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In this work the effects on numerical calculations of in-flight particle motion and heating within a semi-industrial scale shaft furnace are presented. Therefore, experiments and numerical calculations with a type of boiler slag powder were conducted. It consists of particles with various size and shape. The obtained results were used for validation purposes of the proposed numerical model. This model differs in two main modifications compared to the current state-of-the-art CFD models. First, the application of a numerically inexpensive combustion model with a detailed chemical reaction mechanism enabled a significant reduction of the computational demand. Furthermore, the used burner type in the furnace with its characteristics can be modeled with sufficient accuracy. Second, various particle sizes and shapes were considered within the numerical model by application of corresponding drag formulations and empirically determined drag model parameters. Latter were obtained using a particle classification method proposed in a previous study. With this approach influences due to particle drag, rotation, oscillation and surface friction of different particle sizes and shapes were considered. Nevertheless, particle trajectories and heat transfer between particles and the fluid can be modeled with a low computational effort. The obtained results were compared to a commonly used approach, considering only one particle shape factor and one particle injection. Resulting particle trajectories and temperatures reveal significant differences between the latter and the proposed approach. Finally, influences on the heating characteristics due to preheated combustion air were investigated. It was shown that particle trajectory and temperature calculations in the shaft furnace are mainly affected by considering various particle shapes. Furthermore, the numerical results were improved by applying empiric model parameters. Using preheated combustion air as oxidizer results in a higher amount of spheroidized particles.

Heterogeneity in the metabolic properties of adipocytes in white adipose tissue has been well documented. We sought to investigate metabolic heterogeneity in adipocytes of brown adipose tissue (BAT), focusing on heterogeneity in nutrient uptake. To explore the possibility of metabolic heterogeneity in brown adipocytes, we used nanoscale secondary ion mass spectrometry (NanoSIMS) to quantify uptake of lipids in adipocytes interscapular BAT and perivascular adipose tissue (PVAT) after an intravenous injection of triglyceride-rich lipoproteins (TRLs) containing [ 2 H]triglycerides ( 2 H-TRLs). The uptake of deuterated lipids into brown adipocytes was quantified by NanoSIMS. We also examined 13 C enrichment in brown adipocytes after administering [ 13 C]glucose or 13 C-labeled mixed fatty acids by gastric gavage. The uptake of 2 H-TRLs-derived lipids into brown adipocytes was heterogeneous, with 2 H enrichment in adjacent adipocytes varying by more than fourfold. We also observed substantial heterogeneity in 13 C enrichment in adjacent brown adipocytes after administering [ 13 C]glucose or [ 13 C]fatty acids by gastric gavage. The uptake of nutrients by adjacent brown adipocytes within a single depot is variable, suggesting that there is heterogeneity in the metabolic properties of brown adipocytes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

A panel of methods of general suitability for complete structural elucidation of the stereochemistry of cyclopeptides, depsipeptides and lipopeptides is presented and described in detail. The suitability of the proposed methods was exemplified on the lipopeptide poaeamide from Pseudomonas poae. Amino acid configurations have been assigned by direct LC enantiomer separation with Chiralpak ZWIX(+) and were confirmed by GC enantiomer separation on Chirasil L-Val. 3-Hydroxydecanoic acid absolute configuration was analyzed on Chiralpak ZWIX(+) and confirmed by injection on ZWIX(-) which showed opposite elution order. Plenty of d-amino acids have been found in this lipopeptide. It contained in total 5 Leu residues of which one had d-configuration. The position of the d-Leu in the peptide sequence was determined by pepsin and chemical digestions in combination with isolation of diagnostic peptide-fragments and subsequent identification of absolute configurations of the Leu residues. This allowed pinpointing the position of the d-amino acid. The complementarity of the peptide retention profiles on Chiralpak ZWIX column as compared to both RPLC and HILIC suggests its great utility as an alternative peptide separation tool., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Molecular profiles of adhesion secretions of Gromphadorrhina portentosa (Madagascar hissing cockroach, Blattodea) were investigated by gas chromatography mass spectrometry with particular focus on a comprehensive analysis of linear and branched hydrocarbons. For this purpose, secretions from the tarsi (feet), possibly contributing to adhesion on smooth surfaces, and control samples taken from the tibiae (lower legs), which contain general cuticular hydrocarbons that are supposed to be not involved in the biological adhesion function, were analyzed and their molecular fingerprints compared. A major analytical difficulty in such a study constitutes the representative, spatially controlled, precise and reproducible sampling from a living insect as well as the minute quantities of insect secretions on both tarsi and tibiae. Thus, three different in vivo sampling methods were compared in terms of sampling reproducibility and extraction efficiency by replicate measurement of samples from tarsi and tibiae. While contact solid-phase microextraction (SPME) with a polydimethylsiloxane (PDMS) fiber showed higher peak intensities, a self-made uncoated glass fiber had the best repeatability in contact-SPME sampling. Chromatographic profiles of these two contact-SPME sampling methods were statistically not significantly different. Inter-individual variances were larger than potentially existing minor differences in molecular patterns of distinct sampling methods. Sampling by solvent extraction was time consuming, showed lower sensitivities and was less reproducible. In general, sampling by contact-SPME with a cheap glass fiber turned out to be a viable alternative to PDMS-SPME sampling. Hydrocarbon patterns of the tarsal adhesion secretions were qualitatively similar to those of epicuticular hydrocarbon profiles of the tibiae. However, hydrocarbons were in general less abundant in tarsal secretions than secretions from tibiae., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This article reports on the chemical analysis of molecular profiles of tarsal secretions of the desert locust Schistocerca gregaria (Forsskål, 1775) by gas chromatography hyphenated with quadrupol mass spectrometry (GC-MS) as well as (1)H-nuclear magnetic resonance ((1)H NMR) spectroscopy. Special focus of this study was to elaborate on sampling methods which enable selective microscale extraction of insect secretions in a spatially controlled manner, in particular tarsal adhesive secretions and secretions located on cuticle surfaces at the tibia. Various solvent sampling procedures and contact solid-phase microextraction (SPME) methods were compared in terms of comprehensiveness and extraction efficiencies as measured by signal intensities in GC-MS. Solvent sampling with water as extraction solvent gave access to the elucidation of chemical profiles of polar compound classes such as amino acids and carbohydrates, but is extremely tedious. Contact SPME on the other hand can be regarded as a simplified and more elegant alternative, in particular for the lipophilic compound fraction. Many proteinogenic amino acids and ornithine as well as carbohydrate monomers arabinose, xylose, glucose, and galactose were detected in tarsal secretions after acid hydrolysis of aqueous extracts. Qualitatively similar but quantitatively significantly different molecular profiles were found for the lipid fraction which contained mainly n-alkanes and internally branched monomethyl-, dimethyl-, and trimethyl-alkanes in the C23-C49 range as well as long chain fatty acids and aldehydes. Especially, hydrocarbons with >C40 carbon numbers have previously been rarely reported for insect secretions. The results suggest that the investigated insect secretions are complex emulsions which allow the attachment of tarsi on various otherwise incompatible materials of smooth and rough surfaces. The solid consistence of the established alkanes at ambient temperatures might contribute to a semi-solid consistence of the adhesive, amalgamating partly opposing functions such as slip resistance, tarsal release, desiccation resistance, and mechanical compliance. The methods developed can be extended to other similar applications of studying compositions of insect secretions of other species., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Blood vessel development is a vital process during embryonic development, during tissue growth, regeneration and disease processes in the adult. In the past decade researchers have begun to unravel basic molecular mechanisms that regulate the formation of vascular lumen, sprouting angiogenesis, fusion of vessels, and pruning of the vascular plexus. The understanding of the biology of these angiogenic processes is increasingly driven through studies on vascular development at the cellular resolution. Single cell analysis in vivo, advanced genetic tools and the widespread use of powerful animal models combined with improved imaging possibilities are delivering new insights into endothelial cell form, function and behavior angiogenesis. Moreover, the combination of in silico modeling and experimentation including dynamic imaging promotes insights into higher level cooperative behavior leading to functional patterning of vascular networks. Here we summarize recent concepts and advances in the field of vascular development, focusing in detail on the endothelial cell., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Blood vessel development requires orchestrated activities of heterogeneous endothelial cell (EC) populations to create a hierarchically branched tubular network. Endothelial heterogeneity is manifested in organ-specific endothelial differentiation and function in the mature vasculature. During sprouting angiogenesis, ECs are specified by Dll4/Notch signalling into leading tip cells and following stalk cells, which together through coordinated migration and proliferation shape the nascent vascular sprout. Wnt-signalling influences many aspects of branching tubulogenesis in various species and organ systems, often in coordination with Notch signalling. Recent advances in vascular biology highlight important roles for multiple components of the Wnt-signalling pathway in regulating cell differentiation, proliferation, survival, cell junctions and polarity. Here, we review the emerging concepts of the molecular actions of Wnt-signalling in regulating differential behaviour and/or cell functions during vascular development.

Blood vessel maturation and stability require recruitment of mural cells (MCs) to the nascent vessel. Loss or detachment of MCs causes vascular dysfunction in diseases. N-sulfation of heparan sulfate (HS) is required for platelet-derived growth factor B (PDGF-B) retention and platelet-derived growth factor receptor-beta (PDGFR-beta) signaling during MC recruitment. To analyze the specific role of MC-derived HS in this process, we inactivated HS synthesis in MCs. MC-specific loss of HS causes embryonic lethality associated with vascular patterning defects, edema, and hemorrhages during late gestation. MC recruitment in the skin is impaired, correlating with defective PDGFR-beta and transforming growth factor-beta (TGF-beta)-SMAD signaling. Accumulation of rounded cells positive for MC markers close to the vessels indicates defective polarization and migration of local MC progenitors. In contrast, MC recruitment and signaling in the central nervous system (CNS) are unaffected by MC HS loss. Our results suggest that HS is selectively required in a cell-autonomous manner, acting in cis with PDGFR-beta and TGF-beta receptors during induction/polarization and migration of local progenitor cells to the nascent vessel. Once MCs are in contact with the vessel, as during CNS vascularization, endothelial HS appears sufficient to facilitate PDGFR-beta activation in trans.

Angiogenic sprouting requires functional specialisation of endothelial cells into leading tip cells and following stalk cells. Experimental data illustrate that induction of the tip cell phenotype is dependent on the protein VEGF-A; however, the process of tip cell selection is not fully understood. Here we introduce a hierarchical agent-based model simulating a suggested feedback loop that links VEGF-A tip cell induction with delta-like 4 (Dll4)/notch-mediated lateral inhibition. The model identifies VEGF-A concentration, VEGF-A gradients and filopodia extension as critical parameters in determining the robustness of tip/stalk patterning. The behaviour of the model provides new mechanistic insights into the vascular patterning defects observed in pathologically high VEGF-A, such as diabetic retinopathy and tumour angiogenesis. We investigate the role of cell morphology in tip/stalk patterning, highlighting filopodia as lateral inhibition amplifiers. The model has been used to make a number of predictions, which are now being tested experimentally, including: (1) levels of Dll4/VEGFR-2, or related downstream proteins, oscillate in synchrony along a vessel in high VEGF environments; (2) a VEGF gradient increases tip cell selection rate.

To determine the function of VEGF-A in nervous system development, we have utilized the Nestin promoter-driven Cre recombinase transgene, in conjunction with a conditional and hypomorphic VEGF-A allele, to lower VEGF-A activity in neural progenitor cells. Mice with intermediate levels of VEGF-A activity showed decreased blood vessel branching and density in the cortex and retina, resulting in a thinner retina and aberrant structural organization of the cortex. Severe reductions in VEGF-A led to decreases in vascularity and subsequent hypoxia, resulting in the specific degeneration of the cerebral cortex and neonatal lethality. Decreased neuronal proliferation and hypoxia was evident at E11.5, leading to increased neuronal apoptosis in the cortex by E15.5. In order to address whether the observed changes in the structural organization of the nervous system were due to a direct and autocrine role of VEGF-A on the neural population, we conditionally inactivated the main VEGF-A receptor, Flk1, specifically in neuronal lineages, by using the Nestin Cre transgene. The normality of these mice ruled out the possibility that VEGF-A/Flk1 signaling has a significant autocrine role in CNS development. VEGF-A dosage is therefore a critical parameter regulating the density of the vascular plexus in the developing CNS that is in turn a key determinant in the development and architectural organization of the nervous system.

Here we report a new isolation method for mouse glomeruli. The method is fast and simple and allows for the isolation of virtually all glomeruli present in the adult mouse kidney with minimal contamination of nonglomerular cells. Mice were perfused through the heart with magnetic 4.5- micro m diameter Dynabeads. Kidneys were minced into small pieces, digested by collagenase, filtered, and collected using a magnet. The number of glomeruli retrieved from one adult mouse was 20,131 +/- 4699 (mean +/- SD, n = 14) with a purity of 97.5 +/- 1.7%. The isolated glomeruli retained intact morphology, as confirmed by light and electron microscopy, as well as intact mRNA integrity, as confirmed by Northern blot analysis. The method was applicable also to newborn mice, which allows for the isolation of immature developmental stage glomeruli. This method makes feasible transcript profiling and proteomic analysis of the developing, healthy and diseased mouse glomerulus.