Comprehensive characterization of two different Nicotiana tabacum cell lines leads to doubled GFP and HA protein production by media optimization

For over two decades, plant cell cultures have been a promising research platform to express recombinant and therapeutic proteins such as hormones, growth factors, full-size antibodies and antigens. Chosen as a good host for manufacturing recombinant proteins, the Nicotiana tabacum L. cv. Bright Yellow 2 (BY-2) cell line has been studied in shake flasks by offline analysis of only a few growth parameters. The objective of this study is to comprehensively characterize the growth of a transgenic BY-2 cell line and to investigate the expression profile of the model protein GFP. Based on the correlations between nutrient consumption, cell growth and product formation, the intention is to improve the standard MS-medium. Hereby, multiple growth parameters were analyzed offline and online by using a respiration activity monitoring system (RAMOS). A reproducibly observed shift of the oxygen transfer rate (OTR) could be identified to indicate ammonium depletion in the medium. Concurrent with this ammonium depletion, the total protein concentration began to decrease. After the MS-medium was improved, the GFP concentration nearly doubled. When this improved ammonium enriched medium was applied to another transgenic tobacco cell line similar improvements to the amount of the glycoprotein influenza hemagglutinin (HA) produced by Nicotiana tabacum NT-1 cells could be achieved. Ultimately, this combined offline and online analysis can be successfully used for further cell line characterization and media optimization to improve growth and boost target product formation.     

Strong Photoacoustic Signal Enhancement by Coating Gold Nanoparticles with Melanin for Biomedical Imaging

Photoacoustics is a powerful biomedical imaging and detection technique, because it is a noninvasive, nonionizing, and low‐cost method facilitating deep tissue penetration. However, suitable contrast agents need to be developed to increase the contrast for in vivo imaging. Gold nanoparticles are often discussed as potential sonophores due to their large absorption cross‐section and their tunable plasmon resonance. However, disadvantages such as toxicity and low photoacoustic efficiency in the tissue transparency window prevail, preventing their clinical application. As a result, there remains a strong need to develop colloidal photoacoustic contrast agents which absorb in the tissue transparency window, exhibit high photoacoustic signal, and are biocompatible. Here, a facile synthetic approach is presented to produce melanin shells around various gold nanoparticle geometries, from spheres to stars and rods. These hybrid particles show excellent dispersability, better biocompatibility, and augmented photoacoustic responses over the pure melanin or pristine gold particles, with a rod‐shape geometry leading to the highest performance. These experimental results are corroborated using numerical calculations and explain the improved photoacoustic performance with a thermal confinement effect. The applicability of melanin coated gold nanorods as gastrointestinal imaging probes in mouse intestine is showcased.     

Einsatz von Biowäschern in der chemischen Produktion

Use of bioscrubbers in the chemical industry. Bioscrubbers are an ecologically and economically interesting alternative to conventional processes like combustion, adsorption and absorption. A brief account of the microbiological and engineering fundamentals of bioscrubbers are given followed by a review of new developments illustrating improvements in process design. The field of application for bioscrubbers is continuously expanding. Two examples of the use of bioscrubbers are discussed. They demonstrate the feasibility of deodorization of slightly contaminated waste gas, as well as the purification of waste gas which is highly loaded with organic substances. The authors describe a new concept for reduction of local hold up of biosuspension at the bioscrubber by integrating the waste water plant as a superior reservoir for fresh biosuspension. The most important advantages of the new concept are as follows: No problems with shut-off time, a better safety in operation, and ready adaptation of the process to changing parameters.     

无建筑 亦无景观

……既无建筑,亦无景观,就一个承诺,承诺有一个地方,能够令您穿越空间……德国Archimedialab建筑事务所如是描述着自己的设计。无建筑,无景观并不意味着空间的缺失,而是在设计元素的因势利导下完成了环境的共生设计,产生出别样的空间体验。在设计中运用独具匠心的构思,尝试将非常规     

Upper respiratory tract disease and mycoplasmosis in desert tortoises from Nevada

A population of desert tortoises (Gopherus agassizii) at Yucca Mountain (Nevada, USA) was monitored during four sampling periods using enzyme-linked immunosorbent assays (ELISA) to determine the percentage of individuals that had been exposed to Mycoplasma agassizii, a causative agent of upper respiratory tract disease. Respiratory tract disease has been considered a significant factor in the decline of desert tortoise populations in the Mojave Desert (USA). Few differences between sexes in ELISA values or percentages testing positive were noted. From 15 to 23% of samples per period tested positive for exposure to the mycoplasma. However, we noted few clinical signs of upper respiratory tract disease. This is in contrast to an earlier study which reported a similar proportion of seropositive tortoises as well as a high percentage of tortoises with clinical signs. However, our results are consistent with that study's conclusion that seropositivity for M. agassizii was a poor predictor of the likelihood to exhibit clinical signs of upper respiratory tract disease. Earlier reported epizootics of mycoplasma-associated respiratory disease occurred mainly during times of drought. Our samples were collected during a period of average to above-average rainfall, suggesting that manifestation of clinical signs of the disease may depend upon the physiological condition of tortoises which, in turn, is related to environmental conditions.