bluuebunny/crossref_metadata_2025 huggingface dataset:
La técnica como forma de estar bien en el mundo: consideraciones en Ortega y Blumenberg
Authors: Balaguer García Esmeralda
Published: August 2023

A partir del contexto que la crisis de la modernidad delimita, la función de la técnica ha sido objeto de controversia en el pensamiento del siglo XX. Esta aportación pretende dar cuenta de la concepción que Ortega y Blumenberg tuvieron de la técnica y de cómo se articula esa idea en su filosofía. A su vez, también pretende establecer los puntos de unión que existen en las ideas sobre la técnica que ambos filósofos defendieron en tanto que estas ideas tienen validez para pensar hoy nuestra realidad. La comprensión de la técnica como el medio propio del ser humano para la realización de su proyecto vital y para su autoafirmación ofrece una mirada positiva frente a discursos que demonizan la técnica.
Las lecturas de Martin Heidegger de la Ética a Nicómaco. En torno a unas glosas manuscritas custodiadas en la Universidad de Salamanca
Authors: Martín Gómez María
Published: August 2023

Este artículo analiza las lecturas que realizó Martin Heidegger de la Ética a Nicómaco de Aristóteles a partir de las anotaciones y subrayados que se conservan en un ejemplar que perteneció al filósofo alemán y que actualmente se custodia en la Biblioteca Histórica de la Universidad de Salamanca. Las diversas notas y glosas manuscritas que Heidegger anota al margen de las páginas en la obra de Aristóteles permiten conocer mejor la influencia que este libro ejerció en la filosofía heideggeriana y descubren que «el taller histórico y filológico» que Martin Heidegger instauró a partir del texto aristotélico fue crucial para el desarrollo de algunos conceptos fundamentales de su pensamiento.
Ortega y la genética. Aportaciones del pensamiento de Ortega y Gasset a la discusión ético-filosófica sobre la edición genética
Authors: Alonso Fernández Marcos
Published: August 2023

La mejor manera de mostrar la relevancia de filósofos del pasado es utilizar su pensamiento para abordar problemas del presente. En este artículo se utiliza el pensamiento de Ortega y Gasset (1883-1955) para tratar las implicaciones ético-filosóficas de la edición genética. Tras una breve introducción a la edición genética y su situación actual, se analiza la relación entre el pensamiento de Ortega y la genética en dos planos. En primer lugar, mostrando cómo algunos planteamientos orteguianos -como la noción de falta de naturaleza, de sobrenaturaleza, o de autofabricación- podrían servir para establecer unas bases filosóficas desde las que comprender el impacto de las tecnologías de edición genética en seres humanos. En segundo lugar, exponiendo varios puntos concretos del debate en torno a la edición genética en los que las ideas de Ortega resultan valiosas, como sería su respuesta al proyecto transhumanista y su contextualización histórica de las tecnologías de edición genética.
Justicia algorítmica y autodeterminación deliberativa
Authors: Innerarity Daniel
Published: August 2023

Si la democracia consiste en posibilitar que todas las personas tengan iguales posibilidades de influir en las decisiones que les afectan, las sociedades digitales tienen que interrogarse por el modo de conseguir que los nuevos entornos hagan factible esa igualdad. Las primeras dificultades son conceptuales: entender cómo se configura la interacción entre los humanos y los algoritmos, en qué consiste el aprendizaje de estos dispositivos y cuál es la naturaleza de sus sesgos. Inmediatamente después nos topamos con la cuestión ineludible de qué clase de igualdad estamos tratando de asegurar, teniendo en cuenta la diversidad de concepciones de la justicia que hay en nuestras sociedades. Si articular ese pluralismo no es un asunto que pueda resolverse con una técnica agregativa, sino que requiere compromisos políticos, entonces una concepción deliberativa de la democracia parece la más apta para conseguir esa igualdad a la que aspiran las sociedades democráticas.
Resonancia natural y capacidad individual de acción ecosocial
Authors: Moreno-Romero Pablo , Ballesteros Virginia
Published: August 2023

Transformar el modo de vida individual es necesario para abordar la crisis ecosocial, y resulta perentorio que las políticas comprometidas con su resolución promocionen una capacidad individual de acción ecosocial. Sin embargo, parece que cierta brecha motivacional está obstaculizando la transformación del modo de vida individual. A fin de dar respuesta a esta brecha, ensayamos una mixtura del enfoque de las capacidades con las teorías de Hartmut Rosa. Argumentamos que la resonancia natural funge de factor personal de conversión necesario, si bien no suficiente, para la capacidad de acción ecosocial; y que una política que promocione la resonancia natural se adecuaría también a los requisitos impuestos al desarrollo humano tanto por el enfoque de las capacidades como por la sostenibilidad.
¿Por qué el hombre no tiene naturaleza? La figura del animal fantástico como respuesta en el pensamiento de Ortega
Authors: De Haro Honrubia Alejandro
Published: August 2023

Las siguientes páginas versan sobre el valor que el filósofo español José Ortega y Gasset (1883-1955) concedió en su obra de madurez intelectual a la fantasía o la imaginación como dimensión fundamental de la vida humana como realidad radical que nos permite trascender, aunque sea a costa de convertirnos en tránsfugas o desertores de nuestra propia animalidad, nuestra propia naturaleza instintiva e irracional. Nuestra argumentación pivotará en torno a la conocida tesis del filósofo español que dice que «el hombre no tiene naturaleza, sino que tiene... historia», que es, según Ortega, esforzarse en realizar lo imaginario, lo que nos permite hablar del ser humano como animal fantástico, estando aquí la clave de este trabajo.
Conserver à l’heure du consommable
Authors: Dazord Cécile
Published: August 2023

L’introduction de produits de consommation courante dans les œuvres contemporaines est avérée et largement commentée par l’histoire de l’art. La spécificité de ces objets, dont certains sont des consommables, c’est-à-dire des ressources qui, intégrées dans un dispositif, peuvent produire un fonctionnement, et dont la durée d’exploitation est limitée, introduit, dans le champ de la conservation-restauration, fondé sur l’unicité de la matérialité de l’œuvre comme garante de son originalité, un changement de paradigme décisif que les phénomènes d’obsolescence technologique contribuent à mettre en évidence.
L’exigence de pérennité à l’epreuve de l’art contemporain
Authors: Heinich Nathalie
Published: August 2023

La pérennité est une valeur fondamentale dans la conception occidentale de l’art, qui exige de l’œuvre qu’elle soit doublement durable : et par rapport au passé (c’est l’ancienneté), et par rapport au futur (c’est la postérité). L’exigence de pérennité est centrale dans l’activité et la déontologie muséologiques. Mais les choses se compliquent avec l’art contemporain : la perte de pérennité n’y est plus, en effet, accidentelle ou liée aux atteintes du temps, mais elle peut être consubstantielle au projet même de l’artiste. Dans ces conditions, ce n’est pas seulement la pérennité des œuvres qui est mise en cause, mais le travail permettant leur pérennisation – et en particulier le travail des restaurateurs.D’où des conflits récurrents sur la pérennité de l’œuvre, dont la complexité tient aussi à ce qu’elle n’est pas la seule des valeurs en jeu : c’est aussi la question de l’authenticité qui se trouve posée là, ainsi que la question de l’autorité de l’artiste sur le devenir de son œuvre. Il faut toutefois distinguer entre les aléas de la mise en œuvre factuelle de la valeur de pérennité et la constance de cette valeur en tant que principe de jugement des objets, des personnes, des actions. Or il est clair que, même mise à l’épreuve par les expérimentations des artistes, la valeur de pérennité demeure active non seulement pour le sens commun et pour les spécialistes, mais aussi pour les artistes eux-mêmes.
Les collections du Centre Pompidou et l’obsolescence
Authors: Sorano-Stedman Véronique
Published: August 2023

Plusieurs domaines des collections du Centre Pompidou, les installations et les objets, la photographie, le design et la création industrielle, le cinéma et les nouveaux médias, sont concernés par les technologies en voie de disparition.L’enrichissement des collections et l’augmentation des besoins de maintenance de ces œuvres ont ainsi conduit au milieu des années 1980 à la création, dans les services techniques du Centre Pompidou, d’un atelier électromécanique. Une collaboration systématique avec le service de la restauration et la conservation a permis d’amorcer des procédures indispensables à cette gestion. Il est actuellement assez difficile d’effectuer un recensement précis du nombre de matériaux ou de supports affectés par le problème dans les collections du MNAM. L’état des lieux repose donc actuellement sur la gestion des stocks concernant des œuvres « phares » couramment présentées ou réclamées en prêt. Le cas de Denkifuku d’Atsuko Tanaka illustre les principes de collaboration entre restaurateurs, électromécaniciens, conservateurs et le choix des protocoles mis en place. L’équipe de restauration intervient principalement dans plusieurs contextes : les acquisitions, la présentation en salle et les prêts. La démarche comporte un aspect préventif (évaluation des besoins de mise en réserve d’un stock de composants consommables de rechange et surveillance des risques d’obsolescence et d’usure de l’œuvre) et un aspect curatif.Une véritable déontologie reste à définir sur le modèle de base de la restauration. Sur le plan préventif, la constitution d’un stock de composants de rechange comporte des contraintes très lourdes à gérer pour un établissement muséal. D’où l’intérêt de développer des réseaux d’échange entre les institutions françaises et internationales. Le rôle d’un service de restauration intégré à l’institution muséale est primordial. Le choix comme les compromis entre les exigences d’équilibre de la forme et du sens sont familiers aux restaurateurs, qui peuvent malgré tout transposer certains principes de la déontologie générale régissant le patrimoine ancien et traditionnel, aux œuvres modernes et contemporaines, et contribuer à l’application d’un degré minimaliste d’intervention, respectueux de la dimension historique.
Time-based media art conservation: status update
Authors: Ryan Gwynne
Published: August 2023

A status update on conservation of time-based media art, mainly from North America and Europe, this article presents the available resources, the institutions involved, the pertinent projects and the challenges over the last decade. A wider development of this field enables us to question the preservation of the intangible and argues for a specific education for conservators.
La photographie contemporaine sous le regard de la conservation et de la restauration : le cas du « Plan couleur et impressions numériques » de la Ville de Paris
Authors: Cartier-Bresson Anne , Blanc Maud
Published: August 2023

Bien qu’à l’origine de toute photographie, analogique ou numérique, il y ait l’empreinte de la lumière sur un support sensible, la « révolution numérique » a changé la manière d’appréhender ce médium.Dans ce contexte, l’Atelier de restauration et de conservation des photographies de la Ville de Paris (ARCP) a lancé, en 2006, un plan de conservation portant sur les photographies en couleurs photochimiques et les impressions numériques conservées dans les institutions municipales.Les différentes techniques recensées sont celles qui constituent majoritairement la production contemporaine, des tirages à développement chromogène aux impressions jet d’encre, en passant par les tirages argento-numériques.Mais au-delà de l’identification des procédés photographiques, cruciale pour la conservation des fonds, les problématiques de montage et de présentation spécifiques de la photographie contemporaine sont apparues tout aussi importantes.Ces dernières décennies, des avancées en matière de restauration et de montage ont été réalisées, en adaptant les pratiques aux nouveaux matériaux. Dans certains cas cependant, les collections ont encore recours au retirage des œuvres endommagées. Cette solution ne constitue pas une alternative définitive, notamment face à l’obsolescence des supports.Finalement, le numérique n’a pas fondamentalement modifié nos pratiques de conservation-restauration et son avenir résiderait, comme pour les procédés photochimiques, et davantage encore, dans la prévention.
La numérisation du patrimoine photographique : virtualisation et déréalisation de l’original
Authors: Lopez Jean-Gabriel
Published: August 2023

Les numérisations des collections photographiques sont maintenant des opérations courantes. L’uniformisation de la demande et l’abaissement des coûts tendent vers une standardisation de la représentation qui va quelquefois à l’encontre de la fragilité et de la complexité de la photographie et des intérêts multiples qu’elle suscite. Cette situation avantage la photographie pour ce qu’elle représente d’immatériel et ne valorise pas toujours l’objet patrimonial.
Le suivi des œuvres en mouvement du MNAM-CCI. État des lieux
Authors: Lorenzen Astrid
Published: August 2023

Les collections du MNAM-CCI comportent de nombreuses œuvres animées par des mouvements. Face à la complexité des mouvements, des techniques, des matériaux de création et de mise en mouvement, la documentation de l’œuvre semble le point essentiel pour tenter de mettre en place des stratégies de conservation de ce groupe d’œuvres.C’est à partir d’une documentation complète, qui permet de faire appel à des spécialistes dans des domaines aussi variés que les techniques employées sur l’œuvre, que le restaurateur et le conservateur peuvent aborder les nombreuses questions de la conservation des œuvres en mouvement et tenter de proposer des réponses et des solutions en commençant par de nombreuses interrogations. La création de l’atelier électromécanique dans les années 1980 au sein du musée a été déterminante. Le résultat des échanges et des collaborations entre services, en particulier celui des électromécaniciens, est généralement très satisfaisant et des solutions réalistes, parfois innovantes et, de plus en plus performantes, sont trouvées. Les œuvres sont aujourd’hui suivies la plupart du temps par des restaurateurs. La réparation des moteurs est préférée à leur remplacement. Elle est confiée aux derniers artisans encore capables de rebobiner des moteurs. La pose de « pièces d’usure » et de « semelles sacrificielles » est privilégiée afin de préserver des parties originales de l’œuvre. L’emballage, le stockage, la mise en mouvement, les temps de fonctionnement, les conditions de présentation sont étudiés et adaptés à la fragilité des œuvres. Il reste bien sûr beaucoup à faire et, avec l’augmentation de la collection du musée et l’implication de plus en plus importante du service de la restauration dans la gestion de la collection, il est donc fondamental de poursuivre la documentation et l’étude approfondie de ces œuvres en mouvement.
Obsolescence and film restoration : the case of colored silent films
Authors: Fossati Giovanna
Published: August 2023

Elsewhere I have discussed the transitional nature of film and argued that the current shift from analog to digital technology is one of the many transitional phases that film has experienced in its history as a technology, a popular form of entertainment and art. The obsolescence brought about by the shift to digital technologies certainly complicates our possibility of experiencing original artifacts of the past. This is true also for other forms of art from the twentieth century that are linked to serial and industrial production, and is certainly true for film and for film after restoration. If obsolescence affects film as an artifact, it does not necessarily affect the way we experience it after restoration. This line of reasoning can be exemplified by the specific case of color in silent cinema. This contribution discusses how new technologies offer alternative solutions for the restoration of obsolete coloring practices typical of silent cinema, and how, in some cases, they can even improve our viewing experience compared to traditional restoration techniques.
« L’étude préalable », inventaire et analyse structurée d’une œuvre préalablement à sa mise en circulation pour un prêt : entretien avec Isabelle Merly
Authors: Merly Isabelle , Breuil Marie-Hélène , Dazord Cécile
Published: August 2023

Isabelle Merly présente le travail mené dans le cadre de « l’étude préalable » au prêt des œuvres de la collection du Centre Pompidou et la constitution d’une documentation analytique qui comprend l’inventaire de l’ensemble des éléments, la liste de colisage, les indications de montage et démontage. Cette approche pragmatique et méthodique permet d’aller d’une vue d’ensemble à l’étude du détail sans séparer le concept de l’œuvre de sa matérialité.
Variation of Semi-Solid Microstructure and Mechanical Properties of Mg98.5Ni0.5Y1.0 Alloy with Solidification Pressure
Authors: Wu Shu Sen , Lü Shu Lin , Yang Xiong , Guo Wei
Published: August 2023

A semisolid slurry of Mg98.5Ni0.5Y1.0 alloy was prepared by UV (ultrasonic vibration) method, then the slurry was cast under different squeeze pressures, in which the pressure varied from 0 MPa to 400 MPa. The results show that the primary α-Mg phase and LPSO structure (Long Period Stacking Ordered structure) of the alloy can be refined significantly. The solid solubility of Y and Ni elements in magnesium matrix can be increased with higher pressure, and the Mg2Ni particles is also precipitated out in LPSO structure under pressure. The grain size is decreased with the enhancement of squeeze pressure, which improves the strength. The alloy squeeze cast under pressure of 100 MPa has the highest cost performance. Its yield strength, tensile strength and elongation are 115 MPa, 243 MPa and 13.5%, and they are increased by 21.5%, 9.0% and 16.4% respectively compared with the alloy without applied pressure.
Semi-Solid Casting of AlN Reinforced Mg-Matrix Composites and their Thermophysical Properties
Authors: Chen Lu , Qin Ji An , Li Jian Yu , Lü Shu Lin , Guo Wei , Wu Shu Sen
Published: August 2023

AlN has high thermal conductivity (TC) and low coefficient of thermal expansion (CTE), which is an ideal reinforcement phase for strengthening the thermophysical properties of magnesium alloys to be used as packaging substrate material. However, the poor wettability between AlN and magnesium melt makes the preparation of AlN/Mg composites with high AlN content very difficult. In this work, the AlN/Mg-5Zn-4.9Cu composites were prepared by semi-solid stir casting method to address this problem, and the effect of AlN particle content on the thermophysical properties of the composites was investigated. The results show that AlN can reduce the CTE of magnesium alloy significantly and weaken the TC of magnesium alloys slightly. When 20 wt.% of AlN was added, the TC of the composites was 125.1 W/(m·K) and the CTE was only 19.83×10-6 K-1, which was 26.7% lower than that of the matrix alloy.
Development of High Strength and High Thermal Conductivity Semi-Solid Magnesium Alloy by Thixomolding Process
Authors: Gu Li Dong , Shang Xiao Qing , Wang Jie , Deng Jun Jun , Liu Yu Peng , Zeng Xiao Qin , Ding Wen Jiang
Published: August 2023

This paper investigates the influence of Cu addition on the microstructure, mechanical properties, and thermal conductivity of a semi-solid Mg-10Zn alloy produced by Thixomolding process. Microstructure of the Mg-10Zn alloy consists of α-Mg matrix and Mg2Zn second phase. The formation of Cu3Zn phase was found after the addition of Cu particles. Besides, the volume fraction of solid phase decreased in the Mg-Zn/Cu alloy compared with that of binary Mg-Zn alloy. The yield strength of the alloy was enhanced from 157MPa to 188MPa after Cu addition at the sacrifice of a small amount of ductility. Thermal conductivity, on the other hand, were kept the same level of 115-117 (W/m·K) in the Mg-10Zn alloy and Mg-10Zn/Cu alloy. This work demonstrates the potential for developing Mg alloys with high strength and high thermal conductivity via proper alloy design using Thixomolding process.
Effect of Ingate Length on Microstructure and Properties of Semi-Solid Squeeze Casting CuSn10P1 Alloy
Authors: Zhang Hao , Li Yong Kun , Li Zhao Qiang , Wang Qian Shi , Xie Ling Zhi , Zhang Ling Zhi , Zhou Rong Feng , Xiao Han
Published: August 2023

It is easy to occur solid-liquid separation during semi-solid rheological forming, which leads to poor uniformity of microstructure and properties and limits its application in high strength and toughness parts. In this paper, a semi-solid CuSn10P1 alloy slurry was prepared by an enclosed cooling slope channel (for short ECSC). The effect of ingate length on microstructure and properties by semi-solid squeeze casting was studied. The results showed that the proper increase of the length of the ingate is beneficial to improve the uniformity of the microstructure and properties of the semi-solid squeeze casting. The microstructure uniformity and properties are the best when the ingate length is 20mm. The ultimate tensile strength and elongation of semi-solid squeeze casting CuSn10P1 alloy with 20 mm ingate length reached 419.2 MPa and 13.4%.
Heat-Treatment Characteristics and Structure-Property Relationships of Thixomolded AZ91 and Ultralight LAZ771 Magnesium Alloys
Authors: Lai Tzu Yu , Hu Si Yuan , Kuo Yi Yang , Su Te Cheng
Published: August 2023

Most magnesium alloys are produced by die casting due to their formability issues, but the thixomolding process has recently drawn considerable attention in manufacturing magnesium alloy casings for 3C electronic devices with lower porosity levels. This study compared the mechanical properties and microstructure of thixomolded AZ91 and ultra-light LAZ771 magnesium alloy for thin laptop cases. The experimental results firstly show that the microstructure of as-thixomolded samples contains fine αMg grains and a divorced eutectic network. After solution heat treatment, the ductility is improved due to the dissolution of the non-equilibrium secondary phases. Secondly, microstructural characterization for samples after aging treatment shows that the Mg17Al12 precipitates in AZ91 can be classified into continuous (CPs) and discontinuous precipitates (DPs) according to their morphologies. On the other hand, the AlLi precipitates in LAZ771 after aging treatment are spherical and incoherent with the αMg matrix. Those AlLi precipitates obstruct basal slip of dislocations in αMg matrix more effectively than Mg17Al12, resulting in higher yield strength of peak-aged LAZ771 specimens than heat-treated AZ91 specimens.
Preliminary Investigation on the Use of Recycled A356 Alloy for Semi-Solid Processing
Authors: Mantelli Anna , Arcaleni Riccardo , Girelli Luca , Tonelli Lavinia , Montesano Lorenzo , Pola Annalisa
Published: August 2023

The continuous demand for lightweighting vehicles leads to a significant increase in the use of aluminium alloys in the automotive sectors. The Al-Si-Mg aluminium alloys are widely applied in foundry processes to produce structural components, due to their high specific mechanical properties combined with good castability and corrosion resistance. Primary (from bauxite) alloys are often used to ensure the highest quality of such parts, nevertheless their production route causes high CO2 emissions. With the goal of reducing cradle-to-grave emissions of vehicles secondary (from recycling) Al-Si-Mg alloys are often used for cast products, however their percentage of impurities is considered too high for structural components. Lately, some Al-Si-Mg recycled alloys with a low content of Fe are available on the market as an alternative to primary alloys. Alongside the traditional foundry processes, semi-solid techniques are known to be able to increase the performance of Al-Si alloys. In this paper, a preliminary microstructural and mechanical characterization of secondary A356 alloys, manufactured by the ultrasound semi-solid method, was performed. In detail, both high Fe and low Fe recycled A356 alloys were investigated in comparison to the traditional primary one. The effect of the T6 heat treatment was also taken into account.
Numerical Simulations of the Squeeze Flow of Thixotropic Semisolid Slurries
Authors: Florides Georgios C. , Georgiou Georgios C. , Modigell Michael , Zoqui Eugênio José
Published: August 2023

We propose a methodology for the rheological characterization of semisolid metal slurries using experimental squeeze flow data. The material is modelled as a structural thixotropic viscoplastic material, obeying the regularized Herschel-Bulkley constitutive equation. The yield stress and the power-law exponent are assumed to vary with the structural parameter that is governed by a first-order kinetics. The squeeze flow is simulated using finite elements in a Lagrangian framework. The evolution of the sample height has been studied for all the ranges of the Bingham and Reynolds numbers, the power-law exponent as well as the kinetics parameters of the structural parameter. Systematic comparisons have been carried out with experimental data on a semisolid aluminium alloy (A356) sample, compressed from its topside at a temperature of 582 °C under a specified load, which eventually becomes constant. Excellent agreement with the experimental data could be achieved provided that at the initial instances (up to 0.01s) of the experiment the applied load is much higher than the nominal experimental load and that the yield stress and the power-law exponent vary linearly with the structural parameter. The first requirement implies that a different model should be employed during the initial stages of the experiment. As for the second one, the evolution of the sample height can be reproduced allowing the yield stress to vary from 0 (no structure) to a maximum nominal value (full structure) and the power-law exponent from 0.2 to 1.4.
Rheological Behavior in the Semisolid State of Al-Si-Cu Alloys Produced by ECAP
Authors: Torres Luis Vanderlei , Proni Cecilia Tereza Weishaupt , Zoqui Eugênio José
Published: August 2023

It is fundamental in thixoforming to have a refined microstructure that, when heated to the semisolid state, consists of a mixture of small spheres immersed in liquid as this ensures the best rheological properties. The present work therefore aims to analyze the rheological behaviour of aluminum-silicon-copper alloys, namely, Al5Si2.8Cu, Al6Si2.8Cu and Al7Si2.8Cu. The alloys were produced by conventional casting and then deformed by ECAP in one pass in a die containing two channels of the same cross-sectional area forming an angle of 120°. After being processed by ECAP, the alloys were heated to semisolid temperatures, i.e., temperatures corresponding to a solid fraction of 45 %, and kept in the semisolid state for 0, 30 and 90 s, after which they were subjected to hot compression tests. The structures of the three alloys had an excellent response to recovery and recrystallization mechanisms, with refined microstructures that led to the formation of very fine spheres immersed in liquid in the semisolid state. The best rheological behaviour was obtained for the Al5Si2.8Cu alloy, which had an apparent viscosity of the order of 103 Pa.s. The findings suggest that this simple ECAP process is a promising route for the production of semisolid feedstock for use in thixoforming.
Apalutamide-induced ichthyosiform eruption
Authors: Ciolfi Christian , Lunardon Anna , Cassalia Fortunato , Alaibac Mauro
Published: August 2023

Not available
Stroke and the Bovine Aortic Arch
Authors: Samadhiya Swapnil , Maheshwari Dilip , Sardana Vijay , Bhushan Bharat
Published: August 2023

Aim and Objectives:

We aimed to find the prevalence of bovine aortic arch in stroke and non-stroke patients and to study the relationship between bovine aortic arch and the occurrence of stroke.

Materials and Methods:

One hundred patients with and without stroke underwent computed tomography (CT) angiography of the thoracic aorta and its arch. Fifty diffusion-weighted magnetic resonance imaging (MRI)-confirmed anterior circulation stroke patients who had undergone digital subtraction angiography (DSA) afterward formed the case group. As controls, another 50 patients who had thoracic CT angiograms for disease other than stroke during this time period were randomly selected. Demographics and prevalence of bovine arch were compared between cases and controls. In the case group, demographics and prevalence of bovine arch variants and their relationship to stroke were studied.

Results:

Prevalence of bovine aortic arch variant in anterior circulation stroke was 22%, compared to 6% in non-stroke patients (P = 0.043). The bovine aortic arch was associated with the younger onset of stroke occurrence (P = 0.046). In the bovine arch group, the proportion of left-sided strokes (P = 0.022) and bilateral strokes (P < 0.00001) was significantly higher. As compared to type A (P = 0.140), type B bovine aortic arch had a better association (P = 0.092).

Conclusions:

Bovine aortic arch is a risk factor for young-onset anterior circulation stroke. Bilateral and left-sided infarcts were more common. Endovascular procedures are difficult to perform through conventional routes, so brachioradial access is preferred.
Biotin-Responsive Basal Ganglia Disease
Authors: Oommen Abel Thomas , Polavarapu K , Christopher R , Netravathi M
Published: August 2023

Background and Aims:

Biotin-thiamine-responsive basal ganglia disease (BTBGD) is an autosomal recessive disorder due to mutations in the SLC19A3-gene, typically seen in early childhood.

Materials and Methods:

We report a 49-year-old lady presenting with rapidly progressive cognitive impairment, seizures, hypersomnolence, ataxia, and generalized dystonia of 3 weeks duration. The magnetic resonance imaging (MRI) of the brain revealed T2-hyperintensities in the basal ganglia, thalamus, cortical, subcortical regions with striatal necrosis suggestive of BTBGD that was confirmed by genetic analysis. She was treated with thiamine and biotin following which there was significant clinical and MRI improvement.

Conclusions:

BTBGD requires a high index of suspicion in any patient presenting with unexplained rapidly progressive dementia. High doses of biotin and thiamine are the mainstay of the treatment to achieve a favorable outcome.
Novel Compound Heterozygous Mutation in PANK2 in a Patient with an Atypical Form of Pantothenate Kinase Associated Neurodegeneration and His Family
Authors: Yuan Jing , Zhanga Canling , Qiao Shan , Wang Aihua , Zhang Shanchao
Published: August 2023

Pantothenate kinase-associated neurodegeneration (PKAN) is an autosomal-recessive disease characterized by iron accumulation in the brain due to PANK2 gene mutation. The typical “eye-of-the-tiger” sign is the characteristic manifestation of brain magnetic resonance imaging (MRI). We report a Chinese patient with atypical PKAN whose brain MRI scans displayed the typical “eye-of-the-tiger” sign in bilateral pallidum. Genetic analysis identified a compound heterozygous mutation (c. 629-2A > T, c. 1130T > C) for the PANK2 gene. These two mutations were further demonstrated in his parents and other relatives.
Microsurgical Excision of Vestibular Schwannoma with Facial Nerve Preservation
Authors: Roopesh Kumar VR , Karthikayan Arunkumar , Sanjeevi Venkatesan , Saranyan R
Published: August 2023

Background:

This video highlights the standard surgical steps of retrosigmoid craniotomy and excision of a moderately sized vestibular schwannoma with facial nerve preservation, with basic technical nuances to guide young neurosurgeons.

Objective:

A systematic step-by-step approach to microsurgical dissection and removal of vestibular schwannoma that achieves gross total excision with good facial nerve preservation.

Methods:

The video starts with a note on clinical presentation of a 45-year-old male with unilateral sensorineural hearing loss and headache with MRI brain showing a 3.8 × 3.0 cm schwannoma arising from the left vestibular nerve. The surgery was performed in lateral position with neuromonitoring, using a conventional retrosigmoid craniotomy. The essential surgical steps of arachnoid opening and extra capsular dissection, identification and preservation of facial nerve, and drilling of the internal acoustic meatus (IAM) are demonstrated step by step achieving a gross total excision.

Results:

A systematic and meticulous approach to microsurgical excision of vestibular schwannoma is pivotal in the preservation of facial nerve and in preventing damage to surrounding neurovascular structures.

Conclusion:

Adopting microsurgical techniques in vestibular schwannoma with intraoperative facial nerve monitoring aids in achieving good functional outcome and tumor control.
A Rare Pathologic Collecting and Hoarding Behavior Following Left Middle Cerebral Artery Territory Infarction
Authors: Lee Minwoo , Kim Yeo J , Kim Yerim
Published: August 2023

Background and Significance:

Punding is the term used to describe complex, purposeless abnormal behaviors that are thought to be related to either excessive dopamine stimulation or inhibition. We report a case of punding after cerebral infarction at the caudate nucleus.

Case:

A 70-year-old man presented with acute-onset motor aphasia. Upon examination, he showed no other neurological deficit. The computed tomography scan and magnetic-resonance imaging scan taken during admission were consistent with acute infarctions of the left caudate nucleus and multiple scattered areas of multiple cortices. Six months after the episode, he gradually became disruptive and ill-tempered. He began to buy and collect assorted repair tools. In addition, he presented hoarding behavior by acquiring unnecessary goods and stacking them at his house.

Conclusion:

To the best of our knowledge, this is the first case of punding following an ischemic stroke at the caudate nucleus. Our case strengthens the hypothetical pathophysiology of punding, which may involve not only direct dopaminergic stimulation but also the dysregulation of the dopamine system.
Post-Covid Cerebral Mucormycosis, Varied Presentations and Surgical Strategies of a Newer Epidemic
Authors: Vijayasekhar Manda Venkata , Nagappa Vivek , Swaroop Kurumella Hema , Mithun Gorre , Achuith Ediga , Varaprasad Kadali Satya
Published: August 2023

Context:

During the challenging second wave of the COVID-19 pandemic, we encountered a most dreadful fungal infection in the form of COVID-associated mucormycosis (CAM), with a varied pattern of presentation from previous experience. Patients presented with simple fungal sinusitis or more complicated brain abscesses, and newer manifestations such as skull osteomyelitis. We report our findings and innovative treatment strategies used to manage this morbid condition.

Objectives:

To study the various presentations and surgical strategies in treating post-COVID rhino-orbito-cerebral mucormycosis (ROCM).

Settings and Design:

Observational cross-sectional study.

Methods and Materials:

From May to October 2021, 270 patients with CAM were admitted to Andhra Medical College Department of Neurosurgery, King George Hospital, Visakhapatnam, India. A cohort of 61 cases with intracranial involvement was studied in detail. The varied presentations and different or innovative treatment modalities were analyzed.

Results:

The death rate was 30/270 in the whole cohort, and three deaths (4.9%) occurred in 61 cases with cranial involvement. Thirty-three (54.1%) of the 61 cases were treated surgically: 17 patients required bone excision (for focal osteomyelitis) and 16 cases required abscess drainage/excision.

Conclusions:

Post-COVID mucormycosis (especially with intracranial involvement) is a highly challenging entity. A multidisciplinary approach with early and aggressive anti-fungal medication combined with timely surgical interventions offers some hope of overcoming this complex infection in CAM patients. We identified some novel techniques during regular follow-up that have proven helpful in combatting this devastating condition.
Recurrent IgG4-Related Meningeal Disease of the Cervicothoracic Spine
Authors: Kramer Dallas E. , Kerolus Mena G. , Furlan Karina , Nag Sukriti , O'Toole John E.
Published: August 2023

Background:

IgG4-related disease is a rare, recently recognized chronic inflammatory disease. IgG4-related hypertrophic pachymeningitis (IgG4-RHP) of the central nervous system predominantly involves the cranial meninges. Spinal involvement remains rare.

Objective:

We report a case of recurrent cervicothoracic IgG4-RHP and review the surgical literature.

Methods and Materials:

A 35-year-old woman presented with a 6-month history of neck and right shoulder pain, progressive right triceps weakness and paresthesias in the right C8 and T1 dermatomes. MRI demonstrated a T2 hypointense epidural soft tissue mass extending from C6-T1. The patient underwent C6-T1 laminoforaminotomy and partial resection with near complete symptom resolution. Histopathology was consistent with diagnosis of IgG4-RHP. Eighteen months postoperatively, she experienced symptom recurrence necessitating re-operation and adjuvant postoperative prednisone with complete resolution at 40-months' follow-up.

Results and Conclusions:

Of the now nineteen confirmed cases of IgG4-RHP, fifteen underwent surgery. A majority achieved partial resection. Three surgical patients did not receive adjuvant therapy with symptomatic recurrence between 2 and 18 months.
Challenges in Brain-Death Certification in India
Authors: Choudhary Devprakash , Sharma Ashish , Singh Sarbpreet , Ajay  , Kenwar Deepesh B , Jain Kajal , Chhabra Rajesh , Modi Manish , Saini Lokesh , Bansal Navdeep
Published: August 2023

The determination of Brain Death (BD)/Death by neurological criteria (DNC) is now widely accepted among various international societies following the World Brain Death project recommendation. As per the World Brain Death project, ancillary testing should be performed when standard brain-death examination components are inconclusive or cannot be performed. BD was defined legally in 1994 under the Transplantation of Human Organs Act (THOA). However, even after 27 years of the formulated law, there are no guidelines in the THOA regarding the determination of BD using ancillary tests. The present brief report describes two instances where ancillary tests like four-vessel angiography and transcranial doppler-aided brain-death certification were done. It is the first available literature from our country where ancillary tests aided in confirmation of BD when the standard clinical components of DNC could not be performed.
Effectiveness of Peripheral Median, Radial, and Ulnar Nerve Block at Wrist along with Intra-Articular Steroid Injection in Shoulder Joint in Management of Complex Regional Pain Syndrome of Upper Limb
Authors: Singh Ningthoujam J , Khanna Meeka , Gupta Anupam , Haldar Partha
Published: August 2023

Background:

Complex regional pain syndrome (CRPS) of upper limbs is one of the under-recognized painful disabling condition seen in many neurological conditions.

Objective:

To see the effectiveness of peripheral nerve blocks (PNB) along with intra-articular injection in shoulder joint in the improvement of pain, swelling and range of motion (ROM) of the upper limb in CRPS.

Methods:

It was a single-center, prospective study in male and female patients between 18 and 70 years with CRPS of the upper limb due to any etiology, within one year of illness. Single-dose of the intra-articular shoulder joint injection and peripheral nerve blocks at the wrist with steroid, 2% lignocaine, and sterile water was given. The primary outcome measure was a reduction in pain in the upper limb, assessed with a visual analog scale (VAS). Secondary outcome measures were an improvement in passive ROM of joints and a decrease in swelling of the hand. The significance of the P value was adjudged against an alpha of 0.05.

Results:

Thirty-three patients (25 men), with a mean (SD) age of 55.2 (9.4) years, and mean (SD) duration of illness of 101.9 (76.8) days were included. After 1 week, there was a significant improvement (P < 0.05) in the ROM of joints. The decrease in pain scores on VAS [mean difference -5.1 (CI -5.7, -4.5)] and reduction in hand swelling [mean difference -0.9 (CI -1.1, -0.7)] was also significant.

Conclusion:

Peripheral median, radial, and ulnar nerve block at wrist along with intra-articular steroid injection in the shoulder joint is an effective method of management of CRPS of the upper limb.
Effect of Tranexamic Acid on Blood Loss and the Quality of Surgical Field in Transsphenoidal Pituitary Surgeries
Authors: Lamsal Ritesh , Panda Nidhi B. , Wig Jyotsna
Published: August 2023

Background and Aims:

Pituitary adenomas are common intracranial neoplasms and several cases require surgery, radiotherapy or radiosurgery. Transsphenoidal access to the pituitary gland is the commonest surgical approach. In microscopic or endoscopic approach to the pituitary, even modest bleeding can significantly worsen the surgical field for the neurosurgeon, lengthen intra-operative time and lead to potentially catastrophic complications.

Methods:

The investigators hypothesized that administration of tranexamic acid (TXA) would improve the quality of the surgical field and reduce bleeding during transsphenoidal surgery (TSS) of pituitary tumors. Fifty American Society of Anesthesiologists (ASA) physical-status 1 or 2 patients undergoing TSS were randomized into two groups: T and P. Patients in Group T received 25 mg/kg bolus of TXA followed by intraoperative infusion of 1 mg/kg/hour, while those in Group P received a matching saline infusion. The operating neurosurgeon, and the anesthesiologist, who managed the patient and collected data, were blinded to the test drug. Surgical field quality was assessed using the Boezaart scale. A single neurosurgeon performed all the surgeries to ensure consistency in estimating the quality of the surgical field.

Results:

The median Boezaart score (interquartile range) was 3 (1.0) in Group T and 3.0 (1.5) in Group P (P = 0.03). There was an absolute blood loss reduction of nearly 32% with TXA use. Blood loss in Group T was 334 ± 101 mL, compared to 495 ± 226 mL in Group P (P = 0.002).

Conclusion:

The administration of TXA significantly improved the quality of surgical field and reduced blood loss in patients undergoing TSS.
Clinical Profile, Pathology, and Molecular Typing of Gliomas with Oligodendroglial Morphology
Authors: Lavanya Garapati , Uppin Megha Shantveer , Alugolu Rajesh , Bhattacharjee Suchanda , Saradhi Mudumba Vijaya , Yeramneni Vamsi Krishna
Published: August 2023

Background:

Diffuse gliomas are represented in the 2007 WHO classification of CNS tumors as astrocytomas, oligoastrocytoma, and oligodendroglioma of grades II/III and glioblastomas WHO grade IV, which was a pure morphologic classification. WHO 2016 classification combines morphology with molecular markers like IDH, ATRX, and 1p/19q codeletion to give an integrated diagnosis.

Methods:

The study was carried out on formalin fixed paraffin embedded tissues from 54 patients including three pediatric patients. Molecular studies were performed to know the 1p/19q codeletion status, IDH1R132H, and ATRX immunoexpression. Also, the IDH1R132H status was correlated with survival data.

Results:

The study included 54 tumors with oligodendroglial morphology. IDH1R132H positivity was seen in 85% of total cases and codeletion was seen in 72%. The integrated diagnosis revised the cases into oligodendroglioma (39), astrocytoma (5), and glioblastoma (6).IDH mutant tumors were found to have better survival than negative ones which was statistically significant.

Conclusion:

This study emphasizes the need for molecular work up of tumors with oligodendroglial morphology with readily available techniques like IHC and Fluorescence in situ hybridization.
Osteo-Cutaneous Trophic Changes in Complex Regional Pain Syndrome and their Reversal with Steroids
Authors: Pradhan Sunil , Bansal Robin , Das Animesh , Pardasani Vibhor , Malhotra Hardeep Singh , Kushwaha Suman , Mishra Vijay Nath
Published: August 2023

Background:

Complex regional pain syndrome (CRPS) is a chronic pain condition characterized by autonomic and inflammatory features. There is paucity of data regarding sustained benefits of any treatment modality. We aimed to document the effect of steroids in CRPS on long-term basis.

Materials and Methods:

We came across five patients of CRPS in Out Patient clinics of super-speciality Institutes in North India. All five cases fulfilled the Budapest criteria for the diagnosis of CRPS. All of them received prednisolone and were prospectively followed up for 2 years. Treatment outcome was carefully recorded in all affected modalities.

Results:

All five cases were found to have excruciating neuropathic pain in defined regions along with cutaneous manifestations. Osseous changes in the form of surface erosion of underlying bones in four cases and marked marrow edema leading to considerable increase in bone thickness in one case were noted. All these features improved considerably following steroid therapy. Bone marrow edema and bone resorption showed improvement on serial imaging.

Conclusion:

Apart from pain relief, steroids therapy is capable of reversing the osteo-cutaneous autonomic changes of CRPS type I.
Simplifying the Surgical Strategy for Excising Medial Sphenoid Wing Meningiomas
Authors: Roopesh Kumar VR , Madhugiri Venkatesh S. , Karthikayan Arunkumar , Ratha Vishwaraj , Bapu Suresh
Published: August 2023

Background:

Medial sphenoid wing meningiomas constitute 15%–20% of all intracranial meningiomas. These lesions have a propensity to encase the vessels of the circle of Willis and the surrounding cranial nerves. Thus, radical excision is a difficult proposition.

Objectives:

In this paper, we analyzed our series of sphenoid wing meningiomas. We describe our surgical strategy, which was based on zone-wise dissection of the tumor. We describe the complications and outcomes of surgery.

Materials and Methods:

This case series is a retrospective analysis of a single surgeon series of medial sphenoid wing meningiomas operated over a 13-year period. Clinical, radiographic, and outcome variables were studied. The surgical videos were analyzed in detail. The meningioma and its extensions were divided into several zones and a zone-wise strategy for tumor excision was evolved.

Results:

Twenty-four patients with medial sphenoid wing meningiomas were operated. In 14 patients, Simpson grade 3 excision could be achieved; 5 patients had Simpson grade 4 and 1 patient, grade 5 excision. Four (of 24 patients, 16.7%) had vessel injuries.

Conclusions:

Medial sphenoid wing meningiomas are difficult lesions to excise radically. Close follow-up of residual lesions (especially if attached to the basal dura) is warranted. Additional modalities of treatment like radiosurgery may be required in case of any progression and for higher-grade lesions.