749 research outputs found
Mitokondriális eredetű nitrogén szabadgyökök és ATP-függő K-csatornák szerepe az organellum működésében = The involvement of mitochondrial-derived nitrogen radicals and mitoK-ATP channels in the regulation of organelle function
ElsĹ‘kĂ©nt a mitoKATP csatornák alegysĂ©geit terveztĂĽk azonosĂtani humán szĂv mintákon. A kĂsĂ©rletek során megbizonyosodtunk afelĹ‘l, hogy a korábban ilyen csatornáknak gondolt fehĂ©rjĂ©k nincsenek jelen megfelelĹ‘ számban Ă©s formában a mitokondriális membránokban, ezĂ©rt a nem valĂłszĂnű hogy a mitokondirális ATP-fĂĽggĹ‘ kálium áramokat valĂłs mitoKATP csatornák folytatnák. A mitokondriális NO szintáz (mtNOS) enzimrendszer vizsgálata azonban nem várt Ăşj felfedezĂ©sekhez vezetett. Az elĹ‘kĂsĂ©rletekben is bemutatott, a pályázat során több fajra Ă©s szövetre (ember, egĂ©r, patkány, malac, szĂv, agy Ă©s máj) kiterjesztett, több párhuzamos mĂłdszerrel nyert eredmĂ©nyeink szerint bizonĂtottuk, hogy a feltĂ©telezett mtNOS nem azonos egyik ismert NOS variánssal sem. MegállapĂtottuk hogy a mitokondriális lĂ©gzĂ©si lánc ubiquinon ciklusának működĂ©se mentĂ©n keletkezĹ‘ nitrogĂ©n gyökök azok, amelyeket korábban a mtNOS-nak tulajdonĂtottak. A reakcióút pontosabb tisztázása vĂ©gett mitokondriumokat oxidatĂv stressznek vetettĂĽnk alá, ezzel fehĂ©rje modifikáciĂłt indukáltunk. Proteomikai mĂłdszerekkel (2D gĂ©lelektroforzis Ă©s tömegspektrometria) azonosĂtottuk nitrált Ă©s poly-ADP-rbozilált (PAR-ált) fehĂ©rjĂ©ket, köztĂĽk a mitokondirális dihidro-lipoamid dehidrogenázt amely a poliADP-riboziláciĂł folyamatot is katalizálhatja. KĂsĂ©rleteink ezzel egy teljesen Ăşj, fĂĽggetlen mitokondriális reakciĂłutat tártak fel. További kĂsĂ©rleteink a mitokondriális nitrogĂ©n monoxid metabolizmus Ă©s a cukorbetegsĂ©g kapcsolatát vizsgálták. | Our experimental findings indicated that there previously suspected potential mitoKATP channel subunits are not present in the required format and amount in human heart mitochondria, therefore, they cannot play a role in K fluxes. We extended our preliminary results about the nature of the putative mitochondrial NO synthase (mtNOS) to several species and tissues (human, mouse, rat, pig, heart, brain and liver) and concluded that mtNOS is not a variant of any known NOS enzymes. Mitochondria are capable of producing significant amounts of nitrogen radicals through the catalyzation of nitrosothiol release by the ubiquinon cycle of the respiratory chain. Subjecting mitochondria to oxidative stress resulted in the nitration and poly-ADPribosylation (PARylation) of proteins. Proteomic identification of the affected molecules revealed that dihydrolipoamide-dehydrogenase is PARylated and may act as a polyADP-ribose-polymerase (PARP). Thus, we uncovered a completely new and independent mechanism of mitochondrial nitrosative stress, which is catalyzed by enzymes of the respiratory chain. Then, we concentrated our efforts on the potential role of mitochondrial oxidants in pathological reactions such as diabetes
The effects of negative interest rates on the monetary transmission mechanism – The case of Switzerland
In this article we study how the monetary transmission mechanism (the process through
which monetary policy affects aggregate demand and inflation) alters when the nominal
interest rates become negative, through the case of Switzerland. The results of our models
show that the effectiveness of the interest rate channel of the transmission mechanism
decreases at negative nominal interest rates. However, considering the limits of the
models and the unique factors affecting the monetary transmission in Switzerland, clear
conclusions about the effectiveness of the interest rate channel cannot be made
Balanced Submodular Flows
This paper examines the Balanced Submodular Flow Problem, that is the problem
of finding a feasible submodular flow minimizing the difference between the
flow values along the edges. A min-max formula is given to the problem and an
algorithm is presented to solve it using submodular function
minimizations. Then, these result are extended to the weighted version of the
problem. Finally, the Balanced Integer Submodular Flow Problem is discussed.Comment: 22 pages, 1 figur
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