clinical manifestation like allergic reaction. Frequent and important sites of these allergic reactions occur in-upper aero digestive tract, nasal, pharyngeal and respiratory allergies. The study aims to demonstrate different types of heparin in mast cells having role in tonsillitis. Present work is to study distribution and histochemical nature of mast cells in human palatine tonsil in patients suffering from chronic tonsillitis. 20 cases were studied during the study. Diagnosis was done on clinical criteria-Anterior pillar flushing. Expulsion of cheesy material from the tonsillar crypts on pressing with tongue depressor. Palpable jugulodigastric group of lymph nodes. Dissected Tonsillar material fixed into fixative-staining done. For qualitative histological observation Harris Haemotoxylene with eosin used as counter stain. Normal Histological study of mast cell like size, shape, granules were done. Distribution of mast cells in different parts of Tonsillar Tissue was observed. Histochemical study of mast cells to determine nature of reactive substance was done. Tonsil contains mucous glands, no granular tissue in present study of chronic inflammatory reactions feasible in form of fibrosis, lymphatic infiltration in epithelium. Morphology of mast cells with toluidine blue at pH 2 and 4.4 gave better picture. Mast cells had varied shape and size in different places and points of same field of focus, oval, elongated, fusiform, pleomorphic in shape. Nucleus is central ill-defined masked by granules. Cytoplasm contains mast cell granules that stained blue with Alcian blue stain, purple to bluish purple with toluidine blue. Distribution of mast cells in present study: Mast cells were found at all places mostly concentrated at capsules. Lamina propria-1-2/hpf, capsule-4-5/hpf, connective tissue septa-1-2/hpf. Histochemical Feature- In present study, histochemical study remained confined to connective tissue septa of mast cells and biochemical nature of Heparin contained in it. In present work, the identification of mast cells is based on metachromatic reactions of its granules with acidified toluidine blue at pH 2 and buffered toluidine blue at pH 4.4 to identify mast cell granules containing higher and lower sulphates of heparin.

Extracellular traps and macrophages: new roles for the versatile phagocyte.

MΦ are multipurpose phagocytes with a large repertoire of well-characterized abilities and functions, including regulation of inflammation, wound healing, maintenance of tissue homeostasis, as well as serving as an integral component of the innate-immune defense against microbial pathogens. Working along with neutrophils and dendritic cells, the other myeloid-derived professional phagocytes, MΦ are one of the key effector cells initiating and directing the host reaction to pathogenic organisms and resolving subsequent responses once the threat has been cleared. ETs are a relatively novel strategy of host defense involving expulsion of nuclear material and embedded proteins from immune cells to immobilize and kill bacteria, fungi, and viruses. As research on ETs expands, it has begun to encompass many immune cell types in unexpected ways, including various types of MΦ, which are not only capable of generating METs in response to various stimuli, but recent preclinical data suggest that they are an important agent in clearing ETs and limiting ET-mediated inflammation and tissue damage. This review aims to summarize historical and recent findings of biologic research regarding ET formation and function and discuss the role of MΦ in ET physiology and associated pathologies.

NETs and CF Lung Disease: Current Status and Future Prospects.

Cystic Fibrosis (CF) is the most common fatal monogenic disease among Caucasians. While CF affects multiple organ systems, the principle morbidity arises from progressive destruction of lung architecture due to chronic bacterial infection and inflammation. It is characterized by an innate immune defect that results in colonization of the airways with bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa from an early age. Within the airway microenvironment the innate immune cells including epithelial cells, neutrophils, and macrophages have all been implicated in the host defense defect. The neutrophil, however, is the principal effector cell facilitating bacterial killing, but also participates in lung damage. This is evidenced by a disproportionately elevated neutrophil burden in the airways and increased neutrophil products capable of tissue degradation, such as neutrophil elastase. The CF airways also contain an abundance of nuclear material that may be originating from neutrophils. Neutrophil extracellular traps (NETs) are the product of a novel neutrophil death process that involves the expulsion of nuclear material embedded with histones, proteases, and antimicrobial proteins and peptides. NETs have been postulated to contribute to the bacterial killing capacity of neutrophils, however they also function as a source of proteases and other neutrophil products that may contribute to lung injury. Targeting nuclear material with inhaled DNase therapy improves lung function and reduces exacerbations in CF and some of these effects may be due to the degradation of NETs. We critically discuss the evidence for an antimicrobial function of NETs and their potential to cause lung damage and inflammation. We propose that CF animal models that recapitulate the human CF phenotype such as the CFTR−/− pig may be useful in further elucidating a role for NETs.

Process Window for Friction Stir Lap Welding of Aluminum Alloy 6061

Precipitation-hardenable 6xxx series aluminum alloys are incorporated in many structural components with due consideration of their good combination of properties including a relatively high strength, outstanding extrudability and excellent corrosion resistance. Accordingly, AA6061 has been identified as a very good candidate material for structural lightweighting of transportation vehicles. However, the weldability of aluminum alloy (AA) 6061 by means of conventional technologies such as GMAW and GTAW methods is limited by sensitivity to solidification cracking. In this respect, friction stir welding (FSW) presents a tremendous potential for assembly of aluminum structures for the transportation industry due to the low heat involved that can mitigate crack formation and, thus, translate into improved mechanical performance of the assembly. In this work, FSW of 3.18 mm thick AA6061-T6 sheets in the lap joint configuration was investigated. This configuration is considered to be more challenging for assembly by FSW than the butt joint type due to the orientation of the interface with respect to the welding tools and the necessity to break the oxide layer on two aluminium alloy planar surfaces. Weld trials were performed to examine the influence of the FSW tool geometry and process parameters on the welding defects, microstructure, hardness and bend performance. Unacceptable material expulsion and/or significant thinning in one of the two overlapped sheets were produced under most conditions. A set of FSW tool geometries leading to a viable process operational window under which the risk of defects could be mitigated and/or eliminated was identified in this study.

OC-042 Endoscopic Ultrasound Guided Fine Needle Aspiration of Pancreatic Mass Lesions can be Less Accurate with a Metallic Stent in Situ but should not Delay Treatment of Obstructive Jaundice

IntroductionEndoscopic ultrasound (EUS) examination and fine needle aspiration (FNA)of the pancreas is now a routine method of obtaining diagnositic tissue for suspected pancreatic mass lesions, however if a biliary self...

Sushruta in 600 B.C. introduced extraocular expulsion of lens material

It is generally accepted that Jacques Daviel introduced in the 18th century the extracapsular technique of extraction of the lens while the couching method of cataract operation had already been practiced since ancient times. Present study analyses the first known cataract surgery description in three translations into English from the original Sanskrit Sushruta textbook and all the available literature on the subject. We found evidences that some sort of extraocular expulsion of lens material through a limbal puncture (paracentesis) was described by the Indian surgeon. Nevertheless, this incision cannot be considered as a classic extracapsular procedure because it was not large enough to allow the extraction of the entire lens.

PMO-004 Do we need propofol sedation and a cytologist present during endoscopic ultrasound? Initial experience from a UK centre

IntroductionEndoscopic ultrasound (EUS) is a prolonged procedure using endoscopes nearly twice the diameter of a standard gastroscope and relies on a compliant still patient to obtain images and fine needle...

Comment on Dörr and Zulauf: Elevator tectonics and orogenic collapse of a Tibetan-style plateau in the European Variscides: the role of the Bohemian shear zone. Int J Earth Sci (Geol Rundsch) (2010) 99: 299–325

The present comment disproves the tectonic model of a late Devonian/early Carboniferous Tibetan-style collisional plateau in the Tepla-Barrandean (TB) part of the Bohemian Massif, which later collapsed by thermal weakening of the underlying crust. Contrary to this model, the TB neither reveals major crustal thickening nor uplift and erosion, and eastern continuations of the TB were, during the relevant time-span, areas of open marine sedimentation. Late Devonian/early Carboniferous marine sediments widespread also in the Armorican and Central Massifs of France testify to low topography in central parts of the Variscan orogen. Notional traces of a Permo-Carboniferous ice cap on the French Massif Central do not support the plateau model, because they are questionable and much younger than the inferred plateau stage of the TB. The relative uplift of high-grade metamorphic rocks to the NW and the SE of the TB is not due to sinking of an elevated TB, but, instead, to the hydraulic and buoyant expulsion of HP material from the Saxo-Thuringian and Moldanubian subduction channels. The rise of lower-grade HT rocks along the southwestern margin of the Bohemian Massif was effected by late Carboniferous transpression. The high temperature and the resulting low viscosity of the rising materials were probably not caused by Variscan mantle delamination, but relate to lithospheric thinning and heating at the tip of the westward propagating Tethys Rift.

Hydrophilic Interfacing for Thermal Micro Assembly of Polymers (HITMAP)

This paper presents a simple approach to create microchannels in polydimethylsiloxane (PDMS) using basic hydrophobic–hydrophilic interactions of polymers. During polymerization, low molecular weight hydrophobic chains of PDMS expel hydrophilic moieties. This phenomenon has been used to create microchannels in PDMS. The process is simple, systematic, flexible in design, easy to implement, rapid, inexpensive and does not require lithography. Fabrication of microchannels in PDMS can be carried out using bench-top tools without the aid of any special facilities or equipment. With directed thermal polymerization over the hot plate, the expulsion of hydrophilic materials creates microchannels along the path traveled by particles. The approach is sensitive to the polymer viscosity, temperature profile and the surface chemistry of the particles. This work can have important implications in reducing the cost and time for prototyping polymer based applications in separation science, cell behavior studies, catalytic membranes and hydrogen storage. The membranes are characterized for electrical continuity and charge effects on conductivity.

A simple methodology for predicting laser-weld properties from material and laser parameters

In laser material processing, understanding the laser interaction and the effect of processing parameters on this interaction is fundamental to any process if the system is to be optimized. Expanding this to different materials or other laser systems with different beam characteristics makes this interaction more complex and difficult to resolve. This work presents a relatively simple physical model to understand these interactions in terms of mean surface enthalpy values derived from both material parameters and laser parameters. From these fundamental properties the melt depth and width for any material can be predicted using a simple theory. By considering the mean enthalpy of the surface, the transition from conduction limited melting to keyholing can also be accurately predicted. The theory is compared to experimental results and the predicted and observed data are shown to correspond well for these experimental results as well as for published results for stainless steel and for a range of metals. The results suggest that it is important to keep the Fourier number of the weld much smaller than one to make it efficient. It is also discussed that the surface enthalpy could be used to prodict other effects in the weld such as porosity and material expulsion.

Synthesis of TiO2 nanoscale rods with MHz femtosecond laser irradiation of single crystal surface and characterisation

Growth of nanoscale rods on single crystal rutile TiO2 surface irradiated by MHz pulse repetition rate femtosecond laser in nitrogen environment without a catalyst or template is reported. The rods are of 100 nm in width to 1 micron length. Microraman analysis of the laser irradiated surface shows only a decrease in the intensity of active modes as compared to untreated surface. The growth of TiO2 nanorods can be explained by a method combining nanoparticles formation due to expulsion of molten material from laser irradiated spot and their subsequent growth by vapor-liquid-solid process.

Characterization of MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces

In this study, MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces under ambient condition were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The radiation fluence used was 0.5 J/cm2 at a pulse repetition rate of 25 MHz with 1 ms interaction time. SEM analysis of the irradiated surfaces showed self-assembled intermingled weblike nanofibrous structure in and around the laser-irradiated spots. Further TEM investigation on this nanostructure revealed that the nanofibrous structure is formed due to aggregation of Au-Si/Si nanoparticles. The XRD peaks at 32.2°, 39.7°, and 62.5° were identified as (200), (211), and (321) reflections, respectively, corresponding to gold silicide. In addition, the observed chemical shift of Au 4f and Si 2p lines in XPS spectrum of the irradiated surface illustrated the presence of gold silicide at the irradiated surface. The generation of Si/Au-Si alloy fibrous nanoparticles aggregate is explained by the nucleation and subsequent condensation of vapor in the plasma plume during irradiation and expulsion of molten material due to high plasma pressure.

The effectiveness of stilbenes in resistant Vitaceae: Ultrastructural and biochemical events during Plasmopara viticola infection process

Leaves of different Vitis vinifera L. cultivars, susceptible or resistant to downy mildew, Chasselas, Solaris, IRAC 2091 (cvs. Gamaret x Bronner) and Muscadinia rotundifolia were inoculated with Plasmopara viticola. Samples were then examined by scanning and transmission electron microscopy, by light microscopy and for their ability to synthesise stilbenes. These phytoalexins were strictly analysed at infection sites. In the susceptible Chasselas, P. viticola colonises, at 72h post-infection (hpi), all of the spongy mesophyll with functional haustoria and produces mainly the non toxic piceide. No necrotic zone was observed on Chasselas leaves. The ultrastructural response to downy mildew infection is different in each of the other three resistant grape cultivars. In Solaris, where leaf necrosis are rapidly induced, the infection is restricted to the upper part of the loose spongy mesophyll, and associated with a rapid cell wall disruption and the dispersion of cytoplasmic content along with the production of viniferins. In IRAC 2091, leaf necrosis are quite similar to those observed on Solaris but the infected plant cell, as well as the haustoria, show high electron dense cellular particles without any recognisable organelles, probably related to the effect of the toxic compound pterostilbene, which is synthesised in this grape cultivar. In M. rotundifolia leaf necrosis are much more scarce and smaller than in other cultivars, but pathogen and plant cells are both strongly affected, with concomitant expulsion of cytoplasmic materials through the stomata after P. viticola penetration. In this cultivar, the concentration of all identified stilbenes exceeds 1×10³ μmol mg(-1) FW. The critical role of stilbenes in the resistance of Vitis spp. is discussed.

Selective laser melting of Inconel 625 using pulse shaping

PurposeThe purpose of this paper is to investigate the selective laser melting (SLM) of Inconel 625 using pulse shape control to vary the energy distribution within a single laser pulse. It aims to discuss the effectiveness of pulse shaping, including potential benefits for use within SLM.Design/methodology/approachLaser parameters were varied in order to identify optimal parameters that produced thin wall parts with a low surface roughness without the use of pulse shape control. Pulse shape control was then employed to provide gradual heating or a prolonged cooling effect with a variety of peak power/pulse energy combinations. Properties of pulse shaped and nonpulse shaped parts were compared, with particular attention focused on part surface roughness and width.FindingsHigh peak powers tended to reduce top surface roughness and reduce side roughness as recoil pressures flatten out the melt pool and inhibit melt pool instabilities from developing. Ramp up energy distribution can reduce the maximum peak power required to melt material and reduce material spatter generation during processing due to a localized preheating effect. Ramp down energy distribution prolonged melt pool solidification allowing more time for molten material to redistribute, subsequently reducing the top surface roughness of parts. However, larger melt pools and longer solidification times increased the side roughness of parts due to a possible lateral expulsion of material from the melt pool.Originality/valueThis paper is the first of its kind to employ laser pulse shape control during SLM to process material from powder bed. It is a useful aid in unveiling relationships between laser energy distribution and the formation of parts.

THE FORMATION OF GRAPHITE WHISKERS IN THE PRIMITIVE SOLAR NEBULA

It has been suggested that carbonaceous grains are efficiently destroyed in the interstellar medium and must either reform in situ at very low pressures and temperatures or in an alternative environment more conducive to grain growth. Graphite whiskers have been discovered associated with high-temperature phases in meteorites such as calcium aluminum inclusions and chondrules, and it has been suggested that the expulsion of such material from proto stellar nebulae could significantly affect the optical properties of the average interstellar grain population. We have experimentally studied the potential for Fischer-Tropsch and Haber-Bosch type reactions to produce organic materials in protostellar systems from the abundant H2, CO, and N2 reacting on the surfaces of available silicate grains. When graphite grains are repeatedly exposed to H2, CO, and N2 at 875 K abundant graphite whiskers are observed to form on or from the surfaces of the graphite grains. In a dense, turbulent nebula, such extended whiskers are very likely to be broken off, and fragments could be ejected either in polar jets or by photon pressure after transport to the outer reaches of the nebula.

Phenylalanine-Rich Peptides Potently Bind ESAT6, a Virulence Determinant of Mycobacterium tuberculosis, and Concurrently Affect the Pathogen's Growth

BackgroundThe secretory proteins of Mycobacterium tuberculosis (M. tuberculosis) have been known to be involved in the virulence, pathogenesis as well as proliferation of the pathogen. Among this set, many proteins have been hypothesized to play a critical role at the genesis of the onset of infection, the primary site of which is invariably the human lung.Methodology/Principal FindingsDuring our efforts to isolate potential binding partners of key secretory proteins of M. tuberculosis from a human lung protein library, we isolated peptides that strongly bound the virulence determinant protein Esat6. All peptides were less than fifty amino acids in length and the binding was confirmed by in vivo as well as in vitro studies. Curiously, we found all three binders to be unusually rich in phenylalanine, with one of the three peptides a short fragment of the human cytochrome c oxidase-3 (Cox-3). The most accessible of the three binders, named Hcl1, was shown also to bind to the Mycobacterium smegmatis (M. smegmatis) Esat6 homologue. Expression of hcl1 in M. tuberculosis H37Rv led to considerable reduction in growth. Microarray analysis showed that Hcl1 affects a host of key cellular pathways in M. tuberculosis. In a macrophage infection model, the sets expressing hcl1 were shown to clear off M. tuberculosis in much greater numbers than those infected macrophages wherein the M. tuberculosis was not expressing the peptide. Transmission electron microscopy studies of hcl1 expressing M. tuberculosis showed prominent expulsion of cellular material into the matrix, hinting at cell wall damage.Conclusions/SignificanceWhile the debilitating effects of Hcl1 on M. tuberculosis are unrelated and not because of the peptide's binding to Esat6–as the latter is not an essential protein of M. tuberculosis–nonetheless, further studies with this peptide, as well as a closer inspection of the microarray data may shed important light on the suitability of such small phenylalanine-rich peptides as potential drug-like molecules against this pathogen.

Parameter influence on friction welding of dissimilar surface-carburized/volume-hardened alloyed steels

The influence of the main friction-welding parameters, such as the axial pressure, the friction stroke and the upsetting temperature on the compositional, structural and hardness gradient is shown for dissimilar joints made out of carburized and volume-hardened steels. The expulsion of the carbon-enriched layer in the burr as a qualitative factor is analyzed. Low axial pressure and long friction time favours to the presence of a carburized layer in the joint plane. A high axial pressure, as well as an increase in the friction stroke favours the expulsion of the carbon-enriched layer from the joining area into the burr. A high upsetting pressure leads to an increase of the plasticized material expulsion in the burr.

New ablation experiment aimed at metal expulsion at the hydrodynamic regime

The effects of nanosecond visible laser on metallic materials have been studied experimentally. High laser energies (>10 13 W/cm 2) created a hydrodynamic regime, where the ablation pressure and the ensuing shock wave are the main mechanisms for material expulsion. Plasma shielding caused a constant material removal despite the increase of energy, while the increase of number of pulses resulted in an almost linear increase of the crater volume, despite the lower depths reached with every subsequent pulse. Our results show that there is a correlation between ablation efficiency and material properties, namely ablation efficiency decreases with melting temperature and bulk modulus.

MOLECULAR GAS AND THE HOST-GALAXY SYSTEM OF THEz∼ 0.3 QSO PG 1700+518

The detection of CO(1→0) emission in the massive (i.e., MH ~ –26.13 mag), z ~ 0.3 host-galaxy system of the broad absorption line quasi-stellar object (QSO) PG1700+518 is reported. The host system has a CO luminosity of L'_CO ~ 1.4 × 10^(10) K km s^(–1) pc^2, and thus a star-forming molecular gas mass of M(H_2) ~ 6 × 10^(10) M_☉ (adopting an α = 4 M_☉[K km s^(–1) pc^2]^(–1)), making it one of the most molecular gas-rich Palomar-Green QSO hosts observed to date. New Hubble Space Telescope WFPC2 direct and NICMOS coronagraphic images show the highest resolution view yet of the host and companion. The new NICMOS image reveals the underlying, apparently tidally disrupted structure seen previously from high-resolution ground-based optical imaging. Light from the host galaxy is overwhelmed by the central point source in the WFPC2 images. The companion galaxy is well resolved in both data sets, and the WFPC2 provides for the first time a clear picture of the optically visible ring structure. The CO redshift is within the range of redshifts derived from optical QSO emission lines, thus the observed CO is associated with the QSO host. However, it cannot be ruled out that the companion has at least ~10^(10) M_☉ of molecular gas. Finally, if the far-infrared luminosity, which is 1/5 of the bolometric luminosity, is the luminosity of the starburst population, the star formation rate is estimated to be ~210 M_☉ yr^(–1). There is thus sufficient molecular gas in the QSO host galaxy to fuel both star formation and QSO activity for another ~10^8 yr. We speculate that we may be witnessing the fueling event in progress that resulted from a collision between the QSO host and the companion galaxy, and that there is an accompanying expulsion of material along our line of sight in the form of broad absorption line gas.