Participarea catepsinei l la biodegradarea colagenului în procesul de regresie a cirozei hepatice experimentale

Aplicând metode biochimice şi electron-histochimice, a fost studiată activitatea proteinazei cisteinice catepsinei L în fi catul afectat de ciroză şi în perioada de regresie a cirozei la şobolani. S-a determinat o activitate sporită a catepsinei L în ciroza hepatică, fi ind în scădere pe parcursul perioadei de regresie, precum şi un grad înalt de corelaţie între activitatea enzimei şi nivelul hidroxiprolinei în fi cat. Electron-histochimic activitatea catepsinei L a fost detectată în fagolizozomii celulelor Kupffer şi fi broblastelor, ce conţineau fi brile fragmentate de colagen. De asemenea, activitatea enzimei a fost detectată pe plasmalema hepatocitelor, celulelor Kupffer şi fi broblastelor, precum şi pe fi brilele de colagen adiacente. Activitatea extracelulară a catepsinei L indică că în afară de proteoliza intracelulară, enzima participă şi în degradarea extracelulară a colagenului, fi ind secretată în spaţiul extracelular de către hepatocite, macrofage şi fi broblaste

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

Reduction of the Number of Live Animals Used for Microsurgical Skill Acquisition: An Experimental Randomized Noninferiority Trial

Background Live animals have been used for decades as one of the many training models for developing surgical skills. Microsurgery in particular relies on training for skill acquisition and maintenance, using live animal models, especially rats (murine models). Efforts are underway to reduce the number of rats sacrificed to achieve this objective. Methods A group of students with minimal microsurgical experience, after having gone through a basic microsurgical course, were randomly split into three equal groups, all three groups following a 24-week standard training program based on low- and medium-fidelity training models with standardized murine training days. In addition to the standard training regimen, each participant performed supplementary training on live rats every 4, 6, or 8 weeks. According to the training program, the procedures have been performed on chicken legs, flower petals, and rats, each procedure being blindly assessed and evaluated using validated models and scales. The primary evaluated outcome was the Stanford Microsurgery and Resident Training (SMaRT) scale result of the final rat anastomosis performed by each group, for which the tested hypothesis was one of noninferiority. The secondary outcomes were represented by the final rat anastomosis time, final chicken leg anastomosis result and time, and the final petal score. Results After the 24th week, no differences were observed between the three groups regarding their microsurgical skills, as measured by the aforementioned surgical outcomes. All participants improved significantly during the study (mean [standard deviation] 19 ± 4 points on the SMaRT scale), with no significant differences between the groups, p < 0.001 for noninferiority. Conclusion A training regimen based on low- and moderate-fidelity models, with the addition of training on a live rat every 8 weeks was noninferior to a training regimen that used a live rat every 6 weeks and also noninferior to a training regimen that used a live rat every 4 weeks