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41.
Among 41 consecutive children with classic Noonan syndrome, 27 patients (66%) presented cardiac anomalies. Eight patients (19.5%) had a congenital anomaly of the mitral valve consisting of 5 with partial atrioventricular canal defect and 3 with anomalous insertion of the mitral valve on the ventricular septum. Five patients (12%) presented with a significant left ventricular outflow tract obstruction caused by the anterior leaflet of the mitral valve: two cases with atrioventricular canal and three cases with isolated anomalous insertion of the mitral valve. Echocardiography is the best tool for the diagnosis. Cardiac defects of patients with Noonan syndrome may be explained on the basis of anomalies of the extracellular matrix involving cardiac valves including the mitral valve. CONCLUSION: In children with Noonan syndrome and left ventricular hypertrophy a careful echocardiographic assessment of the mitral valve should reveal those in whom the left ventricular outflow tract obstruction is anatomical in nature.  相似文献   
42.
This paper deals with gold extraction from a refractory concentrate by chlorine leaching. The process considers a pre-treatment of refractory materials by low temperature oxidation carried out with low oxygen concentration. The oxidized material is treated by leaching with brine. After gold adsorption/reduction onto activated carbon, iron and base metals can be precipitated by NaOH. Roasting tests show the necessity to carry out a thermal pre-treatment at least at 550 °C to obtain a reduction of sulfur and mercury in the material (50% and 90%, respectively). Highest gold extraction yield (around 93%) is obtained in the leaching test performed with material sample treated at 650 °C. This result confirms the necessity to optimize the thermal pre-treatment to improve Au recovery and to reduce chlorine consumption. A comparison with conventional cyanidation confirms that chlorination could be an useful alternative: in fact, gold extraction yield is quite low: 57% in non-pre-treated material and 25% in pre-treatment material.  相似文献   
43.
Sheinwald, Lempel, and Ziv (1995,Inform. and Comput.116, 128–133) proved that the power of off-line coding is not useful if we want on-line decodable files, as far as asymptotical results are concerned. In this paper, we are concerned with the finite case and consider the notion of on-line decodable optimal parsing based on the parsing defined by the Ziv–Lempel (LZ2) compression algorithm. De Agostino and Storer (1996,Inform. Process. Lett.59, 169–174) proved the NP-completeness of computing the optimal parsing and that a sublogarithmic factor approximation algorithm cannot be realized on-line. We show that the Ziv–Lempel algorithm and two widely used practical implementations produce an O(n1/4) approximation of the optimal parsing, wherenis the length of the string. By working with de Bruijn sequences, we show also infinite families of binary strings on which the approximation factor isΘ(n1/4).  相似文献   
44.
Different kinds of technological data are available in manufacturing enterprises, concerning the resources available as well as the processes and the components needed for the production of specific products. These data usually are not stored in a centralized knowledge management system, thus one of the main problem of managers, especially in small enterprises, is to efficiently manage their data and reuse the knowledge deriving from previous products when a new product has to be produced. Starting form the analysis of the technological data available in manufacturing enterprises, we defined a formal model as set of matrices; their analysis allows the definition of a data model to structure the technological information. The model is at the basis of the proposed system, called manufacturing knowledge organization (MAKO) to support managers in structuring and reusing the technological knowledge available in their enterprise. A prototype of the MAKO system was implemented by using open-source software and its potentialities are shown in a case study.  相似文献   
45.
In many situations we are interested in appraising the value of a certain characteristic for a given individual relative to the context in which this value is observed. In recent years this problem has become prominent in the evaluation of scientific productivity and impact. A popular approach to such relative valuations consists in using percentile ranks. This is a purely ordinal method that may sometimes lead to counterintuitive appraisals, in that it discards all information about the distance between the raw values within a given context. By contrast, this information is partly preserved by using standardization, i.e., by transforming the absolute values in such a way that, within the same context, the distance between the relative values is monotonically related to the distance between the absolute ones. While there are many practically useful alternatives for standardizing a given characteristic across different contexts, the general problem seems to have never been addressed from a theoretical and normative viewpoint. The main aim of this paper is to fill this gap and provide a conceptual framework that allows for this kind of systematic investigation. We then use this framework to prove that, under some rather weak assumptions, the general format of a standardization function can be determined quite sharply.  相似文献   
46.
This paper addresses the problem of identifying the model of the unobservable behaviour of discrete event systems in the industrial automation sector. Assuming that the fault-free system structure and dynamics are known, the paper proposes an algorithm that monitors the system on-line, storing the occurred observable event sequence and the corresponding reached states. At each event observation, the algorithm checks whether some unobservable events have occurred on the basis of the knowledge of the Petri net (PN) modelling the nominal system behaviour and the knowledge of the current PN marking. By defining and solving some integer linear programming problems, the algorithm decides whether it is necessary to introduce some unobservable (silent) transitions in the PN model and provides a PN structure that is consistent with the observed event string. A case study describing an industrial automation system shows the efficiency and the applicability of the proposed algorithm.  相似文献   
47.
Secretory phospholipases A2 (sPLA2s) are implicated in the pathogenesis of several inflammation diseases, such as rheumatoid arthritis, septic shock, psoriasis, and asthma. Thus, an understanding of their inactivation mechanisms could be useful for the development of new classes of chemical selective inhibitors. In the marine environment, several bioactive terpenoids possess interesting anti‐inflammatory activity, often through covalent and/or noncovalent inactivation of sPLA2. Herein, we report the molecular mechanism of human group IIA phospholipase A2 (sPLA2‐IIA) inactivation by Scalaradial (SLD), a marine 1,4‐dialdehyde terpenoid isolated from the sponge Cacospongia mollior and endowed with a significant anti‐inflammatory profile. Our results have been collected by a combination of biochemical approaches, advanced mass spectrometry, surface plasmon resonance, and molecular modeling. These suggest that SLD acts as a competitive inhibitor. Indeed, the sPLA2‐IIA inactivation process seems to be driven by the noncovalent recognition process of SLD in the enzyme active site and by chelation of the catalytic calcium ion. In contrast, covalent modification of the enzyme by the SLD dialdehyde moiety emerges as only a minor side event in the ligand–enzyme interaction. These results could be helpful for the rational design of new PLA2 inhibitors that would be able to selectively target the enzyme active site.  相似文献   
48.
In order to reduce waste of marine resources, valorise fishing discards and move towards fish consumption, a new ready-to-cook seafood product was developed. In particular, a chemical investigation on chub mackerel and hake was conducted to the aim of mixing the two fish species to produce nutritionally balanced fish burgers. In addition, to evaluate consumer opinion about these new fresh products and best acceptability of different proportions of mackerel and hake, focus group interviews and consumer test were also performed. The results of the chemical analyses achieved on both selected fish species gave rise to minimally processed fish products with a high amount of chub mackerel, therefore providing the desired nutritional properties and low level of hake in order to obtain firmer and wetter burgers. By means of focus group interviews, the novelty and high level of convenience of the developed fresh commodity was highlighted. Consumer test declared that the most successful sample was that with 70% chub mackerel and 30% hake.  相似文献   
49.
The fabrication of solid-supported artificial lipid bilayers enriched with biological agents is an important step for acquiring more insights into their behavior from in vitro studies. In this work we demonstrate the formation of lipid artificial membranes enriched with ganglioside GM3, whose role in the cell proliferation and tumor angiogenesis is still an object of extensive investigation. The membranes are formed by fusion of small unilamellar vesicles (SUV) obtained from the sonication of multi-lamellar vesicles (MLV) formed from a hydrated mixture of GM3, brain sphingomyelin and cholesterol. The effective formation of SUV was confirmed by Dynamic light scattering (DLS) measurements. The recognition of the ganglioside in the biomimetic raft like biomembranes is accomplished via surface plasmon resonance (SPR) by exploiting the ganglioside affinity with wheat germ agglutinin (WGA). The affinity constant of the binding between the inglobated GM3 and WGA has been measured for three different GM3 molar concentrations. Beside the effective generation of GM3-enriched biomimetic membranes, our results indicate a decrease in the apparent WGA–GM3 dissociation constant at increasing GM3 concentrations up to 20 mol%, consistent with clustering effects of the ganglioside in the fabricated biomembranes.  相似文献   
50.
The study is focused on the extraction of valuable metals from automotive shredder residue (ASR) by different leaching solutions. First, ASR samples were roasted at 600 °C to simulate a thermal treatme...  相似文献   
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