Recent Developments in Crosslinking of Elastomers

2005 ◽  
Vol 78 (3) ◽  
pp. 458-488 ◽  
Author(s):  
Abi Santhosh Aprem ◽  
Kuruvilla Joseph ◽  
Sabu Thomas
Keyword(s):  
Model Compound ◽  
Network Formation ◽  
Double Network ◽  
Different Types ◽  
Recent Developments ◽  
Crosslink Densities

Abstract The recent developments in the vulcanization of elastomers, major types of crosslinking, and mechanism of crosslinking have been reviewed. Attention has been made to sum up the accelerated vulcanization. Possible mechanisms by which the reaction is taking place are discussed. The role of accelerators, activators, and fillers has been described. The different types of crosslinks and importance of each type on the specific properties of the resulting vulcanizates, etc., are discussed. Various aspects of vulcanization like model compound vulcanization, nitrosamine generation, etc., are discussed. The importance of binary accelerators and possible mechanism of their action have been mentioned. The method of double network formation, which is useful for the improvement in properties, is also described. The different methods for characterization of networks and different methods for estimating crosslink densities are also explained.

Pain and Headache

2017 ◽  
Author(s):  
E. Lee Murray ◽  
Karl E. Misulis
Keyword(s):  
Pain Management ◽  
Effective Treatment ◽  
Different Types

Pain can be classified into different types that have anatomic, physiologic, and symptomatic distinctions. Localization and characterization of the pain are essential to diagnosis. The role of the hospital neurologist in pain management is usually twofold: identify the source of the pain and advise on effective treatment.

On the Role of Characterization in the Design of Interfaces in Nanoscale Materials Technology

2004 ◽  
Vol 10 (3) ◽  
pp. 324-335 ◽  
Author(s):  
S.P. Ringer ◽  
K.R. Ratinac
Keyword(s):  
Three Dimensional ◽  
Atom Probe ◽  
Turbine Rotor ◽  
Clay Nanocomposites ◽  
Multimodal Approach ◽  
Transmission Electron ◽  
Different Types ◽  
And Control

This work reviews recent research on the design and control of interfaces in engineering nanomaterials. Four case studies are presented that demonstrate the power of a multimodal approach to the characterization of different types of interfaces. We have used a combination of conventional, high resolution, and analytical transmission electron microscopy, microbeam electron diffraction, and three-dimensional atom probe to study polymer–clay nanocomposites, turbine rotor steels used for power generation, multicomponent aluminum alloys, and nanocrystalline magnetic materials.

scholarly journals (a-)Topics and animacy

2021 ◽  
Author(s):  
Adriana Belletti ◽  
Claudia Manetti
Keyword(s):  
Left Periphery ◽  
Null Subjects ◽  
Object A ◽  
Syntactic Movement ◽  
Relativized Minimality ◽  
Production Experiment ◽  
Different Types ◽  
Mismatch Condition

The aim of this paper is twofold: first, we intend to contribute to the debate on the identification of the features to which syntactic locality expressed in terms of the featural Relativized Minimality/fRM principle appears to be sensitive (Rizzi 2004; Friedmann, Belletti & Rizzi 2009); second, we aim at providing a better characterization of the distributional and interpretive properties of the process of a-marking in the Topic position of the Italian left periphery identified by syntactic cartography, in relation to (in)animacy (Belletti & Manetti 2018). To these aims, we examined the role of animacy in a production experiment eliciting left dislocated topics with 5-year-old children. To the extent that a-marking is related to a kind of affectedness of object topics (Belletti 2018a), we examined whether an inanimate left dislocated object could constitute a felicitous a-Topic. Furthermore, the question whether complexity effects are modulated in the computation of fRM in an animacy mismatch condition (between an inanimate left dislocated object and an intervening (animate) lexical subject) is also addressed within the context of ClLDs. Our results show that, in the tested animacy mismatch condition, children seldom a-marked the pre-posed object. Instead, they appeared to creatively explore other solutions to overcome the production of the hard intervention structure, mainly using null subjects. As children are not ready to compute the intervention configuration with a lexical preverbal subject, but could not naturally adjust it through a-marking of the inanimate topic, they ended up opting for different types of productions in which intervention was eliminated. If the animacy feature seems to be implicated in the process of a-marking to some extent, it is not a feature to which the fRM principle is sensitive in building the object A’-dependency in ClLD: we conclude, in line with previous work, that animacy is not among the features implicated in triggering syntactic movement (in Italian).

scholarly journals Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis?

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2379 ◽  
Author(s):  
Guillermo Rus ◽  
Inas H. Faris ◽  
Jorge Torres ◽  
Antonio Callejas ◽  
Juan Melchor
Keyword(s):  
Soft Tissues ◽  
Elastic Parameters ◽  
Tissue Microstructure ◽  
Non Invasive ◽  
Recent Developments ◽  
Mechanical Biomarkers ◽  
Nonlinear Elastic

The adoption of multiscale approaches by the biomechanical community has caused a major improvement in quality in the mechanical characterization of soft tissues. The recent developments in elastography techniques are enabling in vivo and non-invasive quantification of tissues’ mechanical properties. Elastic changes in a tissue are associated with a broad spectrum of pathologies, which stems from the tissue microstructure, histology and biochemistry. This knowledge is combined with research evidence to provide a powerful diagnostic range of highly prevalent pathologies, from birth and labor disorders (prematurity, induction failures, etc.), to solid tumors (e.g., prostate, cervix, breast, melanoma) and liver fibrosis, just to name a few. This review aims to elucidate the potential of viscous and nonlinear elastic parameters as conceivable diagnostic mechanical biomarkers. First, by providing an insight into the classic role of soft tissue microstructure in linear elasticity; secondly, by understanding how viscosity and nonlinearity could enhance the current diagnosis in elastography; and finally, by compounding preliminary investigations of those elastography parameters within different technologies. In conclusion, evidence of the diagnostic capability of elastic parameters beyond linear stiffness is gaining momentum as a result of the technological and imaging developments in the field of biomechanics.

Molecular mechanisms of iron uptake in eukaryotes

1996 ◽  
Vol 76 (1) ◽  
pp. 31-47 ◽  
Author(s):  
D. M. de Silva ◽  
C. C. Askwith ◽  
J. Kaplan
Keyword(s):  
Iron Uptake ◽  
Mammalian Cells ◽  
Iron Homeostasis ◽  
Molecular Mechanisms ◽  
Iron Acquisition ◽  
Genetic Disorders ◽  
Essential Element ◽  
Recent Developments

Iron serves essential functions in both prokaryotes and eukaryotes, and cells have highly specialized mechanisms for acquiring and handling this metal. The primary mechanism by which the concentration of iron in biologic systems is controlled is through the regulation of iron uptake. Although the role of transferrin in mammalian iron homeostasis has been well characterized, the study of genetic disorders of iron metabolism has revealed other, transferrin-independent, mechanisms by which cells can acquire iron. In an attempt to understand how eukaryotic systems take up this essential element, investigators have begun studying the simple eukaryote Saccharomyces cerevisiae. Several genes have been identified and cloned that act in concert to allow iron acquisition from the environment. Some of these genes appear to have functional homologues in human systems. This review focuses on the recent developments in understanding eukaryotic iron uptake with an emphasis on the genetic and molecular characterization of these systems in both cultured mammalian cells and S. cerevisiae. An unexpected connection between iron and copper homeostasis has been revealed by recent genetic studies, which confirm biologic observations made several decades ago.

scholarly journals The Role of Substrate Temperature and Magnetic Filtering for DLC by Cathodic Arc Evaporation

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 345 ◽  
Author(s):  
Helge Lux ◽  
Matthias Edling ◽  
Massimiliano Lucci ◽  
Julia Kitzmann ◽  
Claus Villringer ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Plasma Source ◽  
Hard Carbon ◽  
Carbon Coatings ◽  
Different Types ◽  
Cathodic Arc Evaporation ◽  
Arc Evaporation ◽  
Cathodic Arc

Diamond-like carbon (DLC) films were deposited using two different types of high current arc evaporation. The first process used a magnetic particle filter to remove droplets from the plasma. For the second process, the samples were put into a metallic cage which was placed directly above the plasma source. For both processes, we varied the substrate temperature from 21 to 350 °C in order to investigate the temperature effect. The samples were characterized using SEM, AFM, XPS, Raman Spectroscopy, Ellipsometry, Photometry, and Nano Indentation in order to compare both methods of deposition and provide a careful characterization of such DLC films. We found that the sp3 content and the hardness can be precisely adjusted by changing the substrate temperature. Furthermore, in the case of unfiltered deposition, the optical constants can be shifted in the direction of higher absorbance in order to produce black and hard carbon coatings.

scholarly journals Purification and characterization of a 100 kDa DNA polymerase from cauliflower inflorescence

1998 ◽  
Vol 332 (2) ◽  
pp. 557-563 ◽  
Author(s):  
Hirokazu SETO ◽  
Masami HATANAKA ◽  
Seisuke KIMURA ◽  
Masahiko OSHIGE ◽  
Yuri TSUYA ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Proliferating Cell Nuclear Antigen ◽  
Nuclear Antigen ◽  
Purification And Characterization ◽  
Synthetic Dna ◽  
Different Types ◽  
Proliferating Cell

A DNA polymerase from cauliflower (Brassica oleracea var. botrytis) inflorescence has been purified to near homogeneity through five successive column chromatographies, and temporally designated cauliflower polymerase 1. Cauliflower polymerase 1 is a monopolypeptide with a molecular mass of 100 kDa. The enzyme efficiently uses synthetic DNA homopolymers and moderately activated DNA and a synthetic RNA homopolymer as template-primers. The enzyme is strongly sensitive to dideoxythymidine triphosphate and N-ethylmaleimide, but it is insensitive to aphidicolin. It was stimulated with 250 mM KCl. Its mode of DNA synthesis is high-processive with or without proliferating-cell nuclear antigen. A 3´ → 5´ exonuclease activity is associated with cauliflower polymerase 1. The enzyme is clearly different from cauliflower mitochondrial polymerase and does not resemble the four different types of wheat DNA polymerase, designated wheat DNA polymerases A, B, CI and CII. In the present paper the role of the enzyme in plant DNA synthesis is discussed.

scholarly journals The atopic desease development in infants and preschool children in Lesnoy town of Sverdlovsk region

2015 ◽  
Vol 12 (2) ◽  
pp. 59-63
Author(s):  
N A Volkova ◽  
I A Tuzankina ◽  
V N Shershnev
Keyword(s):  
Preschool Children ◽  
Clinical Symptoms ◽  
Allergic Diseases ◽  
Specific Ige ◽  
Atopic Diseases ◽  
Different Types ◽  
Specific Ige Antibodies ◽  
Airborne Allergens

The aim of study. To determine the structure of atopic diseases and characterization of different allergens in their progression in infants and preschool children in Lesnoy town. Material and methods. We studied a spectrum of allergen-specific IgE antibodies in children’s blood with different allergic diseases. Comparative analysis of the results was conducted with methods of mathematical statistics. Results. Our data demonstrate the different stages of formation of atopic diseases in children. We revealed that clinical symptoms of atopic diseases and relevance of allergens were changing gradually as children were getting older. Our results showed that the role of nutrition allergens is reduced while airborne allergens came to the fore. Conclusion. Formation and progression of atopic diseases are determined by various allergens. The temporary relevance of different types of allergens indicates a diversity of multivalent sensibilization during affection of the «shock» organ; the result of this phenomenon appears as atopic march. Detection the relevant causative allergens is important for prevention of progression of allergic diseases.

scholarly journals Different Types of Cellular Stress Affect the Proteome Composition of Small Extracellular Vesicles: A Mini Review

Proteomes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 23 ◽  
Author(s):  
Agata Abramowicz ◽  
Piotr Widłak ◽  
Monika Pietrowska
Keyword(s):  
Extracellular Vesicles ◽  
Cellular Response ◽  
Stress Factors ◽  
Functional Importance ◽  
Different Types ◽  
Response To Stress ◽  
Experimental Works ◽  
Stressed Cells

Extracellular vesicles (EVs) are well-known mediators of the cellular response to different stress factors, yet the exact mechanism of their action remains unclear. Hence, the characterization of their cargo, consisting of proteins, nucleic acids, and different classes of metabolites, helps to elucidate an understanding of their function in stress-related communication. The unexpected diversity and complexity of these vesicles requires the incorporation of multiple technologically advanced approaches in EV-oriented studies. This mini review focuses on the invaluable role of proteomics, especially mass spectrometry-based tools, in the investigation of the role of small EVs in their response to stress. Though relatively few experimental works address this issue to date, the available data indicate that stress conditions would affect the composition of protein cargo of vesicles released by stressed cells, as evidenced by the functional importance of such changes in the context of the response of recipient cells.

scholarly journals Dissecting the Effect of a 3D Microscaffold on the Transcriptome of Neural Stem Cells with Computational Approaches: A Focus on Mechanotransduction

2020 ◽  
Vol 21 (18) ◽  
pp. 6775 ◽  
Author(s):  
Federica Rey ◽  
Cecilia Pandini ◽  
Bianca Barzaghini ◽  
Letizia Messa ◽  
Toniella Giallongo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Regenerative Medicine ◽  
Mechanical Stimuli ◽  
Rna Seq ◽  
3D Cell Cultures ◽  
Different Types ◽  
Strongly Connected ◽  
Molecular Bases

3D cell cultures are becoming more and more important in the field of regenerative medicine due to their ability to mimic the cellular physiological microenvironment. Among the different types of 3D scaffolds, we focus on the Nichoid, a miniaturized scaffold with a structure inspired by the natural staminal niche. The Nichoid can activate cellular responses simply by subjecting the cells to mechanical stimuli. This kind of influence results in different cellular morphology and organization, but the molecular bases of these changes remain largely unknown. Through RNA-Seq approach on murine neural precursors stem cells expanded inside the Nichoid, we investigated the deregulated genes and pathways showing that the Nichoid causes alteration in genes strongly connected to mechanobiological functions. Moreover, we fully dissected this mechanism highlighting how the changes start at a membrane level, with subsequent alterations in the cytoskeleton, signaling pathways, and metabolism, all leading to a final alteration in gene expression. The results shown here demonstrate that the Nichoid influences the biological and genetic response of stem cells thorough specific alterations of cellular signaling. The characterization of these pathways elucidates the role of mechanical manipulation on stem cells, with possible implications in regenerative medicine applications.

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