Disruption of host-seeking behaviour by the salmon louse, Lepeophtheirus salmonis, using botanically derived repellents.

PubMed

O'Shea, B; Wadsworth, S; Pino Marambio, J; Birkett, M A; Pickett, J A; Mordue Luntz, A J

2017-04-01

The potential for developing botanically derived natural products as novel feed-through repellents for disrupting settlement of the salmon louse, Lepeophtheirus salmonis (Caligidae) upon farmed Atlantic salmon, Salmo salar, was investigated using an established laboratory vertical Y-tube behavioural bioassay for assessing copepodid behaviour. Responses to artificial sea water conditioned with the odour of salmon, or to the known salmon-derived kairomone component, α-isophorone, in admixture with selected botanical materials previously known to interfere with invertebrate arthropod host location were recorded. Materials included oils extracted from garlic, Allium sativum (Amaryllidaceae), rosemary, Rosmarinus officinalis (Lamiaceae), lavender, Lavandula angustifolia (Lamiaceae), and bog myrtle, Myrica gale (Myricaceae), and individual components (diallyl sulphide and diallyl disulphide from garlic; allyl, propyl, butyl, 4-pentenyl and 2-phenylethyl isothiocyanate from plants in the Brassica genus). Removal of attraction to salmon-conditioned water (SCW) or α-isophorone was observed when listed materials were presented at extremely low parts per trillion (ppt), that is picograms per litre or 10 -12 level. Significant masking of attraction to SCW was observed at a level of 10 ppt for diallyl disulphide and diallyl sulphide, and allyl isothiocyanate and butyl isothiocyanate. The potential of very low concentrations of masking compounds to disrupt Le. salmonis copepodid settlement on a host fish has been demonstrated in vitro. © 2016 John Wiley & Sons Ltd.

Stacking and T-shape competition in aromatic-aromatic amino acid interactions.

PubMed

Chelli, Riccardo; Gervasio, Francesco Luigi; Procacci, Piero; Schettino, Vincenzo

2002-05-29

The potential of mean force of interacting aromatic amino acids is calculated using molecular dynamics simulations. The free energy surface is determined in order to study stacking and T-shape competition for phenylalanine-phenylalanine (Phe-Phe), phenylalanine-tyrosine (Phe-Tyr), and tyrosine-tyrosine (Tyr-Tyr) complexes in vacuo, water, carbon tetrachloride, and methanol. Stacked structures are favored in all solvents with the exception of the Tyr-Tyr complex in carbon tetrachloride, where T-shaped structures are also important. The effect of anchoring the two alpha-carbons (C(alpha)) at selected distances is investigated. We find that short and large C(alpha)-C(alpha) distances favor stacked and T-shaped structures, respectively. We analyze a set of 2396 protein structures resolved experimentally. Comparison of theoretical free energies for the complexes to the experimental analogue shows that Tyr-Tyr interaction occurs mainly at the protein surface, while Phe-Tyr and Phe-Phe interactions are more frequent in the hydrophobic protein core. This is confirmed by the Voronoi polyhedron analysis on the database protein structures. As found from the free energy calculation, analysis of the protein database has shown that proximal and distal interacting aromatic residues are predominantly stacked and T-shaped, respectively.

A T-shape linear piezoelectric motor with single foot.

PubMed

Liu, Yingxiang; Chen, Weishan; Yang, Xiaohui; Liu, Junkao

2015-02-01

A new T-shape piezoelectric motor using the hybrid of two orthogonal longitudinal vibrations is proposed in this work. Six pieces of PZT ceramic plates are bonded on the upside and downside surfaces of a T-shape duralumin alloy base respectively to form the proposed motor. Elliptical movement can be generated on the driving tip by applying sine and cosine voltages to the PZT elements. The horizontal displacement of the driving tip will push the runner while the vertical displacement can overcome the preload. Finite element method is used to accomplish the design and analysis process. The resonance frequencies of the two vibration modes are tuned to be close by modal analysis, while the motion trajectory of the driving tip is observed by transient analysis. After the fabrication of a prototype, the vibration characteristics and mechanical output ability are measured. The no-load speed and the maximum output thrust force of the proposed motor are tested to be 718 mm/s and 3.5 N under an exciting frequency of 53.1 kHz. The proposed T-shape piezoelectric motor exhibits merits of simple structure, easy to realize miniaturization, easy to be fabricated, and high power-to-weight ratio. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and characterization of shape-memory poly carbonate urethane microspheres for future vascular embolization.

PubMed

Liu, Rongrong; Dai, Honglian; Zhou, Qian; Zhang, Qian; Zhang, Ping

2016-08-01

Two types of shape memory poly carbonate urethanes (PCUs) microspheres were synthesized by pre-polymerization and suspension polymerization, based on Polycarbonate diol (PCDL) as the soft segment, Isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI) as the hard segments and 1,4-butanediol (BDO) as the chain expanding agent. The structure, crystallinity, and thermal property of the two synthesized PCUs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Differential scanning calorimetery (DSC), respectively. The results showed that the two types of PCUs exhibited high thermal stability with phase separation and semi-crystallinity. Also, the results of the compression test displayed that the shape fixity and the shape recovery of two PCUs were more than 90% compared to the originals, indicating their similar bio-applicability and shape-memory properties. The tensile strength, elongation at break was enhanced by introducing and increasing content of HDI. The water contact angles of PCUs decreased and their surface tension increased by surface modified with Bovine serum albumin (BSA). Furthermore, the biological study results of two types of PCUs from the platelet adhesion test and the cell proliferation inhibition test indicated they had some biocompatibilites. Hence, the PCU microspheres might represent a smart and shape-memory embolic agent for vascular embolization.

Assessment of Coronal Spinal Alignment for Adult Spine Deformity Cases After Intraoperative T Square Shaped Use.

PubMed

Kurra, Swamy; Metkar, Umesh; Yirenkyi, Henaku; Tallarico, Richard A; Lavelle, William F

Retrospectively reviewed surgeries between 2011 and 2015 of patients who underwent posterior spinal deformity instrumentation with constructs involving fusions to pelvis and encompassing at least five levels. Measure the radiographic outcomes of coronal malalignment (CM) after use of an intraoperative T square shaped instrument in posterior spinal deformity surgeries with at least five levels of fusion and extension to pelvis. Neuromuscular children found to benefit from intraoperative T square technique to help achieve proper coronal spinal balance with extensive fusions. This intraoperative technique used in our posterior spine deformity instrumentation surgeries with the aforementioned parameters. There were 50 patients: n = 16 with intraoperative T square and n = 34 no-T square shaped device. Subgroups divided based on greater than 20 mm displacement and greater than 40 mm displacement of the C7 plumb line to the central sacral vertical line on either side in preoperative radiographs. We analyzed the demographics and the pre- and postoperative radiographic parameters of standing films: standing CM (displacement of C7 plumb line to central sacral vertical line), and major coronal Cobb angles in total sample and subgroups and compared T square shaped device with no-T square shaped device use by analysis of variance. A p value ≤.05 is statistically significant. In the total sample, though postoperative CM mean was not statistically different, we observed greater CM corrections in patients where a T square shaped device was used (70%) versus no-T square shaped device used (18%). In >20 mm and >40 mm subgroups, the postoperative mean CM values were statistically lower for the patients where a T square shaped device was used, p = .016 and p = .003, respectively. Cobb corrections were statistically higher for T square shaped device use in both >20 mm and >40 mm subgroups, 68%, respectively. The intraoperative T square shaped device technique had a positive effect on

How polarity shapes the destiny of T cells.

PubMed

Russell, Sarah

2008-01-15

The differentiation, activation and expansion of T cells are dictated by their integrated response to a complex array of extracellular signals. Recent studies provide insight into how these signals are integrated and demonstrate a key role for cell shape in many aspects of T-cell signalling. T cells polarise during migration, antigen presentation and cell division to give rise to daughter cells that can have different cell fates. In each case, the polarity of the T cell facilitates this activity. This raises the possibility that adoption of a polarised state acts as a positive feedback mechanism to enhance responses to specific signals. Similarly, in asymmetric division of other cell types, the distribution of different molecules into each daughter can have profound consequences for proliferation, death and differentiation. The mechanisms of polarity regulation are far better understood in cells such as epithelial cells, neurons and neuronal precursors, and the fertilised zygote. With the emerging parallels between polarity in these cells and T cells, we should now be able to elucidate how polarity affects signalling and cell fate determination in T cells.

5S rRNA-derived and tRNA-derived SINEs in fruit bats.

PubMed

Gogolevsky, Konstantin P; Vassetzky, Nikita S; Kramerov, Dmitri A

2009-05-01

Most short retroposons (SINEs) descend from cellular tRNA of 7SL RNA. Here, four new SINEs were found in megabats (Megachiroptera) but neither in microbats nor in other mammals. Two of them, MEG-RS and MEG-RL, descend from another cellular RNA, 5S rRNA; one (MEG-T2) is a tRNA-derived SINE; and MEG-TR is a hybrid tRNA/5S rRNA SINE. Insertion locus analysis suggests that these SINEs were active in the recent fruit bat evolution. Analysis of MEG-RS and MEG-RL in comparison with other few 5S rRNA-derived SINEs demonstrates that the internal RNA polymerase III promoter is their most invariant region, while the secondary structure is more variable. The mechanisms underlying the modular structure of these and other SINEs as well as their variation are discussed. The scenario of evolution of MEG SINEs is proposed.

Derivation of planetary topography using multi-image shape-from-shading

USGS Publications Warehouse

Lohse, V.; Heipke, C.; Kirk, R.L.

2006-01-01

In many cases, the derivation of high-resolution digital terrain models (DTMs) from planetary surfaces using conventional digital image matching is a problem. The matching methods need at least one stereo pair of images with sufficient texture. However, many space missions provide only a few stereo images and planetary surfaces often possess insufficient texture. This paper describes a method for the generation of high-resolution DTMs from planetary surfaces, which has the potential to overcome the described problem. The suggested method, developed by our group, is based on shape-from-shading using an arbitrary number of digital optical images, and is termed "multi-image shape-from-shading" (MI-SFS). The paper contains an explanation of the theory of MI-SFS, followed by a presentation of current results, which were obtained using images from NASA's lunar mission Clementine, and constitute the first practical application with our method using extraterrestrial imagery. The lunar surface is reconstructed under the assumption of different kinds of reflectance models (e.g. Lommel-Seeliger and Lambert). The represented results show that the derivation of a high-resolution DTM of real digital planetary images by means of MI-SFS is feasible. ?? 2006 Elsevier Ltd. All rights reserved.

An analytical model of a curved beam with a T shaped cross section

NASA Astrophysics Data System (ADS)

Hull, Andrew J.; Perez, Daniel; Cox, Donald L.

2018-03-01

This paper derives a comprehensive analytical dynamic model of a closed circular beam that has a T shaped cross section. The new model includes in-plane and out-of-plane vibrations derived using continuous media expressions which produces results that have a valid frequency range above those available from traditional lumped parameter models. The web is modeled using two-dimensional elasticity equations for in-plane motion and the classical flexural plate equation for out-of-plane motion. The flange is modeled using two sets of Donnell shell equations: one for the left side of the flange and one for the right side of the flange. The governing differential equations are solved with unknown wave propagation coefficients multiplied by spatial domain and time domain functions which are inserted into equilibrium and continuity equations at the intersection of the web and flange and into boundary conditions at the edges of the system resulting in 24 algebraic equations. These equations are solved to yield the wave propagation coefficients and this produces a solution to the displacement field in all three dimensions. An example problem is formulated and compared to results from finite element analysis.

Protein structure shapes immunodominance in the CD4 T cell response to yellow fever vaccination.

PubMed

Koblischke, Maximilian; Mackroth, Maria S; Schwaiger, Julia; Fae, Ingrid; Fischer, Gottfried; Stiasny, Karin; Heinz, Franz X; Aberle, Judith H

2017-08-21

The live attenuated yellow fever (YF) vaccine is a highly effective human vaccine and induces long-term protective neutralizing antibodies directed against the viral envelope protein E. The generation of such antibodies requires the help of CD4 T cells which recognize peptides derived from proteins in virus particles internalized and processed by E-specific B cells. The CD4 T helper cell response is restricted to few immunodominant epitopes, but the mechanisms of their selection are largely unknown. Here, we report that CD4 T cell responses elicited by the YF-17D vaccine are focused to hotspots of two helices of the viral capsid protein and to exposed strands and loops of E. We found that the locations of immunodominant epitopes within three-dimensional protein structures exhibit a high degree of overlap between YF virus and the structurally homologous flavivirus tick-borne encephalitis virus, although amino acid sequence identity of the epitope regions is only 15-45%. The restriction of epitopes to exposed E protein surfaces and their strikingly similar positioning within proteins of distantly related flaviviruses are consistent with a strong influence of protein structure that shapes CD4 T cell responses and provide leads for a rational design of immunogens for vaccination.

tRNA-Derived Small RNA: A Novel Regulatory Small Non-Coding RNA.

PubMed

Li, Siqi; Xu, Zhengping; Sheng, Jinghao

2018-05-10

Deep analysis of next-generation sequencing data unveils numerous small non-coding RNAs with distinct functions. Recently, fragments derived from tRNA, named as tRNA-derived small RNA (tsRNA), have attracted broad attention. There are mainly two types of tsRNAs, including tRNA-derived stress-induced RNA (tiRNA) and tRNA-derived fragment (tRF), which differ in the cleavage position of the precursor or mature tRNA transcript. Emerging evidence has shown that tsRNAs are not merely tRNA degradation debris but have been recognized to play regulatory roles in many specific physiological and pathological processes. In this review, we summarize the biogeneses of various tsRNAs, present the emerging concepts regarding functions and mechanisms of action of tsRNAs, highlight the potential application of tsRNAs in human diseases, and put forward the current problems and future research directions.

True and masked three-coordinate T-shaped platinum(II) intermediates.

PubMed

Ortuño, Manuel A; Conejero, Salvador; Lledós, Agustí

2013-01-01

Although four-coordinate square-planar geometries, with a formally 16-electron counting, are absolutely dominant in isolated Pt(II) complexes, three-coordinate, 14-electron Pt(II) complexes are believed to be key intermediates in a number of platinum-mediated organometallic transformations. Although very few authenticated three-coordinate Pt(II) complexes have been characterized, a much larger number of complexes can be described as operationally three-coordinate in a kinetic sense. In these compounds, which we have called masked T-shaped complexes, the fourth position is occupied by a very weak ligand (agostic bond, solvent molecule or counteranion), which can be easily displaced. This review summarizes the structural features of the true and masked T-shaped Pt(II) complexes reported so far and describes synthetic strategies employed for their formation. Moreover, recent experimental and theoretical reports are analyzed, which suggest the involvement of such intermediates in reaction mechanisms, particularly C-H bond-activation processes.

Systemic T Cells Immunosuppression of Glioma Stem Cell-Derived Exosomes Is Mediated by Monocytic Myeloid-Derived Suppressor Cells

PubMed Central

Domenis, Rossana; Cesselli, Daniela; Toffoletto, Barbara; Bourkoula, Evgenia; Caponnetto, Federica; Manini, Ivana; Beltrami, Antonio Paolo; Ius, Tamara; Skrap, Miran; Di Loreto, Carla

2017-01-01

A major contributing factor to glioma development and progression is its ability to evade the immune system. Nano-meter sized vesicles, exosomes, secreted by glioma-stem cells (GSC) can act as mediators of intercellular communication to promote tumor immune escape. Here, we investigated the immunomodulatory properties of GCS-derived exosomes on different peripheral immune cell populations. Healthy donor peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3, anti-CD28 and IL-2, were treated with GSC-derived exosomes. Phenotypic characterization, cell proliferation, Th1/Th2 cytokine secretion and intracellular cytokine production were analysed by distinguishing among effector T cells, regulatory T cells and monocytes. In unfractionated PBMCs, GSC-derived exosomes inhibited T cell activation (CD25 and CD69 expression), proliferation and Th1 cytokine production, and did not affect cell viability or regulatory T-cell suppression ability. Furthermore, exosomes were able to enhance proliferation of purified CD4+ T cells. In PBMCs culture, glioma-derived exosomes directly promoted IL-10 and arginase-1 production and downregulation of HLA-DR by unstimulated CD14+ monocytic cells, that displayed an immunophenotype resembling that of monocytic myeloid-derived suppressor cells (Mo-MDSCs). Importantly, the removal of CD14+ monocytic cell fraction from PBMCs restored T-cell proliferation. The same results were observed with exosomes purified from plasma of glioblastoma patients. Our results indicate that glioma-derived exosomes suppress T-cell immune response by acting on monocyte maturation rather than on direct interaction with T cells. Selective targeting of Mo-MDSC to treat glioma should be considered with regard to how immune cells allow the acquirement of effector functions and therefore counteracting tumor progression. PMID:28107450

Systemic T Cells Immunosuppression of Glioma Stem Cell-Derived Exosomes Is Mediated by Monocytic Myeloid-Derived Suppressor Cells.

PubMed

Domenis, Rossana; Cesselli, Daniela; Toffoletto, Barbara; Bourkoula, Evgenia; Caponnetto, Federica; Manini, Ivana; Beltrami, Antonio Paolo; Ius, Tamara; Skrap, Miran; Di Loreto, Carla; Gri, Giorgia

2017-01-01

A major contributing factor to glioma development and progression is its ability to evade the immune system. Nano-meter sized vesicles, exosomes, secreted by glioma-stem cells (GSC) can act as mediators of intercellular communication to promote tumor immune escape. Here, we investigated the immunomodulatory properties of GCS-derived exosomes on different peripheral immune cell populations. Healthy donor peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3, anti-CD28 and IL-2, were treated with GSC-derived exosomes. Phenotypic characterization, cell proliferation, Th1/Th2 cytokine secretion and intracellular cytokine production were analysed by distinguishing among effector T cells, regulatory T cells and monocytes. In unfractionated PBMCs, GSC-derived exosomes inhibited T cell activation (CD25 and CD69 expression), proliferation and Th1 cytokine production, and did not affect cell viability or regulatory T-cell suppression ability. Furthermore, exosomes were able to enhance proliferation of purified CD4+ T cells. In PBMCs culture, glioma-derived exosomes directly promoted IL-10 and arginase-1 production and downregulation of HLA-DR by unstimulated CD14+ monocytic cells, that displayed an immunophenotype resembling that of monocytic myeloid-derived suppressor cells (Mo-MDSCs). Importantly, the removal of CD14+ monocytic cell fraction from PBMCs restored T-cell proliferation. The same results were observed with exosomes purified from plasma of glioblastoma patients. Our results indicate that glioma-derived exosomes suppress T-cell immune response by acting on monocyte maturation rather than on direct interaction with T cells. Selective targeting of Mo-MDSC to treat glioma should be considered with regard to how immune cells allow the acquirement of effector functions and therefore counteracting tumor progression.

Spectrum fatigue testing of T-shaped tension clips

NASA Astrophysics Data System (ADS)

Palmberg, Bjoern; Wallstenius, Bengt

1992-12-01

An investigation of strain distributions during static loading and crack propagation and fatigue lives under spectrum loading of T-shaped tension clips was carried out. Three slightly different, with respect to geometry, T shaped tension clips made of aluminum alloy 7010-T73651 were studied. The type 1 and 4 test specimens were different only with respect to the web thickness of the clamping end. The type 1 and 2 test specimens were different with repect to milled flat circular countersink around the holes in the type 2 specimens and with respect to the radius between the web and foot. The spectrum fatigue loading consisted of a load sequence representative for the wing root, lower side, of a fighter aircraft. Tests were made at two different load levels for each specimen type. The strain measurements show that the countersink in the type 2 specimens increases the stresses in the fatigue critical region. This is also manifested in the spectrum fatigue life results, where type 2 specimens show the shortest fatigue lives. The strain measurements show that the torque used for the bolts in joining two test specimens or one test specimen and a dummy has a rather large impact on the strain in the fatigue region. The strains decrease with increasing torque. The spectrum fatigue loading resulted in approximately an equal number of flights to obtain a 10.0 mm crack for specimens of type 1 and 4. This suggests that the type 1 configuration is superior since the web thickness is smaller for this type as compared to the type 4 specimens. In other words, the type 4 specimens have an unnecessary oversize of the clamping end web thickness.

Study of droplet flow in a T-shape microchannel with bottom wall fluctuation

NASA Astrophysics Data System (ADS)

Pang, Yan; Wang, Xiang; Liu, Zhaomiao

2018-03-01

Droplet generation in a T-shape microchannel, with a main channel width of 50 μm , side channel width of 25 μm, and height of 50 μm, is simulated to study the effects of the forced fluctuation of the bottom wall. The periodic fluctuations of the bottom wall are applied on the near junction part of the main channel in the T-shape microchannel. Effects of bottom wall's shape, fluctuation periods, and amplitudes on the droplet generation are covered in the research of this protocol. In the simulation, the average size is affected a little by the fluctuations, but significantly by the fixed shape of the deformed bottom wall, while the droplet size range is expanded by the fluctuations under most of the conditions. Droplet sizes are distributed in a periodic pattern with small amplitude along the relative time when the fluctuation is forced on the bottom wall near the T-junction, while the droplet emerging frequency is not varied by the fluctuation. The droplet velocity is varied by the bottom wall motion, especially under the shorter period and the larger amplitude. When the fluctuation period is similar to the droplet emerging period, the droplet size is as stable as the non-fluctuation case after a development stage at the beginning of flow, while the droplet velocity is varied by the moving wall with the scope up to 80% of the average velocity under the conditions of this investigation.

HUMAN BODY SHAPE INDEX BASED ON AN EXPERIMENTALLY DERIVED MODEL OF HUMAN GROWTH

PubMed Central

Lebiedowska, Maria K.; Alter, Katharine E.; Stanhope, Steven J.

2009-01-01

Objectives To test the assumption of geometrically similar growth by developing experimentally derived models of human body growth during the age interval of 5–18 years; to use the derived growth models to establish a new Human Body Shape Index (HBSI) based on natural age related changes in HBS; and to compare various metrics of relative body weight (body mass index, ponderal index, HBSI) in a sample of 5–18 year old children. Study design Non-disabled Polish children (N=847) participated in this descriptive study. To model growth, the best fit between body height (H) and body mass (M) was calculated for each sex with the allometric equation M= miHχ. HBSI and HBSI were calculated separately for girls and boys, using sex-specific values for χ and a general HBSI from combined data. The customary body mass and ponderal indices were calculated and compared to HBSI values. Results The models of growth were M=13.11H2.84 (R2=.90) and M=13.64H2.68 (R2=.91) for girls and boys respectively. HBSI values contained less inherent variability and were influenced least by growth (age and height) than customary indices. Conclusion Age-related growth during childhood is sex-specific and not geometrically similar. Therefore, indices of human body shape formulated from experimentally derived models of human growth are superior to customary geometric similarity-based indices for the characterization of human body shape in children during the formative growth years. PMID:18154897

Radar-derived asteroid shapes point to a 'zone of stability' for topography slopes and surface erosion rates

NASA Astrophysics Data System (ADS)

Richardson, J.; Graves, K.; Bowling, T.

2014-07-01

Previous studies of the combined effects of asteroid shape, spin, and self-gravity have focused primarily upon the failure limits for bodies with a variety of standard shapes, friction, and cohesion values [1,2,3]. In this study, we look in the opposite direction and utilize 22 asteroid shape-models derived from radar inversion [4] and 7 small body shape-models derived from spacecraft observations [5] to investigate the region in shape/spin space [1,2] wherein self-gravity and rotation combine to produce a stable minimum state with respect to surface potential differences, dynamic topography, slope magnitudes, and erosion rates. This erosional minimum state is self-correcting, such that changes in the body's rotation rate, either up or down, will increase slope magnitudes across the body, thereby driving up erosion rates non-linearly until the body has once again reached a stable, minimized surface state [5]. We investigated this phenomenon in a systematic fashion using a series of synthesized, increasingly prolate spheroid shape models. Adjusting the rotation rate of each synthetic shape to minimize surface potential differences, dynamic topography, and slope magnitudes results in the magenta curve of the figure (right side), defining the zone of maximum surface stability (MSS). This MSS zone is invariant both with respect to body size (gravitational potential and rotational potential scale together with radius), and density when the scaled-spin of [2] is used. Within our sample of observationally derived small-body shape models, slow rotators (Group A: blue points), that are not in the maximum surface stability (MSS) zone and where gravity dominates the slopes, will generally experience moderate erosion rates (left plot) and will tend to move up and to the right in shape/spin space as the body evolves (right plot). Fast rotators (Group C: red points), that are not in the MSS zone and where spin dominates the slopes, will generally experience high erosion rates

Shape Memory Properties and Enzymatic Degradability of Poly(ε-caprolactone)-Based Polyurethane Urea Containing Phenylalanine-Derived Chain Extender.

PubMed

Wang, Rong; Zhang, Fanjun; Lin, Weiwei; Liu, Wenkai; Li, Jiehua; Luo, Feng; Wang, Yaning; Tan, Hong

2018-06-01

Biodegradable shape memory polymers are promising biomaterials for minimally invasive surgical procedures. Herein, a series of linear biodegradable shape memory poly(ε-caprolactone) (PCL)-based polyurethane ureas (PUUs) containing a novel phenylalanine-derived chain extender is synthesized. The phenylalanine-derived chain extender, phenylalanine-hexamethylenediamine-phenylalanine (PHP), contains two chymotrypsin cleaving sites to enhance the enzymatic degradation of PUUs. The degradation rate, the crystallinity, and mechanical properties of PUUs are tailored by the content of PHP. Meanwhile, semicrystalline PCL is not only hydrolytically degradable but also vital for shape memory. Good shape memory ability under body temperature is achieved for PUUs due to the strong interactions in hard segments for permanent crosslinking and the crystallization-melt transition of PCL to switch temporary shape. The PUUs would have a great potential in application as implanting stent. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Finite element simulation of the T-shaped ECAP processing of round samples

NASA Astrophysics Data System (ADS)

Shaban Ghazani, Mehdi; Fardi-Ilkhchy, Ali; Binesh, Behzad

2018-05-01

Grain refinement is the only mechanism that increases the yield strength and toughness of the materials simultaneously. Severe plastic deformation is one of the promising methods to refine the microstructure of materials. Among different severe plastic deformation processes, the T-shaped equal channel angular pressing (T-ECAP) is a relatively new technique. In the present study, finite element analysis was conducted to evaluate the deformation behavior of metals during T-ECAP process. The study was focused mainly on flow characteristics, plastic strain distribution and its homogeneity, damage development, and pressing force which are among the most important factors governing the sound and successful processing of nanostructured materials by severe plastic deformation techniques. The results showed that plastic strain is localized in the bottom side of sample and uniform deformation cannot be possible using T-ECAP processing. Friction coefficient between sample and die channel wall has a little effect on strain distributions in mirror plane and transverse plane of deformed sample. Also, damage analysis showed that superficial cracks may be initiated from bottom side of sample and their propagation will be limited due to the compressive state of stress. It was demonstrated that the V shaped deformation zone are existed in T-ECAP process and the pressing load needed for execution of deformation process is increased with friction.

-X Mixing in T- and V-Shaped Quantum Wires

NASA Astrophysics Data System (ADS)

di Carlo, A.; Pescetelli, S.; Kavokin, A.; Vladimirova, M.; Lugli, P.

1997-11-01

We have applied both tight-binding (TB) and multivalley envelope function (MEF) techniques to calculate the electronic states in T- and V-shaped realistic quantum wires taking into account -X mixing in the conduction band. Strong reduction of the electron quantization energy due to the off-resonant -X mixing has been found in all types of quantum wires. This effect appears to be tied to the localization of the electron wave function and to its overlap with atomic layers next to interfaces.

[Three-dimensional Finite Element Analysis to T-shaped Fracture of Pelvis in Sitting Position].

PubMed

Fan, Yanping; Lei, Jianyin; Liu, Haibo; Li, Zhiqiang; Cai, Xianhua; Chen, Weiyi

2015-10-01

We developed a three-dimensional finite element model of the pelvis. According to Letournel methods, we established a pelvis model of T-shaped fracture with its three different fixation systems, i. e. double column reconstruction plates, anterior column plate combined with posterior column screws and anterior column plate combined with quadrilateral area screws. It was found that the pelvic model was effective and could be used to simulate the mechanical behavior of the pelvis. Three fixation systems had great therapeutic effect on the T-shaped fracture. All fixation systems could increase the stiffness of the model, decrease the stress concentration level and decrease the displacement difference along the fracture line. The quadrilateral area screws, which were drilled into cortical bone, could generate beneficial effect on the T-type fracture. Therefore, the third fixation system mentioned above (i. e. the anterior column plate combined with quadrilateral area screws) has the best biomechanical stability to the T-type fracture.

Ultrafast responses of dipolar and V-shaped dipicolinate derivatives with potential applications in the labeling of biomolecules

NASA Astrophysics Data System (ADS)

Wang, Yaochuan; Liu, Siyuan; Liu, Dajun; Wang, Guiqiu; Xiao, Haibo

2016-02-01

A dipolar dipicolinate derivative, trans-dimethyl-4-[4'-(N,N-diphenylamino)-styry1]-pyridin-2,6-dicarboxylate (P-1), and a P-1based V-shaped compound, {4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl) vinyl]}-N-phenyl-N-{4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl)vinylphenyl]}aniline (P-2), with intense two-photon fluorescence emission properties were systematically investigated by using steady-state absorption and fluorescence spectroscopy, open-aperture Z-scans, and two-photon excited fluorescence (TPF). The two-photon absorption cross-section of the V-shaped compound P-2 in tetrahydrofuran (THF) was determined to be 208 GM, which represents a 6.5-fold enhancement compared with its dipolar counterpart P-1 (32 GM). Extension of the intramolecular charge transfer (ICT) in the V-shaped dipicolinate derivative has been suggested as the mechanism of enhancement. The excited state dynamics from transient absorption spectroscopy were analyzed and discussed. The formation and relaxation lifetimes of the ICT state for these dipicolinate derivatives in THF solutions were found to be several picoseconds and several hundred picoseconds, respectively. The results show an increased ICT character of the V-shaped compound and a potential application for this compound in two-photon fluorescence imaging fields.

T2-weighted MRI-derived textural features reflect prostate cancer aggressiveness: preliminary results.

PubMed

Nketiah, Gabriel; Elschot, Mattijs; Kim, Eugene; Teruel, Jose R; Scheenen, Tom W; Bathen, Tone F; Selnæs, Kirsten M

2017-07-01

To evaluate the diagnostic relevance of T2-weighted (T2W) MRI-derived textural features relative to quantitative physiological parameters derived from diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI in Gleason score (GS) 3+4 and 4+3 prostate cancers. 3T multiparametric-MRI was performed on 23 prostate cancer patients prior to prostatectomy. Textural features [angular second moment (ASM), contrast, correlation, entropy], apparent diffusion coefficient (ADC), and DCE pharmacokinetic parameters (K trans and V e ) were calculated from index tumours delineated on the T2W, DW, and DCE images, respectively. The association between the textural features and prostatectomy GS and the MRI-derived parameters, and the utility of the parameters in differentiating between GS 3+4 and 4+3 prostate cancers were assessed statistically. ASM and entropy correlated significantly (p < 0.05) with both GS and median ADC. Contrast correlated moderately with median ADC. The textural features correlated insignificantly with K trans and V e . GS 4+3 cancers had significantly lower ASM and higher entropy than 3+4 cancers, but insignificant differences in median ADC, K trans , and V e . The combined texture-MRI parameters yielded higher classification accuracy (91%) than the individual parameter sets. T2W MRI-derived textural features could serve as potential diagnostic markers, sensitive to the pathological differences in prostate cancers. • T2W MRI-derived textural features correlate significantly with Gleason score and ADC. • T2W MRI-derived textural features differentiate Gleason score 3+4 from 4+3 cancers. • T2W image textural features could augment tumour characterization.

t-Butyl-Oxycarbonylated Diamines as Building Blocks for Isocyanate-Free Polyurethane/Urea Dispersions and Coatings.

PubMed

Ma, Shuang; Zhang, Huiyi; Sablong, Rafaël J; Koning, Cor E; van Benthem, Rolf A T M

2018-05-01

t-Butyl-oxycarbonylated diamines ("di-Boc-carbamates") are investigated as dicarbamate monomers for diamine/dicarbamate polymerizations. Polyureas (PUs) and polyurethanes (PURs) with high molecular weights are prepared from stoichiometric polymerizations of diamines or diols with N-N'-di-t-butyl-oxycarbonyl isophorone diamine (DiBoc-IPDC) using KOt-Bu as a catalyst, while gelation is observed when an excess of DiBoc-IPDC is used with respect to the diamines or diols. Stable dispersions are obtained from PUs and PURs with 3,3'-diamino-N-methyldipropylamine (DMDPA) as internal dispersing agent. The corresponding PU-based coatings exhibit superior mechanical properties and solvent resistances compared to the polyurethane urea coatings synthesized from diols, DiBoc-IPDC, and DMDPA. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

How Numbers, Nature, and Immune Status of Foxp3+ Regulatory T-Cells Shape the Early Immunological Events in Tumor Development

PubMed Central

Darrasse-Jèze, Guillaume; Podsypanina, Katrina

2013-01-01

The influence of CD4+CD25+Foxp3+ regulatory T-cells (Tregs) on cancer progression has been demonstrated in a large number of preclinical models and confirmed in several types of malignancies. Neoplastic processes trigger an increase of Treg numbers in draining lymph nodes, spleen, blood, and tumors, leading to the suppression of anti-tumor responses. Treg-depletion before or early in tumor development may lead to complete tumor eradication and extends survival of mice and humans. However this strategy is ineffective in established tumors, highlighting the critical role of the early Treg-tumor encounters. In this review, after discussing old and new concepts of immunological tumor tolerance, we focus on the nature (thymus-derived vs. peripherally derived) and status (naïve or activated/memory) of the regulatory T-cells at tumor emergence. The recent discoveries in this field suggest that the activation status of Tregs and effector T-cells (Teffs) at the first encounter with the tumor are essential to shape the fate and speed of the immune response across a variety of tumor models. The relative timing of activation/recruitment of anti-tumor cells vs. tolerogenic cells at tumor emergence appears to be crucial in the identification of tumor cells as friend or foe, which has broad implications for the design of cancer immunotherapies. PMID:24133490

Response of γδ T cells to plant-derived tannins

PubMed Central

Holderness, Jeff; Hedges, Jodi F.; Daughenbaugh, Katie; Kimmel, Emily; Graff, Jill; Freedman, Brett; Jutila, Mark A.

2008-01-01

Many pharmaceutical drugs are isolated from plants used in traditional medicines. Through screening plant extracts, both traditional medicines and compound libraries, new pharmaceutical drugs continue to be identified. Currently, two plant-derived agonists for γδ T cells are described. These plant-derived agonists impart innate effector functions upon distinct γδ T cell subsets. Plant tannins represent one class of γδ T cell agonist and preferentially activate the mucosal population. Mucosal γδ T cells function to modulate tissue immune responses and induce epithelium repair. Select tannins, isolated from apple peel, rapidly induce immune gene transcription in γδ T cells, leading to cytokine production and increased responsiveness to secondary signals. Activity of these tannin preparations tracks to the procyanidin fraction, with the procyanidin trimer (C1) having the most robust activity defined to date. The response to the procyanidins is evolutionarily conserved in that responses are seen with human, bovine, and murine γδ T cells. Procyanidin-induced responses described in this review likely account for the expansion of mucosal γδ T cells seen in mice and rats fed soluble extracts of tannins. Procyanidins may represent a novel approach for treatment of tissue damage, chronic infection, and autoimmune therpies. PMID:19166386

T-duality constraints on higher derivatives revisited

NASA Astrophysics Data System (ADS)

Hohm, Olaf; Zwiebach, Barton

2016-04-01

We ask to what extent are the higher-derivative corrections of string theory constrained by T-duality. The seminal early work by Meissner tests T-duality by reduction to one dimension using a distinguished choice of field variables in which the bosonic string action takes a Gauss-Bonnet-type form. By analyzing all field redefinitions that may or may not be duality covariant and may or may not be gauge covariant we extend the procedure to test T-duality starting from an action expressed in arbitrary field variables. We illustrate the method by showing that it determines uniquely the first-order α' corrections of the bosonic string, up to terms that vanish in one dimension. We also use the method to glean information about the O({α}^' 2}) corrections in the double field theory with Green-Schwarz deformation.

Analyses of carnivore microsatellites and their intimate association with tRNA-derived SINEs.

PubMed

López-Giráldez, Francesc; Andrés, Olga; Domingo-Roura, Xavier; Bosch, Montserrat

2006-10-23

The popularity of microsatellites has greatly increased in the last decade on account of their many applications. However, little is currently understood about the factors that influence their genesis and distribution among and within species genomes. In this work, we analyzed carnivore microsatellite clones from GenBank to study their association with interspersed repeats and elucidate the role of the latter in microsatellite genesis and distribution. We constructed a comprehensive carnivore microsatellite database comprising 1236 clones from GenBank. Thirty-three species of 11 out of 12 carnivore families were represented, although two distantly related species, the domestic dog and cat, were clearly overrepresented. Of these clones, 330 contained tRNALys-derived SINEs and 357 contained other interspersed repeats. Our rough estimates of tRNA SINE copies per haploid genome were much higher than published ones. Our results also revealed a distinct juxtaposition of AG and A-rich repeats and tRNALys-derived SINEs suggesting their coevolution. Both microsatellites arose repeatedly in two regions of the interspersed repeat. Moreover, microsatellites associated with tRNALys-derived SINEs showed the highest complexity and less potential instability. Our results suggest that tRNALys-derived SINEs are a significant source for microsatellite generation in carnivores, especially for AG and A-rich repeat motifs. These observations indicate two modes of microsatellite generation: the expansion and variation of pre-existing tandem repeats and the conversion of sequences with high cryptic simplicity into a repeat array; mechanisms which are not specific to tRNALys-derived SINEs. Microsatellite and interspersed repeat coevolution could also explain different distribution of repeat types among and within species genomes.Finally, due to their higher complexity and lower potential informative content of microsatellites associated with tRNALys-derived SINEs, we recommend avoiding

Analyses of carnivore microsatellites and their intimate association with tRNA-derived SINEs

PubMed Central

López-Giráldez, Francesc; Andrés, Olga; Domingo-Roura, Xavier; Bosch, Montserrat

2006-01-01

Background The popularity of microsatellites has greatly increased in the last decade on account of their many applications. However, little is currently understood about the factors that influence their genesis and distribution among and within species genomes. In this work, we analyzed carnivore microsatellite clones from GenBank to study their association with interspersed repeats and elucidate the role of the latter in microsatellite genesis and distribution. Results We constructed a comprehensive carnivore microsatellite database comprising 1236 clones from GenBank. Thirty-three species of 11 out of 12 carnivore families were represented, although two distantly related species, the domestic dog and cat, were clearly overrepresented. Of these clones, 330 contained tRNALys-derived SINEs and 357 contained other interspersed repeats. Our rough estimates of tRNA SINE copies per haploid genome were much higher than published ones. Our results also revealed a distinct juxtaposition of AG and A-rich repeats and tRNALys-derived SINEs suggesting their coevolution. Both microsatellites arose repeatedly in two regions of the insterspersed repeat. Moreover, microsatellites associated with tRNALys-derived SINEs showed the highest complexity and less potential instability. Conclusion Our results suggest that tRNALys-derived SINEs are a significant source for microsatellite generation in carnivores, especially for AG and A-rich repeat motifs. These observations indicate two modes of microsatellite generation: the expansion and variation of pre-existing tandem repeats and the conversion of sequences with high cryptic simplicity into a repeat array; mechanisms which are not specific to tRNALys-derived SINEs. Microsatellite and interspersed repeat coevolution could also explain different distribution of repeat types among and within species genomes. Finally, due to their higher complexity and lower potential informative content of microsatellites associated with tRNALys-derived

Calcium-mediated shaping of naive CD4 T-cell phenotype and function

PubMed Central

Guichard, Vincent; Bonilla, Nelly; Durand, Aurélie; Audemard-Verger, Alexandra; Guilbert, Thomas; Martin, Bruno

2017-01-01

Continuous contact with self-major histocompatibility complex ligands is essential for the survival of naive CD4 T cells. We have previously shown that the resulting tonic TCR signaling also influences their fate upon activation by increasing their ability to differentiate into induced/peripheral regulatory T cells. To decipher the molecular mechanisms governing this process, we here focus on the TCR signaling cascade and demonstrate that a rise in intracellular calcium levels is sufficient to modulate the phenotype of mouse naive CD4 T cells and to increase their sensitivity to regulatory T-cell polarization signals, both processes relying on calcineurin activation. Accordingly, in vivo calcineurin inhibition leads the most self-reactive naive CD4 T cells to adopt the phenotype of their less self-reactive cell-counterparts. Collectively, our findings demonstrate that calcium-mediated activation of the calcineurin pathway acts as a rheostat to shape both the phenotype and effector potential of naive CD4 T cells in the steady-state. PMID:29239722

The column strength of aluminum alloy 75S-T extruded shapes

NASA Technical Reports Server (NTRS)

Holt, Marshall; Leary, J R

1946-01-01

Because the tensile strength and tensile yield strength of alloy 75S-T are appreciably higher than those of the materials used in the tests leading to the use of the straight-line column curve, it appeared advisable to establish the curve of column strength by test rather than by extrapolation of relations determined empirically in the earlier tests. The object of this investigation was to determine the curve of column strength for extruded aluminum alloy 75S-T. In addition to three extruded shapes, a rolled-and-drawn round rod was included. Specimens of various lengths covering the range of effective slenderness ratios up to about 100 were tested.

Tunable plasmon-induced transparency with graphene-based T-shaped array metasurfaces

NASA Astrophysics Data System (ADS)

Niu, Yuying; Wang, Jicheng; Hu, Zhengda; Zhang, Feng

2018-06-01

The frequency tunable Plasmonic induced transparency (PIT) effect is researched with a periodically patterned T-shaped graphene array in mid-infrared region. We adjust the geometrical parameters to obtain the optimized combination for the realization of the PIT response and use the coupled Lorentz oscillator model to analysis the physical mechanism. Due to the properties of graphene, the PIT effect can be easily and markedly enhanced with the increase of chemical potential and carrier mobility. The frequency of PIT effect is also insensitive with the angle of incident light. In addition, we also propose the π shaped structure to realizing the double-peak PIT effect. The results offer a flexible approach for the development of tunable graphene-based photonic devices.

Novel T-shaped GaSb/InAsN quantum wire for mid-infrared laser applications

NASA Astrophysics Data System (ADS)

Ridene, Said

2017-10-01

In this work, we investigate GaSb /InAs1-xNx T-shaped quantum wire active region in mid-infrared laser. Multi-band k.p model and variational formalism are applied to find the confinement energies, the band structures, and optical gain. We then present a method of numerical calculation that is suited to any T-shaped quantum wire. By tuning the quantum wire thickness, the TE- and TM-polarized optical gain up to 21 ×103 cm-1 can be obtained for λ = 3.11 μm at room temperature (RT), which is very promising to serve as an alternative active region for high-efficiency mid-infrared laser applications.

T cell-derived Lymphotoxin is Essential for anti-HSV-1 Humoral Immune Response.

PubMed

Yang, Kaiting; Liang, Yong; Sun, Zhichen; Xue, Diyuan; Xu, Hairong; Zhu, Mingzhao; Fu, Yang-Xin; Peng, Hua

2018-05-09

B cell-derived lymphotoxin (LT) is required for the development of follicular dendritic cell clusters for the formation of primary and secondary lymphoid follicles, but the role of T cell-derived LT in antibody response has not been well demonstrated. We observed that lymphotoxin-β-receptor (LTβR) signaling is essential for optimal humoral immune response and protection against an acute HSV-1 infection. Blocking the LTβR pathway caused poor maintenance of germinal center B (GC-B) cells and follicular helper T (Tfh) cells. Using bone marrow chimeric mice and adoptive transplantation, we determined that T cell-derived LT played an indispensable role in the humoral immune response to HSV-1. Up-regulation of IFNγ by the LTβR-Ig blockade impairs the sustainability of Tfh-like cells, thus leading to an impaired humoral immune response. Our findings have identified a novel role of T cell-derived LT in the humoral immune response against HSV-1 infection. IMPORTANCE Immunocompromised people are susceptible for HSV-1 infection and lethal recurrence, which could be inhibited by anti-HSV-1 humoral immune response in the host. This study sought to explore the role of T cell-derived LT in the anti-HSV-1 humoral immune response using LT-LTβR signaling deficient mice and the LTβR-Ig blockade. The data indicate that the T cell-derived LT may play an essential role in sustaining Tfh-like cells and ensure Tfh-like cells' migration into primary or secondary follicles for further maturation. This study provides insights for vaccine development against infectious diseases. Copyright © 2018 American Society for Microbiology.

Human body shape index based on an experimentally derived model of human growth.

PubMed

Lebiedowska, Maria K; Alter, Katharine E; Stanhope, Steven J

2008-01-01

To test the assumption of geometrically similar growth by developing experimentally derived models of human body growth during the age interval of 5 to 18 years; to use these derived growth models to establish a new human body shape index (HBSI) based on natural age-related changes in human body shape (HBS); and to compare various metrics of relative body weight (body mass index [BMI], ponderal index [PI], and HBSI) in a sample of 5- to 18-year-old children. Nondisabled Polish children (n = 847) participated in this descriptive study. To model growth, the best fit between body height (H) and body mass (M) was calculated for each sex using the allometric equation M = m(i) H(chi). HBSI was calculated separately for girls and boys, using sex-specific values for chi and a general HBSI from combined data. The customary BMI and PI were calculated and compared with HBSI values. The models of growth were M = 13.11H(2.84) (R2 = 0.90) for girls and M = 13.64H(2.68) (R2 = 0.91) for boys. HBSI values contained less inherent variability and were less influenced by growth (age and height) compared with BMI and PI. Age-related growth during childhood is sex-specific and not geometrically similar. Therefore, indices of HBS formulated from experimentally derived models of human growth are superior to customary geometric similarity-based indices for characterizing HBS in children during the formative growth years.

tRF2Cancer: A web server to detect tRNA-derived small RNA fragments (tRFs) and their expression in multiple cancers.

PubMed

Zheng, Ling-Ling; Xu, Wei-Lin; Liu, Shun; Sun, Wen-Ju; Li, Jun-Hao; Wu, Jie; Yang, Jian-Hua; Qu, Liang-Hu

2016-07-08

tRNA-derived small RNA fragments (tRFs) are one class of small non-coding RNAs derived from transfer RNAs (tRNAs). tRFs play important roles in cellular processes and are involved in multiple cancers. High-throughput small RNA (sRNA) sequencing experiments can detect all the cellular expressed sRNAs, including tRFs. However, distinguishing genuine tRFs from RNA fragments generated by random degradation remains a major challenge. In this study, we developed an integrated web-based computing system, tRF2Cancer, to accurately identify tRFs from sRNA deep-sequencing data and evaluate their expression in multiple cancers. The binomial test was introduced to evaluate whether reads from a small RNA-seq data set represent tRFs or degraded fragments. A classification method was then used to annotate the types of tRFs based on their sites of origin in pre-tRNA or mature tRNA. We applied the pipeline to analyze 10 991 data sets from 32 types of cancers and identified thousands of expressed tRFs. A tool called 'tRFinCancer' was developed to facilitate the users to inspect the expression of tRFs across different types of cancers. Another tool called 'tRFBrowser' shows both the sites of origin and the distribution of chemical modification sites in tRFs on their source tRNA. The tRF2Cancer web server is available at http://rna.sysu.edu.cn/tRFfinder/. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Monitoring the Softening of Aluminum-Alloy V95ochT2 Shapes by a Nondestructive Method

NASA Astrophysics Data System (ADS)

Shigapov, A. I.; Klimova, T. A.; Il'inkova, T. A.

2015-09-01

Correlation relations between the strength and the electrical conductivity of aluminum shapes are determined. The properties of alloy V95ochT2 are studied after different temperature-and-time actions. It is shown that the "dark spots" appearing on the surface of such shapes can be evaluated by a nondestructive eddy-current method.

Design of High Performance Si/SiGe Heterojunction Tunneling FETs with a T-Shaped Gate

NASA Astrophysics Data System (ADS)

Li, Wei; Liu, Hongxia; Wang, Shulong; Chen, Shupeng; Yang, Zhaonian

2017-03-01

In this paper, a new Si/SiGe heterojunction tunneling field-effect transistor with a T-shaped gate (HTG-TFET) is proposed and investigated by Silvaco-Atlas simulation. The two source regions of the HTG-TFET are placed on both sides of the gate to increase the tunneling area. The T-shaped gate is designed to overlap with N+ pockets in both the lateral and vertical directions, which increases the electric field and tunneling rate at the top of tunneling junctions. Moreover, using SiGe in the pocket regions leads to the smaller tunneling distance. Therefore, the proposed HTG-TFET can obtain the higher on-state current. The simulation results show that on-state current of HTG-TFET is increased by one order of magnitude compared with that of the silicon-based counterparts. The average subthreshold swing (SS) of HTG-TFET is 44.64 mV/dec when V g is varied from 0.1 to 0.4 V, and the point SS is 36.59 mV/dec at V g = 0.2 V. Besides, this design cannot bring the sever Miller capacitance for the TFET circuit design. By using the T-shaped gate and SiGe pocket regions, the overall performance of the TFET is optimized.

Design of High Performance Si/SiGe Heterojunction Tunneling FETs with a T-Shaped Gate.

PubMed

Li, Wei; Liu, Hongxia; Wang, Shulong; Chen, Shupeng; Yang, Zhaonian

2017-12-01

In this paper, a new Si/SiGe heterojunction tunneling field-effect transistor with a T-shaped gate (HTG-TFET) is proposed and investigated by Silvaco-Atlas simulation. The two source regions of the HTG-TFET are placed on both sides of the gate to increase the tunneling area. The T-shaped gate is designed to overlap with N + pockets in both the lateral and vertical directions, which increases the electric field and tunneling rate at the top of tunneling junctions. Moreover, using SiGe in the pocket regions leads to the smaller tunneling distance. Therefore, the proposed HTG-TFET can obtain the higher on-state current. The simulation results show that on-state current of HTG-TFET is increased by one order of magnitude compared with that of the silicon-based counterparts. The average subthreshold swing (SS) of HTG-TFET is 44.64 mV/dec when V g is varied from 0.1 to 0.4 V, and the point SS is 36.59 mV/dec at V g  = 0.2 V. Besides, this design cannot bring the sever Miller capacitance for the TFET circuit design. By using the T-shaped gate and SiGe pocket regions, the overall performance of the TFET is optimized.

Control of single-photon routing in a T-shaped waveguide by another atom

NASA Astrophysics Data System (ADS)

Huang, Jin-Song; Wang, Jing-Wen; Wang, Yan; Li, Yan-Ling; Huang, You-Wen

2018-04-01

Quantum routers with a high routing rate of much more than 0.5 are of great importance for quantum networks. We provide a scheme to perform bidirectional high routing-rate transfer in a T-shaped coupled-resonator waveguide (CRW), which extends a recent unidirectional scheme proposed by Lu et al. (Opt Express 23:22955, 2015). By locating an extra two-level atom in the infinite CRW channel of the T-shaped CRW with a three-level system, an effective potential is generated. Our numerical results show that high routing capability from the infinite CRW channel to the semi-infinite channel can be achieved, and routing capability from the semi-infinite CRW channel to the infinite channel can also be significantly enhanced, with the help of the effective potential. Therefore, the proposed double-atom configuration could be utilized as a bidirectional quantum routing controller to implement high transfer rate routing of single photons.

Numerical Modeling of Surface and Volumetric Cooling using Optimal T- and Y-shaped Flow Channels

NASA Astrophysics Data System (ADS)

Kosaraju, Srinivas

2017-11-01

The layout of T- and V-shaped flow channel networks on a surface can be optimized for minimum pressure drop and pumping power. The results of the optimization are in the form of geometric parameters such as length and diameter ratios of the stem and branch sections. While these flow channels are optimized for minimum pressure drop, they can also be used for surface and volumetric cooling applications such as heat exchangers, air conditioning and electronics cooling. In this paper, an effort has been made to study the heat transfer characteristics of multiple T- and Y-shaped flow channel configurations using numerical simulations. All configurations are subjected to same input parameters and heat generation constraints. Comparisons are made with similar results published in literature.

Damage localization by statistical evaluation of signal-processed mode shapes

NASA Astrophysics Data System (ADS)

Ulriksen, M. D.; Damkilde, L.

2015-07-01

Due to their inherent, ability to provide structural information on a local level, mode shapes and t.lieir derivatives are utilized extensively for structural damage identification. Typically, more or less advanced mathematical methods are implemented to identify damage-induced discontinuities in the spatial mode shape signals, hereby potentially facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement, noise. The present, article introduces a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement, noise. The method is based on signal processing of spatial mode shapes by means of continuous wavelet, transformation (CWT) and subsequent, application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact, damage-induced, outlier analysis of principal components of the signal-processed mode shapes is conducted on the basis of T2-statistics. The proposed method is demonstrated in the context, of analytical work with a free-vibrating Euler-Bernoulli beam under noisy conditions.

Human Atopic Dermatitis Skin-derived T Cells can Induce a Reaction in Mouse Keratinocytes in vivo.

PubMed

Martel, B C; Blom, L; Dyring-Andersen, B; Skov, L; Thestrup-Pedersen, K; Skov, S; Skak, K; Poulsen, L K

2015-08-01

In atopic dermatitis (AD), the inflammatory response between skin-infiltrating T cells and keratinocytes is fundamental to the development of chronic lesional eczema. The aim of this study was to investigate whether skin-derived T cells from AD patients could induce an inflammatory response in mice through keratinocyte activation and consequently cause the development of eczematous lesions. Punch biopsies of the lesional skin from AD patients were used to establish skin-derived T cell cultures, which were transferred to NOD.Cg-Prkd(scid) Il2rg(tm1Sug) /JicTac (NOG) mice. We found that the subcutaneous injection of the human AD skin-derived T cells resulted in the migration of the human T cells from subcutis to the papillary dermis followed by the development of erythema and oedema in the mouse skin. Furthermore, the human T cells induced a transient proliferative response in the mouse keratinocytes shown as increased numbers of Ki-67(+) keratinocytes and increased epidermal thickness. Out of six established AD skin-derived T cell cultures, two were superior at inducing a skin reaction in the mice, and these cultures were found to contain >10% CCR10(+) T cells compared to <2% for the other cultures. In comparison, blood-derived in vitro-differentiated Th2 cells only induced a weak response in a few of the mice. Thus, we conclude that human AD skin-derived T cells can induce a reaction in the mouse skin through the induction of a proliferative response in the mouse keratinocytes. © 2015 The Foundation for the Scandinavian Journal of Immunology.

A protocol for the creation of useful geometric shape metrics illustrated with a newly derived geometric measure of leaf circularity.

PubMed

Krieger, Jonathan D

2014-08-01

I present a protocol for creating geometric leaf shape metrics to facilitate widespread application of geometric morphometric methods to leaf shape measurement. • To quantify circularity, I created a novel shape metric in the form of the vector between a circle and a line, termed geometric circularity. Using leaves from 17 fern taxa, I performed a coordinate-point eigenshape analysis to empirically identify patterns of shape covariation. I then compared the geometric circularity metric to the empirically derived shape space and the standard metric, circularity shape factor. • The geometric circularity metric was consistent with empirical patterns of shape covariation and appeared more biologically meaningful than the standard approach, the circularity shape factor. The protocol described here has the potential to make geometric morphometrics more accessible to plant biologists by generalizing the approach to developing synthetic shape metrics based on classic, qualitative shape descriptors.

Accuracy of the domain method for the material derivative approach to shape design sensitivities

NASA Technical Reports Server (NTRS)

Yang, R. J.; Botkin, M. E.

1987-01-01

Numerical accuracy for the boundary and domain methods of the material derivative approach to shape design sensitivities is investigated through the use of mesh refinement. The results show that the domain method is generally more accurate than the boundary method, using the finite element technique. It is also shown that the domain method is equivalent, under certain assumptions, to the implicit differentiation approach not only theoretically but also numerically.

Bounded solutions in a T-shaped waveguide and the spectral properties of the Dirichlet ladder

NASA Astrophysics Data System (ADS)

Nazarov, S. A.

2014-08-01

The Dirichlet problem is considered on the junction of thin quantum waveguides (of thickness h ≪ 1) in the shape of an infinite two-dimensional ladder. Passage to the limit as h → +0 is discussed. It is shown that the asymptotically correct transmission conditions at nodes of the corresponding one-dimensional quantum graph are Dirichlet conditions rather than the conventional Kirchhoff transmission conditions. The result is obtained by analyzing bounded solutions of a problem in the T-shaped waveguide that the boundary layer phenomenon.

Targeting Peripheral-Derived Regulatory T Cells as a Means of Enhancing Immune Responses Directed against Prostate Cancer

DTIC Science & Technology

2017-08-01

Award Number: W81XWH-15-1-0328 TITLE: Targeting Peripheral-Derived Regulatory T Cells as a Means of Enhancing Immune Responses Directed against...1 August 2016 - 31 July 2017 4. TITLE AND SUBTITLE Targeting Peripheral-Derived Regulatory T Cells as a Means of Enhancing Immune Responses Directed...discovered that a subset of regulatory T cells (Tregs), termed peripheral-derived Tregs (pTregs), impair immune responses directed against tumor

Nanofabrication of 10-nm T-shaped gates using a double patterning process with electron beam lithography and dry etch

NASA Astrophysics Data System (ADS)

Shao, Jinhai; Deng, Jianan; Lu, W.; Chen, Yifang

2017-07-01

A process to fabricate T-shaped gates with the footprint scaling down to 10 nm using a double patterning procedure is reported. One of the keys in this process is to separate the definition of the footprint from that for the gate-head so that the proximity effect originated from electron forward scattering in the resist is significantly minimized, enabling us to achieve as narrow as 10-nm foot width. Furthermore, in contrast to the reported technique for 10-nm T-shaped profile in resist, this process utilizes a metallic film with a nanoslit as an etch mask to form a well-defined 10-nm-wide foot in a SiNx layer by reactive ion etch. Such a double patterning process has demonstrated enhanced reliability. The detailed process is comprehensively described, and its advantages and limitations are discussed. Nanofabrication of InP-based high-electron-mobility transistors using the developed process for 10- to 20-nm T-shaped gates is currently under the way.

Revisiting the Acanthamoeba species that form star-shaped cysts (genotypes T7, T8, T9, and T17): characterization of seven new Brazilian environmental isolates and phylogenetic inferences.

PubMed

Magliano, Ana C M; Teixeira, Marta M G; Alfieri, Silvia C

2012-01-01

Free-living amoebae of the genus Acanthamoeba are the agents of both opportunistic and non-opportunistic infections and are frequently isolated from the environment. Of the 17 genotypes (T1-T17) identified thus far, 4 (T7, T8, T9, and T17) accommodate the rarely investigated species of morphological group I, those that form large, star-shaped cysts. We report the isolation and characterization of 7 new Brazilian environmental Acanthamoeba isolates, all assigned to group I. Phylogenetic analyses based on partial (~1200 bp) SSU rRNA gene sequences placed the new isolates in the robustly supported clade composed of the species of morphological group I. One of the Brazilian isolates is closely related to A. comandoni (genotype T9), while the other 6, together with 2 isolates recently assigned to genotype T17, form a homogeneous, well-supported group (2·0% sequence divergence) that likely represents a new Acanthamoeba species. Thermotolerance, osmotolerance, and cytophatic effects, features often associated with pathogenic potential, were also examined. The results indicated that all 7 Brazilian isolates grow at temperatures up to 40°C, and resist under hyperosmotic conditions. Additionally, media conditioned by each of the new Acanthamoeba isolates induced the disruption of SIRC and HeLa cell monolayers.

Prior Dengue Virus Exposure Shapes T Cell Immunity to Zika Virus in Humans

PubMed Central

Grifoni, Alba; Pham, John; Sidney, John; O'Rourke, Patrick H.; Paul, Sinu; Peters, Bjoern; Martini, Sheridan R.; de Silva, Aruna D.; Ricciardi, Michael J.; Silveira, Cassia G. T.; Maestri, Alvino; Costa, Priscilla R.; de-Oliveira-Pinto, Luzia Maria; de Azeredo, Elzinandes Leal; Damasco, Paulo Vieira; Phillips, Elizabeth; Mallal, Simon; de Silva, Aravinda M.; Collins, Matthew; Durbin, Anna; Diehl, Sean A.; Cerpas, Cristhiam; Balmaseda, Angel; Kuan, Guillermina; Coloma, Josefina; Harris, Eva; Crowe, James E.; Stone, Mars; Busch, Michael; Vivanco-Cid, Hector; Cox, Josephine; Graham, Barney S.; Ledgerwood, Julie E.; Turtle, Lance; Solomon, Tom; Kallas, Esper G.; Watkins, David I.; Weiskopf, Daniela

2017-01-01

ABSTRACT While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here, we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether preexisting dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with tetravalent dengue attenuated vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors but declines in DENV-preexposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells from DENV-preexposed donors selectively upregulated granzyme B and PD1, unlike DENV-naive donors. Finally, we discovered that ZIKV structural proteins (E, prM, and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins. IMPORTANCE The issue of potential ZIKV and DENV cross-reactivity and how preexisting DENV T cell immunity modulates Zika T cell responses is of great relevance, as the two viruses often cocirculate and Zika virus has been spreading in geographical regions where DENV is endemic or hyperendemic. Our data show that memory T cell responses elicited by prior

The T-Shaped Graduate

ERIC Educational Resources Information Center

Ramaswami, Rama

2009-01-01

As President Obama said in advance remarks about the American Graduation Initiative: "[T]he hard truth is that some of the jobs that have been lost in the auto industry and elsewhere won't be coming back. And that only underscores the importance of generating new businesses and industries to replace the ones we've lost, and of preparing our…

A net-shaped multicellular formation facilitates the maturation of hPSC-derived cardiomyocytes through mechanical and electrophysiological stimuli

PubMed Central

Liu, Taoyan; Huang, Chengwu; Li, Hongxia; Wu, Fujian; Luo, Jianwen; Lu, Wenjing

2018-01-01

The use of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) is limited in drug discovery and cardiac disease mechanism studies due to cell immaturity. Although many approaches have been reported to improve the maturation of hiPSC-CMs, the elucidation of the process of maturation is crucial. We applied a small-molecule-based differentiation method to generate cardiomyocytes (CMs) with multiple aggregation forms. The motion analysis revealed significant physical differences in the differently shaped CMs, and the net-shaped CMs had larger motion amplitudes and faster velocities than the sheet-shaped CMs. The net-shaped CMs displayed accelerated maturation at the transcriptional level and were more similar to CMs with a prolonged culture time (30 days) than to sheet-d15. Ion channel genes and gap junction proteins were up-regulated in net-shaped CMs, indicating that robust contraction was coupled with enhanced ion channel and connexin expression. The net-shaped CMs also displayed improved myofibril ultrastructure under transmission electron microscopy. In conclusion, different multicellular hPSC-CM structures, such as the net-shaped pattern, are formed using the conditioned induction method, providing a useful tool to improve cardiac maturation. PMID:29661985

Shaping tRNA

ERIC Educational Resources Information Center

Priano, Christine

2013-01-01

This model-building activity provides a quick, visual, hands-on tool that allows students to examine more carefully the cloverleaf structure of a typical tRNA molecule. When used as a supplement to lessons that involve gene expression, this exercise reinforces several concepts in molecular genetics, including nucleotide base-pairing rules, the…

Prior Dengue virus exposure shapes T cell immunity to Zika virus in humans.

PubMed

Grifoni, Alba; Pham, John; Sidney, John; O'Rourke, Patrick H; Paul, Sinu; Peters, Bjoern; Martini, Sheridan R; de Silva, Aruna D; Ricciardi, Michael J; Magnani, Diogo M; Silveira, Cassia G T; Maestri, Alvino; Costa, Priscilla R; de-Oliveira-Pinto, Luzia Maria; de Azeredo, Elzinandes Leal; Damasco, Paulo Vieira; Phillips, Elizabeth; Mallal, Simon; de Silva, Aravinda M; Collins, Matthew; Durbin, Anna; Diehl, Sean A; Cerpas, Cristhiam; Balmaseda, Angel; Kuan, Guillermina; Coloma, Josefina; Harris, Eva; Crowe, James E; Stone, Mars; Norris, Phillip J; Busch, Michael; Vivanco-Cid, Hector; Cox, Josephine; Graham, Barney S; Ledgerwood, Julie E; Turtle, Lance; Solomon, Tom; Kallas, Esper G; Watkins, David I; Weiskopf, Daniela; Sette, Alessandro

2017-10-04

While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether pre-existing dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with Tetravalent Dengue Attenuated Vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors, but declines in DENV pre-exposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells form DENV pre-exposed donors selectively up-regulated granzyme B and PD1, as compared to DENV-naïve donors. Finally, we discovered that ZIKV structural proteins (E, prM and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins. IMPORTANCE The issue of potential ZIKV and DENV cross-reactivity and how pre-existing DENV T cell immunity modulates ZIKA T cell responses is of great relevance as the two viruses often co-circulate and ZIKA virus has been spreading in geographical regions where DENV is endemic or hyper-endemic. Our data show that memory T cell responses elicited by

Gut-derived lipopolysaccharide promotes T-cell-mediated hepatitis in mice through Toll-like receptor 4.

PubMed

Lin, Yan; Yu, Le-Xing; Yan, He-Xin; Yang, Wen; Tang, Liang; Zhang, Hui-Lu; Liu, Qiong; Zou, Shan-Shan; He, Ya-Qin; Wang, Chao; Wu, Meng-Chao; Wang, Hong-Yang

2012-09-01

Robust clinical and epidemiologic data support the role of inflammation as a key player in hepatocellular carcinoma (HCC) development. Our previous data showed that gut-derived lipopolysaccharide (LPS) promote HCC development by activating Toll-like receptor 4 (TLR4) expressed on myeloid-derived cells. However, the effects of gut-derived LPS on other types of liver injury models are yet to be studied. The purpose of this study was to determine the importance of gut-derived LPS and TLR4 signaling in a T-cell-mediated hepatitis-Con A-induced hepatitis model, which mimic the viral hepatitis. Reduction of endotoxin using antibiotics regimen or genetic ablation of TLR4 in mice significantly alleviate Con A-induced liver injury by inhibiting the infiltration of T lymphocytes into the liver and the activation of CD4(+) T lymphocytes as well as the production of T helper 1 cytokines; in contrast, exogenous LPS can promote Con A-induced hepatitis and CD4(+) T cells activation in vivo and in vitro. Reconstitution of TLR4-expressing myeloid cells in TLR4-deficient mice restored Con A-induced liver injury and inflammation, indicating the major cell target of LPS. In addition, TLR4 may positively regulate the target hepatocellular apoptosis via the perforin/granzyme B pathway. These data suggest that gut-derived LPS and TLR4 play important positive roles in Con A-induced hepatitis and modulation of the gut microbiotia may represent a new avenue for therapeutic intervention to treat acute hepatitis induced by hepatitis virus infection, thus to prevent hepatocellular carcinoma.

Effect of Biodegradable Shape-Memory Polymers on Proliferation of 3T3 Cells

NASA Astrophysics Data System (ADS)

Xu, Shuo-Gui; Zhang, Peng; Zhu, Guang-Ming; Jiang, Ying-Ming

2011-07-01

This article evaluates the in vitro biocompatibility for biodegradable shape-memory polymers (BSMP) invented by the authors. 3T3 cells (3T3-Swiss albino GNM 9) of primary and passaged cultures were inoculated into two kinds of carriers: the BSMP carrier and the control group carrier. Viability, proliferation, and DNA synthesis (the major biocompatibility parameters), were measured and evaluated for both the BSMP and naked carrier via cell growth curve analysis, MTT colorimetry and addition of 3H-TdR to culture media. The results showed that there was no difference between the BSMP carrier and the control dish in terms of viability, proliferation, and metabolism of the 3T3 cells. Overall, the BSMP carrier provides good biocompatibility and low toxicity to cells in vitro, and could indicate future potential for this medium as a biological material for implants in vivo.

Melissopalynological and volatile analysis of honeys from Corsican Arbutus unedo habitat.

PubMed

Yang, Yin; Battesti, Marie-José; Costa, Jean; Paolini, Julien

2014-10-01

Thirty Corsican "autumn maquis" honeys were characterized by the typical combination of autumnal taxa: Arbutus unedo, Hedera helix, Smilax aspera, Rosmarinus officinalis, and two Asteraceae pollen forms. Corsican origin was characterized by the diversity of the taxa's biogeographical origins and significant presence of Castanea sativa and Quercus sp. Volatile fractions of "autumn maquis" honeys were dominated by isophorone and 3,4,5-trimethylphenol. The latter is reported in A. unedo honey for the first time. Otherwise, both A. unedo flower and "autumn maquis" honeys exhibited high contents of isophorone derivatives. H. helix honey exhibited phenylacetaldehyde, benzyl nitrile, 3-hydroxy-4-phenylbutan-2-one and nonanal as major compounds, which were scarcely represented in the studied "autumn maquis" honey samples.

Stability and sensitivity analyses of the engulfment regime in a three dimensional T-shaped micromixer

NASA Astrophysics Data System (ADS)

Fani, Andrea; Camarri, Simone; Galletti, Chiara; Salvetti, Maria Vittoria

2012-11-01

The recent research in micro-fluidics has focused on the development of efficient passive micromixers, in which mixing is promoted without the help of any external power. One among the simplest designs of a passive micromixer is a T shape, in which the inlets join the main channel with T-shaped branches. The range of Reynolds numbers, Re , of interest for practical applications is such that the flow inside such a mixer is laminar but it is characterized by peculiar fluid-dynamics instabilities, which significantly enhance mixing but are poorly investigated in the literature. As Re is increased, the flow goes through a bifurcation which drives the system from a perfectly symmetric flow to a steady but asymmetric state, so enhancing mixing (engulfment regime). The onset of the engulfment has been found to be influenced by geometrical parameters and by inflow conditions. In the present work we characterize the engulfment instability by a global stability analysis on the 3D base flow in a T-mixer. Sensitivity analyses with respect to a structural perturbation of the linearized flow equations and to a base flow modification were carried out. Finally, we characterize the sensitivity of the considered instability with respect to a perturbation of the inlet velocity profile.

Galacturonomannan and Golgi-derived membrane linked to growth and shaping of biogenic calcite

NASA Technical Reports Server (NTRS)

Marsh, M. E.; Ridall, A. L.; Azadi, P.; Duke, P. J.

2002-01-01

The coccolithophores are valuable models for the design and synthesis of composite materials, because the cellular machinery controlling the nucleation, growth, and patterning of their calcitic scales (coccoliths) can be examined genetically. The coccoliths are formed within the Golgi complex and are the major CaCO(3) component in limestone sediments-particularly those of the Cretaceous period. In this study, we describe mutants lacking a sulfated galacturonomannan and show that this polysaccharide in conjunction with the Golgi-derived membrane is directly linked to the growth and shaping of coccolith calcite but not to the initial orientated nucleation of the mineral phase.

Phenotypic characterization of glioblastoma identified through shape descriptors

NASA Astrophysics Data System (ADS)

Chaddad, Ahmad; Desrosiers, Christian; Toews, Matthew

2016-03-01

This paper proposes quantitatively describing the shape of glioblastoma (GBM) tissue phenotypes as a set of shape features derived from segmentations, for the purposes of discriminating between GBM phenotypes and monitoring tumor progression. GBM patients were identified from the Cancer Genome Atlas, and quantitative MR imaging data were obtained from the Cancer Imaging Archive. Three GBM tissue phenotypes are considered including necrosis, active tumor and edema/invasion. Volumetric tissue segmentations are obtained from registered T1˗weighted (T1˗WI) postcontrast and fluid-attenuated inversion recovery (FLAIR) MRI modalities. Shape features are computed from respective tissue phenotype segmentations, and a Kruskal-Wallis test was employed to select features capable of classification with a significance level of p < 0.05. Several classifier models are employed to distinguish phenotypes, where a leave-one-out cross-validation was performed. Eight features were found statistically significant for classifying GBM phenotypes with p <0.05, orientation is uninformative. Quantitative evaluations show the SVM results in the highest classification accuracy of 87.50%, sensitivity of 94.59% and specificity of 92.77%. In summary, the shape descriptors proposed in this work show high performance in predicting GBM tissue phenotypes. They are thus closely linked to morphological characteristics of GBM phenotypes and could potentially be used in a computer assisted labeling system.

Giant T-shaped duplication of the transverse colon. A case report.

PubMed

Trotovsek, Blaz; Hribernik, Marija; Gvardijancic, Diana; Jelenc, Franc

2006-01-01

A case of long diverticular colonic duplication producing acute abdominal pain in a 6-year-old girl is presented. Physical examination showed no signs of acute abdomen at the initial presentation. After a pain-free interval, there was a sudden onset of severe abdominal pain and a large tumor in the lower abdomen was observed. A plain x-ray showed an enormously dilated colonic pouch filled with gas. Excision of the T-shaped duplication and small part of the transverse colon was successful. Because of extensive fibrotic changes in the colon near the opening of duplication, a resection margin of at least 2 cm is recommended.

Beam shaping assembly of a D-T neutron source for BNCT and its dosimetry simulation in deeply-seated tumor

NASA Astrophysics Data System (ADS)

Faghihi, F.; Khalili, S.

2013-08-01

This article involves two aims for BNCT. First case includes a beam shaping assembly estimation for a D-T neutron source to find epi-thermal neutrons which are the goal in the BNCT. Second issue is the percent depth dose calculation in the adult Snyder head phantom. Monte-Carlo simulations and verification of a suggested beam shaping assembly (including internal neutron multiplier, moderator, filter, external neutron multiplier, collimator, and reflector dimensions) for thermalizing a D-T neutron source as well as increasing neutron flux are carried out and our results are given herein. Finally, we have simulated its corresponding doses for treatment planning of a deeply-seated tumor.

Use of cord blood derived T-cells in cancer immunotherapy: milestones achieved and future perspectives.

PubMed

Lo Presti, Vania; Nierkens, Stefan; Boelens, Jaap Jan; van Til, Niek P

2018-03-01

Hematopoietic cell transplantation is a potentially lifesaving procedure for patients with hematological malignancies who are refractory to conventional chemotherapy and/or irradiation treatment. Umbilical cord blood (CB) transplantation, as a hematopoietic stem and progenitor cell (HSPC) source, has several advantages over bone marrow transplantation with respect to matching and prompt availability for transplantation. Additionally, CB has some inherent features, such as rapid expansion of T cells, lower prevalence of graft-versus-host disease and higher graft versus tumor efficacy that make this HSPC cell source more favorable over other HSPC sources. Areas covered: This review summarizes the current CB and CB derived T cell applications aiming to better disease control for hematological malignancies and discusses future directions to more effective therapies. Expert commentary: CB transplantation could be used as a platform to extract cord blood derived T cells for ex vivo expansion and/or gene modification to improve cellular immunotherapies. In addition, combining cord blood gene-engineered T cell products with vaccination strategies, such as cord blood derived dendritic cell based vaccines, may provide synergistic immunotherapies with enhanced anti-tumor effects.

Mixing in a T-shaped micromixer at moderate Reynolds numbers

NASA Astrophysics Data System (ADS)

Minakov, A. V.; Rudyak, V. Ya.; Gavrilov, A. A.; Dekterev, A. A.

2012-09-01

In the present work, the regimes of the flow and mixing of fluids in a T-shaped micromixer in the range of the Reynolds numbers from 1 to 1000 are investigated systematically with the aid of numerical modeling. The flow and mixing regimes are shown to alter substantially with increasing Reynolds numbers. Five different flow regimes have been identified in the total. The dependencies of the friction coefficient and mixing efficiency on the Reynolds number are obtained. A sharp increase in the mixing efficiency at a flow transition from the symmetric to asymmetric steady regime is shown. On the other hand, the mixing efficiency slightly drops in the laminar-turbulent transition region. A substantial influence of the slip presence on walls on flow structure in the channel and mixing efficiency has been revealed.

Development of T m -shift genotyping method for detection of cat-derived Giardia lamblia.

PubMed

Pan, Weida; Fu, Yeqi; Abdullahi, Auwalu Yusuf; Wang, Mingwei; Shi, Xianli; Yang, Fang; Yu, Xingang; Yan, Xinxin; Zhang, Pan; Hang, Jianxiong; Li, Guoqing

2017-04-01

To develop T m -shift genotyping method for detection of cat-derived Giardia lamblia, two sets of primers with two GC-rich tails of unequal length attached to their 5'-end were designed according to two SNPs (BG434 and BG170) of β-giardin (bg) gene, and specific PCR products were identified by inspection of a melting curve on real-time PCR thermocycler. A series of experiments on the stability, sensitivity, and accuracy of T m -shift method was tested, and clinical samples were also detected. The results showed that two sets of primers based on SNP could distinguish accurately between assemblages A and F. Coefficient of variation of T m values of assemblage A and F was 0.14 and 0.07% in BG434 and 0.10 and 0.11% in BG170, respectively. The lowest detection concentration was 4.52 × 10 -5 and 4.88 × 10 -5  ng/μL samples of assemblage A and F standard plasmids. The T m -shift genotyping results of ten DNA samples from the cat-derived G. lamblia were consistent with their known genotypes. The detection rate of clinical samples by T m -shift was higher than that by microscopy, and their genotyping results were in complete accordance with sequencing results. It is concluded that the T m -shift genotyping method is rapid, specific, and sensitive and may provide a new technological mean for molecular detection and epidemiological investigation of the cat-derived G. lamblia.

Dielectric Boundary Force in Molecular Solvation with the Poisson–Boltzmann Free Energy: A Shape Derivative Approach

PubMed Central

Li, Bo; Cheng, Xiaoliang; Zhang, Zhengfang

2013-01-01

In an implicit-solvent description of molecular solvation, the electrostatic free energy is given through the electrostatic potential. This potential solves a boundary-value problem of the Poisson–Boltzmann equation in which the dielectric coefficient changes across the solute-solvent interface—the dielectric boundary. The dielectric boundary force acting on such a boundary is the negative first variation of the electrostatic free energy with respect to the location change of the boundary. In this work, the concept of shape derivative is used to define such variations and formulas of the dielectric boundary force are derived. It is shown that such a force is always in the direction toward the charged solute molecules. PMID:24058212

Linearized T-Matrix and Mie Scattering Computations

NASA Technical Reports Server (NTRS)

Spurr, R.; Wang, J.; Zeng, J.; Mishchenko, M. I.

2011-01-01

We present a new linearization of T-Matrix and Mie computations for light scattering by non-spherical and spherical particles, respectively. In addition to the usual extinction and scattering cross-sections and the scattering matrix outputs, the linearized models will generate analytical derivatives of these optical properties with respect to the real and imaginary parts of the particle refractive index, and (for non-spherical scatterers) with respect to the ''shape'' parameter (the spheroid aspect ratio, cylinder diameter/height ratio, Chebyshev particle deformation factor). These derivatives are based on the essential linearity of Maxwell's theory. Analytical derivatives are also available for polydisperse particle size distribution parameters such as the mode radius. The T-matrix formulation is based on the NASA Goddard Institute for Space Studies FORTRAN 77 code developed in the 1990s. The linearized scattering codes presented here are in FORTRAN 90 and will be made publicly available.

The consequences of the intracellular retention of pathogen-derived T-cell-independent antigens on protein presentation to T cells.

PubMed

Leyva-Cobián, F; Outschoorn, I M; Carrasco-Marín, E; Alvarez-Domínguez, C

1997-10-01

Intracellular pathogens can be considered as particulate antigens chemically composed of a complex mixture of T-cell-dependent antigens (TD) (peptides and proteins) and T-cell-independent antigens (TI) (glycolipids and complex polysaccharides). A large range of saccharides (from oligosaccharides to complex polysaccharides) derived from pathogenic microorganisms are being isolated and characterized. They are currently implicated in signaling systems and concomitant host-parasite relationships. However, there are not many structure-function relationships described for these pathogens. This is particularly true of polysaccharides. In this report we have reviewed the role of defined TI antigens in the processing and presentation of defined TD antigens to specific T cells by antigen-presenting cells (APC). We also considered the importance of some of the chemical characteristics shared by different carbohydrates implicated in the inhibition of antigen presentation. These findings are discussed in relation to the clear immunopathological consequences of long retention periods of complex carbohydrate molecules derived from intracellular parasites inside certain APC and the absence of antigen presentation impairment in physiological situations such as the removal of senescent or damaged red blood cells by splenic macrophages or intracellular accumulation of carbohydrates in colostrum and milk macrophages during lactation.

The Polyomavirus BK Large T-Antigen-Derived Peptide Elicits an HLA-DR Promiscuous and Polyfunctional CD4+ T-Cell Response▿

PubMed Central

Ramaswami, Bala; Popescu, Iulia; Macedo, Camila; Luo, Chunqing; Shapiro, Ron; Metes, Diana; Chalasani, Geetha; Randhawa, Parmjeet S.

2011-01-01

BK virus (BKV) nephropathy and hemorrhagic cystitis are increasingly recognized causes of disease in renal and hematopoietic stem cell transplant recipients, respectively. Functional characterization of the immune response to BKV is important for clinical diagnosis, prognosis, and vaccine design. A peptide mix (PepMix) and overlapping (OPP) or random (RPP) peptide pools derived from BKV large T antigen (LTA) were used to restimulate 14-day-expanded peripheral blood mononuclear cells (PBMC) from 27 healthy control subjects in gamma interferon (IFN-γ)-specific enzyme-linked immunospot (ELISPOT) assays. A T-cell response to LTA PepMix was detected in 15/27 subjects. A response was frequently observed with peptides derived from the helicase domain (9/15 subjects), while the DNA binding and host range domains were immunologically inert (0/15 subjects). For all nine subjects who responded to LTA peptide pools, the immune response could be explained largely by a 15-mer peptide designated P313. P313-specific CD4+ T-cell clones demonstrated (i) stringent LTA peptide specificity; (ii) promiscuous recognition in the context of HLA-DR alleles; (iii) cross recognition of homologous peptides from the polyomavirus simian virus 40 (SV40); (iv) an effector memory phenotype, CD107a expression, and intracellular production of IFN-γ and tumor necrosis factor alpha (TNF-α); (v) cytotoxic activity in a chromium release assay; and (vi) the ability to directly present cognate antigen to autologous T cells. In conclusion, T-cell-mediated immunity to BKV in healthy subjects is associated with a polyfunctional population of CD4+ T cells with dual T-helper and T-cytotoxic properties. HLA class II promiscuity in antigen presentation makes the targeted LTA peptide sequence a suitable candidate for inclusion in immunotherapy protocols. PMID:21367979

The polyomavirus BK large T-antigen-derived peptide elicits an HLA-DR promiscuous and polyfunctional CD4+ T-cell response.

PubMed

Ramaswami, Bala; Popescu, Iulia; Macedo, Camila; Luo, Chunqing; Shapiro, Ron; Metes, Diana; Chalasani, Geetha; Randhawa, Parmjeet S

2011-05-01

BK virus (BKV) nephropathy and hemorrhagic cystitis are increasingly recognized causes of disease in renal and hematopoietic stem cell transplant recipients, respectively. Functional characterization of the immune response to BKV is important for clinical diagnosis, prognosis, and vaccine design. A peptide mix (PepMix) and overlapping (OPP) or random (RPP) peptide pools derived from BKV large T antigen (LTA) were used to restimulate 14-day-expanded peripheral blood mononuclear cells (PBMC) from 27 healthy control subjects in gamma interferon (IFN-γ)-specific enzyme-linked immunospot (ELISPOT) assays. A T-cell response to LTA PepMix was detected in 15/27 subjects. A response was frequently observed with peptides derived from the helicase domain (9/15 subjects), while the DNA binding and host range domains were immunologically inert (0/15 subjects). For all nine subjects who responded to LTA peptide pools, the immune response could be explained largely by a 15-mer peptide designated P313. P313-specific CD4(+) T-cell clones demonstrated (i) stringent LTA peptide specificity; (ii) promiscuous recognition in the context of HLA-DR alleles; (iii) cross recognition of homologous peptides from the polyomavirus simian virus 40 (SV40); (iv) an effector memory phenotype, CD107a expression, and intracellular production of IFN-γ and tumor necrosis factor alpha (TNF-α); (v) cytotoxic activity in a chromium release assay; and (vi) the ability to directly present cognate antigen to autologous T cells. In conclusion, T-cell-mediated immunity to BKV in healthy subjects is associated with a polyfunctional population of CD4(+) T cells with dual T-helper and T-cytotoxic properties. HLA class II promiscuity in antigen presentation makes the targeted LTA peptide sequence a suitable candidate for inclusion in immunotherapy protocols.

Differential effects of HIV transmission from monocyte-derived dendritic cells vs. monocytes to IL-17+CD4+ T cells

PubMed Central

Mitsuki, Yu-ya; Tuen, Michael; Hioe, Catarina E.

2017-01-01

HIV infection leads to CD4 helper T cell (Th) loss, but not all Th cells are equally depleted. The contribution of other immune cells in the Th depletion also remains unclear. This study investigates HIV transmission from monocyte-derived dendritic cells (MDDCs) vs. monocytes to Th17 and Th1 cells using an allogeneic coculture model. The addition of HIV to MDDCs increased the expression of the negative regulatory molecule PD-L1 and decreased the expression of the activation markers HLA-DR and CD86, whereas the virus up-regulated HLA-DR and CD86, but not PD-L1, on monocytes. Coculturing of CD4+ T cells with MDDCs pretreated with HIV led to the decline of Th17, but not Th1, responses. In contrast, pretreatment of monocytes with HIV increased Th17 without affecting Th1 responses. The enhanced Th17 responses in the cocultures with HIV-treated monocytes were also accompanied by high numbers of virus-infected CD4+ T cells. The Th17 expansion arose from memory CD4+ T cells with minimal contribution from naïve CD4+ T cells. The Th17-enhancing activity was mediated by the HIV envelope and did not require productive virus infection. Comparison of MDDCs and monocytes further showed that, although HIV-treated MDDCs reduced Th proliferation and increased the activation of the apoptosis mediator caspase-3, HIV-treated monocytes enhanced Th proliferation without increasing the active caspase-3 levels. This study indicates the potential role of distinct myeloid cell populations in shaping Th17 responses during HIV infection. PMID:27531931

Hysteroscopic enlargement metroplasty for T-shaped uterus: 24 years' experience at the Strasbourg Medico-Surgical and Obstetrical Centre (CMCO).

PubMed

Ducellier-Azzola, G; Lecointre, L; Hummel, M; Pontvianne, M; Garbin, O

2018-05-12

What is the impact of hysteroscopic enlargement metroplasty for T-shaped uterus on the live birth rate? Performing enlargement metroplasty appears to improve the obstetrical prognosis and fertility in patients with a T-shaped uterus. T-shaped uterus is linked to an excess of myometrium in the uterine walls giving rise to a subcornual constriction ring which causes dysmorphism and hypoplasia of the uterine cavity. It is commonly associated with infertility or a sequence of repeated miscarriages. Single-centre observational cohort study in 112 patients who underwent enlargement metroplasty for T-shaped uterus between 1992 and 2016 in a Strasbourg university hospital centre. The mean age of patients was 33.2; they had been attempting to conceive on average for 56 months for subfertile patients and 42.2 months for infertile patients. Prior to surgery, patients had succeeded in becoming pregnant 161 times, i.e. a mean gravidity of 1.4 pregnancies. For subfertile patients the mean gravidity was 2.67. Mean parity was 0.04. In the overall population, one hundred pregnancies occurred following enlargement metroplasty. The live birth rate increased in a statistically significant manner following enlargement metroplasty: 4 (2.5%) vs. 60 (60%), p < 0.05. In parallel, the miscarriage rate was statistically reduced: 126 (78.3%) vs. 22 (22%), pnull< .05. Intraoperative complications were 1 case of cervical laceration (0.9%) and 1 case of false passage (0.9%). Subsequent pregnancies remained at risk of miscarriage (22%) and premature delivery (20%) but not extra uterine gestation. Delivery took place by Caesarean section in 61% of cases. In the subgroup of infertile patients, the live birth rate was also markedly increased and 49% of pregnancies which occurred were spontaneous. This study was descriptive and retrospective. These results are consistent with those in the literature. Hysteroscopic enlargement metroplasty is now a well-established technique with few

Automatized spleen segmentation in non-contrast-enhanced MR volume data using subject-specific shape priors

NASA Astrophysics Data System (ADS)

Gloger, Oliver; Tönnies, Klaus; Bülow, Robin; Völzke, Henry

2017-07-01

To develop the first fully automated 3D spleen segmentation framework derived from T1-weighted magnetic resonance (MR) imaging data and to verify its performance for spleen delineation and volumetry. This approach considers the issue of low contrast between spleen and adjacent tissue in non-contrast-enhanced MR images. Native T1-weighted MR volume data was performed on a 1.5 T MR system in an epidemiological study. We analyzed random subsamples of MR examinations without pathologies to develop and verify the spleen segmentation framework. The framework is modularized to include different kinds of prior knowledge into the segmentation pipeline. Classification by support vector machines differentiates between five different shape types in computed foreground probability maps and recognizes characteristic spleen regions in axial slices of MR volume data. A spleen-shape space generated by training produces subject-specific prior shape knowledge that is then incorporated into a final 3D level set segmentation method. Individually adapted shape-driven forces as well as image-driven forces resulting from refined foreground probability maps steer the level set successfully to the segment the spleen. The framework achieves promising segmentation results with mean Dice coefficients of nearly 0.91 and low volumetric mean errors of 6.3%. The presented spleen segmentation approach can delineate spleen tissue in native MR volume data. Several kinds of prior shape knowledge including subject-specific 3D prior shape knowledge can be used to guide segmentation processes achieving promising results.

Temperature derivatives for fusion reactivity of D-D and D-T

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langenbrunner, James R.; Makaruk, Hanna Ewa

Deuterium-tritium (D-T) and deuterium-deuterium (D-D) fusion reaction rates are observable using leakage gamma flux. A direct measurement of γ-rays with equipment that exhibits fast temporal response could be used to infer temperature, if the detector signal is amenable for taking the logarithmic time-derivative, alpha. We consider the temperature dependence for fusion cross section reactivity.

Therapeutic potential of CAR-T cell-derived exosomes: a cell-free modality for targeted cancer therapy.

PubMed

Tang, Xiang-Jun; Sun, Xu-Yong; Huang, Kuan-Ming; Zhang, Li; Yang, Zhuo-Shun; Zou, Dan-Dan; Wang, Bin; Warnock, Garth L; Dai, Long-Jun; Luo, Jie

2015-12-29

Chimeric antigen receptor (CAR)-based T-cell adoptive immunotherapy is a distinctively promising therapy for cancer. The engineering of CARs into T cells provides T cells with tumor-targeting capabilities and intensifies their cytotoxic activity through stimulated cell expansion and enhanced cytokine production. As a novel and potent therapeutic modality, there exists some uncontrollable processes which are the potential sources of adverse events. As an extension of this impactful modality, CAR-T cell-derived exosomes may substitute CAR-T cells to act as ultimate attackers, thereby overcoming some limitations. Exosomes retain most characteristics of parent cells and play an essential role in intercellular communications via transmitting their cargo to recipient cells. The application of CAR-T cell-derived exosomes will make this cell-based therapy more clinically controllable as it also provides a cell-free platform to diversify anticancer mediators, which responds effectively to the complexity and volatility of cancer. It is believed that the appropriate application of both cellular and exosomal platforms will make this effective treatment more practicable.

Versican-Derived Matrikines Regulate Batf3-Dendritic Cell Differentiation and Promote T Cell Infiltration in Colorectal Cancer.

PubMed

Hope, Chelsea; Emmerich, Philip B; Papadas, Athanasios; Pagenkopf, Adam; Matkowskyj, Kristina A; Van De Hey, Dana R; Payne, Susan N; Clipson, Linda; Callander, Natalie S; Hematti, Peiman; Miyamoto, Shigeki; Johnson, Michael G; Deming, Dustin A; Asimakopoulos, Fotis

2017-09-01

Colorectal cancer originates within immunologically complex microenvironments. To date, the benefits of immunotherapy have been modest, except in neoantigen-laden mismatch repair-deficient tumors. Approaches to enhance tumor-infiltrating lymphocytes in the tumor bed may substantially augment clinical immunotherapy responses. In this article, we report that proteolysis of the tolerogenic matrix proteoglycan versican (VCAN) strongly correlated with CD8 + T cell infiltration in colorectal cancer, regardless of mismatch repair status. Tumors displaying active VCAN proteolysis and low total VCAN were associated with robust (10-fold) CD8 + T cell infiltration. Tumor-intrinsic WNT pathway activation was associated with CD8 + T cell exclusion and VCAN accumulation. In addition to regulating VCAN levels at the tumor site, VCAN proteolysis results in the generation of bioactive fragments with novel functions (VCAN-derived matrikines). Versikine, a VCAN-derived matrikine, enhanced the generation of CD103 + CD11c hi MHCII hi conventional dendritic cells (cDCs) from Flt3L-mobilized primary bone marrow-derived progenitors, suggesting that VCAN proteolysis may promote differentiation of tumor-seeding DC precursors toward IRF8- and BATF3-expressing cDCs. Intratumoral BATF3-dependent DCs are critical determinants for T cell antitumor immunity, effector T cell trafficking to the tumor site, and response to immunotherapies. Our findings provide a rationale for testing VCAN proteolysis as a predictive and/or prognostic immune biomarker and VCAN-derived matrikines as novel immunotherapy agents. Copyright © 2017 by The American Association of Immunologists, Inc.

Cord blood derived CD4+ CD25(high) T cells become functional regulatory T cells upon antigen encounter.

PubMed

Mayer, Elisabeth; Bannert, Christina; Gruber, Saskia; Klunker, Sven; Spittler, Andreas; Akdis, Cezmi A; Szépfalusi, Zsolt; Eiwegger, Thomas

2012-01-01

Upon antigen exposure, cord blood derived T cells respond to ubiquitous environmental antigens by high proliferation. To date it remains unclear whether these "excessive" responses relate to different regulatory properties of the putative T regulatory cell (Treg) compartment or even expansion of the Treg compartment itself. Cord blood (>37 week of gestation) and peripheral blood (healthy controls) were obtained and different Treg cell subsets were isolated. The suppressive potential of Treg populations after antigen exposure was evaluated via functional inhibition assays ([(3)H]thymidine incorporation assay and CFSE staining) with or without allergen stimulation. The frequency and markers of CD4(+)CD25(high)FoxP3(+) T cells were characterized by mRNA analysis and flow cytometry. Cord blood derived CD4(+)CD25(high) cells did not show substantial suppressor capacity upon TCR activation, in contrast to CD4(+)CD25(high) cells freshly purified from adult blood. This could not be explained by a lower frequency of FoxP3(+)CD4(+)CD25(high)cells or FOXP3 mRNA expression. However, after antigen-specific stimulation in vitro, these cells showed strong proliferation and expansion and gained potent suppressive properties. The efficiency of their suppressive capacity can be enhanced in the presence of endotoxins. If T-cells were sorted according to their CD127 expression, a tiny subset of Treg cells (CD4(+)CD25(+)CD127(low)) is highly suppressive even without prior antigen exposure. Cord blood harbors a very small subset of CD4(+)CD25(high) Treg cells that requires antigen-stimulation to show expansion and become functional suppressive Tregs.

Shape And Size Of (90) Antiope Derived From An Exceptional Stellar Occultation On July 19 2011

NASA Astrophysics Data System (ADS)

Colas, F.; Berthier, J.; Vachier, F.; Marchis, F.; Jenniskens, P. M.; Enriquez, J. E.; Burns, K.; Descamps, P.; George, A.; Degenhardt, S.; Dunham, D.; Maley, P.; Merline, W. J.; Owen, W. M.; Timerson, B.; Preston, S.; Venable, R.; Allain, M.; Cawthon, R.; Cooper, J. R.; Fixelle, J.; Hicks, S.; Meldman-Floch, W. L.; Minteer, J.; Phillips, M.

2011-12-01

On July 19 2011 UT, the (90) Antiope double system occulted a 6.7-mag star (LQ Aquarii) with a path predicted to pass over much of northern California. The shape and separation of the components were predicted based on Descamps et al. (2009) model, plus additional Keck AO observations (Merline, Neyman, Tamblyn, Owen) collected on July 13 and 15, 2011 UT. Through a large collaboration in cooperation with the IOTA we organized a campaign of bservations involving 42 observers and 92 stations spread along the path of the occultation in northern California, Nevada, and Idaho to sample both components. The stellar occultation was successfully recorded by 41 stations with a maximum duration of ~33 s. A preliminary analysis of the data that are being processed and analyzed shows that an improved shape model of both components could be derived based on this campaign. We will present the final analysis of this campaign, which allow us to derive a more accurate period and separation for the binary system and also an improved density. We will discuss the origin of (90) Antiope based on the detection of a large concavity, possibly interpreted as a large impact crater on one of the components, already suggested by Descamps et al (2009). This research is partially supported by the NSF grant AAG-0807468, NASA grant NNX11AD62G and CNRS. We thank the many other members of IOTA who took part in this campaign.

Reconstruction of the pelvic brim and its role in the reduction accuracy of displaced T-shaped acetabular fracture.

PubMed

Harnroongroj, T; Asavamongkolkul, A; Chareancholvanich, K

2000-05-01

Open reduction of the displaced T-shaped acetabular fracture has a problem of accuracy of the fracture reduction. This study was carried out to demonstrate that the reconstruction of the pelvic brim by approaching the pubo-acetabular fragment plays a role in the accuracy of the reduction of displaced T-shaped acetabular fractures. From 1975 to 1990, a retrospective study was carried out of 22 patients who sustained a displaced T-shaped acetabular fracture. The patients were operated on by open reduction and internal fixation of the ischio-acetabular fragment to the posterior column without restoration of the pelvic brim. Radiographs of the pelvis were reviewed. The result showed that there was displacement of the pubo-acetabular fragment including the medial wall in all cases. As the result of this study, a prospective study between 1990 and 1997 was carried out of 15 patients who sustained displaced T-shaped acetabular fractures including 3 cases with medial displacement of the femoral head. The pubo-acetabular fragment was anatomically reduced and fixed to the anterior column of the acetabulumn as the first approach to restore a disrupted pelvic brim. There, patterns of the acetabular fracture were subsequently re-evaluated especially the ischio-acetabular fragment including the position of the femoral head by using an intraoperative portable X-ray technique. The stability of the hip joint was assessed by hip flexion. The intraoperative radiograph appearances of the ischio-acetabular fragment were visually confirmed by a second surgical exposure. The results showed that the intraoperative radiographs gave spontaneous reduction of the ischio-acetabular fragment in all patients except one. There was a reduction of the displaced femoral head into the hip socket in the three patients. The hip joints were stable in all patients. The second surgical exposure showed that there was good spontaneous reduction of the ischio-acetabular fragment to the posterior column by

Shape Universality Classes in the Random Sequential Adsorption of Nonspherical Particles

NASA Astrophysics Data System (ADS)

Baule, Adrian

2017-07-01

Random sequential adsorption (RSA) of particles of a particular shape is used in a large variety of contexts to model particle aggregation and jamming. A key feature of these models is the observed algebraic time dependence of the asymptotic jamming coverage ˜t-ν as t →∞ . However, the exact value of the exponent ν is not known apart from the simplest case of the RSA of monodisperse spheres adsorbed on a line (Renyi's seminal "car parking problem"), where ν =1 can be derived analytically. Empirical simulation studies have conjectured on a case-by-case basis that for general nonspherical particles, ν =1 /(d +d ˜ ), where d denotes the dimension of the domain, and d ˜ the number of orientational degrees of freedom of a particle. Here, we solve this long-standing problem analytically for the d =1 case—the "Paris car parking problem." We prove, in particular, that the scaling exponent depends on the particle shape, contrary to the original conjecture and, remarkably, falls into two universality classes: (i) ν =1 /(1 +d ˜ /2 ) for shapes with a smooth contact distance, e.g., ellipsoids, and (ii) ν =1 /(1 +d ˜ ) for shapes with a singular contact distance, e.g., spherocylinders and polyhedra. The exact solution explains, in particular, why many empirically observed scalings fall in between these two limits.

Tumor evasion of the immune system by converting CD4+CD25- T cells into CD4+CD25+ T regulatory cells: role of tumor-derived TGF-beta.

PubMed

Liu, Victoria C; Wong, Larry Y; Jang, Thomas; Shah, Ali H; Park, Irwin; Yang, Ximing; Zhang, Qiang; Lonning, Scott; Teicher, Beverly A; Lee, Chung

2007-03-01

CD4+CD25+ T regulatory (T(reg)) cells were initially described for their ability to suppress autoimmune diseases in animal models. An emerging interest is the potential role of T(reg) cells in cancer development and progression because they have been shown to suppress antitumor immunity. In this study, CD4+CD25- T cells cultured in conditioned medium (CM) derived from tumor cells, RENCA or TRAMP-C2, possess similar characteristics as those of naturally occurring T(reg) cells, including expression of Foxp3, a crucial transcription factor of T(reg) cells, production of low levels of IL-2, high levels of IL-10 and TGF-beta, and the ability to suppress CD4+CD25- T cell proliferation. Further investigation revealed a critical role of tumor-derived TGF-beta in converting CD4+CD25- T cells into T(reg) cells because a neutralizing Ab against TGF-beta, 1D11, completely abrogated the induction of T(reg) cells. CM from a nontumorigenic cell line, NRP-152, or irradiated tumor cells did not convert CD4+CD25- T cells to T(reg) cells because they produce low levels of TGF-beta in CM. Finally, we observed a reduced tumor burden in animals receiving 1D11. The reduction in tumor burden correlated with a decrease in tumor-derived TGF-beta. Treatment of 1D11 also reduced the conversion of CD4+ T cells into T(reg) cells and subsequent T(reg) cell-mediated suppression of antitumor immunity. In summary, we have demonstrated that tumor cells directly convert CD4+CD25- T cells to T(reg) cells through production of high levels of TGF-beta, suggesting a possible mechanism through which tumor cells evade the immune system.

Development of an LC-MS/MS Determination Method for T-2 Toxin and Its Glucoside and Acetyl Derivatives for Estimating the Contamination of Total T-2 Toxins in Staple Flours.

PubMed

Nakagawa, Hiroyuki; Matsuo, Yosuke; McCormick, Susan; Lim, Chee Wei

2018-05-01

A determination method previously validated for trichothecenes and zearalenone by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was adapted for the quantification of T-2 toxin (T-2) as well as its glucoside and acetyl derivatives, T-2-3-glucoside (T-2-3G) and 3-acetyl-T-2 (3A-T-2). HT-2 toxin (HT-2) and its acetyl derivative 3-acetyl-HT-2 (3A-HT-2) were also included as the target chemicals. Staple flours (56 samples collected from the Singapore market) were examined for contamination from T-2 and/or HT-2 and their derivatives. Among them, 16 flours were found to be contaminated with T-2 and/or HT-2, whereas none was contaminated with T-2-3G and 3A-HT-2, except for trace 3A-T-2 detected in 2 rye samples. Rye flour samples were frequently contaminated with both T-2 and HT-2. Some of the reference materials (RMs) were further analyzed, and T-2-3G and 3A-T-2 were quantitatively detected in corn and wheat RMs. The ratio of T-2-3G to T-2 in the RMs seemed to be much lower than the ratio of deoxynivalenol-3-glucoside to deoxynivalenol usually reported in former studies. To the best of our knowledge, the natural contamination of 3A-T-2 in staple flour is reported here for the first time.

Structural-conformational aspects of tRNA complexation with chloroethyl nitrosourea derivatives: A molecular modeling and spectroscopic investigation.

PubMed

Agarwal, Shweta; Tyagi, Gunjan; Chadha, Deepti; Mehrotra, Ranjana

2017-01-01

Chloroethyl nitrosourea derivatives (CENUs) represent an important family of anticancer chemotherapeutic agents, which are used in the treatment of different types of cancer such as brain tumors, resistant or relapsed Hodgkin's disease, small cell lung cancer and malignant melanoma. This work focuses towards understanding the interaction of chloroethyl nitrosourea derivatives; lomustine, nimustine and semustine with tRNA using spectroscopic approach in order to elucidate their auxiliary anticancer action mechanism inside the cell. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), Fourier transform infrared difference spectroscopy, circular dichroism spectroscopy and UV-visible spectroscopy were employed to investigate the binding parameters of tRNA-CENUs complexation. Results of present study demonstrate that all CENUs, studied here, interact with tRNA through guanine nitrogenous base residues and possibly further crosslink cytosine residues in paired region of tRNA. Moreover, spectral data collected for nimustine-tRNA and semustine-tRNA complex formation indicates towards the groove-directed-alkylation as their anti-malignant action, which involves the participation of uracil moiety located in major groove of tRNA. Besides this, tRNA-CENUs adduct formation did not alter the native conformation of biopolymer and tRNA remains in A-form after its interaction with all three nitrosourea derivatives studied. The binding constants (K a ) estimated for tRNA complexation with lomustine, nimustine and semustine are 2.55×10 2 M -1 , 4.923×10 2 M -1 and 4.223×10 2 M -1 respectively, which specify weak type of CENU's binding with tRNA. Moreover, molecular modeling simulations were also performed to predict preferential binding orientation of CENUs with tRNA that corroborates well with spectral outcomes. The findings, presented here, recognize tRNA binding properties of CENUs that can further help in rational designing of more specific and

Immune Privilege and Eye-Derived T-Regulatory Cells.

PubMed

Keino, Hiroshi; Horie, Shintaro; Sugita, Sunao

2018-01-01

Certain cellular components of the eye, such as neural retina, are unable to regenerate and replicate after destructive inflammation. Ocular immune privilege provides the eye with immune protection against intraocular inflammation in order to minimize the risk to vision integrity. The eye and immune system use strategies to maintain the ocular immune privilege by regulating the innate and adaptive immune response, which includes immunological ignorance, peripheral tolerance to eye-derived antigens, and intraocular immunosuppressive microenvironment. In this review, we summarize current knowledge regarding the molecular mechanism responsible for the development and maintenance of ocular immune privilege via regulatory T cells (Tregs), which are generated by the anterior chamber-associated immune deviation (ACAID), and ocular resident cells including corneal endothelial (CE) cells, ocular pigment epithelial (PE) cells, and aqueous humor. Furthermore, we examined the therapeutic potential of Tregs generated by RPE cells that express transforming growth factor beta (TGF- β ), cytotoxic T lymphocyte-associated antigen-2 alpha (CTLA-2 α ), and retinoic acid for autoimmune uveoretinitis and evaluated a new strategy using human RPE-induced Tregs for clinical application in inflammatory ocular disease. We believe that a better understanding of the ocular immune privilege associated with Tregs might offer a new approach with regard to therapeutic interventions for ocular autoimmunity.

Toxoplasma gondii Antigen-Pulsed-Dendritic Cell-Derived Exosomes Induce a Protective Immune Response against T. gondii Infection

PubMed Central

Aline, Fleur; Bout, Daniel; Amigorena, Sébastian; Roingeard, Philippe; Dimier-Poisson, Isabelle

2004-01-01

It was previously demonstrated that immunizing mice with spleen dendritic cells (DCs) that had been pulsed ex vivo with Toxoplasma gondii antigens triggers a systemic Th1-biased specific immune response and induces protection against infection. T. gondii can cause severe sequelae in the fetuses of mothers who acquire the infection during pregnancy, as well as life-threatening neuropathy in immunocompromised patients, in particular those with AIDS. Here, we investigate the efficacy of a novel cell-free vaccine composed of DC exosomes, which are secreted antigen-presenting vesicles that express functional major histocompatibility complex class I and II and T-cell-costimulatory molecules. They have already been shown to induce potent antitumor immune responses. We investigated the potential of DC2.4 cell line-derived exosomes to induce protective immunity against toxoplasmosis. Our data show that most adoptively transferred T. gondii-pulsed DC-derived exosomes were transferred to the spleen, elicited a strong systemic Th1-modulated Toxoplasma-specific immune response in vivo, and conferred good protection against infection. These findings support the possibility that DC-derived exosomes can be used for T. gondii immunoprophylaxis and for immunoprophylaxis against many other pathogens. PMID:15213158

On the use of star-shaped genealogies in inference of coalescence times.

PubMed Central

Rosenberg, Noah A; Hirsh, Aaron E

2003-01-01

Genealogies from rapidly growing populations have approximate "star" shapes. We study the degree to which this approximation holds in the context of estimating the time to the most recent common ancestor (T(MRCA)) of a set of lineages. In an exponential growth scenario, we find that unless the product of population size (N) and growth rate (r) is at least approximately 10(5), the "pairwise comparison estimator" of T(MRCA) that derives from the star genealogy assumption has bias of 10-50%. Thus, the estimator is appropriate only for large populations that have grown very rapidly. The "tree-length estimator" of T(MRCA) is more biased than the pairwise comparison estimator, having low bias only for extremely large values of Nr. PMID:12930771

tRNA-derived short RNAs bind to Saccharomyces cerevisiae ribosomes in a stress-dependent manner and inhibit protein synthesis in vitro

PubMed Central

Kasprzyk, Marta; Twardowski, Tomasz

2016-01-01

Recently, a number of ribosome-associated non-coding RNAs (rancRNAs) have been discovered in all three domains of life. In our previous studies, we have described several types of rancRNAs in Saccharomyces cerevisiae, derived from many cellular RNAs, including mRNAs, rRNAs, tRNAs and snoRNAs. Here, we present the evidence that the tRNA fragments from simple eukaryotic organism S. cerevisiae directly bind to the ribosomes. Interestingly, rancRNA-tRFs in yeast are derived from both, 5′- and 3′-part of the tRNAs and both types of tRFs associate with the ribosomes in vitro. The location of tRFs within the ribosomes is distinct from classical A- and P-tRNA binding sites. Moreover, 3′-tRFs bind to the distinct site than 5′-tRFs. These interactions are stress dependent and as a consequence, provoke regulation of protein biosynthesis. We observe strong correlation between tRF binding to the ribosomes and inhibition of protein biosynthesis in particular environmental conditions. These results implicate the existence of an ancient and conserved mechanism of translation regulation with the involvement of ribosome-associating tRNA-derived fragments. PMID:27609601

Activated T cells sustain myeloid-derived suppressor cell-mediated immune suppression

PubMed Central

Damuzzo, Vera; Francescato, Samuela; Pozzuoli, Assunta; Berizzi, Antonio; Mocellin, Simone; Rossi, Carlo Riccardo; Bronte, Vincenzo; Mandruzzato, Susanna

2016-01-01

The expansion of myeloid derived suppressor cells (MDSCs), a suppressive population able to hamper the immune response against cancer, correlates with tumor progression and overall survival in several cancer types. We have previously shown that MDSCs can be induced in vitro from precursors present in the bone marrow and observed that these cells are able to actively proliferate in the presence of activated T cells, whose activation level is critical to drive the suppressive activity of MDSCs. Here we investigated at molecular level the mechanisms involved in the interplay between MDSCs and activated T cells. We found that activated T cells secrete IL-10 following interaction with MDSCs which, in turn, activates STAT3 phosphorylation on MDSCs then leading to B7-H1 expression. We also demonstrated that B7-H1+ MDSCs are responsible for immune suppression through a mechanism involving ARG-1 and IDO expression. Finally, we show that the expression of ligands B7-H1 and MHC class II both on in vitro-induced MDSCs and on MDSCs in the tumor microenvironment of cancer patients is paralleled by an increased expression of their respective receptors PD-1 and LAG-3 on T cells, two inhibitory molecules associated with T cell dysfunction. These findings highlight key molecules and interactions responsible for the extensive cross-talk between MDSCs and activated T cells that are at the basis of immune suppression. PMID:26700461

Secondary allergic T cell responses are regulated by dendritic cell-derived thrombospondin-1 in the setting of allergic eye disease

PubMed Central

Smith, R. E.; Reyes, N. J.; Khandelwal, P.; Schlereth, S. L.; Lee, H. S.; Masli, S.; Saban, D. R.

2016-01-01

Allergic eye disease, as in most forms of atopy, ranges in severity among individuals from immediate hypersensitivity to a severe and debilitating chronic disease. Dendritic cells play a key role in stimulating pathogenic T cells in allergen re-exposure, or secondary responses. However, molecular cues by dendritic cells underpinning allergic T cell response levels and the impact that this control has on consequent severity of allergic disease are poorly understood. Here, we show that a deficiency in thrombospondin-1, a matricellular protein known to affect immune function, has subsequent effects on downstream T cell responses during allergy, as revealed in an established mouse model of allergic eye disease. More specifically, we demonstrate that a thrombospondin-1 deficiency specific to dendritic cells leads to heightened secondary T cell responses and consequent clinical disease. Interestingly, whereas thrombospondin-1-deficient dendritic cells augmented activity of allergen-primed T cells, this increase was not recapitulated with naïve T cells in vitro. The role of dendritic cell-derived thrombospondin-1 in regulating secondary allergic T cell responses was confirmed in vivo, as local transfer of thrombospondin-1-sufficient dendritic cells to the ocular mucosa of thrombospondin-1 null hosts prevented the development of augmented secondary T cell responses and heightened allergic eye disease clinical responses. Finally, we demonstrate that topical instillation of thrombospondin-1-derived peptide reduces T cell activity and clinical progression of allergic eye disease. Taken together, this study reveals an important modulatory role of dendritic cell-derived thrombospondin-1 on secondary allergic T cell responses and suggests the possible dysregulation of dendritic cell-derived thrombospondin-1 expression as a factor in allergic eye disease severity. PMID:26856994

Constraining Cometary Crystal Shapes from IR Spectral Features

NASA Astrophysics Data System (ADS)

Wooden, D. H.; Lindsay, S.; Harker, D. E.; Kelley, M. S.; Woodward, C. E.; Murphy, J. R.

2013-12-01

forsterite crystal shapes (equant, b-platelets, c-platelets, b-colums - excluding a- and c-columns) derived from our modeling [17] of comet Hale-Bopp, compared to laboratory synthesis experiments [18], suggests that these crystals are high temperature condensates. By observing and modeling the crystalline features in comet ISON, we may constrain forsterite crystal shape(s) and link to their formation temperature(s) and environment(s). References: [1] Campins, H., Ryan, E.V. 1989. ApJ, 341, 1059 [2] Crovisier, J., et al. 1997. Science, 275, 1904 [3] Wooden, D.H., et al. 1999. ApJ, 517, 1034 [4] Wooden, D.H., et al. 2004. ApJL, 612, L77 [5] Harker, D.E., et al. 2002. ApJ, 580, 579 [6] --. 2004, ApJ, 615, 1081 [7] Lisse, C.M., et al. 2006. Icarus 195, 941-944. [8] Lisse, C.M., et.al. 2007. Icarus 191, 223-240. [9] Kelley, M.S., et al. 2010, LPSC, 41, #2375 [10] Harker, D.E., et al. 2011, AJ, 141, 26 [11] Draine, B.T., & Flatau, P.J. 1994, J. Opt. Soc. Am. A, 11, 1491 [12] Draine, B.T., & Flatau, P.J. 2008, J. Opt. Soc. Am. A, 25, 2693 [13] Fabian, D., et al., 2001, A&A, 378, 228 [14] Tamanai, A., et al. 2006. ApJ, 648, L147 [15] Tamanai, A., et al. 2009. ASP Conf. Ser., 414, 438 [16] Koike, C., et al. 2010. ApJ, 709, 983 [17] Lindsay, S.S., et al. 2013, ApJ, 766, 54 [18] Tsuchiyama, A. 1998. Mineralogical J., 20, 59 [19] Kobatake, H., et al., 2008. Icarus, 198, 208 [20] Takigawa, A., et al.. 2009. ApJL, 707, L97

Identification of Novel Avian Influenza Virus Derived CD8+ T-Cell Epitopes

PubMed Central

Reemers, Sylvia S. N.; van Haarlem, Daphne A.; Sijts, Alice J. A. M.; Vervelde, Lonneke; Jansen, Christine A.

2012-01-01

Avian influenza virus (AIV) infection is a continuing threat to both humans and poultry. Influenza virus specific CD8+ T cells are associated with protection against homologous and heterologous influenza strains. In contrast to what has been described for humans and mice, knowledge on epitope-specific CD8+ T cells in chickens is limited. Therefore, we set out to identify AIV-specific CD8+ T-cell epitopes. Epitope predictions based on anchor residues resulted in 33 candidate epitopes. MHC I inbred chickens were infected with a low pathogenic AIV strain and sacrificed at 5, 7, 10 and 14 days post infection (dpi). Lymphocytes isolated from lung, spleen and blood were stimulated ex vivo with AIV-specific pooled or individual peptides and the production of IFNγ was determined by ELIspot. This resulted in the identification of 12 MHC B12-restricted, 3 B4-restricted and 1 B19-restricted AIV- specific CD8+ T-cell epitopes. In conclusion, we have identified novel AIV-derived CD8+ T-cell epitopes for several inbred chicken strains. This knowledge can be used to study the role of CD8+ T cells against AIV infection in a natural host for influenza, and may be important for vaccine development. PMID:22384112

In situ oil shale retort with a generally T-shaped vertical cross section

DOEpatents

Ricketts, Thomas E.

1981-01-01

An in situ oil shale retort is formed in a subterranean formation containing oil shale. The retort contains a fragmented permeable mass of formation particles containing oil shale and has a production level drift in communication with a lower portion of the fragmented mass for withdrawing liquid and gaseous products of retorting during retorting of oil shale in the fragmented mass. The principal portion of the fragmented mass is spaced vertically above a lower production level portion having a generally T-shaped vertical cross section. The lower portion of the fragmented mass has a horizontal cross sectional area smaller than the horizontal cross sectional area of the upper principal portion of the fragmented mass above the production level.

Feasibility and safety of modified inverted T-shaped method using linear stapler with movable cartridge fork for esophagojejunostomy following laparoscopic total gastrectomy.

PubMed

Ohuchida, Kenoki; Nagai, Eishi; Moriyama, Taiki; Shindo, Koji; Manabe, Tatsuya; Ohtsuka, Takao; Shimizu, Shuji; Nakamura, Masafumi

2017-01-01

We previously reported the use of an inverted T-shaped method to obtain a suitable view for hand sewing to close the common entry hole when the linear stapler was fired for esophagojejunostomy after laparoscopic total gastrectomy (LTG). This conventional method involved insertion of the fixed cartridge fork to the Roux limb and the fine movable anvil fork to the esophagus to avoid perforation of the jejunum. However, insertion of the movable anvil fork to the esophagus during this procedure often requires us to strongly push down the main body of the stapler with the fixed cartridge fork to bring the direction of the anvil fork in line with the direction of the long axis of the esophagus while controlling the opening of the movable anvil fork. We therefore modified this complicated inverted T-shaped method using a linear stapler with a movable cartridge fork. This modified method involved insertion of the movable cartridge fork into the Roux limb followed by natural, easy insertion of the fixed anvil fork into the esophagus without controlling the opening of the movable cartridge fork. We performed LTG in a total of 155 consecutive patients with gastric cancer from November 2007 to December 2015 in Kyushu University Hospital. After LTG, we performed the conventional inverted T-shaped method using a linear stapler with a fixed cartridge fork in 61 patients from November 2007 to July 2011 (fixed cartridge group). From August 2011, we used a linear stapler with a movable cartridge fork and performed the modified inverted T-shaped method in 94 patients (movable cartridge group). We herein compare the short-term outcomes in 94 cases of LTG using the modified method (movable cartridge fork) with those in 61 cases using the conventional method (fixed cartridge fork). We found no significant differences in the perioperative or postoperative events between the movable and fixed cartridge groups. One case of anastomotic leakage occurred in the fixed cartridge group, but no

Feasibility and safety of modified inverted T-shaped method using linear stapler with movable cartridge fork for esophagojejunostomy following laparoscopic total gastrectomy

PubMed Central

Ohuchida, Kenoki; Moriyama, Taiki; Shindo, Koji; Manabe, Tatsuya; Ohtsuka, Takao; Shimizu, Shuji; Nakamura, Masafumi

2017-01-01

Background We previously reported the use of an inverted T-shaped method to obtain a suitable view for hand sewing to close the common entry hole when the linear stapler was fired for esophagojejunostomy after laparoscopic total gastrectomy (LTG). This conventional method involved insertion of the fixed cartridge fork to the Roux limb and the fine movable anvil fork to the esophagus to avoid perforation of the jejunum. However, insertion of the movable anvil fork to the esophagus during this procedure often requires us to strongly push down the main body of the stapler with the fixed cartridge fork to bring the direction of the anvil fork in line with the direction of the long axis of the esophagus while controlling the opening of the movable anvil fork. We therefore modified this complicated inverted T-shaped method using a linear stapler with a movable cartridge fork. This modified method involved insertion of the movable cartridge fork into the Roux limb followed by natural, easy insertion of the fixed anvil fork into the esophagus without controlling the opening of the movable cartridge fork. Methods We performed LTG in a total of 155 consecutive patients with gastric cancer from November 2007 to December 2015 in Kyushu University Hospital. After LTG, we performed the conventional inverted T-shaped method using a linear stapler with a fixed cartridge fork in 61 patients from November 2007 to July 2011 (fixed cartridge group). From August 2011, we used a linear stapler with a movable cartridge fork and performed the modified inverted T-shaped method in 94 patients (movable cartridge group). We herein compare the short-term outcomes in 94 cases of LTG using the modified method (movable cartridge fork) with those in 61 cases using the conventional method (fixed cartridge fork). Results We found no significant differences in the perioperative or postoperative events between the movable and fixed cartridge groups. One case of anastomotic leakage occurred in the

T cell–derived interleukin (IL)-21 promotes brain injury following stroke in mice

PubMed Central

Clarkson, Benjamin D.S.; Ling, Changying; Shi, Yejie; Harris, Melissa G.; Rayasam, Aditya; Sun, Dandan; Salamat, M. Shahriar; Kuchroo, Vijay; Lambris, John D.; Sandor, Matyas

2014-01-01

T lymphocytes are key contributors to the acute phase of cerebral ischemia reperfusion injury, but the relevant T cell–derived mediators of tissue injury remain unknown. Using a mouse model of transient focal brain ischemia, we report that IL-21 is highly up-regulated in the injured mouse brain after cerebral ischemia. IL-21–deficient mice have smaller infarcts, improved neurological function, and reduced lymphocyte accumulation in the brain within 24 h of reperfusion. Intracellular cytokine staining and adoptive transfer experiments revealed that brain-infiltrating CD4+ T cells are the predominant IL-21 source. Mice treated with decoy IL-21 receptor Fc fusion protein are protected from reperfusion injury. In postmortem human brain tissue, IL-21 localized to perivascular CD4+ T cells in the area surrounding acute stroke lesions, suggesting that IL-21–mediated brain injury may be relevant to human stroke. PMID:24616379

An approach to the unification of suppressor T cell circuits: a simplified assay for the induction of suppression by T cell-derived, antigen-binding molecules (T-ABM).

PubMed

Chue, B; Ferguson, T A; Beaman, K D; Rosenman, S J; Cone, R E; Flood, P M; Green, D R

1989-01-01

A system is presented in which the in vitro response to sheep red blood cells (SRBC) can be regulated using antigenic determinants coupled to SRBC and T cell-derived antigen-binding molecules (T-ABM) directed against the coupled determinants. T suppressor-inducer factors (TsiF's) are composed of two molecules, one of which is a T-ABM and one which bears I-J determinants (I-J+ molecule). Using two purified T-ABM which have not previously been shown to have in vitro activity, we produced antigen-specific TsiF's which were capable of inducing the suppression of the anti-SRBC response. Suppression was found to require both the T-ABM and the I-J+ molecule, SRBC conjugated with the antigen for which the T-ABM was specific, and a population of Ly-2+ T cells in the culture. Two monoclonal TsiF (or TsF1) were demonstrated to induce suppression of the anti-SRBC response in this system, provided the relevant antigen was coupled to the SRBC in culture. The results are discussed in terms of the general functions of T-ABM in the immune system. This model will be useful in direct, experimental comparisons of the function of T-ABM and suppressor T cell factors under study in different systems and laboratories.

Sawtooth oscillations in shaped plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazarus, E. A.; Luce, T. C.; Burrell, K. H.

The role of interchange and internal kink modes in the sawtooth oscillations is explored by comparing bean- and oval-shaped plasmas. The n=1 instability that results in the collapse of the sawtooth has been identified as a quasi-interchange in the oval cases and the internal kink in the bean shape. The ion and electron temperature profiles are followed in detail through the sawtooth ramp. It is found that electron energy transport rates are very high in the oval and quite low in the bean shape. Ion energy confinement in the oval is excellent and the sawtooth amplitude ({delta}T/T) in the ionmore » temperature is much larger than that of the electrons. The sawtooth amplitudes for ions and electrons are comparable in the bean shape. The measured q profiles in the bean and oval shapes are found to be consistent with neoclassical current diffusion of the toroidal current, and the observed differences in q largely result from the severe differences in electron energy transport. For both shapes the collapse flattens the q profile and after the collapse return to q{sub 0} > or approx. 1. Recent results on intermediate shapes are reported. These shapes show that the electron energy transport improves gradually as the plasma triangularity is increased.« less

Secondary allergic T cell responses are regulated by dendritic cell-derived thrombospondin-1 in the setting of allergic eye disease.

PubMed

Smith, R E; Reyes, N J; Khandelwal, P; Schlereth, S L; Lee, H S; Masli, S; Saban, D R

2016-08-01

Allergic eye disease, as in most forms of atopy, ranges in severity among individuals from immediate hypersensitivity to a severe and debilitating chronic disease. Dendritic cells play a key role in stimulating pathogenic T cells in allergen re-exposure, or secondary responses. However, molecular cues by dendritic cells underpinning allergic T cell response levels and the impact that this control has on consequent severity of allergic disease are poorly understood. Here, we show that a deficiency in thrombospondin-1, a matricellular protein known to affect immune function, has subsequent effects on downstream T cell responses during allergy, as revealed in an established mouse model of allergic eye disease. More specifically, we demonstrate that a thrombospondin-1 deficiency specific to dendritic cells leads to heightened secondary T cell responses and consequent clinical disease. Interestingly, whereas thrombospondin-1-deficient dendritic cells augmented activity of allergen-primed T cells, this increase was not recapitulated with naïve T cells in vitro. The role of dendritic cell-derived thrombospondin-1 in regulating secondary allergic T cell responses was confirmed in vivo, as local transfer of thrombospondin-1-sufficient dendritic cells to the ocular mucosa of thrombospondin-1 null hosts prevented the development of augmented secondary T cell responses and heightened allergic eye disease clinical responses. Finally, we demonstrate that topical instillation of thrombospondin-1-derived peptide reduces T cell activity and clinical progression of allergic eye disease. Taken together, this study reveals an important modulatory role of dendritic cell-derived thrombospondin-1 on secondary allergic T cell responses and suggests the possible dysregulation of dendritic cell-derived thrombospondin-1 expression as a factor in allergic eye disease severity. © Society for Leukocyte Biology.

Experimental study on melting and flowing behavior of thermoplastics combustion based on a new setup with a T-shape trough.

PubMed

Xie, Qiyuan; Zhang, Heping; Ye, Ruibo

2009-07-30

The objective of this work is to quantitatively study the burning characteristics of thermoplastics. A new experimental setup with a T-shape trough is designed. Based on this setup, the loop mechanism between the wall fire and pool fires induced by the melting and dripping of thermoplastic can be well simulated and studied. Additionally, the flowing characteristics of pool fires can also be quantitatively analyzed. Experiments are conducted for PP and PE sheets with different thicknesses. The maximum distances of the induced flowing pool flame in the T-shape trough are recorded and analyzed. The typical fire parameters, such as heat release rates (HRRs), CO concentrations are also monitored. The results show that the softening and clinging of the thermoplastic sheets plays a considerable role for their vertical wall burning. It is illustrated that the clinging of burning thermoplastic sheet may be mainly related with the softening temperatures and the ignition temperatures of the thermoplastics, as well as their viscosity coefficients. Through comparing the maximum distances of flowing flame of induced pool fires in the T-shape trough for thermoplastic sheets with different thicknesses, it is indicated that the pool fires induced by PE materials are easier to flow away than that of PP materials. Therefore, PE materials may be more dangerous for their faster pool fire spread on the floor. These experimental results preliminarily illustrate that this new experimental setup is helpful for quantitatively studying the special burning feature of thermoplastics although further modifications is needed for this setup in the future.

Liquid Chromatographic Analysis of α-Dicarbonyls Using Girard-T Reagent Derivatives.

PubMed

Lawrence, Glen D; Rahmat, Rozaiha; Makahleh, Ahmad; Saad, Bahruddin

2017-11-01

The measurement of α-dicarbonyls and other degradation products of sugars has become important in view of their toxicity. Although there are several methods used for their analysis, most require long reaction times to form UV absorbing or fluorescent derivatives and the nonpolar nature of commonly used derivatives necessitates relatively high concentrations of organic solvents for elution in reverse phase liquid chromatography. The present method describes the use of Girard-T reagent in a simple, one step derivatization of α-dicarbonyls and conjugated aldehydes and analysis using ion-pair reverse phase liquid chromatography. The limit of detection was in the range of 0.06-0.09 μM (4-12 ng/mL) for glyoxal, methylglyoxal, 3-deoxyglucosone and 5-hydroxymethylfurfural with good linear response and reproducibility using UV detection. The hydrazone derivatives were stable for several days in solution. The method was used to study degradation of several sugars and quantification of the target α-dicarbonyls and 5-hydroxymethylfurfural in several soft drinks. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Shape design sensitivity analysis using domain information

NASA Technical Reports Server (NTRS)

Seong, Hwal-Gyeong; Choi, Kyung K.

1985-01-01

A numerical method for obtaining accurate shape design sensitivity information for built-up structures is developed and demonstrated through analysis of examples. The basic character of the finite element method, which gives more accurate domain information than boundary information, is utilized for shape design sensitivity improvement. A domain approach for shape design sensitivity analysis of built-up structures is derived using the material derivative idea of structural mechanics and the adjoint variable method of design sensitivity analysis. Velocity elements and B-spline curves are introduced to alleviate difficulties in generating domain velocity fields. The regularity requirements of the design velocity field are studied.

Interactions between butterfly-shaped pulses in the inhomogeneous media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Wen-Jun; Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190; Huang, Long-Gang

2014-10-15

Pulse interactions affect pulse qualities during the propagation. Interactions between butterfly-shaped pulses are investigated to improve pulse qualities in the inhomogeneous media. In order to describe the interactions between butterfly-shaped pulses, analytic two-soliton solutions are derived. Based on those solutions, influences of corresponding parameters on pulse interactions are discussed. Methods to control the pulse interactions are suggested. - Highlights: • Interactions between butterfly-shaped pulses are investigated. • Methods to control the pulse interactions are suggested. • Analytic two-soliton solutions for butterfly-shaped pulses are derived.

HBV-Derived Synthetic Long Peptide Can Boost CD4+ and CD8+ T-Cell Responses in Chronic HBV Patients Ex Vivo

PubMed Central

Dou, Yingying; van Montfoort, Nadine; van den Bosch, Aniek; de Man, Robert A; Zom, Gijs G; Krebber, Willem-Jan; Melief, Cornelis J M; Buschow, Sonja I; Woltman, Andrea M

2018-01-01

Abstract Background Vaccination with synthetic long peptides (SLP) is a promising new treatment strategy for chronic hepatitis B virus (CHB). SLP can induce broad T-cell responses for all HLA types. Here we investigated the ability of a prototype HBV-core (HBc)-sequence-derived SLP to boost HBV-specific T cells in CHB patients ex vivo. Methods HBc-SLP was used to assess cross-presentation by monocyte-derived dendritic cells (moDC) and BDCA1+ blood myeloid DC (mDC) to engineered HBV-specific CD8+ T cells. Autologous SLP-loaded and toll-like receptor (TLR)-stimulated DC were used to activate patient HBc-specific CD8+ and CD4+ T cells. Results HBV-SLP was cross-presented by moDC, which was further enhanced by adjuvants. Patient-derived SLP-loaded moDC significantly increased autologous HBcAg18-27-specific CD8+ T cells and CD4+ T cells ex vivo. HBV-specific T cells were functional as they synthesized tumor necrosis factor-alpha and interferon-gamma. In 6/7 of patients blockade of PD-L1 further increased SLP effects. Also, importantly, patient-derived BDCA1+ mDC cross-presented and activated autologous T-cell responses ex vivo. Conclusions As a proof of concept, we showed a prototype HBc-SLP can boost T-cell responses in patients ex vivo. These results pave the way for the development of a therapeutic SLP-based vaccine to induce effective HBV-specific adaptive immune responses in CHB patients. PMID:29220492

New oxirane derivatives of 1,4-naphthoquinones and their evaluation against T. cruzi epimastigote forms.

PubMed

Carneiro, Paula F; do Nascimento, Samara B; Pinto, Antonio V; Pinto, Maria do Carmo F R; Lechuga, Guilherme C; Santos, Dilvani O; dos Santos Júnior, Helvécio M; Resende, Jackson A L C; Bourguignon, Saulo C; Ferreira, Vitor F

2012-08-15

New oxirane derivatives were synthesized using six naphthoquinones as the starting materials. Our biological results showed that these oxiranes acted as trypanocidal agents against Trypanosoma cruzi with minimal cytotoxicity in the VERO cell line compared to naphthoquinones. In particular, oxirane derivative 14 showed low cytotoxicity in a mammalian cell line and exhibited better activity against epimastigote forms of T.cruzi than the current drug used to treat Chagas disease, benznidazole. Copyright © 2012 Elsevier Ltd. All rights reserved.

Jet shapes in dijet events at the LHC in SCET

NASA Astrophysics Data System (ADS)

Hornig, Andrew; Makris, Yiannis; Mehen, Thomas

2016-04-01

We consider the class of jet shapes known as angularities in dijet production at hadron colliders. These angularities are modified from the original definitions in e + e - collisions to be boost invariant along the beam axis. These shapes apply to the constituents of jets defined with respect to either k T -type (anti- k T , C/ A, and k T ) algorithms and cone-type algorithms. We present an SCET factorization formula and calculate the ingredients needed to achieve next-to-leading-log (NLL) accuracy in kinematic regions where non-global logarithms are not large. The factorization formula involves previously unstudied "unmeasured beam functions," which are present for finite rapidity cuts around the beams. We derive relations between the jet functions and the shape-dependent part of the soft function that appear in the factorized cross section and those previously calculated for e + e - collisions, and present the calculation of the non-trivial, color-connected part of the soft-function to O({α}_s) . This latter part of the soft function is universal in the sense that it applies to any experimental setup with an out-of-jet p T veto and rapidity cuts together with two identified jets and it is independent of the choice of jet (sub-)structure measurement. In addition, we implement the recently introduced soft-collinear refactorization to resum logarithms of the jet size, valid in the region of non-enhanced non-global logarithm effects. While our results are valid for all 2 → 2 channels, we compute explicitly for the qq' → qq' channel the color-flow matrices and plot the NLL resummed differential dijet cross section as an explicit example, which shows that the normalization and scale uncertainty is reduced when the soft function is refactorized. For this channel, we also plot the jet size R dependence, the p T cut dependence, and the dependence on the angularity parameter a.

Jet shapes in dijet events at the LHC in SCET

DOE PAGES

Hornig, Andrew; Makris, Yiannis; Mehen, Thomas

2016-04-15

Here, we consider the class of jet shapes known as angularities in dijet production at hadron colliders. These angularities are modified from the original definitions in e + e- collisions to be boost invariant along the beam axis. These shapes apply to the constituents of jets defined with respect to either k T-type (anti-k T, C/A, and k T) algorithms and cone-type algorithms. We present an SCET factorization formula and calculate the ingredients needed to achieve next-to-leading-log (NLL) accuracy in kinematic regions where non-global logarithms are not large. The factorization formula involves previously unstudied “unmeasured beam functions,” which are present for finite rapidity cuts around the beams. We derive relations between the jet functions and the shape-dependent part of the soft function that appear in the factorized cross section and those previously calculated for e +e - collisions, and present the calculation of the non-trivial, color-connected part of the soft-function to O(αs) . This latter part of the soft function is universal in the sense that it applies to any experimental setup with an out-of-jet p T veto and rapidity cuts together with two identified jets and it is independent of the choice of jet (sub-)structure measurement. In addition, we implement the recently introduced soft-collinear refactorization to resum logarithms of the jet size, valid in the region of non-enhanced non-global logarithm effects. While our results are valid for all 2 → 2 channels, we compute explicitly for the qq' → qq' channel the color-flow matrices and plot the NLL resummed differential dijet cross section as an explicit example, which shows that the normalization and scale uncertainty is reduced when the soft function is refactorized. For this channel, we also plot the jet size R dependence, the pmore » $$cut\\atop{T}$$ dependence, and the dependence on the angularity parameter a.« less

Theileria parva antigens recognized by CD8+ T cells show varying degrees of diversity in buffalo-derived infected cell lines.

PubMed

Sitt, Tatjana; Pelle, Roger; Chepkwony, Maurine; Morrison, W Ivan; Toye, Philip

2018-05-06

The extent of sequence diversity among the genes encoding 10 antigens (Tp1-10) known to be recognized by CD8+ T lymphocytes from cattle immune to Theileria parva was analysed. The sequences were derived from parasites in 23 buffalo-derived cell lines, three cattle-derived isolates and one cloned cell line obtained from a buffalo-derived stabilate. The results revealed substantial variation among the antigens through sequence diversity. The greatest nucleotide and amino acid diversity were observed in Tp1, Tp2 and Tp9. Tp5 and Tp7 showed the least amount of allelic diversity, and Tp5, Tp6 and Tp7 had the lowest levels of protein diversity. Tp6 was the most conserved protein; only a single non-synonymous substitution was found in all obtained sequences. The ratio of non-synonymous: synonymous substitutions varied from 0.84 (Tp1) to 0.04 (Tp6). Apart from Tp2 and Tp9, we observed no variation in the other defined CD8+ T cell epitopes (Tp4, 5, 7 and 8), indicating that epitope variation is not a universal feature of T. parva antigens. In addition to providing markers that can be used to examine the diversity in T. parva populations, the results highlight the potential for using conserved antigens to develop vaccines that provide broad protection against T. parva.

Reduction of shading-derived artifacts in skin chromophore imaging without measurements or assumptions about the shape of the subject

NASA Astrophysics Data System (ADS)

Yoshida, Kenichiro; Nishidate, Izumi; Ojima, Nobutoshi; Iwata, Kayoko

2014-01-01

To quantitatively evaluate skin chromophores over a wide region of curved skin surface, we propose an approach that suppresses the effect of the shading-derived error in the reflectance on the estimation of chromophore concentrations, without sacrificing the accuracy of that estimation. In our method, we use multiple regression analysis, assuming the absorbance spectrum as the response variable and the extinction coefficients of melanin, oxygenated hemoglobin, and deoxygenated hemoglobin as the predictor variables. The concentrations of melanin and total hemoglobin are determined from the multiple regression coefficients using compensation formulae (CF) based on the diffuse reflectance spectra derived from a Monte Carlo simulation. To suppress the shading-derived error, we investigated three different combinations of multiple regression coefficients for the CF. In vivo measurements with the forearm skin demonstrated that the proposed approach can reduce the estimation errors that are due to shading-derived errors in the reflectance. With the best combination of multiple regression coefficients, we estimated that the ratio of the error to the chromophore concentrations is about 10%. The proposed method does not require any measurements or assumptions about the shape of the subjects; this is an advantage over other studies related to the reduction of shading-derived errors.

Induction of IgA B cell differentiation of bone marrow-derived B cells by Peyer's patch autoreactive helper T cells.

PubMed

Kihira, T; Kawanishi, H

1995-08-01

The objective of this study was to demonstrate in vitro that bone marrow-derived pro/pre-B cells bearing mu mRNA can switch their Ig heavy-chain isotype to that of alpha mRNA-expressing B cells after contact with Peyer's patches-derived activated autoreactive CD4+ T cells. Bone marrow-derived pro/pre-B cells and activated autoreactive Peyer's patch, mesenteric lymph node, or spleen CD4+ T cells were co-cultured in the presence of recombinant (r) IL-2, rIL-7, and Con A for 3 days. The mixed cultured cells were isolated for preparation of total RNA. Dot/slot hybridization, using murine C mu (pu3741) and C alpha (P alpha J558) Ig heavy-chain cDNA probes, detected C mu and C alpha Ig heavy-chain mRNA transcripts. The magnitude of each mRNA expression was measured demsitometrically. In addition, the secreted class-specific Ig contents from the co-cultured supernatants were measured. The results indicate that activated autoreactive Peyer's patch and mesenteric lymph node CD4+ T cells provide a specific Ig heavy-chain switch from mu to alpha (Peyer's patch CD4+ T cells > mesenteric lymph node CD4+ T cells) in bone marrow-derived pro/pre-B cells and also assist to develop IgA-secreting plasma cells. The alpha heavy-chain switch and IgA production do not occur in the presence of activated autoreactive spleen CD4+ T cells. These results support the view that autoreactive gut Peyer's patch CD4+ T cells, at least, regulate IgA B cell heavy-chain switching and terminal differentiation during gut mucosal B cell development.

Host-Derived CD70 Suppresses Murine Graft-versus-Host Disease by Limiting Donor T Cell Expansion and Effector Function.

PubMed

Leigh, Nicholas D; O'Neill, Rachel E; Du, Wei; Chen, Chuan; Qiu, Jingxin; Ashwell, Jonathan D; McCarthy, Philip L; Chen, George L; Cao, Xuefang

2017-07-01

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment for hematologic and immunologic diseases. However, graft-versus-host disease (GVHD) may develop when donor-derived T cells recognize and damage genetically distinct normal host tissues. In addition to TCR signaling, costimulatory pathways are involved in T cell activation. CD27 is a TNFR family member expressed on T cells, and its ligand, CD70, is expressed on APCs. The CD27/CD70 costimulatory pathway was shown to be critical for T cell function and survival in viral infection models. However, the role of this pathway in allo-HCT is previously unknown. In this study, we have examined its contribution in GVHD pathogenesis. Surprisingly, Ab blockade of CD70 after allo-HCT significantly increases GVHD. Interestingly, whereas donor T cell- or bone marrow-derived CD70 plays no role in GVHD, host-derived CD70 inhibits GVHD as CD70 -/- hosts show significantly increased GVHD. This is evidenced by reduced survival, more severe weight loss, and increased histopathologic damage compared with wild-type hosts. In addition, CD70 -/- hosts have higher levels of proinflammatory cytokines TNF-α, IFN-γ, IL-2, and IL-17. Moreover, accumulation of donor CD4 + and CD8 + effector T cells is increased in CD70 -/- versus wild-type hosts. Mechanistic analyses suggest that CD70 expressed by host hematopoietic cells is involved in the control of alloreactive T cell apoptosis and expansion. Together, our findings demonstrate that host CD70 serves as a unique negative regulator of allogeneic T cell response by contributing to donor T cell apoptosis and inhibiting expansion of donor effector T cells. Copyright © 2017 by The American Association of Immunologists, Inc.

Calculation of the room-temperature shapes of unsymmetric laminates

NASA Technical Reports Server (NTRS)

Hyer, M. W.

1981-01-01

A theory explaining the characteristics of the cured shapes of unsymmetric laminates is presented. The theory is based on an extension of classical lamination theory which accounts for geometric nonlinearities. A Rayleigh-Ritz approach to minimizing the total potential energy is used to obtain quantitative information regarding the room temperature shapes of square T300/5208 (0(2)/90(2))T and (0(4)/90(4))T graphite-epoxy laminates. It is shown that, depending on the thickness of the laminate and the length of the side the square, the saddle shape configuration is actually unstable. For values of length and thickness that render the saddle shape unstable, it is shown that two stable cylindrical shapes exist. The predictions of the theory are compared with existing experimental data.

Lithospermic acid derivatives from Lithospermum erythrorhizon increased expression of serine palmitoyltransferase in human HaCaT cells.

PubMed

Thuong, Phuong Thien; Kang, Keon Wook; Kim, Jeong Kee; Seo, Dae Bang; Lee, Sang Jun; Kim, Sung Han; Oh, Won Keun

2009-03-15

A MeOH extract of the dry root of Lithospermum erythrorhizon showed strong increasing effect on serine palmitoyltransferase (SPT) in normal human keratinocyte cells (HaCaT cells). Bioassay-guided separation on this extract using repeated chromatography resulted in the isolation of lithospermic acid (1) and two derivative esters, 9''-methyl lithospermate (2) and 9'-methyl lithospermate (3). Compounds 1-3 significantly increased SPT expressions in the relative quantity (%) of SPT1 mRNA as well as SPT2 mRNA. These constituents also raised the level of SPT protein in HaCaT cells in a dose-dependent manner, with the increased level of SPT protein in HaCaT cells of 55%, 23%, and 81% at the concentration of 100 microg/ml, respectively. This finding suggests that lithospermic acid and its derivatives from L. erythrorhizon might improve the permeability barrier by stimulating the protein level of SPT.

The intrinsic three-dimensional shape of galactic bars

NASA Astrophysics Data System (ADS)

Méndez-Abreu, J.; Costantin, L.; Aguerri, J. A. L.; de Lorenzo-Cáceres, A.; Corsini, E. M.

2018-06-01

We present the first statistical study on the intrinsic three-dimensional (3D) shape of a sample of 83 galactic bars extracted from the CALIFA survey. We use the galaXYZ code to derive the bar intrinsic shape with a statistical approach. The method uses only the geometric information (ellipticities and position angles) of bars and discs obtained from a multi-component photometric decomposition of the galaxy surface-brightness distributions. We find that bars are predominantly prolate-triaxial ellipsoids (68%), with a small fraction of oblate-triaxial ellipsoids (32%). The typical flattening (intrinsic C/A semiaxis ratio) of the bars in our sample is 0.34, which matches well the typical intrinsic flattening of stellar discs at these galaxy masses. We demonstrate that, for prolate-triaxial bars, the intrinsic shape of bars depends on the galaxy Hubble type and stellar mass (bars in massive S0 galaxies are thicker and more circular than those in less massive spirals). The bar intrinsic shape correlates with bulge, disc, and bar parameters. In particular with the bulge-to-total (B/T) luminosity ratio, disc g - r color, and central surface brightness of the bar, confirming the tight link between bars and their host galaxies. Combining the probability distributions of the intrinsic shape of bulges and bars in our sample we show that 52% (16%) of bulges are thicker (flatter) than the surrounding bar at 1σ level. We suggest that these percentages might be representative of the fraction of classical and disc-like bulges in our sample, respectively.

Controlling The Spread of Land-Attack Cruise Missiles.

DTIC Science & Technology

1995-01-01

propellant additives and agents: (1) Bonding agents as follows: (i) tris(l-(2-methyl)aziridinyl) phosphine oxide (MAPO); (ii) trimesoyl-l(2-ethyl...Triphenyl bismuth (TPB) (ii) Isophorone diisocyanate (IPDI) (3) Burning rate modifiers as follows: (i) Catocene (ii) N-butyl- ferrocene (iii...Butacene (iv) Other ferrocene derivatives 9g Controlling the Spread of Land-Attack Cruise Missiles (4) Nitrate esters and nitrato plasticizers as

[The randomized controlled trial of influences of T shape approach on the function of knee joint in the treatment of proximal tibial fractures].

PubMed

Peng, Wei-xiong; Zhang, Zhi; Liang, Jie-hong

2008-04-01

To investigate the clinical value of T shape approach in the treatment of proximal tibial fractures. One handrend and thirteen patients of proximal tibial fractures were randomly divided into two groups. Group A: 62 cases underwent the traditional exposure approach. According to Schatzker classification,the cases of II to VI type was 25, 10, 16, 6, 5 respectively. Group B:51 cases underwent T shape approach ahead of knee joint, the cases of II to VI type was 21, 8, 13, 5, 4 respectively. All data were analyzed by SPSS 10.0 to compare operation time, blood loss, duration of hospitalization, healing time, the time of osseous union and complications after operation. Sixty patients in group A and 50 patients in group B were followed-up from 12 to 24 months. (1) Operation time:group B was longer than A (P < 0.01). (2) Mean blood loss and duration of hospitalization was the same. (3) Clinical healing time:group B was shorter. (4) Mean time of osseous union: 48 group B was shorter. Function of knee: group B was better than group A. (Complication: group B was less than group A. As compared with traditional exposure approach, T shape approach of knee joint had advantages of small scar, fewer complications, faster union of fracture and earlier recovery of joint function. The approach is valuable for the treatment of proximal tibial fractures.

A Large Program to derive the shape, cratering history and density of the largest main-belt asteroids

NASA Astrophysics Data System (ADS)

Marchis, Franck; Vernazza, Pierre; Marsset, Michael; Hanus, Josef; Carry, Benoit; Birlan, Mirel; Santana-Ros, Toni; Yang, Bin; and the Large Asteroid Survey with SPHERE (LASS)

2017-10-01

Asteroids in our solar system are metallic, rocky and/or icy objects, ranging in size from a few meters to a few hundreds of kilometers. Whereas we now possess constraints for the surface composition, albedo and rotation rate for all D≥100 km main-belt asteroids, the 3-D shape, the crater distribution, and the density have only been measured for a very limited number of these bodies (N≤10 for the first two). Characterizing these physical properties would allow us to address entirely new questions regarding the earliest stages of planetesimal formation and their subsequent collisional and dynamical evolution.ESO allocated to our program 152 hours of observations over 4 semesters to carry out disk-resolved observations of 38 large (D≥100 km) main-belt asteroids (sampling the four main compositional classes) at high angular-resolution with VLT/SPHERE throughout their rotation in order to derive their 3-D shape, the size distribution of the largest craters, and their density (PI: P. Vernazza). These measurements will allow investigating for the first time and for a modest amount of observing time the following fundamental questions: (A) Does the asteroid belt effectively hosts a large population of small bodies formed in the outer solar system? (B) Was the collisional environment in the inner solar system (at 2-3 AU) more intense than in the outer solar system (≥5AU)? (C) What was the shape of planetesimals at the end of the accretion process?We will present the goals and objectives of our program in the context of NASA 2014 Strategic Plan and the NSF decadal survey "Vision and Voyages" as well as the first observations and results collected with the SPHERE Extreme AO system. A detailed analysis of the shape modeling will be presented by Hanuš et al. in this session.

High-Temperature Shape Memory Behavior of Semicrystalline Polyamide Thermosets.

PubMed

Li, Ming; Guan, Qingbao; Dingemans, Theo J

2018-05-21

We have explored semicrystalline poly(decamethylene terephthalamide) (PA 10T) based thermosets as single-component high-temperature (>200 °C) shape memory polymers (SMPs). The PA 10T thermosets were prepared from reactive thermoplastic precursors. Reactive phenylethynyl (PE) functionalities were either attached at the chain termini or placed as side groups along the polymer main chain. The shape fixation and recovery performance of the thermoset films were investigated using a rheometer in torsion mode. By controlling the M n of the reactive oligomers, or the PE concentration of the PE side-group functionalized copolyamides, we were able to design dual-shape memory PA 10T thermosets with a broad recovery temperature range of 227-285 °C. The thermosets based on the 1000 g mol -1 reactive PE precursor and the copolyamide with 15 mol % PE side groups show the highest fixation rate (99%) and recovery rate (≥90%). High temperature triple-shape memory behavior can be achieved as well when we use the melt transition ( T m ≥ 200 °C) and the glass transition ( T g = ∼125 °C) as the two switches. The recovery rate of the two recovery steps are highly dependent on the crystallinity of the thermosets and vary within a wide range of 74%-139% and 40-82% for the two steps, respectively. Reversible shape memory events could also be demonstrated when we perform a forward and backward deformation in a triple shape memory cycle. We also studied the angular recovery velocity as a function of temperature, which provides a thermokinematic picture of the shape recovery process and helps to program for desired shape memory behavior.

Presence of IgT-C and I-A subregion-encoded determinants on distinct chains of monoclonal antigen-specific augmenting factor derived from a T cell hybridoma

PubMed Central

1983-01-01

Monoclonal antibodies specific for mouse T cell alloantigens, Tindd and Tsud, linked to the Igh-1 locus on chromosome 12, were used to directly define the antigen-binding molecule produced by a cloned hybridoma. The T cell hybridoma, FL10, was established from antigen-binding T cells of A/J mice. FL10 produces an antigen-specific augmenting T cell factor (TaF) that bears a unique I region-controlled determinant (I-A) and has antigen-binding capacity. The Tindd, but not the Tsud, determinant was detected on the surface of FL10. The presence of both Tindd and I-A subregion-controlled determinants on FL10-derived TaF was directly demonstrated by the adsorption of TaF with immunoadsorbents prepared with monoclonal antibodies. The Igh-1-linked T cell alloantigen, Tsud, was not found on TaF. Further experiments indicated that Tindd is present on the antigen-binding polypeptide chain and not on the second chain bearing the I-A determinant. Despite the presence of the Tindd determinant on hybridoma-derived TaF, augmentation induced by TaF was restricted by the H-2 type of the responding mice and not by the Igh-1 allotype. PMID:6189953

Enhancement of the thermoelectric efficiency in a T-shaped quantum dot system in the linear and nonlinear regimes

NASA Astrophysics Data System (ADS)

Gómez-Silva, G.; Orellana, P. A.; Anda, E. V.

2018-02-01

In the present work, we investigate the thermoelectric properties of a T-shaped double quantum dot system coupled to two metallic leads incorporating the intra-dot Coulomb interaction. We explore the role of the interference effects and Coulomb blockade on the thermoelectric efficiency of the system in the linear and nonlinear regimes. We studied as well the effect of a Van-Hove singularity of the leads density of states (DOS) at the neighborhood of the Fermi energy, a situation that can be obtained using a carbon nanotube, a graphene nano-ribbon or other contacts with one-dimensional properties. The system is studied above the Kondo temperature. The Coulomb blockade of the electronic charges is studied using the Hubbard III approximation, which properly describes the transport properties of this regime. In the linear response, our results show an enhancement of the thermopower and the figure of merit of the system. For a nonlinear situation, we calculate the thermoelectric efficiency and power output, concluding that the T-shaped double quantum dot is an efficient thermoelectric device. Moreover, we demonstrate the great importance of the DOS Van-Hove singularity at the neighborhood of the Fermi energy to obtain a very significant increase in the thermoelectric efficiency of the system.

A Continuum Mechanical Approach to Geodesics in Shape Space

DTIC Science & Technology

2010-01-01

the space of shapes, where shapes are implicitly described as boundary contours of objects. The proposed shape metric is derived from a ...investigate the close link between abstract geometry on the infinite -dimen- sional space of shapes and the continuum mechanical view of shapes as boundary...are texture-coded in the bottom row. of multiple components of volumetric objects. The

Menstrual Blood as a Potential Source of Endometrial Derived CD3+ T Cells

PubMed Central

Sabbaj, Steffanie; Hel, Zdenek; Richter, Holly E.; Mestecky, Jiri; Goepfert, Paul A.

2011-01-01

Studies of T cell-mediated immunity in the human female genital tract have been problematic due to difficulties associated with the collection of mucosal samples. Consequently, most studies rely on biopsies from the lower female genital tract or remnant tissue from hysterectomies. Availability of samples from healthy women is limited, as most studies are carried out in women with underlying pathologies. Menstruation is the cyclical sloughing off of endometrial tissue, and thus it should be a source of endometrial cells without the need for a biopsy. We isolated and phenotyped T cells from menstrual and peripheral blood and from endometrial biopsy-derived tissue from healthy women to determine the types of T cells present in this compartment. Our data demonstrated that T cells isolated from menstrual blood are a heterogeneous population of cells with markers reminiscent of blood and mucosal cells as well as unique phenotypes not represented in either compartment. T cells isolated from menstrual blood expressed increased levels of HLA-DR, αEβ7 and CXCR4 and reduced levels of CD62L relative to peripheral blood. Menstrual blood CD4+ T cells were enriched for cells expressing both CCR7 and CD45RA, markers identifying naïve T cells and were functional as determined by antigen-specific intracellular cytokine production assays. These data may open new avenues of investigation for cell mediated immune studies involving the female reproductive tract without the need for biopsies. PMID:22174921

Characteristics of traffic flow at nonsignalized T-shaped intersection with U-turn movements.

PubMed

Fan, Hong-Qiang; Jia, Bin; Li, Xin-Gang; Tian, Jun-Fang; Yan, Xue-Dong

2013-01-01

Most nonsignalized T-shaped intersections permit U-turn movements, which make the traffic conditions of intersection complex. In this paper, a new cellular automaton (CA) model is proposed to characterize the traffic flow at the intersection of this type. In present CA model, new rules are designed to avoid the conflicts among different directional vehicles and eliminate the gridlock. Two kinds of performance measures (i.e., flux and average control delay) for intersection are compared. The impacts of U-turn movements are analyzed under different initial conditions. Simulation results demonstrate that (i) the average control delay is more practical than flux in measuring the performance of intersection, (ii) U-turn movements increase the range and degree of high congestion, and (iii) U-turn movements on the different direction of main road have asymmetrical influences on the traffic conditions of intersection.

Derivation of Thymic Lymphoma T-cell Lines from Atm-/- and p53-/- Mice

PubMed Central

Jinadasa, Rasika; Balmus, Gabriel; Gerwitz, Lee; Roden, Jamie; Weiss, Robert; Duhamel, Gerald

2011-01-01

Established cell lines are a critical research tool that can reduce the use of laboratory animals in research. Certain strains of genetically modified mice, such as Atm-/- and p53-/- consistently develop thymic lymphoma early in life 1,2, and thus, can serve as a reliable source for derivation of murine T-cell lines. Here we present a detailed protocol for the development of established murine thymic lymphoma T-cell lines without the need to add interleukins as described in previous protocols 1,3. Tumors were harvested from mice aged three to six months, at the earliest indication of visible tumors based on the observation of hunched posture, labored breathing, poor grooming and wasting in a susceptible strain 1,4. We have successfully established several T-cell lines using this protocol and inbred strains ofAtm-/- [FVB/N-Atmtm1Led/J] 2 and p53-/- [129/S6-Trp53tm1Tyj/J] 5 mice. We further demonstrate that more than 90% of the established T-cell population expresses CD3, CD4 and CD8. Consistent with stably established cell lines, the T-cells generated by using the present protocol have been passaged for over a year. PMID:21490582

Cytolytic activity in T cell clones derived from human synovial rheumatoid membrane: inhibition by synovial fluid.

PubMed Central

Miltenburg, A M; Van Laar, J M; De Kuiper, P; Daha, M R; Breedveld, F C

1990-01-01

A panel of T cell clones was derived from the synovial membrane of a patient with rheumatoid arthritis (RA). We investigated whether T cell clones with cytolytic properties were present and whether T cell cytotoxicity was influenced by the presence of synovial fluid. These issues were studied using anti-CD3 and lectin-induced cytotoxicity assays. The majority of the T cell clones derived from the synovial membrane showed cytotoxic properties although non-cytotoxic clones were also found. Three clones (N11, N6 and N15) showed strong cytotoxicity (more than 40% lysis at an effector-to-target cell ratio of 10:1) whereas three clones (N16, N4 and N14) were non-cytotoxic (less than 20% lysis at an effector-to-target cell ratio of 10:1). The induction of cytotoxicity in the anti-CD3-driven system was shown to be dependent on the dose of anti-CD3 present. When synovial fluid was added to these assays a strong inhibition of cytotoxicity was found. This inhibition of cytotoxicity was found with synovial fluid samples of RA patients, as well as with non-RA synovial fluids. Both anti-CD3 and lectin-dependent cytotoxicity assays were strongly inhibited. In conclusion, T cell clones with cytotoxic activity can be isolated from rheumatoid synovial membrane. In the presence of synovial fluid these cytotoxic cells are inhibited to exert their cytotoxic function. PMID:2148285

The Case for the L-Shaped Classroom.

ERIC Educational Resources Information Center

Dyck, James A.

1994-01-01

Classroom shape is an important variable in educational quality. The traditional squat rectangle may be counterproductive to the learning process. The fat L-shaped classroom, compared to H, X, and T shapes, offers good separation, is more compact, and provides good visibility and ease of movement for the teacher. It has excellent nesting…

Tailor Made Synthesis of T-Shaped and π-STACKED Dimers in the Gas Phase: Concept for Efficient Drug Design and Material Synthesis

NASA Astrophysics Data System (ADS)

Kumar, Sumit; Das, Aloke

2013-06-01

Non-covalent interactions play a key role in governing the specific functional structures of biomolecules as well as materials. Thus molecular level understanding of these intermolecular interactions can help in efficient drug design and material synthesis. It has been found from X-ray crystallography that pure hydrocarbon solids (i.e. benzene, hexaflurobenzene) have mostly slanted T-shaped (herringbone) packing arrangement whereas mixed solid hydrocarbon crystals (i.e. solid formed from mixtures of benzene and hexafluorobenzene) exhibit preferentially parallel displaced (PD) π-stacked arrangement. Gas phase spectroscopy of the dimeric complexes of the building blocks of solid pure benzene and mixed benzene-hexafluorobenzene adducts exhibit similar structural motifs observed in the corresponding crystal strcutures. In this talk, I will discuss about the jet-cooled dimeric complexes of indole with hexafluorobenzene and p-xylene in the gas phase using Resonant two photon ionzation and IR-UV double resonance spectroscopy combined with quantum chemistry calculations. In stead of studying benzene...p-xylene and benzene...hexafluorobenzene dimers, we have studied corresponding indole complexes because N-H group is much more sensitive IR probe compared to C-H group. We have observed that indole...hexafluorobenzene dimer has parallel displaced (PD) π-stacked structure whereas indole...p-xylene has slanted T-shaped structure. We have shown here selective switching of dimeric structure from T-shaped to π-stacked by changing the substituent from electron donating (-CH3) to electron withdrawing group (fluorine) in one of the complexing partners. Thus, our results demonstrate that efficient engineering of the non-covalent interactions can lead to efficient drug design and material synthesis.

Syringaresinol: A Renewable and Safer Alternative to Bisphenol A for Epoxy-Amine Resins.

PubMed

Janvier, Marine; Hollande, Louis; Jaufurally, Abdus Samad; Pernes, Miguel; Ménard, Raphaël; Grimaldi, Marina; Beaugrand, Johnny; Balaguer, Patrick; Ducrot, Paul-Henri; Allais, Florent

2017-02-22

A renewable bisepoxide, SYR-EPO, was prepared from syringaresinol, a naturally occurring bisphenol deriving from sinapic acid, by using a chemo-enzymatic synthetic pathway. Estrogenic activity tests revealed no endocrine disruption for syringaresinol. Its glycidylation afforded SYR-EPO with excellent yield and purity. This biobased, safe epoxy precursor was then cured with conventional and renewable diamines for the preparation of epoxy-amine resins. The resulting thermosets were thermally and mechanically characterized. Thermal analyses of these new resins showed excellent thermal stabilities (T d5 % =279-309 °C) and T g ranging from 73 to 126 °C, almost reaching the properties of those obtained with the diglycidylether of bisphenol A (DGEBA), extensively used in the polymer industry (T d5 % =319 °C and T g =150 °C for DGEBA/isophorone diamine resins). Degradation studies in NaOH and HCl aqueous solutions also highlighted the robustness of the syringaresinol-based resins, similar to bisphenol A (BPA). All these results undoubtedly confirmed the potential of syringaresinol as a greener and safer substitute for BPA. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Computational Model of Multidimensional Shape

PubMed Central

Liu, Xiuwen; Shi, Yonggang; Dinov, Ivo

2010-01-01

We develop a computational model of shape that extends existing Riemannian models of curves to multidimensional objects of general topological type. We construct shape spaces equipped with geodesic metrics that measure how costly it is to interpolate two shapes through elastic deformations. The model employs a representation of shape based on the discrete exterior derivative of parametrizations over a finite simplicial complex. We develop algorithms to calculate geodesics and geodesic distances, as well as tools to quantify local shape similarities and contrasts, thus obtaining a formulation that accounts for regional differences and integrates them into a global measure of dissimilarity. The Riemannian shape spaces provide a common framework to treat numerous problems such as the statistical modeling of shapes, the comparison of shapes associated with different individuals or groups, and modeling and simulation of shape dynamics. We give multiple examples of geodesic interpolations and illustrations of the use of the models in brain mapping, particularly, the analysis of anatomical variation based on neuroimaging data. PMID:21057668

Shape transition with temperature of the pear-shaped nuclei in covariant density functional theory

DOE PAGES

Zhang, Wei; Niu, Yi-Fei

2017-11-10

The shape evolutions of the pear-shaped nucleimore » $$^{224}$$Ra and even-even $$^{144-154}$$Ba with temperature are investigated by the finite-temperature relativistic mean field theory with the treatment of pairing correlations by the BCS approach. We study the free energy surfaces as well as the bulk properties including deformations, pairing gaps, excitation energy, and specific heat for the global minimum. For $$^{224}$$Ra, three discontinuities found in the specific heat curve indicate the pairing transition at temperature 0.4 MeV, and two shape transitions at temperatures 0.9 and 1.0 MeV, namely one from quadrupole-octupole deformed to quadrupole deformed, and the other from quadrupole deformed to spherical. Furthermore, the gaps at $N$=136 and $Z$=88 are responsible for stabilizing the octupole-deformed global minimum at low temperatures. Similar pairing transition at $$T\\sim$$0.5 MeV and shape transitions at $T$=0.5-2.2 MeV are found for even-even $$^{144-154}$$Ba. Finally, the transition temperatures are roughly proportional to the corresponding deformations at the ground states.« less

Computational properties of mitochondria in T cell activation and fate

PubMed Central

Dupont, Geneviève

2016-01-01

In this article, we review how mitochondrial Ca2+ transport (mitochondrial Ca2+ uptake and Na+/Ca2+ exchange) is involved in T cell biology, including activation and differentiation through shaping cellular Ca2+ signals. Based on recent observations, we propose that the Ca2+ crosstalk between mitochondria, endoplasmic reticulum and cytoplasm may form a proportional–integral–derivative (PID) controller. This PID mechanism (which is well known in engineering) could be responsible for computing cellular decisions. In addition, we point out the importance of analogue and digital signal processing in T cell life and implication of mitochondrial Ca2+ transport in this process. PMID:27852805

Computational properties of mitochondria in T cell activation and fate.

PubMed

Uzhachenko, Roman; Shanker, Anil; Dupont, Geneviève

2016-11-01

In this article, we review how mitochondrial Ca 2+ transport (mitochondrial Ca 2+ uptake and Na + /Ca 2+ exchange) is involved in T cell biology, including activation and differentiation through shaping cellular Ca 2+ signals. Based on recent observations, we propose that the Ca 2+ crosstalk between mitochondria, endoplasmic reticulum and cytoplasm may form a proportional-integral-derivative (PID) controller. This PID mechanism (which is well known in engineering) could be responsible for computing cellular decisions. In addition, we point out the importance of analogue and digital signal processing in T cell life and implication of mitochondrial Ca 2+ transport in this process. © 2016 The Authors.

Tumor-derived exosomes regulate expression of immune function-related genes in human T cell subsets.

PubMed

Muller, Laurent; Mitsuhashi, Masato; Simms, Patricia; Gooding, William E; Whiteside, Theresa L

2016-02-04

Tumor cell-derived exosomes (TEX) suppress functions of immune cells. Here, changes in the gene profiles of primary human T lymphocytes exposed in vitro to exosomes were evaluated. CD4(+) Tconv, CD8(+) T or CD4(+) CD39(+) Treg were isolated from normal donors' peripheral blood and co-incubated with TEX or exosomes isolated from supernatants of cultured dendritic cells (DEX). Expression levels of 24-27 immune response-related genes in these T cells were quantified by qRT-PCR. In activated T cells, TEX and DEX up-regulated mRNA expression levels of multiple genes. Multifactorial data analysis of ΔCt values identified T cell activation and the immune cell type, but not exosome source, as factors regulating gene expression by exosomes. Treg were more sensitive to TEX-mediated effects than other T cell subsets. In Treg, TEX-mediated down-regulation of genes regulating the adenosine pathway translated into high expression of CD39 and increased adenosine production. TEX also induced up-regulation of inhibitory genes in CD4(+) Tconv, which translated into a loss of CD69 on their surface and a functional decline. Exosomes are not internalized by T cells, but signals they carry and deliver to cell surface receptors modulate gene expression and functions of human T lymphocytes.

When Deriving the Spatial QRS-T Angle from the 12-lead ECG, which Transform is More Frank: Regression or Inverse Dower?

NASA Technical Reports Server (NTRS)

Schlegel, Todd T.; Cortez, Daniel

2010-01-01

Our primary objective was to ascertain which commonly used 12-to-Frank-lead transformation yields spatial QRS-T angle values closest to those obtained from simultaneously collected true Frank-lead recordings. Simultaneous 12-lead and Frank XYZ-lead recordings were analyzed for 100 post-myocardial infarction patients and 50 controls. Relative agreement, with true Frank-lead results, of 12-to-Frank-lead transformed results for the spatial QRS-T angle using Kors regression versus inverse Dower was assessed via ANOVA, Lin s concordance and Bland-Altman plots. Spatial QRS-T angles from the true Frank leads were not significantly different than those derived from the Kors regression-related transformation but were significantly smaller than those derived from the inverse Dower-related transformation (P less than 0.001). Independent of method, spatial mean QRS-T angles were also always significantly larger than spatial maximum (peaks) QRS-T angles. Spatial QRS-T angles are best approximated by regression-related transforms. Spatial mean and spatial peaks QRS-T angles should also not be used interchangeably.

Kinetic Shapes: Analysis, Verification, and Applications.

PubMed

Handz̆ić, Ismet; Reed, Kyle B

2014-06-01

A circular shape placed on an incline will roll; similarly, an irregularly shaped object, such as the Archimedean spiral, will roll on a flat surface when a force is applied to its axle. This rolling is dependent on the specific shape and the applied force (magnitude and location). In this paper, we derive formulas that define the behavior of irregular 2D and 3D shapes on a flat plane when a weight is applied to the shape's axle. These kinetic shape (KS) formulas also define and predict shapes that exert given ground reaction forces when a known weight is applied at the axle rotation point. Three 2D KS design examples are physically verified statically with good correlation to predicted values. Motion simulations of unrestrained 2D KS yielded expected results in shape dynamics and self-stabilization. We also put forth practical application ideas and research for 2D and 3D KS such as in robotics and gait rehabilitation.

Multifunctional shape-memory polymers.

PubMed

Behl, Marc; Razzaq, Muhammad Yasar; Lendlein, Andreas

2010-08-17

The thermally-induced shape-memory effect (SME) is the capability of a material to change its shape in a predefined way in response to heat. In shape-memory polymers (SMP) this shape change is the entropy-driven recovery of a mechanical deformation, which was obtained before by application of external stress and was temporarily fixed by formation of physical crosslinks. The high technological significance of SMP becomes apparent in many established products (e.g., packaging materials, assembling devices, textiles, and membranes) and the broad SMP development activities in the field of biomedical as well as aerospace applications (e.g., medical devices or morphing structures for aerospace vehicles). Inspired by the complex and diverse requirements of these applications fundamental research is aiming at multifunctional SMP, in which SME is combined with additional functions and is proceeding rapidly. In this review different concepts for the creation of multifunctionality are derived from the various polymer network architectures of thermally-induced SMP. Multimaterial systems, such as nanocomposites, are described as well as one-component polymer systems, in which independent functions are integrated. Future challenges will be to transfer the concept of multifunctionality to other emerging shape-memory technologies like light-sensitive SMP, reversible shape changing effects or triple-shape polymers.

CD8+ memory T-cell inflation renders compromised CD4+ T-cell-dependent CD8+ T-cell immunity via naïve T-cell anergy.

PubMed

Xu, Aizhang; Freywald, Andrew; Xie, Yufeng; Li, Zejun; Xiang, Jim

2017-01-01

Whether inflation of CD8 + memory T (mT) cells, which is often derived from repeated prime-boost vaccinations or chronic viral infections in the elderly, would affect late CD8 + T-cell immunity is a long-standing paradox. We have previously established an animal model with mT-cell inflation by transferring ConA-stimulated monoclonal CD8 + T cells derived from Ova-specific T-cell-receptor transgenic OTI mice into irradiation-induced lymphopenic B6 mice. In this study, we also established another two animal models with mT-cell inflation by transferring, 1) ConA-stimulated monoclonal CD8 + T cells derived from lymphocytic choriomeningitis virus glycoprotein-specific T-cell-receptor transgenic P14 mice, and 2) ConA-stimulated polyclonal CD8 + T cells derived from B6.1 mice into B6 mice with irradiation-induced lymphopenia. We vaccinated these mice with recombinant Ova-expressing Listeria monocytogenes and Ova-pulsed dendritic cells, which stimulated CD4 + T cell-independent and CD4 + T-cell-dependent CD8 + T-cell responses, respectively, and assessed Ova-specific CD8 + T-cell responses by flow cytometry. We found that Ova-specific CD8 + T-cell responses derived from the latter but not the former vaccination were significantly reduced in mice with CD8 + mT-cell inflation compared to wild-type B6 mice. We determined that naïve CD8 + T cells purified from splenocytes of mice with mT-cell inflation had defects in cell proliferation upon stimulation in vitro and in vivo and upregulated T-cell anergy-associated Itch and GRAIL molecules. Taken together, our data reveal that CD8 + mT-cell inflation renders compromised CD4 + T-cell-dependent CD8 + T-cell immunity via naïve T-cell anergy, and thus show promise for the design of efficient vaccines for elderly patients with CD8 + mT-cell inflation.

Structural characteristics of a gas-liquid flow in a microchannel with a T-shaped mixer

NASA Astrophysics Data System (ADS)

Kuznetsov, V. V.; Kozulin, I. A.

2017-11-01

The results of experimental studies of the structural characteristics of a nitrogen-water mixture flow in a horizontal microchannel provided with a T-shaped mixer are presented. The experiments are performed in a channel with a rectangular cross section of 250 × 315 μm under the conditions of a dominating influence of capillary forces. Structural characteristics of the flow are determined using the two-beam laser scanning and high-speed video capture at a distance of 500 calibers from the inlet in a wide range of reduced gas- and liquid-flow rates. A new method for the identification of flow regimes is proposed based on the statistical treatment of the laser-scanning data, and a map of flow patterns is constructed.

Immunosuppressive Mesenchymal Stromal Cells Derived from Human-Induced Pluripotent Stem Cells Induce Human Regulatory T Cells In Vitro and In Vivo

PubMed Central

Roux, Clémence; Saviane, Gaëlle; Pini, Jonathan; Belaïd, Nourhène; Dhib, Gihen; Voha, Christine; Ibáñez, Lidia; Boutin, Antoine; Mazure, Nathalie M.; Wakkach, Abdelilah; Blin-Wakkach, Claudine; Rouleau, Matthieu

2018-01-01

Despite mesenchymal stromal cells (MSCs) are considered as a promising source of cells to modulate immune functions on cells from innate and adaptive immune systems, their clinical use remains restricted (few number, limited in vitro expansion, absence of a full phenotypic characterization, few insights on their in vivo fate). Standardized MSCs derived in vitro from human-induced pluripotent stem (huIPS) cells, remediating part of these issues, are considered as well as a valuable tool for therapeutic approaches, but their functions remained to be fully characterized. We generated multipotent MSCs derived from huiPS cells (huiPS-MSCs), and focusing on their immunosuppressive activity, we showed that human T-cell activation in coculture with huiPS-MSCs was significantly reduced. We also observed the generation of functional CD4+ FoxP3+ regulatory T (Treg) cells. Further tested in vivo in a model of human T-cell expansion in immune-deficient NSG mice, huiPS-MSCs immunosuppressive activity prevented the circulation and the accumulation of activated human T cells. Intracytoplasmic labeling of cytokines produced by the recovered T cells showed reduced percentages of human-differentiated T cells producing Th1 inflammatory cytokines. By contrast, T cells producing IL-10 and FoxP3+-Treg cells, absent in non-treated animals, were detected in huiPS-MSCs treated mice. For the first time, these results highlight the immunosuppressive activity of the huiPS-MSCs on human T-cell stimulation with a concomitant generation of human Treg cells in vivo. They may favor the development of new tools and strategies based on the use of huiPS cells and their derivatives for the induction of immune tolerance. PMID:29422893

Immunosuppressive Mesenchymal Stromal Cells Derived from Human-Induced Pluripotent Stem Cells Induce Human Regulatory T Cells In Vitro and In Vivo.

PubMed

Roux, Clémence; Saviane, Gaëlle; Pini, Jonathan; Belaïd, Nourhène; Dhib, Gihen; Voha, Christine; Ibáñez, Lidia; Boutin, Antoine; Mazure, Nathalie M; Wakkach, Abdelilah; Blin-Wakkach, Claudine; Rouleau, Matthieu

2017-01-01

Despite mesenchymal stromal cells (MSCs) are considered as a promising source of cells to modulate immune functions on cells from innate and adaptive immune systems, their clinical use remains restricted (few number, limited in vitro expansion, absence of a full phenotypic characterization, few insights on their in vivo fate). Standardized MSCs derived in vitro from human-induced pluripotent stem (huIPS) cells, remediating part of these issues, are considered as well as a valuable tool for therapeutic approaches, but their functions remained to be fully characterized. We generated multipotent MSCs derived from huiPS cells (huiPS-MSCs), and focusing on their immunosuppressive activity, we showed that human T-cell activation in coculture with huiPS-MSCs was significantly reduced. We also observed the generation of functional CD4 + FoxP3 + regulatory T (Treg) cells. Further tested in vivo in a model of human T-cell expansion in immune-deficient NSG mice, huiPS-MSCs immunosuppressive activity prevented the circulation and the accumulation of activated human T cells. Intracytoplasmic labeling of cytokines produced by the recovered T cells showed reduced percentages of human-differentiated T cells producing Th1 inflammatory cytokines. By contrast, T cells producing IL-10 and FoxP3 + -Treg cells, absent in non-treated animals, were detected in huiPS-MSCs treated mice. For the first time, these results highlight the immunosuppressive activity of the huiPS-MSCs on human T-cell stimulation with a concomitant generation of human Treg cells in vivo . They may favor the development of new tools and strategies based on the use of huiPS cells and their derivatives for the induction of immune tolerance.

Fabrication, Characterization and Cytotoxicity of Spherical-Shaped Conjugated Gold-Cockle Shell Derived Calcium Carbonate Nanoparticles for Biomedical Applications

NASA Astrophysics Data System (ADS)

Kiranda, Hanan Karimah; Mahmud, Rozi; Abubakar, Danmaigoro; Zakaria, Zuki Abubakar

2018-01-01

The evolution of nanomaterial in science has brought about a growing increase in nanotechnology, biomedicine, and engineering fields. This study was aimed at fabrication and characterization of conjugated gold-cockle shell-derived calcium carbonate nanoparticles (Au-CSCaCO3NPs) for biomedical application. The synthetic technique employed used gold nanoparticle citrate reduction method and a simple precipitation method coupled with mechanical use of a Programmable roller-ball mill. The synthesized conjugated nanomaterial was characterized for its physicochemical properties using transmission electron microscope (TEM), field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR). However, the intricacy of cellular mechanisms can prove challenging for nanomaterial like Au-CSCaCO3NPs and thus, the need for cytotoxicity assessment. The obtained spherical-shaped nanoparticles (light-green purplish) have an average diameter size of 35 ± 16 nm, high carbon and oxygen composition. The conjugated nanomaterial, also possesses a unique spectra for aragonite polymorph and carboxylic bond significantly supporting interactions between conjugated nanoparticles. The negative surface charge and spectra absorbance highlighted their stability. The resultant spherical shaped conjugated Au-CSCaCO3NPs could be a great nanomaterial for biomedical applications.

Synthesis, crystal structure and photo physical properties of isomeric fluorinated s-shaped polyaromatic dibenzo[c,l]chrysene derivatives

NASA Astrophysics Data System (ADS)

Moriguchi, Tetsuji; Tabuchi, Daichi; Yakeya, Daisuke; Tsuge, Akihiko; Jalli, Venkataprasad; Yoza, Kenji

2018-01-01

Two s-shaped fluorinated isomeric polyaromatic dibenzo[c,l]chrysene derivatives have been synthesized by a two step process using the Wittig, Heck and iodine promoted cyclization reactions. These cyclized compounds were characterized by 1H NMR and EI-MS. Further, absolute configurations of isomeric 4a and 4b were determined by X-ray diffraction analysis. Compound 4a crystallized under monoclinic system with space group P21/c and compound 4b crystallized under monoclinic system with space group Cc. They have good solubility in common organic solvents such as dichloromethane, chloroform and THF. Photophysical properties of 4a and 4b were evaluated by using UV-Visible and Fluorescence spectrophotometer. Compounds 4a and 4b showed strong absorption maximum wavelength at 317 nm. The emission spectra of 4a and 4b displayed sharp peaks in the visible region from 417 to 441 nm. The shape of the UV-Visible and Fluorescence spectra of 4a and 4b looks almost identical. But compound 4a exhibited better fluorescence intensity than compound 4b. This difference may be due to the difference in the configuration of compounds 4a and 4b.

Atopic dermatitis induces the expansion of thymus-derived regulatory T cells exhibiting a Th2-like phenotype in mice.

PubMed

Moosbrugger-Martinz, Verena; Tripp, Christoph H; Clausen, Björn E; Schmuth, Matthias; Dubrac, Sandrine

2016-05-01

Atopic dermatitis (AD) is a widespread inflammatory skin disease with an early onset, characterized by pruritus, eczematous lesions and skin dryness. This chronic relapsing disease is believed to be primarily a result of a defective epidermal barrier function associated with genetic susceptibility, immune hyper-responsiveness of the skin and environmental factors. Although the important role of abnormal immune reactivity in the pathogenesis of AD is widely accepted, the role of regulatory T cells (Tregs) remains elusive. We found that the Treg population is expanded in a mouse model of AD, i.e. mice topically treated with vitamin D3 (VitD). Moreover, mice with AD-like symptoms exhibit increased inducible T-cell costimulator (ICOS)-, cytotoxic T-lymphocyte antigen-4 (CTLA-4)- and Glycoprotein-A repetitions predominant receptor (GARP)-expressing Tregs in skin-draining lymph nodes. Importantly, the differentiation of Tregs into thymus-derived Tregs is favoured in our mouse model of AD. Emigrated skin-derived dendritic cells are required for Treg induction and Langerhans cells are responsible for the biased expansion of thymus-derived Tregs . Intriguingly, thymus-derived Tregs isolated from mice with AD-like symptoms exhibit a Th2 cytokine profile. Thus, AD might favour the expansion of pathogenic Tregs able to produce Th2 cytokines and to promote the disease instead of alleviating symptoms. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

[Case-control study on T-shaped locking internal fixation and external fixation for the treatment of dorsal Barton's fracture].

PubMed

Chen, Huan-qing; Wen, Xi-le; Li, Yang-ming; Wen, Cong-you

2015-06-01

To compare clinical effect of T-shaped locking internal fixation and external fixation in treating dorsal Barton's fracture,and investigate selective strategy of internal fixation. From January 2008 to January 2013, 100 patients with dorsal Barton's fracture were randomly divided into two groups. In treatment group, there were 30 males and 20 females with an average age of (33.8±3.6) years old;30 cases were type B, 20 cases were type C;and treated with T-shaped locking internal fixation. In control group, there were 32 male and 18 females with an average age of (32.9±3.4) years old; 29 cases were type B, 21 cases were type C; and treated with external fixation. Volar tilt, ulnar deviation and radial height at 3 months after operation were detected and compared between two groups. Mechara functional evaluation were used to evaluate postoperative clinical effects. Clinical cure time, postoperative complications,joint mobility and function score were recorded and compared between two groups. In treatment group,volar tilt was (11.9±2.7)°, ulnar deviation was (20.8+ 2.9)°,and radial height was (10.9±1.8) mm; while volar tilt was (9.1±1.6)°, ulnar deviation was (17.1±2.9)°, and radial height was (8.1±1.5) mm in control group. Treatment group was better than control group in volar tilt, ulnar deviation and radial height. Clinical cure time in treatment group was(12.0±2.3) weeks, shorter than control group (18.0±4.1) weeks. The incidence of complications in treatment group was lower than control group. According to Mehara functional evaluation,20 cases got excellent results, 25 good, 3 moderate and 2 poor in treatment group; 16 cases got excellent results, 14 good, 10 moderate and 10 poor in control group. Treatment group was better than control group in clinical effects. T-shaped locking internal fixation with postoperative functional exercise for the treatment of dorsal Barton's fracture fits for biomechanics demands,and has advantages of stable fixation

3D Printed Silicones with Shape Memory

DOE PAGES

Wu, Amanda S.; Small IV, Ward; Bryson, Taylor M.; ...

2017-07-05

Direct ink writing enables the layer-by-layer manufacture of ordered, porous structures whose mechanical behavior is driven by architecture and material properties. Here, we incorporate two different gas filled microsphere pore formers to evaluate the effect of shell stiffness and T g on compressive behavior and compression set in siloxane matrix printed structures. The lower T g microsphere structures exhibit substantial compression set when heated near and above T g, with full structural recovery upon reheating without constraint. By contrast, the higher T g microsphere structures exhibit reduced compression set with no recovery upon reheating. Aside from their role in tuningmore » the mechanical behavior of direct ink write structures, polymer microspheres are good candidates for shape memory elastomers requiring structural complexity, with potential applications toward tandem shape memory polymers.« less

3D Printed Silicones with Shape Memory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Amanda S.; Small IV, Ward; Bryson, Taylor M.

Direct ink writing enables the layer-by-layer manufacture of ordered, porous structures whose mechanical behavior is driven by architecture and material properties. Here, we incorporate two different gas filled microsphere pore formers to evaluate the effect of shell stiffness and T g on compressive behavior and compression set in siloxane matrix printed structures. The lower T g microsphere structures exhibit substantial compression set when heated near and above T g, with full structural recovery upon reheating without constraint. By contrast, the higher T g microsphere structures exhibit reduced compression set with no recovery upon reheating. Aside from their role in tuningmore » the mechanical behavior of direct ink write structures, polymer microspheres are good candidates for shape memory elastomers requiring structural complexity, with potential applications toward tandem shape memory polymers.« less

MHC drives TCR repertoire shaping, but not maturation, in recent thymic emigrants1

PubMed Central

Houston, Evan G.; Fink, Pamela J.

2009-01-01

After developing in the thymus, recent thymic emigrants (RTEs) enter the lymphoid periphery and undergo a maturation process as they transition into the mature naïve (MN) T cell compartment. This maturation presumably shapes RTEs into a pool of T cells best fit to function robustly in the periphery without causing autoimmunity; however, the mechanism and consequences of this maturation process remain unknown. Using a transgenic mouse system that specifically labels RTEs, we tested the influence of MHC molecules, key drivers of intrathymic T cell selection and naive peripheral T cell homeostasis, in shaping the RTE pool in the lymphoid periphery. We found that the TCRs expressed by RTEs are skewed to longer CDR3 regions compared to those of MN T cells, suggesting that MHC does streamline the TCR repertoire of T cells as they transition from the RTE to the MN T cell stage. This conclusion is borne out in studies in which the representation of individual TCRs was followed as a function of time since thymic egress. Surprisingly, we found that MHC is dispensable for the phenotypic and functional maturation of RTEs. This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript. This version of the manuscript has not yet been copyedited or subjected to editorial proofreading by The JI; hence, it may differ from the final version published in The JI (online and in print). AAI (The JI) is not liable for errors or omissions in this author-produced version of the manuscript or in any version derived from it by the U.S. National Institutes of Health or any other third party. The final, citable version of record can be found at www.jimmunol.org PMID:19915060

A Metric on Phylogenetic Tree Shapes

PubMed Central

Plazzotta, G.

2018-01-01

Abstract The shapes of evolutionary trees are influenced by the nature of the evolutionary process but comparisons of trees from different processes are hindered by the challenge of completely describing tree shape. We present a full characterization of the shapes of rooted branching trees in a form that lends itself to natural tree comparisons. We use this characterization to define a metric, in the sense of a true distance function, on tree shapes. The metric distinguishes trees from random models known to produce different tree shapes. It separates trees derived from tropical versus USA influenza A sequences, which reflect the differing epidemiology of tropical and seasonal flu. We describe several metrics based on the same core characterization, and illustrate how to extend the metric to incorporate trees’ branch lengths or other features such as overall imbalance. Our approach allows us to construct addition and multiplication on trees, and to create a convex metric on tree shapes which formally allows computation of average tree shapes. PMID:28472435

Abnormal subcortical nuclei shapes in patients with type 2 diabetes mellitus.

PubMed

Chen, Ji; Zhang, Junxiang; Liu, Xuebing; Wang, Xiaoyang; Xu, Xiangjin; Li, Hui; Cao, Bo; Yang, Yanqiu; Lu, Jingjing; Chen, Ziqian

2017-10-01

Type 2 diabetes mellitus (T2DM) increases the risk of brain atrophy and dementia. We aimed to elucidate deep grey matter (GM) structural abnormalities and their relationships with T2DM cognitive deficits by combining region of interest (ROI)-based volumetry, voxel-based morphometry (VBM) and shape analysis. We recruited 23 T2DM patients and 24 age-matched healthy controls to undergo T1-weighted structural MRI scanning. Images were analysed using the three aforementioned methods to obtain deep GM structural shapes and volumes. Biochemical and cognitive assessments were made and were correlated with the resulting metrics. Shape analysis revealed that T2DM is associated with focal atrophy in the bilateral caudate head and dorso-medial part of the thalamus. ROI-based volumetry only detected thalamic volume reduction in T2DM when compared to the controls. No significant between-group differences were found by VBM. Furthermore, a worse performance of cognitive processing speed correlated with more severe GM atrophy in the bilateral dorso-medial part of the thalamus. Also, the GM volume in the bilateral dorso-medial part of the thalamus changed negatively with HbA 1c . Shape analysis is sensitive in identifying T2DM deep GM structural abnormalities and their relationships with cognitive impairments, which may greatly assist in clarifying the neural substrate of T2DM cognitive dysfunction. • Type 2 diabetes mellitus is accompanied with brain atrophy and cognitive dysfunction • Deep grey matter structures are essential for multiple cognitive processes • Shape analysis revealed local atrophy in the dorso-medial thalamus and caudatum in patients • Dorso-medial thalamic atrophy correlated to cognitive processing speed slowing and high HbA1c. • Shape analysis has advantages in unraveling neural substrates of diabetic cognitive deficits.

An evaluation on the design of beam shaping assembly based on the D-T reaction for BNCT

NASA Astrophysics Data System (ADS)

Asnal, M.; Liamsuwan, T.; Onjun, T.

2015-05-01

Boron Neutron Capture Therapy (BNCT) can be achieved by using a compact neutron generator such as a compact D-T neutron source, in which neutron energy must be in the epithermal energy range with sufficient flux. For these requirements, a Beam Shaping Assembly (BSA) is needed. In this paper, three BSA designs based on the D-T reaction for BNCT are discussed. It is found that the BSA configuration designed by Rasouli et al. satisfies all of the International Atomic Energy Agency (IAEA) criteria. It consists of 14 cm uranium as multiplier, 23 cm TiF3 and 36 cm Fluental as moderator, 4 cm Fe as fast neutron filter, 1 mm Li as thermal neutron filter, 2.6 cm Bi as gamma ray filter, and Pb as collimator and reflector. It is also found that use of specific filters is important for removing the fast and thermal neutrons and gamma contamination. Moreover, an appropriate neutron source plays a key role in providing a proper epithermal flux.

In vitro incorporation of nonnatural amino acids into protein using tRNACys-derived opal, ochre, and amber suppressor tRNAs

PubMed Central

Gubbens, Jacob; Kim, Soo Jung; Yang, Zhongying; Johnson, Arthur E.; Skach, William R.

2010-01-01

Amber suppressor tRNAs are widely used to incorporate nonnatural amino acids into proteins to serve as probes of structure, environment, and function. The utility of this approach would be greatly enhanced if multiple probes could be simultaneously incorporated at different locations in the same protein without other modifications. Toward this end, we have developed amber, opal, and ochre suppressor tRNAs derived from Escherichia coli, and yeast tRNACys that incorporate a chemically modified cysteine residue with high selectivity at the cognate UAG, UGA, and UAA stop codons in an in vitro translation system. These synthetic tRNAs were aminoacylated in vitro, and the labile aminoacyl bond was stabilized by covalently attaching a fluorescent dye to the cysteine sulfhydryl group. Readthrough efficiency (amber > opal > ochre) was substantially improved by eRF1/eRF3 inhibition with an RNA aptamer, thus overcoming an intrinsic hierarchy in stop codon selection that limits UGA and UAA termination suppression in higher eukaryotic translation systems. This approach now allows concurrent incorporation of two different modified amino acids at amber and opal codons with a combined apparent readthrough efficiency of up to 25% when compared with the parent protein lacking a stop codon. As such, it significantly expands the possibilities for incorporating nonnative amino acids for protein structure/function studies. PMID:20581130

Molecular chirality and domain shapes in lipid monolayers on aqueous surfaces

NASA Astrophysics Data System (ADS)

Krüger, Peter; Lösche, Mathias

2000-11-01

The shapes of domain boundaries in the mesoscopic phase separation of phospholipids in aqueous surface monolayers are analyzed with particular attention to the influence of molecular chirality. We have calculated equilibrium shapes of such boundaries, and show that the concept of spontaneous curvature-derived from an effective pair potential between the chiral molecules-yields an adequate description of the contribution of chirality to the total energy of the system. For enantiomeric dipalmitoylphosphatidylcholine in pure monolayers, and in mixtures with impurities that adsorb preferentially at the (one-dimensional) boundary line between the isotropic and anisotropic fluid phases, such as cyanobiphenyl (5CB), a total energy term that includes line tension, electrostatic dipole-dipole interaction, and spontaneous curvature is sufficient to describe the shapes of well-separated domain boundaries in full detail. As soon as interdomain distances fall below the domain sizes upon compression of a monolayer, fluctuations take over in determining its detailed structural morphology. Using Minkowski measures for the well-studied dimyristoyl phosphatidic acid (DMPA)/cholesterol system, we show that calculations accounting for line tension, electrostatic repulsion, and molecular chirality yield boundary shapes that are of the same topology as the experimentally observed structures. At a fixed molecular area in the phase coexistence region, the DMPA/cholesterol system undergoes an exponential decay of the line tension λ with decreasing subphase temperature T.

Evolution of Skull and Mandible Shape in Cats (Carnivora: Felidae)

PubMed Central

Christiansen, Per

2008-01-01

The felid family consists of two major subgroups, the sabretoothed and the feline cats, to which all extant species belong, and are the most anatomically derived of all carnivores for predation on large prey with a precision killing bite. There has been much controversy and uncertainty about why the skulls and mandibles of sabretoothed and feline cats evolved to become so anatomically divergent, but previous models have focused on single characters and no unifying hypothesis of evolutionary shape changes has been formulated. Here I show that the shape of the skull and mandible in derived sabrecats occupy entirely different positions within overall morphospace from feline cats, and that the evolution of skull and mandible shape has followed very different paths in the two subgroups. When normalised for body-size differences, evolution of bite forces differ markedly in the two groups, and are much lower in derived sabrecats, and they show a significant relationship with size and cranial shape, whereas no such relationship is present in feline cats. Evolution of skull and mandible shape in modern cats has been governed by the need for uniform powerful biting irrespective of body size, whereas in sabrecats, shape evolution was governed by selective pressures for efficient predation with hypertrophied upper canines at high gape angles, and bite forces were secondary and became progressively weaker during sabrecat evolution. The current study emphasises combinations of new techniques for morphological shape analysis and biomechanical studies to formulate evolutionary hypotheses for difficult groups. PMID:18665225

Small RNAs Derived from the T-DNA of Agrobacterium rhizogenes in Hairy Roots of Phaseolus vulgaris

PubMed Central

Peláez, Pablo; Hernández-López, Alejandrina; Estrada-Navarrete, Georgina; Sanchez, Federico

2017-01-01

Agrobacterium rhizogenes is a pathogenic bacteria that causes hairy root disease by transferring bacterial DNA into the plant genome. It is an essential tool for industry and research due to its capacity to produce genetically modified roots and whole organisms. Here, we identified and characterized small RNAs generated from the transfer DNA (T-DNA) of A. rhizogenes in hairy roots of common bean (Phaseolus vulgaris). Distinct abundant A. rhizogenes T-DNA-derived small RNAs (ArT-sRNAs) belonging to several oncogenes were detected in hairy roots using high-throughput sequencing. The most abundant and diverse species of ArT-sRNAs were those of 21- and 22-nucleotides in length. Many T-DNA encoded genes constituted phasiRNA producing loci (PHAS loci). Interestingly, degradome analysis revealed that ArT-sRNAs potentially target genes of P. vulgaris. In addition, we detected low levels of ArT-sRNAs in the A. rhizogenes-induced calli generated at the wound site before hairy root emergence. These results suggest that RNA silencing targets several genes from T-DNA of A. rhizogenes in hairy roots of common bean. Therefore, the role of RNA silencing observed in this study has implications in our understanding and usage of this unique plant-bacteria interaction. PMID:28203245

Petal Thicknesses and Shape Transformations in Blooming Lilies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Portet, Thomas; Holmes, Peter N.; Bowden, Mark E.

2013-01-29

During blooming, flower petals undergo significant shape changes. For lilies, various different mechanisms responsible for the change have been suggested [1,2]. One is that cell growth along the edge of a petal, or, more generally, a tepal, drives a transition from a cup shape (within a bud) to a saddle shape (within a bloom). This mechanism has been previously considered for tepals modeled as shallow elliptical shells whose thickness from the center, t, falls off at least as fast as t = t0 (1 - x2/a2 - y2/b2 ) [1]. Here t0 is the maximum thickness of the shell, amore » and b are the semimajor and semiminoraxes, x and y are the coordinates along the longitudinal and lateral axes. By measuring tepal thicknesses from images collected by x-ray tomography of intact buds and by photography of microtomed buds, we find that this condition is indeed met for both Lilium casablanca and Lilium lancifolium. [1] Liang and Mahadevan. Growth, geometry, and mechanics of a blooming lily.« less

Use of chiral cell shape to ensure highly directional swimming in trypanosomes

PubMed Central

2017-01-01

Swimming cells typically move along a helical path or undergo longitudinal rotation as they swim, arising from chiral asymmetry in hydrodynamic drag or propulsion bending the swimming path into a helix. Helical paths are beneficial for some forms of chemotaxis, but why asymmetric shape is so prevalent when a symmetric shape would also allow highly directional swimming is unclear. Here, I analyse the swimming of the insect life cycle stages of two human parasites; Trypanosoma brucei and Leishmania mexicana. This showed quantitatively how chirality in T. brucei cell shape confers highly directional swimming. High speed videomicrographs showed that T. brucei, L. mexicana and a T. brucei RNAi morphology mutant have a range of shape asymmetries, from wild-type T. brucei (highly chiral) to L. mexicana (near-axial symmetry). The chiral cells underwent longitudinal rotation while swimming, with more rapid longitudinal rotation correlating with swimming path directionality. Simulation indicated hydrodynamic drag on the chiral cell shape caused rotation, and the predicted geometry of the resulting swimming path matched the directionality of the observed swimming paths. This simulation of swimming path geometry showed that highly chiral cell shape is a robust mechanism through which microscale swimmers can achieve highly directional swimming at low Reynolds number. It is insensitive to random variation in shape or propulsion (biological noise). Highly symmetric cell shape can give highly directional swimming but is at risk of giving futile circular swimming paths in the presence of biological noise. This suggests the chiral T. brucei cell shape (associated with the lateral attachment of the flagellum) may be an adaptation associated with the bloodstream-inhabiting lifestyle of this parasite for robust highly directional swimming. It also provides a plausible general explanation for why swimming cells tend to have strong asymmetries in cell shape or propulsion. PMID:28141804

Initial temperatures effect on the mixing efficiency and flow modes in T-shaped micromixer

NASA Astrophysics Data System (ADS)

Lobasov, A. S.; Shebeleva, A. A.

2017-09-01

Flow patterns and mixing of liquids with different initial temperatures in T-shaped micromixers are numerically investigated on the Reynolds number range from 1 to 250. The temperature of the one of mixing media was set equal to 20°C, while the temperature of the another mixing media was varied from 10°C to 50°C its effect on the flow structure and the mixing was studied. The dependences of the mixing efficiency and the pressure difference in this mixer on the difference in initial temperatures of miscible fluids and the Reynolds number were obtained. It was shown that the presence of a difference in initial temperatures of miscible fluids leads to a shift of flow regimes and the flow and mixing of two fluids with different initial temperatures can be considered as self-similar pattern with regard to the reduced Reynolds number.

Electric dipole-quadrupole hybridization induced enhancement of second-harmonic generation in T-shaped plasmonic heterodimers.

PubMed

Guo, Kai; Zhang, Yong-Liang; Qian, Cheng; Fung, Kin-Hung

2018-04-30

In this work, we demonstrate computationally that electric dipole-quadrupole hybridization (EDQH) could be utilized to enhance plasmonic SHG efficiency. To this end, we construct T-shaped plasmonic heterodimers consisting of a short and a long gold nanorod with finite element method simulation. By controlling the strength of capacitive coupling between two gold nanorods, we explore the effect of EDQH evolution on the SHG process, including the SHG efficiency enhancement, corresponding near-field distribution, and far-field radiation pattern. Simulation results demonstrate that EDQH could enhance the SHG efficiency by a factor >100 in comparison with that achieved by an isolated gold nanorod. Additionally, the far-field pattern of the SHG could be adjusted beyond the well-known quadrupolar distribution and confirms that EDQH plays an important role in the SHG process.

Diethylenetriaminepentaacetic acid-gadolinium (DTPA-Gd)-conjugated polysuccinimide derivatives as magnetic resonance imaging contrast agents.

PubMed

Lee, Ha Young; Jee, Hye Won; Seo, Sung Mi; Kwak, Byung Kook; Khang, Gilson; Cho, Sun Hang

2006-01-01

Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylamine as hydrophobic ligand, and DTPA-Gd as contrast agent. PSI was synthesized by the polycondensation polymerization of aspartic acid. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Critical micellization concentrations were determined using fluorescent probes (pyrene). Micelle size and shape were measured by electro-photometer light scattering (ELS) and atomic force microscopy (AFM). The formed micelle size ranged from 100 to 300 nm. The T1-weighted MR images of the phantom prepared with PSI-mPEG-C16-(DTPA-Gd) were obtained in a 3.0 T clinical MR imager, and the conjugates showed a great potential as MRI contrast agents.

SVBRDF-Invariant Shape and Reflectance Estimation from a Light-Field Camera.

PubMed

Wang, Ting-Chun; Chandraker, Manmohan; Efros, Alexei A; Ramamoorthi, Ravi

2018-03-01

Light-field cameras have recently emerged as a powerful tool for one-shot passive 3D shape capture. However, obtaining the shape of glossy objects like metals or plastics remains challenging, since standard Lambertian cues like photo-consistency cannot be easily applied. In this paper, we derive a spatially-varying (SV)BRDF-invariant theory for recovering 3D shape and reflectance from light-field cameras. Our key theoretical insight is a novel analysis of diffuse plus single-lobe SVBRDFs under a light-field setup. We show that, although direct shape recovery is not possible, an equation relating depths and normals can still be derived. Using this equation, we then propose using a polynomial (quadratic) shape prior to resolve the shape ambiguity. Once shape is estimated, we also recover the reflectance. We present extensive synthetic data on the entire MERL BRDF dataset, as well as a number of real examples to validate the theory, where we simultaneously recover shape and BRDFs from a single image taken with a Lytro Illum camera.

Creating a Minor in Applied Data Science: Case Western Reserve University Engages Business Leaders to Produce T-Shaped Professionals. A BHEF Case Study

ERIC Educational Resources Information Center

Business-Higher Education Forum, 2016

2016-01-01

This case study examines how Business-Higher Education Forum (BHEF) member Case Western Reserve University is integrating T-shaped skills into a minor in applied data science. Through the collaboration of its business and higher education members, BHEF launched the National Higher Education and Workforce Initiative to create new undergraduate…

Prediction of the shapes of deformed nuclei by the polyspheron theory.

PubMed

Pauling, L

1982-04-01

It is pointed out that some features of the shapes of (62) (154)Sm, (68) (166)Er, and (70) (176)Yb as reported by Cooper et al. [Cooper, T., Bertozzi, W., Heisenberg, J., Kowalski, S., Turchinetz, W., Williamson, C., Cardman, L., Fivozinsky, S., Lightbody, J., Jr., & Penner, S. (1976) Phys. Rev. C 13, 1083-1094] from electron-scattering experiments agree reasonably well with the description of these nuclei, derived from the values of the rotational energy levels, as consisting of a large spherical part (essentially (132)Sn) and a cap [Pauling, L. (1969) Proc. Natl. Acad. Sci. USA 64, 807-809; Pauling, L. & Robinson, A. B. (1975) Can. J. Phys. 53, 1953-1964].

Prediction of the shapes of deformed nuclei by the polyspheron theory

PubMed Central

Pauling, Linus

1982-01-01

It is pointed out that some features of the shapes of 62154Sm, 68166Er, and 70176Yb as reported by Cooper et al. [Cooper, T., Bertozzi, W., Heisenberg, J., Kowalski, S., Turchinetz, W., Williamson, C., Cardman, L., Fivozinsky, S., Lightbody, J., Jr., & Penner, S. (1976) Phys. Rev. C 13, 1083-1094] from electron-scattering experiments agree reasonably well with the description of these nuclei, derived from the values of the rotational energy levels, as consisting of a large spherical part (essentially 132Sn) and a cap [Pauling, L. (1969) Proc. Natl. Acad. Sci. USA 64, 807-809; Pauling, L. & Robinson, A. B. (1975) Can. J. Phys. 53, 1953-1964]. Images PMID:16593183

A Metric on Phylogenetic Tree Shapes.

PubMed

Colijn, C; Plazzotta, G

2018-01-01

The shapes of evolutionary trees are influenced by the nature of the evolutionary process but comparisons of trees from different processes are hindered by the challenge of completely describing tree shape. We present a full characterization of the shapes of rooted branching trees in a form that lends itself to natural tree comparisons. We use this characterization to define a metric, in the sense of a true distance function, on tree shapes. The metric distinguishes trees from random models known to produce different tree shapes. It separates trees derived from tropical versus USA influenza A sequences, which reflect the differing epidemiology of tropical and seasonal flu. We describe several metrics based on the same core characterization, and illustrate how to extend the metric to incorporate trees' branch lengths or other features such as overall imbalance. Our approach allows us to construct addition and multiplication on trees, and to create a convex metric on tree shapes which formally allows computation of average tree shapes. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

DNA unwinding by ring-shaped T4 helicase gp41 is hindered by tension on the occluded strand.

PubMed

Ribeck, Noah; Saleh, Omar A

2013-01-01

The replicative helicase for bacteriophage T4 is gp41, which is a ring-shaped hexameric motor protein that achieves unwinding of dsDNA by translocating along one strand of ssDNA while forcing the opposite strand to the outside of the ring. While much study has been dedicated to the mechanism of binding and translocation along the ssDNA strand encircled by ring-shaped helicases, relatively little is known about the nature of the interaction with the opposite, 'occluded' strand. Here, we investigate the interplay between the bacteriophage T4 helicase gp41 and the ss/dsDNA fork by measuring, at the single-molecule level, DNA unwinding events on stretched DNA tethers in multiple geometries. We find that gp41 activity is significantly dependent on the geometry and tension of the occluded strand, suggesting an interaction between gp41 and the occluded strand that stimulates the helicase. However, the geometry dependence of gp41 activity is the opposite of that found previously for the E. coli hexameric helicase DnaB. Namely, tension applied between the occluded strand and dsDNA stem inhibits unwinding activity by gp41, while tension pulling apart the two ssDNA tails does not hinder its activity. This implies a distinct variation in helicase-occluded strand interactions among superfamily IV helicases, and we propose a speculative model for this interaction that is consistent with both the data presented here on gp41 and the data that had been previously reported for DnaB.

Shaping asteroid models using genetic evolution (SAGE)

NASA Astrophysics Data System (ADS)

Bartczak, P.; Dudziński, G.

2018-02-01

In this work, we present SAGE (shaping asteroid models using genetic evolution), an asteroid modelling algorithm based solely on photometric lightcurve data. It produces non-convex shapes, orientations of the rotation axes and rotational periods of asteroids. The main concept behind a genetic evolution algorithm is to produce random populations of shapes and spin-axis orientations by mutating a seed shape and iterating the process until it converges to a stable global minimum. We tested SAGE on five artificial shapes. We also modelled asteroids 433 Eros and 9 Metis, since ground truth observations for them exist, allowing us to validate the models. We compared the derived shape of Eros with the NEAR Shoemaker model and that of Metis with adaptive optics and stellar occultation observations since other models from various inversion methods were available for Metis.

Constraints on Martian Aerosol Particles Using MGS/TES and HST Data: Shapes

NASA Astrophysics Data System (ADS)

Wolff, M. J.; Clancy, R. T.; Pitman, K. M.; Bell, J. F.; James, P. B.

2001-12-01

In order to constrain the shape of water ice and dust aerosols, we have combined a numerical approach for axisymmetric particle shapes, i.e., cylinders, disks, spheroids (Waterman's T-Matrix approach as improved by Mishchenko and collaborators; cf., Mishchenko et al. 1997, JGR, 102, D14, 16,831), with a multiple-scattering radiative transfer algorithm. We utilize a two-stage iterative process. First, we empirically derive a scattering phase function for each aerosol component from radiative transfer models of Mars Global Surveyor Thermal Emission Spectrometer Emission Phase Function (EPF) sequences. Next, we perform a series of scattering calculations, adjusting our parameters to arrive at a ``best-fit'' theoretical phase function. It is important to note that in addition to randomly-oriented particles, we explicitly consider the possibility of (partially) aligned aerosol particles as well. Thus far, we have been analyzing the three empirically-derived presented by Clancy et al. (this meeting): dust, Type I ice particles (effective radii ~ 1-2 microns), and Type II ice particles (effective radii ~ 3-4 microns). We find that the ``dust'' phase function is best fit by randomly-oriented cylinders with an axial ratio (D/L = diameter-to-length) of either 2.3 or 0.6. Similarly, the shape of the Type II ice curve is reasonably reproduced by randomly-oriented spheroids with an axial ratio of either 0.7 or 1.4. However, neither of the two shapes (nor that of spheres or randomly-oriented hexagonal prisms) can reproduce the phase function derived for the Type I ice. This led to the direct consideration of oriented or aligned particles. which, at least qualitatively, have the ability to account for the phase function shapes for both Type I and II ice particles. The difference between these two phase functions may represent the degree of alignment, with the Type II particles being much less-aligned. The calculations for partially aligned particles is quite numerically intensive

Bone marrow-derived cultured mast cells and peritoneal mast cells as targets of a growth activity secreted by BALB/3T3 fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jozaki, K.; Kuriu, A.; Hirota, S.

1991-03-01

When fibroblast cell lines were cultured in contact with bone marrow-derived cultured mast cells (CMC), both NIH/3T3 and BALB/3T3 cell lines supported the proliferation of CMC. In contrast, when contact between fibroblasts and CMC was prohibited by Biopore membranes or soft agar, only BALB/3T3 fibroblasts supported CMC proliferation, suggesting that BALB/3T3 but not NIH/3T3 cells secreted a significant amount of a mast cell growth activity. Moreover, the BALB/3T3-derived growth activity induced the incorporation of (3H)thymidine by CMC and the clonal growth of peritoneal mast cells in methylcellulose. The mast cell growth activity appeared to be different from interleukin 3 (IL-3)more » and interleukin 4 (IL-4), because mRNAs for these interleukins were not detectable in BALB/3T3 fibroblasts. Although mast cells are genetically deficient in tissues of W/Wv mice, CMC did develop when bone marrow cells of W/Wv mice were cultured with pokeweed mitogen-stimulated spleen cell-conditioned medium. Because BALB/3T3 fibroblast-conditioned medium (BALB-FCM) did not induce the incorporation of (3H)thymidine by W/Wv CMC, the growth activity in BALB-FCM appeared to be a ligand for the receptor encoded by the W (c-kit) locus. Because CMC and peritoneal mast cells are obtained as homogeneous suspensions rather easily, these cells may be potentially useful as targets for the fibroblast-derived mast cell growth activity.« less

Analytical study on the thermal performance of a partially wet constructal T-shaped fin

NASA Astrophysics Data System (ADS)

Hazarika, Saheera Azmi; Zeeshan, Mohd; Bhanja, Dipankar; Nath, Sujit

2017-07-01

The present paper addresses the thermal analysis of a T-shaped fin under partially wet condition by adopting a cubic variation of the humidity ratio of saturated air with the corresponding fin surface temperature. The point separating the dry and wet parts may lie either in the flange or stem part of the fin and so, two different cases having different governing equations and boundary conditions are analyzed in this paper. Since the governing equations are highly non-linear, they are solved by using an analytical technique called the Differential Transform Method and subsequently, the dry fin length, temperature distribution and fin performances are evaluated and analyzed for a wide range of the various psychometric, geometric and thermo-physical parameters. Finally, it can be highlighted that relative humidity has a pronounced effect on the performance parameters when the fin surface is partially wet whereas this effect is marginally small for fully wet surface.

Digital holographic microscopy applied to measurement of a flow in a T-shaped micromixer

NASA Astrophysics Data System (ADS)

Ooms, T. A.; Lindken, R.; Westerweel, J.

2009-12-01

In this paper, we describe measurements of a three-dimensional (3D) flow in a T-shaped micromixer by means of digital holographic microscopy. Imaging tracer particles in a microscopic flow with conventional microscopy is accompanied by a small depth-of-field, which hinders true volumetric flow measurements. In holographic microscopy, the depth of the measurement domain does not have this limitation because any desired image plane can be reconstructed after recording. Our digital holographic microscope (DHM) consists of a conventional in-line recording system with an added magnifying optical element. The measured flow velocity and the calculated vorticity illustrate four streamwise vortices in the micromixer outflow channel. Because the investigated flow is stationary and strongly 3D, the DHM performance (i.e. accuracy and resolution) can be precisely investigated. The obtained Dynamic spatial range and Dynamic velocity range are larger than 20 and 30, respectively. High-speed multiple-frame measurements illustrate the capability to simultaneously track about 80 particles in a volumetric measurement domain.

Role of latent membrane protein 1 in chronic active Epstein–Barr virus infection-derived T/NK-cell proliferation

PubMed Central

Ito, Takuto; Kawazu, Hidetaka; Murata, Takayuki; Iwata, Seiko; Arakawa, Saki; Sato, Yoshitaka; Kuzushima, Kiyotaka; Goshima, Fumi; Kimura, Hiroshi

2014-01-01

Epstein–Barr virus (EBV) predominantly infects B cells and causes B-cell lymphomas, such as Burkitt lymphoma and Hodgkin lymphoma. However, it also infects other types of cells, including T and natural killer (NK) cells, and causes disorders, such as chronic active EBV infection (CAEBV) and T/NK-cell lymphoma. The CAEBV is a lymphoproliferative disease with poor prognosis, where EBV-positive T or NK cells grow rapidly, although the molecular mechanisms that cause the cell expansion still remain to be elucidated. EBV-encoded latent membrane protein 1 (LMP1) is an oncogene that can transform some cell types, such as B cells and mouse fibroblasts, and thus may stimulate cell proliferation in CAEBV. Here, we examined the effect of LMP1 on EBV-negative cells using the cells conditionally expressing LMP1, and on CAEBV-derived EBV-positive cells by inhibiting the function of LMP1 using a dominant negative form of LMP1. We demonstrated that LMP1 was responsible for the increased cell proliferation in the cell lines derived from CAEBV, while LMP1 did not give any proliferative advantage to the EBV-negative cell line. PMID:24799376

High-Temperature Shape Memory Behavior of Semicrystalline Polyamide Thermosets

PubMed Central

2018-01-01

We have explored semicrystalline poly(decamethylene terephthalamide) (PA 10T) based thermosets as single-component high-temperature (>200 °C) shape memory polymers (SMPs). The PA 10T thermosets were prepared from reactive thermoplastic precursors. Reactive phenylethynyl (PE) functionalities were either attached at the chain termini or placed as side groups along the polymer main chain. The shape fixation and recovery performance of the thermoset films were investigated using a rheometer in torsion mode. By controlling the Mn of the reactive oligomers, or the PE concentration of the PE side-group functionalized copolyamides, we were able to design dual-shape memory PA 10T thermosets with a broad recovery temperature range of 227–285 °C. The thermosets based on the 1000 g mol–1 reactive PE precursor and the copolyamide with 15 mol % PE side groups show the highest fixation rate (99%) and recovery rate (≥90%). High temperature triple-shape memory behavior can be achieved as well when we use the melt transition (Tm ≥ 200 °C) and the glass transition (Tg = ∼125 °C) as the two switches. The recovery rate of the two recovery steps are highly dependent on the crystallinity of the thermosets and vary within a wide range of 74%–139% and 40–82% for the two steps, respectively. Reversible shape memory events could also be demonstrated when we perform a forward and backward deformation in a triple shape memory cycle. We also studied the angular recovery velocity as a function of temperature, which provides a thermokinematic picture of the shape recovery process and helps to program for desired shape memory behavior. PMID:29742899

Shape optimization using a NURBS-based interface-enriched generalized FEM

DOE PAGES

Najafi, Ahmad R.; Safdari, Masoud; Tortorelli, Daniel A.; ...

2016-11-26

This study presents a gradient-based shape optimization over a fixed mesh using a non-uniform rational B-splines-based interface-enriched generalized finite element method, applicable to multi-material structures. In the proposed method, non-uniform rational B-splines are used to parameterize the design geometry precisely and compactly by a small number of design variables. An analytical shape sensitivity analysis is developed to compute derivatives of the objective and constraint functions with respect to the design variables. Subtle but important new terms involve the sensitivity of shape functions and their spatial derivatives. As a result, verification and illustrative problems are solved to demonstrate the precision andmore » capability of the method.« less

Combining color and shape information for illumination-viewpoint invariant object recognition.

PubMed

Diplaros, Aristeidis; Gevers, Theo; Patras, Ioannis

2006-01-01

In this paper, we propose a new scheme that merges color- and shape-invariant information for object recognition. To obtain robustness against photometric changes, color-invariant derivatives are computed first. Color invariance is an important aspect of any object recognition scheme, as color changes considerably with the variation in illumination, object pose, and camera viewpoint. These color invariant derivatives are then used to obtain similarity invariant shape descriptors. Shape invariance is equally important as, under a change in camera viewpoint and object pose, the shape of a rigid object undergoes a perspective projection on the image plane. Then, the color and shape invariants are combined in a multidimensional color-shape context which is subsequently used as an index. As the indexing scheme makes use of a color-shape invariant context, it provides a high-discriminative information cue robust against varying imaging conditions. The matching function of the color-shape context allows for fast recognition, even in the presence of object occlusion and cluttering. From the experimental results, it is shown that the method recognizes rigid objects with high accuracy in 3-D complex scenes and is robust against changing illumination, camera viewpoint, object pose, and noise.

The effect of ice crystal shape on aircraft contrails

NASA Astrophysics Data System (ADS)

Meza Castillo, Omar E.

ice crystal number, N(t), is not significant compared with the level of uncertainty. In young contrails, the difference between spherical and non-spherical shapes in N(t) is less than 7% for relatively large ice particles and 23% for relatively small ice particles. The ice mass, M(t), is not significantly affected by the crystal shapes, with less than 8% difference. However, the ice surface area, S(t), is the ice metric more sensitive to crystal shape, with a maximum difference of 68%. It increases at late time, though it is mainly governed by geometrical rather than dynamical effects. The small sensitivity to shape effects in the ice contrail metrics when radiation is not included suggests that the spherical shape will provide a reasonable representation for all shapes found in the in-situ studies. The radiation is included at late time, when the lasting effects of contrails are more critical. The inclusion of coupled radiation increases the level of dispersion in the results and hence increases slightly the differences due to shape effects. The small difference is also observed in the infrared heating rates of contrails.

Human action classification using procrustes shape theory

NASA Astrophysics Data System (ADS)

Cho, Wanhyun; Kim, Sangkyoon; Park, Soonyoung; Lee, Myungeun

2015-02-01

In this paper, we propose new method that can classify a human action using Procrustes shape theory. First, we extract a pre-shape configuration vector of landmarks from each frame of an image sequence representing an arbitrary human action, and then we have derived the Procrustes fit vector for pre-shape configuration vector. Second, we extract a set of pre-shape vectors from tanning sample stored at database, and we compute a Procrustes mean shape vector for these preshape vectors. Third, we extract a sequence of the pre-shape vectors from input video, and we project this sequence of pre-shape vectors on the tangent space with respect to the pole taking as a sequence of mean shape vectors corresponding with a target video. And we calculate the Procrustes distance between two sequences of the projection pre-shape vectors on the tangent space and the mean shape vectors. Finally, we classify the input video into the human action class with minimum Procrustes distance. We assess a performance of the proposed method using one public dataset, namely Weizmann human action dataset. Experimental results reveal that the proposed method performs very good on this dataset.

Total Bregman Divergence and its Applications to Shape Retrieval.

PubMed

Liu, Meizhu; Vemuri, Baba C; Amari, Shun-Ichi; Nielsen, Frank

2010-01-01

Shape database search is ubiquitous in the world of biometric systems, CAD systems etc. Shape data in these domains is experiencing an explosive growth and usually requires search of whole shape databases to retrieve the best matches with accuracy and efficiency for a variety of tasks. In this paper, we present a novel divergence measure between any two given points in [Formula: see text] or two distribution functions. This divergence measures the orthogonal distance between the tangent to the convex function (used in the definition of the divergence) at one of its input arguments and its second argument. This is in contrast to the ordinate distance taken in the usual definition of the Bregman class of divergences [4]. We use this orthogonal distance to redefine the Bregman class of divergences and develop a new theory for estimating the center of a set of vectors as well as probability distribution functions. The new class of divergences are dubbed the total Bregman divergence (TBD). We present the l 1 -norm based TBD center that is dubbed the t-center which is then used as a cluster center of a class of shapes The t-center is weighted mean and this weight is small for noise and outliers. We present a shape retrieval scheme using TBD and the t-center for representing the classes of shapes from the MPEG-7 database and compare the results with other state-of-the-art methods in literature.

Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision aid: single biomarker re-derivation and external validation in three cohorts

PubMed Central

Body, Richard; Sperrin, Matthew; Lewis, Philip S; Burrows, Gillian; Carley, Simon; McDowell, Garry; Buchan, Iain; Greaves, Kim; Mackway-Jones, Kevin

2017-01-01

Background The original Manchester Acute Coronary Syndromes model (MACS) ‘rules in’ and ‘rules out’ acute coronary syndromes (ACS) using high sensitivity cardiac troponin T (hs-cTnT) and heart-type fatty acid binding protein (H-FABP) measured at admission. The latter is not always available. We aimed to refine and validate MACS as Troponin-only Manchester Acute Coronary Syndromes (T-MACS), cutting down the biomarkers to just hs-cTnT. Methods We present secondary analyses from four prospective diagnostic cohort studies including patients presenting to the ED with suspected ACS. Data were collected and hs-cTnT measured on arrival. The primary outcome was ACS, defined as prevalent acute myocardial infarction (AMI) or incident death, AMI or coronary revascularisation within 30 days. T-MACS was built in one cohort (derivation set) and validated in three external cohorts (validation set). Results At the ‘rule out’ threshold, in the derivation set (n=703), T-MACS had 99.3% (95% CI 97.3% to 99.9%) negative predictive value (NPV) and 98.7% (95.3%–99.8%) sensitivity for ACS, ‘ruling out’ 37.7% patients (specificity 47.6%, positive predictive value (PPV) 34.0%). In the validation set (n=1459), T-MACS had 99.3% (98.3%–99.8%) NPV and 98.1% (95.2%–99.5%) sensitivity, ‘ruling out’ 40.4% (n=590) patients (specificity 47.0%, PPV 23.9%). T-MACS would ‘rule in’ 10.1% and 4.7% patients in the respective sets, of which 100.0% and 91.3% had ACS. C-statistics for the original and refined rules were similar (T-MACS 0.91 vs MACS 0.90 on validation). Conclusions T-MACS could ‘rule out’ ACS in 40% of patients, while ‘ruling in’ 5% at highest risk using a single hs-cTnT measurement on arrival. As a clinical decision aid, T-MACS could therefore help to conserve healthcare resources. PMID:27565197

Study of the natural occurrence of T-2 and HT-2 toxins and their glucosyl derivatives from field barley to malt by high-resolution Orbitrap mass spectrometry

USDA-ARS?s Scientific Manuscript database

This paper reports a new method for the determination of T-2 and HT-2 toxins and their glucosylated derivatives in cereals, and some survey data aimed at obtaining more comprehensive information on the co-occurrence of T-2 and HT-2 toxins and their glucosylated derivatives in naturally contaminated ...

Ginzburg-Landau Theory for Flux Phase and Superconductivity in t-J Model

NASA Astrophysics Data System (ADS)

Kuboki, Kazuhiro

2018-02-01

Ginzburg-Landau (GL) equations and GL free energy for flux phase and superconductivity are derived microscopically from the t-J model on a square lattice. Order parameter (OP) for the flux phase has direct coupling to a magnetic field, in contrast to the superconducting OP which has minimal coupling to a vector potential. Therefore, when the flux phase OP has unidirectional spatial variation, staggered currents would flow in a perpendicular direction. The derived GL theory can be used for various problems in high-Tc cuprate superconductors, e.g., states near a surface or impurities, and the effect of an external magnetic field. Since the GL theory derived microscopically directly reflects the electronic structure of the system, e.g., the shape of the Fermi surface that changes with doping, it can provide more useful information than that from phenomenological GL theories.

γδ T Cells Shape Preimmune Peripheral B Cell Populations.

PubMed

Huang, Yafei; Getahun, Andrew; Heiser, Ryan A; Detanico, Thiago O; Aviszus, Katja; Kirchenbaum, Greg A; Casper, Tamara L; Huang, Chunjian; Aydintug, M Kemal; Carding, Simon R; Ikuta, Koichi; Huang, Hua; Wysocki, Lawrence J; Cambier, John C; O'Brien, Rebecca L; Born, Willi K

2016-01-01

We previously reported that selective ablation of certain γδ T cell subsets, rather than removal of all γδ T cells, strongly affects serum Ab levels in nonimmunized mice. This type of manipulation also changed T cells, including residual γδ T cells, revealing some interdependence of γδ T cell populations. For example, in mice lacking Vγ4(+) and Vγ6(+) γδ T cells (B6.TCR-Vγ4(-/-)/6(-/-)), we observed expanded Vγ1(+) cells, which changed in composition and activation and produced more IL-4 upon stimulation in vitro, increased IL-4 production by αβ T cells as well as spontaneous germinal center formation in the spleen, and elevated serum Ig and autoantibodies. We therefore examined B cell populations in this and other γδ-deficient mouse strains. Whereas immature bone marrow B cells remained largely unchanged, peripheral B cells underwent several changes. Specifically, transitional and mature B cells in the spleen of B6.TCR-Vγ4(-/-)/6(-/-) mice and other peripheral B cell populations were diminished, most of all splenic marginal zone (MZ) B cells. However, relative frequencies and absolute numbers of Ab-producing cells, as well as serum levels of Abs, IL-4, and BAFF, were increased. Cell transfers confirmed that these changes are directly dependent on the altered γδ T cells in this strain and on their enhanced potential of producing IL-4. Further evidence suggests the possibility of direct interactions between γδ T cells and B cells in the splenic MZ. Taken together, these data demonstrate the capability of γδ T cells of modulating size and productivity of preimmune peripheral B cell populations. Copyright © 2015 by The American Association of Immunologists, Inc.

Reconstructing liver shape and position from MR image slices using an active shape model

NASA Astrophysics Data System (ADS)

Fenchel, Matthias; Thesen, Stefan; Schilling, Andreas

2008-03-01

We present an algorithm for fully automatic reconstruction of 3D position, orientation and shape of the human liver from a sparsely covering set of n 2D MR slice images. Reconstructing the shape of an organ from slice images can be used for scan planning, for surgical planning or other purposes where 3D anatomical knowledge has to be inferred from sparse slices. The algorithm is based on adapting an active shape model of the liver surface to a given set of slice images. The active shape model is created from a training set of liver segmentations from a group of volunteers. The training set is set up with semi-manual segmentations of T1-weighted volumetric MR images. Searching for the optimal shape model that best fits to the image data is done by maximizing a similarity measure based on local appearance at the surface. Two different algorithms for the active shape model search are proposed and compared: both algorithms seek to maximize the a-posteriori probability of the grey level appearance around the surface while constraining the surface to the space of valid shapes. The first algorithm works by using grey value profile statistics in normal direction. The second algorithm uses average and variance images to calculate the local surface appearance on the fly. Both algorithms are validated by fitting the active shape model to abdominal 2D slice images and comparing the shapes, which have been reconstructed, to the manual segmentations and to the results of active shape model searches from 3D image data. The results turn out to be promising and competitive to active shape model segmentations from 3D data.

Giant dipole resonance and shape transitions in hot and rotating 88Mo

NASA Astrophysics Data System (ADS)

Rhine Kumar, A. K.; Arumugam, P.; Dang, N. Dinh; Mazumdar, I.

2017-08-01

The giant dipole resonance (GDR) observables are calculated within the thermal shape fluctuation model by considering the probability distributions of different angular momentum (I ) and temperature (T ) values estimated recently in the deexcitation process of the compound nucleus 88Mo. These results are found to be very similar to the results obtained with the average T (Tave) and average I (Iave) corresponding to those distributions. The shape transitions in 88Mo at different T and I are also studied through the free energy surfaces calculated within the microscopic-macroscopic approach. The deformation of 88Mo is found to increase considerably with T and I , leading to the Jacobi shape transition at I ˜50 ℏ . The combined effect of increasing deformation, larger fluctuations at higher T , and larger Coriolis splitting of GDR components at higher I , leads to a rapid increase in the GDR width.

Role of latent membrane protein 1 in chronic active Epstein-Barr virus infection-derived T/NK-cell proliferation.

PubMed

Ito, Takuto; Kawazu, Hidetaka; Murata, Takayuki; Iwata, Seiko; Arakawa, Saki; Sato, Yoshitaka; Kuzushima, Kiyotaka; Goshima, Fumi; Kimura, Hiroshi

2014-08-01

Epstein-Barr virus (EBV) predominantly infects B cells and causes B-cell lymphomas, such as Burkitt lymphoma and Hodgkin lymphoma. However, it also infects other types of cells, including T and natural killer (NK) cells, and causes disorders, such as chronic active EBV infection (CAEBV) and T/NK-cell lymphoma. The CAEBV is a lymphoproliferative disease with poor prognosis, where EBV-positive T or NK cells grow rapidly, although the molecular mechanisms that cause the cell expansion still remain to be elucidated. EBV-encoded latent membrane protein 1 (LMP1) is an oncogene that can transform some cell types, such as B cells and mouse fibroblasts, and thus may stimulate cell proliferation in CAEBV. Here, we examined the effect of LMP1 on EBV-negative cells using the cells conditionally expressing LMP1, and on CAEBV-derived EBV-positive cells by inhibiting the function of LMP1 using a dominant negative form of LMP1. We demonstrated that LMP1 was responsible for the increased cell proliferation in the cell lines derived from CAEBV, while LMP1 did not give any proliferative advantage to the EBV-negative cell line. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Mesenchymal stromal cells derived from cervical cancer produce high amounts of adenosine to suppress cytotoxic T lymphocyte functions.

PubMed

de Lourdes Mora-García, María; García-Rocha, Rosario; Morales-Ramírez, Omar; Montesinos, Juan José; Weiss-Steider, Benny; Hernández-Montes, Jorge; Ávila-Ibarra, Luis Roberto; Don-López, Christian Azucena; Velasco-Velázquez, Marco Antonio; Gutiérrez-Serrano, Vianey; Monroy-García, Alberto

2016-10-26

In recent years, immunomodulatory mechanisms of mesenchymal stem/stromal cells (MSCs) from bone marrow and other "classic" sources have been described. However, the phenotypic and functional properties of tumor MSCs are poorly understood. The aim of this study was to analyze the immunosuppressive capacity of cervical cancer-derived MSCs (CeCa-MSCs) on effector T lymphocytes through the purinergic pathway. We determined the expression and functional activity of the membrane-associated ectonucleotidases CD39 and CD73 on CeCa-MSCs and normal cervical tissue-derived MSCs (NCx-MSCs). We also analyzed their immunosuppressive capacity to decrease proliferation, activation and effector cytotoxic T (CD8+) lymphocyte function through the generation of adenosine (Ado). We detected that CeCa-MSCs express higher levels of CD39 and CD73 ectonucleotidases in cell membranes compared to NCx-MSCs, and that this feature was associated with the ability to strongly suppress the proliferation, activation and effector functions of cytotoxic T-cells through the generation of large amounts of Ado from the hydrolysis of ATP, ADP and AMP nucleotides. This study suggests that CeCa-MSCs play an important role in the suppression of the anti-tumor immune response in CeCa through the purinergic pathway.

Complete TCRα gene locus control region activity in T cells derived in vitro from embryonic stem cells

PubMed Central

Lahiji, Armin; Kučerová-Levisohn, Martina; Lovett, Jordana; Holmes, Roxanne; Zúñiga-Pflücker, Juan Carlos; Ortiz, Benjamin D.

2013-01-01

Locus Control Regions (LCR) are cis-acting gene regulatory elements with the unique, integration site-independent ability to transfer the characteristics of their locus-of-origin’s gene expression pattern to a linked transgene in mice. LCR activities have been discovered in numerous T cell lineage expressed gene loci. These elements can be adapted to the design of stem cell gene therapy vectors that direct robust therapeutic gene expression to the T cell progeny of engineered stem cells. Currently, transgenic mice provide the only experimental approach that wholly supports all the critical aspects of LCR activity. Herein we report manifestation of all key features of mouse T cell receptor (TCR)-α gene LCR function in T cells derived in vitro from mouse embryonic stem cells (ESC). High level, copy number-related TCRα LCR-linked reporter gene expression levels are cell type-restricted in this system, and upregulated during the expected stage transition of T cell development. We further report that de novo introduction of TCRα LCR linked transgenes into existing T cell lines yields incomplete LCR activity. Together, these data indicate that establishing full TCRα LCR activity requires critical molecular events occurring prior to final T-lineage determination. This study additionally validates a novel, tractable and more rapid approach for the study of LCR activity in T cells, and its translation to therapeutic genetic engineering. PMID:23720809

Communication: Ion mobility of the radical cation dimers: (Naphthalene)2+• and naphthalene+•-benzene: Evidence for stacked sandwich and T-shape structures

NASA Astrophysics Data System (ADS)

Platt, Sean P.; Attah, Isaac K.; Aziz, Saadullah; El-Shall, M. Samy

2015-05-01

Dimer radical cations of aromatic and polycyclic aromatic molecules are good model systems for a fundamental understanding of photoconductivity and ferromagnetism in organic materials which depend on the degree of charge delocalization. The structures of the dimer radical cations are difficult to determine theoretically since the potential energy surface is often very flat with multiple shallow minima representing two major classes of isomers adopting the stacked parallel or the T-shape structure. We present experimental results, based on mass-selected ion mobility measurements, on the gas phase structures of the naphthalene+ṡ ṡ naphthalene homodimer and the naphthalene+ṡ ṡ benzene heterodimer radical cations at different temperatures. Ion mobility studies reveal a persistence of the stacked parallel structure of the naphthalene+ṡ ṡ naphthalene homodimer in the temperature range 230-300 K. On the other hand, the results reveal that the naphthalene+ṡ ṡ benzene heterodimer is able to exhibit both the stacked parallel and T-shape structural isomers depending on the experimental conditions. Exploitation of the unique structural motifs among charged homo- and heteroaromatic-aromatic interactions may lead to new opportunities for molecular design and recognition involving charged aromatic systems.

Maritime patrol aircraft engine study, General Electric Derivative Engines. Volume III. Appendix B: performance data, TF 34/T7 study AL turboprop. Final report October 1978-April 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirschkron, R.; Davis, R.H.; Warren, R.E.

1979-04-30

This study developed data on General Electric common core derivative engines for use in Maritime Patrol Aircraft (MPA) concept formulation studies. The study included the screening of potential General Electric turbofan and turboprop/turboshaft engines and the preparation of technical and planning information on three of the most promising engine candidates. Screening of General Electric derivative candidates was performed utilizing an analytical MPA model using synthesized mission profiles to rank the candidates in terms of fuel consumption, weight, cost and complexity. The three turboprop engines selected for further study were as follows: TF34 growth derivative version with boost and new LPTmore » (TF34/T7 Study A1), F404 derivative with booster stages and new LPT (F404/T1 Study A1), and GE27 scaled and boosted study engine (GE27/T3 Study A1). Volume I summarizes the screening analysis and contains technical, planning, installation, cost and development data for the three selected turboprop engines. Volumes II, III and IV of this report contain the detailed performance data estimates for the GE27/T3 Study A1, TF34/T7 Study A1 and F404/T1 Study A1 turboprop engines, respectively.« less

Female pelvic synthetic CT generation based on joint intensity and shape analysis

NASA Astrophysics Data System (ADS)

Liu, Lianli; Jolly, Shruti; Cao, Yue; Vineberg, Karen; Fessler, Jeffrey A.; Balter, James M.

2017-04-01

Using MRI for radiotherapy treatment planning and image guidance is appealing as it provides superior soft tissue information over CT scans and avoids possible systematic errors introduced by aligning MR to CT images. This study presents a method that generates Synthetic CT (MRCT) volumes by performing probabilistic tissue classification of voxels from MRI data using a single imaging sequence (T1 Dixon). The intensity overlap between different tissues on MR images, a major challenge for voxel-based MRCT generation methods, is addressed by adding bone shape information to an intensity-based classification scheme. A simple pelvic bone shape model, built from principal component analysis of pelvis shape from 30 CT image volumes, is fitted to the MR volumes. The shape model generates a rough bone mask that excludes air and covers bone along with some surrounding soft tissues. Air regions are identified and masked out from the tissue classification process by intensity thresholding outside the bone mask. A regularization term is added to the fuzzy c-means classification scheme that constrains voxels outside the bone mask from being assigned memberships in the bone class. MRCT image volumes are generated by multiplying the probability of each voxel being represented in each class with assigned attenuation values of the corresponding class and summing the result across all classes. The MRCT images presented intensity distributions similar to CT images with a mean absolute error of 13.7 HU for muscle, 15.9 HU for fat, 49.1 HU for intra-pelvic soft tissues, 129.1 HU for marrow and 274.4 HU for bony tissues across 9 patients. Volumetric modulated arc therapy (VMAT) plans were optimized using MRCT-derived electron densities, and doses were recalculated using corresponding CT-derived density grids. Dose differences to planning target volumes were small with mean/standard deviation of 0.21/0.42 Gy for D0.5cc and 0.29/0.33 Gy for D99%. The results demonstrate the accuracy of the

A novel design of beam shaping assembly to use D-T neutron generator for BNCT.

PubMed

Kasesaz, Yaser; Karimi, Marjan

2016-12-01

In order to use 14.1MeV neutrons produced by d-T neutron generators, two special and novel Beam Shaping Assemblies (BSA), including multi-layer and hexagonal lattice have been suggested and the effect of them has been investigated by MCNP4C Monte Carlo code. The results show that the proposed BSA can provide the qualified epithermal neutron beam for BNCT. The final epithermal neutron flux is about 6e9 n/cm2.s. The final proposed BSA has some different advantages: 1) it consists of usual and well-known materials (Pb, Al, Fluental and Cd); 2) it has a simple geometry; 3) it does not need any additional gamma filter; 4) it can provide high flux of epithermal neutrons. As this type of neutron source is under development in the world, it seems that they can be used clinically in a hospital considering the proposed BSA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Constraining Cometary Crystal Shapes from IR Spectral Features

NASA Technical Reports Server (NTRS)

Wooden, Diane H.; Lindsay, Sean; Harker, David E.; Kelley, Michael S. P.; Woodward, Charles E.; Murphy, James Richard

2013-01-01

A major challenge in deriving the silicate mineralogy of comets is ascertaining how the anisotropic nature of forsterite crystals affects the spectral features' wavelength, relative intensity, and asymmetry. Forsterite features are identified in cometary comae near 10, 11.05-11.2, 16, 19, 23.5, 27.5 and 33 microns [1-10], so accurate models for forsterite's absorption efficiency (Qabs) are a primary requirement to compute IR spectral energy distributions (SEDs, lambdaF lambda vs. lambda) and constrain the silicate mineralogy of comets. Forsterite is an anisotropic crystal, with three crystallographic axes with distinct indices of refraction for the a-, b-, and c-axis. The shape of a forsterite crystal significantly affects its spectral features [13-16]. We need models that account for crystal shape. The IR absorption efficiencies of forsterite are computed using the discrete dipole approximation (DDA) code DDSCAT [11,12]. Starting from a fiducial crystal shape of a cube, we systematically elongate/reduce one of the crystallographic axes. Also, we elongate/reduce one axis while the lengths of the other two axes are slightly asymmetric (0.8:1.2). The most significant grain shape characteristic that affects the crystalline spectral features is the relative lengths of the crystallographic axes. The second significant grain shape characteristic is breaking the symmetry of all three axes [17]. Synthetic spectral energy distributions using seven crystal shape classes [17] are fit to the observed SED of comet C/1995 O1 (Hale-Bopp). The Hale-Bopp crystalline residual better matches equant, b-platelets, c-platelets, and b-columns spectral shape classes, while a-platelets, a-columns and c-columns worsen the spectral fits. Forsterite condensation and partial evaporation experiments demonstrate that environmental temperature and grain shape are connected [18-20]. Thus, grain shape is a potential probe for protoplanetary disk temperatures where the cometary crystalline

Hepatocyte-derived exosomes promote T follicular regulatory cell expansion during hepatitis C virus infection.

PubMed

Cobb, Dustin A; Kim, Ok-Kyung; Golden-Mason, Lucy; Rosen, Hugo R; Hahn, Young S

2018-01-01

Hepatitis C virus (HCV) is a global health concern that can cause severe liver disease, such as cirrhosis and hepatocellular carcinoma. Control of HCV requires vigorous T-cell responses, yet CD4 + T cells in chronic HCV patients are dysfunctional. T follicular regulatory (Tfr) cells are a subset of regulatory T cells that suppress T follicular helper (Tfh) cells and the generation of high affinity antibody-producing B cells. In this study, we examined the accumulation of Tfr cells in the liver compartment during chronic HCV infection and defined the cellular and molecular mechanisms underlying their expansion. Our analysis revealed a substantial population of Tfr cells in livers of chronic HCV patients that is absent in liver tissues from nonviral hepatitis or healthy subjects. Coculture of PBMCs from healthy subjects with HCV-infected hepatoma cells resulted in preferential expansion of circulating Tfr cells, leading to suppression of Tfh cells. Additionally, coculture of tonsillar cells with infected hepatoma cells lead to an expansion of germinal center Tfr. Notably, expansion was mediated by transforming growth factor beta (TGF-β)-containing exosomes released from HCV-infected hepatocytes given that blockade of exosome-associated TGF-β or inhibition of exosome release abrogated Tfr expansion. These results show that liver-derived exosomes play a pivotal role in the accumulation of Tfr cells, likely leading to suppression of Tfh responses in HCV-infected patients. Our study identifies a novel pathway in which HCV infection in hepatocytes exacerbates Tfr cell responses to subvert antiviral immunity. (Hepatology 2018;67:71-85). © 2017 by the American Association for the Study of Liver Diseases.

Quantification of organic solvents in aquatic toys and swimming learning devices and evaluation of their influence on the smell properties of the corresponding products.

PubMed

Wiedmer, Christoph; Buettner, Andrea

2018-04-01

Based on the observation that the characteristic odour of inflatable aquatic toys for children is predominantly caused by residues of hazardous organic solvents, the concentrations of cyclohexanone, isophorone and phenol were determined in a selection of 20 products obtained from online suppliers located in Germany. Analytes were extracted with dichloromethane after the addition of non-labelled internal standards, and the volatile fraction was isolated using solvent-assisted flavour evaporation (SAFE). Extracts were then concentrated by Vigreux distillation and analysed by means of gas chromatography with mass spectrometric detection (GC-MS). Furthermore, each sample was evaluated regarding its specific olfactory properties by an expert sensory panel. While some samples did not contain significant amounts of solvents, cyclohexanone concentrations above the lower limit of quantification (LLOQ) were determined in nine samples with six samples containing high concentrations ranging from about 1 to 7 g/kg cyclohexanone. Isophorone concentrations above the LLOQ were observed in eight samples. Thereby, six products contained between 0.3 and 1.6 g/kg isophorone and the remaining two samples contained even about 5 g/kg isophorone, each. Likewise, phenol concentrations exceeded the LLOQ in 14 cases, with four samples containing elevated amounts ranging from about 140 to 280 mg/kg phenol.

Improving of Mechanical and Shape-Memory Properties in Hyperbranched Epoxy Shape-Memory Polymers

NASA Astrophysics Data System (ADS)

Santiago, David; Fabregat-Sanjuan, Albert; Ferrando, Francesc; De la Flor, Silvia

2016-09-01

A series of shape-memory epoxy polymers were synthesized using an aliphatic amine and two different commercial hyperbranched poly(ethyleneimine)s with different molecular weights as crosslinking agents. Thermal, mechanical, and shape-memory properties in materials modified with different hyperbranched polymers were analyzed and compared in order to establish the effect of the structure and the molecular weight of the hyperbranched polymers used. The presence of hyperbranched polymers led to more heterogeneous networks, and the crosslinking densities of which increase as the hyperbranched polymer content increases. The transition temperatures can be tailored from 56 to 117 °C depending on the molecular weight and content of the hyperbranched polymer. The mechanical properties showed excellent values in all formulations at room temperature and, specially, at T_{{g}}^{{E^' with stress at break as high as 15 MPa and strain at break as high as 60 %. The shape-memory performances revealed recovery ratios around 95 %, fixity ratios around 97 %, and shape-recovery velocities as high as 22 %/min. The results obtained in this study reveal that hyperbranched polymers with different molecular weights can be used to enhance the thermal and mechanical properties of epoxy-based SMPs while keeping excellent shape-memory properties.

A pulse-shape discrimination method for improving Gamma-ray spectrometry based on a new digital shaping filter

NASA Astrophysics Data System (ADS)

Qin, Zhang-jian; Chen, Chuan; Luo, Jun-song; Xie, Xing-hong; Ge, Liang-quan; Wu, Qi-fan

2018-04-01

It is a usual practice for improving spectrum quality by the mean of designing a good shaping filter to improve signal-noise ratio in development of nuclear spectroscopy. Another method is proposed in the paper based on discriminating pulse-shape and discarding the bad pulse whose shape is distorted as a result of abnormal noise, unusual ballistic deficit or bad pulse pile-up. An Exponentially Decaying Pulse (EDP) generated in nuclear particle detectors can be transformed into a Mexican Hat Wavelet Pulse (MHWP) and the derivation process of the transform is given. After the transform is performed, the baseline drift is removed in the new MHWP. Moreover, the MHWP-shape can be discriminated with the three parameters: the time difference between the two minima of the MHWP, and the two ratios which are from the amplitude of the two minima respectively divided by the amplitude of the maximum in the MHWP. A new type of nuclear spectroscopy was implemented based on the new digital shaping filter and the Gamma-ray spectra were acquired with a variety of pulse-shape discrimination levels. It had manifested that the energy resolution and the peak-Compton ratio were both improved after the pulse-shape discrimination method was used.

Both endo-siRNAs and tRNA-derived small RNAs are involved in the differentiation of primitive eukaryote Giardia lamblia

PubMed Central

Liao, Jian-You; Guo, Yan-Hua; Zheng, Ling-Ling; Li, Yan; Xu, Wen-Li; Zhang, Yu-Chan; Zhou, Hui; Lun, Zhao-Rong; Ayala, Francisco J.; Qu, Liang-Hu

2014-01-01

Small RNAs (sRNAs), including microRNAs and endogenous siRNAs (endo-siRNAs), regulate most important biologic processes in eukaryotes, such as cell division and differentiation. Although sRNAs have been extensively studied in various eukaryotes, the role of sRNAs in the early emergence of eukaryotes is unclear. To address these questions, we deep sequenced the sRNA transcriptome of four different stages in the differentiation of Giardia lamblia, one of the most primitive eukaryotes. We identified a large number of endo-siRNAs in this fascinating parasitic protozoan and found that they were produced from live telomeric retrotransposons and three genomic regions (i.e., endo-siRNA generating regions [eSGRs]). eSGR-derived endo-siRNAs were proven to target mRNAs in trans. Gradual up-regulation of endo-siRNAs in the differentiation of Giardia suggested that they might be involved in the regulation of this process. This hypothesis was supported by the impairment of the differentiation ability of Giardia when GLDICER, essential for the biogenesis of endo-siRNAs, was knocked down. Endo-siRNAs are not the only sRNA regulators in Giardia differentiation, because a great number of tRNAs-derived sRNAs showed more dramatic expression changes than endo-siRNAs in this process. We totally identified five novel kinds of tRNAs-derived sRNAs and found that the biogenesis in four of them might be correlated with that of stress-induced tRNA-derived RNA (sitRNA), which was discovered in our previous studies. Our studies reveal an unexpected complex panorama of sRNA in G. lamblia and shed light on the origin and functional evolution of eukaryotic sRNAs. PMID:25225396

Analysis on the geometrical shape of T-honeycomb structure by finite element method (FEM)

NASA Astrophysics Data System (ADS)

Zain, Fitri; Rosli, Muhamad Farizuan; Effendi, M. S. M.; Abdullah, Mohamad Hariri

2017-09-01

Geometric in design is much related with our life. Each of the geometrical structure interacts with each other. The overall shape of an object contains other shape inside, and there shapes create a relationship between each other in space. Besides that, how geometry relates to the function of the object have to be considerate. In this project, the main purpose was to design the geometrical shape of modular furniture with the shrinking of Polyethylene Terephthalate (PET) jointing system that has good strength when applied load on it. But, the goal of this paper is focusing on the analysis of Static Cases by FEM of the hexagonal structure to obtain the strength when load apply on it. The review from the existing product has many information and very helpful to finish this paper. This project focuses on hexagonal shape that distributed to become a shelf inspired by honeycomb structure. It is very natural look and simple in shape and its modular structure more easily to separate and combine. The method discusses on chapter methodology are the method used to analysis the strength when the load applied to the structure. The software used to analysis the structure is Finite Element Method from CATIA V5R21 software. Bending test is done on the jointing part between the edges of the hexagonal shape by using Universal Tensile Machine (UTM). The data obtained have been calculate by bending test formulae and sketch the graph between flexural strains versus flexural stress. The material selection of the furniture is focused on wood. There are three different types of wood such as balsa, pine and oak, while the properties of jointing also be mentioned in this thesis. Hence, the design structural for honeycomb shape already have in the market but this design has main objective which has a good strength that can withstand maximum load and offers more potentials in the form of furniture.

Global shape mimicry of tRNA within a viral internal ribosome entry site mediates translational reading frame selection

PubMed Central

Au, Hilda H.; Cornilescu, Gabriel; Mouzakis, Kathryn D.; Ren, Qian; Burke, Jordan E.; Lee, Seonghoon; Butcher, Samuel E.; Jan, Eric

2015-01-01

The dicistrovirus intergenic region internal ribosome entry site (IRES) adopts a triple-pseudoknotted RNA structure and occupies the core ribosomal E, P, and A sites to directly recruit the ribosome and initiate translation at a non-AUG codon. A subset of dicistrovirus IRESs directs translation in the 0 and +1 frames to produce the viral structural proteins and a +1 overlapping open reading frame called ORFx, respectively. Here we show that specific mutations of two unpaired adenosines located at the core of the three-helical junction of the honey bee dicistrovirus Israeli acute paralysis virus (IAPV) IRES PKI domain can uncouple 0 and +1 frame translation, suggesting that the structure adopts distinct conformations that contribute to 0 or +1 frame translation. Using a reconstituted translation system, we show that ribosomes assembled on mutant IRESs that direct exclusive 0 or +1 frame translation lack reading frame fidelity. Finally, a nuclear magnetic resonance/small-angle X-ray scattering hybrid approach reveals that the PKI domain of the IAPV IRES adopts an RNA structure that resembles a complete tRNA. The tRNA shape-mimicry enables the viral IRES to gain access to the ribosome tRNA-binding sites and form intermolecular contacts with the ribosome that are necessary for initiating IRES translation in a specific reading frame. PMID:26554019

Tissue reservoirs of antiviral T cell immunity in persistent human CMV infection

PubMed Central

Gordon, Claire L.; Thome, Joseph J.C.; Igarashi, Suzu

2017-01-01

T cell responses to viruses are initiated and maintained in tissue sites; however, knowledge of human antiviral T cells is largely derived from blood. Cytomegalovirus (CMV) persists in most humans, requires T cell immunity to control, yet tissue immune responses remain undefined. Here, we investigated human CMV-specific T cells, virus persistence and CMV-associated T cell homeostasis in blood, lymphoid, mucosal and secretory tissues of 44 CMV seropositive and 28 seronegative donors. CMV-specific T cells were maintained in distinct distribution patterns, highest in blood, bone marrow (BM), or lymph nodes (LN), with the frequency and function in blood distinct from tissues. CMV genomes were detected predominantly in lung and also in spleen, BM, blood and LN. High frequencies of activated CMV-specific T cells were found in blood and BM samples with low virus detection, whereas in lung, CMV-specific T cells were present along with detectable virus. In LNs, CMV-specific T cells exhibited quiescent phenotypes independent of virus. Overall, T cell differentiation was enhanced in sites of viral persistence with age. Together, our results suggest tissue T cell reservoirs for CMV control shaped by both viral and tissue-intrinsic factors, with global effects on homeostasis of tissue T cells over the lifespan. PMID:28130404

Tissue reservoirs of antiviral T cell immunity in persistent human CMV infection.

PubMed

Gordon, Claire L; Miron, Michelle; Thome, Joseph J C; Matsuoka, Nobuhide; Weiner, Joshua; Rak, Michael A; Igarashi, Suzu; Granot, Tomer; Lerner, Harvey; Goodrum, Felicia; Farber, Donna L

2017-03-06

T cell responses to viruses are initiated and maintained in tissue sites; however, knowledge of human antiviral T cells is largely derived from blood. Cytomegalovirus (CMV) persists in most humans, requires T cell immunity to control, yet tissue immune responses remain undefined. Here, we investigated human CMV-specific T cells, virus persistence and CMV-associated T cell homeostasis in blood, lymphoid, mucosal and secretory tissues of 44 CMV seropositive and 28 seronegative donors. CMV-specific T cells were maintained in distinct distribution patterns, highest in blood, bone marrow (BM), or lymph nodes (LN), with the frequency and function in blood distinct from tissues. CMV genomes were detected predominantly in lung and also in spleen, BM, blood and LN. High frequencies of activated CMV-specific T cells were found in blood and BM samples with low virus detection, whereas in lung, CMV-specific T cells were present along with detectable virus. In LNs, CMV-specific T cells exhibited quiescent phenotypes independent of virus. Overall, T cell differentiation was enhanced in sites of viral persistence with age. Together, our results suggest tissue T cell reservoirs for CMV control shaped by both viral and tissue-intrinsic factors, with global effects on homeostasis of tissue T cells over the lifespan. @Gordon et al.

T-T Neutron Spectrum from Inertial Confinement Implosions

NASA Astrophysics Data System (ADS)

Bacher, A. D.; Casey, D. T.; Frenje, J. A.; Gatu Johnson, M. J.; Manuel, M.; Sinenian, N.; Zylstra, A. B.; Séguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu; Radha, P. B.; Meyerhofer, D. D.; Sangster, T. C.; McNabb, D. P.; Amendt, P. A.; Boyd, R. N.; Caggiano, J. A.; Hatchett, S. P.; Pino, J. E.; Quaglioni, S.; Rygg, J. R.; Thompson, I. J.; Herrmann, H. W.; Kim, Y. H.

2013-08-01

A new technique that uses inertial confinement implosions for measuring low-energy nuclear reactions important to nuclear astrophysics is described. Simultaneous measurements of n-D and n-T elastic scattering at 14.1 MeV using deuterium-tritium gas-filled capsules provide a proof of principle for this technique. Measurements have been made of D(d,p)T (dd) and T(t,2n)4He (tt) reaction yields relative to the D(t,n)4He (dt) reaction yield for deuterium-tritium mixtures with f T / f D between 0.62 and 0.75 and for a wide range of ion temperatures to test our understanding of the implosion processes. Measurements of the shape of the neutron spectrum from the T(t,2n)4He reaction have been made for each of these target configurations.

An approach for accurate simulation of liquid mixing in a T-shaped micromixer.

PubMed

Matsunaga, Takuya; Lee, Ho-Joon; Nishino, Koichi

2013-04-21

In this paper, we propose a new computational method for efficient evaluation of the fluid mixing behaviour in a T-shaped micromixer with a rectangular cross section at high Schmidt number under steady state conditions. Our approach enables a low-cost high-quality simulation based on tracking of fluid particles for convective fluid mixing and posterior solving of a model of the species equation for molecular diffusion. The examined parameter range is Re = 1.33 × 10(-2) to 240 at Sc = 3600. The proposed method is shown to simulate well the mixing quality even in the engulfment regime, where the ordinary grid-based simulation is not able to obtain accurate solutions with affordable mesh sizes due to the numerical diffusion at high Sc. The obtained results agree well with a backward random-walk Monte Carlo simulation, by which the accuracy of the proposed method is verified. For further investigation of the characteristics of the proposed method, the Sc dependency is examined in a wide range of Sc from 10 to 3600 at Re = 200. The study reveals that the model discrepancy error emerges more significantly in the concentration distribution at lower Sc, while the resulting mixing quality is accurate over the entire range.

Maritime patrol aircraft engine study, General Electric Derivative Engines. Volume II. Appendix A: performance data, Ge27/T3 study A1 turboprop. Final report, October 1978-April 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirschkron, R.; Davis, R.H.; Warren, R.E.

1979-04-30

This study developed data on General Electric common core derivative engines for use in Maritime Patrol Aircraft (MPA) concept formulation studies. The study included the screening of potential General Electric turbofan and turboprop/turboshaft engines and the preparation of technical and planning information on three of the most promising engine candidates. Screening of General Electric derivative candidates was performed utilizing an analytical MPA model using synthesized mission profiles to rank the candidates in terms of fuel consumption, weight, cost and complexity. The three turboprop engines selected for further study were as follows: TF34 growth derivative version with boost and new LPTmore » (TF34/T7 Study A1), F404 derivative with booster stages and new LPT (F404/T1 Study A1), and GE27 scaled and boosted study engine (GE27/T3 Study A1). Volume I summarizes the screening analysis and contains technical, planning, installation, cost and development data for the three selected turboprop engines. Volumes II, III and IV of this report contain the detailed performance data estimates for the GE27/T3 Study A1, TF34/T7 Study A1 and F404/T1 Study A1 turboprop engines, respectively.« less

Maritime patrol aircraft engine study, General Electric Derivative Engines. Volume IV. Apendix C: performance data, F404/T1 study A1 turboprop. Final report, October 1978-April 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirschkron, R.; Davis, R.H.; Warren, R.E.

1979-04-30

This study developed data on General Electric common core derivative engines for use in Maritime Patrol Aircraft (MPA) concept formulation studies. The study included the screening of potential General Electric turbofan and turboprop/turboshaft engines and the preparation of technical and planning information on three of the most promising engine candidates. Screening of General Electric derivative candidates was performed utilizing an analytical MPA model using synthesized mission profiles to rank the candidates in terms of fuel consumption, weight, cost and complexity. The three turboprop engines selected for further study were as follows: TF34 growth derivative version with boost and new LPTmore » (TF34/T7 Study A1), F404 derivative with booster stages and new LPT (F404/T1 Study A1), and GE27 scaled and boosted study engine (GE27/T3 Study A1). Volume I summarizes the screening analysis and contains technical, planning, installation, cost and development data for the three selected turboprop engines. Volumes II, III and IV of this report contain the detailed performance data estimates for the GE27/T3 Study A1, TF34/T7 Study A1 and F404/T1 Study A1 turboprop engines, respectively.« less

Differential and transferable modulatory effects of mesenchymal stromal cell-derived extracellular vesicles on T, B and NK cell functions

PubMed Central

Di Trapani, Mariano; Bassi, Giulio; Midolo, Martina; Gatti, Alessandro; Kamga, Paul Takam; Cassaro, Adriana; Carusone, Roberta; Adamo, Annalisa; Krampera, Mauro

2016-01-01

Mesenchymal stromal cells (MSCs) are multipotent cells, immunomodulatory stem cells that are currently used for regenerative medicine and treatment of a number of inflammatory diseases, thanks to their ability to significantly influence tissue microenvironments through the secretion of large variety of soluble factors. Recently, several groups have reported the presence of extracellular vesicles (EVs) within MSC secretoma, showing their beneficial effect in different animal models of disease. Here, we used a standardized methodological approach to dissect the immunomodulatory effects exerted by MSC-derived EVs on unfractionated peripheral blood mononuclear cells and purified T, B and NK cells. We describe here for the first time: i. direct correlation between the degree of EV-mediated immunosuppression and EV uptake by immune effector cells, a phenomenon further amplified following MSC priming with inflammatory cytokines; ii. induction in resting MSCs of immunosuppressive properties towards T cell proliferation through EVs obtained from primed MSCs, without any direct inhibitory effect towards T cell division. Our conclusion is that the use of reproducible and validated assays is not only useful to characterize the mechanisms of action of MSC-derived EVs, but is also capable of justifying EV potential use as alternative cell-free therapy for the treatment of human inflammatory diseases. PMID:27071676

Differential and transferable modulatory effects of mesenchymal stromal cell-derived extracellular vesicles on T, B and NK cell functions.

PubMed

Di Trapani, Mariano; Bassi, Giulio; Midolo, Martina; Gatti, Alessandro; Kamga, Paul Takam; Cassaro, Adriana; Carusone, Roberta; Adamo, Annalisa; Krampera, Mauro

2016-04-13

Mesenchymal stromal cells (MSCs) are multipotent cells, immunomodulatory stem cells that are currently used for regenerative medicine and treatment of a number of inflammatory diseases, thanks to their ability to significantly influence tissue microenvironments through the secretion of large variety of soluble factors. Recently, several groups have reported the presence of extracellular vesicles (EVs) within MSC secretoma, showing their beneficial effect in different animal models of disease. Here, we used a standardized methodological approach to dissect the immunomodulatory effects exerted by MSC-derived EVs on unfractionated peripheral blood mononuclear cells and purified T, B and NK cells. We describe here for the first time: i. direct correlation between the degree of EV-mediated immunosuppression and EV uptake by immune effector cells, a phenomenon further amplified following MSC priming with inflammatory cytokines; ii. induction in resting MSCs of immunosuppressive properties towards T cell proliferation through EVs obtained from primed MSCs, without any direct inhibitory effect towards T cell division. Our conclusion is that the use of reproducible and validated assays is not only useful to characterize the mechanisms of action of MSC-derived EVs, but is also capable of justifying EV potential use as alternative cell-free therapy for the treatment of human inflammatory diseases.

Faster computation of exact RNA shape probabilities.

PubMed

Janssen, Stefan; Giegerich, Robert

2010-03-01

Abstract shape analysis allows efficient computation of a representative sample of low-energy foldings of an RNA molecule. More comprehensive information is obtained by computing shape probabilities, accumulating the Boltzmann probabilities of all structures within each abstract shape. Such information is superior to free energies because it is independent of sequence length and base composition. However, up to this point, computation of shape probabilities evaluates all shapes simultaneously and comes with a computation cost which is exponential in the length of the sequence. We device an approach called RapidShapes that computes the shapes above a specified probability threshold T by generating a list of promising shapes and constructing specialized folding programs for each shape to compute its share of Boltzmann probability. This aims at a heuristic improvement of runtime, while still computing exact probability values. Evaluating this approach and several substrategies, we find that only a small proportion of shapes have to be actually computed. For an RNA sequence of length 400, this leads, depending on the threshold, to a 10-138 fold speed-up compared with the previous complete method. Thus, probabilistic shape analysis has become feasible in medium-scale applications, such as the screening of RNA transcripts in a bacterial genome. RapidShapes is available via http://bibiserv.cebitec.uni-bielefeld.de/rnashapes

Tumor and Endothelial Cell-Derived Microvesicles Carry Distinct CEACAMs and Influence T-Cell Behavior

PubMed Central

Muturi, Harrison T.; Dreesen, Janine D.; Nilewski, Elena; Jastrow, Holger; Giebel, Bernd; Ergun, Suleyman; Singer, Bernhard B.

2013-01-01

Normal and malignant cells release a variety of different vesicles into their extracellular environment. The most prominent vesicles are the microvesicles (MVs, 100-1 000 nm in diameter), which are shed of the plasma membrane, and the exosomes (70-120 nm in diameter), derivates of the endosomal system. MVs have been associated with intercellular communication processes and transport numerous proteins, lipids and RNAs. As essential component of immune-escape mechanisms tumor-derived MVs suppress immune responses. Additionally, tumor-derived MVs have been found to promote metastasis, tumor-stroma interactions and angiogenesis. Since members of the carcinoembryonic antigen related cell adhesion molecule (CEACAM)-family have been associated with similar processes, we studied the distribution and function of CEACAMs in MV fractions of different human epithelial tumor cells and of human and murine endothelial cells. Here we demonstrate that in association to their cell surface phenotype, MVs released from different human epithelial tumor cells contain CEACAM1, CEACAM5 and CEACAM6, while human and murine endothelial cells were positive for CEACAM1 only. Furthermore, MVs derived from CEACAM1 transfected CHO cells carried CEACAM1. In terms of their secretion kinetics, we show that MVs are permanently released in low doses, which are extensively increased upon cellular starvation stress. Although CEACAM1 did not transmit signals into MVs it served as ligand for CEACAM expressing cell types. We gained evidence that CEACAM1-positive MVs significantly increase the CD3 and CD3/CD28-induced T-cell proliferation. All together, our data demonstrate that MV-bound forms of CEACAMs play important roles in intercellular communication processes, which can modulate immune response, tumor progression, metastasis and angiogenesis. PMID:24040308

Overexpression of Lhx2 suppresses proliferation of human T cell acute lymphoblastic leukemia-derived cells, partly by reducing LMO2 protein levels.

PubMed

Miyashita, Kazuya; Kitajima, Kenji; Goyama, Susumu; Kitamura, Toshio; Hara, Takahiko

2018-01-15

T cell acute lymphoblastic leukemia (T-ALL) is a malignant cancer with poor prognosis. The transcriptional co-factor LIM domain only 2 (LMO2) and its target gene HHEX are essential for self-renewal of T cell precursors and T-ALL etiology. LMO2 directly associates with LDB1 in a large DNA-containing nuclear complex and controls the transcription of T-ALL-related genes. Recently, we reported that overexpression of the LIM-homeodomain transcription factor, Lhx2, results in liberation of the Lmo2 protein from the Lmo2-Ldb1 complex, followed by ubiquitin proteasome mediated degradation. Here, we found that proliferation of five human T-ALL-derived cell lines, including CCRF-CEM, was significantly suppressed by retroviral overexpression of Lhx2. The majority of Lhx2-transduced CCRF-CEM cells arrested in G 0 phase and subsequently underwent apoptosis. Expression of LMO2 protein as well as HHEX, ERG, HES1 and MYC genes was repressed in CCRF-CEM cells by transduction with Lhx2. Lhx2-mediated growth inhibition was partially rescued by simultaneous overexpression of Lmo2; however, both the C-terminal LIM domain and the homeodomain of Lhx2 were required for its growth-suppressive activity. These data indicate that Lhx2 is capable of blocking proliferation of T-ALL-derived cells by both LMO2-dependent and -independent means. We propose Lhx2 as a new molecular tool for anti-T-ALL drug development. Copyright © 2017 Elsevier Inc. All rights reserved.

Refractive index and strain sensor based on twin-core fiber with a novel T-shaped taper

NASA Astrophysics Data System (ADS)

Zhang, Chuanbiao; Ning, Tigang; Li, Jing; Zheng, JingJing; Gao, Xuekai; Pei, Li

2018-06-01

A compact in-fiber Mach-Zehnder interferometer (MZI) based on twin-core fiber (TCF) with a novel T-shaped taper is proposed and demonstrated. The taper was firstly fabricated by a short section of TCF, and then spliced with a section of cleaved single mode fiber (SMF). When the light transmit into the TCF, multiple modes will be excited and will propagate within the TCF. In experiment, the proposed device had a maximum interferometric extinction ratio about 17 dB. And the refractive index (RI), strain, and temperature response properties of the sensor have been investigated, which show a relatively high RI, strain sensitivity and low temperature cross sensitivity. Hence, the sensor can be a suitable candidate in the biochemical and physical sensing applications. And due to its easy and controllable fabrication, the novel drawing technology can be applied to more multicore optical fibers.

Primal-dual methods of shape sensitivity analysis for curvilinear cracks with nonpenetration

NASA Astrophysics Data System (ADS)

Kovtunenko, V. A.

2006-10-01

Based on a level-set description of a crack moving with a given velocity, the problem of shape perturb-ation of the crack is considered. Nonpenetration conditions are imposed between opposite crack surfaces which result in a constrained minimization problem describing equilibrium of a solid with the crack. We suggest a minimax formulation of the state problem thus allowing curvilinear (nonplanar) cracks for the consideration. Utilizing primal-dual methods of shape sensitivity analysis we obtain the general formula for a shape derivative of the potential energy, which describes an energy-release rate for the curvilinear cracks. The conditions sufficient to rewrite it in the form of a path-independent integral (J-integral) are derived.

SHERMAN - A shape-based thermophysical model II. Application to 8567 (1996 HW1)

NASA Astrophysics Data System (ADS)

Howell, E. S.; Magri, C.; Vervack, R. J.; Nolan, M. C.; Taylor, P. A.; Fernández, Y. R.; Hicks, M. D.; Somers, J. M.; Lawrence, K. J.; Rivkin, A. S.; Marshall, S. E.; Crowell, J. L.

2018-03-01

We apply a new shape-based thermophysical model, SHERMAN, to the near-Earth asteroid (NEA) 8567 (1996 HW1) to derive surface properties. We use the detailed shape model of Magri et al. (2011) for this contact binary NEA to analyze spectral observations (2-4.1 microns) obtained at the NASA IRTF on several different dates to find thermal parameters that match all the data. Visible and near-infrared (0.8-2.5 microns) spectral observations are also utilized in a self-consistent way. We find that an average visible albedo of 0.33, thermal inertia of 70 (SI units) and surface roughness of 50% closely match the observations. The shape and orientation of the asteroid is very important to constrain the thermal parameters to be consistent with all the observations. Multiple viewing geometries are equally important to achieve a robust solution for small, non-spherical NEAs. We separate the infrared beaming effects of shape, viewing geometry and surface roughness for this asteroid and show how their effects combine. We compare the diameter and albedo that would be derived from the thermal observations assuming a spherical shape with those from the shape-based model. We also discuss how observations from limited viewing geometries compare to the solution from multiple observations. The size that would be derived from the individual observation dates varies by 20% from the best-fit solution, and can be either larger or smaller. If the surface properties are not homogeneous, many solutions are possible, but the average properties derived here are very tightly constrained by the multiple observations, and give important insights into the nature of small NEAs.

Essential requirement of I-A region-identical host bone marrow or bone marrow-derived cells for tumor neutralization by primed L3T4+ T cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozawa, H.; Iwaguchi, T.; Kataoka, T.

1987-12-01

The antitumor activity of Meth A-hyperimmunized BALB/c mouse spleen cells (Meth A-Im-SPL) was assayed by the Winn test in H-2 incompatible bone marrow chimeras in closed colony CD-1 (nu/nu), inbred DDD/1(nu/nu) (H-2s), or inbred BALB/c(nu/nu) (H-2d) mice as recipients. We found that Meth A-Im-SPL suppressed Meth A growth in the chimera nude mice which were reconstituted with bone marrow cells of the H-2d haplotype (i.e., BALB/c, DBA/2 and B10.D2), but not in the chimeras which were reconstituted with bone marrow cells of the H-2a, H-2b, or H-2k haplotype (i.e., B10.A, B10, and B10.BR). These results suggested that H-2 restriction occurredmore » between Meth A-Im-SPL and bone marrow or bone marrow-derived cells in tumor neutralization. Furthermore, Meth A-Im-SPL did not suppress Meth 1 tumors (antigenically distinct from Meth A tumors) in the presence or absence of mitomycin C-treated Meth A in a Winn assay. These results suggested that there is tumor specificity in the effector phase as well as in the induction phase. The phenotype of the effectors in the Meth A-Im-SPL was Thy-1.2+ and L3T4+, because Meth A-Im-SPL lost their antitumor activity with pretreatment with anti-Thy-1.2 monoclonal antibody (mAb) and complement or anti-L3T4 mAb and complement, but not with anti-Lyt-2.2 mAb and complement or complement alone. Positively purified L3T4+ T cells from Meth A-Im-SPL (Meth A-Im-L3T4), obtained by the panning method, suppressed the tumor growth in the chimera nude mice which were reconstituted with bone marrow cells of B10.KEA2 mice (that were I-A region-identical with Meth A-Im-L3T4 cells but not others in H-2) as well as B10.D2 cells (that were fully identical with Meth A-Im-L3T4 cells in H-2). We conclude that Meth A-Im-SPL (L3T4+) neutralized the tumors in collaboration with I-A region-identical host bone marrow or bone marrow-derived cells, and the neutralization was not accompanied by the bystander effect.« less

Collagen-derived dipeptide prolyl-hydroxyproline promotes differentiation of MC3T3-E1 osteoblastic cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimira, Yoshifumi, E-mail: kimira@josai.ac.jp; Ogura, Kana; Taniuchi, Yuri

Highlights: • Pro-Hyp did not affect MC3T3-E1 cell proliferation and matrix mineralization. • Pro-Hyp significantly increased alkaline phosphatase activity. • Pro-Hyp significantly upregulated gene expression of Runx2, Osterix, and Col1α1. - Abstract: Prolyl-hydroxyproline (Pro-Hyp) is one of the major constituents of collagen-derived dipeptides. The objective of this study was to investigate the effects of Pro-Hyp on the proliferation and differentiation of MC3T3-E1 osteoblastic cells. Addition of Pro-Hyp did not affect MC3T3-E1 cell proliferation and matrix mineralization but alkaline phosphatase activity was significantly increased. Furthermore, cells treated with Pro-Hyp significantly upregulated gene expression of Runx2, Osterix, and Col1α1. These results indicatemore » that Pro-Hyp promotes osteoblast differentiation. This study demonstrates for the first time that Pro-Hyp has a positive effect on osteoblast differentiation with upregulation of Runx2, Osterix, and Collα1 gene expression.« less

Quantitative Skeletal Muscle MRI: Part 1, Derived T2 Fat Map in Differentiation Between Boys With Duchenne Muscular Dystrophy and Healthy Boys.

PubMed

Johnston, Jennifer H; Kim, Hee Kyung; Merrow, Arnold C; Laor, Tal; Serai, Suraj; Horn, Paul S; Kim, Dong Hoon; Wong, Brenda L

2015-08-01

The purpose of this study was to validate derived T2 maps as an objective measure of muscular fat for discrimination between boys with Duchenne muscular dystrophy (DMD) and healthy boys. Forty-two boys with DMD (mean age, 9.9 years) and 31 healthy boys (mean age, 11.4 years) were included in the study. Age, body mass index, and clinical function scale grade were evaluated. T1-weighted MR images and T2 maps with and without fat suppression were obtained. Fatty infiltration was graded 0-4 on T1-weighted images, and derived T2 fat values (difference between mean T2 values from T2 maps with and without fat suppression) of the gluteus maximus and vastus lateralis muscles were calculated. Group comparisons were performed. The upper limit of the 95% reference interval of T2 fat values from the control group was applied. There was no significant difference in age or body mass index between groups. All healthy boys and 19 boys (45.2%) with DMD had a normal clinical function scale grade. Grade 1 fatty infiltration was seen in 90.3% (gluteus maximus) and 71.0% (vastus lateralis) of healthy boys versus 33.3% (gluteus maximus) and 52.4% (vastus lateralis) of boys with DMD. T2 fat values of boys with DMD were significantly longer than in the control group (p < 0.001). Using a 95% reference interval for healthy boys for the gluteus maximus (28.3 milliseconds) allowed complete separation from boys with DMD (100% sensitivity, 100% specificity), whereas the values for the vastus lateralis (7.28 milliseconds) resulted in 83.3% sensitivity and 100% specificity. Measurement of muscular fat with T2 maps is accurate for differentiating boys with DMD from healthy boys.

Higher frequencies of GARP(+)CTLA-4(+)Foxp3(+) T regulatory cells and myeloid-derived suppressor cells in hepatocellular carcinoma patients are associated with impaired T-cell functionality.

PubMed

Kalathil, Suresh; Lugade, Amit A; Miller, Austin; Iyer, Renuka; Thanavala, Yasmin

2013-04-15

The extent to which T-cell-mediated immune surveillance is impaired in human cancer remains a question of major importance, given its potential impact on the development of generalized treatments of advanced disease where the highest degree of heterogeneity exists. Here, we report the first global analysis of immune dysfunction in patients with advanced hepatocellular carcinoma (HCC). Using multi-parameter fluorescence-activated cell sorting analysis, we quantified the cumulative frequency of regulatory T cells (Treg), exhausted CD4(+) helper T cells, and myeloid-derived suppressor cells (MDSC) to gain concurrent views on the overall level of immune dysfunction in these inoperable patients. We documented augmented numbers of Tregs, MDSC, PD-1(+)-exhausted T cells, and increased levels of immunosuppressive cytokines in patients with HCC, compared with normal controls, revealing a network of potential mechanisms of immune dysregulation in patients with HCC. In dampening T-cell-mediated antitumor immunity, we hypothesized that these processes may facilitate HCC progression and thwart the efficacy of immunotherapeutic interventions. In testing this hypothesis, we showed that combined regimens to deplete Tregs, MDSC, and PD-1(+) T cells in patients with advanced HCC restored production of granzyme B by CD8(+) T cells, reaching levels observed in normal controls and also modestly increased the number of IFN-γ producing CD4(+) T cells. These clinical findings encourage efforts to restore T-cell function in patients with advanced stage disease by highlighting combined approaches to deplete endogenous suppressor cell populations that can also expand effector T-cell populations. ©2013 AACR.

Driving qubit phase gates with sech shaped pulses

NASA Astrophysics Data System (ADS)

Long, Junling; Ku, Hsiang-Sheng; Wu, Xian; Lake, Russell; Barnes, Edwin; Economou, Sophia; Pappas, David

As shown in 1932 by Rozen and Zener, the Rabi model has a unique solution whereby, for a given pulse length or amplitude, a sech(t/sigma) shaped pulse can be used to drive complete oscillations around the Bloch sphere that are independent of detuning with only a resultant detuning-dependent phase accumulation. Using this property, single qubit phase gates and two-qubit CZ gates have been proposed. In this work we explore the effect of different drive pulse shapes, i.e. square, Gaussian, and sech, as a function of detuning for Rabi oscillations of a superconducting transmon qubit. An arbitrary, single-qubit phase gate is demonstrated with the sech(t/sigma) pulse, and full tomography is performed to extract the fidelity. This is the first step towards high fidelity, low leakage two qubit CZ gates, and illustrates the efficacy of using analytic solutions of the qubit drive prior to optimal pulse shaping.

Human adipose tissue-derived mesenchymal stem cells inhibit T-cell lymphoma growth in vitro and in vivo.

PubMed

Ahn, Jin-Ok; Chae, Ji-Sang; Coh, Ye-Rin; Jung, Woo-Sung; Lee, Hee-Woo; Shin, Il-Seob; Kang, Sung-Keun; Youn, Hwa-Young

2014-09-01

Human mesenchymal stem cells (hMSCs) are thought to be one of the most reliable stem cell sources for a variety of cell therapies. This study investigated the anti-tumor effect of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) on EL4 murine T-cell lymphoma in vitro and in vivo. The growth-inhibitory effect of hAT-MSCs on EL4 tumor cells was evaluated using a WST-1 cell proliferation assay. Cell-cycle arrest and apoptosis were investigated by flow cytometry and western blot. To evaluate an anti-tumor effect of hAT-MSCs on T-cell lymphoma in vivo, CM-DiI-labeled hAT-MSCs were circumtumorally injected in tumor-bearing nude mice, and tumor size was measured. hAT-MSCs inhibited T-cell lymphoma growth by altering cell-cycle progression and inducing apoptosis in vitro. hAT-MSCs inhibited tumor growth in tumor-bearing nude mice and prolonged survival time. Immunofluorescence analysis showed that hAT-MSCs migrated to tumor sites. hAT-MSCs suppress the growth of T-cell lymphoma, suggesting a therapeutic option for T-cell lymphoma. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Abdomen and spinal cord segmentation with augmented active shape models.

PubMed

Xu, Zhoubing; Conrad, Benjamin N; Baucom, Rebeccah B; Smith, Seth A; Poulose, Benjamin K; Landman, Bennett A

2016-07-01

Active shape models (ASMs) have been widely used for extracting human anatomies in medical images given their capability for shape regularization of topology preservation. However, sensitivity to model initialization and local correspondence search often undermines their performances, especially around highly variable contexts in computed-tomography (CT) and magnetic resonance (MR) images. In this study, we propose an augmented ASM (AASM) by integrating the multiatlas label fusion (MALF) and level set (LS) techniques into the traditional ASM framework. Using AASM, landmark updates are optimized globally via a region-based LS evolution applied on the probability map generated from MALF. This augmentation effectively extends the searching range of correspondent landmarks while reducing sensitivity to the image contexts and improves the segmentation robustness. We propose the AASM framework as a two-dimensional segmentation technique targeting structures with one axis of regularity. We apply AASM approach to abdomen CT and spinal cord (SC) MR segmentation challenges. On 20 CT scans, the AASM segmentation of the whole abdominal wall enables the subcutaneous/visceral fat measurement, with high correlation to the measurement derived from manual segmentation. On 28 3T MR scans, AASM yields better performances than other state-of-the-art approaches in segmenting white/gray matter in SC.

Abdomen and spinal cord segmentation with augmented active shape models

PubMed Central

Xu, Zhoubing; Conrad, Benjamin N.; Baucom, Rebeccah B.; Smith, Seth A.; Poulose, Benjamin K.; Landman, Bennett A.

2016-01-01

Abstract. Active shape models (ASMs) have been widely used for extracting human anatomies in medical images given their capability for shape regularization of topology preservation. However, sensitivity to model initialization and local correspondence search often undermines their performances, especially around highly variable contexts in computed-tomography (CT) and magnetic resonance (MR) images. In this study, we propose an augmented ASM (AASM) by integrating the multiatlas label fusion (MALF) and level set (LS) techniques into the traditional ASM framework. Using AASM, landmark updates are optimized globally via a region-based LS evolution applied on the probability map generated from MALF. This augmentation effectively extends the searching range of correspondent landmarks while reducing sensitivity to the image contexts and improves the segmentation robustness. We propose the AASM framework as a two-dimensional segmentation technique targeting structures with one axis of regularity. We apply AASM approach to abdomen CT and spinal cord (SC) MR segmentation challenges. On 20 CT scans, the AASM segmentation of the whole abdominal wall enables the subcutaneous/visceral fat measurement, with high correlation to the measurement derived from manual segmentation. On 28 3T MR scans, AASM yields better performances than other state-of-the-art approaches in segmenting white/gray matter in SC. PMID:27610400

Dynamical passage to approximate equilibrium shapes for spinning, gravitating rubble asteroids

NASA Astrophysics Data System (ADS)

Sharma, Ishan; Jenkins, James T.; Burns, Joseph A.

2009-03-01

Many asteroids are thought to be particle aggregates held together principally by self-gravity. Here we study — for static and dynamical situations — the equilibrium shapes of spinning asteroids that are permitted for rubble piles. As in the case of spinning fluid masses, not all shapes are compatible with a granular rheology. We take the asteroid to always be an ellipsoid with an interior modeled as a rigid-plastic, cohesion-less material with a Drucker-Prager yield criterion. Using an approximate volume-averaged procedure, based on the classical method of moments, we investigate the dynamical process by which such objects may achieve equilibrium. We first collapse our dynamical approach to its statical limit to derive regions in spin-shape parameter space that allow equilibrium solutions to exist. At present, only a graphical illustration of these solutions for a prolate ellipsoid following the Drucker-Prager failure law is available [Sharma, I., Jenkins, J.T., Burns, J.A., 2005a. Bull. Am. Astron. Soc. 37, 643; Sharma, I., Jenkins, J.T., Burns, J.A., 2005b. Equilibrium shapes of ellipsoidal soil asteroids. In: García-Rojo, R., Hermann, H.J., McNamara, S. (Eds.), Proceedings of the 5th International Conference on Micromechanics of Granular Media, vol. 1. A.A. Balkema, UK; Holsapple, K.A., 2007. Icarus 187, 500-509]. Here, we obtain the equilibrium landscapes for general triaxial ellipsoids, as well as provide the requisite governing formulae. In addition, we demonstrate that it may be possible to better interpret the results of Richardson et al. [Richardson, D.C., Elankumaran, P., Sanderson, R.E., 2005. Icarus 173, 349-361] within the context of a Drucker-Prager material. The graphical result for prolate ellipsoids in the static limit is the same as those of Holsapple [Holsapple, K.A., 2007. Icarus 187, 500-509] because, when worked out, his final equations will match ours. This is because, though the formalisms to reach these expressions differ, in statics

Fabrication and characterization of shape memory polymers at small-scales

NASA Astrophysics Data System (ADS)

Wornyo, Edem

The objective of this research is to thoroughly investigate the shape memory effect in polymers, characterize, and optimize these polymers for applications in information storage systems. Previous research effort in this field concentrated on shape memory metals for biomedical applications such as stents. Minimal work has been done on shape memory polymers; and the available work on shape memory polymers has not characterized the behaviors of this category of polymers fully. Copolymer shape memory materials based on diethylene glycol dimethacrylate (DEGDMA) crosslinker, and tert butyl acrylate (tBA) monomer are designed. The design encompasses a careful control of the backbone chemistry of the materials. Characterization methods such as dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC); and novel nanoscale techniques such as atomic force microscopy (AFM), and nanoindentation are applied to this system of materials. Designed experiments are conducted on the materials to optimize spin coating conditions for thin films. Furthermore, the recovery, a key for the use of these polymeric materials for information storage, is examined in detail with respect to temperature. In sum, the overarching objectives of the proposed research are to: (i) Design shape memory polymers based on polyethylene glycol dimethacrylate (PEGDMA) and diethylene glycol dimethacrylate (DEGDMA) crosslinkers, 2-hydroxyethyl methacrylate (HEMA) and tert-butyl acrylate monomer (tBA). (ii) Utilize dynamic mechanical analysis (DMA) to comprehend the thermomechanical properties of shape memory polymers based on DEGDMA and tBA. (iii) Utilize nanoindentation and atomic force microscopy (AFM) to understand the nanoscale behavior of these SMPs, and explore the strain storage and recovery of the polymers from a deformed state. (iv) Study spin coating conditions on thin film quality with designed experiments. (iv) Apply neural networks and genetic algorithms to optimize these systems.

In vivo self-gated 23 Na MRI at 7 T using an oval-shaped body resonator.

PubMed

Platt, Tanja; Umathum, Reiner; Fiedler, Thomas M; Nagel, Armin M; Bitz, Andreas K; Maier, Florian; Bachert, Peter; Ladd, Mark E; Wielpütz, Mark O; Kauczor, Hans-Ulrich; Behl, Nicolas G R

2018-02-09

This work faces three challenges of sodium ( 23 Na) torso MRI on the way to quantitative 23 Na MRI: Development of a 23 Na radiofrequency transmit and receive coil covering a large part of the human body in width and length for 23 Na MRI at 7 T; reduction of blurring due to respiration in free-breathing 23 Na MRI using a self-gating approach; and reduction of image noise using a compressed-sensing reconstruction. An oval-shaped birdcage resonator with a large field of view of (400 mm) 3 and a homogeneous transmit and receive field distribution was designed, simulated, and implemented on a 7T MR system. In free-breathing 3-dimensional radial 23 Na MRI (acquisition time ≈ 30 minutes), retrospective respiratory self-gating was applied, which sorts the acquired projections into two respiratory states based on the intrinsic respiration-dependent signal changes. Furthermore, a 3-dimensional dictionary-learning compressed-sensing reconstruction was applied. The developed body coil provided homogeneous radiofrequency excitation (flip angle error of 4.9% in central region of interest of 23 × 13 × 10 cm 3 ) and homogeneous signal reception. The self-gating approach allowed for separation of the full data set into two subsets associated with different respiratory states (inhaled and exhaled), and thereby reduced blurring due to respiration in the separated images. Image noise was markedly reduced by the compressed-sensing algorithm. The presented body coil enables full body width 23 Na MRI with long z-axis coverage at 7 T for the first time. Additionally, the retrospective respiratory self-gating performance is demonstrated for free-breathing lung and abdominal 23 Na MRI in 3 subjects. © 2018 International Society for Magnetic Resonance in Medicine.

Definition and characterization of novel HLA-*A02-restricted CD8+ T cell epitopes derived from JCV polyomavirus with clinical relevance

PubMed Central

Mani, Jiju; Wang, Lei; Hückelhoven, Angela G.; Schmitt, Anita; Gedvilaite, Alma; Jin, Nan; Kleist, Christian; Ho, Anthony D; Schmitt, Michael

2017-01-01

Human JC and BK polyomaviruses (JCV/BKV) can establish a latent infection without any clinical symptoms in healthy individuals. In immunocompromised hosts infection or reactivation of JCV and BKV can cause lethal progressive multifocal leukoencephalopathy (PML) and hemorrhagic cystitis, respectively. Vaccination with JCV/BKV derived antigen epitope peptides or adoptive transfer of virus-specific T cells would constitute an elegant approach to clear virus-infected cells. Furthermore, donor leukocyte infusion (DLI) is another therapeutic approach which could be helpful for patients with JCV/BKV infections. So far, only few immunodominant T cell epitopes of JCV and BKV have been described and therefore is a fervent need for the definition of novel epitopes. In this study, we identified novel T cell epitopes by screening libraries of overlapping peptides derived from the major capsid protein VP1 of JCV. Virus like particles (VLPs) were used to confirm naturally processing. Two human leucocyte antigen (HLA)-A*02-restricted epitopes were characterized by fine mapping with overlapping peptides and nonamer peptide sequences were identified. Cytokine release profile of the epitope-specific T cells was analyzed by enzyme-linked immunospot (ELISPOT) assays and by flow cytometry. We demonstrated that T cell responses were of polyfunctional nature with the potential of epitope-specific killing and cross-reactivity between JCV and BKV. These novel epitopes might constitute a new potential tool to design effective diagnostic and therapeutic approaches against both polyomaviruses. PMID:27705933

Definition and characterization of novel HLA-*A02-restricted CD8+ T cell epitopes derived from JCV polyomavirus with clinical relevance.

PubMed

Mani, Jiju; Wang, Lei; Hückelhoven, Angela G; Schmitt, Anita; Gedvilaite, Alma; Jin, Nan; Kleist, Christian; Ho, Anthony D; Schmitt, Michael

2017-01-10

Human JC and BK polyomaviruses (JCV/BKV) can establish a latent infection without any clinical symptoms in healthy individuals. In immunocompromised hosts infection or reactivation of JCV and BKV can cause lethal progressive multifocal leukoencephalopathy (PML) and hemorrhagic cystitis, respectively. Vaccination with JCV/BKV derived antigen epitope peptides or adoptive transfer of virus-specific T cells would constitute an elegant approach to clear virus-infected cells. Furthermore, donor leukocyte infusion (DLI) is another therapeutic approach which could be helpful for patients with JCV/BKV infections.So far, only few immunodominant T cell epitopes of JCV and BKV have been described and therefore is a fervent need for the definition of novel epitopes. In this study, we identified novel T cell epitopes by screening libraries of overlapping peptides derived from the major capsid protein VP1 of JCV. Virus like particles (VLPs) were used to confirm naturally processing. Two human leucocyte antigen (HLA)-A*02-restricted epitopes were characterized by fine mapping with overlapping peptides and nonamer peptide sequences were identified. Cytokine release profile of the epitope-specific T cells was analyzed by enzyme-linked immunospot (ELISPOT) assays and by flow cytometry. We demonstrated that T cell responses were of polyfunctional nature with the potential of epitope-specific killing and cross-reactivity between JCV and BKV. These novel epitopes might constitute a new potential tool to design effective diagnostic and therapeutic approaches against both polyomaviruses.

Shape-driven 3D segmentation using spherical wavelets.

PubMed

Nain, Delphine; Haker, Steven; Bobick, Aaron; Tannenbaum, Allen

2006-01-01

This paper presents a novel active surface segmentation algorithm using a multiscale shape representation and prior. We define a parametric model of a surface using spherical wavelet functions and learn a prior probability distribution over the wavelet coefficients to model shape variations at different scales and spatial locations in a training set. Based on this representation, we derive a parametric active surface evolution using the multiscale prior coefficients as parameters for our optimization procedure to naturally include the prior in the segmentation framework. Additionally, the optimization method can be applied in a coarse-to-fine manner. We apply our algorithm to the segmentation of brain caudate nucleus, of interest in the study of schizophrenia. Our validation shows our algorithm is computationally efficient and outperforms the Active Shape Model algorithm by capturing finer shape details.

The Impact of Sex Work Interruption on Blood-Derived T Cells in Sex Workers from Nairobi, Kenya.

PubMed

Omollo, Kenneth; Boily-Larouche, Geneviève; Lajoie, Julie; Kimani, Makobu; Cheruiyot, Julianna; Kimani, Joshua; Oyugi, Julius; Fowke, Keith Raymond

Unprotected sexual intercourse exposes the female genital tract (FGT) to semen-derived antigens, which leads to a proinflammatory response. Studies have shown that this postcoital inflammatory response can lead to recruitment of activated T cells to the FGT, thereby increasing risk of HIV infection. The purpose of this study was to evaluate the impact of sex work on activation and memory phenotypes of peripheral T cells among female sex workers (FSW) from Nairobi, Kenya. Thirty FSW were recruited from the Pumwani Sex Workers Cohort, 10 in each of the following groups: HIV-exposed seronegative (at least 7 years in active sex work), HIV positive, and New Negative (HIV negative, less than 3 years in active sex work). Blood was obtained at three different phases (active sex work, abstinence from sex work-sex break, and following resumption of sex work). Peripheral blood mononuclear cells were isolated and stained for phenotypic markers (CD3, CD4, CD8, and CD161), memory phenotype markers (CD45RA and CCR7), activation markers (CD69, HLA-DR, and CD95), and the HIV coreceptor (CCR5). T-cell populations were compared between groups. In HIV-positive women, CD8+CCR5+ T cells declined at the sex break period, while CD4+CD161+ T cells increased when returning to sex work. All groups showed no significant changes in systemic T-cell activation markers following the interruption of sex work, however, significant reductions in naive CD8+ T cells were noted. For each of the study points, HIV positives had higher effector memory and CD8+CD95+ T cells and lower naive CD8+ T cells than the HIV-uninfected groups. Interruption of sex work had subtle effects on systemic T-cell memory phenotypes.

Early differential sensitivity of evoked-potentials to local and global shape during the perception of three-dimensional objects.

PubMed

Leek, E Charles; Roberts, Mark; Oliver, Zoe J; Cristino, Filipe; Pegna, Alan J

2016-08-01

Here we investigated the time course underlying differential processing of local and global shape information during the perception of complex three-dimensional (3D) objects. Observers made shape matching judgments about pairs of sequentially presented multi-part novel objects. Event-related potentials (ERPs) were used to measure perceptual sensitivity to 3D shape differences in terms of local part structure and global shape configuration - based on predictions derived from hierarchical structural description models of object recognition. There were three types of different object trials in which stimulus pairs (1) shared local parts but differed in global shape configuration; (2) contained different local parts but shared global configuration or (3) shared neither local parts nor global configuration. Analyses of the ERP data showed differential amplitude modulation as a function of shape similarity as early as the N1 component between 146-215ms post-stimulus onset. These negative amplitude deflections were more similar between objects sharing global shape configuration than local part structure. Differentiation among all stimulus types was reflected in N2 amplitude modulations between 276-330ms. sLORETA inverse solutions showed stronger involvement of left occipitotemporal areas during the N1 for object discrimination weighted towards local part structure. The results suggest that the perception of 3D object shape involves parallel processing of information at local and global scales. This processing is characterised by relatively slow derivation of 'fine-grained' local shape structure, and fast derivation of 'coarse-grained' global shape configuration. We propose that the rapid early derivation of global shape attributes underlies the observed patterns of N1 amplitude modulations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Investigations into the shape-preserving interpolants using symbolic computation

NASA Technical Reports Server (NTRS)

Lam, Maria

1988-01-01

Shape representation is a central issue in computer graphics and computer-aided geometric design. Many physical phenomena involve curves and surfaces that are monotone (in some directions) or are convex. The corresponding representation problem is given some monotone or convex data, and a monotone or convex interpolant is found. Standard interpolants need not be monotone or convex even though they may match monotone or convex data. Most of the methods of investigation of this problem involve the utilization of quadratic splines or Hermite polynomials. In this investigation, a similar approach is adopted. These methods require derivative information at the given data points. The key to the problem is the selection of the derivative values to be assigned to the given data points. Schemes for choosing derivatives were examined. Along the way, fitting given data points by a conic section has also been investigated as part of the effort to study shape-preserving quadratic splines.

A Novel Method Linking Antigen Presentation by Human Monocyte-Derived Macrophages to CD8+ T Cell Polyfunctionality

PubMed Central

Short, Kirsty R.; Grant, Emma J.; Vissers, Marloes; Reading, Patrick C.; Diavatopoulos, Dimitri A.; Kedzierska, Katherine

2013-01-01

To understand the interactions between innate and adaptive immunity, and specifically how virally infected macrophages impact T cell function, novel assays examining the ability of macrophages to present antigen to CD8+ T cells are needed. In the present study, we have developed a robust in vitro assay to measure how antigen presentation by human monocyte-derived macrophages (MDMs) affects the functional capacity of autologous CD8+ T cells. The assay is based on the polyfunctional characteristics of antigen-specific CD8+ T cells, and is thus called a Mac-CD8 Polyfunctionality Assay. Following purification of monocytes and their maturation to MDMs, MDMs were pulsed with an antigenic peptide to be presented to CD8+ T cells. Peptide-pulsed MDMs were then incubated with antigen-specific CD8+ T cells in order to assess the efficacy of antigen presentation to T cells. CD8+ T cell polyfunctionality was assessed by staining with mAbs to IFN-γ, TNF-α, and CD107a in a multi-color intracellular cytokine staining assay. To highlight the utility of the Mac-CD8 Polyfunctionality Assay, we assessed the effects of influenza infection on the ability of human macrophages to present antigen to CD8+ T cells. We found that influenza infection of human MDMs can alter the effector efficacy of MDMs to activate more CD8+ T cells with cytotoxic capacity. This has important implications for understanding how the virus-infected macrophages affect adaptive immunity at the site of infection. PMID:24312096

γδ T Cells Shape Pre-Immune Peripheral B Cell Populations

PubMed Central

Huang, Yafei; Getahun, Andrew; Heiser, Ryan A.; Detanico, Thiago O.; Aviszus, Katja; Kirchenbaum, Greg A.; Casper, Tamara L.; Huang, Chunjian; Aydintug, M. Kemal; Carding, Simon R.; Ikuta, Koichi; Huang, Hua; Wysocki, Lawrence J.; Cambier, John C.; O’Brien, Rebecca L.; Born, Willi K.

2015-01-01

We previously reported that selective ablation of certain γδ T cell subsets rather than removal of all γδ T cells, strongly affects serum antibody levels in non-immunized mice. This type of manipulation also changed T cells including residual γδ T cells, revealing some interdependence of γδ T cell populations. For example, in mice lacking Vγ4+ and Vγ6+ γδ T cells (B6.TCR-Vγ4−/−/6−/−), we observed expanded Vγ1+ cells, which changed in composition and activation and produced more IL-4 upon stimulation in vitro, increased IL-4 production by αβ T cells as well as spontaneous germinal center formation in the spleen, elevated serum Ig and autoantibodies. We therefore examined B cell populations in this and other γδ-deficient mouse strains. Whereas immature bone marrow B cells remained largely unchanged, peripheral B cells underwent several changes. Specifically, transitional and mature B cells in the spleen of B6.TCR-Vγ4−/−/6−/− mice and other peripheral B cell populations were diminished, most of all splenic marginal zone (MZ) B cells. However, relative frequencies and absolute numbers of antibody-producing cells, and serum levels of antibodies, IL-4 and BAFF, were increased. Cell transfers confirmed that these changes are directly dependent on the altered γδ T cells in this strain, and their enhanced potential of producing IL-4. Further evidence suggests the possibility of direct interactions between γδ T cells and B cells in the splenic MZ. Together, these data demonstrate the capability of γδ T cells of modulating size and productivity of pre-immune peripheral B cell populations. PMID:26582947

HIV-2 infects resting CD4+ T cells but not monocyte-derived dendritic cells.

PubMed

Chauveau, Lise; Puigdomenech, Isabel; Ayinde, Diana; Roesch, Ferdinand; Porrot, Françoise; Bruni, Daniela; Visseaux, Benoit; Descamps, Diane; Schwartz, Olivier

2015-01-13

Human Immunodeficiency Virus-type 2 (HIV-2) encodes Vpx that degrades SAMHD1, a cellular restriction factor active in non-dividing cells. HIV-2 replicates in lymphocytes but the susceptibility of monocyte-derived dendritic cells (MDDCs) to in vitro infection remains partly characterized. Here, we investigated HIV-2 replication in primary CD4+ T lymphocytes, both activated and non-activated, as well as in MDDCs. We focused on the requirement of Vpx for productive HIV-2 infection, using the reference HIV-2 ROD strain, the proviral clone GL-AN, as well as two primary HIV-2 isolates. All HIV-2 strains tested replicated in activated CD4+ T cells. Unstimulated CD4+ T cells were not productively infected by HIV-2, but viral replication was triggered upon lymphocyte activation in a Vpx-dependent manner. In contrast, MDDCs were poorly infected when exposed to HIV-2. HIV-2 particles did not potently fuse with MDDCs and did not lead to efficient viral DNA synthesis, even in the presence of Vpx. Moreover, the HIV-2 strains tested were not efficiently sensed by MDDCs, as evidenced by a lack of MxA induction upon viral exposure. Virion pseudotyping with VSV-G rescued fusion, productive infection and HIV-2 sensing by MDDCs. Vpx allows the non-productive infection of resting CD4+ T cells, but does not confer HIV-2 with the ability to efficiently infect MDDCs. In these cells, an entry defect prevents viral fusion and reverse transcription independently of SAMHD1. We propose that HIV-2, like HIV-1, does not productively infect MDDCs, possibly to avoid triggering an immune response mediated by these cells.

Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation.

PubMed

Fink, Lisbeth N; Zeuthen, Louise H; Ferlazzo, Guido; Frøkiaer, Hanne

2007-12-01

The intestinal microbiota is essential for homeostasis of the local and systemic immune system, and particularly strains of lactic acid bacteria and Escherichia coli have been shown to have balancing effects on inflammatory conditions such as allergy and inflammatory bowel disease. However, in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production of IL-6 and tumour necrosis factor-alpha to bacteria, which elicited mainly IL-10 in monocyte-derived DC. In contrast, comparable IFN-gamma production patterns were found in both natural killer cells and T cells induced by all bacteria-matured APC. An inhibitory effect of certain strains on this IFN-gamma production was also mediated by all types of APC. The most potent responses were induced by monocyte-derived DC, which thus constitute a sensitive screening model.

Exosomes derived from B16F0 melanoma cells alter the transcriptome of cytotoxic T cells that impacts mitochondrial respiration.

PubMed

Bland, Cassidy L; Byrne-Hoffman, Christina N; Fernandez, Audry; Rellick, Stephanie L; Deng, Wentao; Klinke, David J

2018-03-01

While recent clinical studies demonstrate the promise of cancer immunotherapy, a barrier for broadening the clinical benefit is identifying how tumors locally suppress cytotoxic immunity. As an emerging mode of intercellular communication, exosomes secreted by malignant cells can deliver a complex payload of coding and noncoding RNA to cells within the tumor microenvironment. Here, we quantified the RNA payload within tumor-derived exosomes and the resulting dynamic transcriptomic response to cytotoxic T cells upon exosome delivery to better understand how tumor-derived exosomes can alter immune cell function. Exosomes derived from B16F0 melanoma cells were enriched for a subset of coding and noncoding RNAs that did not reflect the abundance in the parental cell. Upon exosome delivery, RNAseq revealed the dynamic changes in the transcriptome of CTLL2 cytotoxic T cells. In analyzing transiently coexpressed gene clusters, pathway enrichment suggested that the B16F0 exosomal payload altered mitochondrial respiration, which was confirmed independently, and upregulated genes associated with the Notch signaling pathway. Interestingly, exosomal miRNA appeared to have no systematic effect on downregulating target mRNA levels. Gene expression data are available in the GEO database under the accession SuperSeries number GSE102951. © 2018 Federation of European Biochemical Societies.

Peripheral Refraction, Peripheral Eye Length, and Retinal Shape in Myopia.

PubMed

Verkicharla, Pavan K; Suheimat, Marwan; Schmid, Katrina L; Atchison, David A

2016-09-01

To investigate how peripheral refraction and peripheral eye length are related to retinal shape. Relative peripheral refraction (RPR) and relative peripheral eye length (RPEL) were determined in 36 young adults (M +0.75D to -5.25D) along horizontal and vertical visual field meridians out to ±35° and ±30°, respectively. Retinal shape was determined in terms of vertex radius of curvature Rv, asphericity Q, and equivalent radius of curvature REq using a partial coherence interferometry method involving peripheral eye lengths and model eye raytracing. Second-order polynomial fits were applied to RPR and RPEL as functions of visual field position. Linear regressions were determined for the fits' second order coefficients and for retinal shape estimates as functions of central spherical refraction. Linear regressions investigated relationships of RPR and RPEL with retinal shape estimates. Peripheral refraction, peripheral eye lengths, and retinal shapes were significantly affected by meridian and refraction. More positive (hyperopic) relative peripheral refraction, more negative RPELs, and steeper retinas were found along the horizontal than along the vertical meridian and in myopes than in emmetropes. RPR and RPEL, as represented by their second-order fit coefficients, correlated significantly with retinal shape represented by REq. Effects of meridian and refraction on RPR and RPEL patterns are consistent with effects on retinal shape. Patterns derived from one of these predict the others: more positive (hyperopic) RPR predicts more negative RPEL and steeper retinas, more negative RPEL predicts more positive relative peripheral refraction and steeper retinas, and steeper retinas derived from peripheral eye lengths predict more positive RPR.

Impact of Scattering Model on Disdrometer Derived Attenuation Scaling

NASA Technical Reports Server (NTRS)

Zemba, Michael; Luini, Lorenzo; Nessel, James; Riva, Carlo (Compiler)

2016-01-01

NASA Glenn Research Center (GRC), the Air Force Research Laboratory (AFRL), and the Politecnico di Milano (POLIMI) are currently entering the third year of a joint propagation study in Milan, Italy utilizing the 20 and 40 GHz beacons of the Alphasat TDP5 Aldo Paraboni scientific payload. The Ka- and Q-band beacon receivers were installed at the POLIMI campus in June of 2014 and provide direct measurements of signal attenuation at each frequency. Collocated weather instrumentation provides concurrent measurement of atmospheric conditions at the receiver; included among these weather instruments is a Thies Clima Laser Precipitation Monitor (optical disdrometer) which records droplet size distributions (DSD) and droplet velocity distributions (DVD) during precipitation events. This information can be used to derive the specific attenuation at frequencies of interest and thereby scale measured attenuation data from one frequency to another. Given the ability to both predict the 40 GHz attenuation from the disdrometer and the 20 GHz timeseries as well as to directly measure the 40 GHz attenuation with the beacon receiver, the Milan terminal is uniquely able to assess these scaling techniques and refine the methods used to infer attenuation from disdrometer data.In order to derive specific attenuation from the DSD, the forward scattering coefficient must be computed. In previous work, this has been done using the Mie scattering model, however, this assumes a spherical droplet shape. The primary goal of this analysis is to assess the impact of the scattering model and droplet shape on disdrometer derived attenuation predictions by comparing the use of the Mie scattering model to the use of the T-matrix method, which does not assume a spherical droplet. In particular, this paper will investigate the impact of these two scattering approaches on the error of the resulting predictions as well as on the relationship between prediction error and rain rate.

Impact of Scattering Model on Disdrometer Derived Attenuation Scaling

NASA Technical Reports Server (NTRS)

Zemba, Michael; Luini, Lorenzo; Nessel, James; Riva, Carlo

2016-01-01

NASA Glenn Research Center (GRC), the Air Force Research Laboratory (AFRL), and the Politecnico di Milano (POLIMI) are currently entering the third year of a joint propagation study in Milan, Italy utilizing the 20 and 40 GHz beacons of the Alphasat TDP#5 Aldo Paraboni scientific payload. The Ka- and Q-band beacon receivers were installed at the POLIMI campus in June of 2014 and provide direct measurements of signal attenuation at each frequency. Collocated weather instrumentation provides concurrent measurement of atmospheric conditions at the receiver; included among these weather instruments is a Thies Clima Laser Precipitation Monitor (optical disdrometer) which records droplet size distributions (DSD) and droplet velocity distributions (DVD) during precipitation events. This information can be used to derive the specific attenuation at frequencies of interest and thereby scale measured attenuation data from one frequency to another. Given the ability to both predict the 40 gigahertz attenuation from the disdrometer and the 20 gigahertz time-series as well as to directly measure the 40 gigahertz attenuation with the beacon receiver, the Milan terminal is uniquely able to assess these scaling techniques and refine the methods used to infer attenuation from disdrometer data. In order to derive specific attenuation from the DSD, the forward scattering coefficient must be computed. In previous work, this has been done using the Mie scattering model, however, this assumes a spherical droplet shape. The primary goal of this analysis is to assess the impact of the scattering model and droplet shape on disdrometer-derived attenuation predictions by comparing the use of the Mie scattering model to the use of the T-matrix method, which does not assume a spherical droplet. In particular, this paper will investigate the impact of these two scattering approaches on the error of the resulting predictions as well as on the relationship between prediction error and rain rate.

Reversible Shape Memory Polymers and Composites: Synthesis, Modeling and Design

DTIC Science & Technology

2013-03-01

Polymer; and (iii) Development of a Shape Memory Assisted Self - Healing Polymer. Page 3 of 19 Mather/FA9550-09-1-0195 IV(i) Modeling and Model...0195 IV(iii) Development of a Shape Memory Assisted Self - Healing Polymer Erika D. Rodriguez, X. Luo, and P.T. Mather, “Linear and Crosslinked...Poly (ε- Caprolactone) Polymers for Shape Memory Assisted Self - Healing (SMASH),” ACS Applied Materials and Interfaces 3 152-161 (2011). Self

Natural CD8{sup +}25{sup +} regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Yufeng; Zhang, Xueshu; Zhao, Tuo

Highlights: •CD8{sup +}25{sup +} regulatory T cells secrete tolerogenic exosomes. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4{sup +}25{sup +} and CD8{sup +}25{sup +} regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8{sup +}25{sup +} Tr cells from C57BL/6 mouse naive CD8{sup +} T cells, and in vitro amplified them with CD3/CD28 beads. EXOsmore » (EXO{sub Tr}) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXO{sub Tr} had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DC{sub OVA}) plus Tr cells or EXO{sub Tr}, and then assessed OVA-specific CD8{sup +} T cell responses using PE-H-2K{sup b}/OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10{sub OVA} melanoma cells. We demonstrated that DC{sub OVA}-stimulated CD8{sup +} T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p < 0.05), and from 8/8 to 2/8 and 5/8 mice DC{sub OVA} (p < 0.05) in immunized mice with co-injection of Tr cells and EXO{sub Tr}, respectively. Our results indicate that natural CD8{sup +}25{sup +} Tr cell-released EXOs, alike CD8{sup +}25{sup +} Tr cells, can inhibit CD8{sup +} T cell responses and antitumor immunity. Therefore, EXOs

The Calcineurin-NFAT Axis Controls Allograft Immunity in Myeloid-Derived Suppressor Cells through Reprogramming T Cell Differentiation

PubMed Central

Wang, Xiao; Bi, Yujing; Xue, Lixiang; Liao, Jiongbo; Chen, Xi; Lu, Yun; Zhang, Zhengguo; Wang, Jian; Liu, Huanrong; Yang, Hui

2014-01-01

While cyclosporine (CsA) inhibits calcineurin and is highly effective in prolonging rejection for transplantation patients, the immunological mechanisms remain unknown. Herein, the role of calcineurin signaling was investigated in a mouse allogeneic skin transplantation model. The calcineurin inhibitor CsA significantly ameliorated allograft rejection. In CsA-treated allograft recipient mice, CD11b+ Gr1+ myeloid-derived suppressor cells (MDSCs) were functional suppressive immune modulators that resulted in fewer gamma interferon (IFN-γ)-producing CD8+ T cells and CD4+ T cells (TH1 T helper cells) and more interleukin 4 (IL-4)-producing CD4+ T cells (TH2) and prolonged allogeneic skin graft survival. Importantly, the expression of NFATc1 is significantly diminished in the CsA-induced MDSCs. Blocking NFAT (nuclear factor of activated T cells) with VIVIT phenocopied the CsA effects in MDSCs and increased the suppressive activities and recruitment of CD11b+ Gr1+ MDSCs in allograft recipient mice. Mechanistically, CsA treatment enhanced the expression of indoleamine 2,3-dioxygenase (IDO) and the suppressive activities of MDSCs in allograft recipients. Inhibition of IDO nearly completely recovered the increased MDSC suppressive activities and the effects on T cell differentiation. The results of this study indicate that MDSCs are an essential component in controlling allograft survival following CsA or VIVIT treatment, validating the calcineurin-NFAT-IDO signaling axis as a potential therapeutic target in transplantation. PMID:25452304

The Effects of Different Electrode Types for Obtaining Surface Machining Shape on Shape Memory Alloy Using Electrochemical Machining

NASA Astrophysics Data System (ADS)

Choi, S. G.; Kim, S. H.; Choi, W. K.; Moon, G. C.; Lee, E. S.

2017-06-01

Shape memory alloy (SMA) is important material used for the medicine and aerospace industry due to its characteristics called the shape memory effect, which involves the recovery of deformed alloy to its original state through the application of temperature or stress. Consumers in modern society demand stability in parts. Electrochemical machining is one of the methods for obtained these stabilities in parts requirements. These parts of shape memory alloy require fine patterns in some applications. In order to machine a fine pattern, the electrochemical machining method is suitable. For precision electrochemical machining using different shape electrodes, the current density should be controlled precisely. And electrode shape is required for precise electrochemical machining. It is possible to obtain precise square holes on the SMA if the insulation layer controlled the unnecessary current between electrode and workpiece. If it is adjusting the unnecessary current to obtain the desired shape, it will be a great contribution to the medical industry and the aerospace industry. It is possible to process a desired shape to the shape memory alloy by micro controlling the unnecessary current. In case of the square electrode without insulation layer, it derives inexact square holes due to the unnecessary current. The results using the insulated electrode in only side show precise square holes. The removal rate improved in case of insulated electrode than others because insulation layer concentrate the applied current to the machining zone.

Irwin's conjecture: Crack shape adaptability in transversely isotropic solids

NASA Astrophysics Data System (ADS)

Laubie, Hadrien; Ulm, Franz-Josef

2014-08-01

The planar crack propagation problem of a flat elliptical crack embedded in a brittle elastic anisotropic solid is investigated. We introduce the concept of crack shape adaptability: the ability of three-dimensional planar cracks to shape with the mechanical properties of a cracked body. A criterion based on the principle of maximum dissipation is suggested in order to determine the most stable elliptical shape. This criterion is applied to the specific case of vertical cracks in transversely isotropic solids. It is shown that contrary to the isotropic case, the circular shape (i.e. penny-shaped cracks) is not the most stable one. Upon propagation, the crack first grows non-self-similarly before it reaches a stable shape. This stable shape can be approximated by an ellipse of an aspect ratio that varies with the degree of elastic anisotropy. By way of example, we apply the so-derived crack shape adaptability criterion to shale materials. For this class of materials it is shown that once the stable shape is reached, the crack propagates at a higher rate in the horizontal direction than in the vertical direction. We also comment on the possible implications of these findings for hydraulic fracturing operations.

Effector T-cell infiltration positively impacts survival of glioblastoma patients and is impaired by tumor-derived TGF-β.

PubMed

Lohr, Jennifer; Ratliff, Thomas; Huppertz, Andrea; Ge, Yingzi; Dictus, Christine; Ahmadi, Rezvan; Grau, Stefan; Hiraoka, Nobuyoshi; Eckstein, Volker; Ecker, Rupert C; Korff, Thomas; von Deimling, Andreas; Unterberg, Andreas; Beckhove, Philipp; Herold-Mende, Christel

2011-07-01

In glioma-in contrast to various other cancers-the impact of T-lymphocytes on clinical outcome is not clear. We investigated the clinical relevance and regulation of T-cell infiltration in glioma. T-cell subpopulations from entire sections of 93 WHO°II-IV gliomas were computationally identified using markers CD3, CD8, and Foxp3; survival analysis was then done on primary glioblastomas (pGBM). Endothelial cells expressing cellular adhesion molecules (CAM) were similarly computationally quantified from the same glioma tissues. Influence of prominent cytokines (as measured by ELISA from 53 WHO°II-IV glioma lysates) on CAM-expression in GBM-isolated endothelial cells was determined using flow cytometry. The functional relevance of the cytokine-mediated CAM regulation was tested in a transmigration assay using GBM-derived endothelial cells and autologous T-cells. Infiltration of all T-cell subsets increased in high-grade tumors. Most strikingly, within pGBM, elevated numbers of intratumoral effector T cells (T(eff), cytotoxic and helper) significantly correlated with a better survival; regulatory T cells were infrequently present and not associated with GBM patient outcome. Interestingly, increased infiltration of T(eff) cells was related to the expression of ICAM-1 on the vessel surface. Transmigration of autologous T cells in vitro was markedly reduced in the presence of CAM-blocking antibodies. We found that TGF-β molecules impeded transmigration and downregulated CAM-expression on GBM-isolated endothelial cells; blocking TGF-β receptor signaling increased transmigration. This study provides comprehensive and novel insights into occurrence and regulation of T-cell infiltration in glioma. Specifically, targeting TGF-β1 and TGF-β2 might improve intratumoral T-cell infiltration and thus enhance effectiveness of immunotherapeutic approaches.

Shaping Networked Theatre: Experience Architectures, Behaviours and Creative Pedagogies

ERIC Educational Resources Information Center

Sutton, Paul

2012-01-01

Since 2006 the UK based applied theatre company C&T has been using its experience and expertise in mixing drama, learning and digital media to create a new online utility for shaping collaborative educational drama experiences. C&T describes this practice as "Networked Theatre". This article describes both the motivations for…

Continuously differentiable PIC shape functions for triangular meshes

DOE PAGES

Barnes, D. C.

2018-03-21

In this study, a new class of continuously-differentiable shape functions is developed and applied to two-dimensional electrostatic PIC simulation on an unstructured simplex (triangle) mesh. It is shown that troublesome aliasing instabilities are avoided for cold plasma simulation in which the Debye length is as small as 0.01 cell sizes. These new shape functions satisfy all requirements for PIC particle shape. They are non-negative, have compact support, and partition unity. They are given explicitly by cubic expressions in the usual triangle logical (areal) coordinates. The shape functions are not finite elements because their structure depends on the topology of themore » mesh, in particular, the number of triangles neighboring each mesh vertex. Nevertheless, they may be useful as approximations to solution of other problems in which continuity of derivatives is required or desired.« less

Shape-Driven 3D Segmentation Using Spherical Wavelets

PubMed Central

Nain, Delphine; Haker, Steven; Bobick, Aaron; Tannenbaum, Allen

2013-01-01

This paper presents a novel active surface segmentation algorithm using a multiscale shape representation and prior. We define a parametric model of a surface using spherical wavelet functions and learn a prior probability distribution over the wavelet coefficients to model shape variations at different scales and spatial locations in a training set. Based on this representation, we derive a parametric active surface evolution using the multiscale prior coefficients as parameters for our optimization procedure to naturally include the prior in the segmentation framework. Additionally, the optimization method can be applied in a coarse-to-fine manner. We apply our algorithm to the segmentation of brain caudate nucleus, of interest in the study of schizophrenia. Our validation shows our algorithm is computationally efficient and outperforms the Active Shape Model algorithm by capturing finer shape details. PMID:17354875

Continuously differentiable PIC shape functions for triangular meshes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnes, D. C.

In this study, a new class of continuously-differentiable shape functions is developed and applied to two-dimensional electrostatic PIC simulation on an unstructured simplex (triangle) mesh. It is shown that troublesome aliasing instabilities are avoided for cold plasma simulation in which the Debye length is as small as 0.01 cell sizes. These new shape functions satisfy all requirements for PIC particle shape. They are non-negative, have compact support, and partition unity. They are given explicitly by cubic expressions in the usual triangle logical (areal) coordinates. The shape functions are not finite elements because their structure depends on the topology of themore » mesh, in particular, the number of triangles neighboring each mesh vertex. Nevertheless, they may be useful as approximations to solution of other problems in which continuity of derivatives is required or desired.« less

Rotational spectrum and structure of the T-shaped cyanoacetylene carbon dioxide complex, HCCCN⋯CO2

NASA Astrophysics Data System (ADS)

Kang, Lu; Davis, Philip; Dorell, Ian; Li, Kexin; Oncer, Onur; Wang, Lucy; Novick, Stewart E.; Kukolich, Stephen G.

2017-12-01

The rotational spectrum of the T-shaped cyanoacetylene carbon dioxide dimer, HCCCN⋯CO2, was measured using two Balle-Flygare Fourier transform microwave (FTMW) spectrometers between 1.4 GHz and 25 GHz. Only the Ka = 0, 2, 4 branches of spectrum from J‧ = 1 ← 0 to J″ = 16 ← 15 transitions were observed. The vanishing of the Ka = 1, 3, … transitions demonstrates a C2v symmetry complex with a T-shaped alignment of the subunits. The spectroscopic constants were fit using Pickett's SPFIT/SPCAT suite of programs obtaining: A0 = 11273(18) MHz, B0 = 764.088(21) MHz, C0 = 716.254(21) MHz, ΔJ = 0.50329(34) kHz, ΔJK = 0.120867(11) MHz, ΔK = -28.17(36) MHz, δJ = 0.0613(21) kHz, δK = 44.25(95) kHz, ΦJ = 0.0053(12) Hz, ΦJK = 9.820(55) Hz, ΦKJ = -0.59325(72) kHz, ΦK = -2.3719(53) MHz, ϕJ = 0.0398(42) Hz, ϕJK = 6.9(9) Hz, and ϕK = -3.592(13) kHz. The 14N nuclear quadrupole coupling constants were fit to χaa = -4.12753(38) MHz and χbb - χcc = 0.103(15) MHz. The small negative inertial defect, Δ0 = -0.66(12) u Å2, indicates a vibrationally averaged planar complex with non-negligible low frequency out-of-plane vibrations. While maintaining near-planar orientation, both binding partners exhibit large-amplitude bending vibrations within the plane. To deal with the intermolecular dynamics, a torsional oscillation model was developed in this work for the structural analysis. According to this model, the vibrational bending amplitude for HCCCN torsional angle is 10.(1)°, with the a-axis of complex; CO2 subtending a 5.4(5)° torsional oscillation angle with the b molecular axis. The van der Waals bond length is 3.0137(3) Å. The stretching force constant, ks = 3.9 N/m, and the stretching frequency, νs = 53 cm-1, for the van der Waals bond were calculated using the pseudo-diatomic model. High-level MP2 and DFT calculations of structural parameters, rotational constants, and 14N quadrupole coupling strengths were made and the results compared with

Impact of C-rel inhibition of cord blood-derived B-, T-, and NK cells.

PubMed

Fallahi, Shirin; Mohammadi, Seyede Momeneh; Tayefi Nasrabadi, Hamid; Alihemmati, Alireza; Samadi, Naser; Gholami, Sanaz; Shanehbandi, Dariush; Nozad Charoudeh, Hojjatollah

2017-12-01

The c-Rel transcription factor is a unique member of the nuclear factor (NF)-κB family that has a role in curtailing the proliferation, differentiation, cytokine production, and overall activity of B- and T-cells. In addition, c-Rel is a key regulator of apoptosis in that it influences the expression of anti-apoptotic genes such as Bcl-2 and Bcl-xL; conversely, inhibition of c-Rel increases cell apoptosis. To better understand the relationship between c-Rel expression and effects on B- and T-cell expansion, the current study evaluated c-Rel expression in cord blood mononuclear cells. This particular source was selected as cord blood is an important source of cells used for transplantation and immunotherapy, primarily in treating leukemias. As stem cell factor (SCF) and FLT3 are important agents for hematopoietic stem cell expansion, and cytokines like interleukin (IL)-2, -7, and -15 are essential for T- and B- (and also NK) cell development and proliferation, the current study evaluated c-Rel expression in cord blood mononuclear cells and CD34 +  cells, as well as effects on B-, T-, and NK cells associated with alterations in c-Rel expression, using flow cytometry and PCR. The results showed c-Rel expression increased among cells cultured in the presence of SCF and FLT3 but was reduced when IL-2, IL-7, and IL-15 were used all together. Further, inhibition of c-Rel expression by siRNA reduced cord blood-derived B-, T-, and NK cell differentiation and expansion. These results indicated that with cells isolated from cord blood, c-Rel has an important role in B-, T-, and NK cell differentiation and, further, that agents (select cytokines/growth factors) that could impact on its expression might not only affect immune cell profiles in a host but could potentially also limit apoptotic activities in (non-)immune cells in that host. In the context of cancer (immuno)therapy, in particular, when cord blood is used an important source in stem cell transplantation in

A few shape optimization results for a biharmonic Steklov problem

NASA Astrophysics Data System (ADS)

Buoso, Davide; Provenzano, Luigi

2015-09-01

We derive the equation of a free vibrating thin plate whose mass is concentrated at the boundary, namely a Steklov problem for the biharmonic operator. We provide Hadamard-type formulas for the shape derivatives of the corresponding eigenvalues and prove that balls are critical domains under volume constraint. Finally, we prove an isoperimetric inequality for the first positive eigenvalue.

Pervasive genetic integration directs the evolution of human skull shape.

PubMed

Martínez-Abadías, Neus; Esparza, Mireia; Sjøvold, Torstein; González-José, Rolando; Santos, Mauro; Hernández, Miquel; Klingenberg, Christian Peter

2012-04-01

It has long been unclear whether the different derived cranial traits of modern humans evolved independently in response to separate selection pressures or whether they resulted from the inherent morphological integration throughout the skull. In a novel approach to this issue, we combine evolutionary quantitative genetics and geometric morphometrics to analyze genetic and phenotypic integration in human skull shape. We measured human skulls in the ossuary of Hallstatt (Austria), which offer a unique opportunity because they are associated with genealogical data. Our results indicate pronounced covariation of traits throughout the skull. Separate simulations of selection for localized shape changes corresponding to some of the principal derived characters of modern human skulls produced outcomes that were similar to each other and involved a joint response in all of these traits. The data for both genetic and phenotypic shape variation were not consistent with the hypothesis that the face, cranial base, and cranial vault are completely independent modules but relatively strongly integrated structures. These results indicate pervasive integration in the human skull and suggest a reinterpretation of the selective scenario for human evolution where the origin of any one of the derived characters may have facilitated the evolution of the others. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Synthesis and characterization of star-shaped oligo(ethylene glycol) with tyrosine derived moieties under variation of their molecular weight.

PubMed

Julich-Gruner, Konstanze K; Roch, Toralf; Ma, Nan; Neffe, Axel T; Lendlein, Andreas

2015-01-01

Desamino tyrosine (DAT) and desamino tyrosyl tyrosine (DATT) can be used to functionalize the end groups of water soluble polymers. The phenolic groups may enable physical interactions by π- π interaction and hydrogen bonds, which might lead to the formation of a hydrogel by physical crosslinking. However, using star-shaped oligo(ethylene glycols) (sOEG) with a molecular weight of 5 kDa for functionalization with DAT or DATT resulted in the formation of surfactants and not in hydrogels.As the molecular weight of the sOEG polymer chain can have an influence on forming physical cross links, DAT(T)-fuctionalization of sOEGs with higher molecular weight was investigated, the polymers were structurally characterized and for their mechanical properties were evaluated by rheological measurements.Aqueous solutions of DAT(T)-sOEGs with 10 and 20 kDa showed lower storage and loss moduli compared to unfunctionalized sOEGs indicating also the formation of surfactants. Cell-based assays showed that all sOEG solutions did not impair cell viability and were free of endotoxins, which could otherwise induce uncontrolled immune responses.Conclusively, our data suggested that the sOEG solutions have surface active properties without inducing unwanted cellular responses, which is required e.g. in pharmaceutical applications to solubilize hydophobic substances.

Method and apparatus for shape and end position determination using an optical fiber

NASA Technical Reports Server (NTRS)

Moore, Jason P. (Inventor)

2010-01-01

A method of determining the shape of an unbound optical fiber includes collecting strain data along a length of the fiber, calculating curvature and bending direction data of the fiber using the strain data, curve-fitting the curvature and bending direction data to derive curvature and bending direction functions, calculating a torsion function using the bending direction function, and determining the 3D shape from the curvature, bending direction, and torsion functions. An apparatus for determining the 3D shape of the fiber includes a fiber optic cable unbound with respect to a protective sleeve, strain sensors positioned along the cable, and a controller in communication with the sensors. The controller has an algorithm for determining a 3D shape and end position of the fiber by calculating a set of curvature and bending direction data, deriving curvature, bending, and torsion functions, and solving Frenet-Serret equations using these functions.

Donor-derived CD19-targeted T cells cause regression of malignancy persisting after allogeneic hematopoietic stem cell transplantation.

PubMed

Kochenderfer, James N; Dudley, Mark E; Carpenter, Robert O; Kassim, Sadik H; Rose, Jeremy J; Telford, William G; Hakim, Frances T; Halverson, David C; Fowler, Daniel H; Hardy, Nancy M; Mato, Anthony R; Hickstein, Dennis D; Gea-Banacloche, Juan C; Pavletic, Steven Z; Sportes, Claude; Maric, Irina; Feldman, Steven A; Hansen, Brenna G; Wilder, Jennifer S; Blacklock-Schuver, Bazetta; Jena, Bipulendu; Bishop, Michael R; Gress, Ronald E; Rosenberg, Steven A

2013-12-12

New treatments are needed for B-cell malignancies persisting after allogeneic hematopoietic stem cell transplantation (alloHSCT). We conducted a clinical trial of allogeneic T cells genetically modified to express a chimeric antigen receptor (CAR) targeting the B-cell antigen CD19. T cells for genetic modification were obtained from each patient's alloHSCT donor. All patients had malignancy that persisted after alloHSCT and standard donor lymphocyte infusions (DLIs). Patients did not receive chemotherapy prior to the CAR T-cell infusions and were not lymphocyte depleted at the time of the infusions. The 10 treated patients received a single infusion of allogeneic anti-CD19-CAR T cells. Three patients had regressions of their malignancies. One patient with chronic lymphocytic leukemia (CLL) obtained an ongoing complete remission after treatment with allogeneic anti-CD19-CAR T cells, another CLL patient had tumor lysis syndrome as his leukemia dramatically regressed, and a patient with mantle cell lymphoma obtained an ongoing partial remission. None of the 10 patients developed graft-versus-host disease (GVHD). Toxicities included transient hypotension and fever. We detected cells containing the anti-CD19-CAR gene in the blood of 8 of 10 patients. These results show for the first time that donor-derived allogeneic anti-CD19-CAR T cells can cause regression of B-cell malignancies resistant to standard DLIs without causing GVHD.

Appearances Aren't Everything: Shape Classifiers and Referential Processing in Cantonese

ERIC Educational Resources Information Center

Tsang, Cara; Chambers, Craig G.

2011-01-01

Cantonese shape classifiers encode perceptual information that is characteristic of their associated nouns, although certain nouns are exceptional. For example, the classifier "tiu" occurs primarily with nouns for long-narrow-flexible objects (e.g., scarves, snakes, and ropes) and also occurs with the noun for a (short, rigid) key. In 3…

On the shape of martian dust and water ice aerosols

NASA Astrophysics Data System (ADS)

Pitman, K. M.; Wolff, M. J.; Clancy, R. T.; Clayton, G. C.

2000-10-01

Researchers have often calculated radiative properties of Martian aerosols using either Mie theory for homogeneous spheres or semi-empirical theories. Given that these atmospheric particles are randomly oriented, this approach seems fairly reasonable. However, the idea that randomly oriented nonspherical particles have scattering properties equivalent to even a select subset of spheres is demonstratably false} (Bohren and Huffman 1983; Bohren and Koh 1985, Appl. Optics, 24, 1023). Fortunately, recent computational developments now enable us to directly compute scattering properties for nonspherical particles. We have combined a numerical approach for axisymmetric particle shapes, i.e., cylinders, disks, spheroids (Waterman's T-Matrix approach as improved by Mishchenko and collaborators; cf., Mishchenko et al. 1997, JGR, 102, D14, 16,831), with a multiple-scattering radiative transfer algorithm to constrain the shape of water ice and dust aerosols. We utilize a two-stage iterative process. First, we empirically derive a scattering phase function for each aerosol component (starting with some ``guess'') from radiative transfer models of MGS Thermal Emission Spectrometer Emission Phase Function (EPF) sequences (for details on this step, see Clancy et al., DPS 2000). Next, we perform a series of scattering calculations, adjusting our parameters to arrive at a ``best-fit'' theoretical phase function. In this presentation, we provide details on the second step in our analysis, including the derived phase functions (for several characteristic EPF sequences) as well as the particle properties of the best-fit theoretical models. We provide a sensitivity analysis for the EPF model-data comparisons in terms of perturbations in the particle properties (i.e., range of axial ratios, sizes, refractive indices, etc). This work is supported through NASA grant NAGS-9820 (MJW) and JPL contract no. 961471 (RTC).

A Novel Shape Parameterization Approach

NASA Technical Reports Server (NTRS)

Samareh, Jamshid A.

1999-01-01

This paper presents a novel parameterization approach for complex shapes suitable for a multidisciplinary design optimization application. The approach consists of two basic concepts: (1) parameterizing the shape perturbations rather than the geometry itself and (2) performing the shape deformation by means of the soft objects animation algorithms used in computer graphics. Because the formulation presented in this paper is independent of grid topology, we can treat computational fluid dynamics and finite element grids in a similar manner. The proposed approach is simple, compact, and efficient. Also, the analytical sensitivity derivatives are easily computed for use in a gradient-based optimization. This algorithm is suitable for low-fidelity (e.g., linear aerodynamics and equivalent laminated plate structures) and high-fidelity analysis tools (e.g., nonlinear computational fluid dynamics and detailed finite element modeling). This paper contains the implementation details of parameterizing for planform, twist, dihedral, thickness, and camber. The results are presented for a multidisciplinary design optimization application consisting of nonlinear computational fluid dynamics, detailed computational structural mechanics, performance, and a simple propulsion module.

Genetic Incorporation of Twelve meta-Substituted Phenylalanine Derivatives Using A Single Pyrrolysyl-tRNA Synthetase

PubMed Central

Wang, Yane-Shih; Fang, Xinqiang; Chen, Hsueh-Ying; Wu, Bo; Wang, Zhiyong U.; Hilty, Christian; Liu, Wenshe R.

2012-01-01

When coexpressed with its cognate amber suppressing tRNACUAPyl, a pyrrolysyl-tRNA synthetase mutant N346A/C348A is able to genetically incorporate twelve meta-substituted phenylalanine derivatives into proteins site-specifically at amber mutation sites in Escherichia coli. These genetically encoded noncanonical amino acids resemble phenylalanine in size and contain diverse bioorthogonal functional groups such as halide, trifluoromethyl, nitrile, nitro, ketone, alkyne, and azide moieties. The genetic installation of these functional groups in proteins provides multiple ways to site-selectively label proteins with biophysical and biochemical probes for their functional investigations. We demonstrate that a genetically incorporated trifluoromethyl group can be used as a sensitive 19F NMR probe to study protein folding/unfolding, and that genetically incorporated reactive functional groups such as ketone, alkyne, and azide moieties can be applied to site-specifically label proteins with florescent probes. This critical discovery allows the synthesis of proteins with diverse bioorthogonal functional groups for a variety of basic studies and biotechnology development using a single recombinant expression system. PMID:23138887

Inverse Diffusion Curves Using Shape Optimization.

PubMed

Zhao, Shuang; Durand, Fredo; Zheng, Changxi

2018-07-01

The inverse diffusion curve problem focuses on automatic creation of diffusion curve images that resemble user provided color fields. This problem is challenging since the 1D curves have a nonlinear and global impact on resulting color fields via a partial differential equation (PDE). We introduce a new approach complementary to previous methods by optimizing curve geometry. In particular, we propose a novel iterative algorithm based on the theory of shape derivatives. The resulting diffusion curves are clean and well-shaped, and the final image closely approximates the input. Our method provides a user-controlled parameter to regularize curve complexity, and generalizes to handle input color fields represented in a variety of formats.

Development of the Shaping-lathe Headrig

Treesearch

Peter Koch

1974-01-01

The drawing on the opposite page depicts the commercial version of the Koch shaping-lathe headrig. This first production model, design of which is based on data derived from prototype trials described in the present paper, will be commercially making southern hardwood flakes and pallet cants by early spring of 1975. It carries a 54-inch-long, six-knife cutterhead with...

Immunosuppressive Activity of Daphnetin, One of Coumarin Derivatives, Is Mediated through Suppression of NF-κB and NFAT Signaling Pathways in Mouse T Cells

PubMed Central

Liu, Yan; Xu, Sisi; Huang, Guoren; Xiong, Ying; Zhang, Shuang; Xu, Linli; Deng, Xuming; Guan, Shuang

2014-01-01

Daphnetin, a plant-derived dihydroxylated derivative of coumarin, is an effective compound extracted from a plant called Daphne Korean Nakai. Coumarin derivates were known for their antithrombotic, anti-inflammatory, and antioxidant activities. The present study was aimed to determine the immunosuppressive effects and the underlying mechanisms of daphnetin on concanavalin A (ConA) induced T lymphocytes in mice. We showed that, in vitro, daphnetin suppressed ConA-induced splenocyte proliferation, influenced production of the cytokines and inhibited cell cycle progression through the G0/G1 transition. The data also revealed that daphnetin could down-regulate activation of ConA induced NF-κB and NFAT signal transduction pathways in mouse T lymphocyte. In vivo, daphnetin treatment significantly inhibited the 2, 4- dinitrofluorobenzene (DNFB) -induced delayed type hypersensitivity (DTH) reactions in mice. Collectively, daphnetin had strong immunosuppressive activity both in vitro and in vivo, suggesting a potential role for daphnetin as an immunosuppressive agent, and established the groundwork for further research on daphnetin. PMID:24800925

Swimming motion of rod-shaped magnetotactic bacteria: the effects of shape and growing magnetic moment

PubMed Central

Kong, Dali; Lin, Wei; Pan, Yongxin; Zhang, Keke

2014-01-01

We investigate the swimming motion of rod-shaped magnetotactic bacteria affiliated with the Nitrospirae phylum in a viscous liquid under the influence of an externally imposed, time-dependent magnetic field. By assuming that fluid motion driven by the translation and rotation of a swimming bacterium is of the Stokes type and that inertial effects of the motion are negligible, we derive a new system of the twelve coupled equations that govern both the motion and orientation of a swimming rod-shaped magnetotactic bacterium with a growing magnetic moment in the laboratory frame of reference. It is revealed that the initial pattern of swimming motion can be strongly affected by the rate of the growing magnetic moment. It is also revealed, through comparing mathematical solutions of the twelve coupled equations to the swimming motion observed in our laboratory experiments with rod-shaped magnetotactic bacteria, that the laboratory trajectories of the swimming motion can be approximately reproduced using an appropriate set of the parameters in our theoretical model. PMID:24523716

The role of parasite-driven selection in shaping landscape genomic structure in red grouse (Lagopus lagopus scotica).

PubMed

Wenzel, Marius A; Douglas, Alex; James, Marianne C; Redpath, Steve M; Piertney, Stuart B

2016-01-01

Landscape genomics promises to provide novel insights into how neutral and adaptive processes shape genome-wide variation within and among populations. However, there has been little emphasis on examining whether individual-based phenotype-genotype relationships derived from approaches such as genome-wide association (GWAS) manifest themselves as a population-level signature of selection in a landscape context. The two may prove irreconcilable as individual-level patterns become diluted by high levels of gene flow and complex phenotypic or environmental heterogeneity. We illustrate this issue with a case study that examines the role of the highly prevalent gastrointestinal nematode Trichostrongylus tenuis in shaping genomic signatures of selection in red grouse (Lagopus lagopus scotica). Individual-level GWAS involving 384 SNPs has previously identified five SNPs that explain variation in T. tenuis burden. Here, we examine whether these same SNPs display population-level relationships between T. tenuis burden and genetic structure across a small-scale landscape of 21 sites with heterogeneous parasite pressure. Moreover, we identify adaptive SNPs showing signatures of directional selection using F(ST) outlier analysis and relate population- and individual-level patterns of multilocus neutral and adaptive genetic structure to T. tenuis burden. The five candidate SNPs for parasite-driven selection were neither associated with T. tenuis burden on a population level, nor under directional selection. Similarly, there was no evidence of parasite-driven selection in SNPs identified as candidates for directional selection. We discuss these results in the context of red grouse ecology and highlight the broader consequences for the utility of landscape genomics approaches for identifying signatures of selection. © 2015 John Wiley & Sons Ltd.

Stimuli-Responsive, Shape-Transforming Nanostructured Particles.

PubMed

Lee, Junhyuk; Ku, Kang Hee; Kim, Mingoo; Shin, Jae Man; Han, Junghun; Park, Chan Ho; Yi, Gi-Ra; Jang, Se Gyu; Kim, Bumjoon J

2017-08-01

Development of particles that change shape in response to external stimuli has been a long-thought goal for producing bioinspired, smart materials. Herein, the temperature-driven transformation of the shape and morphology of polymer particles composed of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) block copolymers (BCPs) and temperature-responsive poly(N-isopropylacrylamide) (PNIPAM) surfactants is reported. PNIPAM acts as a temperature-responsive surfactant with two important roles. First, PNIPAM stabilizes oil-in-water droplets as a P4VP-selective surfactant, creating a nearly neutral interface between the PS and P4VP domains together with cetyltrimethylammonium bromide, a PS-selective surfactant, to form anisotropic PS-b-P4VP particles (i.e., convex lenses and ellipsoids). More importantly, the temperature-directed positioning of PNIPAM depending on its solubility determines the overall particle shape. Ellipsoidal particles are produced above the critical temperature, whereas convex lens-shaped particles are obtained below the critical temperature. Interestingly, given that the temperature at which particle shape change occurs depends solely on the lower critical solution temperature (LCST) of the polymer surfactants, facile tuning of the transition temperature is realized by employing other PNIPAM derivatives with different LCSTs. Furthermore, reversible transformations between different shapes of PS-b-P4VP particles are successfully demonstrated using a solvent-adsorption annealing with chloroform, suggesting great promise of these particles for sensing, smart coating, and drug delivery applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phase 1 studies of central memory-derived CD19 CAR T-cell therapy following autologous HSCT in patients with B-cell NHL.

PubMed

Wang, Xiuli; Popplewell, Leslie L; Wagner, Jamie R; Naranjo, Araceli; Blanchard, M Suzette; Mott, Michelle R; Norris, Adam P; Wong, ChingLam W; Urak, Ryan Z; Chang, Wen-Chung; Khaled, Samer K; Siddiqi, Tanya; Budde, Lihua E; Xu, Jingying; Chang, Brenda; Gidwaney, Nikita; Thomas, Sandra H; Cooper, Laurence J N; Riddell, Stanley R; Brown, Christine E; Jensen, Michael C; Forman, Stephen J

2016-06-16

Myeloablative autologous hematopoietic stem cell transplantation (HSCT) is a mainstay of therapy for relapsed intermediate-grade B-cell non-Hodgkin lymphoma (NHL); however, relapse rates are high. In phase 1 studies designed to improve long-term remission rates, we administered adoptive T-cell immunotherapy after HSCT, using ex vivo-expanded autologous central memory-enriched T cells (TCM) transduced with lentivirus expressing CD19-specific chimeric antigen receptors (CARs). We present results from 2 safety/feasibility studies, NHL1 and NHL2, investigating different T-cell populations and CAR constructs. Engineered TCM-derived CD19 CAR T cells were infused 2 days after HSCT at doses of 25 to 200 × 10(6) in a single infusion. In NHL1, 8 patients safely received T-cell products engineered from enriched CD8(+) TCM subsets, expressing a first-generation CD19 CAR containing only the CD3ζ endodomain (CD19R:ζ). Four of 8 patients (50%; 95% confidence interval [CI]: 16-84%) were progression free at both 1 and 2 years. In NHL2, 8 patients safely received T-cell products engineered from enriched CD4(+) and CD8(+) TCM subsets and expressing a second-generation CD19 CAR containing the CD28 and CD3ζ endodomains (CD19R:28ζ). Six of 8 patients (75%; 95% CI: 35-97%) were progression free at 1 year. The CD4(+)/CD8(+) TCM-derived CD19 CAR T cells (NHL2) exhibited improvement in expansion; however, persistence was ≤28 days, similar to that seen by others using CD28 CARs. Neither cytokine release syndrome nor delayed hematopoietic engraftment was observed in either trial. These data demonstrate the safety and feasibility of CD19 CAR TCM therapy after HSCT. Trials were registered at www.clinicaltrials.gov as #NCT01318317 and #NCT01815749. © 2016 by The American Society of Hematology.

Feasibility of sealed D-T neutron generator as neutron source for liver BNCT and its beam shaping assembly.

PubMed

Liu, Zheng; Li, Gang; Liu, Linmao

2014-04-01

This paper involves the feasibility of boron neutron capture therapy (BNCT) for liver tumor with four sealed neutron generators as neutron source. Two generators are placed on each side of the liver. The high energy of these emitted neutrons should be reduced by designing a beam shaping assembly (BSA) to make them useable for BNCT. However, the neutron flux decreases as neutrons pass through different materials of BSA. Therefore, it is essential to find ways to increase the neutron flux. In this paper, the feasibility of using low enrichment uranium as a neutron multiplier is investigated to increase the number of neutrons emitted from D-T neutron generators. The neutron spectrum related to our system has a proper epithermal flux, and the fast and thermal neutron fluxes comply with the IAEA recommended values. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reciprocal relationship of T regulatory cells and monocytic myeloid-derived suppressor cells in LP-BM5 murine retrovirus-induced immunodeficiency.

PubMed

O'Connor, Megan A; Vella, Jennifer L; Green, William R

2016-02-01

Immunomodulatory cellular subsets, including myeloid-derived suppressor cells (MDSCs) and T regulatory cells (Tregs), contribute to the immunosuppressive tumour microenvironment and are targets of immunotherapy, but their role in retroviral-associated immunosuppression is less well understood. Due to known crosstalk between Tregs and MDSCs in the tumour microenvironment, and also their hypothesized involvement during human immunodeficiency virus/simian immunodeficiency virus infection, studying the interplay between these immune cells during LP-BM5 retrovirus-induced murine AIDS is of interest. IL-10-producing FoxP3+ Tregs expanded after LP-BM5 infection. Following in vivo adoptive transfer of natural Treg (nTreg)-depleted CD4+T-cells, and subsequent LP-BM5 retroviral infection, enriched monocytic MDSCs (M-MDSCs) from these nTreg-depleted mice displayed altered phenotypic subsets. In addition, M-MDSCs from LP-BM5-infected nTreg-depleted mice exhibited increased suppression of T-cell, but not B-cell, responses, compared with M-MDSCs derived from non-depleted LP-BM5-infected controls. Additionally, LP-BM5-induced M-MDSCs modulated the production of IL-10 by FoxP3+ Tregs in vitro. These collective data highlight in vitro and for the first time, to the best of our knowledge, in vivo reciprocal modulation between retroviral-induced M-MDSCs and Tregs, and may provide insight into the immunotherapeutic targeting of such regulatory cells during retroviral infection.

Cancer cell-derived IL-1α induces CCL22 and the recruitment of regulatory T cells

PubMed Central

Wiedemann, Gabriela Maria; Knott, Max Martin Ludwig; Vetter, Viola Katharina; Rapp, Moritz; Haubner, Sascha; Fesseler, Julia; Kühnemuth, Benjamin; Layritz, Patrick; Thaler, Raffael; Kruger, Stephan; Ormanns, Steffen; Mayr, Doris; Endres, Stefan; Anz, David

2016-01-01

ABSTRACT In cancer patients, immunosuppression through regulatory T cells (Treg) is a crucial component of tumor immune evasion and contributes to disease progression. Tumor-infiltrating Treg in particular suppress local effector T cell responses and are associated with poor prognosis in tumors such as human pancreatic cancer or hepatocellular carcinoma (HCC). The chemokine CCL22 is known to recruit Treg into the tumor tissue and many types of human tumors are known to express high levels of CCL22. The mechanisms leading to intratumoral secretion of CCL22 are so far unknown. We demonstrate here that intratumoral CCL22 is induced in tumor-infiltrating immune cells through cancer cell-derived interleukin-1 (IL-1α). In pancreatic cancer and HCC, CCL22 is produced by intratumoral dendritic cells, while the cancer cells themselves do not secrete CCL22 in vitro and in vivo. Incubation of human peripheral blood mononuclear cells (PBMC) or murine splenocytes with tumor cells or tumor cell supernatants strongly induced CCL22 secretion in vitro. Tumor cell supernatants contained IL-1 and CCL22 induction in PBMC could be specifically prevented by the IL-1 receptor antagonist anakinra or by transfection of tumor cell lines with IL-1 siRNA, leading to a suppression of Treg migration. In conclusion, we identify here tumor cell-derived IL-1α as a major inducer of the Treg attracting chemokine CCL22 in human cancer cells. Therapeutic blockade of the IL-1 pathway could represent a promising strategy to inhibit tumor-induced immunosuppression. PMID:27757295

Brownian motion of a particle with arbitrary shape.

PubMed

Cichocki, Bogdan; Ekiel-Jeżewska, Maria L; Wajnryb, Eligiusz

2015-06-07

Brownian motion of a particle with an arbitrary shape is investigated theoretically. Analytical expressions for the time-dependent cross-correlations of the Brownian translational and rotational displacements are derived from the Smoluchowski equation. The role of the particle mobility center is determined and discussed.

Solute transport by flow yields geometric shocks in shape evolution

NASA Astrophysics Data System (ADS)

Huang, Jinzi (Mac); Davies Wykes, Megan; Hajjar, George; Ristroph, Leif; Shelley, Michael

2017-11-01

Geological processes such as erosion and dissolution of surfaces often lead to striking shapes with strikingly sharp features. We present observations of such features forming in dissolution under gravity. In our experiment, a dissolving body with initially smooth surface evolves into an increasingly sharp needle shape. A mathematical model of its shape dynamics, derived from a boundary layer theory, predicts that a geometric shock forms at the tip of dissolved body, with the tip curvature becoming infinite in finite time. We further discuss the model's application to similar processes, such as flow driven erosion which can yield corners.

Derivation of the Johnson-Samwer T2/3 temperature dependence of the yield strain in metallic glasses

NASA Astrophysics Data System (ADS)

Dasgupta, Ratul; Joy, Ashwin; Hentschel, H. G. E.; Procaccia, Itamar

2013-01-01

Metallic glasses are prone to fail mechanically via a shear-banding instability. In a remarkable paper Johnson and Samwer demonstrated that this failure enjoys a high degree of universality in the sense that a large group of metallic glasses appears to possess a yield strain that decreases with temperature following a -T2/3 law up to logarithmic corrections. In this Rapid Communication we offer a theoretical derivation of this law. We show that our formula fits very well simulation data on typical amorphous solids.

A Difference Scheme with Autocontrol Artificial Viscosity to Predict Ablated Nosetip Shape

DTIC Science & Technology

1989-09-29

I FTD-ID(RS)T-0640-89 U) (0 FOREIGN TECHNOLOGY DIVISION A DIFFERENCE SCHEME WITH AUTOCONTROL ARTIFICIAL VISCOSITY TO PREDICT ABLATED NOSETIP SHAPE by...September 1989 MICROFICHE NR: FTD-89-C-000800 A DIFFERENCE SCHEME WITH AUTOCONTROL ARTIFICIAL VISCOSITY TO PREDICT ABLATED NOSETIP SHAPE By: Yang Maozhao...DIFFERENCE SCHEME WITH AUTOCONTROL ARTIFICIAL VISCOSITY TO PREDICT ABLATED NOSETIP SHAPE Yang Maozhao (China Aerodynamic Research and Development Centre

T cell-derived IL-10 and its impact on the regulation of host responses during malaria.

PubMed

Freitas do Rosario, Ana Paula; Langhorne, Jean

2012-05-15

Despite intense research, malaria still is the one of the most devastating diseases killing more people than any other parasitic infection. In an attempt to control the infection, the host immune system produces a potent pro-inflammatory response. However, this response is also associated with complications, such as severe anaemia, hypoglycaemia and cerebral malaria. This pronounced production of pro-inflammatory cytokines response is a common feature of malaria caused by parasites infecting humans as well as rodents and primates. A balance between pro- and anti-inflammatory responses may be fundamental to the elimination of the parasite without inducing excessive host pathology. IL-10 is a key cytokine that has been shown to have an important regulatory function in establishing this balance in malaria. Here we discuss which cells can produce IL-10 during infection, and present an overview of the evidence showing that T-cell derived IL-10 plays an important role in regulating malaria pathology. Many different subsets of T cells can produce IL-10, however, evidence is accumulating that it is effector Th1 CD4(+) T cells which provide the crucial source that down-regulates inflammatory pathology during blood-stage malaria infections. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Improvement and Extension of Shape Evaluation Criteria in Multi-Scale Image Segmentation

NASA Astrophysics Data System (ADS)

Sakamoto, M.; Honda, Y.; Kondo, A.

2016-06-01

From the last decade, the multi-scale image segmentation is getting a particular interest and practically being used for object-based image analysis. In this study, we have addressed the issues on multi-scale image segmentation, especially, in improving the performances for validity of merging and variety of derived region's shape. Firstly, we have introduced constraints on the application of spectral criterion which could suppress excessive merging between dissimilar regions. Secondly, we have extended the evaluation for smoothness criterion by modifying the definition on the extent of the object, which was brought for controlling the shape's diversity. Thirdly, we have developed new shape criterion called aspect ratio. This criterion helps to improve the reproducibility on the shape of object to be matched to the actual objectives of interest. This criterion provides constraint on the aspect ratio in the bounding box of object by keeping properties controlled with conventional shape criteria. These improvements and extensions lead to more accurate, flexible, and diverse segmentation results according to the shape characteristics of the target of interest. Furthermore, we also investigated a technique for quantitative and automatic parameterization in multi-scale image segmentation. This approach is achieved by comparing segmentation result with training area specified in advance by considering the maximization of the average area in derived objects or satisfying the evaluation index called F-measure. Thus, it has been possible to automate the parameterization that suited the objectives especially in the view point of shape's reproducibility.

Donor-derived CD19-targeted T cells cause regression of malignancy persisting after allogeneic hematopoietic stem cell transplantation

PubMed Central

Dudley, Mark E.; Carpenter, Robert O.; Kassim, Sadik H.; Rose, Jeremy J.; Telford, William G.; Hakim, Frances T.; Halverson, David C.; Fowler, Daniel H.; Hardy, Nancy M.; Mato, Anthony R.; Hickstein, Dennis D.; Gea-Banacloche, Juan C.; Pavletic, Steven Z.; Sportes, Claude; Maric, Irina; Feldman, Steven A.; Hansen, Brenna G.; Wilder, Jennifer S.; Blacklock-Schuver, Bazetta; Jena, Bipulendu; Bishop, Michael R.; Gress, Ronald E.; Rosenberg, Steven A.

2013-01-01

New treatments are needed for B-cell malignancies persisting after allogeneic hematopoietic stem cell transplantation (alloHSCT). We conducted a clinical trial of allogeneic T cells genetically modified to express a chimeric antigen receptor (CAR) targeting the B-cell antigen CD19. T cells for genetic modification were obtained from each patient’s alloHSCT donor. All patients had malignancy that persisted after alloHSCT and standard donor lymphocyte infusions (DLIs). Patients did not receive chemotherapy prior to the CAR T-cell infusions and were not lymphocyte depleted at the time of the infusions. The 10 treated patients received a single infusion of allogeneic anti-CD19-CAR T cells. Three patients had regressions of their malignancies. One patient with chronic lymphocytic leukemia (CLL) obtained an ongoing complete remission after treatment with allogeneic anti-CD19-CAR T cells, another CLL patient had tumor lysis syndrome as his leukemia dramatically regressed, and a patient with mantle cell lymphoma obtained an ongoing partial remission. None of the 10 patients developed graft-versus-host disease (GVHD). Toxicities included transient hypotension and fever. We detected cells containing the anti-CD19-CAR gene in the blood of 8 of 10 patients. These results show for the first time that donor-derived allogeneic anti-CD19-CAR T cells can cause regression of B-cell malignancies resistant to standard DLIs without causing GVHD. This trial was registered at www.clinicaltrials.gov as #NCT01087294. PMID:24055823

Identification and proteomic analysis of osteoblast-derived exosomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ge, Min; Ke, Ronghu; Cai, Tianyi

Exosomes are nanometer-sized vesicles with the function of intercellular communication, and they are released by various cell types. To reveal the knowledge about the exosomes from osteoblast, and explore the potential functions of osteogenesis, we isolated microvesicles from supernatants of mouse Mc3t3 by ultracentrifugation, characterized exosomes by electron microscopy and immunoblotting and presented the protein profile by proteomic analysis. The result demonstrated that microvesicles were between 30 and 100 nm in diameter, round shape with cup-like concavity and expressed exosomal marker tumor susceptibility gene (TSG) 101 and flotillin (Flot) 1. We identified a total number of 1069 proteins among which 786more » proteins overlap with ExoCarta database. Gene Oncology analysis indicated that exosomes mostly derived from plasma membrane and mainly involved in protein localization and intracellular signaling. The Ingenuity Pathway Analysis showed pathways are mostly involved in exosome biogenesis, formation, uptake and osteogenesis. Among the pathways, eukaryotic initiation factor 2 pathways played an important role in osteogenesis. Our study identified osteoblast-derived exosomes, unveiled the content of them, presented potential osteogenesis-related proteins and pathways and provided a rich proteomics data resource that will be valuable for further studies of the functions of individual proteins in bone diseases. - Highlights: • We for the first time identified exosomes from mouse osteoblast. • Osteoblasts-derived exosomes contain osteoblast peculiar proteins. • Proteins from osteoblasts-derived exosomes are intently involved in EIF2 pathway. • EIF2α from the EIF2 pathway plays an important role in osteogenesis.« less

The intrinsic shape of bulges in the CALIFA survey

NASA Astrophysics Data System (ADS)

Costantin, L.; Méndez-Abreu, J.; Corsini, E. M.; Eliche-Moral, M. C.; Tapia, T.; Morelli, L.; Dalla Bontà, E.; Pizzella, A.

2018-02-01

Context. The intrinsic shape of galactic bulges in nearby galaxies provides crucial information to separate bulge types. Aims: We aim to derive accurate constraints to the intrinsic shape of bulges to provide new clues on their formation mechanisms and set new limitations for future simulations. Methods: We retrieved the intrinsic shape of a sample of CALIFA bulges using a statistical approach. Taking advantage of GalMer numerical simulations of binary mergers we estimated the reliability of the procedure. Analyzing the i-band mock images of resulting lenticular remnants, we studied the intrinsic shape of their bulges at different galaxy inclinations. Finally, we introduced a new (B/A, C/A) diagram to analyze possible correlations between the intrinsic shape and the properties of bulges. Results: We tested the method on simulated lenticular remnants, finding that for galaxies with inclinations of 25° ≤ θ ≤ 65° we can safely derive the intrinsic shape of their bulges. We found that our CALIFA bulges tend to be nearly oblate systems (66%), with a smaller fraction of prolate spheroids (19%), and triaxial ellipsoids (15%). The majority of triaxial bulges are in barred galaxies (75%). Moreover, we found that bulges with low Sérsic indices or in galaxies with low bulge-to-total luminosity ratios form a heterogeneous class of objects; additionally, bulges in late-type galaxies or in less massive galaxies have no preference for being oblate, prolate, or triaxial. On the contrary, bulges with high Sérsic index, in early-type galaxies, or in more massive galaxies are mostly oblate systems. Conclusions: We concluded that various evolutionary pathways may coexist in galaxies, with merging events and dissipative collapse being the main mechanisms driving the formation of the most massive oblate bulges and bar evolution reshaping the less massive triaxial bulges.

Facet tropism and interfacet shape in the thoracolumbar vertebrae: characterization and biomechanical interpretation.

PubMed

Masharawi, Youssef; Rothschild, Bruce; Salame, Khalil; Dar, Gali; Peleg, Smadar; Hershkovitz, Israel

2005-06-01

Thoracolumbar facet and interfacet linear dimensions were measured and analyzed. To characterize and analyze the thoracolumbar facet and interfacet size and shape in relation to gender, ethnic group, and age and to detect the extent of normal facet tropism along the thoracolumbar spine. Knowledge on facet tropism and interfacet shape is limited in the literature as most data are based on 2-dimensional measurements, small samples, or isolated vertebrae. Facet shape as represented by width, length, width/length ratio and interfacet distances was obtained directly from dry vertebrae of 240 adult human spines. The specimen's osteologic material is part of the Hamann-Todd Osteological Collection housed at the Cleveland Museum of Natural History, Cleveland, OH. A total of 4080 vertebrae (T1-L5) from the vertebral columns of individuals 20 to 80 years of age were measured, using a Microscribe 3-dimensional apparatus (Immersion Co., San Jose, CA). Data were recorded directly on computer software. Statistical analysis included paired t tests and ANOVA. A significant correlation was found between all thoracolumbar facet dimensions and an individual's height and weight. Facet tropism is a major characteristic of the thoracolumbar spine, the left being longer in the thorax while the right is longer in the lumbar. In general, facet size is age-independent and greater in males compared with females with a significant ethnic component. Facet length is similar for all thoracic vertebrae, whereas it sharply and continuously increases in the lumbar vertebrae. Facet dimension manifests a bipolar distribution along the thoracolumbar vertebrae. Width/length ratio indicates that facets are longer than wider for most verte-brae. The interarticular area manifests a marked inverted trapezoidal shape at T1-T2, a rectangular shape at T3-L3, and an ordinary trapezoidal shape at L4-L5. Facet tropism is a normal characteristic in humans, yet it varies along the thoracolumbar spine.

Magnet pole shape design for reduction of thrust ripple of slotless permanent magnet linear synchronous motor with arc-shaped magnets considering end-effect based on analytical method

NASA Astrophysics Data System (ADS)

Shin, Kyung-Hun; Park, Hyung-Il; Kim, Kwan-Ho; Jang, Seok-Myeong; Choi, Jang-Young

2017-05-01

The shape of the magnet is essential to the performance of a slotless permanent magnet linear synchronous machine (PMLSM) because it is directly related to desirable machine performance. This paper presents a reduction in the thrust ripple of a PMLSM through the use of arc-shaped magnets based on electromagnetic field theory. The magnetic field solutions were obtained by considering end effect using a magnetic vector potential and two-dimensional Cartesian coordinate system. The analytical solution of each subdomain (PM, air-gap, coil, and end region) is derived, and the field solution is obtained by applying the boundary and interface conditions between the subdomains. In particular, an analytical method was derived for the instantaneous thrust and thrust ripple reduction of a PMLSM with arc-shaped magnets. In order to demonstrate the validity of the analytical results, the back electromotive force results of a finite element analysis and experiment on the manufactured prototype model were compared. The optimal point for thrust ripple minimization is suggested.

Comparison of dynamic contrast-enhanced MRI parameters of breast lesions at 1.5 and 3.0 T: a pilot study

PubMed Central

Pineda, F D; Medved, M; Fan, X; Ivancevic, M K; Abe, H; Shimauchi, A; Newstead, G M

2015-01-01

Objective: To compare dynamic contrast-enhanced (DCE) MRI parameters from scans of breast lesions at 1.5 and 3.0 T. Methods: 11 patients underwent paired MRI examinations in both Philips 1.5 and 3.0 T systems (Best, Netherlands) using a standard clinical fat-suppressed, T1 weighted DCE-MRI protocol, with 70–76 s temporal resolution. Signal intensity vs time curves were fit with an empirical mathematical model to obtain semi-quantitative measures of uptake and washout rates as well as time-to-peak enhancement (TTP). Maximum percent enhancement and signal enhancement ratio (SER) were also measured for each lesion. Percent differences between parameters measured at the two field strengths were compared. Results: TTP and SER parameters measured at 1.5 and 3.0 T were similar; with mean absolute differences of 19% and 22%, respectively. Maximum percent signal enhancement was significantly higher at 3 T than at 1.5 T (p = 0.006). Qualitative assessment showed that image quality was significantly higher at 3 T (p = 0.005). Conclusion: Our results suggest that TTP and SER are more robust to field strength change than other measured kinetic parameters, and therefore measurements of these parameters can be more easily standardized than measurements of other parameters derived from DCE-MRI. Semi-quantitative measures of overall kinetic curve shape showed higher reproducibility than do discrete classification of kinetic curve early and delayed phases in a majority of the cases studied. Advances in knowledge: Qualitative measures of curve shape are not consistent across field strength even when acquisition parameters are standardized. Quantitative measures of overall kinetic curve shape, by contrast, have higher reproducibility. PMID:25785918

Measuring the X-shaped structures in edge-on galaxies

NASA Astrophysics Data System (ADS)

Savchenko, S. S.; Sotnikova, N. Ya.; Mosenkov, A. V.; Reshetnikov, V. P.; Bizyaev, D. V.

2017-11-01

We present a detailed photometric study of a sample of 22 edge-on galaxies with clearly visible X-shaped structures. We propose a novel method to derive geometrical parameters of these features, along with the parameters of their host galaxies based on the multi-component photometric decomposition of galactic images. To include the X-shaped structure into our photometric model, we use the imfit package, in which we implement a new component describing the X-shaped structure. This method is applied for a sample of galaxies with available Sloan Digital Sky Survey and Spitzer IRAC 3.6 μm observations. In order to explain our results, we perform realistic N-body simulations of a Milky Way-type galaxy and compare the observed and the model X-shaped structures. Our main conclusions are as follows: (1) galaxies with strong X-shaped structures reside in approximately the same local environments as field galaxies; (2) the characteristic size of the X-shaped structures is about 2/3 of the bar size; (3) there is a correlation between the X-shaped structure size and its observed flatness: the larger structures are more flattened; (4) our N-body simulations qualitatively confirm the observational results and support the bar-driven scenario for the X-shaped structure formation.

Static shape control for flexible structures

NASA Technical Reports Server (NTRS)

Rodriguez, G.; Scheid, R. E., Jr.

1986-01-01

An integrated methodology is described for defining static shape control laws for large flexible structures. The techniques include modeling, identifying and estimating the control laws of distributed systems characterized in terms of infinite dimensional state and parameter spaces. The models are expressed as interconnected elliptic partial differential equations governing a range of static loads, with the capability of analyzing electromagnetic fields around antenna systems. A second-order analysis is carried out for statistical errors, and model parameters are determined by maximizing an appropriate defined likelihood functional which adjusts the model to observational data. The parameter estimates are derived from the conditional mean of the observational data, resulting in a least squares superposition of shape functions obtained from the structural model.

Hippocampal shape deformation in female patients with unremitting major depressive disorder.

PubMed

Tae, W S; Kim, S S; Lee, K U; Nam, E C; Choi, J W; Park, J I

2011-04-01

The hippocampal atrophy of MDD has been known, but the region shape contractions of the hippocampus in MDD were inconsistent. Spheric harmonic shape analysis was applied to the hippocampus in female patients with unremitting MDD to evaluate morphometric changes of the hippocampus. Shape analysis was performed by using T1-weighted MR imaging in 21 female patients with MDD and 21 age- and sex-matched healthy controls. Manually segmented hippocampi were parameterized, and the point-to-point-based group difference was compared by using the Hotelling T-squared test. The partial correlation analyses were tested between clinical variables and shape changes. Both hippocampal volumes were small in patients with MDD compared with healthy controls, and the right hippocampal volume was negatively correlated with the number of episodes at marginal significance. Regional shape contractions were found in the ambient gyrus, basal hippocampal head, posterior subiculum, and dorsal hippocampus of the left hemisphere. The right hippocampus showed a similar pattern but was less atrophic compared with the left hippocampus. A negative correlation was found between the HDRS and shape deformation in the CA3, ambient gyrus, posterior subiculum, and gyrus fasciolaris of the left hippocampus. We showed atrophy and regional shape contractions in the hippocampi of patients with MDD, which were more dominant on the left side. The causes of hippocampal damage could be the hypersecretion of glucocorticoids contributing to neuronal death or the failing of adult neurogenesis in the dentate gyrus.

Shape prior modeling using sparse representation and online dictionary learning.

PubMed

Zhang, Shaoting; Zhan, Yiqiang; Zhou, Yan; Uzunbas, Mustafa; Metaxas, Dimitris N

2012-01-01

The recently proposed sparse shape composition (SSC) opens a new avenue for shape prior modeling. Instead of assuming any parametric model of shape statistics, SSC incorporates shape priors on-the-fly by approximating a shape instance (usually derived from appearance cues) by a sparse combination of shapes in a training repository. Theoretically, one can increase the modeling capability of SSC by including as many training shapes in the repository. However, this strategy confronts two limitations in practice. First, since SSC involves an iterative sparse optimization at run-time, the more shape instances contained in the repository, the less run-time efficiency SSC has. Therefore, a compact and informative shape dictionary is preferred to a large shape repository. Second, in medical imaging applications, training shapes seldom come in one batch. It is very time consuming and sometimes infeasible to reconstruct the shape dictionary every time new training shapes appear. In this paper, we propose an online learning method to address these two limitations. Our method starts from constructing an initial shape dictionary using the K-SVD algorithm. When new training shapes come, instead of re-constructing the dictionary from the ground up, we update the existing one using a block-coordinates descent approach. Using the dynamically updated dictionary, sparse shape composition can be gracefully scaled up to model shape priors from a large number of training shapes without sacrificing run-time efficiency. Our method is validated on lung localization in X-Ray and cardiac segmentation in MRI time series. Compared to the original SSC, it shows comparable performance while being significantly more efficient.

A Biological-Plausable Architecture for Shape Recognition

DTIC Science & Technology

2006-06-30

between curves. Information Processing Letters, 64, 1997. [4] Irving Biederman . Recognition-by-components: A theory of human image understanding...Psychological Review, 94(2):115–147, 1987 . 43 [5] C. Cadieu, M. Kouh, M. Riesenhuber, and T. Poggio. Shape representation in v4: Investi- gating position

Multi-resolution Shape Analysis via Non-Euclidean Wavelets: Applications to Mesh Segmentation and Surface Alignment Problems.

PubMed

Kim, Won Hwa; Chung, Moo K; Singh, Vikas

2013-01-01

The analysis of 3-D shape meshes is a fundamental problem in computer vision, graphics, and medical imaging. Frequently, the needs of the application require that our analysis take a multi-resolution view of the shape's local and global topology, and that the solution is consistent across multiple scales. Unfortunately, the preferred mathematical construct which offers this behavior in classical image/signal processing, Wavelets, is no longer applicable in this general setting (data with non-uniform topology). In particular, the traditional definition does not allow writing out an expansion for graphs that do not correspond to the uniformly sampled lattice (e.g., images). In this paper, we adapt recent results in harmonic analysis, to derive Non-Euclidean Wavelets based algorithms for a range of shape analysis problems in vision and medical imaging. We show how descriptors derived from the dual domain representation offer native multi-resolution behavior for characterizing local/global topology around vertices. With only minor modifications, the framework yields a method for extracting interest/key points from shapes, a surprisingly simple algorithm for 3-D shape segmentation (competitive with state of the art), and a method for surface alignment (without landmarks). We give an extensive set of comparison results on a large shape segmentation benchmark and derive a uniqueness theorem for the surface alignment problem.

Shape Control of Plates with Piezo Actuators and Collocated Position/Rate Sensors

NASA Technical Reports Server (NTRS)

Balakrishnan, A. V.

1994-01-01

This paper treats the control problem of shaping the surface deformation of a circular plate using embedded piezo-electric actuators and collocated rate sensors. An explicit Linear Quadratic Gaussian (LQG) optimizer stability augmentation compensator is derived as well as the optimal feed-forward control. Corresponding performance evaluation formulas are also derived.

Shape Control of Plates with Piezo Actuators and Collocated Position/Rate Sensors

NASA Technical Reports Server (NTRS)

Balakrishnan, A. V.

1994-01-01

This paper treats the control problem of shaping the surface deformation of a circular plate using embedded piezo-electric actuator and collocated rate sensors. An explicit Linear Quadratic Gaussian (LQG) optimizer stability augmentation compensator is derived as well as the optimal feed-forward control. Corresponding performance evaluation formulas are also derived.

Pulse Shape Correlation for Laser Detection and Ranging (LADAR)

DTIC Science & Technology

2010-03-01

with the incoming measured laser pulse [3]. All of these shapes are symmetric. Siegman and Liu’s findings indicate that the pulse is seldom symmetric...of Engineering, Air Force Institute of Technology (AETC), Wright Pat- terson AFB, OH, March 2007. 10. Siegman , Anthony E. Lasers . University Science...Pulse Shape Correlation for Laser Detection and Ranging (LADAR) THESIS Brian T. Deas, Major, USAF AFIT/GE/ENG/10-07 DEPARTMENT OF THE AIR FORCE AIR

Assessment of Shape Changes of Mistletoe Berries: A New Software Approach to Automatize the Parameterization of Path Curve Shaped Contours

PubMed Central

Derbidge, Renatus; Feiten, Linus; Conradt, Oliver; Heusser, Peter; Baumgartner, Stephan

2013-01-01

Photographs of mistletoe (Viscum album L.) berries taken by a permanently fixed camera during their development in autumn were subjected to an outline shape analysis by fitting path curves using a mathematical algorithm from projective geometry. During growth and maturation processes the shape of mistletoe berries can be described by a set of such path curves, making it possible to extract changes of shape using one parameter called Lambda. Lambda describes the outline shape of a path curve. Here we present methods and software to capture and measure these changes of form over time. The present paper describes the software used to automatize a number of tasks including contour recognition, optimization of fitting the contour via hill-climbing, derivation of the path curves, computation of Lambda and blinding the pictures for the operator. The validity of the program is demonstrated by results from three independent measurements showing circadian rhythm in mistletoe berries. The program is available as open source and will be applied in a project to analyze the chronobiology of shape in mistletoe berries and the buds of their host trees. PMID:23565255

Identification of CD4+ T-cell-derived CD161+ CD39+ and CD39+CD73+ microparticles as new biomarkers for rheumatoid arthritis.

PubMed

Fan, Wenqiang; Wang, Wenxiang; Wu, Jie; Ma, Ling; Guo, Jinyan

2017-02-01

This study aimed to identify CD4 + T-cell-derived microparticles (MPs) and investigate their roles in rheumatoid arthritis (RA). Synovial fluids from 34 RA, 33 osteoarthritis patients and 42 healthy individuals were analyzed by flow cytometry. Human fibroblast-like synoviocytes and peripheral blood mononuclear cells were cultured with or without isolated MPs, chemokines and cytokines were measured by ELISA. CD4 + CD161 + CD39 + and CD4 + CD39 + CD73 + MPs were abundantly present in RA patients, which were positively or negatively correlated with RA features, respectively. Chemokines CCL20, CCL17 and CCL22, and cytokines IL-17 and IL-10 were influenced by these MPs in human fibroblast-like synoviocytes (HFLS) or PMBCs. CD4 + T-cell-derived CD161 + CD39 + and CD39 + CD73 + MPs could serve as new reciprocal biomarkers for RA evaluation.

Shape design sensitivity analysis and optimal design of structural systems

NASA Technical Reports Server (NTRS)

Choi, Kyung K.

1987-01-01

The material derivative concept of continuum mechanics and an adjoint variable method of design sensitivity analysis are used to relate variations in structural shape to measures of structural performance. A domain method of shape design sensitivity analysis is used to best utilize the basic character of the finite element method that gives accurate information not on the boundary but in the domain. Implementation of shape design sensitivty analysis using finite element computer codes is discussed. Recent numerical results are used to demonstrate the accuracy obtainable using the method. Result of design sensitivity analysis is used to carry out design optimization of a built-up structure.

Recent Progress on Modeling Slip Deformation in Shape Memory Alloys

NASA Astrophysics Data System (ADS)

Sehitoglu, H.; Alkan, S.

2018-03-01

This paper presents an overview of slip deformation in shape memory alloys. The performance of shape memory alloys depends on their slip resistance often quantified through the Critical Resolved Shear Stress (CRSS) or the flow stress. We highlight previous studies that identify the active slip systems and then proceed to show how non- Schmid effects can be dominant in shape memory slip behavior. The work is mostly derived from our recent studies while we highlight key earlier works on slip deformation. We finally discuss the implications of understanding the role of slip on curtailing the transformation strains and also the temperature range over which superelasticity prevails.

Naïve CD8 T cell activation by liver bone marrow-derived cells leads to a "neglected" IL-2low Bimhigh phenotype, poor CTL function and cell death.

PubMed

Holz, Lauren E; Benseler, Volker; Vo, Michelle; McGuffog, Claire; Van Rooijen, Nico; McCaughan, Geoffrey W; Bowen, David G; Bertolino, Patrick

2012-10-01

The occurrence of primary CD8 T cell activation within the liver, unique among the non-lymphoid organs, is now well accepted. However, the outcome of intrahepatic T cell activation remains controversial. We have previously reported that activation initiated by hepatocytes results in a tolerogenic phenotype characterized by low expression of CD25 and IL-2, poor cytotoxic T lymphocyte (CTL) function, and excessive expression of the pro-apoptotic protein Bim. To investigate whether this phenotype was due to activation in the absence of co-stimulation, we generated bone marrow (bm) radiation chimeras in which adoptively transferred naïve transgenic CD8 T cells were activated in the presence of co-stimulation by liver bm-derived cells. Despite expressing pro-inflammatory cytokines, high levels of CD25 and CD54, donor T cells activated by liver bm-derived cells did not produce detectable IL-2 and displayed poor CTL function, suggesting incomplete acquisition of effector function. Simultaneously, these cells expressed high levels of Bim and died by neglect. Transfer of Bim-deficient T cells resulted in increased T cell numbers. These results imply that expression of CD25 and CD54 is co-stimulation dependent and distinguishes T cell activated by hepatocytes and liver bm-derived cells. In contrast, low expression of IL-2, poor CTL function and excess Bim production represent a more universal phenotype defining T cells undergoing primary activation by both types of hepatic antigen presenting cells (APC). These results have important implications for transplantation, in which all liver antigen presenting cells contribute to activation of T cells specific for the allograft. Copyright © 2012 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Nonclassical MHC Ib-restricted CD8+ T Cells Recognize Mycobacterium tuberculosis-Derived Protein Antigens and Contribute to Protection Against Infection

PubMed Central

Shang, Shaobin; Siddiqui, Sarah; Bian, Yao; Zhao, Jie; Wang, Chyung-Ru

2016-01-01

MHC Ib-restricted CD8+ T cells have been implicated in host defense against Mycobacterium tuberculosis (Mtb) infection. However, the relative contribution of various MHC Ib-restricted T cell populations to anti-mycobacterial immunity remains elusive. In this study, we used mice that lack MHC Ia (Kb-/-Db-/-), MHC Ia/H2-M3 (Kb-/-Db-/-M3-/-), or β2m (β2m-/-) to study the role of M3-restricted and other MHC Ib-restricted T cells in immunity against Mtb. Unlike their dominant role in Listeria infection, we found that M3-restricted CD8+ T cells only represented a small proportion of the CD8+ T cells responding to Mtb infection. Non-M3, MHC Ib-restricted CD8+ T cells expanded preferentially in the lungs of Mtb-infected Kb-/-Db-/-M3-/- mice, exhibited polyfunctional capacities and conferred protection against Mtb. These MHC Ib-restricted CD8+ T cells recognized several Mtb-derived protein antigens at a higher frequency than MHC Ia-restricted CD8+ T cells. The presentation of Mtb antigens to MHC Ib-restricted CD8+ T cells was mostly β2m-dependent but TAP-independent. Interestingly, a large proportion of Mtb-specific MHC Ib-restricted CD8+ T cells in Kb-/-Db-/-M3-/- mice were Qa-2-restricted while no considerable numbers of MR1 or CD1-restricted Mtb-specific CD8+ T cells were detected. Our findings indicate that nonclassical CD8+ T cells other than the known M3, CD1, and MR1-restricted CD8+ T cells contribute to host immune responses against Mtb infection. Targeting these MHC Ib-restricted CD8+ T cells would facilitate the design of better Mtb vaccines with broader coverage across MHC haplotypes due to the limited polymorphism of MHC class Ib molecules. PMID:27272249

Allergen-specific T-cell tolerance induction with allergen-derived long synthetic peptides: results of a phase I trial.

PubMed

Fellrath, Jean-Marc; Kettner, Alexander; Dufour, Nathalie; Frigerio, Christian; Schneeberger, Dominique; Leimgruber, Annette; Corradin, Gampietro; Spertini, François

2003-04-01

There is a need to improve the safety and efficacy of allergen-specific immunotherapy. Long synthetic peptide-based immunotherapy was proven safe, immunogenic, and protective in preclinical trials. To evaluate the safety and immunogenicity of an allergen-derived long synthetic overlapping peptide (LSP) immunotherapy, we designed a double-blind, placebo-controlled phase I clinical trial in patients hypersensitive to bee venom. Patients from the active group were injected at day 0 with a mixture of 3 LSPs mapping the entire PLA2 molecule, a major bee venom allergen, in a dose-escalating protocol to a maintenance dose of 100 microg per peptide repeated at days 4, 7, 14, 42, and 70. The control group was injected with human albumin. Whereas specific T-cell proliferation in the peptide group increased up to day 14, a sharp decline was observed thereafter, ending in specific T-cell hyporesponsiveness at day 80. Serum-specific IgG4 response was enhanced, in contrast to anti-PLA2 IgE. Specific T-cell cytokine modulation was marked by increased IL-10 and IFN-gamma secretion. LSP injections were well tolerated in all patients except for mild, late allergic reactions in 2 patients at day 70. The results of this short-term study demonstrate that LSP-based allergen immunotherapy was safe and able to induce T(H)1-type immune deviation, allergen-specific IL-10 production, and T-cell hyporesponsiveness. LSPs, which offer the advantage of covering all possible T-cell epitopes for any HLA genotype, can be considered candidates for a novel and safe approach of specific immunotherapy.

Advanced transcatheter aortic valve implantation (TAVI) planning from CT with ShapeForest.

PubMed

Swee, Joshua K Y; Grbić, Saša

2014-01-01

Transcatheter aortic valve implantation (TAVI) is becoming a standard treatment for non-operable and high-risk patients with symptomatic severe aortic valve stenosis. As there is no direct view or access to the affected anatomy, comprehensive preoperative planning is crucial for a successful outcome, with the most important decisions made during planning being the selection of the proper implant size, and determining the correct C-arm angulations. While geometric models extracted from 3D images are often used to derive these measurements, the complex shape variation of the AV anatomy found in these patients causes many of the shape representations used to estimate such geometric models to fail in capturing morphological characteristics in sufficient detail. In addition, most current approaches only model the aortic valve (AV), omitting modeling the left ventricle outflow tract (LVOT) entirely despite its high correlation with severe complications such as annulus ruptures, paravalvular leaks and myocardial infarction. We propose a fully automated method to extract patient specific models of the AV and the LVOT, and derive comprehensive biomarkers for accurate TAVI planning. We utilize a novel shape representation--the ShapeForest--which is able to model complex shape variation, preserves local shape information, and incorporates prior knowledge during shape space inference. Extensive quantitative and qualitative experiments performed on 630 volumetric data sets demonstrate an accuracy of 0.69 mm for the AV and 0.83 mm for the LVOT, an improvement of over 16% and 18% respectively when compared against state of the art methods.

Shape optimization of road tunnel cross-section by simulated annealing

NASA Astrophysics Data System (ADS)

Sobótka, Maciej; Pachnicz, Michał

2016-06-01

The paper concerns shape optimization of a tunnel excavation cross-section. The study incorporates optimization procedure of the simulated annealing (SA). The form of a cost function derives from the energetic optimality condition, formulated in the authors' previous papers. The utilized algorithm takes advantage of the optimization procedure already published by the authors. Unlike other approaches presented in literature, the one introduced in this paper takes into consideration a practical requirement of preserving fixed clearance gauge. Itasca Flac software is utilized in numerical examples. The optimal excavation shapes are determined for five different in situ stress ratios. This factor significantly affects the optimal topology of excavation. The resulting shapes are elongated in the direction of a principal stress greater value. Moreover, the obtained optimal shapes have smooth contours circumscribing the gauge.

Improved Shaping Approach to the Preliminary Design of Low-Thrust Trajectories

NASA Astrophysics Data System (ADS)

Novak, D. M.; Vasile, M.

2011-01-01

This paper presents a general framework for the development of shape-based approaches to low-thrust trajectory design. A novel shaping method, based on a three-dimensional description of the trajectory in spherical coordinates, is developed within this general framework. Both the exponential sinusoid and the inverse polynomial shaping are demonstrated to be particular two-dimensional cases of the spherical one. The pseudoequinoctial shaping is revisited within the new framework, and the nonosculating nature of the pseudoequinoctial elements is analyzed. A two-step approach is introduced to solve the time of flight constraint, related to the design of low-thrust arcs with boundary constraints for both spherical and pseudoequinoctial shaping. The solution derived from the shaping approach is improved with a feedback linear-quadratic controller and compared against a direct collocation method based on finite elements in time. The new shaping approach and the combination of shaping and linear-quadratic controller are tested on three case studies: a mission to Mars, a mission to asteroid 1989ML, a mission to comet Tempel-1, and a mission to Neptune.

Homeostatic regulation of T cell trafficking by a B cell-derived peptide is impaired in autoimmune and chronic inflammatory disease.

PubMed

Chimen, Myriam; McGettrick, Helen M; Apta, Bonita; Kuravi, Sahithi J; Yates, Clara M; Kennedy, Amy; Odedra, Arjun; Alassiri, Mohammed; Harrison, Matthew; Martin, Ashley; Barone, Francesca; Nayar, Saba; Hitchcock, Jessica R; Cunningham, Adam F; Raza, Karim; Filer, Andrew; Copland, David A; Dick, Andrew D; Robinson, Joseph; Kalia, Neena; Walker, Lucy S K; Buckley, Christopher D; Nash, Gerard B; Narendran, Parth; Rainger, G Ed

2015-05-01

During an inflammatory response, lymphocyte recruitment into tissue must be tightly controlled because dysregulated trafficking contributes to the pathogenesis of chronic disease. Here we show that during inflammation and in response to adiponectin, B cells tonically inhibit T cell trafficking by secreting a peptide (PEPITEM) proteolytically derived from 14.3.3 zeta delta (14.3.3.ζδ) protein. PEPITEM binds cadherin-15 on endothelial cells, promoting synthesis and release of sphingosine-1 phosphate, which inhibits trafficking of T cells without affecting recruitment of other leukocytes. Expression of adiponectin receptors on B cells and adiponectin-induced PEPITEM secretion wanes with age, implying immune senescence of the pathway. Additionally, these changes are evident in individuals with type 1 diabetes or rheumatoid arthritis, and circulating PEPITEM in patient serum is reduced compared to that of healthy age-matched donors. In both diseases, tonic inhibition of T cell trafficking across inflamed endothelium is lost. Control of patient T cell trafficking is re-established by treatment with exogenous PEPITEM. Moreover, in animal models of peritonitis, hepatic ischemia-reperfusion injury, Salmonella infection, uveitis and Sjögren's syndrome, PEPITEM reduced T cell recruitment into inflamed tissues.

Homeostatic regulation of T cell trafficking by a B cell derived peptide is impaired in autoimmune and chronic inflammatory disease

PubMed Central

Apta, Bonita; Kuravi, Sahithi J.; Yates, Clara M.; Kennedy, Amy; Odedra, Arjun; Alassiri, Mohammed; Harrison, Matthew; Martin, Ashley; Barone, Francesca; Nayar, Saba; Hitchcock, Jessica R.; Cunningham, Adam F.; Raza, Karim; Filer, Andrew; Copland, David A.; Dick, Andrew D.; Robinson, Joseph; Kalia, Neena; Walker, Lucy S. K.; Buckley, Christopher D.; Nash, Gerard B.; Narendran, Parth; Rainger, G. Ed.

2015-01-01

During an inflammatory response, lymphocyte recruitment into tissue must be tightly controlled because dysregulated trafficking contributes to the pathogenesis of chronic disease. Here we show that during inflammation and in response to adiponectin, B cells tonically inhibit T cell trafficking by secreting a peptide (PEPITEM) proteolytically derived from 14.3.3.ζδ protein. PEPITEM binds cadherin-15 on endothelial cells, promoting synthesis and release of sphingosine-1 phosphate, which inhibits trafficking of T cells without affecting recruitment of other leukocytes. Expression of adiponectin receptors on B cells and adiponectin induced PEPITEM secretion wanes with age, implying immune senescence of the pathway. Additionally, these changes are evident in individuals with type-1-diabetes or rheumatoid arthritis, and circulating PEPITEM in patient serum is reduced compared to healthy age matched donors. In both diseases, tonic inhibition of T cell trafficking across inflamed endothelium is lost. Importantly, control of patient T cell trafficking is re-established by exogenous PEPITEM. Moreover, in animal models of peritonitis, hepatic I/R injury, Salmonella infection, Uveitis and Sjögren’s Syndrome, PEPITEM could reduce T cell recruitment into inflamed tissues. PMID:25894827

Temperature-Tuned Faceting and Shape Changes in Liquid Alkane Droplets

DOE PAGES

Guttman, Shani; Sapir, Zvi; Ocko, Benjamin M.; ...

2017-01-09

Recent extensive studies reveal that surfactant-stabilized spherical alkane emulsion droplets spontaneously adopt polyhedral shapes upon cooling below a temperature T d while remaining liquid. Further cooling induces the growth of tails and spontaneous droplet splitting. Two mechanisms were offered to account for these intriguing effects. One assigns the effects to the formation of an intradroplet frame of tubules consisting of crystalline rotator phases with cylindrically curved lattice planes. The second assigns the sphere-to-polyhedron transition to the buckling of defects in a crystalline interfacial monolayer, known to form in these systems at some T s > T d. The buckling reducesmore » the extensional energy of the crystalline monolayer’s defects, unavoidably formed when wrapping a spherical droplet by a hexagonally packed interfacial monolayer. The tail growth, shape changes, and droplet splitting were assigned to the decrease and vanishing of surface tension, γ. Here we present temperature-dependent γ(T), optical microscopy measurements, and interfacial entropy determinations for several alkane/surfactant combinations. We demonstrate the advantages and accuracy of the in situ γ(T) measurements made simultaneously with the microscopy measurements on the same droplet. The in situ and coinciding ex situ Wilhelmy plate γ(T) measurements confirm the low interfacial tension, ≲0.1 mN/m, observed at T d. Here, our results provide strong quantitative support validating the crystalline monolayer buckling mechanism.« less

Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

NASA Astrophysics Data System (ADS)

Sanchez, Christopher A.; Ruddell, Benjamin L.; Schiesser, Roy; Merwade, Venkatesh

2016-03-01

Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data-driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower-division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

NASA Astrophysics Data System (ADS)

Sanchez, C. A.; Ruddell, B. L.; Schiesser, R.; Merwade, V.

2015-07-01

Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

Melanoma exosomes deliver a complex biological payload that upregulates PTPN11 to suppress T lymphocyte function

PubMed Central

Wu, Yueting; Deng, Wentao; McGinley, Emily Chambers; Klinke, David J.

2017-01-01

Summary As exosomes are emerging as a new mode of intercellular communication, we hypothesized that the payload contained within exosomes is shaped by somatic evolution. To test this, we assayed the impact on primary CD8+ T cell function, a key mechanism for anti-tumor immunity, of exosomes derived from three melanoma-related cell lines. While morphologically similar, exosomes from each cell line were functionally different, as B16F0 exosomes dose-dependently suppressed T cell proliferation. In contrast, Cloudman S91 exosomes promoted T cell proliferation and Melan-A exosomes had a negligible effect on primary CD8+ T cells. Mechanistically, transcript profiling suggested that exosomal mRNA is enriched for full-length mRNAs that target immune-related pathways. Interestingly, B16F0 exosomes were unique in that they contained both protein and mRNA for Ptpn11, which inhibited T cell proliferation. Collectively, the results suggest that upregulation of PTPN11 by B16F0 exosomes to tumor infiltrating lymphocytes would bypass the extracellular control of the immune checkpoints. PMID:27930879

Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Young-Il; Kim, Seung Hyun; Ju, Jung Won

Highlights: {yields} Treatment with Clonorchis sinensis-derived total protein attenuates OVA-induced airway inflammation and AHR to methacholine. {yields} Induction of CD4{sup +}CD25{sup +}Foxp3{sup +} T cells and IL-10 along with suppression of splenocyte proliferation by C. sinensis-derived total protein. {yields} C. sinensis-derived total protein interferes with the expression of co-stimulatory molecules in DCs. -- Abstract: Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct ofmore » humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4{sup +}CD25{sup +}Foxp3{sup +} regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naive T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the

An approach to predict the shape-memory behavior of amorphous polymers from Dynamic Mechanical Analysis (DMA) data

NASA Astrophysics Data System (ADS)

Kuki, Ákos; Czifrák, Katalin; Karger-Kocsis, József; Zsuga, Miklós; Kéki, Sándor

2015-02-01

The prediction of shape-memory behavior is essential regarding the design of a smart material for different applications. This paper proposes a simple and quick method for the prediction of shape-memory behavior of amorphous shape memory polymers (SMPs) on the basis of a single dynamic mechanical analysis (DMA) temperature sweep at constant frequency. All the parameters of the constitutive equations for linear viscoelasticity are obtained by fitting the DMA curves. The change with the temperature of the time-temperature superposition shift factor ( a T ) is expressed by the Williams-Landel-Ferry (WLF) model near and above the glass transition temperature ( T g ), and by the Arrhenius law below T g . The constants of the WLF and Arrhenius equations can also be determined. The results of our calculations agree satisfactorily with the experimental free recovery curves from shape-memory tests.

Saussurea tridactyla Sch. Bip.-derived polysaccharides and flavones reduce oxidative damage in ultraviolet B-irradiated HaCaT cells via a p38MAPK-independent mechanism

PubMed Central

Guo, Yan; Sun, Juan; Ye, Juan; Ma, Wenyu; Yan, Hualing; Wang, Gang

2016-01-01

Objective To investigate whether Saussurea tridactyla Sch. Bip.-derived polysaccharides and flavones exert apoptosis-inhibiting effects in ultraviolet B (UVB)-irradiated HaCaT cells. Methods We divided HaCaT cells into low radiation UVB and high radiation UVB groups. Low radiation UVB and high radiation UVB groups were further divided into a control group, UVB radiation group (UVB group), S. tridactyla Sch. Bip.-derived polysaccharides and flavones low-dose group, and S. tridactyla Sch. Bip.-derived polysaccharides and flavones high-dose group. Cell viability and morphology were assayed by MTT and trypan blue staining. Superoxide dismutase activity, glutathione content, malondialdehyde content, and catalase activity test kits were used to detect superoxide dismutase activity, glutathione content, malondialdehyde content, and catalase activity, respectively. Cell apoptosis, intracellular Ca2+ levels, and mitochondrial membrane potential (Δψ) were detected by flow cytometry. Protein levels were analyzed by Western blotting and immunofluorescence. Results S. tridactyla Sch. Bip.-derived polysaccharides and flavones were found to increase the absorbance of MTT, decrease cell death, alleviate the degree of cell edema, restore the cell morphology, reduce cell death fragments and chip phenomenon, increase superoxide dismutase activity, glutathione content, and catalase activity while decreasing the content of malondialdehyde, lowering the population of apoptotic cells, reducing the intracellular Ca2+ fluorescence, increasing the mitochondrial membrane potential (Δψ), increasing the expressions of p-38, p-53, Bcl-2, and decreasing the expressions of Bax and active-caspase-3. Conclusion S. tridactyla Sch. Bip.-derived polysaccharides and flavones can reduce cell apoptosis to protect HaCaT cells from oxidative damage after UVB irradiation; however, this effect does not occur via the p38MAPK pathway. PMID:26855564

Buildings Change Detection Based on Shape Matching for Multi-Resolution Remote Sensing Imagery

NASA Astrophysics Data System (ADS)

Abdessetar, M.; Zhong, Y.

2017-09-01

Buildings change detection has the ability to quantify the temporal effect, on urban area, for urban evolution study or damage assessment in disaster cases. In this context, changes analysis might involve the utilization of the available satellite images with different resolutions for quick responses. In this paper, to avoid using traditional method with image resampling outcomes and salt-pepper effect, building change detection based on shape matching is proposed for multi-resolution remote sensing images. Since the object's shape can be extracted from remote sensing imagery and the shapes of corresponding objects in multi-scale images are similar, it is practical for detecting buildings changes in multi-scale imagery using shape analysis. Therefore, the proposed methodology can deal with different pixel size for identifying new and demolished buildings in urban area using geometric properties of objects of interest. After rectifying the desired multi-dates and multi-resolutions images, by image to image registration with optimal RMS value, objects based image classification is performed to extract buildings shape from the images. Next, Centroid-Coincident Matching is conducted, on the extracted building shapes, based on the Euclidean distance measurement between shapes centroid (from shape T0 to shape T1 and vice versa), in order to define corresponding building objects. Then, New and Demolished buildings are identified based on the obtained distances those are greater than RMS value (No match in the same location).

Two-way shape memory behavior of semi-crystalline elastomer under stress-free condition

NASA Astrophysics Data System (ADS)

Qian, Chen; Dong, Yubing; Zhu, Yaofeng; Fu, Yaqin

2016-08-01

Semi-crystalline shape memory polymers exhibit two-way shape memory effect (2W-SME) under constant stresses through crystallization-induced elongation upon cooling and melting-induced constriction upon heating. The applied constant stress influenced the prediction and usability of 2W-SME in practical applications without any external force. Here the reversible shape transition in EVA-shaped memory polymer was quantitative analyzed under a suitable temperature range and external stress-free condition. The fraction of reversible strain increased with increasing upper temperature (T high) within the temperature range and reached the maximum value of 13.62% at 70 °C. However, reversible strain transition was almost lost when T high exceeded 80 °C because of complete melting of crystalline scaffold, known as the latent recrystallization template. The non-isothermal annealing of EVA 2W-SMP under changing circulating temperatures was confirmed. Moreover, the orientation of crystallization was retained at high temperatures. These findings may contribute to design an appropriate shape memory protocol based on application-specific requirements.

Study of the Mixing Regimes of a Fluid and a Nanofluid in a T-shaped Micromixer

NASA Astrophysics Data System (ADS)

Lobasov, A. S.; Minakov, A. V.; Rudyak, V. Ya.

2018-01-01

In the present paper, the regimes of flow and mixing of water and a nanofluid with aluminum oxide nanoparticles in a T-shaped microchannel have been studied numerically. The Reynolds number was varied from 10 to 400, and the volume concentration of nanoparticles was varied from 0 to 10%. Nanofluids with mean sizes of particles from 50 to 150 nm were considered. The viscosity coefficient of the nanofluid was taken from experimental data. In all cases, it exceeded the viscosity coefficient of water and depended on not only the concentration of nanoparticles, but also on their sizes, and the viscosity of the nanofluid with smaller particles was higher than the viscosity of the nanofluid with large particles. It has been established that there exist regimes of steady irrotational flow, steady vortex flow with two horseshoe vortices, and steady flow with two vortices in the mixing channel. It has been shown that when the flow goes from the regime with horseshoe vortices to the flow conditions with two single vortices, the mixing efficiency increases several times. It has been established that the flow conditions and the mixing efficiency largely depend on the volume concentration of particles and their sizes.

MHC drives TCR repertoire shaping, but not maturation, in recent thymic emigrants.

PubMed

Houston, Evan G; Fink, Pamela J

2009-12-01

After developing in the thymus, recent thymic emigrants (RTEs) enter the lymphoid periphery and undergo a maturation process as they transition into the mature naive (MN) T cell compartment. This maturation presumably shapes RTEs into a pool of T cells best fit to function robustly in the periphery without causing autoimmunity; however, the mechanism and consequences of this maturation process remain unknown. Using a transgenic mouse system that specifically labels RTEs, we tested the influence of MHC molecules, key drivers of intrathymic T cell selection and naive peripheral T cell homeostasis, in shaping the RTE pool in the lymphoid periphery. We found that the TCRs expressed by RTEs are skewed to longer CDR3 regions compared with those of MN T cells, suggesting that MHC does streamline the TCR repertoire of T cells as they transition from the RTE to the MN T cell stage. This conclusion is borne out in studies in which the representation of individual TCRs was followed as a function of time since thymic egress. Surprisingly, we found that MHC is dispensable for the phenotypic and functional maturation of RTEs.

Effects of shape, size, and pyrene doping on electronic properties of graphene nanoflakes.

PubMed

Kuamit, Thanawit; Ratanasak, Manussada; Rungnim, Chompoonut; Parasuk, Vudhichai

2017-11-25

Effects of size, shape, and pyrene doping on electronic properties of graphene nanoflakes (GNFs) were theoretically investigated using density functional theory method with PBE, B3PW91, and M06-2X functionals and cc-pVDZ basis set. Two shapes of zigzag GNFs, hexagonal (HGN) and rhomboidal (RGN), were considered. The energy band gap of GNF depends on shape and decreases with size. The HGN has larger band gap energy (1.23-3.96 eV) than the RGN (0.13-2.12 eV). The doping of pyrene and pyrene derivatives on both HGN and RGN was also studied. The adsorption energy of pyrene and pyrene derivatives on GNF does not depend on the shape of GNFs with energies between 21 and 27 kcal mol -1 . The substituent on pyrene enhances the binding to GNF but the strength does not depend on electron withdrawing or donating capability. The doping by pyrene and pyrene derivatives also shifts the HOMO and LUMO energies of GNFs. Both positive (destabilizing) and negative (stabilizing) shifts on HOMO and LUMO of GNFs were seen. The direction and magnitude of the shift do not follow the electron withdrawing and donating capability of pyrene substituents. However, only a slight shift was observed for doped RGN. A shift of 0.19 eV was noticed for HOMO of HGN doped with 1-aminopyrene (pyNH 2 ) and of 0.04 eV for LUMO of HGN doped with 1-pyrenecarboxylic acid (pyCOOH). Graphical Abstract HOMO and LUMO Energies of pyrene/pyrene derivatives doped Graphene Nanoflakes.

Chemotherapy alters the increased numbers of myeloid-derived suppressor and regulatory T cells in children with acute lymphoblastic leukemia.

PubMed

Salem, Mohamed Labib; El-Shanshory, Mohamed R; Abdou, Said H; Attia, Mohamed S; Sobhy, Shymaa M; Zidan, Mona F; Zidan, Abdel-Aziz A

2018-04-01

Acute lymphoblastic leukemia (ALL) is the most common cancer diagnosed in children. The precise mechanism behind the relapse in this disease is not clearly known. One possible mechanism could be the accumulation of immunosuppressive cells, including myeloid-derived suppressor cells (MDSCs) and T regulatory cells (T regs ) which we and others have reported to mediate suppression of anti-tumor immune responses. In this study, we aimed to analyze the numbers of these cells in a population of B-ALL pediatric patients. Peripheral blood samples withdrawn from B-ALL pediatric patients (n = 45 before, during and after the induction phase of chemotherapy. Using multi parametric flow cytometric analysis. MDSCs were identified as Lin - HLA-DR - CD33 + CD11b + ; and T reg cells were defined as CD4 + CD25 + CD127 -/low . Early diagnosed B-ALL patients showed significant increases in the numbers of MDSCs and T regs as compared to healthy volunteers. During induction of chemotherapy, however, the patients showed higher and lower numbers of MDSCs and T reg cells, respectively as compared to early diagnosed patients (i.e., before chemotherapy). After induction of chemotherapy, the numbers of MDSCs and T reg cells showed higher increases and decreases, respectively as compared to the numbers in patients during chemotherapy. Our results indicate that B-ALL patients harbor high numbers of both MDSCs and T regs cells. This pilot study opens a new avenue to investigate the mechanism mediating the emergence of these cells on larger number of B-ALL patients at different treatment stages.

SHAPE Selection (SHAPES) enrich for RNA structure signal in SHAPE sequencing-based probing data

PubMed Central

Poulsen, Line Dahl; Kielpinski, Lukasz Jan; Salama, Sofie R.; Krogh, Anders; Vinther, Jeppe

2015-01-01

Selective 2′ Hydroxyl Acylation analyzed by Primer Extension (SHAPE) is an accurate method for probing of RNA secondary structure. In existing SHAPE methods, the SHAPE probing signal is normalized to a no-reagent control to correct for the background caused by premature termination of the reverse transcriptase. Here, we introduce a SHAPE Selection (SHAPES) reagent, N-propanone isatoic anhydride (NPIA), which retains the ability of SHAPE reagents to accurately probe RNA structure, but also allows covalent coupling between the SHAPES reagent and a biotin molecule. We demonstrate that SHAPES-based selection of cDNA–RNA hybrids on streptavidin beads effectively removes the large majority of background signal present in SHAPE probing data and that sequencing-based SHAPES data contain the same amount of RNA structure data as regular sequencing-based SHAPE data obtained through normalization to a no-reagent control. Moreover, the selection efficiently enriches for probed RNAs, suggesting that the SHAPES strategy will be useful for applications with high-background and low-probing signal such as in vivo RNA structure probing. PMID:25805860

Photoactive layer based on T-shaped benzimidazole dyes used for solar cell: from photoelectric properties to molecular design

NASA Astrophysics Data System (ADS)

Xu, Beibei; Li, Yuanzuo; Song, Peng; Ma, Fengcai; Sun, Mengtao

2017-03-01

Three benzimidazole-based organic dyes, possessing the same triphenylamine donors and cyanoacrylic acid acceptors with the bithiophene π-bridges combined in different nuclear positions of benzimidazole, were investigated in the utility of dye-sensitizer solar cells. The structure, molecular orbital and energy, absorption spectra and some important parameters (such as light harvesting efficiency (LHE), electron injection driving force, the electron injection time, chemical reactivity parameters, vertical dipole moment as well as interaction models of dye-I2) were obtained according to Newns-Anderson model and DFT calculation. The process and strength of charge transfer and separation were visualized with charge different density and index of spatial extent (S, D and Δq). Current work paid attention to the new T-shaped dyes to reveal the relation between the structure and photoelectric performance. Furthermore, nine dyes (substitution of alkyl chains and π-bridges) have been designed and characterized to screen promising sensitizer candidates with excellent photo-electronic properties.

Basal Ganglia Shape Abnormalities in the Unaffected Siblings of Schizophrenia Patients

PubMed Central

Mamah, Daniel; Harms, Michael P.; Wang, Lei; Barch, Deanna; Thompson, Paul; Kim, Jaeyun; Miller, Michael I.; Csernansky, John G.

2008-01-01

Objective Abnormalities of basal ganglia structure in schizophrenia have been attributed to the effects of antipsychotic drugs. Our aim was to test the hypothesis that abnormalities of basal ganglia structure are intrinsic features of schizophrenia, by assessing basal ganglia volume and shape in the unaffected siblings of schizophrenia subjects. Method The study involved 25 pairs of schizophrenia subjects and their unaffected siblings and 40 pairs of healthy controls and their siblings. Large deformation, high-dimensional brain mapping was used to obtain surface representations of the caudate, putamen, and globus pallidus. Surfaces were derived from transformations of anatomical templates and shapes were analyzed using reduced-dimensional measures of surface variability (i.e. principal components and canonical analysis). Canonical functions were derived using schizophrenia and control groups, and were then used to compare shapes in the sibling groups. To visualize shape differences, maps of the estimated surface displacement between groups were created. Results In the caudate, putamen and globus pallidus, the degree of shape abnormality observed in the siblings of the schizophrenia subjects was intermediate between the schizophrenia subjects and the controls. In the schizophrenia subjects, significant correlations were observed between measures of caudate, putamen and globus pallidus structure and the selected measures of lifetime psychopathology. Conclusions Attenuated abnormalities of basal ganglia structure are present in the unaffected siblings of schizophrenia subjects. This finding implies that basal ganglia structural abnormalities observed in subjects with schizophrenia are at least in part an intrinsic feature of the illness. PMID:18295189

Image-derived input function with factor analysis and a-priori information.

PubMed

Simončič, Urban; Zanotti-Fregonara, Paolo

2015-02-01

Quantitative PET studies often require the cumbersome and invasive procedure of arterial cannulation to measure the input function. This study sought to minimize the number of necessary blood samples by developing a factor-analysis-based image-derived input function (IDIF) methodology for dynamic PET brain studies. IDIF estimation was performed as follows: (a) carotid and background regions were segmented manually on an early PET time frame; (b) blood-weighted and tissue-weighted time-activity curves (TACs) were extracted with factor analysis; (c) factor analysis results were denoised and scaled using the voxels with the highest blood signal; (d) using population data and one blood sample at 40 min, whole-blood TAC was estimated from postprocessed factor analysis results; and (e) the parent concentration was finally estimated by correcting the whole-blood curve with measured radiometabolite concentrations. The methodology was tested using data from 10 healthy individuals imaged with [(11)C](R)-rolipram. The accuracy of IDIFs was assessed against full arterial sampling by comparing the area under the curve of the input functions and by calculating the total distribution volume (VT). The shape of the image-derived whole-blood TAC matched the reference arterial curves well, and the whole-blood area under the curves were accurately estimated (mean error 1.0±4.3%). The relative Logan-V(T) error was -4.1±6.4%. Compartmental modeling and spectral analysis gave less accurate V(T) results compared with Logan. A factor-analysis-based IDIF for [(11)C](R)-rolipram brain PET studies that relies on a single blood sample and population data can be used for accurate quantification of Logan-V(T) values.

Shape sensitivity analysis of flutter response of a laminated wing

NASA Technical Reports Server (NTRS)

Bergen, Fred D.; Kapania, Rakesh K.

1988-01-01

A method is presented for calculating the shape sensitivity of a wing aeroelastic response with respect to changes in geometric shape. Yates' modified strip method is used in conjunction with Giles' equivalent plate analysis to predict the flutter speed, frequency, and reduced frequency of the wing. Three methods are used to calculate the sensitivity of the eigenvalue. The first method is purely a finite difference calculation of the eigenvalue derivative directly from the solution of the flutter problem corresponding to the two different values of the shape parameters. The second method uses an analytic expression for the eigenvalue sensitivities of a general complex matrix, where the derivatives of the aerodynamic, mass, and stiffness matrices are computed using a finite difference approximation. The third method also uses an analytic expression for the eigenvalue sensitivities, but the aerodynamic matrix is computed analytically. All three methods are found to be in good agreement with each other. The sensitivities of the eigenvalues were used to predict the flutter speed, frequency, and reduced frequency. These approximations were found to be in good agreement with those obtained using a complete reanalysis.

Mechanisms of regulation of cell-mediated immunity. III. The characterization of azobenzenearsonate-specific suppressor T-cell- derived-suppressor factors

PubMed Central

1979-01-01

Delayed type hypersensitivity to the hapten azobenzenearsonate (ABA) can be induced and suppressed by the administration of hapten-coupled syngeneic spleen cells by the appropriate route. Suppressor T cells stimulated by the intravenous administration of ABA-coupled spleen cells have been shown to produce a discrete subcellular factor(s) which is capable of suppressing delayed type hypersensitivity to azobenzenearsonate in the mouse. Such suppressor factors may be produced by the mechanical disruption of suppressor cells or by placing such suppressor cells in culture for 24 h. The suppressor factor(s) (SF) derived from ABA-specific suppressor cells exhibit biological specificity for the suppression of ABA delayed type hypersensitivity (DTH), but not trinitro-phenyl DTH, as well as the capacity to bind to ABA immunoadsorbents. Passage of suppressor factor(s) over reverse immunoadsorbents utilizing a rabbit anti-mouse F(ab')2 antiserum demonstrated that the antigen-specific T-cell derived SF does not bear conventional immunoglobulin markers. The suppressor factor(s) are not immunoglobulin molecules was further demonstrated by the inability of anti-ABA antibodies to suppress ABA DTH. Gel filtration of ABA suppressor factor(s) showed that the majority of the suppressive activity was present in a fraction with molecular weight ranging between 6.8 x 10(4) and 3.3 x 10(4) daltons. We also analyzed for the presence of determinants encoded by the H-2 major histocompatibility complex (MHC) and found that immunoadsorbents prepared utilizing antisera capable of interacting with gene products of the whole or selected gene regions of H-2 MHC, i.e., B10.D2 anti-B10.A and B10 anti- B10.A immunoadsorbents, retained the suppressive activity of ABA-SF. Elution of such columns with glycine HCl buffers (pH 2.8) permitted recovery of specific suppressive activity. Taken collectively such data supports the notion that suppressor T-cell-derived ABA suppressor factors have antigen

Tolerogenic dendritic cells inhibit antiphospholipid syndrome derived effector/memory CD4⁺ T cell response to β2GPI.

PubMed

Torres-Aguilar, Honorio; Blank, Miri; Kivity, Shaye; Misgav, Mudi; Luboshitz, Jacob; Pierangeli, Silvia S; Shoenfeld, Yehuda

2012-01-01

The importance of β(2)-glycoprotein I (β(2)GPI)-specific CD4(+) T cells in the development of pathogenic processes in patients with antiphospholipid syndrome (APS) and APS mouse models is well established. Therefore, our objective is to manipulate the β2GPI specific CD4(+) T cells using tolerogenic dendritic cells (tDCs) to induce tolerance. We aim to evaluate the capability of tDCs to induce antigen-specific tolerance in effector/memory T cells from patients with APS and to elucidate the involved mechanism. DCs and tDCs were produced from patients with APS peripheral-blood-monocytes, using specific cytokines. β(2)GPI-specific tolerance induction was investigated by coculturing control DC (cDC) or tDC, β(2)GPI-loaded, with autologous effector/memory T cells, evaluating the proliferative response, phenotype, cytokines secretion, viability and regulatory T cells. Human monocyte-derived DCs treated with interleukin (IL)-10 and transforming growth factor β-1 (10/TGF-DC) induced β(2)GPI-specific-unresponsiveness in effector/memory CD4(+) T cells (46.5% ± 26.0 less proliferation) in 16 of 20 analysed patients with APS, without affecting the proliferative response to an unrelated candidin. In five analysed patients, 10/TGF-DC-stimulated T cells acquired an IL-2(low)interferon γ(low)IL-10(high) cytokine profile, with just a propensity to express higher numbers of Foxp3(+)CTLA-4(+) cells, but with an evident suppressive ability. In four of 10 analysed patients, 10/TGF-DC-stimulated T cell hyporesponsiveness could not be reverted and showed higher percentages of late apoptosis, p<0.02. The inherent tolerance induction resistance of activated T cells present during the development of autoimmune diseases has delayed the application of tDC as an alternative therapy. This study highlights the 10/TGF-DC feasibility to induce antigen-specific unresponsiveness in autoreactive T cells generated in patients with APS by inducing apoptosis or T cells with regulatory abilities.

T3 Regulates a Human Macrophage-Derived TSH-β Splice Variant: Implications for Human Bone Biology.

PubMed

Baliram, R; Latif, R; Morshed, S A; Zaidi, M; Davies, T F

2016-09-01

TSH and thyroid hormones (T3 and T4) are intimately involved in bone biology. We have previously reported the presence of a murine TSH-β splice variant (TSH-βv) expressed specifically in bone marrow-derived macrophages and that exerted an osteoprotective effect by inducing osteoblastogenesis. To extend this observation and its relevance to human bone biology, we set out to identify and characterize a TSH-β variant in human macrophages. Real-time PCR analyses using human TSH-β-specific primers identified a 364-bp product in macrophages, bone marrow, and peripheral blood mononuclear cells that was sequence verified and was homologous to a human TSH-βv previously reported. We then examined TSH-βv regulation using the THP-1 human monocyte cell line matured into macrophages. After 4 days, 46.1% of the THP-1 cells expressed the macrophage markers CD-14 and macrophage colony-stimulating factor and exhibited typical morphological characteristics of macrophages. Real-time PCR analyses of these cells treated in a dose-dependent manner with T3 showed a 14-fold induction of human TSH-βv mRNA and variant protein. Furthermore, these human TSH-βv-positive cells, induced by T3 exposure, had categorized into both M1 and M2 macrophage phenotypes as evidenced by the expression of macrophage colony-stimulating factor for M1 and CCL-22 for M2. These data indicate that in hyperthyroidism, bone marrow resident macrophages have the potential to exert enhanced osteoprotective effects by oversecreting human TSH-βv, which may exert its local osteoprotective role via osteoblast and osteoclast TSH receptors.

Mass production of shaped particles through vortex ring freezing

NASA Astrophysics Data System (ADS)

An, Duo; Warning, Alex; Yancey, Kenneth G.; Chang, Chun-Ti; Kern, Vanessa R.; Datta, Ashim K.; Steen, Paul H.; Luo, Dan; Ma, Minglin

2016-08-01

A vortex ring is a torus-shaped fluidic vortex. During its formation, the fluid experiences a rich variety of intriguing geometrical intermediates from spherical to toroidal. Here we show that these constantly changing intermediates can be `frozen' at controlled time points into particles with various unusual and unprecedented shapes. These novel vortex ring-derived particles, are mass-produced by employing a simple and inexpensive electrospraying technique, with their sizes well controlled from hundreds of microns to millimetres. Guided further by theoretical analyses and a laminar multiphase fluid flow simulation, we show that this freezing approach is applicable to a broad range of materials from organic polysaccharides to inorganic nanoparticles. We demonstrate the unique advantages of these vortex ring-derived particles in several applications including cell encapsulation, three-dimensional cell culture, and cell-free protein production. Moreover, compartmentalization and ordered-structures composed of these novel particles are all achieved, creating opportunities to engineer more sophisticated hierarchical materials.

Mass production of shaped particles through vortex ring freezing

PubMed Central

An, Duo; Warning, Alex; Yancey, Kenneth G.; Chang, Chun-Ti; Kern, Vanessa R.; Datta, Ashim K.; Steen, Paul H.; Luo, Dan; Ma, Minglin

2016-01-01

A vortex ring is a torus-shaped fluidic vortex. During its formation, the fluid experiences a rich variety of intriguing geometrical intermediates from spherical to toroidal. Here we show that these constantly changing intermediates can be ‘frozen' at controlled time points into particles with various unusual and unprecedented shapes. These novel vortex ring-derived particles, are mass-produced by employing a simple and inexpensive electrospraying technique, with their sizes well controlled from hundreds of microns to millimetres. Guided further by theoretical analyses and a laminar multiphase fluid flow simulation, we show that this freezing approach is applicable to a broad range of materials from organic polysaccharides to inorganic nanoparticles. We demonstrate the unique advantages of these vortex ring-derived particles in several applications including cell encapsulation, three-dimensional cell culture, and cell-free protein production. Moreover, compartmentalization and ordered-structures composed of these novel particles are all achieved, creating opportunities to engineer more sophisticated hierarchical materials. PMID:27488831

Kirkwood-Buff integrals of finite systems: shape effects

NASA Astrophysics Data System (ADS)

Dawass, Noura; Krüger, Peter; Simon, Jean-Marc; Vlugt, Thijs J. H.

2018-06-01

The Kirkwood-Buff (KB) theory provides an important connection between microscopic density fluctuations in liquids and macroscopic properties. Recently, Krüger et al. derived equations for KB integrals for finite subvolumes embedded in a reservoir. Using molecular simulation of finite systems, KB integrals can be computed either from density fluctuations inside such subvolumes, or from integrals of radial distribution functions (RDFs). Here, based on the second approach, we establish a framework to compute KB integrals for subvolumes with arbitrary convex shapes. This requires a geometric function w(x) which depends on the shape of the subvolume, and the relative position inside the subvolume. We present a numerical method to compute w(x) based on Umbrella Sampling Monte Carlo (MC). We compute KB integrals of a liquid with a model RDF for subvolumes with different shapes. KB integrals approach the thermodynamic limit in the same way: for sufficiently large volumes, KB integrals are a linear function of area over volume, which is independent of the shape of the subvolume.

Cloaking of arbitrarily shaped objects with homogeneous coatings

NASA Astrophysics Data System (ADS)

Forestiere, Carlo; Dal Negro, Luca; Miano, Giovanni

2014-05-01

We present a theory for the cloaking of arbitrarily shaped objects and demonstrate electromagnetic scattering cancellation through designed homogeneous coatings. First, in the small-particle limit, we expand the dipole moment of a coated object in terms of its resonant modes. By zeroing the numerator of the resulting rational function, we accurately predict the permittivity values of the coating layer that abates the total scattered power. Then, we extend the applicability of the method beyond the small-particle limit, deriving the radiation corrections of the scattering-cancellation permittivity within a perturbation approach. Our method permits the design of invisibility cloaks for irregularly shaped devices such as complex sensors and detectors.

Optical properties of mineral dust aerosol including analysis of particle size, composition, and shape effects, and the impact of physical and chemical processing

NASA Astrophysics Data System (ADS)

Alexander, Jennifer Mary

Atmospheric mineral dust has a large impact on the earth's radiation balance and climate. The radiative effects of mineral dust depend on factors including, particle size, shape, and composition which can all be extremely complex. Mineral dust particles are typically irregular in shape and can include sharp edges, voids, and fine scale surface roughness. Particle shape can also depend on the type of mineral and can vary as a function of particle size. In addition, atmospheric mineral dust is a complex mixture of different minerals as well as other, possibly organic, components that have been mixed in while these particles are suspended in the atmosphere. Aerosol optical properties are investigated in this work, including studies of the effect of particle size, shape, and composition on the infrared (IR) extinction and visible scattering properties in order to achieve more accurate modeling methods. Studies of particle shape effects on dust optical properties for single component mineral samples of silicate clay and diatomaceous earth are carried out here first. Experimental measurements are modeled using T-matrix theory in a uniform spheroid approximation. Previous efforts to simulate the measured optical properties of silicate clay, using models that assumed particle shape was independent of particle size, have achieved only limited success. However, a model which accounts for a correlation between particle size and shape for the silicate clays offers a large improvement over earlier modeling approaches. Diatomaceous earth is also studied as an example of a single component mineral dust aerosol with extreme particle shapes. A particle shape distribution, determined by fitting the experimental IR extinction data, used as a basis for modeling the visible light scattering properties. While the visible simulations show only modestly good agreement with the scattering data, the fits are generally better than those obtained using more commonly invoked particle shape

Prospectively Predicting Dietary Restraint: The Role of Interpersonal Self-Efficacy, Weight/Shape Self-Efficacy, and Interpersonal Stress

PubMed Central

Cain, A.S.; Bardone-Cone, A.M.; Abramson, L.Y.; Vohs, K.D.; Joiner, T.E.

2009-01-01

Objective This study investigated how the precursors of interpersonal self-efficacy and weight/shape self-efficacy would interact in the face of interpersonal stress to prospectively predict dietary restraint. Three models were explored, each with a different type of interpersonal stress: stress from same sex friendships, opposite sex friendships, or romantic relationships. Method At Time 1 (T1), participants (N = 406) reported on their typical levels of interpersonal self-efficacy and weight/shape self-efficacy, and recent (past 28 days) dietary restraint. At Time 2 (T2), 11 weeks after T1, participants reported on their recent (past 28 days) levels of dietary restraint at that time. Between T1 and T2, participants completed inventories weekly on the previous week’s interpersonal stressors. Results Consistent with prediction, low interpersonal self-efficacy and high weight/shape self-efficacy combined with high interpersonal stress (whether from same sex friendships, opposite sex friendships, or romantic relationships) to predict the highest levels of T2 dietary restraint after controlling for T1 levels. Conclusion These results further link the interpersonal domain with dietary restraint and elucidate characteristics of women particularly apt to increase dietary restraint in response to interpersonal stress. PMID:19718670

Superordinate Shape Classification Using Natural Shape Statistics

ERIC Educational Resources Information Center

Wilder, John; Feldman, Jacob; Singh, Manish

2011-01-01

This paper investigates the classification of shapes into broad natural categories such as "animal" or "leaf". We asked whether such coarse classifications can be achieved by a simple statistical classification of the shape skeleton. We surveyed databases of natural shapes, extracting shape skeletons and tabulating their…

Mid-infrared emission in InxGa1-xAs/GaAs T-shaped quantum wire lasers and its indium composition dependence

NASA Astrophysics Data System (ADS)

Ridene, Said

2018-03-01

In this work, the emission wavelength has been extended out to 1.3, 1.5, and 2.2 μm for InxGa1-xAs/GaAs T-shaped quantum wire (TQWR) using multi-band k.p model and variational formalism. We have investigated the impact of the indium composition on the performance of a series of TQWR through a calculation of the optical gain and transition energies. It is found that the optical gain and the emission wavelength are more influenced taking into account the effect of the indium concentration and persisted up at room temperature (RT). The results could open the way to the development of laser communication systems operating at long wavelengths and fabricated from TQWRs structure.

ME-10TUMOR MICROENVIRONMENT INFILTRATING MYELOID DERIVED SUPPRESSOR CELLS INHIBIT ANTI-TUMOR T CELL RESPONSES

PubMed Central

Kamran, Neha; Ayala, Mariela; Li, Youping; Assi, Hikmat; Candolfi, Marianela; Dzaman, Marta; Lowenstein, Pedro; Castro, Maria

2014-01-01

MDSCs represent a population of immature myeloid cells at various stages of differentiation that inhibit anti-tumor T cell-mediated responses. We demonstrate the accumulation of MDSCs in GL26 induced glioma and B16 melanoma bearing mice. Absolute numbers of Ly-6G+ (Gr-1high) MDSCs showed a 200 fold increase within the tumor microenvironment (TME) 28 days post-tumor implantation. The numbers of Ly-6C+ (Gr-1low) MDSCs also showed a similar trend within the TME. While this massive influx of MDSCs was noted within intracranial tumors, MDSC levels did not increase in the dLNs, spleen or bone marrow (BM) of intracranial tumor bearing mice. MDSCs numbers were significantly elevated in the blood of GL26 intracranial tumor bearing mice at 28 days. Mice bearing B16 tumors in the flank showed a ∼5 fold increased influx of Ly-6G+ MDSCs while the Ly6C+ MDSCs increased marginally by 1.1 fold within the tumor mass. Levels of circulating MDSCs also increased by ∼10 fold, while the levels of splenic MDSCs did not change. While both Ly-6G+ and Ly6C+ MDSCs isolated from the brain TME of GL26 intracranial tumor bearing mice inhibited antigen-specific T cell proliferation, Ly6C+ MDSC were found to be more efficient. Ly6G+ or Ly6C+ MDSCs from the bone marrow of intracranial tumor bearing mice failed to suppress antigen-specific T cell proliferation. Splenic and bone marrow MDSCs from naïve mice also did not inhibit antigen-specific T cell proliferation suggesting that TME derived factors may activate MDSCs to exert their immune-suppressive properties. Microarray analysis of glioma cell lines showed elevated levels of CXCL1 mRNA and splenic MDSCs from GL26 tumor mice showed upregulation of the CXCR2 mRNA. Preliminary experiments indicate that CXCR2 signaling mediates MDSC chemotaxis. Overall, our data suggests that strategies that inhibit MDSC recruitment to the TME and/or block their activity could enhance the T cell mediated tumor clearance.

α7 Nicotinic Acetylcholine Receptor (α7nAChR) Expression in Bone Marrow–Derived Non–T Cells Is Required for the Inflammatory Reflex

PubMed Central

Olofsson, Peder S; Katz, David A; Rosas-Ballina, Mauricio; Levine, Yaakov A; Ochani, Mahendar; Valdés-Ferrer, Sergio I; Pavlov, Valentin A; Tracey, Kevin J; Chavan, Sangeeta S

2012-01-01

The immune response to infection or injury coordinates host defense and tissue repair, but also has the capacity to damage host tissues. Recent advances in understanding protective mechanisms have found neural circuits that suppress release of damaging cytokines. Stimulation of the vagus nerve protects from excessive cytokine production and ameliorates experimental inflammatory disease. This mechanism, the inflammatory reflex, requires the α7 nicotinic acetylcholine receptor (α7nAChR), a ligand-gated ion channel expressed on macrophages, lymphocytes, neurons and other cells. To investigate cell-specific function of α7nAChR in the inflammatory reflex, we created chimeric mice by cross-transferring bone marrow between wild-type (WT) and α7nAChR-deficient mice. Deficiency of α7nAChR in bone marrow–derived cells significantly impaired vagus nerve–mediated regulation of tumor necrosis factor (TNF), whereas α7nAChR deficiency in neurons and other cells had no significant effect. In agreement with recent work, the inflammatory reflex was not functional in nude mice, because functional T cells are required for the integrity of the pathway. To investigate the role of T-cell α7nAChR, we adoptively transferred α7nAChR-deficient or WT T cells to nude mice. Transfer of WT and α7nAChR-deficient T cells restored function, indicating that α7nAChR expression on T cells is not necessary for this pathway. Together, these results indicate that α7nAChR expression in bone marrow–derived non–T cells is required for the integrity of the inflammatory reflex. PMID:22183893

Thymus-Derived Regulatory T Cell Development Is Regulated by C-Type Lectin-Mediated BIC/MicroRNA 155 Expression

PubMed Central

Sánchez-Díaz, Raquel; Blanco-Dominguez, Rafael; Lasarte, Sandra; Tsilingiri, Katerina; Martín-Gayo, Enrique; Linillos-Pradillo, Beatriz; de la Fuente, Hortensia; Sánchez-Madrid, Francisco; Nakagawa, Rinako; Toribio, María L.

2017-01-01

ABSTRACT Thymus-derived regulatory T (tTreg) cells are key to preventing autoimmune diseases, but the mechanisms involved in their development remain unsolved. Here, we show that the C-type lectin receptor CD69 controls tTreg cell development and peripheral Treg cell homeostasis through the regulation of BIC/microRNA 155 (miR-155) and its target, suppressor of cytokine signaling 1 (SOCS-1). Using Foxp3-mRFP/cd69+/− or Foxp3-mRFP/cd69−/− reporter mice and short hairpin RNA (shRNA)-mediated silencing and miR-155 transfection approaches, we found that CD69 deficiency impaired the signal transducer and activator of transcription 5 (STAT5) pathway in Foxp3+ cells. This results in BIC/miR-155 inhibition, increased SOCS-1 expression, and severely impaired tTreg cell development in embryos, adults, and Rag2−/− γc−/− hematopoietic chimeras reconstituted with cd69−/− stem cells. Accordingly, mirn155−/− mice have an impaired development of CD69+ tTreg cells and overexpression of the miR-155-induced CD69 pathway, suggesting that both molecules might be concomitantly activated in a positive-feedback loop. Moreover, in vitro-inducible CD25+ Treg (iTreg) cell development is inhibited in Il2rγ−/−/cd69−/− mice. Our data highlight the contribution of CD69 as a nonredundant key regulator of BIC/miR-155-dependent Treg cell development and homeostasis. PMID:28167605

Predicting ozone profile shape from satellite UV spectra

NASA Astrophysics Data System (ADS)

Xu, Jian; Loyola, Diego; Romahn, Fabian; Doicu, Adrian

2017-04-01

Identifying ozone profile shape is a critical yet challenging job for the accurate reconstruction of vertical distributions of atmospheric ozone that is relevant to climate change and air quality. Motivated by the need to develop an approach to reliably and efficiently estimate vertical information of ozone and inspired by the success of machine learning techniques, this work proposes a new algorithm for deriving ozone profile shapes from ultraviolet (UV) absorption spectra that are recorded by satellite instruments, e.g. GOME series and the future Sentinel missions. The proposed algorithm formulates this particular inverse problem in a classification framework rather than a conventional inversion one and places an emphasis on effectively characterizing various profile shapes based on machine learning techniques. Furthermore, a comparison of the ozone profiles from real GOME-2 data estimated by our algorithm and the classical retrieval algorithm (Optimal Estimation Method) is performed.

Study on shape recovery speed of SMP, SMP composite, and SMP foam

NASA Astrophysics Data System (ADS)

Wu, Xuelian; Liu, Yanju; Leng, Jinsong

2008-03-01

Shape memory polymer (SMP) receives increasing attention along with its derivants - SMP composite and SMP foam in recent years. In this paper, after fabricating thermoset styrene-based SMP, SMP/carbon black (CB) composite and SMP foam, we studied their shape recovery speed in bending. Different from those reported in the literature, we propose a new approach, i.e., using infrared light, for actuating SMP materials for shape recovery. The results show that SMP, SMP/CB composite and SMP foam can recover to their original shape perfectly in a wide temperature range. Shape recovery speed of SMP composite is not uniform during the overall recovery process, and it is the same trend with SMP but not prominent with SMP foam. Repeatability of shape recovery speed for styrene-based SMP and SMP/CB composite are similarly stable and the former is the better, but it is so worse for SMP foam. Temperature-dependent of shape recovery speed test for styrene-based SMP and SMP/CB composite reveal that higher temperature increases their shape recovery speed.

Revealing the glass transition in shape memory polymers using Brillouin spectroscopy.

PubMed

Steelman, Zachary A; Weems, Andrew C; Traverso, Andrew J; Szafron, Jason M; Maitland, Duncan J; Yakovlev, Vladislav V

2017-12-11

Emerging medical devices which employ shape memory polymers (SMPs) require precise measurements of the glass transition temperature (T g ) to ensure highly controlled shape recovery kinetics. Conventional techniques like differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) have limitations that prevent utilization for certain devices, including limited accuracy and the need for sacrificial samples. In this report, we employ an approach based on Brillouin spectroscopy to probe the glass transition of SMPs rapidly, remotely, and nondestructively. Further, we compare the T g obtained from Brillouin scattering with DMA- and DSC-measured T g to demonstrate the accuracy of Brillouin scattering for this application. We conclude that Brillouin spectroscopy is an accurate technique for obtaining the glass transition temperature of SMPs, aligning closely with the most common laboratory standards while providing a rapid, remote, and nondestructive method for the analysis of unique polymeric medical devices.

Stationary Temperature Distribution in a Rotating Ring-Shaped Target

NASA Astrophysics Data System (ADS)

Kazarinov, N. Yu.; Gulbekyan, G. G.; Kazacha, V. I.

2018-05-01

For a rotating ring-shaped target irradiated by a heavy-ion beam, a differential equation for computing the stationary distribution of the temperature averaged over the cross section is derived. The ion-beam diameter is assumed to be equal to the ring width. Solving this equation allows one to obtain the stationary temperature distribution along the ring-shaped target depending on the ion-beam, target, and cooling-gas parameters. Predictions are obtained for the rotating target to be installed at the DC-280 cyclotron. For an existing rotating target irradiated by an ion beam, our predictions are compared with the measured temperature distribution.

Sulfolobus Spindle-Shaped Virus 1 Contains Glycosylated Capsid Proteins, a Cellular Chromatin Protein, and Host-Derived Lipids

PubMed Central

Quemin, Emmanuelle R. J.; Pietilä, Maija K.; Oksanen, Hanna M.; Forterre, Patrick; Rijpstra, W. Irene C.; Schouten, Stefan; Bamford, Dennis H.; Prangishvili, David

2015-01-01

ABSTRACT Geothermal and hypersaline environments are rich in virus-like particles, among which spindle-shaped morphotypes dominate. Currently, viruses with spindle- or lemon-shaped virions are exclusive to Archaea and belong to two distinct viral families. The larger of the two families, the Fuselloviridae, comprises tail-less, spindle-shaped viruses, which infect hosts from phylogenetically distant archaeal lineages. Sulfolobus spindle-shaped virus 1 (SSV1) is the best known member of the family and was one of the first hyperthermophilic archaeal viruses to be isolated. SSV1 is an attractive model for understanding virus-host interactions in Archaea; however, the constituents and architecture of SSV1 particles remain only partially characterized. Here, we have conducted an extensive biochemical characterization of highly purified SSV1 virions and identified four virus-encoded structural proteins, VP1 to VP4, as well as one DNA-binding protein of cellular origin. The virion proteins VP1, VP3, and VP4 undergo posttranslational modification by glycosylation, seemingly at multiple sites. VP1 is also proteolytically processed. In addition to the viral DNA-binding protein VP2, we show that viral particles contain the Sulfolobus solfataricus chromatin protein Sso7d. Finally, we provide evidence indicating that SSV1 virions contain glycerol dibiphytanyl glycerol tetraether (GDGT) lipids, resolving a long-standing debate on the presence of lipids within SSV1 virions. A comparison of the contents of lipids isolated from the virus and its host cell suggests that GDGTs are acquired by the virus in a selective manner from the host cytoplasmic membrane, likely during progeny egress. IMPORTANCE Although spindle-shaped viruses represent one of the most prominent viral groups in Archaea, structural data on their virion constituents and architecture still are scarce. The comprehensive biochemical characterization of the hyperthermophilic virus SSV1 presented here brings novel and

CD4+CD62L+ Central Memory T Cells Can Be Converted to Foxp3+ T Cells

PubMed Central

Zhang, Xiaolong; Chang Li, Xian; Xiao, Xiang; Sun, Rui; Tian, Zhigang; Wei, Haiming

2013-01-01

The peripheral Foxp3+ Treg pool consists of naturally arising Treg (nTreg) and adaptive Treg cells (iTreg). It is well known that naive CD4+ T cells can be readily converted to Foxp3+ iTreg in vitro, and memory CD4+ T cells are resistant to conversion. In this study, we investigated the induction of Foxp3+ T cells from various CD4+ T-cell subsets in human peripheral blood. Though naive CD4+ T cells were readily converted to Foxp3+ T cells with TGF-β and IL-2 treatment in vitro, such Foxp3+ T cells did not express the memory marker CD45RO as do Foxp3+ T cells induced in the peripheral blood of Hepatitis B Virus (HBV) patients. Interestingly, a subset of human memory CD4+ T cells, defined as CD62L+ central memory T cells, could be induced by TGF-β to differentiate into Foxp3+ T cells. It is well known that Foxp3+ T cells derived from human CD4+CD25- T cells in vitro are lack suppressive functions. Our data about the suppressive functions of CD4+CD62L+ central memory T cell-derived Foxp3+ T cells support this conception, and an epigenetic analysis of these cells showed a similar methylation pattern in the FOXP3 Treg-specific demethylated region as the naive CD4+ T cell-derived Foxp3+ T cells. But further research showed that mouse CD4+ central memory T cells also could be induced to differentiate into Foxp3+ T cells, such Foxp3+ T cells could suppress the proliferation of effector T cells. Thus, our study identified CD4+CD62L+ central memory T cells as a novel potential source of iTreg. PMID:24155942

Examination of Effective Dielectric Constants Derived from Non-Spherical Melting Hydrometeor

NASA Astrophysics Data System (ADS)

Liao, L.; Meneghini, R.

2009-04-01

radar measurements from melting hydrometeors, it is necessary to move away from the restriction that the melting particles are spherical. In this study, our primary focus is on the derivation of the effective dielectric constants of non-spherical particles that are mixtures of ice and water. The computational model for the ice-water particle is described by a collection of 128x128x128 cubic cells of identical size. Because of the use of such a high-resolution model, the particles can be described accurately not only with regard to shape but with respect to structure as well. The Cartesian components of the mean internal electric field of particles, which are used to infer the effective dielectric constants, are calculated at each cell by the use of the Conjugate Gradient-Fast Fourier Transform (CG-FFT) numerical method. In this work we first check the validity of derived effective dielectric constant from a non-spherical mixed phase particle by comparing the polarimetric scattering parameters of an ice-water spheroid obtained from the CGFFT to those computed from the T-matrix for a homogeneous particle with the same geometry as that of the mixed phase particle (such as size, shape and orientation) and with an effective dielectric constant derived from the internal field of the mixed-phase particle. The accuracy of the effective dielectric constant can be judged by whether the scattering parameters of interest can accurately reproduce those of the exact solution, i.e., the T-matrix results. The purpose of defining an effective dielectric constant is to reduce the complexity of the scattering calculations in the sense that the effective dielectric constant, once obtained, may be applicable to a range of particle sizes, shapes and orientations. Conversely, if a different effective dielectric constant is needed for each particle size or shape, then its utility would be marginal. Having verified that the effective dielectric constant defined for a particular particle with a

VLT/SPHERE observations and shape reconstruction of asteroid (6) Hebe

NASA Astrophysics Data System (ADS)

Marsset, Michael; Carry, Benoit; Dumas, Christophe; Vernazza, Pierre; Jehin, Emmanuel; Sonnett, Sarah M.; Fusco, Thierry

2016-10-01

(6) Hebe is a large main-belt asteroid, accounting for about half a percent of the mass of the asteroid belt. Its spectral characteristics and close proximity to dynamical resonances within the main-belt (the 3:1 Kirkwood gap and the nu6 resonance) make it a probable parent body of the H-chondrites and IIE iron meteorites found on Earth.We present new AO images of Hebe obtained with the high-contrast imager SPHERE (Beuzit et al. 2008) as part of the science verification of the instrument. Hebe was observed close to its opposition date and throughout its rotation in order to derive its 3-D shape, and to allow a study of its surface craters. Our observations reveal impact zones that witness a severe collisional disruption for this asteroid. When combined to previous AO images and available lightcurves (both from the literature and from recent optical observations by our team), these new observations allow us to derive a reliable shape model using our KOALA algorithm (Carry et al. 2010). We further derive an estimate of Hebe's density based on its known astrometric mass.

Sharp and round shapes of seen objects have distinct influences on vowel and consonant articulation.

PubMed

Vainio, L; Tiainen, M; Tiippana, K; Rantala, A; Vainio, M

2017-07-01

The shape and size-related sound symbolism phenomena assume that, for example, the vowel [i] and the consonant [t] are associated with sharp-shaped and small-sized objects, whereas [ɑ] and [m] are associated with round and large objects. It has been proposed that these phenomena are mostly based on the involvement of articulatory processes in representing shape and size properties of objects. For example, [i] might be associated with sharp and small objects, because it is produced by a specific front-close shape of articulators. Nevertheless, very little work has examined whether these object properties indeed have impact on speech sound vocalization. In the present study, the participants were presented with a sharp- or round-shaped object in a small or large size. They were required to pronounce one out of two meaningless speech units (e.g., [i] or [ɑ]) according to the size or shape of the object. We investigated how a task-irrelevant object property (e.g., the shape when responses are made according to size) influences reaction times, accuracy, intensity, fundamental frequency, and formant 1 and formant 2 of vocalizations. The size did not influence vocal responses but shape did. Specifically, the vowel [i] and consonant [t] were vocalized relatively rapidly when the object was sharp-shaped, whereas [u] and [m] were vocalized relatively rapidly when the object was round-shaped. The study supports the view that the shape-related sound symbolism phenomena might reflect mapping of the perceived shape with the corresponding articulatory gestures.

Synovial CD4+ T-cell-derived GM-CSF supports the differentiation of an inflammatory dendritic cell population in rheumatoid arthritis

PubMed Central

Reynolds, G; Gibbon, J R; Pratt, A G; Wood, M J; Coady, D; Raftery, G; Lorenzi, A R; Gray, A; Filer, A; Buckley, C D; Haniffa, M A; Isaacs, J D; Hilkens, C M U

2016-01-01

Objective A population of synovial inflammatory dendritic cells (infDCs) has recently been identified in rheumatoid arthritis (RA) and is thought to be monocyte-derived. Here, we investigated the role and source of granulocyte macrophage-colony-stimulating factor (GM-CSF) in the differentiation of synovial infDC in RA. Methods Production of GM-CSF by peripheral blood (PB) and synovial fluid (SF) CD4+ T cells was assessed by ELISA and flow cytometry. In vitro CD4+ T-cell polarisation experiments were performed with T-cell activating CD2/CD3/CD28-coated beads in the absence or presence of pro-Th1 or pro-Th17 cytokines. CD1c+ DC and CD16+ macrophage subsets were flow-sorted and analysed morphologically and functionally (T-cell stimulatory/polarising capacity). Results RA-SF CD4+ T cells produced abundant GM-CSF upon stimulation and significantly more than RA-SF mononuclear cells depleted of CD4+ T cells. GM-CSF-producing T cells were significantly increased in RA-SF compared with non-RA inflammatory arthritis SF, active RA PB and healthy donor PB. GM-CSF-producing CD4+ T cells were expanded by Th1-promoting but not Th17-promoting conditions. Following coculture with RA-SF CD4+ T cells, but not healthy donor PB CD4+ T cells, a subpopulation of monocytes differentiated into CD1c+ infDC; a process dependent on GM-CSF. These infDC displayed potent alloproliferative capacity and enhanced GM-CSF, interleukin-17 and interferon-γ production by CD4+ T cells. InfDC with an identical phenotype to in vitro generated cells were significantly enriched in RA-SF compared with non-RA-SF/tissue/PB. Conclusions We demonstrate a therapeutically tractable feedback loop of GM-CSF secreted by RA synovial CD4+ T cells promoting the differentiation of infDC with potent capacity to induce GM-CSF-producing CD4+ T cells. PMID:25923217

Caspase-1 from Human Myeloid-Derived Suppressor Cells Can Promote T Cell-Independent Tumor Proliferation.

PubMed

Zeng, Qi; Fu, Juan; Korrer, Michael; Gorbounov, Mikhail; Murray, Peter J; Pardoll, Drew; Masica, David L; Kim, Young J

2018-05-01

Immunosuppressive myeloid-derived suppressive cells (MDSCs) are characterized by their phenotypic and functional heterogeneity. To better define their T cell-independent functions within the tumor, sorted monocytic CD14 + CD11b + HLA-DR low/- MDSCs (mMDSC) from squamous cell carcinoma patients showed upregulated caspase-1 activity, which was associated with increased IL1β and IL18 expression. In vitro studies demonstrated that mMDSCs promoted caspase-1-dependent proliferation of multiple squamous carcinoma cell lines in both human and murine systems. In vivo , growth rates of B16, MOC1, and Panc02 were significantly blunted in chimeric mice adoptively transferred with caspase-1 null bone marrow cells under T cell-depleted conditions. Adoptive transfer of wild-type Gr-1 + CD11b + MDSCs from tumor-bearing mice reversed this antitumor response, whereas caspase-1 inhibiting thalidomide-treated MDSCs phenocopied the antitumor response found in caspase-1 null mice. We further hypothesized that MDSC caspase-1 activity could promote tumor-intrinsic MyD88-dependent carcinogenesis. In mice with wild-type caspase-1, MyD88-silenced tumors displayed reduced growth rate, but in chimeric mice with caspase-1 null bone marrow cells, MyD88-silenced tumors did not display differential tumor growth rate. When we queried the TCGA database, we found that caspase-1 expression is correlated with overall survival in squamous cell carcinoma patients. Taken together, our findings demonstrated that caspase-1 in MDSCs is a direct T cell-independent mediator of tumor proliferation. Cancer Immunol Res; 6(5); 566-77. ©2018 AACR . ©2018 American Association for Cancer Research.

Effects of contact shape on the scaling of biological attachments

NASA Astrophysics Data System (ADS)

Spolenak, Ralph; Gorb, Stanislav; Gao, Huajian; Arzt, Eduard

2005-02-01

Adhesion of biological systems has recently received much research attention: the survival of organisms ranging from single cells and mussels to insects, spiders and geckos relies crucially on their mechanical interaction with their environments. For spiders, lizards and possible other 'dry' adhesive systems, explanations for adhesion are based on van der Waals interaction, and the adhesion of single-contact elements has been described by the classical Johnson-Kendall-Roberts (JKR) model derived for spherical contacts. However, real biological contacts display a variety of shapes and only rarely resemble a hemisphere. Here, we theoretically assess the influence of various contact shapes on the pull-off force for single contacts as well as their scaling potential in contact arrays. It is concluded that other shapes, such as a toroidal contact geometry, should lead to better attachment; such geometries are observed in our microscopic investigations of hair-tip shapes in beetles and flies.

Comparison of solid shapes geometry derived by a laser scanner and a total station

NASA Astrophysics Data System (ADS)

Sidiropoulos, Andreas; Lakakis, Konstantinos

2016-08-01

The laser scanning technology has become a common method for the daily applications of a large variety of scientists and professionals. Even for more sophisticated projects, laser scanners have been proved a very useful tool at researchers' and engineers' disposal. In this paper, we investigated the ability of a laser scanner compared to the ability of a total station to provide the geometry of solids. The tests were made in the laboratory facilities of the Aristotle University of Thessaloniki, in a variety of distances between the measuring instrument and the object. The solids that were used differ in shape, material and color. The objects are a wooden cube, a metal cube and a wooden pyramid. The absolute dimensions of the solid shapes were provided by the use of a caliper and were compared to the dimensions that were calculated by the coordinates produced by the total station and laser scanner measurements.

Design of Feedforward Controller to Reduce Force Ripple for Linear Motor using Halbach Magnet Array with T Shape Magnet

NASA Astrophysics Data System (ADS)

Kim, Moojong; Kim, Jinyoung; Lee, Moon G.

Recently, in micro/nano fabrication equipments, linear motors are widely used as an actuator to position workpiece, machining tool and measurement head. To control them faster and more precise, the motor should have high actuating force and small force ripple. High actuating force enable us to more workpiece with high acceleration. Eventually, it may provide higher throughput. Force ripple gives detrimental effect on the precision and tracking performance of the equipments. In order to accomplish more precise motion, it is important to make lower the force ripple. Force ripple is categorized into cogging and mutual ripple. First is dependent on the shape of magnets and/or core. The second is not dependent on them but dependent on current commutation. In this work, coreless mover i.e. coil winding is applied to the linear motor to avoid the cogging ripple. Therefore, the mutual ripple is only considered to be minimized. Ideal Halbach magnet array has continuously varying magnetization. The THMA (Halbach magnet array with T shape magnets) is proposed to approximate the ideal one. The THMA can not produce ideal sinusoidal flux, therefore, the linear motor with THMA and sinusoidal commutation of current generates the mutual force ripple. In this paper, in order to compensate mutual force ripple by feedforward(FF) controller, we calculate the optimized commutation of input current. The ripple is lower than 1.17% of actuating force if the commutation current agree with the magnetic flux from THMA. The performance of feedforward(FF) controller is verified by experiment.

Modeling the behaviour of shape memory materials under large deformations

NASA Astrophysics Data System (ADS)

Rogovoy, A. A.; Stolbova, O. S.

2017-06-01

In this study, the models describing the behavior of shape memory alloys, ferromagnetic materials and polymers have been constructed, using a formalized approach to develop the constitutive equations for complex media under large deformations. The kinematic and constitutive equations, satisfying the principles of thermodynamics and objectivity, have been derived. The application of the Galerkin procedure to the systems of equations of solid mechanics allowed us to obtain the Lagrange variational equation and variational formulation of the magnetostatics problems. These relations have been tested in the context of the problems of finite deformation in shape memory alloys and ferromagnetic materials during forward and reverse martensitic transformations and in shape memory polymers during forward and reverse relaxation transitions from a highly elastic to a glassy state.

Superior haptic-to-visual shape matching in autism spectrum disorders.

PubMed

Nakano, Tamami; Kato, Nobumasa; Kitazawa, Shigeru

2012-04-01

A weak central coherence theory in autism spectrum disorder (ASD) proposes that a cognitive bias toward local processing in ASD derives from a weakness in integrating local elements into a coherent whole. Using this theory, we hypothesized that shape perception through active touch, which requires sequential integration of sensorimotor traces of exploratory finger movements into a shape representation, would be impaired in ASD. Contrary to our expectation, adults with ASD showed superior performance in a haptic-to-visual delayed shape-matching task compared to adults without ASD. Accuracy in discriminating haptic lengths or haptic orientations, which lies within the somatosensory modality, did not differ between adults with ASD and adults without ASD. Moreover, this superior ability in inter-modal haptic-to-visual shape matching was not explained by the score in a unimodal visuospatial rotation task. These results suggest that individuals with ASD are not impaired in integrating sensorimotor traces into a global visual shape and that their multimodal shape representations and haptic-to-visual information transfer are more accurate than those of individuals without ASD. Copyright © 2012 Elsevier Ltd. All rights reserved.

Seeing the tipping point: Balance perception and visual shape.

PubMed

Firestone, Chaz; Keil, Frank C

2016-07-01

In a brief glance at an object or shape, we can appreciate a rich suite of its functional properties, including the organization of the object's parts, its optimal contact points for grasping, and its center of mass, or balancing point. However, in the real world and the laboratory, balance perception shows systematic biases whereby observers may misjudge a shape's center of mass by a severe margin. Are such biases simply quirks of physical reasoning? Or might they instead reflect more fundamental principles of object representation? Here we demonstrate systematically biased center-of-mass estimation for two-dimensional (2D) shapes (Study 1) and advance a surprising explanation of such biases. We suggest that the mind implicitly represents ordinary 2D shapes as rich, volumetric, three-dimensional (3D) objects, and that these "inflated" shape representations intrude on and bias perception of the 2D shape's geometric properties. Such "inflation" is a computer-graphics technique for segmenting shapes into parts, and we show that a model derived from this technique best accounts for the biases in center-of-mass estimation in Study 1. Further supporting this account, we show that reducing the need for inflated shape representations diminishes such biases: Center-of-mass estimation improved when cues to shapehood were attenuated (Study 2) and when shapes' depths were explicitly depicted using real-life objects laser-cut from wood (Study 3). We suggest that the technique of shape inflation is actually implemented in the mind; thus, biases in our impressions of balance reflect a more general functional characteristic of object perception. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

MicroRNA-31 negatively regulates peripherally derived regulatory T-cell generation by repressing retinoic acid-inducible protein 3

PubMed Central

Zhang, Lingyun; Ke, Fang; Liu, Zhaoyuan; Bai, Jing; Liu, Jinlin; Yan, Sha; Xu, Zhenyao; Lou, Fangzhou; Wang, Hong; Zhu, Huiyuan; Sun, Yang; Cai, Wei; Gao, Yuanyuan; Li, Qun; Yu, Xue-Zhong; Qian, Youcun; Hua, Zichun; Deng, Jiong; Li, Qi-Jing; Wang, Honglin

2015-01-01

Peripherally derived regulatory T (pTreg) cell generation requires T-cell receptor (TCR) signalling and the cytokines TGF-β1 and IL-2. Here we show that TCR signalling induces the microRNA miR-31, which negatively regulates pTreg-cell generation. miR-31 conditional deletion results in enhanced induction of pTreg cells, and decreased severity of experimental autoimmune encephalomyelitis (EAE). Unexpectedly, we identify Gprc5a as a direct target of miR-31. Gprc5a is known as retinoic acid-inducible protein 3, and its deficiency leads to impaired pTreg-cell induction and increased EAE severity. By generating miR-31 and Gprc5a double knockout mice, we show that miR-31 promotes the development of EAE through inhibiting Gprc5a. Thus, our data identify miR-31 and its target Gprc5a as critical regulators for pTreg-cell generation, suggesting a previously unrecognized epigenetic mechanism for dysfunctional Treg cells in autoimmune diseases. PMID:26165721

Fish-derived nutrient hotspots shape coral reef benthic communities.

PubMed

Shantz, Andrew A; Ladd, Mark C; Schrack, Elizabeth; Burkepile, Deron E

2015-12-01

Animal-derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt-derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top-tier predators. Furthermore, our results suggest that

A shape dynamical approach to holographic renormalization

NASA Astrophysics Data System (ADS)

Gomes, Henrique; Gryb, Sean; Koslowski, Tim; Mercati, Flavio; Smolin, Lee

2015-01-01

We provide a bottom-up argument to derive some known results from holographic renormalization using the classical bulk-bulk equivalence of General Relativity and Shape Dynamics, a theory with spatial conformal (Weyl) invariance. The purpose of this paper is twofold: (1) to advertise the simple classical mechanism, trading off gauge symmetries, that underlies the bulk-bulk equivalence of General Relativity and Shape Dynamics to readers interested in dualities of the type of AdS/conformal field theory (CFT); and (2) to highlight that this mechanism can be used to explain certain results of holographic renormalization, providing an alternative to the AdS/CFT conjecture for these cases. To make contact with the usual semiclassical AdS/CFT correspondence, we provide, in addition, a heuristic argument that makes it plausible that the classical equivalence between General Relativity and Shape Dynamics turns into a duality between radial evolution in gravity and the renormalization group flow of a CFT. We believe that Shape Dynamics provides a new perspective on gravity by giving conformal structure a primary role within the theory. It is hoped that this work provides the first steps toward understanding what this new perspective may be able to teach us about holographic dualities.

Skin injury model classification based on shape vector analysis

PubMed Central

2012-01-01

Background: Skin injuries can be crucial in judicial decision making. Forensic experts base their classification on subjective opinions. This study investigates whether known classes of simulated skin injuries are correctly classified statistically based on 3D surface models and derived numerical shape descriptors. Methods: Skin injury surface characteristics are simulated with plasticine. Six injury classes – abrasions, incised wounds, gunshot entry wounds, smooth and textured strangulation marks as well as patterned injuries - with 18 instances each are used for a k-fold cross validation with six partitions. Deformed plasticine models are captured with a 3D surface scanner. Mean curvature is estimated for each polygon surface vertex. Subsequently, distance distributions and derived aspect ratios, convex hulls, concentric spheres, hyperbolic points and Fourier transforms are used to generate 1284-dimensional shape vectors. Subsequent descriptor reduction maximizing SNR (signal-to-noise ratio) result in an average of 41 descriptors (varying across k-folds). With non-normal multivariate distribution of heteroskedastic data, requirements for LDA (linear discriminant analysis) are not met. Thus, shrinkage parameters of RDA (regularized discriminant analysis) are optimized yielding a best performance with λ = 0.99 and γ = 0.001. Results: Receiver Operating Characteristic of a descriptive RDA yields an ideal Area Under the Curve of 1.0for all six categories. Predictive RDA results in an average CRR (correct recognition rate) of 97,22% under a 6 partition k-fold. Adding uniform noise within the range of one standard deviation degrades the average CRR to 71,3%. Conclusions: Digitized 3D surface shape data can be used to automatically classify idealized shape models of simulated skin injuries. Deriving some well established descriptors such as histograms, saddle shape of hyperbolic points or convex hulls with subsequent reduction of dimensionality while maximizing SNR

Acoustic field of a wedge-shaped section of a spherical cap transducer

NASA Astrophysics Data System (ADS)

Ketterling, Jeffrey A.

2003-12-01

The acoustic pressure field at an arbitrary point in space is derived for a wedge-shaped section of a spherical cap transducer using the spatial impulse response (SIR) method. For a spherical surface centered at the origin, a wedge shape is created by taking cuts in the X-Y and X-Z planes and removing the smallest surface component. Analytic expressions are derived for the SIR based on spatial location. The expressions utilize the SIR solutions for a spherical cap transducer [Arditi et al., Ultrason. Imaging 3, 37-61 (1981)] with additional terms added to account for the reduced surface area of the wedge. Results from the numerical model are compared to experimental measurements from a wedge transducer with an 8-cm outer diameter and 9-cm geometric focus. The experimental and theoretical -3-dB beamwidths agreed to within 10%+/-5%. The SIR model for a wedge-shaped transducer is easily extended to other spherically curved transducer geometries that consist of combinations of wedge sections and spherical caps.

Acoustic field of a wedge-shaped section of a spherical cap transducer.

PubMed

Ketterling, Jeffrey A

2003-12-01

The acoustic pressure field at an arbitrary point in space is derived for a wedge-shaped section of a spherical cap transducer using the spatial impulse response (SIR) method. For a spherical surface centered at the origin, a wedge shape is created by taking cuts in the X-Y and X-Z planes and removing the smallest surface component. Analytic expressions are derived for the SIR based on spatial location. The expressions utilize the SIR solutions for a spherical cap transducer [Arditi et al., Ultrason. Imaging 3, 37-61 (1981)] with additional terms added to account for the reduced surface area of the wedge. Results from the numerical model are compared to experimental measurements from a wedge transducer with an 8-cm outer diameter and 9-cm geometric focus. The experimental and theoretical -3-dB beamwidths agreed to within 10% +/- 5%. The SIR model for a wedge-shaped transducer is easily extended to other spherically curved transducer geometries that consist of combinations of wedge sections and spherical caps.

Shape evolution of 72,74Kr with temperature in covariant density functional theory

NASA Astrophysics Data System (ADS)

Zhang, Wei; Niu, Yi-Fei

2017-09-01

The rich phenomena of deformations in neutron-deficient krypton isotopes, such as shape evolution with neutron number and shape coexistence, have attracted the interest of nuclear physicists for decades. It is interesting to study such shape phenomena using a novel way, e.g. by thermally exciting the nucleus. In this work, we develop the finite temperature covariant density functional theory for axially deformed nuclei with the treatment of pairing correlations by the BCS approach, and apply this approach for the study of shape evolution in 72,74Kr with increasing temperature. For 72Kr, with temperature increasing, the nucleus firstly experiences a relatively quick weakening in oblate deformation at temperature T ˜0.9 MeV, and then changes from oblate to spherical at T ˜2.1 MeV. For 74Kr, its global minimum is at quadrupole deformation β 2 ˜ -0.14 and abruptly changes to spherical at T˜ 1.7 MeV. The proton pairing transition occurs at critical temperature 0.6 MeV following the rule T c=0.6Δ p(0), where Δ p(0) is the proton pairing gap at zero temperature. The signatures of the above pairing transition and shape changes can be found in the specific heat curve. The single-particle level evolutions with temperature are presented. Supported by National Natural Science Foundation of China (11105042, 11305161, 11505157), Open Fund of Key Laboratory of Time and Frequency Primary Standards, CAS, and Support from Henan Administration of Foreign Experts Affairs

Optimization of beam shaping assembly based on D-T neutron generator and dose evaluation for BNCT

NASA Astrophysics Data System (ADS)

Naeem, Hamza; Chen, Chaobin; Zheng, Huaqing; Song, Jing

2017-04-01

The feasibility of developing an epithermal neutron beam for a boron neutron capture therapy (BNCT) facility based on a high intensity D-T fusion neutron generator (HINEG) and using the Monte Carlo code SuperMC (Super Monte Carlo simulation program for nuclear and radiation process) is proposed in this study. The Monte Carlo code SuperMC is used to determine and optimize the final configuration of the beam shaping assembly (BSA). The optimal BSA design in a cylindrical geometry which consists of a natural uranium sphere (14 cm) as a neutron multiplier, AlF3 and TiF3 as moderators (20 cm each), Cd (1 mm) as a thermal neutron filter, Bi (5 cm) as a gamma shield, and Pb as a reflector and collimator to guide neutrons towards the exit window. The epithermal neutron beam flux of the proposed model is 5.73 × 109 n/cm2s, and other dosimetric parameters for the BNCT reported by IAEA-TECDOC-1223 have been verified. The phantom dose analysis shows that the designed BSA is accurate, efficient and suitable for BNCT applications. Thus, the Monte Carlo code SuperMC is concluded to be capable of simulating the BSA and the dose calculation for BNCT, and high epithermal flux can be achieved using proposed BSA.

Taste information derived from T1R-expressing taste cells in mice.

PubMed

Yoshida, Ryusuke; Ninomiya, Yuzo

2016-03-01

The taste system of animals is used to detect valuable nutrients and harmful compounds in foods. In humans and mice, sweet, bitter, salty, sour and umami tastes are considered the five basic taste qualities. Sweet and umami tastes are mediated by G-protein-coupled receptors, belonging to the T1R (taste receptor type 1) family. This family consists of three members (T1R1, T1R2 and T1R3). They function as sweet or umami taste receptors by forming heterodimeric complexes, T1R1+T1R3 (umami) or T1R2+T1R3 (sweet). Receptors for each of the basic tastes are thought to be expressed exclusively in taste bud cells. Sweet (T1R2+T1R3-expressing) taste cells were thought to be segregated from umami (T1R1+T1R3-expressing) taste cells in taste buds. However, recent studies have revealed that a significant portion of taste cells in mice expressed all T1R subunits and responded to both sweet and umami compounds. This suggests that sweet and umami taste cells may not be segregated. Mice are able to discriminate between sweet and umami tastes, and both tastes contribute to behavioural preferences for sweet or umami compounds. There is growing evidence that T1R3 is also involved in behavioural avoidance of calcium tastes in mice, which implies that there may be a further population of T1R-expressing taste cells that mediate aversion to calcium taste. Therefore the simple view of detection and segregation of sweet and umami tastes by T1R-expressing taste cells, in mice, is now open to re-examination. © 2016 Authors; published by Portland Press Limited.

Identification of a novel HLA-A*02:01-restricted cytotoxic T lymphocyte epitope derived from the EML4-ALK fusion gene

PubMed Central

YOSHIMURA, MAYUKO; TADA, YOSHITAKA; OFUZI, KAZUYA; YAMAMOTO, MASAKAZU; NAKATSURA, TETSUYA

2014-01-01

Cancer immunotherapy is a promising new approach to cancer treatment. It has been demonstrated that a high number of tumor-specific cytotoxic T cells (CTLs) is associated with increased disease-specific survival in lung cancer patients. Identification of superior CTL epitopes from tumor antigens is essential for the development of immunotherapy for malignant tumors. The EML4-ALK fusion gene was recently identified in a subset of non-small cell lung cancers (NSCLCs). In this study we searched for HLA-A*02:01- and HLA-A*24:02-restricted epitopes derived from EML4-ALK by screening predicted EML4-ALK-derived candidate peptides for the induction of tumor-reactive CTLs. Nine EML4-ALK-derived peptides were selected by a computer algorithm based on a permissive HLA-A*02:01 or HLA-A*24:02 binding motif. One of the nine peptides induced peptide-specific CTLs from human peripheral blood mononuclear cells. We were able to generate a peptide-specific CTL clone. This CTL clone specifically recognized peptide-pulsed T2 cells and H2228 cells expressing HLA-A*02:01 and EML4-ALK that had been treated with IFN-γ 48 h prior to examination. CTL activity was inhibited by an anti-HLA-class I monoclonal antibody (W6/32), consistent with a class I-restricted mechanism of cytotoxicity. These results suggest that this peptide (RLSALESRV) is a novel HLA-A*02:01-restricted CTL epitope and that it may be a new target for antigen-specific immunotherapy against EML4-ALK-positive cancers. PMID:24842630

Identification of a novel HLA-A 02:01-restricted cytotoxic T lymphocyte epitope derived from the EML4-ALK fusion gene.

PubMed

Yoshimura, Mayuko; Tada, Yoshitaka; Ofuzi, Kazuya; Yamamoto, Masakazu; Nakatsura, Tetsuya

2014-07-01

Cancer immunotherapy is a promising new approach to cancer treatment. It has been demonstrated that a high number of tumor-specific cytotoxic T cells (CTLs) is associated with increased disease-specific survival in lung cancer patients. Identification of superior CTL epitopes from tumor antigens is essential for the development of immunotherapy for malignant tumors. The EML4-ALK fusion gene was recently identified in a subset of non-small cell lung cancers (NSCLCs). In this study we searched for HLA-A 02:01- and HLA-A 24:02‑restricted epitopes derived from EML4-ALK by screening predicted EML4-ALK‑derived candidate peptides for the induction of tumor‑reactive CTLs. Nine EML4-ALK‑derived peptides were selected by a computer algorithm based on a permissive HLA-A 02:01 or HLA-A 24:02 binding motif. One of the nine peptides induced peptide-specific CTLs from human peripheral blood mononuclear cells. We were able to generate a peptide‑specific CTL clone. This CTL clone specifically recognized peptide‑pulsed T2 cells and H2228 cells expressing HLA-A 02:01 and EML4-ALK that had been treated with IFN-γ 48 h prior to examination. CTL activity was inhibited by an anti-HLA‑class I monoclonal antibody (W6/32), consistent with a class I-restricted mechanism of cytotoxicity. These results suggest that this peptide (RLSALESRV) is a novel HLA-A 02:01-restricted CTL epitope and that it may be a new target for antigen-specific immunotherapy against EML4‑ALK-positive cancers.

Manifestation of two-channel nonlocal spin transport in the shapes of Hanle curves

NASA Astrophysics Data System (ADS)

Roundy, R. C.; Prestgard, M. C.; Tiwari, A.; Mishchenko, E. G.; Raikh, M. E.

2014-09-01

The dynamics of charge-density fluctuations in a system of two tunnel-coupled wires contains two diffusion modes with dispersion iω =Dq2 and iω =Dq2+2/τt, where D is the diffusion coefficient and τt is the tunneling time between the wires. The dispersion of corresponding spin-density modes depends on magnetic field as a result of the spin precession with Larmour frequency ωL. The presence of two modes affects the shape of the Hanle curve describing the spin-dependent resistance R between the ferromagnetic strips covering the nonmagnetic wires. We demonstrate that the relative shapes of the R (ωL) curves, one measured within the same wire and the other measured between the wires, depends on the ratio τt/τs, where τs is the spin-diffusion time. If the coupling between the wires is local, i.e., only at the point x =0, then the difference of the shapes of intrawire and interwire Hanle curves reflects the difference in statistics of diffusive trajectories, which "switch" or do not switch near x =0. When one of the coupled wires is bent into a loop with a radius a, the shape of the Hanle curve reflects the statistics of random walks on the loop. This statistics is governed by the dimensionless parameter a /√Dτs .

Data-driven Techniques to Estimate Parameters in the Homogenized Energy Model for Shape Memory Alloys

DTIC Science & Technology

2011-11-01

sensor. volume 79781K. Proceedings of the SPIE 7978, 2011. [9] D.J. Hartl , D.C. Lagoudas, F.T. Calkins, and J.H. Mabe . Use of a ni60ti shape memory...alloy for active jet engine chevron application: I. thermomechanical characterization. Smart Materials and Structures, 19:1–14, 2010. [10] D.J. Hartl ...D.C. Lagoudas, F.T. Calkins, and J.H. Mabe . Use of a ni60ti shape memory alloy for active jet engine chevron application: II. experimentally validated

Chain Rule Approach for Calculating the Time-Derivative of Flux

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langenbrunner, James R.; Booker, Jane M.

The reaction history (gamma-flux observable) is mathematically studied by using the chain rule for taking the total-time derivatives. That is, the total time-derivative of flux is written as the product of the ion temperature derivative with respect to time and the derivative of the flux with respect to ion temperature. Some equations are derived using the further simplification that the fusion reactivity is a parametrized function of ion temperature, T. Deuterium-tritium (D-T) fusion is used as the application with reactivity calculations from three established reactivity parametrizations.

Multidisciplinary Aerodynamic-Structural Shape Optimization Using Deformation (MASSOUD)

NASA Technical Reports Server (NTRS)

Samareh, Jamshid A.

2000-01-01

This paper presents a multidisciplinary shape parameterization approach. The approach consists of two basic concepts: (1) parameterizing the shape perturbations rather than the geometry itself and (2) performing the shape deformation by means of the soft object animation algorithms used in computer graphics. Because the formulation presented in this paper is independent of grid topology, we can treat computational fluid dynamics and finite element grids in the same manner. The proposed approach is simple, compact, and efficient. Also, the analytical sensitivity derivatives are easily computed for use in a gradient-based optimization. This algorithm is suitable for low-fidelity (e.g., linear aerodynamics and equivalent laminate plate structures) and high-fidelity (e.g., nonlinear computational fluid dynamics and detailed finite element modeling) analysis tools. This paper contains the implementation details of parameterizing for planform, twist, dihedral, thickness, camber, and free-form surface. Results are presented for a multidisciplinary application consisting of nonlinear computational fluid dynamics, detailed computational structural mechanics, and a simple performance module.

Multidisciplinary Aerodynamic-Structural Shape Optimization Using Deformation (MASSOUD)

NASA Technical Reports Server (NTRS)

Samareh, Jamshid A.

2000-01-01

This paper presents a multidisciplinary shape parameterization approach. The approach consists of two basic concepts: (1) parameterizing the shape perturbations rather than the geometry itself and (2) performing the shape deformation by means of the soft object animation algorithms used in computer graphics. Because the formulation presented in this paper is independent of grid topology, we can treat computational fluid dynamics and finite element grids in a similar manner. The proposed approach is simple, compact, and efficient. Also, the analytical sensitivity derivatives are easily computed for use in a gradient-based optimization. This algorithm is suitable for low-fidelity (e.g., linear aerodynamics and equivalent laminated plate structures) and high-fidelity (e.g., nonlinear computational fluid dynamics and detailed finite element modeling analysis tools. This paper contains the implementation details of parameterizing for planform, twist, dihedral, thickness, camber, and free-form surface. Results are presented for a multidisciplinary design optimization application consisting of nonlinear computational fluid dynamics, detailed computational structural mechanics, and a simple performance module.

Invariant natural killer T cells from children with versus without food allergy exhibit differential responsiveness to milk-derived sphingomyelin.

PubMed

Jyonouchi, Soma; Abraham, Valsamma; Orange, Jordan S; Spergel, Jonathan M; Gober, Laura; Dudek, Emily; Saltzman, Rushani; Nichols, Kim E; Cianferoni, Antonella

2011-07-01

A key immunologic feature of food allergy (FA) is the presence of a T(h)2-type cytokine bias. Ligation of the invariant natural killer T cell (iNKT) T-cell receptor (TCR) by sphingolipids presented via the CD1d molecule leads to copious secretion of T(h)2-type cytokines. Major food allergens (eg, milk, egg) are the richest dietary source of sphingolipids (food-derived sphingolipids [food-SLs]). Nonetheless, the role of iNKTs in FA is unknown. To investigate the role of iNKTs in FA and to assess whether food-SL-CD1d complexes can engage the iNKT-TCR and induce iNKT functions. PBMCs from 15 children with cow's milk allergy (MA), 12 children tolerant to cow's milk but with allergy to egg, and 13 healthy controls were incubated with α-galactosylceramide (αGal), cow's milk-sphingomyelin, or hen's egg-ceramide. iNKTs were quantified, and their cytokine production and proliferation were assessed. Human CD1d tetramers loaded with milk-sphingomyelin or egg-ceramide were used to determine food-SL binding to the iNKT-TCR. Milk-sphingomyelin, but not egg-ceramide, can engage the iNKT-TCR and induce iNKT proliferation and T(h)2-type cytokine secretion. Children with FA, especially those with MA, had significantly fewer peripheral blood iNKTs and their iNKTs exhibited a greater T(h)2 response to αGal and milk-sphingomyelin than iNKTs of healthy controls. iNKTs from children with FA, especially those with MA, are reduced in number and exhibit a T(h)2 bias in response to αGal and milk-sphingomyelin. These data suggest a potential role for iNKTs in FA. Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Melanoma exosomes deliver a complex biological payload that upregulates PTPN11 to suppress T lymphocyte function.

PubMed

Wu, Yueting; Deng, Wentao; McGinley, Emily Chambers; Klinke, David J

2017-03-01

As exosomes are emerging as a new mode of intercellular communication, we hypothesized that the payload contained within exosomes is shaped by somatic evolution. To test this, we assayed the impact on primary CD8+ T-cell function, a key mechanism for antitumor immunity, of exosomes derived from three melanoma-related cell lines. While morphologically similar, exosomes from each cell line were functionally different, as B16F0 exosomes dose-dependently suppressed T-cell proliferation. In contrast, Cloudman S91 exosomes promoted T-cell proliferation and Melan-A exosomes had a negligible effect on primary CD8+ T cells. Mechanistically, transcript profiling suggested that exosomal mRNA is enriched for full-length mRNAs that target immune-related pathways. Interestingly, B16F0 exosomes were unique in that they contained both protein and mRNA for PTPN11, which inhibited T-cell proliferation. Collectively, the results suggest that upregulation of PTPN11 by B16F0 exosomes to tumor infiltrating lymphocytes would bypass the extracellular control of the immune checkpoints. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mast cells enhance T cell activation: Importance of mast cell-derived TNF

NASA Astrophysics Data System (ADS)

Nakae, Susumu; Suto, Hajime; Kakurai, Maki; Sedgwick, Jonathon D.; Tsai, Mindy; Galli, Stephen J.

2005-05-01

Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production. allergy | asthma | autoimmunity | cytokines | immune response

Peripheral myeloid-derived suppressor and T regulatory PD-1 positive cells predict response to neoadjuvant short-course radiotherapy in rectal cancer patients

PubMed Central

Napolitano, Maria; D'Alterio, Crescenzo; Cardone, Eleonora; Trotta, Anna Maria; Pecori, Biagio; Rega, Daniela; Pace, Ugo; Scala, Dario; Scognamiglio, Giosuè; Tatangelo, Fabiana; Cacciapuoti, Carmela; Pacelli, Roberto; Delrio, Paolo; Scala, Stefania

2015-01-01

Short-course preoperative radiotherapy (SC-RT) followed by total mesorectal excision (TME) is one therapeutic option for locally advanced rectal cancer (LARC) patients. Since radio-induced DNA damage may affect tumor immunogenicity, Myeloid-derived suppressor cells (MDSCs) and T regulatory cells (Tregs) were evaluated in 13 patients undergoing SC-RT and TME for LARC. Peripheral Granulocytic-MDSCs (G-MDSC) [LIN−/HLA-DR−/CD11b+/CD14−/CD15+/CD33+], Monocytic (M-MDSC) [CD14+/HLA-DR−/lowCD11b+/CD33+] and Tregs [CD4+/CD25hi+/FOXP3+- CTLA-4/PD1] basal value was significantly higher in LARC patients compared to healthy donors (HD). Peripheral MDSC and Tregs were evaluated at time 0 (T0), after 2 and 5 weeks (T2-T5) from radiotherapy; before surgery (T8) and 6–12 months after surgery (T9, T10). G-MDSC decreased at T5 and further at T8 while M-MDSC cells decreased at T5; Tregs reached the lowest value at T5. LARC poor responder patients displayed a major decrease in M-MDSC after SC-RT and an increase of Treg-PD-1. In this pilot study MDSCs and Tregs decrease during the SC-RT treatment could represent a biomarker of response in LARC patients. Further studies are needed to confirm that the deepest M-MDSC reduction and increase in Treg-PD1 cells within 5–8 weeks from the beginning of treatment could discriminate LARC patients poor responding to SC-RT. PMID:25823653

Shape-Based Virtual Screening with Volumetric Aligned Molecular Shapes

PubMed Central

Koes, David Ryan; Camacho, Carlos J.

2014-01-01

Shape-based virtual screening is an established and effective method for identifying small molecules that are similar in shape and function to a reference ligand. We describe a new method of shape-based virtual screening, volumetric aligned molecular shapes (VAMS). VAMS uses efficient data structures to encode and search molecular shapes. We demonstrate that VAMS is an effective method for shape-based virtual screening and that it can be successfully used as a pre-filter to accelerate more computationally demanding search algorithms. Unique to VAMS is a novel minimum/maximum shape constraint query for precisely specifying the desired molecular shape. Shape constraint searches in VAMS are particularly efficient and millions of shapes can be searched in a fraction of a second. We compare the performance of VAMS with two other shape-based virtual screening algorithms a benchmark of 102 protein targets consisting of more than 32 million molecular shapes and find that VAMS provides a competitive trade-off between run-time performance and virtual screening performance. PMID:25049193

Optimization of an idealized Y-Shaped Extracardiac Fontan Baffle

NASA Astrophysics Data System (ADS)

Yang, Weiguang; Feinstein, Jeffrey; Mohan Reddy, V.; Marsden, Alison

2008-11-01

Research has showed that vascular geometries can significantly impact hemodynamic performance, particularly in pediatric cardiology, where anatomy varies from one patient to another. In this study we optimize a newly proposed design for the Fontan procedure, a surgery used to treat single ventricle heart patients. The current Fontan procedure connects the inferior vena cava (IVC) to the pulmonary arteries (PA's) via a straight Gore-Tex tube, forming a T-shaped junction. In the Y-graft design, the IVC is connected to the left and right PAs by two branches. Initial studies on the Y-graft design showed an increase in efficiency and improvement in flow distribution compared to traditional designs in a single patient-specific model. We now optimize an idealized Y-graft model to refine the design prior to patient testing. A derivate-free optimization algorithm using Kriging surrogate functions and mesh adaptive direct search is coupled to a 3-D finite element Navier-Stokes solver. We will present optimization results for rest and exercise conditions and examine the influence of energy efficiency, wall shear stress, pulsatile flow, and flow distribution on the optimal design.

Folding behavior of a T-shaped, ribosome-binding translation enhancer implicated in a wide-spread conformational switch

PubMed Central

Le, My-Tra; Kasprzak, Wojciech K; Kim, Taejin; Gao, Feng; Young, Megan YL; Yuan, Xuefeng; Shapiro, Bruce A; Seog, Joonil; Simon, Anne E

2017-01-01

Turnip crinkle virus contains a T-shaped, ribosome-binding, translation enhancer (TSS) in its 3’UTR that serves as a hub for interactions throughout the region. The viral RNA-dependent RNA polymerase (RdRp) causes the TSS/surrounding region to undergo a conformational shift postulated to inhibit translation. Using optical tweezers (OT) and steered molecular dynamic simulations (SMD), we found that the unusual stability of pseudoknotted element H4a/Ψ3 required five upstream adenylates, and H4a/Ψ3 was necessary for cooperative association of two other hairpins (H5/H4b) in Mg2+. SMD recapitulated the TSS unfolding order in the absence of Mg2+, showed dependence of the resistance to pulling on the 3D orientation and gave structural insights into the measured contour lengths of the TSS structure elements. Adenylate mutations eliminated one-site RdRp binding to the 3’UTR, suggesting that RdRp binding to the adenylates disrupts H4a/Ψ3, leading to loss of H5/H4b interaction and promoting a conformational switch interrupting translation and promoting replication. DOI: http://dx.doi.org/10.7554/eLife.22883.001 PMID:28186489

Thermodynamics of Nucleic Acid ‘Shape Readout’ by an Aminosugar†

PubMed Central

Xi, Hongjuan; Davis, Erik; Ranjan, Nihar; Xue, Liang; Hyde-Volpe, David; Arya, Dev P.

2012-01-01

Recognition of nucleic acids is important for our understanding of nucleic acid structure as well as for our understanding of nucleic acid-protein interactions. In addition to the direct readout mechanisms of nucleic acids such as H-bonding, shape recognition of nucleic acids is being increasingly recognized to play an equally important role in DNA recognition. Competition Dialysis, UV, Flourescent Intercalator displacement (FID), Computational Docking, and calorimetry studies were conducted to study the interaction of neomycin with a variety of nucleic acid conformations (shapes). At pH 5.5, these results suggest: (1) Neomycin binds three RNA structures (16S A site rRNA, poly(rA)•poly(rA), and poly(rA)•poly(rU)) with high affinities, Ka~107M−1. (2) The binding of neomycin to A-form GC-rich oligomer d(A2G15C15T2)2 has comparable affinity to RNA structures. (3) The binding of neomycin to DNA•RNA hybrids shows a three-fold variance attributable to their structural differences (poly(dA) •poly(rU), Ka=9.4×106M−1 and poly(rA)•poly(dT), Ka=3.1×106M−1). (4) The interaction of neomycin with DNA triplex poly(dA)•2poly(dT) yields a binding affinity of Ka=2.4×105M−1. (5) Poly(dA-dT)2 showed the lowest association constant for all nucleic acids studied (Ka=<105). (6) Neomycin binds to G-quadruplexes with Ka~104-105M−1. (7) Computational studies show that the decrease in major groove width in the B to A transition correlates with increasing neomycin affinity. Neomycin’s affinity for various nucleic acid structures can be ranked as follows, RNAs and GC-rich d(A2G15C15T2)2 structures > poly(dA)•poly(rU) > poly(rA)•poly(dT) > T•A-T triplex , G-quadruplexes, B-form AT-rich or GC-rich DNA sequences. The results illustrate the first example of a small molecule based ‘shape readout’ of different nucleic acid conformations. PMID:21863895

The Extraction of 3D Shape from Texture and Shading in the Human Brain

PubMed Central

Georgieva, Svetlana S.; Todd, James T.; Peeters, Ronald

2008-01-01

We used functional magnetic resonance imaging to investigate the human cortical areas involved in processing 3-dimensional (3D) shape from texture (SfT) and shading. The stimuli included monocular images of randomly shaped 3D surfaces and a wide variety of 2-dimensional (2D) controls. The results of both passive and active experiments reveal that the extraction of 3D SfT involves the bilateral caudal inferior temporal gyrus (caudal ITG), lateral occipital sulcus (LOS) and several bilateral sites along the intraparietal sulcus. These areas are largely consistent with those involved in the processing of 3D shape from motion and stereo. The experiments also demonstrate, however, that the analysis of 3D shape from shading is primarily restricted to the caudal ITG areas. Additional results from psychophysical experiments reveal that this difference in neuronal substrate cannot be explained by a difference in strength between the 2 cues. These results underscore the importance of the posterior part of the lateral occipital complex for the extraction of visual 3D shape information from all depth cues, and they suggest strongly that the importance of shading is diminished relative to other cues for the analysis of 3D shape in parietal regions. PMID:18281304

Transfer potentials shape and equilibrate monetary systems

NASA Astrophysics Data System (ADS)

Fischer, Robert; Braun, Dieter

2003-04-01

We analyze a monetary system of random money transfer on the basis of double entry bookkeeping. Without boundary conditions, we do not reach a price equilibrium and violate text-book formulas of economist's quantity theory ( MV= PQ). To match the resulting quantity of money with the model assumption of a constant price, we have to impose boundary conditions. They either restrict specific transfers globally or impose transfers locally. Both connect through a general framework of transfer potentials. We show that either restricted or imposed transfers can shape Gaussian, tent-shape exponential, Boltzmann-exponential, pareto or periodic equilibrium distributions. We derive the master equation and find its general time-dependent approximate solution. An equivalent of quantity theory for random money transfer under the boundary conditions of transfer potentials is given.

T Cell Stimulatory Effects of Korean Red Ginseng through Modulation of Myeloid-Derived Suppressor Cells.

PubMed

Jeon, Chanoh; Kang, Soowon; Park, Seungbeom; Lim, Kyungtaek; Hwang, Kwang Woo; Min, Hyeyoung

2011-11-01

Myeloid-derived suppressor cells (MDSCs) actively suppress immune cells and have been considered as an impediment to successful cancer immunotherapy. Many approaches have been made to overcome such immunosuppressive factors and to exert effective anti-tumor effects, but the possibility of using medicinal plants for this purpose has been overlooked. Korean red ginseng (KRG) is widely known to possess a variety of pharmacological properties, including immunoboosting and anti-tumor activities. However, little has been done to assess the anti-tumor activity of KRG on MDSCs. Therefore, we examined the effects of KRG on MDSCs in tumor-bearing mice and evaluated immunostimulatory and anti-tumor activities of KRG through MDSC modulation. The data show that intraperitoneal administration of KRG compromises MDSC function and induces T cell proliferation and the secretion of IL-2 and IFN-γ, while it does not exhibit direct cytotoxicity on tumor cells and reduced MDSC accumulation. MDSCs isolated from KRG-treated mice also express significantly lower levels of inducible nitric oxide synthase and IL-10 accompanied by a decrease in nitric oxide production compared with control. Taken together, the present study demonstrates that KRG enhances T cell function by inhibiting the immunosuppressive activity of MDSCs and suggests that although KRG alone does not exhibit direct anti-tumor effects, the use of KRG together with conventional chemo- or immunotherapy may provide better outcomes to cancer patients through MDSC modulation.

Resolution of ab initio shapes determined from small-angle scattering.

PubMed

Tuukkanen, Anne T; Kleywegt, Gerard J; Svergun, Dmitri I

2016-11-01

Spatial resolution is an important characteristic of structural models, and the authors of structures determined by X-ray crystallography or electron cryo-microscopy always provide the resolution upon publication and deposition. Small-angle scattering of X-rays or neutrons (SAS) has recently become a mainstream structural method providing the overall three-dimensional structures of proteins, nucleic acids and complexes in solution. However, no quantitative resolution measure is available for SAS-derived models, which significantly hampers their validation and further use. Here, a method is derived for resolution assessment for ab initio shape reconstruction from scattering data. The inherent variability of the ab initio shapes is utilized and it is demonstrated how their average Fourier shell correlation function is related to the model resolution. The method is validated against simulated data for proteins with known high-resolution structures and its efficiency is demonstrated in applications to experimental data. It is proposed that henceforth the resolution be reported in publications and depositions of ab initio SAS models.

Resolution of ab initio shapes determined from small-angle scattering

PubMed Central

Tuukkanen, Anne T.; Kleywegt, Gerard J.; Svergun, Dmitri I.

2016-01-01

Spatial resolution is an important characteristic of structural models, and the authors of structures determined by X-ray crystallography or electron cryo-microscopy always provide the resolution upon publication and deposition. Small-angle scattering of X-rays or neutrons (SAS) has recently become a mainstream structural method providing the overall three-dimensional structures of proteins, nucleic acids and complexes in solution. However, no quantitative resolution measure is available for SAS-derived models, which significantly hampers their validation and further use. Here, a method is derived for resolution assessment for ab initio shape reconstruction from scattering data. The inherent variability of the ab initio shapes is utilized and it is demonstrated how their average Fourier shell correlation function is related to the model resolution. The method is validated against simulated data for proteins with known high-resolution structures and its efficiency is demonstrated in applications to experimental data. It is proposed that henceforth the resolution be reported in publications and depositions of ab initio SAS models. PMID:27840683

A fully relativistic twisted disc around a slowly rotating Kerr black hole: derivation of dynamical equations and the shape of stationary configurations

NASA Astrophysics Data System (ADS)

Zhuravlev, V. V.; Ivanov, P. B.

2011-08-01

In this paper we derive equations describing the dynamics and stationary configurations of a twisted fully relativistic thin accretion disc around a slowly rotating black hole. We assume that the inclination angle of the disc is small and that the standard relativistic generalization of the α model of accretion discs is valid when the disc is flat. We find that similar to the case of non-relativistic twisted discs the disc dynamics and stationary shapes can be determined by a pair of equations formulated for two complex variables describing the orientation of the disc rings and velocity perturbations induced by the twist. We analyse analytically and numerically the shapes of stationary twisted configurations of accretion discs having non-zero inclinations with respect to the black hole equatorial plane at large distances r from the black hole. It is shown that the stationary configurations depend on two parameters - the viscosity parameter α and the parameter ?, where δ* is the opening angle (δ*˜h/r, where h is the disc half-thickness and r is large) of a flat disc and a is the black hole rotational parameter. When a > 0 and ? the shapes depend drastically on the value of α. When α is small the disc inclination angle oscillates with radius with amplitude and radial frequency of the oscillations dramatically increasing towards the last stable orbit, Rms. When α has a moderately small value the oscillations do not take place but the disc does not align with the equatorial plane at small radii. The disc inclination angle either is increasing towards Rms or exhibits a non-monotonic dependence on the radial coordinate. Finally, when α is sufficiently large the disc aligns with the equatorial plane at small radii. When a < 0 the disc aligns with the equatorial plane for all values of α. The results reported here may have implications for determining the structure and variability of accretion discs close to Rms as well as for modelling of emission spectra coming

Low density biodegradable shape memory polyurethane foams for embolic biomedical applications

PubMed Central

Singhal, Pooja; Small, Ward; Cosgriff-Hernandez, Elizabeth; Maitland, Duncan J; Wilson, Thomas S

2014-01-01

Low density shape memory polymer foams hold significant interest in the biomaterials community for their potential use in minimally invasive embolic biomedical applications. The unique shape memory behavior of these foams allows them to be compressed to a miniaturized form, which can be delivered to an anatomical site via a transcatheter process, and thereafter actuated to embolize the desired area. Previous work in this field has described the use of a highly covalently crosslinked polymer structure for maintaining excellent mechanical and shape memory properties at the application-specific ultra low densities. This work is aimed at further expanding the utility of these biomaterials, as implantable low density shape memory polymer foams, by introducing controlled biodegradability. A highly covalently crosslinked network structure was maintained by use of low molecular weight, symmetrical and polyfunctional hydroxyl monomers such as Polycaprolactone triol (PCL-t, Mn 900 g), N,N,N0,N0-Tetrakis (hydroxypropyl) ethylenediamine (HPED), and Tris (2-hydroxyethyl) amine (TEA). Control over the degradation rate of the materials was achieved by changing the concentration of the degradable PCL-t monomer, and by varying the material hydrophobicity. These porous SMP materials exhibit a uniform cell morphology and excellent shape recovery, along with controllable actuation temperature and degradation rate. We believe that they form a new class of low density biodegradable SMP scaffolds that can potentially be used as “smart” non-permanent implants in multiple minimally invasive biomedical applications. PMID:24090987

Convergent evolution of sexual shape dimorphism in Diptera.

PubMed

Bonduriansky, Russell

2006-05-01

Several patterns of sexual shape dimorphism, such as male body elongation, eye stalks, or extensions of the exoskeleton, have evolved repeatedly in the true flies (Diptera). Although these dimorphisms may have evolved in response to sexual selection on male body shape, conserved genetic factors may have contributed to this convergent evolution, resulting in stronger phenotypic convergence than might be expected from functional requirements alone. I compared phenotypic variation in body shape in two distantly related species exhibiting sexually dimorphic body elongation: Prochyliza xanthostoma (Piophilidae) and Telostylinus angusticollis (Neriidae). Although sexual selection appears to act differently on male body shape in these species, they exhibited strikingly similar patterns of sexual dimorphism. Likewise, patterns of within-sex shape variation were similar in the two species, particularly in males: relative elongation of the male head capsule, antenna, and legs was associated with reduced head capsule width and wing length, but was nearly independent of variation in thorax length. However, the two species presented contrasting patterns of static allometry: male sexual traits exhibited elevated allometric slopes in T. angusticollis, but not in P. xanthostoma. These results suggest that a shared pattern of covariation among traits may have channeled the evolution of sexually dimorphic body elongation in these species. Nonetheless, static allometries may have been shaped by species-specific selection pressures or genetic architectures. Copyright 2006 Wiley-Liss, Inc.

ROTATIONAL- SHOCK(S) Impulse-Jerk(I-J) [VS. T=I α] Plasticity/Fracture Burst Acoustic-Emission(BAE) NON: ``1''/[f= ω]-``Noise'' Power-Law Power-Spectrum is T=I α DERIVATIVE I-J Time-Series Integral-Transform

NASA Astrophysics Data System (ADS)

Lewis, Thomas; Siegel, Edward

2011-06-01

ROTATIONAL-[``spin-up''/``spin-down'']-SHOCK(S)-plasticity/fracture BAE[E.S.:MSE 8,310(71); PSS:(a)5,601 /607(71); Xl..-Latt. Defects 5,277(74);Scripta Met.:6,785(72);8,587/617(74);3rd Tokyo A.-E. Symp.(76);Acta Met. 25,383(77);JMMM 7,312(78)] NON: ``1''/ ω noise'' Zipf-(Pareto); power-law universality power-spectrum; is manifestly-demonstrated in two distinct ways to be nothing but ROTATIONAL(in 2 OR 3-dimensions)ANGULAR-momentum Newton's 3rd Law of Motion T=I α=dJ/dt REdiscovery!!! A/Siegel PHYSICS derivation FAILS!!! ''PURE''-MATHS: dT(t)/dt=(dJ(t)/dt)2=[I(t)d α(t)/dt+ α(t)(t)dI(t)/dt TRIPLE-integral VS. T=I α DOUBLE-integral time-series(T-S) Dichotomy: θ(t)=[ϖ0 t + α(t) t 2 / 2 + EXTRA-TERM(S)] VS. θ(t)=[ϖ0 t + α(t) t 2 / 2 ] integral-transform formally defines power-spectrum Dichotomy: P(ω) =? θ(t)e-iωtdt=?[ϖ0 t + αt2 / 2 ]e-iωtdt=φ0?te-iωtdt+?{[ α ≠ α (t)]/2}t2eiωtdt= φ0 (ω) /d ω+{[a ≠a(t)]/2}d2 δ (ω) /dω2 =φ0 /ω0+{[ α ≠ α (t)]/2}/ω 1 . 000 ...: if α=0, then P(ω) 1/ω0, VS. if α ≠ α (t) ≠0, then P(ω) 1/ ω 1/ω 1 . 000 ...

Molecular mimicry between protein and tRNA.

PubMed

Nakamura, Y

2001-01-01

Mimicry is a sophisticated development in animals, fish, and plants that allows them to fool others by imitating a shape or color for diverse purposes, such as to prey, evade, lure, pollinate, or threaten. This is not restricted to the macro-world, but extends to the micro-world as molecular mimicry. Recent advances in structural and molecular biology uncovered a set of translation factors that resembles a tRNA shape and, in one case, even mimics a tRNA function for deciphering the genetic code. Nature must have evolved this art of molecular mimicry between protein and ribonucleic acid by using different protein structures until the translation factors sat in the cockpit of a ribosome machine, on behalf of tRNA, and achieved diverse actions. Structural, functional, and evolutionary aspects of molecular mimicry will be discussed.

Burn-injury affects gut-associated lymphoid tissues derived CD4+ T cells.

PubMed

Fazal, Nadeem; Shelip, Alla; Alzahrani, Alhusain J

2013-01-01

After scald burn-injury, the intestinal immune system responds to maintain immune balance. In this regard CD4+T cells in Gut-Associated Lymphoid Tissues (GALT), like mesenteric lymph nodes (MLN) and Peyer's patches (PP) respond to avoid immune suppression following major injury such as burn. Therefore, we hypothesized that the gut CD4+T cells become dysfunctional and turn the immune homeostasis towards depression of CD4+ T cell-mediated adaptive immune responses. In the current study we show down regulation of mucosal CD4+ T cell proliferation, IL-2 production and cell surface marker expression of mucosal CD4+ T cells moving towards suppressive-type. Acute burn-injury lead to up-regulation of regulatory marker (CD25+), down regulation of adhesion (CD62L, CD11a) and homing receptor (CD49d) expression, and up-regulation of negative co-stimulatory (CTLA-4) molecule. Moreover, CD4+CD25+ T cells of intestinal origin showed resistance to spontaneous as well as induced apoptosis that may contribute to suppression of effector CD4+ T cells. Furthermore, gut CD4+CD25+ T cells obtained from burn-injured animals were able to down-regulate naïve CD4+ T cell proliferation following adoptive transfer of burn-injured CD4+CD25+ T cells into sham control animals, without any significant effect on cell surface activation markers. Together, these data demonstrate that the intestinal CD4+ T cells evolve a strategy to promote suppressive CD4+ T cell effector responses, as evidenced by enhanced CD4+CD25+ T cells, up-regulated CTLA-4 expression, reduced IL-2 production, tendency towards diminished apoptosis of suppressive CD4+ T cells, and thus lose their natural ability to regulate immune homeostasis following acute burn-injury and prevent immune paralysis.

Biodegradable shape-memory block co-polymers for fast self-expandable stents.

PubMed

Xue, Liang; Dai, Shiyao; Li, Zhi

2010-11-01

Block co-polymers PCTBVs (M(n) of 36,300-65,300 g/mol, T(m) of 39-40 and 142 degrees C) containing hyperbranched three-arm poly(epsilon-caprolactone) (PCL) as switching segment and microbial polyester PHBV as crystallizable hard segment were designed as biodegradable shape-memory polymer (SMP) for fast self-expandable stent and synthesized in 96% yield by the reaction of three-arm PCL-triol (M(n) of 4200 g/mol, T(m) of 47 degrees C) with methylene diphenyl 4,4'-diisocyanate isocynate (MDI) to form the hyperbrached MDI-linked PCL (PTCM; M(n) of 25,400 g/mol and a T(m) of 38 degrees C), followed by further polymerization with PHBV-diol (M(n) of 2200 g/mol, T(m) of 137 and 148 degrees C). The polymers were characterized by (1)H NMR, GPC, DSC, tensile test, and cyclic thermomechanical tensile test. PCTBVs showed desired thermal properties, mechanical properties, and ductile nature. PCTBV containing 25 wt% PHBV (PCTBV-25) demonstrated excellent shape-memory property at 40 degrees C, with R(f) of 94%, R(r) of 98%, and shape recovery within 25s. PCTBV-25 was also shown as a safe material with good biocompatibility by cytotoxicity tests and cell growth experiments. The stent made from PCTBV-25 film showed nearly complete self-expansion at 37 degrees C within only 25 s, which is much better and faster than the best known self-expandable stents. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Vaccination with EphA2-derived T cell-epitopes promotes immunity against both EphA2-expressing and EphA2-negative tumors

PubMed Central

Hatano, Manabu; Kuwashima, Naruo; Tatsumi, Tomohide; Dusak, Jill E; Nishimura, Fumihiko; Reilly, Karlyne M; Storkus, Walter J; Okada, Hideho

2004-01-01

Background A novel tyrosine kinase receptor EphA2 is expressed at high levels in advanced and metastatic cancers. We examined whether vaccinations with synthetic mouse EphA2 (mEphA2)-derived peptides that serve as T cell epitopes could induce protective and therapeutic anti-tumor immunity. Methods C57BL/6 mice received subcutaneous (s.c.) vaccinations with bone marrow-derived dendritic cells (DCs) pulsed with synthetic peptides recognized by CD8+ (mEphA2671–679, mEphA2682–689) and CD4+ (mEphA230–44) T cells. Splenocytes (SPCs) were harvested from primed mice to assess the induction of cytotoxic T lymphocyte (CTL) responses against syngeneic glioma, sarcoma and melanoma cell lines. The ability of these vaccines to prevent or treat tumor (s.c. injected MCA205 sarcoma or B16 melanoma; i.v. injected B16-BL6) establishment/progression was then assessed. Results Immunization of C57BL/6 mice with mEphA2-derived peptides induced specific CTL responses in SPCs. Vaccination with mEPhA2 peptides, but not control ovalbumin (OVA) peptides, prevented the establishment or prevented the growth of EphA2+ or EphA2-negative syngeneic tumors in both s.c. and lung metastasis models. Conclusions These data indicate that mEphA2 can serve as an attractive target against which to direct anti-tumor immunity. The ability of mEphA2 vaccines to impact EphA2-negative tumors such as the B16 melanoma may suggest that such beneficial immunity may be directed against alternative EphA2+ target cells, such as the tumor-associated vascular endothelial cells. PMID:15563374

An observational study investigating the association of ultrasonographically assessed machine milking-induced changes in teat condition and teat-end shape in dairy cows.

PubMed

Wieland, M; Virkler, P D; Borkowski, A H; Älveby, N; Wood, P; Nydam, D V

2018-06-21

Mechanical forces during machine milking induce changes in teat condition which can be differentiated into short-term and long-term changes. Machine milking-induced short-term changes in teat condition (STC) are defined as tissue responses to a single milking and have been associated with the risk of new intramammary infection. Albeit, their association with teat characteristics, such as teat-end shape, has not been investigated by rigorous methods. The primary objective was to determine the association of STC, as measured by ultrasonography, with teat-end shape. The second objective was to describe possible differences in the recovery time of teat tissue after machine milking among teats with different teat-end shapes. Holstein cows (n=128) were enrolled in an observational study, housed in free-stall pens with sand bedding and milked three times a day. Ultrasonography of the left front and right hind teat was performed after teat preparation before milking (t-1), immediately after milking (t 0) and 1, 3, 5 and 7 h after milking (t 1, t 3, t 5, t 7). The teat tissue parameters measured from ultrasound scans were teat canal length, teat-end diameter, teat-end diameter at the midpoint between the distal and proximal end of the teat canal, teat wall thickness, and teat cistern width. Teat-end shape was assessed visually and classified into three categories: pointed, flat and round. Multivariable linear regression analyses showed differences in the relative change of teat tissue parameters (compared with t-1) at t 0 among teats with different teat-end shapes, with most parameters showing the largest change for round teats. The premilking values were reached (recovery time) after 7 h in teats with a pointed teat-end shape, whereas recovery time was greater than 7 h in teats with flat and round teat-end shapes. Under the same liner and milking machine conditions, teats with a round teat-end shape had the most severe short-term changes. The results of this observational

A static model of a Sendzimir mill for use in shape control

NASA Astrophysics Data System (ADS)

Gunawardene, G. W. D. M.

The design of shape control systems is an area of current interest in the steel industry. Shape is defined as the internal stress distribution resulting from a transverse variation in the reduction of the strip thickness. The object of shape control is to adjust the mill so that the rolled strip is free from internal stresses. Both static and dynamic models of the mill are required for the control system design.The subject of this thesis is the static model of the Sendzimir cold rolling mill, which is a 1-2-3-4 type cluster mill. The static model derived enables shape profiles to be calculated for a given set of actuator positions, and is used to generate the steady state mill gains. The method of calculation of these shape profiles is discussed. The shape profiles obtained for different mill schedules are plotted against the distance across the strip. The corresponding mill gains are calculated and these relate the shape changes to the actuator changes. These mill gains are presented in the form of a square matrix, obtained by measuring shape at eight points across the strip.

Statistical 3D shape analysis of gender differences in lateral ventricles

NASA Astrophysics Data System (ADS)

He, Qing; Karpman, Dmitriy; Duan, Ye

2010-03-01

This paper aims at analyzing gender differences in the 3D shapes of lateral ventricles, which will provide reference for the analysis of brain abnormalities related to neurological disorders. Previous studies mostly focused on volume analysis, and the main challenge in shape analysis is the required step of establishing shape correspondence among individual shapes. We developed a simple and efficient method based on anatomical landmarks. 14 females and 10 males with matching ages participated in this study. 3D ventricle models were segmented from MR images by a semiautomatic method. Six anatomically meaningful landmarks were identified by detecting the maximum curvature point in a small neighborhood of a manually clicked point on the 3D model. Thin-plate spline was used to transform a randomly selected template shape to each of the rest shape instances, and the point correspondence was established according to Euclidean distance and surface normal. All shapes were spatially aligned by Generalized Procrustes Analysis. Hotelling T2 twosample metric was used to compare the ventricle shapes between males and females, and False Discovery Rate estimation was used to correct for the multiple comparison. The results revealed significant differences in the anterior horn of the right ventricle.

The Metagenome-Derived Enzymes LipS and LipT Increase the Diversity of Known Lipases

PubMed Central

Chow, Jennifer; Kovacic, Filip; Dall Antonia, Yuliya; Krauss, Ulrich; Fersini, Francesco; Schmeisser, Christel; Lauinger, Benjamin; Bongen, Patrick; Pietruszka, Joerg; Schmidt, Marlen; Menyes, Ina; Bornscheuer, Uwe T.; Eckstein, Marrit; Thum, Oliver; Liese, Andreas; Mueller-Dieckmann, Jochen; Jaeger, Karl-Erich; Streit, Wolfgang R.

2012-01-01

Triacylglycerol lipases (EC 3.1.1.3) catalyze both hydrolysis and synthesis reactions with a broad spectrum of substrates rendering them especially suitable for many biotechnological applications. Most lipases used today originate from mesophilic organisms and are susceptible to thermal denaturation whereas only few possess high thermotolerance. Here, we report on the identification and characterization of two novel thermostable bacterial lipases identified by functional metagenomic screenings. Metagenomic libraries were constructed from enrichment cultures maintained at 65 to 75°C and screened resulting in the identification of initially 10 clones with lipolytic activities. Subsequently, two ORFs were identified encoding lipases, LipS and LipT. Comparative sequence analyses suggested that both enzymes are members of novel lipase families. LipS is a 30.2 kDa protein and revealed a half-life of 48 h at 70°C. The lipT gene encoded for a multimeric enzyme with a half-life of 3 h at 70°C. LipS had an optimum temperature at 70°C and LipT at 75°C. Both enzymes catalyzed hydrolysis of long-chain (C12 and C14) fatty acid esters and additionally hydrolyzed a number of industry-relevant substrates. LipS was highly specific for (R)-ibuprofen-phenyl ester with an enantiomeric excess (ee) of 99%. Furthermore, LipS was able to synthesize 1-propyl laurate and 1-tetradecyl myristate at 70°C with rates similar to those of the lipase CalB from Candida antarctica. LipS represents the first example of a thermostable metagenome-derived lipase with significant synthesis activities. Its X-ray structure was solved with a resolution of 1.99 Å revealing an unusually compact lid structure. PMID:23112831

Characterization of the Materials Synthesized by High Pressure-High Temperature Treatment of a Polymer Derived t-BC₂N Ceramic.

PubMed

Matizamhuka, Wallace R; Sigalas, Iakovos; Herrmann, Mathias; Dubronvinsky, Leonid; Dubrovinskaia, Natalia; Miyajima, Nobuyoshi; Mera, Gabriela; Riedel, Ralf

2011-11-29

Bulk B-C-N materials were synthesized under static high thermobaric conditions (20 GPa and 2,000 °C) in a multianvil apparatus from a polymer derived t-BC 1.97 N ceramic. The bulk samples were characterised using X-ray synchrotron radiation and analytical transmission electron microscopy in combination with electron energy loss spectroscopy. Polycrystalline B-C-N materials with a cubic type structure were formed under the applied reaction conditions, but the formation of a ternary cubic diamond-like c-BC₂N compound, could not be unambiguously confirmed.

Silicone Membranes to Inhibit Water Uptake into Thermoset Polyurethane Shape-Memory Polymer Conductive Composites.

PubMed

Yu, Ya-Jen; Infanger, Stephen; Grunlan, Melissa A; Maitland, Duncan J

2015-01-05

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature ( T g ) resulting in shape recovery in vivo . While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo . In this study, a silicone membrane was used to inhibit water uptake into a thermoset SMP composite containing conductive filler. Thermoset polyurethane (PU) SMPs were loaded with either 5 wt% carbon black (CB) or 5 wt% carbon nanotubes (CNT) and subsequently coated with either an Al 2 O 3 - or silica-filled silicone membrane. It was observed that the silicone membranes, particularly the silica-filled membrane, reduced the rate of water absorption (37 °C) and subsequent T g depression versus uncoated composites. In turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37 °C.

Silicone membranes to inhibit water uptake into thermoset polyurethane shape-memory polymer conductive composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Ya-Jen; Infanger, Stephen; Grunlan, Melissa A.

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (T g) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this paper, a silicone membrane was used to inhibit water uptake into a thermoset SMPmore » composite containing conductive filler. Thermoset polyurethane SMPs were loaded with either 5 wt % carbon black or 5 wt % carbon nanotubes, and subsequently coated with either an Al 2O 3- or silica-filled silicone membrane. It was observed that the silicone membranes, particularly the silica-filled membrane, reduced the rate of water absorption (37°C) and subsequent T g depression versus uncoated composites. Finally, in turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37°C.« less

Silicone membranes to inhibit water uptake into thermoset polyurethane shape-memory polymer conductive composites

DOE PAGES

Yu, Ya-Jen; Infanger, Stephen; Grunlan, Melissa A.; ...

2014-07-24

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (T g) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this paper, a silicone membrane was used to inhibit water uptake into a thermoset SMPmore » composite containing conductive filler. Thermoset polyurethane SMPs were loaded with either 5 wt % carbon black or 5 wt % carbon nanotubes, and subsequently coated with either an Al 2O 3- or silica-filled silicone membrane. It was observed that the silicone membranes, particularly the silica-filled membrane, reduced the rate of water absorption (37°C) and subsequent T g depression versus uncoated composites. Finally, in turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37°C.« less

DOCK8 regulates lymphocyte shape integrity for skin antiviral immunity

PubMed Central

Zhang, Qian; Dove, Christopher G.; Hor, Jyh Liang; Murdock, Heardley M.; Strauss-Albee, Dara M.; Garcia, Jordan A.; Mandl, Judith N.; Grodick, Rachael A.; Jing, Huie; Chandler-Brown, Devon B.; Lenardo, Timothy E.; Crawford, Greg; Matthews, Helen F.; Freeman, Alexandra F.; Cornall, Richard J.; Germain, Ronald N.

2014-01-01

DOCK8 mutations result in an inherited combined immunodeficiency characterized by increased susceptibility to skin and other infections. We show that when DOCK8-deficient T and NK cells migrate through confined spaces, they develop cell shape and nuclear deformation abnormalities that do not impair chemotaxis but contribute to a distinct form of catastrophic cell death we term cytothripsis. Such defects arise during lymphocyte migration in collagen-dense tissues when DOCK8, through CDC42 and p21-activated kinase (PAK), is unavailable to coordinate cytoskeletal structures. Cytothripsis of DOCK8-deficient cells prevents the generation of long-lived skin-resident memory CD8 T cells, which in turn impairs control of herpesvirus skin infections. Our results establish that DOCK8-regulated shape integrity of lymphocytes prevents cytothripsis and promotes antiviral immunity in the skin. PMID:25422492

Validity of T2 mapping in characterization of the regeneration tissue by bone marrow derived cell transplantation in osteochondral lesions of the ankle.

PubMed

Battaglia, M; Rimondi, E; Monti, C; Guaraldi, F; Sant'Andrea, A; Buda, R; Cavallo, M; Giannini, S; Vannini, F

2011-11-01

Bone marrow derived cell transplantation (BMDCT) has been recently suggested as a possible surgical technique to repair osteochondral lesions. To date, no qualitative MRI studies have evaluated its efficacy. The aim of our study is to investigate the validity of MRI T2-mapping sequence in characterizing the reparative tissue obtained and its ability to correlate with clinical results. 20 patients with an osteochondral lesion of the talus underwent BMDCT and were evaluated at 2 years follow up using MRI T2-mapping sequence. 20 healthy volunteers were recruited as controls. MRI images were acquired using a protocol suggested by the International Cartilage Repair Society, MOCART scoring system and T2 mapping. Results were then correlated with AOFAS clinical score. AOFAS score increased from 66.8±14.5 pre-operatively to 91.2±8.3 (p<0.0005) at 2 years follow-up. T2-relaxation time value of 35-45 ms was derived from healthy ankles evaluation and assumed as normal hyaline cartilage value and used as a control. Regenerated tissue with a T2-relaxation time value comparable to hyaline cartilage was found in all the cases treated, covering a mean of 78% of the repaired lesion area. A high clinical score was related directly to isointense signal in DPFSE fat sat (p=0.05), and percentage of regenerated hyaline cartilage (p=0.05), inversely to the percentage of regenerated fibrocartilage. Lesion's depth negatively related to the integrity of the repaired tissue's surface (tau=-0.523, p=0.007), and to the percentage of regenerated hyaline cartilage (rho=-0.546, p=0.013). Because of its ability to detect cartilage's quality and to correlate to the clinical score, MRI T2-mapping sequence integrated with Mocart score represent a valid, non-invasive technique for qualitative cartilage assessment after regenerative surgical procedures. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Development of an engineering model for ferromagnetic shape memory alloys

NASA Astrophysics Data System (ADS)

Tani, Yoshiaki; Todaka, Takashi; Enokizono, Masato

This paper presents a relationship among stress, temperature and magnetic properties of a ferromagnetic shape memory alloy. In order to derive an engineering model of ferromagnetic shape memory alloys, we have developed a measuring system of the relationship among stress, temperature and magnetic properties. The samples used in this measurement are Fe68-Ni10-Cr9-Mn7-Si6 wt% ferromagnetic shape memory alloy. They are thin ribbons made by rapid cooling in air. In the measurement, the ribbon sample is inserted into a sample holder winding consisting of the B-coil and compensation coils, and magnetized in an open solenoid coil. The ribbon is stressed with attachment weights and heated with a heating wire. The specific susceptibility was increased by applying tension, and slightly increased by heating below the Curie temperature.

Study of the Auger line shape of polyethylene and diamond

NASA Technical Reports Server (NTRS)

Dayan, M.; Pepper, S. V.

1984-01-01

The KVV Auger electron line shapes of carbon in polyethylene and diamond have been studied. The spectra were obtained in derivative form by electron beam excitation. They were treated by background subtraction, integration and deconvolution to produce the intrinsic Auger line shape. Electron energy loss spectra provided the response function in the deconvolution procedure. The line shape from polyethylene is compared with spectra from linear alkanes and with a previous spectrum of Kelber et al. Both spectra are compared with the self-convolution of their full valence band densities of states and of their p-projected densities. The experimental spectra could not be understood in terms of existing theories. This is so even when correlation effects are qualitatively taken into account account to the theories of Cini and Sawatzky and Lenselink.

Asteroid shape and spin statistics from convex models

NASA Astrophysics Data System (ADS)

Torppa, J.; Hentunen, V.-P.; Pääkkönen, P.; Kehusmaa, P.; Muinonen, K.

2008-11-01

We introduce techniques for characterizing convex shape models of asteroids with a small number of parameters, and apply these techniques to a set of 87 models from convex inversion. We present three different approaches for determining the overall dimensions of an asteroid. With the first technique, we measured the dimensions of the shapes in the direction of the rotation axis and in the equatorial plane and with the two other techniques, we derived the best-fit ellipsoid. We also computed the inertia matrix of the model shape to test how well it represents the target asteroid, i.e., to find indications of possible non-convex features or albedo variegation, which the convex shape model cannot reproduce. We used shape models for 87 asteroids to perform statistical analyses and to study dependencies between shape and rotation period, size, and taxonomic type. We detected correlations, but more data are required, especially on small and large objects, as well as slow and fast rotators, to reach a more thorough understanding about the dependencies. Results show, e.g., that convex models of asteroids are not that far from ellipsoids in root-mean-square sense, even though clearly irregular features are present. We also present new spin and shape solutions for Asteroids (31) Euphrosyne, (54) Alexandra, (79) Eurynome, (93) Minerva, (130) Elektra, (376) Geometria, (471) Papagena, and (776) Berbericia. We used a so-called semi-statistical approach to obtain a set of possible spin state solutions. The number of solutions depends on the abundancy of the data, which for Eurynome, Elektra, and Geometria was extensive enough for determining an unambiguous spin and shape solution. Data of Euphrosyne, on the other hand, provided a wide distribution of possible spin solutions, whereas the rest of the targets have two or three possible solutions.