In the
γ
-ray Cherenkov Astronomy framework mirror coating plays a crucial role in defining the light response of the telescope. We carried out a study for new mirror coating solutions with both a ...numerical simulation software and a vacuum chamber for small sample production. In this article, we present a new mirror coating solution consisting of a 28-layer interferometric SiO
2
-TiO
2
-HfO
2
design deposited on a glass substrate, whose average reflectance is above 90
%
for normally incident light in the wavelength range between 300 and 550 nm.
After the shutdown of the Hubble Space Telescope in a few years, new astronomical missions for the ultraviolet (UV) wavelength range between 91 and 300 nm with improved optics and detectors will be ...necessary. This fact drives our development of solar blind photon counting microchannel plate (MCP) UV detectors with high quantum efficiency, high spatial resolution, and low power readout electronics. We plan to use a cross-strip anode (XSA), which has a high spatial resolution and additionally allows a low gain operation of the MCPs which leads to an increased lifetime of the MCPs compared to detectors with other anode types. The main difficulty in implementing an XSA in a detector for space applications is the need for a (pre-) amplifier, a shaper, and an ADC for each of the strips, which means large power consumption and spatial requirements. The solution we are studying is the application of the so-called Beetle chip. This allows for an implementation of a readout electronics for an XSA with a power consumption of less then 10 W. For the tests of our readout electronics prototype, and for the burn-in of the MCPs, we recently finished a setup in a vacuum chamber that is similar to the configuration in the final detector. We present a brief overview of our detector design and details of the readout electronics setup as well as details of the setup in our vacuum chamber.
The main instrument of the WSO-UV satellite covers the wavelength range of 102-176 nm and 174-310 nm with two high resolution echelle spectrographs. The essential requirements for the associated ...detectors are high quantum efficiency, solar blindness, and single photon detection. To achieve this, we are developing microchannel plate (MCP) detectors in sealed tubes. It is planned to use cesium activated gallium nitride as semitransparent photocathode, a stack of two microchannel plates in chevron configuration, and a 33 mm × 44 mm cross strip anode with 64 horizontal and 64 vertical electrodes. This type of anode requires a lower gain of the MCPs ( ≈ 10 6 ) compared to other types of anodes. Therefore, it extends the expected lifetime of the detectors to about five to ten years. The challenge for the use of a cross strip anode onboard the WSO-UV satellite is the combination of contradictory constraints on the readout electronics: On the one hand it should be able to handle a maximum count rate of 3·10 5 s -1 with a spatial resolution better than 15 μm . On the other hand the power consumption is limited to about 8 W. One feasible solution is the so-called Beetle chip. This chip provides 128 input channels with charge-sensitive preamplifiers and shapers. It stores the sampled data temporarily in a ring buffer and multiplexes it to four analogue readout channels. The output is then digitized by four ADCs and processed in a radiation hard FPGA, which also contains the space-wire interface to the satellite bus.
This work presents a hardware-in-the-loop (HIL) testing approach for hands-free car kits. The HIL system can be used to simulate the sound propagation within the car cabin. The proposed system is ...based on low latency and low complexity FIR filtering. It provides sufficient accuracy when employed in a measurement system for quality assessments according to the VDA specification for car hands-free measurements.
The properties, structure, and processing of carbon fibers are reviewed. Carbon fibers are made from several precursors, with PAN being the dominating precursor in the market. Carbon fibers have high ...tensile strength, high modulus (up to the theoretical limit of around 1000 GPa), and low density, depending on the structure and processing in very limited combinations. Both the structure and composition of the precursor affect the properties of the resulting carbon fibers significantly. Although the essential processes for carbon fiber production are similar, different precursors require different processing conditions in order to achieve improved performance. Future developments are discussed.
The basics and fundamentals of carbon fiber synthesis are highlighted, particularly focusing on polyacrylonitrile‐, pitch‐, and lignin‐derived carbon fibers. For these, the key issues in terms of precursor copolymer composition, spinning, stabilization, and carbonization are summarized. Where feasible, structure–property relationships are presented.
Mesenchymal stromal cells (MSCs) are attractive for cell-based therapies ranging from regenerative medicine and tissue engineering to immunomodulation. However, clinical efficacy is variable and it ...is unclear how the phenotypes defining bone marrow (BM)-derived MSCs as well as donor characteristics affect their functional properties.
BM-MSCs were isolated from 53 (25 female, 28 male; age: 13 to 80 years) donors and analyzed by: (1) phenotype using flow cytometry and cell size measurement; (2) in vitro growth kinetics using population doubling time; (3) colony formation capacity and telomerase activity; and (4) function by in vitro differentiation capacity, suppression of T cell proliferation, cytokines and trophic factors secretion, and hormone and growth factor receptor expression. Additionally, expression of Oct4, Nanog, Prdm14 and SOX2 mRNA was compared to pluripotent stem cells.
BM-MSCs from younger donors showed increased expression of MCAM, VCAM-1, ALCAM, PDGFRβ, PDL-1, Thy1 and CD71, and led to lower IL-6 production when co-cultured with activated T cells. Female BM-MSCs showed increased expression of IFN-γR1 and IL-6β, and were more potent in T cell proliferation suppression. High-clonogenic BM-MSCs were smaller, divided more rapidly and were more frequent in BM-MSC preparations from younger female donors. CD10, β1integrin, HCAM, CD71, VCAM-1, IFN-γR1, MCAM, ALCAM, LNGFR and HLA ABC were correlated to BM-MSC preparations with high clonogenic potential and expression of IFN-γR1, MCAM and HLA ABC was associated with rapid growth of BM-MSCs. The mesodermal differentiation capacity of BM-MSCs was unaffected by donor age or gender but was affected by phenotype (CD10, IFN-γR1, GD2). BM-MSCs from female and male donors expressed androgen receptor and FGFR3, and secreted VEGF-A, HGF, LIF, Angiopoietin-1, basic fibroblast growth factor (bFGF) and NGFB. HGF secretion correlated negatively to the expression of CD71, CD140b and Galectin 1. The expression of Oct4, Nanog and Prdm14 mRNA in BM-MSCs was much lower compared to pluripotent stem cells and was not related to donor age or gender. Prdm14 mRNA expression correlated positively to the clonogenic potential of BM-MSCs.
By identifying donor-related effects and assigning phenotypes of BM-MSC preparations to functional properties, we provide useful tools for assay development and production for clinical applications of BM-MSC preparations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
BACKGROUND
Endothelial colony‐forming progenitor cells (ECFCs) are promising candidates for cell therapies. However, ECFC translation to the clinic requires optimized isolation and manufacture ...technologies according to good manufacturing practice (GMP).
STUDY DESIGN AND METHODS
ECFCs were manufactured from steady‐state peripheral blood (PB) leukapheresis (11 donors), using GMP‐compliant technologies including pooled human platelet (PLT) lysate, and compared to human umbilical cord endothelial cells, human aortic endothelial cells, and human cerebral microvascular endothelial cells. Specific variables assessed were growth kinetics, phenotype, trophic factors production, stimulation of tube formation, and Dil‐AcLDL uptake.
RESULTS
ECFCs could be isolated from PB leukapheresis units with mean processed volume of 5411 mL and mean white blood cell (WBC) concentration factor of 8.74. The mean frequency was 1.44 × 10−8 ECFCs per WBC, corresponding to a mean of 177.8 ECFCs per apheresis unit. Expandable for up to 12 cumulative population doublings, calculated projection showed that approximately 730 × 103 ECFCs could be manufactured from 1 apheresis unit. ECFCs produced epidermal growth factor, hepatocyte growth factor, vascular endothelial growth factor (VEGF)‐A, PLT‐derived growth factor‐B, interleukin‐8, and monocyte chemoattractant protein‐1, featured high potential for capillary‐like tubes formation, and showed no telomerase activity. They were characterized by CD29, CD31, CD44, CD105, CD117, CD133, CD144, CD146, and VEGF‐R2 expression, with the most common subpopulation CD34+CD117–CD133–. Compared to controls, ECFCs featured greater Dil‐AcLDL uptake and higher expression of CD29, CD31, CD34, CD44, CD144, and VEGF‐R2.
CONCLUSIONS
Here we show that isolation of ECFCs with proangiogenic profile from steady‐state PB leukapheresis is feasible, marking a first step toward ECFC product manufacture according to GMP.
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