Hexafluoropropylene oxide trimer acid,a perfluorooctanoic acid alternative,induces cardiovascular toxicity in zebrafish embryos

As an increasingly used alternative to perfluorooctanoic acid(PFOA),hexafluoropropylene oxide trimer acid(HFPO-TA)has been widely detected in global water environments.However,little is known regarding its toxic effects on cardiovascular development.Here,zebrafish embryos were treated with egg water containing 0,60,120,or 240 mg/L HFPO-TA.Results showed that HFPO-TA treatment led to a significant reduction in both larval survival percentage and heart rate.Furthermore,HFPO-TA exposure caused severe pericardial edema and elongation of the sinus venous to bulbus arteriosus distance(SV-BA)in Tg(myl7:GFP)transgenic larvae,disrupting the expression of genes involved in heart development and thus causing abnormal heart looping.Obvious sprouting angiogenesis was observed in the 120 and 240 mg/L exposed Tg(fli:GFP)transgenic larvae.HFPO-TA treatment also impacted the mRNA levels of genes involved in the vascular endothelial growth factor(VEGF)pathway and embryonic vascular development.HFPO-TA exposure significantly decreased erythrocyte number in Tg(gata1:DsRed)transgenic embryos and influenced gene expression associated with the heme metabolism pathway.HFPO-TA also induced oxidative stress and altered the transcriptional levels of genes related to cell cycle and apoptosis,inhibiting cell proliferation while promoting apoptosis.Therefore,HFPO-TA exposure may induce abnormal development of the cardiovascular and hematopoietic systems in zebrafish embryos,suggesting it may not be a suitable or safe alternative for PFOA.

Cost Edge-Coloring of a Cactus

Let C be a set of colors, and let ?be an integer cost assigned to a color c in C. An edge-coloring of a graph ?is assigning a color in C to each edge ?so that any two edges having end-vertex in common have different colors. The cost ?of an edge-coloring f of G is the sum of costs ?of colors ?assigned to all edges e in G. An edge-coloring f of G is optimal if ?is minimum among all edge-colorings of G. A cactus is a connected graph in which every block is either an edge or a cycle. In this paper, we give an algorithm to find an optimal edge- ??coloring of a cactus in polynomial time. In our best knowledge, this is the first polynomial-time algorithm to find an optimal edge-coloring of a cactus.

A Dynamic Programming Algorithm for the Ridersharing Problem Restricted with Unique Destination and Zero Detour on Trees

We deal with the problem of sharing vehicles by individuals with similar itineraries which is to find the minimum number of drivers, each of which has a vehicle capacity and a detour to realize all trips. Recently, Gu et al. showed that the problem is NP-hard even for star graphs restricted with unique destination, and gave a polynomial-time algorithm to solve the problem for paths restricted with unique destination and zero detour. In this paper we will give a dynamic programming algorithm to solve the problem in polynomial time for trees restricted with unique destination and zero detour. In our best knowledge it is a first polynomial-time algorithm for trees.

HYPERCYCLIC MULTIPLICATION COMPOSITION OPERATORS ON WEIGHTED BANACH SPACE

This paper characterizes some sufficient and necessary conditions for the hypercyclicity of multiples of composition operators on Hlog,0∞.