1,862 research outputs found
An analytic expression for the electronic correlation term of the kinetic functional
We propose an analytic formula for the non-local Fisher information
functional, or electronic kinetic correlation term, appearing in the expression
of the kinetic density functional. Such an explicit formula is constructed on
the basis of well-founded physical arguments and a rigorous mathematical
prescription
To Sketch-a-Scratch
A surface can be harsh and raspy, or smooth and silky, and everything in between. We are used to sense these features with our fingertips as well as with our eyes and ears: the exploration of a surface is a multisensory experience. Tools, too, are often employed in the interaction with surfaces, since they augment our manipulation capabilities. “Sketch-a-Scratch” is a tool for the multisensory exploration and sketching of surface textures. The user’s actions drive a physical sound model of real materials’ response to interactions such as scraping, rubbing or rolling. Moreover, different input signals can be converted into 2D visual surface profiles, thus enabling to experience them visually, aurally and haptically
Pre-treatment high-sensitivity troponin T for the short-term prediction of cardiac outcomes in patients on immune checkpoint inhibitors
Background: Immune checkpoint inhibitors (ICIs) are an emerging option for several advanced metastatic cancers, but may have cardiotoxic effects. The prognostic value of high-sensitivity troponin T (hs-TnT) before treatment start has never been investigated. Materials and methods: Thirty consecutive patients underwent measurement of hs-TnT before starting ICI therapy (pembrolizumab, 23%; nivolumab, 12%; atezolizumab, 6%; durvalumab, 5%). The primary endpoint of cardiovascular death, stroke or transient ischaemic attack, pulmonary embolism and new-onset heart failure, and the secondary endpoint of progression of cardiac involvement according to the CARDIOTOX classification were evaluated after 3 months from the first cycle. Results: Patients (median age 68 years, 77% men, 13% with coronary artery disease, 90% current or former smokers, 67% overweight or obese and 43% hypertensive) had a median hs-TnT of 12 ng/L (interquartile interval 8-23). The primary endpoint occurred only in patients with hs-TnT ≥ 14 ng/L at baseline. Therefore, only patients who had hs-TnT ≥ 14 ng/L before the first cycle died had a stroke/TIA or new-onset HF. Furthermore, nine out of 13 patients with the secondary endpoint (progression of cardiac disease) had hs-TnT ≥ 14 ng/L before the first cycle (P =.012). AUC values were 0.909 for the primary endpoint and 0.757 for the secondary endpoint. The best cut-off was 14 ng/L for both the primary (100% sensitivity, 73% specificity) and secondary endpoints (sensitivity 75%, specificity 77%). Conclusions: In patients on ICIs, baseline hs-TnT predicts a composite cardiovascular endpoint and the progression of cardiac involvement at 3 months, with 14 ng/L as the best cut-off
On the upper bound of the electronic kinetic energy in terms of density functionals
We propose a simple density functional expression for the upper bound of the
kinetic energy for electronic systems. Such a functional is valid in the limit
of slowly varying density, its validity outside this regime is discussed by
making a comparison with upper bounds obtained in previous work. The advantages
of the functional proposed for applications to realistic systems is briefly
discussed.Comment: 10 pages, no figure
Do radiolucent lines and stress shielding of the humeral shaft really matter in shoulder arthroplasty?
The purpose of this study is to evaluate at a mid-term follow up, the radiological survival of an
uncemented humeral stem in shoulder arthroplasty. One hundred and twenty-six replacements
including hemi (HA), total (TSA) and reverse (RSA) implanted from 1999 to 2008 were reviewed at
a mean follow up of 7.2 years (48-144 months). The same uncemented triconical stem (SMR, Lima
Corporate) was implanted. There were: 23 HSA, 43 TSA, 60 RSA. An independent observer evaluated
all the patients with Constant Score. A radiologic analysis by an expert radiologist and an orthopaedic
surgeon was performed: humeral component-bone interface was divided in seven zones. They judged
a mobilisation if a migration or tilt of the humeral implant or if≥ 2 mm radiolucent line in at least
three zones was present. Chi-squared test, Fisher test and analysis of variance were performed and
a p<0.05 was considered statistically significant. No major radiological signs of loosening and no tilt
or migration of the humeral component were found. Only 23 (18.2%) patients had no RL around the
humeral implant. In the remaining 103 (81.7%) implants: 96 (76.1%) presented RL less than 2 mm,
particularly 75 (59.5%) in less than 3 zones and 21 (16.6%) in more than 3 zones. Of the remaining 7
(5.5%) implants the presence of RL of 2 mm or greater in only one zone was seen. Apart from sepsis
no revision was performed for humeral component loosening. Although a high rate of RL, uncemented
humeral stem has an excellent survivorship at a mid-term follow up. Relationship between presence,
position and depth of RL and internal stress shielding is commonly observed but does not appear t
A simplified procedure for the accurate frequency response identification of voltage transformers
The paper proposes a simplified and affordable procedure for instrument transformers frequency characterization for medium voltage applications. It consists of a two steps measurement procedure, where both steps involve the generation of sine waves only, so that the it can be easily performed in instrument transformers calibration laboratories without requiring additional generation features. In the first step, a 50 Hz measurement of the Voltage Instrument Transformer ratio error at rated voltage is performed. The second step consists of a frequency sweep performed at low voltage up to the first resonance. By these two data sets, an approximated but accurate frequency response can be easily obtained using a non-linear fitted model. In the paper, a commercial voltage instrument transformer for medium voltage grids is characterized by the proposed method; results are shown and validated by comparison with a reference frequency characterization performed at INRIM under rated voltage. © IMEKO TC-4 2020
Adaptive Resolution Simulation of Liquid Water
We present a multiscale simulation of liquid water where a spatially adaptive
molecular resolution procedure allows for changing on-the-fly from a
coarse-grained to an all-atom representation. We show that this approach leads
to the correct description of all essential thermodynamic and structural
properties of liquid water.Comment: 4 pages, 3 figures; changed figure
Interception of vertically approaching objects: temporal recruitment of the internal model of gravity and contribution of optical information
introduction: recent views posit that precise control of the interceptive timing can be achieved by combining on-line processing of visual information with predictions based on prior experience. Indeed, for interception of free-falling objects under gravity's effects, experimental evidence shows that time-to-contact predictions can be derived from an internal gravity representation in the vestibular cortex. however, whether the internal gravity model is fully engaged at the target motion outset or reinforced by visual motion processing at later stages of motion is not yet clear. moreover, there is no conclusive evidence about the relative contribution of internalized gravity and optical information in determining the time-to-contact estimates.methods: we sought to gain insight on this issue by asking 32 participants to intercept free falling objects approaching directly from above in virtual reality. object motion had durations comprised between 800 and 1100 ms and it could be either congruent with gravity (1 g accelerated motion) or not (constant velocity or -1 g decelerated motion). we analyzed accuracy and precision of the interceptive responses, and fitted them to bayesian regression models, which included predictors related to the recruitment of a priori gravity information at different times during the target motion, as well as based on available optical information.results: consistent with the use of internalized gravity information, interception accuracy and precision were significantly higher with 1 g motion. moreover, bayesian regression indicated that interceptive responses were predicted very closely by assuming engagement of the gravity prior 450 ms after the motion onset, and that adding a predictor related to on-line processing of optical information improved only slightly the model predictive power. discussion: thus, engagement of a priori gravity information depended critically on the processing of the first 450 ms of visual motion information, exerting a predominant influence on the interceptive timing, compared to continuously available optical information. finally, these results may support a parallel processing scheme for the control of interceptive timing
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