Search results for "equipment and supplies"
showing 10 items of 483 documents
Molecular Magnetic Materials from Polyoxometalates
1994
The significance of polyoxometalates in the field of molecular magnetism is discussed. We show that this kind of inorganic complexes provides remarkable examples for the study of the exchange interactions in clusters. On the other hand, we examine the possibility of using these metal oxide anions as magnetic components of molecular materials containing organic tetrathiafulvalenes as electron donor molecules.
The Missing Link in the Magnetism of Hybrid Cobalt Layered Hydroxides: The Odd‐Even Effect of the Organic Spacer
2021
A dramatic change in the magnetic behaviour, which solely depends on the parity of the organic linker molecules, has been found in a family of layered CoII hydroxides covalently functionalized with dicarboxylic molecules. These layered hybrid materials have been synthesized at room temperature using a one-pot procedure through the epoxide route. While hybrids connected by odd alkyl chains exhibit coercive fields (Hc) below ca. 3500 Oe and show spontaneous magnetization at temperatures (TM) below 20 K, hybrids functionalized with even alkyl chains behave as hard magnets with Hc>5500 Oe and display a TM higher than 55 K. This intriguing behaviour was studied by density functional theory with …
Surface Chemistry Controls Magnetism in Cobalt Nanoclusters
2016
Magnetic properties of Co13 and Co55 nanoclusters, passivated by surface ligand shells that exhibit varying electronic interactions with the metal, are studied using density functional theory. The calculations show that the chemical nature of the bond between the ligand and the metal core (X-type or L-type) impacts the total magnetic moment of Co nanoclusters dramatically. Furthermore, the chemical identity of the ligand within each binding motif then provides a fine handle on the exhibited magnetic moment of the cluster. Thus, ligand shell chemistry is predicted to not only stabilize Co nanoclusters, but provide a powerful approach to control their magnetic properties, which combined enabl…
Geostatistical 3-dimensional integration of measurements of soil magnetic susceptibility.
2010
In soil magnetometry, two types of measurements are usually performed. The first type is measurements performed on the soil surface, frequently using an MS2D sensor. The second type includes measurements of magnetic susceptibility carried out in the soil profile, usually to a depth of about 30 cm. Up to now, such measurement results were analyzed separately. However, it is possible and advantageous to integrate these two types of measurements. The goal of the study was to integrate measurements of magnetic susceptibility performed on the soil surface and in the soil profile. More specifically, the goal was to obtain 3-dimensional spatial distributions of magnetic susceptibility of the topso…
Residential magnetic fields as a risk factor for childhood acute leukaemia: Results from a German population-based case-control study
2001
Our objective was to investigate whether exposure to residential power-frequency (50 Hz) magnetic fields above 0.2 μT increases a child's risk of leukaemia and to confirm or reject a finding from a previous German study on this topic, which reported increased leukaemia risk with exposure to stronger magnetic fields during the night. A population-based case-control study was used, covering the whole of the former West Germany. Residential magnetic fields were measured over 24 hr for 514 children with acute leukaemia identified by the German Childhood Cancer Registry and 1,301 control children taken from population registration files. Magnetic fields above 0.2 μT were relatively rare in Germa…
Polymeric Nanocarriers for Magnetic Targeted Drug Delivery: Preparation, Characterization, and in Vitro and in Vivo Evaluation
2013
In this paper the preparation of magnetic nano- carriers (MNCs), containing superparamagnetic domains, is reported, useful as potential magnetically targeted drug delivery systems. The preparation of MNCs was performed by using the PHEA-IB-p(BMA) graft copolymer as coating material through the homogenization−solvent evaporation method. Magnetic and nonmagnetic nanocarriers containing flutamide (FLU-MNCs) were prepared. The prepared nanocarriers have been exhaustively characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and magnetic measurements. Biological evaluation was performed by in vitro cytotoxicity and cell uptake tests and in vivo biodistribution …
Intramural delivery of Sirolimus prevents vascular remodeling following balloon injury
2005
Abstract Objective. Several studies have demonstrated that Sirolimus-eluting stents reduce restenosis in patients with coronary artery disease. Here, we tested whether direct delivery of Sirolimus into the vessel wall during balloon angioplasty can modify vascular remodeling over several weeks. Methods and Results. During angioplasty of the rabbit iliac artery we administered an intramural infusion of Sirolimus or its vehicle directly through a balloon catheter into the vessel wall. After 3 weeks neointimal formation was decreased (0.71 ± 0.1 vs. 1.4 ± 0.12 intima/media ratio), and this process was attributed to the inhibitory properties of Sirolimus on ECM deposition and smooth muscle cell…
Venous thromboembolism in metastatic urothelial carcinoma or variant histologies: incidence, associative factors, and effect on survival.
2016
Venous thromboembolism (VTE) is common in cancer patients. However, little is known about VTE risk in metastatic urothelial carcinoma or variant histologies (UC/VH). We sought to characterize the incidence, associative factors, including whether various chemotherapy regimens portend different risk, and impact of VTE on survival in metastatic UC/VH patients. Patients diagnosed with metastatic UC/VH from 2000 to 2013 were included in this multicenter retrospective, international study from 29 academic institutions. Cumulative and 6-month VTE incidence rates were determined. The association of first-line chemotherapy (divided into six groups) and other baseline characteristics on VTE were anal…
Non-viral VEGF(165) gene therapy--magnetofection of acoustically active magnetic lipospheres ('magnetobubbles') increases tissue survival in an overs…
2008
Abstract Adenoviral transduction of the VEGF gene in an oversized skin flap increases flap survival and perfusion. In this study, we investigated the potential of magnetofection of magnetic lipospheres containing VEGF165-cDNA on survival and perfusion of ischemic skin flaps and evaluated the method with respect to the significance of applied magnetic field and ultrasound. We prepared perfluoropropane-filled magnetic lipospheres (‘magnetobubbles’) from Tween60-coated magnetic nanoparticles, Metafectene, soybean-oil and cDNA and studied the effect in an oversized random-pattern-flap model in the rats (n= 46). VEGF-cDNA-magnetobubbles were administered under a magnetic field with simultaneousl…
EMG-guided percutaneous placement of cement-augmented pedicle screws for osteoporotic thoracolumbar burst fractures
2017
Background: Percutaneous techniques have increasingly gained popularity in recent years. The application of technological innovation, including neuromonitoring techniques, has the potential to increase the safety and efficacy of these procedures. Methods: Thirty patients suffering from osteoporotic dorsolumbar burst fracture were prospectively enrolled in this study. The patients underwent percutaneous fenestrated pedicle screw fixation augmented with polymethylmethacrylate (PMMA) injection. A novel surgeon-dedicated neuromonitoring device was used in order to increase the safety and the accuracy of the screw insertion. A second group of 30 patients who did not undergo neuromonitoring durin…