Investigation of Dye-sensitized Photoanodes and Tris(2,2’-bipyridine)cobalt Redox Mediators Using Scanning Electrochemical Microscopy

Scanning electrochemical microscopy (SECM) was employed in feedback (FB) mode to study the kinetics of the dye regeneration in dye-sensitized solar cells (DSC) with tris(2,2’-bipyridine)cobalt(II/III) ([Co(bpy)3]2+/3+) as redox mediator. Major studies were performed with the triphenylamine-based metal-free dyes D35 and D45 where the impact of the dye architecture on the kinetics in a DSC was investigated. Herein, SECM was used for the first time to determine the dye regeneration rate constant kox of a photooxidized organic dye by the one-electron redox mediator [Co(bpy)3]2+/3+ considering a correct stoichiometry. Nanostructured DSCs fabricated from TiO2 and D35 were imaged using shear force distance control SECM in FB mode. While it was not possible to resolve the response of individual sensitized TiO2 nanoparticles due to their small size compared to the microelectrode, local differences in the performance of screen-printed photoanodes could be resolved

Dynamics of Cyber Hate in Social Media : A Comparative Analysis of Anti-Muslim Movements in the Czech Republic and Germany

In this paper, we address the issue of cyber hate in two selected cases of social movements from Central Europe, namely Pegida from Germany and Initiatives against Islam from the Czech Republic. Based on the Intergroup Contact Theory and previous research of cyber hate, we focus on the users of pages related to the above-mentioned movements on Facebook. For this purpose we use samples of user comments which are presented on the Facebook pages of the above-mentioned movements and we identify and measure the percentage of hateful comments, their targeting and trigger events by using a qualitative coding method. The research results show that in cyberspace, hate comments are more frequent in the case of the Czech Initiative against Islam. The targeting of these comments is very similar in both countries and we are able to classify immigrants and refugees, Muslims in general, governments in both countries, political elites (EU, USA), and people who are in favour of immigrants or refugees (most often from NGOs) as individual targets. Trigger events are linked across both countries and the largest cyber hate instigators are incidents in which refugees and immigrants are presented as perpetrators, as well as issues of asylum policy in general

HERDING CATS: OR MODEL-BASED ALIGNMENT OF HETEROGENEOUS PRACTICES

This paper reports on a study of how practitioners in engineering design try to develop and use models of the design space of the enterprise in support of collaborative work within global production networks. The paper also examines the difficulties they face in developing these models

Modellierung und Simulation von Knochenanpassungsprozessen

Bone is a living tissue that is constantly changing. The stability and risk of fracture of a bone strongly depend on its density, but also on the tissue structure. In addition to genetic factors, the density and the structure are mainly influenced by mechanical loading. Thus, sporting activities or other unusual loads stimulate the formation of bone, while reduced loads lead to bone loss. In addition, age, the availability of nutrients and hormones, as well as the tissue structure type influence the evolution of bone density. This work describes a computational model that most effectively accounts for various aspects of bone remodelling processes as well as bone healing. The macroscopic model presented is based on the theory of continuum mechanics and thermodynamics of open systems and is implemented within the framework of finite element methods. In analysis, the models show an effective behaviour, but also wide applicability. To model the irregular structure of cancellous bone in more detail, a mesoscopic approach is presented representing the adaptation of trabeculae to the dominant loading. By coupling the two approaches, a two-scale model is created. In this, the constitutive behaviour at the macroscopic level is derived by homogenisation of the mesoscopic structure, thus also taking into account the anisotropic behaviour of bone. In summary, the model predictions are in qualitative agreement with observations from biology and medicine. However, quantitative validation requires large clinical data sets such as radiographs and CT, which are scarce due to ethical and health concerns. Nevertheless, because of its efficiency and ease of extension, the model has the potential to be applied for general and patient-specific predictions. Thus, treatment methods could be improved and fracture risks reduced by early countermeasures.Knochen ist ein lebendes Gewebe, welches sich stets verändert. Wie stabil ein Knochen ist, und wie hoch das Frakturrisiko ist, hängt stark von seiner Dichte, aber auch von der Gewebestruktur ab. Neben genetischen Faktoren werden diese vor allem durch mechanische Belastung beeinflusst. Sportliche Betätigung oder anderweitig außergewöhnliche Belastung stimulieren den Knochendichteaufbau, wohingegen reduzierte Belastung Knochenabbau zur Folge hat. Des Weiteren beeinflussen das Alter, die Verfügbarkeit von Nährstoffen und Hormonen, sowie der Gewebestrukturtyp die Entwicklung der Knochendichte. Diese Arbeit beschreibt ein computergestütztes Modell, welches möglichst effektiv unterschiedliche Aspekte der Knochenumbauprozesse wie auch die Heilung von Knochen beinhaltet. Das makroskopische Modell basiert auf der Theorie der Kontinuumsmechanik und der Thermodynamik offener Systeme und ist im Rahmen der Finiten Element Methode implementiert. Die Modelle zeigen in der Analyse ein effektives Verhalten aber auch eine breite Anwendbarkeit. Um die unregelmäßige Struktur der Spongiosa detaillierter zu modellieren, wird außerdem ein Ansatz auf Mesoskopischer Skala vorgestellt, welches die Anpassung der Trabekel auf die dominante Belastung widerspiegelt. Durch Kopplung der beiden Ansätze entsteht ein Multiskalenmodell. In diesem wird das konstitutive Verhalten auf makroskopischer Ebene durch Homogenisierung der mesoskopischen Strukturen abgeleitet und somit auch das anisotrope Verhalten des Knochens berücksichtigt. Die Vorhersagen der Modelle stimmen qualitativ mit Beobachtungen aus der Biologie und Medizin überein. Für eine quantitative Validierung sind jedoch große klinische Datensätze wie Röntgenaufnahmen und CT-Bilder notwendig, welche aufgrund ethischer und gesundheitlicher Bedenken rar verfügbar sind. Nichtsdestotrotz hat das Modell Potential, aufgrund seiner Effizienz und seiner einfachen Erweiterbarkeit sowohl für generelle als auch patientenspezifische Prognosen verwendet zu werden. Somit könnten Behandlungsmethoden verbessert und Frakturrisiken durch frühzeitige Gegenmaßnahmen verringert werden

Praktische Philosophie und Unternehmensethik: Weisheit und Wirtschaft; konstruktiver Dialog oder Kategorienfehler?

"The idea of a philosophical view to open new economic perspectives on values and social responsibility creates new possibilities within the debate about ethical standards in the context of companies and organizations. Through defining and describing the structures of thinking and communicating in economic systems and especially in complex situations of change, a philosophical dialogue helps to clear the real situation and the real possibilities of acting - in an ethical and responsible way: authentic and open minded." (author's abstract

A web-based intervention for carers of individuals with anorexia nervosa (We Can): trial protocol of a randomised controlled trial investigating the effectiveness of different levels of support

Background Anorexia nervosa (AN) is a life-threatening mental disorder that is associated with substantial caregiver burden. Carers of individuals with AN report high levels of distress and self-blame, and insufficient knowledge to help their loved ones. However, carers can have a very important role to play in aiding recovery from AN, and are often highly motivated to assist in the treatment process. This manuscript presents the protocol for a randomised controlled trial (RCT) of We Can, a web-based intervention for carers for people with AN. The study aims to investigate the effectiveness of We Can delivered with different intensities of support. Methods The study takes the form of a multi-site, two-country, three group RCT, comparing We Can (a) with clinician messaging support (We Can-Ind), (b) with moderated carer chatroom support (We Can-Chat) and (c) with online forum only (We Can-Forum). Participants will be 303 carers of individuals with AN as well as, where possible, the individuals with AN themselves. Recruitment will be via specialist eating disorder services and carer support services in the UK and Germany. Randomisation of carers to one of the three intervention conditions in a 1:1:1 ratio will be stratified by whether or not the individual with AN has (a) agreed to participate in the study and (b) is a current inpatient. The We Can intervention will be provided to carers online over a period of 12 weeks. Participants will complete self-report questionnaires at pre-intervention (T1), mid-intervention (mediators only; 4-weeks post-randomisation), post-intervention (T2; 3-months post randomisation), and 6 months (T3) and 12 months (T4) after randomisation. The primary outcome variables are carer symptoms of depression and anxiety. Secondary outcome variables will be measured in both carers and individuals with AN. Secondary carer outcome variables will include alcohol and drug use and quality of life, caregiving behaviour, and the acceptability and use of We Can and associated supports. Secondary outcomes measured in individuals with AN will include eating disorder symptoms, and symptoms of depression and anxiety. The study will also evaluate the cost-effectiveness of the three We Can conditions, and test for mediators and moderators of the effects of We Can. The trial is registered at the International Standard Randomisation Controlled Trial Number (ISRCTN) database, registration number: ISRCTN11399850. Discussion The study will provide insight into the effectiveness of We Can and its optimal method/s of delivery

Higher frequencies of BCRP+ cardiac resident cells in ischaemic human myocardium

Aims Several cardiac resident progenitor cell types have been reported for the adult mammalian heart. Here we characterize their frequencies and distribution pattern in non-ischaemic human myocardial tissue and after ischaemic events. Methods and results We obtained 55 biopsy samples from human atria and ventricles and used immunohistological analysis to investigate two cardiac cell types, characterized by the expression of breast cancer resistance protein (BCRP)/ABCG2 [for side population (SP) cells] or c-kit. Highest frequencies of BCRP+ cells were detected in the ischaemic right atria with a median of 5.40% (range: 2.48-11.1%) vs. 4.40% (1.79-7.75%) in the non-ischaemic right atria (P = 0.47). Significantly higher amounts were identified in ischaemic compared with non-ischaemic ventricles, viz. 5.44% (3.24-9.30%) vs. 0.74% (0-5.23%) (P = 0.016). Few numbers of BCRP+ cells co-expressed the cardiac markers titin, sarcomeric α-actinin, or Nkx2.5; no co-expression of BCRP and progenitor cell marker Sca-1 or pluripotency markers Oct-3/4, SSEA-3, and SSEA-4 was detected. C-kit+ cells displayed higher frequencies in ischaemic (ratio: 1:25 000 ± 2500 of cell counts) vs. non-ischaemic myocardium (1:105 000 ± 43 000). Breast cancer resistance protein+/c-kit+ cells were not identified. Following in vitro differentiation, BCRP+ cells isolated from human heart biopsy samples (n = 6) showed expression of cardiac troponin T and α-myosin heavy-chain, but no full differentiation into functional beating cardiomyocytes was observed. Conclusion We were able to demonstrate that BCRP+/CD31− cells are more abundant in the heart than their c-kit+ counterparts. In the non-ischaemic hearts, they are preferentially located in the atria. Following ischaemia, their numbers are elevated significantly. Our data might provide a valuable snapshot at potential progenitor cells after acute ischaemia in vivo, and mapping of these easily accessible cells may influence future cell therapeutic strategie

The Metagenome-Derived Enzymes LipS and LipT Increase the Diversity of Known Lipases

Triacylglycerol lipases (EC 3.1.1.3) catalyze both hydrolysis and synthesis reactions with a broad spectrum of substrates rendering them especially suitable for many biotechnological applications. Most lipases used today originate from mesophilic organisms and are susceptible to thermal denaturation whereas only few possess high thermotolerance. Here, we report on the identification and characterization of two novel thermostable bacterial lipases identified by functional metagenomic screenings. Metagenomic libraries were constructed from enrichment cultures maintained at 65 to 75°C and screened resulting in the identification of initially 10 clones with lipolytic activities. Subsequently, two ORFs were identified encoding lipases, LipS and LipT. Comparative sequence analyses suggested that both enzymes are members of novel lipase families. LipS is a 30.2 kDa protein and revealed a half-life of 48 h at 70°C. The lipT gene encoded for a multimeric enzyme with a half-life of 3 h at 70°C. LipS had an optimum temperature at 70°C and LipT at 75°C. Both enzymes catalyzed hydrolysis of long-chain (C12 and C14) fatty acid esters and additionally hydrolyzed a number of industry-relevant substrates. LipS was highly specific for (R)-ibuprofen-phenyl ester with an enantiomeric excess (ee) of 99%. Furthermore, LipS was able to synthesize 1-propyl laurate and 1-tetradecyl myristate at 70°C with rates similar to those of the lipase CalB from Candida antarctica. LipS represents the first example of a thermostable metagenome-derived lipase with significant synthesis activities. Its X-ray structure was solved with a resolution of 1.99 Å revealing an unusually compact lid structure

A cellular-meso-macro three-scale approach captures remodelling of cancellous bone in health and disease

Remodelling of cancellous bone due to the combined activity of osteoclasts and osteoblasts at the cellular scale has notable repercussions both at the meso (tissue) as well as the macro (organ) scale. At the meso scale, trabeculae adapt their geometry, typically in terms of their cross section, whereas the nominal bone density evolves at the macro scale, all in response to habitual mechanical loading and its perturbations. To capture this intricate scale coupling, we here propose a novel conceptual three-scale approach to the remodelling of cancellous bone. Therein, we combine a detailed bone cell population model at the cellular scale with an idealised trabecular truss network model with adaptive cross sections, that are driven by the cell population model, at the meso scale, which is eventually upscaled to a continuum bone density adaption model at the macro scale. Algorithmically, we solve the meso and macro problems concurrently within a finite element setting and update the cell activity in a staggered fashion. Our benchmark simulations demonstrate the applicability and effectivity of the three-scale approach to analyse bone remodelling in health and disease (here exemplified for the example of osteoporosis) with rich details, e.g. evolving anisotropy, resolved at each scale.Open Access funding enabled and organized by Projekt DEAL.Bayerische Forschungsallianzhttp://dx.doi.org/10.13039/501100011906Deutsche Forschungsgemeinschafthttp://dx.doi.org/10.13039/501100001659Technische Hochschule Nürnberg (3347