Laboratory capability for molecular detection and confirmation of novel coronavirus in Europe, November 2012

A rapid survey by the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) Regional Office for Europe ascertained the availability of national reference laboratory testing for a recently detected novel coronavirus as of 28 November 2012. Screening by internal quality controlled upE-RT-PCR assay was available in 23/46 of responding countries in the WHO European Region, of which 19/30 in European Union (EU) and European Economic Area (EEA) countries. Confirmation of positive screened samples by either ORF1b - RT-PCR, or other target RT-PCR assays with sequence analysis or whole-genome sequence analysis was available in 22/46 responding countries of which 18/30 in EU/EEA countries.

Artefacts in CBCT: a review

Artefacts are common in today's cone beam CT (CBCT). They are induced by discrepancies between the mathematical modelling and the actual physical imaging process. Since artefacts may interfere with the diagnostic process performed on CBCT data sets, every user should be aware of their presence. This article aims to discuss the most prominent artefacts identified in the scientific literature and review the existing knowledge on these artefacts. We also briefly review the basic three-dimensional (3D) reconstruction concept applied by today's CBCT scanners, as all artefacts are more or less directly related to it.

Fully Coupled 3-D Modelling of Ferroelectric Polycrystalline Material Behavior

A thermodynamically consistent phenomenological model for the material behavior of polycrystalline ferroelectric ceramics is presented. The internal state of the material is described by two internal state variables. The first one is a second-order texture tensor, determining a simple orientation distribution function (ODF) for the axes of the crystal unit cells. The second is the vector of relative irreversible polarization. The irreversible strains are derived from the ODF by volume averaging. The polarization saturation states are calculated by summing up the possible contributions of all cells to the overall polarization. An invariant formulation of the piezoelectric law is applied. Analogous to the thermodynamical framework of rate-independent plasticity, driving forces and evolution laws for the internal state variables are established. Saturation and coupling of the switching behavior are governed by energy barrier functions introduced in the electric enthalpy function. Numerical examples illustrate the models capabilities.

Permutationally invariant quantum tomography

We present a scalable method for the tomography of large multiqubit quantum registers. It acquires information about the permutationally invariant part of the density operator, which is a good approximation to the true state in many relevant cases. Our method gives the best measurement strategy to minimize the experimental effort as well as the uncertainties of the reconstructed density matrix. We apply our method to the experimental tomography of a photonic four-qubit symmetric Dicke state.

Supersonic quantum communication

When locally exciting a quantum lattice model, the excitation will propagate through the lattice. This effect is responsible for a wealth of nonequilibrium phenomena, and has been exploited to transmit quantum information. It is a commonly expressed belief that for local Hamiltonians, any such propagation happens at a finite "speed of sound". Indeed, the Lieb-Robinson theorem states that in spin models, all effects caused by a perturbation are essentially limited to a causal cone. We show that for meaningful translationally invariant bosonic models with nearest-neighbor interactions (addressing the challenging aspect of an experimental realization) this belief is incorrect: We prove that one can encounter accelerating excitations under the natural dynamics that allow for reliable transmission of information faster than any finite speed of sound. It also implies that the simulation of dynamics of strongly correlated bosonic models may be much harder than that of spin chains even in the low-energy sector.

Most quantum States are too entangled to be useful as computational resources

It is often argued that entanglement is at the root of the speedup for quantum compared to classical computation, and that one needs a sufficient amount of entanglement for this speedup to be manifest. In measurement-based quantum computing, the need for a highly entangled initial state is particularly obvious. Defying this intuition, we show that quantum states can be too entangled to be useful for the purpose of computation, in that high values of the geometric measure of entanglement preclude states from offering a universal quantum computational speedup. We prove that this phenomenon occurs for a dramatic majority of all states: the fraction of useful n-qubit pure states is less than exp(-n;{2}). This work highlights a new aspect of the role entanglement plays for quantum computational speedups.

Selective amygdalohippocampectomy: surgical outcome in children versus adults

INTRODUCTION

The objective of the study was to review our experience with selective amygdalohippocampectomy (SAH) in children and adults with intractable temporal lobe epilepsy.

METHODS

A retrospective case series was used in the setting of a tertiary care hospital which provides epilepsy care to both children and adults. All patients underwent a selective amygdalohippocampectomy procedure and had at least one year of follow-up. Adults and children were divided into two groups and the data was compared between children and adults.

RESULTS

Twenty three patients, 9 children and 14 adults were studied. Age of surgery varied from 6 to 58 years. Surgical outcome was variable between the two groups. Amongst the children, three patients (33%) were seizure-free (Engel Class I), two patients (22%) had rare seizures (Engel Class II), one patient (11%) had a worthwhile decrease in seizures (Engel class III) and three patients (32%) had refractory seizures that required re-operation with an anterior temporal lobectomy. This differed from the adults, who all had a good outcome. Ten patients (71%) were seizure-free (Engel Class I) and the remainder (29%) had rare seizures (Engel Class II).

CONCLUSION

Selective amygdalohippocampectomy can lead to excellent seizure surgical outcome in adults with refractory temporal lobe epilepsy. However, preliminary results show less favorable results in children. The difference is probably related to the different pathology between the two groups. Anterior temporal lobe resection may prove to be a more successful operation than SAH in children with intractable temporal lobe epilepsy.

Novel schemes for measurement-based quantum computation

We establish a framework which allows one to construct novel schemes for measurement-based quantum computation. The technique develops tools from many-body physics-based on finitely correlated or projected entangled pair states-to go beyond the cluster-state based one-way computer. We identify resource states radically different from the cluster state, in that they exhibit nonvanishing correlations, can be prepared using nonmaximally entangling gates, or have very different local entanglement properties. In the computational models, randomness is compensated in a different manner. It is shown that there exist resource states which are locally arbitrarily close to a pure state. We comment on the possibility of tailoring computational models to specific physical systems.

Simulation of discontinuous damage incorporating residual stresses in circumferentially overstretched atherosclerotic arteries

When a balloon-angioplasty is performed, the arterial wall is overstretched and thereby damaged, which leads to a stiffness reduction in the arterial layers. An anisotropic damage model able to reflect the main damage mechanisms in overstretched arterial walls is used in combination with a polyconvex hyperelastic stored energy function. Furthermore, a method for the incorporation of residual stresses present in the wall of unloaded configurations is applied. The energy describes the anisotropic hyperelastic behavior of arteries under physiological conditions. Due to the assumption that the rupture of cross-bridges between collageneous micro-fibrils is responsible for the damage inside arterial walls, the damage function is applied to that part of the energy only which is associated to the fiber elasticity. For the incorporation of the residual stresses into the simulation, we apply a method which consists of two simulation steps. Finally, a numerical simulation of the overstretching of a simplified atherosclerotic artery is performed taking into account residual stresses.

Laparoscopic adrenalectomy

BACKGROUND

Soon after its introduction, laparoscopic adrenalectomy (LA) became the procedure of choice in the surgical management of most adrenal tumors. The aim of this study was to assess the outcome and learning curve of the first 100 cases operated by the same surgical team.

METHODS

Retrospective analysis of prospectively collected data of 100 consecutive LAs was performed. The parameters studied were indication for surgery, side and length of operation, intra- and postoperative complications, size of tumor, conversion to open surgery, final diagnosis, and length of stay.

RESULTS

Between 1996 and 2002, 100 LAs were performed in 90 patients. The procedures included 45 left, 35 right, and 10 bilateral resections for pheochromocytoma (29), Cushings syndrome (27), Conns syndrome (16), nonfunctioning adenoma (13), and others (5). Mean tumor size was 4.16 cm (range, 0.3-11). Overall major morbidity occurred in eight patients (9%); there was one mortality due to cerebrovascular accident in an elderly patient. Five cases (5%) were converted to open surgery. The mean length of stay for the whole group was 4.7 days (range, 2-25). In order to assess the learning curve, procedures were divided into three, equal consecutive groups (n = 33, 33, and 34). Intraoperative complications in the intermediate and late groups were significantly less compared to those in the early group (2/33, 2/34, and 7/33, respectively; (p < 0.05). Similarly, the mean operating time was significantly reduced between the early (169 min) and both intermediate (116 min) and late (127 min) groups (p < 0.005). The conversion rate was reduced between the three groups (3/33, 2/33, and 0/34), but this was not significant (p = 0.06).

CONCLUSIONS

As expected, the outcome of LA is associated with a steep learning curve. According to this study, it seems that performance of approximately 30 cases by an experienced laparoscopic surgeon is required to master the procedure.

Ginseng improves pulmonary functions and exercise capacity in patients with COPD

Ginseng is a root that has been used to treat patients with various illnesses for the last 2000 years. The purpose of this study was to evaluate the effects of Ginseng extract (G115) on Pulmonary Function Tests (PFTs), Maximum Voluntary Ventilation (MVV), Maximum Inspiratory Pressure (MIP) and Maximal Oxygen Consumption (VO2max) in patients with moderately-severe Chronic Obstructive Pulmonary Disease (COPD). Ninety-two adults were randomly divided into the experimental (n = 49, G115 100 mg bid for three months) and placebo-control (n = 43) groups. PFTs, MVV and MIP were studied before treatment and every two weeks for the 3-month-study period. Exercise test and VO2max measurements were performed before the beginning and after six weeks and three months. P lower than 0.05 was considered significant. Baseline demographics and pulmonary parameters were similar between the groups. In the experimental, but not in the control group, all parameters significantly increased above baseline and compared with the placebo group. Maximum increase, compared with baseline was FVC-32.5%, FEV1.0-27.0%, PEF-27.5%, FEF50-45.4%, FEF75-56.9%, MVV-40.4%, MIP-47.0% and VO2max-37.5%. No side effects were observed. G115 100 mg bid for three months, but not placebo, improved PFTs, MVV, MIP and VO2 max in patients with moderately-severe COPD with no side effects.

Post-partum hypocalcemia: idiopatic hypoparathyroidism manifested early in lactation

Hypocalcemia associated with labor and lactation is a rare condition reported previously in patients with hypovitaminosis D. We here describe a case of a young woman in whom symptomatic severe hypocalcemia appeared after her second delivery, early in lactation. At the end of lactation the condition worsened. We review all previously reported cases and suggest a possible physiologic explanation for the association between pregnancy, lactation and the appearance of symptomatic hypocalcemia.