Optimal discretization of grounding systems applying Maxwell's subareas method

This paper presents a method for evaluating the optimal number n of equivalent sources needed for simulating grounding systems by the Maxwell's subareas method. It is well known that the number of elements in which electrodes are subdivided plays a role on the accuracy and reliability of results (as well as on computational time). Previous studies, accomplished through iterative calculations (performed with different segmentations), led mostly to some recommended practices for the identification of lower and upper bounds for n. The procedure proposed in this paper allows for predicting the optimal n in a single process. The method starts from the identification of a set of appropriate scalar functions, which heuristically express a relation between the number of subareas and the accuracy of the results (earth resistance and earth surface voltages) computed applying the Maxwell's subareas method. Then, a multi-objective optimization process evaluates the number n* that maximizes that accuracy

Laparoscopic bilateral hand-assisted nephrectomy: end-stage renal disease from tuberculosis, an unusual indication for nephrectomy before transplantation.

The purpose of the study was to sterilize renal tuberculous foci in a pretransplantation patient with a laparoscopic hand-assisted approach and to verify the feasibility of bilateral nephrectomy for this indication. This case report is the first description of hand-assisted laparoscopic bilateral nephrectomy for this pathologic condition. The 33-year-old patient had end-stage renal disease from renal tuberculosis. A commercially available hand-assistance device was used through a midline 8-cm supraumbilical incision and with four ports. The procedure was successfully completed. The total operative time was 3 hours and 40 minutes. Estimated blood loss was 250 mL. The postoperative course was uneventful, and clinical follow-up at 3 weeks revealed a successful outcome. Hand-assisted bilateral laparoscopic nephrectomy in patients with chronic renal failure from tuberculosis represents a viable option because it is feasible and effective. The hand-assisted approach increases the safety of the procedure while retaining all the advantages of minimally invasive surgery

Unconventional Metallic Magnetism in LaCrSb{3}

Neutron-diffraction measurements in LaCrSb{3} show a coexistence of ferromagnetic and antiferromagnetic sublattices below Tc=126 K, with ordered moments of 1.65(4) and 0.49(4) Bohr magnetons per formula unit, respectively (T=10 K), and a spin reorientation transition at ~95 K. No clear peak or step was observed in the specific heat at Tc. Coexisting localized and itinerant spins are suggested.Comment: PRL, in pres

Detection of possible factors favouring the evolution of migraine without aura into chronic migraine

In a minority of cases, the natural history of migraine without aura (MO) is characterised over time by its evolution into a form of chronic migraine (CM). In order to detect the possible factors predicting this negative evolution of MO, we searched in our Headache Centre files for all clinical records that met the following criteria: (a) first visit between 1976 and 1998; (b) diagnosis of MO or of common migraine at the first observation, with or without association with other primary headache types; (c) <15 days per month of migraine at the first observation; and (d) at least one follow-up visit at least 10 years after the first visit. The patients thus identified were then divided into two groups based on a favourable/steady evolution (Group A: n = 243, 195 women and 48 men) or an unfavourable evolution (Group B: n = 72, 62 women and 10 men) of their migraine over time. In the two groups, we compared various clinical parameters that were present at the first observation or emerged at the subsequent follow-up visits. The parameters that were statistically significantly more frequent in Group B--and can therefore be considered possible negative prognostic factors--were: (a) ≥ 10 days per month of migraine at the first observation; (b) presence of depression at the first visit in males; and (c) onset of depression or arterial hypertension after the first observation but before transformation to CM in females. Based on these findings, in MO patients the high frequency of migraine attacks, comorbidity with depression, and the tendency to develop arterial hypertension should require particular attention and careful management to prevent evolution into CM

Isolated, subtle, neurological abnormalities in neurologically and cognitively healthy aging subjects

The aim of this study is to describe the frequency of isolated, subtle, neurological abnormalities (ISNAs) in a large population of neurologically and cognitively healthy subjects and to compare ISNAs to various types of MRI-detected cerebrovascular lesions and subcortical brain atrophy in different age classes. 907 subjects were selected from a large, prospective hospital-based study. At baseline neurological examination, 17 ISNAs were selected. Primitive reflexes were the most common ISNAs (35.8&nbsp;%), while dysphagia was the most rarely encountered (0.3&nbsp;%). Measures of small vessel disease, i.e., deep and subcortical white matter hyperintensity and lacunar infarcts as well as subcortical atrophy, were variously associated with ISNAs. In the adult group, the ISNAs were associated with hypertriglyceridemia, TIA, and subcortical lacunar infarcts, while in the elderly-old group they were associated with arterial hypertension, subcortical white matter hyperintensity, and subcortical atrophy. An increased risk of ISNAs was associated with lacunae and white matter hyperintensity in the parietal region. This study shows that white matter hyperintensity, lacunae, and subcortical atrophy are associated with an increased risk of ISNAs in cognitively and neurologically healthy aging subjects. ISNAs are not benign signs. Therefore, adults and elderly people presenting with ISNAs should have access to accurate history and diagnosis to prevent progression of small vessel disease and future neurological and cognitive disabilities

K-edge X-ray absorption spectra in transition metal oxides beyond the single particle approximation: shake-up many body effects

The near edge structure (XANES) in K-edge X-ray absorption spectroscopy (XAS) is a widely used tool for studying electronic and local structure in materials. The precise interpretation of these spectra with the help of calculations is hence of prime importance, especially for the study of correlated materials which have a complicated electronic structure per se. The single particle approach, for example, has generally limited itself to the dominant dipolar cross-section. It has long been known however that effects beyond this approach should be taken into account, both due to the inadequacy of such calculations when compared to experiment and the presence of shake-up many-body satellites in core-level photoemission spectra of correlated materials. This effect should manifest itself in XANES spectra and the question is firstly how to account for it theoretically and secondly how to verify it experimentally. By using state-of-the-art first principles electronic structure calculations and 1s photoemission measurements we demonstrate that shake-up many-body effects are present in K-edge XAS dipolar spectra of NiO, CoO and CuO at all energy scales. We show that shake-up effects can be included in K-edge XAS spectra in a simple way by convoluting the single-particle first-principles calculations including core-hole effects with the 1s photoemission spectra. We thus describe all features appearing in the XAS dipolar cross-section of NiO and CoO and obtain a dramatic improvement with respect to the single-particle calculation in CuO. These materials being prototype correlated magnetic oxides, our work points to the presence of shake-up effects in K-edge XANES of most correlated transition metal compounds and shows how to account for them, paving the way to a precise understanding of their electronic structure.Comment: 6 pages, 4 picture

Proximity-induced ferromagnetism and chemical reactivity in few-layer VSe2 heterostructures

Among transition-metal dichalcogenides, mono and few-layers thick VSe2 has gained much recent attention following claims of intrinsic room-temperature ferromagnetism in this system, which have nonetheless proved controversial. Here, we address the magnetic and chemical properties of Fe/VSe2 heterostructure by combining element sensitive x-ray absorption spectroscopy and photoemission spectroscopy. Our x-ray magnetic circular dichroism results confirm recent findings that both native mono/few-layer and bulk VSe2 do not show intrinsic ferromagnetic ordering. Nonetheless, we find that ferromagnetism can be induced, even at room temperature, after coupling with a Fe thin film layer, with antiparallel alignment of the moment on the V with respect to Fe. We further consider the chemical reactivity at the Fe/VSe2 interface and its relation with interfacial magnetic coupling

Local magnetic moment coupling of Gd on Fe(100) studied by magnetic dichroism in angular-dependent photoemission

We measured the magnetic linear dichroism in the angular distribution (MLDAD) of photoemission of thin Gd layers on Fe(100). At low photon energies large MLDAD asymmetries, up to 40%, in the (Formula presented) photoemission were observed. The line shape and the photon-energy dependence of the measured MLDAD are in good agreement with theoretical results. Analysis of the (Formula presented) and (Formula presented) magnetic signals indicates an antiferromagnetic coupling between Gd and Fe, confirming previous findings. We also demonstrate that the MLDAD plus-minus feature is governed by the orbital magnetic moment of the core hole state

Detection of Listeria monocytogenes in foods with a textile organic electrochemical transistor biosensor

Abstract: Foods contaminated by pathogens are responsible for foodborne diseases which have socioeconomic impacts. Many approaches have been extensively investigated to obtain specific and sensitive methods to detect pathogens in food, but they are often not easy to perform and require trained personnel. This work aims to propose a textile organic electrochemical transistor-based (OECT) biosensor to detect L. monocytogenes in food samples. The analyses were performed with culture-based methods, Listeria Precis™ method, PCR, and our textile OECT biosensor which used poly(3,4-ethylenedioxythiophene) (PEDOT):polystyrene sulfonate (PSS) (PEDOT:PSS) for doping the organic channel. Atomic force microscopy (AFM) was used to obtain topographic maps of the gold gate. The electrochemical activity on gate electrodes was measured and related to the concentration of DNA extracted from samples and hybridized to the specific capture probe immobilized onto the gold surface of the gate. This assay reached a limit of detection of 1.05 ng/μL, corresponding to 0.56 pM of L. monocytogenes ATCC 7644, and allowed the specific and rapid detection of L. monocytogenes in the analyzed samples. Keypoints: • Textile organic electrochemical transistors functionalized with a specific DNA probe • AFM topographic and surface potential maps of a functionalized gold gate surface • Comparison between the Listeria monocytogenes Precis™ method and an OECT biosenso