Präzision MRT-basierter Gelenkflächen- und Knorpeldickenanalysen im Kniegelenk bei Verwendung einer schnellen Wasseranregungs-Sequenz und eines semiautomatischen Segmentierungs-Algorithmus

The aim of this study was to analyse the precision of three-dimensional joint surface and cartilage thickness measurements in the knee, using a fast, high-resolution water-excitation sequence and a semiautomated segmentation algorithm. The knee joint of 8 healthy volunteers, aged 22 to 29 years, were examined at a resolution of 1.5 mm x 0.31 mm x 0.31 mm, with four sagittal data sets being acquired after repositioning the joint. After semiautomated segmentation with a B-spline Snake algorithm and 3D reconstruction of the patellar, femoral and tibial cartilages, the joint surface areas (triangulation), cartilage volume, and mean and maximum thickness (Euclidean distance transformation) were analysed, independently of the orientation of the sections. The precision (CV%) for the surface areas was 2.1 to 6.6%. The mean cartilage thickness and cartilage volume showed coefficients of 1.9 to 3.5% (except for the femoral condyles), the value for the medial femoral condyle being 9.1%, and for the lateral condyle 6.5%. For maximum thickness, coefficients of between 2.6 and 5.9% were found. In the present study we investigate for the first time the precision of MRI-based joint surface area measurements in the knee, and of cartilage thickness analyses in the femur. Using a selective water-excitation sequence, the acquisition time can be reduced by more than 50%. The poorer precision in the femoral condyles can be attributed to partial Volume effects that occur at the edges of the joint surfaces with a sagittal image protocol. Since MRI is non-invasive, it is highly suitable for examination of healthy subjects (generation of individual finite element models, analysis of functional adaptation to mechanical stimulation, measurement of cartilage deformation in vivo) and as a diagnostic tool for follow-up, indication for therapy, and objective evaluation of new therapeutic agents in osteoarthritis

Glutamate receptor-like channels are essential for chemotaxis and reproduction in mosses

The deposited article version is a "Accelerated Article Preview" provided by Nature Publishing Group, and it contains attached the supplementary materials within the pdf.». This publication hasn't any creative commons license associated.Glutamate receptors are well characterized channels that mediate cell-to-cell communication during neurotransmission in animals. Nevertheless, information regarding their functional role in organisms without nervous systems is still limited. In plants, Glutamate Receptor-like (GLR) genes have been implicated in defence against pathogens, reproduction, control of stomata aperture and light signal transduction(1-5). However, the numerous GLR genes present in angiosperm genomes (20 to 70)(6) has prevented the observation of strong phenotypes in loss-of-function mutants. Here, we show that in the moss Physcomitrella patens, a basal land plant, mutation of GLR genes cause sperm failure in targeting the female reproductive organs. In addition, we show that GLR genes encode non-selective Ca(2+) permeable channels that can regulate cytoplasmic Ca(2+) and are needed to induce the expression of a BELL1-like transcription factor essential for zygote development. Our work reveals novel functions for GLRs in sperm chemotaxis and transcriptional regulation. Sperm chemotaxis is essential for fertilization in both animals and early land plants like bryophytes and pteridophytes. Therefore, our results are suggestive that ionotropic glutamate receptors may have been conserved throughout plant evolution to mediate cell-to-cell communication during sexual reproduction.Phillips University; Oxford University; University of Marburg; University of Muenster; MarieCurie ITN-Plant Origins grant: (FP7-PEOPLE-ITN-2008); FCT grants: (BEX-BCM/0376/2012; PTDC/BIA-PLA/4018/2012); NSF-US grant: (MCB 1616437/2016).info:eu-repo/semantics/acceptedVersio

Influence of Cytokines on HIV-Specific Antibody-Dependent Cellular Cytotoxicity Activation Profile of Natural Killer Cells

There is growing interest in HIV-specific antibody-dependent cellular cytotoxicity (ADCC) as an effective immune response to prevent or control HIV infection. ADCC relies on innate immune effector cells, particularly NK cells, to mediate control of virus-infected cells. The activation of NK cells (i.e., expression of cytokines and/or degranulation) by ADCC antibodies in serum is likely subject to the influence of other factors that are also present. We observed that the HIV-specific ADCC antibodies, within serum samples from a panel of HIV-infected individuals induced divergent activation profiles of NK cells from the same donor. Some serum samples primarily induced NK cell cytokine expression (i.e., IFNγ), some primarily initiated NK cell expression of a degranulation marker (CD107a) and others initiated a similar magnitude of responses across both effector functions. We therefore evaluated a number of HIV-relevant soluble factors for their influence on the activation of NK cells by HIV-specific ADCC antibodies. Key findings were that the cytokines IL-15 and IL-10 consistently enhanced the ability of NK cells to respond to HIV-specific ADCC antibodies. Furthermore, IL-15 was demonstrated to potently activate “educated” KIR3DL1+ NK cells from individuals carrying its HLA-Bw4 ligand. The cytokine was also demonstrated to activate “uneducated” KIR3DL1+ NK cells from HLA-Bw6 homozygotes, but to a lesser extent. Our results show that cytokines influence the ability of NK cells to respond to ADCC antibodies in vitro. Manipulating the immunological environment to enhance the potency of NK cell-mediated HIV-specific ADCC effector functions could be a promising immunotherapy or vaccine strategy

A voz dos bandos: colectivos de justiça e ritos da palavra portuguesa em Timor Leste colonial

Este artigo examina as relações entre o discurso da justiça e a prática do ritual nos bandos do governo colonial português em Timor Leste, entre a segunda metade do século XIX e as primeiras décadas do século XX. Os bandos consistiam em ordens e instruções de comando emanadas pelo governador português em Díli, e comunicadas de forma cerimonial por oficiais às populações dos diversos reinos timorenses dispersos pelo país. Bandos eram um instrumento por excelência de governação colonial dos assuntos indígenas, servindo para arbitrar conflitos, punir transgressões e, em geral, instituir realidades no mundo timorense. Contudo, esta instituição assumiu igualmente uma singular expressão nos usos timorenses, servindo bandos para comunicar também as ordens de autoridades tradicionais, os liurais. O artigo acompanha as variações coloniais e indígenas que os bandos adquiriram em Timor Leste, conceptualizando-os enquanto colectivos de justiça. Ao considerar assim os bandos como colectivos – formações heterogéneas em que elementos linguísticos e não linguísticos se combinam na produção de efeitos de poder sobre as populações – o artigo propõe uma via conceptual alternativa às perspectivas linguísticas e literárias de análise do discurso colonial

Core and face-sheet anisotropy in deformation and buckling of sandwich Panels

A theoretical study of the effects of face sheets anisotropy and of the transverse compressibility of the core on buckling and deformation of sandwich flat/curved panels is presented. Additionally, the effect of core orthotropy is addressed. The analysis is carried out in the context of a newly geometrically nonlinear higher-order sandwich shell model developed by the authors. An analytical solution is obtained by means of an extended Galerkin procedure. Both the overall buckling mode and the local face wrinkling instability mode are addressed. It is observed that the global and local instabilities are coupled rather than being independent features. Furthermore, the face wrinkling instability might have a considerable effect on the overall deformation behavior of the structure in the (global) prebuckling range. Both the stacking sequence of the face sheets and the orthotropicity of the core are found to have a significant effect on the occurrence of the different instability modes

Recent results on the effect of the transverse core compressibility on the static and dynamic response of sandwich structures

This paper is devoted to a study of the effects played by transverse core compressibility of sandwich plates and shells on their static and dynamic behavior. The analysis is based on a higher-order structural model using the standard Kirchhoff-Love assumption for the face sheets and a higher order displacement representation for the core layer. The model accounts for the geometrical nonlinearities that are considered in the von Karman sense and for initial geometric imperfections. Transverse shear effects are included in the soft-core layer. Consistent equations of motion and boundary conditions are derived via the application of Hamilton's principle. In the cases that are analyzed and presented in this paper, it was revealed that the static and dynamic buckling/response and postbuckling of flat and curved sandwich structures, are strongly affected by transverse compressibility of the core. It is also shown that in the context of this structural model, the wrinkling instability and response are captured directly from the derived governing equations, and not, as customarily, via a post-processing analysis

Transient dynamic response of sandwich shells with transversely compressible core

The present study provides an investigation of the effect of the transverse core compressibility on the dynamic buckling response of sandwich structures. The study utilizes a previous v. Kármán type higher-order model for shallow sandwich shells. An analytical solution is obtained by means of an extended Galerkin procedure in conjunction with an explicit fourth order Runge-Kutta algorithm to solve the transient problem. In an example analysis, it is observed that the transverse core compressibility can have strong effects even on the global response of sandwich structures

Advances in the structural modeling of elastic sandwich panels

The area of sandwich construction has been an active field of research for more than five decades. During this period, a large number of mathematical models for structural sandwich panels has been provided, ranging from the early sandwich membrane models to more sophisticated recent approaches. Especially during the past decade, the increasing demand for high-performance, lightweight structures has stimulated a strong trend toward the develoment of refined models for sandwich plates and shells. The main focus of the present paper is a survey of recent developments and contemporary trends in the modeling of the deformation and buckling behavior of sandwich shells. The development of refined sandwich models is illustrated by an approach recently proposed by the authors. The basic ideas and features of this model are outlined and compared to alternative recent approaches presented by other authors

IR SPECTROSCOPY WITH A DOUBLE MODULATION SIDEBAND TECHNIQUE

Author Institution: Abteilung Physikalische Chemie, Universit\""{a}t Ulm, Einsteinallee; Laboratoire de Spectronomie, Mol\'{e}culaire et InstrumentationWe have applied both microwave and radio frequency modulation to $CO_{2}$ laser lines using only one CdTe modulator. As a result, a grid of closely spaced ($\Delta\nu\times 1 MHz$) and tunable infrared frequencies is generated. This technique was used to perform infrared-infrared double resonance experiments on the molecules $^{28}SiH_{4}$ and $^{28}SiF_{4}$ and to observe the Stark splitting due to extremely small dipole moments. As a preliminary result we obtained values for several dipole moment parameters which agree with measurements performed with other techniques