12,939 research outputs found
I brevetti delle Universit\ue0 regionali e la rete degli accademici inventori
Come differiscono le reti di collaborazione generate dai brevetti quando si considerino congiuntamente i brevetti Univerity Owned e quelli Unvieristy Invented? Le diverse configurazioni che si generano sono influenzate delle strategie delle singole Universit\ue0?\u2019 E qual \ue8 la loro importanza come canali di trasferimento della conoscenza nel territorio pi\uf9 prossimo? .Lo studio contribuisce all\u2019esame di questi problemi attraverso l\u2019analisi del caso studio delle Universit\ue0 di Trieste e di Udine. I risultati della Social Network Analysis evidenziano significative differenze tra le due Universit\ue0: in particolare. nel caso di Trieste, le reti generate dai due tipi di brevetti mostrano una sovrapposizione nettamente pi\uf9 marcata. Il legame con il territorio locale appare, invece, sempre piuttosto debole sia per i brevetti Univerity Owned che per quelli Univerity Invented., Sotto il profilo metodologico, l\u2019analisi micro, condotta a livello delle sottoreti e di regioni specifiche della rete, si dimostra quella pi\uf9 fruttuosa
Relativistic tunneling through opaque barriers
We propose an analytical study of relativistic tunneling through opaque
barriers. We obtain a closed formula for the phase time. This formula is in
excellent agreement with the numerical simulations and corrects the standard
formula obtained by the stationary phase method. An important result is found
when the upper limit of the incoming energy distribution coincides with the
upper limit of the tunneling zone. In this case, the phase time is proportional
to the barrier width.Comment: 11 pages, 3 figure
Implant survival and success rates in patients with risk factors: results from a long-term retrospective study with a 10 to 18 years follow-up
OBJECTIVE:
Risk factors for implant therapy are represented by all general and local conditions that through various mechanisms can increase either short-term and long-term failure risk. The aim of this study is to assess the implant survival and implant success rates with single and multiple risk factors.
PATIENTS AND METHODS:
To address the research purpose, a retrospective cohort study was designed and implemented, including a sample of 225 patients with a total of 871 implants placed. The following risk factors were considered: smoking, bruxism, bone augmentation procedures and the presence of load risk (implants with crown/implant relation > 0.8; angulation > 25°; presence of cantilever). Follow-up ranged from 10 years to 18 years (average follow-up 13.6 years). Failures were subdivided into short-term failures, before the prosthetic phase, and long-term failures, after definitive prosthesis. The success criteria published by Albrektsson and Zarb were adopted. A Cox proportional hazard regression model was used to calculate hazard ratio, with a statistically significant p-value <0.05.
RESULTS:
Out of the 871 implants placed, 138 did not meet the success criteria, (success rate 84.16%), sixty (43.47%) were classified as "early failure" and seventy-eight as "late failure" (56.53%). A total of 70 dental implants were removed, with a survival rate of 91.96%.
CONCLUSIONS:
The presence of a single risk factor does not imply a marked increase of failure risk. Among the analyzed factors, the one that proved to be the most dangerous was bruxism, even when presented as the only risk factor. Bruxism with load risk proved to be the most dangerous association (success rate 69.23%) and could be included among the absolute contraindications for implant treatment
Long-Range Effects in Layered Spin Structures
We study theoretically layered spin systems where long-range dipolar
interactions play a relevant role. By choosing a specific sample shape, we are
able to reduce the complex Hamiltonian of the system to that of a much simpler
coupled rotator model with short-range and mean-field interactions. This latter
model has been studied in the past because of its interesting dynamical and
statistical properties related to exotic features of long-range interactions.
It is suggested that experiments could be conducted such that within a specific
temperature range the presence of long-range interactions crucially affect the
behavior of the system
Chronic bacterial prostatitis: efficacy of short-lasting antibiotic therapy with prulifloxacin (Unidrox®) in association with saw palmetto extract, lactobacillus sporogens and arbutin (Lactorepens®)
Bacterial prostatitis (BP) is a common condition accounting responsible for about 5-10% of all prostatitis cases; chronic bacterial prostatitis (CBP) classified as type II, are less common but is a condition that significantly hampers the quality of life, (QoL) because not only is it a physical condition but also a psychological distress. Commonly patients are treated with antibiotics alone, and in particular fluoroquinolones are suggested by the European Urology guidelines. This approach, although recommended, may not be enough. Thus, a multimodal approach to the prolonged antibiotic therapy may be helpful.210 patients affected by chronic bacterial prostatitis were enrolled in the study. All patients were positive to Meares-Stamey test and symptoms duration was > 3 months. The purpose of the study was to evaluate the efficacy of a long lasting therapy with a fluoroquinolone in association with a nutraceutical supplement (prulifloxacin 600 mg for 21 days and an association of Serenoa repens 320 mg, Lactobacillus Sporogens 200 mg, Arbutin 100 mg for 30 days). Patients were randomized in two groups (A and B) receiving respectively antibiotic alone and an association of antibiotic plus supplement.Biological recurrence at 2 months in Group A was observed in 21 patients (27.6%) and in Group B in 6 patients (7.8%). Uropathogens found at the first follow-up were for the majority Gram - (E. coli and Enterobacter spp.). A statistically significant difference was found at the time of the follow-up between Group A and B in the NIH-CPSI questionnaire score, symptoms evidence and serum PSA.Broad band, short-lasting antibiotic therapy in association with a nutritional supplement (serenoa repens, lactobacillus sporogens and arbutin) show better control and recurrence rate on patients affected by chronic bacterial prostatitits in comparison with antibiotic treatment alone.NCT02130713Date of trial Registration: 30/04/2014
A randomized clinical trial about presence of pathogenic microflora and risk of peri-implantitis: comparison of two different types of implant-abutment connections
OBJECTIVE:
The aim of this in vivo study was to evaluate two different types of implant-abutment connections: screwed connection and cemented connection, analyzing peri-implant bacteria microflora as well as other clinical parameters.
PATIENTS AND METHODS:
Twenty implants were selected, inserted in 20 patients, 10 with a screwed implant-abutment connection (Group 1) and 10 with a cemented implant-abutment connection (Group 2). The peri-implant microflora was collected, after at least 360 days from the prosthetic rehabilitation, using paper points inserted in peri-implant sulcus for 30 s. Polymerase chain reaction (PCR) Real-time analyzed the presence of 9 bacteria periodontal-pathogens and Candida albicans.
RESULTS:
Our findings showed that bacteria colonized all Groups analyzed, the average bacterial count was 3.7 E +08 (±1.19) in Group 1, compared to 2.1 E +08 (±0.16) in Group 2; no statistically significant differences were observed (p>0.0.5). In Group 1, however, bacterial colonization of peri-implant sulci was over the pathogenic threshold for 5 bacteria, indicating a high-risk of peri-implantitis. Also in Group 2, results showed a microflora composed by all bacteria analyzed but, in this case, bacterial colonization of peri-implant sulci was over the pathogenic threshold for only 1 bacterium, indicating a lower risk of peri-implantitis. Moreover, clinical parameters (PPD > 3 mm and m SBI > 0) confirmed a greater risk of peri-implantitis in Group 1 compared to Group 2 (p<0.05).
CONCLUSIONS:
We concluded that, also after only 360 days, implants with screwed connection showed a higher risk of peri-implantitis that implants with cemented connection
Quaternionic potentials in non-relativistic quantum mechanics
We discuss the Schrodinger equation in presence of quaternionic potentials.
The study is performed analytically as long as it proves possible, when not, we
resort to numerical calculations. The results obtained could be useful to
investigate an underlying quaternionic quantum dynamics in particle physics.
Experimental tests and proposals to observe quaternionic quantum effects by
neutron interferometry are briefly reviewed.Comment: 21 pages, 16 figures (ps), AMS-Te
Soft Concurrent Constraint Programming
Soft constraints extend classical constraints to represent multiple
consistency levels, and thus provide a way to express preferences, fuzziness,
and uncertainty. While there are many soft constraint solving formalisms, even
distributed ones, by now there seems to be no concurrent programming framework
where soft constraints can be handled. In this paper we show how the classical
concurrent constraint (cc) programming framework can work with soft
constraints, and we also propose an extension of cc languages which can use
soft constraints to prune and direct the search for a solution. We believe that
this new programming paradigm, called soft cc (scc), can be also very useful in
many web-related scenarios. In fact, the language level allows web agents to
express their interaction and negotiation protocols, and also to post their
requests in terms of preferences, and the underlying soft constraint solver can
find an agreement among the agents even if their requests are incompatible.Comment: 25 pages, 4 figures, submitted to the ACM Transactions on
Computational Logic (TOCL), zipped file
Reversible and Irreversible Spacetime Thermodynamics for General Brans-Dicke Theories
We derive the equations of motion for Palatini F(R) gravity by applying an
entropy balance law T dS= \delta Q+\delta N to the local Rindler wedge that can
be constructed at each point of spacetime. Unlike previous results for metric
F(R), there is no bulk viscosity term in the irreversible flux \delta N. Both
theories are equivalent to particular cases of Brans-Dicke scalar-tensor
gravity. We show that the thermodynamical approach can be used ab initio also
for this class of gravitational theories and it is able to provide both the
metric and scalar equations of motion. In this case, the presence of an
additional scalar degree of freedom and the requirement for it to be dynamical
naturally imply a separate contribution from the scalar field to the heat flux
\delta Q. Therefore, the gravitational flux previously associated to a bulk
viscosity term in metric F(R) turns out to be actually part of the reversible
thermodynamics. Hence we conjecture that only the shear viscosity associated
with Hartle-Hawking dissipation should be associated with irreversible
thermodynamics.Comment: 12 pages, 1 figure; v2: minor editing to clarify Section III, fixed
typos; v3: fixed typo
Anomalous thermodynamics at the micro-scale
Particle motion at the micro-scale is an incessant tug-of-war between thermal
fluctuations and applied forces on one side, and the strong resistance exerted
by fluid viscosity on the other. Friction is so strong that completely
neglecting inertia - the overdamped approximation - gives an excellent
effective description of the actual particle mechanics. In sharp contrast with
this result, here we show that the overdamped approximation dramatically fails
when thermodynamic quantities such as the entropy production in the environment
is considered, in presence of temperature gradients. In the limit of
vanishingly small, yet finite inertia, we find that the entropy production is
dominated by a contribution that is anomalous, i.e. has no counterpart in the
overdamped approximation. This phenomenon, that we call entropic anomaly, is
due to a symmetry-breaking that occurs when moving to the small, finite inertia
limit. Strong production of anomalous entropy is traced back to intense sweeps
down the temperature gradient.Comment: 4 pages, 1 figure, supplementary information uploaded as a separate
pdf file (see other formats link
- …
