Matthew Allen

Department of Chemistry, Wayne State Michigan 48202, USA. E-mail: mallen@chem Department of Molecular Physiology and Bi Baylor Plaza, Houston, Texas 77030, USA. E Department of Neurosurgery, Henry Ford H 48202, USA Integrative Molecular and Biomedical Scien TX 77030, USA Department of Pediatrics, Texas Children's College of Medicine, Houston, TX 77030, US † Electronic supplementary information 1562331. For ESI and crystallographic dat DOI: 10.1039/c7sc03142d Cite this: Chem. Sci., 2017, 8, 8345

Considerable research effort has focused on the use of responsive imaging probes that change imaging properties upon reacting with oxygen because hypoxia is relevant to diagnosing, treating, and monitoring diseases. One promising class of compounds for oxygen-responsive imaging is Eu-containing complexes because the Eu redox couple enables imaging with multiple modalities including magnetic resonance and photoacoustic imaging. The use of Eu requires care in handling to avoid unintended oxidation during synthesis and characterization. This review describes recent advances in the field of imaging agents based on discrete Eu-containing complexes with specific focus on the synthesis, characterization, and handling of aqueous Eu-containing complexes.

The Euredox couple provides a convenient design platform for responsiveOsensors for magnetic resonance imaging (MRI). Specifically the Euion providescontrast enhancement under hypoxic conditions in tissues, whereas, under normoxia, the Euion can produce contrast from chemical exchange saturation transfer in MRI. The oxidative stability of the Euredox couple for a series of tetraaza macrocyclic complexes was investigated in this work using cyclic voltammetry. A series of Eu-containing cyclen-based macrocyclic complexes revealed positive shifts in the Euredox potentials with each replacement of a carboxylate coordinating arm of the ligand scaffold with glycinamide pendant arms. The data obtained reveal that the complex containing four glycinamide coordinating pendant arms has the highest oxidative stability of the series investigated.

Eu(II)-containing materials have unique luminescence, redox, and magnetic properties that have potential applications in optoelectronics, sensors, and imaging. Here, we report the synthesis and characterization of Eu(II)-containing aza-222 cryptate that displays yellow luminescence and a quantum yield of 26% in aqueous media. The crystal structure reveals a staggered hula-hoop geometry. Both solid-state and solution-phase data are presented that indicate that the high quantum yield is a result of the absence of OH oscillators in the inner sphere of the complex. We expect that Eu(II)-containing aza-222 cryptate is a step toward Eu(II)-containing luminescent materials that can be used in a variety of applications including biological imaging.

A three-step route was used to synthesize 1,7-bis(t-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane (DO2A-t-Bu ester) from 1,4,7,10-tetraazacyclododecane (cyclen). The overall time of reaction was reduced from a combined ~56 h to 2.3 h with an overall yield comparable to previously reported methods.

The suppressive effects of bisphosphonates (BPs) on bone remodeling are clear yet there is conflicting data concerning the effects of BPs on modeling (specifically formation modeling on the periosteal surface). The normal periosteal expansion that occurs during aging has significant benefits to maintaining/improving the bones' mechanical properties and thus it is important to understand whether BPs affect this bone surface. Therefore, the purpose of this study was to determine the effects of BPs on periosteal bone formation modeling induced by ovariectomy (OVX) and mechanical loading. Six-month-old Sprague-Dawley OVX rats (n=60; 12/group) were administered vehicle, risedronate, alendronate, or zoledronate at doses used clinically for treatment of post-menopausal osteoporosis. Three weeks after initiating BP treatment, all animals underwent in vivo ulnar loading of the right limb every other day for 1 week (3 total sessions). Periosteal surface mineral apposition rate, mineralizing surface, and bone formation rate were determined at the mid-diaphysis of both loaded (right) and non-loaded (left) ulnae. There was no significant effect of any of the BPs on periosteal bone formation parameters compared to VEH-treated animals in the non-loaded limb, suggesting that BP treatment does not compromise the normal periosteal expansion associated with estrogen loss. Mechanical loading significantly increased BFR in the loaded limb compared to the non-loaded limb in all BP-treated groups, with no difference in the magnitude of this effect among the various BPs. Collectively, these data show that BP treatment, at doses comparable to those used for treatment of post-menopausal osteoporosis, (1) does not alter the periosteal formation activity that occurs in the absence of estrogen and (2) allows normal stimulation of periosteal bone formation in response to the anabolic stimulation of mechanical loading.

The Grid2003 Project has deployed a multivirtual organization, application-driven grid laboratory (" Grid3") that has sustained for several months the production-level services required by physics experiments of the Large Hadron Collider at CERN (ATLAS and CMS), the Sloan Digital Sky Survey project, the gravitational wave search experiment LIGO, the BTeV experiment at Fermilab, as well as applications in molecular structure analysis and genome analysis, and computer science research projects in such areas as job and data ...

The Grid2003 Project has deployed a multivirtual organization, application-driven grid laboratory (" Grid3") that has sustained for several months the production-level services required by physics experiments of the Large Hadron Collider at CERN (ATLAS and CMS), the Sloan Digital Sky Survey project, the gravitational wave search experiment LIGO, the BTeV experiment at Fermilab, as well as applications in molecular structure analysis and genome analysis, and computer science research projects in such areas as job and data ...