863 resultados para To-monomer Transformation
Resumo:
BACKGROUND: The aim of this retrospective and monocentric study was to describe the magnetic resonance cholangiography (MRC) features of biliary abnormalities related to extrahepatic obstruction of the portal vein (EHOPV). METHODS: From September 2001 to May 2003, MRC was performed in 10 consecutive patients who had a portal thrombosis. RESULTS: Biliary ductal pathology was demonstrated via MRC in nine patients. It consisted of stenoses, ductal narrowing or irregularities involving the common bile duct for three patients with extrahepatic portal vein thrombosis discovered a mean of 1.5 years ago, or involving both right and left intrahepatic bile ducts and common bile duct for six patients with extrahepatic portal vein thrombosis discovered a mean of 16.2 years ago. Dilation of intrahepatic bile ducts was seen for seven patients, four of them having cholestasis. For three patients with symptomatic cholestasis, direct cholangiography (DC) was performed and showed the same findings as MRC which nevertheless overestimated the degree of bile duct stenosis. CONCLUSIONS: MRC seems to constitute an accurate tool to investigate noninvasively patients with portal biliopathy.
Resumo:
A dipeptide with a long fatty acid chain at its N-terminus gives hydrogels in phosphate buffer in the pH range 7.0–8.5. The hydrogel with a gelator concentration of 0.45% (w/v) at pH 7.46 (physiological pH) provides a very good platform to study dynamic changes within a supramolecular framework as it exhibits remarkable change in its appearance with time. Interestingly, the first formed transparent hydrogel gradually transforms into a turbid gel within 2 days. These two forms of the hydrogel have been thoroughly investigated by using small angle X-ray scattering (SAXS), powder X-ray diffraction (PXRD), field emission scanning electron microscopic (FE-SEM) and high-resolution transmission electron microscopic (HR-TEM) imaging, FT-IR and rheometric analyses. The SAXS and low angle PXRD studies substantiate different packing arrangements for the gelator molecules for these two different gel states (the freshly prepared and the aged hydrogel). Moreover, rheological studies of these two gels reveal that the aged gel is stiffer than the freshly prepared gel.
Resumo:
Although abundant in well-differentiated rat thyroid cells, Rap1GAP expression was extinguished in a subset of human thyroid tumor-derived cell lines. Intriguingly, Rap1GAP was downregulated selectively in tumor cell lines that had acquired a mesenchymal morphology. Restoring Rap1GAP expression to these cells inhibited cell migration and invasion, effects that were correlated with the inhibition of Rap1 and Rac1 activity. The reexpression of Rap1GAP also inhibited DNA synthesis and anchorage-independent proliferation. Conversely, eliminating Rap1GAP expression in rat thyroid cells induced a transient increase in cell number. Strikingly, Rap1GAP expression was abolished by Ras transformation. The downregulation of Rap1GAP by Ras required the activation of the Raf/MEK/extracellular signal-regulated kinase cascade and was correlated with the induction of mesenchymal morphology and migratory behavior. Remarkably, the acute expression of oncogenic Ras was sufficient to downregulate Rap1GAP expression in rat thyroid cells, identifying Rap1GAP as a novel target of oncogenic Ras. Collectively, these data implicate Rap1GAP as a putative tumor/invasion suppressor in the thyroid. In support of that notion, Rap1GAP was highly expressed in normal human thyroid cells and downregulated in primary thyroid tumors.
Resumo:
Our recent studies have shown that the FoxM1B transcription factor is overexpressed in human glioma tissues and that the level of its expression correlates directly with glioma grade. However, whether FoxM1B plays a role in the early development of glioma (i.e., in transformation) is unknown. In this study, we found that the FoxM1B molecule causes cellular transformation and tumor formation in normal human astrocytes (NHA) immortalized by p53 and pRB inhibition. Moreover, brain tumors that arose from intracranial injection of FoxM1B-expressing immortalized NHAs displayed glioblastoma multiforme (GBM) phenotypes, suggesting that FoxM1B overexpression in immortalized NHAs not only transforms the cells but also leads to GBM formation. Mechanistically, our results showed that overexpression of FoxM1B upregulated NEDD4-1, an E3 ligase that mediates the degradation and downregulation of phosphatase and tensin homologue (PTEN) in multiple cell lines. Decreased PTEN in turn resulted in the hyperactivation of Akt, which led to phosphorylation and cytoplasmic retention of FoxO3a. Blocking Akt activation with phosphoinositide 3-kinase/Akt inhibitors inhibited the FoxM1B-induced transformation of immortalized NHAs. Furthermore, overexpression of FoxM1B in immortalized NHAs increased the expression of survivin, cyclin D1, and cyclin E, which are important molecules for tumor growth. Collectively, these results indicate that overexpression of FoxM1B, in cooperation with p53 and pRB inhibition in NHA cells, promotes astrocyte transformation and GBM formation through multiple mechanisms.
Resumo:
Software Product Line Engineering has significant advantages in family-based software development. The common and variable structure for all products of a family is defined through a Product-Line Architecture (PLA) that consists of a common set of reusable components and connectors which can be configured to build the different products. The design of PLA requires solutions for capturing such configuration (variability). The Flexible-PLA Model is a solution that supports the specification of external variability of the PLA configuration, as well as internal variability of components. However, a complete support for product-line development requires translating architecture specifications into code. This complex task needs automation to avoid human error. Since Model-Driven Development allows automatic code generation from models, this paper presents a solution to automatically generate AspectJ code from Flexible-PLA models previously configured to derive specific products. This solution is supported by a modeling framework and validated in a software factory.
Resumo:
Receptors coupled to heterotrimeric G proteins can effectively stimulate growth promoting pathways in a large variety of cell types, and if persistently activated, these receptors can also behave as dominant-acting oncoproteins. Consistently, activating mutations for G proteins of the Gαs and Gαi2 families were found in human tumors; and members of the Gαq and Gα12 families are fully transforming when expressed in murine fibroblasts. In an effort aimed to elucidate the molecular events involved in proliferative signaling through heterotrimeric G proteins we have focused recently on gene expression regulation. Using NIH 3T3 fibroblasts expressing m1 muscarinic acetylcholine receptors as a model system, we have observed that activation of this transforming G protein-coupled receptors induces the rapid expression of a variety of early responsive genes, including the c-fos protooncogene. One of the c-fos promoter elements, the serum response element (SRE), plays a central regulatory role, and activation of SRE-dependent transcription has been found to be regulated by several proteins, including the serum response factor and the ternary complex factor. With the aid of reporter plasmids for gene expression, we observed here that stimulation of m1 muscarinic acetylcholine receptors potently induced SRE-driven reporter gene activity in NIH 3T3 cells. In these cells, only the Gα12 family of heterotrimeric G protein α subunits strongly induced the SRE, while Gβ1γ2 dimers activated SRE to a more limited extent. Furthermore, our study provides strong evidence that m1, Gα12 and the small GTP-binding protein RhoA are components of a novel signal transduction pathway that leads to the ternary complex factor-independent transcriptional activation of the SRE and to cellular transformation.
Resumo:
This manuscript is based on a PhD thesis submitted at the Institute of Social Anthropology at the University of Bern in 2014. The dissertation was part of the research project „Xinjiang Uyghur Autonomous Region and Chinese Territoriality. The Development of Infrastructure and Han Migration into the Region“ under the supervision of Prof. Dr. Heinzpeter Znoj and financed by the Swiss National Science Foundation SNSF. Madlen Kobi analyzes the architectural and socio-political transformation of public places and spaces in rapidly urbanizing southern Xinjiang, P.R. China, and in doing so pays particular attention to the cities of Aksu and Kaxgar. As the Xinjiang Uyghur Autonomous Region lies in between China and Central Asia, it is especially characterized by differing political, cultural, and religious influences, and, furthermore, due to its being a multiethnic region, by multiple identities. One might expect cultural and social identities in this area to be negotiated by referring to history, religion, or food. However, they also become visible by the construction and reconstruction, if not demolition, of public places, architectural landmarks, and private residences. Based on ethnographic fieldwork performed in 2011 and 2012, the study explores everyday life in a continuously transforming urban environment shaped by the interaction of the interests of government institutions, investment companies, the middle class, and migrant workers, among many other actors. Here, urban planning, modernization, and renewal form a highly sensitive lens through which the author inspects the tense dynamics of ethnic, religious, and class-based affiliations. She respects varieties and complexities while thoroughly grounding unfolding transformation processes in everyday lived experiences. The study provides vivid insights into how urban places and spaces in this western border region of China are constructed, created, and eventually contested.
Resumo:
A significant problem with currently suggested approaches for transforming between models in different languages is that the transformation is often described imprecisely, with the result that the overall transformation task may be imprecise, incomplete and inconsistent. This paper presents a formal metamodeling approach for transforming between UML and Object-Z. In the paper, the two languages are defined in terms of their formal metamodels, and a systematic transformation between the models is provided at the meta-level in terms of formal mapping functions. As a consequence, we can provide a precise, consistent and complete transformation between them.
Resumo:
Building Team-based Working is designed for use by managers and consultants who are introducing team-based working into organizations. The book synthesizes knowledge about how to build team-based organizations, focusing particularly on the psychological and social processes that can facilitate or obstruct successful teamwork. Rather than advise managers on how to build effective teams, as most books in this area tend to do, this book instead focuses on how to build organizations structured around teams. The text is divided into six sections describing the six main stages of developing team-based working in an organization. The chapters follow a common structure. Each one opens with a summary of the aims and activities relevant to that stage and concludes with a selection of appropriate support materials and tools. These materials can also be downloaded from the CD accompanying the text. The advice given is based on evidence gathered by the authors over 20 years of practical management experience, research work in organizations, and consultancy across the public, manufacturing and service sectors.
Resumo:
This thesis starts with a literature review, outlining the major issues identified in the literature concerning virtual manufacturing enterprise (VME) transformation. Then it details the research methodology used – a systematic approach for empirical research. next, based on the conceptual framework proposed, this thesis builds three modules to form a reference model, with the purpose of clarifying the important issues relevant to transforming a traditional manufacturing company into a VME. The first module proposes a mechanism of VME transformation – operating along the VME metabolism. The second module builds a management function within a VME to ensure a proper operation of the mechanism. This function helps identify six areas as closely related to VME transformation: lean manufacturing; competency protection; internal operation performance measurement; alliance performance measurement; knowledge management; alliance decision making. The third module continues and proposes an alliance performance measurement system which includes 14 categories of performance indicators. An analysis template for alliance decision making is also proposed and integrated into the first module. To validate these three modules, 7 manufacturing organisations (5 in China and 2 in the UK) were investigated, and these field case studies are analysed in this thesis. The evidence found in these organisations, together with the evidence collected from the literature, including both researcher views and literature case studies, provide support for triangulation evidence. In addition, this thesis identifies the strength and weakness patterns of the manufacturing companies within the theoretical niche of this research, and clarifies the relationships among some major research areas from the perspective of virtual manufacturing. Finally, the research findings are summarised, as well as their theoretical and practical implications. Research limitations and recommendations for future work conclude this thesis.
Resumo:
A comparison has been made between the spectroscopic properties of the laser dye rhodamine 6G (R6G) in mesostructured titanium dioxide (TiO2) and in ethanol. Steady-state excitation and emission techniques have been used to probe the dye-matrix interactions. We show that the TiO2-nanocomposite studied is a good host for R6G, as it allows high dye concentrations, while keeping dye molecules isolated, and preventing aggregation. Our findings have important implications in the context of solid state dye-lasers and microphotonic device applications. (C) 2003 Elsevier B.V. All rights reserved.