The Role of Anisotropy in Distinguishing Domination of Néel or Brownian Relaxation Contribution to Magnetic Inductive Heating: Orientations for Biomedical Applications

Magnetic inductive heating (MIH) has been a topic of great interest because of its potential applications, especially in biomedicine. In this paper, the parameters characteristic for magnetic inductive heating power including maximum specific loss power (SLPmax), optimal nanoparticle diameter (Dc) and its width (ΔDc) are considered as being dependent on magnetic nanoparticle anisotropy (K). The calculated results suggest 3 different Néel-domination (N), overlapped Néel/Brownian (NB), and Brownian-domination (B) regions. The transition from NB- to B-region changes abruptly around critical anisotropy Kc. For magnetic nanoparticles with low K (K Kc) are opposite. The decreases of the SLPmax when increasing polydispersity and viscosity are characterized by different rates of d(SLPmax)/dσ and d(SLPmax)/dη depending on each domination region. The critical anisotropy Kc varies with the frequency of an alternating magnetic field. A possibility to improve heating power via increasing anisotropy is analyzed and deduced for Fe3O4 magnetic nanoparticles. For MIH application, the monodispersity requirement for magnetic nanoparticles in the B-region is less stringent, while materials in the N- and/or NB-regions are much more favorable in high viscous media. Experimental results on viscosity dependence of SLP for CoFe2O4 and MnFe2O4 ferrofluids are in good agreement with the calculations. These results indicated that magnetic nanoparticles in the N- and/or NB-regions are in general better for application in elevated viscosity media

Risk factors associated with mechanical ventilation, autonomic nervous dysfunction and physical outcome in Vietnamese adults with tetanus.

BACKGROUND: Tetanus remains common in many low- and middle-income countries, but as critical care services improve, mortality from tetanus is improving. Nevertheless, patients develop severe syndromes associated with autonomic nervous system disturbance (ANSD) and the requirement for mechanical ventilation (MV). Understanding factors associated with worse outcome in such settings is important to direct interventions. In this study, we investigate risk factors for disease severity and long-term physical outcome in adults with tetanus admitted to a Vietnamese intensive care unit. METHODS: Clinical and demographic variables were collected prospectively from 180 adults with tetanus. Physical function component scores (PCS), calculated from Short Form Health Survey (SF-36), were assessed in 79 patients at hospital discharge, 3 and 6 months post discharge. RESULTS: Age, temperature, heart rate, lower peripheral oxygen saturation (SpO2) and shorter time from first symptom to admission were associated with MV (OR 1.03 [ 95% confidence interval (CI) 1.00, 1.05], p = 0.04; OR 2.10 [95% CI 1.03, 4.60], p = 0.04; OR 1.04 [ 95% CI 1.01, 1.07], p = 0.02); OR 0.80 [95% CI 0.66, 0.94], p = 0.02 and OR 0.65 [95% CI 0.52, 0.79, p < 0.001, respectively). Heart rate, SpO2 and time from first symptom to admission were associated with ANSD (OR 1.03 [95% CI 1.01, 1.06], p < 0.01; OR 0.95 [95% CI 0.9, 1.00], p = 0.04 and OR 0.64 [95% CI 0.48, 0.80], p < 0.01, respectively). Median [interquartile range] PCS at hospital discharge, 3 and 6 months were 32.37 [24.95-41.57, 53.0 [41.6-56.3] and 54.8 [51.6-57.3], respectively. Age, female sex, admission systolic blood pressure, admission SpO2, MV, ANSD, midazolam requirement, hospital-acquired infection, pressure ulcer and duration of ICU and hospital stay were associated with reduced 0.25 quantile PCS at 6 months after hospital discharge. CONCLUSIONS: MV and ANSD may be suitable endpoints for future research. Risk factors for reduced physical function at 3 months and 6 months post discharge suggest that modifiable features during hospital management are important determinants of long-term outcome

Numerical Hermitian Yang-Mills Connections and Kahler Cone Substructure

We further develop the numerical algorithm for computing the gauge connection of slope-stable holomorphic vector bundles on Calabi-Yau manifolds. In particular, recent work on the generalized Donaldson algorithm is extended to bundles with Kahler cone substructure on manifolds with h^{1,1}>1. Since the computation depends only on a one-dimensional ray in the Kahler moduli space, it can probe slope-stability regardless of the size of h^{1,1}. Suitably normalized error measures are introduced to quantitatively compare results for different directions in Kahler moduli space. A significantly improved numerical integration procedure based on adaptive refinements is described and implemented. Finally, an efficient numerical check is proposed for determining whether or not a vector bundle is slope-stable without computing its full connection.Comment: 38 pages, 10 figure

New convolutions for quadratic-phase Fourier integral operators and their applications

We obtain new convolutions for quadratic-phase Fourier integral operators (which include, as subcases, e.g., the fractional Fourier transform and the linear canonical transform). The structure of these convolutions is based on properties of the mentioned integral operators and takes profit of weight-functions associated with some amplitude and Gaussian functions. Therefore, the fundamental properties of that quadratic-phase Fourier integral operators are also studied (including a Riemann-Lebesgue type lemma, invertibility results, a Plancherel type theorem and a Parseval type identity). As applications, we obtain new Young type inequalities, the asymptotic behaviour of some oscillatory integrals, and the solvability of convolution integral equations

Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998–2009

Dengue is the most common vector-borne viral disease of humans, causing an estimated 50 million cases per year. The number of countries affected by dengue has increased dramatically in the last 50 years and dengue is now a major public health problem in large parts of the tropical and subtropical world. It is of considerable importance to understand the factors that determine how dengue becomes newly established in areas where the risk of dengue was previously small. Hanoi in North Vietnam is a large city where dengue appears to be emerging. We analyzed 12 years of dengue surveillance data in order to characterize the temporal and spatial epidemiology of dengue in Hanoi and to establish if dengue incidence has been increasing. After excluding the two major outbreak years of 1998 and 2009 and correcting for changes in population age structure over time, we found there was a significant annual increase in the incidence of notified dengue cases over the period 1999–2008. Dengue cases were concentrated in young adults in the highly urban central areas of Hanoi. This study indicates that dengue transmission is increasing in Hanoi and provides a platform for further studies of the underlying drivers of this emergence

Relative K-stability for Kähler manifolds

We study the existence of extremal Kähler metrics on Kähler manifolds. After introducing a notion of relative K-stability for Kahler manifolds, we prove that Kähler manifolds admitting extremal Kähler metrics are relatively K-stable. Along the way, we prove a general Lp lower bound on the Calabi functional involving test configurations and their associated numerical invariants, answering a question of Donaldson. When the Kähler manifold is projective, our definition of relative K-stability is stronger than the usual definition given by Székelyhidi. In particular our result strengthens the known results in the projective case (even for constant scalar curvature Kähler metrics), and rules out a well known counterexample to the "naïve" version of the Yau-Tian-Donaldson conjecture in this setting