Asialoglycoprotein-receptor-targeted hepatocyte imaging using {sup 99m}Tc galactosylated chitosan

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-Mi [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Jeong, Hwan-Jeong [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of)]. E-mail: jayjeong@chonbuk.ac.kr; Kim, Se-Lim [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Sohn, Myung-Hee [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Nah, Jae-Woon [Division of Applied Materials Engineering, Department of Polymer Science and Engineering, Sunchon National University, Sunchon, Jeonnam (Korea, Republic of); Bom, Hee-Seung [Department of Nuclear Medicine, Chonnam National University School of Medicine, Gwangju (Korea, Republic of); Park, In-Kyu [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of); Cho, Chong-Su [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of)

2006-05-15

This study investigated the usefulness of {sup 99m}Tc hydrazinonicotinamide-galactosylated chitosan (HGC) in hepatocyte imaging. HGC was obtained by coupling the galactose moiety of both lactobionic acid and succinimidyl 6-hydrazinonicotinate hydrochloride (succinimidyl HYNIC). The coupled product was then radiolabeled with {sup 99m}Tc using stannous chloride and tricine as reducing agent and coligand, respectively. Labeling efficiency was >90% both in room temperature and in serum up to 24 h after injection. The hepatic uptake properties of {sup 99m}Tc HGC were studied in Balb/C mice. {sup 99m}Tc HGC and {sup 99m}Tc hydrazinonicotinamide chitosan (HC) were intravenously injected into mice, with receptor binding identified by coinjection with 9 and 14 mg of free galactose. Images were acquired with a {gamma}-camera. After injection via the tail vein of the mice, {sup 99m}Tc HGC showed high selectivity for the liver, while {sup 99m}Tc HC without a galactose group showed low liver uptake. In addition, the hepatic uptake of {sup 99m}Tc HGC was blocked by coinjection of free galactose. Tissue distribution was determined at three different times (10, 60 and 120 min). The liver accumulated 13.16{+-}2.72%, 16.11{+-}5.70% and 16.55{+-}2.28% of the injected dose per gram at 10, 60 and 120 min after injection, respectively. {sup 99m}Tc HGC showed specific and rapid targeting of hepatocytes. It is a promising receptor-specific radiopharmaceutical with potential applications in liver imaging for the evaluation of hepatocytic function.

In vitro studies of leukocyte labeling with /sup 99m/Tc

International Nuclear Information System (INIS)

Uchida, T.; Vincent, P.C.

1976-01-01

A method for labeling leukocytes in vitro with /sup 99m/Tc is described. Separated leukocytes are incubated with /sup 99m/Tc, followed by reduction with stannous chloride and washing with acid citrate dextrose solution. Maximum labeling occurs after at least 5 min incubation with pertechnetate, followed by at least 10 min incubation with stannous chloride. Labeling is similar at room temperature and at 37 0 C. The labeled leukocytes are viable, and reutilization of label does not occur in vitro. In acid conditions (pH 5.2), the elution of /sup 99m/Tc from leukocytes is comparable with that of 32 P-diisopropylfluorophosphate, but /sup 99m/Tc elution is greater at pH 7.2 to 7.4. Neutrophils label more heavily with /sup 99m/Tc than do monocytes, lymphocytes, erythrocytes, or platelets

Expression of mtc in Folsomia candida indicative of metal pollution in soil

International Nuclear Information System (INIS)

Nota, Benjamin; Vooijs, Riet; Straalen, Nico M. van; Roelofs, Dick

2011-01-01

The soil-living springtail Folsomia candida is frequently used in reproduction bioassays to assess soil contamination. Alternatively, the response of genes to contamination is assessed. In this study the expression of F. candida's gene encoding the deduced metallothionein-like motif containing protein (MTC) was assessed, using quantitative PCR, in response to six different metals, each at two concentrations in soil. The expression of mtc was induced after exposure to all metals, except for one chromium concentration. Exposure to soil originating from metal-contaminated field sites also induced mtc, while the expression did not change in response to a polycyclic aromatic hydrocarbon. Since this transcript is induced by most of the tested metals, it may potentially be a good indicator of metal contamination. The presented gene expression assay might become a useful tool to screen potentially polluted sites, in order to identify the ones that need further ecotoxicological investigation. - Highlights: → mtc expression in the springtail Folsomia candida is measured in response to different metals. → Expression of this gene changed in response to all tested metals, except for one. → Metal-contaminated field soils also changed the expression of mtc significantly. → The polycyclic aromatic hydrocarbon phenanthrene did not change mtc's expression. → mtc expression may be a specific indicator of metal soil contamination. - Exposure to metal containing soil induces the expression of mtc in the springtail Folsomia candida.

Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

Science.gov (United States)

Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

2015-01-01

This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo.

Development of 99Mo/99mTc Generator System for Production of Medical Radionuclide 99mTc using a Neutron-activated 99Mo and Zirconium Based Material (ZBM as its Adsorbent

Directory of Open Access Journals (Sweden)

I. Saptiama

2016-12-01

Full Text Available Molybdenum produced from fission of U-235 is the most desirable precursor for 99Mo/99mTc generator system as it is non-carrier added and has high specific activity. However, in the last decade there has been short supply of 99Mo due to several constrains. Therefore, there have been many works performed for development of 99Mo/99mTc generator system using 99Mo which is not produced from either LEU or HEU. This report deals with development of 99Mo/99mTc generator system where zirconium-based material (ZBM is used as adsorbent of neutron-activated 99Mo. The system was prepared by firstly irradiating natural Mo in the G. A. Siwabessy reactor to produce neutron-activated 99Mo. The target was dissolved in NaOH 4N and then neutralized with 12 M HCl. The 99Mo solution was then mixed with a certain amount of ZBM followed by heating at 90°C for three hours to allow the 99Mo adsorbed on ZBM. The 99Mo-ZBM (9.36 GBq of 99Mo was Mo/ 4.2 g ZBM was packed on a fritz-glass column. This column was then fitted serially with an alumina column for trapping 99Mo breakthrough. The columns were then eluted daily with saline solution for up to one week. The yield of 99mTc was found to be between 53.7 – 74% (n= 5. All 99mTc eluates were clear solutions with pH of 5. Breakthrough of 99Mo in 99mTc eluates was found to be 0.031 ± 0.019 μCi 99Mo/ mCi 99mTc (n= 5 which was less than the maximum activity of 99Mo allowed in 99mTc solution ( 99%. Radiolabeling of this 99mTc towards methylene diphosphonate (MDP kit gave a radiolabelling efficiency of 99%. In summary, a new 99Mo/99mTc generator system that used neutron-activated 99Mo and ZBM as its adsorbent has been successfully prepared. The 99mTc produced from this new 99Mo/99mTc generator system attained the quality of 99mTc required for medical purposes.

Bioaccumulation and distribution of /sup 95m/Tc in an experimental freshwater pond

International Nuclear Information System (INIS)

Blaylock, B.G.; Frank, M.L.

1981-01-01

An acute release of /sup 95m/Tc was made to a small experimental freshwater pond to determine the behavior of technetium in a freshwater ecosystem. The objectives of the study were (1) to determine the distribution of /sup 95m/Tc in the components of the ecosystem and (2) to determine the concentration in freshwater biota. Prior to the release of /sup 95m/Tc, the pond was stocked with aquatic macrophytes, fish, and invertebrates. All components of the pond were sampled for a period of 37 d. Analyses of filtered and unfiltered water samples showed that /sup 95m/Tc did not sorb significantly to particulates suspended in the water but remained dissolved. Sediments accumulated /sup 95m/Tc slowly as the experiment progressed. In the biota, periphyton accumulated /sup 95m/Tc rapidly, reaching the highest concentration (3482 dpm/g dry wt) 4 h after the release and maintaining a relatively high concentration throughout the experiment. Fish and invertebrates accumulated /sup 95m/Tc gradually. Elimination studies and tissue analyses showed that a large percentage of the body burden was in the digestive system of all fish, suggesting that fish were accumulating /sup 95m/Tc through the food chain. Biological half-lives determined from elimination studies for carp (Cyprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 2.5, 4.3, and 21.3 d, respectively. Calculated concentration factors for the same species were 11 for carp, 75 for mosquito fish, and 121 for snails. The estimated size of the biomass components in the ecosystem in descending order were: periphyton, macrophytes, invertebrates, fish, and algae. Based on biomass estimates and concentrations of the /sup 95m/Tc in the aquatic biota, approximately 1% of the /sup 95m/Tc accumulated in the biota

Sup(99m)Tc compounds for diagnostic purposes

International Nuclear Information System (INIS)

Cifka, J.; Budsky, F.

1980-01-01

The applications of sup(99m)Tc in nuclear medicine are discussed, such as sodium pertechnetate in thyroid and brain scintigraphy, complex compounds in lungs and liver diao.nosis. Technetium generators are classified according to the method of separating sup(99m)Tc from 99 Mo. Adsorption generators are used, molybdate-99 is adsorbed on an Al 2 O 3 -packed column while pertechnetate-99m is eluted with 0.9% NaCl solution. Also used is continuous pertechnetate-99m extraction with methyl ethyl ketone from 0.5 M potassium molybdate and 2.5 M of potassium carbonate. The manufacture is described of kits for sup(99m)Tc radiopharmaceuticals preparation, eg., Diagos I, a gluconate complex, a lyophilisate for sup(99m)Tc-sodium pyrophosphate injections, a diagnostic kit for lung scintiscanning. (H.S.)

Transport of /sup 99m/Tc complexes through the blood-brain barrier

International Nuclear Information System (INIS)

Loberg, M.D.; Corder, E.H.; Fields, A.T.; Callery, P.S.

1979-01-01

Thirteen /sup 99m/Tc complexes have been synthesized and used to determine the relationships between protein binding, lipophilicity and membrane transport. The lipophilicity of the /sup 99m/Tc complexes was altered by adding substituents to either IDA, EDTA, DTPA or oxine; membrane transport was estimated using the brain uptake index (BUI) method. The BUI of the /sup 99m/Tc complexes was found to vary directly with lipophilicity and inversely with protein binding. These results demonstrated that /sup 99m/Tc-oxine derivatives are better suited for use in the development of intracellular tracers than are the /sup 99m/Tc derivatives of aminopolycarboxylates

Twisted network programming essentials

CERN Document Server

Fettig, Abe

2005-01-01

Twisted Network Programming Essentials from O'Reilly is a task-oriented look at this new open source, Python-based technology. The book begins with recommendations for various plug-ins and add-ons to enhance the basic package as installed. It then details Twisted's collection simple network protocols, and helper utilities. The book also includes projects that let you try out the Twisted framework for yourself. For example, you'll find examples of using Twisted to build web services applications using the REST architecture, using XML-RPC, and using SOAP. Written for developers who want to s

The Clinical usefulness of {sup 99mT}c HMPAO Leukocyte/{sup 99mT}c phytate bone marrow scintigraphy for diagnosis of prosthetic knee infection: A preliminary study

Energy Technology Data Exchange (ETDEWEB)

Jung, Kyung Pyo; Park, Ji Sun; Lee, Ah Young; Choi, Su Jung; Lee, Seok Mo; Bae, Sang Kyun [Inje Univ., Pusan Paik Hospital, Pusan (Korea, Republic of)

2012-12-15

The preferred radionuclide imaging procedure for diagnosing prosthetic joint infection is combined radiolabeled leukocyte/{sup 99mT}c sulfur colloid bone marrow scintigraphy, which has an accuracy of over 90%. Unfortunately, sulfur colloid is no longer available in South Korea. in this study, we evaluated the usefulness of {sup 99mT}c phytate, a substitute for {sup 99mT}c sulfur colloid, when combined with radiolabeled leukocyte scintigraphy in suspected prosthetic knee infections. Eleven patients (nine women, two men; mean age 72{+-}6 years) with painful knee prostheses and a suspicion of infection underwent both {sup 99mT}c phytate bone marrow scintigraphy (BMS). The combined images were interpreted as positive for infection when radioactivity in the LS at the sits of clinical interest clearly exceeded that of the BMS (discordant); they were interpreted as negative when the increased activity in the LS was consistent with an increased activity in the BMS(concordant). The final diagnosis was made with microbiological or intraoperative findings and a clinical follow up of at least 12 months. Five of eleven patients were diagnosed as having an infected prosthesis. The overall sensitivity, specificity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the combined LS/BMS were 100%, 83%, 83%, 100% and 91%, respectively. We find that combined {sup 99mT}c HMPAO LS/{sup 99mT}c phytate BMS shows comparable diagnostic performance to other studies utilizing sulfur colloid. Combined {sup 99mT}c HMPAO LS/{sup 99mT}c phytate BMS is therefore expected to be an acceptable alternative to combined radiolabeled LS/{sup 99ms}ulfur colloid BMS for diagnosing prosthetic knee infections.

93Tc and sup(93m)Tc gamma spectra

International Nuclear Information System (INIS)

Podkopaev, Yu.N.; Zarubin, P.P.; Kobelev, V.F.; Padalko, V.Yu.; Khrisanfov, Yu.V.

1977-01-01

The sup(93,93m)Tc decay was studied. The spectra of γ-rays accompanying the decay of this nuclide were studied. 93 Tc and sup(93m)Tc were obtained in the (dn)-reaction on 92 Mo. To ensure a more reliable identification of γ-rays, the isotopic composition of the targets, the bombardment time, the energy of the bombarding deuterons (5-12 MeV) and the spectrum processing program were varied. The energies and relative intensities of the γ-rays of the 93 Tc and sup(93m)Tc decay are listed in tables together with data of other investigatxons. The results obtained largely confirm the known data. Four new transitions were added in the sup(93m)Tc spectrum namely 1046.8, 2011.8, 2182.0, and 2861.5 keV. The 2739.0 keV transition was eliminated from the 93 Tc spectrum. The appropriate changes and additions were made in the 93 Tc decay scheme, and three new levels were introduced: 2479.0, 2821.7, and 3025.8 keV. The values of log ft of some levels of 93 Tc were estimated

Twisted classical Poincare algebras

International Nuclear Information System (INIS)

Lukierski, J.; Ruegg, H.; Tolstoy, V.N.; Nowicki, A.

1993-11-01

We consider the twisting of Hopf structure for classical enveloping algebra U(g), where g is the inhomogeneous rotations algebra, with explicite formulae given for D=4 Poincare algebra (g=P 4 ). The comultiplications of twisted U F (P 4 ) are obtained by conjugating primitive classical coproducts by F element of U(c)xU(c), where c denotes any Abelian subalgebra of P 4 , and the universal R-matrices for U F (P 4 ) are triangular. As an example we show that the quantum deformation of Poincare algebra recently proposed by Chaichian and Demiczev is a twisted classical Poincare algebra. The interpretation of twisted Poincare algebra as describing relativistic symmetries with clustered 2-particle states is proposed. (orig.)

Dose calibrator linearity test: {sup 99m}Tc versus {sup 18}F radioisotopes

Energy Technology Data Exchange (ETDEWEB)

Willegaignon, Jose; Coura-Filho, George Barberio; Garcez, Alexandre Teles, E-mail: willegaignon@hotmail.com [Instituto do Cancer do Estado de Sao Paulo Octavio Frias de Oliveira (ICESP), Sao Paulo, SP (Brazil); Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Fac. de Medicina; Alves, Carlos Eduardo Gonzalez Ribeiro; Cardona, Marissa Anabel Rivera; Gutterres, Ricardo Fraga [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2015-01-15

Objective: the present study was aimed at evaluating the viability of replacing {sup 18}F with {sup 99m}Tc in dose calibrator linearity testing. Materials and methods: the test was performed with sources of {sup 99m}Tc (62 GBq) and {sup 18}F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical {sup 99m}Tc and {sup 18}F sources activities were calculated and subsequently compared. Results: mean deviations between experimental and theoretical {sup 99m}Tc and {sup 18}F sources activities were 0.56 (± 1.79)% and 0.92 (± 1.19)%, respectively. The mean ratio between activities indicated by the device for the {sup 99m}Tc source as measured with the equipment precalibrated to measure {sup 99m}Tc and {sup 18}F was 3.42 (± 0.06), and for the {sup 18}F source this ratio was 3.39 (± 0.05), values considered constant over the measurement time. Conclusion: the results of the linearity test using {sup 99m}Tc were compatible with those obtained with the {sup 18}F source, indicating the viability of utilizing both radioisotopes in dose calibrator linearity testing. Such information in association with the high potential of radiation exposure and costs involved in {sup 18}F acquisition suggest {sup 99m}Tc as the element of choice to perform dose calibrator linearity tests in centers that use {sup 18}F, without any detriment to the procedure as well as to the quality of the nuclear medicine service. (author)

Generalised twisted partition functions

CERN Document Server

Petkova, V B

2001-01-01

We consider the set of partition functions that result from the insertion of twist operators compatible with conformal invariance in a given 2D Conformal Field Theory (CFT). A consistency equation, which gives a classification of twists, is written and solved in particular cases. This generalises old results on twisted torus boundary conditions, gives a physical interpretation of Ocneanu's algebraic construction, and might offer a new route to the study of properties of CFT.

Studies of techniques for the post-elution concentration of 99mTc obtained from gel type 99Mo/99mTc generators

International Nuclear Information System (INIS)

Suzuki, Katia Noriko

2009-01-01

On average 80% of the radiopharmaceuticals used in Nuclear Medicine are labeled with 99 mTc due to its physical properties and easy attainment through of 99 Mo/ 99 mTc generators. The Directory of Radiopharmacy (DIRF) of IPEN-CNEN/SP developed a gel type chromatographic generator of MoZr with 99 Mo produced by 98 Mo(n,γ) 99 Mo reaction that occurs at the IEA-R1 Nuclear Reactor. The gel is composed of zirconium molybdate with elution volume of 12 mL with an activity of 11100 MBq (300 mCi) producing a radioactive concentration of 925 MBq (25 mCi)/mL. The fission generator gives a higher radioactive concentration around 1850 MBq (50 mCi)/mL. The aim of this work is to study a system of post-elution concentration of 99 mTc for the attainment of a high enough radioactive concentration to meet the demands of the market, with a proved quality. Two types of systems of post-elution concentration were developed: the single and the tandem. The most appropriate system for the gel generator of 99 Mo/ 99 mTc, being at the same time sterile and vacuum automated, was the tandem system using Dionex 2.5 cc/QMA cartridges. The gel generator is eluted with 10 mL of solution of 0.1% NaCl and the pertechnetate anion is retained in the QMA cartridge and further eluted with 4 mL of saline. The process takes no more than 30 minutes. The elution efficiency of the system of concentration was 90 %. At the beginning of 2009 a global crisis in the supply of 99 Mo took place making it necessary the development of alternative technologies for the production of 99 Mo/ 99 mTc generators using fission produced 99 Mo and the development of an appropriate method to extend the useful life of this generator. The results of this study showed that the same system developed for the post- concentration of the gel generator can be employed for the fission generator, using the tandem system, giving a concentration factor of 3 for the elution of 99 mTc. (author)

`Twisted' electrons

Science.gov (United States)

Larocque, Hugo; Kaminer, Ido; Grillo, Vincenzo; Leuchs, Gerd; Padgett, Miles J.; Boyd, Robert W.; Segev, Mordechai; Karimi, Ebrahim

2018-04-01

Electrons have played a significant role in the development of many fields of physics during the last century. The interest surrounding them mostly involved their wave-like features prescribed by the quantum theory. In particular, these features correctly predict the behaviour of electrons in various physical systems including atoms, molecules, solid-state materials, and even in free space. Ten years ago, new breakthroughs were made, arising from the new ability to bestow orbital angular momentum (OAM) to the wave function of electrons. This quantity, in conjunction with the electron's charge, results in an additional magnetic property. Owing to these features, OAM-carrying, or twisted, electrons can effectively interact with magnetic fields in unprecedented ways and have motivated materials scientists to find new methods for generating twisted electrons and measuring their OAM content. Here, we provide an overview of such techniques along with an introduction to the exciting dynamics of twisted electrons.

Separation of sup(99m)Tc from 99MoO3

International Nuclear Information System (INIS)

Tomicic, M.

1977-07-01

At the present time sup(99m)Tc is widely used in nuclear medicine and its uses are increasing. It can be produced by various methods, and of those most frequently used today two have special features making them particularly applicable to the large-scale production of instant sup(99m)Tc - these are solvent extraction with methyl-ethyl-ketone and the sublimation methods. This report presents a bibliographic review of these methods, their main perfomance parameters, and experience obtained from the development and operation of a sublimation generator. Separation of sup(99m)Tc from irradiated MoO 3 was carried out with high yields (75-95%) after multiple repetition of the separation process with molybdenum trioxide heated for half an hour at a maximum temperature of 850-890 deg C in an air flow. The activity ratio of molybdenum in the separated sup(99m)Tc was of the order of 4 x 10 -5 . (author)

Practical flow cytometry

National Research Council Canada - National Science Library

Shapiro, Howard M

2003-01-01

... ... Conflict: Resolution ... 1.3 Problem Number One: Finding The Cell(s) ... Flow Cytometry: Quick on the Trigger ... The Main Event ... The Pulse Quickens, the Plot Thickens ... 1.4 Flow Cytometry: ...

Twist-stretch profiles of DNA chains

Science.gov (United States)

Zoli, Marco

2017-06-01

Helical molecules change their twist number under the effect of a mechanical load. We study the twist-stretch relation for a set of short DNA molecules modeled by a mesoscopic Hamiltonian. Finite temperature path integral techniques are applied to generate a large ensemble of possible configurations for the base pairs of the sequence. The model also accounts for the bending and twisting fluctuations between adjacent base pairs along the molecules stack. Simulating a broad range of twisting conformation, we compute the helix structural parameters by averaging over the ensemble of base pairs configurations. The method selects, for any applied force, the average twist angle which minimizes the molecule’s free energy. It is found that the chains generally over-twist under an applied stretching and the over-twisting is physically associated to the contraction of the average helix diameter, i.e. to the damping of the base pair fluctuations. Instead, assuming that the maximum amplitude of the bending fluctuations may decrease against the external load, the DNA molecule first over-twists for weak applied forces and then untwists above a characteristic force value. Our results are discussed in relation to available experimental information albeit for kilo-base long molecules.

Noncommutative geometry and twisted conformal symmetry

International Nuclear Information System (INIS)

Matlock, Peter

2005-01-01

The twist-deformed conformal algebra is constructed as a Hopf algebra with twisted coproduct. This allows for the definition of conformal symmetry in a noncommutative background geometry. The twisted coproduct is reviewed for the Poincare algebra and the construction is then extended to the full conformal algebra. The case of Moyal-type noncommutativity of the coordinates is considered. It is demonstrated that conformal invariance need not be viewed as incompatible with noncommutative geometry; the noncommutativity of the coordinates appears as a consequence of the twisting, as has been shown in the literature in the case of the twisted Poincare algebra

TEK twisted gradient flow running coupling

CERN Document Server

Pérez, Margarita García; Keegan, Liam; Okawa, Masanori

2014-01-01

We measure the running of the twisted gradient flow coupling in the Twisted Eguchi-Kawai (TEK) model, the SU(N) gauge theory on a single site lattice with twisted boundary conditions in the large N limit.

On the twist-2 and twist-3 contributions to the spin-dependent electroweak structure functions

International Nuclear Information System (INIS)

Bluemlein, J.; Kochelev, N.

1997-01-01

The twist-2 and twist-3 contributions of the polarized deep-inelastic structure functions are calculated both for neutral and charged current interactions using the operator product expansion in lowest order in QCD. The relations between the different structure functions are determined. New integral relations are derived between the twist-2 contributions of the structure functions g 3 (x,Q 2 ) and g 5 (x,Q 2 ) and between combinations of the twist-3 contributions to the structure functions g 2 (x,Q 2 ) and g 3 (x,Q 2 ). The sum rules for polarized deep-inelastic scattering are discussed in detail. (orig.)

Twisted rudder for reducing fuel-oil consumption

Directory of Open Access Journals (Sweden)

Jung-Hun Kim

2014-09-01

Full Text Available Three twisted rudders fit for large container ships have been developed; 1 the Z-twisted rudder that is an asymmetry type taking into consideration incoming flow angles of the propeller slipstream, 2 the ZB-twisted rudder with a rudder bulb added onto the Z-twisted rudder, and 3 the ZB-F twisted rudder with a rudder fin attached to the ZB-twisted rudder. The twisted rudders have been designed computationally with the hydrodynamic characteristics in a self-propulsion condition in mind. The governing equation is the Navier-Stokes equations in an unsteady turbulent flow. The turbulence model applied is the Reynolds stress. The calculation was carried out in towing and self-propulsion conditions. The sliding mesh technique was employed to simulate the flow around the propeller. The speed performances of the ship with the twisted rudders were verified through model tests in a towing tank. The twisted versions showed greater performance driven by increased hull efficiency from less thrust deduction fraction and more effective wake fraction and decreased propeller rotating speed.

Development of a non-intrusive method for the determination of the moderator temperature coefficient of reactivity (MTC)

International Nuclear Information System (INIS)

Demaziere, C.

2000-01-01

The Moderator Temperature Coefficient of reactivity (MTC) plays an important role in the feedback mechanism and thus in the inherent stability of Pressurised Water Reactors (PWRs). Due to the inaccuracy of the traditional at-power MTC measurement techniques, many power utilities nowadays only measure the zero-power MTC since its determination is relatively straightforward and accurate. For the at-power MTC determination during the remaining fuel cycle, core calculations are assumed to be reliable enough. Nevertheless, these calculations were never benchmarked and most importantly, the use of high burnup fuel might induce a slightly positive MTC at Beginning Of Cycle (BOC) due to the high initial boron concentration. Even if in such a case the Doppler effect would still insure a negative reactivity feedback, monitoring the MTC throughout the cycle could become crucial. In this respect, not only the sign of the MTC is of importance, but also its magnitude. Consequently, developing a method that would permit monitoring the MTC during the fuel cycle is of great interest. One of the main disadvantages of the traditional at-power MTC measurement techniques is that the reactor has to be perturbed in order to induce a change of the moderator temperature. The modification of other parameters that can only be estimated by core calculation represents also a severe drawback of these methods, both for their precision and their reliability. A measurement performed at Ringhals-4 by using the so-called boron dilution method revealed that the uncertainty associated to the MTC estimation could even be much larger than previously expected due to the calculated reactivity corrections. These corrections are very sensitive to the input parameters chosen for the core simulation, and slight mis-estimations of these have large reactivity effects. It is known that if the reactivity noise and the moderator temperature noise could be measured, the MTC could be determined without disturbing

Development of a non-intrusive method for the determination of the moderator temperature coefficient of reactivity (MTC)

Energy Technology Data Exchange (ETDEWEB)

Demaziere, C

2000-07-01

The Moderator Temperature Coefficient of reactivity (MTC) plays an important role in the feedback mechanism and thus in the inherent stability of Pressurised Water Reactors (PWRs). Due to the inaccuracy of the traditional at-power MTC measurement techniques, many power utilities nowadays only measure the zero-power MTC since its determination is relatively straightforward and accurate. For the at-power MTC determination during the remaining fuel cycle, core calculations are assumed to be reliable enough. Nevertheless, these calculations were never benchmarked and most importantly, the use of high burnup fuel might induce a slightly positive MTC at Beginning Of Cycle (BOC) due to the high initial boron concentration. Even if in such a case the Doppler effect would still insure a negative reactivity feedback, monitoring the MTC throughout the cycle could become crucial. In this respect, not only the sign of the MTC is of importance, but also its magnitude. Consequently, developing a method that would permit monitoring the MTC during the fuel cycle is of great interest. One of the main disadvantages of the traditional at-power MTC measurement techniques is that the reactor has to be perturbed in order to induce a change of the moderator temperature. The modification of other parameters that can only be estimated by core calculation represents also a severe drawback of these methods, both for their precision and their reliability. A measurement performed at Ringhals-4 by using the so-called boron dilution method revealed that the uncertainty associated to the MTC estimation could even be much larger than previously expected due to the calculated reactivity corrections. These corrections are very sensitive to the input parameters chosen for the core simulation, and slight mis-estimations of these have large reactivity effects. It is known that if the reactivity noise and the moderator temperature noise could be measured, the MTC could be determined without disturbing

MIBI-{sup 99m}Tc mammary scintigraphy; Centellografia mamaria con MIBI-{sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Mayosky, Maria C; Parma, Elvira P; Armesto, Amparo M; Zarlenga, Ana C [Instituto de Oncologia Angel H. Roffo, Buenos Aires (Argentina). Centro Oncologico de Medicina Nuclear; Cresta, Carlos; Azar, Maria E; Noblia, Cristina [Instituto de Oncologia Angel H. Roffo, Buenos Aires (Argentina). Servicio de Mastologia

1999-07-01

121 patients suspected of breast cancer were studied with MIBI-{sup 99m}Tc to evaluate the suitability of the mammary scintigraphy in patients with doubtful cancer diagnosis.The results show 93 % sensitivity and 95 % specificity and indicate the usefulness of this procedure to increase the accuracy of the diagnosis.

Effect of iron deficiency anemia on the biodistribution of {sup 99m}Tc radiopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

Calmanovici, Gabriela P. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Salgueiro, Maria J. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Janjetic, Mariana A. [Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Leonardi, Natalia M. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Boccio, Jose R. [Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina); Zubillaga, Marcela B. [Radioisotopes Laboratory, Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956 - 1113, Buenos Aires (Argentina)]. E-mail: mzubi@ffyb.uba.ar

2006-05-15

The distribution of colloids and labeled cells in organs is influenced by their intrinsic properties and by the state of the investigated subject. Iron deficiency remains an unsolved nutritional problem all over the world; one of its severe consequences is anemia. Because iron metabolism principally takes place in the liver, spleen, bone marrow, skeletal muscle and blood, we studied the effect of iron deficiency anemia on the biodistribution of {sup 99m}Tc phytate, {sup 99m}Tc gelatin colloid and {sup 99m}Tc RBC (red blood cells labeled with {sup 99m}Tc). Our results show that iron deficiency anemia modifies the pattern of biodistribution of the two colloids assayed. However, this behavior is different for both of them. This work contributes to studies that kinetically and statistically establish that iron deficiency anemia induces a significant inversion in the spleen-liver activity relationship when centellographic studies are performed with colloids such as {sup 99m}Tc phytate.

Partial twisting for scalar mesons

International Nuclear Information System (INIS)

Agadjanov, Dimitri; Meißner, Ulf-G.; Rusetsky, Akaki

2014-01-01

The possibility of imposing partially twisted boundary conditions is investigated for the scalar sector of lattice QCD. According to the commonly shared belief, the presence of quark-antiquark annihilation diagrams in the intermediate state generally hinders the use of the partial twisting. Using effective field theory techniques in a finite volume, and studying the scalar sector of QCD with total isospin I=1, we however demonstrate that partial twisting can still be performed, despite the fact that annihilation diagrams are present. The reason for this are delicate cancellations, which emerge due to the graded symmetry in partially quenched QCD with valence, sea and ghost quarks. The modified Lüscher equation in case of partial twisting is given

{sup 99m}Tc generator preparation using (n, {gamma}){sup 99}Mo produced ex-natural molybdenum

Energy Technology Data Exchange (ETDEWEB)

Le, So Van [Nuclear Research Institute, Dalat (Viet Nam)

2003-03-01

Theoretical assessment on the chromatographic {sup 99m}Tc generator preparation using (n, {gamma}) {sup 99}Mo produced ex-natural molybdenum was carried out. The relationship between the neutron flux for MoO{sub 3} target activation, Mo-content or Mo adsorption capacity of column packing material, {sup 99m}Tc pertechnetate concentration and/or {sup 99m}Tc radioactivity of eluate was established. The reasonably lower limit of neutron flux of reactor and Molybdenum content of column packing material were found out to estimate the production of portable chromatographic generators available for nuclear medicine application. The concentration of {sup 99m}Tc pertechnetate eluate of low {sup 99m}Tc concentration using the column elution technique was also evaluate theoretically and conducted successfully in practice. Three options of {sup 99m}Tc generator using Titanium-Molybdate, Zirconium-Molybdate and Zirconium Oxide as generator column-packing materials were prepared and successfully put into use in nuclear medicine application. (author)

A new approach for manufacturing and processing targets to produce 99mTc with cyclotrons

Science.gov (United States)

Matei, L.; McRae, G.; Galea, R.; Niculae, D.; Craciun, L.; Leonte, R.; Surette, G.; Langille, S.; Louis, C. St.; Gelbart, W.; Abeysekera, B.; Johnson, R. R.

2017-06-01

The most important radioisotope for nuclear medicine is 99mTc. After the supply crisis of 99Mo starting in 2008, the availability of 99mTc became a worldwide concern. Alternative methods for producing the medical imaging isotope 99mTc are actively being developed around the world. The reaction 100Mo(p, 2n)99mTc provides a direct route that can be incorporated into routine production in nuclear medicine centers that possess medical cyclotrons for production of other isotopes, such as those used for Positron Emission Tomography. This paper describes a new approach for manufacturing targets for the (p, 2n) nuclear reaction on 100Mo and the foundation for the subsequent commercial separation and purification of the 99mTc produced. Two designs of targets are presented. The targets used to produce 99mTc are subject to a number of operational constraints.They must withstand the temperatures generated by the irradiation, accommodate temperature gradients from cooling system of the target, must be resilient and must be easily post-processed to separate the 99mTc. After irradiation, the separation of Tc from Mo was carried out using an innovative two-step approach. The process described in this paper can be automated with modules that easily fit in standard production hot cells found in nuclear medicine facilities.

Osteomyelitis diagnosis by {sup 99m}Tc radiolabeled aptamers

Energy Technology Data Exchange (ETDEWEB)

Santos, S.R.; Ferreira, I.M.; Andrade, A.S.R., E-mail: sararoberta7@hotmail.com, E-mail: imendesf@yahoo.com.br, E-mail: antero@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Barros, A.L.B.; Cardoso, V.N.; Diniz, O.F., E-mail: brancodebarros@yahoo.com.br, E-mail: valbertcardoso@yahoo.com.br, E-mail: simoneodilia@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Departamento de Analises Clinicas e Toxicologicas

2015-07-01

Osteomyelitis, which is characterized by progressive inflammatory destruction and new opposition of bone, is still a difficult infection to treat. The clinical diagnosis in late stages is achieved easily, but an early diagnosis is more challenging. Staphylococcus aureus is a common agent found in osteomyelitis and bone prostheses infection. Diagnosis by scintigraphy has advantages because it is a non-invasive procedure and is able to perform an early diagnosis even before anatomic changes. Thus, nuclear medicine could contribute to an accurate diagnosis since specific radiopharmaceuticals were developed. In this study, aptamers selected to Staphylococcus aureus were labeled with {sup 99m}Tc and used for bacteria identification in an osteomyelitis experimental model. The aptamers selected to S. aureus were directly labelled with {sup 99m}Tc and were evaluated by biodistribution studies. Wistar rats with intraosseous infection in the right paw were used. A random aptamer labelled with {sup 99m}Tc was as control. Six animals were used in each group. The aptamers labeled with {sup 99m}Tc were able to identify the infection foci caused by S. aureus displaying a target/non-target ratio of 2,23 ± 0,20, after 3 h. The control group presented a target/non-target ratio 1,08 ± 0.23. The results indicated that the radiolabeled aptamers were able to identify specifically the infection foci and they should be further explored for infection diagnosis by scintigraphy. (author)

Labelled Preformed liposomes with 99MTC-DTPA, 99 MTC-ECD, 99MTC-MDP and 99MTC-MIBI : Labelling procedures and stability studies

International Nuclear Information System (INIS)

Savio, E.O.; Teran, M.A.; Vales, M.E.; Frier, M.

2004-01-01

Liposomes labelled with gamma e miters like 99mTc, can be used for scintigraphic imaging to non-invasively track and quantify the distribution of liposomes in the body. In vitro studies were done to choose a suitable radiopharmaceutical (RF) to be attached to performed liposomes. 99mTc-Complexes (DTPA, ECD, MDP, MIBI) were used to label collagen liposomes. Commercial kits were labelled with 99mTc04-(TechnoNuclear). Quality controls of the RF were performed. Collagen liposomes suspended in saline 0.9% were incubated at 4.25.37 and 60 for 30 min. Efficiency of the labelling procedure was determined by gel filtration using Sephadex G25 (Pharmacia) and NaC10.9%. Samples of 100mL (74MBq), were seeded and fractions of 0.5mL were colleted and measured in an ionisation chamber (Capintec CRC). Stability of the labelled liposomes was assessed incubating 0.5mL, of the suspension with 1mL of human serum during 30 min at 37 . Dialysis was performed using dialysis bags of 64 K pore size and NaCI 0.9% at room temperature. Samples of the saline bath were collected at 30.60 and 90 min. and measured in a solid scintillation counter Ortec.Liposomes labelled with 99mTc-DTPA and 99mTcMIBI showed a labelling efficiency of 80%; liposomes incubated with 99mTc-MDP were labelled in a 50% and 99mTc-ECD did not bind to liposomes in the conditions of study. Incubation of labelled liposomes with human serum showed 50% of strong binding to the plasmatic proteins for 99mTc-DTPA but low values (5%) for the other specimens. Labelled liposomes were achieved, with different RF, showing a suitable in vitro stability to perform in vivo studies

Cytometry metadata in XML

Science.gov (United States)

Leif, Robert C.; Leif, Stephanie H.

2016-04-01

Introduction: The International Society for Advancement of Cytometry (ISAC) has created a standard for the Minimum Information about a Flow Cytometry Experiment (MIFlowCyt 1.0). CytometryML will serve as a common metadata standard for flow and image cytometry (digital microscopy). Methods: The MIFlowCyt data-types were created, as is the rest of CytometryML, in the XML Schema Definition Language (XSD1.1). The datatypes are primarily based on the Flow Cytometry and the Digital Imaging and Communication (DICOM) standards. A small section of the code was formatted with standard HTML formatting elements (p, h1, h2, etc.). Results:1) The part of MIFlowCyt that describes the Experimental Overview including the specimen and substantial parts of several other major elements has been implemented as CytometryML XML schemas (www.cytometryml.org). 2) The feasibility of using MIFlowCyt to provide the combination of an overview, table of contents, and/or an index of a scientific paper or a report has been demonstrated. Previously, a sample electronic publication, EPUB, was created that could contain both MIFlowCyt metadata as well as the binary data. Conclusions: The use of CytometryML technology together with XHTML5 and CSS permits the metadata to be directly formatted and together with the binary data to be stored in an EPUB container. This will facilitate: formatting, data- mining, presentation, data verification, and inclusion in structured research, clinical, and regulatory documents, as well as demonstrate a publication's adherence to the MIFlowCyt standard, promote interoperability and should also result in the textual and numeric data being published using web technology without any change in composition.

Analysis list: Twist1 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Twist1 Embryo,Neural + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Tw...ist1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Twist1.5.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/mm9/target/Twist1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Twist1.Embryo.tsv,http://dbarchive.bioscien...cedbc.jp/kyushu-u/mm9/colo/Twist1.Neural.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/colo/Embryo.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Neural.gml ...

Modeling and control of active twist aircraft

Science.gov (United States)

Cramer, Nicholas Bryan

The Wright Brothers marked the beginning of powered flight in 1903 using an active twist mechanism as their means of controlling roll. As time passed due to advances in other technologies that transformed aviation the active twist mechanism was no longer used. With the recent advances in material science and manufacturability, the possibility of the practical use of active twist technologies has emerged. In this dissertation, the advantages and disadvantages of active twist techniques are investigated through the development of an aeroelastic modeling method intended for informing the designs of such technologies and wind tunnel testing to confirm the capabilities of the active twist technologies and validate the model. Control principles for the enabling structural technologies are also proposed while the potential gains of dynamic, active twist are analyzed.

Current Outlook for 99mTc Distribution Based on Electron Accelerator Production

International Nuclear Information System (INIS)

Benjamin L. Nelson; W. David Bence; John R. Snyder

2007-01-01

In 1999 a practical example illustrating the economical and reliable production of 99mTc from an accelerator was developed. It included the realistic costs involved in establishing and operating the accelerator facility and the distribution of the 99mTc to regions in Florida. However, the technology was never commercialized. Recent political and economic developments prompted this second look at accelerator produced 99mTc. The practicality of this system in 2007 dollars was established to account for inflation and current demand. The same distribution model and production schedule from the Global 1999 study were used. Numbers were found using current rates and costs where possible and indexed estimations when necessary. Though several of the costs increased significantly and the sale price remains at approximately 35 cents/mCi, the unit cost of 99mTc throughput only increased from 12.8 cents/mCi to 15.0 cents/mCi or approximately 17.2% from 1999 to 2007 thus continuing to be economically viable. This study provides ground work for creating business development models at additional locations within the U.S

Teaching Spatial Awareness for Better Twisting Somersaults.

Science.gov (United States)

Hennessy, Jeff T.

1985-01-01

The barani (front somersault with one-half twist) and the back somersault with one twist are basic foundation skills necessary for more advanced twisting maneuvers. Descriptions of these movements on a trampoline surface are offered. (DF)

Twist deformations of the supersymmetric quantum mechanics

Energy Technology Data Exchange (ETDEWEB)

Castro, P.G.; Chakraborty, B.; Toppan, F., E-mail: pgcastro@cbpf.b, E-mail: biswajit@bose.res.i, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Kuznetsova, Z., E-mail: zhanna.kuznetsova@ufabc.edu.b [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

2009-07-01

The N-extended supersymmetric quantum mechanics is deformed via an abelian twist which preserves the super-Hopf algebra structure of its universal enveloping superalgebra. Two constructions are possible. For even N one can identify the 1D N-extended superalgebra with the fermionic Heisenberg algebra. Alternatively, supersymmetry generators can be realized as operators belonging to the Universal Enveloping Superalgebra of one bosonic and several fermionic oscillators. The deformed system is described in terms of twisted operators satisfying twist deformed (anti)commutators. The main differences between an abelian twist defined in terms of fermionic operators and an abelian twist defined in terms of bosonic operators are discussed. (author)

Ten helical twist angles of B-DNA

Energy Technology Data Exchange (ETDEWEB)

Kabsch, W; Sander, C; Trifonov, E N

1982-01-01

On the assumption that the twist angles between adjacent base-pairs in the DNA molecule are additive a linear system of 40 equations was derived from experimental measurements of the total twist angles for different pieces of DNA of known sequences. This system of equations is found to be statistically consistent providing a solution for all ten possible twist angles of B-DNA by a least squares fitting procedure. Four of the calculated twist angles were not known before. The other six twist angles calculated are very close to the experimentally measured ones. The data used were obtained by the electrophoretic band-shift method, crystallography and nuclease digestion of DNA adsorbed to mica or Ca-phosphate surface. The validity of the principle of additivity of the twist angles implies that the angle between any particular two base-pairs is a function of only these base-pairs, independent of nearest neighbors.

Isolation and labelling of human leucocytes with sup(99m)Tc

International Nuclear Information System (INIS)

Kalbaek, H.

1986-01-01

The role of the leucocyte isolation procedure on cell labeling with sup(99m)Tc has been evaluated. Separation of leucocytes was performed by two procedures: (1) sedimentation on methyl cellulose, followed by discontinuous gradient centrifugation; (2) methyl cellulose sedimentation and hypotonic haemolysis of residual red blood cells. After washing the cells in saline and incubation with a stannous pyrophosphate agent, the leucocytes were labelled with 5-10 mCi sup(99m)Tc. Procedure 1 gave a higher purity but lower recovery of polymorphonuclear leucocytes, and a minor contamination of red blood cells. sup(99m)Tc labelling of cells was slightly more efficient with this method, probably due to the presence of red blood cells. Procedure 1 is recommended for in vitro studies on cell kinetics and procedure 2 is recommended for clinical use. (orig.)

European symposium on cytometry

International Nuclear Information System (INIS)

1987-01-01

This book of abstracts contains 59 contributions about cervical prescreening, expert systems, breast cancer, ploidy analysis, system and data evaluation, sampling, preparation and staining, image cytometry, general cytometry, cell kinetics with clinical applications. (AJ)

Status of {sup 99}Mo-{sup 99m}Tc production development by (n, {gamma}) reaction

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, Kunihiko; Kaminaga, Masanori; Ishihara, Masahiro; Kawamura, Hiroshi [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan); Mutalib, Abdul [National Nuclear Energy Agency of Indonesia (BATAN), Tangerang (Indonesia); Chakrov, Petr [Institute of Nuclear Physics, National Nuclear Center of Republic of Kazakhstan (INP-NNC-RK), Almaty (Kazakhstan)

2012-03-15

Technetium-99m ({sup 99m}Tc) is one of the most commonly used radioisotopes in the field of nuclear medicine. As one of effective uses of the JMTR, JAEA has a plan to produce {sup 99}Mo by (n, {gamma}) method, a parent nuclide of {sup 99m}Tc. JAEA has performed R and D on production method of {sup 99}Mo-{sup 99m}Tc in JMTR cooperating with foreign organizations and relevant Japanese enterprises under the cooperation programs. In this paper, present status of R and D for production of {sup 99}Mo-{sup 99m}Tc in JMTR under international cooperation is introduced and constructions of the irradiation and PIE facilities at the JMTR site are also described. (author)

Twisted electron-acoustic waves in plasmas

International Nuclear Information System (INIS)

Aman-ur-Rehman; Ali, S.; Khan, S. A.; Shahzad, K.

2016-01-01

In the paraxial limit, a twisted electron-acoustic (EA) wave is studied in a collisionless unmagnetized plasma, whose constituents are the dynamical cold electrons and Boltzmannian hot electrons in the background of static positive ions. The analytical and numerical solutions of the plasma kinetic equation suggest that EA waves with finite amount of orbital angular momentum exhibit a twist in its behavior. The twisted wave particle resonance is also taken into consideration that has been appeared through the effective wave number q_e_f_f accounting for Laguerre-Gaussian mode profiles attributed to helical phase structures. Consequently, the dispersion relation and the damping rate of the EA waves are significantly modified with the twisted parameter η, and for η → ∞, the results coincide with the straight propagating plane EA waves. Numerically, new features of twisted EA waves are identified by considering various regimes of wavelength and the results might be useful for transport and trapping of plasma particles in a two-electron component plasma.

Electronic and Optical Properties of Twisted Bilayer Graphene

Science.gov (United States)

Huang, Shengqiang

The ability to isolate single atomic layers of van der Waals materials has led to renewed interest in the electronic and optical properties of these materials as they can be fundamentally different at the monolayer limit. Moreover, these 2D crystals can be assembled together layer by layer, with controllable sequence and orientation, to form artificial materials that exhibit new features that are not found in monolayers nor bulk. Twisted bilayer graphene is one such prototype system formed by two monolayer graphene layers placed on top of each other with a twist angle between their lattices, whose electronic band structure depends on the twist angle. This thesis presents the efforts to explore the electronic and optical properties of twisted bilayer graphene by Raman spectroscopy and scanning tunneling microscopy measurements. We first synthesize twisted bilayer graphene with various twist angles via chemical vapor deposition. Using a combination of scanning tunneling microscopy and Raman spectroscopy, the twist angles are determined. The strength of the Raman G peak is sensitive to the electronic band structure of twisted bilayer graphene and therefore we use this peak to monitor changes upon doping. Our results demonstrate the ability to modify the electronic and optical properties of twisted bilayer graphene with doping. We also fabricate twisted bilayer graphene by controllable stacking of two graphene monolayers with a dry transfer technique. For twist angles smaller than one degree, many body interactions play an important role. It requires eight electrons per moire unit cell to fill up each band instead of four electrons in the case of a larger twist angle. For twist angles smaller than 0.4 degree, a network of domain walls separating AB and BA stacking regions forms, which are predicted to host topologically protected helical states. Using scanning tunneling microscopy and spectroscopy, these states are confirmed to appear on the domain walls when inversion

Radiation damage to mouse testis cells from [/sup 99m/Tc] pertechnetate

International Nuclear Information System (INIS)

Mian, T.A.; Suzuki, N.; Glenn, H.J.; Haynie, T.P.; Meistrich, M.L.

1977-01-01

The radiation dose and the biologic damage to mouse testis from intravenously administered [/sup 99m/Tc] pertechnetate were studied. The dose was measured for penetrating radiations from /sup 99m/Tc, using calibrated thermoluminescent dosimeters and calculations from the uptake of the nuclide in the testis, and was found to be 4.9 rads per mCi of 99 Tc. The biologic damage was measured by the decrease in the number of sperm heads in the testis, counted both by hemacytometer and by Coulter counter. In preliminary experiments using external gamma radiation from 137 Cs, the number of sperm heads reached a minimum 29 days after irradiation. Twenty-nine days after injection of 5.8 mCi of /sup 99m/Tc, which gives 28 rads to the testis, the number of sperm heads decreased to 70% of control. The biologic effect corresponds to that seen after 40 rads of gamma radiation from 137 Cs. The damage to mouse testis cells from internally administered /sup 99m/Tc as measured in an in vivo system appears to be at least as significant as that from external gamma irradiation, if not more so

Remarks on twisted noncommutative quantum field theory

Energy Technology Data Exchange (ETDEWEB)

Zahn, J. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2006-04-15

We review recent results on twisted noncommutative quantum field theory by embedding it into a general framework for the quantization of systems with a twisted symmetry. We discuss commutation relations in this setting and show that the twisted structure is so rigid that it is hard to derive any predictions, unless one gives up general principles of quantum theory. It is also shown that the twisted structure is not responsible for the presence or absence of UV/IR-mixing, as claimed in the literature. (Orig.)

Morphing wing structure with controllable twist based on adaptive bending-twist coupling

Science.gov (United States)

Raither, Wolfram; Heymanns, Matthias; Bergamini, Andrea; Ermanni, Paolo

2013-06-01

A novel semi-passive morphing airfoil concept based on variable bending-twist coupling induced by adaptive shear center location and torsional stiffness is presented. Numerical parametric studies and upscaling show that the concept relying on smart materials permits effective twist control while offering the potential of being lightweight and energy efficient. By means of an experimental characterization of an adaptive beam and a scaled adaptive wing structure, effectiveness and producibility of the structural concept are demonstrated.

Morphing wing structure with controllable twist based on adaptive bending–twist coupling

International Nuclear Information System (INIS)

Raither, Wolfram; Heymanns, Matthias; Ermanni, Paolo; Bergamini, Andrea

2013-01-01

A novel semi-passive morphing airfoil concept based on variable bending–twist coupling induced by adaptive shear center location and torsional stiffness is presented. Numerical parametric studies and upscaling show that the concept relying on smart materials permits effective twist control while offering the potential of being lightweight and energy efficient. By means of an experimental characterization of an adaptive beam and a scaled adaptive wing structure, effectiveness and producibility of the structural concept are demonstrated. (paper)

Conical twist fields and null polygonal Wilson loops

Science.gov (United States)

Castro-Alvaredo, Olalla A.; Doyon, Benjamin; Fioravanti, Davide

2018-06-01

Using an extension of the concept of twist field in QFT to space-time (external) symmetries, we study conical twist fields in two-dimensional integrable QFT. These create conical singularities of arbitrary excess angle. We show that, upon appropriate identification between the excess angle and the number of sheets, they have the same conformal dimension as branch-point twist fields commonly used to represent partition functions on Riemann surfaces, and that both fields have closely related form factors. However, we show that conical twist fields are truly different from branch-point twist fields. They generate different operator product expansions (short distance expansions) and form factor expansions (large distance expansions). In fact, we verify in free field theories, by re-summing form factors, that the conical twist fields operator product expansions are correctly reproduced. We propose that conical twist fields are the correct fields in order to understand null polygonal Wilson loops/gluon scattering amplitudes of planar maximally supersymmetric Yang-Mills theory.

Renormalization constants for 2-twist operators in twisted mass QCD

International Nuclear Information System (INIS)

Alexandrou, C.; Constantinou, M.; Panagopoulos, H.; Stylianou, F.; Korzec, T.

2011-01-01

Perturbative and nonperturbative results on the renormalization constants of the fermion field and the twist-2 fermion bilinears are presented with emphasis on the nonperturbative evaluation of the one-derivative twist-2 vector and axial-vector operators. Nonperturbative results are obtained using the twisted mass Wilson fermion formulation employing two degenerate dynamical quarks and the tree-level Symanzik improved gluon action. The simulations have been performed for pion masses in the range of about 450-260 MeV and at three values of the lattice spacing a corresponding to β=3.9, 4.05, 4.20. Subtraction of O(a 2 ) terms is carried out by performing the perturbative evaluation of these operators at 1-loop and up to O(a 2 ). The renormalization conditions are defined in the RI ' -MOM scheme, for both perturbative and nonperturbative results. The renormalization factors, obtained for different values of the renormalization scale, are evolved perturbatively to a reference scale set by the inverse of the lattice spacing. In addition, they are translated to MS at 2 GeV using 3-loop perturbative results for the conversion factors.

How to Twist a Knot

DEFF Research Database (Denmark)

Randrup, Thomas; Røgen, Peter

1997-01-01

is an invariant of ambient isotopy measuring the topological twist of the closed strip. We classify closed strips in euclidean 3-space by their knots and their twisting number. We prove that this classification exactly divides closed strips into isotopy classes. Using this classification we point out how some...

Transverse kink oscillations in the presence of twist

Science.gov (United States)

Terradas, J.; Goossens, M.

2012-12-01

Context. Magnetic twist is thought to play an important role in coronal loops. The effects of magnetic twist on stable magnetohydrodynamic (MHD) waves is poorly understood because they are seldom studied for relevant cases. Aims: The goal of this work is to study the fingerprints of magnetic twist on stable transverse kink oscillations. Methods: We numerically calculated the eigenmodes of propagating and standing MHD waves for a model of a loop with magnetic twist. The azimuthal component of the magnetic field was assumed to be small in comparison to the longitudinal component. We did not consider resonantly damped modes or kink instabilities in our analysis. Results: For a nonconstant twist the frequencies of the MHD wave modes are split, which has important consequences for standing waves. This is different from the degenerated situation for equilibrium models with constant twist, which are characterised by an azimuthal component of the magnetic field that linearly increases with the radial coordinate. Conclusions: In the presence of twist standing kink solutions are characterised by a change in polarisation of the transverse displacement along the tube. For weak twist, and in the thin tube approximation, the frequency of standing modes is unaltered and the tube oscillates at the kink speed of the corresponding straight tube. The change in polarisation is linearly proportional to the degree of twist. This has implications with regard to observations of kink modes, since the detection of this variation in polarisation can be used as an indirect method to estimate the twist in oscillating loops.

Hyperchromatic laser scanning cytometry

Science.gov (United States)

Tárnok, Attila; Mittag, Anja

2007-02-01

In the emerging fields of high-content and high-throughput single cell analysis for Systems Biology and Cytomics multi- and polychromatic analysis of biological specimens has become increasingly important. Combining different technologies and staining methods polychromatic analysis (i.e. using 8 or more fluorescent colors at a time) can be pushed forward to measure anything stainable in a cell, an approach termed hyperchromatic cytometry. For cytometric cell analysis microscope based Slide Based Cytometry (SBC) technologies are ideal as, unlike flow cytometry, they are non-consumptive, i.e. the analyzed sample is fixed on the slide. Based on the feature of relocation identical cells can be subsequently reanalyzed. In this manner data on the single cell level after manipulation steps can be collected. In this overview various components for hyperchromatic cytometry are demonstrated for a SBC instrument, the Laser Scanning Cytometer (Compucyte Corp., Cambridge, MA): 1) polychromatic cytometry, 2) iterative restaining (using the same fluorochrome for restaining and subsequent reanalysis), 3) differential photobleaching (differentiating fluorochromes by their different photostability), 4) photoactivation (activating fluorescent nanoparticles or photocaged dyes), and 5) photodestruction (destruction of FRET dyes). With the intelligent combination of several of these techniques hyperchromatic cytometry allows to quantify and analyze virtually all components of relevance on the identical cell. The combination of high-throughput and high-content SBC analysis with high-resolution confocal imaging allows clear verification of phenotypically distinct subpopulations of cells with structural information. The information gained per specimen is only limited by the number of available antibodies and by sterical hindrance.

WORKSHOP: Let's twist again..

Energy Technology Data Exchange (ETDEWEB)

Villalobos Baillie, Orlando

1988-12-15

In the quantum chromodynamics (QCD) candidate theory of interquark forces, calculations involve summing the effects from many different possible quark/gluon interactions. In addition to the 'leading term' frequently used as the basis for QCD calculations, additional contributions — so-called 'higher twists' — are modulated by powers of kinematical factors. An illuminating international workshop to discuss higher twist QCD was held at the College de France, Paris, from 21-23 September.

DVCS amplitude with kinematical twist-3 terms

International Nuclear Information System (INIS)

Radyushkin, A.V.; Weiss, C.

2000-01-01

The authors compute the amplitude of deeply virtual Compton scattering (DVCS) using the calculus of QCD string operators in coordinate representation. To restore the electromagnetic gauge invariance (transversality) of the twist-2 amplitude they include the operators of twist-3 which appear as total derivatives of twist-2 operators. The results are equivalent to a Wandzura-Wilczek approximation for twist-3 skewed parton distributions. They find that this approximation gives a finite result for the amplitude of a longitudinally polarized virtual photon, while the amplitude for transverse polarization is divergent, i.e., factorization breaks down in this term

High-resolution cytometry represents the main technology used in the laboratory of molecular cytology and cytometry

Czech Academy of Sciences Publication Activity Database

Kozubek, Stanislav; Bártová, Eva; Lukášová, Emilie; Falk, Martin; Ondřej, Vladan; Kozubek, Michal; Kroupová, Jana; Matula, Pe.; Matula, Pa.

2006-01-01

Roč. 39, č. 5 (2006), s. 341-341 ISSN 0960-7722. [Cytomics Emerging from Cytometry 16th Annual Meeting of the german Society for cytometry. 18.10.2006-21.10.2006, Leipzig] Institutional research plan: CEZ:AV0Z50040507 Keywords : high-resolution cytometry * cytogenetics * epigenetics Subject RIV: BO - Biophysics

OFDM with Index Modulation for Asynchronous mMTC Networks.

Science.gov (United States)

Doğan, Seda; Tusha, Armed; Arslan, Hüseyin

2018-04-21

One of the critical missions for next-generation wireless communication systems is to fulfill the high demand for massive Machine-Type Communications (mMTC). In mMTC systems, a sporadic transmission is performed between machine users and base station (BS). Lack of coordination between the users and BS in time destroys orthogonality between the subcarriers, and causes inter-carrier interference (ICI). Therefore, providing services to asynchronous massive machine users is a major challenge for Orthogonal Frequency Division Multiplexing (OFDM). In this study, OFDM with index modulation (OFDM-IM) is proposed as an eligible solution to alleviate ICI caused by asynchronous transmission in uncoordinated mMTC networks. In OFDM-IM, data transmission is performed not only by modulated subcarriers but also by the indices of active subcarriers. Unlike classical OFDM, fractional subcarrier activation leads to less ICI in OFDM-IM technology. A novel subcarrier mapping scheme (SMS) named as Inner Subcarrier Activation is proposed to further alleviate adjacent user interference in asynchronous OFDM-IM-based systems. ISA reduces inter-user interference since it gives more activation priority to inner subcarriers compared with the existing SMS-s. The superiority of the proposed SMS is shown through both theoretical analysis and computer-based simulations in comparison to existing mapping schemes for asynchronous systems.

Processing mechanics of alternate twist ply (ATP) yarn technology

Science.gov (United States)

Elkhamy, Donia Said

Ply yarns are important in many textile manufacturing processes and various applications. The primary process used for producing ply yarns is cabling. The speed of cabling is limited to about 35m/min. With the world's increasing demands of ply yarn supply, cabling is incompatible with today's demand activated manufacturing strategies. The Alternate Twist Ply (ATP) yarn technology is a relatively new process for producing ply yarns with improved productivity and flexibility. This technology involves self plying of twisted singles yarn to produce ply yarn. The ATP process can run more than ten times faster than cabling. To implement the ATP process to produce ply yarns there are major quality issues; uniform Twist Profile and yarn Twist Efficiency. The goal of this thesis is to improve these issues through process modeling based on understanding the physics and processing mechanics of the ATP yarn system. In our study we determine the main parameters that control the yarn twist profile. Process modeling of the yarn twist across different process zones was done. A computational model was designed to predict the process parameters required to achieve a square wave twist profile. Twist efficiency, a measure of yarn torsional stability and bulk, is determined by the ratio of ply yarn twist to singles yarn twist. Response Surface Methodology was used to develop the processing window that can reproduce ATP yarns with high twist efficiency. Equilibrium conditions of tensions and torques acting on the yarns at the self ply point were analyzed and determined the pathway for achieving higher twist efficiency. Mechanistic modeling relating equilibrium conditions to the twist efficiency was developed. A static tester was designed to zoom into the self ply zone of the ATP yarn. A computer controlled, prototypic ATP machine was constructed and confirmed the mechanistic model results. Optimum parameters achieving maximum twist efficiency were determined in this study. The

Engineer Research and Development Center's Materials Testing Center (MTC)

Data.gov (United States)

Federal Laboratory Consortium — The Engineer Research and Development Center's Materials Testing Center (MTC) is committed to quality testing and inspection services that are delivered on time and...

Effects of concurrent drug therapy on technetium /sup 99m/Tc gluceptate biodistribution

International Nuclear Information System (INIS)

Hinkle, G.H.; Basmadjian, G.P.; Peek, C.; Barker, K.K.; Ice, R.D.

1982-01-01

Drug interactions with /sup 99m/Tc gluceptate resulting in altered biodistribution were studied using chart review and animal tests. Charts of nine patients who had abnormal gallbladder uptake of technetium /sup 99m/Tc gluceptate during a two-year period were reviewed to obtain data such as concurrent drug therapy, primary diagnosis, and laboratory values. Adult New Zealand white rabbits were then used for testing the biodistribution of technetium /sup 99m/Tc gluceptate when administered concurrently with possibly interacting drugs identified in the chart review--penicillamine, penicillin G potassium, penicillin V potassium, acetaminophen, and trimethoprim-sulfamethoxazole. Chart review revealed no conclusive patterns of altered biodistribution associated with other factors. The data did suggest the possibility that the five drugs listed above might cause increased hepatobiliary clearance of the radiopharmaceutical. Animal tests showed that i.v. penicillamine caused substantial distribution of radioactivity into the gallbladder and small bowel. Minimally increased gallbladder radioactivity occurred when oral acetaminophen and trimethoprim-sulfamethoxazole were administered concurrently. Oral and i.v. penicillins did not increase gallbladder activity. Penicillamine may cause substantial alteration of the biodistribution of technetium /sup 99m/Tc gluceptate

{sup 99m}Tc sestamibi imaging. Can it be a useful substitute for hepatobiliary scintigraphy in infantile jaundice?

Energy Technology Data Exchange (ETDEWEB)

Sadeghi, R.; Kakhki, V.R.D.; Zakavi, R. [Mashhad Univ. of Medical Sciences (Iran). Nuclear Medicine Dept.; Kianifar, H.R. [Mashhad Univ. of Medical Sciences (Iran). Paediatric Dept.; Ansari, K. [Tehran Univ. of Medical Sciences (Iran). Nuclear Medicine Dept.

2009-07-01

Hepatobiliary scintigraphy is an integral part in the diagnostic work-up of the neonatal cholestasis syndrome. However, less than optimal specificity is its major disadvantage. Differentiation between biliary atresia and neonatal hepatitis is nearly impossible in some cases with poor hepatocellular function. {sup 99m}Tc sestamibi (MIBI) is a cationic lipophilic agent which is a substrate of P-glycoprotein. This glycoprotein is normally expressed in biliary canalicular surfaces of hepatocytes. This property provides a hepatic excretory mechanism which is different from bilirubin excretion. In this study we evaluated the value of {sup 99m}Tc MIBI in differential diagnosis of neonatal cholestasis. 20 infants with a mean age of 2.41 months (range, 0.1-5 months) were included in the study. Ten infants turned out to have extrahepatic biliary atresia and the other ten had neonatal hepatitis. Hepatobiliary (with {sup 99m}Tc BrIDA) and {sup 99m}Tc MIBI scintigraphy were performed for all the patients. {sup 99m}Tc MIBI scintigraphy has shown bowel activity in all patients, including the patients with biliary atresia. Hepatobiliary scintigraphy revealed bowel activity only in five patients with neonatal hepatitis. Bowel visualization with {sup 99m}Tc MIBI may be seen in patients with biliary atresia and {sup 99m}Tc MIBI has limited value in differential diagnosis of neonatal cholestasis. (orig.)

Role of /sup 99/mTc pertechnetate uptake in the evaluation of thyroid function

Energy Technology Data Exchange (ETDEWEB)

Sucupira, M.S.; Camargo, E.E.; Nickoloff, E.L.; Alderson, P.O.; Wagner, H.N. Jr.

1983-01-01

To investigate the usefulness of the 20 min /sup 99/mTc-pertechnetate uptake test, the records of 246 consecutive patients were reviewed. Of these, 192 patients (151 females, 41 males; 10 weeks to 78 years) had at least one year clinical follow-up or a confirmed diagnosis by biopsy or surgery and were included in our study. In these patients, the /sup 99/mTc pertechnetate uptake and hormonal values (T3 resin uptake, T4 RIA, T-index) were obtained. These results were then compared to the clinical diagnosis at the time of the uptake and one year later. All patients received an i.v. injection of 5 mCi of /sup 99/mTc pertechnetate. Imaging was performed using a pinhole collimator and a scintillation camera interfaced to a computer. Regions of interest for the thyroid and the background were used to calculate the 20 min /sup 99/mTc pertechnetate uptake as a percentage of the injected dose. /sup 99/mTc uptake and hormonal values were confirmatory in 158 patients (82.3%): 138 were euthyroid, 18 were hyperthyroid and 2 were hypothyroid. In 29 other patients (15.1%) the pertechnetate uptake provided useful additional information and helped to identify Hashimoto's thyroiditis (8 patients); thyroid suppression by exogenous iodide, steroids or T4 (7 patients); overtreated hyperthyroidism (1 patient); persistent hyperthyroidism (5 patients); different stages of Grave's disease (4 patients); and toxic nodular goiter (4 patients). The /sup 99/mTc uptake was misleading in 5 euthyroid patients (2.6%). We have found the /sup 99/mTc pertechnetate uptake a useful adjunct to measurement of hormonal levels in patients with suspected thyroid disease.

Twist operators in N=4 beta-deformed theory

NARCIS (Netherlands)

de Leeuw, M.; Łukowski, T.

2010-01-01

In this paper we derive both the leading order finite size corrections for twist-2 and twist-3 operators and the next-to-leading order finite-size correction for twist-2 operators in beta-deformed SYM theory. The obtained results respect the principle of maximum transcendentality as well as

Higher twist contributions to deep-inelastic structure functions

International Nuclear Information System (INIS)

Bluemlein, J.; Boettcher, H.

2008-07-01

We report on a recent extraction of the higher twist contributions to the deep inelastic structure functions F ep,ed 2 (x,Q 2 ) in the large x region. It is shown that the size of the extracted higher twist contributions is strongly correlated with the higher order corrections applied to the leading twist part. A gradual lowering of the higher twist contributions going from NLO to N 4 LO is observed, where in the latter case only the leading large x terms were considered. (orig.)

/sup 99m/Tc labeling of antibodies to cardiac myosin Fab and to human fibrinogen

International Nuclear Information System (INIS)

Khaw, B.A.; Strauss, H.W.; Carvalho, A.; Locke, E.; Gold, H.K.; Haber, E.

1982-01-01

We have developed a method of labeling biologically active labile macromolecules, such as human fibrinogen (HF) and anticardiac-myosin Fab (AM-Fab), with /sup 99m/Tc at neutral pH. This method uses dithionite reduction of pertechnetate and subsequent labeling, to test the method with acid-labile macromolecules. Complexes of diethylene triamine pentaacetic acid with macromolecules such as human fibrinogen (D-HF) and anticardiac-myosin Fab (D-AM-Fab) were labeled and utilized in in vitro and in vivo studies. In biodistribution studies, the /sup 99m/Tc D-HF had a two-component blood clearance (half-times 1 hr and 15 hr) and was 80--88% coagulable. The /sup 99m/Tc AM-Fab retained its immunoreactivity as tested by affinity chromatography; also during in vivo localization in experimental myocardial infarction. This labeling technique provides an easy and efficient approach to the /sup 99m/Tc labeling of other biologically active and acid-labile macromolecules

A novel role for Twist-1 in pulp homeostasis.

Science.gov (United States)

Galler, K M; Yasue, A; Cavender, A C; Bialek, P; Karsenty, G; D'Souza, R N

2007-10-01

The molecular mechanisms that maintain the equilibrium of odontoblast progenitor cells in dental pulp are unknown. Here we tested whether homeostasis in dental pulp is modulated by Twist-1, a nuclear protein that partners with Runx2 during osteoblast differentiation. Our analysis of Twist-1(+/-) mice revealed phenotypic changes that involved an earlier onset of dentin matrix formation, increased alkaline phosphatase activity, and pulp stones within the pulp. RT-PCR analyses revealed Twist-1 expression in several adult organs, including pulp. Decreased levels of Twist-1 led to higher levels of type I collagen and Dspp gene expression in perivascular cells associated with the pulp stones. In mice heterozygous for both Twist-1 and Runx2 inactivation, the phenotype of pulp stones appeared completely rescued. These findings suggest that Twist-1 plays a key role in restraining odontoblast differentiation, thus maintaining homeostasis in dental pulp. Furthermore, Twist-1 functions in dental pulp are dependent on its interaction with Runx2.

The separation of sup(99m)Tc from 99Mo through an aluminium oxide chromatographic columm

International Nuclear Information System (INIS)

Imoto, S.T.

1980-01-01

The separation of sup(99m)Tc from 99 Mo using the chromatographic method is studied. Alumina is used as adsorbent. The pH values for adsorption of carrier-free 99 Mo on columns filled with ordinary alumina and with that thermically treated at 1000 0 C for five hours, and the separation conditions of sup(99m)Tc using physiologic solution as eluent are determined. The sup(99m)Tc separation yields of both columns are compared and the quality of the products obtained by successive elutions for 10 days is analyzed. (Author) [pt

SpaceTwist

DEFF Research Database (Denmark)

Yiu, Man Lung; Jensen, Christian Søndergaard; Xuegang, Huang

2008-01-01

-based matching generally fall short in offering practical query accuracy guarantees. Our proposed framework, called SpaceTwist, rectifies these shortcomings for k nearest neighbor (kNN) queries. Starting with a location different from the user's actual location, nearest neighbors are retrieved incrementally...

Magnetization Modeling of Twisted Superconducting Filaments

CERN Document Server

Satiramatekul, T; Devred, Arnaud; Leroy, Daniel

2007-01-01

This paper presents a new Finite Element numerical method to analyze the coupling between twisted filaments in a superconducting multifilament composite wire. To avoid the large number of elements required by a 3D code, the proposed method makes use of the energy balance principle in a 2D code. The relationship between superconductor critical current density and local magnetic flux density is implemented in the program for the Bean and modified Kim models. The modeled wire is made up of six filaments twisted together and embedded in a lowresistivity matrix. Computations of magnetization cycle and of the electric field pattern have been performed for various twist pitch values in the case of a pure copper matrix. The results confirm that the maximum magnetization depends on the matrix conductivity, the superconductor critical current density, the applied field frequency, and the filament twist pitch. The simulations also lead to a practical criterion for wire design that can be used to assess whether or not th...

Magnesium-Molybate Compounds as Matrix for 99Mo/99mTc Generators

Directory of Open Access Journals (Sweden)

Fabiola Monroy-Guzman

2011-01-01

Full Text Available This work reports the preparation of a 99mTc generator based on conversion of 99Mo produced by neutron irradiation, into insoluble magnesium 99Mo-molybdates compounds as matrix. The effect of magnesium salt types and concentration, Mg:Mo molar ratios, pH of molybdate solutions, eluate volume as well as the addition order of molybdate and magnesium solutions’ influences on the final 99mTc were evaluated. Polymetalates and polymolybdates salts either crystallized or amorphous were obtained depending on the magnesium salt and Mg:Mo molar ratio used in matrix preparation. 99Mo/99mTc generator production based on magnesium-99Mo molybdate compounds allow reduction of preparation time and eliminates the use of specialized installations. The best generator performances were attained using matrices prepared from 0.1 mol/L MgCl2·6H2O solutions, ammonium molybdate solutions at pH 7 and at a Mg:Mo molar ratio of 1:1.

Electrolytic preparation of sup(99m)Tc human serum albumin using tin electrodes

International Nuclear Information System (INIS)

Narasimhan, D.V.S.; Mani, R.S.

1975-01-01

A method for labelling human serum albumin [HSA] with sup(99m)Tc using electrolytically generated Sn/II/ ions has been developed. The procedure uses Sn electrodes for electrolysis and gives high labelling yields. The amount of Sn released into the final product was found to be much less than the reported toxic levels. A ready-to-use kit for obtaining sterile sup(99m)Tc HSA is described. Tin metal wires sealed in aluminium were irradiated in a CIRUS reactor at a neutron flux of 7.5x10 12 n cm -2 sec -1 for one month. The 113 Sn produced in the wire was used for tracer studies with the electrolitically labelled HSA. sup(99m)Tc in the form sodium pertechnetate in 0.9% NaCl was obtained by methyl ethyl ketone extraction from alkaline solutions of neutron irradiated 99 Mo [specific activity 50-200 mCi/g] in the solvent extraction generator developed at Isotope Division, BARC. Radiochemical purity analysis of sup(99m)Tc labelled HSA prepared by the above procedure was carried out by ascending paper chromatography on Whatman No.1 paper, and 85% methanol and 0.9% sodium chloride as solvents. (F.Gy.)

Milking technique of sup(99m)Tc generators and labeling efficiencies

International Nuclear Information System (INIS)

Salehi, N.; Guignard, P.A.

1985-01-01

Increased levels of 99 Tc in generator produced sup(99m)Tc have an adverse effect on the labelling efficiency of red blood cells and human serum albumin. A two-step milking technique in which the first 1-2 ml of eluate is discarded has been found to produce higher and more constant labelling efficiency of lymphocytes and platelets than a one-step procedure. Binding efficiency of platelet-rich plasma and lymphocytes with sup(99m)Tc is greater in the two-step technique. High activity concentration in the eluate for critical labelling is between 1.5-3 ml. (U.K.)

Investigations on the structures of sup(99m)Tc and 113Sn pyrophosphate complexes and of sup(99m)Tc and 113Sn ethane hydroxy diphosphate complexes

International Nuclear Information System (INIS)

Hohloch, M.

1980-01-01

The complex formation of double labelling of bivalent 113 Sn and reduced, quadrovalent sup(99m)Tc with pyrophosphate (PPi) or ethane hydroxy diphosphorate (EHDP) has been investigated by means of in vivo distribution in the rat. The molar rates of sup(99m)Tc and 113 Sn to PPi resp. EHDP, as well as the pH-value and the initial concentration is varied. Furthermore, both elements were oxidized with H 2 O 2 in the alkaline medium. Four typical sup(99m)Tc and two typical 113 Sn in-vivo distribution patterns can be differentiated: 1. Pertechnetate, characterized by a strong enrichment in the stomach, forms when all Sn-II has been oxidized to Sn-IV in the preparation. 2. One bone-seeking 113 Sn-II PPi (EHDP) complex and a sup(99m)Tc-IV PPi (EHDP) complex each, which are formed at least equimolar ratio of Sn to PPi (EHDP) and suffiently high concentration of PPi (EHDP) in the physiological pH-value. 3. A non-bone-seeking sup(99m)Tc-IV compound, which is enriched in the kidneys instead, is formed in the weakly alkaline medium or at low PPi (EHDP) concentration. This is probably monomeric technetium dioxide dihydrate. 4. A sup(99m)Tc as well as a Sn colloid is formed at deficient ligand concentration (PPi or EHDP to Sn). The chemical composition of the complexes is discussed the possible reaction courses are illustrated in the following diagrams. (orig./MG) [de

Follow-up of a case of subacute thyroiditis with uncommon thyroid {sup 99m}Tc uptake

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhe; Li, Chengjiang, E-mail: 10518093zz@163.com [Medical College of Zhejiang University, Hangzhou (China). Hospital of Medical College. Department of Endocrinology and Metabolism

2013-07-01

Thyroidal 99mTc uptake in the acute thyrotoxic phase of subacute thyroiditis (SAT) is always inhibited. However, a patient with SAT had signs in the right-side thyroid gland with transient thyrotoxicosis and slightly high 99mTc uptake levels in the right lobe, low 99mTc uptake in the left lobe, and normal overall uptake. Histological examination showed cellular destruction and granulomatous inflammatory changes in the right lobe, with marked interstitial fibrosis in the left lobe. The patient was thyrotrophin-receptor antibody (TRAb) positive. After a short course of prednisolone, SAT-like symptoms and signs improved. TRAb-positivity resolved spontaneously after 22 months, and TSH levels were slightly low for 22 months. Levels then kept normal in the following four years. In conclusion, high 99mTc uptake by the right lobe was due to the combined effects of TRAb and left thyroid gland fibrosis. (author)

Twisting short dsDNA with applied tension

Science.gov (United States)

Zoli, Marco

2018-02-01

The twisting deformation of mechanically stretched DNA molecules is studied by a coarse grained Hamiltonian model incorporating the fundamental interactions that stabilize the double helix and accounting for the radial and angular base pair fluctuations. The latter are all the more important at short length scales in which DNA fragments maintain an intrinsic flexibility. The presented computational method simulates a broad ensemble of possible molecule conformations characterized by a specific average twist and determines the energetically most convenient helical twist by free energy minimization. As this is done for any external load, the method yields the characteristic twist-stretch profile of the molecule and also computes the changes in the macroscopic helix parameters i.e. average diameter and rise distance. It is predicted that short molecules under stretching should first over-twist and then untwist by increasing the external load. Moreover, applying a constant load and simulating a torsional strain which over-twists the helix, it is found that the average helix diameter shrinks while the molecule elongates, in agreement with the experimental trend observed in kilo-base long sequences. The quantitative relation between percent relative elongation and superhelical density at fixed load is derived. The proposed theoretical model and computational method offer a general approach to characterize specific DNA fragments and predict their macroscopic elastic response as a function of the effective potential parameters of the mesoscopic Hamiltonian.

Four-point functions with a twist

Energy Technology Data Exchange (ETDEWEB)

Bargheer, Till [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

2017-01-15

We study the OPE of correlation functions of local operators in planar N=4 super Yang-Mills theory. The considered operators have an explicit spacetime dependence that is defined by twisting the translation generators with certain R-symmetry generators. We restrict to operators that carry a small number of excitations above the twisted BMN vacuum. The OPE limit of the four-point correlator is dominated by internal states with few magnons on top of the vacuum. The twisting directly couples all spacetime dependence of the correlator to these magnons. We analyze the OPE in detail, and single out the extremal states that have to cancel all double-trace contributions.

Localization of the acute lower gastrointestinal hemorrhage in vivo-in vitro labeling of red blood cells with sup(99m)Tc

International Nuclear Information System (INIS)

Noguera, E.; Mothe, G.; Wyse, E.

1984-01-01

For the detection and localization of acute lower gastrointestinal hemorrhage in vivo-in vitro labeling of red blood cells with sup(99m)Tc and sup(99m)Tc sulfur colloid has been sugested. The procedure for labeling RBC with sup(99m)Tc consisted in injecting IV 1 mg of ClSn; 20 minutes after injection of tin 10 cc of blood were withdrawn in a syringe containing 20 mCi of sup(99m)Tc; this was incubated for 10 minutes and then injected IV. Scintigraphy of the abdominal cavity was done in supine position and performed with a large field gamma camera with a parallel hole-low energy colimator. Computer adquisition of images was started 5 minutes after RBC injection and made at the rate of one enery 5 minutes for 45 minutes. 14 patients were studied divided in: a) control: 6 patients. b) with active gastrointestinal hemorrhage: 4 patients had positive scintigraphy. The hemorrhage was documented with superior mesenteric arteriography, endoscopy and/or necropsy. The sensitivity was 100%. In 4 out of 14 patients scintigraphy with sup(99m)Tc RBC compared with simultaneous sup(99m)Tc sulfur colloid demonstrated that all patients with positive sup(99m)Tc RBC had also positive sup(99m)Tc sulfur colloid scintigraphy. c) without active gastrointestinal hemorrhage: all of them had negative scintigraphy (specificity 100%). Abdominal scintigraphy with sup(99m)Tc RBC or sulfur colloid are both sensitive for detection and localization of lower gastrointestinal bleeding and the negative study suggests the absence of active hemorrhage. It is suggested that the sup(99m)Tc sulfur colloid scintigraphy should be the initial procedure to study these patients and abdominal arteriography should be performed only in patients with positive abdominal scintigraphy. (M.E.L.) [es

Studies on the separation between higher-twist and minimum-twist in the photoproduction experiment WA69 at the CERN-OMEGA spectrometer

International Nuclear Information System (INIS)

Kingler, J.

1990-01-01

A Lund type Monte Carlo program (LUCIFER) is used to describe in perturbative QCD the pointlike component of the photon interacting on a hydrogen target. Kinematical and topological variables are developed to enhance higher twist events on the lowest order minimum twist background. The emphasis is laid on π ± , K ± higher twist mesons. (orig.)

Separation of sup(99m)Tc from 99Mo through a hydrous zirconium oxide column

International Nuclear Information System (INIS)

Mengatti, J.

1980-01-01

The preparation of 99 Mo-,sup(99m)Tc generator based on the adsorption of 99 Mo on hydrous zirconium oxide column, employing the in exchange technique, is described. The adsorption of 99 Mo on hydrous zirconium oxide (HZO) and the separation of sup(99m)Tc, generated by the decay of 99 Mo with saline solution, are analised. The sup(99m)Tc separation yield, pH of the eluted solution, aspect of the elution curve and the adsorption of 99 Mo on hydrous zirconium oxide calcined at 800 0 C are studied. The chemical and radioactive purities of the final product are analysed and the variation of the elution yield for successive elutions is studied. (Author) [pt

Simulating QCD at the physical point with Nf=2 Wilson twisted mass fermions at maximal twist

International Nuclear Information System (INIS)

Abdel-Rehim, A.; Alexandrou, C.; Cyprus Univ. Nicosia; Burger, F.

2015-12-01

We present simulations of QCD using N f =2 dynamical Wilson twisted mass lattice QCD with physical value of the pion mass and at one value of the lattice spacing. Such simulations at a∼0.09 fm became possible by adding the clover term to the action. While O(a) improvement is still guaranteed by Wilson twisted mass fermions at maximal twist, the introduction of the clover term reduces O(a 2 ) cutoff effects related to isospin symmetry breaking. We give results for a set of phenomenologically interesting observables like pseudo-scalar masses and decay constants, quark masses and the anomalous magnetic moments of leptons. We mostly find remarkably good agreement with phenomenology, even though we cannot take the continuum and thermodynamic limits.

Twist-1 Up-Regulation in Carcinoma Correlates to Poor Survival

Directory of Open Access Journals (Sweden)

Alimujiang Wushou

2014-11-01

Full Text Available Epithelial-to-mesenchymal transition (EMT facilitates tumor metastasis. Twist is a basic helix-loop-helix protein that modulates many target genes through E-box-responsive elements. There are two twist-like proteins, Twist-1 and Twist-2, sharing high structural homology in mammals. Twist-1 was found to be a key factor in the promotion of metastasis of cancer cells, and is known to induce EMT. Twist-1 participation in carcinoma progression and metastasis has been reported in a variety of tumors. However, controversy exists concerning the correlation between Twist-1 and prognostic value with respect to carcinoma. A systematic review and meta-analysis were performed to determine whether the expression of Twist-1 was associated with the prognosis of carcinoma patients. This analysis included 17 studies: four studies evaluated lung cancer, three evaluated head and neck cancer, two evaluated breast cancer, two evaluated esophageal cancer, two evaluated liver cancer and one each evaluated osteosarcoma, bladder, cervical and ovarian cancer. A total of 2006 patients were enrolled in these studies, and the median trial sample size was 118 patients. Twist-1 expression was associated with worse overall survival (OS at both 3 years (hazard ratio “HR” for death = 2.13, 95% CI = 1.86 to 2.45, p < 0.001 and 5 years (HR for death = 2.01, 95% CI = 1.76 to 2.29, p < 0.001. Expression of Twist-1 is associated with worse survival in carcinoma.

UPPGHA: Uniform Privacy Preservation Group Handover Authentication Mechanism for mMTC in LTE-A Networks

Directory of Open Access Journals (Sweden)

Jin Cao

2018-01-01

Full Text Available Machine Type Communication (MTC, as one of the most important wireless communication technologies in the future wireless communication, has become the new business growth point of mobile communication network. It is a key point to achieve seamless handovers within Evolved-Universal Terrestrial Radio Access Network (E-UTRAN for massive MTC (mMTC devices in order to support mobility in the Long Term Evolution-Advanced (LTE-A networks. When mMTC devices simultaneously roam from a base station to a new base station, the current handover mechanisms suggested by the Third-Generation Partnership Project (3GPP require several handover signaling interactions, which could cause the signaling load over the access network and the core network. Besides, several distinct handover procedures are proposed for different mobility scenarios, which will increase the system complexity. In this paper, we propose a simple and secure uniform group-based handover authentication scheme for mMTC devices based on the multisignature and aggregate message authentication code (AMAC techniques, which is to fit in with all of the mobility scenarios in the LTE-A networks. Compared with the current 3GPP standards, our scheme can achieve a simple authentication process with robust security protection including privacy preservation and thus avoid signaling congestion. The correctness of the proposed group handover authentication protocol is formally proved in the Canetti-Krawczyk (CK model and verified based on the AVISPA and SPAN.

Euclidean supersymmetry, twisting and topological sigma models

International Nuclear Information System (INIS)

Hull, C.M.; Lindstroem, U.; Santos, L. Melo dos; Zabzine, M.; Unge, R. von

2008-01-01

We discuss two dimensional N-extended supersymmetry in Euclidean signature and its R-symmetry. For N = 2, the R-symmetry is SO(2) x SO(1, 1), so that only an A-twist is possible. To formulate a B-twist, or to construct Euclidean N = 2 models with H-flux so that the target geometry is generalised Kahler, it is necessary to work with a complexification of the sigma models. These issues are related to the obstructions to the existence of non-trivial twisted chiral superfields in Euclidean superspace.

Mean temperature of the catch (MTC in the Greek Seas based on landings and survey data

Directory of Open Access Journals (Sweden)

Athanassios C. Tsikliras

2015-04-01

Full Text Available The mean temperature of the catch (MTC, which is the average inferred temperature preference of the exploited species weighted by their annual catch, is an index that has been used for evaluating the effect of sea warming on marine ecosystems. In the present work, we examined the effect of sea surface temperature on the catch composition of the Greek Seas using the MTC applied on the official catch statistics (landings for the period 1970-2010 (Aegean and Ionian Seas and on experimental bottom trawl survey data for 1997-2014 (southern Aegean Sea. The MTC of the landings for the study period increased from 11.8 οC to 16.2 οC in the Aegean Sea and from 10.0 οC to 14.7 οC in the Ionian Sea. Overall, the rate of MTC increase was 1.01 οC per decade for the Aegean and 1.17 οC per decade for the Ionian Sea and was positively related to sea surface temperature anomalies in both areas. For the survey data, the increase of the MTC of the bottom trawl catch in the southern Aegean Sea was lower (0.51 οC per decade but referred to a shorter time frame and included only demersal species. The change in MTC of official and survey catches indicates that the relative catch proportions of species preferring warmer waters and those preferring colder waters have changed in favour of the former and that this change is linked to sea surface temperature increase, both internally (through the Atlantic Multidecadal Oscillation or externally (warming trend driven.

Oliver Twist

NARCIS (Netherlands)

Dickens, Charles

2005-01-01

Oliver Twist is one of Dickens's most popular novels, with many famous film, television and musical adaptations. It is a classic story of good against evil, packed with humour and pathos, drama and suspense, in which the orphaned Oliver is brought up in a harsh workhouse, and then taken in and

Development of a noise-based method for the determination of the moderator temperature coefficient of reactivity (MTC) in pressurized water reactors (PWRs)

International Nuclear Information System (INIS)

Demaziere, C.

2002-01-01

The Moderator Temperature Coefficient of reactivity (MTC) is an important safety parameter of Pressurized Water Reactors (PWRs). In most countries, the so-called at-power MTC has to be measured a few months before the reactor outage, in order to determine if the MTC will not become too negative. Usually, the at-power MTC is determined by inducing a change in the moderator temperature, which has to be compensated for by other means, such as a change in the boron concentration. An MTC measurement using the boron dilution method is analysed in this thesis. It is demonstrated that the uncertainty of such a measurement technique is so large, that the measured MTC could become more negative than what the Technical Specifications allow. Furthermore, this technique incurs a disturbance of the plant operation. For this reason, another technique relying on noise analysis was proposed a few years ago. In this technique, the MTC is inferred from the neutron noise measured inside the core and the moderator temperature noise measured at the core-exit, in the same or in a neighbouring fuel assembly. This technique does not require any perturbation of the reactor operation, but was nevertheless proven to underestimate the MTC by a factor of 2 to 5. In this thesis, it is shown, both theoretically and experimentally, that the reason of the MTC underestimation by noise analysis is the radially loosely coupled character of the moderator temperature noise throughout the core. A new MTC noise estimator, accounting for this radially non-homogeneous moderator temperature noise is proposed and demonstrated to give the correct MTC value. This new MTC noise estimator relies on the neutron noise measured in a single point of the reactor and the radially averaged moderator temperature noise measured inside the core. In the case of the Ringhals-2 PWR in Sweden, Gamma-Thermometers (GTs) offer such a possibility since in dynamic mode they measure the moderator temperature noise, whereas in static

Duality and braiding in twisted quantum field theory

International Nuclear Information System (INIS)

Riccardi, Mauro; Szabo, Richard J.

2008-01-01

We re-examine various issues surrounding the definition of twisted quantum field theories on flat noncommutative spaces. We propose an interpretation based on nonlocal commutative field redefinitions which clarifies previously observed properties such as the formal equivalence of Green's functions in the noncommutative and commutative theories, causality, and the absence of UV/IR mixing. We use these fields to define the functional integral formulation of twisted quantum field theory. We exploit techniques from braided tensor algebra to argue that the twisted Fock space states of these free fields obey conventional statistics. We support our claims with a detailed analysis of the modifications induced in the presence of background magnetic fields, which induces additional twists by magnetic translation operators and alters the effective noncommutative geometry seen by the twisted quantum fields. When two such field theories are dual to one another, we demonstrate that only our braided physical states are covariant under the duality

Twisted Acceleration-Enlarged Newton-Hooke Hopf Algebras

International Nuclear Information System (INIS)

Daszkiewicz, M.

2010-01-01

Ten Abelian twist deformations of acceleration-enlarged Newton-Hooke Hopf algebra are considered. The corresponding quantum space-times are derived as well. It is demonstrated that their contraction limit τ → ∞ leads to the new twisted acceleration-enlarged Galilei spaces. (author)

Flow cytometry in diagnostic cytology.

Science.gov (United States)

O'Leary, T J

1998-01-01

Flow cytometry (FCM) is a useful adjunct to cytologic examination, because the quantitative biochemical information it provides complements the morphologic information gained during visual examination. It aids in the interpretation of bladder washings, and is particularly useful for the assessment of lymphoid lesions, whether they originate from fine-needle aspiration, cerebrospinal fluid, or effusions. Optimal use of FCM frequently requires assessment of more than one parameter; simultaneous use of cell differentiation markers and nuclear DNA quantitation is often significantly more useful than either alone. Despite the utility of FCM, however, the potential for future development appears to be limited. Improvements in image cytometry allow reasonable assessment of ploidy and S-fraction to be made from specimens prepared on glass slides. Multiparameter measurements may also be accomplished with imaging techniques, which allow the further advantage of visual identification of cells with equivocal morphologic changes. The development of artificial intelligence methods for use with imaging technology has also significantly exceeded that of FCM. Finally, image cytometry is often more useful for samples with few cells. Other challenges are posed by immunocytochemical methods which compete with flow cytometry as tools for assessment of proliferation. Given the relatively high cost of FCM instrumentation, survival of FCM as an ancillary technique in cytopathology will require further technical refinements to offset the advantages currently associated with image cytometry and immunocytochemistry.

Photo-production of (99)Mo/(99m)Tc with electron linear accelerator beam.

Science.gov (United States)

Avagyan, R; Avetisyan, A; Kerobyan, I; Dallakyan, R

2014-09-01

We report on the development of a relatively new method for the production of (99)Mo/(99m)Tc. The method involves the irradiation of natural molybdenum using high-intensity bremsstrahlung photons from the electron beam of the LUE50 linear electron accelerator located at the Yerevan Physics Institute (YerPhi). The production method has been developed and shown to be successful. The linear electron accelerator at YerPhi was upgraded to allow for significant increases of the beam intensity and spatial density. The LUE50 was also instrumented by a remote control system for ease of operation. We have developed and tested the (99m)Tc extraction from the irradiation of natural MoO3. This paper reports on the optimal conditions of our method of (99)Mo production. We show the success of this method with the production and separation of the first usable amounts of (99m)Tc. Copyright © 2014 Elsevier Inc. All rights reserved.

Microfluidic devices and methods for integrated flow cytometry

Science.gov (United States)

Srivastava, Nimisha [Goleta, CA; Singh, Anup K [Danville, CA

2011-08-16

Microfluidic devices and methods for flow cytometry are described. In described examples, various sample handling and preparation steps may be carried out within a same microfluidic device as flow cytometry steps. A combination of imaging and flow cytometry is described. In some examples, spiral microchannels serve as incubation chambers. Examples of automated sample handling and flow cytometry are described.

TWIST1 promotes invasion through mesenchymal change in human glioblastoma

Directory of Open Access Journals (Sweden)

Wakimoto Hiroaki

2010-07-01

Full Text Available Abstract Background Tumor cell invasion into adjacent normal brain is a mesenchymal feature of GBM and a major factor contributing to their dismal outcomes. Therefore, better understandings of mechanisms that promote mesenchymal change in GBM are of great clinical importance to address invasion. We previously showed that the bHLH transcription factor TWIST1 which orchestrates carcinoma metastasis through an epithelial mesenchymal transition (EMT is upregulated in GBM and promotes invasion of the SF767 GBM cell line in vitro. Results To further define TWIST1 functions in GBM we tested the impact of TWIST1 over-expression on invasion in vivo and its impact on gene expression. We found that TWIST1 significantly increased SNB19 and T98G cell line invasion in orthotopic xenotransplants and increased expression of genes in functional categories associated with adhesion, extracellular matrix proteins, cell motility and locomotion, cell migration and actin cytoskeleton organization. Consistent with this TWIST1 reduced cell aggregation, promoted actin cytoskeletal re-organization and enhanced migration and adhesion to fibronectin substrates. Individual genes upregulated by TWIST1 known to promote EMT and/or GBM invasion included SNAI2, MMP2, HGF, FAP and FN1. Distinct from carcinoma EMT, TWIST1 did not generate an E- to N-cadherin "switch" in GBM cell lines. The clinical relevance of putative TWIST target genes SNAI2 and fibroblast activation protein alpha (FAP identified in vitro was confirmed by their highly correlated expression with TWIST1 in 39 human tumors. The potential therapeutic importance of inhibiting TWIST1 was also shown through a decrease in cell invasion in vitro and growth of GBM stem cells. Conclusions Together these studies demonstrated that TWIST1 enhances GBM invasion in concert with mesenchymal change not involving the canonical cadherin switch of carcinoma EMT. Given the recent recognition that mesenchymal change in GBMs is

Technetium 99mTc Pertechnetate Brain Scanning

International Nuclear Information System (INIS)

Rhee, Sang Min; Park, Jin Yung; Lee, Ahn Ki; Chung, Choo Il; Hong, Chang Gi; Rhee, Chong Heon; Koh, Chang Soon

1968-01-01

Technetium 99 mTc pertechnetate brain scanning were performed in 3 cases of head injury (2 chronic subdural hematomas and 1 acute epidural hematoma), 2 cases of brain abscess and 1 case of intracerebral hematoma associated with arteriovenous anomaly. In all the cases brain scintigrams showed 'hot areas.' Literatures on radioisotope scanning of intracranial lesions were briefly reviewed. With the improvement of radioisotope scanner and development of new radiopharmaceuticals brain scanning became a safe and useful screening test for diagnosis of intracranial lesions. Brain scanning can be easily performed even to a moribund patient without any discomfort and risk to the patient which are associated with cerebral angiography or pneumoencephalography. Brain scanning has been useful in diagnosis of brain tumor, brain abscess, subdural hematoma, and cerebral vascular diseases. In 80 to 90% of brain tumors positive scintigrams can be expected. Early studies were done with 203 Hg-Neohydrin or 131 I-serum albumin. With these agents, however, patients receive rather much radiation to the whole body and kidneys. In 1965 Harper introduced 99 mTc to reduce radiation dose to the patient and improve statistical variation in isotope scanning.

Renormalization of quark propagator, vertex functions, and twist-2 operators from twisted-mass lattice QCD at Nf=4

Science.gov (United States)

Blossier, Benoît.; Brinet, Mariane; Guichon, Pierre; Morénas, Vincent; Pène, Olivier; Rodríguez-Quintero, Jose; Zafeiropoulos, Savvas

2015-06-01

We present a precise nonperturbative determination of the renormalization constants in the mass independent RI'-MOM scheme. The lattice implementation uses the Iwasaki gauge action and four degenerate dynamical twisted-mass fermions. The gauge configurations are provided by the ETM Collaboration. Renormalization constants for scalar, pseudoscalar, vector and axial operators, as well as the quark propagator renormalization, are computed at three different values of the lattice spacing, two volumes and several twisted-mass parameters. The method we developed allows for a precise cross-check of the running, thanks to the particular proper treatment of hypercubic artifacts. Results for the twist-2 operator O44 are also presented.

A {sup 99m}Tc Generator using PZC for (n,{gamma}) {sup 99}Mo

Energy Technology Data Exchange (ETDEWEB)

Adang, H G; Mutalib, A; Suparman, I; Hamid,; Purwadi, B; Pancoko, M; Setiowati, S; Yulianti, V; Robertus, D H [Radioisotope Production Center, National Atomic Energy Agency Kawasan PUSPIPTEK, Serpong (Indonesia)

1998-10-01

The high performance adsorbent Poly Zirconium Compound (PZC) was produced by Department of Radioisotope, Japan Atomic Energy Research Institute. This compound was developed as an adsorbent for natural Mo (n,{gamma}) {sup 99}Mo-{sup 99m}Tc Generator. In the present paper, we report the performance of the PZC for a {sup 99m}Tc Generator which was focused on the yield, on elution profile and {sup 99}Mo breakthrough. (author)

Study of the elution {sup 99}Mo-{sup 99m}Tc generators produced at IPEN-CNEN/SP

Energy Technology Data Exchange (ETDEWEB)

Lopes, Paula Regina Corain [Pontificia Univ. Catolica de Sao Paulo, SP (Brazil); Instituto de Pesquisas Energeticas e Nucleares IPEN/CNEN-SP, Sao Paulo, SP (Brazil)]. E-mail: corain.lopes@uol.com.br; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: jaosso@ipen.br

2007-07-01

Over the last years {sup 99m}Tc has become a very important asset in modern nuclear medicine, due to the emission of gamma ray of optimal energy (140 keV) and a suitable half-life (6.04 h). A further attribute of {sup 99m}Tc is its formation from the decay of {sup 99}Mo and the availability from {sup 99}Mo-{sup 99m}Tc generator systems. The most common and practical generator types consist of a chromatographic column packed with aluminium oxide, onto which the highly purified fission product {sup 99}Mo (imported from Canada) is adsorbed in the form of molybdate. {sup 99m}Tc is further eluted with saline solution. The objective of this work is to study the performance and the elution profile of {sup 99m}Tc from high activity generators in order to decrease molybdenum and aluminium concentration. The experiments involved the use of paper filters and Sep Pak columns and also the changing in the time interval between elutions. {sup 99}Mo breakthrough was measured using a dose calibrator and aluminium by UV-Vis spectrophotometry. The best results were achieved using a Sep Pak column containing neutral aluminium oxide. (author)

Twisting the N=2 string

International Nuclear Information System (INIS)

Ketov, S.V.; Lechtenfeld, O.; Parkes, A.J.

1993-12-01

The most general homogeneous monodromy conditions in N= 2 string theory are classified in terms of the conjugacy classes of the global symmetry group U(1, 1) x Z 2 . For classes which generate a discrete subgroup Γ, the corresponding target space backgrounds C 1,1 /Γ include half spaces, complex orbifolds and tori. We propose a generalization of the intercept formula to matrix-valued twists, and find massless physical states in a number of twisted cases. In particular, the sixteen Z 2 -twisted sectors of the N = 2 string are investigated, and the corresponding ground states are identified via bosonization and BRST cohomology. We find enough room for an extended multiplet of 'spacetime' supersymmetry, with the number of supersymmetries being dependent on global 'spacetime' topology. Unfortunately, world-sheet locality for the chiral vertex operators does not permit interactions for the massless 'spacetime' fermions; however possibly, an asymmetric GSO projection could evade this problem. (orig.)

Development of 99mTc agents for imaging central neural system receptors

International Nuclear Information System (INIS)

2004-01-01

Radiopharmaceuticals that bind to central neural system (CNS) receptors in vivo are potentially useful for understanding the pathophysiology of anumber of neurological and psychiatric disorders, their diagnosis and treatment. Carbon-11 labelled compounds and positron emission tomography(PET) imaging have played a vital role in establishing the usefulness of imaging the dopaminergic, cholinergic, serotonergic and benzodiazapine receptors, and relating the receptor density to disease status. Since the use of 11C agents is constrained due to their 20 min half-life, various radiohalogenated analogues based on the structure of 11C compounds have been successfully developed, providing comparable information. Iodine- 123 is the most widely employed of these radioisotopes; it has a longer, 13 h, half-life. Through the use of 123I, there has been a steady growth in CNS receptor imaging studies employing single photon emission computerized tomography (SPECT). SPECT, as compared with PET, has slightly inferior image resolution but has the advantage of being readily available worldwide. However, the 123I radiopharmaceutical is expensive and the distribution system outside of the major markets is not well developed for its supply on a routine basis. The ideal radioisotope for SPECT imaging is 99mTc, due to its low cost per dose, availability through commercially available generator systems and physical decay characteristics. Over 80% of all diagnostic nuclear medicine imaging studies worldwide are conducted using this radioisotope. Development of 99mTc radiopharmaceuticals for imaging CNS receptors is therefore of considerable importance. On the basis of the recommendations of a consultants meeting, the International Atomic Energy Agency (IAEA) initiated in 1996 a Co-ordinated Research Project (CRP) on Development of Agents for Imaging CNS Receptors based on 99mTc. At that time there were no 99mTc CNS receptor imaging radiopharmaceuticals available even though work on

Scanning tunneling microscopy and spectroscopy of twisted trilayer graphene

Science.gov (United States)

Zuo, Wei-Jie; Qiao, Jia-Bin; Ma, Dong-Lin; Yin, Long-Jing; Sun, Gan; Zhang, Jun-Yang; Guan, Li-Yang; He, Lin

2018-01-01

Twist, as a simple and unique degree of freedom, could lead to enormous novel quantum phenomena in bilayer graphene. A small rotation angle introduces low-energy van Hove singularities (VHSs) approaching the Fermi level, which result in unusual correlated states in the bilayer graphene. It is reasonable to expect that the twist could also affect the electronic properties of few-layer graphene dramatically. However, such an issue has remained experimentally elusive. Here, by using scanning tunneling microscopy/spectroscopy (STM/STS), we systematically studied a twisted trilayer graphene (TTG) with two different small twist angles between adjacent layers. Two sets of VHSs, originating from the two twist angles, were observed in the TTG, indicating that the TTG could be simply regarded as a combination of two different twisted bilayers of graphene. By using high-resolution STS, we observed a split of the VHSs and directly imaged the spatial symmetry breaking of electronic states around the VHSs. These results suggest that electron-electron interactions play an important role in affecting the electronic properties of graphene systems with low-energy VHSs.

Twisted boundary states in c=1 coset conformal field theories

International Nuclear Information System (INIS)

Ishikawa, Hiroshi; Yamaguchi, Atsushi

2003-01-01

We study the mutual consistency of twisted boundary conditions in the coset conformal field theory G/H. We calculate the overlap of the twisted boundary states of G/H with the untwisted ones, and show that the twisted boundary states are consistently defined in the charge-conjugation modular invariant. The overlap of the twisted boundary states is expressed by the branching functions of a twisted affine Lie algebra. As a check of our argument, we study the diagonal coset theory so(2n) 1 +so(2n) 1 /so(2n) 2 , which is equivalent to the orbifold S 1 /Z 2 at a particular radius. We construct the boundary states twisted by the automorphisms of the unextended Dynkin diagram of so(2n), and show their mutual consistency by identifying their counterpart in the orbifold. For the triality of so(8), the twisted states of the coset theory correspond to neither the Neumann nor the Dirichlet boundary states of the orbifold and yield conformal boundary states that preserve only the Virasoro algebra. (author)

Twisted covariant noncommutative self-dual gravity

International Nuclear Information System (INIS)

Estrada-Jimenez, S.; Garcia-Compean, H.; Obregon, O.; Ramirez, C.

2008-01-01

A twisted covariant formulation of noncommutative self-dual gravity is presented. The formulation for constructing twisted noncommutative Yang-Mills theories is used. It is shown that the noncommutative torsion is solved at any order of the θ expansion in terms of the tetrad and some extra fields of the theory. In the process the first order expansion in θ for the Plebanski action is explicitly obtained.

Soft tissue twisting injuries of the knee

International Nuclear Information System (INIS)

Magee, T.; Shapiro, M.

2001-01-01

Twisting injuries occur as a result of differential motion of different tissue types in injuries with some rotational force. These injuries are well described in brain injuries but, to our knowledge, have not been described in the musculoskeletal literature. We correlated the clinical examination and MR findings of 20 patients with twisting injuries of the soft tissues around the knee. Design and patients: We prospectively followed the clinical courses of 20 patients with knee injuries who had clinical histories and MR findings to suggest twisting injuries of the subcutaneous tissues. Patients with associated internal derangement of the knee (i.e., meniscal tears, ligamentous or bone injuries) were excluded from this study. MR findings to suggest twisting injuries included linear areas of abnormal dark signal on T1-weighted sequences and abnormal bright signal on T2-weighted or short tau inversion recovery (STIR) sequences and/or signal to suggest hemorrhage within the subcutaneous tissues. These MR criteria were adapted from those established for indirect musculotendinous junction injuries. Results: All 20 patients presented with considerable pain that suggested internal derangement on physical examination by the referring orthopedic surgeons. All presented with injuries associated with rotational force. The patients were placed on a course of protected weight-bearing of the affected extremity for 4 weeks. All patients had pain relief by clinical examination after this period of protected weight-bearing. Twisting injuries of the soft tissues can result in considerable pain that can be confused with internal derangement of the knee on physical examination. Soft tissue twisting injuries need to be recognized on MR examinations as they may be the cause of the patient's pain despite no MR evidence of internal derangement of the knee. The demonstration of soft tissue twisting injuries in a patient with severe knee pain but no documented internal derangement on MR

Prostacyclin Suppresses Twist Expression in the Presence of Indomethacin in Bone Marrow-Derived Mesenchymal Stromal Cells

Science.gov (United States)

Kemper, Oliver; Herten, Monika; Fischer, Johannes; Haversath, Marcel; Beck, Sascha; Classen, Tim; Warwas, Sebastian; Tassemeier, Tjark; Landgraeber, Stefan; Lensing-Höhn, Sabine; Krauspe, Rüdiger; Jäger, Marcus

2014-01-01

Background Iloprost, a stable prostacyclin I2 analogue, seems to have an osteoblast-protective potential, whereas indomethacin suppresses new bone formation. The aim of this study was to investigate human bone marrow stromal cell (BMSC) proliferation and differentiation towards the osteoblastic lineage by administration of indomethacin and/or iloprost. Material/Methods Human bone marrow cells were obtained from 3 different donors (A=26 yrs/m; B=25 yrs/f, C=35 yrs/m) via vacuum aspiration of the iliac crest followed by density gradient centrifugation and flow cytometry with defined antigens (CD105+/73+/45−/14−). The cells were seeded and incubated as follows: without additives (Group 0; donor A/B/C), with 10−7 M iloprost only (Group 0+ilo; A/B), with indomethacin only in concentrations of 10−6 M (Group 1, A), 10−5 M (Group 2, B), 10−4 M (Group 3, A/B), and together with 10−7 M iloprost (Groups 4–6, A/B/C). On Day 10 and 28, UV/Vis spectrometric and immunocytochemical assays (4 samples per group and donor) were performed to investigate cell proliferation (cell count measurement) and differentiation towards the osteoblastic lineage (CD34−, CD45−, CD105+, type 1 collagen (Col1), osteocalcin (OC), alkaline phosphatase (ALP), Runx2, Twist, specific ALP-activity). Results Indomethacin alone suppressed BMSC differentiation towards the osteoblastic lineage by downregulation of Runx2, Col1, and ALP. In combination with indomethacin, iloprost increased cell proliferation and differentiation and it completely suppressed Twist expression at Day 10 and 28. Iloprost alone did not promote cell proliferation, but moderately enhanced Runx2 and Twist expression. However, the proliferative effects and the specific ALP-activity varied donor-dependently. Conclusions Iloprost partially antagonized the suppressing effects of indomethacin on BMSC differentiation towards the osteoblast lineage. It enhanced the expression of Runx2 and, only in the presence of indomethacin

Reaction mechanism of the acidic hydrolysis of highly twisted amides: Rate acceleration caused by the twist of the amide bond.

Science.gov (United States)

Mujika, Jon I; Formoso, Elena; Mercero, Jose M; Lopez, Xabier

2006-08-03

We present an ab initio study of the acid hydrolysis of a highly twisted amide and a planar amide analogue. The aim of these studies is to investigate the effect that the twist of the amide bond has on the reaction barriers and mechanism of acid hydrolysis. Concerted and stepwise mechanisms were investigated using density functional theory and polarizable continuum model calculations. Remarkable differences were observed between the mechanism of twisted and planar amide, due mainly to the preference for N-protonation of the former and O-protonation of the latter. In addition, we were also able to determine that the hydrolytic mechanism of the twisted amide will be pH dependent. Thus, there is a preference for a stepwise mechanism with formation of an intermediate in the acid hydrolysis, whereas the neutral hydrolysis undergoes a concerted-type mechanism. There is a nice agreement between the characterized intermediate and available X-ray data and a good agreement with the kinetically estimated rate acceleration of hydrolysis with respect to analogous undistorted amide compounds. This work, along with previous ab initio calculations, describes a complex and rich chemistry for the hydrolysis of highly twisted amides as a function of pH. The theoretical data provided will allow for a better understanding of the available kinetic data of the rate acceleration of amides upon twisting and the relation of the observed rate acceleration with intrinsic differential reactivity upon loss of amide bond resonance.

A twisted generalization of Novikov-Poisson algebras

OpenAIRE

Yau, Donald

2010-01-01

Hom-Novikov-Poisson algebras, which are twisted generalizations of Novikov-Poisson algebras, are studied. Hom-Novikov-Poisson algebras are shown to be closed under tensor products and several kinds of twistings. Necessary and sufficient conditions are given under which Hom-Novikov-Poisson algebras give rise to Hom-Poisson algebras.

Introduction to twisted conformal fields

International Nuclear Information System (INIS)

Kazama, Y.

1988-01-01

A pedagogical account is given of the recent developments in the theory of twisted conformal fields. Among other things, the main part of the lecture concerns the construction of the twist-emission vertex operator, which is a generalization of the fermion emission vertex in the superstring theory. Several different forms of the vertex are derived and their mutural relationships are clarified. In this paper, the authors include a brief survey of the history of the fermion emission vertex, as it offers a good perspective in which to appreciate the logical development

CytometryML: a markup language for analytical cytology

Science.gov (United States)

Leif, Robert C.; Leif, Stephanie H.; Leif, Suzanne B.

2003-06-01

Cytometry Markup Language, CytometryML, is a proposed new analytical cytology data standard. CytometryML is a set of XML schemas for encoding both flow cytometry and digital microscopy text based data types. CytometryML schemas reference both DICOM (Digital Imaging and Communications in Medicine) codes and FCS keywords. These schemas provide representations for the keywords in FCS 3.0 and will soon include DICOM microscopic image data. Flow Cytometry Standard (FCS) list-mode has been mapped to the DICOM Waveform Information Object. A preliminary version of a list mode binary data type, which does not presently exist in DICOM, has been designed. This binary type is required to enhance the storage and transmission of flow cytometry and digital microscopy data. Index files based on Waveform indices will be used to rapidly locate the cells present in individual subsets. DICOM has the advantage of employing standard file types, TIF and JPEG, for Digital Microscopy. Using an XML schema based representation means that standard commercial software packages such as Excel and MathCad can be used to analyze, display, and store analytical cytometry data. Furthermore, by providing one standard for both DICOM data and analytical cytology data, it eliminates the need to create and maintain special purpose interfaces for analytical cytology data thereby integrating the data into the larger DICOM and other clinical communities. A draft version of CytometryML is available at www.newportinstruments.com.

On the performance analysis of Savonius rotor with twisted blades

Energy Technology Data Exchange (ETDEWEB)

Saha, U.K.; Rajkumar, M. Jaya [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati-781 039 (India)

2006-09-15

The present investigation is aimed at exploring the feasibility of twisted bladed Savonius rotor for power generation. The twisted blade in a three-bladed rotor system has been tested in a low speed wind tunnel, and its performance has been compared with conventional semicircular blades (with twist angle of 0{sup o}). Performance analysis has been made on the basis of starting characteristics, static torque and rotational speed. Experimental evidence shows the potential of the twisted bladed rotor in terms of smooth running, higher efficiency and self-starting capability as compared to that of the conventional bladed rotor. Further experiments have been conducted in the same setup to optimize the twist angle. (author)

New look at the dynamics of twisted accretion disks

International Nuclear Information System (INIS)

Hatchett, S.P.; Begelman, M.C.; Sarazin, C.L.

1981-01-01

We reexamine the dynamic response of a thin, accretion disk to twisting torques, guided by the earlier analyses by Bardeen and Petterson. We make several corrections to this earlier work, and present a new version of the twist equations consistent with their physical assumptions. By describing the distortion of the disk in terms Cartesian direction cosines rather than the Euler angles used by the earlier authors, we are able to transform the twist equations from a pair of coupled, nonlinear, partial differential equations to a single, linear, complex one. We write down formulae for the external twisting torques likley to be encountered in astrophysic, and we show that even with these driving torques our twist equation remains linear. We find exact, analytic solutions for steady state structure of a disk subject to Lense-Thirring torques by a nonaligned central Kerr black hole and also for the time-dependent problem of the structure of a slaved disk with its oscillating boundary conditions. Finally, we discuss the stability of disks against twisting modes and show that undriven disks and disks subject to time-independent driving torques are stable

Reversible Twisting of Primary Amides via Ground State N-C(O) Destabilization: Highly Twisted Rotationally Inverted Acyclic Amides.

Science.gov (United States)

Meng, Guangrong; Shi, Shicheng; Lalancette, Roger; Szostak, Roman; Szostak, Michal

2018-01-17

Since the seminal studies by Pauling in 1930s, planarity has become the defining characteristic of the amide bond. Planarity of amides has central implications for the reactivity and chemical properties of amides of relevance to a range of chemical disciplines. While the vast majority of amides are planar, nonplanarity has a profound effect on the properties of the amide bond, with the most common method to restrict the amide bond relying on the incorporation of the amide function into a rigid cyclic ring system. In a major departure from this concept, here, we report the first class of acyclic twisted amides that can be prepared, reversibly, from common primary amides in a single, operationally trivial step. Di-tert-butoxycarbonylation of the amide nitrogen atom yields twisted amides in which the amide bond exhibits nearly perpendicular twist. Full structural characterization of a range of electronically diverse compounds from this new class of twisted amides is reported. Through reactivity studies we demonstrate unusual properties of the amide bond, wherein selective cleavage of the amide bond can be achieved by a judicious choice of the reaction conditions. Through computational studies we evaluate structural and energetic details pertaining to the amide bond deformation. The ability to selectively twist common primary amides, in a reversible manner, has important implications for the design and application of the amide bond nonplanarity in structural chemistry, biochemistry and organic synthesis.

Modal properties and stability of bend–twist coupled wind turbine blades

Directory of Open Access Journals (Sweden)

A. R. Stäblein

2017-06-01

Full Text Available Coupling between bending and twist has a significant influence on the aeroelastic response of wind turbine blades. The coupling can arise from the blade geometry (e.g. sweep, prebending, or deflection under load or from the anisotropic properties of the blade material. Bend–twist coupling can be utilized to reduce the fatigue loads of wind turbine blades. In this study the effects of material-based coupling on the aeroelastic modal properties and stability limits of the DTU 10 MW Reference Wind Turbine are investigated. The modal properties are determined by means of eigenvalue analysis around a steady-state equilibrium using the aero-servo-elastic tool HAWCStab2 which has been extended by a beam element that allows for fully coupled cross-sectional properties. Bend–twist coupling is introduced in the cross-sectional stiffness matrix by means of coupling coefficients that introduce twist for flapwise (flap–twist coupling or edgewise (edge–twist coupling bending. Edge–twist coupling can increase or decrease the damping of the edgewise mode relative to the reference blade, depending on the operational condition of the turbine. Edge–twist to feather coupling for edgewise deflection towards the leading edge reduces the inflow speed at which the blade becomes unstable. Flap–twist to feather coupling for flapwise deflections towards the suction side increase the frequency and reduce damping of the flapwise mode. Flap–twist to stall reduces frequency and increases damping. The reduction of blade root flapwise and tower bottom fore–aft moments due to variations in mean wind speed of a flap–twist to feather blade are confirmed by frequency response functions.

Twisted sigma-model solitons on the quantum projective line

Science.gov (United States)

Landi, Giovanni

2018-04-01

On the configuration space of projections in a noncommutative algebra, and for an automorphism of the algebra, we use a twisted Hochschild cocycle for an action functional and a twisted cyclic cocycle for a topological term. The latter is Hochschild-cohomologous to the former and positivity in twisted Hochschild cohomology results into a lower bound for the action functional. While the equations for the critical points are rather involved, the use of the positivity and the bound by the topological term lead to self-duality equations (thus yielding twisted noncommutative sigma-model solitons, or instantons). We present explicit nontrivial solutions on the quantum projective line.

Diversification in the Supply Chain of (99)Mo Ensures a Future for (99m)Tc.

Science.gov (United States)

Cutler, Cathy S; Schwarz, Sally W

2014-07-01

The uncertain availability of (99m)Tc has become a concern for nuclear medicine departments across the globe. An issue for the United States is that currently it is dependent on a supply of (99m)Tc (from (99)Mo) that is derived solely by production outside the United States. Since the United States uses half the world's (99)Mo production, the U.S. (99)Mo supply chain would be greatly enhanced if a producer were located within the United States. The fragility of the old (99)Mo supply chain is being addressed as new facilities are constructed and new processes are developed to produce (99)Mo without highly enriched uranium. The conversion to low-enriched uranium is necessary to minimize the potential misuse of highly enriched uranium in the world for nonpeaceful means. New production facilities, new methods for the production of (99)Mo, and a new generator elution system for the supply of (99m)Tc are currently being pursued. The progress made in all these areas will be discussed, as they all highlight the need to embrace diversity to ensure that we have a robust and reliable supply of (99m)Tc in the future. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

A Survey of Agreement Rate between Simple MTC and Post Contrast T1 Sequence MRI for Diagnosing Active Multiple Sclerosis Plaques

Directory of Open Access Journals (Sweden)

N. Farshchian

2016-07-01

Full Text Available Introduction & Objective: MS is the most common disabling neurological disorder. Identifying new active MS plaques at the onset and clinical status and faster onset of treatment as well as evaluating the response to treatment is important and MRI with contrast is the best indicator for these measures. Materials & Methods: This study was cross-sectional including 62 patients with diagnosed MS. Whose clinical symptoms suggested the recurrence of MS. They were referred to the radiol-ogy department to undergo brain MRI with injection for the diagnosis of active plaques by a neurologist,The Data were analyzed using statistical tests and SPSS 21 software. Results: Based on the sequences of post contrast T1, pre contrast MTC and post contrast MTC 74, 272 and 271 plaques were respectively discovered. Detection of active MS plaques on T1 sequences after injection were in poor accordance and had significant difference with MTC before and after injection. Moreover, detection of active MS plaques on MTC sequences be-fore injection were in good accordance and did not show significant difference with MTC se-quences after injection. Conclusion: Based on these results, it seems that the purpose of MRI in MS patients is deter-mining the amount of active plaques. Sequences of pre contrast and post contrast MTC are significantly more than sequences of post contrast T1. Therefore, using sequences of MTC can be helpful in MRI. (Sci J Hamadan Univ Med Sci 2016; 23 (2:97-102

A higher twist correction to heavy quark production

International Nuclear Information System (INIS)

Brodsky, S.J.; Gunion, J.F.; Soper, D.E.

1987-06-01

The leading twist prediction for heavy quark production and a model for a higher twist correction that may be important for charm production was discussed. The correction arises from the interaction of the charm quark with spectator quarks

The Twist Tensor Nuclear Norm for Video Completion.

Science.gov (United States)

Hu, Wenrui; Tao, Dacheng; Zhang, Wensheng; Xie, Yuan; Yang, Yehui

2017-12-01

In this paper, we propose a new low-rank tensor model based on the circulant algebra, namely, twist tensor nuclear norm (t-TNN). The twist tensor denotes a three-way tensor representation to laterally store 2-D data slices in order. On one hand, t-TNN convexly relaxes the tensor multirank of the twist tensor in the Fourier domain, which allows an efficient computation using fast Fourier transform. On the other, t-TNN is equal to the nuclear norm of block circulant matricization of the twist tensor in the original domain, which extends the traditional matrix nuclear norm in a block circulant way. We test the t-TNN model on a video completion application that aims to fill missing values and the experiment results validate its effectiveness, especially when dealing with video recorded by a nonstationary panning camera. The block circulant matricization of the twist tensor can be transformed into a circulant block representation with nuclear norm invariance. This representation, after transformation, exploits the horizontal translation relationship between the frames in a video, and endows the t-TNN model with a more powerful ability to reconstruct panning videos than the existing state-of-the-art low-rank models.

An introduction to mass cytometry: fundamentals and applications.

Science.gov (United States)

Tanner, Scott D; Baranov, Vladimir I; Ornatsky, Olga I; Bandura, Dmitry R; George, Thaddeus C

2013-05-01

Mass cytometry addresses the analytical challenges of polychromatic flow cytometry by using metal atoms as tags rather than fluorophores and atomic mass spectrometry as the detector rather than photon optics. The many available enriched stable isotopes of the transition elements can provide up to 100 distinguishable reporting tags, which can be measured simultaneously because of the essential independence of detection provided by the mass spectrometer. We discuss the adaptation of traditional inductively coupled plasma mass spectrometry to cytometry applications. We focus on the generation of cytometry-compatible data and on approaches to unsupervised multivariate clustering analysis. Finally, we provide a high-level review of some recent benchmark reports that highlight the potential for massively multi-parameter mass cytometry.

Optical yarn assessment system for twist measurement in rotor-spun yarn

International Nuclear Information System (INIS)

Jhatial, R.A.

2015-01-01

This paper presents the development of an optical yarn assessment system for evaluation of twist and structure of twisted yarn. The system comprises a yarn carriage unit, a video microscope and a personal computer. This system was used in conjunction with the well-known tracer fibre technique. This system enables digital images to be grabbed and continuous movies of the yarn to be recorded in order to facilitate the measurement of twist and the analysis of yarn structure. Yarn samples from polyester, viscose and cotton with 35 tex and 485 turns/meter were spun from the roving with 2.3% of black fibres on the SKF laboratory ring frame. In order to measure the twist in the rotor yarns with the optical yarn assessment system, a set of yarn samples from same fibres were spun on RU 14 rotor machine with 35 tex and 475 turns/meter. The twist was measured with the optical yarn assessment system and sixty tests of each sample were carried out on the Zweigle D301. It is clear from the results that there is consistency in the twist of ring-spun yarn measured by the optical yarn assessment system. However, the measured twist with the Zwiegle D301 is inconsistent in the different yarns. The difference in the mean twist measured with the optical twist measuring system and the double untwist-twist method was not significant at a 5% probability level when data was analyzed with t test by using SPSS (Statistical Package for Social Sciences). (author)

Level-rank duality of untwisted and twisted D-branes

International Nuclear Information System (INIS)

Naculich, Stephen G.; Schnitzer, Howard J.

2006-01-01

Level-rank duality of untwisted and twisted D-branes of WZW models is explored. We derive the relation between D0-brane charges of level-rank dual untwisted D-branes of su-bar (N) K and sp-bar (n) k , and of level-rank dual twisted D-branes of su-bar (2n+1) 2k+1 . The analysis of level-rank duality of twisted D-branes of su-bar (2n+1) 2k+1 is facilitated by their close relation to untwisted D-branes of sp-bar (n) k . We also demonstrate level-rank duality of the spectrum of an open string stretched between untwisted or twisted D-branes in each of these cases

Bound states on the lattice with partially twisted boundary conditions

International Nuclear Information System (INIS)

Agadjanov, D.; Guo, F.-K.; Ríos, G.; Rusetsky, A.

2015-01-01

We propose a method to study the nature of exotic hadrons by determining the wave function renormalization constant Z from lattice simulations. It is shown that, instead of studying the volume-dependence of the spectrum, one may investigate the dependence of the spectrum on the twisting angle, imposing twisted boundary conditions on the fermion fields on the lattice. In certain cases, e.g., the case of the DK bound state which is addressed in detail, it is demonstrated that the partial twisting is equivalent to the full twisting up to exponentially small corrections.

Simultaneous quantification of MTC-220 and its metabolites in beagle dog plasma by liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Liu, Xin; Zhao, Manman; Mi, Jiaqi; Liu, Zhihao; Hu, Jinping; Sheng, Li; Wang, Baolian; Li, Dan; Yang, Shuang; Li, Yan

2014-10-01

A sensitive LC-ESI-MS/MS method for simultaneous determination of MTC-220 and its metabolites (paclitaxel and MDA-linker) in dog plasma has been developed and validated. After addition of docetaxel (internal standard), plasma samples containing MTC-220, paclitaxel and MDA-linker were prepared based on a simple protein precipitation by adding two volumes of acetonitrile. The separation was performed on a ZorbaxSB-C18 column (3.5μm, 2.1mm×100mm) at a flow rate of 0.2ml/min, using acetonitrile/water containing 0.1% formic acid (v/v) as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization (ESI) by selected reaction monitoring (SRM). The MS/MS ion transit ions monitored were 1444.4→623.8 for MTC-220, 876.4→307.9 for paclitaxel, 631.2→531.2 for MDA-linker and 830.2→549.1 for the internal standard. Linear detection responses were obtained for MTC-220, paclitaxel and MDA-linker ranging from 10 to 5000, 5 to 2500 and 5 to 500ng/ml, respectively. The lower limits of quantitation (LLOQs) for MTC-220, paclitaxel and MDA-linker were 10, 5 and 5ng/ml, respectively. The intra-day and inter-day precisions (RSD, %) of the three analytes do not exceed 10.9% except for LLOQs (≤17.50), and the accuracy (RE, %) were within ±17.5% for LLOQs and ±12.6% for the others. The average recoveries of three compounds were greater than 85.0%. The analytes were proved to be stable during all sample storage, preparation and analytic procedures. The validated method was successfully applied to pharmacokinetic studies of MTC-220 and its metabolites in beagle dogs after intravenous infusion of MTC-220 at 2.5mg/kg. Copyright © 2014 Elsevier B.V. All rights reserved.

Flow Cytometry Section

Data.gov (United States)

Federal Laboratory Consortium — The primary goal of the Flow Cytometry Section is to provide the services of state-of-the-art multi-parameter cellular analysis and cell sorting for researchers and...

Detecting fetomaternal hemorrhage by flow cytometry

DEFF Research Database (Denmark)

Dziegiel, Morten Hanefeld; Nielsen, Leif Kofoed; Berkowicz, Adela

2006-01-01

The aim of this review is to summarize the most recent developments in the area of detection of fetomaternal hemorrhage by flow cytometry.......The aim of this review is to summarize the most recent developments in the area of detection of fetomaternal hemorrhage by flow cytometry....

Comparative uptake of 67Ga and /sup 99m/Tc MDP in rabbits with a benign noninfected bone lesion (fracture)

International Nuclear Information System (INIS)

Bushberg, J.T.; Hoffer, P.B.; Schreiber, G.J.; Lawson, A.J.; Lawson, J.P.; Lord, P.

1985-01-01

Mid-shaft fractures of the radius and ulna were produced in 3 to 4 kg New Zealand white rabbits and quantitative uptake of /sup 99m/Tc MDP and 67 Ga determined at 11, 18, 25, 32, 51, and 78 days following fracture. Two hundred microCi of 67 Ga was administered 24 hours prior to sacrifice and 1.5 mCi /sup 99m/Tc MDP 2 hours prior to sacrifice. Specific activity ratios (SARs) were determined between fracture and control sides for bone, muscle and skin. SARs for bone were surprisingly similar for /sup 99m/Tc MDP and 67 Ga, reaching peak values of 6.07 +/- 0.64 (/sup 99m/Tc 18 days); 6.58 +/- 0.90 ( 67 Ga 32 days), subsequently decreasing to minimum values at 78 days postfracture (/sup 99m/Tc MDP 2.25 +/- 0.14; 67 Ga 2.18 +/- 0.08). There was no statistically significant difference in SAR for /sup 99m/Tc MDP vs. 67 Ga in bone at any time after fracture. Whole sections of limb were resected on selected animals and activity ratios determined for these sections as a function of the contribution of activity from the various tissues in the volume of interest. Total activity ratios of 67 Ga were lower than bone SARs as a result of the contribution of activity from muscle and skin. Thus, the apparent lower activity ratios noted on 67 Ga images compared with /sup 99m/Tc MDP images in this fracture model were not due to differences in bone SARs but rather due to the higher soft tissue background activity contribution in the 67 Ga images

CytometryML and other data formats

Science.gov (United States)

Leif, Robert C.

2006-02-01

Cytology automation and research will be enhanced by the creation of a common data format. This data format would provide the pathology and research communities with a uniform way for annotating and exchanging images, flow cytometry, and associated data. This specification and/or standard will include descriptions of the acquisition device, staining, the binary representations of the image and list-mode data, the measurements derived from the image and/or the list-mode data, and descriptors for clinical/pathology and research. An international, vendor-supported, non-proprietary specification will allow pathologists, researchers, and companies to develop and use image capture/analysis software, as well as list-mode analysis software, without worrying about incompatibilities between proprietary vendor formats. Presently, efforts to create specifications and/or descriptions of these formats include the Laboratory Digital Imaging Project (LDIP) Data Exchange Specification; extensions to the Digital Imaging and Communications in Medicine (DICOM); Open Microscopy Environment (OME); Flowcyt, an extension to the present Flow Cytometry Standard (FCS); and CytometryML. The feasibility of creating a common data specification for digital microscopy and flow cytometry in a manner consistent with its use for medical devices and interoperability with both hospital information and picture archiving systems has been demonstrated by the creation of the CytometryML schemas. The feasibility of creating a software system for digital microscopy has been demonstrated by the OME. CytometryML consists of schemas that describe instruments and their measurements. These instruments include digital microscopes and flow cytometers. Optical components including the instruments' excitation and emission parts are described. The description of the measurements made by these instruments includes the tagged molecule, data acquisition subsystem, and the format of the list-mode and/or image data. Many

OAM mode converter in twisted fibers

DEFF Research Database (Denmark)

Usuga Castaneda, Mario A.; Beltran-Mejia, Felipe; Cordeiro, Cristiano

2014-01-01

We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA.......We analyze the case of an OAM mode converter based on a twisted fiber, through finite element simulations where we exploit an equivalence between geometric and material transformations. The obtained converter has potential applications in MDM. © 2014 OSA....

Twisting perturbed parafermions

Directory of Open Access Journals (Sweden)

A.V. Belitsky

2017-07-01

Full Text Available The near-collinear expansion of scattering amplitudes in maximally supersymmetric Yang–Mills theory at strong coupling is governed by the dynamics of stings propagating on the five sphere. The pentagon transitions in the operator product expansion which systematize the series get reformulated in terms of matrix elements of branch-point twist operators in the two-dimensional O(6 nonlinear sigma model. The facts that the latter is an asymptotically free field theory and that there exists no local realization of twist fields prevents one from explicit calculation of their scaling dimensions and operator product expansion coefficients. This complication is bypassed making use of the equivalence of the sigma model to the infinite-level limit of WZNW models perturbed by current–current interactions, such that one can use conformal symmetry and conformal perturbation theory for systematic calculations. Presently, to set up the formalism, we consider the O(3 sigma model which is reformulated as perturbed parafermions.

Twisted Vanes Would Enhance Fuel/Air Mixing In Turbines

Science.gov (United States)

Nguyen, H. Lee; Micklow, Gerald J.; Dogra, Anju S.

1994-01-01

Computations of flow show performance of high-shear airblast fuel injector in gas-turbine engine enhanced by use of appropriately proportioned twisted (instead of flat) dome swirl vanes. Resultant more nearly uniform fuel/air mixture burns more efficiently, emitting smaller amounts of nitrogen oxides. Twisted-vane high-shear airblast injectors also incorporated into paint sprayers, providing advantages of low pressure drop characteristic of airblast injectors in general and finer atomization of advanced twisted-blade design.

Comparison of split double and triple twists in pair figure skating.

Science.gov (United States)

King, Deborah L; Smith, Sarah L; Brown, Michele R; McCrory, Jean L; Munkasy, Barry A; Scheirman, Gary I

2008-05-01

In this study, we compared the kinematic variables of the split triple twist with those of the split double twist to help coaches and scientists understand these landmark pair skating skills. High-speed video was taken during the pair short and free programmes at the 2002 Salt Lake City Winter Olympics and the 2003 International Skating Union Grand Prix Finals. Three-dimensional analyses of 14 split double twists and 15 split triple twists from eleven pairs were completed. In spite of considerable variability in the performance variables among the pairs, the main difference between the split double twists and split triple twists was an increase in rotational rate. While eight of the eleven pairs relied primarily on an increased rotational rate to complete the split triple twist, three pairs employed a combined strategy of increased rotational rate and increased flight time due predominantly to delayed or lower catches. These results were similar to observations of jumps in singles skating for which the extra rotation is typically due to an increase in rotational velocity; increases in flight time come primarily from delayed landings as opposed to additional height during flight. Combining an increase in flight time and rotational rate may be a good strategy for completing the split triple twist in pair skating.

/sup 99m/Tc dextran: a new blood-pool-labeling agent for radionuclide angiocardiography

International Nuclear Information System (INIS)

Henze, E.; Robinson, G.D.; Kuhl, D.E.; Schelbert, H.R.

1982-01-01

We have explored the possibility of imaging the cardiac blood pool with dextran (Dx) labeled with /sup 99m/Tc (Tc) after Sn2+ reduction. Stannous dextran (SnDx) kits were prepared in advance and labeling was performed by adding /sup 99m/Tc. The labeling efficiency was greater than 95%. /sup 99m/Tc dextran (TcDx) was highly stable both in vivo and in vitro. In seven dogs we compared the quality of blood-pool images obtained with TcDx of different molecular weights (4 X 10(4) . Dx-40; 5 X 10(5) . Dx-500; 2 X 10(6) . Dx-2000) and with /sup 99m/Tc red blood cells (TcRBC) labeled in vitro, and determined the organ distribution of this new agent by whole-body scanning and blood sampling. TcDx provided high-quality cardiac blood-pool images up to 60 min after injection. The heart-to-lung ratios averaged 3.7 for TcDx-40, 3.9 for TcDx-500, and 5.4 for TcRBC at 60 min. Whereas TcDx-40 showed a relatively rapid initial urinary excretion and TcDx-2000 was degraded rapidly, TcDx-500 demonstrated the best kinetics for blood-pool imaging. Thus, TcDx is a new radiopharmaceutical with high labeling efficiency and stability. It overcomes a number of the limitations of currently used blood-labeling agents and may become useful for blood-pool imaging in man

Development of kits for 99mTc radiopharmaceuticals for infection imaging. Report of a co-ordinated research project 2000-2003

International Nuclear Information System (INIS)

2004-09-01

Infectious diseases remain a major health problem and cause of death worldwide, particularly in developing countries. Nuclear medicine imaging, because of its sensitivity, offers an attractive option for diagnosis of focal infections. This needs a reliable radiopharmaceutical that can selectively concentrate in sites of infection. Over the years 67 Ga and other radiopharmaceuticals that localize in inflammation associated with infection sites, also known as 'non-specific agents' have been used for infection imaging. However, experience has shown that an 'infection specific agent' that concentrates selectively at sites of infection and not inflammation would have several advantages. The first such agent developed more than two decades ago was 111 In-leucocytes which is still considered a 'gold standard'. Considerations of cost, availability, and superior properties for imaging make 99 mTc a better label than 111 In. 99 mTc white blood cell (WBC) was developed subsequently and used for infection imaging. However, both 111 In and 99 mTc WBCs have a number of drawbacks, in particular: each patient's blood sample has to be collected and individually radiolabelled; well-trained staff and suitable facilities for separating and labelling the patient's blood are needed; the risk of infection and cross-contamination associated with potential blood-borne microorganisms; and cost of materials. Because of these, considerable efforts have been continuously made towards developing convenient replacements for 99 mTc WBCs with limited success, 99 mTc antigranulocyte antibody being a good example. However, these radiopharmaceuticals still have many disadvantages, related to either their cost and availability or their performance. In view of the large potential for applications in patients, the development of new and improved 99 mTc labelled infection specific imaging agents was considered as a very worthwhile aim for scientific research in general and, in particular, for the

Studies on the preparation of sup(99m)Tc labelled medical tracer compounds: pt. 4

International Nuclear Information System (INIS)

Kim, J.R.; Park, K.B.; Shim, H.S.

1981-01-01

A crude extract from a Korean native plant, Banha (Pinellia ternata), has been known to agglutinate the erythrocytes of rabbit, mouse and especially erythrocytes of leukemic patients, Sarcoma-180 cell and Ehrlich ascite cell. The Banha lectin was labelled either with 125 with 125 I by means of chloramine-T method or with sup(99m)Tc by using aqueous sodium pertechnetate (- sup(99m)Tc) solution and stannous chloride as a reducing agent. Their labelling yield was 60% and 98%, respectively. These labelled compounds were administered to mice by intraperitoneal injections and their radioactivity distributions were measured after 3 hours. The uptake of 125 I labelled compound to tissue in mice appeared in the order of kidney, pancreas, spleen, liver, blood, and stomach, but in the case of sup(99m)Tc, it appeared in the order of kidney, pancreas, stomach, liver, spleen and blood

Production of kits for the labelling with 113sup(m)In and sup(99m)Tc, at the CNEA

International Nuclear Information System (INIS)

Palcos, M.C.; Kurcbart, Horacio; Nowotny, G.; Ramos, Elsa; Riesgo, J.G.; Mitta, A.E.A.

1978-05-01

The actual state of the production of radiopharmaceuticals in the form of reagents kits at the C.N.E.A. is described. This could allow the users to label compounds with sup(113m)In and sup(99m)Tc in an easy and reproducible way. At present, the following sets are provided routinarily a) To label with sup(99m)Tc: Albumin macroaggregates: calcium gluconate; antimonium sulfide colloid, sodium phytate; sodium calcium DTPA; seroalbumin; sodium pyrophosphate; sodium citrate. b) To label with sup(113m)In: albumin macroaggregates; PVP-bicarbonate; DTPA; human seroalbumin. Regarding products in a developping stage, we have: to labed with sup(99m)Tc: dimercapto-succinic acid, set for the labelling of human erythrocytes, set for sup(113m)In and sup(99m)Tc concentration and bleomicin; to label with sup(113m)In: EDTMP sup(99m)In. (author) [es

Phosphorylation of basic helix-loop-helix transcription factor Twist in development and disease.

Science.gov (United States)

Xue, Gongda; Hemmings, Brian A

2012-02-01

The transcription factor Twist plays vital roles during embryonic development through regulating/controlling cell migration. However, postnatally, in normal physiological settings, Twist is either not expressed or inactivated. Increasing evidence shows a strong correlation between Twist reactivation and both cancer progression and malignancy, where the transcriptional activities of Twist support cancer cells to disseminate from primary tumours and subsequently establish a secondary tumour growth in distant organs. However, it is largely unclear how this signalling programme is reactivated or what signalling pathways regulate its activity. The present review discusses recent advances in Twist regulation and activity, with a focus on phosphorylation-dependent Twist activity, potential upstream kinases and the contribution of these factors in transducing biological signals from upstream signalling complexes. The recent advances in these areas have shed new light on how phosphorylation-dependent regulation of the Twist proteins promotes or suppresses Twist activity, leading to differential regulation of Twist transcriptional targets and thereby influencing cell fate.

Technetium {sup 99m}Tc Pertechnetate Brain Scanning

Energy Technology Data Exchange (ETDEWEB)

Rhee, Sang Min; Park, Jin Yung; Lee, Ahn Ki; Chung, Choo Il; Hong, Chang Gi [Capital Army Hospital, ROKA, Seoul (Korea, Republic of); Rhee, Chong Heon; Koh, Chang Soon [Radiological Research Institute, Seoul (Korea, Republic of)

1968-03-15

Technetium {sup 99}mTc pertechnetate brain scanning were performed in 3 cases of head injury (2 chronic subdural hematomas and 1 acute epidural hematoma), 2 cases of brain abscess and 1 case of intracerebral hematoma associated with arteriovenous anomaly. In all the cases brain scintigrams showed 'hot areas.' Literatures on radioisotope scanning of intracranial lesions were briefly reviewed. With the improvement of radioisotope scanner and development of new radiopharmaceuticals brain scanning became a safe and useful screening test for diagnosis of intracranial lesions. Brain scanning can be easily performed even to a moribund patient without any discomfort and risk to the patient which are associated with cerebral angiography or pneumoencephalography. Brain scanning has been useful in diagnosis of brain tumor, brain abscess, subdural hematoma, and cerebral vascular diseases. In 80 to 90% of brain tumors positive scintigrams can be expected. Early studies were done with 203 Hg-Neohydrin or {sup 131}I-serum albumin. With these agents, however, patients receive rather much radiation to the whole body and kidneys. In 1965 Harper introduced {sup 99}mTc to reduce radiation dose to the patient and improve statistical variation in isotope scanning.

Further Generalisations of Twisted Gabidulin Codes

DEFF Research Database (Denmark)

Puchinger, Sven; Rosenkilde, Johan Sebastian Heesemann; Sheekey, John

2017-01-01

We present a new family of maximum rank distance (MRD) codes. The new class contains codes that are neither equivalent to a generalised Gabidulin nor to a twisted Gabidulin code, the only two known general constructions of linear MRD codes.......We present a new family of maximum rank distance (MRD) codes. The new class contains codes that are neither equivalent to a generalised Gabidulin nor to a twisted Gabidulin code, the only two known general constructions of linear MRD codes....

Geometry of the toroidal N-helix: optimal-packing and zero-twist

DEFF Research Database (Denmark)

Olsen, Kasper; Bohr, Jakob

2012-01-01

Two important geometrical properties of N-helix structures are influenced by bending. One is maximizing the volume fraction, which is called optimal-packing, and the other is having a vanishing strain-twist coupling, which is called zero-twist. Zero-twist helices rotate neither in one nor...... helix. General N-helices are discussed, as well as zero-twist helices for N > 1. The derived geometrical restrictions are gradually modified by changing the aspect ratio of the torus....

A method to estimate the necessary twist pitch in multi-filamentary superconductors

International Nuclear Information System (INIS)

Lindau, S; Magnusson, N; Taxt, H

2014-01-01

Twisting of multi-filamentary superconductors is an important step in the development of wires with AC losses at an acceptable level for AC applications. The necessary twist pitch depends on wire architecture, critical current density, matrix material, and external factors such as temperature, frequency and applied magnetic field. The development of an AC optimized MgB 2 superconductor would be facilitated by a fast method to set the requirements for the twist pitch. A problem often encountered when comparing wires with different twist pitches is the degradation in critical current occurring at small twist pitches due to mechanical deformation. In this work we propose to use a non-twisted conductor to estimate the influence of twisting on the AC losses. A long superconductor is cut into smaller lengths, each simulating one third of the twist pitch, and the AC losses due to applied magnetic fields are compared between samples of different lengths. With this method, the effect of reducing the size of the loop of the coupling currents is studied without changing the superconducting parameters. AC loss measurement results are presented for a round titanium matrix MgB 2 wire with simulated twist pitches between 9 mm and 87 mm.

New twist on artificial muscles.

Science.gov (United States)

Haines, Carter S; Li, Na; Spinks, Geoffrey M; Aliev, Ali E; Di, Jiangtao; Baughman, Ray H

2016-10-18

Lightweight artificial muscle fibers that can match the large tensile stroke of natural muscles have been elusive. In particular, low stroke, limited cycle life, and inefficient energy conversion have combined with high cost and hysteretic performance to restrict practical use. In recent years, a new class of artificial muscles, based on highly twisted fibers, has emerged that can deliver more than 2,000 J/kg of specific work during muscle contraction, compared with just 40 J/kg for natural muscle. Thermally actuated muscles made from ordinary polymer fibers can deliver long-life, hysteresis-free tensile strokes of more than 30% and torsional actuation capable of spinning a paddle at speeds of more than 100,000 rpm. In this perspective, we explore the mechanisms and potential applications of present twisted fiber muscles and the future opportunities and challenges for developing twisted muscles having improved cycle rates, efficiencies, and functionality. We also demonstrate artificial muscle sewing threads and textiles and coiled structures that exhibit nearly unlimited actuation strokes. In addition to robotics and prosthetics, future applications include smart textiles that change breathability in response to temperature and moisture and window shutters that automatically open and close to conserve energy.

Quantitative evaluation of bile diversion surgery utilizing /sup 99m/Tc HIDA scintigraphy

International Nuclear Information System (INIS)

Wickremesinghe, P.C.; Dayrit, P.Q.; Manfredi, O.L.; Fazio, R.A.; Fagel, V.L.

1983-01-01

This is a report of 21 patients presenting with epigastric pain, bilious vomiting, upper gastrointestinal bleeding, iron-deficiency anemia, and weight loss, who had undergone Billroth II gastrectomy from 3 to 35 yr earlier. Eighteen of 21 patients were found to have significant enterogastric reflux indices varying from 60% to 95% demonstrated by /sup 99m/Tc HIDA scintigraphy. Thirteen patients had diversion antireflux surgery in the form of a Roux-en-Y procedure, and 1 patient had a Henley loop jejunal interposition. Postoperative /sup 99m/Tc HIDA scintigraphic studies showed the enterogastric reflux indices to have decreased significantly to a range of 2%-26% (p less than 0.00001). There was marked improvement of symptoms, including correction of anemia and weight gain in those patients who had been anemic or who had sustained earlier weight loss. The enterogastric reflux indices of 10 asymptomatic control patients after Billroth II gastrectomy ranged from 4% to 45%. /sup 99m/Tc HIDA scintigraphy is useful in evaluating patients before and after bile diversion surgery, and demonstrates the quantitative decrease in enterogastric reflux after such surgery

PENGARUH REGENERASI KOLOM ALUMINA ASAM TERHADAP RECOVERY DAN KUALITAS 99mTc HASIL EKSTRAKSI PELARUT MEK DARI 99Mo HASIL AKTIVASI NEUTRON

Directory of Open Access Journals (Sweden)

Adang H G

2017-01-01

Full Text Available ABSTRAK PENGARUH REGENERASI KOLOM ALUMINA ASAM TERHADAP RECOVERY DAN KUALITAS 99mTc HASIL EKSTRAKSI PELARUT MEK DARI 99Mo HASIL AKTIVASI NEUTRON. Melalui kerjasama antara PTRR-BATAN, Chiyoda dan JAEA Jepang telah dilakukan pemurnian 99mTc dari 99Mo hasil aktivasi neutron dengan menggunakan metode kromatografi kolom alumina asam terhadap hasil ekstraksi MEK (Metil Etil Keton. Pemurnian 99mTc dengan metode kolom alumina asam hanya dapat digunakan satu kali dan pemurnian berikutnya harus diganti dengan kolom baru. Hal ini dinilai kurang praktis dan juga memerlukan biaya yang mahal. Dalam penelitian ini dicoba penggunaan kolom alumina asam untuk pemurnian 99mTc lebih dari satu kali dengan melakukan proses regenerasi dengan cara melewatkan larutan HNO3 0,1N setiap kali proses pemurnian selesai. Penelitian ini bertujuan untuk mendapatkan larutan 99mTc yang dapat digunakan untuk penandaan kit radiofarmaka. Parameter yang diamati dalam penelitian ini adalah recovery, profil elusi, pH, kemurnian radiokimia dan kemurnian radionuklida (lolosan 99Mo. Hasil penelitian yang dilakukan selama 5 hari telah diperoleh pH ~5, recovery > 60 %, kemurnian radiokimia > 95 % dan lolosan 99Mo tidak terdeteksi. Dari hasil perlakuan terhadap kolom alumina asam dengan larutan HNO3 0,1 N disimpulkan bahwa kolom alumina asam tidak perlu diganti setiap hari. Kata kunci: 99mTc, 99Mo, MEK, kolom alumina asam, kemurnian radiokimia. ABSTRACT Purification of 99mTc from 99Mo activation using acidic alumina column chromatography system from MEK (Methyl Ethyl Keton extraction has been carried out through cooperation between PTRR - BATAN, Chiyoda and JAEA Japan. This method has a limitation that acidic alumina column for purification of 99mTc can be used only once, for the next purification acidic alumina column should be replaced with new column, so it is less practical and also requires high cost. This study aims to obtain a 99mTc solution can be use for labelling of a

{sup 99m}Tc Nanocoll: A radiopharmaceutical for sentinel node localisation in breast cancer-In vitro and in vivo results

Energy Technology Data Exchange (ETDEWEB)

Gommans, G.M.M. [Department of Nuclear Medicine, West-Fries Hospital Hoorn (Netherlands); Department of Nuclear Medicine (0030), Medical Centre Alkmaar, Wilhelminalaan 12, 1815 JD Alkmar (Netherlands)], E-mail: g.m.m.gommans@mca.nl; Gommans, E. [Department of Chemical Engineering, Twente University of Technology (Netherlands); Zant, F.M. van der [Department of Nuclear Medicine (0030), Medical Centre Alkmaar, Wilhelminalaan 12, 1815 JD Alkmar (Netherlands); Teule, G.J.J. [Department of Nuclear Medicine, University Medical Centre Maastricht (Netherlands); Schors, T.G. van der [Department of Clinical Pharmacy, West-Fries Hospital Hoorn (Netherlands); Waard, J.W.D. de [Department of Surgery, West-Fries Hospital Hoorn (Netherlands)

2009-09-15

This study evaluated labelling efficiency and radiochemical purity of {sup 99m}Tc colloid albumin to identify an optimal labelling protocol for sentinel node detection. Results indicate that a 72 h eluate is not recommended for high specific labelling of {sup 99m}Tc colloid albumin. Ex vivo, significantly higher count rates were reached using a 2 h eluate in vacuum or nitrogen. Labelling 26 MBq/{mu}g {sup 99m}Tc colloid albumin with a 2 h eluate under nitrogen is recommended because of the ease of labelling.

Electrically Controllable Magnetism in Twisted Bilayer Graphene.

Science.gov (United States)

Gonzalez-Arraga, Luis A; Lado, J L; Guinea, Francisco; San-Jose, Pablo

2017-09-08

Twisted graphene bilayers develop highly localized states around AA-stacked regions for small twist angles. We show that interaction effects may induce either an antiferromagnetic or a ferromagnetic (FM) polarization of said regions, depending on the electrical bias between layers. Remarkably, FM-polarized AA regions under bias develop spiral magnetic ordering, with a relative 120° misalignment between neighboring regions due to a frustrated antiferromagnetic exchange. This remarkable spiral magnetism emerges naturally without the need of spin-orbit coupling, and competes with the more conventional lattice-antiferromagnetic instability, which interestingly develops at smaller bias under weaker interactions than in monolayer graphene, due to Fermi velocity suppression. This rich and electrically controllable magnetism could turn twisted bilayer graphene into an ideal system to study frustrated magnetism in two dimensions.

Synthesis and evaluation of hydroxamamide-based tetradentate ligands as a new class of thiol-free chelating molecules for 99mTc radiopharmaceuticals.

Science.gov (United States)

Xu, L C; Nakayama, M; Harada, K; Nakayama, H; Tomiguchi, S; Kojima, A; Takahashi, M; Arano, Y

1998-04-01

Both N,N'-ethylene bis(benzohydroxamamide) [(C2(BHam)2)] and N,N'-propylene bis(benzohydroxamamide) [(C3(BHam)2)] were designed as new thiol-free chelating molecules for 99mTc radiopharmaceuticals. Synthetic procedures using oxadiazoline intermediates were developed for C2(BHam)2 and C3(BHam)2. Both C2(BHam)2 and C3(BHam)2 formed 99mTc complexes with high yields over a wide pH range (pH 3-12) at room temperature. Complexation yields of over 95% were achieved at ligand concentrations as low as 2.5 x 10(-6) M. Reversed-phase HPLC analyses indicated that both C2(BHam)2 and C3(BHam)2 formed 99mTc complexes as single species with stabilities much higher than those of 99mTc-BHam. Selective complex formation of 99mTc with the two ligands was observed in the presence of human IgG. No decomposition with low protein binding were demonstrated when the two 99mTc complexes were incubated in murine plasma. Although further structural studies are required, these findings implied that the Ham-based tetradentate ligands would serve as new chelating molecules for 99mTc radiopharmaceuticals.

Design of an X -band electron linear accelerator dedicated to decentralized 99Mo/99mTc supply: From beam energy selection to yield estimation

Science.gov (United States)

Jang, Jaewoong; Yamamoto, Masashi; Uesaka, Mitsuru

2017-10-01

The most frequently used radionuclide in diagnostic nuclear medicine, 99mTc, is generally obtained by the decay of its parent radionuclide, 99Mo. Recently, concerns have been raised over shortages of 99Mo/99mTc, owing to aging of the research reactors which have been supplying practically all of the global demand for 99Mo in a centralized fashion. In an effort to prevent such 99Mo/99mTc supply disruption and, furthermore, to ameliorate the underlying instability of the centralized 99Mo/99mTc supply chain, we designed an X -band electron linear accelerator which can be distributed over multiple regions, whereby 99Mo/99mTc can be supplied with improved accessibility. The electron beam energy was designed to be 35 MeV, at which an average beam power of 9.1 kW was calculated by the following beam dynamics analysis. Subsequent radioactivity modeling suggests that 11 of the designed electron linear accelerators can realize self-sufficiency of 99Mo/99mTc in Japan.

Design of an X-band electron linear accelerator dedicated to decentralized ^{99}Mo/^{99m}Tc supply: From beam energy selection to yield estimation

Directory of Open Access Journals (Sweden)

Jaewoong Jang

2017-10-01

Full Text Available The most frequently used radionuclide in diagnostic nuclear medicine, ^{99m}Tc, is generally obtained by the decay of its parent radionuclide, ^{99}Mo. Recently, concerns have been raised over shortages of ^{99}Mo/^{99m}Tc, owing to aging of the research reactors which have been supplying practically all of the global demand for ^{99}Mo in a centralized fashion. In an effort to prevent such ^{99}Mo/^{99m}Tc supply disruption and, furthermore, to ameliorate the underlying instability of the centralized ^{99}Mo/^{99m}Tc supply chain, we designed an X-band electron linear accelerator which can be distributed over multiple regions, whereby ^{99}Mo/^{99m}Tc can be supplied with improved accessibility. The electron beam energy was designed to be 35 MeV, at which an average beam power of 9.1 kW was calculated by the following beam dynamics analysis. Subsequent radioactivity modeling suggests that 11 of the designed electron linear accelerators can realize self-sufficiency of ^{99}Mo/^{99m}Tc in Japan.

Bend-twist coupling potential of wind turbine blades

DEFF Research Database (Denmark)

Fedorov, Vladimir; Berggreen, Christian

2014-01-01

-twist coupling magnitude of up to 0.2 is feasible to achieve in the baseline blade structure made of glass-fiber reinforced plastics. Further, by substituting the glass-fibers with carbon-fibers the coupling effect can be increased to 0.4. Additionally, the effect of introduction of bend-twist coupling...

Effects of triiodothyronine upon the 131I and sup(99m)Tc uptake by the submandibular salivary glands in A2G mice

International Nuclear Information System (INIS)

Houssay, A.B.; Gamper, C.H.; Curbelo, H.M.

1977-01-01

The organ:plasma ratios and the isotope uptake in thyroid and submandibular glands were measured at different time intervals after a tracer dose of 131 I or sup(99m)Tc. Triiodothyronine depressed markedly the isotope uptake in both glands, but the inhibition of 131 I or sup(99m)Tc uptake by the thyroids was obtained with much lower doses. Thyrotrophin, while increasing markedly the 131 I or sup(99m)Tc uptake by the thyroids, did not produce any change in the 131 I or sup(99m)Tc uptake by the submandibular glands, when given either to normal or to triiodothyronine-inhibited mice. (author)

Supersymmetric gauged double field theory: systematic derivation by virtue of twist

International Nuclear Information System (INIS)

Cho, Wonyoung; Fernández-Melgarejo, J.J.; Jeon, Imtak; Park, Jeong-Hyuck

2015-01-01

In a completely systematic and geometric way, we derive maximal and half-maximal supersymmetric gauged double field theories in lower than ten dimensions. To this end, we apply a simple twisting ansatz to the D=10 ungauged maximal and half-maximal supersymmetric double field theories constructed previously within the so-called semi-covariant formalism. The twisting ansatz may not satisfy the section condition. Nonetheless, all the features of the semi-covariant formalism, including its complete covariantizability, are still valid after the twist under alternative consistency conditions. The twist allows gaugings as supersymmetry preserving deformations of the D=10 untwisted theories after Scherk-Schwarz-type dimensional reductions. The maximal supersymmetric twist requires an extra condition to ensure both the Ramond-Ramond gauge symmetry and the 32 supersymmetries unbroken.

Nonlinear physics of twisted magnetic field lines

International Nuclear Information System (INIS)

Yoshida, Zensho

1998-01-01

Twisted magnetic field lines appear commonly in many different plasma systems, such as magnetic ropes created through interactions between the magnetosphere and the solar wind, magnetic clouds in the solar wind, solar corona, galactic jets, accretion discs, as well as fusion plasma devices. In this paper, we study the topological characterization of twisted magnetic fields, nonlinear effect induced by the Lorentz back reaction, length-scale bounds, and statistical distributions. (author)

The labelling of antibody anti-PBP2a with {sup 99m}Tc; Estudo de marcacao do anticorpo monoclonal anti-PBP2a com {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Mororo, Janio da Silva

2012-07-01

Staphylococcus aureus is a major cause of life-threatening infections such as bacteraemia and endocarditis. Unfortunately, many strains of this bacterial species have become resistant to certain antibiotics, including methicillin and amoxicillin. These strains are known as methicillin-resistant S. aureus (MRSA). The penicillin binding protein 2a (PBP2a) is the enzyme responsible for conferring resistance p-lactams antibiotics for MRSA, being one promising molecule for therapy with mAb. However, besides the therapy, the methods of diagnosis are also inefficient because the diagnosis currently takes several days to produce a reliable result. Taking into account, the objective of this research was radiolabeling one anti-PBP2a mAb developed by Bio-Manguinhos/FioCruz-RJ, utilizing {sup 99m}Tc, for in situ diagnostic of the infectious caused by MRSA. First, anti-PBP2a mAb was reduced utilizing 2-mecaptoethanol (2-ME) for generate sulphydryl groups (-SH) and after to be labeled with {sup 99m}Tc. In this work, were utilized two techniques of direct method: Method 1, using tartrate and gentisic acid reagents, acting like transchelant and stabilizer agents, respectively; and Method 2, using one commercial kit of MDP. Besides the radiolabeling, the mAb reduced and mAb labeled with {sup 99m}Tc were submitted to immunoreactivity analysis, with SDS-PAGE non-reducing, Immunoblotting, ELISA and neutralization assay in vitro methods. The quantity produced of sulphydryl groups by mAb was satisfactory, approximately 5 per mAb, utilizing 6.500:1 of 2-ME:mAb molar ratio. The better labeling method was Method 2, with labeling yield of 73.5%, and showed a good stability after 2 hours (73.2%). The better formulation was: 0.5 mg of mAb anti- PBP2a, 10 {mu}U of MDP kit, after resuspended with 5 mL of saline, and 75.48 MBq (2.04 mCi) of {sup 99m}Tc, reacting by 15 minutes. The labeled mAb maintained the immunoreactivity, utilizing immunologic and in vitro experiments. (author)

Evaluation of patellar chondromalacia with MR: comparison between T2-weighted FSE SPIR and GE MTC.

Science.gov (United States)

Macarini, Luca; Perrone, Alessandra; Murrone, Mario; Marini, Stefania; Stefanelli, Michele

2004-09-01

To compare two different MR sequences to tissue signal suppression in the study of patellar cartilage abnormalities. We examined 26 patients with magnetic resonance (MR) imaging: sequences included spectral presaturation with inversion recovery (SPIR), with fat suppression and T2-weighted images, magnetization transfer contrast (MTC) sequences, T1-weighted and T2-weighted spin-echo sequences. All patients underwent conventional knee arthroscopy and in all patients a hyaline cartilage lesion was assessed in three articular zones: the patellar medial facet, the lateral facet and the patellar crista. Was assessed 78 articular facets. The lesions were classified using a standard arthroscopic grading system adapted to MR imaging: normal cartilage that corresponds to the grade 0 according to the Noyes grading system, low grade lesions that correspond to the grade I e IIa and high grade lesions that correspond to grades IIb and III. The arthroscopic results were compared with MR images. We assessed the MR diagnostic accuracy, sensitivity, specificity and MR positive predictive value and negative predictive value of the two sequences taking into consideration total lesions, and high-grade and low grade lesions separately. Twenty-four low grade lesions (16 grade I e 8 grade IIa) and 18 high grade lesions (10 grade IIb e 8 grade III) were diagnosed by arthroscopy. Regarding low grade and high-grade lesions together, the accuracy was 77% for MTC sequences and 90% for SPIR sequences. In identifying low-grade lesions, the sensitivity was 88% for SPIR sequence and 42% for MTC sequences. Specificity for the detection of all lesions was 89% for the SPIR sequences and 94% for the MTC sequences. The SPIR sequence visualised water content abnormalities in degenerating cartilage, which are representative of low-grade lesions. The sensitivity of the sequence enabled us to obtain improved contrast for detecting cartilage surface irregularities. The MTC sequences allowed us to grade high

Teaching Phagocytosis Using Flow Cytometry

Directory of Open Access Journals (Sweden)

John Boothby

2009-12-01

Full Text Available Investigative microbiology on protists in a basic teaching laboratory environment is limited by student skill level, ease of microbial culture and manipulation, instrumentation, and time. The flow cytometer is gaining use as a mainstream instrument in research and clinical laboratories, but has had minimal application in teaching laboratories. Although the cost of a flow cytometer is currently prohibitive for many microbiology teaching environments and the number of trained instructors and teaching materials is limited, in many ways the flow cytometer is an ideal instrument for teaching basic microbiology. We report here on a laboratory module to study phagocytosis in Tetrahymena sp. using flow cytometry in a basic microbiology teaching laboratory. Students and instructors found the flow cytometry data analysis program, Paint-A-GatePRO-TM, to be very intuitive and easy to learn within a short period of time. Assessment of student learning about Tetrahymena sp., phagocytosis, flow cytometry, and investigative microbiology using an inquiry-based format demonstrated an overall positive response from students.

Observations on discretization errors in twisted-mass lattice QCD

International Nuclear Information System (INIS)

Sharpe, Stephen R.

2005-01-01

I make a number of observations concerning discretization errors in twisted-mass lattice QCD that can be deduced by applying chiral perturbation theory including lattice artifacts. (1) The line along which the partially conserved axial current quark mass vanishes in the untwisted-mass-twisted-mass plane makes an angle to the twisted-mass axis which is a direct measure of O(a) terms in the chiral Lagrangian, and is found numerically to be large; (2) Numerical results for pionic quantities in the mass plane show the qualitative properties predicted by chiral perturbation theory, in particular, an asymmetry in slopes between positive and negative untwisted quark masses; (3) By extending the description of the 'Aoki regime' (where m q ∼a 2 Λ QCD 3 ) to next-to-leading order in chiral perturbation theory I show how the phase-transition lines and lines of maximal twist (using different definitions) extend into this region, and give predictions for the functional form of pionic quantities; (4) I argue that the recent claim that lattice artifacts at maximal twist have apparent infrared singularities in the chiral limit results from expanding about the incorrect vacuum state. Shifting to the correct vacuum (as can be done using chiral perturbation theory) the apparent singularities are summed into nonsingular, and furthermore predicted, forms. I further argue that there is no breakdown in the Symanzik expansion in powers of lattice spacing, and no barrier to simulating at maximal twist in the Aoki regime

Higher-twist correlations in polarized hadrons

International Nuclear Information System (INIS)

Tangerman, R.D.

1996-01-01

In this thesis we studied the response of polarized hadrons to several high-energy probes, working in the framework of the field theoretic model. Emphasis is laid upon higher-twist effects such as quark transverse momentum. The inclusive DIS process is very well suited to study QCD. From general principles we were able to derive four positivity constraints on the structure functions without invoking the helicity formalism. The on-shell quark model is used to illustrate these constraints. Subseqeuently, we concentrated on the higher-twist structure function g 2 (x,Q 2 ). (orig./HSI)

Transfer of 131I and sup(95m)Tc from pasture to goat milk

International Nuclear Information System (INIS)

Bondietti, E.A.; Garten, C.T. Jr.

1986-01-01

The purpose of this research was to compare the behaviour of 131 I (Tsub(1/2)=8.0d) and sup(95m)Tc (Tsub(1/2)=61d), which were sprayed on to pasture that was subsequently grazed by a herd of dairy goats. The transfer of 131 I to goats milk was about 5600 times more than that of sup(95m)Tc after 5 d of grazing contaminated pasture. Most of the difference appeared to be explained by a progressive immobilisation of technetium on vegetation, which occurred during the first few days of the experiment. (UK)

Immuno flow cytometry in marine phytoplankton research

NARCIS (Netherlands)

Peperzak, L; Vrieling, EG; Sandee, B; Rutten, T

The developments in the combination of flow cytometry and immunology as a tool to identify, count and examine marine phytoplankton cells are reviewed. The concepts of immunology and now cytometry are described. A distinction is made between quantitative and qualitative immunofluorescence.

Study of gels of molybdenum with cerium in the preparation of generators of 99Mo - 99mTc

Directory of Open Access Journals (Sweden)

Vanessa Moraes

2005-10-01

Full Text Available 99mTc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99Mo-99mTc generator. Four different types of generators are available: chromatographic that uses 99Mo from fission of uranium; MEK solvent extraction; Tc2O7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of 99mTc after irradiating the gels. Eight gels were prepared at the same temperature of 50 ºC with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of 99Mo-99mTc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.O 99mTc é o radiofármaco mais utilizado em Medicina Nuclear. Ele é obtido do gerador de 99Mo-99mTc e existem quatro tipos diferentes de geradores: cromatográfico que utiliza 99Mo de fissão; extração por solvente com MKT; sublimação do heptaóxido de tecnécio; cromatográfico tipo gel. Este trabalho apresenta a preparação de geradores tipo gel de molibdênio com cério, a caracterização desses géis com relação à quantidade de molibdênio e de cério, sua estrutura, tamanho das partículas e porcentagem de eluição do 99mTc após o gel ser irradiado. Foram preparados oito géis na temperatura de 50ºC com concentração de NaOH de 2 e 4 mol/L, relação de massa de 0,31 e 0,38 e pH final de 3,5 e 4,5. A análise dos resultados comprovou que esses géis não são adequados para preparação dos geradores de 99Mo-99mTc, já que as porcentagens de eluição são baixas, quando comparadas com o gel de molibdênio com zircônio.

Transcription factors zeb1, twist and snai1 in breast carcinoma

International Nuclear Information System (INIS)

Soini, Ylermi; Tuhkanen, Hanna; Sironen, Reijo; Virtanen, Ismo; Kataja, Vesa; Auvinen, Päivi; Mannermaa, Arto; Kosma, Veli-Matti

2011-01-01

Epitheliomesenchymal transition (EMT) is the process where cancer cells attain fibroblastic features and are thus able to invade neighboring tissues. Transcriptional factors zeb1, snai1 and twist regulate EMT. We used immunohistochemistry to investigate the expression of zeb1, twist and snai1 in tumor and stromal compartments by in a large set of breast carcinomas. The results were compared with estrogen and progesterone receptor status, HER2 amplification, grade, histology, TNM status and survival of the patients. Nuclear expression for twist was seen in the epithelial tumor cell compartment in 3.6% and for snai1 in 3.1% of the cases while zeb1 was not detected at all in these areas. In contrast, the tumor stromal compartment showed nuclear zeb1 and twist expression in 75% and 52.4% of the cases, respectively. Although rare, nuclear expression of twist in the epithelial tumor cell compartment was associated with a poor outcome of the patients (p = 0.054 log rank, p = 0.013, Breslow, p = 0.025 Tarone-Ware). Expression of snai1, or expression of zeb1 or twist in the stromal compartment did not have any prognostic significance. Furthermore, none of these factors associated with the size of the tumors, nor with the presence of axillary or distant metastases. Expression of zeb1 and twist in the stromal compartment was positively associated with a positive estrogen or progesterone receptor status of the tumors. Stromal zeb1 expression was significantly lower in ductal in situ carcinomas than in invasive carcinomas (p = 0.020). Medullary carcinomas (p = 0.017) and mucinous carcinomas (p = 0.009) had a lower stromal expression of zeb1 than ductal carcinomas. Stromal twist expression was also lower in mucinous (p = 0.017) than in ductal carcinomas. Expression of transcriptional factors zeb1 and twist mainly occur in the stromal compartment of breast carcinomas, possibly representing two populations of cells; EMT transformed neoplastic cells and stromal fibroblastic cells

Conformal invariance and pion wave functions of nonleading twist

International Nuclear Information System (INIS)

Braun, V.M.; Filyanov, I.E.

1989-01-01

The restrictions are studied for the general structure of pion wave functions of twist 3 and twist 4 imposed by the conformal symmetry and the equations of motion. A systematic expansion of wave functions in the conformal spin is built and the first order corrections to asymptotic formulae are calculated by the QCD sum rule method. In particular, we have found a multiplicatively renormalizable contribution into the two-particle wave function of twist 4 which cannot be expanded in a finite set of Gegenbauer polynomials. 19 refs.; 5 figs

Use of /sup 99m/Tc diethylenetriaminepentaacetic acid for assessment of renal function in dogs with suspected renal disease

International Nuclear Information System (INIS)

Krawiec, D.R.; Twardock, A.R.; Badertscher, R.R. II; Daniel, G.B.; Dugan, S.J.

1988-01-01

The effectiveness of technetium /sup 99m/-labeled diethylenetriaminepentaacetic acid (/sup 99m/Tc DTPA) to assess renal function in 13 dogs with suspected renal disease was evaluated. Glomerular filtration rates (actual GFR) were determined on the basis of endogenous creatinine clearance. Predicted GFR were determined by using /sup 99m/Tc DTPA within 72 hours after the determination of creatinine clearance. The percentage of an IV administered dose of /sup 99m/Tc DTPA in the kidneys (percentage dose) was determined. Two equations were used to calculate predicted GFR, which were derived from previously reported linear regression analysis of inulin (In) and creatinine (Cr) GFR vs percentage dose /sup 99m/Tc DTPA in dog kidneys. The correlations of actual GFR vs predicted GFR (In) and actual GFR vs predicted GFR (Cr) were both r = 0.92. The dogs' mean actual GFR was 1.73 +/- 1.35 ml/min/kg. Their mean predicted GFR (In) and predicted GFR (Cr) were 1.92 +/- 1.42 ml/min/kg and 1.85 +/- 1.27 ml/min/kg, respectively. Therefore, /sup 99m/Tc DTPA can be used with high accuracy as an agent to predict GFR in dogs with suspected renal disease. The procedure for determining GFR by use of nuclear medicine was rapid and noninvasive and appeared to induce little stress in the animals evaluated

Enhancement of turbulent flow heat transfer in a tube with modified twisted tapes

Energy Technology Data Exchange (ETDEWEB)

Lei, Y.G.; Zhao, C.H.; Song, C.F. [College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan (China)

2012-12-15

Numerical simulations were performed to study the fluid flow and heat transfer in a tube with staggered twisted tapes with central holes. In the range of Reynolds numbers between 6000 and 28 000, the modified twisted tapes increased the Nusselt number by 76.2 {proportional_to} 149.7 % and the friction factor by 380.2 {proportional_to} 443.8 % compared to the smooth tube. Compared to the typical twisted tapes, the modified twisted tapes produced an acceleration flow through the triangle regions leading to the enhancement of heat transfer, and the holes in the modified tapes reduced the severe pressure loss. It was found that the modified twisted tapes decreased the friction factor by 8.0 {proportional_to} 16.1 % and enhanced the heat transfer by 34.1 {proportional_to} 46.8 % in comparison with the typical tapes. These results indicated that the performance ratio values of the tube with modified twisted tapes were higher than 1.0 in the range of Reynolds numbers studied. The computed performance ratios of the tube with modified twisted tapes were much higher than those of the tube with typical twisted tapes. This means that the integrated performance of the tube with staggered twisted tapes with central holes is superior to that of the tube with typical twisted tapes. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Gauging the twisted Poincare symmetry as a noncommutative theory of gravitation

International Nuclear Information System (INIS)

Chaichian, M.; Tureanu, A.; Oksanen, M.; Zet, G.

2009-01-01

Einstein's theory of general relativity was formulated as a gauge theory of Lorentz symmetry by Utiyama in 1956, while the Einstein-Cartan gravitational theory was formulated by Kibble in 1961 as the gauge theory of Poincare transformations. In this framework, we propose a formulation of the gravitational theory on canonical noncommutative space-time by covariantly gauging the twisted Poincare symmetry, in order to fulfil the requirement of covariance under the general coordinate transformations, an essential ingredient of the theory of general relativity. It appears that the twisted Poincare symmetry cannot be gauged by generalizing the Abelian twist to a covariant non-Abelian twist, nor by introducing a more general covariant twist element. The advantages of such a formulation as well as the related problems are discussed and possible ways out are outlined.

Iterative methods for overlap and twisted mass fermions

International Nuclear Information System (INIS)

Chiarappa, T.; Jansen, K.; Shindler, A.; Wetzorke, I.; Scorzato, L.; Urbach, C.; Wenger, U.

2006-09-01

We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally) twisted mass fermions. The comparison of both formulations of lattice QCD is performed at four fixed values of the pion mass between 230 MeV and 720 MeV. For overlap fermions we address adaptive precision and low mode preconditioning while for twisted mass fermions we discuss even/odd preconditioning. Taking the best available algorithms in each case we find that calculations with the overlap operator are by a factor of 30-120 more expensive than with the twisted mass operator. (orig.)

Iterative methods for overlap and twisted mass fermions

Energy Technology Data Exchange (ETDEWEB)

Chiarappa, T. [Univ. di Milano Bicocca (Italy); Jansen, K.; Shindler, A.; Wetzorke, I. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Nagai, K.I. [Wuppertal Univ. (Gesamthochschule) (Germany). Fachbereich Physik; Papinutto, M. [INFN Sezione di Roma Tre, Rome (Italy); Scorzato, L. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT), Villazzano (Italy); Urbach, C. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences; Wenger, U. [ETH Zuerich (Switzerland). Inst. fuer Theoretische Physik

2006-09-15

We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally) twisted mass fermions. The comparison of both formulations of lattice QCD is performed at four fixed values of the pion mass between 230 MeV and 720 MeV. For overlap fermions we address adaptive precision and low mode preconditioning while for twisted mass fermions we discuss even/odd preconditioning. Taking the best available algorithms in each case we find that calculations with the overlap operator are by a factor of 30-120 more expensive than with the twisted mass operator. (orig.)

Template preparation of twisted nanoparticles of mesoporous silica

Institute of Scientific and Technical Information of China (English)

Kui Niu; Zhongbin Ni; Chengwu Fu; Tatsuo Kaneko; Mingqing Chen

2011-01-01

Optical isomers of N-lauroyl-L-(or-D-) alanine sodium salt {C12-L-(or-D-)AlaS} surfactants were used for the preparation of mesoporous silica nanoparticles with a twisted hexagonal rod-like morphology. Thermogravimetric analysis (TGA) was used to determine the temperature for template removal. Circular dichroism (CD) spectra of the surfactant solution with various compositions illustrated the formation and supramolecular assembly of protein-like molecular architecture leading to formation of twisted nanoparticles. Scanning electron microscopy (SEM),high-resolution transmission electron microscopy (HRTEM)and X-ray powder diffraction (XRD) patterns of these as-synthesized mesoporous silica confirmed that the twisted morphology of these nanoparticles was closely related to the supramolecular-assembled complex of amino acid surfactants.

Correlation Between Expression of Twist and Podoplanin in Ductal Breast Carcinoma.

Science.gov (United States)

Grzegrzolka, Jedrzej; Wojtyra, Patrycja; Biala, Martyna; Piotrowska, Aleksandra; Gomulkiewicz, Agnieszka; Rys, Janusz; Podhorska-Okolow, Marzenna; Dziegiel, Piotr

2017-10-01

As a result of activation of transcription factors engaged in epithelial-mesenchymal transition (EMT), such as Twist, inhibition of epithelial markers and an increased expression of mesenchymal markers are observed. One of the specific markers of cancer-associated fibroblasts is podoplanin (PDPN) - a mucin-type membrane glycoprotein. The aim of this work was to study the localisation and intensity of expression of Twist and PDPN on the mRNA and protein level in cases of invasive ductal breast carcinoma (IDC), and its association with patients' clinico-pathological data. The study included archival material in a form of 80 paraffin IDC blocks and 11 IDC fragments frozen in liquid nitrogen. Immunohistochemical expression of Twist and PDPN was evaluated using light microscope and semiquantitative scale for evaluation of nuclear expression or immunoreactive scale (IRS) for evaluation of cytoplasmic expression. Material was isolated from frozen IDC fragments using laser micro-dissection (from cancer and stromal cells, separately) and was used to perform real-time PCR. Twist expression was higher in stromal cells in comparison to cancer cells. Analysis of patients' survival rate showed, that higher expression of Twist in cancer cells was associated with shorter overall survival time and shorter event-free survival time. The expression of PDPN was also higher in stromal cells in comparison with cancer cells. In addition, positive correlation was observed between expression of Twist and PDPN in stromal cells of IDC (r=0.267; p<0.05). The relationship between the higher expression of Twist in both cancer and stromal cells and shorter patients' survival indicates Twist as a potential useful prognostic marker in IDC. Positive correlation of Twist and PDPN expression may indicate the role of PDPN in EMT in IDC. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Twisted entire cyclic cohomology, J-L-O cocycles and equivariant spectral triples

International Nuclear Information System (INIS)

Goswami, D.

2002-07-01

We study the 'quantized calculus' corresponding to the algebraic ideas related to 'twisted cyclic cohomology'. With very similar definitions and techniques, we define and study 'twisted entire cyclic cohomology' and the 'twisted Chern character' associated with an appropriate operator theoretic data called 'twisted spectral data', which consists of a spectral triple in the conventional sense of noncommutative geometry and an additional positive operator having some specified properties. Furthermore, it is shown that given a spectral triple (in the conventional sense) which is equivariant under the action of a compact matrix pseudogroup, it is possible to obtain a canonical twisted spectral data and hence the corresponding (twisted) Chern character, which will be invariant under the action of the pseudogroup, in contrast to the fact that the Chern character coming from the conventional noncommutative geometry need not be invariant under the above action. (author)

On the space of connections having non-trivial twisted harmonic spinors

International Nuclear Information System (INIS)

Bei, Francesco; Waterstraat, Nils

2015-01-01

We consider Dirac operators on odd-dimensional compact spin manifolds which are twisted by a product bundle. We show that the space of connections on the twisting bundle which yields an invertible operator has infinitely many connected components if the untwisted Dirac operator is invertible and the dimension of the twisting bundle is sufficiently large

On the space of connections having non-trivial twisted harmonic spinors

Energy Technology Data Exchange (ETDEWEB)

Bei, Francesco, E-mail: bei@math.hu-berlin.de [Institut für Mathematik, Humboldt Universität zu Berlin, Unter den Linden 6, 10099 Berlin (Germany); Waterstraat, Nils, E-mail: n.waterstraat@kent.ac.uk [School of Mathematics, Statistics & Actuarial Science, University of Kent, Canterbury, Kent CT2 7NF (United Kingdom)

2015-09-15

We consider Dirac operators on odd-dimensional compact spin manifolds which are twisted by a product bundle. We show that the space of connections on the twisting bundle which yields an invertible operator has infinitely many connected components if the untwisted Dirac operator is invertible and the dimension of the twisting bundle is sufficiently large.

Aeroelastic Analysis of Helicopter Rotor Blades Incorporating Anisotropic Piezoelectric Twist Actuation

Science.gov (United States)

Wilkie, W. Keats; Belvin, W. Keith; Park, K. C.

1996-01-01

A simple aeroelastic analysis of a helicopter rotor blade incorporating embedded piezoelectric fiber composite, interdigitated electrode blade twist actuators is described. The analysis consists of a linear torsion and flapwise bending model coupled with a nonlinear ONERA based unsteady aerodynamics model. A modified Galerkin procedure is performed upon the rotor blade partial differential equations of motion to develop a system of ordinary differential equations suitable for dynamics simulation using numerical integration. The twist actuation responses for three conceptual fullscale blade designs with realistic constraints on blade mass are numerically evaluated using the analysis. Numerical results indicate that useful amplitudes of nonresonant elastic twist, on the order of one to two degrees, are achievable under one-g hovering flight conditions for interdigitated electrode poling configurations. Twist actuation for the interdigitated electrode blades is also compared with the twist actuation of a conventionally poled piezoelectric fiber composite blade. Elastic twist produced using the interdigitated electrode actuators was found to be four to five times larger than that obtained with the conventionally poled actuators.

Quadratic Twists of Rigid Calabi–Yau Threefolds Over

DEFF Research Database (Denmark)

Gouvêa, Fernando Q.; Kiming, Ian; Yui, Noriko

2013-01-01

of weight 4 on some Γ 0(N). We show that quadratic twisting of a threefold corresponds to twisting the attached newform by quadratic characters and illustrate with a number of obvious and not so obvious examples. The question is motivated by the deeper question of which newforms of weight 4 on some Γ 0(N...

The geometric Langlands twist in five and six dimensions

International Nuclear Information System (INIS)

Bak, Dongsu; Gustavsson, Andreas

2015-01-01

Abelian 6d (2,0) theory has SO(5) R symmetry. We twist this theory by identifying the R symmetry group with the SO(5) subgroup of the SO(1,5) Lorentz group. This twisted theory can be put on any five-manifold M, times R, while preserving one scalar supercharge. We subsequently assume the existence of one unit normalized Killing vector field on M, and we find a corresponding SO(4) twist that preserves two supercharges and is a generalization of the geometric Langlands twist of 4d SYM. We generalize the story to non-Abelian gauge group for the corresponding 5d SYM theories on M. We derive a vanishing theorem for BPS contact instantons by identifying the 6d potential energy and its BPS bound, in the 5d theory. To this end we need to perform a Wick rotation that complexifies the gauge field.

Higher-Twist Dynamics in Large Transverse Momentum Hadron Production

International Nuclear Information System (INIS)

Francois, Alero

2009-01-01

A scaling law analysis of the world data on inclusive large-p # perpendicular# hadron production in hadronic collisions is carried out. A significant deviation from leading-twist perturbative QCD predictions at next-to-leading order is reported. The observed discrepancy is largest at high values of x # perpendicular# = 2p # perpendicular#/√s. In contrast, the production of prompt photons and jets exhibits the scaling behavior which is close to the conformal limit, in agreement with the leading-twist expectation. These results bring evidence for a non-negligible contribution of higher-twist processes in large-p # perpendicular# hadron production in hadronic collisions, where the hadron is produced directly in the hard subprocess rather than by gluon or quark jet fragmentation. Predictions for scaling exponents at RHIC and LHC are given, and it is suggested to trigger the isolated large-p # perpendicular# hadron production to enhance higher-twist processes.

99mTc ovalbumin labelled eggs for gastric emptying scintigraphy: in-vitro comparison of solid food markers.

Science.gov (United States)

Blanc, Frédérique; Salaun, Pierre Y; Couturier, Olivier; Querellou, Solène; Le Duc-Pennec, Alexandra; Mougin-Degraef, Marie; Bizais, Yves; Legendre, Jean M

2005-11-01

The reliability of solid phase gastric emptying measurements by scintigraphy requires a marker that remains within the solid component of the test meal, and which is not degraded by the gastric juice throughout the scintigraphic procedure. In Europe, foods are most often labelled with 99mTc rhenium sulfide macrocolloid (RSMC) but this solid phase marker was withdrawn from the market in January 2004. To test other potential solid phase markers and to compare them to the reference marker RSMC. These markers were rhenium sulfide nanocolloid (RSNC), tin fluoride colloid (TFC), phytates and two albumins (Alb and AlbC). All were radiolabelled with 99mTc. After quality control, each 99mTc marker was incorporated into the albumin of one egg. Then, egg white and yolk were mixed together, and a well-cooked omelette was prepared. Aliquots of the omelette were incubated with an acidic solution of pepsin at 37 degrees C which mimicked gastric juice. Unbound radioactivity in the supernatant fraction was measured at various times up to 3 h. The radiochemical purity was > 95% for all radiopharmaceuticals. During the in-vitro incubation, the percentage of 99mTc labelled colloids released from the omelette increased continuously: after 3 h, 5% for TFC and RSMC, 8% for phytates, and > 9% for the two albumins and RSNC. Considering quality controls and release of 99mTc during in-vitro incubation of the omelette, TFC showed the same behaviour as the reference marker RSMC. Thus, TFC seems to be the best candidate to replace RSMC for the radiolabelling of the solid phase of the gastric emptying test meal.

Periodic solutions of asymptotically linear Hamiltonian systems without twist conditions

Energy Technology Data Exchange (ETDEWEB)

Cheng Rong [Coll. of Mathematics and Physics, Nanjing Univ. of Information Science and Tech., Nanjing (China); Dept. of Mathematics, Southeast Univ., Nanjing (China); Zhang Dongfeng [Dept. of Mathematics, Southeast Univ., Nanjing (China)

2010-05-15

In dynamical system theory, especially in many fields of applications from mechanics, Hamiltonian systems play an important role, since many related equations in mechanics can be written in an Hamiltonian form. In this paper, we study the existence of periodic solutions for a class of Hamiltonian systems. By applying the Galerkin approximation method together with a result of critical point theory, we establish the existence of periodic solutions of asymptotically linear Hamiltonian systems without twist conditions. Twist conditions play crucial roles in the study of periodic solutions for asymptotically linear Hamiltonian systems. The lack of twist conditions brings some difficulty to the study. To the authors' knowledge, very little is known about the case, where twist conditions do not hold. (orig.)

Preperation and performance of {sup 99}Mo/{sup 99m}Tc chromatographic column generator based on zirconium molybdosilicate

Energy Technology Data Exchange (ETDEWEB)

Mostafa, M.; Saber, H.M.; El-Sadek, A.A. [Atomic Energy Authority, Cairo (Egypt). Hot Labs. Center; Nassar, M.Y. [Benha Univ. (Egypt). Chemistry Dept.

2016-08-01

Zirconium molybdosilicate (ZrMoSi) gel prepared using {sup 99}Mo radiotracer via peroxo route was used as a base material for {sup 99}Mo/{sup 99m}Tc column generator. The {sup 99m}Tc elution yield and {sup 99}Mo breakthrough in the eluate were studied as a function of the pH-value of gel precipitation, gel drying temperature and Zr: Mo: Si molar ratio. Precipitation pH-value of 2, drying temperature of 100 C and Zr: Mo: Si molar ratio of 0.5: 0.5: 1 were found to be the optimum conditions achieving {sup 99m}Tc elution yield of 82% and {sup 99}Mo breakthrough of 1.0 x 10{sup -3}%. The gel prepared with the optimum conditions was characterized by BET surface area and pore size analyzer, IR spectroscopy, thermal analysis (TGA and DTA), XRD, XRF and FESEM. Technetium-99m eluted from the optimum ZrMoSi {sup 99}Mo/{sup 99m}Tc generator was found to have a high radiochemical purity (98% as {sup 99m}TcO{sub 4}{sup -}) and chemical purity meeting criteria of clinical grade.

Higher-Twist Distribution Amplitudes of the K Meson in QCD

CERN Document Server

Ball, P; Lenz, A; Ball, Patricia

2006-01-01

We present a systematic study of twist-3 and twist-4 light-cone distribution amplitudes of the K meson in QCD. The structure of SU(3)-breaking corrections is studied in detail. Non-perturbative input parameters are estimated from QCD sum rules and renormalons. As a by-product, we give a complete reanalysis of the twist-3 and -4 parameters of the pi-meson distribution amplitudes; some of the results differ from those usually quoted in the literature.

Continuous Static Gait with Twisting Trunk of a Metamorphic Quadruped Robot

Directory of Open Access Journals (Sweden)

C. Zhang

2018-01-01

Full Text Available The natural quadrupeds, such as geckos and lizards, often twist their trunks when moving. Conventional quadruped robots cannot perform the same motion due to equipping with a trunk which is a rigid body or at most consists of two blocks connected by passive joints. This paper proposes a metamorphic quadruped robot with a reconfigurable trunk which can implement active trunk motions, called MetaRobot I. The robot can imitate the natural quadrupeds to execute motion of trunk twisting. Benefiting from the twisting trunk, the stride length of this quadruped is increased comparing to that of conventional quadruped robots.In this paper a continuous static gait benefited from the twisting trunk performing the increased stride length is introduced. After that, the increased stride length relative to the trunk twisting will be analysed mathematically. Other points impacting the implementation of the increased stride length in the gait are investigated such as the upper limit of the stride length and the kinematic margin. The increased stride length in the gait will lead the increase of locomotion speed comparing with conventional quadruped robots, giving the extent that natural quadrupeds twisting their trunks when moving. The simulation and an experiment on the prototype are then carried out to illustrate the benefits on the stride length and locomotion speed brought by the twisting trunk to the quadruped robot.

Cerclage handling for improved fracture treatment. A biomechanical study on the twisting procedure.

Science.gov (United States)

Wähnert, D; Lenz, M; Schlegel, U; Perren, S; Windolf, M

2011-01-01

Twisting is clinically the most frequently applied method for tightening and maintaining cerclage fixation. The twisting procedure is controversially discussed. Several factors during twisting affect the mechanical behaviour of the cerclage. This in vitro study investigated the influence of different parameters of the twisting procedure on the fixation strength of the cerclage in an experimental setup with centripetal force application. Cortical half shells of the femoral shaft were mounted on a testing fixture. 1.0 mm, 1.25 mm and 1.5 mm stainless ste- el wire cerclages as well as a 1.0mm cable cerclage were applied to the bone. Pretension of the cerclage during the installation was measured during the locking procedure. Subsequently, cyclic testing was performed up to failure. Higher pretension could be achieved with increasing wire diameter. However, with larger wire diameter the drop of pre- tension due to the bending and cutting the twist also increased. The cable cerclage showed the highest pretension after locking. Cerclages twisted under traction revealed significantly higher initial cerclage tension. Plastically deformed twists offered higher cerclage pretension compared to twists which were deformed in the elastic region of the material. Cutting the wire within the twist caused the highest loss of cerclage tension (44% initial tension) whereas only 11 % was lost when cutting the wire ends separately. The bending direction of the twist significantly influenced the cerclage pretension. 45% pretension was lost in forward bending of the twist, 53% in perpendicular bending and 90% in backward bending. Several parameters affect the quality of a cerclage fixation. Adequate installation of cerclage wires could markedly improve the clinical outcome of cerclage.

AKT-ions with a TWIST between EMT and MET.

Science.gov (United States)

Tang, Huifang; Massi, Daniela; Hemmings, Brian A; Mandalà, Mario; Hu, Zhengqiang; Wicki, Andreas; Xue, Gongda

2016-09-20

The transcription factor Twist is an important regulator of cranial suture during embryogenesis. Closure of the neural tube is achieved via Twist-triggered cellular transition from an epithelial to mesenchymal phenotype, a process known as epithelial-mesenchymal transition (EMT), characterized by a remarkable increase in cell motility. In the absence of Twist activity, EMT and associated phenotypic changes in cell morphology and motility can also be induced, albeit moderately, by other transcription factor families, including Snail and Zeb. Aberrant EMT triggered by Twist in human mammary tumour cells was first reported to drive metastasis to the lung in a metastatic breast cancer model. Subsequent analysis of many types of carcinoma demonstrated overexpression of these unique EMT transcription factors, which statistically correlated with worse outcome, indicating their potential as biomarkers in the clinic. However, the mechanisms underlying their activation remain unclear. Interestingly, increasing evidence indicates they are selectively activated by distinct intracellular kinases, thereby acting as downstream effectors facilitating transduction of cytoplasmic signals into nucleus and reprogramming EMT and mesenchymal-epithelial transition (MET) transcription to control cell plasticity. Understanding these relationships and emerging data indicating differential phosphorylation of Twist leads to complex and even paradoxical functionalities, will be vital to unlocking their potential in clinical settings.

Conductive sub-layer of twisted-tape-induced swirl-flow heat transfer in vertical circular tubes with various twisted-tape inserts

Science.gov (United States)

Hata, K.; Fukuda, K.; Masuzaki, S.

2018-04-01

Twisted-tape-induced swirl-flow heat transfer due to exponentially increasing heat inputs with various exponential periods ( Q = Q 0 exp(t/τ), τ = 6.04 to 23.07 s) and twisted-tape-induced pressure drop was systematically measured for various mass velocities ( G = 4115 to 13,656 kg/m2 s), inlet liquid temperatures ( T in = 285.88 to 299.09 K), and inlet pressures ( P in = 847.45 to 943.29 kPa) using an experimental water loop flow. Measurements were made over a 59.2-mm effective length and three sections (upper, middle, and lower positions), within which four potential taps were spot-welded onto the outer surface of a 6-mm-inner-diameter, 69.6-mm-heated length, 0.4-mm-thickness platinum circular test tube. Type SUS304 twisted tapes with a width w = 5.6 mm, a thickness δ T = 0.6 mm, a total length l = 372 mm, and twist ratios y = 2.39 and 4.45 were employed in this study. The RANS equations (Reynolds Averaged Navier-Stokes Simulation) with a k-ɛ turbulence model for a circular tube 6 mm in diameter and 636 mm in length were numerically solved for heating of water with a heated section 6 mm in diameter and 70 mm in length using the CFD code, under the same conditions as the experimental ones and considering the temperature dependence of the thermo-physical properties concerned. The theoretical values of surface heat flux q on the circular tubes with twisted tapes with twist ratios y of 2.39 and 4.45 were found to be almost in agreement with the corresponding experimental values of heat flux q, with deviations of less than 30% for the range of temperature difference between the average heater inner surface temperature and the liquid bulk mean temperature ΔT L [ = T s,av - T L , T L = ( T in + T out )/2] considered in this study. The theoretical values of the local surface temperature T s , local average liquid temperature T f,av , and local liquid pressure drop ΔP x were found to be within almost 15% of the corresponding experimental ones. The thickness of the

Benchmark experiment for the cross section of the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions

Science.gov (United States)

Takács, S.; Ditrói, F.; Aikawa, M.; Haba, H.; Otuka, N.

2016-05-01

As nuclear medicine community has shown an increasing interest in accelerator produced 99mTc radionuclide, the possible alternative direct production routes for producing 99mTc were investigated intensively. One of these accelerator production routes is based on the 100Mo(p,2n)99mTc reaction. The cross section of this nuclear reaction was studied by several laboratories earlier but the available data-sets are not in good agreement. For large scale accelerator production of 99mTc based on the 100Mo(p,2n)99mTc reaction, a well-defined excitation function is required to optimise the production process effectively. One of our recent publications pointed out that most of the available experimental excitation functions for the 100Mo(p,2n)99mTc reaction have the same general shape while their amplitudes are different. To confirm the proper amplitude of the excitation function, results of three independent experiments were presented (Takács et al., 2015). In this work we present results of a thick target count rate measurement of the Eγ = 140.5 keV gamma-line from molybdenum irradiated by Ep = 17.9 MeV proton beam, as an integral benchmark experiment, to prove the cross section data reported for the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions in Takács et al. (2015).

'Twisted' strings and higher level Kac-Moody representations

International Nuclear Information System (INIS)

Horvath, Z.; Palla, L.

1989-01-01

Using an orbifold-like construction the twisted sector of a closed string moving on GxG (with G simply laced) is determined. A level-two G current operating there is constructed explicitly. The decomposition of the twisted sector into products between appropriate conformal and level-two G representations is given if 2 rank G-2 dim G/(2+g)<1. (orig.)

Sox5 induces epithelial to mesenchymal transition by transactivation of Twist1

International Nuclear Information System (INIS)

Pei, Xin-Hong; Lv, Xin-Quan; Li, Hui-Xiang

2014-01-01

Highlights: • Depletion of Sox5 inhibits breast cancer proliferation, migration, and invasion. • Sox5 transactivates Twist1 expression. • Sox5 induces epithelial to mesenchymal transition through transactivation of Twist1 expression. - Abstract: The epithelial to mesenchymal transition (EMT), a highly conserved cellular program, plays an important role in normal embryogenesis and cancer metastasis. Twist1, a master regulator of embryonic morphogenesis, is overexpressed in breast cancer and contributes to metastasis by promoting EMT. In exploring the mechanism underlying the increased Twist1 in breast cancer cells, we found that the transcription factor SRY (sex-determining region Y)-box 5(Sox5) is up-regulation in breast cancer cells and depletion of Sox5 inhibits breast cancer cell proliferation, migration, and invasion. Furthermore, depletion of Sox5 in breast cancer cells caused a dramatic decrease in Twist1 and chromosome immunoprecipitation assay showed that Sox5 can bind directly to the Twist1 promoter, suggesting that Sox5 transactivates Twist1 expression. We further demonstrated that knockdown of Sox5 up-regulated epithelial phenotype cell biomarker (E-cadherin) and down-regulated mesenchymal phenotype cell biomarkers (N-cadherin, Vimentin, and Fibronectin 1), resulting in suppression of EMT. Our study suggests that Sox5 transactivates Twist1 expression and plays an important role in the regulation of breast cancer progression

ggCyto: Next Generation Open-Source Visualization Software for Cytometry.

Science.gov (United States)

Van, Phu; Jiang, Wenxin; Gottardo, Raphael; Finak, Greg

2018-06-01

Open source software for computational cytometry has gained in popularity over the past few years. Efforts such as FlowCAP, the Lyoplate and Euroflow projects have highlighted the importance of efforts to standardize both experimental and computational aspects of cytometry data analysis. The R/BioConductor platform hosts the largest collection of open source cytometry software covering all aspects of data analysis and providing infrastructure to represent and analyze cytometry data with all relevant experimental, gating, and cell population annotations enabling fully reproducible data analysis. Data visualization frameworks to support this infrastructure have lagged behind. ggCyto is a new open-source BioConductor software package for cytometry data visualization built on ggplot2 that enables ggplot-like functionality with the core BioConductor flow cytometry data structures. Amongst its features are the ability to transform data and axes on-the-fly using cytometry-specific transformations, plot faceting by experimental meta-data variables, and partial matching of channel, marker and cell populations names to the contents of the BioConductor cytometry data structures. We demonstrate the salient features of the package using publicly available cytometry data with complete reproducible examples in a supplementary material vignette. https://bioconductor.org/packages/devel/bioc/html/ggcyto.html. gfinak@fredhutch.org. Supplementary data are available at Bioinformatics online and at http://rglab.org/ggcyto/.

Twisted spin Sutherland models from quantum Hamiltonian reduction

International Nuclear Information System (INIS)

Feher, L; Pusztai, B G

2008-01-01

Recent general results on Hamiltonian reductions under polar group actions are applied to study some reductions of the free particle governed by the Laplace-Beltrami operator of a compact, connected, simple Lie group. The reduced systems associated with arbitrary finite-dimensional irreducible representations of the group by using the symmetry induced by twisted conjugations are described in detail. These systems generically yield integrable Sutherland-type many-body models with spin, which are called twisted spin Sutherland models if the underlying twisted conjugations are built on non-trivial Dynkin diagram automorphisms. The spectra of these models can be calculated, in principle, by solving certain Clebsch-Gordan problems, and the result is presented for the models associated with the symmetric tensorial powers of the defining representation of SU(N)

A neutral lipophilic complex of sup(99m)Tc with a multidentate amine oxime

International Nuclear Information System (INIS)

Troutner, D.E.; Volkert, W.A.; Hoffman, T.J.; Holmes, R.A.

1984-01-01

Propylene amine oxime, 3,3'-(1,3-propanediyldiimino)bis(3-methyl-2-butanone)dioxime, (PnAO) forms a neutral lipophilic complex with sup(99m)Tc in >95% yield at room temperature at pH 5-10. The complex can be prepared with generator produced sup(99m)Tc using 10 -5 M SnC 4 H 4 O 6 as the reducing agent at ligand concentrations as low as 3 x 10 -5 M. It is stable in saline solutions for as long as 24 h. [Sup(99m)Tc]PnAO may be useful as an imaging agent which passively diffuses across the blood brain barrier. (author)

Extension-twist coupling of composite circular tubes with application to tilt rotor blade design

Science.gov (United States)

Nixon, Mark W.

1987-01-01

This investigation was conducted to determine if twist deformation required for the design of full-scale extension-twist-coupled tilt-rotor blades can be achieved within material design limit loads, and to demonstrate the accuracy of a coupled-beam analysis in predicting twist deformations. Two extension-twist-coupled tilt-rotor blade designs were developed based on theoretically optimum aerodynamic twist distributions. The designs indicated a twist rate requirement of between .216 and .333 deg/in. Agreement between axial tests and analytical predictions was within 10 percent at design limit loads. Agreement between the torsion tests and predictions was within 11 percent.

PARTIAL ERUPTION OF A FILAMENT WITH TWISTING NON-UNIFORM FIELDS

International Nuclear Information System (INIS)

Bi, Yi; Jiang, Yunchun; Yang, Jiayan; Xiang, Yongyuan; Cai, Yunfang; Liu, Weiwei

2015-01-01

The eruption of a filament in a kinklike fashion is often regarded as a signature of kink instability. However, the kink instability threshold for the filament’s magnetic structure is not widely understood. Using Hα observations from the New Vacuum Solar Telescope, we present a partial eruptive filament. During the eruption, the filament thread appeared to split from its middle and to break out in a kinklike fashion. In this period, the remaining filament material stayed below and erupted without the kinking motion later on. The coronal magnetic field lines associated with the filament are obtained from nonlinear force-free field extrapolations using the twelve-minute-cadence vector magnetograms of the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamic Observatory. We studied the extrapolated field lines passing through the magnetic dips which are in good agreement with the observed filament. The field lines are non-uniformly twisted and appear to be composed of two twisted flux ropes winding around each other. One of them has a higher twist than the other, and the flux rope with the higher twist has its dips aligned with the kinking eruptive thread at the beginning of its eruption. Before the eruption, moreover, the flux rope with the higher twist was found to expand with an approximately constant field twist. In addition, the helicity flux maps deduced from the HMI magnetograms show that some helicity is injected into the overlying magnetic arcade, but no significant helicity is injected into the flux ropes. Accordingly, we suggest that the highly twisted flux rope became kink unstable when the instability threshold declined with the expansion of the flux rope

Applications of flow cytometry in food microbiology

International Nuclear Information System (INIS)

Serrano Valerin, Pamela

2014-01-01

A compilation of data about cytometry and its applications is performed to analyze the impact on food microbiology. The technique of flow cytometry is described and the use in various fields of microbiology is analyzed. Flow cytometry future could be implemented in many clinical laboratories and food, considering the cost / benefit test to be done, because at the moment it has a high cost. The existence of new fluorochromes and monoclonal antibodies enable that many intracellular and extracellular cell parameters are detected in the future. The technique can be developed in the country in few years considering that the technique has improved the sensitivity and specificity of many tests [es

The geometrical origin of the strain-twist coupling in double helices

Directory of Open Access Journals (Sweden)

Kasper Olsen

2011-03-01

Full Text Available A simple geometrical explanation for the counterintuitive phenomenon when twist leads to extension in double helices is presented. The coupling between strain and twist is investigated using a tubular description. It is shown that the relation between strain and rotation is universal and depends only on the pitch angle. For pitch angles below 39.4° strain leads to further winding, while for larger pitch angles strain leads to unwinding. The zero-twist structure, with a pitch angle of 39.4°, is at the unique point between winding and unwinding and independent of the mechanical properties of the double helix. The existence of zero-twist structures, i.e. structures that display neither winding, nor unwinding under strain is discussed. Close-packed double helices are shown to extend rather than shorten when twisted. Numerical estimates of this elongation upon winding are given for DNA, chromatin, and RNA.

Dynamical twisted mass fermions with light quarks. Simulation and analysis details

Energy Technology Data Exchange (ETDEWEB)

Boucaud, P. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique; Dimopoulos, P. [Rome-2 Univ. (Italy). Dipt. di Fisica; Farchioni, F. [Muenster Univ. (DE). Inst. fuer Theoretische Physik] (and others)

2008-03-15

In a recent paper (2007) we presented precise lattice QCD results of our European Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem of tuning to maximal twist, the techniques we have used to compute correlators and error estimates. In addition, we provide more information on the algorithm used, the autocorrelation times and scale determination, the evaluation of disconnected contributions and the description of our data by means of chiral perturbation theory formulae. (orig.)

Dynamical twisted mass fermions with light quarks. Simulation and analysis details

International Nuclear Information System (INIS)

Boucaud, P.; Dimopoulos, P.; Farchioni, F.

2008-03-01

In a recent paper (2007) we presented precise lattice QCD results of our European Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem of tuning to maximal twist, the techniques we have used to compute correlators and error estimates. In addition, we provide more information on the algorithm used, the autocorrelation times and scale determination, the evaluation of disconnected contributions and the description of our data by means of chiral perturbation theory formulae. (orig.)

Composite material bend-twist coupling for wind turbine blade applications

Science.gov (United States)

Walsh, Justin M.

Current efforts in wind turbine blade design seek to employ bend-twist coupling of composite materials for passive power control by twisting blades to feather. Past efforts in this area of study have proved to be problematic, especially in formulation of the bend-twist coupling coefficient alpha. Kevlar/epoxy, carbon/epoxy and glass/epoxy specimens were manufactured to study bend-twist coupling, from which numerical and analytical models could be verified. Finite element analysis was implemented to evaluate fiber orientation and material property effects on coupling magnitude. An analytical/empirical model was then derived to describe numerical results and serve as a replacement for the commonly used coupling coefficient alpha. Through the results from numerical and analytical models, a foundation for aeroelastic design of wind turbines blades utilizing biased composite materials is provided.

Flux Density through Guides with Microstructured Twisted Clad DB Medium

Directory of Open Access Journals (Sweden)

M. A. Baqir

2014-01-01

Full Text Available The paper deals with the study of flux density through a newly proposed twisted clad guide containing DB medium. The inner core and the outer clad sections are usual dielectrics, and the introduced twisted windings at the core-clad interface are treated under DB boundary conditions. The pitch angle of twist is supposed to greatly contribute towards the control over the dispersion characteristics of the guide. The eigenvalue equation for the guiding structure is deduced, and the analytical investigations are made to explore the propagation patterns of flux densities corresponding to the sustained low-order hybrid modes under the situation of varying pitch angles. The emphasis has been put on the effects due to the DB twisted pitch on the propagation of energy flux density through the guide.

Effect of Twisting and Stretching on Magneto Resistance and Spin Filtration in CNTs

Directory of Open Access Journals (Sweden)

Anil Kumar Singh

2017-08-01

Full Text Available Spin-dependent quantum transport properties in twisted carbon nanotube and stretched carbon nanotube are calculated using density functional theory (DFT and non-equilibrium green’s function (NEGF formulation. Twisting and stretching have no effect on spin transport in CNTs at low bias voltages. However, at high bias voltages the effects are significant. Stretching restricts any spin-up current in antiparallel configuration (APC, which results in higher magneto resistance (MR. Twisting allows spin-up current almost equivalent to the pristine CNT case, resulting in lower MR. High spin filtration is observed in PC and APC for pristine, stretched and twisted structures at all applied voltages. In APC, at low voltages spin filtration in stretched CNT is higher than in pristine and twisted ones, with pristine giving a higher spin filtration than twisted CNT.

Comparative analysis of hepatopulmonary shunt obtained from pretherapy 99mTc MAA scintigraphy and post-therapy 90Y Bremsstrahlung imaging in 90Y microsphere therapy.

Science.gov (United States)

Jha, Ashish Kumar A; Zade, Anand A; Rangarajan, Venkatesh; Purandare, Nilendu; Shah, Sneha A; Agrawal, Archi; Kulkarni, Suyash S; Shetty, Nitin

2012-05-01

(99m)Tc macroaggregate albumin (MAA) scintigraphy is routinely used to estimate the hepatopulmonary shunt (HPS) of (90)Y microspheres because of their comparable average particle sizes (20-30 µm). However, the MAA particle size can vary from 10 to 90 µm. Therefore, HPS computed from (99m)Tc MAA scintigraphy may not accurately represent the HPS of (90)Y microspheres. In view of this, the present study was undertaken to investigate the accuracy of (99m)Tc MAA scintigraphy in estimating the HPS of (90)Y microspheres. Nineteen sessions of transarterial radioembolization using (90)Y therasphere were carried out in 17 patients for hepatic malignancies (both primary and secondary). For each session of therapy, a pretherapeutic (99m)Tc MAA scintigraphy and post-therapeutic (90)Y Bremsstrahlung scintigraphy were performed. The HPSs obtained from these images were compared. The mean HPS fractions calculated from the pretherapeutic (99m)Tc MAA study and the post-therapeutic (90)Y Bremsstrahlung images were 4.77 ± 2.81 and 4.52 ± 2.5%, respectively. The coefficient of correlation (r) was 0.96. (99m)Tc MAA scintigraphy accurately predicts the HPS of (90)Y microspheres.

Chirality-controlled spontaneous twisting of crystals due to thermal topochemical reaction.

Science.gov (United States)

Rai, Rishika; Krishnan, Baiju P; Sureshan, Kana M

2018-03-20

Crystals that show mechanical response against various stimuli are of great interest. These stimuli induce polymorphic transitions, isomerizations, or chemical reactions in the crystal and the strain generated between the daughter and parent domains is transcribed into mechanical response. We observed that the crystals of modified dipeptide LL (N 3 -l-Ala-l-Val-NHCH 2 C≡CH) undergo spontaneous twisting to form right-handed twisted crystals not only at room temperature but also at 0 °C over time. Using various spectroscopic techniques, we have established that the twisting is due to the spontaneous topochemical azide-alkyne cycloaddition (TAAC) reaction at room temperature or lower temperatures. The rate of twisting can be increased by heating, exploiting the faster kinetics of the TAAC reaction at higher temperatures. To address the role of molecular chirality in the direction of twisting the enantiomer of dipeptide LL, N 3 -d-Ala-d-Val-NHCH 2 C≡CH (DD), was synthesized and topochemical reactivity and mechanoresponse of its crystals were studied. We have found that dipeptide DD not only underwent TAAC reaction, giving 1,4-triazole-linked pseudopolypeptides of d-amino acids, but also underwent twisting with opposite handedness (left-handed twisting), establishing the role of molecular chirality in controlling the direction of mechanoresponse. This paper reports ( i ) a mechanical response due to a thermal reaction and ( ii ) a spontaneous mechanical response in crystals and ( iii ) explains the role of molecular chirality in the handedness of the macroscopic mechanical response.

Rapid radiochemical methods for preparation of sup(99m)Tc labelled compounds

International Nuclear Information System (INIS)

Narasimhan, D.V.S.; Banodkar, S.M.; Kothari, K.; Mani, R.S.

1981-01-01

Several inorganic and organic compounds incorporating sup( 99 m)Tc are being extensively used for imaging various body organs. The preparation of these sup( 99 m)Tc compounds with the necessary purity requirements is carried out by controlled reduction of sup( 99 m)Tc-pertechnetate using Sn(II) ions as the reducing agent followed by complexation with various active ingredients. The authors here present procedures developed at Radiopharmaceuticals Section of BARC for preparing sup( 99 m)Tc-diphosphonate, sup( 99 m)Tc-glucoheptonate, sup( 99 m)Tc-albumin microspheres and sup( 99 m)Tc-phytate with high radiochemical purity. The paper also describes procedures for the preparation of freeze-dried kits for single step preparation of these compounds. The paper also describes the authors' experience with various analytical procedures for the determination of radiochemical purity of these preparations. (author)

Preparation and labelling hydroxyapatite with 223Ra and 99mTc

International Nuclear Information System (INIS)

Malkova, E.; Micolova, P.; Vlk, M.; Kozempel, J.; Rabyk, M.

2015-01-01

The aim of this study was the preparation, studies and investigation of novel nanoparticles suitable for targeted delivery of 223 Ra and 99 mTc. Preliminary experiments were focused on the synthesis of hydroxyapatite nanoparticles (HANPs) and their affinity to 223 Ra and 99m Tc. Technetium-99m ( 99 mTc, T 1 /2 = 6.0 h) is the most commonly used medical radionuclide for diagnostic procedures. Radium-223 is the first -emitting radionuclide approved for targeted radionuclide therapy. The physical half-life of 223 Ra of 11.4 days is providing sufficient time for the synthesis, distribution and administration of the radiopharmaceutical to patients. HANPs labelling yields with 223 Ra were 95 - 100 % and with 99m Tc were 93 - 94 % depending on the reaction conditions. HANPs were studied on FT-IR (Fourier transform infrared spectroscopy), XRPD (X-Ray Powder Diffraction), DLS (Dynamic Light Scattering), and the sizes of nanoparticles were studied at temperatures 80, 120 and 200 grad C. (authors)

On the twists of interplanetary magnetic flux ropes observed at 1 AU

Science.gov (United States)

Wang, Yuming; Zhuang, Bin; Hu, Qiang; Liu, Rui; Shen, Chenglong; Chi, Yutian

2016-10-01

Magnetic flux ropes (MFRs) are one kind of fundamental structures in the solar/space physics and involved in various eruption phenomena. Twist, characterizing how the magnetic field lines wind around a main axis, is an intrinsic property of MFRs, closely related to the magnetic free energy and stableness. Although the effect of the twist on the behavior of MFRs had been widely studied in observations, theory, modeling, and numerical simulations, it is still unclear how much amount of twist is carried by MFRs in the solar atmosphere and in heliosphere and what role the twist played in the eruptions of MFRs. Contrasting to the solar MFRs, there are lots of in situ measurements of magnetic clouds (MCs), the large-scale MFRs in interplanetary space, providing some important information of the twist of MFRs. Thus, starting from MCs, we investigate the twist of interplanetary MFRs with the aid of a velocity-modified uniform-twist force-free flux rope model. It is found that most of MCs can be roughly fitted by the model and nearly half of them can be fitted fairly well though the derived twist is probably overestimated by a factor of 2.5. By applying the model to 115 MCs observed at 1 AU, we find that (1) the twist angles of interplanetary MFRs generally follow a trend of about 0.6l/R radians, where l/R is the aspect ratio of a MFR, with a cutoff at about 12π radians AU-1, (2) most of them are significantly larger than 2.5π radians but well bounded by 2l/R radians, (3) strongly twisted magnetic field lines probably limit the expansion and size of MFRs, and (4) the magnetic field lines in the legs wind more tightly than those in the leading part of MFRs. These results not only advance our understanding of the properties and behavior of interplanetary MFRs but also shed light on the formation and eruption of MFRs in the solar atmosphere. A discussion about the twist and stableness of solar MFRs are therefore given.

Twisting the Mirror TBA

NARCIS (Netherlands)

Arutyunov, G.E.; de Leeuw, M.; van Tongeren, S.J.

2010-01-01

We study finite-size corrections to the magnon dispersion relation in three models which differ from string theory on AdS5 x S5 in their boundary conditions. Asymptotically, this is accomplished by twisting the transfer matrix in a way which manifestly preserves integrability. In model I all

Finite element and analytical models for twisted and coiled actuator

Science.gov (United States)

Tang, Xintian; Liu, Yingxiang; Li, Kai; Chen, Weishan; Zhao, Jianguo

2018-01-01

Twisted and coiled actuator (TCA) is a class of recently discovered artificial muscle, which is usually made by twisting and coiling polymer fibers into spring-like structures. It has been widely studied since discovery due to its impressive output characteristics and bright prospects. However, its mathematical models describing the actuation in response to the temperature are still not fully developed. It is known that the large tensile stroke is resulted from the untwisting of the twisted fiber when heated. Thus, the recovered torque during untwisting is a key parameter in the mathematical model. This paper presents a simplified model for the recovered torque of TCA. Finite element method is used for evaluating the thermal stress of the twisted fiber. Based on the results of the finite element analyses, the constitutive equations of twisted fibers are simplified to develop an analytic model of the recovered torque. Finally, the model of the recovered torque is used to predict the deformation of TCA under varying temperatures and validated against experimental results. This work will enhance our understanding of the deformation mechanism of TCAs, which will pave the way for the closed-loop position control.

Evaluation of sup(99m)Tc labeled amino acids as radiopharmaceuticals, 4. S-substituted cysteines and N-substituted iminodiacetic acids

Energy Technology Data Exchange (ETDEWEB)

Karube, Yoshiharu; Maeda, Tatsuo; Ohya, Masato; Sugata, Setsuro; Kono, Akira (Kyushu Cancer Center Research Inst., Fukuoka (Japan)); Matsushima, Yoshikazu

1982-06-01

Sixteen sup(99m)Tc labeled ligands were evaluated as scintigraphic agents. The ligands studied were cysteine, glutathione, their S-substituted derivatives, lysine-N sup(epsilon), N sup(epsilon)-diacetic acid, glycylglycine-N,N-diacetic acid, glycylglycylglycine-N,N-diacetic acid, taurine-N,N-diacetic acid, hydrazine-N,N-diacetic acid, ethylenediamine-N,N-diacetic acid, and propylne-1,3-diamine-N/sup 1/-,N/sup 1/-diacetic acid. The ligands were labeled with sup(99m)Tc by the SnCl/sub 2/ method with more than 95% yield. The in vivo behavior of the sup(99m)Tc labeled ligands were studied in golden hamsters and dogs. The organ distribution in golden hamsters indicated clearance both by hepatobiliary and renal systems. The pancreas/blood ratios were much lower in the sup(99m)Tc ligands than in /sup 75/Se-selenomethionine. Scintigraphic studies in dogs showed that the liver and kidneys were well visualized but the accumulation by the pancreas was not sufficient for clear visualization.

New dualities and misleading anomaly matchings from outer-automorphism twists

Energy Technology Data Exchange (ETDEWEB)

Pal, Sridip; Song, Jaewon [Department of Physics, University of California, San Diego,La Jolla, CA 92093 (United States)

2017-03-29

We study four-dimensional N=1,2 superconformal theories in class S obtained by compactifying the 6d N=(2,0) theory on a Riemann surface C with outer-automorphism twist lines. From the pair-of-pants decompositions of C, we find various dual descriptions for the same theory having distinct gauge groups. We show that the various configurations of the twist line give rise to dual descriptions for the identical theory. We compute the ’t Hooft anomaly coefficients and the superconformal indices to test dualities. Surprisingly, we find that the class S theories with twist lines wrapping 1-cycles of C have the identical ’t Hooft anomalies as the ones without the twist line, whereas the superconformal indices differ. This provides a large set of examples where the anomaly matching is insufficient to test dualities.

Leading twist moments of the neutron structure function F_2n

Energy Technology Data Exchange (ETDEWEB)

M. Osipenko; W. Melnitchouk; S. Simula; S. Kulagin; G. Ricco

2005-10-20

We perform a global analysis of neutron $F_2^n$ structure function data, obtained by combining proton and deuteron measurements over a large range of kinematics. From these data the lowest moments ($n \\leq 10$) of the leading twist neutron $F_2^n$ structure function are extracted. Particular attention is paid to nuclear effects in the deuteron, which become increasingly important for the higher moments. Our results for the nonsinglet, isovector $p - n$ combination of the leading twist moments are compared with those of available lattice simulations. We also determine the lowest few moments of the higher twist contributions, obtained by subtracting the leading twist from the total structure function, and analyze their isospin dependence.

Intermittent energy bursts and recurrent topological change of a twisting magnetic flux tube

International Nuclear Information System (INIS)

Amo, Hiroyoshi; Sato, Tetsuya; Kageyama, Akira.

1994-09-01

When continuously twisted, a magnetic flux tube suffers a large kink distortion in the middle part of the tube, like a knot-of-tension instability of a bundle of twisted rubber strings, and reconnection is triggered starting with the twisted field lines and quickly proceeding to the untwisted field lines at the twist-untwist boundary, whereby a giant burst-like energy release takes place. Subsequently, bursts occur intermittently and reconnection advances deeper into the untwisted region. Then, a companion pair of the linked twist-untwist flux tubes reconnect with each other to return to the original axisymmetric tube. The process is thus repeatable. (author)

A Transformation Called "Twist"

Science.gov (United States)

Hwang, Daniel

2010-01-01

The transformations found in secondary mathematics curriculum are typically limited to stretches and translations (e.g., ACARA, 2010). Advanced students may find the transformation, twist, to be of further interest. As most available resources are written for professional-level readers, this article is intended to be an introduction accessible to…

Stability of coupled tearing and twisting modes in tokamaks

International Nuclear Information System (INIS)

Fitzpatrick, R.

1994-03-01

A dispersion relation is derived for resistive modes of arbitrary parity in a tokamak plasma. At low mode amplitude, tearing and twisting modes which have nonideal MHD behavior at only one rational surface at a time in the plasma are decoupled via sheared rotation and diamagnetic flows. At higher amplitude, more unstable open-quote compound close-quote modes develop which have nonideal behavior simultaneously at many surfaces. Such modes possess tearing parity layers at some of the nonideal surfaces, and twisting parity layers at others, but mixed parity layers are generally disallowed. At low mode number, open-quote compound close-quote modes are likely to have tearing parity layers at all of the nonideal surfaces in a very low-β plasma, but twisting parity layers become more probable as the plasma β is increased. At high mode number, unstable twisting modes which exceed a critical amplitude drive conventional magnetic island chains on alternate rational surfaces, to form an interlocking structure in which the O-points and X-points of neighboring chains line up

Quality audit programme for {sup 99m}Tc and {sup 131}I radioactivity measurements with radionuclide calibrators

Energy Technology Data Exchange (ETDEWEB)

Joseph, Leena [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)], E-mail: leena@barc.gov.in; Anuradha, R.; Kulkarni, D.B. [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2008-06-15

The use of radiopharmaceuticals in nuclear medicine for diagnosis and therapy has increased over the years with {sup 99m}Tc and {sup 131}I being most widely used. Quality audit programmes for radioactivity measurements of {sup 131}I have been ongoing and the 12th audit was recently conducted among seventy nuclear medicine centres (NMC) in India. An audit for the activity measurements of {sup 99m}Tc was conducted for the first time among ten NMCs in Mumbai, India. These programmes for radioactivity measurements have become very important to establish traceability of measurements to national and international standards and ensure accurate calibration of radionuclide calibrators. The results of both the audits are very encouraging. Ninety-four percent of the NMCs for {sup 131}I activity measurements were within a window of {+-}10% and for {sup 99m}Tc one NMC was deviating more than {+-}10%. The methodology adopted for the audit and results are discussed in detail in this paper.

Compensation of Cross-Contamination in Simultaneous 201Tl/99mTc Myocardial Perfusion SPECT Imaging

Directory of Open Access Journals (Sweden)

Faraz Kalantari

2009-12-01

Full Text Available Introduction: It is a common protocol to use 201Tl for the rest and 99mTc for the stress cardiac SPECT imaging. Theoretically, both types of imaging may be performed simultaneously using different energy windows for each radionuclide. However, a potential limitation is the cross-contamination of scattered photons from 99mTc and collimator X-rays into the 201Tl energy window. We used a middle energy window method to correct this cross-contamination. Material and Methods: Using NCAT, a typical software torso phantom was generated. An extremely thin line source of 99mTc activity was placed inside the cardiac region of the phantom and no activity in the other parts.  The SimSET Monte Carlo simulator was used to image the phantom in different energy windows. To find the relationship between projections in different energy windows, deconvolution theory was used. We investigated the ability of the suggested functions in three steps: Monte Carlo simulation, phantom experiment and clinical study. In the last step, SPECT images of eleven patients who had angiographic data were acquired in different energy windows. All of these images were compared by determining the contrast between a defect or left ventricle cavity and the myocardium. Results: We found a new 2D kernel which had an exponential pattern with a much higher center. This function was used for modeling 99mTc down scatter distribution from the middle window image. X-ray distribution in the 201Tl window was also modeled as the 99mTc photopeak image convolved by a Gaussian function. Significant improvements in the contrasts of the simultaneous dual 201Tl images were found in each step before and after reconstruction. In comparison with other similar methods, better results were acquired using our suggested functions. Conclusion: Our results showed contrast improvement in thallium images after correction, however, many other parameters should be evaluated for clinical approaches. There are many

{sup 99m}Tc-3PRGD{sub 2} SPECT to monitor early response to neoadjuvant chemotherapy in stage II and III breast cancer

Energy Technology Data Exchange (ETDEWEB)

Ji, Bin; Chen, Bin; Wang, Ting; Chen, Minglong; Ji, Tiefeng; Gao, Shi; Ma, Qingjie [China-Japan Union Hospital of Jilin University, Department of Nuclear Medicine, Changchun (China); Song, Yan [China-Japan Union Hospital of Jilin University, Department of Breast Surgery, Changchun (China); Wang, Xueju [China-Japan Union Hospital of Jilin University, Department of Pathology, Changchun (China)

2015-08-15

Monitoring of response to neoadjuvant chemotherapy (NCT) is important for optimal management of patients with breast cancer. {sup 99m}Tc-3PRGD{sub 2} SPECT is a newly developed imaging modality for evaluating tumor vascular status. In this study, we investigated the application of {sup 99m}Tc-3PRGD{sub 2} SPECT in evaluating therapy response to NCT in patients with stage II or III breast cancer. Thirty-three patients were scheduled to undergo {sup 99m}Tc-3PRGD{sub 2} SPECT at baseline, after the first and second cycle of NCT. Four patients had extremely low {sup 99m}Tc-3PRGD{sub 2} uptake at baseline, and were not included in the subsequent studies. Changes in tumor to nontumor (T/N) ratio were compared with pathological tumor responses classified using the residual cancer burden system. Receiver operator characteristic analysis was used to compare the power to identify responders between the end of the first and the end of the second cycle of NCT. The impact of breast cancer subtype on {sup 99m}Tc-3PRGD{sub 2} uptake was evaluated. The correlation between {sup 99m}Tc-3PRGD{sub 2} uptake and pathological tumor response was also evaluated in each breast cancer subtype. Surgery was performed after four cycles of NCT and pathological analysis revealed 18 responders and 15 nonresponders. In patients with clearly visible {sup 99m}Tc-3PRGD{sub 2} uptake at baseline, the sensitivity, specificity, and negative predictive value of {sup 99m}Tc-3PRGD{sub 2} SPECT were 86.7 %, 85.7 % and 86.7 % after the first cycle of NCT, and 92.9 %, 93.3 % and 93.3 % after the second cycle, respectively. Among these patients, the HER-2-positive group demonstrated both higher T/N ratios and a greater change in T/N ratio than patients with other breast cancer subtypes (P < 0.05). A strong correlation was found between changes in T/N ratio and pathological tumor response in the HER-2-positive group (P < 0.03). {sup 99m}Tc-3PRGD{sub 2} SPECT seems to be useful for determining the pathological

Design optimization for active twist rotor blades

Science.gov (United States)

Mok, Ji Won

This dissertation introduces the process of optimizing active twist rotor blades in the presence of embedded anisotropic piezo-composite actuators. Optimum design of active twist blades is a complex task, since it involves a rich design space with tightly coupled design variables. The study presents the development of an optimization framework for active helicopter rotor blade cross-sectional design. This optimization framework allows for exploring a rich and highly nonlinear design space in order to optimize the active twist rotor blades. Different analytical components are combined in the framework: cross-sectional analysis (UM/VABS), an automated mesh generator, a beam solver (DYMORE), a three-dimensional local strain recovery module, and a gradient based optimizer within MATLAB. Through the mathematical optimization problem, the static twist actuation performance of a blade is maximized while satisfying a series of blade constraints. These constraints are associated with locations of the center of gravity and elastic axis, blade mass per unit span, fundamental rotating blade frequencies, and the blade strength based on local three-dimensional strain fields under worst loading conditions. Through pre-processing, limitations of the proposed process have been studied. When limitations were detected, resolution strategies were proposed. These include mesh overlapping, element distortion, trailing edge tab modeling, electrode modeling and foam implementation of the mesh generator, and the initial point sensibility of the current optimization scheme. Examples demonstrate the effectiveness of this process. Optimization studies were performed on the NASA/Army/MIT ATR blade case. Even though that design was built and shown significant impact in vibration reduction, the proposed optimization process showed that the design could be improved significantly. The second example, based on a model scale of the AH-64D Apache blade, emphasized the capability of this framework to

κ-Minkowski spacetime as the result of Jordanian twist deformation

International Nuclear Information System (INIS)

Borowiec, A.; Pachol, A.

2009-01-01

Two one-parameter families of twists providing κ-Minkowski * product deformed spacetime are considered: Abelian and Jordanian. We compare the derivation of quantum Minkowski space from two perspectives. The first one is the Hopf module algebra point of view, which is strictly related with Drinfeld's twisting tensor technique. The other one relies on an appropriate extension of ''deformed realizations'' of nondeformed Lorentz algebra by the quantum Minkowski algebra. This extension turns out to be de Sitter Lie algebra. We show the way both approaches are related. The second path allows us to calculate deformed dispersion relations for toy models ensuing from different twist parameters. In the Abelian case, one recovers κ-Poincare dispersion relations having numerous applications in doubly special relativity. Jordanian twists provide a new type of dispersion relations which in the minimal case (related to Weyl-Poincare algebra) takes an energy-dependent linear mass deformation form.

Flow cytometry protocols

National Research Council Canada - National Science Library

Jaroszeski, Mark J; Heller, Richard

1998-01-01

... are individually analyzed, and it is typical for flow cytometers to quantitatively process thousands of individual particles in a matter of seconds. This a powerful analytic feat particularly if one relates it to the time required to examine several thousand individual cells using a microscope. This leaves little doubt regarding why the field of flow cytometry has...

Detection of metastatic bone cancer by scintiscanning with sup(99m)Tc labelled sodium pyrophosphate

International Nuclear Information System (INIS)

Kromer, Bernard.

1973-01-01

Bone scanning with sup(99m)Tc sodium pyrophosphate was performed in 65 patients with primary neoplasms, using a gamma-camera. The scans are compared to those obtained with 85 Sr and 87 Sr. Sup(99m)Tc appears to be superior to the other two in the detection of metastatic bone lesions, mainly because of its physical characteristics (high yield of 140 KeV photons, short physical half-life). The advantages related to these characteristics are emphasized: possibility of rapid and systematic investigation of the whole skeleton using a gamma-camera; low dose irradiation of the patient which enables frequent repetitive studies to be performed [fr

Performance improvement of small-scale rotors by passive blade twist control

OpenAIRE

Lv, Peng; Prothin, Sebastien; Mohd Zawawi, Fazila; Bénard, Emmanuel; Morlier, Joseph; Moschetta, Jean-Marc

2015-01-01

A passive twist control is proposed as an adaptive way to maximize the overall efficiency of the small-scale rotor blade for multifunctional aircrafts. Incorporated into a database of airfoil characteristics, Blade Element Momentum Theory is implemented to obtain the blade optimum twist rates for hover and forward flight. In order to realize the required torsion of blade between hover and forward flight, glass/epoxy laminate blade is proposed based on Centrifugal Force Induced Twist concept. ...

Unique CCT repeats mediate transcription of the TWIST1 gene in mesenchymal cell lines

International Nuclear Information System (INIS)

Ohkuma, Mizue; Funato, Noriko; Higashihori, Norihisa; Murakami, Masanori; Ohyama, Kimie; Nakamura, Masataka

2007-01-01

TWIST1, a basic helix-loop-helix transcription factor, plays critical roles in embryo development, cancer metastasis and mesenchymal progenitor differentiation. Little is known about transcriptional regulation of TWIST1 expression. Here we identified DNA sequences responsible for TWIST1 expression in mesenchymal lineage cell lines. Reporter assays with TWIST1 promoter mutants defined the -102 to -74 sequences that are essential for TWIST1 expression in human and mouse mesenchymal cell lines. Tandem repeats of CCT, but not putative CREB and NF-κB sites in the sequences substantially supported activity of the TWIST1 promoter. Electrophoretic mobility shift assay demonstrated that the DNA sequences with the CCT repeats formed complexes with nuclear factors, containing, at least, Sp1 and Sp3. These results suggest critical implication of the CCT repeats in association with Sp1 and Sp3 factors in sustaining expression of the TWIST1 gene in mesenchymal cells

Valve-aided twisted Savonius rotor

Energy Technology Data Exchange (ETDEWEB)

Jaya Rajkumar, M.; Saha, U.K.

2006-05-15

Accessories, such as end plates, deflecting plates, shielding and guide vanes, may increase the power of a Savonius rotor, but make the system structurally complex. In such cases, the rotor can develop a relatively large torque at small rotational speeds and is cheap to build, however it harnesses only a small fraction of the incident wind energy. Another proposition for increasing specific output is to place non-return valves inside the concave side of the blades. Such methods have been studied experimentally with a twisted-blade Thus improving a Savonius rotor's energy capture. This new concept has been named as the 'Valve-Aided Twisted Savonius'rotor. Tests were conducted in a low-speed wind tunnel to evaluate performance. This mechanism is found to be independent of flow direction, and shows potential for large machines. [Author].

Twisting failure of centrally loaded open-section columns in the elastic range

Science.gov (United States)

Kappus, Robert

1938-01-01

In the following report a complete theory of twisting failure by the energy method is developed, based on substantially the same assumptions as those employed by Wagner and Bleich. Problems treated in detail are: the stress and strain condition under St. Venant twist and in twist with axial constraint; the concept of shear center and the energy method for problems of elastic stability.

Exploring exotic states with twisted boundary conditions

International Nuclear Information System (INIS)

Agadjanov, Dimitri

2017-01-01

he goal of this thesis is to develop methods to study the nature and properties of exotic hadrons from lattice simulations. The main focus lies in the application of twisted boundary conditions. The thesis consists of a general introduction and the collection of three papers, represented respectively in three chapters. The introduction of the thesis reviews the theoretical background, which is further used in the rest of the thesis. Further implementing partially twisted boundary conditions in the scalar sector of lattice QCD is studied. Then we develop a method to study the content of the exotic hadrons by determining the wave function renormalization constant from lattice simulations, exploiting the dependence of the spectrum on the twisted boundary conditions. The final chapter deals with a novel method to study the multi-channel scattering problem in a finite volume, which is relevant for exotic states. Its key idea is to extract the complex hadron-hadron optical potential, avoiding the difficulties, associated with the solution of the multi-channel Luescher equation.

Exploring exotic states with twisted boundary conditions

Energy Technology Data Exchange (ETDEWEB)

Agadjanov, Dimitri

2017-09-11

he goal of this thesis is to develop methods to study the nature and properties of exotic hadrons from lattice simulations. The main focus lies in the application of twisted boundary conditions. The thesis consists of a general introduction and the collection of three papers, represented respectively in three chapters. The introduction of the thesis reviews the theoretical background, which is further used in the rest of the thesis. Further implementing partially twisted boundary conditions in the scalar sector of lattice QCD is studied. Then we develop a method to study the content of the exotic hadrons by determining the wave function renormalization constant from lattice simulations, exploiting the dependence of the spectrum on the twisted boundary conditions. The final chapter deals with a novel method to study the multi-channel scattering problem in a finite volume, which is relevant for exotic states. Its key idea is to extract the complex hadron-hadron optical potential, avoiding the difficulties, associated with the solution of the multi-channel Luescher equation.

Precision measurement of the half-life of {sup 90m}Nb and {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Kikunaga, H.; Fujisawa, H.; Ooe, K. [Osaka Univ., Toyonaka (Japan). Graduate School of Science] [and others

2011-07-01

We have produced {sup 90m}Nb and {sup 99m}Tc in the reactions of {sup nat}Zr(p, xn){sup 90m}Nb and {sup 100}Mo({gamma}, n){sup 99}Mo, followed by disintegration to {sup 99m}Tc, respectively, and measured the halflives of these nuclides by using a reference source method. In order to determine the short half-lives of {sup 90m}Nb precisely, an on-line gas-jet system has been employed. As a result, the half-lives of these nuclides were determined with good precision on the order of magnitude of 0.1%. (orig.)

Measurement of curvature and twist of a deformed object using digital holography

International Nuclear Information System (INIS)

Chen Wen; Quan Chenggen; Cho Jui Tay

2008-01-01

Measurement of curvature and twist is an important aspect in the study of object deformation. In recent years, several methods have been proposed to determine curvature and twist of a deformed object using digital shearography. Here we propose a novel method to determine the curvature and twist of a deformed object using digital holography and a complex phasor. A sine/cosine transformation method and two-dimensional short time Fourier transform are proposed subsequently to process the wrapped phase maps. It is shown that high-quality phase maps corresponding to curvature and twist can be obtained. An experiment is conducted to demonstrate the validity of the proposed method

Twisted quantum doubles

Directory of Open Access Journals (Sweden)

Daijiro Fukuda

2004-01-01

Full Text Available Using diagrammatic pictures of tensor contractions, we consider a Hopf algebra (Aop⊗ℛλA** twisted by an element ℛλ∈A*⊗Aop corresponding to a Hopf algebra morphism λ:A→A. We show that this Hopf algebra is quasitriangular with the universal R-matrix coming from ℛλ when λ2=idA, generalizing the quantum double construction which corresponds to the case λ=idA.

Development of methods of labeling pentavalent DMSA with {sup 99m}Tc and {sup 188}Re; Desenvolvimento de metodos para marcacao de DMSA pentavalente com {sup 99m}Tc e {sup 188}Re

Energy Technology Data Exchange (ETDEWEB)

Brambilla, Tania de Paula, email: jtoniolo@ipen.br

2009-07-01

Technetium-99 m is the most useful radionuclide in diagnostic imaging procedures in Nuclear Medicine, more than 80 percent of radiopharmaceuticals are {sup 99m}Tc-labeled compounds. {sup 99m}Tc-DMSA(V) has been used for imaging of soft tissue, head and neck tumors. It shows a particularly high specificity for medullary thyroid carcinoma and bone metastases in a variety of cancers. Biodistribution studies of {sup 188}Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of {sup 99m}Tc-DMSA(V), so this agent could be used for targeted radiotherapy of these tumors. The aim of this work is the development of methods of labeling DMSA(V) with {sup 99m}Tc and {sup 188}Re. {sup 99m}Tc-DMSA(V) can be prepared by two methods. One of them is the indirect one, through the use of a commercial kit of DMSA (III), by adjusting the pH from 2.5 to {approx} 8.5 with NaHCO{sub 3}. This method was evaluated and optimized presenting high labeling yields. The other method is the direct one, through the preparation of a lyophilised kit ready for labeling with {sup 99m}Tc, being the method of interest of this work, due to the easy of its clinical use. The most adequate formulation of the kit was: 1.71 mg of DMSA, 0.53 mg of SnCl{sub 2}.2H{sub 2}O and 0.83 mg of ascorbic acid (pH 9). Labeling yields higher than 95% were achieved labeling this kit with 1 to 2 m L of {sup 99m}Tc with activities up to 4736 MBq (128 mCi). The kit was stable up to 6 months and biodistribution studies confirmed the quality of the DMSA (V) labeled with {sup 99m}Tc using this kit. The reduction potential of Re is lower than the one for Tc, so the labeling conditions of {sup 188}Re-DMSA(V) are different from the ones used for {sup 99m}Tc- DMSA(V). {sup 188}Re-DMSA(V) is prepared in acid solution, that makes it possible to use the DMSA (III) commercial kit developed for labeling with {sup 99m}Tc, prepared in pH 2.5, for labeling with {sup 188}Re. Labeling yields higher than 95% were

Structural and electronic transformation in low-angle twisted bilayer graphene

Science.gov (United States)

Gargiulo, Fernando; Yazyev, Oleg V.

2018-01-01

Experiments on bilayer graphene unveiled a fascinating realization of stacking disorder where triangular domains with well-defined Bernal stacking are delimited by a hexagonal network of strain solitons. Here we show by means of numerical simulations that this is a consequence of a structural transformation of the moiré pattern inherent to twisted bilayer graphene taking place at twist angles θ below a crossover angle θ\\star=1.2\\circ . The transformation is governed by the interplay between the interlayer van der Waals interaction and the in-plane strain field, and is revealed by a change in the functional form of the twist energy density. This transformation unveils an electronic regime characteristic of vanishing twist angles in which the charge density converges, though not uniformly, to that of ideal bilayer graphene with Bernal stacking. On the other hand, the stacking domain boundaries form a distinct charge density pattern that provides the STM signature of the hexagonal solitonic network.

Technetium /sup 99m/Tc macroaggregated albumin lung scans. Use in chronic childhood asthma

International Nuclear Information System (INIS)

Hyde, J.S.; Koch, D.F.; Isenberg, P.D.; Werner, P.

1976-01-01

Serial roentgenograms and technetium /sub 99m/Tc macroaggregated albumin lung scans were done simultaneously in 30 bronchodilator-dependent asthmatic children and young adults during both relative remission and attacks of status asthmaticus. When chest roentgenograms showed air trapping and increased peribronchial vascular markings associated with persistent perfusion defects, the children benefited from further laboratory studies and continuous comprehensive therapy. Serial scans provided information about underperfusion that was not discernible either by roentgenograms or by usual blood gas studies. Also, lung scans are easier to obtain in children with long-standing asthma than are detailed pulmonary tests. In our study, technetium /sup 99m/Tc macroaggregated albumin scans showed persistent regional perfusion defects in 20 children with chronic asthma during relative remission and exacerbations

Transfer of 131I and /sup 95m/Tc from pasture to goat milk

International Nuclear Information System (INIS)

Bondietti, E.A.; Garten, C.T. Jr.

1984-01-01

Field measurements were made in 1983 on the transfer of 131 I and /sup 95m/Tc from spray-contaminated pasture to goat's milk. The transfer of 131 I to milk was similar to that used for mathematical models in US Nuclear Regulatory Commission Regulatory Guide 1.109, which was derived from stall-feeding experiments using capsulized doses. Compared to 131 I, the /sup 95m/Tc transferred to milk was about 5600 times less. The lower transfer resulted from both immobilization of technetium on pasture prior to ingestion as well as reduced gastrointestinal absorption. The results show that the food chain transfer of technetium to milk is much less than that previously expected based on inferences made from metabolism studies. 6 references, 4 figures, 1 table

Innovation of Methods for Measurement and Modelling of Twisted Pair Parameters

Directory of Open Access Journals (Sweden)

Lukas Cepa

2011-01-01

Full Text Available The goal of this paper is to optimize a measurement methodology for the most accurate broadband modelling of characteristic impedance and other parameters for twisted pairs. Measured values and theirs comparison is presented in this article. Automated measurement facility was implemented at the Department of telecommunication of Faculty of electrical engineering of Czech technical university in Prague. Measurement facility contains RF switches allowing measurements up to 300 MHz or 1GHz. Measured twisted pair’s parameters can be obtained by measurement but for purposes of fundamental characteristics modelling is useful to define functions that model the properties of the twisted pair. Its primary and secondary parameters depend mostly on the frequency. For twisted pair deployment, we are interested in a frequency band range from 1 MHz to 100 MHz.

Unconfined twist : a simple method to prepare ultrafine grained metallic materials.

Energy Technology Data Exchange (ETDEWEB)

Zhao, Y. (Yonghao); Liao, Xiaozhou; Zhu, Y. T. (Yuntian Theodore)

2004-01-01

A new simple method - unconfined twist was employed to prepare ultrafine grained (UFG) Fe,wire. A coarse grained (CG) Fe wire with a diameter of 0.85 mm was fixed at one end, and twisted at the other end. After maximum twist before fracture, in the cross-sectional plane, concentrically deformed layers with a width of several micrometers formed surrounding the center axis of the wire. The near-surface deformed layers consist of lamella grains with a width in submicrometer range. In the longitudinal plane, deformed bands (with a width of several micrometers) formed uniformly, which were composed of lamella crystallites (with a width in submicrometer range). The tensile yield strength and ultimate strength of the twisted Fe wire are increased by about 150% and 100% compared with the values of its CG counterpart.

Anisotropic piezoelectric twist actuation of helicopter rotor blades: Aeroelastic analysis and design optimization

Science.gov (United States)

Wilkie, William Keats

1997-12-01

An aeroelastic model suitable for control law and preliminary structural design of composite helicopter rotor blades incorporating embedded anisotropic piezoelectric actuator laminae is developed. The aeroelasticity model consists of a linear, nonuniform beam representation of the blade structure, including linear piezoelectric actuation terms, coupled with a nonlinear, finite-state unsteady aerodynamics model. A Galerkin procedure and numerical integration in the time domain are used to obtain a soluti An aeroelastic model suitable for control law and preliminary structural design of composite helicopter rotor blades incorporating embedded anisotropic piezoelectric actuator laminae is developed. The aeroelasticity model consists of a linear, nonuniform beam representation of the blade structure, including linear piezoelectric actuation terms, coupled with a nonlinear, finite-state unsteady aerodynamics model. A Galerkin procedure and numerical integration in the time domain are used to obtain amited additional piezoelectric material mass, it is shown that blade twist actuation approaches which exploit in-plane piezoelectric free-stain anisotropies are capable of producing amplitudes of oscillatory blade twisting sufficient for rotor vibration reduction applications. The second study examines the effectiveness of using embedded piezoelectric actuator laminae to alleviate vibratory loads due to retreating blade stall. A 10 to 15 percent improvement in dynamic stall limited forward flight speed, and a 5 percent improvement in stall limited rotor thrust were numerically demonstrated for the active twist rotor blade relative to a conventional blade design. The active twist blades are also demonstrated to be more susceptible than the conventional blades to dynamic stall induced vibratory loads when not operating with twist actuation. This is the result of designing the active twist blades with low torsional stiffness in order to maximize piezoelectric twist authority

Achalasia diagnosed by {sup 99m}Tc pertechnetate scintigraphy; Diagnose einer Achalasie durch {sup 99m}Tc-Pertechnetat-Szintigraphie

Energy Technology Data Exchange (ETDEWEB)

Mikosch, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie; Gallowitsch, H.J. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie; Kresnik, E. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie; Lind, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin und Spezielle Endokrinologie

1997-06-01

A 73-year-old patient presented a {sup 99m}Tc scintiscan with a focal tracer accumulation left and caudal of the thyroid gland. Further investigations with sonography, CT, esophagoscopy and barium swallow provided the diagnosis of achalasia as the reason for focal {sup 99m}Tc retention caudal of the thyroid gland. Explanation for {sup 99m}Tc accumulation within the esophagus may be the nonspecific accumulation of {sup 99m}Tc not only in the thyroid gland but also in the salivary glands. Excretion of the tracer follows with the saliva. Structural and motor disorders of the esophagus can thus lead to focal tracer retention within the esophagus simulating thyroid tissue. (orig.) [Deutsch] Eine 73jaehrige Patientin zeigte bei der {sup 99m}Tc-Schilddruesenszintigraphie eine von der Schilddruese abgesetzte deutliche fokale Speicherung links kaudal der Schilddruese. Die weitere diagnostische Abklaerung mittels Sonographie, CT, Oesophagoskopie und videoassistiertem Kontrastmittelschluckakt ergab als Ursache der {sup 99m}Tc-Speicherung eine Achalasie. Die Erklaerung einer {sup 99m}Tc-Speicherung in der Speiseroehre waere die unspezifische {sup 99m}Tc-Aufnahme in den Speicheldruesen mit nachfolgender Tracerelimination ueber den Speichel. Depotbildungen von Speichel bei Erkrankungen der Speiseroehre, die mit einer Transportstoerung des Speichels verbunden sind, koennen dadurch Schilddruesengewebe vortaeuschen. (orig.)

An active, collaborative approach to learning skills in flow cytometry.

Science.gov (United States)

Fuller, Kathryn; Linden, Matthew D; Lee-Pullen, Tracey; Fragall, Clayton; Erber, Wendy N; Röhrig, Kimberley J

2016-06-01

Advances in science education research have the potential to improve the way students learn to perform scientific interpretations and understand science concepts. We developed active, collaborative activities to teach skills in manipulating flow cytometry data using FlowJo software. Undergraduate students were given compensated clinical flow cytometry listmode output (FCS) files and asked to design a gating strategy to diagnose patients with different hematological malignancies on the basis of their immunophenotype. A separate cohort of research trainees was given uncompensated data files on which they performed their own compensation, calculated the antibody staining index, designed a sequential gating strategy, and quantified rare immune cell subsets. Student engagement, confidence, and perceptions of flow cytometry were assessed using a survey. Competency against the learning outcomes was assessed by asking students to undertake tasks that required understanding of flow cytometry dot plot data and gating sequences. The active, collaborative approach allowed students to achieve learning outcomes not previously possible with traditional teaching formats, for example, having students design their own gating strategy, without forgoing essential outcomes such as the interpretation of dot plots. In undergraduate students, favorable perceptions of flow cytometry as a field and as a potential career choice were correlated with student confidence but not the ability to perform flow cytometry data analysis. We demonstrate that this new pedagogical approach to teaching flow cytometry is beneficial for student understanding and interpretation of complex concepts. It should be considered as a useful new method for incorporating complex data analysis tasks such as flow cytometry into curricula. Copyright © 2016 The American Physiological Society.

Effective potentials for twisted fields

International Nuclear Information System (INIS)

Banach, R.

1981-01-01

Minus the density of the effective action, evaluated at the lowest eigenfunction of the (space-time) derivative part of the second (functional) derivative of the classical action, is proposed as a generalised definition of the effective potential, applicable to twisted as well as untwisted sectors of a field theory. The proposal is corroborated by several specific calculations in the twisted sector, namely phi 4 theory (real and complex) and wrong-sign-Gordon theory, in an Einstein cylinder, where the exact integrability of the static solutions confirms the effective potential predictions. Both models exhibit a phase transition, which the effective potential locates, and the one-loop quantum shift in the critical radius is computed for the real phi 4 model, being a universal result. Topological mass generation at the classical level is pointed out, and the exactness of the classical effective potential approximation for complex phi 4 is discussed. (author)

Quantum communication through a spin ring with twisted boundary conditions

International Nuclear Information System (INIS)

Bose, S.; Jin, B.-Q.; Korepin, V.E.

2005-01-01

We investigate quantum communication between the sites of a spin ring with twisted boundary conditions. Such boundary conditions can be achieved by a magnetic flux through the ring. We find that a nonzero twist can improve communication through finite odd-numbered rings and enable high-fidelity multiparty quantum communication through spin rings (working near perfectly for rings of five and seven spins). We show that in certain cases, the twist results in the complete blockage of quantum-information flow to a certain site of the ring. This effect can be exploited to interface and entangle a flux qubit and a spin qubit without embedding the latter in a magnetic field

Microfluidic Impedance Flow Cytometry Enabling High-Throughput Single-Cell Electrical Property Characterization

Science.gov (United States)

Chen, Jian; Xue, Chengcheng; Zhao, Yang; Chen, Deyong; Wu, Min-Hsien; Wang, Junbo

2015-01-01

This article reviews recent developments in microfluidic impedance flow cytometry for high-throughput electrical property characterization of single cells. Four major perspectives of microfluidic impedance flow cytometry for single-cell characterization are included in this review: (1) early developments of microfluidic impedance flow cytometry for single-cell electrical property characterization; (2) microfluidic impedance flow cytometry with enhanced sensitivity; (3) microfluidic impedance and optical flow cytometry for single-cell analysis and (4) integrated point of care system based on microfluidic impedance flow cytometry. We examine the advantages and limitations of each technique and discuss future research opportunities from the perspectives of both technical innovation and clinical applications. PMID:25938973

Development of {sup 99m}Tc extraction-recovery by solvent extraction method

Energy Technology Data Exchange (ETDEWEB)

Kimura, Akihiro; Nishikata, Kaori; Izumo, Hironobu; Tsuchiya, Kunihiko; Ishihara, Masahiro [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan); Tanase, Masakazu; Fujisaki, Saburo; Shiina, Takayuki; Ohta, Akio; Takeuchi, Nobuhiro [Chiyoda Technol Corp., Tokyo (Japan)

2012-03-15

{sup 99m}Tc is used as a radiopharmaceutical in the medical field for the diagnosis, and manufactured from {sup 99}Mo, the parent nuclide. In this study, the solvent extraction with MEK was selected, and preliminary experiments were carried out using Re instead of {sup 99m}Tc. Two tests were carried out in the experiments; the one is the Re extraction test with MEK from Re-Mo solution, the other is the Re recovery test from the Re-MEK. As to the Re extraction test, and it was clear that the Re extraction yield was more than 90%. Two kinds of Re recovery tests, which are an evaporation method using the evaporator and an adsorption/elution method using the alumina column, were carried out. As to the evaporation method, the Re concentration in the collected solution increased more than 150 times. As to the adsorption/elution method, the Re concentration increased in the eluted solution more than 20 times. (author)

An aeroelastic analysis of helicopter rotor blades incorporating piezoelectric fiber composite twist actuation

Science.gov (United States)

Wilkie, W. Keats; Park, K. C.

1996-01-01

A simple aeroelastic analysis of a helicopter rotor blade incorporating embedded piezoelectric fiber composite, interdigitated electrode blade twist actuators is described. The analysis consist of a linear torsion and flapwise bending model coupled with a nonlinear ONERA based unsteady aerodynamics model. A modified Galerkin procedure is performed upon the rotor blade partial differential equations of motion to develop a system of ordinary differential equations suitable for numerical integration. The twist actuation responses for three conceptual full-scale blade designs with realistic constraints on blade mass are numerically evaluated using the analysis. Numerical results indicate that useful amplitudes of nonresonant elastic twist, on the order of one to two degrees, are achievable under one-g hovering flight conditions for interdigitated electrode poling configurations. Twist actuation for the interdigitated electrode blades is also compared with the twist actuation of a conventionally poled piezoelectric fiber composite blade. Elastic twist produced using the interdigitated electrode actuators was found to be four to five times larger than that obtained with the conventionally poled actuators.

Twist1 suppresses senescence programs and thereby accelerates and maintains mutant Kras-induced lung tumorigenesis.

Directory of Open Access Journals (Sweden)

Phuoc T Tran

Full Text Available KRAS mutant lung cancers are generally refractory to chemotherapy as well targeted agents. To date, the identification of drugs to therapeutically inhibit K-RAS have been unsuccessful, suggesting that other approaches are required. We demonstrate in both a novel transgenic mutant Kras lung cancer mouse model and in human lung tumors that the inhibition of Twist1 restores a senescence program inducing the loss of a neoplastic phenotype. The Twist1 gene encodes for a transcription factor that is essential during embryogenesis. Twist1 has been suggested to play an important role during tumor progression. However, there is no in vivo evidence that Twist1 plays a role in autochthonous tumorigenesis. Through two novel transgenic mouse models, we show that Twist1 cooperates with Kras(G12D to markedly accelerate lung tumorigenesis by abrogating cellular senescence programs and promoting the progression from benign adenomas to adenocarcinomas. Moreover, the suppression of Twist1 to physiological levels is sufficient to cause Kras mutant lung tumors to undergo senescence and lose their neoplastic features. Finally, we analyzed more than 500 human tumors to demonstrate that TWIST1 is frequently overexpressed in primary human lung tumors. The suppression of TWIST1 in human lung cancer cells also induced cellular senescence. Hence, TWIST1 is a critical regulator of cellular senescence programs, and the suppression of TWIST1 in human tumors may be an effective example of pro-senescence therapy.

Does the chocolate interfere with the radiolabelling of erythrocytes with 99 mTc?; Le chocolat interfere-t-il avec le radiomarquage des erythrocytes au 99 mTc?

Energy Technology Data Exchange (ETDEWEB)

Bustani, H.; Colavolpe, C.; Imbert-Joscht, I.; Moubarik, C.; Havlik, P.; Pisano, P.; Guillet, B. [Service de medecine nucleaire, CHU Nord, Marseille, (France)

2009-05-15

We present in this work the case of a failure of erythrocytes labelling with {sup 99m}Tc for a twenty five years old patient making the examination not interpretable. The patient reported that she drank a chocolate drink the morning before the examination. it is the first observation of a such interaction between the chocolate consumption. We do not have any explanation at this date, some compounds in the cocoa can be considered with caution. Some flavonoids (catechins and pro-cyanidins) modify the plasmatic and intra-erythrocyte oxido-reducer statute and could interact with the labelling (specific reduction of the {sup 99m}Tc pertechnetate in the middle of erythrocyte by the tin pyrophosphate. These compounds, as well as the methyl-xanthine-theobromine, seem modify the membrane permeability of erythrocytes and could interfere with the input of pyrophosphate or {sup 99m}Tc-pertechnetate in the middle of erythrocyte. these observations, in spite of preliminary ones, lead us to recommend near the patients to avoid the chocolate foods in the twenty four hours before this type of examinations. (N.C.)

Geometrically exact nonlinear analysis of pre-twisted composite rotor blades

Directory of Open Access Journals (Sweden)

Li'na SHANG

2018-02-01

Full Text Available Modeling of pre-twisted composite rotor blades is very complicated not only because of the geometric non-linearity, but also because of the cross-sectional warping and the transverse shear deformation caused by the anisotropic material properties. In this paper, the geometrically exact nonlinear modeling of a generalized Timoshenko beam with arbitrary cross-sectional shape, generally anisotropic material behavior and large deflections has been presented based on Hodges’ method. The concept of decomposition of rotation tensor was used to express the strain in the beam. The variational asymptotic method was used to determine the arbitrary warping of the beam cross section. The generalized Timoshenko strain energy was derived from the equilibrium equations and the second-order asymptotically correct strain energy. The geometrically exact nonlinear equations of motion were established by Hamilton’s principle. The established modeling was used for the static and dynamic analysis of pre-twisted composite rotor blades, and the analytical results were validated based on experimental data. The influences of the transverse shear deformation on the pre-twisted composite rotor blade were investigated. The results indicate that the influences of the transverse shear deformation on the static deformation and the natural frequencies of the pre-twisted composite rotor blade are related to the length to chord ratio of the blade. Keywords: Geometrically exact, Nonlinear, Pre-twisted composite blade, Transverse shear deformation, Variational asymptotic, Warping

A twisted flux-tube model for solar prominences. I. General properties

International Nuclear Information System (INIS)

Priest, E.R.; Hood, A.W.; Anzer, U.

1989-01-01

It is proposed that a solar prominence consists of cool plasma supported in a large-scale curved and twisted magnetic flux tube. As long as the flux tube is untwisted, its curvature is concave toward the solar surface, and so it cannot support dense plasma against gravity. However, when it is twisted sufficiently, individual field lines may acquire a convex curvature near their summits and so provide support. Cool plasma then naturally tends to accumulate in such field line dips either by injection from below or by thermal condensation. As the tube is twisted up further or reconnection takes place below the prominence, one finds a transition from normal to inverse polarity. When the flux tube becomes too long or is twisted too much, it loses stability and its true magnetic geometry as an erupting prominence is revealed more clearly. 56 refs

Report of the results of the International Clinical Cytometry Society and American Society for Clinical Pathology workload survey of clinical flow cytometry laboratories.

Science.gov (United States)

Wolniak, Kristy; Goolsby, Charles; Choi, Sarah; Ali, Asma; Serdy, Nina; Stetler-Stevenson, Maryalice

2017-11-01

Thorough review of current workload, staffing, and testing practices in clinical laboratories allows for optimization of laboratory efficiency and quality. This information is largely missing with regard to clinical flow cytometry laboratories. The purpose of this survey is to provide comprehensive, current, and accurate data on testing practices and laboratory staffing in clinical laboratories performing flow cytometric studies. Survey data was collected from flow cytometry laboratories through the ASCP website. Data was collected on the workload during a 1-year time period of full-time and part-time technical and professional (M.D./D.O./Ph.D. or equivalent) flow cytometry employees. Workload was examined as number of specimens and tubes per full time equivalent (FTE) technical and professional staff. Test complexity, test result interpretation, and reporting practices were also evaluated. There were 205 respondent laboratories affiliated predominantly with academic and health system institutions. Overall, 1,132 FTE employees were reported with 29% professional FTE employees and 71% technical. Fifty-one percent of the testing performed was considered high complexity and 49% was low complexity. The average number of tubes per FTE technologist was 1,194 per year and the average number of specimens per FTE professional was 1,659 per year. The flow cytometry reports were predominantly written by pathologists (57%) and were typically written as a separate report (58%). This survey evaluates the overall status of the current practice of clinical flow cytometry and provides a comprehensive dataset as a framework to help laboratory departments, directors, and managers make appropriate, cost-effective staffing decisions. © 2016 International Clinical Cytometry Society. © 2016 International Clinical Cytometry Society.

Preparation of clinical-scale 99Mo/99mTc column generator using neutron activated low specific activity 99Mo and nanocrystalline γ-Al2O3 as column matrix.

Science.gov (United States)

Chakravarty, Rubel; Ram, Ramu; Dash, Ashutosh; Pillai, M R A

2012-10-01

Preparation of clinical-scale (99)Mo/(99m)Tc generator using (n,γ) activated low specific activity (99)Mo and nanocrystalline γ-Al(2)O(3) as a high capacity sorbent matrix is attempted. Nanocrystalline γ-Al(2)O(3) was synthesized by 'solid state mechanochemical' reaction of aluminum nitrate with ammonium bicarbonate. Experimental parameters were optimized to effectively separate (99m)Tc from (99)Mo using this sorbent as the column matrix. The performance features of a 13 GBq (350 mCi) (99)Mo/(99m)Tc generator using this sorbent and (99)Mo produced by (n,γ) route having specific activity 12.9-18.5 GBq/g were evaluated for 10 days. The sorbent possessed the requisite selectivity for (99)Mo and demonstrated a maximum sorption capacity of 200 ± 5mg Mo/g, which is ~10 times higher than that of ordinary acidic alumina. The overall yield of (99m)Tc was >80%, with radionuclidic purity >99.99% and radiochemical purity >99%. The yield of (99m)Tc varied from 7.8 to 2.1 GBq in the eluate for the six days of operation of the generator. The radioactive concentration of (99m)Tc eluted was adequate for the formulation of radiopharmaceuticals. The performance of the generator remained consistent over an extended period of 10 days. The eluted (99m)Tc was suitable for the formulation of (99m)Tc-DMSA and (99m)Tc-EC resulting in high radiolabeling yields (>98%). The effectiveness of γ-Al(2)O(3) as a new generation sorbent in the development of clinically useful (99)Mo/(99m)Tc generator using low specific activity (99)Mo and yielding (99m)Tc with adequate radioactive concentration and high purity suitable for formulation of radiopharmaceuticals is demonstrated. Copyright © 2012 Elsevier Inc. All rights reserved.

Enhancement of heat transfer using varying width twisted tape inserts

African Journals Online (AJOL)

user

enhancement of heat transfer with twisted tape inserts as compared to plain ... studies for heat transfer and pressure drop of laminar flow in horizontal tubes ... flow in rectangular and square plain ducts and ducts with twisted-tape inserts .... presence of the insert in the pipe causes resistance to flow and increases turbulence.

Studies of monoclonal antibodies IOR-CEA-1 and IOR-EGF/R3 labelled with {sup 99m}Tc; Estudo de marcacao dos anticorpos monoclonais IOR-CEA-1 e IOR-EGF/R3 com {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Dias, Carla Roberta de Barros Rodrigues

2005-07-01

Nuclear Medicine is a speciality that uses radioisotopes for the diagnosis or treatment of diseases and it is considered one of the best tools among the diagnostic modalities for detection of cancer. {sup 99m}Tc is one of the main isotopes for labelling antibodies and in Nuclear Medicine in general, due to its adequate physical properties, availability and low cost. Labelled monoclonal antibodies have shown promising results for diagnosis and therapy of cancer and their use has brought great experimental and clinical advances in the field of oncology. The main clinical applications of immunoscintigraphy with monoclonal antibodies are staging and evaluation of tumoral reappearance. The antibodies employed in this work were: OIR-CEA-1, a murine monoclonal antibody that acts directly against CEA expressed in several neoplasia in particular those from the gastrointestinal tract (colorectal cancer) and IOR-EGF/R3, a murine monoclonal antibody that binds to the external domain of EGF-R and it has been used in the diagnosis of tumors of epithelial origin. The objectives of this work were the development and optimization of the reduction and purification processes, the radiolabelling techniques and quality control procedures (radiochemical, immunoreactivity and cystein challenge) and imaging studies of monoclonal antibodies OIR-CEA-1 and IOR-EGF/R3, using the simple, fast and efficient method of direct labelling of the antibody with {sup 99m}Tc. The final results was the definition of the best conditions for the preparation of lyophilized reactive kits of OIR-CEA-1 and IOR- EGF/R3 for an efficient diagnostic application in Nuclear Medicine. The most adequate conditions for the labelling of the antibodies were: 1.0 mg Ab, 29 {mu}L MDP, 3.0 {mu}g Sn{sup 2+}, 1 mL of {sup 99m}Tc and 30 min. reaction time. With these conditions the labelling yield was always higher than 95% and the maximum activity of {sup 99m}Tc was about 2220 MBq (60 mCi). The evidences of the efficiency and

Gerbes over posets and twisted C*-dynamical systems

OpenAIRE

Vasselli, Ezio

2017-01-01

A base $\\Delta$ generating the topology of a space $M$ becomes a partially ordered set (poset), when ordered under inclusion of open subsets. Given a precosheaf over $\\Delta$ of fixed-point spaces (typically C*-algebras) under the action of a group $G$, in general one cannot find a precosheaf of $G$-spaces having it as fixed-point precosheaf. Rather one gets a gerbe over $\\Delta$, that is, a "twisted precosheaf" whose twisting is encoded by a cocycle with coefficients in a suitable 2-group. W...

Preparing a Minimum Information about a Flow Cytometry Experiment (MIFlowCyt) compliant manuscript using the International Society for Advancement of Cytometry (ISAC) FCS file repository (FlowRepository.org).

Science.gov (United States)

Spidlen, Josef; Breuer, Karin; Brinkman, Ryan

2012-07-01

FlowRepository.org is a Web-based flow cytometry data repository provided by the International Society for Advancement of Cytometry (ISAC). It supports storage, annotation, analysis, and sharing of flow cytometry datasets. A fundamental tenet of scientific research is that published results should be open to independent validation and refutation. With FlowRepository, researchers can annotate their datasets in compliance with the Minimum Information about a Flow Cytometry Experiment (MIFlowCyt) standard, thus greatly facilitating third-party interpretation of their data. In this unit, we will mainly focus on the deposition, sharing, and annotation of flow cytometry data.

Factorising the 3D topologically twisted index

Science.gov (United States)

Cabo-Bizet, Alejandro

2017-04-01

We explore the path integration — upon the contour of hermitian (non-auxliary) field configurations — of topologically twisted N=2 Chern-Simons-matter theory (TTCSM) on {S}_2 times a segment. In this way, we obtain the formula for the 3D topologically twisted index, first as a convolution of TTCSM on {S}_2 times halves of {S}_1 , second as TTCSM on {S}_2 times {S}_1 — with a puncture, — and third as TTCSM on {S}_2× {S}_1 . In contradistinction to the first two cases, in the third case, the vector multiplet auxiliary field D is constrained to be anti-hermitian.

Obstructions for twist star products

Science.gov (United States)

Bieliavsky, Pierre; Esposito, Chiara; Waldmann, Stefan; Weber, Thomas

2018-05-01

In this short note, we point out that not every star product is induced by a Drinfel'd twist by showing that not every Poisson structure is induced by a classical r-matrix. Examples include the higher genus symplectic Pretzel surfaces and the symplectic sphere S^2.

Comparative study of {sup 99}Mo/{sup 99m}Tc generators at base of synthesized gels starting from activation and fission {sup 99}Mo; Estudio comparativo de generadores {sup 99}Mo/{sup 99m}Tc a base de geles sintetizados a partir de {sup 99}Mo de activacion y de fision

Energy Technology Data Exchange (ETDEWEB)

Lopez M, I Z [UAEM, Paseo Colon esq. Paseo Tollocan, 50120 Toluca, Estado de Mexico (Mexico); Monroy G, F; Rivero G, T; Rojas N, P [ININ, Carretera Mexico -Toluca S/N, 52045 La Marquesa Ocoyoacac, Estado de Mexico (Mexico)

2007-07-01

The {sup 99m}Tc is used for diagnostic and therapy. It is produced starting from {sup 99}Mo, absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of {sup 99}Mo with high specific activities of {sup 99}Mo, obtained from the {sup 235}U fission. Given these conditions and limitations, new preparation procedures of {sup 99}Mo/{sup 99m}Tc generators, its have been developed, using zirconium molybdates gels that incorporates until 30% of {sup 99}Mo, conserve similar characteristics of quality and purity that the traditional generator. The radiochemical characteristics of the {sup 99m}Tc elution, depend strongly on the gel preparation conditions. In particular, the present work has by object to determine the influence of the {sup 99}Mo used type, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the {sup 99}Mo/{sup 99m}Tc generators quality. When diminishing the flow of agitation air the efficiency it increases and in the radionuclide purity of the eluates and when using {sup 99}Mo from fission for the gels production it increases in an important way the elutriation efficiency, the radiochemical and radionuclide purity of the {sup 99m}Tc eluates. (Author)

Optics of twisted nematic and supertwisted nematic liquid-crystal displays

Science.gov (United States)

Leenhouts, F.; Schadt, M.

1986-11-01

For the first time calculations of the off-state transmission of twisted nematic liquid-crystal displays (LCD's) are presented which exhibit twist angles greater than the conventional 90 °. The transmission has been calculated using a treatment introduced by Priestley. In addition, the CIE (Commission Internationale d'Eclairage) color coordinates were evaluated which, together with the brightness, determine the optical appearance of an LCD. The finite efficiency of the polarizers was taken into account. The results are compared with those obtained for conventional 90 ° twisted nematic LCD's. From the calculations follow the conditions required to obtain optimal contrast and steep electro-optical characteristics in 180 ° supertwisted LCD's designed for high information content applications.

NTS1-R-targeted diagnostic imaging of malignant tumors with 99mTc labeled neurotensin analogues

International Nuclear Information System (INIS)

Nikolopoulou, A.; Nock, B.; Maina, T.; Galanis, A.; Cordopatis, P.

2004-01-01

Full text: Recent studies, based on receptor radio autoradiography methods in human biopsy specimens, have demonstrated the expression of neurotensin receptors of subtype 1 (NTSI-R) at a high density in primary human cancers, such as in ductal exocrine pancreatic carcinoma, Ewing's sarcoma and meningioma. This finding provides the molecular basis for the scintigraphic detection of NTS1-R-positive tumors in patients using radiolabeled NT analogues in combination with SPECT. We synthesized two novel NT analogues based on the NT (8-13) peptide sequence - essential for interaction with the NTS1-R - and modified at the N-terminal by a covalently attached open chain tetraamine chelator for stable binding of the radionuclide. In this work, a comparative study of the new compounds in cells and animal models is presented and their suitability in the NTS1-R- targeted diagnostic imaging of malignant tumors is discussed. In particular, the tetra-amine functional analogues NT1: [N4- (a) Ala0, Dab9] NT (8-13) and NT2: [N4- (a) Ala0, Dab9, Tle12] NT (8-13) were synthesized by SPPS techniques applying Fmoc/Boc protection strategies. The ES-MS spectra of the chromatographically purified products were consistent with the expected formulae. Incorporation of the radiometal (99mTc) by the open chain tetraamine framework proceeded different at room temperature in alkaline aqueous medium using SnCl2 as reducing agent in the presence of citrate. Under the above mild conditions labelling was nearly quantitative leading to single radiopeptide species of high specific activity. During competition binding assays in human colon adenocarcinoma WiDr cell membranes, using [125I-Tyr3] NT as the radioligand, both peptide conjugates demonstrated high affinity binding to the NTS1-R with IC50s 30 and 80 pM, respectively (IC50 for native NT= 0.20 nM). Both radiopeptides showed a rapid and NTS1-R-mediated migration into the intracellular compartment of the same cells reaching a 95% internalization

miR-151-3p Targets TWIST1 to Repress Migration of Human Breast Cancer Cells.

Directory of Open Access Journals (Sweden)

Ting-Chih Yeh

Full Text Available TWIST1 is a highly conserved basic helix-loop-helix transcription factor that contributes to cancer metastasis by promoting an epithelial-mesenchymal transition and repressing E-cadherin gene expression in breast cancer. In this study, we explored the potential role of miR-151 in TWIST1 expression and cancer properties in human breast cancer cells. We found that the human TWIST1 3'UTR contains a potential binging site for miR-151-3p at the putative target sequence 5'-CAGUCUAG-3'. Using a TWIST1-3'UTR luciferase reporter assay, we demonstrated that the target sequence within the TWIST1 3'UTR is required for miR-151-3p regulation of TWIST1 expression. Moreover, we found that ectopic expression of miR-151-3p by infection with adenoviruses expressing miR-151 significantly decreased TWIST1 expression, migration and invasion, but did not affect cell growth and tumorsphere formation of human breast cancer cells. In addition, overexpression of the protein coding region without the 3'UTR of TWIST1 reversed the repression of cell migration by miR-151-3p. Furthermore, knockdown of miR-151-3p increased TWIST1 expression, reduced E-cadherin expression, and enhanced cell migration. In conclusion, these results suggest that miR-151-3p directly regulates TWIST1 expression by targeting the TWIST1 3'UTR and thus repressing the migration and invasion of human breast cancer cells by enhancing E-cadherin expression. Our findings add to accumulating evidence that microRNAs are involved in breast cancer progression by modulating TWIST1 expression.

PERFORMANCE CHARACTERISTICS OF PARABOLIC SOLAR COLLECTOR WATER HEATER SYSTEM FITTED WITH NAIL TWISTED TAPES ABSORBER

Directory of Open Access Journals (Sweden)

K. SYED JAFAR

2017-03-01

Full Text Available In this paper, the experimental heat transfer, friction loss and thermal performance data for water flowing through the absorber tube fitted with two different twisted tape configurations in parabolic trough collector (PTC are presented. In the present work, a relative experimental study is carried out to investigate the performance of a PTC influenced by heat transfer through fluidabsorber wall mixing mechanism. The major findings of this experiment show that heat transport enhancement in the nail twisted tape collector perform significantly better than plain twisted tapes and also show that the smallest twisted tape ratio enhances the system performance remarkably maximizing the collector efficiency. The results suggest that the twisted tape and nail twisted tape would be a better option for high thermal energy collection in laminar region of the PTC system.

Spinning geometry = Twisted geometry

International Nuclear Information System (INIS)

Freidel, Laurent; Ziprick, Jonathan

2014-01-01

It is well known that the SU(2)-gauge invariant phase space of loop gravity can be represented in terms of twisted geometries. These are piecewise-linear-flat geometries obtained by gluing together polyhedra, but the resulting geometries are not continuous across the faces. Here we show that this phase space can also be represented by continuous, piecewise-flat three-geometries called spinning geometries. These are composed of metric-flat three-cells glued together consistently. The geometry of each cell and the manner in which they are glued is compatible with the choice of fluxes and holonomies. We first remark that the fluxes provide each edge with an angular momentum. By studying the piecewise-flat geometries which minimize edge lengths, we show that these angular momenta can be literally interpreted as the spin of the edges: the geometries of all edges are necessarily helices. We also show that the compatibility of the gluing maps with the holonomy data results in the same conclusion. This shows that a spinning geometry represents a way to glue together the three-cells of a twisted geometry to form a continuous geometry which represents a point in the loop gravity phase space. (paper)

A New Twisting Somersault: 513XD

Science.gov (United States)

Tong, William; Dullin, Holger R.

2017-12-01

We present the mathematical framework of an athlete modelled as a system of coupled rigid bodies to simulate platform and springboard diving. Euler's equations of motion are generalised to non-rigid bodies and are then used to innovate a new dive sequence that in principle can be performed by real-world athletes. We begin by assuming that shape changes are instantaneous so that the equations of motion simplify enough to be solved analytically, and then use this insight to present a new dive (513XD) consisting of 1.5 somersaults and five twists using realistic shape changes. Finally, we demonstrate the phenomenon of converting pure somersaulting motion into pure twisting motion by using a sequence of impulsive shape changes, which may have applications in other fields such as space aeronautics.

Hover Testing of the NASA/Army/MIT Active Twist Rotor Prototype Blade

Science.gov (United States)

Wilbur, Matthew L.; Yeager, William T., Jr.; Wilkie, W. Keats; Cesnik, Carlos E. S.; Shin, Sangloon

2000-01-01

Helicopter rotor individual blade control promises to provide a mechanism for increased rotor performance and reduced rotorcraft vibrations and noise. Active material methods, such as piezoelectrically actuated trailing-edge flaps and strain-induced rotor blade twisting, provide a means of accomplishing individual blade control without the need for hydraulic power in the rotating system. Recent studies have indicated that controlled strain induced blade twisting can be attained using piezoelectric active fiber composite technology. In order to validate these findings experimentally, a cooperative effort between NASA Langley Research Center, the Army Research Laboratory, and the MIT Active Materials and Structures Laboratory has been developed. As a result of this collaboration an aeroelastically-scaled active-twist model rotor blade has been designed and fabricated for testing in the heavy gas environment of the Langley Transonic Dynamics Tunnel (TDT). The results of hover tests of the active-twist prototype blade are presented in this paper. Comparisons with applicable analytical predictions of active-twist frequency response in hovering flight are also presented.

Developing and Testing a Scale of Moral Thinking and Communication (MTC) Functioning: A Preliminary Study and Its Implications for Moral Development and Education

Science.gov (United States)

Lee, Chi-Ming Angela; Thoma, Stephen J.

2018-01-01

The purpose of this study was to develop and test a scale assessing students' moral thinking and communication (MTC) functioning as well as to explore the implications for moral development and education. The rationale of MTC functioning, including interaction of four independent competencies: moral awareness, moral judgement, moral discourse, and…

From starproducts to Drinfeld-twists. Present and future applications

International Nuclear Information System (INIS)

Koch, Florian

2008-01-01

Physics comes up with models that invoke noncommutative structures in configuration space. Such structures are dual to the deformed coalgebra sector of a represented symmetry algebra. In the mean time such deformations are performed in terms of the symmetry algebra itself via twists or quasitriangular structures. One might thus find oneself in the bad situation that the symmetry algebra is not large enough to provide the required twist that dually matches the noncommutative structure found. It thus has to remain in the unpleasant state of being without any notion of symmetry. We show how starproducts can be pushed to twists by introducing a larger algebra that accommodates any finite dimensional representation of a Lie-algebra. This new algebra is similar to a Heisenberg-algebra but in contrast to the latter can be enhanced to a Hopf-algebra. Some Examples are given. (author)

Anomalous phase shift in a twisted quantum loop

International Nuclear Information System (INIS)

Taira, Hisao; Shima, Hiroyuki

2010-01-01

The coherent motion of electrons in a twisted quantum ring is considered to explore the effect of torsion inherent to the ring. Internal torsion of the ring composed of helical atomic configuration yields a non-trivial quantum phase shift in the electrons' eigenstates. This torsion-induced phase shift causes novel kinds of persistent current flow and an Aharonov-Bohm-like conductance oscillation. The two phenomena can occur even when no magnetic flux penetrates inside the twisted ring, thus being in complete contrast with the counterparts observed in untwisted rings.

The geometrical origin of the strain-twist coupling in double helices

DEFF Research Database (Denmark)

Olsen, Kasper; Bohr, Jakob

2011-01-01

A simple geometrical explanation for the counterintuitive phenomenon when twist leads to extension in double helices is presented. The coupling between strain and twist is investigated using a tubular description. It is shown that the relation between strain and rotation is universal and depends...

Waveguides with asymptotically diverging twisting

Czech Academy of Sciences Publication Activity Database

Krejčiřík, David

2015-01-01

Roč. 46, AUG (2015), s. 7-10 ISSN 0893-9659 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : quantum waveguide * exploding twisting * Quasi-bounded * Quasi-cylindrical * discrete spectrum Subject RIV: BE - Theoretical Physics Impact factor: 1.659, year: 2015

Demonstration of an elastically coupled twist control concept for tilt rotor blade application

Science.gov (United States)

Lake, R. C.; Nixon, M. W.; Wilbur, M. L.; Singleton, J. D.; Mirick, P. H.

1994-01-01

The purpose of this Note is to present results from an analytic/experimental study that investigated the potential for passively changing blade twist through the use of extension-twist coupling. A set of composite model rotor blades was manufactured from existing blade molds for a low-twist metal helicopter rotor blade, with a view toward establishing a preliminary proof concept for extension-twist-coupled rotor blades. Data were obtained in hover for both a ballasted and unballasted blade configuration in sea-level atmospheric conditions. Test data were compared with results obtained from a geometrically nonlinear analysis of a detailed finite element model of the rotor blade developed in MSC/NASTRAN.

Particle image velocimetry measurements of 2-dimensional velocity field around twisted tape

Energy Technology Data Exchange (ETDEWEB)

Song, Min Seop; Park, So Hyun; Kim, Eung Soo, E-mail: kes7741@snu.ac.kr

2016-11-01

Highlights: • Measurements of the flow field in a pipe with twisted tape were conducted by particle image velocimetry (PIV). • A novel matching index of refraction technique utilizing 3D printing and oil mixture was adopted to make the test section transparent. • Undistorted particle images were clearly captured in the presence of twisted tape. • 2D flow field in the pipe with twisted tape revealed the characteristic two-peak velocity profile. - Abstract: Twisted tape is a passive component used to enhance heat exchange in various devices. It induces swirl flow that increases the mixing of fluid. Thus, ITER selected the twisted tape as one of the candidates for turbulence promoting in the divertor cooling. Previous study was mainly focused on the thermohydraulic performance of the twisted tape. As detailed data on the velocity field around the twisted tape was insufficient, flow visualization study was performed to provide fundamental data on velocity field. To visualize the flow in a complex structure, novel matching index of refraction technique was used with 3-D printing and mixture of anise and mineral oil. This technique enables the camera to capture undistorted particle image for velocity field measurement. Velocity fields at Reynolds number 1370–9591 for 3 different measurement plane were obtained through particle image velocimetry. The 2-dimensional averaged velocity field data were obtained from 177 pair of instantaneous velocity fields. It reveals the characteristic two-peak flow motion in axial direction. In addition, the normalized velocity profiles were converged with increase of Reynolds numbers. Finally, the uncertainty of the result data was analyzed.

Epigenetic inactivation of TWIST2 in acute lymphoblastic leukemia modulates proliferation, cell survival and chemosensitivity

Science.gov (United States)

Thathia, Shabnam H.; Ferguson, Stuart; Gautrey, Hannah E.; van Otterdijk, Sanne D.; Hili, Michela; Rand, Vikki; Moorman, Anthony V.; Meyer, Stefan; Brown, Robert; Strathdee, Gordon

2012-01-01

Background Altered regulation of many transcription factors has been shown to be important in the development of leukemia. TWIST2 modulates the activity of a number of important transcription factors and is known to be a regulator of hematopoietic differentiation. Here, we investigated the significance of epigenetic regulation of TWIST2 in the control of cell growth and survival and in response to cytotoxic agents in acute lymphoblastic leukemia. Design and Methods TWIST2 promoter methylation status was assessed quantitatively, by combined bisulfite and restriction analysis (COBRA) and pyrosequencing assays, in multiple types of leukemia and TWIST2 expression was determined by quantitative reverse transcriptase polymerase chain reaction analysis. The functional role of TWIST2 in cell proliferation, survival and response to chemotherapy was assessed in transient and stable expression systems. Results We found that TWIST2 was inactivated in more than 50% of cases of childhood and adult acute lymphoblastic leukemia through promoter hypermethylation and that this epigenetic regulation was especially prevalent in RUNX1-ETV6-driven cases. Re-expression of TWIST2 in cell lines resulted in a dramatic reduction in cell growth and induction of apoptosis in the Reh cell line. Furthermore, re-expression of TWIST2 resulted in increased sensitivity to the chemotherapeutic agents etoposide, daunorubicin and dexamethasone and TWIST2 hypermethylation was almost invariably found in relapsed adult acute lymphoblastic leukemia (91% of samples hypermethylated). Conclusions This study suggests a dual role for epigenetic inactivation of TWIST2 in acute lymphoblastic leukemia, initially through altering cell growth and survival properties and subsequently by increasing resistance to chemotherapy. PMID:22058208

Modal Properties and Stability of Bend-Twist Coupled Wind Turbine Blades

DEFF Research Database (Denmark)

Stäblein, Alexander R.; Hansen, Morten Hartvig; Verelst, David Robert

2017-01-01

a steady-state equilibrium using the aero-servo-elastic tool HAWCStab2 which has been extended by a beam element that allows for fully coupled cross-sectional properties. Bend-twist coupling is introduced in the cross-sectional stiffness matrix by means of coupling coefficients that introduce twist...

Study of Implosion of Twisted Nested Arrays at the Angara-5-1 Facility

Science.gov (United States)

Mitrofanov, K. N.; Zukakishvili, G. G.; Aleksandrov, V. V.; Grabovski, E. V.; Frolov, I. N.; Gribov, A. N.

2018-01-01

Results are presented from experimental studies of the implosion of twisted nested arrays in which the wires of the outer and inner arrays are twisted about the array axis in opposite directions (clockwise and counterclockwise). Experiments with twisted arrays were carried out at the Angara-5-1 facility at currents of up to 4 MA. The currents through the arrays were switched either simultaneously or the current pulse through the outer array was delayed by 10-15 ns with the help of an anode spark gap. It is shown that, in such arrays, the currents flow along the inclined wires and, accordingly, there are both the azimuthal and axial components of the discharge current. The process of plasma implosion in twisted arrays depends substantially on the value of the axial (longitudinal) magnetic field generated inside the array by the azimuthal currents. Two-dimensional simulations of the magnetic field in twisted nested arrays were performed in the ( r, z) geometry with allowance for the skin effect in the discharge electrodes. It is shown that, depending on the geometry of the discharge electrodes, different configurations of the magnetic field can be implemented inside twisted nested arrays. The calculated magnetic configurations are compared with the results of measurements of the magnetic field inside such arrays. It is shown that the configuration of the axial magnetic field inside a twisted nested array depends substantially on the distribution of the azimuthal currents between the inner and outer arrays.

Realizations of κ-Minkowski space, Drinfeld twists, and related symmetry algebras

Energy Technology Data Exchange (ETDEWEB)

Juric, Tajron; Meljanac, Stjepan; Pikutic, Danijel [Ruder Boskovic Institute, Theoretical Physics Division, Zagreb (Croatia)

2015-11-15

Realizations of κ-Minkowski space linear in momenta are studied for time-, space- and light-like deformations. We construct and classify all such linear realizations and express them in terms of the gl(n) generators. There are three one-parameter families of linear realizations for timelike and space-like deformations, while for light-like deformations, there are only four linear realizations. The relation between a deformed Heisenberg algebra, the star product, the coproduct of momenta, and the twist operator is presented. It is proved that for each linear realization there exists a Drinfeld twist satisfying normalization and cocycle conditions. κ-Deformed igl(n)-Hopf algebras are presented for all cases. The κ-Poincare-Weyl and κ-Poincare-Hopf algebras are discussed. The left-right dual κ-Minkowski algebra is constructed from the transposed twists. The corresponding realizations are nonlinear. All Drinfeld twists related to κ-Minkowski space are obtained from our construction. Finally, some physical applications are discussed. (orig.)

Realizations of κ-Minkowski space, Drinfeld twists, and related symmetry algebras

International Nuclear Information System (INIS)

Juric, Tajron; Meljanac, Stjepan; Pikutic, Danijel

2015-01-01

Realizations of κ-Minkowski space linear in momenta are studied for time-, space- and light-like deformations. We construct and classify all such linear realizations and express them in terms of the gl(n) generators. There are three one-parameter families of linear realizations for timelike and space-like deformations, while for light-like deformations, there are only four linear realizations. The relation between a deformed Heisenberg algebra, the star product, the coproduct of momenta, and the twist operator is presented. It is proved that for each linear realization there exists a Drinfeld twist satisfying normalization and cocycle conditions. κ-Deformed igl(n)-Hopf algebras are presented for all cases. The κ-Poincare-Weyl and κ-Poincare-Hopf algebras are discussed. The left-right dual κ-Minkowski algebra is constructed from the transposed twists. The corresponding realizations are nonlinear. All Drinfeld twists related to κ-Minkowski space are obtained from our construction. Finally, some physical applications are discussed. (orig.)

Automatic O(a) improvement for twisted mass QCD in the presence of spontaneous symmetry breaking

International Nuclear Information System (INIS)

Aoki, Sinya; Baer, Oliver

2006-01-01

In this paper we present a proof for automatic O(a) improvement in twisted mass lattice QCD at maximal twist, which uses only the symmetries of the leading part in the Symanzik effective action. In the process of the proof we clarify that the twist angle is dynamically determined by vacuum expectation values in the Symanzik theory. For maximal twist according to this definition, we show that scaling violations of all quantities which have nonzero values in the continuum limit are even in a. In addition, using Wilson chiral perturbation theory, we investigate this definition for maximal twist and compare it to other definitions which were already employed in actual simulations

Highly multiparametric analysis by mass cytometry.

Science.gov (United States)

Ornatsky, Olga; Bandura, Dmitry; Baranov, Vladimir; Nitz, Mark; Winnik, Mitchell A; Tanner, Scott

2010-09-30

This review paper describes a new technology, mass cytometry, that addresses applications typically run by flow cytometer analyzers, but extends the capability to highly multiparametric analysis. The detection technology is based on atomic mass spectrometry. It offers quantitation, specificity and dynamic range of mass spectrometry in a format that is familiar to flow cytometry practitioners. The mass cytometer does not require compensation, allowing the application of statistical techniques; this has been impossible given the constraints of fluorescence noise with traditional cytometry instruments. Instead of "colors" the mass cytometer "reads" the stable isotope tags attached to antibodies using metal-chelating labeling reagents. Because there are many available stable isotopes, and the mass spectrometer provides exquisite resolution between detection channels, many parameters can be measured as easily as one. For example, in a single tube the technique allows for the ready detection and characterization of the major cell subsets in blood or bone marrow. Here we describe mass cytometric immunophenotyping of human leukemia cell lines and leukemia patient samples, differential cell analysis of normal peripheral and umbilical cord blood; intracellular protein identification and metal-encoded bead arrays. Copyright © 2010 Elsevier B.V. All rights reserved.

Confirmation of hydrazone formation in HYNIC-peptide conjugate preparation, and its hydrolysis during labeling with {sup 99m}Tc

Energy Technology Data Exchange (ETDEWEB)

Gandomkar, M. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of)]. E-mail: msgandomkar@yahoo.com; Najafi, R. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Shafiei, M. [Radioisotope Division, Nuclear Research Center, Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Ebrahimi, S.E.S. [Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2007-07-15

Because of its monodenticity, 6-hydrazinopyridine-3-carboxylic acid (HYNIC) is of interest as a bifunctional chelator for labeling peptide with {sup 99m}Tc. Here, we confirm the formation of hydrazone in HYNIC-conjugated peptide. The preparative HPLC was used to purify the HYNIC conjugated somatostatin-based peptide and the result showed two peaks, even after two consecutive purifications. Analysis of these peaks by mass spectrometry indicated the presence of hydrazone, produced during preparation conjugate. Further, we have shown that presence of hydrazone really does not matter because under {sup 99m}Tc-labeling conditions, hydrazone is hydrolyzed back to HYNIC that then chelates {sup 99m}Tc. A HYNIC-peptide conjugate freeze-dried kit was also prepared in a mildly acidic or neutral condition with a final pH of 6-7. The kit was then labeled by {sup 99m}Tc and incubated in 100 dec. C for 10 min, and a labeling yield of >95% was obtained.

Balloon-based adjuvant radiotherapy in breast cancer: comparison between 99mTc and HDR 192Ir

Directory of Open Access Journals (Sweden)

Tarcísio Passos Ribeiro de Campos

2016-04-01

Full Text Available Abstract Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with 99mTc and balloon brachytherapy with high-dose-rate (HDR 192Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and Methods: Simulations of implants with 99mTc-filled and HDR 192Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: The 99mTc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h-1.mCi-1 and 0.190 cGyh-1.mCi-1 at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh-1.mCi-1, respectively, for the HDR 192Ir balloon. An exposure time of 24 hours was required for the 99mTc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR 192Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: Temporary 99mTc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR 192Ir balloon implantation, which is the current standard in clinical practice.

The $SU(\\infty)$ twisted gradient flow running coupling

CERN Document Server

Pérez, Margarita García; Keegan, Liam; Okawa, Masanori

2015-01-01

We measure the running of the $SU(\\infty)$ 't Hooft coupling by performing a step scaling analysis of the Twisted Eguchi-Kawai (TEK) model, the SU($N$) gauge theory on a single site lattice with twisted boundary conditions. The computation relies on the conjecture that finite volume effects for SU(N) gauge theories defined on a 4-dimensional twisted torus are controlled by an effective size parameter $\\tilde l = l \\sqrt{N}$, with $l$ the torus period. We set the scale for the running coupling in terms of $\\tilde l$ and use the gradient flow to define a renormalized 't Hooft coupling $\\lambda(\\tilde l)$. In the TEK model, this idea allows the determination of the running of the coupling through a step scaling procedure that uses the rank of the group as a size parameter. The continuum renormalized coupling constant is extracted in the zero lattice spacing limit, which in the TEK model corresponds to the large $N$ limit taken at fixed value of $\\lambda(\\tilde l)$. The coupling constant is thus expected to coinc...

Twist effects in quantum vortices and phase defects

Science.gov (United States)

Zuccher, Simone; Ricca, Renzo L.

2018-02-01

In this paper we show that twist, defined in terms of rotation of the phase associated with quantum vortices and other physical defects effectively deprived of internal structure, is a property that has observable effects in terms of induced axial flow. For this we consider quantum vortices governed by the Gross-Pitaevskii equation (GPE) and perform a number of test cases to investigate and compare the effects of twist in two different contexts: (i) when this is artificially superimposed on an initially untwisted vortex ring; (ii) when it is naturally produced on the ring by the simultaneous presence of a central straight vortex. In the first case large amplitude perturbations quickly develop, generated by the unnatural setting of the initial condition that is not an analytical solution of the GPE. In the second case much milder perturbations emerge, signature of a genuine physical process. This scenario is confirmed by other test cases performed at higher twist values. Since the second setting corresponds to essential linking, these results provide new evidence of the influence of topology on physics.

Production of $^{99}$?? and $^{99m}$Tc in the $^{100}$Mo($\\gamma, n$) Photonuclear Reaction at the Electron Accelerator - MT-25 Microtron

CERN Document Server

Sabelnikov, A V; Gustova, M V; Dmitriev, S N

2004-01-01

$^{99}$Mo was obtained in the $^{100}$Mo($\\gamma, n$) reaction at the electron accelerator - MT-25 microtron of the LNR. A foil of $^{\\rm nat}$Mo(9.6{\\%} $^{100}$Mo) and $^{100}$MoO$_{3}$ powder (100{\\%} ^{100}$Mo) were used as targets. The $^{99}$Mo radiation yield under experimental conditions amounted to 3.2 kBq/$\\mu $A$\\cdot $h$\\cdot $mg of $^{100}$Mo. The $^{99m}$Tc isolation from the target material and other radioactive impurities was realized by means of ion exchange. A possibility of use of the $^{99}$Mo/$^{99m}$Tc generator based on molybdenumcarbonyl was investigated. The radioactive impurity content in the final $^{99m}$Tc preparations did not exceed 10$^{-5}$ Bq/Bq.

Factorising the 3D topologically twisted index

Energy Technology Data Exchange (ETDEWEB)

Cabo-Bizet, Alejandro [Instituto de Astronomía y Física del Espacio (CONICET-UBA),Ciudad Universitaria, C.P. 1428, Buenos Aires (Argentina)

2017-04-20

We explore the path integration — upon the contour of hermitian (non-auxliary) field configurations — of topologically twisted N=2 Chern-Simons-matter theory (TTCSM) on S{sub 2} times a segment. In this way, we obtain the formula for the 3D topologically twisted index, first as a convolution of TTCSM on S{sub 2} times halves of S{sub 1}, second as TTCSM on S{sub 2} times S{sub 1} — with a puncture, — and third as TTCSM on S{sub 2}×S{sub 1}. In contradistinction to the first two cases, in the third case, the vector multiplet auxiliary field D is constrained to be anti-hermitian.

Leibniz algebroids, twistings and exceptional generalized geometry

Science.gov (United States)

Baraglia, D.

2012-05-01

We investigate a class of Leibniz algebroids which are invariant under diffeomorphisms and symmetries involving collections of closed forms. Under appropriate assumptions we arrive at a classification which in particular gives a construction starting from graded Lie algebras. In this case the Leibniz bracket is a derived bracket and there are higher derived brackets resulting in an L∞-structure. The algebroids can be twisted by a non-abelian cohomology class and we prove that the twisting class is described by a Maurer-Cartan equation. For compact manifolds we construct a Kuranishi moduli space of this equation which is shown to be affine algebraic. We explain how these results are related to exceptional generalized geometry.

Development, preparation and control of sup(99m)Tc or sup(113m)In labelled stannous hydroxide radiopharmaceuticals. Part of a coordinated programme on radiopharmaceuticals

International Nuclear Information System (INIS)

Alvarez Cervera, J.

1975-01-01

The preparation of different sup(99m)Tc and sup(113m)In radiopharmaceuticals using stannous chloride was investigated. Chemical and radiochemical procedures for the quality control of these preparations were studied. Toxicity and biological controls of the preparation were carried out. Procedures for the preparation and control of the following radiopharmaceuticals have been standardized by the authors; albumin macroaggregates labelled with sup(99m)Tc, sup(113m)In and other isotopes for lung scanning; albumin microspheres labelled with sup(99m)Tc for lung scanning; sup(99m)Tc or sup(113m)In-labelled stannous hydroxide colloid for liver scanning; sup(99m)Tc-stannous phytate for liver scanning; sup(99m)Tc-Sn-dextrose, a new radiopharmaceutical which has been proposed by the authors and is now used in Mexico for renal and cerebral scanning and sup(99m)Tc-Sn pyrophosphate and diphosphonate for bone scanning

On the twists of interplanetary magnetic flux ropes observed at 1 AU

OpenAIRE

Wang, Yuming; Zhuang, Bin; Hu, Qiang; Liu, Rui; Shen, Chenglong; Chi, Yutian

2016-01-01

Magnetic flux ropes (MFRs) are one kind of fundamental structures in the solar physics, and involved in various eruption phenomena. Twist, characterizing how the magnetic field lines wind around a main axis, is an intrinsic property of MFRs, closely related to the magnetic free energy and stableness. So far it is unclear how much amount of twist is carried by MFRs in the solar atmosphere and in heliosphere and what role the twist played in the eruptions of MFRs. Contrasting to the solar MFRs,...

Exclusive processes beyond leading twist: {gamma}*T {yields} {rho}T impact factor with twist three accuracy

Energy Technology Data Exchange (ETDEWEB)

Szymanowski, Lech [Soltan Institute for Nuclear Studies, Hoza 69, 00691, Warsaw (Poland); Anikin, Igor V. [Joint Institute for Nuclear Research - JINR, Joliot-Curie st., 6, Moskovskaya obl., 141980, Dubna (Russian Federation); Ivanov, Dmitry Yu [Sobolev Institute of Mathematics, Acad. Koptyug pr., 4, 630090 Novosibirsk (Russian Federation); Pire, Bernard [Centre de Physique Theorique - CPHT, UMR 7644, Ecole Polytechnique, Bat. 6, RDC, F91128 Palaiseau Cedex (France); Wallon, Samuel [Laboratoire de Physique Theorique d' Orsay - LPT, Bat. 210, Univ. Paris-Sud 11, 91405 Orsay Cedex (France)

2010-07-01

We describe a consistent approach to factorization of scattering amplitudes for exclusive processes beyond the leading twist approximation. The method is based on the Taylor expansion of the scattering amplitude in the momentum space around the dominant light-cone direction and thus naturally introduces an appropriate set of non-perturbative correlators which encode effects not only of the lowest but also of the higher Fock states of the produced particle. The reduction of original set of correlators to a set of independent ones is achieved with the help of equations of motion and invariance of the scattering amplitude under rotation on the light-cone. As a concrete application, we compute the expressions of the impact factor for the transition of virtual photon to transversally polarised {rho}-meson up to the twist 3 accuracy. (Phys.Lett.B682:413-418,2010 and Nucl.Phys.B828:1-68,2010.). (authors)

Occupational exposure to {sup 99m}Tc and {sup 131}I in a radiopharmacy room

Energy Technology Data Exchange (ETDEWEB)

Valle, Bruna P.; Cunha, Kenya Dias da; Sa, Lidia Vasconcellos de; Souza, Wanderson; Santos, Maristela; Medeiras, Geiza; Conceicao, Cirilo S. [Universidade do Estado, Nova Friburgo, RJ (Brazil). Inst. Politecnico. Dept. de Modelagem Computacional], e-mail: brunapvalle@gmail.com, e-mail: kenya@ird.gov.br, e-mail: lidia@ird.gov.br, e-mail: wander@ird.gov.br, e-mail: mstela@ird.gov.br; Abrantes, Marcio Borges de [Centro de Medicina Nuclear Guanabara, Rio de Janeiro, RJ (Brazil)], e-mail: marcioabrantes@pop.com.br

2009-07-01

Brazil has about 310 nuclear medicine services and 90% of these services use Molybdenum/Technetium generators to prepare several radiopharmaceuticals to diagnostics; about 70% use also {sup 131}I for diagnosis and therapy. These radionuclides are associated to compounds in liquid form and during the manipulation to prepare and administer the patient dose some radioactive airborne particle can be generated. As consequence the workers can be exposed to airborne particles in the respirable fraction containing {sup 99m}Tc and {sup 131}I. The aim of this study is develop a simple and rapid method to verify if the exhaust systems installed in the SMN are efficient in preventing the inhalation of radionuclides airborne particles by workers. In order to estimate the occupational exposure a nuclear medicine service was selected and aerosol samples were collected using personal air sampler with a cyclone. The samples were analyzed using a germanium detector system and the {sup 99m}Tc and {sup 131}I average concentrations were obtained as 16,6 {+-} 14,34 mBq/m{sup 3} and 0.72 {+-} 0.36 mBq/m{sup 3}, respectively. It was not observed a correlation among air concentration and total activity processed in laboratory. These results show that the worker inhales airborne particles containing {sup 99m}Tc and {sup 131}I. (author)

Development and utilization of the inorganic polymer materials for {sup 99}Mo-{sup 99m}Tc and {sup 188}W-{sup 188}Re generator based on (n, gamma) method

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Kosuke; Ishikawa, Koji; Terunuma, Hitoshi; Hasegawa, Yoshio; Tatenuma, Katsuyoshi [KAKEN Co., Mito, Ibaraki (Japan)

2003-03-01

A molybdenum (Mo) adsorbent called PZC (Poly Zirconium Compound) with high efficiency of Mo adsorption has been developed in order to generate {sup 99m}Tc from {sup 99}Mo produced from natural Mo by (n, gamma) method. The {sup 99m}Tc generator using PZC has cleared mostly the technical subjects. By the results of many experiments, cold and hot test with {sup 99}Mo activity from low level (10{sup 5} Bq) to high level (10{sup 10} Bq), it has been confirmed that the PZC method can be practically applied for the (n, gamma) {sup 99}Mo-{sup 99m}Tc generator. From the reasons that PZC has the ability and many merits such as high adsorption capacity (>250 mg-Mo/g-PZC) of Mo, high elution yield (av. 80%) of {sup 99m}Tc, the low breakthrough (<0.05 kBq-{sup 99m}Mo/MBq-{sup 99m}Tc) of {sup 99}Mo and others, the current (n, fission) {sup 99m}Tc generator utilizing {sup 99}Mo produced from enriched uranium will be taken the place by PZC method. In this paper, the practicability of PZC and a newly developed functional material PTC(Poly Titanium Compound) as the (n, gamma) {sup 99}Mo-{sup 99m}Tc generator, and an ability of PZC as the {sup 188}W-{sup 188}Re generator will be shown. (author)

Inner Surface Chirality of Single-Handed Twisted Carbonaceous Tubular Nanoribbons.

Science.gov (United States)

Liu, Dan; Li, Baozong; Guo, Yongmin; Li, Yi; Yang, Yonggang

2015-11-01

Single-handed twisted 4,4'-biphenylene-bridged polybissilsesquioxane tubular nanoribbons and single-layered nanoribbons were prepared by tuning the water/ethanol volume ratio in the reaction mixture at pH = 11.6 through a supramolecular templating approach. The single-layered nanoribbons were formed by shrinking tubular nanoribbons after the removal of the templates. In addition, solvent-induced handedness inversion was achieved. The handedness of the polybissilsesquioxanes could be controlled by changing the ethanol/water volume ratio in the reaction mixture. After carbonization at 900 °C for 4.0 h and removal of silica, single-handed twisted carbonaceous tubular nanoribbons and single-layered nanoribbons with micropores in the walls were obtained. X-ray diffraction and Raman spectroscopy analyses indicated that the carbon is predominantly amorphous. The circular dichroism spectra show that the twisted tubular nanoribbons exhibit optical activity, while the twisted single-layered nanoribbons do not. The results shown here indicate that chirality is transferred from the organic self-assemblies to the inner surfaces of the 4,4'-biphenylene-bridged polybissilsesquioxane tubular nanoribbons and subsequently to those of the carbonaceous tubular nanoribbons. © 2015 Wiley Periodicals, Inc.

Osserman and conformally Osserman manifolds with warped and twisted product structure

OpenAIRE

Brozos-Vazquez, M.; Garcia-Rio, E.; Vazquez-Lorenzo, R.

2008-01-01

We characterize Osserman and conformally Osserman Riemannian manifolds with the local structure of a warped product. By means of this approach we analyze the twisted product structure and obtain, as a consequence, that the only Osserman manifolds which can be written as a twisted product are those of constant curvature.

An improved hazard rate twisting approach for the statistic of the sum of subexponential variates

KAUST Repository

Rached, Nadhir B.; Kammoun, Abla; Alouini, Mohamed-Slim; Tempone, Raul

2015-01-01

In this letter, we present an improved hazard rate twisting technique for the estimation of the probability that a sum of independent but not necessarily identically distributed subexponential Random Variables (RVs) exceeds a given threshold. Instead of twisting all the components in the summation, we propose to twist only the RVs which have the biggest impact on the right-tail of the sum distribution and keep the other RVs unchanged. A minmax approach is performed to determine the optimal twisting parameter which leads to an asymptotic optimality criterion. Moreover, we show through some selected simulation results that our proposed approach results in a variance reduction compared to the technique where all the components are twisted.

The {sup 99m}Tc generator using poly zirconium chloride (PZC)

Energy Technology Data Exchange (ETDEWEB)

Wan Awang, Wan Anuar; Dahalan, Rehir; Kasim, Shaaban [Medical Technology Div., Malaysian Inst. for Nuclear Technology Research (MINT), Selangor (Malaysia)

1998-10-01

The {sup 99m}Tc generator system has been prepared using poly zirconium chloride (PZC) to replace alumina (Al{sub 2}O{sub 3}) as a adsorbent. The Mo-98 (MoO{sub 3}) was irradiated using our 1 MW TRIGA MARK II research reactor. The amount of Mo-99 adsorbed to the PZC has been studied and the yield from the elution was about 20%. (author)

Effect of Magnetic Twist on Nonlinear Transverse Kink Oscillations of Line-tied Magnetic Flux Tubes

Science.gov (United States)

Terradas, J.; Magyar, N.; Van Doorsselaere, T.

2018-01-01

Magnetic twist is thought to play an important role in many structures of the solar atmosphere. One of the effects of twist is to modify the properties of the eigenmodes of magnetic tubes. In the linear regime standing kink solutions are characterized by a change in polarization of the transverse displacement along the twisted tube. In the nonlinear regime, magnetic twist affects the development of shear instabilities that appear at the tube boundary when it is oscillating laterally. These Kelvin–Helmholtz instabilities (KHI) are produced either by the jump in the azimuthal component of the velocity at the edge of the sharp boundary between the internal and external part of the tube or by the continuous small length scales produced by phase mixing when there is a smooth inhomogeneous layer. In this work the effect of twist is consistently investigated by solving the time-dependent problem including the process of energy transfer to the inhomogeneous layer. It is found that twist always delays the appearance of the shear instability, but for tubes with thin inhomogeneous layers the effect is relatively small for moderate values of twist. On the contrary, for tubes with thick layers, the effect of twist is much stronger. This can have some important implications regarding observations of transverse kink modes and the KHI itself.

The Use of Sodium Hypochlorite Solution for (n,γ99Mo/99mTc Generator Based on Zirconium-Based Material (ZBM

Directory of Open Access Journals (Sweden)

I. Saptiama

2015-08-01

Full Text Available The many problems in preparing fission product 99Mo led into this work to develop 99Mo/99mTc generator using neutron-irradiated natural MoO3 targets and, more specifically, to develop a zirconium-based material (ZBM for chromatography columns that have an adsorption capacity of more than 100 mg Mo/g ZBM. This paper reports our recent experiments in the use of sodium hypochlorite solution of various concentrations to improve the yield of 99mTc in performance of (n,γ99Mo/99mTc generators based on the ZBM. The synthesized ZBM was coated with tetraethyl orthosilicate for improving the hardness of the material. The adsorption of [99Mo]molybdate into ZBM was carried out by reacting ZBM into [99Mo]molybdate solution at 90°C to form ZBM-[99Mo] molybdate. ZBM-[99Mo]molybdate was then packed into generator column, then eluted with 10 × 1 mL of saline followed by 1 × 5 mL of NaOCl solution. The NaOCl solution concentrations used were 0.5%; 1%; 3%; and 5% for each column, respectively. This study resulted in a ZBM which has a 99Mo adsorption capacity of 167.5 ± 3.4 mgMo/g ZBM, as well as in a yield eluate of 99mTc of up to 70%, and the find that the optimum NaOCl concentration was 3%. The use of sodium hypochlorite solution affected 99Mo breakthrough. The higher sodium hypochlorite concentration used, the more 99Mo breaktrough exist on 99mTc eluate.

Flow Cytometry Technician | Center for Cancer Research

Science.gov (United States)

PROGRAM DESCRIPTION The Basic Science Program (BSP) pursues independent, multidisciplinary research in basic and applied molecular biology, immunology, retrovirology, cancer biology, and human genetics. Research efforts and support are an integral part of the Center for Cancer Research (CCR) at the Frederick National Laboratory for Cancer Research (FNLCR). KEY ROLES/RESPONSIBILITIES The Flow Cytometry Core (Flow Core) of the Cancer and Inflammation Program (CIP) is a service core which supports the research efforts of the CCR by providing expertise in the field of flow cytometry (using analyzers and sorters) with the goal of gaining a more thorough understanding of the biology of cancer and cancer cells. The Flow Core provides service to 12-15 CIP laboratories and more than 22 non-CIP laboratories. Flow core staff provide technical advice on the experimental design of applications, which include immunological phenotyping, cell function assays, and cell cycle analysis. Work is performed per customer requirements, and no independent research is involved. The Flow Cytometry Technician will be responsible for: Monitor performance of and maintain high dimensional flow cytometer analyzers and cell sorters Operate high dimensional flow cytometer analyzers and cell sorters Monitoring lab supply levels and order lab supplies, perform various record keeping responsibilities Assist in the training of scientific end users on the use of flow cytometry in their research, as well as how to operate and troubleshoot the bench-top analyzer instruments Experience with sterile technique and tissue culture

Influence of antiseptic on the impurities in the preparation of dimercaptosuccinic labelled with {sup 99m}Tc; Influence des antiseptiques sur la presence d'impuretes dans la preparation de l'acide dimercaptosuccinique marque au 99mTc

Energy Technology Data Exchange (ETDEWEB)

Metaye, T.; Rosenberg, T.; Perdrisot, R. [CHU de Poitiers, Service de medecine nucleaire et biophysique, 86 (France)

2010-07-01

Purpose: antiseptic solutions are used to disinfect the rubber stoppers on the bottles of radiopharmaceutical. Small amounts of these solutions can pass into the bottle when the cap is pricked to inject the {sup 99m}Tc. After finding in a patient a suboptimal labelling using biseptin, we studied the effect of various antiseptics on the presence of impurities in the preparation of the dimercaptosuccinic acid labelled with {sup 99m}Tc ({sup 99m}Tc-D.M.S.A.). Conclusions: We recommend using 70% isopropanol or modified alcohol Cooper instead of biseptin to disinfect the D.M.S.A. bottles caps. (N.C.)

Study to modify the elution system in a sup(99m)Tc generator

International Nuclear Information System (INIS)

Delgado S, Baldomero.

1979-01-01

The sup(99m)Tc generator is a system that allows us to obtain sup(99m)Tc through the radioactive desintegration of 99 Mo, a radionuclide absorbed in an alumine chromatographic column, the sup(99m)Tc extraction is accomplished by elution and the 99 Mo remains at the column. In this work we try to modify the elution procedure of the generator. At present after eluating the generator, it must be dried with air, in order to support the column in an oxidant atmosphere to avoid the reduction of the technetiate. This reduction causes a low yield of elution, since the reduced species of the technetium can not be eluated. The drying of the column with air complicates a little the elution procedure, and we look to simplify it, the employed methods to resolve the problem were: a) adding an oxidant agent to the elution saline solution, b) adsorbing an oxidant in the alumina chromatographic column, after that the 99 Mo was settled. In the case a) the used oxidant agents were KMnO 4 , K 2 Cr 2 O 7 , NaNo 2 , etc. At concentration rates of 10 -7 M the obtained yields in high activity generators were of the 25-30%. In the case b) variable amounts of a disolution of 2.5 mg/ml of K 2 CrO 4 were adsorbed, the obtained yields in high activity generators were about 85-90%, this second procedure was better, it lets us keep the column wet and it is not necessary to dry it with air, and in this way it can be carried out more easily and efficiently the elution procedure. (author)

Fast Torsional Artificial Muscles from NiTi Twisted Yarns.

Science.gov (United States)

Mirvakili, Seyed M; Hunter, Ian W

2017-05-17

Torsional artificial muscles made of multiwalled carbon nanotube/niobium nanowire yarns have shown remarkable torsional speed and gravimetric torque. The muscle structure consists of a twisted yarn with half of its length infiltrated with a stimuli-responsive guest material such as paraffin wax. The volumetric expansion of the guest material creates the torsional actuation in the yarn. In the present work, we show that this type of actuation is not unique to wax-infiltrated carbon multiwalled nanotube (MWCNT) or niobium nanowire yarns and that twisted yarn of NiTi alloy fibers also produces fast torsional actuation. By gold-plating half the length of a NiTi twisted yarn and Joule heating it, we achieved a fully reversible torsional actuation of up to 16°/mm with peak torsional speed of 10 500 rpm and gravimetric torque of 8 N·m/kg. These results favorably compare to those of MWCNTs and niobium nanowire yarns.

Twisted vertex algebras, bicharacter construction and boson-fermion correspondences

International Nuclear Information System (INIS)

Anguelova, Iana I.

2013-01-01

The boson-fermion correspondences are an important phenomena on the intersection of several areas in mathematical physics: representation theory, vertex algebras and conformal field theory, integrable systems, number theory, cohomology. Two such correspondences are well known: the types A and B (and their super extensions). As a main result of this paper we present a new boson-fermion correspondence of type D-A. Further, we define a new concept of twisted vertex algebra of order N, which generalizes super vertex algebra. We develop the bicharacter construction which we use for constructing classes of examples of twisted vertex algebras, as well as for deriving formulas for the operator product expansions, analytic continuations, and normal ordered products. By using the underlying Hopf algebra structure we prove general bicharacter formulas for the vacuum expectation values for two important groups of examples. We show that the correspondences of types B, C, and D-A are isomorphisms of twisted vertex algebras

Probing the interlayer coupling of twisted bilayer MoS2 using photoluminescence spectroscopy.

Science.gov (United States)

Huang, Shengxi; Ling, Xi; Liang, Liangbo; Kong, Jing; Terrones, Humberto; Meunier, Vincent; Dresselhaus, Mildred S

2014-10-08

Two-dimensional molybdenum disulfide (MoS2) is a promising material for optoelectronic devices due to its strong photoluminescence emission. In this work, the photoluminescence of twisted bilayer MoS2 is investigated, revealing a tunability of the interlayer coupling of bilayer MoS2. It is found that the photoluminescence intensity ratio of the trion and exciton reaches its maximum value for the twisted angle 0° or 60°, while for the twisted angle 30° or 90° the situation is the opposite. This is mainly attributed to the change of the trion binding energy. The first-principles density functional theory analysis further confirms the change of the interlayer coupling with the twisted angle, which interprets our experimental results.

Light hadrons from Nf=2+1+1 dynamical twisted mass fermions

NARCIS (Netherlands)

Baron, R.; Blossier, B.; Boucaud, P.; Carbonell, J.; Deuzeman, A.; Drach, V.; Farchioni, F.; Gimenez, V.; Herdoiza, G.; Jansen, K.; Michael, C.; Montvay, I.; Pallante, E.; Pène, O.; Reker, S.; Urbach, C.; Wagner, M.; Wenger, U.; Collaboration, for the ETM

2011-01-01

We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (Nf=2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at three values of the lattice spacing a~0.06

On the Compton Twist-3 Asymmetries

International Nuclear Information System (INIS)

Korotkiyan, V.M.; Teryaev, O.V.

1994-01-01

The 'fermionic poles' contribution to the twist-3 single asymmetry in the gluon Compton process is calculated. The 'gluonic poles' existence seems to contradict the density matrix positivity. Qualitative predictions for the direct photon and jets asymmetries are presented. 13 refs., 2 figs

TWIST1 a new determinant of epithelial to mesenchymal transition in EGFR mutated lung adenocarcinoma.

Directory of Open Access Journals (Sweden)

Karine Pallier

Full Text Available Metastasis is a multistep process and the main cause of mortality in lung cancer patients. We previously showed that EGFR mutations were associated with a copy number gain at a locus encompassing the TWIST1 gene on chromosome 7. TWIST1 is a highly conserved developmental gene involved in embryogenesis that may be reactivated in cancers promoting both malignant conversion and cancer progression through an epithelial to mesenchymal transition (EMT. The aim of this study was to investigate the possible implication of TWIST1 reactivation on the acquisition of a mesenchymal phenotype in EGFR mutated lung cancer. We studied a series of consecutive lung adenocarcinoma from Caucasian non-smokers for which surgical frozen samples were available (n = 33 and showed that TWIST1 expression was linked to EGFR mutations (P<0.001, to low CDH1 expression (P<0.05 and low disease free survival (P = 0.044. To validate that TWIST1 is a driver of EMT in EGFR mutated lung cancer, we used five human lung cancer cell lines and demonstrated that EMT and the associated cell mobility were dependent upon TWIST1 expression in cells with EGFR mutation. Moreover a decrease of EGFR pathway stimulation through EGF retrieval or an inhibition of TWIST1 expression by small RNA technology reversed the phenomenon. Collectively, our in vivo and in vitro findings support that TWIST1 collaborates with the EGF pathway in promoting EMT in EGFR mutated lung adenocarcinoma and that large series of EGFR mutated lung cancer patients are needed to further define the prognostic role of TWIST1 reactivation in this subgroup.

Study of twist boundaries in aluminium. Structure and intergranular diffusion

International Nuclear Information System (INIS)

Lemuet, Daniel

1981-01-01

This research thesis addresses the study of grain boundaries in oriented crystals, and more particularly the systematic calculation of intergranular structures and energies of twist boundaries of <001> axis in aluminium, the determination of intergranular diffusion coefficients of zinc in a set of twist bi-crystals of same axis encompassing a whole range of disorientations, and the search for a correlation between these experimental results and calculated structures

In vivo regional quantitation of intrathoracic /sup 99m/Tc using SPECT: concise communication

International Nuclear Information System (INIS)

Osborne, D.; Jaszczak, R.; Coleman, R.E.; Greer, K.; Lischko, M.

1982-01-01

A whole-body single-photon emission computed tomographic system (SPECT) was used to quantitate the activities of a series of /sup 99m/Tc point sources in the dog's thorax and to evaluate attenuation of a uniform esophageal line source containing a known concentration of /sup 99m/Tc. A first-order attenuation correction and an empirically derived attenuation coefficient of 0.09 cm-1 were used in the SPECT analyses of the intrathoracic point sources. The relationship between SPECT measurements of multiple point-source activities and the same sources measured in air was linear over a range of 100 to 1000 muCi (slope 1.08; R2 coefficient of determination 0.97). These data are sufficiently accurate to allow an estimate of the regional activity of radiopharmaceutical in the dog's thorax and justify their use in experimental quantitation of regional pulmonary perfusion

High performance twisted and coiled soft actuator with spandex fiber for artificial muscles

Science.gov (United States)

Yang, Sang Yul; Cho, Kyeong Ho; Kim, Youngeun; Song, Min-Geun; Jung, Ho Sang; Yoo, Ji Wang; Moon, Hyungpil; Koo, Ja Choon; Nam, Jae-do; Ryeol Choi, Hyouk

2017-10-01

This paper reports the twisted and coiled soft actuator (abbreviated with STCA) with spandex fiber. The STCA exhibits higher actuation strain at lower temperature than the previous nylon twisted and coiled soft actuators (abbreviated with NTCAs). While NTCAs are fabricated using a twist-insertion process until coils are formed, a new method is developed to fabricate the STCA using the ultra-stretch of spandex, whereby the STCA is twisted again after the coil has been formed. A 6-gear-twist-insertion device that increases the stability and the fabrication speed is developed to fabricate the STCA. The superior performance exhibited by the STCA is due to the 14% contraction strain of the bare spandex (bare nylon: 4%) and the low spring constant of 0.0115 N mm-1. The maximum tensile actuation strain of STCA was 45% at 130 °C, and the maximum specific work was 1.523 kJ kg-1 at 130 °C. STCA could repeatedly actuate 100 times with a strain change of less than 0.4%.

IRONY IN CHARLES DICKEN'S OLIVER TWIST

Directory of Open Access Journals (Sweden)

Ika Kana Trisnawati

2016-05-01

Full Text Available This paper describes the types of irony used by Charles Dickens in his notable early work, Oliver Twist, as well as the reasons the irony was chosen. As a figurative language, irony is utilized to express one’s complex feelings without truly saying them. In Oliver Twist, Dickens brought the readers some real social issues wrapped in dark, deep written expressions of irony uttered by the characters of his novel. Undoubtedly, the novel had left an impact to the British society at the time. The irony Dickens displayed here includes verbal, situational, and dramatic irony. His choice of irony made sense as he intended to criticize the English Poor Laws and to touch the public sentiment. He wanted to let the readers go beyond what was literally written and once they discovered what the truth was, they would eventually understand Dickens’ purposes.

FuGEFlow: data model and markup language for flow cytometry

Directory of Open Access Journals (Sweden)

Manion Frank J

2009-06-01

Full Text Available Abstract Background Flow cytometry technology is widely used in both health care and research. The rapid expansion of flow cytometry applications has outpaced the development of data storage and analysis tools. Collaborative efforts being taken to eliminate this gap include building common vocabularies and ontologies, designing generic data models, and defining data exchange formats. The Minimum Information about a Flow Cytometry Experiment (MIFlowCyt standard was recently adopted by the International Society for Advancement of Cytometry. This standard guides researchers on the information that should be included in peer reviewed publications, but it is insufficient for data exchange and integration between computational systems. The Functional Genomics Experiment (FuGE formalizes common aspects of comprehensive and high throughput experiments across different biological technologies. We have extended FuGE object model to accommodate flow cytometry data and metadata. Methods We used the MagicDraw modelling tool to design a UML model (Flow-OM according to the FuGE extension guidelines and the AndroMDA toolkit to transform the model to a markup language (Flow-ML. We mapped each MIFlowCyt term to either an existing FuGE class or to a new FuGEFlow class. The development environment was validated by comparing the official FuGE XSD to the schema we generated from the FuGE object model using our configuration. After the Flow-OM model was completed, the final version of the Flow-ML was generated and validated against an example MIFlowCyt compliant experiment description. Results The extension of FuGE for flow cytometry has resulted in a generic FuGE-compliant data model (FuGEFlow, which accommodates and links together all information required by MIFlowCyt. The FuGEFlow model can be used to build software and databases using FuGE software toolkits to facilitate automated exchange and manipulation of potentially large flow cytometry experimental data sets

FuGEFlow: data model and markup language for flow cytometry.

Science.gov (United States)

Qian, Yu; Tchuvatkina, Olga; Spidlen, Josef; Wilkinson, Peter; Gasparetto, Maura; Jones, Andrew R; Manion, Frank J; Scheuermann, Richard H; Sekaly, Rafick-Pierre; Brinkman, Ryan R

2009-06-16

Flow cytometry technology is widely used in both health care and research. The rapid expansion of flow cytometry applications has outpaced the development of data storage and analysis tools. Collaborative efforts being taken to eliminate this gap include building common vocabularies and ontologies, designing generic data models, and defining data exchange formats. The Minimum Information about a Flow Cytometry Experiment (MIFlowCyt) standard was recently adopted by the International Society for Advancement of Cytometry. This standard guides researchers on the information that should be included in peer reviewed publications, but it is insufficient for data exchange and integration between computational systems. The Functional Genomics Experiment (FuGE) formalizes common aspects of comprehensive and high throughput experiments across different biological technologies. We have extended FuGE object model to accommodate flow cytometry data and metadata. We used the MagicDraw modelling tool to design a UML model (Flow-OM) according to the FuGE extension guidelines and the AndroMDA toolkit to transform the model to a markup language (Flow-ML). We mapped each MIFlowCyt term to either an existing FuGE class or to a new FuGEFlow class. The development environment was validated by comparing the official FuGE XSD to the schema we generated from the FuGE object model using our configuration. After the Flow-OM model was completed, the final version of the Flow-ML was generated and validated against an example MIFlowCyt compliant experiment description. The extension of FuGE for flow cytometry has resulted in a generic FuGE-compliant data model (FuGEFlow), which accommodates and links together all information required by MIFlowCyt. The FuGEFlow model can be used to build software and databases using FuGE software toolkits to facilitate automated exchange and manipulation of potentially large flow cytometry experimental data sets. Additional project documentation, including

Development of methodology for evaluation of {sup 99m}Tc and {sup 131}I incorporated activities during lactation; Desenvolvimento de metodologia para avaliacao da atividade de {sup 99m}Tc e {sup 131}I em lactantes

Energy Technology Data Exchange (ETDEWEB)

Santos, L. [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica; Dantas, A.L.A.; Mesquita, S.A. [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica; Oliveira, S.M.V., E-mail: adantas@ird.gov.br, E-mail: silvia@ird.gov.br [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica; Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Dosimetria

2012-07-01

Internal contamination of babies may occur for milk ingestion or inhalation of mothers occupationally exposed to ionizing radiation with possible incorporation or mothers submitted to medical exposures during lactation. Radionuclide concentrations in the mother's milk may cause organ absorbed doses in the babies proportionally to the breast volumes. Milk analysis allow to determine activities ingested by the babies by determining the peak of mother's milk considering the decrease of the activity rate and the milk activities drunk at different time intervals. The work had the aim to develop simulators and methodology to evaluate {sup 99m}Tc and {sup 131}I in lactation, in the following steps: to prepare standard solution of contaminated milk separately with {sup 99m}Tc and {sup 131}I; to build four breast simulators (600 g and 800 g) and respective calibration for two geometries (breast and whole-body) in the Whole-Body Counter Unit in Instituto de Radioprotecao e Dosimetria. The results demonstrated the system efficiency to determine {sup 99m}Tc and {sup 131}I activities in breasts during the lactation period. The methodology for positioning in the 'breast geometry' seemed to be more efficient than the 'whole-body geometry' for different breast volumes. The experiment allows achieving better evaluation of internal dosimetry of mothers and their young children. (author)

Twist1 Controls a Cell-Specification Switch Governing Cell Fate Decisions within the Cardiac Neural Crest

Science.gov (United States)

Vincentz, Joshua W.; Firulli, Beth A.; Lin, Andrea; Spicer, Douglas B.; Howard, Marthe J.; Firulli, Anthony B.

2013-01-01

Neural crest cells are multipotent progenitor cells that can generate both ectodermal cell types, such as neurons, and mesodermal cell types, such as smooth muscle. The mechanisms controlling this cell fate choice are not known. The basic Helix-loop-Helix (bHLH) transcription factor Twist1 is expressed throughout the migratory and post-migratory cardiac neural crest. Twist1 ablation or mutation of the Twist-box causes differentiation of ectopic neuronal cells, which molecularly resemble sympathetic ganglia, in the cardiac outflow tract. Twist1 interacts with the pro-neural factor Sox10 via its Twist-box domain and binds to the Phox2b promoter to repress transcriptional activity. Mesodermal cardiac neural crest trans-differentiation into ectodermal sympathetic ganglia-like neurons is dependent upon Phox2b function. Ectopic Twist1 expression in neural crest precursors disrupts sympathetic neurogenesis. These data demonstrate that Twist1 functions in post-migratory neural crest cells to repress pro-neural factors and thereby regulate cell fate determination between ectodermal and mesodermal lineages. PMID:23555309

Higher twist effects in QCD description of light meson exclusive formfactors

International Nuclear Information System (INIS)

Gorskij, A.S.

1987-01-01

The general approach to a quantitative description of higher twist effects in hard exclusive processes in QCD is proposed. The consistent calculations in coordinate space and the choice of special gauges for quantum and classical gluon fields are essential ingradients of this method. The self consistent system of twist three wave functions for π-meson has been built

Wrinkles, loops, and topological defects in twisted ribbons

Science.gov (United States)

Chopin, Julien

Nature abounds with elastic ribbon like shapes including double-stranded semiflexible polymers, graphene and metal oxide nanoribbons which are examples of elongated elastic structures with a strongly anisotropic cross-section. Due to this specific geometry, it is far from trivial to anticipate if a ribbon should be considered as a flat flexible filament or a narrow thin plate. We thus perform an experiment in which a thin elastic ribbon is loaded using a twisting and traction device coupled with a micro X-ray computed tomography machine allowing a full 3D shape reconstruction. A wealth of morphological behaviors can be observed including wrinkled helicoids, curled and looped configurations, and faceted ribbons. In this talk, I will show that most morphologies can be understood using a far-from-threshold approach and simple scaling arguments. Further, we find that the various shapes can be organized in a phase diagram using the twist, the tension, and the geometry of the ribbon as control parameters. Finally, I will discuss the spontaneous formation of topological defects with negatively-signed Gaussian charge at large twist and small but finite stretch.

Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review.

Science.gov (United States)

Budinski, Vedran; Donlagic, Denis

2017-02-23

Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation.Invited Paper.

Chemistry of /sup 99m/Tc labeling kits

International Nuclear Information System (INIS)

Srivastava, S.C.; Meinken, G.; Richards, P.

1976-01-01

Problems have been reported with the use of kit-produced /sup 99m/Tc radiopharmaceuticals. This study was undertaken to understand the chemistry involved in various stannous kit systems. The relation between Tc, tin, and the ligands used to complex the reduced Tc was investigated. It is concluded that for reliable performance, stannous kits should be prepared so that most of the tin is kept in the usable (reducing) form; a solution would be to use minimum tin and a large excess of complexing agent. Oxidation of the Tc complex to free pertechnetate is not a major problem in most kit systems. 5 figures

Stability of short wavelength tearing and twisting modes

International Nuclear Information System (INIS)

Waelbroeck, F.L.

1998-01-01

The stability and mutual interaction of tearing and twisting modes in a torus is governed by matrices that generalize the well-known Δ' stability index. The diagonal elements of these matrices determine the intrinsic stability of modes that reconnect the magnetic field at a single resonant surface. The off-diagonal elements indicate the strength of the coupling between the different modes. The author shows how the elements of these matrices can be evaluated, in the limit of short wavelength, from the free energy driving radially extended ballooning modes. The author applies the results by calculating the tearing and twisting Δ' for a model high-beta equilibrium with circular flux surfaces

Determination of radiochemical yield of {sup 99m}Tc radiopharmaceutical preparations using gamma counter and linear radiochromatography scanner

Energy Technology Data Exchange (ETDEWEB)

Martins, Patricia de A.; Moura, Rebeca G.; Shiki, Andressa M.; Fukumori, Neuza T.O.; Matsuda, Margareth M.N., E-mail: patyosborne@yahoo.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

The radiochemical purity (RCP) evaluation is a prerequisite for radiopharmaceuticals before the administration in patients. RCP is defined as the proportion of the total radioactivity in the product that is present in the specified chemical form. The most widely used techniques for RCP determination in radiopharmaceutical preparations are thin layer chromatography (TLC-Al), instant thin layer chromatography (ITLC-SG) and paper chromatography (PC). These techniques combined with radioactivity detection are one of the most important tools in the RCP of the radiopharmaceutical compounds. Several methods are used for the determination of the spatial distribution of radioactivity on the strips. The aim of this study was to compare two methods for radioactivity measurement in the determination of RCP in {sup 99m}Tc radiopharmaceuticals using gamma counter and linear radiochromatography scanner. Lyophilized radiopharmaceuticals were labeled with {sup 99m}Tc. The analysis was carried out using TLC-Al and high performance thin layer chromatography (HPTLC-Cellulose) sheets, ITLC-SG and 3MM Whatman PC. The radioactivity distribution was determined by counting each strip during 1 minute in a radiochromatography TLC scanner. For comparison, the strips were cut into small pieces and each one was separately measured in a gamma-counter during 0.20 minutes in 70-210 KeV {sup 99m}Tc window. USP 36 and FDA specify that not less than 90% of the total radioactivity must be in the spot corresponding to {sup 99m}Tc labeled compound. In conclusion, the procedure for RCP determination of ALBUMINA-TEC, DEX500-TEC, ECD-TEC, MACRO-TEC and MIBI-TEC can be faster using radiochromatography. (author)

Twist deformations leading to κ-Poincaré Hopf algebra and their application to physics

International Nuclear Information System (INIS)

Jurić, Tajron; Meljanac, Stjepan; Samsarov, Andjelo

2016-01-01

We consider two twist operators that lead to kappa-Poincaré Hopf algebra, the first being an Abelian one and the second corresponding to a light-like kappa-deformation of Poincaré algebra. The adventage of the second one is that it is expressed solely in terms of Poincaré generators. In contrast to this, the Abelian twist goes out of the boundaries of Poincaré algebra and runs into envelope of the general linear algebra. Some of the physical applications of these two different twist operators are considered. In particular, we use the Abelian twist to construct the statistics flip operator compatible with the action of deformed symmetry group. Furthermore, we use the light-like twist operator to define a star product and subsequently to formulate a free scalar field theory compatible with kappa-Poincaré Hopf algebra and appropriate for considering the interacting ϕ 4 scalar field model on kappa-deformed space. (paper)

Modeling and development of a twisting wing using inductively heated shape memory alloy actuators

Science.gov (United States)

Saunders, Robert N.; Hartl, Darren J.; Boyd, James G.; Lagoudas, Dimitris C.

2015-04-01

Wing twisting has been shown to improve aircraft flight performance. The potential benefits of a twisting wing are often outweighed by the mass of the system required to twist the wing. Shape memory alloy (SMA) actuators repeatedly demonstrate abilities and properties that are ideal for aerospace actuation systems. Recent advances have shown an SMA torsional actuator that can be manufactured and trained with the ability to generate large twisting deformations under substantial loading. The primary disadvantage of implementing large SMA actuators has been their slow actuation time compared to conventional actuators. However, inductive heating of an SMA actuator allows it to generate a full actuation cycle in just seconds rather than minutes while still . The aim of this work is to demonstrate an experimental wing being twisted to approximately 10 degrees by using an inductively heated SMA torsional actuator. This study also considers a 3-D electromagnetic thermo-mechanical model of the SMA-wing system and compare these results to experiments to demonstrate modeling capabilities.

Borel resummation of soft gluon radiation and higher twists

International Nuclear Information System (INIS)

Forte, Stefano; Ridolfi, Giovanni; Rojo, Joan; Ubiali, Maria

2006-01-01

We show that the well-known divergence of the perturbative expansion of resummed results for processes such as deep-inelastic scattering and Drell-Yan in the soft limit can be treated by Borel resummation. The divergence in the Borel inversion can be removed by the inclusion of suitable higher twist terms. This provides us with an alternative to the standard 'minimal prescription' for the asymptotic summation of the perturbative expansion, and it gives us some handle on the role of higher twist corrections in the soft resummation region

Note on twisted elliptic genus of K3 surface

International Nuclear Information System (INIS)

Eguchi, Tohru; Hikami, Kazuhiro

2011-01-01

We discuss the possibility of Mathieu group M 24 acting as symmetry group on the K3 elliptic genus as proposed recently by Ooguri, Tachikawa and one of the present authors. One way of testing this proposal is to derive the twisted elliptic genera for all conjugacy classes of M 24 so that we can determine the unique decomposition of expansion coefficients of K3 elliptic genus into irreducible representations of M 24 . In this Letter we obtain all the hitherto unknown twisted elliptic genera and find a strong evidence of Mathieu moonshine.

Polarization-dependent diffraction in all-dielectric, twisted-band structures

Energy Technology Data Exchange (ETDEWEB)

Kardaś, Tomasz M.; Jagodnicka, Anna; Wasylczyk, Piotr, E-mail: pwasylcz@fuw.edu.pl [Photonic Nanostructure Facility, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warszawa (Poland)

2015-11-23

We propose a concept for light polarization management: polarization-dependent diffraction in all-dielectric microstructures. Numerical simulations of light propagation show that with an appropriately configured array of twisted bands, such structures may exhibit zero birefringence and at the same time diffract two circular polarizations with different efficiencies. Non-birefringent structures as thin as 3 μm have a significant difference in diffraction efficiency for left- and right-hand circular polarizations. We identify the structural parameters of such twisted-band matrices for optimum performance as circular polarizers.

An in-line fiber-optic modal interferometer for simultaneous measurement of twist and ambient temperature

Directory of Open Access Journals (Sweden)

Yongqin Yu

2014-12-01

Full Text Available A novel and simple sensor based on fiber-optic modal interferometer fabricated by a segment of low elliptical hollow-core photonic bandgap fiber for simultaneous temperature and twist measurements is demonstrated. Meanwhile the sensor can also measure the twist angle and determine the twist direction simultaneously. The mode distribution of EHC-PBGF is demonstrated both in theory and experiments. There is an obvious difference of two transmission dips on the temperature and twist. The twist sensitivities of Dip 1 and Dip 2 are obtained to be −31.95 and −585.8 pm/(rad/m, respectively. The temperature sensitivities are 12.99 pm/°C for Dip 1 and 5.09 pm/°C for Dip 2, respectively. Two parameters of twist and temperature can be distinguished and measured simultaneously by using a sensing matrix. Meanwhile the structure is found to be weakly sensitive to the axial strain. It has the advantage of avoiding the crosstalk of strain in the applications.

Spaceflight Flow Cytometry: Design Challenges and Applications

Science.gov (United States)

Pappas, Dimitri; Kao, Shih-Hsin; Jeevarajan, Antony S.

2004-01-01

Future space exploration missions will require analytical technology capable of providing both autonomous medical care to the crew and investigative capabilities to researchers. While several promising candidate technologies exist for further development, flow cytometry is an attractive technology as it offers both crew health and a wide array of biochemistry and immunology assays. While flow cytometry has been widely used for cellular analysis in both clinical and research settings, the requirements for proper operation in spaceflight impose constraints on any instrument designs. The challenges of designing a spaceflight-ready flow cytometer are discussed, as well as some preliminary results using a prototype system.

Twisted Vector Bundles on Pointed Nodal Curves

Indian Academy of Sciences (India)

Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

Topological twist in four dimensions, R-duality and hyperinstantons

International Nuclear Information System (INIS)

Anselmi, D.; Fre, P.

1993-01-01

In this paper we continue the programme of topologically twisting N=2 theories in D=4, focusing on the coupling of vector multiplets to N=2 supergravity. We show that in the minimal case, namely when the special gometry prepotential F(X) is a quadratic polynomial, the theory has a so far unknown on-shell U(1) symmetry, that we name R-duality. R-duality is a generalization of the chiral-dual on-shell symmetry of N=2 pure supergravity and of the R-symmetry of N=2 super Yang-Mills theory. Thanks to this, the theory can be topologically twisted and topologically shifted, precisely as pure N=2 supergravity, to yield a natural coupling of topological gravity to topological Yang-Mills theory. The gauge-fixing condition that emerges from the twisting is the self-duality condition on the gauge field strength and on the spin connection. Hence our theory reduces to intersection theory in the moduli-space of gauge instantons living in gravitational instanton backgrounds. We remark that, for deep properties of the parent N=2 theory, the topological Yang-Mills theory we obtain by taking the flat space limit of our gravity-coupled lagrangian is different from the Donaldson theory constructed by Witten. Whether this difference is substantial and what its geometrical implications may be is yet to be seen. We also discuss the topological twist of the hypermultiplets leading to topological quaternionic sigma-models. The instantons of these models, named by us hyperinstantons, correspond to a notion of triholomorphic mappings discussed in the paper. In all cases the new ghost number is the sum of the old ghost number plus the R-duality charge. The observables described by the theory are briefly discussed. In conclusion, the topological twist of the complete N=2 theory defines intersection theory in the moduli-space of gauge instantons plus gravitational instantons plus hyperinstantons. This is possibly a new subject for further mathematical investigation. (orig.)

Controlling coupled bending-twisting vibrations of anisotropic composite wing

Science.gov (United States)

Ryabov, Victor; Yartsev, Boris

2018-05-01

The paper discusses the possibility to control coupled bending-twisting vibrations of anisotropic composite wing by means of the monoclinic structures in the reinforcement of the plating. Decomposing the potential straining energy and kinetic energy of natural vibration modes into interacting and non-interacting parts, it became possible to introduce the two coefficients that integrally consider the effect of geometry and reinforcement structure upon the dynamic response parameters of the wing. The first of these coefficients describes the elastic coupling of the natural vibration modes, the second coefficient describes the inertial one. The paper describes the numerical studies showing how the orientation of considerably anisotropic CRP layers in the plating affects natural frequencies, loss factors, coefficients of elastic and inertial coupling for several lower tones of natural bending-twisting vibrations of the wing. Besides, for each vibration mode, partial values of the above mentioned dynamic response parameters were determined by means of the relationships for orthotropic structures where instead of "free" shearing modulus in the reinforcement plant, "pure" shearing modulus is used. Joint analysis of the obtained results has shown that each pair of bending-twisting vibration modes has its orientation angle ranges of the reinforcing layers where the inertial coupling caused by asymmetry of the cross-section profile with respect to the main axes of inertia decreases, down to the complete extinction, due to the generation of the elastic coupling in the plating material. These ranges are characterized by the two main features: 1) the difference in the natural frequencies of the investigated pair of bending-twisting vibration modes is the minimum and 2) natural frequencies of bending-twisting vibrations belong to a stretch restricted by corresponding partial natural frequencies of the investigated pair of vibration modes. This result is of practical importance

Flow cytometry measurements of human chromosome kinetochore labeling

International Nuclear Information System (INIS)

Fantes, J.A.; Green, D.K.; Malloy, P.; Sumner, A.T.

1989-01-01

A method for the preparation and measurement of immunofluorescent human chromosome centromeres in suspension is described using CREST antibodies, which bind to the centromeric region of chromosomes. Fluorescein isothiocyanate (FITC)-conjugated antihuman antibodies provide the fluorescent label. Labeled chromosomes are examined on microscope slides and by flow cytometry. In both cases a dye which binds to DNA is added to provide identification of the chromosome groups. Sera from different CREST patients vary in their ability to bind to chromosome arms in addition to the centromeric region. Flow cytometry and microfluorimetry measurements have shown that with a given CREST serum the differences in kinetochore fluorescence between chromosomes are only minor. Flow cytometry experiments to relate the number of dicentric chromosomes, induced by in vitro radiation of peripheral blood cells to the slightly increased number of chromosomes with above-average kinetochore fluorescence did not produce decisive radiation dosimetry results

Hardy Inequalities in Globally Twisted Waveguides

Czech Academy of Sciences Publication Activity Database

Briet, Ph.; Hammedi, H.; Krejčiřík, David

2015-01-01

Roč. 105, č. 7 (2015), s. 939-958 ISSN 0377-9017 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : quantum waveguides * twisted tubes * Dirichlet Laplacian * Hardy inequality Subject RIV: BE - Theoretical Physics Impact factor: 1.517, year: 2015

One-dimensional structures behind twisted and untwisted superYang-Mills theory

CERN Document Server

Baulieu, Laurent

2011-01-01

We give a one-dimensional interpretation of the four-dimensional twisted N=1 superYang-Mills theory on a Kaehler manifold by performing an appropriate dimensional reduction. We prove the existence of a 6-generator superalgebra, which does not possess any invariant Lagrangian but contains two different subalgebras that determine the twisted and untwisted formulations of the N=1 superYang-Mills theory.

Studies on {sup 99}Mo-{sup 99m}Tc adsorption and elution behaviors using the inorganic sorbent ceric tungstate and conventional organic resins

Energy Technology Data Exchange (ETDEWEB)

El-Sweify, Fatma H.; Fattah, Alaa El-Din A. Abdel; Aly, Shorouk M.; Ghamry, Mohamed A. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories Center; El-Sheikh, Ragaa [Zagazig Univ. (Egypt). Chemistry Dept.

2017-09-01

Adsorption behavior of {sup 99}Mo(VI) and {sup 99m}Tc(VII) was studied on ceric tungstate (CeW) and compared with the adsorption on the conventional cation and anion exchangers Dowex-50X8 and AG-2X8, respectively. The studies were carried out under static and dynamic conditions. The effect of contact time and pH on the adsorption was investigated under static conditions. High K{sub d}-values for sorption of {sup 99}Mo(VI) on (CeW) were obtained over the investigated pH range. {sup 99m}Tc was adsorbed with much lower K{sub d}-values. The K{sub d}-values were pH dependent. K{sub d}-values of {sup 99}Mo-adsorption on AG-2X8 were lower than those on (CeW) and vice versa for {sup 99m}Tc. Ionic species of both elements were not adsorbed on Dowex-50X8, indicating the absence of cationic species and the adsorption of both elements on AG-2X8 and (CeW) as anionic species. The loading and elution behaviors of {sup 99}Mo and {sup 99m}Tc on (CeW) were studied using different eluents. {sup 99}Mo remained strongly adsorbed under all conditions whereas {sup 99m}Tc was easily eluted. Adsorption of some fission products, i.e. {sup 95}Zr(IV) and {sup 95}Nb(V), in addition to {sup 123m}Te(IV) and {sup 75}Se(IV), as representatives of their corresponding fission product isotopes, as well as {sup 181}Hf, as probable radioactive contaminant was also studied. Solutions of the ionic species of those metals were loaded in mixtures together with {sup 99}Mo on (CeW) columns. Strong adsorption of those ionic species and {sup 99}Mo on (CeW) was found whereas {sup 99m}Tc was easily eluted. Different eluents were investigated for eluting {sup 99m}Tc from {sup 99}Mo-adsorbed on (CeW).

Twisted mass, overlap and Creutz fermions. Cut-off effects at tree-level of perturbation theory

International Nuclear Information System (INIS)

Cichy, K.; Kujawa, A.; Jansen, K.; Shindler, A.

2008-02-01

We study cutoff effects at tree-level of perturbation theory for maximally twisted mass Wilson, overlap and the recently proposed Creutz fermions. We demonstrate that all three kind of lattice fermions exhibit the expected O(a 2 ) scaling behaviour in the lattice spacing. In addition, the sizes of these cutoff effects are comparable for the three kinds of lattice fermions considered here. Furthermore, we analyze situations when twisted mass fermions are not exactly at maximal twist and when overlap fermions are studied in comparison to twisted mass fermions when the quark masses are not matched. (orig.)

Twist and snai1 expression in pharyngeal squamous cell carcinoma stroma is related to cancer progression

International Nuclear Information System (INIS)

Jouppila-Mättö, Anna; Närkiö-Mäkelä, Mervi; Soini, Ylermi; Pukkila, Matti; Sironen, Reijo; Tuhkanen, Hanna; Mannermaa, Arto; Kosma, Veli-Matti

2011-01-01

Epithelial-mesenchymal transition (EMT) is a crucial process in tumorigenesis since tumor cells attain fibroblast-like features enabling them to invade to surrounding tissue. Two transcription factors, TWIST and SNAI1, are fundamental in regulating EMT. Immunohistochemistry was used to study the expression of TWIST and SNAI1 in 109 pharyngeal squamous cell carcinomas. Tumors with intense stromal staining of TWIST relapsed more frequently (p = 0.04). Tumors with both positive TWIST and SNAI1 immunoreactivity in the stroma were at least Stage II (p = 0.05) and located more often in hypopharynx (p = 0.035). Tumors with negative immunostaining of TWIST and SNAI1 in the stromal compartment were smaller (T1-2) (p = 0.008), less advanced (SI-II) (p = 0.031) and located more often in the oropharynx (p = 0.007). Patients with negative SNAI1 and TWIST immunostaining in tumor stroma had a better 5-year disease-specific and overall survival (p = 0.037 and p = 0.014 respectively). TWIST and SNAI1 expression in stromal cells is associated with clinical and histopathological characteristics that indicate progressive disease. Negative expression of these EMT-promoting transcription factors predicts a better outcome

On the dose calculation at the cellular level and its implications for the RBE of {sup 99m}Tc and {sup 123}I

Energy Technology Data Exchange (ETDEWEB)

Freudenberg, R., E-mail: robert.freudenberg@uniklinikum-dresden.de; Runge, R.; Maucksch, U.; Berger, V.; Kotzerke, J. [University Hospital/Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Saxony 01307 (Germany)

2014-06-15

Purpose: Based on the authors’ previous findings concerning the radiotoxicity of{sup 99m}Tc, the authors compared the cellular survival under the influence of this nuclide with that following exposure to the Auger electron emitter {sup 123}I. To evaluate the relative biological effectiveness (RBE) of both radionuclides, knowledge of the absorbed dose is essential. Thus, the authors present the dose calculations and discuss the results based on different models of the radionuclide distribution. Both different target volumes and the influence of the uptake kinetics were considered. Methods: Rat thyroid PC Cl3 cells in culture were incubated with either{sup 99m}Tc or {sup 123}I or were irradiated using 200 kV x-rays in the presence or absence of perchlorate. The clonogenic cell survival was measured via colony formation. In addition, the intracellular radionuclide uptake was quantified. Single-cell dose calculations were based on Monte Carlo simulations performed using Geant4. Results: Compared with external radiation using x-rays (D{sub 37} = 2.6 Gy), the radionuclides {sup 99m}Tc (D{sub 37} = 3.5 Gy), and {sup 123}I (D{sub 37} = 3.8 Gy) were less toxic in the presence of perchlorate. In the absence of perchlorate, the amount of activity a{sub 37} that was necessary to reduce the surviving fraction (SF) to 0.37 was 22.8 times lower for {sup 99m}Tc and 12.4 times lower for {sup 123}I because of the dose increase caused by intracellular radionuclide accumulation. When the cell nucleus was considered as the target for the dose calculation, the authors found a RBE of 2.18 for {sup 99m}Tc and RBE = 3.43 for {sup 123}I. Meanwhile, regarding the dose to the entire cell, RBE = 0.75 for {sup 99m}Tc and RBE = 1.87 for {sup 123}I. The dose to the entire cell was chosen as the dose criterion because of the intracellular radionuclide accumulation, which was found to occur solely in the cytoplasm. The calculated number of intracellular decays per cell was (975 ± 109) decays

Use of pyrophosphate-/sup 99m/Tc in diagnosis of malignant tumors of bones

Energy Technology Data Exchange (ETDEWEB)

Kasatkin, Yu N; Purizhanskii, I I; Survila, Z P; Agranat, V Z; Korsunskii, V N

1976-10-01

Pyrophosphate-/sup 99m/Tc was administered intravenously in a dose of 0.05 to 0.08 mCi per 1 kg body weight of the patient. Studies were made after 4, 6, and 24 hours with fixed and movable detectors. During investigations a gamma-chamber magnetic memory and a 4096-channel analyzer were also used. A quantitative processing of the material was made. The authors determined distribution of the preparation in normal and pathological bone tissue. A total of 142 patients with tumors of the bone tissue were examined; 858 radioisotope measurements were made. An analysis of accumulation of pyrophosphate-/sup 99m/Tc in primary osteogenic tumors in systemic affections of the bones and bone metastases was made. There is a relation between the concentration of the radiopharmaceutical preparation and the morphological structure of the tumor. Reduction in the accumulation of the radioactive indicator took place after radiation and medicinal effect, this made it possible to judge the regression of the tumor.

Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review

Directory of Open Access Journals (Sweden)

Vedran Budinski

2017-02-01

Full Text Available Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation.Invited Paper

Labelling of bilirubin with /sup 99m/Tc and pharmacokinetic behavior

International Nuclear Information System (INIS)

Kaempfer, I.; Schneider, G.; Blottner, A.; Deckart, H.; Staedtisches Klinikum Berlin-Buch

1982-01-01

The yield of the bilirubin labelling with /sup 99m/Tc amounted to 97%. The labelled complex has been stable for 24 hours with the pH range 2-7.5. As evidenced in animal experiments the labelled bilirubin is probably subjected to natural degradation processes. Side effects could not be noticed. A disadvantage seems to be the slow transfer of /sup 99m/Tc-bilirubin from the hepatic cell to the biliary capillary

Design and analysis of variable-twist tiltrotor blades using shape memory alloy hybrid composites

International Nuclear Information System (INIS)

Park, Jae-Sang; Kim, Seong-Hwan; Jung, Sung Nam; Lee, Myeong-Kyu

2011-01-01

The tiltrotor blade, or proprotor, acts as a rotor in the helicopter mode and as a propeller in the airplane mode. For a better performance, the proprotor should have different built-in twist distributions along the blade span, suitable for each operational mode. This paper proposes a new variable-twist proprotor concept that can adjust the built-in twist distribution for given flight modes. For a variable-twist control, the present proprotor adopts shape memory alloy hybrid composites (SMAHC) containing shape memory alloy (SMA) wires embedded in the composite matrix. The proprotor of the Korea Aerospace Research Institute (KARI) Smart Unmanned Aerial Vehicle (SUAV), which is based on the tiltrotor concept, is used as a baseline proprotor model. The cross-sectional properties of the variable-twist proprotor are designed to maintain the cross-sectional properties of the original proprotor as closely as possible. However, the torsion stiffness is significantly reduced to accommodate the variable-twist control. A nonlinear flexible multibody dynamic analysis is employed to investigate the dynamic characteristics of the proprotor such as natural frequency and damping in the whirl flutter mode, the blade structural loads in a transition flight and the rotor performance in hover. The numerical results show that the present proprotor is designed to have a strong similarity to the baseline proprotor in dynamic and load characteristics. It is demonstrated that the present proprotor concept could be used to improve the hover performance adaptively when the variable-twist control using the SMAHC is applied appropriately

Design and analysis of variable-twist tiltrotor blades using shape memory alloy hybrid composites

Science.gov (United States)

Park, Jae-Sang; Kim, Seong-Hwan; Jung, Sung Nam; Lee, Myeong-Kyu

2011-01-01

The tiltrotor blade, or proprotor, acts as a rotor in the helicopter mode and as a propeller in the airplane mode. For a better performance, the proprotor should have different built-in twist distributions along the blade span, suitable for each operational mode. This paper proposes a new variable-twist proprotor concept that can adjust the built-in twist distribution for given flight modes. For a variable-twist control, the present proprotor adopts shape memory alloy hybrid composites (SMAHC) containing shape memory alloy (SMA) wires embedded in the composite matrix. The proprotor of the Korea Aerospace Research Institute (KARI) Smart Unmanned Aerial Vehicle (SUAV), which is based on the tiltrotor concept, is used as a baseline proprotor model. The cross-sectional properties of the variable-twist proprotor are designed to maintain the cross-sectional properties of the original proprotor as closely as possible. However, the torsion stiffness is significantly reduced to accommodate the variable-twist control. A nonlinear flexible multibody dynamic analysis is employed to investigate the dynamic characteristics of the proprotor such as natural frequency and damping in the whirl flutter mode, the blade structural loads in a transition flight and the rotor performance in hover. The numerical results show that the present proprotor is designed to have a strong similarity to the baseline proprotor in dynamic and load characteristics. It is demonstrated that the present proprotor concept could be used to improve the hover performance adaptively when the variable-twist control using the SMAHC is applied appropriately.

'Twisted tape sign': Its significance in recurrent sigmoid volvulus

International Nuclear Information System (INIS)

Gopal, K.; Lim, Y.; Banerjee, B.

2005-01-01

Aim: Sigmoid volvulus is a common cause of intestinal obstruction in the elderly. Mild attacks of sigmoid volvulus may be more difficult to diagnose due to the lack of severity of symptoms which may resolve spontaneously only to recur after an interval. This study was a review of patients to assess the incidence of the 'twisted tape sign' and to evaluate the significance of its presence in cases of recurrent sigmoid volvulus. Methods and materials: A retrospective study over eight years revealed six cases of surgically confirmed recurrent sigmoid volvulus. Case records and barium enemas of all patients were reviewed. Results: Six patients were identified, including four men and two women, with a median age of 56 years. Diagnostic difficulties were encountered in four (67%) patients with a delay ranging between 10 and 37 months with a mean 17.3 months. Twisted tape sign was confirmed on all barium examinations retrospectively. Conclusion: Recognition of twisted tape sign on barium enema examination along with an appropriate clinical history would suggest a diagnosis of recurrent sigmoid volvulus

Twist-3 effect from the longitudinally polarized proton for ALT in hadron production from pp collisions

Directory of Open Access Journals (Sweden)

Yuji Koike

2016-08-01

Full Text Available We compute the contribution from the longitudinally polarized proton to the twist-3 double-spin asymmetry ALT in inclusive (light hadron production from proton–proton collisions, i.e., p↑p→→hX. We show that using the relevant QCD equation-of-motion relation and Lorentz invariance relation allows one to eliminate the twist-3 quark-gluon correlator (associated with the longitudinally polarized proton in favor of one-variable twist-3 quark distributions and the (twist-2 transversity parton density. Including this result with the twist-3 pieces associated with the transversely polarized proton and unpolarized final-state hadron (which have already been calculated in the literature, we now have the complete leading-order cross section for this process.

Calculations of higher twist distribution functions in the MIT bag model

International Nuclear Information System (INIS)

Signal, A.I.

1997-01-01

We calculate all twist-2, -3 and -4 parton distribution functions involving two quark correlations using the wave function of the MIT bag model. The distributions are evolved up to experimental scales and combined to give the various nucleon structure functions. Comparisons with recent experimental data on higher twist structure functions at moderate values of Q 2 give good agreement with the calculated structure functions. (orig.)

One-dimensional structures behind twisted and untwisted super Yang-Mills theory

Energy Technology Data Exchange (ETDEWEB)

Baulieu, Laurent [CERN, Geneve (Switzerland). Theoretical Div.; Toppan, Francesco, E-mail: baulieu@lpthe.jussieu.f, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

2010-07-01

We give a one-dimensional interpretation of the four-dimensional twisted N = 1 super Yang-Mills theory on a Kaehler manifold by performing an appropriate dimensional reduction. We prove the existence of a 6-generator superalgebra, which does not possess any invariant Lagrangian but contains two different subalgebras that determine the twisted and untwisted formulations of the N = 1 super Yang-Mills theory. (author)

One-dimensional structures behind twisted and untwisted super Yang-Mills theory

International Nuclear Information System (INIS)

Baulieu, Laurent

2010-01-01

We give a one-dimensional interpretation of the four-dimensional twisted N = 1 super Yang-Mills theory on a Kaehler manifold by performing an appropriate dimensional reduction. We prove the existence of a 6-generator superalgebra, which does not possess any invariant Lagrangian but contains two different subalgebras that determine the twisted and untwisted formulations of the N = 1 super Yang-Mills theory. (author)

Overlap valence quarks on an twisted mass sea

Energy Technology Data Exchange (ETDEWEB)

Cichy, K. [Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Drach, V.; Garcia-Ramos, E.; Herdoiza, G.; Jansen, K. [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC

2010-12-15

We present the results of an investigation of a mixed action approach of overlap valence and maximally twisted mass sea quarks. Employing a particular matching condition on the pion mass, we analyze the continuum limit scaling of the pion decay constant and the role of chiral zero modes of the overlap operator in this process. We employ gauge field configurations generated by the European Twisted Mass Collaboration with linear lattice size L ranging from 1.3 to 1.9 fm. The continuum limit is taken at a fixed value of L=1.3 fm, employing three values of the lattice spacing and two values of the pion mass constructed from sea quarks only. (orig.)

Twisted tachyon condensation in closed string field theory

International Nuclear Information System (INIS)

Okawa, Yuji; Zwiebach, Barton

2004-01-01

We consider twisted tachyons on C/Z N orbifolds of bosonic closed string theory. It has been conjectured that these tachyonic instabilities correspond to decays of the orbifolds into flat space or into orbifolds with smaller deficit angles. We examine this conjecture using closed string field theory, with the string field truncated to low-level tachyons. We compute the tachyon potentials for C/Z 2 and C/Z 3 orbifolds and find critical points at depths that generate about 70% of the expected change in the deficit angle. We find that both twisted fields and untwisted modes localized near the apex of the cone acquire vacuum expectation values and contribute to the potential. (author)

Our experience with B.A.R.C. sup(99m)Tc generator

International Nuclear Information System (INIS)

Padmanabhan, V.; Pandurengan, N.; Lakshmanan, A.V.

1980-01-01

sup(99m)Tc has been eluted from its parent 99 Mo by solvent extraction method. It is pointed out that there is considerable variation in the eluted activity in day to day practice and any administration of the isotope to the patient must be measured in an isotope calibrator. Operator dose levels have been recorded which are quite within the permissible levels. (auth.)

Cardiac amyloidosis detection with pyrophosphate-99mTc scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Souza, D.S.F.; Ichiki, W.A.; Coura Filho, G.B.; Izaki, M.; Giorgi, M.C.P.; Soares Junior, J; Meneghetti, J.C. [Universidade de Sao Paulo (FM/USP), SP (Brazil). Fac. de Medicina. Instituto do Coracao. Servico de Medicina Nuclear e Imagem Molecular

2008-07-01

Full text: Introduction: Amyloidosis is a rare disease, characterized by extracellular deposition of insoluble amyloid fibrils in organs and tissues. It may affect virtually any system, preferably heart, kidneys and liver. The cardiac involvement produces a spectrum of clinical features, usually with progressive dysfunction. Early diagnosis is important for institution of appropriate therapy. Case report: Male patient, 75 years old, with diagnosed congestive heart failure functional class III and Mobitz II second-degree atrial-ventricular block, was hospitalized for implantation of definitive cardiac pacemaker. Patient mentioned history of worsening effort dyspnoea over a one-month period, progressing to minimum effort, orthopnea, paroxysmal nocturnal dyspnoea and paroxysms of dry cough, and swelling of lower limbs. Echocardiography showed diffuse hypertrophy of left ventricle (LV), with systolic dysfunction due to diffuse hypokinesia and hyperrefringent aspect in the septum. It was questioned a cardiac infiltrating process. Cardiac amyloidosis was considered as a diagnostic hypothesis. The patient underwent a pyrophosphate-{sup 99m}Tc scintigraphy, which showed abnormal tracer uptake in the heart projection, with diffuse pattern on the left ventricle walls, compatible with the clinical suspicion cardiac amyloidosis, which was later confirmed by endomyocardial biopsy. Discussion: In this case report, the patient had clinical and other auxiliary examinations, such as electrocardiography and Doppler echocardiography, compatible with cardiac amyloidosis, which led to implementation with pyrophosphate-{sup 99m}Tc scintigraphy and later endomyocardial biopsy. Cardiac amyloidosis occurs in about half the cases of primary amyloidosis (AL) and is rare in secondary amyloidosis (AA). Its clinical presentation is polymorphic and it can be classified into four distinctive types: restrictive cardiomyopathy, systolic dysfunction, postural hypotension and conduction disorders

Twisted Bilayer Graphene. Interlayer configuration and magnetotransport signatures

Energy Technology Data Exchange (ETDEWEB)

Rode, Johannes C.; Smirnov, Dmitri; Belke, Christopher; Schmidt, Hennrik; Haug, Rolf J. [Institut fuer Festkoerperphysik, Hannover (Germany)

2017-11-15

Twisted Bilayer Graphene may be viewed as very first representative of the now booming class of artificially layered 2D materials. Consisting of two sheets from the same structure and atomic composition, its decisive degree of freedom lies in the rotation between crystallographic axes in the individual graphene monolayers. Geometrical consideration finds angle-dependent Moire patterns as well as commensurate superlattices of opposite sublattice exchange symmetry. Beyond the approach of rigidly interposed lattices, this review takes focus on the evolving topic of lattice corrugation and distortion in response to spatially varying lattice registry. The experimental approach to twisted bilayers requires a basic control over preparation techniques; important methods are summarized and extended on in the case of bilayers folded from monolayer graphene via AFM nanomachining. Central morphological parameters to the twisted bilayer, rotational mismatch and interlayer separation are studied in a broader base of samples. Finally, experimental evidence for a number of theoretically predicted, controversial electronic scenarios are reviewed; magnetotransport signatures are discussed in terms of Fermi velocity, van Hove singularities and Berry phase and assessed with respect to the underlying experimental conditions, thereby referring back to the initially considered variations in relaxed lattice structure. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

99MTC Alpha-Fetoprotein: A Novel, Specific Agent for the Detection of Human Breast Cancer

National Research Council Canada - National Science Library

Line, Bruce

1998-01-01

.... We have demonstrated that technetium-99m radiolabeled human alpha-fetoprotein (99mTc AFP) localizes in human breast cancer cells in-vivo, most likely concentrating in breast cancer cells due to a specific receptor not found in normal adult breast tissue...

99MTC Alpha-Fetoprotein: A Novel, Specific Agent for the Detection of Human Breast Cancer

National Research Council Canada - National Science Library

Line, Bruce

1999-01-01

.... We have demonstrated that technetium-99m radiolabeled human alpha-fetoprotein (99mTc AFP) localizes in human breast cancer cells in-vivo, most likely concentrating in breast cancer cells due to a specific receptor not found in normal adult breast tissue...

Higher-twist effects in the B → π transition form factor from QCD light-cone sum rules

Energy Technology Data Exchange (ETDEWEB)

Khodjamirian, Alexander; Rusov, Aleksey [Universitaet Siegen (Germany). Fakultaet IV, Department Physik, Theoretische Physik 1 Walter-Flex-Strasse 3 57068 Siegen

2016-07-01

I report on the progress in calculating new higher-twist corrections to the QCD light-cone sum rule for the B → π transition form factor. First, the expansion of the massive heavy-quark propagator in the external gluonic field near the light-cone was extended to include new terms containing the gluon-field strength derivatives. The resulting analytical expressions for the twist-5 and twist-6 contributions to the correlation function were obtained in a factorized approximation, expressed via the product of the quark-condensate density and the lower-twist pion distribution amplitudes. The numerical analysis of new higher-twist effects is in progress.

DC conductivity of twisted bilayer graphene: Angle-dependent transport properties and effects of disorder

Science.gov (United States)

Andelković, M.; Covaci, L.; Peeters, F. M.

2018-03-01

The in-plane dc conductivity of twisted bilayer graphene is calculated using an expansion of the real-space Kubo-Bastin conductivity in terms of Chebyshev polynomials. We investigate within a tight-binding approach the transport properties as a function of rotation angle, applied perpendicular electric field, and vacancy disorder. We find that for high-angle twists, the two layers are effectively decoupled, and the minimum conductivity at the Dirac point corresponds to double the value observed in monolayer graphene. This remains valid even in the presence of vacancies, hinting that chiral symmetry is still preserved. On the contrary, for low twist angles, the conductivity at the Dirac point depends on the twist angle and is not protected in the presence of disorder. Furthermore, for low angles and in the presence of an applied electric field, we find that the chiral boundary states emerging between AB and BA regions contribute to the dc conductivity, despite the appearance of localized states in the AA regions. The results agree qualitatively with recent transport experiments in low-angle twisted bilayer graphene.

Note on twisted elliptic genus of K3 surface

Energy Technology Data Exchange (ETDEWEB)

Eguchi, Tohru, E-mail: eguchi@yukawa.kyoto-u.ac.j [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Hikami, Kazuhiro, E-mail: KHikami@gmail.co [Department of Mathematics, Naruto University of Education, Tokushima 772-8502 (Japan)

2011-01-03

We discuss the possibility of Mathieu group M{sub 24} acting as symmetry group on the K3 elliptic genus as proposed recently by Ooguri, Tachikawa and one of the present authors. One way of testing this proposal is to derive the twisted elliptic genera for all conjugacy classes of M{sub 24} so that we can determine the unique decomposition of expansion coefficients of K3 elliptic genus into irreducible representations of M{sub 24}. In this Letter we obtain all the hitherto unknown twisted elliptic genera and find a strong evidence of Mathieu moonshine.

Radionuclide study of thyroid function in pediatrics, using sup(99m)Tc, 123I or 131I: 150 case-reports

International Nuclear Information System (INIS)

Guillet, J.; Basse-Cathalinat, B.; Soubiran, G.; Blanquet, P.; Guillet, G.

1981-01-01

THe best radioisotope for in vivo thyroid investigations is the one which provides the highest quality scintigrams with the least radiation exposure. The choice of 131 I, 123 I or sup(99m)Tc in 150 children is discussed. Cases included 25 dysgenesis, 4 goiters with hypothyroidism, 56 goiters without thyroid dysfunction, 3 thyroiditis, and 11 cold nodules. When thyroid scanning is performed with 131 I, the gland's radiation exposure is high. 123 I is preferable since a fairly high activity can be obtained without delivering an excessive radiation dose. (approximately 2 rad to the thyroid for 50 microCi/m 2 ). sup(99m)Tc which is readily available is not a true iodine analog. It does not give a true picture of iodine metabolism. 123 I was generally used in cases of hypothyroidism, goiter (whenever a defect in thyroid hormone synthesis was suspected) and hyperthyroidism. sup(99m)Tc was generally used in other cases. The low radiation doses delivered by these radioisotopes allows study of thyroid function in the neonate [fr

Families of vector-like deformations of relativistic quantum phase spaces, twists and symmetries

Energy Technology Data Exchange (ETDEWEB)

Meljanac, Daniel [Ruder Boskovic Institute, Division of Materials Physics, Zagreb (Croatia); Meljanac, Stjepan; Pikutic, Danijel [Ruder Boskovic Institute, Division of Theoretical Physics, Zagreb (Croatia)

2017-12-15

Families of vector-like deformed relativistic quantum phase spaces and corresponding realizations are analyzed. A method for a general construction of the star product is presented. The corresponding twist, expressed in terms of phase space coordinates, in the Hopf algebroid sense is presented. General linear realizations are considered and corresponding twists, in terms of momenta and Poincare-Weyl generators or gl(n) generators are constructed and R-matrix is discussed. A classification of linear realizations leading to vector-like deformed phase spaces is given. There are three types of spaces: (i) commutative spaces, (ii) κ-Minkowski spaces and (iii) κ-Snyder spaces. The corresponding star products are (i) associative and commutative (but non-local), (ii) associative and non-commutative and (iii) non-associative and non-commutative, respectively. Twisted symmetry algebras are considered. Transposed twists and left-right dual algebras are presented. Finally, some physical applications are discussed. (orig.)

Families of vector-like deformations of relativistic quantum phase spaces, twists and symmetries

International Nuclear Information System (INIS)

Meljanac, Daniel; Meljanac, Stjepan; Pikutic, Danijel

2017-01-01

Families of vector-like deformed relativistic quantum phase spaces and corresponding realizations are analyzed. A method for a general construction of the star product is presented. The corresponding twist, expressed in terms of phase space coordinates, in the Hopf algebroid sense is presented. General linear realizations are considered and corresponding twists, in terms of momenta and Poincare-Weyl generators or gl(n) generators are constructed and R-matrix is discussed. A classification of linear realizations leading to vector-like deformed phase spaces is given. There are three types of spaces: (i) commutative spaces, (ii) κ-Minkowski spaces and (iii) κ-Snyder spaces. The corresponding star products are (i) associative and commutative (but non-local), (ii) associative and non-commutative and (iii) non-associative and non-commutative, respectively. Twisted symmetry algebras are considered. Transposed twists and left-right dual algebras are presented. Finally, some physical applications are discussed. (orig.)

Families of vector-like deformations of relativistic quantum phase spaces, twists and symmetries

Science.gov (United States)

Meljanac, Daniel; Meljanac, Stjepan; Pikutić, Danijel

2017-12-01

Families of vector-like deformed relativistic quantum phase spaces and corresponding realizations are analyzed. A method for a general construction of the star product is presented. The corresponding twist, expressed in terms of phase space coordinates, in the Hopf algebroid sense is presented. General linear realizations are considered and corresponding twists, in terms of momenta and Poincaré-Weyl generators or gl(n) generators are constructed and R-matrix is discussed. A classification of linear realizations leading to vector-like deformed phase spaces is given. There are three types of spaces: (i) commutative spaces, (ii) κ -Minkowski spaces and (iii) κ -Snyder spaces. The corresponding star products are (i) associative and commutative (but non-local), (ii) associative and non-commutative and (iii) non-associative and non-commutative, respectively. Twisted symmetry algebras are considered. Transposed twists and left-right dual algebras are presented. Finally, some physical applications are discussed.

Balloon-based adjuvant radiotherapy in breast cancer: comparison between {sup 99m}Tc and HDR {sup 192}Ir

Energy Technology Data Exchange (ETDEWEB)

Campos, Tarcisio Passos Ribeiro de; Lima, Carla Flavia de; Cuperschmid, Ethel Mizrahy, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

2016-03-15

Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with {sup 99m}Tc and balloon brachytherapy with high-dose-rate (HDR) {sup 192}Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and methods: simulations of implants with {sup 99m}Tc-filled and HDR {sup 192}Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: the {sup 99m}Tc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h{sup -1}.mCi{sup -1} and 0.190 cGyh{sup -1} at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh{sup -1}.mCi{sup -1}, respectively, for the HDR {sup 192}Ir balloon. An exposure time of 24 hours was required for the {sup 99m}Tc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR {sup 192}Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: temporary {sup 99m}Tc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR {sup 192}Ir balloon implantation, which is the current standard in clinical practice. (author)

The accumulation, retention and distribution of {sup 95m}Tc in crab (Cancer pagurus L.) and lobster (Homarus gammarus L.). A comparative study

Energy Technology Data Exchange (ETDEWEB)

Smith, D L; Knowles, J F; Winpenny, K [The Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk (United Kingdom)

1988-08-01

The accumulation, retention and distribution of {sup 95m}Tc has been compared in lobsters and edible crabs kept under identical experimental conditions. The steady-state concentration factor (C{sub ss}) for the uptake of {sup 95m}Tc from seawater was significantly greater for female crabs (C{sub ss}=17{center_dot}9) than for males (C{sub ss}=14{center_dot}4), whereas in lobsters there was no such sex difference and the C{sub ss} of 1161 was much greater than in crabs. The uptake of technetium from food (as indicated by whole body counts) was only moderately greater in lobsters than crabs. Retention of {sup 95m}Tc was similar for crabs and lobsters of both sexes but the clearance rate was greater after the nuclide had been taken up from seawater (t{sub b1/2}=51 days) than from food (t{sub b1/2}=108 days). In all crabs and most male lobsters {sup 95m}Tc was predominantly in the hepatopancreas while in a few male and all female lobsters it was mainly in muscle. Lobster ovaries consistently contained more activity than testes but this difference was not seen in crabs. In hepatopancreas cells of both species {sup 95m}Tc occurred mainly in the cytosol and some initial steps were taken to determine the relationship between technetium and cytosol proteins. The results for crab and lobster are compared with those from previous studies on these and other crustacean species. The possible basis for the much higher concentrations of technetium in lobsters than crabs is discussed and further research suggested. (Copyright (c) 1988 Elsevier Science B.V., Amsterdam. All rights reserved.)

Chiral tunneling in a twisted graphene bilayer.

Science.gov (United States)

He, Wen-Yu; Chu, Zhao-Dong; He, Lin

2013-08-09

The perfect transmission in a graphene monolayer and the perfect reflection in a Bernal graphene bilayer for electrons incident in the normal direction of a potential barrier are viewed as two incarnations of the Klein paradox. Here we show a new and unique incarnation of the Klein paradox. Owing to the different chiralities of the quasiparticles involved, the chiral fermions in a twisted graphene bilayer show an adjustable probability of chiral tunneling for normal incidence: they can be changed from perfect tunneling to partial or perfect reflection, or vice versa, by controlling either the height of the barrier or the incident energy. As well as addressing basic physics about how the chiral fermions with different chiralities tunnel through a barrier, our results provide a facile route to tune the electronic properties of the twisted graphene bilayer.

Vacuum fluctuations of twisted fields in the space time of cosmic strings

International Nuclear Information System (INIS)

Matsas, G.E.A.

1990-01-01

A twisted scalar field conformally coupled to gravitation is used to calculate the vacuum stress-energy tensor in the background spacetime generated by an infinite straight gauge cosmic string. The result has an absolute numerical value close to the one obtained with a non-twisted conformal scalar field but their signals are opposite. (author) [pt

TiO2/water Nanofluid Heat Transfer in Heat Exchanger Equipped with Double Twisted-Tape Inserts

Science.gov (United States)

Eiamsa-ard, S.; Ketrain, R.; Chuwattanakul, V.

2018-05-01

Nowadays, heat transfer enhancement plays an important role in improving efficiency of heat transfer and thermal systems for numerous areas such as heat recovery processes, chemical reactors, air-conditioning/refrigeration system, food engineering, solar air/water heater, cooling of high power electronics etc. The present work presents the experimental results of the heat transfer enhancement of TiO2/water nanofluid in a heat exchanger tube fitted with double twisted tapes. The study covered twist ratios of twisted tapes (y/w) of 1.5, 2.0, and 2.5) while the concentration of the nanofluid was kept constant at 0.05% by volume. Observations show that heat transfer, friction loss and thermal performance increase as twist ratio (y/w) decreases. The use of the nanofluid in the tube equipped with the double twisted-tapes with the smallest twist ratio (y/w = 1.5) results in the increases of heat transfer rates and friction factor up to 224.8% and 8.98 times, respectively as compared to those of water. In addition, the experimental results performed that double twisted tapes induced dual swirling-flows which played an important role in improving fluid mixing and heat transfer enhancement. It is also observed that the TiO2/water nanofluid was responsible for low pressure loss behaviors.

The final measurements of the muon decay parameters from the TWIST experiment

International Nuclear Information System (INIS)

Bayes, R

2013-01-01

The TWIST (TRIUMF Weak Interaction Symmetry Test) experiment probes the Lorentz structure of the weak interaction using muon decay. This structure has a very well defined form under the Standard Model (SM) which makes precise predictions for the shape of the decay positron spectrum with respect to momentum and angle. The shape of the spectrum may be described under some rather general assumptions using a set of decay parameters whose values according to the SM are ρ = δ = 3/4, η = 0, and ξ = 1. TWIST uses a large sample of muon decays in a large acceptance spectrometer to measure the decay parameters to an order of magnitude greater precision than previous measurements. This experiment saw its last year of data collection in 2007. As TWIST is a systematics dominated experiment, much effort has been spent on refinements of the estimates of the systematic uncertainties over previous TWIST results. These proceedings will discuss the measures taken to achieve the precision goal of parts in 10 4 , and the physics implications of the experiment.

Synthesis and structural determination of twisted MoS2 nanotubes

International Nuclear Information System (INIS)

Santiago, P.; Schabes-Retchkiman, P.; Ascencio, J.A.; Mendoza, D.; Perez-Alvarez, M.; Espinosa, A.; Reza-SanGerman, C.; Camacho-Bragado, G.A.; Jose-Yacaman, M.

2004-01-01

In the present work we report the synthesis of MoS 2 nanotubes with diameters greater than 10 nm using a template method. The length and properties of these nanotubes are a direct result of the preparation method. High-resolution transmission electron microscopy is used to study the structure of these highly curved entities. Molecular dynamics simulations of MoS 2 nanotubes reveal that one of the stable forms of the nanotubes is a twisted one. The twisting of the nanotubes produces a characteristic contrast in the images, which is also studied using simulation methods. The analysis of the local contrast close to the perpendicular orientation shows geometrical arrays of dots in domain-like structures, which are demonstrated to be a product of the atomic overlapping of irregular curvatures in the nanotubes. The configuration of some of the experimentally obtained nanotubes is demonstrated to be twisted with a behavior suggesting partial plasticity. (orig.)

WE-AB-204-12: Dosimetry at the Sub-Cellular Scale of Auger-Electron Emitter 99m-Tc in a Mouse Single Thyroid Follicle Model

Energy Technology Data Exchange (ETDEWEB)

Taborda, A; Benabdallah, N; Desbree, A [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-roses (France)

2015-06-15

Purpose: To perform a dosimetry study at the sub-cellular scale of Auger-electron emitter 99m-Tc using a mouse single thyroid cellular model to investigate the contribution of the 99m-Tc Auger-electrons to the absorbed dose and possible link to the thyroid stunning in in vivo experiments in mice, recently reported in literature. Methods: The simulation of S-values for Auger-electron emitting radionuclides was performed using both the recent MCNP6 software and the Geant4-DNA extension of the Geant4 toolkit. The dosimetric calculations were validated through comparison with results from literature, using a simple model of a single cell consisting of two concentric spheres of unit density water and for six Auger-electron emitting radionuclides. Furthermore, the S-values were calculated using a single thyroid follicle model for uniformly distributed 123-I and 125-I radionuclides and compared with published S-values. After validation, the simulation of the S-values was performed for the 99m-Tc radionuclide within the several mouse thyroid follicle cellular compartments, considering the radiative and non-radiative transitions of the 99m-Tc radiation spectrum. Results: The calculated S-values using MCNP6 are in good agreement with the results from literature, validating its use for the 99m-Tc S-values calculations. The most significant absorbed dose corresponds to the case where the radionuclide is uniformly distributed in the follicular cell’s nucleus, with a S-value of 7.8 mGy/disintegration, due mainly to the absorbed Auger-electrons. The results show that, at a sub-cellular scale, the emitted X-rays and gamma particles do not contribute significantly to the absorbed dose. Conclusion: In this work, MCNP6 was validated for dosimetric studies at the sub-cellular scale. It was shown that the contribution of the Auger-electrons to the absorbed dose is important at this scale compared to the emitted photons’ contribution and can’t be neglected. The obtained S

Production optimization of {sup 99}Mo/{sup 99m}Tc zirconium molybate gel generators at semi-automatic device: DISIGEG

Energy Technology Data Exchange (ETDEWEB)

Monroy-Guzman, F., E-mail: fabiola.monroy@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Rivero Gutierrez, T., E-mail: tonatiuh.rivero@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Lopez Malpica, I.Z.; Hernandez Cortes, S.; Rojas Nava, P.; Vazquez Maldonado, J.C. [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Vazquez, A. [Instituto Mexicano del Petroleo, Eje Central Norte Lazaro Cardenas 152, Col. San Bartolo Atepehuacan, 07730, Mexico D.F. (Mexico)

2012-01-15

DISIGEG is a synthesis installation of zirconium {sup 99}Mo-molybdate gels for {sup 99}Mo/{sup 99m}Tc generator production, which has been designed, built and installed at the ININ. The device consists of a synthesis reactor and five systems controlled via keyboard: (1) raw material access, (2) chemical air stirring, (3) gel dried by air and infrared heating, (4) moisture removal and (5) gel extraction. DISIGEG operation is described and dried condition effects of zirconium {sup 99}Mo- molybdate gels on {sup 99}Mo/{sup 99m}Tc generator performance were evaluated as well as some physical-chemical properties of these gels. The results reveal that temperature, time and air flow applied during the drying process directly affects zirconium {sup 99}Mo-molybdate gel generator performance. All gels prepared have a similar chemical structure probably constituted by three-dimensional network, based on zirconium pentagonal bipyramids and molybdenum octahedral. Basic structural variations cause a change in gel porosity and permeability, favouring or inhibiting {sup 99m}TcO{sub 4}{sup -} diffusion into the matrix. The {sup 99m}TcO{sub 4}{sup -} eluates produced by {sup 99}Mo/{sup 99m}Tc zirconium {sup 99}Mo-molybdate gel generators prepared in DISIGEG, air dried at 80 Degree-Sign C for 5 h and using an air flow of 90 mm, satisfied all the Pharmacopoeias regulations: {sup 99m}Tc yield between 70-75%, {sup 99}Mo breakthrough less than 3 Multiplication-Sign 10{sup -3}%, radiochemical purities about 97% sterile and pyrogen-free eluates with a pH of 6. - Highlights: Black-Right-Pointing-Pointer {sup 99}Mo/{sup 99m}Tc generators based on {sup 99}Mo-molybdate gels were synthesized at a semi-automatic device. Black-Right-Pointing-Pointer Generator performances depend on synthesis conditions of the zirconium {sup 99}Mo-molybdate gel. Black-Right-Pointing-Pointer {sup 99m}TcO{sub 4}{sup -} diffusion and yield into generator depends on gel porosity and permeability. Black

Output Feedback Control of Electro-Hydraulic Cylinder Drives using the Twisting Algorithm

DEFF Research Database (Denmark)

Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.

2014-01-01

contributions in literature. This paper considers the twisting algorithm when applied directly for output feedback control, and with the design based on a reduced order model representation of an arbitrary valve driven hydraulic cylinder drive. The consequence of implementing such a controller with the well......This paper discusses the utilization of the so-called twisting algorithm when applied in output feedback position control schemes for electro-hydraulic cylinder drives. The twisting controller was the first second order sliding controller ever introduced, and can structure-wise be considered...... feedback controller may be successfully applied to hydraulic valve driven cylinder drives, with performance being on the level with a conventional surface based first order sliding mode controller....

Analysis of Twisting of Cellulose Nanofibrils in Atomistic Molecular Dynamics Simulations

DEFF Research Database (Denmark)

Paavilainen, S.; Rog, T.; Vattulainen, I.

2011-01-01

We use atomistic molecular dynamics simulations to study the crystal structure of cellulose nanofibrils, whose sizes are comparable with the crystalline parts in commercial nanocellulose. The simulations show twisting, whose rate of relaxation is strongly temperature dependent. Meanwhile......, no significant bending or stretching of nanocellulose is discovered. Considerations of atomic-scale interaction patterns bring about that the twisting arises from hydrogen bonding within and between the chains in a fibril....

Tilting-Twisting-Rolling: a pen-based technique for compass geometric construction

Institute of Scientific and Technical Information of China (English)

Fei LYU; Feng TIAN; Guozhong DAI; Hongan WANG

2017-01-01

This paper presents a new pen-based technique,Tilting-Twisting-Rolling,to support compass geometric construction.By leveraging the 3D orientation information and 3D rotation information of a pen,this technique allows smooth pen action to complete multi-step geometric construction without switching task states.Results from a user study show this Tilting-Twisting-Rolling technique can improve user performance and user experience in compass geometric construction.

Impact of higher twist terms on the analysis of scaling violation

International Nuclear Information System (INIS)

Barnett, R.M.

1979-09-01

A critical discussion is given of analyses of scaling violation in deep-inelastic scattering in the context of QCD. Several possible approaches are examined. Higher twist contributions are defined, and it is shown that they can have a crucial impact on tests of QCD. Higher twist terms can dramatically affect R = sigma/sub L//sigma/sub T/. QCD may be harder to test than previously realized. 17 references

CytometryML: a data standard which has been designed to interface with other standards

Science.gov (United States)

Leif, Robert C.

2007-02-01

Because of the differences in the requirements, needs, and past histories including existing standards of the creating organizations, a single encompassing cytology-pathology standard will not, in the near future, replace the multiple existing or under development standards. Except for DICOM and FCS, these standardization efforts are all based on XML. CytometryML is a collection of XML schemas, which are based on the Digital Imaging and Communications in Medicine (DICOM) and Flow Cytometry Standard (FCS) datatypes. The CytometryML schemas contain attributes that link them to the DICOM standard and FCS. Interoperability with DICOM has been facilitated by, wherever reasonable, limiting the difference between CytometryML and the previous standards to syntax. In order to permit the Resource Description Framework, RDF, to reference the CytometryML datatypes, id attributes have been added to many CytometryML elements. The Laboratory Digital Imaging Project (LDIP) Data Exchange Specification and the Flowcyt standards development effort employ RDF syntax. Documentation from DICOM has been reused in CytometryML. The unity of analytical cytology was demonstrated by deriving a microscope type and a flow cytometer type from a generic cytometry instrument type. The feasibility of incorporating the Flowcyt gating schemas into CytometryML has been demonstrated. CytometryML is being extended to include many of the new DICOM Working Group 26 datatypes, which describe patients, specimens, and analytes. In situations where multiple standards are being created, interoperability can be facilitated by employing datatypes based on a common set of semantics and building in links to standards that employ different syntax.

Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †

Science.gov (United States)

Budinski, Vedran; Donlagic, Denis

2017-01-01

Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation. PMID:28241510

Bogoliubov coefficients for the twist operator in the D1D5 CFT

Directory of Open Access Journals (Sweden)

Zaq Carson

2014-12-01

Full Text Available The D1D5 CFT is a holographic dual of a near-extremal black hole in string theory. The interaction in this theory involves a twist operator which joins together different copies of a free CFT. Given a large number of D1 and D5 branes, the effective length of the circle on which the CFT lives is very large. We develop a technique to study the effect of the twist operator in the limit where the wavelengths of excitations are short compared to this effective length, which we call the ‘continuum limit’. The method uses Bogoliubov coefficients to compute the effect of the twist operator in this limit. For bosonic fields, we use the method to reproduce recent results describing the effect of the twist operator when it links together CFT copies with windings M and N, producing a copy of winding M+N. We also comment on possible generalizations of our results. The methods developed here may help in understanding the twist interaction at higher orders. This in turn should provide insight into the thermalization process in the D1D5 CFT, which gives a holographic description of black hole formation.

Twisted mass lattice QCD

International Nuclear Information System (INIS)

Shindler, A.

2007-07-01

I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the effects of these discretization errors on the phase structure for Wilson-like fermions in the chiral limit. The possibility to use in lattice simulations different lattice actions for sea and valence quarks to ease the renormalization patterns of phenomenologically relevant local operators, is also discussed. (orig.)

Twisted mass lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Shindler, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

2007-07-15

I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the effects of these discretization errors on the phase structure for Wilson-like fermions in the chiral limit. The possibility to use in lattice simulations different lattice actions for sea and valence quarks to ease the renormalization patterns of phenomenologically relevant local operators, is also discussed. (orig.)

Massive Machine-Type Communication (mMTC) Access with Integrated Authentication

DEFF Research Database (Denmark)

Pratas, Nuno; Pattathil, Sarath; Stefanovic, Cedomir

2017-01-01

We present a connection establishment protocol with integrated authentication, suited for Massive Machine-Type Communications (mMTC). The protocol is contention-based and its main feature is that a device contends with a unique signature that also enables the authentication of the device towards...... the network. The signatures are inspired by Bloom filters and are created based on the output of the MILENAGE authentication and encryption algorithm set, which is used in the authentication and security procedures in the LTE protocol family.We show that our method utilizes the system resources more...

Modeling higher twist contributions to deep inelastic scattering with diquarks

International Nuclear Information System (INIS)

Anselmino, M.

1994-01-01

The most recent detailed data on the unpolarized nucleon structure functions allow a precise determination of higher twist contributions. Quark-quark correlations induced by color forces are expected to be a natural explanation for such effects; indeed, a quark-diquark picture of the nucleon, previously introduced in the description of several exclusive processes at intermediate Q 2 values, is found to model the proton higher twist data with great accuracy. The resulting parameters are consistent with the diquark properties suggested by other experimental and theoretical analyses. (author)

Measurement of lipid accumulation in Chlorella vulgaris via flow cytometry and liquid-state ¹H NMR spectroscopy for development of an NMR-traceable flow cytometry protocol.

Directory of Open Access Journals (Sweden)

Michael S Bono

Full Text Available In this study, we cultured Chlorella vulgaris cells with a range of lipid contents, induced via nitrogen starvation, and characterized them via flow cytometry, with BODIPY 505/515 as a fluorescent lipid label, and liquid-state 1H NMR spectroscopy. In doing so, we demonstrate the utility of calibrating flow cytometric measurements of algal lipid content using triacylglyceride (TAG, also known as triacylglycerol or triglyceride content per cell as measured via quantitative 1H NMR. Ensemble-averaged fluorescence of BODIPY-labeled cells was highly correlated with average TAG content per cell measured by bulk NMR, with a linear regression yielding a linear fit with r2 = 0.9974. This correlation compares favorably to previous calibrations of flow cytometry protocols to lipid content measured via extraction, and calibration by NMR avoids the time and complexity that is generally required for lipid quantitation via extraction. Flow cytometry calibrated to a direct measurement of TAG content can be used to investigate the distribution of lipid contents for cells within a culture. Our flow cytometry measurements showed that Chlorella vulgaris cells subjected to nitrogen limitation exhibited higher mean lipid content but a wider distribution of lipid content that overlapped the relatively narrow distribution of lipid content for replete cells, suggesting that nitrogen limitation induces lipid accumulation in only a subset of cells. Calibration of flow cytometry protocols using direct in situ measurement of TAG content via NMR will facilitate rapid development of more precise flow cytometry protocols, enabling investigation of algal lipid accumulation for development of more productive algal biofuel feedstocks and cultivation protocols.

Measurement of Lipid Accumulation in Chlorella vulgaris via Flow Cytometry and Liquid-State ¹H NMR Spectroscopy for Development of an NMR-Traceable Flow Cytometry Protocol

Science.gov (United States)

Bono Jr., Michael S.; Garcia, Ravi D.; Sri-Jayantha, Dylan V.; Ahner, Beth A.; Kirby, Brian J.

2015-01-01

In this study, we cultured Chlorella vulgaris cells with a range of lipid contents, induced via nitrogen starvation, and characterized them via flow cytometry, with BODIPY 505/515 as a fluorescent lipid label, and liquid-state 1H NMR spectroscopy. In doing so, we demonstrate the utility of calibrating flow cytometric measurements of algal lipid content using triacylglyceride (TAG, also known as triacylglycerol or triglyceride) content per cell as measured via quantitative 1H NMR. Ensemble-averaged fluorescence of BODIPY-labeled cells was highly correlated with average TAG content per cell measured by bulk NMR, with a linear regression yielding a linear fit with r 2 = 0.9974. This correlation compares favorably to previous calibrations of flow cytometry protocols to lipid content measured via extraction, and calibration by NMR avoids the time and complexity that is generally required for lipid quantitation via extraction. Flow cytometry calibrated to a direct measurement of TAG content can be used to investigate the distribution of lipid contents for cells within a culture. Our flow cytometry measurements showed that Chlorella vulgaris cells subjected to nitrogen limitation exhibited higher mean lipid content but a wider distribution of lipid content that overlapped the relatively narrow distribution of lipid content for replete cells, suggesting that nitrogen limitation induces lipid accumulation in only a subset of cells. Calibration of flow cytometry protocols using direct in situ measurement of TAG content via NMR will facilitate rapid development of more precise flow cytometry protocols, enabling investigation of algal lipid accumulation for development of more productive algal biofuel feedstocks and cultivation protocols. PMID:26267664

Measurement of lipid accumulation in Chlorella vulgaris via flow cytometry and liquid-state ¹H NMR spectroscopy for development of an NMR-traceable flow cytometry protocol.

Science.gov (United States)

Bono, Michael S; Garcia, Ravi D; Sri-Jayantha, Dylan V; Ahner, Beth A; Kirby, Brian J

2015-01-01

In this study, we cultured Chlorella vulgaris cells with a range of lipid contents, induced via nitrogen starvation, and characterized them via flow cytometry, with BODIPY 505/515 as a fluorescent lipid label, and liquid-state 1H NMR spectroscopy. In doing so, we demonstrate the utility of calibrating flow cytometric measurements of algal lipid content using triacylglyceride (TAG, also known as triacylglycerol or triglyceride) content per cell as measured via quantitative 1H NMR. Ensemble-averaged fluorescence of BODIPY-labeled cells was highly correlated with average TAG content per cell measured by bulk NMR, with a linear regression yielding a linear fit with r2 = 0.9974. This correlation compares favorably to previous calibrations of flow cytometry protocols to lipid content measured via extraction, and calibration by NMR avoids the time and complexity that is generally required for lipid quantitation via extraction. Flow cytometry calibrated to a direct measurement of TAG content can be used to investigate the distribution of lipid contents for cells within a culture. Our flow cytometry measurements showed that Chlorella vulgaris cells subjected to nitrogen limitation exhibited higher mean lipid content but a wider distribution of lipid content that overlapped the relatively narrow distribution of lipid content for replete cells, suggesting that nitrogen limitation induces lipid accumulation in only a subset of cells. Calibration of flow cytometry protocols using direct in situ measurement of TAG content via NMR will facilitate rapid development of more precise flow cytometry protocols, enabling investigation of algal lipid accumulation for development of more productive algal biofuel feedstocks and cultivation protocols.

An empirically-based model for the lift coefficients of twisted airfoils with leading-edge tubercles

Science.gov (United States)

Ni, Zao; Su, Tsung-chow; Dhanak, Manhar

2018-04-01

Experimental data for untwisted airfoils are utilized to propose a model for predicting the lift coefficients of twisted airfoils with leading-edge tubercles. The effectiveness of the empirical model is verified through comparison with results of a corresponding computational fluid-dynamic (CFD) study. The CFD study is carried out for both twisted and untwisted airfoils with tubercles, the latter shown to compare well with available experimental data. Lift coefficients of twisted airfoils predicted from the proposed empirically-based model match well with the corresponding coefficients determined using the verified CFD study. Flow details obtained from the latter provide better insight into the underlying mechanism and behavior at stall of twisted airfoils with leading edge tubercles.

A torsional artificial muscle from twisted nitinol microwire

Science.gov (United States)

Mirvakili, Seyed M.; Hunter, Ian W.

2017-04-01

Nitinol microwires of 25 μm in diameter can have tensile actuation of up to 4.5% in less than 100 ms. A work density of up to 480 MPa can be achieved from these microwires. In the present work, we are showing that by twisting the microwires in form of closed-loop two-ply yarn we can create a torsional actuator. We achieved a revisable torsional stroke of 46°/mm with peak rotational speed of up to 10,000 rpm. We measured a gravimetric torque of up to 28.5 N•m/kg which is higher than the 3 - 6 N•m/kg for direct-drive commercial electric motors. These remarkable performance results are comparable to those of guest-infiltrated carbon nanotube twisted yarns.

Effect of Lowering Twist Levels on Quality Parameters of Rotor Spun Cotton Yarn

Directory of Open Access Journals (Sweden)

FAROOQ AHMED

2016-07-01

Full Text Available Investigations were made to explore the influence of lowering twist level on quality characteristics of rotor spun yarn. Three levels of yarn linear density (i.e. 40, 35 and 30 tex and five levels of twist (i.e. 700, 600, 550, 500, and 450 were employed during yarn spinning trials. Each twist multiple was investigated at all linear densities for tensile strength, elongation, total CVm (Coefficient of Mass Variation imperfection index and hairiness. 100% cotton yarn samples were prepared on Reiter R-40 at rotor speed of 90,000 rpm. Determination of elongation, yarn strength, hairiness, mass variation, and total imperfections index was carried out on Uster Tensorapid-4 and Uster Tester-4 as per set standards of ISO standard test methods. Based on investigations it is established that yarn strength and elongation declined minutely (Insignificant with lowering twist levels but still can be confidently used for knitting yarns. However, significant improvement in total imperfection index and marginal enhancement in CVm were experienced.

Comparison of film sensitivity for sup(99m)Tc gamma-rays

International Nuclear Information System (INIS)

Kojima, Kazuhiko; Katayama, Masaharu; Hisada, Kinichi.

1975-01-01

Recently a new method of γ-ray imaging by holography has been studied at several nuclear medical laboratories. The holography is of a very simple. An axis Fresnel zone plate made of lead (2 mm thickness) is placed between the γ-ray source and a detector, and its shadow is recorded as a hologram. The hologram obtained is illuminated by parallel beams of He-Ne laser (6328 A), and an image of the radioisotope distribution in the object is reconstructed by diffraction. The better the resolution of the shadow hologram, the better are the reconstructed images obtained. For this reason the detector for recording the γ-ray hologram must be selected carefully. Three kinds of medical X-ray film were used as detectors for holograms to compare film sensitivity. Generally these medical X-ray films have poor sensitivity to γ-rays of sup(99m)Tc. In order to intensify the film sensitivity for γ-rays of sup(99m)Tc, combinations of six kinds of intensifying screens were studied. Good film sensitivity was obtained by RP (Kodak Co.) film combined with a KZ-S fluorescent intensifying screen. The fluorescent screen was better than fluorometallic screens with similar properties. Using this film-screen combination, shadow holograms could be recorded for 2-3 minutes and images could be optically reconstructed. (auth.)

Closing Gaps in Geometrically Frustrated Symmetric Clusters: Local Equivalence between Discrete Curvature and Twist Transformations

Directory of Open Access Journals (Sweden)

Fang Fang

2018-05-01

Full Text Available In geometrically frustrated clusters of polyhedra, gaps between faces can be closed without distorting the polyhedra by the long established method of discrete curvature, which consists of curving the space into a fourth dimension, resulting in a dihedral angle at the joint between polyhedra in 4D. An alternative method—the twist method—has been recently suggested for a particular case, whereby the gaps are closed by twisting the cluster in 3D, resulting in an angular offset of the faces at the joint between adjacent polyhedral. In this paper, we show the general applicability of the twist method, for local clusters, and present the surprising result that both the required angle of the twist transformation and the consequent angle at the joint are the same, respectively, as the angle of bending to 4D in the discrete curvature and its resulting dihedral angle. The twist is therefore not only isomorphic, but isogonic (in terms of the rotation angles to discrete curvature. Our results apply to local clusters, but in the discussion we offer some justification for the conjecture that the isomorphism between twist and discrete curvature can be extended globally. Furthermore, we present examples for tetrahedral clusters with three-, four-, and fivefold symmetry.

Studying apoptotic cell death by flow cytometry

International Nuclear Information System (INIS)

Ormerod, Michael G.

1998-01-01

Full text: Programmed cell death (PCD) is of fundamental importance in the normal development of an animal and also in tumour biology and radiation biology. During PCD a sequence of changes occurs in cells giving rise to an apoptotic cascade of events. The main elements of this cascade are rapidly being elucidated. Flow cytometry has been used to follow many of these changes. It also has been used to quantify the number of apoptotic cells in a culture and, more recently, in clinical samples. In this review, the properties of apoptotic cells and the main feature of apoptotic cascade will be described. How flow cytometry can be used to follow changes during the apoptotic cascade will be discussed

Effects of Momordica charantia on osmotic fragility and label red blood cells and plasmatic protein with 99m-Tc in vitro

Energy Technology Data Exchange (ETDEWEB)

Magnata, Simey S.L.P. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear]. E-mail: sfmagnata@terra.com.br; Correia, Marilia B.L.; Brandao, Jose Odinilson C.; Souza, Grace M.L.; Catanho, Maria Teresa J.A. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia; Terra, Daniele A.; Amorim, Lucia F. [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Fisiologia

2005-07-01

The use of natural products in the treatment physiopathology awaken the interest in the inquiry of the action mechanisms. The Momordica charantia, Melao de Sao Caetano, is used in the Caribbean and Orient for the diseases as stomatitis, cancer and diabetes. This work aims to verify the effect of the Momordica charantia's aqueous extract leaves on osmotic fragility and on labeling red blood cells (RBC) and plasmatic proteins with {sup 99m}Tc in vitro. To evaluate the osmotic fragility, samples of heparinized blood (500 mL) was incubed for 1 hour with brut extract (500 mL) in different concentrations (0; 10; 50 and 100% v/v); after centrifugation, the RCB were submitted the incubation (1 hour) with a gradient of NaCl (0;0,1;0,25;0,4;0,7 and 0.9%), the OD of supernatant was determined. With regards to label red blood cells and plasmatic proteins with {sup 99m}Tc in vitro was carried out by incubating of anticoagulant whole blood (500 mL) for 1 hour with brut extract (500 mL) in different concentrations (0; 10; 50 and 100% v/v). A stannous chloride solution of 1,2 {mu}g/mL was added the incubation for 60 minutes. After this the {sup 99m}Tc (3,7 MBq) was added and the incubation was continued for another 10 minutes. Those were centrifuged, precipitated with trichloroacetic acid 5% and mensured in a counter. The results shows that with regard to osmotic fragility, only the extract in the concentration of 100% provoked hemolysis. The Momordica charantia's extract is an agent who modify the fixation of {sup 99m}Tc in red blood cells. The results show with regard to osmotic fragility, only the extract in the quantity 100% provoked hemolysis. It is concluded that the Momordica charantia's extract is an agent who unchains the cellular fragility and {sup 99m}Tc fixation, showing a reduction effect. (author)

How the embryonic brain tube twists

Science.gov (United States)

Chen, Zi; Guo, Qiaohang; Forsch, Nickolas; Taber, Larry

2014-03-01

During early development, the tubular brain of the chick embryo undergoes a combination of progressive ventral bending and rightward torsion. This deformation is one of the major organ-level symmetry-breaking events in development. Available evidence suggests that bending is caused by differential growth, but the mechanism for torsion remains poorly understood. Since the heart almost always loops in the same direction that the brain twists, researchers have speculated that heart looping affects the direction of brain torsion. However, direct evidence is virtually nonexistent, nor is the mechanical origin of such torsion understood. In our study, experimental perturbations show that the bending and torsional deformations in the brain are coupled and that the vitelline membrane applies an external load necessary for torsion to occur. In addition, the asymmetry of the looping heart gives rise to the chirality of the twisted brain. A computational model is used to interpret these findings. Our work clarifies the mechanical origins of brain torsion and the associated left-right asymmetry, reminiscent of D'Arcy Thompson's view of biological form as ``diagram of forces''.

Twisted boundary states and representation of generalized fusion algebra

International Nuclear Information System (INIS)

Ishikawa, Hiroshi; Tani, Taro

2006-01-01

The mutual consistency of boundary conditions twisted by an automorphism group G of the chiral algebra is studied for general modular invariants of rational conformal field theories. We show that a consistent set of twisted boundary states associated with any modular invariant realizes a non-negative integer matrix representation (NIM-rep) of the generalized fusion algebra, an extension of the fusion algebra by representations of the twisted chiral algebra associated with the automorphism group G. We check this result for several concrete cases. In particular, we find that two NIM-reps of the fusion algebra for su(3) k (k=3,5) are organized into a NIM-rep of the generalized fusion algebra for the charge-conjugation automorphism of su(3) k . We point out that the generalized fusion algebra is non-commutative if G is non-Abelian and provide some examples for G-bar S 3 . Finally, we give an argument that the graph fusion algebra associated with simple current extensions coincides with the generalized fusion algebra for the extended chiral algebra, and thereby explain that the graph fusion algebra contains the fusion algebra of the extended theory as a subalgebra

Twisted Frobenius Identities from Vertex Operator Superalgebras

Directory of Open Access Journals (Sweden)

Alexander Zuevsky

2017-01-01

Full Text Available In consideration of the continuous orbifold partition function and a generating function for all n-point correlation functions for the rank two free fermion vertex operator superalgebra on the self-sewing torus, we introduce the twisted version of Frobenius identity.

Analysis of a Caenorhabditis elegans Twist homolog identifies conserved and divergent aspects of mesodermal patterning

OpenAIRE

Harfe, Brian D.; Gomes, Ana Vaz; Kenyon, Cynthia; Liu, Jun; Krause, Michael; Fire, Andrew

1998-01-01

Mesodermal development is a multistep process in which cells become increasingly specialized to form specific tissue types. In Drosophila and mammals, proper segregation and patterning of the mesoderm involves the bHLH factor Twist. We investigated the activity of a Twist-related factor, CeTwist, during Caenorhabditis elegans mesoderm development. Embryonic mesoderm in C. elegans derives from a number of distinct founder cells that are specified during the early lineages; in contrast, a singl...

Modelling higher twist contributions to deep inelastic scattering with diquarks

International Nuclear Information System (INIS)

Anselmino, M.; Caruso, F.; Penna Firme, A.; Soares, J.; Mello Neto, J.R.T. de

1994-08-01

The most recent detailed data on the unpolarized nucleon structure functions allow a precise determination of higher twist contributions. Quark-quark correlations induced by colour forces are expected to be a natural explanation for such effects: indeed, a quark-diquark picture of the nucleon, previously introduced in the description of several exclusive processes at intermediate Q 2 values, is found to model the proton higher twist data with great accuracy. The resulting parameters are consistent with the diquark properties suggested by other experimental and theoretical analyses. (author). 15 refs, 5 figs

The SU(∞) twisted gradient flow running coupling

Energy Technology Data Exchange (ETDEWEB)

Pérez, Margarita García [Instituto de Física Teórica UAM-CSIC,Nicolás Cabrera 13-15, E-28049-Madrid (Spain); González-Arroyo, Antonio [Instituto de Física Teórica UAM-CSIC,Nicolás Cabrera 13-15, E-28049-Madrid (Spain); Departamento de Física Teórica, C-15, Universidad Autónoma de Madrid,E-28049-Madrid (Spain); Keegan, Liam [PH-TH, CERN,CH-1211 Geneva 23 (Switzerland); Okawa, Masanori [Graduate School of Science, Hiroshima University,Higashi-Hiroshima, Hiroshima 739-8526 (Japan)

2015-01-09

We measure the running of the SU(∞) ’t Hooft coupling by performing a step scaling analysis of the Twisted Eguchi-Kawai (TEK) model, the SU(N) gauge theory on a single site lattice with twisted boundary conditions. The computation relies on the conjecture that finite volume effects for SU(N) gauge theories defined on a 4-dimensional twisted torus are controlled by an effective size parameter l-tilde=l√N, with l the torus period. We set the scale for the running coupling in terms of l-tilde and use the gradient flow to define a renormalized ’t Hooft coupling λ(l-tilde). In the TEK model, this idea allows the determination of the running of the coupling through a step scaling procedure that uses the rank of the group as a size parameter. The continuum renormalized coupling constant is extracted in the zero lattice spacing limit, which in the TEK model corresponds to the large N limit taken at fixed value of λ(l-tilde). The coupling constant is thus expected to coincide with that of the ordinary pure gauge theory at N=∞. The idea is shown to work and permits us to follow the evolution of the coupling over a wide range of scales. At weak coupling we find a remarkable agreement with the perturbative two-loop formula for the running coupling.

Radiative capture of cold neutrons by protons and deuteron photodisintegration with twisted beams

Science.gov (United States)

Afanasev, Andrei; Serbo, Valeriy G.; Solyanik, Maria

2018-05-01

We consider two basic nuclear reactions: capture of neutrons by protons, n + p → γ + d, and its time-reversed counterpart, photodisintegration of the deuteron, γ + d → n + p. In both of these cases we assume that the incoming beam of neutrons or photons is ‘twisted’ by having an azimuthal phase dependence, i.e., it carries an additional angular momentum along its direction of propagation. Taking a low-energy limit of these reactions, we derive relations between corresponding transition amplitudes and cross sections with plane-wave beams and twisted beams. Implications for experiments with twisted cold neutrons and twisted photon beams are discussed.

A tale with a Twist: a developmental gene with potential relevance for metabolic dysfunction and inflammation in adipose tissue

Directory of Open Access Journals (Sweden)

Anca Dana Dobrian

2012-08-01

Full Text Available The Twist proteins (Twist-1 and -2 are highly conserved developmental proteins with key roles for the transcriptional regulation in mesenchymal cell lineages. They belong to the super-family of bHLH proteins and exhibit bi-functional roles as both activators and repressors of gene transcription. The Twist proteins are expressed at low levels in adult tissues but may become abundantly re-expressed in cells undergoing malignant transformation. This observation prompted extensive research on the roles of Twist proteins in cancer progression and metastasis. Very recent studies indicate a novel role for Twist-1 as a potential regulator of adipose tissue remodeling and inflammation. Several studies suggested that developmental genes are important determinants of obesity, fat distribution and remodeling capacity of different adipose depots. Twist-1 is abundantly and selectively expressed in the adult adipose tissue and its constitutive expression is significantly higher in subcutaneous vs. visceral fat in both mice and humans. Moreover, Twist1 expression is strongly correlated with BMI and insulin resistance in humans. However, the functional roles and transcriptional downstream targets of Twist1 in adipose tissue are largely unexplored. The purpose of this review is to highlight the major findings related to Twist1 expression in different fat depots and cellular components of adipose tissue and to discuss the potential mechanisms suggesting a role for Twist1 in adipose tissue metabolism, inflammation and remodeling.

Technical advances in flow cytometry-based diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria

Science.gov (United States)

Correia, Rodolfo Patussi; Bento, Laiz Cameirão; Bortolucci, Ana Carolina Apelle; Alexandre, Anderson Marega; Vaz, Andressa da Costa; Schimidell, Daniela; Pedro, Eduardo de Carvalho; Perin, Fabricio Simões; Nozawa, Sonia Tsukasa; Mendes, Cláudio Ernesto Albers; Barroso, Rodrigo de Souza; Bacal, Nydia Strachman

2016-01-01

ABSTRACT Objective: To discuss the implementation of technical advances in laboratory diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria for validation of high-sensitivity flow cytometry protocols. Methods: A retrospective study based on analysis of laboratory data from 745 patient samples submitted to flow cytometry for diagnosis and/or monitoring of paroxysmal nocturnal hemoglobinuria. Results: Implementation of technical advances reduced test costs and improved flow cytometry resolution for paroxysmal nocturnal hemoglobinuria clone detection. Conclusion: High-sensitivity flow cytometry allowed more sensitive determination of paroxysmal nocturnal hemoglobinuria clone type and size, particularly in samples with small clones. PMID:27759825

Generalized Weyl modules for twisted current algebras

Science.gov (United States)

Makedonskyi, I. A.; Feigin, E. B.

2017-08-01

We introduce the notion of generalized Weyl modules for twisted current algebras. We study their representation-theoretic and combinatorial properties and also their connection with nonsymmetric Macdonald polynomials. As an application, we compute the dimension of the classical Weyl modules in the remaining unknown case.

Multi-channel imaging cytometry with a single detector

Science.gov (United States)

Locknar, Sarah; Barton, John; Entwistle, Mark; Carver, Gary; Johnson, Robert

2018-02-01

Multi-channel microscopy and multi-channel flow cytometry generate high bit data streams. Multiple channels (both spectral and spatial) are important in diagnosing diseased tissue and identifying individual cells. Omega Optical has developed techniques for mapping multiple channels into the time domain for detection by a single high gain, high bandwidth detector. This approach is based on pulsed laser excitation and a serial array of optical fibers coated with spectral reflectors such that up to 15 wavelength bins are sequentially detected by a single-element detector within 2.5 μs. Our multichannel microscopy system uses firmware running on dedicated DSP and FPGA chips to synchronize the laser, scanning mirrors, and sampling clock. The signals are digitized by an NI board into 14 bits at 60MHz - allowing for 232 by 174 pixel fields in up to 15 channels with 10x over sampling. Our multi-channel imaging cytometry design adds channels for forward scattering and back scattering to the fluorescence spectral channels. All channels are detected within the 2.5 μs - which is compatible with fast cytometry. Going forward, we plan to digitize at 16 bits with an A-toD chip attached to a custom board. Processing these digital signals in custom firmware would allow an on-board graphics processing unit to display imaging flow cytometry data over configurable scanning line lengths. The scatter channels can be used to trigger data buffering when a cell is present in the beam. This approach enables a low cost mechanically robust imaging cytometer.

/sup 99m/Tc labelled ulcer avid agents

International Nuclear Information System (INIS)

Scopinaro, F.; Linari, G.; Baldieri, M.; Liberatore, M.; Corti, E.; Signori, C.

1986-01-01

Sulfated oligosaccharides have some interesting pharmacological properties: they are anticoagulants and protect the ulcerative areas of epithelia by precipitating over ulcers together with exudative proteins. Some sucralfate labelling methods using /sup 75/Se, /sup 111/In, /sup 99m/Tc-albumin and /sup 99m/Tc-DTPA have been reported. Only the /sup 99m/Tc-sucralfate has, at present, the requisites to be used as an ulcer-seeking agent. The aim of this study were: (a) to introduce a simple and easy-to-repeat method for the labelling of sucralfate with /sup 99m/Tc-DTPA; (b) to demonstrate that it is possible to label the sucrose octasulfate directly with /sup 99m/Tc without the aid of other ligands (e.g. DTPA)

Evaluation of '9{sup 9}Mo presence in eluates of {sup 99}mTc used in nuclear medicine; Avaliacao da presenca de {sup 99}Mo em eluatos de {sup 99m}Tc utilizados em medicina nuclear

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Bianca da Silva

2010-07-01

Tc-99m is used for diagnostic imaging in nuclear medicine through SPECT technique. It is obtained by the elution of {sup 99}Mo/{sup 99m}Tc generators. During the elution process {sup 99}Mo can be extracted becoming a radionuclidic impurity. One of the quality parameters of the eluate is the radionuclidic purity, MBT (molybdenum break through), defined as the ratio between {sup 99}Mo and {sup 99m}Tc activities in the eluate. The North-American and European pharmacopoeias restrict the {sup 99}Mo content, respectively, in 0.015 e 0.1% and, according to the International Atomic Energy Agency (IAEA), the activity ratio at the moment of administration of the radiopharmaceutical to the patient, should not exceed 0.015%. In Brazil, the control of such parameter is not obliged in official regulations. Thus, the objective of this work is to evaluate the occurrence of {sup 99}Mo in {sup 99m}Tc eluates. It was initially optimized a methodology to determine the activity of {sup 99}Mo in eluate samples. Efficiency curves were obtained for a NaI (Tl) 8'' x 4'' scintillation detector installed at the In Vivo Monitoring Laboratory (LABMIV-IRD). The methodology has been validated through the measurement of a {sup 99}Mo standard liquid source calibrated at the National Metrology Laboratory for Ionizing Radiation (LNMRI-IRD). The samples analyzed in this work were gently supplied by 5 Nuclear Medicine Clinics located in the city of Rio de Janeiro. The activities of {sup 99}mTc and {sup 99}Mo in those samples have been measured respectively at the clinics and at the LABMIV. By applying a standardized methodology, the ration between the activities were calculated. The results show that 147 out of 174 samples presented {sup 99}Mo activities above the minimum detectable activity of the technique. On the other hand, only 2 out of 147 samples surpassed the MBT limit suggested by the IAEA and have been detected in samples eluted from generators of 750 mCi. In one of the

On the description of exclusive processes beyond the leading twist approximation

International Nuclear Information System (INIS)

Anikin, I.V.; Ivanov, D.Yu.; Pire, B.; Szymanowski, L.; Wallon, S.

2010-01-01

We describe hard exclusive processes beyond the leading twist approximation in a framework based on the Taylor expansion of the amplitude around the dominant light-cone directions. This naturally introduces an appropriate set of non-perturbative correlators whose number is minimalized after taking into account QCD equations of motion and the invariance under rotation on the light-cone. We exemplify this method at the twist 3 level and show that the coordinate and momentum space descriptions are fully equivalent.

On the description of exclusive processes beyond the leading twist approximation

Energy Technology Data Exchange (ETDEWEB)

Anikin, I.V. [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation); Ivanov, D.Yu. [Institute of Mathematics, 630090 Novosibirsk (Russian Federation); Pire, B., E-mail: pire@cpht.polytechnique.f [CPhT, Ecole Polytechnique, CNRS, F-91128 Palaiseau (France); Szymanowski, L. [Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland); Wallon, S. [LPT, Universite d' Orsay, CNRS, 91404 Orsay (France); UPMC Univ. Paris 6, Faculte de Physique, 4 place Jussieu, 75252 Paris Cedex 05 (France)

2010-01-04

We describe hard exclusive processes beyond the leading twist approximation in a framework based on the Taylor expansion of the amplitude around the dominant light-cone directions. This naturally introduces an appropriate set of non-perturbative correlators whose number is minimalized after taking into account QCD equations of motion and the invariance under rotation on the light-cone. We exemplify this method at the twist 3 level and show that the coordinate and momentum space descriptions are fully equivalent.

Artificial blood-flow controlling effects of inhomogeneity of twisted magnetic fields

International Nuclear Information System (INIS)

Nakagawa, Hidenori; Ohuchi, Mikio

2017-01-01

We developed a blood-flow controlling system using magnetic therapy for some types of nervous diseases. In our research, we utilized overlapped extremely low frequency (ELF) fields for the most effective blood-flow for the system. Results showed the possibility that the inhomogeneous region obtained by overlapping the fields at 50 Hz, namely, a desirably twisted field revealed a significant difference in induced electromotive forces at the insertion points of electrodes. In addition, ELF exposures with a high inhomogeneity of the twisted field at 50 Hz out of phase were more effective in generating an induced electromotive difference by approximately 31%, as contrasted with the difference generated by the exposure in phase. We expect that the increase of the inhomogeneity of the twisted field around a blood vessel can produce the most effective electromotive difference in the blood, and also moderately affect the excitable cells relating to the autonomic nervous system for an outstanding blood-flow control in vivo. - Highlights: • The principal aim of this research is to contribute to the utilization of the twisted fields for the most effective blood-flow in vivo. • Two newly designed coil systems were used for producing a desirably twisted magnetic field under the measuring domain in the flow channel. • Further, we investigated the magnetohydrodynamic efficiencies of a prototype of a magnetic device, which was converted from use as a commercial alternating magnetic therapy apparatus. • The system was well-constructed with a successful application of a plural exposure coil; therefore, we were able to detect a maximum of induced electromotive force in a fluid of an artificial solution as a substitute for blood. • This new finding demonstrates that the process of blood massotherapy by magnetic stimuli is a therapy for many diseases.

Artificial blood-flow controlling effects of inhomogeneity of twisted magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Hidenori, E-mail: hnakagawa-tdt@umin.ac.jp; Ohuchi, Mikio

2017-06-01

We developed a blood-flow controlling system using magnetic therapy for some types of nervous diseases. In our research, we utilized overlapped extremely low frequency (ELF) fields for the most effective blood-flow for the system. Results showed the possibility that the inhomogeneous region obtained by overlapping the fields at 50 Hz, namely, a desirably twisted field revealed a significant difference in induced electromotive forces at the insertion points of electrodes. In addition, ELF exposures with a high inhomogeneity of the twisted field at 50 Hz out of phase were more effective in generating an induced electromotive difference by approximately 31%, as contrasted with the difference generated by the exposure in phase. We expect that the increase of the inhomogeneity of the twisted field around a blood vessel can produce the most effective electromotive difference in the blood, and also moderately affect the excitable cells relating to the autonomic nervous system for an outstanding blood-flow control in vivo. - Highlights: • The principal aim of this research is to contribute to the utilization of the twisted fields for the most effective blood-flow in vivo. • Two newly designed coil systems were used for producing a desirably twisted magnetic field under the measuring domain in the flow channel. • Further, we investigated the magnetohydrodynamic efficiencies of a prototype of a magnetic device, which was converted from use as a commercial alternating magnetic therapy apparatus. • The system was well-constructed with a successful application of a plural exposure coil; therefore, we were able to detect a maximum of induced electromotive force in a fluid of an artificial solution as a substitute for blood. • This new finding demonstrates that the process of blood massotherapy by magnetic stimuli is a therapy for many diseases.

Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

Energy Technology Data Exchange (ETDEWEB)

Tangler, J.L. [National Renewable Energy Lab., Golden, CO (United States)

1996-12-31

The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. 8 refs., 6 figs.

Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

Energy Technology Data Exchange (ETDEWEB)

Tangler, J.L. [National Renewable Energy Laboratory, Golden, Colorado (United States)

1997-08-01

The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. (au)

Cytobank: providing an analytics platform for community cytometry data analysis and collaboration.

Science.gov (United States)

Chen, Tiffany J; Kotecha, Nikesh

2014-01-01

Cytometry is used extensively in clinical and laboratory settings to diagnose and track cell subsets in blood and tissue. High-throughput, single-cell approaches leveraging cytometry are developed and applied in the computational and systems biology communities by researchers, who seek to improve the diagnosis of human diseases, map the structures of cell signaling networks, and identify new cell types. Data analysis and management present a bottleneck in the flow of knowledge from bench to clinic. Multi-parameter flow and mass cytometry enable identification of signaling profiles of patient cell samples. Currently, this process is manual, requiring hours of work to summarize multi-dimensional data and translate these data for input into other analysis programs. In addition, the increase in the number and size of collaborative cytometry studies as well as the computational complexity of analytical tools require the ability to assemble sufficient and appropriately configured computing capacity on demand. There is a critical need for platforms that can be used by both clinical and basic researchers who routinely rely on cytometry. Recent advances provide a unique opportunity to facilitate collaboration and analysis and management of cytometry data. Specifically, advances in cloud computing and virtualization are enabling efficient use of large computing resources for analysis and backup. An example is Cytobank, a platform that allows researchers to annotate, analyze, and share results along with the underlying single-cell data.

γγ → M{sup +}M{sup -}(M = π, K) processes with twist-3 corrections in QCD

Energy Technology Data Exchange (ETDEWEB)

Wang, Cong [Southwest University, School of Physical Science and Technology, Chongqing (China); Chinese Academy of Sciences, State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); Zhou, Ming-Zhen; Chen, Hong [Southwest University, School of Physical Science and Technology, Chongqing (China)

2017-04-15

We study the γγ → M{sup +}M{sup -}(M = π, K) processes with the contributions from the two-particle twist-2 and twist-3 distribution amplitudes of pion and kaon mesons on BHL prescription in the standard hard-scattering approach. The results show that the contributions from twist-3 parts are actually not power suppressed compared with the leading-twist contributions in the low energy region. The cross sections with twist-3 corrections agree well with the experimental data in the two-photon center-of-mass energy W > 2.8 GeV and we also predict the cross section ratio σ{sub 0}(K{sup +}K{sup -})/σ{sub 0}(π{sup +}π{sup -}), which is compatible with the experimental data from TPC and Belle. (orig.)

An estimate of higher twist at small xB and low Q2 based upon a saturation model

International Nuclear Information System (INIS)

Bartels, J.; Peters, K.

2000-03-01

We investigate the influence of higher twist corrections to deep inelastic structure functions in the low-Q 2 and small-x HERA region. We review the general features of the lowest-order QCD diagrams which contribute to twist-4 at small-x, in particular the sign structure of longitudinal and transverse structure functions which offers the possibility of strong cancellations in F 2 . For a numerical analysis we perform a twist analysis of the saturation model which has been very successful both in describing the structure function and the DIS diffractive cross section at HERA. As the main conclusion, twist 4 corrections are not small in F L or F T but in F 2 = F L + F T they almost cancel. We point out that F L analysis needs a large twist-4 correction. We also indicate the region of validity of the twist expansion. (orig.)

Numerical investigation of heat transfer and friction factor characteristics in a circular tube fitted with V-cut twisted tape inserts.

Science.gov (United States)

Salman, Sami D; Kadhum, Abdul Amir H; Takriff, Mohd S; Mohamad, Abu Bakar

2013-01-01

Numerical investigation of the heat transfer and friction factor characteristics of a circular fitted with V-cut twisted tape (VCT) insert with twist ratio (y = 2.93) and different cut depths (w = 0.5, 1, and 1.5 cm) were studied for laminar flow using CFD package (FLUENT-6.3.26). The data obtained from plain tube were verified with the literature correlation to ensure the validation of simulation results. Classical twisted tape (CTT) with different twist ratios (y = 2.93, 3.91, 4.89) were also studied for comparison. The results show that the enhancement of heat transfer rate induced by the classical and V-cut twisted tape inserts increases with the Reynolds number and decreases with twist ratio. The results also revealed that the V-cut twisted tape with twist ratio y = 2.93 and cut depth w = 0.5 cm offered higher heat transfer rate with significant increases in friction factor than other tapes. In addition the results of V-cut twist tape compared with experimental and simulated data of right-left helical tape inserts (RLT), it is found that the V-cut twist tape offered better thermal contact between the surface and the fluid which ultimately leads to a high heat transfer coefficient. Consequently, 107% of maximum heat transfer was obtained by using this configuration.

99mTc-3PRGD2 Scintimammography in Palpable and Nonpalpable Breast Lesions

Directory of Open Access Journals (Sweden)

Lin Liu

2014-07-01

Full Text Available The aim of this study was to explore the diagnostic performance of 99mTc-3(poly-(ethylene glycol,PEG4-RGD2 (99mTc-3PRGD2 scintimammography (SMM in patients with either palpable or nonpalpable breast lesions and compare SMM to mammography to assess the possible incremental value of SMM in breast cancer detection. We also investigated the αvβ3 expression in malignant and benign breast lesions. Ninety-four patients with 110 lesions were included in this study. Mammograms were evaluated according to the Breast Imaging Reporting and Data System (BI-RADS by a specialized imaging radiologist. Prone SMM was performed 1 hour after injection of 99mTc-3PRGD2. Scintigraphic images were interpreted independently by two experienced nuclear medicine physicians using a three-point system, and the kappa value was calculated to determine the interreader agreement. The McNemar test was used to compare SMM and mammography with respect to sensitivity, specificity, and accuracy. Diagnostic values for breast cancer detection were evaluated for each lesion. Immunohistochemistry was performed to evaluate integrin αvβ3 expression. Histopathology revealed 46 malignant lesions and 64 benign lesions. The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SMM were 83%, 73%, 77%, 69%, and 85%, respectively. The kappa value between the two reviewers was 0.63. The diagnostic values of SMM were higher than those of mammography in evaluating overall breast lesions. A sensitivity of 91% was achieved when SMM and mammography results were combined with 60% of all false-negative mammography findings classified as true-positive results by SMM. Integrin αvβ3 expression was positively identified using SMM imaging. SMM is a promising tool to avoid unnecessary biopsies when used in addition to mammography and can be used to image αvβ3 expression in breast cancer with good image quality.

Immediate renal imaging and renography with /sup 99m/Tc methylene diphosphonate to assess renal blood flow, excretory function, and anatomy

International Nuclear Information System (INIS)

Glass, E.C.; DeNardo, G.L.; Hines, H.H.

1980-01-01

/sup 99m/Tc methylene diphosphonate (/sup 99m/Tc MDP) was evaluated as a clinical renal imaging agent in 20 patients referred for bone scintigraphy. Sequential scintigraphy, which was started immediately after injection, yielded blood flow studies of high quality, and subsequent images accurately delineated renal anatomy and excretion in nonazotemic patients. In comparison with delayed images, early images were vastly superior in quality and demonstrated improved target-to-nontarget activity ratios (p < 0.001) and improved lesion detectability (p < 0.01). Renal imaging performed incidental to bone scintigraphy with MDP can be greatly enhanced by initiating sequential scintigraphy immediately after injection

RESONANT ABSORPTION OF AXISYMMETRIC MODES IN TWISTED MAGNETIC FLUX TUBES

Energy Technology Data Exchange (ETDEWEB)

Giagkiozis, I.; Verth, G. [Solar Plasma Physics Research Centre, School of Mathematics and Statistics, University of Sheffield, Hounsfield Road, Hicks Building, Sheffield, S3 7RH (United Kingdom); Goossens, M.; Doorsselaere, T. Van [Centre for mathematical Plasma Astrophysics, Mathematics Department, KU Leuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Fedun, V. [Department of Automatic Control and Systems Engineering, University of Sheffield, Mappin Street, Amy Johnson Building, Sheffield, S1 3JD (United Kingdom)

2016-06-01

It has been shown recently that magnetic twist and axisymmetric MHD modes are ubiquitous in the solar atmosphere, and therefore the study of resonant absorption for these modes has become a pressing issue because it can have important consequences for heating magnetic flux tubes in the solar atmosphere and the observed damping. In this investigation, for the first time, we calculate the damping rate for axisymmetric MHD waves in weakly twisted magnetic flux tubes. Our aim is to investigate the impact of resonant damping of these modes for solar atmospheric conditions. This analytical study is based on an idealized configuration of a straight magnetic flux tube with a weak magnetic twist inside as well as outside the tube. By implementing the conservation laws derived by Sakurai et al. and the analytic solutions for weakly twisted flux tubes obtained recently by Giagkiozis et al. we derive a dispersion relation for resonantly damped axisymmetric modes in the spectrum of the Alfvén continuum. We also obtain an insightful analytical expression for the damping rate in the long wavelength limit. Furthermore, it is shown that both the longitudinal magnetic field and the density, which are allowed to vary continuously in the inhomogeneous layer, have a significant impact on the damping time. Given the conditions in the solar atmosphere, resonantly damped axisymmetric modes are highly likely to be ubiquitous and play an important role in energy dissipation. We also suggest that, given the character of these waves, it is likely that they have already been observed in the guise of Alfvén waves.

A modified method for the in vivo labeling of red blood cells with /sup 99m/Tc: concise communication

International Nuclear Information System (INIS)

Callahan, R.J.; Froelich, J.W.; McKusick, K.A.; Leppo, J.; Strauss, H.W.

1982-01-01

The rate of incorporation of /sup 99m/Tc into red blood cells pretinned in vivo was measured by collecting blood samples in stannous DTPA solution, which served as a competing ligand for /sup 99m/Tc. This collection technique permitted a measurement of high-affinity red-cell labeling efficiency at the instant of sampling. At 0.5 min after injection only 62% of technetium is tightly bound to the red cell; this rises to 94.5% at 10 min. Based on the graded labeling of the red cells, the in vivo labeling procedure was modified by isolating pertechnetate and red blood cells tinned in vivo in a syringe during the first 10 min of labeling. The pertechnetate is thus prevented from distributing to extravascular compartments, and 90% of the injected /sup 99m/Tc is firmly bound to red blood cells at the time of injection. In a series of 23 patients, seven were tested with the in vivo method and seven with the modified in vivo method, and nine patients were tested with each method on separate occasions. A decrease in gastric activity and improved image quality were found with the modified method compared with the standard method of in vivo red-cell labeling

Twist and YB-1 gene expression in cervical cancer and precancerous tissue and their correlation with cell invasion

Directory of Open Access Journals (Sweden)

Qin Tian

2017-04-01

Full Text Available Objective: To study the correlation of Twist and YB-1 gene expression in cervical cancer and precancerous tissue with cell invasion. Methods: Cervical cancer tissue, precancerous tissue and normal cervical tissue surgically removed in our hospital between May 2013 and April 2015 were collected; immunohistochemical staining kits were used to detect the positive protein expression rate of Twist and YB-1 gene; fluorescence quantitative PCR kits were used to detect Twist, YB-1 and invasion gene mRNA expression. Results: Twist and YB-1 mRNA expression and positive protein expression rate as well as USP22, Rab11, Rac1 and ANXA5 mRNA expression in cervical cancer tissue and precancerous tissue were significantly higher than those in normal cervical tissue, Twist and YB-1 mRNA expression and positive protein expression rate as well as USP22, Rab11, Rac1 and ANXA5 mRNA expression in cervical cancer tissue were significantly higher than those in precancerous tissue; USP22, Rab11, Rac1 and ANXA5 mRNA expression in cervical cancer tissue and precancerous tissue with positive Twist and YB-1 expression were significantly higher than those in cervical cancer tissue and precancerous tissue with negative Twist and YB-1 expression. Conclusion: Highly expressed Twist and YB-1 in cervical cancer and precancerous tissue can promote cell invasion.

Simultaneous 99mTc and 123I dual-isotope brain striatal phantom single photon emission computed tomography: validation of 99mTc-TRODAT-1 and 123I-IBZM simultaneous dopamine system brain imaging.

Science.gov (United States)

Kao, Pan-Fu; Wey, Shiaw-Pyng; Yang, An-Shoei

2009-11-01

[2[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]-oct-2-yl]-methyl](2-mercaptoethyl)-amino]ethyl]amino]ethanethiolato(3-)-N2,N2',S2,S2]oxo-[1R-exo-exo)])-[99mTc]-technetium (99mTc-TRODAT-1) and 123I-iodobenzamide (123I-IBZM) are radiotracers for brain dopamine pre- and postsynaptic neuron imaging. The purpose of this study was to evaluate imaging parameters and crossed energy interference using simultaneous single photon emission computed tomography (SPECT) 99mTc and 123I data acquisition. A five-compartment brain striatal phantom was filled with 99mTc and/or 123I radioactive solutions with different striatal-to-background ratios, ranging from 3:1 to 9:1. SPECT data were acquired with energy window settings of 15% for the centered window at 140 keV for 99mTc and a 10% asymmetric window at 159 keV for 123I. The experiments were carried out using either individual (99mTc or 123I only) or both radionuclides. The striatal-to-background ratios and energy crossed interference between 99mTc and 123I were calculated. The phantom SPECT images demonstrated that the energy crossed interferences from 123I to 99mTc, and vice versa, were 22 +/- 12.4% and 0.4 +/- 1.0%, respectively. A net interference of 7.1 +/- 4.0% for the counts in the 15% centered 99mTc window can be expected from 123I and a net interference of 1.6 +/- 3.3% for the counts in the 10% asymmetric 123I window was derived from 99mTc. The correlation of striatal-to-background ratios between single isotope and simultaneous dual-isotope was excellent (R2 = 0.99). The imaging parameters used in this simultaneous dualisotope SPECT imaging could be used in future clinical practice for imaging patients with movement disorders by using 99mTc-TRODAT-1 and 123I-IBZM. The striatal-to-background ratios were not affected by the crossed interference between 99mTc and 123I.

Simultaneous 99mTC and 123I Dual-Isotope Brain Striatal Phantom Single Photon Emission Computed Tomography: Validation of 99mTC-Trodat-1 and 123I-IBZM Simultaneous Dopamine System Brain Imaging

Directory of Open Access Journals (Sweden)

Pan-Fu Kao

2009-11-01

Full Text Available [2[[2-[[[3-(4-chlorophenyl-8-methyl-8-azabicyclo[3,2,1]-oct-2-yl]-methyl](2-mercaptoethylamino]ethyl]amino]ethanethiolato(3--N2,N2′,S2,S2]oxo-[1R-exo-exo]-[99mTc]-technetium (99mTc-TRODAT-1 and 123I-iodobenzamide (123I-IBZM are radiotracers for brain dopamine preand postsynaptic neuron imaging. The purpose of this study was to evaluate imaging parameters and crossed energy interference using simultaneous single photon emission computed tomography (SPECT 99mTc and 123I data acquisition. A five-compartment brain striatal phantom was filled with 99mTc and/or 123I radioactive solutions with different striatal-to-background ratios, ranging from 3:1 to 9:1. SPECT data were acquired with energy window settings of 15% for the centered window at 140 keV for 99mTc and a 10% asymmetric window at 159 keV for 123I. The experiments were carried out using either individual (99mTc or 123I only or both radionuclides. The striatal-to-background ratios and energy crossed interference between 99mTc and 123I were calculated. The phantom SPECT images demonstrated that the energy crossed interferences from 123I to 99mTc, and vice versa, were 22 ± 12.4% and 0.4 ± 1.0%, respectively. A net interference of 7.1 ± 4.0% for the counts in the 15% centered 99mTc window can be expected from 123I and a net interference of 1.6 ± 3.3% for the counts in the 10% asymmetric 123I window was derived from 99mTc. The correlation of striatal-to-background ratios between single isotope and simultaneous dual-isotope was excellent (R2 = 0.99. The imaging parameters used in this simultaneous dual-isotope SPECT imaging could be used in future clinical practice for imaging patients with movement disorders by using 99mTc-TRODAT-1 and 123I-IBZM. The striatal-to-background ratios were not affected by the crossed interference between 99mTc and 123I.

Electric currents induced by twisted light in Quantum Rings.

Science.gov (United States)

Quinteiro, G F; Berakdar, J

2009-10-26

We theoretically investigate the generation of electric currents in quantum rings resulting from the optical excitation with twisted light. Our model describes the kinetics of electrons in a two-band model of a semiconductor-based mesoscopic quantum ring coupled to light having orbital angular momentum (twisted light). We find the analytical solution, which exhibits a "circular" photon-drag effect and an induced magnetization, suggesting that this system is the circular analog of that of a bulk semiconductor excited by plane waves. For realistic values of the electric field and material parameters, the computed electric current can be as large as microA; from an applied perspective, this opens new possibilities to the optical control of the magnetization in semiconductors.

MAML1 and TWIST1 co-overexpression promote invasion of head and neck squamous cell carcinoma.

Science.gov (United States)

Ardalan Khales, Sima; Ebrahimi, Ehsan; Jahanzad, Eisa; Ardalan Khales, Sahar; Forghanifard, Mohammad Mahdi

2018-01-15

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common cancer worldwide with considerable morbidity and mortality. Invasion and metastasis of HNSCC is a complex process involving multiple molecules and signaling pathways. Twist Family BHLH Transcription Factor 1 (TWIST1) and Mastermind-like 1 (MAML1) are essential in induction of epithelial-mesenchymal transition through direct regulation of implicated molecules in cellular adhesion, migration and invasion. Our aim in this study was to assess the clinical significance of MAML1 and TWIST1 expression in HNSCC, and elucidate the probable correlation between these genes to exhibit their possible associations with progression and metastasis of the disease. The gene expression profile of MAML1 and TWIST1 was assessed in fresh tumoral compared to distant tumor-free tissues of 55 HNSCC patients using quantitative real-time Polymerase chain reaction (PCR). Significant overexpression of MAML1 and TWIST1 mRNA was observed in 49.1% and 38.2% (P ˂ 0.05) of tumor specimens, respectively. Overexpression of MAML1 was associated with vascular invasion (P = 0.048). Concomitant overexpression of MAML1 and TWIST1 was significantly correlated to each other (P = 0.004). Co-overexpression of the genes was significantly correlated to the various clinicopathological indices of poor prognosis including depth of tumor invasion (P < 0.01), lymphatic invasion and grade of tumor cell differentiation (P < 0.05). Significant correlation between MAML1 and TWIST1 in HNSCC was revealed. This study was the first report elucidating MAML1 clinical relevance in HNSCC. These new findings suggest an oncogenic role for concomitant expression of MAML1 and TWIST1 genes in HNSCC invasion and metastasis. © 2018 John Wiley & Sons Australia, Ltd.

Phenolic aminocarboxylate chelates of 99mTc as hepatobiliary agents.

Science.gov (United States)

Hunt, F C; Maddalena, D J; Wilson, J G; Bautovich, G J

1986-01-01

A series of alkyl- and halogen-substituted derivatives of ethylenediamine di[o-hydroxyphenylacetic acid] (EDDHA) and N,N'-bis[2-hydroxybenzyl] ethylenediamine N,N'-diacetic acid (HBED) were complexed with 99mTc and their biodistribution was determined in rats. All complexes displayed substantial hepatobiliary excretion; of each series, 99mTc-Br-EDDHA and 99mTc-di-Cl-HBED had the maximum amount in the gastrointestinal tract. Scintigraphic studies of 99mTc-Cl-EDDHA in dogs revealed prompt imaging of the liver followed by imaging of the gall bladder as the complex was excreted into the bile.

Examination of higher-order twist contributions in parity-violating deep-inelastic electron-deuteron scattering

International Nuclear Information System (INIS)

Mantry, Sonny; Ramsey-Musolf, Michael J.; Sacco, Gian Franco

2010-01-01

We show that parity-violating deep-inelastic scattering (PVDIS) of longitudinally polarized electrons from deuterium can in principle be a relatively clean probe of higher twist quark-quark correlations beyond the parton model. As first observed by Bjorken and Wolfenstein, the dominant contribution to the electron polarization asymmetry, proportional to the axial vector electron coupling, receives corrections at twist four from the matrix element of a single four-quark operator. We reformulate the Bjorken-Wolfenstein argument in a matter suitable for the interpretation of experiments planned at the Thomas Jefferson National Accelerator Facility (JLab). In particular, we observe that because the contribution of the relevant twist-four operator satisfies the Callan-Gross relation, the ratio of parity-violating longitudinal and transverse cross sections, R γZ , is identical to that for purely electromagnetic scattering, R γ , up to perturbative and power-suppressed contributions. This result simplifies the interpretation of the asymmetry in terms of other possible novel hadronic and electroweak contributions. We use the results of MIT Bag Model calculations to estimate contributions of the relevant twist-four operator to the leading term in the asymmetry as a function of Bjorken x and Q 2 . We compare these estimates with possible leading twist corrections from violation of charge symmetry in the parton distribution functions.

Twisting formula of epsilon factors

Indian Academy of Sciences (India)

Sazzad Ali Biswas

2017-08-07

Aug 7, 2017 ... In this article, we give a generalized twisting formula for ϵ(χ1χ2,ψ), when both χ1 and χ2 are ramified via the following local Jacobi sums. Let UF be the group of units in OF (ring of integers of F). For characters χ1, χ2 of F. × and a positive integer n, we define the local Jacobi sum. Jt(χ1,χ2, n) = ∑ x∈UF. Un.

Twist operator correlation functions in O(n) loop models

International Nuclear Information System (INIS)

Simmons, Jacob J H; Cardy, John

2009-01-01

Using conformal field theoretic methods we calculate correlation functions of geometric observables in the loop representation of the O(n) model at the critical point. We focus on correlation functions containing twist operators, combining these with anchored loops, boundaries with SLE processes and with double SLE processes. We focus further upon n = 0, representing self-avoiding loops, which corresponds to a logarithmic conformal field theory (LCFT) with c = 0. In this limit the twist operator plays the role of a 0-weight indicator operator, which we verify by comparison with known examples. Using the additional conditions imposed by the twist operator null states, we derive a new explicit result for the probabilities that an SLE 8/3 winds in various ways about two points in the upper half-plane, e.g. that the SLE passes to the left of both points. The collection of c = 0 logarithmic CFT operators that we use deriving the winding probabilities is novel, highlighting a potential incompatibility caused by the presence of two distinct logarithmic partners to the stress tensor within the theory. We argue that both partners do appear in the theory, one in the bulk and one on the boundary and that the incompatibility is resolved by restrictive bulk-boundary fusion rules

Artificial blood-flow controlling effects of inhomogeneity of twisted magnetic fields

Science.gov (United States)

Nakagawa, Hidenori; Ohuchi, Mikio

2017-06-01

We developed a blood-flow controlling system using magnetic therapy for some types of nervous diseases. In our research, we utilized overlapped extremely low frequency (ELF) fields for the most effective blood-flow for the system. Results showed the possibility that the inhomogeneous region obtained by overlapping the fields at 50 Hz, namely, a desirably twisted field revealed a significant difference in induced electromotive forces at the insertion points of electrodes. In addition, ELF exposures with a high inhomogeneity of the twisted field at 50 Hz out of phase were more effective in generating an induced electromotive difference by approximately 31%, as contrasted with the difference generated by the exposure in phase. We expect that the increase of the inhomogeneity of the twisted field around a blood vessel can produce the most effective electromotive difference in the blood, and also moderately affect the excitable cells relating to the autonomic nervous system for an outstanding blood-flow control in vivo.

Quark mass anomalous dimension from the twisted mass Dirac operator spectrum

Energy Technology Data Exchange (ETDEWEB)

Cichy, Krzysztof [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics

2013-12-15

We investigate whether it is possible to extract the quark mass anomalous dimension and its scale dependence from the spectrum of the twisted mass Dirac operator in Lattice QCD. The answer to this question appears to be positive, provided that one goes to large enough eigenvalues, sufficiently above the non-perturbative regime. The obtained results are compared to continuum perturbation theory. By analyzing possible sources of systematic effects, we find the domain of applicability of the approach, extending from an energy scale of around 1.5 to 4 GeV. The lower limit is dictated by physics (non-perturbative effects at low energies), while the upper bound is set by the ultraviolet cut-off of present-day lattice simulations. We use gauge field configuration ensembles generated by the European Twisted Mass Collaboration (ETMC) with 2 flavours of dynamical twisted mass quarks, at 4 lattice spacings in the range between around 0.04 and 0.08 fm.

Quark mass anomalous dimension from the twisted mass Dirac operator spectrum

International Nuclear Information System (INIS)

Cichy, Krzysztof; Poznan Univ.

2013-12-01

We investigate whether it is possible to extract the quark mass anomalous dimension and its scale dependence from the spectrum of the twisted mass Dirac operator in Lattice QCD. The answer to this question appears to be positive, provided that one goes to large enough eigenvalues, sufficiently above the non-perturbative regime. The obtained results are compared to continuum perturbation theory. By analyzing possible sources of systematic effects, we find the domain of applicability of the approach, extending from an energy scale of around 1.5 to 4 GeV. The lower limit is dictated by physics (non-perturbative effects at low energies), while the upper bound is set by the ultraviolet cut-off of present-day lattice simulations. We use gauge field configuration ensembles generated by the European Twisted Mass Collaboration (ETMC) with 2 flavours of dynamical twisted mass quarks, at 4 lattice spacings in the range between around 0.04 and 0.08 fm.

CytometryML with DICOM and FCS

Science.gov (United States)

Leif, Robert C.

2018-02-01

Abstract: Flow Cytometry Standard, FCS, and Digital Imaging and Communications in Medicine standard, DICOM, are based on extensive, superb domain knowledge, However, they are isolated systems, do not take advantage of data structures, require special programs to read and write the data, lack the capability to interoperate or work with other standards and FCS lacks many of the datatypes necessary for clinical laboratory data. The large overlap between imaging and flow cytometry provides strong evidence that both modalities should be covered by the same standard. Method: The XML Schema Definition Language, XSD 1.1 was used to translate FCS and/or DICOM objects. A MIFlowCyt file was tested with published values. Results: Previously, a significant part of an XML standard based upon a combination of FCS and DICOM has been implemented and validated with MIFlowCyt data. Strongly typed translations of FCS keywords have been constructed in XML. These keywords contain links to their DICOM and FCS equivalents.

Flow cytometry, fluorescent probes, and flashing bacteria

NARCIS (Netherlands)

Bunthof, C.J.

2002-01-01

Key words: fluorescent probes, flow cytometry, CSLM, viability, survival, microbial physiology, lactic acid bacteria, Lactococcus lactis , Lactobacillus plantarum , cheese, milk,