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Outer membrane protein (OMP) biogenesis in gram-negative bacteria is managed by a network of periplasmic chaperones that includes SurA, Skp, and FkpA. These chaperones bind unfolded OMPs (uOMPs) in dynamic conformational ensembles to suppress uOMP aggregation, facilitate diffusion across the periplasm, and enhance OMP folding. FkpA primarily responds to heat-shock stress, but its mechanism is comparatively understudied. To determine FkpA chaperone function, we monitored the folding of a cognate client uOmpA171and found that FkpA increases the folded uOmpA171population but also slows the folding rate, dual functions distinct from the other periplasmic chaperones. The results indicate that FkpA behaves as a chaperone and not as a folding catalyst to directly influence the uOmpA171folding trajectory. We determine the binding affinity between FkpA and uOmpA171by globally fitting sedimentation velocity titrations and found it to be intermediate between the known affinities of Skp and SurA for uOMP clients. Notably, complex formation steeply depends on the urea concentration, suggestive of an extensive binding interface. Initial characterizations of the complex using photo-crosslinking indicates that the binding interface spans the inner surfaces of the entire FkpA molecule. In contrast to prior findings, folding and binding experiments performed using subdomain constructs of FkpA demonstrate that the full-length chaperone is required for full activity. Together these results support that FkpA has a distinct and direct effect on uOMP folding and that it achieves this by utilizing an extensive chaperone-client interface.SignificanceThe periplasmic chaperone network is required for the survival and virulence of gram-negative bacteria. Here we find that the chaperone FkpA enhances outer membrane protein folding and tightly binds its clients with an extensive interaction interface. This modified holdase function of FkpA distinguishes it from other periplasmic chaperones and complements their functions to ensure robust outer membrane biogenesis.

In 2016, in anticipation of the US presidential election and forthcoming new administration, the National Academy of Medicine launched a strategic initiative to marshal expert guidance on pressing health and health care priorities. Published as Vital Directions for Health and Health Care, the products of the initiative provide trusted, nonpartisan, evidence-based analysis of critical issues in health, health care, and biomedical science. The current collection of articles published in Health Affairs builds on the initial Vital Directions series by addressing a set of issues that have a particularly compelling need for attention from the next administration: health costs and financing, early childhood and maternal health, mental health and addiction, better health and health care for older adults, and infectious disease threats. The articles also reflect the current experience with both the coronavirus disease 2019 (COVID-19) pandemic and the health inequities that have been drawn out sharply by COVID-19, as well as the implications going forward for action.

Through the insertion of nonpolar side chains into the bilayer, the hydrophobic effect has long been accepted as a driving force for membrane protein folding. However, how the changing chemical composition of the bilayer affects the magnitude side chain transfer free energieshas historically not been well understood. A particularly challenging region for experimental interrogation is the bilayer interfacial region that is characterized by a steep polarity gradient. In this study we have determined thefor nonpolar side chains as a function of bilayer position using a combination of experiment and simulation. We discovered an empirical correlation between the surface area of nonpolar side chain, the transfer free energies, and the local water concentration in the membrane that allows forto be accurately estimated at any location in the bilayer. Using these water-to-bilayervalues, we calculated the interface-to-bilayer transfer free energy. We find that theare similar to the “biological”, translocon-based transfer free energies, indicating that the translocon energetically mimics the bilayer interface. Together these findings can be applied to increase the accuracy of computational workflows used to identify and design membrane proteins, as well as bring greater insight into our understanding of how disease-causing mutations affect membrane protein folding and function.

The periplasmic chaperone network ensures the biogenesis of bacterial outer membrane proteins (OMPs) and has recently been identified as a promising target for antibiotics. SurA is the most important member of this network, both due to its genetic interaction with the β-barrel assembly machinery complex as well as its ability to prevent unfolded OMP (uOMP) aggregation. Using only binding energy, the mechanism by which SurA carries out these two functions is not well-understood. Here, we use a combination of photo-crosslinking, mass spectrometry, solution scattering, and molecular modeling techniques to elucidate the key structural features that define how SurA solubilizes uOMPs. Our experimental data support a model in which SurA binds uOMPs in a groove formed between the core and P1 domains. This binding event results in a drastic expansion of the rest of the uOMP, which has many biological implications. Using these experimental data as restraints, we adopted an integrative modeling approach to create a sparse ensemble of models of a SurA•uOMP complex. We validated key structural features of the SurA•uOMP ensemble using independent scattering and chemical crosslinking data. Our data suggest that SurA utilizes three distinct binding modes to interact with uOMPs and that more than one SurA can bind a uOMP at a time. This work demonstrates that SurA operates in a distinct fashion compared to other chaperones in the OMP biogenesis network.

SurA is thought to be the most important periplasmic chaperone for outer membrane protein biogenesis. Its structure is composed of a core region and two peptidylprolyl isomerase domains, termed P1 and P2, connected by flexible linkers. As such these three independent folding units are able to adopt a number of distinct spatial positions with respect to each other. The conformational dynamics of these domains are thought to be functionally important yet are largely unresolved. Here we address this question of the conformational ensemble using sedimentation equilibrium, small angle neutron scattering and folding titrations. This combination of orthogonal methods converges on a SurA population that is monomeric at physiological concentrations. The conformation that dominates this population has the P1 and core domains docked to one another, e.g. "P1-closed" and the P2 domain extended in solution. We discovered that the distribution of domain orientations is defined by modest and favorable interactions between the core domain and either the P1 or the P2 domains. These two peptidylprolyl domains compete with each other for core-binding but are thermodynamically uncoupled. This arrangement implies two novel insights. Firstly, an open conformation must exist to facilitate P1 and P2 exchange on the core, indicating that the open client-binding conformation is populated at low levels even in the absence of client uOMPs. Secondly, competition between P1 and P2 binding paradoxically occludes the client binding site on the core, which may serve to preserve the reservoir of binding-competent apo-SurA in the periplasm. This article is protected by copyright. All rights reserved.

While the market of smart technologies is steadily increasing, there is much research to be done regarding the interaction between human users and Artificial Intelligence (AI) technologies. Specifically, the field of Explainable Artificial Intelligence (XAI) focuses on making AI explainable to users. To provide a user-centered approach to this growing field, this paper describes a study to investigate possible processes and methods. For this purpose, 20 participants were asked to use an AI system that provided them with the results of a personalized COVID-19 risk calculation. The study results indicate that while participants generally seemed to think that the presented results of the system were accurate, only a few said that they would change their behavior after receiving the results, and many asked for additional information to better understand the results. This paper discusses the findings along with possible approaches to increase behavior change in users of smart systems.

Building a barrel Computational design offers the possibility of making proteins with customized structures and functions. The range of accessible protein scaffolds has expanded with the design of increasingly complex cytoplasmic proteins and, recently, helical membrane proteins. Vorobieva et al. describe the successful computational design of eight-stranded transmembrane β-barrel proteins (TMBs). Using an iterative approach, they show the importance of negative design to prevent off-target structures and gain insight into the sequence determinants of TMB folding. Twenty-three designs satisfied biochemical screens for a TMB structure, and two structures were experimentally validated by nuclear magnetic resonance spectroscopy or x-ray crystallography. This is a step toward the custom design of pores for applications such as single-molecule sequencing. Science , this issue p. eabc8182

The thermodynamic stabilities of membrane proteins are of fundamental interest to provide a biophysical description of their structure-function relationships because energy determines conformational populations. In addition, structure-energy relationships can be exploited in membrane protein design and in synthetic biology. To determine the thermodynamic stability of a membrane protein, it is not sufficient to be able to unfold and refold the molecule: establishing path independence of this reaction is essential. Here we describe the procedures required to measure and verify path independence for the folding of outer membrane proteins in large unilamellar vesicles.

In 2016, in anticipation of the US presidential election and forthcoming new administration, the National Academy of Medicine launched a strategic initiative to marshal expert guidance on pressing health and health care priorities. Published as Vital Directions for Health and Health Care, the products of the initiative provide trusted, nonpartisan, evidence-based analysis of critical issues in health, health care, and biomedical science. The current collection of articles published in

Membrane proteins have historically been recalcitrant to biophysical folding studies. However, recent adaptations of methods from the soluble protein folding field have found success in their applications to transmembrane proteins composed of both α-helical and β-barrel conformations. Avoiding aggregation is critical for the success of these experiments. Altogether these studies are leading to discoveries of folding trajectories, foundational stabilizing forces and better-defined endpoints that enable more accurate interpretation of thermodynamic data. Increased information on membrane protein folding in the cell shows that the emerging biophysical principles are largely recapitulated even in the complex biological environment.

The ability of naturally occurring transmembrane β-barrel proteins (TMBs) to spontaneously insert into lipid bilayers and form stable transmembrane pores is a remarkable feat of protein evolution and has been exploited in biotechnology for applications ranging from single molecule DNA and protein sequencing to biomimetic filtration membranes. Because it has not been possible to design TMBs from first principles, these efforts have relied on re-engineering of naturally occurring TMBs that generally have a biological function very different from that desired. Here we leverage the power of de novo computational design coupled with a “hypothesis, design and test” approach to determine principles underlying TMB structure and folding, and find that, unlike almost all other classes of protein, locally destabilizing sequences in both the β-turns and β-strands facilitate TMB expression and global folding by modulating the kinetics of folding and the competition between soluble misfolding and proper folding into the lipid bilayer. We use these principles to design new eight stranded TMBs with sequences unrelated to any known TMB and show that they insert and fold into detergent micelles and synthetic lipid membranes. The designed proteins fold more rapidly and reversibly in lipid membranes than the TMB domain of the model native protein OmpA, and high resolution NMR and X-ray crystal structures of one of the designs are very close to the computational model. The ability to design TMBs from first principles opens the door to custom design of TMBs for biotechnology and demonstrates the value of de novo design to investigate basic protein folding problems that are otherwise hidden by evolutionary history.One sentence summarySuccess in de novo design of transmembrane β-barrels reveals geometric and sequence constraints on the fold and paves the way to design of custom pores for sequencing and other single-molecule analytical applications.

Hematopoietic stem cell transplantation is successfully applied since the late 1950s; however, its efficacy still needs to be increased. A promising strategy is to transplant high numbers of pluripotent hematopoietic stem cells (HSCs). Therefore, an improved ex vivo culture system that supports proliferation and maintains HSC pluripotency would override possible limitations in cell numbers gained from donors. To model the natural HSC niche in vitro, we optimized the HSC medium composition with a panel of cytokines and valproic acid and used an artificial 3D bone marrow-like scaffold made of polydimethylsiloxane (PDMS). This 3D scaffold offered a suitable platform to amplify human HSCs in vitro and, simultaneously, to support their viability, multipotency and ability for self-renewal. Silicon oxide-covering of PDMS structures further improved amplification of CD34+ cells, although the conservation of naïve HSCs was better on non-covered 3D PDMS. Finally, we found that HSC cultivated on non-covered 3D PDMS generated most pluripotent colonies within colony forming unit assays. In conclusion, by combining biological and biotechnological approaches, we optimized in vitro HSCs culture conditions, resulting in improved amplification, multipotency maintenance and vitality of HSCs.

The thermodynamic stabilities of membrane proteins are of fundamental interest to provide a biophysical description of their structure-function relationships because energy determines conformational populations. In addition, structure-energy relationships can be exploited in membrane protein design and in synthetic biology. To determine the thermodynamic stability of a membrane protein, it is not sufficient to be able to unfold and refold the molecule: establishing path independence of this reaction is essential. Here we describe the procedures required to measure and verify path independence for the folding of outer membrane proteins in large unilamellar vesicles.

Trendanalyse Intergeo 2018

In this article, we extend our previous instrument [1], which helps trainees improve the precision of their compressions during Cardio-Pulmonary Resuscitation (CPR), by adding to it a 3D-printed component (http://acima.lncc. br/i&m) that further improves the precision of force angle measurements. Our instrument measures the force vector and frequency of CPR compressions performed by the trainee. CPR is a technique that allows a certified person to try to keep alive someone whose heartbeat and/or breathing has stopped. Through compressions applied to the thorax of the individual in need of help, one can maintain the blood flow and air intake until further help (and equipment) arrives. During CPR training, our 3D-prototype methodically attaches a standard CPR manikin to a Nintendo WiiTM Balance Board, enabling adequate balance of the instrument, and thus, obtaining more precise data out of the compressions performed. Results of our empirical evaluations show that with the 3D prototype, the measured parameters of force value, force direction and frequency have a standard uncertainty of 0.91 KgF, 0.25 Rad (14.35 degrees), and 0.15 Hz, respectively, while without our 3D prototype they have a standard uncertainty of 0.72 KgF, 0.44 Rad (25.25 degrees) and 0.12 Hz, respectively. Results prove that our 3D prototype contributes to increasing the precision of force angle measurement, since it holds the manikin firmly in place, while having negligible effect in force amount and frequency measurements.

To evaluate the effects of HIFU therapy on visceral vessel patency in patients with inoperable locally invasive pancreatic cancer. 50 pancreatic cancer patients (26 men, 24 women) aged 41 - 82 years (65.0 ± 10.2) underwent ultrasonography (US) and computed tomography (CT) examinations before and within one day after HIFU treatment, as well as at follow-up at six weeks, three months and six months. Evaluation and grading were performed by two experienced independent radiologists according to a classification scheme based on vessel involvement, vessel diameter, patency, and defects in flow. Before HIFU treatment, arterial vessel involvement was noted in 42 patients, venous involvement in 47, and 47 patients presented with both. Superior mesenteric artery occlusion was found in three carcinomas while nearly half of the cases (n = 24) displayed signs of superior mesenteric vein, portal vein, or splenic vein occlusion. High-grade tumor-associated arterial narrowing was seen in ten patients. Despite vessel encasement and partially extensive propagation of collateral vessels, it was possible to safely perform HIFU treatment in all patients without complications. US and CT studies performed within one day after therapy did not show any change in vessel patency in 47 patients (94 %). Follow-up controls at the six-week mark revealed increased vessel narrowing and finally occlusion after six months in 11 patients due to tumor progression. This study demonstrates that HIFU treatment can be safely applied to pancreatic cancers enveloping large mesenteric vessels despite vessel narrowing or extensive collateral propagation. Most patients (94 %) did not experience adverse effects regarding vessel patency.ZIEL: Analyse der Auswirkungen der US-gesteuerten HIFU-Therapie auf die großen Oberbauchgefäße bei Patienten mit inoperablem Pankreaskarzinom. Beurteilung der sonografischen und computertomografischen Untersuchungen von 50 konsekutiv mit HIFU behandelten Patienten (26 Männer und 24 Frauen) zwischen 41 und 82 (65,0 ± 10,2) Jahren vor und unmittelbar nach der HIFU-Therapie sowie nach 6 Wochen, 3 und 6 Monaten. Die Auswertung erfolgte durch zwei unabhängige Untersucher aufgeschlüsselt nach Gefäßen und Grad der Gefäßbeteiligung (0 = keine Gefäßbeteiligung, 1 = Tumor reicht an das Gefäß heran, keine Einengung, 2 = mäßige Gefäßeinengung, 3 = filiforme Gefäßeinengung, 4 = Gefäßverschluss). Vor HIFU-Therapie lag bei 42 der Patienten eine Beteiligung der arteriellen, bei 47 Patienten der venösen Gefäße und 47 Patienten von beiden vor. Dabei wiesen 10 Patienten eine tumorbedingte filiforme arterielle Gefäßeinengung, drei einen Verschluss der A. mesenterica sup., nahezu die Hälfte (n = 24) einen Verschluss von V. mesenterica sup., Pfortader oder Milzvene auf. Trotz dieser Gefäßummauerung und der zum Teil massiv erkennbaren Kollateralgefäße konnte eine HIFU-Therapie bei allen Patienten klinisch komplikationslos durchgeführt werden. Die Kontrollen unmittelbar nach durchgeführter HIFU-Behandlung zeigten bei 47 der Patienten (94 %) keine Änderung des Gefäßstatus. Durch Tumorprogress kam es bei 11 Patienten zu einer zunehmenden Gefäßeinengung ab der sechsten Woche bis hin zum Verschluss nach 6 Monaten. Eine HIFU-Ablation beim lokal fortgeschrittenen Pankreaskarzinom ist auch bei mesenterialer Gefäßbeteiligung und ausgeprägten Umgehungskreisläufen sicher möglich. Bei den meisten Patienten (94 %) hat die Therapie trotz z. T. hochgradiger Stenosen keine nachteilige Auswirkung auf die Gefäßsituation.

Neuronal voltage-gated sodium channel Na(V)1.2 C-terminal domain (CTD) binds calmodulin (CaM) constitu-tively at its IQ motif. A solution structure (6BUT) and other NMR evidence showed that the CaM N domain (CaM(N)) is structurally independent of the C-domain (CaM(C)) whether CaM is bound to the Na(V)1.2(IQp) (1,901–1,927) or Na(V)1.2(CTD) (1,777–1,937) with or without calcium. However, in the CaM + Na(V)1.2(CTD) complex, the Ca(2+) affinity of CaM(N) was more favorable than in free CaM, while Ca(2+) affinity for CaM(C) was weaker than in the CaM + Na(V)1.2(IQp) complex. The CTD EF-like (EFL) domain allosterically widened the energetic gap be-tween CaM domains. Cardiomyopathy-associated CaM mutants (N53I(N54I), D95V(D96V), A102V(A103V), E104A(E105A), D129G(D130G), and F141L(F142L)) all bound the Na(V)1.2 IQ motif favorably under resting (apo) conditions and bound calcium normally at CaM(N) sites. However, only N53I and A102V bound calcium at CaM(C) sites at [Ca(2+)] < 100 μM. Thus, they are expected to respond like wild-type CaM to Ca(2+) spikes in excitable cells.

Purpose: To develop and evaluate an automated segmentation method for accurate quantification of abdominal adipose tissue (AAT) depots (superficial subcutaneous adipose tissue [SSAT], deep subcutaneous adipose tissue [DSAT], and visceral adipose tissue [VAT]) in neonates and young children. Materials and Methods: This was a secondary analysis of prospectively collected data, which used abdominal MRI data from Growing Up in Singapore Towards healthy Outcomes, or GUSTO, a longitudinal mother–offspring cohort, to train and evaluate a convolutional neural network for volumetric AAT segmentation. The data comprised imaging volumes of 333 neonates obtained at early infancy (age 2 weeks, 180 male neonates) and 755 children aged either 4.5 years (n = 316, 150 male children) or 6 years (n = 439, 219 male children). The network was trained on images of 761 randomly selected volumes (neonates and children combined) and evaluated on 100 neonatal volumes and 227 child volumes by using 10-fold validation. Automated segmentations were compared with expert-generated manual segmentation. Segmentation performance was assessed using Dice scores. Results: When the model was tested on the test datasets across the 10 folds, the model had strong agreement with the ground truth for all testing sets, with mean Dice similarity scores for SSAT, DSAT, and VAT, respectively, of 0.960, 0.909, and 0.872 in neonates and 0.944, 0.851, and 0.960 in children. The model generalized well to different body sizes and ages and to all abdominal levels. Conclusion: The proposed segmentation approach provided accurate automated volumetric assessment of AAT compartments on MR images of neonates and children. Agency for Science, Technology and Research (A*STAR) Ministry of Health (MOH) National Medical Research Council (NMRC) Supported in part by the Singapore National Research Foundation under its Translational and Clinical Research (TCR) Flagship Programme and administered by the Singapore Ministry of Health National Medical Research Council, Singapore (NMRC/TCR/004-NUS/2008; NMRC/TCR/012-NUHS/2014). Additional funding is provided by the Singapore Institute for Clinical Sciences, Agency for Science Technology and Research, Singapore.

For an adjustment of a similarity transformation, it is often appropriate to consider that both the source and the target coordinates of the transformation are affected by errors. For the least squares adjustment of this problem, a direct solution is possible in the cases of specific-weighing schemas of the coordinates. Such a problem is considered in the present contribution and a direct solution is generally derived for the m-dimensional space. The applied weighing schema allows (fully populated) point-wise weight matrices for the source and target coordinates, both weight matrices have to be proportional to each other. Additionally, the solutions of two borderline cases of this weighting schema are derived, which only consider errors in the source or target coordinates. The investigated solution of the rotation matrix of the adjustment is independent of the scaling between the weight matrices of the source and the target coordinates. The mentioned borderline cases, therefore, have the same solution of the rotation matrix. The direct solution method is successfully tested on an example of a 3D similarity transformation using a comparison with an iterative solution based on the Gauß-Helmert model.

Background The Intercollegiate Membership of the Royal College of Surgeons (MRCS) examination is undertaken by large numbers of trainees in the UK and internationally as a mandatory step within surgical training. Unlike some high-stakes medical examinations, the MRCS is yet to be validated. A quantitative study was undertaken to assess its predictive validity by investigating the relationship between MRCS (Parts A and B) and national selection interview scores for general and vascular surgery in the UK. Methods Pearson correlation coefficients were used to examine the linear relationship between each assessment, and linear regression analyses were employed to identify potential independent predictors of the national selection score. All UK medical graduates who attempted the interview in 2011–2015 were included. Results Some 84·4 per cent of the candidates (1231 of 1458) were matched with MRCS data. There was a significant positive correlation between the first attempt score at Part B of the MRCS examination and the national selection score (r = 0·38, P

Background The Intercollegiate Membership of the Royal College of Surgeons (MRCS) examination is undertaken by large numbers of trainees in the UK and internationally as a mandatory step within surgical training. Unlike some high‐stakes medical examinations, the MRCS is yet to be validated. A quantitative study was undertaken to assess its predictive validity by investigating the relationship between MRCS (Parts A and B) and national selection interview scores for general and vascular surgery in the UK. Methods Pearson correlation coefficients were used to examine the linear relationship between each assessment, and linear regression analyses were employed to identify potential independent predictors of the national selection score. All UK medical graduates who attempted the interview in 2011–2015 were included. Results Some 84·4 per cent of the candidates (1231 of 1458) were matched with MRCS data. There was a significant positive correlation between the first attempt score at Part B of the MRCS examination and the national selection score (r = 0·38, P

Several members of the voltage-gated sodium channel family are regulated by calmodulin (CaM) and ionic calcium. The neuronal voltage-gated sodium channel NaV1.2 contains binding sites for both apo (calcium-depleted) and calcium-saturated CaM. We have determined equilibrium dissociation constants for rat NaV1.2 IQ motif [IQRAYRRYLLK] binding to apo CaM (~3nM) and (Ca2+)4-CaM (~85nM), showing that apo CaM binding is favored by 30-fold. For both apo and (Ca2+)4-CaM, NMR demonstrated that NaV1.2 IQ motif peptide (NaV1.2IQp) exclusively made contacts with C-domain residues of CaM (CaMC). To understand how calcium triggers conformational change at the CaM-IQ interface, we determined a solution structure (2M5E.pdb) of (Ca2+)2-CaMC bound to NaV1.2IQp. The polarity of (Ca2+)2-CaMC relative to the IQ motif was opposite to that seen in apo CaMC-Nav1.2IQp (2KXW), revealing that CaMC recognizes nested, anti-parallel sites in Nav1.2IQp. Reversal of CaM may require transient release from the IQ motif during calcium binding, and facilitate a re-orientation of CaMN allowing interactions with non-IQ NaV1.2 residues or auxiliary regulatory proteins interacting in the vicinity of the IQ motif.

Chaperone proteins play a critical role in the biogenesis of many nascent polypeptides in vivo. In the periplasm of E. coli this role is partially fulfilled by SurA, which promotes the efficient assembly of unfolded outer membrane proteins (uOMPs) into the bacterial outer membrane, though the mechanism by which SurA interacts with uOMPs is not well understood. Here we identify multiple conformations of SurA in solution, one of which contains a cradle-like groove in which client uOMPs bind. Access to this binding groove by clients is gated by the intrinsic conformational dynamics of SurA. Crosslinking mass spectrometry experiments identify multiple regions of native client uOMPs that bind to SurA, providing insight into the molecular determinants of SurA-uOMP interactions. In contrast to other periplasmic chaperones that encapsulate uOMPs, small angle neutron scattering data demonstrate that SurA binding greatly expands client uOMPs. These data can explain the dual roles of SurA as both a holdase and a foldase. Using an integrative modeling approach that combines crosslinking, mass spectrometry, small angle neutron scattering, and simulation, we propose structural models of SurA in complex with an unfolded protein client. We further find that multiple SurA monomers are able to bind discrete sites on a single uOMP. The structural arrangement of SurA and uOMPs provides the basis for a possible mechanism by which SurA binds and expands clients in a manner that facilitates their folding into the outer membrane. Significance Statement Outer membrane proteins play critical roles in bacterial physiology and increasingly are being exploited as antibiotic targets. Their biogenesis requires chaperones in the bacterial periplasm to safely ferry them to their destination membrane. We used crosslinking, mass spectrometry, and small angle neutron scattering to propose an ensemble of structural models that explain how one chaperone, SurA, stabilizes client outer membrane proteins through expansion of their overall size, which positions them for delivery to the BAM complex. This study highlights the use of an hybrid integrative approach and emerging methods in structural biology to map highly heterogeneous structural ensembles like that of an unfolded protein bound to a chaperone.

A simple method for modelling steam turbines using a nozzle analogy was recently published. The method describes both stator and rotor components of a turbine with an appropriate nozzle definition, and makes use of the traditional velocity triangles to determine work output. What makes the method convenient is that it only requires a reasonable estimate of the effective nozzle throat area per blade row, as well as properly chosen loss coefficients. A complete turbine train with multiple stages can easily be solved using a simple 1-D pressure correction method. The method was demonstrated to match detailed inter-stage turbine data quite accurately. This paper elaborates on the application of the method. It presents a more thorough procedure for establishing the nozzle throat areas using a turbine lay-out drawing, as well as consideration of possible reaction ratio variation between successive stages. Furthermore, the loss coefficients are determined using the methods described by Traupel and Zehner. The paper presents these in a compressed and digitized format for easy implementation in a software code. A case study is presented to show how the model can quantify improvements to blade profiles. Another case study models a complete boiler feed pump turbine connected to the feedwater pumps and includes the partial arc governing stage and cold re-heat supply. This specific model demonstrated the method’s ability to accurately model a turbine at low load and high back pressure conditions. Turbine system modelers can apply the method presented here to their own equipment and obtain trustworthy results without the need for detailed profile geometry or complex CFD analyses. The method is however limited to subsonic flow between blade rows, hence some modern transonic last stage blade designs might not be adequately represented.

Recently there has been a significant increase in the amount and frequency of seaweed blooms of the holopelagic brown macroalgae Sargassum fluitans and natans (hereafter Sargassum) in the Atlantic Ocean. These blooms impose a major burden on residents (e.g. rotting beached Sargassum, unpleasant odor, toxic gases), the local economy of countries with affected coast lines (e.g. impacting tourism and aquaculture, costs for remediation), and have a significant impact on the environment (e.g. beaches and coastal areas) and local marine wildlife. Here we present a Techno-Economic Analysis to demonstrate how this burden can be turned into an economic, social and environmental asset. The suggested process involves sustainable ship-based harvesting of excess biomass (up to 6.3 MT·year−1) and using hydrothermal liquefaction (HTL) and established fuel refining processes to deliver renewable liquid fuels. Sea-based harvesting of Sargassum addresses the primary cost impediment for algae-based renewable fuel production, reducing capital and operating costs by 78% and 66% respectively compared with currently modelled land-based microalgae renewable fuel production processes. The modelled approach charts a path to cost competitive renewable fuels that reduce CO2 emissions while mitigating the economic, social and environmental problems caused by these large Sargassum algae blooms. The financial analysis of the process yielded an Internal Rate of Return (IRR) between 2.4% and 28.1% based on the scenarios analyzed. The process could generate up to 8500 bbl of crude oil per day profitably at US$43 bbl−1 (10% IRR), equivalent to 470 ML of diesel or jet fuel per year as well as biofertilizers and recycled nutrients, employ around 200 direct personnel and create up to 1000 indirect jobs.

Les tumeurs neuroendocrines bien differentiees (TNE), tumeurs rares et heterogenes, font l’objet d’une prise en charge et d’un suivi difficiles, en particulier du fait d’un manque de biomarqueur pertinent. La neuropiline-2 (NRP2), corecepteur des recepteurs au VEGF, a un role oncogenique demontre et est surexprimee dans les TNE comme dans de nombreux types tumoraux. NRP2 existe sous une forme soluble (NRP2s), dosable sur serum de patient, et suggeree comme biomarqueur dans les cancers bronchiques notamment. L’objectif de cette etude etait d’etudier NRP2s comme biomarqueur des TNE. NRP2s a ete dosee sur serums de patients malades et mis en relation avec les caracteristiques cliniques, morphologiques, biologiques tumorales. A travers une cohorte de 72 patients presentant une TNE pancreatique (15), intestinale (40) ou bronchique (17), nous avons demontre que l’expression de NRP2s etait homogene quel que soit le primitif et significativement plus importante comparee aux temoins sains (1,28 vs 0,43 ng/ml p

Oliver Tambo dedicated most of his life to the liberation of South Africa from apartheid dominion, whereby he garnered international respect from his peers and contemporaries. He rose to prominence within the African National Congress (ANC) during a harrowing time in South Africa’s history by consistently demonstrating leadership and guidance. Tambo’s innate leadership skills originated through his unique mix of personality qualities that he steadfastly believed in his entire life. This tenacity and conviction allowed him to govern the leadership of the ANC—despite being in exile—in an efficient and systematic manner. The objective of this paper is to examine the different leadership traits Tambo possessed, which allowed him to steer his political party’s ship through the most turbulent of seas. Secondly, this paper examines the current political climate in South Africa with the aim of addressing leadership models required to mould and sculpt South African society into the Tambos of today. These two objectives will largely be pursued through oral testimonies of those who worked and interacted with Tambo closely over the years, as well as anecdotal stories which demonstrate the level of leadership Tambo always provided.

Category: Sports Introduction/Purpose: Lateral ankle pain persists in 10%-20% of patients following severe ankle sprains treated non-operatively. The authors hypothesize that the peroneal tendons may become interposed between the ruptured ends of the calcaneofibular ligament (CFL). Though previously visualized and noted in the literature, no studies have evaluated this lesion biomechanically and anatomically. The purpose of this study is to demonstrate that following a severe lateral ankle sprain that the interposition of the peroneal tendons between the ruptured ends of the CFL can occur. Methods: Eight fresh-frozen cadaveric lower extremity specimens (defrosted) were secured by the foot to a wooden board in the method of Lauge-Hansen. A manual inversion force was then applied to the ankle, both with the ankle in plantar flexion and also in a neutral position to approximate a severe ankle sprain. Magnetic resonance imaging (MRI) was then performed on each ankle. Each specimen was then dissected to observe the integrity and relationship of the lateral ankle structures. Results: Four of the eight specimens sustained CFL tears as viewed by MRI and confirmed through anatomic dissection. One of the four specimens with a CFL tear had a mid substance ligament rupture with the proximal half of the ligament positioned superficial to the peroneal tendon complex. This relationship was observed using the MRI. Conclusion: Creating severe lateral ankle sprain produced ruptures of the CFL with interposition of the peroneal tendon complex between the torn ends of the ligament was seen and identified. This phenomenon may prevent primary ligament healing of the CFL and may be a contributing factor in the chronic ankle pain of non-surgically treated lateral ankle sprains. Perhaps surgical intervention should be considered if clinical suspicion exists, such as with a Stener lesion of the hand.

Magnetic resonance (MR) T1 and T2* mapping allows quantification of liver relaxation times for non-invasive characterization of diffuse liver disease. We hypothesized that liver relaxation times are not only influenced by liver fibrosis, inflammation and fat, but also by air in liver segments adjacent to the lung – especially in MR imaging at 3T. A total of 161 study participants were recruited, while 6 patients had to be excluded due to claustrophobia or technically uninterpretable MR elastography. Resulting study population consisted of 12 healthy volunteers and 143 patients who prospectively underwent multiparametric MR imaging at 3T. Of those 143 patients, 79 had normal liver stiffness in MR elastography (shear modulus

Background In daily practice, surgical biopsy of minor salivary glands is routinely performed for the diagnosis of Sjogren’s syndrome. The classification criteria for Sjogren’s syndrome imply specific positive labial salivary gland biopsy findings. Surgical biopsies of the minor labial glands may result in up to 6% of patients in various complications, e.g. numbness of the lower lip. On the other hand, adverse events following core needle biopsies of the parotid gland in non-rheumatological settings were reported as very rare. Even so parotid gland biopsies require a more demanding surgical expertise mainly to protect the facial nerve. Objectives The objective of this study was to assess the feasibility and to determine the presence of parotid gland tissue in minimally invasive ultrasound-guided parotid gland biopsies in cadavers performed by rheumatologists using histology as a gold standard. Methods Two senior rheumatologists obtained under direct ultrasound visualisation in in-plane technique biopsies of 8 parotid glands from 4 different cadavers using a core biopsy needle (core biopsy needle 18G). One biopsy per gland was taken and was subsequently stored. The direction of the bioptic access is shown in Figure 1. The specimen underwent histological examination by an experienced pathologist. Results All histological exams showed typical parotid gland tissue. Notably, no facial nerve tissue or major vessels could be detected in the biopsy material. Conclusions In this cadaveric feasibility study, we demonstrated that minimally invasive ultrasound guided parotid core biopsy is a highly precise and easy method to obtain salivary gland tissue. References [1] Shiboski C. H. et al, 2016American College of Rheumatology/European League Against Rheumatism Classification Criteria for Primary Sjogren’s Syndrome. Arthritis Rheumatol. 2017 Jan;69(1):35–45. [2] Kim H.Jet al, Ultrasound-Guided Core Needle Biopsy in Salivary Glands: A Meta-analysis, Laryngoscope, 00:000–000, 2017. Disclosure of Interest None declared

Objective Increasing numbers of older patients are undergoing surgery. Older surgical patients are at a higher risk of perioperative complications and mortality. Multimorbidity, frailty, and physiological changes of ageing contribute to adverse outcomes. These complications are predominantly medical, rather than directly surgical. Guidelines recommend preoperative assessment of comorbidity, disability, and frailty in older patients undergoing surgery and closer perioperative collaboration between surgeons and geriatricians. We conducted a survey to assess knowledge and beliefs of surgical trainees toward common perioperative problems encountered in older surgical patients. Design Paper-based survey. Setting Unselected UK surgical training-grade physicians (CT1-ST8) attending the 2013 Congress of The Association of Surgeons of Great Britain and Ireland, Glasgow, UK, May 1-3, 2013. Participants A total of 160 eligible UK surgical trainees attending the conference were invited to participate in the survey. Of them, 157 participated. Results Of the trainees, 68% ( n = 107) reported inadequate training and 89.2% ( n = 140) supported the inclusion of geriatric medicine issues in surgical curricula. Of the respondents, 77.2% ( n = 122) were unable to correctly identify the key features required to demonstrate mental capacity, and only 3 of 157 respondents were familiar with the diagnostic criteria for delirium. Support from geriatric medicine was deemed necessary (84.7%, n = 133) but often inadequate (68.2%, n = 107). Surgical trainees support closer collaboration with geriatric medicine and shared care of complex, older patients (93.6%, n = 147). Conclusions UK surgical trainees believe that they receive inadequate training in the perioperative management of complex, older surgical patients and are inadequately supported by geriatric medicine physicians. In this survey sample, trainee knowledge of geriatric issues such as delirium and mental capacity was poor. Surgical trainees support the concept of closer liaison and shared care of complex, older patients with geriatric medicine physicians. Changes to surgical training and service development are needed.