‎let $d_{n,m}=big[frac{2n+1-sqrt{17+8(m-n)}}{2}big]$ and‎ ‎$e_{n,m}$ be the graph obtained from a path‎ ‎$p_{d_{n,m}+1}=v_0v_1 cdots v_{d_{n,m}}$ by joining each vertex of‎ ‎$k_{n-d_{n,m}-1}$ to $v_{d_{n,m}}$ and $v_{d_{n,m}-1}$‎, ‎and by‎ ‎joining $m-n+1-{n-d_{n,m}choose 2}$ vertices of $k_{n-d_{n,m}-1}$‎ ‎to $v_{d_{n,m}-2}$‎. ‎zhang‎, ‎liu and zhou [on the maximal eccentric‎ ‎connectivity ind...

Let $G$ be a connected graph on $n$ vertices. $G$ is called tricyclic if it has $n + 2$ edges, and tetracyclic if $G$ has exactly $n + 3$ edges. Suppose $mathcal{C}_n$ and $mathcal{D}_n$ denote the set of all tricyclic and tetracyclic $n-$vertex graphs, respectively. The aim of this paper is to calculate the minimum and maximum of eccentric connectivity index in $mathcal{C}_n$ and $mathcal{D}_n...

The Laplacian spread of a graph is defined to be the difference between the largest eigenvalue and the second smallest eigenvalue of the Laplacian matrix of the graph. In this paper, we investigate Laplacian spread of graphs, and prove that there exist exactly five types of tricyclic graphs with maximum Laplacian spread among all tricyclic graphs of fixed order.

In this paper, we determine the tight upper bound for the number of matchings of connected n-vertex tricyclic graphs. We show that this bound is 13fn−4+16fn−5, where fn be the nth Fibonacci number. We also characterize the n-vertex simple connected tricyclic graph for which the bound is best possible.

Let G be a simple connected graph on n vertices and λ1, λ2, . . . , λn be the eigenvalues of the adjacency matrix of G. The Estrada index of G is defined as EE(G) = n i=1 e λi . LetTn be the class of tricyclic graphs G on n vertices. In this paper, the graphs inTn with themaximal Estrada index is characterized. © 2013 Elsevier B.V. All rights reserved.

The signless Laplacian separator of a graph is defined as the difference between the largest eigenvalue and the second largest eigenvalue of the associated signless Laplacian matrix. In this paper, we determine the maximum signless Laplacian separators of unicyclic, bicyclic and tricyclic graphs with given order.

It is well known that the graph invariant, ‘the Merrifield–Simmons index’ is important one in structural chemistry. The connected acyclic graphs with maximal and minimal Merrifield–Simmons indices are determined by Prodinger and Tichy [H. Prodinger, R.F. Tichy, Fibonacci numbers of graphs, Fibonacci Quart. 20 (1982) 16–21]. The sharp upper and lower bounds for theMerrifield–Simmons indices of u...

background major depressive disorder (mdd) is the most common disorder in our community. hypericum perforatumm, is a herb with a long application history in treating depression. a controlled study to evaluate the effects of this herbal medicine in iran did not exist. objectives this study aimed to assess the effect of hypericum perforatom (perforan), in combination with tricyclic antidepressant...

A concise and stereoselective total synthesis of the clinically relevant tricyclic prostaglandin D2 metabolite (tricyclic-PGDM) methyl ester in racemic form was accomplished eight steps from a readily available known cyclopentene-diol derivative. The features nickel-catalyzed Ueno–Stork-type dicarbofunctionalization to generate two consecutive stereocenters, palladium-catalyzed carbonylative sp...