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排序方式: 共有419条查询结果,搜索用时 234 毫秒
31.
32.
Michele Lo Giudice Giuseppe Varone Cosimo Ieracitano Nadia Mammone Giovanbattista Gaspare Tripodi Edoardo Ferlazzo Sara Gasparini Umberto Aguglia Francesco Carlo Morabito 《Entropy (Basel, Switzerland)》2022,24(1)
The differential diagnosis of epileptic seizures (ES) and psychogenic non-epileptic seizures (PNES) may be difficult, due to the lack of distinctive clinical features. The interictal electroencephalographic (EEG) signal may also be normal in patients with ES. Innovative diagnostic tools that exploit non-linear EEG analysis and deep learning (DL) could provide important support to physicians for clinical diagnosis. In this work, 18 patients with new-onset ES (12 males, 6 females) and 18 patients with video-recorded PNES (2 males, 16 females) with normal interictal EEG at visual inspection were enrolled. None of them was taking psychotropic drugs. A convolutional neural network (CNN) scheme using DL classification was designed to classify the two categories of subjects (ES vs. PNES). The proposed architecture performs an EEG time-frequency transformation and a classification step with a CNN. The CNN was able to classify the EEG recordings of subjects with ES vs. subjects with PNES with 94.4% accuracy. CNN provided high performance in the assigned binary classification when compared to standard learning algorithms (multi-layer perceptron, support vector machine, linear discriminant analysis and quadratic discriminant analysis). In order to interpret how the CNN achieved this performance, information theoretical analysis was carried out. Specifically, the permutation entropy (PE) of the feature maps was evaluated and compared in the two classes. The achieved results, although preliminary, encourage the use of these innovative techniques to support neurologists in early diagnoses. 相似文献
33.
This paper reports the preparation and characterization of the homologous series of layered zirconium fluoride n-alkylamino-N,N-bis methylphosphonates, of general formula ZrF(O(3)PCH(2))(2)NHC(n)H(2n+1) (n = 1, 2, 3, 4, 5, 6, 8, 9, 10), in which the two phosphonic groups of each diphosphonate building block participate in the assembly of a single lamella, because they are joined to zirconium atoms belonging to the same layer. The crystal structure of one of the series of these zirconium diphosphonates, ZrF(O(3)PCH(2))(2)NHC(5)H(11), has been solved "ab initio" by X-ray powder diffraction data. The structure is monoclinic, space group P2(1)/c. The zwitterionic character of the diphosphonate moiety is a distinctive feature which acts as a structure-orienting factor, generating a layer framework which is different from the other structures known for zirconium phosphates and phosphonates. This compound undergoes a phase transition at 117 degrees C which involves a rearrangement of the interlayer alkyl chains. The structure of the high-temperature phase has been refined by the Rietveld method. Because only one organic residue is associated with two phosphonate tetrahedra, a poorly hindered interlayer region is formed, and alkyl chains bonded to adjacent layers are interdigitated. Preliminary experiments have shown that these compounds are able to intercalate organic molecules, such as n-alkanols, from very dilute water solutions. 相似文献
34.
Salvatore Pignataro Giovanni Marletta Orazio Puglisi Umberto Costantino Giulio Alberti 《Journal of Electron Spectroscopy and Related Phenomena》1982,25(1):49-57
Mg Kα ESCA spectra of several α-Zr(PO4)2M2 compounds (M = Li+, Na+, K+, Cs+) have been obtained. Satellite structure is observed at ~7–8 eV from the main P 2s peak (corresponding to ~15–16 eV from the main Zr 3d peak). The intensity of the satellite depends on the counter-ion intercalated. For a given counter-ion it is strongly increased by sputtering, the rate of increase being also dependent on the counter-ion. This observation is interpreted mainly in terms of electron-defect formation similar to that involved in the formation of colour centres by radiation damage, and subsequent charge-transfer shake-up of the trapped electrons to the electron-deficient phosphorus or Zr(IV) centres. 相似文献
35.
Umberto Cerruti 《Journal of Mathematical Analysis and Applications》1983,94(2):312-327
It is shown that the category of complete L-similarities on L-sets is a full reflective subcategory of (L) (L-fuzzy graphs); is equivalent to (L)(sheaves on L). Connections with other known “fuzzy” categories are also studied. 相似文献
36.
Summary In this paper we study the Dirichlet problem for the minimal surface equation in a open set Ω without any assumption about
the regularity of ϖΩ. We prove an existence theorem using only the pseudoconvexity of Ω.
Riassunto In questo lavoro studiamo il problema di Dirichlet per l'equazione delle superfici minime in un aperto Ω diR n sulla cui frontiera non si fa nessuna ipotesi di regolarità. Si ottiene un teorema di esistenza usando la sola pseudoconvessità di Ω.相似文献
37.
Canevali C Mari CM Mattoni M Morazzoni F Nodari L Ruffo R Russo U Scotti R 《The journal of physical chemistry. B》2005,109(15):7195-7202
The mechanism of NO interaction with nanosized Ru(Pd,Pt)-doped SnO(2) was studied by electron paramagnetic resonance, M?ssbauer, and electric resistance measurements. Three steps were proposed for the reaction between the semiconductor oxide and the gaseous component: (i) the formation of bielectronic oxygen vacancies (V(o)) in SnO(2); (ii) their single-ionization (V(o)(*)) with injection of electrons into the SnO(2) conduction band; (iii) the subsequent transfer of electrons from V(o)(*) to [Ru(Pd,Pt)](4+). The last process induces the formation of further oxygen vacancies which reduce the transition metal centers to lower oxidation states; the redox processes is enhanced and the electrical resistance in transition metal-doped SnO(2) is stronger modified with respect to the undoped material. 相似文献
38.
Stepwise amination of cyanuric chloride (1) with 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (2) and/or its zinc(II) complex (3) enables the synthesis of porphyrin-porphyrin dyads with predetermined free base-free base forms or free base-zinc and zinc-zinc metalation states. Furthermore, the use of aminopropyl-silanized silica gel as a scavenger for unwanted byproducts allowed the one-pot synthesis of title porphyrin compounds in high yield and purity with minimum use of preparative column chromatography. 相似文献
39.
Bellezza F Cipiciani A Costantino U Nicolis S 《Langmuir : the ACS journal of surfaces and colloids》2004,20(12):5019-5025
The adsorption and catalytic activity of myoglobin (Mb) on zirconium phosphonates (a-zirconium benzenephosphonate (alpha-ZrBP), a-zirconium carboxyethanephosphonate (alpha-ZrCEP), and a novel layered zirconium fluoride aminooctyl-N,N-bis(methylphosphonate) (ZrC8)) were investigated. The maximum adsorption was reached after 16 h of contact and was greater on hydrophobic supports such as alpha-ZrBP and ZrC8 compared to hydrophilic supports such as alpha-ZrCEP. The equilibrium adsorption isotherms fitted the Langmuir equation, suggesting the presence of a monolayer of protein molecules on the support surfaces. The catalytic activities of free Mb and of the obtained biocomposites were studied in terms of the oxidation of two aromatic substrates, o-phenylenediamine and 2-methoxyphenol (guaiacol), by hydrogen peroxide. The oxidation catalyzed by immobilized myoglobin followed the Michaelis-Menten kinetics, similar to oxidation by free Mb. The kinetic parameters, kcat and KM, were significantly affected by the adsorption process. Mb/alpha-ZrCEP was the most efficient biocatalyst obtained, probably because of the hydrophilic nature of the support. The effect of immobilization on the stability of Mb toward inactivation by hydrogen peroxide was also investigated, and an increased resistance was found. The biocomposites obtained can be stored at 4 degrees C for months without a significant loss of catalytic activity. 相似文献
40.
Piarulli U Claverie C Daubos P Gennari C Minnaard AJ Feringa BL 《Organic letters》2003,5(23):4493-4496
[reaction: see text] A highly regio-, diastereo-, and enantioselective desymmetrization of five-, six-, and seven-membered meso-cyclic allylic bis-diethyl phosphates (2a, 2b, and 2c, respectively) was obtained with diethylzinc, using catalytic amounts of [Cu(OTf)](2).C(6)H(6) and phosphoramidite ligands 5. Enantiomeric excesses of up to 87, 94, and >98% were obtained for the addition of diethylzinc to cyclopentene, cyclohexene, and cycloheptene bis-diethyl phosphates, respectively. 相似文献