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1.
Acta Neurochir Suppl ; 135: 109-114, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38153457

RESUMEN

A Meckel's cave tumor poses a great challenge because of the peculiar neurovascular structure of the area and the deep location. Multiple surgical approaches have been designed for this area. In this report, we describe a case treated with a combined one step single piece fronto-temporo-orbito-zygomatic craniotomy (FTOZ) endoscopic-assisted approach for the treatment of an epidermoid tumor of Meckel's cave. A 51-year-old woman presented with a clinical history of left trigeminal neuralgia and paresthesia. CT imaging revealed a left basal temporal tumor. MR showed a tumor located in Meckel's cave near the cavernous sinus, with a good enhancement after gadolinium administration. The tumor was resected through a lateral basal subtemporal extradural approach followed by an intradural approach using intraoperative neuronavigation, endoscopic assistance, neurophysiological monitoring, and an intraoperative ultrasound probe. The lesion was completely removed. No new onset neurological damage has occurred. The symptoms improved following surgery. The aesthetic appearance of the patient was respected. The combined approach with a single piece fronto-temporo-orbito-zygomatic craniotomy has enabled us to work on a wider operating field to completely remove the lesion avoiding blind spots.


Asunto(s)
Neoplasias , Femenino , Humanos , Persona de Mediana Edad , Craneotomía , Neuronavegación
2.
Acta Neurochir Suppl ; 135: 279-282, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38153482

RESUMEN

Odontoid fractures, frequently observed in patients over the age of 70, often involve the base of the axis (Anderson-D'Alonzo type 2). For surgical treatment, posterior C1-C2 fixation is the traditional method, whose fusion rates range between 93 and 100%. However, morbidity and mortality rates are high. In addition, cervical motion, especially axial rotation, is postoperatively reduced. Nakanishi and Bohler introduced the anterior screw fixation approach for the surgical treatment of odontoid fracture type II. This procedure preserves the atlantoaxial complex motion, provides immediate stability and high fracture healing rates, and, most importantly, has a low incidence of complications with good fusion rates. The surgical strategy must take into account the patient's anatomy, the morphological characteristics of the fracture, the quality of the bone, and any concomitant injuries. In this chapter, we describe a C2 type II fracture treated via a neuronavigated anterior retropharyngeal approach.


Asunto(s)
Apófisis Odontoides , Humanos , Apófisis Odontoides/diagnóstico por imagen , Apófisis Odontoides/cirugía , Tornillos Óseos , Cuello , Rotación
3.
Acta Neurochir Suppl ; 135: 361-366, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38153494

RESUMEN

The aim of this study was to determine the relationship between cervical spine sagittal alignment and clinical outcomes after using a standalone intersomatic titanium cage CeSPACE for anterior cervical discectomy and arthrodesis. We present our clinical experience in a group of 180 patients with a mean follow-up for at least 2 years. Patients were evaluated by clinical and radiological assessment preoperatively, immediately after surgery and at regular follow-up. There were 97 male and 83 female patients (average age: 56.6 years) who were preoperatively affected by cervical radiculomyelopathy that was due to spondylosis or cervical disk herniation and who underwent surgical treatment. All patients underwent an anterior discectomy and interbody fusion through the positioning of one or more levels of the CeSPACE device. Compared with the preoperative scores, improvement was seen in postoperative visual analog scale (VAS) scores and Neck Disability Index (NDI) values. The standalone intersomatic titanium cage CeSPACE for anterior cervical discectomy and arthrodesis improved radiculomyelopathy and increased the probability of cervical kyphotic alignment. However, cervical sagittal alignment after surgery was not significantly associated with clinical outcomes in terms of postoperative improvement in VAS scores and NDI values. Similarly, the change in cervical sagittal alignment was not related to visual analog scale scores or Neck Disability Index values.


Asunto(s)
Espondilosis , Titanio , Humanos , Femenino , Masculino , Persona de Mediana Edad , Discectomía , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Cuello , Espondilosis/diagnóstico por imagen , Espondilosis/cirugía
4.
Eur Rev Med Pharmacol Sci ; 24(19): 10293-10300, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33090441

RESUMEN

Acute SARS-CoV-2 respiratory disease is an infectious respiratory disease caused by the virus SARS-CoV-2 belonging to the coronaviridae family. A pandemic is still present as of May 2020. In addition to causing pneumonia, SARS-CoV-2 may induce a direct damage to the heart, causing myocarditis, with significant impairment of cardiac contractility, and/or pericarditis. Elderly patients and those with cardiovascular risk factors, such as hypertension and diabetes mellitus, are at increased risk of heart complications from COVID-19. In this review, we focused on the correlation between COVID-19 infection and the high sensitivity troponin T and I, and their significance in the development of myocarditis. Data emerging from the studies so far conducted indicate that a high value of high-sensitivity troponin represents a negative prognostic indicator when associated with heart damage on an infectious-inflammatory basis (i.e. myopericarditis). We should identify a safe and clear diagnostic algorithm, possibly combining patient clinical history, troponin levels and cardiac ultrasound findings that could help us in the prediction of myopericarditis.


Asunto(s)
COVID-19/diagnóstico , Miocarditis/diagnóstico , Troponina I/sangre , Troponina T/sangre , COVID-19/sangre , COVID-19/complicaciones , Humanos , Miocarditis/sangre , Miocarditis/complicaciones , Pandemias , Pronóstico , SARS-CoV-2
5.
J Phys Chem Lett ; 9(17): 5002-5008, 2018 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-30107131

RESUMEN

In this work, we show how to control the morphology of femtosecond laser melted gold nanosphere aggregates. A careful choice of both laser fluence and wavelength makes it possible to selectively excite different aggregate substructures to produce larger spherical nanoparticles, nanorods, and nanoprisms or necklace-like 1D nanostructures in which the nanoparticles are interlinked by bridges. Finite integral technique calculations have been performed on the near-field concentration of light in the nanostructures which confirm the wavelength dependence of the light concentration and suggest that the resulting localized high intensities lead to nonthermal melting. We show that by tuning the wavelength of the melting light it is possible to choose the spatial extension of the ensembles of NPs heated thus allowing us to exhibit control over the morphology of the nanostructures formed by the melting process. By a proper combination of this method with self-assembly of chemically synthesized nanoparticles, one can envisage the development of an innovative high-throughput high-resolution nanofabrication technique.

6.
Nanoscale ; 9(14): 4730-4738, 2017 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-28327734

RESUMEN

We studied the oscillator strength fgap of the band gap transition in heteronanocrystals (hNCs) with a spherical CdSe core embedded in an elongated CdS shell. A comparison with fgap of core-only CdSe NCs confirmed a reduction of the electron-hole overlap in hNCs with a band gap larger than 2.05 eV or smaller than 1.98 eV. However, the decrease in fgap is limited to about 50% when compared to CdSe NCs, suggesting that residual confinement still localizes the electron near the core. We correlated fgap with the radiative lifetime obtained from multiexponential photoluminescence (PL) decay traces. The different components were attributed to radiative decay, or deep and shallow carrier trapping, respectively, using the PL quantum efficiency (QE) as a guideline. Our data highlight the challenges associated when extracting the radiative decay, and demonstrate the added value of absorption spectroscopy to obtain the band-edge oscillator strength and the associated radiative recombination rate in colloidal hNCs.

7.
Transplant Proc ; 47(7): 2113-5, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26361656

RESUMEN

INTRODUCTION: Since 2013, the regional network of transplantation centers "LAZIO TRANSPLANT" have adopted a new, mixed system for the allocation of liver grafts. METHODS: The organs from donors aged <65 are assigned to patients with higher Model for End-stage Liver Disease (MELD) scores on a common regional waiting list, whereas those from donors aged >65 are allocated to patients with higher MELD scores on a specific local waiting list (LWL) at each center, on a rotational basis. RESULTS: The new mixed allocation model grants a more rational allocation of the "standard" organs to the patients with the actual worst MELD score in the entire region, avoiding the possibility that a patient in relatively better clinical condition might be transplanted before a more severely ill patient on another center's waiting list. Nonstandard organs, presenting slightly increased transplant risks, are still allocated on a rotational basis among the different transplant centers, ensuring them the possibility to select, on the basis of a global clinical risk evaluation, those patients in their LWL whose MELD score would not grant any possibility to compete for the "standard" organ allocation. CONCLUSIONS: The application of the new model had no negative impact on the overall number of transplants performed or on the global list-satisfaction percentages, but has slightly improved the cumulative mortality of the patients in the waiting list, granting to the clinically worst patients a prompt graft allocation, independent of the local center belonging.


Asunto(s)
Trasplante de Hígado/estadística & datos numéricos , Asignación de Recursos/métodos , Obtención de Tejidos y Órganos/métodos , Anciano , Femenino , Humanos , Italia , Trasplante de Hígado/normas , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Obtención de Tejidos y Órganos/normas , Listas de Espera
8.
Nano Lett ; 15(9): 6128-34, 2015 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-26262899

RESUMEN

Outstanding results have been achieved in the localization of optical electric fields via ultrasmall plasmonic cavities, paving the way to the subdiffractive confinement of local electromagnetic fields. However, due to the intrinsic constraints related to conventional architectures, no comparable squeezing factors have been managed yet for the magnetic counterpart of radiation, practically hindering the detection and manipulation of magneto-optical effects at the nanoscale. Here, we observe a strong magnetic field nanofocusing in the infrared, promoted by the induction of a coil-type Fano resonance. By triggering the coil current via a quadrupole-like plasmonic mode, we straightforwardly boost the enhancement of the infrared magnetic field and perform its efficient squeezing in localized nanovolumes.

9.
Sci Rep ; 5: 11237, 2015 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-26057661

RESUMEN

The sub-wavelength concentration and propagation of electromagnetic energy are two complementary aspects of plasmonics that are not necessarily co-present in a single nanosystem. Here we exploit the strong nanofocusing properties of stacked optical antennas in order to highly concentrate the electromagnetic energy into a 5 nm metal-insulator-metal (MIM) cavity and convert free radiation into guided modes. The proposed nano-architecture combines the concentration properties of optical nanoantennas with the propagation capability of MIM systems, paving the way to highly miniaturized on-chip plasmonic waveguiding.

10.
Nano Lett ; 14(6): 3166-71, 2014 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-24849081

RESUMEN

The possibility to develop nanosystems with appreciable magnetic response at optical frequencies has been a matter of intense study in the past few years. This aim was strongly hindered by the saturation of the magnetic response of "natural" materials beyond the THz regime. Recently, in order to overcome such limitation, it has been considered to enhance the magnetic fields through the induction of displacement currents triggered by plasmonic resonances. Here we investigate a nanoassembly supporting the hybridization of an electric and magnetic plasmonic mode in Fano resonance conditions. Taking advantage of the enhancement properties owned by such interferential resonance, we have been able to generate an intense and localized magnetic hot-spot in the near-infrared spectral region.

11.
Nat Nanotechnol ; 8(11): 845-52, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24141538

RESUMEN

Surface plasmon polaritons are a central concept in nanoplasmonics and have been exploited to develop ultrasensitive chemical detection platforms, as well as imaging and spectroscopic techniques at the nanoscale. Surface plasmons can decay to form highly energetic (or hot) electrons in a process that is usually thought to be parasitic for applications, because it limits the lifetime and propagation length of surface plasmons and therefore has an adverse influence on the functionality of nanoplasmonic devices. Recently, however, it has been shown that hot electrons produced by surface plasmon decay can be harnessed to produce useful work in photodetection, catalysis and solar energy conversion. Nevertheless, the surface-plasmon-to-hot-electron conversion efficiency has been below 1% in all cases. Here we show that adiabatic focusing of surface plasmons on a Schottky diode-terminated tapered tip of nanoscale dimensions allows for a plasmon-to-hot-electron conversion efficiency of ∼30%. We further demonstrate that, with such high efficiency, hot electrons can be used for a new nanoscopy technique based on an atomic force microscopy set-up. We show that this hot-electron nanoscopy preserves the chemical sensitivity of the scanned surface and has a spatial resolution below 50 nm, with margins for improvement.

12.
Opt Express ; 19(22): 22268-79, 2011 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-22109069

RESUMEN

We report on the possibility of realizing adiabatic surface plasmon polaritons compression on metallic conical tips built-in on AFM cantilevers by means of different approaches. The problem is faced considering the role of the source, when linear and radial polarizations are assumed, associated to different fabrication schemes. Nano-patterned devices properly combined with metallic conical tips can affect the adiabatic characteristic of the surface electric field. The results are analyzed in terms of tradeoff between fabrication difficulties and device performances. Suggestions on the best possible scheme are provided.


Asunto(s)
Metales/química , Microscopía de Fuerza Atómica/instrumentación , Microscopía de Fuerza Atómica/métodos , Cristalización , Electricidad , Rayos Láser , Nanoestructuras/química , Fotones , Propiedades de Superficie
13.
Dig Liver Dis ; 39(6): 507-15, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17383244

RESUMEN

Decompensated liver cirrhosis is characterized by a peripheral vasodilation with a low-resistance hyperdynamic circulation. The sustained increase of cardiac work load associated with such a condition may result in an inconstant and often subclinical series of heart abnormalities, constituting a new clinical entity known as "cirrhotic cardiomyopathy". Cirrhotic cardiomyopathy is variably associated with baseline increase in cardiac output, defective myocardial contractility and lowered systo-diastolic response to inotropic and chronotropic stimuli, down-regulated beta-adrenergic function, slight histo-morphological changes, and impaired electric "recovery" ability of ventricular myocardium. Cirrhotic cardiomyopathy is usually clinically latent or mild, likely because the peripheral vasodilation significantly reduces the left ventricle after-load, thus actually "auto-treating" the patient and masking any severe manifestation of heart failure. In cirrhotic patients, the presence of cirrhotic cardiomyopathy may become unmasked and clinically evident by certain treatment interventions that increase the effective blood volume and cardiac pre-load, including surgical or transjugular intrahepatic porto-systemic shunts, peritoneo-venous shunts (LeVeen) and orthotopic liver transplantation. Under these circumstances, an often transient overt congestive heart failure may develop, with increased cardiac output as well as right atrial, pulmonary artery and capillary wedge pressures.


Asunto(s)
Cardiomiopatías/complicaciones , Cirrosis Hepática/complicaciones , Cardiomiopatías/diagnóstico , Cardiomiopatías/patología , Cardiomiopatías/terapia , Corazón/fisiopatología , Humanos , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/patología , Cirrosis Hepática/terapia
15.
Biol Cybern ; 60(1): 1-16, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3214648

RESUMEN

Motor control in primates relates to a system which is highly redundant from the mechanical point of view--redundancy coming from an imbalance between the set of independently controllable variables and the set of system variables. The consequence is the manifestation of a broad class of ill-posed problems, problems for which it is difficult to identify unique solutions. For example (i) the problem of determining the coordinated patterns of rotation of the arm joints for a planned trajectory of the hand; (ii) the problem of determining the distribution of muscle forces for a desired set of joint torques. Ill-posed problems, in general, require regularization methods which allow to spell acceptable, if not unique, solutions. In the case of the motor system, we propose that the basic regularization mechanism is provided by the potential fields generated by the elastic properties of muscles, according to an organizational principle that we call "Passive Motion Paradigm". The physiological basis of this hypothesis is reviewed and a "Kinematic Network" (K-net) model is proposed that expresses the kinematic transformations and the causal relations implied by elasticity. Moreover, it is shown how K-nets can be obtained from a kinematic "Body Model", in the context of a specific task. Two particularly significant results are: (i) the uniform treatment of closed as well as open kinematic chains, and (ii) the development of a new method for the automatic generation of kinematic equations with arbitrary topology. Moreover, the model is akin to the concept of "motor equivalence" in the sense that it provides families of motor equivalent trajectories parametrized by tunable motor impedances.


Asunto(s)
Cibernética , Movimiento , Fenómenos Biomecánicos , Elasticidad , Humanos , Articulaciones/fisiología , Modelos Anatómicos , Modelos Biológicos , Músculos/fisiología
16.
Tissue Cell ; 13(2): 403-11, 1981.
Artículo en Inglés | MEDLINE | ID: mdl-7314076

RESUMEN

In the integument of the red-spotted newt there occasionally appear patches of skin which are at the same time melanistic and iridescent. Such hyperpigmented patches have been found on the back, on the tail and on the dorsal surface of both fore and hind limbs. Cytological examination of several such areas revealed the presence of large numbers of chromatophores distributed throughout the dermis. The majority of the chromatophores consisted of atypically large and dendritic melanophores, which contained typical pigment granules. The iridescence resulted from a high incidence of iridophores. Xanthophores also were found in considerable abundance. This extensive and apparently random intermingling of melanophores, iridophores and xanthophores in limited areas constitutes a striking exception to the usual distributional patterns of pigment cells in this animal.


Asunto(s)
Cromatóforos/ultraestructura , Notophthalmus viridescens/anatomía & histología , Salamandridae/anatomía & histología , Piel/ultraestructura , Animales , Epidermis/ultraestructura , Melanóforos/ultraestructura , Microscopía Electrónica , Pigmentación
17.
Biol Cybern ; 38(3): 125-40, 1980.
Artículo en Inglés | MEDLINE | ID: mdl-7448252

RESUMEN

A study of the fundamental principles upon which manipulation dexterity is based cannot help mixing robotic and neurophysiological concepts. A preliminary step in this study consists of trying to understand the complexity of manipulation dynamics. Though complexity shows itself in the massive number of elements of kinematic and dynamic equations, the fundamental simplicity of the underlying mechanical laws suggests to look for a structure, particularly from the computational point of view. Accordingly, a working computational model is proposed that organizes the massive computational load into a structure which is composed of a small number of computational units and lends itself to parallel computation.


Asunto(s)
Cibernética , Movimiento , Brazo/fisiología , Computadores , Humanos , Matemática , Métodos , Modelos Neurológicos , Articulación del Hombro/fisiología
18.
Biol Cybern ; 38(3): 141-50, 1980.
Artículo en Inglés | MEDLINE | ID: mdl-7448253

RESUMEN

An important factor in trying to capture the complexity of many manipulation problems is the notion of Output Motor Impedance, i.e., the relationship between a set of disturbing forces and the resulting variation in arm configuration. The functional significance of such force/displacement characteristics is investigated, showing how several aspects of different manipulation tasks (holding against gravity, inserting, fast moving, and throwing) can be naturally described in terms of appropriate modulation of the impedance characteristics of the manipulator. For this reason, impedance modulation can be considered an integral part of motor control.


Asunto(s)
Cibernética , Movimiento , Brazo/fisiología , Computadores , Humanos , Matemática , Modelos Neurológicos
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