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21.
A study of the effect of long-term alcohol consumption on the liver of well-nourished rats is described. Rats fed for 16 weeks on a semipurified diet supplemented with high levels of vitamins and lipotropic factors and alcohol corresponding to 35% of the total caloric intake developed marked fatty changes of the liver. Mild fatty changes were observed in pair-fed controls receiving as isoenergetic equivalent of sucrose instead of alcohol. Intracellular hyaline bodies, corresponding ultrastructurally to giant mitochondria were abundantly found in the hepatocytes of alcoholic rats, while in the controls they were not seen. Te findings in this investigation are postulated to provide further evidence that the long-term intake of alcohol exerts a direct causative role in the pathogenesis of liver damage.  相似文献   
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23.
The kinetics of the overall reactions of carbon gasification at temperatures up to 1600 K is studied. The kinetic characteristics of the reactions are taken into account in a distributed mathematical model of filtration combustion of carbon. By computational experiment at different values of process control parameters (the gas flow rate, the fraction of the oxidant in the gas, and the mass ratio of carbon to the inert material in the combustible mixture), it is found that, in the wave of filtration combustion of carbon under superadiabatic conditions, carbon gasification can predominately yield either CO2 or CO.  相似文献   
24.
Given the strong increase in regulatory requirements for business processes the management of business process compliance becomes a more and more regarded field in IS research. Several methods have been developed to support compliance checking of conceptual models. However, their focus on distinct modeling languages and mostly linear (i.e., predecessor-successor related) compliance rules may hinder widespread adoption and application in practice. Furthermore, hardly any of them has been evaluated in a real-world setting. We address this issue by applying a generic pattern matching approach for conceptual models to business process compliance checking in the financial sector. It consists of a model query language, a search algorithm and a corresponding modelling tool prototype. It is (1) applicable for all graph-based conceptual modeling languages and (2) for different kinds of compliance rules. Furthermore, based on an applicability check, we (3) evaluate the approach in a financial industry project setting against its relevance for decision support of audit and compliance management tasks.  相似文献   
25.
During software system evolution, software architects intuitively trade off the different architecture alternatives for their extra-functional properties, such as performance, maintainability, reliability, security, and usability. Researchers have proposed numerous model-driven prediction methods based on queuing networks or Petri nets, which claim to be more cost-effective and less error-prone than current practice. Practitioners are reluctant to apply these methods because of the unknown prediction accuracy and work effort. We have applied a novel model-driven prediction method called Q-ImPrESS on a large-scale process control system from ABB consisting of several million lines of code. This paper reports on the achieved performance prediction accuracy and reliability prediction sensitivity analyses as well as the effort in person hours for achieving these results.  相似文献   
26.
The crystal structure of transducin's betagamma subunits complexed with phosducin, which regulates Gtbetagamma activity, has been solved to 2.4 angstroms resolution. Phosducin has two domains that wrap around Gtbetagamma to form an extensive interface. The N-terminal domain binds loops on the "top" Gtbeta surface, overlapping the Gtalpha binding surface, explaining how phosducin blocks Gtbetagamma's interaction with Gtalpha. The C-terminal domain shows structural homology to thioredoxin and binds the outer strands of Gtbeta's seventh and first blades in a manner likely to disrupt Gtbetagamma's normal orientation relative to the membrane and receptor. Phosducin's Ser-73, which when phosphorylated inhibits phosducin's function, points away from Gtbetagamma, toward a large flexible loop. Thus phosphorylation is not likely to affect the interface directly, but rather indirectly through an induced conformational change.  相似文献   
27.
Investigators have traditionally thought of the class of inflammation- and injury-associated cytokines in large part as "free" entities in the peripheral circulation. In the case of interleukin-6 (IL-6), the cytokine can be found in blood in complexes of molecular mass 400-500, 150-200, and 25-35 kDa in association with binding proteins that can include soluble IL-6 receptor (sIL-6R), anti-IL-6, and anti-sIL-6R IgG, and others. Sustained high levels of different particular IL-6 complexes are observed in the human circulation in cancer patients subjected to particular active anticancer immunotherapy regimens. In the "chaperoned" state, circulating IL-6 complexes display differential immunoreactivity in different ELISAs and possess differential biological activity as assayed ex vivo. The discovery of "chaperoned" circulating IL-6 in humans points to a new level of modulation of cytokine function, that of regulated bioavailability of IL-6 in vivo.  相似文献   
28.
Context: A number of approaches have been proposed for the general problem of software component evaluation and selection. Most approaches come from the field of Component-Based Software Development (CBSD), tackle the problem of Commercial-off-the-shelf component selection and use goal-oriented requirements modelling and multi-criteria decision making techniques. Evaluation of the suitability of components is carried out largely manually and partly relies on subjective judgement. However, in dynamic, distributed environments with high demands for transparent selection processes leading to trustworthy, auditable decisions, subjective judgements and vendor claims are not considered sufficient. Furthermore, continuous monitoring and re-evaluation of components after integration is sometimes needed.Objective: This paper describes how an evidence-based approach to component evaluation can improve repeatability and reproducibility of component selection under the following conditions: (1) Functional homogeneity of candidate components and (2) High number of components and selection problem instances.Method: Our evaluation and selection method and tool empirically evaluate candidate components in controlled experiments by applying automated measurements. By analysing the differences to system-development-oriented scenarios, the paper shows how the process of utility analysis can be tailored to fit the problem space, and describes a method geared towards automated evaluation in an empirical setting. We describe tool support and a framework for automated measurements.We further present a taxonomy of decision criteria for the described scenario and discuss the data collection means needed for each category of criteria.Results: To evaluate our approach, we discuss a series of case studies in the area of digital preservation. We analyse the criteria defined in these case studies, classify them according to the taxonomy, and discuss the quantitative coverage of automated measurements.Conclusion: The results of the analysis show that an automated measurement, evaluation and selection framework is necessary and feasible to ensure trusted and repeatable decisions.  相似文献   
29.
Confronted with decreasing margins and a rising customer demand for integrated solutions, manufacturing companies integrate complementary services into their portfolio. Offering value bundles (consisting of services and physical goods) takes place in integrated product–service systems, spanning the coordinated design and delivery of services and physical goods for customers. Conceptual Modeling is an established approach to support and guide such efforts. Using a framework for the design and delivery of value bundles as an analytical lens, this study evaluates the current support of reference models and modeling languages for setting up conceptual models for an integrated design and delivery of value bundles. Consecutively, designing modeling languages and reference models to fit the requirements of conceptual models in product–service systems are presented as upcoming challenges in Service Research. To guide further research, first steps are proposed by exemplarily integrating reference models and modeling languages stemming from the service and manufacturing domains.  相似文献   
30.
The purpose of this study was to determine if a change in forward head posture and occipital extension occurred in participants who wore multifocal lenses vs. those persons with non-multifocal lenses while performing an 8-min visual reading task on a visual display unit (VDU). Forty-two healthy human participants were recruited for this study. Thirty-three participants completed the study. Fourteen participants wore multifocal lenses and 19 wore frames with non-multifocal lenses. To evaluate the degree of change of forward head posture and occipital extension digital photographs of cervical posture were taken at four different time intervals: prior to performing the reading task and at 3, 5 and 8 min during the reading task. The digital photographs were analysed utilizing a computer program. Two one-way ANOVA were utilized to determine the degree of change of forward head posture and occipital extension between groups. A significant difference was identified between groups for changes in degrees of forward head posture while performing a visual reading task on a VDU. However, no significant difference between groups was found for occipital extension while performing the same task. Multifocal wearers exhibit greater degrees of change in forward head posture and occipital extension than non-multifocal wearers. These postural changes may place them at a greater risk for musculoskeletal disorders and headaches.  相似文献   
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