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1.
Ann Anat ; 250: 152130, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37467811

RESUMO

INTRODUCTION: The aim of this review was to summarize the available evidence for biomechanical stability following surgical DOB reconstruction, and to determine whether distal radioulnar joint (DRUJ) stability with a reconstructed DOB was similar to the native intact condition or that after the Adams procedure. MATERIAL AND METHODS: A systematic literature search according to the PRISMA guidelines was performed using the databases PubMed and Embase. The following search algorithm was used: ("DOB" OR "Distal Oblique Bundle") AND "Reconstruction". Biomechanical or human cadaveric studies that measured stability of the DRUJ after reconstruction of the DOB were included. RESULTS: Four articles were included in the final analysis. DOB incidence was reported to be between 50% and 70%. Two studies observed no differences between the intact situation and the reconstructed DOB, respectively the Adams procedure. A further author group found no signs of major instability after the Adams reconstruction or after DOB reconstruction, except for decreased stability during supination in the DOB sample. In another study, similar results could be shown for the Adams and DOB reconstruction groups; however, the DOB sample showed decreased dorsal translation of the radius during forearm supination. CONCLUSION: In conclusion, DOB reconstruction was proven to stabilize the DRUJ adequately. Moreover, the reconstructed DOB showed the same stability as the native DOB, except for one study, in which stability following reconstruction was reduced during supination. No significant difference between the DOB and the Adams reconstruction could be observed.


Assuntos
Instabilidade Articular , Humanos , Instabilidade Articular/cirurgia , Rádio (Anatomia) , Articulação do Punho/cirurgia , Extremidade Superior , Fenômenos Biomecânicos , Cadáver , Ulna
2.
Physiol Meas ; 42(10)2021 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-34496357

RESUMO

Objective.Recent research suggests that percutaneous auricular vagus nerve stimulation (pVNS) beneficially modulates the autonomic nervous system (ANS). Bursted pVNS seems to be efficient for nerve excitation. Bursted pVNS effects on cardiac autonomic modulation are not disclosed yet.Approach.For the first time, the present study evaluates the effect of pVNS on cardiac autonomic modulation in healthy subjects (n = 9) using two distinct bursted stimulation patterns (biphasic and triphasic stimulation) and heart rate variability analysis (HRV). Stimulation was delivered via four needle electrodes in vagally innervated regions of the right auricle. Each of the two bursted stimulation patterns was applied twice in randomized order over four consecutive stimulation sessions per subject.Main results.Bursted pVNS did not change heart rate, blood pressure, and inflammatory parameters in study subjects. pVNS significantly increased the standard deviation of heart inter-beat intervals, from 46.39 ± 10.4 ms to 63.46 ± 22.47 ms (p < 0.05), and the total power of HRV, from 1475.7 ± 616.13 ms2to 3190.5 ± 2037.0 ms2(p < 0.05). The high frequency (HF) power, the low frequency (LF) power, and theLF/HFratio did not change during bursted pVNS. Both stimulation patterns did not show any significant differences in cardiac autonomic modulation. Stimulation intensity to reach a tingling sensation was significantly lower in triphasic compared to biphasic stimulation (p< 0.05). Bursted stimulation was well tolerated.Significance.Bursted pVNS seems to affect cardiac autonomic modulation in healthy subjects, with no difference between biphasic and triphasic stimulation, the latter requiring lower stimulation intensities. These findings foster implementation of more efficient pVNS stimulation.


Assuntos
Estimulação do Nervo Vago , Sistema Nervoso Autônomo , Voluntários Saudáveis , Frequência Cardíaca , Humanos , Nervo Vago
3.
Nano Lett ; 18(5): 2828-2834, 2018 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-29620910

RESUMO

We present a detailed study on the static magnetic properties of individual permalloy nanotubes (NTs) with hexagonal cross-sections. Anisotropic magnetoresistance (AMR) measurements and scanning transmission X-ray microscopy (STXM) are used to investigate their magnetic ground states and its stability. We find that the magnetization in zero applied magnetic field is in a very stable vortex state. Its origin is attributed to a strong growth-induced anisotropy with easy axis perpendicular to the long axis of the tubes. AMR measurements of individual NTs in combination with micromagnetic simulations allow the determination of the magnitude of the growth-induced anisotropy for different types of NT coatings. We show that the strength of the anisotropy can be controlled by introducing a buffer layer underneath the magnetic layer. The magnetic ground states depend on the external magnetic field history and are directly imaged using STXM. Stable vortex domains can be introduced by external magnetic fields and can be erased by radio-frequency magnetic fields applied at the center of the tubes via a strip line antenna.

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