University of Minho

About: University of Minho is a education organization based out in Braga, Portugal. It is known for research contribution in the topics: Context (language use) & Population. The organization has 10585 authors who have published 34736 publications receiving 732436 citations. The organization is also known as: Universidade do Minho & UMinho.

Conductance quantization in mesoscopic graphene

Abstract: Using a generalized Landauer approach we study the nonlinear transport in mesoscopic graphene with zigzag and armchair edges We find that for clean systems, the low-bias low-temperature conductance, $G$, of an armchair edge system is quantized as $G∕\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{t}=4n{e}^{2}∕h$, whereas for a zigzag edge the quantization changes to $G∕\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{t}=4(n+1∕2){e}^{2}∕h$, where $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{t}$ is the transmission probability and $n$ is an integer We also study the effects of a nonzero bias, temperature, and magnetic field on the conductance The magnetic field dependence of the quantization plateaus in these systems is somewhat different from the one found in the two-dimensional electron gas due to a different Landau level quantization

Role of monocarboxylate transporters in human cancers: state of the art

Abstract: Monocarboxylate transporters (MCTs) belong to the SLC16 gene family, presently composed by 14 members. MCT1-MCT4 are proton symporters, which mediate the transmembrane transport of pyruvate, lactate and ketone bodies. The role of MCTs in cell homeostasis has been characterized in detail in normal tissues, however, their role in cancer is still far from understood. Most solid tumors are known to rely on glycolysis for energy production and this activity leads to production of important amounts of lactate, which are exported into the extracellular milieu, contributing to the acidic microenvironment. In this context, MCTs will play a dual role in the maintenance of the hyper-glycolytic acid-resistant phenotype of cancer, allowing the maintenance of the high glycolytic rates by performing lactate efflux, and pH regulation by the co-transport of protons. Thus, they constitute attractive targets for cancer therapy, which have been little explored. Here we review the literature on the role of MCTs in solid tumors in different locations, such as colon, central nervous system, breast, lung, gynecologic tract, prostate, stomach, however, there are many conflicting results and in most cases there are no functional studies showing the dependence of the tumors on MCT expression and activity. Additional studies on MCT expression in other tumor types, confirmation of the results already published as well as additional functional studies are needed to deeply understand the role of MCTs in cancer maintenance and aggressiveness.