334 research outputs found
Systematic genetic array (SGA) screening for stress-regulating factors in Saccharomyces cerevisiae
Systematisches genetisches Array Screening in Saccharomyces cerevisiae (Bilder sind vorhanden).Systematic genetic array screening in Saccharomyces cerevisiae
Dynamic cultivation of human mesenchymal stem/stromal cells for the production of extracellular vesicles in a 3D bioreactor system
Purpose: 3D cell culture and hypoxia have been demonstrated to increase the therapeutic effects of mesenchymal stem/stromal cells (MSCs)-derived extracellular vesicles (EVs). In this study, a process for the production of MSC-EVs in a novel 3D bioreactor system under normoxic and hypoxic conditions was established and the resulting EVs were characterized. Methods: Human adipose-derived MSCs were seeded and cultured on a 3D membrane in the VITVOÂź bioreactor system for 7 days. Afterwards, MSC-EVs were isolated and characterized via fluorescence nanoparticle tracking analysis, flow cytometry with staining against annexin V (Anx5) as a marker for EVs exposing phosphatidylserine, as well as CD73 and CD90 as MSC surface markers. Results: Cultivation of MSC in the VITVOÂź bioreactor system demonstrated a higher concentration of MSC-EVs from the 3D bioreactor (9.1 Ă 109 ± 1.5 Ă 109 and 9.7 Ă 109 ± 3.1 Ă 109 particles/mL) compared to static 2D culture (4.2 Ă 109 ± 7.5 Ă 108 and 3.9 Ă 109 ± 3.0 Ă 108 particles/mL) under normoxic and hypoxic conditions, respectively. Also, the particle-to-protein ratio as a measure for the purity of EVs increased from 3.3 Ă 107 ± 1.1 Ă 107 particles/”g protein in 2D to 1.6 Ă 108 ± 8.3 Ă 106 particles/”g protein in 3D. Total MSC-EVs as well as CD73âCD90+ MSC-EVs were elevated in 2D normoxic conditions. The EV concentration and size did not differ significantly between normoxic and hypoxic conditions. Conclusion: The production of MSC-EVs in a 3D bioreactor system under hypoxic conditions resulted in increased EV concentration and purity. This system could be especially useful in screening culture conditions for the production of 3D-derived MSC-EVs
Agmatine modulates spontaneous activity in neurons of the rat medial habenular complexâa relevant mechanism in the pathophysiology and treatment of depression?
The dorsal diencephalic conduction system connects limbic forebrain structures to monaminergic mesencephalic nuclei via a distinct relay station, the habenular complexes. Both habenular nuclei, the lateral as well as the medial nucleus, are considered to play a prominent role in mental disorders like major depression. Herein, we investigate the effect of the polyamine agmatine on the electrical activity of neurons within the medial habenula in rat. We present evidence that agmatine strongly decreases spontaneous action potential firing of medial habenular neurons by activating I1-type imidazoline receptors. Additionally, we compare the expression patterns of agmatinase, an enzyme capable of inactivating agmatine, in rat and human habenula. In the medial habenula of both species, agmatinase is similarly distributed and observed in neurons and, in particular, in distinct neuropil areas. The putative relevance of these findings in the context of depression is discussed. It is concluded that increased activity of the agmatinergic system in the medial habenula may strengthen midbrain dopaminergic activity. Consequently, the habenular-interpeduncular axis may be dysregulated in patients with major depression
Laboratory-scale x-ray absorption spectroscopy of 3d transition metals in inorganic thin films
In this paper we present laboratory-scale X-ray absorption spectroscopy applied to the research of nanometer-scale thin films. We demonstrate the Cu K edge X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) of CuI and CuO thin films grown with atomic layer deposition. Film thicknesses in the investigated samples ranged from 12 to 248 nm. Even from the thinnest films, XANES spectra can be obtained in 5-20 minutes and EXAFS in 1-4 days. In order to prove the capability of laboratory-based XAS for in situ measurements on thin films, we demonstrate an experiment on in situ oxidation of a 248 nm thick CuI film at a temperature of 240 degrees C. These methods have important implications for novel and enhanced possibilities for inorganic thin film research.Peer reviewe
Anharmonic vs. relaxational sound damping in glasses: I. Brillouin scattering from densified silica
This series discusses the origin of sound damping and dispersion in glasses.
In particular, we address the relative importance of anharmonicity versus
thermally activated relaxation. In this first article, Brillouin-scattering
measurements of permanently densified silica glass are presented. It is found
that in this case the results are compatible with a model in which damping and
dispersion are only produced by the anharmonic coupling of the sound waves with
thermally excited modes. The thermal relaxation time and the unrelaxed velocity
are estimated.Comment: 9 pages with 7 figures, added reference
Gemini Planet Imager Observational Calibrations VI: Photometric and Spectroscopic Calibration for the Integral Field Spectrograph
The Gemini Planet Imager (GPI) is a new facility instrument for the Gemini
Observatory designed to provide direct detection and characterization of
planets and debris disks around stars in the solar neighborhood. In addition to
its extreme adaptive optics and corona graphic systems which give access to
high angular resolution and high-contrast imaging capabilities, GPI contains an
integral field spectrograph providing low resolution spectroscopy across five
bands between 0.95 and 2.5 m. This paper describes the sequence of
processing steps required for the spectro-photometric calibration of GPI
science data, and the necessary calibration files. Based on calibration
observations of the white dwarf HD 8049B we estimate that the systematic error
in spectra extracted from GPI observations is less than 5%. The flux ratio of
the occulted star and fiducial satellite spots within coronagraphic GPI
observations, required to estimate the magnitude difference between a target
and any resolved companions, was measured in the -band to be in laboratory measurements and using
on-sky observations. Laboratory measurements for the , , and
filters are also presented. The total throughput of GPI, Gemini South and the
atmosphere of the Earth was also measured in each photometric passband, with a
typical throughput in -band of 18% in the non-coronagraphic mode, with some
variation observed over the six-month period for which observations were
available. We also report ongoing development and improvement of the data cube
extraction algorithm.Comment: 15 pages, 6 figures. Proceedings of the SPIE, 9147-30
Multimodal Remote Home Monitoring of Lung Transplant Recipients during COVID-19 Vaccinations: Usability Pilot Study of the COVIDA Desk Incorporating Wearable Devices
Background and Objectives: Remote patient monitoring (RPM) of vital signs and symptoms for lung transplant recipients (LTRs) has become increasingly relevant in many situations. Nevertheless, RPM research integrating multisensory home monitoring in LTRs is scarce. We developed a novel multisensory home monitoring device and tested it in the context of COVID-19 vaccinations. We hypothesize that multisensory RPM and smartphone-based questionnaire feedback on signs and symptoms will be well accepted among LTRs. To assess the usability and acceptability of a remote monitoring system consisting of wearable devices, including home spirometry and a smartphone-based questionnaire application for symptom and vital sign monitoring using wearable devices, during the first and second SARS-CoV-2 vaccination. Materials and Methods: Observational usability pilot study for six weeks of home monitoring with the COVIDA Desk for LTRs. During the first week after the vaccination, intensive monitoring was performed by recording data on physical activity, spirometry, temperature, pulse oximetry and self-reported symptoms, signs and additional measurements. During the subsequent days, the number of monitoring assessments was reduced. LTRs reported on their perceptions of the usability of the monitoring device through a purpose-designed questionnaire. Results: Ten LTRs planning to receive the first COVID-19 vaccinations were recruited. For the intensive monitoring study phase, LTRs recorded symptoms, signs and additional measurements. The most frequent adverse events reported were local pain, fatigue, sleep disturbance and headache. The duration of these symptoms was 5â8 days post-vaccination. Adherence to the main monitoring devices was high. LTRs rated usability as high. The majority were willing to continue monitoring. Conclusions: The COVIDA Desk showed favorable technical performance and was well accepted by the LTRs during the vaccination phase of the pandemic. The feasibility of the RPM system deployment was proven by the rapid recruitment uptake, technical performance (i.e., low number of errors), favorable user experience questionnaires and detailed individual user feedback
Advanced Flow Cytometry Assays for Immune Monitoring of CAR-T Cell Applications
Adoptive immunotherapy using chimeric antigen receptor (CAR)-T cells has achieved
successful remissions in refractory B-cell leukemia and B-cell lymphomas. In order to
estimate both success and severe side effects of CAR-T cell therapies, longitudinal
monitoring of the patientâs immune system including CAR-T cells is desirable to
accompany clinical staging. To conduct research on the fate and immunological impact
of infused CAR-T cells, we established standardized 13-colour/15-parameter flow
cytometry assays that are suitable to characterize immune cell subpopulations in the
peripheral blood during CAR-T cell treatment. The respective staining technology is based
on pre-formulated dry antibody panels in a uniform format. Additionally, further antibodies
of choice can be added to address specific clinical or research questions. We designed
panels for the anti-CD19 CAR-T therapy and, as a proof of concept, we assessed a
healthy individual and three B-cell lymphoma patients treated with anti-CD19 CAR-T cells.
We analyzed the presence of anti-CD19 CAR-T cells as well as residual CD19+ B cells, the
activation status of the T-cell compartment, the expression of co-stimulatory signaling
molecules and cytotoxic agents such as perforin and granzyme B. In summary, this work
introduces standardized and modular flow cytometry assays for CAR-T cell clinical
research, which could also be adapted in the future as quality controls during the CART
cell manufacturing process
A white dwarf cooling age of 8 Gyr for NGC 6791 from physical separation processes
NGC 6791 is a well studied open cluster1 that it is so close to us that can
be imaged down to very faint luminosities. The main sequence turn-off age (~8
Gyr) and the age derived from the termination of the white dwarf cooling
sequence (~6 Gyr) are significantly different. One possible explanation is that
as white dwarfs cool, one of the ashes of helium burning, 22Ne, sinks in the
deep interior of these stars. At lower temperatures, white dwarfs are expected
to crystallise and phase separation of the main constituents of the core of a
typical white dwarf, 12C and 16O, is expected to occur. This sequence of events
is expected to introduce significant delays in the cooling times, but has not
hitherto been proven. Here we report that, as theoretically anticipated,
physical separation processes occur in the cores of white dwarfs, solving the
age discrepancy for NGC 6791.Comment: 3 pages, 2 figures, published in Natur
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