Review of the Synergies Between Computational Modeling and Experimental Characterization of Materials Across Length Scales

With the increasing interplay between experimental and computational approaches at multiple length scales, new research directions are emerging in materials science and computational mechanics. Such cooperative interactions find many applications in the development, characterization and design of complex material systems. This manuscript provides a broad and comprehensive overview of recent trends where predictive modeling capabilities are developed in conjunction with experiments and advanced characterization to gain a greater insight into structure-properties relationships and study various physical phenomena and mechanisms. The focus of this review is on the intersections of multiscale materials experiments and modeling relevant to the materials mechanics community. After a general discussion on the perspective from various communities, the article focuses on the latest experimental and theoretical opportunities. Emphasis is given to the role of experiments in multiscale models, including insights into how computations can be used as discovery tools for materials engineering, rather than to "simply" support experimental work. This is illustrated by examples from several application areas on structural materials. This manuscript ends with a discussion on some problems and open scientific questions that are being explored in order to advance this relatively new field of research.Comment: 25 pages, 11 figures, review article accepted for publication in J. Mater. Sc

Processing Conditions for Ultrastable Surfactant-Free Nanoparticle Stabilized Foams

Foams, which are mixtures of gas and either a liquid or solid, are important to many applications, from consumer products to industrial processes. Stabilizing the liquid/gas interface against coalescence is key to the performance of foams. Typically, molecular surfactants (surface active agents) are used for interfacial stability, but adsorption/desorption of surfactant can diminish foam performance. We investigated the use of solid nanoparticles, rather than surfactants, as stabilizers. Fumed silica nanoparticles of varying surface chemistry, ranging from hydrophobic to hydrophilic, were suspended at 1% (w/w) and agitated in solutions of water and ethanol. Foam (gas in liquid), suspensions, and inverse foam (“liquid marbles”) structures formed during agitation; these materials were classified into a structure map as a function of processing conditions. We found the agitation intensity, solution chemistry, and surface chemistry of the fumed silica nanoparticles had a profound effect on the final structure and that there was an envelope of optimal processing conditions for producing foam. Coalescence was mitigated for 49 days as of writing this abstract. Superior stability arises from the large energy necessary to remove particles with suitable chemistry from an interface. Thus, both the energy input and system chemistry are central to designing ultrastable foams.https://engagedscholarship.csuohio.edu/u_poster_2015/1044/thumbnail.jp

Processing Conditions for Ultrastable Surfactant-Free Nanoparticle Stabilized Foams

Foams, which are mixtures of gas and either a liquid or solid, are important to many applications, from consumer products to industrial processes. Stabilizing the liquid/gas interface against coalescence is key to the performance of foams. Typically, molecular surfactants (surface active agents) are used for interfacial stability, but adsorption/desorption of surfactant can diminish foam performance. We investigated the use of solid nanoparticles, rather than surfactants, as stabilizers. Fumed silica nanoparticles of varying surface chemistry, ranging from hydrophobic to hydrophilic, were suspended at 1% (w/w) and agitated in solutions of water and ethanol. Foam (gas in liquid), suspensions, and inverse foam (“liquid marbles”) structures formed during agitation; these materials were classified into a structure map as a function of processing conditions. We found the agitation intensity, solution chemistry, and surface chemistry of the fumed silica nanoparticles had a profound effect on the final structure and that there was an envelope of optimal processing conditions for producing foam. Coalescence was mitigated for 49 days as of writing this abstract. Superior stability arises from the large energy necessary to remove particles with suitable chemistry from an interface. Thus, both the energy input and system chemistry are central to designing ultrastable foams.https://engagedscholarship.csuohio.edu/u_poster_2015/1044/thumbnail.jp

The Intrinsic Connectome of the Rat Amygdala

The connectomes of nervous systems or parts there of are becoming important subjects of study as the amount of connectivity data increases. Because most tract-tracing studies are performed on the rat, we conducted a comprehensive analysis of the amygdala connectome of this species resulting in a meta-study. The data were imported into the neuroVIISAS system, where regions of the connectome are organized in a controlled ontology and network analysis can be performed. A weighted digraph represents the bilateral intrinsic (connections of regions of the amygdala) and extrinsic (connections of regions of the amygdala to non-amygdaloid regions) connectome of the amygdala. Its structure as well as its local and global network parameters depend on the arrangement of neuronal entities in the ontology. The intrinsic amygdala connectome is a small-world and scale-free network. The anterior cortical nucleus (72 in- and out-going edges), the posterior nucleus (45), and the anterior basomedial nucleus (44) are the nuclear regions that posses most in- and outdegrees. The posterior nucleus turns out to be the most important nucleus of the intrinsic amygdala network since its Shapley rate is minimal. Within the intrinsic amygdala, regions were determined that are essential for network integrity. These regions are important for behavioral (processing of emotions and motivation) and functional (memory) performances of the amygdala as reported in other studies

MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases.

Low-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor-MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet-induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype. This is accompanied by substantially reduced diet-induced systemic inflammation, insulin resistance, and atherosclerosis. MyD88 deficiency in endothelial cells results in a moderate reduction in diet-induced adipose macrophage infiltration and M1 polarization, selective insulin sensitivity in adipose tissue, and amelioration of spontaneous atherosclerosis. Both in vivo and ex vivo studies suggest that MyD88-dependent GM-CSF production from the endothelial cells might play a critical role in the initiation of obesity-associated inflammation and development of atherosclerosis by priming the monocytes in the adipose and arterial tissues to differentiate into M1-like inflammatory macrophages. Collectively, these results implicate a critical MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases

The Determinants of Within Metropolitan Immigrant Moves

While the role of immigration and neighborhood change has been studied since the days of the Chicago School of Sociology, recent restrictions to immigration in concert with state and local initiatives to both enforce immigration policy or welcome immigrants raises new questions about neighborhood sorting within metropolitan areas. Policy makers are interested in recruiting high skilled and wealthy immigrants to attract investment and create jobs for native-born citizens. Some have endorsed welcoming immigrants as a solution to regional economic development and to stabilize high poverty urban neighborhoods. Are these immigrant recruitment policies realistic given existing patterns of immigrant housing location choice within metropolitan areas? This study will investigate the determinants of immigrant concentration within metropolitan regions such as presence of immigrant serving organizations, tract level poverty, median rents, education, language ability, minority businesses and other variables. In order to answer this question, we analyze normalized Census data from the National Neighborhood Change Database using standard panel data techniques. Findings show that immigrants appear to be interested in choosing tracts with lower median gross rents, and increasing rental opportunities. They are also moving into new areas that immigrants had not been living in the previous decade. Immigrant entrepreneurship is also important for the attraction on immigrants. Local governments that wish to attract immigrants need to provide quality education and affordable rents

Functional analysis and transcriptional output of the Göttingen minipig genome

In the past decade the Göttingen minipig has gained increasing recognition as animal model in pharmaceutical and safety research because it recapitulates many aspects of human physiology and metabolism. Genome-based comparison of drug targets together with quantitative tissue expression analysis allows rational prediction of pharmacology and cross-reactivity of human drugs in animal models thereby improving drug attrition which is an important challenge in the process of drug development.; Here we present a new chromosome level based version of the Göttingen minipig genome together with a comparative transcriptional analysis of tissues with pharmaceutical relevance as basis for translational research. We relied on mapping and assembly of WGS (whole-genome-shotgun sequencing) derived reads to the reference genome of the Duroc pig and predict 19,228 human orthologous protein-coding genes. Genome-based prediction of the sequence of human drug targets enables the prediction of drug cross-reactivity based on conservation of binding sites. We further support the finding that the genome of Sus scrofa contains about ten-times less pseudogenized genes compared to other vertebrates. Among the functional human orthologs of these minipig pseudogenes we found HEPN1, a putative tumor suppressor gene. The genomes of Sus scrofa, the Tibetan boar, the African Bushpig, and the Warthog show sequence conservation of all inactivating HEPN1 mutations suggesting disruption before the evolutionary split of these pig species. We identify 133 Sus scrofa specific, conserved long non-coding RNAs (lncRNAs) in the minipig genome and show that these transcripts are highly conserved in the African pigs and the Tibetan boar suggesting functional significance. Using a new minipig specific microarray we show high conservation of gene expression signatures in 13 tissues with biomedical relevance between humans and adult minipigs. We underline this relationship for minipig and human liver where we could demonstrate similar expression levels for most phase I drug-metabolizing enzymes. Higher expression levels and metabolic activities were found for FMO1, AKR/CRs and for phase II drug metabolizing enzymes in minipig as compared to human. The variability of gene expression in equivalent human and minipig tissues is considerably higher in minipig organs, which is important for study design in case a human target belongs to this variable category in the minipig. The first analysis of gene expression in multiple tissues during development from young to adult shows that the majority of transcriptional programs are concluded four weeks after birth. This finding is in line with the advanced state of human postnatal organ development at comparative age categories and further supports the minipig as model for pediatric drug safety studies.; Genome based assessment of sequence conservation combined with gene expression data in several tissues improves the translational value of the minipig for human drug development. The genome and gene expression data presented here are important resources for researchers using the minipig as model for biomedical research or commercial breeding. Potential impact of our data for comparative genomics, translational research, and experimental medicine are discussed

P1: Salt Concentration and pH Affect the Size of Elastin-Like Polypeptide Nanoparticles

The transport of therapeutic drugs to specific tissues in the body can be accomplished using nanoparticles that encapsulate the drugs. Elastin-like polypeptides (ELP) is a class of materials that can reversibly form such nanoparticles in response to environmental cues. FLPs transition from soluble compounds to a phase separated system under particular solution conditions and have been used to produce temperature responsive surfactants. When these ELP surfactants are above their transition temperature, they spontaneously form energetically stable spherical micelles. When the temperature drops below the transition temperature, the micelles break apart and the ELP goes into solution. The size of these micelles can change depending on the solution conditions, including pH and salt concentration. We studied how the size of the micelles are affected by these solution conditions by using dynamic light scattering to determine the diameter of the ELP micelles. When the salt concentration increased, we found that there was a region of constant size followed by a region of linear increase in diameter. Following the linear region, there is a jump in micelle size. As the pH of the solution increased from neutral pH, the diameter drastically increased. As pH decreased from neutral pH, the diameter slightly increased.https://engagedscholarship.csuohio.edu/u_poster_2017/1045/thumbnail.jp

A monoclinic polymorph of (1E,5E)-1,5-bis­(2-hy­droxy­benzyl­idene)thio­carbono­hydrazide

The title compound, C15H14N4O2S, is a derivative of thio­ureadihydrazide. In contrast to the previously reported polymorph (ortho­rhom­bic, space group Pbca, Z = 8), the current study revealed monoclinic symmetry (space group P21/n, Z = 4). The mol­ecule shows non-crystallographic C 2 as well as approximate C s symmetry. Intra­molecular bifurcated O—H⋯(N,S) hydrogen bonds, are present. In the crystal, inter­molecular N—H⋯S hydrogen bonds and C—H⋯π contacts connect the mol­ecules into undulating chains along the b axis. The shortest centroid–centroid distance between two aromatic systems is 4.5285 (12) Å