Abstract This paper investigates the separation property in binary phase-segregation processes modelled by Cahn-Hilliard type equations with constant mobility, singular entropy densities and ...different particle interactions. Under general assumptions on the entropy potential, we prove the strict separation property in both two and three-space dimensions. Namely, in 2D, we notably extend the minimal assumptions on the potential adopted so far in the literature, by only requiring a mild growth condition of its first derivative near the singular points $\pm 1$ , without any pointwise additional assumption on its second derivative. For all cases, we provide a compact proof using De Giorgi’s iterations. In 3D, we also extend the validity of the asymptotic strict separation property to the case of fractional Cahn-Hilliard equation, as well as show the validity of the separation when the initial datum is close to an ‘energy minimizer’. Our framework offers insights into statistical factors like particle interactions, entropy choices and correlations governing separation, with broad applicability.
Achieving good quality Ohmic contacts to van der Waals materials is a challenge, since at the interface between metal and van der Waals material different conditions can occur, ranging from the ...presence of a large energy barrier between the two materials to the metallization of the layered material below the contacts. In black phosphorus (bP), a further challenge is its high reactivity to oxygen and moisture, since the presence of uncontrolled oxidation can substantially change the behavior of the contacts. Here we study three of the most commonly used metals as contacts to bP, chromium, titanium, and nickel, and investigate their influence on contact resistance against the variability between different flakes and different samples. We investigate the gate dependence of the current-voltage characteristics of field-effect transistors fabricated with these metals on bP, observing good linearity in the accumulation regime for all metals investigated. Using the transfer length method, from an analysis of ten devices, both at room temperature and at low temperature, Ni results to provide the lowest contact resistance to bP and minimum scattering between different devices. Moreover, we observe that our best devices approach the quantum limit for contact resistance both for Ni and for Ti contacts.
Essentials
Lower limb ultrasonography (CUS) could be useful in suspected pulmonary embolism (PE).
We performed a metaanalysis on the diagnostic characteristics of CUS in suspected PE.
With a ...sensitivity of 41%, proximal CUS would be positive in one of every 7.3 patients.
Complete CUS has a higher sensitivity but specificity for PE is too low to use it in suspected PE.
Summary
Background
Diagnosis of pulmonary embolism (PE) is commonly based on D‐dimer measurement and computed tomography (CT) angiography. Lower limb vein compression ultrasonography (CUS) for diagnosing deep vein thrombosis may be of interest in patients with suspected PE.
Objectives
We aimed to summarize the data on the diagnostic characteristics of CUS in suspected PE patients.
Patients/Methods
We conducted a literature review by using PUBMED and EMBASE and included 15 prospective studies in which CUS was performed in consecutive patients with suspected PE.
Results
Of the 6991 included patients, 2001 (30%) had pulmonary embolism. Eight of the 15 studies included only outpatients, two included hospitalized patients and five involved both in‐ and outpatients. In 13 studies, only proximal CUS was performed. Two studies analyzed the added value of distal CUS including the calf veins (whole‐leg CUS). Pooled estimate of proximal CUS sensitivity was 41% (95% confidence interval CI, 36–46%) with strong heterogeneity (I square, 79%). Specificity of proximal CUS was 96% (95% CI, 94–98%). The overall positive likelihood ratio for proximal CUS was 11.9 (95% CI, 7.1–19.8), whereas the overall negative likelihood ratio was 0.6 (95% CI, 0.5–0.7). The sensitivity of whole‐leg CUS was 79% (95% CI, 24–98%) and specificity was 84% (95% CI, 76–90%).
Conclusions
Proximal CUS has low sensitivity and cannot be used to rule out PE. Nevertheless, its high specificity allows confirming PE, which may be useful in patients with contraindications to CT angiography. Whole‐leg CUS has a higher sensitivity but low specificity for PE and can therefore not be recommended.
Background: Risk factors for post‐thrombotic syndrome (PTS) remain poorly understood.
Objectives: In this multinational multicenter study, we evaluated whether subtherapeutic warfarin ...anticoagulation was associated with the development of PTS.
Methods: Patients with a first unprovoked deep venous thrombosis (DVT) received standard anticoagulation for 5–7 months and were then assessed for PTS. The time in the therapeutic range was calculated from the international normalized ratio (INR) data. An INR below 2, more than 20% of the time, was considered as subtherapeutic anticoagulation.
Results: Of the 349 patients enrolled, 97 (28%) developed PTS. The overall frequency of PTS in patients with subtherapeutic anticoagulation was 33.5%, compared with 21.6% in those with an INR below two for ≤ 20% of the time (P = 0.01). During the first 3 months of therapy, the odds ratio (OR) for developing PTS if a patient had subtherapeutic anticoagulation was 1.78 (95% confidence interval CI 1.10–2.87). After adjusting for confounding variables, the OR was 1.84 (95% CI 1.13–3.01). Corresponding ORs for the full period of anticoagulation were 1.83 (95% CI 1.14–3.00) crude and 1.88 (95% CI 1.15–3.07) adjusted.
Conclusion: Subtherapeutic warfarin anticoagulation after a first unprovoked DVT was significantly associated with the development of PTS.
In a recent book, the authors of this paper have studied the classical heat and Laplace equations with real time variable and complex spatial variable by the semigroup theory methods, under the ...hypothesis that the boundary function belongs to the space of analytic functions in the open unit disk and continuous in the closed unit disk, endowed with the uniform norm. The purpose of the present note is to show that the semigroup theory methods works for these evolution equations of complex spatial variables, under the hypothesis that the boundary function belongs to the much larger weighted Bergman space $B_{\alpha }^p(D)$ with $1\leq p<+\infty $, endowed with a $L^p$-norm. Also, the case of several complex variables is considered. The proofs require some new changes appealing to Jensen's inequality, Fubini's theorem for integrals and the $L^p$-integral modulus of continuity. The results obtained can be considered as complex analogues of those for the classical heat and Laplace equations in $L^p(\mathbb{R})$ spaces.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
An important challenge for conserving and managing marine ecosystems is to advance our understanding of how multiple human stressors, environmental factors and marine resources interact and influence ...each other. The ecosystems of the Israeli Mediterranean coast have undergone significant ecological changes in recent decades, caused primarily by the introduction of alien species, fishing and the warming of the waters. Here we used a food-web model representing the continental shelf of the Israeli Mediterranean coast to explore the historical dynamics of the area considering the combined effect of alien species, fishing activities and changes in sea surface temperature and primary productivity. The food-web model was fitted to available time series of data from the early 1990s to 2010 using the temporal dynamic module of the Ecopath with Ecosim modeling approach. An important challenge was to model the numerous alien species inhabiting the Eastern Mediterranean Sea, one of the most invaded marine ecosystems of the world. Historical model simulations satisfactorily matched observed data, especially regarding alien groups. However, lack of data from the pelagic environment limited our ability to compare model output with historical observations. Trophic interactions, climate change and fishing were important factors explaining the historical dynamics of the ecosystem, which showed a degradation pattern over time. Results also highlighted an increasing proportion of alien species in biomass and catch over time, with important effects on the food web. This study represents an important step forward in understanding the changes that are occurring in the Israeli continental shelf ecosystem and the Levantine Sea.
Background: The revised Geneva score, a standardized clinical decision rule in the diagnosis of pulmonary embolism (PE), was recently developed. The Wells clinical decision is widely used but lacks ...full standardization, as it includes subjective clinician’s judgement. We have compared the performance of the revised Geneva score with the Wells rule, and their usefulness for ruling out PE in combination with D‐dimer measurement.
Methods: In 300 consecutive patients, the clinical probability of PE was assessed prospectively by the Wells rule and retrospectively using the revised Geneva score. Patients comprised a random sample from a single center, participating in a large prospective multicenter diagnostic study. The predictive accuracy of both scores was compared by area under the curve (AUC) of receiver operating characteristic (ROC) curves.
Results: The overall prevalence of PE was 16%. The prevalence of PE in the low‐probability, intermediate‐probability and high‐probability categories as classified by the revised Geneva score was similar to that of the original derivation set. The performance of the revised Geneva score as measured by the AUC in a ROC analysis did not differ statistically from the Wells rule. After 3 months of follow‐up, no patient classified into the low or intermediate clinical probability category by the revised Geneva score and a normal D‐dimer result was subsequently diagnosed with acute venous thromboembolism.
Conclusions: This study suggests that the performance of the revised Geneva score is equivalent to that of the Wells rule. In addition, it seems safe to exclude PE in patients by the combination of a low or intermediate clinical probability by the revised Geneva score and a normal D‐dimer level. Prospective clinical outcome studies are needed to confirm this latter finding.
See also Watson HG. RVO – Real value obscure. This issue, pp 1116–8; Le Gal G, Carrier M, Kovacs MJ, Betancourt MT, Kahn SR, Wells PS, Anderson DA, Chagnon I, Solymoss S, Crowther M, Righini M, ...Delluc A, White RH, Vickars L, Rodger M. Residual vein obstruction as a predictor for recurrent thromboembolic events after a first unprovoked episode: data from the REVERSE cohort study. This issue, pp 1126–32.
Summary. Background: Residual vein obstruction (RVO) detected on compression ultrasonography of the leg after a few months of anticoagulation therapy might be able to identify patients with deep vein thrombosis (DVT) at high risk of having a recurrent venous thromboembolism (VTE). Aim: To determine whether RVO is associated with an increased risk of recurrent events in patients with DVT. Patients and Methods: A systematic literature search strategy was conducted using MEDLINE, EMBASE, and the Cochrane Register of Controlled Trials. We selected 14 articles (nine prospective cohort studies and five randomized controlled trials) that included patients with DVT who had an assessment for RVO with the use of compression ultrasonography. Two reviewers independently extracted data onto standardized forms. Results: Overall, the presence of RVO was not associated with an increased risk of recurrent VTE (odds ratio OR 1.24, 95% confidence interval CI 0.9–1.7) in patients with unprovoked DVT who stopped oral anticoagulation therapy at the time of RVO assessment. However, RVO was significantly associated with recurrent VTE in patients with any (unprovoked or provoked) DVT (OR 1.5, 95% CI 1.1–2.0). Conclusions: RVO was associated with a modestly increased risk of recurrent VTE in patients with DVT (unprovoked and provoked). However, RVO did not seem to be a predictor of recurrent VTE in patients with unprovoked DVT following anticoagulation discontinuation. Further prospective studies are needed to assess the role of RVO in patients with unprovoked DVT.
PDF
