In the past Pb2+ has been used in many industries, including gasoline, piping, toys, paints, and more. The use of lead has led to a natural increase of lead concentration in the environment especially in air and water. According to the U.S. CDC “no level of lead in blood is considered safe.” Exposure to very low amounts of lead can cause several health complications including developmental and neurological disorders. Over the past several years an emphasis has been placed in developing systems that can detect lead at a very low concentration. A great deal of work has been accomplished in the development of Pb2+ sensors that can not only detect but also quantify the amount and in some cases in the presence of other metal ions. Herein, we describe current regulations, mode of exposure and recent development of sensing techniques.

Invited for the cover of this issue is the group of Partha Basu at Duquesne University. The cover image shows the various sources of contamination of water by lead and the detection of Pb2+ by a fluorescent sensor called Leadglow.

The cover picture shows the ratiometric detection of Pb2+ with a fluorescent sensor Leadglow. Within the last decade many advances in Pb2+ detection have been made, ranging from small organic molecule detection to large DNAzymes. The background pictorially describes a simple water cycle, indicating routes for Pb2+ contamination. Details are presented in the Microreveiw by K. Deibler and P. Basu on

The mitogen-activated protein kinase signaling cascade is conserved across eukaryotes from yeast to humans, where it plays a central role regulating activities including proliferation, differentiation, and stress responses. This pathway propagates external stimuli through a series of phosphorylation events, allowing external signals to influence metabolic and transcriptional activities. Within the cascade, MEK, or MAP2K, enzymes occupy a molecular crossroads situated immediately upstream to significant signal divergence and cross-talk. One such kinase, MAP2K7, also known as MEK7 and MKK7, is a protein of great interest in the molecular pathophysiology underlying pediatric T-cell acute lymphoblastic leukemia. Herein, we describe the rational design, synthesis, evaluation, and optimization of a novel class of irre-versible MAP2K7 inhibitors. With a streamlined one-pot synthesis, favorable in vitro potency and selectivity, as well as promising cellular activity, this novel class of compounds wields promise as a powerful tool in the study of pediatric T-ALL