direct laser interference patterning of stainless steel by ultrashort pulses for antibacterial surfaces

Abstract Direct Laser Interference Patterning (DLIP) with ultrashort pulses was exploited to produce tailored periodic sub-micrometer structures on stainless steel surfaces to reduce bacterial attachment and retention. Laser pulses with wavelength 1030 nm and duration 8 ps were employed to form a two-beam line interference pattern that was applied in a two-pass strategy to produce fine cross-wise surface structures with a period of ~ 850 nm and a depth of ~ 500 nm. The laser setup and process parameters were selected based on a simple theoretical model of the resulting interference pattern and ablation depth to limit the number of contact points available for bacterial cells with dimensions 500–2000 nm. Periodic 'cones' and 'holes' were produced covering areas of 250 mm2 with the same interference pattern by exploiting the dependence of laser-induced periodic surface structures on polarization. Cones and holes yielded reductions in E. coli retention of 99.8% and 99.4%, respectively, and S. aureus retention of 70.6% and 79.1%, respectively, after two hours immersion in bacterial solution compared to reference samples. Such reductions achieved over large surface areas suggests that this approach is appropriate for upscaling and high throughput production of antibacterial metallic surfaces in the food and healthcare industries

Short-termed changes in quantitative ultrasound estimated bone density among young men in an 18-weeks follow-up during their basic training for the Swiss Armed Forces

Background Quantitative Ultrasound (QUS) methods have been widely used to assess estimated bone density. This study aimed to assess changes in estimated bone density in association with changes in body composition, physical activity, and anthropometry. Methods We examined changes in anthropometry, body composition, and physical activity associated with changes in estimated bone mineral density (measured using quantitative ultrasound with a heel ultrasound device indicating broadband ultrasound attenuation BUA and speed of sound SOS) in a follow-up sample of n = 73 young men at the beginning and again 18 weeks later at the end of basic military training. Results At the end of the basic training, the subjects were on average significantly heavier (+1.0%), slightly taller (+0.5%) and had a higher fat mass (+6.6%) and grip strength (+8.6%). A significant decrease in mean physical activity (−49.5%) and mean estimated bone density calculated with BUA (−7.5%) was observed in the paired t-test. The results of the multivariable linear regressions (backward selection) show that changes in skeletal muscle mass (delta = 2nd measurement minus 1st measurement) have negative and body weight (delta) have positive association with the speed of sound SOS (delta), while fat mass (delta) and physical activity (delta) had the strongest negative associations with estimated bone mineral density (delta). In particular, we found a negative association between fat mass (delta) and estimated bone mineral density (delta, estimated with BUA). Conclusion Our study suggests that estimated bone density from the calcaneus can change within a few months even in young and mostly healthy individuals, depending upon physical activity levels and other co-factors. Further studies including other troop types as control groups as well as on women should follow in order to investigate this public health relevant topic in more depth. To what extent the estimated bone density measurement with quantitative ultrasound is clinically relevant needs to be investigated in further studies

Attenuation of Doxorubicin-Induced Small Intestinal Mucositis by Pectins is Dependent on Pectin's Methyl-Ester Number and Distribution

Scope Intestinal mucositis is a common side effect of the chemotherapeutic agent doxorubicin, which is characterized by severe Toll-like receptor (TLR) 2-mediated inflammation. The dietary fiber pectin is shown to prevent this intestinal inflammation through direct inhibition of TLR2 in a microbiota-independent manner. Recent in vitro studies show that inhibition of TLR2 is determined by the number and distribution of methyl-esters of pectins. Therefore, it is hypothesized that the degree of methyl-esterification (DM) and the degree of blockiness (DB) of pectins determine attenuating efficacy on doxorubicin-induced intestinal mucositis. Methods and Results Four structurally different pectins that differed in DM and DB are tested on inhibitory effects on murine TLR2 in vitro, and on doxorubicin-induced intestinal mucositis in mice. These data demonstrate that low DM pectins or intermediate DM pectins with high DB have the strongest inhibitory impact on murine TLR2-1 and the strongest attenuating effect on TLR2-induced apoptosis and peritonitis. Intermediate DM pectin with a low DB is, however, also effective in preventing the induction of doxorubicin-induced intestinal damage. Conclusion These pectin structures with stronger TLR2-inhibiting properties may prevent the development of doxorubicin-induced intestinal damage in patients undergoing chemotherapeutic treatment with doxorubicin

Developing Mn-doped lead sulfide quantum dots for MRI labels

Magnetic interactions of Mn2+ions in lead sulfide (PbS) nanocrystals with protons in water are probed by NMR and MRI. A thin layer of capping molecules enables free solvent diffusion to the nanocrystal surface resulting in a decrease of proton relaxation times. Magnetic resonance imaging of neuronal cell pellets exposed to (PbMn)S at non-toxic concentrations demonstrates their prospects as MRI-labels

Cosmopolitanism and the relevance of ‘zombie concepts’: the case of anomic suicide amongst Alevi Kurd youth

Against Beck’s claims that conventional sociological concepts and categories are zombie categories, this paper argues that Durkheim’s theoretical framework in which suicide is a symptom of an anomic state of society can help us understand the diversity of trajectories that transnational migrants follow and that shape their suicide rates within a cosmopolitan society. Drawing on ethnographic data collected on eight suicides and three attempted suicide cases of second-generation male Alevi Kurdish migrants living in London, this article explains the impact of segmented assimilation/adaptation trajectories on the incidence of suicide and how their membership of a ‘new rainbow underclass’, as a manifestation of cosmopolitan society, is itself an anomic social position with a lack of integration and regulation

Special issue conclusion : The GLES Open Science Challenge 2021 in hindsight: experiences gained and lessons learned

Die GLES Open Science Challenge 2021 ist ein Pilotprojekt, das zeigt, dass Registered Reports ein geeignetes und gewinnbringendes Publikationsformat in der quantitativen Politikwissenschaft sind, die dazu beitragen können, die Transparenz und Replizierbarkeit im Forschungsprozess zu erhöhen und somit substanzielle und relevante Beiträge für unsere Disziplin zu liefern. Das Ergebnis ist die Veröffentlichung dieses Sonderheftes mit sieben Registered Reports, die auf Daten der German Longitudinal Election Study (GLES) basieren, die im Rahmen der Bundestagswahl 2021 erhoben wurden. Dieser abschließende Artikel des Sonderheftes bringt die Perspektiven von Autor*innen, Gutachter*innen, Organisator*innen und Herausgeber*innen zusammen, um eine Bilanz der verschiedenen Erfahrungen und Lehren zu ziehen, die im Laufe dieses Projektes gewonnen wurden

Sedimentological and Rheological Properties of the Water–Solid Bed Interface in the Weser and Ems Estuaries, North Sea, Germany: Implications for Fluid Mud Classification

Fine, cohesive sediment suspensions are a common feature of estuarine environments. Generally, multilayer models are used to describe the vertical distribution of such sediments. Such conceptional models normally distinguish at least high suspended sediment concentrations (SSCs) as a topmost layer and a consolidated bed layer, often including an intermediate, fluid mud layer. Rheological, and in particular sedimentological properties are rarely included in these models. New data from two different estuaries provide new insights that can contribute toward the classification of nearbed cohesive sediments. The water–solid bed interfaces within the turbidity maximum zones of the Weser and Ems estuaries were sampled with 2–4-m-long cores. At 10-cm intervals, values of SSC, viscosity, particulate organic matter, mud: sand ratio, temperature, salinity, and grain-size distributions were determined. By normalizing these parameters to SSC and performing a cluster analysis, sediment suspensions of <20 g/L SSC, fluid mud with up to 500 g/L SSC, and an underlying cohesive/consolidated bed can each clearly be distinguished. However, changes in flow behaviour and sedimentological characteristics represented by a shift in the cluster grouping support a subdivision of the fluid mud into a low-viscosity (I) (20–200 g/L SSC) and a high-viscosity (II) (200–500 g/L SSC) layer. Furthermore, by normalizing SSC measurements, site-specific differences were observed in the rheological behaviour of the fluid mud which might be caused by differences in grain-size composition. This suggests that the widely accepted 3-layer model of vertical SSC profiles should be extended by two layers of fluid mud identified in this study

H1N1 outbreak in a Swiss military boot camp--observations and suggestions

The A(H1N1)pdm09 influenza virus is a highly contagious pathogen which caused the 2009 influenza pandemic. The virus is known to affect mainly younger people and may be a problem in crowded living conditions. The aim of the study was to describe a major A(H1N1)pdm09 outbreak in a Swiss military boot camp and to develop suggestions for similar future situations