6,771 research outputs found
Bilateral triad of persistent median artery, a bifid median nerve and high origin of its palmar cutaneous branch. A case report and clinical implications
We report the association of a persistent median artery, a bifid median nerve with a rare very high origin palmar cutaneous branch, presenting bilaterally in the upper limb of a 75-year-old female cadaver. The persistent median nerve with a bifid median nerve has been reported in patients presenting with carpal tunnel syndrome. Reports of this neurovascular anomaly occurring in association with a high origin palmar cutaneous branch however, are few. This subset of patients is at risk of inadvertent nerve transection during forearm and wrist surgery. Pre-operative magnetic resonance imaging (MRI) and high resolution sonography (HRS) can be used to screen this triad. MRI can reveal if the patient’s disability is associated with a persistent median nerve, a bifid median nerve. HRS can help identify a palmar cutaneous branch of the median nerve that arises in an unexpected high forearm location. Such knowledge will help surgeons in selecting the most appropriate surgical procedure, and help avoid inadvertent injury to cutaneous nerves arising in unexpected locations. In patients presenting with a bilateral carpal tunnel syndrome, hand surgeons should consider very high on the list of differential diagnosis a persistent median artery with a concomitant bifid median nerve, with a high suspicion of a possible bilateral occurrence of a bilaterally high arising palmar cutaneous branch of the median nerve. © 2016, Universidad de la Frontera. All rights reserved
Anatomy and giant enhancement of the perpendicular magnetic anisotropy of cobalt-graphene heterostructures
We report strongly enhanced perpendicular magnetic anisotropy (PMA) of Co
films by graphene coating from both first-principles and experiments. Our
calculations show that graphene can dramatically boost the surface anisotropy
of Co films up to twice the value of its pristine counterpart and can extend
the out-of-plane effective anisotropy up to unprecedented thickness of 25~\AA.
These findings are supported by our experiments on graphene coating on Co films
grown on Ir substrate. Furthermore, we report layer-resolved and
orbital-hybridization-resolved anisotropy analysis which help understanding the
physical mechanisms of PMA and more practically can help design structures with
giant PMA. As an example, we propose super-exchange stabilized Co-graphene
heterostructures with a robust out-of-plane constant effective PMA and linearly
increasing interfacial anisotropy as a function of film thickness. These
findings point towards possibilities to engineer graphene/ferromagnetic metal
heterostructures with giant magnetic anisotropy more than 20 times larger
compared to conventional multilayers, which constitutes a hallmark for future
graphene and traditional spintronic technologies.Comment: 17 pages, 4 figure
Sensitive superoxide detection in vascular cells by the new chemiluminescence dye L-012
The detection superoxide production in vascular cells is usually limited by a low sensitivity of available assays, We tested the applicability of the luminol derivate L-012 {[}8-amino-5-chloro-7-phenylpyridol{[}3,4-d]pyridazine-l,4(2H,3H)dione] to measure superoxide production in cultured endothelial cells (human umbilical vein endothelial cells) and rat aortic segments. Following stimulation with the protein kinase stimulator phorbol 12-myristate 13-acetate (PMA, 1 mu M) there was an 2,8-fold increase of L-012 chemiluminescence, whereas incubation with angiotensin II (100 nM) did not result in a measurable increase. Addition of vanadate (100 mu M) considerably increased the chemiluminescence (up to 17-fold) after PMA and made possible the detection of an enhanced superoxide production after stimulation with angiotensin II (by 1.7-fold). This was due to a similar to 9-fold increase in signal intensity of L-012 in the presence of vanadate, Prolonged incubation with vanadate also led to a tyrosine phosphorylation-dependent increase in superoxide formation which was predominantly produced by an NAD(P)H oxidase. Short-Term vanadate-enhanced L-012 chemiluminescence represents a highly sensitive assay making it possible to detect small changes of superoxide formation in intact vascular cells. Copyright(C) 1999 S. Karger AG. Basel
Light-induced magnetization reversal of high-anisotropy TbCo alloy films
Magnetization reversal using circularly polarized light provides a new way to
control magnetization without any external magnetic field and has the potential
to revolutionize magnetic data storage. However, in order to reach ultra-high
density data storage, high anisotropy media providing thermal stability are
needed. Here, we evidence all-optical magnetization switching for different
TbxCo1-x ferrimagnetic alloy composition and demonstrate all-optical switching
for films with anisotropy fields reaching 6 T corresponding to anisotropy
constants of 3x106 ergs/cm3. Optical magnetization switching is observed only
for alloys which compensation temperature can be reached through sample
heating
A Multiplier Related to Symmetric Stable Processes
In two recent papers [5] and [6], we generalized some classical results of
Harmonic Analysis using probabilistic approach by means of a d- dimensional
rotationally symmetric stable process. These results allow one to discuss some
boundedness conditions with weaker hypotheses. In this paper, we study a
multiplier theorem using these more general results. We consider a product
process consisting of a d-dimensional symmetric stable process and a
1-dimensional Brownian motion, and use properties of jump processes to obtain
bounds on jump terms and the L^p(R^d)-norm of a new operator.Comment: 13 page
Differential Interleukin-2 Transcription Kinetics Render Mouse but Not Human T Cells Vulnerable to Splicing Inhibition Early after Activation
T cells are nodal players in the adaptive immune response against pathogens and malignant cells. Alternative splicing plays a crucial role in T cell activation, which is analyzed mainly at later time points upon stimulation. Here we have discovered a 2-h time window early after stimulation where optimal splicing efficiency or, more generally, gene expression efficiency is crucial for successful T cell activation. Reducing the splicing efficiency at 4 to 6 h poststimulation significantly impaired murine T cell activation, which was dependent on the expression dynamics of the Egr1-Nab2-interleukin-2 (IL-2) pathway. This time window overlaps the time of peak IL-2 de novo transcription, which, we suggest, represents a permissive time window in which decreased splicing (or transcription) efficiency reduces mature IL-2 production, thereby hampering murine T cell activation. Notably, the distinct expression kinetics of the Egr1-Nab2-IL-2 pathway between mouse and human render human T cells refractory to this vulnerability. We propose that the rational temporal modulation of splicing or transcription during peak de novo expression of key effectors can be used to fine-tune stimulation-dependent biological outcomes. Our data also show that critical consideration is required when extrapolating mouse data to the human system in basic and translational research
A polymorphism associated with depressive disorders differentially regulates brain derived neurotrophic factor promoter IV activity
PMCID: PMC3712170Peer reviewedPublisher PD
Towards an understanding of the impact of resources on the design process
Considerable effort has been devoted within the design research community to understanding the structure of design processes and their development for different design problems. Whilst much work has examined the impact of design goals upon the structure of a design process, less attention has been paid to the role that design resources can play. This paper describes an experiment directed towards gaining an understanding of the impact that both active resources (which perform design tasks) and passive resources (which are used by active resources) can have upon design process structure. Main outcomes from the experiment were the conclusive identification that resources can significantly impact design process structure and a number of examples of how these impacts manifest themselves. The main conclusion of the paper is that given the sizeable impact resources can have upon process structure, there is a considerable need to obtain a greater understanding of these impacts to facilitate the development of techniques that can support design process definition based upon an understanding of the design resources being used to solve a design problem
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