Functional Grading Between Soft-Magnetic Fe-Co/Fe-Ni Alloys and the Effect on Magnetic and Microstructural Properties.

Producing soft magnetic alloys by additive manufacturing has the potential to overcome cracking and brittle fracture issues associated with conventional thermomechanical processing. Fe-Co alloys exhibit high magnetic saturation but low ductility that makes them difficult to process by commercial methods. Ni-Fe alloys have good ductility and high permeability in comparison to Fe-Co, but they suffer from low magnetic saturation.

Programmable Photoluminescence via Intrinsic and DNA-Fluorophore Association in a Mixed Cluster Heterometallic MOF.

A rapid and facile design strategy to create a highly complex optical tag with programmable, multimodal photoluminescent properties is described. This was achieved via intrinsic and DNA-fluorophore hidden signatures. As a first covert feature of the tag, an intricate novel heterometallic near-infrared (NIR)-emitting mesoporous metal-organic framework (MOF) was designed and synthesized.

Encoding Multilayer Complexity in Anti-Counterfeiting Heterometallic MOF-Based Optical Tags.

Optical tags provide a way to quickly and unambiguously identify valuable assets. Current tag fluorophore options lack the tunability to allow combined methods of encoding in a single material. Herein we report a design strategy to encode multilayer complexity in a family of heterometallic rare-earth metal-organic frameworks based on highly connected nonanuclear clusters.

Antibody Targeted Metal-Organic Frameworks for Bioimaging Applications.

We report on the availability and chemical utility of primary amines within metal-organic frameworks (MOFs) for cell targeting. Primary amine groups represent one of the most versatile chemical moieties for conjugation to biologically relevant molecules, including antibodies and enzymes. Specifically, we used two different chemical conjugations schemes, utilizing the amino functionality on the organic linker: first, carbodiimide chemistry was used to link the primary amine to available carboxyl groups on the protein neutravidin; second, sulfhydryl cross-linking chemistry was used via Traut's reagent scheme.

Towards point of care systems for the therapeutic drug monitoring of imatinib.

Therapeutic drug monitoring is used in the clinical setting in the optimisation of dosages to overcome inter-patient pharmacokinetic variability, increasing efficacy whilst reducing toxicity. Imatinib is a tyrosine kinase inhibitor, displaying large variations in plasma concentrations that impact therapeutic success. As a result, imatinib has been the focus in the development of innovative techniques, aimed at its quantification in plasma.

Insights into the solvent-assisted degradation of organophosphorus compounds by a Zr-based metal-organic framework.

The degradation of a chemical warfare agent simulant using a catalytically active Zr-based metal-organic framework (MOF) as a function of different solvent systems was investigated. Complementary molecular modelling studies indicate that the differences in the degradation rates are related to the increasing size in the nucleophile, which hinders the rotation of the product molecule during degradation. Methanol was identified as an appropriate solvent for non-aqueous degradation applications and demonstrated to support the MOF-based destruction of both sarin and soman.

Covalently Crosslinked Nanogels: An NMR Study of the Effect of Monomer Reactivity on Composition and Structure.

Covalently crosslinked nanogels are widely explored as drug delivery systems and sensors. Radical polymerization provides a simple, inexpensive, and broadly applicable approach for their preparation, although the random nature of the reaction requires careful study of the final chemical composition. We demonstrate how the different reactivities of the monomers influence the total degree of incorporation into the polymer matrix and the role played by the experimental parameters in maximizing polymerization efficiency.

Antibacterial Countermeasures via Metal-Organic Framework-Supported Sustained Therapeutic Release.

Long-term antimicrobial therapies are necessary to treat infections caused by virulent intracellular pathogens, including biothreat agents. Current treatment plans include injectable therapeutics given multiple times daily over a period for up to 8 weeks. Here, we present a metal-organic framework (MOF), zeolitic imidazolate framework-8 (ZIF-8), as a robust platform to support the sustained release of ceftazidime, an important antimicrobial agent for many critical bacterial infections.

Self-Assembled Array of Tethered Manganese Oxide Nanoparticles for the Next Generation of Energy Storage.

Many challenges must be overcome in order to create reliable electrochemical energy storage devices with not only high energy but also high power densities. Gaps exist in both battery and supercapacitor technologies, with neither one satisfying the need for both large power and energy densities in a single device. To begin addressing these challenges (and others), we report a process to create a self-assembled array of electrochemically active nanoparticles bound directly to a current collector using extremely short (2 nm or less) conductive tethers.

HO Enables Convenient Removal of RAFT End-Groups from Block Copolymer Nano-Objects Prepared via Polymerization-Induced Self-Assembly in Water.

RAFT-synthesized polymers are typically colored and malodorous due to the presence of the sulfur-based RAFT end-group(s). In principle, RAFT end-groups can be removed by treating molecularly dissolved copolymer chains with excess free radical initiators, amines, or oxidants. Herein we report a convenient method for the removal of RAFT end-groups from aqueous dispersions of diblock copolymer nano-objects using HO.

Infrared signature of micro-hydration in the organophosphate Sarin: an ab initio study.

The infrared (IR) spectra of micro-hydrated Sarin•(H2O)n clusters containing between one and four explicit waters have been studied using ab initio density functional theory (DFT) methods. The phosphate group P=O bond vibration region (∼1270 to 1290 cm(-1)) revealed the largest frequency variation with hydration, with a frequency red shift reflecting the direct hydrogen bond formation between the P=O of Sarin and water. Small variations to the P-F stretch (∼810 to 815 cm(-1)) and the C-O-P vibrational modes (∼995 to 1004 cm(-1)) showed that the water interactions with these functional groups were minor, and that the structures of Sarin were not extensively perturbed in the hydrated complexes.

National trends in the use of postcardiac arrest therapeutic hypothermia and hospital factors influencing its use.

Background: Therapeutic hypothermia (TH) in cardiac arrest continues to be underused in the United States. A better understanding of its utilization could inform future efforts and policies to improve utilization. This study investigates trends in TH use for in and out-of-hospital cardiac arrest, and hospital factors associated with its use.

A variational approach to the analysis of dissipative electromechanical systems.

We develop a method for systematically constructing Lagrangian functions for dissipative mechanical, electrical, and electromechanical systems. We derive the equations of motion for some typical electromechanical systems using deterministic principles that are strictly variational. We do not use any ad hoc features that are added on after the analysis has been completed, such as the Rayleigh dissipation function.

Heightened efficacy of nitric oxide-based therapies in type II diabetes mellitus and metabolic syndrome.

Type II diabetes mellitus (DM) and metabolic syndrome are associated with accelerated restenosis following vascular interventions due to neointimal hyperplasia. The efficacy of nitric oxide (NO)-based therapies is unknown in these environments. Therefore, the aim of this study is to examine the efficacy of NO in preventing neointimal hyperplasia in animal models of type II DM and metabolic syndrome and examine possible mechanisms for differences in outcomes.

Beneficial effect of a short-acting NO donor for the prevention of neointimal hyperplasia.

Nitric oxide (NO)-based therapies effectively inhibit neointimal hyperplasia in animal models of arterial injury and bypass grafting, but are not available clinically. We created a simple, effective, locally applied NO-eluting therapy to prevent restenosis after vascular procedures. We investigated the efficacy of perivascular delivery of two distinctly different diazeniumdiolate NO donors, 1-[2-(carboxylato)pyrrolidin-1-yl]diazen-1-ium-1,2-diolate (PROLI/NO) (short half-life) and diazeniumdiolated poly(acrylonitrile) (PAN/NO) (long half-life), in powder or gel form (30% poloxamer 407), at inhibiting neointimal hyperplasia using the rat carotid artery injury model.

The importance of calculating absolute rather than relative fracture risk.

The relation between fracture risk and bone mineral density (BMD) is commonly expressed as a multiplicative factor which is said to represent the increase in risk for each standard deviation fall in BMD. This practice assumes that risk increases multiplicatively with each unit fall in bone density, which is not correct. Although odds increase multiplicatively, absolute risk, which lies between 0 and 1, cannot do so though it can be derived from odds by the term Odds/(1+Odds).

Differential regulation of the superoxide dismutase family in experimental aortic aneurysms and rat aortic explants.

Objective: Oxidative stress has been implicated in abdominal aortic aneurysm pathogenesis. This study sought to characterize the relevance of superoxide dismutases (SOD), a family of reactive oxygen catalyzing metalloenzymes, including manganese SOD (MnSOD), copper-zinc SOD (CuZnSOD), and extracellular SOD (EcSOD), in a rodent aortic aneurysm model.

Methods: Male rat infrarenal abdominal aortas were perfused with either saline (control) or porcine pancreatic elastase (6 U/mL).

Targeted deletion of CCR2 impairs deep vein thombosis resolution in a mouse model.

CCR2 is required for monocyte recruitment in many inflammatory processes, as well as conferring Th1 lymphokine responses. Deep vein thrombosis (DVT) resolution represents a specific inflammatory response whereby the thrombus must be dissolved for restoration of blood flow. Using a stasis model of DVT in the mouse, we investigated the role of CCR2 on DVT resolution.

Neutrophils modulate post-thrombotic vein wall remodeling but not thrombus neovascularization.

Early deep venous thrombosis (DVT) resolution is associated with neutrophil (PMN) influx. This study examined the role of PMNs in thrombus neovascularization and vein wall injury after DVT. A rat model of DVT by inferior vena cava (IVC) ligation was performed with control serum or rabbit anti-rat PMN serum administered perioperatively with sacrifice at 2 and 7 days.

Gender differences in rat aortic smooth muscle cell matrix metalloproteinase-9.

Background: A predilection exists for men to develop abdominal aortic aneurysms (AAAs), but the reasons for this gender predisposition are not known. Matrix metalloproteinase-9 (MMP-9) has been implicated in both human and experimental AAAs. This investigation tested the hypothesis that male and female gender differences exist in the production of MMP-9 by rat aortic smooth muscle cells (RASMCs).

Vein wall remodeling after deep vein thrombosis involves matrix metalloproteinases and late fibrosis in a mouse model.

Hypothesis: Deep venous thrombosis (DVT) confers vein wall injury associated with fibrosis and extracellular matrix (ECM) turnover, likely mediated by matrix proteases. This study investigated the expression of proteases and collagen involved in early vein wall remodeling.

Methods: In the mouse, DVT was produced by ligation of the infrarenal inferior vena cava (IVC) or sham operation, and tissue was harvested at 4, 8, and 12 days.

L-selectin-mediated neutrophil recruitment in experimental rodent aneurysm formation.

Background: This investigation tested the hypothesis that L-selectin is important in experimental abdominal aortic aneurysm (AAA) formation in rodents.

Methods And Results: Rat abdominal aortas were perfused with saline (control) or porcine pancreatic elastase and studied on postperfusion days 1, 2, 4, 7, and 14 (n=5 per treatment group per day). Neutrophil (polymorphonucleur leukocyte, PMN) and macrophage counts per high-powered field (HPF) were performed on fixed sections.

Tamoxifen up-regulates catalase production, inhibits vessel wall neutrophil infiltration, and attenuates development of experimental abdominal aortic aneurysms.

Background: Selective estrogen receptor modulators (SERMs), similar to estrogens, possess vasoprotective effects by reducing release of reactive oxygen species. Little is known about the potential effects of SERMs on the pathogenesis of abdominal aortic aneurysms (AAAs). This study's objective was to investigate the growth of experimental AAAs in the setting of the SERM tamoxifen.