Acute graft-vs-host disease (GVHD) is a serious complication after allografting. We carried out an exploratory study to investigate a potential correlation of surface antigens on extracellular ...vesicles (EVs) and acute GVHD. EVs were extracted from serum samples from 41 multiple myeloma patients who underwent allografting. EVs were characterized by flow cytometry using a panel of 13 antibodies against specific membrane proteins that were reported to be predictive of acute GVHD. We observed a correlation between three potential biomarkers expressed on EV surface and acute GVHD onset by both logistic regression analysis and Cox proportional hazard model. In our study, CD146 (MCAM-1) was correlated with an increased risk-by almost 60%-of developing GVHD, whereas CD31 and CD140-α (PECAM-1 and PDGFR-α) with a decreased risk-by almost 40 and 60%, respectively. These biomarkers also showed a significant change in signal level from baseline to the onset of acute GVHD. Our novel study encourages future investigations into the potential correlation between EVs and acute GVHD. Larger prospective multicenter studies are currently in progress.
Several complex processes are involved in the production of viable eggs. The aim of this review is to provide an overview on the role played by lysosomal enzymes, especially cathepsins B, D, and L, ...during ovarian follicle growth and maturation. Specific attention is focused on the relationship between the second proteolytic cleavage of yolk proteins (YP) and the resumption of the meiosis during germinal vesicle break down (GVBD). Maturation represents the final stage of oocytes development prior to ovulation. Oocytes in this phase appear translucent. In many teleosts GVBD is accompanied by water uptake and among marine teleosts with pelagic eggs, most of the final volume is reached by this process. The last phase of maturation in benthonic eggs also occurs concomitant to a second proteolytic cleavage and is related with a slight hydration process. In vitro maturation by 17α,20β-dihydroxy-4-pregnen-3one in class III
Danio rerio oocytes, induced 80% of GVBD. The maturation of these oocytes is known to be associated with proteolysis of their major yolk components. In the present study, we show that inhibition of specific enzymes (cathepsins) involved in the second YP processing, did not affect the occurrence of GVBD as the oocytes become translucent and display a slight increase in size. More specifically, in vitro incubation of the maturing oocytes with a cathepsin B inhibitor suppressed both cathepsin B and L activities and the proteolysis of YP. On the contrary, the addition of cathepsin L inhibitor, only affected cathepsin L activity, indicating that cathepsin B is probably involved in Cathepsin L activation, and this enzyme is probably responsible for the second YP processing. These results, together with previous studies, indicate that the GVBD process is independent of the occurrence of the second proteolytic process. It supports the hypothesis that the maturation process is under K
+ ion flux control, while yolk proteolysis is related to the temporal and specific activation of cathepsins by acidification of yolk spheres.
Silicon Photomultipliers (SiPM) are photodetectors optimized for the detection of infrared to ultraviolet photons and employed in a wide range of fast timing applications for medical imaging and ...particle detectors. SiPMs are used to detect the passage of ionizing radiation into matter via the collection of secondary photons emitted by the radiator material. In this work, we have investigated the possibility to detect high intensity X-ray fluxes using the DC current produced by SiPMs exposed directly to the X-ray beam, in absence of any passive converter material, to demonstrate the possibility to measure intense radiation fluxes without saturation of the SiPM response. In our application, the signal-to-noise ratio of the SiPM current during the direct exposition to X-rays is typically larger than 100, providing a robust indication of a positive detection. We show that, for a wide range of operational parameters and X-ray flux intensities, the SiPM current can be correlated to the X-ray beam intensity using a parametrization that describes the data with an accuracy of the order or better than 1%. We also show that the SiPM signal current to dark current ratio is maximum for hundreds of mV above the breakdown voltage, with a weak dependence on temperature. These results open the prospects for interesting applications for monitoring intense X-ray beams, for example beam spatial profiling, and possibly real time dosimetry both in medical and industrial applications.
Abstract Hydrogenated amorphous silicon (a-Si:H) is a material with a very good radiation hardness and with the possibility of deposition on flexible substrates like Polyimide (PI). Exploiting these ...properties, the HASPIDE (Hydrogenated Amorphous Silicon PIxels DEtectors) project has the goal of developing a-Si:H detectors on flexible substrates for beam dosimetry and profile monitoring, neutron detection and space experiments. The detectors for this experiment will be developed in two different structures: the n-i-p diode structure, which has been used up to now for the construction of the planar a-Si:H detectors, and the recently developed charge selective contact structure. In the latter the doped layers (n or p) are replaced with charge selective materials namely electron-selective conductive metal-oxides (TiO 2 or Al:ZnO) and hole-selective conductive metal oxides (MoO x ). In this paper preliminary data on the capabilities of these detectors to measure X-ray and electron fluxes will be presented. In particular, the linearity, the sensitivity, the stability and dark current in various conditions will be discussed.
The Schwarzschild Couder Medium Size Telescope prototype (pSCT) is going to test the Schwarzschild Couder solution proposed for Medium Size telescopes for the Cherenkov Telescope Array. The camera ...consists of 177 photodetection modules grouped into sectors of maximum 25 modules each. The sensitive elements of the modules, located in the focal plane of the telescope, are matrices of 64 6 mm × 6 mm pixels of Silicon Photomultipliers (SiPMs). The front-end electronics is designed for signal sampling technique using the TARGET-7 ASIC. The prototype under construction and test at the Fred Lawrence Whipple Observatory site will be equipped with the inner central sector fully operational. Sensors from Fondazione Bruno Kessler will be used for 9 of the 25 modules. A complete characterization of these very recent, highly sensitive Near UV sensors, the assembly procedure and metrology results on several focal plane elements has been conducted. Performances of the 16-sensors matrices and measurements with the TARGET-7 ASIC front-end coupled to FBK sensors will be shown and deeply discussed.
•A camera for the prototype Schwarzschild Couder Telescope for CTA is being tested.•A 16-FBK SiPM matrix was studied and its homogeneity was verified.•The TARGET 7 readout module was coupled and optimized to the FBK SiPMs.
We have studied the impact of several Si selective epitaxial growth (SEG) process on the agglomeration of ultra-thin, patterned silicon-on-insulator (SOI) layers. Through a careful analysis of the ...effects of the in situ H
2 bake temperature (that followed an ex situ “HF-last” wet cleaning) and of the silicon growth temperature on the SOI film quality, we have been able to develop a low-temperature SEG process that allows the growth of Si on patterned SOI layers as thin as 3.4
nm without any agglomeration or Si moat recess at the Si window/shallow trench isolation edges. This process consists of an in situ H
2 bake at 650
°C for 2
min, followed by a ramping-up of the temperature to 750
°C, then some SEG of Si at 750
°C using a chlorinated chemistry (i.e. SiH
2Cl
2+HCl).
To set up specification for 3D monolithic integration, for the first time, the thermal stability of state-of-the-art FDSOI (Fully Depleted SOI) transistors electrical performance is quantified. Post ...fabrication annealings are performed on FDSOI transistors to mimic the thermal budget associated to top layer processing. Degradation of the silicide for thermal treatments beyond 400°C is identified as the main responsible for performance degradation for PMOS devices. For the NMOS transistors, arsenic (As) and phosphorus (P) dopants deactivation adds up to this effect. By optimizing both the n-type extension implantations and the bottom silicide process, thermal stability of FDSOI can be extended to allow relaxing upwards the thermal budget authorized for top transistors processing.
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