Terms Of Cell Structure Research Articles

Thermal Insulating Rigid Polyurethane Foams with Bio-Polyol from Rapeseed Oil Modified by Phosphorus Additive and Reactive Flame Retardants.

In this article, rigid polyurethane foams obtained with the addition of a bio-polyol from rapeseed oil, were modified with the dimethyl propane phosphonate as additive flame retardant and two reactive flame retardants diethyl (hydroxymethyl)phosphonate and diethyl bis-(2-hydroxyethyl)-aminomethylphosphonate. The influence of used flame retardants on the foaming process and characteristic processing times of tested polyurethane systems were determined. The obtained foams were tested in terms of cell structure, physical and mechanical properties, as well as flammability. Modified foams had worse mechanical and thermal insulation properties, caused by lower cellular density and higher anisotropy coefficient in the cross-section parallel to the foam rise direction, compared to unmodified foam. However, the thermal conductivity of all tested foam materials was lower than 25.82 mW/m∙K. The applied modifiers effectively reduced the flammability of rigid polyurethane foams, among others, increasing the oxygen index above 21.4 vol.%, reducing the total heat released by about 41–51% and the rate of heat release by about 2–52%. A correlation between the limiting oxygen index values and both total heat released parameters from the pyrolysis combustion flow calorimetry and cone calorimetry was observed. The correlation was also visible between the value of the heat release capacity (HRC) parameter obtained from the pyrolysis combustion flow calorimetry and the maximum average rate of heat emission (MARHE) from the cone calorimeter test.

Current Research and Patents of Polymer Foaming

Background: Since the rapid development of polymers in the 1920’s, polymer products have become a necessary part of people's lives. Supercritical fluid technology was gradually introduced in this field. With the emergence of new technologies, methods, and equipment, the supercritical fluid technology has rapidly developed in the field of polymers and displayed a broad application perspective. Objective: The research progress of supercritical fluid-assisted polymer foaming, including equipment improvement, polymer composition ratio, and foaming process, and the influence of these processes on polymer foaming materials is reviewed here. Methods: Patents and research progress of supercritical fluid assisted polymer foams were reviewed. The advantages and disadvantages of various patents are analyzed in terms of cell structure, mechanical properties, surface quality, processing performance, and cost. Results: The foaming equipment and the manufacturing process of polymer foaming materials were retrospected, in order to improve the quality and application prospect of foaming composites. Conclusion: The preparation technology of supercritical fluid polymer foams has attracted wide attention. In recent years, patented technology has enabled us to use the supercritical fluid polymer foaming materials. There are some problems in the supercritical fluid foaming in terms of mechanical properties, cell structure, cell size, and processing technology, therefore, more equipment and patents are needed to solve these problems in the future.

Identification of Myocardial Telocytes and Bone Marrow Mesenchymal Stem Cells in Mice

Objectives: The aim of this study was to compare the morphology, immune phenotype, and cytokine profiles between myocardial telocytes (TCs) and bone marrow mesenchymal stem cells (MSCs), and explore the difference between those two types of interstitial cells. Methods: TCs and MSCs were cultured in vitro and cell morphology was observed with a light microscope. The expression levels of CD34, c-kit, and vimentin were detected by immunofluorescence, RT-qPCR, and Western blotting in both TCs and MSCs. The related supernatant was collected and total of 49 cytokine profiles were detected by RayBio Mice Cytokine Antibody Array. Significantly different cytokines were further confirmed by ELISA. Results: TCs have small cellular body and very long prolongations and they were CD34+/c-kit+/vimentin+, whereas MSCs have no telopodes and they were CD34–/c-kit– /vimentin+. Cytokine profile analysis and ELISA showed that 19 of 49 cytokines were increased dramatically in the supernatant of TCs compared with those of MSCs. Moreover, 9 of 19 cytokines were increased 2-fold at least in the supernatant of TCs compared with those of MSCs. Of 49 cytokines, 30 exhibited no significant changes in the supernatant of TCs compared with those of MSCs. Conclusions: Using various technologies, we identified that myocardial TCs and MSCs are significantly different in terms of cell structure and cytokine profiles.

Identification and Interaction Analysis of Molecular Markers in Colorectal Cancer by Integrated Bioinformatics Analysis.

BackgroundColorectal cancer (CRC) is an extremely common gastrointestinal malignancy.Material/MethodsThree mRNA and 2 microRNA microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and microRNAs (DEMs) were obtained. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) program was utilized to perform gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Protein–protein interaction (PPI) network analysis was performed with the Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape and Molecular Complex Detection (MCODE). Kaplan-Meier curves were plotted to determine overall survival (OS) estimates. DEMs targets were predicted by miRWalk. Quantitative reverse transcription polymerase chain reaction (QRT-PCR) was utilized to detect the expression of genes and microRNAs.ResultsA total of 264 DEGs and 8 DEMs were obtained. GO analysis revealed that the DEGs were enriched in terms of cell structure, digestion, receptor binding, and extracellular material (ECM). KEGG pathway analysis showed that the DEGs were enriched in ECM interaction and mineral absorption. Additionally, a PPI network consisting of 181 nodes and 450 edges was established. Three modules with 38 high-degree hubs were extracted from the PPI network and found to be involved in pathways such as chemokine signaling. Five DEGs located in the network of DEM-DEG pairs were associated with the overall survival of CRC patients. Furthermore, hsa-miR-551b was demonstrated to be significantly down-regulated in CRC tissues.ConclusionsThe key biomarkers could provide new clues for CRC.

The Choanoflagellates: Evolution, Biology and Ecology. By Barry S. C. Leadbeater. Cambridge and New York: Cambridge University Press. $125.00. xiii + 315 p.; ill.; choanoflagellate species index, other species index, general index. ISBN: 978-0-521-88444-0. 2015.

Previous articleNext article FreeMicrobiologyThe Choanoflagellates: Evolution, Biology and Ecology. By Barry S. C. Leadbeater. Cambridge and New York: Cambridge University Press. $125.00. xiii + 315 p.; ill.; choanoflagellate species index, other species index, general index. ISBN: 978-0-521-88444-0. 2015.Tom FenchelTom FenchelMarine Biological Laboratory, University of Copenhagen, Helsingør, Denmark Search for more articles by this author Marine Biological Laboratory, University of Copenhagen, Helsingør, DenmarkPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinked InRedditEmailQR Code SectionsMoreThe choanoflagellates comprise a group of nonphotosynthetic protists that occur in fresh and seawater as well as in soils. The cells are characterized by a single flagellum surrounded by a collar: a single layer of microvilli that form a frustum of a cone or a cylinder. The flagellum draws a water current through the collar from the outside, thus retaining suspended bacteria that are subsequently phagocytized at the base of the collar. Some choanoflagellate species occur as single cells while others form cell colonies that may be attached to a solid substratum such as, for example, algal filaments or, in some species, occur as free-swimming colonies. The loricate choanoflagellates are exclusively found in seawater; they live inside a complicated lorica composed of silica spicules. In other groups, cells occur naked or they are covered by an organic theca. Choanoflagellates are important consumers of bacteria in the water column of the sea.Already in the second half of the 19th century it was noted that there is a close similarity between choanoflagellates and choanocytes (a characteristic cell type of sponges) with respect to structure and function. And so it was speculated that the ancestors of sponges and then, perhaps, metazoans in general were colonial choanoflagellates. Much more recent molecular evidence has shown that the choanoflagellates actually do represent a sister group to the metazoans and that this is to some extent supported by similarities in fine structural details of the cells. These results have again led to a revived interest in the choanoflagellates.The author of the book is associated with the University of Birmingham and he is a leading expert on choanoflagellates. His volume includes 10 chapters that treat the three major groups of choanoflagellates with respect to taxonomy, structure, functional biology, and ecology. A final chapter is devoted to the phylogeny of the opisthokonts—a major group among the eukaryotes that include the fungi, choanoflagellates, and the metazoans in addition to a couple of groups represented by unicellular parasites. This chapter provides a critical discussion of different aspects such as whether the choanoflagellate cell is really homologous with the choanocytes of sponges, as well as other evidence for the possible role of choanoflagellates as ancestors of metazoans in terms of cell structure, biochemical aspects, and connections between the cells in colony-forming species.The Choanoflagellates is an excellent and authoritative book that covers all aspects of this group of protozoans and it will remain so for quite some time. It can be warmly recommended to protozoologists and to anyone interested in the origin of metazoans and in the evolution of multicellularity. Previous articleNext article DetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 92, Number 1March 2017 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/690889 For permission to reuse, please contact [email protected]PDF download Crossref reports no articles citing this article.

Mechanism study of alachlor biodegradation by Paecilomyces marquandii with proteomic and metabolomic methods

Alachlor is an herbicide that is widely used worldwide to protect plant crops against broadleaf weeds and annual grasses. However, due to its endocrine-disrupting activity, its application had been banned in the European Union. As described in our earlier work, Paecilomyces marquandii is a microscopic fungus capable of alachlor removal by N-acetyl oxidation. Our current work uses proteomics and metabolomics to gain a better understanding of alachlor biodegradation by the microscopic fungus P. marquandii. The data revealed that the addition of alachlor reduced the culture growth and glucose consumption rates. Moreover, the rates of glycolysis and the tricarboxylic acids (TCA) cycle increased during the initial stage of growth, and there was a shift toward the formation of supplementary materials (UDP-glucose/galactose) and reactive oxygen species (ROS) scavengers (ascorbate). Proteomic analysis revealed that the presence of xenobiotics resulted in a strong upregulation of enzymes related to energy, sugar metabolism and ROS production. However, the unique overexpression of cyanide hydratase in alachlor-containing cultures may implicate this enzyme as the key protein involved in the alachlor biodegradation pathway. The characterization of P. marquandii-mediated alachlor removal in terms of cell structure and function provides a deeper insight into the strategies of microorganisms toward xenobiotic biodegradation.

Conformal growth of anodic nanotubes for dye-sensitized solar cells: part II. Nonplanar electrode.

Anodic titania nanotube array features highly ordered alignment as well as porous nature, and exhibits intriguing properties when employed in a variety of applications. All these profit from the continuous efforts on controlling the nanotube configurations. Recently, nonplanar electrodes have also been used to grow the nanotubes besides the conventional planar counterparts. As such, it is of great interest and significance to complete a picture to link the nanotubes grown on planar and various nonplanar electrodes for a comprehensive understanding of nanotube growing manners, in an attempt to boost their future applications. In the first part of this review, planar electrodes are focused with regard to nanotube growth and application in dye-sensitized solar cells. In this part, the nanotubes grown on patterned or curved surfaces are discussed first with reference to a similar structure of alumina nanopores, which are subsequently used to mirror the growth of nanotubes on cylindrical electrodes (i.e., titanium wires or meshes). The last section focuses on titanium tubular electrodes which are attractive for thermal fluids in view of the drastically reduced thermal conductivity in the presence of anodic nanotubes. As a recent hot topic, wire-shaped dye-sensitized solar cells are deliberated in terms of cell structure, efficiency calculation, merits, challenges and outlook.

Evaluation of glycophenotype in breast cancer by quantum dot-lectin histochemistry

Cell surface glycoconjugates play an important role in differentiation/dedifferentiation processes and lectins are employed to evaluate them by several methodologies. Fluorescent probes are considered a valuable tool because of their ability to provide a particular view, and are more detailed and sensitive in terms of cell structure and molecular content. The aim of this study was to evaluate and compare the expression and distribution of glycoconjugates in normal human breast tissue, and benign (fibroadenoma), and malignantly transformed (invasive ductal carcinoma) breast tissues. For this, we used mercaptosuccinic acid-coated Cadmium Telluride (CdTe) quantum dots (QDs) conjugated with concanavalin A (Con A) or Ulex europaeus agglutinin I (UEA I) lectins to detect α-D-glucose/mannose and L-fucose residues, respectively. The QD-lectin conjugates were evaluated by hemagglutination activity tests and carbohydrate inhibition assays, and were found to remain functional, keeping their fluorescent properties and carbohydrate recognition ability. Fluorescence images showed that different regions of breast tissue expressed particular types of carbohydrates. While the stroma was preferentially and intensely stained by QD-Con A, ductal cells were preferentially labeled by QD-UEA I. These results indicate that QD-lectin conjugates can be used as molecular probes and can help to elucidate the glycoconjugate profile in biological processes.

Attachment organelle ultrastructure correlates with phylogeny, not gliding motility properties, in Mycoplasma pneumoniae relatives

The Mycoplasma pneumoniae cluster is a clade of eight described species which all exhibit cellular polarity. Their polar attachment organelle is a hub of cellular activities including cytadherence and gliding motility, and its duplication in the species M. pneumoniae is coordinated with cell division and DNA replication. The attachment organelle houses a detergent-insoluble, electron-dense core whose presence is required for structural integrity. Although mutant analysis has led to the identification of attachment organelle proteins, the mechanistic basis for the activities of the attachment organelle remains poorly understood, with gliding motility attributed alternatively to the core or to the adhesins. In this study we investigated attachment organelle-associated phenotypes, including gliding motility characteristics and ultrastructural details, in seven species of the M. pneumoniae cluster under identical conditions, allowing direct comparison. We identified gliding ability in three species in which it has not previously been reported, Mycoplasma imitans, Mycoplasma pirum and Mycoplasma testudinis. Across species, ultrastructural features of attachment organelles and their cores do not correlate with gliding speed, and morphological features of cores are inconsistent with predictions about how these structures are involved in the gliding process, disfavouring a prominent, direct role for the electron-dense core in gliding. In addition, we found M. pneumoniae to be an outlier in terms of cell structure with respect to its close relatives, suggesting that it has acquired a special set of adaptations during its evolution.

In terms of cell structure and function, how do the fungi differ from other microbes?

In terms of cell structure and function, how do the fungi differ from other microbes?

Alterations induced by penicillin in the protein profile and cell structure of Group GStreptococcus

We investigated the effect of a subminimal concentration of penicillin on the ultrastructure and protein profile of Group G streptococci. In cells treated with penicillin (1/3 MIC), the protein content increased by 50%, and several protein bands with a molecular mass of 14–70 kDa were detected. In the hydrophilic phase, carbohydrate-containing proteins were detected by PAS staining, and in the hydrophobic phase, a group of proteins that reacted strongly with homologous antisera were observed. In terms of cell structure, Triton X-114 extraction was found to induce alterations in the cross wall of untreated cells. In bacteria treated with penicillin but not extracted with Triton X-114, the cell wall was observed to detach itself, and regions with reduced amounts of cellular material appeared in the cytoplasm. After Triton-X114 extraction, these penicillin-treated cells exhibited profound morphological changes, leading in some cases to lysis.

Types of Cell in Ascites Tumours

THE mouse tumour MCIM (Klein) exists in two sub-lines, the Mss, which only grows in the solid form, and the MAA, which grows as an ascites tumour and also in solid form, designated MA S. The difference between the behaviour of the sub-lines is as yet unexplained in terms of cell structure. Bergstrand and Ringertz have recently found no constant difference on examination with the electron microscope1. These tumours have been investigated recently by means of the aniline-blue staining technique2.

Resonant Effects of Mammalian Erythrocytes in Ultrasonic Fields

The exponential breakdown rate of erythrocytes in intense acoustic fields does not depend on the frequency for sonic fields of constant velocity amplitude. At higher frequencies, the errors in commonly used measuring instruments obscure the effects of varying frequency. Instead of physically measuring the ultrasonic field, we have observed the relative breakdown rates of beef, rabbit, sheep, and human erythrocytes. The ultrasonic energy was applied directly to the suspension from ceramic transducer elements. To compare breakdown rates from one experiment to the next, we held constant the plate voltage, the oscillator frequency, and the transducer current. An additional check was provided by the output from a small ceramic probe inserted into a fixed position in the suspension. No differential frequency effects were observed below 250 kc. Between 300 and 600 kc, optimum frequencies were found at which relative breakdown rates increased markedly. These frequencies are characteristic of the donor species; they represent cellular resonances. The possible interpretations of these resonances in terms of cell structure will be discussed.