130,548 research outputs found
Towards a chemo-mechanical approach to landslide stabilization
No full textClay-rich soils are widespread throughout the globe. Their mechanical properties can be deeply affected by the chemical composition of the pore fluid. As an example, Fig. 1a shows the residual friction angle evaluated on specimens of an illitic soil of marine origin, in equilibrium with the natural pore fluid, with distilled water or with two different salt solutions at different concentrations. In loessic soils too, which can contain up to 30% of clay – mainly illite – the magnitude of the chemo-mechanical effects has been shown to be noticeable (Fig. 1b). Several Authors (see Scaringi, 2016) hypothesized connections between changes in pore fluid chemistry and activity of some types of landslides in clay soils. In a slow earthflow in a marine clay formation, Di Maio et al. (2015) showed that the pore ion concentration can decrease significantly from the depth towards the ground surface (Fig. 1c). Thus, different parts of the landslide shear zone may exhibit different values of shear strength parameters. Natural and anthropic processes (e.g. exposure to rain water, irrigation water, freshwater from confining aquifers) can cause the concentration to decrease further over time, leading to further weakening which can produce shear displacements (Di Maio and Scaringi, 2016). On the other hand, an increase of pore solution concentration, e.g. through ion diffusion from salt piles (Di Maio et al., 2016; 2017) can produce strength increase (as in Fig. 1a). The role of chemo-mechanical coupling in the initiation and movement of landslides in clay soils should be evaluated explicitly, as it can be fundamental for a correct assessment and management of the landslide risk. Furthermore, applications of the chemo-mechanical concepts can lead to innovative and environment-friendly solutions of landslide stabilization, based, for instance, on engineered modifications of the clay behavior driven through the pore fluid chemistry
Transition metal-catalyzed alkene isomerization as an enabling technology in tandem, sequential and domino processes
No full textOne-pot reactions elaborated around transition metal-catalyzed isomerization of alkenes not only offer the inherent advantages of atom-, step-and redox-economy but also enable the preparation of value-Added products that would be difficult to access by conventional methods. In this Review, we cover seminal and recent examples of tandem, sequential and domino processes, which incorporate the most attractive features of olefin isomerization
Data for 3D reconstruction and point cloud classification using machine learning in cultural heritage environment
No full textUnmanned Aerial Vehicle (UAV) photogrammetry, thanks to the development of Structure from Motion (SfM) and Multi-View Stereo (MVS) algorithms, allows the generation of dense point clouds, capable of representing three-dimensional objects and structures in a detailed and accurate manner. In addition, the possibility of associating more semantic information through automatic segmentation and classification models, becomes of fundamental importance in the field of development, protection and maintenance of Cultural Heritage (CH). With the developments in Artificial Intelligence (AI), classification algorithms based on Machine Learning (ML) have been developed. In particular, the Random Forest is used in order to perform a semantic classification of the point cloud generated by UAV photogrammetry and Global Navigation Satellite Systems (GNSS) survey of a structure belonging to CH environment. Indeed, this paper describes the images collected through a UAV survey, for 3D reconstruction of Temple of Hera (Italy) based on photogrammetric approach and georeferenced by the use of 8 Ground Control Points (GCPs) acquired by GNSS survey. In addition, the shared dataset contains the point cloud and data for classification using Random Forest algorithm
Stereotactic Irradiation of GH-Secreting Pituitary Adenomas
No full textRadiotherapy (RT) is often employed in patients with acromegaly refractory to medical and/or surgical interventions in order to prevent tumour regrowth and normalize elevated GH and IGF-I levels. It achieves tumour control and hormone normalization up to 90% and 70% of patients at 10–15 years. Despite the excellent tumour control, conventional RT is associated with a potential risk of developing late toxicity, especially hypopituitarism, and its role in the management of patients with GH-secreting pituitary adenomas remains a matter of debate. Stereotactic techniques have been developed with the aim to deliver more localized irradiation and minimize the long-term consequences of treatment, while improving its efficacy. Stereotactic irradiation can be given in a single dose as stereotactic radiosurgery (SRS) or in multiple doses as fractionated stereotactic radiotherapy (FSRT). We have reviewed the recent published literature on stereotactic techniques for GH-secreting pituitary tumors with the aim to define the efficacy and potential adverse effects of each of these techniques
Inactivated Candida albicans and immunostimulation. P. Marconi, L. Scaringi, L. Tissi, A. Cassone, F. Bistoni. In: Agriculture. Adjuvants, Interferon and Non-Specific Immunity. Report EUR 8675 EN. (F.M. Cancellotti and D. Galassi Eds.). pp. 143-152, 1984.
No full textStereotactic irradiation of GH-secreting pituitary adenomas
No full textRadiotherapy (RT) is often employed in patients with acromegaly refractory to medical and/or surgical interventions in order to prevent tumour regrowth and normalize elevated GH and IGF-I levels. It achieves tumour control and hormone normalization up to 90 and 70 of patients at 10-15 years. Despite the excellent tumour control, conventional RT is associated with a potential risk of developing late toxicity, especially hypopituitarism, and its role in the management of patients with GH-secreting pituitary adenomas remains a matter of debate. Stereotactic techniques have been developed with the aim to deliver more localized irradiation and minimize the long-term consequences of treatment, while improving its efficacy. Stereotactic irradiation can be given in a single dose as stereotactic radiosurgery (SRS) or in multiple doses as fractionated stereotactic radiotherapy (FSRT). We have reviewed the recent published literature on stereotactic techniques for GH-secreting pituitary tumors with the aim to define the efficacy and potential adverse effects of each of these techniques. Copyright © 2012 G. Minniti et al
Burst-induced spin variations in the accreting magnetic white dwarf PBC J0801.2–4625
No full textPBC J0801.2–4625 is an intermediate polar with a primary spin frequency of 66.08 d−1 and an unknown orbital period. The long-term All Sky Automated Survey for Supernovae (ASAS-SN) light curve of this system reveals four bursts, all of which have similar peak amplitudes (∼2 mag) and durations (∼2 d). In this work, we primarily study the timing properties of this system’s 2019 February burst, which was simultaneously observed by both ASAS-SN and the Transiting Exoplanet Survey Satellite (TESS). Pre-burst, a frequency of 4.064 ± 0.002 d−1(5.906 ± 0.003 h period), likely attributed to the binary orbit, is identified in addition to previous measurements for the white dwarf’s spin. During the burst, however, we find a spin frequency of 68.35 ± 0.28 d−1. Post-burst, the spin returns to its pre-brust value but with a factor 1.82 ± 0.05 larger amplitude. The burst profile is double-peaked, and we estimate its energy to be 3.3 × 1039 erg. We conclude that the burst appears most consistent with thermonuclear runaway (i.e. a’micronova’), and suggest that the spin variations may be an analogue to burst oscillations (i.e.’micronova oscillations’). However, we also note that the above findings could be explained by a dwarf nova outburst. With the available data, we are unable to distinguish between these two scenarios.</p
Single Crown Restorations Supported by One-Piece Zirconia Dental Implants: Case Series with a Mean Follow-Up of 58 Months
No full textThe main aim of this case series was to report the clinical and radiographic outcomes of 22 one-piece zirconia dental implants positioned in 19 patients to restore single edentulisms and followed up for at least 2 years. The mean observation period was 58.18 months. At the last follow-up visit, no issues, such as foreign body sensation, discomfort or pain, were reported by the patients. No implant showed signs of infection with suppuration or implant mobility. Marginal bone levels (MBL) were assessed through standardized dental radiographs and a dedicated software. The mean distance between the implant head and the first detectable bone to implant contact was calculated at the mesial and distal aspect of each implant. The mean MBL at baseline was 1.82 ± 0.63 mm while the mean MBL at the last follow-up visit was 2.57 ± 0.72 mm. The results obtained in the present case series over a mean follow-up period of 58.18 months (range 27–96) showed that one-piece zirconia dental implants could be an alternative option to support single crowns in patients requiring metal-free restorations. Nevertheless, further better-controlled research featuring an adequate study design and longer follow-up is needed in order to clarify advantages and limitations which are related to this treatment modality
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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