135 research outputs found
Enhanced ionic conductivity of co-doped ceria-carbonate nano composite electrolyte material for LT-SOFCs
No full textMatrix Metalloproteinase Expression Varies Throughout Development and During the Innate Immune Response of Tobacco Hornworm. Manduca sexta
Full text linkMatrix metalloproteinases (MI'v1Ps) are a family of conserved, proteolytic enzymes.
MMPs can degrade most extracellular matrix proteins. As such, they are key enzymes in
tissue remodeling processes. such as molting and metamorphosis in insects. The presence
of MMP in tracheae of 4th and 5th instar Manduca scxra (M sexta) larvae was investigated
using zymograms and Western blots, and the expression was found to decrease at the end
of the instar. Failure to completely inhibit gelatinolytic activity in a zymogram indicates
the existence of various other proteases that arc involved in the molting process. However,
delay in the appearance of the dorsal blood vessel along with a reduction in the body mass
upon inhibition of MMP supports our hypothesis that MMPs are required for molting.
MMPs are also known to be up-regulated in many disease states, where they may
cause tissue damage. Their presence may be beneficial, as their inhibition may result in
worsening of symptoms or increased mortality. We tested the hypothesis that MMPs play
a role in innate immunity in the tobacco hornworm caterpillar. Jf. sex/a. Larvae infected
with E. coli DH5a had significantly more circulating hemocytes (insect blood cells) when
compared to the larvae v,:hich received an MMP inhibitor. suggesting that MMPs may be
important for hernocyte recruitment from the hematopoietic organs such as the lymph
gland and hematopoictic cells present near the v.'ing imaginal discs. The expression of
MMP was increased by 50% in larvae that had been infected with E. coli DH5a.
However, this response was abrogated upon inhibition of MMPs. reducing expression tocontrol levels. The majority of the circulating hemocytes were granulocytes. a cell type
that phagocytoses foreign bodies. including pathogens. We used flow cytometry to assess
phagocytic ability. Hemocytes in the presence of the MMP inhibitor were less abk to
phagocytose sephadex beads. supporting the hypothesis that this MMP contributes to the
cellular innate immune response.
Our results suggest that MMP expression is high at the beginning of the in star
while it reduces as the caterpillar reaches molting. during which other proteases like
chitinases and molting fluid proteinases play a more prominent role. Our results also
suggest that M. sex/a larvae have a reduced immunity to bacterial infections when MMPs
are inhibited. Collectively, inhibition of MMPs during the molting process indicates that
the larvae. by down regulating the expression of MMPs. prevent the elicitation of immune
responses that is generally seen during the larval pupal metamorphosis
Conceptual Design of High Temperature Superconducting Toroidal Field Coils for Future Fusion Power Plants
Full text linkAus der langjährigen Forschung im Bereich der magnetischen Eingrenzung sind Stellaratoren und Tokamaks entstanden, die starken und ungleichmäßigen Magnetfelder zum Einfangen der Plasmapartikel nutzen und es ihnen ermöglichen, sich frei auf bestimmten Wegen zu bewegen. Die Tokamaks haben durch ein einfacheres Spulendesign, verschachtelte magnetische Oberflächen und die Fähigkeit, mit positiver magnetischer Scherung zu arbeiten, an Bedeutung gewonnen. Derzeit plant die Europäische Union (EU), ihre Studien über Tokamak auf Demonstrationskraftwerke (EU-DEMO) auszudehnen, der Strom erzeugen können. Ziel dieser Studie ist es, ein Konzept für die Ringkernfeldspule (TF-Spule) für zukünftige Kraftwerke mit dem Systemcode PROCESS zu entwickeln. Ziel dieser Studie ist es, ein Konzept für die Toroidalfeldspule (TF-Spule) für zukünftige Kraftwerke mit dem Systemcode PROCESS zu entwickeln.
Der PROZESS-Code gibt bestimmte Informationen wie die ungefähre Form der TF-Spule, die Fläche des Wickelpakets, das Magnetfeld an der Plasmaachse. Ausgehend vom Eingang wird das Wickelpaket der TF-Spule entworfen. Zum Beispiel, wenn die Pancake-Wicklung gegenüber der Lagen-Wicklung bevorzugt wird. Zum Beispiel, wenn die Pancake-Wicklung gegenüber der Lagen-Wicklung bevorzugt wird. Die erste Lage, die der Plasmawärme zugewandt ist, wird angesammelt, da sie sich im Hochfeldbereich befindet, wodurch der Magnet mit einer geringeren Betriebsmarge arbeitet. Der Leiter der Pancake-Wicklung ist jedoch in Umfangsrichtung und nicht entlang der Achse eines Magneten gewickelt und jedes Modul ist separat gewickelt und elektrisch in Reihe geschaltet. Der wesentliche Vorteil bei diesem Verfahren ist, dass die Temperatur im Hochfeldbereich am niedrigsten ist, da sich der Heliumeinlass im Hochfeldbereich des Wickelpakets und der Auslass im Niederfeldbereich befindet. Das Wicklungspaket mit der elektrischen Schaltung ist in Reihe geschaltet und die hydraulische Schaltung ist parallel geschaltet.
Aus dem PROZESS-Code wird überprüft, ob das Magnetfeld an der Plasmaachse gleich dem erforderlichen Magnetfeld ist. Das Spitzenmagnetfeld wird auch zur Bestimmung des Arbeitspunktes des Leiters berechnet. Die 3D Elektromagnetische Simulation wird mit dem Präprozessor TOKEF und dem Code EFFI durchgeführt. Codes zur Magnetfeldberechnung einer allgemeinen dreidimensionalen Stromverteilung, die Formulierungen verwenden, die auf einer fadenförmigen Annäherung und der endlichen Leitergröße basieren. Diese Codes werden durch eine Reihe von verteilten Filamenten unter Verwendung der EFFI-Formel, die aus dem Bio-Savart Gesetz für die Volumenstromverteilung abgeleitet wurde, approximiert.
Die Statik der TF-Spule bestimmt die Spannungen im Spulengehäuse und im Wickelpaket. Der Bereich mit den höchsten Spannungen liegt in der Mittelebene des inneren Schenkels, was durch eine ähnliche Analyse mit dem Spulenmagnetsystem JT-60SA TF bestätigt wird. In der EU DEMO führt die TF-Spule hohe Ströme (in MA) und erzeugt hohe Felder. Die TF-Spule ist daher hohen magnetischen Drücken und Kräften ausgesetzt. Um die Spannungen im Wickelpaket und am Gehäuse zu untersuchen, werden in COMSOL und ANSYS verschiedene Methoden zur Analyse der Spannungen am Gehäuse, des Lösens des Wickelpakets und der Spannungen in Isolationsbauteilen betrachtet.
Ein wichtiger Fehler, der bei der Konstruktion supraleitender Magnete zu berücksichtigen ist, ist der Übergang von der supraleitenden zur normal leitenden Phase, dem sogenannten Quench. Da im normal leitenden Modus der elektrische Widerstand des Supraleitermaterials hoch ist, erzeugt die Einführung von Kupfer als elektrischer Ableiter für den Stromfluss eine Joule-Erwärmung. Der Magnet muss durch Anschluss eines externen Widerstandes parallel zum Magneten entladen werden, um einen übermäßigen Temperaturanstieg zu vermeiden. Die maximal zulässige adiabatische Hotspot-Temperatur, wie sie vom International Thermonuclear Experimental Reactor (ITER) festgelegt wurde, ist auf 150 K begrenzt, wobei alle Materialien im Leiter berücksichtigt werden, d.h. Supraleiter, Kupfer, Helium, Edelstahlmantel und Isolierung. Um die Quenchausbreitung zu simulieren, wird eine externe Heizung in den Supraleiter eingesetzt und überprüft, wie die Ausbreitung ist und welche maximale Temperatur sie während der Entladungszeit erreicht
Behaviour Of Cold-Formed Steel Open Sections
No full textThis paper presents the results of a parametric study conducted on cold-formed steel single angles and single channels, double angles and double channels both with and without lips with their ends hinged subjected to axial compression. The experiments were conducted till the specimen failed and observations were taken in the elastic and as well as in the plastic ranges of loading. The slenderness ratio of the angles tested were 15 and 30 and for channels the ratio ranged from 10 to 20. The flat width to thickness ratio of all the specimens were kept less than the limiting value. Ten different cross-sections were chosen and totally forty two experiments were conducted. In the present investigation attempt is made to study the effect of lip, thickness of the section, size of the section, material yield strength, section symmetricity on the ultimate load carrying capacity and the mode of failure. Load versus strain variation across the section, load versus axial shortening and lateral deflection behaviour is studied in this paper. The experimental ultimate loads were compared with the predicted loads prescribed by the Indian and American Standards. The failure modes of all the specimens were reported. Journal of Civil Engineering Research and Practice Vol. 2(2) 2005: 25-3
Understanding the role of interactions between host and Mycobacterium tuberculosis under hypoxic condition: an in silico approach
No full textMycobacterium tuberculosis infection in humans is often associated with extended period of latency. To adapt to the hostile hypoxic environment inside a macrophage, M. tuberculosis cells undergo several physiological and metabolic changes. Previous studies have mostly focused on inspecting individual facets of this complex process. In order to gain deeper insights into the infection process and to understand the coordination among different regulatory/ metabolic pathways in the pathogen, the current in silico study investigates three aspects, namely, (i) host-pathogen interactions (HPIs) between human and M. tuberculosis proteins, (ii) gene regulatory network pertaining to adaptation of M. tuberculosis to hypoxia and (iii) alterations in M. tuberculosis metabolism under hypoxic condition. Subsequently, cross-talks between these components have been probed to evaluate possible gene-regulatory events as well as HPIs which are likely to drive metabolic changes during pathogen's adaptation to the intra-host hypoxic environment.The newly identified HPIs suggest the pathogen's ability to subvert host mediated reactive oxygen intermediates/ reactive nitrogen intermediates (ROI/ RNI) stress as well as their potential role in modulating host cell cycle and cytoskeleton structure. The results also indicate a significantly pronounced effect of HPIs on hypoxic metabolism of M. tuberculosis. Findings from the current study underscore the necessity of investigating the infection process from a systems-level perspective incorporating different facets of intra-cellular survival of the pathogen.The comprehensive host-pathogen interaction network, a Boolean model of M. tuberculosis H37Rv (Mtb) hypoxic gene-regulation, as well as a genome scale metabolic model of Mtb, built for this study are expected to be useful resources for future studies on tuberculosis infection
Determination of material symmetries from ultrasonic velocity measurements: A genetic algorithm based blind inversion method
No full textThe determination of material symmetries and principle plane orientations of anisotropic plates, whose planes of symmetries are not known, are calculated using a Genetic Algorithm (GA) based blind inversion method. Ultrasonic phase velocity profiles were used as input data to the inversion. During each blind inversion, the material was initially assumed to be dependent on 21 elastic moduli (general anisotropy). A Genetic Algorithm based method was exploited to identify the “statistically significant” elastic moduli using the coefficient of variation (CV) to derive a reduced set of elastic moduli. The unknown material symmetry and the principle planes (angles between the geometrical coordinates and the material symmetry coordinates) were evaluated using the method proposed by Cowin and Mehrabadi [Cowin SC, Mehrabadi MM. On the identification of material symmetry for anisotropic elastic materials. Quart J Mech Appl Math 1987;40(4):451–76], Cowin [Cowin SC. Properties of the anisotropic elasticity tensor. Quart J Mech Appl Math 1989;42(2):249–66] and Sun [Sun M. Optical recovery of elastic properties for a general anisotropic material through ultrasonic measurements. M.S. thesis, The Graduate School, University of Maine, August 2002]. This procedure was verified using simulated ultrasonic velocity data sets on materials with transversely isotropic, orthotropic, monoclinic and triclinic symmetries. Experimental validation was also performed on a unidirectional graphite-epoxy [0]7s material, a quasi-isotropic graphite-epoxy [0/45/90/-45]7s fiber reinforced composite plate, and plate cut at 45° to the fibers from a unidirectional graphite-epoxy composite plate
Smoking related risk involved in individuals carrying genetic variants of CYP1A1 gene in head and neck cancer
No full textNot Available
No full textNot AvailableThe present study investigates genetic divergence among 84 fertility restorers and 32 cytoplasmic male sterile (CMS) lines of sunflower augmented from USDA, USA along with the popular Indian parental lines using simple sequence repeats (SSR). Thirty-nine polymorphic SSR primers produced 139 alleles with an average of 3.56 alleles per
locus. The polymorphic information content ranged from 0.23 to 0.69 with an average of 0.45. The average genetic distance was 0.45 and 0.42 for the R and CMS lines,
respectively. Dendrogram based on the dissimilarity coefficient matrix grouped the CMS and R lines into separate clusters except for Cluster A which consisted of all CMS
lines along with five R lines. Genetic distance matrix estimated from three sets of mitochondrial primers (BOX, ERIC and REP) grouped the 32 CMS lines into eight clusters. The results suggest the existence of considerable genetic diversity among the restorer and CMS lines of sunflower obtained from USDA, USA.Not Availabl
Chat with the ’For You’ Algorithm: An LLM-Enhanced Chatbot for Controlling Video Recommendation Flow
No full textThe rise of short-form video platforms like TikTok, driven by algorithmic recommendations, fosters immersive flow experiences. While users value personalization and engagement, they also seek greater agency over their For You recommendations. This paper designs, prototypes, and evaluates TKGPT, an LLM-enhanced conversational interface that helps users articulate their interests and understand recommendations. Through qualitative interviews and a user study, we examine how the TKGPT influences algorithmic folk theories and the sense of agency. Findings show that users primarily use TKGPT to seek relevant videos, explain preferences, and exert control over the algorithm. The resulting For You videos better reflect user interests, enhance the understanding of algorithm, improve content relevance, and reduce feelings of exploitation. Notably, users’ sense of agency is significantly associated with their improved understanding of how the algorithm works. We discuss the opportunities and challenges of using conversational user interfaces to enhance user control over video recommendations. © 2025 Copyright held by the owner/author(s)
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