147 research outputs found

    Design and Fabrication of Industrially Scalable low cost Liquid Impregnated Surfaces with extreme hydratephobic properties

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    The design and fabrication of extremely hydrate phobic Liquid Impregnated Surfaces (sometimes abbreviated as LIS) based on industrial material Aluminium Al6061 and industrially scalable low-cost method were carried out. A simple hydrochloric acid-based etching method and boiling water treatment were used to generate micro and nanoscale nanopetal roughness features respectably. A theoretical analysis was performed to find out the relationship between the interfacial interactions and surface roughness features to predict the stability of lubricant oil of LIS under water and oil environment. LIS with appropriate surface chemistry and textures were fabricated to experimentally validate the theoretical analysis on lubricant stability. Subsequent experimental measurements of hydrate adhesion were performed on LIS with stable lubricant layers, using a custom-made experimental setup and cantilever-based method. Cyclopentane hydrate, mimics gas hydrate forming mechanism at atmospheric pressure, and is used for the hydrate adhesion measurements. Extreme reduction of hydrate adhesion with more than four orders of magnitude was observed on LIS compared to control smooth aluminium surface

    Drone-Truck Cooperated Delivery under Time Varying Dynamics

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    Rapid technological developments in autonomous unmanned aerial vehicles (or drones) could soon lead to their large-scale implementation in the last-mile delivery of products. However, drones have a number of problems such as limited energy budget, limited carrying capacity, etc. On the other hand, trucks have a larger carrying capacity, but they cannot reach all the places easily. Intriguingly, last-mile delivery cooperation between drones and trucks can synergistically improve delivery efficiency. In this paper, we present a drone-truck co-operated delivery framework under time-varying dynamics. Our framework minimizes the total delivery time while considering low energy consumption as the secondary objective. The empirical results support our claim and show that our algorithm can help to complete the deliveries time efficiently and saves energy

    A flow cytometry based method for studying embryogenesis and immune reactivity to embryogenic stages in filarial parasites

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    BACKGROUND: In the absence of intermediate animal hosts, the process of embryogenesis leading to fecundity of adult female filarial worms is very critical for persistence of these obligate parasites in human communities. Embryogenesis in adult female filarial parasites involves fertilization of eggs or oocytes by sperms and their subsequent development into motile microfilariae inside the uterine cavity of worms. Development of assays for monitoring embryogenesis in adult female worms is a critical requirement in filariasis research – filarial worms are known to harbour endosymbionts such as Wolbachia which play a significant role in fecundity. Tetracycline or doxycycline treatment of the infected hosts effectively eliminates the endosymbionts resulting in inhibition of embryogenesis in female worms. Currently, inhibition of embryogenesis in adult filarial worms can be monitored only by microscopic examination of in vitro harvested intrauterine stages. METHODS: Adult female filarial worms of bovine filarial parasites, Setaria digitata were collected from the peritoneum of infected animals and intrauterine stages were harvested in culture medium and were analyzed for forward and side scatter by flowcytometry using a BD FACS Calibur. Different populations were gated, sorted and identified by phase microscopy. Binding of biotinylated lectins to intra uterine stages was monitored using FITC labeled Avidin and monitored by flow cytometry of gated populations. Similarly, binding of antibodies in human filarial sera to intrauterine stages was monitored using FITC labeled anti-human immunoglobulins. RESULTS: The forward and side scatter for intrauterine stages delineated 3 distinct populations labeled as R1, R2 and R3. The three populations were sorted and identified to be a) fully stretched microfilariae, b) early and c) late developmental stages of eggs respectively. Lectins such as Wheat Germ agglutinin or Concanavalin-A were found to bind strongly to egg stages and less prominently to intra-uterine microfilariae. Similarly the binding of antibodies in filarial sera to the three intra-uterine stages could also be precisely quantified. CONCLUSION: The manuscript reports a novel flow cytometry based method to monitor progression of embryogenesis in adult filarial worms. Apart from relative quantification of different intra uterine developmental stages, the assay allows quantitative binding of lectins and antibodies to each of the intrauterine stages. It may now be possible to quantify levels of antibodies in infected and immune hosts to monitor anti-fecundity immunity in filariasis – the assay can thus be used as a powerful tool for drug development and in immunological studies in human and experimental filariasis

    A Parallel Algorithm Template for Updating Single-Source Shortest Paths in Large-Scale Dynamic Networks

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    The Single Source Shortest Path (SSSP) problem is a classic graph theory problem that arises frequently in various practical scenarios; hence, many parallel algorithms have been developed to solve it. However, these algorithms operate on static graphs, whereas many real-world problems are best modeled as dynamic networks, where the structure of the network changes with time. This gap between the dynamic graph modeling and the assumed static graph model in the conventional SSSP algorithms motivates this work. We present a novel parallel algorithmic framework for updating the SSSP in large-scale dynamic networks and implement it on the shared-memory and GPU platforms. The basic idea is to identify the portion of the network affected by the changes and update the information in a rooted tree data structure that stores the edges of the network that are most relevant to the analysis. Extensive experimental evaluations on real-world and synthetic networks demonstrate that our proposed parallel updating algorithm is scalable and, in most cases, requires significantly less execution time than the state-of-the-art recomputing-from-scratch algorithms

    A two years study of histopathological spectrum of skin adnexal tumors in a tertiary care centre of Southern Assam, India

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    Background: Skin adnexal tumors (SAT) encompass a wide spectrum of benign and malignant tumors that differentiate toward one or more adnexal structures found in normal skin. Overall incidence of SATs is low yet they can be challenging to diagnose. Our study aims at analysis of histopathological spectrum of various SATs according to age, sex and anatomic locations along with histopathological features.Methods: It was a retrospective cross-sectional study conducted over a period of 2 years from June 2017 to May 2019. All cases were retrieved from department registries and analyzed.Results: Out of the total 4013 biopsies, 25 cases were diagnosed as SATs comprising 44% of tumors with eccrine sweat gland differentiation followed by tumors showing hair follicle differentiation (32%), sebaceous differentiation (16%) and apocrine gland differentiation (8%). The age ranged from 4 years to 68 years and male: female ratio was 1:1.5. Most of the tumors were benign (84%) while only 16% were malignant. Pilomatricoma (19%) was the most common benign tumor while sebaceous carcinoma (75%) was the most common malignant tumor.Conclusions: Skin adnexal tumors are relatively rare neoplasm. Malignant cases are less common than benign ones. Histopathology is quite essential for diagnostic point of view

    Extended Self-similarity in Kinetic Surface Roughening

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    We show from numerical simulations that a limited mobility solid-on-solid model of kinetically rough surface growth exhibits extended self-similarity analogous to that found in fluid turbulence. The range over which scale-independent power-law behavior is observed is significantly enhanced if two correlation functions of different order, such as those representing two different moments of the difference in height between two points, are plotted against each other. This behavior, found in both one and two dimensions, suggests that the `relative' exponents may be more fundamental than the `absolute' ones.Comment: 4 pages, 4 postscript figures included (some changes made according to referees' comments. accepted for publication in PRE Rapid Communication

    Lamin A Δexon9 mutation leads to telomere and chromatin defects but not genomic instability

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    Over 300 mutations in the LMNA gene, encoding A-type lamins, are associated with 15 human degenerative disorders and premature aging syndromes. Although genomic instability seems to contribute to the pathophysiology of some laminopathies, there is limited information about what mutations cause genomic instability and by which molecular mechanisms. Mouse embryonic fibroblasts depleted of A-type lamins or expressing mutants lacking exons 8–11 (Lmna(Δ8–11/Δ8–11)) exhibit alterations in telomere biology and DNA repair caused by cathepsin L-mediated degradation of 53BP1 and reduced expression of BRCA1 and RAD51. Thus, a region encompassing exons 8–11 seems essential for genome integrity. Given that deletion of lamin A exon 9 in the mouse (Lmna(Δ9/Δ9)) results in a progeria phenotype, we tested if this domain is important for genome integrity. Lmna(Δ9/Δ9) MEFs exhibit telomere shortening and heterochromatin alterations but do not activate cathepsin L-mediated degradation of 53BP1 and maintain expression of BRCA1 and RAD51. Accordingly, Lmna(Δ9/Δ9) MEFs do not present genomic instability, and expression of mutant lamin A Δexon9 in lamin-depleted cells restores DNA repair factors levels and partially rescues nuclear abnormalities. These data reveal that the domain encoded by exon 9 is important to maintain telomere homeostasis and heterochromatin structure but does not play a role in DNA repair, thus pointing to other exons in the lamin A tail as responsible for the genomic instability phenotype in Lmna(Δ8–11/Δ8–11) mice. Our study also suggests that the levels of DNA repair factors 53BP1, BRCA1 and RAD51 could potentially serve as biomarkers to identify laminopathies that present with genomic instability
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