Search results for " Spin"
showing 10 items of 1036 documents
Molecular Spintronic Devices: from Molecular Spin Valves to Spin-OLEDs
2017
La investigación llevada a cabo durante el periodo de tesis doctoral y que se describe en este manuscrito pertenece al campo de la espintrónica molecular. Ha sido motivada por el deseo de incorporar nuevos materiales moleculares a dispositivos espintrónicos y ahondar en la comprensión de la inyección y el transporte de espín en este tipo de capas, a través del estudio de dispositivos como la válvula de espín molecular y el spin-OLED. En 1988 Albert Fert y Peter Grünberg descubrieron que la resistencia eléctrica de unas multicapas de Fe-Cr variaba considerablemente en función de la magnetización de las láminas. El efecto se conoce hoy en día como magnetoresistencia gigante o GMR, por sus sig…
Molecular nanostructures on ferromagnetic metals for spintronics
2017
El objetivo principal de esta tesis ha sido el estudio de la funcionalización de superficies ferromagnéticas mediante la formación de monocapas moleculares autoensambladas, (SAMs, self-assembled monolayers) con el fin de conseguir procesos sencillos y fiables para la preparación de interfaces híbridas aplicables en dispositivos de espintrónica molecular. La investigación se ha centrado en la funcionalización de materiales ferromagnéticos, concretamente el cobalto y la aleación de níquel:hierro conocida como Permalloy. Las propiedades magnéticas y de polarización de espín de estos metales ferromagnéticos se mantienen a temperatura ambiente, lo que los hace muy interesantes para su aplicación…
Spin crossover cobalt(II) molecular nanomagnets as dynamic molecular systems
2022
Los complejos mononucleares de iones metálicos paramagnéticos de la primera serie de transición con ligandos "no-inocentes" hechos a medida han surgido recientemente como prototípicos de sistemas moleculares dinámicos (DMSs, del inglés “dynamic molecular systems”). El enorme impacto de los DMSs en varios dominios de la nanociencia y nanotecnología molecular se debe a su capacidad para ejecutar funciones específicas y selectivas bajo el control de un estímulo externo que modula adecuadamente sus propiedades estructurales y electrónicas (ópticas, redox y magnéticas). En esta Tesis Doctoral, a lo largo de siete capítulos describimos la química y las propiedades físicas de una clase única de na…
Proprioceptive response strength in the primary sensorimotor cortex is invariant to the range of finger movement
2023
Available online 13 February 2023 Proprioception is the sense of body position and movement that relies on afference from the proprioceptors in muscles and joints. Proprioceptive responses in the primary sensorimotor (SM1) cortex can be elicited by stim- ulating the proprioceptors using evoked (passive) limb movements. In magnetoencephalography (MEG), propri- oceptive processing can be quantified by recording the movement evoked fields (MEFs) and movement-induced beta power modulations or by computing corticokinematic coherence (CKC) between the limb kinematics and cortical activity. We examined whether cortical proprioceptive processing quantified with MEF peak strength, relative beta supp…
NMR and μ+SR detection of unconventional spin dynamics in Er(trensal) and Dy(trensal) molecular magnets
2019
Sexual dimorphism in the vertebral wedging of the human lumbar vertebrae and its importance as a comparative framework for understanding the wedging …
2020
Lumbar lordosis is a key element of the upright posture, being interpreted as a consequence of bipedal locomotion. There is consensus that the generic modern human pattern of metameric vertebral body wedging is sexually dimorphic in modern humans. However, recently published studies have compared this pattern with other hominins, such as Neanderthals. These tried to establish whether the (male) Neanderthal lumbar vertebrae express a pattern that falls within or outside the range of modern human males. In the present study, data collected by 3D landmarks of the lumbar vertebrae of modern humans from different geographic regions and Neanderthals (Ntotal = 505 individual vertebrae) are used to…
The assessment of skeletal status in young patients with Turner syndrome by 2 densitometric techniques: Phalangeal quantitative ultrasound and dual e…
2018
Background. Studies using dual energy X-ray absorptiometry (DXA) demonstrate a reduction in bone mineral density (BMD) in children and adolescents with Turner syndrome (TS). However, these studies do not take into account changes in bone size, which influence BMD in the case of short-statured patients. Phalangeal quantitative ultrasound (phQUS) measurements have shown an ability to reveal changes due to skeletal growth, aging, and bone and mineral disorders. There is limited data on bone mineral status in girls with TS assessed by 2 different techniques, i.e., DXA and phQUS. Objectives. The aim of this study was to investigate the potential negative impact of TS on bone status and to assess…
Effectiveness of a 12-month home-based exercise program on trunk muscle strength and spine function after lumbar spine fusion surgery:a randomized co…
2022
Purpose: The effectiveness of a 12-month home-exercise program on trunk muscle strength after lumbar spine fusion surgery was evaluated. Materials and methods: Three months postoperatively, 98 patients were randomized either to the exercise group (EG), with a progressive 12-month home-based exercise program, or to usual care group (UCG), with one guidance session for light home-exercises. Maximal trunk muscle strength was measured by a strain-gauge dynamometer and trunk extensor endurance was measured by Biering-Sørensen’s test at baseline and after the intervention. Results: The mean change in extension strength during the intervention was 75 N in EG and 58 N in UCG. Flexion strength impro…
The early changes in trunk muscle strength and disability following lumbar spine fusion
2012
To analyze trunk muscle function pre- and postoperatively in patients undergoing lumbar spine fusion. Associations between changes in trunk muscle strength and disability were also studied.A total of 114 patients undergoing lumbar spine fusion participated in the study. The flexion and extension strength of the trunk was measured preoperatively and 3 months after surgery using a strain-gauge dynamometer. Disability and pain during the past week was evaluated with the Oswestry disability index (ODI) and visual analog scale (VAS), respectively.Preoperative trunk extension and flexion strength levels were 319 N and 436 N in males, respectively, and 160 N and 214 N in females, respectively. In …
Effects of pregnancy on lumbar motion patterns and muscle responses.
2018
The kinematics of the lumbar region and the activation patterns of the erector spinae muscle have been associated with the genesis of low back pain, which is one of the most common complications associated with pregnancy. Despite the high prevalence of pregnancy-related low back pain, the biomechanical adaptations of the lumbar region during pregnancy remain unknown.This study analyzes lumbar spine motion and the activation pattern of the lumbar erector spinae muscle in healthy pregnant women.A case-control study.The study involved 34 nulliparous women (control group) and 34 pregnant women in the third trimester (week 36 ± 1).We recorded the parameters of angular displacement of the lumbar …