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Silicone breast implants are used for breast augmentation and breast reconstruction. The issues of concern associated with such implants are: (a) the quality control of each implant before implantation, and (b) the detection of implant bleeding after implantation. We have studied the use of the Nuclear Magnetic Resonance-MObile Universal Surface Explorer (NMR-MOUSE) for the nondestructive testing of (a) the quality of implant shells, and (b) changes in implant gel due to leakage of body fluid into the implant. Depth profiles measured nondestructively through implant shells at different positions of each implant by the Profile NMR-MOUSE assured good reproducibility of the quality and thickness of different shell layers. The leakage of implants upon rupture was mimicked by observing changes in the transverse NMR relaxation time of the implant gel upon ingress of physiological saline solution and safflower oil through the rupture. Results demonstrate that nondestructive testing with unilateral NMR is a potential method for use in the quality control of implants and for the screening of implants for rupture after implantation. 相似文献
84.
Let p be a prime and let b be a positive integer. If a (v, k, λ, n) difference set D of order n = p b exists in an abelian group with cyclic Sylow p-subgroup S, then \({p\in\{2,3\}}\) and |S| = p. Furthermore, either p = 2 and v ≡ λ ≡ 2 (mod 4) or the parameters of D belong to one of four families explicitly determined in our main theorem. 相似文献
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Friedhelm C Hummel Bernhard Voller Pablo Celnik Agnes Floel Pascal Giraux Christian Gerloff Leonardo G Cohen 《BMC neuroscience》2006,7(1):73-10
Background
Previous studies showed that anodal transcranial DC stimulation (tDCS) applied to the primary motor cortex of the affected hemisphere (M1affected hemisphere) after subcortical stroke transiently improves performance of complex tasks that mimic activities of daily living (ADL). It is not known if relatively simpler motor tasks are similarly affected. Here we tested the effects of tDCS on pinch force (PF) and simple reaction time (RT) tasks in patients with chronic stroke in a double-blind cross-over Sham-controlled experimental design. 相似文献87.
Single-beam coherent anti-Stokes Raman-scattering (CARS) microspectroscopy achieves a complete CARS scheme with a femtosecond laser. Here, we introduce heterodyne detection in a simple experimental extension: the optical fields driving the CARS process and the local oscillator used for heterodyning are derived from a single beam of ultrashort laser pulses by pulse shaping. The heterodyne signal is amplified by more than 3 orders of magnitude and is linearly dependent on the concentration of Raman scatterers. This dramatically increases the sensitivity of chemically selective detection at microscopic resolution while maintaining the simplicity of the single-beam setup. 相似文献
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Gemma M. Locke Dr. Stefan S. R. Bernhard Prof. Dr. Mathias O. Senge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(18):4590-4647
Nonconjugated hydrocarbons, like bicyclo[1.1.1]pentane, bicyclo[2.2.2]octane, triptycene, and cubane are a unique class of rigid linkers. Due to their similarity in size and shape they are useful mimics of classic benzene moieties in drugs, so-called bioisosteres. Moreover, they also fulfill an important role in material sciences as linear linkers, in order to arrange various functionalities in a defined spatial manner. In this Review article, recent developments and usages of these special, rectilinear systems are discussed. Furthermore, we focus on covalently linked, nonconjugated linear arrangements and discuss the physical and chemical properties and differences of individual linkers, as well as their application in material and medicinal sciences. 相似文献
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Prof. Dr. Bernhard Kräutler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15438-15445
The recently delineated structure- and reactivity-based concept of antivitamins B12 has begun to bear fruit by the generation, and study, of a range of such B12-dummies, either vitamin B12-derived, or transition metal analogues that also represent potential antivitamins B12 or specific B12-antimetabolites. As reviewed here, this has opened up new research avenues in organometallic B12-chemistry and bioinorganic coordination chemistry. Exploratory studies with antivitamins B12 have, furthermore, revealed some of their potential, as pharmacologically interesting compounds, for inducing B12-deficiency in a range of organisms, from hospital resistant bacteria to laboratory mice. The derived capacity of antivitamins B12 to induce functional B12-deficiency in mammalian cells and organs also suggest their valuable potential as growth inhibitors of cancerous human and animal cells. 相似文献