240 research outputs found
Ultra-high, broadband gain in a lattice-engineered, Yb-doped double tungstate channel waveguide
150 dB/cm gain over 55 nm wavelength range between 977-1032 nm is obtained in a 47.5% Yb-doped potassium double tungstate waveguide amplifier. The dependence of luminescence lifetime and gain on Yb concentration is investigated
A Microfluidic Device Based on Standing Surface Acoustic Waves for Sorting and Trapping Microparticles
Microfluidic devices can provide innovative means to handle and control the transport of
(bio)particles within a fluid flow. The advantage of microscale devices is that different components
can be integrated in a single chip at low cost, with a negligible power consumption, compared to
alternative solutions. In this work, a numerical investigation is developed on the use of standing
surface acoustic waves (SAWs) generated within a microfluidic channel in order to manipulate
microparticles. Far-field waves are generated via inter-digital transducers (IDTs), travel on the surface
of a piezoelectric substrate and finally interfere in the channel, giving rise to a standing wave solution
in terms of acoustic pressure. Results are reported for different geometries of the channel, to define
the sensitivity of the acoustic pressure field to the relevant geometric features of the channel. This
investigation shows how the acoustic radiation and drag forces interact with each other to move and
focus the particles, possibly leading to a separation of heterogeneous ones, and generally provide a
way to manipulate them at a small scale
Meningeal solitary fibrous tumour in a child.
INTRODUCTION: Meningeal solitary fibrous tumour is a relatively recent pathological entity that has rarely been described in children. With radiological techniques, it cannot be distinguished from meningiomas, and the diagnosis has to be confirmed histologically. CASE REPORT: We discuss the possible histogenesis of this tumour and the need for recognizing this lesion as a separate entity. We report the case of a 12-year-old boy who developed a meningeal solitary fibrous tumour; the main clinical symptoms were progressive headaches for a long period and recent transient hemiparesis. CONCLUSION: This child presents an uneventful evolution without additional therapy 3.5 years after surgery
Optimising the follow-up of adult coeliac disease with a clinical-based score to identify patients in need of a histological reassessment: a retrospective single centre study.
AbstractFollow-up modalities for adult coeliac patients remain controversial. Non-invasive markers to identify coeliac patients on a gluten-free diet (GFD) with persistence of villous atrophy (VA) are still lacking. We aim to develop a score to stratify coeliac patients on a GFD according to their risk of having persistent VA and to tailor follow-up modalities accordingly. The clinical notes of over 700 coeliac patients attending our unit (September 1999âNovember 2018) were retrospectively examined. A total of 273 patients on a GFD with a histological follow-up performed 12â24 months after diagnosis were selected. We developed a bivariable model based on diet adherence and clinical response evaluated by previously validated methods. A four-level score (0·5, 1·5, 3, 4) was obtained. Patients on a strict GFD and with good clinical conditions (score 4) have a very low risk of persistence of VA (2 (95 % CI 1, 5) %). Conversely, the risk is very high (46 (95 % CI 25, 68) %) in patients with poor adherence to a GFD and unsatisfactory clinical response (score 0·5). A score of 1·5 (poor GFD adherence and persistent well-being) is linked with a high risk (23 (95 % CI 14, 36) %). Risk is intermediate (6 (95 % CI 3, 10) %) in patients scoring 3 (strict GFD and no/partial clinical improvement). Three patients who developed complications belonged to this scenario. Patients at low risk of persistent VA can be followed-up non-invasively, whereas a biopsy should be repeated in those at high/very high risk. Case-by-case evaluation is needed in patients at intermediate risk. Studies on a larger sample size are required to confirm these data
Diketopyrrolopyrrole-fullerene C60 architectures as highly efficient heavy atom-free photosensitizers: Synthesis, photophysical properties and photodynamic activity
Chromophore-fullerene C60 hybrids possess interesting properties that enable them to act as heavy atom-free photosensitizers and reactive oxygen species (ROS) producers. Here, two new diketopyrrolopyrrole-C60 conjugates were efficiently synthesized and characterized. The conjugates show broadband absorption in the visible spectral region, in which diketopyrrolopyrrole dyes act as light-harvesting antenna with very high capacity to populate excited triplet states. Furthermore, the ability of diketopyrrolopyrrole-C60 systems to generate singlet molecular oxygen was explored for the first time in solvents of different polarities. The experimental results show that these architectures exhibit very high production rates of this ROS. In addition, a preliminary study on Staphylococcus aureus cell suspensions indicates that both conjugates exhibit phototoxicity after irradiation with green LED light. Thus, the data obtained provide evidence that these diketopyrrolopyrrole-C60 architectures act as potential heavy atom-free photosensitizers in photodynamic inactivation of microorganisms and other singlet oxygen-mediated applications.Fil: Agazzi, Maximiliano Luis. Universidad Nacional de RĂo Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Almodovar, Vitor A. S.. Universidade de Aveiro; PortugalFil: Gsponer, Natalia Soledad. Universidad Nacional de RĂo Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Bertolotti, Sonia Graciela. Universidad Nacional de RĂo Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: TomĂ©, Augusto C.. Universidade de Aveiro; PortugalFil: Durantini, Edgardo NĂ©stor. Universidad Nacional de RĂo Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentin
Is there a role for âmodified VADâ in the treatment of multiple myeloma?
VAD, (Vincristine, Doxorubicin and Dexamethasone) was initially proposed as a salvage therapy for myeloma patients in whom prior alkylating agent therapy failed, although in recent years VAD has been surpassed by novel combination therapies with new biological agents such as thalidomide (and its derivative, lenalidomide) and bortezomib. After the excellent results obtained by the novel agents, VAD can no longer be proposed in preparation to autologous transplantation, although there are still indications that VAD remains useful and clinically relevant in the initial treatment of symptomatic multiple myeloma
Realism and the wave-function
Realism -- the idea that the concepts in physical theories refer to 'things'
existing in the real world -- is introduced as a tool to analyze the status of
the wave-function. Although the physical entities are recognized by the
existence of invariant quantities, examples from classical and quantum physics
suggest that not all the theoretical terms refer to the entities: some terms
refer to properties of the entities, and some terms have only an epistemic
function. In particular, it is argued that the wave-function may be written in
terms of classical non-referring and epistemic terms. The implications for
realist interpretations of quantum mechanics and on the teaching of quantum
physics are examined.Comment: No figure
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