Publications by authors named "U GUEVARA"

In this work, we investigate the influence of curvature on the dynamic susceptibility in FeGe nanowires, both curved and straight, hosting a skyrmionic tube texture under the action of an external bias field, using micromagnetic simulations. Our results demonstrate that both the resonance frequencies and the number of resonant peaks are highly dependent on the curvature of the system. To further understand the nature of the spin wave modes, we analyze the spatial distributions of the resonant mode amplitudes and phases, describing the differences among resonance modes observed.

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Boronate esters are a class of compounds containing a boron atom bonded to two oxygen atoms in an ester group, often being used as precursors in the synthesis of other materials. The characterization of the structure and properties of esters is usually carried out by UV-visible, infrared, and nuclear magnetic resonance (NMR) spectroscopic techniques. With the aim to better understand our experimental data, in this article, the density functional theory (DFT) is used to analyze the UV-visible and infrared spectra, as well as the isotropic shielding and chemical shifts of the hydrogen atoms H, carbon C and boron B in the compound 4-(4,4,5,5-tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde.

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The use of computational methods that allow us to perform characterization on new compounds is not a novelty; nevertheless, the degree of complexity of the structures makes their study more challenging since new techniques and methods are required to adjust to the new structural model. The case of nuclear magnetic resonance characterization of boronate esters is fascinating because of its widespread use in materials science. In this paper, we use density functional theory to characterize the structure of the compound 1-[5-(4,5-Dimethyl-1,3,2-dioxaborolan-2-yl)thiophen-2-yl]ethanonea by means of nuclear magnetic resonance.

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Motor cortex stimulation (MCS) is useful to treat patients with neuropathic pain syndromes, unresponsive to medical treatment. Complex regional pain syndrome (CRPS) is a segmentary disease treated successfully by spinal cord stimulation (SCS). However, CRPS often affects large body segments difficult to cover by SCS.

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We undertook this case series to determine if preexisting neurological disease is exacerbated by either spinal or epidural anesthesia. In the website of the Arachnoiditis Foundation, we posted an offer to advise anesthesiologists in cases of neurological problems after either of these techniques was used. Contacts were made first by way of the Internet, confirmed by telephone, and maintained by fax, e-mail, or by special mail.

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