The postpneumonectomy syndrome: clinical presentation and treatment

Background: Postpneumonectomy syndrome (PPS) is a rare complication after pneumonectomy. It consists of an excessive mediastinal shift resulting in compression and stretching of the tracheobronchial tree and the esophagus. The aim of this study was to give a comprehensive overview of diagnosis, variety of symptoms and evaluation of surgical treatment of PPS. Methods: We retrospectively reviewed the charts of all our patients with PPS since 1994 with respect to symptomatology, treatment and outcome. Our results were compared with case reports and case series in the literature. Results: Six women with a median age of 56.5 years (range 49-65) developed PPS after pneumonectomy for the treatment of lung cancer. Four presented with a right PPS and two with a left PPS, respectively. Symptoms consisted of shortness of breath in all patients and dysphagia as well as heartburn in two patients. Correction of PPS required re-exploration of the pneumonectomy space, reposition of the mediastinum followed by the insertion of single silicone prosthesis in five patients or fixation of the mediastinum with a xenopericardial graft in one patient. We could observe an improvement of the FEV(1)/FVC ratio in all our patients and the clinical improvement of shortness of breath was better than we expected by changes of lung function. Four patients returned to their regular activities with a follow-up of four years. We found 73 cases of PPS in the literature, on the right side in 50 patients (68%) and on the left side in 23 patients (32%). Fifty-nine patients (81%) were treated surgically. Symptoms can be suspicious for cardiogenic origin and vary from heartburn to recurrent syncopes. Conclusion: PPS is rare and not predictable. It can occur after right or left pneumonectomy. Symptoms are manifold and result from a shift, leading to compression and stretching of the two conduits located within the mediastinum, the tracheobronchial tree and the esophagus and consists of shortness of breath, stridor and heartburn. Diagnosis must be made by exclusion. Implantation of prosthesis is the most commonly used and effective treatmen

Influence of wettability on constitutive relations and its role in upscaling

The lattice Boltzmann (LB) method is applied to simulating multifluid flow in porous media at sub-pore resolution to determine constitutive behaviors. The authors address the importance of the LB technique for identifying process based constitutive relationships, and demonstrate its application through analysis of the influence of wettability on interfacial areas and constitutive relationships. Porous media surface wettability is varied from uniformly strongly wetted by the resident fluid through strongly wetted by the displacing fluid. Spatially variable wettability is also demonstrated. Primary imbibition and drainage displacements are run, and interfacial areas (IFA) as a function of time are determined and compared. Results indicate that wettability is an important factor in displacement behavior and resulting interfacial area. Primary imbibition in a strongly wet material under capillary dominated flows produces film flow, resulting in high IFAs that decrease with increasing saturation and viscous forces. Primary drainage produces initially high IFA that decreases slightly with increasing saturation or pressure drop. Surfaces with spatially variable wetting can have a strong influence on resulting fluid distributions and fluid flow

Pore level imaging of fluid transport using synchrotron x-ray microtomography

Recently developed high resolution computed microtomography (CMI) using synchrotron X-ray sources is analogous to conventional medical Cr scanning and provides the ability to obtain three-dimensional images of specimens with a spatial resolution on the order of micrometers. Application of this technique to the study of core samples has previously been shown to provide excellent two- and three-dimensional high resolution descriptions of pore structure and mineral distributions of core material. Recently, computed microtomographic endpoint saturation images of a fluid filled sandstone core sample were obtained using a microtomographic apparatus and a high energy X-ray beam produced by a superconducting wiggler at the National Synchrotron Light Source at Brookhaven National Laboratory. Images of a 6 mm subsection of the one inch diameter core sample were obtained prior and subsequent to flooding to residual oil. Both oil and brine phases were observable within the imaged rock matrix. The rock matrix image data was used as input to a fluid transport simulator and the results compared with the end point saturation images and data. These high resolution images of the fluid filled pore space have not been previously available to researchers and will provide valuable insight to fluid flow, and provide data as input into and validation of high resolution porous media flow simulators, such as percolation-network and Lattice Boltzmann models

The protein import apparatus of chloroplasts

Routing of cytosolically synthesized precursor proteins into chloroplasts is a specific process which involves a multitude of soluble and membrane components. In this review we wil1 focus on early events of the translocation pathway of nuclear coded plastidic precursor proteins and compare import routes for polypeptide of the outer chloroplast envelope to that of internal chloroplast compartments. A number of proteins housed in the chloroplast envelopes have been implied to be involved in the translocation process, but so far a certain function has not been assigned to any of these proteins. The only exception could be an envelope localized hsc 70 homologue which could retain the import competence of a precursor protein in transit into the organelle

Developing the R&D 100 award-winning lattice Boltzmann permeameter toward a marketable product

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Computational models of oil, gas, and water flow through porous reservoir rock are used in reservoir management to decide whether or not, and how, to develop and produce hydrocarbon reserves. The flow models have major impact on these decisions so their accuracy, cost, and speed is paramount. The accuracy of the flow models is strongly dependent on the accuracy of the physical characterization of the reservoir rock`s pore-fluid system. System characterization is typically done in the laboratory. As an alternative, we have developed a numerical approach for determining the constitutive information. The project sought to use computational techniques that could incorporate all of the basic physical processes that influence fluid movement through the porous rock yet remain computationally efficient. The lattice Boltzmann (LB) numerical technique fits these requirements, and is able to incorporate complex pore geometries exactly and reproduce behavior of multiple fluids. The flexibility of the LB approach allows the numerical model, called the lattice Boltzmann Permeameter (LBP), to determine constitutive relationships (i.e., relative permeabilities) over a much wider range of conditions than can be achieved in a laboratory. Our project was directed toward improving the LBP to make it available to a wide range of users. Improvements were made in computational speed and efficiency, user interfaces, and visualization capabilities

Medical competence, anatomy and the polity in seventeenth-century Rome

At the centre of this article are two physicians active in Rome between 1600 and 1630 who combined medical practice with broader involvement in the dynamic cultural, economic and political scene of the centre of the Catholic world. The city's distinctive and very influential social landscape magnified issues of career-building and allows us to recapture physicians’ different strategies of self-fashioning at a time of major social and religious reorganization. At one level, reconstructing Johannes Faber and Giulio Mancini's medical education, arrival in Rome and overlapping but different career trajectories contributes to research on physicians’ identity in early modern Italian states. Most remarkable are their access to different segments of Roman society, including a dynamic art market, and their diplomatic and political role, claimed as well as real. But following these physicians from hospitals to courts, including that of the Pope, and from tribunals to the university and analysing the wide range of their writing – from medico-legal consilia to political essays and reports of anatomical investigations – also enriches our view of medical practice, which included, but went beyond, the bedside. Furthermore, their activities demand that we reassess the complex place of anatomical investigations in a courtly society, and start recovering the fundamental role played by hospitals – those quintessential Catholic institutions – as sites of routine dissections for both medical teaching and research. (pp. 551–567

Tec1 Mediates the Pheromone Response of the White Phenotype of Candida albicans: Insights into the Evolution of New Signal Transduction Pathways

The newly evolved pheromone response pathway of the white cell phenotype of the opportunistic human pathogen Candida albicans provides a unique view of how signal transduction pathways evolve

Dialectics and difference: against Harvey's dialectical post-Marxism

David Harvey`s recent book, Justice, nature and the geography of difference (JNGD), engages with a central philosophical debate that continues to dominate human geography: the tension between the radical Marxist project of recent decades and the apparently disempowering relativism and `play of difference' of postmodern thought. In this book, Harvey continues to argue for a revised `post-Marxist' approach in human geography which remains based on Hegelian-Marxian principles of dialectical thought. This article develops a critique of that stance, drawing on the work of Jacques Derrida, Gilles Deleuze and Felix Guattari. I argue that dialectical thinking, as well as Harvey's version of `post-Marxism', has been undermined by the wide-ranging `post-' critique. I suggest that Harvey has failed to appreciate the full force of this critique and the implications it has for `post-Marxist' ontology and epistemology. I argue that `post-Marxism', along with much contemporary human geography, is constrained by an inflexible ontology which excessively prioritizes space in the theory produced, and which implements inflexible concepts. Instead, using the insights of several `post-' writers, I contend there is a need to develop an ontology of `context' leading to the production of `contextual theories'. Such theories utilize flexible concepts in a multilayered understanding of ontology and epistemology. I compare how an approach which produces a `contextual theory' might lead to more politically empowering theory than `post-Marxism' with reference to one of Harvey's case studies in JNGD

How to Decrease the Amortization Bias: Experience vs. Rules

We conduct an experimental study that tests the effectiveness of de-biasing a certain form of exponential growth bias found in household finance debt decisions, called the amortization bias. We provide 251 bachelor students at a German university with a short tutorial based on one of three learning methods: experiential learning, learning a simple “I Owe More” debt rule-of-thumb, as well as learning an extended, but more accurate version of the “I Owe More” debt rule. Immediately after completing these tutorials, we retest for the amortization bias and find a significant bias improvement in all three treatments. More importantly, after confronting the same participants with similar debt scenarios approximately three weeks later, we find that those who had previously received a debt tutorial maintain a significantly larger bias improvement over the control group. However, during this short period, most of the individuals who learned the simple and complex rules-of-thumb could no longer apply the rule and reverted back to their biased answers, while the experiential learning group best retained their improvement in bias. We find evidence in this experiment that experience-based learning may be better suited to produce long-lasting improvements for attenuating the amortization bias