1H‐decoupling and Isotopic Labeling for the Measurement of the Longitudinal Relaxation Time of Hyperpolarized 13C‐Methylenes in Choline Analogs

The T₁ of a hyperpolarized site in solution is a key parameter that determines the time‐window in which its NMR signals are observable. For ¹³C sites adjacent to protons, ¹H‐decoupling has been shown to increase the hyperpolarized signal resolution and SNR. Additionally, polarization transfer to protons has shown utility in increasing the sensitivity of detection. However, ¹H‐decoupling could lead to a change in the decay rate of a hyperpolarized ¹³C site. Here we tested this possible effect in a case where the protons are directly bound to an sp³ hyperpolarized ¹³C site (using [1,2‐¹³C₂]choline) and ¹H‐decoupling was applied continuously throughout the hyperpolarized decay measurement. We found that ¹H‐decoupling did not lead to any significant changes in the ¹³C polarization decay time but did result in the expected collapse of J‐coupling and produced sharper signals. This result suggested that ¹H‐decoupling did not affect the decay rate of hyperpolarized sp^{3 13}C sites. The deuterium‐substitution approach (using [1,1,2,2‐D₄,1‐¹³C]choline) showed a dramatic prolongation of T₁. Upper bounds on the T₁ of all investigated sites were calculated.     

Magnetic Assembly of a Multifunctional Guidance Conduit for Peripheral Nerve Repair

Nerve growth conduits are designed to support and promote axon regeneration following nerve injuries. Multifunctionalized conduits with combined physical and chemical cues, are a promising avenue aimed at overcoming current therapeutic barriers. However, the efficacious assembly of conduits that promote neuronal growth remains a challenge. Here, a biomimetic regenerative gel is developed, that integrates physical and chemical cues in a biocompatible “one pot reaction” strategy. The collagen gel is enriched with magnetic nanoparticles coated with nerve growth factor (NGF). Then, through a remote magnetic actuation, highly aligned fibrillar gel structure embedded with anisotropically distributed coated nanoparticles, combining multiple regenerating strategies, is obtained. The effects of the multifunctional gels are examined in vitro, and in vivo in a 10-mm rat sciatic nerve injury model. The magneto-based therapeutic conduits demonstrate oriented and directed axonal growth, and improve nerve regeneration in vivo. The study of multifunctional guidance scaffolds that can be implemented efficiently and remotely provides the foundation to a novel therapeutic approach to overcome current medical obstacles for nerve injuries.     

Eosinophil-Derived Neurotoxin (EDN/RNase 2) and the Mouse Eosinophil-Associated RNases (mEars): Expanding Roles in Promoting Host Defense

The eosinophil-derived neurotoxin (EDN/RNase2) and its divergent orthologs, the mouse eosinophil-associated RNases (mEars), are prominent secretory proteins of eosinophilic leukocytes and are all members of the larger family of RNase A-type ribonucleases. While EDN has broad antiviral activity, targeting RNA viruses via mechanisms that may require enzymatic activity, more recent studies have elucidated how these RNases may generate host defense via roles in promoting leukocyte activation, maturation, and chemotaxis. This review provides an update on recent discoveries, and highlights the versatility of this family in promoting innate immunity.     

Potenziale und Grenzen der Sekundärrohstoffgewinnung – Ergebnisse der r4-Begleitforschung

The socio-economic and ecological impacts of selected projects of the BMBF funding program “r⁴ – Innovative Technologies for Resource Efficiency – Research for the Provision of Raw Materials of Strategic Economic Importance” are presented. Many, but not all, research projects indicate a potential improvement of the supply situation in Germany. In some cases, the provision of secondary raw materials is unprofitable or ecologically detrimental. These cases require a balancing between security of supply and other economic and ecological objectives.     

The combined influence of Mg and Ca on microstructural evolution of alumina

The solubility limits of Ca and Mg co-doped in alumina at 1600°C were determined by equilibrating alumina saturated with Ca and Mg. This resulted in the formation of MgAl₂O₄ (Mg spinel), CaO·6Al₂O₃ (CA6), Ca₂Mg₂Al₂₈O₄₆ (CAM-II), and alumina grains saturated with Mg and Ca. Under these conditions, the amount of Ca and Mg in the alumina grains represents the solubility limits. The solubility limits were measured using a fully standardized wavelength dispersive spectrometer mounted on a scanning electron microscope. In the co-doped state, the solubility limit of Ca in alumina was 32 ± 13 ppm, and the solubility limit of Mg in alumina was 210 ± 43 ppm. The presence of Ca results in an increase of the solubility limit of Mg in alumina from 132 to 210 ppm, suggesting that the increased Mg in solution results in more Mg excess at the alumina grain boundaries, thus contributing to a decreased grain-boundary mobility by solute-drag.     

Combinatorial Optimization and Performance Analysis of a Multi-arm Cartesian Robotic Fruit Harvester—Extensions of Graph Coloring

A mobile melon robotic harvester consisting of multiple Cartesian manipulators, each with three degrees of freedom, is being developed. In order to design an optimal robot in terms of number of arms, manipulator capabilities, and robot speed, a method of allocating the fruits to be picked by each manipulator in a way that yields the maximum harvest has been developed. Such a method has already been devised for a multi-arm robot with 2DOF each. The maximum robotic harvesting problem was shown there to be an example of the maximum k-colorable subgraph problem (MKCSP) on an interval graph. However, for manipulators with 3DOF, the additional longitudinal motion results in variable intervals. To overcome this issue, we devise a new model based on the color-dependent interval graph (CDIG). This enables the harvest by multiple robotic arms to be modeled as a modified version of the MKCSP. Based on previous research, we develop a greedy algorithm that solves the problem in polynomial time, and prove its optimality using induction. As with the multi-arm 2DOF robot, when simulated numerous times on a field of randomly distributed fruits, the algorithm yields a nearly identical percentage of fruit harvested for given robot parameters. The results of the probabilistic analysis developed for the 2DOF robot was modified to yield a formula for the expected harvest ratio of the 3DOF robot. The significance of this method is that it enables selecting the most efficient actuators, number of manipulators, and robot forward velocity for maximal robotic fruit harvest.     

2011 CAV award announcement

The 2011 CAV (Computer-Aided Verification) Award was presented on July 17, 2011 at the 23rd annual CAV conference in Snowbird, Utah to Thomas Ball and Sriram Rajamani of Microsoft Research for their contributions to software model checking, specifically the development of the SLAM/SDV software model checker, which successfully demonstrated computer-aided verification techniques on real programs.     

Residual tumor after laser ablation of human non-small-cell lung cancer demonstrated by ex vivo staining: correlation with invasive temperature measurements

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Histology is the gold standard for confirming thermally induced necrosis. Generally, however, no specimen is obtained from thermal ablation therapy for pathological examination. The aim of this study was to provide evidence for the relationship between temperatures reached and resulting tissue coagulation during laser ablation in a near-physiological ex vivo lung tumor model by combining viability staining and direct temperature measurement.