1,310 research outputs found
Micrometre-scale refrigerators
A superconductor with a gap in the density of states or a quantum dot with
discrete energy levels is a central building block in realizing an electronic
on-chip cooler. They can work as energy filters, allowing only hot
quasiparticles to tunnel out from the electrode to be cooled. This principle
has been employed experimentally since the early 1990s in investigations and
demonstrations of micrometre-scale coolers at sub-kelvin temperatures. In this
paper, we review the basic experimental conditions in realizing the coolers and
the main practical issues that are known to limit their performance. We give an
update of experiments performed on cryogenic micrometre-scale coolers in the
past five years
Multidisciplinary approach in the management of a complex case: Implant-prosthetic rehabilitation of a periodontal smoking patient with partial edentulism, malocclusion, and aesthetic diseases
Complex periprosthetic cases are considered as challenges by clinicians. Clinical and radiographic parameters should be considered separately to make the right choice between an endodontically or periodontally compromised treated tooth and implant. Therefore, in order to decide whether the tooth is safe or not, data that have to be collected are specific parameters of both the patient and the clinician. In addition, the presence of periodontal, prosthetic, and orthodontic diseases requires patients to be set in multidisciplinary approach. The aim of this case report is to describe how the multidisciplinary approach could be the best way to manage difficult cases of implant-prosthetic rehabilitation. How to rehabilitate with fixed prosthesis on natural teeth and dental implants a smoker patient who presents with active periodontitis, multiple edentulous areas, dental malocclusion, and severe aesthetic problems was also described
Association of osteocalcin, osteoprotegerin, and osteopontin with cardiovascular disease and retinopathy in type 2 diabetes
Background: Novel biomarkers of vascular disease in diabetes could help identify new mechanistic pathways. Osteocalcin, osteoprotegerin, and osteopontin are key molecules involved in bone and vascular calcification processes, both of which are compromised in diabetes. We aimed to evaluate possible associations of osteocalcin, osteoprotegerin, and osteopontin with cardiovascular disease (CVD) and diabetic retinopathy (DR) among people with type 2 diabetes (T2D). Materials and methods: Osteocalcin, osteoprotegerin, and osteopontin concentrations were measured at enrolment in 848 participants with T2D from the Sapienza University Mortality and Morbidity Event Rate (SUMMER) Study (ClinicalTrials.gov: NCT02311244). Logistic regression models and propensity score matching were used to assess possible associations of osteocalcin, osteoprotegerin, and osteopontin with a history of CVD and with evidence of any grade of DR adjusting for confounders. Results: Previous CVD was reported in 139 (16.4%) participants, while 144 (17.0%) had DR. After adjusting for possible confounders, osteocalcin but not osteoprotegerin or osteopontin concentrations were associated with a history of CVD (Odds Ratio [OR] and 95% CI for one standard deviation (SD) increase in osteocalcin concentrations (natural log): 1.35 (1.06-1.72), p = 0.014). Associations with prevalent DR were seen for osteoprotegerin (OR for one SD increase in osteoprotegerin concentrations (natural log): 1.25 (1.01-1.55), p = 0.047) and osteopontin (OR for one SD increase in osteopontin concentrations (natural log): 1.25 (1.02-1.53), p = 0.022), but not osteocalcin. Conclusions: In T2D, higher serum osteocalcin concentrations are associated with macrovascular complications and higher osteoprotegerin and osteopontin concentrations with microvascular complications, suggesting that these osteokines might be involved in pathways directly related to vascular disease
Specific issues concerning the management of patients on the waiting list and after liver transplantation
The present document is a second contribution collecting the recommendations of an expert panel of transplant hepatologists appointed by the Italian Association for the Study of the Liver (AISF) concerning the management of certain aspects of liver transplantation, including: the issue of prompt referral; the management of difficult candidates; malnutrition; living related liver transplants; hepatocellular carcinoma; and the role of direct acting antiviral agents before and after transplantation. The statements on each topic were approved by participants at the AISF Transplant Hepatology Expert Meeting organized by the Permanent Liver Transplant Commission in Mondello on 12-13 May 2017. They are graded according to the GRADE grading system
Risk Analysis of the Future Implementation of a Safety Management System for Multiple RPAS Based on First Demonstration Flights
The modern aeronautical scenario has welcomed the massive diffusion of new key
elements, including the Remote Piloted Aircraft Systems (RPAS), initially used for military purposes
only. The current decade has seen RPAS ready to become a new airspace user in a large variety of
civilian applications. Although RPAS can currently only be flown into segregated airspaces, due to
national and international Flight Aviation Authorities′ (FAAs) constraints, they represent a
remarkable potential growth in terms of development and economic investments for aviation. Full
RPAS development will only happen when flight into non‐segregated airspaces is authorized, as
for manned civil and military aircraft. The preliminary requirement for disclosing the airspace to
RPAS is the implementation of an ad hoc Safety Management System (SMS), as prescribed by ICAO,
for every aeronautical operator. This issue arises in the context of the ongoing restructuring of
airspaces management, according to SESAR‐JU in Europe and NextGen in the USA (SESAR‐JU has
defined how RPAS research should be conducted in SESAR 2020, all in accordance with the 2015
European ATM Master Plan). This paper provides the basis to implement a risk model and general
procedures/methodologies to investigate RPAS safety, according to the operational scenarios
defined by EASA (European Aviation Safety Agency). The study is based on results achieved by
multiple‐RPAS experimental flights, performed within the RAID (RPAS‐ATM Integration
Demonstration) project
คาดการณ์การใช้ที่ดินลุ่มน้ำลำตะคอง พ.ศ. 2567 ด้วยแบบจำลอง CA-MARKOV
Prediction of Lamtakong Watershed Land Use in 2024 with CA-MARKOV Mode
The paleo-lacustrine diatomaceous deposits of Monte Amiata volcano (Tuscany, Italy) and the Ezio Tongiorgi paleontological collection in the Museum of Natural History of the University of Pisa
At the foothillof Monte Amiata volcano (southern Tuscany, Italy), small extinct lake basins of late Pleistocene age are documented. These lake basins were characterized by the deposition of two very different types of sediment: a) derived from the authigenic precipitation of iron oxides (goethite) and exploited as earth pigments; b) biogenic siliceous sediment composed of fossil diatoms and named diatomaceous earth or diatomite. The lacustrine sediments of Mount Amiata volcano were widely exploited for various applications since ancient times. Literary documents begin in the 16th century, with the descriptions of Cesalpino, Gesner, Agricola, and Imperato. Specific references to the diatomites of Monte Amiata are quoted in the 17th century by Boccone and Bonanno. The quarrying activity was described by Micheli in 1733. During the 18th and 19th centuries, the diatomaceous earths of Monte Amiata are part of the important geological collections of Micheli, Targioni Tozzetti, Baldassarri, Campani, and Tommi. A particular significance has the collection of botanic and ichthyologic fossils collected by Ezio Tongiorgi, and now preserved in the Museum of Natural History of the University of Pisa sited at the Charterhouse of Pisa in the Calci village. These paleontological samples preserve the biological and physical testimonies of the environmental and climatic changes of the late Pleistocene and are now particularly valuable because they are the only remaining evidence of the diatomaceous lacustrine deposits of the paleo-lakes of Monte Amiata. For these reasons, they represent geological materials with a fundamental cultural value
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