Impact of device resistances in the performance of graphene-based terahertz photodetectors.

In recent years, graphene field-effect-transistors (GFETs) have demonstrated an outstanding potential for terahertz (THz) photodetection due to their fast response and high-sensitivity. Such features are essential to enable emerging THz applications, including 6G wireless communications, quantum information, bioimaging and security. However, the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device, so-called access or parasitic resistances.

Enhanced terahertz detection of multigate graphene nanostructures.

Terahertz (THz) waves have revealed a great potential for use in various fields and for a wide range of challenging applications. High-performance detectors are, however, vital for exploitation of THz technology. Graphene plasmonic THz detectors have proven to be promising optoelectronic devices, but improving their performance is still necessary.

Responsivity enhancement of a strained silicon field-effect transistor detector at 0.3 THz using the terajet effect.

We report on the enhancement of responsivity by more than one order of magnitude of a silicon-based sub-terahertz detector when a mesoscopic dielectric particle was used to localize incident radiation to a sub-wavelength volume and focus it directly onto the detector. A strained-silicon modulation field-effect transistor was used as a direct detector on an incident terahertz beam at 0.3 THz.

Numerical Study of the Coupling of Sub-Terahertz Radiation to n-Channel Strained-Silicon MODFETs.

This paper reports on a study of the response of a T-gate strained-Si MODFETs (modulation-doped field-effect transistor) under continuous-wave sub-THz excitation. The sub-THz response was measured using a two-tones solid-state source at 0.15 and 0.

Sub-THz Imaging Using Non-Resonant HEMT Detectors.

Plasma waves in gated 2-D systems can be used to efficiently detect THz electromagnetic radiation. Solid-state plasma wave-based sensors can be used as detectors in THz imaging systems. An experimental study of the sub-THz response of II-gate strained-Si Schottky-gated MODFETs (Modulation-doped Field-Effect Transistor) was performed.

[Not Available].

La deficiencia de vitamina A es infrecuente en los países desarrollados. La cirugía bariátrica constituye un factor de riesgo de deficiencia de esta vitamina. Se han descrito varios casos en pacientes sometidos a técnicas con un importante componente malabsortivo, como la derivación biliopancreática.

[Drug-induced movement disorders].

Introduction: Pharmaceutical preparations with the capacity to block dopamine receptors at the brain level quite often cause secondary movement disorders, but are not the only cause. These movement disorders can be due to a poor or difficult capacity to carry out movements similar to the type observed in idiopathic Parkinson's disease (parkinsonism secondary to drugs) or also because of excess movement with acute or chronic dystonic or choreic clinical pictures. Why the same drugs cause apparently opposing effects is not altogether clear, although it is supposed that individual factors related to the pharmacokinetics, pharmacodynamics and sensitivity of different types of sub-receptors play a crucial role.

[Reye's syndrome. Description of a case focused on the patient's epileptic seizures].

Introduction: Reye's syndrome is an acute disease characterised by encephalopathy and fatty degeneration of the liver that occurs almost exclusively in children. It can cause the death of the patient in up to a third of all cases, generally due to severe cerebral oedema. The aetiopathogenesis of this condition is uncertain and is usually preceded by a viral infection, generally from the influenza or varicella virus.

Efficacy of long-term continuous subcutaneous apomorphine infusion in advanced Parkinson's disease with motor fluctuations: a multicenter study.

Continuous subcutaneous apomorphine infusion (CSAI) is, at present, an alternative option for advanced Parkinson's disease (PD) with motor fluctuations. We studied the evolution of patients with PD and severe motor fluctuations long-term treated with CSAI. We reviewed data from 82 patients with PD (mean age, 67 +/- 11.

[Neurological sequelae following electrocution. A case report and review of the literature].

Introduction: Electrocution is the cause of a large number of accidents and, of these, a considerable percentage result in death. Several factors affect the severity and distribution of the injuries. It is known that for low voltages the characteristics of alternating current make it three times more dangerous than continuous current.

[Respiratory stridency by larynx paralysis. Anusual beginning of miastenia].

A case of severe miastenia beginning with dyspnea, secondary to a bilateral larynx paralysis in aduction is presented. During the evolution of the severe miastenia the affectation of the larynx musculature does not result infrequent, but however, after having realized a bibliographic revision, the infrequency resulting in this disease of the beginning through a bilateral larynx paralysis in aduction was verified. A wide exposition of the clinic case, methods of exploration to obtain the diagnosis of severe miastenia, and the different treatment options actually in use to control these disease, are realized.

[Transcranial Doppler during transient global amnesia].

Introduction: Transient global amnesia is a syndrome mainly characterised by an anterograde memory deficit, which disappears in less than 24 hours without leaving any kind of sequelae. Its aetiopathogenesis is still unclear. The ischemic theory became important after hypoperfusion was observed in the mesial region of the temporal lobe using different imaging techniques, although recently the use of diffusion-weighted magnetic resonance imaging by other authors has not revealed these alterations in the cerebral blood flow.

[Encephalomyelitis due to Epstein-Barr virus].

We present a 28-year-old woman with encephalomyelitis and concomitant central nervous system infection by Epstein-Barr virus. Progression took place in 2 phases, with myelitis at the beginning and encephalitis developing later. Despite great functional impairment, recovery was good and the patient was left suffering only from urinary retention that was presumably caused by spinal lesions.