238 research outputs found
Exponents of Jacobians of Graphs and Regular Matroids
Let G be a finite undirected multigraph with no self-loops. The Jacobian Jac (G) is a finite abelian group associated with G whose cardinality is equal to the number of spanning trees of G. There are only a finite number of biconnected graphs G such that the exponent of Jac (G) equals 2 or 3. The definition of a Jacobian can also be extended to regular matroids as a generalization of graphs. We prove that there are finitely many connected regular matroids M such that Jac (M) has exponent 2 and characterize all such matroids
Involvement of the JNK/FOXO3a/Bim Pathway in Neuronal Apoptosis after Hypoxic-Ischemic Brain Damage in Neonatal Rats.
c-Jun N-terminal kinase (JNK) plays a key role in the regulation of neuronal apoptosis. Previous studies have revealed that forkhead transcription factor (FOXO3a) is a critical effector of JNK-mediated tumor suppression. However, it is not clear whether the JNK/FOXO3a pathway is involved in neuronal apoptosis in the developing rat brain after hypoxia-ischemia (HI). In this study, we generated an HI model using postnatal day 7 rats. Fluorescence immunolabeling and Western blot assays were used to detect the distribution and expression of total and phosphorylated JNK and FOXO3a and the pro-apoptotic proteins Bim and CC3. We found that JNK phosphorylation was accompanied by FOXO3a dephosphorylation, which induced FOXO3a translocation into the nucleus, resulting in the upregulation of levels of Bim and CC3 proteins. Furthermore, we found that JNK inhibition by AS601245, a specific JNK inhibitor, significantly increased FOXO3a phosphorylation, which attenuated FOXO3a translocation into the nucleus after HI. Moreover, JNK inhibition downregulated levels of Bim and CC3 proteins, attenuated neuronal apoptosis and reduced brain infarct volume in the developing rat brain. Our findings suggest that the JNK/FOXO3a/Bim pathway is involved in neuronal apoptosis in the developing rat brain after HI. Agents targeting JNK may offer promise for rescuing neurons from HI-induced damage
Experimental topological quantum computing with electric circuits
The key obstacle to the realization of a scalable quantum computer is
overcoming environmental and control errors. Topological quantum computation
has attracted great attention because it has emerged as one of the most
promising approaches to solving these problems. Various theoretical schemes for
building topological quantum computation have been proposed. However,
experimental implementation has always been a great challenge because it has
proved to be extremely difficult to create and manipulate topological qubits in
real systems. Therefore, topological quantum computation has not been realized
in experiments yet. Here, we report the first experimental realization of
topological quantum computation with electric circuits. Based on our proposed
new scheme with circuits, Majorana-like edge states are not only observed
experimentally, but also T junctions are constructed for the braiding process.
Furthermore, we demonstrate the feasibility of topological quantum computing
through a set of one- and two-qubit unitary operations. Finally, our
implementation of Grover's search algorithm demonstrates that topological
quantum computation is ideally suited for such tasks
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