Im virtuellen Umfeld von Hochschulen ist in letzter Zeit zunehmend ein Phänomen zu beobachten, das für die Zukunft von Bildungseinrichtungen von maßgeblicher Bedeutung sein könnte. Die Rede ist von selbst gesteuerten Lerngemeinschaften, die das Internet nutzen, um sich gegenseitig bei der Bewältigung des Studiums zu unterstützen. (Auf von Lehrenden didaktisch inszenierte Blended Learning Kurse wird im Rahmen dieses Beitrags nicht eingegangen.)

In den letzten 15 Jahren wurde vorrangig im Rahmen eines Sonderforschungsbereiches an der Technischen Universität Dresden die Verstärkung bestehender Stahlbetonkonstruktionen mit Textilbeton erforscht. Untersuchungen des Textilbetons, welcher aus einem Feinbeton und einer textilen Bewehrung besteht, erfolgten u. a. in Bezug auf seine Wirkung als Biege-, Querkraft- und Normalkraftverstärkung. Die vorliegende Arbeit befasst sich nach Kenntnis des Aufstellers erstmals mit dem Torsionstragverhalten von textilbetonverstärkten Stahlbetonbauteilen. Sie soll somit einen Einstieg in die Thematik schaffen und einen grundlegenden Beitrag für die Forschung sowie die Anwendung des Textilbetons in der Praxis leisten. In einem Überblick zum Stand des Wissens werden Möglichkeiten der Verstärkung sowie allgemeine Eigenschaften der verwendeten Bau- und Verbundstoffe vorgestellt. Des Weiteren erfolgt eine Erläuterung der bereits von anderen Wissenschaftlern durchgeführten experimentellen und theoretischen Untersuchungen zum Torsionstragverhalten von Stahlbetonbauteilen. Für die eigenen experimentellen Untersuchungen war aufgrund der Erkenntnisse aus dem Stand des Wissens zunächst ein neuer Versuchsstand zu entwickeln. Dessen Konstruktion ermöglicht es, reine Torsionsbelastungen in die Probekörper einzuleiten und ist gleichzeitig so flexibel, dass er für die Untersuchung verschiedener Probekörperquerschnitte genutzt werden kann. Nach der Darstellung des neuen Versuchsstandes werden die Ergebnisse der 67 durchgeführten Versuche präsentiert. Diese beinhalten u. a. grundlegende Zusammenhänge zwischen dem Torsionstragverhalten und der Menge, der Anordnung und dem Material der Verstärkung sowie der Bauteilgeometrie aber auch des Zusammenwirkens der textilen Bewehrung mit der Stahlbewehrung. Ein wesentliches Ergebnis der theoretischen Untersuchungen ist ein Ingenieurmodell zur Bestimmung der Torsionstragfähigkeit (Bruchmoment) der verstärkten Stahlbetonbauteile. Für dieses Modell werden – wie im Stahlbetonbau – Stabwerke verwendet, in welche die Geometrie der Bauteile und die Eigenschaften der Baustoffe einfließen. Weiterhin wurde ein erster handhabbarer Berechnungsansatz zur Abschätzung des Rissmomentes erarbeitet. Die dafür angestellten Überlegungen zum Zusammenwirken des Altbetonkerns und der Feinbetonummantelung sowie der rissunterdrückenden Wirkung der textilen Bewehrung sind ausführlich zusammengefasst. Zur Abschätzung der Verformungen im Zustand I und II werden Ansätze aus dem Stahlbetonbau überarbeitet, so dass sie auch bei verstärkten Stahlbetonbauteilen Anwendung finden können. In dem abschießend aufgestellten Bemessungsvorschlag fließen der Stand des Wissens sowie die Erkenntnisse aus den experimentellen und theoretischen Untersuchungen zusammen. In der Zusammenfassung und dem Ausblick wird verdeutlicht, dass mit dieser Arbeit nicht nur ein Einstieg in das Thema Torsionsverstärkung mit Textilbeton geschaffen wurde, sondern mit den Ergebnissen bereits ein begrenzter Einsatz in der Baupraxis denkbar ist. Die im Rahmen der vorliegenden Arbeit aufgezeigten offenen Fragestellungen sollten jedoch im Rahmen fortführender vertiefender Forschungsarbeiten ausführlich untersucht werden.

Theory suggests that plant interactions at the neighbourhood scale play a fundamental role in regulating biodiversity–productivity relationships (BPRs) in tree communities. However, empirical evidence of this prediction is rare, as little is known about how neighbourhood interactions scale up to influence community BPRs. Here, using a biodiversity–ecosystem functioning experiment, we provide insights into processes underlying BPRs by demonstrating that diversity-mediated interactions among local neighbours are a strong regulator of productivity in species mixtures. Our results show that local neighbourhood interactions explain over half of the variation in observed community productivity along a diversity gradient. Overall, individual tree growth increased with neighbourhood species richness, leading to a positive BPR at the community scale. The importance of local-scale neighbourhood effects for regulating community productivity, however, distinctly increased with increasing community species richness. Preserving tree species diversity at the local neighbourhood scale, thus seems to be a promising way for promoting forest productivity.

Plasmacytoid dendritic cells (pDC) constitute a very rare blood cell population and play a significant role in immune response and immune-mediated disorders. Investigations on primary pDCs are hindered not only due to their rarity but also because they represent a heterogeneous cell population which is difficult to culture ex vivo. We generated a conditionally immortalized pDC line (Dox-pDC) from mice with Doxycycline-inducible SV40 Large T Antigen with a comparable immune profile to primary pDCs. The Dox-pDC secrete pro- and anti-inflammatory cytokines upon Toll-like receptor 9 stimulation and upregulate their MHCI, MHCII and costimulatory molecules. Further, the Dox-pDC activate and polarize naïve T cells in vivo and in vitro in response to the model antigen Ovalbumin. Due to their long-term culture stability and their robust proliferation Dox-pDC represent a reliable alternative to primary mouse pDC.

Shungite is a carbonaceous rock which is abundant in Karelia (Russian Federation). Large deposits of shungite with low levels of carbon (approx. 10% C) are also found in Kazakhstan, where it is mined under the trade name Taurit (Koksu Mining Company). Although Taurit has been reported to be used as an adsorbent for hazardous compounds in water treatment, there is very little precise data about its adsorption capacity or the compounds adsorbed. In this study, the ability of Taurit to adsorb Zn(II) was investigated and Freundlich isotherms were determined for both distilled water and tap water. Taurit was found to have a high buffer capacity leading to pH values > 7.0 in aqueous solution. Because dissolved zinc precipitates as Zn(OH)2 under alkaline conditions, the pH must be carefully controlled and kept ≤7.0. Despite the small inner surface area (BET) of Taurit (13.4 m2 g−1), Freundlich coefficients for distilled water (Kf = 2.4, n = 4.0) and tap water (Kf = 1.5, n = 2.5) were similar to other adsorbents. Our results indicate that Taurit could provide a cheap alternative to activated carbon since both substances have a similar adsorption capacity (at least for Zn(II)).

The application of the wrinkle measuring method described in Müller et al. (2017) and the subsequent evaluation algorithm of a range of deep-drawn samples were used to determine the influences and interdependencies of blankholder force, tool temperatures, and drawing height on the formation of wrinkles in paperboard. The main influences were identified and quantitatively evaluated. For the given experimental space, a regression function was derived and validated in further experiments. It was shown that a quadratic regression was superior to the previously used linear regression. The findings were discussed and compared with the results of similar experiments from past publications. Special attention was given to the wrinkles formed and the resulting quality of the formed paperboard cups. The restrictions of the data acquisition from the measuring method that was used and limitations of the model were presented to demonstrate the reliability of the results.

In oral sciences, chitosan application is of interest due to its antimicrobial and hemostatic activity. Chitosan coating of dentures and other intraoral devices could be beneficial for treatment of denture stomatitis or in the management of postoperative bleeding. Disinfection of dentures and prosthodontic materials is crucial before their use in patients. This study investigated the influence of chemical disinfectants on chitosan-coated surfaces. A total of 100 specimens were made: 50 of PMMA (polymethyl methacrylate), and 50 of PETG (polyethylene terephthalate glycol-modified) material and coated with 2% chitosan acetate solution. In each material, 5 groups (10 specimens each) were established and disinfected with Printosept-ID (L1), MD 520 (L2), Silosept (L3), or Dentavon (L4), or stored in distilled water (L0, control group). After disinfection, all specimens underwent abrasion tests (30,000 cycles in a tooth-brushing simulator). Areas without chitosan coating were measured by digital planimetry both before and after the disinfection/abrasion procedure and a damage-score was calculated. Regarding chitosan coating, the statistical analysis showed a significant influence of the disinfectants tested and significant differences between disinfectants (p < 0.05). Chitosan coating was most stable on PMMA and PETG after disinfection with MD 520 (L2). Otherwise, active oxygen containing disinfectants (L3, L4) led to the greatest alterations in the chitosan coating.

Background Creutzfeldt–Jakob disease is a rare and rapidly fatal neurodegenerative disease. Since clinicians may see only very few cases during their professional career, it is important to be familiar with the clinical presentation and progression, to perform appropriate investigations, and allow for quick diagnosis. Case presentation A 73-year-old British Caucasian woman presented with acute confusion of 2 weeks’ duration on a background of low mood following a recent bereavement. Her symptoms included behavioral change, visual hallucinations, vertigo, and recent falls. She was mildly confused, with left-sided hyperreflexia, a wide-based gait, and intention tremor in her left upper limb. Initial blood tests, computed tomography, and magnetic resonance imaging of her brain showed no significant abnormality. Following admission, she had rapid cognitive decline and developed florid and progressive neurological signs; a diagnosis of prion disease was suspected. A lumbar puncture was performed; cerebrospinal fluid was positive for 14–3-3 protein, real-time quaking-induced conversion, and raised levels of s-100b proteins were detected. An electroencephalogram showed bilateral periodic triphasic waves on a slow background. The diagnosis of probable Creutzfeldt–Jakob disease was made. Conclusions This case report highlights key features in the initial presentation and clinical development of a rare but invariably rapidly progressive and fatal disease. It emphasizes the importance of considering a unifying diagnosis for multifaceted clinical presentations. Although it is very rare, Creutzfeldt–Jakob disease should be considered a diagnosis for a mixed neuropsychiatric presentation, particularly with rapid progressive cognitive decline and development of neurological signs. However, to avoid overlooking early signal change on magnetic resonance imaging, it is important to take diffusion-weighted magnetic resonance imaging for all patients with neuropsychological symptoms. Importantly, early diagnosis also ensures the arrangement of suitable contamination control measures to minimize the risk of infection to health care professionals and other patients.

The past years have seen an incredible increase in the quality and success rates of treatments in pediatric medicine. One of the resulting major challenges refers to the management of primary or secondary residual executive function deficits in affected children. These deficits lead to problems in the ability to acquire, understand, and apply abstract and complex knowledge and to plan, direct, and control actions. Executive functions deficits are important to consider because they are highly predictive of functioning in social and academic aspects of daily life. We argue that current clinical practice does not sufficiently account for the complex cognitive processes in this population. This is because widely applied pharmacological interventions only rarely account for the complexity of the underlying neuronal mechanisms and do not fit well into possibly powerful “individualized medicine” approaches. Novel treatment approaches targeting deficits in executive functions in seriously ill children could focus on neuronal oscillations, as these have some specific relations to different aspects of executive function. Importantly, such treatment approaches can be individually tailored to the individuals’ deficits and can be transferred into home-treatment or e-health solutions. These approaches are easy-to-use, can be easily integrated into daily life, and are becoming increasingly cost-effective.

Objectives This randomized controlled trial evaluates the effects of two different rest periods between as set of balance exercises after stroke during inpatient rehabilitation. Results Twenty patients after stroke [11 males; mean (SD) age 65.4 (11.5) years; duration of illness 5.3 (3.4) weeks; 16 (80%) left-sided strokes] were randomly allocated into two groups of either a full rest (FR) of 4 min (n = 10) or a short rest (SR) of 1 min between exercise sets (n = 10). Patients improved from baseline until immediately after exercises in one-leg standing time on the affected leg [SR: mean difference 5.1 s (SD 10.3) and FR: 2.0 s (2.4)] and tandem standing time (TST). [SR: 14.9 s (SD 24.6) and FR: 5.7 s (12.0)], but OLST and TST did not differ significantly between groups (p = 0.35 and p = 0.52, respectively). Trial registration The study was registered retrospectively in the German Register of Clinical Trials with the ID: DRKS00013979