2,474 research outputs found
Spatiotemporal Amplitude and Phase Retrieval of Bessel-X pulses using a Hartmann-Shack Sensor
We propose a new experimental technique, which allows for a complete
characterization of ultrashort optical pulses both in space and in time.
Combining the well-known Frequency-Resolved-Optical-Gating technique for the
retrieval of the temporal profile of the pulse with a measurement of the
near-field made with an Hartmann-Shack sensor, we are able to retrieve the
spatiotemporal amplitude and phase profile of a Bessel-X pulse. By following
the pulse evolution along the propagation direction we highlight the
superluminal propagation of the pulse peak
Dye diffusion during laparoscopic tubal patency tests may suggest a lymphatic contribution to dissemination in endometriosis: A prospective, observational study
Aim Women with adenomyosis are at higher risk of endometriosis recurrence after surgery. This study was to assess if the lymphatic vessel network drained from the uterus to near organs where endometriosis foci lied. Methods A prospective, observational study, Canadian Task Force Classification II-2, was conducted at Sacro Cuore Don Calabria Hospital, Negrar, Italy. 104 white women aged 18–43 years were enrolled consecutively for this study. All patients underwent laparoscopy for endometriosis and a tubal dye test was carried out. Results Evidence of dye dissemination through the uterine wall and outside the uterus was noted in 27 patients (26%) with adenomyosis as it permeated the uterine wall and a clear passage of the dye was shown in the pelvic lymphatic vessels regardless whether the tubes were unobstructed. Histological assessment of the uterine biopsies confirmed adenomyosis. Conclusion Adenomyosis is characterized by ectatic lymphatics that allow the drainage of intrauterine fluids (the dye and, perhaps, menstrual blood) at minimal intrauterine pressure from the uterine cavity though the lymphatic network to extrauterine organs. Certainly, this may not be the only explanation for endometriosis dissemination but the correlation between the routes of the dye drainage and location of endometriosis foci is highly suggestive
Unidirectional decomposition method for obtaining exact localized waves solutions totally free of backward components
In this paper we use a unidirectional decomposition capable of furnishing
localized wave pulses, with luminal and superluminal peak velocities, in exact
form and totally free of backward components, which have been a chronic problem
for such wave solutions. This decomposition is powerful enough for yielding not
only ideal nondiffracting pulses but also their finite energy versions still in
exact analytical closed form. Another advantage of the present approach is
that, since the backward spectral components are absent, the frequency spectra
of the pulses do not need to possess ultra-widebands, as it is required by the
usual localized waves (LWs) solutions obtained by other methods. Finally, the
present results bring the LW theory nearer to the real experimental
possibilities of usual laboratories.Comment: 28 pages, 6 figure
Cardiovascular and Interventional Radiological Society of Europe Commentary on the Treatment of Chronic Cerebrospinal Venous Insufficiency
Chronic cerebrospinal venous insufficiency (CCSVI) is a putative new theory that has been suggested by some to have a direct causative relation with the symptomatology associated with multiple sclerosis (MS) [1]. The core foundation of this theory is that there is abnormal venous drainage from the brain due to outflow obstruction in the draining jugular vein and/or azygos veins. This abnormal venous drainage, which is characterised by special ultrasound criteria, called the “venous hemodynamic insufficiency severity score” (VHISS), is said to cause intracerebral flow disturbance or outflow problems that lead to periventricular deposits [2]. In the CCSVI theory, these deposits have a great similarity to the iron deposits seen around the veins in the legs in patients with chronic deep vein thrombosis. Zamboni, who first described this new theory, has promoted balloon dilatation to treat the outflow problems, thereby curing CCSVI and by the same token alleviating MS complaints. However, this theory does not fit into the existing bulk of scientific data concerning the pathophysiology of MS. In contrast, there is increasing worldwide acceptance of CCSVI and the associated balloon dilatation treatment, even though there is no supporting scientific evidence. Furthermore, most of the information we have comes from one source only. The treatment is called “liberation treatment,” and the results of the treatment can be watched on YouTube. There are well-documented testimonies by MS patients who have gained improvement in their personal quality of life (QOL) after treatment. However, there are no data available from patients who underwent unsuccessful treatments with which to obtain a more balanced view. The current forum for the reporting of success in treating CCSVI and thus MS seems to be the Internet. At the CIRCE office and the MS Centre in Amsterdam, we receive approximately 10 to 20 inquiries a month about this treatment. In addition, many interventional radiologists, who are directly approached by MS patients, contact the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) for advice. Worldwide, several centres are actively promoting and performing balloon dilatation, with or without stenting, for CCSVI. Thus far, no trial data are available, and there is currently no randomized controlled trial (RCT) in progress Therefore, the basis for this new treatment rests on anecdotal evidence and successful testimonies by patients on the Internet. CIRSE believes that this is not a sound basis on which to offer a new treatment, which could have possible procedure-related complications, to an often desperate patient population
Multidimensional virtual globe for geo big data visualization
In this paper, we presented a web application created using the NASA WebWorldWind framework. The application is capable of visualizing n-dimensional data using a Voxel model. In this case study, we handled social media data and Call Detailed Records (CDR) of telecommunication networks. These were retrieved from the "BigData Challenge 2015" of Telecom Italia. We focused on the visualization process for a suitable way to show this geo-data in a 3D environment, incorporating more than three dimensions. This engenders an interactive way to browse the data in their real context and understand them quickly. Users will be able to handle several varieties of data, import their dataset using a particular data structure, and then mash them up in the WebWorldWind virtual globe. A broad range of public use this tool for diverse purposes is possible, without much experience in the field, thanks to the intuitive user-interface of this web app
Local behavior of solutions of quasilinear elliptic equations with coefficients in Morrey spaces
In this paper we prove a Harnack inequality for some quasilinear elliptic equations, extending the results in [6] and [5]
Harnack inequality and regularity for degenerate quasilinear elliptic equations
We prove Harnack inequality and local regularity results for weak solutions
of a quasilinear degenerate equation in divergence form under natural growth
conditions. The degeneracy is given by a suitable power of a strong
weight. Regularity results are achieved under minimal assumptions on the
coefficients and, as an application, we prove local estimates
for solutions of a degenerate equation in non divergence form
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