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Pigments are intensely coloured compounds used in many industries to colour other materials. The demand for naturally synthesised pigments is increasing and their production can be incorporated into circular bioeconomy approaches. Natural pigments are produced by bacteria, cyanobacteria, microalgae, macroalgae, plants and animals. There is a huge unexplored biodiversity of prokaryotic cyanobacteria which are microscopic phototrophic microorganisms that have the ability to capture solar energy and CO

Studierende treffen häufig auf Lernformen, die als Gruppenarbeiten organisiert sind. Nur ein adäquater Umgang mit dabei entstehenden Schwierigkeiten kann dazu beitragen, dass Studierende diese Arbeitsform zum Erfolg führen. Allerdings ist dies selten Gegenstand des Studiums. Hier werden Möglichkeiten aufgezeigt, mit den Schwierigkeiten umzugehen.

Agriculture has radically changed the global nitrogen (N) cycle and is heavily dependent on synthetic N-fertiliser. However, the N-use efficiency of synthetic fertilisers is often only 50% with N-losses from crop systems polluting the biosphere, hydrosphere and atmosphere. To address the large carbon and energy footprint of N-fertiliser synthesis and curb N-pollution, new technologies are required to deliver enhanced energy efficiency, decarbonisation and a circular nutrient economy. Algae fertilisers (AF) are an alternative to synthetic N-fertiliser (SF). Here microalgae were used as biofertiliser for spinach production. AF production was evaluated using life-cycle analyses. Over 4 weeks, AF released 63.5% of N as bioavailable ammonium and nitrate, and 25% of phosphorous (P) as phosphate to the growth substrate; SF released 100% N and 20% P. To maximise crop N-use and minimise N-leaching, we explored AF and SF dose-response-curves with spinach in glasshouse conditions. AF-grown spinach produced 36% less biomass than SF-grown plants due to AF's slower and linear N-release; SF exhibited 5-times higher N-leaching than AF. Optimised AF:SF blends yielded greater synchrony between N-release and crop-uptake, boosting crop yields and minimising N-loss. Additional benefits of AF included greener leaves, lower leaf nitrate concentration, and higher microbial diversity and water holding capacity of the growth substrate. An integrated techno-economic and life-cycle-analysis of scaled-up microalgae systems (+/− wastewater) normalised to the application dose showed that replacing the most effective SF-dose with AF lowered the annual carbon footprint of fertiliser production from 3.644 kg CO2 m−2 (C-producing) to −6.039 kg CO2 m−2 (C-assimilation). N-loss from growth substrate was lowered by 54%. Embodied energy for AF:SF blends could be reduced by 29% when cultivating microalgae on wastewater. Conclusions: (i) microalgae offer a sustainable alternative to synthetic N-fertiliser for spinach production and potentially other crop systems, (ii) microalgae biofertilisers support the circular-nutrient-economy and several UN-Sustainable-Development-Goals.

Microalgae biotechnologies are rapidly developing into new commercial settings. Several high value products already exist on the market, and systems development is focused on cost reduction to open up future economic opportunities for food, fuel and freshwater production. Light is a key environmental driver for photosynthesis and optimising light capture is therefore critical for low cost, high efficiency systems. Here a novel high-throughput screen that simulates fluctuating light regimes in mass cultures is presented. The data was used to model photosynthetic efficiency (PEµ, mol photon−1 m2) and chlorophyll fluorescence of two green algae, Chlamydomonas reinhardtii and Chlorella sp. Response surface methodology defined the effect of three key variables: density factor (Df, ‘culture density’), cycle time (tc, ‘mixing rate’), and maximum incident irradiance (Imax). Both species exhibited a large rise in PEµ with decreasing Imax and a minimal effect of tc (between 3–20 s). However, the optimal Df of 0.4 for Chlamydomonas and 0.8 for Chlorella suggested strong preferences for dilute and dense cultures respectively. Chlorella had a two-fold higher optimised PEµ than Chlamydomonas, despite its higher light sensitivity. These results demonstrate species-specific light preferences within the green algae clade. Our high-throughput screen enables rapid strain selection and process optimisation.

Zusammenfassung Banken sind mit der 5. MaRisk-Novelle 2017 zur Schaffung einer angemessenen Risikokultur verpflichtet. Sowohl in der Literatur als auch durch die BaFin wird dabei auf die Rolle von Führung aufmerksam gemacht. Allerdings wurde bislang kaum betrachtet, wie eine entsprechende Führung aussehen muss. Hier wird aufgezeigt, dass gerade transformationale Führung einen Beitrag zur Förderung einer Risikokultur leistet. Diese Form der Mitarbeiterführung fördert die Verantwortlichkeit der Mitarbeiter für die Identifikation, Bewertung und Steuerung von Risiken aus Gesamtinstitutssicht und schafft es, dieses Wissen für das Unternehmen zugänglich und nutzbar zu machen.

Efficient photosynthetic biomass production in a high rate pond (HRP) or a photobioreactor (PBR) represents the first step of microalgae platforms for the production of renewable fuels, animal feeds and a diverse range of high value products. This study analyses the interplay between solar energy input, ambient temperature and system surface area to volume (SA:V) ratio in terms of photosynthetic performance (yield, areal and volumetric productivity, photon conversion efficiency). Ten pilot scale trials were conducted under subtropical conditions using 2 microalgae strains (Chlorella sorokiniana and Chlorella sp.) in 5 different cultivation system geometries: HRPs, flat panel PBRs (0.75 m and 1.5 m high) and tubular PBRs (0.74 m and 1.49 m high). The evaluation of culture temperature and biomass productivity response to solar irradiance in the five production systems suggests that the optimal SA:V ratio range lies between 43–73 m2 m− 3 for C. sorokiniana in non-cooled systems regardless of system geometry under the conditions tested. The overall photosynthetic performance at higher SA:V ratios was improved for Chlorella sp. using temperature regulation. The highest observed daily photon conversion efficiency (PCE) was 4.44% (based on illuminated PBR surface area and total solar spectrum) in the high flat panel PBR using C. sorokiniana (40.8 g m− 2 d− 1, 0.23 g L− 1 d− 1). The highest achieved mean PCE (based on illuminated PBR surface area and total solar spectrum) was 2.5% in the low tubular PBR with Chlorella sp. (24.9 g m− 2 d− 1, 0.43 g L− 1 d− 1). The trial data provides important design principles to help fast track systems optimisation for near optimal sub-tropical conditions.

Microalgae provide a powerful solar driven biotechnology platform for the production of the increasing quantity of food, fuel, high value products, fine chemicals and clean water required to supply our expanding global population. Light capture fuels all photosynthetically driven microalgae processes and consequently, maximizing light capture efficiency at minimal cost is central to process design. Raceway-style and paddle wheel operated open ponds, also known as high rate ponds (HRP0), are widely used, easy to operate and offer low-cost evaporative cooling compared to energy intensive closed systems. Here, the concept of delivering light from the surface into greater depths of the algae solution was tested at pilot-scale, by fitting a standard HRP0 with light transmitting guides designed to allow the capture of sunlight between ~10:00 am and ~3:00 pm to improve light distribution throughout the depth of the solution (HRP+). This prototype (HRP+) was analyzed to compare light distribution and biomass production efficiency against two control systems in two separate experiments such as: 1) a standard High Rate Pond (HRP0), and 2) a standard HRP0 fitted with no light transmitting dummy guides (HRP-) to maintain comparable fluid dynamics system characteristics. Under semi-continuous cultivation, HRP+ showed a significantly improved light distribution within the culture compared to the HRP- when operated at moderate to high densities. An increased proportion of the culture in the HRP+ was kept within the desired optimal photosynthetic zones while dark zones (unfit for photosynthesis and causing biomass loss) were drastically reduced compared to the HRP-. The HRP+ system exhibited a 3.9-fold higher maximum areal productivity of 49.2 ± 8.3 g·m−2·d−1 compared to HRP- (March–April 2018). Overall, this study establishes proof-of-concept of the functionality of light guides to improve light distribution and productivities in microalgae cultivation systems compared to the control systems run at the same incident light levels.

Dewatering is one of the major constraints to the large scale production of microalgae biofuels, with many drawbacks in currently deployed technologies. Using an approach similar to papermaking, cationic polyacrylamide (CPAM) based flocculants can stabilize flocs of microalgae under turbulent conditions to achieve effective dewatering of dilute suspensions in high speed filtration systems. The effects of flocculant dosage, stirrer speed (i.e. turbulence) and pH on filtration retention was investigated using a Britt Dynamic Drainage Jar (BDDJ) which simulates a commercial paper machine. The development of a stable floc system that withstood turbulence was achieved through the flocculant’s dual effects of charge neutralization and bridging of the microalgae cells. Retention of microalgae on a 76 µm screen improved from 7% when no flocculant was used to 94% at a flocculant dosage of 10 mg/L of CPAM, stirrer speed of 1200 rpm and pH of 6.5 as optimum conditions. The most significant effects on microalgae retention were that of flocculant dosage; followed by the combined interaction between stirrer speed and flocculant dosage; and that of pH. A key finding is that high retention was obtained under moderately turbulent conditions. This study shows that the paper dewatering technique will be potentially applicable for microalgae preconcentration in the production of biofuels, and further pilot scale studies are recommended.

Access to affordable and clean energy is a United Nations' Sustainable Development Goal. The prospects for cheap, reliable, renewable stationary energy and electric vehicles have rapidly improved, driven by de‑carbonisation and sustainability agendas, enhanced policy interventions and maturing technology options. In contrast, low-carbon renewable liquid fuel production systems remain critically underdeveloped amid market-distorting subsidies to fossil fuels. Advanced microalgae-based systems can deliver renewable fuels essential to meet United Nations Framework Convention on Climate Change COP 21 commitments. Here we use TELCA, an integrated triple-bottom-line Techno-Economic and Life-Cycle Analysis platform (economic - $·L−1 diesel, social – ERoEI MJ·MJ−1, environmental - GHG emissions g CO2·MJ−1), to define the role that key technology advances and policy settings can play in driving down the price of renewable microalgae-based diesel from US$11.11 gal−1 (US$2.93 L−1) to a point of cost competitiveness with fossil-based diesel US$3.00 gal−1 (US$0.79 L−1). This price reduction could be attained while simultaneously achieving an ERoEI of 4.1 and limiting GHG emissions to 21 g CO2-e MJ−1. Importantly, TELCA allows different jurisdictions to competitively adjust their policy settings to attract an expanding microalgae-based renewable fuel industry (case-study provided).

Microalgae provide a powerful biotechnology platform for the production of renewable fuels, animal-feeds and high-value products. Here, a newhigh-throughput nutrient optimisation screen was used to maximise photoautotrophic growth rates for 100 newly bio-prospectedmicroalgae isolates. The multidimensional statistical design enabled the optimisation of 12 critical nutrients (N, P, Ca, Mg, Fe, Cu, Mn, Zn, B, Se, V and Si) and identified the highest specific-growth rates, elemental main-effects (Ca, Mg and Zn accounted for 71% of all main effects under photoautotrophic conditions) and pair-wise nutrient interactions (e.g. Ca-Mg, Mg-Zn, B-Zn, B-Se, Mn-Zn and Zn-Si) for each of the 100 strains tested (25,100 trials, over 2000-fold data-compression compared to a full factorial design) as well as their ability to use different carbon sources. Photoautotrophic growth rates reaching 0.067 h(-1) (0.289 h(-1) at microwell plate scale) and 2.78 g L-1 (batch cultivation in flasks) are amongst the highest reported, promoting the capacity for a high-throughput optimisation of microalgae production processes using established and newly bio-prospected strains. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.

The immune system undergoes profound age-related changes, including a gradual increase in the production and circulation of proinflammatory cytokines. Despite the known capacity of fibroblasts to produce cytokines, little is known so far about the inflammatory response of fibroblasts to cellular stress such as viral and/or bacterial infection in the context of aging. Therefore the aim of this study was to analyze the levels of IL6 and IL8 secretion in supernatants of human skin fibroblasts from young and elderly persons. Cytokine and chemokine secretion was analyzed before and after in vitro infection of the cells with Cytomegalovirus (CMV) and/or stimulation with Lipopolysaccharide (LPS). The exposure of fibroblasts to these agents caused inflammatory changes, reflected by the secretion of both the cytokine IL6 and the chemokine IL8 by fibroblasts from young as well as elderly persons. The cytokine/chemokine production induced by either agent alone could be further increased by co-stimulation of the cells with both stimuli. The level of protein secretion was dependent on the chronological age of the fibroblasts. Stimulated human skin fibroblasts from elderly donors produced higher amounts of IL6 as well as IL8 than fibroblasts from young donors. These differences were more pronounced for IL6 than for IL8. The inflammatory response of fibroblasts to stimulation differed among donors and did not correspond to the responsiveness of whole blood derived from the same person. In summary lifelong CMV-infection may act as an in vivo trigger for inflammatory changes by increasing the inflammatory response to bacterial products such as LPS. It may thus contribute to age-related inflammatory processes, referred to as ‘inflamm-aging’., Highlights ► CMV and LPS induced cytokine production of skin fibroblasts depends on donor age. ► Stimulated fibroblasts from elderly donors produce higher amounts of IL6 and IL8. ► CMV-infection can increase the inflammatory response to bacterial products (LPS). ► The inflammatory response to LPS stimulation is different in individual cell types.

The immune system is affected by the aging process and undergoes significant age-related changes, termed immunosenescence. Different T cell subsets are affected by this process. Alterations within the bone marrow and thymus lead to a shift in the composition of the T cell repertoire from naïve to antigen-experienced T cells, thereby compromising the diversity of the T cell pool. Additional infection with latent pathogens such as cytomegalovirus aggravates this process. In this review, we focus on the major age-related changes that occur in the naïve and the antigen-experienced T cell population. We discuss the mechanisms responsible for the generation and maintenance of these subsets and how age-related changes can be delayed or prevented by clinical interventions.

Future energy solutions are required not only to deliver energy for a rapid growing global population, but also to safeguard the environment, which provides the basis of life on Earth. The Earth receives 3020 ZJ yr-1 of solar energy [1], which dwarfs today’s global energy demand of 0.56 ZJ yr-1 [2] and so even at low solar-to-chemical energy conversion efficiencies solar fuel systems could theoretically supply global fuel demand. Ultimately this theoretical limit will be restricted by practical, economic and socio-political constraints but it is clear that solar energy is by far the most abundant energy source available to us and capable of driving a significant portion of a future renewable fuel industry, be it via artificial solar or solar biofuels systems. Biofuel systems convert solar energy into chemical energy in the form of biomass using photosynthesis. In the biomass the energy is stored in organic molecules including oils, proteins, starch, lignin, and cellulose. Microalgal systems can offer potential advantages such as security of supply through regionally distributed production as well as the generation of useful by-products and the utilisation of waste streams. A detailed literature review is given in chapter 1 discussing the ideas and difficulties of microalgae as an energy technology. Additional background on the requirement and availability of resources for biomass production, the characteristics of microalgae biology and strain optimisation, as well as the challenges of phototrophic mass cultivation and process management are reviewed prior to the relevant research chapter 2, 3 and 4. The optimal production of selected microalgae strains requires the optimisation of nutrients, CO2 levels, light dilution properties, pH and temperature. The development of a powerful automated high-throughput microalgal screening system is described in chapter 2. It is designed to identify improved nutrient conditions for a broad range of species within a complex multi-dimensional statistical space focusing on the optimisation of the 12 most important nutrients in photoautotrophic (light and CO2) conditions. These include macro- (N [i.e. NO3-, NH4+ & urea], P, Ca, Mg) and micro-elements (Mn, Zn, Cu, B, V, Si, Fe, Se) with the remaining ones provided in reportedly replete levels and at 1% CO2 concentrations (adjustable). In chapter 3, 100 microalgae strains (axenic) have been analysed for growth kinetics using the automated nutrient screen matrix (chapter 2). Approximately 600,000 data points were recorded and the optimum photoautotrophic conditions for maximum biomass production for each microalgae strains were statistically defined. Calcium, magnesium and zinc were identified as the most significant nutrients affecting growth at elevated CO2 concentration. The carbon source utilisation was also monitored for mixotrophic and heterotrophic conditions. The 10 best performing strains based on biomass productivity, taxonomic diversity and compositional analysis were then selected as production candidates for validation experiments in flasks. Chapter 3 (and Appendix A) also describes the collection, purification and identification of local microalgae used for the high-throughput nutrient screening. Local strain collections offer significant advantages for a developing microalgae industry by overcoming regulatory aspects (e.g. Quarantine restrictions) and intellectual property restrictions. Local isolates are also often more robust to local climate conditions compared to algal strains from culture collections. More than 100 strains (mostly Chlorophytes) have been purified to the axenic level and about 50% were successfully cryopreserved for long-term storage. The taxonomic identification was initially based on morphological classification and was refined through ribosomal DNA analysis (16S, 18S). The first step of all algae-derived products is the photosynthetic production of biomass, cultivated in ponds or specific photobioreactors (e.g. flat-panel or tubular systems). Chapter 4 compares the performance of a reference (Chlorella sorokiniana (12_A9)) and high productivity microalgae strain Chlorella sp. (11_H5) (two production candidate strains selected based on the analysis in chapter 3) in high-rate-ponds, flat-panel bioreactors (0.75 m and 1.5 m high) and tubular bioreactors (0.74 m and 1.49 m high) under subtropical field conditions. System inputs (light, nutrients, CO2), outputs (biomass, nutrient uptake, O2 and CO2) and population dynamics (micrographs and flow cytometry) were monitored to define key production parameters. The highest observed daily photosynthetic conversion efficiency (PCE) based on illuminated bioreactor surface area was 4.44% in the high flat-panel systems using C. sorokiniana (12_A9) (40.8 g.m-2.d-1, 0.23 g.L-1.d-1). The highest achieved mean PCE (PBR surface based) was 2.5% in the low tubular bioreactor with Chlorella sp. (11_H5) (mean: 24.9 g.m-2.d-1, 0.43 g.L-1.d-1). A correlation was observed for C. sorokiniana (12_A9) between PCE and illuminated surface area to volume (SA:V) ratio in terms of areal productivity. Chlorella sp. (11_H5) appeared to perform better at high light and temperatures.

An advanced understanding of the genetics of microalgae and the availability of molecular biology tools are both critical to the development of advanced strains, which offer efficiency advantages for primary production, and more specifically in the context of production for biocrude and renewable energy. Consequently, we outline the current state of the art in microalgal molecular biology including the available genome sequences, molecular techniques and toolkits, amenable strains for transformation of nuclear and plastid genomes, and the control of transgenes at both transcriptional and translational levels. We also examine some strategies for improvement of expression and regulation. We suggest the primary strategies in strain improvement that are most relevant to biocrude applications; briefly illustrate the process of photosynthesis to enable identification of targets for improvement of net photosynthetic conversion efficiency in mass cultivation; and further discuss how improvement of metabolic systems may also be achieved and benefit production models. Finally, we acknowledge the aspects of prudent risk assessment and consequent regulation that are developing and how our knowledge of natural algae in existing ecosystems, and GM work in conventional agriculture both contribute lessons to these discussions. We conclude that if properly managed, these developments provide significant potential for increasing global capacity for renewable fuel production from microalgae and that these developments could also have benefits for other applications.

Resource limitation is an escalating concern given human expansion and development. Algae are increasingly recognised as a promising bioresource and the range of cultivated species and their products is expanding. Compared to terrestrial crops, microalgae are very biodiverse and offer considerable versatility for a range of biotechnological applications including the production of animal feeds, fuels, high value products and waste-water treatment. Despite their versatility and capacity for high biomass productivity on non-arable land, attempts to harness microalgae for commercial benefit have been limited. This is in large part due to capital costs and energy inputs remaining high, the necessity of identifying ‘suitable’ land with proximal resource and infrastructure availability and the need for process and strain optimisation. Microalgae represent a relatively unexplored bioresource both for native and engineered strains. Success in this area requires (1) appropriate methods to source and isolate microalgae strains, (2) efficient maintenance of motherstocks, (3) rapid strain characterisation and correct matching of strains to applications, (4) ensuring productive and stable cultivation at scale, and (5) ongoing strain development (breeding, adaptation and engineering). This article illustrates a survey and isolation of over 150 local microalgae strains as a bioresource for ongoing strain development and biotechnological applications.

Single cell green algae (microalgae) are rapidly emerging as a platform for the production of sustainable fuels. Solar-driven H2 production from H2O theoretically provides the highest-efficiency route to fuel production in microalgae. This is because the H2-producing hydrogenase (HYDA) is directly coupled to the photosynthetic electron transport chain, thereby eliminating downstream energetic losses associated with the synthesis of carbohydrate and oils (feedstocks for methane, ethanol and oil-based fuels). Here we report the simultaneous knock-down of three light-harvesting complex proteins (LHCMB1, 2 and 3) in the high H2-producing Chlamydomonas reinhardtii mutant Stm6Glc4 using an RNAi triple knock-down strategy. The resultant Stm6Glc4L01 mutant exhibited a light green phenotype, reduced expression of LHCBM1 (20.6% ±0.27%), LHCBM2 (81.2% ±0.037%) and LHCBM3 (41.4% ±0.05%) compared to 100% control levels, and improved light to H2 (180%) and biomass (165%) conversion efficiencies. The improved H2 production efficiency was achieved at increased solar flux densities (450 instead of ∼100 µE m(-2) s(-1)) and high cell densities which are best suited for microalgae production as light is ideally the limiting factor. Our data suggests that the overall improved photon-to-H2 conversion efficiency is due to: 1) reduced loss of absorbed energy by non-photochemical quenching (fluorescence and heat losses) near the photobioreactor surface; 2) improved light distribution in the reactor; 3) reduced photoinhibition; 4) early onset of HYDA expression and 5) reduction of O2-induced inhibition of HYDA. The Stm6Glc4L01 phenotype therefore provides important insights for the development of high-efficiency photobiological H2 production systems.

Background: Biogeochemical elemental cycling is driven by primary production of biomass via phototrophic phytoplankton growth, with 40% of marine productivity being assigned to diatoms. Phytoplankton growth is widely limited by the availability of iron, an essential component of the photosynthetic apparatus. The oceanic diatom Thalassiosira oceanica shows a remarkable tolerance to low-iron conditions and was chosen as a model for deciphering the cellular response upon shortage of this essential micronutrient. Results: The combined efforts in genomics, transcriptomics and proteomics reveal an unexpected metabolic flexibility in response to iron availability for T. oceanica CCMP1005. The complex response comprises cellular retrenchment as well as remodeling of bioenergetic pathways, where the abundance of iron-rich photosynthetic proteins is lowered, whereas iron-rich mitochondrial proteins are preserved. As a consequence of iron deprivation, the photosynthetic machinery undergoes a remodeling to adjust the light energy utilization with the overall decrease in photosynthetic electron transfer complexes. Conclusions: Beneficial adaptations to low-iron environments include strategies to lower the cellular iron requirements and to enhance iron uptake. A novel contribution enhancing iron economy of phototrophic growth is observed with the iron-regulated substitution of three metal-containing fructose-bisphosphate aldolases involved in metabolic conversion of carbohydrates for enzymes that do not contain metals. Further, our data identify candidate components of a high-affinity iron-uptake system, with several of the involved genes and domains originating from duplication events. A high genomic plasticity, as seen from the fraction of genes acquired through horizontal gene transfer, provides the platform for these complex adaptations to a low-iron world. Peer Reviewed publishedVersion

Die Zintl-Phasen M3X11 (M = Na, K, Rb, Cs; X = P, As) werden aus den Elementen oder aus M3X7 und X synthetisiert. Die Verbindungen durchlaufen einen Phasenubergang 1. Ordnung vom kristallinen zum plastisch-kristallinen Zustand. Elementarzelle und Raumgruppe beider Modifikationen sowie Ubergangstemperaturen Tc wurden bestimmt. Die Schwingungsspektren der kristallinen Verbindungen sowie das Raman-Spektrum des Anions P113− in en-Losung wurden gemessen. Die Zuordnung der Schwingungsfrequenzen gelingt auf der Basis der Symmetrie 32-D3 der Kafiganionen X113−. Die Normalkoordinatenanalyse erfolgte in kartesischen Koordinaten, wodurch das in inneren Koordinaten auftretende Redundanzproblem vermieden wird. Auf diesem Wege erhaltene Kraftkonstanten [mdyn A−1] der charakteristischen Bindungen r, s und t sind: f = 1, 34, f = 1, 20, f = 1, 08; f = 1, 1, f = 0, 96, f = 0, 91. Die Normalschwingungen und die Verteilung der potentiellen Energie (PED) werden diskutiert. Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 53. Preparation, Properties, and Vibrational Spectra of the Cage Anions P113− and As113− The Zintl-phases M3X11 (M = Na, K, Rb, Cs; X = P, As) are prepared from the elements or from M3X7 and X. The compounds undergo a first-order phase transition from the crystalline to the plastically crystalline state. Unit cell and space group of both modifications and the transition temperature Tc are determined. The vibrational spectra of the crystalline compounds and the Raman spectrum of the P113− anion in en-solution as well are measured. The assignment of the frequencies is given, based on the 32-D3 symmetry of the X113− cage anion. Normal coordinate analysis is carried out in terms of Cartesian coordinates to avoid the problem of redundancies in using internal coordinates. The force constants [mdyn A−1] obtained for the characteristic bonds r, s, and t are: f = 1.34, f = 1.20, f = 1.08; f = 1.1, f = 0.91. Normal vibrations and the potential energy distribution (PED) are discussed.

Es geht um einen alten Traum: Fahren mit einem Kraftstoff aus Wasser. Keine Abgase, keine Umweltverschmutzung, genugend Energie fur immer und ewig. Dieser alte Traum gewann seit 1992 uberraschend an Aktualitat: Seit der Rio-Konferenz mit ihrer Verpflichtung zu nachhaltigem Handeln ist Wasserstoff als Kraftstoff der Zukunft intensiv ins Gesprach gekommen.

Background As a chronic antigenic stressor human Cytomegalovirus (CMV) contributes substantially to age-related alterations of the immune system. Even though monocytes have the greatest propensity for CMV-infection and seem to be an important host for the virus during latency, fibroblasts are also discussed to be target cells of CMV in vivo. However, little is known so far about general immunoregulatory properties of CMV in fibroblasts. We therefore investigated the immunoregulatory effects of CMV-infection in human lung fibroblasts and the impact on replicative senescence. Findings We observed that CMV-infection led to the induction of several immunoregulatory host cell genes associated with the innate and adaptive immune system. These were genes of different function such as genes regulating apoptosis, cytokines/chemokines and genes that are responsible for the detection of pathogens. Some of the genes upregulated following CMV-infection are also upregulated during cellular senescence, indicating that CMV causes an immunological phenotype in fibroblasts, which is partially reminiscent of replicative senescent cells. Conclusion In summary our results demonstrate that CMV not only affects the T cell pool but also induces inflammatory processes in human fibroblasts.

Purpose. Different opinions regarding the storage conditions of cord blood before cryopreservation exist. Most experts recommend the storage at room temperature and the cyropreservation within the first 24 hours after delivery of the baby. However, the optimum storage temperature is unknown. Methods. Cord blood units (n=46) were stored for 24, 48 and 72 hours at room temperature (RT) and 4°C. After storage, CD34(+) cells were isolated and analyzed for their cell count, flow cytometry profile, apoptosis rate, colony-forming capacity by methylcellulose assays, and transmigration capacity in response to stroma-derived factor 1. If possible, a direct-paired comparison was performed (n=15). Results. The cell count of peripheral blood mononuclear cells was generally 10fold higher in cord blood units stored at RT than in cord blood units stored at 4°C, leading to a 10fold higher number of isolated CD34(+) cells. There was no difference in the frequency of CD34(+) cells after immunomagnetic isolation (>95%) or in the frequency of CD133(+) and CD45(+) cells. At 48 hours, the apoptosis rate was lower at RT than at 4°C (37.7±7.4 vs 49.9±4.2%). The plating efficiencies (PE) were highest after the units had been stored for 48 hours (RT 14.7±3.6%, 4°C 16.3±4%) independent of the storage temperature. The cells stored at RT for 48 hours had the highest transmigration capacity (54±11.9% vs 4°C 10.7±2%). Storage times of 24 and 72 hours resulted in PEs of on average below 10%. CD34(+)cells stored for 24 hours migrated less than the cells stored at 48 hours. Their transmigration capacity showed no temperature-dependent difference (RT 24.6±7.1 vs 4°C 36.1±10.2%). Conclusion. Our data imply that CD34(+) cells from cord-blood units stored for 48 hours at room temperature have the highest plating efficiencies and transmigration capacities. A storage time for 48 hours before cryopreservation seems tolerable, since there was no increase of the apoptosis rate.

Rb2SiAs2 was found as a byproduct in the course of the RbAs synthesis in a quartz container. The direct synthesis from the elements yields pure samples w-ithin 5 h at 925 K. Rb2SiAs2 forms transparent red needle-shaped crystals which split to bunches of golden, reflecting fibres. The compound is sensitive against moisture. Rb2SiAs2 is isotypic to K2SiP2 with a polyanionic chain [SiAs2]2- of edge-connected tetrahedra (isostructural and isoelectronic to SiS2) formed in a dis­torted cubic closed packed As arrangement, and with Rb in the octahedral holes (Ibam. No. 72; a = 726.6(5), b = 1377.1(6), c = 638.9(3) pm; Z = 4: Si−As = 238.1 pm; As−Si−As = 95.7° and Si−As−Si = 84.3° in the four membered Si2As2 rings).

The heptaarsanes(3) As7(Mme3)3 (M = Si, Ge, Sn) with nortricyclene structure have been synthesized by heterogeneous and homogeneous reactions from K3As7 and Rb3As7, respectively, with Mme3Cl. The crystal structures have been determined. The compounds are isotypic and crystallize in unit cells of R3̄̄ symmetry, containing pairs of enantiomers. The bond lengths d(As-As) in the nortricyclene skeleton are nearly uneffected by the substituents and show the sequence typical for covalent nortricyclenes: d(basal) = 244.3 pm > d(basal-equatorial) = 242.7 pm > d(equatorial-apical) = 240.7 pm (mean values). The spread-off of the Mme, substituents decreases as going from P7 to As7 skeletons as well as with increasing size of M