80 research outputs found

    The Effect of Diel Temperature and Light Cycles on the Growth of Nannochloropsis oculata in a Photobioreactor Matrix

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    A matrix of photobioreactors integrated with metabolic sensors was used to examine the combined impact of light and temperature variations on the growth and physiology of the biofuel candidate microalgal species Nannochloropsis oculata. The experiments were performed with algal cultures maintained at a constant 20u C versus a 15°C to 25°C diel temperature cycle, where light intensity also followed a diel cycle with a maximum irradiance of 1920 Όmol photons m-2 s-1. No differences in algal growth (Chlorophyll a) were found between the two environmental regimes; however, the metabolic processes responded differently throughout the day to the change in environmental conditions. The variable temperature treatment resulted in greater damage to photosystem II due to the combined effect of strong light and high temperature. Cellular functions responded differently to conditions before midday as opposed to the afternoon, leading to strong hysteresis in dissolved oxygen concentration, quantum yield of photosystem II and net photosynthesis. Overnight metabolism performed differently, probably as a result of the temperature impact on respiration. Our photobioreactor matrix has produced novel insights into the physiological response of Nannochloropsis oculata to simulated environmental conditions. This information can be used to predict the effectiveness of deploying Nannochloropsis oculata in similar field conditions for commercial biofuel production. © 2014 Tamburic et al

    Doing synthetic biology with photosynthetic microorganisms

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    The use of photosynthetic microbes as synthetic biology hosts for the sustainable production of commodity chemicals and even fuels has received increasing attention over the last decade. The number of studies published, tools implemented, and resources made available for microalgae have increased beyond expectations during the last few years. However, the tools available for genetic engineering in these organisms still lag those available for the more commonly used heterotrophic host organisms. In this mini-review, we provide an overview of the photosynthetic microbes most commonly used in synthetic biology studies, namely cyanobacteria, chlorophytes, eustigmatophytes and diatoms. We provide basic information on the techniques and tools available for each model group of organisms, we outline the state-of-the-art, and we list the synthetic biology tools that have been successfully used. We specifically focus on the latest CRISPR developments, as we believe that precision editing and advanced genetic engineering tools will be pivotal to the advancement of the field. Finally, we discuss the relative strengths and weaknesses of each group of organisms and examine the challenges that need to be overcome to achieve their synthetic biology potential.Peer reviewe

    From information provider to research service provider - shifting the perception of library work through open access at the medicine and sciences library of the Leipzig University

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    This practice report reflects on the relevance of the Leipzig University Library's various offerings and services in the field of open access publishing as well as current and future points of contact and challenges related to the open access transformation from the perspective of the medicine and sciences library. In particular, the publication services provided by the open access publication fund have enabled the library to establish itself as a service provider for research. In addition to the classical topics of information literacy, the transfer of knowledge about publishing and the publication market is also becoming increasingly relevant.In diesem Praxisbericht werden aus der Perspektive der Bibliothek Medizin/Naturwissenschaften der UniversitĂ€t Leipzig die Relevanz der verschiedenen Angebote und Dienstleistungen der UniversitĂ€tsbibliothek zum Thema Open-Access-Publizieren sowie aktuelle und zukĂŒnftige BerĂŒhrungspunkte und Herausforderungen im Zusammenhang mit der Open-Access-Transformation reflektiert. Speziell durch die Publikationsdienstleistungen um den Open-Access-Publikationsfonds konnte sich die Bibliothek in der Wahrnehmung der Wissenschaftlerinnen und Wissenschaftler als Dienstleister fĂŒr die Forschung etablieren. Ebenso wird neben den klassischen Themen der Informationskompetenz die Vermittlung von Kenntnissen zum Publikationswesen und zum Publikationsmarkt zunehmend relevant

    Relapse After Early-Stage, Favorable Hodgkin Lymphoma: Disease Characteristics and Outcomes With Conventional or High-Dose Chemotherapy.

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    PURPOSE We evaluated disease and treatment characteristics of patients with relapse after risk-adapted first-line treatment of early-stage, favorable, classic Hodgkin lymphoma (ES-HL). We compared second-line therapy with high-dose chemotherapy and autologous stem cell transplantation (ASCT) or conventional chemotherapy (CTx). METHODS We analyzed patients with relapse after ES-HL treated within the German Hodgkin Study Group HD10+HD13 trials. We compared, by Cox proportional hazards regression, progression-free survival (PFS) after relapse (second PFS) treated with either ASCT or CTx and performed sensitivity analyses with overall survival (OS) from relapse and Kaplan-Meier statistics. RESULTS A total of 174 patients' disease relapsed after treatment in the HD10 (n = 53) and HD13 (n = 121) trials. Relapse mostly occurred > 12 months after first diagnosis, predominantly with stage I-II disease. Of 172 patients with known second-line therapy, 85 received CTx (49%); 70, ASCT (41%); 11, radiotherapy only (6%); and 4, palliative single agent therapies (2%). CTx was predominantly bleomycin, etoposide, doxorubicin cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP [68%]), followed by the combination regimen of doxorubicin, bleomycin, vinblastine, and dacarbazine (19%), or other regimens (13%). Patients aged > 60 years at relapse had shorter second PFS (hazard ratio [HR], 3.0; P = .0029) and were mostly treated with CTx (n = 33 of 49; 67%) and rarely with ASCT (n = 8; 16%). After adjustment for age and a disadvantage of ASCT after the more historic HD10 trial, we did not observe a significant difference in the efficacy of CTx versus ASCT for second PFS (HR, 0.7; 95% CI, 0.3 to 1.6; P = .39). In patients in the HD13 trial who were aged ≀ 60 years, the 2-year, second PFS rate was 94.0% with CTx (95% CI, 85.7% to 100%) versus 83.3% with ASCT (95% CI, 71.8% to 94.8%). Additional sensitivity analyses including OS confirmed these observations. CONCLUSION After contemporary treatment of ES-HL, relapse mostly occurred > 12 months after first diagnosis. Polychemotherapy regimens such as BEACOPP are frequently administered and may constitute a reasonable treatment option for selected patients with relapse after ES-HL
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