Wattmeter based on tunnel-effect magnetoresistance sensor.

This work shows how the tunnel-effect based magnetoresistance (TMR) technology can be used as a competitive sensing method in electrical current and power processors. The sensor is arranged in a Wheatstone bridge topology, and each magnetoresistance was composed of a series connection of 360 magnetic tunnel junction elements with the following structure (thickness in nm): 100 SiO2/5 Ta/15 Ru/5 Ta/15 Ru/5 Ta/5 Ru/20 IrMn/2 CoFe30/0.85 Ru/2.6 CoFe40B20/1.2 MgO/2 CoFe40B20/0.21 Ta/4 NiFe/0.20 Ru/6 IrMn/2 Ru/5 Ta/10 Ru. First, the electrical and thermal characteristics of the sensor were evaluated by analyzing its response to DC current sweeps at various temperatures, controlled using a climatic chamber. Nominal values of current sensitivity S (0.324 mV/A), bridge output offset voltage Vo,s,o (-37.1 mV), bridge input resistance Rinp,bridge (0.958 kΩ), and their thermal behavior were obtained (0.0036 mV/A°C, 0.079 mV/°C, and -0.31 Ω/°C). Second, an instrumentation system is introduced to characterize the sensor, measuring its sensitivity to AC line currents from the mains up to 10 Arms. Finally, an electronic wattmeter was developed showing the relevant quantities of its design. The circuit is able to interface a TMR Wheatstone bridge to an analog processor. Power and current measurements were obtained from a 150 Vrms AC mains 1.5 kW load with resistive and capacitive components, achieving less than 1% deviation over the expected values. The circuit shown can be used to interface these signals to more complex smart digital engines with active or reactive energy processing capabilities, while providing inherent high voltage isolation, thanks to its TMR measurement technology.

Coexistent central retinal vein and artery occlusion in a patient with psoriasis receiving ustekinumab. / Oclusión coexistente de vena y arteria central de la retina en un paciente con psoriasis en tratamiento con ustekinumab.

A 44 year-old Caucasian male with a history of plaque psoriasis currently being treated with ustekinumab presented with sudden loss of vision in his left eye. Fundus examination showed central retinal vein occlusion coexisting with central retinal artery occlusion. Posterior examination revealed mild polycythemia, being the underlying cause unknown.

Development and optimisation of an animal model for the study of ganglion cells in degenerative diseases of the retina and optic nerve. / Desarrollo y optimización de un modelo animal para el estudio de las células ganglionares en enfermedad degenerativa de la retina y nervio óptico.

INTRODUCTION: Multiple sclerosis is an autoimmune, chronic and inflammatory disease of the central nervous system with axonal demyelination, gliosis and neurodegeneration. It is considered a frequent cause of neurological disability in young adults. In this work, an Experimental Autoimmune Encephalomyelitis (EAE) model was optimised by injecting a myelin oligodendrocyte glycoprotein (MOG35-55). The ophthalmological effects were studied, as well as its use as an experimental model in other studies of retinal ganglion cell degeneration (RGC) and optic nerve (ON). MATERIAL AND METHODS: The study included 16 mice of 10 weeks that were placed into 2 study groups: a control group of 10 animals and another group of 6 animals with EAE that were injected with MOG35-55. The animals of the EAE model were monitored using motor disability scales. The retinas and optic nerves were processed for morphological examination by optical microscopy and ultrastructure studies. RESULTS: The animal models presented with motor symptoms of spinal cord injury, with the first symptoms appearing between the 7th and 19th day post-injection, with a maximum disability mean of 3.5 points. In the retina, the mean RGC in the EAE group was 0.0891µm, compared with 0.1678µm of the control group (p=.0003). The ON was strongly affected with reactive gliosis, increased axonal damage and decreased density axonal (control group 0.38038 axons/µm2 versus EAE group 0.16 axons/µm2, p=.00032). CONCLUSIONS: In this work an animal model of EAE has been characterised and detailed for the study of demyelinating alterations in the retina and the ON. Its characteristics make it an excellent tool for the study of neurodegenerative ophthalmic diseases.

[Non-infectious corneal macroperforations treated with a combination of Tachosil(®) and Tutopach(®). A report of 2 cases]. / Macroperforaciones corneales no infecciosas tratadas con la asociación de TachoSil(®) y Tutopach(®). A propósito de 2 casos.

CLINICAL CASE: We report 2 cases of patients affected by non-infectious corneal macroperforations treated with TachoSil(®) and Tutopach(®), which closed the defect. DISCUSSION: This procedure is an excellent choice for the emergency treatment of corneal perforation, especially in those centres that have no other therapeutic options, preserving the eye and visual acuity.