Unusual features of proton and α-spectra from low-energy heavy-ion ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 75; Issue 1. Unusual features ... Keywords. Proton and α-spectra; heavy-ion reaction; broad structures; nuclear level density. ... The broad structures in the -spectra cannot be fully explained within the statistical model even with the enhanced level density. In this case ...

An Analogy Using Pennies and Dimes to Explain Chemical Kinetics Concepts

Science.gov (United States)

Cortes-Figueroa, Jose E.; Perez, Wanda I.; Lopez, Jose R.; Moore-Russo, Deborah A.

2011-01-01

In this article, the authors present an analogy that uses coins and graphical analysis to teach kinetics concepts and resolve pseudo-first-order rate constants related to transition-metal complexes ligand-solvent exchange reactions. They describe an activity that is directed to upper-division undergraduate and graduate students. The activity…

Adenine phosphoribosyltransferase from Sulfolobus solfataricus is an enzyme with unusual kinetic properties and a crystal structure that suggests it evolved from a 6-oxopurine phosphoribosyltransferase.

Science.gov (United States)

Jensen, Kaj Frank; Hansen, Michael Riis; Jensen, Kristine Steen; Christoffersen, Stig; Poulsen, Jens-Christian Navarro; Mølgaard, Anne; Kadziola, Anders

2015-04-14

The adenine phosphoribosyltransferase (APRTase) encoded by the open reading frame SSO2342 of Sulfolobus solfataricus P2 was subjected to crystallographic, kinetic, and ligand binding analyses. The enzyme forms dimers in solution and in the crystals, and binds one molecule of the reactants 5-phosphoribosyl-α-1-pyrophosphate (PRPP) and adenine or the product adenosine monophosphate (AMP) or the inhibitor adenosine diphosphate (ADP) in each active site. The individual subunit adopts an overall structure that resembles a 6-oxopurine phosphoribosyltransferase (PRTase) more than known APRTases implying that APRT functionality in Crenarchaeotae has its evolutionary origin in this family of PRTases. Only the N-terminal two-thirds of the polypeptide chain folds as a traditional type I PRTase with a five-stranded β-sheet surrounded by helices. The C-terminal third adopts an unusual three-helix bundle structure that together with the nucleobase-binding loop undergoes a conformational change upon binding of adenine and phosphate resulting in a slight contraction of the active site. The inhibitor ADP binds like the product AMP with both the α- and β-phosphates occupying the 5'-phosphoribosyl binding site. The enzyme shows activity over a wide pH range, and the kinetic and ligand binding properties depend on both pH and the presence/absence of phosphate in the buffers. A slow hydrolysis of PRPP to ribose 5-phosphate and pyrophosphate, catalyzed by the enzyme, may be facilitated by elements in the C-terminal three-helix bundle part of the protein.

Response of the Pre-oriented Goal-directed Attention to Usual and Unusual Distractors: A Preliminary Study

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Golnaz Baghdadi

2017-03-01

Full Text Available Introduction: In this study, we investigated the distraction power of the unusual and usual images on the attention of 20 healthy primary school children. Methods: Our study was different from previous ones in that the participants were asked to fix the initial position of their attention on a pre-defined location after being presented with unusual images as distractors. The goals were presented in locations, which were far from the attraction basin of distractors. Our expectation was that the pre-orienting of the attention to the position of targets can reduce the attractive effect of unusual images compared to the usual ones. The percentage of correct responses and the reaction time have been measured as behavioral indicators of attention performance. Results: Results showed that using the goal-directed attention, subjects ignored both kinds of distractors nearly the same way. Conclusion: With regard to previous reports about the more attraction towards the unusual images, it is suggested that the dynamics of the visual attention system be sensitive to the initial condition. That is, changing the initial position of the attention can lead to the decrement of the unusual images’ effects. However, several other possibilities such as a probable delay in processing unusual features could explain this observation, too. 

Kinetic effects on magnetohydrodynamic phenomena

International Nuclear Information System (INIS)

Naito, Hiroshi; Matsumoto, Taro

2001-01-01

Resistive and ideal magnetohydrodynamic (MHD) theories are insufficient to adequately explain MHD phenomena in the high-temperature plasma. Recent progress in numerical simulations concerning kinetic effects on magnetohydrodynamic phenomena is summarized. The following three topics are studied using various models treating extended-MHD phenomena. (1) Kinetic modifications of internal kink modes in tokamaks with normal and reversed magnetic shear configurations. (2) Temporal evolution of the toroidal Alfven eigenmode and fishbone mode in tokamaks with energetic ions. (3) Kinetic stabilization of a title mode in field-reversed configurations by means of anchoring ions and beam ions. (author)

On the unusual magnetic behaviour of CeRh3B2

International Nuclear Information System (INIS)

Galatanu, A; Yamamoto, E; Okubo, T; Yamada, M; Thamizhavel, A; Takeuchi, T; Sugiyama, K; Inada, Y; Onuki, Y

2003-01-01

CeRh 3 B 2 is a ferromagnet with an unexpectedly high Curie temperature and low saturation magnetic moments. The origin of its unusual magnetic behaviour remains unelucidated despite various investigations performed in the last two decades. Here we present magnetic results obtained on high-quality single crystals over a wide temperature range. Some new magnetic features are uncovered and possible approaches to explaining its magnetism are briefly discussed

The nature of unusual luminescence in natural calcite, CaCO3

Energy Technology Data Exchange (ETDEWEB)

Gaft, M.; Nagli, L.; Panczer, G.; Waychunas, G.; Porat, N.

2008-11-01

The unusual luminescence of particular varieties of natural pink calcite (CaCO{sub 3}) samples was studied by laser-induced time-resolved luminescence spectroscopy at different temperatures. The luminescence is characterized by intense blue emission under short-wave UV lamp excitation with an extremely long decay time, accompanied by pink-orange luminescence under long wave UV excitation. Our investigation included optical absorption, natural thermostimulated luminescence (NTL) and Laser-Induced Breakdown Spectroscopy (LIBS) studies. Two luminescence centers were detected: a narrow violet band, with {lambda}{sub max} = 412 nm, {Delta} = 45 nm, two decay components of {tau}{sub 1} = 5 ns and {tau}{sub 2} = 7.2 ms, accompanied by very long afterglow, and an orange emission band with {lambda}{sub max} = 595 nm, {Delta} = 90 nm and {tau} = 5 ns. Both luminescence centers are thermally unstable with the blue emission disappearing after heating at 500 C, and the orange emission disappearing after heating at different temperatures starting from 230 C, although sometimes it is stable up to 500 C in different samples. Both centers have spectral-kinetic properties very unusual for mineral luminescence, which in combination with extremely low impurity concentrations, prevent their identification with specific impurity related emission. The most likely explanation of these observations may be the presence of radiation-induced luminescence centers. The long violet afterglow is evidently connected with trapped charge carrier liberation, with their subsequent migration through the valence band and ultimate recombination with a radiation-induced center responsible for the unusual violet luminescence.

Kinetic energy dissipation in heavy-ion collisions

International Nuclear Information System (INIS)

Fedotov, S.I.; Jolos, R.V.; Kartavenko, V.G.

1979-01-01

Kinetic energy dissipation mechanism is considered in deep inelastic heavy-ion collisions. It is shown that the significant part of the kinetic energy loss can be explained by the excitation of the nuclear matter multipole vibrations. The main contribution of the energy dissipation is given by the time dependent heavy-ion interaction potential renormalized due to the nuclear excitations, rather than by the velocity proportional frictional forces

Effect of secondary structure on the thermodynamics and kinetics of PNA hybridization to DNA hairpins

DEFF Research Database (Denmark)

Kushon, S A; Jordan, J P; Seifert, J L

2001-01-01

The binding of a series of PNA and DNA probes to a group of unusually stable DNA hairpins of the tetraloop motif has been observed using absorbance hypochromicity (ABS), circular dichroism (CD), and a colorimetric assay for PNA/DNA duplex detection. These results indicate that both stable PNA...... structures in both target and probe molecules are shown to depress the melting temperatures and free energies of the probe-target duplexes. Kinetic analysis of hybridization yields reaction rates that are up to 160-fold slower than hybridization between two unstructured strands. The thermodynamic and kinetic...

Explaining the atypical reaction profiles of heme enzymes with a novel mechanistic hypothesis and kinetic treatment.

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Kelath Murali Manoj

Full Text Available Many heme enzymes show remarkable versatility and atypical kinetics. The fungal extracellular enzyme chloroperoxidase (CPO characterizes a variety of one and two electron redox reactions in the presence of hydroperoxides. A structural counterpart, found in mammalian microsomal cytochrome P450 (CYP, uses molecular oxygen plus NADPH for the oxidative metabolism (predominantly hydroxylation of substrate in conjunction with a redox partner enzyme, cytochrome P450 reductase. In this study, we employ the two above-mentioned heme-thiolate proteins to probe the reaction kinetics and mechanism of heme enzymes. Hitherto, a substrate inhibition model based upon non-productive binding of substrate (two-site model was used to account for the inhibition of reaction at higher substrate concentrations for the CYP reaction systems. Herein, the observation of substrate inhibition is shown for both peroxide and final substrate in CPO catalyzed peroxidations. Further, analogy is drawn in the "steady state kinetics" of CPO and CYP reaction systems. New experimental observations and analyses indicate that a scheme of competing reactions (involving primary product with enzyme or other reaction components/intermediates is relevant in such complex reaction mixtures. The presence of non-selective reactive intermediate(s affords alternate reaction routes at various substrate/product concentrations, thereby leading to a lowered detectable concentration of "the product of interest" in the reaction milieu. Occam's razor favors the new hypothesis. With the new hypothesis as foundation, a new biphasic treatment to analyze the kinetics is put forth. We also introduce a key concept of "substrate concentration at maximum observed rate". The new treatment affords a more acceptable fit for observable experimental kinetic data of heme redox enzymes.

Unusual manifestations of secondary urothelial carcinoma

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Chaohui Lisa Zhao

2016-03-01

Full Text Available High-grade papillary urothelial carcinoma regularly invades the bladder wall, adjacent prostate, seminal vesicles, ureters, vagina, rectum, retroperitoneum, and regional lymph nodes. In advanced stages, it may disseminate to the liver, lungs, and bone marrow. On rare occasions, unusual metastatic foci like skin have been reported. The incidence of urothelial carcinoma has increased with associated rise in variants of urothelial carcinoma and unusual metastatic foci. It is imperative that urologists and pathologists are aware of the unusual variants and unusual metastatic locations to expedite the diagnostic process. Hereby we report an unusual case of secondary involvement of spinal nerve by conventional urothelial carcinoma. Also a second case of rhabdoid variant of urothelial carcinoma showing synchronous involvement of bladder and subcutaneous tissue of upper extremity is presented.

Unusual headache syndromes.

Science.gov (United States)

Queiroz, Luiz P

2013-01-01

Some headache syndromes have few cases reported in the literature. Their clinical characteristics, pathogenesis, and treatment may have not been completely defined. They may not actually be uncommon but rather under-recognized and/or underreported. A literature review of unusual headache syndromes, searching PubMed and ISI Web of Knowledge, was performed. After deciding which disorders to study, relevant publications in scientific journals, including original articles, reviews, meeting abstracts, and letters or correspondences to the editors were searched. This paper reviewed the clinical characteristics, the pathogenesis, the diagnosis, and the treatment of five interesting and unusual headache syndromes: exploding head syndrome, red ear syndrome, neck-tongue syndrome, nummular headache, and cardiac cephalgia. Recognizing some unusual headaches, either primary or secondary, may be a challenge for many non-headache specialist physicians. It is important to study them because the correct diagnosis may result in specific treatments that may improve the quality of life of these patients, and this can even be life saving. © 2013 American Headache Society.

DISCOVERY OF AN UNUSUALLY RED L-TYPE BROWN DWARF

International Nuclear Information System (INIS)

Gizis, John E.; Castro, Philip J.; Faherty, Jacqueline K.; Liu, Michael C.; Aller, Kimberly M.; Shaw, John D.; Vrba, Frederick J.; Harris, Hugh C.; Deacon, Niall R.

2012-01-01

We report the discovery of an unusually red brown dwarf found in a search for high proper motion objects using WISE and 2MASS data. WISEP J004701.06+680352.1 is moving at 0.''44 yr –1 and lies relatively close to the Galactic plane (b = 5. 0 2). Near-infrared photometry and spectroscopy reveals that this is one of the reddest (2MASS J – K s 2.55 ± 0.08 mag) field L dwarfs yet detected, making this object an important member of the class of unusually red L dwarfs. We discuss evidence for thick condensate clouds and speculate on the age of the object. Although models by different research groups agree that thick clouds can explain the red spectrum, they predict dramatically different effective temperatures, ranging from 1100 K to 1600 K. This brown dwarf is well suited for additional studies of extremely dusty substellar atmospheres because it is relatively bright (K s = 13.05 ± 0.03 mag), which should also contribute to an improved understanding of young gas-giant planets and the transition between L and T brown dwarfs.

Practical steady-state enzyme kinetics.

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Lorsch, Jon R

2014-01-01

Enzymes are key components of most biological processes. Characterization of enzymes is therefore frequently required during the study of biological systems. Steady-state kinetics provides a simple and rapid means of assessing the substrate specificity of an enzyme. When combined with site-directed mutagenesis (see Site-Directed Mutagenesis), it can be used to probe the roles of particular amino acids in the enzyme in substrate recognition and catalysis. Effects of interaction partners and posttranslational modifications can also be assessed using steady-state kinetics. This overview explains the general principles of steady-state enzyme kinetics experiments in a practical, rather than theoretical, way. Any biochemistry textbook will have a section on the theory of Michaelis-Menten kinetics, including derivations of the relevant equations. No specific enzymatic assay is described here, although a method for monitoring product formation or substrate consumption over time (an assay) is required to perform the experiments described. © 2014 Elsevier Inc. All rights reserved.

48 CFR 32.114 - Unusual contract financing.

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2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 32.114 Unusual contract financing. Any contract financing arrangement that deviates from this part is unusual contract financing...

48 CFR 432.114 - Unusual contract financing.

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2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 432.114 Unusual contract financing. The HCA is authorized to approve unusual contract financing. The signed determination and finding...

48 CFR 1332.114 - Unusual contract financing.

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2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 1332.114 Unusual contract financing. The designee authorized to approve unusual contract financing arrangements is set forth in CAM...

Kinetic modeling of cell metabolism for microbial production.

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Costa, Rafael S; Hartmann, Andras; Vinga, Susana

2016-02-10

Kinetic models of cellular metabolism are important tools for the rational design of metabolic engineering strategies and to explain properties of complex biological systems. The recent developments in high-throughput experimental data are leading to new computational approaches for building kinetic models of metabolism. Herein, we briefly survey the available databases, standards and software tools that can be applied for kinetic models of metabolism. In addition, we give an overview about recently developed ordinary differential equations (ODE)-based kinetic models of metabolism and some of the main applications of such models are illustrated in guiding metabolic engineering design. Finally, we review the kinetic modeling approaches of large-scale networks that are emerging, discussing their main advantages, challenges and limitations. Copyright © 2015 Elsevier B.V. All rights reserved.

Catastrophic Disruption Threshold and Maximum Deflection from Kinetic Impact

Science.gov (United States)

Cheng, A. F.

2017-12-01

The use of a kinetic impactor to deflect an asteroid on a collision course with Earth was described in the NASA Near-Earth Object Survey and Deflection Analysis of Alternatives (2007) as the most mature approach for asteroid deflection and mitigation. The NASA DART mission will demonstrate asteroid deflection by kinetic impact at the Potentially Hazardous Asteroid 65803 Didymos in October, 2022. The kinetic impactor approach is considered to be applicable with warning times of 10 years or more and with hazardous asteroid diameters of 400 m or less. In principle, a larger kinetic impactor bringing greater kinetic energy could cause a larger deflection, but input of excessive kinetic energy will cause catastrophic disruption of the target, leaving possibly large fragments still on collision course with Earth. Thus the catastrophic disruption threshold limits the maximum deflection from a kinetic impactor. An often-cited rule of thumb states that the maximum deflection is 0.1 times the escape velocity before the target will be disrupted. It turns out this rule of thumb does not work well. A comparison to numerical simulation results shows that a similar rule applies in the gravity limit, for large targets more than 300 m, where the maximum deflection is roughly the escape velocity at momentum enhancement factor β=2. In the gravity limit, the rule of thumb corresponds to pure momentum coupling (μ=1/3), but simulations find a slightly different scaling μ=0.43. In the smaller target size range that kinetic impactors would apply to, the catastrophic disruption limit is strength-controlled. A DART-like impactor won't disrupt any target asteroid down to significantly smaller size than the 50 m below which a hazardous object would not penetrate the atmosphere in any case unless it is unusually strong.

Fibrolamellar hepatocellular carcinoma with ovarian metastasis - an unusual presentation.

Science.gov (United States)

Ciurea, Silviu Horia; Matei, Emil; Stănescu, CodruŢ Silvian; Lupescu, Ioana Gabriela; Boroş, Mirela; Herlea, Vlad; Luca, Niculina Ioana; DorobanŢu, Bogdan Mihail

2017-01-01

Fibrolamellar carcinoma (FLC) has been considered a distinct clinical entity vs. hepatocellular carcinoma, with respect to its epidemiology, etiology, and prognosis. We describe the unusual case of a 23-year-old female patient with FLC and ovarian (Krukenberg) and peritoneal metastases, clinically mimicking an ovarian carcinoma. Multiple recurrences occurred despite initial R0 resection and chemotherapy, requiring surgical treatment. The patient survived five years and died from generalized disease. The particularities of our case are discussed by comparison with the other two similar cases and other date from the literature. To our knowledge, the ovarian involvement encountered in our case is the third case published in literature, being explained by the superficial location of the liver tumor.

Gastrointestinal leiomyosarcoma - unusual sites: Esophagus, colon and porta hepatis

International Nuclear Information System (INIS)

Balthazar, E.J.

1981-01-01

This paper is based on a retrospective analysis of the radiologic findings of 6 newly proven cases of primary gastrointestinal leiomyosarcomas located in unusual sites. The radiographic and angiographic features of esophageal, colonic, and porta hepatis leiomyosarcomas are described and illustrated. General background information together with a brief review of the literature regarding these lesions are provided. The difficulties encountered in the preoperative diagnosis are explained by the protean and nonspecific clinical and radiographic features of many of these tumors. In addition, although myomatous tumors of the liver and porta hepatis are angiogaphically hypervascular, similar tumors of the colon are slight to moderately vascular, and tumors of the esophagus are avascular. (orig.)

Kinetically-controlled template-free synthesis of hollow silica micro-/nanostructures with unusual morphologies

International Nuclear Information System (INIS)

Zhang, An-Qi; Li, Hui-Jun; Qian, Dong-Jin; Chen, Meng

2014-01-01

We report a kinetically-controlled template-free room-temperature production of hollow silica materials with various novel morphologies, including tubes, crutches, ribbons, bundles and bells. The obtained products, which grew in a well-controlled manner, were monodispersed in shape and size. The role of ammonia, sodium citrate, polyvinylpyrrolidone, chloroauric acid and NaCl in shape control is discussed in detail. The oriented growth of these micro-/nanostructures directed by reverse micelles followed a solution–solution–solid (SSS) mechanism, similar to the classic vapor–liquid–solid mechanism. The evolution processes of silica rods, tubes, crutches, bundles and bells were recorded using transmission electron microscopy to prove the SSS mechanism. (paper)

Environment-sensitive quinolone demonstrating long-lived fluorescence and unusually slow excited-state intramolecular proton transfer kinetics

Czech Academy of Sciences Publication Activity Database

Zamotaiev, O. M.; Shvadchak, Volodymyr; Sych, T. P.; Melnychuk, N. A.; Yushchenko, Dmytro A.; Mely, Y.; Pivovarenko, V. G.

2016-01-01

Roč. 4, č. 3 (2016), č. článku 034004. ISSN 2050-6120 Institutional support: RVO:61388963 Keywords : quinolone * fluorescent probes * local polarity * hydration * excited-state intramolecular proton transfer * kinetics Subject RIV: CC - Organic Chemistry Impact factor: 2.656, year: 2016

Kinetic inductance of HTS resonators at various microwave power levels

International Nuclear Information System (INIS)

Srivastava, G.P.; Jacob, Mohan V.

1997-01-01

Microwave superconducting devices show a drastic deterioration in its performance at high microwave power levels. The flux penetration through the weak links increases the quasiparticle concentration which results in the increase of penetration depth and hence the kinetic inductance. We have modeled an expression to find the kinetic inductance at various RF power levels. The results show that the change in kinetic inductance is proportional to be square of the applied field. This model can explain the reported experimental results at and below the intermediate power levels. (author)

On the kinetics of body versus end evaporation and addition of supramolecular polymers

NARCIS (Netherlands)

Tiwari, Nitin S.; van der Schoot, Paul

2017-01-01

Abstract.: The kinetics of the self-assembly of supramolecular polymers is dictated by how monomers, dimers, trimers etc., attach to and detach from each other. It is for this reasons that researchers have proposed a plethora of pathways to explain the kinetics of various self-assembling

On the kinetics of body versus end evaporation and addition of supramolecular polymers

NARCIS (Netherlands)

Tiwari, N.; van der Schoot, P.P.A.M.

2017-01-01

The kinetics of the self-assembly of supramolecular polymers is dictated by how monomers, dimers, trimers etc., attach to and detach from each other. It is for this reasons that researchers have proposed a plethora of pathways to explain the kinetics of various self-assembling supramolecules,

Simplified kinetic models of methanol oxidation on silver

DEFF Research Database (Denmark)

Andreasen, A.; Lynggaard, H.; Stegelmann, C.

2005-01-01

Recently the authors developed a microkinetic model of methanol oxidation on silver [A. Andreasen, H. Lynggaard, C. Stegelmann, P. Stoltze, Surf. Sci. 544 (2003) 5-23]. The model successfully explains both surface science experiments and kinetic experiments at industrial conditions applying...

Unusual Fears in Children with Autism

Science.gov (United States)

Mayes, Susan Dickerson; Calhoun, Susan L.; Aggarwal, Richa; Baker, Courtney; Mathapati, Santosh; Molitoris, Sarah; Mayes, Rebecca D.

2013-01-01

Unusual fears have long been recognized as common in autism, but little research exists. In our sample of 1033 children with autism, unusual fears were reported by parents of 421 (41%) of the children, representing 92 different fears. Many additional children had common childhood fears (e.g., dogs, bugs, and the dark). More than half of children…

Unusual radiological findings of adult-onset pulmonary tuberculosis

International Nuclear Information System (INIS)

Lee, Yong Chul; Lee, Jong Beum; Kim, Sue Hyun

1987-01-01

Usual chest radiographic findings in pulmonary tuberculosis are well described in radiologic literatures for both primary and postprimary phases of disease. During the last decade, many authors have enumerated the unusual manifestations of pulmonary tuberculosis in adult population. These unusual findings usually have been involved in the frequent failure of both radiologist and clinician to recognize that tuberculosis could be the cause of a abnormal chest radiograph in patients who are finally and surprisingly proven to have tuberculosis. Authors have evaluated 249 patients who were admitted and newly proven to have adult-onset pulmonary tuberculosis at Chung-Ang University Hospital from January, 1985 to December, 1986. Unusual findings were noted in 76 (30.5%) of the 249 patients with adult-onset pulmonary tuberculosis. These unusual findings most frequently could be seen in 3rd decades and showed no sex difference in incidence. A broad spectrum of abnormal findings including usual and unusual abnormalities were procedure by adult-onset pulmonary tuberculosis. The unusual radiographic findings were arbitrarily classified. Pleural effusion without parenchymal disease (10.0%), unusual location of infiltrate (5.6%) and atelectasis (3.2%) were relatively common. Hilar and / or mediastinal lymphnode enlargement (1.6%), cavity without parenchymal infiltrates (1.6%), septic lung-like infiltrates (1.6%), completely clear lungs (1.2%), miliary infiltrates (1.2%), fibrocalcific scar-like infiltrates (1.2%), masslike density (1.2%) and rheumatoid lung-like infiltrates (1.2%) were occasionally noted. Pneumothorax without parenchymal disease (0.4%) and bron chocutaneous fistula (0.4%) are. The recognition of these unusual findings could further improve the detection and diagnosis of adult-onset pulmonary tuberculosis

Myasthenia Gravis: Unusual Presentations and Diagnostic Pitfalls.

Science.gov (United States)

Rodolico, Carmelo; Parisi, Daniela; Portaro, Simona; Biasini, Fiammetta; Sinicropi, Stefano; Ciranni, Annamaria; Toscano, Antonio; Messina, Sonia; Musumeci, Olimpia; Vita, Giuseppe; Girlanda, Paolo

2016-08-30

Myasthenia gravis (MG) is an autoimmune disorder presenting with fluctuating, fatigable muscle weakness. Initial symptoms classically involve ocular and proximal limb muscles. Rarely, MG may onset with unusual features, so it can be misdiagnosed with other neuromuscular diseases. To describe unusual and atypical presentations of MG in a large cohort of patients, considering and discussing diagnostic difficulties and pitfalls. We report on 21 out of 508 MG patients, coming to our department in the last 27 years and presenting with atypical or unusual features. The diagnosis was achieved performing a careful clinical examination, a proper neurophysiological assessment, the neostigmine test, the AChR and MuSK antibodies assay and chest CT-scan. Patients with atypical/unusual MG onset were the 4.4% of all MG patients population. We describe seven different clinical categories: asymmetric distal upper limbs weakness, foot drop, isolated triceps brachii weakness and foot drop, post exertional axial weakness with dropped head, acute facial dyplegia, limb-girdle MG and MG with sudden lower limbs weakness and recurrent falls. Atypical and unusual presentations may increase the risk to misdiagnose or delay MG diagnosis. Isolated limb-girdle presentation is the most frequent atypical form in our series.

A barrier on the public communication of nuclear technology. How to interpret reactor kinetics

International Nuclear Information System (INIS)

Yamamoto, Akio

2007-01-01

Reactor kinetics is very important to explain the safety of nuclear reactors. However, its description is somewhat complicated and not intuitive. In order to give more intuitive explanation for reactor kinetics, some metaphors that try to capture the feature of reactor behavior are discussed. (author)

Vector parametrization, partial angular momenta and unusual commutation relations in physics

International Nuclear Information System (INIS)

Gatti, Fabien; Nauts, Andre

2003-01-01

When studying an N-particle system by means of N-1 vectors i.e., by means of a vector parametrization, one unavoidably comes across several angular momenta: not only the total angular momentum of the system but also the various partial angular momenta corresponding to the motion of the various vectors. All these momenta can, in addition, be referred to a variety of reference frames. The use of vector parametrizations and partial angular momenta in physics greatly simplifies the classical as well as quantum expressions of the kinetic energy. The present paper is devoted to a detailed and rigorous study of the partial angular momenta and the various commutation relations they satisfy, in particular the unusual commutation relations whose origin is traced back to the very structure of the coordinate changes used to define the Body-Fixed (BF) frames. The direct quantization of the classical expressions of the kinetic energy obtained in the context of various vector parametrizations is also given in detail. It turns out to be an efficient extension of well-known quantization procedures to the case where supernumerary quasi-momenta are used. As an illustration, the case of a four-particle system is treated in detail for a particular choice of the BF frames. Finally, the analogies between the classical and quantum approaches are emphasized

Kinetic k-essence ghost dark energy model

International Nuclear Information System (INIS)

Rozas-Fernández, Alberto

2012-01-01

A ghost dark energy model has been recently put forward to explain the current accelerated expansion of the Universe. In this model, the energy density of ghost dark energy, which comes from the Veneziano ghost of QCD, is proportional to the Hubble parameter, ρ D =αH. Here α is a constant of order Λ QCD 3 where Λ QCD ∼100 MeV is the QCD mass scale. We consider a connection between ghost dark energy with/without interaction between the components of the dark sector and the kinetic k-essence field. It is shown that the cosmological evolution of the ghost dark energy dominated Universe can be completely described a kinetic k-essence scalar field. We reconstruct the kinetic k-essence function F(X) in a flat Friedmann-Robertson-Walker Universe according to the evolution of ghost dark energy density.

48 CFR 632.114 - Unusual contract financing.

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2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Unusual contract financing. 632.114 Section 632.114 Federal Acquisition Regulations System DEPARTMENT OF STATE GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 632.114 Unusual contract financing. The...

48 CFR 2432.114 - Unusual contract financing.

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2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Unusual contract financing... DEVELOPMENT GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 2432.114 Unusual contract financing. The Senior Procurement Executive is the agency head for the purpose of...

Unique effects of microwave heating on polymerization kinetics of poly(methyl methacrylate) composites

Energy Technology Data Exchange (ETDEWEB)

Spasojević, Pavle [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Jovanović, Jelena, E-mail: jelenaj@ffh.bg.ac.rs [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11001 Belgrade (Serbia); Adnadjevic, Borivoj [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11001 Belgrade (Serbia)

2013-09-16

The effects of heating mode (conventional and microwave) on the kinetics of isothermal polymerization of MMA composite materials were investigated. Isothermal kinetics curves at temperature range from 343 K to 363 K for both conventional (CH) and microwave heating (MWH) were determined. It was found that the polymerization of MMA composite materials was kinetically elementary reaction for both CH and MWH. The kinetics of CH polymerization can be described by the model of phase-boundary controlled process (contracting volume), whereas the kinetics of MWH polymerization can be described by the model of first-order chemical reaction. The kinetics parameters (E{sub a} and ln A) of the polymerization under microwave heating are lower than for conventional heating. The established decreases in the activation energy and pre-exponential factor under the MWH compared to the CH is explained with the increase in the energy of ground vibrational level of the C–O valence vibrations (ν = 987 cm{sup −1}) in methyl methacrylate molecule and with the decrease in its anharmonicity factor which is caused with the selective resonant transfer of energy from the energetic reservoir to the oscillators in methyl methacrylate molecules. - Graphical abstract: Display Omitted - Highlights: • The MWH speeds the MMA material polymerization and changes the kinetics model. • A novel concept of MWH action based on activation complexes formation is presented. • The Selective Energy Transfer model is used to explain the effects of MWH. • The kinetics parameters under MWH are lower than for CH. • The activation energy for both MWH and CH polymerization is quantized.

Unusual event report from Oskarshamn

International Nuclear Information System (INIS)

1996-01-01

The title of the report was intended to reflect the cause of the shutdown and the report to be regarded as a summary of the deficiencies that had been revealed and remedied. No single deficiency was regarded as reportable as an unusual event, but taken together the identified deficiencies deviated from the assumed safety level to the extent that it should be reported. The unusual event report refers to two main documents presenting measures taken to return to reported safety level, one concerning technical and one organizational measures

Kinetic, stereochemical, and molecular association factors in the hydralumination of group IV subtituted alkynes. The role of p/sub π/-d/sub π/ conjugation in the addition of diisobutylaluminum hydride to trimethyl(phenylethynyl)silane

International Nuclear Information System (INIS)

Eisch, J.J.; Rhee, S.G.

1975-01-01

The kinetic, stereochemistry, and molecular association factors for the addition of diisobutylaluminum hydride to trimethyl(phenylethynyl)silane were studied in the temperature range of -10 to 38 0 . Hydralumination was found to have a kinetic true order of essentially one in the alkyne and one-third in the hydride. Although the trans adduct is the predominating product (approximately 99 percent) after completion of the hydralumination, the variation of the proportion of cis adduct and the initial rate law are consistent with a kinetically controlled cis hydralumination by monomeric R 2 'AlH, followed by a rapid isomerization to the trans adduct. The trans adduct formed a complex with l equivalent to the hydride. This complexation had to be taken into account, in order to explain the observed rate retardation and to obtain satisfactory integrated rate expressions for hydraluminations monitored to high conversion. Since in hydralumination this silylacetylene shows a stereospecificity and regiospecificity exactly opposite that of tert-butyl(phenyl)acetylene, as well as a heightened reactivity, a critical consideration of possible p/sub π/--d/sub π/ electronic effects was undertaken. The unusually facile isomerization of the resulting silyl-substituted vinylalanes, however, does seem more persuasive evidence for a p/sub π/--d/sub π/ effect, which promotes isomerization by electrophilic attack of R 2 'AlH on the carbon α to the Me 3 Si group. (U.S.)

48 CFR 2832.114 - Unusual contract financing.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Unusual contract financing... Contracting Requirements CONTRACT FINANCING Non-Commercial Item Purchase Financing 2832.114 Unusual contract financing. The HCA, or designee at a level not lower than the BPC, is the official authorized to approve...

Bench-scale Kinetics Study of Mercury Reactions in FGD Liquors

Energy Technology Data Exchange (ETDEWEB)

Gary Blythe; John Currie; David DeBerry

2008-03-31

This document is the final report for Cooperative Agreement DE-FC26-04NT42314, 'Kinetics Study of Mercury Reactions in FGD Liquors'. The project was co-funded by the U.S. DOE National Energy Technology Laboratory and EPRI. The objective of the project has been to determine the mechanisms and kinetics of the aqueous reactions of mercury absorbed by wet flue gas desulfurization (FGD) systems, and develop a kinetics model to predict mercury reactions in wet FGD systems. The model may be used to determine optimum wet FGD design and operating conditions to maximize mercury capture in wet FGD systems. Initially, a series of bench-top, liquid-phase reactor tests were conducted and mercury species concentrations were measured by UV/visible light spectroscopy to determine reactant and byproduct concentrations over time. Other measurement methods, such as atomic absorption, were used to measure concentrations of vapor-phase elemental mercury, that cannot be measured by UV/visible light spectroscopy. Next, a series of bench-scale wet FGD simulation tests were conducted. Because of the significant effects of sulfite concentration on mercury re-emission rates, new methods were developed for operating and controlling the bench-scale FGD experiments. Approximately 140 bench-scale wet FGD tests were conducted and several unusual and pertinent effects of process chemistry on mercury re-emissions were identified and characterized. These data have been used to develop an empirically adjusted, theoretically based kinetics model to predict mercury species reactions in wet FGD systems. The model has been verified in tests conducted with the bench-scale wet FGD system, where both gas-phase and liquid-phase mercury concentrations were measured to determine if the model accurately predicts the tendency for mercury re-emissions. This report presents and discusses results from the initial laboratory kinetics measurements, the bench-scale wet FGD tests, and the kinetics modeling

Steady-state kinetics of substrate binding and iron release in tomato ACC oxidase.

Science.gov (United States)

Thrower, J S; Blalock, R; Klinman, J P

2001-08-14

1-Aminocyclopropane-1-carboxylate oxidase (ACC oxidase) catalyzes the last step in the biosynthetic pathway of the plant hormone, ethylene. This unusual reaction results in the oxidative ring cleavage of 1-aminocyclopropane carboxylate (ACC) into ethylene, cyanide, and CO2 and requires ferrous ion, ascorbate, and molecular oxygen for catalysis. A new purification procedure and assay method have been developed for tomato ACC oxidase that result in greatly increased enzymatic activity. This method allowed us to determine the rate of iron release from the enzyme and the effect of the activator, CO2, on this rate. Initial velocity studies support an ordered kinetic mechanism where ACC binds first followed by O2; ascorbate can bind after O2 or possibly before ACC. This kinetic mechanism differs from one recently proposed for the ACC oxidase from avocado.

Unusual raptor nests around the world

Science.gov (United States)

Ellis, D.H.; Craig, T.; Craig, E.; Postupalsky, S.; LaRue, C.T.; Nelson, R.W.; Anderson, D.W.; Henny, C.J.; Watson, J.; Millsap, B.A.; Dawson, J.W.; Cole, K.L.; Martin, E.M.; Margalida, A.; Kung, P.

2009-01-01

From surveys in many countries, we report raptors using unusual nesting materials (e.g., paper money, rags, metal, antlers, and large bones) and unusual nesting situations. For example, we documented nests of Steppe Eagles Aquila nipalensis and Upland Buzzards Buteo hemilasius on the ground beside well-traveled roads, Saker Falcon Falco cherrug eyries in attics and a cistern, and Osprey Pandion haliaetus nests on the masts of boats and on a suspended automobile. Other records include a Golden Eagle A. chrysaetos nest 7.0 m in height, believed to be the tallest nest ever described, and, for the same species, we report nesting in rudimentary nests. Some nest sites are within a few meters of known predators or competitors. These unusual observations may be important in revealing the plasticity of a species' behavioral repertoire. ?? 2009 The Raptor Research Foundation, Inc.

Rheological Characterization of Unusual DWPF Slurry Samples

International Nuclear Information System (INIS)

Koopman, D. C.

2005-01-01

A study was undertaken to identify and clarify examples of unusual rheological behavior in Defense Waste Processing Facility (DWPF) simulant slurry samples. Identification was accomplished by reviewing sludge, Sludge Receipt and Adjustment Tank (SRAT) product, and Slurry Mix Evaporator (SME) product simulant rheological results from the prior year. Clarification of unusual rheological behavior was achieved by developing and implementing new measurement techniques. Development of these new methods is covered in a separate report, WSRC-TR-2004-00334. This report includes a review of recent literature on unusual rheological behavior, followed by a summary of the rheological measurement results obtained on a set of unusual simulant samples. Shifts in rheological behavior of slurries as the wt. % total solids changed have been observed in numerous systems. The main finding of the experimental work was that the various unusual DWPF simulant slurry samples exhibit some degree of time dependent behavior. When a given shear rate is applied to a sample, the apparent viscosity of the slurry changes with time rather than remaining constant. These unusual simulant samples are more rheologically complex than Newtonian liquids or more simple slurries, neither of which shows significant time dependence. The study concludes that the unusual rheological behavior that has been observed is being caused by time dependent rheological properties in the slurries being measured. Most of the changes are due to the effect of time under shear, but SB3 SME products were also changing properties while stored in sample bottles. The most likely source of this shear-related time dependence for sludge is in the simulant preparation. More than a single source of time dependence was inferred for the simulant SME product slurries based on the range of phenomena observed. Rheological property changes were observed on the time-scale of a single measurement (minutes) as well as on a time scale of hours

The Application of Biomimicry in Kinetic Facades

Directory of Open Access Journals (Sweden)

Wijdan Deyaa Abdul Jalil

2016-10-01

Full Text Available Biomimicry, as a way of thinking to go back to nature for inspiration, has its impact on many contemporary technological achievements. Some of them are used to design and construct kinetic facades in architecture, because of the importance role of facades in reducing sun radiation, that enter the building through using shading systems and components. In light of this, research problem is determined: "Do technologies which are inspired by biomimicry effect shading in kinetic facades through its characteristics in materials and the mechanics. So the research identifies its goal as: "To identify the types of kinetic facades in buildings and their characteristics as materials and shading mechanism associated with the biomimicry. The research explains the basic types of kinetic facades depending on the technology and materials used to provide the possibility of reducing solar radiation that enters the building. It also compares the case studies which have been chosen in their inspiration concept from biological world, which reflect on the system used of protecting against sun and reducing energy consumption as the designer teams suggest. The research concluded that kinetic façade which is depending on smart materials is self-responding and don't need energy to operate, so it is better in reducing consumption of energy.

Improvement of neutron kinetics module in TRAC-BF1code: one-dimensional nodal collocation method

Energy Technology Data Exchange (ETDEWEB)

Jambrina, Ana; Barrachina, Teresa; Miro, Rafael; Verdu, Gumersindo, E-mail: ajambrina@iqn.upv.es, E-mail: tbarrachina@iqn.upv.es, E-mail: rmiro@iqn.upv.es, E-mail: gverdu@iqn.upv.es [Universidade Politecnica de Valencia (UPV), Valencia (Spain); Soler, Amparo, E-mail: asoler@iberdrola.es [SEA Propulsion S.L., Madrid (Spain); Concejal, Alberto, E-mail: acbe@iberdrola.es [Iberdrola Ingenieria y Construcion S.A.U., Madrid (Spain)

2013-07-01

The TRAC-BF1 one-dimensional kinetic model is a formulation of the neutron diffusion equation in the two energy groups' approximation, based on the analytical nodal method (ANM). The advantage compared with a zero-dimensional kinetic model is that the axial power profile may vary with time due to thermal-hydraulic parameter changes and/or actions of the control systems but at has the disadvantages that in unusual situations it fails to converge. The nodal collocation method developed for the neutron diffusion equation and applied to the kinetics resolution of TRAC-BF1 thermal-hydraulics, is an adaptation of the traditional collocation methods for the discretization of partial differential equations, based on the development of the solution as a linear combination of analytical functions. It has chosen to use a nodal collocation method based on a development of Legendre polynomials of neutron fluxes in each cell. The qualification is carried out by the analysis of the turbine trip transient from the NEA benchmark in Peach Bottom NPP using both the original 1D kinetics implemented in TRAC-BF1 and the 1D nodal collocation method. (author)

Inverse temperature dependence of reverse gate leakage current in AlGaN/GaN HEMT

International Nuclear Information System (INIS)

Kaushik, J K; Balakrishnan, V R; Muralidharan, R; Panwar, B S

2013-01-01

The experimentally observed inverse temperature dependence of the reverse gate leakage current in AlGaN/GaN HEMT is explained using a virtual gate trap-assisted tunneling model. The virtual gate is formed due to the capture of electrons by surface states in the vicinity of actual gate. The increase and decrease in the length of the virtual gate with temperature due to trap kinetics are used to explain this unusual effect. The simulation results have been validated experimentally. (paper)

Kinetics model development of cocoa bean fermentation

Science.gov (United States)

Kresnowati, M. T. A. P.; Gunawan, Agus Yodi; Muliyadini, Winny

2015-12-01

Although Indonesia is one of the biggest cocoa beans producers in the world, Indonesian cocoa beans are oftenly of low quality and thereby frequently priced low in the world market. In order to improve the quality, adequate post-harvest cocoa processing techniques are required. Fermentation is the vital stage in series of cocoa beans post harvest processing which could improve the quality of cocoa beans, in particular taste, aroma, and colours. During the fermentation process, combination of microbes grow producing metabolites that serve as the precursors for cocoa beans flavour. Microbial composition and thereby their activities will affect the fermentation performance and influence the properties of cocoa beans. The correlation could be reviewed using a kinetic model that includes unstructured microbial growth, substrate utilization and metabolic product formation. The developed kinetic model could be further used to design cocoa bean fermentation process to meet the expected quality. Further the development of kinetic model of cocoa bean fermentation also serve as a good case study of mixed culture solid state fermentation, that has rarely been studied. This paper presents the development of a kinetic model for solid-state cocoa beans fermentation using an empirical approach. Series of lab scale cocoa bean fermentations, either natural fermentations without starter addition or fermentations with mixed yeast and lactic acid bacteria starter addition, were used for model parameters estimation. The results showed that cocoa beans fermentation can be modelled mathematically and the best model included substrate utilization, microbial growth, metabolites production and its transport. Although the developed model still can not explain the dynamics in microbial population, this model can sufficiently explained the observed changes in sugar concentration as well as metabolic products in the cocoa bean pulp.

An Unusual Bone Loss Around Implants

Directory of Open Access Journals (Sweden)

Amirreza Rokn

2013-01-01

Full Text Available AbstractPre-implant disease is an inflammatory process, which can affect the surrounding tissues of a functional Osseointegrated implant that is usually as a result of a disequilibrium between the micro-flora and the body defense system.This case reports a 57 years old male with unusual bone loss around dental implants.This was an unusual case of peri-implantitis which occurred only in the implants on one side of the mouth although they all were unloaded implants.

Real-time relaxation and kinetics in hot scalar QED: Landau damping

International Nuclear Information System (INIS)

Boyanovsky, D.; Vega, H.J. de; Holman, R.; Kumar, S.P.; Pisarski, R.D.

1998-01-01

The real time evolution of non-equilibrium expectation values with soft length scales ∼k -1 >(eT) -1 is solved in hot scalar electrodynamics, with a view towards understanding relaxational phenomena in the QGP and the electroweak plasma. We find that the gauge invariant non-equilibrium expectation values relax via power laws to asymptotic amplitudes that are determined by the quasiparticle poles. The long time relaxational dynamics and relevant time scales are determined by the behavior of the retarded self-energy not at the small frequencies, but at the Landau damping thresholds. This explains the presence of power laws and not of exponential decay. In the process we rederive the HTL effective action using non-equilibrium field theory. Furthermore we obtain the influence functional, the Langevin equation and the fluctuation-dissipation theorem for the soft modes, identifying the correlators that emerge in the classical limit. We show that a Markovian approximation fails to describe the dynamics both at short and long times. We find that the distribution function for soft quasiparticles relaxes with a power law through Landau damping. We also introduce a novel kinetic approach that goes beyond the standard Boltzmann equation by incorporating off-shell processes and find that the distribution function for soft quasiparticles relaxes with a power law through Landau damping. We find an unusual dressing dynamics of bare particles and anomalous (logarithmic) relaxation of hard quasiparticles. copyright 1998 The American Physical Society

MODELING STYRENE HYDROGENATION KINETICS USING PALLADIUM CATALYSTS

Directory of Open Access Journals (Sweden)

G. T. Justino

Full Text Available Abstract The high octane number of pyrolysis gasoline (PYGAS explains its insertion in the gasoline pool. However, its use is troublesome due to the presence of gum-forming chemicals which, in turn, can be removed via hydrogenation. The use of Langmuir-Hinshelwood kinetic models was evaluated for hydrogenation of styrene, a typical gum monomer, using Pd/9%Nb2O5-Al2O3 as catalyst. Kinetic models accounting for hydrogen dissociative and non-dissociative adsorption were considered. The availability of one or two kinds of catalytic sites was analyzed. Experiments were carried out in a semi-batch reactor at constant temperature and pressure in the absence of transport limitations. The conditions used in each experiment varied between 16 - 56 bar and 60 - 100 ºC for pressure and temperature, respectively. The kinetic models were evaluated using MATLAB and EMSO software. Models using adsorption of hydrogen and organic molecules on the same type of site fitted the data best.

Kinetic isotope effect in the thermolysis of methylenecyclobutane

International Nuclear Information System (INIS)

Chickos, J.S.

1979-01-01

The intramolecular kinetic isotope effect for the thermolysis of equilibrated methylenecyclobutane-d 2 was investigated at 515 0 C as a function of pressure. A high-pressure value of k/sub H/k/sub D/ (ethylene/ethylene-d 2 ) = 0.9 was obtained at 13 cm of N 2 pressure. This value decreased to 0.86 at 70 μm total pressure. No intermolecular kinetic isotope effect was measured for the formation of ethylene from labeled and unlabeled methylenecyclobutane. The pressure and temperature dependence of the intramolecular kinetic isotope effect was used as evidence in establishing the inverse nature of the effect. The isotope effect observed was explained in terms of competing equilibrium and kinetic isotope effects in which the equilibrium isotope effects dominate. It was concluded on the bases of these results that an acyclic intermediate is involved in the fragmentation of methylenecyclobutane to ethylene and allene. The results also support the notion that deuterium prefers to accumulate at the methylene group with the greatest p character in the carbon--hydrogen bond. 1 figure, 4 tables

Kinetic and equilibrium aspects of adsorption and desorption of class II hydrophobins HFBI and HFBII at silicon oxynitride/water and air/water interfaces.

Science.gov (United States)

Krivosheeva, Olga; Dėdinaitė, Andra; Linder, Markus B; Tilton, Robert D; Claesson, Per M

2013-02-26

Hydrophobins are relatively small globular proteins produced by filamentous fungi. They display unusual high surface activity and are implied as mediators of attachment to surfaces, which has resulted in high scientific and technological interest. In this work we focus on kinetic and equilibrium aspects of adsorption and desorption properties of two representatives of class II hydrophobins, namely HFBI and HFBII, at a negatively charged hydrophilic solid/water interface and at the air/water interface. The layers formed at the air/liquid interface were examined in a Langmuir trough, whereas layers formed at the solid/liquid interface were studied using dual polarization interferometry (DPI) under different flow conditions. For comparison, another globular protein, lysozyme, was also investigated. It was found that both the adsorbed amount and the adsorption kinetics were different for HFBI and HFBII, and the adsorption behavior of both hydrophobins on the negatively charged surface displayed some unusual features. For instance, even though the adsorption rate for HFBI was slowed down with increasing adsorbed amount as expected from packing constraints at the interface, the adsorption kinetics curves for HFBII displayed a region indicating adsorption cooperativity. Further, it was found that hydrophobin layers formed under flow partly desorbed when the flow was stopped, and the desorption rate for HFBII was enhanced in the presence of hydrophobins in solution.

Unusual Voltage-Gated Sodium Currents as Targets for Pain.

Science.gov (United States)

Barbosa, C; Cummins, T R

2016-01-01

Pain is a serious health problem that impacts the lives of many individuals. Hyperexcitability of peripheral sensory neurons contributes to both acute and chronic pain syndromes. Because voltage-gated sodium currents are crucial to the transmission of electrical signals in peripheral sensory neurons, the channels that underlie these currents are attractive targets for pain therapeutics. Sodium currents and channels in peripheral sensory neurons are complex. Multiple-channel isoforms contribute to the macroscopic currents in nociceptive sensory neurons. These different isoforms exhibit substantial variations in their kinetics and pharmacology. Furthermore, sodium current complexity is enhanced by an array of interacting proteins that can substantially modify the properties of voltage-gated sodium channels. Resurgent sodium currents, atypical currents that can enhance recovery from inactivation and neuronal firing, are increasingly being recognized as playing potentially important roles in sensory neuron hyperexcitability and pain sensations. Here we discuss unusual sodium channels and currents that have been identified in nociceptive sensory neurons, describe what is known about the molecular determinants of the complex sodium currents in these neurons. Finally, we provide an overview of therapeutic strategies to target voltage-gated sodium currents in nociceptive neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

Science.gov (United States)

Gutmann, Bernhard; Glasnov, Toma N; Razzaq, Tahseen; Goessler, Walter; Roberge, Dominique M

2011-01-01

Summary The decomposition of 5-benzhydryl-1H-tetrazole in an N-methyl-2-pyrrolidone/acetic acid/water mixture was investigated under a variety of high-temperature reaction conditions. Employing a sealed Pyrex glass vial and batch microwave conditions at 240 °C, the tetrazole is comparatively stable and complete decomposition to diphenylmethane requires more than 8 h. Similar kinetic data were obtained in conductively heated flow devices with either stainless steel or Hastelloy coils in the same temperature region. In contrast, in a flow instrument that utilizes direct electric resistance heating of the reactor coil, tetrazole decomposition was dramatically accelerated with rate constants increased by two orders of magnitude. When 5-benzhydryl-1H-tetrazole was exposed to 220 °C in this type of flow reactor, decomposition to diphenylmethane was complete within 10 min. The mechanism and kinetic parameters of tetrazole decomposition under a variety of reaction conditions were investigated. A number of possible explanations for these highly unusual rate accelerations are presented. In addition, general aspects of reactor degradation, corrosion and contamination effects of importance to continuous flow chemistry are discussed. PMID:21647324

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

Directory of Open Access Journals (Sweden)

Dominique M. Roberge

2011-04-01

Full Text Available The decomposition of 5-benzhydryl-1H-tetrazole in an N-methyl-2-pyrrolidone/acetic acid/water mixture was investigated under a variety of high-temperature reaction conditions. Employing a sealed Pyrex glass vial and batch microwave conditions at 240 °C, the tetrazole is comparatively stable and complete decomposition to diphenylmethane requires more than 8 h. Similar kinetic data were obtained in conductively heated flow devices with either stainless steel or Hastelloy coils in the same temperature region. In contrast, in a flow instrument that utilizes direct electric resistance heating of the reactor coil, tetrazole decomposition was dramatically accelerated with rate constants increased by two orders of magnitude. When 5-benzhydryl-1H-tetrazole was exposed to 220 °C in this type of flow reactor, decomposition to diphenylmethane was complete within 10 min. The mechanism and kinetic parameters of tetrazole decomposition under a variety of reaction conditions were investigated. A number of possible explanations for these highly unusual rate accelerations are presented. In addition, general aspects of reactor degradation, corrosion and contamination effects of importance to continuous flow chemistry are discussed.

Correlation of thermodynamics and grain growth kinetics in nanocrystalline metals

International Nuclear Information System (INIS)

Song Xiaoyan; Zhang Jiuxing; Li Lingmei; Yang Keyong; Liu Guoquan

2006-01-01

We investigated the correlation of thermodynamics and grain growth kinetics of nanocrystalline metals both theoretically and experimentally. A model was developed to describe the thermodynamic properties of nanograin boundaries, which could give reliable predictions in the destabilization characteristics of nanograin structures and the slowing down of grain growth kinetics at a constant temperature. Both the temperature-varying and isothermal nanograin growth behaviors in pure nanocrystalline Co were studied to verify the thermodynamic predictions. The experimental results showing that discontinuous nanograin growth takes place at a certain temperature and grain growth rate decreases monotonically with time confirm our thermodynamics-based description of nanograin growth characteristics. Therefore, we propose a thermodynamic viewpoint to explain the deviation of grain growth kinetics in nanocrystalline metals from those of polycrystalline materials

Thermodynamic and kinetic analysis of heterogeneous photocatalysis for semiconductor systems.

Science.gov (United States)

Liu, Baoshun; Zhao, Xiujian; Terashima, Chiaki; Fujishima, Akira; Nakata, Kazuya

2014-05-21

Since the report of the Honda-Fujishima effect, heterogeneous photocatalysis has attracted much attention around the world because of its potential energy and environmental applications. Although great progresses have been made in recent years, most were focused on preparing highly-active photocatalysts and investigating visible light utilization. In fact, we are still unclear on the thermodynamic and kinetic nature of photocatalysis to date, which sometimes leads to misunderstandings for experimental results. It is timely to give a review and discussion on the thermodynamics and kinetics of photocatalysis, so as to direct future researches. However, there is an absence of a detailed review on this topic until now. In this article, we tried to review and discuss the thermodynamics and kinetics of photocatalysis. We explained the thermodynamic driving force of photocatalysis, and distinguished the functions of light and heat in photocatalysis. The Langmuir-Hinshelwood kinetic model, the ˙OH oxidation mechanism, and the direct-indirect (D-I) kinetic model were reviewed and compared. Some applications of the D-I model to study photocatalytic kinetics were also discussed. The electron transport mode and its importance in photocatalysis were investigated. Finally, the intrinsic relation between the kinetics and the thermodynamics of photocatalytic reactions was discussed.

Rate kernel theory for pseudo-first-order kinetics of diffusion-influenced reactions and application to fluorescence quenching kinetics.

Science.gov (United States)

Yang, Mino

2007-06-07

Theoretical foundation of rate kernel equation approaches for diffusion-influenced chemical reactions is presented and applied to explain the kinetics of fluorescence quenching reactions. A many-body master equation is constructed by introducing stochastic terms, which characterize the rates of chemical reactions, into the many-body Smoluchowski equation. A Langevin-type of memory equation for the density fields of reactants evolving under the influence of time-independent perturbation is derived. This equation should be useful in predicting the time evolution of reactant concentrations approaching the steady state attained by the perturbation as well as the steady-state concentrations. The dynamics of fluctuation occurring in equilibrium state can be predicted by the memory equation by turning the perturbation off and consequently may be useful in obtaining the linear response to a time-dependent perturbation. It is found that unimolecular decay processes including the time-independent perturbation can be incorporated into bimolecular reaction kinetics as a Laplace transform variable. As a result, a theory for bimolecular reactions along with the unimolecular process turned off is sufficient to predict overall reaction kinetics including the effects of unimolecular reactions and perturbation. As the present formulation is applied to steady-state kinetics of fluorescence quenching reactions, the exact relation between fluorophore concentrations and the intensity of excitation light is derived.

Unusual radiological characteristics of teratoid/rhabdoid brain tumor ...

African Journals Online (AJOL)

We report a case of atypical teratoid rhabdoid brain tumor for 4 months old male child, who presented with unusual radiological findings, that can be confused with other brain tumors ,so we high light these unusual imaging features to aid in making correct diagnosis. Keywords: atypical teratoid–rhabdoid tumor, brain tumor, ...

The testis: the unusual, the rare and the bizarre

International Nuclear Information System (INIS)

Stewart, V.R.; Sidhu, P.S.

2007-01-01

Ultrasound is the preferred technique when imaging the scrotal contents. Although appearances of many of the more common abnormalities present the examiner with no diagnostic difficulty, the more unusual conditions may present a considerable challenge. Many normal variants, unusual and rare abnormalities may be instantly recognized once seen. The current review highlights the more unusual and rare conditions affecting the scrotal contents in order to allow the reader the opportunity to gain knowledge of their existence and to aid future interpretation of the difficult examination

48 CFR 235.070 - Indemnification against unusually hazardous risks.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Indemnification against unusually hazardous risks. 235.070 Section 235.070 Federal Acquisition Regulations System DEFENSE... DEVELOPMENT CONTRACTING 235.070 Indemnification against unusually hazardous risks. ...

Unusual computed tomography findings and complications in acute appendicitis

International Nuclear Information System (INIS)

Palacio, Glaucia Andrade e Silva; D'Ippolito, Giuseppe

2003-01-01

The objective of this article is to describe and illustrate unusual computed tomography (CT) findings in patients with acute appendicitis. We reviewed the charts of 200 patients with clinical suspicion of acute appendicitis who were submitted to abdominal CT before surgery. Patients with unusual presentation or complications were selected for illustrating the main CT findings. Unusual complications of acute appendicitis were related to anomalous position of the appendix, contiguity to intraperitoneal organs such as the liver, gall bladder, annexes and the bladder and continuous use of anti inflammatory or antibiotics during the diagnostic process. We concluded that CT is a useful diagnostic tool in patients with complicated or unusual presentation acute appendicitis. The first step towards diagnosis in these cases i to have in mind the hypothesis of appendicitis in patients with acute abdominal pain. (author)

COLD DUST BUT WARM GAS IN THE UNUSUAL ELLIPTICAL GALAXY NGC 4125

Energy Technology Data Exchange (ETDEWEB)

Wilson, C. D.; Cridland, A.; Foyle, K.; Parkin, T. J.; Cooper, E. Mentuch [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Roussel, H. [Institut d' Astrophysique de Paris, Université Pierre et Marie Curie, CNRS UMR 7095, F-75014 Paris (France); Sauvage, M.; Lebouteiller, V.; Madden, S. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot DAPNIA/Service d' Astrophysique, Bât. 709, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France); Smith, M. W. L.; Gear, W. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Baes, M.; De Looze, I. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bendo, G. [UK ALMA Regional Centre Node, Jodrell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Boquien, M.; Boselli, A.; Ciesla, L. [Aix-Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Clements, D. L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Galametz, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); and others

2013-10-20

Data from the Herschel Space Observatory have revealed an unusual elliptical galaxy, NGC 4125, which has strong and extended submillimeter emission from cold dust but only very strict upper limits to its CO and H I emission. Depending on the dust emissivity, the total dust mass is 2-5 × 10{sup 6} M {sub ☉}. While the neutral gas-to-dust mass ratio is extremely low (<12-30), including the ionized gas traced by [C II] emission raises this limit to <39-100. The dust emission follows a similar r {sup 1/4} profile to the stellar light and the dust to stellar mass ratio is toward the high end of what is found in nearby elliptical galaxies. We suggest that NGC 4125 is currently in an unusual phase where evolved stars produced in a merger-triggered burst of star formation are pumping large amounts of gas and dust into the interstellar medium. In this scenario, the low neutral gas-to-dust mass ratio is explained by the gas being heated to temperatures ≥10{sup 4} K faster than the dust is evaporated. If galaxies like NGC 4125, where the far-infrared emission does not trace neutral gas in the usual manner, are common at higher redshift, this could have significant implications for our understanding of high redshift galaxies and galaxy evolution.

Specific features of kinetics of He3-He4 solid solution transformations at superlow temperatures

International Nuclear Information System (INIS)

Mikheev, V.A.; Majdanov, V.A.; Mikhin, N.P.

1986-01-01

The NMR data on the phase transition kinetics of 3 He- 4 He solid solutions at T=100 mK are considered. Studied are solid helium samples of a molecular volume of 20.55 cm 2 /mol with a 3 He content of 0.54 %. An unusually long phase transition time is found which is dependent on the prehistory of sample. The spin diffusion of 3 He in the transformated solution concentrated phase is found to be of a quasi-one-dimensional nature with the diffusion coefficient value typical of liquid

Experimental kinetic study and modeling of calcium oxide carbonation

International Nuclear Information System (INIS)

Rouchon, L.

2012-01-01

Anthropogenic carbon dioxide (CO 2 ) emissions, major contributors to the greenhouse effect, are considered as the main cause of global warming. So, decrease of CO 2 emitted by large industrial combustion sources or power plants, is an important scientific goal. One of the approaches is based on CO 2 separation and capture from flue gas, followed by sequestration in a wide range of geological formations. In this aim, CO 2 is captured by sorbents like calcium oxide (CaO) in multi-cycle process of carbonation/de-carbonation. However, it was shown that the most important limitations of such process are related to the reversibility of reaction. CaO rapidly loses activity towards CO 2 , so the maximum extent of carbonation decreases as long as the number of cycles increases. In order to well understand the processes and parameters influencing the capture capacity of CaO-based sorbents, it appears important to get details on the kinetic law governing the reaction, which have not been really studied up to now. To investigate this reaction, CaO carbonation kinetics was followed by means of thermogravimetric analysis (TGA) on divided materials. Special care was given to the validation of the usual kinetic assumptions such as steady state and rate-determining step assumptions. The aim was to obtain a model describing the reaction in order to explain the influence of intensive variables such as carbonation temperature and CO 2 partial pressure. TGA curves obtained under isothermal and isobaric conditions showed an induction period linked to the nucleation process and a strong slowing down of the reaction rate once a given fractional conversion was reached. Both phenomena were observed to depend on carbonation temperature and CO 2 partial pressure. To explain these results, the evolution of texture and microstructure of the solid during the reaction was regarded as essential. Reaction at the grain scale induces a volume increase from CaO to CaCO 3 which causes a change in the

The kinetics of multi-compartmentalized systems, studied by radioactive tracers

International Nuclear Information System (INIS)

Gouveia, A.S. de.

1978-01-01

The use of compartmental models to investigate kinetic problems is presented. This use is restricted, however, to linear models. As an application of different methods, the kinetic behaviour of haemaccel labelled with iodine 131 is studied, the interval of the physically viable solutions being established. The existence of a class of solutions is explained as a result of lack of knowledge of a complete data set. The possibility of obtaining a single solution is also discussed. The formalism of the program SAAM (Simulation, Analysis and modelling) now judged very important for the study of multi-compartimental analysis is presented. (I.C.R) [pt

What limits production of unusual monoenoic fatty acids in transgenic plants?

Science.gov (United States)

Suh, Mi Chung; Schultz, David J; Ohlrogge, John B

2002-08-01

Unusual monounsaturated fatty acids are major constituents (greater than 80%) in seeds of Coriandrum sativum L. (coriander) and Thunbergia alata Bojer, as well as in glandular trichomes (greater than 80% derived products) of Pelargonium x hortorum (geranium). These diverged fatty acid structures are produced via distinct plastidial acyl-acyl carrier protein (ACP) desaturases. When expressed in Arabidopsis thaliana (L.) Heynh. under strong seed-specific promoters the unusual acyl-ACP desaturases resulted in accumulation of unusual monoene fatty acids at 1-15% of seed fatty acid mass. In this study, we have examined several factors that potentially limit higher production of unusual monoenes in transgenic oilseeds. (i) Immunoblots indicated that the introduced desaturases were expressed at levels equivalent to or higher than the endogenous delta9 18:0-ACP desaturase. However, the level of unusual fatty acid produced in transgenic plants was not correlated with the level of desaturase expression. (ii) The unusual desaturases were expressed in several backgrounds, including antisense 18:0-ACP desaturase plants, in fab1 mutants, and co-expressed with specialized ACP or ferredoxin isoforms. None of these experiments led to high production of expected products. (iii) No evidence was found for degradation of the unusual fatty acids during seed development. (iv) Petroselinic acid added to developing seeds was incorporated into triacylglycerol as readily as oleic acid, suggesting no major barriers to its metabolism by enzymes of glycerolipid assembly. (v) In vitro and in situ assay of acyl-ACP desaturases revealed a large discrepancy of activity when comparing unusual acyl-ACP desaturases with the endogenous delta9 18:0-ACP desaturase. The combined results, coupled with the sensitivity of acyl-ACP desaturase activity to centrifugation and low salt or detergent suggests low production of unusual monoenes in transgenic plants may be due to the lack of, or incorrect assemble of

Role of thermodynamic, kinetic and structural factors in the recrystallization behavior of amorphous erythromycin salts

Energy Technology Data Exchange (ETDEWEB)

Nanakwani, Kapil; Modi, Sameer R.; Kumar, Lokesh; Bansal, Arvind K., E-mail: akbansal@niper.ac.in

2014-04-01

Graphical abstract: - Highlights: • Crystallization kinetics of amorphous erythromycin salts was assessed. • Contribution of thermodynamic, kinetic and structural factors was evaluated. • Role of counterions on physical stability of amorphous salts was investigated. • Implications of the study: In rationalizing stabilization approach for amorphous form. - Abstract: Amorphous form has become an important drug delivery strategy for poorly water soluble drugs. However, amorphous form has inherent physical instability due to its tendency to recrystallize to stable crystalline form. In the present study, amorphous forms of erythromycin free base (ED) and its salts namely, stearate (ES), phosphate (EP) and thiocyanate (ET) were generated by in situ melt quenching and evaluated for their crystallization tendency. Salts were characterized for kinetic, thermodynamic and structural factors to understand crystallization behavior. Kinetics of crystallization followed the order as ES > EP > ET > ED. Fragility and molecular mobility does not completely explain these findings. However, configurational entropy (S{sub conf}), indicative of entropic barrier to crystallization, followed the order as ET > EP > ES > ED. Lower crystallization tendency of ED can be explained by its lower thermodynamic driving force for crystallization (H{sub conf}). This correlated well with different structural parameters for the counter ions.

Cleft lip and palate: series of unusual clinical cases.

Science.gov (United States)

Paranaíba, Lívia Máris Ribeiro; Miranda, Roseli Teixeira de; Martelli, Daniella Reis Barbosa; Bonan, Paulo Rogério Ferreti; Almeida, Hudson de; Orsi Júnior, Julian Miranda; Martelli Júnior, Hercílio

2010-01-01

Cleft lip and/or palate (CL/P) represent the most common congenital anomalies of the face, corresponding to approximately 65% of all malformations of the craniofacial region. to describe unusual clinical cases of non-syndromic CL/P (CL/PNS), diagnosed in a reference service in Minas Gerais, Brazil, and correlate these alterations with possible risk factors. we carried out a retrospective study, between the years of 1992 and the 1st half of 2009, from medical records. Among the 778 cases of CL/PNS diagnosed in the period of 17 years, 5 (0.64%) were unusual CL/PNS, and all patients were male. It was found that among the 5 patients, 2 had incomplete right cleft lip with incomplete cleft palate, 2 were affected by left incomplete cleft lip and incomplete cleft palate, and 1 had a cleft lip and palate associated with complete right cleft palate. Risk factors such as consanguinity, maternal smoking and alcohol consumption, medication usage during pregnancy, history of abortion and/or stillbirths and maternal diseases were not associated with unusual CL/PNS. This study described 5 unusual cases of CL/PNS in a Brazilian population; no associations with the risk factors analyzed were seen. It also confirmed the unusualness of the prevalence of such alterations.

Explosive sport training and torque kinetics in children.

Science.gov (United States)

Dotan, Raffy; Mitchell, Cameron J; Cohen, Rotem; Gabriel, David; Klentrou, Panagiota; Falk, Bareket

2013-07-01

A high rate of force development (RFD) is often more important than maximal force in daily and sports activities. In children, resistance training has been shown to increase maximal force. It is unclear whether, or to what extent, can children improve RFD and force kinetics. For this study, we compared strength and force kinetics of boy gymnasts with those of untrained boys and untrained men. Eight boy gymnasts (age, 9.5 ± 1.2 y), 20 untrained boys (age, 10.1 ± 1.3 y), and 20 untrained men (age, 22.9 ± 4.4 y) performed maximal, explosive, isometric elbow flexions (EF) and knee flexions (KF). Peak torque (maximal voluntary contraction (MVC)), elapsed times to 10%-100% MVC, peak rate of torque development (RTDpk), and other kinetics parameters were determined. When gymnasts were compared with untrained boys, size-normalized EF MVC was 11%-20% higher, RTDpk was 32% higher, and times to 30% and 80% MVC were 16% and 55% shorter, respectively (p kinetics parameters were similar. These findings highlight the specificity of gymnastics training, which markedly elevated the torque kinetics of young, prepubertal boys to adult levels, but only moderately affected peak torque. It is suggested that neurologic adaptations, such as enhanced firing and activation rates or increased type II motor-unit recruitment, as well as changes in musculotendinous stiffness, could explain these findings.

Kinetics of the epoxy–thiol click reaction initiated by a tertiary amine: Calorimetric study using monofunctional components

International Nuclear Information System (INIS)

Loureiro, Roi Meizoso; Amarelo, Tánia Carballeira; Abuin, Senen Paz; Soulé, Ezequiel R.; Williams, Roberto J.J.

2015-01-01

Graphical abstract: - Highlights: • Reaction kinetics of a monoepoxy and a monothiol was studied by DSC. • Benzyldimethylamine (BDMA) was used as initiator. • Reaction exhibited a long induction period followed by a fast autocatalytic rate. • A mechanistic kinetic model provided a reasonable fitting of the kinetic behavior. • The formulation simulates the behavior of room-temperature-cure commercial epoxies. - Abstract: An analysis of the kinetics of the epoxy–thiol reaction in a model stoichiometric system of monofunctional reagents, 3-mercaptopropionate (BMP) and phenylglycidylether (PGE) is reported. Benzyldimethylamine (BDMA) was employed as initiator in amounts ranging from 0.5 to 2 wt%. These formulations showed a kinetic behavior qualitatively similar to that of commercial adhesives and coatings formulated for a room-temperature cure. Isothermal DSC scans revealed the existence of a relatively long induction period preceding a fast autocatalytic reaction step. Dynamic DSC scans showed that the reaction was shifted to a lower temperature range by increasing the storage period of the initial formulation at 20 °C. This unusual kinetic behavior could be modeled assuming that thiolate anions, slowly generated during the induction period, initiated a fast autocatalytic propagation/proton transfer reaction. The kinetic model included a pseudo-steady state for the initiator concentration and an equilibrium reaction between epoxy and OH groups generated by reaction. A reasonable fitting of isothermal and dynamic DSC runs was achieved in a broad range of temperatures and amine concentrations. In particular, both the length of the induction time and the effect of the storage period were correctly predicted

Kinetics of the epoxy–thiol click reaction initiated by a tertiary amine: Calorimetric study using monofunctional components

Energy Technology Data Exchange (ETDEWEB)

Loureiro, Roi Meizoso; Amarelo, Tánia Carballeira [Gairesa, Outeiro 1, Lago (Valdoviño), 15551 A Coruña (Spain); Abuin, Senen Paz, E-mail: senen@gairesa.com [Gairesa, Outeiro 1, Lago (Valdoviño), 15551 A Coruña (Spain); Soulé, Ezequiel R. [Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), J. B. Justo 4302, 7600 Mar del Plata (Argentina); Williams, Roberto J.J., E-mail: williams@fi.mdp.edu.ar [Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), J. B. Justo 4302, 7600 Mar del Plata (Argentina)

2015-09-20

Graphical abstract: - Highlights: • Reaction kinetics of a monoepoxy and a monothiol was studied by DSC. • Benzyldimethylamine (BDMA) was used as initiator. • Reaction exhibited a long induction period followed by a fast autocatalytic rate. • A mechanistic kinetic model provided a reasonable fitting of the kinetic behavior. • The formulation simulates the behavior of room-temperature-cure commercial epoxies. - Abstract: An analysis of the kinetics of the epoxy–thiol reaction in a model stoichiometric system of monofunctional reagents, 3-mercaptopropionate (BMP) and phenylglycidylether (PGE) is reported. Benzyldimethylamine (BDMA) was employed as initiator in amounts ranging from 0.5 to 2 wt%. These formulations showed a kinetic behavior qualitatively similar to that of commercial adhesives and coatings formulated for a room-temperature cure. Isothermal DSC scans revealed the existence of a relatively long induction period preceding a fast autocatalytic reaction step. Dynamic DSC scans showed that the reaction was shifted to a lower temperature range by increasing the storage period of the initial formulation at 20 °C. This unusual kinetic behavior could be modeled assuming that thiolate anions, slowly generated during the induction period, initiated a fast autocatalytic propagation/proton transfer reaction. The kinetic model included a pseudo-steady state for the initiator concentration and an equilibrium reaction between epoxy and OH groups generated by reaction. A reasonable fitting of isothermal and dynamic DSC runs was achieved in a broad range of temperatures and amine concentrations. In particular, both the length of the induction time and the effect of the storage period were correctly predicted.

Unusual MRI findings in grey matter heteropia

International Nuclear Information System (INIS)

Soto Ares, G.; Hamon-Kerautret, M.; Leclerc, X.; Pruvo, J.P.; Houlette, C.; Godefroy, O.

1998-01-01

We report unusual MRI patterns in patients with grey matter heterotopia. Standard T1- and T2-weighted spin-echo and inversion-recovery sequences were used in 22 patients presenting with seizures or developmental delay. The images were reviewed for signal change surrounding white matter and for atypical size, morphology or topography. We found 10 cases of subependymal heterotopias 11 of focal subcortical heterotopia and of diffuse subcortical heterotopia. On clinical or MRI grounds, 8 cases were considered unusual: 2 of the subependymal type, 2 of focal subcortical heterotopia with white matter abnormalities, 2 of focal subcortical heterotopia with no clinicoradiological correlation 1 of extensive hemispheric subcortical heterotopia and 1 of diffuse subcortical heterotopia confined to the frontal lobe. The classical classification of heterotopia enables easy radiological diagnosis even in cases with unusual patterns. In some cases, heterogeneity and high signal in surrounding white matter can be found. Cortical dysplasia is the most frequent associated malformation. (orig.)

An unusual recurrence of pruritic creeping eruption after treatment

African Journals Online (AJOL)

abp

2015-08-13

Aug 13, 2015 ... However, an unusual recurrence of the disease in a Ghanaian male after standard treatment was observed ... dog or cat hookworm is not an unusual disease. However ... mistaken for fungal infections or inflammatory skin disorders. Indeed .... drug include dizziness, nausea, vomiting and intestinal cramps.

Unusual anatomy of maxillary central incisor with two roots

Directory of Open Access Journals (Sweden)

T S Ashwini Shivakumar

2012-01-01

Full Text Available Introduction: Knowledge of root canal morphology is essential for successful endodontic therapy. Failure to recognize unusual root canal anatomy may lead to unsuccessful endodontic treatment. Case Report: This case report describes the successful endodontic treatment of the maxillary central incisor with unusual anatomy of two roots and two root canals. A 23-year-old male patient was referred for dental consultation with discoloration of the maxillary right central incisor with periapical lesion, which revealed unusual anatomy of root on radiographic examination, and was confirmed upon exploration. Discussion: As described by Vertucci, the maxillary central incisor presents a single root and single root canal in 100% of the cases. However, few cases of maxillary central incisors with two canals were reported in the literature, most of which were associated with developmental anomalies like fusion, germination or dens invaginatus. Clinician should be aware of the unusual anatomical variations that should be detected by the different diagnostic resources available.

Determination of kinetics and stoichiometry of chemical sulfide oxidation in wastewater of sewer networks

DEFF Research Database (Denmark)

Nielsen, Asbjørn Haaning; Vollertsen, Jes; Hvitved-Jacobsen, Thorkild

2003-01-01

A method for determination of kinetics and stoichiometry of chemical sulfide oxidation by dissolved oxygen (DO) in wastewater is presented. The method was particularly developed to investigate chemical sulfide oxidation in wastewater of sewer networks at low DO concentrations. The method is based...... be considered constant during the course of the experiments although intermediates accumulated. This was explained by an apparent slow oxidation rate of the intermediates. The method was capable of determining kinetics and stoichiometry of chemical sulfide oxidation at DO concentrations lower than 1 g of O2 m...... on continuous measurement of the reactants allowing the kinetics to be determined at varying reactant concentrations during the course of the experiment. The kinetics determined was simulated by a rate equation. The precision of the method was assessed in terms of the standard deviation of the kinetic...

Kinetic isotope effect in dehydration of ionic solids. II. The kinetics of dehydration of calcium oxalate monohydrate

International Nuclear Information System (INIS)

Manche, E.P.; Carroll, B.

1977-01-01

The kinetics of the isothermal dehydration of the protonated and deuterated monohydrate of calcium oxalate has been investigated at 120, 150, and 170 0 C. The rate of dehydration for these salts was found to be k/sub H//k/sub D/ = 1.025 +- 0.012. This result rules out the enormous kinetic isotope effect as given in the literature. An isotope effect of a few percent is not ruled out; this magnitude is in keeping with that found by Heinzinger in other dehydration processes. An estimated difference of about 150 cal/mol between the heat of desorption for H 2 O and D 2 O should have led to a ratio, k/sub h//k/sub D/ = 1.20. The smaller observed ratio has been explained on the basis of a compensation effect and may be considered an example of the Barclay--Butler correlation

Oat cell carcinoma of the esophagus: Unusual radiological appearances

Energy Technology Data Exchange (ETDEWEB)

Bedi, D.G.; Shaw, M.T.

1986-08-01

Primary oat cell carcinoma of the esophagus is a very rare tumour. The radiographic appearance of the three cases described in this paper are unusual because they resemble benign lesions such as leiomyoma, fibrous polyp and candidiasis. It would be interesting to investigate whether such an unusual appearance is common for this neoplasm.

An unusual oral habit presenting as Dentin Hypersensitivity | Afolabi ...

African Journals Online (AJOL)

We present the case of a 30-year-old man with an unusual oral habit- office pin chewing and filing of the front tooth which resulted in dentine hypersensitivity. Clinical relevance: The role of daily oral habits and techniques of cessation were suggested in the management of dentine hypersensitivity. Keywords: Unusual oral ...

Mineralogy and petrography of HAL, an isotopically-unusual Allende inclusion

Science.gov (United States)

Allen, J. M.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1980-01-01

Results of a detailed mineralogical and textural study of the HAL (Hibonite ALlende) inclusion of the Allende meteorite, which has been found to exhibit no Mg-26 excesses despite very high Al-27/Mg-24 ratios and large fractionation effects with small nuclear effects in its Ca, are reported. The inclusion is found to consist of three up to 1-mm diameter hibonite crystals partially surrounded by a black rim resembling a devitrified glass and containing an anisotropic Al-Fe oxide, which is in turn surrounded by a 2-mm thick friable rim sequence consisting of five layers distinguishable by mineral composition. From the available evidence, it is concluded that each of the layers of the friable rim formed by the accretion of an assemblage of condensate grains rather than by the complete reaction of a HAL precursor with a nebular gas, thus explaining its unusual isotopic characteristics and supporting the conclusion that the solar nebular contained isotopically-distinct reservoirs.

Kinetics of photocatalytic removal of 2-amino-5-chloropyridine from water

Directory of Open Access Journals (Sweden)

Abramović Biljana F.

2004-01-01

Full Text Available Titanium dioxide sensitized photocatalytic degradation of a pyridine pesticide analogue, 2-amino-5-chloropyridine, was investigated by monitoring the pyridine moiety degradation, as well as by monitoring the chloride generated in the process. Effect of the initial substrate concentration on the rate of its degradation is reported. Here we show that the kinetics of both reactions are of the zero-order in the entire investigated concentration range. The Langmuir-Hinshelwood kinetic model successfully described the influence of the initial substrate concentration on the rate of the pyridine moiety degradation. It was found that dechlorination of the substrate takes place by direct photolysis. The differences in the kinetics of pyridine moiety degradation and dechlorination were explained on the basis of the electrostatic potential for the investigated compound.

Finite element modelling of the oxidation kinetics of Zircaloy-4 with a controlled metal-oxide interface and the influence of growth stress

International Nuclear Information System (INIS)

Zumpicchiat, Guillaume; Pascal, Serge; Tupin, Marc; Berdin-Méric, Clotilde

2015-01-01

Highlights: We developed two finite element models of zirconium-based alloy oxidation using the CEA Cast3M code to simulate the oxidation kinetics of Zircaloy-4: the diffuse interface model and the sharp interface model. We also studied the effect of stresses on the oxidation kinetics. The main results are: • Both models lead to parabolic oxidation kinetics in agreement with the Wagner’s theory. • The modellings enable to calculate the stress distribution in the oxide as well as in the metal. • A strong effect of the hydrostatic stress on the oxidation kinetics has been evidenced. • The stress gradient effect changes the parabolic kinetics into a sub-parabolic law closer to the experimental kinetics because of the stress gradient itself, but also because of the growth stress increase with the oxide thickness. - Abstract: Experimentally, zirconium-based alloys oxidation kinetics is sub-parabolic, by contrast with the Wagner theory which predicts a parabolic kinetics. Two finite element models have been developed to simulate this phenomenon: the diffuse interface model and the sharp interface model. Both simulate parabolic oxidation kinetics. The growth stress effects on oxygen diffusion are studied to try to explain the gap between theory and experience. Taking into account the influence of the hydrostatic stress and its gradient into the oxygen flux expression, sub-parabolic oxidation kinetics have been simulated. The sub-parabolic behaviour of the oxidation kinetics can be explained by a non-uniform compressive stress level into the oxide layer.

Kinetic instabilities in the solar wind: A short review

Energy Technology Data Exchange (ETDEWEB)

Matteini, Lorenzo, E-mail: l.matteini@imperial.ac.uk [Imperial College London, London SW7 2AZ (United Kingdom)

2016-03-25

We know from in situ measurements that solar wind plasma is far from thermal equilibrium. Distribution functions of its main constituents -electrons, protons, and alpha particles-show several departures from Maxwellian, including temperature anisotropy, relative drifts and secondary populations streaming along the local magnetic field. We present a short review of recent solar wind observations of these non-thermal features and associated signatures of wave-particle interactions. Several kinetic instabilities are expected to be at work in the solar wind during its expansion, playing a role in the continuous shaping of particle distributions with distance, and regulating the macroscopic behavior of the plasma. Over the past years, modeling of these processes by means of numerical simulations has been successful in reproducing and explaining the observations; these include the evolution of the plasma due to radial expansion and the response of individual species to different kinetic instabilities. Finally, the impact of local inhomogeneities, like current sheets and turbulence, on the development of kinetic instabilities is also discussed.

Kinetic theory of the sausage instability of a z-pinch

International Nuclear Information System (INIS)

Isichenko, M.B.; Kulyabin, K.L.; Yan'kov, V.V.

1989-01-01

A linear problem of z-pinch sausage development is considered taking into account the influence of kinetic effects for ideal scanning current. Plasma electrons are considered to be cold and ions - collisionless. It is also supposed that the magnetic field inside a pinch doesn't affect the motion of ions, which are reflected like in a mirror from a jump of an electric potential arising on the plasma boundary. In case of long-wave perturbations ka >1 the acount of kinetics leads to considerable decrease of the increment [(ka) 1/2 times] in comparison with the hydrodynamic description, that permits to explain the increased instability of z-pinches observed in experiments

Oat cell carcinoma of the esophagus: Unusual radiological appearances

International Nuclear Information System (INIS)

Bedi, D.G.; Shaw, M.T.

1986-01-01

Primary oat cell carcinoma of the esophagus is a very rare tumour. The radiographic appearance of the three cases described in this paper are unusual because they resemble benign lesions such as leiomyoma, fibrous polyp and candidiasis. It would be interesting to investigate whether such an unusual appearance is common for this neoplasm. (orig.)

Modelling reveals kinetic advantages of co-transcriptional splicing.

Directory of Open Access Journals (Sweden)

Stuart Aitken

2011-10-01

Full Text Available Messenger RNA splicing is an essential and complex process for the removal of intron sequences. Whereas the composition of the splicing machinery is mostly known, the kinetics of splicing, the catalytic activity of splicing factors and the interdependency of transcription, splicing and mRNA 3' end formation are less well understood. We propose a stochastic model of splicing kinetics that explains data obtained from high-resolution kinetic analyses of transcription, splicing and 3' end formation during induction of an intron-containing reporter gene in budding yeast. Modelling reveals co-transcriptional splicing to be the most probable and most efficient splicing pathway for the reporter transcripts, due in part to a positive feedback mechanism for co-transcriptional second step splicing. Model comparison is used to assess the alternative representations of reactions. Modelling also indicates the functional coupling of transcription and splicing, because both the rate of initiation of transcription and the probability that step one of splicing occurs co-transcriptionally are reduced, when the second step of splicing is abolished in a mutant reporter.

Modelling reveals kinetic advantages of co-transcriptional splicing.

Science.gov (United States)

Aitken, Stuart; Alexander, Ross D; Beggs, Jean D

2011-10-01

Messenger RNA splicing is an essential and complex process for the removal of intron sequences. Whereas the composition of the splicing machinery is mostly known, the kinetics of splicing, the catalytic activity of splicing factors and the interdependency of transcription, splicing and mRNA 3' end formation are less well understood. We propose a stochastic model of splicing kinetics that explains data obtained from high-resolution kinetic analyses of transcription, splicing and 3' end formation during induction of an intron-containing reporter gene in budding yeast. Modelling reveals co-transcriptional splicing to be the most probable and most efficient splicing pathway for the reporter transcripts, due in part to a positive feedback mechanism for co-transcriptional second step splicing. Model comparison is used to assess the alternative representations of reactions. Modelling also indicates the functional coupling of transcription and splicing, because both the rate of initiation of transcription and the probability that step one of splicing occurs co-transcriptionally are reduced, when the second step of splicing is abolished in a mutant reporter.

Investigation of the kinetics of the reactions of oxidation, nitration, and hydrogenation of uranium

International Nuclear Information System (INIS)

Adda, Y.

1955-06-01

Various physico-chemical methods have been used to investigate the kinetics of the oxidation hydridation and nitridation of uranium. The experimental results show that the kinetics of these reactions are influenced by many factors also the Pilling and Bedworth rule is valid only under very limited conditions. The disagreement between this rule and the experimental results could be explained by the existence of numerous mechanical faults in the compounds obtained by the dry corrosion of the metal. (author) [fr

Child–adult differences in the kinetics of torque development

Science.gov (United States)

DOTAN, RAFFY; MITCHELL, CAMERON; COHEN, ROTEM; GABRIEL, DAVID; KLENTROU, PANAGIOTA; FALK, BAREKET

2013-01-01

Children have lower size-normalised maximal voluntary force, speed, and power than adults. It has been hypothesised that these and other age-related performance differences are due to lesser type-II motor-unit utilisation in children. This should be manifested as slower force kinetics in explosive muscle contractions. The purpose of this study was to investigate the nature of child–adult force-kinetics differences and whether the latter could support that hypothesis. Untrained boys (n = 20) and men (n = 20) (10.1 ± 1.3 and 22.9 ± 4.4 years, respectively), performed maximal, explosive, isometric elbow flexions and knee extensions on a Biodex dynamometer. Peak torque (MVC), times to 10–100% MVC, and other kinetics parameters were determined. The boys’ body-mass-normalised knee extension MVC, peak rate of torque development, and %MVC at 100 ms were 26, 17 and 23% lower compared with the men and their times to 30% and 80% MVC were 24 and 48% longer, respectively. Elbow flexion kinetics showed similar or greater differences. The findings illuminate boys’ inherent disadvantage in tasks requiring speed or explosive force. It is demonstrated that the extent of the boys–men kinetics disparity cannot be explained by muscle-composition and/or musculo-tendinous-stiffness differences. We suggest therefore that the findings indirectly support children’s lower utilisation of type-II motor units. PMID:23320937

Radio-contaminated casualties treatment: an unusual application of technical shelters used on the Ile Longue site

International Nuclear Information System (INIS)

Laroche, P.; Rousset, J.; Abiliou, R.; Roe, H.; Berthelot, B.; Lemaire, L.

2002-01-01

While the radio-contaminated casualties treatment center (CTBRC) of the military hospital of Brest is reconstructed an unusual structure has been built on the Ile Longue site. Technical shelters (ETM) of the French military health service have been put together in order to constitute the CTBRC/ETM. This structure is adapted to the necessities of the nuclear site of Brest. First we explain the organization of the medical intervention in case of a nuclear accident; then we describe the functions of the CTBRC. People from hospital and medical teams of the nuclear oceanic French forces (FOST) take part in utilization, maintenance, training according to a particular protocol. (author)

Growth Kinetics and Size Distribution Dynamics of Viscous Secondary Organic Aerosol

Energy Technology Data Exchange (ETDEWEB)

Zaveri, Rahul A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Shilling, John E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Zelenyuk, Alla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Div.; Liu, Jiumeng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Bell, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Div.; Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. of Atmospheric Chemistry; D’Ambro, Emma L. [Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences and Dept. of Chemistry; Gaston, Cassandra J. [Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences; Univ. of Miami, Miami, FL (United States). Rosenstiel School of Marine and Atmospheric Science; Thornton, Joel A. [Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences and Dept. of Chemistry; Laskin, Alexander [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Purdue Univ., West Lafayette, IN (United States). Dept. of Chemistry; Lin, Peng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Purdue Univ., West Lafayette, IN (United States). Dept. of Chemistry; Wilson, Jacqueline [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Div.; Easter, Richard C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Wang, Jian [Brookhaven National Lab. (BNL), Upton, NY (United States). Environmental & Climate Sciences Dept.; Bertram, Allan K. [Univ. of British Columbia, Vancouver, BC (Canada). Dept. of Chemistry; Martin, Scot T. [Harvard Univ., Cambridge, MA (United States). School of Engineering and Applied Sciences (SEAS) and Dept. of Earth and Planetary Sciences; Seinfeld, John H. [California Inst. of Technology (CalTech), Pasadena, CA (United States). Div. of Chemistry and Chemical Engineering and Div. of Engineering and Applied Science; Worsnop, Douglas R. [Aerodyne Research, Billerica, MA (United States). Center for Aerosol and Cloud Chemistry

2017-12-15

Low bulk diffusivity inside viscous semisolid atmospheric secondary organic aerosol (SOA) can prolong equilibration time scale, but its broader impacts on aerosol growth and size distribution dynamics are poorly understood. In this article, we present quantitative insights into the effects of bulk diffusivity on the growth and evaporation kinetics of SOA formed under dry conditions from photooxidation of isoprene in the presence of a bimodal aerosol consisting of Aitken (ammonium sulfate) and accumulation (isoprene or α-pinene SOA) mode particles. Aerosol composition measurements and evaporation kinetics indicate that isoprene SOA is composed of several semivolatile organic compounds (SVOCs), with some reversibly reacting to form oligomers. Model analysis shows that liquid-like bulk diffusivities can be used to fit the observed evaporation kinetics of accumulation mode particles but fail to explain the growth kinetics of bimodal aerosol by significantly under-predicting the evolution of the Aitken mode. In contrast, the semisolid scenario successfully reproduces both evaporation and growth kinetics, with the interpretation that hindered partitioning of SVOCs into large viscous particles effectively promotes the growth of smaller particles that have shorter diffusion time scales. This effect has important implications for the growth of atmospheric ultrafine particles to climatically active sizes.

Kinetics of the reactions of hydrated electrons with metal complexes

International Nuclear Information System (INIS)

Korsse, J.

1983-01-01

The reactivity of the hydrated electron towards metal complexes is considered. Experiments are described involving metal EDTA and similar complexes. The metal ions studied are mainly Ni 2+ , Co 2+ and Cu 2+ . Rates of the reactions of the complexes with e - (aq) were measured using the pulse radiolysis technique. It is shown that the reactions of e - (aq) with the copper complexes display unusually small kinetic salt effects. The results suggest long-range electron transfer by tunneling. A tunneling model is presented and the experimental results are discussed in terms of this model. Results of approximate molecular orbital calculations of some redox potentials are given, for EDTA chelates as well as for series of hexacyano and hexaquo complexes. Finally, equilibrium constants for the formation of ternary complexes are reported. (Auth./G.J.P.)

Unusual tumour ablations: report of difficult and interesting cases

OpenAIRE

Mauri, Giovanni; Nicosia, Luca; Varano, Gianluca Maria; Shyn, Paul; Sartori, Sergio; Tombesi, Paola; Di Vece, Francesca; Orsi, Franco; Solbiati, Luigi

2017-01-01

Image-guided ablations are nowadays applied in the treatment of a wide group of diseases and in different organs and regions, and every day interventional radiologists have to face more difficult and unusual cases of tumour ablation. In the present case review, we report four difficult and unusual cases, reporting some tips and tricks for a successful image-guided treatment.

Diffusion-Weighted MR Imaging of Unusual White Matter Lesion in a Patient with Menkes Disease

International Nuclear Information System (INIS)

Lee, Eun Shin; Ryoo, Jae Wook; Choi, Dae Seob; Cho, Jae Min; Kwon, Soo Hyun; Shin, Hee Suk

2007-01-01

We report here on the diffusion-weighted imaging of unusual white matter lesions in a case of Menkes disease. On the initial MR imaging, the white matter lesions were localized in the deep periventricular white matter in the absence of diffuse cortical atrophy. The lesion showed diffuse high signal on the diffusion weighted images and diffuse progression and persistent hyperintensity on the follow up imaging. Our case suggests that the white matter lesion may precede diffuse cortical atrophy in a patient with Menkes disease. Menkes disease is an X-linked disorder that's caused by impaired intracellular transport of copper. We describe here the DWI findings of unusual and progressive white matter lesions in a case of Menkes disease. Menkes disease is an X-linked recessive disorder, and it is due to an inborn error of copper metabolism. The cause of Menkes disease has been isolated to a genetic defect in copper-transporting adenosine triphosphatase, and this results in low levels of intracellular copper. It is characterized clinically by failure to thrive, retarded mental and motor development, clonic seizure and peculiarly coarse, sparse and colorless scalp hair. These clinical findings can be explained by a dysfunction of the copper-dependent enzymes

Non-kinetic capabilities: complementing the kinetic prevalence to targeting

OpenAIRE

Ducheine, P.

2014-01-01

Targeting is used in military doctrine to describe a military operational way, using (military) means to influence a target (or addressee) in order to achieve designated political and/or military goals. The four factors italicized are used to analyse non-kinetic targeting, complementing our knowledge and understanding of the kinetic prevalence. Paradoxically, non-kinetic targeting is not recognized as a separate concept: kinetic and non-kinetic are intertwined facets of targeting. Kinetic tar...

Unusual radiological features in Paget's disease of bone

International Nuclear Information System (INIS)

Moore, T.E.; Kathol, M.H.; El-Khoury, G.Y.; Walker, C.W.; Gendall, P.W.; Whitten, C.G.

1994-01-01

The radiological diagnosis of Paget's disease of bone is usually straightforward because most cases conform to well-established classic descriptions. Diagnosis becomes more difficult, however, when radiological appearances are not typical or other disease processes mask or alter the behavior of Paget's disease. Examples are presented to illustrate four categories of unusual radiological presentation of Paget's disease; (1) unusual disease progression, (2) massive post-immobilization lysis, (3) metastatic spread to pagetic bone, and (4) vertebral end-plate destruction that mimics infection. (orig.)

Unusual causes of pneumothorax

Science.gov (United States)

Ouellette, Daniel R.; Parrish, Scott; Browning, Robert F.; Turner, J. Francis; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Madesis, Athanasios; Karaiskos, Theodoros

2014-01-01

Pneumothorax is divided to primary and secondary. It is a situation that requires immediate treatment, otherwise it could have severe health consequences. Pneumothorax can be treated either by thoracic surgeons, or pulmonary physicians. In our current work, we will focus on unusual cases of pneumothorax. We will provide the etiology and treatment for each case, also a discussion will be made for each situation. PMID:25337394

Kinetics of sintering of uranium dioxide

International Nuclear Information System (INIS)

Soni, N.C.; Moorthy, V.K.

1978-01-01

The kinetics of sintering of UO 2 powders derived from ADU route and calcined at different temperatures was studied. The activation energy for sintering was found to depend on the calcination temperature, the density chosen and the sintering temperature range. The motive force for sintering is the excess free energy in the particle system. This exists in the powder compact in the form of surface energy and the excess lattice energy due to defects. The defects which can be eliminated at the operating temperature are responsible for the mobility and hence sintering. This concept of the motive force for sintering has been used to explain the difference in the activation energies observed in the present study. This would also explain phenomena such as attainment of limiting density, presence of optimum sintering temperature and the influence of calcination treatments on the sintering behaviour of powders. (author)

Unusual imaging characteristics of complicated hydatid disease

International Nuclear Information System (INIS)

Turgut, Ahmet Tuncay; Altin, Levent; Topcu, Salih; Kilicoglu, Buelent; Altinok, Tamer; Kaptanoglu, Erkan; Karademir, Alp; Kosar, Ugur

2007-01-01

Hydatid disease, a worldwide zoonosis, is caused by the larval stage of the Echinococcus tapeworm. Although the liver and the lungs are the most frequently involved organs in the body, hydatid cysts of other organs are unusual. Radiologically, they usually demonstrate typical imaging findings, but unusual imaging characteristics of complicated cyst of hydatid disease, associated with high morbidity and mortality, are rarely described in the literature. The purpose of this study is to review the general features of hydatidosis and to discuss atypical imaging characteristics of the complicated hydatid disease in the human, with an emphasis on structure and rupture of the cystic lesion as well as ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) features of the disease. In our study, the available literature and images of the cases with complicated hydatidosis involving liver, lung, brain, spine and orbit were reviewed retrospectively. In hydatid disease, there are many potential local and systemic complications due to secondary involvement in almost any anatomic location in humans. Radiologically, in addition to the presence of atypical findings such as perifocal edema, non-homogenous contrast enhancement, multiplicity or septations and calcification, various unusual manifestations due to rupture or infection of the cyst have been observed in our cases with complicated hydatid disease. To prevent subsequent acute catastrophic results and the development of recurrences in various organs, it should be kept in mind that complicated hydatid cysts can cause unusual USG, CT, and MRI findings, in addition to typical ones, in endemic areas. Therefore, familiarity with atypical radiological appearances of complicated hydatid disease may be valuable in making a correct diagnosis and treatment

Unusual imaging characteristics of complicated hydatid disease

Energy Technology Data Exchange (ETDEWEB)

Turgut, Ahmet Tuncay [Department of Radiology, Ankara Training and Research Hospital, Ankara (Turkey)]. E-mail: ahmettuncayturgut@yahoo.com; Altin, Levent [Department of Radiology, Numune Training and Research Hospital, Ankara (Turkey); Topcu, Salih [Department of Thoracic Surgery, Faculty of Medicine, Kocaeli University, Izmit (Turkey); Kilicoglu, Buelent [Department of 4th General Surgery, Ankara Training and Research Hospital, Ankara (Turkey); Altinok, Tamer [Department of Thoracic Surgery, Meram Faculty of Medicine, Selcuk University, Konya (Turkey); Kaptanoglu, Erkan [Department of Neurosurgery, Numune Training and Research Hospital, Ankara (Turkey); Karademir, Alp [Department of Radiology, Numune Training and Research Hospital, Ankara (Turkey); Kosar, Ugur [Department of Radiology, Ankara Training and Research Hospital, Ankara (Turkey)

2007-07-15

Hydatid disease, a worldwide zoonosis, is caused by the larval stage of the Echinococcus tapeworm. Although the liver and the lungs are the most frequently involved organs in the body, hydatid cysts of other organs are unusual. Radiologically, they usually demonstrate typical imaging findings, but unusual imaging characteristics of complicated cyst of hydatid disease, associated with high morbidity and mortality, are rarely described in the literature. The purpose of this study is to review the general features of hydatidosis and to discuss atypical imaging characteristics of the complicated hydatid disease in the human, with an emphasis on structure and rupture of the cystic lesion as well as ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) features of the disease. In our study, the available literature and images of the cases with complicated hydatidosis involving liver, lung, brain, spine and orbit were reviewed retrospectively. In hydatid disease, there are many potential local and systemic complications due to secondary involvement in almost any anatomic location in humans. Radiologically, in addition to the presence of atypical findings such as perifocal edema, non-homogenous contrast enhancement, multiplicity or septations and calcification, various unusual manifestations due to rupture or infection of the cyst have been observed in our cases with complicated hydatid disease. To prevent subsequent acute catastrophic results and the development of recurrences in various organs, it should be kept in mind that complicated hydatid cysts can cause unusual USG, CT, and MRI findings, in addition to typical ones, in endemic areas. Therefore, familiarity with atypical radiological appearances of complicated hydatid disease may be valuable in making a correct diagnosis and treatment.

Kinetically controlled thermal response of beta2-microglobulin amyloid fibrils.

Science.gov (United States)

Sasahara, Kenji; Naiki, Hironobu; Goto, Yuji

2005-09-23

Calorimetric measurements were carried out using a differential scanning calorimeter in the temperature range from 10 to 120 degrees C for characterizing the thermal response of beta2-microglobulin amyloid fibrils. The thermograms of amyloid fibril solution showed a remarkably large decrease in heat capacity that was essentially released upon the thermal unfolding of the fibrils, in which the magnitude of negative heat capacity change was not explicable in terms of the current accessible surface area model of protein structural thermodynamics. The heat capacity-temperature curve of amyloid fibrils prior to the fibril unfolding exhibited an unusual dependence on the fibril concentration and the heating rate. Particularly, the heat needed to induce the thermal response was found to be linearly dependent on the heating rate, indicating that its thermal response is under a kinetic control and precluding the interpretation in terms of equilibrium thermodynamics. Furthermore, amyloid fibrils of amyloid beta peptides also exhibited a heating rate-dependent exothermic process before the fibril unfolding, indicating that the kinetically controlled thermal response may be a common phenomenon to amyloid fibrils. We suggest that the heating rate-dependent negative change in heat capacity is coupled to the association of amyloid fibrils with characteristic hydration pattern.

A Critical Review of Models of the H-2/H2O/Ni/SZ Electrode Kinetics

DEFF Research Database (Denmark)

Mogensen, Mogens Bjerg; Høgh, Jens Valdemar Thorvald; Hansen, Karin Vels

2007-01-01

Various models of the H-2/H2O/Ni/SZ (SZ = stabilized zirconia) electrode kinetics have been presented in the literature in order to explain the reported experimental data. However, there has been a strong tendency of using a limited set of data to "verify" a given model, disregarding other data...... sets, which do not fit the model. We have inspected some models in the literature, and problems (e.g. no quantitative model has explained the large variation in reported values of apparent activation energy of the electrode kinetics) as well as strengths of the models are discussed. We point out...... important for any realistic and useful mathematical model of the H-2/H2O/Ni/SZ electrode....

Kinetic models of controllable pore growth of anodic aluminum oxide membrane

Science.gov (United States)

Huang, Yan; Zeng, Hong-yan; Zhao, Ce; Qu, Ye-qing; Zhang, Pin

2012-06-01

An anodized Al2O3 (AAO) membrane with apertures about 72 nm in diameter was prepared by two-step anodic oxidation. The appearance and pore arrangement of the AAO membrane were characterized by energy dispersive x-ray spectroscopy and scanning electron microscopy. It was confirmed that the pores with high pore aspect ratio were parallel, well-ordered, and uniform. The kinetics of pores growth in the AAO membrane was derived, and the kinetic models showed that pores stopped developing when the pressure ( σ) trended to equal the surface tension at the end of anodic oxidation. During pore expansion, the effects of the oxalic acid concentration and expansion time on the pore size were investigated, and the kinetic behaviors were explained with two kinetic models derived in this study. They showed that the pore size increased with extended time ( r= G· t+ G'), but decreased with increased concentration ( r = - K·ln c- K') through the derived mathematic formula. Also, the values of G, G', K, and K' were derived from our experimental data.

Pseudoliquid behavior of heteropoly compound catalysts. Unusual pressure dependencies of the rate and selectivity for ethanol dehydration

International Nuclear Information System (INIS)

Misono, M.; Okuhara, T.; Ichiki, T.; Arai, T.; Kanda, Y.

1987-01-01

Heteropoly compounds arenow utilized as industrial catalysts for olefin hydration and aldehyde oxidation and as interesting cluster models of mixed oxide catalysts. Certain heteropoly acids, like H 3 PW 12 O 40 and H 3 PMo 12 O 40 , easily absorb a large amount of water, alchols, and ethers in the solid state, although their surface areas are very low. This is not adsorption in micropores; rather molecules are absorbed between the lattice polyanions, sometimes expanding the lattice. The expansion can be seen visually as well as by x-ray diffraction. The authors showed that in some cases catalytic reactions take place in this novel bulk phase. Presumably due to this behavior, very high catalytic activity and unique selectivity as well as unusual reactivity order have been observed. They called this state the pseudoliquid phase. However, in only one case was the amount of absorbed reactant measured under the working conditions. They report here unusual pressure dependencies of the rate and selectivity of ethanol dehydration over heteropoly compounds. The dependency can only be explained by the formation of a pseudoliquid phase, i.e., a phase where the amount of absorbed ethanol has changed as a function of ethanol pressure

Unusual causes of obstructive jaundice. Computed tomography

International Nuclear Information System (INIS)

Rodriguez, E.; Pombo, F.; Cao, I.; Fernandez, R.; Riba da, M.

1998-01-01

The purpose of this study is to present selected computed tomography (CT) images showing unusual causes of obstructive jaundice. We reviewed retrospectively the Ct findings of obstructive jaundice in 227 patients. The most common causes of biliary obstruction were adenocarcinoma of the pancreatic head (n=77) and cholangiocarcinoma (n=65). In 13 cases (5.7%), the etiology of obstructive jaundice was unusual or exceptional: tuberculous adenitis (n=3), obstruction of afferent loop (n=2)signet ring cell adenocarcinoma (n=3); in duodenum, gallbladder and papilla of Water), Mirizzi syndrome (n=1), adenocarcinoma of the hepatic flexure (n=1), choledochal cyst (n=1) and pancreatic lymphoma (n=1). (Author) 13 refs

Kinetic mix mechanisms in shock-driven inertial confinement fusion implosions

Energy Technology Data Exchange (ETDEWEB)

Rinderknecht, H. G.; Sio, H.; Li, C. K.; Zylstra, A. B.; Rosenberg, M. J.; Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Hoffman, N.; Kagan, G.; Molvig, K. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Betti, R.; Yu Glebov, V.; Meyerhofer, D. D.; Sangster, T. C.; Seka, W.; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Bellei, C.; Amendt, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2014-05-15

Shock-driven implosions of thin-shell capsules, or “exploding pushers,” generate low-density, high-temperature plasmas in which hydrodynamic instability growth is negligible and kinetic effects can play an important role. Data from implosions of thin deuterated-plastic shells with hydroequivalent D{sup 3}He gas fills ranging from pure deuterium to pure {sup 3}He [H. G. Rinderknecht et al., Phys. Rev. Lett. 112, 135001 (2014)] were obtained to evaluate non-hydrodynamic fuel-shell mix mechanisms. Simulations of the experiments including reduced ion kinetic models support ion diffusion as an explanation for these data. Several additional kinetic mechanisms are investigated and compared to the data to determine which are important in the experiments. Shock acceleration of shell deuterons is estimated to introduce mix less than or comparable to the amount required to explain the data. Beam-target mechanisms are found to produce yields at most an order of magnitude less than the observations.

Acid-catalyzed kinetics of indium tin oxide etching

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae-Hyeok; Kim, Seong-Oh; Hilton, Diana L. [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Centre for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang Drive, 637553 (Singapore); Cho, Nam-Joon, E-mail: njcho@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Centre for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang Drive, 637553 (Singapore); School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore)

2014-08-28

We report the kinetic characterization of indium tin oxide (ITO) film etching by chemical treatment in acidic and basic electrolytes. It was observed that film etching increased under more acidic conditions, whereas basic conditions led to minimal etching on the time scale of the experiments. Quartz crystal microbalance was employed in order to track the reaction kinetics as a function of the concentration of hydrochloric acid and accordingly solution pH. Contact angle measurements and atomic force microscopy experiments determined that acid treatment increases surface hydrophilicity and porosity. X-ray photoelectron spectroscopy experiments identified that film etching is primarily caused by dissolution of indium species. A kinetic model was developed to explain the acid-catalyzed dissolution of ITO surfaces, and showed a logarithmic relationship between the rate of dissolution and the concentration of undisassociated hydrochloric acid molecules. Taken together, the findings presented in this work verify the acid-catalyzed kinetics of ITO film dissolution by chemical treatment, and support that the corresponding chemical reactions should be accounted for in ITO film processing applications. - Highlights: • Acidic conditions promoted indium tin oxide (ITO) film etching via dissolution. • Logarithm of the dissolution rate depended linearly on the solution pH. • Acid treatment increased ITO surface hydrophilicity and porosity. • ITO film etching led to preferential dissolution of indium species over tin species.

Analyzing Students’ Level of Understanding on Kinetic Theory of Gases

Science.gov (United States)

Nurhuda, T.; Rusdiana, D.; Setiawan, W.

2017-02-01

The purpose of this research is to analysis students’ level of understanding on gas kinetic theory. The method used is descriptive analytic with 32 students at the 11th grade of one high school in Bandung city as a sample. The sample was taken using random sampling technique. Data collection tool used is an essay test with 23 questions. The instrument was used to identify students’ level of understanding and was judged by four expert judges before it was employed, from 27 questions become to 23 questions, for data collection. Questions used are the conceptual understanding including the competence to explain, extrapolate, translate and interpret. Kinetic theory of gases section that was tested includes ideal gas law, kinetic molecular theory and equipartition of energy. The result shows from 0-4 level of understanding, 19% of the students have partial understanding on the 3th level and 81% of them have partial understanding with a specific misconception on 2th level. For the future research, it is suggested to overcome these conceptual understanding with an Interactive Lecture Demonstrations teaching model and coupled with some teaching materials based on multi-visualization because kinetic theory of gases is a microscopic concept.

Unusual ZFC and FC magnetic behavior in thin Co multi-layered structure

Energy Technology Data Exchange (ETDEWEB)

Ben-Dor, Oren; Yochelis, Shira [Department of Applied Physics, Center of Nanoscience and Nanotechnology, Hebrew University, Jerusalem 91904 (Israel); Felner, Israel [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Paltiel, Yossi [Department of Applied Physics, Center of Nanoscience and Nanotechnology, Hebrew University, Jerusalem 91904 (Israel)

2017-04-15

The observation of unusual magnetic phenomena in a Ni -based magnetic memory device ( O. Ben-Dor et al., 2013) encouraged us to conduct a systematic research on Co based multi-layered structure which contains a α-helix L polyalanine (AHPA-L) organic compound. The constant Co thickness is 7 nm and AHPA-L was also replaced by non-chiral 1-Decanethiol organic molecules. Both organic compounds were chemisorbed on gold by a thiol group. The dc magnetic field (H) was applied parallel and perpendicular to the surface layers. The perpendicular direction is the easy magnetization axis and along this orientation only, the zero-field-cooled (ZFC) plots exhibit a pronounced peak around 55–58 K. This peak is suppressed in the second ZFC and field-cooled (FC) runs performed shortly after the virgin ZFC one. Thus, around the peak position ZFC>FC a phenomenon seldom observed. This peak reappears after measuring the same material six months later. This behavior appears in layers with the non-chiral 1-Decanethiol and it is very similar to that obtained in sulfur doped amorphous carbon. The peak origin and the peculiar ZFC>FC case are qualitatively explained. - Highlights: • FC curve crosses ZFC curve in a 7 nm Co and thiol-based organic molecules multi-layered structure. • The ZFC>FC phenomena occurs for H perpendicular along the easy axis. • This phenomenon disappears in the second FC-ZFC run performed shortly after. • The unusual behavior reappears after six months.

Interpretation of unusual events from CERN and DESY

International Nuclear Information System (INIS)

Hall, L.J.; Jaffee, R.L.; Rosner, J.L.

1984-01-01

Several classes of interesting and unusual events from the Sp-barpS and from PETRA are studied with two purposes in mind. Firstly, varieties of background within the standard SU(3)xSU(2)xU(1) model are described, together with estimates of the number of expected events. Secondly, a review of the recent explanations of the events involving new physics is given. Critical assessments of these proposals focus on the assumptions made, expected rates for the unusual events, and the ability to account for events of several categories

Recurring waterbird mortalities and unusual etiologies

Science.gov (United States)

Cole, Rebecca A.; Franson, J. Christian; Boere, Gerard C.; Galbraith, Colin A.; Stroud, David A.

2006-01-01

Over the last decade, the National Wildlife Health Center of the United States Geological Survey has documented various largescale mortalities of birds caused by infectious and non-infectious disease agents. Some of these mortality events have unusual or unidentified etiologies and have been recurring. While some of the causes of mortalities have been elucidated, others remain in various stages of investigation and identification. Two examples are discussed: 1) Leyogonimus polyoon (Class: Trematoda), not found in the New World until 1999, causes severe enteritis and has killed over 15 000 American Coot Fulica americana in the upper mid-western United States. The geographic range of this parasite within North America is predicted to be limited to the Great Lakes Basin. 2) In the early 1990s, estimates of up to 6% of the North American population of the Eared Grebe Podiceps nigricollis died at Salton Sea, California, with smaller mortalities occurring throughout the 1990s. Birds were observed to have unusual preening behaviour, and to congregate at freshwater drains and move onto land. Suggested etiologies included interactions of contaminants, immuno-suppression, an unusual form of a bacterial disease, and an unknown biotoxin. During studies carried out from 2000 to 2003, Eared Grebe mortality did not approach the level seen in the early 1990s and, although bacteria were identified as minor factors, the principal cause of mortality remains undetermined. The potential population impact of these emerging and novel disease agents is currently unknown.

On the biophysics and kinetics of toehold-mediated DNA strand displacement.

Science.gov (United States)

Srinivas, Niranjan; Ouldridge, Thomas E; Sulc, Petr; Schaeffer, Joseph M; Yurke, Bernard; Louis, Ard A; Doye, Jonathan P K; Winfree, Erik

2013-12-01

Dynamic DNA nanotechnology often uses toehold-mediated strand displacement for controlling reaction kinetics. Although the dependence of strand displacement kinetics on toehold length has been experimentally characterized and phenomenologically modeled, detailed biophysical understanding has remained elusive. Here, we study strand displacement at multiple levels of detail, using an intuitive model of a random walk on a 1D energy landscape, a secondary structure kinetics model with single base-pair steps and a coarse-grained molecular model that incorporates 3D geometric and steric effects. Further, we experimentally investigate the thermodynamics of three-way branch migration. Two factors explain the dependence of strand displacement kinetics on toehold length: (i) the physical process by which a single step of branch migration occurs is significantly slower than the fraying of a single base pair and (ii) initiating branch migration incurs a thermodynamic penalty, not captured by state-of-the-art nearest neighbor models of DNA, due to the additional overhang it engenders at the junction. Our findings are consistent with previously measured or inferred rates for hybridization, fraying and branch migration, and they provide a biophysical explanation of strand displacement kinetics. Our work paves the way for accurate modeling of strand displacement cascades, which would facilitate the simulation and construction of more complex molecular systems.

Isotopic evidence for the formation of unusually humus-rich soils in the Baltic region

Science.gov (United States)

Leinweber, Peter; Acksel, Andre; Kühn, Peter

2017-04-01

Arable mineral soils in the Pleistocene landscape of Northern Germany usually contain about 4 to 8 kg of organic C (Corg) per m2, most of which is visually recognizable concentrated in the tilled topsoil horizon. Some unusually humus-rich (10 to 20 kg Corg m-2), and deeply (> 70 cm) dark-colored soils in coastal regions with mollic properties have been classified as Chernozems. Their location far away from the middle German and Central European Chernozem regions, absence of steppe vegetation and semi-arid climate conditions make classical pedogenetic theories doubtful. However, non-targeted mass spectrometric analyses of soil organic matter (SOM) composition revealed great similarities with typical Chernozems worldwide (Thiele-Bruhn et al., 2014) and made alternative (e.g. waterlogged) pathways of SOM accumulation unlikely. Subsequent detailed multi-method SOM analyses down the soil profiles revealed relative enrichments in cyclic ("black carbon") and heterocyclic organic compounds in the deeper, bioturbated horizons. These were plausibly explained by the input of combustion residues, likely originating from anthropogenic activities because spots of these soils coincided with archeological artifacts of early settlements (Acksel et al., 2016). However, these finding could not completely explain the genesis of Chernozems in the Baltic region. Therefore, we actually explored isotope analyses (12/13C, 13/14C, 14/15N, 32/34S) to find out the origin of these unusual SOM enrichments and the time period in which it occurred. The results will be compiled to a consistent hypothesis on the formation of these soils in the Baltic and other Northern European regions. References Acksel, A., W. Amelung, P. Kühn, E. Gehrt, T. Regier, P. Leinweber. 2016. Soil organic matter characteristics as indicator of Chernozem genesis in the Baltic Sea region. Geoderma Regional 7, 187-200. Thiele-Bruhn, S., Leinweber P., Eckhardt K.-U., Siem H.K., Blume H.-P. 2014. Identifying Chernozem

Unusual anatomy of maxillary central incisor with two roots

OpenAIRE

T S Ashwini Shivakumar; Saleem Makandar; Ajay Kadam

2012-01-01

Introduction: Knowledge of root canal morphology is essential for successful endodontic therapy. Failure to recognize unusual root canal anatomy may lead to unsuccessful endodontic treatment. Case Report: This case report describes the successful endodontic treatment of the maxillary central incisor with unusual anatomy of two roots and two root canals. A 23-year-old male patient was referred for dental consultation with discoloration of the maxillary right central incisor with periapical les...

Rapid kinetics of dehalogenation promoted by iodotyrosine deiodinase from human thyroid.

Science.gov (United States)

Bobyk, Kostyantyn D; Ballou, David P; Rokita, Steven E

2015-07-28

Reductive dehalogenation such as that catalyzed by iodotyrosine deiodinase (IYD) is highly unusual in aerobic organisms but necessary for iodide salvage from iodotyrosine generated during thyroxine biosynthesis. Equally unusual is the dependence of this process on flavin. Rapid kinetics have now been used to define the basic processes involved in IYD catalysis. Time-dependent quenching of flavin fluorescence was used to monitor halotyrosine association to IYD. The substrates chloro-, bromo-, and iodotyrosine bound with similar rate constants (kon) ranging from 1.3 × 10(6) to 1.9 × 10(6) M(-1) s(-1). Only the inert substrate analogue fluorotyrosine exhibited a significantly (5-fold) slower kon (0.3 × 10(6) M(-1) s(-1)). All data fit a standard two-state model and indicated that no intermediate complex accumulated during closure of the active site lid induced by substrate. Subsequent halide elimination does not appear to limit reactions of bromo- and iodotyrosine since both fully oxidized the reduced enzyme with nearly equivalent second-order rate constants (7.3 × 10(3) and 8.6 × 10(3) M(-1) s(-1), respectively) despite the differing strength of their carbon-halogen bonds. In contrast to these substrates, chlorotyrosine reacted with the reduced enzyme approximately 20-fold more slowly and revealed a spectral intermediate that formed at approximately the same rate as the bromo- and iodotyrosine reactions.

Specific features of kinetics of He/sup 3/-He/sup 4/ solid solution transformations at superlow temperatures

Energy Technology Data Exchange (ETDEWEB)

Mikheev, V A; Majdanov, V A; Mikhin, N P

1986-06-01

The NMR data on the phase transition kinetics of /sup 3/He-/sup 4/He solid solutions at T=100 mK are considered. Studied are solid helium samples of a molecular volume of 20.55 cm/sup 2//mol with a /sup 3/He content of 0.54%. An unusually long phase transition time is found which is dependent on the prehistory of sample. The spin diffusion of /sup 3/He in the transformated solution concentrated phase is found to be of a quasi-one-dimensional nature with the diffusion coefficient value typical of liquid.

Xanthogranulomatous endometritis: an unusual pathological entity ...

African Journals Online (AJOL)

Xanthogranulomatous endometritis is an unusual pathological entity mimicking endometrial carcinoma. This shows sheets of foamy histiocytes alongwith other inflammatory cells. We, hereby, report a case of 45 year multigravida female with irregular menstrual history, clinically diagnosed as carcinoma and ...

Unusual near-band-edge photoluminescence at room temperature in heavily-doped ZnO:Al thin films prepared by pulsed laser deposition

International Nuclear Information System (INIS)

Mohanty, Bhaskar Chandra; Yeon, Deuk Ho; Das, Sachindra Nath; Kwak, Ji Hye; Yoon, Kyung Hoon; Cho, Yong Soo

2013-01-01

Room temperature photoluminescence (PL) properties of heavily-doped ZnO:Al thin films (with carrier concentration n in the range of 5–20 × 10 20 cm −3 ) prepared by pulsed laser deposition have been investigated. Despite their high carrier concentration, the films exhibited strong room temperature near-band-edge bound excitons at ∼3.34 eV and an unusual peak at ∼3.16 eV, and negligible deep-level emission even for the films deposited at a temperature as low as 25 °C. The radiative efficiency of the films increased with growth temperature as a result of increased n and improved crystallinity. A large blue shift of optical band gap was observed, which is consistent with the n-dependent Burstein–Moss and band gap-renormalization effects. Comparison of the results of the PL and optical measurements revealed a large Stokes shift that increased with increase in n. It has been explained by a model based on local potential fluctuations caused by randomly-distributed doping impurities. - Highlights: • Studied PL properties of heavily-doped ZnO:Al films grown by PLD. • Unusual strong near-band-edge emissions and negligible deep-level emission at RT. • Increased optical band gap with growth temperature and thus carrier concentration. • Stokes shift and PL peak width increased with carrier concentration. • Results explained by a model based on local potential fluctuations

An unusual coexistence of Addison's disease and ...

African Journals Online (AJOL)

2013-07-17

Jul 17, 2013 ... Case Study: An unusual coexistence of Addison's disease and phaeochromocytoma. 164 ... strongly positive. ... Department of Endocrinology and Metabolism, Ondokuz Mayis University Medical School, Samsun, Turkey.

Application of first order rate kinetics to explain changes in bloom toxicity—the importance of understanding cell toxin quotas

Science.gov (United States)

Orr, Philip T.; Willis, Anusuya; Burford, Michele A.

2018-04-01

Cyanobacteria are oxygenic photosynthetic Gram-negative bacteria that can form potentially toxic blooms in eutrophic and slow flowing aquatic ecosystems. Bloom toxicity varies spatially and temporally, but understanding the mechanisms that drive these changes remains largely a mystery. Changes in bloom toxicity may result from changes in intracellular toxin pool sizes of cyanotoxins with differing molecular toxicities, and/or from changes in the cell concentrations of toxic and non-toxic cyanobacterial species or strains within bloom populations. We show here how first-order rate kinetics at the cellular level can be used to explain how environmental conditions drive changes in bloom toxicity at the ecological level. First order rate constants can be calculated for changes in cell concentration (μ c: specific cell division rate) or the volumetric biomass concentration (μ g: specific growth rate) between short time intervals throughout the cell cycle. Similar first order rate constants can be calculated for changes in nett volumetric cyanotoxin concentration (μ tox: specific cyanotoxin production rate) over similar time intervals. How μ c (or μ g ) covaries with μ tox over the cell cycle shows conclusively when cyanotoxins are being produced and metabolised, and how the toxicity of cells change in response to environment stressors. When μ tox/μ c>1, cyanotoxin cell quotas increase and individual cells become more toxic because the nett cyanotoxin production rate is higher than the cell division rate. When μ tox/μ c=1, cell cyanotoxin quotas remains fixed because the nett cyanotoxin production rate matches the cell division rate. When μ tox/μ ccyanotoxin cell quota decreases because either the nett cyanotoxin production rate is lower than the cell division rate, or metabolic breakdown and/or secretion of cyanotoxins is occurring. These fundamental equations describe cyanotoxin metabolism dynamics at the cellular level and provide the necessary

The rarity of "unusual" [corrected] dispositions of victim bodies: staging and posing.

Science.gov (United States)

Keppel, Robert D; Weis, Joseph G

2004-11-01

The act of leaving a victim's body in an unusual position is a conscious criminal action by an offender to thwart an investigation, shock the finder and investigators of the crime scene, or give perverted pleasure to the killer. The unusual position concepts of posing and staging a murder victim have been documented thoroughly and have been accepted by the courts as a definable phenomenon. One staging case and one posing case are outlined and reveal characteristics of those homicides. From the Washington State Attorney General's Homicide Investigation and Tracking System's database on murder covering the years 1981-2000 (a total of 5,224 cases), the relative frequency of unusual body dispositions is revealed as a very rare occurrence. Only 1.3% of victims are left in an unusual position, with 0.3% being posed and 0.1% being staged. The characteristics of these types of murders also set them apart: compared to all other murders, in staged murders the victims and killers are, on average, older. All victims and offenders in the staged murders are white, with victims being disproportionately white in murders with any kind of unusual body disposition. Likewise, females stand out as victims when the body is posed, staged, or left in other unusual positions. Whereas posed bodies are more likely to include sexual assault, often in serial murders, there is no evidence of either in the staged cases. Lastly, when a body is left in an unusual position, binding is more likely, as well as the use of more "hands on" means of killing the victim, such as stabbing or cutting weapons, bludgeons, ligatures, or hands and feet.

Attitudes of Tourists about the Possibility of Development of Unusual Hotels in Serbia

Directory of Open Access Journals (Sweden)

Klisara Dubravka

2015-01-01

Full Text Available This paper deals with the problem of relatively young type of hotel that is increasingly attracting the attention of the modern tourist. Unusual hotels are very interesting phenomenon, not only for tourists and hospitality professionals, but also for people who are (currently out of the tourist flows. These are facilities with untypical architectural design, non-standard equipped or with services that are not common in the hospitality industry. They often contribute to the attractiveness of the area in which they are located. However, business sustainability of unusual hotels, as well as any other hotel, depends on guests, i.e. number of overnight stays.We present the results of research conducted among tourists in Serbia. The main task is to examined whether tourists are interested in the potential developing of unusual hotels. If so, which subtypes of unusual hotel would be best suited for the territory of Serbia. In order to compare experiences and operating results, parallel survey was conducted among owners of unusual hotels around the world. The results suggest a conclusion - with a favourable investment climate, unusual hotels should have a future in Serbia.

Mechanistic and kinetic insights into the thermally induced rearrangement of alpha-pinene.

Science.gov (United States)

Stolle, Achim; Ondruschka, Bernd; Findeisen, Matthias

2008-11-07

The thermal rearrangement of alpha-pinene (1) is interesting from mechanistic as well as kinetic point of view. Carrier gas pyrolyses with 1 and its acyclic isomers ocimene (2) and alloocimene (3) were performed to investigate the thermal network of these hydrocarbons. Kinetic analysis of the major reaction steps allows for a deeper insight in the reaction mechanism. Thus it was possible to explain the racemization of 1, the formation of racemic limonene (4), and the absence of the primary pyrolysis product 2 in the reaction mixture resulting from thermal rearrangement of 1. Results supported the conclusion that the reactions starting with 1 involve biradical transition states.

A kinetic-MHD model for low frequency phenomena

International Nuclear Information System (INIS)

Cheng, C.Z.

1991-07-01

A hybrid kinetic-MHD model for describing low-frequency phenomena in high beta anisotropic plasmas that consist of two components: a low energy core component and an energetic component with low density. The kinetic-MHD model treats the low energy core component by magnetohydrodynamic (MHD) description, the energetic component by kinetic approach such as the gyrokinetic equation, and the coupling between the dynamics of these two components through plasma pressure in the momentum equation. The kinetic-MHD model optimizes both the physics contents and the theoretical efforts in studying low frequency MHD waves and transport phenomena in general magnetic field geometries, and can be easily modified to include the core plasma kinetic effects if necessary. It is applicable to any magnetized collisionless plasma system where the parallel electric field effects are negligibly small. In the linearized limit two coupled eigenmode equations for describing the coupling between the transverse Alfven type and the compressional Alfven type waves are derived. The eigenmode equations are identical to those derived from the full gyrokinetic equation in the low frequency limit and were previously analyzed both analytically nd numerically to obtain the eigenmode structure of the drift mirror instability which explains successfully the multi-satellite observation of antisymmetric field-aligned structure of the compressional magnetic field of Pc 5 waves in the magnetospheric ring current plasma. Finally, a quadratic form is derived to demonstrate the stability of the low-frequency transverse and compressional Alfven type instabilities in terms of the pressure anisotropy parameter τ and the magnetic field curvature-pressure gradient parameter. A procedure for determining the stability of a marginally stable MHD wave due to wave-particle resonances is also presented

An unusual foreign body of esophagus

Directory of Open Access Journals (Sweden)

Surinder K Singhal

2010-07-01

Full Text Available We report a rare case of an unusually long foreign body (Datun impacted in the esophagus of a 56 year-old gentleman. He was literate, without any psychiatric illness and had been using “Neem” (Azadirachta indica stick for cleaning his teeth for the past twenty years. Neem sticks are used for brushing teeth, perhaps one of the earliest and very effective dental care. On closer questioning he revealed his habit of passing the Neem stick into his throat with the aim of cleaning it too while cleaning his teeth. He presented to our emergency early in the morning with this strange long foreign body impacted in his esophagus which was removed successfully using a Jackson’s adult rigid oesophagoscope. We believe this to be the first case of such an unusually long foreign body to be reported in the literature.

Stabilization of actinides and lanthanides in unusually high oxidation states

International Nuclear Information System (INIS)

Eller, P.G.; Penneman, R.A.

1986-01-01

Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO 3 or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF 5 /HF solution or Pu(VII) in Li 5 PuO 6 ). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs

Probable Unusual Transmission of Zika Virus

Centers for Disease Control (CDC) Podcasts

This podcast discusses a study about the probable unusual transmission of Zika Virus Infection from a scientist to his wife, published in the May 2011 issue of Emerging Infectious Diseases. Dr. Brian Foy, Associate Professor at Colorado State University, shares details of this event.

Joint kinetic determinants of starting block performance in athletic sprinting.

Science.gov (United States)

Brazil, Adam; Exell, Timothy; Wilson, Cassie; Willwacher, Steffen; Bezodis, Ian N; Irwin, Gareth

2018-07-01

The aim of this study was to explore the relationships between lower limb joint kinetics, external force production and starting block performance (normalised average horizontal power, NAHP). Seventeen male sprinters (100 m PB, 10.67 ± 0.32 s) performed maximal block starts from instrumented starting blocks (1000 Hz) whilst 3D kinematics (250 Hz) were also recorded during the block phase. Ankle, knee and hip resultant joint moment and power were calculated at the rear and front leg using inverse dynamics. Average horizontal force applied to the front (r = 0.46) and rear (r = 0.44) block explained 86% of the variance in NAHP. At the joint level, many "very likely" to "almost certain" relationships (r = 0.57 to 0.83) were found between joint kinetic data and the magnitude of horizontal force applied to each block although stepwise multiple regression revealed that 55% of the variance in NAHP was accounted for by rear ankle moment, front hip moment and front knee power. The current study provides novel insight into starting block performance and the relationships between lower limb joint kinetic and external kinetic data that can help inform physical and technical training practices for this skill.

Unusual Presentation of Maydl's Hernia

African Journals Online (AJOL)

Nikhil NBA, Natarajan K, Mohanty A, et al. An. Unusual Case of Maydl's Hernia. Int J Cur Res Rev. 2013;5(6):22-5. 11. Ganesaratnam M. Maydl's hernia: Report of a Series of Seven Cases and Review of Literature. Brit J Surg. 1985;72:737-8. 12. Weledji EP, Mokake M, Ngowe MN. A Rare. Presentation of Maydl's Hernia.

Diphoton excess from hidden U(1 gauge symmetry with large kinetic mixing

Directory of Open Access Journals (Sweden)

Fuminobu Takahashi

2016-09-01

Full Text Available We show that the 750 GeV diphoton excess can be explained by introducing vector-like quarks and hidden fermions charged under a hidden U(1 gauge symmetry, which has a relatively large coupling constant as well as a significant kinetic mixing with U(1Y. With the large kinetic mixing, the standard model gauge couplings unify around 1017 GeV, suggesting the grand unified theory without too rapid proton decay. Our scenario predicts events with a photon and missing transverse momentum, and its cross section is related to that for the diphoton excess through the kinetic mixing. We also discuss other possible collider signatures and cosmology, including various ways to evade constraints on exotic stable charged particles. In some cases where the 750 GeV diphoton excess is due to diaxion decays, our scenario also predicts triphoton and tetraphoton signals.

Unusual lightning electric field waveforms observed in Kathmandu, Nepal, and Uppsala, Sweden

Science.gov (United States)

Adhikari, Pitri Bhakta; Sharma, Shriram; Baral, Kedarnath; Rakov, Vladimir A.

2017-11-01

Unusual lightning events have been observed in Uppsala, Sweden, and Kathmandu, Nepal, using essentially the same electric field measuring system developed at Uppsala University. They occurred in the storms that also generated ;normal; lightning events. The unusual events recorded in Uppsala occurred on one thunderstorm day. Similar events were observed in Kathmandu on multiple thunderstorm days. The unusual events were analyzed in this study assuming them to be positive ground flashes (+CGs), although we cannot rule out the possibility that some or most of them were actually cloud discharges (ICs). The unusual events were each characterized by a relatively slow, negative (atmospheric electricity sign convention) electric field waveform preceded by a pronounced opposite-polarity pulse whose duration was some tens of microseconds. To the best of our knowledge, such unusual events have not been reported in the literature. The average amplitudes of the opposite-polarity pulses with respect to those of the following main waveform were found to be about 33% in Uppsala (N = 31) and about 38% in Kathmandu (N = 327). The average durations of the main waveform and the preceding opposite-polarity pulse in Uppsala were 8.24 ms and 57.1 μs, respectively, and their counterparts in Kathmandu were 421 μs and 39.7 μs. Electric field waveforms characteristic of negative ground flashes (-CGs) were also observed, and none of them exhibited an opposite-polarity pulse prior to the main waveform. Possible origins of the unusual field waveforms are discussed.

NPP unusual events: data, analysis and application

International Nuclear Information System (INIS)

Tolstykh, V.

1990-01-01

Subject of the paper are the IAEA cooperative patterns of unusual events data treatment and utilization of the operating safety experience feedback. The Incident Reporting System (IRS) and the Analysis of Safety Significant Event Team (ASSET) are discussed. The IRS methodology in collection, handling, assessment and dissemination of data on NPP unusual events (deviations, incidents and accidents) occurring during operations, surveillance and maintenance is outlined by the reports gathering and issuing practice, the experts assessment procedures and the parameters of the system. After 7 years of existence the IAEA-IRS contains over 1000 reports and receives 1.5-4% of the total information on unusual events. The author considers the reports only as detailed technical 'records' of events requiring assessment. The ASSET approaches implying an in-depth occurrences analysis directed towards level-1 PSA utilization are commented on. The experts evaluated root causes for the reported events and some trends are presented. Generally, internal events due to unexpected paths of water in the nuclear installations, occurrences related to the integrity of the primary heat transport systems, events associated with the engineered safety systems and events involving human factor represent the large groups deserving close attention. Personal recommendations on how to use the events related information use for NPP safety improvement are given. 2 tabs (R.Ts)

Explaining Away Intuitions

Directory of Open Access Journals (Sweden)

Jonathan Ichikawa

2009-12-01

Full Text Available What is it to explain away an intuition? Philosophers regularly attempt to explain intuitions away, but it is often unclear what the success conditions for their project consist in. I attempt to articulate some of these conditions, taking philosophical case studies as guides, and arguing that many attempts to explain away intuitions underestimate the challenge the project of explaining away involves. I will conclude, therefore, that explaining away intuitions is a more difficult task than has sometimes been appreciated; I also suggest, however, that the importance of explaining away intuitions has often been exaggerated.

Kinetic Typography

DEFF Research Database (Denmark)

van Leeuwen, Theo; Djonov, Emilia

2014-01-01

After discussing broad cultural drivers behind the development of kinetic typography, the chapter outlines an approach to analysing kinetic typography which is based on Halliday's theory of transitivity, as applied by Kress and Van Leeuwen to visual images.......After discussing broad cultural drivers behind the development of kinetic typography, the chapter outlines an approach to analysing kinetic typography which is based on Halliday's theory of transitivity, as applied by Kress and Van Leeuwen to visual images....

Extensive Air Showers with unusual structure

Directory of Open Access Journals (Sweden)

Beznosko Dmitriy

2017-01-01

Full Text Available A total of 23500 Extensive Air Showers (EAS with energies above ∼ 1016 eV have been detected during the ∼3500 hours of the Horizon-T (HT detectors system operations before Aug. 2016. Among these EAS, more than a thousand had an unusual spatial and temporary structure that showed pulses with several maxima (modals or modes from several detection points of the HT at the same time. These modes are separated in time from each other starting from tens to thousands of ns. These EAS have been called multi-modal. Analysis shows that the multi-modal EAS that have been detected by Horizon-T have the following properties: 1. Multi-modal EAS have energy above ∼1017 eV. 2. Pulses with several modes are located at large distances from the EAS axis. An overview of the collected data will be provided. General comments about the unusual structure of the multi-modal EAS will be presented.

Removal of arsenic from simulated groundwater using GAC-Ca in batch reactor: kinetics and equilibrium studies

Energy Technology Data Exchange (ETDEWEB)

Mondal, Prasenjit; Mohanty, Bikash; Majumder, Chandrajit Balo [Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttrakhand (India)

2012-05-15

This paper deals with kinetics and equilibrium studies on the adsorption of arsenic species from simulated groundwater containing arsenic (As(III)/As(V), 1:1), Fe, and Mn in concentrations of 0.188, 2.8, and 0.6 mg/L, respectively, by Ca{sup 2+} impregnated granular activated charcoal (GAC-Ca). Effects of agitation period and initial arsenic concentration on the removal of arsenic species have also been described. Although, most of the arsenic species are adsorbed within 10 h of agitation, equilibrium reaches after {proportional_to}24 h. Amongst various kinetic models investigated, the pseudo second order model is more adequate to explain the adsorption kinetics and film diffusion is found to be the rate controlling step for the adsorption of arsenic species on GAC-Ca. Freundlich isotherm is adequate to explain the adsorption equilibrium. However, empirical polynomial isotherm gives more accurate prediction on equilibrium specific uptakes of arsenic species. Maximum specific uptake (q{sub max}) for the adsorption of As(T) as obtained from Langmuir isotherm is 135 {mu}g/g. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Unusual Cancers of the Head and Neck

Science.gov (United States)

... more information). Unusual Cancers of the Head and Neck Nasopharyngeal Cancer See the PDQ summary on Childhood ... of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ ...

Kinetics of oxidation of H2 and reduction of H2O in Ni-YSZ based solid oxide cells

DEFF Research Database (Denmark)

Ebbesen, Sune Dalgaard; Mogensen, Mogens Bjerg

2012-01-01

Reduction of H2O and oxidation of H2 was studied in a Ni-YSZ electrode supported Solid Oxide Cells produced at DTU Energy conversion (former Risø DTU). Polarisation (i-V) and electrochemical impedance spectroscopic characterisation show that the kinetics for reduction of H 2O is slower compared...... to oxidation of H2. The kinetic differences cannot be explained by the reaction mechanisms which are similar in the two cases but are rather an effect of the thermodynamics. The preliminary analysis performed in this study show that the slow kinetic for reduction is partly related to the endothermic nature...... of the reaction, cooling the active electrode, thereby leading to slower kinetics at low current densities. Likewise, the increased kinetic for oxidation was found to be related to the exothermic nature of the reaction, heating the active electrode, and thereby leading to faster kinetics. At higher current...

Cardiac Failure as an Unusual Presentation in a Patient with History of Amyotrophic Lateral Sclerosis

Directory of Open Access Journals (Sweden)

Mohammad Hasan Namazi

2014-01-01

Full Text Available Amyotrophic lateral sclerosis (ALS is the most well-known form of motor neuron diseases in which both upper and lower motor neurons are involved in this disease. We presented an unusual case of ALS whom had presented with chief complaint of dyspnea. Cardiac failure was diagnosed at the final stage of the ALS disease. The pathogenetic mechanism leading to an elevated occurrence of cardiomyopathy in ALS is not comprehensible. Dilated cardiomyopathy has been explained in some previous studies. Based on the collected data, it was hypothesized that cardiomyopathy is underdiagnosed in the ALS population, probably because symptoms are masqueraded as a result of the patients’ disability. It was suggested that in all motor neuron diseases a serial cardiological evaluation should be executed, including annual echocardiography.

Unusual presentation of perirenal lung metastases

International Nuclear Information System (INIS)

D'Souza, D.L.; Heinze, S.B.; Dowling, R.J.

2006-01-01

Lung cancer is not commonly known to metastasise to the perirenal space, with only five such cases previously published. We present an unusual case of perirenal lung metastases manifesting as diffuse perinephric stranding which to our knowledge has not been described before Copyright (2006) Blackwell Publishing Asia Pty Ltd

On the theory of time dilation in chemical kinetics

Science.gov (United States)

Baig, Mirza Wasif

2017-10-01

The rates of chemical reactions are not absolute but their magnitude depends upon the relative speeds of the moving observers. This has been proved by unifying basic theories of chemical kinetics, which are transition state theory, collision theory, RRKM and Marcus theory, with the special theory of relativity. Boltzmann constant and energy spacing between permitted quantum levels of molecules are quantum mechanically proved to be Lorentz variant. The relativistic statistical thermodynamics has been developed to explain quasi-equilibrium existing between reactants and activated complex. The newly formulated Lorentz transformation of the rate constant from Arrhenius equation, of the collision frequency and of the Eyring and Marcus equations renders the rate of reaction to be Lorentz variant. For a moving observer moving at fractions of the speed of light along the reaction coordinate, the transition state possess less kinetic energy to sweep translation over it. This results in the slower transformation of reactants into products and in a stretched time frame for the chemical reaction to complete. Lorentz transformation of the half-life equation explains time dilation of the half-life period of chemical reactions and proves special theory of relativity and presents theory in accord with each other. To demonstrate the effectiveness of the present theory, the enzymatic reaction of methylamine dehydrogenase and radioactive disintegration of Astatine into Bismuth are considered as numerical examples.

Unusual X-ray burst profiles from 4U/MXB 1636-53

Science.gov (United States)

Sztajno, M.; Truemper, J.; Pietsch, W.; Van Paradijs, J.; Stollman, G.

1985-01-01

During a one day Exosat observation eight X-ray bursts from 4U/MXB 1636-53 are observed. Four of these were very unusual. Their peak fluxes were relatively low, and they showed a distinct double peak in their bolometric flux profiles. These new double-peaked bursts are unexplained by presently available models of X-ray bursts. It is possible that the energy release in these bursts proceeds in two 'steps'. The burst profiles are not the result of an expansion and subsequent contraction of the photosphere of the neutron star. Thus, they are very different from previously observed bursts which do show a double peak in certain energy ranges but not in their bolometric flux profiles; these are satisfactorily explained in terms of photospheric radius expansion and contraction. The anticorrelation between the apparent blackbody radius and blackbody temperature is discussed in terms of the nonPlanckian character of burst spectra and it is concluded that the model calculations reported by London, Taam, and Howard in 1984 give a reasonable first-order description of the observed apparent radius changes in X-ray bursts.

EQUILIBRIUM AND KINETIC PARAMETERS FOR THE SEDIMENTATION OF TARTARIC SALTS IN YOUNG WINES

Directory of Open Access Journals (Sweden)

Ecaterina Covaci

2015-06-01

Full Text Available In young wines potassium hydrogen tartrate is always present in supersaturating concentration and crystallizes spontaneously. The aim of this study is to obtain kinetic parameters, which explain the stability of young wines during the stabilization treatments. The kinetic and equilibrium parameters were evaluated and discussed. The heating factor has a decisive influence on the reaction rate of potassium hydrogen tartrate precipitation in young wines. An increase of temperature leads to a decrease in efficiency of stabilization process and to an enhancement of the activation energy of the system. According to the obtained experimental results, the optimal regime for production and stabilization of young wines has been established.

Reaction kinetic analysis of reactor surveillance data

Energy Technology Data Exchange (ETDEWEB)

Yoshiie, T., E-mail: yoshiie@rri.kyoto-u.ac.jp [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka-fu 590-0494 (Japan); Kinomura, A. [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka-fu 590-0494 (Japan); Nagai, Y. [The Oarai Center, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan)

2017-02-15

In the reactor pressure vessel surveillance data of a European-type pressurized water reactor (low-Cu steel), it was found that the concentration of matrix defects was very high, and a large number of precipitates existed. In this study, defect structure evolution obtained from surveillance data was simulated by reaction kinetic analysis using 15 rate equations. The saturation of precipitation and the growth of loops were simulated, but it was not possible to explain the increase in DBTT on the basis of the defect structures. The sub-grain boundary segregation of solutes was discussed for the origin of the DBTT increase.

Promoting Graphical Thinking: Using Temperature and a Graphing Calculator to Teach Kinetics Concepts

Science.gov (United States)

Cortes-Figueroa, Jose E.; Moore-Russo, Deborah A.

2004-01-01

A combination of graphical thinking with chemical and physical theories in the classroom is encouraged by using the Calculator-Based Laboratory System (CBL) with a temperature sensor and graphing calculator. The theory of first-order kinetics is logically explained with the aid of the cooling or heating of the metal bead of the CBL's temperature…

Mixtures of rubber tyre and plastic wastes pyrolysis: A kinetic study

International Nuclear Information System (INIS)

Miranda, Miguel; Cabrita, I.; Pinto, Filomena; Gulyurtlu, I.

2013-01-01

The study performed aimed at analysing possible routes for pyrolysis reaction mechanisms of polymeric materials namely RT (rubber tyre) and plastic wastes (PE (polyethylene), PP (polypropylene) and PS (polystyrene)). Consequently, and seeking sustainable transformation of waste streams into valuable chemicals and renewable liquid fuels, mixture of 30% RT, 20% PE, 30% PP and 20% PS was subjected to pyrolysis. Different kinetic models were studied using experimental data. None of the mechanisms found in literature led to a numerical adjustment and different pathways were investigated. Kinetic studies were performed aiming to evaluate direct conversions into new solid, liquid and gaseous products and if parallel reactions and/or reversible elementary steps should be included. Experiments were performed in batch system at different temperatures and reaction times. Kinetic models were evaluated and reaction pathways were proposed. Models reasonably fit experimental data, allow explaining wastes thermal degradation. Kinetic parameters were estimated for all temperatures and dependence of Ea and pre-exponential factor on temperature was evaluated. The rate constant of some reactions exhibited nonlinear temperature dependence on the logarithmic form of Arrhenius law. This fact strongly suggests that temperature has a significant effect on reaction mechanism of pyrolysis of mixtures of rubber tyre and plastic wastes. - Highlights: • Kinetic study of rubber tyre (RT) and different plastic wastes (PE, PP and PS) was performed in batch reactor. • Definition of possible pathways taken into account for the formation of final products. • Kinetic parameters were estimated. • The effect of reaction temperature and reaction time on liquid composition was performed

salmonella typhi spondyutis: an unusual presentation

African Journals Online (AJOL)

It was relieved by lying flat. She had pre- viously been admitted to King Edward VIII Hospital in. May 1969 with a cough, chest and abdominal pain, ... foot and cranium may be the sites of skeletal involvement. Our case shows several unusual features. Sickle-cell anaemia and haemoglobinopathy were absent. Although.

Unusual Cutaneous Manifestation of Tuberous Sclerosis

Directory of Open Access Journals (Sweden)

K C Shah

1980-01-01

Full Text Available Cutaneous manifestations are found in 60 to 70% cases of tuberous sclerosis and consist of adenoma sebaceum, periungual fibromatas, cafe au lait spots, shagreen patches and white macules. Our patient showed unusual skin manifestations like spotty pigmentation on the chest, back and abdomen and hyperkeratosis palmaris et plantaris.

Kinetic study of enzymatic hydrolysis of potato starch

Directory of Open Access Journals (Sweden)

Óscar Fernando Castellanos Domínguez

2004-01-01

Full Text Available This article describes the kinetic study of potato starch enzymatic hydrolysis using soluble enzymes (Novo Nordisk. Different assays divided into four groups were used: reaction time (with which it was possible to reduce the 48-72 hour duration reported in the literature to 16 hours with comparable productivity levels; selecting the set of enzymes to be used (different types were evaluated - BAN and Termamyl as alfa-amylases during dextrinisation stage, and AMG, Promozyme and Fungamyl for sacarification reaction- identifying those presenting the best performance during hydrolysis.Reaction conditions were optimised for the process's two stages (destrinisation and sacarification. Enzyme dose, calcium cofactor concentration, pH, temperature and agitation speed were studied for the first stage. Enzyme ratio, pH and agitation speed were studied for sacarification; the latter parameter reported values having no antecedents in the literature (60 rpm and 30 rpm for first and second reactions, respectively. Michaelis Menten kinetics were calculated once conditions had been optimised, varying substrate from 10-50% P/V, obtaining km and Vmax kinetic parameters for each reaction. A kinetic model was found according to local working conditions which was able to explain potato starch conversion to glucose syrup, achieving 96 dextrose equivalents by the end of the reaction, being well within the maximum range reported in the literature (94-98.Laboratory equipment was constructed prior to carrying out assays which was able to reproduce and improve the conditions reported in the literature, making it a useful, reliable tool for use in assays returning good results.

Unusual causes of mechanical small bowel obstruction

International Nuclear Information System (INIS)

Shatnawi, Nawaf J.; Bani-Hani, Kamal E.

2005-01-01

We herein report our experience regarding unusual causes of bowel obstruction to increase the awareness of surgeons regarding this disease. From 1991 to 2003, we had experience at the University affiliated hospitals, northern Jordan with 24 patients with small bowel obstruction resulting from unusual causes. We retrospectively reviewed the medical records of these patients with regards to the mode of presentation, cause of obstruction, radiological and operative findings, management and outcome. We recorded 15 patients who underwent previous abdominal surgery. Preoperative diagnosis was correct in only one patient with an internal hernia, but the abdominal CT scan suggested the diagnosis in 5 of the 9 patients who had the scan. The final diagnosis was internal hernias in 11 patients, foreign bodies in 5, ischemic strictures in 3, carcinoid tumors in 2, endometriosis in 2, and metastatic deposit from interstitial bladder carcinoma in one patient. Nine of the 12 patients with recurrent obstruction had either short course or recurrence obstruction during the same hospital admission. W carried out bowel resections in 15 patients (5 resections were due to bowel strangulation). Post operative death occurred in 4 patients. Awareness of these rare causes of intestinal obstruction even in patients with previous abdominal operation might improve the outcome. The tentative diagnosis of adhesion obstruction in patients with unusual obstructive etiology might lead to a higher rate of gangrenous complications. Rigorous preoperative evaluation including careful history and early abdominal CT may show the obstructive cause. (author)

Fractal-like kinetics, a possible link between preconditioning and sepsis immunodepression. On the chemical basis of innate immunity.

Science.gov (United States)

Vasilescu, C; Olteanu, M; Flondor, P

2012-01-01

In a recent paper the authors hypothesized that the so called fractal-like enzyme kinetics of intracellular reactions may explain the preconditioning effect in biology (Vasilescu C, Olteanu M, Flondor P, Revue Roumaine de Chimie. 2011; 56(7): 751-7). Inside cells the reaction kinetics is very well described by fractal-like kinetics. In the present work some clinical implications of this model are analyzed. Endotoxin tolerance is a particular case of preconditioning and shows similarities with the immunodepression seen in some sepsis patients. This idea offers a theoretical support for modulation of the enzymatic activity of the cell by changing the fractal dimension of the cytoskeleton.

NDMA formation by chloramination of ranitidine: Kinetics and mechanism

KAUST Repository

Le Roux, Julien

2012-10-16

The kinetics of decomposition of the pharmaceutical ranitidine (a major precursor of NDMA) during chloramination was investigated and some decomposition byproducts were identified by using high performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The reaction between monochloramine and ranitidine followed second order kinetics and was acid-catalyzed. Decomposition of ranitidine formed different byproducts depending on the applied monochloramine concentration. Most identified products were chlorinated and hydroxylated analogues of ranitidine. In excess of monochloramine, nucleophilic substitution between ranitidine and monochloramine led to byproducts that are critical intermediates involved in the formation of NDMA, for example, a carbocation formed from the decomposition of the methylfuran moiety of ranitidine. A complete mechanism is proposed to explain the high formation yield of NDMA from chloramination of ranitidine. These results are of great importance to understand the formation of NDMA by chloramination of tertiary amines. © 2012 American Chemical Society.

Magnetic vortex excitation as spin torque oscillator and its unusual trajectories

Science.gov (United States)

Natarajan, Kanimozhi; Muthuraj, Ponsudana; Rajamani, Amuda; Arumugam, Brinda

2018-05-01

We report an interesting observation of unusual trajectories of vortex core oscillations in a spin valve pillar. Micromagnetic simulation in the composite free layer spin valve nano-pillar shows magnetic vortex excitation under critical current density. When current density is slightly increased and wave vector is properly tuned, for the first time we observe a star like and square gyration. Surprisingly this star like and square gyration also leads to steady, coherent and sustained oscillations. Moreover, the frequency of gyration is also very high for this unusual trajectories. The power spectral analysis reveals that there is a marked increase in output power and frequency with less distortions. Our investigation explores the possibility of these unusual trajectories to exhibit spin torque oscillations.

No Laughing Matter: Gelastic Migraine and Other Unusual Headache Syndromes.

Science.gov (United States)

Mathew, Paul G; Robertson, Carrie E

2016-05-01

Primary and secondary headache disorders have established diagnostic criteria in the International Classification of Headache Disorders IIIb, as well as classic findings, which although not part of the formal criteria are often suggestive of a particular diagnosis. At times, headache disorders can involve unusual symptoms that lack an identifiable secondary cause. This review will discuss some of these unusual symptoms, including headache associated auditory and olfactory symptoms, as well as two case reports involving gelastic migraine and migrainous thoracalgia.

Explaining Physics – What Skills does a good Explainer Need?

CERN Multimedia

CERN. Geneva; Bartels, Hauke

2018-01-01

Explaining physics in a way that it is both scientifically correct and comprehensible is a highly demanding practice. But are explanations an effective way to teach physics? Under which circumstances should a physics teacher explain – and is there such a thing as a guideline for effective instructional explanations? Of course, explaining is more than just presenting content knowledge in clear language – but what more? In our talk, we want to discuss empirical studies on instructional explanations from science education and psychology to address these questions. Among other things, we will refer to results from a large study aiming to research whether teacher education contributes to the development of explaining skills. Besides, we will give insights into a project that seeks to measure explaining skills with an interactive online test instrument.

Recent developments in thermoluminescence kinetics: applications to other thermally stimulated processes

International Nuclear Information System (INIS)

Levy, P.W.

1985-01-01

Recent thermoluminescence (TL) studies indicate that many kinetic properties are not in accord with the well known 1st and 2nd order TL kinetic equations. For example, the usual equations do not describe: (1) the shape of certain single glow peaks. (2) The shape of glow peaks in many glow curves containing more than one glow peak. (3) The dependence of the peak temperature, the FWHM, the shape, and other properties on the pre-measurement dose. However, the properties of some single glow peaks are precisely described, or closely approximated by, the more general basic equation from which the usual 1st and 2nd order equations are obtained as special cases. Furthermore, glow curves containing more than one glow peak are described by a system of equations that includes interactions between different types of traps and is a straightforward extension of the general one peak equation. This system - called Interactive Kinetics - accounts for most properties, and explains many anomalies, associated with glow curves containing more than one glow peak. It is particularly convenient for computerized analysis procedures. Lastly, it is suggested that other thermally stimulated processes depend on analogous interactions and are describable by similar sets of kinetic equations that are convenient for computer analysis. 11 refs., 2 figs

Unusual Metastases in Renal Cell Carcinoma: A Single Institution Experience and Review of Literature

Science.gov (United States)

Villarreal-Garza, Cynthia; Perez-Alvarez, Sandra I.; Gonzalez-Espinoza, Ivan R.; Leon-Rodriguez, Eucario

2010-01-01

Background To report location and management of atypical metastases from renal cell carcinoma (RCC) in the Instituto Nacional de Ciencias Medicas e Investigacion Salvador Zubiran (INCMNSZ) in Mexico City. Methods Between 1987 to 2009, 545 patients with RCC were retrospectively identified at the INCMNSZ. Patients with unusual metastases confirmed by histopathology were analyzed. Epidemiological, clinical, diagnosis, treatment and outcome data were reviewed. Results Sixty patients developed 98 unusual metastases secondary to RCC. The group was comprised of 35 men (58.3%), with a median age of 60 years at diagnosis. Metachronous unusual metastases with primary renal cancer were observed in 37 individuals (61.7%). Median time from primary RCC diagnosis to the first unusual metastasis was 16.5 months. Median survival from diagnosis of the first unusual metastasis to death was 5.0 months (CI 95%: 2.8-7.2 months). Patients with an initial solitary metastatic lesion in an unusual site (28.3%) had a better survival compared to patients who primarily presented with multiple metastases, 17.0 (CI 95%: 6.1-27.9) Vs 3.0 months (CI 95%: 0.9-5.1), p = 0.001. Unusual metastasis resection (21 patients) improved survival, 25.0 (CI 95%: 5.1-44.9) Vs 3.0 months (CI 95%: 0.8-5.2), p < 0.0001. No survival difference was observed between localization of unsual metastases (p = 0.72). Conclusions In patients with advanced RCC we suggest an individual diagnostic and surgical approach to achieve complete resection with disease-free margins, even in the presence of unusual metastatic sites, multifocality, or history of metastasectomy. These strategy might provide not only palliation for symptoms, but an opportunity for meaningful disease free and overall survival. PMID:29147198

Cesium removal and kinetics equilibrium: Precipitation kinetics

International Nuclear Information System (INIS)

Barnes, M.J.

1999-01-01

This task consisted of both non-radioactive and radioactive (tracer) tests examining the influence of potentially significant variables on cesium tetraphenylborate precipitation kinetics. The work investigated the time required to reach cesium decontamination and the conditions that affect the cesium precipitation kinetics

Normothermic thyroid storm: an unusual presentation

Science.gov (United States)

Sabir, Anas Ahmad; Sada, Kabiru; Yusuf, Bashir O.; Aliyu, Idris

2016-01-01

Thyroid storm is a rare life-threatening emergency due to thyrotoxicosis. A 30-year-old female presented with restlessness, tachycardia and vomiting but with normothermia which is an unusual presentation. There is the need for clinicians to be aware of atypical clinical features that can make the diagnosis of thyroid storm difficult. PMID:27540465

Explaining an Unusually Fast Parasitic Enzyme: Folate Tail-Binding Residues Dictate Substrate Positioning and Catalysis in Cryptosporidium hominis Thymidylate Synthase

Energy Technology Data Exchange (ETDEWEB)

Martucci,W.; Vargo, M.; Anderson, K.

2008-01-01

The essential enzyme TS-DHFR from Cryptosporidium hominis undergoes an unusually rapid rate of catalysis at the conserved TS domain, facilitated by two nonconserved residues, Ala287 and Ser290, in the folate tail-binding region. Mutation of these two residues to their conserved counterparts drastically affects multiple steps of the TS catalytic cycle. We have determined the crystal structures of all three mutants (A287F, S290G, and A287F/S290G) in complex with active site ligands dUMP and CB3717. The structural data show two effects of the mutations: an increased distance between the ligands in the active site and increased flexibility of the folate ligand in the partially open enzyme state that precedes conformational change to the active catalytic state. The latter effect is able to be rescued by the mutants containing the A287F mutation. In addition, the conserved water network of TS is altered in each of the mutants. The structural results point to a role of the folate tail-binding residues in closely positioning ChTS ligands and restricting ligand flexibility in the partially open state to allow for a rapid transition to the active closed state and enhanced rate of catalysis. These results provide an explanation on how folate tail-binding residues at one end of the active site affect long-range interactions throughout the TS active site and validate these residues as targets for species-specific drug design.

The unusual practices within some Neo-Pentecostal churches in South Africa: Reflections and recommendations

Directory of Open Access Journals (Sweden)

Mookgo S. Kgatle

2017-09-01

Full Text Available This article reflects and makes recommendations on the recent unusual practices within some Neo-Pentecostal churches in South Africa. Neo-Pentecostal churches in South Africa refer to churches that have crossed denominational boundaries. These churches idolise the miraculous, healing, deliverance and enactment of bizarre church performances often performed by charismatic and highly influential spiritual leaders. There have been unusual practices within some Neo-Pentecostal churches that include, among others, the eating of grass, eating of snakes, drinking of petrol, spraying of Doom on the congregants and other experiences. There are many possible theological, psychological and socio-economic explanations for these unusual practices. Given the facts that many South Africans experience various socio-economic challenges, it is argued here that the socio-economic factor is the main explanation for the support of these unusual practices. The unusual practices within some Neo-Pentecostal churches in South Africa are critically unpacked by looking at various churches where the incidents happened. The possible theological, psychological and socio-economic explanations for such practices are outlined in detail. Recommendations are made based on the scientific findings on the unusual practices.

Trisomy 2p: Analysis of unusual phenotypic findings

Energy Technology Data Exchange (ETDEWEB)

Lurie, I.W.; Ilyina, H.G.; Gurevich, D.B. [Belorussian Research Institute of Hereditary Disease, Minsk (Russian Federation)] [and others

1995-01-16

We present three probands with partial trisomies 2p21-23 due to ins(4;2)(q21;p21p23) pat, 2p23-pter due to t(2;4)(p23;q35)mat, and 2p21-pter due to t(2;11)(p21;q23.3)mat. More than 50 cases of partial trisomy 2p have been reviewed and some abnormalities, unusual for most other types of structural autosomal imbalance, have been found in patients with inherited forms of 2p trisomy and in their non-karyotyped sibs. Neural tube defects (anencephaly, occipital encephalocele, and spina bifida) were found in five probands and 4/6 affected non-karyotyped sibs. The only triplicated segment common to all was 2p24. Different forms of {open_quotes}broncho-pulmonary a/hypoplasia{close_quotes} (including two cases of lung agenesis) were described in four patients (overlapping triplicated segment was 2p21-p25). Three patients (with overlapping triplicated segment 2p23-p25) had diaphragmatic hernia. Abnormal rotation of the heart or L-transposition of large vessels (with or without visceral heterotaxia) was found in two infants (overlapping triplicated segment 2p23-p24). In two patients with common triplicated segment 2p22.3-p25, neuroblastoma has been described. The occurrence of all these defects may be explained either by the action of the same gene(s) mapped to 2p24 or by action of some independent factors located in different segments of the short arm. Although the latter hypothesis is much less probable, it can not be rejected at the present time. We propose the existence of a genetic system controlling surveillance of an abnormal embryo to explain the phenotypic differences between patients with the same imbalance within a family. In some {open_quotes}restrictive{close_quotes} combinations the abnormal embryos will die, although in {open_quotes}permissive{close_quotes} combinations they can survive. 47 refs., 2 figs., 3 tabs.

Giant seborrheic keratosis of the face – an unusual presentation

Directory of Open Access Journals (Sweden)

Koh Khai Luen

2016-04-01

Full Text Available Seborrheic keratosis is the most common benign epidermal lesion in the world, especially among the elderly. Its inherent benign nature has precluded the need to remove it for medical reasons. Most of the concerns presented to dermatologists or plastic surgeons are of cosmetic reasons, besides some unusual appearances that necessitate cutaneous malignancy evaluation. Unusually large sizes of seborrheic keratosis are rarely reported, and its clinical significance is largely unknown. It has been proven by recent molecular studies that seborrheic keratosis is true neoplasia rather than a mere epidermal hyperplasia, and various authors have reported several cases of concomitant malignancy arising from seborrheic keratosis. Plastic surgeon expertise is often required when faced with an extensive lesion, requiring reconstructive procedures to preserve good aesthetic and functional outcomes. The purpose of this review is to report a case of an unusually large seborrheic keratosis on the face, highlighting its clinical relevance and surgical management.

Rigor mortis in an unusual position: Forensic considerations.

Science.gov (United States)

D'Souza, Deepak H; Harish, S; Rajesh, M; Kiran, J

2011-07-01

We report a case in which the dead body was found with rigor mortis in an unusual position. The dead body was lying on its back with limbs raised, defying gravity. Direction of the salivary stains on the face was also defying the gravity. We opined that the scene of occurrence of crime is unlikely to be the final place where the dead body was found. The clues were revealing a homicidal offence and an attempt to destroy the evidence. The forensic use of 'rigor mortis in an unusual position' is in furthering the investigations, and the scientific confirmation of two facts - the scene of death (occurrence) is different from the scene of disposal of dead body, and time gap between the two places.

Kinetic Physics of the Solar Corona and Solar Wind

Directory of Open Access Journals (Sweden)

Marsch Eckart

2006-07-01

Full Text Available Kinetic plasma physics of the solar corona and solar wind are reviewed with emphasis on the theoretical understanding of the in situ measurements of solar wind particles and waves, as well as on the remote-sensing observations of the solar corona made by means of ultraviolet spectroscopy and imaging. In order to explain coronal and interplanetary heating, the microphysics of the dissipation of various forms of mechanical, electric and magnetic energy at small scales (e.g., contained in plasma waves, turbulences or non-uniform flows must be addressed. We therefore scrutinise the basic assumptions underlying the classical transport theory and the related collisional heating rates, and also describe alternatives associated with wave-particle interactions. We elucidate the kinetic aspects of heating the solar corona and interplanetary plasma through Landau- and cyclotron-resonant damping of plasma waves, and analyse in detail wave absorption and micro instabilities. Important aspects (virtues and limitations of fluid models, either single- and multi-species or magnetohydrodynamic and multi-moment models, for coronal heating and solar wind acceleration are critically discussed. Also, kinetic model results which were recently obtained by numerically solving the Vlasov–Boltzmann equation in a coronal funnel and hole are presented. Promising areas and perspectives for future research are outlined finally.

Heparin kinetics

International Nuclear Information System (INIS)

Swart, C.A.M. de.

1983-01-01

The author has studied the kinetics of heparin and heparin fractions after intravenous administration in humans and in this thesis the results of this study are reported. Basic knowledge about the physico-chemical properties of heparin and its interactions with proteins resulting in anticoagulant and lipolytic effects are discussed in a review (chapter II), which also comprises some clinical aspects of heparin therapy. In chapter III the kinetics of the anticoagulant effect are described after intravenous administration of five commercial heparin preparations. A mathematical model is presented that fits best to these kinetics. The kinetics of the anticoagulant and lipolytic effects after intravenous injection of various 35 S-radiolabelled heparin fractions and their relationship with the disappearance of the radiolabel are described in chapter IV. Chapter V gives a description of the kinetics of two radiolabels after injection of in vitro formed complexes consisting of purified, 125 I-radiolabelled antithrombin III and various 35 S-radiolabelled heparin fractions. (Auth.)

Pediatric sciatic neuropathies due to unusual vascular causes

NARCIS (Netherlands)

Srinivasan, Jayashri; Escolar, Diane; Ryan, Monique; Darras, Basil; Jones, H. Royden

Four cases of pediatric sciatic neuropathies due to unusual vascular mechanisms are reported. Pediatric sciatic neuropathies were seen after umbilical artery catheterization, embolization of arteriovenous malformation, meningococcemia, and hypereosinophilic vasculitis. Electrophysiologic studies

Moderation and absorption effects on hot replacement reactions of 38Cl atoms in mixtures of ortho-dichlorobenzene and hexafluorobenzene

International Nuclear Information System (INIS)

Berei, K.; Gado, J.; Kereszturi, A.; Szatmary, Z.; Vass, Sz.

1989-10-01

Conditions are given for the equivalence of the Estrup-Wolfgang description of the hot atom reaction kinetics with the first-order Hurwitz approximation in the neutron slowing down theory. Conclusions are drawn for the applicability of this approach for describing hot atom replacement processes in reactive mixtures. Analytical and numerical calculations were carried out to explain an unusual concentration dependence of 38 Cl-for-Cl substitution, found experimentally in liquid binary mixtures of ortho-dichlorobenzene and hexafluorobenzene. (author) 39 refs.; 4 figs.; 2 tabs

The Relationship between Clinical Presentation and Unusual Sensory Interests in Autism Spectrum Disorders: A Preliminary Investigation

Science.gov (United States)

Zachor, Ditza A.; Ben-Itzchak, Esther

2014-01-01

Unusual responses to sensory stimuli have been described in autism spectrum disorder (ASD).The study examined the frequencies of "unusual sensory interests" and "negative sensory responses" and their relation to functioning in a large ASD population (n = 679). Having "unusual sensory interests" was reported in 70.4%…

Unusual presentation of cutaneous leiomyoma

Directory of Open Access Journals (Sweden)

Sapnashree Bhaskar

2014-01-01

Full Text Available Herein, we report a case of leiomyoma cutis because of its rarity and unusual presentation. The case presented with a solitary leiomyoma lesion which was painless. However, the adjacent normal appearing area was tender. A biopsy of the lesion as well as of a portion of the adjacent normal appearing area was taken, which confirmed the diagnosis of cutaneous leiomyoma. This may suggest the dormant nature of the disease which has not yet become apparent.

Unusual skeletal metastases from myxoid liposarcoma only detectable by MR imaging

International Nuclear Information System (INIS)

Ishii, T.; Ueda, T.; Myoui, A.; Tamai, N.; Hosono, N.; Yoshikawa, H.

2003-01-01

We present two cases of skeletal metastases from myxoid liposarcoma, occurring several years after treatment of the primary tumors in the lower limb. The present two case reports have unusual radiological features only detectable by MR imaging and not by plain radiographs or bone scans. From the present two cases, we found that a negative plain radiograph of the spine or a negative bone scan could not exclude skeletal metastases from myxoid liposarcoma, and MRI was a more sensitive screening procedure for their detection, especially in T1-weighted images. Unusual radiological features of skeletal metastases from myxoid liposarcoma are not well documented and only a few cases have been previously reported. Our aim is to document two more patients exhibiting the unusual radiological features of skeletal metastases from myxoid liposarcoma to improve their early detection and management. (orig.)

The combustion kinetics of the lignocellulosic biofuel, ethyl levulinate

KAUST Repository

Ghosh, Manik Kumer; Howard, Mí cheá l Sé amus; Zhang, Yingjia; Djebbi, Khalil; Capriolo, Gianluca; Farooq, Aamir; Curran, Henry J.; Dooley, Stephen

2018-01-01

Ethyl levulinate (Ethyl 4-oxopentanoate) is a liquid molecule at ambient temperature, comprising of ketone and ethyl ester functionalities and is one of the prominent liquid fuel candidates that may be easily obtained from lignocellulosic biomass. The combustion kinetics of ethyl levulinate have been investigated. Shock tube and rapid compression machine apparatuses are utilised to acquire gas phase ignition delay measurements of 0.5% ethyl levulinate/O2 mixtures at ϕ = 1.0 and ϕ = 0.5 at ∼ 10 atm over the temperature range 1000–1400 K. Ethyl levulinate is observed not to ignite at temperatures lower than ∼1040 K in the rapid compression machine. The shock tube and rapid compression machine data are closely consistent and show ethyl levulinate ignition delay to exhibit an Arrhenius dependence to temperature. These measurements are explained by the construction and analysis of a detailed chemical kinetic model. The kinetic model is completed by establishing thermochemical-kinetic analogies to 2-butanone, for the ethyl levulinate ketone functionality, and to ethyl propanoate for the ethyl ester functionality. The so constructed model is observed to describe the shock tube data very accurately, but computes the rapid compression machine data set to a lesser but still applicable fidelity. Analysis of the model suggests the autooxidation mechanism of ethyl levulinate to be entirely dominated by the propensity for the ethyl ester functionality to unimolecularly decompose to form levulinic acid and ethylene. The subsequent reaction kinetics of these species is shown to dictate the overall rate of the global combustion reaction. This model is then use to estimate the Research and Motored Octane Numbers of ethyl levulinate to be ≥97.7 and ≥ 93, respectively. With this analysis ethyl levulinate would be best suited as a gasoline fuel component, rather than as a diesel fuel as suggested in the literature. Indeed it may be considered to be useful as an

The combustion kinetics of the lignocellulosic biofuel, ethyl levulinate

KAUST Repository

Ghosh, Manik Kumer

2018-04-04

Ethyl levulinate (Ethyl 4-oxopentanoate) is a liquid molecule at ambient temperature, comprising of ketone and ethyl ester functionalities and is one of the prominent liquid fuel candidates that may be easily obtained from lignocellulosic biomass. The combustion kinetics of ethyl levulinate have been investigated. Shock tube and rapid compression machine apparatuses are utilised to acquire gas phase ignition delay measurements of 0.5% ethyl levulinate/O2 mixtures at ϕ = 1.0 and ϕ = 0.5 at ∼ 10 atm over the temperature range 1000–1400 K. Ethyl levulinate is observed not to ignite at temperatures lower than ∼1040 K in the rapid compression machine. The shock tube and rapid compression machine data are closely consistent and show ethyl levulinate ignition delay to exhibit an Arrhenius dependence to temperature. These measurements are explained by the construction and analysis of a detailed chemical kinetic model. The kinetic model is completed by establishing thermochemical-kinetic analogies to 2-butanone, for the ethyl levulinate ketone functionality, and to ethyl propanoate for the ethyl ester functionality. The so constructed model is observed to describe the shock tube data very accurately, but computes the rapid compression machine data set to a lesser but still applicable fidelity. Analysis of the model suggests the autooxidation mechanism of ethyl levulinate to be entirely dominated by the propensity for the ethyl ester functionality to unimolecularly decompose to form levulinic acid and ethylene. The subsequent reaction kinetics of these species is shown to dictate the overall rate of the global combustion reaction. This model is then use to estimate the Research and Motored Octane Numbers of ethyl levulinate to be ≥97.7 and ≥ 93, respectively. With this analysis ethyl levulinate would be best suited as a gasoline fuel component, rather than as a diesel fuel as suggested in the literature. Indeed it may be considered to be useful as an

Several unusual cases of child abuse.

Science.gov (United States)

Palmer, H; Weston, J T

1976-10-01

All childhood deaths which occurred in New Mexico during 1974 and 1975 were reviewed. Nine fatal instances of abuse were identified representing the entire spectrum of physical abuse: neglect, abuse in a single episode of injury, repetitive abuse, or sexual abuse. Several cases are summarized. These are unusual either in the distribution of pathologic findings or in the problems encountered in court presentation.

Mammography. Advanced, intensive course and atlas. Senology, screening, radiographic morphology, differential diagnosis, unusual findings, false treatment as a case in court

International Nuclear Information System (INIS)

Barth, V.

1994-01-01

Differential diagnosis is the focal point of this richly illustrated atlas intended for experienced mammographers. Mammographs of different histology but with similar features are presented side by side for easy comparison; pinpointed questions accompanying the pictures are guiding the reader to systematically develop the differential dioagnosis, with correct answers being given on the next pages together with characteristic and typical pictures explaining the correct and false diagnoses, including clinical photographs and sonographic images. Unusual mammographic findings are discussed in a separate chapter, and other chapters deal with the history of senology and with problems encountered in examinations for early diagnosis, as reported in the German Mammography Study and in international screening projects. The concluding chapter deals with legal aspects such as liability of the physician in case of missed detection of tumors, explaining the most frequent causes of false diagnosis as a guide to preventing errors, and giving practical hints and information for the event of damages being claimed from a physician. (orig.) [de

Case Report: Unusual computed tomographic features of ...

African Journals Online (AJOL)

A case report of a 57-year old woman who presented with signs and symptoms of intracranial mass. Computed tomographic (CT) and clinical features were unusual and suggestive of a parasaggital Meningioma. However an accurate diagnosis of a tuberculoma was made at surgery and histopathological examination.

Kinetics and mechanism of styrene epoxidation by chlorite: role of chlorine dioxide.

Science.gov (United States)

Leigh, Jessica K; Rajput, Jonathan; Richardson, David E

2014-07-07

An investigation of the kinetics and mechanism for epoxidation of styrene and para-substituted styrenes by chlorite at 25 °C in the pH range of 5-6 is described. The proposed mechanism in water and water/acetonitrile includes seven oxidation states of chlorine (-I, 0, I, II, III, IV, and V) to account for the observed kinetics and product distributions. The model provides an unusually detailed quantitative mechanism for the complex reactions that occur in mixtures of chlorine species and organic substrates, particularly when the strong oxidant chlorite is employed. Kinetic control of the reaction is achieved by the addition of chlorine dioxide to the reaction mixture, thereby eliminating a substantial induction period observed when chlorite is used alone. The epoxidation agent is identified as chlorine dioxide, which is continually formed by the reaction of chlorite with hypochlorous acid that results from ClO produced by the epoxidation reaction. The overall stoichiometry is the result of two competing chain reactions in which the reactive intermediate ClO reacts with either chlorine dioxide or chlorite ion to produce hypochlorous acid and chlorate or chloride, respectively. At high chlorite ion concentrations, HOCl is rapidly eliminated by reaction with chlorite, minimizing side reactions between HOCl and Cl2 with the starting material. Epoxide selectivity (>90% under optimal conditions) is accurately predicted by the kinetic model. The model rate constant for direct reaction of styrene with ClO2(aq) to produce epoxide is (1.16 ± 0.07) × 10(-2) M(-1) s(-1) for 60:40 water/acetonitrile with 0.20 M acetate buffer. Rate constants for para substituted styrenes (R = -SO3(-), -OMe, -Me, -Cl, -H, and -NO2) with ClO2 were determined. The results support the radical addition/elimination mechanism originally proposed by Kolar and Lindgren to account for the formation of styrene oxide in the reaction of styrene with chlorine dioxide.

Kinetics of transuranium element oxidation-reduction reactions in solution

International Nuclear Information System (INIS)

Gourisse, D.

1966-09-01

A review of the kinetics of U, Np, Pu, Am oxidation-reduction reactions is proposed. The relations between the different activation thermodynamic functions (compensatory effect, formal entropy of the activated complex, magnitude of reactions velocities) are considered. The effects of acidity, ionic strength deuterium and mixed solvents polarity on reactions rates are described. The effect of different anions on reactions rates are explained by variations of the reaction standard free energy and variations of the activation free energy (coulombic interactions) resulting from the complexation of dissolved species by these anions. (author) [fr

Peroneal Arteriovenous Fistula and Pseudoaneurysm: An Unusual Presentation

Directory of Open Access Journals (Sweden)

Kevin C. Ching

2014-01-01

Full Text Available Peroneal artery arteriovenous fistulas and pseudoaneurysms are extremely rare with the majority of reported cases due to penetrating, orthopedic, or iatrogenic trauma. Failure to diagnose this unusual vascular pathology may lead to massive hemorrhage or limb threatening ischemia. We report an interesting case of a 14-year-old male who presented with acute musculoskeletal pain of his lower extremity. Initial radiographs were negative. Further imaging workup revealed a peroneal arteriovenous fistula with a large pseudoaneurysm. After initial endovascular intervention was unsuccessful, the vessels were surgically ligated in the operating room. Pathology revealed papillary endothelial hyperplasia consistent with an aneurysm and later genetic testing was consistent with Ehlers-Danlos syndrome Type IV. This case illustrates an unusual cause of acute atraumatic musculoskeletal pain and uncommon presentation of Ehlers-Danlos syndrome.

An unusual case of calcineurine inhibitor pain syndrome.

Science.gov (United States)

Nickavar, Azar; Mehrazma, Mitra; Hallaji, Farideh

2014-09-01

Cyclosporine induced pain syndrome (CIPS) is a newly diagnosed complication of calcineurine inhibitors, mainly observed in solid organ and hematopoetic transplantations. The present case is a male child with steroid resistant nephrotic syndrome on low therapeutic level cyclosporine treatment. He presented with intractable and debilitating leg pain, with no reported history of previous injury or trauma. The pain was reluctant to antimicrobial and sedative treatment. MRI revealed bone marrow and soft tissue edema in the mid shaft of patient's right leg. Inspite of unusual manifestations, CIPS was suggested and cyclosporine discontinued. However, the pain did not improve and was resistant to calcium blocker. Subsequently, core decompression was performed as an unusual treatment of CIPS, revealing normal bone morphology. The pain improved rapidly and the patient was discharged a few days later.

Cutaneous sporotrichosis: Unusual clinical presentations

Directory of Open Access Journals (Sweden)

Mahajan Vikram

2010-01-01

Full Text Available Three unusual clinical forms of sporotrichosis described in this paper will be a primer for the clinicians for an early diagnosis and treatment, especially in its unusual presentations. Case 1, a 52-year-old man, developed sporotrichosis over pre-existing facial nodulo-ulcerative basal cell carcinoma of seven-year duration, due to its contamination perhaps from topical herbal pastes and lymphocutaneous sporotrichosis over right hand/forearm from facial lesion/herbal paste. Case 2, a 25-year-old woman, presented with disseminated systemic-cutaneous, osteoarticular and possibly pleural (effusion sporotrichosis. There was no laboratory evidence of tuberculosis and treatment with anti-tuberculosis drugs (ATT did not benefit. Both these cases were diagnosed by histopathology/culture of S. schenckii from tissue specimens. Case 3, a 20-year-old girl, had multiple intensely pruritic, nodular lesions over/around left knee of two-year duration. She was diagnosed clinically as a case of prurigo nodularis and histologically as cutaneous tuberculosis, albeit, other laboratory investigations and treatment with ATT did not support the diagnosis. All the three patients responded well to saturated solution of potassium iodide (SSKI therapy. A high clinical suspicion is important in early diagnosis and treatment to prevent chronicity and morbidity in these patients. SSKI is fairly safe and effective when itraconazole is not affordable/ available.

Genetic surfing, not allopatric divergence, explains spatial sorting of mitochondrial haplotypes in venomous coralsnakes.

Science.gov (United States)

Streicher, Jeffrey W; McEntee, Jay P; Drzich, Laura C; Card, Daren C; Schield, Drew R; Smart, Utpal; Parkinson, Christopher L; Jezkova, Tereza; Smith, Eric N; Castoe, Todd A

2016-07-01

Strong spatial sorting of genetic variation in contiguous populations is often explained by local adaptation or secondary contact following allopatric divergence. A third explanation, spatial sorting by stochastic effects of range expansion, has been considered less often though theoretical models suggest it should be widespread, if ephemeral. In a study designed to delimit species within a clade of venomous coralsnakes, we identified an unusual pattern within the Texas coral snake (Micrurus tener): strong spatial sorting of divergent mitochondrial (mtDNA) lineages over a portion of its range, but weak sorting of these lineages elsewhere. We tested three alternative hypotheses to explain this pattern-local adaptation, secondary contact following allopatric divergence, and range expansion. Collectively, near panmixia of nuclear DNA, the signal of range expansion associated sampling drift, expansion origins in the Gulf Coast of Mexico, and species distribution modeling suggest that the spatial sorting of divergent mtDNA lineages within M. tener has resulted from genetic surfing of standing mtDNA variation-not local adaptation or allopatric divergence. Our findings highlight the potential for the stochastic effects of recent range expansion to mislead estimations of population divergence made from mtDNA, which may be exacerbated in systems with low vagility, ancestral mtDNA polymorphism, and male-biased dispersal. © 2016 The Author(s).

Unusual motions of a vibrating string

Science.gov (United States)

Hanson, Roger J.

2003-10-01

The actual motions of a sinusoidally driven vibrating string can be very complex due to nonlinear effects resulting from varying tension and longitudinal motion not included in simple linear theory. Commonly observed effects are: generation of motion perpendicular to the driving force, sudden jumps in amplitude, hysteresis, and generation of higher harmonics. In addition, these effects are profoundly influenced by wire asymmetries which in a brass harpsichord wire can cause a small splitting of each natural frequency of free vibration into two closely spaced frequencies (relative separation ~0.2% to 2%), each associated with transverse motion along two orthogonal characteristic wire axes. Some unusual resulting patterns of complex motions of a point on the wire are exhibited on videotape. Examples include: sudden changes of harmonic content, generation of subharmonics, and motion which appears nearly chaotic but which has a pattern period of over 10 s. Another unusual phenomenon due to entirely different causes can occur when a violin string is bowed with a higher than normal force resulting in sounds ranging from about a musical third to a twelfth lower than the sound produced when the string is plucked.

Unusual complication and successful high-dose chemotherapy ...

African Journals Online (AJOL)

... treated with high-dose chemotherapy in our institution, complicated by unusual bilateral renal vein tumour thrombi and tumour lysis syndrome. We believe this unique case highlights the need for early recognition of current and potential complications on staging computed tomography imaging, as well as successful use of ...

Kinetics of Multielectron Transfers and Redox-Induced Structural Changes in N-Aryl-Expanded Pyridiniums: Establishing Their Unusual, Versatile Electrophoric Activity

Czech Academy of Sciences Publication Activity Database

Lachmanová, Štěpánka; Dupeyre, G.; Tarábek, Ján; Ochsenbein, P.; Perruchot, Ch.; Ciofini, I.; Hromadová, Magdaléna; Pospíšil, Lubomír; Lainé, P. P.

2015-01-01

Roč. 137, č. 35 (2015), s. 11349-11364 ISSN 0002-7863 R&D Projects: GA ČR GA13-19213S; GA ČR(CZ) GA14-05180S; GA MŠk(CZ) 7AMB15FR027 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200401202 Program:M Institutional support: RVO:61388955 ; RVO:61388963 Keywords : multielectron transfer * electrochemistry * kinetics Subject RIV: CG - Electrochemistry Impact factor: 13.038, year: 2015

Unusual headaches in the elderly.

Science.gov (United States)

Bamford, Cynthia C; Mays, MaryAnn; Tepper, Stewart J

2011-08-01

Prevalence of headache lowers with age, and headaches of elderly adults tend to be different than those of the younger population. Secondary headaches, such as headaches associated with vascular disease, head trauma, and neoplasm, are more common. Also, certain headache types tend to be geriatric disorders, such as primary cough headache, hypnic headache, typical aura without headache, exploding head syndrome, and giant cell arteritis. This review provides an overview of some of the major and unusual geriatric headaches, both primary and secondary.

Kinetics of gamma quanta initiated difluoroethane chlorization in inert solvent in dynamic conditions

International Nuclear Information System (INIS)

Begishev, I.R.; Poluehktov, V.A.

1979-01-01

Studied is the kinetics of asymmetric difluoroethane chlorination under dynamic conditions where difluoroethane and chlorine are passed through liquid tetrachloromethane layer. It is shown that initiating chlorination of asymmetric difluoroethane by gamma quanta in the dose and temperature ranges of 2-50 rad/s and -30-100 deg C respectively brings to the significant increase of the reaction rate and unusually high trend for halogenated hydrocarbons, i.e. practically 1, 1, 1 - difluorochloroethane with quantitative yield is formed. In this case radiation chemical yield G=10 4 -10 5 is achieved. It is shown that the chlorination process under dynamic conditions, complicated by the transport of initial reagents from a gas phase to a liquid one and reaction products from a liquid phase to a gas one, is described satisfactorily by the model of ideal substitution reactor

Signatures of mode conversion and kinetic Alfven waves at the magnetopause

International Nuclear Information System (INIS)

Johnson, Jay R.; Cheng, C. Z.

2000-01-01

It has been suggested that resonant mode conversion of compressional MHD waves into kinetic Alfven waves at the magnetopause can explain the abrupt transition in wave polarization from compressional to transverse commonly observed during magnetopause crossings. The authors analyze magnetic field data for magnetopause crossings as a function of magnetic shear angle (defined as the angle between the magnetic fields in the magnetosheath and magnetosphere) and compare with the theory of resonant mode conversion. The data suggest that amplification in the transverse magnetic field component at the magnetopause is not significant up to a threshold magnetic shear angle. Above the threshold angle significant amplification results, but with weak dependence on magnetic shear angle. Waves with higher frequency are less amplified and have a higher threshold angle. These observations are qualitatively consistent with theoretical results obtained from the kinetic-fluid wave equations

Exploring the Invisible Renormalon Renormalization of the Heavy-Quark Kinetic Energy

CERN Document Server

Neubert, M

1997-01-01

Using the virial theorem of the heavy-quark effective theory, we show that the mixing of the operator for the heavy-quark kinetic energy with the identity operator is forbidden at the one-loop order by Lorentz invariance. This explains why such a mixing was not observed in several one-loop calculations using regularization schemes with a Lorentz-invariant UV regulator, and why no UV renormalon singularity was found in the matrix elements of the kinetic operator in the bubble approximation (the ``invisible renormalon''). On the other hand, we show that the mixing is not protected in general by any symmetry, and it indeed occurs at the two-loop order. This implies that the parameter $\\lambda_1^H$ of the heavy-quark effective theory is not directly a physical quantity, but requires a non-perturbative subtraction.

Experience from unusual occurrences in HWP (Tuticorin) (Paper No. 4.8)

International Nuclear Information System (INIS)

Kanthiah, W.S.A.; Vaidyan, P.A.O.; Bhowmick, S.C.

1992-01-01

During the operation of heavy water plants a number of unusual incidents do occur which are hurdles to the smooth operation of the system. An attempt has been made to give a detailed study of a few cases of unusual occurrences such as rupture of ammonia cracker tubes, water entry in cable junction box through nitrogen line, potassium amide splash on maintenance personnel, booster compressor trip explosion in effluent system, etc. in Heavy Water Plant, Tuticorin. (author). 5 figs

Lower extremity kinetics in tap dance.

Science.gov (United States)

Mayers, Lester; Bronner, Shaw; Agraharasamakulam, Sujani; Ojofeitimi, Sheyi

2010-01-01

Tap dance is a unique performing art utilizing the lower extremities as percussion instruments. In a previous study these authors reported decreased injury prevalence among tap dancers compared to other dance and sports participants. No biomechanical analyses of tap dance exist to explain this finding. The purpose of the current pilot study was to provide a preliminary overview of normative peak kinetic and kinematic data, based on the hypothesis that tap dance generates relatively low ground reaction forces and joint forces and moments. Six professional tap dancers performed four common tap dance sequences that produced data captured by the use of a force platform and a five-camera motion analysis system. The mean vertical ground reaction force for all sequences was found to be 2.06+/-0.55 BW. Mean peak sagittal, frontal, and transverse plane joint moments (hip, knee, and ankle) ranged from 0.07 to 2.62 N.m/kg. These small ground reaction forces and joint forces and moments support our hypothesis, and may explain the relatively low injury incidence in tap dancers. Nevertheless, the analysis is highly complex, and other factors remain to be studied and clarified.

Probable Unusual Transmission of Zika Virus

Centers for Disease Control (CDC) Podcasts

2011-05-23

This podcast discusses a study about the probable unusual transmission of Zika Virus Infection from a scientist to his wife, published in the May 2011 issue of Emerging Infectious Diseases. Dr. Brian Foy, Associate Professor at Colorado State University, shares details of this event.  Created: 5/23/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 5/25/2011.

Emphysematous cystitis: An unusual lower urinary tract infection ...

African Journals Online (AJOL)

Emphysematous cystitis: An unusual lower urinary tract infection. MA Lakmichi, M Boukhar, F Barjani, O Saghir, T Hanich, B Wakrim, M Gabsi, A Elhauos, N Charif Idrissi Genouni, N Ousehal, Z Dahami, SM Moudouni, I Sarf ...

An unusual case of the Capgras syndrome.

Science.gov (United States)

Fialkov, M J; Robins, A H

1978-04-01

A variant of the Capgras syndrome is described in a 43-year-old woman who had vitiligo and multinodular goitre. The unusual feature of the case was that the patient not only misidentified members of her own family but also claimed that she herself had been replaced by a double.

Unusual Market Activity Announcements: A Study of Price Manipulation on the Indonesian Stock Exchange

Directory of Open Access Journals (Sweden)

Mamduh M. Hanafi

2010-05-01

Full Text Available We investigate stocks involved in the Unusual Market Activity (UMA Announcements. The Indonesian Stock Exchange occasionally issues UMA announcements when it suspects that there are unusual price increases (positive UMAs or price decreases (negative UMAs, as well as unusual increases in trading volumes. We believe that UMA announcements signal a high probability that stocks are being manipulated. We find no differences in fundamentals and trading variables between stocks in the UMA announcements and those not in the UMA announcements. Any stock is vulnerable to market manipulation. Stocks in the UMA announcements do not exhibit reversal patterns, suggesting that price effect is permanent. UMAs seem to convey relevant information, which is most likely in the form of insider type of information. Keywords: emerging market; price manipulation; unusual market activity announcement.

Kinetic and Thermodynamic Features Reveal That E. coli BCP Is an Unusually Versatile Peroxiredoxin†

Science.gov (United States)

Reeves, Stacy A.; Parsonage, Derek; Nelson, Kimberly J.; Poole, Leslie B.

2011-01-01

In Escherichia coli, bacterioferritin-comigratory protein (BCP) is a peroxiredoxin (Prx) which catalyzes the reduction of H2O2 and organic hydroperoxides. This protein, along with plant PrxQ, is a founding member of one of the least studied subfamilies of Prxs. Recent structural data have suggested that proteins in the BCP/PrxQ group can exist as monomers or dimers; we report here that, by analytical ultracentrifugation, both oxidized and reduced E. coli BCP behave as monomers in solution at concentrations as high as 200 µM. Unexpectedly, thioredoxin (Trx1)-dependent peroxidase assays conducted by stopped flow spectroscopy demonstrated that Vmax,app increases with increasing Trx1 concentrations, indicating a nonsaturable interaction (Km > 100 µM). At a physiologically reasonable Trx1 concentration of 10 µM, the apparent Km value for H2O2 is ~80 µM, and overall Vmax/Km for H2O2, which remains constant over the various Trx1 concentrations (consistent with a ping-pong mechanism), is about 1.3 × 104 M−1 s−1. Our kinetic analyses demonstrated that BCP can utilize a variety of reducing substrates, including Trx1, Trx2, Grx1 and Grx3. BCP exhibited a high redox potential of −145.9 ± 3.2 mV, the highest to date observed for a Prx. Moreover, BCP exhibited a broad peroxide specificity, with comparable rates for H2O2 and cumene hydroperoxide. We determined a pKa of ~5.8 for the peroxidatic cysteine (Cys45) using both spectroscopic and activity titration data. These findings support an important role for BCP in interacting with multiple substrates and remaining active under highly oxidizing cellular conditions, potentially serving as a defense enzyme of last resort. PMID:21910476

Evolution of IPv6 Internet topology with unusual sudden changes

International Nuclear Information System (INIS)

Ai Jun; Su Zhan; Li Hui; Zhao Hai; Carley, Kathleen M.

2013-01-01

The evolution of Internet topology is not always smooth but sometimes with unusual sudden changes. Consequently, identifying patterns of unusual topology evolution is critical for Internet topology modeling and simulation. We analyze IPv6 Internet topology evolution in IP-level graph to demonstrate how it changes in uncommon ways to restructure the Internet. After evaluating the changes of average degree, average path length, and some other metrics over time, we find that in the case of a large-scale growing the Internet becomes more robust; whereas in a top—bottom connection enhancement the Internet maintains its efficiency with links largely decreased

Evolution of IPv6 Internet topology with unusual sudden changes

Science.gov (United States)

Ai, Jun; Zhao, Hai; Kathleen, M. Carley; Su, Zhan; Li, Hui

2013-07-01

The evolution of Internet topology is not always smooth but sometimes with unusual sudden changes. Consequently, identifying patterns of unusual topology evolution is critical for Internet topology modeling and simulation. We analyze IPv6 Internet topology evolution in IP-level graph to demonstrate how it changes in uncommon ways to restructure the Internet. After evaluating the changes of average degree, average path length, and some other metrics over time, we find that in the case of a large-scale growing the Internet becomes more robust; whereas in a top—bottom connection enhancement the Internet maintains its efficiency with links largely decreased.

Kinetic energies of charged fragments resulting from multifragmentation and asymmetric fission of the C60 molecule in collisions with monocharged ions (2-130 keV)

International Nuclear Information System (INIS)

Rentenier, A; Bordenave-Montesquieu, D; Moretto-Capelle, P; Bordenave-Montesquieu, A

2003-01-01

Multifragmentation and asymmetric fission (AF) of the C 60 molecule induced by H + , H 2 + , H 3 + and He + ions at medium collision energies (2-130 keV) are considered. Momenta and kinetic energies of C n + fragment ions (n = 1- 12) are deduced from an analysis of time-of-flight spectra. In multifragmentation processes, momenta are found to be approximately constant when n > 2, a behaviour which explains that the most probable kinetic energy, as well as the width of the kinetic energy distributions, is found to be inversely proportional to the fragment size n; both momenta and kinetic energies are independent of the velocity and nature of the projectile, and hence of the energy deposit. A specific study of the AF shows that the kinetic energies of C 2 + , C 4 + and C 6 + fragments are also independent of the collision velocity and projectile species; a quantitative agreement is found with values deduced from kinetic energy release measurements by another group in electron impact experiments, and the observed decrease when the mass of the light fragment increases is also reproduced. A quantitative comparison of AF and multifragmentation for the n = 2, 4 and 6 fragment ions shows that kinetic energies in AF exceed that in multifragmentation, a result which explains the oscillations observed when momenta or kinetic energies of fragments are plotted against the n-value. The AF yield is also found to scale with the energy deposit in the collision velocity range extending below the velocity at the maximum of the electronic stopping power; except for protons, it remains negligible with respect to multifragmentation as soon as the total energy deposit exceeds about 100 eV

Explaining away the body: experiences of supernaturally caused touch and touch on non-hand objects within the rubber hand illusion.

Directory of Open Access Journals (Sweden)

Jakob Hohwy

2010-02-01

Full Text Available In rubber hand illusions and full body illusions, touch sensations are projected to non-body objects such as rubber hands, dolls or virtual bodies. The robustness, limits and further perceptual consequences of such illusions are not yet fully explored or understood. A number of experiments are reported that test the limits of a variant of the rubber hand illusion.A variant of the rubber hand illusion is explored, in which the real and foreign hands are aligned in personal space. The presence of the illusion is ascertained with participants' scores and temperature changes of the real arm. This generates a basic illusion of touch projected to a foreign arm. Participants are presented with further, unusual visuotactile stimuli subsequent to onset of the basic illusion. Such further visuotactile stimulation is found to generate very unusual experiences of supernatural touch and touch on a non-hand object. The finding of touch on a non-hand object conflicts with prior findings, and to resolve this conflict a further hypothesis is successfully tested: that without prior onset of the basic illusion this unusual experience does not occur.A rubber hand illusion is found that can arise when the real and the foreign arm are aligned in personal space. This illusion persists through periods of no tactile stimulation and is strong enough to allow very unusual experiences of touch felt on a cardboard box and experiences of touch produced at a distance, as if by supernatural causation. These findings suggest that one's visual body image is explained away during experience of the illusion and they may be of further importance to understanding the role of experience in delusion formation. The findings of touch on non-hand objects may help reconcile conflicting results in this area of research. In addition, new evidence is provided that relates to the recently discovered psychologically induced temperature changes that occur during the illusion.

Disordering kinetics in surface overlayers

International Nuclear Information System (INIS)

Jesina, A.; Tringides, M.C.

1993-01-01

The disordering kinetics of the O/W(110)-p(2x1)+p(2x2) overlayer, prepared initially in a well-ordered state, are studied with low-energy electron diffraction profile analysis. The decay of the peak intensity, used as a measure of the growing disorder, cannot be fitted to a power law as in the case of ordering processes. The full width at half maximum of the time-dependent structure factor S(q,t) is constant with time, which suggests that the average size remains constant. Diffusion activation energy extracted for the temperature dependence of the disordering is 1.0±0.05 eV, which is different from the value of 0.6 eV measured in ordering processes. The difference can be explained by the adsorbate-adsorbate interactions, which contribute differently to the diffusion barrier, in the two experiments

Effect of ultrasound on flotation kinetics in the reactor-separator

International Nuclear Information System (INIS)

Filippov, L O; Matinin, A S; Samiguin, V D; Filippova, I V

2013-01-01

Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

Effect of ultrasound on flotation kinetics in the reactor-separator

Science.gov (United States)

Filippov, L. O.; Matinin, A. S.; Samiguin, V. D.; Filippova, I. V.

2013-03-01

Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

Quantum tunneling observed without its characteristic large kinetic isotope effects.

Science.gov (United States)

Hama, Tetsuya; Ueta, Hirokazu; Kouchi, Akira; Watanabe, Naoki

2015-06-16

Classical transition-state theory is fundamental to describing chemical kinetics; however, quantum tunneling is also important in explaining the unexpectedly large reaction efficiencies observed in many chemical systems. Tunneling is often indicated by anomalously large kinetic isotope effects (KIEs), because a particle's ability to tunnel decreases significantly with its increasing mass. Here we experimentally demonstrate that cold hydrogen (H) and deuterium (D) atoms can add to solid benzene by tunneling; however, the observed H/D KIE was very small (1-1.5) despite the large intrinsic H/D KIE of tunneling (≳ 100). This strong reduction is due to the chemical kinetics being controlled not by tunneling but by the surface diffusion of the H/D atoms, a process not greatly affected by the isotope type. Because tunneling need not be accompanied by a large KIE in surface and interfacial chemical systems, it might be overlooked in other systems such as aerosols or enzymes. Our results suggest that surface tunneling reactions on interstellar dust may contribute to the deuteration of interstellar aromatic and aliphatic hydrocarbons, which could represent a major source of the deuterium enrichment observed in carbonaceous meteorites and interplanetary dust particles. These findings could improve our understanding of interstellar physicochemical processes, including those during the formation of the solar system.

Dysphagia as an unusual complication of pleural mesothelioma

International Nuclear Information System (INIS)

Khan, S.; But, N.; Bajwa, F.

2008-01-01

Dysphagia is an unusual presentation of pleural mesothelioma and carries a grim prognosis. A case of an elderly patient is presented herein, in whom the diagnosis was confirmed histologically, and the patient was still surviving 6 months after palliation. (author)

Cognitive control and unusual decisions about beauty: An fMRI study

Directory of Open Access Journals (Sweden)

Albert eFlexas

2014-07-01

Full Text Available Studies of visual aesthetic preference have shown that people without art training generally prefer representational paintings to abstract paintings. This, however, is not always the case: preferences can sometimes go against this usual tendency. We aimed to explore this issue, investigating the relationship between ‘unusual responses’ and reaction time in an aesthetic appreciation task. Results of a behavioural experiment confirmed the trend for laypeople to consider as beautiful mostly representational stimuli and as not beautiful mostly abstract ones (‘usual response’. Furthermore, when participants gave unusual responses, they needed longer time, especially when considering abstract stimuli as beautiful. We interpreted this longer time as greater involvement of the cognitive mastering and evaluation stages during the unusual responses. Results of an fMRI experiment indicated that the anterior cingulate, orbitofrontal cortex and insula were the main structures involved in this effect. We discuss the possible role of these areas in an aesthetic appreciation task.

Unusual occurrences during LMFR operation. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

2000-10-01

Design of liquid metal cooled fast reactors (LMFRs) is still in evolution, and only a small number of LMFRs are in operation around the world. Specialists operating these LMFRs have gained valuable experience from incidents, failures, and other events that took place in the reactors. These unusual occurrences, lessons learned and measures undertaken to prevent recurrences are often either not reported in the literature, or reported only briefly and without sufficient detail. Hence there is a need for specialists designing and operating LMFRs to share their knowledge on unusual occurrences. Considerable experimental and theoretical knowledge in this field were collected by several Member states over the past decades. The needs in generalisation, review and documentation of fundamental knowledge in liquid metal cooled reactor technology were a major consideration in the recommendation by the International Working group on fast reactors for the IAEA to convene this Technical Committee meeting on the subject of unusual occurrences during LMFR operation and the consequences for reactor systems

Stochastic theory of interfacial enzyme kinetics: A kinetic Monte Carlo study

International Nuclear Information System (INIS)

Das, Biswajit; Gangopadhyay, Gautam

2012-01-01

Graphical abstract: Stochastic theory of interfacial enzyme kinetics is formulated. Numerical results of macroscopic phenomenon of lag-burst kinetics is obtained by using a kinetic Monte Carlo approach to single enzyme activity. Highlights: ► An enzyme is attached with the fluid state phospholipid molecules on the Langmuir monolayer. ► Through the diffusion, the enzyme molecule reaches the gel–fluid interface. ► After hydrolysing a phospholipid molecule it predominantly leaves the surface in the lag phase. ► The enzyme is strictly attached to the surface with scooting mode of motion and the burst phase appears. - Abstract: In the spirit of Gillespie’s stochastic approach we have formulated a theory to explore the advancement of the interfacial enzyme kinetics at the single enzyme level which is ultimately utilized to obtain the ensemble average macroscopic feature, lag-burst kinetics. We have provided a theory of the transition from the lag phase to the burst phase kinetics by considering the gradual development of electrostatic interaction among the positively charged enzyme and negatively charged product molecules deposited on the phospholipid surface. It is shown that the different diffusion time scales of the enzyme over the fluid and product regions are responsible for the memory effect in the correlation of successive turnover events of the hopping mode in the single trajectory analysis which again is reflected on the non-Gaussian distribution of turnover times on the macroscopic kinetics in the lag phase unlike the burst phase kinetics.

Unusual strain in homoepitaxial CdTe(001) layers grown by molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Heinke, H.; Waag, A.; Moeller, M.O.; Regnet, M.M.; Landwehr, G. [Physikalisches Institut, Univ. Wuerzburg (Germany)

1994-01-01

For homoepitaxial CdTe(001) films grown by molecular beam epitaxy onto CdTe(001) substrates, a difference between the lattice constants of the substrate and the layer was systematically observed using high resolution X-ray diffraction. Reciprocal space maps point out an unusual strain state of such layers which is indicated by the position of their reciprocal lattice points. They lie in a section of reciprocal space which is usually forbidden by elasticity theory. The strain is laterally anisotropic leading to a monoclinic symmetry of the thin films. The lateral strain is depth dependent. Possible reasons for the formation of the unusual strain are discussed, and a correlation of the unusual strain with the growth conditions is attempted

Understanding Yield Anomalies in ICF Implosions via Fully Kinetic Simulations

Science.gov (United States)

Taitano, William

2017-10-01

In the quest towards ICF ignition, plasma kinetic effects are among prime candidates for explaining some significant discrepancies between experimental observations and rad-hydro simulations. To assess their importance, high-fidelity fully kinetic simulations of ICF capsule implosions are needed. Owing to the extremely multi-scale nature of the problem, kinetic codes have to overcome nontrivial numerical and algorithmic challenges, and very few options are currently available. Here, we present resolutions of some long-standing yield discrepancy conundrums using a novel, LANL-developed, 1D-2V Vlasov-Fokker-Planck code iFP. iFP possesses an unprecedented fidelity and features fully implicit time-stepping, exact mass, momentum, and energy conservation, and optimal grid adaptation in phase space, all of which are critically important for ensuring long-time numerical accuracy of the implosion simulations. Specifically, we concentrate on several anomalous yield degradation instances observed in Omega campaigns, with the so-called ``Rygg effect'', or an anomalous yield scaling with the fuel composition, being a prime example. Understanding the physical mechanisms responsible for such degradations in non-ignition-grade Omega experiments is of great interest, as such experiments are often used for platform and diagnostic development, which are then used in ignition-grade experiments on NIF. In the case of Rygg's experiments, effects of a kinetic stratification of fuel ions on the yield have been previously proposed as the anomaly explanation, studied with a kinetic code FPION, and found unimportant. We have revisited this issue with iFP and obtained excellent yield-over-clean agreement with the original Rygg results, and several subsequent experiments. This validates iFP and confirms that the kinetic fuel stratification is indeed at the root of the observed yield degradation. This work was sponsored by the Metropolis Postdoctoral Fellowship, LDRD office, Thermonuclear Burn

'Unusual' MRI appearance of sphenoid sinus mucocele

International Nuclear Information System (INIS)

Ruelle, A.; Pisani, R.; Andrioli, G.

1991-01-01

The authors report a case of sphenoid sinus mucocele which exhibited unusual MRI features. However a review of the literature shows that these lesions may present with different MRI appearances probably related to the variability of the cyst content. Further series are needed for a better definition of the MRI behaviour of the lesions. (orig.)

Physical kinetics

International Nuclear Information System (INIS)

Lifschitz, E.M.; Pitajewski, L.P.

1983-01-01

The textbook covers the subject under the following headings: kinetic gas theory, diffusion approximation, collisionless plasma, collisions within the plasma, plasma in the magnetic field, theory of instabilities, dielectrics, quantum fluids, metals, diagram technique for nonequilibrium systems, superconductors, and kinetics of phase transformations

Dissolution kinetics of lead telluride in alkali solutions of hydrogen peroxide

International Nuclear Information System (INIS)

Danilova, M.G.; Sveshnikova, L.L.; Stavitskaya, T.A.; Repinskij, S.M.

1991-01-01

Dissolution kinetics of lead telluride in alkali solutions of hydrogen peroxide was investigated. Dependences of change of PbTe dissolution rate on concentration of hydrogen peroxide and alkali in the solution were obtained. It is shown that dissolution rate of lead telluride is affected by dissolution rate of lead oxide, representing the product of ReTe dissolution. The obtained regularities can be explained by change of solution structure with increase of KOH concentration and by the state of hydrogen peroxide in the solution

Unusual osteopathy in a newborn

Energy Technology Data Exchange (ETDEWEB)

Jequier, S.; Nogrady, M.B.; Wesenberg, R.L.

1983-06-01

A newborn baby presented with hyaline membrane disease, interstitial pneumonia, jaundice, hepatosplenomegaly, and unusual bone manifestations with lytic and sclerotic bone lesions and virtually absent periosteal reaction. He subsequently developed intracranial calcifications and mental retardation. The pneumonia and hepatosplenomegaly resolved. At the time of the delivery, a sibling was suffering from a severe undetermined viral infection. The clinical evolution of the disease and the radiologic findings led us to believe that this patient has a prenatal viral infection. The laboratory tests and the histologic picture of the bone biopsy supported the diagnosis.

Unusual osteopathy in a newborn

International Nuclear Information System (INIS)

Jequier, S.; Nogrady, M.B.; Wesenberg, R.L.

1983-01-01

A newborn baby presented with hyaline membrane disease, interstitial pneumonia, jaundice, hepatosplenomegaly, and unusual bone manifestations with lytic and sclerotic bone lesions and virtually absent periosteal reaction. He subsequently developed intracranial calcifications and mental retardation. The pneumonia and hepatosplenomegaly resolved. At the time of the delivery, a sibling was suffering from a severe undetermined viral infection. The clinical evolution of the disease and the radiologic findings led us to believe that this patient has a prenatal viral infection. The laboratory tests and the histologic picture of the bone biopsy supported the diagnosis. (orig.)

Unusual CT image of a cerebral hydatid cyst

International Nuclear Information System (INIS)

Gonzalez-Ruiz, C.A.; Isla, A.; Blazquez, M.G.; Perez-Higueras, A.

1990-01-01

We report an unusual case of cerebral hydatid cyst which was found with CT. Unenhanced CT showed a hyperdense, not calcified, ring surrounding the cyst cavity. This has never been reported before. We propose a possible explanation for such abnormal behaviour. (orig.)

Myopericytoma proliferating in an unusual anastomosing multinodular fashion.

Science.gov (United States)

Inoue, Takuya; Misago, Noriyuki; Asami, Akihiko; Tokunaga, Osamu; Narisawa, Yutaka

2016-05-01

We herein describe a case of myopericytoma that proliferated in an unusual fashion. Myopericytoma is described as a group of rare, benign, dermal or subcutaneous tumors that are characterized histologically by a striking, concentric, perivascular proliferation of spindle cells and showing apparent differentiation towards perivascular myoid cells. Myopericytoma forms a morphological continuum with myofibroma/myofibromatosis, glomus tumor and angioleiomyoma. The patient was a 64-year-old woman who demonstrated a recurrent ulcer on an atrophic plaque on her left shin. A histopathological examination of the plaque demonstrated that tumor cells proliferated in an anastomosing multinodular fashion along the vessels in the dermis and subcutaneous tissue. In those nodules, there were numerous, small, concentric proliferations of myoid-appearing spindle cells around small vascular lumina. The present case is an unusual example of myopericytoma, manifesting in a characteristic anastomosing, multinodular, infiltrating fashion. © 2015 Japanese Dermatological Association.

Synchrotron Study on Crystallization Kinetics of Milk Fat under Shear Flow

International Nuclear Information System (INIS)

Mazzanti, G.; Marangoni, A.; Idziak, S.

2009-01-01

A detailed synchrotron X-ray diffraction study on the kinetics of crystallization of anhydrous milk fat (AMF) and milk fat triacylglycerols (MFT) was done in a Couette cell at 17 C, 17.5 C and 20 C under shear rates between 0 and 2880 s-1. We observed shear-induced acceleration of the transition from phase ? to ?? and the presence of crystalline orientation, but no effect of shear on the onset time of phase ? was observed. A two stage regime was observed for the growth of phase ??. The first stage follows a series-parallel system of differential equations describing the conversion between liquid and crystalline phases. The second stage follows a diffusion-controlled regime. These mechanisms are consistent with the crystalline orientation, the growth of the crystalline domains and the observed displacement of the diffraction peak positions. The absence of the polar lipids explains the faster kinetics of MFT.

Searches with long-lived or unusual signatures

CERN Document Server

Haug, S; The ATLAS collaboration

2013-01-01

We present recent ATLAS and CMS results from searches with long-lived and unusual signatures. They are based on analysis of LHC proton-proton collisions at center of mass energies at 7 and 8 TeV. Long-lived and heavy particles may cause peculiar signatures in the detectors, but are in several Standard Model extensions well motivated.

Kinetic energy of ions produced with first-, second-, and multi-shot femtosecond laser ablation on a solid surface

International Nuclear Information System (INIS)

Kobayashi, Tohru; Kato, Toshiyuki; Kurata-Nishimura, Mizuki; Matsuo, Yukari; Kawai, Jun; Motobayashi, Tohru; Hayashizaki, Yoshihide

2007-01-01

We report that the kinetic energy of samarium (Sm) atom and Sm + ion produced by femtosecond laser ablation of solid samarium is strongly dependent on the number of ablation laser shots in the range from 1 to 10. By ablating the fresh surface (i.e. 1st shot), we find the kinetic energy of both Sm and Sm + ion to be the largest (24 and 250 eV, respectively). Almost 10 times larger kinetic energy of Sm + ion than that of Sm clearly indicates the contribution of Coulomb explosion in the acceleration process. From the second shot, kinetic energies of Sm and Sm + ion are lower than those of the first shot and almost constant (ca. 12 and 80 eV, respectively). This behaviour suggests the change in the nature of the solid surface after femtosecond laser ablation, which can be explained by the amorphization of ablated sample surface reported in recent studies

An Unusual Cause of Rectal Stenosis

Directory of Open Access Journals (Sweden)

Maja Gruber

2016-08-01

Full Text Available Solitary rectal ulcer syndrome (SRUS is a benign disease that is often misdiagnosed. It is characterized by a combination of symptoms, endoscopic findings and histology. Patients present with constipation, rectal bleeding, mucous discharge, pain and a sensation of incomplete defecation. There are many different manifestations of this disease, with or without rectal prolapse. We report an unusual presentation of SRUS as a circular stenosis in a middle-aged male.

Unusual presentation of extrapulmonary tuberculosis: a case report ...

African Journals Online (AJOL)

This case study highlights an unusual manifestation of extrapulmonary tuberculosis (TB) in a person living with HIV, namely mammary TB. Clinicians practising in settings where HIV and TB are endemic need to be aware of the clinical presentation, diagnosis and management of mammary TB.

Investigation of effect of air flow rate on Zircaloy-4 oxidation kinetics and breakaway phenomenon in air at 850 .deg. C

International Nuclear Information System (INIS)

Maeng, Yunhwan; Lee, Jaeyoung; Park, Sanggil

2016-01-01

This paper analyzed an effect of flow rate on oxidation kinetics of Zircaloy-4 in air at 850 .deg. C. In case of the oxidation of Zircaloy-4 in air at 850 .deg. C, acceleration of oxidation kinetics from parabolic to linear (breakaway phenomenon) occurs. Oxidation and breakaway kinetics of the Zircaloy-4 in air was experimentally studied by changing a flow rate of argon/air mixture. Tests were conducted at 850 .deg. C under constant ratio of argon and air. The effects of flow rate on the oxidation and breakaway kinetics was observed. This paper is based on a revised and considerably extended presentation given at the 21 st International Quench Workshop. The effects of flow conditions on the oxidation kinetics of Zircaloy-4 samples were explained with residence time and percent flow efficiency. In addition, several issues were observed from this study, interdiffusion at breakaway and deformation of oxide structure by breakaway phenomenon

Real-time kinetic modeling of YSZ thin film roughness deposited by e-beam evaporation technique

International Nuclear Information System (INIS)

Galdikas, A.; Cerapaite-Trusinskiene, R.; Laukaitis, G.; Dudonis, J.

2008-01-01

In the present study, the process of yttrium-stabilized zirconia (YSZ) thin films deposition on optical quartz (SiO 2 ) substrates using e-beam deposition technique controlling electron gun power is analyzed. It was found that electron gun power influences the non-monotonous kinetics of YSZ film surface roughness. The evolution of YSZ thin film surface roughness was analyzed by a kinetic model. The model is based on the rate equations and includes processes of surface diffusion of the adatoms and the clusters, nucleation, growth and coalescence of islands in the case of thin film growth in Volmer-Weber mode. The analysis of the experimental results done by modeling explains non-monotonous kinetics and dependence of the surface roughness on the electron gun power. A good quantitative agreement with experimental results is obtained taking into account the initial roughness of the substrate surface and the amount of the clusters in the flux of evaporated material.

Drug Resistance and the Kinetics of Metastatic Cancer

Science.gov (United States)

Blagoev, Krastan B.

2012-02-01

Most metastatic cancers after initial response to current drug therapies develop resistance to the treatment. We present cancer data and a theory that explains the observed kinetics of tumor growth in cancer patients and using a stochastic model based on this theory we relate the kinetics of tumor growth to Kaplan-Meyer survival curves. The theory points to the tumor growth rate as the most important parameter determining the outcome of a drug treatment. The overall tumor growth or decay rate is a reflection of the balance between cell division, senescence and apoptosis and we propose that the deviation of the decay rate from exponential is a measure of the emergence of drug resistance. In clinical trials the progression free survival, the overall survival, and the shape of the Kaplan-Meyer plots are determined by the tumor growth rate probability distribution among the patients in the trial. How drug treatments modify this distribution will also be described. At the end of the talk we will discuss the connection between the theory described here and the age related cancer mortality rates in the United States.

Planktivorous auklet Ptychoramphus aleuticus responses to ocean climate, 2005: Unusual atmospheric blocking?

Science.gov (United States)

Sydeman, William J.; Bradley, Russell W.; Warzybok, Pete; Abraham, Christine L.; Jahncke, Jaime; Hyrenbach, K. David; Kousky, Vernon; Hipfner, J. Mark; Ohman, Mark D.

2006-10-01

In spring-summer 2005, anomalous atmospheric-oceanographic coupling caused unprecedented reproductive failures and redistribution of a planktivorous marine bird in both central California (37°N) and southern British Columbia (50°N). At SE Farallon Island, CA, the birds abandoned the breeding colony en masse between 10-20 May, a unique behavioral response; for the first time in 35 years, reproductive success was zero. At Triangle Island, B.C., only 8% of the nesting pairs were successful, the worst year on record. Surveys of birds at sea revealed a peak in relative abundance south of Point Conception (34°N) in summer and fall, suggestive of emigration from the north. Prey (euphausiid crustacean) biomass in the Gulf of the Farallones was reduced, but remained high south of Point Conception. Change in predator and prey may be explained, in part, by unusual atmospheric blocking in the Gulf of Alaska in May, which caused the jet stream to shift southwards resulting in poor upwelling-favorable winds and anomalously warm SST. This study demonstrates the deleterious consequences of this climate event for a top marine predator in the central-northern California Current System.

An Unusual Presentation of Myasthenia Gravis | Chijioke | West ...

African Journals Online (AJOL)

BACK GROUND: Myasthenia gravis (MG) is generally a rare disorder and may thus be easily misdiagnosed. Misdiagnosis is even more likely when the presentation is atypical. OBJECTIVE: To present and discuss an unusual presentation of myasthenia gravis METHOD: A 67-year-old man presented with progressive ...

Hypothetical views on some unusual disease associations with ...

African Journals Online (AJOL)

Sickle cell anemia (SCA) is a disease accompanied with several complications arising mainly from vasoocclusion and haemolysis. There are also complications of infections which may occur due to defective cell mediated and humoral immunity. However, there are associations that have been observed to be unusual in ...

An unusual nonlinear system in the magnetosphere: A possible driver for auroral pulsations

International Nuclear Information System (INIS)

Davidson, G.T.; Chiu, Y.T.

1991-01-01

Many aspects of the relation between spatial and temporal structures in morningside aurorae can be explained with the aid of a nonlinear model that describes the interactions between energetic electrons and VLF waves. The simplest form of the model consists of three differential equations, with time derivatives generated in reference frames moving with either the energetic electrons, the cold plasma; or the VLF waves that interact with the energetic electrons. Although unstable solutions that could explain the origin of spatial structures are not found, the existence of spatial structures having sufficiently fine scales can provide a repetitive perturbation that maintains the temporal variations. An analysis of the behavior of solutions of the nonlinear system reveals that a strange attractor does not occur in the autonomous system; but when the repetitive perturbations are regarded as external periodic forcing terms, unusual forms of nonlinear behavior are revealed. If the frequencies of the forcing terms are not commensurate with the natural periods of the system, the solutions present some of the characteristics of deterministic chaos. The nearest analogy is a driven nonlinear oscillator with asymmetric damping. However, because of the stiffness of the system, even those solutions that are not truly chaotic (in the commonly accepted usage) will be indistinguishable from chaos over tens to hundreds of pulsation cycles. In certain cases, when damping terms are reduced to zero, the system displays a form of behavior with many of the important characteristics of chaos, but the phase trajectories do not appear to be bounded

Kinetics of growth of nanowhiskers (nanowires and nanotubes

Directory of Open Access Journals (Sweden)

Avramov Isak

2007-01-01

Full Text Available AbstractThe kinetics of nanowhiskers growth is studied theoretically taking into account the adatom diffusion from the surface to the top of needle. An exponential growth with time is expected for the initial stages of the process, when the lengthlof the whisker is smaller than the average diffusion length λ of adatoms. It transforms to linear growth rate forl > λ. The formation of nanotubes with a hollow core dislocation is explained by accounting for the role of the stress in the middle of screw dislocations. When the magnitude of the Burgers vector exceeds a critical value, it is energetically more favorable to remove the highly strained material around the dislocation line and to create a tube with an additional free surface. Additionally, there is an important size effect, due to the small radiusRof the nanowhisker. The interplay, between the contributions from the size effects and from the diffusion, explains why for the very thin nanowhiskers the lengthlis proportional to the radiusRwhile, otherwise the length is inversely proportional to it, i.e.,l∼1/R.

Unusual events in the use of radioactive material at medical applications

International Nuclear Information System (INIS)

Czarwinski, R.

2002-01-01

In the Federal Republic of Germany unusual events in the use of radioactive materials and in the operation of accelerators outside the nuclear sector are evaluated centrally and published annually. At that evaluation it can be distinguished between the medical and non-medical application of ionising radiation. Around 3000 user of radioactive materials are registered in medicine including research and teaching. That means approximately 25% of all users in Germany. Firstly an overview on the number of unusual events in the last ten years is given for medical applications like afterloading, gamma irradiation, nuclear medicine, radiation sources and accelerators. The analysis of the incidents in the considered medical areas resulted in two categories-human error and technical break down. The main causes for the incidents which could be analysed are presented in the paper. Additionally the radiation exposures resulting from the incidents are considered. The analysis of these unusual events enables in dependence of the known information lessons learned to avoid similar errors. This feedback will be offered. (Author)

An Unusual Case Report of Erupted Odontoma

Directory of Open Access Journals (Sweden)

Dhaval Mehta

2013-01-01

Full Text Available Odontomas are the most common of the odontogenic tumors of the jaws, which are benign, slow growing, and nonaggressive. They are usually asymptomatic and found in routine dental radiographic examination. Odontomas are usually associated with tooth eruption disturbances. Eruption of odontoma in oral cavity is rare entity. Here we report a case of an unusual erupted compound odontoma.

Kinetics of phase transformations

International Nuclear Information System (INIS)

Thompson, M.O.; Aziz, M.J.; Stephenson, G.B.

1992-01-01

This volume contains papers presented at the Materials Research Society symposium on Kinetics of Phase Transformations held in Boston, Massachusetts from November 26-29, 1990. The symposium provided a forum for research results in an exceptionally broad and interdisciplinary field. Presentations covered nearly every major class of transformations including solid-solid, liquid-solid, transport phenomena and kinetics modeling. Papers involving amorphous Si, a dominant topic at the symposium, are collected in the first section followed by sections on four major areas of transformation kinetics. The symposium opened with joint sessions on ion and electron beam induced transformations in conjunction with the Surface Chemistry and Beam-Solid Interactions: symposium. Subsequent sessions focused on the areas of ordering and nonlinear diffusion kinetics, solid state reactions and amorphization, kinetics and defects of amorphous silicon, and kinetics of melting and solidification. Seven internationally recognized invited speakers reviewed many of the important problems and recent results in these areas, including defects in amorphous Si, crystal to glass transformations, ordering kinetics, solid-state amorphization, computer modeling, and liquid/solid transformations

Unusual variant of Cantrell′s pentalogy?

Directory of Open Access Journals (Sweden)

Kumar Basant

2008-01-01

Full Text Available A 12-hour-old male infant presented with prolapsed abdominal content through a defect on left side of chest wall with respiratory distress. A thorough clinical examination suggested absence of ectopia cordis, abdominal wall defect, and any bony anomaly. The child expired after 6 hours of admission because of respiratory distress and electrolyte imbalance. Is congenital defect of chest wall associated with diaphragmatic hernia without ectopia cordis and omphalocele, an unusual variant of Cantrell′s pentalogy?

Unusual intramuscular lipoma of deltoid muscle.

Science.gov (United States)

Kapetanakis, Stylianos; Papathanasiou, Jiannis; Dermon, Antonios; Dimitrakopoulou, Alexandra; Ververidis, Athanasios; Chloropoulou, Pelagia; Kazakos, Konstantinos

2010-01-01

Lipomas are common soft tissue tumors usually located under the skin. Nevertheless, intramuscular lipomas of deltoid muscle are unusual tumors. We present a case of 74-year-old woman with an intramuscular like clepsydra lipoma of deltoid muscle. The lesion was a palpable soft mass at the lateral side of the humerus. The patient had no previous history of trauma. The main symptom was pain only in abduction and extension. Imaging, pathological findings and surgical excision are discussed.

Wasp sting: An unusual fatal outcome

International Nuclear Information System (INIS)

George, P.; Mathew, P.; Pawar, B.; Calton, N.

2008-01-01

Wasp stings are not uncommon especially in populations living in theproximity of forested area-s all over the world. Local manifestationsfollowing stings are common and unusually life threatening anaphylaxis mayoccur, requiring prompt treatment. Multi organ failure and acute renalfailure following wasp stings are rare and histological evaluation suggestacute tubular necrosis secondary to hemolysis, rhabdomyolysis and directvenom toxicity. A rare complication of a patient following multiple waspstings with disseminated intravascular coagulation, acute renal failure andthrombotic microangiopathy is presented. (author)

Radiographic evaluation and unusual bone formations in different genetic patterns in synpolydactyly

International Nuclear Information System (INIS)

Yucel, Aylin; Acar, Murat; Kuru, Ilhami; Bozan, M. Eray; Solak, Mustafa

2005-01-01

To compare the radiological findings of heterozygous and homozygous subjects with synpolydactyly (SPD) and to discuss their unusual bone formations. Families with hand and foot SPD were examined. Genetic analysis was performed with blood samples and the pedigree was constructed. The affected individuals, especially those with distinctive phenotypic features, were invited to our orthopaedics clinic for further diagnostic studies. All participants underwent detailed clinical and X-ray examinations. Of the invited patients, 16 (five female and 11 male; age range 4-37 years, mean age 10.75 years) were included in our study, and hand and foot radiographs were obtained. All subjects had bilateral hand radiographs (32 hands), and 14 had bilateral foot radiographs (28 feet). Genetic analysis revealed 12 heterozygote (75%) and four (25%) homozygote phenotypes. Among patients enrolled into the study nine (three homozygotes, six heterozygotes) had SPD of both hands and feet bilaterally (tetrasynpolydactyly). Six unusual bone formations were observed in the hands and feet: delta phalanx, delta metacarpal/metatarsal, kissing delta phalanx, true double epiphysis, pseudoepiphysis and cone-shaped epiphysis. There were major differences in radiological and clinical manifestations of homozygote and heterozygote phenotypes. The homozygous SPD presented with very distinctive unusual bone formations. The existence and variety of unusual bones may indicate the severity of penetrance and expressivity of SPD. (orig.)

Forecasting the student–professor matches that result in unusually effective teaching

Science.gov (United States)

Gross, Jennifer; Lakey, Brian; Lucas, Jessica L; LaCross, Ryan; R Plotkowski, Andrea; Winegard, Bo

2015-01-01

Background Two important influences on students' evaluations of teaching are relationship and professor effects. Relationship effects reflect unique matches between students and professors such that some professors are unusually effective for some students, but not for others. Professor effects reflect inter-rater agreement that some professors are more effective than others, on average across students. Aims We attempted to forecast students' evaluations of live lectures from brief, video-recorded teaching trailers. Sample Participants were 145 college students (74% female) enrolled in introductory psychology courses at a public university in the Great Lakes region of the United States. Methods Students viewed trailers early in the semester and attended live lectures months later. Because subgroups of students viewed the same professors, statistical analyses could isolate professor and relationship effects. Results Evaluations were influenced strongly by relationship and professor effects, and students' evaluations of live lectures could be forecasted from students' evaluations of teaching trailers. That is, we could forecast the individual students who would respond unusually well to a specific professor (relationship effects). We could also forecast which professors elicited better evaluations in live lectures, on average across students (professor effects). Professors who elicited unusually good evaluations in some students also elicited better memory for lectures in those students. Conclusions It appears possible to forecast relationship and professor effects on teaching evaluations by presenting brief teaching trailers to students. Thus, it might be possible to develop online recommender systems to help match students and professors so that unusually effective teaching emerges. PMID:24953773

Glycerol acetals, kinetic study of the reaction between glycerol and formaldehyde

International Nuclear Information System (INIS)

Agirre, I.; Garcia, I.; Requies, J.; Barrio, V.L.; Gueemez, M.B.; Cambra, J.F.; Arias, P.L.

2011-01-01

The acetalization reaction between glycerol and formaldehyde using Amberlyst 47 acidic ion exchange resin was studied. These acetals can be obtained from renewable sources (bioalcohols and bioalcohol derived aldehydes) and seem to be good candidates for different applications such as oxygenated diesel additives. A preliminary kinetic study was performed in a batch stirred tank reactor studying the influence of different process parameters like temperature, feed composition and the stirring speed. A pseudo homogenous kinetic model able to explain the reaction mechanism was adjusted. Thus, the corresponding order of reaction was determined. Amberlyst 47 acidic ion exchange resin showed a fairly good behavior allowing 100% of selectivity towards acetals formation. However, the studied acetalization reaction showed high thermodynamic limitations achieving glycerol conversions around 50% using a stoichiometric feed ratio at 353 K. The product is a mixture of two isomers (1,3-Dioxan-5-ol and 1,3-dioxolane-4-methanol) and the conversion of 1,3-dioxolane-4-methanol into 1,3-Dioxan-5-ol was also observed. -- Highlights: → The reaction between glycerol and acetaldehyde shows thermodynamic limitations. → Amberlyst 47 ion exchange resins show 100% of selectivity. → A pseudo-homogeneous kinetic model is able to predict the reaction progress. → Isomerization reactions were observed from dioxalanes to dioxanes.

Kinetic energies of charged fragments resulting from multifragmentation and asymmetric fission of the C{sub 60} molecule in collisions with monocharged ions (2-130 keV)

Energy Technology Data Exchange (ETDEWEB)

Rentenier, A; Bordenave-Montesquieu, D; Moretto-Capelle, P; Bordenave-Montesquieu, A [Laboratoire CAR-IRSAMC, UMR 5589 CNRS - Universite Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex (France)

2003-04-28

Multifragmentation and asymmetric fission (AF) of the C{sub 60} molecule induced by H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} ions at medium collision energies (2-130 keV) are considered. Momenta and kinetic energies of C{sub n}{sup +} fragment ions (n = 1- 12) are deduced from an analysis of time-of-flight spectra. In multifragmentation processes, momenta are found to be approximately constant when n > 2, a behaviour which explains that the most probable kinetic energy, as well as the width of the kinetic energy distributions, is found to be inversely proportional to the fragment size n; both momenta and kinetic energies are independent of the velocity and nature of the projectile, and hence of the energy deposit. A specific study of the AF shows that the kinetic energies of C{sub 2}{sup +}, C{sub 4}{sup +} and C{sub 6}{sup +} fragments are also independent of the collision velocity and projectile species; a quantitative agreement is found with values deduced from kinetic energy release measurements by another group in electron impact experiments, and the observed decrease when the mass of the light fragment increases is also reproduced. A quantitative comparison of AF and multifragmentation for the n = 2, 4 and 6 fragment ions shows that kinetic energies in AF exceed that in multifragmentation, a result which explains the oscillations observed when momenta or kinetic energies of fragments are plotted against the n-value. The AF yield is also found to scale with the energy deposit in the collision velocity range extending below the velocity at the maximum of the electronic stopping power; except for protons, it remains negligible with respect to multifragmentation as soon as the total energy deposit exceeds about 100 eV.

A kinetic approach to some quasi-linear laws of macroeconomics

Science.gov (United States)

Gligor, M.; Ignat, M.

2002-11-01

Some previous works have presented the data on wealth and income distributions in developed countries and have found that the great majority of population is described by an exponential distribution, which results in idea that the kinetic approach could be adequate to describe this empirical evidence. The aim of our paper is to extend this framework by developing a systematic kinetic approach of the socio-economic systems and to explain how linear laws, modelling correlations between macroeconomic variables, may arise in this context. Firstly we construct the Boltzmann kinetic equation for an idealised system composed by many individuals (workers, officers, business men, etc.), each of them getting a certain income and spending money for their needs. To each individual a certain time variable amount of money is associated this meaning him/her phase space coordinate. In this way the exponential distribution of money in a closed economy is explicitly found. The extension of this result, including states near the equilibrium, give us the possibility to take into account the regular increase of the total amount of money, according to the modern economic theories. The Kubo-Green-Onsager linear response theory leads us to a set of linear equations between some macroeconomic variables. Finally, the validity of such laws is discussed in relation with the time reversal symmetry and is tested empirically using some macroeconomic time series.

The eddy kinetic energy budget in the Red Sea

KAUST Repository

Zhan, Peng

2016-06-09

The budget of eddy kinetic energy (EKE) in the Red Sea, including the sources, redistributions and sink, is examined using a high-resolution eddy-resolving ocean circulation model. A pronounced seasonally varying EKE is identified, with its maximum intensity occurring in winter, and the strongest EKE is captured mainly in the central and northern basins within the upper 200 m. Eddies acquire kinetic energy from conversion of eddy available potential energy (EPE), from transfer of mean kinetic energy (MKE), and from direct generation due to time-varying (turbulent) wind stress, the first of which contributes predominantly to the majority of the EKE. The EPE-to-EKE conversion occurs almost in the entire basin, while the MKE-to-EKE transfer appears mainly along the shelf boundary of the basin (200 miso-bath) where high horizontal shear interacts with topography. The EKE generated by the turbulent wind stress is relatively small and limited to the southern basin. All these processes are intensified during winter, when the rate of energy conversion is about four to five times larger than that in summer. The EKE is redistributed by the vertical and horizontal divergence of energy flux and the advection of the mean flow. As a main sink of EKE, dissipation processes is ubiquitously found in the basin. The seasonal variability of these energy conversion terms can explain the significant seasonality of eddy activities in the Red Sea. This article is protected by copyright. All rights reserved.

Kinetics in radiation chemistry

International Nuclear Information System (INIS)

Hummel, A.

1987-01-01

In this chapter the authors first briefly review the kinetics of first- and second-order processes for continuous and pulsed irradiation, without taking the effects of nonhomogeneous formation of the species into consideration. They also discuss diffusion controlled reactions under conditions where interactions of more than two particles can be neglected, first the kinetics of the diffusion-controlled reaction of randomly generated species (homogeneous reaction) and then that of isolated pairs of reactants. The latter is often called geminate kinetics when dealing with pairs of oppositely charged species; they shall use this term for the kinetics of isolated pairs in general. In the last section they discuss briefly the kinetics of groups of more than two reactants

Our experience with unusual gastrointestinal tract duplications in infants

Directory of Open Access Journals (Sweden)

Bilal Mirza

2014-01-01

Full Text Available Background: Classical duplications may present along any part of gastrointestinal tract (GIT from mouth to anus. Atypical or unusual rare varieties of GIT duplications may also occur, but with different anatomical features. Materials and Methods: We reviewed our 5-year record (February 2008-January 2013 to describe clinical profile of unusual GIT duplications in neonates and small infants. Results: Three patients with atypical variety of GIT duplications were managed in our department during this tenure. Two were females and one male. Age was ranged between 11 days and 2 months. All patients presented with massive abdominal distension causing respiratory embarrassment in two of them. In all patients, the pre-operative differential diagnoses also included GIT duplication cysts. Computerized tomography (CT scan showed single huge cyst in one and multiple cysts in two patients. In one patient the CT scan also depicted a thoracic cyst in relation to posterior mediastinum. At operation, one patient had colonic tubular duplication cyst along with another isolated duplication cyst, the second case had a tubular duplication cyst of ileum with its segmental dilatation, and in the third case two isolated duplications were found. Duplication cysts were excised along with mucosal stripping in one patient, cyst excision and intestinal resection and anastomosis in one patient, and only cysts excision in one. All patients did well post-operatively. Conclusion: We presented unusual GIT duplications. These duplications are managed on similar lines as classical duplications with good prognosis when dealt early.

An unusual etiology of posttraumatic Collet–Sicard Syndrome: a ...

African Journals Online (AJOL)

A CT-Scan of the neck was performed demonstrating a fracture of the left styloid process at ... The Magnetic Resonance Imaging showed unusually well seen lower cranial ... Six months after the injury a total neurological recovery was noted.

Unusual cause of coma | Jaggi | Malawi Medical Journal

African Journals Online (AJOL)

Journal Home > Vol 8, No 2 (1992) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Unusual cause of coma. P Jaggi, AD Harries. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

Primary periosteal lymphoma - rare and unusual

Energy Technology Data Exchange (ETDEWEB)

Abdelwahab, Ibrahim F. [Coney Island Hospital, Department of Radiology, New York, NY (United States); Hoch, Benjamin [Mount Sinai School of Medicine, CUNY, Department of Pathology, New York, NY (United States); Hermann, George [Mount Sinai School of Medicine, CUNY, Department of Radiology, New York, NY (United States); Bianchi, Stefano [Clinique et Fondation des Grangettes, Geneva (Switzerland); Klein, Michael J. [UAB School of Medicine, Department of Pathology, Birmingham, AL (United States); Springfield, Dempsey S. [Mount Sinai School of Medicine, CUNY, Department of Orthopedics, New York, NY (United States)

2007-04-15

We describe a primary periosteal lymphoma that involved only the periosteum without affecting the adjacent medulla or the regional lymph nodes. No other lymphomatous foci were found in either the distant lymph nodes or viscera. This unusual presentation simulates the imaging appearance of surface lesions of bone, namely benign and malignant tumors, and departs from the typical appearance of primary lymphoma of bone. Therefore, this rare type of lymphoma should be considered in the differential diagnosis of surface bone lesions. (orig.)

An unusual presentation of a glomus tumour.

LENUS (Irish Health Repository)

Nugent, N

2011-02-01

Glomus tumours are benign, soft tissue tumours, usually of fingertips. Classically they present with severe pain, temperature sensitivity and localised tenderness. The diagnosis is often delayed due to sometimes non-specific symptoms and rarity of the disorder. While usually a clinical diagnosis, imaging may be necessary for diagnosis and localisation. We present a case of glomus tumour of the fingertip with an unusual history.

Branchial cleft cyst at an unusual location: a rare case with a brief review

Science.gov (United States)

Panchbhai, A S; Choudhary, M S

2012-01-01

A branchial cleft cyst (BCC) commonly presents as a solitary, painless mass in the neck of a child or young adult. They are most commonly located along the anterior border and the upper third of the sternocleidomastoid muscle in the anterior triangle of the neck. It is very rare for a BCC to manifest in other locations, especially in the posterior triangle of the neck. BCCs are believed to be derived from the branchial apparatus, mostly from the second branchial arch, although many theories have been proposed to explain the aetiology of BCCs. It is possible for BCCs to be easily misdiagnosed as other swellings of oral or paraoral origin owing to their location. Intraoral lymphoepithelial cysts have also been reported in the literature. It is imperative that clinicians make an accurate diagnosis so that appropriate treatment can be performed. If the cysts are excised properly, recurrence is rare. A rare case report of BCC arising in the neck from an unusual location with components in the posterior triangle is presented here. PMID:22116133

Diagnostic considerations concerning a case of an unusual gingivitis

NARCIS (Netherlands)

van der Haring, I.S.; Witjes, M.J.H.

2006-01-01

A young woman presented a severe gingivitis that wouldn't respond to antibiotics prescribed by her general practitioner. Thorough clinical examination showed atypical gingival inflammation. In such unusual cases a careful anamnesis is essential in determining appropriate continued diagnostic

Kinetic equation solution by inverse kinetic method

International Nuclear Information System (INIS)

Salas, G.

1983-01-01

We propose a computer program (CAMU) which permits to solve the inverse kinetic equation. The CAMU code is written in HPL language for a HP 982 A microcomputer with a peripheral interface HP 9876 A ''thermal graphic printer''. The CAMU code solves the inverse kinetic equation by taking as data entry the output of the ionization chambers and integrating the equation with the help of the Simpson method. With this program we calculate the evolution of the reactivity in time for a given disturbance

Why do unusual novel foods like insects lack sensory appeal? Investigating the underlying sensory perceptions

NARCIS (Netherlands)

Tan Hui Shan, Grace; Tibboel, Claudia Joyce; Stieger, Markus

2017-01-01

Unusual novel foods like insects generally hold little sensory appeal for consumers, but little is known about the underlying sensory perceptions and how the properties of the food contribute to acceptance. This study examined the sensory perceptions of 3 unusual novel foods (lamb brain, frog

KINETICS AND MECHANISMS OF NOx - CHAR REDUCTION

Energy Technology Data Exchange (ETDEWEB)

Suuberg, E.M.

1998-06-19

This study was undertaken in order to improve understanding of several aspects of the NO-carbon reaction. This reaction is of practical importance in combustion systems, but its close examination also provides some fundamental insight into oxidizing gas-carbon reactions. As part of this study, a comprehensive literature review of earlier work on this reaction has been published (Aarna and Suuberg, Fuel, 1997, 76, 475-491). It has been thought for some time that the kinetics of the NO-carbon reaction are unusual, in that they often show a two-regime Arrhenius behavior. It has, however, turned out during this work that NO is not alone in this regard. In this laboratory, we also uncovered evidence of two kinetic regime behavior in CO{sub 2} gasification. In another laboratory, a former colleague has identified the same behavior in N{sub 2}O. The low temperature reaction regime always shows an activation energy which is lower than that in the high temperature regime, leaving little doubt that a shift in mechanism, as opposed to transport limitations, dictates the behavior. The activation energy of the low temperature regime of these reactions is typically less than 100 kJ/mol, and the activation energy of the high temperature regime is generally considerably in excess of this value. In this study, we have resolved some apparent inconsistencies in the explanation of the low temperature regime, whose rate has generally been ascribed to desorption-controlled processes. Part of the problem in characterization of the different temperature regimes is that they overlap to a high degree. It is difficult to probe the low temperature regime experimentally, because of slow relaxation of the surface oxides in that regime. Using careful experimental techniques, we were able to demonstrate that the low temperature regime is indeed characterized by zero order in NO, as it must be. A separate study is being carried out to model the behavior in this regime in NO and in other gases, and

Product sampling during transient continuous countercurrent hydrolysis of canola oil and development of a kinetic model

KAUST Repository

Wang, Weicheng

2013-11-01

A chemical kinetic model has been developed for the transient stage of the continuous countercurrent hydrolysis of triglycerides to free fatty acids and glycerol. Departure functions and group contribution methods were applied to determine the equilibrium constants of the four reversible reactions in the kinetic model. Continuous countercurrent hydrolysis of canola oil in subcritical water was conducted experimentally in a lab-scale reactor over a range of temperatures and the concentrations of all neutral components were quantified. Several of the rate constants in the model were obtained by modeling this experimental data, with the remaining determined from calculated equilibrium constants. Some reactions not included in the present, or previous, hydrolysis modeling efforts were identified from glycerolysis kinetic studies and may explain the slight discrepancy between model and experiment. The rate constants determined in this paper indicate that diglycerides in the feedstock accelerate the transition from "emulsive hydrolysis" to "rapid hydrolysis". © 2013 Elsevier Ltd.

Unusual energy properties of leaky backward Lamb waves in a submerged plate.

Science.gov (United States)

Nedospasov, I A; Mozhaev, V G; Kuznetsova, I E

2017-05-01

It is found that leaky backward Lamb waves, i.e. waves with negative energy-flux velocity, propagating in a plate submerged in a liquid possess extraordinary energy properties distinguishing them from any other type of waves in isotropic media. Namely, the total time-averaged energy flux along the waveguide axis is equal to zero for these waves due to opposite directions of the longitudinal energy fluxes in the adjacent media. This property gives rise to the fundamental question of how to define and calculate correctly the energy velocity in such an unusual case. The procedure of calculation based on incomplete integration of the energy flux density over the plate thickness alone is applied. The derivative of the angular frequency with respect to the wave vector, usually referred to as the group velocity, happens to be close to the energy velocity defined by this mean in that part of the frequency range where the backward mode exists in the free plate. The existence region of the backward mode is formally increased for the submerged plate in comparison to the free plate as a result of the liquid-induced hybridization of propagating and nonpropagating (evanescent) Lamb modes. It is shown that the Rayleigh's principle (i.e. equipartition of total time-averaged kinetic and potential energies for time-harmonic acoustic fields) is violated due to the leakage of Lamb waves, in spite of considering nondissipative media. Copyright © 2017 Elsevier B.V. All rights reserved.

A solitary bronchial papilloma with unusual endoscopic presentation: case study and literature review

Directory of Open Access Journals (Sweden)

Frejeville Marie

2009-08-01

Full Text Available Abstract Background Solitary endobronchial papillomas (SEP are rare tumors and most of them are described by case report. A misdiagnosis is common with viral related papillomas. A histopathological classification has recently permitted a major advancement in the understanding of the disease. Case Presentation We report a case of a mixed bronchial papilloma with an unusual endoscopic presentation. The literature was extensively reviewed to ascertain the unusual characteristics of the current case. A 39-year of age male was referred to our institution for the investigation of a slight hemoptysis. Routine examination was normal. A fibroscopy revealed an unusual feature of the right main bronchus. The lesion was a plane, non-bleeding, non-glistering sub-mucosal proliferation. No enhanced coloration was noticed. Biopsies revealed a mixed solitary bronchial papilloma. In situ HPV hybridization was negative. Endoscopic treatment (electrocautery was effective with no relapse. Conclusion This lesion contrasts with the data of the literature where papilloma were described as wart-like lesions or cauliflower tumors, with symptoms generally related to bronchial obstruction. We advise chest physicians to be cautious with unusually small swollen lesions of the bronchi that may reveal a solitary bronchial papilloma. Endoscopic imaging can significantly contribute to the difficult diagnosis of SEP by pulmonary physicians and endoscopists.

Introduction to chemical kinetics

CERN Document Server

Soustelle, Michel

2013-01-01

This book is a progressive presentation of kinetics of the chemical reactions. It provides complete coverage of the domain of chemical kinetics, which is necessary for the various future users in the fields of Chemistry, Physical Chemistry, Materials Science, Chemical Engineering, Macromolecular Chemistry and Combustion. It will help them to understand the most sophisticated knowledge of their future job area. Over 15 chapters, this book present the fundamentals of chemical kinetics, its relations with reaction mechanisms and kinetic properties. Two chapters are then devoted to experimental re

Kinetic, volumetric and structural effects induced by liquid Ga penetration into ultrafine grained Al

International Nuclear Information System (INIS)

Naderi, Mehrnoosh; Peterlechner, Martin; Schafler, Erhard; Divinski, Sergiy V.; Wilde, Gerhard

2015-01-01

Kinetic, volumetric and structural effects induced by penetration of liquid Ga in ultrafine grained (UFG) Al produced by severe plastic deformation using high-pressure torsion were studied by isothermal dilatometric measurements, electron microscopy, atomic force microscopy and X-ray diffraction. Severe plastic deformation changed the distribution of impurities and their segregation was revealed by transmission electron microscopy. Two-stage length changes of UFG Al were observed which are explained by counteracting effects of expansion due to grain boundary segregation of Ga and contraction due to precipitation and recrystallization. After applying Ga, the kinetics of the liquid Ga penetration in UFG Al is studied in-situ in the electron microscope by the “first appearance” method and the time scales are in agreement with those inducing the volumetric changes

Comparative analysis of mineral and secundary raw materials screening kinetics

Directory of Open Access Journals (Sweden)

Stojanović Aleksandra

2015-01-01

Full Text Available Efficiency of screening shows screening performance compared to an ideal screening to achieve a complete separation of the fractions without the presence of grains of size less than the mesh openings left on sieve and grains of size larger than the mesh opening that passed through the sieve. Efficiency is growing rapidly and after a certain time is reduced. This is explained by the fact that the speed of screening depends on the percentage of 'small', 'small-to large' and 'large' grain. The paper shows how for the given grain, their shape and density affect the kinetics of screening.

Supercritical kinetic analysis in simplified system of fuel debris using integral kinetic model

International Nuclear Information System (INIS)

Tuya, Delgersaikhan; Obara, Toru

2016-01-01

Highlights: • Kinetic analysis in simplified weakly coupled fuel debris system was performed. • The integral kinetic model was used to simulate criticality accidents. • The fission power and released energy during simulated accident were obtained. • Coupling between debris regions and its effect on the fission power was obtained. - Abstract: Preliminary prompt supercritical kinetic analyses in a simplified coupled system of fuel debris designed to roughly resemble a melted core of a nuclear reactor were performed using an integral kinetic model. The integral kinetic model, which can describe region- and time-dependent fission rate in a coupled system of arbitrary geometry, was used because the fuel debris system is weakly coupled in terms of neutronics. The results revealed some important characteristics of coupled systems, such as the coupling between debris regions and the effect of the coupling on the fission rate and released energy in each debris region during the simulated criticality accident. In brief, this study showed that the integral kinetic model can be applied to supercritical kinetic analysis in fuel debris systems and also that it can be a useful tool for investigating the effect of the coupling on consequences of a supercritical accident.

Original article Urethral Stricture and HIV: Unusual Presentations ...

African Journals Online (AJOL)

mn

cause of urethral stricture in this series was traumatic injury The other important cause was post-inflammatory (after gonococcal urethritis) with HIV co-infection. These patients posed a challenge due to our lack of experience and the absence of literature guidelines on the optimal management. The first unusual feature in the ...

Spinal Metastasis Of Wilm's Tumuor: An Unusual Occurrence ...

African Journals Online (AJOL)

Background: Metastasis of the Wilm's tumor is usually to surrounding tissue, the lungs and the liver. Rarely is there spread to bone, bone-marrow, spinal canal and other tissues, but this unusual mode of spread sometimes occurs. Objectives: To report a case of Wilm's tumuor complicated by spastic paraplegia consequent to ...

Unusual Presentation of Meningitis following Stab Neck | Motsitsi ...

African Journals Online (AJOL)

Background: A case report of stab neck presenting at Kalafong Hospital, Pretoria, South Africa with atypical meningitis. The objective was to illustrate the challenge of diagnosing this unusual and late presentation of meningitis. Case Report: A 48 year-old male patient presented to us two days after a stab neck. He was ...

endodontic treatment of unusually long discolored maxillary central ...

African Journals Online (AJOL)

a few cases of dual–rooted maxillary central incisor have been reported in literature1-5. Maxillary central incisors vary in root ... The following case report describes the endodontic management of a patient with an unusually long maxillary central incisor in our environment. CASE PROFILE. A 31 year-old male was referred ...

Principles of chemical kinetics

CERN Document Server

House, James E

2007-01-01

James House's revised Principles of Chemical Kinetics provides a clear and logical description of chemical kinetics in a manner unlike any other book of its kind. Clearly written with detailed derivations, the text allows students to move rapidly from theoretical concepts of rates of reaction to concrete applications. Unlike other texts, House presents a balanced treatment of kinetic reactions in gas, solution, and solid states. The entire text has been revised and includes many new sections and an additional chapter on applications of kinetics. The topics covered include quantitative rela

Unusual bond paths in organolithium compounds

International Nuclear Information System (INIS)

Bachrach, S.M.; Ritchie, J.P.

1986-01-01

We have applied the topological method to a number of organolithium compounds. The wavefunctions were determined with GAUSSIAN-82 using 3-21G basis set and fully optimized geometries. Gradient paths were obtained using the RHODER package and critical points were located using EXTREME. These results indicate the unusual nature of organolithium compounds. The strange bond paths arise mainly from the ionic nature of the C-Li interaction. We suggest that the term ''bond path'' may best be suited for covalent bonds. 4 figs., 1 tab

An unusual presentation of testicular tumor

International Nuclear Information System (INIS)

Amin, M.U.; Rahan, T.; Haq, A.U.; Aftab, P.

2006-01-01

A case of testicular choriocarcinoma is reported in which blood mixed stools and haemoptysis were the presenting manifestations as the patient never told about the testicular swelling to his parents. Orchidectomy was performed but the patient presented again with massive hematemesis due to gastric perforation secondary to gastric metastasis. The size of the testis at diagnosis was approximately 12 x 7cm. This was also unusual as testicular choriocarcinoma presents as a small mass. The patient eventually died of the complications within one month of diagnosis. (author)

Uniportal anatomic combined unusual segmentectomies.

Science.gov (United States)

González-Rivas, Diego; Lirio, Francisco; Sesma, Julio

2017-01-01

Nowadays, sublobar anatomic resections are gaining momentum as a valid alternative for early stage lung cancer. Despite being technically demanding, anatomic segmentectomies can be performed by uniportal video-assisted thoracic surgery (VATS) approach to combine the benefits of minimally invasiveness with the maximum lung sparing. This procedure can be even more complex if a combined resection of multiple segments from different lobes has to be done. Here we report five cases of combined and unusual segmentectomies done by the same experienced surgeon in high volume institutions to show uniportal VATS is a feasible approach for these complex resections and to share an excellent educational resource.

Unusual magnetoresistance in cubic B20 Fe0.85Co0.15Si chiral magnets

Science.gov (United States)

Huang, S. X.; Chen, Fei; Kang, Jian; Zang, Jiadong; Shu, G. J.; Chou, F. C.; Chien, C. L.

2016-06-01

The B20 chiral magnets with broken inversion symmetry and C4 rotation symmetry have attracted much attention. The broken inversion symmetry leads to the Dzyaloshinskii-Moriya that gives rise to the helical and Skyrmion states. We report the unusual magnetoresistance (MR) of B20 chiral magnet Fe0.85Co0.15Si that directly reveals the broken C4 rotation symmetry and shows the anisotropic scattering by Skyrmions with respect to the current directions. The intimacy between unusual MR and broken symmetry is well confirmed by theoretically studying an effective Hamiltonian with spin-orbit coupling. The unusual MR serves as a transport signature for the Skyrmion phase.

Unusual magnetoresistance in cubic B20 Fe0.85Co0.15Si chiral magnets

International Nuclear Information System (INIS)

Huang, S X; Chen, Fei; Zang, Jiadong; Chien, C L; Kang, Jian; Shu, G J; Chou, F C

2016-01-01

The B20 chiral magnets with broken inversion symmetry and C 4 rotation symmetry have attracted much attention. The broken inversion symmetry leads to the Dzyaloshinskii–Moriya that gives rise to the helical and Skyrmion states. We report the unusual magnetoresistance (MR) of B20 chiral magnet Fe 0.85 Co 0.15 Si that directly reveals the broken C 4 rotation symmetry and shows the anisotropic scattering by Skyrmions with respect to the current directions. The intimacy between unusual MR and broken symmetry is well confirmed by theoretically studying an effective Hamiltonian with spin–orbit coupling. The unusual MR serves as a transport signature for the Skyrmion phase. (paper)

Purulent meningitis with unusual diffusion-weighted MRI findings

International Nuclear Information System (INIS)

Abe, M.; Takayama, Y.; Yamashita, H.; Noguchi, M.; Sagoh, T.

2002-01-01

We describe unusual findings obtained by diffusion-weighted magnetic resonance imaging (MRI) in a patient with acute purulent meningitis caused by penicillin-resistant Streptococcus pneumoniae. Along cerebral convexities and the Sylvian fissure, multiple small intense lesions showed high signal intensity in these sequences. This may be the first report of diffusion-weighted in purulent meningitis

An unusual presentation of juvenile lupus nephritis

Directory of Open Access Journals (Sweden)

Malleshwar Bottu

2016-01-01

Full Text Available The incidence of juvenile lupus varies widely ranging between 4 and 250 per 100,000 population. Most common organ involvement in juvenile lupus is kidney. Neurological, cutaneous and hematological involvements are also involved. Skeletal muscle involvement in the form of myositis is rare. Myositis as presenting manifestation in juvenile lupus is also unusual. Herein, we report one such case wherein myositis preceded the onset of lupus nephritis

An unusual cause of anemia and encephalopathy

Directory of Open Access Journals (Sweden)

Sanjeev Kumar Sharma

2015-04-01

Full Text Available The authors present here an interesting case of recent onset anemia that was associated with an encephalopathy of the unusual cause.Although severe anemia can theoretically result in anemic hypoxia and can then lead to hypoxic encephalopathy, it is not a primary cause of encephalopathy. More frequently anemia can contribute together with other multiple causes of encephalopathy, such as infections, metabolic abnormalities, trauma, hepatic dysfunction, hypertension, toxins.

Primary malignant peripheral nerve sheath tumor at unusual location

Directory of Open Access Journals (Sweden)

Souvagya Panigrahi

2013-01-01

Full Text Available Malignant peripheral nerve sheath tumor (MPNST is a rare soft tissue sarcoma. Most arise in association with major nerve trunks. Their most common anatomical sites are the proximal portions of the upper and lower extremities and the trunk. MPNSTs have rarely been reported in literature to occur in other unusual body parts. We review all such cases reported till now in terms of site of origin, surgical treatment, adjuvant therapy and outcome and shortly describe our experience with two of these cases. Both of our case presented with lump at unusual sites resembling neurofibroma, one at orbitotemporal area and other in the paraspinal region with characteristic feature of neurofibroma with the exception that both had very short history of progression. They underwent gross total removal of the tumor with adjuvant radiotherapy postoperatively. At 6-month follow-up both are doing well with no evidence of recurrence.

Plasma kinetic theory

International Nuclear Information System (INIS)

Elliott, J.A.

1993-01-01

Plasma kinetic theory is discussed and a comparison made with the kinetic theory of gases. The plasma is described by a modified set of fluid equations and it is shown how these fluid equations can be derived. (UK)

Kinetic Control of Aqueous Hydrolysis: Modulating Structure/Property Relationships in Inorganic Crystals

Science.gov (United States)

Neilson, James R.

2011-12-01

A grand challenge in materials science and chemistry revolves around the preparation of materials with desired properties by controlling structure on multiple length scales. Biology approaches this challenge by evolving tactics to transform soluble precursors into materials and composites with macro-scale and atomic precision. Studies of biomineralization in siliceous sponges led to the discovery of slow, catalytic hydrolysis of molecular precursors in the biogenesis of silica skeletal elements with well defined micro- and nano-scale architectures. However, the role of aqueous hydrolysis in the limit of kinetic control is not well understood; this allows us to form a central hypothesis: that the kinetics of hydrolysis modulate the structures of materials and their properties. As a model system, the diffusion of a simple hydrolytic catalyst (such as ammonia) across an air-water interface into a metal salt solution reproduces some aspects of the chemistry found in biomineralization, namely kinetic and vectorial control. Variation of the catalyst concentration modulates the hydrolysis rate, and thus alters the resulting structure of the inorganic crystals. Using aqueous solutions of cobalt(II) chloride, each product (cobalt hydroxide chloride) forms with a unique composition, despite being prepared from identical mother liquors. Synchrotron X-ray total scattering methods are needed to locate the atomic positions in the material, which are not aptly described by a traditional crystallographic unit cell due to structural disorder. Detailed definition of the structure confirms that the hydrolysis conditions systematically modulate the arrangement of atoms in the lattice. This tightly coupled control of crystal formation and knowledge of local and average structures of these materials provides insight into the unusual magnetic properties of these cobalt hydroxides. The compounds studied show significant and open magnetization loops with little variation with composition

UNUSUALLY WIDE BINARIES: ARE THEY WIDE OR UNUSUAL?

International Nuclear Information System (INIS)

Kraus, Adam L.; Hillenbrand, Lynne A.

2009-01-01

We describe an astrometric and spectroscopic campaign to confirm the youth and association of a complete sample of candidate wide companions in Taurus and Upper Sco. Our survey found 15 new binary systems (three in Taurus and 12 in Upper Sco) with separations of 3''-30'' (500-5000 AU) among all of the known members with masses of 2.5-0.012 M sun . The total sample of 49 wide systems in these two regions conforms to only some expectations from field multiplicity surveys. Higher mass stars have a higher frequency of wide binary companions, and there is a marked paucity of wide binary systems near the substellar regime. However, the separation distribution appears to be log-flat, rather than declining as in the field, and the mass ratio distribution is more biased toward similar-mass companions than the initial mass function or the field G-dwarf distribution. The maximum separation also shows no evidence of a limit at ∼ sun . We attribute this result to the post-natal dynamical sculpting that occurs for most field systems; our binary systems will escape to the field intact, but most field stars are formed in denser clusters and undergo significant dynamical evolution. In summary, only wide binary systems with total masses ∼ sun appear to be 'unusually wide'.

Kinetic study of oil extraction from olive foot cake

Directory of Open Access Journals (Sweden)

Lamrous, O.

2006-06-01

Full Text Available The kinetics of oil extraction from olive foot cake can be explained by a model based on two stages. The first step corresponds to a simple washing of the oil from the particle surface. In the second step, the extraction is controlled by two mechanisms: slow diffusion from broken cells and very slow diffusion from intact cells.The kinetic coefficients of this mathematical model are calculated using the experimental results obtained from hexane and commercial ethyl alcohol for different particle sizes.La cinética de extracción de aceite de orujo puede ser explicada por un modelo basado en dos etapas. La primera etapa corresponde a un simple lavado del aceite de la superficie de las partículas. En la segunda etapa, la extracción esta controlada por dos mecanismos: difusión lenta desde las células rotas y difusión muy lenta desde las células intactas.Los coeficientes cinéticas de este modelo matemático se calculan usando los resultados experimentales obtenidos con hexano y alcohol etílico comercial para diferentes tamaños de partícula.

Northern Gulf of Mexico Marine Mammal Unusual Mortality Event Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Tissues and samples collected from marine mammals during investigation of the Northern Gulf of Mexico Marine Mammal Unusual Mortality Event are tracked within this...

DETAILED CHEMICAL ABUNDANCES OF FOUR STARS IN THE UNUSUAL GLOBULAR CLUSTER PALOMAR 1

International Nuclear Information System (INIS)

Sakari, Charli M.; Venn, Kim A.; Irwin, Mike; Aoki, Wako; Arimoto, Nobuo; Dotter, Aaron

2011-01-01

Detailed chemical abundances for 21 elements are presented for four red giants in the anomalous outer halo globular cluster Palomar 1 (R GC = 17.2 kpc, Z = 3.6 kpc) using high-resolution (R = 36, 000) spectra from the High Dispersion Spectrograph on the Subaru Telescope. Pal 1 has long been considered unusual because of its low surface brightness, sparse red giant branch, young age, and its possible association with two extragalactic streams of stars. This paper shows that its chemistry further confirms its unusual nature. The mean metallicity of the four stars, [Fe/H] = -0.60 ± 0.01, is high for a globular cluster so far from the Galactic center, but is low for a typical open cluster. The [α/Fe] ratios, though in agreement with the Galactic stars within the 1σ errors, agree best with the lower values in dwarf galaxies. No signs of the Na/O anticorrelation are detected in Pal 1, though Na appears to be marginally high in all four stars. Pal 1's neutron-capture elements are also unusual: its high [Ba/Y] ratio agrees best with dwarf galaxies, implying an excess of second-peak over first-peak s-process elements, while its [Eu/α] and [Ba/Eu] ratios show that Pal 1's contributions from the r-process must have differed in some way from normal Galactic stars. Therefore, Pal 1 is unusual chemically, as well in its other properties. Pal 1 shares some of its unusual abundance characteristics with the young clusters associated with the Sagittarius dwarf galaxy remnant and the intermediate-age LMC clusters, and could be chemically associated with the Canis Majoris overdensity; however, it does not seem to be similar to the Monoceros/Galactic Anticenter Stellar Stream.

Ruptured rectal duplication with urogenital abnormality: Unusual presentation.

Science.gov (United States)

Solanki, Shailesh; Babu, M Narendra; Jadhav, Vinay; Shankar, Gowri; Santhanakrishnan, Ramesh

2015-01-01

Rectal duplication (RD) accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD.

An unusual presentation of toothpick penetration of colon

OpenAIRE

Wani, Imtiaz; Wani, Shamima A; Mir, Shabir; Parra, Khursheed

2010-01-01

This case report presents the delayed unusual presentation of plastic toothpick penetrating transverse colon 3 months after ingestion with localized peritonitis. Role of omentum "policeman of abdomen" for salvage is highlighted. Careful observation and long-term lookup for any neglected ingested foreign body are stressed. The delayed presentation can be sometimes proving as a surgical emergency.

An unusual presentation of toothpick penetration of colon

Directory of Open Access Journals (Sweden)

Wani Imtiaz

2010-01-01

Full Text Available This case report presents the delayed unusual presentation of plastic toothpick penetrating transverse colon 3 months after ingestion with localized peritonitis. Role of omentum "policeman of abdomen" for salvage is highlighted. Careful observation and long-term lookup for any neglected ingested foreign body are stressed. The delayed presentation can be sometimes proving as a surgical emergency.

An unusual foreign body in the preputial sac.

Science.gov (United States)

Jaiswal, A K

1992-01-01

A 28 year old Indian male presented with an unusual foreign body, a penicillin bottle containing tincture of iodine, in the preputial sac. The purpose of introducing the bottle was to tickle his glans penis as a form of masturbation. The bottle was so firmly impacted that it could be removed only under general anaesthesia. Images PMID:1427809

Spondylo-megaepiphyseal-metaphyseal dysplasia: an unusual bone dysplasia

International Nuclear Information System (INIS)

Agarwal, Prachi Pragya; Srinivasan, Ashok; Sharma, Raju; Gupta, Arun Kumar; Kabra, Madhulika

2003-01-01

A rare case of spondylo-megaepiphyseal-metaphyseal dysplasia is reported in a 10-year-old boy. The features were metaphyseal dysplasia, markedly defective ossification of vertebral body centres and enlarged epiphyses. Although it shares some features with spondylo-metaphyseal dysplasia, oto-spondylo-megaepiphyseal dysplasia and cleidocranial dysplasia, the presence of several unusual radiological findings sets it apart. (orig.)

Hepatobiliary fascioliasis: a case with unusual radiological features.

Science.gov (United States)

Yeşildağ, Ahmet; Senol, Altuğ; Köroğlu, Mert; Koçkar, Cem; Oyar, Orhan; Işler, Mehmet

2010-12-01

We report a case of hepatobiliary fascioliasis presenting with unusual radiological findings that have not been reported previously. Imaging studies revealed hepatic cystic pouches communicating with intrahepatic bile ducts. Snail-like, oval shaped and conglomerated echogenic particles with no acoustic shadowing, suggesting F. hepatica, were detected in these cystic pouches. In addition, secondary sclerosing cholangitis developed after fascioliasis.

Unusual blunt force wound produced by a gun muzzle.

Science.gov (United States)

Hanzlick, R; Zaki, S A

1986-09-01

Most blunt force injuries produced by guns are associated with gun butts, and patterned, muzzle/sight impressions are usually produced by discharging firearms. An unusual and distinct forehead laceration produced by a blow with the muzzle end of a .32 caliber revolver is presented.

Kinetic Interface

DEFF Research Database (Denmark)

2009-01-01

A kinetic interface for orientation detection in a video training system is disclosed. The interface includes a balance platform instrumented with inertial motion sensors. The interface engages a participant's sense of balance in training exercises.......A kinetic interface for orientation detection in a video training system is disclosed. The interface includes a balance platform instrumented with inertial motion sensors. The interface engages a participant's sense of balance in training exercises....

Proliferation kinetics and cyclic AMP as prognostic factors in adult acute leukemia.

Science.gov (United States)

Paietta, E; Mittermayer, K; Schwarzmeier, J

1980-07-01

In 41 adult patients with acute leukemia (myeloblastic, lymphoblastic, and undifferentiated), proliferation kinetics (as determined by double-label autoradiography) and cyclic adenosine 3',5'-monophosphate (cAMP) concentration were studied for their significance in the prediction of responsiveness to cytostatic therapy. Patients with good clinical response had significantly shorter turnover times and higher labeling indices in the bone marrow than did those who failed to respond to treatment. Cases for which cell kinetics did not correlate with clinical response were explained by variance in the distribution of leukemic blasts between the proliferative cell cycle and the resting pool. Good clinical response was also found to be associated with low levels of cAMP in leukemic cells prior to therapy, whereas high cAMP contents predicted failure. Low cAMP concentrations, however, did not necessarily correlate with short turnover times and vice versa. This might be due to fluctuations of the cAMP concentrations during the cell cycle.

Unusual case of congenital/infantile fibrosarcoma in a new born

Directory of Open Access Journals (Sweden)

Eddiba Tarik

2013-01-01

Full Text Available Congenital infantile fibrosarcoma (CIFS is a rare mesenchymal tumor that is primarily developed in the soft tissue of distal extremities and occasionally in unusual locations such as the lung and retroperitoneum. It occurs mainly in children below the age of 5 years. About 200 cases have been reported in the literature so far, very few of them in new-borns. The prognosis of this tumor is relatively good compared to adult forms. We report an unusual case of CIFS occurring in new-born mimicking an hemangioma and causing hemorrhage in the neonatal period. The tumor is located in the left arm and axilla and associated with a hand malformation. A shoulder amputation is performed after chemotherapy failure. The infant is now two-years old with no recurrence.

Carbon isotope discrimination during litter decomposition can be explained by selective use of substrate with differing δ13C

Science.gov (United States)

Ngao, J.; Cotrufo, M. F.

2011-01-01

Temporal dynamics of C isotopic composition (δ13C) of CO2 and leaf litter was monitored during a litter decomposition experiment using Arbutus unedo L., as a slow decomposing model substrate. This allowed us (1) to quantify isotopic discrimination variation during litter decomposition, and (2) to test whether selective substrate use or kinetic fractionation could explain the observed isotopic discrimination. Total cumulative CO2-C loss (CL) comprised 27% of initial litter C. Temporal evolution of CL was simulated following a three-C-pool model. Isotopic composition of respired CO2 (δRL) was higher with respect to that of the bulk litter. The isotopic discrimination Δ(L/R) varied from -2‰ to 0‰ and it is mostly attributed to the variations of δRL. A three-pool model, with the three pools differing in their δ13C, described well the dynamic of Δ(L/R), in the intermediate stage of the process. This suggests that the observed isotopic discrimination between respired CO2 and bulk litter is in good agreement with the hypothesis of successive consumption of C compounds differing in δ13C during decomposition. However, to explain also 13C-CO2 dynamics at the beginning and end of the incubation the model had to be modified, with discrimination factors ranging from -1‰ to -4.6‰ attributed to the labile and the recalcitrance pool, respectively. We propose that this discrimination is also the result of further selective use of specific substrates within the two pools, likely being both the labile and recalcitrant pool of composite nature. In fact, the 2‰ 13C enrichment of the α-cellulose observed by the end of the experiment, and potentially attributable to kinetic fractionation, could not explain the measured Δ(L/R) dynamics.

Kinetics of carbonate mineral dissolution in CO2-acidified brines at storage reservoir conditions.

Science.gov (United States)

Peng, Cheng; Anabaraonye, Benaiah U; Crawshaw, John P; Maitland, Geoffrey C; Trusler, J P Martin

2016-10-20

We report experimental measurements of the dissolution rate of several carbonate minerals in CO 2 -saturated water or brine at temperatures between 323 K and 373 K and at pressures up to 15 MPa. The dissolution kinetics of pure calcite were studied in CO 2 -saturated NaCl brines with molalities of up to 5 mol kg -1 . The results of these experiments were found to depend only weakly on the brine molality and to conform reasonably well with a kinetic model involving two parallel first-order reactions: one involving reactions with protons and the other involving reaction with carbonic acid. The dissolution rates of dolomite and magnesite were studied in both aqueous HCl solution and in CO 2 -saturated water. For these minerals, the dissolution rates could be explained by a simpler kinetic model involving only direct reaction between protons and the mineral surface. Finally, the rates of dissolution of two carbonate-reservoir analogue minerals (Ketton limestone and North-Sea chalk) in CO 2 -saturated water were found to follow the same kinetics as found for pure calcite. Vertical scanning interferometry was used to study the surface morphology of unreacted and reacted samples. The results of the present study may find application in reactive-flow simulations of CO 2 -injection into carbonate-mineral saline aquifers.

Stopped-flow kinetic studies of poly(amidoamine) dendrimer-calf thymus DNA to form dendriplexes.

Science.gov (United States)

Dey, Debabrata; Kumar, Santosh; Maiti, Souvik; Dhara, Dibakar

2013-11-07

Poly(amidoamine) (PAMAM) dendrimers are known to be highly efficient nonviral carriers in gene delivery. Dendrimer-mediated transfection is known to be a function of the dendrimer to DNA charge ratio as well as the size of the dendrimer. In the present study, the binding kinetics of four PAMAM dendrimers (G1, G2, G3, and G4) with calf thymus DNA (CT-DNA) has been studied using stopped-flow fluorescence spectroscopy. The effect of dendrimer-to-DNA charge ratio and dendrimer generation on the binding kinetics was investigated. In most cases, the results of dendrimer-CT-DNA binding can be explained by a two-step reaction mechanism: a rapid electrostatic binding between the dendrimer and DNA, followed by a conformational change of the dendrimer-DNA complex that ultimately leads to DNA condensation. It was observed that the charge ratio on the dendrimer and the DNA phosphate groups, as well as the dendrimer generation (size), has a marked effect on the kinetics of binding between the DNA and the dendrimers. The rate constant (k'1) of the first step was much higher compared to that of the second step (k'2), and both were found to increase with an increase in dendrimer concentration. Among the four generations of dendrimers, G4 exhibited significantly faster binding kinetics compared to the three smaller generation dendrimers.

An investigation of the general regularity of size dependence of reaction kinetics of nanoparticles

International Nuclear Information System (INIS)

Cui, Zixiang; Duan, Huijuan; Xue, Yongqiang; Li, Ping

2015-01-01

In the processes of preparation and application of nanomaterials, the chemical reactions of nanoparticles are often involved, and the size of nanoparticles has dramatic influence on the reaction kinetics. Nevertheless, there are many conflicts on regularities of size dependence of reaction kinetic parameters, and these conflicts have not been explained so far. In this paper, taking the reaction of nano-ZnO (average diameter is from 20.96 to 53.31 nm) with acrylic acid solution as a system, the influence regularities of the particle size on the kinetic parameters were researched. The regularities were consistent with that in most literatures, but inconsistent with that in a few of literatures, the reasons for the conflicts were interpreted. The reasons can be attributed to two factors: one is improper data processing for fewer data points, and the other is the difference between solid particles and porous particles. A general regularity of the size dependence of reaction kinetics for solid particles was obtained. The regularity shows that with the size of nanoparticles decreasing, the rate constant and the reaction order increase, while the apparent activation energy and the pre-exponential factor decrease; and the relationships of the logarithm of rate constant, the logarithm of pre-exponential factor, and the apparent activation energy to the reciprocal of the particle size are linear, respectively

Large abdominal-pelvic cyst: An unusual presentation of hepatic echinococcosis

Energy Technology Data Exchange (ETDEWEB)

Borre, D.G.; Borre, G.E.

1988-10-01

The authors present an unusual form of hepatic echinococcosis characterized by a cystic mass that occupied the whole abdomen. The clinical features and the results of the diagnostic imaging procedures (ultrasound, computed tomography) are commented.

Pressure effect on crystallization kinetics in Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glass

DEFF Research Database (Denmark)

Jiang, Jianzhong; Gerward, Leif; Xu, Y.S.

2002-01-01

Crystallization kinetics of a Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glass in the supercooled liquid region have been investigated by performing in situ high-temperature and high-pressure x-ray diffraction measurements using synchrotron radiation. A pressure-time-temperature-transformation diagram......, describing the onset of crystallization as a function of time during isothermal annealing under pressure, is presented. Different pressure dependences of crystallization kinetics in the temperature range for the glass have been observed and further be explained by a model of competing processes...

The unusual gamma-ray burst GRB 101225A explained as a minor body falling onto a neutron star.

Science.gov (United States)

Campana, S; Lodato, G; D'Avanzo, P; Panagia, N; Rossi, E M; Della Valle, M; Tagliaferri, G; Antonelli, L A; Covino, S; Ghirlanda, G; Ghisellini, G; Melandri, A; Pian, E; Salvaterra, R; Cusumano, G; D'Elia, V; Fugazza, D; Palazzi, E; Sbarufatti, B; Vergani, S D

2011-11-30

The tidal disruption of a solar-mass star around a supermassive black hole has been extensively studied analytically and numerically. In these events, the star develops into an elongated banana-shaped structure. After completing an eccentric orbit, the bound debris falls into the black hole, forming an accretion disk and emitting radiation. The same process may occur on planetary scales if a minor body passes too close to its star. In the Solar System, comets fall directly into our Sun or onto planets. If the star is a compact object, the minor body can become tidally disrupted. Indeed, one of the first mechanisms invoked to produce strong gamma-ray emission involved accretion of comets onto neutron stars in our Galaxy. Here we report that the peculiarities of the 'Christmas' gamma-ray burst (GRB 101225A) can be explained by a tidal disruption event of a minor body around an isolated Galactic neutron star. This would indicate either that minor bodies can be captured by compact stellar remnants more frequently than occurs in the Solar System or that minor-body formation is relatively easy around millisecond radio pulsars. A peculiar supernova associated with a gamma-ray burst provides an alternative explanation.

Kinetics of soil dehydrogenase in response to exogenous Cd toxicity

Energy Technology Data Exchange (ETDEWEB)

Tan, Xiangping [College of Natural Resources and Environment, Northwest A& F University, Yangling, 712100, Shaanxi (China); Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, CAS 723 Xingke Rd., Tianhe District, Guangzhou 510650 (China); Wang, Ziquan; Lu, Guannan [College of Natural Resources and Environment, Northwest A& F University, Yangling, 712100, Shaanxi (China); He, Wenxiang, E-mail: wenxianghe@nwafu.edu.cn [College of Natural Resources and Environment, Northwest A& F University, Yangling, 712100, Shaanxi (China); Key Laboratory of Plant Nutrition and Agro-environment in Northwest China, Ministry of Agriculture, Northwest A& F University, Yangling, 712100, Shaanxi (China); Wei, Gehong [College of Life Sciences, Northwest A& F University, Yangling, 712100, Shaanxi (China); Huang, Feng; Xu, Xinlan; Shen, Weijun [Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, CAS 723 Xingke Rd., Tianhe District, Guangzhou 510650 (China)

2017-05-05

Highlights: • pH explained 30–45% of the dehydrogenase activity (DHA), V{sub max}, and K{sub m} variations across soils. • Different inhibition mechanism of Cd to DHA varied soil types. • Soil properties and inhibition constant affect the toxicity of Cd. • Reaction constant (k) could indicate sensitively the toxicity of Cd to DHA. - Abstract: Soil dehydrogenase plays a role in the biological oxidation of soil organic matter and can be considered a good measure of the change of microbial oxidative activity under environmental pollutions. However, the kinetic characteristic of soil dehydrogenase under heavy metal stresses has not been investigated thoroughly. In this study, we characterized the kinetic characteristic of soil dehydrogenase in 14 soil types, and investigated how kinetic parameters changed under spiked with different concentrations of cadmium (Cd). The results showed that the K{sub m} and V{sub max} values of soil dehydrogenase was among 1.4–7.3 mM and 15.9–235.2 μM h{sup −1} in uncontaminated soils, respectively. In latosolic red soil and brown soil, the inhibitory kinetic mechanism of Cd to soil dehydrogenase was anticompetitive inhibition with inhibition constants (K{sub i}) of 12 and 4.7 mM, respectively; in other soils belonged to linear mixed inhibition, the values of K{sub i} were between 0.7–4.2 mM. Soil total organic carbon and K{sub i} were the major factors affecting the toxicity of Cd to dehydrogenase activity. In addition, the velocity constant (k) was more sensitive to Cd contamination compared to V{sub max} and K{sub m}, which was established as an early indicator of gross changes in soil microbial oxidative activity caused by Cd contamination.

Chemical composition of HAL, an isotopically-unusual Allende inclusion

Science.gov (United States)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-01-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

Kinetics and

Directory of Open Access Journals (Sweden)

Mojtaba Ahmadi

2016-11-01

Full Text Available The aqueous degradation of Reactive Yellow 84 (RY84 by potassium peroxydisulfate (K2S2O8 has been studied in laboratory scale experiments. The effect of the initial concentrations of potassium peroxydisulfate and RY84, pH and temperature on RY84 degradation were also examined. Experimental data were analyzed using first and second-order kinetics. The degradation kinetics of RY84 of the potassium peroxydisulfate process followed the second-order reaction kinetics. These rate constants have an extreme values similar to of 9.493 mM−1min−1 at a peroxydisulfate dose of 4 mmol/L. Thermodynamic parameters such as activation (Ea and Gibbs free energy (ΔG° were also evaluated. The negative value of ΔGo and Ea shows the spontaneous reaction natural conditions and exothermic nature.

Unusual ISS Rate Signature

Science.gov (United States)

Laible, Michael R.

2011-01-01

On November 23, 2011 International Space Station Guidance, Navigation, and Control reported unusual pitch rate disturbance. These disturbances were an order of magnitude greater than nominal rates. The Loads and Dynamics team was asked to review and analyze current accelerometer data to investigate this disturbance. This paper will cover the investigation process under taken by the Loads and Dynamics group. It will detail the accelerometers used and analysis performed. The analysis included performing Frequency Fourier Transform of the data to identify the mode of interest. This frequency data is then reviewed with modal analysis of the ISS system model. Once this analysis is complete and the disturbance quantified, a forcing function was produced to replicate the disturbance. This allows the Loads and Dynamics team to report the load limit values for the 100's of interfaces on the ISS.

Detection of unusual events and trends in complex non-stationary data streams

International Nuclear Information System (INIS)

Charlton-Perez, C.; Perez, R.B.; Protopopescu, V.; Worley, B.A.

2011-01-01

The search for unusual events and trends hidden in multi-component, nonlinear, non-stationary, noisy signals is extremely important for diverse applications, ranging from power plant operation to homeland security. In the context of this work, we define an unusual event as a local signal disturbance and a trend as a continuous carrier of information added to and different from the underlying baseline dynamics. The goal of this paper is to investigate the feasibility of detecting hidden events inside intermittent signal data sets corrupted by high levels of noise, by using the Hilbert-Huang empirical mode decomposition method.

Na{sub 2}V{sub 3}O{sub 7}: An unusual low-dimensional quantum magnet

Energy Technology Data Exchange (ETDEWEB)

Gavilano, J.L. [Laboratorium fuer Festkoerperphysik, ETHZ, CH-8093 Zurich (Switzerland)]. E-mail: gavilano@phys.ethz.ch; Felder, E. [Laboratorium fuer Festkoerperphysik, ETHZ, CH-8093 Zurich (Switzerland); Rau, D. [Laboratorium fuer Festkoerperphysik, ETHZ, CH-8093 Zurich (Switzerland); Ott, H.R. [Laboratorium fuer Festkoerperphysik, ETHZ, CH-8093 Zurich (Switzerland); Millet, P. [Centre d' Elaboration des Materiaux et d' Etudes Structurales, 29, rue J. Marvig, 31055 Toulouse Cedex (France); Mila, F. [Institute of Theoretical Physics, EPFL, CH - 1015 Lausanne (Switzerland); Cichorek, T. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, 01187 Dresden (Germany); Mota, A.C. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, 01187 Dresden (Germany)

2006-05-01

Results of present and previous measurements of the {sup 23}Na NMR response, dc- and ac-magnetic susceptibilities and the specific heat of Na{sub 2}V{sub 3}O{sub 7} at low temperatures suggest that this material is close to a quantum critical point (QCP) at {mu}{sub 0}H=0T. The experimental data can be explained by assuming that below 100K the localized V magnetic moments (S=12) form a collection of dimers, with a broad distribution of singlet-triplet gaps. Most of the dimers adopt a singlet ground state with gaps between 0 and 350K. A small fraction of them forms triplet ground states with gaps between 0 and 15K. The degeneracy of the triplet ground states is lifted by a phase transition at an unusually low temperature of 0.086K. Modest magnetic fields effectively quench this low-temperature state and the system is driven away from the QCP as the applied fields are enhanced to above 1T.

KINETIC BEHAVIOR IN THE HYDROGENATION OF FURFURAL OVER IR CATALYSTS SUPPORTED ON TIO2

OpenAIRE

ROJAS, HUGO; MARTÍNEZ, JOSÉ J.; REYES, PATRICIO

2010-01-01

The kinetics of the liquid-phase hydrogenation of furfuraldehyde to furfuryl alcohol over Ir catalysts supported over TiO2 was studied in the temperature range of 323 to 373 K. The effect of furfural concentration, hydrogen pressure and the solvent effect were also studied. A high selectivity towards furfuryl alcohol was demonstrated. Initial rates describes the order global of the reaction. The experimental data could also be explained using the Langmuir-Hinshelwood model with of a single-si...

Kinetics of mutation induction by ultraviolet light in excision-deficient yeast.

Science.gov (United States)

Eckardt, F; Haynes, R H

1977-02-01

We have measured the frequency of UV-induced reversions (locus plus suppressor) for the ochre alleles ade2-1 and lys2-1 and forward mutations (ade2 adex double auxotrophs) in an excision-deficient strain of Saccharomyces cerevisiae (rad2-20). For very low UV doses, both mutational systems exhibit linear induction kinetics. However, as the dose increases, a strikingly different response is observed: in the selective reversion system a transition to higher order induction kinetics occurs near 9 ergs/mm2 (25% survival), whereas in the nonselective forward system the mutation frequency passes through a maximum near 14 ergs/mm2 (4.4% survival) and then declines. This contrast in kinetics cannot be explained in any straightforward way by current models of induced mutagenesis, which have been developed primarily on the basis of bacterial data. The bacterial models are designed to accommodate the quadratic induction kinetics that are frequently observed in these systems. We have derived a mathematical expression for mutation frequency that enables us to fit both the forward and reversion data on the assumptions that mutagenesis is basically a "single event" Poisson process, and that mutation and killing are not necessarily independent of one another. In particular, the dose-response relations are consistent with the idea that the sensitivity of the revertants is about 25% less than that of the original cell population, whereas the sensitivity of the forward mutants is about 29% greater than the population average. We argue that this relatively small differential sensitivity of mutant and nonmutant cells is associated with events that take place during mutation expression and clonal growth.

Kinetics of mutation induction by ultraviolet light in excision-deficient yeast

International Nuclear Information System (INIS)

Eckardt, F.; Haynes, R.H.

1977-01-01

We have measured the frequency of uv-induced reversions (locus plus suppressor) for the ochre alleles ade 2-1 and lys 2-1 and forward mutations (ade2 adex double auxotrophs) in an excision-deficient strain of Saccharomyces cerevisiae (rad 2-20). For very low uv doses, both mutational systems exhibit linear induction kinetics. However, as the dose increases, a strikingly different response is observed: in the selective reversion system a transition to higher order induction kinetics occurs near 9 ergs/mm 2 (25 percent survival), whereas in the nonselective forward system the mutation frequency passes through a maximum near 14 ergs/mm 2 (4.4 percent survival) and then declines. This contrast in kinetics cannot be explained in any straightforward way by current models of induced mutagenesis, which have been developed primarily on the basis of bacterial data. The bacterial models are designed to accommodate the quadratic induction kinetics that are frequently observed in these systems. We have derived a mathematical expression for mutation frequency that enables us to fit both the forward and reversion data on the assumptions that mutagenesis is basically a ''single event'' Poisson process, and that mutation and killing are not necessarily independent of one another. In particular, the dose-response relations are consistent with the idea that the sensitivity of the revertants is about 25 percent less than that of the original cell population, whereas the sensitivity of the forward mutants is about 29 percent greater than the population average. We argue that this relatively small differential sensitivity of mutant and nonmutant cells is associated with events that take place during mutation expression and clonal growth

EFFECTS OF SIMPLIFIED CHEMICAL KINETIC MODEL ON THE MICRO-FLAME STRUCTURE AND TEMPERATURE OF THE LEAN PREMIXED METHANE-AIR MIXTURES

Directory of Open Access Journals (Sweden)

JUNJIE CHEN

2015-07-01

Full Text Available The effect of simplified chemical kinetic model on the micro-flame structure, central axis and wall temperatures were investigated with different one-step global chemical kinetic mechanisms following Mantel, Duterque and Fernández-Tarrazo models. Numerical investigations of the premixed methane-air flame in the micro-channel and lean conditions were carried out to compare and analyze the effect of the comprehensive chemical kinetic mechanisms. The results indicate that one-step global chemical kinetic mechanism affects both the micro-flame shape and the combustion temperature. Among three simulation models, Mantel model allows a stable micro-flame with a bamboo shoot form, which anchor at the inlet. Duterque model gives a stable elongated micro-flame with a considerable ignition delay, and a dead zone with fluid accumulation is observed at the entrance, which may explain the very high combustion temperature and the fast reaction rate obtained, despite the micro-flame development presents a very hot spot and causes a broadening of the combustion zone. Fernández-Tarrazo model results in a rapid extinction and doesn't seem to take all the kinetic behavior into account for the appropriate micro-combustion simulations.

A Case of Unusual Clitoromegaly.

Science.gov (United States)

Wooi Ch'ng, Tong; Umpaichitra, Vatcharapan

2018-05-03

Mild degree of clitoromegaly can be associated with patient with polycystic ovarian syndrome (PCOS). We describe an unusually significant clitoromegaly in a patient with PCOS. An 18-year old non-obese female referred for clitoromegaly. Her genitalia exam showed significant clitoral enlargement with a well-formed glans, clitoris measured at 35 mm for length and 10 mm for width. Pelvic ultrasound showed left ovarian cyst. Testosterone level ranged from 28.8 to 64.1 ng/dl (normal: 8.4-48.1 ng/dl) with normal sex hormone binding globulin. Other ovarian hormones were in acceptable ranges. This case demonstrates the coexistence of significant clitoromegaly, PCOS, and non-functioning ovarian cyst. Copyright © 2018. Published by Elsevier Inc.

Ruptured rectal duplication with urogenital abnormality: Unusual presentation

Directory of Open Access Journals (Sweden)

Shailesh Solanki

2015-01-01

Full Text Available Rectal duplication (RD accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD.

Unusual causes of acute abdomen in a Nigerian hospital ...

African Journals Online (AJOL)

Acute abdomen is the most common abdominal emergency associated with high morbidity and mortality in General surgical practice. Over a 7-year period, a study of unusual causes of acute abdomen was undertaken, with the aim of identifying these causes and outcome of operative management. Eleven cases were ...

41 CFR 101-39.206 - Seasonal or unusual requirements.

Science.gov (United States)

2010-07-01

... VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.2-GSA Interagency Fleet Management System Services... requirements for vehicles or related services shall inform the GSA IFMS fleet management center as far in... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Seasonal or unusual...

Slow VO2 off-kinetics in skeletal muscle is associated with fast PCr off-kinetics--and inversely.

Science.gov (United States)

Korzeniewski, Bernard; Zoladz, Jerzy A

2013-09-01

The computer model of the bioenergetic system in skeletal muscle, developed previously, was used to study the effect of the characteristic decay time of the parallel activation of oxidative phosphorylation [τ(OFF)] during muscle recovery on the muscle oxygen consumption rate (Vo2) and phosphocreatine (PCr) work-to-rest transition (off)-kinetics and on the relationship between the Vo2 and PCr rest-to-work transition (on)- and off-kinetics in moderate and heavy exercise. An increase in τ(OFF) slows down the initial phase of the muscle Vo2 off-kinetics and accelerates the PCr off-kinetics. As a result, the relationship between the initial phase of the Vo2 off-kinetics (lasting approximately 3-60 s in computer simulations) and the PCr off-kinetics is inverse: the slower the former, the faster the latter. A faster initial phase of the Vo2 off-kinetics is associated with a slower late phase of the Vo2 off-kinetics, and as a result, the integral of Vo2 above baseline during recovery, representing the oxygen debt, is identical in all cases [values of τ(OFF)] for a given PCr decrease. Depending on τ(OFF), the muscle Vo2 on-kinetics was either equally fast or slower than the Vo2 off-kinetics in moderate exercise and always slower in heavy exercise. PCr on-kinetics was always faster than PCr off-kinetics. This study clearly demonstrates that τ(OFF) has a pronounced impact on the mutual relations between the muscle Vo2 and PCr on- and off-kinetics.

Holographic kinetic k-essence model

Energy Technology Data Exchange (ETDEWEB)

Cruz, Norman [Departamento de Fisica, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: ncruz@lauca.usach.cl; Gonzalez-Diaz, Pedro F.; Rozas-Fernandez, Alberto [Colina de los Chopos, Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)], E-mail: a.rozas@cfmac.csic.es; Sanchez, Guillermo [Departamento de Matematica y Ciencia de la Computacion, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: gsanchez@usach.cl

2009-08-31

We consider a connection between the holographic dark energy density and the kinetic k-essence energy density in a flat FRW universe. With the choice c{>=}1, the holographic dark energy can be described by a kinetic k-essence scalar field in a certain way. In this Letter we show this kinetic k-essential description of the holographic dark energy with c{>=}1 and reconstruct the kinetic k-essence function F(X)

Osmosis and thermodynamics explained by solute blocking.

Science.gov (United States)

Nelson, Peter Hugo

2017-01-01

A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.

Osmosis and thermodynamics explained by solute blocking

Science.gov (United States)

Nelson, Peter Hugo

2016-01-01

A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult’s law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed, others can be tested experimentally or by simulation. PMID:27225298

An Unusual Laryngeal Foreign Body in Adult.

Science.gov (United States)

Ndiaye, Cire; Regonne, Eric Joel; Ahmed, Houra; Diom, Evelyne Siga; Deguenonvo, Richard Edouard Alain; Mbaye, Aminata; Zemene, Yilkal; Ndiaye, Issa Cheikh

2016-01-01

The accidental aspiration of a foreign body is a frequent domestic accident among children but a rare occurrence in adults. The laryngeal impaction of a coin is an unusual accident; only a few cases have been reported in the literature. Diagnosis is mostly achieved by clinicoradiological examinations. The authors report an uncommon case of laryngeal impaction of a coin in a 21-year-old patient, presenting with dysphonia without dyspnea or stridor. The extraction was performed by endoscopy.

An Unusual Laryngeal Foreign Body in Adult

OpenAIRE

Ndiaye, Cire; Regonne, Eric Joel; Ahmed, Houra; Diom, Evelyne Siga; Deguenonvo, Richard Edouard Alain; Mbaye, Aminata; Zemene, Yilkal; Ndiaye, Issa Cheikh

2016-01-01

The accidental aspiration of a foreign body is a frequent domestic accident among children but a rare occurrence in adults. The laryngeal impaction of a coin is an unusual accident; only a few cases have been reported in the literature. Diagnosis is mostly achieved by clinicoradiological examinations. The authors report an uncommon case of laryngeal impaction of a coin in a 21-year-old patient, presenting with dysphonia without dyspnea or stridor. The extraction was performed by endoscopy.

Kinetic model of water disinfection using peracetic acid including synergistic effects.

Science.gov (United States)

Flores, Marina J; Brandi, Rodolfo J; Cassano, Alberto E; Labas, Marisol D

2016-01-01

The disinfection efficiencies of a commercial mixture of peracetic acid against Escherichia coli were studied in laboratory scale experiments. The joint and separate action of two disinfectant agents, hydrogen peroxide and peracetic acid, were evaluated in order to observe synergistic effects. A kinetic model for each component of the mixture and for the commercial mixture was proposed. Through simple mathematical equations, the model describes different stages of attack by disinfectants during the inactivation process. Based on the experiments and the kinetic parameters obtained, it could be established that the efficiency of hydrogen peroxide was much lower than that of peracetic acid alone. However, the contribution of hydrogen peroxide was very important in the commercial mixture. It should be noted that this improvement occurred only after peracetic acid had initiated the attack on the cell. This synergistic effect was successfully explained by the proposed scheme and was verified by experimental results. Besides providing a clearer mechanistic understanding of water disinfection, such models may improve our ability to design reactors.

Reflected kinetics model for nuclear space reactor kinetics and control scoping calculations

Energy Technology Data Exchange (ETDEWEB)

Washington, K.E.

1986-05-01

The objective of this research is to develop a model that offers an alternative to the point kinetics (PK) modelling approach in the analysis of space reactor kinetics and control studies. Modelling effort will focus on the explicit treatment of control drums as reactivity input devices so that the transition to automatic control can be smoothly done. The proposed model is developed for the specific integration of automatic control and the solution of the servo mechanism problem. The integration of the kinetics model with an automatic controller will provide a useful tool for performing space reactor scoping studies for different designs and configurations. Such a tool should prove to be invaluable in the design phase of a space nuclear system from the point of view of kinetics and control limitations.

Reflected kinetics model for nuclear space reactor kinetics and control scoping calculations

International Nuclear Information System (INIS)

Washington, K.E.

1986-05-01

The objective of this research is to develop a model that offers an alternative to the point kinetics (PK) modelling approach in the analysis of space reactor kinetics and control studies. Modelling effort will focus on the explicit treatment of control drums as reactivity input devices so that the transition to automatic control can be smoothly done. The proposed model is developed for the specific integration of automatic control and the solution of the servo mechanism problem. The integration of the kinetics model with an automatic controller will provide a useful tool for performing space reactor scoping studies for different designs and configurations. Such a tool should prove to be invaluable in the design phase of a space nuclear system from the point of view of kinetics and control limitations

LLNL Chemical Kinetics Modeling Group

Energy Technology Data Exchange (ETDEWEB)

Pitz, W J; Westbrook, C K; Mehl, M; Herbinet, O; Curran, H J; Silke, E J

2008-09-24

The LLNL chemical kinetics modeling group has been responsible for much progress in the development of chemical kinetic models for practical fuels. The group began its work in the early 1970s, developing chemical kinetic models for methane, ethane, ethanol and halogenated inhibitors. Most recently, it has been developing chemical kinetic models for large n-alkanes, cycloalkanes, hexenes, and large methyl esters. These component models are needed to represent gasoline, diesel, jet, and oil-sand-derived fuels.

Case series of unusual causes intestinal obstruction in infants and ...

African Journals Online (AJOL)

Introduction Many of the causes of intestinal obstruction arise from ... In this work, we report eight unusual cases of intestinal ..... lymph is considered to be the result of an imbalance ... During fetal life, midgut communicates with the yolk sac.

Oral malignant melanoma: a rare case with unusual clinical ...

African Journals Online (AJOL)

Primary Oral malignant melanoma is a rare tumor with an indigent prognosis. This is a case report of 47-year-old Sudanese female diagnosed as Oral malignant melanoma of the mandible with an unusual pattern of growth and clinical presentation. Furthermore, a possibility of intraosseous origin is suggested. Pan African ...

Gyrocenter-gauge kinetic theory

International Nuclear Information System (INIS)

Qin, H.; Tang, W.M.; Lee, W.W.

2000-01-01

Gyrocenter-gauge kinetic theory is developed as an extension of the existing gyrokinetic theories. In essence, the formalism introduced here is a kinetic description of magnetized plasmas in the gyrocenter coordinates which is fully equivalent to the Vlasov-Maxwell system in the particle coordinates. In particular, provided the gyroradius is smaller than the scale-length of the magnetic field, it can treat high frequency range as well as the usual low frequency range normally associated with gyrokinetic approaches. A significant advantage of this formalism is that it enables the direct particle-in-cell simulations of compressional Alfven waves for MHD applications and of RF waves relevant to plasma heating in space and laboratory plasmas. The gyrocenter-gauge kinetic susceptibility for arbitrary wavelength and arbitrary frequency electromagnetic perturbations in a homogeneous magnetized plasma is shown to recover exactly the classical result obtained by integrating the Vlasov-Maxwell system in the particle coordinates. This demonstrates that all the waves supported by the Vlasov-Maxwell system can be studied using the gyrocenter-gauge kinetic model in the gyrocenter coordinates. This theoretical approach is so named to distinguish it from the existing gyrokinetic theory, which has been successfully developed and applied to many important low-frequency and long parallel wavelength problems, where the conventional meaning of gyrokinetic has been standardized. Besides the usual gyrokinetic distribution function, the gyrocenter-gauge kinetic theory emphasizes as well the gyrocenter-gauge distribution function, which sometimes contains all the physics of the problems being studied, and whose importance has not been realized previously. The gyrocenter-gauge distribution function enters Maxwell's equations through the pull-back transformation of the gyrocenter transformation, which depends on the perturbed fields. The efficacy of the gyrocenter-gauge kinetic approach is

Plagiarism explainer for students

OpenAIRE

Barba, Lorena A.

2016-01-01

A slide deck to serve as an explainer of plagiarism in academic settings, with a personal viewpoint. For my students.Also on SpeakerDeck:https://speakerdeck.com/labarba/plagiarism-explainer-for-students(The slide viewer on SpeakerDeck is much nicer.)

Cardiopulmonary Resuscitation: Unusual Techniques for Unusual Situations

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Vidhu Bhatnagar

2018-01-01

Full Text Available Background: The cardiopulmonary resuscitation (CPR in prone position has been dealt with in 2010 American Heart Association (AHA guidelines but have not been reviewed in 2015 guidelines. The guidelines for patients presenting with cardiac arrest under general anesthesia in lateral decubitus position and regarding resuscitation in confined spaces like airplanes are also not available in AHA guidelines. This article is an attempt to highlight the techniques adopted for resuscitation in these unusual situations. Aims: This study aims to find out the methodology and efficacy in nonconventional CPR approaches such as CPR in prone, CPR in lateral position, and CPR in confined spaces. Methods: We conducted a literature search using MeSH search strings such as CPR + Prone position, CPR + lateral Position, and CPR + confined spaces. Results: No randomized controlled trials are available. The literature search gives a handful of case reports, some simulation- and manikin-based studies but none can qualify for class I evidence. The successful outcome of CPR performed in prone position has shown compressions delivered on the thoracic spine with the same rate and force as they were delivered during supine position. A hard surface is required under the patient to provide uniform force and sternal counter pressure. Two rescuer technique for providing successful chest compression in lateral position has been documented in the few case reports published. Over the head CPR and straddle (STR, CPR has been utilized for CPR in confined spaces. Ventilation in operating rooms was taken care by an advanced airway in situ. Conclusion: A large number of studies of high quality are required to be conducted to determine the efficacy of CPR in such positions.

Static and kinetic frictional forces of silica-insert ceramic brackets with coated archwires in artificial saliva.

Science.gov (United States)

Shahabi, Mostafa; Salari, Soheil; Poosti, Maryam; Abtahi, Mostafa

2017-01-01

During sliding mechanics, the frictional force (FF) is an important counterforce to orthodontic tooth movement. The purpose of this in vitro study was to investigate the static and kinetic FFs of S silica-insert ceramic (SIC) brackets with Teflon-coated (TC) and conventional S stainless steel (SS) archwires. The target group of this study included 80 maxillary canine 0.022 inch slot SIC brackets. Forty SS brackets were used as the control. TC and conventional uncoated SS archwires of different dimensions (0.016, 0.018, 0.016 × 0.022, and 0.018 × 0.025 inch) were examined. All tests were carried out under artificial saliva injected condition. Scanning Electron Micrographs were prepared for two samples of coated and uncoated archwires. Analysis of variance and Tukey post hoc tests were used for statistical purposes (level of significance P brackets showed significantly lower levels of FFs than SS brackets. TC archwires had greater frictional values than conventional uncoated ones. They also exhibited an unusual behavior of increasing kinetic FFs with time. Indentation and delamination of coating were obvious under scanning electron microscopy observations. From the standpoint of friction, SIC brackets may serve well, even better than SS brackets, in sliding mechanics. The coating layer of the archwires may delaminate and lost, causing an impediment to tooth movement.

The kinetics of formation and transformation of silver atoms on solid surfaces subjected to ionizing irradiation

International Nuclear Information System (INIS)

Popovich, G.M.

1988-01-01

The paper discusses the results obtained in ESR-assisted studies of the kinetics of formation and transformation of silver atoms generated by γ-irradiation of silver-containing carriers. Three types of dependences have been established: (1) extreme; (2) saturation curves and (3) step-like. All the kinetic curves display, after a definite period of time, stable concentrations of adsorbed silver atoms per unit of the surface at a given temperature. Depending on the temperature of the experiment, the composition and nature of the carrier, the number of adsorbed silver ions, the irradiation dose and conditions of the experiment, a stable concentration of silver atoms at a given temperature may be equal to, higher or lower than the number of silver atoms measured immediately after γ-irradiation at a temperature of liquid nitrogen. A kinetic scheme is proposed to explain the obtained curves. The model suggests that the silver atoms adsorbed on the surface, as well as those formed after γ-irradiation, are bonded to the surface by various energies, which are related to heterogeneity of the carrier surface. (author)

Unusual Cases of Hypothenar Hammer Syndrome.

Science.gov (United States)

Orrapin, Saranat; Arworn, Supapong; Wisetborisut, Anawat

2015-01-01

Hypothenar hammer syndrome (HHS) is a rare occupational disease. The risk group of HHS is patient whose dominate hand used as a hammer. Our study report unusually cases in Chiang Mai University Hospital. 19 year-old basketball player had right ulnar artery aneurysm for two months. After operation, his symptom was relieved and returned to play basketball again. 65 year-old housekeeper had non-dominated hand ulnar artery aneurysm for two years. After operation she still had hand claudication due to poor run-off vessel. HHS is previously state in risk group. But from our report there was a risk in different occupation.

An Unusual Case of Gastrointestinal Bleeding

Directory of Open Access Journals (Sweden)

Kristin N. Fiorino

2011-01-01

Full Text Available A 10-year-old boy presented with a 3-day history of worsening abdominal pain, fever, emesis and melena. Abdominal ultrasound revealed a right upper quadrant mass that was confirmed by computed tomography angiogram (CTA, which showed an 8 cm well-defined retroperitoneal vascular mass. 123Iodine metaiodobenzylguanidine (123MIBG scan indicated uptake only in the abdominal mass. Subsequent biopsy revealed a paraganglioma that was treated with chemotherapy. This case represents an unusual presentation of a paraganglioma associated with gastrointestinal (GI bleeding and highlights the utility of CTA and 123MIBG in evaluation and treatment.

An unusually strong Einstein ring in the radio source PKS1830-211

International Nuclear Information System (INIS)

Jauncey, D.L.

1991-01-01

RADIO observations of the strong, flat-spectrum radio source PKS1830-211 revealed a double structure, with a separation of 1 arcsec, suggesting that it might be a gravitationally lensed object. We have now obtained high-resolution radio images of PKS1830-211 from several interferometric radiotelescope networks, which show an unusual elliptical ring-like structure connecting the two brighter components. The presence of the ring, and the similarity of the two brighter spots, argue strongly that this is indeed a gravitationally lensed system, specifically an Einstein ring in which lens and lensed object are closely aligned. Although the source is close to the galactic plane, it seems that both the lens and background (lensed) object are extragalactic. This object is one hundred times brighter than either of the two previously discovered radio Einstein rings, and is among the six brightest flat-spectrum sources in the sky. Its brightness makes it a peculiar object: it must involve either a chance alignment of a lensing object with an unusually bright background source, or an alignment with a less bright object but amplified to an unusual degree. (author)

A link between lead and cadmium kinetic speciation in seawater and accumulation by the green alga Ulva lactuca

International Nuclear Information System (INIS)

Muse, J.O.; Carducci, C.N.; Stripeikis, J.D.; Tudino, M.B.; Fernandez, F.M.

2006-01-01

In this work, studies on the bioaccumulation of Cd and Pb by Ulva lactuca at different sites of Gulf San Jorge (Patagonia, Argentina) are presented. Higher values of bioaccumulated Cd were found in Punta Maqueda - a site believed to serve as a control - in comparison to those in Punta Borja, a place highly exposed to urban and industrial activities. Consequently; the labile fractions of Cd and Pb in seawater were determined with a flow injection-preconcentration manifold interfaced to a graphite furnace-atomic absorption spectrometer (FI-GFAAS). The results obtained by kinetic speciation showed that the variable that correctly explains heavy metals accumulation in the alga, is the labile metal fraction in seawater. We propose to use an enhancement ratio - on the basis of the kinetically labile metal fraction - for calculation of the metal accumulated by the alga relative to its environment. - Metal kinetic speciation can overcome CF limitations for the evaluation of marine pollution

Application of a two-region kinetic model for reflected reactors to experimental data

International Nuclear Information System (INIS)

Busch, R.D.; Spriggs, G.D.; Williams, J.G.

1996-01-01

Reflected reactors constitute one of the most important classes of nuclear reactors. Yet, during the past 50 yr, a plethora of experimental data involving reflected systems has been reported in the literature that cannot be satisfactorily explained using the open-quotes standardclose quotes (i.e., one-region) point-kinetic model. In particular, many have observed that the prompt-decay a curves obtained from Rossi-α and pulsed-neutron experiments can exhibit multiple decay modes in the vicinity near delayed critical in some types of reflected systems. When analyzed using theories based on the standard point-kinetic model, these data yielded system lifetimes that do not always agree well with the lifetimes predicted by numerical solutions of the multigroup, multidimensional diffusion or transport equations. In several cases, when the longest lived decay mode (i.e., the dominant root) was plotted as a function of reactivity, the a curve intercepted the reactivity axis at a reactivity significantly greater than 1$. Brunson dubbed this seemingly inexplicable behavior as the open-quotes dollar discrepancy.close quotes Furthermore, it has also been observed that the kinetic behavior of some reflected, fast-burst assemblies exhibits a very pronounced nonlinear relationship between reactivity and the initial inverse period for reactivity insertions > 1 $

Transparent control of three-body selective destruction of tunneling via unusual states

International Nuclear Information System (INIS)

Luo, Yunrong; Tan, Jintao; Hai, Wenhua; Lu, Gengbiao

2015-01-01

We study transparent control of quantum tunneling via unusual analytical solutions for three bosons held in a driven double-well. Under high-frequency approximation, we analytically obtain the fine band structure and general non-Floquet state. At some collapse points of the quasi-energy spectra, the latter becomes the unusual special states. Based on the analytical results and their numerical correspondences, we clearly reveal the mechanism of coherent tunneling and suggest a scheme to transparently control the tunneling of three bosons from one well to another. The results can be observed with the current experimental capability (Chen et al 2011 Phys. Rev. Lett. 107 210405) (paper)

Evidences for the Formation of Chromium in the Unusual Oxidation State Cr(IV). I. Chemical Reactivity, Microhomogeneity, and Crystal Structures of the Nonstoichiometric Channel Compounds Tl xCr 5Se 8(0 ≤ x≤ 1)

Science.gov (United States)

Bensch, W.; Helmer, O.; Näther, C.

1996-11-01

The topotactic redox reaction between TlCr 5Se 8and bromine in acetonitrile leads to the formation of metastable samples with 0 ≤ xtransition metal chalcogenide crystallizing in the TlV 5S 8type structure with a Tl content xtopotactic redox reaction does not follow simple kinetics but is rather explained on the basis of the superposition of at least three different fundamental steps. EDAX investigations conducted on selected single crystals reveal that dependent on the deintercalation temperature, Tl is laterally inhomogeneous distributed along the needle axis which coincides with the crystallographic baxis. A pronounced maximum is observed at the middle of the crystals. In stoichiometric TlCr 5Se 8the detailed analysis of the anisotropic displacement parameters of the Tl atoms reveal that the Tl atoms are displaced from the central position by about 0.26 Å. As a consequence the Tl atoms are coordinated by seven Se atoms in an irregular coordination polyhedron. Since the positions x0 zare related by a center of symmetry they cannot be occupied simultaneously. Hence it must be assumed that TlCr 5Se 8has a domain structure with local symmetry Cm. In the Tl poorer phases the refinement of the Tl atoms at the central position leads to unusual high U22components. The observed microinhomogenity as well as an enhanced mobility and/or static disorder of the Tl atom within the channel may be responsible for this. The value for U11decreases with decreasing Tl content whereas U33is not affected. This observation is indicative for a different displacement of the Tl atoms from the central position. With respect to the possible reaction mechanisms, according to our structural investigations, the oxidation of monovalent Tl to trivalent Tl can be excluded. With decreasing Tl content the lattice parameters exhibit very anisotropic behavior, which is a direct consequence of the large changes of the interatomic Cr-Cr distances. The average as well as the nonbonding Se-Se distances

Unusual migration of ventriculo peritoneal distal catheter into vagina

Directory of Open Access Journals (Sweden)

Sghavamedin Tavallaee

2015-04-01

Full Text Available VP shunt is one of the most popular methods for ICP reduction and treatment of hydrocephalus. Various complications of this method are not uncommon such as shunt malfunction, infection and unusual migration of distal catheter. I present a case of migration of the peritoneal catheter out of the vagina.

Kinetic memory based on the enzyme-limited competition.

Science.gov (United States)

Hatakeyama, Tetsuhiro S; Kaneko, Kunihiko

2014-08-01

Cellular memory, which allows cells to retain information from their environment, is important for a variety of cellular functions, such as adaptation to external stimuli, cell differentiation, and synaptic plasticity. Although posttranslational modifications have received much attention as a source of cellular memory, the mechanisms directing such alterations have not been fully uncovered. It may be possible to embed memory in multiple stable states in dynamical systems governing modifications. However, several experiments on modifications of proteins suggest long-term relaxation depending on experienced external conditions, without explicit switches over multi-stable states. As an alternative to a multistability memory scheme, we propose "kinetic memory" for epigenetic cellular memory, in which memory is stored as a slow-relaxation process far from a stable fixed state. Information from previous environmental exposure is retained as the long-term maintenance of a cellular state, rather than switches over fixed states. To demonstrate this kinetic memory, we study several models in which multimeric proteins undergo catalytic modifications (e.g., phosphorylation and methylation), and find that a slow relaxation process of the modification state, logarithmic in time, appears when the concentration of a catalyst (enzyme) involved in the modification reactions is lower than that of the substrates. Sharp transitions from a normal fast-relaxation phase into this slow-relaxation phase are revealed, and explained by enzyme-limited competition among modification reactions. The slow-relaxation process is confirmed by simulations of several models of catalytic reactions of protein modifications, and it enables the memorization of external stimuli, as its time course depends crucially on the history of the stimuli. This kinetic memory provides novel insight into a broad class of cellular memory and functions. In particular, applications for long-term potentiation are discussed

Large Penile Mass With Unusual Benign Histopathology

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Nate Johnson

2015-09-01

Full Text Available Pseudoepitheliomatous hyperplasia is an extremely rare condition presenting as a lesion on the glans penis in older men. Physical exam without biopsy cannot differentiate malignant from nonmalignant growth. We report a case of large penile mass in an elderly male with a history of lichen sclerosis, highly suspicious for malignancy. Subsequent surgical removal and biopsy demonstrated pseudoepitheliomatous hyperplasia, an unusual benign histopathologic diagnosis with unclear prognosis. We review the literature and discuss options for treatment and surveillance.

An Unusual Laryngeal Foreign Body in Adult

Directory of Open Access Journals (Sweden)

Cire Ndiaye

2016-01-01

Full Text Available The accidental aspiration of a foreign body is a frequent domestic accident among children but a rare occurrence in adults. The laryngeal impaction of a coin is an unusual accident; only a few cases have been reported in the literature. Diagnosis is mostly achieved by clinicoradiological examinations. The authors report an uncommon case of laryngeal impaction of a coin in a 21-year-old patient, presenting with dysphonia without dyspnea or stridor. The extraction was performed by endoscopy.

Kinetics and hybrid kinetic-fluid models for nonequilibrium gas and plasmas

International Nuclear Information System (INIS)

Crouseilles, N.

2004-12-01

For a few decades, the application of the physics of plasmas has appeared in different fields like laser-matter interaction, astrophysics or thermonuclear fusion. In this thesis, we are interested in the modeling and the numerical study of nonequilibrium gas and plasmas. To describe such systems, two ways are usually used: the fluid description and the kinetic description. When we study a nonequilibrium system, fluid models are not sufficient and a kinetic description have to be used. However, solving a kinetic model requires the discretization of a large number of variables, which is quite expensive from a numerical point of view. The aim of this work is to propose a hybrid kinetic-fluid model thanks to a domain decomposition method in the velocity space. The derivation of the hybrid model is done in two different contexts: the rarefied gas context and the more complicated plasmas context. The derivation partly relies on Levermore's entropy minimization approach. The so-obtained model is then discretized and validated on various numerical test cases. In a second stage, a numerical study of a fully kinetic model is presented. A collisional plasma constituted of electrons and ions is considered through the Vlasov-Poisson-Fokker-Planck-Landau equation. Then, a numerical scheme which preserves total mass and total energy is presented. This discretization permits in particular a numerical study of the Landau damping. (author)

Attitudes Vs. Cognitions: Explaining Long-Term Watergate Effects.

Science.gov (United States)

Becker, Lee B.; Towers, Wayne M.

The political scandals known as Watergate provided an unusual opportunity to study the importance of attitudinal and cognitive variables in media research. In order to assess the impact of Watergate during the months preceding the 1974 Congressional elections, 339 personal interviews were conducted during October with a probability sample of…

Tantalum high-temperature oxidation kinetics

International Nuclear Information System (INIS)

Grigor'ev, Yu.M.; Sarkisyan, A.A.; Merzhanov, A.G.

1981-01-01

Kinetics of heat release and scale growth during tantalum oxidation within 650-1300 deg C temperature range in oxygen-containing media is investigated. Kinetic equations and temperature and pressure dependences of constants are ound Applicability of the kinetic Lorie mechanism for the description of the tantalum oxidation kinetics applicably to rapid-passing processes is shown. It is stated that the process rate (reaction ability) is determined by adsorption desorption factors on the external surface of the ''protective'' oxide for the ''linear'' oxidation stage [ru

Complexity explained

CERN Document Server

Erdi, Peter

2008-01-01

This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

Understanding the Unusual 2017 Monsoon and Floods in South Asia

Science.gov (United States)

Akanda, A. S.; Palash, W.; Hasan, M. A.; Nusrat, F.

2017-12-01

Driven primarily by the South Asian Monsoon, the Ganges-Brahmaputra-Meghna (GBM) river basin system collectively drains intense precipitation for an area of more than 1.5 million square kilometers during the wet summer season. Bangladesh, being the lowest riparian country in the system, experiences recurrent floods and immense suffering to its population. The 2017 monsoon season was quite unusual in terms of the characteristics of the precipitation received in the basin. The monsoon was spread out over a much larger time span (April-October) compared to the average monsoon season (June-September). Although the monsoon does not typically start until June in Bangladesh, the 2017 season started much earlier in April with unusually heavy precipitation in the Meghna basin region and caused major damage to agriculture in northeastern Bangladesh. The rainfall continued in several record-breaking pulses, compared to the typical one or two large waves. One of the largest pulses occurred in early August with very high in intensity and volume, causing ECMWF to issue a major warning about widespread flooding in Bangladesh, Northern India, and Eastern Nepal. This record flood event impacted over 40 million people in the above regions, causing major damage to life and infrastructure. Although the Brahmaputra rose above the danger level several times this season, the Ganges was unusually low, thus sparing downstream areas from disastrous floods. However, heavy precipitation continued until October, causing urban flooding in Dhaka and Chittagong - and worsening sanitation and public health conditions in southern Bangladesh - currently undergoing a terrible humanitarian crisis involving Rohingya refugees from the Myanmar. Despite marked improvement in flood forecasting systems in recent years, the 2017 floods identified critical gaps in our understanding of the flooding phenomena and limitations of dissemination in these regions. In this study, we investigate 1) the unusual

Vaginal haemangioendothelioma: an unusual tumour.

LENUS (Irish Health Repository)

Mohan, H

2012-02-01

Vaginal tumours are uncommon and this is a particularly rare case of a vaginal haemangioendothelioma in a 38-year-old woman. Initial presentation consisted of symptoms similar to uterovaginal prolapse with "something coming down". Examination under anaesthesia demonstrated a necrotic anterior vaginal wall tumour. Histology of the lesion revealed a haemangioendothelioma which had some features of haemangiopericytoma. While the natural history of vaginal haemangioendothelioma is uncertain, as a group, they have a propensity for local recurrence. To our knowledge this is the third reported case of a vaginal haemangioendothelioma. Management of this tumour is challenging given the paucity of literature on this tumour. There is a need to add rare tumours to our "knowledge bank" to guide management of these unusual tumours.

Unusual clinical manifestations of leptospirosis

Directory of Open Access Journals (Sweden)

Bal A

2005-01-01

Full Text Available Leptospirosis has protean clinical manifestations. The classical presentation of the disease is an acute biphasic febrile illness with or without jaundice. Unusual clinical manifestations may result from involvement of pulmonary, cardiovascular, neural, gastrointestinal, ocular and other systems. Immunological phenomena secondary to antigenic mimicry may also be an important component of many clinical features and may be responsible for reactive arthritis. Leptospirosis in early pregnancy may lead to fetal loss. There are a few reports of leptospirosis in HIV- infected individuals but no generalisation can be made due to paucity of data. It is important to bear in mind that leptospiral illness may be a significant component in cases of dual infections or in simultaneous infections with more than two pathogens.

An unusual cosmological solution in the context of higher-derivative gravity

International Nuclear Information System (INIS)

Accioly, A.J.

1988-01-01

A general vacuum solution to the higher-derivative gravity field equations is presented in case of a model that exhibits symmetries of the Goedel-type. The solution possesses unusual properties. (author) [pt

Muscular Oxygen Uptake Kinetics in Aged Adults.

Science.gov (United States)

Koschate, J; Drescher, U; Baum, K; Eichberg, S; Schiffer, T; Latsch, J; Brixius, K; Hoffmann, U

2016-06-01

Pulmonary oxygen uptake (V˙O2) kinetics and heart rate kinetics are influenced by age and fitness. Muscular V˙O2 kinetics can be estimated from heart rate and pulmonary V˙O2. In this study the applicability of a test using pseudo-random binary sequences in combination with a model to estimate muscular V˙O2 kinetics was tested. Muscular V˙O2 kinetics were expected to be faster than pulmonary V˙O2 kinetics, slowed in aged subjects and correlated with maximum V˙O2 and heart rate kinetics. 27 elderly subjects (73±3 years; 81.1±8.2 kg; 175±4.7 cm) participated. Cardiorespiratory kinetics were assessed using the maximum of cross-correlation functions, higher maxima implying faster kinetics. Muscular V˙O2 kinetics were faster than pulmonary V˙O2 kinetics (0.31±0.1 vs. 0.29±0.1 s; p=0.004). Heart rate kinetics were not correlated with muscular or pulmonary V˙O2 kinetics or maximum V˙O2. Muscular V˙O2 kinetics correlated with maximum V˙O2 (r=0.35; p=0.033). This suggests, that muscular V˙O2 kinetics are faster than estimates from pulmonary V˙O2 and related to maximum V˙O2 in aged subjects. In the future this experimental approach may help to characterize alterations in muscular V˙O2 under various conditions independent of motivation and maximal effort. © Georg Thieme Verlag KG Stuttgart · New York.

Scientific Letter: Stabbing nails into the neck: an unusual self ...

African Journals Online (AJOL)

Scientific Letter: Stabbing nails into the neck: an unusual self-damaging behavior mandating neurosurgery. A Aghabiklooei, R Aghabiklooei, N Zamani. Abstract. Scientific Letter - No Abstract Available. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase*

Science.gov (United States)

Mishanina, Tatiana V.; Yadav, Pramod K.; Ballou, David P.; Banerjee, Ruma

2015-01-01

The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be −123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. PMID:26318450

Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase.

Science.gov (United States)

Mishanina, Tatiana V; Yadav, Pramod K; Ballou, David P; Banerjee, Ruma

2015-10-09

The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be -123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

The wireless internet explained

CERN Document Server

Rhoton, John

2001-01-01

The Wireless Internet Explained covers the full spectrum of wireless technologies from a wide range of vendors, including initiatives by Microsoft and Compaq. The Wireless Internet Explained takes a practical look at wireless technology. Rhoton explains the concepts behind the physics, and provides an overview that clarifies the convoluted set of standards heaped together under the umbrella of wireless. It then expands on these technical foundations to give a panorama of the increasingly crowded landscape of wireless product offerings. When it comes to actual implementation the book gives abundant down-to-earth advice on topics ranging from the selection and deployment of mobile devices to the extremely sensitive subject of security.Written by an expert on Internet messaging, the author of Digital Press''s successful Programmer''s Guide to Internet Mail and X.400 and SMTP: Battle of the E-mail Protocols, The Wireless Internet Explained describes and evaluates the current state of the fast-growing and crucial...

Kinetic analysis on photocatalytic degradation of gaseous acetaldehyde, ammonia and hydrogen sulfide on nanosized porous TiO2 films

Directory of Open Access Journals (Sweden)

Iis Sopyan

2007-01-01

Full Text Available The characteristics of the UV illumination-assisted degradation of gaseous acetaldehyde, hydrogen sulfide, and ammonia on highly active nanostructured-anatase and rutile films were investigated. It was found that the anatase film showed a higher photocatalytic activity than the counterpart did, however, the magnitude of difference in the photocatalytic activity of both films decreased in the order ammonia>acetaldehyde>hydrogen sulfide. To elucidate the reasons for the observation, the adsorption characteristics and the kinetics of photocatalytic degradation of the three reactants on both films were analyzed. The adsorption analysis examined using a simple Langmuir isotherm, showed that adsorbability on both films decreased in the order ammonia>acetaldehyde>hydrogen sulfide, which can be explained in terms of the decreasing electron-donor capacity. Acetaldehyde and ammonia adsorbed more strongly and with higher coverage on anatase film (1.2 and 5.6 molecules/nm2, respectively than on rutile (0.6 and 4.7 molecules/nm2, respectively. Conversely, hydrogen sulfide molecules adsorbed more strongly on rutile film (0.7 molecules/nm2 than on anatase (0.4 molecules/nm2. Exposure to UV light illumination brought about the photocatalytic oxidation of the three gases in contact with both TiO2 films, and the decrease in concentration were measured, and their kinetics are analyzed in terms of the Langmuir–Hinshelwood kinetic model. From the kinetic analysis, it was found that the anatase film showed the photocatalytic activities that were factors of ~8 and ~5 higher than the rutile film for the degradation of gaseous ammonia and acetaldehyde, respectively. However, the activity was only a factor of ~1.5 higher for the photodegradation of hydrogen sulfide. These observations are systematically explained by the charge separation efficiency and the adsorption characteristics of each catalyst as well as by the physical and electrochemical properties of each

DNA hybridization kinetics: zippering, internal displacement and sequence dependence.

Science.gov (United States)

Ouldridge, Thomas E; Sulc, Petr; Romano, Flavio; Doye, Jonathan P K; Louis, Ard A

2013-10-01

Although the thermodynamics of DNA hybridization is generally well established, the kinetics of this classic transition is less well understood. Providing such understanding has new urgency because DNA nanotechnology often depends critically on binding rates. Here, we explore DNA oligomer hybridization kinetics using a coarse-grained model. Strand association proceeds through a complex set of intermediate states, with successful binding events initiated by a few metastable base-pairing interactions, followed by zippering of the remaining bonds. But despite reasonably strong interstrand interactions, initial contacts frequently dissociate because typical configurations in which they form differ from typical states of similar enthalpy in the double-stranded equilibrium ensemble. Initial contacts must be stabilized by two or three base pairs before full zippering is likely, resulting in negative effective activation enthalpies. Non-Arrhenius behavior arises because the number of base pairs required for nucleation increases with temperature. In addition, we observe two alternative pathways-pseudoknot and inchworm internal displacement-through which misaligned duplexes can rearrange to form duplexes. These pathways accelerate hybridization. Our results explain why experimentally observed association rates of GC-rich oligomers are higher than rates of AT- rich equivalents, and more generally demonstrate how association rates can be modulated by sequence choice.

A neural model of border-ownership from kinetic occlusion.

Science.gov (United States)

Layton, Oliver W; Yazdanbakhsh, Arash

2015-01-01

Camouflaged animals that have very similar textures to their surroundings are difficult to detect when stationary. However, when an animal moves, humans readily see a figure at a different depth than the background. How do humans perceive a figure breaking camouflage, even though the texture of the figure and its background may be statistically identical in luminance? We present a model that demonstrates how the primate visual system performs figure-ground segregation in extreme cases of breaking camouflage based on motion alone. Border-ownership signals develop as an emergent property in model V2 units whose receptive fields are nearby kinetically defined borders that separate the figure and background. Model simulations support border-ownership as a general mechanism by which the visual system performs figure-ground segregation, despite whether figure-ground boundaries are defined by luminance or motion contrast. The gradient of motion- and luminance-related border-ownership signals explains the perceived depth ordering of the foreground and background surfaces. Our model predicts that V2 neurons, which are sensitive to kinetic edges, are selective to border-ownership (magnocellular B cells). A distinct population of model V2 neurons is selective to border-ownership in figures defined by luminance contrast (parvocellular B cells). B cells in model V2 receive feedback from neurons in V4 and MT with larger receptive fields to bias border-ownership signals toward the figure. We predict that neurons in V4 and MT sensitive to kinetically defined figures play a crucial role in determining whether the foreground surface accretes, deletes, or produces a shearing motion with respect to the background. Copyright © 2014 Elsevier Ltd. All rights reserved.

Crystallization in polydisperse colloidal suspensions

International Nuclear Information System (INIS)

Martin, S.; Bryant, G.; Van Megen, W.

2004-01-01

Full text: Crystallization and glass formation in colloidal hard spheres has been a very active area of research over the last 15-20 years. For most of this time particle polydispersity has been considered to be a minor concern in these studies. However, over the last few years an increasing number of simulations, theoretical work and experiments have shown that consideration of the polydispersity is critical in understanding these phenomena. In this paper we provide an overview of recent crystallization studies on particles with two very different particle size distributions. These particles exhibit very different equilibrium crystal structures and crystallization kinetics. Based on these measurements and time lapse photographs, we propose a growth mechanism whereby crystallization occurs in conjunction with a local fractionation process near the crystal-fluid interface, which significantly alters the kinetics of crystallite nucleation and growth. This fractionation effect becomes more significant as polydispersity or skewness increases. The unusual crystal structures observed are explained using a schematic model that explains the structure in terms of stacks of planes, which are unregistered due to a high incidence of stacking faults caused by the incorporation of a large number of small particles

Embolia cutis medicamentosa: an unusual adverse reaction to terlipressin

Science.gov (United States)

Gatos-Gatopoulos, Polychronis; Kostantoudakis, Stephanos; Panayiotides, Ioannis G.; Dimitriadis, George D.; Triantafyllou, Konstantinos

2017-01-01

Terlipressin is a synthetic long-acting analog of vasopressin widely used to control variceal bleeding by lowering portal venous pressure. We report an unusual adverse reaction to terlipressin in a 78-year-old patient with esophageal variceal bleeding who developed skin necrosis soon after treatment initiation. Skin biopsy revealed embolia cutis medicamentosa. PMID:29118569

Neck mass: An unusual presentation of prostate cancer metastasis ...

African Journals Online (AJOL)

Globally, prostate cancer is a disease of public health importance and it is most common among men between 60 to 70 years of age. Distant primaries involving supraclavicular nodes secondary to prostate cancer is very rare. This report is a case of an unusual presentation of prostate cancer manifesting as a huge neck ...

Adsorption analysis equilibria and kinetics

CERN Document Server

Do, Duong D

1998-01-01

This book covers topics of equilibria and kinetics of adsorption in porous media. Fundamental equilibria and kinetics are dealt with for homogeneous as well as heterogeneous particles. Five chapters of the book deal with equilibria and eight chapters deal with kinetics. Single component as well as multicomponent systems are discussed. In kinetics analysis, we deal with the various mass transport processes and their interactions inside a porous particle. Conventional approaches as well as the new approach using Maxwell-Stefan equations are presented. Various methods to measure diffusivity, such

Kinematics and kinetics of elite windmill softball pitching.

Science.gov (United States)

Werner, Sherry L; Jones, Deryk G; Guido, John A; Brunet, Michael E

2006-04-01

A significant number of time-loss injuries to the upper extremity in elite windmill softball pitchers has been documented. The number of outings and pitches thrown in 1 week for a softball pitcher is typically far in excess of those seen in baseball pitchers. Shoulder stress in professional baseball pitching has been reported to be high and has been linked to pitching injuries. Shoulder distraction has not been studied in an elite softball pitching population. The stresses on the throwing shoulder of elite windmill pitchers are similar to those found for professional baseball pitchers. Descriptive laboratory study. Three-dimensional, high-speed (120 Hz) video data were collected on rise balls from 24 elite softball pitchers during the 1996 Olympic Games. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing shoulder were calculated. Multiple linear regression analysis was used to relate shoulder stress and pitching mechanics. Shoulder distraction stress averaged 80% of body weight for the Olympic pitchers. Sixty-nine percent of the variability in shoulder distraction can be explained by a combination of 7 parameters related to pitching mechanics. Excessive distraction stress at the throwing shoulder is similar to that found in baseball pitchers, which suggests that windmill softball pitchers are at risk for overuse injuries. Normative information regarding upper extremity kinematics and kinetics for elite softball pitchers has been established.

Chemical composition of HAL, an isotopically-unusual Allende inclusion

International Nuclear Information System (INIS)

Davis, A.M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G.J.

1982-01-01

Thirty-seven major, minor and trace elements were determined by INAA and RNAA in samples of hibonite, black rim and portions of friable rim from an unusual Allende inclusion, HAL. The peculiar isotopic, mineralogical and textural properties of HAL are accompanied by very unusual trace element abundances. The most striking feature of the chemistry is the virtual absence of Ce from an inclusion otherwise highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os and Ir, relative to other refractory elements. Of the lithophile elements determined which are normally considered to be refractory in a gas of solar composition, Sr, Ba, Ce, U and V are the most volatile in oxidizing gases. The distribution of REE between hibonite and rims seems to have been established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. On the basis of HAL's chemical and isotopic composition, possible locations for the chemical and mass dependent isotopic fractionation are discussed. (author)

Estimating kinetic mechanisms with prior knowledge I: Linear parameter constraints.

Science.gov (United States)

Salari, Autoosa; Navarro, Marco A; Milescu, Mirela; Milescu, Lorin S

2018-02-05

To understand how ion channels and other proteins function at the molecular and cellular levels, one must decrypt their kinetic mechanisms. Sophisticated algorithms have been developed that can be used to extract kinetic parameters from a variety of experimental data types. However, formulating models that not only explain new data, but are also consistent with existing knowledge, remains a challenge. Here, we present a two-part study describing a mathematical and computational formalism that can be used to enforce prior knowledge into the model using constraints. In this first part, we focus on constraints that enforce explicit linear relationships involving rate constants or other model parameters. We develop a simple, linear algebra-based transformation that can be applied to enforce many types of model properties and assumptions, such as microscopic reversibility, allosteric gating, and equality and inequality parameter relationships. This transformation converts the set of linearly interdependent model parameters into a reduced set of independent parameters, which can be passed to an automated search engine for model optimization. In the companion article, we introduce a complementary method that can be used to enforce arbitrary parameter relationships and any constraints that quantify the behavior of the model under certain conditions. The procedures described in this study can, in principle, be coupled to any of the existing methods for solving molecular kinetics for ion channels or other proteins. These concepts can be used not only to enforce existing knowledge but also to formulate and test new hypotheses. © 2018 Salari et al.

The unusual kinematics of the galaxy IC 10

International Nuclear Information System (INIS)

Cohen, R.J.

1979-01-01

Observations of neutral hydrogen emission from the galaxy IC 10 show a large outer envelope of gas more than 1 0 in extent. The emission has a velocity gradient along the major axis in the opposite sense to that of the central concentration mapped by Shostak. This unusual velocity reversal can be interpreted in terms of a warped gas-layer in normal rotation and seen face-on. (author)

An unusual presentation of postpartum ovarian vein thrombosis

International Nuclear Information System (INIS)

Hakim, Fayaz A.; Khan, Nadra N.; Qushmaq, Khalid A.; Al-Shami, Sadiq Y.

2007-01-01

Ovarian vein thrombosis is a rare but potentially serious complication following childbirth. The majority of patients present during the first week postpartum, with fever and right lower quadrant abdominal pain. We report an unusual case of postpartum ovarian vein thrombosis who presented with fever, low backache, and painful thighs. A high index of suspicion is crucial to diagnose and treat this condition in order to avoid serious consequences. (author)

POEMS syndrome: unusual radiographic, scintigraphic and CT features

International Nuclear Information System (INIS)

Narvaez, J.A.; Majos, C.; Valls, C.; Fernandez-Cabrera, L.; Narvaez, J.

1998-01-01

POEMS syndrome is a multisystemic disorder related to a plasma cell dyscrasia. Radiologically, this syndrome is characterized by sclerotic focal bone lesions with a normal radionuclide bone scan. We report a case of POEMS syndrome with an expansile lytic lesion in the sternum showing periosteal reaction and soft tissue mass, which revealed locally increased uptake of radiotracer in bone scintigraphy. These unusual findings and the differential diagnosis are discussed. (orig.)

An Unusual Cause of Precordial Chest Pain

Directory of Open Access Journals (Sweden)

Sevket Ozkaya

2013-01-01

Full Text Available Extraskeletal chondrosarcoma in anterior mediastinum is very rare. A 45-year-old male patient was admitted to the hospital with precordial chest pain. A large and well-shaped mass in the anterior mediastinum was seen radiologically, and there was a clearly compression of the heart by the mass. The lesion was totally resected, and extraskeletal mediastinal chondrosarcoma was histopathologically diagnosed. We aimed to present and discuss the radiologic, clinic, and histopathologic features of unusual presentation of extraskeletal chondrosarcoma in a case.

Microfilaria in pleural effusion: An unusual association

Directory of Open Access Journals (Sweden)

Rehena Sarkar

2016-01-01

Full Text Available Lymphatic filariasis is a major public health problem in tropical countries and India is endemic for it. However, lymphatic filariasis presenting as pleural effusion is an unusual manifestation and finding microfilaria in pleural effusion without any lung pathology is rare. We report a case of pleural effusion without any underlying lung pathology and normal blood picture. Clinical cure occurred after treatment with diethyl-carbamazepine. Filariasis should be kept in view while considering the differential diagnosis of idiopathic pleural effusion, especially in endemic countries.

Present status on numerical algorithms and benchmark tests for point kinetics and quasi-static approximate kinetics

International Nuclear Information System (INIS)

Ise, Takeharu

1976-12-01

Review studies have been made on algorithms of numerical analysis and benchmark tests on point kinetics and quasistatic approximate kinetics computer codes to perform efficiently benchmark tests on space-dependent neutron kinetics codes. Point kinetics methods have now been improved since they can be directly applied to the factorization procedures. Methods based on Pade rational function give numerically stable solutions and methods on matrix-splitting are interested in the fact that they are applicable to the direct integration methods. An improved quasistatic (IQ) approximation is the best and the most practical method; it is numerically shown that the IQ method has a high stability and precision and the computation time which is about one tenth of that of the direct method. IQ method is applicable to thermal reactors as well as fast reactors and especially fitted for fast reactors to which many time steps are necessary. Two-dimensional diffusion kinetics codes are most practicable though there exist also three-dimensional diffusion kinetics code as well as two-dimensional transport kinetics code. On developing a space-dependent kinetics code, in any case, it is desirable to improve the method so as to have a high computing speed for solving static diffusion and transport equations. (auth.)

Hepatic Parasitic Abscess Caused by Clonorchiasis: Unusual CT Findings of Clonorchiasis

Energy Technology Data Exchange (ETDEWEB)

Jang, Yun Jin; Byun, Jae Ho; Yoon, Seong Eon; Yu, Eun Sil [University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2007-02-15

We report here on the CT findings of an unusual case of hepatic parasitic abscess that was caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts. lonorchiasis is a snail-transmitted, parasitic disease of the bile ducts; this is caused by chronic infestation of liver flukes, Clonorchis sinensis, which reside mainly in the medium- and small-sized intrahepatic bile ducts. The CT, ultrasonograms and cholangiograms of clonorchiasis patients usually show diffuse, uniform, minimal or mild dilatation of the small intrahepatic bile ducts, particularly in the periphery, without dilatation of the extrahepatic bile duct. We report here on the CT findings of an unusual case of hepatic parasitic abscess caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts.

Hepatic Parasitic Abscess Caused by Clonorchiasis: Unusual CT Findings of Clonorchiasis

International Nuclear Information System (INIS)

Jang, Yun Jin; Byun, Jae Ho; Yoon, Seong Eon; Yu, Eun Sil

2007-01-01

We report here on the CT findings of an unusual case of hepatic parasitic abscess that was caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts. lonorchiasis is a snail-transmitted, parasitic disease of the bile ducts; this is caused by chronic infestation of liver flukes, Clonorchis sinensis, which reside mainly in the medium- and small-sized intrahepatic bile ducts. The CT, ultrasonograms and cholangiograms of clonorchiasis patients usually show diffuse, uniform, minimal or mild dilatation of the small intrahepatic bile ducts, particularly in the periphery, without dilatation of the extrahepatic bile duct. We report here on the CT findings of an unusual case of hepatic parasitic abscess caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts

Computer jargon explained

CERN Document Server

Enticknap, Nicholas

2014-01-01

Computer Jargon Explained is a feature in Computer Weekly publications that discusses 68 of the most commonly used technical computing terms. The book explains what the terms mean and why the terms are important to computer professionals. The text also discusses how the terms relate to the trends and developments that are driving the information technology industry. Computer jargon irritates non-computer people and in turn causes problems for computer people. The technology and the industry are changing so rapidly; it is very hard even for professionals to keep updated. Computer people do not

Unusual computed tomography findings and complications in acute appendicitis; Aspectos tomograficos incomuns da apendicite aguda e suas complicacoes

Energy Technology Data Exchange (ETDEWEB)

Palacio, Glaucia Andrade e Silva; D' Ippolito, Giuseppe [Hospital Sao Luiz, Sao Paulo, SP (Brazil). Setor de Diagnostico por Imagem]. E-mail: glauciapalacio@uol.com.br; Bianco, Fabio Davolio [Hospital Sao Luiz, Sao Paulo, SP (Brazil). Setor de Tomografia Computadorizada e Ressonancia Magnetica; Domenicis Junior, Osvaldo de [CURA Imagem e Diagnostico, Sao Paulo, SP (Brazil)

2003-07-01

The objective of this article is to describe and illustrate unusual computed tomography (CT) findings in patients with acute appendicitis. We reviewed the charts of 200 patients with clinical suspicion of acute appendicitis who were submitted to abdominal CT before surgery. Patients with unusual presentation or complications were selected for illustrating the main CT findings. Unusual complications of acute appendicitis were related to anomalous position of the appendix, contiguity to intraperitoneal organs such as the liver, gall bladder, annexes and the bladder and continuous use of anti inflammatory or antibiotics during the diagnostic process. We concluded that CT is a useful diagnostic tool in patients with complicated or unusual presentation acute appendicitis. The first step towards diagnosis in these cases i to have in mind the hypothesis of appendicitis in patients with acute abdominal pain. (author)

Granulocyte kinetics

International Nuclear Information System (INIS)

Peters, A.M.; Lavender, J.P.; Saverymuttu, S.H.

1985-01-01

By using density gradient materials enriched with autologous plasma, the authors have been able to isolate granulocutes from other cellular elements and label them with In-111 without separation from a plasma environment. The kinetic behavior of these cells suggests that phenomena attributed to granulocyte activation are greatly reduced by this labeling. Here, they review their study of granulocyte kinetics in health and disease in hope of quantifying sites of margination and identifying principal sites of destruction. The three principle headings of the paper are distribution, life-span, and destruction

Detection of Unusual Events and Trends in Complex Non-Stationary Data Streams

International Nuclear Information System (INIS)

Perez, Rafael B.; Protopopescu, Vladimir A.; Worley, Brian Addison; Perez, Cristina

2006-01-01

The search for unusual events and trends hidden in multi-component, nonlinear, non-stationary, noisy signals is extremely important for a host of different applications, ranging from nuclear power plant and electric grid operation to internet traffic and implementation of non-proliferation protocols. In the context of this work, we define an unusual event as a local signal disturbance and a trend as a continuous carrier of information added to and different from the underlying baseline dynamics. The goal of this paper is to investigate the feasibility of detecting hidden intermittent events inside non-stationary signal data sets corrupted by high levels of noise, by using the Hilbert-Huang empirical mode decomposition method

An unusual food plant for Cydia pomonella (Linnaeus (Lepidoptera, Tortricidae in Mexico

Directory of Open Access Journals (Sweden)

Alejandro Salinas-Castro

2014-09-01

Full Text Available An unusual food plant for Cydia pomonella (Linnaeus (Lepidoptera, Tortricidae in Mexico. Larvae of Cydia pomonella (Linnaeus, 1758 were discovered on floral cones of Magnolia schiedeana (Schltdl, 1864 near the natural reserve of La Martinica, Veracruz, México. Magnolia represents an unusual host for this moth species, which is known throughout the world as the "codling moth", a serious pest of fruits of Rosaceae, especially apples. The larvae were identified using taxonomic keys, and identification was corroborated using molecular markers. Further sampling resulted in no additional larvae, hence, the observation was probably that of an ovipositional error by the female, and M. schiedeana is not at risk of attack by this important moth pest.

Atypical presentation of bilateral supplemental maxillary central incisors with unusual talon cusp

Directory of Open Access Journals (Sweden)

Sivakumar Nuvvula

2011-01-01

Full Text Available Delayed eruption of maxillary permanent central incisors in a child poses a distressing esthetic quandary to parents, by virtue of its location in the dental architecture. Well-aligned anterior teeth add confidence to smile and have enhanced self-esteem, which is critical even in early life. Impaction of the maxillary central incisors compared to third molars or the canines is less reported; bilateral supplemental maxillary central incisors related to impacted permanent maxillary central incisors are rare and one of the supplemental central incisors showing unusual talon is still infrequent. A case of impacted maxillary permanent central incisors related to supplemental maxillary central incisors, with one of them showing an unusual talon cusp, is presented.

Emergency surgical management of traumatic superior sagittal sinus injury: An unusual case

Directory of Open Access Journals (Sweden)

Sudhansu Sekhar Mishra

2012-01-01

Full Text Available Head injuries following fall of heavy objects are not very uncommon in developing countries. However, compound depressed skull fracture with superior sagittal sinus (SSS laceration caused by a flying asbestos fragment in a stormy afternoon is an unusual mode of head injury. We report such an unusual case of compound depressed skull fracture by an asbestos fragment injuring the middle third of SSS and its successful surgical management in a 14-year-old child. The role of computed tomography (CT scan of head with 3D reconstruction is highlighted. Early steps taken in this case to check the profuse bleeding, which helped save the life of this boy is interesting to note.

How unusual was autumn 2006 in Europe?

Directory of Open Access Journals (Sweden)

G. J. van Oldenborgh

2007-11-01

Full Text Available The temperatures in large parts of Europe have been record high during the meteorological autumn of 2006. Compared to 1961–1990, the 2 m temperature was more than three degrees Celsius above normal from the North side of the Alps to southern Norway. This made it by far the warmest autumn on record in the United Kingdom, Belgium, the Netherlands, Denmark, Germany and Switzerland, with the records in Central England going back to 1659, in the Netherlands to 1706 and in Denmark to 1768. The deviations were so large that under the obviously false assumption that the climate does not change, the observed temperatures for 2006 would occur with a probability of less than once every 10 000 years in a large part of Europe, given the distribution defined by the temperatures in the autumn 1901–2005.

A better description of the temperature distribution is to assume that the mean changes proportional to the global mean temperature, but the shape of the distribution remains the same. This includes to first order the effects of global warming. Even under this assumption the autumn temperatures were very unusual, with estimates of the return time of 200 to 2000 years in this region. The lower bound of the 95% confidence interval is more than 100 to 300 years.

Apart from global warming, linear effects of a southerly circulation are found to give the largest contributions, explaining about half of the anomalies. SST anomalies in the North Sea were also important along the coast.

Climate models that simulate the current atmospheric circulation well underestimate the observed mean rise in autumn temperatures. They do not simulate a change in the shape of the distribution that would increase the probability of warm events under global warming. This implies that the warm autumn 2006 either was a very rare coincidence, or the local temperature rise is much stronger than modelled, or non-linear physics that is missing from these models

Observation of the Unusual Aggregation Kinetics of Colloidal ...

Indian Academy of Sciences (India)

of Holthoff et al.,26 the coagulation rate constants can be obtained ... Rui Tian et al. Hofmeister ... work are nano-scale materials made up of one Al-O ..... and Ninham B 2006 J. Mol. Liq. ... Zhang Y, Furyk S, Bergbreiter D and Cremer P 2005.

Micellar effect on the kinetics of oxidation of methyl blue by Ce(IV in sulfuric acid medium

Directory of Open Access Journals (Sweden)

Mohammed Hassan

2015-01-01

Full Text Available The kinetics of oxidation of methyl blue (MB by Ce(IV in aqueous and surfactant media has been carried out to explore the micellar effect on the rate and kinetic parameters of the reaction. The reaction was found to be first order with respect to both oxidant and substrate and fractional order with respect to H+. The active kinetic species of the oxidant was found to be Ce(SO4+2 based on the effect of ionic strength and sulfate ion on the rate of the reaction. The presence of micelles was found to inhibit the reaction and this effect has been explained by the association of one of the reactants with the micelles leaving the other reactant in the bulk solution. The binding constant and first order rate constant in micellar medium has been obtained by the application of pseudo-phase model to the experimental data. Interestingly, the temperature dependence of the reaction reveals that the reaction has negative activation energy in the absence of micelles, which turns to a positive value in the presence of micelles.

Unusual kinetics of poly(ethylene glycol) oxidation with cerium(IV) ions in sulfuric acid medium and implications for copolymer synthesis.

Science.gov (United States)

Szymański, Jan K; Temprano-Coleto, Fernando; Pérez-Mercader, Juan

2015-03-14

The cerium(IV)-alcohol couple in an acidic medium is an example of a redox system capable of initiating free radical polymerization. When the alcohol has a polymeric nature, the outcome of such a process is a block copolymer, a member of a class of compounds possessing many useful properties. The most common polymer with a terminal -OH group is poly(ethylene glycol) (PEG); however, the detailed mechanism of its reaction with cerium(IV) remains underexplored. In this paper, we report our findings for this reaction based on spectrophotometric measurements and kinetic modeling. We find that both the reaction order and the net rate constant for the oxidation process depend strongly on the nature of the acidic medium used. In order to account for the experimental observations, we postulate that protonation of PEG decreases its affinity for some of the cerium(IV)-sulfate complexes formed in the system.

Unusual Wrist Tremor: Unilateral Isometric Tremor?

Directory of Open Access Journals (Sweden)

Theresa A. Zesiewicz

2014-01-01

Full Text Available Background: Tremors may be difficult to classify.Case Report: An 83‐year‐old male presented with an unusual left wrist tremor. The tremor could be reproducibly elicited by making a fist or carrying a weighted object (e.g., a shopping bag, bottle of water of approximately 1 lb or more, and it intensified with heavier weights. The tremor was difficult to classify, although it shared features with isometric tremor.Discussion: This specific presentation of tremor has not been reported previously. We hope that the detailed description we provide will aid other neurologists who encounter this or similar tremors in their clinics.

Unusual Amino Acids in Medicinal Chemistry.

Science.gov (United States)

Blaskovich, Mark A T

2016-12-22

Unusual amino acids are fundamental building blocks of modern medicinal chemistry. The combination of readily functionalized amine and carboxyl groups attached to a chiral central core along with one or two potentially diverse side chains provides a unique three-dimensional structure with a high degree of functionality. This makes them invaluable as starting materials for syntheses of complex molecules, highly diverse elements for SAR campaigns, integral components of peptidomimetic drugs, and potential drugs on their own. This Perspective highlights the diversity of unnatural amino acid structures found in hit-to-lead and lead optimization campaigns and clinical stage and approved drugs, reflecting their increasingly important role in medicinal chemistry.

On the effect of pre-oxidation on the nitriding kinetics

DEFF Research Database (Denmark)

Friehling, Peter Bernhard; Somers, Marcel A. J.

2000-01-01

The oxidation of ferritic surfaces prior to gaseous nitriding has been reported to lead to improved uniformity of the compound layer thickness and enhanced nitriding kinetics. The present work considers the nucleation and growth of a model compound layer on pure iron and, using previous...... experimental and theoretical work reported in the literature, puts forward two hypotheses to explain the effects of pre-oxidation on compound layer formation. It is proposed that the nucleation of iron nitrides is enhanced by the presence of an iron-oxide layer and that the growth of an iron-nitride layer...... proceeds faster after pre-oxidation, due to a higher nitrogen content in the part of the compound layer closest to the surface....

Chemically stabilized epitaxial wurtzite-BN thin film

Science.gov (United States)

Vishal, Badri; Singh, Rajendra; Chaturvedi, Abhishek; Sharma, Ankit; Sreedhara, M. B.; Sahu, Rajib; Bhat, Usha; Ramamurty, Upadrasta; Datta, Ranjan

2018-03-01

We report on the chemically stabilized epitaxial w-BN thin film grown on c-plane sapphire by pulsed laser deposition under slow kinetic condition. Traces of no other allotropes such as cubic (c) or hexagonal (h) BN phases are present. Sapphire substrate plays a significant role in stabilizing the metastable w-BN from h-BN target under unusual PLD growth condition involving low temperature and pressure and is explained based on density functional theory calculation. The hardness and the elastic modulus of the w-BN film are 37 & 339 GPa, respectively measured by indentation along direction. The results are extremely promising in advancing the microelectronic and mechanical tooling industry.

A Unified Model of Phantom Energy and Dark Matter

Science.gov (United States)

Chaves, Max; Singleton, Douglas

2008-01-01

To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys w = p/ρ theories based on graded Lie algebras naturally have such a negative kinetic energy and thus give a model for phantom energy in a less ad hoc manner. We find that the model also contains ordinary scalar fields and anti-commuting (Grassmann) vector fields which act as a form of two component dark matter. Thus from a gauge theory based o! n a graded algebra we naturally obtained both phantom energy and dark matter.

Water absorption and biodegradation kinetics of highly filled EOC-FS biocomposites

Science.gov (United States)

Zykova, A. K.; Pantyukhov, P. V.; Platov, Yu. T.; Bobojonova, G. A.; Ramos, C. Chaverri; Popov, A. A.

2017-12-01

The paper analyzes the water absorption and biodegradation kinetics in highly filled biocomposites based on ethylene-octene copolymer (EOC) and oil flax straw (FS). It is shown that adding the filler to EOC increases the water absorption from 0 to 22%. The tendency can be explained both by the low interfacial adhesion of EOC to FS and by the hydrophilic nature of the filler. According to biodegradation tests (10 months), the mass of pure EOC remains unchanged, suggesting that it fails to biodegrade in the environment. Increasing the filler content increases the weight loss of the composites and the degree of microbiological contamination (fungi filaments, bacteria) as evidenced by optical microscopy.

Kinetic Monte Carlo simulation of formation of microstructures in liquid droplets

International Nuclear Information System (INIS)

Block, M; Kunert, R; Schoell, E; Boeck, T; Teubner, Th

2004-01-01

We study the deposition of indium droplets on a glass surface and the subsequent formation of silicon microcrystals inside these droplets. Kinetic Monte Carlo methods are used to analyse the influence of growth temperature, flux of incoming particles, surface coverage, and in particular an energy parameter simulating the surface tension, upon the morphology of growth. According to the experimental conditions of crystallization, a temperature gradient and diffusion in spherical droplets are included. The simulations explain the formation of silicon crystal structures in good agreement with the experiment. The dependence of their shape and the conditions of formation on the growth parameters are investigated in detail

Kinetic Alfven Waves at the Magnetopause-Mode Conversion, Transport and Formation of LLBL; TOPICAL

International Nuclear Information System (INIS)

Jay R. Johnson; C.Z. Cheng

2002-01-01

At the magnetopause, large amplitude, low-frequency (ULF), transverse MHD waves are nearly always observed. These waves likely result from mode conversion of compressional MHD waves observed in the magnetosheath to kinetic Alfven waves at the magnetopause where there is a steep gradient in the Alfven velocity[Johnson and Cheng, Geophys. Res. Lett. 24 (1997) 1423]. The mode-conversion process can explain the following wave observations typically found during satellite crossings of the magnetopause: (1) a dramatic change in wave polarization from compressional in the magnetosheath to transverse at the magnetopause, (2) an amplification of wave amplitude at the magnetopause, (3) a change in Poynting flux from cross-field in the magnetosheath to field-aligned at the magnetopause, and (4) a steepening in the wave power spectrum at the magnetopause. We examine magnetic field data from a set of ISEE1, ISEE2, and WIND magnetopause crossings and compare with the predictions of theoretical wave solutions based on the kinetic-fluid model with particular attention to the role of magnetic field rotation across the magnetopause. The results of the study suggest a good qualitative agreement between the observations and the theory of mode conversion to kinetic Alfven waves. Because mode-converted kinetic Alfven waves readily decouple particles from the magnetic field lines, efficient quasilinear transport (D(approx) 109m2/s) can occur. Moreover, if the wave amplitude is sufficiently large (Bwave/B0 and gt; 0.2) stochastic particle transport also occurs. This wave-induced transport can lead to significant heating and particle entry into the low latitude boundary layer across closed field lines.At the magnetopause, large amplitude, low-frequency (ULF), transverse MHD waves are nearly always observed. These waves likely result from mode conversion of compressional MHD waves observed in the magnetosheath to kinetic Alfven waves at the magnetopause where there is a steep gradient in

Kinetics that govern the release of tritium from neutron-irradiated lithium oxide

International Nuclear Information System (INIS)

Bertone, P.C.

1986-01-01

The Lithium Blanket Module (LBM) program being conducted at the Princeton Plasma Physics Laboratory requires that tritium concentrations as low as 0.1 nCi/g, bred in both LBM lithium oxide pellets and gram-size lithium samples, be measured with an uncertainty not exceeding +/-6%. This thesis reports two satisfactory methods of assaying LBM pellets and one satisfactory method of assaying lithium samples. Results of a fundamental kinetic investigation are also reported. The thermally driven release of tritium from neutron-irradiated lithium oxide pellets is studied between the temperatures of 300 and 400 0 C. The observed release clearly obeys first-order kinetics, and the governing activation energy appears to be 28.4 kcal/mole. Finally, a model is presented that may explain the thermally driven release of tritium from a lithium oxide crystal and assemblies thereof. It predicts that under most circumstances the release is controlled by either the diffusion of a tritiated species through the crystal, or by the desorption of tritiated water from it

Irreversible processes kinetic theory

CERN Document Server

Brush, Stephen G

2013-01-01

Kinetic Theory, Volume 2: Irreversible Processes deals with the kinetic theory of gases and the irreversible processes they undergo. It includes the two papers by James Clerk Maxwell and Ludwig Boltzmann in which the basic equations for transport processes in gases are formulated, together with the first derivation of Boltzmann's ""H-theorem"" and a discussion of this theorem, along with the problem of irreversibility.Comprised of 10 chapters, this volume begins with an introduction to the fundamental nature of heat and of gases, along with Boltzmann's work on the kinetic theory of gases and s

Drug-Target Kinetics in Drug Discovery.

Science.gov (United States)

Tonge, Peter J

2018-01-17

The development of therapies for the treatment of neurological cancer faces a number of major challenges including the synthesis of small molecule agents that can penetrate the blood-brain barrier (BBB). Given the likelihood that in many cases drug exposure will be lower in the CNS than in systemic circulation, it follows that strategies should be employed that can sustain target engagement at low drug concentration. Time dependent target occupancy is a function of both the drug and target concentration as well as the thermodynamic and kinetic parameters that describe the binding reaction coordinate, and sustained target occupancy can be achieved through structural modifications that increase target (re)binding and/or that decrease the rate of drug dissociation. The discovery and deployment of compounds with optimized kinetic effects requires information on the structure-kinetic relationships that modulate the kinetics of binding, and the molecular factors that control the translation of drug-target kinetics to time-dependent drug activity in the disease state. This Review first introduces the potential benefits of drug-target kinetics, such as the ability to delineate both thermodynamic and kinetic selectivity, and then describes factors, such as target vulnerability, that impact the utility of kinetic selectivity. The Review concludes with a description of a mechanistic PK/PD model that integrates drug-target kinetics into predictions of drug activity.

Unusual occurrence of congenital hypothyroidism in a set of same ...

African Journals Online (AJOL)

Congenital hypothyroidism is the most common endocrinological disorder in children. Genetic and intrauterine factors have been implicated in its aetiology. The aim of this study was to describe an unusual occurrence of congenital hypothyroidism in a set of same sex triplets and challenges associated with the diagnosis.

The Frequent Unusual Headache Syndromes: A Proposed Classification Based on Lifetime Prevalence.

Science.gov (United States)

Valença, Marcelo M; de Oliveira, Daniella A

2016-01-01

There is no agreement on a single cutoff point or prevalence for regarding a given disease as rare. The concept of what is a rare headache disorder is even less clear and the spectrum from a very frequent, frequent, occasional to rare headache syndrome is yet to be established. An attempt has been made to estimate the lifetime prevalence of each of the headache subtypes classified in the ICHD-II. Using the ICHD-II, 199 different headache subtypes were identified. The following classification was made according to the estimated lifetime prevalence of each headache disorder: very frequent (prevalence >10%); frequent (between 1 and 10%); occasional (between 0.07 and 1%); and unusual or rare (headache disorders, 7/199 (4%) as very frequent, 9/199 (5%) as frequent, and 29/199 (15%) as occasional forms of headache disorder. The unusual headache syndromes do not appear to be as infrequent in clinical practice as has been generally believed. About three-fourths of the classified headache disorders found in the ICHD-II can be considered as rare. This narrative review article may be regarded as an introduction to the concept of unusual headaches and a proposed classification of all headaches (at least those listed in the ICHD-II). © 2015 American Headache Society.

Exposure to unusually high indoor radon levels

International Nuclear Information System (INIS)

Rasheed, F.N.

1993-01-01

Unusually high indoor radon concentrations were reported in a small village in western Tyrol, Austria. The authors have measured the seasonal course of indoor radon concentrations in 390 houses of this village. 71% of houses in winter and 33% in summer, showed radon values on the ground floor above the Austrian action level of 400 Bq/cm 3 . This proportion results in an unusually high indoor radon exposure of the population. The radon source was an 8,700-year-old rock slide of granite gneiss, the largest of the alpine crystalline rocks. It has a strong emanating power because its rocks are heavily fractured and show a slightly increased uranium content. Previous reports show increased lung cancer mortality, myeloid leukemia, kidney cancer, melanoma, and prostate cancer resulting from indoor radon exposure. However, many studies fail to provide accurate information on indoor radon concentrations, classifying them merely as low, intermediate, and high, or they record only minor increases in indoor radon concentrations. Mortality data for 1970-91 were used to calculate age and sex standardized mortality rates (SMR) for 51 sites of carcinoma. The total population of Tyrol were controls. A significantly higher risk was recorded for lung cancer. The high SMR for lung cancer in female subjects is especially striking. Because the numbers were low for the other cancer sites, these were combined in one group to calculate the SMR. No significant increase in SMR was found for this group

Physisorption kinetics

CERN Document Server

Kreuzer, Hans Jürgen

1986-01-01

This monograph deals with the kinetics of adsorption and desorption of molecules physisorbed on solid surfaces. Although frequent and detailed reference is made to experiment, it is mainly concerned with the theory of the subject. In this, we have attempted to present a unified picture based on the master equation approach. Physisorption kinetics is by no means a closed and mature subject; rather, in writing this monograph we intended to survey a field very much in flux, to assess its achievements so far, and to give a reasonable basis from which further developments can take off. For this reason we have included many papers in the bibliography that are not referred to in the text but are of relevance to physisorption. To keep this monograph to a reasonable size, and also to allow for some unity in the presentation of the material, we had to omit a number of topics related to physisorption kinetics. We have not covered to any extent the equilibrium properties of physisorbed layers such as structures, phase tr...

Unusual Sediment Transportation Processes Under Low Pressure Environments and Implications For Gullies and Recurring Slope Lineae (RSL)

Science.gov (United States)

Raack, J.; Herny, C.; Conway, S. J.; Balme, M. R.; Carpy, S.; Patel, M.

2017-12-01

Recently and presently active mass wasting features such as gullies and recurring slope lineae (RSL) are common on the surface of Mars, but their origin and triggering mechanisms are under intense debate. While several active mass wasting features have been linked to sublimation of CO2ice, dry granular flows (avalanches), or a combination of both effects, others have been more closely linked to liquid water or briny outflows (e.g. for RSL). However, liquid water on the surface of Mars is unstable under present-day low pressures and surface temperatures. Nevertheless, numerical modeling and remote sensing data have shown that maximum surface temperatures can exceed the frost point of water and that liquid water could exist on the surface of actual Mars in a transient state. But to explain the observed spatial extent of RSL and recent modification of gullies, it is estimated that relatively large amounts of liquid water are necessary. It is proving challenging to generate such quantities from the atmosphere. In this contribution we explore the potential effects of boiling water (boiling occurs at martian pressures slightly above the frost point of 273 K) on sediment transport. We will present the outcomes of a series of experiments under low surface and water temperatures (between 278 and 297 K, analogous to surface temperatures observed near RSL) and low pressures (between 8 and 11 mbar). We simulate sediment transport by boiling liquid water over a sloping bed of unconsolidated sediment. Our results reveal a suite of unusual and very reactive sediment transportation processes, which are not produced under terrestrial pressures. We will discuss the impact of these unusual sediment transport processes on estimates of water budgets for active mass wasting processes.

Unusual extension of the first branchial cleft anomaly.

Science.gov (United States)

Ada, Mehmet; Korkut, Nazim; Güvenç, M Güven; Acioğlu, Engin; Yilmaz, Süleyman; Cevikbaş, Uğur

2006-03-01

First branchial cleft is the only branchial structure that persists as the external ear canal, while all other clefts are resorbed. Incomplete obliteration and the degree of closure cause the varied types of first branchial cleft anomalies. They were classified based on the anatomical and histological features. We present an unusual type of first branchial cleft anomaly involving the external auditory canal, the middle ear and the nasopharynx through the eustachian tube.

POEMS syndrome: unusual radiographic, scintigraphic and CT features

Energy Technology Data Exchange (ETDEWEB)

Narvaez, J.A.; Majos, C.; Valls, C.; Fernandez-Cabrera, L. [Department of CT and MR Imaging, Ciudad Sanitaria y Universitaria de Bellvitge, Barcelona (Spain); Narvaez, J. [Department of Rheumatology, Hospital Princeps d`Espanya, L`Hospitalet de Llobregat, Barcelona (Spain)

1998-02-01

POEMS syndrome is a multisystemic disorder related to a plasma cell dyscrasia. Radiologically, this syndrome is characterized by sclerotic focal bone lesions with a normal radionuclide bone scan. We report a case of POEMS syndrome with an expansile lytic lesion in the sternum showing periosteal reaction and soft tissue mass, which revealed locally increased uptake of radiotracer in bone scintigraphy. These unusual findings and the differential diagnosis are discussed. (orig.) With 3 figs., 8 refs.

Nitrate sorption on activated carbon modified with CaCl2: Equilibrium, isotherms and kinetics

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Zanella Odivan

2015-01-01

Full Text Available In this study, nitrate (NO3- removal from aqueous solutions was investigated using granular activated carbon (GAC modified with CaCl2. Batch sorption studies were performed as a function of sorbent dose, initial nitrate concentration and pH. Sorption was maximized between pH 3 and 9. Studies on the effect of pH showed that the ion exchange mechanism might be involved in the sorption process. The percentage of nitrate removed increased with increasing sorbent concentration, and the ideal sorbent dose was found to be 20 g•L-1. Four isotherm models-Langmuir, Freundlich, Redlich-Peterson and Sips-were used to fit the experimental data. The Redlich-Peterson isotherm model explained the sorption process well and showed the best coefficient of determination (0.9979 and Chi-square test statistic (0.0079. Using the Sips isotherm model, the sorption capacity (qe was found to be 1.93 mg nitrate per g of sorbent. Kinetic experiments indicated that sorption was a fast process, reaching equilibrium within 120 min. The nitrate sorption kinetic data were successfully fitted to a pseudo-second-order kinetic model. The overall results demonstrated potential applications of modified GAC for nitrate removal from aqueous solutions.

The Mysteries and Curiosities of Mars: A Tour of Unusual and Unexplained Terrains

Science.gov (United States)

Kerber, L.

2017-12-01

The large amount of data available from orbiting satellites around Mars has provided a wealth of information about the Martian surface and geological history. The published literature tends to focus on regions of Mars for which there are ready explanations; however, many regions of Mars remain mysterious. In this contribution, we present some of the strangest and least explained terrains on Mars: The Taffy Terrain: This complex terrain, consisting of swirling layers with variably sized bands, is present mostly at the bottom of Hellas Basin, but versions of it can also be found on the floor of Melas Chasma and in the Medusae Fossae Formation near Apollinaris Sulci. While little has been written about the taffy terrain, hypotheses include "glacial features" and salt domes. The taffy terrain bears some resemblance to submarine salt domes in the Gulf of Mexico, glacial deposits with mixed ash and ice in Iceland, or chalk formations in Egypt's White Desert. The Fishscale Terrain: At the northern edge of Lucus Planum, the friable Medusae Fossae Formation transitions into a chaos-like terrain with hundreds of mesas forming a pattern like the scales of a fish. While chaos terrains are mysterious in general, this morphologically fresh, near-equatorial chaos is especially unusual. Polygonal Ridges in Gordii Dorsum: Also a part of the Medusae Fossae Formation, the ridges in Gordii Dorsum represent a negative image of the fishscale terrain—a intricate lattice of slender black ridges. These are thought to form via the embayment of the fishscale terrain with lava and the subsequent erosion of the original mesas. Horseshoe Features: These geomorphological features look like inverted barchan dunes, but they are actually pits eroded into the surface of the Medusae Fossae Formation. Channels surrounding Elysium Mons: These channel systems are among the most complex on Mars, but they appear on a young Amazonian lava surface. The channels cut through topography, anastomose, and

Kinetics on Demand Is a Simple Mathematical Solution that Fits Recorded Caffeine-Induced Luminal SR Ca2+ Changes in Smooth Muscle Cells.

Directory of Open Access Journals (Sweden)

Norma C Perez-Rosas

Full Text Available The process of Ca2+ release from sarcoplasmic reticulum (SR comprises 4 phases in smooth muscle cells. Phase 1 is characterized by a large increase of the intracellular Ca2+ concentration ([Ca2+]i with a minimal reduction of the free luminal SR [Ca2+] ([Ca2+]FSR. Importantly, active SR Ca2+ ATPases (SERCA pumps are necessary for phase 1 to occur. This situation cannot be explained by the standard kinetics that involves a fixed amount of luminal Ca2+ binding sites. A new mathematical model was developed that assumes an increasing SR Ca2+ buffering capacity in response to an increase of the luminal SR [Ca2+] that is called Kinetics-on-Demand (KonD model. This approach can explain both phase 1 and the refractory period associated with a recovered [Ca2+]FSR. Additionally, our data suggest that active SERCA pumps are a requisite for KonD to be functional; otherwise luminal SR Ca2+ binding proteins switch to standard kinetics. The importance of KonD Ca2+ binding properties is twofold: a more efficient Ca2+ release process and that [Ca2+]FSR and Ca2+-bound to SR proteins ([Ca2+]BSR can be regulated separately allowing for Ca2+ release to occur (provided by Ca2+-bound to luminal Ca2+ binding proteins without an initial reduction of the [Ca2+]FSR.

Role of point defects and additives in kinetics of hydrogen storage materials

Science.gov (United States)

van de Walle, Chris

2010-03-01

First-principles computational studies of hydrogen interactions with storage materials can provide direct insight into the processes of H uptake and release, and may help in developing guidelines for designing storage media with improved storage capacity and kinetics. One important conclusion is that the defects involved in kinetics of semiconducting or insulating H-storage materials are charged, and hence their formation energy is Fermi-level dependent and can be affected by the presence of impurities that change the Fermi level [1,2]. This provides an explanation for the role played by transition-metal impurities in the kinetics of NaAlH4 and related materials. Desorption of H and decomposition of NaAlH4 requires not only mass transport of H but also of Al and/or Na. This process is mediated by native defects. We have investigated the structure, stability, and migration enthalpy of native defects based on density functional theory. The results allow us to estimate diffusion activation energies for the defects that may be involved in mass transport. Most of the relevant defects exist in charge states other than neutral, and consideration of these charge states is essential for a proper description of kinetics. We propose specific new mechanisms to explain the observed activation energies and their dependence on the presence of impurities. We have also expanded our studies to materials other than NaAlH4. In the case of LiBH4 and Li4BN3H10 we have found that the calculations have predictive power in terms of identifying which impurities will actually enhance kinetics. Other complex hydrides that we are currently investigating include Li2NH and LiNH2. [4pt] [1] A. Peles and C. G. Van de Walle, Phys. Rev. B 76, 214101 (2007). [0pt] [2] C. G. Van de Walle, A. Peles, A. Janotti, and G. B. Wilson-Short, Physica B 404, 793 (2009).

Pasteurella multocida Osteomyelitis: An Unusual Case Presentation

Directory of Open Access Journals (Sweden)

Herbert P von Schroeder

1996-01-01

Full Text Available A healthy male farm employee developed an unusual infection caused by Pasteurella multocida. Atypical features included the chronic nature of the infection, the development of osteomyelitis of the tibia without direct animal inoculation, and lack of fever and leukocytosis. Radiographic appearance of P multocida osteomyelitis may be the result of osteoclast activation and can be confused with musculoskeletal tumour. P multocida infection requires a high degree of suspicion, and should be considered in cases of farm- or animal-related injuries even if there is no history of direct animal contact.

Odontoameloblastoma: A rare case with unusual presentation

Directory of Open Access Journals (Sweden)

Supreet Jain

2016-01-01

Full Text Available The odontoameloblastoma (OA, also known as ameloblastic odontoma, is a very rare odontogenic tumor that is similar to ameloblastoma in its locally aggressive behavior. OA includes odontogenic ectomesenchyme in addition to odontogenic epithelium that resembles an ameloblastoma both in structure and in behavior. Its clinical presentation, however, often mimics the more innocuous odontoma, and hence, the recognition of its aggressive nature is commonly only ascertained after its histopathologic diagnosis following enucleation. This paper presents a rare case of OA with unusual clinical and radiological features.

Unusual clustering of coefficients of variation in published articles from a medical biochemistry department in India.

Science.gov (United States)

Hudes, Mark L; McCann, Joyce C; Ames, Bruce N

2009-03-01

A simple statistical method is described to test whether data are consistent with minimum statistical variability expected in a biological experiment. The method is applied to data presented in data tables in a subset of 84 articles among more than 200 published by 3 investigators in a small medical biochemistry department at a major university in India and to 29 "control" articles selected by key word PubMed searches. Major conclusions include: 1) unusual clustering of coefficients of variation (CVs) was observed for data from the majority of articles analyzed that were published by the 3 investigators from 2000-2007; unusual clustering was not observed for data from any of their articles examined that were published between 1992 and 1999; and 2) among a group of 29 control articles retrieved by PubMed key word, title, or title/abstract searches, unusually clustered CVs were observed in 3 articles. Two of these articles were coauthored by 1 of the 3 investigators, and 1 was from the same university but a different department. We are unable to offer a statistical or biological explanation for the unusual clustering observed.

A kinetics database and scripts for PHREEQC

Science.gov (United States)

Hu, B.; Zhang, Y.; Teng, Y.; Zhu, C.

2017-12-01

Kinetics of geochemical reactions has been increasingly used in numerical models to simulate coupled flow, mass transport, and chemical reactions. However, the kinetic data are scattered in the literature. To assemble a kinetic dataset for a modeling project is an intimidating task for most. In order to facilitate the application of kinetics in geochemical modeling, we assembled kinetics parameters into a database for the geochemical simulation program, PHREEQC (version 3.0). Kinetics data were collected from the literature. Our database includes kinetic data for over 70 minerals. The rate equations are also programmed into scripts with the Basic language. Using the new kinetic database, we simulated reaction path during the albite dissolution process using various rate equations in the literature. The simulation results with three different rate equations gave difference reaction paths at different time scale. Another application involves a coupled reactive transport model simulating the advancement of an acid plume in an acid mine drainage site associated with Bear Creek Uranium tailings pond. Geochemical reactions including calcite, gypsum, and illite were simulated with PHREEQC using the new kinetic database. The simulation results successfully demonstrated the utility of new kinetic database.

Some Aspects of Extended Kinetic Equation

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Dilip Kumar

2015-09-01

Full Text Available Motivated by the pathway model of Mathai introduced in 2005 [Linear Algebra and Its Applications, 396, 317–328] we extend the standard kinetic equations. Connection of the extended kinetic equation with fractional calculus operator is established. The solution of the general form of the fractional kinetic equation is obtained through Laplace transform. The results for the standard kinetic equation are obtained as the limiting case.

Unusual features of long-range density fluctuations in glass-forming organic liquids: A Rayleigh and Rayleigh-Brillouin light scattering study

International Nuclear Information System (INIS)

Patkowski, A.; Fischer, E. W.; Steffen, W.; Glaser, H.; Baumann, M.; Ruths, T.; Meier, G.

2001-01-01

A new feature of glass-forming liquids, i.e., long-range density fluctuations of the order of 100 nm, has been extensively characterized by means of static light scattering, photon correlation spectroscopy and Rayleigh-Brillouin spectroscopy in orthoterphenyl (OTP) and 1,1-di(4 # prime#-methoxy-5 # prime#methyl-phenyl)-cyclohexane (BMMPC). These long-range density fluctuations result in the following unusual features observed in a light scattering experiment, which are not described by the existing theories: (i) strong q-dependent isotropic excess Rayleigh intensity, (ii) additional slow component in the polarized photon correlation function, and (iii) high Landau-Placzek ratio. These unusual features are equilibrium properties of the glass-forming liquids and depend only on temperature, provided that the sample has been equilibrated long enough. The temperature-dependent equilibration times were measured for BMMPC and are about 11 orders of magnitude longer than the α process. It was found that the glass-forming liquid OTP may occur in two states: with and without long-range density fluctuations ('clusters'). We have characterized the two states by static and dynamic light scattering in the temperature range from T g to T g +200 K. The relaxation times of the α process as well as the parameters of the Brillouin line are identical in both OTP with and without clusters. The α process (density fluctuations) in OTP was characterized by measuring either the polarized (VV) or depolarized (VH) correlation function, which are practically identical and q-independent. This feature, which is commonly observed in glass-forming liquids, is not fully explained by the existing theories

A kinetic study of the enhancement of solution chemiluminescence of glyoxylic acid oxidation by manganese species.

Science.gov (United States)

Otamonga, Jean-Paul; Abdel-Mageed, Amal; Agater, Irena B; Jewsbury, Roger A

2015-08-01

In order to study the mechanism of the enhancement of solution chemiluminescence, the kinetics of the decay of the oxidant and the chemiluminescence emission were followed for oxidations by permanganate, manganese dioxide sol and Mn(3+) (aq) of glyoxylic acid, using stopped-flow spectrophotometry. Results are reported for the glyoxylic acid oxidized under pseudo first-order conditions and in an acidic medium at 25 °C. For permanganate under these conditions, the decay is sigmoidal, consistent with autocatalysis, and for manganese dioxide sol and Mn(3+) it is pseudo first order. The effects of the presence of aqueous formaldehyde and Mn(2+) were observed and a fit to a simple mechanism is discussed. It is concluded that chemiluminescent enhancement in these systems is best explained by reaction kinetics. Copyright © 2014 John Wiley & Sons, Ltd.

Smouldering Combustion of Soil Organic Matter: Inverse Modelling of the Thermal and Oxidative Degradation Kinetics

Science.gov (United States)

Huang, Xinyan; Rein, Guillermo

2013-04-01

Smouldering combustion of soil organic matter (SOM) such as peatlands leads to the largest fires on Earth and posses a possible positive feedback mechanism to climate change. In this work, a kinetic model, including 3-step chemical reactions and 1-step water evaporation is proposed to describe drying, pyrolysis and oxidation behaviour of peat. Peat is chosen as the most important type of SOM susceptible to smoudering, and a Chinese boreal peat sample is selected from the literature. A lumped model of mass loss based on four Arrhenius-type reactions is developed to predict its thermal and oxidative degradation under a range of heating rates. A genetic algorithm is used to solve the inverse problem, and find a group of kinetic and stoichiometric parameters for this peat that provides the best match to the thermogravimetric (TG) data from literature. A multi-objective fitness function is defined using the measurements of both mass loss and mass-loss rate in inert and normal atmospheres under a range of heating rates. Piece-wise optimization is conducted to separate the low temperature drying (450 K). Modelling results shows the proposed 3-step chemistry is the unique simplest scheme to satisfy all given TG data of this particular peat type. Afterward, this kinetic model and its kinetic parameters are incorporated into a simple one-dimensional species model to study the relative position of each reaction inside a smoulder front. Computational results show that the species model agrees with experimental observations. This is the first time that the smouldering kinetics of SOM is explained and predicted, thus helping to understanding this important natural and widespread phenomenon.

An unusual cystic appearance of disseminated low-grade gliomas

International Nuclear Information System (INIS)

Huang, T.; Zimmerman, R.A.; Perilongo, G.; Kaufman, B.A.; Holden, K.R.; Carollo, C.; Kling Chong, W.K.

2001-01-01

We report five cases of pediatric disseminated low-grade gliomas of the brainstem or spinal cord that exhibited an unusual, cystic pattern. Leptomeningeal disease was present in three of these at diagnosis, and was detected shortly afterwards in the other two. Four patients are alive up to 5 years later, following minimal to no intervention, while one is dead. (orig.)

Line shape and thermal Kinetics analysis of the Fe2+ -band in Brazilian Green beryl

International Nuclear Information System (INIS)

Isotani, S.; Furtado, W.; Antonini, R.; Dias, O.L.

1988-03-01

The optical absorption spectra study through isothermal treatments of the σ- and Π-polarized bands of Fe 2+ -band is reported. It was shown a linear correlation between these bands through thermal treatments. Irradiation with γ-rays from 60 Co, showed the decrease of this band. The line shape analysis and the discussions lend us to assign the Π- and σ-polarized bands to Fe 2+ ions in the structural channels with and without neighbour water molecules, respectively. The kinetics analysis through a ''bimolecular-like'' model gives untrapping parameter with Arrhenius behavior. The retrapping and recombination parameters showed a behavior proportional to T 1/2 - T 1/2 o which were explained from free electron distribution of velocities and minimum untrapped electron energy due to a potential barrier of the trap. The kinetics cut-off temperature, T 0 , agrees with the previous experimental observation. (author) [pt

An unusual case of diffuse Merkel cell carcinoma successfully treated with low dose radiotherapy.

Science.gov (United States)

Chatzinasiou, Foteini; Papadavid, Euaggelia; Korkolopoulou, Penelope; Levidou, Georgia; Panayiotides, Ioannis; Theodoropoulos, Konstadinos; Pogka, Vasiliki; Asimakopoulos, Charalampos; Rigopoulos, Dimitrios

2015-01-01

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroendocrine carcinoma of the skin. MCC should be included in the diagnosis of a rapidly growing infiltrating mass and histology as well as laboratory investigations such as Merkel cell polyoma virus (MCPyV) detection are valuable in its diagnosis. We present an unusual case of giant MCC-positive MCPyV in a Greek woman located on the lower leg. Our patient is very unusual in terms of her extensive MCC and her rapid and complete response to radiotherapy. © 2015 Wiley Periodicals, Inc.

Explaining and accounting for moral order in news stories

DEFF Research Database (Denmark)

Svith, Flemming; Christensen, Lars Holmgaard

It is a premise for this paper that a key feature of storytelling and the construction of narratives, including those put forward by journalists, are their ability to translate the unusual and the abnormal into an intelligible form. (Bruner 1991) In journalism, a series of conventional standards...

An unusual presentation of multiple cavitated lung metastases from colon carcinoma

Directory of Open Access Journals (Sweden)

Iannace Alessandro

2011-05-01

Full Text Available Abstract Background Consolidation with or without ground-glass opacity is the typical radiologic finding of lung metastases of adenocarcinoma from the gastrointestinal tract. Lung excavated metastases from gastrointestinal carcinoma are very rare. Case presentation The authors describe an unusual presentation of multiple cavitated lung metastases from colon adenocarcinoma and discuss the outcome of a patient. The absence both of symptoms and other disease localizations, the investigations related to different diagnostic hypotheses and the empirical treatments caused a delay in correct diagnosis. Only a transparietal biopsy revealed the neoplastic origin of nodules. Conclusions This report demonstrates that although lung excavated metastases are described in literature, initial failure to reach a diagnosis is common. We would like to alert clinicians and radiologists to the possibility of unusual atypical features of pulmonary metastases from colon adenocarcinoma.

Myofibroblastoma: An Unusual Rapidly Growing Benign Tumour in a Male Breast

International Nuclear Information System (INIS)

Rafique, A.; Arshad, A.

2013-01-01

Myofibroblastoma is an unusual benign tumour of the breast predominantly seen in men in their sixth to seventh decade. The gross appearance is that of a well circumscribed nodule, characteristically small, seldom exceeding 3 cm. We present a case of an unusually large myofibroblastoma, which mimicked a malignant breast tumour. A 40 years old male, known case of tetralogy of Fallot, was operated in infancy in abroad, presented with a rapid enlargement of right breast over 5 - 6 weeks. Examination revealed a firm 10 cm hemispherical lump occupying the whole of the right breast with normal overlying skin. Since core biopsy was inconclusive, a subcutaneous mastectomy was performed to remove the tumour, which weighed 500 gms. Histopathology and immunocytochemistry revealed a mixed classical and collagenised type of myofibroblastoma. The patient is well with no evidence of recurrence. (author)

Osteosarcoma of the Maxilla: A Rare Case with Unusual Clinical Presentation

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Pouyan Amini Shakib

2013-08-01

Full Text Available Osteosarcoma (OS is a malignant mesenchymal tumor, which rarely occurs in the maxilla. Although variable histologic and radiographic features of OS have been reported previously, in the majority of the cases painful swelling of the jaw is mentioned as the first clinical presentation. Furthermore, early diagnosis and wide surgical resection of the tumor are the most important determinant factors of prognosis. Therefore, the unusual clinical presentations of OS should be considered meticulously to expedite the diagnosis process. We describe a case of OS of the maxilla with extremely unusual presentation in a 42-year-old female, that was initially designated as “epulis fissuratum”. Here, we highlight the importance of combining the clinical, radiographic and histopathologic examination to obtain a definitive diagnosis and also the significance of early effective surgical intervention in evaluation of pathologic lesions.

Unusual Case of Severe Lactic Acidosis in a Liver Transplant Patient

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Shweta Yemul Golhar

2017-01-01

Full Text Available Lactic acidosis is a standard indicator for oxygen debt and some other very significant causes. We describe a case of liver transplant patient presenting with vague abdominal pain and lactic acidosis without any liver dysfunction/failure/ischemia/rejection or sepsis. The imaging studies showed vague bowel edema and normal hepatic perfusion. The patient continued to deteriorate with rising lactic acidosis when a repeat CT abdomen eventually showed signs of lymphomatosis peritonei. Biopsy revealed the unusual diagnosis of posttransplant lymphoproliferative disorder. Immediate discontinuation of immunosuppression and initiation of chemotherapy led to clinical improvement. Our intention of presenting this case is to increase awareness of posttransplant lymphoma and propose lactic acidosis as not only an indicator of liver dysfunction or rejection but also an aid for diagnosis of this unusual but fatal and potentially curable condition.

Effects of reaction-kinetic parameters on modeling reaction pathways in GaN MOVPE growth

Science.gov (United States)

Zhang, Hong; Zuo, Ran; Zhang, Guoyi

2017-11-01

In the modeling of the reaction-transport process in GaN MOVPE growth, the selections of kinetic parameters (activation energy Ea and pre-exponential factor A) for gas reactions are quite uncertain, which cause uncertainties in both gas reaction path and growth rate. In this study, numerical modeling of the reaction-transport process for GaN MOVPE growth in a vertical rotating disk reactor is conducted with varying kinetic parameters for main reaction paths. By comparisons of the molar concentrations of major Ga-containing species and the growth rates, the effects of kinetic parameters on gas reaction paths are determined. The results show that, depending on the values of the kinetic parameters, the gas reaction path may be dominated either by adduct/amide formation path, or by TMG pyrolysis path, or by both. Although the reaction path varies with different kinetic parameters, the predicted growth rates change only slightly because the total transport rate of Ga-containing species to the substrate changes slightly with reaction paths. This explains why previous authors using different chemical models predicted growth rates close to the experiment values. By varying the pre-exponential factor for the amide trimerization, it is found that the more trimers are formed, the lower the growth rates are than the experimental value, which indicates that trimers are poor growth precursors, because of thermal diffusion effect caused by high temperature gradient. The effective order for the contribution of major species to growth rate is found as: pyrolysis species > amides > trimers. The study also shows that radical reactions have little effect on gas reaction path because of the generation and depletion of H radicals in the chain reactions when NH2 is considered as the end species.

Adenine phosphoribosyltransferase from Sulfolobus solfataricus is an enzyme with unusual kinetic properties and a crystal structure that suggests it evolved from a 6-oxopurine phosphoribosyltransferase

DEFF Research Database (Denmark)

Jensen, Kaj Frank; Hansen, Michael Riis; Jensen, Kristine Steen

2015-01-01

The adenine phosphoribosyltransferase (APRTase) encoded by the open reading frame SSO2342 of Sulfolobus solfataricus P2, was subjected to crystallographic, kinetic and ligand binding analyses. The enzyme forms dimers in solution and in the crystals, and binds one molecule of the reactants 5...

Complex reassortment events of unusual G9P[4] rotavirus strains in India between 2011 and 2013.

Science.gov (United States)

Doan, Yen Hai; Suzuki, Yoshiyuki; Fujii, Yoshiki; Haga, Kei; Fujimoto, Akira; Takai-Todaka, Reiko; Someya, Yuichi; Nayak, Mukti K; Mukherjee, Anupam; Imamura, Daisuke; Shinoda, Sumio; Chawla-Sarkar, Mamta; Katayama, Kazuhiko

2017-10-01

Rotavirus A (RVA) is the predominant etiological agent of acute gastroenteritis in young children worldwide. Recently, unusual G9P[4] rotavirus strains emerged with high prevalence in many countries. Such intergenogroup reassortant strains highlight the ongoing spread of unusual rotavirus strains throughout Asia. This study was undertaken to determine the whole genome of eleven unusual G9P[4] strains detected in India during 2011-2013, and to compare them with other human and animal global RVAs to understand the exact origin of unusual G9P[4] circulating in India and other countries worldwide. Of these 11 RVAs, four G9P[4] strains were double-reassortants with the G9-VP7 and E6-NSP4 genes on a DS-1-like genetic backbone (G9-P[4]-I2-R2-C2-M2-A2-N2-T2-E6-H2). The other strains showed a complex genetic constellation, likely derived from triple reassortment event with the G9-VP7, N1-NSP2 and E6-NSP4 on a DS-1-like genetic backbone (G9-P[4]-I2-R2-C2-M2-A2-N1-T2-E6-H2). Presumably, these unusual G9P[4] strains were generated after several reassortment events between the contemporary co-circulating human rotavirus strains. Moreover, the point mutation S291L at the interaction site between inner and outer capsid proteins of VP6 gene may be important in the rapid spread of this unusual strain. The complex reassortment events within the G9[4] strains may be related to the high prevalence of mixed infections in India as reported in this study and other previous studies. Copyright © 2017. Published by Elsevier B.V.

Using a toxicokinetics approach to explain the effect of soil pH on cadmium bioavailability to Folsomia candida

International Nuclear Information System (INIS)

Ardestani, Masoud M.; Gestel, Cornelis A.M. van

2013-01-01

The aim of this study was to improve our understanding of metal bioavailability in soil by linking the biotic ligand approach with toxicokinetics modelling. We determined cadmium bioaccumulation kinetics in Folsomia candida (Collembola) as a function of soil pH. Animals were exposed for 21 days to LUFA 2.2 soil at 5 or 20 μg Cd g −1 dry soil followed by 21 days elimination in clean soil. Internal cadmium concentrations were modelled using a first-order one-compartment model, relating uptake rate constants (k 1 ) to total soil, water or 0.01 M CaCl 2 extractable and porewater concentrations. Based on total soil concentrations, k 1 was independent of soil pH while it strongly increased with increasing pH based on porewater concentrations explaining the reduced competition of H + ions making cadmium more bioavailable in pore water at high pH. This shows that the principles of biotic ligand modelling are applicable to predict cadmium accumulation kinetics in soil-living invertebrates. -- Highlights: •Cadmium uptake and elimination in Folsomia candida were investigated. •Animals were exposed to LUFA 2.2 soil at different pH levels. •Langmuir isotherms were used to describe interaction of Ca and protons with Cd. •pH was the main factor affecting Cd toxicokinetics when pore water was considered. -- Integrating bioaccumulation kinetics with a BLM approach provides novel insights into the bioavailability of cadmium to springtails in soil

An unusual presentation of a malignant jejunal tumor and a different management strategy

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Parida Dillip K

2005-01-01

Full Text Available Abstract Background Malignant small bowel tumors are very rare and leiomyosarcoma accounts for less than 15% of the cases. Management of these tumors is challenging in view of nonspecific symptoms, unusual presentation and high incidence of metastasis. In this case report, an unusual presentation of jejunal sarcoma and management of liver metastasis with radiofrequency ablation (RFA is discussed. Case presentation A 45-year-old male presented with anemia and features of small bowel obstruction. Operative findings revealed a mass lesion in jejunum with intussusception of proximal loop. Resection of bowel mass was performed. Histopathological findings were suggestive of leiomyosarcoma. After 3-years of follow-up, the patient developed recurrence in infracolic omentum and a liver metastasis. The omental mass was resected and liver lesion was managed with radiofrequency ablation. Conclusion Jejunal leiomyosarcoma is a rare variety of malignant small bowel tumor and a clinical presentation with intussusception is unusual. We suggest that an aggressive management approach using a combination of surgery and a newer technique like RFA can be attempted in patients with limited metastatic spread to liver to prolong the long-term survival in a subset of patients.

Mycobacterium tuberculosis Rho is an NTPase with distinct kinetic properties and a novel RNA-binding subdomain.

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Anirban Mitra

Full Text Available Two mechanisms--factor independent and dependent termination--ensure the completion of RNA synthesis in eubacteria. Factor-dependent mechanism relies on the Rho protein to terminate transcription by interacting with RNA polymerase. Although well studied in Escherichia coli, the properties of the Rho homologs from most bacteria are not known. The rho gene is unusually large in genus Mycobacterium and other members of actinobacteria, having ∼150 additional residues towards the amino terminal end. We describe the distinct properties of Rho from Mycobacterium tuberculosis. It is an NTPase with a preference for purine nucleoside triphosphates with kinetic properties different from E. coli homolog and an ability to use various RNA substrates. The N-terminal subdomain of MtbRho can bind to RNA by itself, and appears to contribute to the interaction of the termination factor with RNAs. Furthermore, the interaction with RNA induces changes in conformation and oligomerization of MtbRho.

Metastasis of hepatocellular carcinoma to the heart: unusual patterns in three cases with antemortem diagnosis.

Science.gov (United States)

Lei, M H; Ko, Y L; Kuan, P; Lien, W P; Chen, D S

1992-04-01

Unusual patterns of cardiac metastasis were noted in three cases of hepatocellular carcinoma (HCC): one patient was noted to have a large right ventricular (RV) tumor mass with intracavitary growth and myocardial invasion; the second had massive pulmonary and left atrial (LA) metastasis; and the third patient had a right atrial tumor mass with concomitant RV and LA involvement. Tumor implantation to the RV without right atrial involvement and extensive myocardial invasion is unusual in HCC. The LA involvement is probably related to tumor growth from the pulmonary veins following massive metastasis to the lung, direct invasion of the atrial septum or tumor implantation via a subclinical right-to-left shunt through the patent foramen ovale. To the best of our knowledge, such unusual intracavitary metastases in HCC have not been reported previously. Cardiac metastasis, without local gross recurrence, may be one of the presentations after lobectomy in patients with HCC.

Cell respiration under hypoxia: facts and artefacts in mitochondrial oxygen kinetics.

Science.gov (United States)

Scandurra, Francesca M; Gnaiger, Erich

2010-01-01

When oxygen supply to tissues is limiting, mitochondrial respiration and ATP production are compromised. To assess the bioenergetic consequences under normoxia and hypoxia, quantitative evaluation of mitochondrial oxygen kinetics is required. Using high-resolution respirometry, the "apparent K (m)" for oxygen or p (50) of respiration in 32D cells was determined at 0.05 +/- 0.01 kPa (0.4 mmHg, 0.5 microM, 0.25% air saturation). Close agreement with p (50) of isolated mitochondria indicates that intracellular gradients are small in small cells at routine activity. At intracellular p (O2) respiration is limited by >2% with a p (50) of 0.05 kPa. Over-estimation of p (50) at 0.4 kPa (3 mmHg) would imply significant (>17%) oxygen limitation of respiration under intracellular normoxia. Based on a critical review, we conclude that p (50) ranges from 0.01 to 0.10 kPa in mitochondria and small cells in the absence of inhibitors of cytochrome c oxidase, whereas experimental artefacts explain the controversial >200-fold range of p (50) in the literature on mitochondrial oxygen kinetics.

Emergence of unusual species of enterococci causing infections, South India

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Rao Sambasiva R

2005-03-01

Full Text Available Abstract Background Enterococci tend to be one of the leading causes of nosocomial infections, with E. faecalis and E. faecium accounting up to 90% of the clinical isolates. Nevertheless, the incidence of other species of enterococci from clinical sources shows an alarming increase with the properties of intrinsic resistance to several antibiotics including beta-lactams and glycopeptides. Thus proper identification of enterococci to species level is quintessential for management and prevention of these bacteria in any healthcare facility. Hence this work was undertaken to study the prevalence of unusual species of enterococci causing human infections, in a tertiary care hospital in South India. Methods The study was conducted in a tertiary care hospital in South India from July 2001 to June 2003. Isolates of enterococci were collected from various clinical specimens and speciated using extensive phenotypic and physiological tests. Antimicrobial susceptibility testing were performed and interpreted as per NCCLS guidelines. Whole cell protein (WCP fingerprinting of enterococci were done for species validation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and analyzed computationally. Results Our study showed the prevalence of unusual (non-faecalis and non-faecium enterococci and atypical (biochemical variant species of enterococci as 19% (46 isolates and 5% (12 isolates respectively. The 7 unusual species (46 isolates isolated and confirmed by phenotypic characterization includes: 15 E. gallinarum (6.2%, 10 E. avium (4.1%, 6 E. raffinosus (2.5%, 6 E. hirae (2.5%, 4 E. mundtii (1.7%, 3 E. casseliflavus-including the two atypical isolates (1.2% and 2 E. durans (0.8%. The 12 atypical enterococcal species (5% that showed aberrant sugar reactions in conventional phenotyping were confirmed as E. faecalis, E. faecium and E. casseliflavus respectively by WCP fingerprinting. The antimicrobial susceptibility testing depicted the

Incidental discovery of an unusual right atrial membrane in an adult patient

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Nasrin N Aldawoodi

2012-01-01

Full Text Available We describe presence of an unusual right atrial membrane in a 30-year old female with end stage renal disease, hypertension and peripheral vascular disease. The patient was scheduled for midline sternotomy and pericardiotomy and removal of a migrated vascular stent in the right pulmonary artery. An intraoperative transesophageal echocardiogram (TEE revealed an unusual membranous structure with fenestrations that stretched across the right atrium with attachments superiorly at the free wall and inferiorly at the inter-atrial septum. There was no evidence of flow obstruction across the tricuspid valve. Some of the considerations for the likely diagnosis of this structure were a prominent Eustachian valve, persistent Chiari network, aneurysmal inter-atrial septum, an inter-atrial septal cyst or Cor triatriatum dexter (CTD.

Vlasov simulations of kinetic Alfvén waves at proton kinetic scales

Energy Technology Data Exchange (ETDEWEB)

Vásconez, C. L. [Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza (Italy); Observatorio Astronómico de Quito, Escuela Politécnica Nacional, Quito (Ecuador); Valentini, F.; Veltri, P. [Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza (Italy); Camporeale, E. [Centrum Wiskunde and Informatica, Amsterdam (Netherlands)

2014-11-15

Kinetic Alfvén waves represent an important subject in space plasma physics, since they are thought to play a crucial role in the development of the turbulent energy cascade in the solar wind plasma at short wavelengths (of the order of the proton gyro radius ρ{sub p} and/or inertial length d{sub p} and beyond). A full understanding of the physical mechanisms which govern the kinetic plasma dynamics at these scales can provide important clues on the problem of the turbulent dissipation and heating in collisionless systems. In this paper, hybrid Vlasov-Maxwell simulations are employed to analyze in detail the features of the kinetic Alfvén waves at proton kinetic scales, in typical conditions of the solar wind environment (proton plasma beta β{sub p} = 1). In particular, linear and nonlinear regimes of propagation of these fluctuations have been investigated in a single-wave situation, focusing on the physical processes of collisionless Landau damping and wave-particle resonant interaction. Interestingly, since for wavelengths close to d{sub p} and β{sub p} ≃ 1 (for which ρ{sub p} ≃ d{sub p}) the kinetic Alfvén waves have small phase speed compared to the proton thermal velocity, wave-particle interaction processes produce significant deformations in the core of the particle velocity distribution, appearing as phase space vortices and resulting in flat-top velocity profiles. Moreover, as the Eulerian hybrid Vlasov-Maxwell algorithm allows for a clean almost noise-free description of the velocity space, three-dimensional plots of the proton velocity distribution help to emphasize how the plasma departs from the Maxwellian configuration of thermodynamic equilibrium due to nonlinear kinetic effects.

A GIANT CONGENITAL ORBITAL TUMOR - AN UNUSUAL PRESENTATION OF RETINOBLASTOMA

NARCIS (Netherlands)

ZWAAN, CM; DEWAAL, FC; KOOLE, FD; MENKO, FH; VANDERVALK, P; SLATER, RM; SCHEFFER, H; VANWAVEREN, G; MOLL, AC; SCHOUTENVANMEETEREN, AYN; TAN, KEWP

1994-01-01

We report a case of an unusual giant congential tumor presenting in a newborn infant as a large exophytic mass emerging from the left orbit. After enucleation orbital recurrence developed within 14 days. No anti-tumor treatment was given and the child died at the age of 4 weeks. The

An unusual case of Trisomy 13 | Feben | South African Journal of ...

African Journals Online (AJOL)

Trisomy 13 is a common chromosome abnormality with a recognisable clinical phenotype, which should prompt its early diagnosis. This case report describes a patient with Trisomy 13 with unusual limb malformations and expands on the clinical phenotype of the disorder.

Chemical kinetics and reaction mechanism

International Nuclear Information System (INIS)

Jung, Ou Sik; Park, Youn Yeol

1996-12-01

This book is about chemical kinetics and reaction mechanism. It consists of eleven chapters, which deal with reaction and reaction speed on reaction mechanism, simple reaction by rate expression, reversible reaction and simultaneous reaction, successive reaction, complicated reaction mechanism, assumption for reaction mechanism, transition state theory, successive reaction and oscillating reaction, reaction by solution, research method high except kinetics on reaction mechanism, high reaction of kinetics like pulsed radiolysis.

Suppression of Phase Mixing in Drift-Kinetic Plasma Turbulence

Science.gov (United States)

Parker, J. T.; Dellar, P. J.; Schekochihin, A. A.; Highcock, E. G.

2017-12-01

of free energy flow in drift-kinetic turbulence, and, moreover, explain previously observed spectra.

Kinetic modelling of enzymatic starch hydrolysis

NARCIS (Netherlands)

Bednarska, K.A.

2015-01-01

Kinetic modelling of enzymatic starch hydrolysis – a summary

K.A. Bednarska

The dissertation entitled ‘Kinetic modelling of enzymatic starch hydrolysis’ describes the enzymatic hydrolysis and kinetic modelling of liquefaction and saccharification of wheat starch.

Primary sacrococcygeal chordoma with unusual skeletal muscle metastasis

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Lisa Vu, MD

2014-01-01

Full Text Available Chordomas are rare neoplasms that do not often metastasize. Of the small percent that do metastasize, they very infrequently involve skeletal muscle. Only a few cases of skeletal muscle metastases have been reported in the literature. We report an unusual case of a patient with a primary sacrococcygeal chordoma who experienced a long period of remission but who subsequently developed recurrence and multiple metastatic lesions to skeletal muscles including the deltoid, triceps, and pectineus.

Fusion or gemination? An unusual mandibular second molar

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Angela Jordão Camargo

2016-01-01

Full Text Available Fusion and gemination is not an uncommon finding and affected most primary dentition and the permanent maxillary incisors. These changes can develop a series of complication. A 11-year-old male presented radiography finding: an unusual mandibular second molar. A well-documented case brings a challenge for radiologists classify between fusion and gemination. In conclusion, this alteration although common in other regions, there are no case in the literature involving “second and third” molar.

Synthetic spectral analysis of a kinetic model for slow-magnetosonic waves in solar corona

Energy Technology Data Exchange (ETDEWEB)

Ruan, Wenzhi; He, Jiansen; Tu, Chuanyi; Wang, Linghua [School of Earth and Space Sciences, Peking University, Beijing, 100871, China, E-mail: jshept@gmail.com (China); Zhang, Lei [State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100190 (China); Vocks, Christian [Leibniz-Institut für Astrophysik Potsdam, 14482, Potsdam (Germany); Marsch, Eckart [Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, 24118 Kiel (Germany); Peter, Hardi [Max Plank Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen (Germany)

2016-03-25

We propose a kinetic model of slow-magnetosonic waves to explain various observational features associated with the propagating intensity disturbances (PIDs) occurring in the solar corona. The characteristics of slow mode waves, e.g, inphase oscillations of density, velocity, and thermal speed, are reproduced in this kinetic model. Moreover, the red-blue (R-B) asymmetry of the velocity distribution as self-consistently generated in the model is found to be contributed from the beam component, as a result of the competition between Landau resonance and Coulomb collisions. Furthermore, we synthesize the spectral lines and make the spectral analysis, based on the kinetic simulation data of the flux tube plasmas and the hypothesis of the surrounding background plasmas. It is found that the fluctuations of parameters of the synthetic spectral lines are basically consistent with the observations: (1) the line intensity, Doppler shift, and line width are fluctuating in phase; (2) the R-B asymmetry usually oscillate out of phase with the former three parameters; (3) the blueward asymmetry is more evident than the redward asymmetry in the R-B fluctuations. The oscillations of line parameters become weakened for the case with denser surrounding background plasmas. Similar to the observations, there is no doubled-frequency oscillation of the line width for the case with flux-tube plasmas flowing bulkly upward among the static background plasmas. Therefore, we suggest that the “wave + beam flow” kinetic model may be a viable interpretation for the PIDs observed in the solar corona.

Stepwise kinetic equilibrium models of quantitative polymerase chain reaction

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Cobbs Gary

2012-08-01

literature. They also give better estimates of initial target concentration. Model 1 was found to be slightly more robust than model 2 giving better estimates of initial target concentration when estimation of parameters was done for qPCR curves with very different initial target concentration. Both models may be used to estimate the initial absolute concentration of target sequence when a standard curve is not available. Conclusions It is argued that the kinetic approach to modeling and interpreting quantitative PCR data has the potential to give more precise estimates of the true initial target concentrations than other methods currently used for analysis of qPCR data. The two models presented here give a unified model of the qPCR process in that they explain the shape of the qPCR curve for a wide variety of initial target concentrations.

Stepwise kinetic equilibrium models of quantitative polymerase chain reaction.

Science.gov (United States)

Cobbs, Gary

2012-08-16

initial target concentration. Model 1 was found to be slightly more robust than model 2 giving better estimates of initial target concentration when estimation of parameters was done for qPCR curves with very different initial target concentration. Both models may be used to estimate the initial absolute concentration of target sequence when a standard curve is not available. It is argued that the kinetic approach to modeling and interpreting quantitative PCR data has the potential to give more precise estimates of the true initial target concentrations than other methods currently used for analysis of qPCR data. The two models presented here give a unified model of the qPCR process in that they explain the shape of the qPCR curve for a wide variety of initial target concentrations.

A critical look at the kinetic models of thermoluminescence-II. Non-first order kinetics

International Nuclear Information System (INIS)

Sunta, C M; Ayta, W E F; Chubaci, J F D; Watanabe, S

2005-01-01

Non-first order (FO) kinetics models are of three types; second order (SO), general order (GO) and mixed order (MO). It is shown that all three of these have constraints in their energy level schemes and their applicable parameter values. In nature such restrictions are not expected to exist. The thermoluminescence (TL) glow peaks produced by these models shift their position and change their shape as the trap occupancies change. Such characteristics are very unlike those found in samples of real materials. In these models, in general, retrapping predominates over recombination. It is shown that the quasi-equilibrium (QE) assumption implied in the derivation of the TL equation of these models is quite valid, thus disproving earlier workers' conclusion that QE cannot be held under retrapping dominant conditions. However notwithstanding their validity, they suffer from the shortcomings as stated above and have certain lacunae. For example, the kinetic order (KO) parameter and the pre-exponential factor which are assumed to be the constant parameters of the GO kinetics expression turn out to be variables when this expression is applied to plausible physical models. Further, in glow peak characterization using the GO expression, the quality of fit is found to deteriorate when the best fitted value of KO parameter is different from 1 and 2. This means that the found value of the basic parameter, namely the activation energy, becomes subject to error. In the MO kinetics model, the value of the KO parameter α would change with dose, and thus in this model also, as in the GO model, no single value of KO can be assigned to a given glow peak. The paper discusses TL of real materials having characteristics typically like those of FO kinetics. Theoretically too, a plausible physical model of TL emission produces glow peaks which have characteristics of FO kinetics under a wide variety of parametric combinations. In the background of the above findings, it is suggested that

Fluorescence kinetics and positron annihilation kinetics investigations in cadmium sulfide crystals

Energy Technology Data Exchange (ETDEWEB)

Grillot, E; Bancie-Grillot, M; Egee, M [Reims Univ., 51 (France)

1976-03-01

Fluorescence kinetics and positrons annihilation kinetics investigations on CdS crystals, either very pure or with increasing contents of Ag-ions, led to similar and complementary results. Ag-ions mainly fill the cadmium vacancies of the lattice, building red emission luminogene centres, while green 'edge-emission' ones are destroyed. These latter, which involve an excited level active for high energy series fluorescence, seems actually related to cadmium vacancies.

Mathematical modeling provides kinetic details of the human immune response to vaccination

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Dustin eLe

2015-01-01

Full Text Available With major advances in experimental techniques to track antigen-specific immune responses many basic questions on the kinetics of virus-specific immunity in humans remain unanswered. To gain insights into kinetics of T and B cell responses in human volunteers we combine mathematical models and experimental data from recent studies employing vaccines against yellow fever and smallpox. Yellow fever virus-specific CD8 T cell population expanded slowly with the average doubling time of 2 days peaking 2.5 weeks post immunization. Interestingly, we found that the peak of the yellow fever-specific CD8 T cell response is determined by the rate of T cell proliferation and not by the precursor frequency of antigen-specific cells as has been suggested in several studies in mice. We also found that while the frequency of virus-specific T cells increases slowly, the slow increase can still accurately explain clearance of yellow fever virus in the blood. Our additional mathematical model describes well the kinetics of virus-specific antibody-secreting cell and antibody response to vaccinia virus in vaccinated individuals suggesting that most of antibodies in 3 months post immunization are derived from the population of circulating antibody-secreting cells. Taken together, our analysis provides novel insights into mechanisms by which live vaccines induce immunity to viral infections and highlight challenges of applying methods of mathematical modeling to the current, state-of-the-art yet limited immunological data.

Mathematical modeling provides kinetic details of the human immune response to vaccination.

Science.gov (United States)

Le, Dustin; Miller, Joseph D; Ganusov, Vitaly V

2014-01-01

With major advances in experimental techniques to track antigen-specific immune responses many basic questions on the kinetics of virus-specific immunity in humans remain unanswered. To gain insights into kinetics of T and B cell responses in human volunteers we combined mathematical models and experimental data from recent studies employing vaccines against yellow fever and smallpox. Yellow fever virus-specific CD8 T cell population expanded slowly with the average doubling time of 2 days peaking 2.5 weeks post immunization. Interestingly, we found that the peak of the yellow fever-specific CD8 T cell response was determined by the rate of T cell proliferation and not by the precursor frequency of antigen-specific cells as has been suggested in several studies in mice. We also found that while the frequency of virus-specific T cells increased slowly, the slow increase could still accurately explain clearance of yellow fever virus in the blood. Our additional mathematical model described well the kinetics of virus-specific antibody-secreting cell and antibody response to vaccinia virus in vaccinated individuals suggesting that most of antibodies in 3 months post immunization were derived from the population of circulating antibody-secreting cells. Taken together, our analysis provided novel insights into mechanisms by which live vaccines induce immunity to viral infections and highlighted challenges of applying methods of mathematical modeling to the current, state-of-the-art yet limited immunological data.

Tropical parabiotic ants: Highly unusual cuticular substances and low interspecific discrimination

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Schmitt Thomas

2008-10-01

Full Text Available Abstract Background Associations between animal species require that at least one of the species recognizes its partner. Parabioses are associations of two ant species which co-inhabit the same nest. Ants usually possess an elaborate nestmate recognition system, which is based on cuticular hydrocarbons and allows them to distinguish nestmates from non-nestmates through quantitative or qualitative differences in the hydrocarbon composition. Hence, living in a parabiotic association probably necessitates changes of the nestmate recognition system in both species, since heterospecific ants have to be accepted as nestmates. Results In the present study we report highly unusual cuticular profiles in the parabiotic species Crematogaster modiglianii and Camponotus rufifemur from the tropical rainforest of Borneo. The cuticle of both species is covered by a set of steroids, which are highly unusual surface compounds. They also occur in the Dufour gland of Crematogaster modiglianii in high quantities. The composition of these steroids differed between colonies but was highly similar among the two species of a parabiotic nest. In contrast, hydrocarbon composition of Cr. modiglianii and Ca. rufifemur differed strongly and only overlapped in three regularly occurring and three trace compounds. The hydrocarbon profile of Camponotus rufifemur consisted almost exclusively of methyl-branched alkenes of unusually high chain lengths (up to C49. This species occurred in two sympatric, chemically distinct varieties with almost no hydrocarbons in common. Cr. modiglianii discriminated between these two varieties. It only tolerated workers of the Ca. rufifemur variety it was associated with, but attacked the respective others. However, Cr. modiglianii did not distinguish its own Ca. rufifemur partner from allocolonial Ca. rufifemur workers of the same variety. Conclusion We conclude that there is a mutual substance transfer between Cr. modiglianii and Ca. rufifemur

Unusual Surprises in Glaucoma Filtering Surgeries: Lessons Learned and Review of Literature.

Science.gov (United States)

Rao, Aparna; Padhy, Debananda; Roy, Avik Kumar; Senthil, Sirisha

2018-01-01

To describe an unusual series of complications after glaucoma filtering surgeries with their clinical findings and outcome after tailored non-conventional modes of therapy. Eighteen patients who underwent re-interventions (medical or surgical) after glaucoma filtering surgeries during the period at two tertiary centers, excluding those that required conventional modes of treatment (medical control or re-trabeculectomy, simple wound closure for traumatic wound dehiscence, bleb revision or needling, laser iridotomy), were included. Relevant clinical details with intraoperative videos, intraoperative or postoperative problems, and images with course after re-intervention were retrieved from the hospital database. Clinical details which helped in clinching diagnosis and cause for problems and course after intervention with final vision and intraocular pressure were evaluated. Six of 18 eyes required surgical management for an unusual course of events after an uneventful filtering surgery. Bleb morphology and close follow-up of the conjunctiva, in addition to intraocular pressure (IOP) and anterior chamber (AC) configuration, helped diagnose possible aetiology and appropriate tailored management. All patients had good IOP and visual outcome in all except one with macular scar status after retinal detachment surgery. Assessment of the bleb morphology in the postoperative course coupled with monitoring of the conjunctival wound are essential to conventional monitoring of IOP and anterior chamber configuration to arrive at appropriate management for rare unusual events after glaucoma surgery.

External cystic rectal duplication: an unusual presentation of rectal duplication cyst.

Science.gov (United States)

Karaman, I; Karaman, A; Arda, N; Cakmak, O

2007-11-01

Duplications of gastrointestinal tract are rare anomalies, and rectal duplications account for five percent of the alimentary tract duplications. We present an unusual case of rectal duplication, which was located externally in a newborn female, and discuss the types of distal hindgut duplications.

Rabbitfish ("aras"): an unusual source of ciguatera poisoning.

Science.gov (United States)

Raikhlin-Eisenkraft, Bianca; Bentur, Yedidia

2002-01-01

Ciguatera poisoning is the commonest fish-borne seafood intoxication. It is endemic to warm water tropical areas and is caused by consumption of bottom-dwelling shore reef fish, mostly during spring and summer. The causative agent, ciguatoxin, is a heat-stable ester complex that becomes concentrated in fish feeding on toxic dinoflagellates. The common clinical manifestations are a combination of gastrointestinal and neurologic symptoms. Severe poisoning may be associated with seizures and respiratory paralysis. To describe a series of patients who sustained ciguatera poisoning in an uncommon region and from an unexpected source. Two families complained of a sensation of "electrical currents," tremors, muscle cramps, nightmares, hallucinations, agitation, anxiety and nausea of varying severity several hours after consuming rabbitfish ("aras"). These symptoms lasted between 12 and 30 hours and resolved completely. The temporal relationship to a summer fish meal, the typical clinical manifestations along with the known feeding pattern of the rabbitfish suggested ciguatera poisoning. The Eastern Mediterranean basin is an unusual region and the rabbitfish an unusual source for ciguatera poisoning. There are no readily available and reliable means for detecting ciguatoxin in humans. A high index of suspicion is needed for diagnosis and a thorough differential diagnosis is essential to eliminate other poisonings, decompression sickness and encephalitis. Supportive therapy is the mainstay of treatment.

PAK4 crystal structures suggest unusual kinase conformational movements.

Science.gov (United States)

Zhang, Eric Y; Ha, Byung Hak; Boggon, Titus J

2018-02-01

In order for protein kinases to exchange nucleotide they must open and close their catalytic cleft. These motions are associated with rotations of the N-lobe, predominantly around the 'hinge region'. We conducted an analysis of 28 crystal structures of the serine-threonine kinase, p21-activated kinase 4 (PAK4), including three newly determined structures in complex with staurosporine, FRAX486, and fasudil (HA-1077). We find an unusual motion between the N-lobe and C-lobe of PAK4 that manifests as a partial unwinding of helix αC. Principal component analysis of the crystal structures rationalizes these movements into three major states, and analysis of the kinase hydrophobic spines indicates concerted movements that create an accessible back pocket cavity. The conformational changes that we observe for PAK4 differ from previous descriptions of kinase motions, and although we observe these differences in crystal structures there is the possibility that the movements observed may suggest a diversity of kinase conformational changes associated with regulation. Protein kinases are key signaling proteins, and are important drug targets, therefore understanding their regulation is important for both basic research and clinical points of view. In this study, we observe unusual conformational 'hinging' for protein kinases. Hinging, the opening and closing of the kinase sub-domains to allow nucleotide binding and release, is critical for proper kinase regulation and for targeted drug discovery. We determine new crystal structures of PAK4, an important Rho-effector kinase, and conduct analyses of these and previously determined structures. We find that PAK4 crystal structures can be classified into specific conformational groups, and that these groups are associated with previously unobserved hinging motions and an unusual conformation for the kinase hydrophobic core. Our findings therefore indicate that there may be a diversity of kinase hinging motions, and that these may

New Methods for Processing and Quantifying VO2 Kinetics to Steady State: VO2 Onset Kinetics

Directory of Open Access Journals (Sweden)

Craig R. McNulty

2017-09-01

Full Text Available Current methods of oxygen uptake (VO2 kinetics data handling may be too simplistic for the complex physiology involved in the underlying physiological processes. Therefore, the aim of this study was to quantify the VO2 kinetics to steady state across the full range of sub-ventilatory threshold work rates, with a particular focus on the VO2 onset kinetics. Ten healthy, moderately trained males participated in five bouts of cycling. Each bout involved 10 min at a percentage of the subject's ventilation threshold (30, 45, 60, 75, 90% from unloaded cycling. The VO2 kinetics was quantified using the conventional mono-exponential time constant (tau, τ, as well as the new methods for VO2 onset kinetics. Compared to linear modeling, non-linear modeling caused a deterioration of goodness of fit (main effect, p < 0.001 across all exercise intensities. Remainder kinetics were also improved using a modified application of the mono-exponential model (main effect, p < 0.001. Interestingly, the slope from the linear regression of the onset kinetics data is similar across all subjects and absolute exercise intensities, and thereby independent of subject fitness and τ. This could indicate that there are no functional limitations between subjects during this onset phase, with limitations occurring for the latter transition to steady state. Finally, the continuing use of mono-exponential modeling could mask important underlying physiology of more instantaneous VO2 responses to steady state. Consequently, further research should be conducted on this new approach to VO2 onset kinetics.

Logarithmic Exchange Kinetics in Monodisperse Copolymeric Micelles

Science.gov (United States)

García Daza, Fabián A.; Bonet Avalos, Josep; Mackie, Allan D.

2017-06-01

Experimental measurements of the relaxation kinetics of copolymeric surfactant exchange for micellar systems unexpectedly show a peculiar logarithmic decay. Several authors use polydispersity as an explanation for this behavior. However, in coarse-grained simulations that preserve microscopic details of the surfactants, we find evidence of the same logarithmic behavior. Since we use a strictly monodisperse distribution of chain lengths such a relaxation process cannot be attributed to polydispersity, but has to be caused by an inherent physical process characteristic of this type of system. This is supported by the fact that the decay is specifically logarithmic and not a power law with an exponent inherited from the particular polydispersity distribution of the sample. We suggest that the degeneracy of the energy states of the hydrophobic block in the core, which is broken on leaving the micelle, can qualitatively explain the broad distribution of energy barriers, which gives rise to the observed nonexponential relaxation.

Kinetic rates and mass balance of COD, TKN, and TP using SBR treating domestic and industrial wastewater.

Science.gov (United States)

Warodomrungsimun, Chaowalit; Fongsatitkul, Prayoon

2009-12-01

To assess the performance of SBR to treat three different types of wastewater from domestic, hospital, slaughterhouse and investigate the kinetic rates of active biomass. Mass balance calculation of COD, TKN and TP was further performed to explain the mechanisms of the biological nutrient removals processed in the SBR system. The measured kinetic rates were in turn used to evaluate the process performances under different types of wastewater. Experimental research involving 3 similar SBR lab-scales were installed and operated at the Sanitary Engineering Laboratory. The reactors were seeded with sludge biomass obtained from the Sri-Phraya Domestic Wastewater Treatment Plant in Bangkok. The slaughterhouse, hospital and domestic wastewaters were treated by SBR system for biological organic carbon (COD), nitrogen (TKN) and phosphorus removals. Biological methods for kinetic rates evaluation were conducted in five replicated batch tests. The removal efficiencies of COD and TKN were greater than 90% for all three types of wastewater while the biological phosphorus removal for domestic and hospital wastewaters were less than 60% and phosphorus removal for slaughterhouse exceeded 95%. The kinetic rates of nitrification and denitrification of hospital wastewater was lower than those the domestic and slaughterhouse wastewaters. Phosphorus release and uptake rates of slaughterhouse wastewater were high but domestic and hospital wastewaters were very low. The result of system removal efficiency and batch test for kinetic rates confirmed that the domestic and hospital wastewaters were in deficiency of organic carbon with respect to its ability to support successful biological phosphorus removal.

Influence of excited molecules on electron swarm transport coefficients and gas discharge kinetics

International Nuclear Information System (INIS)

Petrovic, Z.L.; Jovanovic, J.V.; Raspopovic, Z.M.; Bzenic, S.A.; Vrhovac, S.B.

1997-01-01

In this paper we study different effects of excited molecules on swarm parameters, electron energy distribution functions and gas discharge modeling. First we discuss a possible experiment in parahydrogen to resolve the discrepancy in hydrogen vibrational excitation cross section data. Negative differential conductivity (NDC) is a kinetic phenomenon which manifests itself in a particular dependence of the drift velocity on E=N and it is affected by superelastic collisions with excited states. A complete kinetic scheme for argon required to model excited state densities in gas discharges is also described. These results are used to explain experiments in capacitively and inductively coupled RF plasmas used for processing. The paper illustrates the application of atomic and molecular collision data, swarm data and the theoretical techniques in modeling of gas discharges with large abundances of excited molecules. It is pointed out that swarm experiments with excited molecules are lacking and that there is a shortage of reliable data, while the numerical procedures are sufficiently developed to include all the important effects. (authors). 59 refs., 12 figs

Kinetics of YBa2Cu3O6+γ oxidation

International Nuclear Information System (INIS)

Mozhaev, A.P.; Chernyaev, S.V.; Udal'tsova, T.I.; Kotov, N.M.

1992-01-01

Kinetics of the processes taking place during thermal treatment of YBa 2 Cu 3 O 6+γ samples and change in oxygen nonstoichiometry, related to the processes, were studied. The coefficient of oxygen diffusion was determined (D=D 0 x exp x (-E α /RT) a = 118 kJ/mol, D 0 = 4x10 -6 m 2 /s), which gave a satisfactory description of behaviour of powders and ceramics with the density below 5200 kg/m 3 . It is shown that in the course of annealing of denser samples considerable deviations of the calculated curves γ(T) from the experimental ones are observed. The deviations mentioned can be explained by the appearance of closed porosity and additional diffusion impediments

Enterovirus 71-related encephalomyelitis: usual and unusual magnetic resonance imaging findings

International Nuclear Information System (INIS)

Jang, Seonah; Suh, Sang-Il; Ha, Su Min; Seol, Hae-Young; Byeon, Jung Hye; Eun, Baik-Lin; Lee, Young Hen; Seo, Hyung Suk; Eun, So-Hee

2012-01-01

Most enterovirus (EV) 71 infections manifest as mild cases of hand-foot-mouth disease (HFMD)/herpangina with seasonal variations, having peak incidence during the summer. Meanwhile, EV 71 may involve the central nervous system (CNS), causing severe neurologic disease. In many cases, enteroviral encephalomyelitis involves the central midbrain, posterior portion of the medulla oblongata and pons, bilateral dentate nuclei of the cerebellum, and the ventral roots of the cervical spinal cord, and the lesions show hyperintensity on T2-weighted and fluid-attenuation inversion recovery (FLAIR) images. Our goal was to review usual and unusual magnetic resonance (MR) findings in CNS involvement of enteroviral infection. Among consecutive patients who had HFMD and clinically suspected encephalitis or myelitis and who underwent brain or spinal MR imaging, five patients revealed abnormal MR findings. Diffusion-weighted and conventional MR and follow-up MR images were obtained. From cerebrospinal fluid, stool, or nasopharyngeal swabs, EV 71 was confirmed in all patients. MR imaging studies of two patients showed hyperintensity in the posterior portion of the brainstem on T2-weighted and FLAIR images, which is the well-known MR finding of EV 71 encephalitis. The remaining three cases revealed unusual manifestations: leptomeningeal enhancement, abnormal enhancement along the ventral roots at the conus medullaris level without brain involvement, and hyperintensity in the left hippocampus on T2/FLAIR images. EV 71 encephalomyelitis shows relatively characteristic MR findings; therefore, imaging can be helpful in radiologic diagnosis. However, physicians should also be aware of unusual radiologic manifestations of EV 71. (orig.)

Enterovirus 71-related encephalomyelitis: usual and unusual magnetic resonance imaging findings

Energy Technology Data Exchange (ETDEWEB)

Jang, Seonah; Suh, Sang-Il; Ha, Su Min; Seol, Hae-Young [Korea University Guro Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Byeon, Jung Hye; Eun, Baik-Lin [Korea University Guro Hospital, Korea University College of Medicine, Department of Pediatrics, Seoul (Korea, Republic of); Lee, Young Hen; Seo, Hyung Suk [Korea University Ansan Hospital, Korea University College of Medicine, Department of Radiology, Ansan (Korea, Republic of); Eun, So-Hee [Korea University Ansan Hospital, Korea University College of Medicine, Department of Pediatrics, Ansan (Korea, Republic of)

2012-03-15

Most enterovirus (EV) 71 infections manifest as mild cases of hand-foot-mouth disease (HFMD)/herpangina with seasonal variations, having peak incidence during the summer. Meanwhile, EV 71 may involve the central nervous system (CNS), causing severe neurologic disease. In many cases, enteroviral encephalomyelitis involves the central midbrain, posterior portion of the medulla oblongata and pons, bilateral dentate nuclei of the cerebellum, and the ventral roots of the cervical spinal cord, and the lesions show hyperintensity on T2-weighted and fluid-attenuation inversion recovery (FLAIR) images. Our goal was to review usual and unusual magnetic resonance (MR) findings in CNS involvement of enteroviral infection. Among consecutive patients who had HFMD and clinically suspected encephalitis or myelitis and who underwent brain or spinal MR imaging, five patients revealed abnormal MR findings. Diffusion-weighted and conventional MR and follow-up MR images were obtained. From cerebrospinal fluid, stool, or nasopharyngeal swabs, EV 71 was confirmed in all patients. MR imaging studies of two patients showed hyperintensity in the posterior portion of the brainstem on T2-weighted and FLAIR images, which is the well-known MR finding of EV 71 encephalitis. The remaining three cases revealed unusual manifestations: leptomeningeal enhancement, abnormal enhancement along the ventral roots at the conus medullaris level without brain involvement, and hyperintensity in the left hippocampus on T2/FLAIR images. EV 71 encephalomyelitis shows relatively characteristic MR findings; therefore, imaging can be helpful in radiologic diagnosis. However, physicians should also be aware of unusual radiologic manifestations of EV 71. (orig.)

Unusual ratio between free thyroxine and free triiodothyronine in a long-lived mole-rat species with bimodal ageing.

Directory of Open Access Journals (Sweden)

Yoshiyuki Henning

Full Text Available Ansell's mole-rats (Fukomys anselli are subterranean, long-lived rodents, which live in eusocial families, where the maximum lifespan of breeders is twice as long as that of non-breeders. Their metabolic rate is significantly lower than expected based on allometry, and their retinae show a high density of S-cone opsins. Both features may indicate naturally low thyroid hormone levels. In the present study, we sequenced several major components of the thyroid hormone pathways and analyzed free and total thyroxine and triiodothyronine in serum samples of breeding and non-breeding F. anselli to examine whether a their thyroid hormone system shows any peculiarities on the genetic level, b these animals have lower hormone levels compared to euthyroid rodents (rats and guinea pigs, and c reproductive status, lifespan and free hormone levels are correlated. Genetic analyses confirmed that Ansell's mole-rats have a conserved thyroid hormone system as known from other mammalian species. Interspecific comparisons revealed that free thyroxine levels of F. anselli were about ten times lower than of guinea pigs and rats, whereas the free triiodothyronine levels, the main biologically active form, did not differ significantly amongst species. The resulting fT4:fT3 ratio is unusual for a mammal and potentially represents a case of natural hypothyroxinemia. Comparisons with total thyroxine levels suggest that mole-rats seem to possess two distinct mechanisms that work hand in hand to downregulate fT4 levels reliably. We could not find any correlation between free hormone levels and reproductive status, gender or weight. Free thyroxine may slightly increase with age, based on sub-significant evidence. Hence, thyroid hormones do not seem to explain the different ageing rates of breeders and non-breeders. Further research is required to investigate the regulatory mechanisms responsible for the unusual proportion of free thyroxine and free triiodothyronine.

Unusual ratio between free thyroxine and free triiodothyronine in a long-lived mole-rat species with bimodal ageing.

Science.gov (United States)

Henning, Yoshiyuki; Vole, Christiane; Begall, Sabine; Bens, Martin; Broecker-Preuss, Martina; Sahm, Arne; Szafranski, Karol; Burda, Hynek; Dammann, Philip

2014-01-01

Ansell's mole-rats (Fukomys anselli) are subterranean, long-lived rodents, which live in eusocial families, where the maximum lifespan of breeders is twice as long as that of non-breeders. Their metabolic rate is significantly lower than expected based on allometry, and their retinae show a high density of S-cone opsins. Both features may indicate naturally low thyroid hormone levels. In the present study, we sequenced several major components of the thyroid hormone pathways and analyzed free and total thyroxine and triiodothyronine in serum samples of breeding and non-breeding F. anselli to examine whether a) their thyroid hormone system shows any peculiarities on the genetic level, b) these animals have lower hormone levels compared to euthyroid rodents (rats and guinea pigs), and c) reproductive status, lifespan and free hormone levels are correlated. Genetic analyses confirmed that Ansell's mole-rats have a conserved thyroid hormone system as known from other mammalian species. Interspecific comparisons revealed that free thyroxine levels of F. anselli were about ten times lower than of guinea pigs and rats, whereas the free triiodothyronine levels, the main biologically active form, did not differ significantly amongst species. The resulting fT4:fT3 ratio is unusual for a mammal and potentially represents a case of natural hypothyroxinemia. Comparisons with total thyroxine levels suggest that mole-rats seem to possess two distinct mechanisms that work hand in hand to downregulate fT4 levels reliably. We could not find any correlation between free hormone levels and reproductive status, gender or weight. Free thyroxine may slightly increase with age, based on sub-significant evidence. Hence, thyroid hormones do not seem to explain the different ageing rates of breeders and non-breeders. Further research is required to investigate the regulatory mechanisms responsible for the unusual proportion of free thyroxine and free triiodothyronine.

Unusual structural transition of antimicrobial VP1 peptide.

Science.gov (United States)

Shanmugam, Ganesh; Phambu, Nsoki; Polavarapu, Prasad L

2011-05-01

VP1 peptide, an active domain of m-calpain enzyme with antimicrobial activity is found to undergo an unusual conformational transition in trifluoroethanol (TFE) solvent. The nature of, and time dependent variations in, circular dichroism associated with the amide I vibrations, suggest that VP1 undergoes self-aggregation forming anti-parallel β-sheet structure in TFE. Transmission electron micrograph (TEM) images revealed that β-sheet aggregates formed by VP1 possess fibril-like assemblies. Copyright © 2011 Elsevier B.V. All rights reserved.

The cruel and unusual phenomenology of solitary confinement

OpenAIRE

Shaun eGallagher; Shaun eGallagher; Shaun eGallagher

2014-01-01

What happens when subjects are deprived of intersubjective contact? This paper looks closely at the phenomenology and psychology of one example of that deprivation: solitary confinement. It also puts the phenomenology and psychology of solitary confinement to use in the legal context. Not only is there no consensus on whether solitary confinement is a cruel and unusual punishment, there is no consensus on the definition of the term ‘cruel’ in the use of that legal phrase. I argue that we ...

an unusual foreign body in human oesophagus – case report

African Journals Online (AJOL)

drclement

ABSTRACT. We report a case of a 65year old. Nigerian male with an unusual foreign body, a fishing hook in the oesophagus. This was confirmed with a plain radiograph of the chest done on a routine medical check-up, although patient was asymptomatic. The foreign body was removed via a rigid oesphagoscopy without ...

Unusual case of congenital/infantile fibrosarcoma in a new born ...

African Journals Online (AJOL)

We report an unusual case of CIFS occurring in new–born mimicking an hemangioma and causing hemorrhage in the neonatal period. The tumor is located in the left arm and axilla and associated with a hand malformation. A shoulder amputation is performed after chemotherapy failure. The infant is now two-years old with ...

Saffman-Taylor fingers with kinetic undercooling

KAUST Repository

Gardiner, Bennett P. J.

2015-02-23

© 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

Saffman-Taylor fingers with kinetic undercooling

KAUST Repository

Gardiner, Bennett P. J.; McCue, Scott W.; Dallaston, Michael C.; Moroney, Timothy J.

2015-01-01

© 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

Kinetics of Ni3S2 sulfide dissolution in solutions of sulfuric and hydrochloric acids

Science.gov (United States)

Palant, A. A.; Bryukvin, V. A.; Vinetskaya, T. N.; Makarenkova, T. A.

2008-02-01

The kinetics of Ni3S2 sulfide (heazlewoodite) dissolution in solutions of hydrochloric and sulfuric acids is studied. The process under study in the temperature range of 30 90°C is found to occur in a kinetic regime and is controlled by the corresponding chemical reactions of the Ni3S2 decomposition by solutions of inorganic acids ( E a = 67 92 kJ/mol, or 16 22 kcal/mol). The only exception is the Ni3S2-HCl system at elevated temperatures (60 90°C). In this case, the apparent activation energy decreases sharply to 8.8 kJ/mol (2.1 kcal/mol), which is explained by the catalytic effect of gaseous chlorine formed under these conditions. The studies performed are related to the physicochemical substantiation of the hydrometallurgical processing of the copper-nickel converter mattes produced in the industrial cycle of the Norilsk Mining Company.

Kinetic Study of Methyl Acetate Oxidation in a Pt/Al2O3 Fixed-Bed Reactor

Science.gov (United States)

Hoy, Michael; Li, K. Y.; Li, Jeffrey S.; Chen, S. M.; Yaws, C. L.; Chu, H. W.; Simon, W. E.

1994-01-01

To support technology development for future long-term missions, a metabolic simulator will be used in a closed chamber to test the functions of a Controlled Ecological Life Support System (CELSS). Methyl acetate (MA) was selected as the fuel because its metabolic respiratory quotient is near that of humans. A kinetic study of the catalytic oxidation of MA over Pt/Al203 was then conducted to support the design and operation of the simulator. Kinetic data were obtained as a conversion percentage of MA versus retention time. The reaction was studied at one atmosphere and temperatures from 220 to 340 deg. C. The inlet MA concentration was varied from 100 to 2000 ppm with retention times from 0.01 to 10 sec. A first-order rate law and a Langmuir-Hinshelwood rate equation were tested by nonlinear regression of the kinetic data to estimate rate constants in the rate law. Regression results of the L-H equation explain the kinetic data better than the results of the first-order rate law. A Taguchi experimental design was used to study the effects of temperature, retention time, and concentrations of MA, CO2, and O2 on the conversion of MA. Results indicate that temperature has greatest effect, followed by retention time, and finally MA concentration. It was further determined that the effects of CO2 and O2 concentrations, and the cross effects, are negligible.

Chemical kinetics of gas reactions

CERN Document Server

Kondrat'Ev, V N

2013-01-01

Chemical Kinetics of Gas Reactions explores the advances in gas kinetics and thermal, photochemical, electrical discharge, and radiation chemical reactions. This book is composed of 10 chapters, and begins with the presentation of general kinetic rules for simple and complex chemical reactions. The next chapters deal with the experimental methods for evaluating chemical reaction mechanisms and some theories of elementary chemical processes. These topics are followed by discussions on certain class of chemical reactions, including unimolecular, bimolecular, and termolecular reactions. The rema

Relativistic Chiral Kinetic Theory

International Nuclear Information System (INIS)

Stephanov, Mikhail

2016-01-01

This very brief review of the recent progress in chiral kinetic theory is based on the results of Refs. [J.-Y. Chen, D. T. Son, M. A. Stephanov, H.-U. Yee, Y. Yin, Lorentz Invariance in Chiral Kinetic Theory, Phys. Rev. Lett. 113 (18) (2014) 182302. doi: (10.1103/PhysRevLett.113.182302); J.-Y. Chen, D. T. Son, M. A. Stephanov, Collisions in Chiral Kinetic Theory, Phys. Rev. Lett. 115 (2) (2015) 021601. doi: (10.1103/PhysRevLett.115.021601); M. A. Stephanov, H.-U. Yee, The no-drag frame for anomalous chiral fluid, Phys. Rev. Lett. 116 (12) (2016) 122302. doi: (10.1103/PhysRevLett.116.122302)].

Relativistic Chiral Kinetic Theory

Energy Technology Data Exchange (ETDEWEB)

Stephanov, Mikhail

2016-12-15

This very brief review of the recent progress in chiral kinetic theory is based on the results of Refs. [J.-Y. Chen, D. T. Son, M. A. Stephanov, H.-U. Yee, Y. Yin, Lorentz Invariance in Chiral Kinetic Theory, Phys. Rev. Lett. 113 (18) (2014) 182302. doi: (10.1103/PhysRevLett.113.182302); J.-Y. Chen, D. T. Son, M. A. Stephanov, Collisions in Chiral Kinetic Theory, Phys. Rev. Lett. 115 (2) (2015) 021601. doi: (10.1103/PhysRevLett.115.021601); M. A. Stephanov, H.-U. Yee, The no-drag frame for anomalous chiral fluid, Phys. Rev. Lett. 116 (12) (2016) 122302. doi: (10.1103/PhysRevLett.116.122302)].

HTLV-I carrier with unusual brain MR imaging findings

Energy Technology Data Exchange (ETDEWEB)

Yata, Shinsaku; Ogawa, Toshihide; Sugihara, Shuji; Matsusue, Eiji; Fujii, Shinya; Kinoshita, Toshibumi [Tottori University, Department of Pathophysiological and Therapeutic Science, Yonago (Japan); Faculty of Medicine, Tottori University, Yonago (Japan)

2004-09-01

We describe unusual brain MR imaging findings in a patient who is an HTLV-I carrier without myelopathy. T2-weighted MR images showed hyperintense signal abnormalities in the pyramidal tract, superior and middle cerebellar peduncles, and decussation of the superior cerebellar peduncles, in addition to subcortical white matter involvement. Diffusion-weighted images also showed hyperintense signal abnormalities in the same regions by T2 shine-through effect. (orig.)

Jaw Dislocation as an Unusual Complication of Upper Endoscopy

Directory of Open Access Journals (Sweden)

Evan S. Dellon

2016-05-01

Full Text Available This case report presents an unusual complication of upper endoscopy, resulting in jaw dislocation. Temporomandibular joint dislocation is commonly reported in association with anesthesia and intubation, but it is not widely recognized as a complication of gastrointestinal endoscopy. This report also reviews the current literature regarding this complication and discusses the potential causes of dislocation, differential diagnoses for jaw pain following endoscopy, and recommendations for prevention.

Kinetic theory of gases and plasmas

International Nuclear Information System (INIS)

Schram, P.P.J.M.

1991-01-01

Kinetic theory provides the link between the non-equilibrium statistical mechanics of many-particle systems and macroscopic or phenomenological physics. This volume deals with the derivation of kinetic equations, their limitations and generalizations,and with the applications of kinetic theory to physical phenomena and the calculation of transport coefficients. This book is divided in 12 chapters which discuss a wide range of topics such as balanced equations, the Klimontovich, Vlasov-Maxwell, and Boltzmann equations, Chapman-Enskog theory, the kinetic theory of plasmas, B.G.K. models, linear response theory, Brownian motion and renormalized kinetic theory. Each chapter is concluded with exercises, which not only enable the readers to test their understanding of the theory, but also present additional examples which complement the text. 151 refs.; 35 figs.; 5 tabs

An Unusual Ocular Injury Following Facial Trauma: A Case Report ...

African Journals Online (AJOL)

Objective: To report a case of an unusual ocular injury following a road traffic accident. Materials and Methods: A case report of a sixty – year – old female patient seen by the authors. The literature on ocular injures following facial trauma is reviewed. Results: An eye globe initially confirmed missing from its socket on clinical ...

Crystallization Kinetics within a Generic Modelling Framework

DEFF Research Database (Denmark)

Meisler, Kresten Troelstrup; von Solms, Nicolas; Gernaey, Krist

2013-01-01

An existing generic modelling framework has been expanded with tools for kinetic model analysis. The analysis of kinetics is carried out within the framework where kinetic constitutive models are collected, analysed and utilized for the simulation of crystallization operations. A modelling...... procedure is proposed to gain the information of crystallization operation kinetic model analysis and utilize this for faster evaluation of crystallization operations....

In situ solid-state NMR and XRD studies of the ADOR process and the unusual structure of zeolite IPC-6

Science.gov (United States)

Morris, Samuel A.; Bignami, Giulia P. M.; Tian, Yuyang; Navarro, Marta; Firth, Daniel S.; Čejka, Jiří; Wheatley, Paul S.; Dawson, Daniel M.; Slawinski, Wojciech A.; Wragg, David S.; Morris, Russell E.; Ashbrook, Sharon E.

2017-10-01

The assembly-disassembly-organization-reassembly (ADOR) mechanism is a recent method for preparing inorganic framework materials and, in particular, zeolites. This flexible approach has enabled the synthesis of isoreticular families of zeolites with unprecedented continuous control over porosity, and the design and preparation of materials that would have been difficult—or even impossible—to obtain using traditional hydrothermal techniques. Applying the ADOR process to a parent zeolite with the UTL framework topology, for example, has led to six previously unknown zeolites (named IPC-n, where n = 2, 4, 6, 7, 9 and 10). To realize the full potential of the ADOR method, however, a further understanding of the complex mechanism at play is needed. Here, we probe the disassembly, organization and reassembly steps of the ADOR process through a combination of in situ solid-state NMR spectroscopy and powder X-ray diffraction experiments. We further use the insight gained to explain the formation of the unusual structure of zeolite IPC-6.

Unusual intraosseous transmigration of impacted tooth

Energy Technology Data Exchange (ETDEWEB)

Kumar, Santosh; Urala, Arun Srinivas; Kamath, Abhay Taranath; Jayaswal, Priyanka; Valiathan, Ashima [Manipal College of Dental Sciences, Manipal (India)

2012-03-15

Transmigration of an impacted tooth through the symphyseal suture is a rare and special developmental anomaly of unknown etiology that is unique to the mandibular canine. Maxillary canine transmigration is even rarer. Transmigrated canines are particularly significant due to the aesthetic and functional importance. A maxillary lateral incisor crossing the mid-palatal suture has never been reported in the literature. The aim of this report is to present the first case of simultaneous transmigration of a lateral incisor and canine in the maxilla. The paper also reports four unusual cases of unilateral canine transmigration in the maxilla and mandible and successful eruption of one of the transmigrated mandibular canines following orthodontic traction. Etiology of transmigration and its clinical considerations are also discussed.

Unusual presentation of twisted ovarian cyst

Directory of Open Access Journals (Sweden)

Vineet V Mishra

2016-01-01

Full Text Available Ovarian torsion (also termed as adnexal torsion refers to partial or complete rotation of the ovary and a portion of fallopian tube along its supplying vascular pedicle. It occurs commonly in reproductive age group; more on the right side (60% and often presents with acute lower abdominal pain lasting for few hours and up to 24 h, accounting for 2.7% of acute gynecological conditions. It is one of the devastating conditions, hampering blood supply of ovary which may lead to total necrosis of ovarian tissue and complications, if not diagnosed and managed in time. Hence, we present a case on a twisted ovarian cyst in postmenopausal woman with unusual symptomatology leading to delayed diagnosis and loss of an ovary.

Unusual intraosseous transmigration of impacted tooth

International Nuclear Information System (INIS)

Kumar, Santosh; Urala, Arun Srinivas; Kamath, Abhay Taranath; Jayaswal, Priyanka; Valiathan, Ashima

2012-01-01

Transmigration of an impacted tooth through the symphyseal suture is a rare and special developmental anomaly of unknown etiology that is unique to the mandibular canine. Maxillary canine transmigration is even rarer. Transmigrated canines are particularly significant due to the aesthetic and functional importance. A maxillary lateral incisor crossing the mid-palatal suture has never been reported in the literature. The aim of this report is to present the first case of simultaneous transmigration of a lateral incisor and canine in the maxilla. The paper also reports four unusual cases of unilateral canine transmigration in the maxilla and mandible and successful eruption of one of the transmigrated mandibular canines following orthodontic traction. Etiology of transmigration and its clinical considerations are also discussed.

Forecasting the Student-Professor Matches That Result in Unusually Effective Teaching

Science.gov (United States)

Gross, Jennifer; Lakey, Brian; Lucas, Jessica L.; LaCross, Ryan; Plotkowski, Andrea R.; Winegard, Bo

2015-01-01

Background: Two important influences on students' evaluations of teaching are relationship and professor effects. Relationship effects reflect unique matches between students and professors such that some professors are unusually effective for some students, but not for others. Professor effects reflect inter-rater agreement that some professors…

Lightning induced inappropriate ICD shock: an unusual case of electromagnetic interference.

Science.gov (United States)

Anderson, Daniel R; Gillberg, Jeffrey M; Torrey, Jeffrey W; Koneru, Jayanthi N

2012-06-01

An unusual case of electromagnetic interference is presented. As a result of a lightning shock to a Shower House, our patient received two shocks. An elucidation of the different mechanisms for the two shocks is presented. ©2010, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.