191 research outputs found

    Philosophy and updating of the asteroid photometric catalogue

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    The Asteroid Photometric Catalogue now contains photometric lightcurves for 584 asteroids. We discuss some of the guiding principles behind it. This concerns both observers who offer input to it and users of the product

    Resurfacing capitate pyrocarbon implant as salvage procedure in several serious outcomes of carpal injuries. Clinical experience and follow-up

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    Background and aim: Resurfacing Capitate Pyrocarbon Implant has been introduced in the surgical practice as an alternative method to restore wrist motion, strength and functions in patients suffering from wrist osteoarthritis. It has already been well described in the literature as a treatment for advanced stages of degenerative wrist diseases which follow scaphoid’s and lunate’s injuries such as scapho-lunate advanced collapse, scaphoid non-union advanced collapse, and advanced stages of Kienböck disease. Authors extended the use of RCPI to other selected cases of complicated wrist injuries, spreading out from the classic indications for which this device was designed. Methods: We discuss 8 cases with serious outcomes of carpal injuries treated with Resurfacing Capitate Pyrocarbon Implant as salvage procedure between 2005 and 2013 by the first author of this paper. Results: Among the eight particular selected cases, at a mean 4.3 years follow-up (range 2-11) only one was considered a failure and underwent a total wrist arthrodesis, resolving pain after all. The seven other cases reported good results. Range of Motion, Visual Analogue Scale for pain, subjective satisfaction and radiographical outcomes are reported. Conclusions: As a result of this heterogeneous clinical experience, validated by long-term follow-ups in most cases, we think that the use of a Resurfacing Capitate Pyrocarbon Implant can be suggested as an option in the outcomes of various carpal injuries

    Resurfacing capitate pyrcarbon implant after proximal row carpectomy: A literature review camillo fulchignoni daniele caviglia lorenzo rocchi

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    Up to a decade ago, to treat patients with chronic wrist pain due to advanced stages of arthritis, surgeons had four main solutions: partial or total wrist arthrodesis, total wrist prosthesis and proximal row carpectomy (PRC). Since 2010, a new technique has been described in literature using the Resurfacing Capitate Pyrocarbon Implant (RCPI), combined to PRC. The aim of this article is to review the literatureand determine the indications, outcomes and complications associated with RCPI. An electronic literature research was carried out and pertinent articles were selected. Surgical technique, results and complications described in those articles are presented. From this review of the literature, authors conclude that Resurfacing Capitate Pyrocarbon Implant can be considered as a good alternative to arthrodesis and total wrist arthroplasty, at any ages, when proximal row carpectomy alone would not be indicated

    United States and Western Europe cooperation in planetary exploration

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    A framework was sought for U.S.-European cooperation in planetary exploration. Specific issues addressed include: types and levels of possible cooperative activities in the planetary sciences; specific or general scientific areas that seem most promising as the main focus of cooperative efforts; potential mission candidates for cooperative ventures; identification of special issues or problems for resolution by negotiation between the agencies, and possible suggestions for their resolutions; and identification of coordinated technological and instrumental developments for planetary missions

    Chronic post-traumatic volar plate avulsions of the finger proximal interphalangeal joint: A literature review of different surgical techniques

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    Avulsions of the volar plate of the finger proximal interphalangeal joint (PIPJ) following sprains are often undiagnosed in the acute setting. Therefore, the chronic outcomes of this injury are most frequently the object of study and treatment. Different techniques for volar plate chronic avulsion repair are described in the literature. The most used among these are mainly two: the direct suturing with or without the use of bone anchors and the tenodesis techniques with flexor digitalis superficialis (FDS). The aim of this systematic review is to determine outcomes and complications associated with these surgical treatments of post-traumatic volar plate avulsions without phalangeal fractures. An electronic literature research was carried out and pertinent articles were selected. Surgical techniques details, outcomes and complications for direct sutures and tenodesis technique are discussed. Outcomes (Range of motion and pain) seem to be comparable, whereas authors that use the direct suture technique describe more frequently PIPJ flexion contracture complication. From this review of the literature, authors believe that both techniques are available for the repair of chronic injuries of the volar plate of the PIPJ, although direct suturing can be considered as less reproducible

    First albedo determination of 2867 Steins, target of the Rosetta mission

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    We present the first albedo determination of 2867 Steins, the asteroid target o f the Rosetta space mission together with 21 Lutetia. The data were obtained in polarimetric mode at the ESO-VLT telescope with the FORS1 instrument in the V and R filters. Observations were carried out from Jun e to August 2005 covering the phase angle range from 10.3 deg. to 28.3 deg., allowing the determination of the asteroid albedo by the well known experimenta l relationship between the albedo and the slope of the polarimetric curve at th e inversion angle. The measured polarization values of Steins are small, confirming an E-type cla ssification for this asteroid, as already suggested from its spectral propertie s. The inversion angle of the polarization curve in the V and R filters is resp ectively of 17.3 +/-1.5deg. and 18.4+/-1.0 deg., and the corresponding sl ope parameter is of 0.037+/-0.003 %/deg and 0.032+/-0.003 %/deg. On the basis of its polarimetric slope value, we have derived an albedo of 0.45 +/-0.1, that gives an estimated diameter of 4.6 km, assuming an absolute V ma gnitude of 13.18 mag.Comment: 4 pages, 4 figures, letter accepted for pubblication on A&

    Versatility of the perforator radial artery flap in the reconstruction of the upper limbs and comparison of the outcomes with the “classic” radial flap, a retrospective study

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    Introduction: Radial forearm flap, first described in the early eighties in China, is a well-known and handy flap to cover soft tissue defects of the distal upper limb. It has, though, some inconveniences, such as the sacrifice of the radial artery and non-neglectable esthetic sequelae in the donor site. In the following years, a similar flap based on the perforators of the radial artery has been described as achieving similar results, allowing to spare a main vessel. The authors reviewed retrospectively the patients that underwent surgery with one of those two flaps in their center to compare outcomes. Materials and methods: Patients operated between January 2016 and January 2022 have been reviewed. Ten had a classic radial artery flap, and ten had a radial artery perforator flap. Twelve weeks after surgery, Vancouver Scar Scale was used to assess the results at the donor site and over the flap. Reintervention and failure rate within one year and patient satisfaction -using a visual analog scale ranging from 0 to ten-at 12 months were also assessed. Results: All classic radial artery flap group patients had “successful” surgery, and none needed secondary surgery. On the other side, three patients required a second surgery in the perforator flap group, and nine out of ten ended up with “successful” flaps. Mean Vancouver Scar Scale results regarding the flap are comparable, whereas those at the donor site are significantly better in the patients with the perforator flap. Patients’ satisfaction results are similar in both groups. Conclusion: The radial artery perforator flap is an important flap to be held in mind by all surgeons approaching reconstruction of the elbow, the forearm, and the hand, and should be preferred, when possible, to the classic radial forearm flap

    Inhomogeneities on the surface of 21 Lutetia, the asteroid target of the Rosetta mission

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    CONTEXT: In July 2010 the ESA spacecraft Rosetta will fly-by the main belt asteroid 21 Lutetia. Several observations of this asteroid have been so far performed, but its surface composition and nature are still a matter of debate. For long time Lutetia was supposed to have a metallic nature due to its high IRAS albedo. Later on it has been suggested to have a surface composition similar to primitive carbonaceous chondrite meteorites, while further observations proposed a possible genetic link with more evolved enstatite chondrite meteorites. AIMS: In order to give an important contribution in solving the conundrum of the nature of Lutetia, in November 2008 we performed visible spectroscopic observations of this asteroid at the Telescopio Nazionale Galileo (TNG, La Palma, Spain). METHODS: Thirteen visible spectra have been acquired at different rotational phases. RESULTS: We confirm the presence of a narrow spectral feature at about 0.47-0.48 micron already found by Lazzarin et al. (2009) on the spectra of Lutetia. We also find a spectral feature at about 0.6 micron, detected by Lazzarin et al. (2004) on one of their Lutetia's spectra. More importantly, our spectra exhibit different spectral slopes between 0.6 and 0.75 micron and, in particular, we found that up to 20% of the Lutetia surface could have flatter spectra. CONCLUSIONS: We detected a variation of the spectral slopes at different rotational phases that could be interpreted as possibly due to differences in the chemical/mineralogical composition, as well as to inhomogeneities of the structure of the Lutetia's surface (e.g., the presence of craters or albedo spots) in the southern hemisphere.Comment: 3 pages, 2 figures. Accepted for publication in Astronomy and Astrophysics. Updated on 25 March 2010

    Resurfacing Capitate Pyrocarbon Implant for the treatment of advanced wrist arthritis in the elderly: a retrospective study

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    OBJECTIVE: Advanced forms of wrist osteoarthritis in the elderly are quite common and often under-treated, preferring a conservative management of the condition due to the age of the patient. However, in elderly people who are still active, sporty and physically demanding, surgical management of wrist osteoarthritis should be considered. Proximal Row Carpectomy associated with a Resurfacing Capitate Pyrocarbon Implant (RCPI), allows the management of a wide range of wrist arthrosis, involving both the radio-carpal and the mid-carpal joints. This treatment has been already reported as a solution in younger people affected by degenerative pathologies of the wrist, giving overall good results. Authors aimed at verifying how this technique could be useful in elderly patients, resolving the severe pain often related to this pathology and letting them recover strength and motion. PATIENTS AND METHODS: This is a retrospective analysis involving 7 cases of elderly men (mean age = 68 y.o.), suffering from severe wrist arthritis and treated with RCPI between 2016 and 2021. RESULTS: All patients reported a return to manual activities between 6 and 12 months after surgery, significantly improving pain. Two patients complained moderate pain under strain at follow-up, with residual difficulty in performing manual tasks. In all cases, an increase of strength and improvement in terms of stiffness was registered. No cases of infections or implant mobilization were reported. CONCLUSIONS: RCPI combined with proximal row carpectomy shows satisfying results in all published studies and it has been confirmed in our series as well. Indications for this procedure should be widened to elderly people, as useful alternatives to more aggressive salvage procedures, such as total prosthesis or arthrodesis

    Colors and taxonomy of Centaurs and Trans-Neptunian Objects

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    The study of the surface properties of Centaurs and Trans-Neptunian Objects (TNOs) provides essential information about the early conditions and evolution of the outer Solar System. Due to the faintness of most of these distant and icy bodies, photometry currently constitutes the best technique to survey a statistically significant number of them. Our aim is to investigate color properties of a large sample of minor bodies of the outer Solar System, and set their taxonomic classification. We carried out visible and near-infrared photometry of Centaurs and TNOs, making use, respectively, of the FORS2 and ISAAC instruments at the Very Large Telescope (European Southern Observatory). Using G-mode analysis, we derived taxonomic classifications according to the Barucci et al. (2005a) system. We report photometric observations of 31 objects, 10 of them have their colors reported for the first time ever. 28 Centaurs and TNOs have been assigned to a taxon. We combined the entire sample of 38 objects taxonomically classified in the framework of our programme (28 objects from this work; 10 objects from DeMeo et al. 2009a) with previously classified TNOs and Centaurs, looking for correlations between taxonomy and dynamics. We compared our photometric results to literature data, finding hints of heterogeneity for the surfaces of 4 objects.Comment: 7 pages, 4 figures. To be published in Astronomy and Astrophysic
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