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51.
The paper addresses the optimal design of the last supply chain branch, i.e., the Distribution Network (DN), starting from manufacturers till the retailers. It considers a distributed system composed of different stages connected by material links labeled with suitable performance indices. A hierarchical procedure employing direct graph (digraph) modeling, mixed integer linear programming, and the Analytic Hierarchy Process (AHP) is presented to select the optimal DN configuration. More in detail, a first-level DN optimization problem taking into account the definition and evaluation of the distribution chain performance provides a set of Pareto optimal solutions defined by digraph modeling. A second level DN optimization using the AHP method selects, on the basis of further criteria, the DN configuration from the Pareto face alternatives. To show the method effectiveness, the optimization model is applied to a case study describing an Italian regional healthcare drug DN. The problem solution by the proposed design method allows improving the DN flexibility and performance.  相似文献   
52.
Progression through the prophase of the first meiotic division can be obtained in culture by treatment of mouse spermatocytes with the serine/threonine phosphatase inhibitor okadaic acid. Chromosome condensation during this G2/M transition involves the activation of the MAPK pathway, which causes the activation of Nek2 and the phosphorylation of the chromatin architectural protein Hmga2. In an effort to set up conditions to allow a spontaneous progression of mouse spermatocytes through meiosis, we have investigated the cell-cycle features of these cells cultured for 24 h with a rotary cell culture system in a humidified atmosphere in a thermostatic incubator to simulate a microgravity environment. Morphological analysis of nuclear squashes indicated a 2-fold increase in late-pachytene spermatocytes with highly condensed chromosomes, and a contemporaneous decrease of mid-pachytene cells with less condensed chromatin. Microgravity induced a 2-fold activation of the cyclinB-cdc2 complex, confirming at the molecular level that cell-cycle progression had occurred. Moreover, using immuno-kinase assays with specific substrates we have demonstrated that the meiotic progression obtained under microgravity conditions is accompanied by activation of the Erk1/p90Rsk2 pathway. These data indicated that activation of the MAPK pathway correlates with chromatin condensation even under conditions in which meiotic progression occurs spontaneously and is not induced by a drug. We suggest that culture under microgravity conditions might help to release the block that inhibits isolated spermatocytes from progressing through prophase at unit gravity, and to study the physiological events of germ cell differentiation in vitro.  相似文献   
53.
Forty lactating Comisana ewes were either exposed to or protected from solar radiation and fed either in the morning or afternoon during summer in a Mediterranean climate. Individual milk samples were taken on days 7, 21 and 42 of the study period to determine fatty acid composition by gas chromatography. Exposure to solar radiation resulted in higher proportions of short-chain and saturated fatty acids in milk, primarily because of increased contents of caproic, capric, lauric, myristic and stearic acids (by 3-18%), and decreased contents of oleic, linoleic and linolenic acids (by 2-9%). As a consequence, the long to short chain and the unsaturated to saturated fatty acid ratios were significantly higher by 4 and 13% respectively in the milk of the protected ewes compared with that of the exposed animals. Provision of shade also led to an increase in the 18:0+18:1 to 16:0 ratio, and to a decrease in the 12:0 + 14:0 + 16:0 fatty acid group, which are regarded as reliable indexes of the nutritional property of dietary fat in reducing cholesterol levels in human plasma. Feeding time had little impact on milk fat. Our findings suggest that high ambient temperature may markedly modify the lipid composition of ewe milk and that provision of shade, but not feeding management, can improve the milk fatty acid profile in dairy sheep raised in hot climates.  相似文献   
54.
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   
55.
Follicular dendritic cell (FDC) proliferation in angioimmunoblastic T-cell lymphoma (AITL) is still not well defined, challenging the accurate differential diagnosis between the AITL with expanded follicular dendritic cell meshwork and the combined AITL and follicular dendritic cell sarcoma (FDCS). Herein, we reported the case of a 58-year-old male with coexisting SARS-CoV-2 infection and AITL with an exuberant CD30-positive FDC proliferation, in which genetic analysis identified mutations of genes commonly involved in AITL but not in FDC sarcoma (i.e., RHOA, TET2, DNMT3A, and IDH2), thus supporting the reactive nature of the CD30-positive FDC expansion.  相似文献   
56.
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   
57.
The paper addresses the issues of modelling and managing Intermodal Transportation Systems (ITS) at the operational level, considering the impact of the new Information and Communication Technologies (ICT). ITS are regarded as discrete event systems and are modelled in a timed Petri net framework. In order to show the efficiency of the ITS modelling and controlling technique, the case study of the ferry terminal of Trieste (Italy) is considered. The results show that the approach can be employed to verify the potential of ICT for efficient real time management of ITS, and their impact on the ITS infrastructures.  相似文献   
58.
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   
59.
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   
60.
This work introduces a formal analysis of the non-repudiation property for security protocols. Protocols are modelled in the process calculus LySa, using an extended syntax with annotations. Non-repudiation is verified using a Control Flow Analysis, following the same approach of Buchholtz and Gao for authentication and freshness analyses.The result is an analysis that can statically check the protocols to predict if they are secure during their execution and which can be fully automated.  相似文献   
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