Studies of laser brazing with regard to the quality influencing parameters

Laser joining processes, such as brazing and welding, are a common application in industry, especially in the automotive industry. These processes are the key to lightweight and efficient design with regard to the automotive industry. There, laser brazing is used mainly for visible joints due to the superior paint adhesion and surface roughness of brazed joints compared to welds. As laser brazing is applied in the automotive industry without using any fluxes or shielding gas, this leads to a difficulty in maintaining and ensuring the quality of brazed joints. [Continues.

Vergleich von zwei modifizierten dentalen Titanoberflächen mit gleichem Makrodesign im Hinblick auf ihre osseointegrativen Eigenschaften : eine histologische und biomechanische Analyse im Schafmodell

Ziel dieser Studie war die vergleichende Beurteilung zweier Oberflächen von kommerziell erhältlichen Dentalimplantaten an formgleichen Implantatkörpern aus Reintitan hinsichtlich ihrer Osseointegration. Dazu wurden 6 adulten Schafen Implantate (n=36) mit einer feinkristallinen anodisierten (Typ A) oder einer hydrophilen, sandgestrahlt- säuregeätzten (Typ B) Oberfläche (n= 36) in das Os ilium des Beckens eingesetzt. Nach 0, 2, 4 und 8 Wochen wurde bei beiden Implantattypen eine histologische Analyse des Bone-to-Implant-Contact (BIC, n=6) mittels Licht- und Elektronenmikroskopie, sowie eine biomechanische Analyse mittels Removal Torque Test (n=6) durchgeführt. Der implant-stability-quotient (ISQ) wurde bei A und B nach 0, 2, 4 und 8 Wochen anhand der Resonanzfrequenzanalyse (RFA) ermittelt. Beide Implantattypen bewiesen ausgezeichnete Eigenschaften hinsichtlich Osseointegration in diesem Tiermodell, und obwohl sich Unterschiede in der biomechanischen Analyse zeigten, konnten diese in den histologischen Untersuchungen nicht bestätigt werden. Bei vergleichender Betrachtung zeigte Typ B signifikant höhere Torquewerte in der 4 Wochengruppe als Typ A, während Typ A in der RFA der 8 Wochengruppe signifikant höhere Werte zeigte als B. In allen histologischen Analysemethoden konnten keine signifikanten Unterschiede zwischen A und B ermittelt werden. Hinsichtlich des Ziels der Studie zeigten beide Implantattypen gleichwertige Eigenschaften bezüglich ihrer Fähigkeit zur Osseointegration. Aim of this study was to compare two different commercial dental implant surfaces supported by the same implant design to prove the hypothesis of the relevance of their chemical surface modifications on the performance of early peri-implant endosseous healing. In 6 mature sheep either implants (n=36) with a highly crystalline and phosphate-enriched anodized titanium oxide surface (type A), or implants with a hydrophilic, sand-blasted, large grit and acid-etched surface (n=36; type B) were placed in the iliac shaft of the pelvis. After 0, 2, 4, 8 weeks both types of implants were analyzed by histological assessment of the bone-to-implant contact (BIC, n=6) using electron and light microscopy and biomechanical assessment by removal torque testing (n=6). The implant stability quotient was measured after 0, 2, 4 and 8 weeks by Resonance Frequency Analysis (RFA). Both implants proved excellent quality regarding osseointegration although there were differences concerning biomechanical properties that could not be confirmed by histological assessment. Comparing the 2 surfaces it was shown that type B had significantly higher torque values in the 4 weeks group than type A. On the other hand type A had significantly higher RFA values in the 8 weeks group, while no significant differences could be shown in histological evaluations of BIC The two surfaces showed comparable osseointegration in this sheep model

Regimes of atomic diffraction: Raman versus Bragg diffraction in retroreflective geometries

We provide a comprehensive study of atomic Raman and Bragg diffraction when coupling to a pair of counterpropagating light gratings (double diffraction) or to a single one (single diffraction) and discuss the transition from one case to the other in a retroreflective geometry as the Doppler detuning changes. In contrast to single diffraction, double Raman loses its advantage of high diffraction efficiency for short pulses and has to be performed in a Bragg-type regime. Moreover, the structure of double diffraction leads to further limitations for broad momentum distributions on the efficiency of mirror pulses, making the use of (ultra) cold ensembles essential for high diffraction efficiency.Comment: 16 pages, 14 figure

Metabolic changes, hypothalamo-pituitary-adrenal axis and oxidative stress after short-term starvation in healthy pregnant women

Aim: To compare metabolic effects and oxidative stress in pregnant and non-pregnant women after 12h of fasting. Methods: Twenty-six healthy women with uncomplicated singleton pregnancies between the 24th and 28th gestational week were recruited. After an overnight fast, venous blood samples and urine samples were tested for metabolic parameters characteristic for starvation, cortisol and oxidative stress products. Healthy non-pregnant women matched by age, body mass index and length of fasting comprised the control group. Results: The metabolic parameters β-hydroxybutyrate and free fatty acids in blood and ketones in urine showed no differences in pregnant and non-pregnant women. However, the oxidative stress parameters, 8,12-iso-iPF2α-VI, isoprostanes and malondialdehyde were significantly higher in pregnant subjects, as was cortisol. Conclusion: Healthy pregnant women are exposed to oxidative stress and activation of the hypothalamo-pituitary-adrenal axis, but not to metabolic changes resembling starvation during short fasting periods in comparison to non-pregnant healthy wome

Welcome from the Workshop Chairs

Welcome to the fifth International Workshop on Empirical Requirements Engineering (EmpiRE 2015) at RE’15!\ud In the past few years, some important developments in the Information Technology Services marketplace as well as in the software industry in particular fueled the debate on the evaluation of Requirements Engineering (RE) approaches, techniques and tools and the comparison of their usefulness, effectiveness and utility in specific practical contexts. Examples of such market trends include, among many others, the increased interest in collaborative and just-in-time application of RE techniques and the use of software analytics techniques for mining requirements repositories.Also, existing RE technology is more and more being applied in the context of new areas, such as Internet of Things, software ecosystems, green and Cloud computing, to name a few. This increased interest in empirical evaluation is precipitating a growing number of industry-university collaborations in the RE community, which, in turn, is instrumental in generating empirical data through case studies, action research studies, experiments, and surveys. As empirical studies are recognized as invaluable for assessing the actual benefits and cost of applying the RE methods and tools proposed in the RE community, the conversation on adopting these and on evaluation practices intensifies even further

Anti-ganglioside antibodies in patients with Zika virus infection-associated Guillain-Barré Syndrome in Brazil.

Zika virus infection is associated with the development of Guillain-Barré syndrome (GBS), a neurological autoimmune disorder caused by immune recognition of gangliosides and other components at nerve membranes. Using a high-throughput ELISA, we have analyzed the anti-glycolipid antibody profile, including gangliosides, of plasma samples from patients with Zika infections associated or not with GBS in Salvador, Brazil. We have observed that Zika patients that develop GBS present higher levels of anti-ganglioside antibodies when compared to Zika patients without GBS. We also observed that a broad repertoire of gangliosides was targeted by both IgM and IgG anti-self antibodies in these patients. Since Zika virus infects neurons, which contain membrane gangliosides, antigen presentation of these infected cells may trigger the observed autoimmune anti-ganglioside antibodies suggesting direct infection-induced autoantibodies as a cause leading to GBS development. Collectively, our results establish a link between anti-ganglioside antibodies and Zika-associated GBS in patients

CCN2/CTGF promotor activity in the developing and adult mouse eye

CCN2/CTGF is a matricellular protein that is known to enhance transforming growth factor-β signaling and to induce a myofibroblast-like phenotype in a variety of cell types. Here, we investigated Ccn2/Ctgf promotor activity during development and in the adult mouse eye, using CTGFLacZ/+ mice in which the β-galactosidase reporter gene LacZ had been inserted into the open reading frame of Ccn2/Ctgf. Promotor activity was assessed by staining for β-galactosidase activity and by immunolabeling using antibodies against β-galactosidase. Co-immunostaining using antibodies against glutamine synthetase, glial fibrillary acidic protein, choline acetyltransferase, and CD31 was applied to identify specific cell types. Ccn2/Ctgf promotor activity was intense in neural crest-derived cells differentiating to corneal stroma and endothelium, and to the stroma of choroid, iris, ciliary body, and the trabecular meshwork during development. In the adult eye, a persistent and very strong promotor activity was present in the trabecular meshwork outflow pathways. In addition, endothelial cells of Schlemm’s canal, and of retinal and choroidal vessels, retinal astrocytes, Müller glia, and starburst amacrine cells were stained. Very strong promoter activity was seen in the astrocytes of the glial lamina at the optic nerve head. We conclude that CCN2/CTGF signaling is involved in the processes that govern neural crest morphogenesis during ocular development. In the adult eye, CCN2/CTGF likely plays an important role for the trabecular meshwork outflow pathways and the glial lamina of the optic nerve head

Piranha-etched titanium nanostructure reduces biofilm formation in vitro.

OBJECTIVES Nano-modified surfaces for dental implants may improve gingival fibroblast adhesion and antibacterial characteristics through cell-surface interactions. The present study investigated how a nanocavity titanium surface impacts the viability and adhesion of human gingival fibroblasts (HGF-1) and compared its response to Porphyromonas gingivalis with those of marketed implant surfaces. MATERIAL AND METHODS Commercial titanium and zirconia disks, namely, sandblasted and acid-etched titanium (SLA), sandblasted and acid-etched zirconia (ZLA), polished titanium (PT) and polished zirconia (ZrP), and nanostructured disks (NTDs) were tested. Polished titanium disks were etched with a 1:1 combination of 98% H2SO4 and 30% H2O2 (piranha etching) for 5 h at room temperature to produce the NTDs. Atomic force microscopy was used to measure the surface topography, roughness, adhesion force, and work of adhesion. MTT assays and immunofluorescence staining were used to examine cell viability and adhesion after incubation of HGF-1 cells on the disk surfaces. After incubation with P. gingivalis, conventional culture, live/dead staining, and SEM were used to determine the antibacterial properties of NTD, SLA, ZLA, PT, and ZrP. RESULTS Etching created nanocavities with 10-20-nm edge-to-edge diameters. Chemical etching increased the average surface roughness and decreased the surface adherence, while polishing and flattening of ZrP increased adhesion. However, only the NTDs inhibited biofilm formation and bacterial adherence. The NTDs showed antibacterial effects and P. gingivalis vitality reductions. The HGF-1 cells demonstrated greater viability on the NTDs compared to the controls. CONCLUSION Nanocavities with 10-20-nm edge-to-edge diameters on titanium disks hindered P. gingivalis adhesion and supported the adhesion of gingival fibroblasts when compared to the surfaces of currently marketed titanium or zirconia dental implants. CLINICAL RELEVANCE This study prepared an effective antibacterial nanoporous surface, assessed its effects against oral pathogens, and demonstrated that surface characteristics on a nanoscale level influenced oral pathogens and gingival fibroblasts. CLINICAL TRIAL REGISTRATION not applicable

Regulation of Connective Tissue Growth Factor Expression Influences the Cell Viability In Human Trabecular Meshwork Cells

Connective tissue growth factor (CTGF) induces extracellular matrix (ECM) synthesis and contractility in human trabecular meshwork (HTM) cells. Both processes are involved in the pathogenesis of primary open-angle glaucoma. To date, little is known about regulation and function of CTGF expression in the trabecular meshwork (TM). Therefore, we analysed the effects of different aqueous humour proteins and stressors on CTGF expression in HTM cells. HTM cells from three different donors were treated with endothelin-1, insulin-like growth factor (IGF)-1, angiotensin-II, H2O2 and heat shock and were analysed by immunohistochemistry, real-time RT-PCR and Western blotting. Viability after H2O2 treatment was measured in CTGF silenced HTM-N cells and their controls. Latrunculin A reduced expression of CTGF by about 50% compared to untreated HTM cells, whereas endothelin-1, IGF-1, angiotensin-II, heat shock and oxidative stress led to a significant increase. Silencing of CTGF resulted in a delayed expression of αB-crystallin and in reduced cell viability in comparison to the controls after oxidative stress. Conversely, CTGF treatment led to a higher cell viability rate after H2O2 treatment. CTGF expression is induced by factors that have been linked to glaucoma. An increased level of CTGF appears to protect TM cells against damage induced by stress. The beneficial effect of CTGF for viability of TM cells is likely associated with the effects on increased ECM synthesis and higher contractility of the TM, thereby contributing to reduced aqueous humour outflow facility causing increased intraocular pressure

Deficiency of annexins A5 and A6 induces complex changes in the transcriptome of growth plate cartilage but does not inhibit the induction of mineralization

Initiation of mineralization during endochondral ossification is a multistep process and has been assumed to correlate with specific interactions of annexins A5 and A6 and collagens. However, skeletal development appears to be normal in mice deficient for either A5 or A6, and the highly conserved structures led to the assumption that A5 and A6 may fulfill redundant functions. We have now generated mice deficient of both proteins. These mice were viable and fertile and showed no obvious abnormalities. Assessment of skeletal elements using histologic, ultrastructural, and peripheral quantitative computed tomographic methods revealed that mineralization and development of the skeleton were not significantly affected in mutant mice. Otherwise, global gene expression analysis showed subtle changes at the transcriptome level of genes involved in cell growth and intermediate metabolism. These results indicate that annexins A5 and A6 may not represent the essential annexins that promote mineralization in vivo