Conducting processes in simulated chronic inflammatory demyelinating polyneuropathy at 20°C-42°C.

PubMed

Stephanova, D I; Daskalova, M; Mladenov, M

2015-03-01

Decreased conducting processes leading usually to conduction block and increased weakness of limbs during cold (cold paresis) or warmth (heat paresis) have been reported in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). To explore the mechanisms of these symptoms, the effects of temperature (from 20°C to 42°C) on nodal action potentials and their current kinetics in previously simulated case of 70% CIDP are investigated, using our temperature dependent multi-layered model of the myelinated human motor nerve fiber. The results show that potential amplitudes have a bifid form at 20°C. As in the normal case, for the CIDP case, the nodal action potentials are determined mainly by the nodal sodium currents (I Na ) for the temperature range of 20-39°C, as the contribution of nodal fast and slow potassium currents (I Kf and I Ks ) to the total ionic current (Ii) is negligible. Also, the contribution of I Kf and I Ks to the membrane repolarization is enhanced at temperatures higher than 39°C. However, in the temperature range of 20-42°C, all potential parameters in the CIDP case, except for the conduction block during hyperthermia (≥ 40°C) which is again at 45°C, worsen: (i) conduction velocities and potential amplitudes are decreased; (ii) afterpotentials and threshold stimulus currents for the potential generation are increased; (iii) the current kinetics of action potentials is slowed and (iv) the conduction block during hypothermia (≤ 25°C) is at temperatures lower than 20°C. These potential parameters are more altered during hyperthermia and are most altered during hypothermia. The present results suggest that the conducting processes in patients with CIDP are in higher risk during hypothermia than hyperthermia.

Prognostic impact of the level of nodal involvement: retrospective analysis of patients with advanced oral squamous cell carcinoma.

PubMed

Murakami, R; Nakayama, H; Semba, A; Hiraki, A; Nagata, M; Kawahara, K; Shiraishi, S; Hirai, T; Uozumi, H; Yamashita, Y

2017-01-01

We retrospectively evaluated the prognostic impact of the level of nodal involvement in patients with advanced oral squamous cell carcinoma (SCC). Between 2005 and 2010, 105 patients with clinical stage III or IV oral SCC had chemoradiotherapy preoperatively. Clinical (cN) and pathological nodal (pN) involvement was primarily at levels Ib and II. We defined nodal involvement at levels Ia and III-V as anterior and inferior extensions, respectively, and recorded such findings as extensive. With respect to pretreatment variables (age, clinical stage, clinical findings of the primary tumour, and nodal findings), univariate analysis showed that extensive cN was the only significant factor for overall survival (hazard ratio [HR], 3.27; 95% CI 1.50 to 7.13; p=0.001). Univariate analysis showed that all pN findings, including the nodal classification (invaded nodes, multiple, and contralateral) and extensive involvement were significant, and multivariate analysis confirmed that extensive pN (HR 4.71; 95% CI 1.85 to 11.97; p=0.001) and multiple pN (HR 2.59; 95% CI 1.10 to 6.09; p=0.029) were independent predictors of overall survival. Assessment based on the level of invaded neck nodes may be a better predictor of survival than the current nodal classification. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Flat band in disorder-driven non-Hermitian Weyl semimetals

NASA Astrophysics Data System (ADS)

Zyuzin, A. A.; Zyuzin, A. Yu.

2018-01-01

We study the interplay of disorder and band-structure topology in a Weyl semimetal with a tilted conical spectrum around the Weyl points. The spectrum of particles is given by the eigenvalues of a non-Hermitian matrix, which contains contributions from a Weyl Hamiltonian and complex self-energy due to electron elastic scattering on disorder. We find that the tilt-induced matrix structure of the self-energy gives rise to either a flat band or a nodal line segment at the interface of the electron and hole pockets in the bulk band structure of type-II Weyl semimetals depending on the Weyl cone inclination. For the tilt in a single direction in momentum space, each Weyl point expands into a flat band lying on the plane, which is transverse to the direction of the tilt. The spectrum of the flat band is fully imaginary and is separated from the in-plane dispersive part of the spectrum by the "exceptional nodal ring" where the matrix of the Green's function in momentum-frequency space is defective. The tilt in two directions might shrink a flat band into a nodal line segment with "exceptional edge points." We discuss the connection to the non-Hermitian topological theory.

Integration of root phenes revealed by intensive phenotyping of root system architecture, anatomy, and physiology in cereals

NASA Astrophysics Data System (ADS)

York, Larry

2015-04-01

Food insecurity is among the greatest challenges humanity will face in the 21st century. Agricultural production in much of the world is constrained by the natural infertility of soil which restrains crops from reaching their yield potential. In developed nations, fertilizer inputs pollute air and water and contribute to climate change and environmental degradation. In poor nations low soil fertility is a primary constraint to food security and economic development. Water is almost always limiting crop growth in any system. Increasing the acquisition efficiency of soil resources is one method by which crop yields could be increased without the use of more fertilizers or irrigation. Cereals are the most widely grown crops, both in terms of land area and in yield, so optimizing uptake efficiency of cereals is an important goal. Roots are the primary interface between plant and soil and are responsible for the uptake of soil resources. The deployment of roots in space and time comprises root system architecture (RSA). Cereal RSA is a complex phenotype that aggregates many elemental phenes (elemental units of phenotype). Integration of root phenes will be determined by interactions through their effects on soil foraging and plant metabolism. Many architectural, metabolic, and physiological root phenes have been identified in maize, including: nodal root number, nodal root growth angle, lateral root density, lateral root length, aerenchyma, cortical cell size and number, and nitrate uptake kinetics. The utility of these phenes needs confirmation in maize and in other cereals. The maize root system is composed of an embryonic root system and nodal roots that emerge in successive whorls as the plant develops, and is similar to other cereals. Current phenotyping platforms often ignore the inner whorls and instead focus on the most visible outer whorls after excavating a maize root crown from soil. Here, an intensive phenotyping platform evaluating phenes of all nodal root whorls in maize is introduced, and field work demonstrated how the variation within the root crown has functional significance for nitrogen acquisition. Nodal root number was decomposed to more elemental phenes including the number of nodes and the occupancies of each node. Simulations demonstrated that root systems forming fewer nodal roots and with delayed emergence perform well in low nitrogen soils. Nitrate uptake kinetics (NUK) also varied within the maize root system, and simulations showing a lack of interaction between NUK and RSA reflects a knowledge gap in the costs of NUK at the molecular level. Finally, maize RSA among hybrids from different era periods over the past 100 years suggests evolution towards more nitrogen efficient root phene states. This work will be discussed within the context of next-generation root phenotyping of cereals, the dilemma between extensive and intensive phenotyping, and the need for linking across scales and methods.

Recognizing nodal marginal zone lymphoma: recent advances and pitfalls. A systematic review

PubMed Central

van den Brand, Michiel; van Krieken, J. Han J.M.

2013-01-01

The diagnosis of nodal marginal zone lymphoma is one of the remaining problem areas in hematopathology. Because no established positive markers exist for this lymphoma, it is frequently a diagnosis of exclusion, making distinction from other low-grade B-cell lymphomas difficult or even impossible. This systematic review summarizes and discusses the current knowledge on nodal marginal zone lymphoma, including clinical features, epidemiology and etiology, histology, and cytogenetic and molecular features. In particular, recent advances in diagnostics and pathogenesis are discussed. New immunohistochemical markers have become available that could be used as positive markers for nodal marginal zone lymphoma. These markers could be used to ensure more homogeneous study groups in future research. Also, recent gene expression studies and studies describing specific gene mutations have provided clues to the pathogenesis of nodal marginal zone lymphoma, suggesting deregulation of the nuclear factor kappa B pathway. Nevertheless, nodal marginal zone lymphoma remains an enigmatic entity, requiring further study to define its pathogenesis to allow an accurate diagnosis and tailored treatment. However, recent data indicate that it is not related to splenic or extranodal lymphoma, and that it is also not related to lymphoplasmacytic lymphoma. Thus, even though the diagnosis is not always easy, it is clearly a separate entity. PMID:23813646

Study of flow over object problems by a nodal discontinuous Galerkin-lattice Boltzmann method

NASA Astrophysics Data System (ADS)

Wu, Jie; Shen, Meng; Liu, Chen

2018-04-01

The flow over object problems are studied by a nodal discontinuous Galerkin-lattice Boltzmann method (NDG-LBM) in this work. Different from the standard lattice Boltzmann method, the current method applies the nodal discontinuous Galerkin method into the streaming process in LBM to solve the resultant pure convection equation, in which the spatial discretization is completed on unstructured grids and the low-storage explicit Runge-Kutta scheme is used for time marching. The present method then overcomes the disadvantage of standard LBM for depending on the uniform meshes. Moreover, the collision process in the LBM is completed by using the multiple-relaxation-time scheme. After the validation of the NDG-LBM by simulating the lid-driven cavity flow, the simulations of flows over a fixed circular cylinder, a stationary airfoil and rotating-stationary cylinders are performed. Good agreement of present results with previous results is achieved, which indicates that the current NDG-LBM is accurate and effective for flow over object problems.

Cervical nodal metastases in squamous cell carcinoma of the head and neck: what to expect.

PubMed

Mukherji, S K; Armao, D; Joshi, V M

2001-11-01

The treatment and management of malignancies of the head and neck is directly altered by the presence of metastatic cervical adenopathy. The treatment of nodal metastases in squamous cell carcinoma of the head and neck (HNSCCA) is determined by the lymphatic drainage of the upper aerodigestive tract. The lymphatic drainage is site-specific and occurs in a predictable manner. The purpose of this text is to provide an overview of the normal routes of lymphatic drainage in the head and neck and correlate this with the current nodal classification system. The specific aims of this manuscript are to 1) illustrate the expected lymphatic drainage patterns of HNSCCA arising in the different subsites (nasopharynx, oropharynx, oral cavity, larynx, and hypopharynx) and 2) review the expected frequency of metastases within nodal groups for HNSCCA that arise in these locations. An understanding of the topographical distribution and incidence of cervical lymph node metastases plays an integral role in the physical examination and radiological evaluation of patients with HNSCCA. For the neuroradiologist, this information may increases the ability to identify those nodal groups at risk for metastatic involvement. Copyright 2001 John Wiley & Sons, Inc. Head Neck 23: 995-1005, 2001.

Saddle-like topological surface states on the T T'X family of compounds (T , T' = Transition metal, X =Si , Ge)

NASA Astrophysics Data System (ADS)

Singh, Bahadur; Zhou, Xiaoting; Lin, Hsin; Bansil, Arun

2018-02-01

Topological nodal-line semimetals are exotic conductors that host symmetry-protected conducting nodal lines in their bulk electronic spectrum and nontrivial drumhead states on the surface. Based on first-principles calculations and an effective model analysis, we identify the presence of topological nodal-line semimetal states in the low crystalline symmetric T T'X family of compounds (T ,T' = transition metal, X = Si or Ge) in the absence of spin-orbit coupling (SOC). Taking ZrPtGe as an exemplar system, we show that owing to small lattice symmetry this material harbors a single nodal line on the ky=0 plane with large energy dispersion and unique drumhead surface state with a saddlelike energy dispersion. When the SOC is included, the nodal line gaps out and the system transitions to a strong topological insulator state with Z2=(1 ;000 ) . The topological surface state evolves from the drumhead surface state via the sharing of its saddlelike energy dispersion within the bulk energy gap. These features differ remarkably from those of the currently known topological surface states in topological insulators such as Bi2Se3 with Dirac-cone-like energy dispersions.

Developmental changes in electrophysiological characteristics of human-induced pluripotent stem cell-derived cardiomyocytes.

PubMed

Ben-Ari, Meital; Naor, Shulamit; Zeevi-Levin, Naama; Schick, Revital; Ben Jehuda, Ronen; Reiter, Irina; Raveh, Amit; Grijnevitch, Inna; Barak, Omri; Rosen, Michael R; Weissman, Amir; Binah, Ofer

2016-12-01

Previous studies proposed that throughout differentiation of human induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs), only 3 types of action potentials (APs) exist: nodal-, atrial-, and ventricular-like. To investigate whether there are precisely 3 phenotypes or a continuum exists among them, we tested 2 hypotheses: (1) During culture development a cardiac precursor cell is present that-depending on age-can evolve into the 3 phenotypes. (2) The predominant pattern is early prevalence of a nodal phenotype, transient appearance of an atrial phenotype, evolution to a ventricular phenotype, and persistence of transitional phenotypes. To test these hypotheses, we (1) performed fluorescence-activated cell sorting analysis of nodal, atrial, and ventricular markers; (2) recorded APs from 280 7- to 95-day-old iPSC-CMs; and (3) analyzed AP characteristics. The major findings were as follows: (1) fluorescence-activated cell sorting analysis of 30- and 60-day-old cultures showed that an iPSC-CMs population shifts from the nodal to the atrial/ventricular phenotype while including significant transitional populations; (2) the AP population did not consist of 3 phenotypes; (3) culture aging was associated with a shift from nodal to ventricular dominance, with a transient (57-70 days) appearance of the atrial phenotype; and (4) beat rate variability was more prominent in nodal than in ventricular cardiomyocytes, while pacemaker current density increased in older cultures. From the onset of development in culture, the iPSC-CMs population includes nodal, atrial, and ventricular APs and a broad spectrum of transitional phenotypes. The most readily distinguishable phenotype is atrial, which appears only transiently yet dominates at 57-70 days of evolution. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Burner liner thermal/structural load modeling: TRANCITS program user's manual

NASA Technical Reports Server (NTRS)

Maffeo, R.

1985-01-01

Transfer Analysis Code to Interface Thermal/Structural Problems (TRANCITS) is discussed. The TRANCITS code satisfies all the objectives for transferring thermal data between heat transfer and structural models of combustor liners and it can be used as a generic thermal translator between heat transfer and stress models of any component, regardless of the geometry. The TRANCITS can accurately and efficiently convert the temperature distributions predicted by the heat transfer programs to those required by the stress codes. It can be used for both linear and nonlinear structural codes and can produce nodal temperatures, elemental centroid temperatures, or elemental Gauss point temperatures. The thermal output of both the MARC and SINDA heat transfer codes can be interfaced directly with TRANCITS, and it will automatically produce stress model codes formatted for NASTRAN and MARC. Any thermal program and structural program can be interfaced by using the neutral input and output forms supported by TRANCITS.

Topological and trivial magnetic oscillations in nodal loop semimetals

NASA Astrophysics Data System (ADS)

Oroszlány, László; Dóra, Balázs; Cserti, József; Cortijo, Alberto

2018-05-01

Nodal loop semimetals are close descendants of Weyl semimetals and possess a topologically dressed band structure. We argue by combining the conventional theory of magnetic oscillation with topological arguments that nodal loop semimetals host coexisting topological and trivial magnetic oscillations. These originate from mapping the topological properties of the extremal Fermi surface cross sections onto the physics of two dimensional semi-Dirac systems, stemming from merging two massless Dirac cones. By tuning the chemical potential and the direction of magnetic field, a sharp transition is identified from purely trivial oscillations, arising from the Landau levels of a normal two dimensional (2D) electron gas, to a phase where oscillations of topological and trivial origin coexist, originating from 2D massless Dirac and semi-Dirac points, respectively. These could in principle be directly identified in current experiments.

Constitutional rho-kinase regulates atrioventricular nodal conduction and ventricular repolarization of the canine heart.

PubMed

Sugiyama, Atsushi; Takahara, Akira; Yatomi, Yutaka; Satoh, Yoshioki; Nakamura, Yuji; Hashimoto, Keitaro

2003-06-01

Given the limited information, physiological roles of Rho-kinase in the cardiac conduction system and ventricular repolarization process were assessed in comparison with those in the coronary vascular tone. A specific Rho-kinase inhibitor Y-27632 was administered to the nutrient coronary artery of the canine isolated, blood-perfused atrioventricular node preparation under the monitoring of the ventricular monophasic action potentials. Administration of Y-27632 moderately suppressed the atrioventricular nodal conduction, slightly but significantly accelerated the repolarization process, and potently increased the coronary blood flow, whereas it hardly affected the intraventricular conduction. The estimated concentrations of Y-27632 causing the currently observed effects were enough to inhibit Rho-kinase. These results suggest that constitutional Rho-kinase functions to moderately facilitate the atrioventricular nodal conduction, slightly delay ventricular repolarization process, and significantly increase the coronary vascular tone.

Para-aortic nodal metastases in cervical cancer: a blind spot in the International Federation of Gynecology and Obstetrics staging system: current diagnosis and management.

PubMed

Hwang, Lindsay; Bailey, April; Lea, Jayanthi; Albuquerque, Kevin

2015-01-01

In cervical cancer, para-aortic nodal (PALN) metastases at presentation is a strong indicator of poor prognosis. Despite this, International Federation of Gynecology and Obstetrics staging system does not require evaluation of lymph node involvement and does not incorporate clinically detected PALN into the staging system. In the USA, despite screening, a significant number of women still present at an advanced stage often with nodal metastases. While the presence of PALN metastases often indicates occult systemic disease, it is possible with modern therapies to provide long-term control of disease in a percentage of patients. We review the epidemiology, diagnosis and treatment of PALN metastases in cervical cancer outlining advances in modern imaging and combined modality therapies (surgery, chemotherapy and radiation therapy).

Nodal Clearance Rate and Long-Term Efficacy of Individualized Sentinel Node–Based Pelvic Intensity Modulated Radiation Therapy for High-Risk Prostate Cancer

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

Müller, Arndt-Christian, E-mail: arndt-christian.mueller@med.uni-tuebingen.de; Eckert, Franziska; Paulsen, Frank

2016-02-01

Purpose: To assess the efficacy of individual sentinel node (SN)-guided pelvic intensity modulated radiation therapy (IMRT) by determining nodal clearance rate [(n expected nodal involvement − n observed regional recurrences)/n expected nodal involvement] in comparison with surgically staged patients. Methods and Materials: Data on 475 high-risk prostate cancer patients were examined. Sixty-one consecutive patients received pelvic SN-based IMRT (5 × 1.8 Gy/wk to 50.4 Gy [pelvic nodes + individual SN] and an integrated boost with 5 × 2.0 Gy/wk to 70.0 Gy to prostate + [base of] seminal vesicles) and neo-/adjuvant long-term androgen deprivation therapy; 414 patients after SN–pelvic lymph node dissection were used to calculate the expected nodal involvement rate for the radiation therapymore » sample. Biochemical control and overall survival were estimated for the SN-IMRT patients using the Kaplan-Meier method. The expected frequency of nodal involvement in the radiation therapy group was estimated by imputing frequencies of node-positive patients in the surgical sample to the pattern of Gleason, prostate-specific antigen, and T category in the radiation therapy sample. Results: After a median follow-up of 61 months, 5-year OS after SN-guided IMRT reached 84.4%. Biochemical control according to the Phoenix definition was 73.8%. The nodal clearance rate of SN-IMRT reached 94%. Retrospective follow-up evaluation is the main limitation. Conclusions: Radiation treatment of pelvic nodes individualized by inclusion of SNs is an effective regional treatment modality in high-risk prostate cancer patients. The pattern of relapse indicates that the SN-based target volume concept correctly covers individual pelvic nodes. Thus, this SN-based approach justifies further evaluation, including current dose-escalation strategies to the prostate in a larger prospective series.« less

Super-nodal methods for space-time kinetics

NASA Astrophysics Data System (ADS)

Mertyurek, Ugur

The purpose of this research has been to develop an advanced Super-Nodal method to reduce the run time of 3-D core neutronics models, such as in the NESTLE reactor core simulator and FORMOSA nuclear fuel management optimization codes. Computational performance of the neutronics model is increased by reducing the number of spatial nodes used in the core modeling. However, as the number of spatial nodes decreases, the error in the solution increases. The Super-Nodal method reduces the error associated with the use of coarse nodes in the analyses by providing a new set of cross sections and ADFs (Assembly Discontinuity Factors) for the new nodalization. These so called homogenization parameters are obtained by employing consistent collapsing technique. During this research a new type of singularity, namely "fundamental mode singularity", is addressed in the ANM (Analytical Nodal Method) solution. The "Coordinate Shifting" approach is developed as a method to address this singularity. Also, the "Buckling Shifting" approach is developed as an alternative and more accurate method to address the zero buckling singularity, which is a more common and well known singularity problem in the ANM solution. In the course of addressing the treatment of these singularities, an effort was made to provide better and more robust results from the Super-Nodal method by developing several new methods for determining the transverse leakage and collapsed diffusion coefficient, which generally are the two main approximations in the ANM methodology. Unfortunately, the proposed new transverse leakage and diffusion coefficient approximations failed to provide a consistent improvement to the current methodology. However, improvement in the Super-Nodal solution is achieved by updating the homogenization parameters at several time points during a transient. The update is achieved by employing a refinement technique similar to pin-power reconstruction. A simple error analysis based on the relative residual in the 3-D few group diffusion equation at the fine mesh level is also introduced in this work.

Flowfield-Dependent Mixed Explicit-Implicit (FDMEL) Algorithm for Computational Fluid Dynamics

NASA Technical Reports Server (NTRS)

Garcia, S. M.; Chung, T. J.

1997-01-01

Despite significant achievements in computational fluid dynamics, there still remain many fluid flow phenomena not well understood. For example, the prediction of temperature distributions is inaccurate when temperature gradients are high, particularly in shock wave turbulent boundary layer interactions close to the wall. Complexities of fluid flow phenomena include transition to turbulence, relaminarization separated flows, transition between viscous and inviscid incompressible and compressible flows, among others, in all speed regimes. The purpose of this paper is to introduce a new approach, called the Flowfield-Dependent Mixed Explicit-Implicit (FDMEI) method, in an attempt to resolve these difficult issues in Computational Fluid Dynamics (CFD). In this process, a total of six implicitness parameters characteristic of the current flowfield are introduced. They are calculated from the current flowfield or changes of Mach numbers, Reynolds numbers, Peclet numbers, and Damkoehler numbers (if reacting) at each nodal point and time step. This implies that every nodal point or element is provided with different or unique numerical scheme according to their current flowfield situations, whether compressible, incompressible, viscous, inviscid, laminar, turbulent, reacting, or nonreacting. In this procedure, discontinuities or fluctuations of an variables between adjacent nodal points are determined accurately. If these implicitness parameters are fixed to certain numbers instead of being calculated from the flowfield information, then practically all currently available schemes of finite differences or finite elements arise as special cases. Some benchmark problems to be presented in this paper will show the validity, accuracy, and efficiency of the proposed methodology.

Topological materials discovery using electron filling constraints

NASA Astrophysics Data System (ADS)

Chen, Ru; Po, Hoi Chun; Neaton, Jeffrey B.; Vishwanath, Ashvin

2018-01-01

Nodal semimetals are classes of topological materials that have nodal-point or nodal-line Fermi surfaces, which give them novel transport and topological properties. Despite being highly sought after, there are currently very few experimental realizations, and identifying new materials candidates has mainly relied on exhaustive database searches. Here we show how recent studies on the interplay between electron filling and nonsymmorphic space-group symmetries can guide the search for filling-enforced nodal semimetals. We recast the previously derived constraints on the allowed band-insulator fillings in any space group into a new form, which enables effective screening of materials candidates based solely on their space group, electron count in the formula unit, and multiplicity of the formula unit. This criterion greatly reduces the computation load for discovering topological materials in a database of previously synthesized compounds. As a demonstration, we focus on a few selected nonsymmorphic space groups which are predicted to host filling-enforced Dirac semimetals. Of the more than 30,000 entires listed, our filling criterion alone eliminates 96% of the entries before they are passed on for further analysis. We discover a handful of candidates from this guided search; among them, the monoclinic crystal Ca2Pt2Ga is particularly promising.

The 13 January 2001 El Salvador earthquake: A multidata analysis

NASA Astrophysics Data System (ADS)

ValléE, Martin; Bouchon, Michel; Schwartz, Susan Y.

2003-04-01

On 13 January 2001, a large normal faulting intermediate depth event (Mw = 7.7) occurred 40 km off the El Salvadorian coast (Central America). We analyze this earthquake using teleseismic, regional, and local data. We first build a kinematic source model by simultaneously inverting P and SH displacement waveforms and source time functions derived from surface waves using an empirical Green's function analysis. In an attempt to discriminate between the two nodal planes (30° trenchward dipping and 60° landward dipping), we perform identical inversions using both possible fault planes. After relocating the hypocentral depth at 54 km, we retrieve the kinematic features of the rupture using a combination of the Neighborhood algorithm of [1999] and the Simplex method allowing for variable rupture velocity and slip. We find updip rupture propagation yielding a centroid depth around 47 km for both assumed fault planes with a larger variance reduction obtained using the 60° landward dipping nodal plane. We test the two possible fault models using regional broadband data and near-field accelerograms provided by [2001]. Near-field data confirm that the steeper landward dipping nodal plane is preferred. Rupture propagated mostly updip and to the northwest, resulting in a main moment release zone of approximately 25 km × 50 km with an average slip of ˜3.5 m. The large slip occurs near the interplate interface at a location where the slab steepens dip significantly. The occurrence of this event is well-explained by bending of the subducting plate.

Observation of a nodal chain with Dirac surface states in Ti B2

NASA Astrophysics Data System (ADS)

Yi, C.-J.; Lv, B. Q.; Wu, Q. S.; Fu, B.-B.; Gao, X.; Yang, M.; Peng, X.-L.; Li, M.; Huang, Y.-B.; Richard, P.; Shi, M.; Li, G.; Yazyev, Oleg V.; Shi, Y.-G.; Qian, T.; Ding, H.

2018-05-01

Topological nodal-line semimetals (TNLSMs) are characterized by symmetry-protected band crossings extending along one-dimensional lines in momentum space. The nodal lines exhibit a variety of possible configurations, such as nodal ring, nodal link, nodal chain, and nodal knot. Here, using angle-resolved photoemission spectroscopy, we observe nodal rings on the orthogonal kz=0 and kx=0 planes of the Brillouin zone in Ti B2 . The nodal rings connect with each other on the intersecting line Γ-K of the orthogonal planes forming a remarkable nodal-chain structure. Furthermore, we observe surface states (SSs) on the (001) cleaved surface, which are consistent with the calculated SSs considering the contribution from both Ti and B terminations. The calculated SSs have novel Dirac-cone-like band structures, which are distinct from the usual drumhead SSs with a single flatband proposed in other TNLSMs.

Nodal surface semimetals: Theory and material realization

NASA Astrophysics Data System (ADS)

Wu, Weikang; Liu, Ying; Li, Si; Zhong, Chengyong; Yu, Zhi-Ming; Sheng, Xian-Lei; Zhao, Y. X.; Yang, Shengyuan A.

2018-03-01

We theoretically study the three-dimensional topological semimetals with nodal surfaces protected by crystalline symmetries. Different from the well-known nodal-point and nodal-line semimetals, in these materials, the conduction and valence bands cross on closed nodal surfaces in the Brillouin zone. We propose different classes of nodal surfaces, both in the absence and in the presence of spin-orbit coupling (SOC). In the absence of SOC, a class of nodal surfaces can be protected by space-time inversion symmetry and sublattice symmetry and characterized by a Z2 index, while another class of nodal surfaces are guaranteed by a combination of nonsymmorphic twofold screw-rotational symmetry and time-reversal symmetry. We show that the inclusion of SOC will destroy the former class of nodal surfaces but may preserve the latter provided that the inversion symmetry is broken. We further generalize the result to magnetically ordered systems and show that protected nodal surfaces can also exist in magnetic materials without and with SOC, given that certain magnetic group symmetry requirements are satisfied. Several concrete nodal-surface material examples are predicted via the first-principles calculations. The possibility of multi-nodal-surface materials is discussed.

Probability distribution for the Gaussian curvature of the zero level surface of a random function

NASA Astrophysics Data System (ADS)

Hannay, J. H.

2018-04-01

A rather natural construction for a smooth random surface in space is the level surface of value zero, or ‘nodal’ surface f(x,y,z)  =  0, of a (real) random function f; the interface between positive and negative regions of the function. A physically significant local attribute at a point of a curved surface is its Gaussian curvature (the product of its principal curvatures) because, when integrated over the surface it gives the Euler characteristic. Here the probability distribution for the Gaussian curvature at a random point on the nodal surface f  =  0 is calculated for a statistically homogeneous (‘stationary’) and isotropic zero mean Gaussian random function f. Capitalizing on the isotropy, a ‘fixer’ device for axes supplies the probability distribution directly as a multiple integral. Its evaluation yields an explicit algebraic function with a simple average. Indeed, this average Gaussian curvature has long been known. For a non-zero level surface instead of the nodal one, the probability distribution is not fully tractable, but is supplied as an integral expression.

Differential membranous E-cadherin expression, cell proliferation and O-GlcNAcylation between primary and metastatic nodal lesion in colorectal cancer.

PubMed

Jang, Tae Jung

2016-02-01

O-GlcNAcylation is an O-linked β-N-acetylglucosamine (O-GlcNAc) moiety linked to the side chain hydroxyl of a serine or threonine residue. The E-cadherin/β-catenin system, an integral component of epithelial to mesenchymal transition (EMT)/mesenchymal to epithelial transition (MET), is affected through O-GlcNAcylation. The current study examined the status of EMT/MET in both the tumor center and invasive front of the primary colorectal carcinoma (CRC) and metastatic nodal lesions, which were compared to O-GlcNAcylation expression levels in those areas. In addition, the cliniopathological significance of O-GlcNAcylation was studied Immunohistochemical staining for E-cadherin, β-catenin, Snail, O-GlcNAc and Ki67 was performed in 40 primary CRC tissues, 40 nonneoplastic colons, and 17 nodal metastatic lesions. Western blot was also conducted in primary CRC tissue Membranous E-cadherin expression was lowest in the invasive front, but showed greater increases in metastatic nodal lesions. Moreover, its expression level was negatively correlated with that of nuclear β-catenin and Snail. The Ki67 labeling index (LI) was lowest in the invasive front, and increased in metastatic nodal lesions. Primary CRC showed higher expression of O-GlcNAcylation and O-GlcNAc-transferase (OGT) than nonneoplastic colons. O-GlcNAcylation expression decreased in metastatic nodal lesions compared to the invasive front and tumor center, and was inversely correlated with Ki67 LI. However, O-GlcNAcylation expression was only slightly changed between tumor center and invasive front. In addition, there was no correlation between its expression and the level of nuclear β-catenin, membranous E-cadherin and Snail. No significant relationship was observed between O-GlcNAcylation level and cliniopathological parameters. Differential membranous E-cadherin expression, cell proliferation and O-GlcNAcylation in metastatic nodal lesion compared to primary CRC may play role in establishing its lesions; however, these findings are not sufficient to show the role of O-GlcNAcylation in the EMT/MET of CRC. Copyright © 2015 Elsevier GmbH. All rights reserved.

Experimental discovery of nodal chains

NASA Astrophysics Data System (ADS)

Yan, Qinghui; Liu, Rongjuan; Yan, Zhongbo; Liu, Boyuan; Chen, Hongsheng; Wang, Zhong; Lu, Ling

2018-05-01

Three-dimensional Weyl and Dirac nodal points1 have attracted widespread interest across multiple disciplines and in many platforms but allow for few structural variations. In contrast, nodal lines2-4 can have numerous topological configurations in momentum space, forming nodal rings5-9, nodal chains10-15, nodal links16-20 and nodal knots21,22. However, nodal lines are much less explored because of the lack of an ideal experimental realization23-25. For example, in condensed-matter systems, nodal lines are often fragile to spin-orbit coupling, located away from the Fermi level, coexist with energy-degenerate trivial bands or have a degeneracy line that disperses strongly in energy. Here, overcoming all these difficulties, we theoretically predict and experimentally observe nodal chains in a metallic-mesh photonic crystal having frequency-isolated linear band-touching rings chained across the entire Brillouin zone. These nodal chains are protected by mirror symmetry and have a frequency variation of less than 1%. We use angle-resolved transmission measurements to probe the projected bulk dispersion and perform Fourier-transformed field scans to map out the dispersion of the drumhead surface state. Our results establish an ideal nodal-line material for further study of topological line degeneracies with non-trivial connectivity and consequent wave dynamics that are richer than those in Weyl and Dirac materials.

TGF-β promotes glioma cell growth via activating Nodal expression through Smad and ERK1/2 pathways

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

Sun, Jing; Liu, Su-zhi; Lin, Yan

Highlights: •TGF-β promoted Nodal expression in glioma cells. •TGF-β promoted Nodal expression via activating Smad and ERK1/2 pathways. •TGF-β promotes glioma cell growth via activating Nodal expression. -- Abstract: While there were certain studies focusing on the mechanism of TGF-β promoting the growth of glioma cells, the present work revealed another novel mechanism that TGF-β may promote glioma cell growth via enhancing Nodal expression. Our results showed that Nodal expression was significantly upregulated in glioma cells when TGF-β was added, whereas the TGF-β-induced Nodal expression was evidently inhibited by transfection Smad2 or Smad3 siRNAs, and the suppression was especially significantmore » when the Smad3 was downregulated. Another, the attenuation of TGF-β-induced Nodal expression was observed with blockade of the ERK1/2 pathway also. Further detection of the proliferation, apoptosis, and invasion of glioma cells indicated that Nodal overexpression promoted the proliferation and invasion of tumor cells and inhibited their apoptosis, resembling the effect of TGF-β addition. Downregulation of Nodal expression via transfection Nodal-specific siRNA in the presence of TGF-β weakened the promoting effect of the latter on glioma cells growth, and transfecting Nodal siRNA alone in the absence of exogenous TGF-β more profoundly inhibited the growth of glioma cells. These results demonstrated that while both TGF-β and Nodal promoted glioma cells growth, the former might exert such effect by enhancing Nodal expression, which may form a new target for glioma therapy.« less

Nodal domains of a non-separable problem—the right-angled isosceles triangle

NASA Astrophysics Data System (ADS)

Aronovitch, Amit; Band, Ram; Fajman, David; Gnutzmann, Sven

2012-03-01

We study the nodal set of eigenfunctions of the Laplace operator on the right-angled isosceles triangle. A local analysis of the nodal pattern provides an algorithm for computing the number νn of nodal domains for any eigenfunction. In addition, an exact recursive formula for the number of nodal domains is found to reproduce all existing data. Eventually, we use the recursion formula to analyse a large sequence of nodal counts statistically. Our analysis shows that the distribution of nodal counts for this triangular shape has a much richer structure than the known cases of regular separable shapes or completely irregular shapes. Furthermore, we demonstrate that the nodal count sequence contains information about the periodic orbits of the corresponding classical ray dynamics.

Reactivation of Embryonic Nodal Signaling is Associated with Tumor Progression and Promotes the Growth of Prostate Cancer Cells

PubMed Central

Lawrence, Mitchell G.; Margaryan, Naira V.; Loessner, Daniela; Collins, Angus; Kerr, Kris M.; Turner, Megan; Seftor, Elisabeth A.; Stephens, Carson R.; Lai, John; BioResource, APC; Postovit, Lynne-Marie; Clements, Judith A.; Hendrix, Mary J.C.

2011-01-01

Background Nodal is a member of the Transforming Growth Factor β (TGFβ) superfamily that directs embryonic patterning and promotes the plasticity and tumorigenicity of tumor cells, but its role in the prostate is unknown. The goal of this study was to characterize the expression and function of Nodal in prostate cancer and determine whether, like other TGFβ ligands, it modulates androgen receptor (AR) activity. Methods Nodal expression was investigated using immunohistochemistry of tissue microarrays and Western blots of prostate cell lines. The functional role of Nodal was examined using Matrigel and soft agar growth assays. Cross-talk between Nodal and AR signaling was assessed with luciferase reporter assays and expression of endogenous androgen regulated genes. Results Significantly increased Nodal expression was observed in cancer compared with benign prostate specimens. Nodal was only expressed by DU145 and PC3 cells. All cell lines expressed Nodal’s co-receptor, Cripto-1, but lacked Lefty, a critical negative regulator of Nodal signaling. Recombinant human Nodal triggered downstream Smad2 phosphorylation in DU145 and LNCaP cells, and stable transfection of pre-pro-Nodal enhanced the growth of LNCaP cells in Matrigel and soft agar. Finally, Nodal attenuated AR signaling, reducing the activity of a PSA promoter construct in luciferase assays and down-regulating the endogenous expression of androgen regulated genes. Conclusions An aberrant Nodal signaling pathway is re-expressed and functionally active in prostate cancer cells. PMID:21656830

Observation of topological nodal fermion semimetal phase in ZrSiS

DOE PAGES

Neupane, Madhab; Belopolski, Ilya; Hosen, M. Mofazzel; ...

2016-05-11

We present that unveiling new topological phases of matter is one of the current objectives in condensed matter physics. Recent experimental discoveries of Dirac and Weyl semimetals prompt the search for other exotic phases of matter. Here we present a systematic angle-resolved photoemission spectroscopy study of ZrSiS, a prime topological nodal semimetal candidate. Our wider Brillouin zone (BZ) mapping shows multiple Fermi surface pockets such as the diamond-shaped Fermi surface, elliptical-shaped Fermi surface, and a small electron pocket encircling at the zone center (Γ) point, the M point, and the X point of the BZ, respectively. We experimentally establish themore » spinless nodal fermion semimetal phase in ZrSiS, which is supported by our first-principles calculations. Our findings evidence that the ZrSiS-type of material family is a new platform on which to explore exotic states of quantum matter; these materials are expected to provide an avenue for engineering two-dimensional topological insulator systems.« less

The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development.

PubMed

Reissmann, E; Jörnvall, H; Blokzijl, A; Andersson, O; Chang, C; Minchiotti, G; Persico, M G; Ibáñez, C F; Brivanlou, A H

2001-08-01

Nodal proteins have crucial roles in mesendoderm formation and left-right patterning during vertebrate development. The molecular mechanisms of signal transduction by Nodal and related ligands, however, are not fully understood. In this paper, we present biochemical and functional evidence that the orphan type I serine/threonine kinase receptor ALK7 acts as a receptor for mouse Nodal and Xenopus Nodal-related 1 (Xnr1). Receptor reconstitution experiments indicate that ALK7 collaborates with ActRIIB to confer responsiveness to Xnr1 and Nodal. Both receptors can independently bind Xnr1. In addition, Cripto, an extracellular protein genetically implicated in Nodal signaling, can independently interact with both Xnr1 and ALK7, and its expression greatly enhances the ability of ALK7 and ActRIIB to respond to Nodal ligands. The Activin receptor ALK4 is also able to mediate Nodal signaling but only in the presence of Cripto, with which it can also interact directly. A constitutively activated form of ALK7 mimics the mesendoderm-inducing activity of Xnr1 in Xenopus embryos, whereas a dominant-negative ALK7 specifically blocks the activities of Nodal and Xnr1 but has little effect on other related ligands. In contrast, a dominant-negative ALK4 blocks all mesoderm-inducing ligands tested, including Nodal, Xnr1, Xnr2, Xnr4, and Activin. In agreement with a role in Nodal signaling, ALK7 mRNA is localized to the ectodermal and organizer regions of Xenopus gastrula embryos and is expressed during early stages of mouse embryonic development. Therefore, our results indicate that both ALK4 and ALK7 can mediate signal transduction by Nodal proteins, although ALK7 appears to be a receptor more specifically dedicated to Nodal signaling.

The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development

PubMed Central

Reissmann, Eva; Jörnvall, Henrik; Blokzijl, Andries; Andersson, Olov; Chang, Chenbei; Minchiotti, Gabriella; Persico, M. Graziella; Ibáñez, Carlos F.; Brivanlou, Ali H.

2001-01-01

Nodal proteins have crucial roles in mesendoderm formation and left–right patterning during vertebrate development. The molecular mechanisms of signal transduction by Nodal and related ligands, however, are not fully understood. In this paper, we present biochemical and functional evidence that the orphan type I serine/threonine kinase receptor ALK7 acts as a receptor for mouse Nodal and Xenopus Nodal-related 1 (Xnr1). Receptor reconstitution experiments indicate that ALK7 collaborates with ActRIIB to confer responsiveness to Xnr1 and Nodal. Both receptors can independently bind Xnr1. In addition, Cripto, an extracellular protein genetically implicated in Nodal signaling, can independently interact with both Xnr1 and ALK7, and its expression greatly enhances the ability of ALK7 and ActRIIB to respond to Nodal ligands. The Activin receptor ALK4 is also able to mediate Nodal signaling but only in the presence of Cripto, with which it can also interact directly. A constitutively activated form of ALK7 mimics the mesendoderm-inducing activity of Xnr1 in Xenopus embryos, whereas a dominant-negative ALK7 specifically blocks the activities of Nodal and Xnr1 but has little effect on other related ligands. In contrast, a dominant-negative ALK4 blocks all mesoderm-inducing ligands tested, including Nodal, Xnr1, Xnr2, Xnr4, and Activin. In agreement with a role in Nodal signaling, ALK7 mRNA is localized to the ectodermal and organizer regions of Xenopus gastrula embryos and is expressed during early stages of mouse embryonic development. Therefore, our results indicate that both ALK4 and ALK7 can mediate signal transduction by Nodal proteins, although ALK7 appears to be a receptor more specifically dedicated to Nodal signaling. PMID:11485994

Optical Interface States Protected by Synthetic Weyl Points

NASA Astrophysics Data System (ADS)

Wang, Qiang; Xiao, Meng; Liu, Hui; Zhu, Shining; Chan, C. T.

2017-07-01

Weyl fermions have not been found in nature as elementary particles, but they emerge as nodal points in the band structure of electronic and classical wave crystals. Novel phenomena such as Fermi arcs and chiral anomaly have fueled the interest in these topological points which are frequently perceived as monopoles in momentum space. Here, we report the experimental observation of generalized optical Weyl points inside the parameter space of a photonic crystal with a specially designed four-layer unit cell. The reflection at the surface of a truncated photonic crystal exhibits phase vortexes due to the synthetic Weyl points, which in turn guarantees the existence of interface states between photonic crystals and any reflecting substrates. The reflection phase vortexes have been confirmed for the first time in our experiments, which serve as an experimental signature of the generalized Weyl points. The existence of these interface states is protected by the topological properties of the Weyl points, and the trajectories of these states in the parameter space resembles those of Weyl semimetal "Fermi arc surface states" in momentum space. Tracing the origin of interface states to the topological character of the parameter space paves the way for a rational design of strongly localized states with enhanced local field.

Revisiting the physical characterisitics of the subduction interplate seismogenic zones

NASA Astrophysics Data System (ADS)

Heuret, Arnauld; Lallemand, Serge; Funiciello, Francesca; Piromallo, Claudia

2010-05-01

Based on the Centennial earthquake catalog, the revised 1964-2007 EHB hypocenters catalog and the 1976-2007 CMT Harvard catalog, we have extracted the hypocenters, nodal planes and seismic moments of worldwide subduction earthquakes for the 1900-2007 period. For the 1976-2007 period, we combine the focal solutions provided by Harvard and the revised hypocenters from Engdahl et al. (1998). Older events are extracted from the Centennial catalogue (Engdahl and Villasenor, 2002) and they are used to estimate the cumulated seismic moment only. The selection criteria for the subduction earthquakes are similar to those used by Mc Caffrey (1994), i.e., we test if the focal mechanisms are consistent with 1/ shallow thrust events (depth > 70 km, positive slips, and at least one nodal plane gets dip < 45°), and, 2/ the plate interface local geometry and orientation (one nodal plane is oriented toward the volcanic arc, the azimuth of this nodal plane ranges between ± 45° with respect to the trench one, its dip ranges between ± 20° with respect to the slab one and the epicentre is located seaward of the volcanic arc). Our study concerns segments of subduction zones that fit with estimated paleoruptures associated with major events (M > 8). We assume that the seismogenic zone coincides with the distribution of 5.5 < M < 7 subduction earthquakes. We provide a map of the interplate seismogenic zones for 80% of the trench systems including dip, length, downdip and updip limits, we revisit the statistical study done by Pacheco et al. (1993) and test some empirical laws obtained for example by Ruff and Kanamori (1980) in light of a more complete, detailed, accurate and uniform description of the subduction interplate seismogenic zone. Since subduction earthquakes result from stress accumulation along the interplate and stress depends on plates kinematics, subduction zone geometry, thermal state and seismic coupling, we aim to isolate some correlations between parameters. The statistical analysis reveals that: 1- vs, the subduction velocity is the first order controlling parameter of seismogenic zone variability, both in term of geometry and seismic behaviour; 2- steep dip, large vertical extent and narrow horizontal extent of the seismogenic zone are associated to fast subductions, and cold slabs, the opposite holding for slow subductions and warm slabs; the seismogenic zone usually ends in the fore-arc mantle rather than at the upper plate Moho depth; 3- seismic rate () variability is coherent with the geometry of the seismogenic zone:  increases with the dip and with the vertical extent of the seismogenic zone, and it fits with vs and with the subducting plate thermal state; 4- mega-events occurrence determines the level of seismic energy released along the subduction interface, whatever  is; 5- to some extent, the potential size of earthquakes fits with vs and with the seismogenic zone geometry, but second order controlling parameters are more difficult to detect; 6- the plate coupling, measured through Upper Plate Strain, is one possible second order parameter: mega-events are preferentially associated to neutral subductions, i.e. moderate compressive stresses along the plate interface; high plate coupling (compressive UPS) is thought to inhibit mega-events genesis by enhancing the locking of the plate interface and preventing the rupture to extend laterally. This research was supported as part of the Eurohorcs/ESF — European Young Investigators Awards Scheme (resp. F.F.), by funds from the National Research Council of Italy and other National Funding Agencies participating in the 3rd Memorandum of Understanding, as well as from the EC Sixth Framework Programme.

Spinless hourglass nodal-line semimetals

NASA Astrophysics Data System (ADS)

Takahashi, Ryo; Hirayama, Motoaki; Murakami, Shuichi

2017-10-01

Nodal-line semimetals, one of the topological semimetals, have degeneracy along nodal lines where the band gap is closed. In many cases, the nodal lines appear accidentally, and in such cases it is impossible to determine whether the nodal lines appear or not, only from the crystal symmetry and the electron filling. In this paper, for spinless systems, we show that in specific space groups at 4 N +2 fillings (8 N +4 fillings including the spin degree of freedom), presence of the nodal lines is required regardless of the details of the systems. Here, the spinless systems refer to crystals where the spin-orbit coupling is negligible and the spin degree of freedom can be omitted because of the SU(2) spin degeneracy. In this case the shape of the band structure around these nodal lines is like an hourglass, and we call this a spinless hourglass nodal-line semimetal. We construct a model Hamiltonian as an example and we show that it is always in the spinless hourglass nodal-line semimetal phase even when the model parameters are changed without changing the symmetries of the system. We also establish a list of all the centrosymmetric space groups, under which spinless systems always have hourglass nodal lines, and illustrate where the nodal lines are located. We propose that Al3FeSi2 , whose space-group symmetry is Pbcn (No. 60), is one of the nodal-line semimetals arising from this mechanism.

Response of millet and sorghum to a varying water supply around the primary and nodal roots

PubMed Central

Rostamza, M.; Richards, R. A.; Watt, M.

2013-01-01

Background and Aims Cereals have two root systems. The primary system originates from the embryo when the seed germinates and can support the plant until it produces grain. The nodal system can emerge from stem nodes throughout the plant's life; its value for yield is unclear and depends on the environment. The aim of this study was to test the role of nodal roots of sorghum and millet in plant growth in response to variation in soil moisture. Sorghum and millet were chosen as both are adapted to dry conditions. Methods Sorghum and millet were grown in a split-pot system that allowed the primary and nodal roots to be watered separately. Key Results When primary and nodal roots were watered (12 % soil water content; SWC), millet nodal roots were seven times longer than those of sorghum and six times longer than millet plants in dry treatments, mainly from an 8-fold increase in branch root length. When soil was allowed to dry in both compartments, millet nodal roots responded and grew 20 % longer branch roots than in the well-watered control. Sorghum nodal roots were unchanged. When only primary roots received water, nodal roots of both species emerged and elongated into extremely dry soil (0·6–1·5 % SWC), possibly with phloem-delivered water from the primary roots in the moist inner pot. Nodal roots were thick, short, branchless and vertical, indicating a tropism that was more pronounced in millet. Total nodal root length increased in both species when the dry soil was covered with plastic, suggesting that stubble retention or leaf mulching could facilitate nodal roots reaching deeper moist layers in dry climates. Greater nodal root length in millet than in sorghum was associated with increased shoot biomass, water uptake and water use efficiency (shoot mass per water). Millet had a more plastic response than sorghum to moisture around the nodal roots due to (1) faster growth and progression through ontogeny for earlier nodal root branch length and (2) partitioning to nodal root length from primary roots, independent of shoot size. Conclusions Nodal and primary roots have distinct responses to soil moisture that depend on species. They can be selected independently in a breeding programme to shape root architecture. A rapid rate of plant development and enhanced responsiveness to local moisture may be traits that favour nodal roots and water use efficiency at no cost to shoot growth. PMID:23749473

Response of millet and sorghum to a varying water supply around the primary and nodal roots.

PubMed

Rostamza, M; Richards, R A; Watt, M

2013-07-01

Cereals have two root systems. The primary system originates from the embryo when the seed germinates and can support the plant until it produces grain. The nodal system can emerge from stem nodes throughout the plant's life; its value for yield is unclear and depends on the environment. The aim of this study was to test the role of nodal roots of sorghum and millet in plant growth in response to variation in soil moisture. Sorghum and millet were chosen as both are adapted to dry conditions. Sorghum and millet were grown in a split-pot system that allowed the primary and nodal roots to be watered separately. When primary and nodal roots were watered (12 % soil water content; SWC), millet nodal roots were seven times longer than those of sorghum and six times longer than millet plants in dry treatments, mainly from an 8-fold increase in branch root length. When soil was allowed to dry in both compartments, millet nodal roots responded and grew 20 % longer branch roots than in the well-watered control. Sorghum nodal roots were unchanged. When only primary roots received water, nodal roots of both species emerged and elongated into extremely dry soil (0.6-1.5 % SWC), possibly with phloem-delivered water from the primary roots in the moist inner pot. Nodal roots were thick, short, branchless and vertical, indicating a tropism that was more pronounced in millet. Total nodal root length increased in both species when the dry soil was covered with plastic, suggesting that stubble retention or leaf mulching could facilitate nodal roots reaching deeper moist layers in dry climates. Greater nodal root length in millet than in sorghum was associated with increased shoot biomass, water uptake and water use efficiency (shoot mass per water). Millet had a more plastic response than sorghum to moisture around the nodal roots due to (1) faster growth and progression through ontogeny for earlier nodal root branch length and (2) partitioning to nodal root length from primary roots, independent of shoot size. Nodal and primary roots have distinct responses to soil moisture that depend on species. They can be selected independently in a breeding programme to shape root architecture. A rapid rate of plant development and enhanced responsiveness to local moisture may be traits that favour nodal roots and water use efficiency at no cost to shoot growth.

Risk of Nodal Metastasis in Major Salivary Gland Adenoid Cystic Carcinoma.

PubMed

Megwalu, Uchechukwu C; Sirjani, Davud

2017-04-01

Objective To determine the risk of nodal metastasis, examine risk factors for nodal metastasis, and evaluate the impact of nodal metastasis on survival in patients with major salivary gland adenoid cystic carcinoma. Study Design Retrospective cohort study from a large population- based cancer database. Methods Data were extracted from the SEER 18 database (Surveillance, Epidemiology, and End Results) of the National Cancer Institute. The study cohort included 720 patients diagnosed with major salivary gland adenoid cystic carcinoma between 1988 and 2013. Results The overall rate of lymph node metastasis was 17%. T3 disease (odds ratio, 4.74) and T4 disease (odds ratio, 9.24) were associated with increased risk of nodal metastasis. Age, sex, and site were not associated with nodal metastasis. Nodal metastasis was associated with worse overall survival (hazard ratio, 2.56) and disease-specific survival (hazard ratio, 3.27), after adjusting for T stage, presence of distant metastasis, site, surgical resection, radiotherapy, neck dissection, age, sex, race, marital status, and year of diagnosis. Conclusion Major salivary gland adenoid cystic carcinoma carries significant risk of nodal metastasis. Advanced T stage is associated with increased risk of nodal metastasis. Nodal metastasis is associated with worse survival.

Implications of improved diagnostic imaging of small nodal metastases in head and neck cancer: Radiotherapy target volume transformation and dose de-escalation.

PubMed

van den Bosch, Sven; Vogel, Wouter V; Raaijmakers, Cornelis P; Dijkema, Tim; Terhaard, Chris H J; Al-Mamgani, Abrahim; Kaanders, Johannes H A M

2018-05-03

Diagnostic imaging continues to evolve, and now has unprecedented accuracy for detecting small nodal metastasis. This influences the tumor load in elective target volumes and subsequently has consequences for the radiotherapy dose required to control disease in these volumes. Small metastases that used to remain subclinical and were included in elective volumes, will nowadays be detected and included in high-dose volumes. Consequentially, high-dose volumes will more often contain low-volume disease. These target volume transformations lead to changes in the tumor burden in elective and "gross" tumor volumes with implications for the radiotherapy dose prescribed to these volumes. For head and neck tumors, nodal staging has evolved from mere palpation to combinations of high-resolution imaging modalities. A traditional nodal gross tumor volume in the neck typically had a minimum diameter of 10-15 mm, while nowadays much smaller tumor deposits are detected in lymph nodes. However, the current dose levels for elective nodal irradiation were empirically determined in the 1950s, and have not changed since. In this report the radiobiological consequences of target volume transformation caused by modern imaging of the neck are evaluated, and theoretically derived reductions of dose in radiotherapy for head and neck cancer are proposed. The concept of target volume transformation and subsequent strategies for dose adaptation applies to many other tumor types as well. Awareness of this concept may result in new strategies for target definition and selection of dose levels with the aim to provide optimal tumor control with less toxicity. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Surface and 3D Quantum Hall Effects from Engineering of Exceptional Points in Nodal-Line Semimetals

NASA Astrophysics Data System (ADS)

Molina, Rafael A.; González, José

2018-04-01

We show that, under a strong magnetic field, a 3D nodal-line semimetal is driven into a topological insulating phase in which the electronic transport takes place at the surface of the material. When the magnetic field is perpendicular to the nodal ring, the surface states of the semimetal are transmuted into Landau states which correspond to exceptional points, i.e., branch points in the spectrum of a non-Hermitian Hamiltonian which arise upon the extension to complex values of the momentum. The complex structure of the spectrum then allows us to express the number of zero-energy flat bands in terms of a new topological invariant counting the number of exceptional points. When the magnetic field is parallel to the nodal ring, we find that the bulk states are built from the pairing of surfacelike evanescent waves, giving rise to a 3D quantum Hall effect with a flat level of Landau states residing in parallel 2D slices of the 3D material. The Hall conductance is quantized in either case in units of e2/h , leading in the 3D Hall effect to a number of channels growing linearly with the section of the surface and opening the possibility to observe a macroscopic chiral current at the surface of the material.

Plasticity in nodal root elongation through the hardpan triggered by rewatering during soil moisture fluctuation stress in rice.

PubMed

Suralta, Roel Rodriguez; Niones, Jonathan Manito; Kano-Nakata, Mana; Thi Tran, Thiem; Mitsuya, Shiro; Yamauchi, Akira

2018-03-12

Rainfed lowland (RFL) rice fields have hardpans and experience soil moisture fluctuations (SMF) stress, which influence root system development. Here, we clarify the expression and timing of the plasticity in nodal root elongation through the hardpan under SMF and its contribution to shoot growth using a shallow-rooting IR64 and its deep-rooting introgression line, YTH304. Under SMF, soil moisture content had negative relationship with soil penetration resistance, regardless of hardpan bulk densities. YTH304 had greater root system below the hardpan than IR64 in hardpan with 1.50 but not in 1.70 g cm -3 bulk density (BD). YTH304 had greater plasticity in nodal root elongation through the hardpan than IR64 under SMF, which was clearly expressed during rewatering. YTH304 also had greater soil water uptake below the hardpan during drought and greater shoot growth than IR64. The results imply that deep root system development during SMF was due to the plasticity in nodal root elongation through the hardpan expressed during rewatering rather than during drought periods. This is against the long standing belief that active root elongation through the hardpan happens during drought. This also implies a need to revisit current root screening methods to identify rice lines with good hardpan penetration ability.

Incidence of isolated nodal failure in non-small cell lung cancer patients included in a prospective study of the value of PET-CT.

PubMed

Kolodziejczyk, Milena; Bujko, Krzysztof; Michalski, Wojciech; Kepka, Lucyna

2012-07-01

Elective nodal irradiation (ENI) is not recommended in PET-CT-based radiotherapy for NSCLC despite a low level of evidence to support such guidelines. The aim of this investigation is to find out whether omitting ENI is safe. Sixty-seven patients treated within a frame of a previously published prospective trial of the value of PET-CT were included in the analysis. Seventeen (25%) patients received ENI due to higher initial nodal involvement and in the remaining 50 patients (75%) with N0-N1 or single N2 disease ENI was omitted. Isolated nodal failure (INF) was recorded if relapse occurred in the initially uninvolved regional lymph node without previous or simultaneous local recurrence regardless of the status of distant metastases. With a median follow-up of 32 months, the estimated 3-year overall survival was 42%, local progression-free interval was 55%, and distant metastases-free interval was 62%. Three patients developed INF; all had ENI omitted from treatment, giving a final result of three INFs in 50 (6%) patients treated without ENI. In this group of patients, the 3-year cause-specific cumulative incidence of INF was 6.4% (95% confidence interval: 0-17%). The omission of ENI appears to be not as safe as suggested by current recommendations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Automatic two- and three-dimensional mesh generation based on fuzzy knowledge processing

NASA Astrophysics Data System (ADS)

Yagawa, G.; Yoshimura, S.; Soneda, N.; Nakao, K.

1992-09-01

This paper describes the development of a novel automatic FEM mesh generation algorithm based on the fuzzy knowledge processing technique. A number of local nodal patterns are stored in a nodal pattern database of the mesh generation system. These nodal patterns are determined a priori based on certain theories or past experience of experts of FEM analyses. For example, such human experts can determine certain nodal patterns suitable for stress concentration analyses of cracks, corners, holes and so on. Each nodal pattern possesses a membership function and a procedure of node placement according to this function. In the cases of the nodal patterns for stress concentration regions, the membership function which is utilized in the fuzzy knowledge processing has two meanings, i.e. the “closeness” of nodal location to each stress concentration field as well as “nodal density”. This is attributed to the fact that a denser nodal pattern is required near a stress concentration field. What a user has to do in a practical mesh generation process are to choose several local nodal patterns properly and to designate the maximum nodal density of each pattern. After those simple operations by the user, the system places the chosen nodal patterns automatically in an analysis domain and on its boundary, and connects them smoothly by the fuzzy knowledge processing technique. Then triangular or tetrahedral elements are generated by means of the advancing front method. The key issue of the present algorithm is an easy control of complex two- or three-dimensional nodal density distribution by means of the fuzzy knowledge processing technique. To demonstrate fundamental performances of the present algorithm, a prototype system was constructed with one of object-oriented languages, Smalltalk-80 on a 32-bit microcomputer, Macintosh II. The mesh generation of several two- and three-dimensional domains with cracks, holes and junctions was presented as examples.

A nodal discontinuous Galerkin approach to 3-D viscoelastic wave propagation in complex geological media

NASA Astrophysics Data System (ADS)

Lambrecht, L.; Lamert, A.; Friederich, W.; Möller, T.; Boxberg, M. S.

2018-03-01

A nodal discontinuous Galerkin (NDG) approach is developed and implemented for the computation of viscoelastic wavefields in complex geological media. The NDG approach combines unstructured tetrahedral meshes with an element-wise, high-order spatial interpolation of the wavefield based on Lagrange polynomials. Numerical fluxes are computed from an exact solution of the heterogeneous Riemann problem. Our implementation offers capabilities for modelling viscoelastic wave propagation in 1-D, 2-D and 3-D settings of very different spatial scale with little logistical overhead. It allows the import of external tetrahedral meshes provided by independent meshing software and can be run in a parallel computing environment. Computation of adjoint wavefields and an interface for the computation of waveform sensitivity kernels are offered. The method is validated in 2-D and 3-D by comparison to analytical solutions and results from a spectral element method. The capabilities of the NDG method are demonstrated through a 3-D example case taken from tunnel seismics which considers high-frequency elastic wave propagation around a curved underground tunnel cutting through inclined and faulted sedimentary strata. The NDG method was coded into the open-source software package NEXD and is available from GitHub.

Chiral topological insulating phases from three-dimensional nodal loop semimetals

NASA Astrophysics Data System (ADS)

Li, Linhu; Yin, Chuanhao; Chen, Shu; Araujo, Miguel

We begin with a minimal model of three-dimensional nodal loop semimetals, and study the effect of anticommuting gap terms. The resulting topological insulating phases are protected by a chiral symmetry, and can be characterized by a winding number defined along the nodal loop. We illustrate the geometric relation between the nodal loop and the gap terms, which has a correspondence to the nodal loop winding number. We further investigate a lattice model and study its edge states under open boundary condition. The edge states hold Dirac cones with the same number as the summation of the winding numbers of each nodal loop in the first Brillouin zone.

Rules for Phase Shifts of Quantum Oscillations in Topological Nodal-Line Semimetals

NASA Astrophysics Data System (ADS)

Li, Cequn; Wang, C. M.; Wan, Bo; Wan, Xiangang; Lu, Hai-Zhou; Xie, X. C.

2018-04-01

Nodal-line semimetals are topological semimetals in which band touchings form nodal lines or rings. Around a loop that encloses a nodal line, an electron can accumulate a nontrivial π Berry phase, so the phase shift in the Shubnikov-de Haas (SdH) oscillation may give a transport signature for the nodal-line semimetals. However, different experiments have reported contradictory phase shifts, in particular, in the WHM nodal-line semimetals (W =Zr /Hf , H =Si /Ge , M =S /Se /Te ). For a generic model of nodal-line semimetals, we present a systematic calculation for the SdH oscillation of resistivity under a magnetic field normal to the nodal-line plane. From the analytical result of the resistivity, we extract general rules to determine the phase shifts for arbitrary cases and apply them to ZrSiS and Cu3 PdN systems. Depending on the magnetic field directions, carrier types, and cross sections of the Fermi surface, the phase shift shows rich results, quite different from those for normal electrons and Weyl fermions. Our results may help explore transport signatures of topological nodal-line semimetals and can be generalized to other topological phases of matter.

Applying Dispersive Changes to Lagrangian Particles in Groundwater Transport Models

USGS Publications Warehouse

Konikow, Leonard F.

2010-01-01

Method-of-characteristics groundwater transport models require that changes in concentrations computed within an Eulerian framework to account for dispersion be transferred to moving particles used to simulate advective transport. A new algorithm was developed to accomplish this transfer between nodal values and advecting particles more precisely and realistically compared to currently used methods. The new method scales the changes and adjustments of particle concentrations relative to limiting bounds of concentration values determined from the population of adjacent nodal values. The method precludes unrealistic undershoot or overshoot for concentrations of individual particles. In the new method, if dispersion causes cell concentrations to decrease during a time step, those particles in the cell having the highest concentration will decrease the most, and those with the lowest concentration will decrease the least. The converse is true if dispersion is causing concentrations to increase. Furthermore, if the initial concentration on a particle is outside the range of the adjacent nodal values, it will automatically be adjusted in the direction of the acceptable range of values. The new method is inherently mass conservative. ?? US Government 2010.

Applying dispersive changes to Lagrangian particles in groundwater transport models

USGS Publications Warehouse

Konikow, Leonard F.

2010-01-01

Method-of-characteristics groundwater transport models require that changes in concentrations computed within an Eulerian framework to account for dispersion be transferred to moving particles used to simulate advective transport. A new algorithm was developed to accomplish this transfer between nodal values and advecting particles more precisely and realistically compared to currently used methods. The new method scales the changes and adjustments of particle concentrations relative to limiting bounds of concentration values determined from the population of adjacent nodal values. The method precludes unrealistic undershoot or overshoot for concentrations of individual particles. In the new method, if dispersion causes cell concentrations to decrease during a time step, those particles in the cell having the highest concentration will decrease the most, and those with the lowest concentration will decrease the least. The converse is true if dispersion is causing concentrations to increase. Furthermore, if the initial concentration on a particle is outside the range of the adjacent nodal values, it will automatically be adjusted in the direction of the acceptable range of values. The new method is inherently mass conservative.

PAGANI Toolkit: Parallel graph-theoretical analysis package for brain network big data.

PubMed

Du, Haixiao; Xia, Mingrui; Zhao, Kang; Liao, Xuhong; Yang, Huazhong; Wang, Yu; He, Yong

2018-05-01

The recent collection of unprecedented quantities of neuroimaging data with high spatial resolution has led to brain network big data. However, a toolkit for fast and scalable computational solutions is still lacking. Here, we developed the PArallel Graph-theoretical ANalysIs (PAGANI) Toolkit based on a hybrid central processing unit-graphics processing unit (CPU-GPU) framework with a graphical user interface to facilitate the mapping and characterization of high-resolution brain networks. Specifically, the toolkit provides flexible parameters for users to customize computations of graph metrics in brain network analyses. As an empirical example, the PAGANI Toolkit was applied to individual voxel-based brain networks with ∼200,000 nodes that were derived from a resting-state fMRI dataset of 624 healthy young adults from the Human Connectome Project. Using a personal computer, this toolbox completed all computations in ∼27 h for one subject, which is markedly less than the 118 h required with a single-thread implementation. The voxel-based functional brain networks exhibited prominent small-world characteristics and densely connected hubs, which were mainly located in the medial and lateral fronto-parietal cortices. Moreover, the female group had significantly higher modularity and nodal betweenness centrality mainly in the medial/lateral fronto-parietal and occipital cortices than the male group. Significant correlations between the intelligence quotient and nodal metrics were also observed in several frontal regions. Collectively, the PAGANI Toolkit shows high computational performance and good scalability for analyzing connectome big data and provides a friendly interface without the complicated configuration of computing environments, thereby facilitating high-resolution connectomics research in health and disease. © 2018 Wiley Periodicals, Inc.

Targeting nodal in conjunction with dacarbazine induces synergistic anticancer effects in metastatic melanoma.

PubMed

Hardy, Katharine M; Strizzi, Luigi; Margaryan, Naira V; Gupta, Kanika; Murphy, George F; Scolyer, Richard A; Hendrix, Mary J C

2015-04-01

Metastatic melanoma is a highly aggressive skin cancer with a poor prognosis. Despite a complete response in fewer than 5% of patients, the chemotherapeutic agent dacarbazine (DTIC) remains the reference drug after almost 40 years. More recently, FDA-approved drugs have shown promise but patient outcome remains modest, predominantly due to drug resistance. As such, combinatorial targeting has received increased attention, and will advance with the identification of new molecular targets. One attractive target for improving melanoma therapy is the growth factor Nodal, whose normal expression is largely restricted to embryonic development, but is reactivated in metastatic melanoma. In this study, we sought to determine how Nodal-positive human melanoma cells respond to DTIC treatment and to ascertain whether targeting Nodal in combination with DTIC would be more effective than monotherapy. A single treatment with DTIC inhibited cell growth but did not induce apoptosis. Rather than reducing Nodal expression, DTIC increased the size of the Nodal-positive subpopulation, an observation coincident with increased cellular invasion. Importantly, clinical tissue specimens from patients with melanomas refractory to DTIC therapy stained positive for Nodal expression, both in pre- and post-DTIC tumors, underscoring the value of targeting Nodal. In vitro, anti-Nodal antibodies alone had some adverse effects on proliferation and apoptosis, but combining DTIC treatment with anti-Nodal antibodies decreased cell growth and increased apoptosis synergistically, at concentrations incapable of producing meaningful effects as monotherapy. Targeting Nodal in combination with DTIC therapy holds promise for the treatment of metastatic melanoma. ©2015 American Association for Cancer Research.

Targeting Nodal in Conjunction with Dacarbazine Induces Synergistic Anti-cancer Effects in Metastatic Melanoma

PubMed Central

Hardy, Katharine M.; Strizzi, Luigi; Margaryan, Naira V.; Gupta, Kanika; Murphy, George F.; Scolyer, Richard A.; Hendrix, Mary J.C.

2015-01-01

Metastatic melanoma is a highly aggressive skin cancer with a poor prognosis. Despite a complete response in fewer than 5% of patients, the chemotherapeutic agent Dacarbazine (DTIC) remains the reference drug after almost 40 years. More recently FDA approved drugs have shown promise but patient outcome remains modest, predominantly due to drug resistance. As such, combinatorial targeting has received increased attention, and will advance with the identification of new molecular targets. One attractive target for improving melanoma therapy is the growth factor Nodal, whose normal expression is largely restricted to embryonic development, but is reactivated in metastatic melanoma. In this study, we sought to determine how Nodal-positive human melanoma cells respond to DTIC treatment and to ascertain if targeting Nodal in combination with DTIC would be more effective than monotherapy. A single treatment with DTIC inhibited cell growth but did not induce apoptosis. Rather than reducing Nodal expression, DTIC increased the size of the Nodal-positive subpopulation, an observation coincident with increased cellular invasion. Importantly, clinical tissue specimens from patients with melanomas refractory to DTIC therapy stained positive for Nodal expression, both in pre- and post-DTIC tumors, underscoring the value of targeting Nodal. In vitro, anti-Nodal antibodies alone had some adverse effects on proliferation and apoptosis, but combining DTIC treatment with anti-Nodal antibodies decreased cell growth and increased apoptosis synergistically, at concentrations incapable of producing meaningful effects as monotherapy. Implications Targeting Nodal in combination with DTIC therapy holds promise for the treatment of metastatic melanoma. PMID:25767211

Nodal weighting factor method for ex-core fast neutron fluence evaluation

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

Chiang, R. T.

The nodal weighting factor method is developed for evaluating ex-core fast neutron flux in a nuclear reactor by utilizing adjoint neutron flux, a fictitious unit detector cross section for neutron energy above 1 or 0.1 MeV, the unit fission source, and relative assembly nodal powers. The method determines each nodal weighting factor for ex-core neutron fast flux evaluation by solving the steady-state adjoint neutron transport equation with a fictitious unit detector cross section for neutron energy above 1 or 0.1 MeV as the adjoint source, by integrating the unit fission source with a typical fission spectrum to the solved adjointmore » flux over all energies, all angles and given nodal volume, and by dividing it with the sum of all nodal weighting factors, which is a normalization factor. Then, the fast neutron flux can be obtained by summing the various relative nodal powers times the corresponding nodal weighting factors of the adjacent significantly contributed peripheral assembly nodes and times a proper fast neutron attenuation coefficient over an operating period. A generic set of nodal weighting factors can be used to evaluate neutron fluence at the same location for similar core design and fuel cycles, but the set of nodal weighting factors needs to be re-calibrated for a transition-fuel-cycle. This newly developed nodal weighting factor method should be a useful and simplified tool for evaluating fast neutron fluence at selected locations of interest in ex-core components of contemporary nuclear power reactors. (authors)« less

47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Digital Electronic Message Service Nodal... AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.503 Digital Electronic Message Service Nodal Stations. 10.6 GHz DEMS Nodal Stations may be...

A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality

NASA Astrophysics Data System (ADS)

Noël, Emily S.; Verhoeven, Manon; Lagendijk, Anne Karine; Tessadori, Federico; Smith, Kelly; Choorapoikayil, Suma; den Hertog, Jeroen; Bakkers, Jeroen

2013-11-01

Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind regulation of organ laterality. Here we identify a Nodal-independent mechanism that drives asymmetric heart looping in zebrafish embryos. In a unique mutant defective for the Nodal-related southpaw gene, preferential dextral looping in the heart is maintained, whereas gut and brain asymmetries are randomized. As genetic and pharmacological inhibition of Nodal signalling does not abolish heart asymmetry, a yet undiscovered mechanism controls heart chirality. This mechanism is tissue intrinsic, as explanted hearts maintain ex vivo retain chiral looping behaviour and require actin polymerization and myosin II activity. We find that Nodal signalling regulates actin gene expression, supporting a model in which Nodal signalling amplifies this tissue-intrinsic mechanism of heart looping.

Persistence of RSV promotes proliferation and epithelial-mesenchymal transition of bronchial epithelial cells through Nodal signaling.

PubMed

Xiang, Zhao; Liang, Zhang; Yanfeng, Huang; Leitao, Kang

2017-10-01

Nodal may play an important role in the development of cancers. The present study was designed to determine the effects of Nodal induced by respiratory syncytial virus (RSV) infection on the occurrence and development of lung cancer and the underlying mechanisms. After verification of RSV infection by observation of cytopathic effect and indirect immunofluorescence, real-time PCR, Western blot and methylation assays were used to verify the influence of RSV on Nodal expression. Then, a Nodal overexpressed vector was constructed and the effects of Nodal on the proliferation and apoptosis of bronchial epithelial cells (BECs) and epithelial-mesenchymal transition (EMT) were assayed by flow cytometry and Western blot, respectively. Moreover, Lefty and pSmad2/3 were assayed by Western blot and Cyclin D1, CDK4, c-myc and Bcl-2 induced by Nodal overepression or RSV infection were also assayed by real-time PCR. The results showed that Nodal over expression and demethylation of the promoter were observed in BECs after RSV infection. Activation of Nodal promoted proliferation, colony formation and EMT and inhibited apoptosis of BECs. Nodal also promoted malignant change by promoting expression of cyclin D1 and related-dependent kinase and inhibiting apoptosis. Besides, RSV infection inhibited Lefty expression and promoted the activation of pSmad2/3. RSV also promoted Cyclin D1, CDK4, c-myc and Bcl-2 expression through the activation of pSmad2/3. Our data showed that persistence of RSV promoted the proliferation, epithelial-mesenchymal transition and expression of oncogenes through Nodal signaling, which may be associated with the occurrence and development of lung cancers.

TGFβ signaling in establishing left-right asymmetry.

PubMed

Shiratori, Hidetaka; Hamada, Hiroshi

2014-08-01

Two TGFβ-related proteins, Nodal and Lefty, are asymmetrically expressed and play central roles in establishing left-right (L-R) asymmetry of our body. Nodal acts as a left-side determinant whereas Lefty restricts Nodal activity to the left side by acting as a feedback inhibitor of Nodal. While the mechanism for symmetry breaking is variable among animals, the pair of Nodal and Lefty has a conserved role in the L-R asymmetry pathway. Function and regulation of Nodal and Lefty have been revealed in the last decades, but in this review we summarize the role of TGFβ-related proteins together with more recent findings. We mainly discuss observations made with mouse embryos, unless indicated otherwise. Copyright © 2014. Published by Elsevier Ltd.

Machine learning classifier using abnormal brain network topological metrics in major depressive disorder.

PubMed

Guo, Hao; Cao, Xiaohua; Liu, Zhifen; Li, Haifang; Chen, Junjie; Zhang, Kerang

2012-12-05

Resting state functional brain networks have been widely studied in brain disease research. However, it is currently unclear whether abnormal resting state functional brain network metrics can be used with machine learning for the classification of brain diseases. Resting state functional brain networks were constructed for 28 healthy controls and 38 major depressive disorder patients by thresholding partial correlation matrices of 90 regions. Three nodal metrics were calculated using graph theory-based approaches. Nonparametric permutation tests were then used for group comparisons of topological metrics, which were used as classified features in six different algorithms. We used statistical significance as the threshold for selecting features and measured the accuracies of six classifiers with different number of features. A sensitivity analysis method was used to evaluate the importance of different features. The result indicated that some of the regions exhibited significantly abnormal nodal centralities, including the limbic system, basal ganglia, medial temporal, and prefrontal regions. Support vector machine with radial basis kernel function algorithm and neural network algorithm exhibited the highest average accuracy (79.27 and 78.22%, respectively) with 28 features (P<0.05). Correlation analysis between feature importance and the statistical significance of metrics was investigated, and the results revealed a strong positive correlation between them. Overall, the current study demonstrated that major depressive disorder is associated with abnormal functional brain network topological metrics and statistically significant nodal metrics can be successfully used for feature selection in classification algorithms.

BCS superconductors: The out-of-equilibrium response to a laser pulse

NASA Astrophysics Data System (ADS)

Avella, Adolfo

2018-05-01

The dynamics of a 2D d-wave BCS superconductor driven out-of-equilibrium by a perpendicularly-impinging polarized laser pulse is analyzed on varying the laser pulse characteristics. The observed effects include: oscillations both in the amplitude and in the phase of the superconducting order parameter, suppression of the superconductivity, but also its enhancement with a strong dependence on all varying parameters and, in particular, on the polarization in plane of the applied vector potential and on the value of its frequency. This study opens up the possibility to distinguish very clearly the behavior of the nodal and anti-nodal non-thermal excitations and to tackle some of the puzzling results of the current experimental scenario in the field.

Cerberus-Nodal-Lefty-Pitx signaling cascade controls left-right asymmetry in amphioxus.

PubMed

Li, Guang; Liu, Xian; Xing, Chaofan; Zhang, Huayang; Shimeld, Sebastian M; Wang, Yiquan

2017-04-04

Many bilaterally symmetrical animals develop genetically programmed left-right asymmetries. In vertebrates, this process is under the control of Nodal signaling, which is restricted to the left side by Nodal antagonists Cerberus and Lefty. Amphioxus, the earliest diverging chordate lineage, has profound left-right asymmetry as a larva. We show that Cerberus , Nodal , Lefty , and their target transcription factor Pitx are sequentially activated in amphioxus embryos. We then address their function by transcription activator-like effector nucleases (TALEN)-based knockout and heat-shock promoter (HSP)-driven overexpression. Knockout of Cerberus leads to ectopic right-sided expression of Nodal , Lefty , and Pitx , whereas overexpression of Cerberus represses their left-sided expression. Overexpression of Nodal in turn represses Cerberus and activates Lefty and Pitx ectopically on the right side. We also show Lefty represses Nodal , whereas Pitx activates Nodal These data combine in a model in which Cerberus determines whether the left-sided gene expression cassette is activated or repressed. These regulatory steps are essential for normal left-right asymmetry to develop, as when they are disrupted embryos may instead form two phenotypic left sides or two phenotypic right sides. Our study shows the regulatory cassette controlling left-right asymmetry was in place in the ancestor of amphioxus and vertebrates. This includes the Nodal inhibitors Cerberus and Lefty, both of which operate in feedback loops with Nodal and combine to establish asymmetric Pitx expression. Cerberus and Lefty are missing from most invertebrate lineages, marking this mechanism as an innovation in the lineage leading to modern chordates.

Type-I and type-II topological nodal superconductors with s -wave interaction

NASA Astrophysics Data System (ADS)

Huang, Beibing; Yang, Xiaosen; Xu, Ning; Gong, Ming

2018-01-01

Topological nodal superconductors with protected gapless points in momentum space are generally realized based on unconventional pairings. In this work we propose a minimal model to realize these topological nodal phases with only s -wave interaction. In our model the linear and quadratic spin-orbit couplings along the two orthogonal directions introduce anisotropic effective unconventional pairings in momentum space. This model may support different nodal superconducting phases characterized by either an integer winding number in BDI class or a Z2 index in D class at the particle-hole invariant axes. In the vicinity of the nodal points the effective Hamiltonian can be described by either type-I or type-II Dirac equations, and the Lifshitz transition from type-I nodal phases to type-II nodal phases can be driven by external in-plane magnetic fields. We show that these nodal phases are robust against weak impurities, which only slightly renormalizes the momentum-independent parameters in the impurity-averaged Hamiltonian, thus these phases are possible to be realized in experiments with real semi-Dirac materials. The smoking-gun evidences to verify these phases based on scanning tunneling spectroscopy method are also briefly discussed.

Nodal signalling and asymmetry of the nervous system

PubMed Central

Signore, Iskra A.; Palma, Karina

2016-01-01

The role of Nodal signalling in nervous system asymmetry is still poorly understood. Here, we review and discuss how asymmetric Nodal signalling controls the ontogeny of nervous system asymmetry using a comparative developmental perspective. A detailed analysis of asymmetry in ascidians and fishes reveals a critical context-dependency of Nodal function and emphasizes that bilaterally paired and midline-unpaired structures/organs behave as different entities. We propose a conceptual framework to dissect the developmental function of Nodal as asymmetry inducer and laterality modulator in the nervous system, which can be used to study other types of body and visceral organ asymmetries. Using insights from developmental biology, we also present novel evolutionary hypotheses on how Nodal led the evolution of directional asymmetry in the brain, with a particular focus on the epithalamus. We intend this paper to provide a synthesis on how Nodal signalling controls left–right asymmetry of the nervous system. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’. PMID:27821531

Hopf-link topological nodal-loop semimetals

NASA Astrophysics Data System (ADS)

Zhou, Yao; Xiong, Feng; Wan, Xiangang; An, Jin

2018-04-01

We construct a generic two-band model which can describe topological semimetals with multiple closed nodal loops. All the existing multi-nodal-loop semimetals, including the nodal-net, nodal-chain, and Hopf-link states, can be examined within the same framework. Based on a two-nodal-loop model, the corresponding drumhead surface states for these topologically different bulk states are studied and compared with each other. The connection of our model with Hopf insulators is also discussed. Furthermore, to identify experimentally these topologically different semimetal states, especially to distinguish the Hopf-link from unlinked ones, we also investigate their Landau levels. It is found that the Hopf-link state can be characterized by the existence of a quadruply degenerate zero-energy Landau band, regardless of the direction of the magnetic field.

Left-right asymmetry in the level of active Nodal protein produced in the node is translated into left-right asymmetry in the lateral plate of mouse embryos.

PubMed

Kawasumi, Aiko; Nakamura, Tetsuya; Iwai, Naomi; Yashiro, Kenta; Saijoh, Yukio; Belo, Jose Antonio; Shiratori, Hidetaka; Hamada, Hiroshi

2011-05-15

Left-right (L-R) asymmetry in the mouse embryo is generated in the node and is dependent on cilia-driven fluid flow, but how the initial asymmetry is transmitted from the node to the lateral plate has remained unknown. We have now identified a transcriptional enhancer (ANE) in the human LEFTY1 gene that exhibits marked L>R asymmetric activity in perinodal cells of the mouse embryo. Dissection of ANE revealed that it is activated in the perinodal cells on the left side by Nodal signaling, suggesting that Nodal activity in the node is asymmetric at a time when Nodal expression is symmetric. Phosphorylated Smad2/3 (pSmad2) indeed manifested an L-R asymmetric distribution at the node, being detected in perinodal cells preferentially on the left side. This asymmetry in pSmad2 distribution was found to be generated not by unidirectional transport of Nodal but rather as a result of LR distribution of active Nodal in the node is translated into the asymmetry in LPM. Copyright © 2011 Elsevier Inc. All rights reserved.

Occult Nodal Disease Prevalence and Distribution in Recurrent Laryngeal Cancer Requiring Salvage Laryngectomy.

PubMed

Birkeland, Andrew C; Rosko, Andrew J; Issa, Mohamad R; Shuman, Andrew G; Prince, Mark E; Wolf, Gregory T; Bradford, Carol R; McHugh, Jonathan B; Brenner, J Chad; Spector, Matthew E

2016-03-01

The indications for neck dissection concurrent with salvage laryngectomy in the clinically N0 setting remain unclear. Our goals were to determine the prevalence of occult nodal disease, analyze nodal disease distribution patterns, and identify predictors of occult nodal disease in a salvage laryngectomy cohort. Case series with planned data collection. Tertiary academic center. Patients with persistent or recurrent laryngeal squamous cell carcinoma (LSCC) after radiation/chemoradiation failure undergoing salvage laryngectomy with neck dissection. We analyzed a single-institution retrospective case series of patients between 1997 and 2014 and identified those who had clinically N0 (cN0) necks (n = 203). Clinical and pathologic data, including nodal prevalence and distribution, were collected and statistical analyses performed. Overall, cN0 necks had histologically positive occult nodes in 17% (n = 35) of cases. Univariate predictors of occult nodal positivity included recurrent T4 stage (34% T4 vs 12% non-T4; P = .0003) and supraglottic subsite (28% supraglottic vs 10% nonsupraglottic; P = .0006). Histologically positive nodes associated with supraglottic primaries were most frequently positive in ipsilateral levels II and III (17% and 16%). Positive nodes for glottic LSCC were most frequently positive in the ipsilateral and contralateral paratracheal nodes (11% and 9%). Histologically positive occult nodes are identified in 17% of cN0 patients undergoing salvage laryngectomy with neck dissection. Occult nodal disease varies in frequency and distribution based on tumor subsite. Predictors of high (>20%) occult nodal positivity include T4 tumors and supraglottic subsite. In glottic LSCC, the most frequent sites of occult nodal disease are the paratracheal nodal basins. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Role of Ultrasonography of Regional Nodal Basins in Staging Triple-Negative Breast Cancer and Implications For Local-Regional Treatment

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

Shaitelman, Simona F., E-mail: sfshaitelman@mdanderson.org; Tereffe, Welela; Dogan, Basak E.

2015-09-01

Purpose: We sought to determine the rate at which regional nodal ultrasonography would increase the nodal disease stage in patients with triple-negative breast cancer (TNBC) beyond the clinical stage determined by physical examination and mammography alone, and significantly affect the treatments delivered to these patients. Methods and Materials: We retrospectively reviewed the charts of women with stages I to III TNBC who underwent physical examination, mammography, breast and regional nodal ultrasonography with needle biopsy of abnormal nodes, and definitive local-regional treatment at our institution between 2004 and 2011. The stages of these patients' disease with and without ultrasonography of the regionalmore » nodal basins were compared using the Pearson χ{sup 2} test. Definitive treatments of patients whose nodal disease was upstaged on the basis of ultrasonographic findings were compared to those of patients whose disease stage remained the same. Results: A total of 572 women met the study requirements. In 111 (19.4%) of these patients, regional nodal ultrasonography with needle biopsy resulted in an increase in disease stage from the original stage by physical examination and mammography alone. Significantly higher percentages of patients whose nodal disease was upstaged by ultrasonographic findings compared to that in patients whose disease was not upstaged underwent neoadjuvant systemic therapy (91.9% and 51.2%, respectively; P<.0001), axillary lymph node dissection (99.1% and 34.5%, respectively; P<.0001), and radiation to the regional nodal basins (88.2% and 29.1%, respectively; P<.0001). Conclusions: Regional nodal ultrasonography in TNBC frequently changes the initial clinical stage and plays an important role in treatment planning.« less

Evaluating Mesorectal Lymph Nodes in Rectal Cancer Before and After Neoadjuvant Chemoradiation Using Thin-Section T2-Weighted Magnetic Resonance Imaging

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

Koh, Dow-Mu; Chau, Ian; Tait, Diana

2008-06-01

Purpose: To apply thin-section T2-weighted magnetic resoance imaging (MRI) to evaluate the number, size, distribution, and morphology of benign and malignant mesorectal lymph nodes before and after chemoradiation treatment compared with histopathologic findings. Methods and Materials: Twenty-five patients with poor-risk adenocarcinoma of the rectum treated with neoadjuvant chemoradiation were evaluated prospectively. Thin-section T2-weighted MR images obtained before and after chemoradiation treatment were independently reviewed in consensus by 2 expert radiologists to determine the tumor stage, nodal size, nodal distribution, and nodal stage. Total mesorectal excision surgery after chemoradiation allowed MR nodal stage to be compared with histopathology using {kappa} statistics.more » Nodal downstaging was compared using the Chi-square test. Results: Before chemoradiation, 152 mesorectal nodes were visible (mean, 6.2 mm; 100 benign, 52 malignant) and 4 of 52 malignant nodes were in contact with the mesorectal fascia. The nodal staging was 7/25 N0, 10/25 N1, and 7/25 N2. After chemoradiation, only 29 nodes (mean, 4.1 mm; 24 benign, 5 malignant) were visible, and none were in contact with the mesorectal fascia. Nodal downstaging was observed: 20/25 N0 and 5/25 N1 (p < 0.01, Chi-square test). There was good agreement between MRI and pathologic T-staging ({kappa} = 0.64) and N-staging ({kappa} = 0.65) after chemoradiation. Conclusions: Neoadjuvant chemoradiation treatment resulted in a decrease in size and number of malignant- and benign-appearing mesorectal nodes on MRI. Nodal downstaging and nodal regression from the mesorectal fascia were observed after treatment. MRI is a useful tool for assessing nodal response to neoadjuvant treatment.« less

Long-term results of positron emission tomography-directed management of the neck in node-positive head and neck cancer after organ preservation therapy.

PubMed

Sjövall, Johanna; Chua, Benjamin; Pryor, David; Burmeister, Elizabeth; Foote, Matthew C; Panizza, Benedict; Burmeister, Bryan H; Porceddu, Sandro V

2015-03-01

The current study presents the long-term results from a study designed to evaluate a restaging positron emission tomography (PET) directed policy whereby neck dissections were omitted in all node positive head and neck squamous cell carcinoma (N+HNSCC) patients with PET-negative lymph nodes after definitive radiotherapy (RT), with or without chemotherapy. A post-therapy nodal response assessment with PET and computed tomography (CT) was performed in patients who achieved a complete response at the primary site after definitive radiotherapy. Patients with PET-negative lymph nodes were observed regardless of residual CT abnormalities. One hundred and twelve patients, the majority of whom (83 patients, 74%) had oropharyngeal primaries, were treated on protocol. Median follow-up was 62months. Negative and positive predictive values for the restaging PET was 97.1% and 77.8% respectively, with only one patient who was PET-negative after treatment experiencing an isolated nodal relapse. PET-guided management of the neck following organ preservation therapy effectively spares neck dissections in patients with N+HNSCC without compromising isolated nodal control or overall survival. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

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

Wintermeyer, Niklas; Winters, Andrew R., E-mail: awinters@math.uni-koeln.de; Gassner, Gregor J.

We design an arbitrary high-order accurate nodal discontinuous Galerkin spectral element approximation for the non-linear two dimensional shallow water equations with non-constant, possibly discontinuous, bathymetry on unstructured, possibly curved, quadrilateral meshes. The scheme is derived from an equivalent flux differencing formulation of the split form of the equations. We prove that this discretization exactly preserves the local mass and momentum. Furthermore, combined with a special numerical interface flux function, the method exactly preserves the mathematical entropy, which is the total energy for the shallow water equations. By adding a specific form of interface dissipation to the baseline entropy conserving schememore » we create a provably entropy stable scheme. That is, the numerical scheme discretely satisfies the second law of thermodynamics. Finally, with a particular discretization of the bathymetry source term we prove that the numerical approximation is well-balanced. We provide numerical examples that verify the theoretical findings and furthermore provide an application of the scheme for a partial break of a curved dam test problem.« less

A contemporary view of atrioventricular nodal physiology.

PubMed

Markowitz, Steven M; Lerman, Bruce B

2018-06-16

In delaying transmission of the cardiac impulse from the atria to the ventricles, the atrioventricular (AV) node serves a critical function in augmenting ventricular filling during diastole and limiting the ventricular response during atrial tachyarrhythmias. The complex structure of the nodal region, however, also provides the substrate for reentrant rhythms. Recent discoveries have elucidated the cellular basis and anatomical determinants of slow conduction in the node. Based on analysis of gap junction proteins, distinct structural components of the AV node have been defined, including the compact node, right and left inferior nodal extensions, the lower nodal bundle, and transitional tissue. Emerging evidence supports the role of the inferior nodal extensions in mediating slow pathway conduction. The most common form of reentry involving the node, slow-fast AV nodal reentrant tachycardia (AVNRT), utilizes the inferior nodal extensions for anterograde slow pathway conduction; the structures responsible for retrograde fast pathway activation in the superior septum are less well defined and likely heterogeneous. Atypical forms of AVNRT arise from circuits that activate at least one of the inferior extensions in the retrograde direction.

Role of the EGF-Related Growth Factor cripto in Murine Mammary Tumorigenesis

DTIC Science & Technology

2000-10-01

necessary for emergency repair or overhaul or (ii) is a release or disclosure of technical data (other than detailed manufacturing or process data) to, or...constructs that express secreted processed NODAL protein in transfected mammalian cells. We found that processing of unmodified NODAL protein is...NODAL processing (Constam and Robertson, 1999). As shown in our 1999 report, cleaved mature Nodal protein can be produced in the culture supernatants

Nodal portraits of quantum billiards: Domains, lines, and statistics

NASA Astrophysics Data System (ADS)

Jain, Sudhir Ranjan; Samajdar, Rhine

2017-10-01

This is a comprehensive review of the nodal domains and lines of quantum billiards, emphasizing a quantitative comparison of theoretical findings to experiments. The nodal statistics are shown to distinguish not only between regular and chaotic classical dynamics but also between different geometric shapes of the billiard system itself. How a random superposition of plane waves can model chaotic eigenfunctions is discussed and the connections of the complex morphology of the nodal lines thereof to percolation theory and Schramm-Loewner evolution are highlighted. Various approaches to counting the nodal domains—using trace formulas, graph theory, and difference equations—are also illustrated with examples. The nodal patterns addressed pertain to waves on vibrating plates and membranes, acoustic and electromagnetic modes, wave functions of a "particle in a box" as well as to percolating clusters, and domains in ferromagnets, thus underlining the diversity and far-reaching implications of the problem.

Structural insights into the interaction of a monoclonal antibody and Nodal peptides by STD-NMR spectroscopy.

PubMed

Calvanese, Luisa; Focà, Annalia; Sandomenico, Annamaria; Focà, Giuseppina; Caporale, Andrea; Doti, Nunzianna; Iaccarino, Emanuela; Leonardi, Antonio; D'Auria, Gabriella; Ruvo, Menotti; Falcigno, Lucia

2017-12-15

Nodal is a growth factor expressed during early embryonic development, but reactivated in several advanced-stage cancers. Targeting of Nodal signaling, which occurs via the binding to Cripto-1 co-receptor, results in inhibition of cell aggressiveness and reduced tumor growth. The Nodal binding region to Cripto-1 was identified and targeted with a high affinity monoclonal antibody (3D1). By STD-NMR technique, we investigated the interaction of Nodal fragments with 3D1 with the aim to elucidate at atomic level the interaction surface. Data indicate with high accuracy the antibody-antigen contact atoms and confirm the information previously obtained by immune-enzymatic methods. Main residues contacted by 3D1 are P46, V47, E49 and E50, which belong to the Nodal loop involved in the interaction with the co-receptor. Copyright © 2017 Elsevier Ltd. All rights reserved.

Topological Nodal-Net Semimetal in a Graphene Network Structure

NASA Astrophysics Data System (ADS)

Wang, Jian-Tao; Nie, Simin; Weng, Hongming; Kawazoe, Yoshiyuki; Chen, Changfeng

2018-01-01

Topological semimetals are characterized by the nodal points in their electronic structure near the Fermi level, either discrete or forming a continuous line or ring, which are responsible for exotic properties related to the topology of bulk bands. Here we identify by ab initio calculations a distinct topological semimetal that exhibits nodal nets comprising multiple interconnected nodal lines in bulk and have two coupled drumheadlike flat bands around the Fermi level on its surface. This nodal net semimetal state is proposed to be realized in a graphene network structure that can be constructed by inserting a benzene ring into each C- C bond in the bct-C4 lattice or by a crystalline modification of the (5,5) carbon nanotube. These results expand the realm of nodal manifolds in topological semimetals, offering a new platform for exploring novel physics in these fascinating materials.

Face Centered Cubic SnSe as a Z2 Trivial Dirac Nodal Line Material

NASA Astrophysics Data System (ADS)

Tateishi, Ikuma; Matsuura, Hiroyasu

2018-07-01

The presence of a Dirac nodal line in a time-reversal and inversion symmetric system is dictated by the Z2 index when spin-orbit interaction is absent. In a first principles calculation, we show that a Dirac nodal line can emerge in Z2 trivial material by calculating the band structure of SnSe in a face centered cubic lattice as an example. We qualitatively show that it becomes a topological crystalline insulator when spin-orbit interaction is taken into account. We clarify the origin of the Dirac nodal line by obtaining irreducible representations corresponding to bands and explain the triviality of the Z2 index. We construct an effective model representing the Dirac nodal line using the k · p method, and discuss the Berry phase and a surface state expected from the Dirac nodal line.

Potential clinical value of PET/CT in predicting occult nodal metastasis in T1-T2N0M0 lung cancer patients staged by PET/CT

PubMed Central

Zhou, Xiang; Chen, Ruohua; Huang, Gang; Liu, Jianjun

2017-01-01

We assessed the clinical value of 2-fluoro-2-deoxyglucose (18F-FDG) PET/CT imaging for predicting occult nodal metastasis in non-small cell lung cancer (NSCLC) patients. This retrospective study included 54 patients with T1-2N0M0 NSCLC who had undergone 18F-FDG PET/CT before surgery. Occult nodal metastasis was detected in 25.9% (14/54) of the patients. Immunohistochemical analysis revealed that increased glucose transporter 1 expression was associated with occult nodal metastasis, but hexokinase 2 expression was not. Compared to the negative nodal metastasis group, the positive nodal metastasis group was associated with increased maximum standardized uptake value (SUVmax) and tumor size. Multivariate analysis indicated that SUVmax and tumor size were associated with nodal metastasis. Nodal metastasis could be predicted with a sensitivity of 92.9% and a specificity of 55.0% when the SUVmax cutoff was 4.35. When patients were divided into low-risk (tumor size ≤ 2.5 cm and SUVmax ≤ 4.35), moderate-risk (tumor size ≤ 2.5 cm and SUVmax > 4.35 or tumor size > 2.5 cm and SUVmax ≤ 4.35) and high-risk (tumor size > 2.5 cm and SUVmax > 4.35) groups, the lymph node metastasis rates were 4.3%, 22.7%, and 88.9%, respectively. These results indicate that the combination of SUVmax and tumor size has potential clinical value for predicting occult nodal metastasis in NSCLC patients. PMID:29137276

Mechanism for generation of left isomerism in Ccdc40 mutant embryos

PubMed Central

Sugrue, Kelsey F.

2017-01-01

Leftward fluid flow in the mouse node is generated by cilia and is critical for initiating asymmetry of the left-right axis. Coiled-coil domain containing-40 (Ccdc40) plays an evolutionarily conserved role in the assembly of motile cilia and establishment of the left-right axis. Approximately one-third of Ccdc40lnks mutant embryos display situs defects and here we investigate the underlying mechanism. Ccdc40lnks mutants show delayed induction of markers of the left-lateral plate mesoderm (L-LPM) including Lefty1, Lefty2 and Nodal. Consistent with defective cilia motility compromising fluid flow across the node, initiation of asymmetric perinodal Cerberus like-2 (Cerl2) expression is delayed and then randomized. This is followed by delayed and then randomized asymmetric Nodal expression around the node. We propose a model to explain how left isomerism arises in a proportion of Ccdc40lnks mutants. We postulate that with defective motile cilia, Cerl2 expression remains symmetric and Nodal is antagonized equally on both sides of the node. This effectively reduces Nodal activation bilaterally, leading to reduced and delayed activation of Nodal and its antagonists in the LPM. This model is further supported by the failure to establish Nodal expression in the left-LPM with reduced Nodal gene dosage in Ccdc40lnks/lnks;NodalLacZ/+ mutants causing a predominance of right not left isomerism. Together these results suggest a model where cilia generated fluid flow in the node functions to ensure robust Nodal activation and a timely left-sided developmental program in the LPM. PMID:28182636

Meshfree Modeling of Munitions Penetration in Soils

DTIC Science & Technology

2017-04-01

discretization ...................... 8 Figure 2. Nodal smoothing domain for the modified stabilized nonconforming nodal integration...projectile ............................................................................................... 36 Figure 17. Discretization for the...List of Acronyms DEM: discrete element methods FEM: finite element methods MSNNI: modified stabilized nonconforming nodal integration RK

Evaluation of the use of nodal methods for MTR neutronic analysis

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

Reitsma, F.; Mueller, E.Z.

1997-08-01

Although modern nodal methods are used extensively in the nuclear power industry, their use for research reactor analysis has been very limited. The suitability of nodal methods for material testing reactor analysis is investigated with the emphasis on the modelling of the core region (fuel assemblies). The nodal approach`s performance is compared with that of the traditional finite-difference fine mesh approach. The advantages of using nodal methods coupled with integrated cross section generation systems are highlighted, especially with respect to data preparation, simplicity of use and the possibility of performing a great variety of reactor calculations subject to strict timemore » limitations such as are required for the RERTR program.« less

On the Viability of Using Autonomous Three-Component Nodal Geophones to Calculate Teleseismic Ps Receiver Functions with an Application to the Old Faithful Hydrothermal System and the Cascadia Subduction Zone

NASA Astrophysics Data System (ADS)

Ward, K. M.; Lin, F. C.

2017-12-01

Recent advances in seismic data-acquisition technology paired with an increasing interest from the academic passive source seismological community have opened up new scientific targets and imaging possibilities, often referred to as Large-N experiments (large number of instruments). The success of these and other deployments has motivated individual researchers, as well as the larger seismological community, to invest in the next generation of nodal geophones. Although the new instruments have battery life and bandwidth limitations compared to broadband instruments, the relatively low deployment and procurement cost of these new nodal geophones provides an additional novel tool for researchers. Here, we explore the viability of using autonomous three-component nodal geophones to calculate teleseismic Ps receiver functions by comparison of co-located broadband stations and highlight some potential advantages with a dense nodal array deployed around the Upper Geyser basin in Yellowstone National Park. Two key findings from this example include (1) very dense nodal arrays can be used to image small-scale features in the shallow crust that typical broadband station spacing would alias, and (2) nodal arrays with a larger footprint could be used to image deeper features with greater or equal detail as typical broadband deployments but at a reduced deployment cost. The success of the previous example has motivated a larger 2-D line across the Cascadia subduction zone. In the summer of 2017, we deployed 174 nodal geophones with an average site spacing of 750 m. Synthetic tests with dense station spacing ( 1 km) reveal subtler features of the system that is consistent with our preliminary receiver function results from our Cascadia deployment. With the increasing availability of nodal geophones to individual researchers and the successful demonstration that nodal geophones are a viable instrument for receiver function studies, numerous scientific targets can be investigated at reduced costs or in expanded detail.

The Effect of Anatomical Location of Lymph Node Metastases on Cancer Specific Survival in Patients with Clear Cell Renal Cell Carcinoma.

PubMed

Nini, Alessandro; Larcher, Alessandro; Cianflone, Francesco; Trevisani, Francesco; Terrone, Carlo; Volpe, Alessandro; Regis, Federica; Briganti, Alberto; Salonia, Andrea; Montorsi, Francesco; Bertini, Roberto; Capitanio, Umberto

2018-01-01

Positive nodal status (pN1) is an independent predictor of survival in renal cell carcinoma (RCC) patients. However, no study to date has tested whether the location of lymph node (LN) metastases does affect oncologic outcomes in a population submitted to radical nephrectomy (RN) and extended lymph node dissection (eLND). To describe nodal disease dissemination in clear cell RCC (ccRCC) patients and to assess the effect of the anatomical sites and the number of nodal areas affected on cancer specific mortality (CSM). The study included 415 patients who underwent RN and eLND, defined as the removal of hilar, side-specific (pre/paraaortic or pre/paracaval) and interaortocaval LNs for ccRCC, at two institutions. Descriptive statistics were used to depict nodal dissemination in pN1 patients, stratified according to nodal site and number of involved areas. Multivariable Cox regression analyses and Kaplan-Meier curves were used to explore the relationship between pN1 disease features and survival outcomes. Median number of removed LN was 14 (IQR 9-19); 23% of patients were pN1. Among patients with one involved nodal site, 54 and 26% of patients were positive only in side-specific and interaortocaval station, respectively. The most frequent nodal site was the interaortocaval and side-specific one, for right and left ccRCC, respectively. Interaortocaval nodal positivity (HR 2.3, CI 95%: 1.3-3.9, p < 0.01) represented an independent predictor of CSM. When ccRCC patient harbour nodal disease, its spreading can occur at any nodal station without involving the others. The presence of interoartocaval positive nodes does affect oncologic outcomes. Lymph node invasion in patients with clear cell renal cell carcinoma is not following a fixed anatomical pattern. An extended lymph node dissection, during treatment for primary kidney tumour, would aid patient risk stratification and multimodality upfront treatment.

Clinical Usefulness of [(18)F]Fluoro-2-Deoxy-D-Glucose Uptake in 178 Head-and-Neck Cancer Patients With Nodal Metastasis Treated With Definitive Chemoradiotherapy: Consideration of Its Prognostic Value and Ability to Provide Guidance for Optimal Selection of Patients for Planned Neck Dissection

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

Inokuchi, Haruo, E-mail: h.inokuchi@scchr.j; Kodaira, Takeshi; Tachibana, Hiroyuki

2011-03-01

Purpose: To evaluate the clinical effectiveness of pretreatment [(18)F]fluoro-2-deoxy-D-glucose-positron emission tomography for head-and-neck squamous cell carcinoma patients with nodal metastasis treated with chemoradiotherapy. Methods and Materials: Between March 2002 and December 2006, 178 patients with head-and-neck squamous cell carcinoma and nodal metastasis underwent fluoro-2-deoxy-D-glucose positron emission tomography before chemoradiotherapy. Fluoro-2-deoxy-D-glucose uptake by both the primary lesion and the neck node was measured using the standard uptake value (SUV). The overall survival, disease-free survival, local control, nodal progression-free survival, and distant metastasis-free survival rates were calculated, and several prognostic factors were evaluated. Results: The patients with a nodal SUV {>=}6.00 hadmore » a significantly lower 3-year disease-free survival rate than those with a lower SUV (44% vs. 69%, p = .004). On multivariate analysis, a high SUV of nodal disease also proved to be a significantly unfavorable factor for disease-free survival (p = .04, 95% confidence interval [CI], 1.02-3.23), nodal progression-free survival (p = .05; 95% CI, 1.00-4.15), and distant metastasis-free survival (p = .016; 95% CI, 1.25-8.92). Among the patients with a greater nodal SUV ({>=}6.00), those treated with planned neck dissection had better nodal progression-free survival than those in the observation group (p = .04, hazard ratio, 2.36; 95% CI, 1.00-5.85). Conclusion: Among head-and-neck squamous cell carcinoma patients treated with chemoradiotherapy, the pretreatment SUV of nodal disease was one of the strongest prognostic factors and also provided important information for the selection of patients suitable for planned neck dissection.« less

Optical conductivity of three and two dimensional topological nodal-line semimetals

NASA Astrophysics Data System (ADS)

Barati, Shahin; Abedinpour, Saeed H.

2017-10-01

The peculiar shape of the Fermi surface of topological nodal-line semimetals at low carrier concentrations results in their unusual optical and transport properties. We analytically investigate the linear optical responses of three- and two-dimensional nodal-line semimetals using the Kubo formula. The optical conductivity of a three-dimensional nodal-line semimetal is anisotropic. Along the axial direction (i.e., the direction perpendicular to the nodal-ring plane), the Drude weight has a linear dependence on the chemical potential at both low and high carrier dopings. For the radial direction (i.e., the direction parallel to the nodal-ring plane), this dependence changes from linear into quadratic in the transition from low into high carrier concentration. The interband contribution into optical conductivity is also anisotropic. In particular, at large frequencies, it saturates to a constant value for the axial direction and linearly increases with frequency along the radial direction. In two-dimensional nodal-line semimetals, no interband optical transition could be induced and the only contribution to the optical conductivity arises from the intraband excitations. The corresponding Drude weight is independent of the carrier density at low carrier concentrations and linearly increases with chemical potential at high carrier doping.

Cilia are required for asymmetric nodal induction in the sea urchin embryo.

PubMed

Tisler, Matthias; Wetzel, Franziska; Mantino, Sabrina; Kremnyov, Stanislav; Thumberger, Thomas; Schweickert, Axel; Blum, Martin; Vick, Philipp

2016-08-23

Left-right (LR) organ asymmetries are a common feature of metazoan animals. In many cases, laterality is established by a conserved asymmetric Nodal signaling cascade during embryogenesis. In most vertebrates, asymmetric nodal induction results from a cilia-driven leftward fluid flow at the left-right organizer (LRO), a ciliated epithelium present during gastrula/neurula stages. Conservation of LRO and flow beyond the vertebrates has not been reported yet. Here we study sea urchin embryos, which use nodal to establish larval LR asymmetry as well. Cilia were found in the archenteron of embryos undergoing gastrulation. Expression of foxj1 and dnah9 suggested that archenteron cilia were motile. Cilia were polarized to the posterior pole of cells, a prerequisite of directed flow. High-speed videography revealed rotating cilia in the archenteron slightly before asymmetric nodal induction. Removal of cilia through brief high salt treatments resulted in aberrant patterns of nodal expression. Our data demonstrate that cilia - like in vertebrates - are required for asymmetric nodal induction in sea urchin embryos. Based on these results we argue that the anterior archenteron represents a bona fide LRO and propose that cilia-based symmetry breakage is a synapomorphy of the deuterostomes.

Nodal Topological Phases in s-wave Superfluid of Ultracold Fermionic Gases

NASA Astrophysics Data System (ADS)

Huang, Bei-Bing; Yang, Xiao-Sen

2018-02-01

The gapless Weyl superfluid has been widely studied in the three-dimensional ultracold fermionic superfluid. In contrast to Weyl superfluid, there exists another kind of gapless superfluid with topologically protected nodal lines, which can be regarded as the superfluid counterpart of nodal line semimetal in the condensed matter physics, just as Weyl superfluid with Weyl semimetal. In this paper we study the ground states of the cold fermionic gases in cubic optical lattices with one-dimensional spin-orbit coupling and transverse Zeeman field and map out the topological phase diagram of the system. We demonstrate that in addition to a fully gapped topologically trivial phase, some different nodal line superfluid phases appear when the Zeeman field is adjusted. The presence of topologically stable nodal lines implies the dispersionless zero-energy flat band in a finite region of the surface Brillouin zone. Experimentally these nodal line superfluid states can be detected via the momentum-resolved radio-frequency spectroscopy. The nodal line topological superfluid provide fertile grounds for exploring exotic quantum matters in the context of ultracold atoms. Supported by National Natural Science Foundation of China under Grant Nos. 11547047 and 11504143

Mapping of nodal disease in locally advanced prostate cancer: Rethinking the clinical target volume for pelvic nodal irradiation based on vascular rather than bony anatomy

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

Shih, Helen A.; Harisinghani, Mukesh; Zietman, Anthony L.

2005-11-15

Purpose: Toxicity from pelvic irradiation could be reduced if fields were limited to likely areas of nodal involvement rather than using the standard 'four-field box.' We employed a novel magnetic resonance lymphangiographic technique to highlight the likely sites of occult nodal metastasis from prostate cancer. Methods and Materials: Eighteen prostate cancer patients with pathologically confirmed node-positive disease had a total of 69 pathologic nodes identifiable by lymphotropic nanoparticle-enhanced MRI and semiquantitative nodal analysis. Fourteen of these nodes were in the para-aortic region, and 55 were in the pelvis. The position of each of these malignant nodes was mapped to amore » common template based on its relation to skeletal or vascular anatomy. Results: Relative to skeletal anatomy, nodes covered a diffuse volume from the mid lumbar spine to the superior pubic ramus and along the sacrum and pelvic side walls. In contrast, the nodal metastases mapped much more tightly relative to the large pelvic vessels. A proposed pelvic clinical target volume to encompass the region at greatest risk of containing occult nodal metastases would include a 2.0-cm radial expansion volume around the distal common iliac and proximal external and internal iliac vessels that would encompass 94.5% of the pelvic nodes at risk as defined by our node-positive prostate cancer patient cohort. Conclusions: Nodal metastases from prostate cancer are largely localized along the major pelvic vasculature. Defining nodal radiation treatment portals based on vascular rather than bony anatomy may allow for a significant decrease in normal pelvic tissue irradiation and its associated toxicities.« less

Differential role of Sloan–Kettering Institute (Ski) protein in Nodal and transforming growth factor-beta (TGF-β)-induced Smad signaling in prostate cancer cells

PubMed Central

Khan, Shafiq A.

2012-01-01

Transforming growth factor-beta (TGF-β) signaling pathways contain both tumor suppressor and tumor promoting activities. We have demonstrated that Nodal, another member of the TGF-β superfamily, and its receptors are expressed in prostate cancer cells. Nodal and TGF-β exerted similar biological effects on prostate cells; both inhibited proliferation in WPE, RWPE1 and DU145 cells, whereas neither had any effect on the proliferation of LNCaP or PC3 cells. Interestingly, Nodal and TGF-β induced migration in PC3 cells, but not in DU145 cells. TGF-β induced predominantly phosphorylation of Smad3, whereas Nodal induced phosphorylation of only Smad2. We also determined the expression and differential role of Ski, a corepressor of Smad2/3, in Nodal and TGF-β signaling in prostate cancer cells. Similar levels of Ski mRNA were found in several established prostate cell lines; however, high levels of Ski protein were only detected in prostate cancer cells and prostate cancer tissue samples. Exogenous Nodal and TGF-β had no effects on Ski mRNA levels. On the other hand, TGF-β induced a rapid degradation of Ski protein mediated by the proteasomal pathway, whereas Nodal had no effect on Ski protein. Reduced Ski levels correlated with increased basal and TGF-β-induced Smad2/3 phosphorylation. Knockdown of endogenous Ski reduced proliferation in DU145 cells and enhanced migration of PC3 cells. We conclude that high levels of Ski expression in prostate cancer cells may be responsible for repression of TGF-β and Smad3 signaling, but Ski protein levels do not influence Nodal and Smad2 signaling. PMID:22843506

Long-term results of high-dose conformal radiotherapy for patients with medically inoperable T1-3N0 non-small-cell lung cancer: is low incidence of regional failure due to incidental nodal irradiation?

PubMed

Chen, Ming; Hayman, James A; Ten Haken, Randall K; Tatro, Daniel; Fernando, Shaneli; Kong, Feng-Ming

2006-01-01

To report the results of high-dose conformal irradiation and examine incidental nodal irradiation and nodal failure in patients with inoperable early-stage non-small-cell lung cancer (NSCLC). This analysis included patients with inoperable CT-staged T1-3N0M0 NSCLC treated on our prospective dose-escalation trial. Patients were treated with radiation alone (total dose, 63-102.9 Gy in 2.1-Gy daily fractions) with a three-dimensional conformal technique without intentional nodal irradiation. Bilateral highest mediastinal and upper/lower paratracheal, prevascular and retrotracheal, sub- and para-aortic, subcarinal, paraesophageal, and ipsilateral hilar regions were delineated individually. Nodal failure and doses of incidental irradiation were studied. The potential median follow-up was 104 months. For patients who completed protocol treatment, median survival was 31 months. The actuarial overall survival rate was 86%, 61%, 43%, and 21% and the cause-specific survival rate was 89%, 70%, 53%, and 35% at 1, 2, 3, and 5 years, respectively. Weight loss (p = 0.008) and radiation dose in Gy (p = 0.013) were significantly associated with overall survival. In only 22% and 13% of patients examined did ipsilateral hilar and paratracheal (and subaortic for left-sided tumor) nodal regions receive a dose of > or = 40 Gy, respectively. Less than 10% of all other nodal regions received a dose of > or = 40 Gy. No patients failed initially at nodal sites. Radiation dose is positively associated with overall survival in patients with medically inoperable T1-3N0 NSCLC, though long-term results remain poor. The nodal failure rate is low and does not seem to be due to high-dose incidental irradiation.

Quantum oscillations in nodal line systems

NASA Astrophysics Data System (ADS)

Yang, Hui; Moessner, Roderich; Lim, Lih-King

2018-04-01

We study signatures of magnetic quantum oscillations in three-dimensional nodal line semimetals at zero temperature. The extended nature of the degenerate bands can result in a Fermi surface geometry with topological genus one, as well as a Fermi surface of electron and hole pockets encapsulating the nodal line. Moreover, the underlying two-band model to describe a nodal line is not unique, in that there are two classes of Hamiltonian with distinct band topology giving rise to the same Fermi-surface geometry. After identifying the extremal cyclotron orbits in various magnetic field directions, we study their concomitant Landau levels and resulting quantum oscillation signatures. By Landau-fan-diagram analyses, we extract the nontrivial π Berry phase signature for extremal orbits linking the nodal line.

Nodes of Ranvier Act as Barriers to Restrict Invasion of Flanking Paranodal Domains in Myelinated Axons

PubMed Central

Thaxton, Courtney; Pillai, Anilkumar M.; Pribisko, Alaine L.; Dupree, Jeffrey L.; Bhat, Manzoor A.

2010-01-01

Accumulation of voltage gated sodium (Nav) channels at nodes of Ranvier is paramount for action potential propagation along myelinated fibers, yet the mechanisms governing nodal development, organization and stabilization remain unresolved. Here, we report that genetic ablation of the neuron-specific isoform of Neurofascin (NfascNF186) in vivo results in nodal disorganization, including loss of Nav channel and ankyrin-G (AnkG) enrichment at nodes in the peripheral (PNS) and central (CNS) nervous systems. Interestingly, the presence of paranodal domains failed to rescue nodal organization in the PNS and the CNS. Most importantly, using ultrastructural analysis, we demonstrate that the paranodal domains invade the nodal space in NfascNF186 mutant axons and occlude node formation. Our results suggest that NfascNF186-dependent assembly of the nodal complex acts as a molecular boundary to restrict the movement of flanking paranodal domains into the nodal area, thereby facilitating the stereotypic axonal domain organization and saltatory conduction along myelinated axons. PMID:21262464

A quantitative description of normal AV nodal conduction curve in man.

PubMed

Teague, S; Collins, S; Wu, D; Denes, P; Rosen, K; Arzbaecher, R

1976-01-01

The AV nodal conduction curve generated by the atrial extrastimulus technique has been described only qualitatively in man, making clinical comparison of known normal curves with those of suspected AV nodal dysfunction difficult. Also, the effects of physiological and pharmacological interventions have not been quantifiable. In 50 patients with normal AV conduction as defined by normal AH (less than 130 ms), normal AV nodal effective and functional refractory periods (less than 380 and less than 500 ms), and absence of demonstrable dual AV nodal pathways, we found that conduction curves (at sinus rhythm or longest paced cycle length) can be described by an exponential equation of the form delta = Ae-Bx. In this equation, delta is the increase in AV nodal conduction time of an extrastimulus compared to that of a regular beat and x is extrastimulus interval. The natural logarithm of this equation is linear in the semilogarithmic plane, thus permitting the constants A and B to be easily determined by a least-squares regression analysis with a hand calculator.

Topological nodal-line fermions in spin-orbit metal PbTaSe2

PubMed Central

Bian, Guang; Chang, Tay-Rong; Sankar, Raman; Xu, Su-Yang; Zheng, Hao; Neupert, Titus; Chiu, Ching-Kai; Huang, Shin-Ming; Chang, Guoqing; Belopolski, Ilya; Sanchez, Daniel S.; Neupane, Madhab; Alidoust, Nasser; Liu, Chang; Wang, BaoKai; Lee, Chi-Cheng; Jeng, Horng-Tay; Zhang, Chenglong; Yuan, Zhujun; Jia, Shuang; Bansil, Arun; Chou, Fangcheng; Lin, Hsin; Hasan, M. Zahid

2016-01-01

Topological semimetals can support one-dimensional Fermi lines or zero-dimensional Weyl points in momentum space, where the valence and conduction bands touch. While the degeneracy points in Weyl semimetals are robust against any perturbation that preserves translational symmetry, nodal lines require protection by additional crystalline symmetries such as mirror reflection. Here we report, based on a systematic theoretical study and a detailed experimental characterization, the existence of topological nodal-line states in the non-centrosymmetric compound PbTaSe2 with strong spin-orbit coupling. Remarkably, the spin-orbit nodal lines in PbTaSe2 are not only protected by the reflection symmetry but also characterized by an integer topological invariant. Our detailed angle-resolved photoemission measurements, first-principles simulations and theoretical topological analysis illustrate the physical mechanism underlying the formation of the topological nodal-line states and associated surface states for the first time, thus paving the way towards exploring the exotic properties of the topological nodal-line fermions in condensed matter systems. PMID:26829889

Characterization of L-type calcium channel activity in atrioventricular nodal myocytes from rats with streptozotocin-induced Diabetes mellitus

PubMed Central

Yuill, Kathryn H; Al Kury, Lina T; Howarth, Frank Christopher

2015-01-01

Cardiovascular complications are common in patients with Diabetes mellitus (DM). In addition to changes in cardiac muscle inotropy, electrical abnormalities are also commonly observed in these patients. We have previously shown that spontaneous cellular electrical activity is altered in atrioventricular nodal (AVN) myocytes, isolated from the streptozotocin (STZ) rat model of type-1 DM. In this study, utilizing the same model, we have characterized the changes in L-type calcium channel activity in single AVN myocytes. Ionic currents were recorded from AVN myocytes isolated from the hearts of control rats and from those with STZ-induced diabetes. Patch-clamp recordings were used to assess the changes in cellular electrical activity in individual myocytes. Type-1 DM significantly altered the cellular characteristics of L-type calcium current. A reduction in peak ICaL density was observed, with no corresponding changes in the activation parameters of the current. L-type calcium channel current also exhibited faster time-dependent inactivation in AVN myocytes from diabetic rats. A negative shift in the voltage dependence of inactivation was also evident, and a slowing of restitution parameters. These findings demonstrate that experimentally induced type-1 DM significantly alters AVN L-type calcium channel cellular electrophysiology. These changes in ion channel activity may contribute to the abnormalities in cardiac electrical function that are associated with high mortality levels in patients with DM. PMID:26603460

Axonal Dysfunction Precedes Motor Neuronal Death in Amyotrophic Lateral Sclerosis

PubMed Central

Iwai, Yuta; Shibuya, Kazumoto; Misawa, Sonoko; Sekiguchi, Yukari; Watanabe, Keisuke; Amino, Hiroshi; Kuwabara, Satoshi

2016-01-01

Wide-spread fasciculations are a characteristic feature in amyotrophic lateral sclerosis (ALS), suggesting motor axonal hyperexcitability. Previous excitability studies have shown increased nodal persistent sodium conductances and decreased potassium currents in motor axons of ALS patients, both of the changes inducing hyperexcitability. Altered axonal excitability potentially contributes to motor neuron death in ALS, but the relationship of the extent of motor neuronal death and abnormal excitability has not been fully elucidated. We performed multiple nerve excitability measurements in the median nerve at the wrist of 140 ALS patients and analyzed the relationship of compound muscle action potential (CMAP) amplitude (index of motor neuronal loss) and excitability indices, such as strength-duration time constant, threshold electrotonus, recovery cycle and current-threshold relationships. Compared to age-matched normal controls (n = 44), ALS patients (n = 140) had longer strength-duration time constant (SDTC: a measure of nodal persistent sodium current; p < 0.05), greater threshold changes in depolarizing threshold electrotonus (p < 0.05) and depolarizing current threshold relationship (i.e. less accommodation; (p < 0.05), greater superexcitability (a measure of fast potassium current; p < 0.05) and reduced late subexcitability (a measure of slow potassium current; p < 0.05), suggesting increased persistent sodium currents and decreased potassium currents. The reduced potassium currents were found even in the patient subgroups with normal CMAP (> 5mV). Regression analyses showed that SDTC (R = -0.22) and depolarizing threshold electrotonus (R = -0.22) increased with CMAP decline. These findings suggest that motor nerve hyperexcitability occurs in the early stage of the disease, and precedes motor neuronal loss in ALS. Modulation of altered ion channel function could be a treatment option for ALS. PMID:27383069

Sensitive molecular detection of small nodal metastasis in uterine cervical cancer using HPV16-E6/CK19/MUC1 cancer biomarkers.

PubMed

Samouëlian, Vanessa; Mechtouf, Nawel; Leblanc, Eric; Cardin, Guillaume B; Lhotellier, Valérie; Querleu, Denis; Révillion, Françoise; Rodier, Francis

2018-04-24

Metastatic nodal involvement is a critical prognostic factor in uterine cervical cancer (UCC). To improve current methods of detecting UCC metastases in lymph nodes (LNs), we used quantitative PCR (qPCR) to assess mRNA expression of potential metastatic biomarkers. We found that expression of HPV16-E6, cytokeratin19 (CK19), and mucin1 (MUC1) is consistently upregulated in tumors and metastatic tissues, supporting a role for these genes in UCC progression. These putative biomarkers were able to predict the presence of histologically positive metastatic LNs with respective sensitivities and specificities of 82% and 99% (CK19), 76% and 95% (HPV16-E6), and 76% and 78% (MUC1). While the biomarkers failed to detect 1.7% to 2.2% of the histologically positive LNs when used individually, combining CK19 and HPV16-E6 enhanced sensitivity and specificity to 100% and 94%, respectively. To explore the sensitivity of qPCR-based detection of varying proportions of invading HPV16-positive UCC cells, we designed a LN metastasis model that achieved a fresh cell detection limit of 0.008% (1:12500 HPV16-positive to HPV16-negative cells), and a paraffin-embedded, formalin-fixed (PEFF) detection limit of 0.02% (1:5000 HPV16-positive to HPV16-negative cells), both of which are within the theoretical detection limit for micrometastasis. Thus, HPV E6/E7 oncogenes may be useful targets for the ultrasensitive detection of nodal involvements like micrometastases in fresh or archived tissue samples. Moreover, our results suggest that the biomarker combination of CK19/HPV-E6 could support a real-time intraoperative strategy for the detection of small, but potentially lethal, metastatic nodal involvements in fresh UCC tissues.

Utility of Adjuvant Chemotherapy After Neoadjuvant Chemoradiation and Esophagectomy for Esophageal Cancer.

PubMed

Burt, Bryan M; Groth, Shawn S; Sada, Yvonne H; Farjah, Farhood; Cornwell, Lorraine; Sugarbaker, David J; Massarweh, Nader N

2017-08-01

To determine whether adjuvant chemotherapy (AC) after neoadjuvant chemoradiation and esophagectomy is associated with improved overall survival for patients with locally advanced esophageal cancer, and to evaluate how pathologic disease response to neoadjuvant treatment impacts this effect. Neoadjuvant chemoradiation is currently the preferred management approach for locoregional esophageal cancer. Although there is interest in the use of AC, the benefit of systemic therapy after neoadjuvant chemoradiation and esophagectomy is unclear. Retrospective cohort study of patients with esophageal cancer treated with neoadjuvant chemoradiation and esophagectomy in the National Cancer Data Base (2006-2012). Among 3592 patients with esophageal cancer (84.7% adenocarcinoma, 15.2% squamous cell carcinoma), 335 (9.3%) were treated with AC. AC was not associated with a significantly lower risk of death among patients with no residual disease (ypT0N0) or residual non-nodal disease (ypT+N0). Among patients with residual nodal disease (ypTanyN+), AC was associated with a 30% lower risk of death in the overall cohort [hazard ratio (HR) 0.70, (0.57-0.85)] and among those with adenocarcinoma [HR 0.69 (0.57-0.85)]. Using a 90-day postoperative landmark, findings were similar. Among patients with postoperative length of stay ≤10 days and no unplanned readmission, AC was associated with approximately 40% lower risk of death among patients with residual nodal disease [overall cohort, HR 0.63 (0.48-0.84); adenocarcinoma, HR 0.66 (0.49-0.88)]. AC after neoadjuvant chemoradiation and esophagectomy is associated with improved survival in patients with residual nodal disease. Our findings suggest AC may provide additional benefit for esophageal cancer patients, and merits further investigation.

Left Septal Slow Pathway Ablation for Atrioventricular Nodal Reentrant Tachycardia.

PubMed

Katritsis, Demosthenes G; John, Roy M; Latchamsetty, Rakesh; Muthalaly, Rahul G; Zografos, Theodoros; Katritsis, George D; Stevenson, William G; Efimov, Igor R; Morady, Fred

2018-03-01

Immunohistochemistry studies suggest that the anatomic substrate of the slow pathway in atrioventricular nodal reentrant tachycardia (AVNRT) is the left inferior nodal extension. We hypothesized that slow pathway ablation from the left septum is an effective alternative to right-sided ablation. We analyzed our databases of AVNRT in search of cases that had used slow pathway ablation from the left septum because of failure of right septal ablation, and then prospectively subjected consenting patients to a left septal-only procedure. Of 1342 patients subjected to right septal slow pathway ablation for AVNRT, 15 patients, 11 with typical and 4 with atypical AVNRT, had a left septal approach after unsuccessful right-sided ablation (R+L group). Eleven patients were subjected to a left septal-only approach for slow pathway ablation without a previous right septal attempt (L group). Fluoroscopy times in the R+L and L groups were 30.5 (21.0-44.0) and 20.0 (17.0-25.0) minutes, respectively ( P =0.061), and radiofrequency current delivery times were 11.3 (5.0-19.1) and 10.0 (7.0-12.0) minutes, respectively ( P =0.897). There was no need for additional ablation lesions at other anatomic sites in either group, and no cases of atrioventricular block were encountered. Recurrence rates of the arrhythmia for the R+L and L groups were 6.7% and 0%, respectively, in the 3 months after ablation ( P =1.000). Left septal ablation at the anatomic site of the left inferior nodal extension is an alternative for ablation of both typical and atypical AVNRT when ablation at the right posterior septum is ineffective. © 2018 American Heart Association, Inc.

Topologically convergent and divergent functional connectivity patterns in unmedicated unipolar depression and bipolar disorder.

PubMed

Wang, Y; Wang, J; Jia, Y; Zhong, S; Zhong, M; Sun, Y; Niu, M; Zhao, L; Zhao, L; Pan, J; Huang, L; Huang, R

2017-07-04

Bipolar disorder (BD), particularly BD II, is frequently misdiagnosed as unipolar depression (UD), leading to inappropriate treatment and poor clinical outcomes. Although depressive symptoms may be expressed similarly in UD and BD, the similarities and differences in the architecture of brain functional networks between the two disorders are still unknown. In this study, we hypothesized that UD and BD II patients would show convergent and divergent patterns of disrupted topological organization of the functional connectome, especially in the default mode network (DMN) and the limbic network. Brain resting-state functional magnetic resonance imaging (fMRI) data were acquired from 32 UD-unmedicated patients, 31 unmedicated BD II patients (current episode depressed) and 43 healthy subjects. Using graph theory, we systematically studied the topological organization of their whole-brain functional networks at the following three levels: whole brain, modularity and node. First, both the UD and BD II patients showed increased characteristic path length and decreased global efficiency compared with the controls. Second, both the UD and BD II patients showed disrupted intramodular connectivity within the DMN and limbic system network. Third, decreased nodal characteristics (nodal strength and nodal efficiency) were found predominantly in brain regions in the DMN, limbic network and cerebellum of both the UD and BD II patients, whereas differences between the UD and BD II patients in the nodal characteristics were also observed in the precuneus and temporal pole. Convergent deficits in the topological organization of the whole brain, DMN and limbic networks may reflect overlapping pathophysiological processes in unipolar and bipolar depression. Our discovery of divergent regional connectivity that supports emotion processing could help to identify biomarkers that will aid in differentiating these disorders.

Topologically convergent and divergent functional connectivity patterns in unmedicated unipolar depression and bipolar disorder

PubMed Central

Wang, Y; Wang, J; Jia, Y; Zhong, S; Zhong, M; Sun, Y; Niu, M; Zhao, L; Zhao, L; Pan, J; Huang, L; Huang, R

2017-01-01

Bipolar disorder (BD), particularly BD II, is frequently misdiagnosed as unipolar depression (UD), leading to inappropriate treatment and poor clinical outcomes. Although depressive symptoms may be expressed similarly in UD and BD, the similarities and differences in the architecture of brain functional networks between the two disorders are still unknown. In this study, we hypothesized that UD and BD II patients would show convergent and divergent patterns of disrupted topological organization of the functional connectome, especially in the default mode network (DMN) and the limbic network. Brain resting-state functional magnetic resonance imaging (fMRI) data were acquired from 32 UD-unmedicated patients, 31 unmedicated BD II patients (current episode depressed) and 43 healthy subjects. Using graph theory, we systematically studied the topological organization of their whole-brain functional networks at the following three levels: whole brain, modularity and node. First, both the UD and BD II patients showed increased characteristic path length and decreased global efficiency compared with the controls. Second, both the UD and BD II patients showed disrupted intramodular connectivity within the DMN and limbic system network. Third, decreased nodal characteristics (nodal strength and nodal efficiency) were found predominantly in brain regions in the DMN, limbic network and cerebellum of both the UD and BD II patients, whereas differences between the UD and BD II patients in the nodal characteristics were also observed in the precuneus and temporal pole. Convergent deficits in the topological organization of the whole brain, DMN and limbic networks may reflect overlapping pathophysiological processes in unipolar and bipolar depression. Our discovery of divergent regional connectivity that supports emotion processing could help to identify biomarkers that will aid in differentiating these disorders. PMID:28675389

Acoustic and Perceptual Effects of Left–Right Laryngeal Asymmetries Based on Computational Modeling

PubMed Central

Samlan, Robin A.; Story, Brad H.; Lotto, Andrew J.; Bunton, Kate

2015-01-01

Purpose Computational modeling was used to examine the consequences of 5 different laryngeal asymmetries on acoustic and perceptual measures of vocal function. Method A kinematic vocal fold model was used to impose 5 laryngeal asymmetries: adduction, edge bulging, nodal point ratio, amplitude of vibration, and starting phase. Thirty /a/ and /I/ vowels were generated for each asymmetry and analyzed acoustically using cepstral peak prominence (CPP), harmonics-to-noise ratio (HNR), and 3 measures of spectral slope (H1*-H2*, B0-B1, and B0-B2). Twenty listeners rated voice quality for a subset of the productions. Results Increasingly asymmetric adduction, bulging, and nodal point ratio explained significant variance in perceptual rating (R2 = .05, p < .001). The same factors resulted in generally decreasing CPP, HNR, and B0-B2 and in increasing B0-B1. Of the acoustic measures, only CPP explained significant variance in perceived quality (R2 = .14, p < .001). Increasingly asymmetric amplitude of vibration or starting phase minimally altered vocal function or voice quality. Conclusion Asymmetries of adduction, bulging, and nodal point ratio drove acoustic measures and perception in the current study, whereas asymmetric amplitude of vibration and starting phase demonstrated minimal influence on the acoustic signal or voice quality. PMID:24845730

Occult nodal metastasis in solid carcinomata

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

Moloy, P.J.; Nicolson, G.L.

1987-01-01

This book contains 23 selections. Some of the titles are: Rationale for radiotherapy in subclinical nodal disease; rationale of chemotherapy for nodal disease: The stabilization of topoisomerase II-DNA complexes as a mechanism of antineoplastic drug action; magnetic resonance imaging of malignant cervical adenopathy; and local and regional immune function in cancer patients.

Localization of malignant melanoma using monoclonal antibodies

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

Wasselle, J.; Becker, J.; Cruse, W.

1991-04-01

Finding a screening test to evaluate patients with cancer for occult metastatic disease, as well as imaging all known disease, is a goal of research efforts. Twenty-nine evaluable patients with deeply invasive (stage I), regional nodal (stage II), or systemic (stage III) melanoma underwent imaging by administration of a preparation of the antimelanoma antibody labeled with technetium 99m. Scan results indicated that 28 of 32 confirmed metastatic sites were imaged with this technique (88% sensitivity). Analysis of the individual positive sites revealed that nodal basins and visceral metastases accounted for the highest percentage of metastatic sites imaged, with 14 (88%)more » of 16 nodal basin metastases and all four visceral metastases being detected through imaging. Occult nodal disease was detected in the iliac nodal chain in two of the 29 patients. The imaging of benign tumors and nodal basins not containing disease accounted for a confirmed false-positive rate of 21%. Three (10%) of the 29 scan results were confirmed to be false-negative. In vivo tumor localization with monoclonal antibodies showed a sensitivity similar to that of other roentgenographic procedures for identifying metastatic disease and was useful in two of three patients in identifying occult iliac nodal disease, a region that is difficult to evaluate with physical examination and other imaging modalities.« less

Nodal enhances the activity of FoxO3a and its synergistic interaction with Smads to regulate cyclin G2 transcription in ovarian cancer cells.

PubMed

Fu, G; Peng, C

2011-09-15

Nodal, a member of the transforming growth factor-β superfamily, has been recently shown to suppress cell proliferation and to stimulate the expression of cyclin G2 (CCNG2) in human epithelial ovarian cancer cells. However, the precise mechanisms underlying these events are not fully understood. In this study, we investigated the transcriptional regulation of CCNG2 by the Nodal signaling pathway. In ovarian cancer cells, overexpression of Nodal or its receptors, activin receptor-like kinase 7 (ALK7) or ALK4, resulted in an increase in the CCNG2 promoter activity. Several putative Forkhead box class O (FoxO)3a-binding sites are present in the human CCNG2 promoter and overexpression of FoxO3a enhanced the CCNG2 promoter activity. The functional FoxO3a-binding element (FBE) was mapped to a proximal region located between -398 and -380 bp (FBE1) through deletion and mutation analyses, as well as chromatin immunoprecipitation (IP) assay. Interestingly, mutation of the FBE1 not only abolished the effect of FoxO3a, but also blocked Nodal-induced CCNG2 transcription. Nodal stimulated FoxO3a mRNA and protein expression through the canonical Smad pathway and suppressed FoxO3a inactivation by inhibiting AKT activity. Silencing of FoxO3a using small interfering RNA significantly reduced the effect of Nodal on the CCNG2 promoter activity. On the other hand, overexpression of Smad2 and Smad3 enhanced the FoxO3a-induced CCNG2 promoter activity whereas knockdown of Smad4 blocked the activity of FoxO3a. Furthermore, IP assays revealed that FoxO3a formed complexes with Smad proteins and that Nodal enhanced the binding of FoxO3a to the CCNG2 promoter. Finally, silencing of FoxO3a reversed the inhibitory effect of Nodal on cell proliferation. Taken together, these findings demonstrated that Nodal signaling promotes CCNG2 transcription by upregulating FoxO3a expression, inhibiting FoxO3a phosphorylation and enhancing its synergistic interaction with Smads. These results also suggest that FoxO3a is an important mediator of Nodal signaling in ovarian cancer cells.

Anatomic Distribution of Fluorodeoxyglucose-Avid Para-aortic Lymph Nodes in Patients With Cervical Cancer

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

Takiar, Vinita; Fontanilla, Hiral P.; Eifel, Patricia J.

Purpose: Conformal treatment of para-aortic lymph nodes (PAN) in cervical cancer allows dose escalation and reduces normal tissue toxicity. Currently, data documenting the precise location of involved PAN are lacking. We define the spatial distribution of this high-risk nodal volume by analyzing fluorodeoxyglucose (FDG)-avid lymph nodes (LNs) on positron emission tomography/computed tomography (PET/CT) scans in patients with cervical cancer. Methods and Materials: We identified 72 PANs on pretreatment PET/CT of 30 patients with newly diagnosed stage IB-IVA cervical cancer treated with definitive chemoradiation. LNs were classified as left-lateral para-aortic (LPA), aortocaval (AC), or right paracaval (RPC). Distances from the LNmore » center to the closest vessel and adjacent vertebral body were calculated. Using deformable image registration, nodes were mapped to a template computed tomogram to provide a visual impression of nodal frequencies and anatomic distribution. Results: We identified 72 PET-positive para-aortic lymph nodes (37 LPA, 32 AC, 3 RPC). All RPC lymph nodes were in the inferior third of the para-aortic region. The mean distance from aorta for all lymph nodes was 8.3 mm (range, 3-17 mm), and from the inferior vena cava was 5.6 mm (range, 2-10 mm). Of the 72 lymph nodes, 60% were in the inferior third, 36% were in the middle third, and 4% were in the upper third of the para-aortic region. In all, 29 of 30 patients also had FDG-avid pelvic lymph nodes. Conclusions: A total of 96% of PET positive nodes were adjacent to the aorta; PET positive nodes to the right of the IVC were rare and were all located distally, within 3 cm of the aortic bifurcation. Our findings suggest that circumferential margins around the vessels do not accurately define the nodal region at risk. Instead, the anatomical extent of the nodal basin should be contoured on each axial image to provide optimal coverage of the para-aortic nodal compartment.« less

Outcomes of Patients With Head-and-Neck Cancer of Unknown Primary Origin Treated With Intensity-Modulated Radiotherapy

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

Shoushtari, Asal; Saylor, Drew; Kerr, Kara-Lynne

2011-11-01

Purpose: To analyze survival, failure patterns, and toxicity in patients with head-and-neck carcinoma of unknown primary origin (HNCUP) treated with intensity-modulated radiotherapy (IMRT). Methods and materials: Records from 27 patients with HNCUP treated during the period 2002-2008 with IMRT were reviewed retrospectively. Nodal staging ranged from N1 to N3. The mean preoperative dose to gross or suspected disease, Waldeyer's ring, and uninvolved bilateral cervical nodes was 59.4, 53.5, and 51.0 Gy, respectively. Sixteen patients underwent neck dissection after radiation and 4 patients before radiation. Eight patients with advanced nodal disease (N2b-c, N3) or extracapsular extension received chemotherapy. Results: With amore » median follow-up of 41.9 months (range, 25.3-93.9 months) for nondeceased patients, the 5-year actuarial overall survival, disease-free survival, and nodal control rates were 70.9%, 85.2%, and 88.5%, respectively. Actuarial disease-free survival rates for N1, N2, and N3 disease were 100%, 94.1%, and 50.0%, respectively, at 5 years. When stratified by nonadvanced (N1, N2a nodal disease without extracapsular spread) vs. advanced nodal disease (N2b, N2c, N3), the 5-year actuarial disease-free survival rate for the nonadvanced nodal disease group was 100%, whereas for the advanced nodal disease group it was significantly lower at 66.7% (p = 0.017). Three nodal recurrences were observed: in 1 patient with bulky N2b disease and 2 in patients with N3 disease. No nodal failures occurred in patients with N1 or N2a disease who received only radiation and surgery. Conclusion: Definitive IMRT to 50-56 Gy followed by neck dissection results in excellent nodal control and overall and disease-free survival, with acceptable toxicity for patients with T0N1 or nonbulky T0N2a disease without extracapsular spread. Patients with extracapsular spread, advanced N2 disease, or N3 disease may benefit from concurrent chemotherapy, targeted therapeutic agents, or accelerated radiation regimens in addition to surgery.« less

Introducing graph theory to track for neuroplastic alterations in the resting human brain: a transcranial direct current stimulation study.

PubMed

Polanía, Rafael; Paulus, Walter; Antal, Andrea; Nitsche, Michael A

2011-02-01

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that alters cortical excitability and activity in a polarity-dependent way. Stimulation for a few minutes has been shown to induce plastic alterations of cortical excitability and to improve cognitive performance. These effects might be related to stimulation-induced alterations of functional cortical network connectivity. We aimed to investigate the impact of tDCS on cortical network function by functional connectivity and graph theoretical analysis of the BOLD fMRI spontaneous activity. fMRI resting-state datasets were acquired immediately before and after 10-min bipolar tDCS during rest, with the anode placed over the left primary motor cortex (M1) and the cathode over the contralateral frontopolar cortex. For each dataset, grey matter voxel-based synchronization matrices were calculated and thresholded to construct undirected graphs. Nodal connectivity degree and minimum path length maps were calculated and compared before and after tDCS. Nodal minimum path lengths significantly increased in the left somatomotor (SM1) cortex after anodal tDCS, which means that the number of direct functional connections from the left SM1 to topologically distant grey matter voxels significantly decreased. In contrast, functional coupling between premotor and superior parietal areas with the left SM1 significantly increased. Additionally, the nodal connectivity degree in the left posterior cingulate cortex (PCC) area as well as in the right dorsolateral prefrontal cortex (right DLPFC) significantly increased. In summary, we provide initial support that tDCS-induced neuroplastic alterations might be related to functional connectivity changes in the human brain. Additionally, we propose our approach as a powerful method to track for neuroplastic changes in the human brain. Copyright © 2010 Elsevier Inc. All rights reserved.

The Effect of Anatomical Location of Lymph Node Metastases on Cancer Specific Survival in Patients with Clear Cell Renal Cell Carcinoma

PubMed Central

Nini, Alessandro; Larcher, Alessandro; Cianflone, Francesco; Trevisani, Francesco; Terrone, Carlo; Volpe, Alessandro; Regis, Federica; Briganti, Alberto; Salonia, Andrea; Montorsi, Francesco; Bertini, Roberto; Capitanio, Umberto

2018-01-01

Background Positive nodal status (pN1) is an independent predictor of survival in renal cell carcinoma (RCC) patients. However, no study to date has tested whether the location of lymph node (LN) metastases does affect oncologic outcomes in a population submitted to radical nephrectomy (RN) and extended lymph node dissection (eLND). Objective To describe nodal disease dissemination in clear cell RCC (ccRCC) patients and to assess the effect of the anatomical sites and the number of nodal areas affected on cancer specific mortality (CSM). Design, setting and partecipants The study included 415 patients who underwent RN and eLND, defined as the removal of hilar, side-specific (pre/paraaortic or pre/paracaval) and interaortocaval LNs for ccRCC, at two institutions. Outcome measurement and statistical analysis Descriptive statistics were used to depict nodal dissemination in pN1 patients, stratified according to nodal site and number of involved areas. Multivariable Cox regression analyses and Kaplan-Meier curves were used to explore the relationship between pN1 disease features and survival outcomes. Results and limitations Median number of removed LN was 14 (IQR 9–19); 23% of patients were pN1. Among patients with one involved nodal site, 54 and 26% of patients were positive only in side-specific and interaortocaval station, respectively. The most frequent nodal site was the interaortocaval and side-specific one, for right and left ccRCC, respectively. Interaortocaval nodal positivity (HR 2.3, CI 95%: 1.3–3.9, p < 0.01) represented an independent predictor of CSM. Conclusions When ccRCC patient harbour nodal disease, its spreading can occur at any nodal station without involving the others. The presence of interoartocaval positive nodes does affect oncologic outcomes. Patient summary Lymph node invasion in patients with clear cell renal cell carcinoma is not following a fixed anatomical pattern. An extended lymph node dissection, during treatment for primary kidney tumour, would aid patient risk stratification and multimodality upfront treatment. PMID:29740587

Patterns of nodal relapse after surgery and postoperative radiation therapy for carcinomas of the major and minor salivary glands: What is the role of elective neck irradiation?

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

Chen, Allen M.; Garcia, Joaquin; Lee, Nancy Y.

2007-03-15

Purpose: To evaluate the incidence of nodal relapses from carcinomas of the salivary glands among patients with clinically negative necks in an attempt to determine the potential utility of elective neck irradiation (ENI). Methods and Materials: Between 1960 and 2004, 251 patients with clinically N0 carcinomas of the salivary glands were treated with surgery and postoperative radiation therapy. None of the patients had undergone previous neck dissection. Histology was: adenoid cystic (84 patients), mucoepidermoid (60 patients), adenocarcinoma (58 patients), acinic cell (21 patients), undifferentiated (11 patients), carcinoma ex pleomorphic adenoma (7 patients), squamous cell (7 patients), and salivary duct carcinomamore » (3 patients); 131 patients (52%) had ENI. Median follow-up was 62 months (range, 3-267 months). Results: The 5- and 10-year actuarial estimates of nodal relapse were 11% and 13%, respectively. The 10-year actuarial rates of nodal failure were 7%, 5%, 12%, and 16%, for patients with T1, T2, T3, and T4 disease, respectively (p = 0.11). The use of ENI reduced the 10-year nodal failure rate from 26% to 0% (p = 0.0001). The highest crude rates of nodal relapse among those treated without ENI were found in patients with squamous cell carcinoma (67%), undifferentiated carcinoma (50%), adenocarcinoma (34%), and mucoepidermoid carcinoma (29%). There were no nodal failures observed among patients with adenoid cystic or acinic cell histology. Conclusion: ENI effectively prevents nodal relapses and should be used for select patients at high risk for regional failure.« less

47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... DEMS Nodal Station licenses should specify the maximum number of 10.6 GHz DEMS User Stations to be served by that nodal station. Any increase in that number must be applied for pursuant to § 1.913 of this... Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY...

47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... DEMS Nodal Station licenses should specify the maximum number of 10.6 GHz DEMS User Stations to be served by that nodal station. Any increase in that number must be applied for pursuant to § 1.913 of this... Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY...

47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... DEMS Nodal Station licenses should specify the maximum number of 10.6 GHz DEMS User Stations to be served by that nodal station. Any increase in that number must be applied for pursuant to § 1.913 of this... Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY...

47 CFR 101.503 - Digital Electronic Message Service Nodal Stations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... DEMS Nodal Station licenses should specify the maximum number of 10.6 GHz DEMS User Stations to be served by that nodal station. Any increase in that number must be applied for pursuant to § 1.913 of this... Stations. 101.503 Section 101.503 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY...

Topological nodal-line fermions in spin-orbit metal PbTaSe2

DOE PAGES

Bian, Guang; Chang, Tay-Rong; Sankar, Raman; ...

2016-02-02

Here we discuss how topological semimetals can support one-dimensional Fermi lines or zero-dimensional Weyl points in momentum space, where the valence and conduction bands touch. While the degeneracy points in Weyl semimetals are robust against any perturbation that preserves translational symmetry, nodal lines require protection by additional crystalline symmetries such as mirror reflection. Here we report, based on a systematic theoretical study and a detailed experimental characterization, the existence of topological nodal-line states in the non-centrosymmetric compound PbTaSe 2 with strong spin-orbit coupling. Remarkably, the spin-orbit nodal lines in PbTaSe 2 are not only protected by the reflection symmetry butmore » also characterized by an integer topological invariant. Our detailed angle-resolved photoemission measurements, first-principles simulations and theoretical topological analysis illustrate the physical mechanism underlying the formation of the topological nodal-line states and associated surface states for the first time, thus paving the way towards exploring the exotic properties of the topological nodal-line fermions in condensed matter systems.« less

Classification of reflection-symmetry-protected topological semimetals and nodal superconductors

NASA Astrophysics Data System (ADS)

Chiu, Ching-Kai; Schnyder, Andreas P.

2014-11-01

While the topological classification of insulators, semimetals, and superconductors in terms of nonspatial symmetries is well understood, less is known about topological states protected by crystalline symmetries, such as mirror reflections and rotations. In this work, we systematically classify topological semimetals and nodal superconductors that are protected, not only by nonspatial (i.e., global) symmetries, but also by a crystal reflection symmetry. We find that the classification crucially depends on (i) the codimension of the Fermi surface (nodal line or point) of the semimetal (superconductor), (ii) whether the mirror symmetry commutes or anticommutes with the nonspatial symmetries, and (iii) how the Fermi surfaces (nodal lines or points) transform under the mirror reflection and nonspatial symmetries. The classification is derived by examining all possible symmetry-allowed mass terms that can be added to the Bloch or Bogoliubov-de Gennes Hamiltonian in a given symmetry class and by explicitly deriving topological invariants. We discuss several examples of reflection-symmetry-protected topological semimetals and nodal superconductors, including topological crystalline semimetals with mirror Z2 numbers and topological crystalline nodal superconductors with mirror winding numbers.

Maternal Gdf3 is an obligatory cofactor in Nodal signaling for embryonic axis formation in zebrafish

PubMed Central

Bisgrove, Brent W; Su, Yi-Chu

2017-01-01

Zebrafish Gdf3 (Dvr1) is a member of the TGFβ superfamily of cell signaling ligands that includes Xenopus Vg1 and mammalian Gdf1/3. Surprisingly, engineered homozygous mutants in zebrafish have no apparent phenotype. Elimination of Gdf3 in oocytes of maternal-zygotic mutants results in embryonic lethality that can be fully rescued with gdf3 RNA, demonstrating that Gdf3 is required only early in development, beyond which mutants are viable and fertile. Gdf3 mutants are refractory to Nodal ligands and Nodal repressor Lefty1. Signaling driven by TGFβ ligand Activin and constitutively active receptors Alk4 and Alk2 remain intact in gdf3 mutants, indicating that Gdf3 functions at the same pathway step as Nodal. Targeting gdf3 and ndr2 RNA to specific lineages indicates that exogenous gdf3 is able to fully rescue mutants only when co-expressed with endogenous Nodal. Together, these findings demonstrate that Gdf3 is an essential cofactor of Nodal signaling during establishment of the embryonic axis. PMID:29140249

Unilateral dampening of Bmp activity by nodal generates cardiac left-right asymmetry.

PubMed

Veerkamp, Justus; Rudolph, Franziska; Cseresnyes, Zoltan; Priller, Florian; Otten, Cécile; Renz, Marc; Schaefer, Liliana; Abdelilah-Seyfried, Salim

2013-03-25

Signaling by Nodal and Bmp is essential for cardiac laterality. How activities of these pathways translate into left-right asymmetric organ morphogenesis is largely unknown. We show that, in zebrafish, Nodal locally reduces Bmp activity on the left side of the cardiac field. This effect is mediated by the extracellular matrix enzyme Hyaluronan synthase 2, expression of which is induced by Nodal. Unilateral reduction of Bmp signaling results in lower expression of nonmuscle myosin II and higher cell motility on the left, driving asymmetric displacement of the entire cardiac field. In silico modeling shows that left-right differences in cell motility are sufficient to induce a robust, directional migration of cardiac tissue. Thus, the mechanism underlying the formation of cardiac left-right asymmetry involves Nodal modulating an antimotogenic Bmp activity. Copyright © 2013 Elsevier Inc. All rights reserved.

Nodal aberration theory for wild-filed asymmetric optical systems

NASA Astrophysics Data System (ADS)

Chen, Yang; Cheng, Xuemin; Hao, Qun

2016-10-01

Nodal Aberration Theory (NAT) was used to calculate the zero field position in Full Field Display (FFD) for the given aberration term. Aiming at wide-filed non-rotational symmetric decentered optical systems, we have presented the nodal geography behavior of the family of third-order and fifth-order aberrations. Meanwhile, we have calculated the wavefront aberration expressions when one optical element in the system is tilted, which was not at the entrance pupil. By using a three-piece-cellphone lens example in optical design software CodeV, the nodal geography is testified under several situations; and the wavefront aberrations are calculated when the optical element is tilted. The properties of the nodal aberrations are analyzed by using Fringe Zernike coefficients, which are directly related with the wavefront aberration terms and usually obtained by real ray trace and wavefront surface fitting.

A nodal signaling pathway regulates the laterality of neuroanatomical asymmetries in the zebrafish forebrain.

PubMed

Concha, M L; Burdine, R D; Russell, C; Schier, A F; Wilson, S W

2000-11-01

Animals show behavioral asymmetries that are mediated by differences between the left and right sides of the brain. We report that the laterality of asymmetric development of the diencephalic habenular nuclei and the photoreceptive pineal complex is regulated by the Nodal signaling pathway and by midline tissue. Analysis of zebrafish embryos with compromised Nodal signaling reveals an early role for this pathway in the repression of asymmetrically expressed genes in the diencephalon. Later signaling mediated by the EGF-CFC protein One-eyed pinhead and the forkhead transcription factor Schmalspur is required to overcome this repression. When expression of Nodal pathway genes is either absent or symmetrical, neuroanatomical asymmetries are still established but are randomized. This indicates that Nodal signaling is not required for asymmetric development per se but is essential to determine the laterality of the asymmetry.

Regional Nodal Irradiation in Early-Stage Breast Cancer.

PubMed

Whelan, Timothy J; Olivotto, Ivo A; Parulekar, Wendy R; Ackerman, Ida; Chua, Boon H; Nabid, Abdenour; Vallis, Katherine A; White, Julia R; Rousseau, Pierre; Fortin, Andre; Pierce, Lori J; Manchul, Lee; Chafe, Susan; Nolan, Maureen C; Craighead, Peter; Bowen, Julie; McCready, David R; Pritchard, Kathleen I; Gelmon, Karen; Murray, Yvonne; Chapman, Judy-Anne W; Chen, Bingshu E; Levine, Mark N

2015-07-23

Most women with breast cancer who undergo breast-conserving surgery receive whole-breast irradiation. We examined whether the addition of regional nodal irradiation to whole-breast irradiation improved outcomes. We randomly assigned women with node-positive or high-risk node-negative breast cancer who were treated with breast-conserving surgery and adjuvant systemic therapy to undergo either whole-breast irradiation plus regional nodal irradiation (including internal mammary, supraclavicular, and axillary lymph nodes) (nodal-irradiation group) or whole-breast irradiation alone (control group). The primary outcome was overall survival. Secondary outcomes were disease-free survival, isolated locoregional disease-free survival, and distant disease-free survival. Between March 2000 and February 2007, a total of 1832 women were assigned to the nodal-irradiation group or the control group (916 women in each group). The median follow-up was 9.5 years. At the 10-year follow-up, there was no significant between-group difference in survival, with a rate of 82.8% in the nodal-irradiation group and 81.8% in the control group (hazard ratio, 0.91; 95% confidence interval [CI], 0.72 to 1.13; P=0.38). The rates of disease-free survival were 82.0% in the nodal-irradiation group and 77.0% in the control group (hazard ratio, 0.76; 95% CI, 0.61 to 0.94; P=0.01). Patients in the nodal-irradiation group had higher rates of grade 2 or greater acute pneumonitis (1.2% vs. 0.2%, P=0.01) and lymphedema (8.4% vs. 4.5%, P=0.001). Among women with node-positive or high-risk node-negative breast cancer, the addition of regional nodal irradiation to whole-breast irradiation did not improve overall survival but reduced the rate of breast-cancer recurrence. (Funded by the Canadian Cancer Society Research Institute and others; MA.20 ClinicalTrials.gov number, NCT00005957.).

Dose-volume effects in pathologic lymph nodes in locally advanced cervical cancer.

PubMed

Bacorro, Warren; Dumas, Isabelle; Escande, Alexandre; Gouy, Sebastien; Bentivegna, Enrica; Morice, Philippe; Haie-Meder, Christine; Chargari, Cyrus

2018-03-01

In cervical cancer patients, dose-volume relationships have been demonstrated for tumor and organs-at-risk, but not for pathologic nodes. The nodal control probability (NCP) according to dose/volume parameters was investigated. Patients with node-positive cervical cancer treated curatively with external beam radiotherapy (EBRT) and image-guided brachytherapy (IGABT) were identified. Nodal doses during EBRT, IGABT and boost were converted to 2-Gy equivalent (α/β = 10 Gy) and summed. Pathologic nodes were followed individually from diagnosis to relapse. Statistical analyses comprised log-rank tests (univariate analyses), Cox proportional model (factors with p ≤ 0.1 in univariate) and Probit analyses. A total of 108 patients with 254 unresected pathological nodes were identified. The mean nodal volume at diagnosis was 3.4 ± 5.8 cm 3 . The mean total nodal EQD2 doses were 55.3 ± 5.6 Gy. Concurrent chemotherapy was given in 96%. With a median follow-up of 33.5 months, 20 patients (18.5%) experienced relapse in nodes considered pathologic at diagnosis. Overall nodal recurrence rate was 9.1% (23/254). On univariate analyses, nodal volume (threshold: 3 cm 3 , p < .0001) and lymph node dose (≥57.5 Gy α/β10 , p = .039) were significant for nodal control. The use of simultaneous boost was borderline for significance (p = .07). On multivariate analysis, volume (HR = 8.2, 4.0-16.6, p < .0001) and dose (HR = 2, 1.05-3.9, p = .034) remained independent factors. Probit analysis combining dose and volume showed significant relationships with NCP, with increasing gap between the curves with higher nodal volumes. A nodal dose-volume effect on NCP is demonstrated for the first time, with increasing NCP benefit of additional doses to higher-volume nodes. Copyright © 2018 Elsevier Inc. All rights reserved.

SU-E-J-179: Prediction of Pelvic Nodal Coverage Using Mutual Information Between Cone-Beam and Planning CTs

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

Jani, S; Kishan, A; O'Connell, D

2014-06-01

Purpose: To investigate if pelvic nodal coverage for prostate patients undergoing intensity modulated radiotherapy (IMRT) can be predicted using mutual image information computed between planning and cone-beam CTs (CBCTs). Methods: Four patients with high-risk prostate adenocarcinoma were treated with IMRT on a Varian TrueBeam. Plans were designed such that 95% of the nodal planning target volume (PTV) received the prescription dose of 45 Gy (N=1) or 50.4 Gy (N=3). Weekly CBCTs (N=25) were acquired and the nodal clinical target volumes and organs at risk were contoured by a physician. The percent nodal volume receiving prescription dose was recorded as amore » ground truth. Using the recorded shifts performed by the radiation therapists at the time of image acquisition, CBCTs were aligned with the planning kVCT. Mutual image information (MI) was calculated between the CBCT and the aligned planning CT within the contour of the nodal PTV. Due to variable CBCT fields-of-view, CBCT images covering less than 90% of the nodal volume were excluded from the analysis, resulting in the removal of eight CBCTs. Results: A correlation coefficient of 0.40 was observed between the MI metric and the percent of the nodal target volume receiving the prescription dose. One patient's CBCTs had clear outliers from the rest of the patients. Upon further investigation, we discovered image artifacts that were present only in that patient's images. When those four images were excluded, the correlation improved to 0.81. Conclusion: This pilot study shows the potential of predicting pelvic nodal dosimetry by computing the mutual image information between planning CTs and patient setup CBCTs. Importantly, this technique does not involve manual or automatic contouring of the CBCT images. Additional patients and more robust exclusion criteria will help validate our findings.« less

Tumour thickness as a predictor of nodal metastases in oral cancer: comparison between tongue and floor of mouth subsites.

PubMed

Balasubramanian, Deepak; Ebrahimi, Ardalan; Gupta, Ruta; Gao, Kan; Elliott, Michael; Palme, Carsten E; Clark, Jonathan R

2014-12-01

To identify whether tumour thickness as a predictor of nodal metastases in oral squamous cell carcinoma differs between tongue and floor of mouth (FOM) subsites. Retrospective review of 343 patients treated between 1987 and 2012. The neck was considered positive in the presence of pathologically proven nodal metastases on neck dissection or during follow-up. There were 222 oral tongue and 121 FOM tumours. In patients with FOM tumours 2.1-4mm thick, the rate of nodal metastases was 41.7%. In contrast, for tongue cancers of a similar thickness the rate was only 11.2%. This increased to 38.5% in patients with tongue cancers that were 4.1-6mm thick. Comparing these two subsites, FOM cancers cross the critical 20% threshold of probability for nodal metastases between 1 and 2mm whereas tongue cancers cross the 20% threshold just under 4mm thickness. On logistic regression adjusting for relevant covariates, there was a significant difference in the propensity for nodal metastases based on tumour thickness according to subsite (p=0.028). Thin FOM tumours (2.1-4mm) have a high rate of nodal metastases. Elective neck dissection is appropriate in FOM tumours ⩾2mm thick and in tongue tumours ⩾4mm thick. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nodal signalling determines biradial asymmetry in Hydra.

PubMed

Watanabe, Hiroshi; Schmidt, Heiko A; Kuhn, Anne; Höger, Stefanie K; Kocagöz, Yigit; Laumann-Lipp, Nico; Ozbek, Suat; Holstein, Thomas W

2014-11-06

In bilaterians, three orthogonal body axes define the animal form, with distinct anterior-posterior, dorsal-ventral and left-right asymmetries. The key signalling factors are Wnt family proteins for the anterior-posterior axis, Bmp family proteins for the dorsal-ventral axis and Nodal for the left-right axis. Cnidarians, the sister group to bilaterians, are characterized by one oral-aboral body axis, which exhibits a distinct biradiality of unknown molecular nature. Here we analysed the biradial growth pattern in the radially symmetrical cnidarian polyp Hydra, and we report evidence of Nodal in a pre-bilaterian clade. We identified a Nodal-related gene (Ndr) in Hydra magnipapillata, and this gene is essential for setting up an axial asymmetry along the main body axis. This asymmetry defines a lateral signalling centre, inducing a new body axis of a budding polyp orthogonal to the mother polyp's axis. Ndr is expressed exclusively in the lateral bud anlage and induces Pitx, which encodes an evolutionarily conserved transcription factor that functions downstream of Nodal. Reminiscent of its function in vertebrates, Nodal acts downstream of β-Catenin signalling. Our data support an evolutionary scenario in which a 'core-signalling cassette' consisting of β-Catenin, Nodal and Pitx pre-dated the cnidarian-bilaterian split. We presume that this cassette was co-opted for various modes of axial patterning: for example, for lateral branching in cnidarians and left-right patterning in bilaterians.

The accuracy of preoperative axillary nodal staging in primary breast cancer by ultrasound is modified by nodal metastatic load and tumor biology

PubMed Central

Dihge, Looket; Grabau, Dorthe A.; Rasmussen, Rogvi W.; Bendahl, Pär-Ola; Rydén, Lisa

2016-01-01

Abstract Background The outcome of axillary ultrasound (AUS) with fine-needle aspiration biopsy (FNAB) in the diagnostic work-up of primary breast cancer has an impact on therapy decisions. We hypothesize that the accuracy of AUS is modified by nodal metastatic burden and clinico-pathological characteristics. Material and methods The performance of AUS and AUS-guided FNAB for predicting nodal metastases was assessed in a prospective breast cancer cohort subjected for surgery during 2009–2012. Predictors of accuracy were included in multivariate analysis. Results AUS had a sensitivity of 23% and a specificity of 95%, while AUS-guided FNAB obtained 73% and 100%, respectively. AUS-FNAB exclusively detected macro-metastases (median four metastases) and identified patients with more extensive nodal metastatic burden in comparison with sentinel node biopsy. The accuracy of AUS was affected by metastatic size (OR 1.11), obesity (OR 2.46), histological grade (OR 4.43), and HER2-status (OR 3.66); metastatic size and histological grade were significant in the multivariate analysis. Conclusions The clinical utility of AUS in low-risk breast cancer deserves further evaluation as the accuracy decreased with a low nodal metastatic burden. The diagnostic performance is modified by tumor and clinical characteristics. Patients with nodal disease detected by AUS-FNAB represent a group for whom neoadjuvant therapy should be considered. PMID:27050668

Pressure-induced organic topological nodal-line semimetal in the three-dimensional molecular crystal Pd (dddt) 2

NASA Astrophysics Data System (ADS)

Liu, Zhao; Wang, Haidi; Wang, Z. F.; Yang, Jinlong; Liu, Feng

2018-04-01

The nodal-line semimetal represents a class of topological materials characterized with highest band degeneracy. It is usually found in inorganic materials of high crystal symmetry or a minimum symmetry of inversion aided with accidental band degeneracy [Phys. Rev. Lett. 118, 176402 (2017), 10.1103/PhysRevLett.118.176402]. Based on first-principles band structure, Wannier charge center, and topological surface state calculations, here we predict a pressure-induced topological nodal-line semimetal in the absence of spin-orbit coupling (SOC) in the synthesized single-component 3D molecular crystal Pd (dddt) 2 . We show a Γ -centered single nodal line undulating within a narrow energy window across the Fermi level. This intriguing nodal line is generated by pressure-induced accidental band degeneracy, without protection from any crystal symmetry. When SOC is included, the fourfold degenerated nodal line is gapped and Pd (dddt) 2 becomes a strong 3D topological metal with an Z2 index of (1;000). However, the tiny SOC gap makes it still possible to detect the nodal-line properties experimentally. Our findings afford an attractive route for designing and realizing topological states in 3D molecular crystals, as they are weakly bonded through van der Waals forces with a low crystal symmetry so that their electronic structures can be easily tuned by pressure.

Nodal lines and nodal loops in nonsymmorphic odd-parity superconductors

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

Micklitz, T.; Norman, M. R.

2017-01-01

We discuss the nodal structure of odd-parity superconductors in the presence of nonsymmorphic crystal symmetries, both with and without spin-orbit coupling, and with and without time-reversal symmetry. We comment on the relation of our work to previous work in the literature, and also the implications for unconventional superconductors such as UPt3.

DOUAR: A new three-dimensional creeping flow numerical model for the solution of geological problems

NASA Astrophysics Data System (ADS)

Braun, Jean; Thieulot, Cédric; Fullsack, Philippe; DeKool, Marthijn; Beaumont, Christopher; Huismans, Ritske

2008-12-01

We present a new finite element code for the solution of the Stokes and energy (or heat transport) equations that has been purposely designed to address crustal-scale to mantle-scale flow problems in three dimensions. Although it is based on an Eulerian description of deformation and flow, the code, which we named DOUAR ('Earth' in Breton language), has the ability to track interfaces and, in particular, the free surface, by using a dual representation based on a set of particles placed on the interface and the computation of a level set function on the nodes of the finite element grid, thus ensuring accuracy and efficiency. The code also makes use of a new method to compute the dynamic Delaunay triangulation connecting the particles based on non-Euclidian, curvilinear measure of distance, ensuring that the density of particles remains uniform and/or dynamically adapted to the curvature of the interface. The finite element discretization is based on a non-uniform, yet regular octree division of space within a unit cube that allows efficient adaptation of the finite element discretization, i.e. in regions of strong velocity gradient or high interface curvature. The finite elements are cubes (the leaves of the octree) in which a q1- p0 interpolation scheme is used. Nodal incompatibilities across faces separating elements of differing size are dealt with by introducing linear constraints among nodal degrees of freedom. Discontinuities in material properties across the interfaces are accommodated by the use of a novel method (which we called divFEM) to integrate the finite element equations in which the elemental volume is divided by a local octree to an appropriate depth (resolution). A variety of rheologies have been implemented including linear, non-linear and thermally activated creep and brittle (or plastic) frictional deformation. A simple smoothing operator has been defined to avoid checkerboard oscillations in pressure that tend to develop when using a highly irregular octree discretization and the tri-linear (or q1- p0) finite element. A three-dimensional cloud of particles is used to track material properties that depend on the integrated history of deformation (the integrated strain, for example); its density is variable and dynamically adapted to the computed flow. The large system of algebraic equations that results from the finite element discretization and linearization of the basic partial differential equations is solved using a multi-frontal massively parallel direct solver that can efficiently factorize poorly conditioned systems resulting from the highly non-linear rheology and the presence of the free surface. The code is almost entirely parallelized. We present example results including the onset of a Rayleigh-Taylor instability, the indentation of a rigid-plastic material and the formation of a fold beneath a free eroding surface, that demonstrate the accuracy, efficiency and appropriateness of the new code to solve complex geodynamical problems in three dimensions.

Age Related Changes in Topological Properties of Brain Functional Network and Structural Connectivity.

PubMed

Shah, Chandan; Liu, Jia; Lv, Peilin; Sun, Huaiqiang; Xiao, Yuan; Liu, Jieke; Zhao, Youjin; Zhang, Wenjing; Yao, Li; Gong, Qiyong; Lui, Su

2018-01-01

Introduction: There are still uncertainties about the true nature of age related changes in topological properties of the brain functional network and its structural connectivity during various developmental stages. In this cross- sectional study, we investigated the effects of age and its relationship with regional nodal properties of the functional brain network and white matter integrity. Method: DTI and fMRI data were acquired from 458 healthy Chinese participants ranging from age 8 to 81 years. Tractography was conducted on the DTI data using FSL. Graph Theory analyses were conducted on the functional data yielding topological properties of the functional network using SPM and GRETNA toolbox. Two multiple regressions were performed to investigate the effects of age on nodal topological properties of the functional brain network and white matter integrity. Result: For the functional studies, we observed that regional nodal characteristics such as node betweenness were decreased while node degree and node efficiency was increased in relation to increasing age. Perversely, we observed that the relationship between nodal topological properties and fasciculus structures were primarily positive for nodal betweenness but negative for nodal degree and nodal efficiency. Decrease in functional nodal betweenness was primarily located in superior frontal lobe, right occipital lobe and the global hubs. These brain regions also had both direct and indirect anatomical relationships with the 14 fiber bundles. A linear age related decreases in the Fractional anisotropy (FA) value was found in the callosum forceps minor. Conclusion: These results suggests that age related differences were more pronounced in the functional than in structural measure indicating these measures do not have direct one-to-one mapping. Our study also indicates that the fiber bundles with longer fibers exhibited a more pronounced effect on the properties of functional network.

Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma.

PubMed

Seol, Ki Ho; Lee, Jeong Eun

2016-03-01

To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4-72 Gy (39.6-45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC.

Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma

PubMed Central

Seol, Ki Ho

2016-01-01

Purpose To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Materials and Methods Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4–72 Gy (39.6–45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. Results The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. Conclusion No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC. PMID:27104162

Elective nodal irradiation (ENI) vs. involved field radiotherapy (IFRT) for locally advanced non-small cell lung cancer (NSCLC): A comparative analysis of toxicities and clinical outcomes.

PubMed

Fernandes, Annemarie T; Shen, Jason; Finlay, Jarod; Mitra, Nandita; Evans, Tracey; Stevenson, James; Langer, Corey; Lin, Lilie; Hahn, Stephen; Glatstein, Eli; Rengan, Ramesh

2010-05-01

Elective nodal irradiation (ENI) and involved field radiotherapy (IFRT) are definitive radiotherapeutic approaches used to treat patients with locally advanced non-small cell lung cancer (NSCLC). ENI delivers prophylactic radiation to clinically uninvolved lymph nodes, while IFRT only targets identifiable gross nodal disease. Because clinically uninvolved nodal stations may harbor microscopic disease, IFRT raises concerns for increased nodal failures. This retrospective cohort analysis evaluates failure rates and treatment-related toxicities in patients treated at a single institution with ENI and IFRT. We assessed all patients with stage III locally advanced or stage IV oligometastatic NSCLC treated with definitive radiotherapy from 2003 to 2008. Each physician consistently treated with either ENI or IFRT, based on their treatment philosophy. Of the 108 consecutive patients assessed (60 ENI vs. 48 IFRT), 10 patients had stage IV disease and 95 patients received chemotherapy. The median follow-up time for survivors was 18.9 months. On multivariable logistic regression analysis, patients treated with IFRT demonstrated a significantly lower risk of high grade esophagitis (Odds ratio: 0.31, p = 0.036). The differences in 2-year local control (39.2% vs. 59.6%), elective nodal control (84.3% vs. 84.3%), distant control (47.7% vs. 52.7%) and overall survival (40.1% vs. 43.7%) rates were not statistically significant between ENI vs. IFRT. Nodal failure rates in clinically uninvolved nodal stations were not increased with IFRT when compared to ENI. IFRT also resulted in significantly decreased esophageal toxicity, suggesting that IFRT may allow for integration of concurrent systemic chemotherapy in a greater proportion of patients. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Omitting elective nodal irradiation during thoracic irradiation in limited-stage small cell lung cancer--evidence from a phase II trial.

PubMed

Colaco, Rovel; Sheikh, Hamid; Lorigan, Paul; Blackhall, Fiona; Hulse, Paul; Califano, Raffaele; Ashcroft, Linda; Taylor, Paul; Thatcher, Nicholas; Faivre-Finn, Corinne

2012-04-01

Omitting elective nodal irradiation (ENI) in limited-stage disease small cell lung cancer (LD-SCLC) is expected to result in smaller radiation fields. We report on data from a randomised phase II trial that omitted ENI in patients receiving concurrent chemo-radiotherapy for LD-SCLC. 38 patients with LD-SCLC were randomised to receive once-daily (66 Gy in 33 fractions) or twice-daily (45 Gy in 30 fractions) radiotherapy (RT). 3D-conformal RT was given concurrently with cisplatin and etoposide starting with the second cycle of a total of four cycles. The gross tumour volume was defined as primary tumour with involved lymph nodes (nodes ≥1 cm in short axis) identifiable with CT imaging. ENI was not used. Six recurrence patterns were identified: recurrence within planning target volume (PTV) only, recurrence within PTV+regional nodal recurrence and/or distant recurrence, isolated nodal recurrence outside PTV, nodal recurrence outside PTV+distant recurrence, distant metastases only and no recurrence. At median follow-up 16.9 months, 31/38 patients were evaluable and 14/31 patients had relapsed. There were no isolated nodal recurrences. Eight patients relapsed with intra-thoracic disease: 2 within PTV only, 4 within PTV and distantly and 2 with nodal recurrence outside PTV plus distant metastases. Rates of grade 3+ acute oesophagitis and pneumonitis in the 31 evaluable patients were 23 and 3% respectively. In our study of LD-SCLC, omitting ENI based on CT imaging was not associated with a high risk of isolated nodal recurrence, although further prospective studies are needed to confirm this. Routine ENI omission will be further evaluated prospectively in the ongoing phase III CONVERT trial (NCT00433563). Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Toddler signaling regulates mesodermal cell migration downstream of Nodal signaling

PubMed Central

Norris, Megan L; Pauli, Andrea; Gagnon, James A; Lord, Nathan D; Rogers, Katherine W; Mosimann, Christian; Zon, Leonard I

2017-01-01

Toddler/Apela/Elabela is a conserved secreted peptide that regulates mesendoderm development during zebrafish gastrulation. Two non-exclusive models have been proposed to explain Toddler function. The ‘specification model’ postulates that Toddler signaling enhances Nodal signaling to properly specify endoderm, whereas the ‘migration model’ posits that Toddler signaling regulates mesendodermal cell migration downstream of Nodal signaling. Here, we test key predictions of both models. We find that in toddler mutants Nodal signaling is initially normal and increasing endoderm specification does not rescue mesendodermal cell migration. Mesodermal cell migration defects in toddler mutants result from a decrease in animal pole-directed migration and are independent of endoderm. Conversely, endodermal cell migration defects are dependent on a Cxcr4a-regulated tether of the endoderm to mesoderm. These results suggest that Toddler signaling regulates mesodermal cell migration downstream of Nodal signaling and indirectly affects endodermal cell migration via Cxcr4a-signaling. PMID:29117894

Hybrid nodal loop metal: Unconventional magnetoresponse and material realization

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Yu, Zhi-Ming; Lu, Yunhao; Sheng, Xian-Lei; Yang, Hui Ying; Yang, Shengyuan A.

2018-03-01

A nodal loop is formed by a band crossing along a one-dimensional closed manifold, with each point on the loop a linear nodal point in the transverse dimensions, and can be classified as type I or type II depending on the band dispersion. Here, we propose a class of nodal loops composed of both type-I and type-II points, which are hence termed as hybrid nodal loops. Based on first-principles calculations, we predict the realization of such loops in the existing electride material Ca2As . For a hybrid loop, the Fermi surface consists of coexisting electron and hole pockets that touch at isolated points for an extended range of Fermi energies, without the need for fine-tuning. This leads to unconventional magnetic responses, including the zero-field magnetic breakdown and the momentum-space Klein tunneling observable in the magnetic quantum oscillations, as well as the peculiar anisotropy in the cyclotron resonance.

Nodal patterning without Lefty inhibitory feedback is functional but fragile

PubMed Central

Gagnon, James A; Pauli, Andrea; Zimmerman, Steven; Aksel, Deniz C; Reyon, Deepak; Tsai, Shengdar Q; Joung, J Keith

2017-01-01

Developmental signaling pathways often activate their own inhibitors. Such inhibitory feedback has been suggested to restrict the spatial and temporal extent of signaling or mitigate signaling fluctuations, but these models are difficult to rigorously test. Here, we determine whether the ability of the mesendoderm inducer Nodal to activate its inhibitor Lefty is required for development. We find that zebrafish lefty mutants exhibit excess Nodal signaling and increased specification of mesendoderm, resulting in embryonic lethality. Strikingly, development can be fully restored without feedback: Lethal patterning defects in lefty mutants can be rescued by ectopic expression of lefty far from its normal expression domain or by spatially and temporally uniform exposure to a Nodal inhibitor drug. While drug-treated mutants are less tolerant of mild perturbations to Nodal signaling levels than wild type embryos, they can develop into healthy adults. These results indicate that patterning without inhibitory feedback is functional but fragile. PMID:29215332

Identification of lesion and nodal resistance in pea (Pisum sativum L.) to Sclerotinia sclerotiorum using genome-wide association studies and RNA-Seq

USDA-ARS?s Scientific Manuscript database

Nodal resistance in plants is a phenomenon where a fungal infection is prevented from passing through a node and the infection is limited to an internode region. Nodal resistance has been observed in some pathosystems such as the pea (Pisum sativum L.)-white mold (WM) (Sclerotinia sclerotiorum (Lib....

Brady's Geothermal Field - Map of DAS, Nodal, Vibroseis and Reftek Station Deployment

DOE Data Explorer

Kurt Feigl

2016-10-15

Map of DAS, nodal, vibroseis and Reftek stations during March 2016 deployment. The plot on the left has nodal stations labeled; the plot on the right has vibroseis observations labeled. Stations are shown in map-view using Brady's rotated X-Y coordinates with side plots denoting elevation with respect to the WGS84 ellipsoid. Blue circles denote vibroseis data, x symbols denote DAS (cyan for horizontal and magenta for vertical), black asterisks denote Reftek data, and red plus signs denote nodal data. This map can be found on UW-Madison's askja server at /PoroTomo/DATA/MAPS/Deployment_Stations.pdf

Integration of nodal and BMP signals in the heart requires FoxH1 to create left-right differences in cell migration rates that direct cardiac asymmetry.

PubMed

Lenhart, Kari F; Holtzman, Nathalia G; Williams, Jessica R; Burdine, Rebecca D

2013-01-01

Failure to properly establish the left-right (L/R) axis is a major cause of congenital heart defects in humans, but how L/R patterning of the embryo leads to asymmetric cardiac morphogenesis is still unclear. We find that asymmetric Nodal signaling on the left and Bmp signaling act in parallel to establish zebrafish cardiac laterality by modulating cell migration velocities across the L/R axis. Moreover, we demonstrate that Nodal plays the crucial role in generating asymmetry in the heart and that Bmp signaling via Bmp4 is dispensable in the presence of asymmetric Nodal signaling. In addition, we identify a previously unappreciated role for the Nodal-transcription factor FoxH1 in mediating cell responsiveness to Bmp, further linking the control of these two pathways in the heart. The interplay between these TGFβ pathways is complex, with Nodal signaling potentially acting to limit the response to Bmp pathway activation and the dosage of Bmp signals being critical to limit migration rates. These findings have implications for understanding the complex genetic interactions that lead to congenital heart disease in humans.

The Bmp signaling pathway regulates development of left-right asymmetry in amphioxus.

PubMed

Soukup, Vladimir; Kozmik, Zbynek

2018-02-01

Establishment of asymmetry along the left-right (LR) body axis in vertebrates requires interplay between Nodal and Bmp signaling pathways. In the basal chordate amphioxus, the left-sided activity of the Nodal signaling has been attributed to the asymmetric morphogenesis of paraxial structures and pharyngeal organs, however the role of Bmp signaling in LR asymmetry establishment has not been addressed to date. Here, we show that Bmp signaling is necessary for the development of LR asymmetric morphogenesis of amphioxus larvae through regulation of Nodal signaling. Loss of Bmp signaling results in loss of the left-sided expression of Nodal, Gdf1/3, Lefty and Pitx and in gain of ectopic expression of Cerberus on the left side. As a consequence, the larvae display loss of the offset arrangement of axial structures, loss of the left-sided pharyngeal organs including the mouth, and ectopic development of the right-sided organs on the left side. Bmp inhibition thus phenocopies inhibition of Nodal signaling and results in the right isomerism. We conclude that Bmp and Nodal pathways act in concert to specify the left side and that Bmp signaling plays a fundamental role during LR development in amphioxus. Copyright © 2017 Elsevier Inc. All rights reserved.

Improving the pathologic evaluation of lung cancer resection specimens.

PubMed

Osarogiagbon, Raymond U; Hilsenbeck, Holly L; Sales, Elizabeth W; Berry, Allen; Jarrett, Robert W; Giampapa, Christopher S; Finch-Cruz, Clara N; Spencer, David

2015-08-01

Accurate post-operative prognostication and management heavily depend on pathologic nodal stage. Patients with nodal metastasis benefit from post-operative adjuvant chemotherapy, those with mediastinal nodal involvement may also benefit from adjuvant radiation therapy. However, the quality of pathologic nodal staging varies significantly, with major survival implications in large populations of patients. We describe the quality gap in pathologic nodal staging, and provide evidence of its potential reversibility by targeted corrective interventions. One intervention, designed to improve the surgical lymphadenectomy, specimen labeling, and secure transfer between the operating theatre and the pathology laboratory, involves use of pre-labeled specimen collection kits. Another intervention involves application of an improved method of gross dissection of lung resection specimens, to reduce the inadvertent loss of intrapulmonary lymph nodes to histologic examination for metastasis. These corrective interventions are the subject of a regional dissemination and implementation project in diverse healthcare systems in a tri-state region of the United States with some of the highest lung cancer incidence and mortality rates. We discuss the potential of these interventions to significantly improve the accuracy of pathologic nodal staging, risk stratification, and the quality of specimens available for development of stage-independent prognostic markers in lung cancer.

The Shock and Vibration Bulletin. Part 2. Invited Papers, Structural Dynamics

DTIC Science & Technology

1974-08-01

VIKING LANDER DYNAMICS 41 Mr. Joseph C. Pohlen, Martin Marietta Aerospace, Denver, Colorado Structural Dynamics PERFORMANCE OF STATISTICAL ENERGY ANALYSIS 47...aerospace structures. Analytical prediction of these environments is beyond the current scope of classical modal techniques. Statistical energy analysis methods...have been developed that circumvent the difficulties of high-frequency nodal analysis. These statistical energy analysis methods are evaluated

Topological nodal superconducting phases and topological phase transition in the hyperhoneycomb lattice

NASA Astrophysics Data System (ADS)

Bouhon, Adrien; Schmidt, Johann; Black-Schaffer, Annica M.

2018-03-01

We establish the topology of the spin-singlet superconducting states in the bare hyperhoneycomb lattice, and we derive analytically the full phase diagram using only symmetry and topology in combination with simple energy arguments. The phase diagram is dominated by two states preserving time-reversal symmetry. We find a line-nodal state dominating at low doping levels that is topologically nontrivial and exhibits surface Majorana flatbands, which we show perfectly match the bulk-boundary correspondence using the Berry phase approach. At higher doping levels, we find a fully gapped state with trivial topology. By analytically calculating the topological invariant of the nodal lines, we derive the critical point between the line-nodal and fully gapped states as a function of both pairing parameters and doping. We find that the line-nodal state is favored not only at lower doping levels but also if symmetry-allowed deformations of the lattice are present. Adding simple energy arguments, we establish that a fully gapped state with broken time-reversal symmetry likely appears covering the actual phase transition. We find this fully gapped state to be topologically trivial, while we find an additional point-nodal state at very low doing levels that also break time-reversal symmetry and has nontrivial topology with associated Fermi surface arcs. We eventually address the robustness of the phase diagram to generalized models also including adiabatic spin-orbit coupling, and we show how all but the point-nodal state are reasonably stable.

Influence of FDG-PET on primary nodal target volume definition for head and neck carcinomas.

PubMed

van Egmond, Sylvia L; Piscaer, Vera; Janssen, Luuk M; Stegeman, Inge; Hobbelink, Monique G; Grolman, Wilko; Terhaard, Chris H

The role of 2-[ 18 F]-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in routine diagnostic staging remains controversial. In case of discordance between FDG-PET and CT, a compromise has to be made between the risk of false positive FDG-PET and the risk of delaying appropriate salvage intervention. Second, with intensity modulated radiation therapy (IMRT), smaller radiation fields allow tissue sparing, but could also lead to more marginal failures. We retrospectively studied 283 patients with head and neck carcinoma scheduled for radiotherapy between 2002 and 2010. We analyzed the influence of FDG-PET/CT versus CT alone on defining nodal target volume definition and evaluated its long-term clinical results. Second, the location of nodal recurrences was related to the radiation regional dose distribution. In 92 patients, CT and FDG-PET, performed in mold, showed discordant results. In 33%, nodal staging was altered by FDG-PET. In 24%, FDG-PET also led to an alteration in nodal treatment, including a nodal upstage of 18% and downstage of 6%. In eight of these 92 patients, a regional recurrence occurred. Only two patients had a recurrence in the discordant node on FDG-PET and CT and both received a boost (high dose radiation). These results support the complementary value of FDG-PET/CT compared to CT alone in defining nodal target volume definition for radiotherapy of head and neck cancer.

BMP inhibition by DAN in Hensen's node is a critical step for the establishment of left-right asymmetry in the chick embryo.

PubMed

Katsu, Kenjiro; Tokumori, Daisuke; Tatsumi, Norifumi; Suzuki, Atsushi; Yokouchi, Yuji

2012-03-01

During left-right (L-R) axis formation, Nodal is expressed in the node and has a central role in the transfer of L-R information in the vertebrate embryo. Bone morphogenetic protein (BMP) signaling also has an important role for maintenance of gene expression around the node. Several members of the Cerberus/Dan family act on L-R patterning by regulating activity of the transforming growth factor-β (TGF-β) family. We demonstrate here that chicken Dan plays a critical role in L-R axis formation. Chicken Dan is expressed in the left side of the node shortly after left-handed Shh expression and before the appearance of asymmetrically expressed genes in the lateral plate mesoderm (LPM). In vitro experiments revealed that DAN inhibited BMP signaling but not NODAL signaling. SHH had a positive regulatory effect on Dan expression while BMP4 had a negative effect. Using overexpression and RNA interference-mediated knockdown strategies, we demonstrate that Dan is indispensable for Nodal expression in the LPM and for Lefty-1 expression in the notochord. In the perinodal region, expression of Dan and Nodal was independent of each other. Nodal up-regulation by DAN required NODAL signaling, suggesting that DAN might act synergistically with NODAL. Our data indicate that Dan plays an essential role in the establishment of the L-R axis by inhibiting BMP signaling around the node. Copyright © 2012. Published by Elsevier Inc.

Spectroscopic imaging scanning tunneling microscopy of a Dirac line node material ZrSiS

NASA Astrophysics Data System (ADS)

Zhou, Lihui; He, Qingyu; Queiroz, Raquel; Grüneis, Andreas; Schnyder, Andreas; Ast, Christian; Schoop, Leslie; Takagi, Hide; Rost, Andreas

3D Dirac materials are an intensive area of current condensed matter research. The related Dirac line node materials have come into focus due to many shared properties such as unconventional magneto-transport and the potential to host topologically nontrivial phases. ZrSiS is one of the first discovered materials of this new family, hosting a nodal line and an unconventional surface state. Spectroscopic imaging scanning tunneling microscopy (SI-STM) detects quasiparticle interference and has been extensively used to study the scattering mechanism and the band structures of exotic materials with high energy resolution at the atomic scale. Here in this presentation, we report the investigation of ZrSiS by SI-STM at the atomic scale, in combination with DFT calculations. We succeeded in visualizing the Dirac nodal line both in real and momentum space, adding key pieces of evidences confirming the existence of a nodal line in this material and highlighting its exceptional properties. The breaking of a non-symmorphic symmetry at the surface induces an unusual surface state whose dispersion was mapped. In particular, we observed spectroscopic signatures of a type-II Dirac fermion hosted by the surface state. Our data as seen by SI-STM has impact beyond ZrSiS providing crucial insights into the properties of Dirac line node materials in particular and non-symmorphic crystals in general.

Maternal nodal and zebrafish embryogenesis.

PubMed

Bennett, James T; Stickney, Heather L; Choi, Wen-Yee; Ciruna, Brian; Talbot, William S; Schier, Alexander F

2007-11-08

In fish and amphibians, the dorsal axis is specified by the asymmetric localization of maternally provided components of the Wnt signalling pathway. Gore et al. suggest that the Nodal signal Squint (Sqt) is required as a maternally provided dorsal determinant in zebrafish. Here we test their proposal and show that the maternal activities of sqt and the related Nodal gene cyclops (cyc) are not required for dorsoventral patterning.

On the Nodal Lines of Eisenstein Series on Schottky Surfaces

NASA Astrophysics Data System (ADS)

Jakobson, Dmitry; Naud, Frédéric

2017-04-01

On convex co-compact hyperbolic surfaces {X=Γ backslash H2}, we investigate the behavior of nodal curves of real valued Eisenstein series {F_λ(z,ξ)}, where {λ} is the spectral parameter, {ξ} the direction at infinity. Eisenstein series are (non-{L^2}) eigenfunctions of the Laplacian {Δ_X} satisfying {Δ_X F_λ=(1/4+λ^2)F_λ}. As {λ} goes to infinity (the high energy limit), we show that, for generic {ξ}, the number of intersections of nodal lines with any compact segment of geodesic grows like {λ}, up to multiplicative constants. Applications to the number of nodal domains inside the convex core of the surface are then derived.

Winding numbers of nodal points in Fe-based superconductors

NASA Astrophysics Data System (ADS)

Chichinadze, Dmitry V.; Chubukov, Andrey V.

2018-03-01

We analyze the nodal points in multiorbital Fe-based superconductors from a topological perspective. We consider the s+- gap structure with accidental nodes, and the d -wave gap with nodes along the symmetry directions. In both cases, the nodal points can be moved by varying an external parameter, e.g., a degree of interpocket pairing. Eventually, the nodes merge and annihilate via a Lifshitz-type transition. We discuss the Lifshitz transition in Fe-based superconductors from a topological point of view. We show, both analytically and numerically, that the merging nodal points have winding numbers of opposite sign. This is consistent with the general reasoning that the total winding number is a conserved quantity in the Lifshitz transition.

Two highly-related regulatory subunits of PP2A exert opposite effects on TGF-β/Activin/Nodal signalling

PubMed Central

Batut, Julie; Schmierer, Bernhard; Cao, Jing; Raftery, Laurel A.; Hill, Caroline S.; Howell, Michael

2016-01-01

Summary We identify Bα (PPP2R2A) and Bδ (PPP2R2D), two highly-related members of the B family of regulatory subunits of the protein phosphatase PP2A, as important modulators of TGF-β/Activin/Nodal signalling, which affect the pathway in opposite ways. Knockdown of Bα in Xenopus embryos or mammalian tissue culture cells suppresses TGF-β/Activin/Nodal-dependent responses, whereas knockdown of Bδ enhances these responses. Moreover, in Drosophila, overexpression of Smad2 rescues a severe wing phenotype caused by overexpression of the single Drosophila PP2A B subunit, Twins. We show that in vertebrates Bα enhances TGF-β/Activin/Nodal signalling by stabilising the basal levels of type I receptor, whereas Bδ negatively modulates these pathways by restricting receptor activity. Thus, these highly-related members of the same subfamily of PP2A regulatory subunits differentially regulate TGF-β/Activin/Nodal signalling to elicit opposing biological outcomes. PMID:18697906

Barrier tunneling of the loop-nodal semimetal in the hyperhoneycomb lattice

NASA Astrophysics Data System (ADS)

Guan, Ji-Huan; Zhang, Yan-Yang; Lu, Wei-Er; Xia, Yang; Li, Shu-Shen

2018-05-01

We theoretically investigate the barrier tunneling in the 3D model of the hyperhoneycomb lattice, which is a nodal-line semimetal with a Dirac loop at zero energy. In the presence of a rectangular potential, the scattering amplitudes for different injecting states around the nodal loop are calculated, by using analytical treatments of the effective model, as well as numerical simulations of the tight binding model. In the low energy regime, states with remarkable transmissions are only concentrated in a small range around the loop plane. When the momentum of the injecting electron is coplanar with the nodal loop, nearly perfect transmissions can occur for a large range of injecting azimuthal angles if the potential is not high. For higher potential energies, the transmission shows a resonant oscillation with the potential, but still with peaks being perfect transmissions that do not decay with the potential width. These strikingly robust transports of the loop-nodal semimetal can be approximately explained by a momentum dependent Dirac Hamiltonian.

Comparison of Modal to Nodal Approaches for Wavefront Correction,

DTIC Science & Technology

1986-02-01

the influence function of the wavefront corrector. (Implicit here is the assumption that the influence function is the same for every node, which is...To implement a nodal correction, the wavefront to be corrected is -. .. decomposed using a basis which is determined by the nodal (actuator) influence ... function of the wavefront corrector. This decomposition results in a set of coefficients which correspond to the drive signal required at the

The distance between breast cancer and the skin is associated with axillary nodal metastasis.

PubMed

Eom, Yong Hwa; Kim, Eun Jin; Chae, Byung Joo; Song, Byung Joo; Jung, Sang Seol

2015-06-01

More superficially located tumors may be more likely than deeper tumors to metastasize to the axillary nodes via the lymphatics. The aim of this study was to determine whether breast cancer distance from the skin affects axillary node metastasis, ipsilateral breast cancer recurrence, or recurrence-free survival. A total of 1,005 consecutive patients with breast cancer who underwent surgery between January 2003 and December 2009 were selected. The distance of the tumor from the skin was measured from the skin to the most anterior hypoechoic leading edge of the lesion. In total, 603 (68%) patients had no axillary nodal metastasis, and 288 (32%) had axillary nodal metastasis. A breast cancer distance from the skin <3 mm induced more axillary nodal metastasis (P = 0.039). However, no significant correlation was observed between breast cancer distance from the skin <3 mm and ipsilateral breast cancer recurrence (P = 0.788) or recurrence-free survival (P = 0.353). Breast cancers located closer to the skin had a higher incidence of axillary nodal metastasis. Therefore, tumor distance from the skin should be considered when evaluating a patient with breast cancer and considering the risk of nodal metastasis. © 2015 Wiley Periodicals, Inc.

Role of Nodal-PITX2C signaling pathway in glucose-induced cardiomyocyte hypertrophy.

PubMed

Su, Dongmei; Jing, Sun; Guan, Lina; Li, Qian; Zhang, Huiling; Gao, Xiaobo; Ma, Xu

2014-06-01

Pathological cardiac hypertrophy is a major cause of morbidity and mortality in cardiovascular disease. Recent studies have shown that cardiomyocytes, in response to high glucose (HG) stimuli, undergo hypertrophic growth. While much work still needs to be done to elucidate this important mechanism of hypertrophy, previous works have showed that some pathways or genes play important roles in hypertrophy. In this study, we showed that sublethal concentrations of glucose (25 mmol/L) could induce cardiomyocyte hypertrophy with an increase in the cellular surface area and the upregulation of the atrial natriuretic peptide (ANP) gene, a hypertrophic marker. High glucose (HG) treatments resulted in the upregulation of the Nodal gene, which is under-expressed in cardiomyocytes. We also determined that the knockdown of the Nodal gene resisted HG-induced cardiomyocyte hypertrophy. The overexpression of Nodal was able to induce hypertrophy in cardiomyocytes, which was associated with the upregulation of the PITX2C gene. We also showed that increases in the PITX2C expression, in response to Nodal, were mediated by the Smad4 signaling pathway. This study is highly relevant to the understanding of the effects of the Nodal-PITX2C pathway on HG-induced cardiomyocyte hypertrophy, as well as the related molecular mechanisms.

Risk of isolated nodal failure for non-small cell lung cancer (NSCLC) treated with the elective nodal irradiation (ENI) using 3D-conformal radiotherapy (3D-CRT) techniques--a retrospective analysis.

PubMed

Kepka, Lucyna; Bujko, Krzysztof; Zolciak-Siwinska, Agnieszka

2008-01-01

To estimate retrospectively the rate of isolated nodal failures (INF) in NSCLC patients treated with the elective nodal irradiation (ENI) using 3D-conformal radiotherapy (3D-CRT). One hundred and eighty-five patients with I-IIIB stage treated with 3D-CRT in consecutive clinical trials differing in an extent of the ENI were analyzed. According to the extent of the ENI, two groups were distinguished: extended (n = 124) and limited (n = 61) ENI. INF was defined as regional nodal failure occurring without local progression. Cumulative Incidence of INF (CIINF) was evaluated by univariate and multivariate analysis with regard to prognostic factors. With a median follow up of 30 months, the two-year actuarial overall survival was 35%. The two-year CIINF rate was 12%. There were 16 (9%) INF, eight (6%) for extended and eight (13%) for limited ENI. In the univariate analysis bulky mediastinal disease (BMD), left side, higher N stage, and partial response to RT had a significant negative impact on the CIINF. BMD was the only independent predictor of the risk of incidence of the INF (p = 0.001). INF is more likely to occur in case of more advanced nodal status.

How do I deal with the axilla in patients with a positive sentinel lymph node?

PubMed

Falkson, Conrad B

2011-12-01

Optimal management of the axilla in a patient with a positive sentinel node biopsy is not yet defined.These patients usually have Breast Conserving Surgery and receive adjuvant systemic therapy and whole breast radiation.Treatment options for the axilla include: no further surgery with or without radiation completion axillary nodal dissection with or without radiation Radiation options in addition to whole breast radiation include axillary and supraclavicular nodal irradiation regional nodal irradiationincludes supraclavicular and internal mammary nodes Completion axillary dissection has been standard practice in patients with positive sentinel nodes. the number of involved nodes provides prognostic information. theoretically improves local control, but may be obviated by systemic chemotherapy. but avoidance of dissection may not adversely affect locoregional control or survival. dissection has significant morbidity so safe avoidance is desirable. There is little worldwide concordance on the use of radiation: whole breast radiation (commonly used after breast conserving surgery) may radiate the lower axilla supraclavicular radiation is most commonly recommended for patients with four or more nodes but may confer a survival benefit on patients with lower risk disease. adding nodal irradiation reduces local recurrence with only modest toxicity. Adjuvant systemic therapy provides a survival benefit for patients with nodal disease. Most will receive cytostatic chemotherapy containing an anthracycline and a taxane. Hormone therapy is appropriate for estrogen receptor positive disease. The extent to which systemic therapy controls microscopic nodal disease is unknown. Node positive patients should generally receive adjuvant chemotherapy.A small group of patients benefit from specific nodal therapy. Further studies are needed to better identify these patients.

Assessment of Ultrasound Features Predicting Axillary Nodal Metastasis in Breast Cancer: The Impact of Cortical Thickness

PubMed Central

Stachs, A.; Thi, A. Tra-Ha; Dieterich, M.; Stubert, J.; Hartmann, S.; Glass, Ä.; Reimer, T.; Gerber, B.

2015-01-01

Purpose: To evaluate the accuracy of axillary ultrasound (AUS) in detecting nodal metastasis in patients with early-stage breast cancer and to identify AUS features with high predictive power. Materials and Methods: Prospective single-center preliminary study in 105 patients with a primary diagnosis of breast cancer and clinically negative axilla. AUS was performed using a 12 MHz linear-array transducer before ultrasound-guided needle biopsy. Nodal characteristics (shape, longitudinal-transverse [LT] axis ratio, margins, cortical thickness, hyperechoic hilum) were correlated with histopathological nodal status after SLNB or axillary lymph node dissection (ALND). Results: Nodal metastases were present in 42/105 patients (40.0%). Univariate analyses showed that absence of hyperechoic hilum, round shape, LT axis ratio<2, sharp margins and cortical thickness>3 mm were associated with lymph node metastasis. Multivariate logistic regression analysis revealed cortical thickness > 3 mm as an independent predictive parameter for nodal involvement. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 66.7, 74.6, 63.6, 77.0% and 71.4% respectively when cortical thickness > 3 mm was applied as the criterion for AUS positivity. Axillary tumor volume was low in patients with pT1/2 tumors and negative AUS, since only 3.2% of patients had > 2 metastatic lymph nodes. Conclusion: Cortical thickness>3 mm is a reliable predictor of nodal metastatic involvement. Negative AUS does not exclude lymph node metastases, but extensive axillary tumor volume is rare. PMID:27689144

Developmental changes in electrophysiological characteristics of human induced Pluripotent Stem Cell-derived cardiomyocytes

PubMed Central

Ben-Ari, Meital; Naor, Shulamit; Zeevi-Levin, Naama; Schick, Revital; Ben Jehuda, Ronen; Reiter, Irina; Raveh, Amit; Grijnevitch, Inna; Barak, Omri; Rosen, Michael R.; Weissman, Amir; Binah, Ofer

2016-01-01

Background Previous studies proposed that throughout differentiation of human induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs) only 3 types of action potentials (AP) exist: nodal, atrial and ventricular-like. Objective To investigate whether there are precisely 3 phenotypes or a continuum exists among them, we tested 2 hypotheses: (1) during culture development a cardiac precursor cell is present that - depending on age - can evolve into the 3 phenotypes. (2) The predominant pattern is early prevalence of nodal phenotype, transient appearance of atrial phenotype, evolution to ventricular phenotype, and persistence of transitional phenotypes. Methods To test these hypotheses we: (1) performed FACS analysis of nodal, atrial and ventricular markers; (2) recorded AP from 280 7-to-95 day old iPSC-CMs; (3) analyzed AP characteristics. Results The major findings were: (1) FACS analysis of 30 and 60-day old cultures showed that an iPSC-CMs population shifts from nodal into atrial/ventricular phenotype, while including significant transitional populations.(2) The AP population did not consist of 3 distinct phenotypes; (3) Culture aging was associated with a shift from nodal to ventricular dominance, with a transient (57–70 days) appearance of atrial phenotype; (4) Beat Rate Variability was more prominent in nodal than ventricular cardiomyocytes while If density increased in older cultures. Conclusions From the onset of development the iPSC-CMs population includes nodal, atrial and ventricular AP and a broad spectrum of transitional phenotypes. The most readily distinguishable phenotype is atrial which appears only transiently, yet dominates at 57–70 days of evolution. PMID:27639456

The Accuracy of Integrated [18F] Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Detection of Pelvic and Para-aortic Nodal Metastasis in Patients with High Risk Endometrial Cancer

PubMed Central

Gholkar, Nikhil Shirish; Saha, Subhas Chandra; Prasad, GRV; Bhattacharya, Anish; Srinivasan, Radhika; Suri, Vanita

2014-01-01

Lymph nodal (LN) metastasis is the most important prognostic factor in high-risk endometrial cancer. However, the benefit of routine lymphadenectomy in endometrial cancer is controversial. This study was conducted to assess the accuracy of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography ([18F] FDG-PET/CT) in detection of pelvic and para-aortic nodal metastases in high-risk endometrial cancer. 20 patients with high-risk endometrial carcinoma underwent [18F] FDG-PET/CT followed by total abdominal hysterectomy, bilateral salpingo-oophorectomy and systematic pelvic lymphadenectomy with or without para-aortic lymphadenectomy. The findings on histopathology were compared with [18F] FDG-PET/CT findings to calculate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [18F] FDG-PET/CT. The pelvic nodal findings were analyzed on a patient and nodal chain based criteria. The para-aortic nodal findings were reported separately. Histopathology documented nodal involvement in two patients (10%). For detection of pelvic nodes, on a patient based analysis, [18F] FDG-PET/CT had a sensitivity of 100%, specificity of 61.11%, PPV of 22.22%, NPV of 100% and accuracy of 65% and on a nodal chain based analysis, [18F] FDG-PET/CT had a sensitivity of 100%, specificity of 80%, PPV of 20%, NPV of 100%, and accuracy of 80.95%. For detection of para-aortic nodes, [18F] FDG-PET/CT had sensitivity of 100%, specificity of 66.67%, PPV of 20%, NPV of 100%, and accuracy of 69.23%. Although [18F] FDG-PET/CT has high sensitivity for detection of LN metastasis in endometrial carcinoma, it had moderate accuracy and high false positivity. However, the high NPV is important in selecting patients in whom lymphadenectomy may be omitted. PMID:25538488

Development of a phenotyping platform for high throughput screening of nodal root angle in sorghum.

PubMed

Joshi, Dinesh C; Singh, Vijaya; Hunt, Colleen; Mace, Emma; van Oosterom, Erik; Sulman, Richard; Jordan, David; Hammer, Graeme

2017-01-01

In sorghum, the growth angle of nodal roots is a major component of root system architecture. It strongly influences the spatial distribution of roots of mature plants in the soil profile, which can impact drought adaptation. However, selection for nodal root angle in sorghum breeding programs has been restricted by the absence of a suitable high throughput phenotyping platform. The aim of this study was to develop a phenotyping platform for the rapid, non-destructive and digital measurement of nodal root angle of sorghum at the seedling stage. The phenotyping platform comprises of 500 soil filled root chambers (50 × 45 × 0.3 cm in size), made of transparent perspex sheets that were placed in metal tubs and covered with polycarbonate sheets. Around 3 weeks after sowing, once the first flush of nodal roots was visible, roots were imaged in situ using an imaging box that included two digital cameras that were remotely controlled by two android tablets. Free software ( openGelPhoto.tcl ) allowed precise measurement of nodal root angle from the digital images. The reliability and efficiency of the platform was evaluated by screening a large nested association mapping population of sorghum and a set of hybrids in six independent experimental runs that included up to 500 plants each. The platform revealed extensive genetic variation and high heritability (repeatability) for nodal root angle. High genetic correlations and consistent ranking of genotypes across experimental runs confirmed the reproducibility of the platform. This low cost, high throughput root phenotyping platform requires no sophisticated equipment, is adaptable to most glasshouse environments and is well suited to dissect the genetic control of nodal root angle of sorghum. The platform is suitable for use in sorghum breeding programs aiming to improve drought adaptation through root system architecture manipulation.

Nodal Stage of Surgically Resected Non-Small Cell Lung Cancer and Its Effect on Recurrence Patterns and Overall Survival

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

Varlotto, John M., E-mail: john.varlotto@umassmemorial.org; Yao, Aaron N.; DeCamp, Malcolm M.

Purpose: Current National Comprehensive Cancer Network guidelines recommend postoperative radiation therapy (PORT) for patients with resected non-small cell lung cancer (NSCLC) with N2 involvement. We investigated the relationship between nodal stage and local-regional recurrence (LR), distant recurrence (DR) and overall survival (OS) for patients having an R0 resection. Methods and Materials: A multi-institutional database of consecutive patients undergoing R0 resection for stage I-IIIA NSCLC from 1995 to 2008 was used. Patients receiving any radiation therapy before relapse were excluded. A total of 1241, 202, and 125 patients were identified with N0, N1, and N2 involvement, respectively; 161 patients received chemotherapy.more » Cumulative incidence rates were calculated for LR and DR as first sites of failure, and Kaplan-Meier estimates were made for OS. Competing risk analysis and proportional hazards models were used to examine LR, DR, and OS. Independent variables included age, sex, surgical procedure, extent of lymph node sampling, histology, lymphatic or vascular invasion, tumor size, tumor grade, chemotherapy, nodal stage, and visceral pleural invasion. Results: The median follow-up time was 28.7 months. Patients with N1 or N2 nodal stage had rates of LR similar to those of patients with N0 disease, but were at significantly increased risk for both DR (N1, hazard ratio [HR] = 1.84, 95% confidence interval [CI]: 1.30-2.59; P=.001; N2, HR = 2.32, 95% CI: 1.55-3.48; P<.001) and death (N1, HR = 1.46, 95% CI: 1.18-1.81; P<.001; N2, HR = 2.33, 95% CI: 1.78-3.04; P<.001). LR was associated with squamous histology, visceral pleural involvement, tumor size, age, wedge resection, and segmentectomy. The most frequent site of LR was the mediastinum. Conclusions: Our investigation demonstrated that nodal stage is directly associated with DR and OS but not with LR. Thus, even some patients with, N0-N1 disease are at relatively high risk of local recurrence. Prospective identification of risk factors for local recurrence may aid in selecting an appropriate population for further study of postoperative radiation therapy.« less

Toxicity and quality of life after choline-PET/CT directed salvage lymph node dissection and adjuvant radiotherapy in nodal recurrent prostate cancer.

PubMed

Jilg, Cordula A; Leifert, Anja; Schnell, Daniel; Kirste, Simon; Volegova-Neher, Natalia; Schlager, Daniel; Wieser, Gesche; Henne, Karl; Schultze-Seemann, Wolfgang; Grosu, Anca-L; Rischke, Hans Christian

2014-08-12

In a previous study we demonstrated that, based on 11C/18 F-choline positron emission tomography-computerized-tomography as a diagnostic tool, salvage lymph node dissection (LND) plus adjuvant radiotherapy (ART) is feasible for treatment of pelvic/retroperitoneal nodal recurrence of prostate cancer (PCa). However, the toxicity of this combined treatment strategy has not been systematically investigated before. The aim of the current study was to evaluate the acute and late toxicity and quality of life of ART after LND in pelvic/retroperitoneal nodal recurrent PCa. 43 patients with nodal recurrent PCa were treated with 46 LND followed by ART (mean 49.6 Gy total dose) at the sites of nodal recurrence. Toxicity of ART was analysed by physically examination (31/43, 72.1%), by requesting 15 frequent items of adverse events from the Common-Terminology-Criteria for Adverse Events Version 4.0-catalogue and by review of medical records. QLQ-C30 (EORTC quality of life assessment) and PR25 (prostate cancer module) questionnaires were used to investigate quality of life. Toxicity was evaluated before starting of ART, during ART (acute toxicity), after ART (mean 2.3 months) and at end of follow up (mean 3.2 years after end of ART) reflecting late toxicity. 71.7% (33/46) of 46 ART were treatment of pelvic, 10.9% (5/46) of retroperitoneal only and 28.3% (13/46) of pelvic and retroperitoneal regions. Overall 52 symptoms representing toxicities were observed before ART, 107 during ART, 88 after end of ART and 52 at latest follow up. Leading toxicities during ART were diarrhoea (19%, 20/107), urinary incontinence (16%, 17/107) and fatigue (16%, 17/107). The spectrum of late toxicities was almost equal to those before beginning of ART. No grade 3 adverse events or chronic lymphedema at extremities were observed. We observed no clear correlation between localisation of treated regions, technique of ART and frequency or severity of toxicities. Mean quality of life at final evaluation was 74%. ART after extended LND in PCa relapse is justifiable with respect to adverse effects and toxicity. The side effects were circumscribed and well tolerated. The spectrum of adverse events at latest follow up was almost equal to those before start of ART.

Sensitive molecular detection of small nodal metastasis in uterine cervical cancer using HPV16-E6/CK19/MUC1 cancer biomarkers

PubMed Central

Samouëlian, Vanessa; Mechtouf, Nawel; Leblanc, Eric; Cardin, Guillaume B.; Lhotellier, Valérie; Querleu, Denis; Révillion, Françoise; Rodier, Francis

2018-01-01

Metastatic nodal involvement is a critical prognostic factor in uterine cervical cancer (UCC). To improve current methods of detecting UCC metastases in lymph nodes (LNs), we used quantitative PCR (qPCR) to assess mRNA expression of potential metastatic biomarkers. We found that expression of HPV16-E6, cytokeratin19 (CK19), and mucin1 (MUC1) is consistently upregulated in tumors and metastatic tissues, supporting a role for these genes in UCC progression. These putative biomarkers were able to predict the presence of histologically positive metastatic LNs with respective sensitivities and specificities of 82% and 99% (CK19), 76% and 95% (HPV16-E6), and 76% and 78% (MUC1). While the biomarkers failed to detect 1.7% to 2.2% of the histologically positive LNs when used individually, combining CK19 and HPV16-E6 enhanced sensitivity and specificity to 100% and 94%, respectively. To explore the sensitivity of qPCR-based detection of varying proportions of invading HPV16-positive UCC cells, we designed a LN metastasis model that achieved a fresh cell detection limit of 0.008% (1:12500 HPV16-positive to HPV16-negative cells), and a paraffin-embedded, formalin-fixed (PEFF) detection limit of 0.02% (1:5000 HPV16-positive to HPV16-negative cells), both of which are within the theoretical detection limit for micrometastasis. Thus, HPV E6/E7 oncogenes may be useful targets for the ultrasensitive detection of nodal involvements like micrometastases in fresh or archived tissue samples. Moreover, our results suggest that the biomarker combination of CK19/HPV-E6 could support a real-time intraoperative strategy for the detection of small, but potentially lethal, metastatic nodal involvements in fresh UCC tissues. PMID:29774091

Prognostic value of site-specific metastases in pancreatic adenocarcinoma: A Surveillance Epidemiology and End Results database analysis.

PubMed

Oweira, Hani; Petrausch, Ulf; Helbling, Daniel; Schmidt, Jan; Mannhart, Meinrad; Mehrabi, Arianeb; Schöb, Othmar; Giryes, Anwar; Decker, Michael; Abdel-Rahman, Omar

2017-03-14

To evaluate the prognostic value of site-specific metastases among patients with metastatic pancreatic carcinoma registered within the Surveillance, Epidemiology and End Results (SEER) database. SEER database (2010-2013) has been queried through SEER*Stat program to determine the presentation, treatment outcomes and prognostic outcomes of metastatic pancreatic adenocarcinoma according to the site of metastasis. In this study, metastatic pancreatic adenocarcinoma patients were classified according to the site of metastases (liver, lung, bone, brain and distant lymph nodes). We utilized chi-square test to compare the clinicopathological characteristics among different sites of metastases. We used Kaplan-Meier analysis and log-rank testing for survival comparisons. We employed Cox proportional model to perform multivariate analyses of the patient population; and accordingly hazard ratios with corresponding 95%CI were generated. Statistical significance was considered if a two-tailed P value < 0.05 was achieved. A total of 13233 patients with stage IV pancreatic cancer and known sites of distant metastases were identified in the period from 2010-2013 and they were included into the current analysis. Patients with isolated distant nodal involvement or lung metastases have better overall and pancreatic cancer-specific survival compared to patients with isolated liver metastases (for overall survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001) (for pancreatic cancer-specific survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001). Multivariate analysis revealed that age < 65 years, white race, being married, female gender; surgery to the primary tumor and surgery to the metastatic disease were associated with better overall survival and pancreatic cancer-specific survival. Pancreatic adenocarcinoma patients with isolated liver metastases have worse outcomes compared to patients with isolated lung or distant nodal metastases. Further research is needed to identify the highly selected subset of patients who may benefit from local treatment of the primary tumor and/or metastatic disease.

An Interesting Case of Retropharyngeal Lymph Nodal Metastases in a Case of Iodine-Refractory Thyroid Cancer.

PubMed

Harisankar, Chidambaram Natrajan Balasubramanian; Vijayabhaskar, Ramakrishnan

2018-01-01

Metastases to cervical lymph node are fairly common in differentiated thyroid cancer. In iodine-refractory disease, the disease may persist in the thyroid bed, cervical lymph nodes, lungs, or the bones commonly. Retropharyngeal lymph nodal involvement in thyroid cancer is unusual and may even be the presenting complaint. We represent a case of iodine-refractory thyroid cancer with retropharyngeal lymph nodal involvement in addition to lung metastases.

EGF-CFC proteins are essential coreceptors for the TGF-β signals Vg1 and GDF1

PubMed Central

Cheng, Simon K.; Olale, Felix; Bennett, James T.; Brivanlou, Ali H.; Schier, Alexander F.

2003-01-01

The TGF-β signals Nodal, Activin, GDF1, and Vg1 have been implicated in mesoderm induction and left-right patterning. Nodal and Activin both activate Activin receptors, but only Nodal requires EGF-CFC coreceptors for signaling. We report that Vg1 and GDF1 signaling in zebrafish also depends on EGF-CFC proteins, but not on Nodal signals. Correspondingly, we find that in Xenopus Vg1 and GDF1 bind to and signal through Activin receptors only in the presence of EGF-CFC proteins. These results establish that multiple TGF-β signals converge on Activin receptor/EGF-CFC complexes and suggest a more widespread requirement for coreceptors in TGF-β signaling than anticipated previously. PMID:12514096

MAGNETIC END CLOSURES FOR PLASMA CONFINING AND HEATING DEVICES

DOEpatents

Post, R.F.

1963-08-20

More effective magnetic closure field regions for various open-ended containment magnetic fields used in fusion reactor devices are provided by several spaced, coaxially-aligned solenoids utilized to produce a series of nodal field regions of uniform or, preferably, of incrementally increasing intensity separated by lower intensity regions outwardly from the ends of said containment zone. Plasma sources may also be provided to inject plasma into said lower intensity areas to increase plasma density therein. Plasma may then be transported, by plasma diffusion mechanisms provided by the nodal fields, into the containment field. With correlated plasma densities and nodal field spacings approximating the mean free partl cle collision path length in the zones between the nodal fields, optimum closure effectiveness is obtained. (AEC)

A penalty-based nodal discontinuous Galerkin method for spontaneous rupture dynamics

NASA Astrophysics Data System (ADS)

Ye, R.; De Hoop, M. V.; Kumar, K.

2017-12-01

Numerical simulation of the dynamic rupture processes with slip is critical to understand the earthquake source process and the generation of ground motions. However, it can be challenging due to the nonlinear friction laws interacting with seismicity, coupled with the discontinuous boundary conditions across the rupture plane. In practice, the inhomogeneities in topography, fault geometry, elastic parameters and permiability add extra complexity. We develop a nodal discontinuous Galerkin method to simulate seismic wave phenomenon with slipping boundary conditions, including the fluid-solid boundaries and ruptures. By introducing a novel penalty flux, we avoid solving Riemann problems on interfaces, which makes our method capable for general anisotropic and poro-elastic materials. Based on unstructured tetrahedral meshes in 3D, the code can capture various geometries in geological model, and use polynomial expansion to achieve high-order accuracy. We consider the rate and state friction law, in the spontaneous rupture dynamics, as part of a nonlinear transmitting boundary condition, which is weakly enforced across the fault surface as numerical flux. An iterative coupling scheme is developed based on implicit time stepping, containing a constrained optimization process that accounts for the nonlinear part. To validate the method, we proof the convergence of the coupled system with error estimates. We test our algorithm on a well-established numerical example (TPV102) of the SCEC/USGS Spontaneous Rupture Code Verification Project, and benchmark with the simulation of PyLith and SPECFEM3D with agreeable results.

The Maternal Maverick/GDF15-like TGF-β Ligand Panda Directs Dorsal-Ventral Axis Formation by Restricting Nodal Expression in the Sea Urchin Embryo.

PubMed

Haillot, Emmanuel; Molina, Maria Dolores; Lapraz, François; Lepage, Thierry

2015-01-01

Specification of the dorsal-ventral axis in the highly regulative sea urchin embryo critically relies on the zygotic expression of nodal, but whether maternal factors provide the initial spatial cue to orient this axis is not known. Although redox gradients have been proposed to entrain the dorsal-ventral axis by acting upstream of nodal, manipulating the activity of redox gradients only has modest consequences, suggesting that other factors are responsible for orienting nodal expression and defining the dorsal-ventral axis. Here we uncover the function of Panda, a maternally provided transforming growth factor beta (TGF-β) ligand that requires the activin receptor-like kinases (Alk) Alk3/6 and Alk1/2 receptors to break the radial symmetry of the embryo and orient the dorsal-ventral axis by restricting nodal expression. We found that the double inhibition of the bone morphogenetic protein (BMP) type I receptors Alk3/6 and Alk1/2 causes a phenotype dramatically more severe than the BMP2/4 loss-of-function phenotype, leading to extreme ventralization of the embryo through massive ectopic expression of nodal, suggesting that an unidentified signal acting through BMP type I receptors cooperates with BMP2/4 to restrict nodal expression. We identified this ligand as the product of maternal Panda mRNA. Double inactivation of panda and bmp2/4 led to extreme ventralization, mimicking the phenotype caused by inactivation of the two BMP receptors. Inhibition of maternal panda mRNA translation disrupted the early spatial restriction of nodal, leading to persistent massive ectopic expression of nodal on the dorsal side despite the presence of Lefty. Phylogenetic analysis indicates that Panda is not a prototypical BMP ligand but a member of a subfamily of TGF-β distantly related to Inhibins, Lefty, and TGF-β that includes Maverick from Drosophila and GDF15 from vertebrates. Indeed, overexpression of Panda does not appear to directly or strongly activate phosphoSmad1/5/8 signaling, suggesting that although this TGF-β may require Alk1/2 and/or Alk3/6 to antagonize nodal expression, it may do so by sequestering a factor essential for Nodal signaling, by activating a non-Smad pathway downstream of the type I receptors, or by activating extremely low levels of pSmad1/5/8. We provide evidence that, although panda mRNA is broadly distributed in the early embryo, local expression of panda mRNA efficiently orients the dorsal-ventral axis and that Panda activity is required locally in the early embryo to specify this axis. Taken together, these findings demonstrate that maternal panda mRNA is both necessary and sufficient to orient the dorsal-ventral axis. These results therefore provide evidence that in the highly regulative sea urchin embryo, the activity of spatially restricted maternal factors regulates patterning along the dorsal-ventral axis.

The Maternal Maverick/GDF15-like TGF-β Ligand Panda Directs Dorsal-Ventral Axis Formation by Restricting Nodal Expression in the Sea Urchin Embryo

PubMed Central

Haillot, Emmanuel; Molina, Maria Dolores; Lapraz, François; Lepage, Thierry

2015-01-01

Specification of the dorsal-ventral axis in the highly regulative sea urchin embryo critically relies on the zygotic expression of nodal, but whether maternal factors provide the initial spatial cue to orient this axis is not known. Although redox gradients have been proposed to entrain the dorsal-ventral axis by acting upstream of nodal, manipulating the activity of redox gradients only has modest consequences, suggesting that other factors are responsible for orienting nodal expression and defining the dorsal-ventral axis. Here we uncover the function of Panda, a maternally provided transforming growth factor beta (TGF-β) ligand that requires the activin receptor-like kinases (Alk) Alk3/6 and Alk1/2 receptors to break the radial symmetry of the embryo and orient the dorsal-ventral axis by restricting nodal expression. We found that the double inhibition of the bone morphogenetic protein (BMP) type I receptors Alk3/6 and Alk1/2 causes a phenotype dramatically more severe than the BMP2/4 loss-of-function phenotype, leading to extreme ventralization of the embryo through massive ectopic expression of nodal, suggesting that an unidentified signal acting through BMP type I receptors cooperates with BMP2/4 to restrict nodal expression. We identified this ligand as the product of maternal Panda mRNA. Double inactivation of panda and bmp2/4 led to extreme ventralization, mimicking the phenotype caused by inactivation of the two BMP receptors. Inhibition of maternal panda mRNA translation disrupted the early spatial restriction of nodal, leading to persistent massive ectopic expression of nodal on the dorsal side despite the presence of Lefty. Phylogenetic analysis indicates that Panda is not a prototypical BMP ligand but a member of a subfamily of TGF-β distantly related to Inhibins, Lefty, and TGF-β that includes Maverick from Drosophila and GDF15 from vertebrates. Indeed, overexpression of Panda does not appear to directly or strongly activate phosphoSmad1/5/8 signaling, suggesting that although this TGF-β may require Alk1/2 and/or Alk3/6 to antagonize nodal expression, it may do so by sequestering a factor essential for Nodal signaling, by activating a non-Smad pathway downstream of the type I receptors, or by activating extremely low levels of pSmad1/5/8. We provide evidence that, although panda mRNA is broadly distributed in the early embryo, local expression of panda mRNA efficiently orients the dorsal-ventral axis and that Panda activity is required locally in the early embryo to specify this axis. Taken together, these findings demonstrate that maternal panda mRNA is both necessary and sufficient to orient the dorsal-ventral axis. These results therefore provide evidence that in the highly regulative sea urchin embryo, the activity of spatially restricted maternal factors regulates patterning along the dorsal-ventral axis. PMID:26352141

Robust doubly charged nodal lines and nodal surfaces in centrosymmetric systems

NASA Astrophysics Data System (ADS)

Bzdušek, Tomáš; Sigrist, Manfred

2017-10-01

Weyl points in three spatial dimensions are characterized by a Z -valued charge—the Chern number—which makes them stable against a wide range of perturbations. A set of Weyl points can mutually annihilate only if their net charge vanishes, a property we refer to as robustness. While nodal loops are usually not robust in this sense, it has recently been shown using homotopy arguments that in the centrosymmetric extension of the AI symmetry class they nevertheless develop a Z2 charge analogous to the Chern number. Nodal loops carrying a nontrivial value of this Z2 charge are robust, i.e., they can be gapped out only by a pairwise annihilation and not on their own. As this is an additional charge independent of the Berry π -phase flowing along the band degeneracy, such nodal loops are, in fact, doubly charged. In this manuscript, we generalize the homotopy discussion to the centrosymmetric extensions of all Atland-Zirnbauer classes. We develop a tailored mathematical framework dubbed the AZ +I classification and show that in three spatial dimensions such robust and multiply charged nodes appear in four of such centrosymmetric extensions, namely, AZ +I classes CI and AI lead to doubly charged nodal lines, while D and BDI support doubly charged nodal surfaces. We remark that no further crystalline symmetries apart from the spatial inversion are necessary for their stability. We provide a description of the corresponding topological charges, and develop simple tight-binding models of various semimetallic and superconducting phases that exhibit these nodes. We also indicate how the concept of robust and multiply charged nodes generalizes to other spatial dimensions.

A predictive index of axillary nodal involvement in operable breast cancer.

PubMed Central

De Laurentiis, M.; Gallo, C.; De Placido, S.; Perrone, F.; Pettinato, G.; Petrella, G.; Carlomagno, C.; Panico, L.; Delrio, P.; Bianco, A. R.

1996-01-01

We investigated the association between pathological characteristics of primary breast cancer and degree of axillary nodal involvement and obtained a predictive index of the latter from the former. In 2076 cases, 17 histological features, including primary tumour and local invasion variables, were recorded. The whole sample was randomly split in a training (75% of cases) and a test sample. Simple and multiple correspondence analysis were used to select the variables to enter in a multinomial logit model to build an index predictive of the degree of nodal involvement. The response variable was axillary nodal status coded in four classes (N0, N1-3, N4-9, N > or = 10). The predictive index was then evaluated by testing goodness-of-fit and classification accuracy. Covariates significantly associated with nodal status were tumour size (P < 0.0001), tumour type (P < 0.0001), type of border (P = 0.048), multicentricity (P = 0.003), invasion of lymphatic and blood vessels (P < 0.0001) and nipple invasion (P = 0.006). Goodness-of-fit was validated by high concordance between observed and expected number of cases in each decile of predicted probability in both training and test samples. Classification accuracy analysis showed that true node-positive cases were well recognised (84.5%), but there was no clear distinction among the classes of node-positive cases. However, 10 year survival analysis showed a superimposible prognostic behaviour between predicted and observed nodal classes. Moreover, misclassified node-negative patients (i.e. those who are predicted positive) showed an outcome closer to patients with 1-3 metastatic nodes than to node-negative ones. In conclusion, the index cannot completely substitute for axillary node information, but it is a predictor of prognosis as accurate as nodal involvement and identifies a subgroup of node-negative patients with unfavourable prognosis. PMID:8630286

Delineation of Supraclavicular Target Volumes in Breast Cancer Radiation Therapy

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

Brown, Lindsay C.; Diehn, Felix E.; Boughey, Judy C.

Purpose: To map the location of gross supraclavicular metastases in patients with breast cancer, in order to determine areas at highest risk of harboring subclinical disease. Methods and Materials: Patients with axial imaging of gross supraclavicular disease were identified from an institutional breast cancer registry. Locations of the metastatic lymph nodes were transferred onto representative axial computed tomography images of the supraclavicular region and compared with the Radiation Therapy Oncology Group (RTOG) breast cancer atlas for radiation therapy planning. Results: Sixty-two patients with 161 supraclavicular nodal metastases were eligible for study inclusion. At the time of diagnosis, 117 nodal metastasesmore » were present in 44 patients. Forty-four nodal metastases in 18 patients were detected at disease recurrence, 4 of whom had received prior radiation to the supraclavicular fossa. Of the 161 nodal metastases, 95 (59%) were within the RTOG consensus volume, 4 nodal metastases (2%) in 3 patients were marginally within the volume, and 62 nodal metastases (39%) in 30 patients were outside the volume. Supraclavicular disease outside the RTOG consensus volume was located in 3 regions: at the level of the cricoid and thyroid cartilage (superior to the RTOG volume), in the posterolateral supraclavicular fossa (posterolateral to the RTOG volume), and in the lateral low supraclavicular fossa (lateral to the RTOG volume). Only women with multiple supraclavicular metastases had nodal disease that extended superiorly to the level of the thyroid cartilage. Conclusions: For women with risk of harboring subclinical supraclavicular disease warranting the addition of supraclavicular radiation, coverage of the posterior triangle and the lateral low supraclavicular region should be considered. For women with known supraclavicular disease, extension of neck coverage superior to the cricoid cartilage may be warranted.« less

Atlas-Based Segmentation Improves Consistency and Decreases Time Required for Contouring Postoperative Endometrial Cancer Nodal Volumes

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

Young, Amy V.; Department of Radiation Oncology, St. Luke's-Roosevelt Hospital, New York, NY; Wortham, Angela

2011-03-01

Purpose: Accurate target delineation of the nodal volumes is essential for three-dimensional conformal and intensity-modulated radiotherapy planning for endometrial cancer adjuvant therapy. We hypothesized that atlas-based segmentation ('autocontouring') would lead to time savings and more consistent contours among physicians. Methods and Materials: A reference anatomy atlas was constructed using the data from 15 postoperative endometrial cancer patients by contouring the pelvic nodal clinical target volume on the simulation computed tomography scan according to the Radiation Therapy Oncology Group 0418 trial using commercially available software. On the simulation computed tomography scans from 10 additional endometrial cancer patients, the nodal clinical targetmore » volume autocontours were generated. Three radiation oncologists corrected the autocontours and delineated the manual nodal contours under timed conditions while unaware of the other contours. The time difference was determined, and the overlap of the contours was calculated using Dice's coefficient. Results: For all physicians, manual contouring of the pelvic nodal target volumes and editing the autocontours required a mean {+-} standard deviation of 32 {+-} 9 vs. 23 {+-} 7 minutes, respectively (p = .000001), a 26% time savings. For each physician, the time required to delineate the manual contours vs. correcting the autocontours was 30 {+-} 3 vs. 21 {+-} 5 min (p = .003), 39 {+-} 12 vs. 30 {+-} 5 min (p = .055), and 29 {+-} 5 vs. 20 {+-} 5 min (p = .0002). The mean overlap increased from manual contouring (0.77) to correcting the autocontours (0.79; p = .038). Conclusion: The results of our study have shown that autocontouring leads to increased consistency and time savings when contouring the nodal target volumes for adjuvant treatment of endometrial cancer, although the autocontours still required careful editing to ensure that the lymph nodes at risk of recurrence are properly included in the target volume.« less

Nodal network generator for CAVE3

NASA Technical Reports Server (NTRS)

Palmieri, J. V.; Rathjen, K. A.

1982-01-01

A new extension of CAVE3 code was developed that automates the creation of a finite difference math model in digital form ready for input to the CAVE3 code. The new software, Nodal Network Generator, is broken into two segments. One segment generates the model geometry using a Tektronix Tablet Digitizer and the other generates the actual finite difference model and allows for graphic verification using Tektronix 4014 Graphic Scope. Use of the Nodal Network Generator is described.

Counting nodal domains on surfaces of revolution

NASA Astrophysics Data System (ADS)

Karageorge, Panos D.; Smilansky, Uzy

2008-05-01

We consider eigenfunctions of the Laplace-Beltrami operator on special surfaces of revolution. For this separable system, the nodal domains of the (real) eigenfunctions form a checkerboard pattern, and their number νn is proportional to the product of the angular and the 'surface' quantum numbers. Arranging the wavefunctions by increasing values of the Laplace-Beltrami spectrum, we obtain the nodal sequence, whose statistical properties we study. In particular, we investigate the distribution of the normalized counts \\frac{\

Tumor microvessel density–associated mast cells in canine nodal lymphoma

PubMed Central

Mann, Elizabeth; Whittington, Lisa

2014-01-01

Objective: Mast cells are associated in angiogenesis in various human and animal neoplasms. However, association of mast cells with tumor microvessel density in canine lymphoma was not previously documented. The objective of the study is to determine if mast cells are increased in canine nodal lymphomas and to evaluate their correlation with tumor microvessel density and grading of lymphomas. Methods: Nodal lymphomas from 33 dogs were studied and compared with nonneoplastic lymph nodes from 6 dogs as control. Mast cell count was made on Toluidine blue stained sections. Immunohistochemistry using antibody against Factor VIII was employed to visualize and determine microvessel density. Results: The mast cell count in lymphoma (2.95 ± 2.4) was significantly higher (p < 0.05) than that in the control (0.83 ± 0.3) and was positively correlated with tumor microvessel density (r = 0.44, p = 0.009). Significant difference was not observed in mast cell count and tumor microvessel density among different gradings of lymphomas. Conclusions: Mast cells are associated with tumor microvessel density in canine nodal lymphoma with no significant difference among gradings of lymphomas. Mast cells may play an important role in development of canine nodal lymphomas. Further detailed investigation on the role of mast cells as important part of tumor microenvironment in canine nodal lymphomas is recommended. PMID:26770752

Implications of inaccurate clinical nodal staging in pancreatic adenocarcinoma.

PubMed

Swords, Douglas S; Firpo, Matthew A; Johnson, Kirsten M; Boucher, Kenneth M; Scaife, Courtney L; Mulvihill, Sean J

2017-07-01

Many patients with stage I-II pancreatic adenocarcinoma do not undergo resection. We hypothesized that (1) clinical staging underestimates nodal involvement, causing stage IIB to have a greater percent of resected patients and (2) this stage-shift causes discrepancies in observed survival. The Surveillance, Epidemiology, and End Results (SEER) research database was used to evaluate cause-specific survival in patients with pancreatic adenocarcinoma from 2004-2012. Survival was compared using the log-rank test. Single-center data on 105 patients who underwent resection of pancreatic adenocarcinoma without neoadjuvant treatment were used to compare clinical and pathologic nodal staging. In SEER data, medium-term survival in stage IIB was superior to IB and IIA, with median cause-specific survival of 14, 9, and 11 months, respectively (P < .001). Seventy-two percent of stage IIB patients underwent resection vs 28% in IB and 36% in IIA (P < .001). In our institutional data, 12.4% of patients had clinical evidence of nodal involvement vs 69.5% by pathologic staging (P < .001). Among clinical stage IA-IIA patients, 71.6% had nodal involvement by pathologic staging. Both SEER and institutional data support substantial underestimation of nodal involvement by clinical staging. This finding has implications in decisions regarding neoadjuvant therapy and analysis of outcomes in the absence of pathologic staging. Copyright © 2017 Elsevier Inc. All rights reserved.

Quality assessment of lymph node sampling in rhabdomyosarcoma: A surveillance, epidemiology, and end results (SEER) program study.

PubMed

Lobeck, Inna; Dupree, Phylicia; Karns, Rebekah; Rodeberg, David; von Allmen, Daniel; Dasgupta, Roshni

2017-04-01

Lymph node sampling is integral in the management of extremity and paratesticular rhabdomyosarcoma (RMS). The aim of this study was to determine overall surgical compliance with treatment protocols and impact of nodal sampling outcomes in these tumors. A query of the surveillance, epidemiology, and end results program (SEER) database was performed from 2003 to 2008 for patients <19years of age with RMS. Data obtained included demographics, five-year survival and rate of nodal sampling. Analysis was performed utilizing chi-squared, Kaplan-Meier and hazard ratio modeling. Of 537 patients with extremity RMS, nodal sampling was performed in 25.7% (n=138). This lack of nodal sampling had a negative outcome on survival (p=0.004). Sixty five patients with paratesticular RMS aged greater than 10 were identified and also displayed low rates of lymph node sampling (47.7%, n=31). For paratesticular patients, a similar increase in survival was seen in patients who underwent nodal evaluation (p=0.024). Lymph node sampling is the standard of care in RMS. However, surgical compliance with treatment protocols is poor. Nodal evaluation correlated significantly with overall survival. These findings suggest a need for improved education among surgeons and oncologists regarding the need lymph node assessment in pediatric oncology patients. Evidence rating/classification: Prognosis study, Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

Value of an old school approach: safety and long-term success of radiofrequency current catheter ablation of atrioventricular nodal reentrant tachycardia in children and young adolescents.

PubMed

Siebels, Henrike; Sohns, Christian; Nürnberg, Jan-Hendrik; Siebels, Jürgen; Langes, Klaus; Hebe, Joachim

2018-05-15

Radiofrequency current energy (RFC) ablation is still considered as the gold standard for atrioventricular nodal reentrant tachycardia (AVNRT). Success-rates for AVNRT ablation vary irrespective of the ablation technology and strategy. This study aimed to access safety, efficacy, and long-term outcome of RFC catheter ablation for the treatment of AVNRT in children and adolescents aged < 19 years with special focus on modulation versus ablation of the AV nodal slow pathway (SP). A total number of 1143 patients (pts) < 19 years were referred for invasive electrophysiological testing due to paroxysmal supraventricular tachycardia (SVT). Diagnosis of AVNRT was confirmed in 412 pts, and RFC-guided ablation was attempted in 386 pts (age 13.0 ± 3.5 years). No permanent complications were observed. RFC application resulted in SP-ablation in 171/386 (44.3%) and in SP modulation in 208/386 (53.9%) children, whereas attempts for RFC treatment failed in 7 pts. Follow-up was completed for 396/412 patients (96.1%). Within a mean follow-up period of 54.9 ± 39.7 months, in 51/379 pts (13.5%) AVNRT recurrence was observed. The median time until tachycardia recurrence was 19.5 months. No difference for AVNRT recurrence was found comparing SP ablation versus SP modulation (p > 0.05), whereas the recurrence rate was significantly higher in patients with non-inducible SVT and therefore empiric SP treatment as compared to patients with inducible AVNRT (p = 0.01). RFC-guided ablation for AVNRT in children and adolescents is safe and leads to an acceptable long-term freedom from recurrences. SP modulation and SP ablation resulted in comparable acute and long-term success rates. Late AVNRT recurrences can occur even after years of freedom from tachycardia-related symptoms.

Linear network representation of multistate models of transport.

PubMed Central

Sandblom, J; Ring, A; Eisenman, G

1982-01-01

By introducing external driving forces in rate-theory models of transport we show how the Eyring rate equations can be transformed into Ohm's law with potentials that obey Kirchhoff's second law. From such a formalism the state diagram of a multioccupancy multicomponent system can be directly converted into linear network with resistors connecting nodal (branch) points and with capacitances connecting each nodal point with a reference point. The external forces appear as emf or current generators in the network. This theory allows the algebraic methods of linear network theory to be used in solving the flux equations for multistate models and is particularly useful for making proper simplifying approximation in models of complex membrane structure. Some general properties of linear network representation are also deduced. It is shown, for instance, that Maxwell's reciprocity relationships of linear networks lead directly to Onsager's relationships in the near equilibrium region. Finally, as an example of the procedure, the equivalent circuit method is used to solve the equations for a few transport models. PMID:7093425

Origin of chaos near three-dimensional quantum vortices: A general Bohmian theory

NASA Astrophysics Data System (ADS)

Tzemos, Athanasios C.; Efthymiopoulos, Christos; Contopoulos, George

2018-04-01

We provide a general theory for the structure of the quantum flow near three-dimensional (3D) nodal lines, i.e., one-dimensional loci where the 3D wave function becomes equal to zero. In suitably defined coordinates (comoving with the nodal line) the generic structure of the flow implies the formation of 3D quantum vortices. We show that such vortices are accompanied by nearby invariant lines of the comoving quantum flow, called X lines, which are normally hyperbolic. Furthermore, the stable and unstable manifolds of the X lines produce chaotic scatterings of nearby quantum (Bohmian) trajectories, thus inducing an intricate form of the quantum current in the neighborhood of each 3D quantum vortex. Generic formulas describing the structure around 3D quantum vortices are provided, applicable to an arbitrary choice of 3D wave function. We also give specific numerical examples as well as a discussion of the physical consequences of chaos near 3D quantum vortices.

Origin of chaos near three-dimensional quantum vortices: A general Bohmian theory.

PubMed

Tzemos, Athanasios C; Efthymiopoulos, Christos; Contopoulos, George

2018-04-01

We provide a general theory for the structure of the quantum flow near three-dimensional (3D) nodal lines, i.e., one-dimensional loci where the 3D wave function becomes equal to zero. In suitably defined coordinates (comoving with the nodal line) the generic structure of the flow implies the formation of 3D quantum vortices. We show that such vortices are accompanied by nearby invariant lines of the comoving quantum flow, called X lines, which are normally hyperbolic. Furthermore, the stable and unstable manifolds of the X lines produce chaotic scatterings of nearby quantum (Bohmian) trajectories, thus inducing an intricate form of the quantum current in the neighborhood of each 3D quantum vortex. Generic formulas describing the structure around 3D quantum vortices are provided, applicable to an arbitrary choice of 3D wave function. We also give specific numerical examples as well as a discussion of the physical consequences of chaos near 3D quantum vortices.

Encapsulation of nodal cuttings and shoot tips for storage and exchange of cassava germplasm.

PubMed

Danso, K E; Ford-Lloyd, B V

2003-04-01

We report the encapsulation of in vitro-derived nodal cuttings or shoot tips of cassava in 3% calcium alginate for storage and germplasm exchange purposes. Shoot regrowth was not significantly affected by the concentration of sucrose in the alginate matrix while root formation was. In contrast, increasing the sucrose concentration in the calcium chloride polymerisation medium significantly reduced regrowth from encapsulated nodal cuttings of accession TME 60444. Supplementing the alginate matrix with increased concentrations of 6-benzylaminopurine and alpha-naphthaleneacetic acid enhanced complete plant regrowth within 2 weeks. Furthermore, plant regrowth by encapsulated nodal cuttings and shoot tips was significantly affected by the duration of the storage period as shoot recovery decreased from almost 100% to 73.3% for encapsulated nodal cuttings and 94.4% to 60% for shoot tips after 28 days of storage. The high frequency of plant regrowth from alginate-coated micropropagules coupled with high viability percentage after 28 days of storage is highly encouraging for the exchange of cassava genetic resources. Such encapsulated micropropagules could be used as an alternative to synthetic seeds derived from somatic embryos.

Metabolic Syndrome Remodels Electrical Activity of the Sinoatrial Node and Produces Arrhythmias in Rats

PubMed Central

Albarado-Ibañez, Alondra; Avelino-Cruz, José Everardo; Velasco, Myrian; Torres-Jácome, Julián; Hiriart, Marcia

2013-01-01

In the last ten years, the incidences of metabolic syndrome and supraventricular arrhythmias have greatly increased. The metabolic syndrome is a cluster of alterations, which include obesity, hypertension, hypertriglyceridemia, glucose intolerance and insulin resistance, that increase the risk of developing, among others, atrial and nodal arrhythmias. The aim of this study is to demonstrate that metabolic syndrome induces electrical remodeling of the sinus node and produces arrhythmias. We induced metabolic syndrome in 2-month-old male Wistar rats by administering 20% sucrose in the drinking water. Eight weeks later, the rats were anesthetized and the electrocardiogram was recorded, revealing the presence of arrhythmias only in treated rats. Using conventional microelectrode and voltage clamp techniques, we analyzed the electrical activity of the sinoatrial node. We observed that in the sinoatrial node of “metabolic syndrome rats”, compared to controls, the spontaneous firing of all cells decreased, while the slope of the diastolic depolarization increased only in latent pacemaker cells. Accordingly, the pacemaker currents If and Ist increased. Furthermore, histological analysis showed a large amount of fat surrounding nodal cardiomyocytes and a rise in the sympathetic innervation. Finally, Poincaré plot denoted irregularity in the R-R and P-P ECG intervals, in agreement with the variability of nodal firing potential recorded in metabolic syndrome rats. We conclude that metabolic syndrome produces a dysfunction SA node by disrupting normal architecture and the electrical activity, which could explain the onset of arrhythmias in rats. PMID:24250786

Abnormal brain white matter network in young smokers: a graph theory analysis study.

PubMed

Zhang, Yajuan; Li, Min; Wang, Ruonan; Bi, Yanzhi; Li, Yangding; Yi, Zhang; Liu, Jixin; Yu, Dahua; Yuan, Kai

2018-04-01

Previous diffusion tensor imaging (DTI) studies had investigated the white matter (WM) integrity abnormalities in some specific fiber bundles in smokers. However, little is known about the changes in topological organization of WM structural network in young smokers. In current study, we acquired DTI datasets from 58 male young smokers and 51 matched nonsmokers and constructed the WM networks by the deterministic fiber tracking approach. Graph theoretical analysis was used to compare the topological parameters of WM network (global and nodal) and the inter-regional fractional anisotropy (FA) weighted WM connections between groups. The results demonstrated that both young smokers and nonsmokers had small-world topology in WM network. Further analysis revealed that the young smokers exhibited the abnormal topological organization, i.e., increased network strength, global efficiency, and decreased shortest path length. In addition, the increased nodal efficiency predominately was located in frontal cortex, striatum and anterior cingulate gyrus (ACG) in smokers. Moreover, based on network-based statistic (NBS) approach, the significant increased FA-weighted WM connections were mainly found in the PFC, ACG and supplementary motor area (SMA) regions. Meanwhile, the network parameters were correlated with the nicotine dependence severity (FTND) scores, and the nodal efficiency of orbitofrontal cortex was positive correlation with the cigarette per day (CPD) in young smokers. We revealed the abnormal topological organization of WM network in young smokers, which may improve our understanding of the neural mechanism of young smokers form WM topological organization level.

Metabolic syndrome remodels electrical activity of the sinoatrial node and produces arrhythmias in rats.

PubMed

Albarado-Ibañez, Alondra; Avelino-Cruz, José Everardo; Velasco, Myrian; Torres-Jácome, Julián; Hiriart, Marcia

2013-01-01

In the last ten years, the incidences of metabolic syndrome and supraventricular arrhythmias have greatly increased. The metabolic syndrome is a cluster of alterations, which include obesity, hypertension, hypertriglyceridemia, glucose intolerance and insulin resistance, that increase the risk of developing, among others, atrial and nodal arrhythmias. The aim of this study is to demonstrate that metabolic syndrome induces electrical remodeling of the sinus node and produces arrhythmias. We induced metabolic syndrome in 2-month-old male Wistar rats by administering 20% sucrose in the drinking water. Eight weeks later, the rats were anesthetized and the electrocardiogram was recorded, revealing the presence of arrhythmias only in treated rats. Using conventional microelectrode and voltage clamp techniques, we analyzed the electrical activity of the sinoatrial node. We observed that in the sinoatrial node of "metabolic syndrome rats", compared to controls, the spontaneous firing of all cells decreased, while the slope of the diastolic depolarization increased only in latent pacemaker cells. Accordingly, the pacemaker currents If and Ist increased. Furthermore, histological analysis showed a large amount of fat surrounding nodal cardiomyocytes and a rise in the sympathetic innervation. Finally, Poincaré plot denoted irregularity in the R-R and P-P ECG intervals, in agreement with the variability of nodal firing potential recorded in metabolic syndrome rats. We conclude that metabolic syndrome produces a dysfunction SA node by disrupting normal architecture and the electrical activity, which could explain the onset of arrhythmias in rats.

RW Per - Nodal motion changes its amplitude by 1.4 mag

NASA Technical Reports Server (NTRS)

Schaefer, Bradley E.; Fried, Robert E.

1991-01-01

RW Per was found to have large secular changes in its eclipse amplitude. In blue light, for example, the amplitude was 3.2 mag in the early 1900s, 2.2 mag in the late 1960s, and 1.75 mag in 1990. Throughout this time, the brightness at maximum was constant in all colors. It is shown that the only possible explanation is nodal motion, where the inclination varies with a period of roughly 100,000 yr. The nodal motion is caused by a third star, for which the light curve, the colors, and the O - C curve already provide evidence. Thus, RW Per is only the fourth known star with large changes of eclipse amplitude and is only the second example of nodal motion.

On Formulations of Discontinuous Galerkin and Related Methods for Conservation Laws

NASA Technical Reports Server (NTRS)

Huynh, H. T.

2014-01-01

A formulation for the discontinuous Galerkin (DG) method that leads to solutions using the differential form of the equation (as opposed to the standard integral form) is presented. The formulation includes (a) a derivative calculation that involves only data within each cell with no data interaction among cells, and (b) for each cell, corrections to this derivative that deal with the jumps in fluxes at the cell boundaries and allow data across cells to interact. The derivative with no interaction is obtained by a projection, but for nodal-type methods, evaluating this derivative by interpolation at the nodal points is more economical. The corrections are derived using the approximate (Dirac) delta functions. The formulation results in a family of schemes: different approximate delta functions give rise to different methods. It is shown that the current formulation is essentially equivalent to the flux reconstruction (FR) formulation. Due to the use of approximate delta functions, an energy stability proof simpler than that of Vincent, Castonguay, and Jameson (2011) for a family of schemes is derived. Accuracy and stability of resulting schemes are discussed via Fourier analyses. Similar to FR, the current formulation provides a unifying framework for high-order methods by recovering the DG, spectral difference (SD), and spectral volume (SV) schemes. It also yields stable, accurate, and economical methods.

Optimized planning methodologies of ASON implementation

NASA Astrophysics Data System (ADS)

Zhou, Michael M.; Tamil, Lakshman S.

2005-02-01

Advanced network planning concerns effective network-resource allocation for dynamic and open business environment. Planning methodologies of ASON implementation based on qualitative analysis and mathematical modeling are presented in this paper. The methodology includes method of rationalizing technology and architecture, building network and nodal models, and developing dynamic programming for multi-period deployment. The multi-layered nodal architecture proposed here can accommodate various nodal configurations for a multi-plane optical network and the network modeling presented here computes the required network elements for optimizing resource allocation.

Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity

NASA Astrophysics Data System (ADS)

Kim, Duk Y.; Lin, Shi-Zeng; Weickert, Franziska; Bauer, Eric D.; Ronning, Filip; Thompson, Joe D.; Movshovich, Roman

Unconventional superconductor CeCoIn5 orders magnetically in a spin-density-wave (SDW) in the low-temperature and high-field corner of the superconducting phase. Recent neutron scattering experiment revealed that the single-domain SDW's ordering vector Q depends strongly on the direction of the magnetic field, switching sharply as the field is rotated through the anti-nodal direction. This switching may be manifestation of a pair-density-wave (PDW) p-wave order parameter, which develops in addition to the well-established d-wave order parameter due to the SDW formation. We have investigated the hypersensitivity of the magnetic domain with a thermal conductivity measurement. The heat current (J) was applied along the [110] direction such that the Q vector is either perpendicular or parallel to J, depending on the magnetic field direction. A discontinuous change of the thermal conductivity was observed when the magnetic field is rotated around the [100] direction within 0 . 2° . The thermal conductivity with the Q parallel to the heat current (J ∥Q) is approximately 15% lager than that with the Q perpendicular to the heat current (J ⊥Q). This result is consistent with additional gapping of the nodal quasiparticle by the p-wave PDW coupled to SDW. Work at Los Alamos was performed under the auspices of the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering.

The Impact of the Size of Nodal Metastases on Recurrence Risk in Breast Cancer Patients With 1-3 Positive Axillary Nodes After Mastectomy

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

Harris, Eleanor E.R., E-mail: Eleanor.harris@moffitt.org; Freilich, Jessica; Lin, Hui-Yi

Purpose: Use of postmastectomy radiation therapy (PMRT) in breast cancer patients with 1-3 positive nodes is controversial. The objective of this study was to determine whether the size of nodal metastases in this subset could predict who would benefit from PMRT. Methods and Materials: We analyzed 250 breast cancer patients with 1-3 positive nodes after mastectomy treated with contemporary surgery and systemic therapy at our institution. Of these patients, 204 did not receive PMRT and 46 did receive PMRT. Local and regional recurrence risks were stratified by the size of the largest nodal metastasis measured as less than or equalmore » to 5 mm or greater than 5 mm. Results: The median follow-up was 65.6 months. In the whole group, regional recurrences occurred in 2% of patients in whom the largest nodal metastasis measured 5 mm or less vs 6% for those with metastases measuring greater than 5 mm. For non-irradiated patients only, regional recurrence rates were 2% and 9%, respectively. Those with a maximal nodal size greater than 5 mm had a significantly higher cumulative incidence of regional recurrence (P=.013). The 5-year cumulative incidence of a regional recurrence in the non-irradiated group was 2.7% (95% confidence interval [CI], 0.7%-7.2%) for maximal metastasis size of 5 mm or less, 6.9% (95% CI, 1.7%-17.3%) for metastasis size greater than 5 mm, and 16% (95% CI, 3.4%-36.8%) for metastasis size greater than 10 mm. The impact of the maximal nodal size on regional recurrences became insignificant in the multivariable model. Conclusions: In patients with 1-3 positive lymph nodes undergoing mastectomy without radiation, nodal metastasis greater than 5 mm was associated with regional recurrence after mastectomy, but its effect was modified by other factors (such as tumor stage). The size of the largest nodal metastasis may be useful to identify high-risk patients who may benefit from radiation therapy after mastectomy.« less

Association of Nodal Metastasis and Mortality With Vermilion vs Cutaneous Lip Location in Cutaneous Squamous Cell Carcinoma of the Lip.

PubMed

Wang, David M; Kraft, Stefan; Rohani, Pooyan; Murphy, George F; Besaw, Robert J; Karia, Pritesh S; Morgan, Frederick C; Schmults, Chrysalyne D

2018-06-01

Although the lip is considered a high-risk location in cutaneous squamous cell carcinoma (cSCC), it has not been established whether this risk stems from vermilion or cutaneous locations or both. To compare differences in risks of recurrence, metastasis, and death from cSCCs on the vermilion vs cutaneous lip. Retrospective cohort study of 303 patients with 310 primary cSCCs of the lip (138 cutaneous, 172 vermilion) diagnosed between 2000 and 2015 at 2 academic tertiary care centers in Boston, Massachusetts. Development of local recurrence, nodal metastasis, distant metastasis, disease-specific death, and all-cause death. Of the 303 study participants with 310 SCCs of the lip, 153 (50.5%) were men, and 150 (49.5%) were women; median age at diagnosis, 68 years (range, 27-93 years). Outcomes were as follows for vermilion vs cutaneous locations: local recurrence, 6.4% (11 of 172) vs 2.9% (4 of 138); nodal metastasis, 7.6% (13 of 172) vs 1.5% (2 of 138); distant metastasis, 0.6% (1 of 172) vs 0.7% (1 of 138); disease-specific death, 3.5% (6 of 172) vs 2.9% (4 of 138); and all-cause death, 26.7% (46 of 172) vs 29.0% (40 of 138). The difference was statistically significant for nodal metastasis (P = .01). In multivariable analysis, nodal metastasis was associated with vermilion lip location (subhazard ratio, 5.0; 95% CI, 1.1-23.8) and invasion beyond fat (fascia or beyond for vermilion lip) (subhazard ratio, 4.4; 95% CI, 1.3-14.9). The risk of nodal metastasis is 5-fold greater for cSCCs on the vermilion lip compared with those on the cutaneous lip. Squamous cell carcinomas of the cutaneous lip have a nodal metastasis risk similar to cSCCs in general (1.5%). Thus, vermilion involvement appears responsible for the increased risk associated with cSCC of lip. Vermilion involvement may merit radiologic nodal staging and inclusion in future tumor staging, since it was independently associated with higher-risk cSCC of the lip region.

Lefty Blocks a Subset of TGFβ Signals by Antagonizing EGF-CFC Coreceptors

PubMed Central

Cheng, Simon K; Olale, Felix; Brivanlou, Ali H

2004-01-01

Members of the EGF-CFC family play essential roles in embryonic development and have been implicated in tumorigenesis. The TGFβ signals Nodal and Vg1/GDF1, but not Activin, require EGF-CFC coreceptors to activate Activin receptors. We report that the TGFβ signaling antagonist Lefty also acts through an EGF-CFC-dependent mechanism. Lefty inhibits Nodal and Vg1 signaling, but not Activin signaling. Lefty genetically interacts with EGF-CFC proteins and competes with Nodal for binding to these coreceptors. Chimeras between Activin and Nodal or Vg1 identify a 14 amino acid region that confers independence from EGF-CFC coreceptors and resistance to Lefty. These results indicate that coreceptors are targets for both TGFβ agonists and antagonists and suggest that subtle sequence variations in TGFβ signals result in greater ligand diversity. PMID:14966532

Neurula rotation determines left-right asymmetry in ascidian tadpole larvae.

PubMed

Nishide, Kazuhiko; Mugitani, Michio; Kumano, Gaku; Nishida, Hiroki

2012-04-01

Tadpole larvae of the ascidian Halocynthia roretzi show morphological left-right asymmetry. The tail invariably bends towards the left side within the vitelline membrane. The structure of the larval brain is remarkably asymmetric. nodal, a conserved gene that shows left-sided expression, is also expressed on the left side in H. roretzi but in the epidermis unlike in vertebrates. We show that nodal signaling at the late neurula stage is required for stereotypic morphological left-right asymmetry at later stages. We uncover a novel mechanism to break embryonic symmetry, in which rotation of whole embryos provides the initial cue for left-sided expression of nodal. Two hours prior to the onset of nodal expression, the neurula embryo rotates along the anterior-posterior axis in a counterclockwise direction when seen in posterior view, and then this rotation stops when the left side of the embryo is oriented downwards. It is likely that epidermis monocilia, which appear at the neurula rotation stage, generate the driving force for the rotation. When the embryo lies on the left side, protrusion of the neural fold physically prevents it from rotating further. Experiments in which neurula rotation is perturbed by various means, including centrifugation and sandwiching between glass, indicate that contact of the left epidermis with the vitelline membrane as a consequence of neurula rotation promotes nodal expression in the left epidermis. We suggest that chemical, and not mechanical, signals from the vitelline membrane promote nodal expression. Neurula rotation is also conserved in other ascidian species.

[Clinical application of positron-emission tomography for the identification of cervical nodal metastases of head and neck cancer compared with CT or MRI and clinical palpation].

PubMed

Chen, Zhong-Wei; Zhu, Li-Jun; Hou, Qing-Yi; Wang, Qi-Peng; Jiang, Sui; Feng, Hang

2008-12-01

To evaluate the value of positron-emission tomography (PET) for the identification of cervical nodal metastases of head and neck cancer compared with CT/MRI and clinical palpation. Forty patients of head and neck cancer underwent PET and CT/MRI examination 2 weeks before surgery. PET, CT/MRI and clinical palpation were interpreted separately to assess regional lymph node status. Histopathologic analysis was used as the gold standard for assessment of the lymph node involvement. Differences in sensitivity, specificity and accuracy among the imaging modalities and clinical palpation were analyzed. The sensitivity of PET for the identification of nodal metastases was 14.3% higher than that of CT/MRI (P = 0.648) and 14.3% higher than that of clinical palpation (P = 0.648), whereas the specificity of PET was 15.4% higher than that of CT/MRI (P = 0.188) and 7.7% higher than that of clinical palpation (P = 0.482). The accuracy of 18F-FDG PET, CT/MRI, and clinical palpation for the identification of cervical nodal metastases was 85.0%, 70.0% and 75.0% respectively. The sensitivity, specificity and accuracy of PET for the detection of cervical nodal metastases was higher than that of CT/MRI and clinical palpation. Although the results did not show a statistically significant difference, PET can still serve as a supplementary method for the identification of nodal metastases of head and neck cancer.

Interplay between short-range correlated disorder and Coulomb interaction in nodal-line semimetals

NASA Astrophysics Data System (ADS)

Wang, Yuxuan; Nandkishore, Rahul M.

2017-09-01

In nodal-line semimetals, Coulomb interactions and short-range correlated disorder are both marginal perturbations to the clean noninteracting Hamiltonian. We analyze their interplay using a weak-coupling renormalization group approach. In the clean case, the Coulomb interaction has been found to be marginally irrelevant, leading to Fermi liquid behavior. We extend the analysis to incorporate the effects of disorder. The nodal line structure gives rise to kinematical constraints similar to that for a two-dimensional Fermi surface, which plays a crucial role in the one-loop renormalization of the disorder couplings. For a twofold degenerate nodal loop (Weyl loop), we show that disorder flows to strong coupling along a unique fixed trajectory in the space of symmetry inequivalent disorder couplings. Along this fixed trajectory, all symmetry inequivalent disorder strengths become equal. For a fourfold degenerate nodal loop (Dirac loop), disorder also flows to strong coupling, however, the strengths of symmetry inequivalent disorder couplings remain different. We show that feedback from disorder reverses the sign of the beta function for the Coulomb interaction, causing the Coulomb interaction to flow to strong coupling as well. However, the Coulomb interaction flows to strong coupling asymptotically more slowly than disorder. Extrapolating our results to strong coupling, we conjecture that at low energies nodal line semimetals should be described by a noninteracting nonlinear sigma model. We discuss the relation of our results with possible many-body localization at zero temperatures in such materials.

Orbital nodal surfaces: Topological challenges for density functionals

NASA Astrophysics Data System (ADS)

Aschebrock, Thilo; Armiento, Rickard; Kümmel, Stephan

2017-06-01

Nodal surfaces of orbitals, in particular of the highest occupied one, play a special role in Kohn-Sham density-functional theory. The exact Kohn-Sham exchange potential, for example, shows a protruding ridge along such nodal surfaces, leading to the counterintuitive feature of a potential that goes to different asymptotic limits in different directions. We show here that nodal surfaces can heavily affect the potential of semilocal density-functional approximations. For the functional derivatives of the Armiento-Kümmel (AK13) [Phys. Rev. Lett. 111, 036402 (2013), 10.1103/PhysRevLett.111.036402] and Becke88 [Phys. Rev. A 38, 3098 (1988), 10.1103/PhysRevA.38.3098] energy functionals, i.e., the corresponding semilocal exchange potentials, as well as the Becke-Johnson [J. Chem. Phys. 124, 221101 (2006), 10.1063/1.2213970] and van Leeuwen-Baerends (LB94) [Phys. Rev. A 49, 2421 (1994), 10.1103/PhysRevA.49.2421] model potentials, we explicitly demonstrate exponential divergences in the vicinity of nodal surfaces. We further point out that many other semilocal potentials have similar features. Such divergences pose a challenge for the convergence of numerical solutions of the Kohn-Sham equations. We prove that for exchange functionals of the generalized gradient approximation (GGA) form, enforcing correct asymptotic behavior of the potential or energy density necessarily leads to irregular behavior on or near orbital nodal surfaces. We formulate constraints on the GGA exchange enhancement factor for avoiding such divergences.

Nodal Green’s Function Method Singular Source Term and Burnable Poison Treatment in Hexagonal Geometry

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

A.A. Bingham; R.M. Ferrer; A.M. ougouag

2009-09-01

An accurate and computationally efficient two or three-dimensional neutron diffusion model will be necessary for the development, safety parameters computation, and fuel cycle analysis of a prismatic Very High Temperature Reactor (VHTR) design under Next Generation Nuclear Plant Project (NGNP). For this purpose, an analytical nodal Green’s function solution for the transverse integrated neutron diffusion equation is developed in two and three-dimensional hexagonal geometry. This scheme is incorporated into HEXPEDITE, a code first developed by Fitzpatrick and Ougouag. HEXPEDITE neglects non-physical discontinuity terms that arise in the transverse leakage due to the transverse integration procedure application to hexagonal geometry andmore » cannot account for the effects of burnable poisons across nodal boundaries. The test code being developed for this document accounts for these terms by maintaining an inventory of neutrons by using the nodal balance equation as a constraint of the neutron flux equation. The method developed in this report is intended to restore neutron conservation and increase the accuracy of the code by adding these terms to the transverse integrated flux solution and applying the nodal Green’s function solution to the resulting equation to derive a semi-analytical solution.« less

Tumor Volume Is a Prognostic Factor in Non-Small-Cell Lung Cancer Treated With Chemoradiotherapy

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

Alexander, Brian M.; Othus, Megan; Caglar, Hale B.

2011-04-01

Purpose: To investigate whether primary tumor and nodal volumes defined on radiotherapy planning scans are correlated with outcome (survival and recurrence) after combined-modality treatment. Methods and Materials: A retrospective review of patients with Stage III non-small-cell lung cancer treated with chemoradiation at Brigham and Women's Hospital/Dana-Farber Cancer Institute from 2000 to 2006 was performed. Tumor and nodal volume measurements, as computed by Eclipse (Varian, Palo Alto, CA), were used as independent variables, along with existing clinical factors, in univariate and multivariate analyses for association with outcomes. Results: For patients treated with definitive chemoradiotherapy, both nodal volume (hazard ratio [HR], 1.09;more » p < 0.01) and tumor volume (HR, 1.03; p < 0.01) were associated with overall survival on multivariate analysis. Both nodal volume (HR, 1.10; p < 0.01) and tumor volume (HR, 1.04; p < 0.01) were also associated with local control but not distant metastases. Conclusions: In addition to traditional surgical staging variables, disease burden, measured by primary tumor and nodal metastases volume, provides information that may be helpful in determining prognosis and identifying groups of patients for which more aggressive local therapy is warranted.« less

Theory of nodal s ±-wave pairing symmetry in the Pu-based 115 superconductor family

DOE PAGES

Das, Tanmoy; Zhu, Jian -Xin; Graf, Matthias J.

2015-02-27

The spin-fluctuation mechanism of superconductivity usually results in the presence of gapless or nodal quasiparticle states in the excitation spectrum. Nodal quasiparticle states are well established in copper-oxide, and heavy-fermion superconductors, but not in iron-based superconductors. Here, we study the pairing symmetry and mechanism of a new class of plutonium-based high-T c superconductors and predict the presence of a nodal s⁺⁻ wave pairing symmetry in this family. Starting from a density-functional theory (DFT) based electronic structure calculation we predict several three-dimensional (3D) Fermi surfaces in this 115 superconductor family. We identify the dominant Fermi surface “hot-spots” in the inter-band scatteringmore » channel, which are aligned along the wavevector Q = (π, π, π), where degeneracy could induce sign-reversal of the pairing symmetry. Our calculation demonstrates that the s⁺⁻ wave pairing strength is stronger than the previously thought d-wave pairing; and more importantly, this pairing state allows for the existence of nodal quasiparticles. Finally, we predict the shape of the momentum- and energy-dependent magnetic resonance spectrum for the identification of this pairing symmetry.« less

Defense Horizons. Number 31, September 2003. Technology, Transformation, and New Operational Concepts

DTIC Science & Technology

2003-09-01

armor would provide both individual and commander a continuous medical status report. Edible vaccines genetically engineered into food could deliver...Defense economic opportunities; transition from the familiar Cold War threat to one that is non-nodal, more pervasive, and often nonstate, nonde...The Role of Technology in Transformation The military that was developed to fight the Cold War in a bi- polar world must transform to meet current and

Coupled phase field, heat conduction, and elastodynamic simulations of kinetic superheating and nanoscale melting of aluminum nanolayer irradiated by picosecond laser.

PubMed

Hwang, Yong Seok; Levitas, Valery I

2015-12-21

An advanced continuum model for nanoscale melting and kinetic superheating of an aluminum nanolayer irradiated by a picosecond laser is formulated. Barrierless nucleation of surface premelting and melting occurs, followed by a propagation of two solid-melt interfaces toward each other and their collision. For a slow heating rate of Q = 0.015 K ps(-1) melting occurs at the equilibrium melting temperature under uniaxial strain conditions T = 898.1 K (i.e., below equilibrium melting temperature Teq = 933.67 K) and corresponding biaxial stresses, which relax during melting. For a high heating rate of Q = 0.99-84 K ps(-1), melting occurs significantly above Teq. Surprisingly, an increase in heating rate leads to temperature reduction at the 3 nm wide moving interfaces due to fast absorption of the heat of fusion. A significant, rapid temperature drop (100-500 K, even below melting temperature) at the very end of melting is revealed, which is caused by the collision of two finite-width interfaces and accelerated melting in about the 5 nm zone. For Q = 25-84 K ps(-1), standing elastic stress waves are observed in a solid with nodal points at the moving solid-melt interfaces, which, however, do not have a profound effect on melting time or temperatures. When surface melting is suppressed, barrierless bulk melting occurs in the entire sample, and elastodynamic effects are more important. Good correspondence with published, experimentally-determined melting time is found for a broad range of heating rates. Similar approaches can be applied to study various phase transformations in different materials and nanostructures under high heating rates.

Interface dermatitis in skin lesions of Kikuchi-Fujimoto's disease: a histopathological marker of evolution into systemic lupus erythematosus?

PubMed

Paradela, S; Lorenzo, J; Martínez-Gómez, W; Yebra-Pimentel, T; Valbuena, L; Fonseca, E

2008-12-01

Kikuchi's disease (KD) is a self-limiting histiocytic necrotizing lymphadenitis (HNL). Cutaneous manifestations are frequent and usually show histopathological findings similar to those observed in the involved lymph nodes. HNL with superposed histological features to KD has been described in patients with lupus erythematosus (LE), and a group of healthy patients previously reported as having HNL may evolve into LE after several months. Up to date, features to predict which HNL patients will have a self-limiting disease and which could develop LE have been not identified. In order to clarify the characteristics of skin lesions associated with KD, we report a case of HNL with evolution into systemic lupus erythematosus (SLE) and a review of previous reports of KD with cutaneous manifestations. A 17-year-old woman presented with a 4-month history of fever and generalised lymphadenopathy. A diagnosis of HNL was established based on a lymph node biopsy. One month later, she developed an erythematoedematous rash on her upper body, with histopathological findings of interface dermatitis. After 8 months, anti-nuclear antibodies (ANA) at titre of 1/320, anti-DNA-ds antibodies and marked decrease of complement levels were detected. During the following 2 years, she developed diagnostic criteria for SLE, with arthralgias, pleuritis, aseptic meningitis, haemolytic anaemia and lupus nephritis. To our knowledge, 27 cases of nodal and cutaneous KD have been reported, 9 of which later developed LE. In all these patients, the skin biopsy revealed interface dermatitis. Skin biopsy revealed a pattern of interface dermatitis in all reviewed KD cases, which evolved into LE. Even this histopathological finding was not previously considered significant; it might be a marker of evolution into LE.

F18 FDG positron emission tomography revelation of primary testicular lymphoma with concurrent multiple extra nodal involvement

PubMed Central

Vamsy, Mohana; Dattatreya, PS; Parakh, Megha; Dayal, Monal; Rao, VVS Prabhakar

2013-01-01

Primary testicular lymphoma (PTL) a relatively rare disease of non-Hodgkin's lymphomas occurring with a lesser incidence of 1-2% has a propensity to occur at later ages above 50 years. PTL spreads to extra nodal sites due to deficiency of extra cellular adhesion molecules. We present detection of multiple sites of extra nodal involvement of PTL by F-18 positron emission tomography/computed tomography study aiding early detection of the dissemination thus aiding in staging and management. PMID:24019676

Target volume delineation for radical radiotherapy of early oesophageal carcinoma in elderly patients.

PubMed

Su, J; Zhu, S; Liu, Z; Zhao, Y; Song, C

2017-02-01

To compare the prognosis of elderly patients with early oesophageal carcinoma between radical elective nodal prophylactic irradiation and involved-field irradiation and to estimate the failure modes and adverse effects, then to provide the patients the safe and individual therapeutic regimens. The charts of 96 patients aged 65 and over with early stage oesophageal carcinoma receiving radical radiotherapy in our department were retrospectively analysed. Of all the patients, 49 received elective nodal prophylactic irradiation and the other 47 received involved-field irradiation. After completion of the whole treatment, we analysed short-term effects, tumour local control, overall survival of the patients, failure modes and adverse effects. The 1-, 3-, and 5-year local control rate in elective nodal irradiation and involved-field irradiation groups were 80.6%, 57.4%, 54.0% and 65.4%, 46.5%, 30.5% respectively, and the difference was statistically significant (χ 2 =4.478, P=0.03). The differences of overall survival and progression-free survival were not significant (P>0.05). The difference of 1-, 3-, and 5-years local regional failure rate was statistically significant between elective nodal prophylactic irradiation and involved-field irradiation groups, except for the overall failure and distant metastasis rates. The overall incidence of radiation-induced oesophagitis after elective nodal irradiation or involved-field irradiation was 79.6% and 59.6%, and the difference was statistically significant (χ 2 =4.559, P=0.03). The difference of radiation pneumonitis between elective nodal prophylactic irradiation and involved-field irradiation was not significant (12.2% vs 14.9%; χ 2 =0.144, P=0.7). For elderly patients with early stage oesophageal carcinoma receiving radical radiotherapy, although elective nodal prophylactic irradiation could increase the incidence of radiation-induced oesophagitis, patients could tolerate the treatment and benefit from local control. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Review analysis of medullary carcinoma of the thyroid: a 15-year Indian experience.

PubMed

Dorairajan, N; Siddharth, D; Kanna, Srinivasulu

2006-01-01

The aim of this study was to emphasize the importance of adequate primary surgery in cases of medullary carcinoma of the thyroid. We retrospectively reviewed 44 cases of medullary carcinoma of the thyroid treated in Government General Hospital, Chennai between 1987 and 2002. Patients who underwent total thyroidectomy with only central compartment dissection were compared with those who had undergone total thyroidectomy with meticulous triple compartment (bilateral lateral and central groups) nodal dissection. The group of total thyroidectomy with only central compartment dissection had a high rate of lymph nodal recurrence and persistent hypercalcitoninemia compared with the group with total thyroidectomy with meticulous triple compartment nodal dissection. (chi square, 4.503; P > 0.05). Primary surgery with total thyroidectomy with meticulous triple compartment dissection is superior to total thyroidectomy with central compartment dissection alone in terms of preventing nodal and local recurrences and achieving normal (basal and stimulated) serum calcitonin levels postoperatively.

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

Deka, Deepjyoti; Backhaus, Scott N.; Chertkov, Michael

Limited placement of real-time monitoring devices in the distribution grid, recent trends notwithstanding, has prevented the easy implementation of demand-response and other smart grid applications. Part I of this paper discusses the problem of learning the operational structure of the grid from nodal voltage measurements. In this work (Part II), the learning of the operational radial structure is coupled with the problem of estimating nodal consumption statistics and inferring the line parameters in the grid. Based on a Linear-Coupled(LC) approximation of AC power flows equations, polynomial time algorithms are designed to identify the structure and estimate nodal load characteristics and/ormore » line parameters in the grid using the available nodal voltage measurements. Then the structure learning algorithm is extended to cases with missing data, where available observations are limited to a fraction of the grid nodes. The efficacy of the presented algorithms are demonstrated through simulations on several distribution test cases.« less

Cryopreservation of in vitro grown nodal segments of Rauvolfia serpentina by PVS2 vitrification.

PubMed

Ray, Avik; Bhattacharya, Sabita

2008-01-01

This paper describes the cryopreservation by PVS2 vitrification of Rauvolfia serpentina (L.) Benth ex kurz, an important tropical medicinal plant. The effects of type and size of explants, sucrose preculture (duration and concentration) and vitrification treatment were tested. Preliminary experiments with PVS1, 2 and 3 produced shoot growth only for PVS2. When optimizing the PVS2 vitrification of nodal segments, those of 0.31 - 0.39 cm in size were better than other nodal sizes and or apices. Sucrose preculture had a positive role in survival and subsequent regrowth of the cryopreserved explants. Seven days on 0.5 M sucrose solution significantly improved the viability of nodal segments. PVS2 incubation for 45 minutes combined with a 7-day preculture gave the optimum result of 66 percent. Plantlets derived after cryopreservation resumed growth and regenerated normally.

Constructing a polynomial whose nodal set is the three-twist knot 52

NASA Astrophysics Data System (ADS)

Dennis, Mark R.; Bode, Benjamin

2017-06-01

We describe a procedure that creates an explicit complex-valued polynomial function of three-dimensional space, whose nodal lines are the three-twist knot 52. The construction generalizes a similar approach for lemniscate knots: a braid representation is engineered from finite Fourier series and then considered as the nodal set of a certain complex polynomial which depends on an additional parameter. For sufficiently small values of this parameter, the nodal lines form the three-twist knot. Further mathematical properties of this map are explored, including the relationship of the phase critical points with the Morse-Novikov number, which is nonzero as this knot is not fibred. We also find analogous functions for other simple knots and links. The particular function we find, and the general procedure, should be useful for designing knotted fields of particular knot types in various physical systems.

Isospectral discrete and quantum graphs with the same flip counts and nodal counts

NASA Astrophysics Data System (ADS)

Juul, Jonas S.; Joyner, Christopher H.

2018-06-01

The existence of non-isomorphic graphs which share the same Laplace spectrum (to be referred to as isospectral graphs) leads naturally to the following question: what additional information is required in order to resolve isospectral graphs? It was suggested by Band, Shapira and Smilansky that this might be achieved by either counting the number of nodal domains or the number of times the eigenfunctions change sign (the so-called flip count) (Band et al 2006 J. Phys. A: Math. Gen. 39 13999–4014 Band and Smilansky 2007 Eur. Phys. J. Spec. Top. 145 171–9). Recent examples of (discrete) isospectral graphs with the same flip count and nodal count have been constructed by Ammann by utilising Godsil–McKay switching (Ammann private communication). Here, we provide a simple alternative mechanism that produces systematic examples of both discrete and quantum isospectral graphs with the same flip and nodal counts.

Three-dimensional graphdiyne as a topological nodal-line semimetal

NASA Astrophysics Data System (ADS)

Nomura, Takafumi; Habe, Tetsuro; Sakamoto, Ryota; Koshino, Mikito

2018-05-01

We study the electronic band structure of three-dimensional ABC-stacked (rhombohedral) graphdiyne, which is a new planar carbon allotrope recently fabricated. Using first-principles calculation, we show that the system is a nodal-line semimetal, in which the conduction band and valence band cross at a closed ring in the momentum space. We derive the minimum tight-binding model and the low-energy effective Hamiltonian in a 4 ×4 matrix form. The nodal line is protected by a nontrivial winding number, and it ensures the existence of the topological surface state in a finite-thickness slab. The Fermi surface of the doped system exhibits a peculiar, self-intersecting hourglass structure, which is quite different from the torus or pipe shape in the previously proposed nodal semimetals. Despite its simple configuration, three-dimensional graphdiyne offers unique electronic properties distinct from any other carbon allotropes.

Coexistence of tunable Weyl points and topological nodal lines in ternary transition-metal telluride TaIrT e4

NASA Astrophysics Data System (ADS)

Zhou, Xiaoqing; Liu, Qihang; Wu, QuanSheng; Nummy, Tom; Li, Haoxiang; Griffith, Justin; Parham, Stephen; Waugh, Justin; Emmanouilidou, Eve; Shen, Bing; Yazyev, Oleg V.; Ni, Ni; Dessau, Daniel

2018-06-01

We report a combined theoretical and experimental study on TaIrT e4 , a potential candidate for a minimal model of type-II Weyl semimetals. Unexpectedly, an intriguing node structure with 12 Weyl points and a pair of nodal lines protected by mirror symmetry was found by first-principles calculations. Some signatures of the complex electronic structure, such as topologically nontrivial band crossings and topologically trivial Fermi arcs, are cross-validated by angle-resolved photoemission spectroscopy. Through external strain, the number of Weyl points can be reduced to a theoretical minimum of four, and the appearance of the nodal lines can be switched between different mirror planes in momentum space. The coexistence of switchable Weyl points and nodal lines establishes transition-metal chalcogenides as a unique test ground for topological state characterization and engineering.

Analysis of nodal coverage utilizing image guided radiation therapy for primary gynecologic tumor volumes

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

Ahmed, Faisal; Loma Linda University Medical Center, Department of Radiation Oncology, Loma Linda, CA; Sarkar, Vikren

Purpose: To evaluate radiation dose delivered to pelvic lymph nodes, if daily Image Guided Radiation Therapy (IGRT) was implemented with treatment shifts based on the primary site (primary clinical target volume [CTV]). Our secondary goal was to compare dosimetric coverage with patient outcomes. Materials and methods: A total of 10 female patients with gynecologic malignancies were evaluated retrospectively after completion of definitive intensity-modulated radiation therapy (IMRT) to their pelvic lymph nodes and primary tumor site. IGRT consisted of daily kilovoltage computed tomography (CT)-on-rails imaging fused with initial planning scans for position verification. The initial plan was created using Varian's Eclipsemore » treatment planning software. Patients were treated with a median radiation dose of 45 Gy (range: 37.5 to 50 Gy) to the primary volume and 45 Gy (range: 45 to 64.8 Gy) to nodal structures. One IGRT scan per week was randomly selected from each patient's treatment course and re-planned on the Eclipse treatment planning station. CTVs were recreated by fusion on the IGRT image series, and the patient's treatment plan was applied to the new image set to calculate delivered dose. We evaluated the minimum, maximum, and 95% dose coverage for primary and nodal structures. Reconstructed primary tumor volumes were recreated within 4.7% of initial planning volume (0.9% to 8.6%), and reconstructed nodal volumes were recreated to within 2.9% of initial planning volume (0.01% to 5.5%). Results: Dosimetric parameters averaged less than 10% (range: 1% to 9%) of the original planned dose (45 Gy) for primary and nodal volumes on all patients (n = 10). For all patients, ≥99.3% of the primary tumor volume received ≥ 95% the prescribed dose (V95%) and the average minimum dose was 96.1% of the prescribed dose. In evaluating nodal CTV coverage, ≥ 99.8% of the volume received ≥ 95% the prescribed dose and the average minimum dose was 93%. In evaluating individual IGRT sessions, we found that 6 patients had an estimated minimal nodal CTV dose less than 90% (range: 78 to 99%) of that planned. With a median follow-up of 42.5 months, 2 patients experienced systemic disease progression at an average of 19.6 months. One patient was found to have a local or regional failure with an average follow-up of 42 months. Conclusion: Using only 3 dimensional IGRT corrections in gynecological radiation allows excellent coverage of the primary target volume and good average nodal CTV coverage. If IGRT corrections are based on alignment to the primary tumor volume, and is only able to be corrected in 3 degrees, this can create situations in which nodal volumes may be under dosed. Utilizing multiple IGRT sessions appears to average out dose discrepancies over the course of treatment. The implication of underdosing in a single IGRT session needs further evaluation in future studies. Based on the concern of minimum dose to a nodal target volume, these findings may signal caution when using IGRT and IMRT in gynecological radiation patients. Possible techniques to overcome this situation may include averaging shifts between tumor and nodal volume, use of a treatment couch with 6° of freedom, deformable registration, or adaptive planning.« less

Intensity-Modulated Proton Therapy for Elective Nodal Irradiation and Involved-Field Radiation in the Definitive Treatment of Locally Advanced Non-Small Cell Lung Cancer: A Dosimetric Study

PubMed Central

Kesarwala, Aparna H.; Ko, Christine J.; Ning, Holly; Xanthopoulos, Eric; Haglund, Karl E.; O’Meara, William P.; Simone, Charles B.; Rengan, Ramesh

2015-01-01

Background Photon involved-field radiation therapy (IFRT), the standard for locally advanced non-small cell lung cancer (LA-NSCLC), results in favorable outcomes without increased isolated nodal failures, perhaps from scattered dose to elective nodal stations. Given the high conformality of intensity-modulated proton therapy (IMPT), proton IFRT could increase nodal failures. We investigated the feasibility of IMPT for elective nodal irradiation (ENI) in LA-NSCLC. Materials and Methods IMPT IFRT plans were generated to the same total dose of 66.6–72 Gy received by 20 LA-NSCLC patients treated with photon IFRT. IMPT ENI plans were generated to 46 CGE to elective nodal (EN) planning treatment volumes (PTV) plus 24 CGE to involved field (IF)-PTVs. Results Proton IFRT and ENI both improved D95 involved field (IF)-PTV coverage by 4% (p<0.01) compared to photon IFRT. All evaluated dosimetric parameters improved significantly with both proton plans. Lung V20 and mean lung dose decreased 18% (p<0.01) and 36% (p<0.01), respectively, with proton IFRT and 11% (p=0.03) and 26% (p<0.01) with ENI. Mean esophagus dose decreased 16% with IFRT and 12% with ENI; heart V25 decreased 63% with both (all p<0.01). Conclusions This study demonstrates the feasibility of IMPT for LA-NSCLC ENI. Potential decreased toxicity indicates IMPT could allow ENI while maintaining a favorable therapeutic ratio compared to photon IFRT. PMID:25604729

Intensity-modulated proton therapy for elective nodal irradiation and involved-field radiation in the definitive treatment of locally advanced non-small-cell lung cancer: a dosimetric study.

PubMed

Kesarwala, Aparna H; Ko, Christine J; Ning, Holly; Xanthopoulos, Eric; Haglund, Karl E; O'Meara, William P; Simone, Charles B; Rengan, Ramesh

2015-05-01

Photon involved-field (IF) radiation therapy (IFRT), the standard for locally advanced (LA) non-small cell lung cancer (NSCLC), results in favorable outcomes without increased isolated nodal failures, perhaps from scattered dose to elective nodal stations. Because of the high conformality of intensity-modulated proton therapy (IMPT), proton IFRT could increase nodal failures. We investigated the feasibility of IMPT for elective nodal irradiation (ENI) in LA-NSCLC. IMPT IFRT plans were generated to the same total dose of 66.6-72 Gy received by 20 LA-NSCLC patients treated with photon IFRT. IMPT ENI plans were generated to 46 cobalt Gray equivalent (CGE) to elective nodal planning treatment volumes (PTV) plus 24 CGE to IF-PTVs. Proton IFRT and ENI improved the IF-PTV percentage of volume receiving 95% of the prescribed dose (D95) by 4% (P < .01) compared with photon IFRT. All evaluated dosimetric parameters improved significantly with both proton plans. The lung percentage of volume receiving 20 Gy/CGE (V20) and mean lung dose decreased 18% (P < .01) and 36% (P < .01), respectively, with proton IFRT, and 11% (P = .03) and 26% (P < .01) with ENI. The mean esophagus dose decreased 16% with IFRT and 12% with ENI; heart V25 decreased 63% with both (all P < .01). This study demonstrates the feasibility of IMPT for LA-NSCLC ENI. Potential decreased toxicity indicates that IMPT could allow ENI while maintaining a favorable therapeutic ratio compared with photon IFRT. Published by Elsevier Inc.

Radiotherapy for esthesioneuroblastoma: is elective nodal irradiation warranted in the multimodality treatment approach?

PubMed

Noh, O Kyu; Lee, Sang-wook; Yoon, Sang Min; Kim, Sung Bae; Kim, Sang Yoon; Kim, Chang Jin; Jo, Kyung Ja; Choi, Eun Kyung; Song, Si Yeol; Kim, Jong Hoon; Ahn, Seung Do

2011-02-01

The role of elective nodal irradiation (ENI) in radiotherapy for esthesioneuroblastoma (ENB) has not been clearly defined. We analyzed treatment outcomes of patients with ENB and the frequency of cervical nodal failure in the absence of ENI. Between August 1996 and December 2007, we consulted with 19 patients with ENB regarding radiotherapy. Initial treatment consisted of surgery alone in 2 patients; surgery and postoperative radiotherapy in 4; surgery and adjuvant chemotherapy in 1; surgery, postoperative radiotherapy, and chemotherapy in 3; and chemotherapy followed by radiotherapy or concurrent chemoradiotherapy in 5. Five patients did not receive planned radiotherapy because of disease progression. Including 2 patients who received salvage radiotherapy, 14 patients were treated with radiotherapy. Elective nodal irradiation was performed in 4 patients with high-risk factors, including 3 with cervical lymph node metastasis at presentation. Fourteen patients were analyzable, with a median follow-up of 27 months (range, 7-64 months). The overall 3-year survival rate was 73.4%. Local failure occurred in 3 patients (21.4%), regional cervical failure in 3 (21.4%), and distant failure in 2 (14.3%). No cervical nodal failure occurred in patients treated with combined systemic chemotherapy regardless of ENI. Three cervical failures occurred in the 4 patients treated with ENI or neck dissection (75%), none of whom received systemic chemotherapy. ENI during radiotherapy for ENB seems to play a limited role in preventing cervical nodal failure. Omitting ENI may be an option if patients are treated with a combination of radiotherapy and chemotherapy. Copyright © 2011 Elsevier Inc. All rights reserved.

Sentinel lymph node biopsy in early-stage cervical cancer: utility of intraoperative versus postoperative assessment.

PubMed

Fader, A Nickles; Edwards, R P; Cost, M; Kanbour-Shakir, A; Kelley, J L; Schwartz, B; Sukumvanich, P; Comerci, J; Sumkin, J; Elishaev, E; Rohan, L Cencia

2008-10-01

To determine the diagnostic accuracy of sentinel lymph node (SLN) detection using lymphoscintigraphy, intraoperative blue dye, and radiocolloid in patients with early-stage cervical cancer. Intra-cervical injection of technetium-99 sulfur colloid and lymphoscintigraphy were performed preoperatively. Isosulfan blue was injected intra-cervically immediately prior to surgery. SLNs were excised and examined intraoperatively (imprint cytology and frozen section) and postoperatively (H and E histology and immunohistochemistry (IHC) for cytokeratin). Thirty eight patients were evaluable. Laparoscopy and laparotomy were performed in 28.9% and 71.1%, respectively. Subjects had squamous cell carcinoma (n=26), adenocarcinoma (n=10) or adenosquamous (n=2) histologies. 55.3% had cervical tumors <2 cm. The overall SLN detection rate was 92.1%. The external iliac region just distal to the common iliac bifurcation was the most common SLN location. A mean of 2.1 SLNs were detected per patient with bilateral SLNs observed in 47.4%. On final pathology, metastatic nodal disease was identified in 15.7% of patients. Of these, 83.3% were detected in the SLNs. Sensitivity of SLN detection of metastasis was 100% for patients with cervical tumors <2 cm. However intraoperative evaluation by imprint cytology and frozen section correctly identified lymph node metastasis in only 33.3%. SLN detection is feasible and accurately reflects pelvic nodal basin status when performed in early-stage cervical cancer patients. However, while current intraoperative pathology techniques for assessing nodal metastases reliably detect metastases larger than 2 mm, they lack sufficient sensitivity to detect micrometastasis and isolated tumor cells.

T-cell lymphomas in South america and europe.

PubMed

Bellei, Monica; Chiattone, Carlos Sergio; Luminari, Stefano; Pesce, Emanuela Anna; Cabrera, Maria Elena; de Souza, Carmino Antonio; Gabús, Raul; Zoppegno, Lucia; Zoppegno, Lucia; Milone, Jorge; Pavlovsky, Astrid; Connors, Joseph Michael; Foss, Francine Mary; Horwitz, Steven Michael; Liang, Raymond; Montoto, Silvia; Pileri, Stefano Aldo; Polliack, Aaron; Vose, Julie Marie; Zinzani, Pier Luigi; Zucca, Emanuele; Federico, Massimo

2012-01-01

Peripheral T-cell lymphomas are a group of rare neoplasms originating from clonal proliferation of mature post-thymic lymphocytes with different entities having specific biological characteristics and clinical features. As natural killer cells are closely related to T-cells, natural killer-cell lymphomas are also part of the group. The current World Health Organization classification recognizes four categories of T/natural killer-cell lymphomas with respect to their presentation: disseminated (leukemic), nodal, extranodal and cutaneous. Geographic variations in the distribution of these diseases are well documented: nodal subtypes are more frequent in Europe and North America, while extranodal forms, including natural killer-cell lymphomas, occur almost exclusively in Asia and South America. On the whole, T-cell lymphomas are more common in Asia than in western countries, usually affect adults, with a higher tendency in men, and, excluding a few subtypes, usually have an aggressive course and poor prognosis. Apart from anaplastic lymphoma kinase-positive anaplastic large cell lymphoma, that have a good outcome, other nodal and extranodal forms have a 5-year overall survival of about 30%. According to the principal prognostic indexes, the majority of patients are allocated to the unfavorable subset. In the past, the rarity of these diseases prevented progress in the understanding of their biology and improvements in the efficaciousness of therapy. Recently, international projects devoted to these diseases created networks promoting investigations on T-cell lymphomas. These projects are the basis of forthcoming cooperative, large scale trials to detail biologic characteristics of each sub-entity and to possibly individuate targets for new therapies.

T-Cell Lymphomas in South America and Europe

PubMed Central

Bellei, Monica; Chiattone, Carlos Sergio; Luminari, Stefano; Pesce, Emanuela Anna; Cabrera, Maria Elena; de Souza, Carmino Antonio; Gabús, Raul; Zoppegno, Lucia; Zoppegno, Lucia; Milone, Jorge; Pavlovsky, Astrid; Connors, Joseph Michael; Foss, Francine Mary; Horwitz, Steven Michael; Liang, Raymond; Montoto, Silvia; Pileri, Stefano Aldo; Polliack, Aaron; Vose, Julie Marie; Zinzani, Pier Luigi; Zucca, Emanuele; Federico, Massimo

2012-01-01

Peripheral T-cell lymphomas are a group of rare neoplasms originating from clonal proliferation of mature post-thymic lymphocytes with different entities having specific biological characteristics and clinical features. As natural killer cells are closely related to T-cells, natural killer-cell lymphomas are also part of the group. The current World Health Organization classification recognizes four categories of T/natural killer-cell lymphomas with respect to their presentation: disseminated (leukemic), nodal, extranodal and cutaneous. Geographic variations in the distribution of these diseases are well documented: nodal subtypes are more frequent in Europe and North America, while extranodal forms, including natural killer-cell lymphomas, occur almost exclusively in Asia and South America. On the whole, T-cell lymphomas are more common in Asia than in western countries, usually affect adults, with a higher tendency in men, and, excluding a few subtypes, usually have an aggressive course and poor prognosis. Apart from anaplastic lymphoma kinase-positive anaplastic large cell lymphoma, that have a good outcome, other nodal and extranodal forms have a 5-year overall survival of about 30%. According to the principal prognostic indexes, the majority of patients are allocated to the unfavorable subset. In the past, the rarity of these diseases prevented progress in the understanding of their biology and improvements in the efficaciousness of therapy. Recently, international projects devoted to these diseases created networks promoting investigations on T-cell lymphomas. These projects are the basis of forthcoming cooperative, large scale trials to detail biologic characteristics of each sub-entity and to possibly individuate targets for new therapies. PMID:23049383

A General Interface Method for Aeroelastic Analysis of Aircraft

NASA Technical Reports Server (NTRS)

Tzong, T.; Chen, H. H.; Chang, K. C.; Wu, T.; Cebeci, T.

1996-01-01

The aeroelastic analysis of an aircraft requires an accurate and efficient procedure to couple aerodynamics and structures. The procedure needs an interface method to bridge the gap between the aerodynamic and structural models in order to transform loads and displacements. Such an interface method is described in this report. This interface method transforms loads computed by any aerodynamic code to a structural finite element (FE) model and converts the displacements from the FE model to the aerodynamic model. The approach is based on FE technology in which virtual work is employed to transform the aerodynamic pressures into FE nodal forces. The displacements at the FE nodes are then converted back to aerodynamic grid points on the aircraft surface through the reciprocal theorem in structural engineering. The method allows both high and crude fidelities of both models and does not require an intermediate modeling. In addition, the method performs the conversion of loads and displacements directly between individual aerodynamic grid point and its corresponding structural finite element and, hence, is very efficient for large aircraft models. This report also describes the application of this aero-structure interface method to a simple wing and an MD-90 wing. The results show that the aeroelastic effect is very important. For the simple wing, both linear and nonlinear approaches are used. In the linear approach, the deformation of the structural model is considered small, and the loads from the deformed aerodynamic model are applied to the original geometry of the structure. In the nonlinear approach, the geometry of the structure and its stiffness matrix are updated in every iteration and the increments of loads from the previous iteration are applied to the new structural geometry in order to compute the displacement increments. Additional studies to apply the aero-structure interaction procedure to more complicated geometry will be conducted in the second phase of the present contract.

Adaptive Nodal Transport Methods for Reactor Transient Analysis

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

Thomas Downar; E. Lewis

2005-08-31

Develop methods for adaptively treating the angular, spatial, and time dependence of the neutron flux in reactor transient analysis. These methods were demonstrated in the DOE transport nodal code VARIANT and the US NRC spatial kinetics code, PARCS.

Conversion of spin current into charge current in a topological insulator: Role of the interface

NASA Astrophysics Data System (ADS)

Dey, Rik; Prasad, Nitin; Register, Leonard F.; Banerjee, Sanjay K.

2018-05-01

Three-dimensional spin current density injected onto the surface of a topological insulator (TI) produces a two-dimensional charge current density on the surface of the TI, which is the so-called inverse Edelstein effect (IEE). The ratio of the surface charge current density on the TI to the spin current density injected across the interface defined as the IEE length was shown to be exactly equal to the mean free path in the TI determined to be independent of the electron transmission rate across the interface [Phys. Rev. B 94, 184423 (2016), 10.1103/PhysRevB.94.184423]. However, we find that the transmission rate across the interface gives a nonzero contribution to the transport relaxation rate in the TI as well as to the effective IEE relaxation rate (over and above any surface hybridization effects), and the IEE length is always less than the original mean free path in the TI without the interface. We show that both the IEE relaxation time and the transport relaxation time in the TI are modified by the interface transmission time. The correction becomes significant when the transmission time across the interface becomes comparable to or less than the original momentum scattering time in the TI. This correction is similar to experimental results in Rashba electron systems in which the IEE relaxation time was found shorter in the case of direct interface with metal in which the interface transmission rate will be much higher, compared to interfaces incorporating insulating oxides. Our results indicate the continued importance of the interface to obtain a better spin-to-charge current conversion and a limitation to the conversion efficiency due to the quality of the interface.

Robot-assisted Salvage Lymph Node Dissection for Clinically Recurrent Prostate Cancer.

PubMed

Montorsi, Francesco; Gandaglia, Giorgio; Fossati, Nicola; Suardi, Nazareno; Pultrone, Cristian; De Groote, Ruben; Dovey, Zach; Umari, Paolo; Gallina, Andrea; Briganti, Alberto; Mottrie, Alexandre

2017-09-01

Salvage lymph node dissection has been described as a feasible treatment for the management of prostate cancer patients with nodal recurrence after primary treatment. To report perioperative, pathologic, and oncologic outcomes of robot-assisted salvage nodal dissection (RASND) in patients with nodal recurrence after radical prostatectomy (RP). We retrospectively evaluated 16 patients affected by nodal recurrence following RP documented by positive positron emission tomography/computed tomography scan. Surgery was performed using DaVinci Si and Xi systems. A pelvic nodal dissection that included lymphatic stations overlying the external, internal, and common iliac vessels, the obturator fossa, and the presacral nodes was performed. In 13 (81.3%) patients a retroperitoneal lymph node dissection that included all nodal tissue located between the aortic bifurcation and the renal vessels was performed. Perioperative outcomes consisted of operative time, blood loss, length of hospital stay, and complications occurred within 30 d after surgery. Biochemical response (BR) was defined as a prostate-specific antigen level <0.2 ng/ml at 40 d after RASND. Median operative time, blood loss, and length of hospital stay were 210min, 250ml, and 3.5 d. The median number of nodes removed was 16.5. Positive lymph nodes were detected in 11 (68.8%) patients. Overall, four (25.0%) and five (31.2%) patients experienced intraoperative and postoperative complications, respectively. Overall, one (6.3%) and four (25.0%) patients had Clavien I and II complications within 30 d after RASND, respectively. Overall, five (33.3%) patients experienced BR after surgery. Our study is limited by the small cohort of patients evaluated and by the follow-up duration. RASND represents a feasible procedure in patients with nodal recurrence after RP and provides acceptable short-term oncologic outcomes, where one out of three patients experience BR immediately after surgery. Long-term data are needed to confirm the effectiveness of this approach. We report our initial experience with robot-assisted salvage nodal dissection for the management of patients with lymph node recurrence after radical prostatectomy. This technique represents a feasible and effective approach, where no high-grade complications were recorded and one out of three patients experienced biochemical response at 40 d after surgery. Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Beat-to-Beat Variation in Periodicity of Local Calcium Releases Contributes to Intrinsic Variations of Spontaneous Cycle Length in Isolated Single Sinoatrial Node Cells

PubMed Central

Monfredi, Oliver; Maltseva, Larissa A.; Spurgeon, Harold A.; Boyett, Mark R.; Lakatta, Edward G.; Maltsev, Victor A.

2013-01-01

Spontaneous, submembrane local Ca2+ releases (LCRs) generated by the sarcoplasmic reticulum in sinoatrial nodal cells, the cells of the primary cardiac pacemaker, activate inward Na+/Ca2+-exchange current to accelerate the diastolic depolarization rate, and therefore to impact on cycle length. Since LCRs are generated by Ca2+ release channel (i.e. ryanodine receptor) openings, they exhibit a degree of stochastic behavior, manifested as notable cycle-to-cycle variations in the time of their occurrence. Aim The present study tested whether variation in LCR periodicity contributes to intrinsic (beat-to-beat) cycle length variability in single sinoatrial nodal cells. Methods We imaged single rabbit sinoatrial nodal cells using a 2D-camera to capture LCRs over the entire cell, and, in selected cells, simultaneously measured action potentials by perforated patch clamp. Results LCRs begin to occur on the descending part of the action potential-induced whole-cell Ca2+ transient, at about the time of the maximum diastolic potential. Shortly after the maximum diastolic potential (mean 54±7.7 ms, n = 14), the ensemble of waxing LCR activity converts the decay of the global Ca2+ transient into a rise, resulting in a late, whole-cell diastolic Ca2+ elevation, accompanied by a notable acceleration in diastolic depolarization rate. On average, cells (n = 9) generate 13.2±3.7 LCRs per cycle (mean±SEM), varying in size (7.1±4.2 µm) and duration (44.2±27.1 ms), with both size and duration being greater for later-occurring LCRs. While the timing of each LCR occurrence also varies, the LCR period (i.e. the time from the preceding Ca2+ transient peak to an LCR’s subsequent occurrence) averaged for all LCRs in a given cycle closely predicts the time of occurrence of the next action potential, i.e. the cycle length. Conclusion Intrinsic cycle length variability in single sinoatrial nodal cells is linked to beat-to-beat variations in the average period of individual LCRs each cycle. PMID:23826247

Equilibrium Wall Model Implementation in a Nodal Finite Element Flow Solver JENRE for Large Eddy Simulations

DTIC Science & Technology

2017-11-13

condition is applied to the inviscid and viscous fluxes on the wall to satisfy the surface physical condition, but a non -zero surface tangential...velocity profiles and turbulence quantities predicted by the current wall-model implementation agree well with available experimental data and...implementations. The volume and surface integrals based on the non -zero surface velocity in a cell adjacent to the wall show a good agreement with those

Nexus networks in carbon honeycombs

NASA Astrophysics Data System (ADS)

Chen, Yuanping; Xie, Yuee; Gao, Yan; Chang, Po-Yao; Zhang, Shengbai; Vanderbilt, David

2018-04-01

Nexus metals represent a new type of topological material in which nodal lines merge at nexus points. Here we propose novel networks in nexus systems through intertwining between nexus fermions and additional nodal lines. These nexus networks can be realized in recently synthesized carbon honeycomb materials. In these carbon honeycombs, we demonstrate a phase transition between a nexus network and a system with triply degenerate points and additional nodal lines. The Landau level spectra show unusual magnetic transport properties in the nexus networks. Our results pave the way toward realizations of new topological materials with novel transport properties beyond standard Weyl/Dirac semimetals.

Oestrogen receptors, nodes and stage as predictors of post-recurrence survival in 457 breast cancer patients.

PubMed

Shek, L L; Godolphin, W; Spinelli, J J

1987-12-01

The relationship to survival after first recurrence of oestrogen receptor (ER), nodal status and TNM stage at diagnosis, and treatment for advanced disease was studied in 457 females whose primary breast cancer was diagnosed in 1975 to 1981. Receptor concentration was the most important predictor of post-recurrence survival, with some additional information conveyed by nodal status. ER predicted survival after recurrence independently of nodal status, clinical stage or mode of therapy. Response to endocrine therapy is only a facet of the generally favourable prognosis of ER positive patients, rather than the sole explanation.

Segregated nodal domains of two-dimensional multispecies Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Chang, Shu-Ming; Lin, Chang-Shou; Lin, Tai-Chia; Lin, Wen-Wei

2004-09-01

In this paper, we study the distribution of m segregated nodal domains of the m-mixture of Bose-Einstein condensates under positive and large repulsive scattering lengths. It is shown that components of positive bound states may repel each other and form segregated nodal domains as the repulsive scattering lengths go to infinity. Efficient numerical schemes are created to confirm our theoretical results and discover a new phenomenon called verticillate multiplying, i.e., the generation of multiple verticillate structures. In addition, our proposed Gauss-Seidel-type iteration method is very effective in that it converges linearly in 10-20 steps.

Long period nodal motion of sun synchronous orbits

NASA Technical Reports Server (NTRS)

Duck, K. I.

1975-01-01

An approximative model is formulated for assessing these perturbations that significantly affect long term modal motion of sun synchronous orbits. Computer simulations with several independent computer programs consider zonal and tesseral gravitational harmonics, third body gravitational disturbances induced by the sun and the moon, and atmospheric drag. A pendulum model consisting of evenzonal harmonics through order 4 and solar gravity dominated nodal motion approximation. This pendulum motion results from solar gravity inducing an inclination oscillation which couples into the nodal precession induced by the earth's oblateness. The pendulum model correlated well with simulations observed flight data.

[Does nodal irradiation (clavicular and internal mammary chains) increase the toxicity of adjuvant breast radiotherapy?].

PubMed

Riou, O; Bourgier, C; Fenoglietto, P; Azria, D

2015-06-01

Treatment volume is a major risk factor of radiation-induced toxicity. As nodal irradiation increases treatment volume, radiation toxicity should be greater. Nevertheless, scientific randomised data do not support this fact. However, a radiation-induced toxicity is possible outside tangential fields in the nodal volumes not related to breast-only treatment. Treatment should not be adapted only to the disease but personalized to the individual risk of toxicity for each patient. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Nodal signalling in Xenopus: the role of Xnr5 in left/right asymmetry and heart development.

PubMed

Tadjuidje, Emmanuel; Kofron, Matthew; Mir, Adnan; Wylie, Christopher; Heasman, Janet; Cha, Sang-Wook

2016-08-01

Nodal class TGF-β signalling molecules play essential roles in establishing the vertebrate body plan. In all vertebrates, nodal family members have specific waves of expression required for tissue specification and axis formation. In Xenopus laevis, six nodal genes are expressed before gastrulation, raising the question of whether they have specific roles or act redundantly with each other. Here, we examine the role of Xnr5. We find it acts at the late blastula stage as a mesoderm inducer and repressor of ectodermal gene expression, a role it shares with Vg1. However, unlike Vg1, Xnr5 depletion reduces the expression of the nodal family member xnr1 at the gastrula stage. It is also required for left/right laterality by controlling the expression of the laterality genes xnr1, antivin (lefty) and pitx2 at the tailbud stage. In Xnr5-depleted embryos, the heart field is established normally, but symmetrical reduction in Xnr5 levels causes a severely stunted midline heart, first evidenced by a reduction in cardiac troponin mRNA levels, while left-sided reduction leads to randomization of the left/right axis. This work identifies Xnr5 as the earliest step in the signalling pathway establishing normal heart laterality in Xenopus. © 2016 The Authors.

GDF3 is a BMP inhibitor that can activate Nodal signaling only at very high doses

PubMed Central

Levine, Ariel J.; Levine, Zachary J.; Brivanlou, Ali H.

2013-01-01

Within the TGF-β superfamily, there are approximately forty ligands divided into two major branches: the TGF-β/Activin/Nodal ligands and the BMP/GDF ligands. We studied the ligand GDF3 and found that it inhibits signaling by its co-family members, the BMPs; however, GDF3 has been described by others to have Nodal-like activity. Here, we show that GDF3 can activate Nodal signaling, but only at very high doses and only upon mRNA over-expression. In contrast, GDF3 inhibits BMP signaling upon over-expression of GDF3 mRNA, as recombinant protein, and regardless of its dose. We therefore further characterized the mechanism through which GDF3 protein acts as a specific BMP inhibitor and found that the BMP inhibitory activity of GDF3 resides redundantly in the unprocessed, predominant form and in the mature form of the protein. These results confirm and extend the activity that we described for GDF3 and illuminate the experimental basis for the different observations of others. We suggest that GDF3 is either a bi-functional TGF-β ligand, or, more likely, that it is a BMP inhibitor that can artificially activate Nodal signaling under non-physiological conditions. PMID:18823971

Fatty Acid Profile, Phenolics and Flavonoids Contents in Olea europaea L. Callus Culture cv. cornicabra.

PubMed

Rodríguez-Hernandez, Ludwi; Nájera-Gomez, Humberto; Luján-Hidalgo, Maria Celína; Ruiz-Lau, Nancy; Lecona-Guzmán, Carlos Alberto; Abud-Archila, Miguel; Ruíz-Valdiviezo, Víctor Manuel; Gutiérrez-Miceli, Federico Antonio

2018-05-01

Olive trees are one of the most important oil crops in the world due to the sensorial and nutritional characteristics of olive oil, such as lipid composition and antioxidant content, and the medicinal properties of its leaves. In this paper, callus formation was induced using nodal segments of olive tree (Olea europaea cv. cornicabra) as explants. Fatty acid profile, total phenolic compounds and total flavonoid compounds were determined in callus culture after 15 weeks and compared with leaf and nodal segments tissues. There was no statistical difference in phenolic compounds among leaf, nodal segments and callus culture, whereas flavonoid compounds were higher in leaf. Fatty acid profile was similar in leaf, nodal segments and callus culture and was constituted by hexadecanoic acid, octadecanoic acid, cis-9-octadecenoic acid, cis-9,12-octadecadienoic acid, cis-9,12,15-octadecatrienoic acid. Hexadecanoic acid was the main fatty acid in callus, leaf and nodal segments with 35.0, 39.0 and 40.0% (w/w), of the lipid composition, respectively. With this paper, it is being reported for the first time the capacity of callus culture to accumulate fatty acids. Our results could serve to continue studying the production of fatty acids in callus cultivation as a biotechnological tool to improve different olive cultivars.

Nodal-chain metals.

PubMed

Bzdušek, Tomáš; Wu, QuanSheng; Rüegg, Andreas; Sigrist, Manfred; Soluyanov, Alexey A

2016-10-06

The band theory of solids is arguably the most successful theory of condensed-matter physics, providing a description of the electronic energy levels in various materials. Electronic wavefunctions obtained from the band theory enable a topological characterization of metals for which the electronic spectrum may host robust, topologically protected, fermionic quasiparticles. Many of these quasiparticles are analogues of the elementary particles of the Standard Model, but others do not have a counterpart in relativistic high-energy theories. A complete list of possible quasiparticles in solids is lacking, even in the non-interacting case. Here we describe the possible existence of a hitherto unrecognized type of fermionic excitation in metals. This excitation forms a nodal chain-a chain of connected loops in momentum space-along which conduction and valence bands touch. We prove that the nodal chain is topologically distinct from previously reported excitations. We discuss the symmetry requirements for the appearance of this excitation and predict that it is realized in an existing material, iridium tetrafluoride (IrF 4 ), as well as in other compounds of this class of materials. Using IrF 4 as an example, we provide a discussion of the topological surface states associated with the nodal chain. We argue that the presence of the nodal-chain fermions will result in anomalous magnetotransport properties, distinct from those of materials exhibiting previously known excitations.

The prognostic value of node status in different breast cancer subtypes

PubMed Central

Hou, Xin-Wei; Chi, Jiang-Rui; Ge, Jie; Wang, Xin; Cao, Xu-Chen

2017-01-01

Nodal metastases and breast cancer subtypes (BCS) are both well-recognized prognostic indicators. However, the association between nodal metastases and BCS, and the prognostic value of nodal metastases in different BCS are still remains unclear. Our aim was to investigate the association between nodal metastases and BCS, and the prognostic value of nodal metastases in the different BCS. We found that the breast cancer subtype was closely associated with the pN stage. pN stage and breast cancer subtype were significantly associated with disease-free survival. The subgroup analysis showed that the patients in higher pN stage had a poor outcome than patients in lower pN stage in each breast cancer subtype. Furthermore, when the analysis was stratified by breast cancer subtype, we found that even in the same pN stage (pN0-pN2), there was significant survival difference among patients in different BCS, and Luminal A breast cancer patients had the best survival outcome. However, there were no significant survival difference between Luminal A patients and other breast cancer subtype when patients in pN3 stage. Thus, our study suggested that both lymph node status and molecular subtype played important roles in the outcome of breast cancer patients and they cannot replace each other. PMID:27999188

Bcl-2 and BLIMP-1 expression predict worse prognosis in gastric diffuse large B cell lymphoma (DLCBL) while other markers for nodal DLBCL are not useful.

PubMed

Martin-Arruti, Maialen; Vaquero, Manuel; Díaz de Otazu, Ramón; Zabalza, Iñaki; Ballesteros, Javier; Roncador, Giovanna; García-Orad, Africa

2012-04-01

Previous studies have identified clinicopathological and immunohistochemical differences among diffuse large B cell lymphomas (DLBCL) as a function of disease location. Nevertheless, there is a continuing tendency to generalize the prognostic value of various identified markers without taking into account tumour site. Accordingly, we analysed the prognostic value of several of the immunohistochemical markers that have been proposed for nodal DLBCL in a group of patients with gastric DLBCL. Using histochemical methods, CD10, Bcl-6, Gcet1, MUM-1, Bcl-2 and BLIMP-1 expression was investigated in 43 cases of gastric DBLCL. As in nodal DLBCLs, expression of BLIMP-1, and of Bcl-2 in non-germinal centre B cell-like (non-GCB) patients, was associated with a worse prognosis. However, unlike nodal DBLCL, there was no significant association of prognosis with expression of CD10, Bcl-6, Gcet1 or MUM-1, or with categorization according to Hans or Muris algorithms. Although most markers of prognosis in nodal DLBCL are not useful indicators for gastric DLBCL, Bcl-2 or BLIMP-1 expression does correlate with worse prognosis. These data support the notion that clinicopathological features in DLBCL vary according to the disease location. © 2012 Blackwell Publishing Ltd.

Practice patterns for the radical treatment of nasopharyngeal cancer by head and neck oncologists in the United Kingdom.

PubMed

Petkar, Imran; Bhide, Shreerang; Newbold, Kate; Harrington, Kevin; Nutting, Chris

2018-05-01

Advances in radiation delivery, imaging techniques, and chemotherapy have significantly improved treatment options for non-metastatic nasopharyngeal cancers (NPC). However, their impact on the practice in the United Kingdom (UK), where this tumour is rare, is unknown. This study examined the current attitudes of UK head and neck oncologists to the treatment of NPC. UK head and neck oncologists representing 19/23 cancer networks were sent an invitation email with a personalised link to a web-based survey designed to identify the influence of tumour and nodal staging on current NPC management practices. 26/42 (61%) of clinicians responded. Induction chemotherapy followed by concomitant chemoradiation was the treatment of choice for Stage III (69%) and IVa/b (96%), with cisplatin and 5-fluorouracil combination being the most commonly used induction chemotherapy regimen (88%). 16 centres (61%) used a geometric approach, adding variable margins of 0-10 mm to the gross tumour volume to define their therapeutic dose clinical target volume. 54% of respondents used 3 radiotherapy (RT) prescription doses to treat NPC. Retropharyngeal nodal region irradiation policy was inconsistent, with nearly one-quarter treating the entire group to a radical dose. Significant heterogeneity currently exists in the RT practice of NPC in the UK. A consensus regarding the optimal curative, function-sparing treatment paradigm for NPC is necessary to ensure cancer survivors have satisfactory long-term health-related quality of life. Advances in knowledge: This is the first study to highlight the significant variation in RT practice of NPC in the UK.

Diagnostic Challenges in Prostate Cancer and 68Ga-PSMA PET Imaging: A Game Changer?

PubMed

Zaman, Maseeh uz; Fatima, Nosheen; Zaman, Areeba; Sajid, Mahwsih; Zaman, Unaiza; Zaman, Sidra

2017-10-26

Prostate cancer (PC) is the most frequent solid tumor in men and the third most common cause of cancer mortality among men in developed countries. Current imaging modalities like ultrasound (US), computerized tomography (CT), magnetic resonance imaging (MRI) and choline based positron emission (PET) tracing have disappointing sensitivity for detection of nodal metastasis and small tumor recurrence. This poses a diagnostic challenge in staging of intermediate to high risk PC and restaging of patients with biochemical recurrence (PSA >0.2 ng/ml). Gallium-68 labeled prostate specific membrane antigen (68Ga-PSMA) PET imaging has now emerged with a higher diagnostic yield. 68Ga-PSMA PET/CT or PET/MRI can be expected to offer a one-stop-shop for staging and restaging of PC. PSMA ligands labeled with alpha and beta emitters have also shown promising therapeutic efficacy for nodal, bone and visceral metastasis. Therefore a PSMA based theranostics approach for detection, staging, treatment, and follow-up of PC would appear to be highly valuable to achieve personalized PC treatment. Creative Commons Attribution License

Using a Large Scale Computational Model to Study the Effect of Longitudinal and Radial Electrical Coupling in the Cochlea

NASA Astrophysics Data System (ADS)

Mistrík, Pavel; Ashmore, Jonathan

2009-02-01

We describe a large scale computational model of electrical current flow in the cochlea which is constructed by a flexible Modified Nodal Analysis algorithm to incorporate electrical components representing hair cells and the intercellular radial and longitudinal current flow. The model is used as a laboratory to study the effects of changing longitudinal gap junctional coupling, and shows the way in which cochlear microphonic spreads and tuning is affected. The process for incorporating mechanical longitudinal coupling and feedback is described. We find a difference in tuning and attenuation depending on whether longitudinal or radial couplings are altered.

Brady's Geothermal Field Nodal Seismometers Metadata

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

Lesley Parker

Metadata for the nodal seismometer array deployed at the POROTOMO's Natural Laboratory in Brady Hot Spring, Nevada during the March 2016 testing. Metadata includes location and timing for each instrument as well as file lists of data to be uploaded in a separate submission.

Nodal-line dynamics via exact polynomial solutions for coherent waves traversing aberrated imaging systems.

PubMed

Paganin, David M; Beltran, Mario A; Petersen, Timothy C

2018-03-01

We obtain exact polynomial solutions for two-dimensional coherent complex scalar fields propagating through arbitrary aberrated shift-invariant linear imaging systems. These solutions are used to model nodal-line dynamics of coherent fields output by such systems.

Detection of lymph node metastases in pediatric and adolescent/young adult sarcoma: Sentinel lymph node biopsy versus fludeoxyglucose positron emission tomography imaging-A prospective trial.

PubMed

Wagner, Lars M; Kremer, Nathalie; Gelfand, Michael J; Sharp, Susan E; Turpin, Brian K; Nagarajan, Rajaram; Tiao, Gregory M; Pressey, Joseph G; Yin, Julie; Dasgupta, Roshni

2017-01-01

Lymph node metastases are an important cause of treatment failure for pediatric and adolescent/young adult (AYA) sarcoma patients. Nodal sampling is recommended for certain sarcoma subtypes that have a predilection for lymphatic spread. Sentinel lymph node biopsy (SLNB) may improve the diagnostic yield of nodal sampling, particularly when single-photon emission computed tomography/computed tomography (SPECT-CT) is used to facilitate anatomic localization. Functional imaging with positron emission tomography/computed tomography (PET-CT) is increasingly used for sarcoma staging and is a less invasive alternative to SLNB. To assess the utility of these 2 staging methods, this study prospectively compared SLNB plus SPECT-CT with PET-CT for the identification of nodal metastases in pediatric and AYA patients. Twenty-eight pediatric and AYA sarcoma patients underwent SLNB with SPECT-CT. The histological findings of the excised lymph nodes were then correlated with preoperative PET-CT imaging. A median of 2.4 sentinel nodes were sampled per patient. No wound infections or chronic lymphedema occurred. SLNB identified tumors in 7 of the 28 patients (25%), including 3 patients who had normal PET-CT imaging of the nodal basin. In contrast, PET-CT demonstrated hypermetabolic regional nodes in 14 patients, and this resulted in a positive predictive value of only 29%. The sensitivity and specificity of PET-CT for detecting histologically confirmed nodal metastases were only 57% and 52%, respectively. SLNB can safely guide the rational selection of nodes for biopsy in pediatric and AYA sarcoma patients and can identify therapy-changing nodal disease not appreciated with PET-CT. Cancer 2017;155-160. © 2016 American Cancer Society. © 2016 American Cancer Society.

An approach to model reactor core nodalization for deterministic safety analysis

NASA Astrophysics Data System (ADS)

Salim, Mohd Faiz; Samsudin, Mohd Rafie; Mamat @ Ibrahim, Mohd Rizal; Roslan, Ridha; Sadri, Abd Aziz; Farid, Mohd Fairus Abd

2016-01-01

Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to be employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH1.6, stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D® computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M.

Comparison of cryoablation with 3D mapping versus conventional mapping for the treatment of atrioventricular re-entrant tachycardia and right-sided paraseptal accessory pathways.

PubMed

Russo, Mario S; Drago, Fabrizio; Silvetti, Massimo S; Righi, Daniela; Di Mambro, Corrado; Placidi, Silvia; Prosperi, Monica; Ciani, Michele; Naso Onofrio, Maria T; Cannatà, Vittorio

2016-06-01

Aim Transcatheter cryoablation is a well-established technique for the treatment of atrioventricular nodal re-entry tachycardia and atrioventricular re-entry tachycardia in children. Fluoroscopy or three-dimensional mapping systems can be used to perform the ablation procedure. The aim of this study was to compare the success rate of cryoablation procedures for the treatment of right septal accessory pathways and atrioventricular nodal re-entry circuits in children using conventional or three-dimensional mapping and to evaluate whether three-dimensional mapping was associated with reduced patient radiation dose compared with traditional mapping. In 2013, 81 children underwent transcatheter cryoablation at our institution, using conventional mapping in 41 children - 32 atrioventricular nodal re-entry tachycardia and nine atrioventricular re-entry tachycardia - and three-dimensional mapping in 40 children - 24 atrioventricular nodal re-entry tachycardia and 16 atrioventricular re-entry tachycardia. Using conventional mapping, the overall success rate was 78.1 and 66.7% in patients with atrioventricular nodal re-entry tachycardia or atrioventricular re-entry tachycardia, respectively. Using three-dimensional mapping, the overall success rate was 91.6 and 75%, respectively (p=ns). The use of three-dimensional mapping was associated with a reduction in cumulative air kerma and cumulative air kerma-area product of 76.4 and 67.3%, respectively (p<0.05). The use of three-dimensional mapping compared with the conventional fluoroscopy-guided method for cryoablation of right septal accessory pathways and atrioventricular nodal re-entry circuits in children was associated with a significant reduction in patient radiation dose without an increase in success rate.

Incidental Prophylactic Nodal Irradiation and Patterns of Nodal Relapse in Inoperable Early Stage NSCLC Patients Treated With SBRT: A Case-Matched Analysis

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

Lao, Louis; Department of Radiation Oncology, Auckland City Hospital, Auckland; Hope, Andrew J.

2014-09-01

Purpose: Reported rates of non-small cell lung cancer (NSCLC) nodal failure following stereotactic body radiation therapy (SBRT) are lower than those reported in the surgical series when matched for stage. We hypothesized that this effect was due to incidental prophylactic nodal irradiation. Methods and Materials: A prospectively collected group of medically inoperable early stage NSCLC patients from 2004 to 2010 was used to identify cases with nodal relapses. Controls were matched to cases, 2:1, controlling for tumor volume (ie, same or greater) and tumor location (ie, same lobe). Reference (normalized to equivalent dose for 2-Gy fractions [EQD2]) point doses atmore » the ipsilateral hilum and carina, demographic data, and clinical outcomes were extracted from the medical records. Univariate conditional logistical regression analyses were performed with variables of interest. Results: Cases and controls were well matched except for size. The controls, as expected, had larger gross tumor volumes (P=.02). The mean ipsilateral hilar doses were 9.6 Gy and 22.4 Gy for cases and controls, respectively (P=.014). The mean carinal doses were 7.0 Gy and 9.2 Gy, respectively (P=.13). Mediastinal nodal relapses, with and without ipsilateral hilar relapse, were associated with mean ipsilateral hilar doses of 3.6 Gy and 19.8 Gy, respectively (P=.01). The conditional density plot appears to demonstrate an inverse dose-effect relationship between ipsilateral hilar normalized total dose and risk of ipsilateral hilar relapse. Conclusions: Incidental hilar dose greater than 20 Gy is significantly associated with fewer ipsilateral hilar relapses in inoperable early stage NSCLC patients treated with SBRT.« less

Graph Theoretical Analysis of Functional Brain Networks: Test-Retest Evaluation on Short- and Long-Term Resting-State Functional MRI Data

PubMed Central

Wang, Jin-Hui; Zuo, Xi-Nian; Gohel, Suril; Milham, Michael P.; Biswal, Bharat B.; He, Yong

2011-01-01

Graph-based computational network analysis has proven a powerful tool to quantitatively characterize functional architectures of the brain. However, the test-retest (TRT) reliability of graph metrics of functional networks has not been systematically examined. Here, we investigated TRT reliability of topological metrics of functional brain networks derived from resting-state functional magnetic resonance imaging data. Specifically, we evaluated both short-term (<1 hour apart) and long-term (>5 months apart) TRT reliability for 12 global and 6 local nodal network metrics. We found that reliability of global network metrics was overall low, threshold-sensitive and dependent on several factors of scanning time interval (TI, long-term>short-term), network membership (NM, networks excluding negative correlations>networks including negative correlations) and network type (NT, binarized networks>weighted networks). The dependence was modulated by another factor of node definition (ND) strategy. The local nodal reliability exhibited large variability across nodal metrics and a spatially heterogeneous distribution. Nodal degree was the most reliable metric and varied the least across the factors above. Hub regions in association and limbic/paralimbic cortices showed moderate TRT reliability. Importantly, nodal reliability was robust to above-mentioned four factors. Simulation analysis revealed that global network metrics were extremely sensitive (but varying degrees) to noise in functional connectivity and weighted networks generated numerically more reliable results in compared with binarized networks. For nodal network metrics, they showed high resistance to noise in functional connectivity and no NT related differences were found in the resistance. These findings provide important implications on how to choose reliable analytical schemes and network metrics of interest. PMID:21818285

Identification of nodal tissue in the living heart using rapid scanning fiber-optics confocal microscopy and extracellular fluorophores.

PubMed

Huang, Chao; Kaza, Aditya K; Hitchcock, Robert W; Sachse, Frank B

2013-09-01

Risks associated with pediatric reconstructive heart surgery include injury of the sinoatrial node (SAN) and atrioventricular node (AVN), requiring cardiac rhythm management using implantable pacemakers. These injuries are the result of difficulties in identifying nodal tissues intraoperatively. Here we describe an approach based on confocal microscopy and extracellular fluorophores to quantify tissue microstructure and identify nodal tissue. Using conventional 3-dimensional confocal microscopy we investigated the microstructural arrangement of SAN, AVN, and atrial working myocardium (AWM) in fixed rat heart. AWM exhibited a regular striated arrangement of the extracellular space. In contrast, SAN and AVN had an irregular, reticulated arrangement. AWM, SAN, and AVN tissues were beneath a thin surface layer of tissue that did not obstruct confocal microscopic imaging. Subsequently, we imaged tissues in living rat hearts with real-time fiber-optics confocal microscopy. Fiber-optics confocal microscopy images resembled images acquired with conventional confocal microscopy. We investigated spatial regularity of tissue microstructure from Fourier analysis and second-order image moments. Fourier analysis of fiber-optics confocal microscopy images showed that the spatial regularity of AWM was greater than that of nodal tissues (37.5 ± 5.0% versus 24.3 ± 3.9% for SAN and 23.8 ± 3.7% for AVN; P<0.05). Similar differences of spatial regularities were revealed from second-order image moments (50.0 ± 7.3% for AWM versus 29.3 ± 6.7% for SAN and 27.3 ± 5.5% for AVN; P<0.05). The study demonstrates feasibility of identifying nodal tissue in living heart using extracellular fluorophores and fiber-optics confocal microscopy. Application of the approach in pediatric reconstructive heart surgery may reduce risks of injuring nodal tissues.

Decision Trees Predicting Tumor Shrinkage for Head and Neck Cancer: Implications for Adaptive Radiotherapy.

PubMed

Surucu, Murat; Shah, Karan K; Mescioglu, Ibrahim; Roeske, John C; Small, William; Choi, Mehee; Emami, Bahman

2016-02-01

To develop decision trees predicting for tumor volume reduction in patients with head and neck (H&N) cancer using pretreatment clinical and pathological parameters. Forty-eight patients treated with definitive concurrent chemoradiotherapy for squamous cell carcinoma of the nasopharynx, oropharynx, oral cavity, or hypopharynx were retrospectively analyzed. These patients were rescanned at a median dose of 37.8 Gy and replanned to account for anatomical changes. The percentages of gross tumor volume (GTV) change from initial to rescan computed tomography (CT; %GTVΔ) were calculated. Two decision trees were generated to correlate %GTVΔ in primary and nodal volumes with 14 characteristics including age, gender, Karnofsky performance status (KPS), site, human papilloma virus (HPV) status, tumor grade, primary tumor growth pattern (endophytic/exophytic), tumor/nodal/group stages, chemotherapy regimen, and primary, nodal, and total GTV volumes in the initial CT scan. The C4.5 Decision Tree induction algorithm was implemented. The median %GTVΔ for primary, nodal, and total GTVs was 26.8%, 43.0%, and 31.2%, respectively. Type of chemotherapy, age, primary tumor growth pattern, site, KPS, and HPV status were the most predictive parameters for primary %GTVΔ decision tree, whereas for nodal %GTVΔ, KPS, site, age, primary tumor growth pattern, initial primary GTV, and total GTV volumes were predictive. Both decision trees had an accuracy of 88%. There can be significant changes in primary and nodal tumor volumes during the course of H&N chemoradiotherapy. Considering the proposed decision trees, radiation oncologists can select patients predicted to have high %GTVΔ, who would theoretically gain the most benefit from adaptive radiotherapy, in order to better use limited clinical resources. © The Author(s) 2015.

On the correct representation of bending and axial deformation in the absolute nodal coordinate formulation with an elastic line approach

NASA Astrophysics Data System (ADS)

Gerstmayr, Johannes; Irschik, Hans

2008-12-01

In finite element methods that are based on position and slope coordinates, a representation of axial and bending deformation by means of an elastic line approach has become popular. Such beam and plate formulations based on the so-called absolute nodal coordinate formulation have not yet been verified sufficiently enough with respect to analytical results or classical nonlinear rod theories. Examining the existing planar absolute nodal coordinate element, which uses a curvature proportional bending strain expression, it turns out that the deformation does not fully agree with the solution of the geometrically exact theory and, even more serious, the normal force is incorrect. A correction based on the classical ideas of the extensible elastica and geometrically exact theories is applied and a consistent strain energy and bending moment relations are derived. The strain energy of the solid finite element formulation of the absolute nodal coordinate beam is based on the St. Venant-Kirchhoff material: therefore, the strain energy is derived for the latter case and compared to classical nonlinear rod theories. The error in the original absolute nodal coordinate formulation is documented by numerical examples. The numerical example of a large deformation cantilever beam shows that the normal force is incorrect when using the previous approach, while a perfect agreement between the absolute nodal coordinate formulation and the extensible elastica can be gained when applying the proposed modifications. The numerical examples show a very good agreement of reference analytical and numerical solutions with the solutions of the proposed beam formulation for the case of large deformation pre-curved static and dynamic problems, including buckling and eigenvalue analysis. The resulting beam formulation does not employ rotational degrees of freedom and therefore has advantages compared to classical beam elements regarding energy-momentum conservation.

An approach to model reactor core nodalization for deterministic safety analysis

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

Salim, Mohd Faiz, E-mail: mohdfaizs@tnb.com.my; Samsudin, Mohd Rafie, E-mail: rafies@tnb.com.my; Mamat Ibrahim, Mohd Rizal, E-mail: m-rizal@nuclearmalaysia.gov.my

Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to bemore » employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH{sub 1.6}, stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D{sup ®} computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M.« less

Genetic Analysis Reveals a Hierarchy of Interactions between Polycystin-Encoding Genes and Genes Controlling Cilia Function during Left-Right Determination

PubMed Central

Grimes, Daniel T.; Keynton, Jennifer L.; Buenavista, Maria T.; Jin, Xingjian; Patel, Saloni H.; Kyosuke, Shinohara; Williams, Debbie J.; Hamada, Hiroshi; Hussain, Rohanah; Nauli, Surya M.; Norris, Dominic P.

2016-01-01

During mammalian development, left-right (L-R) asymmetry is established by a cilia-driven leftward fluid flow within a midline embryonic cavity called the node. This ‘nodal flow’ is detected by peripherally-located crown cells that each assemble a primary cilium which contain the putative Ca2+ channel PKD2. The interaction of flow and crown cell cilia promotes left side-specific expression of Nodal in the lateral plate mesoderm (LPM). Whilst the PKD2-interacting protein PKD1L1 has also been implicated in L-R patterning, the underlying mechanism by which flow is detected and the genetic relationship between Polycystin function and asymmetric gene expression remains unknown. Here, we characterize a Pkd1l1 mutant line in which Nodal is activated bilaterally, suggesting that PKD1L1 is not required for LPM Nodal pathway activation per se, but rather to restrict Nodal to the left side downstream of nodal flow. Epistasis analysis shows that Pkd1l1 acts as an upstream genetic repressor of Pkd2. This study therefore provides a genetic pathway for the early stages of L-R determination. Moreover, using a system in which cultured cells are supplied artificial flow, we demonstrate that PKD1L1 is sufficient to mediate a Ca2+ signaling response after flow stimulation. Finally, we show that an extracellular PKD domain within PKD1L1 is crucial for PKD1L1 function; as such, destabilizing the domain causes L-R defects in the mouse. Our demonstration that PKD1L1 protein can mediate a response to flow coheres with a mechanosensation model of flow sensation in which the force of fluid flow drives asymmetric gene expression in the embryo. PMID:27272319

A thermal NO(x) prediction model - Scalar computation module for CFD codes with fluid and kinetic effects

NASA Technical Reports Server (NTRS)

Mcbeath, Giorgio; Ghorashi, Bahman; Chun, Kue

1993-01-01

A thermal NO(x) prediction model is developed to interface with a CFD, k-epsilon based code. A converged solution from the CFD code is the input to the postprocessing model for prediction of thermal NO(x). The model uses a decoupled analysis to estimate the equilibrium level of (NO(x))e which is the constant rate limit. This value is used to estimate the flame (NO(x)) and in turn predict the rate of formation at each node using a two-step Zeldovich mechanism. The rate is fixed on the NO(x) production rate plot by estimating the time to reach equilibrium by a differential analysis based on the reaction: O + N2 = NO + N. The rate is integrated in the nonequilibrium time space based on the residence time at each node in the computational domain. The sum of all nodal predictions yields the total NO(x) level.

Calibration-free portable Young's-modulus tester with isolated langasite oscillator.

PubMed

Ogi, Hirotsugu; Sakamoto, Yuto; Hirao, Masahiko

2014-09-01

A ballpoint-pen-type portable ultrasonic oscillator is developed for quantitative measurement of Young's modulus on a solid. It consists of an electrodeless rod-shaped langasite oscillator with a tungsten-carbide spherical-shaped tip at the end, permanent magnets for making a constant force at the contact interface, and antennas for exciting and detecting the longitudinal vibration contactlessly. The resonance frequency of the oscillator is changed by contact with the specimen, reflecting Young's modulus of the specimen at the contact area. The langasite oscillator is supported at the nodal points so that its acoustical contact occurs only at the specimen, making a calibration-free measurement realistic. Young's moduli of various specimens were evaluated within 15% error just by touching the specimens with the probe. The error becomes smaller than 10% for lower Young-modulus materials (<∼150 GPa). Copyright © 2014 Elsevier B.V. All rights reserved.

Advanced nodal neutron diffusion method with space-dependent cross sections: ILLICO-VX

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

Rajic, H.L.; Ougouag, A.M.

1987-01-01

Advanced transverse integrated nodal methods for neutron diffusion developed since the 1970s require that node- or assembly-homogenized cross sections be known. The underlying structural heterogeneity can be accurately accounted for in homogenization procedures by the use of heterogeneity or discontinuity factors. Other (milder) types of heterogeneity, burnup-induced or due to thermal-hydraulic feedback, can be resolved by explicitly accounting for the spatial variations of material properties. This can be done during the nodal computations via nonlinear iterations. The new method has been implemented in the code ILLICO-VX (ILLICO variable cross-section method). Numerous numerical tests were performed. As expected, the convergence ratemore » of ILLICO-VX is lower than that of ILLICO, requiring approx. 30% more outer iterations per k/sub eff/ computation. The methodology has also been implemented as the NOMAD-VX option of the NOMAD, multicycle, multigroup, two- and three-dimensional nodal diffusion depletion code. The burnup-induced heterogeneities (space dependence of cross sections) are calculated during the burnup steps.« less

Universal heat conduction in Ce 1-xYb xCoIn 5: Evidence for robust nodal d-wave superconducting gap

DOE PAGES

Xu, Y.; Petrovic, C.; Dong, J. K.; ...

2016-02-01

In the heavy-fermion superconductor Ce 1-xYb xCoIn 5, Yb doping was reported to cause a possible change from nodal d-wave superconductivity to a fully gapped d-wave molecular superfluid of composite pairs near x ≈ 0.07 (nominal value x nom = 0.2). Here we present systematic thermal conductivity measurements on Ce 1-xYb xCoIn 5 (x = 0.013, 0.084, and 0.163) single crystals. The observed finite residual linear term κ 0/T is insensitive to Yb doping, verifying the universal heat conduction of the nodal d-wave superconducting gap in Ce 1-xYb xCoIn 5. Similar universal heat conduction is also observed in the CeCo(Inmore » 1–yCd y) 5 system. Furthermore, these results reveal a robust nodal d-wave gap in CeCoIn 5 upon Yb or Cd doping.« less

Disappearance of nodal gap across the insulator-superconductor transition in a copper-oxide superconductor.

PubMed

Peng, Yingying; Meng, Jianqiao; Mou, Daixiang; He, Junfeng; Zhao, Lin; Wu, Yue; Liu, Guodong; Dong, Xiaoli; He, Shaolong; Zhang, Jun; Wang, Xiaoyang; Peng, Qinjun; Wang, Zhimin; Zhang, Shenjin; Yang, Feng; Chen, Chuangtian; Xu, Zuyan; Lee, T K; Zhou, X J

2013-01-01

The parent compound of the copper-oxide high-temperature superconductors is a Mott insulator. Superconductivity is realized by doping an appropriate amount of charge carriers. How a Mott insulator transforms into a superconductor is crucial in understanding the unusual physical properties of high-temperature superconductors and the superconductivity mechanism. Here we report high-resolution angle-resolved photoemission measurement on heavily underdoped Bi₂Sr₂-xLaxCuO(₆+δ) system. The electronic structure of the lightly doped samples exhibit a number of characteristics: existence of an energy gap along the nodal direction, d-wave-like anisotropic energy gap along the underlying Fermi surface, and coexistence of a coherence peak and a broad hump in the photoemission spectra. Our results reveal a clear insulator-superconductor transition at a critical doping level of ~0.10 where the nodal energy gap approaches zero, the three-dimensional antiferromagnetic order disappears, and superconductivity starts to emerge. These observations clearly signal a close connection between the nodal gap, antiferromagnetism and superconductivity.

Topological Phase Transitions in Line-nodal Superconductors

NASA Astrophysics Data System (ADS)

Cho, Gil Young; Han, Sangeun; Moon, Eun-Gook

Fathoming interplay between symmetry and topology of many-electron wave-functions deepens our understanding in quantum nature of many particle systems. Topology often protects zero-energy excitation, and in a certain class, symmetry is intrinsically tied to the topological protection. Namely, unless symmetry is broken, topological nature is intact. We study one specific case of such class, symmetry-protected line-nodal superconductors in three spatial dimensions (3d). Mismatch between phase spaces of order parameter fluctuation and line-nodal fermion excitation induces an exotic universality class in a drastic contrast to one of the conventional ϕ4 theory in 3d. Hyper-scaling violation and relativistic dynamic scaling with unusually large quantum critical region are main characteristics, and their implication in experiments is discussed. For example, continuous phase transition out of line-nodal superconductors has a linear phase boundary in a temperature-tuning parameter phase-diagram. This work was supported by the Brain Korea 21 PLUS Project of Korea Government and KAIST start-up funding.

Bifurcation behaviors of synchronized regions in logistic map networks with coupling delay

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

Tang, Longkun, E-mail: tomlk@hqu.edu.cn, E-mail: xqwu@whu.edu.cn; Wu, Xiaoqun, E-mail: tomlk@hqu.edu.cn, E-mail: xqwu@whu.edu.cn; Lu, Jun-an, E-mail: jalu@whu.edu.cn

2015-03-15

Network synchronized regions play an extremely important role in network synchronization according to the master stability function framework. This paper focuses on network synchronous state stability via studying the effects of nodal dynamics, coupling delay, and coupling way on synchronized regions in Logistic map networks. Theoretical and numerical investigations show that (1) network synchronization is closely associated with its nodal dynamics. Particularly, the synchronized region bifurcation points through which the synchronized region switches from one type to another are in good agreement with those of the uncoupled node system, and chaotic nodal dynamics can greatly impede network synchronization. (2) Themore » coupling delay generally impairs the synchronizability of Logistic map networks, which is also dominated by the parity of delay for some nodal parameters. (3) A simple nonlinear coupling facilitates network synchronization more than the linear one does. The results found in this paper will help to intensify our understanding for the synchronous state stability in discrete-time networks with coupling delay.« less

The role of nodal and internodal responses in gravitropism and autotropism in Galium aparine L

NASA Technical Reports Server (NTRS)

Heathcote, D. G.; Brown, A. H. (Principal Investigator)

1987-01-01

This time course and location of gravitropically induced curvatures in stems of goosegrass (Gallium aparine L.), a member of the Rubiaceae, have been investigated. In the early stages of the response (0-5 h), curvature develops throughout the growing region, and is followed by an autotropic straightening which affects the internodes only, leading to the production of essentially straight internodes some 15 h after the onset of gravistimulation. Curvatures developing in the nodal regions, however, continue to increase over this period, and are not subject to reversal by autotropism. The nodal curvatures are not entirely dependent on the presence of any other part of the plant, since marked curvatures can be induced in isolated nodal segments. This pattern of response leads ultimately to correction of the growth direction of the plant by means of curvature responses confined exclusively to the nodes, despite the initial participation of both nodes and internodes in the gravitropic reaction.

Nuclear movement regulated by non-Smad Nodal signaling via JNK is associated with Smad signaling during zebrafish endoderm specification.

PubMed

Hozumi, Shunya; Aoki, Shun; Kikuchi, Yutaka

2017-11-01

Asymmetric nuclear positioning is observed during animal development, but its regulation and significance in cell differentiation remain poorly understood. Using zebrafish blastulae, we provide evidence that nuclear movement towards the yolk syncytial layer, which comprises extraembryonic tissue, occurs in the first cells fated to differentiate into the endoderm. Nodal signaling is essential for nuclear movement, whereas nuclear envelope proteins are involved in movement through microtubule formation. Positioning of the microtubule-organizing center, which is proposed to be crucial for nuclear movement, is regulated by Nodal signaling and nuclear envelope proteins. The non-Smad JNK signaling pathway, which is downstream of Nodal signaling, regulates nuclear movement independently of the Smad pathway, and this nuclear movement is associated with Smad signal transduction toward the nucleus. Our study provides insight into the function of nuclear movement in Smad signaling toward the nucleus, and could be applied to the control of TGFβ signaling. © 2017. Published by The Company of Biologists Ltd.

Observation of nodal line in non-symmorphic topological semimetal InBi

DOE PAGES

Ekahana, Sandy Adhitia; Wu, Shu-Chun; Jiang, Juan; ...

2017-05-30

Topological nodal semimetal (TNS), characterized by its touching conduction and valence bands, is a newly discovered state of quantum matter which exhibits various exotic physical phenomena. Recently, a new type of TNS called topological nodal line semimetal (TNLS) is predicted where its conduction and valence band form a degenerate one-dimension line which is further protected by its crystal symmetry. In this work, we systematically investigated the bulk and surface electronic structure of the non-symmorphic, TNLS in InBi (which is also a type II Dirac semimetal) with strong spin–orbit coupling by using angle resolved photoemission spectroscopy. By tracking the crossing points of the bulk bands at the Brillouin zone boundary, we discovered the nodal-line feature along themore » $${{k}}_{{z}}$$ direction, in agreement with the ab initio calculations and confirmed it to be a new compound in the TNLS family. Our discovery provides a new material platform for the study of these exotic topological quantum phases and paves the way for possible future applications.« less

Spontaneous Currents in Superconducting Systems with Strong Spin-Orbit Coupling

NASA Astrophysics Data System (ADS)

Mironov, S.; Buzdin, A.

2017-02-01

We show that Rashba spin-orbit coupling at the interface between a superconductor and a ferromagnet should produce a spontaneous current in the atomic thickness region near the interface. This current is counterbalanced by the superconducting screening current flowing in the region of the width of the London penetration depth near the interface. Such a current-carrying state creates a magnetic field near the superconductor surface, generates a stray magnetic field outside the sample edges, changes the slope of the temperature dependence of the critical field Hc 3 , and may generate the spontaneous Abrikosov vortices near the interface.

Pelvic Nodal Dosing With Registration to the Prostate: Implications for High-Risk Prostate Cancer Patients Receiving Stereotactic Body Radiation Therapy

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

Kishan, Amar U., E-mail: aukishan@mednet.ucla.edu; Lamb, James M.; Jani, Shyam S.

2015-03-15

Purpose: To determine whether image guidance with rigid registration (RR) to intraprostatic markers (IPMs) yields acceptable coverage of the pelvic lymph nodes in the context of a stereotactic body radiation therapy (SBRT) regimen. Methods and Materials: Four to seven kilovoltage cone-beam CTs (CBCTs) from 12 patients with high-risk prostate cancer were analyzed, allowing approximation of an SBRT regimen. The nodal clinical target volume (CTV{sub N}) and bladder were contoured on all kilovoltage CBCTs. The V{sub 100} CTV{sub N}, expressed as a ratio to the same parameter on the initial plan, and the magnitude of translational shift between RR to themore » IPMs versus RR to the pelvic bones, were computed. The ability of a multimodality bladder filling protocol to minimize bladder height variation was assessed in a separate cohort of 4 patients. Results: Sixty-five CBCTs were assessed. The average V{sub 100} CTV{sub N} was 92.6%, but for a subset of 3 patients the average was 80.0%, compared with 97.8% for the others (P<.0001). The average overall and superior–inferior axis magnitudes of the bony-to-fiducial translations were significantly larger in the subgroup with suboptimal nodal coverage (8.1 vs 3.9 mm and 5.8 vs 2.4 mm, respectively; P<.0001). Relative bladder height changes were also significantly larger in the subgroup with suboptimal nodal coverage (42.9% vs 18.5%; P<.05). Use of a multimodality bladder-filling protocol minimized bladder height variation (P<.001). Conclusion: A majority of patients had acceptable nodal coverage after RR to IPMs, even when approximating SBRT. However, a subset of patients had suboptimal nodal coverage. These patients had large bony-to-fiducial translations and large variations in bladder height. Nodal coverage should be excellent if the superior–inferior axis bony-to-fiducial translation and the relative bladder height change (both easily measured on CBCT) are kept to a minimum. Implementation of a strict bladder filling protocol may achieve this goal.« less

Assessment of nodal involvement in non-small-cell lung cancer with 18F-FDG-PET/CT: mediastinal blood pool cut-off has the highest sensitivity and tumour SUVmax/2 has the highest specificity.

PubMed

Mallorie, Amy; Goldring, James; Patel, Anant; Lim, Eric; Wagner, Thomas

2017-08-01

Lymph node involvement in non-small-cell lung cancer (NSCLC) is a major factor in determining management and prognosis. We aimed to evaluate the accuracy of fluorine-18-fluorodeoxyglucose-PET/computed tomography (CT) for the assessment of nodal involvement in patients with NSCLC. In this retrospective study, we included 61 patients with suspected or confirmed resectable NSCLC over a 2-year period from April 2013 to April 2015. 221 nodes with pathological staging from surgery or endobronchial ultrasound-guided transbronchial needle aspiration were assessed using a nodal station-based analysis with original clinical reports and three different cut-offs: mediastinal blood pool (MBP), liver background and tumour standardized uptake value maximal (SUVmax)/2. Using nodal station-based analysis for activity more than tumour SUVmax/2, the sensitivity was 45%, the specificity was 89% and the negative predictive value (NPV) was 87%. For activity more than MBP, the sensitivity was 93%, the specificity was 72% and NPV was 98%. For activity more than liver background, the sensitivity was 83%, the specificity was 84% and NPV was 96%. Using a nodal staging-based analysis for accuracy at detecting N2/3 disease, for activity more than tumour SUVmax/2, the sensitivity was 59%, the specificity was 85% and NPV was 80%. For activity more than MBP, the sensitivity was 95%, the specificity was 61% and NPV was 96%. For activity more than liver background, the sensitivity was 86%, the specificity was 81% and NPV was 92%. Receiver-operating characteristic analysis showed the optimal nodal SUVmax to be more than 6.4 with a sensitivity of 45% and a specificity of 95%, with an area under the curve of 0.85. Activity more than MBP was the most sensitive cut-off with the highest sensitivity and NPV. Activity more than primary tumour SUVmax/2 was the most specific cut-off. Nodal SUVmax more than 6.4 has a high specificity of 95%.

Multiscale Methods for Nuclear Reactor Analysis

NASA Astrophysics Data System (ADS)

Collins, Benjamin S.

The ability to accurately predict local pin powers in nuclear reactors is necessary to understand the mechanisms that cause fuel pin failure during steady state and transient operation. In the research presented here, methods are developed to improve the local solution using high order methods with boundary conditions from a low order global solution. Several different core configurations were tested to determine the improvement in the local pin powers compared to the standard techniques, that use diffusion theory and pin power reconstruction (PPR). Two different multiscale methods were developed and analyzed; the post-refinement multiscale method and the embedded multiscale method. The post-refinement multiscale methods use the global solution to determine boundary conditions for the local solution. The local solution is solved using either a fixed boundary source or an albedo boundary condition; this solution is "post-refinement" and thus has no impact on the global solution. The embedded multiscale method allows the local solver to change the global solution to provide an improved global and local solution. The post-refinement multiscale method is assessed using three core designs. When the local solution has more energy groups, the fixed source method has some difficulties near the interface: however the albedo method works well for all cases. In order to remedy the issue with boundary condition errors for the fixed source method, a buffer region is used to act as a filter, which decreases the sensitivity of the solution to the boundary condition. Both the albedo and fixed source methods benefit from the use of a buffer region. Unlike the post-refinement method, the embedded multiscale method alters the global solution. The ability to change the global solution allows for refinement in areas where the errors in the few group nodal diffusion are typically large. The embedded method is shown to improve the global solution when it is applied to a MOX/LEU assembly interface, the fuel/reflector interface, and assemblies where control rods are inserted. The embedded method also allows for multiple solution levels to be applied in a single calculation. The addition of intermediate levels to the solution improves the accuracy of the method. Both multiscale methods considered here have benefits and drawbacks, but both can provide improvements over the current PPR methodology.

Review analysis of medullary carcinoma thyroid--15-year Indian experience.

PubMed

Dorairajan, N; Saravanakumar, P; Karthikeyan, S; Siddharth, D; Kanna, Srinivasulu

2005-08-01

To emphasize the importance of adequate primary surgery in cases of medullary carcinoma of the thyroid, 44 cases of treated medullary carcinoma of thyroid were retrospectively reviewed in Government General Hospital, Chennai between 1987 and 2002. Patients who underwent total thyroidectomy with only central compartment dissection were compared with those who had undergone total thyroidectomy with meticulous triple compartment (bilateral lateral and central groups) nodal dissection. The group of total thyroidectomy with only central compartment dissection had high rate of lymph nodal recurrence and persistent hypercalcitoninaemia when compared with the group of total thyroidectomy with meticulous triple compartment nodal dissection. (Chi square value 4.503 with p<0.05).

Oestrogen receptors, nodes and stage as predictors of post-recurrence survival in 457 breast cancer patients.

PubMed Central

Shek, L. L.; Godolphin, W.; Spinelli, J. J.

1987-01-01

The relationship to survival after first recurrence of oestrogen receptor (ER), nodal status and TNM stage at diagnosis, and treatment for advanced disease was studied in 457 females whose primary breast cancer was diagnosed in 1975 to 1981. Receptor concentration was the most important predictor of post-recurrence survival, with some additional information conveyed by nodal status. ER predicted survival after recurrence independently of nodal status, clinical stage or mode of therapy. Response to endocrine therapy is only a facet of the generally favourable prognosis of ER positive patients, rather than the sole explanation. PMID:3435707

Pre-gastrula expression of zebrafish extraembryonic genes

PubMed Central

2010-01-01

Background Many species form extraembryonic tissues during embryogenesis, such as the placenta of humans and other viviparous mammals. Extraembryonic tissues have various roles in protecting, nourishing and patterning embryos. Prior to gastrulation in zebrafish, the yolk syncytial layer - an extraembryonic nuclear syncytium - produces signals that induce mesoderm and endoderm formation. Mesoderm and endoderm precursor cells are situated in the embryonic margin, an external ring of cells along the embryo-yolk interface. The yolk syncytial layer initially forms below the margin, in a domain called the external yolk syncytial layer (E-YSL). Results We hypothesize that key components of the yolk syncytial layer's mesoderm and endoderm inducing activity are expressed as mRNAs in the E-YSL. To identify genes expressed in the E-YSL, we used microarrays to compare the transcription profiles of intact pre-gastrula embryos with pre-gastrula embryonic cells that we had separated from the yolk and yolk syncytial layer. This identified a cohort of genes with enriched expression in intact embryos. Here we describe our whole mount in situ hybridization analysis of sixty-eight of them. This includes ten genes with E-YSL expression (camsap1l1, gata3, znf503, hnf1ba, slc26a1, slc40a1, gata6, gpr137bb, otop1 and cebpa), four genes with expression in the enveloping layer (EVL), a superficial epithelium that protects the embryo (zgc:136817, zgc:152778, slc14a2 and elovl6l), three EVL genes whose expression is transiently confined to the animal pole (elovl6l, zgc:136359 and clica), and six genes with transient maternal expression (mtf1, wu:fj59f04, mospd2, rftn2, arrdc1a and pho). We also assessed the requirement of Nodal signaling for the expression of selected genes in the E-YSL, EVL and margin. Margin expression was Nodal dependent for all genes we tested, including the concentrated margin expression of an EVL gene: zgc:110712. All other instances of EVL and E-YSL expression that we tested were Nodal independent. Conclusion We have devised an effective strategy for enriching and identifying genes expressed in the E-YSL of pre-gastrula embryos. To our surprise, maternal genes and genes expressed in the EVL were also enriched by this strategy. A number of these genes are promising candidates for future functional studies on early embryonic patterning. PMID:20423468

New molecular insights into peripheral T cell lymphomas

PubMed Central

Pileri, Stefano A.; Piccaluga, Pier Paolo

2012-01-01

Peripheral T cell lymphomas (PTCLs) are heterogeneous neoplasms and represent about 12% of all lymphoid malignancies. They are often regarded as “orphan diseases,” a designation that does not reflect their real incidence but rather signifies the difficulties encountered in their classification, diagnosis, and treatment. Here we revise the current understanding of the pathobiological characteristics of the most common nodal PTCLs by focusing on the contribution given by high-throughput technologies and the identification of potential therapeutic targets proposed by translational studies. PMID:23023716

Controversies in the Management of Endometrial Carcinoma: An Update

PubMed Central

Mehasseb, Mohamed K.; Latimer, John A.

2012-01-01

Endometrial carcinoma is the commonest type of female genital tract malignancy in the developed countries. Endometrial carcinoma is usually confined to the uterus at the time of diagnosis and as such usually carries an excellent prognosis with high curability. Our understanding and management of endometrial cancer have continuously developed. Current controversies focus on screening and early detection, the extent of nodal surgery, and the changing roles of radiation therapy and chemotherapy and will be discussed in this paper. PMID:22518164

Simple vector bundles on a nodal Weierstrass cubic and quasi-trigonometric solutions of the classical Yang-Baxter equation

NASA Astrophysics Data System (ADS)

Burban, Igor; Galinat, Lennart; Stolin, Alexander

2017-11-01

In this paper we study the combinatorics of quasi-trigonometric solutions of the classical Yang-Baxter equation, arising from simple vector bundles on a nodal Weierstraß cubic. Dedicated to the memory of Petr Petrovich Kulish.

pN0(i+) Breast Cancer: Treatment Patterns, Locoregional Recurrence, and Survival Outcomes

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

Karam, Irene; Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver, BC; Lesperance, Maria F.

Purpose: To examine treatment patterns, recurrence, and survival outcomes in patients with pN0(i+) breast cancer. Methods and Materials: Subjects were 5999 women with AJCC (6th edition) pT1-3, pN0-N1a, M0 breast cancer diagnosed between 2003 and 2006. Of these, 4342 (72%) had pN0, 96 (2%) had pN0(i+), 349 (6%) had pNmic (micrometastases >0.2 mm to ≤2 mm), and 1212 (20%) had pN1a (1-3 positive macroscopic nodes) disease. Treatment characteristics and 5-year Kaplan-Meier local recurrence, regional recurrence (RR), locoregional recurrence (LRR), and overall survival were compared between nodal subgroups. Multivariable analysis was performed using Cox regression modeling. A 1:3 case-match analysis examinedmore » outcomes in pN0(i+) cases compared with pN0 controls matched for similar tumor and treatment characteristics. Results: Median follow-up was 4.8 years. Adjuvant systemic therapy use increased with nodal stage: 81%, 92%, 95%, and 94% in pN0, pN0(i+), pNmic, and pN1a disease, respectively (P<.001). Nodal radiation therapy (RT) use also increased with nodal stage: 1.7% in pN0, 27% in pN0(i+), 33% in pNmic, and 63% in pN1a cohorts (P<.001). Five-year Kaplan-Meier outcomes in pN0 versus pN0(i+) cases were as follows: local recurrence 1.7% versus 3.7% (P=.20), RR 0.5% versus 2.2% (P=.02), and LRR 2.1% versus 5.8% (P=.02). There were no RR events in 26 patients with pN0(i+) disease who received nodal RT and 2 RR events in 70 patients who did not receive nodal RT. On multivariable analysis, pN0(i+) was not associated with worse locoregional control or survival. On case-match analysis, LRR and overall survival were similar between pN0(i+) and matched pN0 counterparts. Conclusions: Nodal involvement with isolated tumor cells is not a significant prognostic factor for LRR or survival in this study's multivariable and case-match analyses. These data do not support the routine use of nodal RT in the setting of pN0(i+) disease. Prospective studies are needed to define optimal locoregional management for women with pN0(i+) breast cancer.« less

Analysis of nodal aberration properties in off-axis freeform system design.

PubMed

Shi, Haodong; Jiang, Huilin; Zhang, Xin; Wang, Chao; Liu, Tao

2016-08-20

Freeform surfaces have the advantage of balancing off-axis aberration. In this paper, based on the framework of nodal aberration theory (NAT) applied to the coaxial system, the third-order astigmatism and coma wave aberration expressions of an off-axis system with Zernike polynomial surfaces are derived. The relationship between the off-axis and surface shape acting on the nodal distributions is revealed. The nodal aberration properties of the off-axis freeform system are analyzed and validated by using full-field displays (FFDs). It has been demonstrated that adding Zernike terms, up to nine, to the off-axis system modifies the nodal locations, but the field dependence of the third-order aberration does not change. On this basis, an off-axis two-mirror freeform system with 500 mm effective focal length (EFL) and 300 mm entrance pupil diameter (EPD) working in long-wave infrared is designed. The field constant aberrations induced by surface tilting are corrected by selecting specific Zernike terms. The design results show that the nodes of third-order astigmatism and coma move back into the field of view (FOV). The modulation transfer function (MTF) curves are above 0.4 at 20 line pairs per millimeter (lp/mm) which meets the infrared reconnaissance requirement. This work provides essential insight and guidance for aberration correction in off-axis freeform system design.

Conserved and divergent expression patterns of markers of axial development in the laboratory opossum, Monodelphis domestica.

PubMed

Yoshida, Michio; Kajikawa, Eriko; Yamamoto, Daisuke; Kurokawa, Daisuke; Yonemura, Shigenobu; Kobayashi, Kensaku; Kiyonari, Hiroshi; Aizawa, Shinichi

2016-12-01

Previous comparative studies suggest that the requirement for Nodal in epiblast and hypoblast development is unique to mammalians. Expression of anterior visceral endoderm (AVE) genes in the visceral endoderm and of their orthologs in the hypoblast may be unique to mammalians and avians, and is absent in the reptilian hypoblast. Axis formation in reptiles is signaled by the formation of the posterior marginal epiblast (PME), which expresses a series of primitive streak genes. To assess the phylogenetic origin of Nodal and AVE gene expression and axis formation in amniotes, we examined marker gene expression in gray short-tailed opossum, a metatherian. Nodal was expressed in neither epiblast nor hypoblast of opossum embryos. No AVE genes were expressed in the opossum hypoblast. Attainment of polarity in the embryonic disk was signaled by Nodal, Wnt3a, Fgf8, and Bra expression in the PME at 8.5 days post-coitus. Nodal expression in epiblast or hypoblast may be unique to eutherians. AVE gene expression in visceral endoderm and hypoblast may have been independently acquired in eutherian and avian lineages. PME formation appears to be the event that signals axis formation in reptilian and metatherian embryos, and thus may be an ancestral characteristic of basal amniotes. Developmental Dynamics 245:1176-1188, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Human papillomavirus reduces the prognostic value of nodal involvement in tonsillar squamous cell carcinomas.

PubMed

Straetmans, Jos M J A A; Olthof, Nadine; Mooren, Jeroen J; de Jong, Jos; Speel, Ernst-Jan M; Kremer, Bernd

2009-10-01

Assessment of the prognostic value of nodal status in relation to human papillomavirus (HPV) status and the various treatment modalities in tonsillar squamous cell carcinomas (TSCC). Retrospective 5-year survival analysis. A 5-year follow-up of disease-free, disease-specific, and overall survival in a group of 81 patients with TSCC was conducted. The nodal status and integration of HPV-DNA in the genome (detected with fluorescence in situ hybridization) as prognostic indicators were examined while correcting for other clinical parameters (smoking habits, alcohol consumption, treatment modality, differentiation, TNM classification). Of TSCCs, 41% were positive for HPV type 16. In these TSCCs, the primary tumor was significantly smaller when compared to HVP-negative TSCCs (P = .04), whereas the percentage of cases with cervical metastases was identical. In the total population, it was not nodal involvement, but rather HPV manifestation, which was related to patient prognosis. Within the treatment modalities (surgery combined with radiotherapy and radiotherapy alone), neither nodal status nor HPV were prognostic indicators. Since a substantial percentage of TSCCs are HPV-positive and metastasizes to cervical lymph nodes in less advanced primary tumors, the N status is an unreliable prognostic indicator in TSCCs. HPV is only prognostically relevant in the total tumor population, but loses its value within patient groups receiving a single treatment modality. The value of HPV for prognosis of patients with TSCC requires further study.

Spin-polarized current in Zeeman-split d-wave superconductor/quantum wire junctions

NASA Astrophysics Data System (ADS)

Emamipour, Hamidreza

2016-06-01

We study a thin-film quantum wire/unconventional superconductor junction in the presence of an intrinsic exchange field for a d-wave symmetry of the superconducting order parameter. A strongly spin-polarized current is generated due to an interplay between Zeeman splitting of bands and the nodal structure of the superconducting order parameter. We show that strongly spin-polarized current is achievable for both metallic and tunnel junctions. This is because of the presence of a quantum wire (one-dimensional metal) in our junction. While in two-dimensional junctions with both conventional [F. Giazotto, F. Taddei, Phys. Rev. B 77 (2008) 132501] and unconventional [J. Linder, T. Yokoyama, Y. Tanaka, A. Sudbo, Phys. Rev. B 78 (2008) 014516] pairing states, highly spin polarized current takes place just for a tunnel junction. Also, the obtained spin-polarized current is tunable in sign and magnitude in terms of exchange field and applied bias voltage.

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

Anderson, Carryn M., E-mail: carryn-anderson@uiowa.edu; Chang, Tangel; Graham, Michael M.

Purpose: To evaluate dynamic [{sup 18}F]-fluorodeoxyglucose (FDG) uptake methodology as a post–radiation therapy (RT) response assessment tool, potentially enabling accurate tumor and therapy-related inflammation differentiation, improving the posttherapy value of FDG–positron emission tomography/computed tomography (FDG-PET/CT). Methods and Materials: We prospectively enrolled head-and-neck squamous cell carcinoma patients who completed RT, with scheduled 3-month post-RT FDG-PET/CT. Patients underwent our standard whole-body PET/CT scan at 90 minutes, with the addition of head-and-neck PET/CT scans at 60 and 120 minutes. Maximum standardized uptake values (SUV{sub max}) of regions of interest were measured at 60, 90, and 120 minutes. The SUV{sub max} slope between 60 and 120 minutes and changemore » of SUV{sub max} slope before and after 90 minutes were calculated. Data were analyzed by primary site and nodal site disease status using the Cox regression model and Wilcoxon rank sum test. Outcomes were based on pathologic and clinical follow-up. Results: A total of 84 patients were enrolled, with 79 primary and 43 nodal evaluable sites. Twenty-eight sites were interpreted as positive or equivocal (18 primary, 8 nodal, 2 distant) on 3-month 90-minute FDG-PET/CT. Median follow-up was 13.3 months. All measured SUV endpoints predicted recurrence. Change of SUV{sub max} slope after 90 minutes more accurately identified nonrecurrence in positive or equivocal sites than our current standard of SUV{sub max} ≥2.5 (P=.02). Conclusions: The positive predictive value of post-RT FDG-PET/CT may significantly improve using novel second derivative analysis of dynamic triphasic FDG-PET/CT SUV{sub max} slope, accurately distinguishing tumor from inflammation on positive and equivocal scans.« less

All-to-all sequenced fault detection system

DOEpatents

Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

2010-11-02

An apparatus, program product and method enable nodal fault detection by sequencing communications between all system nodes. A master node may coordinate communications between two slave nodes before sequencing to and initiating communications between a new pair of slave nodes. The communications may be analyzed to determine the nodal fault.

PATRAN-STAGS translator (PATSTAGS)

NASA Technical Reports Server (NTRS)

Otte, Neil

1990-01-01

A a computer program used to translate PATRAN finite element model data into Structural Analysis of General Shells (STAGS) input data is presented. The program supports translation of nodal, nodal constraints, element, force, and pressure data. The subroutine UPRESS required for the readings of live pressure data into STAGS is also presented.

Performance of a recoverable tug for planetary missions including use of perigee propulsion and corrections for nodal regression

NASA Technical Reports Server (NTRS)

Borsody, J.

1976-01-01

Mathematical equations are derived by using the Maximum Principle to obtain the maximum payload capability of a reusable tug for planetary missions. The mathematical formulation includes correction for nodal precession of the space shuttle orbit. The tug performs this nodal correction in returning to this precessed orbit. The sample case analyzed represents an inner planet mission as defined by the declination (fixed) and right ascension of the outgoing asymptote and the mission energy. Payload capability is derived for a typical cryogenic tug and the sample case with and without perigee propulsion. Optimal trajectory profiles and some important orbital elements are also discussed.

“Nodal Gap” induced by the incommensurate diagonal spin density modulation in underdoped high- T c superconductors

DOE PAGES

Zhou, Tao; Gao, Yi; Zhu, Jian -Xin

2015-03-07

Recenmore » tly it was revealed that the whole Fermi surface is fully gapped for several families of underdoped cuprates. The existence of the finite energy gap along the d -wave nodal lines (nodal gap) contrasts the common understanding of the d -wave pairing symmetry, which challenges the present theories for the high- T c superconductors. Here we propose that the incommensurate diagonal spin-density-wave order can account for the above experimental observation. The Fermi surface and the local density of states are also studied. Our results are in good agreement with many important experiments in high- T c superconductors.« less

Pathology of nodal marginal zone lymphomas.

PubMed

Pileri, Stefano; Ponzoni, Maurilio

Nodal marginal zone B cell lymphomas (NMZLs) are a rare group of lymphoid disorders part of the spectrum of marginal zone B-cell lymphomas, which encompass splenic marginal one B-cell lymphoma (SMZL) and extra nodal marginal zone of B-cell lymphoma (EMZL), often of MALT-type. Two clinicopathological forms of NMZL are recognized: adult-type and pediatric-type, respectively. NMZLs show overlapping features with other types of MZ, but distinctive features as well. In this review, we will focus on the salient distinguishing features of NMZL mostly under morphological/immunophenotypical/molecular perspectives in views of the recent acquisitions and forthcoming updated 2016 WHO classification of lymphoid malignancies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Involved-Field Radiotherapy versus Elective Nodal Irradiation in Combination with Concurrent Chemotherapy for Locally Advanced Non-Small Cell Lung Cancer: A Prospective Randomized Study

PubMed Central

Chen, Ming; Bao, Yong; Ma, Hong-Lian; Wang, Jin; Wang, Yan; Peng, Fang; Zhou, Qi-Chao; Xie, Cong-Hua

2013-01-01

This prospective randomized study is to evaluate the locoregional failure and its impact on survival by comparing involved field radiotherapy (IFRT) with elective nodal irradiation (ENI) in combination with concurrent chemotherapy for locally advanced non-small cell lung cancer. It appears that higher dose could be delivered in IFRT arm than that in ENI arm, and IFRT did not increase the risk of initially uninvolved or isolated nodal failures. Both a tendency of improved locoregional progression-free survival and a significant increased overall survival rate are in favor of IFRT arm in this study. PMID:23762840

Off-diagonal Jacobian support for Nodal BCs

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

Peterson, John W.; Andrs, David; Gaston, Derek R.

In this brief note, we describe the implementation of o-diagonal Jacobian computations for nodal boundary conditions in the Multiphysics Object Oriented Simulation Environment (MOOSE) [1] framework. There are presently a number of applications [2{5] based on the MOOSE framework that solve complicated physical systems of partial dierential equations whose boundary conditions are often highly nonlinear. Accurately computing the on- and o-diagonal Jacobian and preconditioner entries associated to these constraints is crucial for enabling ecient numerical solvers in these applications. Two key ingredients are required for properly specifying the Jacobian contributions of nonlinear nodal boundary conditions in MOOSE and nite elementmore » codes in general: 1. The ability to zero out entire Jacobian matrix rows after \

Symmorphic Intersecting Nodal Rings in Semiconducting Layers

NASA Astrophysics Data System (ADS)

Gong, Cheng; Xie, Yuee; Chen, Yuanping; Kim, Heung-Sik; Vanderbilt, David

2018-03-01

The unique properties of topological semimetals have strongly driven efforts to seek for new topological phases and related materials. Here, we identify a critical condition for the existence of intersecting nodal rings (INRs) in symmorphic crystals, and further classify all possible kinds of INRs which can be obtained in the layered semiconductors with Amm2 and Cmmm space group symmetries. Several honeycomb structures are suggested to be topological INR semimetals, including layered and "hidden" layered structures. Transitions between the three types of INRs, named as α , β , and γ type, can be driven by external strains in these structures. The resulting surface states and Landau-level structures, more complicated than those resulting from a simple nodal loop, are also discussed.

Experimental Influence Coefficients and Vibration Modes

NASA Technical Reports Server (NTRS)

Weidman, Deene J.; Kordes, Eldon E.

1959-01-01

Test results are presented for both symmetrical and antisymmetrical static loading of a wing model mounted on a three-point support system. The first six free-free vibration modes were determined experimentally. A comparison is made of the symmetrical nodal patterns and frequencies with the symmetrical nodal patterns and frequencies calculated from the experimental influence coefficients.

PATSTAGS: PATRAN-To-STAGSC-1 Translator

NASA Technical Reports Server (NTRS)

Otte, Neil

1993-01-01

PATSTAGS computer program translates data from PATRAN finite-element mathematical model into STAGS input records used for engineering analysis. Reads data from PATRAN neutral file and writes STAGS input records into STAGS input file and UPRESS data file. Supports translations of nodal constraints, and of nodal, element, force, and pressure data. Written in FORTRAN 77.

Macroscopy predicts tumor progression in gastric cancer: A retrospective patho-historical analysis based on Napoleon Bonaparte's autopsy report.

PubMed

Dawson, Heather; Novotny, Alexander; Becker, Karen; Reim, Daniel; Langer, Rupert; Gullo, Irene; Svrcek, Magali; Niess, Jan H; Tutuian, Radu; Truninger, Kaspar; Diamantis, Ioannis; Blank, Annika; Zlobec, Inti; Riddell, Robert H; Carneiro, Fatima; Fléjou, Jean-François; Genta, Robert M; Lugli, Alessandro

2016-11-01

The cause of Napoleon Bonaparte's death remains controversial. Originally suggested to be gastric cancer, whether this was truly neoplastic or a benign lesion has been recently debated. To interpret findings of original autopsy reports in light of the current knowledge of gastric cancer and to highlight the significance of accurate macroscopy in modern-day medicine. Using original autopsy documents, endoscopic images and data from current literature, Napoleon's gastric situation was reconstructed. In a multicenter collection of 2071 gastric cancer specimens, the relationship between tumor size and features of tumor progression was assessed. Greater tumor size was associated with advanced pT, nodal metastases and Borrmann types 3-4 (p<0.001). The best cut-off for predicting pT3-4 tumors was 6.5cm (AUC 0.8; OR 1.397, 95% CI 1.35-1.446), and 6cm for lymph node metastases (AUC 0.775; OR 1.389, 95% CI 1.338-1.442). The 6cm cut-off of had a positive predictive value of 0.820 for nodal metastases and a negative predictive value of 0.880 for distant metastases. This analysis combines Napoleon's autopsy with present-day knowledge to support gastric cancer as his terminal illness and emphasizes the role of macroscopy, which may provide valuable information on gastric cancer progression and aid patient management. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Prognostic Modeling in Pathologic N1 Breast Cancer Without Elective Nodal Irradiation After Current Standard Systemic Management.

PubMed

Yu, Jeong Il; Park, Won; Choi, Doo Ho; Huh, Seung Jae; Nam, Seok Jin; Kim, Seok Won; Lee, Jeong Eon; Kil, Won Ho; Im, Young-Hyuck; Ahn, Jin Seok; Park, Yeon Hee; Cho, Eun Yoon

2015-08-01

This study was conducted to establish a prognostic model in patients with pathologic N1 (pN1) breast cancer who have not undergone elective nodal irradiation (ENI) under the current standard management and to suggest possible indications for ENI. We performed a retrospective study with patients with pN1 breast cancer who received the standard local and preferred adjuvant chemotherapy treatment without neoadjuvant chemotherapy and ENI from January 2005 to June 2011. Most of the indicated patients received endocrine and trastuzumab therapy. In 735 enrolled patients, the median follow-up period was 58.4 months (range, 7.2-111.3 months). Overall, 55 recurrences (7.4%) developed, and locoregional recurrence was present in 27 patients (3.8%). Recurrence-free survival was significantly related to lymphovascular invasion (P = .04, hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.03-2.88), histologic grade (P = .03, HR, 2.57; 95% CI, 1.05-6.26), and nonluminal A subtype (P = .02, HR, 3.04; 95% CI, 1.23-7.49) in multivariate analysis. The prognostic model was established by these 3 prognostic factors. Recurrence-free survival was less than 90% at 5 years in cases with 2 or 3 factors. The prognostic model has stratified risk groups in pN1 breast cancer without ENI. Patients with 2 or more factors should be considered for ENI. Copyright © 2015 Elsevier Inc. All rights reserved.

Contribution of Hedgehog signaling to the establishment of left-right asymmetry in the sea urchin

PubMed Central

Warner, Jacob F.; Miranda, Esther L.; McClay, David R.

2016-01-01

Summary Most bilaterians exhibit a left-right asymmetric distribution of their internal organs. The sea urchin larva is notable in this regard since most adult structures are generated from left sided embryonic structures. The gene regulatory network governing this larval asymmetry is still a work in progress but involves several conserved signaling pathways including Nodal, and BMP. Here we provide a comprehensive analysis of Hedgehog signaling and it’s contribution to left-right asymmetry. We report that Hh signaling plays a conserved role to regulate late asymmetric expression of Nodal and that this regulation occurs after Nodal breaks left-right symmetry in the mesoderm. Thus, while Hh functions to maintain late Nodal expression, the molecular asymmetry of the future coelomic pouches is locked in. Furthermore we report that cilia play a role only insofar as to transduce Hh signaling and do not have an independent effect on the asymmetry of the mesoderm. From this, we are able to construct a more complete regulatory network governing the establishment of left-right asymmetry in the sea urchin. PMID:26872875

Contribution of hedgehog signaling to the establishment of left-right asymmetry in the sea urchin.

PubMed

Warner, Jacob F; Miranda, Esther L; McClay, David R

2016-03-15

Most bilaterians exhibit a left-right asymmetric distribution of their internal organs. The sea urchin larva is notable in this regard since most adult structures are generated from left sided embryonic structures. The gene regulatory network governing this larval asymmetry is still a work in progress but involves several conserved signaling pathways including Nodal, and BMP. Here we provide a comprehensive analysis of Hedgehog signaling and it's contribution to left-right asymmetry. We report that Hh signaling plays a conserved role to regulate late asymmetric expression of Nodal and that this regulation occurs after Nodal breaks left-right symmetry in the mesoderm. Thus, while Hh functions to maintain late Nodal expression, the molecular asymmetry of the future coelomic pouches is locked in. Furthermore we report that cilia play a role only insofar as to transduce Hh signaling and do not have an independent effect on the asymmetry of the mesoderm. From this, we are able to construct a more complete regulatory network governing the establishment of left-right asymmetry in the sea urchin. Copyright © 2016 Elsevier Inc. All rights reserved.

An efficient in vitro regeneration protocol for a natural dye yielding plant, Strobilanthes flaccidifolious Nees., from nodal explants.

PubMed

Deb, Chitta Ranjan; Arenmongla, T

2012-11-01

Adventitious shoot buds formation from axillary buds of nodal segments of S. flaccidifolious was achieved on MS medium containing sucrose (3%, w/v), and a-naphthalene acetic acid (NAA; 3 microM) and benzyl adenine (3 microM) in combination. The nodal segments were primed on 'Growtak Sieve' for 48 h on MS medium containing sucrose (2%), polyvinyl pyrollidone (200 mgL(-1)) as antioxidant. About 80% of primed nodal segments responded positively and formed approximately 12 adventitious shoot buds per explants from explants collected during October-November months of every year. The shoot buds converted into plantlets on MS medium containing sucrose (3%) and kinetin (3 microM) where approximately 7 micro shoots developed per subculture after 8 weeks of culture. The regenerated micro shoots induced average 14 roots/plant on medium containing NAA (3 microM). The regenerates were hardened for 6-7 weeks on medium with 1/2MS salt solution and sucrose (2%) under normal laboratory condition before transferring to potting mix. About 70% transplants survived after two months of transfer.

Nodal to nodeless superconducting energy-gap structure change concomitant with Fermi-surface reconstruction in the heavy-fermion compound CeCoIn 5

DOE PAGES

Kim, Hyunsoo; Tanatar, M. A.; Flint, R.; ...

2015-01-15

The London penetration depth, λ(T), was measured in single crystals of Ce 1-xR xCoIn 5, R=La, Nd and Yb down to T min ≈ 50 mK (T c/T min ~50) using a tunnel-diode resonator. In the cleanest samples Δλ(T) is best described by the power law, Δλ(T) ∝ T n, with n ~ 1, consistent with line nodes. Substitutions of Ce with La, Nd and Yb lead to similar monotonic suppressions of T c, however the effects on Δλ(T) differ. While La and Nd dopings lead to increase of the exponent n and saturation at n ~ 2, as expectedmore » for a dirty nodal superconductor, Yb doping leads to n > 3, suggesting a change from nodal to nodeless superconductivity. As a result, this superconducting gap structure change happen in the same doping range where changes of the Fermi surface topology were reported, implying that the nodal structure and Fermi surface topology are closely linked.« less

Serum decoy receptor 3 level: a predictive marker for nodal metastasis and survival among oral cavity cancer patients.

PubMed

Tu, Hsi-Feng; Liu, Chung-Ji; Liu, Shyun-Yeu; Chen, Yu-Ping; Yu, En-Hao; Lin, Shu-Chun; Chang, Kuo-Wei

2011-03-01

Validating markers for prediction of nodal metastasis could be beneficial in treatment of oral cavity cancer. Decoy receptor 3 (DcR3), locus on 20q13, functions as a death decoy inhibiting apoptosis mediated by the tumor necrosis factor receptor (TNFR) family. This study analyzed the serum level of DcR3 in relationship to the clinical parameters of oral cavity cancer patients together with detection of DcR3 genomic copy number in primary and recurrent tumors. Elevated serum DcR3 was associated with nodal metastasis and worse prognosis. Gain of DcR3 copy number was detected in 17% of primary tumor tissue but not found in healthy areca chewers. Tissue from recurrent tumors showed more frequent DcR3 copy number alteration (48%) than the paired primary tumor tissue. Serum DcR3 level is a predictor for the nodal metastasis and survival among oral cavity cancer patients and the DcR3 copy number alteration could underlie oral carcinogenesis progression. Copyright © 2010 Wiley Periodicals, Inc.

Robustness Elasticity in Complex Networks

PubMed Central

Matisziw, Timothy C.; Grubesic, Tony H.; Guo, Junyu

2012-01-01

Network robustness refers to a network’s resilience to stress or damage. Given that most networks are inherently dynamic, with changing topology, loads, and operational states, their robustness is also likely subject to change. However, in most analyses of network structure, it is assumed that interaction among nodes has no effect on robustness. To investigate the hypothesis that network robustness is not sensitive or elastic to the level of interaction (or flow) among network nodes, this paper explores the impacts of network disruption, namely arc deletion, over a temporal sequence of observed nodal interactions for a large Internet backbone system. In particular, a mathematical programming approach is used to identify exact bounds on robustness to arc deletion for each epoch of nodal interaction. Elasticity of the identified bounds relative to the magnitude of arc deletion is assessed. Results indicate that system robustness can be highly elastic to spatial and temporal variations in nodal interactions within complex systems. Further, the presence of this elasticity provides evidence that a failure to account for nodal interaction can confound characterizations of complex networked systems. PMID:22808060

MailMinder: taming DHCP's mailman interface.

PubMed

Shultz, E K; Brown, R; Kotta, G

1992-01-01

While the Department of Veteran's Affairs Decentralized Hospital Computer Program (DHCP) is one of the most widely disseminated and successful hospital information systems in existence, it currently is accessed through a user interface which is not as mature as the rest of the system. This interface is a VT-100 compatible, character oriented interface using menus accessed by typed commands for feature access. This project demonstrated that a mature graphical user interface (MailMinder) can be successfully used as a "front-end" to DHCP. MailMinder is completely compatible with the existing unmodified DHCP electronic mail program, Mailman. MailMinder allows the user to be more efficient than the current interface and offers additional features over the current mail system. The program has undergone evaluation and limited deployment at five separate sites. The feature set of this program and its operation will be shown at this demonstration. The demonstration has implications for all current hospital information systems.

MailMinder: taming DHCP's mailman interface.

PubMed Central

Shultz, E. K.; Brown, R.; Kotta, G.

1992-01-01

While the Department of Veteran's Affairs Decentralized Hospital Computer Program (DHCP) is one of the most widely disseminated and successful hospital information systems in existence, it currently is accessed through a user interface which is not as mature as the rest of the system. This interface is a VT-100 compatible, character oriented interface using menus accessed by typed commands for feature access. This project demonstrated that a mature graphical user interface (MailMinder) can be successfully used as a "front-end" to DHCP. MailMinder is completely compatible with the existing unmodified DHCP electronic mail program, Mailman. MailMinder allows the user to be more efficient than the current interface and offers additional features over the current mail system. The program has undergone evaluation and limited deployment at five separate sites. The feature set of this program and its operation will be shown at this demonstration. The demonstration has implications for all current hospital information systems. PMID:1482995

From cluster structures to nuclear molecules: The role of nodal structure of the single-particle wave functions

NASA Astrophysics Data System (ADS)

Afanasjev, A. V.; Abusara, H.

2018-02-01

The nodal structure of the density distributions of the single-particle states occupied in rod-shaped, hyper- and megadeformed structures of nonrotating and rotating N ˜Z nuclei has been investigated in detail. The single-particle states with the Nilsson quantum numbers of the [N N 0 ]1 /2 (with N from 0 to 5) and [N ,N -1 ,1 ]Ω (with N from 1 to 3 and Ω =1 /2 , 3/2) types are considered. These states are building blocks of extremely deformed shapes in the nuclei with mass numbers A ≤50 . Because of (near) axial symmetry and large elongation of such structures, the wave functions of the single-particle states occupied are dominated by a single basis state in cylindrical basis. This basis state defines the nodal structure of the single-particle density distribution. The nodal structure of the single-particle density distributions allows us to understand in a relatively simple way the necessary conditions for α clusterization and the suppression of the α clusterization with the increase of mass number. It also explains in a natural way the coexistence of ellipsoidal mean-field-type structures and nuclear molecules at similar excitation energies and the features of particle-hole excitations connecting these two types of the structures. Our analysis of the nodal structure of the single-particle density distributions does not support the existence of quantum liquid phase for the deformations and nuclei under study.

A point-value enhanced finite volume method based on approximate delta functions

NASA Astrophysics Data System (ADS)

Xuan, Li-Jun; Majdalani, Joseph

2018-02-01

We revisit the concept of an approximate delta function (ADF), introduced by Huynh (2011) [1], in the form of a finite-order polynomial that holds identical integral properties to the Dirac delta function when used in conjunction with a finite-order polynomial integrand over a finite domain. We show that the use of generic ADF polynomials can be effective at recovering and generalizing several high-order methods, including Taylor-based and nodal-based Discontinuous Galerkin methods, as well as the Correction Procedure via Reconstruction. Based on the ADF concept, we then proceed to formulate a Point-value enhanced Finite Volume (PFV) method, which stores and updates the cell-averaged values inside each element as well as the unknown quantities and, if needed, their derivatives on nodal points. The sharing of nodal information with surrounding elements saves the number of degrees of freedom compared to other compact methods at the same order. To ensure conservation, cell-averaged values are updated using an identical approach to that adopted in the finite volume method. Here, the updating of nodal values and their derivatives is achieved through an ADF concept that leverages all of the elements within the domain of integration that share the same nodal point. The resulting scheme is shown to be very stable at successively increasing orders. Both accuracy and stability of the PFV method are verified using a Fourier analysis and through applications to the linear wave and nonlinear Burgers' equations in one-dimensional space.

Management of recurrent/persistent nodal disease in patients with differentiated thyroid cancer: a critical review of the risks and benefits of surgical intervention versus active surveillance.

PubMed

Tufano, Ralph P; Clayman, Gary; Heller, Keith S; Inabnet, William B; Kebebew, Electron; Shaha, Ashok; Steward, David L; Tuttle, R Michael

2015-01-01

The primary goals of this interdisciplinary consensus statement are to define the eligibility criteria for management of recurrent and persistent cervical nodal disease in patients with differentiated thyroid cancer (DTC) and to review the risks and benefits of surgical intervention versus active surveillance. A writing group was convened by the Surgical Affairs Committee of the American Thyroid Association and was tasked with identifying the important clinical elements to consider when managing recurrent/persistent nodal disease in patients with DTC based on the available evidence in the literature and the group's collective experience. The decision on how best to manage individual patients with suspected recurrent/persistent nodal disease is challenging and requires the consideration of a significant number of variables outlined by the members of the interdisciplinary team. Here we report on the consensus opinions that were reached by the writing group regarding the technical and clinical issues encountered in this patient population. Identification of recurrent/persistent disease requires a team decision-making process that includes the patient and physicians as to what, if any, intervention should be performed to best control the disease while minimizing morbidity. Several management principles and variables involved in the decision making for surgery versus active surveillance were developed that should be taken into account when deciding how best to manage a patient with DTC and suspected recurrent or persistent cervical nodal disease.

Rapid enhancement of nodal quasiparticle mass with heavily underdoping in Bi2212

NASA Astrophysics Data System (ADS)

Anzai, Hiroaki; Arita, Masashi; Namatame, Hirofumi; Taniguchi, Masaki; Ishikado, Motoyuki; Fujita, Kazuhiro; Ishida, Shigeyuki; Uchida, Shin-ichi; Ino, Akihiro

2018-05-01

We report substantial advance of our low-energy angle-resolved photoemission study of nodal quasiparticles in Bi2Sr2CaCu2O8+δ. The new data cover the samples from underdoped down to heavily underdoped levels. We also present the nodal Fermi velocities that determined by using an excitation-photon energy of hν = 7.0 eV over a wide doping range. The consistency between the results with hν = 8.1 and 7.0 eV allows us to rule out the effect of photoemission matrix elements. In comparison with the data previously reported, the nodal effective mass increases by a factor of ∼ 1.5 in going from optimally doped to heavily underdoped levels. We find a rapid enhancement of the nodal quasiparticle mass at low doping levels near the superconductor-to-insulator transition. The effective coupling spectrum, λ (ω) , is extracted directly from the energy derivatives of the quasiparticle dispersion and scattering rate, as a causal function of the mass enhancement factor. A steplike increase in Reλ (ω) around ∼ 65 meV is demonstrated clearly by the Kramers-Kronig transform of Imλ (ω) . To extract the low-energy renormalization effect, we calculated a simple model for the electron-boson interaction. This model reveals that the contribution of the renormalization at | ω | ≤ 15 meV to the quasiparticle mass is larger than that around 65 meV in underdoped samples.

Recovering tubewise power from three-dimensional nodal kinetics calculation during material relocation in an HWR

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

Kalimullah; Morris, E.E.; Yang, W.S.

1994-12-31

To analyze severe accidents in some special-purpose heavy-water reactors made of assemblies consisting of a number of coaxial tubes of aluminum-clad U-Al fuel and aluminum-clad neutron-capturing material, a mechanistic model, MARTINS, for tube beatup, melting, and molten material relocation has been developed and integrated with the DIF3D nodal hexagonal-z reactor kinetics and other phenomenological modules. The DIF3D kinetics homogenizes all materials located and computes the total power produced in an axial segment of a fuel assembly. This paper presents an approximate method, used in MARTINS, to calculate the distribution of this total nodal power into the intact fuel and capturingmore » material tubes and the meat-cladding mixtures relocating during tube disruption. The method accounts for the change in intraassembly radial power profile due to assembly geometry change with the progress of segment-by-segment disruption of different tubes. Earlier methods to recover pinwise power from nodal calculation for liquid-metal-cooled reactors and light water reactors (X-Y and hexagonal unit cells) are not practical for a disrupting assembly having material relocation. Figure 1 shows the assembly`s end view, divided into rings for modeling and analysis. A ring is a coolant subchannel plus the outer surrounding tube. The present method for distributing the nodal power consists of two parts: (a) calculation of the relative values of ring-by-ring power per unit uranium mass and power per unit mass of neutron-capturing material in a given assembly segment, and (b) normalization of these relative values such that the total power of all rings (intact tubes and U-Al-Cp meat-cladding mixtures, where Cp implies the neutron-capturing material) equals the DIF3D-calculated nodal power for the assembly axial segment.« less

Regional brain network organization distinguishes the combined and inattentive subtypes of Attention Deficit Hyperactivity Disorder.

PubMed

Saad, Jacqueline F; Griffiths, Kristi R; Kohn, Michael R; Clarke, Simon; Williams, Leanne M; Korgaonkar, Mayuresh S

2017-01-01

Attention Deficit Hyperactivity Disorder (ADHD) is characterized clinically by hyperactive/impulsive and/or inattentive symptoms which determine diagnostic subtypes as Predominantly Hyperactive-Impulsive (ADHD-HI), Predominantly Inattentive (ADHD-I), and Combined (ADHD-C). Neuroanatomically though we do not yet know if these clinical subtypes reflect distinct aberrations in underlying brain organization. We imaged 34 ADHD participants defined using DSM-IV criteria as ADHD-I ( n  = 16) or as ADHD-C ( n  = 18) and 28 matched typically developing controls, aged 8-17 years, using high-resolution T1 MRI. To quantify neuroanatomical organization we used graph theoretical analysis to assess properties of structural covariance between ADHD subtypes and controls (global network measures: path length, clustering coefficient, and regional network measures: nodal degree). As a context for interpreting network organization differences, we also quantified gray matter volume using voxel-based morphometry. Each ADHD subtype was distinguished by a different organizational profile of the degree to which specific regions were anatomically connected with other regions (i.e., in "nodal degree"). For ADHD-I (compared to both ADHD-C and controls) the nodal degree was higher in the hippocampus. ADHD-I also had a higher nodal degree in the supramarginal gyrus, calcarine sulcus, and superior occipital cortex compared to ADHD-C and in the amygdala compared to controls. By contrast, the nodal degree was higher in the cerebellum for ADHD-C compared to ADHD-I and in the anterior cingulate, middle frontal gyrus and putamen compared to controls. ADHD-C also had reduced nodal degree in the rolandic operculum and middle temporal pole compared to controls. These regional profiles were observed in the context of no differences in gray matter volume or global network organization. Our results suggest that the clinical distinction between the Inattentive and Combined subtypes of ADHD may also be reflected in distinct aberrations in underlying brain organization.

Spin Current Noise of the Spin Seebeck Effect and Spin Pumping

NASA Astrophysics Data System (ADS)

Matsuo, M.; Ohnuma, Y.; Kato, T.; Maekawa, S.

2018-01-01

We theoretically investigate the fluctuation of a pure spin current induced by the spin Seebeck effect and spin pumping in a normal-metal-(NM-)ferromagnet(FM) bilayer system. Starting with a simple ferromagnet-insulator-(FI-)NM interface model with both spin-conserving and non-spin-conserving processes, we derive general expressions of the spin current and the spin-current noise at the interface within second-order perturbation of the FI-NM coupling strength, and estimate them for a yttrium-iron-garnet-platinum interface. We show that the spin-current noise can be used to determine the effective spin carried by a magnon modified by the non-spin-conserving process at the interface. In addition, we show that it provides information on the effective spin of a magnon, heating at the interface under spin pumping, and spin Hall angle of the NM.

Modification of atrioventricular nodal electrophysiology by selective radiofrequency delivery on the anterior or posterior approaches.

PubMed

Chorro, F J; Sanchis, J; Such, L; Artal, L; Llavador, J J; Llavador, E; Monmeneu, J V; López-Merino, V

1997-05-01

An analysis was made in 14 isolated and perfused rabbit hearts of the electrophysiological effects of selective radiofrequency (RF) delivery in the anterior (group I, n = 7) or posterior zone (group II, n = 7) of the Koch triangle, with the aim of modifying atrioventricular nodal (AVN) conduction without suppressing 1:1 transmission. After opening the right atrium, RF was delivered (0.5 W) with a 1-mm diameter unipolar electrode positioned in the selected zone until a prolongation of no less than 15% was obtained in the Wenckebach cycle length (WCL). Before and after (30 min) RF, anterograde and retrograde AVN refractoriness and conduction were evaluated, stimulating from the crista terminalis (CT), the interatrial septum (IAS), and from the RV epicardium. After RF, the following percentage increments were observed in group I: AH(CT) = 36% +/- 9%, AH(IAS) = 38% +/- 11%, WCL(CT) = 28% +/- 8%, WCL(IAS) = 22% +/- 6%, functional refractory period (FRP) of the AVN(CT) = 13% +/- 11%, FRP-AVN(IAS) = 13% +/- 8%, retrograde WCL = 20% +/- 19%, and retrograde FRPVA = 13% +/- 16%. The increments observed in group II and the significances of the differences with respect to group I were: AH(CT) = 11% +/- 14% (P < 0.01), AH(IAS) = 19% +/- 32% (NS), WCL(CT) = 42% +/- 14% (P < 0.05), WCL(IAS) = 42% +/- 16% (P < 0.01), FRP-AVN(CT) = 28% +/- 28% (NS), FRP-AVN(LAS) = 21% +/- 19% (NS), retrograde WCL = 35% +/- 24% (NS), and retrograde FRP = 16% +/- 13% (NS). In both groups, the AH interval variations were not correlated with those of the rest of the parameters analyzed. Truncated nodal function curves suggestive of a dual AV nodal pathway were obtained in three experiments, though in only one of them was this observed under basal conditions. In the other two experiments, with dual AV nodal physiology only after RF (one from each group), AV nodal reentrant tachycardias were triggered with atrial extrastimulus at coupling intervals equal to or shorter than at those that cause a sudden lengthening of the AH interval, RF delivered in the anterior and posterior zones of the Koch triangle produced effects of different magnitude on the AH interval and Wenckebach cycle length. In the anterior zone the AH interval was prolonged to a greater extent, while in the posterior zone the effects were greater on the Wenckebach cycle length. No correlation existed between the variations in AH interval and Wenckebach cycle length, regardless of where RF was delivered. The evaluation of anterograde AV nodal refractoriness was similar when stimulating from the crista terminalis or from the interatrial septum. By delivering RF, it was possible to induce dual AV nodal physiology and reentrant tachycardias.

Interface-driven spin-torque ferromagnetic resonance by Rashba coupling at the interface between nonmagnetic materials

DOE PAGES

Jungfleisch, M. B.; Zhang, W.; Sklenar, J.; ...

2016-06-20

The Rashba-Edelstein effect stems from the interaction between the electron's spin and its momentum induced by spin-orbit interaction at an interface or a surface. It was shown that the inverse Rashba-Edelstein effect can be used to convert a spin current into a charge current. Here, we demonstrate the reverse process of a charge-to spin-current conversion at a Bi/Ag Rashba interface. We show that this interface-driven spin current can drive an adjacent ferromagnet to resonance. We employ a spin-torque ferromagnetic resonance excitation/detection scheme which was developed originally for a bulk spin-orbital effect, the spin Hall effect. In our experiment, the directmore » Rashba-Edelstein effect generates an oscillating spin current from an alternating charge current driving the magnetization precession in a neighboring permalloy (Py, Ni 80Fe 20) layer. As a result, electrical detection of the magnetization dynamics is achieved by a rectificationmechanism of the time dependent multilayer resistance arising from the anisotropic magnetoresistance.« less

Oncological outcomes from trimodality therapy receiving definitive doses of neoadjuvant chemoradiation (≥60 Gy) and factors influencing consideration for surgery in stage III non-small cell lung cancer.

PubMed

Vyfhuis, Melissa A L; Bhooshan, Neha; Burrows, Whitney M; Turner, Michelle; Suntharalingam, Mohan; Donahue, James; Nichols, Elizabeth M; Feliciano, Josephine; Bentzen, Søren M; Badiyan, Shahed; Carr, Shamus R; Friedberg, Joseph; Simone, Charles B; Edelman, Martin J; Feigenberg, Steven J; Mohindra, Pranshu

2017-01-01

Guidelines for locally advanced non-small cell lung cancer (LA-NSCLC) recommend definitive chemoradiation therapy (CRT) for cN2-N3 disease, reserving surgery for patients with minimal nodal involvement at presentation. The current literature suggests that surgery after CRT for stage III NSCLC can improve freedom-from-recurrence (FFR) but has not consistently demonstrated an improvement in overall survival, perhaps partly due to the low (45-50.4 Gy) preoperative doses delivered that result in low rates of mediastinal nodal clearance. We therefore analyzed factors associated with trimodality therapy receipt and determined outcomes in patients with LA-NSCLC who were treated with definitive doses (≥60 Gy) of neoadjuvant CRT prior to surgery. We retrospectively analyzed 355 consecutive patients with LA-NSCLC who were treated with curative intent between January 2000 and December 2013. The Kaplan-Meier method was used to estimate the overall survival and FFR of patients who were initially planned to receive trimodality treatment but never underwent surgery (unplanned bimodality) compared with those who were never considered to be surgical candidates (planned bimodality) and those who underwent surgical resection after CRT (trimodality). Cox proportional hazards regression with forward selection was used for multivariate analyses, and the Fisher exact test was used to test contingency tables. Patients who received trimodality therapy had a longer median survival than those with unplanned or planned bimodality therapy at 59.9, 20.1, and 17.3 months, respectively ( P < .001). The survival benefit with surgery persisted in patients with stage IIIB ( P < .001) and N3 ( P = .010) nodal disease when mediastinal nodal clearance was achieved. FFR was also improved with surgical resection ( P = .001). Race ( P < .001), stage ( P < .001), performance status ( P < .001), age ( P < .001), and diagnosis of chronic obstructive pulmonary disease ( P = .009) were significant indicators that influenced both the decision to initially choose trimodality therapy at consultation and to actually perform surgical resection. Trimodality treatment significantly improves survival and FFR in patients with LA-NSCLC when definitive doses of radiation with neoadjuvant chemotherapy are employed. We identified important demographic features that predict the use of surgical intervention in patients with stage III NSCLC.

Simultaneous Quantification of Spatially Discordant Alternans in Voltage and Intracellular Calcium in Langendorff-Perfused Rabbit Hearts and Inconsistencies with Models of Cardiac Action Potentials and Ca Transients

PubMed Central

Uzelac, Ilija; Ji, Yanyan C.; Hornung, Daniel; Schröder-Scheteling, Johannes; Luther, Stefan; Gray, Richard A.; Cherry, Elizabeth M.; Fenton, Flavio H.

2017-01-01

Rationale: Discordant alternans, a phenomenon in which the action potential duration (APDs) and/or intracellular calcium transient durations (CaDs) in different spatial regions of cardiac tissue are out of phase, present a dynamical instability for complex spatial dispersion that can be associated with long-QT syndrome (LQTS) and the initiation of reentrant arrhythmias. Because the use of numerical simulations to investigate arrhythmic effects, such as acquired LQTS by drugs is beginning to be studied by the FDA, it is crucial to validate mathematical models that may be used during this process. Objective: In this study, we characterized with high spatio-temporal resolution the development of discordant alternans patterns in transmembrane voltage (Vm) and intracellular calcium concentration ([Cai]+2) as a function of pacing period in rabbit hearts. Then we compared the dynamics to that of the latest state-of-the-art model for ventricular action potentials and calcium transients to better understand the underlying mechanisms of discordant alternans and compared the experimental data to the mathematical models representing Vm and [Cai]+2 dynamics. Methods and Results: We performed simultaneous dual optical mapping imaging of Vm and [Cai]+2 in Langendorff-perfused rabbit hearts with higher spatial resolutions compared with previous studies. The rabbit hearts developed discordant alternans through decreased pacing period protocols and we quantified the presence of multiple nodal points along the direction of wave propagation, both in APD and CaD, and compared these findings with results from theoretical models. In experiments, the nodal lines of CaD alternans have a steeper slope than those of APD alternans, but not as steep as predicted by numerical simulations in rabbit models. We further quantified several additional discrepancies between models and experiments. Conclusions: Alternans in CaD have nodal lines that are about an order of magnitude steeper compared to those of APD alternans. Current action potential models lack the necessary coupling between voltage and calcium compared to experiments and fail to reproduce some key dynamics such as, voltage amplitude alternans, smooth development of calcium alternans in time, conduction velocity and the steepness of the nodal lines of APD and CaD. PMID:29104543

Modeling Delamination in Postbuckled Composite Structures Under Static and Fatigue Loads

NASA Technical Reports Server (NTRS)

Bisagni, Chiara; Brambilla, Pietro; Bavila, Carlos G.

2013-01-01

The ability of the Abaqus progressive Virtual Crack Closure Technique (VCCT) to model delamination in composite structures was investigated for static, postbuckling, and fatigue loads. Preliminary evaluations were performed using simple Double Cantilever Beam (DCB) and Mixed-Mode Bending (MMB) specimens. The nodal release sequences that describe the propagation of the delamination front were investigated. The effect of using a sudden or a gradual nodal release was evaluated by considering meshes aligned with the crack front as well as misaligned meshes. Fatigue simulations were then performed using the Direct Cyclic Fatigue (DCF) algorithm. It was found that in specimens such as the DCB, which are characterized by a nearly linear response and a pure fracture mode, the algorithm correctly predicts the Paris Law rate of propagation. However, the Abaqus DCF algorithm does not consider different fatigue propagation laws in different fracture modes. Finally, skin/stiffener debonding was studied in an aircraft fuselage subcomponent in which debonding occurs deep into post-buckling deformation. VCCT was shown to be a robust tool for estimating the onset propagation. However, difficulties were found with the ability of the current implementation of the Abaqus progressive VCCT to predict delamination propagation within structures subjected to postbuckling deformations or fatigue loads.

Enhancement of neuronal differentiation by using small molecules modulating Nodal/Smad, Wnt/β-catenin, and FGF signaling.

PubMed

Song, Yonghee; Lee, Somyung; Jho, Eek-Hoon

2018-06-08

Pluripotent embryonic stem cells are one of the best modalities for the disease treatment due to their potential for self-renewal and differentiation into various cell types. Induction of stem cell differentiation into specific cell lineages has been investigated for decades, especially in vitro neuronal differentiation of embryonic stem cells. However, in vitro differentiation methods do not yield sufficient amounts of neurons for use in the therapeutic treatment of neurological disorders. Here, we provide an improved neuronal differentiation method based on a combination of small regulatory molecules for specific signaling pathways (FGF4 for FGF signaling, SB431542 for Nodal/Smad signaling, and XAV939 and BIO for Wnt signaling) in N2B27 media. We found that FGF4 was required for neural induction, SB431542 accelerated neural precursor differentiation, and treatment with XAV939 and BIO at different periods enhanced neuronal differentiation. These optimized neuronal differentiation conditions may allow a greater neuron cell yield within a shorter time than current methods and be the basis for treatment of neurological dysfunction using stem cells. Copyright © 2018. Published by Elsevier Inc.

Encouraging experience in the treatment of nasal type extra-nodal NK/T-cell lymphoma in a non-Asian population.

PubMed

Qi, Shunan; Yahalom, Joachim; Hsu, Meier; Chelius, Monica; Lunning, Matthew; Moskowitz, Alison; Horwitz, Steven

2016-11-01

Extra-nodal NK/T-cell lymphoma, nasal type (EN-NK/TCL-NT), is rare in the Western world. We launched the current single-institutional retrospective study with Institutional Review Board approval to better understand the disease. 43 EN-NK/TCL-NT patients treated from 1996 to 2014 were analyzed, including 10 (23%) Asians and 33 (76%) non-Asians. 19/26 (73%) early-stage patients received short-course chemotherapy followed by radiotherapy. 14/17 (82%) advanced-stage patients received primary chemotherapy. Complete response rate was significantly higher in the modified-SMILE group than the accelerated-CHOP group (80% vs. 30%, p = 0.015). The 2-year overall survival (OS) and progression-free survival (PFS) were 60% and 40%, respectively. Early-stage disease had significantly higher 2-year OS (87% vs. 21%) and PFS (56% vs.18%) than advanced-stage (p < 0.001). Ethnicity had no prognostic difference. EN-NK/TCL-NT in non-Asians shared similar disease characteristics and treatment outcomes with Asians. Most early-stage patients have achieved durable remissions. Management of advanced-stage disease remains challenging, with frequent progression and high mortality.

Benign vascular proliferation in a lymph node following acute toxoplasmosis. A differential diagnosis from Kaposi's sarcoma.

PubMed

Rousselet, M C; Saint-André, J P; Beaufils, J M; Diebold, J

1988-12-01

We describe an unusual intranodal vascular proliferation following acute toxoplasmosis in a man. This proliferation is distinct from other benign vasoformative nodal lesions. It could be interpreted as a reactive healing process that might be misdiagnosed as nodal Kaposi's sarcoma. Some criteria to avoid such misdiagnosis are presented.

Anomalous contagion and renormalization in networks with nodal mobility

NASA Astrophysics Data System (ADS)

Manrique, Pedro D.; Qi, Hong; Zheng, Minzhang; Xu, Chen; Hui, Pak Ming; Johnson, Neil F.

2016-07-01

A common occurrence in everyday human activity is where people join, leave and possibly rejoin clusters of other individuals —whether this be online (e.g. social media communities) or in real space (e.g. popular meeting places such as cafes). In the steady state, the resulting interaction network would appear static over time if the identities of the nodes are ignored. Here we show that even in this static steady-state limit, a non-zero nodal mobility leads to a diverse set of outbreak profiles that is dramatically different from known forms, and yet matches well with recent real-world social outbreaks. We show how this complication of nodal mobility can be renormalized away for a particular class of networks.

Selective elimination of breast cancer surgery in exceptional responders: historical perspective and current trials.

PubMed

van la Parra, Raquel F D; Kuerer, Henry M

2016-03-08

With improvements in chemotherapy regimens, targeted therapies, and our fundamental understanding of the relationship of tumor subtype and pathologic complete response (pCR), there has been dramatic improvement in pCR rates in the past decade, especially among triple-negative and human epidermal growth factor receptor 2-positive breast cancers. Rates of pCR in these groups of patients can be in the 60 % range and thus question the paradigm for the necessity of breast and nodal surgery in all cases, particularly when the patient will be receiving adjuvant local therapy with radiotherapy. Current practice for patients who respond well to neoadjuvant chemotherapy (NCT) is often to proceed with the same breast and axillary procedures as would have been offered women who had not received NCT, regardless of the apparent clinical response. Given these high response rates in defined subgroups among exceptional responders it is appropriate to question whether surgery is now a redundant procedure in their overall management. Further, definitive radiation without surgical resection with or without systemic therapy has been proven effective for several other malignant disease sites including some stages of esophageal, anal, laryngeal, prostate, cervical, and lung carcinoma. The main impediments for potential elimination of surgery have been the fact that prior and current standard and functional breast imaging methods are incapable of accurate prediction of residual disease and that integrating percutaneous biopsy of the breast primary and nodes following NCT may circumvent this issue. This article highlights historical attempts at omission of surgery following NCT in an earlier era, the current status of breast and nodal imaging to predict residual carcinoma, and ongoing and planned trials designed to identify appropriate patients who might be selected for clinical trials designed to test the safety of selected elimination of breast cancer surgery in percutaneous image-guided biopsy-proven exceptional responders to NCT.

Utilizing van der Waals Slippery Interfaces to Enhance the Electrochemical Stability of Silicon Film Anodes in Lithium-Ion Batteries.

PubMed

Basu, Swastik; Suresh, Shravan; Ghatak, Kamalika; Bartolucci, Stephen F; Gupta, Tushar; Hundekar, Prateek; Kumar, Rajesh; Lu, Toh-Ming; Datta, Dibakar; Shi, Yunfeng; Koratkar, Nikhil

2018-04-25

High specific capacity anode materials such as silicon (Si) are increasingly being explored for next-generation, high performance lithium (Li)-ion batteries. In this context, Si films are advantageous compared to Si nanoparticle based anodes since in films the free volume between nanoparticles is eliminated, resulting in very high volumetric energy density. However, Si undergoes volume expansion (contraction) under lithiation (delithiation) of up to 300%. This large volume expansion leads to stress build-up at the interface between the Si film and the current collector, leading to delamination of Si from the surface of the current collector. To prevent this, adhesion promotors (such as chromium interlayers) are often used to strengthen the interface between the Si and the current collector. Here, we show that such approaches are in fact counter-productive and that far better electrochemical stability can be obtained by engineering a van der Waals "slippery" interface between the Si film and the current collector. This can be accomplished by simply coating the current collector surface with graphene sheets. For such an interface, the Si film slips with respect to the current collector under lithiation/delithiation, while retaining electrical contact with the current collector. Molecular dynamics simulations indicate (i) less stress build-up and (ii) less stress "cycling" on a van der Waals slippery substrate as opposed to a fixed interface. Electrochemical testing confirms more stable performance and much higher Coulombic efficiency for Si films deposited on graphene-coated nickel (i.e., slippery interface) as compared to conventional nickel current collectors.

A generic interface element for COMET-AR

NASA Technical Reports Server (NTRS)

Mccleary, Susan L.; Aminpour, Mohammad A.

1995-01-01

The implementation of an interface element capability within the COMET-AR software system is described. The report is intended for use by both users of currently implemented interface elements and developers of new interface element formulations. Guidance on the use of COMET-AR is given. A glossary is provided as an Appendix to this report for readers unfamiliar with the jargon of COMET-AR. A summary of the currently implemented interface element formulation is presented in Section 7.3 of this report.

Prognostic Value of National Comprehensive Cancer Network Lung Cancer Resection Quality Parameters

PubMed Central

Osarogiagbon, Raymond U.; Ray, Meredith A.; Faris, Nicholas R.; Div, M.; Smeltzer, Matthew P.; Stat, M.; Fehnel, Carrie; Houston-Harris, Cheryl; Signore, Raymond S.; McHugh, Laura M.; Levy, Paul; Wiggins, Lynn; Sachdev, Vishal; Robbins, Edward T.

2017-01-01

Background The National Comprehensive Cancer Network (NCCN) surgical resection guidelines for non-small-cell lung cancer (NSCLC) recommend anatomic resection, negative margins, examination of hilar/intrapulmonary lymph nodes, and examination of 3 or more mediastinal nodal stations. We examined the survival impact of these guidelines. Methods Population-based observational study using patient-level data from all curative-intent NSCLC resections from 2004–2013 at 11 institutions in 4 contiguous Dartmouth Hospital Referral Regions in 3 US states. We used an adjusted Cox proportional hazards model to assess the overall survival impact of attaining NCCN guidelines. Results Of 2,429 eligible resections,91% were anatomic, 94% had negative margins, 51% sampled hilar nodes, and 26% examined three or more mediastinal nodal stations. Only 17% of resections met all four criteria, however there was a significant increasing trend from 2% in 2004 to 39% in 2013 (p<0.001). Compared to patients whose surgery missed one or more parameters, the hazard ratio for patients whose surgery met all four criteria was 0.71 (95% confidence interval: 0.59–0.86, p<0.001). Margin status and the nodal staging parameters were most strongly linked with survival. Conclusions Attainment of NCCN surgical quality guidelines was low, but improving, over the past decade in this cohort from a high lung cancer mortality region of the US. The NCCN quality criteria, especially the nodal examination criteria, were strongly associated with survival. The quality of nodal examination should be a focus of quality improvement in NSCLC care. PMID:28366464

Recurrence in Region of Spared Parotid Gland After Definitive Intensity-Modulated Radiotherapy for Head and Neck Cancer

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

Cannon, Donald M.; Lee, Nancy Y.

2008-03-01

Purpose: To discuss the implications of three examples of periparotid recurrence after definitive intensity-modulated radiotherapy (IMRT) for head and neck cancer (HNC). Methods and Materials: We present 3 patients with HNC who underwent definitive IMRT with concurrent chemotherapy and later had treatment failure in or near a spared parotid gland. Two patients had bilateral multilevel nodal disease, and all had Level II nodal disease ipsilateral to the site of recurrence. The patients were treated using dose-painting IMRT with a dose of 70 Gy to the gross tumor volume and 59.4 Gy or 54 Gy to the high-risk or low-risk clinicalmore » tumor volume, respectively. The parotid glands were spared bilaterally. The patients had not undergone any surgical treatment for HNC before radiotherapy. Results: All patients had treatment failure in the region of a spared parotid gland. Failure in the 2 patients with bilateral multilevel nodal involvement occurred in the periparotid lymph nodes. The third patient developed a dermal metastasis near the tail of a spared parotid gland. On pretreatment imaging, the 2 patients with nodal failure had small nonspecific periparotid nodules that showed no hypermetabolic activity on positron emission tomography. Conclusion: For HNC patients receiving definitive IMRT, nonspecific positron emission tomography-negative periparotid nodules on pretreatment imaging should raise the index of suspicion for subclinical disease in the presence of multilevel or Level II nodal metastases. Additional evaluation of such nodules might be indicated before sparing the ipsilateral parotid gland.« less

Local opiate receptors in the sinoatrial node moderate vagal bradycardia.

PubMed

Farias, M; Jackson, K; Stanfill, A; Caffrey, J L

2001-02-20

Met-enkephalin-arg-phe (MEAP) interrupts vagal bradycardia when infused into the systemic circulation. This study was designed to locate the opiate receptors functionally responsible for this inhibition. Previous observations suggested that the receptors were most likely located in either intracardiac parasympathetic ganglia or the pre-junctional nerve terminals innervating the sinoatrial node. In this study 10 dogs were instrumented with a microdialysis probe inserted into the sinoatrial node. The functional position of the probe was tested by briefly introducing norepinephrine into the probe producing an increase in heart rate of more than 30 beats/min. Vagal stimulations were conducted at 0.5, 1.2 and 4 Hz during vehicle infusion (saline ascorbate). Cardiovascular responses during vagal stimulation were recorded on-line. MEAP was infused directly into the sinoatrial node via the microdialysis probe. The evaluation of vagal bradycardia was repeated during the nodal application of MEAP, diprenorphine (opiate antagonist), and diprenorphine co-infused with MEAP. MEAP introduced into the sinoatrial node via the microdialysis probe reduced vagal bradycardia by more than half. Simultaneous local nodal blockade of these receptors with the opiate antagonist, diprenorphine, eliminated the effect of MEAP demonstrating the participation by opiate receptors. Systemic infusions of MEAP produced a reduction in vagal bradycardia nearly identical to that observed during nodal administration. When local nodal opiate receptors were blocked with diprenorphine, the systemic effect of MEAP was eliminated. These data lead us to suggest that the opiate receptors responsible for the inhibition of vagal bradycardia are located within the sinoatrial node with few, if any, participating extra-nodal or ganglionic receptors.

Disrupted Nodal and Hub Organization Account for Brain Network Abnormalities in Parkinson’s Disease

PubMed Central

Koshimori, Yuko; Cho, Sang-Soo; Criaud, Marion; Christopher, Leigh; Jacobs, Mark; Ghadery, Christine; Coakeley, Sarah; Harris, Madeleine; Mizrahi, Romina; Hamani, Clement; Lang, Anthony E.; Houle, Sylvain; Strafella, Antonio P.

2016-01-01

The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson’s disease (PD). This study aimed to investigate functional changes in sensorimotor and cognitive networks in Parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls (HCs) and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the HC and patient groups. We found nodal and hub changes in patients compared with HCs, including the right pre-supplementary motor area (SMA), left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex (DLPFC), and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e., right pre-SMA and right mid-insula) displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral DLPFC possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of PD. PMID:27891090

Disrupted Nodal and Hub Organization Account for Brain Network Abnormalities in Parkinson's Disease.

PubMed

Koshimori, Yuko; Cho, Sang-Soo; Criaud, Marion; Christopher, Leigh; Jacobs, Mark; Ghadery, Christine; Coakeley, Sarah; Harris, Madeleine; Mizrahi, Romina; Hamani, Clement; Lang, Anthony E; Houle, Sylvain; Strafella, Antonio P

2016-01-01

The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson's disease (PD). This study aimed to investigate functional changes in sensorimotor and cognitive networks in Parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls (HCs) and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the HC and patient groups. We found nodal and hub changes in patients compared with HCs, including the right pre-supplementary motor area (SMA), left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex (DLPFC), and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e., right pre-SMA and right mid-insula) displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral DLPFC possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of PD.

Translational co-regulation of a ligand and inhibitor by a conserved RNA element

PubMed Central

Zaucker, Andreas; Nagorska, Agnieszka; Kumari, Pooja; Hecker, Nikolai; Wang, Yin; Huang, Sizhou; Cooper, Ledean; Sivashanmugam, Lavanya; VijayKumar, Shruthi; Brosens, Jan; Gorodkin, Jan

2018-01-01

Abstract In many organisms, transcriptional and post-transcriptional regulation of components of pathways or processes has been reported. However, to date, there are few reports of translational co-regulation of multiple components of a developmental signaling pathway. Here, we show that an RNA element which we previously identified as a dorsal localization element (DLE) in the 3′UTR of zebrafish nodal-related1/squint (ndr1/sqt) ligand mRNA, is shared by the related ligand nodal-related2/cyclops (ndr2/cyc) and the nodal inhibitors, lefty1 (lft1) and lefty2 mRNAs. We investigated the activity of the DLEs through functional assays in live zebrafish embryos. The lft1 DLE localizes fluorescently labeled RNA similarly to the ndr1/sqt DLE. Similar to the ndr1/sqt 3′UTR, the lft1 and lft2 3′UTRs are bound by the RNA-binding protein (RBP) and translational repressor, Y-box binding protein 1 (Ybx1), whereas deletions in the DLE abolish binding to Ybx1. Analysis of zebrafish ybx1 mutants shows that Ybx1 represses lefty1 translation in embryos. CRISPR/Cas9-mediated inactivation of human YBX1 also results in human NODAL translational de-repression, suggesting broader conservation of the DLE RNA element/Ybx1 RBP module in regulation of Nodal signaling. Our findings demonstrate translational co-regulation of components of a signaling pathway by an RNA element conserved in both sequence and structure and an RBP, revealing a ‘translational regulon’. PMID:29059375

Concurrent chemoradiotherapy with S-1 in patients with stage III-IV oral squamous cell carcinoma: A retrospective analysis of nodal classification based on the neck node level.

PubMed

Murakami, Ryuji; Semba, Akiko; Kawahara, Kenta; Matsuyama, Keiya; Hiraki, Akimitsu; Nagata, Masashi; Toya, Ryo; Yamashita, Yasuyuki; Oya, Natsuo; Nakayama, Hideki

2017-07-01

The aim of the present study was to retrospectively evaluate the treatment outcomes of concurrent chemoradiotherapy (CCRT) with S-1, an oral fluoropyrimidine anticancer agent, for advanced oral squamous cell carcinoma (SCC). The study population consisted of 47 patients with clinical stage III or IV oral SCC, who underwent CCRT with S-1. Pretreatment variables, including patient age, clinical stage, T classification, midline involvement of the primary tumor and nodal status, were analyzed as predictors of survival. In addition to the N classification (node-positive, multiple and contralateral), the prognostic impact of the level of nodal involvement was assessed. Nodal involvement was mainly observed at levels Ib and II; involvement at levels Ia and III-V was considered to be anterior and inferior extension, respectively, and was recorded as extensive nodal involvement (ENI). The 3-year overall survival (OS) and progression-free survival (PFS) rates were 37 and 27%, respectively. A finding of ENI was a significant factor for OS [hazard ratio (HR)=2.16; 95% confidence interval (CI): 1.03-4.55; P=0.038] and PFS (HR=2.65; 95% CI: 1.32-5.33; P=0.005); the 3-year OS and PFS rates in patients with vs. those without ENI were 23 vs. 50% and 9 vs. 43%, respectively. The other variables were not significant. Therefore, CCRT with S-1 may be an alternative treatment for advanced oral SCC; favorable outcomes are expected in patients without ENI.

Intensity-Modulated Radiation Therapy for the Treatment of Squamous Cell Anal Cancer With Para-aortic Nodal Involvement

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

Hodges, Joseph C.; Das, Prajnan, E-mail: PrajDas@mdanderson.or; Eng, Cathy

2009-11-01

Purpose: To determine the rates of toxicity, locoregional control, distant control, and survival in anal cancer patients with para-aortic nodal involvement, treated with intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy at a single institution. Methods and Materials: Between 2001 and 2007, 6 patients with squamous cell anal cancer and para-aortic nodal involvement were treated with IMRT and concurrent infusional 5-fluorouracil and cisplatin. The primary tumor was treated with a median dose of 57.5 Gy (range, 54-60 Gy), involved para-aortic, pelvic, and inguinal lymph nodes were treated with a median dose of 55 Gy (range, 50.5-55 Gy), and noninvolved nodal regions weremore » treated with a median dose of 45 Gy (range, 43.5-45 Gy). Results: After a median follow-up of 25 months, none of the patients had a recurrence at the primary tumor, pelvic/inguinal nodes, or para-aortic nodes, whereas 2 patients developed distant metastases to the liver. Four of the 6 patients are alive. The 3-year actuarial locoregional control, distant control, and overall survival rates were 100%, 56%, and 63%, respectively. Four of the 6 patients developed Grade 3 acute gastrointestinal toxicity during chemoradiation. Conclusions: Intensity-modulated radiotherapy and concurrent chemotherapy could potentially serve as definitive therapy in anal cancer patients with para-aortic nodal involvement. Adjuvant chemotherapy may be indicated in these patients, as demonstrated by the distant failure rates. These patients need to be followed carefully because of the potential for treatment-related toxicities.« less

Rationality of moduli space of torsion-free sheaves over reducible curve

NASA Astrophysics Data System (ADS)

Dey, Arijit; Suhas, B. N.

2018-06-01

Let M(2 , w ̲ , χ) be the moduli space of rank 2 torsion-free sheaves of fixed determinant and odd Euler characteristic over a reducible nodal curve with each irreducible component having utmost two nodal singularities. We show that in each irreducible component of M(2 , w ̲ , χ) , the closure of rank 2 vector bundles is rational.

Brady's Geothermal Field Nodal Seismometer Earthquake Data

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

Kurt Feigl

90-second records of data from 238 three-component nodal seismometer deployed at Bradys geothermal field. The time window catches an earthquake arrival. Earthquake data from USGS online catalog: Magnitude: 4.3 ml +/- 0.4 Location: 38.479 deg N 118.366 deg W +/- 0.7 km Depth: 9.9 km +/- 0.7 Date and Time: 2016-03-21 07:37:10.535 UTC

Identification and expression of Smads associated with TGF-beta/activin/nodal signaling pathways in the rainbow trout (Oncorhynuchus mykiss)

USDA-ARS?s Scientific Manuscript database

The Smad proteins are essential components of the TGF-beta/activin/nodal family signaling pathway. We report the identification and characterization of transcripts representing 3 receptor Smads (Smad2a, Smad2b, Smad3), 2 common Smads (Smad4a, Smad4b) and one inhibitory Smad (Smad7). Phylogenetic an...

Zebrafish hhex, nk2.1a, and pax2.1 regulate thyroid growth and differentiation downstream of Nodal-dependent transcription factors.

PubMed

Elsalini, Osama A; von Gartzen, Julia; Cramer, Matthias; Rohr, Klaus B

2003-11-01

During zebrafish development, the thyroid primordium initiates expression of molecular markers such as hhex and nk2.1a in the endoderm prior to pharynx formation. As expected for an endodermally derived organ, initiation of thyroid development depends on Nodal signalling. We find that it also depends on three downstream effectors of Nodal activity, casanova (cas), bonnie and clyde (bon), and faust (fau)/gata5. Despite their early Nodal-dependent expression in the endoderm, both hhex and nk2.1a are only required relatively late during thyroid development. In hhex and nk2.1a loss-of-function phenotypes, thyroid development is initiated and arrests only after the primordium has evaginated from the pharyngeal epithelium. Thus, like pax2.1, both hhex and nk2.1a have similarly late roles in differentiation or growth of thyroid follicular cells, and here, we show that all three genes act in parallel rather than in a single pathway. Our functional analysis suggests that these genes have similar roles as in mammalian thyroid development, albeit in a different temporal mode of organogenesis.

Time-Referenced Effects of an Internal vs. External Focus of Attention on Muscular Activity and Compensatory Variability

PubMed Central

Hossner, Ernst-Joachim; Ehrlenspiel, Felix

2010-01-01

The paralysis-by-analysis phenomenon, i.e., attending to the execution of one's movement impairs performance, has gathered a lot of attention over recent years (see Wulf, 2007, for a review). Explanations of this phenomenon, e.g., the hypotheses of constrained action (Wulf et al., 2001) or of step-by-step execution (Masters, 1992; Beilock et al., 2002), however, do not refer to the level of underlying mechanisms on the level of sensorimotor control. For this purpose, a “nodal-point hypothesis” is presented here with the core assumption that skilled motor behavior is internally based on sensorimotor chains of nodal points, that attending to intermediate nodal points leads to a muscular re-freezing of the motor system at exactly and exclusively these points in time, and that this re-freezing is accompanied by the disruption of compensatory processes, resulting in an overall decrease of motor performance. Two experiments, on lever sequencing and basketball free throws, respectively, are reported that successfully tested these time-referenced predictions, i.e., showing that muscular activity is selectively increased and compensatory variability selectively decreased at movement-related nodal points if these points are in the focus of attention. PMID:21833285

Comparative assessment of genetic and epigenetic variation among regenerants of potato (Solanum tuberosum) derived from long-term nodal tissue-culture and cell selection.

PubMed

Dann, Alison L; Wilson, Calum R

2011-04-01

Three long-term nodal tissued cultured Russet Burbank potato clones and nine thaxtomin A-treated regenerant lines, derived from the nodal lines, were assessed for genetic and epigenetic (in the form of DNA methylation) differences by AFLP and MSAP. The treated regenerant lines were originally selected for superior resistance to common scab disease and acceptable tuber yield in pot and field trials. The long-term, tissue culture clone lines exhibited genetic (8.75-15.63% polymorphisms) and epigenetic (12.56-26.13% polymorphisms) differences between them and may represent a stress response induced by normal plant growth disruption. The thaxtomin A-treated regenerant lines exhibited much higher significant (p < 0.05) genetic (2-29.38%) and epigenetic (45.22-51.76%) polymorphisms than the nodal cultured parent clones. Methylation-sensitive mutations accumulated within the regenerant lines are significantly correlated (p < 0.05) to disease resistance. However, linking phenotypic differences that could be of benefit to potato growers, to single gene sequence polymorphisms in a tetraploid plant such as the potato would be extremely difficult since it is assumed many desirable traits are under polygenic control.

Theoretical and experimental evidence for a nodal energy gap in MgB2

NASA Astrophysics Data System (ADS)

Agassi, Y. Dan; Oates, Daniel E.

2017-11-01

We present a phenomenological model that strongly suggests that the smaller of the two energy gaps in MgB2, the so-called π gap, contains nodal lines with a six-fold symmetry (i-wave). The model also indicates that the larger gap, the so-called σ gap, is conventional s-wave. The model is an extension of the BCS gap equation that accounts for the elastic anisotropy in MgB2 and the Coulomb repulsion. It is based on a phononic pairing mechanism and assumes no coupling between the two energy gaps in MgB2 at zero temperature. All of the parameters of the model, such as sound velocities and masses, are independently determined material constants. The results agree with a previous ad-hoc hypothesis that the π energy gap has six nodal lines. That hypothesis was motivated by low-temperature measurements of the surface impedance and intermodulation distortion in high-quality thin films. We briefly review experimental evidence in the literature that is relevant to the energy-gap symmetry. We find that the evidence from the literature for s-wave is inconclusive. Our finding is that the π gap has six nodal lines.

An amphioxus nodal gene (AmphiNodal) with early symmetrical expression in the organizer and mesoderm and later asymmetrical expression associated with left-right axis formation

NASA Technical Reports Server (NTRS)

Yu, Jr-Kai; Holland, Linda Z.; Holland, Nicholas D.

2002-01-01

The full-length sequence and zygotic expression of an amphioxus nodal gene are described. Expression is first detected in the early gastrula just within the dorsal lip of the blastopore in a region of hypoblast that is probably comparable with the vertebrate Spemann's organizer. In the late gastrula and early neurula, expression remains bilaterally symmetrical, limited to paraxial mesoderm and immediately overlying regions of the neural plate. Later in the neurula stage, all neural expression disappears, and mesodermal expression disappears from the right side. All along the left side of the neurula, mesodermal expression spreads into the left side of the gut endoderm. Soon thereafter, all expression is down-regulated except near the anterior and posterior ends of the animal, where transcripts are still found in the mesoderm and endoderm on the left side. At this time, expression also begins in the ectoderm on the left side of the head, in the region where the mouth later forms. These results suggest that amphioxus and vertebrate nodal genes play evolutionarily conserved roles in establishing Spemann's organizer, patterning the mesoderm rostrocaudally and setting up the asymmetrical left-right axis of the body.

Nodal liquids in extended t-J models and dynamical supersymmetry

NASA Astrophysics Data System (ADS)

Mavromatos, Nick E.; Sarkar, Sarben

2000-08-01

In the context of extended t-J models, with intersite Coulomb interactions of the form -V∑ninj, with ni denoting the electron number operator at site i, nodal liquids are discussed. We use the spin-charge separation ansatz as applied to the nodes of a d-wave superconducting gap. Such a situation may be of relevance to the physics of high-temperature superconductivity. We point out the possibility of existence of certain points in the parameter space of the model characterized by dynamical supersymmetries between the spinon and holon degrees of freedom, which are quite different from the symmetries in conventional supersymmetric t-J models. Such symmetries pertain to the continuum effective-field theory of the nodal liquid, and one's hope is that the ancestor lattice model may differ from the continuum theory only by renormalization-group irrelevant operators in the infrared. We give plausible arguments that nodal liquids at such supersymmetric points are characterized by superconductivity of Kosterlitz-Thouless type. The fact that quantum fluctuations around such points can be studied in a controlled way, probably makes such systems of special importance for an eventual nonperturbative understanding of the complex phase diagram of the associated high-temperature superconducting materials.

Nodal gap detection through polar angle-resolved density of states measurements in uniaxial superconductors

NASA Astrophysics Data System (ADS)

Tsutsumi, Yasumasa; Nomoto, Takuya; Ikeda, Hiroaki; Machida, Kazushige

2016-12-01

We propose a spectroscopic method to identify the nodal gap structure in unconventional superconductors. This method is best suited for locating the horizontal line node and for pinpointing the isolated point nodes by measuring polar angle (θ ) resolved zero-energy density of states N (θ ) . This is measured by specific heat or thermal conductivity at low temperatures under a magnetic field. We examine a variety of uniaxially symmetric nodal structures, including point and/or line nodes with linear and quadratic dispersions, by solving the Eilenberger equation in vortex states. It is found that (a) the maxima of N (θ ) continuously shift from the antinodal to the nodal direction (θn) as a field increases accompanying the oscillation pattern reversal at low and high fields. Furthermore, (b) local minima emerge next to θn on both sides, except for the case of the linear point node. These features are robust and detectable experimentally. Experimental results of N (θ ) performed on several superconductors, UPd2Al3,URu2Si2,CuxBi2Se3 , and UPt3, are examined and commented on in light of the present theory.

PET-NECK: a multicentre randomised Phase III non-inferiority trial comparing a positron emission tomography-computerised tomography-guided watch-and-wait policy with planned neck dissection in the management of locally advanced (N2/N3) nodal metastases in patients with squamous cell head and neck cancer.

PubMed

Mehanna, Hisham; McConkey, Chris C; Rahman, Joy K; Wong, Wai-Lup; Smith, Alison F; Nutting, Chris; Hartley, Andrew Gj; Hall, Peter; Hulme, Claire; Patel, Dharmesh K; Zeidler, Sandra Ventorin von; Robinson, Max; Sanghera, Bal; Fresco, Lydia; Dunn, Janet A

2017-04-01

Planned neck dissection (ND) after radical chemoradiotherapy (CRT) for locally advanced nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) remains controversial. Thirty per cent of ND specimens show histological evidence of tumour. Consequently, a significant proportion of clinicians still practise planned ND. Fludeoxyglucose positron emission tomography (PET)-computerised tomography (CT) scanning demonstrated high negative predictive values for persistent nodal disease, providing a possible alternative paradigm to ND. Evidence is sparse and drawn mainly from retrospective single-institution studies, illustrating the need for a prospective randomised controlled trial. To determine the efficacy and cost-effectiveness of PET-CT-guided surveillance, compared with planned ND, in a multicentre, prospective, randomised setting. A pragmatic randomised non-inferiority trial comparing PET-CT-guided watch-and-wait policy with the current planned ND policy in HNSCC patients with locally advanced nodal metastases and treated with radical CRT. Patients were randomised in a 1 : 1 ratio. Primary outcomes were overall survival (OS) and cost-effectiveness [incremental cost per incremental quality-adjusted life-year (QALY)]. Cost-effectiveness was assessed over the trial period using individual patient data, and over a lifetime horizon using a decision-analytic model. Secondary outcomes were recurrence in the neck, complication rates and quality of life. The recruitment of 560 patients was planned to detect non-inferior OS in the intervention arm with a 90% power and a type I error of 5%, with non-inferiority defined as having a hazard ratio (HR) of no higher than 1.50. An intention-to-treat analysis was performed by Cox's proportional hazards model. Thirty-seven head and neck cancer-treating centres (43 NHS hospitals) throughout the UK. Patients with locally advanced nodal metastases of oropharynx, hypopharynx, larynx, oral or occult HNSCC receiving CRT and fit for ND were recruited. Patients randomised to planned ND before or after CRT (control), or CRT followed by fludeoxyglucose PET-CT 10-12 weeks post CRT with ND only if PET-CT showed incomplete or equivocal response of nodal disease (intervention). Balanced by centre, planned ND timing, CRT schedule, disease site and the tumour, node, metastasis stage. In total, 564 patients were recruited (ND arm, n  = 282; and surveillance arm, n  = 282; 17% N2a, 61% N2b, 18% N2c and 3% N3). Eighty-four per cent had oropharyngeal cancer. Seventy-five per cent of tested cases were p16 positive. The median time to follow-up was 36 months. The HR for OS was 0.92 [95% confidence interval (CI) 0.65 to 1.32], indicating non-inferiority. The upper limit of the non-inferiority HR margin of 1.50, which was informed by patient advisors to the project, lies at the 99.6 percentile of this estimate ( p  = 0.004). There were no differences in this result by p16 status. There were 54 NDs performed in the surveillance arm, with 22 surgical complications, and 221 NDs in the ND arm, with 85 complications. Quality-of-life scores were slightly better in the surveillance arm. Compared with planned ND, PET-CT surveillance produced an incremental net health benefit of 0.16 QALYs (95% CI 0.03 to 0.28 QALYs) over the trial period and 0.21 QALYs (95% CI -0.41 to 0.85 QALYs) over the modelled lifetime horizon. Pragmatic randomised controlled trial with a 36-month median follow-up. PET-CT-guided active surveillance showed similar survival outcomes to ND but resulted in considerably fewer NDs, fewer complications and lower costs, supporting its use in routine practice. PET-CT surveillance is cost-effective in the short term, and long-term cost-effectiveness could be addressed in future work. Current Controlled Trials ISRCTN13735240. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 21, No. 17. See the NIHR Journals Library website for further project information.

Current transport across the pentacene/CVD-grown graphene interface for diode applications.

PubMed

Berke, K; Tongay, S; McCarthy, M A; Rinzler, A G; Appleton, B R; Hebard, A F

2012-06-27

We investigate the electronic transport properties across the pentacene/graphene interface. Current transport across the pentacene/graphene interface is found to be strikingly different from transport across pentacene/HOPG and pentacene/Cu interfaces. At low voltages, diodes using graphene as a bottom electrode display Poole–Frenkel emission, while diodes with HOPG and Cu electrodes are dominated by thermionic emission. At high voltages conduction is dominated by Poole–Frenkel emission for all three junctions. We propose that current across these interfaces can be accurately modeled by a combination of thermionic and Poole–Frenkel emission. Results presented not only suggest that graphene provides low resistive contacts to pentacene where a flat-laying orientation of pentacene and transparent metal electrodes are desired but also provides further understanding of the physics at the organic semiconductor/graphene interface.

Unusual presentation of Warthin variant of Papillary thyroid carcinoma with lymph nodal metastases in a patient of Graves' disease.

PubMed

Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga; Arun, B R

2015-01-01

Warthin-like Papillary thyroid carcinoma (WPTC) is a rare variant of papillary carcinoma of thyroid, PTC which derives its name by closely resembling Warthin's tumor of salivary gland. Hallmark histological feature of this variant is papillary folding lined by oncocytic neoplastic cells with clear nuclei and nuclear pseudoinclusions, accompanied by prominent lymphocytic infiltrate in the papillary stalks. It is thought to be one of those differentiated thyroid cancers with favorable prognosis. We report a case of Graves' disease with a cold nodule harboring WPTC with initial presentation of lymph nodal metastases. It is important to identify this peculiar variant of PTC as 5 to 10% of them undergo dedifferentiation and 30% have the lymph nodal metastases and extra thyroidal extension.

On configurational forces for gradient-enhanced inelasticity

NASA Astrophysics Data System (ADS)

Floros, Dimosthenis; Larsson, Fredrik; Runesson, Kenneth

2018-04-01

In this paper we discuss how configurational forces can be computed in an efficient and robust manner when a constitutive continuum model of gradient-enhanced viscoplasticity is adopted, whereby a suitably tailored mixed variational formulation in terms of displacements and micro-stresses is used. It is demonstrated that such a formulation produces sufficient regularity to overcome numerical difficulties that are notorious for a local constitutive model. In particular, no nodal smoothing of the internal variable fields is required. Moreover, the pathological mesh sensitivity that has been reported in the literature for a standard local model is no longer present. Numerical results in terms of configurational forces are shown for (1) a smooth interface and (2) a discrete edge crack. The corresponding configurational forces are computed for different values of the intrinsic length parameter. It is concluded that the convergence of the computed configurational forces with mesh refinement depends strongly on this parameter value. Moreover, the convergence behavior for the limit situation of rate-independent plasticity is unaffected by the relaxation time parameter.

[Parahisian atrial tachycardia or atrioventricular nodal reentrant tachycardia with tendon of Todaro breakthrough?].

PubMed

Orczykowski, Michał; Jaworska-Wilczyńska, Maria; Urbanek, Piotr; Bodalski, Robert; Derejko, Paweł; Gajek, Jacek; Hryniewiecki, Tomasz; Szumowski, Lukasz; Walczak, Franciszek

2010-08-01

We present a case of a 61 year-old woman with tachycardia originating close to the His bundle where radiofrequency (RF) ablation may bear potential risk of atrioventricular (AV) block. In this case report we discuss the possibility of a AV nodal reciprocating tachycardia with tendon of Todaro breakthrough. Patient was safely and effectively treated with RF catheter ablation.

Retrospective Analysis of Outcome Differences in Preoperative Concurrent Chemoradiation With or Without Elective Nodal Irradiation for Esophageal Squamous Cell Carcinoma

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

Hsu, Feng-Ming; Cancer Research Center, National Taiwan University College of Medicine, Taipei, Taiwan; Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan

2011-11-15

Purpose: To evaluate the efficacy and patterns of failure of elective nodal irradiation (ENI) in patients with esophageal squamous cell carcinoma (SCC) undergoing preoperative concurrent chemoradiation (CCRT) followed by radical surgery. Methods and Materials: We retrospectively studied 118 patients with AJCC Stage II to III esophageal SCC undergoing preoperative CCRT (median, 36 Gy), followed by radical esophagectomy. Of them, 73 patients (62%) had ENI and 45 patients (38%) had no ENI. Patients with ENI received radiotherapy to either supraclavicular (n = 54) or celiac (n = 19) lymphatics. Fifty-six patients (57%) received chemotherapy with paclitaxel plus cisplatin. The 3-year progression-freemore » survival, overall survival, and patterns of failure were analyzed. Distant nodal recurrence was classified into M1a and M1b regions. A separate analysis using matched cases was conducted. Results: The median follow-up was 38 months. There were no differences in pathological complete response rate (p = 0.12), perioperative mortality rate (p = 0.48), or delayed Grade 3 or greater cardiopulmonary toxicities (p = 0.44), between the groups. More patients in the non-ENI group had M1a failure than in the ENI group, with 3-year rates of 11% and 3%, respectively (p = 0.05). However, the 3-year isolated distant nodal (M1a + M1b) failure rates were not different (ENI, 10%; non-ENI, 14%; p = 0.29). In multivariate analysis, pathological nodal status was the only independent prognostic factor associated with overall survival (hazard ratio = 1.78, p = 0.045). The 3-year overall survival and progression-free survival were 45% and 45%, respectively, in the ENI group, and 52% and 43%, respectively, in the non-ENI group (p = 0.31 and 0.89, respectively). Matched cases analysis did not show a statistical difference in outcomes between the groups. Conclusions: ENI reduced the M1a failure rate but was not associated with improved outcomes in patients undergoing preoperative CCRT for esophageal SCC. Pathological nodal metastasis predicted poor outcome.« less

Pediatric and adolescent lymphoma: comparison of whole-body STIR half-Fourier RARE MR imaging with an enhanced PET/CT reference for initial staging.

PubMed

Punwani, Shonit; Taylor, Stuart A; Bainbridge, Alan; Prakash, Vineet; Bandula, Steven; De Vita, Enrico; Olsen, Oystein E; Hain, Sharon F; Stevens, Nicola; Daw, Stephen; Shankar, Ananth; Bomanji, Jamshed B; Humphries, Paul D

2010-04-01

To compare the diagnostic performance of rapid whole-body anatomic magnetic resonance (MR) staging of pediatric and adolescent lymphoma to an enhanced positron emission tomographic (PET)/computed tomographic (CT) reference standard. Ethical permission was given by the University College London Hospital ethics committee, and informed written consent was obtained from all participants and/or parents or guardians. Thirty-one subjects (age range, 7.3-18.0 years; 18 male, 11 female) with histologically proved lymphoma were prospectively recruited. Pretreatment staging was performed with whole-body short inversion time inversion-recovery (STIR) half-Fourier rapid acquisition with relaxation enhancement (RARE) MR imaging, fluorine 18 fluorodeoxyglucose PET/CT, and contrast agent-enhanced chest CT. Twenty-six subjects had posttreatment PET/CT and compromised our final cohort. Eleven nodal and 11 extranodal sites per patient were assessed on MR imaging by two radiologists in consensus, with a nodal short-axis threshold of >1 cm and predefined extranodal positivity criteria. The same sites were independantly evaluated by two nuclear medicine physicians on PET/CT images. Disease positivity was defined as a maximum standardized uptake value >2.5 or nodal size >1 cm. An unblinded expert panel reevaluated the imaging findings, removing perceptual errors, and derived an enhanced PET/CT reference standard (taking into account chest CT and 3-month follow-up imaging) against which the reported and intrinsic performance of MR imaging was assessed by using the kappa statistic. There was very good agreement between MR imaging and the enhanced PET/CT reference standard for nodal and extranodal staging (kappa = 0.96 and 0.86, respectively) which improved following elimination of perceptual errors (kappa = 0.97 and 0.91, respectively). The sensitivity and specificity of MR imaging (following removal of perceptual error) were 98% and 99%, respectively, for nodal disease and 91% and 99%, respectively, for extranodal disease. Whole-body STIR half-Fourier RARE MR imaging of pediatric and adolescent lymphoma can accurately depict nodal and extranodal disease and may provide an alternative nonionizing imaging method for anatomic disease assessment at initial staging. RSNA, 2010

SU-E-T-157: Evaluation and Comparison of Doses to Pelvic Lymph Nodes and to Point B with 3D Image Guided Treatment Planning for High Dose Brachytherapy for Treatment of Cervical Cancer

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

Bhandare, N.

2014-06-01

Purpose: To estimate and compare the doses received by the obturator, external and internal iliac lymph nodes and point Methods: CT-MR fused image sets of 15 patients obtained for each of 5 fractions of HDR brachytherapy using tandem and ring applicator, were used to generate treatment plans optimized to deliver a prescription dose to HRCTV-D90 and to minimize the doses to organs at risk (OARs). For each set of image, target volume (GTV, HRCTV) OARs (Bladder, Rectum, Sigmoid), and both left and right pelvic lymph nodes (obturator, external and internal iliac lymph nodes) were delineated. Dose-volume histograms (DVH) were generatedmore » for pelvic nodal groups (left and right obturator group, internal and external iliac chains) Per fraction DVH parameters used for dose comparison included dose to 100% volume (D100), and dose received by 2cc (D2cc), 1cc (D1cc) and 0.1 cc (D0.1cc) of nodal volume. Dose to point B was compared with each DVH parameter using 2 sided t-test. Pearson correlation were determined to examine relationship of point B dose with nodal DVH parameters. Results: FIGO clinical stage varied from 1B1 to IIIB. The median pretreatment tumor diameter measured on MRI was 4.5 cm (2.7– 6.4cm).The median dose to bilateral point B was 1.20 Gy ± 0.12 or 20% of the prescription dose. The correlation coefficients were all <0.60 for all nodal DVH parameters indicating low degree of correlation. Only 2 cc of obturator nodes was not significantly different from point B dose on t-test. Conclusion: Dose to point B does not adequately represent the dose to any specific pelvic nodal group. When using image guided 3D dose-volume optimized treatment nodal groups should be individually identified and delineated to obtain the doses received by pelvic nodes.« less

SU-F-P-52: A Meta-Analysis of Controlled Clinical Trials Comparing Elective Nodal Irradiation with Involved-Field Irradiation for Conformal Or Intensity-Modulated Radiotherapy in Patients with Esophageal Cancer

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

Bai, W; Zhang, R; Zhou, Z

Purpose: To compare elective nodal irradiation with involved-field irradiation for three-dimensional conformal radiotherapy or intensity-modulated radiotherapy in patients with esophageal cancer by a metaanalysis. Methods: Wanfang, CNKI, VIP, CBM databases, PubMed, Embase and Cochrane Library were searched to identify the controlled clinical trials of elective nodal irradiation with involved-field irradiation for three-dimensional conformal radiotherapy or intensity-modulated radiotherapy in patients with esophageal cancer. The obtained data were analyzed using Stata 11.0. The difference between two groups was estimated by calculating the odds ratio (OR) with 95% confidence interval (95% CI). Results: A total of 12 controlled clinical trials involving 1095 esophagealmore » cancer patients, which were selected according to inclusion and exclusion criteria, were included in this meta-analysis. The meta-analysis showed that the elective nodal irradiation group reduced the rates of out-field failure comparing with involved-field irradiation group (OR=3.727, P=0.007). However, the rates of ≥grades 3 acute radiation pneumonitis and esophagitis were significantly higher in the elective nodal irradiation group than in the involved-field irradiation group (OR=0.348, P=0.001, OR=0.385, P=0.000). 1-, 2-, 3-year local control rates (OR=0.966, P=0.837, OR=0.946, P=0.781; OR=0.732P=0.098) and 1-, 3-, 5-year survival rates were similar in the two groups ( OR=0.966, P=0.837; OR=0.946, P=0.781; OR=0.732, P=0.098; OR=0.952, P=0.756; OR=1.149, P=0.422; OR=0.768, P=0.120). It is the same with the rates of distant metastasis (OR=0.986, P=0.937). Conclusion: Compared with involved-field irradiation, the elective nodal irradiation can reduce the rates of out-field failure for three-dimensional conformal radiotherapy or intensity-modulated radiotherapy in patients with esophageal cancer. However, its advantage of local control and survival rates is not obvious and it increases the incidence of toxicities.« less

Retrospective analysis of outcome differences in preoperative concurrent chemoradiation with or without elective nodal irradiation for esophageal squamous cell carcinoma.

PubMed

Hsu, Feng-Ming; Lee, Jang-Ming; Huang, Pei-Ming; Lin, Chia-Chi; Hsu, Chih-Hung; Tsai, Yu-Chieh; Lee, Yung-Chie; Chia-Hsien Cheng, Jason

2011-11-15

To evaluate the efficacy and patterns of failure of elective nodal irradiation (ENI) in patients with esophageal squamous cell carcinoma (SCC) undergoing preoperative concurrent chemoradiation (CCRT) followed by radical surgery. We retrospectively studied 118 patients with AJCC Stage II to III esophageal SCC undergoing preoperative CCRT (median, 36 Gy), followed by radical esophagectomy. Of them, 73 patients (62%) had ENI and 45 patients (38%) had no ENI. Patients with ENI received radiotherapy to either supraclavicular (n = 54) or celiac (n = 19) lymphatics. Fifty-six patients (57%) received chemotherapy with paclitaxel plus cisplatin. The 3-year progression-free survival, overall survival, and patterns of failure were analyzed. Distant nodal recurrence was classified into M1a and M1b regions. A separate analysis using matched cases was conducted. The median follow-up was 38 months. There were no differences in pathological complete response rate (p = 0.12), perioperative mortality rate (p = 0.48), or delayed Grade 3 or greater cardiopulmonary toxicities (p = 0.44), between the groups. More patients in the non-ENI group had M1a failure than in the ENI group, with 3-year rates of 11% and 3%, respectively (p = 0.05). However, the 3-year isolated distant nodal (M1a + M1b) failure rates were not different (ENI, 10%; non-ENI, 14%; p = 0.29). In multivariate analysis, pathological nodal status was the only independent prognostic factor associated with overall survival (hazard ratio = 1.78, p = 0.045). The 3-year overall survival and progression-free survival were 45% and 45%, respectively, in the ENI group, and 52% and 43%, respectively, in the non-ENI group (p = 0.31 and 0.89, respectively). Matched cases analysis did not show a statistical difference in outcomes between the groups. ENI reduced the M1a failure rate but was not associated with improved outcomes in patients undergoing preoperative CCRT for esophageal SCC. Pathological nodal metastasis predicted poor outcome. Copyright © 2011 Elsevier Inc. All rights reserved.

A meta-analysis of human-system interfaces in unmanned aerial vehicle (UAV) swarm management.

PubMed

Hocraffer, Amy; Nam, Chang S

2017-01-01

A meta-analysis was conducted to systematically evaluate the current state of research on human-system interfaces for users controlling semi-autonomous swarms composed of groups of drones or unmanned aerial vehicles (UAVs). UAV swarms pose several human factors challenges, such as high cognitive demands, non-intuitive behavior, and serious consequences for errors. This article presents findings from a meta-analysis of 27 UAV swarm management papers focused on the human-system interface and human factors concerns, providing an overview of the advantages, challenges, and limitations of current UAV management interfaces, as well as information on how these interfaces are currently evaluated. In general allowing user and mission-specific customization to user interfaces and raising the swarm's level of autonomy to reduce operator cognitive workload are beneficial and improve situation awareness (SA). It is clear more research is needed in this rapidly evolving field. Copyright © 2016 Elsevier Ltd. All rights reserved.

High concentration effects of neutral-potential-well interface traps on recombination dc current-voltage lineshape in metal-oxide-silicon transistors

NASA Astrophysics Data System (ADS)

Chen, Zuhui; Jie, Bin B.; Sah, Chih-Tang

2008-11-01

Steady-state Shockley-Read-Hall kinetics is employed to explore the high concentration effect of neutral-potential-well interface traps on the electron-hole recombination direct-current current-voltage (R-DCIV) properties in metal-oxide-silicon field-effect transistors. Extensive calculations include device parameter variations in neutral-trapping-potential-well electron interface-trap density NET (charge states 0 and -1), dopant impurity concentration PIM, oxide thickness Xox, forward source/drain junction bias VPN, and transistor temperature T. It shows significant distortion of the R-DCIV lineshape by the high concentrations of the interface traps. The result suggests that the lineshape distortion observed in past experiments, previously attributed to spatial variation in surface impurity concentration and energy distribution of interface traps in the silicon energy gap, can also arise from interface-trap concentration along surface channel region.

Preculturing effect of thidiazuron on in vitro shoot multiplication and micropropagation round in Capparis decidua (Forsk.) an important multipurpose plant.

PubMed

Bukhari, Najat A W; Siddique, Iram; Perveen, Kahkashan

2016-09-01

An efficient protocol was developed for clonal multiplication of an important shrub: Capparis decidua (Forsk.) Edgew, through in vitro shoot induction and multiplication from nodal explants. Pretreatment of nodal explants in a liquid Murashige and Skoog (MS) medium augmented with various thidiazuron (TDZ) concentrations at relatively high levels (5-100 μM) for different time duration (4, 8, 12 and 16 d), proved a significant approach for in vitro shoot production. After an initial exposure time to TDZ, nodal explants were inoculated onto a MS basal medium devoid of TDZ for further induction and proliferation. The highest regeneration rate (85%), average number of shoots/explant (8.7 ± 0.22) and maximum shoot length (3.9 ± 0.33 cm) were obtained from the nodal explants exposed to 50 μM TDZ for 8 d. The nodal explants excised from the proliferated cultures of TDZ (50 μM) for 8 d were used as explants and showed an enhancement rate after next three round of in vitro propagation. Best results for rooting was obtained by ex vitro treatment of shoots with 200 μM indole-3-butyric acid (IBA) for 20 min. as it produced an average of 5.7 ± 0.41 roots per microshoot with 4.4 ± 0.39 cm root length in 84% shoots. Different planting substrates was tested for maximum survival of hardening off micropropagated plantlets and soilrite proved most effective than others as 97.1 ± 7.21 plantlets survived. All micropropagated plants grew well in natural conditions and showed similar morphology to the mother plant.

Depth of invasion, size and number of metastatic nodes predicts extracapsular spread in early oral cancers with occult metastases.

PubMed

Mair, Manish D; Shetty, Rathan; Nair, Deepa; Mathur, Yash; Nair, Sudhir; Deshmukh, Anuja; Thiagarajan, Shiva; Pantvaidya, Gouri; Lashkar, Sarbani; Prabhash, Kumar; Chaukar, Devendra; Pai, Prathmesh; Cruz, Anil D; Chaturvedi, Pankaj

2018-06-01

Presence of extracapsular spread (ECS) significantly decreases survival in oral cancer patients. Considering its prognostic impact, we have studied the incidence and factors predicting ECS in clinically node negative early oral cancers. We performed a retrospective chart review of 354 treatment naïve clinically node negative early oral cancer patients operated between 2012 and 2014. Chi-square test and logistic regression were used for identifying predictors of ECS, while cox-regression test was used for survival analysis. The incidence of occult nodal metastasis was 28.5% (101/354). Among them, ECS was seen in 15.3%(54/354) patients. The incidence of ECS in T1 and T2 lesion was 13.4% (21/157) and 16.8% (33/197), respectively. The overall incidence of ECS was 48% and 29% in lymph nodes smaller than 10 mm and 5 mm respectively. We found that tumor depth of invasion (>5 mm; p-0.027) and node (metastatic) size >15 mm (p-0.018) were significant predictors of ECS. p N2b disease was seen in 41/354 (11.6%) of which 31/354 (8.7%) had ECS, i.e. 75.6% of pN2b patients been ECS positive (p-0.000). The 3-year OS of patients without nodal metastasis, nodal metastasis without ECS and nodal metastasis with ECS was 88.4%, 66.9% and 59.2% (p-0.000) respectively. A significant number of patients with metastatic nodal size less than 1 cm have ECS which suggests aggressive behavior of the primary tumor. Thus, elective neck dissection is the only way of detecting ECS in these patients which may warrant treatment intensification. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sentinel lymph node mapping reduces practice pattern variations in surgical staging for endometrial adenocarcinoma: A before and after study.

PubMed

Liu, Christina Y; Elias, Kevin M; Howitt, Brooke E; Lee, Larissa J; Feltmate, Colleen M

2017-05-01

To examine the effects of universal sentinel lymph node mapping on the use of nodal staging in endometrial adenocarcinoma. Two approaches to laparoscopic staging for endometrial adenocarcinoma were compared using a before and after study design. The before cohort underwent selective lymphadenectomy from January 1, 2014-October 1, 2015 while the after cohort underwent universal sentinel lymph node (SLN) mapping from October 2, 2015-September 29, 2016. The before cohort comprised 215 patients and the after cohort 166 patients. In women undergoing SLN mapping, a sentinel node was identified at least unilaterally in 146/153 cases (95.4%), and bilaterally in 114/153 (74.5%) of cases. Pelvic nodes were removed in 35.8% of the before cohort versus 92.2% of the after cohort (p<0.0001) with more nodal evaluation among both low risk (9.6% vs. 91%, p<0.0001) and high risk cases (66% vs. 94%, p<0.0001). While the proportion of low risk cases diagnosed with nodal involvement did not significantly change (0.9% to 3.1%, p=0.32), there was a trend toward more diagnoses of nodal involvement in high risk cases (5% to 13.2%, p=0.06). Mean number of pelvic lymph nodes removed (15 vs. 4, p<0.0001), mean operative time (181min vs. 137min, p<0.0001), estimated blood loss (80ml vs. 56ml, p=0.004), and rate of post-operative complications (13% vs. 5.2%, p=0.04) all decreased after the adoption of SLN dissection. Universal sentinel lymph node dissection for laparoscopic endometrial cancer staging reduces heterogeneity in surgeon staging practice, increases nodal detection, and lowers post-operative complications. Copyright © 2017 Elsevier Inc. All rights reserved.

Surgery has a key role for quality assurance of colorectal cancer screening programs: impact of the third level multidisciplinary team on lymph nodal staging.

PubMed

Bianco, Francesco; De Franciscis, Silvia; Belli, Andrea; Di Lena, Maria; Avallone, Antonio; Bianco, Maria Antonia; Di Marzo, Sabato; Gigli, Letizia; Rotondano, Gianluca; Spena, Silvana Russo; Tatangelo, Fabiana; Tempesta, Alfonso; Romano, Giovanni Maria

2016-03-01

From 2011 to 2013 in the area of the Naples 3 public health district (ASL-NA3), a colorectal cancer screening program (CCSP) was developed. In order to stress the need of quality assurance procedures for surgery and pathology, a third level oncologic pathway was added and set up at a referral colorectal cancer center (RC). Lymph nodal (LN) harvesting, as a process indicator, and nodal positivity were adopted for an interim analysis. The program was implemented by a series of audit meetings and a double type of multidisciplinary team (MDT): "horizontal" and "vertical." Three hundred and forty colorectal cancer (CRC) patients underwent surgery: 119 chose to be operated at the RC (Gr In), 65 were operated at 22 district hospitals (DH) (Gr Out), and 156 symptomatic not screened patients were operated at the RC (Gr Sym). Statistical analysis revealed differences between Gr In and Gr Out colon groups both for LN harvesting (median of 26 and 11, respectively, P = 0.0001), and for nodal positivity after the first screening round (34.78 and 19.45%, respectively, P = 0.0169). Results were all the more significant in a subset analysis on early T stage colon subgroups (In vs Out) both for LN harvesting (P < 0.0001) and nodal positivity (P < 0.0001). xSignificant differences between RC and DHs were found, particularly for early-stage CRC patients. LN harvesting should be considered as a surrogate marker of quality assurance for at least screening hospitals for "minimum best" standard of care. This should lead to set up a third level in any CCSP.

Quantification of incidental mediastinal and hilar irradiation delivered during definitive stereotactic body radiation therapy for peripheral non-small cell lung cancer

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

Martin, Kate L.; Gomez, Jorge; Nazareth, Daryl P.

2012-07-01

To determine the amount of incidental radiation dose received by the mediastinal and hilar nodes for patients with non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). Fifty consecutive patients with NSCLC, treated using an SBRT technique, were identified. Of these patients, 38 had a prescription dose of 60 Gy in 20-Gy fractions and were eligible for analysis. For each patient, ipsilateral upper (level 2) and lower (level 4) paratracheal, and hilar (level 10) nodal regions were contoured on the planning computed tomography (CT) images. Using the clinical treatment plan, dose and volume calculations were performed retrospectivelymore » for each nodal region. SBRT to upper lobe tumors resulted in an average total ipsilateral mean dose of between 5.2 and 7.8 Gy for the most proximal paratracheal nodal stations (2R and 4R for right upper lobe lesions, 2L and 4L for left upper lobe lesions). SBRT to lower lobe tumors resulted in an average total ipsilateral mean dose of between 15.6 and 21.5 Gy for the most proximal hilar nodal stations (10R for right lower lobe lesions, 10 l for left lower lobe lesions). Doses to more distal nodes were substantially lower than 5 Gy. The often substantial incidental irradiation, delivered during SBRT for peripheral NSCLC of the lower lobes to the most proximal hilar lymph nodes may be therapeutic for low-volume, subclinical nodal disease. Treatment of peripheral upper lobe lung tumors delivers less incidental irradiation to the paratracheal lymph nodes with lower likelihood of therapeutic benefit.« less

Radiation Field Design in the ACOSOG Z0011 (Alliance) Trial

PubMed Central

Jagsi, Reshma; Chadha, Manjeet; Moni, Janaki; Ballman, Karla; Laurie, Fran; Buchholz, Thomas A.; Giuliano, Armando; Haffty, Bruce G.

2014-01-01

Purpose ACOSOG Z0011 established that axillary lymph node dissection (ALND) is unnecessary in patients with breast cancer with one to two positive sentinel lymph nodes (SLNs) who undergo lumpectomy, radiotherapy (RT), and systemic therapy. We sought to ascertain RT coverage of the regional nodes in that trial. Methods We evaluated case report forms completed 18 months after enrollment. From 2012 to 2013, we collected all available detailed RT records for central review. Results Among 605 patients with completed case report forms, 89% received whole-breast RT. Of these, 89 (15%) were recorded as also receiving treatment to the supraclavicular region. Detailed RT records were obtained for 228 patients, of whom 185 (81.1%) received tangent-only treatment. Among 142 with sufficient records to evaluate tangent height, high tangents (cranial tangent border ≤ 2 cm from humeral head) were used in 50% of patients (33 of 66) randomly assigned to ALND and 52.6% (40 of 76) randomly assigned to SLND. Of the 228 patients with records reviewed, 43 (18.9%) received directed regional nodal RT using ≥ three fields: 22 in the ALND arm and 21 in the SLND arm. Those receiving directed nodal RT had greater nodal involvement (P < .001) than those who did not. Overall, there was no significant difference between treatment arms in the use of protocol-prohibited nodal fields. Conclusion Most patients treated in Z0011 received tangential RT alone, and some received no RT at all. Some patients received directed nodal irradiation via a third field. Further research is necessary to determine the optimal RT approach in patients with low-volume axillary disease treated with SLND alone. PMID:25135994

Prophylactic Level VII Nodal Dissection as a Prognostic Factor in Papillary Thyroid Carcinoma: a Pilot Study of 27 Patients.

PubMed

Fayek, Ihab Samy

2015-01-01

Prognostic value of prophylactic level VII nodal dissection in papillary thyroid carcinoma has been highlighted. A total of 27 patients with papillary thyroid carcinoma with N0 neck underwent total thyroidectomy with level VI and VII nodal dissection through same collar neck incision. Multicentricity, bilaterality, extrathyroidal extension, level VI and VII lymph nodes were studied as separate and independent prognostic factors for DFS at 24 months. 21 females and 6 males with a mean age of 34.6 years old, tumor size was 5-24 mm. (mean 12.4 mm.), multicentricity in 11 patients 2-4 foci (mean 2.7), bilaterality in 8 patients and extrathyroidal extension in 8 patients. Dissected level VI LNs 2-8 (mean 5 LNs) and level VII LNs 1-4 (mean 1.9). Metastatic level VI LNs 0-3 (mean 1) and level VII LNs 0-2 (mean 0.5). Follow-up from 6-51 months (mean 25.6) with 7 patients showed recurrence (3 local and 4 distant). Cumulative DFS at 24 months was 87.8% and was significantly affected in relation to bilaterality (p-value<0.001), extrathyroidal extension (p-value<0.001), level VI positive ((p-value<0.001) and level VII positive ((p-value<0.001) LNs. No recurrences were detected during the follow-up period in the absence of level VI and level VII nodal involvement. Level VII prophylactic nodal dissection is an important and integral prognostic factor in papillary thyroid carcinoma. A larger multicenter study is crucial to reach a satisfactory conclusion about the necessity and safety of this approach.

Computing an upper bound on contact stress with surrogate duality

NASA Astrophysics Data System (ADS)

Xuan, Zhaocheng; Papadopoulos, Panayiotis

2016-07-01

We present a method for computing an upper bound on the contact stress of elastic bodies. The continuum model of elastic bodies with contact is first modeled as a constrained optimization problem by using finite elements. An explicit formulation of the total contact force, a fraction function with the numerator as a linear function and the denominator as a quadratic convex function, is derived with only the normalized nodal contact forces as the constrained variables in a standard simplex. Then two bounds are obtained for the sum of the nodal contact forces. The first is an explicit formulation of matrices of the finite element model, derived by maximizing the fraction function under the constraint that the sum of the normalized nodal contact forces is one. The second bound is solved by first maximizing the fraction function subject to the standard simplex and then using Dinkelbach's algorithm for fractional programming to find the maximum—since the fraction function is pseudo concave in a neighborhood of the solution. These two bounds are solved with the problem dimensions being only the number of contact nodes or node pairs, which are much smaller than the dimension for the original problem, namely, the number of degrees of freedom. Next, a scheme for constructing an upper bound on the contact stress is proposed that uses the bounds on the sum of the nodal contact forces obtained on a fine finite element mesh and the nodal contact forces obtained on a coarse finite element mesh, which are problems that can be solved at a lower computational cost. Finally, the proposed method is verified through some examples concerning both frictionless and frictional contact to demonstrate the method's feasibility, efficiency, and robustness.

A comparison of an A1 adenosine receptor agonist (CVT-510) with diltiazem for slowing of AV nodal conduction in guinea-pig

PubMed Central

Snowdy, Stephen; Liang, Hui Xiu; Blackburn, Brent; Lum, Robert; Nelson, Marek; Wang, Lisa; Pfister, Jürg; Sharma, Bhavender P; Wolff, Andrew; Belardinelli, Luiz

1999-01-01

The purpose of this study was to compare the pharmacological properties (i.e. the AV nodal depressant, vasodilator, and inotropic effects) of two AV nodal blocking agents belonging to different drug classes; a novel A1 adenosine receptor (A1 receptor) agonist, N-(3(R)-tetrahydrofuranyl)-6-aminopurine riboside (CVT-510), and the prototypical calcium channel blocker diltiazem.In the atrial-paced isolated heart, CVT-510 was approximately 5 fold more potent to prolong the stimulus-to-His bundle (S–H interval), a measure of slowing AV nodal conduction (EC50=41 nM) than to increase coronary conductance (EC50=200 nM). At concentrations of CVT-510 (40 nM) and diltiazem (1 μM) that caused equal prolongation of S–H interval (∼10 ms), diltiazem, but not CVT-510, significantly reduced left ventricular developed pressure (LVP) and markedly increased coronary conductance. CVT-510 shortened atrial (EC50=73 nM) but not the ventricular monophasic action potentials (MAP).In atrial-paced anaesthetized guinea-pigs, intravenous infusions of CVT-510 and diltiazem caused nearly equal prolongations of P–R interval. However, diltiazem, but not CVT-510, significantly reduced mean arterial blood pressure.Both CVT-510 and diltiazem prolonged S–H interval, i.e., slowed AV nodal conduction. However, the A1 receptor-selective agonist CVT-510 did so without causing the negative inotropic, vasodilator, and hypotensive effects associated with diltiazem. Because CVT-510 did not affect the ventricular action potential, it is unlikely that this agonist will have a proarrythmic action in ventricular myocardium. PMID:10051130

A viscoelastic higher-order beam finite element

NASA Technical Reports Server (NTRS)

Johnson, Arthur R.; Tressler, Alexander

1996-01-01

A viscoelastic internal variable constitutive theory is applied to a higher-order elastic beam theory and finite element formulation. The behavior of the viscous material in the beam is approximately modeled as a Maxwell solid. The finite element formulation requires additional sets of nodal variables for each relaxation time constant needed by the Maxwell solid. Recent developments in modeling viscoelastic material behavior with strain variables that are conjugate to the elastic strain measures are combined with advances in modeling through-the-thickness stresses and strains in thick beams. The result is a viscous thick-beam finite element that possesses superior characteristics for transient analysis since its nodal viscous forces are not linearly dependent an the nodal velocities, which is the case when damping matrices are used. Instead, the nodal viscous forces are directly dependent on the material's relaxation spectrum and the history of the nodal variables through a differential form of the constitutive law for a Maxwell solid. The thick beam quasistatic analysis is explored herein as a first step towards developing more complex viscoelastic models for thick plates and shells, and for dynamic analyses. The internal variable constitutive theory is derived directly from the Boltzmann superposition theorem. The mechanical strains and the conjugate internal strains are shown to be related through a system of first-order, ordinary differential equations. The total time-dependent stress is the superposition of its elastic and viscous components. Equations of motion for the solid are derived from the virtual work principle using the total time-dependent stress. Numerical examples for the problems of relaxation, creep, and cyclic creep are carried out for a beam made from an orthotropic Maxwell solid.

Effect of Radiotherapy Dose and Volume on Relapse in Merkel Cell Cancer of the Skin

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

Foote, Matthew, E-mail: matthew_foote@health.qld.gov.a; Harvey, Jennifer; Porceddu, Sandro

Purpose: To assess the effect of radiotherapy (RT) dose and volume on relapse patterns in patients with Stage I-III Merkel cell carcinoma (MCC). Patients and Methods: This was a retrospective analysis of 112 patients diagnosed with MCC between January 2000 and December 2005 and treated with curative-intent RT. Results: Of the 112 evaluable patients, 88% had RT to the site of primary disease for gross (11%) or subclinical (78%) disease. Eighty-nine percent of patients had RT to the regional lymph nodes; in most cases (71%) this was for subclinical disease in the adjuvant or elective setting, whereas 21 patients (19%)more » were treated with RT to gross nodal disease. With a median follow-up of 3.7 years, the 2-year and 5-year overall survival rates were 72% and 53%, respectively, and the 2-year locoregional control rate was 75%. The in-field relapse rate was 3% for primary disease, and relapse was significantly lower for patients receiving {>=}50Gy (hazard ratio [HR] = 0.22; 95% confidence interval [CI], 0.06-0.86). Surgical margins did not affect the local relapse rate. The in-field relapse rate was 11% for RT to the nodes, with dose being significant for nodal gross disease (HR = 0.24; 95% CI, 0.07-0.87). Patients who did not receive elective nodal RT had a much higher rate of nodal relapse compared with those who did (HR = 6.03; 95% CI, 1.34-27.10). Conclusion: This study indicates a dose-response for subclinical and gross MCC. Doses of {>=}50Gy for subclinical disease and {>=}55Gy for gross disease should be considered. The draining nodal basin should be treated in all patients.« less

Radiofrequency ablation versus cryoablation for atrioventricular nodal re-entrant tachycardia in children: a value comparison.

PubMed

Oster, Matthew E; Yang, Zhou; Stewart-Huey, Kay; Glanville, Michelle; Porter, Arlene; Campbell, Robert; Webb, Brad; Strieper, Margaret

2017-03-01

It is unclear whether cryoablation or radiofrequency ablation offers better value for treating atrioventricular nodal re-entrant tachycardia in children. We aimed to compare the value of these procedures for treating atrioventricular nodal re-entrant tachycardia in children, with value being outcomes relative to costs. We performed a retrospective cohort study of all atrioventricular nodal re-entrant tachycardia ablations for children (age⩽18 years) from July, 2009 to June, 2011 at our institution. Costs included fixed costs, miscellaneous hospital costs, and labour costs, and key outcomes were acute and long-term success (6 months) of the ablations. We conducted T-tests and regression analyses to investigate the associations between the ablation procedure type and the cost and success of the ablations. Of 96 unique cases performed by three paediatric electrophysiologists, 48 were cryoablation only, 42 radiofrequency ablation only, and six were a combination. Acute success was 100% for the cryoablation only and radiofrequency ablation only cases and 83% for the combination cases. There were no notable adverse events. The average total cost was $9636 for cryoablation cases, $9708 for radiofrequency ablation cases, and $10,967 for combination cases (p=0.51 for cryoablation only versus radiofrequency ablation only). The long-term success rate was 79.1% for cryoablation only, 92.8% for radiofrequency ablation only, and 66.7% for the combination (p=0.01 for cryoablation only versus radiofrequency ablation only), but long-term success varied notably by provider. Cryoablation and radiofrequency ablation offer similar value in the short term for the treatment of atrioventricular nodal re-entrant tachycardia in children. Differences in long-term success may vary substantially by physician, and thus may lead to differences in long-term value.

Sex differences in associations of arginine vasopressin and oxytocin with resting-state functional brain connectivity.

PubMed

Rubin, Leah H; Yao, Li; Keedy, Sarah K; Reilly, James L; Bishop, Jeffrey R; Carter, C Sue; Pournajafi-Nazarloo, Hossein; Drogos, Lauren L; Tamminga, Carol A; Pearlson, Godfrey D; Keshavan, Matcheri S; Clementz, Brett A; Hill, Scot K; Liao, Wei; Ji, Gong-Jun; Lui, Su; Sweeney, John A

2017-01-02

Oxytocin (OT) and arginine vasopressin (AVP) exert robust and sexually dimorphic influences on cognition and emotion. How these hormones regulate relevant functional brain systems is not well understood. OT and AVP serum concentrations were assayed in 60 healthy individuals (36 women). Brain functional networks assessed with resting-state functional magnetic resonance imaging (rs-fMRI) were constructed with graph theory-based approaches that characterize brain networks as connected nodes. Sex differences were demonstrated in rs-fMRI. Men showed higher nodal degree (connectedness) and efficiency (information propagation capacity) in left inferior frontal gyrus (IFG) and bilateral superior temporal gyrus (STG) and higher nodal degree in left rolandic operculum. Women showed higher nodal betweenness (being part of paths between nodes) in right putamen and left inferior parietal gyrus (IPG). Higher hormone levels were associated with less intrinsic connectivity. In men, higher AVP was associated with lower nodal degree and efficiency in left IFG (pars orbitalis) and left STG and less efficiency in left IFG (pars triangularis). In women, higher AVP was associated with lower betweenness in left IPG, and higher OT was associated with lower nodal degree in left IFG (pars orbitalis). Hormones differentially correlate with brain networks that are important for emotion processing and cognition in men and women. AVP in men and OT in women may regulate orbital frontal cortex connectivity, which is important in emotion processing. Hormone associations with STG and pars triangularis in men and parietal cortex in women may account for well-established sex differences in verbal and visuospatial abilities, respectively. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Three-dimensional conformal radiation for esophageal squamous cell carcinoma with involved-field irradiation may deliver considerable doses of incidental nodal irradiation.

PubMed

Ji, Kai; Zhao, Lujun; Yang, Chengwen; Meng, Maobin; Wang, Ping

2012-11-27

To quantify the incidental irradiation dose to esophageal lymph node stations when irradiating T1-4N0M0 thoracic esophageal squamous cell carcinoma (ESCC) patients with a dose of 60 Gy/30f. Thirty-nine patients with medically inoperable T1-4N0M0 thoracic ESCC were treated with three-dimensional conformal radiation (3DCRT) with involved-field radiation (IFI). The conformal clinical target volume (CTV) was re-created using a 3-cm margin in the proximal and distal direction beyond the barium esophagogram, endoscopic examination and CT scan defined the gross tumor volume (GTV) and a 0.5-cm margin in the lateral and anteroposterior directions of the CT scan-defined GTV. The PTV encompassed 1-cm proximal and distal margins and 0.5-cm radial margin based on the CTV. Nodal regions were delineated using the Japanese Society for Esophageal Diseases (JSED) guidelines and an EORTC-ROG expert opinion. The equivalent uniform dose (EUD) and other dosimetric parameters were calculated for each nodal station. Nodal regions with a metastasis rate greater than 5% were considered a high-risk lymph node subgroup. Under a 60 Gy dosage, the median D mean and EUD was greater than 40 Gy in most high-risk nodal regions except for regions of 104, 106tb-R in upper-thoracic ESCC and 101, 104-R, 105, 106rec-L, 2, 3&7 in middle-thoracic ESCC and 107, 3&7 in lower-thoracic ESCC. In the regions with an EUD less than 40 Gy, most incidental irradiation doses were significantly associated with esophageal tumor length and location. Lymph node stations near ESCC receive considerable incidental irradiation doses with involved-field irradiation that may contribute to the elimination of subclinical lesions.

Three-dimensional conformal radiation therapy for esophageal squamous cell carcinoma: is elective nodal irradiation necessary?

PubMed

Zhao, Kuai-le; Ma, Jin-bo; Liu, Guang; Wu, Kai-liang; Shi, Xue-hui; Jiang, Guo-liang

2010-02-01

To evaluate the local control, survival, and toxicity associated with three-dimensional conformal radiotherapy (3D-CRT) for squamous cell carcinoma (SCC) of the esophagus, to determine the appropriate target volumes, and to determine whether elective nodal irradiation is necessary in these patients. A prospective study of 3D-CRT was undertaken in patients with esophageal SCC without distant metastases. Patients received 68.4 Gy in 41 fractions over 44 days using late-course accelerated hyperfractionated 3D-CRT. Only the primary tumor and positive lymph nodes were irradiated. Isolated out-of-field regional nodal recurrence was defined as a recurrence in an initially uninvolved regional lymph node. All 53 patients who made up the study population tolerated the irradiation well. No acute or late Grade 4 or 5 toxicity was observed. The median survival time was 30 months (95% confidence interval, 17.7-41.8). The overall survival rate at 1, 2, and 3 years was 77%, 56%, and 41%, respectively. The local control rate at 1, 2, and 3 years was 83%, 74%, and 62%, respectively. Thirty-nine of the 53 patients (74%) showed treatment failure. Seventeen of the 39 (44%) developed an in-field recurrence, 18 (46%) distant metastasis with or without regional failure, and 3 (8%) an isolated out-of-field nodal recurrence only. One patient died of disease in an unknown location. In patients treated with 3D-CRT for esophageal SCC, the omission of elective nodal irradiation was not associated with a significant amount of failure in lymph node regions not included in the planning target volume. Local failure and distant metastases remained the predominant problems. Copyright 2010 Elsevier Inc. All rights reserved.

Simultaneous conduction over the fast and slow pathways during induction of atrioventricular nodal reentrant arrhythmia with a rate of less than 100 bpm and infra-His block after radiofrequency ablation of the slow pathway.

PubMed

Amasyalı, Basri; Köktürk, Bülent; Otomo, Kiyoshi; Köse, Sedat

2011-04-01

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of paroxysmal regular supraventricular tachycardia in adults. It is typically induced with an anterograde block over the fast pathway (FP) and conduction over the slow pathway (SP), with subsequent retrograde conduction over the FP. Rarely, a simultaneous conduction of a premature atrial complex occurs over the FP and SP to induce AVNRT and is called "one for two phenomenon". We present a 46-year-old woman with atrioventricular nodal rhythm with a rate of 95 beats per minute with distinct electrophysiological characteristics showing simultaneous conduction over the FP and SP during induction of tachycardia and an infra-His block after radiofrequency ablation of the SP.

The effect of viscosity on steady transonic flow with a nodal solution topology

NASA Technical Reports Server (NTRS)

Owocki, Stanley P.; Zank, Gary P.

1991-01-01

The effect of viscosity on a steady, transonic flow for which the inviscid limit has a nodal solution topology near the critical point is investigated. For the accelerating case, viscous solutions tend to repel each other, so that a very delicate choice of initial conditions is required to prevent them from diverging. Only the two critical solutions extend to arbitrarily large distances into both the subsonic and supersonic flows. For the decelerating case, the solutions tend to attract, and so an entire two-parameter family of solutions now extends over large distances. The general effect of viscosity on the solution degeneracy of a nodal topology is thus to reduce or limit it for the accelerating case and to enhance it for the decelerating case. The astrophysical implications of these findings are addressed.

Quantum anomalies in nodal line semimetals

NASA Astrophysics Data System (ADS)

Burkov, A. A.

2018-04-01

Topological semimetals are a new class of condensed matter systems with nontrivial electronic structure topology. Their unusual observable properties may often be understood in terms of quantum anomalies. In particular, Weyl and Dirac semimetals, which have point band-touching nodes, are characterized by the chiral anomaly, which leads to the Fermi arc surface states, anomalous Hall effect, negative longitudinal magnetoresistance, and planar Hall effect. In this paper, we explore analogous phenomena in nodal line semimetals. We demonstrate that such semimetals realize a three-dimensional analog of the parity anomaly, which is a known property of two-dimensional Dirac semimetals arising, for example, on the surface of a three-dimensional topological insulator. We relate one of the characteristic properties of nodal line semimetals, namely, the drumhead surface states, to this anomaly, and derive the field theory, which encodes the corresponding anomalous response.

Finite-analytic numerical solution of heat transfer in two-dimensional cavity flow

NASA Technical Reports Server (NTRS)

Chen, C.-J.; Naseri-Neshat, H.; Ho, K.-S.

1981-01-01

Heat transfer in cavity flow is numerically analyzed by a new numerical method called the finite-analytic method. The basic idea of the finite-analytic method is the incorporation of local analytic solutions in the numerical solutions of linear or nonlinear partial differential equations. In the present investigation, the local analytic solutions for temperature, stream function, and vorticity distributions are derived. When the local analytic solution is evaluated at a given nodal point, it gives an algebraic relationship between a nodal value in a subregion and its neighboring nodal points. A system of algebraic equations is solved to provide the numerical solution of the problem. The finite-analytic method is used to solve heat transfer in the cavity flow at high Reynolds number (1000) for Prandtl numbers of 0.1, 1, and 10.

Electrode-electrolyte interface model of tripolar concentric ring electrode and electrode paste.

PubMed

Nasrollaholhosseini, Seyed Hadi; Steele, Preston; Besio, Walter G

2016-08-01

Electrodes are used to transform ionic currents to electrical currents in biological systems. Modeling the electrode-electrolyte interface could help to optimize the performance of the electrode interface to achieve higher signal to noise ratios. There are previous reports of accurate models for single-element biomedical electrodes. In this paper we develop a model for the electrode-electrolyte interface for tripolar concentric ring electrodes (TCRE) that are used to record brain signals.

Systems and methods for commutating inductor current using a matrix converter

DOEpatents

Ransom, Ray M; Kajouke, Lateef A; Perisic, Milun

2012-10-16

Systems and methods are provided for delivering current using a matrix converter in a vehicle. An electrical system comprises an AC interface, a first conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the first conversion module, and a control module coupled to the first conversion module. The control module is configured to operate the first conversion module in a bidirectional operating mode to commutate current bidirectionally. When a magnitude of the current through the inductive element is greater than a first threshold value, the control module operates the conversion module in a unidirectional operating mode, wherein current is commutated unidirectionally.

HCN4 ion channel function is required for early events that regulate anatomical left-right patterning in a nodal and lefty asymmetric gene expression-independent manner

PubMed Central

Pai, Vaibhav P.; Willocq, Valerie; Pitcairn, Emily J.; Lemire, Joan M.; Paré, Jean-François; Shi, Nian-Qing; McLaughlin, Kelly A.

2017-01-01

ABSTRACT Laterality is a basic characteristic of all life forms, from single cell organisms to complex plants and animals. For many metazoans, consistent left-right asymmetric patterning is essential for the correct anatomy of internal organs, such as the heart, gut, and brain; disruption of left-right asymmetry patterning leads to an important class of birth defects in human patients. Laterality functions across multiple scales, where early embryonic, subcellular and chiral cytoskeletal events are coupled with asymmetric amplification mechanisms and gene regulatory networks leading to asymmetric physical forces that ultimately result in distinct left and right anatomical organ patterning. Recent studies have suggested the existence of multiple parallel pathways regulating organ asymmetry. Here, we show that an isoform of the hyperpolarization-activated cyclic nucleotide-gated (HCN) family of ion channels (hyperpolarization-activated cyclic nucleotide-gated channel 4, HCN4) is important for correct left-right patterning. HCN4 channels are present very early in Xenopus embryos. Blocking HCN channels (Ih currents) with pharmacological inhibitors leads to errors in organ situs. This effect is only seen when HCN4 channels are blocked early (pre-stage 10) and not by a later block (post-stage 10). Injections of HCN4-DN (dominant-negative) mRNA induce left-right defects only when injected in both blastomeres no later than the 2-cell stage. Analysis of key asymmetric genes' expression showed that the sidedness of Nodal, Lefty, and Pitx2 expression is largely unchanged by HCN4 blockade, despite the randomization of subsequent organ situs, although the area of Pitx2 expression was significantly reduced. Together these data identify a novel, developmental role for HCN4 channels and reveal a new Nodal-Lefty-Pitx2 asymmetric gene expression-independent mechanism upstream of organ positioning during embryonic left-right patterning. PMID:28818840

Clinical Significance of p53 and p16(ink4a) Status in a Contemporary North American Penile Carcinoma Cohort.

PubMed

Zargar-Shoshtari, Kamran; Spiess, Philippe E; Berglund, Anders E; Sharma, Pranav; Powsang, Julio M; Giuliano, Anna; Magliocco, Anthony M; Dhillon, Jasreman

2016-08-01

Because of the low incidence of penile carcinoma (PC), the value of p16(ink4a), p53, and human papilloma virus (HPV) infection status in clinical practice remains unclear. Herein, we report our experience with potential clinical utility of these markers in men with PC treated at our institution. Tissue microarrays of 57 cases of invasive penile squamous cell carcinomas were immunohistochemically stained for p16 and p53. HPV in situ hybridization (ISH) for high-risk subtypes was also performed. Association between marker status, nodal disease, overall (OS) and cancer-specific survival (CSS) were assessed. p16 and HPV ISH were positive in 23 (40%) and 24 (42%) of the cohort, respectively. The proportion of warty, basaloid, or mixed warty basaloid tumor subtypes were significantly greater in the p16-positive patients (48% vs. 3%; P < .01). p53 expression was negative in 31 (54%) cases. Only in p16-negative patients, positive p53 status was associated with pN+ disease (odds ratio, 4.4 [95% confidence interval (CI), 1.04-18.6]). In Kaplan-Meier analysis, the unadjusted estimated OS was insignificantly longer in p16-positive patients (median OS, 75 vs. 27 months; P = .27) and median CSS was not reached (P = .16). In a multivariable Cox proportional hazard model, when controlling for pathological nodal status and adjuvant chemotherapy, p16 status was a significant predictor for improved CSS (hazard ratio, 0.36 [95% CI, 0.13-0.99]). The worst CSS was seen in pN+ patients with double negative p16 and p53 expression (8 vs. 34 months; P = .01). In this current cohort, p53 and p16 status showed clinical utility in predicting nodal disease as well as survival. Copyright © 2015 Elsevier Inc. All rights reserved.

HCN4 ion channel function is required for early events that regulate anatomical left-right patterning in a nodal and lefty asymmetric gene expression-independent manner.

PubMed

Pai, Vaibhav P; Willocq, Valerie; Pitcairn, Emily J; Lemire, Joan M; Paré, Jean-François; Shi, Nian-Qing; McLaughlin, Kelly A; Levin, Michael

2017-10-15

Laterality is a basic characteristic of all life forms, from single cell organisms to complex plants and animals. For many metazoans, consistent left-right asymmetric patterning is essential for the correct anatomy of internal organs, such as the heart, gut, and brain; disruption of left-right asymmetry patterning leads to an important class of birth defects in human patients. Laterality functions across multiple scales, where early embryonic, subcellular and chiral cytoskeletal events are coupled with asymmetric amplification mechanisms and gene regulatory networks leading to asymmetric physical forces that ultimately result in distinct left and right anatomical organ patterning. Recent studies have suggested the existence of multiple parallel pathways regulating organ asymmetry. Here, we show that an isoform of the hyperpolarization-activated cyclic nucleotide-gated (HCN) family of ion channels (hyperpolarization-activated cyclic nucleotide-gated channel 4, HCN4) is important for correct left-right patterning. HCN4 channels are present very early in Xenopus embryos. Blocking HCN channels ( I h currents) with pharmacological inhibitors leads to errors in organ situs. This effect is only seen when HCN4 channels are blocked early (pre-stage 10) and not by a later block (post-stage 10). Injections of HCN4-DN (dominant-negative) mRNA induce left-right defects only when injected in both blastomeres no later than the 2-cell stage. Analysis of key asymmetric genes' expression showed that the sidedness of Nodal , Lefty , and Pitx2 expression is largely unchanged by HCN4 blockade, despite the randomization of subsequent organ situs, although the area of Pitx2 expression was significantly reduced. Together these data identify a novel, developmental role for HCN4 channels and reveal a new Nodal-Lefty-Pitx2 asymmetric gene expression-independent mechanism upstream of organ positioning during embryonic left-right patterning. © 2017. Published by The Company of Biologists Ltd.

Carcinoid tumor of the small intestine: MDCT findings with pathologic correlation.

PubMed

Coulier, B; Pringot, J; Gielen, I; Maldague, P; Broze, B; Ramboux, A; Clausse, M

2007-01-01

MDCT currently frequently represents the first choice modality for imaging in acute or subacute abdominal conditions implicating the small bowel. As a consequence, the MDCT features of intestinal carcinoid tumors and of their peculiar metastatic spread have to be known by abdominal radiologists. These features are described and illustrated in the retrospective review of seven proven cases of small intestine carcinoids diagnosed and treated in our institution. The findings are described and correlated with gross anatomy specimens. The primary tumour clearly appeared as a contrast-enhancing intraluminal lesion in all cases except in one case in which the primary lesion remained unlocalized and in another in which the primary tumour finally appeared infracted at gross anatomy. The maximal tumoral enhancement was obtained in 3 patients imaged during the acute arterial phase. The diameter of the primary tumour ranged from 1 to 3 cm and all masses were ileal comprising one lesion in the proximal ileum, two in the medium ileum and three in the distal ileum. 6/7 patients had multiple prominent mesenteric nodal metastases, all also appearing as hypervascularised enhancing masses. In 4/7 patients the nodal metastases represented the major finding being much prominent and larger than the primary tumour. Signs of retractile mesenteritis with soft tissue stranding, retraction and stellate pattern of the mesentery were found around the mesenteric metastases in 5/7 patients and direct incarceration of vessels were found in 3 cases. The analysis of the arterial phase of MDCT study appears primordial to detect the sometimes very small but intensively enhancing primary tumor and to delineate encasement or direct obstruction of mesenteric vessels frequently caused by enhancing nodal metastases which volume often exceeds that of the primary tumor. Secondary retractile mesenteritis, deformation or ischemia of bowel loops, and hypervascular hepatic metastases are typical associated findings.

Mechanisms defining the electrotonic potential abnormalities in simulated amyotrophic lateral sclerosis.

PubMed

Stephanova, D I; Krustev, S M; Negrev, N

2012-06-01

Electrotonic potentials allow the accommodative processes to polarizing stimuli to be assessed. Electrotonic potential transients in response to applied polarizing stimuli are caused by the kinetics of underlying axonal conductances. Here, we study these transients using our multi-layered model of the human motor nerve, in three simulated cases of the motor neuron disease amyotrophic lateral sclerosis (ALS): ALS1, ALS2 and ALS3 are three consecutively greater degrees of uniform axonal dysfunctions along the human motor nerve fibre. The results show that the responses in the ALS1 case are quite similar to the normal case. In contrast, in the ALS2 and ALS3 cases, long-lasting (100 ms) subthreshold depolarizing stimuli activate the classical "transient" Na(+) channels in the nodal and in the internodal axolemma beneath the myelin sheath; this leads to action potential generation during the early parts of the electrotonic responses in all compartments along the fibre length. The results also show that the electrotonic potentials in response to long-lasting (100 ms) subthreshold hyperpolarizing stimuli in the ALS1 and ALS2 cases are quiet similar to those of the normal case. However, the current kinetics in the ALS3 case differs from the normal case after the termination of the long-lasting hyperpolarizing stimuli. In the most abnormal ALS3 case, the activation of the Na(+) channels in the nodal and in the internodal axolemma leads to repetitive action potential generation in the late parts (100-200 ms) of the hyperpolarizing electrotonic responses. The results show that the repetitive firing, due to the progressively increased nodal and internodal ion channel dysfunction, are consistent with the loss of functional potassium channels involving both the fast and the slow potassium channel types. The results confirm that the electrotonic potentials in the three simulated ALS cases are specific indicators for the motor neuron disease ALS. The mechanisms underlying the simulated ALS are also discussed.

PIERCE1 is critical for specification of left-right asymmetry in mice.

PubMed

Sung, Young Hoon; Baek, In-Jeoung; Kim, Yong Hwan; Gho, Yong Song; Oh, S Paul; Lee, Young Jae; Lee, Han-Woong

2016-06-16

The specification of left-right asymmetry of the visceral organs is precisely regulated. The earliest breakage of left-right symmetry occurs as the result of leftward flow generated by asymmetric beating of nodal cilia, which eventually induces asymmetric Nodal/Lefty/Pitx2 expression on the left side of the lateral plate mesoderm. PIERCE1 has been identified as a p53 target gene involved in the DNA damage response. In this study, we found that Pierce1-null mice exhibit severe laterality defects, including situs inversus totalis and heterotaxy with randomized situs and left and right isomerisms. The spectrum of laterality defects was closely correlated with randomized expression of Nodal and its downstream genes, Lefty1/2 and Pitx2. The phenotype of Pierce1-null mice most closely resembled that of mutant mice with impaired ciliogenesis and/or ciliary motility of the node. We also found the loss of asymmetric expression of Cerl2, the earliest flow-responding gene in the node of Pierce1-null embryos. The results suggest that Pierce1-null embryos have defects in generating a symmetry breaking signal including leftward nodal flow. This is the first report implicating a role for PIERCE1 in the symmetry-breaking step of left-right asymmetry specification.

Embryonic chirality and the evolution of spiralian left–right asymmetries

PubMed Central

2016-01-01

The group Spiralia includes species with one of the most significant cases of left–right asymmetries in animals: the coiling of the shell of gastropod molluscs (snails). In this animal group, an early event of embryonic chirality controlled by cytoskeleton dynamics and the subsequent differential activation of the genes nodal and Pitx determine the left–right axis of snails, and thus the direction of coiling of the shell. Despite progressive advances in our understanding of left–right axis specification in molluscs, little is known about left–right development in other spiralian taxa. Here, we identify and characterize the expression of nodal and Pitx orthologues in three different spiralian animals—the brachiopod Novocrania anomala, the annelid Owenia fusiformis and the nemertean Lineus ruber—and demonstrate embryonic chirality in the biradial-cleaving spiralian embryo of the bryozoan Membranipora membranacea. We show asymmetric expression of nodal and Pitx in the brachiopod and annelid, respectively, and symmetric expression of Pitx in the nemertean. Our findings indicate that early embryonic chirality is widespread and independent of the cleavage programme in the Spiralia. Additionally, our study illuminates the evolution of nodal and Pitx signalling by demonstrating embryonic asymmetric expression in lineages without obvious adult left–right asymmetries. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’. PMID:27821523

Activin- and Nodal-related factors control antero-posterior patterning of the zebrafish embryo.

PubMed

Thisse, B; Wright, C V; Thisse, C

2000-01-27

Definition of cell fates along the dorso-ventral axis depends on an antagonistic relationship between ventralizing transforming growth factor-beta superfamily members, the bone morphogenetic proteins and factors secreted from the dorsal organizer, such as Noggin and Chordin. The extracellular binding of the last group to the bone morphogenetic proteins prevents them from activating their receptors, and the relative ventralizer:antagonist ratio is thought to specify different dorso-ventral cell fates. Here, by taking advantage of a non-genetic interference method using a specific competitive inhibitor, the Lefty-related gene product Antivin, we provide evidence that cell fate along the antero-posterior axis of the zebrafish embryo is controlled by the morphogenetic activity of another transforming growth factor-beta superfamily subgroup--the Activin and Nodal-related factors. Increasing antivin doses progressively deleted posterior fates within the ectoderm, eventually resulting in the removal of all fates except forebrain and eyes. In contrast, overexpression of activin or nodal-related factors converted ectoderm that was fated to be forebrain into more posterior ectodermal or mesendodermal fates. We propose that modulation of intercellular signalling by Antivin/Activin and Nodal-related factors provides a mechanism for the graded establishment of cell fates along the antero-posterior axis of the zebrafish embryo.

Electrodynamics of the nodal metal state in weakly doped high- Tc cuprates

NASA Astrophysics Data System (ADS)

Lee, Y. S.; Segawa, Kouji; Li, Z. Q.; Padilla, W. J.; Dumm, M.; Dordevic, S. V.; Homes, C. C.; Ando, Yoichi; Basov, D. N.

2005-08-01

We report on the detailed analysis of the infrared (IR) conductivity of two prototypical high- Tc systems YBa2Cu3Oy and La2-xSrxCuO4 throughout the complex phase diagram of these compounds. Our focus in this work is to thoroughly document the electromagnetic response of the nodal metal state which is initiated with only a few holes doped in parent antiferromagnetic systems and extends up to the pseudogap boundary in the phase diagram. The key signature of the nodal metal is the two-component conductivity: the Drude mode at low energies followed by a resonance in mid-IR. The Drude component can be attributed to the response of coherent quasiparticles residing on the Fermi arcs detected in photoemission experiments. The microscopic origin of the mid-IR band is yet to be understood. A combination of transport and IR data uncovers fingerprints of the Fermi liquid behavior in the response of the nodal metal. The comprehensive nature of the data sets presented in this work allows us to critically re-evaluate common approaches to the interpretation of the optical data. Specifically we re-examine the role of magnetic excitations in generating electronic self-energy effects through the analysis of the IR data in a high magnetic field.

Room-temperature magnetic topological Weyl fermion and nodal line semimetal states in half-metallic Heusler Co 2TiX (X=Si, Ge, or Sn)

DOE PAGES

Chang, Guoqing; Xu, Su -Yang; Zheng, Hao; ...

2016-12-15

Topological semimetals (TSMs) including Weyl semimetals and nodal-line semimetals are expected to open the next frontier of condensed matter and materials science. Although the first inversion breaking Weyl semimetal was recently discovered in TaAs, its magnetic counterparts, i.e., the time-reversal breaking Weyl and nodal line semimetals, remain elusive. They are predicted to exhibit exotic properties distinct from the inversion breaking TSMs including TaAs. In this paper, we identify the magnetic topological semimetal states in the ferromagnetic half-metal compounds Co 2TiX (X = Si, Ge, or Sn) with Curie temperatures higher than 350 K. Our first-principles band structure calculations show that,more » in the absence of spin-orbit coupling, Co 2TiX features three topological nodal lines. The inclusion of spin-orbit coupling gives rise to Weyl nodes, whose momentum space locations can be controlled as a function of the magnetization direction. Lastly, our results not only open the door for the experimental realization of topological semimetal states in magnetic materials at room temperature, but also suggest potential applications such as unusual anomalous Hall effect in engineered monolayers of the Co 2TiX compounds at high temperature.« less

The Likely Sites of Nodal Metastasis Differs According to the Tumor Extent in Distal Bile Duct Cancer.

PubMed

Kato, Yuichiro; Takahashi, Shinichiro; Gotohda, Naoto; Konishi, Masaru

2016-09-01

In the revised Japanese and Worldwide TNM classification of distal bile duct cancer, the lymph node status is defined as N0 or N1 without reference to the tumor location or extent, according to the presence/absence of metastasis to the regional lymph nodes. Data of 94 patients with distal bile duct cancer who had undergone pancreaticoduodenectomy were reviewed retrospectively. In formalin-fixed specimens, we measured the longitudinal lengths from the papilla to the lower and upper margins of the tumor, in order to investigate the correlation of the tumor extent with the likely sites of nodal metastasis. The frequencies of metastasis to the posterior pancreaticoduodenal nodes (7.1 %) and superior mesenteric artery nodes (0.0 %) were significantly lower in the cases in which the length from the papilla to the lower margin of the tumor was ≥30 mm. The frequencies of nodal metastasis to the common hepatic artery nodes (0.0 %) and hepatoduodenal ligament nodes (6.7 %) were significantly lower in the cases in which the length from the papilla to the upper margin was <40 mm. The likely sites of nodal metastasis differ according to the extent of the tumor in cases of bile duct cancer.

A nodal domain theorem for integrable billiards in two dimensions

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

Samajdar, Rhine; Jain, Sudhir R., E-mail: srjain@barc.gov.in

Eigenfunctions of integrable planar billiards are studied — in particular, the number of nodal domains, ν of the eigenfunctions with Dirichlet boundary conditions are considered. The billiards for which the time-independent Schrödinger equation (Helmholtz equation) is separable admit trivial expressions for the number of domains. Here, we discover that for all separable and non-separable integrable billiards, ν satisfies certain difference equations. This has been possible because the eigenfunctions can be classified in families labelled by the same value of mmodkn, given a particular k, for a set of quantum numbers, m,n. Further, we observe that the patterns in a familymore » are similar and the algebraic representation of the geometrical nodal patterns is found. Instances of this representation are explained in detail to understand the beauty of the patterns. This paper therefore presents a mathematical connection between integrable systems and difference equations. - Highlights: • We find that the number of nodal domains of eigenfunctions of integrable, planar billiards satisfy a class of difference equations. • The eigenfunctions labelled by quantum numbers (m,n) can be classified in terms of mmodkn. • A theorem is presented, realising algebraic representations of geometrical patterns exhibited by the domains. • This work presents a connection between integrable systems and difference equations.« less

Room-temperature magnetic topological Weyl fermion and nodal line semimetal states in half-metallic Heusler Co 2TiX (X=Si, Ge, or Sn)

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

Chang, Guoqing; Xu, Su -Yang; Zheng, Hao

Topological semimetals (TSMs) including Weyl semimetals and nodal-line semimetals are expected to open the next frontier of condensed matter and materials science. Although the first inversion breaking Weyl semimetal was recently discovered in TaAs, its magnetic counterparts, i.e., the time-reversal breaking Weyl and nodal line semimetals, remain elusive. They are predicted to exhibit exotic properties distinct from the inversion breaking TSMs including TaAs. In this paper, we identify the magnetic topological semimetal states in the ferromagnetic half-metal compounds Co 2TiX (X = Si, Ge, or Sn) with Curie temperatures higher than 350 K. Our first-principles band structure calculations show that,more » in the absence of spin-orbit coupling, Co 2TiX features three topological nodal lines. The inclusion of spin-orbit coupling gives rise to Weyl nodes, whose momentum space locations can be controlled as a function of the magnetization direction. Lastly, our results not only open the door for the experimental realization of topological semimetal states in magnetic materials at room temperature, but also suggest potential applications such as unusual anomalous Hall effect in engineered monolayers of the Co 2TiX compounds at high temperature.« less

A Poised Chromatin Platform for TGF-[beta] Access to Master Regulators

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

Xi, Qiaoran; Wang, Zhanxin; Zaromytidou, Alexia-Ileana

2012-02-07

Specific chromatin marks keep master regulators of differentiation silent yet poised for activation by extracellular signals. We report that nodal TGF-{beta} signals use the poised histone mark H3K9me3 to trigger differentiation of mammalian embryonic stem cells. Nodal receptors induce the formation of companion Smad4-Smad2/3 and TRIM33-Smad2/3 complexes. The PHD-Bromo cassette of TRIM33 facilitates binding of TRIM33-Smad2/3 to H3K9me3 and H3K18ac on the promoters of mesendoderm regulators Gsc and Mixl1. The crystal structure of this cassette, bound to histone H3 peptides, illustrates that PHD recognizes K9me3, and Bromo binds an adjacent K18ac. The interaction between TRIM33-Smad2/3 and H3K9me3 displaces the chromatin-compactingmore » factor HP1, making nodal response elements accessible to Smad4-Smad2/3 for Pol II recruitment. In turn, Smad4 increases K18 acetylation to augment TRIM33-Smad2/3 binding. Thus, nodal effectors use the H3K9me3 mark as a platform to switch master regulators of stem cell differentiation from the poised to the active state.« less

Atlas of the thoracic lymph nodal delineation and recommendations for lymph nodal CTV of esophageal squamous cell cancer in radiation therapy from China.

PubMed

Huang, Wei; Huang, Yong; Sun, Jujie; Liu, Xibin; Zhang, Jian; Zhou, Tao; Zhang, Baijiang; Li, Baosheng

2015-07-01

To construct an anatomical atlas of thoracic lymph node regions of esophageal cancer (EC) based on definitions from The Japan Esophageal Society (JES) and generate a consensus to delineate the nodal clinical target volume (CTVn) for elective nodal radiation (ENI) of esophageal squamous cell carcinoma (ESCC). An interdisciplinary group including two dedicated radiation oncologists, an experienced radiologist, a pathologist and two thoracic surgeons were gathered to generate a three-dimensional radiological description for the mediastinal lymph node regions of EC on axial CT scans. Then the radiological boundaries of lymph node regions were validated by a relatively large number of physicians in multiple institutions. An atlas of detailed anatomic boundaries of lymph node station No. 105-114 was defined on axial CT, along with illustrations. From the previous work, the study provided a guide of CTVn contouring for ENI of thoracic ESCC from a single center. It is feasible to use such an atlas of thoracic lymph node stations for radiotherapy planning. A phase III study based on the atlas is ongoing in China to measure quantitatively the ENI received by patients with ESCC. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Quantum oscillation signatures of spin-orbit interactions controlling the residual nodal bilayer-splitting in underdoped high-Tc cuprates

NASA Astrophysics Data System (ADS)

Harrison, Neil; Shekhter, Arkady

2015-03-01

We investigate the origin of the small residual nodal bilayer-splitting in the underdoped high-Tc superconductor YBa2Cu3O6+x using the results of recently published angle-resolved quantum oscillation data [Sebastian et al., Nature 511, 61 (2014)]. A crucial clue to the origin of the residual bilayer-splitting is found to be provided by the anomalously small Zeeman-splitting of some of the observed cyclotron orbits. We show that such an anomalously Zeeman-splitting (or small effective g-factor) for a subset of orbits can be explained by spin-orbit interactions, which become significant in the nodal regions as a result of the vanishing bilayer coupling. The primary effect of spin-orbit interactions is to cause quasiparticles traversing the nodal region of the Brillouin zone to undergo a spin flip. We suggest that the Rashba-like spin-orbit interactions, naturally present in bilayer systems, have the right symmetry and magnitude to give rise to a network of coupled orbits consistent with experimental observations in underdoped YBa2Cu3O6+x. This work is supported by the DOEm BES proposal LANLF100, while the magnet lab is supported by the NSF and Florida State.

Interface demarcation in GaAs by current pulsing

NASA Technical Reports Server (NTRS)

Matthiesen, D. H.; Kafalas, J. A.; Duchene, G. A.; Bellows, A. H.

1990-01-01

GTE Laboratories is currently conducting a program to investigate the effect of convection in the melt on the properties of bulk grown gallium arsenide (GaAs). In addition to extensive ground based experimentation, a Get Away Special growth system has been developed to grow two GaAs crystals aboard the Space Shuttle, each with a one inch diameter. In order to perform a complete segregation analysis of the crystals grown in space, it is necessary to measure the interface shape and growth rate as well as the spatial distribution of the selenium dopant. The techniques for interface demarcation in selenium doped GaAs by current pulsing have been developed at GTE Laboratories and successful interface demarcation has been achieved for current pulses ranging from 20 to 90 amps, in both single crystal and polycrystalline regions.

Primary Ovarian Large B-Cell Lymphoma

PubMed Central

Islimye Taskın, Mine; Gokgozoglu, Levent; Kandemır, Bedrı

2013-01-01

The involvement of the ovary by malignant lymphoma is a well-known late manifestation of disseminated nodal disease. Primary ovarian lymphoma is rare. We herein describe a case of primary ovarian diffuse large B-cell lymphoma involving unilateral ovary in a 38-year-old woman which was detected incidentally. Preoperative ultrasonic imaging showed a 46∗42 mm heterogeneous cystic mass. Laparotomy revealed that left adnexal mass and left salpingo-oophorectomy was performed. The current diagnosis was determined after immunostaining. The patient was treated with R-CHOP regimen after the operation. She remains cancer-free 24 months after chemotherapy. PMID:24222873

Atrial remodelling in atrial fibrillation: CaMKII as a nodal proarrhythmic signal

PubMed Central

Mesubi, Olurotimi O.; Anderson, Mark E.

2016-01-01

CaMKII is a serine–threonine protein kinase that is abundant in myocardium. Emergent evidence suggests that CaMKII may play an important role in promoting atrial fibrillation (AF) by targeting a diverse array of proteins involved in membrane excitability, cell survival, calcium homeostasis, matrix remodelling, inflammation, and metabolism. Furthermore, CaMKII inhibition appears to protect against AF in animal models and correct proarrhythmic, defective intracellular Ca2+ homeostasis in fibrillating human atrial cells. This review considers current concepts and evidence from animal and human studies on the role of CaMKII in AF. PMID:26762270

Conduction mechanism change with transport oxide layer thickness in oxide hetero-interface diode

NASA Astrophysics Data System (ADS)

Nam, Bu-il; Park, Jong Seo; Lim, Keon-Hee; Ahn, Yong-keon; Lee, Jinwon; Park, Jun-woo; Cho, Nam-Kwang; Lee, Donggun; Lee, Han-Bo-Ram; Kim, Youn Sang

2017-07-01

An effective and facile strategy is proposed to demonstrate an engineered oxide hetero-interface of a thin film diode with a high current density and low operating voltage. The electrical characteristics of an oxide hetero-interface thin film diode are governed by two theoretical models: the space charge-limited current model and the Fowler-Nordheim (F-N) tunneling model. Interestingly, the dominant mechanism strongly depends on the insulator thickness, and the mechanism change occurs at a critical thickness. This paper shows that conduction mechanisms of oxide hetero-interface thin film diodes depend on thicknesses of transport oxide layers and that current densities of these can be exponentially increased through quantum tunneling in the diodes with the thicknesses less than 10 nm. These oxide hetero-interface diodes have great potential for low-powered transparent nanoscale applications.

Development and Evaluation of a Hydrostatic Dynamical Core Using the Spectral Element/Discontinuous Galerkin Methods

DTIC Science & Technology

2014-04-01

The CG and DG horizontal discretization employs high-order nodal basis functions associated with Lagrange polynomials based on Gauss-Lobatto- Legendre ...and DG horizontal discretization employs high-order nodal basis functions 29 associated with Lagrange polynomials based on Gauss-Lobatto- Legendre ...Inside 235 each element we build ( 1)N + Gauss-Lobatto- Legendre (GLL) quadrature points, where N 236 indicate the polynomial order of the basis

Brady's Geothermal Field Nodal Seismometer Active Source Data Sample

DOE Data Explorer

Kurt Feigl

2016-03-25

This data is in sac format and includes recordings of two active source events from 238 three-component nodal seismometers deployed at Bradys Hot Springs geothermal field as part of the PoroTomo project. The source was a viberoseis truck operating in P-wave vibrational mode and generating a swept-frequency signal. The files are 33 seconds long starting 4 seconds before each sweep was initiated. There is some overlap in the file times.

Role of the EGF-Related Growth Factor Cripto in Murine Mammary Tumorigenesis

DTIC Science & Technology

1999-10-01

release or disclosure of technical data (other than detailed manufacturing or process data) to, or use of such data by, a foreign government that is in...function, we have made constructs that express secreted processed NODAL protein in transfected mammalian cells. For this purpose, we have used a wild-type...that processing of unmodified NODAL protein is dependent upon the cell line used for expression, which presumably reflects differential expression of

Distinct mechanisms determine organ left-right asymmetry patterning in an uncoupled way.

PubMed

Huang, Sizhou; Xu, Wenming; Su, Bingyin; Luo, Lingfei

2014-03-01

Disruption of Nodal in the lateral plate mesoderm (LPM) usually leads to left-right (LR) patterning defects in multiple organs. However, whether the LR patterning of organs is always regulated in a coupled way has largely not yet been elucidated. In addition, whether other crucial regulators exist in the LPM that coordinate with Nodal in regulating organ LR patterning is also undetermined. In this paper, after briefly summarizing the common process of LR patterning, the most puzzling question regarding the initiation of asymmetry is considered and the divergent mechanisms underlying the uncoupled LR patterning in different organs are discussed. On the basis of cases in which different organ LR patterning is determined in an uncoupled way via an independent mechanism or at a different time, we propose that there are other critical factors in the LPM that coordinate with Nodal to regulate heart LR asymmetry patterning during early LR patterning. © 2014 WILEY Periodicals, Inc.

Scanning Tunneling Microscopy Study on Dirac Nodal-line Semimetal ZrSiS

NASA Astrophysics Data System (ADS)

Su, Chih-Chuan; Guan, Syu-You; Wang, Tzu-Cheng; Sankar, Raman; Guo, Guang-Yu; Chou, Fangcheng; Chang, Chia-Seng; Chuang, Tien-Ming

The discovery of 3D Dirac nodal-line protected by non-symmophic symmetry in ZrSiS family has been reported by angle resolved photoemission spectroscopy (ARPES) and quantum oscillation measurements. ZrSiS also exhibits a butterfly shaped titanic angular magnetoresistance and strong Zeeman splitting in quantum oscillation. These observations with its layered crystal structure make the ZrSiS family an interesting candidate to understand the novel properties of the nodal-line semimetals. Here, we study the electronic structures of the single crystal ZrSiS by using spectroscopic-imaging scanning tunneling microscope at T= 4.2K. Our quasiparticle scattering interference imaging reveals the characteristic wave vectors with linear dispersion from Dirac line nodes in the bulk and its surface states. Our results are in excellent agreement with the first principle calculation, and also in consistent with ARPES and quantum oscillation measurements.

Incidence of cervical lymph node metastasis and its association with outcomes in patients with adenoid cystic carcinoma. An international collaborative study

PubMed Central

Amit, Moran; Binenbaum, Yoav; Sharma, Kanika; Ramer, Naomi; Ramer, Ilana; Agbetoba, Abib; Glick, Joelle; Yang, Xinjie; Lei, Delin; Bjørndal, Kristine; Godballe, Christian; Mücke, Thomas; Wolff, Klaus-Dietrich; Fliss, Dan; Eckardt, André M.; Copelli, Chiara; Sesenna, Enrico; Palmer, Frank; Ganly, Ian; Patel, Snehal; Gil, Ziv

2016-01-01

Background The patterns of regional metastasis in adenoid cystic carcinoma (ACC) of the head and neck and its association with outcome is not established. Methods We conducted a retrospective multicentered multivariate analysis of 270 patients who underwent neck dissection. Results The incidence rate of neck metastases was 29%. The rate observed in the oral cavity is 37%, and in the major salivary glands is 19% (p = .001). The rate of occult nodal metastases was 17%. Overall 5-year survival rates were 44% in patients undergoing therapeutic neck dissections, and 65% and 73% among those undergoing elective neck dissections, with and without nodal metastases, respectively (p = .017). Multivariate analysis revealed that the primary site, nodal classification, and margin status were independent predictors of survival. Conclusion Our findings support the consideration of elective neck treatment in patients with ACC of the oral cavity. PMID:25060927

Pelvic Nodal Radiotherapy in Patients With Unfavorable Intermediate and High-Risk Prostate Cancer: Evidence, Rationale, and Future Directions

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

Morikawa, Lisa K.; Memorial Sloan-Kettering Cancer Center; Roach, Mack, E-mail: mroach@radonc.ucsf.ed

2011-05-01

Over the past 15 years, there have been three major advances in the use of external beam radiotherapy in the management of men with clinically localized prostate made. They include: (1) image guided (IG) three-dimensional conformal/intensity modulated radiotherapy; (2) radiation dose escalation; and (3) androgen deprivation therapy. To date only the last of these three advances have been shown to improve overall survival. The presence of occult pelvic nodal involvement could explain the failure of increased conformality and dose escalation to prolong survival, because the men who appear to be at the greatest risk of death from clinically localized prostatemore » cancer are those who are likely to have lymph node metastases. This review discusses the evidence for prophylactic pelvic nodal radiotherapy, including the key trials and controversies surrounding this issue.« less

Nodal failure index approach to groundwater remediation design

USGS Publications Warehouse

Lee, J.; Reeves, H.W.; Dowding, C.H.

2008-01-01

Computer simulations often are used to design and to optimize groundwater remediation systems. We present a new computationally efficient approach that calculates the reliability of remedial design at every location in a model domain with a single simulation. The estimated reliability and other model information are used to select a best remedial option for given site conditions, conceptual model, and available data. To evaluate design performance, we introduce the nodal failure index (NFI) to determine the number of nodal locations at which the probability of success is below the design requirement. The strength of the NFI approach is that selected areas of interest can be specified for analysis and the best remedial design determined for this target region. An example application of the NFI approach using a hypothetical model shows how the spatial distribution of reliability can be used for a decision support system in groundwater remediation design. ?? 2008 ASCE.

From nodal-ring topological superfluids to spiral Majorana modes in cold atomic systems

NASA Astrophysics Data System (ADS)

He, Wen-Yu; Xu, Dong-Hui; Zhou, Benjamin T.; Zhou, Qi; Law, K. T.

2018-04-01

In this work, we consider a three-dimensional (3D) cubic optical lattice composed of coupled 1D wires with 1D spin-orbit coupling. When the s -wave pairing is induced through Feshbach resonance, the system becomes a topological superfluid with ring nodes, which are the ring nodal degeneracies in the bulk, and supports a large number of surface Majorana zero-energy modes. The large number of surface Majorana modes remain at zero energy even in the presence of disorder due to the protection from a chiral symmetry. When the chiral symmetry is broken, the system becomes a Weyl topological superfluid with Majorana arcs. With 3D spin-orbit coupling, the Weyl superfluid becomes a gapless phase with spiral Majorana modes on the surface. A spatial-resolved radio-frequency spectroscopy is suggested to detect this nodal-ring topological superfluid phase.

Neuroendocrine Merkel cell nodal carcinoma of unknown primary site: management and outcomes of a rare entity.

PubMed

Kotteas, E A; Pavlidis, N

2015-04-01

Merkel cell nodal carcinoma of unknown primary (MCCUP) is a rare neuroendocrine tumour with distinct clinical and biological behaviour. We conducted a review of retrospective data extracted from 90 patients focusing on the management and outcome of this disease. We also compared life expectancy of these patients with the outcome of patients with known Merkel primaries and with neuroendocrine cancers of unidentifiable primary. There is a limited body of data for this type of malignancy, however, patients with Merkel cell nodal carcinoma of unknown primary site, seem to have better survival when treated aggressively than patients with cutaneous Merkel tumours of the same stage and equal survival with patients with low-grade neuroendocrine tumour of unknown origin. The lack of prospective trials, and the inadequate data, hamper the management of these tumours. Establishment of treatment guidelines is urgently needed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Characterization of Lifshitz transitions in topological nodal line semimetals

NASA Astrophysics Data System (ADS)

Jiang, Hui; Li, Linhu; Gong, Jiangbin; Chen, Shu

2018-04-01

We introduce a two-band model of three-dimensional nodal line semimetals (NLSMs), the Fermi surface of which at half-filling may form various one-dimensional configurations of different topology. We study the symmetries and "drumhead" surface states of the model, and find that the transitions between different configurations, namely, the Lifshitz transitions, can be identified solely by the number of gap-closing points on some high-symmetry planes in the Brillouin zone. A global phase diagram of this model is also obtained accordingly. We then investigate the effect of some extra terms analogous to a two-dimensional Rashba-type spin-orbit coupling. The introduced extra terms open a gap for the NLSMs and can be useful in engineering different topological insulating phases. We demonstrate that the behavior of surface Dirac cones in the resulting insulating system has a clear correspondence with the different configurations of the original nodal lines in the absence of the gap terms.

Controlling the motion of multiple objects on a Chladni plate

NASA Astrophysics Data System (ADS)

Zhou, Quan; Sariola, Veikko; Latifi, Kourosh; Liimatainen, Ville

2016-09-01

The origin of the idea of moving objects by acoustic vibration can be traced back to 1787, when Ernst Chladni reported the first detailed studies on the aggregation of sand onto nodal lines of a vibrating plate. Since then and to this date, the prevailing view has been that the particle motion out of nodal lines is random, implying uncontrollability. But how random really is the out-of-nodal-lines motion on a Chladni plate? Here we show that the motion is sufficiently regular to be statistically modelled, predicted and controlled. By playing carefully selected musical notes, we can control the position of multiple objects simultaneously and independently using a single acoustic actuator. Our method allows independent trajectory following, pattern transformation and sorting of multiple miniature objects in a wide range of materials, including electronic components, water droplets loaded on solid carriers, plant seeds, candy balls and metal parts.

Nodal-line pairing with 1D-3D coupled Fermi surfaces: A model motivated by Cr-based superconductors

NASA Astrophysics Data System (ADS)

Wachtel, Gideon; Kim, Yong Baek

2016-09-01

Motivated by the recent discovery of a new family of chromium-based superconductors, we consider a two-band model, where a band of electrons dispersing only in one direction interacts with a band of electrons dispersing in all three directions. Strong 2 kf density fluctuations in the one-dimensional band induces attractive interactions between the three-dimensional electrons, which, in turn, makes the system superconducting. Solving the associated Eliashberg equations, we obtain a gap function which is peaked at the "poles" of the three-dimensional Fermi sphere, and decreases towards the "equator." When strong enough local repulsion is included, the gap actually changes sign around the equator and nodal rings are formed. These nodal rings manifest themselves in several experimentally observable quantities, some of which resemble unconventional observations in the newly discovered superconductors which motivated this work.

Programming and Isolation of Highly Pure Physiologically and Pharmacologically Functional Sinus-Nodal Bodies from Pluripotent Stem Cells

PubMed Central

Jung, Julia Jeannine; Husse, Britta; Rimmbach, Christian; Krebs, Stefan; Stieber, Juliane; Steinhoff, Gustav; Dendorfer, Andreas; Franz, Wolfgang-Michael; David, Robert

2014-01-01

Summary Therapeutic approaches for “sick sinus syndrome” rely on electrical pacemakers, which lack hormone responsiveness and bear hazards such as infection and battery failure. These issues may be overcome via “biological pacemakers” derived from pluripotent stem cells (PSCs). Here, we show that forward programming of PSCs with the nodal cell inducer TBX3 plus an additional Myh6-promoter-based antibiotic selection leads to cardiomyocyte aggregates consisting of >80% physiologically and pharmacologically functional pacemaker cells. These induced sinoatrial bodies (iSABs) exhibited highly increased beating rates (300–400 bpm), coming close to those found in mouse hearts, and were able to robustly pace myocardium ex vivo. Our study introduces iSABs as highly pure, functional nodal tissue that is derived from PSCs and may be important for future cell therapies and drug testing in vitro. PMID:24936448

Connections that Count: Brain-Computer Interface Enables the Profoundly Paralyzed to Communicate

MedlinePlus

... Home Current Issue Past Issues Connections that Count: Brain-Computer Interface Enables the Profoundly Paralyzed to Communicate ... of this page please turn Javascript on. A brain-computer interface (BCI) system This brain-computer interface ( ...

A phase II comparative study of gross tumor volume definition with or without PET/CT fusion in dosimetric planning for non-small-cell lung cancer (NSCLC): primary analysis of Radiation Therapy Oncology Group (RTOG) 0515.

PubMed

Bradley, Jeffrey; Bae, Kyounghwa; Choi, Noah; Forster, Ken; Siegel, Barry A; Brunetti, Jacqueline; Purdy, James; Faria, Sergio; Vu, Toni; Thorstad, Wade; Choy, Hak

2012-01-01

Radiation Therapy Oncology Group (RTOG) 0515 is a Phase II prospective trial designed to quantify the impact of positron emission tomography (PET)/computed tomography (CT) compared with CT alone on radiation treatment plans (RTPs) and to determine the rate of elective nodal failure for PET/CT-derived volumes. Each enrolled patient underwent definitive radiation therapy for non-small-cell lung cancer (≥ 60 Gy) and had two RTP datasets generated: gross tumor volume (GTV) derived with CT alone and with PET/CT. Patients received treatment using the PET/CT-derived plan. The primary end point, the impact of PET/CT fusion on treatment plans was measured by differences of the following variables for each patient: GTV, number of involved nodes, nodal station, mean lung dose (MLD), volume of lung exceeding 20 Gy (V20), and mean esophageal dose (MED). Regional failure rate was a secondary end point. The nonparametric Wilcoxon matched-pairs signed-ranks test was used with Bonferroni adjustment for an overall significance level of 0.05. RTOG 0515 accrued 52 patients, 47 of whom are evaluable. The follow-up time for all patients is 12.9 months (2.7-22.2). Tumor staging was as follows: II = 6%; IIIA = 40%; and IIIB = 54%. The GTV was statistically significantly smaller for PET/CT-derived volumes (98.7 vs. 86.2 mL; p < 0.0001). MLDs for PET/CT plans were slightly lower (19 vs. 17.8 Gy; p = 0.06). There was no significant difference in the number of involved nodes (2.1 vs. 2.4), V20 (32% vs. 30.8%), or MED (28.7 vs. 27.1 Gy). Nodal contours were altered by PET/CT for 51% of patients. One patient (2%) has developed an elective nodal failure. PET/CT-derived tumor volumes were smaller than those derived by CT alone. PET/CT changed nodal GTV contours in 51% of patients. The elective nodal failure rate for GTVs derived by PET/CT is quite low, supporting the RTOG standard of limiting the target volume to the primary tumor and involved nodes. Copyright © 2012 Elsevier Inc. All rights reserved.

An institutional approach to support the conduct and use of health policy and systems research: The Nodal Institute in the Eastern Mediterranean Region.

PubMed

El-Jardali, Fadi; Saleh, Shadi; Khodor, Rawya; Abu Al Rub, Raeda; Arfa, Chokri; Ben Romdhane, Habiba; Hamadeh, Randah R

2015-10-01

The use of health policy and systems research (HPSR) to support decision making in health systems is limited in the Eastern Mediterranean Region (EMR). This is partly due to the lack of effective initiatives to strengthen regional HPSR capacities and promote its use in decision making. This paper offers a structured reflection on the establishment and core functioning of a HPSR Nodal Institute for the EMR with specific focus on the approach used to support the conduct and use of HPSR. It seeks to gain better understanding of the activities conducted by the Nodal Institute, the methods by which the Nodal Institute implemented these activities, and the outcomes of these activities. A multi-faceted approach was implemented by the Nodal Institute in collaboration with regional academic/research institutions, Sub-Nodes. The overall approach was a phased one that included the selection of Sub-Nodes, mapping of academic/research institutions in the EMR, stakeholders' meetings, and HPSR capacity building workshops, and culminated with a regional meeting. The mapping of academic/research institutions in the EMR resulted in the identification of 50 institutions, of which only 32 were engaged in HPSR. These institutions have the highest HPSR involvement in information/evidence (84%) and the lowest in human resources for health (34%). Their main HPSR focus areas included quality of healthcare services, patient safety, management of non-communicable diseases, and human resources for health. Regional HPSR challenges among these institutions were identified. The validation and ranking questionnaires resulted in the identification of country-specific HPSR priorities according to stakeholders in three countries. From these results, cross-cutting HPSR priorities among the countries related to primary healthcare, non-communicable diseases, human resources for health, as well as cross-cutting HPSR priorities among stakeholders and according to stakeholders of the countries, were extracted. The Nodal Institute in the EMR is a promising initiative to support the conduct and use of HPSR in health policies. The approach and findings reported in this paper allow for the development of opportunities towards the building of capacity for HPSR in the region and other countries and provide a roadmap for academic/research institutions interested in HPSR in the region.

Patterns of practice of regional nodal irradiation in breast cancer: results of the European Organization for Research and Treatment of Cancer (EORTC) NOdal Radiotherapy (NORA) survey.

PubMed

Belkacemi, Y; Kaidar-Person, O; Poortmans, P; Ozsahin, M; Valli, M-C; Russell, N; Kunkler, I; Hermans, J; Kuten, A; van Tienhoven, G; Westenberg, H

2015-03-01

Predicting outcome of breast cancer (BC) patients based on sentinel lymph node (SLN) status without axillary lymph node dissection (ALND) is an area of uncertainty. It influences the decision-making for regional nodal irradiation (RNI). The aim of the NORA (NOdal RAdiotherapy) survey was to examine the patterns of RNI. A web-questionnaire, including several clinical scenarios, was distributed to 88 EORTC-affiliated centers. Responses were received between July 2013 and January 2014. A total of 84 responses were analyzed. While three-dimensional (3D) radiotherapy (RT) planning is carried out in 81 (96%) centers, nodal areas are delineated in only 51 (61%) centers. Only 14 (17%) centers routinely link internal mammary chain (IMC) and supraclavicular node (SCN) RT indications. In patients undergoing total mastectomy (TM) with ALND, SCN-RT is recommend by 5 (6%), 53 (63%) and 51 (61%) centers for patients with pN0(i+), pN(mi) and pN1, respectively. Extra-capsular extension (ECE) is the main factor influencing decision-making RNI after breast conserving surgery (BCS) and TM. After primary systemic therapy (PST), 49 (58%) centers take into account nodal fibrotic changes in ypN0 patients for RNI indications. In ypN0 patients with inner/central tumors, 23 (27%) centers indicate SCN-RT and IMC-RT. In ypN1 patients, SCN-RT is delivered by less than half of the centers in patients with ypN(i+) and ypN(mi). Twenty-one (25%) of the centers recommend ALN-RT in patients with ypN(mi) or 1-2N+ after ALND. Seventy-five (90%) centers state that age is not considered a limiting factor for RNI. The NORA survey is unique in evaluating the impact of SLNB/ALND status on adjuvant RNI decision-making and volumes after BCS/TM with or without PST. ALN-RT is often indicated in pN1 patients, particularly in the case of ECE. Besides the ongoing NSABP-B51/RTOG and ALLIANCE trials, NORA could help to design future specific RNI trials in the SLNB era without ALND in patients receiving or not PST. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Off-fault plasticity in three-dimensional dynamic rupture simulations using a modal Discontinuous Galerkin method on unstructured meshes: Implementation, verification, and application

NASA Astrophysics Data System (ADS)

Wollherr, Stephanie; Gabriel, Alice-Agnes; Uphoff, Carsten

2018-05-01

The dynamics and potential size of earthquakes depend crucially on rupture transfers between adjacent fault segments. To accurately describe earthquake source dynamics, numerical models can account for realistic fault geometries and rheologies such as nonlinear inelastic processes off the slip interface. We present implementation, verification, and application of off-fault Drucker-Prager plasticity in the open source software SeisSol (www.seissol.org). SeisSol is based on an arbitrary high-order derivative modal Discontinuous Galerkin (ADER-DG) method using unstructured, tetrahedral meshes specifically suited for complex geometries. Two implementation approaches are detailed, modelling plastic failure either employing sub-elemental quadrature points or switching to nodal basis coefficients. At fine fault discretizations the nodal basis approach is up to 6 times more efficient in terms of computational costs while yielding comparable accuracy. Both methods are verified in community benchmark problems and by three dimensional numerical h- and p-refinement studies with heterogeneous initial stresses. We observe no spectral convergence for on-fault quantities with respect to a given reference solution, but rather discuss a limitation to low-order convergence for heterogeneous 3D dynamic rupture problems. For simulations including plasticity, a high fault resolution may be less crucial than commonly assumed, due to the regularization of peak slip rate and an increase of the minimum cohesive zone width. In large-scale dynamic rupture simulations based on the 1992 Landers earthquake, we observe high rupture complexity including reverse slip, direct branching, and dynamic triggering. The spatio-temporal distribution of rupture transfers are altered distinctively by plastic energy absorption, correlated with locations of geometrical fault complexity. Computational cost increases by 7% when accounting for off-fault plasticity in the demonstrating application. Our results imply that the combination of fully 3D dynamic modelling, complex fault geometries, and off-fault plastic yielding is important to realistically capture dynamic rupture transfers in natural fault systems.

New Multi-group Transport Neutronics (PHISICS) Capabilities for RELAP5-3D and its Application to Phase I of the OECD/NEA MHTGR-350 MW Benchmark

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

Gerhard Strydom; Cristian Rabiti; Andrea Alfonsi

2012-10-01

PHISICS is a neutronics code system currently under development at the Idaho National Laboratory (INL). Its goal is to provide state of the art simulation capability to reactor designers. The different modules for PHISICS currently under development are a nodal and semi-structured transport core solver (INSTANT), a depletion module (MRTAU) and a cross section interpolation (MIXER) module. The INSTANT module is the most developed of the mentioned above. Basic functionalities are ready to use, but the code is still in continuous development to extend its capabilities. This paper reports on the effort of coupling the nodal kinetics code package PHISICSmore » (INSTANT/MRTAU/MIXER) to the thermal hydraulics system code RELAP5-3D, to enable full core and system modeling. This will enable the possibility to model coupled (thermal-hydraulics and neutronics) problems with more options for 3D neutron kinetics, compared to the existing diffusion theory neutron kinetics module in RELAP5-3D (NESTLE). In the second part of the paper, an overview of the OECD/NEA MHTGR-350 MW benchmark is given. This benchmark has been approved by the OECD, and is based on the General Atomics 350 MW Modular High Temperature Gas Reactor (MHTGR) design. The benchmark includes coupled neutronics thermal hydraulics exercises that require more capabilities than RELAP5-3D with NESTLE offers. Therefore, the MHTGR benchmark makes extensive use of the new PHISICS/RELAP5-3D coupling capabilities. The paper presents the preliminary results of the three steady state exercises specified in Phase I of the benchmark using PHISICS/RELAP5-3D.« less

Ballistic-Electron-Emission Microscope

NASA Technical Reports Server (NTRS)

Kaiser, William J.; Bell, L. Douglas

1990-01-01

Ballistic-electron-emission microscope (BEEM) employs scanning tunneling-microscopy (STM) methods for nondestructive, direct electrical investigation of buried interfaces, such as interface between semiconductor and thin metal film. In BEEM, there are at least three electrodes: emitting tip, biasing electrode, and collecting electrode, receiving current crossing interface under investigation. Signal-processing device amplifies electrode signals and converts them into form usable by computer. Produces spatial images of surface by scanning tip; in addition, provides high-resolution images of buried interface under investigation. Spectroscopic information extracted by measuring collecting-electrode current as function of one of interelectrode voltages.

Mathematical Formalism for Designing Wide-Field X-Ray Telescopes: Mirror Nodal Positions and Detector Tilts

NASA Technical Reports Server (NTRS)

Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

2011-01-01

We provide a mathematical formalism for optimizing the mirror nodal positions along the optical axis and the tilt of a commonly employed detector configuration at the focus of a x-ray telescope consisting of nested mirror shells with known mirror surface prescriptions. We adopt the spatial resolution averaged over the field-of-view as the figure of merit M. A more complete description appears in our paper in these proceedings.

Evaluation of cervical lymph nodes in head and neck cancer with CT and MRI: tips, traps, and a systematic approach.

PubMed

Hoang, Jenny K; Vanka, Jyotsna; Ludwig, Benjamin J; Glastonbury, Christine M

2013-01-01

In this article, we present a 4-step approach to evaluating lymph nodes in the setting of head and neck squamous cell and thyroid carcinoma and highlight important tips and traps. The presence and extent of nodal metastases in head and neck cancer has a great impact on treatment and prognosis. Pretreatment CT and MRI of the neck are commonly performed to evaluate for nodal metastases.

Rehabilitation R&D Progress Reports 1996, Volume 34, May 1997

DTIC Science & Technology

1997-05-01

Arlington, VA 22230 PURPOSE!—Atrioventricular (AV) nodal alternans is a pathological cardiac condition characterized by a beat - to- beat alternation...regime where the AV nodal conduc- tion time alternated on a beat -to- beat basis. After using additive white noise to learn the dynamics of the underly... binaurally accord- ing to the NAL-R prescriptive formula. These groups will be followed over a period of 6 months and tested at monthly intervals. At each

Theoretical and Experimental Evidence for a Nodal Energy Gap in MgB2

DTIC Science & Technology

2017-02-17

1   Theoretical and Experimental Evidence for a Nodal Energy Gap in MgB2 Y. Dan Agassia and Daniel E. Oatesb aConsultant, Jerusalem, Israel bMIT...surface impedance and intermodulation distortion in high-quality thin films. We briefly review experimental evidence in support of our hypothesis and...demonstrates, this experimental evidence agrees with the l = 6 hypothesis, while inconsistent with s-wave symmetry. To give the l = 6 hypothesis a

Laminated Composite Shell Element Using Absolute Nodal Coordinate Formulation and Its Application to ANCF Tire Model

DTIC Science & Technology

2015-04-24

Paramsothy Jayakumar US Army TARDEC 6501 E. 11 Mile Road Warren, MI 48397-5000 Hiroyuki Sugiyama Department of Mechanical and Industrial...Part 2: Development of a Physical Tyre Model", Vehicle System Dynamics, vol. 50, pp. 339-356. [4] Sugiyama, H., Yamashita, H. and Jayakumar , P., 2014... Jayakumar , P. and Sugiyama, H., "Continuum Mechanics Based Bi-Linear Shear Deformable Shell Element using Absolute Nodal Coordinate Formulation", ASME

The Role of Cerl2 in the Establishment of Left-Right Asymmetries during Axis Formation and Heart Development

PubMed Central

2017-01-01

The formation of the asymmetric left-right (LR) body axis is one of the fundamental aspects of vertebrate embryonic development, and one still raising passionate discussions among scientists. Although the conserved role of nodal is unquestionable in this process, several of the details around this signaling cascade are still unanswered. To further understand this mechanism, we have been studying Cerberus-like 2 (Cerl2), an inhibitor of Nodal, and its role in the generation of asymmetries in the early vertebrate embryo. The absence of Cerl2 results in a wide spectrum of malformations commonly known as heterotaxia, which comprises defects in either global organ position (e.g., situs inversus totalis), reversed orientation of at least one organ (e.g., situs ambiguus), and mirror images of usually asymmetric paired organs (e.g., left or right isomerisms of the lungs). Moreover, these laterality defects are frequently associated with congenital heart diseases (e.g., transposition of the great arteries, or atrioventricular septal defects). Here, reviewing the knowledge on the establishment of LR asymmetry in mouse embryos, the emerging conclusion is that as necessary as is the activation of the Nodal signaling cascade, the tight control that Cerl2-mediates on Nodal signaling is equally important, and that generates a further regionalized LR genetic program in the proper time and space. PMID:29367552

Prevalence, location and concurrent diseases of ultrasonographic cyst-like lesions of abdominal lymph nodes in dogs.

PubMed

Liotta, A; Billen, F; Heimann, M; Hamaide, A; Rizza, M; Etienne, A L; Bolen, G

2017-04-01

Lymph nodal cyst-like lesions are occasionally identified during abdominal ultrasound in dogs. However, a study evaluating their prevalence and clinical significance is lacking. The aim of this observational cross-sectional study was to evaluate prevalence, most common location and concurrent diseases of cyst-like lymph nodes detected during abdominal ultrasound. Affected lymph nodes, patient signalment and concurrent diseases of dogs with cyst-like lymph nodal lesions having undergone abdominal ultrasound over a one-year period were recorded. Twenty-three affected lymph nodes were observed in 17/553 dogs (prevalence=3 per cent). The most commonly affected was the lumbar lymphocenter (7/23), followed by the coeliac (6/23), the cranial mesenteric (5/23) and the iliosacral (5/23). Twenty-three concurrent diseases were diagnosed in 17 dogs, among which 16/23 were non-neoplastic (70 per cent). The most common concurrent disease was renal insufficiency (8/23), followed by neoplasia (7/23), gastroenteropathy (3/23), benign prostatic disease (2/23), pancreatitis (1/23), peritonitis (1/23) and neurological disease (1/23). No statistical correlation existed between cyst-like lymph nodal lesion and a specific neoplastic or non-neoplastic disease. In conclusion, in the present study, cyst-like lymph nodal lesions have a low prevalence, involve different lymphocenters and were found in dogs affected by different diseases, including both non-neoplastic and neoplastic aetiologies. British Veterinary Association.

A diagnosis model for early Tourette syndrome children based on brain structural network characteristics

NASA Astrophysics Data System (ADS)

Wen, Hongwei; Liu, Yue; Wang, Jieqiong; Zhang, Jishui; Peng, Yun; He, Huiguang

2016-03-01

Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder characterized by the presence of multiple motor and vocal tics. Tic generation has been linked to disturbed networks of brain areas involved in planning, controlling and execution of action. The aim of our work is to select topological characteristics of structural network which were most efficient for estimating the classification models to identify early TS children. Here we employed the diffusion tensor imaging (DTI) and deterministic tractography to construct the structural networks of 44 TS children and 48 age and gender matched healthy children. We calculated four different connection matrices (fiber number, mean FA, averaged fiber length weighted and binary matrices) and then applied graph theoretical methods to extract the regional nodal characteristics of structural network. For each weighted or binary network, nodal degree, nodal efficiency and nodal betweenness were selected as features. Support Vector Machine Recursive Feature Extraction (SVM-RFE) algorithm was used to estimate the best feature subset for classification. The accuracy of 88.26% evaluated by a nested cross validation was achieved on combing best feature subset of each network characteristic. The identified discriminative brain nodes mostly located in the basal ganglia and frontal cortico-cortical networks involved in TS children which was associated with tic severity. Our study holds promise for early identification and predicting prognosis of TS children.

[Alterations of brain network efficiency in patients with post-concussion syndrome].

PubMed

Peng, Nan; Qian, Ruobing; Fu, Xianming; Li, Shunli; Kang, Zhiqiang; Lin, Bin; Ji, Xuebing; Wei, Xiangpin; Niu, Chaoshi; Wang, Yehan

2015-07-07

To discuss the alterations of brain network efficiency in patients with post-concussion syndrome. A total of 23 patients from Anhui Provincial Hospital in the period from 2013/6 to 2014/3 who have had the concussion for 3 months were enrolled and 23 volunteers paired in sex, age and education were also enrolled as healthy controls. Comparisons of selective attention of both groups were conducted using Stroop Word-Color Test. The data of resting-state functional magnetic resonance imaging (fMRI) in both groups were collected and the data were dealt with Network Construction which is a part of GRETNA software to obtain the Matrix of brain network. Network analysis was used to obtain Global and Nodal efficiency, then independent t-test was used for statistical analyses of the value of Global and Nodal efficiency. The difference in Global efficiency of two groups in every threshold value had no statistical significance. Compared with healthy controls, the Nodal efficiencies in patients with post-concussion syndrome were significantly different in the brain regions as below: left orbital middle frontal gyrus, left posterior cingulate, left lingual, left thalamus, left superior temporal gyrus, right anterior cingulate, right posterior cingulate, right supramarginalgyrus. Compared with healthy controls, there is no significant changes of Globe efficiency in patients with post-concussion syndrome, and the brain function deficits in these patients may be caused by changes of Nodal efficiency in their brain network.

Disrupted topological organization in whole-brain functional networks of heroin-dependent individuals: a resting-state FMRI study.

PubMed

Jiang, Guihua; Wen, Xue; Qiu, Yingwei; Zhang, Ruibin; Wang, Junjing; Li, Meng; Ma, Xiaofen; Tian, Junzhang; Huang, Ruiwang

2013-01-01

Neuroimaging studies have shown that heroin addiction is related to abnormalities in widespread local regions and in the functional connectivity of the brain. However, little is known about whether heroin addiction changes the topological organization of whole-brain functional networks. Seventeen heroin-dependent individuals (HDIs) and 15 age-, gender-matched normal controls (NCs) were enrolled, and the resting-state functional magnetic resonance images (RS-fMRI) were acquired from these subjects. We constructed the brain functional networks of HDIs and NCs, and compared the between-group differences in network topological properties using graph theory method. We found that the HDIs showed decreases in the normalized clustering coefficient and in small-worldness compared to the NCs. Furthermore, the HDIs exhibited significantly decreased nodal centralities primarily in regions of cognitive control network, including the bilateral middle cingulate gyrus, left middle frontal gyrus, and right precuneus, but significantly increased nodal centralities primarily in the left hippocampus. The between-group differences in nodal centralities were not corrected by multiple comparisons suggesting these should be considered as an exploratory analysis. Moreover, nodal centralities in the left hippocampus were positively correlated with the duration of heroin addiction. Overall, our results indicated that disruptions occur in the whole-brain functional networks of HDIs, findings which may be helpful in further understanding the mechanisms underlying heroin addiction.

Effect of Resting-State fNIRS Scanning Duration on Functional Brain Connectivity and Graph Theory Metrics of Brain Network.

PubMed

Geng, Shujie; Liu, Xiangyu; Biswal, Bharat B; Niu, Haijing

2017-01-01

As an emerging brain imaging technique, functional near infrared spectroscopy (fNIRS) has attracted widespread attention for advancing resting-state functional connectivity (FC) and graph theoretical analyses of brain networks. However, it remains largely unknown how the duration of the fNIRS signal scanning is related to stable and reproducible functional brain network features. To answer this question, we collected resting-state fNIRS signals (10-min duration, two runs) from 18 participants and then truncated the hemodynamic time series into 30-s time bins that ranged from 1 to 10 min. Measures of nodal efficiency, nodal betweenness, network local efficiency, global efficiency, and clustering coefficient were computed for each subject at each fNIRS signal acquisition duration. Analyses of the stability and between-run reproducibility were performed to identify optimal time length for each measure. We found that the FC, nodal efficiency and nodal betweenness stabilized and were reproducible after 1 min of fNIRS signal acquisition, whereas network clustering coefficient, local and global efficiencies stabilized after 1 min and were reproducible after 5 min of fNIRS signal acquisition for only local and global efficiencies. These quantitative results provide direct evidence regarding the choice of the resting-state fNIRS scanning duration for functional brain connectivity and topological metric stability of brain network connectivity.

Ringin' the water bell: dynamic modes of curved fluid sheets

NASA Astrophysics Data System (ADS)

Kolinski, John; Aharoni, Hillel; Fineberg, Jay; Sharon, Eran

2015-11-01

A water bell is formed by fluid flowing in a thin, coherent sheet in the shape of a bell. Experimentally, a water bell is created via the impact of a cylindrical jet on a flat surface. Its shape is set by the splash angle (the separation angle) of the resulting cylindrically symmetric water sheet. The separation angle is altered by adjusting the height of a lip surrounding the impact point, as in a water sprinkler. We drive the lip's height sinusoidally, altering the separation angle, and ringin' the water bell. This forcing generates disturbances on the steady-state water bell that propagate forward and backward in the fluid's reference frame at well-defined velocities, and interact, resulting in the emergence of an interference pattern unique to each steady-state geometry. We analytically model these dynamics by linearizing the amplitude of the bell's response about the underlying curved geometry. This simple model predicts the nodal structure over a wide range of steady-state water bell configurations and driving frequencies. Due to the curved water bell geometry, the nodal structure is quite complex; nevertheless, the predicted nodal structure agrees extremely well with the experimental data. When we drive the bell beyond perturbative separation angles, the nodal locations surprisingly persist, despite the strikingly altered underlying water bell shape. At extreme driving amplitudes the water sheet assumes a rich variety of tortuous, non-convex shapes; nevertheless, the fluid sheet remains intact.

Lymphovascular Invasion Increases the Risk of Nodal and Distant Recurrence in Node-Negative Stage I-IIA Non-Small-Cell Lung Cancer.

PubMed

Sung, Soo Yoon; Kwak, Yoo-Kang; Lee, Sea-Won; Jo, In Young; Park, Jae Kil; Kim, Kyung Soo; Lee, Kyo Young; Kim, Yeon-Sil

2018-05-30

Despite complete surgical resection, 30-40% of patients with stage I-IIA non-small-cell lung cancer (NSCLC) have recurrences. We aimed to elucidate the effect of lymphovascular invasion (LVI) on the prognosis and patterns of recurrence in patients with pathologically confirmed T1-2N0 NSCLC. We evaluated 381 patients who underwent complete resection and were diagnosed with pathologic T1-2N0 NSCLC between March 2000 and January 2012. Local recurrence, nodal recurrence, and distant metastasis were defined and analyzed. LVI was present in 72 patients (18.9%). The 5-year disease-free survival (DFS) for all patients was 69.9%. Patients with LVI showed a significant decrease in 5-year DFS (47.3 vs. 74.4%, p < 0.001). LVI was a significant prognostic predictor in multivariate analysis (p = 0.003). The patients with LVI showed a significantly increased 5-year cumulative incidence of nodal recurrence (22.5 vs. 8.7%, p < 0.001) and distant metastasis (30.4 vs. 14.9%, p = 0.004). However, no difference was shown between the two groups in the 5-year cumulative incidence of local recurrence (p = 0.416). LVI is a negative prognostic factor in patients with stage I-IIA NSCLC. The presence of LVI significantly increases the risk of nodal and distant recurrence. © 2018 S. Karger AG, Basel.

The association between smoking and breast cancer characteristics and outcome.

PubMed

Goldvaser, Hadar; Gal, Omer; Rizel, Shulamith; Hendler, Daniel; Neiman, Victoria; Shochat, Tzippy; Sulkes, Aaron; Brenner, Baruch; Yerushalmi, Rinat

2017-09-06

Smoking is associated with an increased incidence of hormone receptor positive breast cancer. Data regarding worse breast cancer outcome in smokers are accumulating. Current literature regarding the impact of smoking on breast cancer characteristics is limited. We evaluated the impact of smoking on breast cancer characteristics and outcome. This was a retrospective single center study. All women diagnosed from 4/2005 through 3/2012 and treated in our institute for early, estrogen receptor positive, human epidermal growth factor receptor 2 (HER2) negative breast cancer, whose tumors were sent for Oncotype DX analysis were included. Medical records were reviewed for demographics, clinico-pathological parameters, treatment and outcome. Data regarding smoking were retrieved according to patients' history at the first visit in the oncology clinic. Patients were grouped and compared according to smoking history (ever smokers vs. never smokers), smoking status (current vs. former and never smokers) and smoking intensity (pack years ≥30 vs. the rest of the cohort). Outcomes were adjusted in multivariate analyses and included age, menopausal status, ethnicity, tumor size, nodal status and grade. A total of 662 women were included. 28.2% had a history of smoking, 16.6% were current smokers and 11.3% were heavy smokers. Smoking had no impact on tumor size, nodal involvement and Oncotype DX recurrence score. Angiolymphatic and perineural invasion rates were higher in current smokers than in the rest of the cohort (10.4% vs. 5.1%, p = 0.045, 8.3% vs. 3.5%, p = 0.031, respectively). Smoking had no other impact on histological characteristics. Five-year disease free survival and overall survival rates were 95.7% and 98.5%, respectively. Smoking had no impact on outcomes. Adjusted disease free survival and overall survival did not influence the results. Smoking had no clinically significant influence on tumor characteristics and outcome among women with estrogen receptor positive, HER2 negative, early breast cancer. As the study was limited to a specific subgroup of the breast cancer population in this heterogeneous disease and since smoking is a modifiable risk factor for the disease, further research is required to clarify the possible impact of smoking on breast cancer.

Cross-contact chain

NASA Technical Reports Server (NTRS)

Lieneweg, Udo (Inventor)

1988-01-01

A system is provided for use with wafers that include multiple integrated circuits that include two conductive layers in contact at multiple interfaces. Contact chains are formed beside the integrated circuits, each contact chain formed of the same two layers as the circuits, in the form of conductive segments alternating between the upper and lower layers and with the ends of the segments connected in series through interfaces. A current source passes a current through the series-connected segments, by way of a pair of current tabs connected to opposite ends of the series of segments. While the current flows, voltage measurements are taken between each of a plurality of pairs of voltage tabs, the two tabs of each pair connected to opposite ends of an interface that lies along the series-connected segments. A plot of interface conductances on a normal probability chart, enables prediction of the yield of good integrated circuits from the wafer.

Cross-contact chain

NASA Technical Reports Server (NTRS)

Lieneweg, U. (Inventor)

1986-01-01

A system is provided for use with wafers that include multiple integrated circuits that include two conductive layers in contact at multiple interfaces. Contact chains are formed beside the integrated circuits, each contact chain formed of the same two layers as the circuits, in the form of conductive segments alternating between the upper and lower layers and with the ends of the segments connected in series through interfaces. A current source passes a current through the series-connected segments, by way of a pair of current tabs connected to opposite ends of the series of segments. While the current flows, voltage measurements are taken between each of a plurality of pairs of voltage tabs, the two tabs of each pair connected to opposite ends of an interface that lies along the series-connected segments. A plot of interface conductances on normal probability chart enables prediction of the yield of good integrated circuits from the wafer.

Spin pumping and inverse Rashba-Edelstein effect in NiFe/Ag/Bi and NiFe/Ag/Sb

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

Zhang, Wei; Jungfleisch, Matthias B.; Jiang, Wanjun

2015-03-20

The Rashba effect is an interaction between the spin and the momentum of electrons induced by the spin-orbit coupling in surface or interface states. Here, we measured the inverse Rashba-Edelstein effect via spin pumping in Ag/Bi and Ag/Sb interfaces. The spin current is injected from the ferromagnetic resonance of a NiFe layer towards the Rashba interfaces, where it is further converted into a charge current. While using spin pumping theory, we quantify the conversion parameter of spin to charge current to be 0.11 ± 0.02 nm for Ag/Bi and a factor of ten smaller for Ag/Sb. Furthermore, the relative strengthmore » of the effect is in agreement with spectroscopic measurements and first principles calculations. The spin pumping experiment offers a straight-forward approach of using spin current as an efficient probe for detecting interface Rashba splitting.« less

Current limiting remote power control module

NASA Technical Reports Server (NTRS)

Hopkins, Douglas C.

1990-01-01

The power source for the Space Station Freedom will be fully utilized nearly all of the time. As such, any loads on the system will need to operate within expected limits. Should any load draw an inordinate amount of power, the bus voltage for the system may sag and disrupt the operation of other loads. To protect the bus and loads some type of power interface between the bus and each load must be provided. This interface is most crucial when load faults occur. A possible system configuration is presented. The proposed interface is the Current Limiting Remote Power Controller (CL-RPC). Such an interface should provide the following power functions: limit overloading and resulting undervoltage; prevent catastrophic failure and still provide for redundancy management within the load; minimize cable heating; and provide accurate current measurement. A functional block diagram of the power processing stage of a CL-RPC is included. There are four functions that drive the circuit design: rate control of current; current sensing; the variable conductance switch (VCS) technology; and the algorithm used for current limiting. Each function is discussed separately.

DMA shared byte counters in a parallel computer

DOEpatents

Chen, Dong; Gara, Alan G.; Heidelberger, Philip; Vranas, Pavlos

2010-04-06

A parallel computer system is constructed as a network of interconnected compute nodes. Each of the compute nodes includes at least one processor, a memory and a DMA engine. The DMA engine includes a processor interface for interfacing with the at least one processor, DMA logic, a memory interface for interfacing with the memory, a DMA network interface for interfacing with the network, injection and reception byte counters, injection and reception FIFO metadata, and status registers and control registers. The injection FIFOs maintain memory locations of the injection FIFO metadata memory locations including its current head and tail, and the reception FIFOs maintain the reception FIFO metadata memory locations including its current head and tail. The injection byte counters and reception byte counters may be shared between messages.

Lymph node density vs. the American Joint Committee on Cancer TNM nodal staging system in node-positive bladder cancer in patients undergoing extended or super-extended pelvic lymphadenectomy.

PubMed

Lee, Donghyun; Yoo, Sangjun; You, Dalsan; Hong, Bumsik; Cho, Yong Mee; Hong, Jun Hyuk; Kim, Choung-Soo; Ahn, Hanjonh; Ro, Jae Y; Jeong, In Gab

2017-04-01

We compared the prognostic value of the American Joint Committee on Cancer (AJCC) TNM nodal staging system with that of lymph node (LN) density in patients with LN-positive bladder cancer who received extended or super-extended pelvic lymphadenectomy. Of the 1,018 patients, who underwent radical cystectomy and pelvic lymphadenectomy between February 2005 and August 2014, 110 patients with LN metastases with extended (n = 68) or super-extended (n = 42) pelvic lymphadenectomy were included. All patients were staged using the 2002 (sixth edition) and 2010 (seventh edition) AJCC TNM staging systems. The association of several variables with recurrence-free survival (RFS) and overall survival (OS) was evaluated. The median number of total LNs removed was 29 (6-118) and the median LN density was 12.5% (1.6%-100%). RFS and OS were not significantly different between the 2002 (pN1-pM1) and 2010 (pN1-N3) AJCC TNM nodal staging systems (sixth edition: P = 0.512 and P = 0.519; seventh edition: P = 0.676 and P = 0.671, respectively). The 2-year RFS and OS rates according to the LN density quartiles were 58.5% and 76.9% in Q1, 39.1% and 70.8% in Q2, 28.8% and 50.1% in Q3, and 12.7% and 20.8% in Q4 (P = 0.001 and P = 0.001, respectively). Multivariate analysis adjusted for the 2010 AJCC TNM staging system showed that LN density was associated with a decreased OS (HR = 1.024; 95% CI: 1.010-1.039; P = 0.001). The nodal staging system (2002 or 2010) was not associated with the RFS and OS. LN density shows a better prognostic value than the AJCC TNM nodal staging system in patients with LN-positive bladder cancer receiving extended or super-extended pelvic lymphadenectomy. Copyright © 2017 Elsevier Inc. All rights reserved.

PITX2 and NODAL expression during axis formation in the early rabbit embryo.

PubMed

Plöger, Ruben; Viebahn, Christoph

2018-04-26

Attaining molecular and morphological axial polarity during gastrulation is a fundamental early requirement for normal development of the embryo. In mammals, the first morphological sign of the anterior-posterior axis appears anteriorly in the form of the anterior marginal crescent (or anterior visceral endoderm) while in the avian the first such sign is the Koller's sickle at the posterior pole of the embryonic disc. Despite this inverse mode of axis formation many genes and molecular pathways involved in various steps of this process seem to be evolutionary conserved amongst amniotes, the nodal gene being a well-known example with its functional involvement prior and during gastrulation. The pitx2 gene, however, is a new candidate described in the chick as an early marker for anterior-posterior polarity and as regulator of axis formation including twinning. To find out whether pitx2 has retained its inductive and early marker function during the evolution of mammals, this study analyzes pitx2 and nodal expression at parallel stages during formation of the anterior-posterior polarity in the early rabbit embryo using whole-mount in situ hybridization and serial light-microscopical sections. At a late pre-gastrulation stage a localized reduction of nodal expression presages the position of the anterior pole of the embryonic disc and thus serves as the earliest molecular marker of anterior-posterior polarity known so far. pitx2 is expressed in a polarized manner in the anterior marginal crescent and in the posterior half of the embryonic disc during further development only while nodal expression in the anterior segment of the posterior pitx2 expression domain helps to define the so-called anterior streak domain (ASD), a novel progenitor region of the anterior half of the primitive streak. The expression patterns of both genes thus serve as signs of a conserved involvement in early axis formation in amniotes and, possibly, in twinning in mammals as well. Copyright © 2018 Elsevier GmbH. All rights reserved.

Is there a benefit to adjuvant radiation in stage III penile cancer after lymph node dissection? Findings from the National Cancer Database.

PubMed

Winters, Brian R; Kearns, James T; Holt, Sarah K; Mossanen, Matthew; Lin, Daniel W; Wright, Jonathan L

2018-03-01

The role of adjuvant radiation in advanced penile cancer (PC) is unknown. We used the National Cancer Database (NCDB) to determine factors associated with receiving adjuvant radiation (aXRT) and their influence on prognosis in men who underwent inguinal lymph node dissection (ILND) for stage III disease. We queried the NCDB from 1998-2012 for all men with PC who had pathologic nodal status and aXRT data available. Clinical and pathologic variables associated with aXRT were examined using chi-square testing. Logistic regression evaluated the odds of receiving aXRT while multivariate Cox regression analysis evaluated the influence of aXRT on overall survival (OS). A total of 589 patients underwent ILND for stage III PC with 23% (N = 136) receiving aXRT. Mean age was 61.8 ±13.7 years. Factors associated with receiving aXRT included higher pathologic nodal stage (MV OR 1.85, 95% CI: 1.13-3.05), while greater distance of travel (MV OR 0.48, 95% CI: 0.25-0.92), and treatment in an academic setting (MV OR 0.53, 95% CI: 0.35-0.81) were inversely associated with receiving aXRT. On Cox regression analysis, aXRT improved OS (combined HR 0.58, 95% CI: 0.39-0.86), which appeared to have been driven by higher nodal burden (N2: HR 0.53, 95% CI: 0.32-0.88; N1: HR 1.36, 95% CI: 0.60-3.09). Determinants of aXRT delivery in stage III PC appear to be related to the proximity to community cancer centers and greater nodal burden. We find evidence of a survival benefit with the use of aXRT, particularly in those with higher nodal stage. Multi-institutional studies are needed to confirm these findings and improve treatment algorithms for high-stage PC. Copyright © 2018 Elsevier Inc. All rights reserved.

Preoperative axillary lymph node evaluation in breast cancer patients by breast magnetic resonance imaging (MRI): Can breast MRI exclude advanced nodal disease?

PubMed

Hyun, Su Jeong; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Kim, Min Jung

2016-11-01

To evaluate the diagnostic performance of breast magnetic resonance imaging (MRI) in preoperative evaluation of axillary lymph node metastasis (ALNM) in breast cancer patients and to assess whether breast MRI can be used to exclude advanced nodal disease. A total of 425 patients were included in this study and breast MRI findings were retrospectively reviewed. The diagnostic performance of breast MRI for diagnosis of ALNM was evaluated in all patients, patients with neoadjuvant chemotherapy (NAC), and those without NAC (no-NAC). We evaluated whether negative MRI findings (cN0) can exclude advanced nodal disease (pN2-pN3) using the negative predictive value (NPV) in each group. The sensitivity and NPV of breast MRI in evaluation of ALNM was 51.3 % (60/117) and 83.3 % (284/341), respectively. For cN0 cases on MRI, pN2-pN3 manifested in 1.8 % (6/341) of the overall patients, 0.4 % (1/257) of the no-NAC group, and 6 % (5/84) of the NAC group. The NPV of negative MRI findings for exclusion of pN2-pN3 was higher for the no-NAC group than for the NAC group (99.6 % vs. 94.0 %, p = 0.039). Negative MRI findings (cN0) can exclude the presence of advanced nodal disease with an NPV of 99.6 % in the no-NAC group. • Breast MRI can be used to exclude advanced nodal disease (pN2-3). • Negative MRI allows breast cancer patients to avoid unnecessary axillary surgery (98.2 %). • Negative MRI findings exclude 99.6 % of pN2-pN3 in the no-NAC group. • Negative MRI findings exclude 96.0 % of pN2-pN3 in the NAC group.

The role of elective nodal irradiation for esthesioneuroblastoma patients with clinically negative neck.

PubMed

Jiang, Wen; Mohamed, Abdallah S R; Fuller, Clifton David; Kim, Betty Y S; Tang, Chad; Gunn, G Brandon; Hanna, Ehab Y; Frank, Steven J; Su, Shirley Y; Diaz, Eduardo; Kupferman, Michael E; Beadle, Beth M; Morrison, William H; Skinner, Heath; Lai, Stephen Y; El-Naggar, Adel K; DeMonte, Franco; Rosenthal, David I; Garden, Adam S; Phan, Jack

2016-01-01

Although adjuvant radiation to the tumor bed has been reported to improve the clinic outcomes of esthesioneuroblastoma (ENB) patients, the role of elective neck irradiation (ENI) in clinically node-negative (N0) patients remains controversial. Here, we evaluated the effects of ENI on neck nodal relapse risk in ENB patients treated with radiation therapy as a component of multimodality treatment. Seventy-one N0 ENB patients irradiated at the University of Texas MD Anderson Cancer Center between 1970 and 2013 were identified. ENI was performed on 22 of these patients (31%). Survival analysis was performed with focus on comparative outcomes of those patients who did and did not receive ENI. The median follow-up time for our cohort is 80.8 months (range, 6-350 months). Among N0 patients, 13 (18.3%) developed neck nodal relapses, with a median time to progression of 62.5 months. None of these 13 patients received prophylactic neck irradiation. ENI was associated with significantly improved regional nodal control at 5 years (regional control rate of 100% for ENI vs 82%, P < .001), but not overall survival or disease-free survival. Eleven patients without ENI developed isolated neck recurrences. All had further treatment for their neck disease, including neck dissection (n = 10), radiation (n = 10), or chemotherapy (n = 5). Six of these 11 patients (54.5%) demonstrated no evidence of further recurrence with a median follow-up of 55.5 months. ENI significantly reduces the risk of cervical nodal recurrence in ENB patients with clinically N0 neck, but this did not translate to a survival benefit. Multimodality treatment for isolated neck recurrence provides a reasonable salvage rate. The greatest benefit for ENI appeared to be among younger patients who presented with Kadish C disease. Further studies are needed to confirm these findings. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

The role of elective-nodal irradiation for esthesioneuroblastoma patients with clinically negative neck

PubMed Central

Jiang, Wen; Mohamed, Abdallah Sherif; Fuller, Clifton David; Kim, Betty Y.S.; Tang, Chad; Gunn, G. Brandon; Hanna, Ehab Y.; Frank, Steven J.; Su, Shirley Y.; Diaz, Eduardo; Kupferman, Michael E.; Beadle, Beth M.; Morrison, William H.; Skinner, Heath; Lai, Stephen Y.; El-Naggar, Adel K.; DeMonte, Franco; Rosenthal, David I.; Garden, Adam S.; Phan, Jack

2017-01-01

Purpose Although adjuvant radiation to the tumor bed has been reported to improve the clinic outcomes of esthesioneuroblastoma (ENB) patients, the role of elective neck irradiation (ENI) in clinically node negative (N0) patients remains controversial. Here, we evaluated the effects of ENI on neck nodal relapse risk in ENB patients treated with radiotherapy as a component of multi-modality treatment. Methods and Materials Seventy-one N0 ENB patients irradiated at XXXXXXXXX between 1970 and 2013 were identified. ENI was performed on 22 of these patients (31%). Survival analysis was performed with focus on comparative outcomes of those patients who did and did not receive ENI. Results The median follow up time for our cohort is 80.8 months (range 6 – 350 month). Among N0 patients, 13 (18.3%) developed neck nodal relapses, with a median time to progression of 62.5 months. None of these 13 patients received prophylactic neck irradiation. ENI was associated with significantly improved regional nodal control at 5-year (regional control rate of 100% for ENI vs 82%, p < 0.001), but not overall survival or disease-free survival. Eleven patients without ENI developed isolated neck recurrences. All had further treatment for their neck disease, including neck dissection (n=10), radiation (n=10), or chemotherapy (n=5). Six of these 11 patients (54.5%) demonstrated no evidence of further recurrence with a median follow up of 55.5 month. Conclusion ENI significantly reduces the risk of cervical nodal recurrence in ENB patients with clinically N0 neck but this did not translate to a survival benefit. Multimodality treatment for isolated neck recurrence provides a reasonable salvage rate. The greatest benefit for ENI appeared to be among younger patients who presented with Kadish C disease. Further studies are needed to confirm these findings. PMID:26979544

Three-dimensional conformal radiation for esophageal squamous cell carcinoma with involved-field irradiation may deliver considerable doses of incidental nodal irradiation

PubMed Central

2012-01-01

Background To quantify the incidental irradiation dose to esophageal lymph node stations when irradiating T1-4N0M0 thoracic esophageal squamous cell carcinoma (ESCC) patients with a dose of 60 Gy/30f. Methods Thirty-nine patients with medically inoperable T1–4N0M0 thoracic ESCC were treated with three-dimensional conformal radiation (3DCRT) with involved-field radiation (IFI). The conformal clinical target volume (CTV) was re-created using a 3-cm margin in the proximal and distal direction beyond the barium esophagogram, endoscopic examination and CT scan defined the gross tumor volume (GTV) and a 0.5-cm margin in the lateral and anteroposterior directions of the CT scan-defined GTV. The PTV encompassed 1-cm proximal and distal margins and 0.5-cm radial margin based on the CTV. Nodal regions were delineated using the Japanese Society for Esophageal Diseases (JSED) guidelines and an EORTC-ROG expert opinion. The equivalent uniform dose (EUD) and other dosimetric parameters were calculated for each nodal station. Nodal regions with a metastasis rate greater than 5% were considered a high-risk lymph node subgroup. Results Under a 60 Gy dosage, the median Dmean and EUD was greater than 40 Gy in most high-risk nodal regions except for regions of 104, 106tb-R in upper-thoracic ESCC and 101, 104-R, 105, 106rec-L, 2, 3&7 in middle-thoracic ESCC and 107, 3&7 in lower-thoracic ESCC. In the regions with an EUD less than 40Gy, most incidental irradiation doses were significantly associated with esophageal tumor length and location. Conclusions Lymph node stations near ESCC receive considerable incidental irradiation doses with involved-field irradiation that may contribute to the elimination of subclinical lesions. PMID:23186308

An immersed boundary method for fluid-structure interaction with compressible multiphase flows

NASA Astrophysics Data System (ADS)

Wang, Li; Currao, Gaetano M. D.; Han, Feng; Neely, Andrew J.; Young, John; Tian, Fang-Bao

2017-10-01

This paper presents a two-dimensional immersed boundary method for fluid-structure interaction with compressible multiphase flows involving large structure deformations. This method involves three important parts: flow solver, structure solver and fluid-structure interaction coupling. In the flow solver, the compressible multiphase Navier-Stokes equations for ideal gases are solved by a finite difference method based on a staggered Cartesian mesh, where a fifth-order accuracy Weighted Essentially Non-Oscillation (WENO) scheme is used to handle spatial discretization of the convective term, a fourth-order central difference scheme is employed to discretize the viscous term, the third-order TVD Runge-Kutta scheme is used to discretize the temporal term, and the level-set method is adopted to capture the multi-material interface. In this work, the structure considered is a geometrically non-linear beam which is solved by using a finite element method based on the absolute nodal coordinate formulation (ANCF). The fluid dynamics and the structure motion are coupled in a partitioned iterative manner with a feedback penalty immersed boundary method where the flow dynamics is defined on a fixed Lagrangian grid and the structure dynamics is described on a global coordinate. We perform several validation cases (including fluid over a cylinder, structure dynamics, flow induced vibration of a flexible plate, deformation of a flexible panel induced by shock waves in a shock tube, an inclined flexible plate in a hypersonic flow, and shock-induced collapse of a cylindrical helium cavity in the air), and compare the results with experimental and other numerical data. The present results agree well with the published data and the current experiment. Finally, we further demonstrate the versatility of the present method by applying it to a flexible plate interacting with multiphase flows.

Effect of nifedipine on atrioventricular conduction as compared with verapamil. Intracardiac electrophysiological study.

PubMed Central

Rowland, E; Evans, T; Krikler, D

1979-01-01

Intravenous nifedipine, a powerful calcium antagonist, had no obvious effect on atrioventricular conduction when administered to 11 patients during routine intracardiac electrophysiological studies. Verapamil on the other hand showed potent antiarrhythmic properties, depressing atrioventricular nodal conduction. Nifedipine thus appears safe in patients with angina pectoris who have disorders of atrioventricular nodal conduction, and in those receiving beta-adrenergic blocking drugs. There appear to be differential effects on the slow inward channels of cardiac cells with different 'calcium antagonists'. PMID:486272

A Nodal Domain Integration Model of Two-Dimensional Heat and Soil-Water Flow Coupled by Soil-Water Phase Change.

DTIC Science & Technology

1987-06-01

WORK UNIT ELEMENT NO. NO NO ACCESSION NO I I ICWIS 31711 11 TITLE (Include Security Classification) A Nodal Domain Integration Model of Two...t.5% Unclassified."- .-,,. PREFACE This report was prepared by Ted Hromadka, Director of Water Re- sources, Williamson and Schmid. The work was...performed for CRREL under Contract 84-M-1691 and was funded by the Directorate of Civil Works , Office of the Chief of Engineers, under Civil Works Order No

Primary Germ Cell Tumor of Testes with Extensive Lymph Nodal and Splenic Metastases Masquerading Lymphoma on 18-F-FDG PET/CT

PubMed Central

Tripathy, Sarthak; Mukherjee, Anirban; Bal, Chandrasekhar; Tripathi, Madhavi; Mallick, Saumyaranjan; Shamim, Shamim Ahmed

2017-01-01

Germ cell tumors (GCT) account for the 95% of the malignancies associated with testes. They are the most common solid malignancies affecting the males in the age group of 15–35 years. It is known to be bilateral in 3% of cases. We herein present FDG PET-CT findings of a case with biopsy proven GCT with multiple lymph nodal and splenic metastases mimicking lymphomatous neoplasm. PMID:28533651

Three dimensional flow computations in a turbine scroll

NASA Technical Reports Server (NTRS)

Hamed, A.; Ghantous, C. A.

1982-01-01

The compressible three dimensional inviscid flow in the scroll and vaneless nozzle of radial inflow turbines is analyzed. A FORTRAN computer program for the numerical solution of this complex flow field using the finite element method is presented. The program input consists of the mass flow rate and stagnation conditions at the scroll inlet and of the finite element discretization parameters and nodal coordinates. The output includes the pressure, Mach number and velocity magnitude and direction at all the nodal points.

Rotating charged black holes accelerated by an electric field

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

Bicak, Jiri; Kofron, David; Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Am Muehlenberg 1, D-14476 Golm

The Ernst method of removing nodal singularities from the charged C-metric representing a uniformly accelerated black hole with mass m, charge q and acceleration A by 'adding' an electric field E is generalized. Utilizing the new form of the C-metric found recently, Ernst's simple 'equilibrium condition' mA=qE valid for small accelerations is generalized for arbitrary A. The nodal singularity is removed also in the case of accelerating and rotating charged black holes, and the corresponding equilibrium condition is determined.

Development of a Robust and Cost-Effective Friction Stir Welding Process for Use in Advanced Military Vehicles

DTIC Science & Technology

2011-01-01

aluminum alloys, as well 81 as aluminum matrix composites can be readily FSWed; 82 (j) due to lower attendant temperatures, the residual stres - 83 ses... role of the precipitation hardening mechanism in heat- 372treatable alloys is concerned, the following main observations 373can be made. Typically in...stirring/mixing 470(which plays a critical role in weld quality/joint-strength) is 471increased. 472Nodal Velocity Field. The distribution of nodal

Oropharyngeal cancer and human papilloma virus: evolving diagnostic and management paradigms.

PubMed

Buckley, Lisa; Gupta, Ruta; Ashford, Bruce; Jabbour, Joe; Clark, Jonathan R

2016-06-01

The significant increase in human papilloma virus (HPV)-associated oropharyngeal carcinoma (OPC) over recent years has lead to a surge in research and an improved understanding of the disease. Most patients with HPV-associated OPC present with cystic nodal metastases with a small primary tumour, and respond well to all treatment modalities including primary surgery and primary chemoradiotherapy. Current research is evaluating treatment de-escalation to reduce long-term treatment-associated morbidities. Transoral robotic surgery (TORS) is particularly relevant as the transoral approach allows small primary tumours to be removed with lower morbidity than traditional surgical approaches. The current American Joint Committee on Cancer staging system for oropharyngeal cancer does not appropriately stratify HPV-associated OPC; hence, alternative risk stratification and staging classifications are being proposed. © 2015 Royal Australasian College of Surgeons.

Distributed gain in plasmonic reflectors and its use for terahertz generation.

PubMed

Sydoruk, O; Syms, R R A; Solymar, L

2012-08-27

Semiconductor plasmons have potential for terahertz generation. Because practical device formats may be quasi-optical, we studied theoretically distributed plasmonic reflectors that comprise multiple interfaces between cascaded two-dimensional electron channels. Employing a mode-matching technique, we show that transmission through and reflection from a single interface depend on the magnitude and direction of a dc current flowing in the channels. As a result, plasmons can be amplified at an interface, and the cumulative effect of multiple interfaces increases the total gain, leading to plasmonic reflection coefficients exceeding unity. Reversing the current direction in a distributed reflector, however, has the opposite effect of plasmonic deamplification. Consequently, we propose structurally asymmetric resonators comprising two different distributed reflectors and predict that they are capable of terahertz oscillations at low threshold currents.

Directional solidification of a planar interface in the presence of a time-dependent electric current

NASA Technical Reports Server (NTRS)

Brush, L. N.; Coriell, S. R.; Mcfadden, G. B.

1990-01-01

Directional solidification of pure materials and binary alloys with a planar crystal-metal interface in the presence of a time-dependent electric current is considered. For a variety of time-dependent currents, the temperature fields and the interface velocity as functions of time are presented for indium antimonide and bismuth and for the binary alloys germanium-gallium and tin-bismuth. For the alloys, the solid composition is calculated as a function of position. Quantitative predictions are made of the effect of an electrical pulse on the solute distribution in the solidified material.

Lyme Carditis: A Case Involving the Conduction System and Mitral Valve.

PubMed

Patel, Lakir D; Schachne, Jay S

2017-02-01

Lyme disease is the most common tick-borne infection in the Northern hemisphere. Cardiac manifestations of Lyme disease typically include variable atrioventricular nodal block and rarely structural heart pathology. The incidence of Lyme carditis may be underestimated based on current reporting practices of confirmed cases. This case of a 59-year-old man with Lyme carditis demonstrates the unique presentation of widespread conduction system disease, mitral regurgitation, and suspected ischemic disease. Through clinical data, electrocardiograms, and cardiac imaging, we show the progression, and resolution, of a variety of cardiac symptoms attributable to infection with Lyme. [Full article available at http://rimed.org/rimedicaljournal-2017-02.asp].

Preoperative staging of rectal cancer.

PubMed

Yeung, Justin Mc; Ferris, Nicholas J; Lynch, A Craig; Heriot, Alexander G

2009-10-01

Preoperative staging is now an essential factor in the multidisciplinary management of rectal cancer because tumor stage is the strongest predictive factor for recurrence. Preoperative staging of rectal cancer can be divided into either local or distant staging. Local staging incorporates the assessment of mural wall invasion, circumferential resection margin involvement, as well as the nodal status for metastasis. Distant staging assesses for evidence of metastatic disease. The aim of this review is to consider the indications and limitations of the current preoperative imaging modalities for rectal cancer staging including clinical examination, endorectal ultrasound, magnetic resonance imaging, computed tomography and positron emission tomography-computed tomography, with respect to local and distant disease.

Recent Progress in Discrete Dislocation Dynamics and Its Applications to Micro Plasticity

NASA Astrophysics Data System (ADS)

Po, Giacomo; Mohamed, Mamdouh S.; Crosby, Tamer; Erel, Can; El-Azab, Anter; Ghoniem, Nasr

2014-10-01

We present a self-contained review of the discrete dislocation dynamics (DDD) method for the numerical investigation of plasticity in crystals, focusing on recent development and implementation progress. The review covers the theoretical foundations of DDD within the framework of incompatible elasticity, its numerical implementation via the nodal method, the extension of the method to finite domains and several implementation details. Applications of the method to current topics in micro-plasticity are presented, including the size effects in nano-indentation, the evolution of the dislocation microstructure in persistent slip bands, and the phenomenon of dislocation avalanches in micro-pillar compression.

Quantum transport in Dirac materials: Signatures of tilted and anisotropic Dirac and Weyl cones

NASA Astrophysics Data System (ADS)

Trescher, Maximilian; Sbierski, Björn; Brouwer, Piet W.; Bergholtz, Emil J.

2015-03-01

We calculate conductance and noise for quantum transport at the nodal point for arbitrarily tilted and anisotropic Dirac or Weyl cones. Tilted and anisotropic dispersions are generic in the absence of certain discrete symmetries, such as particle-hole and lattice point group symmetries. Whereas anisotropy affects the conductance g , but leaves the Fano factor F (the ratio of shot noise power and current) unchanged, a tilt affects both g and F . Since F is a universal number in many other situations, this finding is remarkable. We apply our general considerations to specific lattice models of strained graphene and a pyrochlore Weyl semimetal.

Single-Crystal Material on Non-Single-Crystalline Substrate

DTIC Science & Technology

1999-02-01

point frit or solder glass can be deposited on a surface and bonded to a second surface using pressure and temperature. A sodium silicate material...interface. A metal or silicide at the bonding interface may be advantageous fQr electrical current conduction across the interface. 10 Applications...substrate, or a silicide or metal to aid bonding and vertical electrical current conduction. In some cases, it is difficult to polish the non- single

Innovations in prosthetic interfaces for the upper extremity.

PubMed

Kung, Theodore A; Bueno, Reuben A; Alkhalefah, Ghadah K; Langhals, Nicholas B; Urbanchek, Melanie G; Cederna, Paul S

2013-12-01

Advancements in modern robotic technology have led to the development of highly sophisticated upper extremity prosthetic limbs. High-fidelity volitional control of these devices is dependent on the critical interface between the patient and the mechanical prosthesis. Recent innovations in prosthetic interfaces have focused on several control strategies. Targeted muscle reinnervation is currently the most immediately applicable prosthetic control strategy and is particularly indicated in proximal upper extremity amputations. Investigation into various brain interfaces has allowed acquisition of neuroelectric signals directly or indirectly from the central nervous system for prosthetic control. Peripheral nerve interfaces permit signal transduction from both motor and sensory nerves with a higher degree of selectivity. This article reviews the current developments in each of these interface systems and discusses the potential of these approaches to facilitate motor control and sensory feedback in upper extremity neuroprosthetic devices.

Dirac Magnon Nodal Loops in Quasi-2D Quantum Magnets.

PubMed

Owerre, S A

2017-07-31

In this report, we propose a new concept of one-dimensional (1D) closed lines of Dirac magnon nodes in two-dimensional (2D) momentum space of quasi-2D quantum magnetic systems. They are termed "2D Dirac magnon nodal-line loops". We utilize the bilayer honeycomb ferromagnets with intralayer coupling J and interlayer coupling J L , which is realizable in the honeycomb chromium compounds CrX 3 (X ≡ Br, Cl, and I). However, our results can also exist in other layered quasi-2D quantum magnetic systems. Here, we show that the magnon bands of the bilayer honeycomb ferromagnets overlap for J L  ≠ 0 and form 1D closed lines of Dirac magnon nodes in 2D momentum space. The 2D Dirac magnon nodal-line loops are topologically protected by inversion and time-reversal symmetry. Furthermore, we show that they are robust against weak Dzyaloshinskii-Moriya interaction Δ DM  < J L and possess chiral magnon edge modes.

Long-time stability effects of quadrature and artificial viscosity on nodal discontinuous Galerkin methods for gas dynamics

NASA Astrophysics Data System (ADS)

Durant, Bradford; Hackl, Jason; Balachandar, Sivaramakrishnan

2017-11-01

Nodal discontinuous Galerkin schemes present an attractive approach to robust high-order solution of the equations of fluid mechanics, but remain accompanied by subtle challenges in their consistent stabilization. The effect of quadrature choices (full mass matrix vs spectral elements), over-integration to manage aliasing errors, and explicit artificial viscosity on the numerical solution of a steady homentropic vortex are assessed over a wide range of resolutions and polynomial orders using quadrilateral elements. In both stagnant and advected vortices in periodic and non-periodic domains the need arises for explicit stabilization beyond the numerical surface fluxes of discontinuous Galerkin spectral elements. Artificial viscosity via the entropy viscosity method is assessed as a stabilizing mechanism. It is shown that the regularity of the artificial viscosity field is essential to its use for long-time stabilization of small-scale features in nodal discontinuous Galerkin solutions of the Euler equations of gas dynamics. Supported by the Department of Energy Predictive Science Academic Alliance Program Contract DE-NA0002378.

Immunocompromised patients with metastatic cutaneous nodal squamous cell carcinoma of the head and neck: Poor outcome unrelated to the index lesion.

PubMed

Lam, Johnson K S; Sundaresan, Puma; Gebski, Val; Veness, Michael J

2018-05-01

Immunocompromised patients with metastatic cutaneous nodal head and neck squamous cell carcinoma (HNSCC) have worse outcomes compared to the immunocompetent. The purpose of this study was to investigate the characteristics of the primary cutaneous squamous cell carcinoma (SCC), nodal pathology, and outcome between these 2 groups. Analysis of a prospective database was performed. A 2:1 pooled analysis selected 46 immunocompetent patients matched with 23 immunocompromised patients. Overall survival (OS) and relapse-free survival (RFS) were calculated using the Kaplan-Meier method. No significant difference was found in the primary tumor characteristics between the 2 groups. In the immunocompromised group, RFS (hazard ratio [HR] 2.70; P = .01) and OS (HR 2.32; P = .04) were significantly worse. Extracapsular spread was present in 100% of the immunocompromised patients. No significant difference was identified in the primary cutaneous SCC between the immunocompetent and immunocompromised patients. Immunosuppression predicted worse outcome. © 2018 Wiley Periodicals, Inc.

Suppressing Ionic Terms with Number-Counting Jastrow Factors in Real Space

DOE PAGES

Goetz, Brett Van Der; Neuscamman, Eric

2017-04-06

Here, we demonstrate that four-body real-space Jastrow factors are, with the right type of Jastrow basis function, capable of performing successful wave function stenciling to remove unwanted ionic terms from an overabundant Fermionic reference without unduly modifying the remaining components. In addition to greatly improving size consistency (restoring it exactly in the case of a geminal power), real-space wave function stenciling is, unlike its Hilbert-space predecessors, immediately compatible with diffusion Monte Carlo, allowing it to be used in the pursuit of compact, strongly correlated trial functions with reliable nodal surfaces. Furthermore, we demonstrate the efficacy of this approach in themore » context of a double bond dissociation by using it to extract a qualitatively correct nodal surface despite being paired with a restricted Slater determinant, that, due to ionic term errors, produces a ground state with a qualitatively incorrect nodal surface when used in the absence of the Jastrow.« less

Suppressing Ionic Terms with Number-Counting Jastrow Factors in Real Space

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

Goetz, Brett Van Der; Neuscamman, Eric

Here, we demonstrate that four-body real-space Jastrow factors are, with the right type of Jastrow basis function, capable of performing successful wave function stenciling to remove unwanted ionic terms from an overabundant Fermionic reference without unduly modifying the remaining components. In addition to greatly improving size consistency (restoring it exactly in the case of a geminal power), real-space wave function stenciling is, unlike its Hilbert-space predecessors, immediately compatible with diffusion Monte Carlo, allowing it to be used in the pursuit of compact, strongly correlated trial functions with reliable nodal surfaces. Furthermore, we demonstrate the efficacy of this approach in themore » context of a double bond dissociation by using it to extract a qualitatively correct nodal surface despite being paired with a restricted Slater determinant, that, due to ionic term errors, produces a ground state with a qualitatively incorrect nodal surface when used in the absence of the Jastrow.« less

Increased expression of EZH2 in Merkel cell carcinoma is associated with disease progression and poorer prognosis.

PubMed

Harms, Kelly L; Chubb, Heather; Zhao, Lili; Fullen, Douglas R; Bichakjian, Christopher K; Johnson, Timothy M; Carskadon, Shannon; Palanisamy, Nallasivam; Harms, Paul W

2017-09-01

Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that affects tumorigenesis by epigenetic gene silencing. Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine carcinoma that has a high risk of disease progression with nodal and distant metastases. Here, we evaluated EZH2 expression by immunohistochemistry in a cohort of 85 MCC tumors (29 primary tumors, 41 lymph node metastases, 13 in-transit metastases, and 2 distant metastases) with clinical follow-up. We show strong/moderate EZH2 expression in 54% of tumors. Importantly, weak expression of EZH2 in the primary tumor, but not nodal metastases, correlated with improved prognosis compared to moderate/strong EZH2 expression (5-year MCC-specific survival of 68% versus 22%, respectively, P=.024). In addition, EZH2 was expressed at higher levels in nodal metastases compared to primary tumors (P=.005). Our data demonstrate that EZH2 has prognostic value and may play an oncogenic role in MCC. Copyright © 2017 Elsevier Inc. All rights reserved.

Symmetry-enforced stability of interacting Weyl and Dirac semimetals

NASA Astrophysics Data System (ADS)

Carlström, Johan; Bergholtz, Emil J.

2018-04-01

The nodal and effectively relativistic dispersion featuring in a range of novel materials including two-dimensional graphene and three-dimensional Dirac and Weyl semimetals has attracted enormous interest during the past decade. Here, by studying the structure and symmetry of the diagrammatic expansion, we show that these nodal touching points are in fact perturbatively stable to all orders with respect to generic two-body interactions. For effective low-energy theories relevant for single and multilayer graphene, type-I and type-II Weyl and Dirac semimetals, as well as Weyl points with higher topological charge, this stability is shown to be a direct consequence of a spatial symmetry that anticommutes with the effective Hamiltonian while leaving the interaction invariant. A more refined argument is applied to the honeycomb lattice model of graphene showing that its Dirac points are also perturbatively stable to all orders. We also give examples of nodal Hamiltonians that acquire a gap from interactions as a consequence of symmetries different from those of Weyl and Dirac materials.

Selective phonon damping in topological semimetals

NASA Astrophysics Data System (ADS)

Gordon, Jacob S.; Kee, Hae-Young

2018-05-01

Topological semimetals are characterized by their intriguing Fermi surfaces (FSs) such as Weyl and Dirac points, or nodal FS, and their associated surface states. Among them, topological crystalline semimetals, in the presence of strong spin-orbit coupling, possess a nodal FS protected by nonsymmorphic lattice symmetries. In particular, it was theoretically proposed that SrIrO3 exhibits a bulk nodal ring due to glide symmetries, as well as flat two-dimensional surface states related to chiral and mirror symmetries. However, due to the semimetallic nature of the bulk, direct observation of these surface states is difficult. Here we study the effect of flat-surface states on phonon modes for SrIrO3 side surfaces. We show that mirror odd optical surface phonon modes are damped at the zone center, as a result of coupling to the surface states with different mirror parities, while even modes are unaffected. This observation could be used to infer their existence, and experimental techniques for such measurements are also discussed.

Topologically nontrivial electronic states in CaSn3

NASA Astrophysics Data System (ADS)

Gupta, Sunny; Juneja, Rinkle; Shinde, Ravindra; Singh, Abhishek K.

2017-06-01

Based on the first-principles calculations, we theoretically propose topologically non-trivial states in a recently experimentally discovered superconducting material CaSn3. When the spin-orbit coupling (SOC) is ignored, the material is a host to three-dimensional topological nodal-line semimetal states. Drumhead like surface states protected by the coexistence of time-reversal and mirror symmetry emerge within the two-dimensional regions of the surface Brillouin zone connecting the nodal lines. When SOC is included, unexpectedly, each nodal line evolves into two Weyl nodes (W1 and W2) in this centrosymmetric material. Berry curvature calculations show that these nodes occur in a pair and act as either a source or a sink of Berry flux. This material also has unique surface states in the form of Fermi arcs, which unlike other known Weyl semimetals forms closed loops of surface states on the Fermi surface. Our theoretical realization of topologically non-trivial states in a superconducting material paves the way towards unraveling the interconnection between topological physics and superconductivity.

Dynamic characteristics of two new vibration modes of the disk-shell shaped gear

NASA Astrophysics Data System (ADS)

Yan, Litang; Qiu, Shijung; Gao, Xiangqung

1992-10-01

Two new vibration modes of the disk-shell-shaped big medium gears placed on three separate medium shafts of a turboprop engine have been found. They have the same nodal diameters as the conventional ones, but their frequencies are higher. The tooth ring vibrates both radially and axially and has greater deflection than the gear hub. The resonance of these two new nodal diameter modes is much more dangerous than that of the conventional nodal diameter modes. Moreover, they occur nearly at the upper and the lower bounds of the gear operating speed range. A special detuning method is developed for removing the resonance of these two new modes out of the upper and the lower bounds, respectively, and the effectiveness of the damping rings in this case has been researched. The vibration responses measured on the reductor casing have been then reduced to a quite low level after the damping rings were applied to the three big medium gears.

Concomitant Wolff-Parkinson-White and Atrioventricular Nodal Reentrant Tachycardia: Which Pathway to Ablate?

PubMed

Sarsam, Sinan; Sidiqi, Ibrahim; Shah, Dipak; Zughaib, Marcel

2015-12-11

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of supraventricular tachycardia. In contrast, Wolff-Parkinson-White (WPW) pattern consists of an accessory pathway, which may result in the development of ventricular arrhythmias. Frequent tachycardia caused by AVNRT and accessory pathways may play a role in left ventricular systolic dysfunction. A 54-year-old man presented with palpitations and acute decompensated congestive heart failure. His baseline EKG showed Wolff-Parkinson-White (WPW) pattern. While hospitalized, he had an episode of atrioventricular nodal reentrant tachycardia (AVNRT). He underwent radiofrequency catheter ablation for AVNRT, and his accessory pathway was also ablated even though its conduction was found to be weak. He was clinically doing well on follow-up visit, with resolution of his heart failure symptoms and normalization of left ventricular function on echocardiography. This case raises the question whether the accessory pathway plays a role in the development of systolic dysfunction, and if there is any role for ablation in patients with asymptomatic WPW pattern.

Clinical utilities and biological characteristics of melanoma sentinel lymph nodes

PubMed Central

Han, Dale; Thomas, Daniel C; Zager, Jonathan S; Pockaj, Barbara; White, Richard L; Leong, Stanley PL

2016-01-01

An estimated 73870 people will be diagnosed with melanoma in the United States in 2015, resulting in 9940 deaths. The majority of patients with cutaneous melanomas are cured with wide local excision. However, current evidence supports the use of sentinel lymph node biopsy (SLNB) given the 15%-20% of patients who harbor regional node metastasis. More importantly, the presence or absence of nodal micrometastases has been found to be the most important prognostic factor in early-stage melanoma, particularly in intermediate thickness melanoma. This review examines the development of SLNB for melanoma as a means to determine a patient’s nodal status, the efficacy of SLNB in patients with melanoma, and the biology of melanoma metastatic to sentinel lymph nodes. Prospective randomized trials have guided the development of practice guidelines for use of SLNB for melanoma and have shown the prognostic value of SLNB. Given the rapidly advancing molecular and surgical technologies, the technical aspects of diagnosis, identification, and management of regional lymph nodes in melanoma continues to evolve and to improve. Additionally, there is ongoing research examining both the role of SLNB for specific clinical scenarios and the ways to identify patients who may benefit from completion lymphadenectomy for a positive SLN. Until further data provides sufficient evidence to alter national consensus-based guidelines, SLNB with completion lymphadenectomy remains the standard of care for clinically node-negative patients found to have a positive SLN. PMID:27081640

Coupled 2D-3D finite element method for analysis of a skin panel with a discontinuous stiffener

NASA Technical Reports Server (NTRS)

Wang, J. T.; Lotts, C. G.; Davis, D. D., Jr.; Krishnamurthy, T.

1992-01-01

This paper describes a computationally efficient analysis method which was used to predict detailed stress states in a typical composite compression panel with a discontinuous hat stiffener. A global-local approach was used. The global model incorporated both 2D shell and 3D brick elements connected by newly developed transition elements. Most of the panel was modeled with 2D elements, while 3D elements were employed to model the stiffener flange and the adjacent skin. Both linear and geometrically nonlinear analyses were performed on the global model. The effect of geometric nonlinearity induced by the eccentric load path due to the discontinuous hat stiffener was significant. The local model used a fine mesh of 3D brick elements to model the region at the end of the stiffener. Boundary conditions of the local 3D model were obtained by spline interpolation of the nodal displacements from the global analysis. Detailed in-plane and through-the-thickness stresses were calculated in the flange-skin interface near the end of the stiffener.

A new approach to fluid-structure interaction within graphics hardware accelerated smooth particle hydrodynamics considering heterogeneous particle size distribution

NASA Astrophysics Data System (ADS)

Eghtesad, Adnan; Knezevic, Marko

2018-07-01

A corrective smooth particle method (CSPM) within smooth particle hydrodynamics (SPH) is used to study the deformation of an aircraft structure under high-velocity water-ditching impact load. The CSPM-SPH method features a new approach for the prediction of two-way fluid-structure interaction coupling. Results indicate that the implementation is well suited for modeling the deformation of structures under high-velocity impact into water as evident from the predicted stress and strain localizations in the aircraft structure as well as the integrity of the impacted interfaces, which show no artificial particle penetrations. To reduce the simulation time, a heterogeneous particle size distribution over a complex three-dimensional geometry is used. The variable particle size is achieved from a finite element mesh with variable element size and, as a result, variable nodal (i.e., SPH particle) spacing. To further accelerate the simulations, the SPH code is ported to a graphics processing unit using the OpenACC standard. The implementation and simulation results are described and discussed in this paper.

Transport Corrections in Nodal Diffusion Codes for HTR Modeling

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

Abderrafi M. Ougouag; Frederick N. Gleicher

2010-08-01

The cores and reflectors of High Temperature Reactors (HTRs) of the Next Generation Nuclear Plant (NGNP) type are dominantly diffusive media from the point of view of behavior of the neutrons and their migration between the various structures of the reactor. This means that neutron diffusion theory is sufficient for modeling most features of such reactors and transport theory may not be needed for most applications. Of course, the above statement assumes the availability of homogenized diffusion theory data. The statement is true for most situations but not all. Two features of NGNP-type HTRs require that the diffusion theory-based solutionmore » be corrected for local transport effects. These two cases are the treatment of burnable poisons (BP) in the case of the prismatic block reactors and, for both pebble bed reactor (PBR) and prismatic block reactor (PMR) designs, that of control rods (CR) embedded in non-multiplying regions near the interface between fueled zones and said non-multiplying zones. The need for transport correction arises because diffusion theory-based solutions appear not to provide sufficient fidelity in these situations.« less

A new approach to fluid-structure interaction within graphics hardware accelerated smooth particle hydrodynamics considering heterogeneous particle size distribution

NASA Astrophysics Data System (ADS)

Eghtesad, Adnan; Knezevic, Marko

2017-12-01

A corrective smooth particle method (CSPM) within smooth particle hydrodynamics (SPH) is used to study the deformation of an aircraft structure under high-velocity water-ditching impact load. The CSPM-SPH method features a new approach for the prediction of two-way fluid-structure interaction coupling. Results indicate that the implementation is well suited for modeling the deformation of structures under high-velocity impact into water as evident from the predicted stress and strain localizations in the aircraft structure as well as the integrity of the impacted interfaces, which show no artificial particle penetrations. To reduce the simulation time, a heterogeneous particle size distribution over a complex three-dimensional geometry is used. The variable particle size is achieved from a finite element mesh with variable element size and, as a result, variable nodal (i.e., SPH particle) spacing. To further accelerate the simulations, the SPH code is ported to a graphics processing unit using the OpenACC standard. The implementation and simulation results are described and discussed in this paper.

A Web-based nomogram predicting para-aortic nodal metastasis in incompletely staged patients with endometrial cancer: a Korean Multicenter Study.

PubMed

Kang, Sokbom; Lee, Jong-Min; Lee, Jae-Kwan; Kim, Jae-Weon; Cho, Chi-Heum; Kim, Seok-Mo; Park, Sang-Yoon; Park, Chan-Yong; Kim, Ki-Tae

2014-03-01

The purpose of this study is to develop a Web-based nomogram for predicting the individualized risk of para-aortic nodal metastasis in incompletely staged patients with endometrial cancer. From 8 institutions, the medical records of 397 patients who underwent pelvic and para-aortic lymphadenectomy as a surgical staging procedure were retrospectively reviewed. A multivariate logistic regression model was created and internally validated by rigorous bootstrap resampling methods. Finally, the model was transformed into a user-friendly Web-based nomogram (http://http://www.kgog.org/nomogram/empa001.html). The rate of para-aortic nodal metastasis was 14.4% (57/397 patients). Using a stepwise variable selection, 4 variables including deep myometrial invasion, non-endometrioid subtype, lymphovascular space invasion, and log-transformed CA-125 levels were finally adopted. After 1000 repetitions of bootstrapping, all of these 4 variables retained a significant association with para-aortic nodal metastasis in the multivariate analysis-deep myometrial invasion (P = 0.001), non-endometrioid histologic subtype (P = 0.034), lymphovascular space invasion (P = 0.003), and log-transformed serum CA-125 levels (P = 0.004). The model showed good discrimination (C statistics = 0.87; 95% confidence interval, 0.82-0.92) and accurate calibration (Hosmer-Lemeshow P = 0.74). This nomogram showed good performance in predicting para-aortic metastasis in patients with endometrial cancer. The tool may be useful in determining the extent of lymphadenectomy after incomplete surgery.

Correlation of Various Biomarkers with Axillary Nodal Metastases: Can a Panel of Such Biomarkers Guide Selective Use of Axillary Surgery in T1 Breast Cancer?

PubMed

Dass, Tufale A; Rakesh, Sharma; Prakash, K Patil; Singh, Chandraveer

2015-12-01

To evaluate the correlation of various clinic-pathological variables with axillary nodal involvement in T1 breast cancer & to identify a sub-group of T1 cancers, on the basis of observed variables, with a low risk of axillary nodal metastases. Clinico-pathological variables observed included tumor size, lymphovascular invasion (LVI), histological grade of tumor, tumor palpability, estrogen/progesterone (ER/PR) & her2/neu receptors, age, family history, histological type of tumor, axillary nodal metastases for 100 patients without clinically palpable nodes who underwent axillary lymph node dissection in Bombay Hospital & Medical Research Center from March, 2009. Data compiled was analyzed by univariate & multivariate analysis. All the variables viz. tumor size, LVI, histological grade, tumor palpability & ER/PR/Her2 receptor profile, which were found to be significantly associated with axillary lymph node involvement (ALNI) on univariate analysis were also found to be independent predictors of ALNI on multivariate analysis. Age of the patient, family history & histological type of tumor were not significantly correlated with ALNI. None of the 12 patients with tumor biomarker profile of T1a-b tumors without LVI & with histological grade I, had ALNI. The risk of ALNI can be predicted by using various tumor biomarker variables. Based on the predicted risk of ALNI, the management strategy for axilla can be individualized. The omission of operative axillary staging may be considered in patients with low predictive risk of ALNI.

The value of histological grading of biopsy and resection specimens in early stage oral squamous cell carcinomas.

PubMed

Dik, Eric A; Ipenburg, Norbertus A; Kessler, Peter A; van Es, Robert J J; Willems, Stefan M

2018-04-05

In oral squamous cell carcinoma (OSCC) the differentiation grade of the tumor is determined on the biopsy and the resection specimen. The relation between tumor grade, nodal metastasis and survival is debatable. The aims of this study were to determine the correlation between differentiation grade of the biopsy and the resection specimen. Furthermore, we wanted to correlate tumor differentiation grade with nodal stage and survival. One-hundred and forty-five patients with OSCC staged as T1-2, N0 of the tongue, floor of mouth or cheek with primary resection of the tumor were examined. Biopsy and resection specimen were histologically re-assessed with regard to differentiation grade, as well as infiltrative, peri-neural and vascular invasive growth. This study showed a poor correlation between differentiation grade in the incisional biopsy and the resection specimen of the same tumor. No significant relation between differentiation grade of the resection specimen and nodal involvement, as well as overall and disease-specific survival was found. In early OSCC the differentiation grade determined by biopsy is of little predictive value for the grading of the resection specimen. Poor differentiation grade could not be related to the presence of nodal metastasis or survival and seems not to have any prognostic value concerning outcome. Treatment planning must be related to these findings. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Long-term outcome of ultrasound-guided percutaneous ethanol ablation of selected "recurrent" neck nodal metastases in 25 patients with TNM stages III or IVA papillary thyroid carcinoma previously treated by surgery and 131I therapy.

PubMed

Hay, Ian D; Lee, Robert A; Davidge-Pitts, Caroline; Reading, Carl C; Charboneau, J William

2013-12-01

Ultrasound-guided percutaneous ethanol ablation (UPEA) of neck nodal metastases (NNM) has rarely been reported in papillary thyroid carcinoma (PTC) patients with advanced localized disease. We ablated 25 PTC patients with stage III or IVA disease (mean age 58 years) who had "recurrent" NNM after surgery and 131I therapy. Diagnosis of 37 selected NNM was proven by ultrasound-guided biopsy. UPEA was usually performed in 2 outpatient sessions. After UPEA, 35 of 37 NNM (95%) decreased in size. None had significant Doppler flow. Seventeen (46%) disappeared on rescanning. Serum thyroglobulin fell in 19 of 22 (86%) without thyroglobulin autoantibodies. None of the UPEA-treated NNM, followed on average for 5.4 years, required further intervention. Six patients (24%) subsequently developed 18 "new" recurrences. Of the 18, 15 (83%) were managed successfully by UPEA rather than operation. None of the 25 patients developed permanent hoarseness or have died from PTC. At our institution, where patients undergoing nodal dissections are charged $35-45,000, each outpatient UPEA procedure saves health providers approximately $38,400. Our 25 ablated patients, by avoiding 40 further neck reexplorations, on average, saved $61,440 in charges. UPEA for NNM in advanced localized PTC has proved safe and effective. It is also considerably less expensive than the conventional operative alternative of nodal dissection. Copyright © 2013 Mosby, Inc. All rights reserved.

Computer Three-Dimensional Reconstruction of the Atrioventricular Node

PubMed Central

Li, Jue; Greener, Ian D.; Inada, Shin; Nikolski, Vladimir P.; Yamamoto, Mitsuru; Hancox, Jules C.; Zhang, Henggui; Billeter, Rudi; Efimov, Igor R.; Dobrzynski, Halina; Boyett, Mark R.

2009-01-01

Because of its complexity, the atrioventricular node (AVN), remains 1 of the least understood regions of the heart. The aim of the study was to construct a detailed anatomic model of the AVN and relate it to AVN function. The electric activity of a rabbit AVN preparation was imaged using voltage-dependent dye. The preparation was then fixed and sectioned. Sixty-five sections at 60- to 340-μm intervals were stained for histology and immunolabeled for neurofilament (marker of nodal tissue) and connexin43 (gap junction protein). This revealed multiple structures within and around the AVN, including transitional tissue, inferior nodal extension, penetrating bundle, His bundle, atrial and ventricular muscle, central fibrous body, tendon of Todaro, and valves. A 3D anatomically detailed mathematical model (≈13 million element array) of the AVN and surrounding atrium and ventricle, incorporating all cell types, was constructed. Comparison of the model with electric activity recorded in experiments suggests that the inferior nodal extension forms the slow pathway, whereas the transitional tissue forms the fast pathway into the AVN. In addition, it suggests the pacemaker activity of the atrioventricular junction originates in the inferior nodal extension. Computer simulation of the propagation of the action potential through the anatomic model shows how, because of the complex structure of the AVN, reentry (slow-fast and fast-slow) can occur. In summary, a mathematical model of the anatomy of the AVN has been generated that allows AVN conduction to be explored. PMID:18309098

Discretisation Schemes for Level Sets of Planar Gaussian Fields

NASA Astrophysics Data System (ADS)

Beliaev, D.; Muirhead, S.

2018-01-01

Smooth random Gaussian functions play an important role in mathematical physics, a main example being the random plane wave model conjectured by Berry to give a universal description of high-energy eigenfunctions of the Laplacian on generic compact manifolds. Our work is motivated by questions about the geometry of such random functions, in particular relating to the structure of their nodal and level sets. We study four discretisation schemes that extract information about level sets of planar Gaussian fields. Each scheme recovers information up to a different level of precision, and each requires a maximum mesh-size in order to be valid with high probability. The first two schemes are generalisations and enhancements of similar schemes that have appeared in the literature (Beffara and Gayet in Publ Math IHES, 2017. https://doi.org/10.1007/s10240-017-0093-0; Mischaikow and Wanner in Ann Appl Probab 17:980-1018, 2007); these give complete topological information about the level sets on either a local or global scale. As an application, we improve the results in Beffara and Gayet (2017) on Russo-Seymour-Welsh estimates for the nodal set of positively-correlated planar Gaussian fields. The third and fourth schemes are, to the best of our knowledge, completely new. The third scheme is specific to the nodal set of the random plane wave, and provides global topological information about the nodal set up to `visible ambiguities'. The fourth scheme gives a way to approximate the mean number of excursion domains of planar Gaussian fields.

CHOEP-21 chemotherapy for newly diagnosed nodal peripheral T-cell lymphomas (PTCLs) in Maharaj Nakorn Chiang Mai Hospital.

PubMed

Rattarittamrong, Ekarat; Norasetthada, Lalita; Tantiworawit, Adisak; Chai-Adisaksopha, Chatree; Nawarawong, Weerasak

2013-11-01

To determine the effectiveness and tolerability of the combination of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) with the addition of etoposide (CHOEP-21) for newly diagnosed nodal peripheral T-cell lymphomas (PTCLs). Between January 2009 and October 2011, patients aged 18 to 60 years with newly diagnosed nodal PTCLs at the Maharaj Nakorn Chiang Mai Hospital were enrolled to receive CHOEP-21 every three weeks for eight cycles. G-CSF prophylaxis was given to all patients. Twenty-four patients were enrolled. Twenty of them were male with a median age of 49 years. The majority of patients (66.7%) had PTCL, not otherwise specified (PTCL, NOS), and 95.8% of the patients were in stage III or IV. The overall response rate was 58% with 42% having complete response. The response rates were better among patients with ALK-negative anaplastic large cell lymphoma (ALCL; 100%) and angioimmunoblastic T-cell lymphoma (AITL; 85%) than those with PTCL, NOS (44%). With a median follow-up of 21 months, the patients had an estimated 2-year event-free survival, and an overall survival rate of 37.6% and 54.4%, respectively. The most common adverse effects were infection and hematologic toxicities that was manageable. Although CHOEP-21 induced favorable responses in patients with ALK-negative ALCL and AITL, the responses were not durable and further therapy is mandated in management of patients with nodal PTCL.

Topological Alterations of the Intrinsic Brain Network in Patients with Functional Dyspepsia.

PubMed

Nan, Jiaofen; Zhang, Li; Zhu, Fubao; Tian, Xiaorui; Zheng, Qian; Deneen, Karen M von; Liu, Jixin; Zhang, Ming

2016-01-31

Previous studies reported that integrated information in the brain ultimately determines the subjective experience of patients with chronic pain, but how the information is integrated in the brain connectome of functional dyspepsia (FD) patients remains largely unclear. The study aimed to quantify the topological changes of the brain network in FD patients. Small-world properties, network efficiency and nodal centrality were utilized to measure the changes in topological architecture in 25 FD patients and 25 healthy controls based on functional magnetic resonance imaging. Pearson's correlation assessed the relationship of each topological property with clinical symptoms. FD patients showed an increase of clustering coefficients and local efficiency relative to controls from the perspective of a whole network as well as elevated nodal centrality in the right orbital part of the inferior frontal gyrus, left anterior cingulate gyrus and left hippocampus, and decreased nodal centrality in the right posterior cingulate gyrus, left cuneus, right putamen, left middle occipital gyrus and right inferior occipital gyrus. Moreover, the centrality in the anterior cingulate gyrus was significantly associated with symptom severity and duration in FD patients. Nevertheless, the inclusion of anxiety and depression scores as covariates erased the group differences in nodal centralities in the orbital part of the inferior frontal gyrus and hippocampus. The results suggest topological disruption of the functional brain networks in FD patients, presumably in response to disturbances of sensory information integrated with emotion, memory, pain modulation, and selective attention in patients.

Is elective nodal irradiation beneficial in patients with pathologically negative lymph nodes after neoadjuvant chemotherapy and breast-conserving surgery for clinical stage II-III breast cancer? A multicentre retrospective study (KROG 12-05).

PubMed

Noh, J M; Park, W; Suh, C-O; Keum, K C; Kim, Y B; Shin, K H; Kim, K; Chie, E K; Ha, S W; Kim, S S; Ahn, S D; Shin, H S; Kim, J H; Lee, H-S; Lee, N K; Huh, S J; Choi, D H

2014-03-18

To evaluate the effects of elective nodal irradiation (ENI) in clinical stage II-III breast cancer patients with pathologically negative lymph nodes (LNs) (ypN0) after neoadjuvant chemotherapy (NAC) followed by breast-conserving surgery (BCS) and radiotherapy (RT). We retrospectively analysed 260 patients with ypN0 who received NAC followed by BCS and RT. Elective nodal irradiation was delivered to 136 (52.3%) patients. The effects of ENI on survival outcomes were evaluated. After a median follow-up period of 66.2 months (range, 15.6-127.4 months), 26 patients (10.0%) developed disease recurrence. The 5-year locoregional recurrence-free survival and disease-free survival (DFS) for all patients were 95.5% and 90.5%, respectively. Pathologic T classification (0-is vs 1 vs 2-4) and the number of LNs sampled (<13 vs ≥13) were associated with DFS (P=0.0086 and 0.0012, respectively). There was no significant difference in survival outcomes according to ENI. Elective nodal irradiation also did not affect survival outcomes in any of the subgroups according to pathologic T classification or the number of LNs sampled. ENI may be omitted in patients with ypN0 breast cancer after NAC and BCS. But until the results of the randomised trials are available, patients should be put on these trials.

Involved field radiotherapy (IFRT) versus elective nodal irradiation (ENI) for locally advanced non-small cell lung cancer: a meta-analysis of incidence of elective nodal failure (ENF).

PubMed

Li, Ruijian; Yu, Liang; Lin, Sixiang; Wang, Lina; Dong, Xin; Yu, Lingxia; Li, Weiyi; Li, Baosheng

2016-09-21

The use of involved field radiotherapy (IFRT) has generated concern about the increasing incidence of elective nodal failure (ENF) in contrast to elective nodal irradiation (ENI). This meta-analysis aimed to provide more reliable and up-to-date evidence on the incidence of ENF between IFRT and ENI. We searched three databases for eligible studies where locally advanced non-small cell lung cancer (NSCLC) patients received IFRT or ENI. Outcome of interest was the incidence of ENF. The fixed-effects model was used to pool outcomes across the studies. There were 3 RCTs and 3 cohort studies included with low risk of bias. There was no significant difference in incidence of ENF between IFRT and ENI either among RCTs (RR = 1.38, 95 % CI: 0.59-3.25, p = 0.46) or among cohort studies (RR = 0.99, 95 % CI: 0.46-2.10, p = 0.97). There was also no significant difference in incidence of ENF between IFRT and ENI when RCTs and cohort studies were combined (RR = 1.15, 95 % CI: 0.65-2.01, p = 0.64). I 2 of test for heterogeneity was 0 %. This meta-analysis provides more reliable and stable evidence that there is no significant difference in incidence of ENF between IFRT and ENI.

Is elective nodal irradiation beneficial in patients with pathologically negative lymph nodes after neoadjuvant chemotherapy and breast-conserving surgery for clinical stage II–III breast cancer? A multicentre retrospective study (KROG 12-05)

PubMed Central

Noh, J M; Park, W; Suh, C-O; Keum, K C; Kim, Y B; Shin, K H; Kim, K; Chie, E K; Ha, S W; Kim, S S; Ahn, S D; Shin, H S; Kim, J H; Lee, H-S; Lee, N K; Huh, S J; Choi, D H

2014-01-01

Background: To evaluate the effects of elective nodal irradiation (ENI) in clinical stage II–III breast cancer patients with pathologically negative lymph nodes (LNs) (ypN0) after neoadjuvant chemotherapy (NAC) followed by breast-conserving surgery (BCS) and radiotherapy (RT). Methods: We retrospectively analysed 260 patients with ypN0 who received NAC followed by BCS and RT. Elective nodal irradiation was delivered to 136 (52.3%) patients. The effects of ENI on survival outcomes were evaluated. Results: After a median follow-up period of 66.2 months (range, 15.6–127.4 months), 26 patients (10.0%) developed disease recurrence. The 5-year locoregional recurrence-free survival and disease-free survival (DFS) for all patients were 95.5% and 90.5%, respectively. Pathologic T classification (0−is vs 1 vs 2–4) and the number of LNs sampled (<13 vs ⩾13) were associated with DFS (P=0.0086 and 0.0012, respectively). There was no significant difference in survival outcomes according to ENI. Elective nodal irradiation also did not affect survival outcomes in any of the subgroups according to pathologic T classification or the number of LNs sampled. Conclusions: ENI may be omitted in patients with ypN0 breast cancer after NAC and BCS. But until the results of the randomised trials are available, patients should be put on these trials. PMID:24481403

Elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for squamous cell carcinoma of the thoracic esophagus.

PubMed

Onozawa, Masakatsu; Nihei, Keiji; Ishikura, Satoshi; Minashi, Keiko; Yano, Tomonori; Muto, Manabu; Ohtsu, Atsushi; Ogino, Takashi

2009-08-01

There are some reports indicating that prophylactic three-field lymph node dissection for esophageal cancer can lead to improved survival. But the benefit of ENI in CRT for thoracic esophageal cancer remains controversial. The purpose of the present study is to retrospectively evaluate the efficacy of elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for thoracic esophageal cancer. Patients with squamous cell carcinoma (SCC) of the thoracic esophagus newly diagnosed between February 1999 and April 2001 in our institution was recruited from our database. Definitive chemoradiotherapy consisted of two cycles of cisplatin/5FU repeated every 5 weeks, with concurrent radiation therapy of 60 Gy in 30 fractions. Up to 40 Gy radiation therapy was delivered to the cervical, periesophageal, mediastinal and perigastric lymph nodes as ENI. One hundred two patients were included in this analysis, and their characteristics were as follows: median age, 65 years; male/female, 85/17; T1/T2/T3/T4, 16/11/61/14; N0/N1, 48/54; M0/M1, 84/18. The median follow-up period for the surviving patients was 41 months. Sixty patients achieved complete response (CR). After achieving CR, only one (1.0%; 95% CI, 0-5.3%) patient experienced elective nodal failure without any other site of recurrence. In CRT for esophageal SCC, ENI is effective for preventing regional nodal failure. Further evaluation of whether ENI leads to an improved overall survival is needed.

Nodal Lymphangiogenesis and Metastasis

PubMed Central

Hirakawa, Satoshi; Detmar, Michael; Kerjaschki, Dontscho; Nagamatsu, Shogo; Matsuo, Keitaro; Tanemura, Atsushi; Kamata, Nobuyuki; Higashikawa, Koichiro; Okazaki, Hidenori; Kameda, Kenji; Nishida-Fukuda, Hisayo; Mori, Hideki; Hanakawa, Yasushi; Sayama, Koji; Shirakata, Yuji; Tohyama, Mikiko; Tokumaru, Sho; Katayama, Ichiro; Hashimoto, Koji

2009-01-01

Nodal lymphangiogenesis promotes distant lymph node (LN) metastasis in experimental cancer models. However, the role of nodal lymphangiogenesis in distant metastasis and in the overall survival of cancer patients remains unknown. Therefore, we investigated mechanisms that might facilitate regional and distant LN metastasis in extramammary Paget’s disease (EMPD). We retrospectively analyzed the impact of tumor-induced lymphatic vessel activation on the survival of 116 patients, the largest cohort with EMPD studied to date. Nodal lymphangiogenesis was significantly increased in metastatic, compared with tumor-free, LNs (P = 0.022). Increased lymphatic invasion within regional LNs was significantly associated with distant metastasis in LN (P = 0.047) and organs (P = 0.003). Thus, invasion within regional LNs is a powerful indicator of systemic tumor spread and reduced patient survival in EMPD (P = 0.0004). Lymphatic vessels associated with tumors expressed stromal cell-derived factor-1 (SDF-1), whereas CXCR4 was expressed on invasive Paget cells undergoing epithelial-mesenchymal transition (EMT)-like process. A431 cells overexpressing Snail expressed increased levels of CXCR4 in the presence of transforming growth factor-β1. Haptotactic migration assays confirmed that Snail-induced EMT-like process promotes tumor cell motility via the CXCR4-SDF-1 axis. Sinusoidal lymphatic endothelial cells and macrophages expressed SDF-1 in subcapsular sinuses of lymph nodes before Paget cell arrival. Our findings reveal that EMT-related features likely promote lymphatic metastasis of EMPD by activating the CXCR4-SDF-1 axis. PMID:19815713

DTK C/Fortran Interface Development for NEAMS FSI Simulations

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

Slattery, Stuart R.; Lebrun-Grandie, Damien T.

This report documents the development of DataTransferKit (DTK) C and Fortran interfaces for fluid-structure-interaction (FSI) simulations in NEAMS. In these simulations, the codes Nek5000 and Diablo are being coupled within the SHARP framework to study flow-induced vibration (FIV) in reactor steam generators. We will review the current Nek5000/Diablo coupling algorithm in SHARP and the current state of the solution transfer scheme used in this implementation. We will then present existing DTK algorithms which may be used instead to provide an improvement in both flexibility and scalability of the current SHARP implementation. We will show how these can be used withinmore » the current FSI scheme using a new set of interfaces to the algorithms developed by this work. These new interfaces currently expose the mesh-free solution transfer algorithms in DTK, a C++ library, and are written in C and Fortran to enable coupling of both Nek5000 and Diablo in their native Fortran language. They have been compiled and tested on Cooley, the test-bed machine for Mira at ALCF.« less

Surface currents on the plasma-vacuum interface in MHD equilibria

NASA Astrophysics Data System (ADS)

Hanson, James

2017-10-01

The VMEC non-axisymmetric MHD equilibrium code can compute free-boundary equilibria. Since VMEC assumes that magnetic fields within the plasma form closed and nested flux surfaces, the plasma-vacuum interface is a flux surface, and the total magnetic field there has no normal component. VMEC imposes this condition of zero normal field using the potential formulation of Merkel, and solves a Neumann problem for the magnetic potential in the exterior region. This boundary condition necessarily admits the possibility of a surface current on the interface. While this surface current may be small in MHD equilibrium, it is readily computed in terms of the magnetic potentials in both the interior and exterior regions, evaluated on the surface. If only the external magnetic potential is known (as in VMEC), then the surface current can be computed from the discontinuity of the tangential field across the interface. Examples of the surface current for VMEC equilibria will be shown for a zero-pressure stellarator equilibrium. Field-line following of the vacuum magnetic field shows magnetic islands within the plasma region.

Optimization and performance comparison for galloping-based piezoelectric energy harvesters with alternating-current and direct-current interface circuits

NASA Astrophysics Data System (ADS)

Tan, Ting; Yan, Zhimiao; Lei, Hong

2017-07-01

Galloping-based piezoelectric energy harvesters scavenge small-scale wind energy and convert it into electrical energy. For piezoelectric energy harvesting with the same vibrational source (galloping) but different (alternating-current (AC) and direct-current (DC)) interfaces, general analytical solutions of the electromechanical coupled distributed parameter model are proposed. Galloping is theoretically proven to appear when the linear aerodynamic negative damping overcomes the electrical damping and mechanical damping. The harvested power is demonstrated as being done by the electrical damping force. Via tuning the load resistance to its optimal value for optimal or maximal electrical damping, the harvested power of the given structure with the AC/DC interface is maximized. The optimal load resistances and the corresponding performances of such two systems are compared. The optimal electrical damping are the same but with different optimal load resistances for the systems with the AC and DC interfaces. At small wind speeds where the optimal electrical damping can be realized by only tuning the load resistance, the performances of such two energy harvesting systems, including the minimal onset speeds to galloping, maximal harvested powers and corresponding tip displacements are almost the same. Smaller maximal electrical damping with larger optimal load resistance is found for the harvester with the DC interface when compared to those for the harvester with the AC interface. At large wind speeds when the maximal electrical damping rather than the optimal electrical damping can be reached by tuning the load resistance alone, the harvester with the AC interface circuit is recommended for a higher maximal harvested power with a smaller tip displacement. This study provides a method using the general electrical damping to connect and compare the performances of piezoelectric energy harvesters with same excitation source but different interfaces.

Unidirectional oxide hetero-interface thin-film diode

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

Park, Youngmin; Lee, Eungkyu; Lee, Jinwon

2015-10-05

The unidirectional thin-film diode based on oxide hetero-interface, which is well compatible with conventional thin-film fabrication process, is presented. With the metal anode/electron-transporting oxide (ETO)/electron-injecting oxide (EIO)/metal cathode structure, it exhibits that electrical currents ohmically flow at the ETO/EIO hetero-interfaces for only positive voltages showing current density (J)-rectifying ratio of ∼10{sup 5} at 5 V. The electrical properties (ex, current levels, and working device yields) of the thin-film diode (TFD) are systematically controlled by changing oxide layer thickness. Moreover, we show that the oxide hetero-interface TFD clearly rectifies an AC input within frequency (f) range of 10{sup 2} Hz < f < 10{sup 6} Hz, providing amore » high feasibility for practical applications.« less

Behavior of oxide film at the interface between particles in sintered Al powders by pulse electric-current sintering

NASA Astrophysics Data System (ADS)

Xie, Guoqiang; Ohashi, Osamu; Song, Minghui; Furuya, Kazuo; Noda, Tetsuji

2003-03-01

The microstructure of the bonding interfaces between particles in aluminum (Al) powder sintered specimens by the pulse electric-current sintering (PECS) process was observed, using conventional transmission electron microscopy (CTEM) and high-resolution transmission electron microscopy (HRTEM). The behavior of oxide film at the interface between Al particles and its effect on properties of the sintered specimens were investigated. The results showed there were two kinds of bonding interfaces in the sintered specimens, namely, the direct metal/metal bonding and the metal/oxide film layer/metal bonding interface. By increasing the fraction of the direct metal/metal bonding interfaces, the tensile strength of the sintered specimens increased, and the electrical resistivity decreased. By increasing the loading pressure at higher sintering temperatures or increasing the sintering temperature under loading pressure, the breakdown of oxide film was promoted. The broken oxide film debris was dispersed in aluminum metal near the bonding interfaces between particles.