Untersuchung einer mehrlagigen Schweißnaht eines dickwandigen Rohres aus dem austenitischen Stahl X6 CrNiNb 18 10

Analysis of a multi pass weld of a thick walled tube made of austenitic stainless steel X6 CrNiNb 18 10 In this paper, microstructure and residual stresses of a multi pass welding of a thick‐walled tube made of austenitic stainless steel X6 CrNiNb 18 10 (1.4550) are systematically characterized and assessed. Results of microstructural and phase analyses, residual stress and hardness measurements as well as of a tensile test using micro specimen and SEM analyses are presented. Using these data, plastic deformations occurring during the welding process in the vicinity of the weld seam are evaluated. Finally, consequences of an additional heat treatment at 400 °C/24 h are studied.     

Evidence for a Turner syndrome locus or loci at Xp11.2-p22.1

Turner syndrome is the complex human phenotype associated with complete or partial monosomy X. Principle features of Turner syndrome include short stature, ovarian failure, and a variety of other anatomic and physiological abnormalities, such as webbed neck, lymphedema, cardiovascular and renal anomalies, hypertension, and autoimmune thyroid disease. We studied 28 apparently nonmosaic subjects with partial deletions of Xp, in order to map loci responsible for various components of the Turner syndrome phenotype. Subjects were carefully evaluated for the presence or absence of Turner syndrome features, and their deletions were mapped by FISH with a panel of Xp markers. Using a statistical method to examine genotype/phenotype correlations, we mapped one or more Turner syndrome traits to a critical region in Xp11.2-p22.1. These traits included short stature, ovarian failure, high-arched palate, and autoimmune thyroid disease. The results are useful for genetic counseling of individuals with partial monosomy X. Study of additional subjects should refine the localization of Turner syndrome loci and provide a rational basis for exploration of candidate genes.     

Interactions of Fibroblasts with Different Morphologies Made of an Engineered Spider Silk Protein

Spider silk has been investigated for decades due to the intriguing mechanical and also biomedical properties of the silk fibers. Previously, it has been shown that recombinant silk proteins can also be processed into other morphologies. Here, we characterized scaffolds made of the recombinant spider silk protein eADF4(C16) concerning their surface interactions with fibroblasts. Studies of BALB/3T3 cells on hydrogels and films made of eADF4(C16) showed low cell adhesion without observable duplication. Electro‐spun non‐woven scaffolds made of eADF4(C16), however, enabled both their adhesion and proliferation. Since eADF4(C16) lacks specific motifs for cell attachment, fibroblasts cannot generate focal adhesions with the material's surface, and, therefore, other cell–interface interactions such as topographical anchorage or cell attachment mediated by adhesion of extracellular matrix proteins are discussed in this paper. On non‐woven meshes protrusion of filopodia and/or lamellipodia between individual fibers increase the surface contact area, which depends on the diameter of the fibers of the non‐woven meshes. In contrast, at flat (film) or microstructured surfaces (hydrogels) such interactions seem to be precluded.     

Body protein losses estimated by nitrogen balance and potassium-40 counting

Body protein losses estimated from N balance were compared with those estimated by 40K counting. Six nonlactating dairy cows were fed an adequate N diet for 7 wk, a low N diet for 9 wk, and a replete N diet for 3 wk. The low N diet contained high cell wall grass hay plus ground corn, starch, and molasses. Soybean meal was added to the low N diet to increase N in the adequate N and replete N diets. Intake was measured daily. Digestibilities, N balance, and body composition (estimated by 40K counting) were determined during each dietary regimen. During low N treatment, hay dry matter intake declined 2 kg/d, and supplement increased about .5 kg/d. Dry matter digestibility was not altered by N treatment. Protein and acid detergent fiber digestibilities decreased from 40 and 36% during adequate N to 20 and 2%, respectively, during low N. Fecal and urinary N also declined when cows were fed the low N diet. By the end of repletion, total intake, fiber, and protein digestibilities as well as N partition were similar to or exceeded those during adequate N intake. Body protein (N) loss was estimated by N balance to be about 3 kg compared with 8 kg by 40K counting. Body fat losses (32 kg) were large because of low energy digestibility and intake. Seven kilograms of body fat were regained during repletion, but there was no change in body protein.     

Novel TTLL5 Variants Associated with Cone-Rod Dystrophy and Early-Onset Severe Retinal Dystrophy

Variants of the TTLL5 gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few TTLL5 patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of TTLL5. Four adult patients presented either COD or CORD with onset in the late teenage years. The youngest patient had a phenotype of early onset severe retinal dystrophy (EOSRD). Genetic analysis was performed by targeted next generation sequencing of gene panels and assessment of copy number variants (CNV). We identified eight variants, of which six were novel, including two large multiexon deletions in patients with COD or CORD, while the EOSRD patient harboured the novel homozygous p.(Trp640*) variant and three distinct USH2A variants, which might explain the observed rod involvement. Our study highlights the role of TTLL5 in COD/CORD and the importance of large deletions. These findings suggest that COD or CORD patients lacking variants in known genes may harbour CNVs to be discovered in TTLL5, previously undetected by classical sequencing methods. In addition, variable phenotypes in TTLL5-associated patients might be due to the presence of additional gene defects.     

Efficient Modular Synthesis of Isomeric Mono‐ and Bispyridyl[2.2]paracyclophanes by Palladium‐Catalyzed Cross‐ Coupling Reactions

Pyridyl‐substituted [2.2]paracyclophanes build a multifunctional structural motif that is useful in material chemistry, catalysis and for luminescent structures. Nonetheless, there is still a lack of general methods for the synthesis of these structures tolerating easily accessible bromides as well as different isomeric pyridyl groups. Hence the coupling of functionalized [2.2]paracyclophanes with various substituted and functionalized pyridyl derivatives was achieved using Stille, Suzuki and Kumada coupling conditions. Hereby the Stille coupling of a [2.2]paracyclophane is presented as a versatile reaction for the formation of heteromeric [2.2]paracyclophane‐containing biaryl structures.

     

Application of activated charcoal in the downstream processing of bacterial olefinic poly(3-hydroxyalkanoates)

Medium chain length poly(hydroxyalkanoates) (mcl-PHAs) are bacterial thermoplastic elastomers with a large potential in medical applications. The present study provides a novel process to isolate and purify poly([R]-3-hydroxy-omega-undecenoate-co-3-hydroxy-omega-nonenoate-co-3-hydroxy-omega-heptenoate) (PHUE) and poly([R]-3-hydroxy-omega-undecenoate-co-3-hydroxy-omega-nonenoate-co-3-hydroxyoctanoate-co-3-hydroxy-omega-heptenoate-co-3-hydroxyhexanoate) (PHOUE) from Pseudomonas putida species. Three different types of activated charcoal were compared with regard to their capability to selectively remove impurities. The product 'Charcoal activated, powder, pure' from Merck was found to be most suitable. Using ethyl acetate as solvent, the polyesters were extracted from freeze-dried biomass at room temperature and simultaneously purified by addition of activated charcoal at the beginning of the extraction. The period of extraction was one hour and the ratio solvent to biomass was 15:1 (vol/wt). After extraction, the solids were separated by pressure filtration through a metallic lace tissue. The filtrate was again passed through the previously accumulated filter cake, followed by a second filtration through a 0.45 microm membrane to remove finest coal particles. The resulting filtrate was concentrated, thus yielding polyesters whose quality and yield depended on the quantity of activated charcoal applied. For highly pure PHUE and PHOUE with low endotoxin levels, the optimum ratio of activated charcoal to solvent for extraction (V/V) was found to be 0.5 for PHUE and 0.25 for PHOUE. The yields with regard to the raw polymers amounted to 55 wt% for PHUE and 75 wt% for PHOUE, which are acceptable for polymers that can be used for medical applications.     

Drag reduction by DNA-grafting for single microspheres in a dilute λ-DNA solution

The fluid resistance of single micrometre-sized blank and DNA-grafted polystyrene microspheres under shear flow is compared in purified water and dilute λ-DNA solutions by means of optical tweezers experiments with a high spatial (±4 nm) and temporal (±0.2 ms) resolution. The measurement results show that the drag experienced by a colloid in a dilute λ-DNA solution (molecular weight of 48,502 bp per molecule, radius of gyration of 0.5 μm) is significantly decreased if the microsphere bears a grafted DNA brush. This newly discovered drag reduction effect is studied for different parameters, comprising the molecular weight of the grafted DNA molecules (250 bp, 1000 bp and 4000 bp), the concentration of the λ-DNA solution (11, 17 and 23 μg ml^?1, all being significantly smaller than the critical entanglement concentration c¹), the microsphere core diameter (2 μm, 3 μm and 6 μm) as well as the flow speed of the medium (10–50 μm s^?1). The maximum extent of the drag reduction is found to amount to (60 ± 20)% compared to the λ-DNA-induced contribution on the drag acting on blank colloids. We propose a theoretical explanation of this effect based on the combination of the dynamic density functional theory of Rauscher and co-workers [Rauscher M. J. Phys.: Condens. Matter 2010;22:364109] and the stagnation length theory of polymer brushes, as it was established by Kim, Lobaskin et al. [Kim et al. Macromolecules 2008;42(10):3650–3655]. In particular, the solution of the Stokes equation (i.e., the Navier–Stokes equation for creeping flow) for the studied system yields a numerical prediction that is found to be in full accord with our experimental results within measurement uncertainty.