94 research outputs found
Transmission Electron Microscopic Morphological Study and Flow Cytometric Viability Assessment of Acinetobacter baumannii
Imprimitive symmetric graphs with cyclic blocks
AbstractLet Γ be a graph admitting an arc-transitive subgroup G of automorphisms that leaves invariant a vertex partition B with parts of size v≥3. In this paper we study such graphs where: for B,C∈B connected by some edge of Γ, exactly two vertices of B lie on no edge with a vertex of C; and as C runs over all parts of B connected to B these vertex pairs (ignoring multiplicities) form a cycle. We prove that this occurs if and only if v=3 or 4, and moreover we give three geometric or group theoretic constructions of infinite families of such graphs
UCP2 Inhibits ROS-Mediated Apoptosis in A549 under Hypoxic Conditions
The Crosstalk between a tumor and its hypoxic microenvironment has become increasingly important. However, the exact role of UCP2 function in cancer cells under hypoxia remains unknown. In this study, UCP2 showed anti-apoptotic properties in A549 cells under hypoxic conditions. Over-expression of UCP2 in A549 cells inhibited reactive oxygen species (ROS) accumulation (P<0.001) and apoptosis (P<0.001) compared to the controls when the cells were exposed to hypoxia. Moreover, over-expression of UCP2 inhibited the release of cytochrome C and reduced the activation of caspase-9. Conversely, suppression of UCP2 resulted in the ROS generation (P = 0.006), the induction of apoptosis (P<0.001), and the release of cytochrome C from mitochondria to the cytosolic fraction, thus activating caspase-9. These data suggest that over-expression of UCP2 has anti-apoptotic properties by inhibiting ROS-mediated apoptosis in A549 cells under hypoxic conditions
Hamiltonicity of 3-arc graphs
An arc of a graph is an oriented edge and a 3-arc is a 4-tuple of
vertices such that both and are paths of length two. The
3-arc graph of a graph is defined to have vertices the arcs of such
that two arcs are adjacent if and only if is a 3-arc of
. In this paper we prove that any connected 3-arc graph is Hamiltonian, and
all iterative 3-arc graphs of any connected graph of minimum degree at least
three are Hamiltonian. As a consequence we obtain that if a vertex-transitive
graph is isomorphic to the 3-arc graph of a connected arc-transitive graph of
degree at least three, then it is Hamiltonian. This confirms the well known
conjecture, that all vertex-transitive graphs with finitely many exceptions are
Hamiltonian, for a large family of vertex-transitive graphs. We also prove that
if a graph with at least four vertices is Hamilton-connected, then so are its
iterative 3-arc graphs.Comment: in press Graphs and Combinatorics, 201
Transcriptional Responses of Different Brain Cell Types to Oxygen Decline
Brain hypoxia is associated with a wide range of physiological and clinical conditions. Although oxygen is an essential constituent of maintaining brain functions, our understanding of how specific brain cell types globally respond and adapt to decreasing oxygen conditions is incomplete. In this study, we exposed mouse primary neurons, astrocytes, and microglia to normoxia and two hypoxic conditions and obtained genome-wide transcriptional profiles of the treated cells. Analysis of differentially expressed genes under conditions of reduced oxygen revealed a canonical hypoxic response shared among different brain cell types. In addition, we observed a higher sensitivity of neurons to oxygen decline, and dissected cell type-specific biological processes affected by hypoxia. Importantly, this study establishes novel gene modules associated with brain cells responding to oxygen deprivation and reveals a state of profound stress incurred by hypoxia
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