An incidence of an undirected graph G is a pair (v, e) where v is a vertex of G and e an edge of G incident with v. Two incidences (v, e) and (w, f) are adjacent if one of the following holds: (i) v = w, (ii) e = f or (iii) vw = e or f . An incidence coloring of G assigns a color to each incidence of G in such a way that adjacent incidences get distinct colors. In 2012, Yang [15] proved that ev...

For a simple connected graph G with n-vertices having Laplacian eigenvalues μ1, μ2, . . . , μn−1, μn = 0, and signless Laplacian eigenvalues q1, q2, . . . , qn, the Laplacian-energy-like invariant(LEL) and the incidence energy (IE) of a graph G are respectively defined as LEL(G) = ∑n−1 i=1 √ μi and IE(G) = ∑n i=1 √ qi. In this paper, we obtain some sharp lower and upper bounds for the Laplacian...

OBJECTIVE To assess the effects of winter/summer school breaks on occurrences of influenza-like illness (ILI). METHODS We jointly analysed ILI surveillance data with the timing of school breaks in a temperate district in Beijing, China from 2008 to 2015. ILI incidence rate ratios (IRRs) of schoolchildren (5-14 and 15-24 years of age) to adults (25-59 and >60 years of age) were used to measure...

results results showed that naderi and havashenasi stations had the highest and the lowest sulfur and nitrogen dioxide concentrations, respectively during 2012. maximum annual concentrations of sulfur and nitrogen dioxide were 173 and 58 μg/m3, respectively, which observed during winter 2012. approximately 5.6% of the respiratory mortality and copd cases happened when the sulfur and nitrogen di...

background: our knowledge regarding the epidemiology of pancreatobiliary cancers in iran is limited. this study presents the first population-based report on pancreatobiliary cancers performed in five provinces of iran. materials andmethods: data used in this study were retrieved from population-based cancer registries in five provinces of iran (gilan, mazandaran, golestan, ardabil and kerman) ...

background: human immunodeficiency virus (hiv) makes infected cases prone to opportunistic infections like tuberculosis (tb) due to impaired immunity of the body, especially multi drug resistant (mdr) ones which are a major concern. with hiv outbreak starting late in the 20th century, the international health community is observing a huge rise in the incidence of this complex disease. herein, w...

Leprosy is a neglected disease. The insidious onset of leprosy results in its late diagnosis and therefore the spread of the disease. Characterization of leprosy in areas with higher risk and collection of enough information about these spots to adopt more effective controlling measures are of great importance. In the present study, data for every patient who either referred to the health care ...

Background: Common cancers such as colon, breast, and lung cancer are increasing in developing countries. Objective: This study was conducted to determine 10-year trends and changes in common cancers in patients from a referral hospital in Tehran, Iran. Methods: This cross-sectional study investigated a study population comprising colon, stom...

the missing of any tooth is due to undeveloped dental lamina that possible is caused by genetic factors such as ectodermal dysplasia,local infection and systemic diseases.in some cases,the lack of teeth is so wide that causes undevelopment in all premanent teeth which is known as comlete anodontia.the lack of lateral incisors causes speech defect,difficulty in breathing,spacing in other teeth,d...

Background: Cancer as the second leading cause of death following cardiovascular diseases has always been a threat to human life and due to its peculiar nature and lack of a favorable treatment, it is considered as a research priority in all communities. Understanding the geographical distribution of the incidence of various tumors, constitutes the first step in health and treatment planning. T...