A fullerene graph is a cubic 3-connected plane graph with (exactly 12) pentagonal faces and hexagonal faces. Let Fn be a fullerene graph with n vertices. A set H of mutually disjoint hexagons of Fn is a sextet pattern if Fn has a perfect matching which alternates on and off each hexagon in H. The maximum cardinality of sextet patterns of Fn is the Clar number of Fn. It was shown that the Clar n...

a fullerene graph is a 3−connected planar graph whose faces are pentagons and hexagons.the clar number of a fullerene is the maximum size of sextet patterns, the sets of disjointhexagons which are all m-alternating for a kekulé structure m of f. an exact formula of clarnumber of some fullerene graphs and a class of carbon nanocones are obtained in this paper.

BACKGROUND The laparoscopic approach has become increasingly incorporated into the development of new surgical procedures. An ever-increasing number of surgeons desire methods that minimize surgical trauma and provide improved cosmetic outcomes. Since 2014, we have performed two-port laparoscopic surgery using a transumbilical multichannel glove port and a 12-mm port. The aim of this study was ...

BACKGROUND The purpose of the study was to evaluate the safety and effects of single-incision laparoscopic anterior resection (SILAR) for sigmoid colon cancer by comparing it with conventional laparoscopic anterior resection (CLAR). METHODS Twenty-four patients who underwent SILAR between April 2010 and July 2011 were case matched 1:2 with patients who underwent CLAR, with respect to age, sex...

OBJECTIVE The clavulanic acid regulatory gene (claR) is in the clavulanic acid biosynthetic gene cluster that encodes ClaR. This protein is a putative regulator of the late steps of clavulanic acid biosynthesis. The aim of this research is the molecular cloning of claR, isolated from the Iranian strain of Streptomyces clavuligerus (S. clavuligerus). MATERIALS AND METHODS In this experimental ...

Many chemical properties of benzenoid hydrocarbons can be understood in terms of the maximum number of mutually resonant hexagons, or Clar number, of the molecules. Hansen and Zheng (1994) formulated this problem as an integer program and conjectured, based on computational results, that solving the linear programming relaxation always yields integral solutions. We prove this conjecture showing...

We show how precision lensing measurements can be obtained through the lensing magnification effect in high redshift 21cm emission from galaxies. Normally, cosmic magnification measurements have been seriously complicated by galaxy clustering. With precise redshifts obtained from 21cm emission line wavelength, one can correlate galaxies at different source planes, or exclude close pairs to elim...

The claR of Streptomyces clavuligerus in the clavulanic acid gene cluster encodes a transcriptional regulator that controls clavulanic acid biosynthesis. The main goal of this study was isolation and molecular detection of the claR gene and its cloning in the Streptomyces specific vector (pMA:: hyg). By cinsideration of the claR gene’s start codon, the specific primers were designed. After geno...