1,970 research outputs found
Functional protection by acute phase proteins alpha(1)-acid glycoprotein and alpha(1)-antitrypsin against ischemia/reperfusion injury by preventing apoptosis and inflammation.
BACKGROUND: Ischemia followed by reperfusion (I/R) causes apoptosis, inflammation, and tissue damage leading to organ malfunction. Ischemic preconditioning can protect against such injury. This study investigates the contribution of the acute phase proteins alpha(1)-acid glycoprotein (AGP) and alpha(1)-antitrypsin (AAT) to the protective effect of ischemic preconditioning in the kidney. METHODS AND RESULTS: Exogenous AGP and AAT inhibited apoptosis and inflammation after 45 minutes of renal I/R in a murine model. AGP and AAT administered at reperfusion prevented apoptosis at 2 hours and 24 hours, as evaluated by the presence of internucleosomal DNA cleavage, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, and the determination of renal caspase-1- and caspase-3-like activity. AGP and AAT exerted anti-inflammatory effects, as reflected by reduced renal tumor necrosis factor-alpha expression and neutrophil influx after 24 hours. In general, these agents improved renal function. Similar effects were observed when AGP and AAT were administered 2 hours after reperfusion but to a lesser extent and without functional improvement. Moreover, I/R elicited an acute phase response, as reflected by elevated serum AGP and serum amyloid P (SAP) levels after 24 hours, and increased hepatic acute phase protein mRNA levels after 18 hours of renal reperfusion. CONCLUSIONS: We propose that the antiapoptotic and anti-inflammatory effects of AGP and AAT contribute to the delayed type of protection associated with ischemic preconditioning and other insults. This mechanism is potentially involved in the course of many clinical conditions associated with I/R injury. Moreover, exogenous administration of these proteins may provide new therapeutic means of treatmen
KLEIN: A New Family of Lightweight Block Ciphers
Resource-efficient cryptographic primitives become fundamental for realizing both security and efficiency in embedded systems like RFID tags and sensor nodes. Among those primitives, lightweight block cipher plays a major role as a building block for security protocols. In this paper, we describe a new family of lightweight block ciphers named KLEIN, which is designed for resource-constrained devices such as wireless sensors and RFID tags. Compared to the related proposals, KLEIN has advantage in the software performance on legacy sensor platforms, while in the same time its hardware implementation can also be compact
Detecting time-fragmented cache attacks against AES using Performance Monitoring Counters
Cache timing attacks use shared caches in multi-core processors as side
channels to extract information from victim processes. These attacks are
particularly dangerous in cloud infrastructures, in which the deployed
countermeasures cause collateral effects in terms of performance loss and
increase in energy consumption. We propose to monitor the victim process using
an independent monitoring (detector) process, that continuously measures
selected Performance Monitoring Counters (PMC) to detect the presence of an
attack. Ad-hoc countermeasures can be applied only when such a risky situation
arises. In our case, the victim process is the AES encryption algorithm and the
attack is performed by means of random encryption requests. We demonstrate that
PMCs are a feasible tool to detect the attack and that sampling PMCs at high
frequencies is worse than sampling at lower frequencies in terms of detection
capabilities, particularly when the attack is fragmented in time to try to be
hidden from detection
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Tumor necrosis factor-alpha regulates the expression of inducible costimulator receptor ligand on CD34+ progenitor cells during differentiation into antigen presenting cells
The inducible costimulator receptor (ICOS) is a third member of the CD28 receptor family that regulates T cell activation and function. ICOS binds to a newly identified ligand on antigen presenting cells different from the CD152 ligands CD80 and CD86. We used soluble ICOSIg and a newly developed murine anti-human ICOS ligand (ICOSL) monoclonal antibody to further characterize the ICOSL during ontogeny of antigen presenting cells. In a previous study, we found that ICOSL is expressed on monocytes, dendritic cells, and B cells. To define when ICOSL is first expressed on myeloid antigen presenting cells, we examined ICOSL expression on CD34 cells in bone marrow. We found that CD34bright cells regardless of their myeloid commitment were ICOSL , whereas ICOSL was first expressed when CD34 expression diminished and the myeloid marker CD33 appeared
Neutron Scattering to Characterize Cu/Mg(Li) Destabilized Hydrogen Storage Materials
Cu-Li-Mg-(H,D) was studied as an example of destabilizer of the Ti-(H,D) system. A Cu-Li-Mg alloy was prepared resulting in the formation of a system with 60.5 at% of CuLi0.08Mg1.92, 23.9 at% of CuMg 2 and 15.6 at% of Cu2Mg. Titanium was added to a fraction of this mixture so that 68.2 at% (47.3 wt%) of the final mixture was Ti. The mixture was ground and kept at 200 °C/473 K for 7h under H2 or 9h under D2 at P = 34 bar. Under those conditions, neutron powder diffraction shows the formation of TiD2, as well as of the deuteride of CuLi0.08Mg1.92. Similarly inelastic neutron scattering shows that at 10 K TiH2 is present in the sample, together with the hydride of CuLi0.08Mg1.92. Interestingly, at 10 K TiH 2 is very clearly detected and at 300 K TiH2 is still clearly present as indicated by the neutron vibrational spectrum, but CuLi 0.08Mg1.92-H is not detected anymore. These results indicate that Ti(H,D)2 is possibly formed by diffusion of hydrogen from the Cu-Li-Mg-(H,D) alloys. This is an intriguing result since TiH 2 is normally synthesized from the metal at T > 400°C/673 K (and most commonly at T ∼ 700 °C/973 K). In the presence of CuLi 0.08Mg1.92, TiH2 forms at a temperature that is 300 - 400 K lower than that needed to synthesize it just from the elements
Comprehensive analysis of liver macrophage composition by flow cytometry and immunofluorescence in murine NASH
Recently, it has become evident that macrophage diversity increases in the liver during the pathogenesis of non-alcoholic steatohepatitis (NASH). Here, we provide a detailed protocol for the analysis of liver macrophage subsets in mice with non-alcoholic fatty liver disease (NAFLD) and early NASH using flow cytometry and immunofluorescence (IF). These methods can be used to assess the composition and localization of macrophage subsets during NASH. For complete details on the use and execution of this protocol, please refer to Daemen et al. (2021)
First principles calculations and experiments to determine the hydrogenation process of Cu-Li-Mg
Density Functional Theory (DFT) calculations were performed. They were firstly implemented to optimize the structure and refine the stoichiometry of the only ternary compound, CuLi0.08Mg1.92 of the Cu-Li-Mg system. Furthermore using DFT, several possible structures of CuMg2Hx were optimized. Since most of the hydrides are cubic structures or can be considered as distortions of a cubic structure, we have started calculations for CuMg2Hx (x = 4 - 6)with tetragonal and monoclinic structures, similar to those of the hydrides formed by the nearest neighbors of Cu and Mg in the periodic table: NiMg2H4 and CoMg2H5 (e.g. monoclinic C2/c and tetragonal P4/nmm, respectively). It can be concluded that the most stable configuration corresponds to CuMg2H5 with C2/c structure. We have performed several neutron scattering experiments that are in agreement with the first principles calculations.</jats:p
Pre-procedural planning of transcatheter mitral valve replacement in mitral stenosis with multi-detector tomography-derived 3D modeling and printing: A case report
Background: Transcatheter mitral valve replacement (TMVR) may be a valuable treatment option for mitral annular calcification and severe mitral stenosis (MS) in patients at high operative risk. Pre-procedural virtual and printed simulations may aid in procedure planning, device sizing, and mitigate complications such as valve embolization or left ventricular outflow tract (LVOT) obstruction. Case summary: We describe a case of TMVR in which multi-detector computed tomography (MDCT) derived, three-dimensional virtual planning and a 3D-printed model of the patients' left heart provided enhanced understanding of an individual patient's unique anatomy to determine feasibility, device sizing, and risk stratification. This resulted in deployment of an adequately sized valve. Post-TMVR LVOT obstruction was treated with LVOT balloon dilatation and percutaneous transluminal septal myocardial ablation. Discussion: Advanced MDCT-derived planning techniques introduce consistent 3D modeling and printing to enhance understanding of intracardiac anatomical relationships and test device implantation. Still, static measurements do not feature haemodynamic factors, tissue, or device characteristics and do not predict device host interaction. Transcatheter mitral valve replacement is feasible in MS when adequately pre-procedurally planned. Multi-detector computed tomography-derived, 3D, virtual and printed models contribute to adequate planning in terms of determining patient eligibility, procedure feasibility, and device sizing. However, static 3D modeling cannot completely eliminate the risk of peri-procedural complications
Josephson Plasma Resonance in with Spatially Dependent Interlayer-Phase Coherence
We study the Josephson plasma resonance (JPR) in
BiSrCaCuO (BSCCO) with spatially dependent interlayer-phase
coherence (IPC). The half-irradiated BSCCO (HI-BSCCO), in which columnar
defects are introduced only in a half of the sample, shows several resonance
peaks, which are not simple superposition of the peaks in irradiated- and
pristine-parts. JPR in HI-BSCCO changes its character from irradiated- to
pristine-type at a crossover frequency (). We demonstrate that the
one-dimensional \LSGE, which takes into account the spatial dependence of IPC,
can reproduce most of the experimental findings including the presence of
.Comment: 4 figure
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