Anharmonic properties of Raman modes in double wall carbon nanotubes

The temperature dependence of the radial breathing modes (RBMs) and the zone-center tangential optical phonons (G-bands) of double-walled carbon nanotubes (DWCNTs) has been investigated between 300 and 700 K using Raman scattering. As expected, with increasing temperature, the frequencies of the Raman peaks, including the RBMs and G-bands downshift simultaneously. We show here that the temperature dependence of the RBMs can be fitted by a simple linear dependence and different RBMs have different frequency shifts. We observe a noticeable nonlinearity in the temperature dependence of the G-band associated with the outer semiconducting tube (s). The deviation from the linear trend is due to the contribution of the third-order anharmonic term in the lattice potential energy with a pure temperature effect. An estimated value of 1.5 for the Grüneisen parameter of the (s) band was found.La variación con la temperatura de los modos de respiración radial (RBMs) y los fonones ópticos tangenciales de centro de zona (banda G) de los nanotubos de doble pared (DWCNTs) han sido investigados en el rango de 300 a 700 K utilizando dispersión Raman. Como era de esperarse, con el incremento de la temperatura las frecuencias de los picos Raman de los RBMs y las bandas G se desplazan hacia más bajas frecuencias. Nosotros demostramos que la variación con la temperatura de los RBMs puede ser ajustada mediante un modelo lineal y muestran diferentes desplazamientos en frecuencia. Nosotros observamos una no linealidad importante en la variación con la temperatura de la banda G asociada a los tubos semiconductores externos ¡ G + ext(s) ¢ . La desviación se debe a la contribución del término anarmónico de tercer orden en la energía potencial. Se encontró un valor estimado de 1,5 para el parámetro de Grüneisen de la banda G ¨ + ext(s)

Aplicación de aleaciones con memoria de forma en el diseño y fabricación de ferulajes para corrección de las deformidades articulares de los dedos de la mano

OBJETIVO: Se propone un prototipo de férula para la corrección de las deformidades articulares de los dedos de la mano, basados en las propiedades de las aleaciones de níquel-titanio, con el fin de mejorar la aplicación de las ortesis dinámicas de acción constante, empleadas habitualmente en ortopedia. MATERIAL Y MÉTODOS: Para ello, se han diseñado diferentes prototipos de láminas y varillas, variando sus grosores. Los prototipos se han aplicado a 15 pacientes con su consentimiento, deformidad en Boutonnière, entre 40 y 60º de angulación de la articulación interfalángica proximal (IFP) del dedo y edades comprendidas entre 18 y 39 años (media 31 años), midiendo cuando empieza a notarse un cambio en la fuerza tensil de la férula sobre la deformidad del dedo con el equipo Xpresion. RESULTADOS: Los valores obtenidos, son de 3291,67 ± 222,30 gr./mm 2, guardando relación directa con el diámetro del dedo. Los resultados obtenidos hasta conseguir una corrección superior al 75 %, han sido buenos en 9 pacientes, 5 regulares (corrección entre 30 % y 75 %) y uno malo (inferior al 30 %). CONCLUSIONES: Las férulas de Níquel Titanio con tensiones constantes durante largos periodos de tiempo, hasta recuperar la posición original, con su diseño, mejoran el ajuste inicial facilitando el manejo por parte del paciente y del especialista.Peer Reviewe

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate´s phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.J.T.S. holds a research contract from the Fundación para la Formación e Investigación de los Profesionales de la Salud de Extremadura (FundeSalud), Instituto de Salud Carlos III. M.F.R. holds a clinical research contract “Juan Rodés” (JR14/00036) from the Spanish Ministry of Economy and Competitiveness, Instituto de Salud Carlos III

Ultra-rare sarcomas: a consensus paper from the Connective Tissue Oncology Society community of experts on the incidence threshold and the list of entities

Background Among sarcomas, which are rare cancers, many types are exceedingly rare; however, a definition of ultra-rare cancers has not been established. The problem of ultra-rare sarcomas is particularly relevant because they represent unique diseases, and their rarity poses major challenges for diagnosis, understanding disease biology, generating clinical evidence to support new drug development, and achieving formal authorization for novel therapies.Methods The Connective Tissue Oncology Society promoted a consensus effort in November 2019 to establish how to define ultra-rare sarcomas through expert consensus and epidemiologic data and to work out a comprehensive list of these diseases. The list of ultra-rare sarcomas was based on the 2020 World Health Organization classification, The incidence rates were estimated using the Information Network on Rare Cancers (RARECARENet) database and NETSARC (the French Sarcoma Network's clinical-pathologic registry). Incidence rates were further validated in collaboration with the Asian cancer registries of Japan, Korea, and Taiwan.Results It was agreed that the best criterion for a definition of ultra-rare sarcomas would be incidence. Ultra-rare sarcomas were defined as those with an incidence of approximately <= 1 per 1,000,000, to include those entities whose rarity renders them extremely difficult to conduct well powered, prospective clinical studies. On the basis of this threshold, a list of ultra-rare sarcomas was defined, which comprised 56 soft tissue sarcoma types and 21 bone sarcoma types.conclusions Altogether, the incidence of ultra-rare sarcomas accounts for roughly 20% of all soft tissue and bone sarcomas. This confirms that the challenges inherent in ultra-rare sarcomas affect large numbers of patients.Experimentele farmacotherapi

Analytic expressions of the magnetoresistance due to localization and electron-electron interaction effects. - Application to the amorphous alloys La3Al and La3Ga

We start from the theoretical calculations of Alt'shuler et al. and Lee and Ramakrishnan for the contributions to magnetoresistance from weak localization and electron-electron interactions in a disordered system. We give analytic expressions which can be more easily handled by experimentalists. Our results on the amorphous alloys La3Al and La3Ga are presented and interpreted using these equations to get the best fit.Nous partons des calculs théoriques d'Alt'shuler et al. et de Lee et Ramakrishnan sur les contributions à la magnétorésistance de la localisation faible et des interactions électron-électron dans un système désordonné. Nous en donnons des formes analytiques d'utilisation facile pour les expérimentateurs. Nous présentons nos résultats expérimentaux sur les alliages amorphes La 3Al et La3Ga et nous les interprétons à partir des équations que nous avons obtenues

Localization effects in amorphous alloys under high magnetic field

Magnetoresistance measurements on metallic amorphous alloys constitute a good tool to study Anderson localization effects in three dimensional systems. The authors have performed measurements under high magnetic field (up to 32 T) on superconducting alloys (CuZr) and normal ones (VSi). They discuss the accuracy of theoretical models in presence of high field. They could determined the frequencies of inelastic and spin-orbit scatterings even when the spin-orbit coupling is stron

Stability of charge-ordering and H-T diagrams of RE1-xCaxMnO3 manganites in pulsed fields up to 50T

status: publishe

Temperatures and heat transfer on the impingement plane of a hot jet

SIGLEAvailable from British Library Document Supply Centre- DSC:3106.12862(TPRD/B--0977/R87) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Aplicación de aleaciones con memoria de forma en el diseño y fabricación de ferulajes para corrección de las deformidades articulares de los dedos de la mano

OBJETIVO: Se propone un prototipo de férula para la corrección de las deformidades articulares de los dedos de la mano, basados en las propiedades de las aleaciones de níquel-titanio, con el fin de mejorar la aplicación de las ortesis dinámicas de acción constante, empleadas habitualmente en ortopedia. MATERIAL Y MÉTODOS: Para ello, se han diseñado diferentes prototipos de láminas y varillas, variando sus grosores. Los prototipos se han aplicado a 15 pacientes con su consentimiento, deformidad en Boutonnière, entre 40 y 60º de angulación de la articulación interfalángica proximal (IFP) del dedo y edades comprendidas entre 18 y 39 años (media 31 años), midiendo cuando empieza a notarse un cambio en la fuerza tensil de la férula sobre la deformidad del dedo con el equipo Xpresion. RESULTADOS: Los valores obtenidos, son de 3291,67 ± 222,30 gr./mm 2, guardando relación directa con el diámetro del dedo. Los resultados obtenidos hasta conseguir una corrección superior al 75 %, han sido buenos en 9 pacientes, 5 regulares (corrección entre 30 % y 75 %) y uno malo (inferior al 30 %). CONCLUSIONES: Las férulas de Níquel Titanio con tensiones constantes durante largos periodos de tiempo, hasta recuperar la posición original, con su diseño, mejoran el ajuste inicial facilitando el manejo por parte del paciente y del especialista.Peer Reviewe

Magnetization of staggered S 1 2 antiferromagnetic Heisenberg chain systems

The molecule based S 1 2 antiferromagnetic Heisenberg chain systems Cu Pyrimidine Cu C4N2H4 NO3 2 H2O 2 and Cu Benzoate Cu C6H5COO 2 3H2O, because of the Dzyaloshinskii Moriya interaction and a staggering of the g tensor, are characterized by a magnetic principal axis system a amp; 8242; amp; 8242;bc amp; 8242; amp; 8242; distinct from the crystallographic unit cell. Along a amp; 8242; amp; 8242; a behavior corresponding to the uniform S 1 2 antiferromagnetic Heisenberg chain occurs, while along c amp; 8242; amp; 8242; the effect of g tensor staggering and Dzyaloshinskii Moriya interaction are most prominent. Here, we discuss the field and temperature dependent magnetization along a amp; 8242; amp; 8242; and c amp; 8242; amp; 8242; of these systems, in particular with respect to the relevance of the inhomogeneity parameter k controlling the ratio between longitudinal and transverse magnetization component