Simulation of metal quenching processes for the minimization of distortion and stresses

Quenching process, TRIP, J2-plasticity theory, phase transition, distortion

Influence of water quality and kind of metal in the secondary cooling zone of casting process

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2012

Growth of semi-polar GaN on high index silicon (11h) substrates by metal organic vapor phase epitaxy

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2014

Cytochemical characterization of gill and hepatopancreatic cells of the crab Ucides cordatus (Crustacea, Brachyura) validated by cell metal transport

Ucides cordatus (Linnaeus, 1763) is a hypo-hyper-regulating mangrove crab possessing gills for respiratory and osmoregulatory processes, separated in anterior and posterior sections. They also have hepatopancreas, which is responsible for digestion and absorption of nutrients and detoxification of toxic metals. Each of these organs has specific cells that are important for in vitro studies in cell biology, ion and toxic metals transport. In order to study and characterize cells from gills and hepatopancreas, both were separated using a Sucrose Gradient (SG) from 10 to 40% and cells in each gradient were characterized using the vital mitochondrial dye DASPEI (2-(4-dimethylaminostyryl)-N- ethylpyridinium iodide) and Trichrome Mallory's stain. Both in 20 and 40% SG for gill cells and 30% SG for hepatopancreatic cells, a greater number of cells were colored with DASPEI, indicating a larger number of mitochondria in these cells. It is concluded that the gill cells present in 20% and 40% SG are Thin cells, responsible for respiratory processes and Ionocytes responsible for ion transport, respectively. For hepatopancreatic cells, the 30% SG is composed of Fibrillar cells that possess larger number of membrane ion and nutrient transporters. Moreover, the transport of toxic metal cadmium (Cd) by isolated hepatopancreatic cells was performed as a way of following cell physiological integrity after cell separation and to study differences in transport among the cells. All hepatopancreatic cells were able to transport Cd. These findings are the first step for further work on isolated cells of these important exchange epithelia of crabs, using a simple separation method and to further develop successful in vitro cell culture in crabs.

Expression of a plant-derived peptide harboring water-cleaning and antimicrobial activities.

Drinking water is currently a scarce world resource, the preparation of which requires complex treatments that include clarification of suspended particles and disinfection. Seed extracts of Moringa oleifera Lam., a tropical tree, have been proposed as an environment-friendly alternative, due to their traditional use for the clarification of drinking water. However, the precise nature of the active components of the extract and whether they may be produced in recombinant form are unknown. Here we show that recombinant or synthetic forms of a cationic seed polypeptide mediate efficient sedimentation of suspended mineral particles and bacteria. Unexpectedly, the polypeptide was also found to possesses a bactericidal activity capable of disinfecting heavily contaminated water. Furthermore, the polypeptide has been shown to efficiently kill several pathogenic bacteria, including antibiotic-resistant isolates of Staphylococcus, Streptococcus, and Legionella species. Thus, this polypeptide displays the unprecedented feature of combining water purification and disinfectant properties. Identification of an active principle derived from the seed extracts points to a range of potential for drinking water treatment or skin and mucosal disinfection in clinical settings.

Target-guided synthesis of metal-based phosphatase inhibitors

Report for the scientific sojourn at the Imperial College of London, United Kingdom, from 2007 to 2009. PTEN is a tumour suppressor enzyme that plays important roles in the PI3K pathway which regulates growth, proliferation and survival and is thus related to many human disorders such as diabetes, neurodegenerative diseases, cardiovascular complications and cancer. It is hence of great interest to understand in detail its molecular behaviour and to find small molecules that can switch on/off its activity. For this purpose, metal complexes have been synthesized and preliminary studies in vivo show that all are capable of inhibiting PTEN.

Hand cleaning technique

This reversible poster is part of an extension of the cleanyourhands campaign, aimed at preventing the spread of healthcare associated infections (HCAIs) in community healthcare settings including primary care and dental services, residential and nursing homes (including independent sector homes), hospices and independent clinics/hospitals. It is designed for pump dispenser or handwashing areas to heighten awareness of protecting patients from avoidable infections by cleaning of hands using proper techniques.

Cleaning up neighbourhoods - Environmental Problems and Service Provision in Deprived areas

There has been growing concern that the quality of public services can be affected by the nature and scale of problems in deprived neighbourhoods and that poor services can contribute to a widening gap۪ between deprived and non-deprived neighbourhoods. There is also an increased emphasis within national policy on the quality of neighbourhood environments the so-called liveability۪ agenda. This report explores the challenges of delivering street scene۪ environmental services such as street sweeping and refuse collection in deprived and less deprived areas and examines the gap in environmental amenity between these different neighbourhoods. It also contributes to our understanding of the interplay between poor services and neighbourhood decline. The research involved a telephone survey of chief officers in local authority environmental service departments across the UK and detailed case studies of policy and practice in environmental service provision in four local authorities with significant levels of deprivation. Each case study involved work in three neighbourhoods within the authority two deprived and one less deprived as well as focus groups with residents and frontline environmental operatives, interviews with senior council staff and observation on the ground

Full Exploration of the Diels–Alder Cycloaddition on Metallofullerenes M3N@C80 (M=Sc, Lu, Gd): The D5h versus Ih Isomer and the Influence of the Metal Cluster

In this work a detailed investigation of the exohedral reactivity of the most important and abundant endohedral metallofullerene (EMF) is provided, that is, Sc3N@Ih-C80 and its D5h counterpart Sc3N@D5h-C80, and the (bio)chemically relevant lutetium- and gadolinium-based M3N@Ih/D5h-C80 EMFs (M=Sc, Lu, Gd). In particular, we analyze the thermodynamics and kinetics of the Diels–Alder cycloaddition of s-cis-1,3-butadiene on all the different bonds of the Ih-C80 and D5h-C80 cages and their endohedral derivatives. First, we discuss the thermodynamic and kinetic aspects of the cycloaddition reaction on the hollow fullerenes and the two isomers of Sc3N@C80. Afterwards, the effect of the nature of the metal nitride is analyzed in detail. In general, our BP86/TZP//BP86/DZP calculations indicate that [5,6] bonds are more reactive than [6,6] bonds for the two isomers. The [5,6] bond D5h-b, which is the most similar to the unique [5,6] bond type in the icosahedral cage, Ih-a, is the most reactive bond in M3N@D5h-C80 regardless of M. Sc3N@C80 and Lu3N@C80 give similar results; the regioselectivity is, however, significantly reduced for the larger and more electropositive M=Gd, as previously found in similar metallofullerenes. Calculations also show that the D5h isomer is more reactive from the kinetic point of view than the Ih one in all cases which is in good agreement with experiments

Cleaning wrasse species vary with respect to dependency on the mutualism and behavioural adaptations in interactions

Interspecific mutualisms are an essential feature of life on earth, yet we know little about their evolution and stability. In many mutualisms several species are available as partners, raising questions about the similarity in function and behavioural repertoire depending on the partner species. Furthermore, variation between species in the quantity and quality of interactions resulting in variation in payoffs may allow us to infer the potential evolutionary origin of a multispecies mutualism complex. We addressed these issues in the marine cleaning mutualism, in which so-called 'cleaners' remove ectoparasites from so-called 'client' reef fish. We measured several parameters concerning the quantity and quality of cleaning interactions in six sympatric cleaner wrasse species. We found significant variation between cleaner species with respect to client diversity, the number of interactions with predatory clients, the duration of interactions, the frequency of client jolts as a correlate of 'cheating' by cleaners, and behaviours used for manipulation of client decisions. Exploratory correlations between cleaner species' dependency and our variables of interest suggest that cleaning originated as a conflict-free by-product mutualism and evolved towards more sophisticated behaviours, including strategic behaviours for interactions with predators, cheating and manipulation specifically adapted to the client type.

Optimization of floor cleaning coverage performance of a random path-planning mobile robot

Floor cleaning is a typical robot application. There are several mobile robots aviable in the market for domestic applications most of them with random path-planning algorithms. In this paper we study the cleaning coverage performances of a random path-planning mobile robot and propose an optimized control algorithm, some methods to estimate the are of the room, the evolution of the cleaning and the time needed for complete coverage.

Practical considerations for conducting ecotoxicity test methods with manufactured nanomaterials: what have we learnt so far?

This review paper reports the consensus of a technical workshop hosted by the European network, NanoImpactNet (NIN). The workshop aimed to review the collective experience of working at the bench with manufactured nanomaterials (MNMs), and to recommend modifications to existing experimental methods and OECD protocols. Current procedures for cleaning glassware are appropriate for most MNMs, although interference with electrodes may occur. Maintaining exposure is more difficult with MNMs compared to conventional chemicals. A metal salt control is recommended for experiments with metallic MNMs that may release free metal ions. Dispersing agents should be avoided, but if they must be used, then natural or synthetic dispersing agents are possible, and dispersion controls essential. Time constraints and technology gaps indicate that full characterisation of test media during ecotoxicity tests is currently not practical. Details of electron microscopy, dark-field microscopy, a range of spectroscopic methods (EDX, XRD, XANES, EXAFS), light scattering techniques (DLS, SLS) and chromatography are discussed. The development of user-friendly software to predict particle behaviour in test media according to DLVO theory is in progress, and simple optical methods are available to estimate the settling behaviour of suspensions during experiments. However, for soil matrices such simple approaches may not be applicable. Alternatively, a Critical Body Residue approach may be taken in which body concentrations in organisms are related to effects, and toxicity thresholds derived. For microbial assays, the cell wall is a formidable barrier to MNMs and end points that rely on the test substance penetrating the cell may be insensitive. Instead assays based on the cell envelope should be developed for MNMs. In algal growth tests, the abiotic factors that promote particle aggregation in the media (e.g. ionic strength) are also important in providing nutrients, and manipulation of the media to control the dispersion may also inhibit growth. Controls to quantify shading effects, and precise details of lighting regimes, shaking or mixing should be reported in algal tests. Photosynthesis may be more sensitive than traditional growth end points for algae and plants. Tests with invertebrates should consider non-chemical toxicity from particle adherence to the organisms. The use of semi-static exposure methods with fish can reduce the logistical issues of waste water disposal and facilitate aspects of animal husbandry relevant to MMNs. There are concerns that the existing bioaccumulation tests are conceptually flawed for MNMs and that new test(s) are required. In vitro testing strategies, as exemplified by genotoxicity assays, can be modified for MNMs, but the risk of false negatives in some assays is highlighted. In conclusion, most protocols will require some modifications and recommendations are made to aid the researcher at the bench. [Authors]