Analysis of left ventricular behaviour in diastole by means of finite element method

The human left ventricle in diastole can be modelled as a passive structure with incremental internal pressure change being considered as the load. Recent developments in engineering stress analysis provide techniques for predicting the behaviour of structures with complex geometry and material properties, as is the case with the left ventricle. That which is most appropriate is the finite element method which requires the use of a large digital computer. The ventricles of 2 patients have been studied during diastole, the geometries having been derived from cineangiographic data (biplane), and the pressure by means of catheter-tip manometers. Various descriptions of myocardial stress/strain relations have been assumed and applied to the left ventricular wall in order to obtain the best match between the calculated and observed deformation patterns. The manner in which the value and distribution of stiffness in the left ventricle influences the shape change can therefore be determined, and possible clinical implications deduced

Relation between intraventricular pressure and volume in diastole

The pressure-volume curves for 10 patients with various types of heart disease were studied throughout mid to late diastole when both pressure and volume were increasing. The results were used to test a currently held theory that the form of this relation is exponential. It was found that for the patients examined this hypothesis was not valid

The Warwick Hip Trauma Evaluation One - an abridged protocol for the WHiTE One Study AN EMBEDDED RANDOMISED TRIAL COMPARING THE X-BOLT WITH SLIDING HIP SCREW FIXATION IN EXTRACAPSULAR HIP FRACTURES

Fractures of the proximal femur are one of the greatest challenges facing the medical community, constituting a heavy socioeconomic burden worldwide. Controversy exists regarding the optimal treatment for patients with unstable trochanteric proximal femoral fractures. The recognised treatment alternatives are extramedullary fixation usually with a sliding hip screw and intramedullary fixation with a cephalomedullary nail. Current evidence suggests that best results and lowest complication rates occur using a sliding hip screw. Complications in these difficult fractures are relatively common regardless of type of treatment. We believe that a novel device, the X-Bolt dynamic plating system, may offer superior fixation over a sliding hip screw with lower reoperation risk and better function. We therefore propose to investigate the clinical effectiveness of the X-bolt dynamic plating system compared with standard sliding hip screw fixation within the framework of a the larger WHiTE (Warwick Hip Trauma Evaluation) Comprehensive Cohort Study. Cite this article: Bone Joint Res 2013;2:206–9

Effect on health-related quality of life of the X-Bolt dynamic plating system versus the sliding hip screw for the fixation of trochanteric fractures of the hip in adults: the WHiTE Four randomized clinical trial

Aims Surgical treatment of hip fracture is challenging; the bone is porotic and fixation failure can be catastrophic. Novel implants are available which may yield superior clinical outcomes. This study compared the clinical effectiveness of the novel X-Bolt Hip System (XHS) with the sliding hip screw (SHS) for the treatment of fragility hip fractures. Methods We conducted a multicentre, superiority, randomized controlled trial. Patients aged 60 years and older with a trochanteric hip fracture were recruited in ten acute UK NHS hospitals. Participants were randomly allocated to fixation of their fracture with XHS or SHS. A total of 1,128 participants were randomized with 564 participants allocated to each group. Participants and outcome assessors were blind to treatment allocation. The primary outcome was the EuroQol five-dimension five-level health status (EQ-5D-5L) utility at four months. The minimum clinically important difference in utility was pre-specified at 0.075. Secondary outcomes were EQ-5D-5L utility at 12 months, mortality, residential status, mobility, revision surgery, and radiological measures. Results Overall, 437 and 443 participants were analyzed in the primary intention-to-treat analysis in XHS and SHS treatment groups respectively. There was a mean difference of 0.029 in adjusted utility index in favour of XHS with no evidence of a difference between treatment groups (95% confidence interval -0.013 to 0.070; p = 0.175). There was no evidence of any differences between treatment groups in any of the secondary outcomes. The pattern and overall risk of adverse events associated with both treatments was similar. Conclusion Any difference in four-month health-related quality of life between the XHS and SHS is small and not clinically important. There was no evidence of a difference in the safety profile of the two treatments; both were associated with lower risks of revision surgery than previously reported

Design and Construction of Multigenic Constructs for Plant Biotechnology Using the GoldenBraid Cloning Strategy

GoldenBraid (GB) is an iterative and standardized DNA assembling system specially designed for Multigene Engineering in Plant Synthetic Biology. GB is based on restriction–ligation reactions using type IIS restriction enzymes. GB comprises a collection of standard DNA pieces named “GB parts” and a set of destination plasmids (pDGBs) that incorporate the multipartite assembly of standardized DNA parts. GB reactions are extremely efficient: two transcriptional units (TUs) can be assembled from several basic GBparts in one T-DNA less than 24 h. Moreover, larger assemblies comprising 4–5 TUs are routinely built in less than 2 working weeks. Here we provide a detailed view of the GB methodology. As a practical example, a Bimolecular Fluorescence Complementation construct comprising four TUs in a 12 kb DNA fragment is presented.Sarrion-Perdigones, A.; Palací, J.; Granell Richart, A.; Orzáez Calatayud, DV. (2014). Design and Construction of Multigenic Constructs for Plant Biotechnology Using the GoldenBraid Cloning Strategy. Methods in Molecular Biology. 1116:133-151. doi:10.1007/978-1-62703-764-8_10S1331511116Haseloff J, Ajioka J (2009) Synthetic biology, history, challenges and prospects. J R Soc Interface 6(Suppl 4):S389–S391Check E (2005) Synthetic biology, designs on life. Nature 438:417–418Kosuri S, Eroshenko N, LeProust EM et al (2010) Scalable gene synthesis by selective amplification of DNA pools from high-fidelity microchips. Nat Biotechnol 28:1295–1299Ellis T, Adie T, Baldwin GS (2011) DNA assembly for synthetic biology, from parts to pathways and beyond. Integr Biol 3:109–118Gibson DG, Young L, Chuang R-Y et al (2009) Enzymatic assembly of DNA molecules up to several hundred kilobases. Nat Methods 6: 343–345Gibson DG, Glass JI, Lartigue C et al (2010) Creation of a bacterial cell controlled by a chemically synthesized genome. Science 329:52–56Sarrion-Perdigones A, Falconi EE, Zandalinas SI et al (2011) GoldenBraid, an iterative cloning system for standardized assembly of reusable genetic modules. PLoS One 6:e21622Sarrion-Perdigones A, Vilar-Vazquez M et al (2013) GoldenBraid2.0, A comprehensive DNA assembly framework for plant synthetic biology. Plant Physiol 162:1618–1631Engler C, Gruetzner R, Kandzia R (2009) Golden gate shuffling, a one-pot DNA shuffling method based on type IIs restriction enzymes. PLoS One 4:e5553Engler C, Kandzia R, Marillonnet S (2008) A one pot, one step, precision cloning method with high throughput capability. PLoS One 3:e3647Bracha-Drori K, Shichrur K, Katz A et al (2004) Detection of protein-protein interactions in plants using bimolecular fluorescence complementation. Plant J 40:419–427Smaczniak C, Immink RG, Muino JM et al (2012) Characterization of MADS-domain transcription factor complexes in Arabidopsis flower development. Proc Natl Acad Sci U S A 109:1560–1565de Folter S, Immink RG, Kieffer M et al (2005) Comprehensive interaction map of the Arabidopsis MADS Box transcription factors. Plant Cell 17:1424–1433Lorenz WW, McCann RO, Longiaru M et al (1991) Isolation and expression of a cDNA encoding Renilla reniformis luciferase. Proc Natl Acad Sci U S A 88:4438–4442Voinnet O, Pinto YM, Baulcombe DC (1999) Suppression of gene silencing: a general strategy used by diverse DNA and RNA viruses of plants. Proc Natl Acad Sci U S A 96: 14147–14152Hellens RP, Edwards EA, Leyland NR et al (2000) pGreen: a versatile and flexible binary Ti vector for Agrobacterium-mediated plant transformation. Plant Mol Biol 42:819–832Butelli E, Titta L, Giorgio M et al (2008) Enrichment of tomato fruit with health-promoting anthocyanins by expression of select transcription factors. Nat Biotechnol 26: 1301–1308Kapila J, DeRycke R, VanMontagu M et al (1997) An Agrobacterium-mediated transient gene expression system for intact leaves. Plant Sci 122:101–10

Pydna: a simulation and documentation tool for DNA assembly strategies using python

Background: Recent advances in synthetic biology have provided tools to efficiently construct complex DNA molecules which are an important part of many molecular biology and biotechnology projects. The planning of such constructs has traditionally been done manually using a DNA sequence editor which becomes error-prone as scale and complexity of the construction increase. A human-readable formal description of cloning and assembly strategies, which also allows for automatic computer simulation and verification, would therefore be a valuable tool.Results: We have developed pydna, an extensible, free and open source Python library for simulating basic molecular biology DNA unit operations such as restriction digestion, ligation, PCR, primer design, Gibson assembly and homologous recombination. A cloning strategy expressed as a pydna script provides a description that is complete, unambiguous and stable. Execution of the script automatically yields the sequence of the final molecule(s) and that of any intermediate constructs. Pydna has been designed to be understandable for biologists with limited programming skills by providing interfaces that are semantically similar to the description of molecular biology unit operations found in literature.Conclusions: Pydna simplifies both the planning and sharing of cloning strategies and is especially useful for complex or combinatorial DNA molecule construction. An important difference compared to existing tools with similar goals is the use of Python instead of a specifically constructed language, providing a simulation environment that is more flexible and extensible by the user.Thanks to Dr. Aric Hagberg Los Alamos National Laboratory, U.S.A and Sergio Simoes, Universidade de Sao Paulo, Brasil for help with NetworkX and graph theory in general. Thanks to Henrik Bengtsson, Dept of Epidemiology & Biostatistics, University of California San Francisco, U.S.A. for critical reading of the manuscript. Thanks to the 2013 Bioinformatics 6605 N4 students A. Coelho, A. Faria, A. Neves D. Yelshyna and E. Costa for testing. This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT) [PTDC/AAC-AMB/120940/2010, EXPL/BBB-BIO/1772/2013]; and the FEDER POFC-COMPETE [PEst-C/BIA/UI4050/2011]. FA and GR were supported by FCT fellowships [SFRH/BD/80934/2011 and SFRH/BD/42565/2007, respectively].info:eu-repo/semantics/publishedVersio

Generic 3D Representation via Pose Estimation and Matching

Though a large body of computer vision research has investigated developing generic semantic representations, efforts towards developing a similar representation for 3D has been limited. In this paper, we learn a generic 3D representation through solving a set of foundational proxy 3D tasks: object-centric camera pose estimation and wide baseline feature matching. Our method is based upon the premise that by providing supervision over a set of carefully selected foundational tasks, generalization to novel tasks and abstraction capabilities can be achieved. We empirically show that the internal representation of a multi-task ConvNet trained to solve the above core problems generalizes to novel 3D tasks (e.g., scene layout estimation, object pose estimation, surface normal estimation) without the need for fine-tuning and shows traits of abstraction abilities (e.g., cross-modality pose estimation). In the context of the core supervised tasks, we demonstrate our representation achieves state-of-the-art wide baseline feature matching results without requiring apriori rectification (unlike SIFT and the majority of learned features). We also show 6DOF camera pose estimation given a pair local image patches. The accuracy of both supervised tasks come comparable to humans. Finally, we contribute a large-scale dataset composed of object-centric street view scenes along with point correspondences and camera pose information, and conclude with a discussion on the learned representation and open research questions.Comment: Published in ECCV16. See the project website http://3drepresentation.stanford.edu/ and dataset website https://github.com/amir32002/3D_Street_Vie

Letter processing and font information during reading: beyond distinctiveness, where vision meets design

Letter identification is a critical front end of the reading process. In general, conceptualizations of the identification process have emphasized arbitrary sets of distinctive features. However, a richer view of letter processing incorporates principles from the field of type design, including an emphasis on uniformities across letters within a font. The importance of uniformities is supported by a small body of research indicating that consistency of font increases letter identification efficiency. We review design concepts and the relevant literature, with the goal of stimulating further thinking about letter processing during reading

Reagentless Affimer- and antibody-based impedimetric biosensors for CEA-detection using a novel non-conducting polymer

Polyoctopamine (POct), an amine-functionalised non-conducting polymer, as the transducer layer in an electrochemical biosensor, is presented. This polymer offers versatile covalent coupling either through thiol linker conjugation, carboxyl or aldehyde functional groups without the requirement of pre- or post-surface activation. The colorectal cancer biomarker carcinoembryonic antigen (CEA) was selected as the target analyte, whilst an antibody and a synthetic binding protein, an Affimer, were used as distinct bioreceptors to demonstrate the versatility of polyoctopamine as a transducer polymer layer for oriented immobilisation of the bioreceptors. The electrodeposited polymer layer was characterised using cyclic voltammetry, electrochemical impedance spectroscopy, and on-sensor chemiluminescent blotting. The performance of optimised POct-based biosensors were tested in spiked human serum. Results showed that the electropolymerisation of octopamine on screen printed gold electrode generates a thin polymer film with low resistance. Close proximity of the immobilised bioreceptors to the transducer layer greatly enhanced the sensitivity detection. The sensitivity of the smaller monomeric bioreceptor (Affimer, 12.6 kDa) to detect CEA was comparable to the dimeric antibody (150 kDa) with limit of detection at 11.76 fM which is significantly lower than the basal clinical levels of 25 pM. However, the Affimer-based sensor had a narrower dynamic range compared to the immunosensor (1–100 fM vs. 1 fM – 100 nM, respectively). All electrochemical measurements were done in less than 5 min with small sample volumes (10 μl). Hence, polyoctopamine features a simple fabrication of impedimetric biosensors using amine-functionalisation technique, provides rapid response time with enhanced sensitivity and label-free detection