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Sample records for ectopic synaptic ribbons

  1. Synaptic ribbon. Conveyor belt or safety belt?

    Science.gov (United States)

    Parsons, T D; Sterling, P

    2003-02-06

    The synaptic ribbon in neurons that release transmitter via graded potentials has been considered as a conveyor belt that actively moves vesicles toward their release sites. But evidence has accumulated to the contrary, and it now seems plausible that the ribbon serves instead as a safety belt to tether vesicles stably in mutual contact and thus facilitate multivesicular release by compound exocytosis.

  2. Localization of Presynaptic Plasticity Mechanisms Enables Functional Independence of Synaptic and Ectopic Transmission in the Cerebellum

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    Katharine L. Dobson

    2015-01-01

    Full Text Available In the cerebellar molecular layer parallel fibre terminals release glutamate from both the active zone and from extrasynaptic “ectopic” sites. Ectopic release mediates transmission to the Bergmann glia that ensheathe the synapse, activating Ca2+-permeable AMPA receptors and glutamate transporters. Parallel fibre terminals exhibit several forms of presynaptic plasticity, including cAMP-dependent long-term potentiation and endocannabinoid-dependent long-term depression, but it is not known whether these presynaptic forms of long-term plasticity also influence ectopic transmission to Bergmann glia. Stimulation of parallel fibre inputs at 16 Hz evoked LTP of synaptic transmission, but LTD of ectopic transmission. Pharmacological activation of adenylyl cyclase by forskolin caused LTP at Purkinje neurons, but only transient potentiation at Bergmann glia, reinforcing the concept that ectopic sites lack the capacity to express sustained cAMP-dependent potentiation. Activation of mGluR1 caused depression of synaptic transmission via retrograde endocannabinoid signalling but had no significant effect at ectopic sites. In contrast, activation of NMDA receptors suppressed both synaptic and ectopic transmission. The results suggest that the signalling mechanisms for presynaptic LTP and retrograde depression by endocannabinoids are restricted to the active zone at parallel fibre synapses, allowing independent modulation of synaptic transmission to Purkinje neurons and ectopic transmission to Bergmann glia.

  3. Overexpression of guanylate cyclase activating protein 2 in rod photoreceptors in vivo leads to morphological changes at the synaptic ribbon.

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    Natalia López-del Hoyo

    Full Text Available Guanylate cyclase activating proteins are EF-hand containing proteins that confer calcium sensitivity to retinal guanylate cyclase at the outer segment discs of photoreceptor cells. By making the rate of cGMP synthesis dependent on the free intracellular calcium levels set by illumination, GCAPs play a fundamental role in the recovery of the light response and light adaptation. The main isoforms GCAP1 and GCAP2 also localize to the synaptic terminal, where their function is not known. Based on the reported interaction of GCAP2 with Ribeye, the major component of synaptic ribbons, it was proposed that GCAP2 could mediate the synaptic ribbon dynamic changes that happen in response to light. We here present a thorough ultrastructural analysis of rod synaptic terminals in loss-of-function (GCAP1/GCAP2 double knockout and gain-of-function (transgenic overexpression mouse models of GCAP2. Rod synaptic ribbons in GCAPs-/- mice did not differ from wildtype ribbons when mice were raised in constant darkness, indicating that GCAPs are not required for ribbon early assembly or maturation. Transgenic overexpression of GCAP2 in rods led to a shortening of synaptic ribbons, and to a higher than normal percentage of club-shaped and spherical ribbon morphologies. Restoration of GCAP2 expression in the GCAPs-/- background (GCAP2 expression in the absence of endogenous GCAP1 had the striking result of shortening ribbon length to a much higher degree than overexpression of GCAP2 in the wildtype background, as well as reducing the thickness of the outer plexiform layer without affecting the number of rod photoreceptor cells. These results indicate that preservation of the GCAP1 to GCAP2 relative levels is relevant for maintaining the integrity of the synaptic terminal. Our demonstration of GCAP2 immunolocalization at synaptic ribbons at the ultrastructural level would support a role of GCAPs at mediating the effect of light on morphological remodeling changes of

  4. Dysregulation of Ca(v)1.4 channels disrupts the maturation of photoreceptor synaptic ribbons in congenital stationary night blindness type 2.

    Science.gov (United States)

    Liu, Xiaoni; Kerov, Vasily; Haeseleer, Françoise; Majumder, Anurima; Artemyev, Nikolai; Baker, Sheila A; Lee, Amy

    2013-01-01

    Mutations in the gene encoding Cav 1.4, CACNA1F, are associated with visual disorders including X-linked incomplete congenital stationary night blindness type 2 (CSNB2). In mice lacking Cav 1.4 channels, there are defects in the development of "ribbon" synapses formed between photoreceptors (PRs) and second-order neurons. However, many CSNB2 mutations disrupt the function rather than expression of Cav 1.4 channels. Whether defects in PR synapse development due to altered Cav 1.4 function are common features contributing to the pathogenesis of CSNB2 is unknown. To resolve this issue, we profiled changes in the subcellular distribution of Cav 1.4 channels and synapse morphology during development in wild-type (WT) mice and mouse models of CSNB2. Using Cav 1.4-selective antibodies, we found that Cav 1.4 channels associate with ribbon precursors early in development and are concentrated at both rod and cone PR synapses in the mature retina. In mouse models of CSNB2 in which the voltage-dependence of Cav 1.4 activation is either enhanced (Cav 1.4I756T) or inhibited (CaBP4 KO), the initial stages of PR synaptic ribbon formation are largely unaffected. However, after postnatal day 13, many PR ribbons retain the immature morphology. This synaptic abnormality corresponds in severity to the defect in synaptic transmission in the adult mutant mice, suggesting that lack of sufficient mature synapses contributes to vision impairment in Cav 1.4I756T and CaBP4 KO mice. Our results demonstrate the importance of proper Cav 1.4 function for efficient PR synapse maturation, and that dysregulation of Cav 1.4 channels in CSNB2 may have synaptopathic consequences.

  5. Drosophila Syd-1, liprin-α, and protein phosphatase 2A B' subunit Wrd function in a linear pathway to prevent ectopic accumulation of synaptic materials in distal axons.

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    Li, Long; Tian, Xiaolin; Zhu, Mingwei; Bulgari, Dinara; Böhme, Mathias A; Goettfert, Fabian; Wichmann, Carolin; Sigrist, Stephan J; Levitan, Edwin S; Wu, Chunlai

    2014-06-18

    During synaptic development, presynaptic differentiation occurs as an intrinsic property of axons to form specialized areas of plasma membrane [active zones (AZs)] that regulate exocytosis and endocytosis of synaptic vesicles. Genetic and biochemical studies in vertebrate and invertebrate model systems have identified a number of proteins involved in AZ assembly. However, elucidating the molecular events of AZ assembly in a spatiotemporal manner remains a challenge. Syd-1 (synapse defective-1) and Liprin-α have been identified as two master organizers of AZ assembly. Genetic and imaging analyses in invertebrates show that Syd-1 works upstream of Liprin-α in synaptic assembly through undefined mechanisms. To understand molecular pathways downstream of Liprin-α, we performed a proteomic screen of Liprin-α-interacting proteins in Drosophila brains. We identify Drosophila protein phosphatase 2A (PP2A) regulatory subunit B' [Wrd (Well Rounded)] as a Liprin-α-interacting protein, and we demonstrate that it mediates the interaction of Liprin-α with PP2A holoenzyme and the Liprin-α-dependent synaptic localization of PP2A. Interestingly, loss of function in syd-1, liprin-α, or wrd shares a common defect in which a portion of synaptic vesicles, dense-core vesicles, and presynaptic cytomatrix proteins ectopically accumulate at the distal, but not proximal, region of motoneuron axons. Strong genetic data show that a linear syd-1/liprin-α/wrd pathway in the motoneuron antagonizes glycogen synthase kinase-3β kinase activity to prevent the ectopic accumulation of synaptic materials. Furthermore, we provide data suggesting that the syd-1/liprin-α/wrd pathway stabilizes AZ specification at the nerve terminal and that such a novel function is independent of the roles of syd-1/liprin-α in regulating the morphology of the T-bar structural protein BRP (Bruchpilot). Copyright © 2014 the authors 0270-6474/14/348474-14$15.00/0.

  6. Drosophila Syd-1, Liprin-α, and Protein Phosphatase 2A B′ Subunit Wrd Function in a Linear Pathway to Prevent Ectopic Accumulation of Synaptic Materials in Distal Axons

    Science.gov (United States)

    Li, Long; Tian, Xiaolin; Zhu, Mingwei; Bulgari, Dinara; Böhme, Mathias A.; Goettfert, Fabian; Wichmann, Carolin; Sigrist, Stephan J.; Levitan, Edwin S.

    2014-01-01

    During synaptic development, presynaptic differentiation occurs as an intrinsic property of axons to form specialized areas of plasma membrane [active zones (AZs)] that regulate exocytosis and endocytosis of synaptic vesicles. Genetic and biochemical studies in vertebrate and invertebrate model systems have identified a number of proteins involved in AZ assembly. However, elucidating the molecular events of AZ assembly in a spatiotemporal manner remains a challenge. Syd-1 (synapse defective-1) and Liprin-α have been identified as two master organizers of AZ assembly. Genetic and imaging analyses in invertebrates show that Syd-1 works upstream of Liprin-α in synaptic assembly through undefined mechanisms. To understand molecular pathways downstream of Liprin-α, we performed a proteomic screen of Liprin-α-interacting proteins in Drosophila brains. We identify Drosophila protein phosphatase 2A (PP2A) regulatory subunit B′ [Wrd (Well Rounded)] as a Liprin-α-interacting protein, and we demonstrate that it mediates the interaction of Liprin-α with PP2A holoenzyme and the Liprin-α-dependent synaptic localization of PP2A. Interestingly, loss of function in syd-1, liprin-α, or wrd shares a common defect in which a portion of synaptic vesicles, dense-core vesicles, and presynaptic cytomatrix proteins ectopically accumulate at the distal, but not proximal, region of motoneuron axons. Strong genetic data show that a linear syd-1/liprin-α/wrd pathway in the motoneuron antagonizes glycogen synthase kinase-3β kinase activity to prevent the ectopic accumulation of synaptic materials. Furthermore, we provide data suggesting that the syd-1/liprin-α/wrd pathway stabilizes AZ specification at the nerve terminal and that such a novel function is independent of the roles of syd-1/liprin-α in regulating the morphology of the T-bar structural protein BRP (Bruchpilot). PMID:24948803

  7. Ribbon curling

    Science.gov (United States)

    Juel, Anne; Prior, Chris; Moussou, Julien; Chakrabarti, Buddhapriya; Jensen, Oliver

    The procedure of curling a ribbon by running it over a sharp blade is commonly used when wrapping presents. Despite its ubiquity, a quantitative explanation of this everyday phenomenon is still lacking. We address this using experiment and theory, examining the dependence of ribbon curvature on blade curvature, the longitudinal load imposed on the ribbon and the speed of pulling. Experiments in which a ribbon is drawn steadily over a blade under a fixed load show that the ribbon curvature is generated over a restricted range of loads, the curvature/load relationship can be non-monotonic, and faster pulling (under a constant imposed load) results in less tightly curled ribbons. We develop a theoretical model that captures these features, building on the concept that the ribbon under the imposed deformation undergoes differential plastic stretching across its thickness, resulting in a permanently curved shape. The model identifies factors that optimize curling and clarifies the physical mechanisms underlying the ribbon's nonlinear response to an apparently simple deformation.

  8. Ectopic Pregnancy

    Science.gov (United States)

    ... woman is pregnant. If you have an ectopic pregnancy, the fertilized egg grows in the wrong place, ... tubes. The result is usually a miscarriage. Ectopic pregnancy can be a medical emergency if it ruptures. ...

  9. Ectopic Pregnancy

    Science.gov (United States)

    ... caused by blood loss) lower back pain What Causes an Ectopic Pregnancy? An ectopic pregnancy usually happens because a fertilized ... protect against sexually transmitted infections (STDs) that can cause PID. If ... about the pregnancy being ectopic, talk to your doctor — it's important ...

  10. Ca(2+) influx and neurotransmitter release at ribbon synapses.

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    Cho, Soyoun; von Gersdorff, Henrique

    2012-01-01

    Ca(2+) influx through voltage-gated Ca(2+) channels triggers the release of neurotransmitters at presynaptic terminals. Some sensory receptor cells in the peripheral auditory and visual systems have specialized synapses that express an electron-dense organelle called a synaptic ribbon. Like conventional synapses, ribbon synapses exhibit SNARE-mediated exocytosis, clathrin-mediated endocytosis, and short-term plasticity. However, unlike non-ribbon synapses, voltage-gated L-type Ca(2+) channel opening at ribbon synapses triggers a form of multiquantal release that can be highly synchronous. Furthermore, ribbon synapses appear to be specialized for fast and high throughput exocytosis controlled by graded membrane potential changes. Here we will discuss some of the basic aspects of synaptic transmission at different types of ribbon synapses, and we will emphasize recent evidence that auditory and retinal ribbon synapses have marked differences. This will lead us to suggest that ribbon synapses are specialized for particular operating ranges and frequencies of stimulation. We propose that different types of ribbon synapses transfer diverse rates of sensory information by expressing a particular repertoire of critical components, and by placing them at precise and strategic locations, so that a continuous supply of primed vesicles and Ca(2+) influx leads to fast, accurate, and ongoing exocytosis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Elongation of Flare Ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jiong; Longcope, Dana W. [Department of Physics, Montana State University, Bozeman MT (United States); Cassak, Paul A. [Department of Physics and Astronomy, West Virginia University, Morgantown WV (United States); Priest, Eric R. [School of Mathematics and Statistics, University of St. Andrews, Fife KY16 9SS, Scotland (United Kingdom)

    2017-03-20

    We present an analysis of the apparent elongation motion of flare ribbons along the polarity inversion line (PIL), as well as the shear of flare loops in several two-ribbon flares. Flare ribbons and loops spread along the PIL at a speed ranging from a few to a hundred km s{sup −1}. The shear measured from conjugate footpoints is consistent with the measurement from flare loops, and both show the decrease of shear toward a potential field as a flare evolves and ribbons and loops spread along the PIL. Flares exhibiting fast bidirectional elongation appear to have a strong shear, which may indicate a large magnetic guide field relative to the reconnection field in the coronal current sheet. We discuss how the analysis of ribbon motion could help infer properties in the corona where reconnection takes place.

  12. Blue Ribbon Panel Report

    Science.gov (United States)

    An NCI Cancer Currents blog by the NCI acting director thanking the cancer community for contributing to the Cancer Moonshot Blue Ribbon Panel report, which was presented to the National Cancer Advisory Board on September 7.

  13. After the Ribbon Cutting

    DEFF Research Database (Denmark)

    Hodge, Graeme A.; Boulot, Emille; Duffield, Colin

    2017-01-01

    Much attention has gone towards ‘up-front’ processes when delivering infrastructure public–private partnerships (PPPs), but less on how to best govern after the ribbon is cut and the infrastructure built. This paper identifies the primary contractual and institutional governance challenges arising...

  14. Primary Intraorbital Ectopic Meningioma

    Science.gov (United States)

    Yokoyama, Tetsuo; Nishizawa, Shigeru; Sugiyama, Kenji; Yokota, Noki; Ohta, Seiji; Uemura, Kenichi; Hinokuma, Kaoru; Inenaga, Chikanori

    1999-01-01

    We report a case of intraorbital meningioma. Operative findings and histopathological examination revealed the tumoc to be meningothelial meningloma and to be located entirely outside the optic dura. This case demonstrates the occurrence of primary intraorbital ectopic meningioma, and the tumor was removed through a modified Dolenc approach. The primary intraorbital ectopic meningioma is discussed and the surgical approach to the orbital apex region is reviewed. ImagesFigure 1Figure 2Figure 4Figure 5 PMID:17171081

  15. Baffles Promote Wider, Thinner Silicon Ribbons

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    Seidensticker, Raymond G.; Mchugh, James P.; Hundal, Rolv; Sprecace, Richard P.

    1989-01-01

    Set of baffles just below exit duct of silicon-ribbon-growing furnace reduces thermal stresses in ribbons so wider ribbons grown. Productivity of furnace increased. Diverts plume of hot gas from ribbon and allows cooler gas from top of furnace to flow around. Also shields ribbon from thermal radiation from hot growth assembly. Ribbon cooled to lower temperature before reaching cooler exit duct, avoiding abrupt drop in temperature as entering duct.

  16. Suspected ectopic pregnancy.

    Science.gov (United States)

    Seeber, Beata E; Barnhart, Kurt T

    2006-02-01

    Women who present with pain and bleeding in the first trimester are at risk for ectopic pregnancy, a life-threatening condition. Conditions that predispose a woman to ectopic pregnancy are damaged fallopian tubes from prior tubal surgery or previous pelvic infection, smoking, and conception using assisted reproduction. Many women without risk factors can develop an ectopic pregnancy. A diagnostic algorithm that includes the use of transvaginal ultrasonography, human chorionic gonadotropin (hCG) concentrations, and, sometimes, uterine curettage can definitively diagnose women at risk in a timely manner. The absence of an intrauterine pregnancy above an established cut point of hCG is consistent with an abnormal pregnancy but does not distinguish a miscarriage from an ectopic pregnancy. When the initial hCG value is low, serial hCG values can be used to determine whether a gestation is potentially viable or spontaneously resolving. The minimal rise in hCG for a viable pregnancy is 53% in 2 days. The minimal decline of a spontaneous abortion is 21-35% in 2 days, depending on the initial level. A rise or fall in serial hCG values that is slower than this is suggestive of an ectopic pregnancy. Women diagnosed with an unruptured ectopic pregnancy are potential candidates for medical management with methotrexate. Intramuscular injection with methotrexate can be used to safely treat an ectopic pregnancy with success rates, tubal patency rates, and future fertility that are similar to those obtained with conservative surgery. Success rates using methotrexate are inversely rated to baseline hCG values and are higher using "multidose" compared with "single-dose" regimens. Surgical treatment may be conservative or definitive and should be attempted in most cases via laparoscopy.

  17. Ruptured Ectopic Pregnancy

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    Valentina Park

    2016-09-01

    Full Text Available History of present illness: A 21-year-old female presented with sudden onset suprapubic abdominal pain associated with dysuria. The patient also experienced near syncope during bowel movements three times three days ago without falling or losing consciousness. She denied fever, nausea, and vomiting. She stated that she was five weeks pregnant by last menstrual period. She had an ultrasound a few weeks before that showed no intrauterine pregnancy, but she had not followed up for additional testing. Significant findings: The patient’s serum beta-hCG was 5,637 mIU/mL. The transvaginal ultrasound showed an empty uterus with free fluid posteriorly in the pelvis and Pouch of Douglas (00:00. A 4.5 cm heterogeneous mass was visible in the left adnexa concerning for an ectopic pregnancy (00:10. Discussion: Ectopic pregnancies are a leading cause of maternal morbidity and mortality, as well as decreased fertility.1,2 Differentiating between an ectopic pregnancy and a normal early pregnancy may be difficult, since ultrasound and quantitative beta-hCG may show inconclusive results.3,4 Patients who have used fertility treatment may further complicate the picture because they are at risk for heterotypic pregnancies.5 Ectopic pregnancies most commonly implant in the fallopian tube, but may alternatively implant in the ovary, cervix, abdomen, or uterine cornua.4 Ultrasonography may show an empty uterus, adnexal mass, pelvic free fluid, or an extra-uterine gestational sac, yolk sac, and/or embryo.6 Treatment options for ectopic pregnancy include surgery or methotrexate.2,4 Some patients may be candidates for close outpatient surveillance if the diagnosis is unclear or in very limited cases for early, non-ruptured ectopic pregnancies.2,4

  18. Ectopic ovarian pregnancy

    International Nuclear Information System (INIS)

    Sachdev, P.S.; Jatoi, N.; Memon, R.A.; Sachdev, C.S.

    2003-01-01

    A case of ectopic ovarian pregnancy is presented occurring in a 24 years old woman after natural conception. The clinical diagnosis was ruptured tubal pregnancy. Gross findings were suggestive of ruptured corpus luteum cyst on exploration. The histopathological examination of specimen brought forward the diagnosis of ovarian pregnancy. (author)

  19. Mammalian Cochlear Hair Cell Regeneration and Ribbon Synapse Reformation

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    Xiaoling Lu

    2016-01-01

    Full Text Available Hair cells (HCs are the sensory preceptor cells in the inner ear, which play an important role in hearing and balance. The HCs of organ of Corti are susceptible to noise, ototoxic drugs, and infections, thus resulting in permanent hearing loss. Recent approaches of HCs regeneration provide new directions for finding the treatment of sensor neural deafness. To have normal hearing function, the regenerated HCs must be reinnervated by nerve fibers and reform ribbon synapse with the dendrite of spiral ganglion neuron through nerve regeneration. In this review, we discuss the research progress in HC regeneration, the synaptic plasticity, and the reinnervation of new regenerated HCs in mammalian inner ear.

  20. Synaptic Cell Adhesion

    OpenAIRE

    Missler, Markus; Südhof, Thomas C.; Biederer, Thomas

    2012-01-01

    Chemical synapses are asymmetric intercellular junctions that mediate synaptic transmission. Synaptic junctions are organized by trans-synaptic cell adhesion molecules bridging the synaptic cleft. Synaptic cell adhesion molecules not only connect pre- and postsynaptic compartments, but also mediate trans-synaptic recognition and signaling processes that are essential for the establishment, specification, and plasticity of synapses. A growing number of synaptic cell adhesion molecules that inc...

  1. Ectopic corticotroph syndrome

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    Penezić Zorana

    2004-01-01

    Full Text Available INTRODUCTION Endogenous Cushing's syndrome is a clinical state resulting from prolonged, inappropriate exposure to excessive endogenous secretion of Cortisol and hence excess circulating free cortisol, characterized by loss of the normal feedback mechanisms of the hypothalamo-pituitary-adrenal axis and the normal circadian rhythm of cortisol secretion [2]. The etiology of Cushing's syndrome may be excessive ACTH secretion from the pituitary gland, ectopic ACTH secretion by nonpituitary tumor, or excessive autonomous secretion of cortisol from a hyperfunctioning adrenal adenoma or carcinoma. Other than this broad ACTH-dependent and ACTH-independent categories, the syndrome may be caused by ectopic CRH secretion, PPNAD, MAH, ectopic action of GIP or catecholamines, and other adrenel-dependent processes associated with adrenocortical hyperfunction. CASE REPORT A 31 year-old men with b-month history of hyperpigmentation, weight gain and proximal myopathy was refereed to Institute of Endocrinology for evaluation of hypercortisolism. At admission, patient had classic cushingoid habit with plethoric face, dermal and muscle atrophy, abdominal strie rubrae and centripetal obesity. The standard laboratory data showed hyperglycaemia and hypokaliemia with high potassium excretion level. The circadian rhythm of cortisol secretion was blunted, with moderately elevated ACTH level, and without cortisol suppression after low-dose and high-dose dexamethason suppression test. Urinary 5HIAA was elevated. Abdominal and sellar region magnetic resonance imaging was negative. CRH stimulation resulted in ACTH increase of 87% of basal, but without significant increase of cortisol level, only 7%. Thoracal CT scan revealed 14 mm mass in right apical pulmonary segment. A wedge resection of anterior segment of right upper lobe was performed. Microscopic evaluation showed tumor tissue consisting of solid areas of uniform, oval cells with eosinophilic cytoplasm and centrally

  2. EDITORIAL: Synaptic electronics Synaptic electronics

    Science.gov (United States)

    Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique

    2013-09-01

    Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic electronics', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the

  3. Secondary abdominal appendicular ectopic pregnancy.

    Science.gov (United States)

    Nama, Vivek; Gyampoh, Bright; Karoshi, Mahantesh; McRae, Reynold; Opemuyi, Isaac

    2007-01-01

    Although the case fatality rate for ectopic pregnancies has decreased to 0.08% in industrialized countries, it still represents 3.8% of maternal mortality in the United States alone. In developing countries, the case fatality rate varies from 3% to 27%. Laparoscopic management of tubal pregnancies is now the standard form of treatment where this technology is available. Abdominal pregnancies are rare, and secondary implantation of tubal ectopic pregnancies is the most common cause of abdominal gestations. We present an interesting case of secondary implantation of a tubal ectopic pregnancy to highlight the appendix as a possible secondary implantation site after a tubal ectopic pregnancy.

  4. Amorphous metal matrix composite ribbons

    International Nuclear Information System (INIS)

    Barczy, P.; Szigeti, F.

    1998-01-01

    Composite ribbons with amorphous matrix and ceramic (SiC, WC, MoB) particles were produced by modified planar melt flow casting methods. Weldability, abrasive wear and wood sanding examinations were carried out in order to find optimal material and technology for elevated wear resistance and sanding durability. The correlation between structure and composite properties is discussed. (author)

  5. Primary ectopic frontotemporal extradural craniopharyngioma

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    Reza Pourkhalili

    2016-01-01

    Full Text Available We present a case of primary ectopic frontotemporal extradural craniopharyngioma. Primary ectopic craniopharyngiomas are very rare and have been reported involving the fourth ventricle, infrasellar region, lateral ventricle, temporal area, cerebellopontine angle, clivus, corpus callosum, and prepontine cistern. There was just 1 case of craniopharyngioma previously presented in the literature, with nearly same location as the presenting case.

  6. Isolated petrous apex ectopic craniopharyngioma

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    Julius July

    2015-12-01

    Full Text Available Primary ectopic craniopharyngioma is a rare entity. Isolated petrous apex bone location has not been reported previously. This study reports a case of 26-year-old male with right abducent nerve palsy. CT and MRI imaging reveal right petrous apex cystic lesion. No sellar or suprasellar region involvement was found. Endoscopic endonasal transphenoid approach has been successfully performed. Histopathology examination confirms the diagnosis of adamantinomatous craniopharyngioma. So far, it’s probably the first case report of primary ectopic craniopharyngioma isolated in the petrous apex. This case report supports the premise that primary ectopic craniopharyngioma is a multifactorial process that starts with an error from migrated embryological cells.

  7. Chirality effect in disordered graphene ribbon junctions

    International Nuclear Information System (INIS)

    Long Wen

    2012-01-01

    We investigate the influence of edge chirality on the electronic transport in clean or disordered graphene ribbon junctions. By using the tight-binding model and the Landauer-Büttiker formalism, the junction conductance is obtained. In the clean sample, the zero-magnetic-field junction conductance is strongly chirality-dependent in both unipolar and bipolar ribbons, whereas the high-magnetic-field conductance is either chirality-independent in the unipolar or chirality-dependent in the bipolar ribbon. Furthermore, we study the disordered sample in the presence of magnetic field and find that the junction conductance is always chirality-insensitive for both unipolar and bipolar ribbons with adequate disorders. In addition, the disorder-induced conductance plateaus can exist in all chiral bipolar ribbons provided the disorder strength is moderate. These results suggest that we can neglect the effect of edge chirality in fabricating electronic devices based on the magnetotransport in a disordered graphene ribbon. (paper)

  8. Ectopic lingual thyroid

    International Nuclear Information System (INIS)

    Amani, Mohammed El Amine; Benabadji, Nadjia; Benzian, Zakaria; Amani, Souad

    2012-01-01

    Thyroid ectopy is characterized by the presence of thyroid tissue outside its normal position resulting from a defect of the thyroid diverticulum migration from the base of the tongue until its final pre-tracheal position. One case is presented in a 12-year-old girl patient who consults for a failure to thrive estimated at less than three standard deviations (SD). Bone age was estimated at 8 years late compared to chronological age. The hormonal assessment showed hypothyroidism with negative thyroid antibodies. Cervical ultrasound was revealed thyroid parenchyma pre-dominantly left in place while sweeping the area under chin showed a nodular formation of the base of the tongue. Thyroid scan with technetium 99 m showed a selective uptake of radiotracer in sublingual position. Cervical computed tomography revealed a posterior median sublingual mass spontaneously hyperdense and enhancing sharply after injection of contrast. Treatment with thyroxine allowed obtaining euthyroidism. This case asks us to be careful before aetiological diagnosis of hypothyroidism in children, because although this is rare, the presence of a thyroid parenchyma up to the cervical ultrasound does not eliminate the presence of ectopic tissue

  9. Synaptic Vesicle Endocytosis in Different Model Systems

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    Quan Gan

    2018-06-01

    Full Text Available Neurotransmission in complex animals depends on a choir of functionally distinct synapses releasing neurotransmitters in a highly coordinated manner. During synaptic signaling, vesicles fuse with the plasma membrane to release their contents. The rate of vesicle fusion is high and can exceed the rate at which synaptic vesicles can be re-supplied by distant sources. Thus, local compensatory endocytosis is needed to replenish the synaptic vesicle pools. Over the last four decades, various experimental methods and model systems have been used to study the cellular and molecular mechanisms underlying synaptic vesicle cycle. Clathrin-mediated endocytosis is thought to be the predominant mechanism for synaptic vesicle recycling. However, recent studies suggest significant contribution from other modes of endocytosis, including fast compensatory endocytosis, activity-dependent bulk endocytosis, ultrafast endocytosis, as well as kiss-and-run. Currently, it is not clear whether a universal model of vesicle recycling exist for all types of synapses. It is possible that each synapse type employs a particular mode of endocytosis. Alternatively, multiple modes of endocytosis operate at the same synapse, and the synapse toggles between different modes depending on its activity level. Here we compile review and research articles based on well-characterized model systems: frog neuromuscular junctions, C. elegans neuromuscular junctions, Drosophila neuromuscular junctions, lamprey reticulospinal giant axons, goldfish retinal ribbon synapses, the calyx of Held, and rodent hippocampal synapses. We will compare these systems in terms of their known modes and kinetics of synaptic vesicle endocytosis, as well as the underlying molecular machineries. We will also provide the future development of this field.

  10. Ectopic ureterocele and ectopic ureter in pediatric patients

    International Nuclear Information System (INIS)

    Lloret, M. T.; Ricart, V.; Muro, M. D.; Perez, D.; Martinez, I.; Brugger, S.; Romero, M. J.; Cortina, H.

    2000-01-01

    To describe the radiological findings associated with ectopic ureterocele and ectopic ureter in pediatric patients. To assess the role of ultrasound (US), serial micturating cystourethrography (SM-CU) and intravenous urography (IVU) in the diagnosis of these two entities. The authors performed a retrospective study of 132 patients, 73 with ectopic ureterocele and 59 with ectopic ureter. The imaging studies used were US, SMCU, IVU and methods to determine renal function (diuretic renography and renal scintigraphy). The findings were confirmed during surgery in every case. The most common radiological findings in ectopic ureterocele were renal duplication (86,3%). vesicoureteral reflux (VUR) to the lower half of the kidney (46.6%), dilatation of the lower pole of the kidney (38.4%) and contralateral duplication (30.1%). In boys, the ectopic ureter entered via bladder neck and posterior urethra (73.7%) or into seminal vesicles (15.8%); in girls, it went to vagina (32.5%), bladder neck (30%) or urethra (22.5%). Renal duplication was associated in 64.4%, with VUR to the ectopic ureter in 21% while there was a single renal system in 35.6%, with VUR to the ectopic ureter in 57.1% and contralateral renal agenesis in 19%. Eighteen patients (13.6%) presented a single, dy plastic, nonfunctioning renal system (6 cases of ureterocele and 12 of ectopic ureter). Knowledge of the embryological development of ureteral duplication is essential for the understanding of these two entities and helps to differentiate between them, thus facilitating a sometimes complicated diagnosis. Ectopic ureters and ureteroceles accompanied by a single, dysplastic renal system are associated with a greater incidence of congenital anomalies and a higher rate of complications than the duplicate systems. A prenatal US examination enables early diagnosis. The anatomical information provided by US is, on occasion, more valuable than that resulting from IVU or SMCU, However, IVU is indispensable in girls

  11. ECTOPIC ureters misdiagnosed as ureterocele

    International Nuclear Information System (INIS)

    Bader, I.; Akhter, N.; Anwar-ul-Haq; Chaudhary, A.; Khan, N.Z.

    2004-01-01

    Ectopic ureters may be difficult to diagnose unless there is high index of suspicion. Examination for continuous dribbling may be difficult in infants who are still using diapers. We are reporting a case of ectopic ureter which was erroneously diagnosed as ureterocele on a cystourethrogram. Further investigations for accurate diagnosis and emerging abnormalities during the course of management are presented in this case report. Review of literature to high- light the various forms of investigations and management are also presented. (author)

  12. Geothermal Technologies Program Blue Ribbon Panel Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-06-17

    The Geothermal Technologies Program assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a guided discussion on the future of geothermal energy in the United States and the role of the DOE Program. The Geothermal Blue Ribbon Panel Report captures the discussions and recommendations of the experts. An addendum is available here: http://www.eere.energy.gov/geothermal/pdfs/gtp_blue_ribbon_panel_report_addendum10-2011.pdf

  13. Dislocation dynamics of web type silicon ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, Jr, O W; Tsai, C T; DeAngelis, R J

    1987-03-01

    Silicon ribbon grown by the dendritic web process passes through a rapidly changing thermal profile in the growth direction. This rapidly changing profile induces stresses which produce changes in the dislocation density in the ribbon. A viscoplastic material response function (Haasen-Sumino model) is used herein to calculate the stresses and the dislocation density at each point in the silicon ribbon. The residual stresses are also calculated.

  14. Numerical Simulation Of Silicon-Ribbon Growth

    Science.gov (United States)

    Woda, Ben K.; Kuo, Chin-Po; Utku, Senol; Ray, Sujit Kumar

    1987-01-01

    Mathematical model includes nonlinear effects. In development simulates growth of silicon ribbon from melt. Takes account of entire temperature and stress history of ribbon. Numerical simulations performed with new model helps in search for temperature distribution, pulling speed, and other conditions favoring growth of wide, flat, relatively defect-free silicon ribbons for solar photovoltaic cells at economically attractive, high production rates. Also applicable to materials other than silicon.

  15. Gas-Jet Meniscus Control in Ribbon Growth

    Science.gov (United States)

    Zoutendyk, J. A.; Vonroos, O.

    1983-01-01

    Gas jet used to control shape of meniscus and thus to regulate ribbon thickness in vertical silicon-ribbon growth. Gas jet also cools ribbon, increasing maximum possible pull speed for silicon, contact angle of 11 degrees plus or minus 1 degree required for constant thickness ribbon growth. Cooling effect of gas jet increases maximum possible pull speed.

  16. [Ectopic breast fibroadenoma. Case report].

    Science.gov (United States)

    Senatore, G; Zanotti, S; Cambrini, P; Montroni, I; Pellegrini, A; Montanari, E; Santini, D; Taffurelli, M

    2010-03-01

    Among the rare anomalies of the breast development, polythelia is the most common, between 1% and 5% of women and men present supernumerary nipples. Polymastia, usually presenting as ectopic breast tissue without areola-nipple complex, is seen mostly along the milk line, extending from the axilla to the pubic region. Ectopic breast tissue is functionally analogous to mammary gland and it is subjected to the same alterations and diseases, whether benign or malignant, that affect normal breast tissue. We report the case of a 21 years-old female evaluated by the medical staff after founding a solid nodular mass by suspect axillary lymphadenopathy. Differential diagnosis with lymphoma is the major problem in these cases. The mass was removed and the intraoperative histological examination showed fibroadenoma in axillary supernumerary breast. Presence of ectopic breast tissue is a rare condition; development of benign mass or malignant degeneration is possible, but it is very unusual. In case of polymastia diagnosis is simple; in case of isolated nodule, without local inflammation or infection, there are greater difficulties. Ultrasonography is diagnostic in case of breast fibroadenoma, but it might be inadequate in ectopic localizations owing to the shortage of mammary tissue around the mass. Preoperative diagnosis is important to plan an adequate surgical treatment; lumpectomy is indicated in case of benign tissue; in case of malignancy, therapy is based on the standard treatment used for breast cancer (surgery, chemotherapy and radiation therapy).

  17. The ectopic posterior pituitary gland

    African Journals Online (AJOL)

    2013-11-04

    Nov 4, 2013 ... crinology with short stature, delayed bone age and biochemical features suggestive of hypo pituitarism. Magnetic resonance imaging of the brain demonstrated a flattened anterior pituitary gland within the sella, associated with absence of the infundibular stalk and an ectopic posterior pituitary gland (Fig.

  18. Interventions for tubal ectopic pregnancy

    NARCIS (Netherlands)

    Hajenius, P. J.; Mol, B. W.; Bossuyt, P. M.; Ankum, W. M.; van der Veen, F.

    2000-01-01

    BACKGROUND: The diagnosis of ectopic pregnancy can now often be made by non-invasive methods due to sensitive pregnancy tests (in urine and serum) and high resolution transvaginal sonography, which have been integrated in diagnostic algorithms. These algorithms, in combination with the increased

  19. Interventions for tubal ectopic pregnancy

    NARCIS (Netherlands)

    Hajenius, P. J.; Mol, F.; Mol, B. W. J.; Bossuyt, P. M. M.; Ankum, W. M.; van der Veen, F.

    2007-01-01

    BACKGROUND: Treatment options for tubal ectopic pregnancy are; (1) surgery, e.g. salpingectomy or salpingo(s)tomy, either performed laparoscopically or by open surgery; (2) medical treatment, with a variety of drugs, that can be administered systemically and/or locally by various routes and (3)

  20. The Flexibility of Ectopic Lipids

    Directory of Open Access Journals (Sweden)

    Hannah Loher

    2016-09-01

    Full Text Available In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL, skeletal (intramyocellular lipids; IMCL or cardiac muscle cells (intracardiomyocellular lipids; ICCL. Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. 1H-magnetic resonance spectroscopy (1H-MRS is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass, insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations.

  1. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  2. ON THE GEOMETRY OF THE IBEX RIBBON

    Energy Technology Data Exchange (ETDEWEB)

    Sylla, Adama; Fichtner, Horst [Institut für Theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2015-10-01

    The Energetic Neutral Atom (ENA) full-sky maps obtained with the Interstellar Boundary Explorer (IBEX) show an unexpected bright narrow band of increased intensity. This so-called ENA ribbon results from charge exchange of interstellar neutral atoms with protons in the outer heliosphere or beyond. Among other hypotheses it has been argued that this ribbon may be related to a neutral density enhancement, or H-wave, in the local interstellar medium. Here we quantitatively demonstrate, on the basis of an analytical model of the principal large-scale heliospheric structure, that this scenario for the ribbon formation leads to results that are fully consistent with the observed location of the ribbon in the full-sky maps at all energies detected with high-energy sensor IBEX-Hi.

  3. Mechanisms of Ectopic Gene Conversion

    Directory of Open Access Journals (Sweden)

    P.J. Hastings

    2010-11-01

    Full Text Available Gene conversion (conversion, the unidirectional transfer of DNA sequence information, occurs as a byproduct of recombinational repair of broken or damaged DNA molecules. Whereas excision repair processes replace damaged DNA by copying the complementary sequence from the undamaged strand of duplex DNA, recombinational mechanisms copy similar sequence, usually in another molecule, to replace the damaged sequence. In mitotic cells the other molecule is usually a sister chromatid, and the repair does not lead to genetic change. Less often a homologous chromosome or homologous sequence in an ectopic position is used. Conversion results from repair in two ways. First, if there was a double-strand gap at the site of a break, homologous sequence will be used as the template for synthesis to fill the gap, thus transferring sequence information in both strands. Second, recombinational repair uses complementary base pairing, and the heteroduplex molecule so formed is a source of conversion, both as heteroduplex and when donor (undamaged template information is retained after correction of mismatched bases in heteroduplex. There are mechanisms that favour the use of sister molecules that must fail before ectopic homology can be used. Meiotic recombination events lead to the formation of crossovers required in meiosis for orderly segregation of pairs of homologous chromosomes. These events result from recombinational repair of programmed double-strand breaks, but in contrast with mitotic recombination, meiotic recombinational events occur predominantly between homologous chromosomes, so that transfer of sequence differences by conversion is very frequent. Transient recombination events that do not form crossovers form both between homologous chromosomes and between regions of ectopic homology, and leave their mark in the occurrence of frequent non-crossover conversion, including ectopic conversion.

  4. Ectopic intra-abdominal fascioliasis

    OpenAIRE

    ÖNGÖREN, Ali Ulvi

    2009-01-01

    Human fascioliasis, caused by Fasciola hepatica, is emerging as an important chronic zoonotic disease in many areas of the world, including Turkey. It primarily involves the liver and may also cause severe damage in the tissue. Herein we report on a patient with ectopic intra-abdominal fascioliasis that presented to our clinic with abdominal pain and distention. Physical and radiological examination as well as an exploratory laparotomy revealed a 10 × 10-cm mass in the splenic flexura of the ...

  5. Synaptic Plasticity and Nociception

    Institute of Scientific and Technical Information of China (English)

    ChenJianguo

    2004-01-01

    Synaptic plasticity is one of the fields that progresses rapidly and has a lot of success in neuroscience. The two major types of synaptie plasticity: long-term potentiation ( LTP and long-term depression (LTD are thought to be the cellular mochanisms of learning and memory. Recently, accumulating evidence suggests that, besides serving as a cellular model for learning and memory, the synaptic plasticity involves in other physiological or pathophysiological processes, such as the perception of pain and the regulation of cardiovascular system. This minireview will focus on the relationship between synaptic plasticity and nociception.

  6. Banach Synaptic Algebras

    Science.gov (United States)

    Foulis, David J.; Pulmannov, Sylvia

    2018-04-01

    Using a representation theorem of Erik Alfsen, Frederic Schultz, and Erling Størmer for special JB-algebras, we prove that a synaptic algebra is norm complete (i.e., Banach) if and only if it is isomorphic to the self-adjoint part of a Rickart C∗-algebra. Also, we give conditions on a Banach synaptic algebra that are equivalent to the condition that it is isomorphic to the self-adjoint part of an AW∗-algebra. Moreover, we study some relationships between synaptic algebras and so-called generalized Hermitian algebras.

  7. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  8. Concurrent gradients of ribbon volume and AMPA-receptor patch volume in cochlear afferent synapses on gerbil inner hair cells.

    Science.gov (United States)

    Zhang, Lichun; Engler, Sina; Koepcke, Lena; Steenken, Friederike; Köppl, Christine

    2018-07-01

    The Mongolian gerbil is a classic animal model for age-related hearing loss. As a prerequisite for studying age-related changes, we characterized cochlear afferent synaptic morphology in young adult gerbils, using immunolabeling and quantitative analysis of confocal microscopic images. Cochlear wholemounts were triple-labeled with a hair-cell marker, a marker of presynaptic ribbons, and a marker of postsynaptic AMPA-type glutamate receptors. Seven cochlear positions covering an equivalent frequency range from 0.5 - 32 kHz were evaluated. The spatial positions of synapses were determined in a coordinate system with reference to their individual inner hair cell. Synapse numbers confirmed previous reports for gerbils (on average, 20-22 afferents per inner hair cell). The volumes of presynaptic ribbons and postsynaptic glutamate receptor patches were positively correlated: larger ribbons associated with larger receptor patches and smaller ribbons with smaller patches. Furthermore, the volumes of both presynaptic ribbons and postsynaptic receptor patches co-varied along the modiolar-pillar and the longitudinal axes of their hair cell. The gradients in ribbon volume are consistent with previous findings in cat, guinea pig, mouse and rat and further support a role in differentiating the physiological properties of type I afferents. However, the positive correlation between the volumes of pre- and postsynaptic elements in the gerbil is different to the opposing gradients found in the mouse, suggesting species-specific differences in the postsynaptic AMPA receptors that are unrelated to the fundamental classes of type I afferents. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Ruptured Cornual Monochorionic Monoamniotic Twin Ectopic ...

    African Journals Online (AJOL)

    A high index of suspicion for ectopic pregnancy in women of reproductive age who presented with history of amenorrhea and lower abdominal pains could prove useful in making a diagnosis of ectopic pregnancy. The usefulness of ultrasonography has also been demonstrated. Key Words: Monochorionic monoamniotic, ...

  10. Ectopic pancreas with pseudocyst and pseudoaneurysm formation

    International Nuclear Information System (INIS)

    Surov, A.; Hainz, M.; Hinz, L.; Holzhausen, H.-J.; Finke, R.; Spielmann, R.-P.; Kunze, C.

    2009-01-01

    Ectopic pancreas is a rare congenital anomaly. It is usually asymptomatic, or presents with non specific gastrointestinal symptoms. We describe here a case of ectopic pancreas in the gastric antrum, with pseudocyst and pseudoaneurysm formation. This entity has not been reported previously in the literature.

  11. Ectopic pancreas in a giant mediastinal cyst

    NARCIS (Netherlands)

    Li, Wilson W.; van Boven, Wim Jan; Jurhill, Roy R.; Bonta, Peter I.; Annema, Jouke T.; de Mol, Bas A.

    2016-01-01

    Ectopic pancreas located in the mediastium is an extremely rare anomaly. We present a case of an ectopic pancreas located in a giant mediastinal cyst in an 18-year-old man. He presented with symptoms of dyspnea due to external compression of the cyst on the left main bronchus. Complete surgical

  12. Minimally Invasive Management of Ectopic Pancreas.

    Science.gov (United States)

    Vitiello, Gerardo A; Cavnar, Michael J; Hajdu, Cristina; Khaykis, Inessa; Newman, Elliot; Melis, Marcovalerio; Pachter, H Leon; Cohen, Steven M

    2017-03-01

    The management of ectopic pancreas is not well defined. This study aims to determine the prevalence of symptomatic ectopic pancreas and identify those who may benefit from treatment, with a particular focus on robotically assisted surgical management. Our institutional pathology database was queried to identify a cohort of ectopic pancreas specimens. Additional clinical data regarding clinical symptomatology, diagnostic studies, and treatment were obtained through chart review. Nineteen cases of ectopic pancreas were found incidentally during surgery for another condition or found incidentally in a pathologic specimen (65.5%). Eleven patients (37.9%) reported prior symptoms, notably abdominal pain and/or gastrointestinal bleeding. The most common locations for ectopic pancreas were the duodenum and small bowel (31% and 27.6%, respectively). Three out of 29 cases (10.3%) had no symptoms, but had evidence of preneoplastic changes on pathology, while one harbored pancreatic cancer. Over the years, treatment of ectopic pancreas has shifted from open to laparoscopic and more recently to robotic surgery. Our experience is in line with existing evidence supporting surgical treatment of symptomatic or complicated ectopic pancreas. In the current era, minimally invasive and robotic surgery can be used safely and successfully for treatment of ectopic pancreas.

  13. Localization of ectopic gastric mucosa by scintigraphy

    International Nuclear Information System (INIS)

    D'Alonzo, W.A. Jr.

    1988-01-01

    When gastric mucosal tissue occurs outside of the confines of the stomach, it is termed ectopic or heterotopic. Ectopic gastric mucosa may be found within Meckel's diverticulum, duplications of the alimentary tract, and Barrett's esophagus. In addition, a surgeon may inadvertently leave behind antral gastric mucosa while performing a partial gastrectomy for peptic ulcer disease (i.e., retained gastric antrum). It is important to detect the presence and location of ectopic mucosa because acid and pepsin secretion may cause ulceration in the adjacent tissue resulting in serious complications. The only currently available specific diagnostic technique for detecting ectopic gastric mucosa is pertechnetate Tc 99m (TcO 4- ) scintigraphy. This chapter reviews the functional anatomy of gastric mucosa, the mechanism of TcO 4 - localization, the various entities containing ectopic gastric mucosa, and the methods and results of TcO 4 - scanning for these disorders

  14. Ovarian Ectopic Pregnancy: a Rare Case Report

    Directory of Open Access Journals (Sweden)

    N Lotfian

    2017-02-01

    Full Text Available Background and aim: Ovarian pregnancy is an uncommon form of ectopic pregnancy which usually diagnosed so late. The aim of this study is to report a case of ovarian ectopic pregnancy Case presentation: A 19 years old woman, with a history of polycystic ovary, first pregnancy, gestation age 9 weeks and 4 days, visited the doctor. She was complaining of severe abdomen pain and vaginal spotting and she was bedridden because of threatened miscarriage. She had discharged from hospital with progesterone suppository prescription. Requesting a transvaginal ultrasound and heterogeneous echogenic mass (size18×8/5 was shown near the left ovary. It was shown as ectopic pregnancy. The patient was hospitalized by ectopic pregnancy in ovary diagnosis and she was treated by methotrexate. Conclusion: In pregnant women that complain of bleeding and spotting in early pregnancy, in addition to threatened abortion, ectopic pregnancy should exist even in the absence of clinical symptoms, should be considered.

  15. Moral absolutism and ectopic pregnancy.

    Science.gov (United States)

    Kaczor, C

    2001-02-01

    If one accepts a version of absolutism that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the absolutism mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate.

  16. Structure and magnetic properties of Alnico ribbons

    Science.gov (United States)

    Zhang, Ce; Li, Ying; Han, Xu-Hao; Du, Shuai-long; Sun, Ji-bing; Zhang, Ying

    2018-04-01

    Al-Ni-Co alloy has been widely applied in various industrial fields due to its excellent thermal and magnetic stability. In this paper, new Al-Ni-Co ribbons are prepared by simple processes combining melt-spinning with annealing, and their phase transition, microstructure and magnetic properties are studied. The results show that after as-spun ribbons are annealed, the grain size of ribbons increases from 1.1 ± 0.3 μm to 4.8 ± 0.8 μm, but still much smaller than that of the bulk Al-Ni-Co alloy manufactured by traditional technologies. In addition, some rod-like Al70Co20Ni10-type, Al9Co2-type and Fe2Nb-type phases are precipitated at grain boundaries; simultaneously, the distinct spinodal decomposition microstructure with periodic ingredient variation is thoroughly formed in all grains by the reaction of α → α1 + α2. Furthermore, the α1 and α2 distribute alternately like a maze, the Fe-Co-rich α1 phase holds 35.9-47.3 vol%, while the Al-Ni-rich α2 phase occupies the rest. Finally, the coercivity of annealed ribbons can reach to 485.3 ± 76.6 Oe. If the annealed ribbons are further aged at 560 °C, their Hc even increases to 738.1 ± 81.0 Oe. The coercivity mechanism is discussed by the combination of microstructure and domain structure.

  17. Transvaginal sonographic findings of the ectopic pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Soon Ae; Youn, Chang Seon; Han, Sei Yul; Cho, Joo Youn; Chang, Sang Sik; Cha, Kwang Yul; Cha, Kyung Sub [Cha Women' s Hospital, Sungnam (Korea, Republic of)

    1989-08-15

    Transvaginal(TV) sonography uses high-frequency transducer and allows access to the uterus and adnexa, provides better resolution and more accurate diagnosis of ectopic pregnancy. To determine the value and the utility of TV sonography for a suspected ectopic pregnancy, we studied 56 women during 4 months from January to April 1989. Of 56 patients 46 had an surgically confirmed ectopic pregnancy, 5 had not an ectopic pregnancy and 5 had not follow up. TV sonography provides definite sonographic diagnosis of ectopic pregnancy including an extrauterine gestational sac 34 cases(74%), extrauterine embryo 9 caes(19.7%), hematosalpinx 10 cases(21.7%). Overall adnexal mass was detected in 38 cases(82.6%) at initial TV sonography and in 44 cases(95.6%) at follow up TV sonography. Additional findings were uterine decidual reaction 19 cases(41.3%), pseudo G-sac 4 cases(8.7%), cul-de-sac fluid 42 cases(91.2%). Follow-up TV sonography showed newly developed or growing adnexal mass in 8 among 9 cases. False positive 5 cases were two ovarian cysts, one incomplete abortion, two parametrial thickening due to previous ectopic pregnancy and salpingectomy. TV sonography may improve the govality of patient management by early diagnosis and early surgical treatment, so may preserve fertility. In conclusion, we may suggest that TV sonography is an integral part of diagnostic modality in suspected ectopic pregnancy.

  18. Transvaginal sonographic findings of the ectopic pregnancy

    International Nuclear Information System (INIS)

    Jun, Soon Ae; Youn, Chang Seon; Han, Sei Yul; Cho, Joo Youn; Chang, Sang Sik; Cha, Kwang Yul; Cha, Kyung Sub

    1989-01-01

    Transvaginal(TV) sonography uses high-frequency transducer and allows access to the uterus and adnexa, provides better resolution and more accurate diagnosis of ectopic pregnancy. To determine the value and the utility of TV sonography for a suspected ectopic pregnancy, we studied 56 women during 4 months from January to April 1989. Of 56 patients 46 had an surgically confirmed ectopic pregnancy, 5 had not an ectopic pregnancy and 5 had not follow up. TV sonography provides definite sonographic diagnosis of ectopic pregnancy including an extrauterine gestational sac 34 cases(74%), extrauterine embryo 9 caes(19.7%), hematosalpinx 10 cases(21.7%). Overall adnexal mass was detected in 38 cases(82.6%) at initial TV sonography and in 44 cases(95.6%) at follow up TV sonography. Additional findings were uterine decidual reaction 19 cases(41.3%), pseudo G-sac 4 cases(8.7%), cul-de-sac fluid 42 cases(91.2%). Follow-up TV sonography showed newly developed or growing adnexal mass in 8 among 9 cases. False positive 5 cases were two ovarian cysts, one incomplete abortion, two parametrial thickening due to previous ectopic pregnancy and salpingectomy. TV sonography may improve the govality of patient management by early diagnosis and early surgical treatment, so may preserve fertility. In conclusion, we may suggest that TV sonography is an integral part of diagnostic modality in suspected ectopic pregnancy

  19. Application Potential of Nanocrystalline Ribbons Still Pending

    Science.gov (United States)

    Butvin, Pavol; Butvinová, Beata; Švec, Peter; Sitek, Jozef

    2010-09-01

    Nanocrystalline soft-magnetic ribbons promised a wide-spread practical use when introduced at the beginning of nineties. After 20 years of extensive research there are still unclear material problems which are thought to be the principal reason why these materials show but marginal use. Poorly controllable magnetic anisotropy due to spontaneous intrinsic macroscopic stress that comes from an inevitable heterogeneity of the ribbon materials is pointed to in this work. Certain stress-based mechanisms are shown to induce the unintended anisotropy in the already familiar Finemets as well as in the newer Hitperms. Hysteresis loops, domain structure and power loss is used to reveal the anisotropy consequences and particular connected but still unanswered questions are pinpointed.

  20. Oxygen measurements in thin ribbon silicon

    Energy Technology Data Exchange (ETDEWEB)

    Hyland, S L; Ast, D G; Baghdadi, A

    1987-03-01

    The oxygen content of thin silicon ribbons grown by the dendritic web technique was measured using a modification of the ASTM method based on Fourier transform infrared spectroscopy. Web silicon was found to have a high oxygen content, ranging from 13 to 19 ppma, calculated from the absorption peak associated with interstitial oxygen and using the new ASTM conversion coefficient. The oxygen concentration changed by about 10% along the growth direction of the ribbon. In some samples, a shoulder was detected on the absorption peak. A similar shoulder in Czochralski grown material has been variously interpreted in the literature as due to a complex of silicon, oxygen, and vacancies, or to a phase of SiO/sub 2/ developed along dislocations in the material. In the case of web silicon, it is not clear which is the correct interpretation.

  1. Pseudo ribbon metal ion beam source

    International Nuclear Information System (INIS)

    Stepanov, Igor B.; Ryabchikov, Alexander I.; Sivin, Denis O.; Verigin, Dan A.

    2014-01-01

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface

  2. Pseudo ribbon metal ion beam source.

    Science.gov (United States)

    Stepanov, Igor B; Ryabchikov, Alexander I; Sivin, Denis O; Verigin, Dan A

    2014-02-01

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface.

  3. Ectopic cervical thymoma in a patient with Myasthenia gravis

    Directory of Open Access Journals (Sweden)

    Chang Hung

    2011-07-01

    Full Text Available Abstract Ectopic cervical thymoma is rare and is often misdiagnosed as a thyroid tumor or other malignancy. Ectopic thymic tissue can be found along the entire thymic descent path during embryogenesis. However, a thymoma arising from such ectopic thymic tissue is extremely rare. Herein we report a patient with ectopic cervical thymoma and myasthenia gravis (MG and discuss the management.

  4. Ectopic Axillary Breast during Systemic Lupus

    Directory of Open Access Journals (Sweden)

    Besma Ben Dhaou

    2012-01-01

    Full Text Available Many breast changes may occur in systemic lupus erythematosus. We report a 41-year-old woman with lupus who presented three years after the onset of lupus an ectopic mammary gland confirmed by histological study.

  5. MR features of ectopic pregnancy

    International Nuclear Information System (INIS)

    Tamai, Ken; Togashi, Kaori; Koyama, Takashi

    2007-01-01

    Ectopic pregnancy (EP), in which a fertilized ovum implants outside the uterine cavity, is the leading cause of pregnancy-related death in the first trimester. EP is usually suspected by a positive pregnancy test and an empty uterus on transvaginal sonography (TVS). Although TVS is the initial modality of choice, it may occasionally fail to demonstrate the implantation site. When TVS findings are indeterminate, magnetic resonance imaging (MRI) may provide better delineation of the focus of EP owing to its excellent tissue contrast. The key MRI features of EP include gestational sac (GS)-like structures that typically appear as a cystic sac-like structure, frequently associated with surrounding acute hematoma of distinct low intensity on T2-weighted images. In tubal pregnancy, an enhanced tubal wall on postcontrast images may be another diagnostic finding. Ruptured EP is inevitably associated with acute hematoma outside these structures. In intrauterine EP, recognition of the relationship between GS-like structure and the myometrium can aid in differentiating from normal pregnancy. Diagnostic pitfalls include heterotopic pregnancy, decidual changes in endometrial cyst and theca lutein cysts mimicking GS-like structures. Knowledge of a spectrum of clinical and MRI features of EP is essential for establishing an accurate diagnosis and determining appropriate management. (orig.)

  6. Cornual ectopic pregnancy; Report of three cases

    OpenAIRE

    espitia de la hoz, Franklin jose

    2014-01-01

    Ectopic pregnancy is the implantation of the fertilized ovum outside the uterine cavity,its main location is in the tube. Non tubal forms include: the cornual pregnancy, ovarianpregnancy, abdominal pregnancy, cervical pregnancy, intraligamentary pregnancy andpregnancy in a rudimentary uterine horn. Three cases of cornual ectopic pregnancyare described. Surgical management, with wedge resection via laparotomy trophoblast,without resorting to hysterectomy was performed, correlating histopatholo...

  7. Dual ectopic thyroid associated with thyroid hemiagenesis.

    Science.gov (United States)

    Nakamura, Shigenori; Masuda, Teruyuki; Ishimori, Masatoshi

    2018-01-01

    We report a case of a 15-year-old girl with a midline neck mass that was first noted 2 or 3 years previously. She had been treated with levothyroxine (L-T4) for congenital hypothyroidism until 11 years of age. Ultrasonography revealed an atrophic right thyroid (1.0 × 1.6 × 2.6 cm in size) and a mass (2.3 × 1.0 × 3.5 cm in size) in the upper part of the neck. No left lobe of the thyroid was detected. On further evaluation, Tc-99m pertechnetate thyroid scintigraphy and CT showed ectopic thyroid tissue in the lingual region and infrahyoid region. Thus, she was diagnosed as having dual ectopic thyroid and thyroid hemiagenesis. The atrophic right thyroid was thought be non-functional. Treatment with L-T4 was started to reduce the size of the dual ectopic thyroid tissue. This may be the first reported case of dual ectopic thyroid associated with hemiagenesis detected only by ultrasonography. Ultrasonography can confirm the presence or absence of orthotopic thyroid tissue in patients with ectopic thyroid.The cause of congenital hypothyroidism should be examined.Clinical manifestation of ectopic thyroid may appear when the treatment with L-T4 is discontinued.Annual follow-up is needed in all children when their thyroid hormone replacement is stopped.

  8. Are All Flare Ribbons Simply Connected to the Corona?

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Philip G. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Paraschiv, Alin; Lacatus, Daniela; Donea, Alina [Monash Center for Astrophysics, School of Mathematical Science, Monash University, Victoria 3800 (Australia); Lindsey, Charlie, E-mail: judge@ucar.edu, E-mail: alina.donea@monash.edu, E-mail: alin.paraschiv@monash.edu, E-mail: daniela.lacatus@monash.edu, E-mail: indsey@cora.nwra.com [Northwest Research Associates, 3380 Mitchell Lane, Boulder, CO 80301 (United States)

    2017-04-01

    We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode , Solar Dynamics Observatory , and IRIS missions. While most ribbons appear connected to the corona and overlie regions of significant vertical magnetic field, we examine one ribbon with no clear evidence for such connections. Evolving horizontal magnetic fields seen with Hinode suggest that reconnection with preexisting fields below the corona can explain the data. The identification of just one, albeit small, ribbon, with no apparent connection to the corona, leads us to conclude that at least two mechanisms are responsible for the heating that leads to flare ribbon emission.

  9. Plastic deformation of silicon dendritic web ribbons during the growth

    Science.gov (United States)

    Cheng, L. J.; Dumas, K. A.; Su, B. M.; Leipold, M. H.

    1984-01-01

    The distribution of slip dislocations in silicon dendritic web ribbons due to plastic deformation during the cooling phase of the growth was studied. The results show the existence of two distinguishable stress regions across the ribbon formed during the plastic deformation stage, namely, shear stress at the ribbon edges and tensile stress at the middle. In addition, slip dislocations caused by shear stress near the edges appear to originate at the twin plane.

  10. ANALYSIS OF RISK FACTORS ECTOPIC PREGNANCY

    Directory of Open Access Journals (Sweden)

    Budi Santoso

    2017-04-01

    Full Text Available Introduction: Ectopic pregnancy is a pregnancy with extrauterine implantation. This situation is gynecologic emergency that contributes to maternal mortality. Therefore, early recognition, based on identification of the causes of ectopic pregnancy risk factors, is needed. Methods: The design descriptive observational. The samples were pregnant women who had ectopic pregnancy at Maternity Room, Emergency Unit, Dr. Soetomo Hospital, Surabaya, from 1 July 2008 to 1 July 2010. Sampling technique was total sampling using medical records. Result: Patients with ectopic pregnancy were 99 individuals out of 2090 pregnant women who searched for treatment in Dr. Soetomo Hospital. However, only 29 patients were accompanied with traceable risk factors. Discussion:. Most ectopic pregnancies were in the age group of 26-30 years, comprising 32 patients (32.32%, then in age groups of 31–35 years as many as 25 patients (25.25%, 18 patients in age group 21–25 years (18.18%, 17 patients in age group 36–40 years (17.17%, 4 patients in age group 41 years and more (4.04%, and the least was in age group of 16–20 years with 3 patients (3.03%. A total of 12 patients with ectopic pregnancy (41.38% had experience of abortion and 6 patients (20.69% each in groups of patients with ectopic pregnancy who used family planning, in those who used family planning as well as ectopic pregnancy patients with history of surgery. There were 2 patients (6.90% of the group of patients ectopic pregnancy who had history of surgery and history of abortion. The incidence rate of ectopic pregnancy was 4.73%, mostly in the second gravidity (34.34%, whereas the nulliparous have the highest prevalence of 39.39%. Acquired risk factors, i.e. history of operations was 10.34%, patients with family planning 20.69%, patients with history of abortion 41.38%, patients with history of abortion and operation 6.90% patients with family and history of abortion was 20.69%.

  11. Role of the mouse retinal photoreceptor ribbon synapse in visual motion processing for optokinetic responses.

    Science.gov (United States)

    Sugita, Yuko; Araki, Fumiyuki; Chaya, Taro; Kawano, Kenji; Furukawa, Takahisa; Miura, Kenichiro

    2015-01-01

    The ribbon synapse is a specialized synaptic structure in the retinal outer plexiform layer where visual signals are transmitted from photoreceptors to the bipolar and horizontal cells. This structure is considered important in high-efficiency signal transmission; however, its role in visual signal processing is unclear. In order to understand its role in visual processing, the present study utilized Pikachurin-null mutant mice that show improper formation of the photoreceptor ribbon synapse. We examined the initial and late phases of the optokinetic responses (OKRs). The initial phase was examined by measuring the open-loop eye velocity of the OKRs to sinusoidal grating patterns of various spatial frequencies moving at various temporal frequencies for 0.5 s. The mutant mice showed significant initial OKRs with a spatiotemporal frequency tuning (spatial frequency, 0.09 ± 0.01 cycles/°; temporal frequency, 1.87 ± 0.12 Hz) that was slightly different from the wild-type mice (spatial frequency, 0.11 ± 0.01 cycles/°; temporal frequency, 1.66 ± 0.12 Hz). The late phase of the OKRs was examined by measuring the slow phase eye velocity of the optokinetic nystagmus induced by the sinusoidal gratings of various spatiotemporal frequencies moving for 30 s. We found that the optimal spatial and temporal frequencies of the mutant mice (spatial frequency, 0.11 ± 0.02 cycles/°; temporal frequency, 0.81 ± 0.24 Hz) were both lower than those in the wild-type mice (spatial frequency, 0.15 ± 0.02 cycles/°; temporal frequency, 1.93 ± 0.62 Hz). These results suggest that the ribbon synapse modulates the spatiotemporal frequency tuning of visual processing along the ON pathway by which the late phase of OKRs is mediated.

  12. Role of the mouse retinal photoreceptor ribbon synapse in visual motion processing for optokinetic responses.

    Directory of Open Access Journals (Sweden)

    Yuko Sugita

    Full Text Available The ribbon synapse is a specialized synaptic structure in the retinal outer plexiform layer where visual signals are transmitted from photoreceptors to the bipolar and horizontal cells. This structure is considered important in high-efficiency signal transmission; however, its role in visual signal processing is unclear. In order to understand its role in visual processing, the present study utilized Pikachurin-null mutant mice that show improper formation of the photoreceptor ribbon synapse. We examined the initial and late phases of the optokinetic responses (OKRs. The initial phase was examined by measuring the open-loop eye velocity of the OKRs to sinusoidal grating patterns of various spatial frequencies moving at various temporal frequencies for 0.5 s. The mutant mice showed significant initial OKRs with a spatiotemporal frequency tuning (spatial frequency, 0.09 ± 0.01 cycles/°; temporal frequency, 1.87 ± 0.12 Hz that was slightly different from the wild-type mice (spatial frequency, 0.11 ± 0.01 cycles/°; temporal frequency, 1.66 ± 0.12 Hz. The late phase of the OKRs was examined by measuring the slow phase eye velocity of the optokinetic nystagmus induced by the sinusoidal gratings of various spatiotemporal frequencies moving for 30 s. We found that the optimal spatial and temporal frequencies of the mutant mice (spatial frequency, 0.11 ± 0.02 cycles/°; temporal frequency, 0.81 ± 0.24 Hz were both lower than those in the wild-type mice (spatial frequency, 0.15 ± 0.02 cycles/°; temporal frequency, 1.93 ± 0.62 Hz. These results suggest that the ribbon synapse modulates the spatiotemporal frequency tuning of visual processing along the ON pathway by which the late phase of OKRs is mediated.

  13. An unusual case of ectopic ACTH syndrome.

    Science.gov (United States)

    Willhauck, M J; Pöpperl, G; Rachinger, W; Giese, A; Auernhammer, C J; Spitzweg, C

    2012-02-01

    Ectopic ACTH-syndrome is a rare cause of Cushing's disease. Despite extensive diagnostic procedures the source of ACTH secretion often remains occult. This case describes a 45-year old woman with an ectopic Cushing's syndrome. Extensive imaging procedures including CT scan of chest and abdomen, octreotide scan and MRI of the chest and pituitary did not reveal the source of ACTH secretion. In consideration of an occult source of ACTH secretion we started a therapeutic trial with cabergoline (0.5 mg/d), a dopamine receptor agonist, which has been shown to be effective in ectopic Cushing's syndrome. 2 months after cabergoline treatment had been initiated, ACTH and cortisol levels normalized in association with significant improvement of the clinical symptoms. During follow-up a [(68)Ga-DOTA-dPhe(1), Tyr(3)]-octreotate ([(68)Ga-DOTA]-TATE) PET-CT was performed revealing a somatostatin receptor positive lesion in the right sphenoidal sinus suggesting the source of ACTH secretion. The patient was cured by transnasal resection of the polypoid lesion, which was immunohistochemically characterized as an ACTH-positive neuroendocrine tumor. This case report demonstrates the management of ectopic ACTH-syndrome by molecularly -targeted therapy with dopamine receptor -agonists as well as improved detection of the ectopic ACTH source by novel imaging modalities, such as [(68)Ga-DOTA]-TATE PET specifically targeting somatostatin receptor subtype-2 with high affinity. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

  14. Scintillating ribbon x-ray detector

    International Nuclear Information System (INIS)

    Kinchen, B.E.; Rogers, A.

    1995-01-01

    A patent in the early 1970's by Aerojet Corporation in Sacramento, CA put forth the idea of using an array of scintillating fibers for x-ray detection and imaging. In about 1975, Pratt and Whitney Aircraft in East Hartford, CT designed and manufactured an imaging system based on the patent. The device was 1.75 in thick in the direction of the x-ray beam and about 4 in. by 4 in. square. The device was used with a 8 MeV x-ray source to image and measure internal clearances within operating aircraft, gas turbines engines. There are significant advantages of fiber optic detectors in x-ray detection. However, the advantages are often outweighed by the disadvantages. Two of the advantages of scintillating fiber optic x-ray detectors are: (1) high limiting spatial frequency -- between 20 and 25 lp/mm; and (2) excellent x-ray stopping power -- they can be made thick and retain spatial resolution. In traditional fiber optic detectors the x-rays are oriented parallel to the long axis of the fiber. For the scintillating ribbon x-ray sensor, the x-rays are oriented normal to the fiber long axis. This ribbon sensor technique has a number of advantages over the two current radiographic techniques digital x-radiography and x-ray film: The main advantage the ribbon has is size and shape. It can be as thin as 0.05 in., virtually any width or length, and flexible. Once positioned in a given location, 20 to 100 square inches of the object being inspected can be imaged with a single x-ray beam sweep. It is clear that conventional digital cameras do not lend themselves to placement between walls of aircraft structures or similar items requiring x-ray inspections. A prototype scintillating ribbon x-ray sensor has been fabricated and tested by Synergistic Detector Designs. Images were acquired on corrosion test panels of aluminum fabricated by Iowa State University

  15. Surgical treatment for ectopic atrial tachycardia.

    Science.gov (United States)

    Graffigna, A; Vigano, M; Pagani, F; Salerno, G

    1992-08-01

    Atrial tachycardia is an infrequent but potentially dangerous arrhythmia which often determines cardiac enlargement. Surgical ablation of the arrhythmia is effective and safe, provided a careful atrial mapping is performed and the surgical technique is tailored to the individual focus location. Eight patients underwent surgical ablation of ectopic atrial tachycardia between 1977 and 1990. Different techniques were adopted for each patient according to the anatomical location of the focus and possibly associated arrhythmias. Whenever possible, a closed heart procedure was chosen. In 1 patient a double focal origin was found and treated by separate procedures. In 1 patient with ostium secundum atrial septal defect and atrial flutter, surgical isolation of the right appendage and the ectopic focus was performed. In all patients ectopic atrial tachycardia was ablated with maintenance of the sinoatrial and atrioventricular nodal function as well as internodal conduction. In follow-up up to December 1991, no recurrency was recorded.

  16. Modeling of inter-ribbon tunneling in graphene

    OpenAIRE

    Van de Put, Maarten L.; Vandenberghe, William G.; Sorée, Bart; Magnus, Wim; Fischetti, Massimo

    2015-01-01

    The tunneling current between two crossed graphene ribbons is described invoking the empirical pseudopotential approximation and the Bardeen transfer Hamiltonian method. Results indicate that the density of states is the most important factor determining the tunneling current between small (nm) ribbons. The quasi-one dimensional nature of graphene nanoribbons is shown to result in resonant tunneling.

  17. [Management of ectopic pregnancy in Conakry, Guinea].

    Science.gov (United States)

    Sy, T; Diallo, Y; Toure, A; Diallo, F B; Balde, A A; Hyjazi, Y; Diallo, M S

    2009-12-01

    Ectopic pregnancy is one of the most frequent hemorrhagic emergencies encountered in gynecology and obstetrics. The purpose of this 16-month descriptive prospective study at the Ignace Deen Gynecology-Obstetric clinic at Conakry University Hospital in Guinea was to assess diagnostic techniques and therapeutic attitudes regarding ectopic pregnancy in a low-resource setting. The frequency of ectopic pregnancy was 1.4%. Mean patient age was 28.9 years. Ectopic pregnancy was often observed at the second or third pregnancy (47.1%) in women who were giving birth for the second or third time (36.0%) and had a history of sexually transmitted infections (88.2%) or abortions (43.1%). Most women had no schooling (60.8 %), were poor and lived in a marital home (86.3%). Presenting symptoms included the classic triad of amenorrhea (98.0%), abdominopelvic pain (92.2%), and vaginal bleeding (62.7%). Definitive diagnosis was achieved by ultrasound examination in 76.6% of cases and by puncture of the Douglas pouch in 84%. The most frequent site of ectopic pregnancy was the ampulla of the uterine tube (66.9%). Abdominal and ovarian pregnancy was observed in 3 and 4 of the 51 cases respectively. Surgical management was performed in all cases. The most frequent procedure was salpingectomy (80.3%). Proper treatment of sexually transmitted infections (STI), start-up of post-abortion care facilities, and provision of information during early consultation at the first signs of pregnancy would help reduce the frequency and improve the prognosis of ectopic pregnancy.

  18. MAGUKs: multifaceted synaptic organizers.

    Science.gov (United States)

    Won, Sehoon; Levy, Jon M; Nicoll, Roger A; Roche, Katherine W

    2017-04-01

    The PSD-95 family of proteins, known as MAGUKs, have long been recognized to be central building blocks of the PSD. They are categorized as scaffolding proteins, which link surface-expressed receptors to the intracellular signaling molecules. Although the four members of the PSD-95 family (PSD-95, PSD-93, SAP102, and SAP97) have many shared roles in regulating synaptic function, recent studies have begun to delineate specific binding partners and roles in plasticity. In the current review, we will highlight the conserved and unique roles of these proteins. Published by Elsevier Ltd.

  19. Treatment of ectopic first permanent molar teeth.

    LENUS (Irish Health Repository)

    Hennessy, Joe

    2012-11-01

    Ectopic eruption of the first permanent molar is a relatively common occurence in the developing dentition. A range of treatment options are available to the clinician provided that diagnosis is made early. Non-treatment can result in premature exfoliation of the second primary molar, space loss and impaction of the second premolar. This paper will describe the management of ectopic first permanent molars, using clinical examples to illustrate the available treatment options. CLINICAL RELEVANCE: This paper is relevant to every general dental practitioner who treats patients in mixed dentition.

  20. Simple ectopic kidney in three dogs.

    Science.gov (United States)

    Choi, Jiyoung; Lee, Heechun; Lee, Youngwon; Choi, Hojung

    2012-10-01

    Simple ectopic kidney was diagnosed in three dogs by means of radiography and ultrasonography. A 2-year-old castrated male Schnauzer, a 13-year-old female Schnauzer and a 9-year-old male Jindo were referred with vomiting, hematuria and ocular discharge, respectively. In all three dogs, oval-shaped masses with soft tissue density were observed in the mid to caudal abdomen bilaterally or unilaterally, and kidney silhouettes were not identified at the proper anatomic places on abdominal radiographs. Ultrasonography confirmed the masses were malpositioned kidney. The ectopic kidneys had relatively small size, irregular shape and short ureter but showed normal function on excretory urography.

  1. Treatment of ectopic first permanent molar teeth.

    Science.gov (United States)

    Hennessy, Joe; Al-Awadhi, E A; Dwyer, Lian O; Leith, Rona

    2012-11-01

    Ectopic eruption of the first permanent molar is a relatively common occurence in the developing dentition. A range of treatment options are available to the clinician provided that diagnosis is made early. Non-treatment can result in premature exfoliation of the second primary molar, space loss and impaction of the second premolar. This paper will describe the management of ectopic first permanent molars, using clinical examples to illustrate the available treatment options. This paper is relevant to every general dental practitioner who treats patients in mixed dentition.

  2. Electrostatics-Driven Hierarchical Buckling of Charged Flexible Ribbons.

    Science.gov (United States)

    Yao, Zhenwei; Olvera de la Cruz, Monica

    2016-04-08

    We investigate the rich morphologies of an electrically charged flexible ribbon, which is a prototype for many beltlike structures in biology and nanomaterials. Long-range electrostatic repulsion is found to govern the hierarchical buckling of the ribbon from its initially flat shape to its undulated and out-of-plane twisted conformations. In this process, the screening length is the key controlling parameter, suggesting that a convenient way to manipulate the ribbon morphology is simply to change the salt concentration. We find that these shapes originate from the geometric effect of the electrostatic interaction, which fundamentally changes the metric over the ribbon surface. We also identify the basic modes by which the ribbon reshapes itself in order to lower the energy. The geometric effect of the physical interaction revealed in this Letter has implications for the shape design of extensive ribbonlike materials in nano- and biomaterials.

  3. Mammalian Vestibular Macular Synaptic Plasticity: Results from SLS-2 Spaceflight

    Science.gov (United States)

    Ross, Muriel D.D.

    1994-01-01

    The effects of exposure to microgravity were studied in rat utricular maculas collected inflight (IF, day 13), post-flight on day of orbiter landing (day 14, R+O) and after 14 days (R+ML). Controls were collected at corresponding times. The objectives were 1) to learn whether hair cell ribbon synapses counts would be higher in tissues collected in space than in tissues collected postflight during or after readaptation to Earth's gravity; and 2) to compare results with those of SLS-1. Maculas were fixed by immersion, micro-dissected, dehydrated and prepared for ultrastructural study by usual methods. Synapses were counted in 100 serial sections 150 nm thick and were located to specific hair cells in montages of every 7th section. Counts were analyzed for statistical significance using analysis of variance. Results in maculas of IF dissected rats, one 13 day control (IFC), and one R + 0 rat have been analyzed. Study of an R+ML macula is nearly completed. For type I cells, IF mean is 2.3 +/-1.6; IFC mean is 1.6 +/-1.0; R+O mean is 2.3 +/- 1.6. For type II cells, IF mean is 11.4 +/- 17.1; IFC mean is 5.5 +/-3.5; R+O mean is 10.1 +/- 7.4. The difference between IF and IFC means for type I cells is statistically significant (p less than 0.0464). For type It cells, IF compared to IFC means, p less than 0.0003; and for IFC to R+O means, p less than 0.0139. Shifts toward spheres (p less than 0.0001) and pairs (p less than 0.0139) were significant in type II cells of IF rats. The results are largely replicating findings from SLS-1 and indicate that spaceflight affects synaptic number, form and distribution, particularly in type II hair cells. The increases in synaptic number and in sphere-like ribbons are interpreted to improve synaptic efficacy, to help return afferent discharges to a more normal state. Findings indicate that a great capacity for synaptic plasticity exists in mammalian gravity sensors, and that this plasticity is more dominant in the local circuitry. The

  4. Graphene ribbon growth on structured silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Stoehr, Alexander; Link, Stefan; Starke, Ulrich [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Baringhaus, Jens; Aprojanz, Johannes; Tegenkamp, Christoph [Institut fuer Festkoerperphysik, Leibniz Universitaet Hannover (Germany); Niu, Yuran [MAX IV Laboratory, Lund University (Sweden); present address: School of Physics and Astronomy, Cardiff University (United Kingdom); Zakharov, Alexei A. [MAX IV Laboratory, Lund University (Sweden); Chen, Chaoyu; Avila, Jose; Asensio, Maria C. [Synchrotron SOLEIL and Universite Paris-Saclay, Gif sur Yvette (France)

    2017-11-15

    Structured Silicon Carbide was proposed to be an ideal template for the production of arrays of edge specific graphene nanoribbons (GNRs), which could be used as a base material for graphene transistors. We prepared periodic arrays of nanoscaled stripe-mesas on SiC surfaces using electron beam lithography and reactive ion etching. Subsequent epitaxial graphene growth by annealing is differentiated between the basal-plane mesas and the faceting stripe walls as monitored by means of atomic force microscopy (AFM). Microscopic low energy electron diffraction (μ-LEED) revealed that the graphene ribbons on the facetted mesa side walls grow in epitaxial relation to the basal-plane graphene with an armchair orientation at the facet edges. The π-band system of the ribbons exhibits linear bands with a Dirac like shape corresponding to monolayer graphene as identified by angle-resolved photoemission spectroscopy (ARPES). (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. The ribbon microphone - an educational aid: use of a ribbon microphone to teach multi-discipline computer simulation skills

    CSIR Research Space (South Africa)

    Van Wyk, Marius

    2016-07-01

    Full Text Available The ribbon microphone serves as an excellent aid to learn computer simulation and computational skills. Simulation of this seemingly simple device is all but trivial. The ribbon microphone is an all-in-one example for simulations in acoustics...

  6. Cervical Ectopic Pregnancy in Resource Deprived Areas: A Rare ...

    African Journals Online (AJOL)

    2016-06-02

    Jun 2, 2016 ... Cervical ectopic pregnancy is a rare, life threatening form of ectopic pregnancy ... cervical, resource deprived areas, difficult diagnosis, management ... drome, prior instrumentation or therapeutic abortion .... CONCLUSION.

  7. Splenic rupture masquerading ruptured ectopic pregnancy | Kigbu ...

    African Journals Online (AJOL)

    The classical triad of presentation of delayed menses, irregular vaginal bleeding and abdominal pain may not be encountered at all! Overwhelming features of abdominal pain, amenorrhea, pallor, abdominal tenderness, shifting dullness with positive pregnancy test gave a clinical diagnosis of ruptured ectopic pregnancy.

  8. Perineal Ectopic Testis in an Adult

    African Journals Online (AJOL)

    in an ectopic site outside the scrotum; such as the perineum, pubic region, dorsum of the penis, femoral region, anterior abdominal wall and the contralateral scrotum. Management is orchidopexy through an inguinal crease incision as the length of the spermatic cord is normal. We report a 26 year old man with a left perineal ...

  9. Ectopic gastric mucosa in the duodenal bulb

    International Nuclear Information System (INIS)

    Schnell, H.; Oehler, G.; Schulz, A.; Rau, W.S.; Giessen Univ.; Giessen Univ.

    1989-01-01

    The radiological and clinical findings of 12 patients with ectopic gastric mucosa in the duodenal bulb are presented. This is a defined disease with characteristic radiological features: multiple small nodular defects of the contrast medium of 1-3 mm diameter. Histology shows complete heterotopia. Pathogenesis and clinical significance are discussed with reference to the literature on this subject. (orig.) [de

  10. Synaptic electronics: materials, devices and applications.

    Science.gov (United States)

    Kuzum, Duygu; Yu, Shimeng; Wong, H-S Philip

    2013-09-27

    In this paper, the recent progress of synaptic electronics is reviewed. The basics of biological synaptic plasticity and learning are described. The material properties and electrical switching characteristics of a variety of synaptic devices are discussed, with a focus on the use of synaptic devices for neuromorphic or brain-inspired computing. Performance metrics desirable for large-scale implementations of synaptic devices are illustrated. A review of recent work on targeted computing applications with synaptic devices is presented.

  11. Synaptic electronics: materials, devices and applications

    International Nuclear Information System (INIS)

    Kuzum, Duygu; Yu, Shimeng; Philip Wong, H-S

    2013-01-01

    In this paper, the recent progress of synaptic electronics is reviewed. The basics of biological synaptic plasticity and learning are described. The material properties and electrical switching characteristics of a variety of synaptic devices are discussed, with a focus on the use of synaptic devices for neuromorphic or brain-inspired computing. Performance metrics desirable for large-scale implementations of synaptic devices are illustrated. A review of recent work on targeted computing applications with synaptic devices is presented. (topical review)

  12. Ectopic decidual reaction mimicking inguinal lymphoma on ultrasound

    DEFF Research Database (Denmark)

    Lorentzen, C.; Prangsgaard, Tina; Lorentzen, Torben

    2014-01-01

    Ectopic decidual reaction has been described in various intraperitoneal locations. We present a case of unusual ectopic decidual reaction in the groin mimicking inguinal lymphoma on ultrasound in a pregnant woman. This case contributes evidence illustrating the variability of the clinical...... presentation of ectopic decidual reaction....

  13. Ectopic decidual reaction mimicking irritable bowel syndrome: a case report.

    Directory of Open Access Journals (Sweden)

    Soraya Salehgargari

    2014-01-01

    Full Text Available Ectopic decidualization with gross involvement of the peritoneum is one of the rare findings in pregnant women particularly when ectopic decidualization disseminated as an asymptomatic intra-abdominal nodule. We present here a case of an ectopic decidualization in a 33-year-old pregnant woman with symptoms of irritable bowel syndrome during pregnancy.

  14. Observations and Numerical Modeling of the Jovian Ribbon

    Science.gov (United States)

    Cosentino, R. G.; Simon, A.; Morales-Juberias, R.; Sayanagi, K. M.

    2015-01-01

    Multiple wavelength observations made by the Hubble Space Telescope in early 2007 show the presence of a wavy, high-contrast feature in Jupiter's atmosphere near 30 degrees North. The "Jovian Ribbon," best seen at 410 nanometers, irregularly undulates in latitude and is time-variable in appearance. A meridional intensity gradient algorithm was applied to the observations to track the Ribbon's contour. Spectral analysis of the contour revealed that the Ribbon's structure is a combination of several wavenumbers ranging from k equals 8-40. The Ribbon is a dynamic structure that has been observed to have spectral power for dominant wavenumbers which vary over a time period of one month. The presence of the Ribbon correlates with periods when the velocity of the westward jet at the same location is highest. We conducted numerical simulations to investigate the stability of westward jets of varying speed, vertical shear, and background static stability to different perturbations. A Ribbon-like morphology was best reproduced with a 35 per millisecond westward jet that decreases in amplitude for pressures greater than 700 hectopascals and a background static stability of N equals 0.005 per second perturbed by heat pulses constrained to latitudes south of 30 degrees North. Additionally, the simulated feature had wavenumbers that qualitatively matched observations and evolved throughout the simulation reproducing the Jovian Ribbon's dynamic structure.

  15. Diagrammatic documentation for ribbon computing in Microsoft Office

    Directory of Open Access Journals (Sweden)

    Kaveh Farbeh-Tabrizi

    Full Text Available In 2007 Microsoft changed the graphical user interface of MS Office, and moved away from the long -established drop down menu approach to a ribbon graphical user interface. There have been mixed reactions to Microsoft\\'s ribbon interface. Ericson (2006 mentioned that even the experienced user might have difficulty adopting the interface, and Dostal (2010 concluded that the biggest issue with the Ribbon User Interface is to get accustomed to a redesigned user interface. Reaction to this change was negative among our new and current students. For years the students had tried to memorise how to apply the right commands in Microsoft Office applications by selecting the correct items from the dropdown menus of the WIMP (windows, icons, menus, pointer interface, and now that they were confronted with the new interface their confusion had begun to slow their progress down. The major effect in transition from the traditional WIMP interface to the Ribbon interface had created a difficulty for most students who had their original training with the older versions of MS Office software, as they were not able to locate the commands that they had learnt with the earlier versions of the MS Office in the new Ribbon interfaced version. The shrinking nature of the ribbon that would hide some commands on the ribbon when the resolution of the screen changes was also confusing for those students as they could not quickly locate the command they were looking for because the Ribbon had compacted them to save space. For both new students and also more experienced ones, the approach to learning the Ribbon Interface seemed to be difficult due to the fact that they had to memorise the hierarchy of tab names, group names and then the commands. This led us to enhance our current teaching methods to try to deal with this change.

  16. Ectopic ureterocele and ectopic ureter in pediatric patients; Ureterocele ectopico y ectopia ureteral en pacientes pediatricos

    Energy Technology Data Exchange (ETDEWEB)

    Lloret, M. T.; Ricart, V.; Muro, M. D.; Perez, D.; Martinez, I.; Brugger, S.; Romero, M. J.; Cortina, H. [hospital General Universitario La Fe. Valencia (Spain)

    2000-07-01

    To describe the radiological findings associated with ectopic ureterocele and ectopic ureter in pediatric patients. To assess the role of ultrasound (US), serial micturating cystourethrography (SM-CU) and intravenous urography (IVU) in the diagnosis of these two entities. The authors performed a retrospective study of 132 patients, 73 with ectopic ureterocele and 59 with ectopic ureter. The imaging studies used were US, SMCU, IVU and methods to determine renal function (diuretic renography and renal scintigraphy). The findings were confirmed during surgery in every case. The most common radiological findings in ectopic ureterocele were renal duplication (86,3%). vesicoureteral reflux (VUR) to the lower half of the kidney (46.6%), dilatation of the lower pole of the kidney (38.4%) and contralateral duplication (30.1%). In boys, the ectopic ureter entered via bladder neck and posterior urethra (73.7%) or into seminal vesicles (15.8%); in girls, it went to vagina (32.5%), bladder neck (30%) or urethra (22.5%). Renal duplication was associated in 64.4%, with VUR to the ectopic ureter in 21% while there was a single renal system in 35.6%, with VUR to the ectopic ureter in 57.1% and contralateral renal agenesis in 19%. Eighteen patients (13.6%) presented a single, dy plastic, nonfunctioning renal system (6 cases of ureterocele and 12 of ectopic ureter). Knowledge of the embryological development of ureteral duplication is essential for the understanding of these two entities and helps to differentiate between them, thus facilitating a sometimes complicated diagnosis. Ectopic ureters and ureteroceles accompanied by a single, dysplastic renal system are associated with a greater incidence of congenital anomalies and a higher rate of complications than the duplicate systems. A prenatal US examination enables early diagnosis. The anatomical information provided by US is, on occasion, more valuable than that resulting from IVU or SMCU, However, IVU is indispensable in girls

  17. Isolation of Synaptosomes, Synaptic Plasma Membranes, and Synaptic Junctional Complexes.

    Science.gov (United States)

    Michaelis, Mary L; Jiang, Lei; Michaelis, Elias K

    2017-01-01

    Isolation of synaptic nerve terminals or synaptosomes provides an opportunity to study the process of neurotransmission at many levels and with a variety of approaches. For example, structural features of the synaptic terminals and the organelles within them, such as synaptic vesicles and mitochondria, have been elucidated with electron microscopy. The postsynaptic membranes are joined to the presynaptic "active zone" of transmitter release through cell adhesion molecules and remain attached throughout the isolation of synaptosomes. These "post synaptic densities" or "PSDs" contain the receptors for the transmitters released from the nerve terminals and can easily be seen with electron microscopy. Biochemical and cell biological studies with synaptosomes have revealed which proteins and lipids are most actively involved in synaptic release of neurotransmitters. The functional properties of the nerve terminals, such as responses to depolarization and the uptake or release of signaling molecules, have also been characterized through the use of fluorescent dyes, tagged transmitters, and transporter substrates. In addition, isolated synaptosomes can serve as the starting material for the isolation of relatively pure synaptic plasma membranes (SPMs) that are devoid of organelles from the internal environment of the nerve terminal, such as mitochondria and synaptic vesicles. The isolated SPMs can reseal and form vesicular structures in which transport of ions such as sodium and calcium, as well as solutes such as neurotransmitters can be studied. The PSDs also remain associated with the presynaptic membranes during isolation of SPM fractions, making it possible to isolate the synaptic junctional complexes (SJCs) devoid of the rest of the plasma membranes of the nerve terminals and postsynaptic membrane components. Isolated SJCs can be used to identify the proteins that constitute this highly specialized region of neurons. In this chapter, we describe the steps involved

  18. Magnetic and sensitive magnetoelastic properties of Finemet nanostructured ribbon

    International Nuclear Information System (INIS)

    Pham Duc Thang; Hoang Hai Duong; Nguyen Hoang Nghi

    2009-01-01

    Soft-magnetic Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 (Finemet) ribbon has been fabricated by using melt-spinning techniques. After annealing at suitable temperature the ribbon changes from an amorphous to crystalline state which related to the formation of Fe nanocrystallites. Study on the magnetic and magnetoelastic properties of the ribbon is presented. Furthermore, based on the fabricated ribbon stress sensors are simply constructed. The sensors showed high sensitivity of 3.8 mV/MPa as well as a wide working range up to 17 MPa. These sensors are potential for practical applications such as detecting small stress and movement in civil structures.

  19. Nanostructure and magnetic properties of Ni-substituted finemet ribbons

    International Nuclear Information System (INIS)

    Iturriza, N.; Fernandez, L.; Ipatov, M.; Vara, G.; Pierna, A.R.; Val, J.J. del; Chizhik, A.; Gonzalez, J.

    2007-01-01

    Magnetic anisotropy has been induced during the nanocrystallization process of Ni-rich amorphous ferromagnetic (Finemet) ribbons by means of the application of a constant stress during the annealing process. Magnetization measurements have evidenced the anisotropy of the treated samples. The main goal of this work was the analysis of the treated ribbons using X-ray Diffraction (XRD), Transmission Electronic Microscopy (TEM) and Atomic Force Microscopy (AFM). AFM measurements revealed in all the cases a strong nanocrystallisation of the surface without evidences of amorphous matrix, which contrast with XRD and TEM measurements that have shown a high content of amorphous phase in the bulk of the ribbons. Magneto-optical Kerr effect measurements show much higher coercive field values than in the bulk, indicating a complex magnetic behavior for the surface of the ribbons

  20. Analysis of stress-strain relationships in silicon ribbon

    Science.gov (United States)

    Dillon, O. W., Jr.

    1984-01-01

    An analysis of stress-strain relationships in silicon ribbon is presented. A model to present entire process, dynamical Transit Analysis is developed. It is found that knowledge of past-strain history is significant in modeling activities.

  1. Development of a magnetic measurement device for thin ribbon samples

    International Nuclear Information System (INIS)

    Sato, Yuta; Todaka, Takashi; Enokizono, Masato

    2008-01-01

    This paper presents a magnetic measurement device for thin ribbon samples, which are produced by rapid cooling technique. This device enables us to measure magnetic properties easily by only inserting a ribbon sample into a sample holder. The sample holder was made by bakelite to fix any width sample. A long solenoid coil was used to generate a uniform magnetic field and the sample holder was placed at the mid part of the solenoid. The magnetic field strength was measured using a shunt resistor and the magnetic flux density and magnetization in sample ribbons were evaluated by using search coils. The accuracy of measurement was verified with an amorphous metal ribbon sample. Next, we have measured magnetic properties of some magnetic shape memory alloys, which have different compositions. The measured results are compared and we clarified the effect of Sm contents on the magnetic properties

  2. Ectopic Varices in Colonic Stoma: MDCT Findings

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Woong; Lee, Chang Hee; Kim, Kyeong Ah; Park, Cheol Min; Kim, Jin Yong [Guro Hospital of Korea University, Seoul (Korea, Republic of)

    2006-12-15

    We describe the 2D reformatted and 3D volume rendered images by MDCT in a patient with an episode of acute bleeding from the colonic stoma. This case indicates that the 2D reformatted and 3D volume rendered images are useful to detect this rare complication of portal hypertension, and they help to tailor adequate treatment for the patients with bleeding from stomal varices. Ectopic varices are an uncommon cause of gastrointestinal hemorrhage, but they account for up to 5% of all variceal bleedings (1). Bleeding from stomal varices has been reported in up to 20% of the patients suffering with chronic liver failure with permanent stoma (2). However, the diagnosis of stomal varices is difficult because bleeding from stoma may also be associated with lower gastrointestinal bleeding. To the best of our knowledge, the 2D reformatted and 3D volume rendered images by MDCT for visualization of ectopic stomal varices have not been previously reported in the medical literature.

  3. Ectopic ureterocele in the male infant

    International Nuclear Information System (INIS)

    Ekloef, O.; Loehr, G.; Ringertz, H.; Thomasson, B.

    1978-01-01

    An account is given of a series of ectopic ureterocele present in 14 male infants. The malformation is found to be more complex than in the female. The ipsilateral renal function is severely impaired or abolished and obstruction to the bladder outflow common. Associated dilatation and elongation of the posterior urethra during micturition may result in a valvelike appearance. Eversion of the male ureterocele is common and possible mechanisms to account for this event are discussed. (Auth.)

  4. Ectopic hepatocellular carcinoma in a dog.

    Science.gov (United States)

    Burton, I R; Limpus, K; Thompson, K G; Owen, M C; Worth, A J

    2005-12-01

    A 14-year-old neutered male Bearded Collie was presented with a history of recurrent, intermittent urinary incontinence of 7 years duration. A large, firm, non-painful mass was found in the mid-abdominal region on palpation. Ultrasonography of the mass revealed a compartmentalised structure with mixed echogenicity, and which did not appear to be associated with any of the abdominal organs. Ultrasound-guided fine needle aspirates contained several clusters of epithelial cells with cytological features of hepatocytes. At exploratory laparotomy, the mass was found in the gastrosplenic ligament within the greater omentum. PATHOLOGICAL FINDINGS AND DIAGNOSIS: Histopathologically, the mass consisted of sheets of hepatocytes, but without the characteristic hepatic architecture. The cells showed moderate variation in nuclear size and were sometimes binucleate. A diagnosis of hepatocellular carcinoma (HCC) in the mesentery was made. The presence of ectopic hepatic tissue has been reported rarely in man and cats, but not in the dog. Neoplastic transformation of ectopic hepatic tissue is seen in man. This is the first report of the presentation, clinical findings and treatment of a dog with ectopic HCC.

  5. CT diagnosis of abdominal ectopic pheochromocytoma

    International Nuclear Information System (INIS)

    Zhang Yuping; Zhao Zhiying

    2010-01-01

    Objective: To discuss the value of CT in diagnosis of abdominal ectopic pheochromocytoma. Methods: CT findings of 5 cases surgically and pathologically proved with ectopic pheochromocytoma were retrospectively analyzed. Results: Soft tissue mass with light asymmetry enhancement was found between the abdominal aorta and the inferior vena ca-va in one case. 1 case was completely cystic with light enhancement of the cystwall located in front of the left side of the abdominal aorta. 1 case of large solid mass occurred between the renal hilum and the tail of pancreas, with irregular shape, unclear boundary, central necrosis, calcification and obviously enhancement at the solid part. 2 cases showed as oval soft lump with even density, moderate strengthening located before the abdominal aorta. Paroxysmal hypertension occurred in 3 cases and didn't in 2 cases. Hypertension happened in 1 case during the operation because of stimulation. Blood pressure appeared in 1 case during and after operation. Blood and urinary catecholamine increased significantly in 4 cases. Conclusion: Ectopic pheochromocytoma mainly located surround the abdominal aorta with diverse CT performance. It is helpful for diagnosing when finding a lesion locates at the specified sites combined with typical clinical presentation. CT can not only depict small tumor, but also can show the relationship with surrounding structure, and it provides important information for the operation and prognosis. (authors)

  6. Zoonotic ectopic fascioliasis: review and discussion.

    Science.gov (United States)

    Rashed, Amr A; Khalil, Hazem H M; Morsy, Ayman T A

    2010-12-01

    Ectopic fascioliasis (EF) has direct and indirect effects on both humans and animals. The phenomenon of EF was individual cases in the period from 1950 up to the end of last century. From the period of 2000 up to 2006, plenty of researches were on EF in the developed and undeveloped countries. Nineteen EF cases infected with the immature and few with the mature worms were 13 females and 6 males. Three cases of lymphatic, pleural and breast fascioliasis reached the adults and laid their eggs in a lymph node in the cervical region pleural cavity and breast tissues. Until recent, knowledge about the ectopic fascioliasis pathway is little. Fasciola hepatica was the commonest species in most cases. The effect of fascioliasis might be direct to liver as ectopic foci or indirect on other organs due to the metabolites and secretory excretory products. All ages and both sexes were EF infected. Watercress topped the list of water plants born encysted metacercariae followed by lettuce, mint, and alfalfa. Nearly 24 million Egyptians at risk and about 800,000 were infected. On the global scale, about 180 million are at risk of infection.

  7. Secreted factors as synaptic organizers.

    Science.gov (United States)

    Johnson-Venkatesh, Erin M; Umemori, Hisashi

    2010-07-01

    A critical step in synaptic development is the differentiation of presynaptic and postsynaptic compartments. This complex process is regulated by a variety of secreted factors that serve as synaptic organizers. Specifically, fibroblast growth factors, Wnts, neurotrophic factors and various other intercellular signaling molecules are proposed to regulate presynaptic and/or postsynaptic differentiation. Many of these factors appear to function at both the neuromuscular junction and in the central nervous system, although the specific function of the molecules differs between the two. Here we review secreted molecules that organize the synaptic compartments and discuss how these molecules shape synaptic development, focusing on mammalian in vivo systems. Their critical role in shaping a functional neural circuit is underscored by their possible link to a wide range of neurological and psychiatric disorders both in animal models and by mutations identified in human patients. © The Authors (2010). Journal Compilation © Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  8. Presynaptic dystroglycan-pikachurin complex regulates the proper synaptic connection between retinal photoreceptor and bipolar cells.

    Science.gov (United States)

    Omori, Yoshihiro; Araki, Fumiyuki; Chaya, Taro; Kajimura, Naoko; Irie, Shoichi; Terada, Koji; Muranishi, Yuki; Tsujii, Toshinori; Ueno, Shinji; Koyasu, Toshiyuki; Tamaki, Yasuhiro; Kondo, Mineo; Amano, Shiro; Furukawa, Takahisa

    2012-05-02

    Dystroglycan (DG) is a key component of the dystrophin-glycoprotein complex (DGC) at the neuromuscular junction postsynapse. In the mouse retina, the DGC is localized at the presynapse of photoreceptor cells, however, the function of presynaptic DGC is poorly understood. Here, we developed and analyzed retinal photoreceptor-specific DG conditional knock-out (DG CKO) mice. We found that the DG CKO retina showed a reduced amplitude and a prolonged implicit time of the ERG b-wave. Electron microscopic analysis revealed that bipolar dendrite invagination into the photoreceptor terminus is perturbed in the DG CKO retina. In the DG CKO retina, pikachurin, a DG ligand in the retina, is markedly decreased at photoreceptor synapses. Interestingly, in the Pikachurin(-/-) retina, the DG signal at the ribbon synaptic terminus was severely reduced, suggesting that pikachurin is required for the presynaptic accumulation of DG at the photoreceptor synaptic terminus, and conversely DG is required for pikachurin accumulation. Furthermore, we found that overexpression of pikachurin induces formation and clustering of a DG-pikachurin complex on the cell surface. The Laminin G repeats of pikachurin, which are critical for its oligomerization and interaction with DG, were essential for the clustering of the DG-pikachurin complex as well. These results suggest that oligomerization of pikachurin and its interaction with DG causes DG assembly on the synapse surface of the photoreceptor synaptic terminals. Our results reveal that the presynaptic interaction of pikachurin with DG at photoreceptor terminals is essential for both the formation of proper photoreceptor ribbon synaptic structures and normal retinal electrophysiology.

  9. Regulation of synaptic structure by ubiquitin C-terminal hydrolase L1.

    Science.gov (United States)

    Cartier, Anna E; Djakovic, Stevan N; Salehi, Afshin; Wilson, Scott M; Masliah, Eliezer; Patrick, Gentry N

    2009-06-17

    Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a deubiquitinating enzyme that is selectively and abundantly expressed in the brain, and its activity is required for normal synaptic function. Here, we show that UCH-L1 functions in maintaining normal synaptic structure in hippocampal neurons. We found that UCH-L1 activity is rapidly upregulated by NMDA receptor activation, which leads to an increase in the levels of free monomeric ubiquitin. Conversely, pharmacological inhibition of UCH-L1 significantly reduces monomeric ubiquitin levels and causes dramatic alterations in synaptic protein distribution and spine morphology. Inhibition of UCH-L1 activity increases spine size while decreasing spine density. Furthermore, there is a concomitant increase in the size of presynaptic and postsynaptic protein clusters. Interestingly, however, ectopic expression of ubiquitin restores normal synaptic structure in UCH-L1-inhibited neurons. These findings point to a significant role of UCH-L1 in synaptic remodeling, most likely by modulating free monomeric ubiquitin levels in an activity-dependent manner.

  10. Regulation of Synaptic Structure by the Ubiquitin C-terminal Hydrolase UCH-L1

    Science.gov (United States)

    Cartier, Anna E.; Djakovic, Stevan N.; Salehi, Afshin; Wilson, Scott M.; Masliah, Eliezer; Patrick, Gentry N.

    2009-01-01

    UCH-L1 is a de-ubiquitinating enzyme that is selectively and abundantly expressed in the brain, and its activity is required for normal synaptic function. Here, we show that UCH-L1 functions in maintaining normal synaptic structure in hippocampal neurons. We have found that UCH-L1 activity is rapidly up-regulated by NMDA receptor activation which leads to an increase in the levels of free monomeric ubiquitin. Conversely, pharmacological inhibition of UCH-L1 significantly reduces monomeric ubiquitin levels and causes dramatic alterations in synaptic protein distribution and spine morphology. Inhibition of UCH-L1 activity increases spine size while decreasing spine density. Furthermore, there is a concomitant increase in the size of pre and postsynaptic protein clusters. Interestingly, however, ectopic expression of ubiquitin restores normal synaptic structure in UCH-L1 inhibited neurons. These findings point to a significant role of UCH-L1 in synaptic remodeling most likely by modulating free monomeric ubiquitin levels in an activity-dependent manner. PMID:19535597

  11. Flare Ribbons Approach Observed by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ting; Zhang, Jun; Hou, Yijun, E-mail: liting@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2017-10-10

    We report flare ribbons approach (FRA) during a multiple-ribbon M-class flare on 2015 November 4 in NOAA AR 12443, obtained by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory. The flare consisted of a pair of main ribbons and two pairs of secondary ribbons. The two pairs of secondary ribbons were formed later than the appearance of the main ribbons, with respective time delays of 15 and 19 minutes. The negative-polarity main ribbon spread outward faster than the first secondary ribbon with the same polarity in front of it, and thus the FRA was generated. Just before their encounter, the main ribbon was darkening drastically and its intensity decreased by about 70% in 2 minutes, implying the suppression of main-phase reconnection that produced two main ribbons. The FRA caused the deflection of the main ribbon to the direction of secondary ribbon with a deflection angle of about 60°. A post-approach arcade was formed about 2 minutes later and the downflows were detected along the new arcade with velocities of 35–40 km s{sup −1}, indicative of the magnetic restructuring during the process of FRA. We suggest that there are three topological domains with footpoints outlined by the three pairs of ribbons. Close proximity of these domains leads to deflection of the ribbons, which is in agreement with the magnetic field topology.

  12. Synaptic consolidation across multiple timescales

    Directory of Open Access Journals (Sweden)

    Lorric Ziegler

    2014-03-01

    Full Text Available The brain is bombarded with a continuous stream of sensory events, but retains only a small subset in memory. The selectivity of memory formation prevents our memory from being overloaded with irrelevant items that would rapidly bring the brain to its storage limit; moreover, selectivity also prevents overwriting previously formed memories with new ones. Memory formation in the hippocampus, as well as in other brain regions, is thought to be linked to changes in the synaptic connections between neurons. In this view, sensory events imprint traces at the level of synapses that reflect potential memory items. The question of memory selectivity can therefore be reformulated as follows: what are the reasons and conditions that some synaptic traces fade away whereas others are consolidated and persist? Experimentally, changes in synaptic strength induced by 'Hebbian' protocols fade away over a few hours (early long-term potentiation or e-LTP, unless these changes are consolidated. The experiments and conceptual theory of synaptic tagging and capture (STC provide a mechanistic explanation for the processes involved in consolidation. This theory suggests that the initial trace of synaptic plasticity sets a tag at the synapse, which then serves as a marker for potential consolidation of the changes in synaptic efficacy. The actual consolidation processes, transforming e-LTP into late LTP (l-LTP, require the capture of plasticity-related proteins (PRP. We translate the above conceptual model into a compact computational model that accounts for a wealth of in vitro data including experiments on cross-tagging, tag-resetting and depotentiation. A central ingredient is that synaptic traces are described with several variables that evolve on different time scales. Consolidation requires the transmission of information from a 'fast' synaptic trace to a 'slow' one through a 'write' process, including the formation of tags and the production of PRP for the

  13. Role for a Novel Usher Protein Complex in Hair Cell Synaptic Maturation

    Science.gov (United States)

    Zallocchi, Marisa; Meehan, Daniel T.; Delimont, Duane; Rutledge, Joseph; Gratton, Michael Anne; Flannery, John; Cosgrove, Dominic

    2012-01-01

    The molecular mechanisms underlying hair cell synaptic maturation are not well understood. Cadherin-23 (CDH23), protocadherin-15 (PCDH15) and the very large G-protein coupled receptor 1 (VLGR1) have been implicated in the development of cochlear hair cell stereocilia, while clarin-1 has been suggested to also play a role in synaptogenesis. Mutations in CDH23, PCDH15, VLGR1 and clarin-1 cause Usher syndrome, characterized by congenital deafness, vestibular dysfunction and retinitis pigmentosa. Here we show developmental expression of these Usher proteins in afferent spiral ganglion neurons and hair cell synapses. We identify a novel synaptic Usher complex comprised of clarin-1 and specific isoforms of CDH23, PCDH15 and VLGR1. To establish the in vivo relevance of this complex, we performed morphological and quantitative analysis of the neuronal fibers and their synapses in the Clrn1−/− mouse, which was generated by incomplete deletion of the gene. These mice showed a delay in neuronal/synaptic maturation by both immunostaining and electron microscopy. Analysis of the ribbon synapses in Ames waltzerav3J mice also suggests a delay in hair cell synaptogenesis. Collectively, these results show that, in addition to the well documented role for Usher proteins in stereocilia development, Usher protein complexes comprised of specific protein isoforms likely function in synaptic maturation as well. PMID:22363448

  14. Role for a novel Usher protein complex in hair cell synaptic maturation.

    Directory of Open Access Journals (Sweden)

    Marisa Zallocchi

    Full Text Available The molecular mechanisms underlying hair cell synaptic maturation are not well understood. Cadherin-23 (CDH23, protocadherin-15 (PCDH15 and the very large G-protein coupled receptor 1 (VLGR1 have been implicated in the development of cochlear hair cell stereocilia, while clarin-1 has been suggested to also play a role in synaptogenesis. Mutations in CDH23, PCDH15, VLGR1 and clarin-1 cause Usher syndrome, characterized by congenital deafness, vestibular dysfunction and retinitis pigmentosa. Here we show developmental expression of these Usher proteins in afferent spiral ganglion neurons and hair cell synapses. We identify a novel synaptic Usher complex comprised of clarin-1 and specific isoforms of CDH23, PCDH15 and VLGR1. To establish the in vivo relevance of this complex, we performed morphological and quantitative analysis of the neuronal fibers and their synapses in the Clrn1-/- mouse, which was generated by incomplete deletion of the gene. These mice showed a delay in neuronal/synaptic maturation by both immunostaining and electron microscopy. Analysis of the ribbon synapses in Ames waltzer(av3J mice also suggests a delay in hair cell synaptogenesis. Collectively, these results show that, in addition to the well documented role for Usher proteins in stereocilia development, Usher protein complexes comprised of specific protein isoforms likely function in synaptic maturation as well.

  15. Dual ectopic thyroid: A case report with review of literature

    International Nuclear Information System (INIS)

    Sood, A.; Seam, R. K.; Gupta, M.; Raj Sharma, D.; Bhardwaj, P.

    2011-01-01

    The ectopic thyroid gland is a rare entity which is mostly found along the line of descent of the thyroid gland. Most of the patients present with midline swelling and usually seek medical attention. Dual ectopic thyroid gland is even rarer. The clinical examination and different imaging modalities establish its diagnosis. Radionuclide studies are highly sensitive and specific in demonstrating the functional tissues in patients with ectopic thyroid, thereby guiding further management. The authors reported a case of ectopic thyroid gland in a girl with midline neck swelling initially, subsequently lost to follow-up. She again presented with enlarged swelling after a period of three years with dual ectopic thyroid in the neck region on thyroid scan. Thyroid scintigraphy demonstrated that progression in the size of ectopic glands was due to neglect in treatment.

  16. Clinicopathological Features and Treatment of Ectopic Varices with Portal Hypertension

    Directory of Open Access Journals (Sweden)

    Takahiro Sato

    2011-01-01

    Full Text Available Bleeding from ectopic varices, which is rare in patients with portal hypertension, is generally massive and life-threatening. Forty-three patients were hospitalized in our ward for gastrointestinal bleeding from ectopic varices. The frequency of ectopic varices was 43/1218 (3.5% among portal hypertensive patients in our ward. The locations of the ectopic varices were rectal in thirty-two, duodenal in three, intestinal in two, vesical in three, stomal in one, and colonic in two patients. Endoscopic or interventional radiologic treatment was performed successfully for ectopic varices. Hemorrhage from ectopic varices should be kept in mind in patients with portal hypertension presenting with lower gastrointestinal bleeding.

  17. Ectopic recurrence of craniopharyngioma: Reporting three new cases.

    Science.gov (United States)

    Yang, Yang; Shrestha, David; Shi, Xiang-En; Zhou, Zhongqing; Qi, Xueling; Qian, Hai

    2015-04-01

    Ectopic recurrence of craniopharyngioma is extremely rare following transcranial procedures of primary tumour. Here we describe 3 new cases of ectopic recurrence along the surgical route after transcranial gross total resection of primary tumour. All 3 cases are male adults--2 of them had papillary-type tumour with the other being adamantinomatous. All ectopic tumours were safely resected via repeated craniotomy. Long-term surveillance of patients with resected craniopharyngioma is essential.

  18. Ectopic Neurohypophysis in Patient with Pituitary Dwarfism: A Case Report

    OpenAIRE

    İlhan Kılınç; Deniz Gökalp; Cihan Akgül Özmen

    2008-01-01

    Ectopic neurohypophysis is an anomaly of the Pituitary gland whichmay be associated with short stature due to Growth hormone deficiency.MRI is the modality of choice in diagnosing this condition. We present acase of pituitary dwarfism and ectopic neurohypophysis with clinical andradiological findings. 21 year-old male admitted with short stature. Allhormones, except prolactin, of anterior hypophysis were low. Bright spotwas ectopically located at level of median eminence on enhanced MRI ofhyp...

  19. Biomarkers for Ectopic Pregnancy and Pregnancy of Unknown Location

    OpenAIRE

    Senapati, Suneeta; Barnhart, Kurt T.

    2013-01-01

    Early pregnancy failure is the most common complication of pregnancy, and 1–2% of all pregnancies will be ectopic. As one of the leading causes of maternal morbidity and mortality, diagnosing ectopic pregnancy and determining the fate of a pregnancy of unknown location are of great clinical concern. Several serum and plasma biomarkers for ectopic pregnancy have been investigated independently and in combination. The following is a review of the state of biomarker discovery and development for...

  20. Widespread ectopic expression of olfactory receptor genes

    Directory of Open Access Journals (Sweden)

    Yanai Itai

    2006-05-01

    Full Text Available Abstract Background Olfactory receptors (ORs are the largest gene family in the human genome. Although they are expected to be expressed specifically in olfactory tissues, some ectopic expression has been reported, with special emphasis on sperm and testis. The present study systematically explores the expression patterns of OR genes in a large number of tissues and assesses the potential functional implication of such ectopic expression. Results We analyzed the expression of hundreds of human and mouse OR transcripts, via EST and microarray data, in several dozens of human and mouse tissues. Different tissues had specific, relatively small OR gene subsets which had particularly high expression levels. In testis, average expression was not particularly high, and very few highly expressed genes were found, none corresponding to ORs previously implicated in sperm chemotaxis. Higher expression levels were more common for genes with a non-OR genomic neighbor. Importantly, no correlation in expression levels was detected for human-mouse orthologous pairs. Also, no significant difference in expression levels was seen between intact and pseudogenized ORs, except for the pseudogenes of subfamily 7E which has undergone a human-specific expansion. Conclusion The OR superfamily as a whole, show widespread, locus-dependent and heterogeneous expression, in agreement with a neutral or near neutral evolutionary model for transcription control. These results cannot reject the possibility that small OR subsets might play functional roles in different tissues, however considerable care should be exerted when offering a functional interpretation for ectopic OR expression based only on transcription information.

  1. Treatment of Ectopic Mandibular Second Permanent Molar with Elastic Separators

    Directory of Open Access Journals (Sweden)

    R. Rajesh

    2014-01-01

    Full Text Available Ectopic eruption is a developmental disturbance in which the tooth fails to follow its normal eruption pathway. Ectopic eruption of the second molar is relatively rare. This paper presents the case of thirteen-year-old male with an ectopic mandibular second permanent molar. The condition was corrected with surgical exposure and placement of elastic separators. This case report lays emphasis on the practice of basic methods to obtain acceptable results rather than extensive surgical or orthodontic corrections. It is advised that ectopic teeth should not be neglected especially when it concerns developing caries and malocclusion.

  2. Endotracheal ectopic parathyroid adenoma mimicking asthma

    Directory of Open Access Journals (Sweden)

    M. Akif Özgül

    2014-01-01

    Full Text Available Primary benign tumors of the trachea are uncommon. These tumors may cause tracheal occlusion and lead to a misdiagnosis of asthma. Ectopic parathyroid adenoma (EPA can be seen anywhere between the mandibular angle and the mediastinum. The distal part of the trachea is a rare location for EPA, and EPA obstructing the endotracheal lumen has not been reported in the literature. We herein describe a 52-year-old female with a several-year history of asthma treatment who presented with progressive dyspnea. Computed tomography revealed a mass that was obstructing the tracheal lumen. Total mass excision was performed via endobronchial treatment, and pathologic examination revealed EPA.

  3. Wrinkles, loops, and topological defects in twisted ribbons

    Science.gov (United States)

    Chopin, Julien

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

  4. Synaptic Effects of Electric Fields

    Science.gov (United States)

    Rahman, Asif

    Learning and sensory processing in the brain relies on the effective transmission of information across synapses. The strength and efficacy of synaptic transmission is modifiable through training and can be modulated with noninvasive electrical brain stimulation. Transcranial electrical stimulation (TES), specifically, induces weak intensity and spatially diffuse electric fields in the brain. Despite being weak, electric fields modulate spiking probability and the efficacy of synaptic transmission. These effects critically depend on the direction of the electric field relative to the orientation of the neuron and on the level of endogenous synaptic activity. TES has been used to modulate a wide range of neuropsychiatric indications, for various rehabilitation applications, and cognitive performance in diverse tasks. How can a weak and diffuse electric field, which simultaneously polarizes neurons across the brain, have precise changes in brain function? Designing therapies to maximize desired outcomes and minimize undesired effects presents a challenging problem. A series of experiments and computational models are used to define the anatomical and functional factors leading to specificity of TES. Anatomical specificity derives from guiding current to targeted brain structures and taking advantage of the direction-sensitivity of neurons with respect to the electric field. Functional specificity originates from preferential modulation of neuronal networks that are already active. Diffuse electric fields may recruit connected brain networks involved in a training task and promote plasticity along active synaptic pathways. In vitro, electric fields boost endogenous synaptic plasticity and raise the ceiling for synaptic learning with repeated stimulation sessions. Synapses undergoing strong plasticity are preferentially modulated over weak synapses. Therefore, active circuits that are involved in a task could be more susceptible to stimulation than inactive circuits

  5. Ruptured ectopic pregnancy diagnosed with computed tomography

    International Nuclear Information System (INIS)

    Michalak, Maciej; Żurada, Anna; Biernacki, Maciej; Zygmunt, Kozielec

    2010-01-01

    The rupture of ectopic pregnancy (EP) still remains the primary and direct cause of death in the first trimester of pregnancy. Ultrasonography is known to be a modality of choice in EP diagnostics. We found a severe discrepancy between the frequency of ectopic pregnancies (EP) and the number of available computed tomography (CT) examinations. A 29-year-old woman was admitted to the emergency department with a history of abdominal pain, nausea, vomiting and collapse. Sonographic findings of a suspected EP were unclear. Moreover, not all features of intrauterine pregnancy were present. Due to the patient’s life-threatening condition, an emergency multi-slice CT with MPR and VRT reconstructions was performed, revealing symptoms of a ruptured EP. In the right adnexal area, a well-vascularized, solid-cystic abnormal mass lesion was found. Intraperitoneal hemorrhage was confirmed intraoperatively, and the right fallopian tube with a tubal EP was resected. In the surgery in situ, as well as in the pathological examination of the tumor mass, a human embryo of approximately 1.5 cm in length (beginning of the 8 th week of gestation) was found. Although ultrasonography still remains the first-line imaging examination in EP diagnostics, sometimes the findings of suspected EPs are unclear and not sufficient. The rupture of EP, with serious bleeding and symptoms of shock, may require an emergent pelvic and abdominal CT inspection. A clear correlation was found between the macroscopic CT images and the intraoperatively sampled material

  6. A MAGNETIC RIBBON MODEL FOR STAR-FORMING FILAMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Auddy, Sayantan; Basu, Shantanu [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada); Kudoh, Takahiro, E-mail: sauddy3@uwo.ca, E-mail: basu@uwo.ca, E-mail: kudoh@nagasaki-u.ac.jp [Faculty of Education, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan)

    2016-11-01

    We develop a magnetic ribbon model for molecular cloud filaments. These result from turbulent compression in a molecular cloud in which the background magnetic field sets a preferred direction. We argue that this is a natural model for filaments and is based on the interplay between turbulence, strong magnetic fields, and gravitationally driven ambipolar diffusion, rather than pure gravity and thermal pressure. An analytic model for the formation of magnetic ribbons that is based on numerical simulations is used to derive a lateral width of a magnetic ribbon. This differs from the thickness along the magnetic field direction, which is essentially the Jeans scale. We use our model to calculate a synthetic observed relation between apparent width in projection versus observed column density. The relationship is relatively flat, similar to observations, and unlike the simple expectation based on a Jeans length argument.

  7. Piezoelectric ribbons printed onto rubber for flexible energy conversion.

    Science.gov (United States)

    Qi, Yi; Jafferis, Noah T; Lyons, Kenneth; Lee, Christine M; Ahmad, Habib; McAlpine, Michael C

    2010-02-10

    The development of a method for integrating highly efficient energy conversion materials onto stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting systems. Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. Here, we overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas. Fundamental characterization of the ribbons by piezo-force microscopy indicates that their electromechanical energy conversion metrics are among the highest reported on a flexible medium. The excellent performance of the piezo-ribbon assemblies coupled with stretchable, biocompatible rubber may enable a host of exciting avenues in fundamental research and novel applications.

  8. Inter-ribbon tunneling in graphene: An atomistic Bardeen approach

    Energy Technology Data Exchange (ETDEWEB)

    Van de Put, Maarten L., E-mail: maarten.vandeput@uantwerpen.be; Magnus, Wim [Department of Physics, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); imec, B-3001 Heverlee (Belgium); Vandenberghe, William G.; Fischetti, Massimo V. [Department of Material Science, University of Texas at Dallas, Texas 75080 (United States); Sorée, Bart [Department of Physics, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); imec, B-3001 Heverlee (Belgium); Department of Electrical Engineering, KU Leuven, B-3001 Leuven (Belgium)

    2016-06-07

    A weakly coupled system of two crossed graphene nanoribbons exhibits direct tunneling due to the overlap of the wavefunctions of both ribbons. We apply the Bardeen transfer Hamiltonian formalism, using atomistic band structure calculations to account for the effect of the atomic structure on the tunneling process. The strong quantum-size confinement of the nanoribbons is mirrored by the one-dimensional character of the electronic structure, resulting in properties that differ significantly from the case of inter-layer tunneling, where tunneling occurs between bulk two-dimensional graphene sheets. The current-voltage characteristics of the inter-ribbon tunneling structures exhibit resonance, as well as stepwise increases in current. Both features are caused by the energetic alignment of one-dimensional peaks in the density-of-states of the ribbons. Resonant tunneling occurs if the sign of the curvature of the coupled energy bands is equal, whereas a step-like increase in the current occurs if the signs are opposite. Changing the doping modulates the onset-voltage of the effects as well as their magnitude. Doping through electrostatic gating makes these structures promising for application towards steep slope switching devices. Using the atomistic empirical pseudopotentials based Bardeen transfer Hamiltonian method, inter-ribbon tunneling can be studied for the whole range of two-dimensional materials, such as transition metal dichalcogenides. The effects of resonance and of step-like increases in the current we observe in graphene ribbons are also expected in ribbons made from these alternative two-dimensional materials, because these effects are manifestations of the one-dimensional character of the density-of-states.

  9. The Clinical and Ultrasonic Study of Clinically Suspected Ectopic Pregnancy: Laying Emphasis on 15 proven Ectopic Pregnancies

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Myung Ho; Chung, Yung Sun [Chonnam National University College of Medicine, Gwangju (Korea, Republic of)

    2010-05-15

    Ectopic preganacies are unsuccessful pregnancies that result from implantation of fertilized ovum occurring in an aberrant area. Aside from an emergency case, the early diagnosis of ectopic pregnancy is very difficult particularly in a case with insidious onset and mild clinical manifestations. Early diagnosis not only reduces the danger, but also simplifies the management of ectopic pregnancy. Ultrasonography has been an indispensable diagnostic tool in Obstetrics and Gynecology. In the authors' experience, clinical suspected ectopic pregnancy was one of the common indications for performing ultrasonography. Since Kobayashi at al. reported the appearances of ectopic pregnancy utilizing bistable B-scan ultrasonography, the ultrasonic findings of ectopic pregnancy have been reported by many authors. But, its accuracy and reliability in the diagnosis of ectopic pregnancy are still open to controversy. The authors studied 65 cases of clinically suspected ectopic pregnancy with Picker 80 L gray scale ultrasonography from Aug. 1982 to June. 1983. There were 29 confirmed cases, of which 15 were proved to have ectopic pregnancy and 14 were proved to have diseases other than ectopic pregnancy by surgical and histopathological study or by laparoscopy and follow up study. 29 confirmed cases were reviewed. The results were as follows: 1. Among 15 ectopic pregnancies, there were 12 ampullary pregnancies, 2 isthmic pregnancies and 1 interstitial pregnancy. Among 14 cases of no ectopic pregnancy, there were 5 intrauterine pregnancies, 3 myoma uteri, 2 P.I.D., and 1 case of dermoid cyst, cystic teratoma, H-mole and tubal hematoma due to previous tuball ligation, respectively. 2. The age distribution of ectopic pregnancy was from 22 to 41 years. The common clinical manifestations of ectopic pregnancy were lower abdominal pain (73.3%), vaginal spotting or bleeding (73.3%) and amenorrhea (66.7%). 3. Positive result of urine immunologic pregnancy test was 28.6% in ectopic

  10. The Clinical and Ultrasonic Study of Clinically Suspected Ectopic Pregnancy: Laying Emphasis on 15 proven Ectopic Pregnancies

    International Nuclear Information System (INIS)

    Byun, Myung Ho; Chung, Yung Sun

    2010-01-01

    Ectopic preganacies are unsuccessful pregnancies that result from implantation of fertilized ovum occurring in an aberrant area. Aside from an emergency case, the early diagnosis of ectopic pregnancy is very difficult particularly in a case with insidious onset and mild clinical manifestations. Early diagnosis not only reduces the danger, but also simplifies the management of ectopic pregnancy. Ultrasonography has been an indispensable diagnostic tool in Obstetrics and Gynecology. In the authors' experience, clinical suspected ectopic pregnancy was one of the common indications for performing ultrasonography. Since Kobayashi at al. reported the appearances of ectopic pregnancy utilizing bistable B-scan ultrasonography, the ultrasonic findings of ectopic pregnancy have been reported by many authors. But, its accuracy and reliability in the diagnosis of ectopic pregnancy are still open to controversy. The authors studied 65 cases of clinically suspected ectopic pregnancy with Picker 80 L gray scale ultrasonography from Aug. 1982 to June. 1983. There were 29 confirmed cases, of which 15 were proved to have ectopic pregnancy and 14 were proved to have diseases other than ectopic pregnancy by surgical and histopathological study or by laparoscopy and follow up study. 29 confirmed cases were reviewed. The results were as follows: 1. Among 15 ectopic pregnancies, there were 12 ampullary pregnancies, 2 isthmic pregnancies and 1 interstitial pregnancy. Among 14 cases of no ectopic pregnancy, there were 5 intrauterine pregnancies, 3 myoma uteri, 2 P.I.D., and 1 case of dermoid cyst, cystic teratoma, H-mole and tubal hematoma due to previous tuball ligation, respectively. 2. The age distribution of ectopic pregnancy was from 22 to 41 years. The common clinical manifestations of ectopic pregnancy were lower abdominal pain (73.3%), vaginal spotting or bleeding (73.3%) and amenorrhea (66.7%). 3. Positive result of urine immunologic pregnancy test was 28.6% in ectopic pregnancy

  11. Temperature distribution study in flash-annealed amorphous ribbons

    International Nuclear Information System (INIS)

    Moron, C.; Garcia, A.; Carracedo, M.T.

    2003-01-01

    Negative magnetrostrictive amorphous ribbons have been locally current annealed with currents from 1 to 8 A and annealing times from 14 ms to 200 s. In order to obtain information about the sample temperature during flash or current annealing, a study of the temperature dispersion during annealing in amorphous ribbons was made. The local temperature variation was obtained by measuring the local intensity of the infrared emission of the sample with a CCD liquid nitrogen cooled camera. A distribution of local temperature has been found in spite of the small dimension of the sample

  12. Variation of boron concentration in metallic glass ribbons

    International Nuclear Information System (INIS)

    Nagy, A.Z.; Vasvari, B.; Bakos, L.; Duwez, P.; Bogancs, J.; Nazarov, V.M.

    1980-01-01

    The boron concentration of Fe 40 Ni 40 P 14 B 6 , Fe 32 Ni 36 Cr 14 P 12 B 6 and Fe 40 Ni 40 B 20 metallic glasses is measured by neutron activation analysis on both surfaces of the ribbon samples. It is found that the boron concentration is always higher on the bright side of the ribbon than that on the dull side which is in contact with the cold surface of the wheel during the rapid quenching from the melt. A possible explanation is given in terms of the solid-liquid interface moving rapidly from the cooled surface to the free surface when preparing the samples. (author)

  13. Hydrostatic extrusion of Cu-Ag melt spun ribbon

    Science.gov (United States)

    Hill, Mary Ann; Bingert, John F.; Bingert, Sherri A.; Thoma, Dan J.

    1998-01-01

    The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process.

  14. Ectopic pancreas causing partial gastric outlet obstruction: a case ...

    African Journals Online (AJOL)

    Ectopic pancreas causing partial gastric outlet obstruction: a case report and review of literature. ... Nigerian Journal of Surgery ... Gastric outlet obstruction resulting from ectopic pancreas in an adult is the first of its kind in our center; we, therefore, present this case to describe the challenges faced with diagnosis, treatment, ...

  15. Non-invasive diagnosis and management of ectopic pregnancy

    NARCIS (Netherlands)

    van Mello, N.M.

    2013-01-01

    The work presented in this thesis begins with a focus on non-invasive diagnostic methods for ectopic pregnancy. The heterogeneity found in studies on diagnostic tests for ectopic pregnancy has led to an international recommendation on uniform definitions of early pregnancy complications. Hereafter,

  16. Retrospective review of the medical management of ectopic ...

    African Journals Online (AJOL)

    condition is ranked among the top direct obstetric causes ... In Europe and North America, the incidence of ectopic pregnan- ... The reason for tubal implantation in an ectopic pregnancy is ... from assisted reproductive technologies, a pregnancy with current use of an intrauterine contraceptive device, and cigarette smoking.

  17. Ultrasonographic findings in 14 dogs with ectopic ureter

    International Nuclear Information System (INIS)

    Lamb, C.R.; Gregory, S.P.

    1998-01-01

    To evaluate ultrasonography as an alternative to contrast radiographyfor diagnosis of ectopic ureter in dogs, ultrasonography of the urinary tract was performed prospectively in a series of urinary incontinent dogs anesthetized for contrast radiography, Fourteen dogs had ectopic ureter based ore surgical, necropsy or unequivocal contrast radiographic findings, There were eight females and six males of a variety of breeds; five were Labrador retrievers, Mean (range) age at the time ofdiagnosis was 1.2 (0.2-4) years for females and 3.5 (0.3-5) for males(p < 0.05). Ectopic ureters were unilateral in five dogs (2 left; 3 right) find bilateral in nine dogs. Both ultrasound images and contrastradiographs were positive for 21 (91%) ectopic ureters; the same two ectopic ureters were not defected using either modality, The termination of each of the five normal ureters was visible on ultrasound images; two (40%) were visible on radiographs, Other ultrasonographic findings included dilatation of the ectopic ureter and/or ipsilateral renal pelvis ill ten (43%) instances, evidence of pyelonephritis in two dogs(with enlargement of the contralateral kidney in one dog), and urethral diverticuli in one dog, Ultrasonography is a practical diagnostic Best for ectopic ureter in clogs. In this series these was close correlation between the ultrasonographic and contrast radiographic findings for each ectopic meter, but ultrasonography enabled more accurate determination of normal ureteral anatomy

  18. Inferior ectopic pupil and typical ocular coloboma in RCS rats.

    Science.gov (United States)

    Tsuji, Naho; Ozaki, Kiyokazu; Narama, Isao; Matsuura, Tetsuro

    2011-08-01

    Ocular coloboma is sometimes accompanied by corectopia in humans and therefore ectopic pupil may indicate ocular coloboma in experimental animals. The RCS strain of rats has a low incidence of microphthalmia. We found that inferior ectopic pupil is associated exclusively with small-sized eyes in this strain. The objective of the current study was to evaluate whether inferior ectopic pupil is associated with iridal coloboma and other types of ocular coloboma in RCS rats. Both eyes of RCS rats were examined clinically, and those with inferior ectopic pupils underwent morphologic and morphometric examinations. In a prenatal study, coronal serial sections of eyeballs from fetuses at gestational day 16.5 were examined by using light microscopy. Ectopic pupils in RCS rats were found exclusively in an inferior position, where the iris was shortened. Fundic examination revealed severe chorioretinal coloboma in all cases of inferior ectopic pupil. The morphologic characteristics closely resembled those of chorioretinal coloboma in humans. Histopathologic examination of primordia showed incomplete closure of the optic fissure in 4 eyeballs of RCS fetuses. Neither F(1) rats nor N(2) (progeny of RCS × BN matings) displayed any ocular anomalies, including ectopic pupils. The RCS strain is a suitable model for human ocular coloboma, and inferior ectopic pupil appears to be a strong indicator of ocular coloboma.

  19. Ectopic Pregnancy in Lagos State University Teaching Hospital ...

    African Journals Online (AJOL)

    We set out to determine the socio-demographic factors,pattern of presentation and management of ectopic pregnancy in a University Teaching Hospital in Lagos, Nigeria. A retrospective descriptive analysis of all cases of ectopic pregnancy over a 2-year period was carried out. The case notes were retrieved from the ...

  20. Ectopic pregnancy experience in a tertiary health facility in South ...

    African Journals Online (AJOL)

    Background: Ectopic pregnancy is a life-threatening gynecological emergency, and a significant cause of maternal morbidity and mortality in Nigeria. Objective: To determine the incidence, clinical presentation, risk factors and management outcomes of ectopic pregnancies in a tertiary health facility. Methods: A retrospective ...

  1. Risk factors and outcomes of ectopic pregnancies at Aminu Kano ...

    African Journals Online (AJOL)

    Objectives: To determine the incidence, risk factors, clinical presentation, morbidity and mortality of ectopic pregnancies at Aminu Kano Teaching Hospital. Methods: It is a retrospective study of patients with ectopic pregnancies treated at Aminu Kano Teaching Hospital (AKTH), Nigeria, from 1st January, 2005 to 31st ...

  2. Association of anti-Chlamydia antibodies with ectopic pregnancy in ...

    African Journals Online (AJOL)

    Background: Ectopic pregnancy remains a major public health problem especially in many developing countries where it is a significant contributor to pregnancy related morbidity and mortality. Objective: To determine the association between prior Chlamydia trachomatis infection and the risk of ectopic pregnancy. Methods: ...

  3. Impact of ectopic pregnancy for reproductive prognosis in next generation

    DEFF Research Database (Denmark)

    Kårhus, Line Lund; Egerup, Pia; Skovlund, Charlotte Wessel

    2014-01-01

    The impact of an ectopic pregnancy in the next generation is unknown. Our aim was to compare reproductive outcomes in daughters of women with and without ectopic pregnancy. Designed as a historical prospective controlled cohort study with data collected in four Danish registries from 1977-2009, w...

  4. Anterior abdominal wall ectopic testes: A report of two cases ...

    African Journals Online (AJOL)

    Undescended testis (UDT) is a common anomaly of the male reproductive system affecting about 2% to 4% of male infants more commonly preterms. If the testis remains in the line of normal descent, it is classified as an UDT. If it is not in the line of normal descent, it is termed an ectopic testis. Common sites of ectopic testes ...

  5. Ectopic Pancreas Causing Partial Gastric Outlet Obstruction: A Case ...

    African Journals Online (AJOL)

    Ectopic pancreas is a rare cause of gastric outlet obstruction, perhaps rarer still among Africans. Although the entity is known, the diagnostic challenges are enormous, especially in the poor‑resource environment. Gastric outlet obstruction resulting from ectopic pancreas in an adult is the first of its kind in our center;.

  6. Generation Mechanisms of Quasi-parallel and Quasi-circular Flare Ribbons in a Confined Flare

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Perez, Aaron; Thalmann, Julia K.; Veronig, Astrid M.; Dickson, Ewan C. [IGAM/Institute of Physics, University of Graz, A-8010 Graz (Austria); Su, Yang [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory Chinese Academy of Sciences, 2 West Beijing Road, 210008 Nanjing (China); Gömöry, Peter, E-mail: aaron.hernandez-perez@uni-graz.at [Astronomical Institute, Slovak Academy of Sciences, 05960 Tatranská Lomnica (Slovakia)

    2017-10-01

    We analyze a confined multiple-ribbon M2.1 flare (SOL2015-01-29T11:42) that originated from a fan-spine coronal magnetic field configuration, within active region NOAA 12268. The observed ribbons form in two steps. First, two primary ribbons form at the main flare site, followed by the formation of secondary ribbons at remote locations. We observe a number of plasma flows at extreme-ultraviolet temperatures during the early phase of the flare (as early as 15 minutes before the onset) propagating toward the formation site of the secondary ribbons. The secondary ribbon formation is co-temporal with the arrival of the pre-flare generated plasma flows. The primary ribbons are co-spatial with Ramaty High Energy Spectroscopic Imager ( RHESSI ) hard X-ray sources, whereas no enhanced X-ray emission is detected at the secondary ribbon sites. The (E)UV emission, associated with the secondary ribbons, peaks ∼1 minute after the last RHESSI hard X-ray enhancement. A nonlinear force-free model of the coronal magnetic field reveals that the secondary flare ribbons are not directly connected to the primary ribbons, but to regions nearby. Detailed analysis suggests that the secondary brightenings are produced due to dissipation of kinetic energy of the plasma flows (heating due to compression), and not due to non-thermal particles accelerated by magnetic reconnection, as is the case for the primary ribbons.

  7. Persistent ectopic pregnancy after milking procedure: Case report

    Directory of Open Access Journals (Sweden)

    Semra Kayataş

    2014-03-01

    Full Text Available Ectopic pregnancy is the settlement of the pregnancy product at any site other than the endometrium. The incidence of ectopic pregnancy have increased in the last 20 years. Increased frequency and early diagnosis has led to conservative treatment methods to become more favorable. Follow-up, medical management and surgical managements are considered as conservative methods. As salpingostomy is the most common conservative surgical method, milking is considered as an alternative conservative surgical method. The most important complication of the conservative surgery is the persistence of ectopic pregnancy because of the residual trophoblastic tissue. Since the prediction of the persistent ectopic pregnancy is difficult after the conservative surgery, β-HCG follow up is so important for early diagnosis. In this case report we have discussed the case of the patient who admitted to our clinic with persistent ectopic pregnancy with acute abdomen, after the treatment with milking procedure whom than treated by salpingectomy procedure.

  8. Role of ultrasound in detection of ectopic pregnancy: our experience

    International Nuclear Information System (INIS)

    Moshin, H.; Khan, M.N.; Jadun, C.K.; Tanveer-ul-Jaq

    2001-01-01

    Objective: To determine the efficacy of ultrasound in detection of ectopic pregnancy. Design: It was an observational and prospective study. The study was conducted from January, 2000 in the Radiology Department of the Agha Khan University Hospital, Karachi. Subjects and Methods: Four hundred patients were referred for sonography with a query of ectopic pregnancy. Most of the patients had clinical symptoms of vaginal bleeding and lower abdominal pain with history of missed periods. For the evaluation biphasic ultrasound was performed that included suprapubic and trans vaginal ultrasound. After analyzing internal architecture prospective sonographic diagnosis was made. Results: The most common site of ectopic pregnancy was fallopian tubes. Positive diagnosis was made in 96.3% cases and negative diagnosis in 4.7% cases in our study. Conclusion: Efficacy of ultrasound was found to be 96.4% in the detection of ectopic pregnancy and hence plays a very important role in early diagnosis of ectopic pregnancy. (author)

  9. Spatiotemporal regulation of ATP and Ca2+ dynamics in vertebrate rod and cone ribbon synapses.

    Science.gov (United States)

    Johnson, Jerry E; Perkins, Guy A; Giddabasappa, Anand; Chaney, Shawntay; Xiao, Weimin; White, Andrew D; Brown, Joshua M; Waggoner, Jenna; Ellisman, Mark H; Fox, Donald A

    2007-06-15

    stained for PMCA, whereas the larger cone pedicles preferentially stained for NCX1 at their active zones and PMCA near their mitochondria. EM and ET revealed that mitochondria in rod spherules and cone pedicles differed markedly in their number, location, size, volume, and total cristae surface area, and cristae junction diameter. Rod spherules had one large ovoid mitochondrion located near its active zone, whereas cone pedicles averaged five medium-sized mitochondria clustered far from their active zones. Most spherules had one ribbon synapse, whereas pedicles contained numerous ribbon synapses. Fluo-3 imaging studies revealed that during darkness rod spherules maintained a lower [Ca2+] than cone pedicles, whereas during light adaptation pedicles rapidly lowered their [Ca2+] below that observed in spherules. These findings indicate that ATP demand and mitochondrial ATP production are greater in cone pedicles than rod spherules. Rod spherules employ high affinity/low turnover PMCA and their mitochondrion to maintain a relatively low [Ca2+] in darkness, which increases their sensitivity and signal-to-noise ratio. In contrast, cone pedicles utilize low affinity/high turnover NCX to rapidly lower their high [Ca2+] during light adaptation, which increases their response kinetics. Spatiotemporal fluo-3-Ca2+ imaging results support our immunocytochemical results. The clustering of cone pedicle mitochondria likely provides increased protection from Ca2+ overload and permeability transition. In summary, these novel studies reveal that several integrated cellular and subcellular components interact to regulate ATP and Ca2+ dynamics in rod and cone synaptic terminals. These results should provide a greater understanding of in vivo photoreceptor synaptic terminal exocytosis/endocytosis, Ca2+ overload and therapies for retinal degenerations.

  10. Bilateral cervical ectopic thymic nodules with accessory thyroid tissue and an ectopic parathyroid in the neck region

    Directory of Open Access Journals (Sweden)

    Wea-Lung Lin

    2011-03-01

    Full Text Available Some remnants of thymic tissue may be deposited along the pathway of the descent of the neck during embryologic development of the thymus. Ectopic thymic tissue is usually deposited along the pathway from the mandibular angle to the manubrium of the sternum. Most reported cases of an ectopic thymus occurred in children, and cases are less common in adults. We report a 26-year-old woman, who was incidentally found to have 2 neck nodules on the posterior side of the bilateral upper pole of the thyroid gland while undergoing a subtotal thyroidectomy. The left-side neck nodule showed accessory thyroid follicles intermixed with ectopic thymic tissue, and the right-side neck nodule was ectopic parathyroid tissue together with ectopic thymic tissue.

  11. Characterization of consolidated rapidly solidified Cu-Nb ribbons

    International Nuclear Information System (INIS)

    Ebrahimi, F.; Henne, M.L.C.

    1997-01-01

    Copper-niobium ribbons produced by melt-spinning were compacted by swaging and consolidated using HIPping. Final processing to obtain in-situ composites was done by swaging. The strength of the composite is discussed in terms of the composition and morphology of the niobium phase as evaluated using electron microscopy techniques

  12. 38 CFR 21.9700 - Yellow Ribbon Program.

    Science.gov (United States)

    2010-07-01

    ... Yellow Ribbon Program and the student maintains satisfactory progress, conduct, and attendance according...) Based on student status (i.e. , undergraduate, graduate, doctoral), or (ii) For each subelement of the institution (i.e., college or professional school). The maximum amount specified for each subelement of the...

  13. Dosimetry of wires and single ribbons of Iridium 192

    International Nuclear Information System (INIS)

    Mazzucco, L.D.

    1998-01-01

    The objective of this work is in order to present in table formats the dosimetry of wires and single ribbons of Iridium with lengths 1-12 cm for each one linear source along the bisector which is perpendicular at tissue sources (water) computed for linear activity 1 mCi/cm in the case of wires, and 1 mCi/seed for ribbons. The above tables are of direct use, adaptable at particular cases so they facilitate logarithmic graphics of doses in function of the distance for interpolation and use in the treatments planning. It was shown that for two sources with identical linear activity and total length, one of the equidistant seeds at 1 cm (ribbon) and one wire on the other hand, the differences in dose rates in near positions can be about the 15% so corroborating that it is not possible to use wire tables for seeds neither vice versa. Moreover it was elaborated tables of practical direct use for dose rate in water at c Gy/hr for wires and Ribbons 1-12 cm length and from 0.5-10 cm of distance in the perpendicular bisector at the Iridium implant. (Author)

  14. Experimental investigation of the ribbon-array ablation process

    International Nuclear Information System (INIS)

    Li Zhenghong; Xu Rongkun; Chu Yanyun; Yang Jianlun; Xu Zeping; Ye Fan; Chen Faxin; Xue Feibiao; Ning Jiamin; Qin Yi; Meng Shijian; Hu Qingyuan; Si Fenni; Feng Jinghua; Zhang Faqiang; Chen Jinchuan; Li Linbo; Chen Dingyang; Ding Ning; Zhou Xiuwen

    2013-01-01

    Ablation processes of ribbon-array loads, as well as wire-array loads for comparison, were investigated on Qiangguang-1 accelerator. The ultraviolet framing images indicate that the ribbon-array loads have stable passages of currents, which produce axially uniform ablated plasma. The end-on x-ray framing camera observed the azimuthally modulated distribution of the early ablated ribbon-array plasma and the shrink process of the x-ray radiation region. Magnetic probes measured the total and precursor currents of ribbon-array and wire-array loads, and there exists no evident difference between the precursor currents of the two types of loads. The proportion of the precursor current to the total current is 15% to 20%, and the start time of the precursor current is about 25 ns later than that of the total current. The melting time of the load material is about 16 ns, when the inward drift velocity of the ablated plasma is taken to be 1.5 × 10 7 cm/s.

  15. Magnetoimpedance of cobalt-based amorphous ribbons/polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Semirov, A.V., E-mail: semirov@mail.ru [Irkutsk State University, Irkutsk (Russian Federation); Derevyanko, M.S.; Bukreev, D.A.; Moiseev, A.A.; Kudryavtsev, V.O. [Irkutsk State University, Irkutsk (Russian Federation); Safronov, A.P. [Ural Federal University, Yekaterinburg (Russian Federation)

    2016-10-01

    The combined influence of the temperature, the elastic tensile stress and the external magnetic field on the total impedance and impedance components were studied for rapidly quenched amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons. Both as-cast amorphous ribbons and Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16}/polymer amorphous ribbon based composites were considered. Following polymer coverings were studied: modified rubber solution in o-xylene, solution of butyl methacrylate and methacrylic acid copolymer in isopropanol and solution of polymethylphenylsiloxane resin in toluene. All selected composites showed very good adhesion of the coverings and allowed to provide temperature measurements from 163 K up to 383 K under the applied deforming tensile force up to 30 N. The dependence of the modulus of the impedance and its components on the external magnetic field was influenced by the elastic tensile stresses and was affected by the temperature of the samples. It was shown that maximal sensitivity of the impedance and its components to the external magnetic field was observed at minimal temperature and maximal deforming force depended on the frequency of an alternating current. - Highlights: • Impedance and its components of amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons were studied. • MI sensitivity to the magnetic field depends on a temperature and a deforming force. • Polymer covering can affect the functional properties of the composite.

  16. Flare Ribbon Expansion and Energy Release Ayumi Asai , Takaaki ...

    Indian Academy of Sciences (India)

    2001-04-10

    1Nobeyama Solar Radio Observatory, Minamisaku, Nagano, 384-1305, Japan. ... X2.3 solar flare which occurred on April 10, 2001. .... In the right panel of. Fig. 3, we show the temporal variation of the physical parameters, such as Bp, vf , ˙ , and S along a slit line. Here, we defined vf as the speed of the flare-ribbon ...

  17. Structural relaxation of Ni-Si-B amorphous ribbon

    NARCIS (Netherlands)

    Jurikova, A.; Csach, K.; Miskuf, J.; Ocelik, V.

    The structural relaxation of the Ni-Si-B amorphous ribbon was studied by means of differential scanning calorimetry and thermomechanical analysis. It was shown that considerable length changes associated with reversible structural relaxation were revealed after a previous creep applied at higher

  18. Graphene: powder, flakes, ribbons, and sheets.

    Science.gov (United States)

    James, Dustin K; Tour, James M

    2013-10-15

    Graphene's unique physical and electrical properties (high tensile strength, Young's modulus, electron mobility, and thermal conductivity) have led to its nickname of "super carbon." Graphene research involves the study of several different physical forms of the material: powders, flakes, ribbons, and sheets and others not yet named or imagined. Within those forms, graphene can include a single layer, two layers, or ≤10 sheets of sp² carbon atoms. The chemistry and applications available with graphene depend on both the physical form of the graphene and the number of layers in the material. Therefore the available permutations of graphene are numerous, and we will discuss a subset of this work, covering some of our research on the synthesis and use of many of the different physical and layered forms of graphene. Initially, we worked with commercially available graphite, with which we extended diazonium chemistry developed to functionalize single-walled carbon nanotubes to produce graphitic materials. These structures were soluble in common organic solvents and were better dispersed in composites. We developed an improved synthesis of graphene oxide (GO) and explored how the workup protocol for the synthesis of GO can change the electronic structure and chemical functionality of the GO product. We also developed a method to remove graphene layers one-by-one from flakes. These powders and sheets of GO can serve as fluid loss prevention additives in drilling fluids for the oil industry. Graphene nanoribbons (GNRs) combine small width with long length, producing valuable electronic and physical properties. We developed two complementary syntheses of GNRs from multiwalled carbon nanotubes: one simple oxidative method that produces GNRs with some defects and one reductive method that produces GNRs that are less defective and more electrically conductive. These GNRs can be used in low-loss, high permittivity composites, as conductive reinforcement coatings on Kevlar

  19. The status of silicon ribbon growth technology for high-efficiency silicon solar cells

    Science.gov (United States)

    Ciszek, T. F.

    1985-01-01

    More than a dozen methods have been applied to the growth of silicon ribbons, beginning as early as 1963. The ribbon geometry has been particularly intriguing for photovoltaic applications, because it might provide large area, damage free, nearly continuous substrates without the material loss or cost of ingot wafering. In general, the efficiency of silicon ribbon solar cells has been lower than that of ingot cells. The status of some ribbon growth techniques that have achieved laboratory efficiencies greater than 13.5% are reviewed, i.e., edge-defined, film-fed growth (EFG), edge-supported pulling (ESP), ribbon against a drop (RAD), and dendritic web growth (web).

  20. Risk Factors For Ectopic Pregnancy : A Case Control Study

    Directory of Open Access Journals (Sweden)

    Deshmukh J.S

    1999-01-01

    Full Text Available Research question: Which are the risk factors for ectopic pregnancy . Objective: To study the strength of association between hypothesised risk factors and ectopic pregnancy. Study design: Unmatched case- control study. Setting: Government Medical College, Hospital, Nagpur. Participants: 133 cases of ectopic pregnancy and equal number of controls (non pregnant women admitted to study hospital. Study variables : Pelvic inflammatory diseases, sexually transmitted diseases, IUD use at conception , past use of IUD, prior ectopic pregnancy, OC pills use at the time of conception, past use of OC pills, induced abortion, spontaneous abortion, infertility and pelvic and abdominal surgery. Statistical analysis: Odds ratios & their 95% CI, Pearson’s chi square test, unconditional logistic regression analysis and population attributable risk proportion. Results : Use of IUD at conception, prior ectopic pregnancy , pelvic inflammatory disease, sexually transmitted diseases, infertility, OC pills use at the time of conception, past use of IUD and induced abortion were found to be significantly associated with ectopic pregnancy. Conclusion: Identification of these risk factors for etopic pregnancy shall help in early detection and appropriate management in an individual case and it may help in devising a comprehensive preventive strategy for ectopic pregnancy

  1. Dosimetry of wires and single ribbons of Iridium 192; Dosimetria de alambres y ribbons individuales de Iridio-192

    Energy Technology Data Exchange (ETDEWEB)

    Mazzucco, L.D. [Centro Medico Nuclear S.R.L. San Juan (Argentina)

    1998-12-31

    The objective of this work is in order to present in table formats the dosimetry of wires and single ribbons of Iridium with lengths 1-12 cm for each one linear source along the bisector which is perpendicular at tissue sources (water) computed for linear activity 1 mCi/cm in the case of wires, and 1 mCi/seed for ribbons. The above tables are of direct use, adaptable at particular cases so they facilitate logarithmic graphics of doses in function of the distance for interpolation and use in the treatments planning. It was shown that for two sources with identical linear activity and total length, one of the equidistant seeds at 1 cm (ribbon) and one wire on the other hand, the differences in dose rates in near positions can be about the 15% so corroborating that it is not possible to use wire tables for seeds neither vice versa. Moreover it was elaborated tables of practical direct use for dose rate in water at c Gy/hr for wires and Ribbons 1-12 cm length and from 0.5-10 cm of distance in the perpendicular bisector at the Iridium implant. (Author)

  2. Synaptic control of motoneuronal excitability

    DEFF Research Database (Denmark)

    Rekling, J C; Funk, G D; Bayliss, D A

    2000-01-01

    important in understanding the transformation of neural activity to motor behavior. Here, we review recent studies on the control of motoneuronal excitability, focusing on synaptic and cellular properties. We first present a background description of motoneurons: their development, anatomical organization......, and membrane properties, both passive and active. We then describe the general anatomical organization of synaptic input to motoneurons, followed by a description of the major transmitter systems that affect motoneuronal excitability, including ligands, receptor distribution, pre- and postsynaptic actions...... and norepinephrine, and neuropeptides, as well as the glutamate and GABA acting at metabotropic receptors, modulate motoneuronal excitability through pre- and postsynaptic actions. Acting principally via second messenger systems, their actions converge on common effectors, e.g., leak K(+) current, cationic inward...

  3. Ectopic Neurohypophysis in Patient with Pituitary Dwarfism: A Case Report

    Directory of Open Access Journals (Sweden)

    İlhan Kılınç

    2008-09-01

    Full Text Available Ectopic neurohypophysis is an anomaly of the Pituitary gland whichmay be associated with short stature due to Growth hormone deficiency.MRI is the modality of choice in diagnosing this condition. We present acase of pituitary dwarfism and ectopic neurohypophysis with clinical andradiological findings. 21 year-old male admitted with short stature. Allhormones, except prolactin, of anterior hypophysis were low. Bright spotwas ectopically located at level of median eminence on enhanced MRI ofhypophysis and stalk of hypophysis was not observed. Ectopicneurohypophysis may be present with pituitary dwarfism. Cranial MRI maybe useful to investigate related pathologies in such cases.

  4. Twenty cases of ectopic thyroid gland detected by thyroid scintigraphy

    International Nuclear Information System (INIS)

    Hashimoto, Teisuke; Kubo, Atsushi; Hashimoto, Shozo

    1988-01-01

    20 cases of ectopic thyroid gland were detected out of 5,261 thyroid scintigraphy from 1973. Except for 1 case, all cases were female. Considering of thyroid function, 11 cases were euthyroid and rest of 9 cases were hypothyroid function. Clinical symptom of hypothyroid cases were mainly retarded linear growth and high value of serum TSH and in case of euthyroid cases were sublingual tumor and fullness or tightness in throat. Thyroid scintigraphy is very useful to diagnose the sublingual tumor whether it is ectopic thyroid gland or not. In case of congenital hypothyroidism children, ectopic thyroid gland causing hypothyroidism is definitely diagnosed by thyroid scintigraphy. (author)

  5. Papillary carcinoma in median aberrant thyroid (ectopic) - case report.

    Science.gov (United States)

    Hebbar K, Ashwin; K, Shashidhar; Deshmane, Vijaya Laxmi; Kumar, Veerendra; Arjunan, Ravi

    2014-06-01

    Median ectopic thyroid may be encountered anywhere from the foramen caecum to the diaphragm. Non lingual median aberrant thyroid (incomplete descent) usually found in the infrahyoid region and malignant transformation in this ectopic thyroid tissue is very rare. We report an extremely rare case of papillary carcinoma in non lingual median aberrant thyroid in a 25-year-old female. The differentiation between a carcinoma arising in the median ectopic thyroid tissue and a metastatic papillary carcinoma from an occult primary in the main thyroid gland is also discussed.

  6. Ectopic pituitary adenoma presenting as midline nasopharyngeal mass.

    LENUS (Irish Health Repository)

    Ali, R

    2012-02-01

    INTRODUCTION: Ectopic pituitary adenomas are extremely rare. We report a case of ectopic pituitary adenoma in the midline of the nasopharynx. This adenoma probably arose from the pharyngeal remnant of Rathke\\'s pouch. METHODS: We discuss a case of a lady who presented to our unit with 2 months history of dryness and sensation of lump in her throat and a long standing history of hypothyroidism. Examination of nasopharynx revealed a smooth and fluctuant midline mass. CT scan of nose and paranasal sinuses confirmed the midline mass with small defect communicating with the sphenoid sinus. An initial diagnosis of Thornwaldt\\'s cyst was made and she underwent upper aerodigestive tract endoscopy and marsupialization of the mass. Histopathological examination revealed ectopic pituitary adenoma. CONCLUSION: Ectopic pituitary adenoma is an important differential diagnosis for a midline nasopharyngeal mass. It is recommended that prior to surgical resection of midline nasopharyngeal mass biopsy is taken and MRI is performed.

  7. Ectopic pregnancy experience in a tertiary health facility in South ...

    African Journals Online (AJOL)

    Celestine

    Methods: A retrospective study of all cases of ectopic pregnancies managed at the University of Port. Harcourt .... study was obtained from the ethics committee of the hospital. .... Business woman. 54. 15.7 .... Dewhurst`s Textbook of Obstetrics.

  8. Ectopic third molar in maxillary sinus: A rare case report

    Directory of Open Access Journals (Sweden)

    Abhishek Sinha

    2017-01-01

    Full Text Available Ectopic tooth eruption in a non-dental area is a rare entity, and is most common in oral cavity. There have been a few case reports of teeth erupting in mandibular condyle, chin, palate, coronoid process, and maxillary sinus. Ectopic tooth in the maxillary sinus are found incidentally on routine radiological examination, same time they can be symptomatic and associated with pathologies usually dentigerous cyst or odontogenic keratocyst. Facial pain, purulent rhinorrhoea, epistaxis, headache, swelling, and epiphora-related naso-lacrimal duct obstruction can also be seen. By Caldwell-Luc procedure the ectopic teeth within the maxillary sinus are often removed. In this study, a case of ectopic maxillary third molar tooth on right maxillary sinus is presented.

  9. Dentigerous Cyst Associated with Ectopic Canine and a ...

    African Journals Online (AJOL)

    ankylosis, cystic or neoplastic lesion or trauma may be the local factors ... After clinical and radiographic examination, a provisional diagnosis of ... bone along with the impacted teeth (permanent ectopic canine ... [7] Panoramic radiograph and ...

  10. Modern Technologies In Ectopic Pregnancy Diagnostics On Hospital Stage

    Directory of Open Access Journals (Sweden)

    L.V. Kaushanskaya

    2009-12-01

    Full Text Available The present research provides analysis of results of preoperative examination of 680 patients with ectopic pregnancy depending on the range of surgical treatment. It has been shown that in case of progressive ectopic pregnancy the diagnostic significance of concentrations of human chorionic gonadotropin, transvaginal examination and laparos-copy depends on the duration of pregnancy. When the term of ectopic pregnancy is 3-4 weeks monitoring of p chorionic gonadotropin in blood serum (99.5%, transvaginal examination (58% and laparoscopy (78.5% are more informative. When the term of ectopic pregnancy is more than 4 weeks there is a high diagnostic value of monitoring p-subunit of chorionic gonadotropin (99.5%, transvaginal examination (68% and laparoscopy (99,5%. The research has proved that pregnancy period of 3-4 weeks is optimal for laparoscopy and other operations

  11. Ectopic pregnancy: current clinical trends, a fifteen year study.

    Science.gov (United States)

    Weekes, L R

    1981-09-01

    This paper reviews the clinical recognition, diagnosis, and management of ectopic pregnancy at the Queen of Angels Hospital for the past 15 years. The incidence of ectopic pregnancy to deliveries is 1:195. Pain is the cardinal symptom of ectopic pregnancy, and amenorrhea of some degree was present in all cases. Pelvic inflammatory disease is a factor in the development of tubal pregnancy in some women. A careful history and thorough physical examination are important in making a careful diagnosis. The only laboratory procedures which are of any value are the blood type and the Rh determination. While examination of endometrial tissue obtained by biopsy or curettage has proved useful in ectopic pregnancy diagnosis, it is not totally decisive. Culdocentesis has proved to be the diagnostic procedure of the greatest value in recognizing intraperitoneal hemorrhage and it increases the correct preoperative diagnosis from 65-70% to 95%. Laparoscopy is useful when the physician is in doubt about the nature of the problem and it has produced an increase in the number of ectopic pregnancies diagnosed. Ultrasound is another useful tool in confirming a diagnosis of ectopic pregnancy; its accuracy ranges from 70-92%. A newly developed pregnancy test is more sensitive than conventional pregnancy tests and would be positive for pregnancy. Women who have had a previous ectopic pregnancy have a higher subsequent incidence of persistent infertility, recurrent ectopic pregnancy, and pregnancy wastage; the risk of another ectopic pregnancy increases 30-50 fold. While extopic pregnancy does recur, it is true that about 1/3 of those women do have successful pregnancies. Where previous induced abortion has occurred, there is a 10-fold increased risk of ectopic pregnancy. Women who become pregnant accidentally with an IUD in place have a greater likelihood of experiencing an extrauterine pregnancy. Abdominal pregnancy is often encountered as an aborting ectopic pregnancy during the 1st

  12. Repair of osteochondral defects in rabbits with ectopically produced cartilage

    NARCIS (Netherlands)

    Emans, PJ; Hulsbosch, M; Wetzels, GMR; Bulstra, SK; Kuijer, R

    2005-01-01

    Cartilage has poor regenerative capacity. Donor site morbidity and interference with joint homeostasis should be considered when applying the autologous chondrocyte transplantation technique. The use of ectopically produced cartilage, derived from periosteum, might be a novel method to heal

  13. Dysfunctional ectopic thyroid gland: A case report

    Directory of Open Access Journals (Sweden)

    Stokić Edita

    2014-01-01

    Full Text Available Introduction. Lingual thyroid gland is a rare anomaly of thyroid gland development, occurring more frequently in females. If it causes local symptomatology such as dysphagia, dysphonia or dyspnea it is diagnosed in childhood, however, if it is asymptomatic it is usually diagnosed in adulthood. Case Outline. We present a 23-year-old female patient in whom we diagnosed lingual thyroid gland coincidentally during diagnostic procedures of a concomitant disease. The application of 131I scintigraphy showed an oval field of intensive accumulation of radio markers in the zone of medial face line, around tongue base, with the absence of thyroid gland in its physiological position. Functional testing proved primary hypothyroidism and we started the application of substitution therapy. The application of levothyroxine resulted in reaching euthyroid state and the reduction of thyroid gland size. Conclusion. We present a very rare anomaly of the thyroid gland, and so far there have been no clear attitudes about further treatment. The general condition of the patient, age, the size of ectopic thyroid gland and the existence of local symptomatology or complications represent the factors that have influence on the choice of treatment method.

  14. Ectopic pregnancy in women with recurrent miscarriage.

    Science.gov (United States)

    Ticconi, Carlo; Capogna, Maria V; Martelli, Federica; Borelli, Barbara; Bruno, Valentina; Ergasti, Raffaella; Sorge, Roberto; Piccione, Emilio; Pietropolli, Adalgisa

    2018-05-01

    The aim of this study was to investigate the possible association between recurrent miscarriage (RM) and ectopic pregnancy (EP). In this case-control retrospective study, the clinical cards of women followed as outpatients in the RM and low-risk pregnancy offices of the Obstetrics and Gynecology Unit at the Policlinico Tor Vergata University Hospital were carefully reviewed for the occurrence of EP. Overall, 598 women with RM and 2043 normal women without RM (controls) were included in the study. Among these women, 4974 pregnancies were analyzed, in which 2028 miscarriages occurred. The EP rate (3.51%) was significantly higher in RM than in control women (1.51%) [odds ratio = 2.31 (95% confidence interval: 2.3-2.4)]; it was particularly high in women with primary RM (5.11%). However, when EP rates were calculated not by women but by overall pregnancies, no differences could be found between RM and control women. In control women, the absence of a miscarriage in the reproductive history was associated with a lower rate of EP. Women with RM, particularly primary RM, are at increased risk of EP. This increased risk seems to be dependent on the high number of pregnancies occurring in women with RM rather than to specific characteristics of these women. © 2018 Japan Society of Obstetrics and Gynecology.

  15. Magnetic resonance urography in duplex kidney with ectopic ureteral insertion

    Directory of Open Access Journals (Sweden)

    Conjeevaram Rajendrarao Thambidorai

    2011-01-01

    Full Text Available This is a report on the use of magnetic resonance urography (MRU in a 6-year-old girl who presented with urinary incontinence. She had a left duplex kidney with poorly functioning upper moiety and ectopic insertion of the dilated upper pole ureter. MRU has been shown to be superior to conventional imaging techniques in delineating poorly functioning moieties of duplex kidneys and ectopic ureters.

  16. Endosonographic Features of Histologically Proven Gastric Ectopic Pancreas

    Directory of Open Access Journals (Sweden)

    Jen-Wei Chou

    2014-01-01

    Full Text Available Gastric ectopic pancreas is an uncommon developmental anomaly and its histological diagnosis is usually difficult by using a conventional biopsy forceps. In the literature, most cases of gastric ectopic pancreas were usually diagnosed by gross pattern during endoscopic examination or features of endoscopic ultrasound. In contrast, this disease was seldom diagnosed by histology in clinical practice. Although the typical endoscopic ultrasonographic features of ectopic pancreas include heterogeneous echogenicity, indistinct borders, and a location within 2 or more layers, it can also exhibit hypoechoic homogeneous echogenicity and a distinct border within the fourth sonographic layer (muscularis propria similar to the endoscopic ultrasonographic features of gastrointestinal stromal tumors. In our study, we found that 53% of gastric ectopic pancreas originated within the fourth sonographic layer, demonstrating hypoechoic, homogeneous echogenicity, and distinct borders. Therefore, recognizing endoscopic ultrasonographic features, combining with deep biopsy, endoscopic ultrasound-guided fine needle aspiration/core needle biopsy can prevent conducting unnecessary resection. Surgical resection is the mainstay treatment for symptomatic gastric ectopic pancreas, but endoscopic resection using endoscopic mucosal resection or endoscopic submucosal dissection technique provides an alternative method of removing superficial-type and deep-type gastric ectopic pancreas.

  17. Transverse magnetization and giant magnetoimpedance in amorphous ribbons

    International Nuclear Information System (INIS)

    Orue, I.; Garcia-Arribas, A.; Saad, A.; Cos, D. de; Barandiaran, J.M.

    2005-01-01

    In the classical approach giant magnetoimpedance (GMI) is driven by the transverse permeability of the sample, as excited by the current flowing through it. Transverse permeability is usually taken as a constant, while detailed magnetization processes are important for the interpretation of GMI data. In most cases the transverse permeability (or magnetization) is only guessed by looking at the longitudinal magnetization curve and direct determinations of such parameter are scarce in the literature. In this work we report on the operation of a simple setup which provides the transverse magnetization of amorphous ribbons as a function of the current intensity flowing through it, by means of the magnetooptical kerr effect (MOKE). The system has been tested on low magnetostriction amorphous ribbons of very soft character with both longitudinal and transverse anisotropy. The transverse magnetization as a function of both the current and a DC longitudinal field applied, was compared with magneto impedance measurements

  18. Device for investigation of magnetic flux jumps in ribbon superconductors

    International Nuclear Information System (INIS)

    Andrianov, A.V.; Bashkirov, Yu.A.; Kremlev, M.G.

    1986-01-01

    A device for simulation of magnetic flux jumps in superconductors of conducting magnet sandwich-type windings super-applyed of a ribbon conductor is described. A superconducting magnet with a measuring cassetter are the main elements of the device. An external magnetic field is generated by a two-sectional superconducting magnet permitting to simulate the shape of the magnetic field characteristic for sandwich-type windings. Maximum radial component of the magnetic field is 2 T. Jumps of the magnetic flux are recorded by induction transducers and the magnetic field-by Hall trasducer. The effect of coating of standard metal on magnetic flux jumps in Nb 3 Sn base superconducting ribbon is considered

  19. Variation of boron concentration in metallic glass ribbons

    International Nuclear Information System (INIS)

    Nagy, A.Z.; Vasvari, B.; Duwez, P.; Bakos, L.; Seres, Z.; Bogancs, J.; Nazarov, V.M.

    1979-12-01

    The surface boron concentration of Fe 40 Ni 40 P 14 B 6 , Fe 32 Ni 36 Cr 14 P 12 B 6 and Fe 40 Ni 40 B 20 metallic glasses was measured by neutron activation analysis on both sides of the ribbon samples. It was found that the boron concentration is always higher at the bright side of the ribbon than that at the dull side which is in contact with the cold surface of the wheel during the rapid quenching from the melt. A possible explanation is given in terms of the solid-liquid interface moving rapidly from the cooled surface to the free surface when preparing the samples. Range values of alpha-particles for some characteristic compositions of metallic glasses are tabulated. A mathematical technique for the deconvolution of experimental data is described and the listing of the Fortran program is enclosed. (author)

  20. Ectopic Pelvic Kidney With Urinary Tract Infection Presenting as Lower Abdominal Pain in a Child

    OpenAIRE

    Chung-Ching Lu; You-Lin Tain; Kwok-Wan Yeung; Mao-Meng Tiao

    2011-01-01

    Ectopic pelvic kidney is a rare developmental anomaly. Ectopic pelvic kidney can present without the characteristic symptoms associated with the urinary tract pathology. Ectopic pelvic kidney is usually unknown, and nonspecific vague abdominal comfort maybe the only symptom. Early detection and recognition of an ectopic kidney can prevent long-term complications. We report a 3-year-5-month-old girl with ectopic pelvic kidney who experienced intermittent episodes of lower abdominal pain for ab...

  1. HOOKED FLARE RIBBONS AND FLUX-ROPE-RELATED QSL FOOTPRINTS

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jie; Li, Hui [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, CAS, Nanjing 210008 (China); Gilchrist, Stuart A.; Aulanier, Guillaume; Schmieder, Brigitte; Pariat, Etienne, E-mail: nj.lihui@pmo.ac.cn [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris-Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France)

    2016-05-20

    We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory /Atmospheric Imaging Assembly can be well reproduced from a Grad–Rubin nonlinear force-free field extrapolation method. Various inverse-S- and inverse-J-shaped magnetic field lines, which surround a coronal flux rope, coincide with the sigmoid as observed in different extreme-ultraviolet wavelengths, including its multithreaded curved ends. Also, the observed distribution of surface currents in the magnetic polarity where it was not prescribed is well reproduced. This validates our numerical implementation and setup of the Grad–Rubin method. The modeled double inverse-J-shaped quasi-separatrix layer (QSL) footprints match the observed flare ribbons during the rising phase of the flare, including their hooked parts. The spiral-like shape of the latter may be related to a complex pre-eruptive flux rope with more than one turn of twist, as obtained in the model. These ribbon-associated flux-rope QSL footprints are consistent with the new standard flare model in 3D, with the presence of a hyperbolic flux tube located below an inverse-teardrop-shaped coronal QSL. This is a new step forward forecasting the locations of reconnection and ribbons in solar flares and the geometrical properties of eruptive flux ropes.

  2. HOOKED FLARE RIBBONS AND FLUX-ROPE-RELATED QSL FOOTPRINTS

    International Nuclear Information System (INIS)

    Zhao, Jie; Li, Hui; Gilchrist, Stuart A.; Aulanier, Guillaume; Schmieder, Brigitte; Pariat, Etienne

    2016-01-01

    We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory /Atmospheric Imaging Assembly can be well reproduced from a Grad–Rubin nonlinear force-free field extrapolation method. Various inverse-S- and inverse-J-shaped magnetic field lines, which surround a coronal flux rope, coincide with the sigmoid as observed in different extreme-ultraviolet wavelengths, including its multithreaded curved ends. Also, the observed distribution of surface currents in the magnetic polarity where it was not prescribed is well reproduced. This validates our numerical implementation and setup of the Grad–Rubin method. The modeled double inverse-J-shaped quasi-separatrix layer (QSL) footprints match the observed flare ribbons during the rising phase of the flare, including their hooked parts. The spiral-like shape of the latter may be related to a complex pre-eruptive flux rope with more than one turn of twist, as obtained in the model. These ribbon-associated flux-rope QSL footprints are consistent with the new standard flare model in 3D, with the presence of a hyperbolic flux tube located below an inverse-teardrop-shaped coronal QSL. This is a new step forward forecasting the locations of reconnection and ribbons in solar flares and the geometrical properties of eruptive flux ropes.

  3. Broadband magnetic losses of nanocrystalline ribbons and powder cores

    Energy Technology Data Exchange (ETDEWEB)

    Beatrice, Cinzia, E-mail: c.beatrice@inrim.it [Istituto Nazionale di Ricerca Metrologica, Nanoscience and Materials Division, Torino (Italy); Dobák, Samuel [Institute of Physics, Faculty of Science, P.J. Šafárik University, Košice (Slovakia); Ferrara, Enzo; Fiorillo, Fausto [Istituto Nazionale di Ricerca Metrologica, Nanoscience and Materials Division, Torino (Italy); Ragusa, Carlo [Politecnico di Torino, Energy Department, Torino (Italy); Füzer, Ján; Kollár, Peter [Institute of Physics, Faculty of Science, P.J. Šafárik University, Košice (Slovakia)

    2016-12-15

    Finemet type alloys have been investigated from DC to 1 GHz at different induction levels upon different treatments: as amorphous precursors, as ribbons nanocrystallized with and without an applied saturating field, as consolidated powders. The lowest energy losses at all frequencies and maximum Snoek's product are exhibited by the transversally field-annealed ribbons. This is understood in terms of rotation-dominated magnetization process in the low-anisotropy material. Intergrain eddy currents are responsible for the fast increase of the losses with frequency and for early permeability relaxation of the powder cores. Evidence for resonant phenomena at high frequencies and for the ensuing inadequate role of the static magnetic constitutive equation of the material in solving the magnetization dynamics via the Maxwell's diffusion equation of the electromagnetic field is provided. It is demonstrated that, by taking the Landau–Lifshitz–Gilbert equation as a constitutive relation, the excellent frequency response of the transverse anisotropy ribbons can be described by analytical method.

  4. Synaptic vesicle distribution by conveyor belt.

    Science.gov (United States)

    Moughamian, Armen J; Holzbaur, Erika L F

    2012-03-02

    The equal distribution of synaptic vesicles among synapses along the axon is critical for robust neurotransmission. Wong et al. show that the continuous circulation of synaptic vesicles throughout the axon driven by molecular motors ultimately yields this even distribution. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Spontaneous Vesicle Recycling in the Synaptic Bouton

    Directory of Open Access Journals (Sweden)

    Sven eTruckenbrodt

    2014-12-01

    Full Text Available The trigger for synaptic vesicle exocytosis is Ca2+, which enters the synaptic bouton following action potential stimulation. However, spontaneous release of neurotransmitter also occurs in the absence of stimulation in virtually all synaptic boutons. It has long been thought that this represents exocytosis driven by fluctuations in local Ca2+ levels. The vesicles responding to these fluctuations are thought to be the same ones that release upon stimulation, albeit potentially triggered by different Ca2+ sensors. This view has been challenged by several recent works, which have suggested that spontaneous release is driven by a separate pool of synaptic vesicles. Numerous articles appeared during the last few years in support of each of these hypotheses, and it has been challenging to bring them into accord. We speculate here on the origins of this controversy, and propose a solution that is related to developmental effects. Constitutive membrane traffic, needed for the biogenesis of vesicles and synapses, is responsible for high levels of spontaneous membrane fusion in young neurons, probably independent of Ca2+. The vesicles releasing spontaneously in such neurons are not related to other synaptic vesicle pools and may represent constitutively releasing vesicles (CRVs rather than bona fide synaptic vesicles. In mature neurons, constitutive traffic is much dampened, and the few remaining spontaneous release events probably represent bona fide spontaneously releasing synaptic vesicles (SRSVs responding to Ca2+ fluctuations, along with a handful of CRVs that participate in synaptic vesicle turnover.

  6. Active hippocampal networks undergo spontaneous synaptic modification.

    Directory of Open Access Journals (Sweden)

    Masako Tsukamoto-Yasui

    Full Text Available The brain is self-writable; as the brain voluntarily adapts itself to a changing environment, the neural circuitry rearranges its functional connectivity by referring to its own activity. How the internal activity modifies synaptic weights is largely unknown, however. Here we report that spontaneous activity causes complex reorganization of synaptic connectivity without any external (or artificial stimuli. Under physiologically relevant ionic conditions, CA3 pyramidal cells in hippocampal slices displayed spontaneous spikes with bistable slow oscillations of membrane potential, alternating between the so-called UP and DOWN states. The generation of slow oscillations did not require fast synaptic transmission, but their patterns were coordinated by local circuit activity. In the course of generating spontaneous activity, individual neurons acquired bidirectional long-lasting synaptic modification. The spontaneous synaptic plasticity depended on a rise in intracellular calcium concentrations of postsynaptic cells, but not on NMDA receptor activity. The direction and amount of the plasticity varied depending on slow oscillation patterns and synapse locations, and thus, they were diverse in a network. Once this global synaptic refinement occurred, the same neurons now displayed different patterns of spontaneous activity, which in turn exhibited different levels of synaptic plasticity. Thus, active networks continuously update their internal states through ongoing synaptic plasticity. With computational simulations, we suggest that with this slow oscillation-induced plasticity, a recurrent network converges on a more specific state, compared to that with spike timing-dependent plasticity alone.

  7. Ectopic pregnancy: a life-threatening gynecological emergency

    Directory of Open Access Journals (Sweden)

    Lawani OL

    2013-08-01

    Full Text Available Osaheni L Lawani, Okechukwu B Anozie, Paul O Ezeonu Department of Obstetrics and Gynecology, Federal Teaching Hospital, Abakaliki, Nigeria Background: Ectopic pregnancy is a life-threatening gynecological emergency, and a significant cause of maternal morbidity and mortality in Nigeria. Objective: The aim of this work was to determine and evaluate the incidence, clinical presentation, risk factors, and management outcomes of ectopic pregnancies at Ebonyi State University Teaching Hospital (EBSUTH in Abakaliki. Methods: This was a retrospective, descriptive study of ectopic pregnancies managed in EBSUTH during the study period (June 1, 2002 to May 31, 2012. The medical records of the patients managed for ectopic pregnancy as well as the total birth record and gynecological admission records during the period under review were retrieved, and data were collected with the aid of data-entry forms designed for this purpose. There were 4,610 gynecological admissions and 9,828 deliveries, with 215 cases of ectopic pregnancies. A total of 205 cases were suitable for analysis after excluding cases with incomplete records. The relevant data collected were analyzed with SPSS version 15.0 for Windows. Results: Ectopic pregnancy constituted 4.5% of all gynecological admissions, and its incidence was 2.1%. The mean age of the patients was 27 ± 2 years, 196 of 205 (95.6% had ruptured ectopic pregnancies, and the remaining nine (4.4% were unruptured. The commonest (166 of 205, 80.0% clinical presentation was abdominal pain, and the commonest (105 of 205, 51.2% identified risk factor was a previous history of induced abortion. Three deaths were recorded, giving a case-fatality rate of 1.4% (three of 205. Conclusion: Ectopic pregnancy is a recognized cause of maternal morbidity and mortality and has remained a reproductive health challenge to Nigerian women, as well as a threat to efforts in achieving the UN's Millennium Development Goal 5 in sub-Saharan Africa

  8. Ectopic pregnancy after two times tubal ligation: a case report

    Directory of Open Access Journals (Sweden)

    Farideh Keypour

    2013-06-01

    Full Text Available Background: Tubal sterilization is the permanent and effective contraception method. This can be performed at any time, but at least half are performed in conjunction with cesarean or vaginal delivery and are termed puerperal. The most complication after tubal ligation is ectopic pregnancy. Ectopic pregnancy is the leading cause of maternal death in first trimester.Case presentation: We present a 33 years old woman gravida5, para4, all normal vaginal delivery, presented with complaints of delayed menstrual period, pelvic pain and spotting. She underwent tubal ligation for two times. For the first time she had puerperal Pomeroy tubal sterilization after third child delivery. Intra uterine pregnancy occurred three years later. One day after vaginal delivery of fourth child, she underwent post partum tubal ligation with the Parkland method. Tubal pregnancy occurred nine months later. Physical examination identified acute abdomen. Pelvic ultrasound showed no gestational sac in uterine cavity. The sac with fetal pole was in right adnexa. Beta-HCG was 2840mIU/ml. She underwent laparotomy. Surgical management included salpingectomy with cornual resection in both sides. The surgery identified Ectopic pregnancy.Conclusion: Any symptoms of pregnancy in a woman after tubal ligation must be investigated; an ectopic pregnancy should be excluded. Ectopic pregnancy must be considered, in any woman with lower abdominal pain, missed period and vaginal bleed-ing. Conception after tubal sterilization can be explained by fistula formation and re-canalization of fallopian tube.

  9. Ectopic Pregnancy After Plan B Emergency Contraceptive Use.

    Science.gov (United States)

    Steele, Brianne Jo; Layman, Kerri

    2016-04-01

    Pregnancy outcomes after emergency contraceptive use has been debated over time, but review of the literature includes mechanisms by which these medications may increase the chance of an ectopic pregnancy. Such cases are infrequently reported, and many emergency providers may not readily consider this possibility when treating patients. This is a case presentation of ectopic pregnancy in a patient who had recently used Plan B (levonorgestrel) emergency contraceptive. She presented with abdominal pain and vaginal spotting, and was evaluated by serum testing and pelvic ultrasound. She was discovered to have a right adnexal pregnancy. She was treated initially with methotrexate, though she ultimately required surgery for definitive treatment. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report aims to bring a unique clinical case to the attention of emergency providers. The goal is to review research on the topic of levonorgestrel use and the incidence of ectopic pregnancies. The mechanism of action of this emergency contraceptive is addressed, and though no definite causal relationship is known between levonorgestrel and ectopic pregnancies, there is a pharmacologic explanation for how this event may occur after use of this medication. Ultimately, the emergency provider will be reminded of the importance of educating the patient on the possible outcomes after its use, including failure of an emergency contraceptive and the potential of ectopic pregnancy. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Ectopic Pregnancy and Emergency Contraceptive Pills: A Systematic Review

    Science.gov (United States)

    Cleland, Kelly; Raymond, Elizabeth; Trussell, James; Cheng, Linan; Zhu, Haoping

    2014-01-01

    Objective To evaluate the existing data to estimate the rate of ectopic pregnancy among emergency contraceptive pill treatment failures. Data Sources Our initial reference list was generated from a 2008 Cochrane review of emergency contraception. In August 2009, we searched Biosys Previews, the Cochrane Database of Systematic Reviews, Medline, Global Health Database, Health Source: Popline, and Wanfang Data (a Chinese database). Methods of Study Selection This study included data from 136 studies which followed a defined population of women treated one time with emergency contraceptive pills (either mifepristone or levonorgestrel), and in which the number and location of pregnancies were ascertained. Results Data from each article were abstracted independently by two reviewers. In the studies of mifepristone, 3 out of 494 (0.6%) pregnancies were ectopic; in the levonorgestrel studies, 3 out of 307 (1%) were ectopic. Conclusion The rate of ectopic pregnancy when treatment with emergency contraceptive pills fails does not exceed the rate observed in the general population. Since emergency contraceptive pills are effective in lowering the risk of pregnancy, their use should reduce the chance that an act of intercourse will result in ectopic pregnancy. PMID:20502299

  11. RECURRENT CORNUAL ECTOPIC PREGNANCY – A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Velayudam DA, Radha Bai Prabhu T, Dipenty Devi L, Meenalochani P, Isha Gutgutia

    2015-10-01

    Full Text Available Cornual ectopic gestation is one of the causes of “Maternal near miss” cases. In the modern era of IVF treatments and better imaging techniques, more number of cases of cornual ectopic pregnancies is being diagnosed and treated both by conservative and radical methods. Here, we report a case of a recurrent cornual ectopic pregnancy in the early second trimester, which was managed by hysterectomy due to uncontrolled haemorrhage. Thirty five year old Mrs. S, Gravida 4, para2, with one previous ectopic pregnancy presented to the obstetric casualty with acute abdominal pain at 15 weeks +2 days of gestation. On vaginal examination, there was right fornicial fullness and both the fornices were tender. Cervical motion tenderness was also present. On review of her previous records, dating scan done at 8 to 9 weeks showed normal intrauterine pregnancy. An emergency scan was carried out which revealed an empty uterine cavity with gestational sac measuring 3.6×4.4×4.6 cms seen outside the uterus just above the fundus with absent cardiac activity. There was evidence of haemoperitoneum, therefore she was diagnosed with recurrent ruptured ectopic pregnancy.

  12. Synaptic plasticity in drug reward circuitry.

    Science.gov (United States)

    Winder, Danny G; Egli, Regula E; Schramm, Nicole L; Matthews, Robert T

    2002-11-01

    Drug addiction is a major public health issue worldwide. The persistence of drug craving coupled with the known recruitment of learning and memory centers in the brain has led investigators to hypothesize that the alterations in glutamatergic synaptic efficacy brought on by synaptic plasticity may play key roles in the addiction process. Here we review the present literature, examining the properties of synaptic plasticity within drug reward circuitry, and the effects that drugs of abuse have on these forms of plasticity. Interestingly, multiple forms of synaptic plasticity can be induced at glutamatergic synapses within the dorsal striatum, its ventral extension the nucleus accumbens, and the ventral tegmental area, and at least some of these forms of plasticity are regulated by behaviorally meaningful administration of cocaine and/or amphetamine. Thus, the present data suggest that regulation of synaptic plasticity in reward circuits is a tractable candidate mechanism underlying aspects of addiction.

  13. Neuromodulation, development and synaptic plasticity.

    Science.gov (United States)

    Foehring, R C; Lorenzon, N M

    1999-03-01

    We discuss parallels in the mechanisms underlying use-dependent synaptic plasticity during development and long-term potentiation (LTP) and long-term depression (LTD) in neocortical synapses. Neuromodulators, such as norepinephrine, serotonin, and acetylcholine have also been implicated in regulating both developmental plasticity and LTP/LTD. There are many potential levels of interaction between neuromodulators and plasticity. Ion channels are substrates for modulation in many cell types. We discuss examples of modulation of voltage-gated Ca2+ channels and Ca(2+)-dependent K+ channels and the consequences for neocortical pyramidal cell firing behaviour. At the time when developmental plasticity is most evident in rat cortex, the substrate for modulation is changing as the densities and relative proportions of various ion channels types are altered during ontogeny. We discuss examples of changes in K+ and Ca2+ channels and the consequence for modulation of neuronal activity.

  14. Elementary properties of Ca(2+) channels and their influence on multivesicular release and phase-locking at auditory hair cell ribbon synapses.

    Science.gov (United States)

    Magistretti, Jacopo; Spaiardi, Paolo; Johnson, Stuart L; Masetto, Sergio

    2015-01-01

    Voltage-gated calcium (Cav1.3) channels in mammalian inner hair cells (IHCs) open in response to sound and the resulting Ca(2+) entry triggers the release of the neurotransmitter glutamate onto afferent terminals. At low to mid sound frequencies cell depolarization follows the sound sinusoid and pulses of transmitter release from the hair cell generate excitatory postsynaptic currents (EPSCs) in the afferent fiber that translate into a phase-locked pattern of action potential activity. The present article summarizes our current understanding on the elementary properties of single IHC Ca(2+) channels, and how these could have functional implications for certain, poorly understood, features of synaptic transmission at auditory hair cell ribbon synapses.

  15. Elementary properties of Ca2+ channels and their influence on multivesicular release and phase-locking at auditory hair cell ribbon synapses

    Science.gov (United States)

    Magistretti, Jacopo; Spaiardi, Paolo; Johnson, Stuart L.; Masetto, Sergio

    2015-01-01

    Voltage-gated calcium (Cav1.3) channels in mammalian inner hair cells (IHCs) open in response to sound and the resulting Ca2+ entry triggers the release of the neurotransmitter glutamate onto afferent terminals. At low to mid sound frequencies cell depolarization follows the sound sinusoid and pulses of transmitter release from the hair cell generate excitatory postsynaptic currents (EPSCs) in the afferent fiber that translate into a phase-locked pattern of action potential activity. The present article summarizes our current understanding on the elementary properties of single IHC Ca2+ channels, and how these could have functional implications for certain, poorly understood, features of synaptic transmission at auditory hair cell ribbon synapses. PMID:25904847

  16. Synchronous Ectopic Pancreases in the Cardia and Antrum of the Stomach: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Yie, Mi yeon; Kim, Min Jeong; Lee, In Jae; Yang, Dae Hyun; Jun, Sun Young; Min, Kwang seon [Hallym University Medical Center, Anyang (Korea, Republic of); Jang, Kyung Mi [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2010-04-15

    Ectopic pancreas is most commonly found in the antrum of the stomach, duodenum, or proximal jejunum. Rarely ectopic pancreas in the proximal stomach has been reported. Moreover, the coexistence of two ectopic pancreases at gastric cardia and antrum in a patient has not been reported. Ectopic pancreas usually appears as a submucosal mass, and it is difficult to differentiate between ectopic pancreas and other common submucosal tumors, such as a gastrointestinal stromal tumor (GIST) or leiomyoma. Here, we present a case of the coexistence of two ectopic pancreases at cardia and antrum of the stomach in a 60-year-old man, which was preoperatively misdiagnosed as GIST

  17. Synchronous Ectopic Pancreases in the Cardia and Antrum of the Stomach: A Case Report

    International Nuclear Information System (INIS)

    Yie, Mi yeon; Kim, Min Jeong; Lee, In Jae; Yang, Dae Hyun; Jun, Sun Young; Min, Kwang seon; Jang, Kyung Mi

    2010-01-01

    Ectopic pancreas is most commonly found in the antrum of the stomach, duodenum, or proximal jejunum. Rarely ectopic pancreas in the proximal stomach has been reported. Moreover, the coexistence of two ectopic pancreases at gastric cardia and antrum in a patient has not been reported. Ectopic pancreas usually appears as a submucosal mass, and it is difficult to differentiate between ectopic pancreas and other common submucosal tumors, such as a gastrointestinal stromal tumor (GIST) or leiomyoma. Here, we present a case of the coexistence of two ectopic pancreases at cardia and antrum of the stomach in a 60-year-old man, which was preoperatively misdiagnosed as GIST

  18. Synaptic transmission modulates while non-synaptic processes govern the transition from pre-ictal to seizure activity in vitro

    OpenAIRE

    Jefferys, John; Fox, John; Jiruska, Premysl; Kronberg, Greg; Miranda, Dolores; Ruiz-Nuño, Ana; Bikson, Marom

    2018-01-01

    It is well established that non-synaptic mechanisms can generate electrographic seizures after blockade of synaptic function. We investigated the interaction of intact synaptic activity with non-synaptic mechanisms in the isolated CA1 region of rat hippocampal slices using the 'elevated-K+' model of epilepsy. Elevated K+ ictal bursts share waveform features with other models of electrographic seizures, including non-synaptic models where chemical synaptic transmission is suppressed, such as t...

  19. Evidence-based management of non-tubal ectopic pregnancies.

    Science.gov (United States)

    Alalade, Aderemi Olaoluwa; Smith, Fredrick John Ennis; Kendall, Charlotte Emma; Odejinmi, Funlayo

    2017-11-01

    Recent advances in ultrasonography and the use of other modalities including magnetic resonance imaging scans have led to the early and more accurate diagnosis of non-tubal ectopic pregnancies (NTE). As a result, the management of these pregnancies has evolved. This article addresses the management options currently available for NTE. While surgical management remains the mainstay of treatment for ovarian, abdominal and cornual ectopics, there is growing evidence that some of these can be managed medically. Many authors have utilised a combination of medical and surgical approaches in the management of cervical and caesarean section (CS) scar ectopic pregnancies with good outcome. The availability of dedicated early pregnancy units has further improved diagnosis and more importantly the follow-up care for these patients. The rarity of cases and the difficulty of ethically organising randomised trials for NTE remain a problem in formulating consistent pathways for optimum management of women with NTE.

  20. Spontaneous unilateral Twin Ectopic Pregnancy: A case report

    Directory of Open Access Journals (Sweden)

    هادی اریا منش

    2017-03-01

    Full Text Available Abstract Aim & Objective: Twin pregnancy in the tube is a few and due to more frequent use of ovulatory medicine and increased maternal mortality rate. In this article, we report a case of  untitled twin ectopic pregnancy. Case study: The pregnant women was a 28 year-old  to had  a  history infertility, PCOD, Abortion and cortege,   too have one 5 years girl by CS and  Mild cramp pain in both abdominal lower quadrants and metroreghia . That have not treatment by projection. The ultra-sonography showed a twin pregnancy uterus with a moderate amount of fluid in pelvic cavity was seen. And do salpanjectimy surgery. Conclusion:  We report one Untitled Spontaneous Twin Ectopic Pregnancy,  is necessary any pregnant woman with  positive BhCG and metrorhoghia must be considered for Ectopic pregnancy. To decrease maternal mortality rate. Key words:

  1. Laparoscopic Surgery for the Treatment of Ectopic Pregnancy

    Directory of Open Access Journals (Sweden)

    Hulusi B ZEYNELOGLU

    2005-09-01

    Full Text Available OBJECTIVE: To evaluate the outcomes of laparoscopic surgery for the treatment of ectopic pregnancy Design: 43 women with ectopic pregnancy who underwent laparoscopic surgery in our department between 1996 and 2005 were included in this study.\tSetting: Department of Obstetrics and Gynecology, School of Medicine, Baskent University, Ankara Patients: 43 women with ectopic pregnancy who underwent laparoscopic surgery Interventions: Laparoscopic surgery was performed the treatment of ectopic pregnancy Main Outcome Measures: Patients characteristics such as age, parity, gestational age at the time of diagnosis, symptoms, preoperative and postoperative serum _-hCG and hemoglobin levels, sonographic findings, type of laparoscopic surgery, blood transfusion, additional treatments, endometrial sampling and postoperative fertility status were recorded. The size and the location of myomas were obtained from the surgeon’s findings in the operative note. Preoperative and postoperative hemoglobin values, change in hemoglobin values, hemorrhage, blood transfusion, postoperative fewer, duration of operation and length of postoperative hospital stay were the main outcomes. RESULTS: Forty-three women with ectopic pregnancy who underwent laparoscopic surgery were included in this study. Patients were submitted usually with pelvic pain and abnormal vaginal bleeding. Adnexal mass and hemoperitoneum were seen by sonographic evaluation. Ampuller pregnancy was the most common. Most of patients had conservative surgery and 38% of patients underwent salpingectomy. 12 patient had blood transfusion and two ones underwent re-laparoscopy. After treatment 5 intrauterine pregnancies were occurred. Endometrial samplings usually defined as decidual en Aria stella reactions. Serum _-hCG levels were in normal range at the end of the month after the laparoscopy. CONCLUSION: In conclusion according to these findings, laparoscopic surgery remains the definitive and universal

  2. Random anisotropy studies in amorphous Co-Tb ribbons

    International Nuclear Information System (INIS)

    Hassanain, N.; Berrada, A.; Lassri, H.; Krishnan, R.

    1995-01-01

    Amorphous Co 1-x Tb x ribbons with x=0.45, 0.55 and 0.65 have been prepared by melt spinning technique. Magnetization measurements were carried out at 4.2 K, under magnetic fields up to 150 kOe. The Co moment is found to be very small and the Tb moment is 7.15μ B at 4.2 K, which indicates a speromagnetic spin structure. Using Chudnovsky's theory we have extracted some fundamental magnetic parameters. ((orig.))

  3. Random anisotropy studies in amorphous CoTb ribbons

    Science.gov (United States)

    Hassanain, N.; Berrada, A.; Lassri, H.; Krishnan, R.

    1995-02-01

    Amorphous Co 1- xTb x ribbons with x = 0.45, 0.55 and 0.65 have been prepared by melt spinning technique. Magnetization measurements were carried out at 4.2 K, under magnetic fields up to 150 kOe. The Co moment is found to be very small and the Tb moment is 7.15 μB at 4.2 K, which indicates a speromagnetic spin structure. Using Chudnovsky's theory we have extracted some fundamental magnetic parameters.

  4. The mechanics of Ribbons and Möbius bands

    CERN Document Server

    Fried, Eliot

    2016-01-01

    Recent developments in biology and nanotechnology have stimulated a rapidly growing interest in the mechanics of thin, flexible ribbons and Mobius bands. This edited volume contains English translations of four seminal papers on this topic, all originally written in German; of these, Michael A. Sadowsky published the first in 1929, followed by two others in 1930, and Walter Wunderlich published the last in 1962. The volume also contains invited, peer-reviewed, original research articles on related topics. Previously published in the Journal of Elasticity, Volume 119, Issue 1-2, 2015.

  5. Magnetoband structures of AB-stacked zigzag nanographite ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.P.; Chiu, C.W.; Shyu, F.L.; Chen, R.B.; Lin, M.F

    2002-12-30

    Magnetoband structures of AB-stacked zigzag nanographite ribbons are studied by the tight-binding model. The magnetic field changes band width, energy space, and energy dispersions (the produce of Landau subbands and Landau levels). It causes many zero energy points. Such points and corresponding localized states are studied in detail. There are certain important differences between localized states and edge states. Oscillation period of Landau subbands are determined by these points. The interribbon interactions also affect magnetoband structures, such as energy dispersions, band width, oscillation period of Landau subbands, and flux dependence of Hofstadter butterflies.

  6. Ectopic Intratracheal Thyroid: A Rare Cause of Airway Obstruction

    Directory of Open Access Journals (Sweden)

    Waheed Rahman

    2018-01-01

    Full Text Available Ectopic intratracheal thyroid tissue (EITT is a rare abnormality with only limited cases reported so far. The presenting symptoms can be very similar to those of bronchial asthma. We discuss the case of a 29-year-old man with subglottic ectopic thyroid, with a history of thyroid surgery for goiter, which has been managed with laser-assisted endoscopic approach. We have also included presenting symptoms, pathophysiology, diagnosis, and management of EITT. We aim to include EITT in the differentials of airway obstruction, particularly in those patients who have goiter or previous thyroid surgeries.

  7. MDCT findings of right circumaortic renal vein with ectopic kidney

    International Nuclear Information System (INIS)

    Kim, Min Kyun; Ku, Young Mi; Chun, Chang Woo; Lee, Su Lim

    2013-01-01

    Anomalies of renal vasculature combined with ectopic kidneys were found on a multi-detector CT scan. Knowledge of renal vascular variation is very important for surgical exploration, radiologic intervention and staging for urologic cancer. We present an extremely rare case of a right circumaortic renal vein combined with a right ectopic kidney. The right kidney was located at the level between the third and fifth lumbar vertebra. The right circumaortic renal vein crossed the aorta and returned to the inferior vena cava behind the aorta.

  8. A case of ectopic intraabdominal fascioliasis presented with acute abdomen.

    Science.gov (United States)

    Tanir, Gönül; Karaman, Ayşe; Tüfekçı, Sehra Birgül; Erdoğan, Duygu; Tuygun, Nilden; Ozkan, Ayşegül Taylan

    2011-06-01

    Human fascioliasis with Fasciola species occurs worldwide and is most common among rural people who tend sheep and eat uncooked water vegetables, particularly watercress. The natural history of the acute phase begins with ingestion of metacercariae encysted on various kinds of aquatic vegetation such as watercress. Fascioliasis primarily involves the liver, bile ducts, gallbladder, and occasionally ectopic sites. We describe herein a case of ectopic fascioliasis. This uncommon form of disease was peritonitis; both visceral and parietal peritoneal layers were affected with the formation of multiple nodules and ascites.

  9. Burst activity and ultrafast activation kinetics of CaV1.3 Ca²⁺ channels support presynaptic activity in adult gerbil hair cell ribbon synapses.

    Science.gov (United States)

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Knipper, Marlies; Holley, Matthew C; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2013-08-15

    Auditory information transfer to afferent neurons relies on precise triggering of neurotransmitter release at the inner hair cell (IHC) ribbon synapses by Ca²⁺ entry through CaV1.3 Ca²⁺ channels. Despite the crucial role of CaV1.3 Ca²⁺ channels in governing synaptic vesicle fusion, their elementary properties in adult mammals remain unknown. Using near-physiological recording conditions we investigated Ca²⁺ channel activity in adult gerbil IHCs. We found that Ca²⁺ channels are partially active at the IHC resting membrane potential (-60 mV). At -20 mV, the large majority (>70%) of Ca²⁺ channel first openings occurred with an estimated delay of about 50 μs in physiological conditions, with a mean open time of 0.5 ms. Similar to other ribbon synapses, Ca²⁺ channels in IHCs showed a low mean open probability (0.21 at -20 mV), but this increased significantly (up to 0.91) when Ca²⁺ channel activity switched to a bursting modality. We propose that IHC Ca²⁺ channels are sufficiently rapid to transmit fast signals of sound onset and support phase-locking. Short-latency Ca²⁺ channel opening coupled to multivesicular release would ensure precise and reliable signal transmission at the IHC ribbon synapse.

  10. Universal method for opnimal design main structural assemblies of steel structures stationary conveyor with hanging ribbon

    Directory of Open Access Journals (Sweden)

    Boslovyak P.V.

    2015-10-01

    Full Text Available The technique and the detailed algorithm for optimal design of steel structures hospitaltion of the conveyor with hang-ing ribbon. Developed a universal objective function together with the system-limited-subject to limits of main components of steel structures of stationary conveyor with hanging ribbon.

  11. The sandwich domain structure in a Fe-based amorphous ribbon with uniaxial magnetic anisotropy

    International Nuclear Information System (INIS)

    Zhmetko, D.N.; Matsura, A.V.; Troschenkov, Y.N.; Seidametov, S.V.

    2011-01-01

    The formation and motion of two domain walls parallel to the ribbon surface are discovered during its dynamic magnetic reversal. The domain walls form near by the middle plane of a ribbon and move to its opposite main surfaces with different velocities.

  12. Test results of Nb3Sn ribbons for the Princeton D coil test program

    International Nuclear Information System (INIS)

    Kaugerts, J.; File, J.; Willard, J.W.

    1974-10-01

    A previously described D coil test program was modified. Details of a smaller Nb 3 Sn D coil test program are described. Cusp coil tests were made with several Nb 3 Sn composite ribbons. Measurements of both the quench and recovery currents as a function of magnetic field component perpendicular to the wide edge of the ribbon are presented. (auth)

  13. 77 FR 32938 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2012-06-04

    ... ribbons subject to the order include all narrow woven fabrics, tapes, and labels that fall within this... the manufacture of typewriter or printer ribbons; (5) Narrow woven labels and apparel tapes, cut-to... 1994 U.S.C.C.A.N. 4040, 4198-99. Furthermore, ``affirmative evidence of bad faith on the part of a...

  14. The ribbon microphone: A teaching aid for low frequency electromagnetic education

    CSIR Research Space (South Africa)

    Van Wyk, Marius S

    2017-09-01

    Full Text Available The ribbon microphone lends itself as a good example to use for education of multi-physics computer modeling and simulation. The value of the ribbon microphone as teaching aid can be extended by adding a transformer and electronic amplifier...

  15. 76 FR 38648 - Availability of the Geothermal Technologies Program Blue Ribbon Panel Report and Request for...

    Science.gov (United States)

    2011-07-01

    ....S. has lagged that of solar and wind energy. The purpose of the Blue Ribbon Panel meeting was to... Geothermal Technologies Program Blue Ribbon Panel Report and Request for Public Comment AGENCY: Office of... Panel (the Panel) on March 22/23, 2011 in Albuquerque, New Mexico for a guided discussion on the future...

  16. Metallurgical characterization of melt-spun ribbons of U-5.4 wt%Nb alloy

    Science.gov (United States)

    Ma, Rong; Ren, Zhiyong; Tang, Qingfu; Chen, Dong; Liu, Tingyi; Su, Bin; Wang, Zhenhong; Luo, Chao

    2018-06-01

    The microstructures and micro-mechanical properties of the melt-spun ribbons of U-5.4 wt%Nb alloy were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and nanoindentation. Observed variations in microstructures and properties are related to the changes in ribbon thicknesses and cooling rates. The microstructures of the melt-spun ribbon consist of fine-scale columnar grains (∼1 μm) adjacent to the chill surface and coarse cellular grains in the remainder of the ribbon. In addition, the formation of inclusions in the ribbon is suppressed kinetically due to the high cooling rate during melt spinning. Compared with the water-quenched specimen prepared by traditional gravity casting and solution heat treatment, the elastic modulus values of the U-5.4 wt%Nb alloy were examined to vary with grain size and exhibited diverse energy dissipation capacities.

  17. Electronic properties and mechanical strength of β-phosphorene nano-ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Swaroop, Ram; Bhatia, Pradeep; Kumar, Ashok, E-mail: ashok@cup.ac.in [Centre for Physical Sciences, School of Basic and Applied Sciences, Central University of Punjab, Bathinda, India-151001 (India)

    2016-05-06

    We have performed first principles calculations to find out the effect of mechanical strain on the electronic properties of zig-zag edged nano ribbons of β-phosphorene. It is found that electronic band-gap get opened-up to 2.61 eV by passivation of the edges of ribbons. Similarly, the mechanical strength is found to be increase from 1.75 GPa to 2.65 GPa on going from unpassivated nano ribbons to passivated ones along with the 2% increase in ultimate tensile strain. The band-gap value of passivated ribbon gets decreased to 0.43 eV on applying strain up to which the ribbon does not break. These tunable properties of β-phospherene with passivation with H-atom and applying mechanical strain offer its use in tunable nano electronics.

  18. Mena–GRASP65 interaction couples actin polymerization to Golgi ribbon linking

    Science.gov (United States)

    Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

    2016-01-01

    In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. PMID:26538023

  19. 3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?

    Science.gov (United States)

    Verdini, Andrea; Grappin, Roland; Alexandrova, Olga; Lion, Sonny

    2018-01-01

    We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method allows nonaxisymmetric structures. These results are probably contaminated by the wind expansion that introduces another symmetry axis, namely, the radial direction, as indicated by recent numerical simulations. These simulations also show that while the expansion is strong, the principal fluctuations are in the plane perpendicular to the radial direction. Using this property, we separate 11 yr of Wind spacecraft data into two subsets characterized by strong and weak expansion and determine the corresponding turbulence anisotropy. Under strong expansion, the small-scale anisotropy is consistent with the Goldreich & Sridhar critical balance. As in previous works, when the radial symmetry axis is not eliminated, the turbulent structures are field-aligned tubes. Under weak expansion, we find 3D anisotropy predicted by the Boldyrev model, that is, turbulent structures are ribbons and not tubes. However, the very basis of the Boldyrev phenomenology, namely, a cross-helicity increasing at small scales, is not observed in the solar wind: the origin of the ribbon formation is unknown.

  20. Thermal Conductivity of Graphene-hBN Superlattice Ribbons.

    Science.gov (United States)

    Felix, Isaac M; Pereira, Luiz Felipe C

    2018-02-09

    Superlattices are ideal model systems for the realization and understanding of coherent (wave-like) and incoherent (particle-like) phonon thermal transport. Single layer heterostructures of graphene and hexagonal boron nitride have been produced recently with sharp edges and controlled domain sizes. In this study we employ nonequilibrium molecular dynamics simulations to investigate the thermal conductivity of superlattice nanoribbons with equal-sized domains of graphene and hexagonal boron nitride. We analyze the dependence of the conductivity with the domain sizes, and with the total length of the ribbons. We determine that the thermal conductivity reaches a minimum value of 89 W m -1 K -1 for ribbons with a superlattice period of 3.43 nm. The effective phonon mean free path is also determined and shows a minimum value of 32 nm for the same superlattice period. Our results also reveal that a crossover from coherent to incoherent phonon transport is present at room temperature for BNC nanoribbons, as the superlattice period becomes comparable to the phonon coherence length. Analyzing phonon populations relative to the smallest superlattice period, we attribute the minimum thermal conductivity to a reduction in the population of flexural phonons when the superlattice period equals 3.43 nm. The ability to manipulate thermal conductivity using superlattice-based two-dimensional materials, such as graphene-hBN nanoribbons, opens up opportunities for application in future nanostructured thermoelectric devices.

  1. Oxidation behaviour of ribbon shape carbon fibers and their composites

    International Nuclear Information System (INIS)

    Manocha, L.M.; Warrier, Ashish; Manocha, S.; Edie, D.D.; Ogale, A.A.

    2006-01-01

    Carbon fibers, though important constituent as reinforcements for high performance carbon/carbon composites, are shadowed by their oxidation in air at temperatures beginning 450 deg. C. Owing to tailorable properties of carbon fibers, efforts are underway to explore structural modification possibilities to improve the oxidation resistance of the fibers and their composites. The pitch based ribbon shape carbon fibers are found to have highly preferential oriented graphitic structure resulting in high mechanical properties and thermal conductivity. In the present work oxidation behaviour of ribbon shape carbon fibers and their composites heat treated to 1000-2700 deg. C has been studied. SEM examination of these composites exhibits development of graphitic texture and ordering within the fibers with increase in heat treatment temperature. Oxidation studies made by thermogravimetric analysis in air show that matrix has faster rate of oxidation and in the initial stages the matrix gets oxidized at faster rate with slower rate of oxidation of the fibers depending on processing conditions of fibers and composites

  2. 75 FR 41808 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Final Determination...

    Science.gov (United States)

    2010-07-19

    ... Ribbon Company, Inc. (``Petitioner''); Yama; and Yangzhou Bestpak Gifts & Crafts Co., Ltd. (``Bestpak... liquid petroleum gas from the supplier to Yama's factory.\\10\\ \\10\\ See Final Analysis Memorandum for Yama... limited to gift bags, gift boxes and/ or other types of ribbon. Narrow woven ribbons subject to the...

  3. Bilateral tubal ectopic pregnancies: A report of two cases | Eze ...

    African Journals Online (AJOL)

    Bilateral tubal ectopic pregnancies are rare occurrences. Two recently managed cases are discussed. The first was a single, sexually active 23-year-old nullipara with family history of twinning who presented with eight weeks amenorrhea, positive pregnancy test, lower abdominal discomfort and other clinical and ultrasound ...

  4. Ectopic Splenic Tissue in the Testis: A Case Report

    African Journals Online (AJOL)

    Ectopic SplENic tiSSUE iN thE tEStiS associated with bilateral cryptorchidism and hypospadias4. Brasch et al. reported a case involving the right testis5. Ultrasonography, scintigraphy (with technetium-99m) and single positron emission computerized tomography are considered the best diagnostic tools for this condition2,3.

  5. Early Ectopic Recurrence of Craniopharyngioma in the Cerebellopontine Angle.

    Science.gov (United States)

    Mahdi, Mohamad-Motaz Al; Krauss, Joachim K; Nakamura, Makoto; Brandis, Almuth; Hong, Bujung

    2018-01-01

    Ectopic recurrence of craniopharyngioma in the cerebellopontine angle after surgical resection of a suprasellar craniopharyngioma is rare. Thus, only 5 cases were reported with a delay ranging between 4 and 26 years after removal of the primary tumor. We report a unique case of ectopic recurrence of craniopharyngioma in the cerebellopontine angle, which occurred at only 4 months after surgical resection of the primary tumor. A 24-year-old man underwent resection of a suprasellar craniopharyngioma via a right pterional approach four months earlier. During follow-up, cerebral magnetic resonance imaging (MRI) showed a round homogeneous contrast-enhancing tumor in the right cerebellopontine angle with neither relation to the internal auditory canal nor to the dura mater. After microsurgical resection, histopathological findings revealed ectopic recurrence of craniopharyngioma with similar tumors like the primary tumor. Although infrequent, craniopharyngioma may disseminate via the cerebrospinal fluid during surgical resection and grow in an ectopic place. Early follow-up and MRI scan following resection of a craniopharyngioma is recommended.

  6. Retrospective review of the medical management of ectopic ...

    African Journals Online (AJOL)

    Medical management of ectopic pregnancies is a safe and effective management option, as proven by international data, but at Tygerberg Hospital the safety of this treatment modality cannot be guaranteed because of poor follow-up. Improvement in patient selection with consideration of predictors of success and thorough ...

  7. Ectopic ACTH syndrome: a clinical challenge | Tsabedze | Journal of ...

    African Journals Online (AJOL)

    A patient was managed in our endocrinology unit with ectopic Cushing's syndrome from an adrenocorticotropic hormoneproducing neuroendocrine carcinoma of the anal canal. There was limited response to standard therapy, which made it difficult to correct the electrolyte and metabolic derangements associated with the ...

  8. Damage-induced ectopic recombination in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Kupiec, M; Steinlauf, R

    1997-06-09

    Mitotic recombination in the yeast Saccharomyces cerevisiae is induced when cells are irradiated with UV or X-rays, reflecting the efficient repair of damage by recombinational repair mechanisms. We have used multiply marked haploid strains that allow the simultaneous detection of several types of ectopic recombination events. We show that inter-chromosomal ectopic conversion of lys2 heteroalleles and, to a lesser extent, direct repeat recombination (DRR) between non-tandem repeats, are increased by DNA-damaging agents; in contrast, ectopic recombination of the naturally occurring Ty element is not induced. We have tested several hypotheses that could explain the preferential lack of induction of Ty recombination by DNA-damaging agents. We have found that the lack of induction cannot be explained by a cell cycle control or by an effect of the mating-type genes. We also found no role for the flanking long terminal repeats (LTRs) of the Ty in preventing the induction. Ectopic conversion, DRR, and forward mutation of artificial repeats show different kinetics of induction at various positions of the cell cycle, reflecting different mechanisms of recombination. We discuss the mechanistic and evolutionary aspects of these results.

  9. Junctional ectopic tachycardia following repair of congenital heart ...

    African Journals Online (AJOL)

    Background: Postoperative junctional ectopic tachycardia (JET) is a rare and transient phenomenon occurring after repair of congenital heart defects. Report on this arrhythmia in the subregion is rare. We set out to determine the incidence of this arrhythmia and review the treatment and outcomes of treatment in our centre.

  10. Cervical ectopic pregnancy: Mersilene tape in surgical management

    African Journals Online (AJOL)

    2 Division of Obstetrics and Gynaecology, Mediclinic Hospital, Nelspruit, Mpumalanga, South Africa. Corresponding author: A A ... case of cerv ical ectopic pregnancy that was managed using cervical cerclage with Mersilene tape as an interven tion to reduce intraoperative haemorrhage during evacuation. Case report.

  11. Transvaginal echography in the diagnose of the ectopic pregnancy

    International Nuclear Information System (INIS)

    Betancourt, Claudia; Rivera, Humberto

    1993-01-01

    The ultrasound findings in 21 patients with confirmed ectopic pregnancy were reviewed. The inclusion criteria were those of anatomopathologic confirmation of this diagnosis. All patients were examined with trans-vaginal ultrasound. The most important echographic finding was and an adnexial mass, of mix nature, associated with fluid at the posterior cul-de-sac, in 86% of our patients

  12. Molecular mechanisms of synaptic remodeling in alcoholism.

    Science.gov (United States)

    Kyzar, Evan J; Pandey, Subhash C

    2015-08-05

    Alcohol use and alcohol addiction represent dysfunctional brain circuits resulting from neuroadaptive changes during protracted alcohol exposure and its withdrawal. Alcohol exerts a potent effect on synaptic plasticity and dendritic spine formation in specific brain regions, providing a neuroanatomical substrate for the pathophysiology of alcoholism. Epigenetics has recently emerged as a critical regulator of gene expression and synaptic plasticity-related events in the brain. Alcohol exposure and withdrawal induce changes in crucial epigenetic processes in the emotional brain circuitry (amygdala) that may be relevant to the negative affective state defined as the "dark side" of addiction. Here, we review the literature concerning synaptic plasticity and epigenetics, with a particular focus on molecular events related to dendritic remodeling during alcohol abuse and alcoholism. Targeting epigenetic processes that modulate synaptic plasticity may yield novel treatments for alcoholism. Published by Elsevier Ireland Ltd.

  13. Primary Follicular Carcinoma Arising in Ectopic Thyroid Tissue of the Lateral Neck: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Se Won; Park, Dong Woo; Kim, Soo Yeon; Hahm, Chang Kok; Lee, Young Jun; Lee, Seung Ro; Pyo, Ju Yeon; Oh, Young Ha; Park, Yong Wook [Hanyang University College of Medicine, Guri Hospital, Guri (Korea, Republic of)

    2010-11-15

    Ectopic thyroid tissue in the lateral neck is an uncommon congenital anomaly, and the occurrence of primary follicular carcinoma in this ectopic thyroid tissue is very rare. We report here on such a case of follicular carcinoma arising in ectopic thyroid tissue of the left lateral neck without any evidence of primary carcinoma in the original thyroid gland

  14. Primary Follicular Carcinoma Arising in Ectopic Thyroid Tissue of the Lateral Neck: A Case Report

    International Nuclear Information System (INIS)

    Oh, Se Won; Park, Dong Woo; Kim, Soo Yeon; Hahm, Chang Kok; Lee, Young Jun; Lee, Seung Ro; Pyo, Ju Yeon; Oh, Young Ha; Park, Yong Wook

    2010-01-01

    Ectopic thyroid tissue in the lateral neck is an uncommon congenital anomaly, and the occurrence of primary follicular carcinoma in this ectopic thyroid tissue is very rare. We report here on such a case of follicular carcinoma arising in ectopic thyroid tissue of the left lateral neck without any evidence of primary carcinoma in the original thyroid gland

  15. Lateral regulation of synaptic transmission by astrocytes.

    Science.gov (United States)

    Covelo, A; Araque, A

    2016-05-26

    Fifteen years ago the concept of the "tripartite synapse" was proposed to conceptualize the functional view that astrocytes are integral elements of synapses. The signaling exchange between astrocytes and neurons within the tripartite synapse results in the synaptic regulation of synaptic transmission and plasticity through an autocrine form of communication. However, recent evidence indicates that the astrocyte synaptic regulation is not restricted to the active tripartite synapse but can be manifested through astrocyte signaling at synapses relatively distant from active synapses, a process termed lateral astrocyte synaptic regulation. This phenomenon resembles the classical heterosynaptic modulation but is mechanistically different because it involves astrocytes and its properties critically depend on the morphological and functional features of astrocytes. Therefore, the functional concept of the tripartite synapse as a fundamental unit must be expanded to include the interaction between tripartite synapses. Through lateral synaptic regulation, astrocytes serve as an active processing bridge for synaptic interaction and crosstalk between synapses with no direct neuronal connectivity, supporting the idea that neural network function results from the coordinated activity of astrocytes and neurons. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Dynamics of sandwich domain structure in Co-based amorphous ribbons with helical magnetic anisotropy: Part I

    International Nuclear Information System (INIS)

    Zhmetko, D.N.; Zhmetko, S.D.

    2009-01-01

    The distribution of axes of easy magnetization close to a homogeneous distribution is revealed in each half-thickness of a ribbon after annealing it in a helical magnetic field. The transition from magnetic reversal of a ribbon by the displacement of two domain walls formed near a middle plane of a ribbon to magnetic reversal of a ribbon by displacement of two domain walls formed near to the main surfaces of a ribbon is found out during each half-period of a magnetic reversal.

  17. Risk factors for ectopic pregnancy in Germany: a retrospective study of 100,197 patients

    Directory of Open Access Journals (Sweden)

    Jacob, Louis

    2017-12-01

    Full Text Available Aim: The goal of this study was to identify potential risk factors for ectopic pregnancy in women followed in German gynecological practices.Methods: The present study included pregnant women diagnosed with ectopic pregnancy and pregnant women without ectopic pregnancy followed in 262 gynecological practices between January 2012 and December 2016. The effects of demographic and clinical variables on the risk of developing ectopic pregnancy were estimated using a multivariate logistic regression model. Results: This study included 3,003 women with ectopic pregnancy and 97,194 women without ectopic pregnancy. The mean age was 31.4 years (SD=5.9 years in ectopic pregnancy patients and 31.1 years (SD=5.6 years in non-ectopic pregnancy patients. Women aged 36–40 (OR=1.12 and 41–45 years (OR=1.46 were at a higher risk of ectopic pregnancy than women aged 31–35 years. Prior ectopic pregnancy was strongly associated with a risk of recurring ectopic pregnancy (OR=8.17. Prior genital surgery (OR=2.67, endometriosis (OR=1.51, and eight other gynecological diseases were also positively associated with ectopic pregnancy (ORs ranging from 1.19 to 2.06. Finally, there was a 1.80-fold increase in women previously diagnosed with psychiatric disorders.Conclusions: Prior ectopic pregnancy and prior genital surgery were strongly associated with ectopic pregnancy in women followed in German gynecological practices. Psychiatric diseases had an additional impact on the risk of ectopic pregnancy.

  18. Nanocrystallization in amorphous Fe40Ni40(Si+B)19Mo1-2 ribbons

    International Nuclear Information System (INIS)

    Saiseng, S.; Winotai, P.; Nilpairuch, S.; Limsuwan, P.; Tang, I.M.

    2004-01-01

    Cut Fe 40 Ni 40 (Si+B) 19 Mo 1-2 ribbons were annealed for 2 h at various temperatures between 350 deg. C and 600 deg. C. XRD and Mossbauer effect spectroscopy (ME) measurements were then performed on all of the ribbons. The magnetic properties of several ribbons were measured using a vibrating sample magnetometer (VSM). A differential thermal analysis scan (over the range 20-800 deg. C) of the as-cast ribbon showed two phase transitions; the first at 454 deg. C and the second at 525 deg. C. Both the XRD and ME spectra of the as cast, the 350 deg. C and 400 deg. C annealed ribbons showed that they were amorphous. The ME spectra of the 450 deg. C, 475 deg. C and 500 deg. C annealed ribbons showed that these ribbons contained α-Fe, α-Fe(Si) and t-Fe 2 B nanocrystallites. For the ribbons annealed above 550 deg. C, crystallites of t-Fe 2 B, t-Fe 3 B, t-Fe 5 SiB 2 and FCC-FeNi appeared, with the α-Fe and α-Fe(Si) crystallites disappearing. The sextets of all of the Fe compounds appeared in the ME spectra of the 525 deg. C annealed ribbon. The VSM measurements supported the picture of a two-stage phase transitions; amorphous phase→a nanocrystalline phase (Fe-containing nanocrystallites in an amorphous matrix) at 454 deg. C and then a second transition, the nanocrystalline phase→a disordered alloy containing Fe-B and Fe-Ni crystallites at 525 deg. C

  19. Small Scales Structure of MHD Turbulence, Tubes or Ribbons?

    Science.gov (United States)

    Verdini, A.; Grappin, R.; Alexandrova, O.; Lion, S.

    2017-12-01

    Observations in the solar wind indicate that turbulent eddies change their anisotropy with scales [1]. At large scales eddies are elongated in direction perpendicular to the mean-field axis. This is the result of solar wind expansion that affects both the anisotropy and single-spacecraft measurments [2,3]. At small scales one recovers the anisotropy expected in strong MHD turbulence and constrained by the so-called critical balance: eddies are elongated along the mean-field axis. However, the actual eddy shape is intermediate between tubes and ribbons, preventing us to discriminate between two concurrent theories that predict 2D axysimmetric anisotropy [4] or full 3D anisotropy [5]. We analyse 10 years of WIND data and apply a numerically-derived criterion to select intervals in which solar wind expansion is expected to be negligible. By computing the anisotropy of structure functions with respect to the local mean field we obtain for the first time scaling relations that are in agreement with full 3D anisotropy, i.e. ribbons-like structures. However, we cannot obtain the expected scaling relations for the alignment angle which, according to the theory, is physically responsible for the departure from axisymmetry. In addition, a further change of anisotropy occurs well above the proton scales. We discuss the implication of our findings and how numerical simulations can help interpreting the observed spectral anisotropy. [1] Chen et al., ApJ, 768:120, 2012 [2] Verdini & Grappin, ApJL, 808:L34, 2015 [3] Vech & Chen, ApJL, 832:L16, 2016 [4] Goldreich & Shridar, ApJ, 438:763, 1995 [5] Boldyrev, ApJL, 626:L37, 2005

  20. Orthodontic management of buccally erupted ectopic canine with two case reports

    Directory of Open Access Journals (Sweden)

    Avesh Sachan

    2012-01-01

    Full Text Available Ectopic canine teeth develop displaced from their normal position. Any permanent tooth can be ectopic, and the cause may be both genetic and environmental. Orthodontic treatment is justified because ectopic canine teeth can migrate in the jaw bone and may damage the adjacent teeth roots and bone. Orthodontic treatment is also justifiable for aesthetic reasons. Diagnosis and treatment of ectopically erupting permanent maxillary canines requires timely management by the orthodontist. Internal or external root resorption of teeth adjacent to the ectopic canine is the most common sequel. Malocclusion with severe crowding is difficult to treat without extraction. Non-extraction treatment of ectopic canines can compromise the patient′s profile. This article represents two cases of extraction treatment approach for buccally displaced or ectopic canine in a patient with severe crowding in the mandibular arch.

  1. Depression of Serotonin Synaptic Transmission by the Dopamine Precursor L-DOPA

    Directory of Open Access Journals (Sweden)

    Stephanie C. Gantz

    2015-08-01

    Full Text Available Imbalance between the dopamine and serotonin (5-HT neurotransmitter systems has been implicated in the comorbidity of Parkinson’s disease (PD and psychiatric disorders. L-DOPA, the leading treatment of PD, facilitates the production and release of dopamine. This study assessed the action of L-DOPA on monoamine synaptic transmission in mouse brain slices. Application of L-DOPA augmented the D2-receptor-mediated inhibitory postsynaptic current (IPSC in dopamine neurons of the substantia nigra. This augmentation was largely due to dopamine release from 5-HT terminals. Selective optogenetic stimulation of 5-HT terminals evoked dopamine release, producing D2-receptor-mediated IPSCs following treatment with L-DOPA. In the dorsal raphe, L-DOPA produced a long-lasting depression of the 5-HT1A-receptor-mediated IPSC in 5-HT neurons. When D2 receptors were expressed in the dorsal raphe, application of L-DOPA resulted in a D2-receptor-mediated IPSC. Thus, treatment with L-DOPA caused ectopic dopamine release from 5-HT terminals and a loss of 5-HT-mediated synaptic transmission.

  2. Diacylglycerol kinases in the coordination of synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Dongwon Lee

    2016-08-01

    Full Text Available Synaptic plasticity is activity-dependent modification of the efficacy of synaptic transmission. Although detailed mechanisms underlying synaptic plasticity are diverse and vary at different types of synapses, diacylglycerol (DAG-associated signaling has been considered as an important regulator of many forms of synaptic plasticity, including long-term potentiation (LTP and long-term depression (LTD. Recent evidence indicate that DAG kinases (DGKs, which phosphorylate DAG to phosphatidic acid to terminate DAG signaling, are important regulators of LTP and LTD, as supported by the results from mice lacking specific DGK isoforms. This review will summarize these studies and discuss how specific DGK isoforms distinctly regulate different forms of synaptic plasticity at pre- and postsynaptic sites. In addition, we propose a general role of DGKs as coordinators of synaptic plasticity that make local synaptic environments more permissive for synaptic plasticity by regulating DAG concentration and interacting with other synaptic proteins.

  3. Metabolic Turnover of Synaptic Proteins: Kinetics, Interdependencies and Implications for Synaptic Maintenance

    Science.gov (United States)

    Cohen, Laurie D.; Zuchman, Rina; Sorokina, Oksana; Müller, Anke; Dieterich, Daniela C.; Armstrong, J. Douglas; Ziv, Tamar; Ziv, Noam E.

    2013-01-01

    Chemical synapses contain multitudes of proteins, which in common with all proteins, have finite lifetimes and therefore need to be continuously replaced. Given the huge numbers of synaptic connections typical neurons form, the demand to maintain the protein contents of these connections might be expected to place considerable metabolic demands on each neuron. Moreover, synaptic proteostasis might differ according to distance from global protein synthesis sites, the availability of distributed protein synthesis facilities, trafficking rates and synaptic protein dynamics. To date, the turnover kinetics of synaptic proteins have not been studied or analyzed systematically, and thus metabolic demands or the aforementioned relationships remain largely unknown. In the current study we used dynamic Stable Isotope Labeling with Amino acids in Cell culture (SILAC), mass spectrometry (MS), Fluorescent Non–Canonical Amino acid Tagging (FUNCAT), quantitative immunohistochemistry and bioinformatics to systematically measure the metabolic half-lives of hundreds of synaptic proteins, examine how these depend on their pre/postsynaptic affiliation or their association with particular molecular complexes, and assess the metabolic load of synaptic proteostasis. We found that nearly all synaptic proteins identified here exhibited half-lifetimes in the range of 2–5 days. Unexpectedly, metabolic turnover rates were not significantly different for presynaptic and postsynaptic proteins, or for proteins for which mRNAs are consistently found in dendrites. Some functionally or structurally related proteins exhibited very similar turnover rates, indicating that their biogenesis and degradation might be coupled, a possibility further supported by bioinformatics-based analyses. The relatively low turnover rates measured here (∼0.7% of synaptic protein content per hour) are in good agreement with imaging-based studies of synaptic protein trafficking, yet indicate that the metabolic load

  4. Management of an Unusual Ectopic Eruption of Maxillary Canine.

    Science.gov (United States)

    Aileni, Kaladhar Reddy; Rachala, Madhukar Reddy; Prathima, Chintakunta Reddy; Naveen, Pitalla Kumar; Soujanya, Donthula

    2017-05-01

    Transposition of teeth is a rare condition, with a prevalence of 0.3-0.4% in general population. They are more commonly observed in females, and may occur unilaterally/bilaterally with greater frequency of left side occurrence in unilateral transposition cases. A 17-year-old female patient reported with the chief complaint of unaesthetic smile. On clinical examination the patient was diagnosed with Angle's class I malocclusion with an ectopically erupted maxillary left canine labial to the left central incisor with retained deciduous canine. The treatment plan decided was to extract the retained deciduous canine, level and align the ectopic canine using an R-loop. The treatment for the patient was finished in 14 months and was retained using a fixed lingual retainer in the upper and lower arches.

  5. Selective Uterine Artery Embolization for Management of Interstitial Ectopic Pregnancy

    International Nuclear Information System (INIS)

    Yang, Seung Boo; Lee, Sang Jin; Joe, Hwan Sung; Goo, Dong Erk; Chang, Yun Woo; Kim, Dong Hun

    2007-01-01

    Interstitial pregnancy is defined as any gestation that develops in the uterine portion of the fallopian tubes lateral to the round ligament. Interstitial pregnancies account for 2-4% of all ectopic pregnancies and have been reported to have an associated 2% to 2.5% maternal mortality rate. The traditional treatment for interstitial pregnancy using surgical cornual resection may cause infertility or uterine rupture in subsequent pregnancies. Recently, the early identification of intact interstitial pregnancy has been made possible in many cases with high resolution transvaginal ultrasound as well as more sensitive assays for betahuman chorionic gonadotropin (β-hCG). The treatment includes: hysteroscopic transcervical currettage, local and systemic methotrexate (MTX) therapy and prostaglandin or potassium chloride injection of the ectopic mass under sonographic guidance. We describe a case of successful treatment of interstitial pregnancy using uterine artery embolization, after failure of methotrexate treatment

  6. Ectopic lymphocytic thyroiditis: A case report and treatment options

    Directory of Open Access Journals (Sweden)

    Irami Araujo-Filho

    2017-12-01

    Full Text Available The presence of ectopic thyroid tissue is a rare entity. Non-gland migration occurs during the early stages of embryogenesis to the normal cervical location. Thus, ectopic tissue is lodged, in general, in the path of the thyroglossal duct in the middle line of the neck. The most common location is in the lingual zone, being the lingual thyroid. This, in most cases, will be asymptomatic. However, it is able to manifest itself with symptoms of dysphagia, dysphonia, obstruction of the upper airways or hemorrhage at any moment between childhood and adulthood. This article is a review of this disease, targeting mainly conduct, still very controversial in the literature. [Arch Clin Exp Surg 2017; 6(4.000: 221-227

  7. Selective Uterine Artery Embolization for Management of Interstitial Ectopic Pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung Boo; Lee, Sang Jin; Joe, Hwan Sung; Goo, Dong Erk; Chang, Yun Woo [Soonchunhyang University Gumi Hospital, Gumi (Korea, Republic of); Kim, Dong Hun [Chosun University Hospital, Gwangju (Korea, Republic of)

    2007-04-15

    Interstitial pregnancy is defined as any gestation that develops in the uterine portion of the fallopian tubes lateral to the round ligament. Interstitial pregnancies account for 2-4% of all ectopic pregnancies and have been reported to have an associated 2% to 2.5% maternal mortality rate. The traditional treatment for interstitial pregnancy using surgical cornual resection may cause infertility or uterine rupture in subsequent pregnancies. Recently, the early identification of intact interstitial pregnancy has been made possible in many cases with high resolution transvaginal ultrasound as well as more sensitive assays for betahuman chorionic gonadotropin ({beta}-hCG). The treatment includes: hysteroscopic transcervical currettage, local and systemic methotrexate (MTX) therapy and prostaglandin or potassium chloride injection of the ectopic mass under sonographic guidance. We describe a case of successful treatment of interstitial pregnancy using uterine artery embolization, after failure of methotrexate treatment.

  8. Three cases of ectopic sphenoid sinus pituitary adenoma.

    Science.gov (United States)

    Bobeff, Ernest Jan; Wiśniewski, Karol; Papierz, Wielisław; Stefańczyk, Ludomir; Jaskólski, Dariusz Jan

    2017-01-01

    Introduction: Ectopic sphenoid sinus pituitary adenoma is a rare tumour originating from embryologic remnants of Rathke's pouch. Although it is considered a clinically benign neoplasm, necrosis is encountered in 25% of cases and it can invade adjacent bone structures. Aims: To establish clinical, radiological and histopathological features of ectopic sphenoid sinus pituitary adenoma. Material and methods: Analysis of three cases: two females and one man, aged 61-70. Results: One patient presented with a unilateral hearing loss, the other two with headache and vertigo. They all suffered from type 2 diabetes mellitus. Neurological examination revealed no abnormality. Radiological imaging showed a sphenoid sinus space-occupying soft-tissue lesion with bone erosion in 2 cases and empty sella in 2 patients whereas one had a normal pituitary gland. All were operated on via the transnasal approach. Total resection was achieved in one patient and subtotal in two; in two cases we observed intact sellar dura and in one intact sellar floor. Histopathology showed immunoreactivity for synaptophysin in all cases and cytokeratin in two. The Ki-67 index was less than 2%. Immunohistochemical staining demonstrated growth hormone cells in all cases whereas prolactin and adrenocorticotropin in two. The patients were discharged home in good condition with no neurological deficits. Conclusions: Ectopic sphenoid sinus pituitary adenoma should always be considered in differential diagnosis of sphenoid sinus lesion in the elderly, especially in coexistence with empty sella or type 2 diabetes mellitus. Since ectopic sphenoid sinus pituitary adenoma is a benign lesion, surgical removal is an effective treatment. .

  9. Mediastinum Ectopic Parathyroid Adenoma Localized by Sestamibi-SPECT and

    International Nuclear Information System (INIS)

    Mazilu, C.; Mititelu, R.; Ghita, S.; Rimbu, A.; Marinescu, G.; Mazilu, A.; Codorean, I.

    2006-01-01

    Full text: Objective: Localizing of ectopic parathyroid adenomas, mainly of those located at large distal from cervical anterior region is very difficult by imaging methods, due to reduced number of specific imaging features. Material and Method: We present the case of a patient with hyper functional parathyroid tissue located in anterior mediastinum, detected by using nuclear medicine techniques (planar imaging and 99-m-Tc-Sestamibi) and CT with contrast agent. Results and discussions: Parathyroid scintigraphic imaging with metabolic radiotracer (99-m-Tc-Sestamibi) have shown normal uptake in thyroid area but shown a focal area with increased uptake in anterior mediastinum, on early and late planar images, transverse, sagittal and coronal SPECT images and on 3D reconstruction, suggesting the presence of ectopic parathyroid adenoma, which correlated with symptoms and laboratory analysis (high-modified values of PTH, Urinary Ca, Normal serum Ca). Thyroid ultrasonography normal aspect. CT native and with contrast agent showed remnant thymic tissue (?), pre-aortic anterior mediastinum nodule; normal thyroid aspect. Correlating this data was established the diagnosis of primary hyperparathyroidism due to mediastinum ectopic parathyroid adenoma. Surgical intervention showed intra thymic nodular process, well-defined, with 1 cm diameter in right thymic lobe. Thymectomy was realized. AP exam confirmed diagnosis of parathyroid adenoma. Post surgical determination of serum, urinary and PTH showed normalization of these values. Conclusions: In assessing parathyroid adenomas, mainly with ectopic location, combination of morphologic and functional techniques allows an accurate location of these processes, ensuring a correct diagnosis, adequate therapeutical management and optimal long-term prognosis for patient. (author)

  10. Three cases of ectopic sphenoid sinus pituitary adenoma

    Directory of Open Access Journals (Sweden)

    Ernest Jan Bobeff

    2017-03-01

    Full Text Available Introduction : Ectopic sphenoid sinus pituitary adenoma is a rare tumour originating from embryologic remnants of Rathke’s pouch. Although it is considered a clinically benign neoplasm, necrosis is encountered in 25% of cases and it can invade adjacent bone structures. Aims : To establish clinical, radiological and histopathological features of ectopic sphenoid sinus pituitary adenoma. Material and methods: Analysis of three cases: two females and one man, aged 61-70. Results : One patient presented with a unilateral hearing loss, the other two with headache and vertigo. They all suffered from type 2 diabetes mellitus. Neurological examination revealed no abnormality. Radiological imaging showed a sphenoid sinus space-occupying soft-tissue lesion with bone erosion in 2 cases and empty sella in 2 patients whereas one had a normal pituitary gland. All were operated on via the transnasal approach. Total resection was achieved in one patient and subtotal in two; in two cases we observed intact sellar dura and in one intact sellar floor. Histopathology showed immunoreactivity for synaptophysin in all cases and cytokeratin in two. The Ki-67 index was less than 2%. Immunohistochemical staining demonstrated growth hormone cells in all cases whereas prolactin and adrenocorticotropin in two. The patients were discharged home in good condition with no neurological deficits. Conclusions : Ectopic sphenoid sinus pituitary adenoma should always be considered in differential diagnosis of sphenoid sinus lesion in the elderly, especially in coexistence with empty sella or type 2 diabetes mellitus. Since ectopic sphenoid sinus pituitary adenoma is a benign lesion, surgical removal is an effective treatment.

  11. Ectopic pregnancy with tubal rupture: an analysis of 80 cases

    International Nuclear Information System (INIS)

    Ashfaq, S.; Aziz, S.; Hasan, M.; Sultan, S.; Irfan, S.M.

    2017-01-01

    Ectopic pregnancy (EP) is a major problem in obstetrics as there is evidence of increasing incidence throughout the world. It is an important cause of maternal morbidity and mortality. In Pakistan, the care seeking behaviour among female is limited that makes female vulnerable to die due to complication of ectopic pregnancy. The aim of this study is to determine the frequency of tubal rupture in ectopic pregnancy in Pakistani patients. Method: In this cross-sectional study data pertaining to age, gestational age, parity and duration of presenting symptoms were collected and analysed. Result: 80 patients were diagnosed to have ectopic pregnancy. The frequency of tubal rupture was 91.25%. It is encountered significantly more often in women with age of 26 years. More tubal rupture is found in patient with low parity, in which the frequency of tubal rupture is up to 100% and decrease up to 78.6% with increasing parity up to four. Furthermore, it is noted that increase in gestational age from 8 weeks to 10 weeks caused an increase in frequency of tubal rupture from 80 to 100% respectively. It is also noted that earlier the patient presents the lesser is the frequency of tubal rupture, as compared to late presentation beyond 3-4 days which make frequency up to 95%. Conclusion: Tubal rupture is still common cause of maternal morbidity and mortality, and is still a major challenge in gynaecological practice. Creating awareness amongst midwives and GPs regarding early diagnosis can contribute to decrease the mortality, morbidity and fertility loss related to EP. (author)

  12. Transcatheter Embolotherapy with N-Butyl Cyanoacrylate for Ectopic Varices

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Kim, Hyo-Cheol, E-mail: angiointervention@gmail.com; Jae, Hwan Jun, E-mail: jaemdphd@gmail.com; Jung, Hyun-Seok; Hur, Saebeom; Lee, Myungsu; Chung, Jin Wook [Seoul National University Hospital, Department of Radiology, Seoul National University College of Medicine (Korea, Republic of)

    2015-04-15

    PurposeTo address technical feasibility and clinical outcome of transcatheter embolotherapy with N-butyl cyanoacrylate (NBCA) for bleeding ectopic varices.MethodsThe institutional review board approved this retrospective study and waived informed consent. From January 2004 to June 2013, a total of 12 consecutive patients received transcatheter embolotherapy using NBCA for bleeding ectopic varices in our institute. Clinical and radiologic features of the endovascular procedures were comprehensively reviewed.ResultsPreprocedural computed tomography images revealed ectopic varices in the jejunum (n = 7), stoma (n = 2), rectum (n = 2), and duodenum (n = 1). The 12 procedures consisted of solitary embolotherapy (n = 8) and embolotherapy with portal decompression (main portal vein stenting in 3, transjugular intrahepatic portosystemic shunt in 1). With regard to vascular access, percutaneous transhepatic access (n = 7), transsplenic access (n = 4), and transjugular intrahepatic portosystemic shunt tract (n = 1) were used. There was no failure in either the embolotherapy or the vascular accesses (technical success rate, 100 %). Two patients died within 1 month from the procedure from preexisting fatal medical conditions. Only one patient, with a large varix that had been partially embolized by using coils and NBCA, underwent rebleeding 5.5 months after the procedure. The patient was retreated with NBCA and did not undergo any bleeding afterward for a follow-up period of 2.5 months. The remaining nine patients did not experience rebleeding during the follow-up periods (range 1.5–33.2 months).ConclusionTranscatheter embolotherapy using NBCA can be a useful option for bleeding ectopic varices.

  13. Fibroadenoma in axilla: another manifestation of ectopic breast.

    Science.gov (United States)

    Tiwary, Satyendra K; Kumar, Puneet; Khanna, Ajay Kumar

    2015-04-26

    Fibroadenoma of an accessory breast is a rare disease. The clinical significance lies in the fact that a number of cystic, inflammatory, neoplastic diseases similar to those of a normal breast have been reported in accessory breasts as well. Vigilant self-assessment and complete clinical examination are always encouraged to detect earliest malignancy in the axilla. We report two cases of ectopic breast fibroadenoma with the relevant literature. 2015 BMJ Publishing Group Ltd.

  14. Follicular adenoma in ectopic thyroid. A case-report.

    Science.gov (United States)

    Consalvo, Vincenzo; Barbieri, Gerarda; Rossetti, Amalia Rosaria Rita; Romano, Mafalda; Contieri, Rosaria; Tramontano, Salvatore; Rescigno, Carmela; Infranzi, Massimo; Lombardi, Domenico

    2017-01-01

    The term ectopic thyroid refers to the presence of thyroid tissue located far from its usual anatomic placement and with no vascular connection to the main gland. The presence of swelling in atypical locations is diagnostically differentiated from other pathologies like pleomorphic adenoma or carcinoma, inflammatory lesions like sialadenitis, neurogenic tumors, paraganglioma, fibrolipoma and lymphadenopaties of diverse etiologies. Here we present the case of a submandibular ectopic thyroid in a 67year old woman. She came to our attention for a left submandibular swelling. The anamnesis did not show related pathologies, as well as blood tests. Diagnostic image studies and a FNAC were performed. The mass was surgically removed and histopatology showed a follicular adenoma in the contest of the capsulated lesion. It is important to not underestimate these types of lesions and procede with hematochemical, instrumental tests and above all surgery that can eliminate any diagnostic uncertainty and on the whole be therapeutic. It should not be forgotten that ectopic thyroid tissue can be a site for adenoma or papillary carcinoma and thus any watch and wait strategy should be avoided. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  15. Multiple Ectopic Hepatocellular Carcinomas Arising in the Abdominal Cavity

    Directory of Open Access Journals (Sweden)

    Toru Miyake

    2012-09-01

    Full Text Available Ectopic hepatocellular carcinoma (HCC is a very rare clinical entity that is defined as HCC arising from extrahepatic liver tissue. This report presents a case of ectopic multiple HCC arising in the abdominal cavity. A 42-year-old otherwise healthy male presented with liver dysfunction at a general health checkup. Both HCV antibody and hepatitis B surface antigen were negative. Laboratory examination showed elevations in serum alpha-fetoprotein and PIVKA-II. Ultrasonography and computed tomography revealed multiple nodular lesions in the abdominal cavity with ascites without a possible primary tumor. Exploratory laparoscopy was performed, which revealed bloody ascites and multiple brown nodular tumors measuring approximately 10 mm in size that were disseminated on the perineum and mesentery. A postoperative PET-CT scan was performed but it did not reveal any evidence of a tumor in the liver. The tumors resected from the peritoneum were diagnosed as HCC. The present case of HCC was thought to have possibly developed from ectopic liver on the peritoneum or mesentery.

  16. A Challenging Case of an Ectopic Cushing Syndrome

    Directory of Open Access Journals (Sweden)

    Joana Menezes Nunes

    2014-01-01

    Full Text Available Bronchopulmonary carcinoids are rare pulmonary neoplasms although they account for most cases of ectopic ACTH syndromes. When feasible, the mainstay treatment is surgical resection of the tumor. We report the case of a 52-year-old woman with signs and symptoms suggestive of hypercortisolism for 12 months, admitted to our department because of community acquired pneumonia. Blood hormone analysis showed increased levels of ACTH and urinary free cortisol and nonsuppressibility to high- and low-dose dexamethasone tests. Pituitary MRI showed no lesion and no central-to-peripheral ACTH gradient was present in bilateral inferior petrosal sinus sampling. CRH stimulation test suggested an ectopic ACTH source. Thoracic CT scan revealed a nodular region measuring 12 mm located in the inferior lingular lobule of the left superior lung with negative uptake by 18-FDG-PET scan and negative SRS. The patient was successfully treated with an atypical lung resection and histology revealed an atypical bronchial carcinoid tumor with positive ACTH immunoreactivity. This was an interesting case because the patient was admitted due to pneumonia that may have been associated with her untreated and chronic hypercortisolism and a challenging case of ectopic ACTH syndrome due to conflicting results on the diagnostic exams.

  17. Acute Abdomen in Interstitial Ectopic Pregnancy, An Emergency Laparoscopic Treatment

    Directory of Open Access Journals (Sweden)

    E. Picardo

    2014-01-01

    Full Text Available The present case report demonstrates a laparoscopic approach to treat interstitial cornual pregnancy in emergency. Interstitial ectopic pregnancy develops in the uterine portion of the fallopian tube which accounts for 2–4% of all ectopic pregnancies and has the potential to cause life-threatening hemorrhage at rupture. The mortality rate for a woman diagnosed with such a pregnancy is 2–2.5%. Diagnosis of interstitial pregnancy is made by ultrasound. In this case a 32 year-old woman, Gravida 0 Parity 0 Living 0 Ectopic 1, presented to the emergency obstetrical room complaining acute abdominal pain. There was a history of 10 weeks of pregnancy but no pelvic ultrasound scan was performed before the access. A transvaginal ultrasound scan immediately performed demonstrated a gestational sac with viable fetus in the right interstitial region. Moreover there was an ultrasound evidence of hemoperitoneum. She was transferred to the operating room and an emergency laparoscopy surgery was performed. The postoperative course was uneventful and the patient was discharged two days after the surgery. Interstitial pregnancies present a difficult management problem with no absolute standard of care in literature. Laparoscopic technique is under study with favorable results. For our personal point of view a treatment via laparoscopy could be performed both in elective and in emergency cases.

  18. A rare malformation of urinary system: Right ectopic thoracic kidney

    Directory of Open Access Journals (Sweden)

    Musab Ilgi

    2017-01-01

    Full Text Available An ectopic kidney is a common developmental anomaly of the urinary system. However, the thoracic kidney (TK is the rarest state form of an aberrant kidney. The aim of this case report is defining the symptoms in TK diagnosis and constructing a treatment model will promote the best outcomes. These patients come to the physician with the various symptoms, and they could be diagnosed incidentally. In our case, we describe 40 years female patient with severe respiratory problems and upper back pain. In the pulmonary clinic, suspected mass was diagnosed with chest X-ray, and computerized tomography detected nontraumatic nonhernia associated, a truly ectopic TK. Moreover, the thoracic surgeon and urologist team decided to exploration and reconstructed the right ectopic kidney. The 1st month of the control of patient symptoms was disappeared. Overall, TK should be kept in mind in the differential diagnosis of thoracic tumors. Surgical exploration and reconstruction should be thought in patients who have severe respiratory symptoms.

  19. Management Strategies for Aggressive Cushing's Syndrome: From Macroadenomas to Ectopics

    Science.gov (United States)

    Pozza, Carlotta; Graziadio, Chiara; Giannetta, Elisa; Lenzi, Andrea; Isidori, Andrea M.

    2012-01-01

    Cushing's syndrome (CS) is a rare but severe clinical condition represented by an excessive endogenous cortisol secretion and hence excess circulating free cortisol, characterized by loss of the normal feedback regulation and circadian rhythm of the hypothalamic-pituitary axis due to inappropriate secretion of ACTH from a pituitary tumor (Cushing's disease, CD) or an ectopic source (ectopic ACTH secretion, EAS). The remaining causes (20%) are ACTH independent. As soon as the diagnosis is established, the therapeutic goal is the removal of the tumor. Whenever surgery is not curative, management of patients with CS requires a major effort to control hypercortisolemia and associated symptoms. A multidisciplinary approach that includes endocrinologists, neurosurgeons, oncologists, and radiotherapists should be adopted. This paper will focus on traditional and novel medical therapy for aggressive ACTH-dependent CS. Several drugs are able to reduce cortisol levels. Their mechanism of action involves blocking adrenal steroidogenesis (ketoconazole, metyrapone, aminoglutethimide, mitotane, etomidate) or inhibiting the peripheral action of cortisol through blocking its receptors (mifepristone “RU-486”). Other drugs include centrally acting agents (dopamine agonists, somatostatin receptor agonists, retinoic acid, peroxisome proliferator-activated receptor γ “PPAR-γ” ligands) and novel chemotherapeutic agents (temozolomide and tyrosine kinase inhibitors) which have a significant activity against aggressive pituitary or ectopic tumors. PMID:22934113

  20. Severe Cushing's syndrome and bilateral pulmonary nodules: beyond ectopic ACTH.

    Science.gov (United States)

    Tavares Bello, Carlos; van der Poest Clement, Emma; Feelders, Richard

    2017-01-01

    Cushing's syndrome is a rare disease that results from prolonged exposure to supraphysiological levels of glucocorticoids. Severe and rapidly progressive cases are often, but not exclusively, attributable to ectopic ACTH secretion. Extreme hypercortisolism usually has florid metabolic consequences and is associated with an increased infectious and thrombotic risk. The authors report on a case of a 51-year-old male that presented with severe Cushing's syndrome secondary to an ACTH-secreting pituitary macroadenoma, whose diagnostic workup was affected by concurrent subclinical multifocal pulmonary infectious nodules. The case is noteworthy for the atypically severe presentation of Cushing's disease, and it should remind the clinician of the possible infectious and thrombotic complications associated with Cushing's syndrome. Severe Cushing's syndrome is not always caused by ectopic ACTH secretion.Hypercortisolism is a state of immunosuppression, being associated with an increased risk for opportunistic infections.Infectious pulmonary infiltrates may lead to imaging diagnostic dilemmas when investigating a suspected ectopic ACTH secretion.Cushing's syndrome carries an increased thromboembolic risk that may even persist after successful surgical management.Antibiotic and venous thromboembolism prophylaxis should be considered in every patient with severe Cushing's syndrome.

  1. Management Strategies for Aggressive Cushing's Syndrome: From Macroadenomas to Ectopics

    Directory of Open Access Journals (Sweden)

    Carlotta Pozza

    2012-01-01

    Full Text Available Cushing’s syndrome (CS is a rare but severe clinical condition represented by an excessive endogenous cortisol secretion and hence excess circulating free cortisol, characterized by loss of the normal feedback regulation and circadian rhythm of the hypothalamic-pituitary axis due to inappropriate secretion of ACTH from a pituitary tumor (Cushing’s disease, CD or an ectopic source (ectopic ACTH secretion, EAS. The remaining causes (20% are ACTH independent. As soon as the diagnosis is established, the therapeutic goal is the removal of the tumor. Whenever surgery is not curative, management of patients with CS requires a major effort to control hypercortisolemia and associated symptoms. A multidisciplinary approach that includes endocrinologists, neurosurgeons, oncologists, and radiotherapists should be adopted. This paper will focus on traditional and novel medical therapy for aggressive ACTH-dependent CS. Several drugs are able to reduce cortisol levels. Their mechanism of action involves blocking adrenal steroidogenesis (ketoconazole, metyrapone, aminoglutethimide, mitotane, etomidate or inhibiting the peripheral action of cortisol through blocking its receptors (mifepristone “RU-486”. Other drugs include centrally acting agents (dopamine agonists, somatostatin receptor agonists, retinoic acid, peroxisome proliferator-activated receptor γ “PPAR-γ” ligands and novel chemotherapeutic agents (temozolomide and tyrosine kinase inhibitors which have a significant activity against aggressive pituitary or ectopic tumors.

  2. Bruchpilot in ribbon-like axonal agglomerates, behavioral defects, and early death in SRPK79D kinase mutants of Drosophila.

    Directory of Open Access Journals (Sweden)

    Vanessa Nieratschker

    2009-10-01

    Full Text Available Defining the molecular structure and function of synapses is a central theme in brain research. In Drosophila the Bruchpilot (BRP protein is associated with T-shaped ribbons ("T-bars" at presynaptic active zones (AZs. BRP is required for intact AZ structure and normal evoked neurotransmitter release. By screening for mutations that affect the tissue distribution of Bruchpilot, we have identified a P-transposon insertion in gene CG11489 (location 79D which shows high homology to mammalian genes for SR protein kinases (SRPKs. SRPKs phosphorylate serine-arginine rich splicing factors (SR proteins. Since proteins expressed from CG11489 cDNAs phosphorylate a peptide from a human SR protein in vitro, we name CG11489 the Drosophila Srpk79D gene. We have characterized Srpk79D transcripts and generated a null mutant. Mutation of the Srpk79D gene causes conspicuous accumulations of BRP in larval and adult nerves. At the ultrastructural level, these correspond to extensive axonal agglomerates of electron-dense ribbons surrounded by clear vesicles. Basic synaptic structure and function at larval neuromuscular junctions appears normal, whereas life expectancy and locomotor behavior of adult mutants are significantly impaired. All phenotypes of the mutant can be largely or completely rescued by panneural expression of SRPK79D isoforms. Isoform-specific antibodies recognize panneurally overexpressed GFP-tagged SRPK79D-PC isoform co-localized with BRP at presynaptic active zones while the tagged -PB isoform is found in spots within neuronal perikarya. SRPK79D concentrations in wild type apparently are too low to be revealed by these antisera. We propose that the Drosophila Srpk79D gene characterized here may be expressed at low levels throughout the nervous system to prevent the assembly of BRP containing agglomerates in axons and maintain intact brain function. The discovery of an SR protein kinase required for normal BRP distribution calls for the

  3. Synaptic Correlates of Working Memory Capacity.

    Science.gov (United States)

    Mi, Yuanyuan; Katkov, Mikhail; Tsodyks, Misha

    2017-01-18

    Psychological studies indicate that human ability to keep information in readily accessible working memory is limited to four items for most people. This extremely low capacity severely limits execution of many cognitive tasks, but its neuronal underpinnings remain unclear. Here we show that in the framework of synaptic theory of working memory, capacity can be analytically estimated to scale with characteristic time of short-term synaptic depression relative to synaptic current time constant. The number of items in working memory can be regulated by external excitation, enabling the system to be tuned to the desired load and to clear the working memory of currently held items to make room for new ones. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The Corticohippocampal Circuit, Synaptic Plasticity, and Memory

    Science.gov (United States)

    Basu, Jayeeta; Siegelbaum, Steven A.

    2015-01-01

    Synaptic plasticity serves as a cellular substrate for information storage in the central nervous system. The entorhinal cortex (EC) and hippocampus are interconnected brain areas supporting basic cognitive functions important for the formation and retrieval of declarative memories. Here, we discuss how information flow in the EC–hippocampal loop is organized through circuit design. We highlight recently identified corticohippocampal and intrahippocampal connections and how these long-range and local microcircuits contribute to learning. This review also describes various forms of activity-dependent mechanisms that change the strength of corticohippocampal synaptic transmission. A key point to emerge from these studies is that patterned activity and interaction of coincident inputs gives rise to associational plasticity and long-term regulation of information flow. Finally, we offer insights about how learning-related synaptic plasticity within the corticohippocampal circuit during sensory experiences may enable adaptive behaviors for encoding spatial, episodic, social, and contextual memories. PMID:26525152

  5. Electric Dipole Theory of Chemical Synaptic Transmission

    Science.gov (United States)

    Wei, Ling Y.

    1968-01-01

    In this paper we propose that chemicals such as acetylcholine are electric dipoles which when oriented and arranged in a large array could produce an electric field strong enough to drive positive ions over the junction barrier of the post-synaptic membrane and thus initiate excitation or produce depolarization. This theory is able to explain a great number of facts such as cleft size, synaptic delay, nonregeneration, subthreshold integration, facilitation with repetition, and the calcium and magnesium effects. It also shows why and how acetylcholine could act as excitatory or inhibitory transmitters under different circumstances. Our conclusion is that the nature of synaptic transmission is essentially electrical, be it mediated by electrical or chemical transmitters. PMID:4296121

  6. Astroglial Metabolic Networks Sustain Hippocampal Synaptic Transmission

    Science.gov (United States)

    Rouach, Nathalie; Koulakoff, Annette; Abudara, Veronica; Willecke, Klaus; Giaume, Christian

    2008-12-01

    Astrocytes provide metabolic substrates to neurons in an activity-dependent manner. However, the molecular mechanisms involved in this function, as well as its role in synaptic transmission, remain unclear. Here, we show that the gap-junction subunit proteins connexin 43 and 30 allow intercellular trafficking of glucose and its metabolites through astroglial networks. This trafficking is regulated by glutamatergic synaptic activity mediated by AMPA receptors. In the absence of extracellular glucose, the delivery of glucose or lactate to astrocytes sustains glutamatergic synaptic transmission and epileptiform activity only when they are connected by gap junctions. These results indicate that astroglial gap junctions provide an activity-dependent intercellular pathway for the delivery of energetic metabolites from blood vessels to distal neurons.

  7. Astroglial metabolic networks sustain hippocampal synaptic transmission.

    Science.gov (United States)

    Rouach, Nathalie; Koulakoff, Annette; Abudara, Veronica; Willecke, Klaus; Giaume, Christian

    2008-12-05

    Astrocytes provide metabolic substrates to neurons in an activity-dependent manner. However, the molecular mechanisms involved in this function, as well as its role in synaptic transmission, remain unclear. Here, we show that the gap-junction subunit proteins connexin 43 and 30 allow intercellular trafficking of glucose and its metabolites through astroglial networks. This trafficking is regulated by glutamatergic synaptic activity mediated by AMPA receptors. In the absence of extracellular glucose, the delivery of glucose or lactate to astrocytes sustains glutamatergic synaptic transmission and epileptiform activity only when they are connected by gap junctions. These results indicate that astroglial gap junctions provide an activity-dependent intercellular pathway for the delivery of energetic metabolites from blood vessels to distal neurons.

  8. Electronic, magnetic and transport properties of graphene ribbons terminated by nanotubes

    International Nuclear Information System (INIS)

    Akhukov, M A; Yuan Shengjun; Fasolino, A; Katsnelson, M I

    2012-01-01

    We study, by density functional and large-scale tight-binding transport calculations, the electronic structure, magnetism and transport properties of the recently proposed graphene ribbons with edges rolled to form nanotubes. Edges with armchair nanotubes present magnetic moments localized either in the tube or the ribbon and of metallic or half-metallic character, depending on the symmetry of the junction. These properties have potential for spin valve and spin filter devices with advantages over other proposed systems. Edges with zigzag nanotubes are either metallic or semiconducting without affecting the intrinsic mobility of the ribbon. Varying the type and size of the nanotubes and ribbons offers the possibility to tailor the magnetic and transport properties, making these systems very promising for applications. (paper)

  9. A micromagnetic study of the oscillations of pinned domain walls in magnetic ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Alejos, Oscar [Dpto. Electricidad y Electronica, Universidad de Valladolid, 47071 Valladolid (Spain)]. E-mail: oscaral@ee.uva.es; Torres, Carlos [Dpto. Electricidad y Electronica, Universidad de Valladolid, 47071 Valladolid (Spain); Hernandez-Gomez, Pablo [Dpto. Electricidad y Electronica, Universidad de Valladolid, 47071 Valladolid (Spain); Lopez-Diaz, Luis [Dpto. Fisica Aplicada, Universidad de Salamanca, 37071 Salamanca (Spain); Torres, Luis [Dpto. Fisica Aplicada, Universidad de Salamanca, 37071 Salamanca (Spain); Martinez, Eduardo [Dpto. Ingenieria Electromecanica, Universidad de Burgos, 09001 Burgos (Spain)

    2007-09-15

    The work studies the dynamics of domain walls in magnetic ribbons with thicknesses of the order of magnitude of the permalloy exchange length (5.7 nm) by means of micromagnetic simulations. Two small defects are symmetrically placed on both edges of the ribbon, one on each edge, occupying the whole ribbon thickness. One transverse domain wall is pinned by the defects, in a head-to-head configuration. A free wall oscillation is forced by applying a static external magnetic field in the direction of the large axis until the wall reaches a new equilibrium position (elongation), and then removed. Three dynamic regimes are observed depending on the size of the cross ribbon section.

  10. A micromagnetic study of the oscillations of pinned domain walls in magnetic ribbons

    International Nuclear Information System (INIS)

    Alejos, Oscar; Torres, Carlos; Hernandez-Gomez, Pablo; Lopez-Diaz, Luis; Torres, Luis; Martinez, Eduardo

    2007-01-01

    The work studies the dynamics of domain walls in magnetic ribbons with thicknesses of the order of magnitude of the permalloy exchange length (5.7 nm) by means of micromagnetic simulations. Two small defects are symmetrically placed on both edges of the ribbon, one on each edge, occupying the whole ribbon thickness. One transverse domain wall is pinned by the defects, in a head-to-head configuration. A free wall oscillation is forced by applying a static external magnetic field in the direction of the large axis until the wall reaches a new equilibrium position (elongation), and then removed. Three dynamic regimes are observed depending on the size of the cross ribbon section

  11. Manufacture of ribbon and solar cells of material of semiconductor grade

    International Nuclear Information System (INIS)

    1980-01-01

    A method is described of producing ribbon-like substantially monocrystalline bodies of silicon or other materials of semiconductor grade suitable for use in solar cells or other semiconductor devices. A tube of the material is made and a photovoltaic junction formed in it. The tube is then divided lengthwise into a number of ribbon-like bodies. The photovoltaic junction can be formed either by diffusion or by ion-implantation. (U.K.)

  12. Orthogonal ribbons for suspending test masses in interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Lee, B.H.; Ju, L.; Blair, D.G.

    2005-01-01

    We show that a simple modification of proposed ribbon suspensions for laser interferometric gravitational wave detectors can substantially reduce the amplitude of violin modes at the expense of a small deterioration of suspension thermal noise. Using low loss fused silica, large amplitude peaks which cause dynamic range problems can be reduced by 21 dB. The total number of horizontal longitudinal direction violin modes below 5 kHz is reduced to less than half that expected with conventional ribbon suspensions

  13. Orthogonal ribbons for suspending test masses in interferometric gravitational wave detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.H. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia)]. E-mail: bhl@physics.uwa.edu.au; Ju, L. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia); Blair, D.G. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia)

    2005-05-23

    We show that a simple modification of proposed ribbon suspensions for laser interferometric gravitational wave detectors can substantially reduce the amplitude of violin modes at the expense of a small deterioration of suspension thermal noise. Using low loss fused silica, large amplitude peaks which cause dynamic range problems can be reduced by 21 dB. The total number of horizontal longitudinal direction violin modes below 5 kHz is reduced to less than half that expected with conventional ribbon suspensions.

  14. Spaceflight-induced synaptic modifications within hair cells of the mammalian utricle.

    Science.gov (United States)

    Sultemeier, David R; Choy, Kristel R; Schweizer, Felix E; Hoffman, Larry F

    2017-06-01

    Exposure to the microgravity conditions of spaceflight alleviates the load normally imposed by the Earth's gravitational field on the inner ear utricular epithelia. Previous ultrastructural investigations have shown that spaceflight induces an increase in synapse density within hair cells of the rat utricle. However, the utricle exhibits broad physiological heterogeneity across different epithelial regions, and it is unknown whether capabilities for synaptic plasticity generalize to hair cells across its topography. To achieve systematic and broader sampling of the epithelium than was previously conducted, we used immunohistochemistry and volumetric image analyses to quantify synapse distributions across representative utricular regions in specimens from mice exposed to spaceflight (a 15-day mission of the space shuttle Discovery). These measures were compared with similarly sampled Earth-bound controls. Following paraformaldehyde fixation and microdissection, immunohistochemistry was performed on intact specimens to label presynaptic ribbons (anti-CtBP2) and postsynaptic receptor complexes (anti-Shank1A). Synapses were identified as closely apposed pre- and postsynaptic puncta. Epithelia from horizontal semicircular canal cristae served as "within-specimen" controls, whereas utricles and cristae from Earth-bound cohorts served as experimental controls. We found that synapse densities decreased in the medial extrastriolae of microgravity specimens compared with experimental controls, whereas they were unchanged in the striolae and horizontal cristae from the two conditions. These data demonstrate that structural plasticity was topographically localized to the utricular region that encodes very low frequency and static changes in linear acceleration, and illuminates the remarkable capabilities of utricular hair cells for synaptic plasticity in adapting to novel gravitational environments. NEW & NOTEWORTHY Spaceflight imposes a radically different sensory environment

  15. Effects of surface crystallization and oxidation in nanocrystalline FeNbCuSiB(P) ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Butvinová, B., E-mail: beata.butvinova@savba.sk [Institute of Physics SAS, Dúbravská cesta 9, 845 11 Bratislava (Slovakia); Butvin, P. [Institute of Physics SAS, Dúbravská cesta 9, 845 11 Bratislava (Slovakia); Brzózka, K. [Department of Physics, University of Technology and Humanities in Radom, Krasickiego 54, 26-600 Radom (Poland); Kuzminski, M. [Institute of Physics PAS, Al. Lotnikow 36/42, 02-668 Warsaw (Poland); Maťko, I.; Švec Sr, P. [Institute of Physics SAS, Dúbravská cesta 9, 845 11 Bratislava (Slovakia); Chromčíková, M. [Institute of Inorg. Chem. SAS, Centrum VILA, Študentská 2, 911 50 Trenčín (Slovakia)

    2017-02-15

    Si-poor Fe{sub 74}Nb{sub 3}Cu{sub 1}Si{sub 8}B{sub 14−x}P{sub x}, (x=0, 3) nanocrystalline ribbon-form alloys often form surfaces, which exert in-plane force on underlying ribbon interior when nanocrystallized in even modest presence of oxygen. Mostly unwanted hard-ribbon-axis magnetic anisotropy is standard result. Essential sources of the surface-caused stress have been sought and influence of P instead of B substitution on this effect was studied too. Preferred surface crystallization (PSC) was found to be the major reason. However P substitution suppresses PSC and promotes Fe-oxide formation, which eases the stress, softens the surfaces and provides different annealing evolution of surface properties. - Highlights: • Ar anneal of low-Si FeNbCuBSi ribbons produce surfaces that stress ribbon interior. • The stress comes mainly from preferred crystallization of surfaces. • Partial substitution of B by P changes annealing evolution of surface properties. • Without P, more crystalline surfaces significantly reduce ribbon's elasticity. • P suppresses surface crystallinity, promotes oxides and reduces mutual stress.

  16. Martensitic transformation behavior and shape memory properties of Ti-Ni-Pt melt-spun ribbons

    International Nuclear Information System (INIS)

    Inamura, Tomonari; Takahashi, Yohei; Hosoda, Hideki; Wakashima, Kenji; Nagase, Takeshi; Nakano, Takayoshi; Umakoshi, Yukichi; Miyazaki, Shuichi

    2006-01-01

    Martensitic transformation behavior and shape memory properties of a Ti 50 Ni 40 Pt 10 (TiNiPt) melt-spun ribbon fabricated by a single roll melt-spinning technique were characterized. The constituent phases of the as-spun ribbon were B2 (parent phase) and B19 (martensite phase) at room temperature. The B2-B19 martensitic transformation temperatures of the as-spun ribbon were 100K higher than those of the bulk-material with the same chemical composition. The martensitic transformation temperatures of the as-spun ribbon were decreased with increasing the temperature of the heat-treatment made after the melt-spinning. The as-spun ribbon and the heat-treated ribbons exhibited shape recovery by heating and/or pseudoelasticity. The martensitic transformation temperatures determined from the temperature dependence of the 0.2% flow stress of the pseudoelastic deformation were in good agreement with those of B2-B19 martensitic transformation determined by DSC. It was confirmed that the observed shape recovery and pseudoelasticity are shape memory effect and superelasticity due to the B2-B19 martensitic transformation. Shape memory effect and superelasticity of melt-spun TiNiPt alloy were found to appear at higher temperatures compared to those of Bulk-material with the same composition. (author)

  17. Evolutionary analysis of a novel zinc ribbon in the N-terminal region of threonine synthase.

    Science.gov (United States)

    Kaur, Gurmeet; Subramanian, Srikrishna

    2017-10-18

    Threonine synthase (TS) catalyzes the terminal reaction in the biosynthetic pathway of threonine and requires pyridoxal phosphate as a cofactor. TSs share a common catalytic domain with other fold type II PALP dependent enzymes. TSs are broadly grouped into two classes based on their sequence, quaternary structure, and enzyme regulation. We report the presence of a novel zinc ribbon domain in the N-terminal region preceding the catalytic core in TS. The zinc ribbon domain is present in TSs belonging to both classes. Our sequence analysis reveals that archaeal TSs possess all zinc chelating residues to bind a metal ion that are lacking in the structurally characterized homologs. Phylogenetic analysis suggests that TSs with an N-terminal zinc ribbon likely represents the ancestral state of the enzyme while TSs without a zinc ribbon must have diverged later in specific lineages. The zinc ribbon and its N- and C-terminal extensions are important for enzyme stability, activity and regulation. It is likely that the zinc ribbon domain is involved in higher order oligomerization or mediating interactions with other biomolecules leading to formation of larger metabolic complexes.

  18. Capillary origami: superhydrophobic ribbon surfaces and liquid marbles

    Directory of Open Access Journals (Sweden)

    Glen McHale

    2011-03-01

    Full Text Available In the wetting of a solid by a liquid it is often assumed that the substrate is rigid. However, for an elastic substrate the rigidity depends on the cube of its thickness and so reduces rapidly as the substrate becomes thinner as it approaches becoming a thin sheet. In such circumstances, it has been shown that the capillary forces caused by a contacting droplet of a liquid can shape the solid rather than the solid shaping the liquid. A substrate can be bent and folded as a (pinned droplet evaporates or even instantaneously and spontaneously wrapped on contact with a droplet. When this effect is used to create three dimensional shapes from initially flat sheets, the effect is called capillary origami or droplet wrapping.In this work, we consider how the conditions for the spontaneous, capillary induced, folding of a thin ribbon substrate might be altered by a rigid surface structure that, for a rigid substrate, would be expected to create Cassie–Baxter and Wenzel effects. For smooth thin substrates, droplet wrapping can occur for all liquids, including those for which the Young’s law contact angle (defined by the interfacial tensions is greater than 90° and which would therefore normally be considered relatively hydrophobic. However, consideration of the balance between bending and interfacial energies suggests that the tendency for droplet wrapping can be suppressed for some liquids by providing the flexible solid surface with a rigid topographic structure. In general, it is known that when a liquid interacts with such a structure it can either fully penetrate the structure (the Wenzel case or it can bridge between the asperities of the structure (the Cassie–Baxter case.In this report, we show theoretically that droplet wrapping should occur with both types of solid–liquid contact. We also derive a condition for the transition between the Cassie–Baxter and Wenzel type droplet wrapping and relate it to the same transition condition

  19. Flexible Proton-Gated Oxide Synaptic Transistors on Si Membrane.

    Science.gov (United States)

    Zhu, Li Qiang; Wan, Chang Jin; Gao, Ping Qi; Liu, Yang Hui; Xiao, Hui; Ye, Ji Chun; Wan, Qing

    2016-08-24

    Ion-conducting materials have received considerable attention for their applications in fuel cells, electrochemical devices, and sensors. Here, flexible indium zinc oxide (InZnO) synaptic transistors with multiple presynaptic inputs gated by proton-conducting phosphorosilicate glass-based electrolyte films are fabricated on ultrathin Si membranes. Transient characteristics of the proton gated InZnO synaptic transistors are investigated, indicating stable proton-gating behaviors. Short-term synaptic plasticities are mimicked on the proposed proton-gated synaptic transistors. Furthermore, synaptic integration regulations are mimicked on the proposed synaptic transistor networks. Spiking logic modulations are realized based on the transition between superlinear and sublinear synaptic integration. The multigates coupled flexible proton-gated oxide synaptic transistors may be interesting for neuroinspired platforms with sophisticated spatiotemporal information processing.

  20. Position of the IBEX ribbon as a key to understand its origin

    Science.gov (United States)

    Swaczyna, Pawel; Bzowski, Maciej; Sokół, Justyna M.; Christian, Eric R.; Funsten, Herbert O.; McComas, David J.; Schwadron, Nathan A.

    2017-04-01

    Observations of the energetic neutral atom (ENA) emission by the Interstellar Boundary Explorer (IBEX) allow for remote sensing of the plasma properties in heliosheath. The first IBEX results revealed an unexpected arc-like enhancement of the ENA flux in the sky, dubbed the IBEX ribbon. This discovery led to formulation of more than a dozen hypotheses on its origin. The emission source region proposed in these hypotheses span the heliospheric termination shock up to a hypothetical nearby interface between the Local Interstellar Cloud and a local bay in the Local Bubble. Among these hypotheses is the concept that the ribbon is produced by the secondary ENA mechanism, operating in the outer heliosheath. The observational strategy of IBEX allows observation of the same part of the sky from the opposite sides of the Sun every six months and thus provides parallax viewing with a baseline of 2 AU. After correcting the observations for the Compton-Getting effect and for gravitational deflection and radiation pressure, we use this parallax viewing to precisely determine the apparent position of the maximum flux associated with the ribbon. We find that the ribbon peak position differs semi-annually by an angle of 0.41±0.15 deg, which we interpret as the parallax effect. This angle corresponds to a distance of 140-38+84 AU, and thus suggests that most likely the ribbon's source is located just beyond the heliopause. Comparison of the IBEX ribbon position in five energy steps of IBEX-Hi shows a systematic shift, which changes the position of the ribbon center by ˜10 deg. We find that it can be explained using an analytic model of the secondary ENA mechanism with the neutralized supersonic solar wind as the source of the primary ENAs, which are ionized in the outer heliosheath, picked up by the ambient magnetic field, and eventually re-neutralized (as originally conceived, McComas et al. 2009). We use a realistic model of the solar wind evolution dependent on heliographic

  1. MAPK3 at the Autism-Linked Human 16p11.2 Locus Influences Precise Synaptic Target Selection at Drosophila Larval Neuromuscular Junctions.

    Science.gov (United States)

    Park, Sang Mee; Park, Hae Ryoun; Lee, Ji Hye

    2017-02-01

    Proper synaptic function in neural circuits requires precise pairings between correct pre- and post-synaptic partners. Errors in this process may underlie development of neuropsychiatric disorders, such as autism spectrum disorder (ASD). Development of ASD can be influenced by genetic factors, including copy number variations (CNVs). In this study, we focused on a CNV occurring at the 16p11.2 locus in the human genome and investigated potential defects in synaptic connectivity caused by reduced activities of genes located in this region at Drosophila larval neuromuscular junctions, a well-established model synapse with stereotypic synaptic structures. A mutation of rolled , a Drosophila homolog of human mitogen-activated protein kinase 3 ( MAPK3 ) at the 16p11.2 locus, caused ectopic innervation of axonal branches and their abnormal defasciculation. The specificity of these phenotypes was confirmed by expression of wild-type rolled in the mutant background. Albeit to a lesser extent, we also observed ectopic innervation patterns in mutants defective in Cdk2, Gα q , and Gp93, all of which were expected to interact with Rolled MAPK3. A further genetic analysis in double heterozygous combinations revealed a synergistic interaction between rolled and Gp93 . In addition, results from RT-qPCR analyses indicated consistently reduced rolled mRNA levels in Cdk2 , Gα q , and Gp93 mutants. Taken together, these data suggest a central role of MAPK3 in regulating the precise targeting of presynaptic axons to proper postsynaptic targets, a critical step that may be altered significantly in ASD.

  2. P2X Receptors and Synaptic Plasticity

    Czech Academy of Sciences Publication Activity Database

    Pankratov, Y.; Lalo, U.; Krishtal, A.; Verkhratsky, Alexei

    2009-01-01

    Roč. 158, č. 1 (2009), s. 137-148 ISSN 0306-4522 Institutional research plan: CEZ:AV0Z50390512 Keywords : ATP * P2X receptors * synaptic plasticity Subject RIV: FH - Neurology Impact factor: 3.292, year: 2009

  3. Synaptic plasticity and the warburg effect

    KAUST Repository

    Magistretti, Pierre J.

    2014-01-01

    Functional brain imaging studies show that in certain brain regions glucose utilization exceeds oxygen consumption, indicating the predominance of aerobic glycolysis. In this issue, Goyal et al. (2014) report that this metabolic profile is associated with an enrichment in the expression of genes involved in synaptic plasticity and remodeling processes. © 2014 Elsevier Inc.

  4. Neuronal cytoskeleton in synaptic plasticity and regeneration.

    Science.gov (United States)

    Gordon-Weeks, Phillip R; Fournier, Alyson E

    2014-04-01

    During development, dynamic changes in the axonal growth cone and dendrite are necessary for exploratory movements underlying initial axo-dendritic contact and ultimately the formation of a functional synapse. In the adult central nervous system, an impressive degree of plasticity is retained through morphological and molecular rearrangements in the pre- and post-synaptic compartments that underlie the strengthening or weakening of synaptic pathways. Plasticity is regulated by the interplay of permissive and inhibitory extracellular cues, which signal through receptors at the synapse to regulate the closure of critical periods of developmental plasticity as well as by acute changes in plasticity in response to experience and activity in the adult. The molecular underpinnings of synaptic plasticity are actively studied and it is clear that the cytoskeleton is a key substrate for many cues that affect plasticity. Many of the cues that restrict synaptic plasticity exhibit residual activity in the injured adult CNS and restrict regenerative growth by targeting the cytoskeleton. Here, we review some of the latest insights into how cytoskeletal remodeling affects neuronal plasticity and discuss how the cytoskeleton is being targeted in an effort to promote plasticity and repair following traumatic injury in the central nervous system. © 2013 International Society for Neurochemistry.

  5. Synaptic remodeling, synaptic growth and the storage of long-term memory in Aplysia.

    Science.gov (United States)

    Bailey, Craig H; Kandel, Eric R

    2008-01-01

    Synaptic remodeling and synaptic growth accompany various forms of long-term memory. Storage of the long-term memory for sensitization of the gill-withdrawal reflex in Aplysia has been extensively studied in this respect and is associated with the growth of new synapses by the sensory neurons onto their postsynaptic target neurons. Recent time-lapse imaging studies of living sensory-to-motor neuron synapses in culture have monitored both functional and structural changes simultaneously so as to follow remodeling and growth at the same specific synaptic connections continuously over time and to examine the functional contribution of these learning-related structural changes to the different time-dependent phases of memory storage. Insights provided by these studies suggest the synaptic differentiation and growth induced by learning in the mature nervous system are highly dynamic and often rapid processes that can recruit both molecules and mechanisms used for de novo synapse formation during development.

  6. Ectopic olfactory neuroblastoma: report of four cases and a review of the literature.

    LENUS (Irish Health Repository)

    Wormald, R

    2011-04-01

    Our objective is to present a short series of four rare cases of ectopic olfactory neuroblastoma. Our methods present four case reports of ectopic olfactory neuroblastoma and a review of the literature for management and treatment of this disease. The results indicate short case series reports of ectopic olfactory neuroblastoma arising from the anterior ethmoidal sinuses, the nasopharynx, the lateral nasal wall and the floor of the nose. The discussion focuses on likely origins of ectopic olfactory neuroblastoma, its clinical features and management. We conclude that ectopic olfactory neuroblastoma is a rare disease. Treatment principles are the same for non-ectopic disease and guided by extension into adjacent structures such as the orbit or anterior cranial fossa and usually involves surgery with or without adjuvant radiotherapy.

  7. Synaptic Plasticity, Dementia and Alzheimer Disease.

    Science.gov (United States)

    Skaper, Stephen D; Facci, Laura; Zusso, Morena; Giusti, Pietro

    2017-01-01

    Neuroplasticity is not only shaped by learning and memory but is also a mediator of responses to neuron attrition and injury (compensatory plasticity). As an ongoing process it reacts to neuronal cell activity and injury, death, and genesis, which encompasses the modulation of structural and functional processes of axons, dendrites, and synapses. The range of structural elements that comprise plasticity includes long-term potentiation (a cellular correlate of learning and memory), synaptic efficacy and remodelling, synaptogenesis, axonal sprouting and dendritic remodelling, and neurogenesis and recruitment. Degenerative diseases of the human brain continue to pose one of biomedicine's most intractable problems. Research on human neurodegeneration is now moving from descriptive to mechanistic analyses. At the same time, it is increasing apparently that morphological lesions traditionally used by neuropathologists to confirm post-mortem clinical diagnosis might furnish us with an experimentally tractable handle to understand causative pathways. Consider the aging-dependent neurodegenerative disorder Alzheimer's disease (AD) which is characterised at the neuropathological level by deposits of insoluble amyloid β-peptide (Aβ) in extracellular plaques and aggregated tau protein, which is found largely in the intracellular neurofibrillary tangles. We now appreciate that mild cognitive impairment in early AD may be due to synaptic dysfunction caused by accumulation of non-fibrillar, oligomeric Aβ, occurring well in advance of evident widespread synaptic loss and neurodegeneration. Soluble Aβ oligomers can adversely affect synaptic structure and plasticity at extremely low concentrations, although the molecular substrates by which synaptic memory mechanisms are disrupted remain to be fully elucidated. The dendritic spine constitutes a primary locus of excitatory synaptic transmission in the mammalian central nervous system. These structures protruding from dendritic

  8. THE NATURE OF FLARE RIBBONS IN CORONAL NULL-POINT TOPOLOGY

    International Nuclear Information System (INIS)

    Masson, S.; Aulanier, G.; Pariat, E.; Schrijver, C. J.

    2009-01-01

    Flare ribbons are commonly attributed to the low-altitude impact, along the footprints of separatrices or quasi-separatrix layers (QSLs), of particle beams accelerated through magnetic reconnection. If reconnection occurs at a three-dimensional coronal magnetic null point, the footprint of the dome-shaped fan surface would map a closed circular ribbon. This paper addresses the following issues: does the entire circular ribbon brighten simultaneously, as expected because all fan field lines pass through the null point? And since the spine separatrices are singular field lines, do spine-related ribbons look like compact kernels? What can we learn from these observations about current sheet formation and magnetic reconnection in a null-point topology? The present study addresses these questions by analyzing Transition Region and Coronal Explorer and Solar and Heliospheric Observatory/Michelson Doppler Imager observations of a confined flare presenting a circular ribbon. Using a potential field extrapolation, we linked the circular shape of the ribbon with the photospheric mapping of the fan field lines originating from a coronal null point. Observations show that the flare ribbon outlining the fan lines brightens sequentially along the counterclockwise direction and that the spine-related ribbons are elongated. Using the potential field extrapolation as initial condition, we conduct a low-β resistive magnetohydrodynamics simulation of this observed event. We drive the coronal evolution by line-tied diverging boundary motions, so as to emulate the observed photospheric flow pattern associated with some magnetic flux emergence. The numerical analysis allows us to explain several observed features of the confined flare. The vorticity induced in the fan by the prescribed motions causes the spines to tear apart along the fan. This leads to formation of a thin current sheet and induces null-point reconnection. We also find that the null point and its associated topological

  9. Supramolecular ribbons from amphiphilic trisamides self-assembly.

    Science.gov (United States)

    García, Fátima; Buendía, Julia; Sánchez, Luis

    2011-08-05

    Two amphiphilic C(3)-symmetric OPE-based trisamides have been synthesized and their self-assembling features investigated in solution and on surface. Variable-temperature UV-vis experiments demonstrate the cooperative supramolecular polymerization of these trisamides that self-assemble by the operation of triple C═O···H-N H-bonding arrays between the amide functional groups and π-π stacking between the aromatic units. The helical organization of the aggregates has been demonstrated by circular dichroism at a concentration as low as 1 × 10(-4) M in acetonitrile. In the reported trisamides, the large hydrophobic aromatic core acts as a solvophobic module impeding the interaction between the polar TEG chains and the amide H-bonds. This strategy makes unnecessary the separation of the amide functional groups to the polar tri(ethylene glycol) chains by paraffinic fragments. Achiral trisamide 1 self-assembles into flat ribbon-like structures that experience an amplification of chirality by the addition of a small amount of chiral 2 that generates twisted stripes.

  10. MR imaging in children with ectopic pituitary gland and anterior hypopituitarism.

    Directory of Open Access Journals (Sweden)

    Patkar D

    1999-07-01

    Full Text Available Posterior pituitary ectopia refers to an absent normal posterior pituitary bright spot within the sella with ectopic bright signal at another site (such as the median eminence on a weighted magnetic resonance. We describe two children with idiopathic anterior hypopituitarism who showed an ectopic posterior pituitary and absent pituitary stalk on imaging. We emphasize the association of the absent pituitary stalk in ectopic pituitary gland and low growth hormone levels.

  11. MR imaging in children with ectopic pituitary gland and anterior hypopituitarism.

    OpenAIRE

    Patkar D; Patankar T; Krishnan A; Prasad S; Shah J; Limdi J

    1999-01-01

    Posterior pituitary ectopia refers to an absent normal posterior pituitary bright spot within the sella with ectopic bright signal at another site (such as the median eminence) on a weighted magnetic resonance. We describe two children with idiopathic anterior hypopituitarism who showed an ectopic posterior pituitary and absent pituitary stalk on imaging. We emphasize the association of the absent pituitary stalk in ectopic pituitary gland and low growth hormone levels.

  12. Ectopic decidua of the greater omentum: a case report

    Directory of Open Access Journals (Sweden)

    Biserka Pigac

    2016-04-01

    Full Text Available Ectopic decidua is defined as extrauterine deposits of decidual stromal cells. It occurs in 85-100% of pregnancies. Focal sites can be present in various locations, yet a peritoneal location is rare. A 24- year- old woman underwent a cesarean section in 39th week of her first pregnancy, during which adhesions of the omentum to the fundus, entire left side of the uterus, and a part of the right front abdominal wall were found. An operative specimen was taken for a pathohistological analysis under the assumption of being fibrous adhesive tissue. The analysis revealed ectopic decidual tissue composed of large, polygonal cells with eosinophilic cytoplasm, and large nuclei with conspicuous nucleoli infiltrated with mature fatty cells and lymphocytes. Strong staining for vimentin was observed in the decidual cell cytoplasm and for a progesterone- receptor in the cell nuclei, medium staining was detected for S-100, and negative staining for CK 5/ 6, HMB-45, desmin, smooth muscle actin, estrogen and androgen- receptors. We present this case in order to educate clinicians and pathologists about the phenomenon of ectopic deciduosis. Although it can exist as asymptomatic condition, we point out the importance of considering this condition since it can result in serious pathology, like intraperitoneal hemorrhage and labour obstruction, if remains unrecognized. Another pitfall is possible confusion of this entity with other conditions. A resemblance to adhesions of the omentum and malignant neoplastic lesions, like squamous cell and metastatic carcinoma, metastatic melanoma, malignant decidual mesothelioma, metastatic mucin -producing adenocarcinoma, can be deceiving. These obstacles may present a pitfall to clinicians and pathologists, with a negative impact on patient treatment and outcome.

  13. Embryonic miRNA profiles of normal and ectopic pregnancies.

    Directory of Open Access Journals (Sweden)

    Francisco Dominguez

    Full Text Available Our objective was to investigate the miRNA profile of embryonic tissues in ectopic pregnancies (EPs and controlled abortions (voluntary termination of pregnancy; VTOP. Twenty-three patients suffering from tubal EP and twenty-nine patients with a normal ongoing pregnancy scheduled for a VTOP were recruited. Embryonic tissue samples were analyzed by miRNA microarray and further validated by real time PCR. Microarray studies showed that four miRNAs were differentially downregulated (hsa-mir-196b, hsa-mir-30a, hsa-mir-873, and hsa-mir-337-3p and three upregulated (hsa-mir-1288, hsa-mir-451, and hsa-mir-223 in EP compared to control tissue samples. Hsa-miR-196, hsa-miR-223, and hsa-miR-451 were further validated by real time PCR in a wider population of EP and control samples. We also performed a computational analysis to identify the gene targets and pathways which might be modulated by these three differentially expressed miRNAs. The most significant pathways found were the mucin type O-glycan biosynthesis and the ECM-receptor-interaction pathways. We also checked that the dysregulation of these three miRNAs was able to alter the expression of the gene targets in the embryonic tissues included in these pathways such as GALNT13 and ITGA2 genes. In conclusion, analysis of miRNAs in ectopic and eutopic embryonic tissues shows different expression patterns that could modify pathways which are critical for correct implantation, providing new insights into the understanding of ectopic implantation in humans.

  14. Ectopic Fat and Insulin Resistance: Pathophysiology and Effect of Diet and Lifestyle Interventions

    Directory of Open Access Journals (Sweden)

    M. Snel

    2012-01-01

    Full Text Available The storage of triglyceride (TG droplets in nonadipose tissues is called ectopic fat storage. Ectopic fat is associated with insulin resistance and type 2 diabetes mellitus (T2DM. Not the triglycerides per se but the accumulation of intermediates of lipid metabolism in organs, such as the liver, skeletal muscle, and heart seem to disrupt metabolic processes and impair organ function. We describe the mechanisms of ectopic fat depositions in the liver, skeletal muscle, and in and around the heart and the consequences for each organs function. In addition, we systematically reviewed the literature for the effects of diet-induced weight loss and exercise on ectopic fat depositions.

  15. Fibrocystic disease of vulvar ectopic breast tissue. Case report and review of the literature.

    Science.gov (United States)

    Baykal, C; Tulunay, G; Usubutun, A; Küçükali, T; Ozer, S; Demir, O F

    2004-01-01

    Mammary glands located in the vulvar region have been named as ectopic breast tissue or anogenital mammary glands by different authors. Literature on pathologies of ectopic breast tissue located in the vulvar region is rare. Most of the reports are about the malignancies arising from this ectopic tissue. We report a case of fibrocystic disease of the mammary glands in the vulva in a 25-year-old pregnant woman. Her disease was exaggerated during pregnancy. Ectopic breast tissue in the vulva is a rare entity and fibrocystic disease of this tissue has rarely been reported in the English literature. Copyright (c) 2004 S. Karger AG, Basel.

  16. Ectopic eruption of maxillary central incisor through abnormally thickened labial frenum: An unusual presentation

    Directory of Open Access Journals (Sweden)

    Neeraj Gugnani

    2017-01-01

    Full Text Available Ectopic eruption is a deviation from the normal eruption pattern, making the tooth erupt out of its normal position, and possibly causing resorption of adjacent primary teeth. A wide range of etiological factors may be responsible for ectopic eruption of the teeth, so their management depends on the correction of the established etiological factor. The present case report describes an unusual case of ectopically erupted central incisor encased within an abnormally thickened labial frenum, which was treated by orthodontic repositioning of the ectopically erupting tooth after frenectomy.

  17. Ectopic prostatic tissue in the rectum: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Myung Jin; Noh, Kyung Hee; Jeon, Doo Sung; Lee, Kwang Min [Presbyterian Medical Center, Jeonju (Korea, Republic of)

    2017-02-15

    Ectopic prostatic tissue (EPT) outside the male genitourinary tract is an unusual finding, and it is very rarely found in the rectum or around the peri-rectal region. In addition, the radiologic features of EPT are seldom reported. Also, it is difficult to differentiate EPT found in the rectal subepithelium from the other types of subepithelial tumors. We present here a unique case of EPT found in the retrorectal region, along with the radiologic findings of transrectal ultrasonography, computed tomography, and magnetic resonance imaging with their pathologic correlations.

  18. An Ectopic Case of Tunga spp. Infection in Peru

    Science.gov (United States)

    Maco, Vicente; Maco, Vicente P.; Gotuzzo, Eduardo

    2010-01-01

    Tungiasis is a neglected ectoparasitism of impoverished areas in South America and sub-Saharan Africa. The sand flea Tunga spp. preferably infests the soles and the periungueal and interdigital regions of the feet. Ectopic tungiasis is rare, even in highly endemic areas. We describe a case of an indigenous patient in Peru who presented with a nodular lesion in the extensor aspect of the knee and whose biopsy was compatible with Tunga spp. This is the first documented case of knee tungiasis in an endemic country. The historical, clinical, histological, and current epidemiological aspects of tungiasis in Peru are discussed here. PMID:20519602

  19. Cystic adventitial degeneration: ectopic ganglia from adjacent joint capsules.

    Science.gov (United States)

    Ortmann, J; Widmer, M K; Gretener, S; Do, D D; Willenberg, T; Daliri, A; Baumgartner, I

    2009-11-01

    Cystic adventitial degeneration is a rare non-atherosclerotic cause of peripheral arterial occlusive disease, mainly seen in young men without other evidence of vascular disease. Diagnosis will be established by clinical findings and by ultrasound or angiography and can be treated by excision or enucleation of the affected arterial segment or by percutaneous ultrasound-guided aspiration. However, the etiology of adventitial cysts remains unknown. We report a case of cystic adventitial degeneration showing a connection between the joint capsule and the adventitial cyst, supporting the theory that cystic adventitial degeneration may represent ectopic ganglia from adjacent joint capsules.

  20. Congenital bilateral perisylvian syndrome with pituitary hypoplasia and ectopic neurohypophysis

    Energy Technology Data Exchange (ETDEWEB)

    Yekeler, Ensar; Genchellac, Hakan; Dursun, Memduh; Acunas, Gulden [Istanbul Faculty of Medicine, Department of Radiology, Istanbul (Turkey); Ozmen, Meral [Istanbul Faculty of Medicine, Department of Paediatric Neurology, Istanbul (Turkey)

    2004-11-01

    Congenital bilateral perisylvian syndrome (CBPS) is a congenital neurological syndrome characterized by pseudobulbar palsy, cognitive deficits and bilateral perisylvian abnormalities observed on imaging. The described abnormality in CBPS is polymicrogyria located in the frontal, parietal, and/or occipital lobes. A few syndromes or abnormalities associated with this syndrome have been documented. Pituitary abnormalities are rare disorders. Association of CBPS with pituitary abnormalities has not been reported previously. In this case, a combination of bilateral perisylvian polymicrogyria with pituitary hypoplasia and ectopic neurohypophysis, caused by a possible single common insult, is presented. (orig.)

  1. Congenital bilateral perisylvian syndrome with pituitary hypoplasia and ectopic neurohypophysis

    International Nuclear Information System (INIS)

    Yekeler, Ensar; Genchellac, Hakan; Dursun, Memduh; Acunas, Gulden; Ozmen, Meral

    2004-01-01

    Congenital bilateral perisylvian syndrome (CBPS) is a congenital neurological syndrome characterized by pseudobulbar palsy, cognitive deficits and bilateral perisylvian abnormalities observed on imaging. The described abnormality in CBPS is polymicrogyria located in the frontal, parietal, and/or occipital lobes. A few syndromes or abnormalities associated with this syndrome have been documented. Pituitary abnormalities are rare disorders. Association of CBPS with pituitary abnormalities has not been reported previously. In this case, a combination of bilateral perisylvian polymicrogyria with pituitary hypoplasia and ectopic neurohypophysis, caused by a possible single common insult, is presented. (orig.)

  2. Interventional ovarian tube catheterization in treating tubal ectopic pregnancy

    International Nuclear Information System (INIS)

    Hu Yi; Xiong Linhui; Du Pianqin; Chen Jiabin

    2004-01-01

    Objective: To explore the feasibility and curative effect of treating tubal pregnancy through the fallopian tube with interventional catheterization decrease the difficulty of the procedure and shorten the consuming time. Methods: Applying the method of interventional catheterization of fallopian tube and injecting 0.5 mg atropine at the cervix beforehand, then 70 mg MTX was administered into the fallopian tube. Results: 113 patients were successfully recovered with health except one without any adversary complication. Conclusions: The interventional fallopian tube catheterization for treating ectopic pregnancy is a simple, safe, minitraumatic, quick and effective method. (authors)

  3. Development of variable width ribbon heating elements for liquid metal and gas-cooled fast breeder reactor fuel rod simulators

    International Nuclear Information System (INIS)

    McCulloch, R.W.; Lovell, R.T.; Post, D.W.; Snyder, S.D.

    1980-01-01

    Variable width ribbon heating elements have been fabricated which provide a chopped cosine, variable heat flux profile for fuel rod simulators used in test loops by the Breeder Reactor Program Thermal Hydraulic Out-of-Reactor Safety test facility and the Gas-Cooled Fast Breeder Reactor Core Flow Test Loop. Thermal, mechanical, and electrical design considerations result in the derivation of an analytical expression for the ribbon contours. From this, the ribbons are machined and wound on numerically controlled equipment. Postprocessing and inspection results in a wound, variable width ribbon with the precise dimensional, electrical, and mechanical properties needed for use in fuel pin simulators

  4. Silicon ribbon growth by a capillary action shaping technique. Annual report (Quarterly technical progress report No. 9)

    Energy Technology Data Exchange (ETDEWEB)

    Schwuttke, G.H.; Ciszek, T.F.; Kran, A.

    1977-10-01

    Progress on the technological and economical assessment of ribbon growth of silicon by a capillary action shaping technique is reported. Progress in scale-up of the process from 50 mm to 100 mm ribbon widths is presented, the use of vitreous carbon as a crucible material is analyzed, and preliminary tests of CVD Si/sub 3/N/sub 4/ as a potential die material are reported. Diffusion length measurements by SEM, equipment and procedure for defect display under MOS structure in silicon ribbon for lifetime interpretation, and an assessment of ribbon technology are discussed. (WHK)

  5. Influence of Synaptic Depression on Memory Storage Capacity

    Science.gov (United States)

    Otsubo, Yosuke; Nagata, Kenji; Oizumi, Masafumi; Okada, Masato

    2011-08-01

    Synaptic efficacy between neurons is known to change within a short time scale dynamically. Neurophysiological experiments show that high-frequency presynaptic inputs decrease synaptic efficacy between neurons. This phenomenon is called synaptic depression, a short term synaptic plasticity. Many researchers have investigated how the synaptic depression affects the memory storage capacity. However, the noise has not been taken into consideration in their analysis. By introducing ``temperature'', which controls the level of the noise, into an update rule of neurons, we investigate the effects of synaptic depression on the memory storage capacity in the presence of the noise. We analytically compute the storage capacity by using a statistical mechanics technique called Self Consistent Signal to Noise Analysis (SCSNA). We find that the synaptic depression decreases the storage capacity in the case of finite temperature in contrast to the case of the low temperature limit, where the storage capacity does not change.

  6. Cushing-type ectopic pituitary adenoma with unusual pathologic features

    Directory of Open Access Journals (Sweden)

    Kristopher T. Kimmell, MD

    2014-06-01

    Full Text Available Ectopic pituitary adenomas comprise, by varying reports, approximately 1-2% of all pituitary adenomas. They are often located in the nasopharyngeal region associated with the pharyngeal pituitary. The location and pathologic features of these masses make them atypical when compared with intrasellar pituitary adenomas. A 54-year-old man presented with vertebral compression fracture and physical stigmata of Cushing’s disease. Biochemical testing confirmed hypercortisolemia responsive to high dose dexamethasone suppression. MRI of the head demonstrated an enhancing mass in the posterior aspect of the sphenoid sinus not involving the sella turcica. Endoscopic biopsy followed by resection confirmed this mass to be a pituitary adenoma with unusual pathologic features. Most notably, the tumor cells demonstrated large, eosinophilic, vacuolated cytoplasm. Immunohistochemical profile of the tumor was typical of an ACTH secreting tumor, notably with positivity for ACTH. The patient did well from his surgery. Post-operatively his serum cortisol level normalized and he remains in chemical remission one year after surgery. Ectopic pituitary adenomas are an unusual manifestation of hormonally active pituitary neoplastic disease. Their atypical clinical presentations, location, and pathologic features can make them a diagnostic challenge. Clinicians should be aware of these entities, especially when considering differential diagnosis for a mass in the sphenoid sinus and nasopharyngeal region.

  7. A Case of Ectopic Parathyroid Adenoma at an Unexpected Location

    Directory of Open Access Journals (Sweden)

    Halil ibrahim Tasci

    2015-03-01

    Full Text Available Ectopic parathyroid tissue can be seen at any location from the mandibula to the mediastinum. The main problem in parathyroid surgery are determination of these ectopic parathyroid tissues' location and their resection. About 1-2% of patients with hyperparathyroidism have a deep mediastinal located parathyroid and transsternal or transthoracic approach should have to be employed most of the time. A 63-year-old female patient, presenting with widespread joint pain and fatigue complaints going on for about a year, was diagnosed with parathyroid adenoma in the mediastinal area as shown by the results of analyses conducted upon the detection of high levels of calcium and parathormone. Accordingly she was taken into surgery with a cervical incision and adenoma in a posterior localization in the carotid artery sheath on the upper mediastinum was seen. The patient, whose calcium, phosphor, and parathormone levels returned to normal levels following the surgery, was discharged with no problems on post-op day 2. Consequently, parathyroid is a tissue whose atypical localization is quite frequent. Nevertheless, atypical localized parathyroid surgeries can be performed by experienced surgeons without having to resort to a secondary procedure with minimally invasive methods with the contribution of localization studies before and/or during the procedure. [Cukurova Med J 2015; 40(Suppl 1: 127-130

  8. Domain walls dynamics in the amorphous ribbon with a helical magnetic anisotropy

    International Nuclear Information System (INIS)

    Zhmetko, D.N.; Savin, V.V.; Lemish, P.V.; Troschenkov, Y.N.

    2006-01-01

    The damping mechanism for motion of domain walls, which form the sandwich structure and move from the middle plane of the ribbon to opposite surfaces during the dynamic magnetization reversal, have been investigated. The difference between the real and ideal sandwich domain structure, the actual distribution of the anisotropy easy directions through the ribbon thickness and the M-bar s deviation from local easy directions under the action of applied magnetic field have been taken into account. It was revealed that the maximum of the total damping coefficient β tot (x) near the half-way of the domain wall run is due to the influence of the magnetic stray fields. These fields have a character of irregular oscillations and are directed approximately perpendicular to the local easy direction of the ribbon layer through which the domain wall propagates. The damping coefficient β e.c. (x) determined by eddy-currents has the maximal value close to the ribbon middle and decreases linearly to zero when the domain wall approaches the ribbon surface

  9. Mena-GRASP65 interaction couples actin polymerization to Golgi ribbon linking.

    Science.gov (United States)

    Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

    2016-01-01

    In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. © 2016 Tang et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  10. Ultrafast Synaptic Events in a Chalcogenide Memristor

    Science.gov (United States)

    Li, Yi; Zhong, Yingpeng; Xu, Lei; Zhang, Jinjian; Xu, Xiaohua; Sun, Huajun; Miao, Xiangshui

    2013-04-01

    Compact and power-efficient plastic electronic synapses are of fundamental importance to overcoming the bottlenecks of developing a neuromorphic chip. Memristor is a strong contender among the various electronic synapses in existence today. However, the speeds of synaptic events are relatively slow in most attempts at emulating synapses due to the material-related mechanism. Here we revealed the intrinsic memristance of stoichiometric crystalline Ge2Sb2Te5 that originates from the charge trapping and releasing by the defects. The device resistance states, representing synaptic weights, were precisely modulated by 30 ns potentiating/depressing electrical pulses. We demonstrated four spike-timing-dependent plasticity (STDP) forms by applying programmed pre- and postsynaptic spiking pulse pairs in different time windows ranging from 50 ms down to 500 ns, the latter of which is 105 times faster than the speed of STDP in human brain. This study provides new opportunities for building ultrafast neuromorphic computing systems and surpassing Von Neumann architecture.

  11. Synaptic theory of Replicator-like melioration

    Directory of Open Access Journals (Sweden)

    Yonatan Loewenstein

    2010-06-01

    Full Text Available According to the theory of Melioration, organisms in repeated choice settings shift their choice preference in favor of the alternative that provides the highest return. The goal of this paper is to explain how this learning behavior can emerge from microscopic changes in the efficacies of synapses, in the context of two-alternative repeated-choice experiment. I consider a large family of synaptic plasticity rules in which changes in synaptic efficacies are driven by the covariance between reward and neural activity. I construct a general framework that predicts the learning dynamics of any decision-making neural network that implements this synaptic plasticity rule and show that melioration naturally emerges in such networks. Moreover, the resultant learning dynamics follows the Replicator equation which is commonly used to phenomenologically describe changes in behavior in operant conditioning experiments. Several examples demonstrate how the learning rate of the network is affected by its properties and by the specifics of the plasticity rule. These results help bridge the gap between cellular physiology and learning behavior.

  12. Dynamic Control of Synaptic Adhesion and Organizing Molecules in Synaptic Plasticity

    Energy Technology Data Exchange (ETDEWEB)

    Rudenko, Gabby (Texas-MED)

    2017-01-01

    Synapses play a critical role in establishing and maintaining neural circuits, permitting targeted information transfer throughout the brain. A large portfolio of synaptic adhesion/organizing molecules (SAMs) exists in the mammalian brain involved in synapse development and maintenance. SAMs bind protein partners, formingtrans-complexes spanning the synaptic cleft orcis-complexes attached to the same synaptic membrane. SAMs play key roles in cell adhesion and in organizing protein interaction networks; they can also provide mechanisms of recognition, generate scaffolds onto which partners can dock, and likely take part in signaling processes as well. SAMs are regulated through a portfolio of different mechanisms that affect their protein levels, precise localization, stability, and the availability of their partners at synapses. Interaction of SAMs with their partners can further be strengthened or weakened through alternative splicing, competing protein partners, ectodomain shedding, or astrocytically secreted factors. Given that numerous SAMs appear altered by synaptic activity, in vivo, these molecules may be used to dynamically scale up or scale down synaptic communication. Many SAMs, including neurexins, neuroligins, cadherins, and contactins, are now implicated in neuropsychiatric and neurodevelopmental diseases, such as autism spectrum disorder, schizophrenia, and bipolar disorder and studying their molecular mechanisms holds promise for developing novel therapeutics.

  13. Characterization and extraction of the synaptic apposition surface for synaptic geometry analysis

    Science.gov (United States)

    Morales, Juan; Rodríguez, Angel; Rodríguez, José-Rodrigo; DeFelipe, Javier; Merchán-Pérez, Angel

    2013-01-01

    Geometrical features of chemical synapses are relevant to their function. Two critical components of the synaptic junction are the active zone (AZ) and the postsynaptic density (PSD), as they are related to the probability of synaptic release and the number of postsynaptic receptors, respectively. Morphological studies of these structures are greatly facilitated by the use of recent electron microscopy techniques, such as combined focused ion beam milling and scanning electron microscopy (FIB/SEM), and software tools that permit reconstruction of large numbers of synapses in three dimensions. Since the AZ and the PSD are in close apposition and have a similar surface area, they can be represented by a single surface—the synaptic apposition surface (SAS). We have developed an efficient computational technique to automatically extract this surface from synaptic junctions that have previously been three-dimensionally reconstructed from actual tissue samples imaged by automated FIB/SEM. Given its relationship with the release probability and the number of postsynaptic receptors, the surface area of the SAS is a functionally relevant measure of the size of a synapse that can complement other geometrical features like the volume of the reconstructed synaptic junction, the equivalent ellipsoid size and the Feret's diameter. PMID:23847474

  14. Ectopic osteoid and bone formation by three calcium-phosphate ceramics in rats, rabbits and dogs

    NARCIS (Netherlands)

    Wang, Liao; Zhang, B.; Bao, Chongyun; Habibovic, Pamela; Hu, J.; Zhang, Xingdong

    2014-01-01

    Calcium phosphate ceramics with specific physicochemical properties have been shown to induce de novo bone formation upon ectopic implantation in a number of animal models. In this study we explored the influence of physicochemical properties as well as the animal species on material-induced ectopic

  15. Immunohistological demonstration of intermediate trophoblast in the diagnosis of uterine versus ectopic pregnancy

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt; Marcussen, N; Daugaard, H O

    1991-01-01

    . The histological presence and distribution of hPL was investigated in endometrial curettings from 90 patients studied retrospectively (47 had ectopic pregnancies, 14 miscarriages, and 29 legal abortions), and a consecutive, prospective series of 50 patients (40 had miscarriages and 10 had ectopic pregnancies...

  16. Management of paroxysmal ectopic atrial tachycardia with long sinus pauses in a teenager

    OpenAIRE

    Seshadri Balaji

    2015-01-01

    Sinus pauses in the setting of supraventricular tachycardia is rare in children. We describe an asymptomatic teen with irregular heart rate detected during an incidental exam who was found to have short runs of a slow ectopic atrial tachycardia on electrocardiogram and prolonged sinus pauses on routine ambulatory ECG. Successful catheter ablation of the ectopic atrial tachycardia led to resolution of the sinus pauses.

  17. Diagnosis of Unilateral Single System Ectopic Ureter in Girls in the ...

    African Journals Online (AJOL)

    Objective: The ectopic ureter frequently drains an ectopic dysplastic or hypoplastic kidney. The present study aims at defining the role of MRU in establishing the diagnosis of this anomaly. Patients and Methods: Between February 1996 and March 2000, 11 girls presented or were referred to our department for management ...

  18. Orthodontic treatment of a stubborn palatally ectopic canine: a case report.

    Science.gov (United States)

    Al-Musfir, Tumadher M; Morris, David O

    2014-03-01

    This is a case report that highlights a different treatment approach in dealing with palatally ectopic canines. The modified transpalatal arch with an 'active' arm was used to align a palatally ectopic canine with 'push' mechanics after the initial use of more conventional 'pull' mechanics (piggy-back archwire technique) had failed.

  19. MRI Findings of Coexistence of Ectopic Neurohypophysis, Corpus Callosum Dysgenesis, and Periventricular Neuronal Heterotopia

    Directory of Open Access Journals (Sweden)

    Harun Arslan

    2014-01-01

    Full Text Available Ectopic neurohypophysis is a pituitary gland abnormality, which can accompany growth hormone deficiency associated with dwarfism. Here we present magnetic resonance imaging (MRI findings of a rare case of ectopic neurohypophysis, corpus callosum dysgenesis, and periventricular neuronal heterotopia coexisting, with a review of the literature.

  20. Fibroadenoma of ectopic breast tissue of the axilla in an adolescent ...

    African Journals Online (AJOL)

    Ectopic breast tissue (EBT) is a well-described entity in the English literature. However, fibroadenoma of the ectopic breast is a rare entity. We present a case of a 13-year-old adolescent girl with a subcutaneous mass in the right axilla that was pathologically identical to fibroadenoma seen in the EBT. To our knowledge, this ...

  1. Detection of chromosome abnormalities by quantitative fluorescent PCR in ectopic pregnancies

    NARCIS (Netherlands)

    Goddijn, Mariette; van Stralen, Marja; Schuring-Blom, Heleen; Redeker, Bert; van Leeuwen, Liesbeth; Repping, Sjoerd; Leschot, Nico; van der Veen, Fulco

    2005-01-01

    Objective: To evaluate the potential value of quantitative fluorescent polymerase chain reaction (QF-PCR) in the detection of chromosome abnormalities in ectopic pregnancies. Methods: Seventy chorionic villi samples of ectopic pregnancies were studied by QF-PCR. Primers for chromosomes 16, 21, X and

  2. 42 CFR 136a.55 - Drugs and devices and termination of ectopic pregnancies.

    Science.gov (United States)

    2010-10-01

    ... and devices and termination of ectopic pregnancies. Federal funds are available for drugs or devices... 42 Public Health 1 2010-10-01 2010-10-01 false Drugs and devices and termination of ectopic pregnancies. 136a.55 Section 136a.55 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN...

  3. 42 CFR 136.55 - Drugs and devices and termination of ectopic pregnancies.

    Science.gov (United States)

    2010-10-01

    ... devices and termination of ectopic pregnancies. Federal funds are available for drugs or devices to... 42 Public Health 1 2010-10-01 2010-10-01 false Drugs and devices and termination of ectopic pregnancies. 136.55 Section 136.55 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN...

  4. 42 CFR 441.207 - Drugs and devices and termination of ectopic pregnancies.

    Science.gov (United States)

    2010-10-01

    ... APPLICABLE TO SPECIFIC SERVICES Abortions § 441.207 Drugs and devices and termination of ectopic pregnancies... 42 Public Health 4 2010-10-01 2010-10-01 false Drugs and devices and termination of ectopic pregnancies. 441.207 Section 441.207 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF...

  5. Low-frequency magnetization processes in chemically etched Co-based amorphous ribbons

    International Nuclear Information System (INIS)

    Betancourt, I.; Martinez, L.A.; Valenzuela, R.

    2005-01-01

    In this report we present a study of the magnetization processes for Co-based amorphous ribbons at low frequencies (10 Hz-13 MHz) as a function of decreasing thicknesses attained by chemical etching. Reversible domain-wall bulging, characterized by initial permeability and relaxation frequency, was monitored by means of inductance measurements. The real part of inductance (proportional to initial permeability) exhibited a decreasing trend with diminishing ribbon thickness, together with an increasing tendency for the relaxation frequency. For high amplitude of the ac field (leading to domain-wall unpinning), reduced ribbon thickness showed a deleterious-enhancement effect on irreversible domain-wall displacement, which was observed for both real and imaginary inductance spectroscopic plots. Results are interpreted in terms of reduced domain-wall pinning distances resulting from thinner alloy samples

  6. Mechanical properties of metallic ribbons investigated by depth sensing indentation technique

    International Nuclear Information System (INIS)

    Pesek, Ladislav; Dobrzanski, Leszek A.; Zubko, Pavol; Konieczny, Jaroslaw

    2006-01-01

    The paper presents mechanical properties of two kinds of Co-based and one Fe-based metallic ribbons by the depth sensing indentation (DSI) technique. Investigations were carried out on two kinds ternary alloy Co 77 Si 11,5 B 11,5 and Fe 78 Si 13 B 9 and multicomponent Co 68 Fe 4 Mo 1 Si 13,5 B 13,5 , which are so-called 'zero-magnetostriction' materials. Metallic ribbons were investigated in amorphous state and partially crystallized state after annealing in 400deg. C in argon atmosphere. Heating of ribbons obtained by melt spinning technique was performed to check its effect on changes of mechanical properties

  7. ANALYSIS OF RIBBONING ON CONICAL YARN PACKAGE WOUND BY OPENEND SPINNING MACHINES

    Directory of Open Access Journals (Sweden)

    Resul FETTAHOV

    2001-03-01

    Full Text Available In this paper, Ribboning , one of the common faults in yarn packages, is mathematically analysed. If yarn is repeatly laid on top of or along the same path as the previously wound yarn, this duplication of yarn path on the package creates a defect known as ribboning. The number of turns of package (n per double traverse of yarn guide is calculated in two different way One is calculated the length of a coil on the package and total length of yarn in a double traverse; the other is considered transmission rate between drum and conical yarn package The result of two different approach is similar and the probable diameter of conical yarn package which ribboning is occurred is calculated and used on Schalafhorst-Autocore OE spinning machines.

  8. THE SURFACE STRUCTURAL AND MECHANICAL PROPERTIES OF THE AMORPHOUS CO22Y54AL24 RIBBON

    Directory of Open Access Journals (Sweden)

    Anna Bukowska

    2013-09-01

    Full Text Available The aim of this study was to manufacture amorphous Co22Y54Al24 alloy in a form of thin ribbons and to investigate their properties. The investigated ribbons were prepared by rapid solidification of molten metal on a rotating copper cylinder (melt-spinning. In order to obtain the material with amorphous structure, the cooling rate of the liquid alloy should vary in a range from 104 to 106 K/s. The microstructure studies were performed using X-ray diffractometery. The mechanical properties were investigated by metallographic studies, micro-hardness and tribological resistance tests moreover the surface roughness profile were analyzed. All studies were performed for two sides of tapes, since the differences in ribbons surface, related with manufacturing process, are clearly visible. The surface from the bottom (drum side was glossy and from the top side it was shiny.

  9. Release from the cone ribbon synapse under bright light conditions can be controlled by the opening of only a few Ca(2+) channels.

    Science.gov (United States)

    Bartoletti, Theodore M; Jackman, Skyler L; Babai, Norbert; Mercer, Aaron J; Kramer, Richard H; Thoreson, Wallace B

    2011-12-01

    Light hyperpolarizes cone photoreceptors, causing synaptic voltage-gated Ca(2+) channels to open infrequently. To understand neurotransmission under these conditions, we determined the number of L-type Ca(2+) channel openings necessary for vesicle fusion at the cone ribbon synapse. Ca(2+) currents (I(Ca)) were activated in voltage-clamped cones, and excitatory postsynaptic currents (EPSCs) were recorded from horizontal cells in the salamander retina slice preparation. Ca(2+) channel number and single-channel current amplitude were calculated by mean-variance analysis of I(Ca). Two different comparisons-one comparing average numbers of release events to average I(Ca) amplitude and the other involving deconvolution of both EPSCs and simultaneously recorded cone I(Ca)-suggested that fewer than three Ca(2+) channel openings accompanied fusion of each vesicle at the peak of release during the first few milliseconds of stimulation. Opening fewer Ca(2+) channels did not enhance fusion efficiency, suggesting that few unnecessary channel openings occurred during strong depolarization. We simulated release at the cone synapse, using empirically determined synaptic dimensions, vesicle pool size, Ca(2+) dependence of release, Ca(2+) channel number, and Ca(2+) channel properties. The model replicated observations when a barrier was added to slow Ca(2+) diffusion. Consistent with the presence of a diffusion barrier, dialyzing cones with diffusible Ca(2+) buffers did not affect release efficiency. The tight clustering of Ca(2+) channels, along with a high-Ca(2+) affinity release mechanism and diffusion barrier, promotes a linear coupling between Ca(2+) influx and vesicle fusion. This may improve detection of small light decrements when cones are hyperpolarized by bright light.

  10. Imaging examinations and diagnosis of children's ectopic uretal aperture (with a review of 68 cases)

    International Nuclear Information System (INIS)

    Zhai Jiankun; Liu Liwei

    2004-01-01

    Objective: To discuss the imaging findings and examination methods of ectopic uretal aperture in children. Methods: The clinical data, imaging methods and findings of 68 cases with ectopic uretal aperture were analyzed retrospectively. Results: In 44 cases ectopic uretal aperture were associated with duplex kidneys (DK), and in 24 cases ectopic uretal aperture were associated with dysplasia of kidneys. IVU could display direct or indirect signs of DK in all cases. While it could hardly display dysplastic kidney and ectopic uretal aperture. CT scans were performed in 8 patients, in which DK, dysplastic kidney and the draining ureters could be evaluated. Conclusion: Definitive diagnosis is made in most cases with the integrating the clinical information and IVU findings. However, CT scan is recommended in a few cases

  11. Clinical Significance of Monitoring Serum β-HCG in the Conservative Treatment of Ectopic Pregnancy

    International Nuclear Information System (INIS)

    Chen Xue

    2010-01-01

    To explore the clinical value of the serum β-HCG (human chorionic gonadotrophin) in the conservative treatment of ectopic pregnancy, the serum β-HCG levels in 118 patients with ectopic pregnancy were measured with RIA. The results showed that the serum β-HCG levels in patients with successful conservative treatment of ectopic pregnancy were all less than 200mIU/mL. The patients require a surgical treatment to reach <200mIU/mL serum β-HCG concentration were only 26.3%. There was significant difference between two groups (P<0.01). The monitoring of serum β-HCG was very useful in the diagnosis, the choice of treatment measures and the evaluation of conservative treatment effect of ectopic pregnancy. In the course of treatment of ectopic pregnancy, serum β-HCG is a good marker in determining the success or failure of treatment. (authors)

  12. A Rare Case of Chronic Ectopic Pregnancy Presenting as Large Hematosalpinx

    Directory of Open Access Journals (Sweden)

    Madhavi Nacharaju

    2014-01-01

    Full Text Available Ectopic pregnancy is defined as implantation and subsequent development of an embryo outside the uterine lining. It has wide range of presentation from acute hemoperitoneum to chronic ectopic pregnancy. This is an unusual case of chronic ectopic pregnancy with large hematosalpinx without classical symptoms. A 22-year-old South Indian woman reported to the outpatient clinic with irregular spotting for a duration of 2 months which was not associated with pain. There was no preceding amenorrhea and previous menstrual cycles were regular. Clinically, the patient was hemodynamically stable but severely anemic. The abdomen was soft on palpation, cervical movements were not tender, and human chorionic gonadotropin was absent in the urine. Ultrasound revealed a complex adnexal mass. Magnetic resonance imaging (MRI revealed a large hematosalpinx. Laparoscopic left salpingectomy was conducted and histopathology confirmed ectopic pregnancy. Ectopic pregnancy presents diagnostic dilemmas in the absence of classical symptoms. MRI and laparoscopy are important tools in such a diagnostic dilemma.

  13. A new dental powder from nanocrystalline melt-spun Ag-Sn-Cu alloy ribbons

    International Nuclear Information System (INIS)

    Do-Minh, N.; Le-Thi, C.; Nguyen-Anh, S.

    2003-01-01

    A new non-gamma-two dental powder has been developed from nanocrystalline melt-spun Ag-Sn-Cu alloy ribbons. The amalgam made from this powder exhibits excellent properties for dental filling. The nanocrystalline microstructure was found for the first time in as-spun and heat treated Ag(27-28)Sn(9-32) Cu alloy ribbons, using X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. As-spun ribbons exhibited a multi-phase microstructure with preferred existence of β (Ag 4 Sn) phase formed during rapid solidification (RS) due to supersaturating of copper (Cu) atoms and homogenous nanostructure with subgrain size of about (40-50) nm, which seems to be developed during RS process and can be caused by eutectic reaction of the Ag 3 Sn/Ag 4 Sn-Cu 3 Sn system. In heat treated ribbons the clustering of Cu atoms was always favored and stable in an ageing temperature and time interval determined by Cu content. The heat treatment led to essential changes of subgrain morphology, resulted in the appearance of large-angle boundaries with fine Cu 3 Sn precipitates and forming typical recrystallization twins. Such a microstructure variation in melt-spun ribbons could eventually yield enhanced technological, clinical and physical properties of the dental products, controlled by the ADA Specification N deg 1 and reported before. Thus, using the rapid solidification technique a new non-gamma-two dental material of high quality, nanocrystalline ribbon powder, can be produced. Copyright (2003) AD-TECH - International Foundation for the Advancement of Technology Ltd

  14. OBSERVATIONS OF AN X-SHAPED RIBBON FLARE IN THE SUN AND ITS THREE-DIMENSIONAL MAGNETIC RECONNECTION

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Ding, M. D.; Yang, K. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Qiu, J.; Longcope, D. W., E-mail: yingli@nju.edu.cn [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2016-05-20

    We report evolution of an atypical X-shaped flare ribbon that provides novel observational evidence of three-dimensional (3D) magnetic reconnection at a separator. The flare occurred on 2014 November 9. High-resolution slit-jaw 1330 Å images from the Interface Region Imaging Spectrograph reveal four chromospheric flare ribbons that converge and form an X-shape. Flare brightening in the upper chromosphere spreads along the ribbons toward the center of the “X” (the X-point), and then spreads outward in a direction more perpendicular to the ribbons. These four ribbons are located in a quadrupolar magnetic field. Reconstruction of magnetic topology in the active region suggests the presence of a separator connecting to the X-point outlined by the ribbons. The inward motion of flare ribbons in the early stage therefore indicates 3D magnetic reconnection between two sets of non-coplanar loops that approach laterally, and reconnection proceeds downward along a section of vertical current sheet. Coronal loops are also observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory confirming the reconnection morphology illustrated by ribbon evolution.

  15. Laparoscopy-Assisted Billroth I Gastrectomy for Ectopic Pancreas in the Prepyloric Region

    Directory of Open Access Journals (Sweden)

    Yueh-Tsung Lee

    2012-11-01

    Full Text Available Ectopic pancreatic tissue is an uncommon developmental anomaly. The condition mostly occurs in the gastrointestinal tract and is usually asymptomatic. It rarely causes symptoms of inflammation, bleeding and perforation, and has potential for malignant change. Though it is an uncommon condition, cases of ectopic pancreas have been reported worldwide. Preoperative diagnosis of ectopic pancreas is challenging because of its nonspecific symptoms and signs. Owing to the revolution of minimally invasive surgery, submucosal tumors of the stomach can be resected by laparoscopic techniques. We have earlier reported on a case of ectopic pancreas in the stomach treated by robotics-assisted laparoscopic wedge resection. Herein, we report a case of ectopic pancreas in the prepyloric region of the stomach. A 44-year-old female presented with a two-week history of epigastralgia with radiation to the back. She received endoscopy check-up which disclosed a mass in the stomach. By endoscopic findings, a submucosal lesion in the prepyloric region with umbilical folding on the mucosa was identified. The umbilical folding on the mucosa hint the orifice of the duct of ectopic pancreas into the gastric mucosa suggestive of ectopic pancreas. Contrast-enhanced abdominal computed tomography showed a 5 cm cystic mass with heterogeneous content. To sum it up, the patient was diagnosed as ectopic pancreas in the stomach. She underwent laparoscopy-assisted antrectomy with Billroth I anastomosis (excision of the antrum and prepyloric region with reconstruction of gastrointestinal continuity by gastroduodenostomy and had an uneventful hospitalization course. The histopathology of the resected tumor demonstrated ectopic pancreatic tissue in the gastric wall. To the best of our knowledge, excision of gastric ectopic pancreas using laparoscopy-assisted antrectomy with Billroth I anastomosis has never been reported in the literature.

  16. FLARE RIBBON ENERGETICS IN THE EARLY PHASE OF AN SDO FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, L.; Hannah, I. G.; Hudson, H. S. [School of Physics and Astronomy, SUPA, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Innes, D. E. [Max Planck Institute for Solar System Research, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau (Germany)

    2013-07-10

    The sites of chromospheric excitation during solar flares are marked by extended extreme ultraviolet ribbons and hard X-ray (HXR) footpoints. The standard interpretation is that these are the result of heating and bremsstrahlung emission from non-thermal electrons precipitating from the corona. We examine this picture using multi-wavelength observations of the early phase of an M-class flare SOL2010-08-07T18:24. We aim to determine the properties of the heated plasma in the flare ribbons, and to understand the partition of the power input into radiative and conductive losses. Using GOES, SDO/EVE, SDO/AIA, and RHESSI, we measure the temperature, emission measure (EM), and differential emission measure of the flare ribbons, and deduce approximate density values. The non-thermal EM, and the collisional thick target energy input to the ribbons are obtained from RHESSI using standard methods. We deduce the existence of a substantial amount of plasma at 10 MK in the flare ribbons, during the pre-impulsive and early-impulsive phase of the flare. The average column EM of this hot component is a few times 10{sup 28} cm{sup -5}, and we can calculate that its predicted conductive losses dominate its measured radiative losses. If the power input to the hot ribbon plasma is due to collisional energy deposition by an electron beam from the corona then a low-energy cutoff of {approx}5 keV is necessary to balance the conductive losses, implying a very large electron energy content. Independent of the standard collisional thick-target electron beam interpretation, the observed non-thermal X-rays can be provided if one electron in 10{sup 3}-10{sup 4} in the 10 MK (1 keV) ribbon plasma has an energy above 10 keV. We speculate that this could arise if a non-thermal tail is generated in the ribbon plasma which is being heated by other means, for example, by waves or turbulence.

  17. Numerical Study of the influence of a ribbon geometry of experiment on measuring particle angular distributions

    International Nuclear Information System (INIS)

    Artemov, A.S.

    1996-01-01

    The values and nature of systematic errors in small-angle particle scattering experiments using ribbon-like beams are investigated by numerical simulation. As shown, the extent of the influence of a ribbon geometry of experiment on the result of measurement is significantly dependent on the shape of the measured angular distribution in an elementary act of interaction. The algorithm of experimental material treatment, obtained in measuring the widths at half maximum of the angular differential cross sections of secondary particles, is presented using an example of specific distributions and certain experimental setup. (author). 12 refs., 7 figs

  18. SPECTROSCOPIC OBSERVATIONS OF AN EVOLVING FLARE RIBBON SUBSTRUCTURE SUGGESTING ORIGIN IN CURRENT SHEET WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, S. R.; Longcope, D. W.; Qiu, J. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2015-09-01

    We present imaging and spectroscopic observations from the Interface Region Imaging Spectrograph of the evolution of the flare ribbon in the SOL2014-04-18T13:03 M-class flare event, at high spatial resolution and time cadence. These observations reveal small-scale substructure within the ribbon, which manifests as coherent quasi-periodic oscillations in both position and Doppler velocities. We consider various alternative explanations for these oscillations, including modulation of chromospheric evaporation flows. Among these, we find the best support for some form of wave localized to the coronal current sheet, such as a tearing mode or Kelvin–Helmholtz instability.

  19. Gettering effects in RAD polysilicon ribbons: An XPS/AES study

    Energy Technology Data Exchange (ETDEWEB)

    Amarray, E.; Deville, J.P.; Quesada, J.

    1987-03-01

    Evidence for gettering effects during the various heat treatments applied to RAD ribbons were investigated with surface analysis methods. These heat treatments occur either during the burning-off process of the carbon support or during the POCl/sub 3/ diffusion, and transport metallic impurities near the surface of the sample. Oxidation of clean silicon surfaces, cleaved either in air or ultra-high vacuum, has shown that the same metallic impurities are brought near the surface by this treatment alone. It is thus suggested that controlled oxidations and heat treatments can be used to improve the electrical properties of polysilicon, and especially of ribbons.

  20. The Blue Ribbon Commission and siting radioactive waste disposal facilities

    International Nuclear Information System (INIS)

    Pescatore, C.

    2010-01-01

    On 21 September 2010, the NEA Secretariat was invited to address the Blue Ribbon Commission on America's Nuclear Future. This paper is a summary of the remarks made. The successful siting of radioactive waste disposal facilities implies creating the conditions for continued ownership of the facility over time. Acceptance of the facility at a single point in time is not good enough. Continued ownership implies the creation of conscious, constructive and durable relationships between the (most affected) communities and the waste management facility. Being comfortable about the technical safety of the facility requires a degree of familiarity and control . Having peace of mind about the safety of the facility requires trust in the waste management system and its actors as well as some control over the decision making. Regulators are especially important players who need to be visible in the community. The ideal site selection process should be step- wise, combining procedures for excluding sites that do not meet pre-identified criteria with those for identifying sites where nearby and more distant residents are willing to discuss acceptance of the facility. The regional authorities are just as important as the local authorities. Before approaching a potential siting region or community, there should be clear results of national (and state) debates establishing the role of nuclear power in the energy mix, as well as information on the magnitude of the ensuing waste commitment and its management end-points, and the allocation of the financial and legal responsibilities until the closure of the project. Once the waste inventories and type of facilities have been decided upon, there should be agreement that all significant changes will require a new decision-making process. Any proposed project has a much better chance to move forward positively if the affected populations can participate in its definition, including, at the appropriate time, its technical details. A

  1. Mechanisms of glycine release, which build up synaptic and extrasynaptic glycine levels: the role of synaptic and non-synaptic glycine transporters.

    Science.gov (United States)

    Harsing, Laszlo G; Matyus, Peter

    2013-04-01

    Glycine is an amino acid neurotransmitter that is involved in both inhibitory and excitatory neurochemical transmission in the central nervous system. The role of glycine in excitatory neurotransmission is related to its coagonist action at glutamatergic N-methyl-D-aspartate receptors. The glycine levels in the synaptic cleft rise many times higher during synaptic activation assuring that glycine spills over into the extrasynaptic space. Another possible origin of extrasynaptic glycine is the efflux of glycine occurring from astrocytes associated with glutamatergic synapses. The release of glycine from neuronal or glial origins exhibits several differences compared to that of biogenic amines or other amino acid neurotransmitters. These differences appear in an external Ca(2+)- and temperature-dependent manner, conferring unique characteristics on glycine as a neurotransmitter. Glycine transporter type-1 at synapses may exhibit neural and glial forms and plays a role in controlling synaptic glycine levels and the spill over rate of glycine from the synaptic cleft into the extrasynaptic biophase. Non-synaptic glycine transporter type-1 regulates extrasynaptic glycine concentrations, either increasing or decreasing them depending on the reverse or normal mode operation of the carrier molecule. While we can, at best, only estimate synaptic glycine levels at rest and during synaptic activation, glycine concentrations are readily measurable via brain microdialysis technique applied in the extrasynaptic space. The non-synaptic N-methyl-D-aspartate receptor may obtain glycine for activation following its spill over from highly active synapses or from its release mediated by the reverse operation of non-synaptic glycine transporter-1. The sensitivity of non-synaptic N-methyl-D-aspartate receptors to glutamate and glycine is many times higher than that of synaptic N-methyl-D-aspartate receptors making the former type of receptor the primary target for drug action. Synaptic

  2. Large Area Silicon Sheet by EFG. [quality control and productivity of edge-defined film-fed growth of ribbons

    Science.gov (United States)

    1979-01-01

    Influences on ribbon quality which might be caused by various materials of construction which are used in the growth furnace were assessed. At the present level of ribbon quality, which has produced 8.5% to 9.5% efficient solar cells, no particular influence of any furnace part was detected. The experiments led to the suspicion that the general environment and the somewhat unoptimized materials handling procedures might be responsible for the current variations in ribbon quality and that, therefore, continuous work with this furnace under rather more stringent environmental conditions and operating procedures could perhaps improve materials quality to some extent. The work on the multiple furnace was continued with two multiple growth runs being performed. In these runs, the melt replenishment system performed poorly and extensive modifications to it were designed to make reliable melt feeding for five ribbon growth possible. Additional characterization techniques for wide ribbons, stress measurements, and growth dynamics experiments are reported.

  3. Ectopic pregnancy in a Caesarean section scar: a case study

    Directory of Open Access Journals (Sweden)

    Piotr Niziurski

    2013-08-01

    Full Text Available Implantation of a pregnancy in a scar after Caesarean section is one of the rarest locations of ectopic pregnancies. A diagnosis and/or treatment which is too late may lead to a uterine rupture, the necessity to remove the uterus and a significant increase in morbidity among mothers. The study presents a diagnostically difficult case of a 29-year-old woman, who was diagnosed with pregnancy in its seventh week, located in a scar after a Caesarean section, with highly increased values of human chorionic gonadotropin (β-HCG concentration in blood serum. The pregnancy was removed and the wound was stitched during laparotomy, without a need to remove the uterus.

  4. Ectopic fat accumulation in patients with COPD: an ECLIPSE substudy

    Directory of Open Access Journals (Sweden)

    Martin M

    2017-01-01

    Full Text Available Mickaël Martin,1 Natalie Almeras,1 Jean-Pierre Després,1 Harvey O Coxson,2 George R Washko,3 Isabelle Vivodtzev,4 Emiel FM Wouters,5 Erica Rutten,6 Michelle C Williams,7 John T Murchison,8 William MacNee,7 Don D Sin,2 François Maltais1 On behalf of the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE Study Group 1Research Centre, Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, 2Department of Radiology, University of British Columbia, Vancouver, BC, Canada; 3Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA; 4Hypoxia Pathophysiology Laboratory, Grenoble University Hospital, Grenoble, France; 5Department of Respiratory Medicine, Maastricht University Medical Center, Maastricht, 6Research and Development, CIRO, Horn, the Netherlands; 7Department of Respiratory Medicine, University of Edinburgh, 8Department of Radiology, Royal Infirmary of Edinburgh, Edinburgh, UK Background: Obesity is increasingly associated with COPD, but little is known about the prevalence of ectopic fat accumulation in COPD and whether this can possibly be associated with poor clinical outcomes and comorbidities. The Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE substudy tested the hypothesis that COPD is associated with increased ectopic fat accumulation and that this would be associated with COPD-related outcomes and comorbidities.Methods: Computed tomography (CT images of the thorax obtained in ECLIPSE were used to quantify ectopic fat accumulation at L2–L3 (eg, cross-sectional area [CSA] of visceral adipose tissue [VAT] and muscle tissue [MT] attenuation, a reflection of muscle fat infiltration and CSA of MT. A dose–response relationship between CSA of VAT, MT attenuation and CSA of MT and COPD-related outcomes (6-minute walking distance [6MWD], exacerbation rate, quality of life, and forced

  5. Imaging in covert ectopic ACTH secretion: a CT pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Sookur, Paul A.; Sahdev, Anju; Rockall, Andrea G.; Reznek, Rodney H. [St Bartholomew' s Hospital, Department of Academic Radiology, Dominion House, London (United Kingdom); Isidori, Andrea M. [Sapienza University of Rome, Department of Medical Pathophysiology, Rome (Italy); Monson, John P.; Grossman, Ashley B. [St Bartholomew' s Hospital, Department of Endocrinology, London (United Kingdom)

    2009-05-15

    The syndrome of ectopic adrenocorticotrophin secretion (EAS) is rare and is due to excess adrenocorticotrophin (ACTH) production from a nonpituitary tumour. These tumours can be covert, where the tumours are not readily apparent, and very small making them challenging to image. It is clinically and biochemically difficult to distinguish between covert EAS and Cushing's disease. The first-line investigation in locating the source of ACTH production is computed tomography (CT). The aim of this pictorial review is to illustrate the likely covert sites and related imaging findings. We review the CT appearances of tumours resulting in covert EAS and the associated literature. The most common tumours were bronchial carcinoid tumours, which appear as small, well-defined, round or ovoid pulmonary lesions. Rarer causes included thymic carcinoids, gastrointestinal carcinoids and pancreatic neuroendocrine tumours. Awareness of the imaging characteristics will aid identification of the source of ACTH production and allow potentially curative surgical resection. (orig.)

  6. FAM20A Gene Mutation: Amelogenesis or Ectopic Mineralization?

    Directory of Open Access Journals (Sweden)

    Guilhem Lignon

    2017-05-01

    Full Text Available Background and objective:FAM20A gene mutations result in enamel renal syndrome (ERS associated with amelogenesis imperfecta (AI, nephrocalcinosis, gingival fibromatosis, and impaired tooth eruption. FAM20A would control the phosphorylation of enamel peptides and thus enamel mineralization. Here, we characterized the structure and chemical composition of unerupted tooth enamel from ERS patients and healthy subjects.Methods: Tooth sections were analyzed by Scanning Electron Microscopy (SEM, Energy Dispersive Spectroscopy (EDS, X-Ray Diffraction (XRD, and X-Ray Fluorescence (XRF.Results: SEM revealed that prisms were restricted to the inner-most enamel zones. The bulk of the mineralized matter covering the crown was formed by layers with varying electron-densities organized into lamellae and micronodules. Tissue porosity progressively increased at the periphery, ending with loose and unfused nanonodules also observed in the adjoining soft tissues. Thus, the enamel layer covering the dentin in all ERS patients (except a limited layer of enamel at the dentino-enamel junction displayed an ultrastructural globular pattern similar to one observed in ectopic mineralization of soft tissue, notably in the gingiva of Fam20a knockout mice. XRD analysis confirmed the existence of alterations in crystallinity and composition (vs. sound enamel. XRF identified lower levels of calcium and phosphorus in ERS enamel. Finally, EDS confirmed the reduced amount of calcium in ERS enamel, which appeared similar to dentin.Conclusion: This study suggests that, after an initial normal start to amelogenesis, the bulk of the tissue covering coronal dentin would be formed by different mechanisms based on nano- to micro-nodule aggregation. This evocated ectopic mineralization process is known to intervene in several soft tissues in FAM20A gene mutant.

  7. FAM20A Gene Mutation: Amelogenesis or Ectopic Mineralization?

    Science.gov (United States)

    Lignon, Guilhem; Beres, Fleur; Quentric, Mickael; Rouzière, Stephan; Weil, Raphael; De La Dure-Molla, Muriel; Naveau, Adrien; Kozyraki, Renata; Dessombz, Arnaud; Berdal, Ariane

    2017-01-01

    Background and objective: FAM20A gene mutations result in enamel renal syndrome (ERS) associated with amelogenesis imperfecta (AI), nephrocalcinosis, gingival fibromatosis, and impaired tooth eruption. FAM20A would control the phosphorylation of enamel peptides and thus enamel mineralization. Here, we characterized the structure and chemical composition of unerupted tooth enamel from ERS patients and healthy subjects. Methods: Tooth sections were analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Diffraction (XRD), and X-Ray Fluorescence (XRF). Results: SEM revealed that prisms were restricted to the inner-most enamel zones. The bulk of the mineralized matter covering the crown was formed by layers with varying electron-densities organized into lamellae and micronodules. Tissue porosity progressively increased at the periphery, ending with loose and unfused nanonodules also observed in the adjoining soft tissues. Thus, the enamel layer covering the dentin in all ERS patients (except a limited layer of enamel at the dentino-enamel junction) displayed an ultrastructural globular pattern similar to one observed in ectopic mineralization of soft tissue, notably in the gingiva of Fam20a knockout mice. XRD analysis confirmed the existence of alterations in crystallinity and composition (vs. sound enamel). XRF identified lower levels of calcium and phosphorus in ERS enamel. Finally, EDS confirmed the reduced amount of calcium in ERS enamel, which appeared similar to dentin. Conclusion: This study suggests that, after an initial normal start to amelogenesis, the bulk of the tissue covering coronal dentin would be formed by different mechanisms based on nano- to micro-nodule aggregation. This evocated ectopic mineralization process is known to intervene in several soft tissues in FAM20A gene mutant.

  8. Synaptic Contacts Enhance Cell-to-Cell Tau Pathology Propagation

    Directory of Open Access Journals (Sweden)

    Sara Calafate

    2015-05-01

    Full Text Available Accumulation of insoluble Tau protein aggregates and stereotypical propagation of Tau pathology through the brain are common hallmarks of tauopathies, including Alzheimer’s disease (AD. Propagation of Tau pathology appears to occur along connected neurons, but whether synaptic contacts between neurons are facilitating propagation has not been demonstrated. Using quantitative in vitro models, we demonstrate that, in parallel to non-synaptic mechanisms, synapses, but not merely the close distance between the cells, enhance the propagation of Tau pathology between acceptor hippocampal neurons and Tau donor cells. Similarly, in an artificial neuronal network using microfluidic devices, synapses and synaptic activity are promoting neuronal Tau pathology propagation in parallel to the non-synaptic mechanisms. Our work indicates that the physical presence of synaptic contacts between neurons facilitate Tau pathology propagation. These findings can have implications for synaptic repair therapies, which may turn out to have adverse effects by promoting propagation of Tau pathology.

  9. Attractor neural networks with resource-efficient synaptic connectivity

    Science.gov (United States)

    Pehlevan, Cengiz; Sengupta, Anirvan

    Memories are thought to be stored in the attractor states of recurrent neural networks. Here we explore how resource constraints interplay with memory storage function to shape synaptic connectivity of attractor networks. We propose that given a set of memories, in the form of population activity patterns, the neural circuit choses a synaptic connectivity configuration that minimizes a resource usage cost. We argue that the total synaptic weight (l1-norm) in the network measures the resource cost because synaptic weight is correlated with synaptic volume, which is a limited resource, and is proportional to neurotransmitter release and post-synaptic current, both of which cost energy. Using numerical simulations and replica theory, we characterize optimal connectivity profiles in resource-efficient attractor networks. Our theory explains several experimental observations on cortical connectivity profiles, 1) connectivity is sparse, because synapses are costly, 2) bidirectional connections are overrepresented and 3) are stronger, because attractor states need strong recurrence.

  10. POST STERILISATION ECTOPIC PREGNANCY IN A TERTIARY CARE CENTRE IN NORTH KERALA

    Directory of Open Access Journals (Sweden)

    Kusumam Vilangot Nhalil

    2017-03-01

    Full Text Available BACKGROUND To study the proportion of ectopic pregnancies with a history of female sterilisation and to assess the risk factors associated with post sterilisation ectopic pregnancy. MATERIALS AND METHODS This is a descriptive cross-sectional study. Cases of ectopic pregnancy that were admitted in Department of Obstetrics and Gynaecology, Kozhikode, from February 2014 to July 2015 are included in the study. Details of patient were collected and they were examined in person. Investigations were recorded and clinical findings were noted. Later outcome of cases was also recorded. Data from the study was coded and entered in MS Excel and analysed with SPSS software. RESULTS There were 372 cases of ectopic pregnancies, of which 51 had history of female sterilisation. Ectopic tubal pregnancies after tubal sterilisation accounted for 13.7% of all the ectopic pregnancies in this study. 45% cases occurred in patients less than 30 years. More than 75% cases of ectopic pregnancy in the study presented at less than 7 weeks. Abdominal pain was the main symptom with which they presented. Out of the 51 cases, more than 80% patients had undergone sterilisation by modified Pomeroy’s technique while 17.6% cases had undergone laparoscopic sterilisation. 98% of the patients had their sterilisation done before 30 years of age. 64.7% cases had undergone sterilisation from a secondary care centre while 35.5% had it from a tertiary care centre. In the present study, more than half of the cases presented (as ectopic pregnancy within 5 years after sterilisation. 15% cases had history of pelvic inflammatory disease. Bilateral near total salpingectomy was done in all cases. CONCLUSION In the present study, it is observed that ectopic pregnancies following female sterilisation are not rare. It constituted 13.7% cases of ectopic pregnancies. There may be a delay in diagnosis as there is a history of sterilisation. Absence of amenorrhoea does not rule out ectopic. Most of

  11. Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

    OpenAIRE

    Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

    2010-01-01

    Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic ...

  12. Statistical mechanics of attractor neural network models with synaptic depression

    International Nuclear Information System (INIS)

    Igarashi, Yasuhiko; Oizumi, Masafumi; Otsubo, Yosuke; Nagata, Kenji; Okada, Masato

    2009-01-01

    Synaptic depression is known to control gain for presynaptic inputs. Since cortical neurons receive thousands of presynaptic inputs, and their outputs are fed into thousands of other neurons, the synaptic depression should influence macroscopic properties of neural networks. We employ simple neural network models to explore the macroscopic effects of synaptic depression. Systems with the synaptic depression cannot be analyzed due to asymmetry of connections with the conventional equilibrium statistical-mechanical approach. Thus, we first propose a microscopic dynamical mean field theory. Next, we derive macroscopic steady state equations and discuss the stabilities of steady states for various types of neural network models.

  13. Experimental Implementation of a Biometric Laser Synaptic Sensor

    Directory of Open Access Journals (Sweden)

    Alexander N. Pisarchik

    2013-12-01

    Full Text Available We fabricate a biometric laser fiber synaptic sensor to transmit information from one neuron cell to the other by an optical way. The optical synapse is constructed on the base of an erbium-doped fiber laser, whose pumped diode current is driven by a pre-synaptic FitzHugh–Nagumo electronic neuron, and the laser output controls a post-synaptic FitzHugh–Nagumo electronic neuron. The implemented laser synapse displays very rich dynamics, including fixed points, periodic orbits with different frequency-locking ratios and chaos. These regimes can be beneficial for efficient biorobotics, where behavioral flexibility subserved by synaptic connectivity is a challenge.

  14. A pivotal role of GSK-3 in synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Clarrisa A Bradley

    2012-02-01

    Full Text Available Glycogen synthase kinase-3 (GSK-3 has many cellular functions. Recent evidence suggests that it plays a key role in certain types of synaptic plasticity, in particular a form of long-term depression (LTD that is induced by the synaptic activation of N-methyl-D-aspartate (NMDA receptors. In the present article we summarise what is currently known concerning the roles of GSK-3 in synaptic plasticity at both glutamatergic and GABAergic synapses. We summarise its role in cognition and speculate on how alterations in the synaptic functioning of GSK-3 may be a major factor in certain neurodegenerative disorders.

  15. proBDNF Negatively Regulates Neuronal Remodeling, Synaptic Transmission, and Synaptic Plasticity in Hippocampus

    Directory of Open Access Journals (Sweden)

    Jianmin Yang

    2014-05-01

    Full Text Available Experience-dependent plasticity shapes postnatal development of neural circuits, but the mechanisms that refine dendritic arbors, remodel spines, and impair synaptic activity are poorly understood. Mature brain-derived neurotrophic factor (BDNF modulates neuronal morphology and synaptic plasticity, including long-term potentiation (LTP via TrkB activation. BDNF is initially translated as proBDNF, which binds p75NTR. In vitro, recombinant proBDNF modulates neuronal structure and alters hippocampal long-term plasticity, but the actions of endogenously expressed proBDNF are unclear. Therefore, we generated a cleavage-resistant probdnf knockin mouse. Our results demonstrate that proBDNF negatively regulates hippocampal dendritic complexity and spine density through p75NTR. Hippocampal slices from probdnf mice exhibit depressed synaptic transmission, impaired LTP, and enhanced long-term depression (LTD in area CA1. These results suggest that proBDNF acts in vivo as a biologically active factor that regulates hippocampal structure, synaptic transmission, and plasticity, effects that are distinct from those of mature BDNF.

  16. 78 FR 29703 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2013-05-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-844] Narrow Woven Ribbons With... AGENCY: Import Administration, International Trade Administration, Department of Commerce. SUMMARY: The..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW...

  17. ATRF Ribbon-Cutting Ceremony Coincides with Chamber of Commerce Centennial Gala | Poster

    Science.gov (United States)

    By Frank Blanchard, Staff Writer U.S. Rep. Roscoe Bartlett, NCI Deputy Director for Management John Czajkowski, and SAIC Corporate Chief Executive Officer (CEO) John Jumper were joined by representatives of the Frederick County Chamber of Commerce in cutting the ribbon for the National Cancer Institute’s Advanced Technology Research Facility (ATRF).

  18. Nanocrystallization in Co67Cr7Fe4Si8B14 Amorphous Alloy Ribbons

    Directory of Open Access Journals (Sweden)

    Zahra Jamili-Shirvan

    2013-12-01

    Full Text Available The nanocrystallization of Co67Fe4Cr7Si8B14 amorphous ribbons which prepared by planar flow melt spinning process (PFMS was investigated. Crystallization of the ribbons was studied by differential thermal analysis (DTA, X-ray diffraction (XRD and transmission electron microscopy (TEM. The DTA result of amorphous ribbon at heating rate of 10˚C/min showedoccurrence of phase transitions in two stages. The ribbons were isothermally annealed for 30 minutes in argon atmosphere at different temperatures between 300 and 650ºC with 25ºC steps. The magnetic properties of annealed samples were measured using a vibrating sample magnetometer (VSM. The VSM results revealed that optimum soft magnetic properties occurred at 400ºC. XRD patterns showed that the samples isothermally annealed up to 450ºC were amorphous, while TEM results at 400ºC indicated 7-8 nm mean size nanocrytallites in amorphous matrix and size of the nanocrystallites increased by increasing temperature. Also by X-ray diffraction pattern, precipitation of different phases at higher temperatures confirmed.

  19. Temperature dependent evolution of wrinkled single-crystal silicon ribbons on shape memory polymers.

    Science.gov (United States)

    Wang, Yu; Yu, Kai; Qi, H Jerry; Xiao, Jianliang

    2017-10-25

    Shape memory polymers (SMPs) can remember two or more distinct shapes, and thus can have a lot of potential applications. This paper presents combined experimental and theoretical studies on the wrinkling of single-crystal Si ribbons on SMPs and the temperature dependent evolution. Using the shape memory effect of heat responsive SMPs, this study provides a method to build wavy forms of single-crystal silicon thin films on top of SMP substrates. Silicon ribbons obtained from a Si-on-insulator (SOI) wafer are released and transferred onto the surface of programmed SMPs. Then such bilayer systems are recovered at different temperatures, yielding well-defined, wavy profiles of Si ribbons. The wavy profiles are shown to evolve with time, and the evolution behavior strongly depends on the recovery temperature. At relatively low recovery temperatures, both wrinkle wavelength and amplitude increase with time as evolution progresses. Finite element analysis (FEA) accounting for the thermomechanical behavior of SMPs is conducted to study the wrinkling of Si ribbons on SMPs, which shows good agreement with experiment. Merging of wrinkles is observed in FEA, which could explain the increase of wrinkle wavelength observed in the experiment. This study can have important implications for smart stretchable electronics, wrinkling mechanics, stimuli-responsive surface engineering, and advanced manufacturing.

  20. Fish Marketing of Ribbon Fish (Trichiurus sp. in Nusantara Fishing Port (NFPat Palabuhanratu, West Java

    Directory of Open Access Journals (Sweden)

    Nur Bambang Azis

    2018-01-01

    Full Text Available The objective of this research is to study the marketing process of ribbon fish (Trichiurus sp., including the marketing margin, marketing agencies, traders and marketing channels The research was carried out for 3 mo in Nusantara Fishing Port (NFP, Palabuhanratu, Sukabumi, West Java. A case study was used in this research. A purposive sampling method was used to collect data from 55 respondents of fish marketing, consisting of fishermen, agents, traders, and retailers, who were involved in the marketing of ribbon fish in NFP Palabuhanratu. The result of the research showed that ribbon fish production in Palabuhanratu fluctuated from year to year. There are two types of ribbon fish marketing, i.e. type one is from fishermen to retailers, and type two is indirect marketing from fisherman to consumers through intermediate traders (exporters. The greatest marketing margin was obtained from the first type, while the smallest marketing margin was obtained from type two. The form of the market was considered to be oligopsony market. Fisherman’s share is greatest in the collectors and the smallest share is on retailers. Marketing process in traders is efficient due to its lowest margin and highest fisherman’s share.

  1. GMI effect in CuO coated Co-based amorphous ribbons

    International Nuclear Information System (INIS)

    Taysioglu, Asli Ayten; Peksoz, Ahmet; Kaya, Yunus; Derebasi, Naim; Irez, Gazi; Kaynak, Gokay

    2009-01-01

    A Copper oxide (CuO) film has been grown on a surface of Co-based amorphous ribbon using chemical successive ionic layer adsorption and reaction technique, at room temperature and atmosphere pressure. The influence of coating and width of ribbon on giant magneto impedance have been investigated over a frequency range from 0.1 to 3 MHz and under a static magnetic field between -8 and +8 kA/m. The results showed that Co-based amorphous ribbons, which are coated CuO film, have a significant effect on the magnitude and operation frequency for the giant magneto impedance effect as compared to the samples without coating. The highest giant magneto impedance effect was found to be 14.90 on 5 mm width coated ribbon, which is 60% higher than the sample without coating. A surface observation of these samples has been carried out by an atomic force microscope. The AFM images reveal the difference between surfaces of coated and as-cast sample.

  2. Growth behaviour of twisted ribbons of barium carbonate/silica self-assembled ceramics

    International Nuclear Information System (INIS)

    Garcia-Ruiz, J.M.; Moreno, A.

    1997-01-01

    Twisted ribbons of self-assembled crystal aggregates of barium carbonate, in the presence of silicate ions at pH 9.5 grow at constant rate between 20 and 50 mu m/min. The morphological behaviour depends on temperature, while it was demonstrated to be independent of the viscosity of the growth environment. (Author) 7 refs

  3. The identification of a sensitizing component used in the manufacturing of an ink ribbon

    Science.gov (United States)

    Anderson, Stacey E.; Tapp, Loren; Durgam, Srinivas; Meade, B. Jean; Jackson, Laurel G.; Cohen, David E.

    2015-01-01

    Skin diseases including dermatitis constitute ≈ 30% of all occupational illnesses, with a high incidence in the printing industry. An outbreak of contact dermatitis among employees at an ink ribbon manufacturing plant was investigated by scientists from the National Institute for Occupational Safety and Health (NIOSH). Employees in the process areas of the plant were exposed to numerous chemicals and many had experienced skin rashes, especially after the introduction of a new ink ribbon product. To identify the causative agent(s) of the occupational dermatitis, the murine local lymph node assay (LLNA) was used to identify the potential of the chemicals used in the manufacture of the ink ribbon to induce allergic contact dermatitis. Follow-up patch testing with the suspected allergens was conducted on exposed employees. Polyvinyl butyral, a chemical component used in the manufacture of the ink ribbon in question and other products, tested positive in the LLNA, with an EC3 of 3.6%, which identifies it as a potential sensitizer; however, no employees tested positive to this chemical during skin patch testing. This finding has implications beyond those described in this report because of occupational exposure to polyvinyl butyral outside of the printing industry. PMID:22375946

  4. Magnetic properties of nanocrystallized Fe-Pt-B melt-spun ribbons

    International Nuclear Information System (INIS)

    Yamamoto, Tokujiro; Omori, Akihiro; Kimura, Hisamichi; Inoue, Akihisa

    2007-01-01

    L1 0 FePt nanoparticles have been prepared by etching grain boundaries of heat-treated melt-spun Fe-19Pt-25B (at.%) alloy ribbons. It is revealed that an L1 0 FePt nanocrystalline phase is directly formed from the Fe-Pt-B amorphous ribbons by long-time heat treatment at low temperatures in the vicinity of 723 K. With increasing heat treatment time, dimensions of the nanocrystallized FePt grains increase, accompanied by a change from soft ferromagnetic to hard ferromagnetic. The ribbon crystallized at 723 K for 1.8 ks consists of only an FePt L1 0 phase and its coercivity is as low as 0.381 kA/m. However, it increases to 372 kA/m with increasing grain size of precipitated L1 0 phase to about 30 nm by heat treatment for 86.4 ks, while the saturation magnetic flux density remains constant at about 0.4 T. Etching boundaries in heat-treated ribbons has been performed to obtain ferromagnetic L1 0 FePt nanoparticles and several particles were observed by means of transmission electron microscopy

  5. GMI effect in CuO coated Co-based amorphous ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Taysioglu, Asli Ayten [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Peksoz, Ahmet, E-mail: peksoz@uludag.edu.t [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaya, Yunus [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Derebasi, Naim [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Irez, Gazi [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaynak, Gokay [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey)

    2009-11-13

    A Copper oxide (CuO) film has been grown on a surface of Co-based amorphous ribbon using chemical successive ionic layer adsorption and reaction technique, at room temperature and atmosphere pressure. The influence of coating and width of ribbon on giant magneto impedance have been investigated over a frequency range from 0.1 to 3 MHz and under a static magnetic field between -8 and +8 kA/m. The results showed that Co-based amorphous ribbons, which are coated CuO film, have a significant effect on the magnitude and operation frequency for the giant magneto impedance effect as compared to the samples without coating. The highest giant magneto impedance effect was found to be 14.90 on 5 mm width coated ribbon, which is 60% higher than the sample without coating. A surface observation of these samples has been carried out by an atomic force microscope. The AFM images reveal the difference between surfaces of coated and as-cast sample.

  6. 75 FR 11908 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-03-12

    ...)] Narrow Woven Ribbons With Woven Selvedge From China and Taiwan AGENCY: United States International Trade...(b) of the Act (19 U.S.C. 1673d(b)) to determine whether an industry in the United States is materially injured or threatened with material injury, or the establishment of an industry in the United...

  7. 75 FR 53711 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-09-01

    ... Woven Ribbons With Woven Selvedge From China and Taiwan Determinations On the basis of the record \\1... U.S.C. 1673d(b)) (the Act), that an industry in the United States is threatened with material injury... (19 U.S.C. 1673d(b)), that an industry in the United States is threatened with material injury by...

  8. Magnetic and surface properties of Fe-Nb (Mo, V)-Cu-B-Si ribbons

    International Nuclear Information System (INIS)

    Butvinova, B.; Butvin, P.; Svec, P. Sr.; Matko, I.; Svec, P.; Janickovic, D.; Kadlecikova, M.

    2014-01-01

    The rapidly quenched Finemet (FeNbCuBSi) ribbons prepared by planar flow casting of the melt are very variable to obtain very good soft-magnetic properties. An appropriate thermal treatment leading to ultra-fine grain structure enables to attain such properties as desired for practical use. Increasing Fe percentage to the detriment of non-magnetic components lifts saturation induction above 1.3 T, preserves low coercivity and makes the alloy even cheaper to suit its mass production for use in power electronics. Apart from the plenty of benefits the ribbons show some risks. One of them is macroscopic heterogeneity, which often manifests via differences between surfaces and interior of a ribbon [3]. The surfaces squeeze (by in-plane force) the interior of many such ribbons and if engaged in magnetoelastic interaction, the force affects the resulting magnetic anisotropy [4]. Current research shows that changes of hysteresis loop shape come rather from surface crystallization and not from oxides namely in positively magnetostrictive alloys FeNbCuBSi known as low- Si Finemets. The object of this work is to verify whether the substitution of another element instead of Nb (usually incorporated as the grain-growth blocker) can change surface properties and affects the resulting magnetic properties. We chose V and Mo instead of Nb. Oxides, oxyhydroxides and a possible squeezing layer was looked for after higher temperature annealing which ensures partially nanocrystalline structure. (authors)

  9. 75 FR 66766 - NIAID Blue Ribbon Panel Meeting on Adjuvant Discovery and Development

    Science.gov (United States)

    2010-10-29

    ..., identifies gaps in knowledge and capabilities, and defines NIAID's goals for the continued discovery...), will convene a Blue Ribbon Panel to provide expertise in developing a strategic plan and research... vaccines. NIAID has developed a draft Strategic Plan and Research Agenda for Adjuvant Discovery and...

  10. A Quantitative Examination of the Educational Technology Characteristics of Ohio Schools and Their Blue Ribbon Status

    Science.gov (United States)

    Goon, Dean A.

    2012-01-01

    The purpose of this study was to analyze data from Ohio schools and the frequency of use of educational technology, a teacher's comfort level using technology, and a teacher's beliefs about the effect of educational technology on teaching and learning based upon the school's Blue Ribbon award status. The study used an ex-post facto, quantitative…

  11. Magnetic properties, phase evolution, and microstructure of the Co–Zr–V ribbons

    International Nuclear Information System (INIS)

    Hou, Zhipeng; Su, Feng; Xu, Shifeng; Zhang, Jinbao; Wu, Chunji; Liu, Dan; Wei, Beipei; Wang, Wenquan

    2013-01-01

    The substitution of V for Zr significantly impeded the growth of grain in the Co 82 Zr 18 ribbons during melt spinning and the amorphous Co 82 Zr 13 V 5 melt-spun ribbons were successfully produced at a wheel speed of 40 m/s. The values of coercivity H c and maximum energy product (BH) max first increased, reaching maximum at 560 °C and then they decreased sharply with increasing the annealing temperature. The optimal magnetic properties of H c =4.0 kOe and (BH) max =5.0 MGOe were obtained in the amorphous ribbons annealed at 560 °C. A suitable grain size of Co 11 Zr 2 phase was considered to be the main reason for the increase in coercivity. - Highlights: • High performance was obtained in Co 82 Zr 13 V 5 amorphous ribbons annealed. • We proved the hard magnetic phase was Co 11 Zr 2 phase. • Suitable grain size of Co 11 Zr 2 phase was the main reason for increase in coercivity

  12. Risk of Ectopic Pregnancy in Women With Inflammatory Bowel Disease

    DEFF Research Database (Denmark)

    de Silva, Punyanganie S; Hansen, Helene H; Wehberg, Sonja

    2018-01-01

    BACKGROUND & AIMS: Few data are available on adverse events of pregnancy in women with inflammatory bowel diseases (IBDs), such as ectopic pregnancy. We assessed the risk of an ectopic pregnancy in pregnancies of women in Denmark with IBD compared with those without IBD over a 22-year period. We...... also examined the disease-specific risks of ectopic pregnancies in pregnancies of women with ulcerative colitis (UC) or Crohn's disease (CD) who underwent IBD-related surgical procedures. METHODS: We performed a retrospective study of all women of child-bearing age (ages, 15-50 y) registered...

  13. Ectopic ureter associated with uterine didelphys and obstructed hemivagina: preoperative diagnosis by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhen J.; Daldrup-Link, Heike; Coakley, Fergus V.; Yeh, Benjamin M. [University of California, San Francisco (United States). Department of Radiology

    2010-03-15

    Uterine didelphys with obstructed hemivagina and ipsilateral renal anomalies is a rare congenital malformation of the female urogenital tract. While the urinary anomalies almost always involve renal agenesis, we report a rare case of a 17-year-old girl with the malformation associated with ectopic ureteral insertion into the obstructed hemivagina, which was diagnosed preoperatively by MR imaging. To the best of our knowledge, preoperative MR imaging diagnosis of the ectopic ureter associated with this syndrome has not been previously reported. Accurate preoperative diagnosis of ectopic ureteral insertion associated with this syndrome is important for surgical planning. (orig.)

  14. Fibroadenoma in an ectopic vulvar breast gland: a common neoplasm in an uncommon site.

    Science.gov (United States)

    Ayadi-Kaddour, A; Khadhar, A; Mlika, M; Braham, E; Ismail, O; Zegal, D; El Mezni, F

    2014-03-01

    Ectopic breast tissue is defined as glands located outside of the breast. It can be found anywhere along the milk line extending from the axilla to the groin, and can occur in the vulva. Ectopic breast tissue should be excised because it may develop benign or malignant pathologic processes. Less than 40 cases of fibroadenoma in the vulva have been reported in the literature. We report a case of a 37-year-old woman presenting a solitary vulvar mass. The mass was excised completely, and histology demonstrated an ectopic breast fibroadenoma. This is one of the few reports on the benign pathologies of vulvar mammary glands.

  15. Ectopic intestinal glands after segmental small bowel irradiation in the cat

    International Nuclear Information System (INIS)

    Rubio, C.A.; Eriksson, B.; Johnsson, L.

    1983-01-01

    Following segmental irradiation of the small bowel, 5 of 64 cats demonstrated ectopic intestinal glands in the submucosal tissue. In addition, one of these 5 cats had foci of abnormal glands in the muscularis mucosae. In 2 of the 5 animals, cellular polymorphism, nucleolar irregularity and loss of cellular polarity were present in irradiation-induced ectopic intestinal glands. The review of the literature indicates that intestinal irradiation may induce intestinal adenocarcinomas with metastatic growth. The possibility that ectopic intestinal glands are precancerous lesions in the irradiated cat is discussed. (Auth.)

  16. Ectopic ureter associated with uterine didelphys and obstructed hemivagina: preoperative diagnosis by MRI

    International Nuclear Information System (INIS)

    Wang, Zhen J.; Daldrup-Link, Heike; Coakley, Fergus V.; Yeh, Benjamin M.

    2010-01-01

    Uterine didelphys with obstructed hemivagina and ipsilateral renal anomalies is a rare congenital malformation of the female urogenital tract. While the urinary anomalies almost always involve renal agenesis, we report a rare case of a 17-year-old girl with the malformation associated with ectopic ureteral insertion into the obstructed hemivagina, which was diagnosed preoperatively by MR imaging. To the best of our knowledge, preoperative MR imaging diagnosis of the ectopic ureter associated with this syndrome has not been previously reported. Accurate preoperative diagnosis of ectopic ureteral insertion associated with this syndrome is important for surgical planning. (orig.)

  17. Point-of-care Ultrasound for the Diagnosis of Ectopic Pregnancy

    Directory of Open Access Journals (Sweden)

    Ahmed Farhat

    2017-09-01

    Full Text Available History of present illness: A 31-year-old female presented to the Emergency Department by ambulance with severe abdominal pain and presyncope. On exam, the patient was hypotensive with suprapubic tenderness. Though the patient denied being pregnant, her labs showed a beta human chorionic gonadotropin (hCG of 38,000 mIU/ml. A bedside transabdominal pelvic ultrasound revealed an ectopic pregnancy and the patient was taken to the operating room for an emergent right salpingectomy. Significant findings: The transabdominal pelvic ultrasound shows an empty uterus (annotated with free fluid and a right sided extrauterine gestational sac representing an ectopic pregnancy (red arrow. Discussion: Ectopic pregnancy is the leading cause of mortality in the first trimester of pregnancy making prompt diagnosis critical.1 Risk factors including history of previous ectopic pregnancy,2 pelvic inflammatory disease,2 increased age,3 and smoking4 can raise suspicion of an ectopic pregnancy. However, the absence of risk factors does not exclude ectopic pregnancy from the differential. Any sexually active female with abdominal pain following a period of amenorrhea should be suspected of an ectopic until proven otherwise. One third of all pregnant women experience abdominal pain and/or vaginal bleeding and 9% of women with an ectopic are asymptomatic. Thus, history alone is insufficient to make the diagnosis.5 In early pregnancy, ectopic pregnancies share the same symptoms as normal pregnancies, including a missed menstrual period, fatigue, and nausea. The first classical signs of an ectopic pregnancy are vaginal bleeding, dizziness, and lower abdominal and/or pelvic pain usually 6 to 8 weeks after a missed menstrual period.5 A meta-analysis of studies on pelvic ultrasonography demonstrated a sensitivity of 99.3% and a negative predictive value of 99.6% for diagnosing ectopic pregnancy and therefore should be utilized as a first-line diagnostic tool for emergency

  18. Case Report of Ectopic Liver on Gallbladder Serosa with a Brief Review of the Literature

    Directory of Open Access Journals (Sweden)

    Vishnu R. Mani

    2016-01-01

    Full Text Available This case describes an intraoperative incidental finding and surgical removal of ectopic liver tissue attached to the gallbladder during a standard laparoscopic cholecystectomy for acute cholecystitis. These anomalies are rare, with interesting associations and possible clinically relevant complications. The details of the case, along with a brief literature review of embryology, common ectopic sites, and associations/complications, are presented in this paper. Since laparoscopic cholecystectomy is a very common procedure, it is important to increase vigilance of ectopic liver tissues during surgeries to minimize complications and provide optimal management.

  19. Synaptic Democracy and Vesicular Transport in Axons

    Science.gov (United States)

    Bressloff, Paul C.; Levien, Ethan

    2015-04-01

    Synaptic democracy concerns the general problem of how regions of an axon or dendrite far from the cell body (soma) of a neuron can play an effective role in neuronal function. For example, stimulated synapses far from the soma are unlikely to influence the firing of a neuron unless some sort of active dendritic processing occurs. Analogously, the motor-driven transport of newly synthesized proteins from the soma to presynaptic targets along the axon tends to favor the delivery of resources to proximal synapses. Both of these phenomena reflect fundamental limitations of transport processes based on a localized source. In this Letter, we show that a more democratic distribution of proteins along an axon can be achieved by making the transport process less efficient. This involves two components: bidirectional or "stop-and-go" motor transport (which can be modeled in terms of advection-diffusion), and reversible interactions between motor-cargo complexes and synaptic targets. Both of these features have recently been observed experimentally. Our model suggests that, just as in human societies, there needs to be a balance between "efficiency" and "equality".

  20. Use of intraventricular ribbon gauze to reduce particulate emboli during aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Loubani Mahmoud

    2006-11-01

    Full Text Available Abstract Background The incidence of cerebrovascular accidents following aortic valve surgery remains a devastating complication. The aim of this study was to determine the number of potential embolic material arising during aortic valve replacement and to examine the efficacy of using ribbon gauze in the left ventricle during removal of the native valve and decalcification of the aortic annulus. Methods Ribbon gauze was inserted into the left ventricular cavity prior to aortic valve excision in an unselected, prospectively studied series of 30 patients undergoing aortic valve replacement. A further 30 lengths of ribbon gauze were soaked in the pericardiotomy blood of the same patients and all were subjected to histological analysis. Results The median number of tissue fragments from the aortic valve replacement group was significantly higher than in the control group 5 (0–18 versus 0 (0–1 (p = 3.6 × 10-5. The size of tissue fragments varied between 0.1 and 9.0 mm with a mean of 0.61 ± 1.12 mm and a median of 0.2 mm. There was a significantly higher number of tissue fragments associated with patients having surgery for aortic stenosis when compared with patients who had aortic regurgitation with median of 5 (0–18 versus 0 (0–3 (p = 0.8 × 10-3. Conclusion Significant capture of particulate debris by the intraventricular ribbon gauze suggests that the technique of left ventricular ribbon gauze insertion during aortic valve excision has merit.

  1. A CIRCULAR-RIBBON SOLAR FLARE FOLLOWING AN ASYMMETRIC FILAMENT ERUPTION

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang; Deng, Na; Lee, Jeongwoo; Wang, Haimin [Space Weather Research Laboratory, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States); Liu, Rui [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026 (China); Pariat, Étienne [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, F-92190 Meudon (France); Wiegelmann, Thomas [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig Weg 3, D-37077 Göttingen (Germany); Liu, Yang [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States); Kleint, Lucia, E-mail: chang.liu@njit.edu [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland)

    2015-10-20

    The dynamic properties of flare ribbons and the often associated filament eruptions can provide crucial information on the flaring coronal magnetic field. This Letter analyzes the GOES-class X1.0 flare on 2014 March 29 (SOL2014-03-29T17:48), in which we found an asymmetric eruption of a sigmoidal filament and an ensuing circular flare ribbon. Initially both EUV images and a preflare nonlinear force-free field model show that the filament is embedded in magnetic fields with a fan-spine-like structure. In the first phase, which is defined by a weak but still increasing X-ray emission, the western portion of the sigmoidal filament arches upward and then remains quasi-static for about five minutes. The western fan-like and the outer spine-like fields display an ascending motion, and several associated ribbons begin to brighten. Also found is a bright EUV flow that streams down along the eastern fan-like field. In the second phase that includes the main peak of hard X-ray (HXR) emission, the filament erupts, leaving behind two major HXR sources formed around its central dip portion and a circular ribbon brightened sequentially. The expanding western fan-like field interacts intensively with the outer spine-like field, as clearly seen in running difference EUV images. We discuss these observations in favor of a scenario where the asymmetric eruption of the sigmoidal filament is initiated due to an MHD instability and further facilitated by reconnection at a quasi-null in corona; the latter is in turn enhanced by the filament eruption and subsequently produces the circular flare ribbon.

  2. A presynaptic role for PKA in synaptic tagging and memory.

    Science.gov (United States)

    Park, Alan Jung; Havekes, Robbert; Choi, Jennifer Hk; Luczak, Vince; Nie, Ting; Huang, Ted; Abel, Ted

    2014-10-01

    Protein kinase A (PKA) and other signaling molecules are spatially restricted within neurons by A-kinase anchoring proteins (AKAPs). Although studies on compartmentalized PKA signaling have focused on postsynaptic mechanisms, presynaptically anchored PKA may contribute to synaptic plasticity and memory because PKA also regulates presynaptic transmitter release. Here, we examine this issue using genetic and pharmacological application of Ht31, a PKA anchoring disrupting peptide. At the hippocampal Schaffer collateral CA3-CA1 synapse, Ht31 treatment elicits a rapid decay of synaptic responses to repetitive stimuli, indicating a fast depletion of the readily releasable pool of synaptic vesicles. The interaction between PKA and proteins involved in producing this pool of synaptic vesicles is supported by biochemical assays showing that synaptic vesicle protein 2 (SV2), Rim1, and SNAP25 are components of a complex that interacts with cAMP. Moreover, acute treatment with Ht31 reduces the levels of SV2. Finally, experiments with transgenic mouse lines, which express Ht31 in excitatory neurons at the Schaffer collateral CA3-CA1 synapse, highlight a requirement for presynaptically anchored PKA in pathway-specific synaptic tagging and long-term contextual fear memory. These results suggest that a presynaptically compartmentalized PKA is critical for synaptic plasticity and memory by regulating the readily releasable pool of synaptic vesicles. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Glutamatergic synaptic plasticity in the mesocorticolimbic system in addiction

    Directory of Open Access Journals (Sweden)

    Aile evan Huijstee

    2015-01-01

    Full Text Available Addictive drugs remodel the brain’s reward circuitry, the mesocorticolimbic dopamine system, by inducing widespread adaptations of glutamatergic synapses. This drug-induced synaptic plasticity is thought to contribute to both the development and the persistence of addiction. This review highlights the synaptic modifications that are induced by in vivo exposure to addictive drugs and describes how these drug-induced synaptic changes may contribute to the different components of addictive behaviour, such as compulsive drug use despite negative consequences and relapse. Initially, exposure to an addictive drug induces synaptic changes in the ventral tegmental area (VTA. This drug-induced synaptic potentiation in the VTA subsequently triggers synaptic changes in downstream areas of the mesocorticolimbic system, such as the nucleus accumbens (NAc and the prefrontal cortex (PFC, with further drug exposure. These glutamatergic synaptic alterations are then thought to mediate many of the behavioural symptoms that characterize addiction. The later stages of glutamatergic synaptic plasticity in the NAc and in particular in the PFC play a role in maintaining addiction and drive relapse to drug-taking induced by drug-associated cues. Remodelling of PFC glutamatergic circuits can persist into adulthood, causing a lasting vulnerability to relapse. We will discuss how these neurobiological changes produced by drugs of abuse may provide novel targets for potential treatment strategies for addiction.

  4. Phosphodiesterase Inhibition to Target the Synaptic Dysfunction in Alzheimer's Disease

    Science.gov (United States)

    Bales, Kelly R.; Plath, Niels; Svenstrup, Niels; Menniti, Frank S.

    Alzheimer's Disease (AD) is a disease of synaptic dysfunction that ultimately proceeds to neuronal death. There is a wealth of evidence that indicates the final common mediator of this neurotoxic process is the formation and actions on synaptotoxic b-amyloid (Aβ). The premise in this review is that synaptic dysfunction may also be an initiating factor in for AD and promote synaptotoxic Aβ formation. This latter hypothesis is consistent with the fact that the most common risk factors for AD, apolipoprotein E (ApoE) allele status, age, education, and fitness, encompass suboptimal synaptic function. Thus, the synaptic dysfunction in AD may be both cause and effect, and remediating synaptic dysfunction in AD may have acute effects on the symptoms present at the initiation of therapy and also slow disease progression. The cyclic nucleotide (cAMP and cGMP) signaling systems are intimately involved in the regulation of synaptic homeostasis. The phosphodiesterases (PDEs) are a superfamily of enzymes that critically regulate spatial and temporal aspects of cyclic nucleotide signaling through metabolic inactivation of cAMP and cGMP. Thus, targeting the PDEs to promote improved synaptic function, or 'synaptic resilience', may be an effective and facile approach to new symptomatic and disease modifying therapies for AD. There continues to be a significant drug discovery effort aimed at discovering PDE inhibitors to treat a variety of neuropsychiatric disorders. Here we review the current status of those efforts as they relate to potential new therapies for AD.

  5. Synaptogenic proteins and synaptic organizers: "many hands make light work".

    Science.gov (United States)

    Brose, Nils

    2009-03-12

    Synaptogenesis is thought to be mediated by cell adhesion proteins, which induce the initial contact between an axon and its target cell and subsequently recruit and organize the presynaptic and postsynaptic protein machinery required for synaptic transmission. A new study by Linhoff and colleagues in this issue of Neuron identifies adhesion proteins of the LRRTM family as novel synaptic organizers.

  6. Synaptic Tagging, Evaluation of Memories, and the Distal Reward Problem

    Science.gov (United States)

    Papper, Marc; Kempter, Richard; Leibold, Christian

    2011-01-01

    Long-term synaptic plasticity exhibits distinct phases. The synaptic tagging hypothesis suggests an early phase in which synapses are prepared, or "tagged," for protein capture, and a late phase in which those proteins are integrated into the synapses to achieve memory consolidation. The synapse specificity of the tags is consistent with…

  7. Glutamatergic synaptic plasticity in the mesocorticolimbic system in addiction

    Science.gov (United States)

    van Huijstee, Aile N.; Mansvelder, Huibert D.

    2015-01-01

    Addictive drugs remodel the brain’s reward circuitry, the mesocorticolimbic dopamine (DA) system, by inducing widespread adaptations of glutamatergic synapses. This drug-induced synaptic plasticity is thought to contribute to both the development and the persistence of addiction. This review highlights the synaptic modifications that are induced by in vivo exposure to addictive drugs and describes how these drug-induced synaptic changes may contribute to the different components of addictive behavior, such as compulsive drug use despite negative consequences and relapse. Initially, exposure to an addictive drug induces synaptic changes in the ventral tegmental area (VTA). This drug-induced synaptic potentiation in the VTA subsequently triggers synaptic changes in downstream areas of the mesocorticolimbic system, such as the nucleus accumbens (NAc) and the prefrontal cortex (PFC), with further drug exposure. These glutamatergic synaptic alterations are then thought to mediate many of the behavioral symptoms that characterize addiction. The later stages of glutamatergic synaptic plasticity in the NAc and in particular in the PFC play a role in maintaining addiction and drive relapse to drug-taking induced by drug-associated cues. Remodeling of PFC glutamatergic circuits can persist into adulthood, causing a lasting vulnerability to relapse. We will discuss how these neurobiological changes produced by drugs of abuse may provide novel targets for potential treatment strategies for addiction. PMID:25653591

  8. Modulation of synaptic plasticity by stress hormone associates with plastic alteration of synaptic NMDA receptor in the adult hippocampus.

    Directory of Open Access Journals (Sweden)

    Yiu Chung Tse

    Full Text Available Stress exerts a profound impact on learning and memory, in part, through the actions of adrenal corticosterone (CORT on synaptic plasticity, a cellular model of learning and memory. Increasing findings suggest that CORT exerts its impact on synaptic plasticity by altering the functional properties of glutamate receptors, which include changes in the motility and function of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid subtype of glutamate receptor (AMPAR that are responsible for the expression of synaptic plasticity. Here we provide evidence that CORT could also regulate synaptic plasticity by modulating the function of synaptic N-methyl-D-aspartate receptors (NMDARs, which mediate the induction of synaptic plasticity. We found that stress level CORT applied to adult rat hippocampal slices potentiated evoked NMDAR-mediated synaptic responses within 30 min. Surprisingly, following this fast-onset change, we observed a slow-onset (>1 hour after termination of CORT exposure increase in synaptic expression of GluN2A-containing NMDARs. To investigate the consequences of the distinct fast- and slow-onset modulation of NMDARs for synaptic plasticity, we examined the formation of long-term potentiation (LTP and long-term depression (LTD within relevant time windows. Paralleling the increased NMDAR function, both LTP and LTD were facilitated during CORT treatment. However, 1-2 hours after CORT treatment when synaptic expression of GluN2A-containing NMDARs is increased, bidirectional plasticity was no longer facilitated. Our findings reveal the remarkable plasticity of NMDARs in the adult hippocampus in response to CORT. CORT-mediated slow-onset increase in GluN2A in hippocampal synapses could be a homeostatic mechanism to normalize synaptic plasticity following fast-onset stress-induced facilitation.

  9. Effects of pre-deformation on the martensitic transformation and magnetocaloric property in Ni-Mn-Co-Sn ribbons

    International Nuclear Information System (INIS)

    Ma Sheng-Can; Xuan Hai-Cheng; Zhang Cheng-Liang; Wang Liao-Yu; Cao Qing-Qi; Wang Dun-Hui; Du You-Wei

    2010-01-01

    This paper investigates the martensitic transformation and magnetocaloric effect in pre-deformed Ni-Mn-Co-Sn ribbons. The experimental results show that the reverse martensitic transformation temperature T M increases with the increasing pre-pressure, suggesting that pre-deformation is another effective way to adjust T M in ferromagnetic shape memory alloys. Large magnetic entropy changes and refrigerant capacities are obtained in these ribbons as well. It also discusses the origin of the enhanced martensitic transformation temperature and magnetocaloric property in pre-deformed Ni-Mn-Co-Sn ribbons

  10. MPTP-meditated hippocampal dopamine deprivation modulates synaptic transmission and activity-dependent synaptic plasticity

    International Nuclear Information System (INIS)

    Zhu Guoqi; Chen Ying; Huang Yuying; Li Qinglin; Behnisch, Thomas

    2011-01-01

    Parkinson's disease (PD)-like symptoms including learning deficits are inducible by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Therefore, it is possible that MPTP may disturb hippocampal memory processing by modulation of dopamine (DA)- and activity-dependent synaptic plasticity. We demonstrate here that intraperitoneal (i.p.) MPTP injection reduces the number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN) within 7 days. Subsequently, the TH expression level in SN and hippocampus and the amount of DA and its metabolite DOPAC in striatum and hippocampus decrease. DA depletion does not alter basal synaptic transmission and changes pair-pulse facilitation (PPF) of field excitatory postsynaptic potentials (fEPSPs) only at the 30 ms inter-pulse interval. In addition, the induction of long-term potentiation (LTP) is impaired whereas the duration of long-term depression (LTD) becomes prolonged. Since both LTP and LTD depend critically on activation of NMDA and DA receptors, we also tested the effect of DA depletion on NMDA receptor-mediated synaptic transmission. Seven days after MPTP injection, the NMDA receptor-mediated fEPSPs are decreased by about 23%. Blocking the NMDA receptor-mediated fEPSP does not mimic the MPTP-LTP. Only co-application of D1/D5 and NMDA receptor antagonists during tetanization resembled the time course of fEPSP potentiation as observed 7 days after i.p. MPTP injection. Together, our data demonstrate that MPTP-induced degeneration of DA neurons and the subsequent hippocampal DA depletion alter NMDA receptor-mediated synaptic transmission and activity-dependent synaptic plasticity. - Highlights: → I.p. MPTP-injection mediates death of dopaminergic neurons. → I.p. MPTP-injection depletes DA and DOPAC in striatum and hippocampus. → I.p. MPTP-injection does not alter basal synaptic transmission. → Reduction of LTP and enhancement of LTD after i.p. MPTP-injection. → Attenuation of NMDA-receptors mediated

  11. National clinical guidelines for management of the palatally ectopic maxillary canine.

    Science.gov (United States)

    Husain, J; Burden, D; McSherry, P; Morris, D; Allen, M

    2012-08-01

    This review summarises updated clinical guidelines produced by the Clinical Standards Committee of the Faculty of Dental Surgery, Royal College of Surgeons of England (FDSRCS). This guideline on the management of the palatally ectopic maxillary canine illustrates the information contained in the recently updated online version. The timely recognition of ectopic canines is important for the overall management of the dentition. This review illustrates five management strategies for ectopic permanent canines: interceptive treatment by extraction of the deciduous canine, surgical exposure and orthodontic alignment, surgical removal of the palatally ectopic permanent canine, auto-transplantation and no active treatment/leave and observe. The current available evidence for each of these management options has been evaluated and awarded a grade used by the Scottish Intercollegiate Guidelines Network.

  12. B lymphocyte autoimmunity in rheumatoid synovitis is independent of ectopic lymphoid neogenesis

    NARCIS (Netherlands)

    Cantaert, Tineke; Kolln, Johanna; Timmer, Trieneke; van der Pouw Kraan, Tineke C.; Vandooren, Bernard; Thurlings, Rogier M.; Cañete, Juan D.; Catrina, Anca I.; Out, Theo; Verweij, Cor L.; Zhang, Yiping; Tak, Paul P.; Baeten, Dominique

    2008-01-01

    B lymphocyte autoimmunity plays a crucial role in the pathogenesis of rheumatoid arthritis. The local production of autoantibodies and the presence of ectopic lymphoid neogenesis in the rheumatoid synovium suggest that these dedicated microenvironments resembling canonical lymphoid follicles may

  13. Ectopic Intrathoracic Hepatic Tissue and Accessory Lung Lobe Aplasia in a Dog.

    Science.gov (United States)

    Lande, Rachel; Dvorak, Laura; Gardiner, David W; Bahr, Anne

    2015-01-01

    A 6 yr old male Yorkshire terrier was presented for an ~6 yr history of progressive cough and dyspnea. Thoracic radiographs revealed a 6 cm diameter mass within the right caudal thorax. Thoracic ultrasound identified an intrathoracic mass ultrasonographically consistent with liver tissue and a chronic diaphragmatic hernia was suspected. Exploratory laparotomy was performed, but no evidence of a diaphragmatic hernia was identified. Thoracic exploration identified abnormal lung parenchyma. The accessory lung lobe was removed using a stapling devise near its base. The consolidated mass had the gross appearance of liver and was histologically identified as ectopic hepatic tissue. Ectopic hepatic tissue, unlike ectopic splenic and pancreatic tissue, is rare and generally has a subdiaphragmatic distribution. This solitary case report demonstrates that ectopic intrathoracic hepatic tissue should be considered a differential diagnosis for a caudal mediastinal mass.

  14. Gastric Metastasis of Ectopic Breast Cancer Mimicking Axillary Metastasis of Primary Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Selami Ilgaz Kayılıoğlu

    2014-01-01

    Full Text Available Ectopic breast tissue has the ability to undergo all the pathological changes of the normal breast, including breast cancer. Gastrointestinal metastasis of breast cancer is rarely observed and it is very difficult to differentiate gastric metastases from primary gastric cancer. We present a case of 52-year-old female, who suffered from abdominal pain. Physical examination showed a palpable mass in the left anterior axilla and computerized tomography revealed gastric wall thickening with linitis plastica. When gastroscopic biopsy showed no signs of malignancy, excisional biopsy was performed in the left axilla. Histological examination revealed invasive lobular carcinoma of the breast, consistent with ectopic breast cancer. Further gastroscopic submucosal biopsies and immunohistochemical studies revealed gastric metastases of invasive lobular carcinoma. Axillary ectopic breast tissue carcinomas can mimic axillary lymphadenopathies. Additionally, gastric metastasis of breast cancer is an uncommon but possible condition. To the best of our knowledge, this is the first report of ectopic breast cancer with gastric metastasis.

  15. incidence of ectopic pregnancy in calabar, nigeria: two halves of the ...

    African Journals Online (AJOL)

    user

    Reports of a rising incidence of ectopic pregnancy (EP) in the country and beyond prompted ... O. Udofia, Dept. of Psychiatry, University of Calabar Teaching Hospital, Calabar, Nigeria .... on reproductive performance among EP patients.

  16. Laparoscopic assisted percutaneous nephrolithotomy in chronic kidney disease patients with ectopic pelvic kidney

    Directory of Open Access Journals (Sweden)

    Sujata K Patwardhan

    2017-01-01

    Conclusion: Although laparoscopic assisted PCNL is an option in the management of patients with stone disease in ectopic pelvic kidney, prolonged time for healing of tract may increase postoperative morbidity in these patients with impaired renal function.

  17. Nicotinic mechanisms influencing synaptic plasticity in the hippocampus

    Institute of Scientific and Technical Information of China (English)

    Andon Nicholas PLACZEK; Tao A ZHANG; John Anthony DANI

    2009-01-01

    Nicotinic acetylcholine receptors (nAChRs) are expressed throughout the hippocampus, and nicotinic signaling plays an important role in neuronal function. In the context of learning and memory related behaviors associated with hippocampal function, a potentially significant feature of nAChR activity is the impact it has on synaptic plasticity. Synaptic plasticity in hippocampal neurons has long been considered a contributing cellular mechanism of learning and memory. These same kinds of cellular mechanisms are a factor in the development of nicotine addiction. Nicotinic signaling has been demonstrated by in vitro studies to affect synaptic plasticity in hippocampal neurons via multiple steps, and the signaling has also been shown to evoke synaptic plasticity in vivo. This review focuses on the nAChRs subtypes that contribute to hippocampal synaptic plasticity at the cellular and circuit level. It also considers nicotinic influences over long-term changes in the hippocampus that may contribute to addiction.

  18. Synaptic transmission block by presynaptic injection of oligomeric amyloid beta

    Science.gov (United States)

    Moreno, Herman; Yu, Eunah; Pigino, Gustavo; Hernandez, Alejandro I.; Kim, Natalia; Moreira, Jorge E.; Sugimori, Mutsuyuki; Llinás, Rodolfo R.

    2009-01-01

    Early Alzheimer's disease (AD) pathophysiology is characterized by synaptic changes induced by degradation products of amyloid precursor protein (APP). The exact mechanisms of such modulation are unknown. Here, we report that nanomolar concentrations of intraaxonal oligomeric (o)Aβ42, but not oAβ40 or extracellular oAβ42, acutely inhibited synaptic transmission at the squid giant synapse. Further characterization of this phenotype demonstrated that presynaptic calcium currents were unaffected. However, electron microscopy experiments revealed diminished docked synaptic vesicles in oAβ42-microinjected terminals, without affecting clathrin-coated vesicles. The molecular events of this modulation involved casein kinase 2 and the synaptic vesicle rapid endocytosis pathway. These findings open the possibility of a new therapeutic target aimed at ameliorating synaptic dysfunction in AD. PMID:19304802

  19. [Involvement of aquaporin-4 in synaptic plasticity, learning and memory].

    Science.gov (United States)

    Wu, Xin; Gao, Jian-Feng

    2017-06-25

    Aquaporin-4 (AQP-4) is the predominant water channel in the central nervous system (CNS) and primarily expressed in astrocytes. Astrocytes have been generally believed to play important roles in regulating synaptic plasticity and information processing. However, the role of AQP-4 in regulating synaptic plasticity, learning and memory, cognitive function is only beginning to be investigated. It is well known that synaptic plasticity is the prime candidate for mediating of learning and memory. Long term potentiation (LTP) and long term depression (LTD) are two forms of synaptic plasticity, and they share some but not all the properties and mechanisms. Hippocampus is a part of limbic system that is particularly important in regulation of learning and memory. This article is to review some research progresses of the function of AQP-4 in synaptic plasticity, learning and memory, and propose the possible role of AQP-4 as a new target in the treatment of cognitive dysfunction.

  20. Fermentation performance optimization in an ectopic fermentation system.

    Science.gov (United States)

    Yang, Xiaotong; Geng, Bing; Zhu, Changxiong; Li, Hongna; He, Buwei; Guo, Hui

    2018-07-01

    Ectopic fermentation systems (EFSs) were developed for wastewater treatment. Previous studies have investigated the ability of thermophilic bacteria to improve fermentation performance in EFS. Continuing this research, we evaluated EFS performance using principle component analysis and investigated the addition of different proportions of cow dung. Viable bacteria communities were clustered and identified using BOX-AIR-based repetitive extragenic palindromic-PCR and 16S rDNA analysis. The results revealed optimal conditions for the padding were maize straw inoculated with thermophilic bacteria. Adding 20% cow dung yielded the best pH values (6.94-8.56), higher temperatures, increased wastewater absorption, improved litter quality, and greater microbial quantities. The viable bacteria groups were enriched by the addition of thermophilic consortium, and exogenous strains G21, G14, G4-1, and CR-15 were detected in fermentation process. The proportion of Bacillus species in treatment groups reached 70.37% after fermentation, demonstrating that thermophilic bacteria, especially Bacillus, have an important role in EFS, supporting previous predictions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Ectopic Opening of the Common Bile Duct into the Duodenal Bulb: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seong Su; Park, Soo Youn [Catholic University St. Vincent' s Hospital, Suwon (Korea, Republic of)

    2009-08-15

    An ectopic opening of the common bile duct into the duodenal bulb is a very rare congenital malformation of the bile duct, which may cause a recurrent duodenal ulcer or biliary diseases including choledocholithiasis or cholangitis. ERCP plays major role in the diagnosis of this biliary malformation. We report a case of an ectopic opening of the common bile duct into the duodenal bulb, which was detected on the upper gastrointestinal series.

  2. Ectopic adrenocorticotropic hormone syndrome presenting as hypokalemic metabolic alkalosis and hypertension

    Directory of Open Access Journals (Sweden)

    Mansoor C Abdulla

    2016-01-01

    Full Text Available The ectopic adrenocorticotropic hormone (ACTH syndrome is an uncommon cause of hypercortisolism, which should be considered in patients with hypokalemic metabolic alkalosis and hypertension in the context of lung neoplasm. We report a 60-year-old male patient with severe hypertension, metabolic alkalosis, and hypokalemia as the initial manifestations of an ACTH-secreting small cell lung carcinoma. Ectopic Cushing's syndrome should always be ruled out in patients with severe hypertension and hypokalemia.

  3. Stochastic lattice model of synaptic membrane protein domains.

    Science.gov (United States)

    Li, Yiwei; Kahraman, Osman; Haselwandter, Christoph A

    2017-05-01

    Neurotransmitter receptor molecules, concentrated in synaptic membrane domains along with scaffolds and other kinds of proteins, are crucial for signal transmission across chemical synapses. In common with other membrane protein domains, synaptic domains are characterized by low protein copy numbers and protein crowding, with rapid stochastic turnover of individual molecules. We study here in detail a stochastic lattice model of the receptor-scaffold reaction-diffusion dynamics at synaptic domains that was found previously to capture, at the mean-field level, the self-assembly, stability, and characteristic size of synaptic domains observed in experiments. We show that our stochastic lattice model yields quantitative agreement with mean-field models of nonlinear diffusion in crowded membranes. Through a combination of analytic and numerical solutions of the master equation governing the reaction dynamics at synaptic domains, together with kinetic Monte Carlo simulations, we find substantial discrepancies between mean-field and stochastic models for the reaction dynamics at synaptic domains. Based on the reaction and diffusion properties of synaptic receptors and scaffolds suggested by previous experiments and mean-field calculations, we show that the stochastic reaction-diffusion dynamics of synaptic receptors and scaffolds provide a simple physical mechanism for collective fluctuations in synaptic domains, the molecular turnover observed at synaptic domains, key features of the observed single-molecule trajectories, and spatial heterogeneity in the effective rates at which receptors and scaffolds are recycled at the cell membrane. Our work sheds light on the physical mechanisms and principles linking the collective properties of membrane protein domains to the stochastic dynamics that rule their molecular components.

  4. Alteration of synaptic connectivity of oligodendrocyte precursor cells following demyelination

    Science.gov (United States)

    Sahel, Aurélia; Ortiz, Fernando C.; Kerninon, Christophe; Maldonado, Paloma P.; Angulo, María Cecilia; Nait-Oumesmar, Brahim

    2015-01-01

    Oligodendrocyte precursor cells (OPCs) are a major source of remyelinating oligodendrocytes in demyelinating diseases such as Multiple Sclerosis (MS). While OPCs are innervated by unmyelinated axons in the normal brain, the fate of such synaptic contacts after demyelination is still unclear. By combining electrophysiology and immunostainings in different transgenic mice expressing fluorescent reporters, we studied the synaptic innervation of OPCs in the model of lysolecithin (LPC)-induced demyelination of corpus callosum. Synaptic innervation of reactivated OPCs in the lesion was revealed by the presence of AMPA receptor-mediated synaptic currents, VGluT1+ axon-OPC contacts in 3D confocal reconstructions and synaptic junctions observed by electron microscopy. Moreover, 3D confocal reconstructions of VGluT1 and NG2 immunolabeling showed the existence of glutamatergic axon-OPC contacts in post-mortem MS lesions. Interestingly, patch-clamp recordings in LPC-induced lesions demonstrated a drastic decrease in spontaneous synaptic activity of OPCs early after demyelination that was not caused by an impaired conduction of compound action potentials. A reduction in synaptic connectivity was confirmed by the lack of VGluT1+ axon-OPC contacts in virtually all rapidly proliferating OPCs stained with EdU (50-ethynyl-20-deoxyuridine). At the end of the massive proliferation phase in lesions, the proportion of innervated OPCs rapidly recovers, although the frequency of spontaneous synaptic currents did not reach control levels. In conclusion, our results demonstrate that newly-generated OPCs do not receive synaptic inputs during their active proliferation after demyelination, but gain synapses during the remyelination process. Hence, glutamatergic synaptic inputs may contribute to inhibit OPC proliferation and might have a physiopathological relevance in demyelinating disorders. PMID:25852473

  5. Leucine-rich repeat-containing synaptic adhesion molecules as organizers of synaptic specificity and diversity.

    Science.gov (United States)

    Schroeder, Anna; de Wit, Joris

    2018-04-09

    The brain harbors billions of neurons that form distinct neural circuits with exquisite specificity. Specific patterns of connectivity between distinct neuronal cell types permit the transfer and computation of information. The molecular correlates that give rise to synaptic specificity are incompletely understood. Recent studies indicate that cell-surface molecules are important determinants of cell type identity and suggest that these are essential players in the specification of synaptic connectivity. Leucine-rich repeat (LRR)-containing adhesion molecules in particular have emerged as key organizers of excitatory and inhibitory synapses. Here, we discuss emerging evidence that LRR proteins regulate the assembly of specific connectivity patterns across neural circuits, and contribute to the diverse structural and functional properties of synapses, two key features that are critical for the proper formation and function of neural circuits.

  6. Ankyrins: Roles in synaptic biology and pathology.

    Science.gov (United States)

    Smith, Katharine R; Penzes, Peter

    2018-05-03

    Ankyrins are broadly expressed adaptors that organize diverse membrane proteins into specialized domains and link them to the sub-membranous cytoskeleton. In neurons, ankyrins are known to have essential roles in organizing the axon initial segment and nodes of Ranvier. However, recent studies have revealed novel functions for ankyrins at synapses, where they organize and stabilize neurotransmitter receptors, modulate dendritic spine morphology and control adhesion to the presynaptic site. Ankyrin genes have also been highly associated with a range of neurodevelopmental and psychiatric diseases, including bipolar disorder, schizophrenia and autism, which all demonstrate overlap in their genetics, mechanisms and phenotypes. This review discusses the novel synaptic functions of ankyrin proteins in neurons, and places these exciting findings in the context of ANK genes as key neuropsychiatric disorder risk-factors. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Alzheimer's disease: synaptic dysfunction and Abeta

    LENUS (Irish Health Repository)

    Shankar, Ganesh M

    2009-11-23

    Abstract Synapse loss is an early and invariant feature of Alzheimer\\'s disease (AD) and there is a strong correlation between the extent of synapse loss and the severity of dementia. Accordingly, it has been proposed that synapse loss underlies the memory impairment evident in the early phase of AD and that since plasticity is important for neuronal viability, persistent disruption of plasticity may account for the frank cell loss typical of later phases of the disease. Extensive multi-disciplinary research has implicated the amyloid β-protein (Aβ) in the aetiology of AD and here we review the evidence that non-fibrillar soluble forms of Aβ are mediators of synaptic compromise. We also discuss the possible mechanisms of Aβ synaptotoxicity and potential targets for therapeutic intervention.

  8. Optogenetic acidification of synaptic vesicles and lysosomes.

    Science.gov (United States)

    Rost, Benjamin R; Schneider, Franziska; Grauel, M Katharina; Wozny, Christian; Bentz, Claudia; Blessing, Anja; Rosenmund, Tanja; Jentsch, Thomas J; Schmitz, Dietmar; Hegemann, Peter; Rosenmund, Christian

    2015-12-01

    Acidification is required for the function of many intracellular organelles, but methods to acutely manipulate their intraluminal pH have not been available. Here we present a targeting strategy to selectively express the light-driven proton pump Arch3 on synaptic vesicles. Our new tool, pHoenix, can functionally replace endogenous proton pumps, enabling optogenetic control of vesicular acidification and neurotransmitter accumulation. Under physiological conditions, glutamatergic vesicles are nearly full, as additional vesicle acidification with pHoenix only slightly increased the quantal size. By contrast, we found that incompletely filled vesicles exhibited a lower release probability than full vesicles, suggesting preferential exocytosis of vesicles with high transmitter content. Our subcellular targeting approach can be transferred to other organelles, as demonstrated for a pHoenix variant that allows light-activated acidification of lysosomes.

  9. E2F1-mediated human POMC expression in ectopic Cushing's syndrome.

    Science.gov (United States)

    Araki, Takako; Liu, Ning-Ai; Tone, Yukiko; Cuevas-Ramos, Daniel; Heltsley, Roy; Tone, Masahide; Melmed, Shlomo

    2016-11-01

    Cushing's syndrome is caused by excessive adrenocorticotropic hormone (ACTH) secretion derived from pituitary corticotroph tumors (Cushing disease) or from non-pituitary tumors (ectopic Cushing's syndrome). Hypercortisolemic features of ectopic Cushing's syndrome are severe, and no definitive treatment for paraneoplastic ACTH excess is available. We aimed to identify subcellular therapeutic targets by elucidating transcriptional regulation of the human ACTH precursor POMC (proopiomelanocortin) and ACTH production in non-pituitary tumor cells and in cell lines derived from patients with ectopic Cushing's syndrome. We show that ectopic hPOMC transcription proceeds independently of pituitary-specific Tpit/Pitx1 and demonstrate a novel E2F1-mediated transcriptional mechanism regulating hPOMC We identify an E2F1 cluster binding to the proximal hPOMC promoter region (-42 to +68), with DNA-binding activity determined by the phosphorylation at Ser-337. hPOMC mRNA expression in cancer cells was upregulated (up to 40-fold) by the co-expression of E2F1 and its heterodimer partner DP1. Direct and indirect inhibitors of E2F1 activity suppressed hPOMC gene expression and ACTH by modifying E2F1 DNA-binding activity in ectopic Cushing's cell lines and primary tumor cells, and also suppressed paraneoplastic ACTH and cortisol levels in xenografted mice. E2F1-mediated hPOMC transcription is a potential target for suppressing ACTH production in ectopic Cushing's syndrome. © 2016 Society for Endocrinology.

  10. Shank synaptic scaffold proteins: keys to understanding the pathogenesis of autism and other synaptic disorders.

    Science.gov (United States)

    Sala, Carlo; Vicidomini, Cinzia; Bigi, Ilaria; Mossa, Adele; Verpelli, Chiara

    2015-12-01

    Shank/ProSAP proteins are essential to synaptic formation, development, and function. Mutations in the family of SHANK genes are strongly associated with autism spectrum disorders (ASD) and other neurodevelopmental and neuropsychiatric disorders, such as intellectual disability (ID), and schizophrenia. Thus, the term 'Shankopathies' identifies a number of neuronal diseases caused by alteration of Shank protein expression leading to abnormal synaptic development. With this review we want to summarize the major genetic, molecular, behavior and electrophysiological studies that provide new clues into the function of Shanks and pave the way for the discovery of new therapeutic drugs targeted to treat patients with SHANK mutations and also patients affected by other neurodevelopmental and neuropsychiatric disorders. Shank/ProSAP proteins are essential to synaptic formation, development, and function. Mutations in the family of SHANK genes are strongly associated with autism spectrum disorders (ASD) and other neurodevelopmental and neuropsychiatric disorders, such as intellectual disability (ID), and schizophrenia (SCZ). With this review we want to summarize the major genetic, molecular, behavior and electrophysiological studies that provide new clues into the function of Shanks and pave the way for the discovery of new therapeutic drugs targeted to treat patients with SHANK mutations. © 2015 International Society for Neurochemistry.

  11. Spine Calcium Transients Induced by Synaptically-Evoked Action Potentials Can Predict Synapse Location and Establish Synaptic Democracy

    Science.gov (United States)

    Meredith, Rhiannon M.; van Ooyen, Arjen

    2012-01-01

    CA1 pyramidal neurons receive hundreds of synaptic inputs at different distances from the soma. Distance-dependent synaptic scaling enables distal and proximal synapses to influence the somatic membrane equally, a phenomenon called “synaptic democracy”. How this is established is unclear. The backpropagating action potential (BAP) is hypothesised to provide distance-dependent information to synapses, allowing synaptic strengths to scale accordingly. Experimental measurements show that a BAP evoked by current injection at the soma causes calcium currents in the apical shaft whose amplitudes decay with distance from the soma. However, in vivo action potentials are not induced by somatic current injection but by synaptic inputs along the dendrites, which creates a different excitable state of the dendrites. Due to technical limitations, it is not possible to study experimentally whether distance information can also be provided by synaptically-evoked BAPs. Therefore we adapted a realistic morphological and electrophysiological model to measure BAP-induced voltage and calcium signals in spines after Schaffer collateral synapse stimulation. We show that peak calcium concentration is highly correlated with soma-synapse distance under a number of physiologically-realistic suprathreshold stimulation regimes and for a range of dendritic morphologies. Peak calcium levels also predicted the attenuation of the EPSP across the dendritic tree. Furthermore, we show that peak calcium can be used to set up a synaptic democracy in a homeostatic manner, whereby synapses regulate their synaptic strength on the basis of the difference between peak calcium and a uniform target value. We conclude that information derived from synaptically-generated BAPs can indicate synapse location and can subsequently be utilised to implement a synaptic democracy. PMID:22719238

  12. Properties of rapidly solidified Fe-Cr-Al ribbons for the use as automotive exhaust gas catalyst substrates

    International Nuclear Information System (INIS)

    Emmerich, K.

    1993-01-01

    Metallic honeycomb structures are used as catalyst substrates in automotive exhaust gas systems. This application requires an outstanding corrosion resistance at elevated temperatures of the substrate material. Technical improvements can be achieved by the use of rapid solidification technology for the production of the Fe-Cr-Al ribbons since the Al content can be substantially increased from about 5% Al in the conventionally rolled material to about 12% Al in the rapid solidified ribbon. As a result the lifetime of the ribbon in a higher-temperature corrosion environment is drastically increased. In addition the scale/metal adherance is improved. The impediment of recrystallization in the rapidly solidified ribbons prevents an embrittlement even in carbonizing atmospheres. (orig.)

  13. Impact of morphometry, myelinization and synaptic current strength on spike conduction in human and cat spiral ganglion neurons.

    Directory of Open Access Journals (Sweden)

    Frank Rattay

    Full Text Available Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction.Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA synaptic stimuli.Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea compared to the cat cochlea.

  14. Impact of Morphometry, Myelinization and Synaptic Current Strength on Spike Conduction in Human and Cat Spiral Ganglion Neurons

    Science.gov (United States)

    Rattay, Frank; Potrusil, Thomas; Wenger, Cornelia; Wise, Andrew K.; Glueckert, Rudolf; Schrott-Fischer, Anneliese

    2013-01-01

    Background Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction. Methodology/Principal Findings Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs) along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA) synaptic stimuli. Conclusions/Significance Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea compared to the cat

  15. Controlling the microstructure and associated magnetic properties of Ni0.2Mn3.2Ga0.6 melt-spun ribbons by annealing

    Directory of Open Access Journals (Sweden)

    Mahmud Khan

    2017-05-01

    Full Text Available Here we report on the structural and magnetic properties of Ni0.2Mn3.2Ga0.6 melt-spun ribbons. The as-spun ribbons were found to exhibit mixed cubic phases that transform to non-cubic structure upon annealing. Additionally, an amorphous phase was found to co-exist in all ribbons. The SEM images show that minor grain formation occurs on the as-spun ribbons. However, the formation of extensive nano-grains was observed on the surfaces of the annealed ribbons. While the as-spun ribbons exhibit predominantly paramagnetic behavior, the ribbons annealed under various thermal conditions were found to be ferromagnetic with a Curie temperature of about 380 K. The ribbons annealed at 450 °C for 30 minutes exhibit a large coercive field of about 2500 Oe. The experimental results show that the microstructure and associated magnetic properties of the ribbons can be controlled by annealing techniques. The coercive fields and the shape of the magnetic hysteresis loops vary significantly with annealing conditions. Exchange bias effects have also been observed in the annealed ribbons.

  16. Ectopic Liver Tissue Formation in Rats with Induced Liver Fibrosis

    Directory of Open Access Journals (Sweden)

    Bauyrzhan Umbayev

    2014-12-01

    Full Text Available Introduction: The possible alternative approach to whole-organ transplantation is a cell-based therapy, which can also be used as a "bridge" to liver transplantation.  However, morphological and functional changes in the liver of patients suffering from chronic liver fibrosis and cirrhosis restrict the effectiveness of direct cell transplantation. Therefore, extra hepatic sites for cell transplantation, including the spleen, pancreas, peritoneal cavity, and subrenal capsule, could be a useful therapeutic approach for compensation of liver functions. However, a method of transplantation of hepatocytes into ectopic sites is needed to improve hepatocyte engraftment. Previously published data has demonstrated that mouse lymph nodes can support the engraftment and proliferation of hepatocytes as ES and rescue Fah mice from lethal liver failure. Thus, the aim of the study was to evaluate the engraftment of i.p. injected allogeneic hepatocytes into extra hepatic sites in albino rats with chemically induced liver fibrosis (LF. Materials and methods: Albino rats were randomly divided into 4 groups: (1 intact group (n = 18; (2 rats with induced LF (n = 18; (3 rats with induced LF and transplanted with hepatocytes (n = 18; (4 as a control, rats were treated with cyclosporine A only (n = 18. In order to prevent an immune response, groups 2 and 3 were subjected to immunosuppression by cyclosporine A (25 mg/kg per day. LF was induced using N-nitrosodimethylamine (NDMA, i.p., 10 mg/kg, three times a week for 4 weeks and confirmed by histological analysis of the liver samples. Hepatocytes transplantation (HT was performed two days after NDMA exposure cessation by i.p. injection of 5×106 freshly isolated allogeneic hepatocytes. Liver function was assessed by quantifying blood biochemical parameters (ALT, AST, GGT, total protein, bilirubin, and albumin at 1 week, 1 month, and 2 months after hepatocytes transplantation (HT. To confirm a hepatocytes

  17. Variation of magnetic properties with mischmetal content in the resource saving magnets of MM-Fe-B ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhu-bai, E-mail: lzbgj@163.com [Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Li-chen [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Geng, Xiao-peng [Inner Mongolia Baotou Steel Rare Earth Magnetic Materials Co.Ltd, Baotou 014030 (China); Hu, Feng-xia; Sun, Ji-rong; Shen, Bao-gen [State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2017-03-15

    Magnetic materials of MM-Fe-B (MM=mischmetal) ribbons were prepared using melt spinning method by varying the content of MM. The ribbons contain minor phases besides the main phase of Re{sub 2}Fe{sub 14}B. X-ray techniques show that the diffraction peak intensities of the minor phase Fe{sub 3}B vary with the content of constituent elements, indicating that the amount of minor phase could be tunable. The squareness of hysteresis loop is the best in MM{sub 13}Fe{sub 80.5}B{sub 6.5} ribbons, which should mainly ascribe to the less amount of minor phase. Henkel plots verify the more uniform magnetization reversals in MM{sub 13}Fe{sub 80.5}B{sub 6.5} ribbons, and the energy product achieves to the maximum of 12.74 MGOe with the coercivity of 6.50 kOe. With the increase of MM content the coercivity increases monotonically, and reaches to 9.13 kOe in MM{sub 15}Fe{sub 77.5}B{sub 7.5} ribbons, which should be related with the nature of the defects in the main phase. These investigations show that optimizing the content of constituent elements and phase constitution could improve magnetic properties in the resource-saving magnets of MM-Fe-B ribbons. - Highlights: • MM-Fe-B (MM=mischmetal) ribbons contains the minor phases besides the main phase of Re{sub 2}Fe{sub 14}B. • The amount of minor phases varies with the content of constituent elements. • The energy product of 12.74 MGOe is obtained in MM{sub 13}Fe{sub 80.5}B{sub 6.5} ribbons by optimizing the phase constitution.

  18. Synapse geometry and receptor dynamics modulate synaptic strength.

    Directory of Open Access Journals (Sweden)

    Dominik Freche

    Full Text Available Synaptic transmission relies on several processes, such as the location of a released vesicle, the number and type of receptors, trafficking between the postsynaptic density (PSD and extrasynaptic compartment, as well as the synapse organization. To study the impact of these parameters on excitatory synaptic transmission, we present a computational model for the fast AMPA-receptor mediated synaptic current. We show that in addition to the vesicular release probability, due to variations in their release locations and the AMPAR distribution, the postsynaptic current amplitude has a large variance, making a synapse an intrinsic unreliable device. We use our model to examine our experimental data recorded from CA1 mice hippocampal slices to study the differences between mEPSC and evoked EPSC variance. The synaptic current but not the coefficient of variation is maximal when the active zone where vesicles are released is apposed to the PSD. Moreover, we find that for certain type of synapses, receptor trafficking can affect the magnitude of synaptic depression. Finally, we demonstrate that perisynaptic microdomains located outside the PSD impacts synaptic transmission by regulating the number of desensitized receptors and their trafficking to the PSD. We conclude that geometrical modifications, reorganization of the PSD or perisynaptic microdomains modulate synaptic strength, as the mechanisms underlying long-term plasticity.

  19. Ectopic origin of bronchial arteries: assessment with multidetector helical CT angiography

    International Nuclear Information System (INIS)

    Hartmann, Ieneke J.C.; Remy-Jardin, Martine; Menchini, Laura; Teisseire, Antoine; Khalil, Chadi; Remy, Jacques

    2007-01-01

    The purpose of this study was to determine non-invasively the frequency of ectopic bronchial arteries (BA) (i.e., bronchial arteries originating at a level of the descending aorta other than T5-T6 or from any aortic collateral vessel) on multidetector-row CT angiograms (CTA) obtained in patients with hemoptysis. Over a 5-year period (2000-2005), 251 consecutive patients with hemoptysis underwent multidetector-row CT angiography of the thorax. From this population, 37 patients were excluded because of a suboptimal CTA examination (n = 19), the presence of extensive mediastinal disease (n = 15) or severe chest deformation (n = 3) precluding any precise analysis of the bronchial arteries at CTA. Our final study group included 214 patients who underwent a thin-collimated CT angiogram (contrast agent: 300 to 350 mg/ml) on a 4- (n = 56), 16- (n = 119) and 64- (n = 39) detector-row scanner. The site of origin and distribution of bronchial arteries were analyzed on transverse CT scans, maximum intensity projections and volume-rendered images. The site of the ostium of a bronchial artery was coded as orthotopic when the artery originated from the descending aorta between the levels of the fifth and sixth thoracic vertebrae; all other bronchial arteries were considered ectopic. From the studied population, 137 (64%) patients had only orthotopic bronchial arteries, whereas 77 patients (36%) had at least one bronchial artery of ectopic origin. A total of 147 ectopic arteries were depicted, originating as common bronchial trunks (n = 23; 19%) or isolated right or left bronchial arteries (n = 101; 81%). The most frequent sites of origin of the 124 ostiums were the concavity of the aortic arch (92/124; 74%), the subclavian artery (13/124; 10.5%) and the descending aorta (10/124; 8.5%). The isolated ectopic bronchial arteries supplied the ipsilateral lung in all but three cases. Bronchial artery embolization was indicated in 26 patients. On the basis of CTA information, (1

  20. Clinical course of ectopic pregnancy: A single-center experience

    Directory of Open Access Journals (Sweden)

    Aqueela Ayaz

    2013-01-01

    Full Text Available Objectives: The objective was to highlight the frequency, clinical profile, and predisposing factors of ectopic pregnancy (EP in a general hospital. Materials and Methods: This descriptive study was conducted at the Obstetrics and Gynaecology department of Hera General hospital, Makkah, Saudi Arabia, from July 1, 2009 to December 29, 2010. Data were collected on chief medical complaints, sociodemographic characteristics, past obstetrics and gynecological history, management done, and outcome of management. Data were analyzed using Microsoft Office Excel (version 2007. Results: Out of total 7564 pregnancies, 44 (0.58% patients were diagnosed as EP. Out of 44, 22 (50% patients presented within 24 h of onset of symptoms. Mean age was 28 ± 7 years. Multigravida were predominant in 25 (57%, and 21 (48% had gestational age of 6-8 weeks at the time of presentation; the common presenting features were amenorrhea (41, 93.2%, abdominal pain (39, 88.6%, and tenderness (38, 86%. Previous pelvic surgery (13, 29.5%, infertility treatment (11, 25%, and pelvic inflammatory disease (10, 22.7% were the common predisposing factors. Twenty-five (57% presented with ruptured EP and were operated within 24 h, and the remaining were kept under observation till further diagnosis. After confirming the diagnosis, 12/19 underwent laparoscopy, whereas 7/19 received medical treatment. Surgery confirmed fallopian tube pregnancies in 35 (94.5%. No mortality was observed. Conclusion: Previous pelvic surgeries were the major etiological factor for EP. Other factors were infertility treatment and pelvic inflammatory disease. The most common site of EP was fallopian tubes.

  1. Morphometry of Hilar Ectopic Granule Cells in the Rat

    Science.gov (United States)

    Pierce, Joseph P.; McCloskey, Daniel P.; Scharfman, Helen E.

    2014-01-01

    Granule cell (GC) neurogenesis in the dentate gyrus (DG) does not always proceed normally. After severe seizures (e.g., status epilepticus [SE]) and some other conditions, newborn GCs appear in the hilus. Hilar ectopic GCs (EGCs) can potentially provide insight into the effects of abnormal location and seizures on GC development. Additionally, hilar EGCs that develop after SE may contribute to epileptogenesis and cognitive impairments that follow SE. Thus, it is critical to understand how EGCs differ from normal GCs. Relatively little morphometric information is available on EGCs, especially those restricted to the hilus. This study quantitatively analyzed the structural morphology of hilar EGCs from adult male rats several months after pilocarpineinduced SE, when they are considered to have chronic epilepsy. Hilar EGCs were physiologically identified in slices, intracellularly labeled, processed for light microscopic reconstruction, and compared to GC layer GCs, from both the same post-SE tissue and the NeuroMorpho database (normal GCs). Consistently, hilar EGC and GC layer GCs had similar dendritic lengths and field sizes, and identifiable apical dendrites. However, hilar EGC dendrites were topologically more complex, with more branch points and tortuous dendritic paths. Three-dimensional analysis revealed that, remarkably, hilar EGC dendrites often extended along the longitudinal DG axis, suggesting increased capacity for septotemporal integration. Axonal reconstruction demonstrated that hilar EGCs contributed to mossy fiber sprouting. This combination of preserved and aberrant morphological features, potentially supporting convergent afferent input to EGCs and broad, divergent efferent output, could help explain why the hilar EGC population could impair DG function. PMID:21344409

  2. Modeling the excitation of graphene plasmons in periodic grids of graphene ribbons: An analytical approach

    DEFF Research Database (Denmark)

    Gonçalves, P:A.D.; Dias, E. J. C.; Bludov, Yu V.

    2016-01-01

    We study electromagnetic scattering and subsequent plasmonic excitations in periodic grids of graphene ribbons. To address this problem, we develop an analytical method to describe the plasmon-assisted absorption of electromagnetic radiation by a periodic structure of graphene ribbons forming...... a diffraction grating for THz and mid-IR light. The major advantage of this method lies in its ability to accurately describe the excitation of graphene surface plasmons (GSPs) in one-dimensional (1D) graphene gratings without the use of both time-consuming, and computationally demanding full-wave numerical...... compare the theoretical data with spectra taken from experiments, for which we observe a very good agreement. These theoretical tools may therefore be applied to design new experiments and cutting-edge nanophotonic devices based on graphene plasmonics....

  3. Mn-silicide nanostructures aligned on massively parallel silicon nano-ribbons

    International Nuclear Information System (INIS)

    De Padova, Paola; Ottaviani, Carlo; Ronci, Fabio; Colonna, Stefano; Quaresima, Claudio; Cricenti, Antonio; Olivieri, Bruno; Dávila, Maria E; Hennies, Franz; Pietzsch, Annette; Shariati, Nina; Le Lay, Guy

    2013-01-01

    The growth of Mn nanostructures on a 1D grating of silicon nano-ribbons is investigated at atomic scale by means of scanning tunneling microscopy, low energy electron diffraction and core level photoelectron spectroscopy. The grating of silicon nano-ribbons represents an atomic scale template that can be used in a surface-driven route to control the combination of Si with Mn in the development of novel materials for spintronics devices. The Mn atoms show a preferential adsorption site on silicon atoms, forming one-dimensional nanostructures. They are parallel oriented with respect to the surface Si array, which probably predetermines the diffusion pathways of the Mn atoms during the process of nanostructure formation.

  4. Laser assisted crystallization of ferromagnetic amorphous ribbons: A multimodal characterization and thermal model study

    Energy Technology Data Exchange (ETDEWEB)

    Katakam, Shravana; Santhanakrishnan, S.; Smith, Casey; Banerjee, Rajarshi; Dahotre, Narendra B. [Laboratory of Laser Materials Processing and Synthesis Department of Materials Science and Engineering University of North Texas, Denton, Texas 76207 (United States); Devaraj, Arun; Bowden, Mark; Thevuthasan, Suntharampillai [William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Ramanujan, R. V. [Schhol of Materials Science and Engineering Nanyang Technological University, Singapore 639798 (Singapore)

    2013-11-14

    This paper focuses on laser-based de-vitrification of amorphous soft magnetic Fe-Si-B ribbons and its consequent influence on the magnetic properties. Laser processing resulted in a finer scale of crystallites due to rapid heating and cooling during laser annealing compared to conventional furnace annealing process. A significant increase in saturation magnetization is observed for laser-annealed ribbons compared to both as-received and furnace annealed samples coupled with an increase in coercivity compared to the as received samples. The combined effect of thermal histories and stresses developed during laser annealing results in the formation of nano-crystalline phase along the laser track. The phase evolution is studied by micro-XRD and TEM analysis. Solute partitioning and compositional variation within the phases are obtained by Local Electrode Atom probe analysis. The evolution of microstructure is rationalized using a Finite Element based heat transfer multi-physics model.

  5. Flat-plate solar array project. Volume 3: Silicon sheet: Wafers and ribbons

    Science.gov (United States)

    Briglio, A.; Dumas, K.; Leipold, M.; Morrison, A.

    1986-01-01

    The primary objective of the Silicon Sheet Task of the Flat-Plate Solar Array (FSA) Project was the development of one or more low cost technologies for producing silicon sheet suitable for processing into cost-competitive solar cells. Silicon sheet refers to high purity crystalline silicon of size and thickness for fabrication into solar cells. Areas covered in the project were ingot growth and casting, wafering, ribbon growth, and other sheet technologies. The task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the task cost goals were not achieved.

  6. Megalencephaly, polymicrogyria and ribbon-like band heterotopia: A new cortical malformation.

    Science.gov (United States)

    Kobayashi, Yu; Magara, Shinichi; Okazaki, Kenichi; Komatsubara, Takao; Saitsu, Hirotomo; Matsumoto, Naomichi; Kato, Mitsuhiro; Tohyama, Jun

    2016-11-01

    Megalencephalic polymicrogyria syndromes include megalencephaly-capillary malformation and megalencephaly-polymicrogyria-polydactyly-hydrocephalus. Recent genetic studies have identified that genes in the PI3K-AKT pathway are involved in the pathogenesis of these disorders. Herein, we report a patient who presented with developmental delay, epilepsy and peculiar neuroimaging findings of megalencephaly, polymicrogyria, and symmetrical band heterotopia in the periventricular region. The heterotopias exhibited inhomogeneous signals with undulatory mixtures of gray and white matter, resembling ribbon-like heterotopia, with a predominance in the temporal to occipital regions. These neuroradiological findings were not consistent with those in known megalencephalic polymicrogyria syndromes. No genetic abnormality was identified through whole-exome sequencing. The neuroimaging findings of this patient may represent a novel cortical malformation involving megalencephaly with polymicrogyria and ribbon-like band heterotopia. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  7. Ribbon scanning confocal for high-speed high-resolution volume imaging of brain.

    Directory of Open Access Journals (Sweden)

    Alan M Watson

    Full Text Available Whole-brain imaging is becoming a fundamental means of experimental insight; however, achieving subcellular resolution imagery in a reasonable time window has not been possible. We describe the first application of multicolor ribbon scanning confocal methods to collect high-resolution volume images of chemically cleared brains. We demonstrate that ribbon scanning collects images over ten times faster than conventional high speed confocal systems but with equivalent spectral and spatial resolution. Further, using this technology, we reconstruct large volumes of mouse brain infected with encephalitic alphaviruses and demonstrate that regions of the brain with abundant viral replication were inaccessible to vascular perfusion. This reveals that the destruction or collapse of large regions of brain micro vasculature may contribute to the severe disease caused by Venezuelan equine encephalitis virus. Visualization of this fundamental impact of infection would not be possible without sampling at subcellular resolution within large brain volumes.

  8. Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons

    Science.gov (United States)

    Nikitin, A. Yu.; Guinea, F.; Garcia-Vidal, F. J.; Martin-Moreno, L.

    2012-02-01

    Resonance diffraction in the periodic array of graphene microribbons is theoretically studied following a recent experiment [L. Ju , Nature Nanotech.1748-338710.1038/nnano.2011.146 6, 630 (2011)]. Systematic studies over a wide range of parameters are presented. It is shown that a much richer resonant picture would be observable for higher relaxation times of charge carriers: More resonances appear and transmission can be totally suppressed. The comparison with the absorption cross-section of a single ribbon shows that the resonant features of the periodic array are associated with leaky plasmonic modes. The longest-wavelength resonance provides the highest visibility of the transmission dip and has the strongest spectral shift and broadening with respect to the single-ribbon resonance, due to collective effects.

  9. Effects of material non-linearity on the residual stresses in a dendritic silicon crystal ribbon

    Science.gov (United States)

    Ray, Sujit K.; Utku, Senol

    1990-01-01

    Thermal stresses developed in a dendritic silicon crystal ribbon have been shown to cause plastic deformation and residual stresses in the ribbon. This paper presents an implementation of a numerical model proposed for thermoelastoplastic behavior of a material. The model has been used to study the effects of plasticity of silicon on the residual stresses. The material properties required to implement this model are all assumed, and the response of the material to the variations in these assumed parameters of the constitutive law and in the finite element mesh is investigated. The steady state growth process is observed to be periodic with nonzero residual stresses. Numerical difficulties are also encountered in the computer solution process, resulting in sharp jumps and large oscillations in the stress responses.

  10. Mössbauer and Kerr microscopy investigation of crystallization in FeCoB ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, V. Raghavendra, E-mail: varimalla@yahoo.com, E-mail: vrreddy@csr.res.in; Hussain, Zaineb; Babu, Hari [UGC DAE Consortium for Scientific Research, University Campus, Kandhwa Road, Indore-452001 India (India); Shrivastava, Namrata [School of Physics, DAVV, Khandwa Road, Indore – 452001 India (India); Gupta, Ajay [Amity Centre for Spintronic Materials, Amity University, Noida 201303.India (India)

    2016-05-23

    The present work reports the crystallization study of amorphous FeCoB ribbons using x-ray diffraction, {sup 57}Fe Mössbauer spectroscopy in transmission mode and magneto-optical Kerr (MOKE) microscopy. Annealing at 673 K is found to result in crystallization. From the Mossbauer measurements it is observed that the Fe magnetic moments are in the plane of sample for as-cast ribbon; α-FeCo, (Fe{sub 0.5}Co{sub 0.5}){sub 2}B and Fe{sub 2}B phases are formed after crystallization. MOKE microscopy revealed that wide 180° domain walls & narrow fingerprint domains are observed before crystallization and fine domains are observed after crystallization. The results are explained in terms of the presence of internal stresses and their annealing with thermal heat treatment.

  11. Magnetic properties of fcc (Co95Fe5)1-xAlx ribbons

    International Nuclear Information System (INIS)

    Makhlouf, Salah A.; Parker, F.T.; Benameur, T.

    1999-01-01

    Rapidly quenched (Co 95 Fe 5 ) 1-x Al x ribbons are investigated by X-ray diffraction, magnetization, and Moessbauer effect measurements. A single fcc phase is obtained for all ribbons x ≤ 10 at.%. The lattice constant increases linearly with x and is discussed in connection with magnetic moment. The influence of Al substitution on both magnetization and Fe-atom hyperfine field (H) is studied. At 296 K, the magnetization decreases linearly while H drops nonlinearly as x increases. Al substitution leads to substantial differences in iron hyperfine fields in bcc and fcc systems. Fe moment is perturbed differently by Al substitution in fcc (Co 95 Fe 5 ) 1-x Al x and bcc Fe-Al systems

  12. Corrosion-resistant amorphous alloy ribbons for electromagnetic filtration of iron rusts from water

    International Nuclear Information System (INIS)

    Kawashima, Asahi; Asami, Katsuhiko; Sato, Takeaki; Hashimoto, Koji

    1985-01-01

    An attempt was made to use corrosion-resistant amorphous Fe-9Cr-13P-7C alloy ribbons as an electromagnetic filter material for trapping various iron rusts suspended in water at 40 0 C. The ferrimagnetic Fe 3 O 4 rust was trapped with the 100 % efficiency and paramagnetic rusts such as α-Fe 2 O 3 , α-FeOOH and amorphous ferric oxyhydroxide were trapped with certain efficiencies at the magnetic field strength of 0.5-10 kOe. The regeneration of the filter by back-washing was easy. The trapping capacity of electromagnetic filter was proportional to the edge length of the filter material where the high magnetic field strength existed. Therefore, melt-spun thin and narrow amorphous alloy ribbons having the high corrosion resistance have the potential utility as electromagnetic filter material. (author)

  13. Comparison of mechanical behavior between bulk and ribbon Cu-based metallic glasses

    International Nuclear Information System (INIS)

    Jiang, W.H.; Liu, F.X.; Wang, Y.D.; Zhang, H.F.; Choo, H.; Liaw, P.K.

    2006-01-01

    As-cast bulk and as-spun ribbon Cu 60 Zr 30 Ti 10 metallic glasses were characterized using differential-scanning calorimetry and instrumented nanoindentation. Two alloys show a significant difference in the amount of free volume, which is attributed to the difference in a cooling rate, while exhibiting a similar serrated plastic flow. Atomic-force-microscopy observations demonstrate the pile-ups containing shear bands around the indents in both alloys. The as-cast bulk alloy has higher hardness and elastic modulus than the as-spun ribbon alloy. The difference in the strengths of two alloys may be related to the different amount of free volume. The strength seems to be more sensitive to a cooling rate during solidification than the plastic-flow behavior in the Cu 60 Zr 30 Ti 10

  14. Manifold-splitting regularization, self-linking, twisting, writhing numbers of space-time ribbons

    International Nuclear Information System (INIS)

    Tze, C.H.

    1988-01-01

    The authors present an alternative formulation of Polyakov's regularization of Gauss' integral formula for a single closed Feynman path. A key element in his proof of the D = 3 fermi-bose transmutations induced by topological gauge fields, this regularization is linked here with the existence and properties of a nontrivial topological invariant for a closed space ribbon. This self-linking coefficient, an integer, is the sum of two differential characteristics of the ribbon, its twisting and writhing numbers. These invariants form the basis for a physical interpretation of our regularization. Their connection to Polyakov's spinorization is discussed. The authors further generalize their construction to the self-linking, twisting and writhing of higher dimensional d = eta(odd) submanifolds in D = (2eta + 1) space-time

  15. Fabrication of Fe-6.5wt%Si Ribbons by Melt Spinning Method on Large Scale

    Directory of Open Access Journals (Sweden)

    Y. F. Liang

    2015-01-01

    Full Text Available Melt spinning method has been widely applied for fabrication of Fe-based amorphous/nanocrystalline ribbons in industry. Compared with Fe-based amorphous/nanocrystalline alloys, Fe-6.5wt%Si high silicon steel is of low cost and has comparable excellent soft magnetic properties. Due to higher melting point and absence of supercooled liquid region, fabrication of Fe-6.5wt%Si ribbons is very hard and is only on lab scale. In this paper, we report that large scale fabrication of Fe-6.5wt%Si ribbons was successful and microstructures, ordered structures, and mechanical and soft magnetic properties of the ribbons were investigated. Due to rapid solidification rate, the ribbons were of ultrafine grains, and low degree of order and exhibited some extent of bending and tensile ductility. After heat treatment, excellent soft magnetic properties were obtained. Due to near-zero magnetostriction, the ribbons are promising to be used in electric devices with high frequencies where low noises are required.

  16. Ectopic pregnancy morbidity and mortality in low-income women, 2004-2008.

    Science.gov (United States)

    Stulberg, D B; Cain, L; Dahlquist, I H; Lauderdale, D S

    2016-03-01

    Does the risk of adverse outcomes at the time of ectopic pregnancy vary by race/ethnicity among women receiving Medicaid, the public health insurance program for low-income people in the USA? Among Medicaid beneficiaries with ectopic pregnancy, 11% experienced at least one complication, and women from all racial/ethnic minority groups were significantly more likely than whites to experience complications. In this population of Medicaid recipients, African American women are significantly more likely than whites to experience ectopic pregnancy, but the risk of adverse outcomes has not previously been assessed. We conducted a cross-sectional observational study of all women (n = 19 135 106) ages 15-44 enrolled in Medicaid for any amount of time during 2004-2008 who lived in one of the following 14 US states: Arizona; California; Colorado; Florida; Illinois; Indiana; Iowa; Louisiana; Massachusetts; Michigan; Minnesota; Mississippi; New York; and Texas. We analyzed Medicaid claims records for inpatient and outpatient encounters and identified ectopic pregnancies with a principal diagnosis code for ectopic pregnancy from 2004-2008. We calculated the ectopic pregnancy complication rate as the number of ectopic pregnancies with at least one complication (blood transfusion, hysterectomy, any sterilization, or length-of-stay (LOS) > 2 days) divided by the total number of ectopic pregnancies. We used Poisson regression to assess the risk of ectopic pregnancy complication by race/ethnicity. Secondary outcomes were each individual complication, and ectopic pregnancy-related death. We calculated the ectopic pregnancy mortality ratio as the number of deaths divided by live births. Ectopic pregnancy-associated complications occurred in 11% of cases. Controlling for age and state, the risk of any complication was significantly higher among women who were black (incidence risk ratio [IRR] 1.47, 95% CI 1.43-1.53, P American Indian/Alaskan Native (IRR 1.34 95% CI 1.16-1.55, P white

  17. A Voltage Mode Memristor Bridge Synaptic Circuit with Memristor Emulators

    Directory of Open Access Journals (Sweden)

    Leon Chua

    2012-03-01

    Full Text Available A memristor bridge neural circuit which is able to perform signed synaptic weighting was proposed in our previous study, where the synaptic operation was verified via software simulation of the mathematical model of the HP memristor. This study is an extension of the previous work advancing toward the circuit implementation where the architecture of the memristor bridge synapse is built with memristor emulator circuits. In addition, a simple neural network which performs both synaptic weighting and summation is built by combining memristor emulators-based synapses and differential amplifier circuits. The feasibility of the memristor bridge neural circuit is verified via SPICE simulations.

  18. Surface and bulk magnetic properties of as-quenched FeNbB ribbons

    Czech Academy of Sciences Publication Activity Database

    Životský, O.; Postava, K.; Kraus, Luděk; Juraszek, J.; Jirásková, Yvonna; Teillet, J.; Barčová, K.; Švec, P.; Janičkovič, D.; Pištora, J.

    2008-01-01

    Roč. 320, č. 8 (2008), s. 1535-1540 ISSN 0304-8853 R&D Projects: GA ČR GA202/05/2111; GA AV ČR KAN400100653 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10100520 Keywords : Surface nanocrystallization * Fe-based ribbon * depth profile Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.283, year: 2008

  19. Silicon ribbon technology assessment 1978-1986 - A computer-assisted analysis using PECAN

    Science.gov (United States)

    Kran, A.

    1978-01-01

    The paper presents a 1978-1986 economic outlook for silicon ribbon technology based on the capillary action shaping technique. The outlook is presented within the framework of two sets of scenarios, which develop strategy for approaching the 1986 national energy capacity cost objective of $0.50/WE peak. The PECAN (Photovoltaic Energy Conversion Analysis) simulation technique is used to develop a 1986 sheet material price ($50/sq m) which apparently can be attained without further scientific breakthrough.

  20. Morphdynamics of Beaches in the Tróia-Sines Littoral Ribbon (SW Portugal)

    OpenAIRE

    Gama, Cristina; Andrade, César; Taborda, Rui; Freitas, Conceição

    2006-01-01

    In the Tróia-Sines littoral ribbon five beaches were monitored in order to evaluate morphological and textural changes. The textural analysis reveals a southward coarsening trend that reflects an increase in the wave energy. The morphodynamic data indicate that the modal stages are intermediate to reflective, and that the available beach volume increases southwards. During storm periods the volumetric changes reach 15% to 82% of the beach envelope corresponding to magnitudes of 6x10 3 to 2x10...

  1. Magnetocaloric properties of rapidly solidified Dy{sub 3}Co alloy ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Llamazares, J. L., E-mail: jose.sanchez@ipicyt.edu.mx; Flores-Zúñiga, H.; Sánchez-Valdés, C. F. [Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José 2055 Col. Lomas 4" a, San Luis Potosí, S.L.P. 78216 (Mexico); Álvarez-Alonso, Pablo [Departamento de Electricidad y Electrónica, UPV/EHU, 48940 Leioa (Spain); Lara Rodríguez, G. A. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, México, D. F. 04510 (Mexico); Fernández-Gubieda, M. L. [Departamento de Electricidad y Electrónica, UPV/EHU, 48940 Leioa (Spain); BC Materials, Camino de Ibaizabal, Edificio 500, Planta 1, Parque Científico y Tecnológico de Zamudio, 48160 Derio (Spain)

    2015-05-07

    The magnetic and magnetocaloric (MC) properties of melt-spun ribbons of the Dy{sub 3}Co intermetallic compound were investigated. Samples were fabricated in an Ar environment using a homemade melt spinner system at a linear speed of the rotating copper wheel of 40 ms{sup −1}. X-ray diffraction analysis shows that ribbons crystallize into a single-phase with the Fe{sub 3}C-type orthorhombic crystal structure. The M(T) curve measured at 5 mT reveals the occurrence of a transition at 32 K from a first to a second antiferromagnetic (AFM) state and an AFM-to-paramagnetic transition at T{sub N} = 43 K. Furthermore, a metamagnetic transition is observed below T{sub N}, but the magnetization change ΔM is well below the one reported for bulk alloys. Below 12 K, large inverse MC effect and hysteresis losses are observed. This behavior is related to the metamagnetic transition. For a magnetic field change of 5 T (2 T) applied along the ribbon length, the produced ribbons show a peak value of the magnetic entropy change ΔS{sub M}{sup peak} of −6.5 (− 2.1) Jkg{sup −1}K{sup −1} occurring close to T{sub N} with a full-width at half-maximum δT{sub FWHM} of 53 (37) K, and refrigerant capacity RC = 364 (83) Jkg{sup −1} (estimated from the product |ΔS{sub M}{sup peak}| × δT{sub FWHM})

  2. Microstructure, mechanical and functional properties of NiTi-based shape memory ribbons

    International Nuclear Information System (INIS)

    Mehrabi, K.; Bruncko, M.; Kneissl, A.C.

    2012-01-01

    Highlights: ► Melt-spun samples exhibited martensite structure and shape memory effects immediately after processing at room temperature. ► Using a new etchant and interference contrast, it is possible to reveal the fine microstructures and grain boundaries. ► The martensite structure in NiTi is very fine, and nano-sized twin boundaries could be revealed using TEM only. ► Two-way effects have been successfully introduced by different thermomechanical training methods in NiTi, NiTiCu and NiTiW alloys, which can be used for several applications, e.g. microsensors and microactuators. - Abstract: The present work has been aimed to study the microstructures, functional properties and the influence of different thermomechanical training methods on the two-way shape memory effect in NiTi-based melt-spun ribbons. In order to get small-dimensioned shape memory alloys (SMAs) with good functional and mechanical properties, a rapid solidification technique was employed. Their fracture and elasticity characteristics have been determined, as well as shape memory properties by thermomechanical cycling. The ribbons were trained under tensile and bending deformation by thermal cycling through the phase transformation temperature range. The results displayed that all different training methods were effective in developing a two-way shape memory effect (TWSME). The influence of copper (5–25 at.% Cu) and tungsten (2 at.% W) on the microstructure, and the functional and mechanical behavior of NiTi thin ribbons was also investigated. All samples show a shape memory effect immediately after processing without further heat treatment. The melt-spun ribbons were trained under constant strain (bending and tensile deformation) by thermal cycling through the phase transformation temperature range. The addition of copper was effective to narrow the transformation hysteresis. The W addition has improved the TWSME stability of the NiTi alloys and mechanical properties. Results about

  3. Adenine ribbon stabilized by Watson–Crick and Hoogsteen hydrogen Bonds: WFT and DFT study

    Czech Academy of Sciences Publication Activity Database

    Zierkiewicz, W.; Michalska, D.; Hobza, Pavel

    2010-01-01

    Roč. 12, č. 12 (2010), s. 2888-2894 ISSN 1463-9076 R&D Projects: GA MŠk LC512 Grant - others:Wroclaw University of Technology(PL) 343974/Z0304 Institutional research plan: CEZ:AV0Z40550506 Keywords : adenine ribbon * ab initio correlated calculations * self- organization Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.454, year: 2010

  4. Strain sensors for civil engineering application based on CoFeCrSiB amorphous ribbons

    Czech Academy of Sciences Publication Activity Database

    Bydžovský, J.; Kollár, M.; Jančárik, V.; Švec, P.; Kraus, Luděk

    2002-01-01

    Roč. 52, Suppl. A (2002), s. A117-A120 ISSN 0011-4626. [Czech and Slovak Conference on Magnetism. Košice, 20.08.2001-23.08.2001] Grant - others:NATO(XX) SfP973649; VEGA(XX) 1/7609/20 Institutional research plan: CEZ:AV0Z1010914 Keywords : magnetic amorphous ribbon * stress-induced anisotropy * strain sensor Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.311, year: 2002

  5. Frequency of ectopic pregnancy in a medical centre, Kingdom of Saudi Arabia

    International Nuclear Information System (INIS)

    Aziz, S.; Wafi, B.A.; Swadi, H.A.

    2011-01-01

    To asses the frequency of ectopic pregnancy and to evaluate the relevance of the risk factors in a Medical Center, Kingdom of Saudi Arabia (KSA). This retrospective study was done in Royal Commission Medical Centre, Yanbu Industrial City, KSA over a period of four years, where the medical records of patients with the diagnosis of ectopic pregnancy were reviewed. Data was collected on initial presentation, chief medical complaints, socio demographic characteristics, past obstetrics and gynaecological history, history of previous surgeries (tubal, ovarian and/or uterine), history of infertility and use of ovulation induction and history of contraception was obtained. A total of 66 cases were included in the study. Results: The frequency of ectopic pregnancy was 0.58% .Mean age was 30 +- 4 years. Multiparous women were found to be more prone to ectopic pregnancy (64%).Most frequent gestational age was 6-8 weeks. Majority (37.8%) of the patients had previous medical induced or spontaneous abortion. 18% had previous pelvic surgery, 15% used different treatments for infertility including ovulation induction, Intrauterine Insemination (IUI), and In vitro Fertilization (IVF) and 9% of patients had history of ectopic pregnancy, 4.5% of patients had Intrautrine Contraceptive Device (IUCD) in situ. 3% of patients had uterine fibroids. Conclusion: Study has found that previous abortions are major etiological factor for ectopic pregnancy. Further more the other factors were IUCD use, previous pelvic surgeries, infertility, previous ectopic and induced conception cycles which may be the result of a previous pelvic infection that may cause tubal sequelae. (author)

  6. Long-term effectiveness of surgical treatment of ectopic atrial tachycardia.

    Science.gov (United States)

    Prager, N A; Cox, J L; Lindsay, B D; Ferguson, T B; Osborn, J L; Cain, M E

    1993-07-01

    The purpose of this study was to determine the long-term clinical outcome of patients with ectopic atrial tachycardias treated surgically. Ectopic atrial tachycardia is an uncommon arrhythmia that can be symptomatic and is associated with the development of a cardiomyopathy. Management strategies are not well defined because of the paucity of data on the long-term effectiveness of pharmacologic and nonpharmacologic therapies. The long-term clinical impact of medical and surgical therapy was determined in 15 consecutive patients with ectopic atrial tachycardia. All 15 patients were initially treated with antiarrhythmic drugs (mean 5.7 +/- 2.2 drugs/patient). An effective drug regimen was identified in only 5 (33%) of the 15 patients; the remaining 10 patients were treated surgically. In each, individualized surgical procedures were guided by computer-assisted intraoperative mapping, with atrial plaques comprising up to 156 electrodes. Focal ablation was performed in four patients and atrial isolation procedures in six. The 10 patients treated surgically were followed up a mean of 4 +/- 3.2 years. Ectopic atrial tachycardia recurred in one patient. A permanent pacemaker was implanted in two patients, one of whom also required reoperation for constrictive pericarditis. There were no operative deaths. Ectopic atrial tachycardia recurred in three (60%) of the five patients discharged on antiarrhythmic drug therapy during a mean follow-up interval of 6.4 +/- 4.3 years. There was one nonarrhythmic death. Map-guided surgery demonstrated long-term efficacy in abolishing symptoms in 9 of the 10 patients with ectopic atrial tachycardia. Results demonstrate that surgery is effective for patients with ectopic atrial tachycardias who are not easily treated with antiarrhythmic drugs.

  7. Localization of endocardial ectopic activity by means of noninvasive endocardial surface current density reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Lai Dakun; Liu Chenguang; Eggen, Michael D; He Bin [Department of Biomedical Engineering, University of Minnesota, MN (United States); Iaizzo, Paul A, E-mail: binhe@umn.edu [Department of Surgery, University of Minnesota, MN (United States)

    2011-07-07

    Localization of the source of cardiac ectopic activity has direct clinical benefits for determining the location of the corresponding ectopic focus. In this study, a recently developed current-density (CD)-based localization approach was experimentally evaluated in noninvasively localizing the origin of the cardiac ectopic activity from body-surface potential maps (BSPMs) in a well-controlled experimental setting. The cardiac ectopic activities were induced in four well-controlled intact pigs by single-site pacing at various sites within the left ventricle (LV). In each pacing study, the origin of the induced ectopic activity was localized by reconstructing the CD distribution on the endocardial surface of the LV from the measured BSPMs and compared with the estimated single moving dipole (SMD) solution and precise pacing site (PS). Over the 60 analyzed beats corresponding to ten pacing sites (six for each), the mean and standard deviation of the distance between the locations of maximum CD value and the corresponding PSs were 16.9 mm and 4.6 mm, respectively. In comparison, the averaged distance between the SMD locations and the corresponding PSs was slightly larger (18.4 {+-} 3.4 mm). The obtained CD distribution of activated sources extending from the stimulus site also showed high consistency with the endocardial potential maps estimated by a minimally invasive endocardial mapping system. The present experimental results suggest that the CD method is able to locate the approximate site of the origin of a cardiac ectopic activity, and that the distribution of the CD can portray the propagation of early activation of an ectopic beat.

  8. Endoscopic Urinary Diversion As Initial Management of Symptomatic Obstructive Ectopic Ureter in Infants

    Directory of Open Access Journals (Sweden)

    Ruben Ortiz

    2017-09-01

    Full Text Available AimDefinitive surgery of ectopic ureter in infants is challenging. We propose an endoscopic urinary diversion (EUD as a novel surgical technique in the initial management of symptomatic obstructive ectopic ureter.Patients and methodsSixteen obstructive ectopic ureters (14 patients were initially treated by EUD between 2006 and 2015. All patients had urinary tract dilatation worsening at preoperative US scans and at least two febrile urinary tract infection (UTI or urinary sepsis despite antibiotic prophylaxis. Ectopic ureter was confirmed by cystoscopy. When ectopic meatus was not found, EUD consisted in the creation of a transurethral neo-orifice (TUNO performed by needle puncturing of the ureterovesical wall, under fluoroscopic and ultrasound control. If ectopic meatus was identified in the posterior urethra, “intravesicalization procedure” was done opening the urethral–ureteral wall to create a new ureteral outlet into the bladder.ResultsEUD was done at a median age of 3.5 months (0.5–7 with median follow-up of 48 months (24–136. TUNO was performed in six patients and “intravesicalization” in eight patients. Significant differences were observed in ureteral diameter and anteroposterior pelvis diameter before and after endoscopic treatment (p < 0.005. Initial renal function was preserved in all cases. Postoperative complications were UTI in four patients and TUNO stenosis in one patient, treated by endoscopic balloon dilation. Definitive treatment was further individualized in each patient after 1 year of life.ConclusionEUD is a feasible and safe less-invasive technique in the initial management of symptomatic obstructive ectopic ureter. It allows an adequate ureteral drainage preserving renal function until definitive repair if necessary and does not invalidate other surgical options in case of failure or future definitive treatments.

  9. Ectopic posterior pituitary high signal in preoperative and postoperative macroadenomas: dynamic MR imaging

    International Nuclear Information System (INIS)

    Takahashi, Takahiro; Miki, Yukio; Takahashi, Jun A.; Kanagaki, Mitsunori; Yamamoto, Akira; Fushimi, Yasutaka; Okada, Tsutomu; Haque, Tabassum Laz; Hashimoto, Nobuo; Konishi, Junji; Togashi, Kaori

    2005-01-01

    Background and purpose: In patients with macroadenoma, posterior pituitary high signal (PPHS) on T1-weighted magnetic resonance (MR) imaging is sometimes observed in an ectopic location. The present study compared incidences of ectopic PPHS before and after macroadenoma surgery using MR imaging, including dynamic MR imaging to ascertain whether this ectopic change is irreversible. Materials and methods: MR imaging was performed preoperatively in 111 cases of macroadenoma, and then repeated more than 1-year postoperatively in 47 patients. Enhancement of PPHS was assessed using dynamic MR imaging. Areas of enhanced hyperintensity were considered true PPHS, and the relationship between presence and location of true PPHS and adenoma volume was analyzed. Moreover, changes in the presence and location of true PPHS were ascertained among the patients who underwent postoperative follow-up MR imaging. Results: Preoperatively, PPHS was seen only in the normal location in 29 patients (Group A: 26.1%). High signal was detected only in an ectopic location in 58 patients, and early enhancement of this ectopic high signal was confirmed by dynamic MR imaging in 56 patients (Group B: 50.5%). No PPHS was observed in 24 patients (Group C: 21.6%). Adenoma volume was significantly greater for Group B than for Group A (p < 0.001). Among the Group B patients who underwent MR imaging postoperatively (n = 31), the location of PPHS was not changed, except for two patients in whom PPHS was absent. Postoperatively, PPHS was not observed in the normal location in any patient in the Group B. Conclusions: Greater volume of adenoma is associated with a higher incidence of ectopic PPHS, and the ectopic change is irreversible

  10. Simultaneous occurrence of Graves’ disease in eutopic and ectopic thyroid tissues: A case report and review of literature

    International Nuclear Information System (INIS)

    Khan, Shoukat H; Rather, Tanveer A; Syed, Tajamul

    2012-01-01

    Ectopic thyroid tissue an uncommon condition results from abnormal migration of the primitive thyroid bud. This may be the only functional thyroid. Ectopic thyroid tissue may sometimes coexist with the eutopic thyroid gland. Hyperthyroidism in association with ectopic thyroid tissue is very uncommon. We report a rare case of simultaneous involvement of ectopic and eutopic thyroid tissue in a married women of 35 years who was referred to our department for a technetium 99m thyroid scan. Coexisting ectopic and eutopic thyroid tissue due to identical histology may have similar response to various stimulatory and inhibitory factors like hormones and immunoglobulin's. Iodine-131 is an easy to administer and effective treatment for patients with simultaneous Graves’ disease in the ectopic and eutopic thyroid tissues

  11. Enhanced piezoelectricity and stretchability in energy harvesting devices fabricated from buckled PZT ribbons.

    Science.gov (United States)

    Qi, Yi; Kim, Jihoon; Nguyen, Thanh D; Lisko, Bozhena; Purohit, Prashant K; McAlpine, Michael C

    2011-03-09

    The development of a method for integrating highly efficient energy conversion materials onto soft, biocompatible substrates could yield breakthroughs in implantable or wearable energy harvesting systems. Of particular interest are devices which can conform to irregular, curved surfaces, and operate in vital environments that may involve both flexing and stretching modes. Previous studies have shown significant advances in the integration of highly efficient piezoelectric nanocrystals on flexible and bendable substrates. Yet, such inorganic nanomaterials are mechanically incompatible with the extreme elasticity of elastomeric substrates. Here, we present a novel strategy for overcoming these limitations, by generating wavy piezoelectric ribbons on silicone rubber. Our results show that the amplitudes in the waves accommodate order-of-magnitude increases in maximum tensile strain without fracture. Further, local probing of the buckled ribbons reveals an enhancement in the piezoelectric effect of up to 70%, thus representing the highest reported piezoelectric response on a stretchable medium. These results allow for the integration of energy conversion devices which operate in stretching mode via reversible deformations in the wavy/buckled ribbons.

  12. Student Evaluation of the Yellow Ribbon Suicide Prevention Program in Midwest Schools

    Science.gov (United States)

    Flynn, Alexandra; Zackula, Rosalee; Klaus, Nicole M.; McGinness, Liz; Carr, Susan; Macaluso, Matthew

    2016-01-01

    Objective Yellow Ribbon is a gatekeeper-type suicide prevention program that is widely used in public schools. However, data on its effectiveness are limited. The purpose of our study was to evaluate self-reported changes in knowledge and comfort level communicating about suicide following Yellow Ribbon training for a large, representative sample of students from a public school system in the midwestern United States. Methods The program was administered to students within the same school district during 2006 through 2009. A pre-post survey using a 4-point Likert scale was administered to rate students’ knowledge of risk factors and available resources, comfort level communicating about suicide, estimate of friends at risk for suicide, and behavioral intent toward help-seeking. Results Aggregate responses from 3,257 students, aged 11 to 18 years, were collected by the schools; 51% were female, 33% were Hispanic, and 30% were white. Suicide-related knowledge of risk factors, where to go for help, and resources, along with comfort level in asking for help, all significantly improved following program participation (Cramer’s V = 0.243 to 0.376, P suicide prevention program appears to be beneficial for students in the midwestern United States. We observed significant improvement in knowledge, comfort level, and behavioral intent for help-seeking if suicidal thoughts occur. Findings also suggested that Yellow Ribbon training administered during middle school may be especially helpful for males. PMID:27733952

  13. Third nearest neighbor parameterized tight binding model for graphene nano-ribbons

    Directory of Open Access Journals (Sweden)

    Van-Truong Tran

    2017-07-01

    Full Text Available The existing tight binding models can very well reproduce the ab initio band structure of a 2D graphene sheet. For graphene nano-ribbons (GNRs, the current sets of tight binding parameters can successfully describe the semi-conducting behavior of all armchair GNRs. However, they are still failing in reproducing accurately the slope of the bands that is directly associated with the group velocity and the effective mass of electrons. In this work, both density functional theory and tight binding calculations were performed and a new set of tight binding parameters up to the third nearest neighbors including overlap terms is introduced. The results obtained with this model offer excellent agreement with the predictions of the density functional theory in most cases of ribbon structures, even in the high-energy region. Moreover, this set can induce electron-hole asymmetry as manifested in results from density functional theory. Relevant outcomes are also achieved for armchair ribbons of various widths as well as for zigzag structures, thus opening a route for multi-scale atomistic simulation of large systems that cannot be considered using density functional theory.

  14. Plasma immersion ion implantation of boron for ribbon silicon solar cells

    Directory of Open Access Journals (Sweden)

    Derbouz K.

    2013-09-01

    Full Text Available In this work, we report for the first time on the solar cell fabrication on n-type silicon RST (for Ribbon on Sacrificial Template using plasma immersion ion implantation. The experiments were also carried out on FZ silicon as a reference. Boron was implanted at energies from 10 to 15 kV and doses from 1015 to 1016 cm-2, then activated by a thermal annealing in a conventional furnace at 900 and 950 °C for 30 min. The n+ region acting as a back surface field was achieved by phosphorus spin-coating. The frontside boron emitter was passivated either by applying a 10 nm deposited SiOX plasma-enhanced chemical vapor deposition (PECVD or with a 10 nm grown thermal oxide. The anti-reflection coating layer formed a 60 nm thick SiNX layer. We show that energies less than 15 kV and doses around 5 × 1015 cm-2 are appropriate to achieve open circuit voltage higher than 590 mV and efficiency around 16.7% on FZ-Si. The photovoltaic performances on ribbon silicon are so far limited by the bulk quality of the material and by the quality of the junction through the presence of silicon carbide precipitates at the surface. Nevertheless, we demonstrate that plasma immersion ion implantation is very promising for solar cell fabrication on ultrathin silicon wafers such as ribbons.

  15. Forming three-dimensional closed shapes from two-dimensional soft ribbons by controlled buckling

    Science.gov (United States)

    Aoki, Michio; Juang, Jia-Yang

    2018-02-01

    Conventional manufacturing techniques-moulding, machining and casting-exist to produce three-dimensional (3D) shapes. However, these industrial processes are typically geared for mass production and are not directly applicable to residential settings, where inexpensive and versatile tools are desirable. Moreover, those techniques are, in general, not adequate to process soft elastic materials. Here, we introduce a new concept of forming 3D closed hollow shapes from two-dimensional (2D) elastic ribbons by controlled buckling. We numerically and experimentally characterize how the profile and thickness of the ribbon determine its buckled shape. We find a 2D master profile with which various elliptical 3D shapes can be formed. More complex natural and artificial hollow shapes, such as strawberry, hourglass and wheel, can also be achieved via strategic design and pattern engraving on the ribbons. The nonlinear response of the post-buckling regime is rationalized through finite-element analysis, which shows good quantitative agreement with experiments. This robust fabrication should complement conventional techniques and provide a rich arena for future studies on the mechanics and new applications of elastic hollow structures.

  16. Characterisation of melt spun Ni-Ti shape memory Ribbons' microstructure

    Science.gov (United States)

    Mehrabi, Kambiz; Brunčko, Mihael; Kneissl, Albert C.; Čolič, Miodrag; Stamenković, Dragoslav; Ferčec, Janko; Anžel, Ivan; Rudolf, Rebeka

    2012-06-01

    NiTi alloys are the most technologically important medical Shape Memory Alloys in a wide range of applications used in Orthopaedics, Neurology, Cardiology and interventional Radiology as guide-wires, self-expandable stents, stent grafts, inferior vena cava filters and clinical instruments. This paper discusses the use of rapid solidification by the melt spinning method for the preparation of thin NiTi ribbons for medical uses. Generally, the application of rapid solidification via melt-spinning can change the microstructure drastically, which improves ductility and shape memory characteristics and leads to samples with small dimensions. As the increase in the wheel speed led to a reduced ribbon thickness, the cooling rate increased and, therefore, the martensitic substructure became finer. Furthermore, no transition from the crystalline phase to the amorphous phase was obtained by increasing the cooling rate, even at a wheel speed of 30 m/s. Specimens for our metallographic investigation were cut from the longitudinal cross sections of melt-spun ribbons. Conventional TEM studies were carried out with an acceleration voltage of 120 kV. Additionally, the chemical composition of the samples was examined with a TEM equipped with an EDX analyser. The crystallographic structure was determined using Bragg-Brentano x-ray diffraction with Cu-Kα radiation at room temperature.

  17. Characterizing synaptic protein development in human visual cortex enables alignment of synaptic age with rat visual cortex

    Directory of Open Access Journals (Sweden)

    Joshua G.A Pinto

    2015-02-01

    Full Text Available Although many potential neuroplasticity based therapies have been developed in the lab, few have translated into established clinical treatments for human neurologic or neuropsychiatric diseases. Animal models, especially of the visual system, have shaped our understanding of neuroplasticity by characterizing the mechanisms that promote neural changes and defining timing of the sensitive period. The lack of knowledge about development of synaptic plasticity mechanisms in human cortex, and about alignment of synaptic age between animals and humans, has limited translation of neuroplasticity therapies. In this study, we quantified expression of a set of highly conserved pre- and post-synaptic proteins (Synapsin, Synaptophysin, PSD-95, Gephyrin and found that synaptic development in human primary visual cortex continues into late childhood. Indeed, this is many years longer than suggested by neuroanatomical studies and points to a prolonged sensitive period for plasticity in human sensory cortex. In addition, during childhood we found waves of inter-individual variability that are different for the 4 proteins and include a stage during early development (<1 year when only Gephyrin has high inter-individual variability. We also found that pre- and post-synaptic protein balances develop quickly, suggesting that maturation of certain synaptic functions happens within the first year or two of life. A multidimensional analysis (principle component analysis showed that most of the variance was captured by the sum of the 4 synaptic proteins. We used that sum to compare development of human and rat visual cortex and identified a simple linear equation that provides robust alignment of synaptic age between humans and rats. Alignment of synaptic ages is important for age-appropriate targeting and effective translation of neuroplasticity therapies from the lab to the clinic.

  18. A presynaptic role for PKA in synaptic tagging and memory

    NARCIS (Netherlands)

    Park, Alan Jung; Havekes, Robbert; Choi, Jennifer H K; Luczak, Vincent; Nie, Ting; Huang, Ted; Abel, Ted

    2014-01-01

    Protein kinase A (PKA) and other signaling molecules are spatially restricted within neurons by A-kinase anchoring proteins (AKAPs). Although studies on compartmentalized PKA signaling have focused on postsynaptic mechanisms, presynaptically anchored PKA may contribute to synaptic plasticity and

  19. Memristor-based neural networks: Synaptic versus neuronal stochasticity

    KAUST Repository

    Naous, Rawan; Alshedivat, Maruan; Neftci, Emre; Cauwenberghs, Gert; Salama, Khaled N.

    2016-01-01

    In neuromorphic circuits, stochasticity in the cortex can be mapped into the synaptic or neuronal components. The hardware emulation of these stochastic neural networks are currently being extensively studied using resistive memories or memristors

  20. Neuro-inspired computing using resistive synaptic devices

    CERN Document Server

    2017-01-01

    This book summarizes the recent breakthroughs in hardware implementation of neuro-inspired computing using resistive synaptic devices. The authors describe how two-terminal solid-state resistive memories can emulate synaptic weights in a neural network. Readers will benefit from state-of-the-art summaries of resistive synaptic devices, from the individual cell characteristics to the large-scale array integration. This book also discusses peripheral neuron circuits design challenges and design strategies. Finally, the authors describe the impact of device non-ideal properties (e.g. noise, variation, yield) and their impact on the learning performance at the system-level, using a device-algorithm co-design methodology. • Provides single-source reference to recent breakthroughs in resistive synaptic devices, not only at individual cell-level, but also at integrated array-level; • Includes detailed discussion of the peripheral circuits and array architecture design of the neuro-crossbar system; • Focuses on...

  1. Learning and Memory, Part II: Molecular Mechanisms of Synaptic Plasticity

    Science.gov (United States)

    Lombroso, Paul; Ogren, Marilee

    2009-01-01

    The molecular events that are responsible for strengthening synaptic connections and how these are linked to memory and learning are discussed. The laboratory preparations that allow the investigation of these events are also described.

  2. Multistate Resistive Switching Memory for Synaptic Memory Applications

    KAUST Repository

    Hota, Mrinal Kanti; Hedhili, Mohamed N.; Wehbe, Nimer; McLachlan, Martyn A.; Alshareef, Husam N.

    2016-01-01

    memory performance is observed. Conventional synaptic operation in terms of potentiation, depression plasticity, and Ebbinghaus forgetting process are also studied. The memory mechanism is shown to originate from the migration of the oxygen vacancies

  3. Binocular Rivalry in a Competitive Neural Network with Synaptic Depression

    KAUST Repository

    Kilpatrick, Zachary P.; Bressloff, Paul C.

    2010-01-01

    We study binocular rivalry in a competitive neural network with synaptic depression. In particular, we consider two coupled hypercolums within primary visual cortex (V1), representing orientation selective cells responding to either left or right

  4. Fin Ray Stiffness and Fin Morphology Control Ribbon-Fin-Based Propulsion.

    Science.gov (United States)

    Liu, Hanlin; Taylor, Bevan; Curet, Oscar M

    2017-06-01

    Ribbon-fin-based propulsion has rich locomotor capabilities that can enhance the mobility and performance of underwater vehicles navigating in complex environments. Bony fishes using this type of propulsion send one or multiple traveling waves along an elongated fin with the actuation of highly flexible rays that are interconnected by an elastic membrane. In this work, we study how the use of flexible rays and different morphology can affect the performance of ribbon-fin propulsion. We developed a physical model composed of 15 rays that are interconnected with an elastic membrane. We tested four different ray flexural stiffness and four aspect ratios. The robotic model was tested in a low-turbulence flume under two flow conditions ([Formula: see text] wavelength/s). In two experimental sets, we measured fin kinematics, net surge forces, and power consumption. Using these data, we perform a thrust and power analysis of the undulating fin. We present the thrust coefficient, power coefficient, and propulsive efficiency. We find that the thrust generation was linear with the enclosed area swept by the fin, and square of the relative velocity between the incoming flow and traveling wave. The thrust coefficient levels off around 0.5. In addition, for our parameter range, we find that the power consumption scales by the cube of the effective tangential velocity of the rays [Formula: see text] (A is the amplitude of the ray oscillating motion, and [Formula: see text] is the angular velocity). We show that a decay in stiffness decreases both thrust production and power consumption. However, for rays with high flexural stiffness, the difference in thrust compared with rigid rays is minimal. Moreover, our results show that flexible rays can improve the propulsive efficiency compared with a rigid counterpart. Finally, we find that the morphology of ribbon fin affects its propulsive efficiency. For the aspect ratio considered in our experiments, [Formula: see text] was the most

  5. Synaptic Control of Secretory Trafficking in Dendrites

    Directory of Open Access Journals (Sweden)

    Cyril Hanus

    2014-06-01

    Full Text Available Localized signaling in neuronal dendrites requires tight spatial control of membrane composition. Upon initial synthesis, nascent secretory cargo in dendrites exits the endoplasmic reticulum (ER from local zones of ER complexity that are spatially coupled to post-ER compartments. Although newly synthesized membrane proteins can be processed locally, the mechanisms that control the spatial range of secretory cargo transport in dendritic segments are unknown. Here, we monitored the dynamics of nascent membrane proteins in dendritic post-ER compartments under regimes of low or increased neuronal activity. In response to activity blockade, post-ER carriers are highly mobile and are transported over long distances. Conversely, increasing synaptic activity dramatically restricts the spatial scale of post-ER trafficking along dendrites. This activity-induced confinement of secretory cargo requires site-specific phosphorylation of the kinesin motor KIF17 by Ca2+/calmodulin-dependent protein kinases (CaMK. Thus, the length scales of early secretory trafficking in dendrites are tuned by activity-dependent regulation of microtubule-dependent transport.

  6. Design principles of electrical synaptic plasticity.

    Science.gov (United States)

    O'Brien, John

    2017-09-08

    Essentially all animals with nervous systems utilize electrical synapses as a core element of communication. Electrical synapses, formed by gap junctions between neurons, provide rapid, bidirectional communication that accomplishes tasks distinct from and complementary to chemical synapses. These include coordination of neuron activity, suppression of voltage noise, establishment of electrical pathways that define circuits, and modulation of high order network behavior. In keeping with the omnipresent demand to alter neural network function in order to respond to environmental cues and perform tasks, electrical synapses exhibit extensive plasticity. In some networks, this plasticity can have dramatic effects that completely remodel circuits or remove the influence of certain cell types from networks. Electrical synaptic plasticity occurs on three distinct time scales, ranging from milliseconds to days, with different mechanisms accounting for each. This essay highlights principles that dictate the properties of electrical coupling within networks and the plasticity of the electrical synapses, drawing examples extensively from retinal networks. Copyright © 2017 The Author. Published by Elsevier B.V. All rights reserved.

  7. Epigenetic Basis of Neuronal and Synaptic Plasticity.

    Science.gov (United States)

    Karpova, Nina N; Sales, Amanda J; Joca, Samia R

    2017-01-01

    Neuronal network and plasticity change as a function of experience. Altered neural connectivity leads to distinct transcriptional programs of neuronal plasticity-related genes. The environmental challenges throughout life may promote long-lasting reprogramming of gene expression and the development of brain disorders. The modifications in neuronal epigenome mediate gene-environmental interactions and are required for activity-dependent regulation of neuronal differentiation, maturation and plasticity. Here, we highlight the latest advances in understanding the role of the main players of epigenetic machinery (DNA methylation and demethylation, histone modifications, chromatin-remodeling enzymes, transposons, and non-coding RNAs) in activity-dependent and long- term neural and synaptic plasticity. The review focuses on both the transcriptional and post-transcriptional regulation of gene expression levels, including the processes of promoter activation, alternative splicing, regulation of stability of gene transcripts by natural antisense RNAs, and alternative polyadenylation. Further, we discuss the epigenetic aspects of impaired neuronal plasticity and the pathogenesis of neurodevelopmental (Rett syndrome, Fragile X Syndrome, genomic imprinting disorders, schizophrenia, and others), stressrelated (mood disorders) and neurodegenerative Alzheimer's, Parkinson's and Huntington's disorders. The review also highlights the pharmacological compounds that modulate epigenetic programming of gene expression, the potential treatment strategies of discussed brain disorders, and the questions that should be addressed during the development of effective and safe approaches for the treatment of brain disorders.

  8. Cholesterol asymmetry in synaptic plasma membranes.

    Science.gov (United States)

    Wood, W Gibson; Igbavboa, Urule; Müller, Walter E; Eckert, Gunter P

    2011-03-01

    Lipids are essential for the structural and functional integrity of membranes. Membrane lipids are not randomly distributed but are localized in different domains. A common characteristic of these membrane domains is their association with cholesterol. Lipid rafts and caveolae are examples of cholesterol enriched domains, which have attracted keen interest. However, two other important cholesterol domains are the exofacial and cytofacial leaflets of the plasma membrane. The two leaflets that make up the bilayer differ in their fluidity, electrical charge, lipid distribution, and active sites of certain proteins. The synaptic plasma membrane (SPM) cytofacial leaflet contains over 85% of the total SPM cholesterol as compared with the exofacial leaflet. This asymmetric distribution of cholesterol is not fixed or immobile but can be modified by different conditions in vivo: (i) chronic ethanol consumption; (ii) statins; (iii) aging; and (iv) apoE isoform. Several potential candidates have been proposed as mechanisms involved in regulation of SPM cholesterol asymmetry: apoE, low-density lipoprotein receptor, sterol carrier protein-2, fatty acid binding proteins, polyunsaturated fatty acids, P-glycoprotein and caveolin-1. This review examines cholesterol asymmetry in SPM, potential mechanisms of regulation and impact on membrane structure and function. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

  9. Ectopic cystoperitoneal shunt demonstrated by valvulography. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Jofre, M J; Sierralta, M P [Military Hospital Nuclear Medicine Department, Santiago (Chile)

    2002-09-01

    and the cough disappeared. Valvulography is a simple easily interpreted technique for the investigation of shunt complications, because of non-specific symptoms and signs that are not always recognized. It is important to consider the migration of the distal catheter resulting in ectopic localizations.

  10. Ectopic cystoperitoneal shunt demonstrated by valvulography. A case report

    International Nuclear Information System (INIS)

    Jofre, M.J.; Sierralta, M.P.

    2002-01-01

    and the cough disappeared. Valvulography is a simple easily interpreted technique for the investigation of shunt complications, because of non-specific symptoms and signs that are not always recognized. It is important to consider the migration of the distal catheter resulting in ectopic localizations

  11. Interventional radiology and endovascular surgery in the treatment of ectopic pregnancies

    Energy Technology Data Exchange (ETDEWEB)

    Fornazari, Vinicius Adami Vayego; Szejnfeld, Denis; Elito, Julio Júnior; Goldman, Suzan Menasce [Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2015-07-01

    The advent of interventional radiology enabled remarkable advances in diagnosis and treatment of several situations in obstetrics and gynecology. In the field of obstetrics, these advances include temporary occlusion of the iliac arteries to the management of placenta accreta and/or prior, arteriovenous fistulas after embolization of uterine curettage and management of ectopic uterine and extra-uterine pregnancies. The non-tubal ectopic pregnancy, either cervical, abdominal, ovarian or in a cesarean scar, often represents major therapeutic challenge, especially when exists a desire to maintain fertility. Despite the systemic methotrexate therapy and surgical resection of the ectopic gestational sac be the most used therapeutic options, the interventionist approach of non-tubal ectopic pregnancies, direct injection of methotrexate in the gestational sac and intra-arterial chemoembolization of uterine arteries constitute in the currently literature viable, safe, effective modalities with low morbidity, shorter hospital stay, and rapid clinical recovery. Because of little variety of materials used, and the increase in training of specialists in the area, the radiological intervention as a treatment option in ectopic pregnancies is financially viable and present considerable accessibility in the world and at most of Brazilian medical centers.

  12. Morphological, diagnostic and surgical features of ectopic thyroid gland: a review of literature.

    Science.gov (United States)

    Guerra, Germano; Cinelli, Mariapia; Mesolella, Massimo; Tafuri, Domenico; Rocca, Aldo; Amato, Bruno; Rengo, Sandro; Testa, Domenico

    2014-01-01

    Ectopic thyroid tissue remains a rare developmental abnormality involving defective or aberrant embryogenesis of the thyroid gland during its passage from the floor of the primitive foregut to its usual final position in pre-tracheal region of the neck. Its specific prevalence accounts about 1 case per 100.000-300.000 persons and one in 4.000-8.000 patients with thyroid disease show this condition. The cause of this defect is not fully known. Despite genetic factors have been associated with thyroid gland morphogenesis and differentiation, just recently some mutation has been associated with human thyroid ectopy. Lingual region in the most common site of thyroid ectopy but ectopic thyroid tissue were found in other head and neck locations. Nevertheless, aberrant ectopic thyroid tissue has been found in other places distant from the neck region. Ectopic tissue is affected by different pathological changes that occur in the normal eutopic thyroid. Patients may present insidiously or as an emergency. Diagnostic management of thyroid ectopy is performed by radionuclide thyroid imaging, ultrasonography, CT scan, MRI, biopsy and thyroid function tests. Asymptomatic euthyroid patients with ectopic thyroid do not usually require therapy but are kept under observation. For those with symptoms, treatment depends on size of the gland, nature of symptoms, thyroid function status and histological findings. Surgical excision is often required as treatment for this condition. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  13. Failure Rate of Single Dose Methotrexate in Managment of Ectopic Pregnancy

    Directory of Open Access Journals (Sweden)

    Feras Sendy

    2015-01-01

    Full Text Available Background. One of the treatment modalities for ectopic pregnancy is methotrexate. The purpose of this study is to identify the failure rate of methotrexate in treating patients with ectopic pregnancy as well as the risk factors leading to treatment failure. Methods. A retrospective chart review of 225 patients who received methotrexate as a primary management option for ectopic pregnancy. Failure of single dose of methotrexate was defined as drop of BHCG level less than or equal to 14% in the seventh day after administration of methotrexate. Results. 225 patients had methotrexate. Most of the patients (151 (67% received methotrexate based on the following formula: f 50 mg X body surface area. Single dose of methotrexate was successful in 72% (162/225 of the patients. 28% (63/225 were labeled as failure of single dose of methotrexate because of suboptimal drop in BhCG. 63% (40/63 of failure received a second dose of methotrexate, and 37% (23/63 underwent surgical treatment. Among patient who received initial dose of methotrexate, 71% had moderate or severe pain, and 58% had ectopic mass size of more than 4 cm on ultrasound. Conclusion. Liberal use of medical treatment of ectopic pregnancy results in 71% success rate.

  14. Failure rate of single dose methotrexate in managment of ectopic pregnancy.

    Science.gov (United States)

    Sendy, Feras; AlShehri, Eman; AlAjmi, Amani; Bamanie, Elham; Appani, Surekha; Shams, Taghreed

    2015-01-01

    Background. One of the treatment modalities for ectopic pregnancy is methotrexate. The purpose of this study is to identify the failure rate of methotrexate in treating patients with ectopic pregnancy as well as the risk factors leading to treatment failure. Methods. A retrospective chart review of 225 patients who received methotrexate as a primary management option for ectopic pregnancy. Failure of single dose of methotrexate was defined as drop of BHCG level less than or equal to 14% in the seventh day after administration of methotrexate. Results. 225 patients had methotrexate. Most of the patients (151 (67%)) received methotrexate based on the following formula: f 50 mg X body surface area. Single dose of methotrexate was successful in 72% (162/225) of the patients. 28% (63/225) were labeled as failure of single dose of methotrexate because of suboptimal drop in BhCG. 63% (40/63) of failure received a second dose of methotrexate, and 37% (23/63) underwent surgical treatment. Among patient who received initial dose of methotrexate, 71% had moderate or severe pain, and 58% had ectopic mass size of more than 4 cm on ultrasound. Conclusion. Liberal use of medical treatment of ectopic pregnancy results in 71% success rate.

  15. Ectopic Molar Pregnancy: Diagnostic Efficacy of Magnetic Resonance Imaging and Review of the Literature.

    Science.gov (United States)

    Yamada, Yasushi; Ohira, Satoshi; Yamazaki, Teruyuki; Shiozawa, Tanri

    2016-01-01

    Ectopic molar pregnancy is extremely rare, and preoperative diagnosis is difficult. Our literature search found only one report of molar pregnancy diagnosed preoperatively. Moreover, there is no English literature depicting magnetic resonance image (MRI) findings of ectopic molar pregnancy. We report a case of ectopic molar pregnancy preoperatively diagnosed using MRI. A literature review of 31 cases of ectopic molar pregnancy demonstrated that lesions have been found in the fallopian tube (19 cases, 61%), ovary (5 cases, 16%), cornu (3 cases, 10%), peritoneum (2 cases, 6%), uterine cervix (1 case, 3%), and cesarean scar (1 case, 3%). Abdominal pain and abnormal vaginal bleeding were reported in 70% and 61% of the patients, respectively. Twenty-one cases (67%) presented with rupture and hemoperitoneum. All patients underwent surgical resection or dilatation and curettage. Methotrexate therapy was performed in one case because residual trophoblastic tissue was suspected. A second operation was performed in one case of ovarian molar pregnancy because serum hCG levels increased again after primary focal ovarian resection. No patients developed metastatic disease or relapsed. These findings suggest the prognosis of ectopic molar pregnancy to be favorable.

  16. Ectopic Molar Pregnancy: Diagnostic Efficacy of Magnetic Resonance Imaging and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Yasushi Yamada

    2016-01-01

    Full Text Available Ectopic molar pregnancy is extremely rare, and preoperative diagnosis is difficult. Our literature search found only one report of molar pregnancy diagnosed preoperatively. Moreover, there is no English literature depicting magnetic resonance image (MRI findings of ectopic molar pregnancy. We report a case of ectopic molar pregnancy preoperatively diagnosed using MRI. A literature review of 31 cases of ectopic molar pregnancy demonstrated that lesions have been found in the fallopian tube (19 cases, 61%, ovary (5 cases, 16%, cornu (3 cases, 10%, peritoneum (2 cases, 6%, uterine cervix (1 case, 3%, and cesarean scar (1 case, 3%. Abdominal pain and abnormal vaginal bleeding were reported in 70% and 61% of the patients, respectively. Twenty-one cases (67% presented with rupture and hemoperitoneum. All patients underwent surgical resection or dilatation and curettage. Methotrexate therapy was performed in one case because residual trophoblastic tissue was suspected. A second operation was performed in one case of ovarian molar pregnancy because serum hCG levels increased again after primary focal ovarian resection. No patients developed metastatic disease or relapsed. These findings suggest the prognosis of ectopic molar pregnancy to be favorable.

  17. Upper gastrointestinal ectopic variceal bleeding treated with various endoscopic modalities: Case reports and literature review.

    Science.gov (United States)

    Park, Sang Woo; Cho, Eunae; Jun, Chung Hwan; Choi, Sung Kyu; Kim, Hyun Soo; Park, Chang Hwan; Rew, Jong Sun; Cho, Sung Bum; Kim, Hee Joon; Han, Mingui; Cho, Kyu Man

    2017-01-01

    Ectopic variceal bleeding is a rare (2-5%) but fatal gastrointestinal bleed in patients with portal hypertension. Patients with ectopic variceal bleeding manifest melena, hematochezia, or hematemesis, which require urgent managements. Definitive therapeutic modalities of ectopic varices are not yet standardized because of low incidence. Various therapeutic modalities have been applied on the basis of the experiences of experts or availability of facilities, with varying results. We have encountered eight cases of gastrointestinal ectopic variceal bleeding in five patients in the last five years. All patients were diagnosed with liver cirrhosis presenting melena or hematemesis. All patients were treated with various endoscopic modalities (endoscopic variceal obturation [EVO] with cyanoacrylate in five cases, endoscopic variceal band ligation (EVL) in two cases, hemoclipping in one case). Satisfactory hemostasis was achieved without radiologic interventions in all cases. EVO and EVL each caused one case of portal biliopathy, and EVL induced ulcer bleeding in one case. EVO generally accomplished better results of variceal obturations than EVL or hemoclipping, without serious adverse events. EVO may be an effective modality for control of ectopic variceal bleeding without radiologic intervention or surgery.

  18. Reduced Synaptic Vesicle Recycling during Hypoxia in Cultured Cortical Neurons

    OpenAIRE

    Fedorovich, Sergei; Hofmeijer, Jeannette; van Putten, Michel Johannes Antonius Maria; le Feber, Jakob

    2017-01-01

    Improvement of neuronal recovery in the ischemic penumbra, an area around the core of a brain infarct with some remaining perfusion, has a large potential for the development of therapy against acute ischemic stroke. However, mechanisms that lead to either recovery or secondary damage in the penumbra largely remain unclear. Recent studies in cultured networks of cortical neurons showed that failure of synaptic transmission (referred to as synaptic failure) is a critical factor in the penumbra...

  19. Common mechanisms of synaptic plasticity in vertebrates and invertebrates

    Science.gov (United States)

    Glanzman, David L.

    2016-01-01

    Until recently, the literature on learning-related synaptic plasticity in invertebrates has been dominated by models assuming plasticity is mediated by presynaptic changes, whereas the vertebrate literature has been dominated by models assuming it is mediated by postsynaptic changes. Here I will argue that this situation does not reflect a biological reality and that, in fact, invertebrate and vertebrate nervous systems share a common set of mechanisms of synaptic plasticity. PMID:20152143

  20. Synaptic Contacts Enhance Cell-to-Cell Tau Pathology Propagation.

    Science.gov (United States)

    Calafate, Sara; Buist, Arjan; Miskiewicz, Katarzyna; Vijayan, Vinoy; Daneels, Guy; de Strooper, Bart; de Wit, Joris; Verstreken, Patrik; Moechars, Diederik

    2015-05-26

    Accumulation of insoluble Tau protein aggregates and stereotypical propagation of Tau pathology through the brain are common hallmarks of tauopathies, including Alzheimer's disease (AD). Propagation of Tau pathology appears to occur along connected neurons, but whether synaptic contacts between neurons are facilitating propagation has not been demonstrated. Using quantitative in vitro models, we demonstrate that, in parallel to non-synaptic mechanisms, synapses, but not merely the close distance between the cells, enhance the propagation of Tau pathology between acceptor hippocampal neurons and Tau donor cells. Similarly, in an artificial neuronal network using microfluidic devices, synapses and synaptic activity are promoting neuronal Tau pathology propagation in parallel to the non-synaptic mechanisms. Our work indicates that the physical presence of synaptic contacts between neurons facilitate Tau pathology propagation. These findings can have implications for synaptic repair therapies, which may turn out to have adverse effects by promoting propagation of Tau pathology. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  1. BDNF-induced local protein synthesis and synaptic plasticity.

    Science.gov (United States)

    Leal, Graciano; Comprido, Diogo; Duarte, Carlos B

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) is an important regulator of synaptic transmission and long-term potentiation (LTP) in the hippocampus and in other brain regions, playing a role in the formation of certain forms of memory. The effects of BDNF in LTP are mediated by TrkB (tropomyosin-related kinase B) receptors, which are known to be coupled to the activation of the Ras/ERK, phosphatidylinositol 3-kinase/Akt and phospholipase C-γ (PLC-γ) pathways. The role of BDNF in LTP is best studied in the hippocampus, where the neurotrophin acts at pre- and post-synaptic levels. Recent studies have shown that BDNF regulates the transport of mRNAs along dendrites and their translation at the synapse, by modulating the initiation and elongation phases of protein synthesis, and by acting on specific miRNAs. Furthermore, the effect of BDNF on transcription regulation may further contribute to long-term changes in the synaptic proteome. In this review we discuss the recent progress in understanding the mechanisms contributing to the short- and long-term regulation of the synaptic proteome by BDNF, and the role in synaptic plasticity, which is likely to influence learning and memory formation. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Self-organised criticality via retro-synaptic signals

    Science.gov (United States)

    Hernandez-Urbina, Victor; Herrmann, J. Michael

    2016-12-01

    The brain is a complex system par excellence. In the last decade the observation of neuronal avalanches in neocortical circuits suggested the presence of self-organised criticality in brain networks. The occurrence of this type of dynamics implies several benefits to neural computation. However, the mechanisms that give rise to critical behaviour in these systems, and how they interact with other neuronal processes such as synaptic plasticity are not fully understood. In this paper, we present a long-term plasticity rule based on retro-synaptic signals that allows the system to reach a critical state in which clusters of activity are distributed as a power-law, among other observables. Our synaptic plasticity rule coexists with other synaptic mechanisms such as spike-timing-dependent plasticity, which implies that the resulting synaptic modulation captures not only the temporal correlations between spiking times of pre- and post-synaptic units, which has been suggested as requirement for learning and memory in neural systems, but also drives the system to a state of optimal neural information processing.

  3. SYNAPTIC DEPRESSION IN DEEP NEURAL NETWORKS FOR SPEECH PROCESSING.

    Science.gov (United States)

    Zhang, Wenhao; Li, Hanyu; Yang, Minda; Mesgarani, Nima

    2016-03-01

    A characteristic property of biological neurons is their ability to dynamically change the synaptic efficacy in response to variable input conditions. This mechanism, known as synaptic depression, significantly contributes to the formation of normalized representation of speech features. Synaptic depression also contributes to the robust performance of biological systems. In this paper, we describe how synaptic depression can be modeled and incorporated into deep neural network architectures to improve their generalization ability. We observed that when synaptic depression is added to the hidden layers of a neural network, it reduces the effect of changing background activity in the node activations. In addition, we show that when synaptic depression is included in a deep neural network trained for phoneme classification, the performance of the network improves under noisy conditions not included in the training phase. Our results suggest that more complete neuron models may further reduce the gap between the biological performance and artificial computing, resulting in networks that better generalize to novel signal conditions.

  4. Mislocalization of the Drosophila centromere-specific histone CIDpromotes formation of functional ectopic kinetochores

    Energy Technology Data Exchange (ETDEWEB)

    Heun, Patrick; Erhardt, Sylvia; Blower, Michael D.; Weiss,Samara; Skora, Andrew D.; Karpen, Gary H.

    2006-01-30

    The centromere-specific histone variant CENP-A (CID in Drosophila) is a structural and functional foundation for kinetochore formation and chromosome segregation. Here, we show that overexpressed CID is mislocalized into normally non-centromeric regions in Drosophila tissue culture cells and animals. Analysis of mitoses in living and fixed cells reveals that mitotic delays, anaphase bridges, chromosome fragmentation, and cell and organismal lethality are all direct consequences of CID mislocalization. In addition, proteins that are normally restricted to endogenous kinetochores assemble at a subset of ectopic CID incorporation regions. The presence of microtubule motors and binding proteins, spindle attachments, and aberrant chromosome morphologies demonstrate that these ectopic kinetochores are functional. We conclude that CID mislocalization promotes formation of ectopic centromeres and multicentric chromosomes, which causes chromosome missegregation, aneuploidy, and growth defects. Thus, CENP-A mislocalization is one possible mechanism for genome instability during cancer progression, as well as centromere plasticity during evolution.

  5. Ectopic pregnancy: pictorial essay focusing on computed tomography and magnetic resonance imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Febronio, Eduardo Miguel; Rosas, George de Queiroz; D' Ippolito, Giuseppe [Escola Paulista de Medicina - Universidade Federal de Sao Paulo (EPM-Unifesp), Sao Paulo, SP (Brazil). Dept. of Imaging Diagnosis; Cardia, Patricia Prando, E-mail: giuseppe_dr@uol.com.br [Centro Radiologico Campinas, Campinas, SP (Brazil)

    2012-09-15

    The objective of the present study is to describe key computed tomography and magnetic resonance imaging findings in patients with acute abdominal pain caused by ectopic pregnancy. For this purpose, two radiologists consensually selected and analyzed computed tomography and magnetic resonance imaging studies performed in female patients with acute abdominal pain caused by proven ectopic pregnancy in the period between January 2010 and December 2011. The imaging diagnosis of ectopic pregnancy is usually obtained by ultrasonography, however, with the increasing use of computed tomography and magnetic resonance imaging in the assessment of patients with acute abdomen of gynecological origin it is necessary that the radiologist becomes familiar with the main findings observed at these diagnostic methods. (author)

  6. Ectopic pregnancy: pictorial essay focusing on computed tomography and magnetic resonance imaging findings

    International Nuclear Information System (INIS)

    Febronio, Eduardo Miguel; Rosas, George de Queiroz; D'Ippolito, Giuseppe

    2012-01-01

    The objective of the present study is to describe key computed tomography and magnetic resonance imaging findings in patients with acute abdominal pain caused by ectopic pregnancy. For this purpose, two radiologists consensually selected and analyzed computed tomography and magnetic resonance imaging studies performed in female patients with acute abdominal pain caused by proven ectopic pregnancy in the period between January 2010 and December 2011. The imaging diagnosis of ectopic pregnancy is usually obtained by ultrasonography, however, with the increasing use of computed tomography and magnetic resonance imaging in the assessment of patients with acute abdomen of gynecological origin it is necessary that the radiologist becomes familiar with the main findings observed at these diagnostic methods. (author)

  7. High Titers of Chlamydia trachomatis Antibodies in Brazilian Women with Tubal Occlusion or Previous Ectopic Pregnancy

    Directory of Open Access Journals (Sweden)

    A. C. S. Machado

    2007-01-01

    Full Text Available Objective. To evaluate serum chlamydia antibody titers (CATs in tubal occlusion or previous ectopic pregnancy and the associated risk factors. Methods. The study population consisted of 55 women wih tubal damage and 55 parous women. CAT was measured using the whole-cell inclusion immunofluorescence test and cervical chlamydial DNA detected by PCR. Odds ratios were calculated to assess variables associated with C. trachomatis infection. Results. The prevalence of chlamydial antibodies and antibody titers in women with tubal occlusion or previous ectopic pregnancy was significantly higher (P<.01 than in parous women. Stepwise logistic regression analysis showed that chlamydia IgG antibodies were associated with tubal damage and with a larger number of lifetime sexual partners. Conclusions. Chlamydia antibody titers were associated with tubal occlusion, prior ectopic pregnancy, and with sexual behavior, suggesting that a chlamydia infection was the major contributor to the tubal damage in these women.

  8. Neuroendocrine carcinoma of the ampulla of Vater causing ectopic adrenocorticotropic hormone-dependent Cushing's syndrome.

    Science.gov (United States)

    Kato, Akihisa; Hayashi, Kazuki; Naitoh, Itaru; Seno, Kyoji; Okada, Yukiko; Ban, Tesshin; Kondo, Hiromu; Nishi, Yuji; Umemura, Shuichiro; Hori, Yasuki; Natsume, Makoto; Joh, Takashi

    2016-07-01

    Ectopic adrenocorticotropic hormone (ACTH) is rarely secreted by neuroendocrine tumors. Although neuroendocrine tumors may occur at any site in the gastrointestinal system, they very rarely occur in the ampulla of Vater and have a poor prognosis. The present study described the first Cushing's syndrome as a result of ectopic ACTH arising from the ampulla of Vater neuroendocrine carcinoma. A 69-year-old female was admitted with clinical features of Cushing's syndrome, confirmed biochemically by hypokalemia, and elevated levels of ACTH and cortisol. In further investigations, a tumor of the ampulla of Vater and liver metastases were detected. Pathological analysis of the biopsy confirmed a neuroendocrine carcinoma, which was immunohistochemically positive for chromogranin A, synaptophysin, cluster of differentiation 56 and ACTH. Therefore, the present study diagnosed a functional and metastatic neuroendocrine carcinoma of the ampulla of Vater with ectopic ACTH production causing Cushing's syndrome. The patient succumbed to mortality 4 months later, despite administration of combined chemotherapy with irinotecan and cisplatin.

  9. A Case of Hemorrhagic Necrosis of Ectopic Liver Tissue within the Gallbladder Wall.

    LENUS (Irish Health Repository)

    Nagar, Sapna

    2012-02-01

    Ectopic liver tissue is a rare clinical entity that is mostly asymptomatic and found incidentally. In certain situations, however, patients may present with symptoms of abdominal pain secondary to torsion, compression, obstruction of adjacent organs, or rupture secondary to malignant transformation. Herein, we report a case of a 25-year-old female that presented with acute onset of epigastric pain found to have ectopic liver tissue near the gallbladder complicated by acute hemorrhage necessitating operative intervention in the way of laparoscopic excision and cholecystectomy. The patient\\'s postoperative course was uneventful. Gross pathology demonstrated a 1.2 x 2.8 x 4.5 cm firm purple ovoid structure that histologically revealed extensive hemorrhagic necrosis of benign ectopic liver tissue.

  10. Radiographic assessment of dental anomalies in patients with ectopic maxillary canines

    DEFF Research Database (Denmark)

    Sørensen, Helle Budtz; Artmann, Lone; Larsen, Helle Juul

    2008-01-01

    dental deviations in cases with either palatal or labial ectopic canines. Design. Panoramic and intra-oral radiographs from 50 patients with palatally located (38 females and 12 males) and 19 patients with labially located ectopic canines (11 females and 8 males), aged 10 years, 2 months-18 years, 1...... month, were analysed. Dental deviations registered were crown and root malformations, agenesis, and eruption deviations. Registrations were performed in the maxillary incisor field and in the dentition in general. Results. The study documented that palatally as well as labially located ectopic canines...... can occur in dentitions without other dental deviations. Dental deviations occurred in approximately two-thirds of all cases, more often in females and in cases with palatally located canines. More than half of the females with palatally located canines had deviations in the maxillary incisors...

  11. Value of intramuscular methotrexate and bilateral uterine artery embolization for treating cervical ectopic pregnancy

    International Nuclear Information System (INIS)

    Pan Feng; Xiong Bin

    2011-01-01

    Objective: To assess the clinical value of bilateral uterine artery chemotherapy embolization (UACE) for cervical ectopic pregnancy analyzed. Methods: Clinical records of 40 patients with cervical ectopic pregnancy treated using UACE were retrospectively analyzed. Results: 8 patients with severe active vaginal bleeding after curettage were treated urgently with UACE. The remaining 32 patients were treated with UACE combined with sequential ultrasound-guided curettage. Active vaginal bleeding was stopped after UACE. There was no recurrent hemorrhage with the sequential ultrasound-guided curettage procedure. The β-HCG levels of all patients were normalized after 1 month. Conclusion: Bilateral uterine artery chemotherapy embolization is valuable as emergency treatment for patients with severe vaginal bleeding from cervical ectopic pregnancy. UACE combined with sequential ultrasound-guided curettage may be more effective. (authors)

  12. Acromegaly with no pituitary adenoma and no evidence of ectopic source

    Directory of Open Access Journals (Sweden)

    Deepak Khandelwal

    2011-01-01

    Full Text Available More than 99% of patients with acromegaly harbor a growth hormone (GH secreting pituitary adenoma. As the time from onset of signs/symptoms to diagnosis of acromegaly is long (symptom onset to diagnosis is often 4-10 years, pituitary adenomas that cause GH excess are often large and are nearly always visible on conventional magnetic resonance imaging (MRI. However, in rare circumstances, acromegalic patients without an ectopic source will not have imaging evidence of a pituitary adenoma. Management of these patients poses special challenge, and once ectopic source of GH/growth-hormone-releasing hormone (GHRH is ruled out, an exploration of pituitary might be useful. We herein report a case of acromegaly with imaging evidence of sellar floor osteoma, but no pituitary adenoma, and negative work up for an ectopic source of GH/GHRH tumor, and on surgical exploration pituitary adenoma could be identified and removed and confirmed on histopathologic examination.

  13. Synaptic dimorphism in Onychophoran cephalic ganglia

    Directory of Open Access Journals (Sweden)

    Z Peña-Contreras

    2007-03-01

    Full Text Available The taxonomic location of the Onychophora has been controversial because of their phenotypic and genotypic characteristics, related to both annelids and arthropods. We analyzed the ultrastructure of the neurons and their synapses in the cephalic ganglion of a poorly known invertebrate, the velvet worm Peripatus sedgwicki, from the mountainous region of El Valle, Mérida, Venezuela. Cephalic ganglia were dissected, fixed and processed for transmission electron microscopy. The animal has a high degree of neurobiological development, as evidenced by the presence of asymmetric (excitatory and symmetric (inhibitory synapses, as well as the existence of glial cell processes in a wide neuropile zone. The postsynaptic terminals were seen to contain subsynaptic cisterns formed by membranes of smooth endoplasmic reticulum beneath the postsynaptic density, whereas the presynaptic terminal showed numerous electron transparent synaptic vesicles. From the neurophylogenetic perspectives, the ultrastructural characteristics of the central nervous tissue of the Onychophora show important evolutionary acquirements, such as the presence of both excitatory and inhibitory synapses, indicating functional synaptic transmission, and the appearance of mature glial cells. Rev. Biol . Trop. 55 (1: 261-267. Epub 2007 March. 31.Estudiamos la ultraestructura de las neuronas y sus sinapsis del ganglio cefálico de un invertebrado poco conocido del phylum Onychophora: Peripatus sedgwicki de los Andes Venezolanos, utilizando para ello la microscopía electrónica de transmisión. La localización taxonómica de los onicóforos ha sido controversial debido a sus características fenotípicas y genotípicas que los relacionan tanto con los anélidos como con los artrópodos. Para este trabajo se estudió el ganglio cefálico de P. sedgwicki de la zona montañosa de El Valle, Mérida, Venezuela. El ganglio cefálico se localiza en la región anterior del animal y fue diseccionado

  14. Characterizing synaptic protein development in human visual cortex enables alignment of synaptic age with rat visual cortex

    Science.gov (United States)

    Pinto, Joshua G. A.; Jones, David G.; Williams, C. Kate; Murphy, Kathryn M.

    2015-01-01

    Although many potential neuroplasticity based therapies have been developed in the lab, few have translated into established clinical treatments for human neurologic or neuropsychiatric diseases. Animal models, especially of the visual system, have shaped our understanding of neuroplasticity by characterizing the mechanisms that promote neural changes and defining timing of the sensitive period. The lack of knowledge about development of synaptic plasticity mechanisms in human cortex, and about alignment of synaptic age between animals and humans, has limited translation of neuroplasticity therapies. In this study, we quantified expression of a set of highly conserved pre- and post-synaptic proteins (Synapsin, Synaptophysin, PSD-95, Gephyrin) and found that synaptic development in human primary visual cortex (V1) continues into late childhood. Indeed, this is many years longer than suggested by neuroanatomical studies and points to a prolonged sensitive period for plasticity in human sensory cortex. In addition, during childhood we found waves of inter-individual variability that are different for the four proteins and include a stage during early development (visual cortex and identified a simple linear equation that provides robust alignment of synaptic age between humans and rats. Alignment of synaptic ages is important for age-appropriate targeting and effective translation of neuroplasticity therapies from the lab to the clinic. PMID:25729353

  15. Identification of synaptic targets of Drosophila pumilio.

    Directory of Open Access Journals (Sweden)

    Gengxin Chen

    2008-02-01

    Full Text Available Drosophila Pumilio (Pum protein is a translational regulator involved in embryonic patterning and germline development. Recent findings demonstrate that Pum also plays an important role in the nervous system, both at the neuromuscular junction (NMJ and in long-term memory formation. In neurons, Pum appears to play a role in homeostatic control of excitability via down regulation of para, a voltage gated sodium channel, and may more generally modulate local protein synthesis in neurons via translational repression of eIF-4E. Aside from these, the biologically relevant targets of Pum in the nervous system remain largely unknown. We hypothesized that Pum might play a role in regulating the local translation underlying synapse-specific modifications during memory formation. To identify relevant translational targets, we used an informatics approach to predict Pum targets among mRNAs whose products have synaptic localization. We then used both in vitro binding and two in vivo assays to functionally confirm the fidelity of this informatics screening method. We find that Pum strongly and specifically binds to RNA sequences in the 3'UTR of four of the predicted target genes, demonstrating the validity of our method. We then demonstrate that one of these predicted target sequences, in the 3'UTR of discs large (dlg1, the Drosophila PSD95 ortholog, can functionally substitute for a canonical NRE (Nanos response element in vivo in a heterologous functional assay. Finally, we show that the endogenous dlg1 mRNA can be regulated by Pumilio in a neuronal context, the adult mushroom bodies (MB, which is an anatomical site of memory storage.

  16. Ectopic Varices in the Gastrointestinal Tract: Short- and Long-Term Outcomes of Percutaneous Therapy

    International Nuclear Information System (INIS)

    Macedo, Thanila A.; Andrews, James C.; Kamath, Patrick S.

    2005-01-01

    To evaluate the results of percutaneous management of ectopic varices, a retrospective review was carried out of 14 patients (9 men, 5 women; mean age 58 years) who between 1992 and 2001 underwent interventional radiological techniques for management of bleeding ectopic varices. A history of prior abdominal surgery was present in 12 of 14 patients. The interval between the surgery and percutaneous intervention ranged from 2 to 38 years. Transhepatic portal venography confirmed ectopic varices to be the source of portal hypertension-related gastrointestinal bleeding. Embolization of the ectopic varices was performed by a transhepatic approach with coil embolization of the veins draining into the ectopic varices. Transjugular intrahepatic portosystemic shunt (TIPS) was performed in the standard fashion. Eighteen procedures (12 primary coil embolizations, 1 primary TIPS, 2 re-embolizations, 3 secondary TIPS) were performed in 13 patients. One patient was not a candidate for percutaneous treatment. All interventions but one (re-embolization) were technically successful. In 2 of 18 interventions, re-bleeding occurred within 72 hr (both embolization patients). Recurrent bleeding (23 days to 27 months after initial intervention) was identified in 9 procedures (8 coil embolizations, 1 TIPS due to biliary fistula). One patient had TIPS revision because of ultrasound surveillance findings. New encephalopathy developed in 2 of 4 TIPS patients. Percutaneous coil embolization is a simple and safe treatment for bleeding ectopic varices; however, recurrent bleeding is frequent and reintervention often required. TIPS can offer good control of bleeding at the expense of a more complex procedure and associated risk of encephalopathy

  17. Ectopic Cushing' syndrome caused by a neuroendocrine carcinoma of the mesentery

    Directory of Open Access Journals (Sweden)

    Petersenn Stephan

    2006-04-01

    Full Text Available Abstract Background ACTH overproduction within the pituitary gland or ectopically leads to hypercortisolism. Here, we report the first case of Cushing' syndrome caused by an ectopic ACTH-secreting neuroendocrine carcinoma of the mesentery. Moreover, diagnostic procedures and pitfalls associated with ectopic ACTH-secreting tumors are demonstrated and discussed. Case presentation A 41 year-old man presented with clinical features and biochemical tests suggestive of ectopic Cushing's syndrome. First, subtotal thyroidectomy was performed without remission of hypercortisolism, because an octreotide scan showed increased activity in the left thyroid gland and an ultrasound revealed nodules in both thyroid lobes one of which was autonomous. In addition, the patient had a 3 mm hypoenhancing lesion of the neurohypophysis and a 1 cm large adrenal tumor. Surgical removal of the pituitary lesion within the posterior lobe did not improve hypercortisolism and we continued to treat the patient with metyrapone to block cortisol production. At 18-months follow-up from initial presentation, we detected an ACTH-producing neuroendocrine carcinoma of the mesentery by using a combination of octreotide scan, computed tomography scan, and positron emission tomography. Intraoperatively, use of a gamma probe after administration of radiolabeled 111In-pentetreotide helped identify the mesenteric neuroendocrine tumor. After removal of this carcinoma, the patient improved clinically. Laboratory testing confirmed remission of hypercortisolism. An octreotide scan 7 months after surgery showed normal results. Conclusion This case underscores the diagnostic challenge in identifying an ectopic ACTH-producing tumor and the pluripotency of cells, in this case of mesenteric cells that can start producing and secreting ACTH. It thereby helps elucidate the pathogenesis of neuroendocrine tumors. This case also suggests that patients with ectopic Cushing's syndrome and an octreotide

  18. Efficacy of dexmedetomidine for the control of junctional ectopic tachycardia after repair of tetralogy of Fallot

    Directory of Open Access Journals (Sweden)

    Randhir S Rajput

    2014-01-01

    Full Text Available Background: Junctional ectopic tachycardia occurs frequently after congenital cardiac surgery and can be a cause of increased morbidity and mortality. Dexmedetomidine (DEX is an a2 adrenoreceptor agonist, has properties of controlling tachyarrhythmia by regulating the sympatho-adrenal system. Objective: To evaluate the efficacy of DEX for control of junctional ectopic tachycardia after repair of Tetralogy of Fallot (TOF. Materials and Methods: Two hundred and twenty pediatric cardiac patients with TOFs were enrolled in a prospective randomized control study. Patients underwent correction surgery. They were divided into two groups, i.e., Group 1 (DEX and Group 2 (control. Heart rate, rhythm, mean arterial pressure (MAP were recorded after the anesthetic induction (T1, after termination of bypass (T2, after 04 hours (T3, and 08 hours after transferring the patient to intensive care unit (ICU; T4. Results: Heart rate was comparable between two groups before starting the drug but statistically significant after bypass until 08 hours after transferring the patient to ICU. Junctional ectopic tachycardia occurred more in Group-2 (20% as compared to Group-1 (9.09%; P = 0.022. Junctional ectopic tachycardia occurs early in Group-2 (0.14 ± 0.527 hours as compared to Group 1 (0.31 ± 1.29 hours; P = 0.042. The duration of junctional ectopic tachycardia was more prolonged in Group-2 (1.63 ± 3.64 hours as compared to Group-1 (0.382 ± 1.60 hours; P = 0.012. The time to withdraw from mechanical ventilation and ICU stay of Group 1 patient was less than of Group 2 patients (P = <0.001. Conclusion: DEX had a therapeutic role in the prevention of junctional ectopic tachycardia in patients undergoing repair for TOF.

  19. Ectopic Cushing' syndrome caused by a neuroendocrine carcinoma of the mesentery

    International Nuclear Information System (INIS)

    Fasshauer, Mathias; Paschke, Ralf; Koch, Christian A; Lincke, Thomas; Witzigmann, Helmut; Kluge, Regine; Tannapfel, Andrea; Moche, Michael; Buchfelder, Michael; Petersenn, Stephan; Kratzsch, Juergen

    2006-01-01

    ACTH overproduction within the pituitary gland or ectopically leads to hypercortisolism. Here, we report the first case of Cushing' syndrome caused by an ectopic ACTH-secreting neuroendocrine carcinoma of the mesentery. Moreover, diagnostic procedures and pitfalls associated with ectopic ACTH-secreting tumors are demonstrated and discussed. A 41 year-old man presented with clinical features and biochemical tests suggestive of ectopic Cushing's syndrome. First, subtotal thyroidectomy was performed without remission of hypercortisolism, because an octreotide scan showed increased activity in the left thyroid gland and an ultrasound revealed nodules in both thyroid lobes one of which was autonomous. In addition, the patient had a 3 mm hypoenhancing lesion of the neurohypophysis and a 1 cm large adrenal tumor. Surgical removal of the pituitary lesion within the posterior lobe did not improve hypercortisolism and we continued to treat the patient with metyrapone to block cortisol production. At 18-months follow-up from initial presentation, we detected an ACTH-producing neuroendocrine carcinoma of the mesentery by using a combination of octreotide scan, computed tomography scan, and positron emission tomography. Intraoperatively, use of a gamma probe after administration of radiolabeled 111 In-pentetreotide helped identify the mesenteric neuroendocrine tumor. After removal of this carcinoma, the patient improved clinically. Laboratory testing confirmed remission of hypercortisolism. An octreotide scan 7 months after surgery showed normal results. This case underscores the diagnostic challenge in identifying an ectopic ACTH-producing tumor and the pluripotency of cells, in this case of mesenteric cells that can start producing and secreting ACTH. It thereby helps elucidate the pathogenesis of neuroendocrine tumors. This case also suggests that patients with ectopic Cushing's syndrome and an octreotide scan positive in atypical locations may benefit from

  20. An appraisal of the management of ectopic pregnancy in a nigerian tertiary hospital.

    Science.gov (United States)

    Igwegbe, Ao; Eleje, Gu; Okpala, Bc

    2013-04-01

    Ectopic pregnancy has remained a significant cause of maternal morbidity and mortality especially in the sub Saharan Africa. A periodic appraisal of its management is paramount. To determine the incidence and associated risk factors, for ectopic pregnancy, review available treatment modalities and suggest interventions to reduce its prevalence, morbidity and mortality. A cross sectional study with retrolective data collection of all cases of ectopic pregnancy managed in Nnamdi Azikiwe University Teaching Hospital, Nnewi, south-east Nigeria between 1(st) January, 2002 and 31(st) December, 2011 was undertaken. Analysis was carried out using Epi-info 2008 version 3.5.1. During the study period, there were a total 98 cases of ectopic pregnancies out of 8,811 deliveries and 1884 gynecological admissions, giving an incidence of 0.9% of all attendants or 1 in 90 deliveries and 5.2% of all gynecological admissions. Only 94.9% (93/98) case files were retrieved and were used in the final analysis. The mean age of the patients was 30.1 (0.7) years while the mean gestational age at presentations was 7.4 weeks. Previous induced abortion, 37.5% (36/93) was the commonest associated risk factor, followed by pelvic infections, 35.5% (33/93). The recurrence rate was 6.5% (6/93). Majority, 80.6% (75/93) presented with abdominal pain and 35.8% (33/93) presented with vaginal bleeding. Up to 88.2% (82/93) had salpingectomy while only 2.5% (2/93) were successfully managed medically with methotrexate therapy following diagnosis with transvaginal ultrasound Missed diagnosis of ectopic pregnancy occurred in 16.1% (15/93). There was no maternal death. Ectopic pregnancy has remained an important gynecological condition in our center. The common identifiable risk factors were induced abortion and pelvic infection. Early first trimester transvaginal ultrasound should be offered to all women for early diagnosis.